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Keeper of Mining Records, 
Formerly Professor of Physics, Government School of Mines, &c, &c, 





443 AND 445 BROADWAY. 

This Volume of Ure's 

Dictionary of Arts,. Manufactures, and 

Mines, contains the additional knowledge which has accumulated 

within the past ten years. 

Not a 

year has passed but that some 

important improvements in the Arts and Sciences have taken place, 

all of which form an important 

increase to knowledge, which 

cannot well be dispensed 

with by 

those who are engaged in the 

various pursuits in which 

they are 


The following are a few, amor 

g the many, who are specially 

Interested, viz. : 




Gas Light Companies, 


Glass Makers, 


Hat Makers, 

Boiler Makers, 

Iron Mongers, 

Brass Founders, 

India Rubber Manufacturers, 


Ink Manufacturers, 

Brick Makers, 

Leather Dealei's, 

Button Manufacturers, 




Coal Dealers, 



Calico Printers, 

Paper Manufacturers, 

Candle Makers, 






Cotton Factories, 


Carriage Makers, 

Pope Makers, 


Shipping Merchants, 


Sugar Refiners, 




Soap Makers, 







Gold Beaters, 

Wine Growers, 





Ure's Dictionary of Arts, Manufactures, and Mines has long had the 
reputation of a standard authority upon the subjects of which it treats. 
But such is the inventive activity of the age, and the rapid improvement 
in art processes, that a work of this kind can only maintain its character 
by frequent and extensive additions. While the distinguished author 
was in the vigor of his intellect, the revisions of the work kept pace with 
the progress of improvement, but at his demise it was found necessary to 
organize a plan for bringing up the Dictionary to the present state of 
knowledge. Accordingly, Mr. Robert Hunt, a gentleman whose high 
scientific position gave warrant that the work would be well performed, 
assumed the editorship, and a corps of the ablest practical and scientific 
men in England was secured to prepare articles in their several depart- 
ments. The following remarks, condensed from the preface to the Eng- 
lish edition, will explain the purpose and plan of the editor. 

" The objects which have been steadily kept in view are the follow- 
ing : To furnish a work of reference on all points connected with the sub- 
jects included in its design, which should be of the most reliable character. 
To give to the scientific student and the public the most exact details 
of those manufactures which involve the application of the discoveries 
of either physics or chemistry. To include so much of science as may 
render the philosophy of manufactures at once intelligible, and enable 
the technical man to appreciate the value of abstruse research. 

" I commenced the new edition of Ure's Dictionary with an earnest 
determination to render the work as complete and as correct as it was 
possible for me to make it. In my necessities I have asked the aid of 
the manufacturer, and the advice of the man of science, and never having 
been refused the aid solicited, I am led to hope that those who may pos- 
sess these volumes will find in them more practical knowledge than ex- 
ists in any work of a similar character." 

This volume of Ure's Dictionary contains the chief additions made 
to the late English edition. Those portions of the work which concerned 
mainly the English, their commercial and manufacturing resources and 
statistics, the least important historic notices, and some definitions in 
pure science, which seemed hardly embraced within the defined scope of 
the work, have been omitted. By this means the original and valuable 
contributions to the work have been brought within the limits of a single 


volume, which has lost nothing of its real value. This supplementary 
volume is rich with the latest results of inquiry, containing all the new 
and important matter and illustrations of the three English volumes 
costing $38, while the complete American edition of the work, in three 
volumes, comprising 3212 pages, with 2300 engravings, forms the com- 
pletest repertory of arts, manufactures, and mines, which has been yet 

Subjoined is a list of the contributors, whose initials will be found 
appended to their respective articles. Mr. Hunt avows the authorship 
of the rest. 

G. ANSELL, Esq., Royal Mint. 

H. K. BAMBER, Esq., F.C.S.,, &c. 

JE. W. BINNEY, Esq., F.G.S., &c, Manchester. 

H. W. BONE, Esq. Euameller. 

'HENRY W. BRISTOW, Esq., F.G.S. Geo- 
logical Survey of Great Britain. 

R. J. COURTNEY, Esq. Superintendent of 
Messrs. Spottiswoode and Co.'s Printing office. 

JAMES DAFFORNE, Esq. Assistant Editor 
of the Art Journal. 

JOHN DARLINGTON, Esq.- Mining Engi- 
neer. Author of Miner's Handbook. 

F. W. FAIRHOLT, Esq., F.R.A.S. Author 
of Costume in England, Dictionary of Terms 
in Art, &c. 

E. FRANKLAND, Esq., Ph.D., F.R.S., and 
C.S. Professor of Chemistry at St. Bartholo- 
mew's Hospital, and Lecturer on Chemistry at 
the Eoyal Indian Military College, Addiscombe. 

ALFRED FRYER, Esq. Sugar Refiner, Man- 

{The late) T. H. HENRY, Esq., F.R.S. and 


R. HERRING, Esq. Author of History of 

Paper Manufacture. 
JAMES HIGGINS, Esq. Calico Printer, &c, 

W. HERAPATH, Esq., M.D., &c. 
SAMUEL HOCKING, Esq., C.E., Seville. 
RICHARD W. HUNT, Esq. Brewer, Leeds. 
T. B. JORDAN, Esq. Engineer, Inventor of 

Wood Carving Machinery. 
WILLIAM LINTON, Esq. Artist, Author of 

Ancient and Modern Colors. 

JAMES McADAM, Jun., Esq. Secretary of 
the Eoyal Society for the Cultivation of Flax 
in Ireland. 

{The late) HERBERT MACKWORTH, Esq., 
C.E., F.O.S. One of H. M Inspectors of Coal 

HENRY MARLES, Esq., L.R.C.P. Author 
of English Grammar, Currying and Leather. 

DAVID MORRIS, Esq., of Manchester. Au- 
thor of Cottonopolis, &c. 

JAMES NAPIER, Esq., .F.C.S. Author of 
Manual of Dyeing, Electro-Metallurgy, An- 
cient Works in Metal, &c. 

D. NAPIER, Esq., C.E., &c. 

A. NORMANDY, Esq., M.D., F.C.S. Author 
of Handbook of Commercial Chemistry. 

HENRY M. NOAD, Esq., Ph.D., F.R.S. Au- 
thor of A Manual of Electricity, &.C. 

sistant Chemist, University of Oxford. 

ROBERT OXLAND, Esq., F.C.S. One of the 

Authors of Metals and their Alloys. 


Secretary to London Mechanics' Institution. 
SEPTIMUS PIESSE, Esq. Author of Treatise 

on Art of Perfumery, &c. 

of the Imperial School of Mines, Paris, Author 

of Manual of Metallurgy. 

and G.S., Professor of Geology, Government 
School of Mines, Local Director of the Geologi- 
cal Survey of Great Britain. 

President of the South Wales Institute of En- 

CHARLES SANDERSON, Esq., Sheffield. 
Author of Papers on Stetl and Iron. 

E. SCHUNCK, Esq., Ph.D., F.R.S., and C.S. 

R. ANGUS SMITH, Esq., Ph.D., F.R.S. Au- 
thor of various Papers on Air and Water, Life 
of Dalton, and llistory of Atomic Theory, &c. 

and G. S. Professor of Mining and Mineraloey, 
Government School of Mines, and Inspector 
of Crown Mines. 

THOMAS SOPWITH, Esq., C.E., F.R.S., and 
G.S. Author of Lsometrical Drawing, &c. 

F.E.S. Professor of Chemistry in St. Thomas's 
Hospital College. 

ALFRED TYLOR, Esq., F.G.S. Author of 
Treatise on Metal Work. 

A. VOELCKER, Esq., Ph.D., F.C.S. Profes- 
sor of Chemistry, Agricultural College, Ciren- 
cester, and Consulting Chemist to the Eoyal 
Agricultural Society of England. 

F.E.A.S. Engineer of Telegraphs and Time to 
the South Eastern Eaihvay Company, Author 
of Electrotype Manipulation, Translator of 
Kcemts' Meteorology, Dela Rive's Electricity, 

■ &c. 

A Handbook of Chemical Manipulation, &c. 

{The late) HENRY M. WITT, Esq., F.C.S. 
Assistant Chemist, Government School of 

With special assistance and information from 
the late Sir Wm. Reid, C.B., Governor of 
Malta ; Sir Wm. Armstrong, C.E., &c. ; 
Robert Mallet, Esq., C.E., F R.S., &c. ; 
Captain Drayson, Royal Artillery ; George 
W. Lenox, Esq. ; and many others- 



ABA. A woollen stuff manufactured in Turkey. 

ABACA. A species of fibre obtained in the Philippine Islands in abundance. Some 
authorities refer those fibres to the palm-tree known as the Abaca, or Anisa textilis. There 
seem, indeed, several well-known varieties of fibre under this name, some so fine that they 
are used in the most delicate and costly textures, mixed with fibres of the pine-apple, form- 
ing Pina muslins and textures equal to the best muslins of Bengal. Of the coarser fibres, 
mats, cordage, and sail-cloth are made. M. Duchesne states, that the well-known fibrous 
manufactures of Manilla have led to the manufacture of the fibres themselves, at Paris, into 
many articles of furniture and dress. Their brilliancy and strength give remarkable fitness 
for bonnets, tapestry, carpets, network, hammocks, &c. The only manufactured articles 
exported from the Philippine Islands, enumerated by Thomas de Comyn, Madrid, 1820 
(transl. by Walton), besides a few tanned buffalo hides and skins, are 8,000 to 12,000 pieces 
of light sail-cloth, and 200,000 lbs. of assorted abaca cordage. 

ABIES (in Botany), the fir, a genus of trees which belong to the coniferous tribe. These 
trees are well known from their ornamental character, and for the valuable timber which they 
produce. They yield several resins or gum resins, which are useful in the arts. 

ABIES BALSAMEA (the Balm of Gilead fir) produces the Canadian balsam. This tree 
grows most abundantly in the colder regions of North America. 

ABIES CANADENSIS (the hemlock spruce fir). A considerable quantity of the es- 
sence of spruce is extracted from the shoots of this tree ; it is, however, also obtained from 
other varieties of the spruce fir. 

ABIES PICE A of Linnaeus (Abies pectinata of De Candole). The Silver fir, producing 
the Burgundy pitch and the Strasburg turpentine. 

ABLETTE, or ABLE, is a name given to several species of fish, but particularly to the 
Bleak, the scales of which are employed for making the pearl essence which is used in the 
manufacture of artificial pearls. See Pearls, Artificial. 

ABRASION. The figuration of materials by wearing down the surface. See ' File, 
vol. i. 

ACACIA. (L. acacia, a thorn; Gr. aid), a point.) The acacia is a very extensive 
genus of trees or shrubby plants, inhabiting the tropical regions generally, but extending in 
some few instances into the temperate zone ; being found, for example, in Australia, and 
the neighboring islands. Botanists are acquainted with nearly 300 species of the acacia ; 
some of these yield the gum arabic and the gum catechu of commerce ; while the bark of 
others yields a large quantity of tannin, especially a variety which grows in Van Diemen's 
Land, or Tasmania. See Arabic, Gum ; Catechu. 

ACACIA ARABICA. An inhabitant of Arabia, the East Indies, and Abyssinia. One 
of the plants yielding the gum arabic, which is procured by wounding the bark of the tree, 
after which the sap flows out and hardens in transparent lumps. 

ACACIA CATECHU. The catechu acacia (Mimosa catechu of Linnaeus) is a tree with a 
moderately high and stout stem, growing in mountainous places in Bengal and Coromandel, 
and in other parts of Asia. Its unripe pods and wood, by decoction, yield the catechu or 
terra Japonica of the shops. 

ACESCENT. Substances which have a tendency to pass into an acid state ; as an infu- 
sion of malt, &c. 


ACETAL. (C 12 H" O 4 .) One of the products of the oxidation of alcohol under tho in- 
fluence of the oxygen condensed in platina black. It is a colorless, mobile, ethereal liquid 
boiling at 221° F. Its density in the fluid state is 0-821 at 72°. The specific gravity of its 
vapor 4 - 13S Stas. (mean of three experiments) : calculation gives 4-083 for four volumes 
of vapor. — For the description of the modes of determining vapor volume, consult some 
standard chemical work. — The recent researches of Wurtz render it evident that the con- 
stitution of acetal is quite different to what has generally been supposed, and that it is in 
fact glycodiethyline ; that is to say, glycole in which two equivalents of hydrogen are re- 
placed by two equivalents of ethyle. — C. G. W. 

ACETATE. (Ackate, Ft. ; Essigsaure, Germ.) Any salient compound in which the 
acid constituent is acetic acid. All acetates are soluble in water : the least soluble being 
the acetates of tungsten, molybdenum, silver, and mercury. The acetates, especially those 
of lead and alumina, are of great importance to the arts. The acetates are all described un- 
der their respective bases ; — a rule which will be adopted with all the acids. 

ACETIC ACID. (Acide acetigue, Ft. ; Essigsaure, Germ. ; Acidum aceticurn, Lat. ; 
Msel, Sax.) The word "acetic" is derived from the Latin acetum, applied to vinegar; 
probably the earliest known body possessing the sour taste and other properties which 
characterize acids ; hence the term Acid, "now become generic ; both the Latin word, and 
also the Saxon acid being from the root acics (Greek d/cJ;), an edge or point, in reference to 
the sharpness of the taste. 

Acetic acid is produced either by the oxidation, or the destructive distillation, of organic 
bodies containing its elements — carbon, hydrogen, and oxygen. 

The oxidation of organic bodies, in order to convert them into acetic acid, may be 
effected either : — 1, by exposing them in a finely divided state to the action of air or oxygen 
gas ; 2, by submitting them to the action of ferments, in the presence of a free supply of 
atmospheric air ; or, 3, by the action of chemical oxidizing agents. 

When acetic acid is procured by the oxidation of organic bodies, it is generally alcohol 
that is employed ; but by whatever process alcohol is transformed into acetic acid, it is 
always first converted into an intermediate compound, aldehyde ; and this being a very vola- 
tile body, it is desirable always to effect the oxidation as completely and rapidly as possible, 
to avoid the loss of alcohol by the evaporation of this aldehyde. 

Alcohol contains C 4 H 6 O 2 
Aldehyde " C 4 H 4 2 
Acetic acid " C 4 H 4 O 4 

The process, therefore, consists first in the removal of two equivalents of hydrogen from 
alcohol, which are converted into water, — aldehyde being produced, — and then the further 
union of this aldehyde with two equivalents of oxygen to convert it into acetic acid. See 

By the oxidation of alcohol, pure acetic acid is obtained : but the vinegars of commerce 
are mixtures of the pure acetic acid with water ; with saccharine, gummy, and coloring mat- 
ters ; with certain ethers (especially the acetic ether), upon which their agreeable aromatic 
flavor depends ; with empyf eumatic oils, &c. 

The pure acetic acid (free from water and other impurities) may be obtained most ad- 
vantageously, according to Melsens*, by distilling pure acetate of potash with an excess of 
acetic acid (which has been obtained by the redistillation of ordinary acetic acid, procured 
either by oxidizing alcohol, or by the destructive distillation of wood) : the acid which first 
passes over contains water ; but finally it is obtained free. 

Properties of pure Acetic Acid. — When absolutely pure, acetic acid is a colorless liquid 
of specific gravity 1-064, which at temperatures below 62° F. (11° C.) solidifies into a color- 
less crystalline mass. It has strongly acid properties, being as powerfully corrosive as many 
mineral acids, causing vesication when applied to the skin ; and it possesses a peculiarly 
pungent, though not a disagreeable smell. 

The vapor of the boiling acid is highly combustible, and burns with a blue flame. Hy- 
drated acetic acid dissolves camphor, gliadine, resins, the fibrine of blood, and several or- 
ganic compounds. When its vapor is conducted through a slightly ignited porcelain tube, 
it is converted entirely into carbonic acid and acetone, an atom of the acid being resolved 
into an atom of each of the resultants. At a white heat the acid vapor is converted into 
carbonic acid, carburetted hydrogen, and water. 

It attracts water with great avidity, mixing with it in all proportions. Its solution in 
water increases in density with the increase of acetic acid up to a certain point ; but beyond 
this point its density again diminishes. Its maximum density being 1-073, and correspond- 
ing to an acid containing C 4 H 4 O 4 -4- 2Aq., which may be extemporaneously produced by 
mixing 7V-2 parts of crytallized acetic acid with 22 - 8 parts of water. This hydrate boils at 
104° C. (219° F.), whilst the crystallized acid boils only at 120° C. (248° F.)f 

* Comptes rendns, six. 611. t Gerhardt, Chimie Organique, i. 71S. 


The proportion of acetic acid in aqueous mixtures may therefore be ascertained, within 
certain limits, by determination of the specific gravity. See Acetimetry. 

The following table, by Mohr, indicates the percentage of acetic acid in mixtures- of 
different specific gravities ; but of course this is only applicable in cases where no sugar or 
other bodies are present, which increase the specific gravity. 

Abstract of Mohr s Table of the Specific Gravity of Mixtures of Acetic 

Acid and Water.* 

Percentage of Acetic 
Acid, t* H-i OK 


Percentase of Acetic 
Acid, C* H< O*. 












































Which numbers closely agree with those obtained by Dr. Ure. See vol. i. p. 5. 

Acetic acid was formerly (and is still by some chemists) viewed as the hydrated teroxide 
of a radical acetyl, now called vinyl. See Chemical Formula. 

(C 4 H 3 ) O 3 , HO 


And therefore an anhydrous acetic acid, C H 3 3 , is supposed to exist. Many attempts 
have been made to isolate this anhydrous acetic acid C 4 H 3 O 3 ; and a body which has re- 
ceived this name has been quite recently obtained by Gerhardtf, by the double decomposi- 
tion of chloride of acetyl and an alkaline acetate, thus : — 

C 4 H 3 (O 2 CI) -f- KO,C 4 H 3 O 3 = C 8 H G 6 + K CI 

Chloride of Acetate of (So-called) Chloride of 

acetyl. potash. Anhydrous potassium. 

acetic acid. 

This body Gerhardt describes as a colorless liquid having a strong smell of acetic acid, 
but associated with the flavor of hawthorne blossom, having a specific gravity of 1-073, and 
boiling at 137° C. (278° F.) ; falling in water in the form of oily drops, only dissolving on 
gently heating that fluid. It is, however, not anhydrous acetic acid, but a compound iso- 
meric with the hypothetical anhydrous acetic acid C 4 H 3 O 3 , containing, in fact, double the 
amount of matter, its formula being C 8 H 6 O 6 . 

The impure varieties of acetic acid known as vinegar, pyroligneous acid, &c, are the 
products met with in commerce, and therefore those require more minute description in this 

Before describing the manufacture of these commercial articles, it may be interesting to 
allude to a method of oxidizing alcohol by means of spongy platinum ; which may yet meet 
with extensive practical application. It is a well-known fact that spongy platinum (e. g. 
platinum black), from its minute state of division, condenses the oxygen of the air within 
its pores ; consequently, when the vapor of alcohol comes in contact with this body, a supply 
of oxygen in a concentrated state is presented to it, and the platinum, without losing any 
of its properties, eifects the combination between the oxygen and the alcohol, converting the 
latter into acetic acid. 

This may be illustrated by a very simple experiment. Place recently ignited spongy 
platinum, loosely distributed on a platinum-gauze, at a short distance over a saucer contain- 
ing warm alcohol, the whole standing under a bell-glass supported by wedges on a glass 
dish, so that, on removing the stopper from the bell-glass, a slow current of air circulates 
through the apparatus ; the spongy platinum soon begins to glow, in consequence of the 
combustion going on upon its surface, and acetic acid vapors are abundantly produced, which 

* Mohr, Ann. der Chem. und Phar. xxxi. 227. 

t Comptes rendus, xxxiv. 755. 


condense and run down the sides of the glass. The simultaneous formation of aldehyde is 
at the same time, abundantly proved by its peculiar odor. 

In Germany this method has been actually carried out on the large scale, and, if it -were 
not for the high price of platinum, and the heavy duty on alcohol, it might be extensively 
employed in this country, on account of its elegance and extreme simplicity. 

Manufacture of Vinegar by Acetous Fermentation. — All liquids which are susceptible 
of the vinous fermentation are capable of yielding vinegar. A solution of suo-ar is the 
essential ingredient, which is converted first into alcohol, and subsequently into acetic 
acid. The liquids employed vary according to circumstances. In this country the vine- 
gar of commerce is obtained from an infusion of malt, and in wine countries from inferior 

The oxidation of alcohol is remarkably facilitated by the presence of nitrogenized 
organic bodies in a state of change, called ferments, hence the process is frequently termed 
acetous fermentation. Now, although in most cases the presence of these ferments curi- 
ously promotes the process, yet they have no specific action of this kind ; for we have 
already seen that, by exposure to air in a condensed state, alocohol, even when pure, is 
converted into acetic acid; and, moreover, the action of oxidizing agents, such as chromic 
and nitric acid, &c, is capable of effecting this change. 

However, in the presence of a ferment, with a free supply of air, and at a temperature 
of from 60° to 90° F., alcohol is abundantly converted into acetic acid. 

At the same time that the alcohol is converted # into acetic acid, the nitrogenized and 
other organic matters undergo peculiar changes, and often a white gelatinous mass is de- 
posited, — which contains Vibriones and other of the lower forms of organized beings, — and 
which has received the name of mother of vinegar,* from the supposition that the for- 
mation and development of this body, instead of being a secondary result of the process, 
was really its exciting cause. 

Wine vinegar is of two kinds, white and red, according as it is prepared from white or 
red wine. White wine vinegar is usually preferred, and that made at Orleans is regarded 
as the best. Dr. Ure found its average specific gravity to be 1-019, and to contain from 64- 
to 7 per cent, of real acid ; according to the Edinburgh Pharmacopoeia, its specific gravity 
varies from 1-014 to 1-022. 

1. Malt Vinegar. (British Vinegar; in Germany called Malz-Gctreide or Bier- 
essig.) In England vinegar is chiefly made from an infusion of malt, by first exciting in it 
the alcoholic fermentation, and subsequently inducing the oxidation of the alcohol into 
acetic acid. 

The transformation of the fermented wort into vinegar was formerly effected in two 
ways, which were entirely opposite in their manner of operation. In one case the casks 
containing the fermented malt infusion (or gyle) were placed in close rooms, maintained at 
a uniform temperature ; in the other, they were arranged in rows in an open field, where 
they remained many months. As regards the convenience and interests of the manufac- 
turer, it appears that each method had its respective advantages, but both are now almost 
entirely abandoned for the more modern processes to be described — a short notice of 
the fielding process is, however, retained. 

When fielding is resorted to, it must be commenced in the spring months, and then left 
to complete itself during the warm season. The fielding method requires a much larger 
extent of space and utensils than the stoving process. The casks are placed in several 
parallel tiers, with their bung side upwards and left open. Beneath some of the paths 
which separate the rows of casks are pipes communicating with the " back " at the top of 
the brewhouse ; and in the centre of each is a valve, opening into a concealed pipe. When 
the casks are about to be filled, a flexible hose is screwed on to this opening, the other end 
being inserted into the bung-hole of the cask, and the liquor in the "gyle back" at the 
brewhouse, by its hydrostatic pressure, flows through the underlying pipe and hose into the 
cask. The hose is so long as to admit of reaching all the casks in the same row, and is 
guided by a workman. 

After some months the vinegar is made, and is drawn off by the following operation : — 
A long trough or sluice is laid by the side of one of the rows of casks, into which the 
vinegar is transferred by means of a syphon, whose shorter limb is inserted into the bung- 
hole of the cask. The trough inclines a little from one end to the other, and its lower end 
rests on a kind of travelling tank or cistern, wherein the vinegar from several casks is col- 
lected. A hose descends from the tank to the open valve of an underground pipe, which 
terminates in one of the buildings or stores, and, by the agency of a steam boiler and 
machinery, the pipe is exhausted of its air, and this causes the vinegar to flow through the 
hose into the valve of the pipe, and thence into the factory buildings. By this arrange- 
ment the whole of the vinegar is speedily drawn off. From the storehouse, where the 
vinegar is received, it is pumped into the refining or rape vessels. 

* This substance has been supposed by some to be a fungus, and has been described by Mulder under 
the name of Mycooederni Aceti. 


These rape vessels are generally filled with the stalks and skins of grapes or raisins, 
(the refuse of the British wine manufacturer is generally used,) and the liquor being 
admitted at the top, is allowed slowly to filter through them ; after passing through, it is 
pumped up again to the top, and this process is repeated until the acetification is complete. 
Sometimes wood shavings, straw, or spent tan, are substituted for the grape refuse, but the 
latter is generally preferred. 

By this process, not only is the oxidation of the alcohol completed, but coagulable nitro- 
genous and mucilaginous matter is separated, and thus the vinegar rendered bright. It is 
finally pumped into store vats, where it is kept until put into casks for sale. 

2. Sugar, Cider, Fruit, and Beet Vinegars. An excellent vinegar may be made for 
domestic purposes by adding, to a syrup consisting of one pound and a quarter of sugar 
for every gallon of water, a quarter of a pint of good yeast. The liquor being maintained 
at a heat of from 75° to 80° F., acetification will proceed so well that in 2 or 3 days it may 
be racked off from the sediment into the ripening cask, where it is to be mixed with 1 oz. 
of cream of tartar and 1 oz. of crushed raisins. When completely freed from the sweet 
taste, it should be drawn off clear into bottles, and closely corked up. The juices of cur- 
rants, gooseberries, and many other indigenous fruits, may be acetified either alone or in 
combination with syrup. • Vinegar made by the above process from sugar should have fully 
the Revenue strength. It will keep much better than malt vinegar, on account of the 
absence of gluten, and at the present low price of sugar will not cost more, when fined 
upon beech chips, than Is. per gallon. 

The sugar solution may likewise be replaced by honey, cider, or any other alcoholic or 
saccharine liquid. An endless number of prescriptions exist, of which the following example 
may suffice : — 100 parts of water to 18 of brandy, 4 of honey, and 1 of tartar. 

Messrs. Neale and Duyck, of London, patented a process, in 1841, for the manufacture 
of vinegar from beet-root. 

The saccharine juice is pressed out of the beet, previously rasped to a pulp, then mixed 
with water and boiled ; this solution is fermented with yeast, and finally acetified in the 
usual way, the process being accelerated by blowing air up through the liquid, which is 
placed in a cylindrical vessel with fine holes at the bottom. 

In some factories large quantities of sour ale and beer are converted into vinegar ; but 
it is usually of an inferior quality, in consequence of being liable to further fermentation. 

Dr. Stenhouse has shown that when sea-weed is subjected to fermentation at a tempera- 
ture of 96° F., in the presence of lime, acetate of lime is formed, from which acetic acid 
may be liberated by the processes described under the head of Pyroligneous Acid. Although 
such large quantities of sea-weed are found on all our coasts, it does not yet appear that 
they have yet been utilized in this way, although they would still be, to a certain extent, 
valuable as manure after having been subjected to this process. 

3. The German or Quick- Vinegar Process. (Schnellessigbereitung.) — In the manu- 
facture of vinegar it is highly important that as free a supply of air should be admitted to 
the liquid as possible, since, if the oxidation take place but slowly, a considerable loss may 
be sustained, from much of the alcohol, instead of being completely oxidized to acetic acid, 
being only converted into aldehyde, which, on account of its volatility, passes off in the 
state of vapor. This is secured in the German process by greatly enlarging the surface 
exposed to the air ; which, however, not only diminishes or prevents the formation of alde- 
hyde, but also greatly curtails the time necessary for the whole process. In fact, when this 
method was first introduced, from the supply of air being insufficient, very great loss was 
sustained from this cause, which was, however, easily remedied by increasing the number 
of air-holes in the apparatus. 

This quick-vinegar process consists in passing the fermented liquor (which generally 
contains about 50 gallons of brandy of 60 per cent., and 37 gallons of beer or maltwort, 
with j-gftj; of ferment) two or three times through an apparatus called the Vinegar Genera- 
tor (essigbilder). See Graduator, vol. i. 

The analogy between acetification and ordinary processes of decay, and even combustion, 
is well seen in this process -, for, as the oxidation proceeds, the temperature of the liquid 
rises to 100° or even 104° F. ; but if the temperature generated by the process itself be 
not sufficient, the temperature of the room in which the tuns are placed should be artifi- 
cially raised. 

By this method 150 gallons of vinegar can be manufactured daily in ten tuns, which one 
man can superintend ; and the vinegar, in purity and clearness, resembles distilled vinegar. 

It is better to avoid using liquors containing much suspended mucilaginous matter, 
which, collecting on the chips, quickly chokes up the apparatus, and not only impedes the 
process, but contaminates the product. 

The chips and shavings may with advantage be replaced by charcoal in fragments, which, 
by the oxygen it contains condensed in its pores, still further accelerates the process. The 
charcoal would, of course, require re-igniting from time to time. 

By destructive Distillation of Wood. Pyroligneous Acid. — The general nature of the 



process of destructive distillation will be found detailed under the head of Distillation, 
Destructive ; as well as a list of products of the rearrangement of the molecules of organic 
bodies under the influence of heat in closed vessels. We shall, therefore, at once proceed 
to the details of the process as specially applied in the manufacture of acetic acid from wood. 
The forms of apparatus very generally employed on the continent for obtaining at the 
same time crude acetic acid, charcoal, and tar, are those of Schwartz and Reichenbach ; but in 
France the process is carried out with special reference to the production of acetic acid alone. 
Since the carbonizers of Reichenbach and Schwartz are employed with special reference 
to the manufacture of wood charcoal, the condensation of the volatile products being only 
a secondary consideration, they will be more appropriately described under the head of 

In England the distillation is generally carried out in large iron retorts, placed horizon- 
tally in the furnace, the process, in fact, closely resembling the distillation of coal in the 

manufacture of coal gas, 
1 excepting that the retorts 

are generally larger, be- 
ing sometimes -4 feet in 
.diameter, and 6 or 8 feet 
long. Generally two, or 
even three, are placed in 
each furnace, as shown in 
fig. 1, so that the fire of 
the single furnace, a, 
plays all round them. 
The doors for charging 
the retorts are at one end, 
b, (fig. 2), and the pipe 
for carrying off the vola- 
tile products at the other, 
e, by which they are con- 
ducted, first to the tar- 
condenser, rf, and finally 
through a worm in a large 
tub, e, where the crude 
acetic acid is collected. 

Of course, in different 
localities an endless va- 
riety of modifications of 
the process are employed. 
In the Forest of Dean, 
instead of cylindrical re- 
torts, square sheet-iron 
boxes are used, 4 ft. 6 in. 
by 2 ft. 9 in., which are 
heated in large square 

With regard to the 
relative advantages of 
cylindrical retorts or 
square boxes,, it should 
be remarked that the 
cylinders are more 
adapted for the distilla- 
tion of the large billets 
of Gloucestershire, and 
the refuse ship timber of 
Glasgow, Newcastle, and 
Liverpool ; but, on the 
other hand, where light 
wood is used, such as that generally carbonized in the Welsh factories, the square ovens 
answer better. 

The most recent and ingenious improvement in the manufacture of pyroligneous acid is 
that patented by the late Mr. A. G. Halliday, of Manchester, and adopted by several large 
manufacturers. The process consists in effecting the destructive distillation of waste mate- 
rials, such as saw-dust and spent dye-woods, by causing them to pass in continuous motion 
through heated retorts. For this purpose the materials, which are almost in a state of 
powder, are introduced into a hopper, h (fig. 3), whence they descend into the retort, b, 



being kept all the while in constant agitation, and at the same time moved forward to the 
other end of the retort by means of an endless screw, s. By the time they arrive there, the 
charge has been completely carbonized, and all the pyroligneous acid evolved at the exit 
tube, t. The residuary charcoal falls through the pipe d into a vessel of water, e, whilst the 
volatile products escape at f, and are condensed in the usual way. 

Several of these retorts are generally set in a furnace side by side, the retorts are only 
14 inches in diameter, and eight of these retorts produce in 24 hours as much acid as 16 
retorts 3 feet in diameter upon the old system. In the manufacturing districts of Lancashire 
and Yorkshire, where such immense quantities of spent dye-woods accumulate, and have 
proved a source of annoyance and expense for their removal, this process has afforded a 
most important means of economically converting them into valuable products — charcoal 
and acetic acid. 

Mention should also be made of Messrs. Solomons and Azulay's patent for employing 
superheated steam to effect the carbonization of the wood, which is passed directly into the 
mass of materials. Since the steam accompanies the volatile products, it necessarily dilutes 
the acid ; but this is in a great degree compensated for by employing these vapors to con- 
centrate the distilled products, by causing them to traverse a coil of tubing placed in a pan 
of the distillates. 

As regards the yield of acetic acid from the different kinds of wood, some valuable facts 
have been collected and tabulated by Stolze, in his work on Pyroligneous Acid : — 

One Pound of Wood. 

Weight of 

Carbonate of 
Potassa neu- 
tralized by 
One Ounce of 

Weight of 

White birch • - Betula alba ... 

Red birch - - Fagus sylvatica 

Large-leaved linden Tilia pataphylla 

Oak ... Quercus robur - 

Ash ... Fraxinus excelsior 

Horse chestnut - Esculus hippocastanus 

Lombardy poplar - Populus dilatata 

White poplar - Populus alba - 

Bird cherry - - Prunus padus - 

Basket willow - Salix - 

Buckthorn - - Rhamnus - - - - 

Logwood - - Hematoxylon campechianum 

Alder - - - Alnus .... 

Juniper - - - Juniperus communis - 

White fir - - Pjnus abies 

Common pine - Pinus sylvestris 

Common savine - Juniperus sabina 

Red fir - - - Abies pectinata 










il • 








H ■ 











Properties of the crude Pyroligneous Acid. — The crude pyroligneous acid possesses the 
properties of acetic acid, combined -with those of the pyrogenous bodies with which it is 
associated. As first obtained, it is black from the large quantity of tar which it holds in 
solution ; and although certain resins are removed by redistillation, yet it is impossible to 
remove some of the empyreumatic oils by this process, and a special purification is necessary. 

In consequence of the presence of creosote, and other antiseptic hydrocarbons, in the 
crude pyroligneous acid, it possesses, in a very eminent degree, anti-putrescent properties. 
Flesh steeped in it for a few hours may be afterwards dried in the air without corrupting ; 
but it becomes hard, and somewhat leather-like : so that this mode of preservation does not 
answer well for butcher's meat. Fish are sometimes cured with it. 

Purification of Pyroligneous Acid. — This is effected either, 1st, by converting it into 
an acetate, — acetate of lime or soda, — and then, after the purification of these salts by 
exposure to heat sufficient to destroy the tar, and repeated recrystallization, liberating the 
acid again by distilling with a stronger acid, e. g. sulphuric. 

Or, 2d, by destroying the pyrogenous impurities by oxidizing agents, such as binoxide 
of manganese in the presence of sulphuric acid, &c. 

The former is the method generally adopted. 

After the naphtha has been expelled, the acid liquor is run off into tanks to deposit part 
of its impurities ; it is then syphoned off into another vessel, in which is either milk of lime, 
quicklime, or chalk ; the mixture is boiled for a short time, and then allowed to stand for 
24 hours to deposit the excess of lime with any impurities which the latter will carry down 
with it. The supernatant liquor is then pumped into the evaporating pans. 

The evaporation is effected either by the heat of a fire applied beneath the evaporating 
pans, or more frequently by a coil of pipe in the liquor, through which steam is passed — 
the liquor being kept constantly stirred, and the impurities which rise to the surface during 
the process carefully skimmed off. 

From time to time, as the evaporation advances, the acetate of lime which separates is 
removed by ladles, and placed in baskets to drain ; and the residual mother liquor is 
evaporated to dryness. This mass, by ignition, is converted into carbonate of lime and 

If the acetate of lime has been procured by directly saturating the crude acid, it is called 
brown acetate ; if from the acid once purified by redistillation, it is called gray acetate. 

From this gray acetate of lime, acetate of soda is now prepared, by adding sulphate of 
soda to the filtered solution of the acetate of lime. In performing this operation, it is highly 
important to remember that, for every equivalent of acetate of lime, it is necessary to add 
two equivalents of sulphate of soda, on account of the formation of a double sulphate of soda 
and lime. The equation representing the change being : — 

CaO, C 4 H 3 O 3 + 2(NaO, SO 3 ) = NaO,0 4 H 3 O 3 -f- CaO, SO 3 . NaO, SO 3 

Acetate of lime. Acetate of soda. Double sail. 

Or, if sulphuric acid be considered as a bibasie acid, which this very reaction so strongly 
justifies — 

C 4 H 3 (Ca) 4 + Na a S= O 8 = C 4 H 3 (Na) O 4 + jM S= 8 

Acetate of lime. Sulphate of soda. Acetate of soda. Double salt. 

If this point be neglected, and only one equivalent of sulphate of soda be used, one-half of 
the acetate of lime may escape decomposition, and thus be lost. 

After the separation of the double salt, the solution of acetate of soda is drawn off, any 
impurities allowed to subside, and then concentrated by evaporation until it has a density 
of 4-3 — when the acetate of soda crystallizes out, and may be further purified, if requisite, 
by another re-solution and re-crystallization. The contents of the mother liquors are con- 
verted into acetone and carbonate of soda, as before. 

The crystallized acetate of soda is now fused in an iron pot, at a temperature of about 
400°, to drive off the water of crystallization, the mass being kept constantly stirred. A 
stronger heat must not be applied, or we should effect the decomposition of the salt. 

For the production of the acetic acid from this salt, a quantity of it is put into a stout 
copper still, and a deep cavity made in the centre of the mass, into which sulphuric acid of 
specific gravity 1-84 is poured in the proportion of 35 per cent, of the weight of the salt; 
the walls of the cavity are thrown in upon the acid, the whole briskly agitated with a wooden 
spatula. The head of the still is then luted, and connected with the condensing worm, and 
the distillation carried on at a very gentle heat. The worm should be of silver or porcelain, 
as also the still head ; and even silver solder should be used to connect the joinings in the 
body of the still. The still is now generally heated by a steam "jacket." See Distillation. 

The acid which passes over is nearly colorless, and has a specific gravity of l - 05. That 



which collects at the latter part of the operation is liable to be somewhat empyreumatic, and 
therefore, before this point is reached, the receiver should be changed ; and throughout the 
entire operation, care should be taken to avoid applying too high a temperature, as the 
flavor and purity of the acid will invariably suffer. 

Any trace of empyreuma may be removed from the acid by digestion with animal char- 
coal and redistillation. 

A considerable portion of this acid crystallizes at a temperature of from 40° to 50° F, 
constituting what is called glacial acetic acid, which is the oompound C H 4 O l (or C 4 H 3 
O 3 , HO). 

For culinary purposes, pickling, &c, the acid of specific gravity 1-05 is diluted with five 
times its weight in water, which renders it of the same strength as Revenue proof vinegar. 

Several modifications and improvements of this process have recently been introduced, 
which require to be noticed. 

The following process depends upon the difficult solubility of sulphate of soda in strong 
acetic acids : — 100 lbs. of the pulverized salt being put into a hard glazed stoneware re- 
ceiver, or deep pan,' from 35 to 36 lbs. of concentrated sulphuric acid are poured in one 
stream upon the powder, so as to flow under it. The mixture of the salt and acid is to be 
made very slowly, in order to moderate the action and the heat generated, as much as 
possible. After the materials have been in intimate contact for a few hours, the decompo- 
sition is effected ; sulphate of soda in crystalline grains will occupy the bottom of the vessel 
and acetic acid the upper portion, partly liquid and partly in crystals. A small portion of 
pure acetate of lime added to the acid will free it from any remainder of sulphate of soda, 
leaving only a little acetate in its place ; and though a small portion of sulphate of soda may 
still remain, it is unimportant, whereas the presence of any free sulphuric acid would be 
very injurious. This is easily detected by evaporating a little of the liquid, at a moderate 
heat, to dryness, when that mineral acid can be distinguished from the neutral soda sulphate. 
This plan of superseding a troublesome distillation, which is due to M. Mollerat, is one of 
the greatest improvements in this process, and depends upon the insolubility of the sulphate 
of soda in acetic acid. The sulphate of soda thus recovered, and well drained, serves anew 
to decompose acetate of lime ; so that nothing but this cheap earth is consumed in carrying 
on the manufacture. To obtain absolutely pure acetic acid, the above acid has to be distilled 
in a glass retort. 

Vfalckel recommends the use of hydrochloric instead of sulphuric acid for decomposing 
the acetate. 

The following is his description of the details of the process : — 

" The crude acetate of lime is separated from the tarry bodies which are deposited on 
neutralization, and evaporated to about one-half its bulk in an iron pan. Hydrochloric acid 
is then added until a distinctly acid reaction is produced on cooling ; by this means the 
resinous bodies are separated, and come to the surface of the boiling liquid in a melted 
state, whence they can be removed by skimming, while the compounds of lime, with creo- 
sote, and other volatile bodies, are likewise decomposed, and expelled on further evapora- 
tion. From 4 to 6 lbs. of hydrochloric acid for every 33 gallons of wood vinegar is the 
average quantity required for this purpose. The acetate, having been dried at a high tem- 
perature on iron plates, to char and drive off the remainder of the tar and resinous bodies, 
is then decomposed, by hydrochloric acid, in a still with a copper head and leaden condens- 
ing tube. To every 100 lbs. of salt about 90 to 95 lbs. of hydrochloric acid of specific 
gravity 1-16 are required. The acid comes over at a temperature of from 100° to 120° C. 
(212° to 248° F.), and is very slightly impregnated with empyreumatic products, while a 
mere cloud is produced in it by nitrate of silver. The specific gravity of the product varies 
from l - 058 to 1-061, and contains more than 40 per cent, of real acid ; but as it is seldom 
required of this strength, it is well to dilute the 90 parts of hydrochloric acid with 25 parts 
of water. These proportions then yield from 95 to 100 parts of acetic acid of specific 
gravity 1'015. 

This process is recommended on the score of economy and greater purity of product. 
The volatile empyreumatic bodies are said to be more easily separated by the use of hydro- 
chloric than sulphuric acid ; moreover, the chloride of calcium being a more easily fusible 
salt than the sulphate of lime, or even than the double sulphate of lime and soda, the acetic 
acid is more freely evolved from the mixture. The resinous bodies also decompose sulphuric 
acid towards the end of the operation, giving rise to sulphurous acid, sulphuretted hydrogen, 
&c, which contaminate the product. 

Impurities and Adulterations. — In order to prevent the putrefactive change which often 
takes place in vinegar when carelessly prepared by the fermentation of malt wine, &c, it 
was at one time supposed to be necessary to add a small quantity of sulphuric acid. This 
notion has long since been shown to be false ; nevertheless, since the addition of 1 part of 
sulphuric acid to 1,000 of vinegar was permitted by an excise regulation, and thus the 
practice has received legal sanction, it is still continued by many manufacturers. So long 
as the quantity is retained within these limits, and if pure sulphuric acid be used (great care 



being taken that there is no arsenic present in such oil of vitriol, as is not unfrequently the 
case in inferior varieties), no danger can ensue from the habit ; but occasionally the quantity 
is much overpassed by dishonest dealers, of whom it is to be hoped there are but few. 

Dr. Ure mentions having found, by analysis, in a sample of vinegar, made by one of the 
most eminent London manufacturers, with which he supplied the public, no less than l^o 
grains of the strongest oil of vitriol per gallon, added to vinegar containing only 3-^. per 
cent, of real acetic acid, giving it an apparent strength after all of only 4 per cent., whereas 
standard commercial vinegar is rated at 5 per cent. 

The methods of determining sulphuric acid will be given, once for all, under the head 
of Acidimetry, and therefore need not be described in every case where it occurs ; the 
same remark applies to hydrochloric acid and others. 

Hydrochloric acid is rarely intentionally added to vinegar ; but it may accidentally be 
present when the pyroligneous acid has been purified by Volckel's process. It is detected 
by the precipitate which it gives with solution of nitrate of silver in the presence of nitric acid. 

Nitric acid is rarely found in vinegar. For its method of detection, see Nitric Actd. 

Wine vinegar generally contains tartaric acid and tartrates ; but it is purified from them 
by distillation. 

Sulphurous acid is occasionally met with in pyroligneous acid. This is recognized by its 
bleaching action on delicate vegetable colors, and by its conversion, under the influence of 
nitric acid, into sulphuric acid, which is detected by chloride of barium. 

Sulphuretted hydrogen is detected by acetate of lead giving a black coloration or pre- 
cipitate. . 

Metallic Salts. — If care be not taken in constructing the worm of the still of silver or 
earthenware, distilled acetic acid is frequently contaminated with small quantities of metal 
from the still, copper, lead, tin, &c. These metals are detected by the addition of sulphu- 
retted hydrogen, as is fully discussed under the head of the individual metals. Copper is the 
most commonly found, and it may be detected in very minute quantities by the blue color 
which the solution assumes on being supersaturated with ammonia. 

It is not uncommon to add to pyroligneous acid, a little coloring matter and acetic ether, 
to give it the color and flavor of wine or malt vinegar ; but this can hardly be called an 

The presence of the products of acetification of eider may be detected by neutralizing 
the vinegar with ammonia, and then adding solution of acetate of lime. Tartrate of lime is, 
of course, precipitated from the wine vinegar, while the pearly malic acid of the cider affords 
no precipitate with the lime, but may be detected by acetate of lead, by the glistening pearly 
scales of malate of lea'd, hardly soluble in the cold. 

Acetic acid is extensively employed in the arts, in the manufacture of the various ace- 
tates, especially those of alumina and iron, so extensively employed in calico printing as 
mordants, sugar of lead, &c. It is likewise used in the preparation of varnishes, for dis- 
solving gums and albuminous bodies ; in the culinary arts, especially in the manufacture 
of pickles and other condiments ; in medicine, externally, as a local irritant, and internally, 
to allay fever, &c. 

For the treatment in cases of poisoning, we refer to Taylor, Pereira, and other medical 
authorities. — H. M. W. 

ACETIMETRY. Determination of the Strength of Vinegar. — If in vinegars we were 
dealing with mixtures of pure acetic acid and water, the determination of the density might, 
to a certain extent, afford a criterion of the strength of the solution ; but vinegar, especially 
that obtained from wine and malt, invariably contains gluten, saccharine, and mucilaginous 
matters, which increase its density and render this method altogether fallacious. 

The only accurate means of determining the strength of vinegar is by ascertaining the 
quantity of carbonate of soda or potash neutralized by a given weight of the vinegar under 
examination. This is performed by adding to the vinegar a standard solution of the alka- 
line carbonate of known strength from a bructte, until, after boiling to expel the carbonic 
acid, a solution of litmus previously introduced into the liquid is distinctly reddened. 

The details of this process, which is equally applicable to mineral and other organic 
acids, will be found fully described under the head of Acidimetry. 

Roughly, it may be stated that every 53 grains of the pure anhydrous carbonate of 
soda, or every 69 grains of carbonate of potassa (i. e. one equivalent), correspond to 60 
grains of acetic acid (C H 4 O 4 ).* 

It is obvious that preliminary examinations should be made to ascertain if sulphuric, 
hydrochloric, or other mineral acids are present ; and, if so, their amount determined, 
otherwise they will be reckoned as acetic acid. 

The British malt vinegar is stated in the London Pharmacopoeia to require a drachm 

* In most cases where, in commercial language, mention is made of real acetic acid, the hypotheti- 
cal compound C 4 H 3 3 is meant; but it would be better in future always to give the percentage of 
acetic acid C 4 IT 4 4 — for the bodyC 4 H 3 3 is altogether hypothetical — never having yet been discovered. 
See the remarks on Anhydrous Acetic Acid at the commencement of this article. — H. M. "W. 



(60 grains) of crystallized carbonate of soda (which contains 10 equivalents of water of 
crystallization) for saturating a fluid ounce, or 4-46 grains ; it contains, in fact, from 4 - 6 to 
5 per cent, of real acetic acid. 

The same authorities consider that the purified pyroligneous acid should require 87 
grains of carbonate of soda for saturating 100 grains of the acid. 

Dr. Ure suggests the use of the bicarbonate of potash. Its atomic weight, referred to 
hydrogen as unity, is 100*584, while the atomic weight of acetic acid is 51-563; if we 
estimate 2 grains of the bicarbonate as equivalent to 1 of the real acidj we shall commit no 
appreciable error. Hence a solution of the carbonate containing 200 grains in 100 
measures will form an acetimeter of the most perfect and convenient kind ; for the meas- 
ures of test liquid expended in saturating any measure — for instance, an ounce or 1,000 
grains of acid — will indicate the number of grains of real acetic acid in that quantity. 
Thus, 1,000 grains of the above proof would require 50 measures of the acetimetrical alka- 
line solution, showing that it contains 50 grains of real acetic acid in 1,000, or 5 per cent 

Although the bicarbonate of potash of the shops is not absolutely constant in compo- 
sition, yet the method is no doubt accurate enough for all practical purposes. 

The acetimetrical method employed by the Excise is that recommended by Messrs. J. 
and P. Taylor,* and consists in estimating the strength of the acid by the specific gravity 
which it acquires when saturated by hydrate of lime. Acid which contains 5 per cent, of 
real acid is equal in strength to the best malt vinegar, called by the makers No. 24, and is 
assumed as the standard of vinegar strength, under the denomination of " proof vinegar."f 
Acid which contains 40 per cent, of real acetic acid is, therefore, in the language of the 
Revenue, 35 per cent, over proof; it is the strongest acid on which duty is charged by the 
acetimeter. In the case of vinegars which have not been distilled, an allowance is made 
for the increase of weight due to the mucilage present ; hence, in the acetimeter sold by 
Bate, a weight, marked m, is provided, and- is used in trying such vinegars. As the hydrate 
of lime employed causes the precipitation of part of the mucilaginous matter in the vine- 
gar, it serves to remove this difficulty to a certain extent. (Pereira.) — H. M. W. 

AGETONE, syn. pyroacetic spirit, mesitic alcohol, pyroacetic ether. C 6 H 6 O 2 . A 
volatile fluid usually obtained by the distillation of the acetates of the alkaline earths. It 
is also obtained in a variety of operations where organic matters are exposed to high tem- 
perature. Tartaric and citric acids yield it when distilled. Sugar,, gum, or starch, when 
mixed with lime and distilled, afford acetone. If crude acetate of lime be distilled, the 
acetone is accompanied by a small quantity of ammonia and traces of methylamine. The 
latter is due to the nitrogen contained in the wood -, the distillate from which was used in 
the preparation of the acetate of lime. Crude acetone may be purified by redistilling it in 
a water-bath. A small quantity of slaked lime should be added previous to distillation, to 
combine with any acid that may be present. When pure, it forms a colorless mobile fluid, 
boiling at 133° F. Its density at 18° is 0-7921, at 32° it is 0-8140. The density of its 
vapor was found by experiment to be 2-00; theory requires 2.01, supposing six volumes of 
carbon vapor, twelve volumes of hydrogen, and two volumes of oxygen to be condensed 
to four volumes. When acetone is procured from acetate of lime, two equivalents of the 
latter are decomposed, yielding one equivalent of acetone, and two equivalents of car- 
bonate of lime. It has been found that a great number of organic acids, when distilled 
under similar circumstances, yield bodies bearing the same relation to the parent acid that 
acetone does to acetic acid : this fact has caused the word acetone to be used of late in a 
more extended sense than formerly. The word ketone is now generally used to express a 
neutral substance derived by destructive distillation from an acid, the latter losing the 
elements of an equivalent of carbonic acid during the decomposition. Theoretical chemists 
are somewhat divided with regard to the rational formula? of the ketones. An overwhelm- 
ing weight of evidence has been brought by Gerhardt and his followers, to prove that they 
should be regarded as aldehydes in which an equivalent of hydrogen is replaced by the 
radical of an alcohol. Thus common acetone (C 6 H G O 2 ) is aldehyde (C 4 H 4 O 2 ), in which 
one equivalent of hydrogen is replaced by methyle, C 2 H 3 . 

Acetone dissolves several gums and resins, amongst others sandarach. Wood spirit, 
which sometimes, owing to the presence of impurities, refuses to dissolve sandarach, may 
be made to do so by the addition of a small quantity of acetone. 

When treated with sulphuric acid and distilled, acetone yields a hydrocarbon called 
mesitylene or mesitylole, C 18 H 12 .— C. G. W. 

ACETYL. Two radicals are known by this name, namely, C 4 H 3 and C 4 II 3 2 . Their 
nomenclature has not, as yet, been definitely settled. Dr. Williamson proposes to call it 
othyl. The hydrocarbon C 4 H 3 is now assumed to exist in aldehyde, which can be regarded 
as formed on the type two atoms of water, thus : — 

In the above formula we have two atoms of water, in which 1 equivalent of hydrogen is 

* Quarterly Journal of Science, vi, 255. 

t BS Geo. III., e. 65. 



replaced by the non-oxidized radical C 4 H 3 , which may very conveniently be named aldyle, 
to recall its existence in aldehyde. — C. G. W. 

ACID. (Acidus, sour, L.) The term acid was formerly applied to bodies which were 
Bour to the taste, and in popular language the word is still so used. It is to be regretted 
that the necessities of science have led to the extension of this word to any bodies com- 
bining with bases to form salts, whether such combining body is sour or otherwise. Had 
not the term acid been established in language as expressing a sour body, there would have 
been no objection to its use ; but chemists now apply the term to substances which are not 
sour, and which do not change blue vegetable colors ; and consequently they fail to convey 
a correct idea to the popular mind. 

Hobbes, in his " Computation or Logic," says, " A name is a word taken at pleasure to 
serve for a mark which may raise in our mind a thought like to some thought we had 
before, and which, being pronounced to others, may be to them a sign of what thought the 
speaker had, or had not, before in his mind." This philosopher thus truly expresses the 
purpose of a name ; and this purpose is not fulfilled by the term acid, as now employed. 

Mr. John Stuart Mill, in his " System of Logic," thus, as it appears not very happily, 
endeavors to show that the term acid, as a scientific term, is not inappropriate or incorrect. 

" Scientific definitions, whether they are definitions of scientific terms, or of common 
terms used in a scientific sense, are almost always of the kind last spoken of : their main 
purpose is to serve as the landmarks of scientific classification. And, since the classifica- 
tions in any science are continually modified as scientific knowledge advances, the defini- 
tions in the sciences are also constantly varying. A striking instance is afforded by the 
words acid and alkali, especially the former. As experimental discovery advanced, the 
substances classed with acids have been constantly multiplying ; and, by a natural conse- 
quence, the attributes connoted by the word have receded and become fewer. At first it 
connoted the attributes of combining with an alkali to form a neutral substance (called a 
salt), being compounded of a base and oxygen, causticity to the taste and touch, fluidity, 
&c. The true analysis of muriatic acid into chlorine and hydrogen caused the second 
property, composition from a base and oxygen, to be excluded from the connotation. The 
same discovery fixed the attention of chemists upon hydrogen as an important element in 
acids ; and more recent discoveries having led to the recognition of its presence in sul- 
phuric, nitric, and many other acids, where its existence was not previously suspected, there 
is now a tendency to include the presence of this element in the connotation of the word. 
But carbonic acid, silica, sulphurous acid, have no hydrogen in their composition ; that 
property cannot, therefore, be connoted by the term, unless those substances are no longer 
to be considered acids. Causticity and fluidity have long since been excluded from the 
characteristics of the class by the inclusion of silica and many other substances in it ; and 
the formation of neutral bodies by combination with alkalis, together with such electro- 
chemical peculiarities as this is supposed to imply, are now the only differentia which form 
the fixed connotation of the word acid as a term of chemical science." 

The term Alkali, though it is included by Mr. J. S. Mill in connection with acid in his 
remarks, does not stand, even as a scientific term, in the objectional position in which we 
find acid. Alkali is not, strictly speaking, a common name to which any definite idea is 
attached. Acid, on the contrary, is a word commonl;/ employed to signify sour. With the 
immense increase which organic chemistry has given to the number of acids, it does appear 
necessary, to avoid confusion, that some new arrangement, based on a strictly logical plan, 
should be adopted. This is, however, a task for a master mind ; and possibly we must wait 
for another generation before such a mind appears among us. 

In this Dictionary all the acids named will be found under their respective heads ; as 
Acetic, Nitric, Sulphuric Acids, &e. 

ACIDIFIER. Any simple or compound body whose presence is necessary fof the pro- 
duction of an acid ; as oxygen, chlorine, bromine, iodine, fluorine, sulphur, &c, &c. 

ACIDIMETER. An instrument for measuring the strength or quantity of real acid 
contained in a free state in liquids. The construction of that instrument is founded on the 
principle that the quantity of real acid present in any sample is proportional to the quan- 
tity of alkali which a given weight of it can neutralize. The instrument, like the alkalim- 
eter (see Alkalimeter), is made to contain 1,000 grains in weight of pure distilled water, 
and is divided accurately into 100 divisions, each of which therefore represents 10 grains 
of pure distilled water ; but as the specific gravity of the liquids which it serves to measure 
may be heavier or lighter than pure water, 100 divisions of such liquids are often called 
1,000 grains' measure, irrespectively of their weight (specific gravity), and accordingly 
10-20, &c. divisions of the acidimeter are spoken of as 100-200, &c. grains' measure ; that 
is to say, as a quantity or measure which, if filled with pure water, would have weighed 
that number of grains. 

ACIDIMETRY. Acidimetry is the name of a chemical process of analysis by means 
of which the strength of acids — that is to say, the quantity of pure free acid contained in 
a liquid — can be ascertained or estimated. The principle of the method is based upon Dal- 



Saturate or neutralize 1 
eqv. = 49 parts in weight 
of pure oil of vitriol (sp. 
gr. 1-8485), or 1 equiv. 
of any other acid. 

ton's law of chemical combinations ; or, in other words, upon the fact that, in order to pro- 
duce a complete reaction, a certain definite weight of reagent is required. 

If, for example, we take 1 equivalent, or 49 parts in weight, of pure oil of vitriol of 
specific gravity 1 - S485, dilute it (of course within limits) with no matter what quantity of 
water, and add thereto either soda, potash, magnesia, ammonia, or their carbonates, or in 
fact any other base, until the acid is neutralized — that is to say, until blue litmus-paper is 
no longer, or only very faintly, reddened when moistened with a drop of the acid liquid 
under examination, — it will be found that the respective weights of each base required to 
produce that effect will greatly differ, and that with respect to the bases just mentioned 
these weights will be as follows : — 

Soda (caustic) 1 equiv. =31 parts in weight" 

Potash (caustic) " = 47 " 

Ammonia " = 17 " 

Carbonate of soda " = 53 " 

Carbonate of potash " = 69 " 

This beiDg the case, it is evident that if we wish to ascertain by such a method the quantity 
of sulphuric acid or of any other acid contained in a liquid, it will be necessary, on the one 
hand, to weigh or measure accurately a given quantity of that liquid to be examined, and, 
on the other hand, to dissolve in a known volume of water the weight above mentioned of 
any one of the bases just alluded to, and to pour that solution gradually into that of the 
acid until neutralization is obtained ; the number of volumes of the basic solution which 
will have been required for the purpose will evidently indicate the amount in weight of 
acid which existed in the liquid under examination. Acidimetry is therefore exactly the 
reverse of alkalimetry, since in principle it depends on the number of volumes of a solu- 
tion of a base diluted with water to a definite strength, which are required to neutralize a 
known weight or measure of the different samples of acids. 

The solution containing the known weight of base, and capable therefore of saturating 
a known weight of acid, is called a " test-liquor;" and an aqueous solution of ammonia, of 
a standard strength, as first proposed by Dr. Ure, affords a most exact and convenient 
means of effecting the purpose, when gradually poured from a graduated dropping-tube or 
acidimeter into the sample of acid to be examined. 

The strength of the water of ammonia used for the experiment should be so adjusted 
that 1,000 grains' measure of it (that is, 100 divisions of the alkalimeter) really contain one 
equivalent (17 grains) of ammonia, and consequently neutralize one equivalent of any one 
real acid. The specific gravity of the pure water of ammonia employed as a test for that 
purpose should be exactly - 992, and when so adjusted, 1,000 grains' measure (100 divisions 
of the acidimeter) will then neutralize exactly 

40 grains, or one equivalent, of sulphuric acid (dry). 

oil of vitriol, sp. gr. 1.8485. 
hydrochloric acid (gas, dry), 
nitric acid (dry), 
crystallized acetic acid, 
oxalic acid, 
tartaric acid, 
acetic acid. 





And so forth with the other acids. 

A standard liquor of ammonia of that strength becomes, therefore, a universal acid- 
imeter, since the number of measures or divisions used to effect the neutralization of 10 or 
of 100 grains of any one acid, being multiplied by the atomic weight or equivalent number 
of the acid under examination, the product, divided by 10 or by 100, will indicate the per- 
centage of real acid contained in the sample ; the proportion of free acid being thus 
determined with precision, even to Jj of a grain, in the course of five minutes, as will be 
shown presently. 

The most convenient method of preparing the standard liquor of ammonia of that 
specific gravity is by means of a glass bead, not but that specific gravity bottles and 
hydrometers may, of course, be employed ; but Dr. Ure remarks, with reason, that they 
furnish incomparably more tedious and less delicate means of adjustment. The glass bead, 
of the gravity which the test-liquor of ammonia should have, floats, of course, in the 
middle of such a liquor, at the temperature of 60° F. ; but if the strength of the liquor 
becomes attenuated by evaporation, or its temperature increased, the attention of the 
operator is immediately called to the fact, since the difference of a single degree of heat, or 
the loss of a single hundredth part of a grain of ammonia per cent., will cause the bead to 
sink to the bottom — a degree of precision which no hydrometer can rival, and which could 
not otherwise be obtained, except by the troublesome operation of accurate weighing. 
Whether the solution remains uniform in strength is best ascertained by introducing into 
the bottle containing the ammonia test-liquor two glass beads, so adjusted that one, being 

Vol. III.— 2 


very slightly heavier than the liquid, may remain at the bottom ; whilst the other, being 
very slightly lighter, reaches the top, and remains just under the surface as long as the 
liquor is in the normal state ; but when, by the evaporation of some ammonia, the liquor 
becomes weaker, and consequently its specific gravity greater, the bead at the bottom rises 
towards the surface, in which case a few drops of strong ammonia should be added to 
restore the balance. 

An aqueous solution of ammonia, of the above strength and gravity, being prepared the 
acidimetrical process is in every way similar to that practised in alkalimetry ; that is to say, 
a known weight, for example, 10 or 100 grains of the sample of acid to be examined are 
poured into a sufficiently large glass vessel, and diluted, if need be, with water, and a little 
tincture of litmus is poured into it, in order to impart a distinct red color to it ; 100 
divisions, or 1,000 grains' measure, of the standard ammonia test-liquor above alluded to, 
are then poured into an alkalimeter (which, in the present case, is used as an acidimeter), 
and the operator proceeds to pour the ammonia test-liquor from the alkalimeter into the 
vessel containing the acid under examination, in the same manner, and with the same 
precautions used in alkalimetry (see Alkalimetry), until the change of color, from red to 
blue, of the acid liquor in the vessel indicates that the neutralization is complete, and the 
operation finished. 

Let us suppose that 100 grains in weight of a sample of sulphuric acid, for example, 
have required 61 divisions (G10 water-grains' measure) of the acidimeter for their complete 
neutralization, since 100 divisions (that is to say, a whole acidimeter full) of the test-liquor 
of ammonia are capable of neutralizing exactly 49 grains — one equivalent — of oil of vitriol, 
of specific gravity, 1-8485, it is clear that the 61 divisions employed will have neutralized 
29 - 89 of that acid, and, consequently, the sample of sulphuric acid examined contained that 
quantity per cent, of pure oil of vitriol, representing 24 '4 per cent, of pure anhydrous 
sulphuric acid : thus — 

Divisions. Oil of Vitriol. 

100 : 49 :: 01 : x = 29-89. 

Anhydrous Acid. 
100 : 40 :: 61 : z = 24-4. 

The specific gravity of an acid of that strength is 1-2178. 

In the same manner, suppose that 100 grains in weight of hydrochloric acid have 
required 90 divisions (900 grains' measure) of the acidimeter for their complete neutraliza- 
tion, the equivalent of dry hydrochloric acid gas being 36-5, it is clear that since 90 divisions 
only of the ammonia test-liquor have been employed, the sample operated upon must have 
contained per cent, a quantity of acid equal to 33-30 of dry hydrochloric acid gas in solution, 
as shown by the proportion : — 

Divis. Hydrochloric acid. 
100 : 36-5 :: 90 : x = 32-85. 

The specific gravity of such a sample would be 1-1646. 

Instead of the ammonia test-liquor just alluded to, it is clear that a solution containing 
one equivalent of any other base — such as, for example, carbonate of soda, or carbonate of 
potash, caustic lime, &c. — may be used for the purpose of neutralizing the acid under 
examination. The quantity of these salts required for saturation will of course indicate the 
quantity of real acid, and, by calculation, the percentage thereof in the sample, thus : — The 
equivalent of pure carbonate of soda 53, and that of carbonate of potash 69, either of these 
weights will represent one equivalent, and consequently 49 grains of pure oil of vitriol, 36-5 
of dry hydrochloric acid, 60 of crystallized, or 51 of anhydrous acetic acid, and so on. The 
acidimetrical assay is performed as follows : — 

If with carbonate of soda, take 530 grains of pure and dry carbonate of soda, obtained 
by igniting the bicarbonate of that base (sec Alkalimetry), and dissolve them in 10,000 
water grains' measure (1,000 acidimetrical divisions) of distilled water. It is evident that 
each acidimeter full (100 divisions) of such a solution will then correspond to one equivalent 
of any acid ; and accordingly, if the test-liquor of carbonate of soda be poured from the 
acidimeter into a weighed quantity of any acid, with the same precautions as before, until 
the neutralization is complete, the number of divisions employed in the operation will, by 
simple rule of proportion, indicate" the quantity of acid present in the sample as before. 
Pure carbonate of soda is easily obtained by recrystallizing once or twice the crystals of'' 
carbonate of soda of commerce, and carefully washing them. By heating them gradually 
they melt, and at a very low red heat entirely lose their water of crystallization and become 
converted into pulverulent anhydrous neutral carbonate of soda, which should be kept in 
well closed bottles. 

When carbonate of potash is used, then, since the equivalent of carbonate of potash is 
69, the operator should dissolve 690 grains of it in the 10,000 grains of pure distilled water, 
and the acidimeter being now filled with this test-liquor, the assay is carried on again 
precisely in the same manner as before. Neutral carbonate of potash for acidimetrical use 



is prepared by heating the bicarbonate of that base to redness, in order to expel one 
equivalent of its carbonic acid ; the residue left is pure neutral carbonate of potash ; and in 
order to prevent its absorbing moisture, it should be put, whilst still hot, on a slab placed 
over concentrated sulphuric acid, or chloride of calcium, under a glass bell, and, when 
sufficiently cool to be handled, transferred to bottles carefully closed. 

To adapt the above methods to the French weights and measures, now used also gener- 
ally by the German chemist, we need only substitute 100 decigrammes for 100 grains, and 
proceed with the graduation as already described. 

A solution of caustic lime in cane sugar has likewise been proposed by M. Peligot for 
acidi metrical purposes. To prepare such a solution, take pure caustic lime, obtained by 
heating Carara marble among charcoal in a furnace ; when sufficiently roasted to convert it 
into quicklime, slake it with water, and pour upon the slaked lime as much water as is 
necessary to produce a milky liquor ; put this milky liquor iu a bottle, and add thereto, in 
the cold, a certain quantity of pulverized sugar-candy ; close the bottle with a good cork, 
and shake the whole mass well. After a certain time it will be observed that the milky 
liquid has become very much clearer, and perhaps quite limpid ; filter it, and the filtrate 
will be found to contain about 50 parts of lime for every 100 of sugar employed. The liquor 
should not be heated, because saccharate of lime is much more soluble in cold than in hot 
water, and if heat were applied it would become turbid or thick, though on cooling it would 
become clear again.* 

A concentrated solution of lime in sugar being thus obtained, it should now be diluted 
to such a degree that 1,000 water grains' measure of it may be capable of saturating exactly 
one equivalent of any acid, which is done as follows : — Take 100 grains of hydrochloric acid 
of specific gravity 1'1812, that weight of acid contains exactly one equivalent = 36 - 5 of 
pure hydrochloric acid gas ; on the other hand, fill the acidimeter up to (zero) with the 
solution of caustic lime in sugar prepared as abovesaid, and pour the contents into the acid 
until exact, neutralization is obtained, which is known by testing with litmus paper in the 
usual manner already described. If the whole of the 100 divisions of the acidimeter had 
been required exactly to neutralize the 100 grains 1 weight of hydrochloric acid of the specific 
gravity mentioned, it would have been a proof that it was of the right strength ; but suppose, 
on the contrary, that only 50 divisions of the lime solution in the acidimeter have been 
sufficient for the purpose, it is evident that it is half too strong, or, in other words, one 
equivalent of lime (=28) is contained in those 50 divisions instead of in*100. Pour, there- 
fore, at once, 50 divisions or measures of that lime-liquor into a glass cylinder accurately 
divided into 100 divisions, and fill up the remaining 50 divisions with water ; stir the whole 
well, and 100 divisions of the lime-liquor will, of course, now contain as much lime as was 
contained before in the 50 ; or, in other words, 100 acidimetrical divisions will now contain 
1 equivalent of lime, and therefore will be capable of exactly neutralizing 1 equivalent of 
any acid. 

When, however, saccharate of lime is used for the determination of sulphuric acid, it is 
necessary to dilute it considerably, for otherwise a precipitate of sulphate of lime would be 
produced. This reagent, moreover, is evidently applicable only to the determination of such 
acids the lime salts of which are soluble in water. 

Instead of a solution of caustic lime in sugar, a clean dry piece of white Carara marble 
may be used. Suppose, for example, that the acid to be assayed is acetic acid, the instruc- 
tions given by Brande are as follows : — A clean dry piece of marble is selected and accu- 
rately weighed ; it is then suspended by a silk thread into a known quantity of the vinegar 
or acetic acid to be examined, and which is cautiously stirred with a glass rod, so as to mix 
its parts, but without detaching any splinters from the weighed marble, till the whole of the 
acid is saturated, and no further action on the marble is observed. The marble is then taken 
out, washed with distilled water, and weighed ; the loss in weight which it has sustained 
may be considered as equal to the quantity of acetic acid present, since the atomic weight of 
carbonate of lime (=50) is very nearly the same as that of acetic acid (=51'). Such a 
process, however, is obviously less exact than those already described. 

But whichever base is employed to prepare the test-liquor, it is clear that the acid tested 
with it must be so far pure as not to contain any other free acid than that for which it is 
tested, for in that case the results arrived at would be perfectly fallacious. Unless, therefore, 
the operator has reason to know that the acid, the strength of which has to be examined by 
that process, is genuine of its kind, he must make a qualitative analysis to satisfy himself 
that it is so ; for in the contrary case the acid would not be in a fit state to be submitted to 
an acidimetrical assay. 

We shall terminate this article by a description of Liebig's acidimetrical method of 
determining the amount of prussic acid contained in solutions ; for example, in medicinal 
prussic acid, in laurel and bitter almond water, essence of bitter almonds, and cyanide of 
potassium. The process is based upon the following reaction : — When an excess of caustic 

_ * The directions given by M. Violette for the preparation of Sacclmrate of Lime are as follows: — 
Digest in the cold 50 grammes of slaked caustic lime in 1 litre of water containing 100 grammes of sugar. 


potash is poured in a solution which contains prussic acid, cyanide of potassium is, of 
course, formed ; and if nitrate of silver be then poured in such a liquor, a precipitate of 
cyanide of silver is produced, but it is immediately redissolved by shaking, because a double 
cyanide of silver and of potassium (Ag Cy -4- K Cy) is formed, which dissolves, without 
alteration, in the excess of potash employed. The addition of a fresh quantity of nitrate of 
silver produces again a precipitate which agitation causes to disappear as before ; and this 
reaction goes on until half the amount of prussic acid present in the liquor has been taken 
up to produce cyanide of silver, the other half being engaged with the potassium in the 
formation of a double cyanide of silver and of potassium, as just said. As soon, however, 
as this point is reached, any new quantity of nitrate of silver poured in the liquor causes 
the cyanide of potassium to react upon the silver of the nitrate, to produce a permanent 
precipitate of cyanide of silver, which indicates that the reaction is complete, and that the 
assay is terminated. The presence of chlorides, far from interfering, is desirable, and a 
certain quantity of common salt is accordingly added, the reaction of chloride of silver being 
analogous to that of the cyanide of the same metal. 

To determine the strength of prussic acid according to the above process, a test or normal 
solution should be first prepared, which is as follows : — 

Since 1 equivalent of nitrate of silver (=170) represents, as we have seen, 2 equivalents 
of prussic acid (=54), dissolve, therefore, 170 grains of pure fused nitrate of silver in 
10,000 water-grains' measure of pure water ; 1,000 water-grains' measure (1 acidimeter full) 
of such solution will therefore represent 5-4 grains of prussic acid ; and consequently each 
acidimetrical division - 054 grain of pure prussic acid. 

Take now a given weight or measure of the sample of prussic acid, or cyanide of potas- 
sium, or laurel, or bitter-almond water, or essence of bitter almonds ; dilute it with three or 
four times its volume of water, add caustic potash until the whole is rendered alkaline, and 
carefully pour into it a certain quantity of the normal silver solution from the acidimeter, 
until a slight precipitate begins to appear which cannot be redissolved by agitation ; observe 
the number of acidimetrical divisions of the test silver solution employed, and that number 
multiplied by - 054 will, of course, indicate the proportion of prussic acid present in the 
quantity of the sample operated upon. 

For such liquids which, like laurel water, contain very little prussic acid, it is advisable 
to dilute the test silver liquor with nine times its bulk of water ; a decimal solution is thus 
obtained, each acidimetrical division of which will only represent - 0054 of prussic acid, by 
which figure the number of divisions employed should then be multiplied. 

As the essence of bitter almonds mixed with water is turbid, it is absolutely necessary to 
add and shake it with a sufficient quantity of water to dissolve the particles of oil to which 
the milkiness is due, and render it quite clear. 

Instead of an acidimeter, an ordinary balance may be used, as follows : — Take 68 grains 
of fused nitrate of silver, and dissolve them in 5,937 grains' weight of pure distilled water, 
making altogether 6,000 grains' weight of test silver solution. Weigh off now in a beaker 
any quantity, say 100, or, if very weak, 1,000 grains' weight of the sample of prussic acid 
to be examined, dilute it with three or four times its bulk of water, mix with it a certain 
quantity of a solution of common salt, and a few drops of caustic potash over and above the 
quantity necessary to make it alkaline. Pour now carefully into the liquid so prepared a 
portion of the test solution of silver alluded to, until a turbidness or milkiness begins to be 
formed, which does not disappear by agitation, and which indicates that the reaction is 
complete. Every 300 grains of the test silver solution employed represent 1 grain's weight 
of pure anhydrous prussic acid. 

The rationale of these numbers is evident: since 1 equiv. = 170 of nitrate of silver 
corresponds to 2 equiv. = 54 of prussic acid ; 63 of nitrate of silver correspond to 20 of 
prussic acid, and consequently 300 of a solution containing 63 of nitrate of silver in 6,000 
correspond to 1 of prussic acid, thus : — 

170 : 54 :: 63 : 20 
6,000 : 20 :: 300 : 1 

Lastly, the strength of prussic acid may also be determined with an ordinary balance by 
a method proposed by Dr. Ure, which method, however, is much less convenient than that 
of Liebig ; it consists in adding peroxide of mercury, in fine powder, to the liquor which 
contains prussic acid, until it ceases to be dissolved. As the equivalent of peroxide of 
mercury = 108, is exactly four times that of prussic acid = 27, the weight of peroxide of 
mercury employed divided by four will give the quantity of prussic acid present. — A. N. 

ACIPENSER. See Isinglass. 

ACONITINE. C co H" NO 14 . A poisonous alkaloid constituting the active principle of 
the Aconite, Aconitum Napellus. — C. G. W. 

ACORNS. The seed of the oak (quercus). These possess some of the properties of the 
bark ; but in a very diluted degree. Acorns are now rarely used. Pigs are sometimes fed 
upon them, 308 bushels were imported in 1855. 



ACORTJS CALAMUS. The common sweet flag. This plant is a native of England, 
growing abundantly in the rivers of Norfolk ; from which county the London market is 
chiefly supplied. The radix calami aromatici of the shops occurs in flattened pieces about 
one inch wide, and four or five inches long. It is employed medicinally as an aromatic, and 
it is said to be used by some distillers to flavor gin. The essential oil {oleum acori calami) 
of the sweet flag is used by snuff-makers for scenting snuff, and it sometimes enters as one 
of the aromatic ingredients of aromatic vinegar. — Pereira. 

ACROSPIRE." {Plumule, Fr. ; Blattkeim, Germ.) The sprout at the end of seeds 
■when they begin to germinate. The name is derived from two Greek words, signifying 
highest and spire, and has been adopted on account of its spiral form. It is the plume or 
plumule of modern botanists. Malsters use the name to express the growing of the barley. 
" The first leaves that appear when corn sprouts." — Lindley. 

ACRYLAMINE or ALLYLAMNE. (C f H 7 N.) A new alkaloid obtained by Hoff- 
mann and Cahorns, by boiling cyanate of allyle with a strong solution of potash. It boils at 
about 363°.— C. G. TV". 

ACTINISM. (From o.kt\v, a ray ; signifying merely the power of a ray, without defining 
what character of ray is intended.) 

As early as 1812, M. Berard (in a communication to the Academy of Sciences, on some 
observations made by him of the phenomena of solar action) drew attention to the fact that 
three very distinct sets of physical powers were manifested. Luminous power, Heat-produc- 
ing power, and Chemical power. 

The actual conditions of the sun-beam will be understood by reference to the annexed 
woodcut, and attention to the following description, fig. 4: a b represents the prismatic 
spectrum — as obtained by the decomposition of white 

light by the prism — or Newtonian luminous spectrum, 4 5 

consisting of certain bands of color. Newton deter- 
mined those rays to be seven in number ; red, orange, 
yellow, green, blue, indigo, and violet ; recent re- 
searches, by Sir John Herschel and others, have proved 
the existence of two other rays ; one, the extreme red 
or crimson ray e, found at the least refrangible end of 
the spectrum, the other occurring at the most frangible 
end, or beyond the violet rays, which is a lavender or 
gray ray. Beyond this point up to/, Professor Stokes 
has discovered a new set of rays, which are only brought 
into view when the light is received upon the surfaces 
of bodies which possess the property of altering the 
refrangibility of the rays. Those rays have been called 
the fluorescent rays, from the circumstance that some 
of the varieties of Fluor Spar exhibit this phenomenon 
in a remarkable manner. In the engraving {fig. 4,) the 
curved line l from a to c indicates the full extent of 
the luminous spectrum, the point marked l showing 
the maximum of illuminating power, which exists in 
the yellow ray. 

Sir William Herschel and Sir Henry Englefield de- 
termined, in the first instance, the maximum point for 
the calorific rays, and Sir John Herschel subsequently 
confirmed their results, proving that the greatest heat 
was found below the red ray, and that it gradually 
diminished in power with the increase of refrangibility 
in the rays, ceasing entirely in the violet ray. Heat 
rays have been detected down to the point d, and the 
curved line h indicates the extent of their action. 

Now, if any substance capable of undergoing chemical change be exposed to this spec- 
trum, the result will be found to be such as is represented in the accompanying figure and 
fig. 5. Over the space upon which the greatest amount of light falls, i. e. the region of 
the yellow and orange rays l, no chemical change is effected : by prolonged action a slight 
change is brought about where the red ray falls, r, but from the mean green ray g up to 
the point /, a certain amount of chemical action is maintained ; the maximum of action 
being in the blue and violet rays a. Thus the curve line {fig. 4) from e to/ represents 
the extent and degree of chemical power as manifested in the solar spectrum. Two 
maxima are marked a a, differing widely however in their degree. 

ADHESION {sticking together). The union of two surfaces. "With the phenomena 
which are dependent upon bringing two surfaces so closely together that the influence of 
cohesion is exerted, we have not to deal. In arts and manufactures, adhesion is effected by 
interposing between the surfaces to be united, some body possessing peculiar properties, 



such as gum, plaster, resin, inarine or ordinary glue, and various kinds of cement. (See 
those articles.} In many treatises, there has been a sad confusion between the terms 
adhesion and cohesion. It is to be regretted that our literature shows a growing careless- 
ness in this respect. Adhesion should be restricted to mean, sticking together by means 
of some interposed substance ; cohesion, the state of union effected by natural attraction. 

Not only is adhesion exhibited in works of art or manufacture, we find it very strikingly 
exhibited in nature. Fragments of rocks which have been shattered by convulsion are 
found to be cemented together by silica, lime, oxide of iron, and the like. We sometimes 
find portions of stone cemented together by the ores of the metals ; and, again, broken 
parts of mineral lodes are frequently reunited by the earthy minerals. 

ADIPOSE SUBSTANCE or ADIPOSE TISSUE. (Tissu graisseux, Fr.) An animal 
oil, resembling in its essential properties the vegetable oils. During life, it appears to exist 
in a fluid or semi-fluid state ; but in the dead animal, it is frequently found in a solid form, 
constituting suet, which, when divested of the membrane in which it is contained, is called 
tallow. See Tallotv, Oils, &c. 

ADIT or ADIT LEVEL. The horizontal entrance to a mine ; a passage or level 
driven, into the hill-side. The accompanying section gives, for the purpose of distinctness, 

an exaggerated section of a portion of 
the subterranean workings of a metal- 
liferous mine. It should be understood 
that d represents a mineral lode, upon 
which the shaft, a, has been sunk. At 
a certain depth from the surface of the 
hill the miners would be inconvenienced 
by water, consequently a level is driven 
in from the side of the hill, 5, through 
which the wat£r flows off, and through 
which also the miner can bring out the 
broken rock, or any ores which he may 
obtain. Proceeding still deeper, sup- 
posing the workings to have com- 
menced, as is commonly the case, at a 
certain elevation above the sea-level, similar conditions to those described again arising, 
another level is driven so as to intersect the shaft or shafts, as shown at c. In this case, b 
would be called the shallow, and c the deep adit. The economy of such works as these is 
great, saving the cost of expensive pumping machinery, and, in many cases, saving also 
considerable labor in the removal of ores or other matter from the mine. 

ADZE. A cutting instrument ; differing from the axe by the edge being placed at 
nearly right angles to the handle, and being slightly curved up or inflected towards it. The 
instrument is held in both hands, whilst the operator stands upon his work in a stooping 
position ; the handle being from twenty-four to thirty inches long, and the weight of the 
blade from two to four pounds. The adze is swung in a circular path almost of the same 
curvature as the blade, the shoulder-joint being the centre of motion, and the entire arm 
and tool forming, as it were, one inflexible radius ; the tool, therefore, makes a succession 
of small arcs, and in each blow the arm of the workman is brought in contact with the 
thigh, which serves as a stop to prevent accident. In coarse preparatory works, the work- 
man directs his adze through the space between his two feet ; he thus surprises us by the 
quantity of wood removed ; in fine works he frequently places his toes over the spot to be 
wrought, and the adze penetrates two or three inches beneath the sole of the shoe ; and he 
thus surprises us by the apparent danger, yet perfect working of the instrument, which, in 
the hands of a shipwright in particular, almost rivals the joiner's plane ; it is with him the 
nearly universal paring instrument, and is used upon works in all positions. — Holtzapffel. 

AERATED WATER. The common commercial name of water artificially impregnated 
with carbonic acid. 

AEROLITES. Meteoric stones. It cannot be denied that masses of solid matter have 
fallen from the atmosphere upon the earth. 

It is evident that meteoric stones are of cosmical origin ; and the composition, there- 
fore, of such as have been examined, shows us the composition of masses of matter exist- 
ing beyond the earth. A few analyses of meteoric stones will exhibit the chemical charac- 
ter of these extraordinary masses. 

(2) (3) (4) 

90-88 . . 88-98 . . 86-64 

8-45 . . 10-35 . . 13-04 

0-65 . . . . 

0-02 . . 0-21 . . 0-27 

. . 0-34 . . 

. . 0-10 . . 0-05 

— Brook and Miller. 









AIR. 23 

A meteorite fell at Dharwar, in the East Indies, on the 15th of February, 1848, which gave 
5S - 3 per cent, of silicates insoluble in aqua regia ; 2'5 of sulphur, 6 - Y6 of nickel, and 
22.18-of iron. Another stone from Singhur, near Ponna, in the Deccan, gave earthly sili- 
cate, 19"5 ; iron, 69 - 16 ; and nickel, 4 - 24. Ehrenberg examined a black inky rain-water 
which fell in Ireland on the loth of April, 1S-19, and found the black color to consist of 
minute particles of decayed plants, which had probably been brought by the trade winds, 
and, floating in clouds of aqueous vapor, had decayed. 

AEROSTATION; AERONAUTICS. The ascent into the atmosphere by means of 
balloons. See Balloons. 

AGARIC of the oak ; called also surgeon's agaric, spunk, touchivood. A fungus found 
growing on the oak, birch, willow, and other trees. See Amadou. 

AGATE. An instrument used by gold-wire drawers, so called from the agate fixed in 
the middle of it. 

AGATE. (Agate, Fr. ; Achat, Gr. ;■ Achates, Lat.) A siliceous mineral ; a varie- 
gated variety of chalcedon}-. 

This stone is the 'Axdrns of the Greeks, by whom it was so called after the river in 
Sicily of that name, whence, according to Theophrastus, agates were first procured. Bo- 
chart, with much probability, deduces the name from the Punic and Hebrew, nakad, 

The colors of agate are either arranged in parallel or concentric bands, or assume the 
form of clouds or spots, or arborescent and moss-like stains. These colors are due to the 
presence of metallic oxides, and when indistinct, they are frequently artificially developed 
or produced. By boiling the colorless stone in oil, and afterwards in sulphuric acid, the oil 
is absorbed by the more porous layers of the stone ; it Subsequently becomes carbonized, 
and thus the contrast of the various colors is heightened. The red varieties, also, are arti- 
ficially produced by boiling them in a solution of proto-sulphate of iron ; after which, upon 
exposing the stones to heat, peroxide of iron is formed, and thus red bands, or rings, of 
varying intensities, are produced. Cornelians are thus very commonly formed ; the color- 
ing matter of the true stone being a peroxide of iron. 

Agates never occur in a crystalline form, but in the form of rounded pebbles ; they are 
translucent by transmitted light, but are not transparent, have a wax-like fracture, and they 
are susceptible of a brilliant polish. Agates are used in the arts for inlaying, and for bur- 
nishing gold and silver : they are also made into mortars for chemical purposes ; and when 
cut and polished, they are converted, in considerable quantities, into brooches, bracelets, 
and other ornamental articles. Agates are brought to this country from Arabia, India, and 
Oberstein, in Saxony : they are also found in Perthshire, and other parts of Scotland. The 
Scotch Pebble is a variety of the agate, known by its zig-zag pattern as the Fortification 
Agate. Agates are found frequently in the amygdaloid rocks of Galgenburg, near Ober- 
stein. They are usually ground into form, cut, and polished, at water-mills in the neigh- 
borhood, where a considerable trade in them is carried on. Moss Agate, or Mocha Stone, 
is a chalcedony, containing within it dendritic or moss-like delineations, of an opaque 
brownish-yellow color, which are due to oxide of manganese, or of iron. — H. W. B. 

Agates are found in the Canton markets, as articles of commerce, in abundance, and of 
the following varieties : — The white-veined agate, called also Mocha Stone, varies from 1 to 
8 inches in diameter. The dull, milky agate, not so valuable, occurs in sizes of 1 to 10 
inches. Lead-colored agate, sometimes uniform, and sometimes spotted, occurs of large 
size, and is used for cups and boxes. Flesh-colored. Blood-colored. This is sometimes 
variegated with pale blue and brown ; the blue always surrounds the red ; the brown has 
the tint of horn. Clouded and spotted flesh-colored agate is found subject to many flaws. 
Red agate, with yellow, is of 1 to 4 inches in diameter. The yellow has various tints. 
Sometimes the pebbles are 7 inches in length. The yellow agate is used for knife-handles. 
The pale yellow agate is very scarce ; it is called also Leonina, being variegated with white, 
black, and green, and bearing some resemblance to a lion's skin. Blackish-veined brown 
agate, in pieces from 2 to 7 inches in diameter, is very hard, and is cut into seals, buttons, 
and heads of canes, &c, with natural veins, or fictitious colors, sunk into the stone. It 
appears to be of much value. — Oriental Commerce. 

Agate is found sufficiently large to be formed into mortars for chemical purposes. 
" The royal collection at Dresden contains a table-service of German agate ; and at Vienna, 
in the Imperial cabinet, there is an oval dish, twenty-two inches in length, formed of a 
single stone." — Dana.. 

Agates may be stained artificially by soaking in a solution of nitrate of silver, and after- 
wards exposing them to the sun. These artificial colors disappear on laying the stone for a 
night in aquafortis. A knowledge of the practicability of thus staining agates naturally leads 
to the suspicion of many of the colors being the work, not of nature, but of art. 

AIR. The gaseous envelope which surrounds this Earth is emphatically so called ; it 
consists of the gases nitrogen and oxygen. 

About 79 measures of nitrogen, or azote, and 21 of oxygen, with T J 6 th of carbonic acid, 



constitute the air we breathe. The term air is applied to any permanently gaseous body. 
And we express different conditions of the air, as good air, bad air, foul air, &e. 

AIR-ENGINE. The considerable expansibility of air by heat naturally suggested its use 
as a motive power long before theoretical investigation demonstrated its actual value. The 
great advance made during the few last years in our knowledge of the mechanical action of 
heat, has enabled us to determine with certainty the practical result which may be obtained 
by the use of any contrivance for employing heat as a prime mover of machinery. We are 
indebted to Professor Wm. ' Thomson for the fundamental theorem which decides the 
economy of any thermo-dynamic engine. It is — that in any perfectly constructed engine 
the fraction of heat converted into work is equal to the range of temperature from the 
highest to the lowest point, divided by the highest temperature reckoned from the zero of 
absolute temperature. Thus, if we have a perfect engine in which the highest temperature 


is 280° and the lowest 80° F., the fraction of heat converted into force will be i. 

or rather more than one quarter. So that, if we use a coal of which one pound in combus- 
tion gives out heat equivalent to 10,380,000 foot pounds, such an engine as we have just 
described would produce work equal to 2,805,405 foot pounds for each pound of coal 
consumed in the furnace. From the above formula of Professor Thomson, it will appear 
that the economy of any perfect thermo-dynamic engine depends upon the range of tem- 
perature we can obtain in it. And as the lowest temperature is generally nearly constant, 
being ruled by the temperature of the surface of the earth, it follows that the higher we can 
raise the highest temperature, the more economical will be the engine. The question is 
thus reduced to this : — In what class of engine can we practically use the highest tempera- 
ture ? In the steam-engine worked with saturated vapor, the limit is obviously deter- 
mined by the amount of pressure which can be safely employed. In the steam-engine 
worked with super-heated vapor — i. e. in which the vapor, after passing from the boiler, 
receives an additional charge of heat without i)eing allowed to take up more water — and 
also in the air-engine, the limit will depend upon the temperature at which steam or air acts 
chemically upon the metals employed, as well as upon the power of the metals themselves 
to resist the destructive action of heat. It thus appears that the steam-engine worked with 
superheated steam possesses most of the economical advantages of the air-engine. But 
when we consider that an air-engine may be made available where a plentiful supply of 
water cannot be readily obtained, the importance of this kind of thermo-dynamic engine is 
incontestable. The merit of first constructing a practical air-engine belongs to Mr. Stirling. 
Mr. Ericsson has subsequently introduced various refinements, such as the respirator — a 
reticulated mass of metal, which, by its extensive conducting surface, is able, almost instan- 
taneously, to give its own temperature to the air which passes through it. But various 
practical difficulties attend these refinements, which, at best, only apply to engines worked 
between particular temperatures. The least complex engine, and that which would probably 
prove most effectual in practice, is that described in the "Philosophical Transactions," 
1852, Part I. It consists of a pump, which compresses air into a receiver, in which it 
receives an additional charge of heat ; and a cylinder, the piston of which is worked by the 
heated air as it escapes. The difference between the work produced by the cylinder and 
that absorbed by the pump constitutes the force of the engine ; which, being compared with 
the heat communicated to the receiver, gives results exactly conformable with the law of 
Professor Thomson above described. — J. P. J. 

Dr. Joule has proposed various engines to be worked at temperatures below redness, 
which, if no loss occurred by friction or radiation, would realize about one-half the work due 
to the heat of combustion ; or about four times the economical duty which has, as yet, been 
attained by the most perfect steam-engine. 

A detailed account of Ericsson's Calorific Engine may be useful, especially as a certain 
amount of success has attended his efforts in applying the expansive power of heat to move 
machinery. It is stated in Hunt's " Merchant's Magazine" that Ericsson's engines are at 
work in the foundry of Messrs. Hogg and Delamater, in New York ; one engine being of 
five and another of sixty-horse power. The latter has four cylinders. Two, of seventy-two 
inches in diameter, stand side by side. Over each of these is placed one much smaller. 
Within these are pistons exactly fitting their respective cylinders, and so connected, that 
those within the lower and upper cylinders move together. Under the bottom of each of 
the lower cylinders a fire is applied, no other furnaces being employed. Neither boilers nor 
water are used. The lower is called the working cylinder ; the upper, the supply cylinder. 
As the piston in the supply cylinder moves down, valves placed in its top, open, and it 
becomes filled with cold air. As the piston rises within it, these valves close, and the air 
within, unable to escape as it came, passes through another set of valves into a receiver, 
from whence it has to pass into the working cylinder to force up the working piston within 
it. As it leaves the receiver to perform this duty, it passes through what is called the 
regenerator, where it becomes heated to about 450° ; and upon entering the working cylin- 
der, it is further heated by the supply underneath. For the sake of illustration, merely, let 


us suppose that the working cylinder contains double the area of the supply cylinder : the 
cold air which entered the upper cylinder will, therefore, but only half fill the lower one. 
In the course of its passage to the latter, however, it passes through the regenerator ; and 
as it enters the working cylinder, we will suppose that it has become heated to about 480°, 
bv which it is expanded to double its volume, and with this increased capacity it enters the 
workino- cylinder. We will further suppose the area of the piston within this cylinder to 
contain 1,000 square inches, and the area of the piston in the supply cylinder above to 
contain but 500. The air presses upon this with a mean force, we will suppose, of about 
eleven pounds to, each square inch; or, in other words, with a weight of 5,500 pounds. 
Upon the surface of the lower piston the heated air is, however, pressing upwards with a 
like force upon each of its 1,000 square inches ; or, in other words, with a force which, 
after overcoming the weight above, leaves a surplus of 5,500 pounds, if we make no allow- 
ance for friction. This surplus furnishes the working power of the engine. It will be seen 
that after one stroke of its piston is made, it will continue to work with this force so long 
as sufficient heat is supplied to expand the air in the working cylinder to the extent stated ; 
for, so long as the area of the lower piston is greater than that of the upper and a like 
pressure is upon every square inch of each, so long will the greater piston push forward the 
smaller, as a two-pound weight upon one end of a balance will be sure to bear down a one- 
pound weight placed on the other. We need hardly say, that after the air in the working 
cylinder has forced up the piston within it, a valve opens ; and as it passes out, the pistons, 
by the force of gravity, descend, and cold air again rushes into and fills the supply cylinder. 
In this manner the "two cylinders are alternately supplied and discharged, causing the 
pistons in each to play up and down substantially as they do in the steam-engine. 

The regenerator must now be described. It has been stated that atmospheric air is first 
drawn into the supply cylinder, and that it passes through the regenerator into the working 
cylinder. The regenerator is composed of wire net, like that used in the manufacture of 
sieves, placed side by side, until the series attains a thickness of about 12 inches. Through 
the almost innumerable cells formed by the intersections of the wire, the air must pass on its 
way to the working cylinder. In passing through these it is so minutely divided that all 
parts are brought into contact with the wires. Supposing the side of the regenerator nearest 
the working cylinder is heated to a high temperature, the air, in passing through it, takes 
up, as we have said, about 450° of the 480° of heat required to double the volume of the 
air ; the additional 30° are communicated by the fire beneath the cylinder. 

The air has thus become expanded, it forces the piston upwards ; it has done its work 
— valves open, and the imprisoned air, heated to 480°, passes from the cylinder and again 
enters the regenerator, through which it must pass before leaving the machine. It has been 
said that the side of this instrument nearest the cylinder is kept hot ; the other side is kept 
cool by the action upon it of the air entering in the opposite direction at each up-stroke of 
the pistons ; consequently, as the air fr,om the working cylinder passes out, the wires absorb 
the heat so effectually, that when it leaves the regenerator it has been robbed of it all, 
except about 30°. 

The regenerator in the 60-horse engine measures 26 inches in height and width, inter- 
nally. Each disk of wire composing it contains 6*76 superficial inches, and the net has 10 
meshes to the inch. Each superficial inch, therefore, contains 100 meshes, which, multiplied 
by 676, gives 67,6<J8 meshes in each disk ; and, as 200 disks are employed, it follows that 
the regenerator contains 13,520,000 meshes; and consequently, as there are as many 
spaces between the disks as there are meshes, we find that the air within it is distributed in 
about 27,000,000 minute cells. Thence every particle of air, in passing through the regen- 
erator, is brought into very close contact with a surface of metal which heats and cools it 
alternately. Upon this action of the regenerator, Ericsson's Calorific Engine depends. In 
its application on the large scale, contemplated in the great Atlantic steamer called the 
" Ericsson," the result was not satisfactory. We may, however, notwithstanding this result 
safely predicate, from the investigation of Messrs. Thomson and Joule, that the expansion 
of air by heat will eventually, in some conditions, take the place of steam as a motive 

AIR-GUN". This is a weapon in which the elastic force of air is made use of to project 
the ball. It is so arranged, that in a cavity in the stock of the gun, air can be, by means of a 
piston, powerfully condensed. Here is a reserved force, which, upon its being relieved 
from pressure, is at once exerted. When air has been condensed to about J 5 of its bulk, 
it exerts a force which is still very inferior to that of gunpowder. In many other respects 
the air-gun is but an imperfect weapon, consequently it is rarely employed. 

AIRO-HYDROGEN BLOWPIPE. A blowpipe in which air is used in the place of 
oxygen, to combine with and give intensity of heat to a hydrogen flame for the purposes of 
soldering. See Autogenous Soldering. 

ALABASTER, Gypsum, Plaster of Paris (Albdtre, Fr. ; Alabaster, Germ.), a sulphate 
of lime. (See Alabaster, Oriental.) When massive, it is called indifferently alabaster or 
gypsum ; and when in distinct and separate crystals, it is termed sclenite. Massive alabas- 



ter occurs in Britain in the new red or keuper marl : in Glamorganshire, on the Bristol 
Channel ; in Leicestershire, at Syston ; at Tutbury and near Burton-on-Trent, in Stafford- 
shire ; at Chellaston, in Derbyshire ; near Droitwich it is associated in the marl with rock 
salt, in strata respectively 40 and 75 feet in thickness ; and at Northwich and elsewhere the 
red marl is intersected with frequent veins of gypsum. At Tutbury it is quarried in the 
open air, and at Chellaston in caverns, where it is blasted by gunpowder ; at both places it 
is burned in kilns, and otherwise prepared for the market. It lies in irregular beds in the 
marl, that at Chellaston being about 30 feet thick. There is, however, reason to suppose 
that it was not originally deposited along with the marl as sulphate of lime, but rather that 
calcareous strata, by the access of sulphuric acid and water, have been converted into sul- 
phate of lime, — a circumstance quite consistent with the bulging of the beds of marl with 
which the gypsum is associated, the lime, as a sulphate, occupying more space than it did in 
its original state as a carbonate. At Tutbury and elsewhere, though it lies on a given 
general horizon, yet it can scarcely be said to be truly bedded, but ramifies among the beds 
and joints of the marl in numerous films, veins, and layers of fibrous gypsum. 

A snow-white alabaster occurs at Volterra, in Tuscany, much used in works of art in 
Florence and Leghorn. In the Paris basin it occurs as a granular crystalline rock, in the 
Lower Tertiary rocks, known to geologists as the upper part of the Middle Eocene fresh- 
water strata. It is associated with beds of white and green marls ; but in the Thuringewald 
there is a great mass of sulphate of lime in the Permian strata. It has been sunk through 
to a depth of 10 feet, and is believed to be metamorphosed magnesian limestone or Zech- 
stein. In the United States this calcareous salt occurs in numerous lenticular masses in 
marly and sand strata, of that part of the Upper Silurian strata known as the Onondaga salt 
group. It is excavated for agricultural purposes. For mineralogical character, &c, see 
Gypsum.— A. C. R. 

The gypsum of our own country is found, in apparently inexhaustible quantities, in the 
red marl formation in the neighborhood of Derby, and has been worked for many centuries. 
The great bulk of it is used for making plaster of Paris, and as a manure ; and it is the 
basis of many kinds of cements, patented — as Keene's, Martin's, and others. 

To get it for these purposes, it is worked by mining underground, and the stone is 
blasted by gunpowder ; but this shakes it so much as to be unfit for working into orna- 
ments, &c. ; to procure blocks for which it is necessary to have an open quarry. By 
removing the superincumbent marl, and laying bare a large surface of the rock, the alabaster 
being very irregular in form, and jutting out in several parts, allows of its being sawn out 
in blocks of considerable size, and comparatively sound, (as is illustrated by the large tazza 
in the Museum of Practical Geology.) This stone, when protected from the action of water, 
is extremely durable, as may be seen in churches all over the country, where monumental 
effigies, many centuries old, are now as perfect as the day they were made, excepting, of 
course, wilful injuries ; but exposure to rain soon decomposes the stone, and it must be 
borne in mind that it is perfectly unsuited for garden vases or other out-door work in this 

In working, it can be sawn up into slabs with toothed saws, and for working mouldings 
and sculptures, fine chisels, rasps, and files are the implements used ; the polishing is per- 
formed by rubbing it with pieces of sandstone, of various degrees of fineness, and water, 
until it is quite free from scratches, and then giving a gloss by means of polishing powder 
(oxide of tin) applied on a piece of cloth, and rubbed with a considerable degree of friction 
on the stone. This material gives employment in Derby to a good many hands in forming 
it into useful and ornamental articles, and is commonly called Derbyshire Spar ; most of 
the articles are turned in the lathe, and it works something like very hard wood. 

Another kind of gypsum also found in Derbyshire is the fibrous or silky kind ; it occurs 
in thin beds, from one to six inches in depth, and is crystallized in long needle-like fibres ; 
being easily worked, susceptible of a high polish, and quite lustrous, it is used for making 
necklaces, bracelets, brooches, and such like small articles. — S. H. 

ALABASTER, ORIENTAL. Oriental alabaster is a form of stalagmitic or stalactitic 
carbonate of lime, an Egyptian variety of which is highly esteemed. ■« It is also procured 
from the Pyrenees, from Chili, and from parts of the United States of America. Ancient 
quarries are still in existence in the province of Oran, in Algeria. 

ALBATA PLATE, a name given to one of the varieties of white metal now so com- 
monly employed. See Copper, and Allots. 

ALBUM GRJ5CUM. The white faeces of dogs. After the hair has been removed 
from skins, this is used to preserve the softness of them, and prepare them for the tan-pit. 
Fowls' dung is considered by practical tanners as superior to the dung of dogs, and this is 
obtained. as largely as possible. These excreta may be said to be essentially phosphate of 
lime and mucus. We are informed that various artificial compounds which represent, 
chemically, the conditions of those natural ones, have been tried without producing the 
same good results. It is a reflection on our science, if this is really the ease. 

ALBUMEN. (Album Ovi.) Albumen is a substance which forms a constituent part 


of the animal fluids and solids, and which is also found in the vegetable kingdom. It 
exists nearly pure in the white of egg. Albumen consists of— 

Carbon, 53-32 

Hydrogen, ...... 7'29 

Nitrogen, ....... 15'7 

Sulphur, . . . • ■ • 1*3 

Oxygen, ....... 22'39 

Its Formula being S 2 N 27 C 210 H i(ra O 68 . Albumen coagulates by heat, as is illustrated in 
the boiling of an°egg. The salts of tin, bismuth, # lead, silver, and mercury form with 
albumen white insoluble precipitates; therefore, in* cases of poisoning by corrosive sub- 
limate, nitrate of silver, or sugar of lead, the white of egg is the best antidote which can 
be administered. 

Albumen is employed in Photography, which see. 

"We imported the following quantities of albumen: — in 1835, 275 cwts. ; in 1856, 
382 cwts. 

ALCOHOL. (Alcool, Fr. ; Alkohol, or Weingeist, Germ.) The word alcohol is de- 
rived from the Hebrew word " kohol," "pns to paint. The oriental females were and are 
still in the habit of painting the eyebrows with various pigments ; the one generally em- 
ployed was a preparation of antimony, and to this the term was generally applied. It 
became, however, gradually extended to all substances used for the purpose, and ultimately 
to strong spirits, which were employed, probably, as solvents for certain coloring principles. 
The term was subsequently exclusively used to designate ardent spirits, and ultimately the 
radical or principle upon which their strength depends. 

As chemistry advanced, alcohol^ was found to be a member only of a class of bodies 
agreeing with it in general characters ; and hence the term is now generic, and we speak 
of the various alcohols. Of these, common or vinous alcohol is the best known ; and, in 
common life, by " alcoholic liquors," we invariably mean those containing the original or 
vinous alcohol. ' 

When the characters of ordinary alcohol have been stated, allusion will be made to the 
class of bodies of whk;h this is the type. 

Fermented liquors were known in the most remote ages of antiquity. We read (Gene- 
sis ix.) that after the flood " Noah planted a vineyard, and he drank of the wine and was 
drunken." Homer, who certainly lived 900 years before the Christian era, also frequently 
mentions wine, and notices its effects on the body and mind (Odyssey IX. and XXI.) ; and 
Herodotus tells us that the Egyptians drank a liquor fermented from barley. The period 
when fermented liquors were submitted to distillation, so as to obtain " ardent spirits" is 
shrouded in much obscurity. Raymond Lully* was acquainted with " spirits of wine," which 
he called aqua ardens. The separation of absolute alcohol would appear to have been 
first effected about this period (1300), by Arnauld de Villeneuve, a celebrated physician 
residing in Montpellier (Gerhardt), and its analysis was first performed by Th. de 

The preparation of alcohol may be divided into three stages : — 

1. The production of a fermented vinous liquor — the Fermentation. 

2. The preparation from this of an ardent spirit — the Distillation. 

3. The separation from this ardent spirit of the last traces of water — the Rectification. 
1. Fermentation. The term "fermentation" is now applied to those mysterious 

changes which vegetable (and animal) substances undergo when exposed, at a certain tem- 
perature, to contact with organic or even organized bodies in a state of change. 

There are several bodies which suffer these metamorphoses, and under the influence of 
a great number of different exciting substances, which are termed the " ferments ;" more- 
over, the resulting products depend greatly upon the temperature at which the change takes 

The earliest known and best studied of these processes is the one commonly recognized 
as the vinous or alcoholic fermentation. 

In this process solutions containing sugar — either the juice of the grape (see Wine) or 
an infusion of germinated barley, malt, (see Beer) — are mixed with a suitable quantity of 
a ferment ; beer or wine yeast is usually employed (see Yeast), and the whole maintained 
at a temperature of between 70° and 80° F. (21° to 26° C.) 

Other bodies in a state of putrefactive decomposition will effect the same result as the 
yeast, such as putrid blood, white of egg, &c. 

The liquid swells up, a considerable quantity of froth collects on the surface, and an 
abundance of gas is disengaged, which is ordinary carbonic acid (CO 2 ). The composition 
of (pure) alcohol is expressed by the formula C 4 H° O 2 , and it is produced in this process 

* Thomson's History of Chemistry, i. 41. (1830.) t Annalcs do Chimic, xlii. '225. 



by the breaking up of an equivalent of grape sugar, C' 4 H 2e O 21 
hoi, 8 of carbonic acid, and 4 of water — 

into 4 equivalents of alco- 

24 TTMI fV28 

O 8 = 4 (C 4 H 6 2 ) 

H 4 

II 4 

4 HO 


O le = 8 CO 2 

It is invariably the grape sugar which undergoes this change ; if the solution contains 
cane sugar, the cane sugar is first converted into grape sugar under the influence of the 
ferment. See Sugar. 

Much diversity of opinion exists with respect to the office which the ferment performs 
in this process, since it does not itself yield any of the products. See Fermentation. 

The liquid obtained by the vinous fermentation has received different names, according 
to the source whence the saccharine solution was derived. When procured from the ex- 
pressed juice of fruits — such as grapes, currants, gooseberries, &c. — the product is denomi- 
nated wine ; from a decoction of malt, ale or beer ; from a mixture of honey and water, 
mead; from apples, cider ; from the leaves and small branches of the spruce-fir (abies 
excelsa, &c), together with sugar or treacle, spruce ; from rice, rice beer (which yields the 
spirit arrack) ; from cocoa-nut juice, palm wine. 

It is an interesting fact that alcohol is produced in very considerable quantities (in the 
aggregate) during the raising of bread. The carbonic acid which is generated in the dough, 
and which during its expulsion raises the bread, is one of the products of the fermentation 
of the sugar in the flour, under the influence of the yeast added ; and of course at the 
same time the complementary product, alcohol, is generated. As Messrs. Ronalds and 
Richai'dson remark :* " The enormous amount of bread that is baked in large towns — in 
London, for instance, 8.8 millions of cwts. yearly — would render the small amount of 
alcohol contained in it of sufficient importance to be worth collecting, provided this could 
be done sufficiently cheaply." In London it has been estimated that in this way about 
300,000 gallons of spirits are annually lost ; but the cost of collecting it would far exceed 
its value. 

2. Distillation. By the process of distillation, ardent spirits are obtained, which have 
likewise received different names according to the sources whence the fermented liquor has 
been derived : viz. that produced by the distillation of wine being called brandy, and in 
France cognac, or eau de vie ; that produced by the distillation of the fermented liquor 
from sugar and molasses, rum. There are several varieties of spirits made from the fer- 
mented liquor procured from the cereals (and especially barley), known according to their 
peculiar methods of manufacture, flavor, &c. — as whiskey, gin, Hollands — the various 
compounds and liqueurs. In India, the spirit obtained from a fermented infusion of rice 
is called arrack. 

3. Rectification ;. preparation of absolute alcohol. It is impossible by distillation alone 
to deprive spirit of the whole of the water and other impurities — to obtain, in fact, pure or 
absolute alcohol. 

This is effected by mixing with the liquid obtained after one or two distillations, certain 
bodies which have a powerful attraction for water. The agents commonly employed for 
this purpose are quicklime, carbonate of potash, anhydrous sulphate of copper, or chloride 
of calcium. Perhaps the best adapted for the purpose, especially where large quantities 
are required, is quicklime ; it is powdered, mixed in the retort with the spirit (previously 
twice distilled), and the neck of the retort being securely closed, the whole left for 24 
hours, occasionally shaking ; during this period the lime combines with the water, and then 
on carefully distilling, avoiding to continue the process until the last portions come over, an 
alcohol is obtained which is free from water. If not quite free, the same process may be 
again repeated. 

In experiments on a small scale, an ordinary glass retort may be employed, heated by a 
water-bath, and fitted to a Liebig's condenser cooled by ice-water, which passes lastly into a 
glass receiver, similarly cooled. 

Although alcohol of sufficient purity for most practical purposes can be readily ob- 
tained, yet the task of procuring absolute alcohol entirely free from a trace of water, is by 
no means an easy one. 

Mr. Drinkwater f effected this by digesting ordinary alcohol of specific gravity .850 at 
60° F. for 24 hours with carbonate of potash previously exposed to a red heat ; the alcohol 
was then carefully poured off and mixed in a retort with as much fresh-burnt quicklime as 
was sufficient to absorb the whole of the alcohol ; after digesting for 48 hours, it was slowly 

* Chemical Technology, by Dr. F. Knapp : edited hy Messrs. Eonalds and Richardson. Vol. iii. 108. 
t On the Preparation of Absolute Alcohol, and the Composition of Proof Spirit. See Memoirs of the 
Chemical Society, vol. iii. p. 447. 


distilled in a water-bath at a temperature of about 180° F. This alcohol was carefully re- 
distilled, and its specific gravity at 60° F. found to be -7947, which closely agrees with that 
given by Gay-Lussae as the specific gravity of absolute alcohol. He found, moreover, that 
recently ignited anhydrous sulphate of copper was a less efficient dehydrating agent than 

Graham recommends that the quantity of lime employed should never exceed three 
times the weight of the alcohol. 

Chloride of calcium is not so well adapted for the purification of alcohol, since the 
alcohol forms a compound with this salt. 

Many other processes have been suggested for depriving alcohol of its water. 

A curious process was proposed many years ago by Soemmering,* which is dependent 
upon the peculiar fact, that whilst water moistens animal tissues, alcohol does not, but tends 
rather to abstract water from them. If a mixture of alcohol and water be enclosed in an 
ox bladder, the water gradually traverses the membrane and evaporates, whilst the alcohol 
does not, and consequently by the loss of water the spirituous solution becomes con- 
" centrated. 

This process, though an interesting illustration of exosmose, is not practically applicable 
to the production of anhydrous alcohol ; it is, however, an economical method, and well 
suited for obtaining alcohol for the preparation of varnishes. Smugglers, who bring spirits 
into France in bladders hid about their persons, have long known, that although the liquor 
decreased in bulk, yet it increased in strength ; hence the people preferred the article con- 
veyed clandestinely. Prof. Graham has ingeniously proposed to concentrate alcohol as follows : 

" A large shallow basin is covered, to a small depth, with recently burnt quicklime, in 
coarse powder, and a smaller basin, containing three or four ounces of commercial alcohol, 
is made to rest upon the lime ; the whole is placed under the low receiver of an air-pump, 
and the exhaustion continued till the alcohol evinces signs of ebullition. Of the mingled 
vapors of alcohol and water which now fill the receiver, the quicklime is capable of uniting 
with the aqueous only, which is therefore rapidly withdrawn, while the alcohol vapor is un- 
affected ; and as water cannot remain in the alcohol as long as the superincumbent atmos- 
phere is devoid of moisture, more aqueous vapor rises, which is likewise abstracted by the 
lime, and thus the process goes on till the whole of the water in the alcohol is removed. 
Several days are always required for this purpose. 

Properties of Alcohol. — Absolute. 

In the state of purity, alcohol is a colorless liquid, highly inflammable, burning with a 
pale blue flame, very volatile, and having a density of 0792 at 15-5° C. (60° F.) {Drink- 
water.) It boils at 78-4° C. (173° F.) It has never yet been solidified, and the density of 
its vapor is 1'6133. 

Anhydrous alcohol is composed by weight of 5248 carbon, 13-04 hydrogen, and 34-78 
of oxygen. It has for its symbol C 4 H 6 0'- = C* H 5 4- HO, or hydrated oxide of ethyle. 
It has a powerful affinity for water, removing the water from moist substances with which 
it is brought in contact. In consequence of this property, it attracts water from the air, 
and rapidly becomes weaker, unless kept in very well-stopped vessels. In virtue of its 
attraction for water, alcohol is very valuable for the preservation of organic substances, and 
especially of anatomical preparations, in consequence of its causing the coagulation of 
albuminous substances ; and for the same reason it causes death when injected into the veins. 

When mixed with water a considerable amount of heat is evolved, and a remarkable 
contraction of volume is observed ; these effects being greatest with 54 per cent, of alco- 
hol and 46 of water, and thence decreasing with a greater proportion of water. For alco- 
hol which contains 90 per cent, of water, this condensation amounts to 1-94 per cent, of 
the volume ; for 80 per cent, 2-87 ; for 70 per cent., 3-44 ; for 60 per cent., 3'73 ; for 40 
per cent., 344 ; for 30 per cent, 2-72 ; for 20 per cent, 1-72 ; for 10 per cent, 0-72. 

Alcohol is prepared absolute for certain purposes, but the mixtures of alcohol and water 
commonly met with in commerce are of an inferior strength. Those commonly sold are 
"Rectified Spirit,'' and "Proof Spirit" 

"Proof Spirit" is defined by Act of Parliament, 58 Geo. III. c. 28, to be "such as 
shall, at the temperature of fifty-one degrees of Fahrenheit's thermometer, weigh exactly 
twelve-thirteenth parts of an equal measure of distilled water." And by very careful experi- 
ment, Mr. Drinkwater has determined that this proof spirit has the following composition: — 

Alcohol and Water. 

Specific Gravity 
at CO 1 F. 

Bulk of the mixture of 

100 measures of Alcohol, 

and 81-82 of Water. 

By weight. 

By measure. 

Alcohol. "Water. 

100 + 103-09 

49-100 -f 50-76 

Alcohol. -Water. 
100 -4- 81-82 



* Soemmering. "Denkschriften d. K. Akad. d. Wissenchaften zu Miinschen," ITU to 1S24. 



Spirit which is weaker is called "under proof;" and that stronger, "above proof." 
The origin of these terms is as follows : — Formerly a very rude mode of ascertaining the 
strength of spirits was practised, called the proof ; the spirit was poured upon gunpowder 
and inflamed. If, at the end of the combustion, the gunpowder took fire, the spirit was 
said to be above or over proof. But if the spirit contained much water, the powder was 
rendered so moist that it did not take fire : in which case the spirit was said to be under or 
below proof. 

Rectified spirit contains from 54 to 64 per cent, of absolute alcohol ; and its specific 
gravity is fixed by the London and Edinburgh Colleges of Physicians at 0-838, whilst the 
Dublin College fixes it at 0.840. 

In commerce the strength of mixtures of alcohol and water is stated at so many 
degrees, according to Sykes's hydrometer, above or below proof. This instrument will be 
explained under the head of Alcoholometry. 

As will have been understood by the preceding remarks, the specific gravity or density 
of mixtures of alcohol and water rises with the diminution of the quantity of alcohol present ; 
or, in other words, with the amount of water. And since the strength of spirits is deter- 
mined by ascertaining their density, it becomes highly important to determine the precise 
ratio of this increase. This increase in density, with the amount of water, or diminution 
with the quantity of alcohol, is, however, not directly proportional, in consequence of the 
contraction of volume which mixtures of alcohol and water suffer. 

It therefore became necessary to determine the density of mixtures of known composi- 
tion, prepared artificially. This has been done recently with great care by Mr. Drink- 
water ;* and the following table by him is recommended as oneof the most accurate : 

Table of the Quantity of Alcohol, by weight, contained in Mixtures of Alcohol and 
Water of the following Specific Gravities: — 



cent, by 



cent, by 


Alcohol, | 




per cent. 


Gravity at 
60° F. 

at 00° F. 

at 60° F. 

pei ( 
cent, by 

t 60° F. 

per ( 
cent, by 

t 60° F. 











































































































•9891 . 



















































































































































































































7-78 ■ 










* Memoirs of tlio Chemical Society, vol. iii. p. 434. 



The preceding table, though very accurate so far as it goes, is not sufficiently extensive 
for practical purposes, only going, in fact, from 6 to 10 per cent, of alcohol ; the table of 
Trailed (below) extends to 50 per cent, of absolute alcohol. 

Moreover, Drinkwater's table has the (practical) disadvantage (though scientifically more 
correct and useful) of stating the percentage by weight ; whereas, in Tralle's table, it is givan 
by volume. And since liquors are vended by measure, and not by weight, the centesimal 
amount by volume is usually preferred. But as the bulk of liquids generally, and par- 
ticularly that of alcohol, is increased by heat, it is necessary that the statement of the den- 
sity in a certain volume should have reference to some normal temperature. In the 
construction of Tralle's table the temperature of the liquids was 60° F. ; and, of course, in 
using it, it is necessary that the density should be observed at that temperature. 

In order to convert the statement of the composition by volume into the content by 
weight, it is only necessary to multiply the percentage of alcohol by volume by the specific 
gravity of absolute alcohol, and then divide by the specific gravity of the liquid. 

Tralle's Table of the Composition, by volume, of Mixtures of Alcohol and Water of 

different Densities. 





Gravity at 

60° F. 

ence of 
the spe- 
cific gra- 





Gravity at 

60° F. 

ence of 
the spe- 
cific gra- 





Gravity at 

60° F. 

ence of 
the spe- 
cific gra- 












. 0-9583 












' 0-8892 






















































































































































































































































































In order, however, to employ this table for ascertaining the strength of mixtures of 
alcohol and water of different densities (which is the practical use of such tables), it is 
absolutely necessary that the determination of the density should bo performed at an inva- 
riable temperature, — viz. 60° F. The methods of determining the density will be hereafter 
described ; but it is obvious that practically the experiment cannot be conveniently made at 
any fixed temperature, but must be performed at that of the atmosphere. 



The boiling point of mixtures of alcohol and water likewise differs with the stength of 
such mixtures. 

According to Gay-Lussac, absolute alcohol boils at 78-4° C. (173° F.) under a pressure of 
760 millimetres (the millimetre being 0'03937 English inches). When mixed with water, 
of course its boiling point rises in proportion to the quantity of water present, as is the case 
in general with mixtures of two fluids of greater and less volatility. A mixture of alcohol 
and water, however, presents this anomaly, according to Soemmering : when the mixture 
contains less than six per cent, of alcohol, those portions which first pass off are saturated 
with water, and the alcoholic solution in the retort becomes richer, till absolute alcohol 
passes over ; but when the mixture contains more than six per cent, of water, the boiling 
point rises, and the quantity of alcohol in the distillate steadily diminishes as the distillation 

According to Groning's researches, the following temperatures of the alcoholic vapors 
correspond to the accompanying contents of alcohol in percentage of volume which are 
disengaged in the boiling of the spirituous liquid. 

Alcoholic con- 

Alcoholic con- 

Alcoholic con- 

Alcoholic con- 


tent of the 

tent of the 


tent of the 

tent of the 


boiling liquid. 


boiling liquid. 

Fahr. 170-0 



Fahr. 189-8 
































































Groning undertook this investigation in order to employ the thermometer as an alcoho- 
lometer in the distillation of spirits ; for which purpose he thrust the bulb of the thermom- 
eter through a cork inserted into a tube fixed in the capital of the still. The state of the 
barometer ought also to be considered in making comparative experiments of this kind. 
Since, by this method, the alcoholic content may be compared with the temperature of the 
vapor that passes over at any time, so, also, the contents of the whole distillation may be 
found approximately ; and the method serves as a convenient means of making continual 
observations on the progress of the distillation. 

Density of the Vapor. — One volume of alcohol yields 488-3 volumes of vapor at 212° 
F. The specific gravity of the vapor, taking air as unity, was found by Gay-Lussac to be 
1-6133. [Its vapor-density, referred to hydrogen, as unity, is 13-3605 ?] 

Spirituous vapor passed through an ignited tube of glass or porcelain is converted into 
carbonic oxide, water, hydrogen, carburetted hydrogen, defiant gas, naphthaline, empyreu- 
matic oil, and carbon; according to the degree of heat and nature of the 'tube, these 
products vary. Anhydrous alcohol is a non-conductor of electricity, but is decomposed by 
a powerful voltaic battery. Alcohol burns in the air with a blue flame into carbonic acid 
and water ; the water being heavier than the spirit, because 46 parts of alcohol contain 6 
of hydrogen, which form 54 of water. In oxygen the combustion is accompanied with 
great heat, and this flame, directed through a small tube, powerfully ignites bodies exposed 
to it. 

Platinum in a finely divided state has the property of determining the combination of 
alcohol with the oxygen of the air in a remarkable manner. A ball of spongy platinum, 
placed slightly above the wick of a lamp, fed by spirit, and communicating with the wick by 
a platinum wire, when once heated, keeps at a red heat, gradually burning the spirit. This 
has been applied in the construction of the so-called " philosophical pastilles ; " eau-de- 
cologne or\other perfumed spirit being thus made to diffuse itself in a room. 

Mr. Gilfhas also practically applied this in the construction of an alcohol lamp without 

A coil of platinum wire, of about the one-hundreth part of an inch in thickness, is coiled 
partly round the cotton wick of a spirit lamp, and partly above it, and the lamp lighted to 
heat the wire to redness ; on the flame being extinguished, the alcohol vapor keeps the wire 
red hot for any length of time, so as to be in constant readiness to ignite a match, for 
example. This lamp affords sufficient light to show the hour by a watch in the night, with 
a very small consumption of spirit. 


This property of condensing oxygen, and thus causing the union of it with combustible 
bodies, is not confined to platinum, but is possessed, though in a less degree, by other 
porous bodies. If we moisten sand in a capsule with absolute alcohol, and cover it with 
previously heated nickel powder, protoxide of nickle, cobalt powder, protoxide of cobalt, 
protoxide of uranium, or oxide of tin (these six bodies being procured by ignition of their 
oxalates in a crucible), or finely powdered peroxide of manganese, combustion takes place, 
and continues so long as the spirituous vapor lasts. 

Solvent Power. — One of the properties of alcohol most valuable in the arts is its solvent 

It dissolves gases to a very considerable extent, which gases, if they do not enter into com- 
binations with the alcohol, or act chemically upon it, are expelled again on boiling the alcohol. 

Several salts, especially the deliquescent, are dissolved by it, and some of them give a 
color to its flame ; thus the solutions of the salts of strontia in alcohol burn with a crimson 
fame, those of copper and borax with a green one, lime a reddish, and baryta with a yellow 

This solvent power is, however, most remarkable in its action upon resins, ethers, essen- 
tial oils, fatty bodies, alkaloids, as well as many organic acids. In a similar way it dissolves 
iodine, bromine, and in small quantities sulphur and phosphorus. In general it may be said 
to be an excellent solvent for most hydrogenized organic substances. 

In consequence of this property it is most extensively used in the chemical arts ; e. g. for 
the solution of gum-resins, &c, in the manufacture of varnishes ; in pharmacy, for the 
separating of the active principles of plants, in the preparation of tinctures. It is also em- 
ployed in the formation of chloroform, ether, spirits of nitre, &c. 

Methylated Spirit. — It was, therefore, for a long time a great desideratum for the 
manufacturer to obtain spirit free from duty. The Government, feeling the necessity for 
this, have sanctioned the sale of spirit which has been flavored with methyl-alcohol, so as to 
render it unpalatable, free of duty under the name of " methylated spirit.'''' This methylated 
spirit can now be obtained, in large quantities only, and by giving suitable security to the 
Board of Inland Revenue of its employment for manufacturing purposes only, and must 
prove of great value to those manufacturers who are large consumers. 

Professors Graham, Hoffmann, and Redwood, in their " Report on the Supply of Spirit 
of Wine, free of duty, for use in the Arts and Manufactures," addressed to the Chairman 
of the Board of Inland Revenue, came to the following conclusions : — 

" From the results of this inquiry, it has appeared that means exist by which spirit of 
wine, produced in the usual way, may be rendered unfit for human consumption, as a 
beverage, without materially impairing it for the greater number of the more valuable pur- 
poses in the arts to which spirit is usually applied. To spirit of wine, of not less strength 
than corresponds to density 0'830, it is proposed to make an addition of 10 per cent, of 
purified wood naphtha (ivood or methylic spirit), and to issue this mixed spirit for consump- 
tion, duty free, under the name of Methylated Spirit. It has been shown that methylated 
spirit resists any process for its purification ; the removal of the substance added to the spirit 
of wine being not only difficult, but, to all appearance, impossible ; and further, that no 
danger is to be apprehended of the methylated spirit being ever compounded so as to make 
it palatable. . . It may be found safe to reduce eventually the proportion of the mixing 
ingredient to 5 per cent., or even a smaller proportion, although it has been recommended 
to begin with the larger proportion of 10 per cent." 

And further, the authors justly remark : — " The command of alcohol at a low price 
is sure to suggest a multitude of improved processes, and of novel applications, which can 
scarcely be anticipated at the present moment. It will be felt far beyond the limited range 
of the trades now more immediately concerned in the consumption of spirits ; like the 
repeal of the duty on salt, it will at once most vitally affect the chemical arts, and cannot 
fail, ultimately, to exert a beneficial influence upon many branches of industry." 

And in additional observations, added subsequently to their original report, the chem- 
ists above named recommend the following restriction upon the sale of the methylated 
spirit : — " That the methylated spirit should be issued by agents duly authorized by the 
Board of Inland Revenue, to none but manufacturers, who should themselves consume it ; 
and that application should always be made for it according to a recognized form, in which, 
besides the quantity wanted, the applicant should state the use to which it is to be applied, 
and undertake that it should be applied for that purpose only. The manufacturer might be 
permitted to retail varnishes and other products containing the methylated spirit, but not 
the methylated spirit itself, in an unaltered state." They recommend that the methylated 
spirit should not be made with the ordinary crude, very impure wood naphtha, since this 
could not be advantageously used as a solvent for resins by hatters and varnish-makers, as 
the less volatile parts of the naphtha would be retained by the resins after the spirit had 
evaporated, and the quality of the resin would be thus impaired. If, however, the methy- 
lated spirit be originally prepared with the crude wood naphtha, it may be purified by a 
simple distillation from 10 per cent, of potash. 
Vor,. TTT.— ". 


_ It appears that the boon thus afforded to the manufacturing community of obtaining 
spirit dutyfree has been acknowledged and appreciated ; and now for most purposes, where 
the small quantity of wood-spirit does not interfere, the methylated spirit is generally used. 
It appears that even ether and chloroform, which one would expect to derive an un- 
pleasant flavor from the wood-spirit, are now made of a quality quite unobjectionable from 
the methylated spirit ; but care should be taken, especially in the preparation of medicinal 
compounds, not to extend the employment of the methylated spirit beyond its justifiable 
limits, lest so useful an article should get into disrepute!* Methylated spirit can be pro- 
cured also in small quantities from the wholesale dealers, containing in solution 1 oz. to the 
gallon of shellac, under the name of " finish." 

Alcoholatcs. — Graham has shown that alcohol forms crystallizable compounds wit!: 
several salts. These bodies, which he calls " Alcoholates," are in general rather unstable 
combinations, and almost always decomposed by water. Among the best known are the 
following : — 

Alcoholate of chloride of calcium - - - 2 C 4 H 6 2 , Ca CI 

" of zinc - - - C 4 H°0 2 , Zn CI 

" bichloride of tin ... C 4 H c 2 , Tn CI 

" nitrate of magnesia - - - 3 C 4 H°0 2 , Mg 0, K0 6 

ALCOHOLOMETRY, or ALCOOMETRY. Determination of the Strength of Mixtures 
of Alcohol and Water. Since the commercial value of the alcoholic liquors, commonly 
called "spirits," is determined by the amount of pure or absolute alcohol present in them, 
it is evident that a ready and accurate means of determining this point is of the highest 
importance to all persons engaged in trade in such articles. 

If the mixture contain nothing but alcohol and water, it is only necessary to determine 
the density or specific gravity of such a mixture ; if, however, it contain saccharine matters, 
coloring principles, &c, as is the case with wine, beer, &c, other processes become neces- 
sary, which will be fully discussed hereafter. 

The determination of the specific gravity of spirit, as of most other liquids, may be 
effected, with perhaps greater accuracy than by any other process, by means of a stoppered 
specific gravity bottle. If the bottle be of such a size as exactly to hold 1,000 grains of 
distilled water at 60° F., it is only necessary to weigh it full of the spirit at the same tem- 
perature, when (the weight of the bottle being known) the specific gravity is obtained by a 
very simple calculation. See Specific Gravity. 

This process, though very accurate, is somewhat troublesome, especially to persons 
unaccustomed to accurate chemical experiments, and it involves the possession of a delicate 
balance. The necessity for this is however obviated by the employment of one of the many 
modifications of the common hydrometer. This is a floating instrument, the use of which 
depends upon the principle, that a solid body immersed into a fluid is buoyed upwards with 
a force equal to the weight of the fluid which it displaces, i. e. to its own bulk of the fluid ; 
consequently, the denser the spirituous mixture, or the less alcohol it contains, the higher 
will the instrument stand in the liquid ; and the less dense, or the more spirit it contains, 
the lower will the apparatus sink into it. 

There are two classes of hydrometers : 1st. Those which are always immersed in the 
fluid to the same depth, and to which weights are added to adjust the instrument to the 
density of any particular fluid. Of this kind are Fahrenheit's, Nicholson's, and Guyton de 
Morveau's hydrometers. 

2d. Those which are always used with the same weight, but which sink into the liquids 
to be tried, to different depths, according to the density of the fluid. Of this class are most 
of the common glass hydrometers, such as Beaume's, Curteis's, Gay-Lussac's, Twaddle's, &c. 

Sykes's and Dicas's combine both principles. See Hydrometers. 

Sykes's hydrometer, or alcoholometer, is the one employed by the Board of Excise, and 
therefore the one most extensively used in this country. 

This instrument does not immediately indicate the density or the percentage of absolute 
alcohol, but the degree above or below proof — the meaning of which has been before 
detailed ; (p. 30.) 

It consists of a spherical ball or float, a, with an upper and lower stem of brass, b and c. 
The upper stem is graduated into ten principal divisions, which are each subdivided into 
five parts. The lower stem, c, is made conical, and has a loaded bulb at its extremity. 
There are nine movable weights, numbered respectively by tens from 10 to 90. Each of 
these circular weights has a slit in it, so that it can be placed on the conical stem, c. The 
instrument is adjusted so that it floats with the surface of the fluid coincident with zero on 
the scale in a spirit of specific gravity -825 at 60° F., this being accounted by the Excise as 
" standard alcohol.' 1 '' In weaker spirit, which has therefore a greater density, the hydrom- 

* Some difference of opinion appenrs to exist whether Chloroform can be obtained pure from me- 
thylated spirit. 



eter will not sink so low ; and if the density be much greater, it will be necessary to add 
one of the weights to cause the entire immersion of the bulb of the instrument. Each 
weight represents so many principal divisions of the stem as its number 
indicates ; thus, the heaviest weight, marked 90, is equivalent to 90 
divisions of the stem, and the instrument, with the weight added, floats at 
in distilled water. As each principal division on the stem is divided 
into five subdivisions, the instrument has a range of 500 degrees be- 
tween the standard alcohol (specific gravity -825) and water. There is a 
line on one of the side faces of the stem, 6, near division 1 of the draw- 
ing, at which line the instrument with the weight 60 attached to it, floats 
in spirits exactly of the strength of proof, at a temperature of 51° F. 

In using this instrument, it is immersed in the spirit, and pressed down 
by the hand until the whole of the graduated portion of the upper stem 
is" wet. The force of the hand required to sink it will be a guide to the 
selection of the proper weight. Having taken one of the circular weights 
necessary for the purpose, it is slipped on to the lower conical stem. 

The instrument is again immersed, and pressed down as before to 0, 
and then allowed to rise and settle at any point. The eye is then brought 
to the level of the surface of the spirit, and the part of the stem cut by 
the surface as seen from below, is marked. The number thus indicated 
by the stem is added to the number of the weight, and the sum of these, 
together with the temperature of the spirit, observed at the same time by 
means of a thermometer, enables the operator, by reference to a table 
which is sold to accompany the instrument, to find the strength of the 
spirit tested. 

These tables are far too voluminous to be quoted here ; and this is 
unnecessary, since the instrument is never sold without them. 

A modification of Sykes's hydrometer has been recently adopted for 
testing alcoholic liquors, which is perhaps more convenient, as the neces- 
sity for the loading weights is done away with, the stem being sufficiently 
long not to require them. It is constructed of glass, and is in the shape 
of a common hydrometer, the stem being divided into degrees ; it 
carries a small spirit thermometer in the bulb, to which a scale is fixed, ranging from 30° to 
82° F. (0 to 12° C.) There are tables supplied with the hydrometer, which are headed by 
the degrees and half degrees of the thermometric scale ; and the corresponding content 
of spirit, over or under proof at the respective degrees of the table, is placed opposite each 
degree of the hydrometer. See Spirits, vol. ii. 

In France, Gay-Lussac's alcoolometre is usually employed. It is a common glass 
hydrometer, with the scale on the stem divided into 100 parts or degrees. The lowest 
division, marked 0, denotes the specific gravity of pure water; and 100, that of absolute 
alcohol, both at 15° C. (59° F.) The intermediate degrees, of course, show the percentage 
of absolute alcohol by volume at 15° C. ; and the instrument is accompanied by the tables 
already given for ascertaining the percentage at any other temperature. 

Alcoholometry of Liquids containing besides Alcohol, Saccharine Matters, Coloring 
Principles, Src, such as Wines, Beer, Liqueurs, Sfc. 

In order to determine the proportion of absolute alcohol contained in wines or other 
mixtures of alcohol and water with saccharine and other non-volatile substances, the most 
accurate method consists in submitting a known volume of the liquid to distillation, (in a 
glass retort, for instance ;) then, by determining the specific gravity of the distilled product, 
to ascertain the percentage of alcohol in this distillate, which may be regarded as essentially 
a mixture of pure alcohol and water. The distillation is carried on until the last portions 
have the gravity of distilled water ; by then ascertaining the total volume of the distillate, 
and with the knowledge of its percentage of alcohol and the volume of the original liquor 
used, the method of calculating the quantity of alcohol present in the wine, or other liquor, 
is sufficiently obvious. 

In carrying out these distillations, care must be taken to prevent the evaporation of the 
spirit from the distillate, by keeping the condenser cool. And Professor Mulder recom- 
mends the use of a refrigerator, consisting of a glass tube fixed in the centre of a jar, so 
that it may be kept filled with cold water. The tube must be bent at a right angle, and 
terminate in a cylindrical graduated measure-glass, shaped like a bottle.* 

It is well to continue the distillation until about two-thirds of the liquid has passed 

This process, though the most accurate for the estimation of the strength of alcoholic 

* The Chemistry of "Wine, by G. J. Mulder, edited by II. Beuce Jones, M. D. 



liquors, is still liable to error. The volatile aeids and ethers pas3 over with the alcohol into 
the distillate, and, to a slight extent, affect the specific gravity. This error may be, to a 
great extent, overcome by mixing a little chalk with the wine, or other liquor, previous to 

By this method Professor Brande made, some years ago, determinations of the strength 
of the following wines, and other liquors * ; — 

Proportion of Spirit per Cent, by Measure, 

Lissa - 







Raisin - 










Port (of 7 samples) 





5-21 to i 







Sherry (of 4 samples) 









Ale, Burton 1 

( 8-88 

Lisbon - 



Ale, Edinburgh v 



1 6 ' 20 

Malaga - 



Ale, Dorchester ) 

f 5-55 




Brown Stout 




Cape Madeira 



London Porter - 







London Small Beer 





Claret - 



















Hock - 








Tent - 



Scotch Whiskey 





Champagne - 



Irish Whiskey - 





Gooseberry - 



The following results were obtained by 

the writer more rece 

ntly by 

this process, 


Percentage of Alcohol by Volume. 

Port (1834) - 



Port (best) 





Sherry (Montilla) 











Champagne (1st) 





Claret (Haut Brion) 



Champagne (2d) 








Home Ale 





Sherry (low quality) 



Export Ale 





Sherry (brown) 



Strong Ale 
















Porter - 





M. l'Abbe Brossard-Vidal, of Toulonf, has proposed to estimate the strength of alcoholic 
liquors by determining their boiling point. Since water boils at 100° C. (212° F.), and 
absolute alcohol at 78-4° (173° F.), it is evident that a mixture of water and alcohol will 
have a higher boiling point the larger the quantity of water present in it. This method is 
even applicable to mixtures containing other bodies in solution besides spirit and water, 
since it has been shown that sugar and salts, when present, (in moderate quantities,) have 
only a very trifling effect in raising the boiling point ; and the process has the great advan- 
tage of facility and rapidity of execution, though, of course, not comparable to the method 
by distillation, for accuracy. 

Mr. Field's patent (1847) alcoholometer is likewise founded upon the same principle. 
The instrument was subsequently improved by Dr. Ure. 

The apparatus consists simply of a spirit-lamp placed under a little boiler containing the 
alcoholic liquor, into which fits a thermometer of very fine bore. 

When the liquor is stronger than proof-spirit, the variation in the boiling point is so 
small that an accurate result cannot possibly be obtained ; and, in fact, spirit approaching 
this strength should be diluted with an equal volume of water before submitting it to ebulli- 
tion, and then the result doubled. 

Another source of error is the elevation of the boiling point, when the liquor is kept 
heated for any length of time ; it is, however, nearly obviated by the addition of common 
salt to the solution in the boiler of the apparatus, in the proportion of 35 or 40 grains. In 
order to correct the difference arising from higher or lower pressure of the atmosphere, the 
scale on which the thermometric and other divisions are marked is made movable up and 

Brando's Manual of Chemistry ; also Philosophical Trans., 1S11. t Comptes Eendus, xsvii. 3T4. 



down the thermometer tube ; and every time, before commencing a set of experiments, a 
preliminary experiment is made of boiling some pure distilled water in the apparatus, and 
the zero point on the scale (which indicates the boiling point of water) is adjusted at the 
level of the surface of the mercury. 

But even when performed with the utmost care, this process is still liable to very 
considerable errors, for it is extremely difficult to observe the boiling point to within a 
decree ; and after all, the fixed ingredients present undoubtedly do seriously raise the boil- 
in^ point of the mixture — in fact, to the extent of from half to a whole degree, according to 
the amount present.. 

Silbermann's Method. — H. Silbermann* has proposed another method of estimating the 
strength of alcoholic liquors, based upon their expansion by heat. It is well known that, 
between zero and 100° C. (212° F.), the dilatation of alcohol is triple that 
of water, and this difference of expansion is even greater between 25° C. 8 

(77° F.) and 50° C. (122° F.) ; it is evident, therefore, that the expansion 
between these two temperatures becomes a measure of the amount of al- 
cohol present in any mixture. The presence of salts and organic sub- 
stances, such as sugar, coloring, and extractive matters, in solution or 
suspension in the liquid, is said not materially to affect the accuracy of 
the result ; and M. Silbermann has devised an apparatus for applying this 
principle, in a ready and expeditious manner, to the estimation of the 
strength of alcoholic liquors. The instrument may be obtained of the 
philosophical instrument-makers of London and of Liverpool. 

It consists of a brass plate, on which are fixed — 1st, An ordinary mer- 
curial thermometer graduated from 22° to 50° 0. (11° to 122° F.), these 
being the working temperatures of the dilat.atomeicr ; and 2dly, the 
dilatatometer itself, which consists of a glass pipette, open at both ends, 
and of the shape shown in the figure. A valve of cork or india-rubber 
closes the tapering end, a, which valve is attached to a rod, b b, fastened 
to the supporting plate, and connected with a spring, n, by which the 
lower orifice of the pipette can be opened or closed at will. The pipette 
is filled, exactly up to the zero point, with the mixture to be examined — 
this being accomplished by the aid of a piston working tightly in the long 
and wide limb of the pipette ; the action of which serves also another 
valuable purpose, viz., that of drawing any bubbles of air out of the 
liquid. By now observing the dilatation of the column of liquid when the 
temperature of the whole apparatus is raised, by immersion in a water-bath, 
from 25° to 50°, the coefficient of expansion of the liquid is obtained, 
and hence the proportion of alcohol — the instrument being, in fact, so 
graduated, by experiments previously made upon mixtures of known 
composition, as to give at once the percentage of alcohol. 

Another alcoholometer, which, like the former, is more remarkable for 
the great facility and expedition with which approximative results can be 
obtained than for a high degree of accuracy, was invented by M. Geisler, 
of Bonn, and depends upon the measurement of the tension of the vapor of the liquid, as 
indicated by the height to which it raises a column of mercury. 

Geisler's Alcoholometer. — It consists of a closed vessel in which the alco- 9 
holic mixture is raised to the boiling point, and the tension of the vapor ob- 
served by the depression of a column of mercury in one limb of a tube, the 
indication being rendered more manifest by the elevation of the other end of the 

The wine or other liquor of which it is desired to ascertain the strength, is put 
into the little flask, f, which, when completely filled, is screwed on to the glass 
which contains mercury, and is closed by a stopcock at s. The entire apparatus, 
which at present is an inverted position, is now stood erect, the flask and lower 
extremity of the tube being immersed in a water-bath. The vinous liquid is thus 
heated to a boiling point, and its vapor forces the mercury up into the long limb 
of the tube. The instrument having been graduated, once for all, by actual ex- 
periment, the percentage of alcohol is read off at once on the stem by the height 
to which the mercurial column rises. f 

To show how nearly the results obtained by this instrument agree with those 
obtained by the distillation process, comparative experiments were made on the s 
same wines by Dr. Bence Jones, f 

* Comptes Rendus, xxvii. 418. 

t On the Acidity, Sweetness, and Strength of different Wines, by II. Bence Jones, M. D., F. It. S., 
Proceedings of the Royal Institution, February, 1854. 


By Distillation (Mr. Witt) By Alcoholometer 
per cent, by measure, per cent, by measure. 

Port, 1834, ..... 22-46 . . i H'% 

Sherry, Montilla, .... 19-95 . . -j 20-6 

Madeira, ..... 22-40 . . 4 23-a 

Haut Brion claret, .... 10-0 . . \]].\ 

Chambertin, . . . . 11-7 . . 

Low-quality sherry, .... 20-7 

Brown sherry, ..... 23 - l 
Amontillado, . . . . 20-5- . 

Mansanilla, ..... 14-4 

( iO'4 

Port, best, 20-2 . . j *JJ 

Marcobrunner, . . . . 8 - 3 . . ■] 1. 

Home ale, . . . . . 6-4 . . j £° 

Export ale, . . . . . W . . j ^ 

Strong ale, 2-0 .. j }JJ 

Tabariffs Method. — There is another method of determining the alcoholic contents of 
mixtures, which especially recommends itself on account of its simplicity. The specific 
gravity of the liquor is first determined, half its volume is next evaporated in the open air, 
sufficient water is then added to the remainder to restore its original volume, and the spe- 
cific gravity again ascertained. By deducting the specific gravity before the expulsion of 
the alcohol from that obtained afterwards, the difference gives a specific gravity indicating 
the percentage of alcohol, which may be found by referring to Gay-Lussac's or one of the 
other Tables. Tabarie has constructed a peculiar instrument for determining these specific 
gravities, which he calls an cenometer ; but they may be performed either by a specific- 
gravity bottle or by a hydrometer in the usual way. 

Of course this method cannot be absolutely accurate ; nevertheless, Prof. Mulder's ex- 
perience with it has led him to prefer it to any of the methods before described, especially 
where a large number of samples have to be examined. He states that the results are 
almost as accurate as those obtained by distillation. The evaporation of the solution may 
be accelerated by conducting hot steam through it. 

Adulterations. — Absolute alcohol should be entirely free from water. This may be 
recognized by digesting the spirit with pure anhydrous sulphate of copper. If the spirit 
contain any water, the white salt becomes tinged blue, from the formation of the blue 
hydrated sulphate of copper. 

Rectified spirit, proof spirit, and the other mixtures of pure alcohol and water, should 
be colorless, free from odor and taste. If containing methylic or amylie alcohols, they are 
immediately recognized by one or other of these simple tests. 

Dr. Ure states, that if wood spirit be contained in alcohol, it may be detected to the 
greatest minuteness by the test of caustic potash, a little of which, in powder, causing wood 
spirit to become speedily yellow and brown, while it gives no tint to alcohol. Thus 1 per 
cent, of wood spirit may be discovered in any sample of spirits of wine. 

The admixture with a larger proportion than the due amount of water is of course de- 
termined by estimating the percentage of absolute alcohol by one or other of the several 
methods just described in detail. 

The adulterations and sophistications to which the various spirits known as rum, brandy 
whiskey, gin, &c, are subjected, will be best described under these respective heads, since 
these liquors are themselves mixtures of alcohol and water with sugar, coloring matters, 
flavoring ethers, &c. 

ALDEHYDE. By this word is understood the fluid obtained from alcohol by the 
removal of two equivalents of hydrogen. Thus, alcohol being represented by the formula 
D 4 H 6 0", aldehyde becomes C 4 H 4 0\ 

ALDER. 39 

Preparation. — Aldehyde is prepared by various processes of oxidation. Liebig has 
published several methods, of which the following is perhaps the best : Three parts of 
peroxide of manganese, three of sulphuric acid, two of water, and two of alcohol of 80 per 
cent., are well mixed and carefully distilled in a spacious retort. The extreme volatility of 
aldehyde renders good condensation absolutely necessary. The contents of the retort are 
to be "distilled over a gentle and manageable fire until frothing commences, or the distillate 
becomes acid. This generally takes place when about one-third has passed over. The fluid 
in the receiver is to have about its own weight of chloride of calcium added, and, after 
slight digestion, is to be carefully distilled on the water-bath. The distillate is again to be 
treated in the same way. By these processes a fluid will be obtained entirely free from 
water, but containing several impurities. To obtain the aldehyde in a state of purity, it is 
necessary, in the first place, to obtain aldehyde-ammonia ; this may be accomplished in the 
follewing manner : — The last distillate is to be mixed in a flask with twice its volume of 
ether, and, the flask being placed in a vessel surrounded by a freezing mixture, dry ammo- 
niacal gas is passed in until the fluid is saturated. In a short time crystals of the com- 
pounds sought separate in considerable quantity. The aldehyde-ammonia, being collected 
on a filter, or in the neck of a funnel, is to be washed with ether, and dried by pressure 
between folds of filtering paper, followed by exposure to the air. It now becomes neces- 
sary to obtain the pure aldehyde from the compound with ammonia. For this purpose two 
parts are to be dissolved in an equal quantity of water, and three parts of sulphuric acid, 
mixed with four of water, are to be added. The whole is to be distilled on the water-bath, 
the temperature, at first, being very low, and the operation being s opped as soon as the 
water boils. The distillate is to be placed in a retort connected with a good condensing 
apparatus, and, as soon as all the joints are known to be tight, chloride of calcium, in frag- 
ments, is to be added. The heat arising from the hydration of the chloride causes the dis- 
tillation to commence, but it is carried on by a water-bath. The distillate, after one more 
rectification over chloride of calcium, at a temperature not exceeding 80° F., will consist 
of pure aldehyde. Aldehyde is a colorless, very volatile, and mobile fluid, having the den- 
sity 0'800 at 32°. It boils, under ordinary atmospheric pressure, at '10" F. Its vapor 
density is 1'532. Its formula corresponds to four volumes of vapor ; we consequently 
obtain the theoretical vapor density by multiplying its atomic weight = 44 by half the 
density of hydrogen, or .0346. The number thus found is 1-5224, corresponding as nearly 
as could be desired to the experimental result. 

Aldehyde is produced in a great number of processes, particularly during the destructive 
distillation of various organic matters, and in processes of oxidation. From alcohol, alde- 
hyde may be procured by oxidation with platinum black, nitric acid, chromic acid, chlorine 
(in presence of water), or, as we have seen, a mixture of peroxide of manganese and sul- 
phuric acid. Certain oils, by destructive distillation, yield it. Wood vinegar in the crude 
state contains aldehyde as well as wood spirit. Lactic acid, when in a combination with 
weak bases, yields it on destructive distillation. Various animal and vegetable products 
afford aldehyde by distillation with oxidizing agents, such as sulphuric acid and peroxide of 
manganese, or bichromate of potash. 

The word aldehyde, like that of alcohol, is gradually becoming used in a much more 
extended sense than it was formerly. By the term is now understood any organic sub- 
stance which, by assimilating two equivalents of hydrogen, yields a substance having the 
properties of an alcohol, or, by taking up two equivalents of oxygen, yields an acid. It is 
this latter property which has induced certain chemists to say that there is the same relation 
between an aldehyde and its acid as between inorganic acids ending in ous and ic. Several 
very interesting and important substances are now known to belong to the class of alde- 
hydes. The essential oils are, in several instances, composed principally of bodies having 
the properties of aldehydes. Among the most prominent may be mentioned the oils of 
bitter almonds, cumin, cinnamon, rue, &c. An exceedingly important character of the 
aldehydes is their strong tendency to combine with the bisulphites of ammonia, potash, and 
soda. By availing ourselves of this property, it becomes easy to separate bodies of this 
class from complex mixtures, and, consequently, enable a proximate analysis to be made. 
Now that the character of the aldehydes is becoming better understood, the chances of arti- 
ficially producing the essential oils above alluded to in the commercial scale become greatly 
increased. Several have already been formed, and, although in very small quantities, the 
success has been sufficient to warrant sanguine hopes of success. A substitute for one of 
them has been for some years known under the very incorrect name of artificial oil of bitter 
almonds. See Nitrobenzole. — C. G. W. 

ALDER. (Aune, Fr. ; Eric, Germ. ; Alnux glutinosa, Lin.) A tree, different species 
of which are indigenous to Europe, Asia, and America. The common alder seldom grows 
to a height of more than 40 feet. The wood is stated to be very durable under water. 
The piles at Venice, and those of Old London Bridge, are stated to have been of aider ; 
and it is much used for pipes, pumps, and sluices. The charcoal of this wood is used for 




ALEMBIC, a still {which see). The term is, however, applied to a still of peculiar con- 
struction, in which the head, or capital, is a separate piece, 
fitted and ground to the neck of the boiler, or cucurbit, or 
otherwise carefully united with a lute. The alembic has this 
advantage over the common retort, that the residue of distilla- 
tion may be easily cleared out of the body. It is likewise 
capable, when skilfully managed, of distilling a much larger 
quantity of liquor in a given time than a retort of equal ca] - 
city. In France the term alembic, or rather alambic. is listi. 
to designate a glass still. 

ALGAROTH, POWDER OF. Powder of Algarotti,— 
English Powder. This salt was discovered by Algarotti, a 
physician of Verona. Chloride of antimony is formed by 
boiling black sulphide of antimony with hydrochloric acid : on 
pouring the solution into water, a white flocky precipitate falls, 
which is an oxichloride of antimony. If the water be hot, 
the precipitate is distinctly crystalline ; this is the powder of 
algaroth. This oxichloride is used to furnish oxide of antimony in the preparation of tartar 

ALGiE. (Varech, Fr. ; Seegras, or Alge, Germ.) A tribe of subaqueous plants, in- 
cluding the seaweeds (focus) and the lavers {ulva) growing in salt water, and the fresh 
water confervas. We have only to deal with those seaweeds which are of any commercial 
value. These belong to the great division of the jointless algw, of which 160 species are 
known as natives of the British Isles. In the manufacture of Kelp, (see Kelp,) all the varie- 
ties of this division may be used. The edible sorts, such as the birds' nests of the Eastern 
Archipelago, those which we consume in this country, as layers, carrageen, or Irish moss, 
&c, belong to the same group, as do also those which the agriculturalists employ for manure. 
Dr. Pereira gives the following list of esculent seaweeds : — 

Phodomenia palmata (or Dulse). 
Phodomenia ciliata. 
Lami.naria saccharina. 

Iridcea edulis. 
Alaria escidenta. 
Ulva latissima. 

Phodomenia palmata passes under a variety of names, dulse, dylish, or dellish, and 
amongst the Highlanders it is called dulling, or waterleaf. It is employed as food by the 
poor of many nations ; when well washed, it is chewed by the peasantry of Ireland without 
being dressed. It is nutritious, but sudorific, has the smell of violets, imparts a mucila- 
ginous feel to the mouth, leaving a slightly acrid taste. In Iceland the dulse is thoroughly 
washed in fresh water and dried in the air. AVhen thus treated it becomes covered with a 
white powdery substance, which is sweet and palatable ; this is mannite, (see Manna,) which 
Dr. Stenhouse proposes to obtain from seaweeds. " In the dried state it is used in Iceland 
with fish and butter, or else, by the higher classes : boiled in milk with the addition of rye 
flour. It is preserved packed in close casks ; a fermented liquor is produced in Kam- 
schatka from this seaweed, and in the north of Europe and in the Grecian Archipelago 
cattle are fed upon it." — Stenhouse. 

Laminaria saccharina yields 12-15 percent, of mannite, wdiile the Phodomenia pal- 
mata contains not more than 2 or 3 per cent. 

Iridcea echdis. — The fronds of this weed are of a dull purple color, flat, and succulent. 
It is employed as food by fishermen, either raw or pinched between hot irons, and its taste 
is then said to resemble roasted oysters. 

Alaria escidenta. — Mr. Drummond informs us that, on the coast of Antrim, " it is often 
gathered for eating, but the part used is the leaflets, and not the midrib, as is commonly 
stated. These have a very pleasant taste and flavor, but soon cover the mouth with a tena- 
cious greenish crust, which causes a sensation somewhat like that of the fat of a heart or 

Ulva latissima, (Broad green laver.) — This is rarely used, being considered inferior to 
the Porphyra laciniata, (Laciniated purple laver.) This alga is abundant on all our shores. 
It is pickled with salt, and sold in England as laver, in Ireland as slojce, and in Scotland as 
slaak. The London shops are mostly supplied with laver from the coasts of Devonshire. 
When stewed, it is brought to the table and eaten with pepper, butter or oil, and lemon- 
juice or vinegar. Some persons stew it with leeks and onions. The pepper dulse, (Lau- 
rencia pinnatifida,) distinguished for its pungent taste, is often used as a condiment when 
other seaweeds are eaten. " Tangle," (Lami.naria digitata,) so called in Scotland, is 
termed " red-ware " in the Orkneys, " sea-wand " in the Highlands, and " sea-girdles " in 
England. The flat leathery fronds of this weed, when young, are employed as food, Mr. 
Simmonds tells us, " There was a time when the cry of ' Buy dulse and tangle ' was as com- 
mon in the streets of Edinburgh and Glasgow, as is that of ' water-cresses' now in our me- 
tropolis." — Society of Arts' Journal. 


Laminaria potatorum. — The large sea tangle is used abundantly by the inhabitants of 
the Straits of Magellan and by the Fuegians. Under the name of " Bull Kelp " it is used 
as food in New Zealand and Van Diemen's Land. It is stated to be exceedingly nutritive 
and fattening. 

Chondrus crispus, (chondrus, from x^ySpos, cartilage.) — Carrageen, Irish, or pearl moss. 
For purposes of diet and for medicinal uses, this alga is collected on the west coast of Ire- 
land, washed, bleached by exposure to the sun, and dried. It is not unfrequently used in 
Ireland by painters and plasterers as a substitute for size. It has also been successfully 
applied, instead of isinglass, in making of blanc-mange and jellies ; and in addition to its 
use in medicine, for which purpose it was introduced by Dr. Todhunter, of Dublin, about 
1S31, a thick mucilage of carrageen, scented with some prepared spirit, is sold as bando- 
line, fixature, or clysphitique, and it is employed for stiffening silks. According to Dr. 
Davy, carrageen consists of 

Gummy matter, . . . . . 28 -5 

Gelatinous matter, . . . . . 49-0 

Insoluble matter, ...... 22-5 


Plocaria Candida. — Ceylon moss ; edible moss. This moss is exported from the islands 
of the Indian Archipelago, forming a portion of the cargoes of nearly all the junks. It is 
stated by Mr. Crawford, in his " History of the Indian Archipelago," that on the spots where 
it is collected, the prices seldom exceed from 5s. 8d. to *7s. 6<£ per cwt. The Chinese use 
it in the form of a jelly with sugar, as a sweetmeat, and apply it in the arts as an excel- 
lent paste. The gummy matter which they employ for covering lanterns, varnishing paper, 
&c, is made chiefly from this moss. 

This moss, as ordinarily sold, appears to consist of several varieties of marine produc- 
tions, with the Plocaria intermixed. 

The Agar-Agar of Malacca belongs to this variety ; and probably seaweeds of this 
character are used by the Salangana or esculent swallow in constructing their nests, which 
are esteemed so great a delicacy by the Chinese. The plant is found on the rocks of Pulo 
Ticoos and on the shores of the neighboring islands. It is blanched in the sun for two 
days, or until it is quite white. It is obtained on submerged banks in the neighborhood of 
Macassar, Celebes, by the Bajow-laut, or sea-gipsies, who send it to China. It is also col- 
lected on the reefs and rocky submerged ledges in the neighborhood of Singapore. Mr. 
Montgomery Martin informs us that this weed is the chief staple of Singapore, and that it 
produces in China from six to eight dollars per pecul in its dry and bulky state. The har- 
vest of this seaweed is from 6,000 to 12,000 peculs annually, the pecul being equal to 100 
catties of 1-333 lbs. each. 

Similar to this, perhaps the same in character, is the Agal-Agal, a species of seaweed. 
It dissolves into a glutinous substance. Its principal use is for gumming silks and paper, as 
nothing equals it for paste, and it is not liable to be eaten by insects. The Chinese make a 
beautiful kind of lantern, formed of netted thread washed over with this gum, and which is 
extremely light and transparent. It is brought by coasting vessels to Prince of Wales 
Island, and calculated for the Chinese market. — Oriental Commerce. 

ALIMENT. (Alimentum, from alo, to feed.) The food necessary for the human body, 
and capable of maintaining it in a state of health. 

1. Nitrogenous substances are required to deposit, from the blood, the organized tissue 
and solid muscle ; 

2. And carbonaceous, non-nitrogenous bodies, to aid in the processes of respiration, and 
in the supply of carbonaceous elements, as fat, &c., for the due support of animal heat. 

For information on these substances, consult Liebig's " Animal Chemistry," the investi- 
gations of Dr. Lyon Playfair, and Dr. Eobert Dundas Thompson's " Experimental Researches 
oaFood," 1846. 

ALKALI. A term derived from the Arabians, and introduced into Europe when the 
Mahometan conquerors pushed their conquests westward. Al, el, or ul, as an Arabic 
noun, denotes " God, Heaven, Divine." As an Arabic particle, it is prefixed to words to 
give them a more emphatic signification, much the same as our particle the ; as in Alcoran, 
the Koran ; alehymisi, the chemist. 

Kali was the old name for the plant producing potash, (the glasswort, so called from its 
use in the manufacture of glass,) and alkali signified no more than the kali plant. Potash and 
soda were for some time confounded together, and were hence called alkalis. Ammonia, 
which much resembles them when dissolved in water, was also called an alkali. Ammonia 
was subsequently distinguished as the volatile alkali, potash and soda being fixed alkalis: 
Ammonia was also called the animal alkali. Soda was the mineral alkali, being derived 
from rock salt, or from the ocean ; and potash received the name of vegetable alkali, from 
its source being the ashes of plants growing upon the land. Alkalis are characterized by 



being very soluble in water, by neutralizing the strongest acids, by turning brown vegetable 
yellows, and to green the vegetable reds and blues. 

Some chemists classify all salifiable bases under this name. 

In commercial language, the term is applied to an impure soda, the imports of which 
were — 


Alkali and Barilla. 







Canary Islands .... 


Two Sicilies 

Egypt --.--- 


Other parts 

Total .... 


















21,200 i 

Our Exports during the same periods being as follows : — 

Alkali and Barilla. 









Kussia — Northern Ports 





" Southern Ports 








Denmark . - - - - 





Prussia ------ 










Ha rise Towns .... 




83,385 ■ 






Belgium ...... 






Spain and the Canaries - - - 






Austrian Territories ... 















British North America - 





United States .... 





Brazil ------ 








Other Countries - 

Total .--- 









ALKALIS, ORGANIC. During the last few years the number of organic alkaloids has 
so greatly increased, that a considerable volume might be devoted to their history. There 
are, however, only a few which have become articles of commerce. The modes of prepa- 
ration will be given under the heads of the alkalis themselves. The principal sources from 
whence they are obtained are the following :■ — 1. The animal kingdom. 2. The vegetable 
kingdom. 3. Destructive distillation. 4. The action of potash on the cyanic and cyanuric 
ethers. 5. The action of ammonia on the iodides, &e., of the alcohol radicals. 6. The 
action of reducing agents on nitro-compounds. The principal bases existing in the animal 
kingdom are creatine and sarcosine. The vegetable kingdom is much richer in them, and 
yields a great number of organic alkalis, of which several are of extreme value in medi- 
cine. Modern chemists regard all organic alkalis as derived from the types ammonia or 
oxide of ammonium. Their study has led to results of the most startling character. It has 
been found that not only may "the hydrogen in ammonia and oxide of ammonium be 
replaced by metals and compound radicals without destruction of the alkaline character, but 
even the nitrogen may be replaced by phosphorus or arsenic, and yet the resulting com- 
pounds remain powerfully basic. In studying the organic bases, chemists have constantly 



had in view the artificial production of the bases of cinchona bark. It is true that this 
result has not as yet been attained ; but, on the other hand, bodies have been formed hav- 
ing so many analogies, both in constitution and properties, with the substances sought, that 
it cannot be doubted the question is merely one of time. The part performed by the bases 
existing in the juice of flesh has not been ascertained, and no special remedial virtues have 
been detected in them ; but this is not the case with those found in vegetables ; it is, in 
fact, among them that the most potent of all medicines are found — such, for example, as 
quinine and morphia. It is, moreover, among vegetable alkaloids that we find the sub- 
stances most inimical to life, for aconitine, atropine, brucine, coniine, curarine, nicotine, 
solanine, strychnine, &c, &c, are among their number. It must not be forgotten, how- 
ever, that, used with proper precaution, even the most virulent are valuable medicines. 
The fearfully poisonous nature of some of the organic bases, together with an idea that they 
are difficult to detect, has unhappily led to their use by the poisoner ; strychnine, especially, 
has acquired a painful notoriety, in consequence of its employment by a medical man to 
destroy persons whose lives he had insured. Fortunately for society, the skill of the 
analyst has more than kept pace with that of the poisoner ; and without regarding the 
extravagant assertions made by some chemists as to the minute quantities of vegetable 
poisons they are able to detect, it may safely be asserted that it would be very difficult to 
administer a fatal dose of any ordinary vegetable poison without its being discovered. 
Another check upon the poisoner is found in the fact that those most difficult of isolation 
from complex mixtures are those which cause such distinct symptoms of poisoning in the 
victim, that the medical attendant, if moderately observant, can scarcely fail to have his 
suspicions aroused. 

Under the heads of the various alkaloids will be found (where deemed of sufficient 
importance) not merely the mode of preparation, but also the easiest method of detection. 
— C. G. W. 

ALKALIHETER. There are various kinds of alkalimeters, but it will be more conven- 
ient to explain their construction and use in the article on Alkalimetry, to which the 
reader is referred. 

ALKALIMETRY. 1. The object of alkalimetry is to determine the quantity of caustic 
alkali or of carbonate of alkali contained in the potash or soda of commerce. The prin- 
ciple of the method is, as in acidimetry, based upon Dalton's law of chemical combining 
ratios — that is, on the fact that in order to produce a complete reaction, a certain definite 
weight of reagent is required, or, in other words, in order to saturate or completely neu- 
tralize, for example, one equivalent of a base, exactly one equivalent of acid must be em- 
ployed, and vice versa. This having been thoroughly explained in the article on Acidim- 
etry, the reader is referred thereto. 

2. The composition of the potash and of the soda met with in commerce presents very 


great variations ; and the value of these substances being, of course, in propor- 
tion to the quantity of real alkali which they contain, an easy and rapid method 
of determining that quantity is obviously of the greatest importance both to the 
manufacturer and to the buyer. The process by which this object is attained, 
though originally contrived exclusively for the determination of the intrinsic 
value of these two alkalis, (whence its name, Alkalimetry,) has since been ex- 
tended to that of ammonia and of earthy bases and their carbonates, as will be 
shown presently. 

3. Before, however, entering into a description of the process itself, we will 
give that of the instrument employed in this method of analysis, which instru- 
ment is called an alkalimeter. 

4. The common alkalimeter is a tube closed at one end, (see figure in mar- 
gin,) of about f of an inch internal diameter, about 9A inches long, and is 
thus capable of containing 1,000 grains of pure distilled water. The space 
occupied by the water is divided accurately into 100 divisions, numbering from 
above downwards, each of which, therefore, represents 10 grains of distilled 

5. When this alkalimeter is used, the operator must carefully pour the acid 
from it by closing the tube with his thumb, so as to allow the acid to trickle in 
drops as occasion may require ; and it is well also to smear the edge of the tube 
with tallow, in order to prevent any portion of the test acid from being wasted 
by running over the outside after pouring, which accident would, of course, 
render the analysis altogether inaccurate and worthless ; and, for the same rea- 
son, after having once begun to pour the acid from the alkalimeter by allowing 
it to trickle between the thumb and the edge of the tube, as above mentioned, 
the thumb must not be removed from the tube till the end of the experiment, 
for otherwise the portion of acid which adheres to it would, of course, be wasted 
and vitiate the result. This uncomfortable precaution is obviated in the other forms of 
alkalimeter now to be described. 













































f 3 ? 

6. That represented in fig. 12 is Gay-Lussac's alkalimeter ; it is a glass tube about 14 
inches high, and \ an inch in diameter, capable of holding more than 1,000 grains of dis- 
tilled water ; it is accurately graduated from the top down- 
wards into 100 divisions, in such a way that each division 
may contain exactly 10 grains of water. It has a small tube, 
6, communicating with a larger one, which small tube is bent 
and bevelled at the top, c. This very ingenious instrument, 
known also under the name of " burette" and " pouretfi was 
contrived by Gay-Lussac, and is by far more convenient than 
the common alkalimeter, as by it the test acid can be unerringly 
poured, drop by drop, as wanted. The only drawback is the 
fragility of the small side-tube, 6, on which account the com- 
mon alkalimeter, represented in fig. 11 is now generally used, 
especially by workmen, because, as it has no side-tube, it is 
less liable to be broken ; but it gives less accurate results, a 
portion of the acid being wasted in various ways, and it is, 
besides, less manageable. Gay-Lussac's " burette " is there- 
fore preferable ; and if melted wax be run between the space 
of the large and of the small tube, the instrument is rendered 
much less liable to injury ; it is generally sold with a separate 
wooden foot or socket, in which it may stand vertically. 

7. The following form of alkalimeter, {fig. 13,) which I 
contrived several years ago, will, I think, be found equally 
delicate but more convenient still than that of Gay-Lussac. It 
consists of a glass tube, a, of the same dimensions, and grad- 
uated in the same manner as that of Gay-Lussac ; but it is 
provided with a glass foot, and the upper part, b, is shaped 
like the neck of an ordinary glass bottle ; c is a bulb blown from a glass tube, one end of 
winch is ground to fit the neck, b, of the alkalimeter, like an ordinary glass stopper. This 
bulb is drawn to a capillary point at d, and has a somewhat large opening at e. With this 
instrument the acid is perfectly under the control of the operator, for the globular joint at 
the top enables him to see the liquor before it actually begins to drop out, and he can then 
regulate the pouring to the greatest nicety, whilst its more substantial form renders it much 
less liable to accidents than that of Gay-Lussac ; the glass foot is extremely convenient, and 
is at the same time a great additional security. The manner of using it will be described 
further on. 

8. Another alkalimeter of the same form as that which I have just described, except that 
it is all in one piece, and has no globular enlargement, is represented in fig. 14. Its con- 
struction is otherwise the same, and the results obtained are equally 

delicate ; but it is less under perfect control, and the test acid is very 
liable to rim down the tube outside : this defect might be easily 
remedied by drawing the tube into a finer and more delicate point, 
instead of in a thick, blunted projection, from which the last drop 
cannot be detached, or only with difficulty, and imperfectly. A glass 
foot would, moreover, be an improvement. 

9. With Schuster's alkalimeter, (represented in fig. 15,) the strength 
of alkalis is determined by the weight, not by the measure, of the acid 
employed to neutralize the alkali ; it is, as may be seen, a small bottle 
of thin glass, having the form of the head of the alkalimeter repre- 
sented in fig. 13. We shall describe further on the process of analysis 
with this alkalimeter. 

10. There are several other forms of alkalimeter, but those which 
have been alluded to are almost exclusively used, 
and whichever of them is employed, the process is 
the same — namely, pouring carefully an acid of a 
known strength into a known weight of the alkali 
under examination, until the neutralizing point is 
obtained, as will be fully explained presently. 

11. Blue litmus-paper being immediately red- 
dened by acids is the reagent used for ascertaining 
the exact point of the neutralization of the alkali 
to be tested. It is prepared by pulverizing one part 
of commercial litmus, and digesting it in six parts 
of cold water, filtering, and dividing the blue liquid 
into two equal portions, adding carefully to one of the portions, and one drop at a time, as 
much very dilute sulphuric acid as is sufficient to impart to it a slight red color, and pouring 
the portion so treated into the second portion, which is intensely blue, and stirring the 


\ r 

























whole together. The mixture so obtained is neutral, and by immersing slips of white blot- 
ting-paper into it, and carefully drying them by hanging them on a stretched piece of 
thread, an exceedingly sensitive test paper of a light blue color is obtained, which should be 
kept in a wide-mouth glass-stoppered bottle, and sheltered from the air and light. 

12. Since the principle on which alkalimetry is based consists in determining the amount 
of acid which a known weight of alkali can saturate or neutralize, it is clear that any acid 
having this power can be employed. 

13. The test acid, however, generally preferred for the purpose is sulphuric acid, because 
the normal solution- of that acid is more easily prepared, is less liable to change its strength 
by keeping, and h is a stronger ' reaction on litmus-paper than any other acid. It is true 
that other acids — tartaric acid, for example — can be procured of greater purity, and that, as 
it is dry and not caustic, the quantities required can be more comfortably and accurately 
weighed off; and on this account some chemists, after Buchner, recommended its use, but 
the facility with which its aqueous solution becomes mouldy is so serious a drawback, that it 
is hardly ever resorted to for that object. 

14. AVhen sulphuric acid is employed, the pure acid in the maximum state of concen- 
tration, or, as it is called by chemists, the pure hydrate of sulphuric acid, specific gravity 
1-8485, is preferable. Such an acid, however, is never met with in commerce, for the 
ordinary English oil of vitriol is seldom pure, and never to the maximum state of concen- 
tration ; the operator, however, may prepare it by distilling ordinary oil of vitriol, but as 
the specific caloric of the vapor of sulphuric acid is very small, the distillation is a some- 
what hazardous operation, unless peculiar precaution be taken. The following apparatus, 
however, allows of the acid being distilled in a perfectly safe and convenient manner ; it 
consists of a plain glass retort, charged with oil of vitriol, a little protosulphate of iron is 
added, for the purpose of destroying any nitrous products which the acid may evolve, and 
it is then placed into a cylinder of iron, the bottom of which is perforated with holes about 
three-quarters of an inch in diameter, except in the middle, where a large hole is cut of a 
suitable size for the retort to rest upon ; the sides of the cylinder are likewise perforated, as 
represented in fig. 16. Ignited charcoal is then placed all round the retort, the bottom of 
which protruding, out of the influence 
of the heat, allows the ebullition to 
proceed from the sides only. It is 
well to put into the retort a few frag- 
ments of quartz or a few lengths of 
platinum wire, the effect of which is 
to render the ebullition more regular. 

15. In order to prevent the acid 
fumes from condensing in the neck 
of the retort, it should be covered 
with a cover of sheet iron, as repre- 
sented in fig. 16. 

16. The first fourth part which dis- 
tils over should be rejected, because 

it is too weak ; the next two-fourths are kept, and the operation is then stopped, leaving 
the last fourth part of the acid in the retort. The neck of the retort should be about four 
feet long, and about one and a half inches in the bore, and be connected with a large re- 
ceiver ; and as the necks of retorts are generally much too short for the purpose, an adapter 
tube should be adjusted to it and to the receiver, but very loosely ; this precaution is ab- 
solutely necessary, for otherwise the hot acid falling on the sides of the receiver would 
crack it ; things, in fact, should be so arranged that the hot drops of the distilling acid may 
fall into the acid which has already distilled over. Do not surround the receiver with cold 
water, for the hot acid dropping on the refrigerated surface would also certainly crack it. 
The acid so obtained is pure oil of vitriol, or monohydrated sulphuric acid, SO 3 , HO, and it 
should be kept in a well-stoppered and dry flask. 

17. For commercial assays, however, and, indeed, for every purpose, the ordinary con- 
centrated sulphuric acid answers very well : when used for the determination of the value of 
potashes, it is made of such a strength that each division (or 10 water-grains' measure) of 
the alkalimeter saturates exactly one grain of pure potash : an acid of that particular 
strength is prepared as follows : — 

18. Take 112-76 grains of pure neutral and anhydrous carbonate of soda, and dissolve 
them in about 5 fluid ounces of hot water.* This quantity, namely, 112-76 grains, of 
neutral carbonate of soda will exactly saturate the same quantity of pure sulphuric acid (SO 3 ) 
that 100 grains of pure potash would. It is advisable, however, to prepare at once a larger 
quantity of test solution of carbonate of soda, which is of course easily done, as will be 
shown presently. 

* Anhydrous, or dry, neutral carbonate of soda may bo obtained by keeping a certain quantity of 
pure bicarbonate of soda for a sbort time, at a dull red heat, in a platinum crucible : tbc bicarbonate is 
c inverted into its neutral carbonate, of course free from water. 




19. Mix, now, 1 part, by measure, of concentrated sulphuric acid with 10 parts of 
water, or rather — as it is advisable, where alkalimetrical assays have frequently to be made, 
to keep a stock of test acid — mix 1,000 water-grains' measure of concentrated sulphuric 
acid with 10,000 grains of water, or any other larger proportions of concentrated sulphuric 
acid and water, in the above respective proportions ; stir the whole well, and allow it to 
cool. The mixture of the acid with the water should be made by first putting a certain 
quantity of the water into a glass beaker or matrass of a suitable size, then pouring the 
concentrated acid slowly therein, while a gyratory motion is imparted to the liquid. The 
vessel containing the acid is then rinsed with the water, and both the rinsing and the rest 
of the water are then added to the whole mass. When quite cold, fill the graduated alka- 
limeter with a portion of it up to the point marked 0°, taking the under line of the liquid 
as the true level ; and, whilst stirring briskly with a glass rod the aqueous solution of the 
112.76 grains of neutral carbonate of soda above alluded to, drop the test acid from the 
alkalimeter into the vortex produced by stirring, until, by testing the alkaline solution with 
a strip of reddened litmus-paper after every addition of acid, it is found that it no longer 
shows an alkaline reaction, (which is known by the slip of reddened litmus-paper not being 
rendered blue,) but, on the contrary, indicates that a very slight excess of acid is present, 
(which is known by testing with a slip of blue litmus-paper, which will then turn slightly 

20. If, after having exhausted the whole of the 100 divisions (1,000 water-grains' 
measure) of the diluted acid in the alkalimeter, the neutralization is found to be exactly 
attained, it is a proof that the test acid is right. 

21. But suppose, on the contrary, (and this is a much more probable case,) suppose that 
only 80 divisions of the acid in the alkalimeter have been required to neutralize the alka- 
line solution, it is then a proof that the test acid is too strong, and accordingly it must be 
further diluted with water, to bring it to the standard strength ; and this may at once be 
done, in the present instance, by adding 20 measures of water to every 80 measures of the 
acid. This is best accomplished by pouring the whole of the acid into a large glass cylin- 
der, divided into 100 equal parts, until it reaches the mark or scratch corresponding to 80 
measures ; the rest of the glass, up to 100, is then filled up with water, so that the same 
quantity of real acid will now be in the 100 measures as was contained before in 80 

22. The acid adjusted as just mentioned should be labelled " Test Sulphuric Acid for 
Potash" and kept in well-stoppered bottles, otherwise evaporation taking place would ren- 
der the remaining bulk more concentrated, consequently richer in acid than it should be, 
and it would thus, of course, become valueless as a test acid until readjusted. Each degree 
or division of the alkalimeter of such an acid represents 1 grain of pure potash. 

23. The alkalimetrical assay of soda is also made with sulphuric acid, in preference to 
other acids, but it must be so adjusted that 100 alkalimetrical divisions (1,000 water-grains' 
measure) of acid will exactly neutralize 170 - 98 of pure anhydrous carbonate of soda, that 
quantity containing 100 grains of pure soda. 

24. Dissolve, therefore, 171 grains of pure anhydrous neutral carbonate of soda, ob- 
tained as indicated before, in five or six ounces of hot water, and prepare in the meantime 
the test sulphuric acid, by mixing 1 part, by measure, of ordinary concentrated sulphuric 
acid, with about 9 parts, by measure, of water, exactly as described before ; stir the whole 
thoroughly, let the mixture stand until it has become quite cold, then pour 1,000 water- 
grains' measure of the dilute acid so prepared into an alkalimeter — that is to say, fill that 
instrument up to 0°, taking the under line as the true level, and then, whilst stirring briskly 
the aqueous solution of the 1*71 grains of carbonate of 6oda with a glass rod, pour the acid, 
with increased precaution as the saturating point is approaching, into the vortex produced, 
until by testing the liquor alternately with reddened and with blue litmus-paper, or with 
gray litmus-paper, as before mentioned, the exactly neutralized point is hit. 

25. If the whole of the 100 alkalimetrical divisions (1,000 water-grains' measure) have 
been required to effect the neutralization, it is a proof that the acid is of the right strength ; 
but if this be not the case, it must be adjusted as described before — that is to say : — 

26. Suppose, for example, that only 75 alkalimetrical divisions or measures of the acid 
in the alkalimeter have been required to neutralize the 171 grains of neutral carbonate of 
soda operated upon, then 75 measures of the acid should be poured at once into a glass 
cylinder accurately divided into 100 parts ; the remaining 25 divisions should then be filled 
with water, and the whole being now stirred up, 100 parts of the liquor will of course con- 
tain as much real acid as 75 parts contained before, and accordingly the acid may now be 
used as a test acid for the alkalimetrical assay of soda, each degree or division of the alka- 
limeter representing one grain of pure soda. 

27. The stock of test acid should be kept in well-stoppered flasks, that it may not vary 
in strength by evaporation, and be labelled " Test Sulphuric Acid for Soda.'''' 

28. Instead, however, of keeping two kinds of " test sulphuric acid," of different satu- 
rating powers as described, the one for potash, the other for soda, one kind only may be 




E 45 


prepared so as to serve for both alkalis, by constructing, as is very often done, an alkalime- 
ter adjusted so as to indicate the quantities of the acid of a given strength required for the 
saturation or neutralization of both potash or soda, or of their respective carbonates ; and 
this, in fact, is the alkalimeter most in use in the factory. 

It should be in shape similar to that of Gay-Lussac's, (see fig. 12,) or that described in 
figs. 13 and 14 ; but, like that represented by fig. 11, it generally consists of a tube closed 
at one end, about three-fourths of an inch internal diameter and about 9+ inches in length ; 
it is graduated into 100 equal parts, and every division is numbered from above downwards 
(see fig. 17). 

The following directions for their construction are given by Professor Faraday : " Let 
the tube represented in the margin have 100° grains of water weighed into 
it ; then let the space it occupies be graduated into 100 equal parts, and 17 

every ten divisions numbered from above downwards. At 22 - l parts, or 
77"9*9 parts from the bottom, make an extra line, a little on one side or even 
on the opposite side of the graduation, and write at it with a scratching dia- 
mond, soda ; lower down, at 48 - 62 parts, make another line, and write 
potash; still lower, at 54 - 43 parts, a third line marked carb. soda; and at 
65 part, a fourth, marked carb. potash. It will be observed that portions 
are measured off beneath these marks in the inverse order of the equivalent 
number of these substances, and consequently directly proportionate to the 
quantities of any particular acid which will neutralize equal weights of the 
alkalis and their carbonates. As these points are of great importance, it soda.- 
will be proper to verify them by weighing into the tubes first 350, then 
513'8, and lastly 779'9 grains of water, which will correspond with the marks 
if they are correct, or the graduation may be laid down from the surface of 
the four portions of fluid when weighed in, without reference to where they 
fall upon the general scale. The tube is now completed, except that it 
should be observed whether the aperture can be perfectly and securely cov- wtasit- 
ered by the thumb of the left hand, and if not ; or, if there be reason to think cars.sooa- 
it not ultimately secure, then it should be heated and contracted until suffi- 
ciently small." c/iRa '. 

29. The test acid for this alkalimeter should have a specific gravity of P0TASH ' 
1.1268 ; and such an acid may be prepared by mixing one part, by weight, 
of sulphuric acid, specific gravity 1'82, with four parts of water, and allow- 
ing the mixture to cool. In the meantime, 100 grains of pure anhydrous 
carbonate of soda, obtained as indicated before, should be dissolved in water, 
and the test sulphuric acid, of specific gravity 1-1268, prepared as abovesaid, 
having become quite cool, is poured into the alkalimeter up to the point 
marked carbonate of soda, the remaining divisions are filled up with water, 
and the whole should be well mixed by shaking. 

80. If the whole of the sulphuric acid, adjusted as was said, being poured carefully 
into the solution of the 100 grains of the neutral carbonate of soda, neutralize them 
exactly — which is ascertained, as usual, by testing the solution with litmus-paper, which 
should not be either reddened or rendered bluer by it — it is of course a sign that the test 
is as it should be — that is to say, is of the proper strength ; in the contrary case, it must be 
finally adjusted in the manner already indicated, and which need not be repeated. See 
g§ 20, 21. 

31. The best and most convenient process for the analyst, however, consists in prepar- 
ing a test acid of such a strength that it may serve not only for all alkalis, but indeed for 
every base ; that is to say, by adjusting the test acid so that 100 alkalimetrical divisions of 
it (1,000 water-grains' measure) may exactly saturate or neutralize one equivalent of every 
base. This method, which was first proposed by Dr. Ure, is exceedingly convenient, and 
the possession of two reciprocal test liquids, namely the ammonia test liquor of a standard 
strength, of which we gave a description in the article on Acidimetry, and the standard test 
acid of which we are now speaking, affords, as Dr. Ure observes, ready and rigid means of 
verification. For microscopic analysis of alkaline and of acid matter, a graduated tube of 
a small bore, mounted in a frame, with a valve apparatus at top, so as to let fall drops of 
any size and at any interval, is desirable ; and such an instrument Dr. Ure employed for 
many years ; but instead of a tube with a valve apparatus at top, the operator may use a 
graduated tube of a small bore, terminated by a small length of vulcanized india-rubber 
tube pinched in a clamp, which may be relaxed in such a way as to permit also the escape 
of drops of any size at any interval of time, the little apparatus being under perfect 

32. The test sulphuric acid, of such a strength that 100 alkalimetrical divisions of it 
can saturate one equivalent of every base, should have a specific gravity of 1 -032, and is 
prepared as follows : — 

Take 53 grains (one equivalent) of pure anhydrous neutral carbonnt" of soda, obtained 





in the manner indicated before, (see § 18,) and dissolve them in about one fluid ounce of 
water. Prepare, in the meantime, the l^st sulphuric acid by mixing one part, by measure, 
of concentrated sulphuric acid with about 11 or 12 parts of water, and stir the whole well. 
The mixture having become quite cold, fill the alkalimeter with the cold diluted acid up to 
the point marked 0°, taking the under line of the liquid as the true level, and, whilst stir- 
ring briskly the aqueous solution of the 53 grains of carbonate of soda above alluded to, 
pour the acid carefully from the alkalimeter into the vortex produced by stirring, until, by 
testing the liquor alternately with reddened and with blue litmus-paper, or, more conve- 
niently still, with gray litmus-paper, the neutralizing point is exactly hit. 

33. If the whole of the 100 divisions of the alkalimeter had been required to neutralize 
exactly the 53 grains of pure anhydrous carbonate of soda, it would be a proof that the 
acid is of the right strength ; but if this is not the case, it must be adjusted in the manner 
described before, that is to say : — 

34. Let us suppose, for example, that only 50 measures in the alkalimeter have been 
required to saturate or neutralize the 53 grains of carbonate of soda, then 50 measures 
should be poured at once into a glass cylinder accurately divided into 100 parts, the remain- 
ing 50 divisions should be filled up with water, and the whole being well stirred, 100 parts 
of the acid liquor will now contain as much real acid as was contained before in the 50 

35. The acid may now be labelled simply, " Test or Normal Sulphuric Acid.'''' Each 
one hundred alkalimetrical divisions, or 1,000 water-grains' measure of it, contain one 
equivalent, or 40 grains of real sulphuric acid ; and, consequently, each 100 alkalimetrical 
divisions of it will neutralize one equivalent, or 31 grains of soda, 47 of potash, 17 of 
ammonia, 28 of lime, and so forth, with respect to any other base. 

86. The stock of test or normal sulphuric acid should, as usual, be kept in well-stop- 
pered bottles, in order to prevent concentration by evaporation. By keeping in the flask 
containing it a glass bead, exactly adjusted to the specific gravity of 1-032, the operator 
may always ascertain, at a glance, whether the acid requires readjusting. 

37. With a Schuster's alkalimeter, it is convenient to prepare the test acid of such a 
strength that, according as it has been adjusted for potash or for soda, 10 grains of it will 
exactly saturate one grain of one or the other of these bases in a pure state. It is consid- 
ered that the alkalimeter may be charged with a known weight of any of the other sul- 
phuric test acids of a known strength. Suppose, for example, that the test sulphuric acid 
taken have a specific gravity of T032, we know, as we have just shown, that 1-032 grains' 
weight of that acid contains exactly one equivalent of pure sul- 
phuric acid = 40, and is capable, therefore, of neutralizing one 
equivalent of any base ; and, consequently, by taking a certain 
weight of this acid before beginning the assay, and weighing what 
is left of it after the assay, it is very easy to calculate, from the 
quantity of acid consumed in the experiment, what quantity of base 
has been neutralized. Thus a loss of 21-96 — 60-70 — 33-29 
grains' weight of this test acid represents one grain of potash, of 
ammonia, of soda respectively, and so on with the other bases. 

38. The operator being thus provided with an appropriate test 
acid, we shall now describe how he should proceed with each of 
them in making an alkalimetrical assay with potash. 

In order to obtain a reliable result, a fair average sample must 
be operated upon. To secure this the sample should be taken from 
various parts of the mass, and at once put in a wide-mouth bottle, 
and well corked up until wanted ; when the assay has to be made, 
the contents of the bottle must be reduced to powder, so as to 
obtain a fair mixture of the whole ; of this weigh out 1,000 grains 
exactly — or less, if that quantity cannot be spared — and dissolve 
them in a porcelain capsule in about 8 fluid ounces of distilled hot 
water, or in that proportion ; and if there be left any thing like an insoluble residue, filter, 
in order to separate it, and wash it on the filter with small quantities of distilled water, and 
pour the whole solution, with the washings and rinsings, into a measure divided into 10,000 
water-grains' measure. If the water used for washing the insoluble residue on the filter 
has increased the bulk of the solution beyond 10,000 water-grains' measure, it must be 
reduced by evaporation to that quantity ; if, on the contrary, the solution poured in the 
measure stands below the mark 10,000 water-grains' measure, then as much water must be 
added thereto as will bring the whole mass exactly to that point. In order to do this cor- 
rectly, the cylindrical measure should stand well on a table, and the under or lower line 
formed by the liquid, as it reaches the scratch 10,000, is taken as the true level. 

39. This being done, 1,000 grains' measure of the filtrate, that is to say, one-tonth part 
of the whole solution, is transferred to a glass beaker, in which the saturation or neutraliza- 
tion is to be effected, which is best done by means of a pipette capable of containing 



exactly that quantity when filled up to the scratch, a. In order to fill such a pipette it ia 
sufficient to dip it into the alkaline solution and to suck up the liquor a little above 
the scratch, a ; the upper orifice should then be stopped with the first finger, and by -j q 
momentarily lifting it up, the liquor is allowed slowly to fall from the pipette back 
again into the 10,000 grains' measure until its level reaches exactly the scratch, a. 
The last drop which remains hanging from the point of the pipette may be readily 
detached by touching the sides of the glass measure with it. The 1,000 grains being 
thus rigorously measured in the pipette should then be transferred to the glass 
beaker, in which the neutralization is to take place, by removing the finger alto- 
gether, blowing into it to detach the last drop, and rinsing it with a little water. 

40. Or, instead of the pipette just described, the operator may measure 1,000 
grains by taking an alkalimeter full of the alkaline solution, and emptying it into 
the glass beaker in which the neutralization is to take place, rinsing it with a little 
water, and of course adding the rinsing to the mass in the said glass beaker. 

41. Whichever way is adopted, a slight blue color should be imparted to the 
1,000 grams' measure of the alkaline solution, by pouring into it a small quantity 
of tincture of litmus. The glass beaker should then be placed upon a sheet of \l 
white paper, or a slab of white porcelain, in order that the change of color produced 

by the gradual addition of the test acid may be better observed. 

42. This being done, if the operator have decided upon using the test sulphuric, for 
potash (§§ 1*7-22), he should take one of the alkalimeters, represented in figs. 11, 12, 13, 
or 14, and fill it up to 0°, (taking the under line of the liquid as the true level ;) then taking 
the alkalimeter thus charged in his right hand, and in his left the glass beaker containing 
the alkaline solution colored blue by tincture of litmus, he should gradually and carefully 
pour the acid liquor into the alkaline solution in the glass beaker, to which a circular motion 
should be given whilst pouring the acid, or which should be briskly stirred, in order to 
insure the rapid and thorough mixing of the two liquors, and therefore their complete reac- 
tion ; moreover, in order at once to detect any change of color from blue to red, the glass 
beaker should be kept over the white sheet of paper or the white porcelain slab, as before 

43. At first no effervescence is produced, because the carbonic acid expelled, instead of 
escaping, combines with the portion of the alkaline carbonate as yet undecomposed, which 
it converts into bicarbonate of potash, and accordingly no sensible change of color is per- 
ceived ; but as soon as a little more than half the quantity of the potash present is satu- 
rated, the liquor begins to effervesce, and the blue color of the solution is changed into one 
of a vinous, that is, of a purple or bluish-red hue, which is due to the action of the car- 
bonic acid upon the blue color of the litmus. More acid should be still added, but from 
this moment with very great care and with increased caution, gradually as the point of neu- 
tralization is approached, which is ascertained by drawing the glass rod used for stirring the 
liquor across a slip of blue litmus-paper. If the paper remains blue, or if a red or reddish 
streal* is thereby produced which disappears on drying the paper and leaves the latter blue, 
it is a proof that the neutralization is not yet complete, and that the reddish streak was due 
only to the action of the carbonic acid ; more acid must accordingly be poured from the 
alkalimeter, but one drop only at a time, stirring after each addition, until at last the liquor 
assumes a distinct red or pink color, which happens as soon as it contains an extremely 
slight excess of acid ; the streaks made now upon the litmus-paper will remain permanently 
red, even after drying, and this indicates that the reaction is complete, and that the assay is 

44. If the potash under examination were perfectly caustic, the solution would suddenly 
change from blue to pink, because there would be no evolution of carbonic acid at all, and 
consequently no vinous or purple color produced ; if, on the other hand, the potash- was 
altogether in the state of bicarbonate, the first drops of test acid would at once decompose 
part of it and liberate carbonic acid, and impart a vinous color to the solution at the very 
outset, which vinous color would persist as long as any portion of the bicarbonate would 
remain undecomposed. 

45. The neutralizing point being attained, the operator allows the sides of the alkalim- 
eter to drain, and he then reads off the number of divisions which have been employed. If, 
for example, 50 divisions have been used, then the potash examined contained 50 per cent, 
of real potash. See observ., §48-49. 

46. Yet it is advisable to repeat the assay a second time, and to look upon this first de- 
termination only as an approximation which enables the operator, now that he knows about 
where the point of neutralization lies, to arrive, if need be, by increased caution as he 
reaches that point, at a much greater degree of precision. He should accordingly take 
again an alkalimeter full (1,000 water-grains' measure) — that is to say, another tenth part 
of the liquor left in the 10,000 grains' measure — and add thereto at once 48 or 49 alka- 
limetrical divisions of the test acid, and after having thoroughly agitated the mixture, pro- 
seed to pour the acid carefully, two drops only at a time, stirring after such addition, and 

Vol. III.— 4 



touching a strip of litmus-paper with the end of the glass rod used for stirring ; and so he 
should go on adding two drops, stirring, and making a streak on the litmus-paper, until the 
liquor assumes suddenly a pink or onion-red color, and the streak made on the litmus-paper 
is red also. The alkalimeter is then allowed to drain as before, and the operator reads off 
the number of divisions employed, from which number two drops (or T 2 ff of a division) 
should be deducted ; Gay-Lussac having shown that, in alkalimetrical assays, the sulphates 
of alkalis produced retard the manifestation of the red color in that proportion. One alka- 
limetrical division generally consists of 10 drops, but as this is not always the case, the 
operator should determine for himself how many drops are necessary to make up one 
division, and take account of them in the assay according to the ratio thus found. In the 
example given before, and supposing 10 drops to form one alkalimetrical division, then the 
percentage value of the sample of potash under examination would probably be as 
follows : — 

Number of divisions of acid employed, 
— 2 drops acid in excess, 

Real percentage of potash, 



47. When the alkalimeter described in fig. 13 is employed, the test acid may, at the 
beginning of the experiment, be poured from the larger opening, e ; but towards the end — 
that is, when the neutralizing point is approaching — the acid should be carefully poured 
from the point, d, in single drops, or only two drops at a time, until the saturating point is 
hit, as we have just said. If the operator wishes to pour only one drop, he should close the 
larger opening, e, of the bulb with the thumb, and then fill the bulb with the test acid by 
inclining the alkalimeter ; putting now the alkalimeter in an upright position, and removing 
the thumb, a certain quantity of acid will be retained in the capillary point, d ; and if the 
thumb be now pressed somewhat forcibly against the opening, e, the acid contained in the 
capillary point will be forced out, and form one drop, which will then fall into the alkaline 
solution if it be held over it. If the saturation be complete, the operator, without remov- 
ing the bulb stopper, may, by applying^his lips to the large opening, e, suck the acid en-, 
gaged in the capillary point back into the alkalimeter. 

48. If there should be in the mind of the operator any doubt as to what is meant by the 
onion-red color which the liquor tinged blue with tincture of litmus acquires when slightly 
supersaturated, he may pour into a glass beaker a quantity of pure water equal to, or even 
larger than, the alkaline solution operated upon, and tinge it blue with a little tincture of 
litmus, to about the same degree of intensity as the alkaline liquor under examination'. If 
he now pour into the pure water colored blue with litmus, one single drop of the test acid, 
it will acquire at once, by stirring, the onion-red color alluded to, and which he may now 
use as a standard of comparison. 

49. Considering the rapidity with which these alkalimetrical operations can be per- 
formed, the operator, unless he has acquired sufficient practice, or unless a great degree 
of accuracy be not required, should repeat the assay two or three times, looking upon the 
first determination only as an approximation, and as a sort of guide as to the quantity of 
acid which will be required in the subsequent experiments, whereby he will now be enabled 
to proceed with increased caution as he approaches the point of saturation ; but, at any 
rate, if he will not take the little extra trouble of a repetition, he should, before he begins 
to pour the acid, take a little of the filtered alkaline solution out of the glass beaker, as a 
corps de reserve, which he adds to the rest after the saturating point has been approximated, 
and from that moment he may proceed, but with great care, to complete the neutralization 
of the whole. 

50. Do not forget that, as the test sulphuric acid must always be added in sliglit excess 
to obtain a distinct red streak on the litmus-paper, a correction is absolutely necessary ; 
that is to say, the excess of sulphuric acid employed must be deducted if a strictly accurate 
result is sought. 

51. If, instead of the special alkalimeter for potash above described, the operator pre- 
fers using that prepared of such a strength that 100 divisions of the alkalimeter (100 water- 
grains' measure) contain exactly one equivalent of each alkali or base, which test sulphuric 
acid, as we have seen, has a specific gravity of 1.032, (see §§ 31-36,) he should proceed 
exactly as indicated in § 38, and following ; and the alkalimeter being filled with that test 
acid, of specific gravity 1.032 up to 0°, it (the acid) should be poured carefully into the 
aqueous solution of the alkali tinged blue with litmus, until exact neutralization is attained, 
precisely in the same manner as in § 38, and following. 

52. The neutralizing point being hit, let us suppose that the whole of the contents of 
the alkalimeter have been employed, that the aqueous solution tinged blue with litmus, is 
not yet saturated, and that, after having refilled the alkalimeter, the 4 divisions more {alto- 
gether 104 divisions) have been required to neutralize the alkali in the aqueous solution ; 
then, since 100 divisions (1,000 water-grains' measure) of the test acid now employed satu- 


rate exactly one equivalent, that is, 47 of potash, the question is now, What quantity of 
potash will have, been saturated by the 104 divisions of acid employed ? The answer is 
found by a simple rule of proportion, to be nearly 49. 

100 : 47 :: 104 : x = 48-88. 

The sample of potash examined contained, therefore, nearly 49 per cent, of pure potash. 

53. If, instead of the special test sulphuric acid for potash, (§ 17,) or of the test sul- 
phuric acid for potash, and other bases, (§ 28,) the operator uses the potash and soda alka- 
limeter, (§§ 31-36,) the method to be followed is exactly similar to that described in § 42, 
and following. Some of the test sulphuric acid, of specific gravity 1-1268, is to be poured 
into the alkalimeter until it reaches the point marked ''potash" (that is to say, 48-62 
divisions of the alkalimeter,) taking the under line of the liquid as the true level, and the 
remaining divisions up to 0° are carefully filled with water. The operator then closes the 
aperture of the alkalimeter with the thumb of his left hand, and the whole is violently 
shaken so as to obtain a perfect mixture. 

54. The acid so mixed must now be carefully poured from the alkalimeter into the alka- 
line solution of the potash under examination until neutralization is attained, precisely as 
described in § 42, and following. 

55. The neutralizing point being hit, the operator allows the sides of the alkalimeter to 
drain, and he then reads off the number of divisions employed in the experiment, which 
number indicates the percentage of real potash contained in the sample. 

56. Had the operator wished to estimate the quantity of potash as carbonate of potash, 
he should have poured the test acid into the alkalimeter up to the point marked "carbonate 
of potash," filled the remaining divisions of the alkalimeter up to 0° with water, and pro- 
ceeding exactly as just mentioned, the number of divisions of acid employed would indi- 
cate the percentage of potash contained in the sample as carbonate of potash. 

57. If a Schuster's alkalimeter (fig. 15) be used, and supposing, for example, that the 
acid to be employed therewith is so adjusted that 10 grains' weight of it neutralize exactly 
1 grain in weight of potash, proceed as follows: — Take 100 grains in weight of a fair 
average of the sample, previously reduced to powder, dissolve them in water, filter with the 
precautions which have already been described before, (§ 38, and following,) and pour this 
solution into a glass cylinder graduated into 100 parts, and capable of containing 10,000 
water-grains ; fill it up with water exactly as described before ; of this take now 100 alka- 
limetrical divisions, that is to say, -Jg. of the whole solution, and pour it into a glass 
beaker. On the other hand, charge the Schuster's alkalimeter with a certain quantity of the 
test acid, and weigh it, along with the alkalimeter itself, in a good balance. This done, pro- 
ceed with the neutralization of the solution in the glass beaker, by pouring the acid from 
the alkalimeter in the usual way, and with the usual precautions, until the saturation is 
completed. Replace the alkalimeter, with the quantity of unconsumed acid, in the scale 
of the balance, weigh accurately, and since every grain of acid represents ^ of a grain 
of potash, the number of grains of acid used in the experiment indicates at once the per- 
centage of real potash present in the sample. 

58. "When, however, potash is mixed with soda, as is frequently the case with the pot- 
ash of commerce, either accidentally or for fraudulent purposes, the determination of the 
amount of the cheaper alkali could not, until a comparatively recent period, be estimated, 
except by the expensive and tedious process of a regular chemical analysis. In 1844, how- 
ever, M. Edmund Pesier, Professor of Chemistry at Valenciennes, published an easy and 
commercial method for the estimation of the quantity of soda which potash may contain, 
by means of an areometer of a peculiar construction, to which the name of " Natrometer " 
has been given by the talented professor. 

59. The rationale of the method is grounded upon the increase of specific gravity which 
sulphate of soda produces in a solution saturated with pure sulphate of potash, and is de- 
duced from the fact that a solution saturated with neutral sulphate of potash possesses a 
uniform and constant density when the saturation is made at the same temperature, and 
that the density of such a solution increases progressively in proportion to the quantity of 
sulphate of soda present ; an increase of density so much the more readily observable, that 
the solubility of the sulphate of potash is greatly augmented by the presence of sulphate of 
soda. It had at first been thought that, in order to obtain any thing like accuracy, it would 
be necessary to combine all the potash with one same acid, preferably sulphuric acid ; and, 
consequently, that as the potash of commerce always contains a little, and sometimes 
a rather considerable quantity, of chloride of potassium, the latter salt should first be 
decomposed. Further experiments, however, established the fact, that in dissolving chlo- 
ride of potassium in a saturated solution of sulphate of potash, the specific gravity of the 
liquor is not materially increased, since the introduction of as much as 50 per cent, of 
chloride of potassium does not increase that density more than 3 per cent, of soda would 
do when examined by the natrometer — a degree of accuracy quite sufficient for commercial 
purposes. When soda is added to a saturated solution of sulphate of potash, the further 




addition of chloride of potassium thereto renders the specific gravity of the liquor less than 
it would have been without that addition — an apparent anomaly due to the fact that 
chlorine, in presence of sulphuric acid, of potash, and of soda, combines with the latter base 
to form chloride of sodium ; and it is this salt which increases the solubility of sulphate of 
potash, though in a somewhat less degree than sulphate of soda. Thus, if to a saturated 
solution of sulphate of potash 0-14 of soda be added along with - 20 of chloride of potas- 
sium, the natrometer indicates only - 125 of soda. Seeing, therefore, that in such an 
exceptional case the error does not amount to more than O015 of error, it will probably be 
found unnecessary in most cases to decompose the chloride contained in the potashes of 
commerce, that quantity being too small to materially affect the result. Yet, as the accurate 
determination of soda in potash was a great desideratum, M. Pesier contrived two processes,' 
one of which, in the hands of the practised chemist, is as perfect as, but much more rapid 
than, those ordinarily resorted to ; the other, which is a simplification of the first, yields 
results of sufficient accuracy for all commercial purposes. 

60. First process. — Take 500 grains of a fair average sample of the potash to be 
examined, dissolve them in as little water as possible, filter, and wash the filter until the 
washings are no longer alkaline. This filtering, however, may be dispensed with when the 
potash is of good quality and leaves but a small residue, or when an extreme degree of 
accuracy is not required. 

61. The potash being thus dissolved, a slight excess of sulphuric acid is added thereto •, 
the excess is necessary to decompose the chlorides and expel the muriatic acid. The liquor 
so treated is then evaporated in a porcelain capsule, about six inches in diameter ; and 
when it begins to thicken it should be stirred with a glass rod, in order to avoid projections. 
When dry, the fire must be urged until the residue fuses, and it is then kept in a state of 
tranquil fusion for a few minutes. The capsule should then be placed upon, and surrounded 
wit, hot sand, and allowed to cool down slowly, to prevent its cracking, which would happen 
without this precaution. 

62. The fused mass in the capsule having become quite cold, should now be treated 
with as little hot water as possible, that is to say, with less than 3,000 grains of hot water ; 

and this is best done by treating it with successive portions of fresh 
water. All the liquors thus successively obtained should then be 
poured into a flask capable of holding about 10,000 grains of 
water, and the excess of sulphuric acid must be accurately neutral- 
ized by a concentrated solution of pure carbonate of potash — that 
is to say, until the color of litmus-paper is no longer affected by 
the liquor, just as in ordinary alkalimetrical or acidiruetrical assays. 
During this operation, a pretty considerable precipitate of sulphate 
of potash is, of course, produced. 

63. The neutralizing point being exactly hit, a saturated solu- 
tion of sulphate of potash is prepared, and brought, to the atmos- 
pheric temperature ; a condition which is expedited by plunging 
the vessel which contains the solution into a basin full of cold 
water, and stirring it until the thermometer plunged in the liquor 
indicates that the temperature of the latter is about the same as, 
and preferably less than, that of the air ; because, in the latter 
case, it may be quite correctly adjusted by grasping the vessel 
with a warm hand. In order, however, to secure exactly the prop- 
er temperature, the whole should be left at rest for a few min- 
utes after having withdrawn the vessel from the basin of cold water 
used for refrigerating it, taking care simply to stir it from time 
to time, and to ascertain that the thermometer remains at the same 
degree of temperature. This done, the liquor is filtered into a 
glass cylinder, c, on which a scratch, h-i, has been made, cor- 
responding to 3,000 water-grains' measure. If the directions given 
have been exactly followed, it will be found that the filtrate is 
not sufficient to fill it up to that mark ; the necessary volume, 
however, should be completed by washing the deposit of sulphate 
of potash in the filter, b, with a saturated solution of the same salt 
(sulphate of potash) previously prepared. It is advisable to use a 
saturated solution of sulphate of potash which has been kept for 
some time, and not one immediately prepared for the purpose, be- 
cause sulphate of potash, in dissolving, produces a certain amount 
of cold, which would create delay, since it would be necessary to 
wait until the temperature of the mass had become the same as 
that of the air. 
64. The liquor occupying 3,000 water-grains' measure in the cylinder, should be next 
tendered homogeneous by stirring it well, after which the natrometer may be immersed in 



it. The natrometer is simply an areometer of a peculiar construction, provided with two 
scales : the one of a pink color shows the degrees of temperature, and indicates, for each 
decree of the centigrade thermometer, the level at which a solution saturated with pure 
sulphate of potash would stand ; on the other scale, each degree represents 1 per cent, of 
soda, (oxide of sodium,) as represented in fig. 21. 

65. The 0° of the two scales coincide with each other. If the experiment take place at 
the temperature of 0°, the quantity of soda will be directly determined by observing the 
number of degrees on the soda scale ; but if the experiment be performed at 25°, for exam- 
ple, it will be seen that the point at which the instrument would sink in the liquor saturated 
with pure sulphate of potash corresponds to T | T of soda ; and, in this case, it is from this 
point that the 0° of the soda scale should be supposed to begin, which is easily accom- 
plished by a simple subtraction, as will be seen presently. 

66. Experiment having shown that the degrees of soda cannot be equidistant, but that, 
on the contrary, they become smaller and smaller as the quantity of soda increases, the 
number of degrees of soda are obtained as follows: — From the number of degrees of tem- 
perature- now indicated on the pink scale of the natrometer, subtract the number of degrees 
of temperature indicated by an ordinary thermometer at starting ; then look at the soda 
scale for the number of soda degrees which correspond to the number of degrees of tem- 
perature left after subtraction, and each of the soda degrees, beginning from the 0° of the 
natrometer, represents 1 per cent • 

67. For example : — Suppose the experiment to have been made at starting, and as 
indicated by an ordinary thermometer, at -f- 20° centigrades, and that the level of the 
solution is now found to stand at 59° on the pink scale of temperature of the natrometer, 
then by deducting 20 (the original temperature) from 59 (number of degrees indicated by 
the floating point on the pink scale of temperatures of the natrometer) there remains, of 
course, 39. Draw the instrument out, and looking now on the said pink scale for 39°, there 
will be found exactly opposite, on the soda scale, the number 13, which number signifies 
that the potash under examination contains 13 per cent of soda, (oxide of sodium.) 

68. As the deposit of sulphate of potash separated by filtering might retain some sul- 
phate of stida, it is advisable, in order to avoid all chance of error, to wash it with a saturated 
solution of sulphate of potash, adding as much of it as is necessary to bring the whole mass 
of the liquor up to the mark 3,000 water-grains' measures, in which the natrometer being 
again immersed, the minute quantity of soda indicated should be added to the percentage 
found by the first operation. 

69. If a great degree of accuracy is required, the fractions of degree of the instrument 
must be taken account of; otherwise they may be neglected with- 
out the result being materially affected, since 3 degrees of the scale 
of temperature correspond only to about 1 per cent, of soda. 

70. For commercial purposes, the process may be slightly varied, 
as follows : — Take 500 grains of a fair average sample of the potash 
to be examined, previously reduced to powder, and throw them into 
a flask {fig. 22) capable of containing about 6,000 grains of water ; 
pour upon them about 2,000 grains of water, and shake until dis- 
solved. Add now sulphuric acid thereto^; this will produce a smart 
effervescence, and in all probability a deposit of sulphate of potash. 
We say in all probability, because it is clear that if the potash in 
question is largely adulterated with soda, or was altogether nothing 
else than carbonate of soda, as has occasionally happened, it is evi- 
dent that no deposit of sulphate of potash would take place ; and 
yet, as it is necessary to the success of the operation that the liquor 
should contain an excess of this latter salt, a certain quantity of it 
previously reduced to fine powder must in that case be purposely 
4dded to the solution. 

71. After the disengagement of gas has ceased, it is necessary 
to pour the dilute acid cautiously, and only drop by drop, until the 
neutralizing point is correctly hit, which will be known as usual by 
testing with litmus-paper. But if, by accident, too much acid has 
been used, which is known by the reddening of the litmus-paper, 
the slight overdose may be neutralized by adding a small quantity 
of weak solution of potash. 

72. As this reaction produces heat, it is necessary to lower the 
liquor down to the temperature of the atmosphere, decant in a filter 
placed over the glass cylinder, and fill it up to the scratch 3,000, by 
washing the residue on the filter with a saturated solution of sul- 
phate of potash, exactly as described in § 63. 

73. The glass cylinder being properly filled up to the scratch, remove the funnel, close 
the orifice of the glass cylinder with the palm of the hand, and shake the whole violently • 



holding the natrometer, which should be perfectly clean, by its upper extremity, slowly 
immerse it in the solution. If the potash under examination be pure, the pink scale will 
indicate the degree of temperature at which the experiment has been made, taking the 
under line as the true level of the liquid ; but if, on the contrary, it contains soda, the pink 
scale of temperatures will indicate a few degrees more than the real temperature, and this 
surplus number of degrees, being compared with those of the soda scale contiguous to it, 
on the opposite side, will express the percentage of soda present in the sample. 

74. For example : — Suppose the experiment to have been made at -j- 12° centigrade, and 
to have given a solution marking 25° on the pink scale of temperatures of the natrometer, 
that is, 13° more than the real temperature ; — looking therefore at number 1-3 on the pink 
scale of temperature, it will be seen that the number exactly opposite on the soda scale, and 
corresponding to it, is 4, which indicates that the sample of potash examined contains 4 per 
cent, of soda. 

It is important to bear in mind that all commercial potashes contain naturally a small 
quantity of soda, which quantity, in certain varieties, may even be considerable ; it is only 
when the proportion of soda is more considerable than that which is naturally contained in 
the species of potash submitted to analyisis, that it should be considered as fraudulently 
added. The following table, published by M. Pesier, shows the average composition of the 
principal varieties of potash found in commerce, when in an unadulterated state. 

Average Composition of 


Potashes obtain- 

ed in the Labo- 




ratory by cal- 








m =• 2 

*3 P . 


55 a 

O- S 

~ c 

~ B 

3 'a 

B< B 






-2 = * 


is "a 

1 > 







g * 



Sulphate of potash 











Chloride of potassium - 











Carhonate of potash 











Carbonate of soda (dry) 











Insoluble residue - 






Moisture - - - - 







Phosphoric acid, lime, silica, &e. 
Alkalimetric degrees 
















; 100-00 

100 00 









i 36.5 



75. The aljcalimetrieal assay of soda is performed exactly in the same manner as that 
of potash — that is to say : From a fair average sample of the soda to be examined, take 
1,000 grains' weight, (or less, if that quantity cannot be spared) and boil it five or six 
minutes in about eight fluid ounces of water ; filter, in order to separate the insoluble por- 
tion, and wash the residue on the filter with boiling water until it no longer drops from the 
filter with an alkaline reaction, and the bulk of the filtered liquid and the washings received 
in a graduated glass cylinder form 10,600 grains' measure. Should the water which may 
have been required. to wash the residue have increased the bulk of the solution beyond that 
quantity, it should be evaporated to reduce it to the bulk mentioned. 

76. This being done, 1,000 water-grains' measure — that is to say, ,-L part of the 
aqueous solution of the soda ash above mentioned (§ 75) — is transferred to the glass 
beaker or vessel in which the saturation is intended to take place, it is tinged distinctly blue 
with tincture of litmus, and the operation is performed in the same maimer and with the 
same precautions as for potash ; the glass beaker containing the blue alkaline solution being 
placed upon a sheet of white paper, or a slab of white porcelain, the better to observe the 
change of color which takes place when the saturating point is approaching. 

77. Having put into a glass beaker the 1,000 grains' measure of the aqueous solution of 
soda ash to be examined, (§ 75,) and of the test sulphuric acid for soda, described before, 
(§§ 23-27,) the alkalimeter, Jigs. 12, 13, 14, should be filled with that test acid up t the 
point marked 0°, (taking the under line of the liquid as the true level,) and poured therefrom 
with the precaution already indicated, stirring briskly, at the same time, the liquid in the 
beaker. As is the case with the alkalimetrical assay of potash, the carbonic acid expelled 

* In the impossibility of estimating exactly the loss by calcination, and the quantity of oxide of 
potassium in the caustic state, (hydrate of potash,) we have reduced the potash to the state of carbon- 
tte, to make comparison more easy. 



by the test acid reacting upon the as yet undecomposed portion of the soda ash, converts it 
into bicarbonate of soda, so that at first no effervescence is produced ; but as soon as half 
the quantity of the soda in the solution is saturated, a brisk effervescence takes place. At 
first, therefore, the operator may pour at once, without fear, a pretty large quantity of the 
test acid into the alkaline solution, but as soon as this effervescence makes its appearance, 
he should proceed with increased precaution gradually as the saturating point is approached. 
The modus operandi is, in fact, precisely as already detailed for the assay of potash, pre- 
cisely the same kind and amount of care is requisite, and the assay is known to be termi- 
nated when the streaks made upon the litmus-paper with the stirring rod remain distinctly 
and permanently of a pink color. 

78. After saturation, and after having allowed the sides of the alkalimeter to drain, the 
number of divisions at which the test acid stands in the alkalimeter indicate at once the 
percentage of the soda assayed, since, as we said, each division of this particular test acid 
represents one grain of pure soda. If, therefore, the test acid stands at 52 in the alkalimeter, 
then the soda assayed contained 52 per cent, of real soda. See, besides, the observations 
of § 48 and following, and also § 81. 

79. If, instead of the special test acid for soda just alluded to, the operator employs that 
which has a specific gravity of T032, and 100 alkalimetrical divisions of which saturate one 
equivalent of each base, the modus operandi is the same — that is to say, the alkalimeter is 
filled with it up to 0°, and it is poured therefrom carefully into the alkaline solution ; but 
as the equivalent of soda is 31, and 100 alkalimetrical divisions of the test sulphuric acid 
now employed are capable of saturating only that quantity of soda, it is clear that with the 
soda ash taken as an example in the preceding case, and containing 52 per cent, of real soda, 
the operator will have to refill his alkalimeter with the same test acid, and that a certain 
number of divisions of this second filling will have to be employed to perfect the saturation. 
In this instance the operator will find that nearly 68 divisions more, altogether 168 divisions 
(correctly, 167° 74) have been required to effect the saturation. 

80. If, instead of the special test sulphuric acid for soda, (§§ 23-27,) or the test sulphuric 
acid for potash, soda, and other bases, (§§ 31-34,) the operator uses the potash and soda 
alkalimeter, (§§ 28-35,) the method is always the same (§§ 74, 75) — that is to say, the 
aqueous solution of the soda ash is poured into the glass beaker, the difference being merely 
that instead of the alkalimeter being quite filled up with the test sulphuric acid, which, in 
the present instance, has a specific gravity of l - 268 (§ 29), the said test acid is poured into 
the alkalimeter only up to the point marked " soda,'" (taking the under line of the liquid as 
the true level,) and the remaining divisions of the alkalimeter are carefully filled up with 
water. The mouth of the tube should then be thoroughly closed with the thumb of the left 
hand, and the whole violently shaken until perfectly mixed, taking great care, of course, 
not to squirt any of the acid out of the tube, which evidently would cause an amount of 
error proportionate to the quantity of the test acid which would have thus been lost. The 
acid should then be poured from the alkalimeter with the usual precaution (§ 76) into the 
glass beaker containing the aqueous solution of the soda ash under examination, until com- 
plete neutralization is attained, stirring briskly all the time, or after each addition of the 
test acid. The neutralization point being hit, the sides of the alkalimeter are allowed to 
drain, and the operator then reads off the number of divisions employed, which number 
indicates the percentage of real soda contained in the sample assayed. Thus, if the sample 
operated upon be the same as that alluded to before, the number of divisions employed 
being 52 would indicate 52 per cent, of real soda. 

81. If the operator wishes to estimate the amount of soda in the sample as carbonate of 
soda, he should fill the alkalimeter with the test acid in question (specific gravity l - 268) up 
to the point marked carbonate of soda, and fill the remaining divisions with water, shake the 
whole well, and proceed with the neutralization of the -aqueous solution of the sample in the 
glass beaker as just described. Supposing, as before, that the sample in question contains 
52 per cent, of real soda, it will now be found that the number of divisions employed 
altogether to saturate the sample completely are very nearly 89, for 52 of caustic soda 
correspond to 88 - 90 of the carbonate of that alkali. 

82. If the soda ash is very poor, instead of operating upon 1,000 water-grains' measure, 
or one-tenth part of the whole solution, (= 100 grains' weight of the soda ash, §§ 70-77,) 
it is advisable to take three or four thousand water-grains' measure of the alkaline solution, 
and to divide, by three or four, the result obtained by saturation. Suppose, for example, 
that the quantity of real soda found is 46 ; this, if only 1,000 grains' measure had been 
taken, would, of course, indicate 46 per cent. ; but as 4,000 water-grains' measure of solu- 
tion has been taken instead, that number 46 must, accordingly, be divided by 4, which 
gives Hi per cent, only of real soda contained in the sample under examination. 

83. The soda ash of commerce contains generally a percentage of insoluble substances, 
which are removed by filtering, as we said, and a greater or less quantity of chloride of 
sodium (common salt) and of sulphate of soda, which, however, do not in the slightest degree 
interfere with the accuracy of the result. But there is a source of error resulting from the 



presence in the soda ash of sulphuret of calcium, of sulphite, and sometimes also, though 
more rarely, of hyposulphite, of soda. When sulphuret of calcium is present in the ash, on 
heating the latter by hot water, a double decomposition takes place, the sulphuret of cal- 
cium, reacting upon the carbonate of soda, forms sulphuret of sodium and carbonate of lime. 
Now sulphuret of sodium saturates the test acid just as carbonate of soda ; but as it has no 
commercial value, it is clear that if the ash contains a quantity of the useless sulphuret at 
all considerable, a very serious damage may be sustained by the purchaser if the percentage 
of that substance present in the ash be taken account of as being soda. Sulphite of soda is 
produced from the oxidization of this sulphuret of sodium, and is objectionable inasmuch 
that, when the test acid is added slowly to the aqueous solution of the ash, the effect is to 
convert the sulphite into bisulphite of soda, before any evolution of sulphuric acid, and con- 
sequently before the pink reaction on litmus-paper is produced. 

84. In order to obviate the inaccuracies resulting from the neutralization of a portion of 
the test acid by these substances, it is necessary to convert them into sulphates of soda, 
which is easily done by calcining a quantity of the sample with five or six per cent, of 
chlorate of potash, as recommended by Gay-Lussac and Welter. The operator, therefore, 
should intimately mix 50 or 60 grains' weight of pulverized chlorate of potash with 1,000 
grains of the pulverized sample, and fuse the mixture in a platinum crucible, for which 
purpose a blowpipe gas-furnace will be found exceedingly convenient. The fused mass 
should be washed, and the filtrate being received into a 10,000 water-grains 1 measure, and 
made up with water to occupy that bulk, may then be assayed in every respect as described 
before with one or other of the test acids mentioned. 

85. When, however, the soda ash contains some hyposulphite of soda — which fortunately 
is seldom the case, for this salt is very difficultly produced in presence of a very large excess 
of alkali — it should not be calcined with chlorate of potash, because in that case one equiv- 
alent of hyposulphite becomes transformed not into one equivalent of sulphate, but, reacting 
upon one equivalent of carbonate of soda, expels its carbonic acid, and forms with the soda 
of the decomposed carbonate a second equivalent of sulphate of soda, each equivalent of 
hyposulphite becoming thus converted into two equivalents of sulphate, and therefore creat- 
ing an error proportionate to the quantity of the hyposulphite present, each equivalent of 
which would thus destroy one equivalent of real and available alkali, and thus render the 
estimation of the sample inaccurate, and possibly to a very considerable extent. 

86. When this is the case, it is therefore advisable, according to Messrs. Fordos and 
Gelis, to change the condition of the sulphurets, sulphites, and hyposulphites, by adding a 
little neutral chromate of potash to the alkaline solution, whence result sulphate of chro- 
mium, water, and a separation of sulphur, which will not affect the accuracy of the alkalimet- 
rical process. 

87. Whether the sample to be analyzed contains any sulphuret, sulphite, or hyposul- 
phite, is easily ascertained as follows : — If, on pouring sulphuric acid upon a portion of the 
sample of soda ash under examination, an odor of sulphuretted hydrogen — that is, an odor 
of rotten eggs — is evolved, or if a portion of the soda ash, being dissolved in water, and 
then filtered, produces a black precipitate (sulphuret of lead) when solution of acetate of 
lead is poured into it, then the sample contains a sulphuret. 

88. And if, after adding to some dilute sulphuric acid as much bichromate of potash as 
is necessary to impart to it a distinct reddish-yellow tinge,, and a certain quantity of the solu- 
tion of the soda ash under examination being poured into it, but not in sufficient quantity to 
neutralize the acid, the reddish-yellow color becomes green, it is a proof that the sample 
contains either sulphite or hyposulphite of soda, the green tinge being due to the transforma- 
tion of the chromic acid into sesquioxide of chromium. 

89. And if, muriatic acid being poured into the clear solution of the soda ash, a turbid- 
ness supervenes after some time if left at rest, or at once if heat is applied, it is due to a 
deposit of sulphur, an odor of sulphurous acid being evolved, and hyposulphite of soda is 
probably present. We say probably, because if sulphurets and sulphites are present, the 
action of muriatic acid would decompose both, and liberate sulphuretted hydrogen and sul- 
phurous acid ; but as these two gases decompose each other, a turbidness due to a separation 
of sulphur is also formed ; thus 2HS + S O 2 = 2HO + 2S. 

90. As we have already had occasion to remark, the soda ash of commerce frequently 
contains some, and occasionally a large quantity of caustic soda, the proportion of which is 
at times important to determine. This may be done, according to Mr. Barreswill, by 
adding a solution of chloride of barium to the aqueous solution of the soda ash, by which 
the carbonate of soda is converted into carbonate of barytes, whilst the caustic soda, react- 
ing upon the chloride of barium, liberates a quantity of caustic barytes proportionate to that 
of the caustic soda in the soda ash. After this addition of chloride of barium, the liquor is 
filtered in order to separate the precipitated carbonate of barytes produced, and which re- 
mains on the filter, on which it should be washed with pure water. A few lumps of chalk 
are then put into a Florence flask, a, and some muriatic acid being poured upon it, an 
effervescence due to a disengagement of carbonic acid is produced, the flask is then closed 



with a good cork, provided with a bent tube, 6, reaching to the bottom of the vessel, c, and 
the stream of carbonic acid produced is then passed through the liquor, c, filtered from the 
carbonate of barytes above mentioned. The stream of car- 
bonic acid produces a precipitate of carbonate of barytes, 
which should be also collected on a separate filter, washed, 
dried, and weighed. "Each gain of this second precipitate of 
carbonate of barytes corresponds to 0-3157 of caustic soda. 

91. As the soda ash of commerce almost invariably con- 
tains earthy carbonates, the sample operated upon should 
always be dissolved in hot water, and filtered, in order to 
separate the carbonate of lime, which otherwise would saturate 
a proportionate quantity of the test acid, and thus render the 
analysis worthless. 

92. The quantity of water contained in either potash or 
soda ash is ascertained by heating a weighed quantity of the 
sample to redness in a covered platinum capsule or crucible. 
The loss after ignition indicates the proportion of water. If 

any caustic alkali is present, 1 equivalent, =9 of water, is retained, which cannot be thus 
eliminated, but which may, of course, be determined by calculation after the proportion of 
caustic soda has been found, as shown before, each 31 grains of caustic soda containing 9 
grains of water. 

93. Besides the alkalimetrical processes which have been explained in the preceding 
pages, the proportion of available alkali contained in the sample may be estimated from the 
amount of carbonic acid which can be expelled by supersaturating the alkali with an acid. 
The determination of the value of alkalis, from the quantity of carbonic acid thus evolved by 
the supersaturation of the carbonate acted upon, has long been known. Dr. Ure, in the 
"Annals of Philosophy," for October, 1817, and then in his " Dictionary of Chemistry," 
1821, and more recently in his pamphlet " Chemistry Simplified," described several instru- 
ments for analyzing earthy and alkaline carbonates, for a description of which the reader is 
referred to the article on Acidimetry. The ingenious little apparatus of Drs. Fresenius 
and Will for the same purpose, and to which we have already alluded in the same article, 
gives accurate results ; but it should be observed that when the potash or soda of commerce 
contains any caustic alkali, or bicarbonate, or earthy carbonates, or sulphuret of alkali — 
which, as we have seen, is frequently, and, indeed, almost invariably, the case, the process 
is no longer applicable without first submitting the sample to several operations — which 
render this process troublesome and unsuited to unpractised hands. Thus, if caustic potash 
is present, the sample must be first mixed and triturated with its own weight of pure quartz- 
ose sand and about one-third of its weight of carbonate of ammonia. The mass is then 
moistened with aqueous ammonia, and then put into a small iron capsule and evaporated to 
dryness," so as to expel completely the ammonia and carbonate of ammonia. The mass is 
then treated by water, filtered, washed, and concentrated to a proper bulk by evaporation, 
transferred to the apparatus, and treated as will be seen presently. If the sample contains 
caustic soda, instead of one-third, at least half of its weight of carbonate of ammonia should 
be employed. But for the estimation of pure carbonates, Drs. Fresenius and Will's method 
is both accurate and easy. The apparatus consists of two 
flasks, a and b ; the first should have a capacity of from 
two to two ounces and a half ; the second, or flask b, should 
be of a somewhat smaller size, and hold about one and a 
half or two ounces. Both should be provided with per- 
fectly sound corks, each perforated with two holes, through 
which the tubes a, c, d, are passing. The lower extremity 
of the tube a must be adjusted so as to reach nearly to 
the bottom of the flask a, and its upper extremity is closed 
by means of a small pellet of wax, 6; c is a tube bent twice 
at right angles, one end of which merely protrudes through 
the cork into the flask a, but the other end reaches nearly 
to the bottom of the flask b. The tube d of the flask b 
merely protrudes through the cork into the flask. 

94. The apparatus being so constructed, a certain quan- 
tity — 100 grains, for example — of the potash or soda ash 
under examination, (and which may have been previously 
dried,) is weighed and introduced into the flask a, and water 
is next poured into this flask to about one-third of its capacity. Into the other flask, or 
flask b, concentrated ordinary sulphuric acid is poured, and the corks are firmly put in the 
flasks, which thus become connected, so as to form a twin-apparatus, which is then car- 
ried to a delicate balance, and accurately weighed. This done, the operator removes the 
apparatus from the balance, and applying his lips to the extremity of the tube d, sucks out 


a few air-bubbles, which, as the other tube, a, is closed by the wax pellet, rarefies the air in 
the flask a, and consequently causes the sulphuric acid of flask b to ascend a certain height 
(after the suction) into the tube c ; and if, after a short time, the column of sulphuric acid 
maintains its height in the tube c, it is a proof that the apparatus is air-tight, and therefore 
as it should be. This being ascertained, suction is again applied to the extremity of the 
tube d, so that a portion of the sulphuric acid of the flask b ascends into the tube c, and 
presently falls into the flask a ; the quantity which thus passes over being, of course, pro- 
portionate to the vacuum produced by the suction. As soon as the acid thus falls in the 
water containing the alkaline carbonate in the flask a, an effervescence is immediately pro- 
duced, and as the carbonic acid disengaged must, in order to escape, pass, by the tube c, 
through the concentrated sulphuric acid of the flask b, it is thereby completely dried before 
it can finally make its exit through the tube d. The effervescence having subsided, suction 
is again applied to the tube d, in order to cause a fresh quantity of sulphuric acid to flow 
over into the flask a, as before ; and so on, till the last portion of sulphuric acid sucked 
over produces no effervescence, which indicates, of course, that all the carbonate is decom- 
posed, and that, consequently, the operation is at an end. A powerful suction is now ap- 
plied to the tube d, in order to cause a tolerably large quantity of sulphuric acid, but not 
all, to flow into the flask a, which thus becomes very hot, from the combination of the 
concentrated acid with the water, so that the carbonic acid is thereby thoroughly expelled 
from the solution. The little wax pellet which served as a stopper is now removed from 
the tube a, and suction applied for some time, in order to sweep the flasks with atmos- 
pheric air, and thus displace all the carbonic acid in the apparatus, which is allowed to 
become quite cold, and weighed again, together with the wax pellet, the difference between 
the first and the second weighing — that is to say, the loss — indicating the quantity of car- 
bonic acid which was contained in the carbonate, which has escaped, and from which, of 
course, the quantity of the carbonated alkali acted upon may be calculated. Suppose, in 
effect, that the loss is 19 grains : taking the 

Equivalent of soda =31 

do carbonic acid - - - - - = 22 

1 equivalent of carbonate of soda - = 53, 

it is clear that the 19 grains of carbonic acid which have been expelled represent 45 - 77 
grains of carbonate of soda, or, in other words, 100 grains of soda ash operated upon con- 
tained 45'77 of real carbonate of soda, thus : — 

CO 2 NaO'CO 2 CO 2 NaO 1 CO 2 

22 : 53 :: 19 : x — 45-77 , 

95. As the soda ash of commerce always contains earthy carbonates, and very frequently 
sulphui'ets, sulphites, and occasionally hyposulphites, instead of putting the 100 grains to 
be operated upon directly into the flask a, it is absolutely necessary first to dissolve them in 
boiling water, to filter the solution, and to wash the precipitate which may be left on the 
filter with boiling water. The solution and the washings being mixed together, should then 
be reduced by evaporation to a proper volume for introduction into the flask a, and the 
process is then carried on as described. If sulphuret, sulphites, or hyposulphites are 
present, the ash should be treated exactly as mentioned in §§ 83-91, previous \p pouring 
the solution into the flask a, since otherwise the sulphuretted hydrogen and sulphurous acid, 
which would be disengaged along with the carbonic acid, would apparently augment the 
proportion of the latter, and render the result quite erroneous. 

96. The balance used for this mode of analysis should be capable of indicating small 
weights when heavily laden. — A. N". 

ALKALINE EARTHS — Barytes, Lime, and Strontta. These earths are so called to 
distinguish them from the earths Magnesia and Alumina. They are soluble in water, but 
to a much less extent than the alkalies. Their solutions impart a brown color to turm'eric 
paper, and neutralize acids. They are, however, distinguished from the alkalies by their 
combination with carbonic acid, being nearly insoluble in water. 

AL-KENNA, or AL-HENNA, is the name of the root and leaves of Lawsonia incrmis, 
which have been long employed in the East to dye the nails, teeth, hair, garments, &c. 
The leaves, ground, and mixed with a little limewater, serve for dyeing the tails of horses 
in Persia and Turkey. 

It is the same as the herb Henna frequently referred to by the Oriental poets. The 
powder of the leaves, being wet, forms a paste, which is bound on the nails for a night, and 
the color thus given will last for several weeks. 

This plant is sometimes called the true alkanet root, the alkanet of the shops being 
termed the spurious alkanet root, (radix alkannm spurice.) 

ALLIOLE. One of the hydrocarbons which can be obtained from naphtha. It is one 
of the most volatile of bodies. Alliole is obtained by distilling crude naphtha, and collect- 



ing all that leaves the still in the first distillation before the boiling temperature reaches 
194° F ; and on the second distillation, all below 176° F. This substance combines with, 
or is altered by, oil of vitriol, and hence it is better obtained from the crude naphtha, and 
afterwards purified by agitation with dilute sulphuric or hydrochloric acid, and redistillation. 
It boils, when nearly free from benzole, at a temperature of from 140° to 158° F., and 
possesses an alliaceous odor somewhat resembling sulphide of carbon. — Richardson. > 

ALLOTROPT. AHotropie Condition. A name introduced by Berzelius to signify 
another form of the same substance, derived from &Kkos, another, and Tp6iros, habit. Car- 
bon, for example, exists as the diamond, a brilliant gem, with difficulty combustible ; as 
graphite, a dark, heavy, opaque mass, often crystalline, also of great infusibility ; and as 
charcoal, a dark porous body, which burns with facility. 

An extensive series of bodies appears to assume similar allotropic modifications. The 
probability is that, with the advance of physical and chemical science, many of the 
substances now supposed to be elementary will be proved to be but allotropic states of some 
one form of matter. Deville has already shown that silicon and boron exist, like the dia- 
mond, in three allotropic states — one of the conditions of boron being much harder than the 

ALLOY. The experiments of Crookewitt upon amalgams appear to prove that the 
combination of metals in alloys obeys some laws of a similar character to those which 
prevail between combining bodies in solution ; i. e. that a true combining proportion 

By amalgamation and straining through chamois leather, he obtained crystalline metallic 
compounds of gold, bismuth, lead, and cadmium, with mercury, which appeared to exist in 
true definite proportions. With potassium he obtained two amalgams, KHg 20 and KHg 5 . 
With silver, by bringing mercury in contact with a solution of nitrate of silver, according 
to the quantity of mercury employed, he obtained such amalgams as Ag 5 Hg 10 , Ag Hg 2 , 
A°" Ho* 3 A<r Ho* 4 

Beyond those there are many experiments which appear to prove that alloys are true 
chemical compounds ; but, at the same time, it is highly probable that the true chemical 
alloy is very often dissolved (mechanically disseminated) in that metal which is largely in 

Some years since, the editor carried out an extensive series of experiments in the labo- 
ratory of the Museum of Practical Geology, with the view of obtaining a good alloy for 
soldiers' medals, and the results confirmed his views respecting the laws of definite, propor- 
tional combination among the metals. Many of those alloys were struck at the Mint, and 
yielded beautiful impressions ; but there were many objections urged against the use of any 
alio)' for a medal of honor. 

The alloys of the following metals have been examined by Crookewitt, and he has given 
their specific gravities as in the following table ; the specific gravity of the unalloyed metals 
being — 

Copper - - - 8-794 I Zinc - - - 6-860 
Tin ... 7-305 Lead - - - 11-354 

That of the allovs 

wtfs — 

Cu 2 Sn 5 



Cu Pb 

- 10-375 

Cu Sn 



Sn Zn 2 


Cu 2 Sn 



Su Zn 


Cu 3 Zn 5 



Sn 3 Zn 


Cu 3 Zn 2 



Sn Pb 2 - 


Cu 2 Zn 



Sn Pb 


Cu 2 Pb 3 


-• 10-753 

Sn 3 Pb 


There are many points of great physical as well as chemical interest in connection with 
alloys, which require a closer study than they have yet received. There are some striking 
facts, brought forward by M. Wertheim, deduced from experiments carried on upon fifty- 
four binary alloys and nine ternary alloys of simple and known composition, which will be 
found in the " Journal of the French Institute," to which we would refer the reader. 


Tin 230° 

Tin, 5 atoms ; lead, 1 atom - 194° 

" 4 " " 1 " 189° 

" 3 " " 1 " 186° 

On the Melting Point of Certain Alloys 
- 334° 

Tin, 2 atoms; lead, 1 atom - 196° 


1 " 

2 vols. 


3 " 
1 vol. 

- 241° 

- 2S9° 

- 194° 

In these experiments of M. Ku'pffer, the temperatures were determined with thcrmom- 



eters of great delicacy, and the weighings were carefully carried out. — Ann. de CJiifme, xl. 
285-302 ; Brewster's Edin. Jour. Sci. i. N.S. p. 299. 

It may prove convenient to give a general statement of the more striking peculiarities 
of the important alloys. More detailed information will be found under the heads of the 
respective metals. 

Gold and Silver Allots. — The British standard for gold coin is 22 parts pure gold 
and 2 parts alloy ; and for silver, 222 parts pure silver to 18 parts of alloy. 

The alloy for the gold is an indefinite proportion of silver and copper : some coin has a 
dark red color, from the alloy being chiefly copper ; the lighter the color a larger proportion 
of silver is indicated, sometimes even (when no copper is present) it approaches to a greenish 
tinge, but the proportion of pure gold is the same in either case. 

The alloy for silver coinage is always copper ; and a very pure quality of this metal is 
used for alloying, both for the gold and silver coinage, as almost any other metal being 
present, even in very small quantities, would make the metals unfit for coinage, from ren- 
dering the gold, silver, and copper brittle, or not sufficiently malleable. 

The standard for plate (silver) is the same ■ as the coin, and requires the same quan- 
tity of copper, and carefully melting with two or three bits of charcoal on the surface 
while in fusion, to prevent the oxidation of the copper by heat and exposure to the atmos- 

The gold standard for plate and jewellery varies, by a late act of Parliament, from the 
22 carats pure, to 18, 12, and 9 : the alloys are gold and silver, in various proportions, 
according to the taste of the workmen ; the color of the articles manufactured depending, as 
with the coin, on the proportions ; if no copper is used in qualities under 22 carats fine 
gold, the color varies from a soft green to a greenish white, but a proportion of copper may 
be used so as to bring the color to nearly that of 22 fine, 1 silver, and 1 copper. 

Wire of either gold or silver may be drawn of any quality; but the ordinary wire, for 
fine purposes, such as lace, contains from 5 to 9 pennyweights of copper in the pound of 240 
pennyweights, to render it not so soft as it would be with pure silver. 

Gold, silver, and copper, may be mixed in any proportions without injury to the ductil- 
ity, but no reliable 'scale of tenacity appears to have been constructed, although gold and 
silver in almost any proportions may be drawn to the very finest wire. 

The alloys of silver and palladium may be made in any proportions ; it has been found 
that even 3 per cent, of palladium prevents silver tarnishing so soon as without it ; 10 per 
cent, very considerably protects the silver, and 30 per cent, of palladium will prevent the 
silver being affected by fumes of sulphuretted hydrogen unless very long exposed : the latter 
alloy has been found useful for dental purposes, and the alloy with less proportions — say 10 
to 15 per cent. — has been used for graduated scales of mathematical instruments. 

The alloy of platinum and silver is made for the same purposes as those of palladium, 
and, by proper care in fusion, are nearly equally useful, but the platinum does not seem to 
so perfectly combine with the silver as the palladium. Any proportion of palladium with 
gold injures the color, and even 1 per cent, may be detected by sight, and 5 per cent, ren- 
ders it a silver color, while about 10 per cent, destroys it ; but the ductility of the alloy is 
not much injured. 

Gold leaf for gilding contains from 3 to 12 grains of alloy to the ounce. Sixteen- 
carat gold, which is f fine gold and i alloy, the alloy being nearly always equal portions of 
silver and copper, is not in the slightest degree injurious for dentists' purposes. 

Antimony in the proportion of -j-gVjf quite destroys the ductility of gold. 

Gold and platinum alloy forms a somewhat elastic metal. Hermstadt's imitation of 
gold consists of 16 parts of platinum, V parts of copper, and 1 of zinc, put in a crucible, 
covered with charcoal powder, and melted into a mass.-rP. J. 

Dentists' amalgam is prepared by rubbing together, in a mortar, or even in the hollow 
of the hand, finely divided silver and mercury, and then pressing out all the uncombined 
mercury. This alloy, when put into the hollow of a decayed tooth, very soon becomes 
exceedingly hard. Some dentists add a little copper, or gold, or platinum leaf, under the 
impression that the amalgam becomes harder. 

Copper Allots. — Copper alloyed with zinc forms Brass, and with tin, we have 
Bronze. (See those articles.) The alloys of the ancients were usually either brasses or 
bronzes. The following analyses of ancient coins, &c., by Mr John Arthur Phillips, are of 
great value. 

It is not a little curious to find that some of the coins of high antiquity contain zinc, 
which does not appear to have been known as a metal before 1280 a.d., when Albertus 
Magnus speaks of zinc as a semi-metal, and calls the alloy of copper and zinc golden marea- 
site ; or rather, perhaps, he means to apply that name to zinc, from its power of imparting a 
golden color to copper. The probability is that calamine was known from the earliest times 
as a peculiar earth, although it was not thought to be an ore of zinc or of any other metal. 
■ — See Watson's Chcmieal Essays. 












B. c. 

A. D. 



















Semis - - - - 










Quadrans - - - 










Hiero I. - - - 






Alexander the Great - 








Philippus III. 



9 43 

Philippus V. 


So 15 






Copper coin of Athens 










Egyptian, Ptolemy IX. 






. — , 





Pompey, First Brass - 



S-47 16-15 


Coin. of the Atilia Family 



4-86 25-43 



— • 



Julius and Augustus - 


. — 


8-00 12-81 




Augustus and Agrippa 








Large Brass of the Cas- ) 
sia Family - ) 

















Broken sword-blade 



10-02 i — 


Fragment of sword-blade 



S-17 I — 





Broken spear-head 



[ — 





Celt .... 



7-43 ! 1-28 





Celt --- - 



9-81 I — 


Celt .... 



9-19 ! — 






Celt --- - 



10-79 ( 3-20 







Large Brass of Nero 

. — 






Titus - 







Hadrian ... 

— . 







Faustina, Jun. 

— . 



4 97 




Greek Imperial Samosata 




6-75 ! 21-96 


Victorinus, Sen. (No. 1) 




•99 trace 



• 1-00 

Victorinus, Sen. (No. 2) 




■10 i trace 




Tetrius, Sen. (No. 1) - 




•37 trace 




Tetrius, Sen. (No. 2) - 




■51 1 — 




Claudius Gothicus (No. 1) 


J- 268 


7-41 [ 8 11 




Claudius Gothicus (No. 2) 




2 67 




Tacitus (No. 1) - 


J- 275 







■ Tacitus (No. 2) - 






Probus (No. 1) - 





2 33 




Probus (No. 2) - 


•45 [ -45 





Copper, when united with half its weight of lead, forms an inferior alloy, resembling 
gun-metal in color, but is softer and cheaper. This alloy is called pot-metal and cock-metal, 
because it is used for large measures and in the manufacture of tap-cocks of all de- 

Sometimes a small quantity of zinc is added to pot-metal ; but when this is considerable, 
the copper seizes the zinc to form brass, and leaves the lead at liberty, a large portion of . 
which separates on cooling. Zinc and lead are not disposed to unite ; but a little arsenic 
occasions them to combine. 

Of the alloys of copper and lead, Mr. Holtzapffel gives the following description : — 

Lead Allots. — Two ounces lead to one pound copper produce a red-colored and duc- 
tile alloy. 

Four ounces lead to one pound copper give an alloy less red and ductile. Neither of 
these is so much used as the following, as the object is to employ as much lead as possible. 
_ Six ounces lead to one pound copper is the ordinary pot-metal, called dry pot-metal, as 
this quantity of lead will be taken up without separating on cooling ; this alloy is brittle 
when warmed. 

Seven ounces lead to one pound copper form an alloy which is rather short, or disposed 
to break. 

Eight ounces lead to one pound copper is an inferior pot-metal, called wet pot-metal, as 
the lead partly oozes out in cooling, especially when the new metals are mixed ; it is there- 
fore always usual to fill the crucible in part with old metal, and to add new for the remain- 
der. This alloy is very brittle when slightly warmed. More lead can scarcely be used, as 
it separates on cooling. 

Antimony twenty parts and lead eighty parts form 'the printing-type of France ; and 
lead and antimony are united in various proportions to form the type-metal of our printers. 
See Type. 

Mr. James Nasmyth, in a letter to the " Athenaeum," (No. 1176, p. 511,) directed atten- 
tion to the employment of lead, and its fitness as a substitute for all works of art hitherto 
executed in bronze or marble. He says the addition of about 5 per cent, of antimony to 
the lead will give it, not only great hardness, but ejihance its capability to run into the most 
delicate details of the work. 

Baron Wetterstedt's patent sheathing for ships consists of lead, with 2 to 8 per cent, of 
antimony ; about 3 per cent, is the usual quantity. The alloy is rolled out into sheets. — 
Holtzapffel. We are not aware that this alloy has ever been employed. 



Emery wheels and grinding tools for the lapidary are formed of an alloy of antimony and 

Organ pipes are sometimes made of lead and tin, the latter metal being employed to 
harden the lead. The pipes, however, of the great organ in the Town Hall of Birmingham 
are principally made of sheet zinc. 

Lead and arsenic form shot-metal. The usual proportions are said to be 40 lbs. of 
metallic arsenic to one ton of lead. 

Tabular Statement of the Physical Peculiarities of the Principal Alloys, adopted, with 
some alterations, from the "Encyclopedic Technologique.'" 





With Zinc, rendering it 

This alloy is very brittle. 



With Iron and Steel, hard- 

30 of iron and 70 of anti- 


ending, whitening, and 

mony are fusible ; very 

rendering those metals 

hard, and white. An 

susceptible of a fine pol- 

alloy of two of iron and 

ish : much used for steel 

one of antimony is very 

chains and other orna- 

hard and brilliant. 


With Gold, a gray metal, 

Forms readily a pale-yellow 

Similar to antimony; of a 

very brittle. 

alloy, breaking with a 
fracture like porcelain. 

yellow-green color. 

With Copper. Composed 

Alloys readily : the alloys 

Pale-red brittle metal. 

of 62 parts of copper 

are brittle. Those form- 


and 32 arsenic, a gray, 

ed with equal parts of 

brilliant, brittle metal. 

the two metals are of a 

Increasing the quantity 

fine violet color. 

of copper, the alloy be- 

comes white and slightly 

ductile : used in the man- 

ufacture of buttons un- 

der the name of white 

copper, or Tombac. 

With Silver. 23 of silver 

These have a strong affini- 

Alloys brittle and lamel- 

and 14 of arsenic form 

ty ; their alloys are al- 


a grayish-white brittle 

ways brittle. 


With Lead. Arsenic ren- 

Antimony gives hardness 

The alloys of bismuth and 

ders lead brittle. The 

to lead. 24 parts of an- 

lead are less brittle and 

combination is very inti- 

timony and 76 of lead, 

more ductile than those 

mate; not decomposed 

•corresponding to Pb 2 Sb, 

with antimony; but the 

by heat.i 

appear the point of satu- 

alloy of 3 parts of lead 

ration of the two metals. 

and 2 of bismuth is 
harder than lead. These 
alloys are very fusible. 

With Tin. Brittle, gray, 

The alloys of antimony and 

Tin and bismuth unite in 

lamellated ; less fusible 

tin are very white. They 

all proportions by fusion. 

than tin. 

become brittle when the 

All the alloys are more 

arsenic is in large quan- 

fusible than tin. 


With Mercury. Without 

A gritty white alloy. 

Mercury dissolves a large 


quantity of bismuth with- 
out losing its fluidity ; 
but drops of the alloy 
elongate, and form a tail. 





With Zinc. See 
Galvanized Iron. 

With Iron or Steel, 

With Gold ■ 

With Copper 


A greenish-yellow 
alloy, which will 
take a fine polish. 

Gold and iron alloy 
with ease, and 
form yellowish al- 
loys, varying in 
color with the 
proportions of the 
metals. Three or 
four parts of iron 
united with one of 
gold is very hard, 
and is used in 
the manufacture 
of cutting instru- 


See Brass. 

Iron and copper do 
not form true al- 
loys. When fused 
together, the iron, 
however, retains 
a little copper. — 
Several methods 
for coating iron 
with copper and 
brass will be de- 

Copper and gold al- 
loy in all propor- 
tions, the copper 
giving hardness to 
the gold. This al- 
loy is much used 
in coin and in the 
metal employed in 
the manufacture 
of jewellery. 

With Lead, does 
not appear to 
form any alloy. 

With Tin. Avery 
little iron dimin- 
ishes the mallea- 
bility of tin, and 
gives it hardness. 

With Mercury. 
Mercury has no 
action on iron. 

A very brittle alloy. 
A thousandth pt. 
of lead is sufficient 
to alter the duc- 
tility of gold. 

The alloys of gold 
and tin are brit- 
tle ; theypreserve, 
however, some 
ductility when the 
proportion of tin 
does not exceed JL. 

Mercury has a most 
powerful action on 
gold. See Amal- 

Do not appear to 
form a true alloy. 

Of great importance. 
See Bronze. 

An amalgam which 
is formed with dif- 
ficulty, and with- 
out interest. 


Silver and zinc com- 
bine easily, form- 
ing a somewhat 
brittle alloy. 

When 1 of silver 
and 500 of steel 
are fused, a very 
perfect button is 
formed. — Stodart 
and Faraday. 

Gold and silver mix 
easily together ; 
but they do not 
appear to form a 
true combination. 
Jewellers often 
employ For vert, 
which is composed 
of 10 parts of gold 
and 30 of silver, 
which corresponds 
very nearly to the 
alloy possessing 
the maximum 

Silver and copper 
alloy in all pro- 
portions. These al- 
loys are much used 
in the arts. The 
maximum . hard- 
ness appears to be 
produced when 
the alloy contains 
a fifth of copper. 

Unite in all propor- 
tions ; but a very 
small quantity of 
lead will greatly 
diminish the duc- 
tility of silver. 

Alloys readily. A 
very small quan- 
tity of tin destroys 

• the ductility of 

The amalgamation of 
these two metals 
is a little less ener- 
getic than between 
mercury and gold. 
See Amalgama- 



In addition to these, the alloys of iron appear of sufficient importance to require some 
further notice. 

Iron and Manganese. — Mr. Mushet concludes, from his experiments, that the maximum 
combination of manganese and iron is 40 of the former to 100 of the latter. The alloy 
7T4 of tin and 28 - 6 of manganese is indifferent to the magnet. 

Iron and Silver ; Steel and Silver. — Various experiments have been made upon alloys 
of iron and steel with other metals. The only alloys to which sufficient importance has been 
given are those of iron and silver and steel and silver. M. Guyton states, in the " Annales 
de Chimie," that he found iron to alloy with silver in greater quantity than the silver with 
the iron. " Iron can," he says, " therefore no longer be said to refuse to mix with silver ; 
it must, on the contrary, be acknowledged that those two metals, brought into perfect 
fusion, contract an actual chemical union ; that whilst cooling, the heaviest metal separates 
for the greatest part ; that, notwithstanding each of the two metals retains a portion of the 
other, as is the case in every liquidation, the part that remains is not simply mixed or inter- 
laid, but chemically united ; lastly, the alloy in these proportions possesses peculiar 
properties, particularly a degree of hardness that may render it extremely useful for various 

The experiments of Faraday and Stodart on the alloys of iron and steel are of great 
value ; the most interesting being the alloy with silver. The words of these experimen- 
talists are quoted : — 

" In making the silver alloys, the proportion first tried was 1 silver to 1G0 steel ; the re- 
sulting buttons were uniformly steel and silver in fibres, the silver being likewise given out 
in globules during solidifying, and adhering to the surface of the fused buttons ; some of 
these, when forged, gave out more globules of silver. In this state of^mechanical mixture 
the little bars, when exposed to a damp atmosphere, evidently produced voltaic aotion ; and 
to this we are disposed to attribute the rapid destruction of the metal by oxidation, no such 
destructive action taking place when the two metals are chemically combined. These 
results indicated the necessity of diminishing the quantity of silver, and 1 silver to 200 steel 
was tried. Here, again, were fibres and globules in abundance ; with 1 to 300 the fibres 
diminished, but still were present ; they were detected even when 1 to 400 was used. The 
successful experiment remains to be named. When 1 of silver to 500 steel were properly 
fused, a very perfect button was produced ; no silver appeared on its surface ; when forged 
and dissected by an acid, no fibres were seen, although examined by a high magnifying 
power. The specimen forged remarkably well, although very hard ; it had in every respect 
the most favorable appearance. By a delicate test every part of the bar gave silver. This 
alloy is decidedly superior to the very best steel ; and this excellence is unquestionably 
owing to a combination with a minute quantity of silver. It has been repeatedly made, and 
always with equal success. Various cutting tools have been made from it of the best qual- 
ity. This alloy is, perhaps, only "inferior to that of steel and rhodium, and it may be 
procured at small expense ; the value of silver, where the proportion is so small, is not worth 
naming ; it will probably be applied to many important purposes in the arts." 

Messrs. Faraday and Stodart show from their researches that not only, silver, but plati- 
num rhodium, gold, nickel, copper, and even tin, have an affinity for steel sufficiently 
strong to make them combine chemically. 

Iron and Nickel unite in all proportions, producing soft and tenacious alloys. Some 
few vears since, Mr. Nasmyth drew attention to the combination of silicon with steel. Fresh 
interest has been excited in this direction by the investigations of a French chemist, M. St. 
Claire Deville, who has examined many of the alloys of silicon. 

Silicon and Iron combine to form an alloy which is a sort of fusible steel in which car- 
bon is replaced by silicon. The siliciurets are all of them quite homogeneous, and are not 
capable of being separated by liquidation. 

Copper and Silicon unite in various proportions, according to the same chemist. A 
very hard, brittle, and white alloy, containing 12 per cent, of silicon, is obtained by melting 
together three parts silico-fluoride of potassium, one part sodium, and one part of copper, 
1 at such a temperature that the fused mass remains covered with a very liquid scoria. The 
copper takes up the whole of the silicon, and remains as a white substance less fusible than 
silicon, which may serve as a base for other alloys. An alloy with 5 per cent, silicon has a 
beautiful bronze color, and will probably receive important applications. 

Mr. Oxland and Mr. Truran have given, in " Metals and their Alloys," the following use- 
ful tabular view of the composition of the alloys of copper. 

The principal alloys of copper with other metals are as follows : — 









Antique bronze sword 


. . 


" springs 


- - 


Bronze for statues 




- - 



" for medals 




" for cannon 




" for cymbals 


- . 


" for gilding 




- - 



tt cc 




- - 



Speculum metal 


- - 


Brass for sbeet - 



Gilding metal - 



; Pinchbeck ... 



Prince's metal - 



tc cc 



Dutch metal - - 



English wire 




. - 



Mosaic gold ... 



Gun metal for bearings, stocks, &c. 




Muntz's metal - 



Good yellow brass 



Babbitt's metal for bushing 


- - 


- - 


Bell metal for large bells 


- - 


Britannia metal 




- - 


Nickel silver, English 



- - 


" " Parisian 



- - 


German silver ... 



- - 


ALLOY, NATIVE. Osmium and Iridium, in the proportions of 72 - 9 of the former and 
24-5 of the latter. See Osmium, Iridium. 

ALLSPICE. Pimento, or Jamaica pepper, so called because its flavor is thought to 
comprehend the flavor of cinnamon, cloves, and nutmegs. The tree producing this spice 
{Eugenia pimento) is cultivated in Jamaica in what are called Pimento walks. It is im- 
ported in bags, almost entirely from Jamaica. 

ALMOND. (Amande, Fr. ; Mandclus, Germ. ; Amygdal communis.') De Candolle 
admits five varieties of this species. A. amara, bitter almond ; A. dulcis, sweet almond ; 
A. fragilis, tender-shelled almond; A. macrocarpa, large-fruited almond; A. persicoides, 
peach almond. 

Three varieties are known in commerce : 

1. Jordan Almonds, which are the finest, come from Malaga. Of these there are two 
kinds : the one above an inch in length, flat, with a clear brown cuticle, sweet, mucilagi- 
nous, and rather tough ; the other more plump and pointed at one end, brittle, but equally 
sweet with the former. 

2. Valentia Almonds are about three-eighths of an inch broad, not quite an inch long, round 
at one end, and obtusely pointed at the other, flat, of a dingy brown color, and dusty cuticle. 

3. Barbary and Italian almonds resemble the latter, but are generally smaller and less 
flattened. — Brande, Dictionary of Pharmacy. 

ALMOND OIL. A bland fixed oil, obtained by expression from either bitter or sweet 
almonds ; usually from the former, on account of their cheapness as well as the greater 
value of the residual cake. The average produce is from 48 to 52 lbs. from 1 cwt. of 
almonds. — Pereira. 

ALMOND POWDER (farina amygdala;) is the ground almond cake, and is employed 
as a cake for washing the hands, and as a lute. 

ALOE. (Aloes, Fr. ; Glauindes aloe, Germ.) In botany a genus of the class JJexan- 
dria monogynia. There are many species, all natives of warm climates. 

In Africa the leaves of the Guinea aloe are made into durable ropes. Of one species are 
made lines, bow-strjngs, stockings, and hammocks ; the leaves of another species are used 
to hold rain water. 

A patent has been taken (January 27th, 1847) for certain applications of aloes to dyeing. 
Although it has not been employed, the coloring matter so obtained promising to be very 
permanent and intense, it is thought advisable to describe the process by which it is pro- 
posed to prepare the dye. It is as follows : 

Into a boiler or vessel capable of holding about 100 gallons, the patentee puts 10 gallons 
of water, and 132 lbs. of aloes, and heats the same until the aloes are dissolved; he then 
adds 80 lbs. of nitric or nitrous acid in small proportions at a time, to prevent the discn- 
Vol. III.— 5 


gageruent of such a quantity of nitrous gas as would throw part of the contents out of the 
boiler. When the whole of the acid has been introduced, and the disengagement of gas has 
ceased, 10 lbs. of liquid caustic soda, or potash of commerce, of about 30°, are added to 
neutralize any undecomposed acid remaining in the mixture, and to facilitate the use of the 
mixture in dyeing and printing. If the coloring matter is required to be in a dry state, the 
mixture may be incorporated with 100 lbs. of china clay and dried in stones, or by means 
of a current of air. The coloring matter is used in dyeing by dissolving a sufficient quan- 
tity in water, according to the shade required, and adding as much hydrochloric acid or tar- 
tar of commerce as will neutralize the alkali contained in the mixture, and leave the dye 
bath slightly acidulated. The articles to be dyed are introduced into the bath, which is 
kept boiling until the desired shade is obtained. 

When the coloring matter is to be used in printing, a sufficient quantity is to be dis- 
solved in water, according to the shade required to be produced ; this solution is to be 
thickened with gum, or other common thickening agent, and hydrochloric acid, or tartar of 
commerce, or any other suitable supersalt, is to be added thereto. After the fabrics have 
been printed with the coloring matter, they should be subjected to the ordinary process of 
steaming, to fix the color. — Napier. 

Aloetic acid, on which the coloring matter of the aloes depends, has been examined by 
Schunck and Mulder. Aloetic acid is deposited, from nitric acid which has been heated with 
aloes, as a yellow powder ; it dissolves in ammonia with a violet color ; when treated with 
protochloride of tin, it forms a dark-violet heavy powder ; and this, again, when treated 
with potash, evolves ammonia, and assumes a violet-blue color. The solution of aloetic acid 
in ammonia is violet. 

ALPACA. (Alpaga, Fr.) An animal of Peru, of the Llama species; also the name 
given to a woollen fabric woven from the wool of this animal. 

ALUM. (Alun, Fr. ; Alaun, Germ.) A saline body or salt, consisting of alumina, or 
the peculiar earth of clay, united with sulphuric acid, and these again united with sulphate 
of potash or ammonia. In other words, it is a double salt, consisting of sulphate of alumina 
and sulphate of potash, or sulphate of alumina and sulphate of ammonia. The common 
alum crystallizes in octahedrons, but there is a kind which takes the form of cubes. It has 
a sour or rather subacid taste, and is peculiarly astringent. It reddens the blue color of 
litmus or red cabbage, and acts like an acid on many substances. Other alkalies may take 
the place of the ammonia or potash, and other metals that of the aluminium. 

The composition of alum is expressed by chemists in the following manner : APO 3 3S0 3 
KOSO 3 24HO. This peculiar combination is that of the original substance as far as it 
appeared to the chemists of last century, and the form is now held as a type, after which 
many other alums are composed. Ammonia-alum was occasionally made, even as early as 
Agricola's time, 16th century. Its composition is APO 3 3S0 3 NH 4 0S0 3 + 24HO. The 
same thing occurs with soda ; soda alum is APO 3 3S0 3 NaOSO 3 -j- 24HO. Every salt hav- 
ing this form is called an alum. Sometimes, instead of the alkali being changed, the earth 
is changed. Thus we have chrome-alum, Cr 2 3 3S0 3 KOSO 3 + 24HO ; or we have an iron- 
alum, Fe 2 O 3 3S0 3 KOSO 3 -f- 24HO. These may be varied to a great extent, but all have a 
characteristic of alum. The twenty-four atoms of water are one of the peculiar characteristics. 

Composition of pure Potash Alum. 

Per Cent. Per Cent. 

Potash - - 9-89 or 1 atom 47 1 / , , * c . , , o^ i 4 nn 

A1 . 1n „, ., , ,, .„ / I Sulphate of potash - 1S-32 or 1 atom 27 

Alumina - 10'94 1 52 l , ' r. ± c i ■ „^ m u ■, « i to 

a - i • -a on no u a ci iXn r or ■{ Sulphate of alumina 36-21 " 1 " 172 

Sulphuric acid 33-68 " 4 " 160 [ J W A„ ,,..<, ,, ■■ a «, 1R 

Water- -45-49 "24 " 216 ) I Water " " ' 45 48 X 216 
Its specific gravity is 1-724. 

100 parts of water dissolve, at 32 degrees Fahrenheit, 3-29 alum. 

" " 50 " " 9-52 " 

" " " 86 " " 22-01 " 

*t it u 199 (< u 30*92 " 

" " " 158 " " 90-67 " 

11 11 11 212 " " 357-48 " 

These Tables of Poggiale should be re-examined, and gradations made more useful 
for this country. 

Solubility. — 1 part of crystallized potash alum is soluble — 

At 54 degrees Fahrenheit in 13'3 water. 
" 70 " " 8-2 " 

11 ^ 11 •• 4 . 3 ■• 

" 100 " " 2-2 " 

11 J22 <•' " 2"0 " 

" 145 " " 0-4 " 

" 167 " " 0-1 " 

" 189-5 " " 0-06 " 

ALUM. 67 

A solution saturated at 46° is l - 045 specific gravity. This difference in the rate of solu- 
bility in hot and cold water renders it easily separated from many other salts. The crystals 
are permanent in the air, or nearly so, unless the air be very dry ; if kept at 180° they lose 
18 atoms of water, but alum deprived of its water and exposed to the air of summer took 
up 18 atoms in 4V days. It melts at a low temperature in its water of crystallization. At 
356° it loses 43 - 5 per cent, of water, or 23 atoms; the last atom is only lost when ap- 
proaching red heat. At a red heat the sulphate of alumina loses its acid, and the alumina 
seems then able to remove some acid from the potash, losing it again by heat. Alum, when 
heated with common salt, acts like sulphuric acid, and gives off muriatic acid ; the same 
with chlorides of potassium and ammonium. If boiled with a saturated solution of chloride 
of potassium, hydrochloric acid is formed and a subsulphate of alumina falls down ; this 
occurs only to a small extent with chloride of sodium, and still less with sal-ammoniac. 

Applications of Alum. — Alum is an astringent. Its immediate effect on man is to 
corrugate the fibres and contract the small vessels. It precipitates albuminous liquids and 
combines with gelatine. It causes dryness of the mouth and throat, and checks the secre- 
tions of the alimenary canal, producing constipation ; in large quantities, nausea, vomiting, 
purging. It is given in lead colic, to convert the lead into sulphate of lead, and used 
externally. Its principal use is in dyeing ; calico-printers print it as a mordant, the cloth is 
then put into the dye, and the printed parts absorb the color. Paper-makers use it in their 
size and bookbinders in their paste. It is used in tanning leather, and sometimes, both in 
Asia and Europe, it is used for precipitating rapidly the impurities of water. This is a 
dangerous process, unless there be a great amount of alkaline salts, such as carbonate of 
lime or soda to neutralize the acid. It is extensively used in correcting the baking qualities 
of bad flour, for which the experience of many has decided that it is a valuable remedy ; 
unfortunately, it is also used to make excellent flour whiter, when there is no need of its 
presence. Liebig says that lime is equally good, and of course much safer. From time 
immemorial it has been used to prevent the combustibility of wood and cloth. 

Alum heated with charcoal or carbonaceous substances forms Homberg's phosphorus, 
which inflames spontaneously. It is composed of alumina, sulphide of potassium, and 

Burnt Alum, or dried alum, is made by gently heating alum till the water is driven off. 
The alum first melts in its water of crystallization and is then dried. It has a stronger 
action than the hydrated crystals, and is a mild escharotic. It reabsorbs water. 

Ammonia-alum readily loses all its ammonia when heated, and the sulphuric acid may 
be driven off the remaining sulphate of alumina, so that the pure earth-alumina will remain. 

Neutral Alum is a name sometimes given erroneously to alum which has had some of its 
acid neutralized by an alkali. It is, in fact, a basic salt of alumina, which may also be made 
by dissolving alumina in ordinary alum. It deposits a basic salt more readily than ordinary 
alum, and may be of service in some cases of printing. Properly speaking, the common alum 
is the neutral salt. 

Testing of Alum. — Alum being generally in large crystals, any impurity is more readily 
seen ; this is said to be the reason for keeping up the practice of making this substance 
instead of the sulphate of alumina alone, which is less bulky and fitted for nearly every 
purpose for which alum is used. But probably the ancient accidental discovery of the pot- 
ash form has determined its use to the present day. Iron is readily found in it, by adding 
to a dilute solution ferrocyanide of potassium or prussiate of potash, which throws down 
Prussian blue. A very delicate test is sulphuret of ammonium, which throws down both 
the alumina and iron, but the blacking of the precipitate depends on the amount of iron. 
The total amount of iron is got by adding pure caustic potash or soda till the solution is 
strongly alkaline, washing and filtering off the oxide. To look for lime, precipitate the 
alumina and iron by ammonia, boil and filter, the lime and magnesia are in the solution, 
add oxalate of ammonia ; add tartaric acid to keep up the iron and alumina, make alkaline 
by ammonia, then precipitate the lime by oxalate of ammonia, filter, and precipitate the 
magnesia by a phosphate. Silica and insoluble basic sulphates are obtained by simply dis- 
solving the alum in water and filtering. If silica, it is insoluble in acids ; if a basic sulphate, 
it will dissolve in sulphuric acid, and the addition of sulphate of potash or ammonia will 
convert it into potash or ammonia-alum. 

Its formula, according to Graham, is a basic alum, HO SO 3 + 3(AP0 3 S0 3 ) + 9HO. 
By losing alumina it becomes the neutral salt. 

Sulphate of Alumina. — The first step towards the production of alum is the sulphate of 
alumina. This is found in various proportions in alum stone. The pure mineral has the 
following composition : — 

1 atom of alumina - - 15 - 42 per cent. 
3 atoms of sulphuric acid - 35'99 " 
18 atoms of water - - 48"59 " 




There are many analyses of natural specimens closely approaching this. It is found crys- 
tallized in a close mass of fine, white, flexible needles, of a feather or hair form, and has 
been, like a few other substances, called hair-salt. It is also found with various degrees of 
impurity, sometimes with a smaller amount of water. Knapp has collected the following 
list of analyses : — 

Analyses of Natural Sulphate of Alumina or Feather Alum. 




H. Rose. 

„... , Ber- 
Gobel. 1 


Th. TrjompBon. 




1 1 
3 a 

1 1 

o ^ 




'C e 
o tc 
be =! 




•a "H 



of iron 

of iron 


Potash - 



Silica - 
Water - 







































+Ss> 3 2-78 

41-5 14-645 
- - 0-500 

3-5 0-100 











o t4 

a g 



100 00J99 010 



100-00 100-23s'9S-432 

1 ' 

100-000' 10011 




The manufacture of alum involves the making of sulphate of alumina in the first 
instance in all cases where potash is not present in the ore ; for this reason the description 
of both is included in one article. 

Ores or Raw Material. — The chief difficulty in manufacturing alum has been the solu- 
tion of the alumina. This substance is generally combined with silica in such a strong com- 
bination that even powerful acids cannot remove it without assistance. The older methods, 
however^ took no notice of these difficulties, and obtained the alum more or less directly 
from nature. The method now practised at the Solfatara di Pozzuoli and the island Vul- 
cano is simply to take the efflorescence and the earth containing it, wash it with water, and 
concentrate. But it very seldom contains a sufficient amount of potash to form alum. A 
salt of potash is then added, chiefly a carbonate. To transform this into a sulphate, a por- 
tion of the sulphate of alumina is decomposed. The use of a carbonate is a wasteful method 
of modern times ; the ancients would have felt no difficulty, but boiled all down, and so 
obtained the whole alumina there. Their product, therefore, would have been basic sul- 
phate of alumina, which it evidently was when this practice was resorted to. When they 
merely concentrated and then crystallized, they got pure alum ; but they lost a great deal 
of their alumina. 

At Tolfa the alum is obtained from a compact crystalline substance called alunite. The 
analysis of Cordier makes it a combination of alum with alumina. If treated with water 
only, it will not give out alum ; but if moderately calcined, it breaks up, gives out a large 
amount of alum, and the liquid is then boiled down for crystallization. 

Here are specimens of the ore, two of which contain a considerable amount of potash. 
As there is seldom enough of potash found, it must be added in the form of sulphate of 
potash or chloride of potassium. 

Sulphuric acid - 36"187 - 34-6 - 20-06 

Alumina - - 35-105 - 40-0 • Z^O 

Potash - - 10-824 - 15-8 Lime 0-30 

Water - - 18-124 - 10-6 - 59-94 




These formations of alum are generally found where sulphurous gases are exhaled : the 
rock is gradually decomposed. 


It is not, however, found so rich in the great majority of cases, 
yses of some alum stones : — 

The following are anal- 



Desootil. Cordier. 

Alum Stone. 

Alum Stone. 


Mont d'Or. 

Silica - - 

Alumina ----- 
Sulphuric acid - - - - 
Potash ----- 


Oxide of iron ... - 




















When there is no silica, but only sulphuric acid, alumina, and potash, we have a natural 
alum, and in that case there is nothing to be done towards the manufacture. But it rarely 
happens that the constituents exist in a proportion to form the crystalline salt There may 
be sulphate of alumina, hydrate of alumina, and some true alum, or sulphate of alumina and 
potash. This excess of hydrate of alumina forms, when united with the sulphate, a basie 
or insoluble sulphate of alumina, and nothing but the sulphate of potash becomes solubla 
When the hydrate is heated, the water escapes ; the sulphate of alumina and potash are 
then capable of being washed out together, and alum is obtained. At Tolfa it is obtained 
in crystals, covered over with a light red powder of peroxide of iron. This reddish covering 
always accompanies the Roman or partly cubical alum, and it has been sometimes added in 
order to give common alum the appearance of the Roman. 

As the principal difficulty in the manufacture of alum is the solution of the alumina, it 
is unfortunate that so much of the hydrate is destroyed, as in the process mentioned, when 
sulphuric acid would readily dissolve it and greatly increase the produce. By the method 
described to us, the measure of alum is simply the amount of the potash. All that cannot 
find potash to unite with is lost. 

Occasionally ammonia-alum is found in nature. Analyses have been made of specimens 
from Tschermig, in Bohemia, by Stromeyer : — 







Sulphuric acid 


Water - - - 



Sulphate of alumina - 
Sulphate of ammonia - 
Sulphate of magnesia - 
Water - 






Soda-alum is also found naturally. 

Alum from Peru, by T. Thomson. 
Sulphate of soda - - - - - - - - - 6-50 

Sulphuric acid 
Water - 



From the Andes. 

Sulphuric acid -------.- 36-199 

Alumina ---- 11-511 

Soda ----------- 7-259 

Water 43-819 

Silica , . - . 0-180 

Lime 0-255 

Peroxide of iron --------- 0-199 

Protoxide of iron - - - - - - - . - 0-760 


Messrs. Richardson and Ronalds have given some very minute analyses of the Whitby 
and Campsie shales. 



Sulphur ... 

Iron ... - 

Sulphuret of iron 

Silica - - - - 

Protoxide of iron 

Alumina ... 

Lime - 


Oxide of manganese - 

Sulphuric acid 


Soda - 


Carbon and loss - 


Coal - - 

Loss --- - 

Water ... 


Top Eock. 
















Top Eock. 








Top Eock, 












As the Top one contains a larger excess of iron pyrites than the Bottom, they are 
mixed so as to diffuse the sulphuric acid equally. 

Erdmann has thus analyzed his German specimens : — 



Soluble in acid. 
Insoluble in acid. - 

'Sulphuret of iron .... 

Silica ------- 

Peroxide of iron 

Alumina ----.. 



'Silica ------- 

Alumina ------ 

Peroxide of iron 

Magnesia ------ 










Other shales will be found of interest ; the following are by G. Kersten : — 

Carbonaoeous matter 
Silica ... 
Peroxide of iron 
Alumina - - - 

Sulphur - - - 
Oxide of manganese 
Sulphate of lime 
























ALUM. 71 

Shales from Freienwalde, 


rom Puzbero, 

bv Klaproth. 

by Bergemann. 

Alumina - - - 16-000 




Silica - - - 40-00 


. ■ . 


Magnesia - - - - 25 



Sulphur - - - 2-85 



3 94 

Carbon - - - 19-65 




Protoxide of iron - 6-40 




Oxide of manganese - 




Sulphate of protoxide of iron 1-80 




" " alumina 




" " lime 1-50 




" " potash 1-50 




Chloride of potassium 0*50 




Sulphuric acid 




Water - - - 10-75 




101-20 99-70 

Here the sulphur has evidently existed in combination with iron, which has been united 
to oxygen by the analysts. The amount of sulphate shows a partial disintegration and 
other changes. 

Lampadius gives another with much more sulphur : — 

Alum Shale from SieJtda. 

Sulphate of alumina, - 2-68 

Potash-alum, 0-47 

Sulphate of iron, 0-95 

Sulphate of lime, 1-70 

Silica, 10-32 

Alumina, 9 - 21 

Magnesia, - traces 

Oxide of iron, 2-30 

Oxide of manganese, - - - - - - - - - 0-31 

Sulphur, 7-13 

Water, 33-90 

Carbon, 31-03 


When alum is made of such shale, the object is first of all to oxidize the sulphur, form- 
ing sulphuric acid. This acid then dissolves the alumina. The result may be accomplished 
by allowing the shale to disintegrate spontaneously in the air, the sulphur oxidizing and dis- 
solving the alumina. But in general, as at Whitby and Campsie, combustion must be 
resorted to. This can be accomplished without the use of coal, further than is needful sim- 
ply to set fire to that portion which exists in the shale itself. Indeed, the Campsie one, 
having more coal than is desirable for slow combustion, is mixed with some spent material, 
in order to diminish the force of the heat. 

The sulphur is united with the iron, forming a bisulphuret, each atom of which must 
therefore take up seven atoms of oxygen, FeS"-j-70=Fe0 S0 3 -f-S0 3 . When combustion 
takes place, the sulphur oxidizes ; if rapid combustion is used, then sulphurous acid gas 
escapes ; if slow combustion, the sulphurous acid penetrates the mass slowly, receives 
another atom of oxygen, unites to a base, and a sulphate is the consequence. Sulphate of 
iron is formed and pure sulphuric acid. In the process it is probable that the oxidation is 
completed by means of the iron. Protoxide of iron readily becomes peroxide ; the sul- 
phurousjicid readily decomposes peroxide, forming sulphuric acid and protoxide of iron. 
This protoxide of iron is again converted into peroxide, and if not dissolved is rendered, to 
a great extent, difficult to dissolve, by reason of the heat of the mass. For this reason, 
partly, there is less sulphate of iron in the alum than might be expected. To effect these 
changes it is desirable to burn very slowly, so as to allow no loss of sulphurous acid, and, in 
washing, to allow the water to stand a long time on the burnt ore. Another method, by 
which the sulphuric acid is transferred to the alumina, is the peroxidation of the protoxide 
in the sulphate of iron ; acid is by this means set free and begins to act on the alumina. 

The protosulphate of iron being formed, it is removed by boiling down the liquor until 
the protosulphate of iron crystallizes out, at the same time the solution becoming saturated 
with the aluminous salt. The sulphate of iron is soluble in 0-3 of hot water, the alum in 
0-06. The liquid around the crystals on the remaining mother liquor contains iron also ; 
this is washed off by adding pure liquors. 



The presence of lime or magnesia in the ores is, of course, a means of abstracting acid, 
preventing the alumina being dissolved, and even precipitating it when dissolved. 

Knapp says that at Salzweiler, near Duttweiler, in Rhenish Prussia, the roasting of the 
ore takes place in the pit or mine. The stratum of brown coal which lies under it havinn- 
been accidentally set fire to in 1660, has smouldered till the present time without inter- 

When the ores are roasted, one-half of the sulphur is freed and sent into the mass or 
escapes as sulphurous acid ; and the remaining, protosulphuret of iron, is afterwards con- 
verted into green vitriol. 

After calcining and washing the Campsie ores, the residue had the following compo- 
sition : — 

Silica, 38-40 

Alumina, 12-'70 

Peroxide of iron, 20-80 

Oxide of manganese, traces. 

Lime, 2-0'7 

Magnesia, ----- 2-00 

Potash, 1-00 

Sulphuric acid, lO-'ze 

Water, 12-27 


It is, therefore, very far from being a complete process ; but it is not considered profitable 
to remove the whole of the alumina. In some places the exhausted ore is burnt a second 
time with fresh ore, as at Campsie, but we are not told the estimated exhaustion. 

In preparing alum from clay or shale, it is of infinite importance that so much and no 
more heat be applied to the clay or shale, in the first instance, as will expel the water of 
combination without inducing contraction. A temperature of 600° F. is well adapted to 
effect this object, provided it be maintained for a sufficient period. When this has been 
carefully done, the silicate of alumina remaining is easily enough acted upon by sulphuric 
acid, either slightly diluted or of the ordinary commercial strength. The best form of 
apparatus is a leaden boiler, divided into two parts by a perforated septum or partition, also 
in lead ; though on a very large scale, brickwork set in clay might be employed. Into one 
of the compartments the roasted clay or shale should be put, and diluted sulphuric acid 
being added, the bottom of the other compartment may be exposed to the action of a well- 
regulated fire, or, what is better, heated by means of steam through the agency of a coil of 
leaden pipe. In this way a circulation of the fluid takes place throughout the mass of 
shale ; and, as the alumina dissolves, the dense fluid it produces, falling continually towards 
the bottom of the boiler, is replaced by dilute acid, which, becoming in its turn saturated, 
falls like the first ; and so on in succession, until either the whole of the alumina is taken 
up, or the acid in great part neutralized. The solution of sulphate of alumina thus ob- 
tained is sometimes evaporated to dryness, and sold under the name " concentrated alum ;" 
but more generally it is boiled down until of the specific gravity of about l - 35 ; then one 
or other of the carbonates or sulphates of potash or ammonia, or chloride of either base, or 
a mixture of these, is added to the boiling fluid, and as soon as the solution is complete, the 
whole is run out into a cooler to crystallize. The rough alum thus made is sometimes puri- 
fied by a subsequent recrystallization, after which it is " roched " for the market — a process 
intended merely to give it the ordinary commercial aspect, but of no real value in a chemi- 
cal point of view. 

The manufacture of alum is now taking an entirely new shape, and the two processes 
of Mr. Spence and Mr. Pochin threaten to absorb the whole of the manufacture in the 

Mr. Spence, who has a manufactory of ammonia-alum at Manchester, called the Pendle- 
ton Alum Works, and another at Goole, in Yorkshire, has now become the largest maker 
of this substance in the world, as his regular production amounts to upwards of 100 tons 
per week. In this process, which he has patented, he uses for the production of his sul- 
phate-of-alumina solution the carbonaceous shale of the coal measure. This substance con- 
tains from 5 to 10 per cent, of carbonaceous matter, and, when ignited by a small quantity 
of burning coal, the combustion continues of itself. To insure this the shale is spread into 
long heaps not exceeding 18 inches in height, and having a brick drain running along each 
to supply air ; in this manner it slowly calcines : this process must be so conducted as not 
to vitrify the shale. After calcination it is boiled and digested in large leaden pans, heated 
by fire, with sulphuric acid of 1-4 specific gravity. After 30 to 40 hours of digestion the 
sulphate of alumina formed is run into another leaden pan, and the boiling vapor from the 
ammonia liquor of the gas works is passed into it, until so much alumina is combined with 
the solution as to form ammonia-alum. The solution is then run into shallow leaden cool- 


ers, and the alum crystallizes. It is then purified and washed much in the usual way, only 
that the process is conducted so as to cause much less labor than at other alum works. 

Alum Cake. — This substance owes its value to the amount of sulphate of alumina it 
contains, and is in fact another means of making soluble alumina accessible. We have 
already seen the many attempts to obtain alumina from clay, and the tedious nature of the 
operation of solution in acid, as well as the long after-processes of lixiviation and conver- 
sion into sulphate of alumina, or into alum, by reboiling or crystallizing. Mr. Pochin, of 
Manchester, has found a method of removing all the difficulties, both of the first and after- 
processes. He uses very fine China clay, free from iron, heats it in a furnace, mixes it 
thoroughly with acid, and finds that, when the process is managed carefully, the combina- 
tion of the alumina and sulphuric acid is not only complete, but so violent that he is obliged 
to dilute his acid considerably, in order to calm the action. When mixed, it is passed into 
cisterns with movable sides, where, in a few minutes, it heats violently and boils. The 
thick liquid gradually becomes thicker, until it is converted into a solid porous mass — the 
pores being made by the bubbles of steam which rise in the mass, which is not fluid enough 
to contract to its original volume. The porous mass is perfectly dry, although retaining a 
large amount of combined water. It retains, of course, all the silica of the original clay, 
but this is in such fine division that every particle appears homogeneous. The silica gives 
it a dryness to the touch not easily gained by the sulphate only. 

When pure sulphate of alumina is wanted in solution, the silica is allowed to precipitate 
before using it, but, in many cases, the fine silica is no hindrance ; then the solution is 
made use of at once. — R. A. S. 

ALUMINA. (A1 2 3 , 51 - 4.) This is the only oxide which the metal aluminium forms, 
and it is assumed to be a sesquioxide on account of its isomorphism with sesquioxide of iron. 

The occurrence of alumina in the native state has been before mentioned, and the sev- 
eral minerals will be found described elsewhere. 

It is obtained in the state of hydrate from common alum (KO, SO 3 ; APO 3 , SSO 3 -)- 
24HO) by adding a solution of ammonia (or better, carbonate of ammonia) to the latter 
salt, and boiling. The precipitate is white, and gelatinous in a high degree, and retains the 
salts, in the presence of which it has been formed, with remarkable pertinacity, so that it is 
very difficult to wash. • 

By drying and igniting this hydrate, the anhydrous alumina is produced ; but it may be 
obtained more- readily by heating ammonia-alum, (NH 4 0, SO 3 ; Al-O 3 3S0 3 + 24HO.) 
All the constituents of this salt are volatile, with the exception of the alumina. It is 
insoluble in water, but soluble both in acids and alkalies. Towards the former it plaj'S the 
part of a base, producing the ordinary alumina salts ; whilst, with the latter, it also enters 
into combination, but in this case it is an acid, forming a series of compounds which may 
be called aluminates. 

The important application of alumina and its compounds in the arts of dyeing and calico- 
printing, depends upon a peculiar attraction which it possesses for organic bodies. This 
affinity is so strong, that when digested in solutions of vegetable coloring matters, the 
alumina combines with and carries down the coloring matter, removing it entirely from the 
solution. Pigments thus obtained, which are combinations of alumina with the vegetable 
coloring matters, are called " lakes." 

Alumina has not only an affinity for the coloring matters, but at the same time also for 
the vegetable fibres, cotton, silk, wool, &c. ; and hence, if alumina be precipitated upon 
cloth in the presence of a coloring matter, a most intimate union is effected between the 
cloth and the color. Alumina, when employed in this way, is called a " mordant." 

Other bodies have a similar attraction for coloring matters, e. g. binoxide of tin and 
sesquioxide of iron : each of these gives its peculiar shade to the color or combination, 
alumina changing it least. 

Soluble Modification of Alumina — Mr. Walter Crum* has discovered a peculiar soluble 
modification of alumina. The biacetate of alumina has been found by Mr. Crum to possess 
the very curious property of parting with its acetic acid until the whole is expelled, by the 
long-continued application of heat to a solution of this salt ; the alumina remains in the 
solution in a soluble allotropic condition. Its coagulum with dyewoods is translucent, and 
entirely different from the opaque cakes formed by ordinary alumina ; hence this solution 
cannot act as a mordant. But this solution of alumina, which is perfectly colorless and 
transparent, has the alumina separated from it by the slightest causes. A minute quantity 
of either an acid, an alkali, even of a neutral salt, or of a vegetable coloring matter, effects 
the change. The precipitated alumina is insolublo in acids, even boiling sulphuric ; this 
shows another allotropic condition. But it is dissolved by caustic alkalies, by which it is 
restored to its common state. — H. M. W. 

ALUMINA, ACETATE OF. The acetates of alumina are extensively used in the arts 
on account of the property which they possess of being readily decomposed with deposition 
of their alumina on the fibre of cloth ; hence they are used as mordants, in the manner dc- 
* Chemical Society's Quarterly Journal, vi. 216. 


scribed under Calico Printing ; and sometimes in dyeing they are mixed with the solution 
of a coloring matter ; in this the textile fabric is immersed, whilst, on heating, the alumina 
is precipitated upon the fabric, which, in consequence of its affinities before alluded to, car- 
ries down the coloring matter with it, and fixes it on the cloth. 

The acetate of alumina thus employed is obtained by treating sulphate of alumina with 
neutral acetate of lead, and filtering oft" the solution from the precipitate of sulphate of 
lead. Acetate of lime is also used ; but the sulphate in this case does not leave the solu- 
tion so clear or so rapidly. 

According to Mr. Walter Crura,* the solution resulting from the decomposition of sul- 
phate of alumina (APO 3 , 3S0 3 ) by monobasic acetate of lead contains the salt Al-O 3 , 
2C 4 H 3 3 , (biacetate of alumina,) together with one equivalent of free acetic acid, the com- 
pound APO 3 , 3CH 3 3 not appearing to exist. By evaporating this solution at low tem- 
peratures, e. g. in a very thin layer of fluid below 38° C, (100° F.,) Crum obtained a fixed 
residue completely soluble in water, the composition of which, in the dry state, approached 
APO 3 , 2C 4 H 3 3 -HHO.— H. M. W. 

ALUMINA, SILICATES OF. Silicate of alumina is the chief constituent of common 
clay, {which see ;) it occurs also associated with the silicates of iron, magnesia, lime, and 
the alkalies in a great variety of minerals, which will be found described elsewhere. The 
most interesting of these are the felspars and the zeolites. See Clay. 

Of course, being present in clay, silicate of alumina is the essential constituent of por- 
celain and earthenware. See Porcelain. — H. M. W. 

ALUMINA, SULPHATE OF. The neutral sulphate of alumina, APO 3 , 3S0 3 + 18HO, 
which is obtained by dissolving alumina in sulphuric acid, crystallizes in needles and plates ; 
but sulphuric acid and alumina combine in other proportions, e. g. a salt of the formula 
APO 3 , 3S0 3 -|-AP0 3 was obtained by Mons, and the solution of this salt, when largely 
diluted with water, splits into the neutral sulphate and an insoluble powder containing 
APO 3 , 3S0 3 -f- 2AP0 3 -f 9HO. This subsalt forms the mineral aluminite, found near 
Newhaven, and was found by Humboldt in the schists of the Andes. 

The sulphate of alumina is now extensively used in the arts instead of alum, under the 
name of " concentrated alum." For most of the purposes for which alum is employed, the 
sulphate of potash is an unnecessary constituent, being only added in order to facilitate the 
purification of the compound from iron ; for in consequence of the ready crystallizability 
of alum, this salt is easily purified. Nevertheless, Wiesmann has succeeded in removing 
the iron from the crude solution of sulphate of alumina obtained by treating clay with sul- 
phuric acid, by adding ferrocyanidc of potassium, which throws down the iron as Prussian 
blue ; the solution, when evaporated to dryness, is found to consist of sulphate of alumina, 
containing about 7 per cent, of potash-alum. 1,500 tons of this article were produced at 
Newcastle-on-Tyne alone in the year 1854. See also Alum. — H. M. "W. 

ALUMINIUM. (Si/7)i. Al., equiv. 13 - 7.) The name Aluminium is derived from the 
Latin alumen, for alum, of which salt this metal is the notable constituent. 

The following is the method described by M. Deville for the preparation of this interest- 
ing metal : — 

Having obtained the chloride of aluminium, he introduces into a wide glass (or porce- 
lain) tube 200 or 300 grammes of this salt between two plugs of asbestos, (or in a boat of 
porcelain or even copper,) allows a current of hydrogen to pass from the generator through 
a desiccating bottle containing sulphuric acid and tubes containing chloride of calcium, and 
finally through the tube containing the chloride ; at the same time applying a gentle heat to 
the chloride, to drive off any free hydrochloric acid which might be formed by the action of 
the air upon it. He now introduces at the other extremity of the tube a porcelain boat 
containing sodium ; and when the sodium is fused the chloride of aluminium is heated, 
until its vapor comes in contact with the fused sodium. A powerful reaction ensues, con- 
siderable heat is evolved, and by continuing to pass the vapor of the chloride over the 
sodium until the latter is all consumed, a mass is obtained in the boat of the double chloride 
of aluminium and sodium, (NaCl, APCP,) in which globules of the newly reduced metal 
are suspended. It is allowed to cool in the hydrogen, and then the mass is treated with 
water, in which the double chloride is soluble, the globules of metal being unacted upon. 

These small globules are finally fused together in a porcelain crucible, by heating them 
strongly under the fused double chloride of aluminium and sodium, or even under com- 
mon salt. 

This process, which succeeds without much difficulty on a small scale, is performed far 
more successfully as a manufacturing operation. Two cast-iron cylinders are now employed 
instead of the glass or porcelain tube, the anterior one of which contains the chloride of 
aluminium, whilst in the posterior one is placed the sodium in a tray, about 10 lbs. being 
employed in a single operation. A smaller iron cylinder intermediate between the two for- 
mer is filled with scraps of iron, which serve to separate iron from the vapor of chloride of 

* Chemical Society's Quarterly Journal, vi. 216. 


aluminium, by converting the perchloride of iron into the much less volatile protochloride. 
They also separate free hydrochloric acid and chloride of sulphur. 

During the progress of the operation the connecting tube is kept at a temperature of 
about 400 J to 600° F. ; but both the cylinders are but very gently heated, since the chloride 
of aluminium is volatile at a comparatively low temperature, and the reaction between it 
and the sodium when once commenced generates so much heat that frequently no external 
aid is required. 

Preparation of Aluminium by Electrolysis. — Mr. Gore has succeeded in obtaining 
plates of copper coated with aluminium by the electrolysis of solutions of chloride of 
aluminium, acetate of alumina, and even common alum ;* but the unalloyed metal cannot 
be obtained by the electrolysis of solutions. Deville, however, produced it in considerable 
quantities by the method originally suggested by Bunsen, viz., by the electrolysis of the 
fused double chloride of aluminium and sodium, (NaF, A1 2 F 3 ;) but since this process is 
far more troublesome and expensive than its reduction by sodium, it has been altogether 

Preparation of Aluminium from Kryolite. — So early as March SO, 1855, a specimen 
of aluminium was exhibited at one of the Friday evening meetings of the Royal Institu- 
tion, which had been obtained in Dr. Percy's laboratory by Mr. Allan Dick, by a process 
entirely different from that of Deville, which promised, on account of its great simplicity, 
to supersede all others, f It consisted in heating small pieces of sodium, placed in alter- 
nate layers with powdered kryolite, a mineral now found in considerable abundance in 
Greenland, which is a double fluoride of aluminium and sodium, analogous to the double 
chloride of aluminium and sodium, its formula being NaF, Al' 2 F 3 . The process has the 
advantage that one of the materials is furnished ready formed by nature. 

The experiment was only performed on a small scale by Mr. Dick in a platinum crucible 
lined with magnesia ; the small globules of metal, which were obtained at the bottom of 
the mass of fused salt, being subsequently fused together under chloride of potassium or 
common salt. 

Before the description of these experiments was published, M. Rose, of Berlin, pub- 
lished a paper in September, 1855, on the same subject.:): In Rose's experiments he em- 
ployed cast-iron crucibles, in which were heated ten parts of a mixture of equal weights of 
kryolite and chloride of potassium with 2 parts of sodium. The aluminium was obtained in 
small globules, which were fused together under chloride of potassium, as in Mr. Dick's 

Rose experienced a slight loss of aluminium by fusion under chloride of potassium, and 
found it more advantageous to perform this fusion under a stratum of the double chloride 
of aluminium and sodium, as Deville had done. 

He never succeeded in extracting the whole quantity of aluminium present in the kryo- 
lite, (13 per cent.,) chiefly on account of the ready oxidizability of the metal when existing 
in a very finely divided state, as some of it invariably does. 

It does not appear that any attempt has since been made to obtain aluminium on the 
large scale from kryolite, probably from the supply of the mineral not proving so abundant 
as was at one time anticipated. 

In all the processes which have been found practicable on any considerable scale, for the 
manufacture of aluminium, the powerful affinities of sodium are employed for the purpose 
of eliminating it from its compounds. The problem of the diminution of the price of 
aluminium therefore resolves itself into the improvement of the methods for procuring 
sodium, so as to diminish the cost of the latter metal. M. Deville's attention was therefore 
directed, in the early steps of the inquiry, to this point ; and very considerable improve- 
ments have been made by him, which will be found fully described under the head of 

Devilleg has since suggested the employment at once of the double salt of chloride of 
aluminium and chloride of sodium, (NaCl, APC1 3 ,) instead of the simple chloride of 
aluminium, so as to obtain the metal by means of sodium. He uses 400 parts of this 
double salt, 200 of common salt, 200 of fluor spar, and 75 to 80 of sodium. The above- 
mentioned salts are dried, powdered, and mixed together ; then with these the sodium, in 
small pieces, is mixed, and the whole heated in a crucible under a layer of common salt. 
After the reaction is complete, the heat is raised so as to promote the separation of the 
aluminium in the form of a button. It was found, however, that kryolite was, with advan- 
tage, substituted for the fluor spar. 

C. Brunner|| employs artificially prepared fluoride of aluminium ; but this method can- 
not offer any advantage over the employment of the chloride, which is cheaper, or the 
kryolite, which nature affords. 

Properties. — The metal is white, but with a bluish tinge ; and even when pure has a 
lustre far inferior to silver. 

* Phil. Mag. vii. 20T. t Phil. Mag. x. 364. J Poggendorf, Annalen, and Phil. Mag. s. 2S3. 

§ Ann. de Chim. et Phys. slvi. 415. || Chouiical Gazette, 1S56, 83S. 


Specific gravity, 2-56, and, when hammered, 2-67. 

Conducts electricity eight times better than iron, and is feebly magnetic. 

Its fusing point is between the melting points of zinc and silver. 

By electrolysis it is obtained in forms which Deville believes to be regular octahedra ; 
but Rose, who has also occasionally obtained aluminium in a crystalline state, (from kryo- 
lite,) denies that they belong to the regular system. 

When pure, it is unoxidized even in moist air ; but most of the commercial specimens 
(probably from impurities present in the metal) become covered with a bluish-gray tarnish. 
It is unaffected by cold or boiling water ; even steam at a red heat is but slowly decomposed 
by it. _ 

It is not acted upon by cold nitric acid, and only very slowly dissolved even by the boil- 
ing acid ; scarcely attacked by dilute sulphuric acid, but readily dissolved by hydrochloric 
acid, with evolution of hydrogen. 

Sulphuretted hydrogen and sulphides have no action upon it ; and it is not even attacked 
by fused hydrated alkalies. Professor Wheatstone* has shown that in the voltaic series, 
aluminium, although having so small an atomic number, and so low a specific gravity, is 
more electro-negative than zinc ; but it is positive to cadmium, tin, lead, iron, copper, and 

Impurities in Aluminium. — Many of the discrepancies in the properties of aluminium, 
as obtained by different experimenters, are due to the impurities which are present in it. 

If the naphtha be not carefully removed from the sodium, the aluminium is liable to 
contain carbon. 

Frequently, in preparing aluminium, by the action of the chloride on sodium, by De- 
ville's original process, copper boats have been used for holding the sodium ; in this case 
the metal becomes contaminated, not only with copper, but also with any other metal which 
may be present in the copper — e. g. Salm-Horstmar \ found copper in the aluminium sold 
in Paris, and Erdmann detected zinc ; \ and in every case the metal is very liable to become 
mixed with silicon, either from the earthenware tubes, boats, or crucibles; hence Salvetat 
found, even in the aluminium prepared by Deville himself, 2-87 per cent, of silicon, 2-40 
of iron, 6-38 of copper, and traces of lead. 

The following analysis of commercial aluminium was communicated to the British Asso- 
ciation, at its meeting in 1857, by Professor Mallet : — 

Made in Paris. Made in Berlin. 

Al 92-969 96-253 

Fe - - - - - 4-882 3-293 

Si 2-149 0-454 

Ti trace trace 

100-00 100-00 

Alloys of Aluminium. — Very small quantities of other metals suffice to destroy the 
malleability and ductility of aluminium. An alloy containing only -J^ of iron or copper 
cannot be worked, and the presence of -jL copper renders it as brittle as glass. Silver 
and gold produce brittleness in a less degree. An alloy of 5 parts of silver with 100 of 
aluminium, is capable of being worked like the pure metal, but it is harder, and therefore 
susceptible of a finer polish ; whilst the alloy, containing 10 per cent, of gold, is softer, 
but, nevertheless, not so malleable as the pure metal. The presence of even -pj-^- part of 
bismuth renders aluminium brittle in a high degree. 

These statements by Tissier,§ however, require confirmation ; for Debray states that 
aluminium remains malleable and tough when containing as much as 8 per cent, of iron, or 
10 per cent, of copper, but that a larger quantity of either of these metals renders it 

It is curious that only 3 per cent, of silver are sufficient to give aluminium the bril- 
liance and color of pure silver, over which the alloy has the great advantage of not being 
blackened by sulphuretted hydrogen. 

On the other hand, small quantities of aluminium combined with other metals change 
their properties in a remarkable manner. Thus copper alloyed with only J ff of its weight 
of aluminium has the color and brilliance of gold, and is still very malleable, (Tissier ;) and 
when the aluminium amounts only to V 5 , (i. e. 20 per cent.,) the alloy is quite white, 

An alloy of 90 parts of copper and 10 of aluminium is harder than common bronze, 
and is capable of being worked at high temperatures easier than the best varieties of iron. 
Larger quantities of aluminium render the metal harder and brittle. — Debray. || 

An alloy of 100 parts of silver with 5 of aluminium is as hard as the alloy employed in 

* Phil. Mag. x. 143. t Journal pr. Chem. lxvii. 493. 

t Journal pr. Chem. lxvii. 494. § C. and J. Tissier, Comptes Rendus, xliii. 8S5. 

|| Comptes Iteudus, xliii, 925. 


the silver coinage, although the other properties of the silver remain unchanged, (Tissier.) 
Similar alloys have likewise been prepared by Dr. Percy.* 

Messrs. Calvert and Johnson describef an alloy of 25 parts aluminium to 75 of iron, 
which has the valuable property of not oxidizing by exposure to moist air. 

Uses of Aluminium. — No very important application of aluminium has yet been made, 
although, at the time M. Deville's experiments were commenced, sanguine hopes were 
entertained that aluminium might be produced at a price sufficiently low to admit of its 
practical application on a large scale, these anticipations have not been realized ; and as yet, 
on account chiefly of its high price,! tne applications which have been made of this inter- 
esting metal are but few. 

Its low specific gravity, combined with sufficient tenacity, recommends it for many 
interesting uses. The fractional weights used by chemists, which are made of platinum, 
are so extremely small that they are constantly being lost ; their much greater volume in 
aluminium renders this metal peculiarly suitable. In the construction of the beams of bal- 
ances, strength combined with lightness are desiderata ; and M. Deville has had very beau- 
tiful balance beams made of this metal ; but at present its high price has prevented their 
extensive adoption. 

These same qualities render this metal suitable for the construction of helmets and other 
armor ; but at present these are but curiosities, and are likely to remain so, unless some 
cheaper method of eliminating the metal than by the agency of sodium be discovered. 

Its quality of being unacted upon by oxygen, sulphuretted hydrogen, and many acids, 
would suggest numerous applications, if it were sufficiently cheap ; e. g. it might be used 
for coating other metals, as iron, lead, &c, to protect them from rust, instead of paint. § 
It would be particularly useful for covering the pipes and cisterns employed in water supply, 
and thus preventing the accidents which are constantly resulting from the action of water 
on lead. 

This metal has been proposed for making spoons, &c., instead of silver. It certainly 
has the advantage of not being blackened by sulphuretted hydrogen ; but those which the 
writer has seen have a dull leaden hue, — far inferior, even, to somewhat tarnished silver in 
brilliance, — and would certainly not be held in high esteem by the public. 

It has been suggested to employ aluminium, on account of its sonorousness and duc- 
tility, for making piano-forte wires. It was also imagined that it might be used in making 
bells ; but Mr. Denison has quite set this question at rest. No one who heard the sound 
of his aluminium bell will again think of such an application. 

Probably one of the most interesting of the applications of aluminium (at least in a 
scientific point of view) that has been made, is the recent one by Deville and Wohler, of 
employing it in the production of crystalline allotropic modifications of certain other ele- 
ments hitherto unknown in that state ; e. g. boron, silicon, and titanium, {which see.) It 
depends upon the fact that these elements, in the amorphous state, dissolve in fused alumin- 
ium, and, on cooling the molten solution, they slowly separate from the aluminium in the 
crystalline state. 

Our first importation of aluminium was in 1856, to the value of £35. — H. M. W. 

ALUMINIUM, CHLORIDE OF, (APC1 3 — 133-9.) Preparation.— Chloride of alumin- 
ium cannot be prepared by treating alumina with hydrochloric acid, as in the case of most 
chlorides ; for on evaporating the solution to dryness, hydrochloric acid is evolved and 
alumina alone remains. 

The method at present used is, in principle, the same as that originally suggested by 
ffirsted, which has since found numerous other applications. It is impossible to convert 
alumina into the chloride by the direct action of chlorine alone ; at any temperature the 
chlorine is as incapable of displacing the oxygen from the alumina as it would from lime. 
But if the attraction of the chlorine for the metal be supported by the affinity of carbon 
for the oxygen, then the compound is, as it were, torn asunder, carbonic acid or carbonic 
oxide resulting on the one hand, and the chloride of aluminium on the other. 

On the large scale the chlorine is passed over a previously ignited mixture of clay and 
coal tar, contained in retorts like those used in the manufacture of coal gas, which are 
heated in a furnace ; the chloride, which on account of its volatility is carried off, being 
condensed in a chamber lined with plates of earthenware, where it is deposited in a crystal- 
line mass. 

Properties. — It is a yellowish crystalline solid, readily decomposed by the moisture of 
the air into hydrochloric acid and alumina, volatile at a dull red heat. It is very soluble in 
water, but cannot be recovered by evaporating the solution. — H. M. W. 

ALUM, NATIVE. This term includes several compounds of sulphate of alumina with 
the sulphate of some other base, as magnesia, potash, soda, the protoxides of iron, manga- 

* Proceedings of the Royal Institution, March 14, 1S56. t Phil. Mas. x. 245. 

X The present price of Aluminium in London is 5s. per ounce, whilst only in March, 1S56, just after 
M. Deville's experiments had been made, it cost SI. per ounce. 

§ It is calculated thatmoro than a million sterling is annually expended i:i the metropolis on tho 
paint necessary to protect the iron-work from decay. — Rev. J. Harlow. 





- 64-0 by Klaproft. 


- 73.3 " Heyer. 


- 72 - 5 " Cordier. 


nese, &c. They occur generally as efflorescences, or in fibrous masses ; when crystallized, 
they assume octahedral forms. 

Native alum is soluble in water, and has an astringent taste, like that of the alum of 
commerce. — H. W. B. 

ALUM SHALE. The chief natural source from which the alum of commerce is de- 
rived in this country. It occurs in a remarkable manner near Whitby, in Yorkshire, and 
at Hurlet and Campsie, near Glasgow. A full description of the alum shale, and of the 
processes by which the crystallizable alum is separated, will be found under Alum. 

AMALGAM. When mercury is alloyed with any metal, the compound is called an 
amalgam of that metal ; as for example, an amalgam of tin, bismuth, &c. 

Some amalgams are solids and others fluids ; the former are often crystalline, and the 
latter may be probably regarded as the solid amalgam dissolved in mercury. 

Silver Amalgam may be formed by mixing finely-divided silver with mercury. The 
best process is to precipitate silver from its solution by copper, when we obtain it in a state 
of fine powder, and then to mix it with the mercury. 

A native amalgam of mercury and silver occurs in fine crystals in the mines of the 
Palatinate of Moschellandsberg : it is said to be found where the veins of copper and silver 
intersect each other. Dana reports its existence in Hungary and Sweden, at Allemont, in 
Dauphine ; Almaden, in Spain, and in Chili ; and he quotes the following analyses : — 


Allemont, - 

If six parts of a saturated solution of nitrate of silver with two parts of a saturated 
solution of the protonitrate of mercury are mixed with an amalgam of silver one part and 
mercury seven, the solution is speedily filled with beautiful arborescent crystals — the Arbor 
Diance, the tree of Diana, — or the silver tree. 

Gold Amalgam is made by heating together mercury with grains of gold, or gold-foil ; 
when the amalgam of gold is heated, the mercury is volatilized and the gold left. This 
amalgam is employed in the process known as that of fire-gilding, although, since electro- 
gilding has been introduced, it is not so frequently employed. A gold amalgam is obtained 
from the platinum region of Columbia ; and it has been reported from California, especially 
from near Mariposa. Schneider give its composition, mercury, 57"40; gold, 38 - 89 ; sil- 
ver, 5 - 0. 

Tin Amalgam. — By bringing tin-foU and mercury together, this amalgam is formed, 
and is used for silvering looking-glasses. (See Silvering Glass.) If melted tin and mer- 
cury are brought together in the proportion of three parts mercury and one part tin, the 
tin amalgam is obtained in cubic crystals. 

Electric Machine Amalgam. — Melt equal parts of tin and zinc together, and combine 
these with three parts of mercury : the mass must be shaken until it is cold ; the whole is 
then rubbed down with a small quantity of lard, to give it the proper consistence. 

Amalgam Copper, for stopping teeth. The French dentists have long made use of this 
for stopping teeth. It is sold in small rolls of about a drachm and a half in weight ; it is 
covered with a grayish tarnish, has a hardness much greater than that of bone, and its 
cohesion and solidity are considerable. When heated nearly to the point of boiling water 
this amalgam swells up, drops of mercury exuding, which disappear again on the cooling of 
the substance. If a piece, thus heated, be rubbed up in a mortar, a plastic mouldable mass, 
like poor clay, is obtained, the consistence of which may, by continued kneading, be 
increased to that of fat clay. If the moulded mass be left for ten or twelve hours, it 
hardens, acquiring again its former properties, without altering its specific gravity. Hence, 
the stopping, after it has hardened, remains tightly fixed in the hollow of the tooth. The 
softening and hardening may be repeated many times with the same sample. Pettenkofer 
ascribes these phenomena to a state of amorphism, with which the amalgam passes from 
the crystalline condition in the process of softening. All copper amalgams containing be- 
tween 0-25 to 0-30 of copper exhibit the same behavior. The above chemist recommends 
as the best mode of preparing this amalgam, that a crystalline paste of sulphate of sub- 
oxide of mercury (prepared by dissolving mercury in hydrated sulphuric acid at a gentle 
heat) be saturated under water at a temperature of from 60° to 70°, with finely divided 
reguline copper, (prepared by precipitation from sulphate of copper with iron.) One por- 
tion of the copper precipitates the mercury, with formation of sulphate of copper ; the 
other portion yields with mercury an amalgam : 100 parts of dissolved mercury require the 
copper precipitated, by iron, from 232 - 5 parts of sulphate of copper. As in dissolving the 
mercury the protoxide is easily formed instead of the suboxide, particularly if too high a 
temperature be maintained, it is advisable, in order to avoid an excess of mercury in the 
amalgam, to take 223 parts of sulphate of copper, and to add to the washed amalgam, 
which is kept stirred, a quantity of mercury in minute portions, corresponding to the 


amount of suboxide contained in the mercury salt, until the whole has become sufficiently 
plastic. This amalgam may be obtained by moistening finely-divided copper with a few 
drops of a solution of nitrate of suboxide of mercury, and then triturating the metal with 
mercury in a warmed mortar. The rubbing may be continued for some time, and may be 
carriedon under hot water, mercury being added until the required consistence is attained. 

A remarkable depression of temperature during the combination of amalgams has been 
observed by several chemists. 

Dobereiner states that when 816 grains of amalgam of lead (404 mercury and 412 lead) 
were mixed, at a temperature of 68°, with 688 grains of the amalgam of bismuth, (404 
mercury and 2S4 bismuth,) the temperature suddenly fell to 30°, and by the addition of 808 
grains of mercury (also at 68') it became as low as 17° ; the total depression amounting 
to 51°. 

In certain proportions of mixture of the constituents of fusible metal (tin, lead, and 
bismuth) with mercury, Dobereiner formed surprising depressions of temperature ; the tem- 
perature, he records of one experiment, sank instantly from 65° to 14°. 

AMBER VARNISH. Amber is composed of a mixture of two resins, which are soluble 
in alcohol and ether, and in some of the recently-discovered hydro-carbon compounds. 
Varnishes are therefore prepared with them, and sold under the name of amber spirit var- 
nishes ; but these are frequently composed of either copal or mastic. They have been 
much used for varnishing collodion pictures. 

AMBERGRIS. It is found on various parts of the east coast of Africa, as well as in the 
eastern seas. The best is ash-colored, with yellow or blackish veins or spots, scarcely any 
taste, and very little smell unless heated or much handled, when it yields an agreeable odor. 
Exposed in a silver spoon it melts without bubble or scum, and on the heated point of a 
knife it vaporizes completely away. 

The chemical composition of ambergris is represented by the following formula, 
C 33 H 32 0. True ambergris is very rarely met with, by far the largest proportion of that 
which is sold as ambergris being a preparation scented with civet or musk. 

In France the duty upon ambergris is 62 francs per kilogramme when imported in 
French vessels, and 67 francs when imported in foreign vessels. 

Ambergris is at this time (1858) worth 16s. an ounce in England. Mr. Temple, of 
Belize, British Honduras, speaks of an odorous substance thrown off by the alligator, which 
appears to resemble ambergris. 

AMETHYST. (Amethyste occidentale, Fr. ; Eisenkeisel, Germ.) One of the vitreous 
varieties of quartz, composed of pure silica in the insoluble state — that is, it will not dis- 
solve in a potash solution. It belongs to the rhombohedral system, and is found either in 
groups of crystals or lining the interior of geodes and pebbles. It is infusible before the 
blowpipe, and is not affected by acids. It is of a clear purple or bluish-violet tint ; but the 
color is frequently irregularly diffused, and gradually fades into white. The color is sup- 
posed to be due to the presence of a small percentage of manganese, but Heintz attributes 
it to a compound of iron and soda. The amethyst, from the beauty of its color, has always 
been esteemed and used in jewellery. It was one of the stones called by the ancients 'dfieBvcr- 
ros, a name which they conferred on it from its supposed power of preserving the wearer 
from intoxication. The most beautiful specimens are procured from India, Ceylon, and 
Persia, where they occur in geodes and pebbles : it is also found at Oberstein, in Sax- 
ony ; in the Palatinate ; in Transylvania ; near Cork, and in the Island of May, in Ireland. 
— H. W. B. 

AMETHYST, ORIENTAL. (Amethyste orientale, Fr. ; Demanthspath, Germ.) This 
term is applied to those varieties of corundum which are of a violet color. See Corundum. 
— H. W. B. 

AMIANTHUS is the name given to the whiter and more delicate varieties of asbestus, 
which possess a satin-like lustre, in consequence of the greater separation of the fibres of 
which they are composed. A variety of amianthus (the amianthoide of Haiiy) is found at 
Oisans, in France, the fibres of which are in some degree elastic. The word amianthus 
(from hjilavTos, undefiled) is expressive of the easy manner by which, when soiled, it may 
be cleansed and restored to its original purity, by being heated to redness in a fire. See 
Asbestus.— H. W. B. 

AMMONIA. NH 3 , eqv. 17. (Ammoniaque, Fr. ; Ammonial; Germ.) The name 
given to the alkaline gas which is the volatile alkali of the early chemists. The real origin 
of this word is not known. Some suppose it to be from Ammon, a title of Jupiter, near 
whose temple in Upper Egypt it was generated. Others suppose it to be from Ammonia, 
a Cyrenaic territory ; whilst others again have deduced it from &fijj.os, sand, as it was found 
in sandy ground. 

It is probable that Pliny was acquainted with the pungent smell of ammonia. Dr. 
Black, in 1756, first isolated it, proving the distinction between it and its carbonate, with 
which it had been confounded up to that time ; and it was soon afterwards more fully inves- 
tigated by Priestley. 


Ammonia being a product, not only of the destructive distillation of organic bodies con- 
taining nitrogen, but also of their decay, it exists in the atmosphere, in a large amount, if 
considered in the aggregate, although, by examining any particular specimen of air, the 
quantity appears small. Nevertheless, this small quantity of ammonia would seem to be 
exceedingly important in developing the nitrogenized constituents of plants. Liebig be- 
lieves that the nitrogen of plants is exclusively derived from the ammonia present in the 
air ; but the opinions of chemists are divided on this point. Boussingault * supports Lie- 
big's view, but it is opposed by Mulder and Ville. 

From the air, ammonia and its salts are carried down by the rain. This fact has been 
placed beyond all doubt by Liebig ; and even the variations in the quantity have been de- 
termined by Boussingault, and more recently by Mr. Way. By the rain water it is carried 
into rivers, and ultimately into the sea, in which chloride of ammonium has been detected 
by Dr. Marcet. It has likewise been detected in mineral springs, especially brine springs, 
and even in common salt. — Vogel. 

Ammonia is present in the exhalations from volcanoes. During the eruption of Vesu- 
vius in 1794, the quantity of sal ammoniac discharged by the mountain was so great, that 
the peasants collected it by hundredweights, (Bischof;) and in the last eruption of Hecla, 
in Sept., 1845, a similar phenomenon was observed ; and, according to Ferrara, it is some- 
times found in such quantity at Etna, that a very profitable trade has been carried on in it. 
Dr. Daubeny thinks that the volcanic ammonia is produced by the action of water upon 
mineral nitrides, (perhaps the nitrides of silicon,) similar in properties to the nitrides of 
Titanium and Boron, which have been recently more carefully examined by M. St. Claire 
Deville. Ammoniacal salts have likewise been found as a sublimate arising from the com- 
bustion of coal strata. 

The great supply of ammonia and its salts is derived from the destructive distillation of 
organic bodies, animal and vegetable, containing nitrogen ; but its salts exist in plants, and 
to a much larger extent in the liquid and solid excrements of animals. As a urate, it forms 
the chief constituent of the excrement of the boa, as well as that of many birds, hence the 
large quantity of ammoniacal salts in guano. See Guano. 

Formation of Ammonia. — No process has yet been devised for inducing the direct com- 
bination of nitrogen and hydrogen to produce ammonia ; but under the disposing influence 
of the production of other compounds, in the presence of these elements, as well as when 
these gases are presented to each other in the nascent state, their union is effected. 

Thus, when electric sparks are passed through a mixture of nitrogen and oxygen in the 
presence of hydrogen and aqueous vapor, nitrate of ammonia is generated. If, while zinc 
is being dissolved in sulphuric acid, nitric acid be added, much ammonia is formed, (iVes- 
hit ;) so again, if hydrogen and binoxide of nitrogen be passed over spongy platinum, tor- 
rents of ammonia are produced, the hydrogen converting the oxygen of the binoxide into 
water, when the nitrogen, at the moment of its liberation, combines with the hydrogen to 
form ammonia. 

It has even been proposed to carry out this last method on a manufacturing scale. 

Messrs. Crane and Jullien, in their patent of January 18, 1848, describe a method of 
manufacturing ammonia in the state of carbonate, hydrocyanate, or free ammonia, by pass- 
ing any of the oxygen compounds of nitrogen, together with any compound of hydrogen 
and carbon, or any mixture of hydrogen with a compound of carbon or even free hydrogen, 
through a tube or pipe containing any catalytic or contact substance, as follows : — Oxides 
of nitrogen, (such, for instance, as the gases liberated in the manufacture of oxalic acid,) 
however procured, are to be mixed in such proportion with any compound of carbon and 
hydrogen, or such mixture of hydrogen and carbonic oxide or acid as results from the con- 
tact of the vapor of water with ignited carbonaceous matters, and the hydrogen compound or 
mixture containing hydrogen may be in slight excess, so as to ensure the conversion of the 
whole of the nitrogen contained in the oxide so employed into either ammonia or hydro- 
cyanic acid, which may be known by the absence of the characteristic red fumes on allowing 
some of the gaseous matter to come in contact with atmospheric air. The catalytic sub- 
stance which Messrs. Crane and Jullien prefer is platinum, which may be in the state of 
sponge, or it may be asbestos coated with platinum. This catalytic substance is to be placed 
in a tube, and heated to about 600° F., so as to increase the temperature of the product, 
and at the same time prevent the deposition of carbonate of ammonia, which passes onwards 
into a vessel of the description well known and employed for the purpose of condensing 
carbonate of ammonia. The condenser for this purpose must be furnished with a safety 
pipe, to allow of the escape of uncondensed matter, and made to dip into a solution of any 
substance capable of combining with hydrocyanic acid or ammonia where they would be 
condensed. A solution of salt of iron is preferable for this purpose, f 

Chemical Characters. — The gaseous ammonia liberated from its salts by lime (in a man- 
ner to be afterwards described) is a colorless gas of a peculiar pungent odor. It is com- 
posed, by weight, of 1 equivalent of nitrogen and 3 of hydrogen ; or, by volume, of 2 

* Annales de Chimie et dc Physique, xliii. 149. t Phavm. Journ. xiii. 114. 



measures of nitrogen and 6 of hydrogen, condensed to four ; and may be resolved into 
these constituent gases by passing over spongy platinum heated to redness. By a pressure 
of 6 5 atmospheres at 50° F., it is condensed into a colorless liquid. It is combustible, but 
less so than hydrogen, on account of the incombustible nitrogen which it contains ; but its 
inflammability may be readily seen by passing it into an argand gas flame reduced to a 

Upon this variation in density of solutions of ammonia in proportion to their strength, 
Mr. J. J. Griffin has constructed a useful instrument called an Ammonia-metre. It is 
founded upon the following facts : — That mixtures of liquid ammonia with water possess a 
specific gravity which is the mean of the specific gravities of their components ; that in all 
solutions of ammonia, a quantity of anhydrous ammonia, weighing 212|- grains, which he 
calls a test-atom, displaces 300 grains of water, and reduces the specific gravity of the solu- 
tion to the extent of .00125 ; and, finally, that the strongest solution of ammonia which it 
is possible to prepare at the temperature of 62° P., contains in an imperial gallon of solu- 
tion 100 test-atoms of ammonia. 

We extract the following paragraph from Mr. Griffin's paper in the Transactions of the 
Chemical Society, explanatory of the accompanying Table : — 

" The first column shows the specific gravity of the solutions ; the second column the 
weight of an imperial gallon in pounds and ounces ; the third column the percentage of 
ammonia by weight ; the fourth column the degree of the solution, as indicated by the 
instrument, corresponding with the number of test-atoms of ammonia present in a gallon 
of the liquor ; the fifth column shows the number of grains of ammonia contained in a gal- 
lon ; and the sixth column the atornic volume of the solution, or that measure of it which 
contains one test-atom of ammonia. For instance, one gallon of liquid ammonia, specific 
gravity 8 SO, weighs 8 lbs. 128 oz. avirdupois ; its percentage of ammonia, by weight, is 
33-117 ; it contains 96 test-atoms of ammonia in one gallon, and 20400.0 grains of ammo- 
nia in one gallon ; and, lastly, 104' 16 septems containing one test-atom of ammonia. 
Although no hydrometer, however accurately constructed, is at all equal to the Centigrade 
mode of chemical testing, yet the Ammonia-meter, and the Table accompanying it, will be 
found very useful to the manufacturer, enabling him not only to determine the actual 
strength of any given liquor, but the precise amount of dilution necessary to convert it into 
a liquor of any other desired strength, whilst the direct quotation of the number of grains 
of real ammonia contained in a gallon of solution of any specific gravity will enable him to 
judge at a glance of the money-value of any given sample of ammonia. 

Table of Liquid Ammonia, (Griffin.) 

One Test- Atom of Anhydrous Ammonia = NH 3 weighs 212 '5 grains. 

Specific Gravity of Water = 1-00000. One Gallon of Water weighs 10 lbs. and contains 

10,000 Septems. Temperature 62° F. 

Specific Gravity 

of the Liquid 


■Weight of an 

Imperial Gallon in 

Avoirdupois lbs. 

and ozs. 

Percentage of 

Ammonia by 



of Ammonia 

in one 


Grains of 

Ammonia in one 



containing one 

Test-atom of 


lb. oz. 


8 12-0 






8 12-2 






8 12-4 






8 12-6 






8 12-8 






8 13-0 






8 13-2 






8 13-4 






8 13-6 






8 13-8 






8 14-0 






8 14-2 






8 14-4 






8 14-6 






8 14-8 




116-28 ■ 


8 15-0 






8 15-2 






8 15-4 






8 15-6 






8 15-8 






9 0-0 






9 0-2 




120-5S 1 

Vol. III.— 6 




Table of Liquid Ammonia, (continued.) 

Specific Gravity 

of the Liquid 


Weight of an 

Imperial Gallon in 

Avoirdupois lbs. 

and ozs. 

Percentage of 

Ammonia by 



of Ammonia 

in one 


Grains of 

Ammonia in one 



containing one 

Test-atom of 


lb. oz. 


9 0-4 






9 0-6 






9 0.8 






9 1-0 






9 1-2 






9 1-4 






9 1-6 






9 1-8 






9 2-0 






9 2-2 






9 2-4 






9 2-6 







9 2-8 






9 3.0 






9 3-2 






9 3-4 






9 3-6 






9 3-8 






9 4-0 






9 4-2 






9 4-4 






9 4-6 






9 4-8 






9 5-0 






9 5-2 






9 5-4 






9 5-6 






9 5-8 






9 6-0 






9 6-2 






9 6-4 






9 6-6 






9 6-8 






9 7-0 






9 7'2 






9 7-4 






9 7-6 






9 7-8 






9 8-0 






9 8-2 • 






9 8-4 






9 8-6 






9 8-8 






9 9-0 






9 9-2 






9 9-4 






9 9-6 




312-50 • 


9 9-8 






9 10-0 






9 10-2 






9 104 






9 10-6 






9 10-8 






9 11-0 






9 11-2 






9 11-4 






9 11-6 






9 11-8 






9 12-0 






9 12-2 

5-9082 19 4037-5 




Table of Liquid Ammonia, (continued.) 

Specific Gravity 

of the Liquid 


"Weight of an 

Imperial Gallon in 

Avoirdupois lbs. 

and ozs. 

Percentage of 

Ammonia by 



of Ammonia 

in one 


Grains of 

Ammonia in one 



containing one 

Test-atom of 


lb. oz. 


9 12-4 






9 12-6 






9 12-8 






9 13-0 






9 13-2 






9 13-4 






9 13-6 






9 13-8 






9 14-0 






9 14-2 






9 14-4 






9 14-6 






9 14-8 






9 15-0 






9 15-2 






9 15'4 






9 15-6 






9 15-8 






10 lbs. Water. 

Ammoniacal gas combines directly with hydrated acids, forming a series of salts, the 
constitution of which is peculiar, and must be here briefly discussed, that the formula here- 
after employed in describing them may be understood. 

These compounds may be viewed as direct combinations of the ammonia with the 
hydrated acids ; thus, the compound with 

Hydrochloric acid as the 
Hydrosulphuric acid " 
Sulphuric acid " 

Nitric acid " 

Carbonic acid " 

Hydrochlorate, (NH 3 , HC1.) 
Hydrosulphate, (NH S , HS.) 
Hydrated sulphate, (NH 3 ; HO, SO 3 .) 
Hydrated nitrate, (NH 3 ; HO, NO 5 .) 
Hydrated carbonate, (NH 3 ; HO, CO 2 ). 

But the close analogy of these compounds, in all their properties, to the corresponding 
salts of potash and soda has led chemists to the assumption of the existence of a group of 
•elements possessing the characters of a metal, of a basyl or hypothetical metallic radical, 
called ammonium, (NH 4 ,) in these salts ; which theory of their constitution brings out the 
resemblance to the potash and soda salts more clearly, thus : — 

The chloride 

And the chloride 

of potassium contains 

- KC1 

of ammonium contains 

■ NH 4 C1. 

— sulphide " 

- KS. 

— sulphide " 

• NH 4 S. 

— sulphate of potassa " 

- KO, 

SO 3 . 

— sulphate of ammonia ■ 

NH 4 0, SO 3 . 

— nitrate " " 

- KO, 


— nitrate " 

NH 4 0, NO 5 . 

— carbonate " " 

- KO, 

CO 2 . 

— carbonate " 

NH 4 0, CO 2 . 

Although it may be objected to this view that the metal ammonium is not known, yet a 
curious metallic compound of this metal with mercury has been obtained ; and, after all, it 
is by no means necessary that the metal should be isolated, for already the existence of 
numerous basic radicals has been assumed in organic chemistry which have never been 

It is true, also, 1 that the oxide of ammonium is unknown, but substitution-products of it 
have been produced, which are solid bodies, soluble in water, exhibiting all the characters 
of potash solution, being as powerfully caustic and alkaline. In fact, ammonia is in reality 
but the type of a vast number of compounds. It is capable of having its hydrogen 
replaced by metals, (as copper, mercury, calcium, &c.,) as well as by metallic or basic com- 
pound radicals, producing the endless number of artificial organic bases, which are primary, 
secondary, or tertiary nitrides, according as one, two, or three equivalents of the ammonia 
are replaced. When the substitution of the hydrogen in ammonia is effected by acid radi- 
cals, the compounds are called amides. 

Preparation of Ammonia. — Ammonia is obtained by the decomposition of one of the 



salts of ammonia, either the chloride of ammonium, NH 4 C1, (sal ammoniac,) or the sul- 
phate, by a metallic oxide, e. g. lime. 

NH 4 C1 -4- CaO, HO = CaCl + NH 3 -+- 2HO. 

On the small scale in the laboratory the powdered ammoniacal salt is mixed with slaked 
lime, in a Florence flask or a small iron retort, and gently heated ; the ammoniacal gas 
bein"' dried by passing it through a bottle containing lime. Chloride of calcium must not 
be employed in the desiccation of ammonia, since the ammonia is absorbed by this salt, 

( H 3 ) 
producing a curious compound, the chloride of caliammonium, N j Ca )■ CI, being, in fact, 

one of those substitution-compounds before alluded to. 

The gaseous ammonia must be collected over mercury, on account of its solubility in 

This operation is carried out on the large scale for the purpose of making the aqueous 
solution of ammonia, {liquor ammonia, or spirits of hartshorn.) 

Solution of Ammonia. 

Preparation. — In preparing the aqueous solution, the gas is passed into water contained 
in Woolfe's bottles, which on the small scale are of glass, whilst on the large scale they are 
made of earthenware. . 

A sufficiently capacious retort of iron or lead should be employed, which is provided 
with a movable neck ; and it is desirable to pass the gas through a worm, to cool it, before 
it enters the first Woolfe's bottle. Each of the series of Woolfe's bottles should be fur- 
nished with a safety-funnel in the third neck, to avoid accidents by absorption. The whole 
of the condensing arrangements should be kept cool by ice or cold water. 

Properties. — In the London and in the Edinburgh " Pharmacopoeia " two solutions of 
ammonia are directed to be prepared, the stronger having the specific gravity 0-882, and 
containing about 30 per cent, of ammonia ; the weaker of specific gravity 0"960, contain- 
ing, therefore, about 10 per cent, of the gas. 

Sometimes the commercial solution of ammonia is made by treating impure ammoniacal 
salts with lime, and it then contains empyreumatic oils ; in fact, the various volatile prod- 
ucts of the distillation of coal which are soluble in or miscible with water. 

Pyrrol mav be detected in ammonia by the purple color which it strikes with an excess 
of nitric or sulphuric acid. If the residue of its distillation be mixed with potash, Picoline 
is detected by its peculiar odor. Naphthaline is discovered not only by its odor, but may 
also be separated by sublimation or heating, after converting the ammonia in the solution 
into a salt by sulphuric or hydrochloric acid. — Dr. Maclogan. 

We imported into England of sulphate and liquor of ammonia as follows : — 

Ammonia, sulphate of, - - - - 1856, = - lbs. 23,904 
« " .... 1855, - - 343,609 

Ammonia, liquor, .... 1855, - 22,400 

Since, for the purpose of purification on the large scale, ammonia is invariably con- 
verted into chloride or sulphate, the details of the manufacture of the ammoniacal salts 
will be given under those heads. For the determination of ammonia, see Nitrogen. — H. 
M. W. ° 

AMMONIA, CARBONATE OF. {Tlie sesquicarbonate of commerce, 2NH 3 , 3C0 2 , 
2HO=NH 4 0, CO 2 ; HO, C0 2 4-NH 3 C0 2 , eqv. 118.) This salt was probably known to 
Raymond Lully and Basil Valentine, as the chief constituent of putrid urine. The real 
distinction between ammonia and i'ss carbonate was pointed out by Dr. Black. 




Carbonate of ammonia is formed during the putrefaction of animal substances, and by 
their destructive distillation. Its presence in rain water lias been before alluded to. 

The carbonate of ammonia of commerce is obtained by submitting to sublimation a 
mixture either of sal ammoniac or sulphate of ammonia with chalk. 

This is generally carried out in cast-iron retorts, similar in size and shape to those used 
in the manufacture of coal gas. The retorts are charged through a door at one end, and at 
the other they communicate with large square leaden chambers, supported by a wooden 
frame, in which the sublimed salt is condensed. Fig. 25. 

The product of this first process is impure, being especially discolored by the presence 
of carbonaceous matter, and has to be submitted to resublimation. This is carried out in 
iron pots surmounted by movable leaden caps. These tops are either set in brickwork, and 


heated by the flue of the retort furnace, or are placed in a water-bath, as shown in fig. 26. 
In fact, a temperature not exceeding 150° F. is found sufficient. 

The charge of a retort consists usually of about 65 lbs. of sulphate of ammonia (or an 
equivalent quantity of the chloride) to 100 lbs. of chalk, which yield about 40 lbs. of crude 
carbonate of ammonia. 

Modifications of the Process. — Mr. Laming has suggested to bring ammonia and car- 
bonic acid gases into mutual contact in a leaden chamber having at the lower part a layer 
of water, and then to crystallize the salt by evaporating this aqueous solution. 

He also proposes to prepare carbonate of ammonia from the sulphide of ammonium of 
gas liquors, by passing carbonic acid gas into the liquor, which carbonic gas is generated by 
heating a mixture of oxide of copper and charcoal, in the proportion of twelve parts of the 
former to one of the latter. 

Mr. Hill has described his mode of obtaining sesquicarbonate of ammonia from guano. 
To effect this, the guano is first mixed with charcoal or powdered coke ; the mixture is then 
heated, and the sesquicarbonate of ammonia obtained by sublimation. The process does 
not appear to be much employed. 

Manufacture of Ammonia from Peat and Shale. — Mr. Hills, in his patent of August 
11th, 1846, specified the following method of obtaining ammonia from peat: — The peat is 
placed in an upright furnace and ignited ; the air passes through the bars as usual, and the . 
ammonia is collected by passing the products of combustion through a suitable arrange- 
ment of apparatus to effect its condensation. This plan of obtaining ammonia from peat 
appears to be precisely similar to that patented by Mr. Rees Reece, (January 23d, 1849,) 
and made to form an important feature in the operations of the British and Irish Peat Com- 
pany. The first part of Mr. Reece's patent is for an invention for causing peat to be burned 
in a furnace by the aid of a blast, so as to obtain inflammable gases and tarry and other 
products from peat. For this purpose, a blast furnace with suitable condensing apparatus 
is used. The gases, on their exit from the condensing apparatus, may be collected for use 
as fuel or otherwise ; and the tarry and other products pass into a suitable receiver. The 
tarry products may be employed to obtain paraffine and oils for lubricating machinery, &c. ; 
and the other products maybe made available for evolving ammonia, wood spirit, and other 
matters by any of the existing processes. Dr. Hodges, of Belfast, states that in his experi- 
ments he obtained nearly 22J lbs. of sulphate of ammonia from a ton of peat. Sir Robert 
Kane, who was employed by Government to institute a series of experimental researches on 
the products obtainable from peat, states that he obtained sulphate of ammonia at the rate 
of 247io lbs. per ton of peat. Messrs. Drew and Stockton patented, in 1846, the obtaining 
ammonia from peat by distillation in close vessels, as practised in the carbonization of wood. 



It will thus be seen that the peat is a source of ammonia, but that this source is a profitable 
or economical one, in a commercial point of view, is a problem in prdcess of solution. 

Ammonia from Schist. — Another source of ammonia is bituminous schist, which, when 
submitted to destructive distillation, gives off an ammoniacal liquor which may be employed 
in the manufacture of ammoniacal salts by any of the usual processes. The obtaining of 
ammonia from schist forms part of a patent granted to Count de Hompesch, September 4, 

Chemical Composition and Constitution. — The true neutral carbonate of ammonia 
(NH 4 0, CO 2 ) does not appear to exist. The sesquicarbonate of ammonia of the shops was 
found by Rose to have the composition assigned to it by Mr. Phillips, i. e. it contains 
2NH 3 , 3C0 2 , 2HO ; and it may therefore be viewed as a compound of the true bicar- 
bonate, (i. e. the double carbonate of ammonia and water,) NH 4 0, CO 2 ; HO, CO 2 , with a 
peculiar compound of anhydrous carbonic acid with ammonia itself, (NH 3 , CO 2 .) 

The equation representing its method of preparation will then be, 

3NH 4 0, S0 3 +3CaO, C0 2 =(NH 4 0, CO 2 ; HO, CO=+NH 3 , CO ,2 )-f HN 4 0-j-3CaO, SO 3 , 
or 3NH 4 Cl+3CaO, C0 2 =(NH 4 0, CO 2 , HO, C0 2 +NH 3 , C0 2 -fNH 4 0)-f3CaCl ; 

for it is invariably found that a certain quantity of water and ammonia is liberated during 
the distillation, and hence the anomalous character of the compound. In fact, in operating 
upon 3 equivalents of the sulphate or chloride of the 3 equivalents of the true carbonate 
of ammonia (NH 4 0, CO 2 ) which may be supposed to be generated, two are decomposed, 
one losing an equivalent of ammonia, the other an equivalent of water ; of course, the 
ammonia thus liberated is not lost ; it is passed into water to be saturated with acid, and thus 
again converted into sulphate or chloride. 

Properties. — Sesquicarbonate of ammonia (as it is commonly called) is met with in 
commerce in the form of fibrous white translucent cakes, about two inches thick. 

When exposed ' to the air the constituents of the less stable compound NH 3 , CO 2 are 
volatilized, and a white opaque mass of the true bicarbonate remains. Hence the odor of 
ammonia always emitted by the commercial carbonate. Mr. Seanlan has also shown that, by 
treatment with a small quantity of water, the carbonate is dissolved, leaving the bicar- 
bonate. It is soluble in four times its weight of cold water, but boiling water decom- 
poses it. 

Impurities. — The commercial salt is sometimes contaminated with empyreumatic oil, 
which is recognized by its yielding a brownish-colored solution on treatment with water. 

It may contain sulphate and chloride of ammonium. For the recognition of the pres- 
ence of these acids, see Sulphuric Acid. 

Sulphide and hyposulphite of ammonia are sometimes present, and likewise lead, from 
the chambers into which the salt has been sublimed. 

Other Carbonates of Ammonia. — Besides the neutral or monocarbonate of ammonia 
before alluded to, the true bicarbonate (NH 4 0, CO 2 ; HO, CO 2 ) and the sesquicarbonate of 
the shops, Rose has described about a dozen other definite compounds ; but, for their de- 
scription, we must refer to lire's " Dictionary of Chemistry." 

AMMONIA, NITRATE OF. This salt crystallizes in six-sided prisms, being isonior- 
phous with nitrate of potash. 

Its composition is NH'O, NO 5 . It is incapable of existing without the presence of an 
equivalent of water, in addition to NH 3 and NO 6 , If heat be applied,; 'the salt is entirely 
decomposed into protoxide of nitrogen and water ; thus — 

NH 4 0, NO 5 = 2NO -4- 4HO. 

Besides its use in the laboratory for making protoxide of nitrogen, it is a constituent of 
frigorific mixtures, on account of the cold which it produces on dissolving in water. 

Lastly, it is very convenient for promoting the deflagration of organic bodies, both its 
constituents being volatile on heating. 

AMMONIA, SULPHATE OF. (NH 4 0, SO 3 .) This salt is found native in fissures near 
volcanoes, under the name of mossagnine, associated with sal ammoniac. It also forms in 
ignited coal-beds — as at Bradley, in Staffordshire — with chloride of ammonium. 

This salt is prepared by saturating the solution of ammonia, obtained by any of the 
processes before described, (either from animal refuse, from coal, in the manufacture of 
coal-gas, from guano, or from any other source,) with sulphuric acid, and then evaporating 
the solution till the salt crystallizes out. 

Frequently, instead of adding the acid to the ammoniacal liquor, the crude ammoniacal 
liquor is distilled in a boiler, either alone or with lime, and the evolved ammonia is passed 
into the sulphuric acid, contained in a large tun or in a series of Woolfe's bottles ; or a 
modification of Coffey's still may be used with advantage, as in the case of the saturation 
of hydrochloric acid by ammonia. 

If Coffey's still be employed, a considerable concentration of the liquor is effected 
during the process of saturation, which is subsequently completed generally in iron pans ; 


but Teat care has to be taken not to carry the evaporation too far, to avoid decomposition 
of the sulphate by the organic matter invariably present, which reduces it to the state of 
sulphite, hyposulphite, and even to sulphide, of ammonium. 

The salt obtained by this first crystallization is much purer than the chloride produced 
under similar circumstances, and one or two recrystallizations effect its purification suffi- 
ciently for all commercial purposes. 

It is on account of the greater facility of purification which the sulphate affords by crys- 
tallization than the chloride of ammonium, that the former is often produced as a prelimi- 
nary stage in the manufacture of the latter compound, the purified sulphate being then con- 
verted into sal ammoniac by sublimation with common salt. The acid mother-liquor left in 
the first crystallization is returned to be again treated, together with some additional acid, 
with a fresh quantity of ammonia. 

Preparation. Modifications in details and patents. — Since it is in the production of 
the sulphate of ammonia that the modification of Coffey's still, called the ammonia still, is 
generally emploved, it may be well to introduce here a detailed account of its arrangement. 

This apparatus is an upright vessel, divided by horizontal diaphragms or partitions into 
a number of chambers. It is proposed to construct the vessel of wood, lined with lead, and 
the diaphragms of sheet iron. Each diaphragm is perforated with many small holes, so 
regulated, both with regard to number and size, as to afford, under some pressure, passage 
for the elastic vapors which ascend, during the use of the apparatus, to make their exit by 
a pipe opening from the upper chamber. Fitted to each diaphragm are several small 
valves, so weighted as to rise whenever elastic vapors accumulate under them in such quan- 
tity as to exert more than a certain amount of pressure on the diaphragm. A pipe also is 
attached to each diaphragm, passing from about an inch above its upper surface to near the 
bottom of a cup or small reservoir, fixed to the upper surface of the diaphragms next 
underneath. This pipe is sufficiently large to transmit freely downwards the whole of the 
liquid, which enters for distillation at the upper part of the upright vessel ; and the cup or 
reservoir, into which the pipe dips, forms, when full of liquid, a trap by which the upward 
passage of elastic vapors by the pipe is prevented. The vessel may rest on a close cistern, 
contrived to receive the descending liquid as it leaves the lowest chamber, and from this 
cistern it may be run off, by a valve or cock, whenever expedient. The cistern, or in its 
absence the lowest chamber, contains the orifice of a pipe which supplies the steam for 
working the apparatus. The exact number of chambers into which the upright vessel is 
divided is not of essential importance ; but the quantity of liquid and the surface of each 
diaphragm being given, the distillation, within certain limits, will be more complete the 
greater the number of chambers used in the process. .The liquid undergoing distillation in 
this apparatus necessarily covers the upper surface of each diaphragm to" the depth of about 
an inch, being prevented from passing downward through the small perforations by the up- 
ward pressure of the rising steam and other elastic vapors ; and, on the other hand, the 
steam being prevented, by the traps, from passing upwards by the pipes, is forced to ascend 
by the perforations in the diaphragms ; so that the liquid lying on them becomes heated, 
and in consequence gives off its volatile matters. When the ammoniacal liquor accumu- 
lates on one of the diaphragms to the depth of an inch, it flows over one of the short pipes 
into the trap below, and overflows into the next diaphragm, and so on. See Distillation. 

The management of the apparatus varies in some measure with the form in which it is 
desirable to obtain the ammonia. When the ammonia is required to leave the upper cham- 
ber in the form of gas, either pure or impure, it is necessary that the steam which ascends 
and the current of ammoniacal liquid which descends, should be in such relative propor- 
tions that the latter remain at or near the atmospheric temperature during its passage 
through some of the upper chambers, becoming progressively hotter as it descends, until it 
reaches the boiling temperature ; in which state it passes through the lower chambers, either 
to make its escape, or to enter a cistern provided to receive it, and in which it may for 
some time be maintained at a boiling heat. On the contrary, if the ammonia, either pure 
or impure, be required to leave the upper chamber in combination with the vapor of water, 
the supply of steam entering below must bear such proportion to that of the ammoniacal 
liquid supplied above, that the latter may be at a boiling temperature in the upper part of 
the apparatus.* 

The use of this apparatus has been patented in the name of Mr. W. E. Newton, Nov. 
9, 1841. 

Mr. Hill's process, patented Oct. 19, 1848, for concentrating ammoniacal solutions, by 
causing them to descend through a tower of coke through which steam is ascending, is, in 
fact, nothing more than a rough mode of carrying out the same principle which is more 
effectually and elegantly performed by the modification of Coffey's still above described. 
The concentrated ammonia liquor is then treated with acid and evaporated in the usual 

Mr. Wilson has patented, Dec. 7, 1850, another method of saturating the ammonia with 

* Pharm. Journal, xiii. 64. 


the acid by passing the crude ammonia vapor, obtained by heating the ammoniacal liquor 
of the gas-works, in at the bottom of a high tower filled with coke, whilst the sulphuric 
acid descends in a continuous current from the top ; in this manner the acid and ammonia 
are exposed to each other over a greatly extended surface. 

Dr. Richardson (patent, Jan. 26, 1850) mixes the crude ammonia liquors with sulphate 
of magnesia, then evaporates the solution, and submits the double sulphate of magnesia 
and ammonia, which separates, to sublimation ; but it would not appear that any great 
advantage is derived from proceeding in this way, either pecuniary or otherwise. 

Mr. Laming passes sulphurous acid through the gas liquor, and finally oxidizes the sul- 
phite thus obtained to the state of sulphate, by exposure to the air. (Patent, Aug. 12, 

Michiel's mode of obtaining sulphate of ammonia, patented April -30, 1850, is as fol- 
lows : —The ammoniacal liquors of the gas-works are combined with sulphate and oxide of 
lead, which is obtained and prepared in the following way : — Sulphuret of lead in its natu- 
ral state is taken and reduced to small fragments by any convenient crushing apparatus. It 
is then submitted to a roasting process, in a suitably arranged reverberatory furnace of the 
following construction : — The furnace is formed of two shelves, or rather the bottom of the 
furnace and one shelf, and there is a communication from the lower to the upper. The 
galena or sulphuret of lead, previously ground, is then spread over the surface of the upper 
shelf, to a thickness of about 2 or 2| inches, and there it is submitted to the heat of the 
furnace. It remains thus for about two hours, at which time it is drawn off the upper shelf 
and spread over the lower shelf or bottom of the furnace, where it is exposed to a greater 
heat for a certain time, during which it is well stirred, for the purpose of exposing all the 
parts equally to the action of the heat, and at the same time the fusion of any portion of it 
is prevented. By this process the sulphuret of lead becomes converted partly into sulphate 
and partly into oxide of lead. This product of sulphate and oxide of lead is to be crushed 
by any ordinary means, and reduced to about the same degree of fineness as coarse sand. 
It is now to be combined with the ammoniacal liquors, when sulphate of ammonia and sul- 
phuret and carbonate of lead will be produced. 

The sulphate of ammonia is separated by treatment with water, and the residuary mix- 
ture of sulphide and carbonate of lead is used for the manufacture of lead compounds. 

Properties. — The sulphate of ammonia obtained by either of the methods above de- 
scribed is a colorless salt, containing, according to Mitscherlich, one equivalent of water of 
crystallization. It is isomorphous with sulphate of potash. 

It deliquesces by exposure to the air ; 1 part dissolves in 2 parts of cold water, and 1 
of boiling water. It fuses at 140° C, (284° F.,) but at 280° C. (536° F.) it is. decomposed, 
being volatilized in the form of free ammonia, sulphite, water, and nitrogen. 

For the other sulphates — the sulphites and those salts which are but little used in the 
arts and manufactures — we refer to the " Dictionary of Chemistry." 

Uses. — The chief consumption of ammoniacal salts in the arts is in the form of sal 
ammoniac, the sulphate of ammonia being principally used as a material for the manufac- 
ture of the chloride of ammonium. It may, however, be employed directly in making 
ammonia-alum, or in the production of free ammonia by treatment with lime. 

AMMONIUM. (NH 4 .) The radical supposed to exist in the various salts of ammonia. 
Thus NH 4 is the oxide, NH 4 C1 the chloride, of ammonium. Ammonium constitutes one 
of the best established chemical types. See Formulae, Chemical. — C. G. W. 

AMMONIUM, CHLORIDE OF. This salt is formed in the solid state by bringing in 
contact its two gaseous constituents, hydrochloric acid and ammonia. The gases combine 
with such force as to generate, not only heat, but sometimes even light. It may also be 
prepared by mixing the aqueous solutions of these gases, and evaporating till crystallization 
takes place. 

When ammoniacal gas is brought into contact with dry chlorine, a violent reaction 
ensues, attended by the evolution of heat and even light. The chlorine combines with the 
hydrogen to produce hydrochloric acid, which unites with the remainder of the ammonia, 
forming chloride of ammonium, the nitrogen being liberated. The same reaction takes 
place on passing chlorine gas into the saturated aqueous solution of ammonia. 

Manufacture of Sal Ammoniac from Gas Liquor. — By far the largest quantity of the 
ammoniacal salts now met with in commerce is prepared from " gas liquor," the quantity of 
which annually produced in the metropolis alone is quite extraordinary — one of the London 
gas works producing in one year 224,800 gallons of gas liquor, by the distillation of 51,100 
tons of coal ; and the total consumption of coal in London for gas making is estimated at 
about 840,000 tons. 

The principle of the conversion of the nitrogen of coal into ammonia by destructive 
distillation, as in the manufacture of coal gas, will be found described in connection with 
the processes of gas manufacture and the products produced by the destructive distillation 
of coal. ' 

In the purification of the coal gas, the bodies soluble in water are all contained in the 



" o-as liquor," (see Coal Gas,) together with a certain quantity of tarry matter. The am- 
monia is chieflv present in the form of carbonate, together with certain quantities of chlo- 
ride sulphide, cyanide, and sulphocyanide of ammonium, as well as the salts of the com- 
pound ammonias. 

For the purpose of preparing the chloride, if hydrochloric acid be not too costly, the 
liquor is saturated with hydrochloric, acid — the solution evaporated to cause the salt to 
crystallize, and then, finally, the crude sal ammoniac is purified by sublimation. 
' Before treatment with the acid, the liquor is frequently distilled. 

This is generally effected in a wrought-iron boiler, the liquors passing into a modification 
of the Coffey's still," by which the solution of ammonia is obtained freer from tar and more 

The Saturation of the Ammoniacal Liquor with the acid is generally effected by allow- 
in^ the acid to flow, from a large leaden vessel in which it is held, into an underground 


tank (fy. 27) containing the liquor, which is furnished with an exit tube passing into a 
chimney, to carry off the sulphuretted hydrogen and other offensive gases which are disen- 
gaged. _ . , . 

Or, in other works, the gas liquor is put into large tuns, and the acid lifted in gutta- 
percha carboys by cranes, thrown into the liquor and stirred with it by means of an agi- 
tator ; the offensive gases being in this case made to traverse the fire of the steam-engine. 

Sometimes the vapors produced in the distillation of the crude gas liquor are passed in 
at the lower extremity of a column filled with coke, down which the acid trickles. 

The Evaporation of the crude Saline Solution is generally performed in square or rec- 
tangular cast-iron vats, capable of holding from 800 to 1,500 gallons. They are encased in 
brickwork, the heat being applied by a fire, the flue of which takes a sinuous course beneath 
the lining of brickwork on which the pan rests, as shown in fig. 28. 

When the liquor is evaporated to a specific gravity of l - 25, it is transferred to the crys- 
tallizing pans ; but during the processes of concentration a considerable quantity of tar 
separates on the surface, which must be removed, from time to time, by skimming, since it 
seriously impedes evaporation. 

The crystallization, which takes place on cooling, is performed in circular tubs, from 7 
to 8 feet wide, and 2 to 3 deep, which are generally imbedded entirely or partially in the 
ground. To prevent the formation of large crystals, which would be inconvenient in the 
subsequent process of sublimation, the liquor is agitated from time to time. The crude 
mass obtained, which is contaminated with tarry matter, free acid and water, is next dried, 
by gently heating it on a cast-iron plate under a dome. The grayish-white mass remaining 
is now ready to be transferred to the sublimers. 

The method of sublimation generally adopted in this country consists in beating 
down into the metal pots, shown in fig. 29, the charge of dry coarsely crystallized sal am- 
moniac. These pots are heated from below and by flues round the sides. The body of the 
subliming vessel is of cast-iron, and the lid usually of lead, or, less frequently, iron. There 
is a small hole at the top, to permit the escape of steam ; and great attention is requisite in 
the management of the heat, for if it be applied too rapidly a large quantity of sal ammoniac 



is carried off with the steam, or even the whole apparatus may be blown up ; whilst, if the 
temperature be too low, the cake of sal ammoniac is apt to be soft and yellow. 


The sublimation is never continued until the whole of the salt has been volatilized, since 
the heat required would decompose the carbonaceous impurities, and they, emitting volatile 
oily hydrocarbons, diminish the purity of the product. In consequence of this incomplete 
sublimation, a conical mass (shown in fig. 29) is left behind, called the " yolk." After 


cooling, the dome of the pot is taken off, and the attached cake carefully removed. This 
cake, which is from 8 to 5 inches thick, is nearly pure, only requiring a little scraping, 
where it was in contact with the dome, to fit it for the market. 

Modifications of the Process. — If, as is often the case, sulphuric acid is cheaper or more 
accessible than hydrochloric, the gas liquor is neutralized with sulphuric acid, and then the 
sulphate of ammonia thus obtained is sublimed with common salt, (chloride of sodium,) and 
thus converted into sal ammoniac. 

NH 4 SO 3 -j- NaCl = NH 4 Cl+NaOS0 3 . 

Mr. Croll has taken out a patent for converting crude ammonia into the chloride, by 
passing the vapors evolved in the first distillation through the crude chloride of manganese, 
obtained, as a bye product in the preparation of chlorine, for the manufacture of chloride of 
lime : crude chloride of iron may be used in the same way. 


Mr. Laming patented in July, 1843, the substitution of a solution of chloride of calcium 
for treating the crude gas liqilor, instead of the mineral acids. Mr. Hills, August, 1846, 
proposed chloride of magnesium for use in the same way ; and several other patents have 
been taken out by both these gentlemen, for the use of various salts in this way. 

Manufacture of Sal Ammoniac from Guano. — Mr. Young took out a patent, November 
11th, 1841, in which he describes his method of obtaining ammonia and its salts from guano. 
He fills a retort, placed vertically, with a mixture of two parts by weight of guano, and one 
part by weight of hydrate of lime. These substances are thoroughly mixed by giving a 
reciprocating motion to the agitator placed in the retort ; a moderate degree of heat is then 
applied, which is gradually increased until the bottom of the retort becomes red-hot. The 
ammoniacal gas thus given off is absorbed by water in a condenser, whilst other gases, which 
are given off at the same time, being insoluble in water, pass off. Solutions of carbonate, 
bicarbonate, or sesquicarbonate of ammonia are produced, by filling the condenser with a 
solution of ammonia, and passing carbonic acid through it. A solution of chloride of am- 
monium or sulphate of ammonia, is obtained by filling the condenser with diluted hydro- 
chloric or sulphuric acid, and passing the ammonia through it as it issues from the retort. 

Dr. Wilton Turner obtained a patent, March 11th, 1844, for obtaining salts of ammonia 
from guano. The following is his method of obtaining chloride of ammonium in conjunction 
with cyanogen compounds : — The guano is subjected to destructive distillation in close ves- 
sels, at a low red heat during the greater part of the operation ; but this temperature is in- 
creased towards the end. The products of distillation are collected in a series of Woolfe's 
bottles, by means of which the gases evolved during the operation may be made to pass two 
or three times through water, before escaping into the air. These products consist of car- 
bonate of ammonia, hydrocyanic acid, and carburetted hydrogen, the first two of which are 
rapidly absorbed by the water, with the formation of a strong solution of cyanide of am- 
monium and carbonate of ammonia. After the ammoniacal solution has been removed from 
the Woolfe's apparatus, a solution of protochloride of iron is added to it, in such quantities 
as will yield sufficient iron to convert the latter into Prussian blue, which is formed on the 
addition of hydrochloric acid in sufficient quantity to neutralize the free ammonia; the 
precipitate thus formed is now allowed to subside, and is carefully separated from the solu- 
tion, and by being boiled with a solution of potash or soda, will yield the ferrocyanide of 
the alkali, which is obtained by crystallizing in the usual way. The solution (after the 
removal of the precipitate) should be freed from any excess of iron it may contain, by the 
careful addition of a fresh portion of the ammoniacal liquor, by which means the oxide of 
iron will be precipitated, and a neutral solution of ammonia obtained. When the precipi- 
tated oxide and cyanide of iron have subsided, the solution of chloride of ammonium is 
drawn off by a syphon, and the sal ammoniac obtained from it by the usual processes ; the 
oxide of iron is added to the ammoniacal solution next operated upon. 

If sulphate of iron and sulphuric acid are used, sulphate of ammonia is the ammoniacal 
salt produced, the chemical changes and operations being similar to the above. 

Since the greater part of the nitrogen present in guano exists in the state of ammoniacal 
salts, which are decomposed at a red heat, nearly the whole of the ammonia which it is 
capable of yielding is obtained by this method ; still there cannot be a doubt that the con- 
version of the urea, uric acid, and other nitrogenized organic bodies into ammonia, is 
greatly facilitated by mixing the guano with lime before heating it, as in Mr. Young's 

Manufacture of Sal Ammoniac from Urine. — The urea in the urine of man and other 
animals is extremely liable to undergo a fermentative decomposition in the presence of the 
putrefiable nitrogenous matters always present in this excrement, by which it is converted 
into carbonate of ammonia. 

By treating stale urine with hyhrochloric acid, sal ammoniac separates on evaporation. 

Properties. — Chloride of ammonium (or sal ammoniac) usually occurs in commerce in 
fibrous masses of the form of large hemispherical cakes with a round hole in the centre, 
having, in fact, the shape of the domes in which it has been sublimed. By slowly evaporat- 
ing its aqueous solution, the salt may occasionally be obtained in cakes nearly an inch in 
height ; but it generally forms feathery crystals, which are composed' of rows of minute oc- 
tahedra, attached by their extremities. Its specific gravity is l - 45, and by heating it 
sublimes without undergoing fusion. It has a sharp and acrid taste, and one part dissolves 
in 2-72 parts of hot, or in an equal weight of cold water. 

It is recognized by its being completely volatile on heating, giving a white curdy preci- 
pitate of chloride of silver on the addition of nitrate of silver to its aqueous solution, and by 
the copious evolution of ammonia on mixing it with lime, as well as the production of the 
yellow precipitate of the double chloride of ammonium and patinum (NH"C, Pad'-) on 
the addition of bichloride of platinum. 

Impurities. — In the manufacture of chloride of ammonium, if the purification of the 
liquor be not effected before crystallizing the salt, some traces of protochloride of iron are 
generally present, and frequently a considerable proportion. Even when the salt is 


sublimed, the chloride of iron is volatilized together with the chloride of ammonium, and 
appears to exist in the salt in the form of a double compound (probably of Fe, CI NH J C1 
analogous to the compounds which chloride of ammonium forms with zinc and tin) 140 • 
and this not only in the brown seams of the cake, but likewise in the colorless portion! 
This accounts for the observation so often made in the laboratory, that a solution of sal 
ammoniac, which, when recently prepared, was perfectly transparent and colorless becomes 
gradually red from the peroxidation of the iron and its precipitation in the form 'of sesqui- 

It is in consequence of the existence of the iron in the state of this double salt, that 
Wurtz found that chloride of ammonium containing iron in this form gave no indications 
of its presence by the usual re-agents until after the addition of nitric acid ; and it is curious 
that there likewise exists a red compound of this class in which the iron exists in the state 
of perchloride similarly marked, in fact as NH 4 CI Fe 2 Cl 3 . 

A very simple method of removing the iron, suggested by Mr. Brewer, consists in pass- 
ing a few bubbles of chlorine gas through the hot concentrated solution of the salt, by which 
the protochloride of iron is converted into the perchloride. 

2Fe CI + CI = Fe 2 Cl 3 . 

The free ammonia always present in the solution decomposes this perchloride with pre- 
cipitation of sesquioxide, and formation of an additional quantity of sal ammoniac. 

Fe 2 Cl 3 + 3NH 4 = Fe 2 3 + 3NH 4 C1. 

The sesquioxide of iron, which is of course present in the form of a brown hydrate, is 
filtered off or separated by decantation, and a perfectly pure solution is obtained. 

The only precaution necessary is to avoid passing more chlorine than is requisite to 
peroxidize the iron, since the ammonia salt itself will be decomposed with evolution of 
nitrogen, and the dangerously explosive body, chloride of nitrogen, may result from the 
union of the liberated nitrogen with chlorine. 

Uses. — The most important use of sal ammoniac in the arts is in joining iron and 
other metals, in tinning, &c. It is also extensively used in the manufacture of ammonia- 
alum, which is now largely employed in the manufacture of mordants instead of potash- 
alum. A considerable quantity is also consumed in pharmacy. 

Sal ammoniac is one of those salts which possess, in a high degree, the property of 
producing cold whilst dissolving in water ; it is, therefore, a common constituent of frigorific 
mixtures. See Freezing. 

AMMONIUM, SULPHIDES OF. When sulphuretted hydrogen gas is passed into a solu- 
tion of ammonia in excess, it is converted into the double sulphide of ammonium and hy- 
drogen — or, as it is frequently called, the hydrosulphate of sulphide of ammonium 


This solution is extensively employed as a re-agent in the chemical laboratory, for the 
separation of those metals the sulphides of which are soluble in acids — viz., nickel', cobalt 
manganese, zinc, and iron, which are precipitated by this re-agent in alkaline solutions. 

By exposure to the air, the hydrosulphuric acid which it contains is decomposed, the 
hydrogen being oxidized and converted into water, whilst the liberated sulphur is dissolved 
by the sulphide of ammonium, forming the bisulphide, or even higher sulphide. 

This solution of the polysulphide of ammonium is a valuable re-agent for dissolving the 
sulphides of certain metals, such as tin, antimony, and arsenic, the sulphides of which play 
the part of acids and form salts with the sulphide of ammonium. 

By this deportment with sulphide of ammonium, these metals are separated both on the 
small scale in the laboratory and also on the large scale, from the sulphides of those metals 
— such as lead, copper, mercury, &c. — the sulphides of which are insoluble in sulphide of 

The higher sulphides, viz., the tersulphide, NH 4 S 3 , and the pentasulphide, NH 4 S 6 , — are 
bodies of purely scientific interest. They are obtained by distilling the corresponding 
sulphides of potassium with sal ammoniac. 

All the sulphides of ammonium are soluble in water without decomposition. 

Ammonia combines with all the other inorganic and organic acids, the name of which 
is " legion ; " but for an account of these bodies we must refer to the " Dictionary of 
Chemistry," as they have but few applications in the arts and manufactures. 

AMORPHOUS. This term may be regarded as the opposite of crystalline. Some 
elements exist in both the crystalline and the amorphous states, as carhon, which is amor- 
phous in charcoal, but crystalline in the diamond. 

The peculiarities which give rise to these conditions — evidently depending upon mole- 
cular forces which have not yet been defined — present one of the most fertile fields for study 
in the range of modern science. 

AMYGDALINE. (C 4 ° H 27 NO 22 + 6H0.) A peculiar substance, existing ready formed 
in bitter almonds, the leaves of the cherry laurel, the kernels of the plum, cherry, peach, 


and the leaves and bark of Primus padus, and in the young sprouts of the P. domestica. 
It is also found in the sprouts of several species of Sorbics, such as S. aucuparia, S. tormi- 
nalis, and others of the same order. To prepare it, the bitter almonds are subjected to 
strong pressure between hot plates of metal. This has the effect of removing the bland oil 
known in commerce as almond oil. The residue, when powdered, forms almond meal. To 
obtain amygdaline from the meal, the latter is extracted with boiling alcohol of 90 or 95 
per cent. The tincture is to be passed through a cloth, and the residue pressed, to obtain 
the fluid mechanically adherent to it. The liquids will be milky, owing to the presence of 
some of the oil. On keeping the fluid for a few hours, it may be separated by pouring off, 
or bv means of a funnel, and so obtained clear. The alcohol is now to be removed by dis- 
tillation, the latter being continued until five-sixths have come over. The fluid in the 
retort, when cold, is to have the amygdaline precipitated from it by the addition of half its 
volume of ether. The crystals are "to be pressed between folds of filtering paper, and re- 
crystallized from concentrated boiling alcohol. As thus prepared it forms pearly scales very 
soluble in hot alcohol, but sparingly when cold ; it is insoluble in ether, but water dissolves 
it readily and in large quantity. The crystals contain six atoms of water of crystallization. 
Most persons engaged in chemical operations have noticed, when using almond meal for the 
purpose of luting, that, before being moistened with water, it has little odor, and what it 
has is of an oily kind ; but, after moistening, it soon acquires the powerful and pleasant 
perfume of bitter almond oil. This arises from a singular reaction taking place between the 
amygdaline and the vegetable albumen or emulsine. The latter merely acts as a ferment, 
and its elements in no way enter into the products formed. The decomposition, in fact, 
takes place between one equivalent of amygdaline and four equivalents of water, the prod- 
uct being one equivalent of bitter almond oil, two equivalents of grape sugar, and one of 
prussic acid. Or, represented in symbols : — 

C 4o H o.7 NQ22 _[_ 4H q = c 14 H 6 0- -\- C 2 HN + 2C 12 H 12 12 . 

Amygdaline. Bitter-almond Prussic Grape sugar. 

oil. acid. / 

In preparing amygdaline, some chemists add water to the residue of the distillation of 
the tincture, and then yeast, in order to remove the sugar present, by fermentation, previous 
to precipitating with ether ; the process thus becomes much more complex, because it is 
necessary to filter the fermented liquid, and concentrate it again by evaporation, before 
precipitating out the amygdaline. 

The proof that the decomposition which is experienced by the bitter almond cake, when 
digested with water, is owing to the presence of the two principles mentioned, rests upon 
the following considerations : If the marc, or pressed residue of the bitter almond, be 
treated with boiling water, the emulsine — or vegetable albumen — will become coagulated, 
and incapable of inducing the decomposition of the amygdaline. Moreover, if the latter be 
removed from the marc with hot alcohol previous to operating in the usual manner for the 
extraction of the essential oil, not a trace will be obtained. It is only the bitter almond 
which contains amygdaline ; the sweet variety is, therefore, incapable of yielding the essence 
by fermentation. But sweet almonds resemble the bitter in containing emulsine ; and it is 
exceedingly interesting— as illustrating the truth of the explanation given above— that if a 
little amygdaline be added to an emulsion of sweet almonds, the bitter almond essence is 
immediately formed. The largest proportion of essential oil is obtained when the marc is 
digested, previous to distillation, with twenty times its weight of water, for a day and a 
night. A temperature of 100° is the most favorable for the digestion. — C. G. W. 

ANCHOR. The metal employed for anchors of wrought-iron is known as " scrap 
iron," and for the best anchors, such as Lenox's, they also use good " Welsh mine iron." 

It is not practicable, without occupying more space than can be afforded, to describe in 
detail the manufacture f an anchor. It does not, indeed, appear desirable that we should 
do so, since it is so special a form of mechanical industry, that few will consult this volume 
for the sake of learning to make anchors. The following will therefore suffice : The an- 
chor smith's forge consists of a hearth of brickwork, raised about 9 inches above the ground, 
and generally about 7 feet square. In the centre of this is a cavity for containing the fire. 
A vertical brick wall is built on one side of the hearth, which supports the dome, and a low 
chimney to carry off the smoke. Behind this wall are placed the bellows, with which the 
fire is urged ; the bellows being so placed that they blow to the centre of the fire. The an- 
vil and the crane by which the heavy masses of metal are moved from and to the fire are 
adjusted near the hearth. The Hercules, a kind of stamping machine, or the steam ham- 
mer, need not be described in this place. 

To make the anchor, bars of good iron are brought together to be fagoted ; the num- 
ber varying with the size of the anchor. The fagot is kept together by hoops of iron, and 
the whole is placed upon the properly arranged hearth, and covered up by small coals, 
which are thrown upon a kind of oven made of cinders. Great care and good management 
are required to keep this temporary oven sound during the combustion ;— «-a smith strictly 



attends to this. When all is arranged, the bellows are set to work, and a blast urged on the 
fire ; this is continued for about an hour, when a good welding heat is obtained. The mass 
is now brought from the fire to the anvil, and the iron welded by the hammers. One por- 
tion having been welded, the iron is returned to fire, and the operation is repeated until the 
whole is welded into one mass. 

This will be understood by referring to the annexed figures, {fig. 30,) in which the bars 
for the shanks, a a, and the arms, b b, are shown, in plan and sections, as bound together, 
and their shapes after being welded before union ; and c c represents the palm. 

The different parts of the anchor being made, the arms are united to the end of the 
shank. This must be done with great care, as the goodness of the anchor depends entirely 
upon this process being effectively performed. The arms being welded on, the ring has to 
be formed and welded. The ring consists of several bars welded together, drawn out into 
a round rod, passed through a hole in the shank, bent into a circle, and the ends welded 
together. When all the parts are adjusted, the whole anchor is brought to a red heat, and 
hammered with lighter hammers than those used for welding, the object being to give a 
finish and evenness to the surface. 

The toughest iron which can be procured should be used in the manufacture of an anchor, 
upon the strength of which both the security of valuable lives and much property depend. 

The following drawings {fig. 31) show an anchor on the old plan, and the dissected parts 
of which it is composed : — 



and the annexed, (fig. 32,) the patent anchor as invented by Mr. Perring, with its several 
parts dissected as before : — 

Previously to the introduction of Lieutenant Rodger's small-palmed anchor, ships were 
supplied with heavy, cumbersome contrivances with long shanks, and broad palms extending 
half way up the flukes. So badly were they proportioned, that it was no uncommon thing 
for them to break in falling on the bottom, particularly if the ground was rocky. But, if 
once firmly imbedded in stiff holding ground, there was considerable difficulty in breaking 
them out. The introduction of the small palm, therefore, forms an important era in the 
history of anchors. 

The next important introduction was Porter's anchor, with movable flukes or arms. 
One grand object sought to be attained here, was the prevention of fouling by the cable. It 
was considered, also, that as great injury was frequently occasioned by a ship grounding on 
her anchor, the closed upper arm would remedy the evil. It was found, however, that the 
anchor would not take the ground properly as at first constructed, and hence the " shark's 
fins " upon the outside of each fluke. 

Rodger's invention was for some time viewed with distrust ; but, from time to time, im- 
provements were introduced, until the patent, which gained the Exhibition prize, was 
brought out. On this the jurors reported as follows : — 

" Many remarkable improvements have been recently made by Lieutenant Rodger, 
R.N., insuring a better distribution of the metal in the direction of the greatest strains. 
The palm of the anchor, instead of being flat, presents two inclined planes, calculated for 
cutting the sand or mud instead of resisting perpendicularly ; and the consequence is, that 
these new anchors hold much better in the ground. The committee of Lloyd's — so compe- 
tent to judge of every contrivance likely to preserve ships — have resolved to allow for the 
anchors of the ships they insure a sixth less weight if made according to the plan of Lieu- 
tenant Rodger." 

The original Porter's anchor has also undergone considerable modification ; and, under 
the name of " Trotman's anchor," has now a conspicuous place. 

Another invention is that of Mitcheson's, which, in form and proportions, strongly re- 
sembles Rodger's ; but the palm is that adopted in Trotman's, or Porter's anchor. It is a 
trifle longer in the shank than Rodger's, and has a peculiar stock, which — although original 
in its form — lacks originality in its design, since Rodger had previously introduced a plan 
for an iron stock to obviate the weakness caused by making a hole for the stock to pass 
through. Mr. Lenox was the inventor of an anchor which differed somewhat from the 
Admiralty's anchor — a modification of Rodger's, — in being shorter in the shank and thicker 
in the flukes, the palms being spade-shaped. Mr. J. Aylen, the Master- Attendant of Sheer- 
ness Dockyard, modified the Admiralty's anchor. Instead of the inner part of the fluke, 
from the crown to the pea, being rounded, as in the Admiralty plan, or squared, as in 
Rodger's and Mitcheson's, it is hollowed. An American anchor known as Isaac's, has a flat 
bar of iron from palm to palm, passing the shank elliptically on both sides ; and from the 
end of the stock to the centre of the shank two other bars are fixed to prevent its fouling. 

With the anchors thus briefly described the Admiralty ordered trials to be made at Wool- 
wich, and at the Nore. The results of those trials — the particulars of which need not be given 
here — were, that Mitcheson's, Trotman's, Lenox's, and Rodger's, were selected as the best. 



A competent authority, writing in the United Service Gazette, says : — " The general 
opinion deduced from the series of experiments is, that although Mitcheson's has been so 
successful, the stock is not at present seaworthy. Trotman's has come out of the trial very 
successfully, but the construction is too complicated to render it a good working anchor. 
When once in the ground, its holding properties are very superior ; in fact, a glance at its 
grasp will show that it has the capabilities of an anchor of another construction one-fifth 
larger. There are, however, drawbacks not easily to be overcome. Its taking the ground 
is more precarious than with other anchors ; and if a ship should part her cable, it would 
scarcely be possible to sweep the anchor. It is also an awkward anchor to fish and to stow. 
Yet there are other merits which render it, upon the whole, a most valuable invention, and 
no ship should go to sea without one. Of Lenox's, it is sufficient to say that it lias been 
found equal to, and that it has gained an advantage over, Rodger's ; but so strong is the 
professional feeling in favor of the latter, that it will ever remain a favorite. Our recom- 
mendation would be thus : — Lenox and Rodger for bower anchors, Mitcheson for a sheet, 
and Trotman for a spare anchor." 

The following table gives at one view the results of the experiments made by the Ad- 
miralty upon breaking the trial anchors, and the time occupied upon each experiment : — 

. Anchors. 





Time in 

Lieut. Rodger's 
Brown and Lenox's - 
Isaac's .... 
Trotman's ... 
Honiball's ... 
Admiralty's ... 
Aylen's .... 

Cwts. qrs. lbs. 

19 8 

20 3 14 

21 14 
21 1 10 
20 3 1 

20 2 6 

21 1 


21 2 
















The history of the introduction of Lenox's anchors to the British navy was as follows : — 
After sundry attempts to induce the Admiralty to give up entirely the use of hempen 
cable anchors, in consequence of their breaking when applied to chain cables, Mr. Lenox, in 
1832, was permitted to alter some of the old anchors to such proportions and shape as 
would enable them to stand a proof-strain upon the machine in Woolwich Dockyard. It 
was found, as previously apprehended and asserted, that, from the inequality of material in 
the old anchors, not above one in three was successfully altered, and Mr. Lenox was ordered 
to supply new anchors, which were proved, and then approved of. This state of things 
continued until 1838, when Mr. Lenox was requested to reconsider and complete the shape 
and proportions of anchors for the navy, with a view to a contract being given out for 
the supply of such anchors to the service. Then was constructed the shape called the 

" Admiralty," or " Sir William Parker's Anchor," (Sir 
William being then Store Lord.) Mr. Lenox suggested 
to Sir William the doing away with every sharp edge 
and line in an anchor, and adopting the smooth long- 
oval (in the section) for the general shape of shank 
and arm. This was approved of by Sir William, and he 
brought it out as his anchor. An entire table of pro- 
portions was furnished ; but that it might meet with no 
opposition from the influence of dockyard authority, it 
was sent to the officers of Portsmouth Yard for their 
approval. They returned it, after a few months, with 
some slight alterations in the proportions of some of 
the sizes, and recommended the construction to be on 
" Perring's principle " of the cushioned, or made-up 
crown. It was so adopted, and continued to be made 
by Brown and Lenox for about a year or two, when 
the great and unnecessary expense incurred by the plan 
was pointed out. It was contended it was without any 
good ; because, if the crown of the anchor, or any shut 
or weld, was made sound and perfect, the amalgamation 
of the grain of the iron would be complete, and assume 
its full power or strength, whatever way it might be put 
together ; and the strongest form was that which exposed 
the least surface of iron to the welding heat, and consequently to injury. About the latter end 
of 1839, the subject was again opened. Mr. Lenox renewed his objections, by letter, to Sir 
William Parker, to " Perring's plan " of shutting-up, and the consequence was — a contract 
with specification, &e. &c, appeared, and an improved or modified plan of shutting-up (as it 



is called) was proposed by Mr. Tyler, master-smith of Portsmouth Yard, which was adopted ; 
and Mr. Lenox's shape and proportions, (slightly altered, as before said,) came out as " Sir 
TTilliam Parker's," or the " Admiralty Anchor," and continued, until after the trials in 
1S52, with evert/ success in actual service that a good anchor could maintain, and they were 
made and sold in quantities to all the world. 

In the navy of England, and in nearly all foreign navies, this anchor, of which fig. 33 
represents the form, was adopted. They are also largely employed in the merchant service ; 
but these are not so nicely proportioned as the anchors made for the Government, nor are 
they so highly finished. Many merchant captains, however, take Rodger's anchor, and our 
steamers almost invariably take Porter's or Trotman's anchor. 

Vol. III.— 7 



Trot-mail's Anchor is represented in fig. 34, under its various positions. Although for 
convenience Trotman's anchor is, as we have already stated, largely used by the merchant 
steamers, we cannot but feel that the separation of the fluke from the shaft, although it may 
be in many cases unobjectionable, is attended with the risk that when, in an emergency, the 
anchor is required, the means of connection may be at fault. 

Captain Hall's anchor is a very valuable one, from the circumstance that it is capable of 
division, as shown in fig. 35, so that it can be taken out in boats. 

There are various other shapes of anchors ; but attention has been confined to those 
generally employed. 

We are not in a position to offer any opinion upon the value of the several anchors 
which have been named. Having described their peculiarities, there remains but little to 
be said. The solidity of Lenox's anchors — as shown in fig, 36, and again in their more 
recent modifications, in plan and section, with the new form of iron stock, fig. 37 — has 
recommended them strongly, and hence their general use. 

The weight of anchors for different vessels is proportioned to the tonnage. The follow- 
ing table shows the number of anchors now carried, and the weights of each anchor, by 
merchant vessels by the regulation of Lloyd's. 

Lloyd's Regulation for the Number and Weights of Anchors for Merchant Vessels. 

Ship's Tonnage. 




Wood Stock. 

Iron Stock. 















































































































































3 . 


















' 3 















8* ' 















ANCHOVY. (Anchois, Fr. ; Acciughe, It. ; ^.rcscAoi'e, Germ.) The Clupea encrasi- 
cohis of Linnaeus, a small fish, resembling the sprat, common in the Mediterranean Sea. 
The Gorgona anchovy is considered the best. Sardines (which see) are sometimes substi- 
tuted for anchovies. 

ANDIRONS, or HAND-IRONS, also called Firedogs. Before the introduction of raised 
and close fireplaces these articles were in general use. Strutt, in 1175, says : " These awnd- 
irons are used at this day, and are called ' cob-irons ' ; they stand on the hearth, where they 
burn wood, to lay it upon ; their fronts are usually carved, with a round knob at the top ; 
some of them are kept polished and bright : anciently many of them were embellished with 
a variety of ornaments." 

ANEMOMETER. (cLve/xos, wind ; perpew, to measure.) An instrument or machine to 
measure the wind, its direction and force. Three descriptions of anemometers are now 
usually employed : — 1, Dr. Whewell's ; 2, Mr. Follett Osier's ; 3, Dr. Robinson's. This is 
not the place to describe either of those most ingenious instruments, a full account of which 
will be found in the " Transactions of the British Association," and of the " Royal Irish 

ANEROID BAROMETER. This instrument was invented by M. Vidi, of Paris. In its 
latest form it consists of a cylindrical case, about 4 or 6 inches in diameter, and 2 \ inches 
deep, in which lies a thin metal box, near to, and parallel with, the curved boundary of the 
case, its two ends being distant about half an 
inch from each other. Fron» this box the air 
has been partially exhausted, and the pressure 
of the external atmosphere on it causes it to 
alter its form. The accompanying figure (38) 
shows a section of this box. It is made of 
thin corrugated plates of metal, so that its elas- 
ticity is great. By means of the tube f, the 
air is partially exhausted, when the box takes 
the form shown by the dotted lines. A small 
quantity of gas is introduced after exhaustion, the object of which is to compensate for the 
varying elasticity of the metal at different temperatures. The pressure of the air on the box 
in ordinary instruments is between 40 and 50 lbs., and it will be easily understood that any 
variation in this pressure will occasion the distances between the two plates to vary, and 
consequently the stalk will have a free motion in or out. This is, by an ingenious contriv- 
ance, changed from a vertical motion to a motion parallel to the face of the dial, and this 
is converted into a rotatory one by the application of a watch-chain to a small cylinder or 
drum. The original very slight motion is augmented by the aid of levers. This is so effec- 
tually done, that when the corrugated surfaces move through only the 250th part of an 
inch, the index hand on the face turns over a space of three inches. The extreme portabil- 
ity of this little instrument, and its comparative freedom from risk of injury, render it ex- 
ceedingly useful to the traveller. Its accuracy is proved by the experiments of Professor 
Lloyd, who placed one under the receiver of an air-pump, and found that its indications 
corresponded with those of the mercurial gauge to less than - 01 of an inch ; and within 
ordinary variations of atmospheric pressure the coincidences are very remarkable. — Lloyd, 
Nichol, Drew. 

ANGELICA. (AngUique, Fr. ; Angelika, Germ.) The archangelica officinalis. The 
dried angelica root is imported from Hamburg in casks. The tender stems, stalks, and the 
midribs of the leaves are made, with sugar, into a sweetmeat, (candied angelica.) The an- 
gelica root and seeds are used by rectifiers and compounders in the preparation of gin, and 
as an aromatic flavoring for " bitters." It is cultivated in some moist places in this country. 
In 1856 we imported 231 tons of angelica root. 

ANGORA WOOL. (Poil de chevron d 'Angora, Fr.) Called also angola and angona. 
The wool of the Angora goat, (Capra Angorensis,) employed in the manufacture of the 
shawls of Cashmere, &c. This is obtained from the long-haired goat of Angora, to which 
province this animal is peculiar. Lieutenant Conolly has given an account of this goat and 
some other varieties : — 

" The country where it is found was thus described to us — ' Take Angora as a centre, 
then Kizzil Ermak (or Haly's) Chomgere, and from 8 to 10 hours' march (say 30 miles) 
beyond; Beybazar, and the same distance beyond, to near Nalaban ; Sevree, Hissar, 
Yoorrook, Tosiah, Costambool, Geredeh, and Cherkesh, from the whole of which tract the 
common bristly goat is excluded, and the white-haired goat alone is found.' The fleece of 
the white Angora goat is called tiftik, (the Turkish for goats' hair,) in distinction to yun, or 
yapak, sheep's wool. After the goats have completed their first year, they are clipped 
annually, in April or May, and yield progressively, until they attain full growth, from 150 
drachms to 1\ oke of tiftik, (from 1 lb. to 4 lbs. English.) " The hair of the tiftik goat is 
exported from its native districts raw, in yarn, and woven in the delicate stuffs for which An- 
gora has been long celebrated. The last arc chiefly consumed in Turkey, while the yarn 


and raw material are sent to Fi ance and England. It appears that the first parcels of An- 
gora wool were shipped from Constantinople for England in 1820, and was so little appre- 
ciated that it fetched only lOd. the pound. The exports from Constantinople then increased 
as follows : — 

1836 - - - - . - - - - 3,841 bales 

1837 - 2,261 " 

1838 5,528 " 

" Within the last two or three years, a new texture made of goats' wool has, however, 
been introduced both into France and this country, which calls for particular attention. 
This texture consists of stripes and checks expressly manufactured for ladies' dresses, and 
having a soft feel and silky appearance. The wool of' which this article is made is chiefly 
the wool of the Angora goat. This wool reaches us through the Mediterranean, and is 
chiefly shipped at Smyrna and Constantinople. In color it is the whitest known in the 
trade, and now more generally used in the manufacture of fine goods than any other. 
There are, however, other parts of Asiatic Turkey from which limited supplies are received ; 
but in quality not so good as that produced in Angora. After the manufacture of shawls 
with goats' wool declined in France, this raw material remained neglected for a long while. 
About two or three years ago (1852) however, the French made another attempt, and 
brought out a texture for ladies' dresses in checks and stripes, which they call ' poil de 
chevre." 1 The warp is a fine spun silk, colored, and the *yeft Angora or Syrian white wool, 
which was thus thrown on the surface. This article has a soft feel, and looks pretty, but in 
wearing is apt to cut. The price of a dress of French manufacture has been from 21. 10s. 
to 3/. ; but by adopting a cotton warp, the same article is now made in England and sold 
for 15s. ; and it is found that the cotton warp, as a mixture, suits the goats' hair best." — 
Southey on Colonial Sheep and Wool, London, 1852. 

Angora goats' wool is used for the manufacture of plush, and for coach and decorative 
laces. It is also used extensively for buttons, button-holes, and the braidings of gentle- 
men's coats. It is equally made up into a light and fashionable cloth, suited for paletots 
and overcoats, possessing the advantage of repelling wet. In France this article is now 
applied to the manufacture of a new kind of lace which in a great measure supersedes the 
costly fabrics of Valenciennes and Chantilly. The Angora wool lace is more brilliant than 
that made from silk, and costing only half the price, it has come into very general wear 
among the middle classes. The same material is also manufactured into shawls, which sell 
from 41. to 16/. each. There is much difficulty in ascertaining the quantity of Angora 
wool used in France, as in the returns it is mixed up with the wool of goats of Thibet, all 
being entered as poll de Cachemire. See Mohair. 

ANILINE. (C 12 H 7 N. Syn. Phenylamine, Cyanol, Benzidam, Crystalline.) This 
organic base having recently met with an important application in the arts in the production 
of a beautiful dye-oolor, by Mr. William H. Perkin, a short description of the methods of 
preparing it, and of some of its characters, becomes necessary ; though for details of its 
most interesting relations in scientific chemistry, we must refer to the " Dictionary of 

Preparation. — There are few bodies which admit of being prepared in a greater variety 
of ways — all of them interesting in tracing the chemical history of this most curious body ; 
but we will only here describe that one which might be most advantageously carried out on 
a manufacturing scale. Probably the most abundant source of aniline is the basic oil of 
coal tar. 

The oil is agitated with hydrochloric acid, which seizes upon the basic oils ; after decant- 
ing the clear liquor, which contains the hydrochlorates of these oils, it is evaporated over an 
open fire until it begins to disengage acrid fumes, which indicate a commencement of de- 
composition, and then filtered to separate any adhering neutral compounds. The clear 
liquor is then decomposed with potash or milk of lime, which liberates the bases themselves 
in the form of a brown oil, consisting chiefly of a mixture of aniline (C 12 H 1 N) and leucol 
or quinoleine, (C Ie H 8 N.) This mixture is submitted to distillation, and the aniline is chiefly 
found in that portion which passes over at or about 360° F., (182° C. :) repeated rectification 
and collection of the product distilling at this temperature purify the aniline; but to 
complete the purification, it is well to treat the partially purified aniline once more with 
hydrochloric acid, to separate the bases again by an alkali, and then to rectify carefully. 

The violet reaction of aniline with solution of bleaching powder enables the operator to 
test the distillate from time to time, to ascertain when aniline ceases to pass over, since 
leucol does not possess this property. — Hofmann. 

Aniline may also be obtained in quantity from indigo. 

When indigo-blue (see Indigo) is dissolved by the aid of heat in a strong solution of 
potash, and the mass, after evaporation to dryness, submitted to destructive distillation, it 
intumesces considerably, and aniline is liberated, which condenses in the receiver in the 
form of a brown oil, together with a little water and ammonia disengaged with it. The 


aniline is purified by rectification, as in the method before described. By this process the, 
quantity of aniline obtained is about IS to 20 per cent, of the indigo used. — Fritzche. 

By "treatment with potash, the indigo-blue (C 16 H 5 NO 2 ) is converted into chrysanilio 
acid and anthranilic acid, (C 14 H' NO 4 ;) and it is this latter body which, by destructive dis-> 
tillation, yields carbonic acid and aniline. 

C 14 H 7 NO 4 = C 12 H 7 N + 2COI 
Nitrobenzole {which see) may be converted into aniline, either by the action of sulphu- 
retted hydrogen — 

C 12 H 5 NO 4 + 6HS = C 12 H 7 N + 4H0 -j- 6S; 

Nitrobenzole. Aniline, 

or, more conveniently, as has been recently shown by H. Bechamp, by the action of a basio 
acetate of iron. 

For this purpose the following proportions have been found convenient by the writer : 
mix in a retort J lb. of iron filings, with about 2 ounces of acetic acid, then add about an 
equal volume of nitrobenzole. After a few minutes a brisk effervescence sets in, and the 
aniline distils over together with water. The reaction may require to be aided by the 
application of a very gentle heat -, but it takes place with the greatest ease, and a very tol- 
erably sufficient condensing arrangement should be employed. The aniline having so nearly 
the density of water, does not readily separate on the surface, but the addition of a few 
drops of ether, which dissolves in the aniline, brings it to the surface. It may then be 
decanted off, dried by standing for a short time over chloride of calcium, and then purified 
by rectification, as before described. 

Properties. — Aniline is one of the organic basic derivatives of ammonia. In fact, it may 
be viewed as ammonia in which one equivalent of hydrogen is replaced by the compound 
radical Phenyl (C 12 H 5 ) thus ;— 

( C ,2 B? 
N \ H 
I H 
Just as phenyl is one of a series of homologous radicals, so aniline is the first of a series 
of homologous bases, in which the one equivalent of hydrogen is replaced by these radicals, 
respectively, thus : 

Homologous Radicals. Homologous Bases. 

Phenyl - - - C 12 H 5 — Aniline - - - N j 

Toluyl - - - C 14 H 7 — Toluidine - - - N j 

Xylyl - - - C 16 H 9 — Xylidine - - - N \ ° 

Cumyl - - - C« 3 H" — Cumidine - - - N j g 

Cymyl - - - C 20 H 13 — Cymidine - - - N j 

H 2 

C 14 H 7 
H 2 
H 9 

H 2 


H 2 


"When pure, it is a colorless liquid of a high refractive power ; density 1-028, and of an 
aromatic odor. It is slightly soluble in water, and mixes in all proportions with alcohol 
and ether. It boils at 360° F., (182° C.) It dissolves sulphur and phosphorus when cold, 
and coagulates albumen. It has no action on litmus-paper, but turns delicate vegetable 
colors, such as dahlia-petal infusion, blue. 

Its basic characters are well developed thus: — it precipitates the oxides from the salts 
of iron, zinc, and alumina, just like ammonia, and yields, with bichloride of platinum, a 
double salt similar to ammonia, the platino-chloride of aniline, (C 12 H' N, HC1, PtCl 2 ,) which 
on ignition is entirely decomposed, leaving only a residue of platinum. These characters, 
together with the beautiful blue color which it strikes with solution of bleaching powder, or 
the alkaline hypochlorites generally, are sufficient for the recognition and distinction of this 

Salts of Aniline. — Aniline combines with acids forming a long series of salts which 
are in every respect analogous to the corresponding salts of ammonia. They are nearly all 
soluble and crystallizable, and are decomposed by the mineral alkalies with liberation of ani- 
line. They are generally colorless, but become red by exposure to the air. 

Sulphate of Aniline. (C 12 H 7 N ; HO, SO 3 .)— This salt is employed in the manufacture 
of Mr. Perkitfs aniline colors. It is prepared by treating aniline with dilute sulphuric acid, 
and evaporating gently till the salt separates. It crystallizes from boiling alcohol in the 
form of beautiful colorless plates of a silvery lustre, for the salt is scarcely at all soluble in 
cold alcohol. It is very soluble in water, but insoluble in ether. 

The crystals redden by exposure to the air ; they can be heated to the boiling point of 



water without change, but when ignited they are charred with disengagement of aniline and 
sulphurous acid. 

Oxalate of Aniline. (C J2 H 7 N ; HO, C 1 O 3 .)— This is one of the best-defined salts of 
aniline : it separates as a crystalline mass on treating an alcoholic solution of oxalic acid 
with aniline. It is very soluble in hot water, much less so in cold, only slightly soluble in 
alcohol, and insoluble in ether. 

A large number of other salts are known. The hydroehlorate, hydrobromate, hydrio- 
date, nitrate, several phosphates, citrate, tartrate, &c. &c. ; but they are of purely scientific 
interest. The same remark applies to the various products of the decomposition of aniline, 
which have been so ably investigated by Fritzche, Zinin, Hofmann, Gerhardt, and other 

Application. — Several most beautiful colors for dyeing silk have been prepared by Mr. 
William H. Perkin, of Greenford Green, near Harrow, from certain salts of aniline, which 
are of different shades of violet, some more approaching purple, others more pink. They 
are now being extensively employed in dyeing silk, and are found to be far finer in tint, 
and more permanent, than any other known dyes of a similar color. The processes for 
their manufacture have been patented by Mr. Perkin. For the following short description 
of the method of preparing them, we are indebted to that gentleman : — 

" Take equivalent proportions of sulphate of aniline and bichromate of potash, dissolve 
them in water, mix, and allow the mixture to stand for several hours. The whole is then 
thrown upon a filter, and a black precipitate which has formed is washed and dried. It is 
then digested with coal-tar naphtha, to extract a brown resinous substance, and finally 
digested with alcohol to dissolve out the coloring matter, which is left behind on distilling 
off the spirit, as a coppery friable mass." — H. M. W. 

ANISEED. (Anis, Fr. ; Anis, Germ.) The fruit or^eed of the pimpinella aniswn, 
largely cultivated in Malta, Spain, and Germany ; used in the preparation of the oil of anise, 
(oleum anisi,) the spirit of anise, (spiritus anisi,) and anise water, [aqua anisi.) It is also 
used in cordials. In 1855, 963 cwts. were imported. The oleum badiani, or the oil of star 
anise, (illicium anisatum,) has the color and taste of the oil of anise ; but it preserves its 
fluidity at 35-6° F. It is sometimes fraudulently substituted for oleum anisi. — Pereira. 

ANTHRACITE. (&f0pa|, coal.) A variety of coal containing a larger proportion of 
earbon and less bituminous matter than common coal. — De la Beche. 

Anthracite coal is obtained in this country, at Bideford, in Devonshire, in the Western 
divisions of the South Wales coal-field, and in Ireland. It is found abundantly in America. 
, Professor H. D. Roger's " Transactions of American Geologists " states that in the great 
Appalachian coal-field, extending 720 miles, with a chief breadth of 180 miles, the coal is 
bituminous towards the western limit, where it is level and unbroken, becoming anthracitic 
towards the south-west, where it is disturbed. Anthracitic coal is also found in the coal- 
fields of France, especially in the departments of Isere, the High Alps, Gard, Mayenne, and 
of Sarth ; about 42,271,000 kilogrammes (of 2-2046 avoirdupois pounds each) are produced 
annually. Anthracite is also raised in Belgium. 

Anthracite is not an original variety of coal, but a modification of the same beds which 
remain bituminous in other parts of the region. Anthracite beds, therefore, are not sepa- 
rate deposits in another sea, nor coal measures in another area, nor interpolations among 
bituminous coals, but the bituminous beds themselves, altered into a natural coke, from 
which the volatile bituminous oils and gases have been driven off.—/. P. Lesley, on Coal. - 

Anthracite — now extensively used for iron-making, steam-engines, and for domestic pur- 
poses, in the United States — was, some 50 years since, regarded as incombustible refuse, 
and thrown away. 

This peculiar and valuable fossil fuel is found in various parts of the old and new con- 
tinent, as shown by the following lists, for which we are mainly indebted to the American 
publication, Statistics of Coal, by Taylor. 

Localities, of Anthracite and Anthracitous CoaL 
South Wales : — Swansea .... 

Cyfarthfa .... 

Yniscedwin - 
Average - 
Ireland, mean ...... 

France : — Allier ------ 


Brassac ..... 

Belgium : — Mons 

Westphalia ------- 

Prussian Saxony 

Saxony ------- 

Average of Europe - 


"Weight of a 



yard in lbs. 

1-263 - 



1-337 - 



1.354 - 



1-445 - 



1-445 - 



1-380 - 



1-390 - 



1-430 - 



1-307 - 

- ■ - 


1.305 - 



1-466 - 



1-300 - 





Localities of Anthracite and Anthracitous Coal, (continued.) 

Pennsylvania : — Lykens Valley - 

Lebanon co., gray vein 
Schuylkill co., Lorberry Creek 
Pottsville, Sharp Mountain - 
" Peach - 

" Salem Vein - 

Tamaqua, north vein - 
Mauch Chunk - 
Nesquehoning - 
Wilkesbarre, best 
West Mahoney - - - 
Beaver Meadow - - - 
Girardville - - - - 
Hazelton - - - - 
Broad Mountain - 
Lackawanna - 

Massachusetts : — Mansfield - - - - 
Ehode Island : — Portsmouth - 

Average in United States - - - - 
The calorific value of anthracite coal is well shown by the following results from Dr. 
Fyfe's experiments to compare Scotch and English bituminous coals with anthracite, in re- 
gard to their evaporative power, in a high-pressure boiler of a 4-horse engine, having a grate 
with 8-15 square feet of surface; also in a wagon-shaped copper boiler, open to the air, 
surface 18 feet, grate 1-55. 

1-327 - 

"Weight of a 

cubic yard in lbs 

- 2,240 

1-379 - 
1-472 - 



■ 1-412 - 



1-446 - 



■ 1-574 - 



■ 1-600 - 



1-550 - 



• 1-558 - 



• 1-472 - 



1-371 - 



1-600 - 



■ 1-600 - 



- 1-550 - 



■ 1-700 - 



- 1-609 - 



- 1-710 - 



- 1-810 - 



£ i 



3 O 

•a -^ 

S £ o • 

Kind of Fuel 

1 -= 


£ S 

£*! = 



t * fa o 


« a 
c ° 

g a 



11* - 


3 _■ 
ft. °* 

P. 1 o 

,- a* 
o ^ 
O - 

• S l° 

to 3 iS = 

5 bEfl 
ft. B. 


Middlerig Scotch 

Pressure 17 lbs. 


SI -33 








per sq. inch. 

Scotch coal, dif- 

ferent variety 

from preceding. 




6 62 






Anthracite - 










Scotch coal, from 

near Edinburgh 









Low pressure, open 

English bitumi- 

copper boiler. 

nous coal. 










Space will not admit of our entering fully into the question of the evaporative power of 
anthracite ; but its advantages under certain conditions are fully established. 

In this country anthracite coal is used in the manufacture of iron in the following fur- 
naces : — 

• Blast Furnaces making Iron from Anthracite. 


Names of Works. 


Furnaces built. 

Furnaces in 

Furnaces in 
blaBt in Dis- 




Aberdare, Abernant, and 

Banwen - 
Onllwyn or Brin - 
Tstalyfera ... 


Aberdare Iron Company 
Out of blast 
L. Llewellyn - 
Aberdare Iron Company - 
Tstalyfera Iron Company 







Abercrave - 
Tniscedwin ... 


T. "Walters 

Tniscedwin Iron Company 







Bryn Ammon 
Trim Saren - 

• Pembrokeshire. 

L. Llewellyn - 
T. "Watncy & Co. 
E. H. Thomas - 





Sandersfoot - 

Pembroke Iron and Coal Co. 

1 1 


Total furnace 

3 in blast in anthracite district 

s in 1S57 

- • 




Professor W. R. Johnson, of Pennsylvania College, informs us that fourteen furnaces 
using anthracite for the production of iron were in use in the United States. 
In the anthracite districts of South Wales, the produce was, in — 

1855 - - - 997,500 tons. 

1856 - - - 965,500 " 

1857 - - - 1,485,000 " 

The following table shows the progress of production in America of anthracite from 
1840 to 1857, inclusive, from Schuylkill, Lehigh, and Wyoming: — 



Increase per Tear. 






















































320,163 decrease. 

Pottsville Miners' Journal. 

A steady increase is thus shown in the production of American anthracite, excepting 
during the last year. This decrease may be readily accounted for by the general depression 
of the iron and other manufactures. 

The annual consumption of anthracite in the United States was thus stated in the 
Science of New York Exhibition : — 

1820 - 

1825 - 

1830 - 

1835 - 

1840 - 

1845 - 

1850 - 

1853 - 


330 tons. 

" 35,000 

" 176,000 

" 561,000 

" 865,000 

" 2,023,000 

" 3,357,000 

" 5,195,000 

The quantity consumed in 1856 is stated to have been 7,900,000 tons. 

ANTELOPE HORN is used occasionally for ornamental knife handles. See Horn. 

ANTICHLORE. A term employed by bleachers to the means of obviating the perni- 
cious after-effects of chlorine upon the pulp of paper, or stuffs, which have been bleached 
therewith. Manufacturers have been in the habit of using sulphite of soda, whose action 
upon the adhering bleaching salt, which cannot be removed by washing, gives rise to the 
formation of sulphate and hydrosulphate of soda and chloride of sodium. Chloride of tin 
has been recommended by some chemists for this purpose. 

been, from time to time, introduced for the purpose of removing, as much as possible, the 
friction of machinery. Black lead, or plumbago, mixed with a tenacious grease, has been 
much employed. Peroxide of iron, finely divided haematite, &c, have also been used. 

A composition employed at Munich is reported to have been used with success and 
economy to diminish friction of machinery. It consists of ten and a half parts of pure hogs' 
lard, fused with two parts of finely pulverized and sifted plumbago. The lard is first to be 
melted over a moderate fire, then a handful of the plumbago thrown in, and the materials 
stirred with a wooden spoon until the mixture is perfect ; the rest of the plumbago is then 
to be added, and again to be stirred until the substance is of uniform composition ; the ves- 
sel is then to be removed from the fire, the motion being continued until the mixture is 


quite cold. The composition, in its cold state, was applied to the pivots, the teeth of 
wheels, &c, by a brush, and seldom more than once in 24 hours.* 

It was found that this composition replaced the oil, tallow, and tar, in certain iron works 
with economy, saving about % of the cost of these articles. 

ANTI-FRICTION METAL. Tin and pewter are commonly employed as anti-friction 
metals for the bearings of locomotive engines. 

Babbet's metal is prepared by taking about fifty parts of tin, five of antimony, and one 
of copper. 

Tin or pewter, used alone, owing to its softness, spreads out and escapes under the 
superincumbent weight of the locomotive, or other heavy machinery. It is usual, there- 
fore, to add antimony, for the purpose of giving these metals hardness. 

Fenton's Anti-friction metal, which is much employed, is a mixture of tin, copper, and 
spelter. Its advantages are stated to be cheapness in first cost, low specific gravity, being 
20 per cent, lighter than gun metal ; and being of a more unctuous or soapy character than 
gun metal, less, grease or oil is required. 

The softer metal is often supported by brasses cast of the required form, the tin alloy 
being cast upon them. The brasses, or bearings, being properly tinned, and an exact model 
of the axle having been turned, the parts are heated, put together in their relative positions, 
luted with plastic clay, and the fluid anti-friction metal poured in, which then becomes of 
the required form, and effectually solders the brass. 

The following compositions are recommended to railway engineers as having been em- 
ployed for several years in Belgium : — In those cases where the objects are much exposed 
to friction, 20 parts of copper, 4 of tin, O'o of antimony, and - 25 of lead. For objects 
which are intended to resist violent shocks, 20 parts of copper, 6 of zinc, and 1 of tin. 
For those which are exposed to heat, 17 parts of copper, 1 of zinc, - 5 of tin, and - 25 of 
lead. The copper is added to the fused mass containing the other metals. 

ANTIMONY occurs with numerous ores of lead and silver, of nickel, &c, but the most 
important ore of antimony is the sulphuret, (Stibnite, or Gray Antimony,) which forms the 
chief and most common source of the antimony of commerce, and of the greater number 
of the pharmaceutical preparations of that metal. Antimony is not at present produced in 
this country, but in the last century it was mined extensively. 

The most celebrated localities of this ore are Falsobanya, Schemnitz, and Kremnitz, in 
Hungary, where it occurs in diverging prisms several inches long. It is also found in the 
Hartz, at Andreasberg, in Hungary, in Cornwall, at the old Trewetha mine, and abundantly 
in Borneo. 

This ore was called by the ancients ir\arv6(p8a\fj.ov — irAarvs, broad, o(p$a\/xhs, eye — from 
the use to which it was applied in increasing the apparent size of the eye, as is still prac- 
tised among oriental nations, by staining the upper and under edges of the eyelids. It was 
also used as a hair-dye and to color the eyebrows. 

It was the Lupus Metallorum of the alchemists. Crude antimony is obtained from it by 
simple fusion, and from this product the pure metal is extracted. 

The other principal ores of antimony are the following : — 

Native Antimony is a mineral of a tin-white color and streak and a metallic lustre, and 
sometimes contains silver, iron, and arsenic, with which last it is commonly associated. It 
is brittle, and possesses a specific gravity of 6-62 to 6-'72. It is generally lamellar, some- 
times botryoidal, or reniform. Before the blowpipe; it soon melts, and continues to burn 
after the heat is removed ; but if the heat be continued, it evaporates in white fumes, and is 
redeposited round the globule. 

Native antimony occurs at Sahlburg in Sweden, Andreasberg in the Hartz, Allemont in 
Dauphiny, in Mexico, &c. 

Arsenical Antimony also occurs at Allemont, in the Hartz, and elsewhere, in reniform 
and amorphous masses, with a finely granular or a curved lamellar structure. It is com- 
posed of arsenic 62"15, antimony 5*7"85. It possesses a metallic lustre, and a reddish-gray 
or tin-white lustre. Its specific gravity is 6 '2. 

Oxide of Antimony (Cervantite) occurs, associated with gray antimony, (of which it is 
an altered form,) at Cervantes, in Spain, in Hungary, and the Auvergne. It is found in 
octahedral crystals, and in radiating fibrous crystals in the province of Constantina, in Alge- 
ria, (Senannontite,) also at Perneck, in Hungary. It occurs as a crust or powder, or in 
acicular crystals, with a greasy or earthy lustre, and of a pale yellow or nearly white color. 
Specific gravity = 40'8. It is composed of antimony 80-1, oxygen 19'9 ; but frequently it 
contains an admixture of iron, carbonate of lime, &c. It is soluble in muriatic acid. 

White Antimony ( Valentiniie) is the result of the alteration of gray antimony, native 
antimony, and other ores of that metal. It possesses a shining pearly lustre and a snow- 
white color, but is sometimes pinkish, or ash-gray, or brownish. It affords a white streak. 
It is composed of antimony 84-32, oxygen 15 '68. Specific gravity = 5 '56. It is found in 
tabular crystals in veins traversing the primary rocks at Prizbram in Bohemia, near Frey- 
berg in Saxony, Allemont in Dauphiny, &c. 

* Ann. des Mines, xi. 79. 



Red Antimony (Kermesite) is a compound of oxide of antimony 30-2, and sulphide of 
antimony 69-8, or antimony 74 '45, oxygen 5-29, and sulphur 20-49. 

It occurs generally in capillary six-sided prismatic crystals of a cherry-red color, afford- 
ing a brownish-red streak. It has a specific gravity of from 4-5 to 4'6. 

It is feebly translucent, and possesses an adamantine lustre. It occurs at Walaezka in 
Hungary, Braunsdorf in Saxony, and at Allemont in Dauphiny. 

At Malboac, in the department of Ar- 
deche, in France, the separation of the sulphide 
of antimony from its associated gangue is 
effected by means of a peculiar apparatus, ( fig. 
39.) The mineral is placed in large retorts, 
e e, of which four are set in each furnace. 
An aperture is left at the bottom of each of 
these cylinders, which corresponds with a sim- 
ilar opening by which they are supported. 
Beneath these, in the chambers c c, are placed 
earthen pots, p p, in which is received the 
melted sulphide as it descends through the 
openings in the cylinders. The fuel consumed 
on the grate consists of fir wood ; and the sul- 
phide obtained is converted into metallic anti- 
mony by roasting in a reverberatory furnace, 
and subsequent reduction by a mixture of 20 
per cent, of powdered charcoal which has 
been saturated with a strong solution of the 
carbonate of soda. 

Melted with tin, antimony has of late been used as an anti-friction alloy for railway 
axles, and other bearings ; in metallic rings, or collars, for machinery. As this alloy is not 
so much heated by friction as the harder metals, less grease is consumed. 

ANTIMONY, GLASS OF. This substance, according to M. Soubeiran, contains — 

Protoxide of antimony 91 '5 

Silica - 4-5 

Peroxide of iron -- 3-2 

Sulphuret of antimony 19 


APPLE WINE. Cider. Winckler finds that the wine from apples is distinguished 
from the wine from grapes by the absence of bitartrate of potash and of aenanthic acid, by 
its containing a smaller amount of alcohol and more tannin, but especially by the presence 
of a characteristic acid, which he regards as lactic acid, notwithstanding that this opinion is 
not confirmed by the degree of solubility of its salts with oxide of zinc, lime, and magnesia. 
See Cider, vol. i., p. 561. 

AQUAFORTIS. This acid has usually been obtained by mixing common nitre with 
green vitriol or sulphate of iron, and distilling, or by mixing nitre and clay or siliceous 
matter, and distilling over the nitric acid, leaving the alkali to unite with the earthy base. 

It may, however, be usefully borne in mind, that this term of aquafortis, or strong 
water of the old chemist, was also applied to solutions which answered their special pur- 
poses. Thus Salmon, in 1685, gives the composition of aquafortis from certain mixtures 
of acids, not nitric, and salts, and distinctly refers to the Pharmacopoeia for the other kind. 
This may be of service when applying old recipes for processes in the arts. Aquafortis did 
not always mean nitric acid. See Nitric Acid. 

AQUAMARINE is the name given to those varieties of beryl which are of clear shades 
of sky-blue or greenish-blue, like the sky. It longitudinally-striated hexagonal crys- 
tals, sometimes a foot long, and is found in the Brazils, Hindostan, and Siberia. See Beryl. 

AQUA REGIA. Royal water. Now called nitro-muriatic acid, or nitro-chlorohydric 
acid, or hypochloro-nitric acid. 

Prepared under different conditions, it appears to give different results. Gay-Lussac 
observed that aqua regia, when heated in a water-bath, evolves a gaseous-body which, dried 
and exposed to a frigorific mixture, separates into chlorine and a dark lemon-yellow liquid, 
boiling at *70° F. This yellow liquid was found to contain 69 "4 per cent, of chlorine, the 
calculated quantity for the formula, N0 2 CP, being '70-2. Gay-Lussac refutes the assertion 
of E. Davy and Baudrimont, that the properties of aqua regia are due to its containing a 
compound of chlorine, nitrogen, and oxygen, and confirms the generally received view, that 
its action depends upon free chlorine. From the vapor evolved in the action of aqua regia 
upon gold, a liquid may be condensed which is nearly of the composition N0 2 C1 2 , contain- 
ing, however, no free chlorine. 

ARABIC, GUM. Chemists have been disposed to divide gums into three varieties, to 
which they have given the names of Arabine, cerasine, and dextrine.' 



Arabine, or gum Arabic, exudes from several species of acacia and prunus ; it is aleo 
found in the roots of the mallow, comfrey, and some other plants. Gum Arabic never crys- 
tallizes, is transparent, and has a vitreous fracture. It dissolves in water in all proportions, 
forminc mucilage. Its chemical composition is expressed by the formula, C'WO". 

ARCH. As this dictionary is not intended to include articles connected with engineering 
or with architecture, it would be out of place to describe the conditions required to ensure 
the stability of the arch, which is manifestly one of great importance to the practical builder. 
(For the theory of the equilibrium of the arch, Gwilt's treatise on the subject should be con- 
sulted, or the article Arch, " Encyclopaedia Britannica.") 

ARCHIL. (Orseille, Fr. ; Orseille, Germ. ; Oricello, Ital.) The name of archil is 
given to a coloring matter obtained, by the simultaneous action of the air, moisture, and an 
ammoniacal liquor, from many of the lichens, the most esteemed being the lichen roccclla. 

It appears in commerce in three forms: 1, As a pasty matter called archil; 2, as a 
mass of a drier character, named persis; and 3, as a reddish powder called cudbear. 

The lichen from which archil is prepared is known also as the canary weed or orchilla 
weed. It tows in great abundance on some of the islands near the African coast, particu- 
larly in the Canaries and several of the Islands of the Archipelago. Its color is sometimes 
a light and sometimes a dark gray. 

The chemical constitution of archil was first investigated by M. Cocq, " Annales de 
Chimie," vol. lxxxi. ; and subsequently, yet more extensively, by Robiquet, " Annales de 
Chimie," vol. xlii., 2d series. 

From the Variolaria, Robiquet obtained Orcine, by digesting the lichen in alcohol, 
evaporating to dryness, dissolving the extract in water, concentrating the solution to the 
thickness of a syrup, and setting it aside to crystallize. It forms, when quite pure, color- 
less prisms, of a nauseous sweet taste, which fuse easily, and may be sublimed unaltered. 
Its formula is C"'H"0 J -(- 3 Aq. when sublimed ; when crystallized from its aqueous solution 
it contains 5 Aq. 

If orcine be exposed to the combined action of air and ammonia, it is converted into a 
crimson powder orceine, which is the most important ingredient in the archil of commerce. 
Orceine may be obtained by digesting dried archil in strong alcohol, evaporating the solu- 
tion in a water-bath to dryness, and treating it with ether as long as any thing is dissolved ; 
it remains as a dark blood-red powder, being sparingly soluble in water or ether, but abun- 
dantly in alcohol. Its formula is C 10 H 9 NO 7 . 

Orceine dissolves in alkaline liquors with a magnificent purple color ; with metallic 
oxides it forms lakes, also of rich purple of various shades. In contact with deoxidizing 
agents, it combines with hydrogen, as indigo does, and forms leuc-orceine, C^H'NO 7 -j- H. 
When bleached by chlorine, a yellow substance is formed, cAZo?--orceine, the formula of 
which is C 1G H 9 N0 7 -(- CI analogous to the other. — Kane. 

Dr. Schunk, by an examination of several species of Lecanora, has proved that, although 
under the influence of ammonia and of air, they ultimately produce orceine, these lichens 
do not contain orcine ready formed, but another body, Lecanorine, which, under the influ- 
ence of bases, acts as an acid, and is decomposed into ■ orcine, and carbonic acid. If 
lecanoric acid be dissolved in boiling alcohol, it unites with ether, forming lecanoric ether, 
which crystallizes beautifully in pearly scales. In the roccella tinctoria and the evernia 
prunattri. erytheric acid is found. By the oxidation of this acid amaryihrine or crythrine 
bitter is formed. These substances have been carefully examined by Schunk, Stenhouse, 
and Kane. The chemical history of these and some other compounds is of great interest ; 
but as they do not bear directly upon the manufacture of archil, or its use in dyeing, fur- 
ther space cannot be devoted to their consideration. 

Kane found archil and litmus of commerce to contain two classes of coloring matters, 
as already stated, orcine and orceine, derived from it. Beyond these there were two bodies, 
one containing nitrogen, azoerythrine, and the other destitute of nitrogen, erythrolcic acid. 
This latter acid is separated from the other bodies present in archil by means of ether, in 
which it dissolves abundantly, forming a rich crimson solution. It gives with alkalies 
purple liquors, and with earthy and metallic salts colored lakes. 

Beyond those already named there are several other species of lichen which might be 
employed in producing an analogous dye, were they prepared, like the preceding, into the 
substance called archil. Hellot gives the following method io; discovering if they possess 
this property : — A little of the plant is to be put into a glass vessel ; it is to be moistened 
with ammonia and lime-water in equal parts ; a little muriate of ammonia (sal ammoniac) is 
added, and the small vessel is corked. If the plant be of a nature to afford a red dye, after 
three or four days the small portion of liquid which will run off on inclining the vessel, 
now opened, will be tinged of a crimson red, and the plant itself will have assumed this 
color. If the liquor or the plant does not take this color, nothing need be hoped for ; and 
it is useless to attempt its preparation on the great scale. Lewis says, however, that lie has 
tested in this way a great many mosses, and that most of them afforded him a yellow or 
reddish-brown color ; but that he obtained from only a small number a liquor of a deep red, 
which communicated to cloth merely a yellowish-red color. 


To prepare archil, the lichens employed are ground up with water to a uniform pulp, 
and this is then mixed with as much water as will make the whole fluid ; ammoniacal liquors 
from gas or from ivory-black works, or stale urine, are from time to time added, and the 
mass frequently stirred so as to promote the action of the air. The orcine or erythrine 
which exists in the lichen absorbs oxygen and nitrogen, and forms orceine. The roccelline 
absorbs oxygen and forms crythrolcic acid ; these being kept in solution by the ammonia, the 
whole liquid becomes of an intense purple, and constitutes ordinary archil. — Kane. 

The herb archil, just named, called especially orceille de ierre, is found upon the vol- 
canic rocks of the Auvergne, on the Alps, and the Pyrenees. 

These lichens are gathered by men whose whole time is thus occupied ; they scrape them 
from the rocks with a peculiarly shaped knife. They prefer collecting the orceille in rainy 
weather, when they are more easily detached from the rocks. They gather about 2 kilo- 
grammes a day, or about 4i pounds. When they take their lichens to the makers of archil 
or litmus for the purpose of selling them, they submit a sample to a test, for the purpose 
of estimating their quality. To this end they put a little in a glass containing some urine, 
with a small quantity of lime. As the lichens very rapidly pass into fermentation if kept in 
a damp state, and thus lose much of their tinctorial power, great care is taken in drying 
them ; when dry they may be preserved without injury for some time. 

AREOMETER. An instrument to measure the densities of liquids. (See Alcoholom- 
etrt.) The principle will be well understood by remembering that any solid body will sink 
further in a light liquid than in a heavy one. The areometer is usually a glass tube, having 
a small glass bulb loaded with either shot or quicksilver, so as to set the tube upright in any 
fluid in which it will swim. Within the tube is placed a graduated scale : we will suppose 
the tube placed in distilled water, and the line cut by the surface of the fluid to be marked ; 
that it is then removed and placed in strong alcohol — the tube will sink much lower in this, 
and consequently we shall have two extremities of an arbitrary scale, on which we can mark 
any intermediate degrees. 

ARNATTO, or ARNOTTO. See Annotto, vol. i. Arnatto was considered to contain 
two distinct coloring matters, a yellow and red, till it was shown by M. Pressier that one is 
the oxide of the other, and that they may be obtained by adding a salt of lead to a solution 
of arnatto, which precipitates the coloring matter. The lead is separated by sulphuretted 
hydrogen ; and the substance being filtered and evaporated, the coloring matter is deposited 
in small crystals of a yellow-white color. These crystals consist of bixine ; they become 
yellow by exposure to the air, but if they are dissolved in water they undergo no change. 
When ammonia is added to bixine, with free contact of air, there is formed a fine deep red 
color, like arnatto, and a new substance, called bixeine, is produced, which does not crys- 
tallize, but may be obtained as a red powder ; this is colored blue by sulphuric acid, and 
combines with alkalies, and is bixine with addition of oxygen. When arnatto, in the form 
of paste, is mixed from time to time with stale urine, it appears probable that the improve- 
ment consists in the formation of bixeine from the bixine by the ammonia of the urine. It 
has hence been suggested that, to improve the color of arnatto, it might be mixed with a 
little ammonia, and subsequently exposed to the air, previously to its being used for dyeing. 

A solution of arnatto and potash in water is sold under the name of Scott's Nankeen 

ARROBA (of wine). A Spanish measure, equal to 3-5517 gallons. 

ARROW ROOT. In commerce, the term arrow root is frequently used generically to 
indicate a starch or fecula, as Portland arrow root, a white amylaceous powder, prepared 
in the Isle of Portland, from the Arum vulgare, the common Cuckoo-pint, called also Wake- 
robin and Lords and Ladies. 

East India arrow root, prepared from the Curcuma angustifolia. 

Brazilian arrow root, the fecula of Jatropha manihot. 

English arrow root, the starch of the potato. 

Tahiti arrow root, the fecula of Tacca oceanica, which is imported into London and sold 
as " arrow root prepared by the native converts at the missionary stations in the South Sea 

ARSENIC, derived from the Greek apo-eviichu, masculine, applied to orpiments on ac- 
count of its potent powers. This metal occurs native in veins, in crystalline rocks, and the 
older schists ; it is found in the state of oxide, and also combined with sulphur under the 
improper name of yellow and red arsenic, or orpiment and realgar. Arsenic is associated 
with a great many metallic ores ; but it is chiefly extracted in this country from those of tin, 
by roasting, in which case the white oxide of arsenic, or, more correctly, the arsenious acid 
is obtained. On the Continent, arsenical cobalt is the chief source of arsenic. 

The following are the principal ores of arsenic : — 

Native Arsenic. — The most common form of native arsenic is reniform and stalactitic 
masses, often mammillated, and splitting off in thin successive, layers like those of a shell. 
It possesses a somewhat metallic lustre, and a tin-white color and streak, which soon tar- 
nishes to a dark gray. Its specific gravity is 5 - 93. Before the blow-pipe it gives out an 



alliaceous odor, and volatilizes in white fumes. It is found in the Hartz, in Andreasberg, at 
the silver mines of Freiberg, in Chili, the Asturias, &c. 

White Arsenic, or Arsenious Acid, (Arsenolite,) is often formed by the decomposition 
of other arsenical ores, and is composed of arsenic 65-16 and oxygen 24-24. It occurs either 
in minute radiating capillary crystals and crusts investing other substances, or in a stalactitic 
or botryoidal form. Before the blow-pipe it volatilizes in white fumes ; in the inner flame 
it blackens and gives out an alliaceous odor ; its specific gravity is 3-69. It is white, some- 
times with a yellowish or reddish tinge, and has a silky or vitreous lustre. It possesses an 
astringent, sweetish taste. — H. TV. B. 

Realgar, (ancienty called Sandaraea,) red orpiment, or ruby sulphur, is a sulphide of 
arsenic, having a composition, sulphur 29-91, arsenic 10-09. It occurs in Hungary, Saxony, 
and Switzerland. 

Orpiment, (a corruption of its Latin name, aurigmentum — golden paint,) yellow sulphide 
of arsenic : its composition is, sulphur 39, arsenic 61. Burns with a blue flame on char- 
coal, and emits fumes of sulphur and arsenic. Dissolves in nitromuriatic acid and am- 

Both realgar and orpiment are artificially prepared and used as pigments. See those 

Arsenic is a brittle metal, of an iron-gray color, with a good deal of brilliancy. It may 
be prepared by triturating arsenious acid, or the white arsenic of commerce, with black flux, 
(charcoal and carbonate of potash,) and subliming in a tube. If arsenical pyrites are ignited 
in close tubes, metallic arsenic sublimes, and sulphuret of iron remains. This metal, when 
exposed in the air, gradually absorbs oxygen, and falls into a gray powder, (suboxide.) This 
is sold on the Continent as fly powder. 

To prepare arsenic on a larger scale, mispickel, or the other ores employed, are pounded; 
some pieces of old iron are mixed with the ore, to retain the combined sulphur, and the 
mixture placed in retorts between four and five feet in length, to which receivers are 
adapted. The retorts are moderately heated by a fire placed beneath them ; the ores are 
decomposed, and metallic arsenic is sublimed and condensed in the receivers. The arsenic 
obtained in this way is purified by a second distillation with a little charcoal. 

Arsenic is used in small quantities in, the preparation of several alloys ; it is employed 
in the manufacture of opal glass ; also is much used in the manufacture of shot, to which it 
imparts a certain degree of hardness ; and, by preventing the distortion of the falling drops 
of metal, and thus securing regular globules, the manufacture is greatly facilitated. 

ARSENIOUS ACID, While Arsenic, Flowers of Arsenic. — This is the white arsenic of 
commerce, usually called Arsenic. It is obtained in this country from the arsenical ores of 
iron, tin, &c, and on the Continent from those of cobalt and nickel. It is prepared by 
heating the ores containing arsenic on the sole of a reverberatory furnace, through which a 
current of air, after passing through the grate, is allowed to play. The following ores are 
the more remarkable of this class, — the quantity of arsenic in 100 grains is given in each 
case : — 

Mispickel, or arsenical iron - 
Lblingite, arsenical pyrites 
Kupfer nickel, arsenical nickel 
Rammelsbergite, white arsenical nickel 
Smalline, tin-white cobalt 
Sajlorite, arsenical cobalt 




In the roasting of tin ores, a considerable quantity of arsenious acid is collected in the 
flues leading from the furnaces in which this process is effected. 

White arsenic is extensively used in the preparation of various pigments, as the bisul- 
phide, or realgar, the tersulphide, or orpiment, and also in the mineral greens used by 
paper-stainers. It is employed in glass and porcelain manufacture. Considerable discus- 
sion has arisen from a statement made by Mr. A. S. Taylor, that the arsenic employed in 
paper-hangings was removed at the ordinary temperatures of our rooms, and that many 
injurious effects had resulted from the use of such paper. Although, under some circum- 
stances, it is possible that portions of the arsenic may escape as dust from the wall of a 
room, experience appears against its exerting any injurious effects. Even the men employed 
in burning-houses, where they are necessarily exposed to the escaping oxide, do not appear 
to suffer in health. The following letter, published by Mr. Alfred E. Fletcher, is much to 
the point : — 

" The color principally referred to is the aceto-arsenite of copper, commercially known 
as emerald green. The chief advantage which this color possesses over other of a similar 
tint is that, besides having greater brilliancy, it is quite permanent. The color, when ex- 
posed to the air for any length of time, does not fade in tint nor lessen in intensity, which 
would necessarily be the case did any evaporation of its constituent parts take place, though 
in the smallest degree, especially as the layer of color exposed is often extremely thin. 


Were it true that such evaporation or dissemination went on, it would indeed afford just 
cause of alarm, when we reflect that on the walls of houses in this country are displayed 
some hundred millions of square yards of paper, most of which carries on its surface a por- 
tion of arsenical coloring matter ; our books are bound with paper and cloth so colored, 
cottons and silks, woollen fabrics and leather, are alike loaded with it. Now, it is stated 
that in a medical work an instance is noted in which injury has been received by those liv- 
ing in rooms decorated with these colors : surely, were the proximity of such materials inju- 
rious, it would not be necessary to search in recondite books for the registry of isolated 
cases. The fact of the large extent to which such materials have always been employed is 
a sufficient proof that there is no danger attending their use ; moreover, workmen who 
have been daily employed for many years in manufacturing large quantities of these colors, 
under the necessity of constantly handling them, are in the regular enjoyment of perfect 
health, though exposed also to the general influences of a chemical factory. Let blame be 
laid at the right door, and let the public be assured that it is not the looking at cheerful 
walls, the fingering of brightly ornamented books, nor the wearing of tastefully colored 
clothing, that will hurt them, but the dwelling in ill-ventilated rooms." 

Arsenic, Poisoning by. — This poisoning is so commonly the cause of death, by acci- 
dent and by design, that it is important to name an antidote which has been employed with 
very great success. 

This is the hydrated peroxide of iron. This preparation has no action on the system, 
and it may therefore be administered as largely and as quickly as possible. The following 
statement will render the action of this hydrated salt intelligible. When hydrated peroxide 
of iron is mixed in a thin paste with the solution .of arsenious acid, this disappears, being 
changed into arsenic acid, (a far less active oxide,) and the iron into protoxide 2 Fe 2 2 and 
AsO 3 , producing 4 FeO -j- A e 5 . The hydrated peroxide of iron may be made in a few min- 
utes by adding carbonate of soda to any salt of the red oxide of iron, (permuriate, muriate, 
acetate, &c.) It need not be washed, as the liquor contains only a salt of soda, which would 
be, if not beneficial, certainly not injurious. — Kane. 

Detection of Arsenic in Cases of Poisoning. 

Arsenious acid, which is almost always the form in which the arsenic has entered the 
system, possesses the power of preventing the putrefaction of animal substances ; and 
hence the bodies of persons that have been poisoned by it do not readily putrefy. The 
arsenious acid combines with the fatty and albuminous tissues to form solid compounds, 
which are not susceptible of alteration under ordinary circumstances. It hence has fre- 
quently occurred that the bodies of persons poisoned by arsenic have been found, long after 
death, scarcely at all decomposed ; and even where the general mass of the body had com- 
pletely disappeared, the stomach and intestines had remained preserved by the arsenious 
acid which had combined with them, and by its detection the crimes committed many years 
before have been brought to light and punished. — Kane. 

The presence of arsenic may be determined by one of the following methods : — 

1. Portions of the contents of the stomach or bowels being gently heated in a glass tube, 
open at both ends, the arsenic, if in any quantity, will be sublimed, and collected as minute 
brilliant octahedrons. 

2. Or by the presence of organic matter ; if the ignition is effected in a tube closed at 
one end, metallic arsenic sublimes, forming a steel-gray coat, and emitting a strong smell 
of garlic. 

3. Ammonia Nitrate of Silver produces a canary-yellow precipitate from a solution of 
arsenious acid, (arsenite of silver.) The phosphate of soda produces a yellow precipitate 
of tribasic phosphate of silver, which exactly resembles the arsenite. The phosphate is, 
however, the more soluble in ammonia, and when heated gives no volatile product ; while 
the arsenite is decomposed with white arsenic and oxygen, leaving metallic silver behind. 

4. Ammonia Sulphate of Copper produces a fine apple-green precipitate, which is dis- 
solved in an excess of either acid or ammonia. It is, however, uncertain, unless the pre- 
cipitate be dried and reduced. 

5. The Reduction Test. — Any portion of the suspected matter, being dried, is mixed 
with equal parts of cyanide of potassium and carbonate of potash, both dry. This mixture 
is to be introduced into a tube terminating in a bulb, to which heat is applied, when metallic 
arsenic sublimes. 

6. MarsKs Test. — This is one of the most delicate and useful of tests for this poison, 
and when performed with due care there is little liability to error. The liquid contents of 
the stomach, or any solution obtained by boiling the contents, is freed as much as possible 
from animal matter by any of the well-known methods for doing so. This fluid is then ren- 
dered moderately acid by sulphuric acid, and introduced into a bottle properly arranged. 

Fig. 40 is the best form for Marsh's apparatus : — a is a bottle capable of holding half, 
or, at most, a pint. Both necks are fitted with new perforated corks, which must be per- 
fectly tight. Through one of these the funnel tube, b, is passed air-tight, and through the 



other the bent tube, c, which is expanded at/ into a bulb about an inch in diameter. This 
bulb serves to collect the particles of liquid which are thrown up from the contents of the 
bottle, and which drop again into 

the latter from the end of the .q 

tube. The other end of the tube 
is connected, by means of a cork, 
with tube d, about six inches long, 
which is filled with fused chloride 
of calcium, free from powder, 
destined to retain the moisture. 
In the opposite end of the tube d 
is fixed, air-tight, another tube, e, 
made of glass free from lead, 12 
inches long, and, at most, V12 of 
an inch in internal diameter. It 
must be observed that the funnel 
tube b is indispensably necessary 
to introduce the fluid to the pieces 
of perfectly pure metallic zinc 
already placed in the bottle. Hy- 
drogen gas is at once formed, and 

if arsenic is present, in even the smallest quantity, it combines with the hydrogen, and 
(gaseous arseniuretted hydrogen) escapes. If the gas as it issues from the jet is set on fire, 
no product but water is generated if the hydrogen is pure ; and by holding against the 
flame a cold white porcelain basin, or piece of glass, or of mica, no steam is produced, and 
a dew is formed upon the cold surface. If arsenic be present, a deposit is obtained, which, 
according to the part of the flame in which the substance to receive it is placed, will be 
either a brown stain of metallic arsenic, or a white one of arsenious acid. If the quantity 
of arsenic is too small to be detected in this way, it will be well to ignite the horizontal part 
of the tube. All the arseniuretted hydrogen will, in passing that point, become decom- 
posed, and deposit its arsenic. The heat will drive this forward, and a little beyond the 
heated portion metallic arsenic will be condensed. Several precautions are necessary to be 
observed ; but for the details of those we must refer to works especially directed to the 
consideration of this subject. One source of error must, however, be alluded to. A com- 
pound of antimony and hydrogen is formed under similar circumstances ; and this gas in 
many respects resembles the compound of arsenic and hydrogen. If the stain formed by 
the flame is -arsenic, it will dissolve, when heated, in a drop or two of sulpho-hydride of 
ammonia, and a lemon-yellow spot is left ; if antimony is present, it leaves a yellow stain. 
— Wohler. 

V. Fleitmann 's Test. — If a solution containing arsenic be mixed with a large excess of 
concentrated solution of potassa, and boiled with fragments of granulated zinc, arseniu- 
retted hydrogen is evolved, and may be easily reorganized by allowing it to pass on to a 
piece of filter paper spotted over with solution of nitrate of silver. These spots assume a 
purplish-black color, even when a small quantity of arsenic is present. This experiment 
may be performed in a small flask, furnished with a perforated cork carrying a piece of 
glass tube of about -J- inch diameter. It will be observed that this test serves to distinguish 
arsenic from antimony. 

The following remarks on the Toxicological Discovery of Arsenic deserve attention : — 

This active and easily administered poison is fortunately one of those most easily and 
certainly discovered ; but the processes require great precaution to prevent mistaken infer- 
ences : if due care is taken, arsenic can be found after any lapse of time, as well as after 
the most complete putrefaction of the animal remains. The longest time after which it has 
been discovered by myself is eight years, which was the case of an infant ; nothing but the 
bones of the skeleton remained, the coffin was full of earth, and large roots of a tree had 
grown through it. The metal was obtained from the bones, and in the earth immediately 
below where the stomach had existed. Many cases have occurred in my experience, where 
one, two, three, four, and five years have elapsed ; in one case after fourteen months, where 
the body of a boy had been floating in a coffin full of water. The poison is given in one 
of three states, white arsenious acid, yellow sulphuret ("orpiment") or "realgar," red 
sulphuret of arsenic ; and it is worthy of notice, that putrefaction will turn either white or 
red into yellow, but will never turn yellow into either white or red ; this is owing to the 
hydrosulphuret of ammonia disengaged during decomposition. 

Modern toxicologists have abandoned all the old processes for the detection of this poi- 
son, and have adopted one of two, which have been found more expeditious, as well as 
more certain. The first was proposed by Marsh, flf Woolwich : it is founded upon the 
principle that nascent hydrogen will absorb and carry off any arsenic which may be pres- 
ent, as arseniuretted hydrogen ; but as I prefer the principle first proposed by Eeinsch, and 



have always acted upon it, I shall confine my description to the processes founded upon it. 
The principle is this : arsenic mixed or combined with any organic matter will, if boiled 
with pure hydrochloric acid and metallic copper, be deposited upon the copper ; but as this 
depositing property is also possessed by mercury, antimony, bismuth, lead, and tellurium, 
subsequent operations are required to discriminate between the deposits. I take pieces of 
copper wire, about No. 13 size, and 2-^ inches long; these I hammer on a polished plane 
with a polished hammer, for half their length, (Jig. 41,) and having brought the suspected 
.. matters to a state of dryness, and boiled 

the copper blade in the pure hydrochloric 
acid, to prove that it contains no metal ca- 
pable of depositing, I introduce a portion 
of the suspected matter and continue the boiling ; if the copper becomes now either steel- 
gray, blue, or black, I remove it, and wash it free of grease in another vessel in which 
there is hot diluted hydrochloric acid ; I now dry it, and, with a scraper with a fine edge, 
take off the deposit with some of the adhering copper, and repeat the boiling, washing, and 
scraping, so as to have four or five specimens on copper ; one of these is sealed up her- 
metically in a tube for future production. I now take a piece of glass tube, and having 
heated it in the middle, draw it out, as in fg. 42, dividing it at 
a, each section being about 2 inches long, the wide orifices being 
about 3 /io of an inch in diameter, and ■£ an inch long, the capil- 
lary part V 8 of an inch in diameter, and 1£ inch long ; now, by 
putting one portion of the scrapings into one of the tubes at b, 
and holding it upwards over a very small flame, so that the vola- 
tile products may slowly ascend into the narrow portion of the tube, we prove the nature 
of the deposit : if mercury, it condenses in minute white shining globules ; if lead or bis- 
muth, it does not rise, but melts into a yellowish glass, which adheres to the copper ; if 
tellurium, it would fall as a white amorphous powder ; if antimony, it would not rise at 
that low temperature ; but arsenious acid condenses as minute octahedral crystals, looking 
with the microscope like very transparent grains of sand. I make three such sublimates, 
one of which is sealed up like the arsenic for future production. I now cut the capillary 
part of another of the tubes in pieces, and boil it in a few drops (say 10) of distilled water, 
and when cold drop three or four drops on a plate of white porcelain, and with a glass rod 
drop one drop of ammoniacal sulphate of copper in it : and now to make the colors from 
this and the next test more conspicuous, I keep a chalk stone, planed and cleaned, in readi- 
ness, and placing on it a bit of clean white filtering paper, I conduct the drops of copper 
test upon the paper, which permits the excess of copper solution to pass through into the 
chalk, but retains the smallest proportion of Scheele's green ; the other few drops of the 
solution are treated the same way with the ammoniacal nitrate of silver. When I get the 
yellow precipitate of arsenite of silver, the papers, with these two spots, are now dried and 
sealed up in a tube as before, and that with the silver must be kept in the dark, or it will 
become black. I have still one of the tubes with the arsenical sublimate remaining ; 
through this I direct a stream of hydrosulphuric acid gas for a few seconds, which converts 
the sublimate into yellow orpiment. I have now all five tests : the metal, the acid, arsenite 
of copper, arsenite of silver, and yellow sulphuret ; and the Viooooo of a grain of arsenic is 
sufficient in adroit hands to produce the whole ; but all five must be present, or there is no 
positive proof, for many matters will cause a darkness of the copper in the absence of 
arsenic, — sulphurets even from putrefaction ; — but there is no sublimate in the second 
operation, because the sulphur burns into sulphurous acid and passes off upwards. Corn, 
grasses, and earth slightly darken it from some unknown cause, but produce no sublimate ; 
so, if the solution of suspected arsenious acid is tested with the copper test while hot, it 
will produce a greenish deposit of oxide of copper, through the heat dissipating a little 
ammonia, or if the copper blade has not been deprived of grease by the diluted hydro- 
chloric acid, the sublimed acid from the grease will precipitate copper from that test ; but 
as much of the sulphuric acid of commerce, and nearly all such hydrochloric acid and some 
commercial zinc contain arsenic, nothing can excuse a toxicologist who attempts to try for 
arsenic if he has not previously experimented with all his reagents before he introduces the 
suspected matters. I should also mention that this metal is to be found in all parts of the 
body, but longest, and in greatest quantity, in the liver, where it is frequently found many 
days after it has disappeared from the intestines. — W. Herapath. 

Arsenious acid of commerce is frequently adulterated with chalk or plaster of Paris. 
These impurities are very easily detected, and their proportions estimated. Arsenious acid 
is entirely volatilized b'y heat, consequently it is sufficient to expose a weighed quantity of 
the substance to a temperature of about 400° F. in a capsule or crucible. The whole of 
the arsenic will pass off in fumes, while the impurities will be left behind as a fixed 
residuum, which can, upon cooling, be^eighed. 

It is scarcely necessary to state that, the fumes of arsenic being very poisonous, the 
volatilization should be carried on under a chimney having a good draught. 


Our Imports of Arsenic were as follows : — 

1855 73 ewts. 

1856 163 " 

ARTESIAN WELLS. The most remarkable example of an Artesian well is that at 
the abattoir of Grenelle, a suburb of the southwest of Paris, where there was a great want 
of water. It cost eight years of difficult labor to perforate. The geological strata round 
t!u French capital are all of the tertiary class, and constitute a basin similar, in most re- 
spects, to that upon which London stands. The surface at Grenelle consists of gravel, 
pebbles, and fragments of rocks, which have been deposited by the waters at some period 
anterior to any historical record. Below this layer of detritus, it was known to the engi- 
neer that marl and clay would be found. Underneath the marl and the clay, the boring 
rods had to perforate pure gravel, plastic clay, and finally chalk. No calculation from geo- 
logical data could determine the thickness of this stratum of chalk, which, from its powers 
of resistance, might present an almost insuperable obstacle. The experience acquired in 
boring the wells of Elbeuf, Eouen, and Tours, was in this respect but a very imperfect 
guide. But, supposing this obstacle to be overcome, was the engineer sure of finding a 
supply of water below this mass of chalk ? In the first place, the strata below the chalk 
possessed all the necessary conditions for producing Artesian springs, namely, successive 
layers of clay and gravel, or of pervious and impervious beds. M. Mulot, however, relied 
on his former experience of the borings of the wells at Rouen, Elbeuf, and Tours, where 
abundant supplies of water had been found below the chalk, between similar strata of clay 
and gravel, and he was not disappointed. 

The strata traversed in forming this celebrated well were as follows : — 

Drift-sand and gravel, 33 feet. 

Lower tertiary strata, - - - - - - - . 115" 

Chalk with flints, 1,148 ) . qq . ,, 

Ditto, lower, 246 f i ' dJ * 

Calcareous sandstone, clays, and sands ending in a bed of green- 
colored sand, 256 " 

1,798 " 

The surface of the ground at the well is 102 feet above the level of the sea, and the 
water is capable of being carried above this to a height of 120 feet. 

The French geologists consider that the sands from which the supply is obtained are 
either subordinate beds of the gault, or as belonging to the lower greensand. They crop 
out in a zone of country about 100 miles eastward of Paris, and range along the segment 
of a circle, of which Paris is the centre, from between Sancerre and Auxerre, passing near 
to Troyes, thence by St. Dizier to St. Menehould. The outcrop of this formation is con- 
tinued some distance further north ; it is also prolonged beyond Sancerre, southwestward 
towards Bourges, Chatellerault, and then northwest to Saumur, Le Mans, and Alencon. But 
the superficial area which it occupies in these latter districts does not appear to contribute 
to the water supply of Paris, for the axis of elevation of Mellerault must intercept the sub- 
terranean passage of the water from the district south of that line, whilst, on the north of 
Paris, the anticlinal line of the " Pays de Bray," and some smaller faults in the Aisne, pro- 
duce probably a similar stoppage with respect to the northern districts. The superficial 
area, therefore, from which the strata at the well of Grenelle draw their supplies of water, 
forms on the east of Paris a belt stretching from near Auxerre to St. Menehould. 

The exposed surface of the water-bearing beds which supply the well of Grenelle is 
about 117 square miles; the subterranean area in connection with these lines of outcrop 
may possibly be about 20,000 square miles, and the average thickness of the sands of the 
gres verts, serving in their underground range as a reservoir for the water, does not proba- 
bly exceed 30 or 40 feet. — Prestwich on the Water-bearing Strata of London. 

As the cost of these wells is an important consideration, the following statement from 
the " Water-bearing Strata of London " is of much value : — 

" M. Degoussee has recently informed me of his having contracted to bore an Artesian 
well at Rouen to the depth of 1,080 feet, (through the lower cretaceous and oolitic series,) 
for £1,600, expenses of every kind to be defrayed by him. M. Degoussee has constructed 
three Artesian wells in different parts of France, of about 820 to 830 feet each, at an ex- 
pense, including tubes and all expenses, of from £600 to £1,000. The Calais well offers 
a very near counterpart of the deposits which occur beneath London, but the difficulties of 
the first 240 feet much exceeded those which would be met with here, and the chalk is 
probably 100 to 200 feet thicker. Here and at Paris the first 1,000 feet cost less than 
£3,000, and at Doncherry apparently not much more than £2,000." 

The following Table shows the cost of several of the Artesian wells of France : — 
Vol. III.— 8 






1,79s feet 



Pas de Calais, - 

1,138 " 



Ardennes, : 

1,215 " 

St. Fargeau, 



666 " 




592 " 



Seine and Oise, 

333 " 




246 " 




155 " 



Seine and Marne, 

108 " 




65 " 

- £14,500 









It appears that, in England, the cost of boring is about 5s. for the first 10 feet, £2 10s. 
for forty feet, £5 5s. for 60 feet, £13 15s. for 100 feet, and so on in proportion. (See Sir 
Charles Lyell's " Principles of Geology," where the geological question is fully treated.) 

ARTILLERY. One of the first inquiries of importance in connection with the con- 
struction of pieces of artillery is that of the liability to fracture in the metal. Upon this 
point the researches of Mr. Mallet furnish much important matter. He tells us, as the 
result of his investigation, that it is a law of the molecular aggregation of crystalline 
solids, that when their particles consolidate under the influence of heat in motion, their 
crystals arrange and group themselves with their principal axes in lines perpendicular to 
the cooling or heating surfaces of the solid : that is, in the lines of the direction of the 
heat-wave in motion, which is the direction of least pressure within the mass. And this is 
true, whether in the case of heat passing from a previously fused solid in the act of cool- 
ing and crystallizing in consolidation, or of a solid not having a crystalline structure, but 
capable of assuming one upon its temperature being sufficiently raised, by heat applied to 
its external surfaces, and so passing into it. 

Cast-iron is one of those crystallizing bodies which, in consolidating, obeys, more or 
less perfectly according to conditions, the above law. In castings of iron the planes of 
crystallization group themselves perpendicularly to the surfaces of external contour. Mr. 
Mallet, after examining the experiments of Mr. Fah'bairn — who states (" Trans. Brit. Ass.," 
1853) that the grain of the metal and the physical qualities of the casting improve by some 
function of the number of meltings ; and he fixes on the thirteenth melting as that of 
greatest strength — shows that the size of crystals, or coarseness of grain in castings of iron, 
depends, for any given " make " of iron and given mass of casting, upon the high tempera- 
ture of the fluid iron above that just necessary to its fusion, which influences- the time that 
the molten mass takes to cool down and assume the solid state. 

The very lowest temperature at which iron remains liquid enough fully to fill every cav- 
ity of the mould without risk of defect is that at which a large casting, such as a heavy gun, 
ought to be " poured." Since the cooling of any mass depends upon the thickness of the 
casting, it is important that sudden changes of form or of dimensions in the parts of cast- 
iron guns should be avoided. In the sea and land service 13-inch mortars, where, at the 
chamber, the thickness of metal suddenly approaches twice that of the chase, is a malcon- 
struction full of evils. 

The following statements of experiments made to determine the effect produced on the 
quality of the iron in guns, by slow or rapid cooling of the casting, are from the report of 
Major W. Wade, of the South Boston Foundry, to Colonel George Bomford, of the Ord- 
nance Department of the United States. Three six-pounder cannon were cast at the same 
time from the same melting of iron. The moulds were similar, and prepared in the usual 
manner. That in which No. 1 was cast was heated before casting, and kept heated after- 
wards by a fire which surrounded it, so that the flask and mould were nearly red-hot at the 
time of casting ; and it was kept up for three days. Nos. 2 and 3 were cast and cooled in 
the usual way. 

At the end of the fourth day, the gun No. 1 and flask were withdrawn from the heating 
cylinder while all parts were yet hot. Nos. 1 and 2 were bored for 6-pounders in the usual 
way ; No. 3 for a 12-pounder howitzer, with a 6-pounder chamber. The firing of the guns 
was in every respect the same. Nos. 1 and 2 were fired the same number of times with 
similar charges. No. 1 burst at the 2*7th fire, and No. 2 at the 25th. It appears, from 
these results, that no material effect is produced on the quality of the iron by these differ- 
ent modes of cooling the castings. 

A very extensive series of experiments were made by the order of the United States 
Government, on the strength of guns cast solid or hollow. In these it was confirmed that 
the guns cast hollow endured a much more severe strain than those cast solid. Consider- 
able differences were also observed, whether the casting was cooled from within or without ; 
and Lieutenant Rodman's method of cooling from the interior is regarded as tending to 
prevent injurious strains in cooling. 

Major "Wade informs us that time and repose have a surprising effect in removing strains 
caused by the unequal coolings of iron castings. 

Great improvements have been made in improving the quality of iron guns. Guns cast 


prior to 1841 had a density of 7-148, with a tenacity of 23,63S. 
density of 7"289, with a tenacity of 37,774. 


Guns cast in 1851 had a 

The following Table gives the results of all the trials made for the United States Gov- 
ernment, showing the various qualities of different metals : — 








At Half 


Cast-iron : — 
Least - 








Wrought iron : — 

Least - 








Bronze : — 

Least - 









Cast-steel: — 
Least - 







The following analyses of the metal of iron guns of three qualities are important. 
Influence of Single Ingredients. 


Mechanical Tests. 

Chemical Constituents. 





















Influence of two or more Ingredients. 


Mechanical Tests. 

Chemical Constituents. 





and Slag. 

and Slag. 

and Slag. 

Slag, Sili- 
cium, and 














An inspection of the first of the foregoing tables, representing the average amount of 
each foreign ingredient in gun-metal deduced from all the analyses, shows a considerable 
difference in the proportions of those ingredients in each of the three classes into which 
guns are divided. It will be observed, that while the proportion of combined carbon 
diminishes from the 1st to the 3d class, that of silicium similarly increases, so that their 
united amounts are nearly the same. In other words, it appears that silicium can replace 
the carbon to a certain extent ; but that the quality of the metal is injured where the 
amount of the silicium approaches that of the carbon. Karsten made a similar observation 
in determining the limits between cast-iron and steel, but did not notice the influence of 
that substitution. 

But the differences become more striking by combining the ingredients variously to- 
gether, as in the second of those tables ; and especially by comparing the extremes, which 
are each derived from a larger number of observations than the mean. 

After showing the total amount of carbon, (both combined and uncombined,) silicium 
and combined carbon are thrown together, which indicates the replacement by silicium of 
that portion of carbon set free in the form of graphite. The column " silicium and slag " 
shows the general depreciation of the metal as the silicious metal increases. — From the 
Import of Campbell Morfit and James C. Booth to the Ordnance Office, United States 
A rmy. 



The following analyses, (rejecting those substances of which only a mere trace has been, 
discovered,) from the same chemists, are selected as showing striking peculiarities : — 


13 J3 






° 5 
E s 



S 3 








•a o 

1. 32-pdr., which endured 


the extreme proof 








- - 

•0002S -00106 

2. 32-pdr., which endured 

the extreme proof. 

Hot blast iron - 












24-pdr.,which endured 

the extreme proof. 

Hot blast iron - 











3. 42-pounder 


































Comparison of Weight, Strength, Extensibility, and Stiffness- ; Cast-iron being unity 
within practical limits to static forces only. 


Weight for 
= Volume. 





Cast-iron - 
Wrought iron - 







We find that wrought-iron guns are more than five-fold as durable as those of gun- 
metal, and twenty-two times as durable as those of cast-iron. And taking first cost and 
durability together, gun-metal cannon are about seventy-seven times, and cast-iron guns 
about thirty times, as dear as wrought-iron artillery. Again : the cost of horse-labor, or 
other means of transport for equal strength, (and, of course, therefore, for equal effective 
artillery power,) is about five times as great for gun-metal, and nearly three times as .great 
for cast-iron as for wrought-iron guns. In every respect in which we have submitted them 
to a comparison, searching and rigid, and that seems to have omitted no important point of 
inquiry, wrought iron stands pre-eminently superior to every other material for the fabrica- 
tion of ordnance. — United States Report. 

The advantages possessed by rolled bars for the construction of artillery are thus 
summed up by Mr. Mallet, in his " Memoir on Artillery " : — 

1. The iron constituting the integrant parts is all in moderate-sized, straight, prismatic 
pieces, formed of rolled bars only ; hence, with its fibre all longitudinal, perfectly uniform, 
and its extensibility the greatest possible, and in the same direction in which it is to be 
strained — it is, therefore, a better material than any forged iron can, by possibility, be 

2. The limitation of manufacture of the iron, thus, to rolling, and the dispensing with 
all massive forgings, insure absolute soundness and uniformity of properties in the 

3. The limited size of each integrant part, and the mode of preparation and combina- 
tion, aiford unavoidable tests of soundness and of perfect workmanship, step by step, for 
every portion of the whole : unknown or wilfully concealed defects are impossible. 

4. Facility of execution by ordinary tools, and under easily obtained conditions, and 
without the necessity of either for peculiarly skilled labor on the part of " heavy forge- 
men," or for steam and other hammers, &c, of unusual power, and very doubtful utility ; 
and hence very considerable reduction in cost as compared with wrought-iron artillery 
forged in mass. 

5. Facility of transport by reduction of weight, as compared with solid guns of the 
same or of any other known material. 

6. A better material than massive forged iron, rolled bars are much more scientifically 
and advantageously applied ; the same section of iron doing much more resisting work, as 
applied in the gun built-up in compressed and extended plies, than in any solid gun. 

7. The introduction thus into cannon of a principle of elasticity, or rather of elastic 
range, (as in a carriage-spring divided into a number of superimposed leaves,) greater than 
that due to the modulus of elasticity of the material itself; and so acting, by distribution 
of the maximum effort of the explosion, upon the rings successively recipient of the strain 
during the time of the ball's traject through the chase, as materially to relieve its effects 
upon the gun. 



Considerable attention has been given, of late years, to the construction of very power- 
ful pieces of ordnance. Cast-iron cannon are usually employed, but these very soon be- 
come useless when exposed to the sudden shocks of rapid firing. Cast-iron is, compara- 
tively speaking, a weak substance for resisting extension, or for withstanding the explosive 
energy of gunpowder, compared with that of wrought-iron, the proportion being as 1 is to 5 ; 
consequently, many attempts have been made to substitute wrought-iron cannon for cast, 

A gun, exhibited in 1851 by the Belgian Government, made of cast-iron "prepared 
with colce and wood" was said to have stood 2,116 rounds, and another, 3,647 rounds, with- 
out much injury to the touch hole or vent. Another is said to have been twice *' rebouched," 
and has stood 6,002 rounds without injury. As few guns of cast-iron will stand more than 
S00 rounds without becoming unserviceable, this mode of preparing the iron appears to be 
a great improvement, At St. Sebastian, 2,700 rounds were fired from the English bat- 
teries, but, as was observed by an eye-witness, '" you could put your fist into the touch- 
holes." — Colonel James, E, E. 

In Prussia they have for some time made cannon of " forged cast-steel." To get over 
the difficulty of forging the gun -with the trunnions on, the gun has been made without 
them, and a hollow casting with trunnions afterwards slipped over the breech, and secured 
in its proper position by screening in the cascable. The tenacity of this metal must be 
very great. 

Casting of Guns. — Guns have long been cast in a vertical position, and with a certain 
amount of " head of metal " above the topmost part of the gun itself. One object gained 
by this (of great value) is to afford a gathering-place for all scoria, or other foreign matter ; 
an end that might be much more effectually accomplished were the metal always run into 
the cavity of the mould by " gaits " leading to the bottom, or lowest point, in place of the 
metal being thrown in at the top, with a fall, at first, of several feet, as is now the common 
practice, by which much air and scoria are carried down and mixed with the metal, some of 
which never rises up again, or escapes as "air-bubbles." (See "Mallet on the Physical 
Conditions involved in the Construction of Artillery.'" 

Table showing the Increase of Density in Castings of large Size, due to their Solidification 
under a Head of Metal, varying from two to fourteen Feet: — 


| o 


Calder Cast-iron, No. 1. 
Hot Blast. 

Blaenavon, No. 1. 
Cold Blast. 

Apedale, No. 2. 
Hot Blast. 

Quam prox. Pressure 
when fluid in lbs. 
per square inch. 


<« a 






u« a 





C M 


"3 '£ 



































The experiments were made upon cylindrical shafts of cast-iron, cast vertically in dry 
sand-mould, under heads gradually increasing up to fourteen feet in depth, and all poured 
from " gaits " at the bottom. 

These experiments show an increase of density due to fourteen feet head, about equal 
to a pressure of ^4-8 lbs. per square inch on the casting ; from 6-9551 to 7 - 1035 for Scotch 

In the foregoing paper frequent reference has been made to the investigations of Mr. 
Mallet. His monster mortar promises such results that an especial account of it appears to 
be required. 

About the latter end of 1854, the attention of Mr. Robert Mallet, C. E., was directed to 
the mathematical consideration of the relative powers of shells in proportion to their in- 
crease of size or of diameter. His inquiries resulted in a memoir presented by him to 
Government, in which he investigated the increase of power in shells with increase of diam- 
eter, under the heads of: — 1, Their penetrative power; 2, Their increased range and 
greater accuracy of fire ; 3, Their explosive power ; 4, Their power of demolition, or of 
levelling earthworks, buildings, &c. ; 5, Their fragmentary missile power ; 6, and lastly, 
their moral effect, — in every case viewing the shell, not as a weapon against troops, but as 



an instrument of destruction to an enemy's works. The result so convinced Mr. Mallet of 
the rapid rate at which the destructive powers of a shell increase with increase of size, that 
he was induced to propose to Government the employment of shells of a magnitude never 
before imagined by any one, namely, of a yard in diameter, and weighing, when in flight, 
about a ton and a quarter each ; and to prepare designs, in several respects novel and pecu- 
liar, for the construction of mortars capable of projecting these enormous globes. Such a 
mortar was made, and on the 19th of October, 1857, the first of those colossal mortars con- 
structed from Mr. Mallet's design was fired on AVoolwich Marshes, with charges (of projec- 
tion) gradually increasing up to 70 lbs. ; and with the latter charge a shell weighing 2,550 
lbs. was thrown a horizontal range of upwards of a mile and a half to a height of probably 
three-quarters of a mile, and falling, penetrated the compact and then hard dry earth of the 
Woolwich range to a depth of more than 18 feet, throwing about cart-loads of earth and 
stones by the mere splash of the fall of the empty shell. What would have been the crater 
blown out, if the bursting charge of 400 lbs. of powder had been within ! 

It would be out of place here to attempt to follow Mr. Mallet's mathematical results as 
to the relative powers of small and large shells ; some popular notion, however, of the sub- 
ject may be given in a few words. 

Say we have a 13-inuh shell and a 36-inch shell, and, for simplicit} 7 , that each has the 
same proportion of iron and powder in relation to their bulks, or the same density. Eoughly, 
the large shell may be said to be three times the diameter of the small one. Then, a ring 
or circle through which the larger one will just pass will have nine times the area of that 
through which the smaller one will just pass, and the weight of the large shell will be 27 
times that of the small one. 

If the two shells, then, be thrown at the same angle of elevation and at the same ve- 
locity, the larger shell will range greatly further than the small one, for their relative 
resistances in the air are about as 1 to 9, while their relative energy of motion or momen- 
tum is as 1 to 27. 

A 13-inch shell, weighing about 180 lbs., is thrown, by a charge of 30 lbs. of powder, 
barely 4,700 yards. While, with not much more than double this amount of powder, the 
3G-inch shell, of more than 14 times its weight, can be thrown 2,650 yards, or much more 
than half the distance. 

The explosive power, it is obvious, is approximately proportionate to the weight of pow- 
der ; but, by calculations, of which the result only can here be given, Mr. Mallet has shown 
that the total power of demolition — that is to say, the absolute amount of damage done in 
throwing down buildings, walls, &c., &c. — by one 36-inch shell, is 1,600 times that possible 
to be done by one 13-inch shell ; and that an object which a 13-inch shell could just over- 
turn at one yard from its centre, will be overthrown by the 36-inch shell at 40 yards' 

A 13-inch shell penetrates, on falling upon compact earth, about 2i feet. The Antwerp 
shell penetrated 7 feet. The 36-inch shell penetrated 16 to 18 feet. The funnel-shaped 
cavity, or " crater," of earth blown out by the explosion of a buried shell, is always a simi- 
lar figure, called a " paraboloid ;" its diameter at the surface, produced by the 13-inch shell, 
is about 7 feet, and by the 36-inch shell about 40 feet. 

Shells. — The hollow explosive projectiles that we call shells or bombs are a very old 
invention. Under the name of " coininges," they consisted of rudely formed globes of 
plate iron soldered together, filled with gunpowder and all sorts of miscellaneous " mitraille." 
These were thrown to short distances both from " pierriers " (a sort of mortar) and from 
catapultse, as early as 1495 at Naples, 1590 at Padua, 1520 at Heilsberg, 1522 at Rhodes, 
and 1542 at Boulogne, Lieges. About the middle of the 15th century, bombs of cast-iron 
seem to have come into use ; an Englishman, named Malthus, learned the art of throwing 
them from the Dutch, and perfected the system for the French armies — being the first to 
throw shells in France, at the siege of La Mothe, in 1643. The diameter of the bomb 
seems at that time to have become fixed at 13 inches — the old Paris foot ; and at this it 
remains (with very few exceptional cases) down to the present day. 

A few attempts to increase the size and power of these projectiles have been made at 
different periods, but never with the practical skill necessary to success ; for example, 18- 
inch shells were thrown by the French, at the siege of Tournay, in 1745 ; whereas, just a 
century before, the Swedes threw shells of 462 lbs. weight, and holding 40 lbs, of powder. 
The French, when they occupied Algiers in 1830, found numbers of old shells of nearly 900 
lbs. in weight ; and in almost every arsenal and fortress in Europe one or two old 16-ineh 
and 18-inch shells are to be found. No attempt was made in modern days to realize the 
vast accession of power that such large shells confer, until the year 1832, when the " mon- 
ster mortar," as it was then called, of 24 inches' calibre, designed by Colonel Paixhans, (the 
author of the Paixhans gun,) was constructed by order of Baron Evain, the Belgian minis- 
ter of war, and attempted to be used by the French at the siege of the citadel at Antwerp, 
but with the worst possible success. The mortar, a crude cylindrical mass of cast-iron, 
sunk in a bed of timber weighing about 8 tons, and provided neither with adequate means 



for " laving 1 ' it, nor for charging it — the heavy shells weighing, when filled with 99 lbs. of 
powder," 1,015 lbs. each — could with difficulty be fired three rounds in two hours, while the 
shells themselves were very badly proportioned. 

One of these shells fell nearly close to the powder magazine, but did not explode ; had 
it fallen upon the presumed bomb-proof arch of the magazine, containing 300,000 lbs. of 
powder, it would have pierced it, according to the opinion of all the military engineers 
present at the siege ; and so closed the enterprise at a blow. The ill success of this mortar 
prevented for several years any attempt to develop bombs into their legitimate office — as 
the means of suddenly transferring mines into the body of fortified places — of a power 
adequate to act with decisive effect upon their works ; although some years afterwards a 20- 
inch mortar was made in England for the Pacha of Egypt, and proved at Woolwich. 

But another circumstance still more tended to the neglect of large shells thrown by ver- 
tical fire. After repeated trials and many failures, it was found practicable to throw 10- 
inch (and since that even 13-inch) shells from cannon, or " shell-guns," by projecting them 
nearly horizontally, or at such low angles that they should " ricochet " and roll along the 
ground before they burst ; and, thus fired, it was soon seen that their destructive power as 
against troops was greater than if fired at angles approaching 45° of elevation from mor- 
tars. Paixhans and his school had pushed a good and useful invention beyond its proper 
limits, and had lost sight wholly of the all-important fact, that horizontal shell-fire, powerful 
as it is against troops or shipping, is all but useless as an instrument of destruction to the 
works (the earthwork and masonry, &e.) of fortified places ; for this end, weight and the 
penetrative power due to the velocity of descent in falling from a great height are indis- 

No bomb-proof arch (so called) now exists in Europe capable of resisting the tremen- 
dous fall of such masses, and the terrible powers of their explosion when 480 lbs. of pow- 
der, fired to the very best advantage, put in motion the fragments of more than a ton of 
iron. No precautions are possible in a fortress ; no splinter-proof, no ordinary vaulting, 
perhaps no casemate, exists capable of resisting their fall and explosion. Such a shell 
would sink the largest ship or floating battery. 

A single 36-inch shell in flight costs £25, and a single 13-inch £2 2s., yet the former is 
the cheaper projectile ; for, according to Mr. Mallet's calculations, to transfer to the point 
of effect the same weight of bursting powder, we must give — 

55 shells of 13 inches, at £2 2s. - £115 10 

Against 1 shell of 36 inches 25 

Showing a saving in favor of the large shell of - - £90 10 

And this assumes that 55 small shells, or any number of them, could do the work of the 
single great one. 

We must briefly notice the mortars from which these projectiles are proposed to be shot, 
and of which Jig. 46 gives an elevation, with section of bore and chambers and lines of 
separation in dotted lines. 


i i n i,r M h i- i ; .i i?i-i^i ki'kii h-i u 



These mortars are, with the exception of one part, (the base,) and the elm timber ends, 
formed wholly of wrought iron, in concentric rings, and each entire mortar is separable at 
pleasure into thirteen separate pieces, the heaviest of which weighs about 11 tons, so that 
the immense weight when all put together (about 52 tons) is susceptible of easy transport, 
on ordinary artillery carriages, over rough country, or can be conveniently shipped, stowed, 
or landed. Special mortar rafts for the use of these mortars at sea have been designed by 
their inventor, and novel and more precise methods of pointing, especially at night, than 
hitherto practised. 

It has been for some time the practice in Turkey to make field-pieces like the twisted 
barrel of a rifle. One of the greatest improvements in modern artillery is the manufacture, 
by Mr. G. W. Armstrong, of Newcastle-on-Tyne, of field-pieces of this character, which arc 
breech-loading, and have several peculiarities which give them decided advantages over any 
other piece of artillery. For a further description, see Rifles. 

Exportation of arms and ammunition : — 

1852. 1853. 1854. 

Guns - - - No. 181,121 238,767 226,952 

Gunpowder - - lbs. 7,140,133 9,410,891 8,715,213 



Foreign and Colonial. 

Gun stocks in the rough of wood cwts. 235 

ASBESTUS, from fofiearos, ^inconsumable. (Asbeste, Fr. ; Asbest, Germ.) When the 
fibres of the fibrous varieties of amphibole are so slender as to be flexible, it is called asbes- 
tus, or amianthus. It is found in Piedmont, Savoy, Salzburg, the Tyrol, Dauphme, Hun- 
gary, Silesia ; also in Corsica so abundantly as to have been made use of by Dolomieu for 
packing minerals ; in the United States, St. Kevern in Cornwall, in Aberdeenshire, in some 
of the islands north of- Scotland, and Greenland. Asbestus was manufactured into cloth by 
the ancients, who were well acquainted with its incombustibility. This cloth was used for 
napkins, which could be cleansed by throwing them into the fire ; it was also used as the 
wick for lamps in the ancient temples ; and it is now used for the same purpose by the na- 
tives of Greenland. It has been proposed to make paper of this fibrous substance, for the 
preservation of important matters. An Italian, Chevalier Aldini, constructed pieces of 
dress which are incombustible. Those for the body, arms, and legs, were formed out of 
strong cloth steeped in a solution of alum ; while those for the head, hands, and feet, were 
made of cloth of asbestos. A piece of ancient asbestus cloth, preserved in the Vatican, 
appears to have been formed by mixing asbestus with other fibrous substances ; but M. 
Aldini has executed a piece of nearly the same size, which is superior to it, as it contains 
no foreign substance. The fibres were prevented from breaking by the action of steam. 
The cloth is made loose in its fabric, and the threads are about the fiftieth of an inch in 
diameter. The Society of Encouragement, of Paris, has proposed a prize for the improve- 
ment of asbestus cloth. The use of it is now (1858) being exhibited in London. 

ASHES. In commerce, the word ashes is applied to the ashes of vegetable substances 
from which the alkalies are obtained, as Kelp, Barilla, &c, (which see.) 

It is the popular name of the vegetable alkali, potash, in an impure state,- as procured 
from the ashes of plants by lixiviation and evaporation. The plants which yield the great- 
est quantity of potash are wormwood and furmitory. See Potash, Peaelash, and for the 
mode of determining the value of ashes, Alkalimetry. 

Our Importations of the various kinds of Ashes were — 
1855. 1856. 

Soap ashes, cwts. 258 

Wood ashes, " 26 - cwts. 1,073 (vcdasse, Fr. ; waidasche, Germ.) 

Weed ashes, " - - " 380 

Unenumerated ditto, value £5,302 £7,131 ; 

and of pearl and pot ashes as follows : — 

Countries from which imported. 





Russia ------ 



British North America - 

United States ... - 

Prize cargoes - 

Other parts 




















ASHES OF PLANTS. The ashes of all species of woods and weeds are found to con- 
tain some alkali, hence it is that the residuary matter, after the combustion of any vege- 
table matter, is found to act as a stimulant to vegetable growth. 

The following analyses of the ashes of plants have been selected from the tables which 
have been published, by Messrs. Thomas Way and G. Ogston, in the " Journal of the Agri- 
cultural Society " : — 





Wheat 1 
., . ; Straw. 
Oram. | 





















Soda - 




. . 






















Magnesia - 












3 78 














SulDhuric acid - 



















73 57 







Carbonic acid - 






- - 

- - 

- - 





Phosphorie acid 













Chloride of potas- 



Chluride of sodium 

- - 




- - 

- - 

- - 

- - 





Total amount - 













Percentage of ash 

in the dry sub- 

stance - 






- - 







Percentage of ash 

in the fresh sub- 

stance - 






- - 







ASPHALTIC MASTIC, used in Paris for large works, is brought down the Rhone from 
Pyrimont, near Lyssell. It is composed of nearly pure carbonate of lime, and about 9 or 
10 per cent, of bitumen. 

When in a state of powder it is mixed with about 7 per cent, of bitumen or mineral 
pitch, found near the same spot. The powdered asphalt is mixed with the bitumen in a 
melted state along with clean gravel, and consistency is given to pour it into moulds. Sul- 
phur added to about 1 per cent, makes it very brittle. The asphalt is ductile, and has elas- 
ticity to enable it, with the small stones sifted upon it, to resist ordinary wear. Walls 
having cracked, and parts having fallen, the asphalte has been seen to stretch and not crack. 
It has been regarded as a sort of mineral leather. The sun and rain do not appear to affect 
it ; and it answers for abattoirs and barracks, keeps vermin down, and is uninjured by the 
kicking of horses. 

A large roof has been formed in Paris for a store for the Government food, entirely of 
earthenware tiles, and without timber, the tiles being 9 inches long and 5 wide. The arch 
is covered with a concrete of lime, sand, and gravel ; then with a thin coat of hydraulic 
mortar ; over this, when dry, canvas was tightly stretched ; asphaltic mastic was poured in 
a semi-fluid state, and this formed the finished surface of the roof. The strength of the 
roof has been purposely tested to bear six tons without yielding, and has borne the acci- 
dental fall of a stack of chimneys, with the only effect of bruising the mastic, readily 

ASPHALTUM. (Bitume or Asphalte, Fr. ; Asphalt, Germ.) Mineral Pitch ; so 
called from the lake Asphaltites ; a variety of bitumen, arising from one of the many pecu- 
liar changes of vegetable matter. Asphaltum, in common with other varieties of bitumen, 
is a form of hydrocarbon produced in the interior of the earth by the transformation of 
carbonaceous matter, like all combustible bodies of the same class. Composition, C 6 H 5 . 
It is a solid black or brownish-black substance, possessing a bright conchoidal fracture. It 
fuses at 212° F., burning with a brilliant flame, and emitting a bituminous odor. Specific 
gravity = 1 to 1 -2. Asphaltum is insoluble in alcohol, but soluble in about five times its 
weight of naphtha. See Bitdmen. 

This solid shining bitumen, of a deep black color when broken, is found in many parts 
of Egypt. A thin piece appears of a reddish color when held to the light ; when cold, it 
has no odor ; by a moderate heat or by friction, the odor is slight ; fully heated, it lique- 
fies, swells, and burns with a thick smoke ; the odor given is acrid, strong, and dis- 

Spirits of wine dissolves pitch, but only takes a pale color with asphaltum. It is readily 
procured at Mocha. 

In the arts, asphaltum is used as a component of japan varnish. It is likewise em- 
ployed as a cement for lining cisterns, and for pavements, as a substitute for flag-stones. — 
H. W. B. 

The following quantities of Asphaltum, or Bitumen Judaicum, were imported into 
Great Britain : — in 1855, 1,674 tons ; in 1856, 2,707 tons, of which 2,573 tons were from 


ASSAY and ASSAYING. The process employed in assaying gold bullion, by the pres- 
ent assayers to the Mint and Bank of England, is similar to that practised at the Paris Mint. 
The quantity operated on is half a gramme. This quantity, having been accurately weighed, 
is wrapped in paper with a portion of pure silver, about equal to three times that of the 
gold the alloy is supposed to contain, and submitted to cupellation with lead in the manner 
described in vol. i. The button is then hammered into a flattened dish, about the size of a 
sixpence, and afterwards annealed and passed through laminating rolls until it is reduced to 
a riband from 2i to 3 inches in length ; after which it is again annealed, and coiled into a 
spiral by rolling between the finger and thumb. The cornet is next placed in a small flask 
containing about an ounce of pure nitric acid of 22 B., ( = 1-180 specific gravity,) and 
boiled for 10 minutes. The acid is carefully poured off, and the cornet again boiled with 
nitric acid of 32 B. (1-280 specific gravity) for 20 minutes ; and this second boiling with 
the stronger acid is repeated and continued about 10 minutes. In the second and third 
boilings a small piece of charcoal should be introduced into the flask, as recommended by 
Gay-Lussac, in order to prevent the ebullition taking place irregularly and with sudden 
bursts, which would be liable to break the cornet, and eject a portion of the liquid from the 
flask. The cornet is then washed and annealed as above. The return is made to the Mint 
in decimals or thousandths, and the assayer's weights are so subdivided as to give him the 
value in thousandths of the original -J gramme taken. 

To the Bank the return is made to the -J- of a carat grain better or worse than standard. 
The late Master of the Mint caused Tables to be prepared for the conversion of the reports 
of assays expressed in carats into decimals, and conversely, which are in general use for 
this purpose. In order to ascertain the amount of error due to the surcharge, a number of 
proofs are passed through the process simultaneously with the alloys. These proofs con- 
sist of weighed portions of absolutely pure gold, to which is added a proportion of cop- 
per equal to that estimated to exist in the alloy to be assayed. The excess of weight in 
these proofs gives the amount to be deducted. It generally varies from 0-2 to 0-5 parts 
in 1,000. 

The last traces of silver may be removed from the cornet by treating it before the final 
annealing with fusing bisulphate of potash in a porcelain crucible. When sufficiently cool, 
the whole is heated with hot water containing a little sulphuric acid, and the cornet dried 
and ignited, 
it is termed. 

The following examples will show the difference in the results, and the degree of accu- 
racy attainable, by the various methods described : — 

Ten grains of pure gold, alloyed with three times its weight of silver, cupelled and 
boiled with acid at 22° B., and 32° B., once weighed 10-016. 

Ten grains of a half-sovereign, with silver, &c, and acid at 22°, and twice at 32° B., 

gave 915'4 

again, 915-6 

"With acid, as before, and bisulphate of potash, 915-2 

again, 915-2 

Pure gold alloyed with copper, to bring it to standard, cupelled with silver and lead, 
and treated with acids and bisulphate, gave in one case precisely the same as was taken 
originally, or luo %ooo, and in another 999-98. 

In accurate assaying of gold bullion, it is of course absolutely necessary that 47 
the acids should be pure, and that the silver used should be most carefully freed \^ = ^' 
from the traces of gold which it usually contains. 

Instead of charcoal or coke, which are generally used for cupellation, much 
advantage has been found in employing the best anthracite : reduced to the prop- 
er size, it contains very little ash, is free from slag or clinker, and allows the heat 
to be maintained at one steady temperature for many hours, which is a matter of 
great importance to the assayer.* 

ASTRAGAL. An ornamental moulding, generally used to conceal a junction 
in either wood or stone. 

ASTRAGAL PLANES. Planes fitted with cutters for forming astragal mould- 
ings. They are commonly known as moulding planes. 

ASTRAGAL TOOL, for turning. By using a tool shaped as in Jig. 47, the 
process of forming a moulding or ring is greatly facilitated, as one member of 
the moulding is completed at one sweep, and we are enabled to repeat it any 
number of times with exact uniformity. 

* The most useful works on this subject are :— Chaudet, "L'Art de TEssayeur ; " the work of Gay- 
Lussac mentioned in the text; "Manuel complet de l'Essayeur," par Tauquelin and D'Areet, edited by 
Vei-gnaud, Paris, 1S36, (a most useful little work;) Bodemann, "Anleitung zur Berg- und Huttenman- 
nischen Probierkunst," Clausthal. 1845; and (perhaps the best of them airfthe "Scheikundig Handboek 
voor Essaijeurs Goud und Zilversmeden " by Stratingh, Groningen, 1821. 


ATOMIC THEORY. Dr. Dalton suggested the happy idea, which has been most fruit- 
ful in its results, of accounting for the constancy of chemical combinations by assuming that 
they were composed of one or more atoms of the several elements, the weight of which 
atoms is represented by the combining proportions ; that carbonic oxide, for instance, con- 
tains single atoms of carbon and oxygen, whilst carbonic acid is composed of one atom of 
carbon and two of oxygen. 

It must always be" remembered that the combining proportions are purely the results 
of experiment, "and, therefore, incontestable, whatever may be the fate of this theory, 
which, however, has now stood its ground for many years, and done excellent service to 

This theory offers a most satisfactory explanation of the different laws of chemical com- 

The fact of bodies uniting only in certain proportions, or multiples of those proportions, 
is a necessary consequence of the assumption that the weight of the elementary atoms is 
represented by the combining proportions ; for, if they united in any other ratio, it would 
involve the splitting up of these atoms, which are assumed to be indivisible. 

And, of course, the combining proportion of a compound must be the sum of the com- 
bining proportions of the constituents, since it contains within itself one or more atoms of 
the several constituents. 

The term atom is, therefore, very often used instead of combining proportion or equiva- 
lent, a body being said to contain so many atoms of its elements. 

All that is assumed in this theory is, that the atoms are of constant value by weight ; 
the same atoms may be arranged in a different way, and hence, although any particular 
compound contains always the same elements in the atomic ratios, yet the same atoms may, 
by difference in arrangement, give rise to bodies agreeing in composition by weight, but 
differing essentially in properties. 

M. Dumas has suggested the subdivision of the combining numbers of certain elements, 
but this idea is quite subversive of the atomic theory, as it is at present understood. 

The atomic theory is further confirmed by the observation, that if the specific heat of 
the elements be compared, it is found that in a large number of cases the specific heat of 
quantities of the bodies represented by the atomic weights coincides with each other in a 
remarkable manner. 

The Atomic Theory of Dalton is thus set forth by the author : — 

" When any body exists in the elastic state, its ultimate particles are separated from 
each other to a much greater distance than in any other state ; each particle occupies the 
centre of a comparatively large sphere, and supports its dignity by keeping all the rest — 
which, by their gravity, or otherwise, are disposed to encroach on it — at a respectful dis- 
tance. When we attempt to conceive the number of particles in an atmosphere, it is some- 
what like attempting to conceive the number of stars in the universe — we are confounded 
with the thought. But if we limit the subject, by taking a given volume of any gas, we 
seem persuaded that, be the divisions ever so minute, the number of particles must be 
finite ; just as in a given space of the universe, the number of stars and planets cannot be 

" Chemical analysis and synthesis go no further than to the separation of particles one 
from another, and to their reunion. No new creation or destruction of matter is within the 
reach of chemical agency. We might as well attempt to introduce a new planet into 
the solar system, or to annihilate one already in existence, as to create or destroy a par- 
ticle of hydrogen. All the changes we can produce consist in separating particles that 
are in a state of cohesion or combination, and joining those that were previously at a dis- 

" In all chemical investigations it has justly been considered an important object to 
ascertain the relative weights of the simples which constitute a compound. But, unfortu- 
nately, the inquiry has terminated there ; whereas, from the relative weights in the mass, 
the relative weights of the ultimate particles or atoms of the bodies might have been 
inferred, from which their number and weights in various other compounds would appear, 
in order to assist and to guide future investigations, and to correct their results. Now it is 
one great object of this work (' A New System of Chemical Philosophy') to show the im- 
portance and advantage of ascertaining the relative weights of the ultimate particles, both 
of simple and compound bodies, the number of simple elementary particles ichich constitute 
one compound particle, and the number of less compound particles which enter into the 
formation of each more compound particle." 

For a full examination of this subject, consult " An Introduction to the Atomic Theory," 
by Charles Daubeny, M.D. ; and "Memoirs of John Dalton and History of the Atomic 
Theory," by Robert Angus Smith, Ph. D. 

The following Table will show the quantity of precipitate that may be expected to result 
from the addition of nitrate of silver to 100 grains of a salt of sodium, according to the 
proportion of chloride and of bromide present : — 



Quantity of Salt. 

Quantity of 

Quantity of Salt. 

Quantity of 

Amount of Precipi- 
tate from the two 

Br. Sodium. 

Br. Silver. 

Ch. Sodium. 

Cb. Silver. 





















































WEIGHT, or PROPORTION. The following propositions may be regarded as the laws 
regulating atomic combination : — 

1. The equivalents of elementary bodies represent the smallest proportions in which they 
enter into combination with each other. 

2. Tlie equivalent of a compound body is the sum of the equivalents of its elements. 

3. Combination takes place, whether between elements or compounds, cither in the pro- 
portions of their equivalents, or in multiples of these proportions, and never in sub- 

4. The law of definite and multiple proportion is, individual compounds always contain 
exactly the same proportions of their elements. See Equivalents, Chemical. 

ATOMIC VOLUMES. Recently it has been assumed that the elements unite invariably 
in equal volumes — when in the gaseous state ; — or, in other words, that the atoms of bodies 
have always the same volume. If this doctrine be maintained, it becomes necessary to alter 
the atomic weights or combining numbers of certain elements. For example, water con- 
tains two volumes of hydrogen to one of oxygen ; but, according to the generally received 
idea, it consists of single atoms of each element ; it is clear, therefore, that if we are to 
assume that the atoms of hydrogen and oxygen have the same volume, we must either 
halve the atomic weight of hydrogen or double that of oxygen. 

Berzelius suggested that all the atomic weights should remain the same, except those 
of hydrogen, nitrogen, phosphorus, chlorine, bromine, and iodine, which should halve their 
present value. Gerhardt, on the other hand, adopts the more convenient practice of allow- 
ing hydrogen and its congeners to retain their present atomic weights, doubling those of 
oxygen, sulphur, tellurium, and carbon. 

ATROPINE. (C 31 H 23 NO fi .) An exceedingly poisonous alkaloid, found in deadly night- 
shade (Atropa Belladona) and in stramonium (Datura Stramonium.) 

ATTAR OF ROSES, more commonly, OTTO OF ROSES. An essential oil, obtained 
in India, Turkey, and Persia, from some of the finest varieties of roses. It is procured by 
distilling rose leaves with water, at as low a temperature as possible. It is said that this 
perfume is prepared also by exposing the rose leaves in water to the sun ; but, from the 
fact that under the circumstances fermentation would be speedily established, it is not 
probable that this is a method often resorted to. By dry distillation from salt-water 
baths, no doubt the finest attar is obtained. This essential oil is only used as a perfume. 
Attar of roses is adulterated with spermaceti and with castor oil dissolved in strong alco- 

This adulteration may be detected by putting a small drop of the otto of roses on a 
piece of clean writing paper ; by agitation in the air, the volatile oil soon evaporates, leav- 
ing no stain if pure ; if any fixed oil is present, a greasy spot is left on the paper. 

ATTENUATION. Brewers and distillers employ this term to signify the weakening of 
saccharine worts during fermentation, by the conversion of the sugar into alcohol and car- 
bonic acid. 

AURUM MUSIVUM or MOSAICUM. Mosaic Gold.— For the preparation of Mosaic 
gold, the following process is recommended by Woulfe. An amalgam of 2 parts of tin and 
1 part of mercury is prepared in a hot crucible, and triturated with 1 part of sal-ammoniac, 
and 1 part of flower of sulphur ; the mixture is sublimed in a glass flask upon the 
sand bath. In breaking the flask after the operation, the sublimate is found to consist, 
superficially, of sal-ammoniac, then of a layer of cinnabar, and then of a layer of Mosaic 

There are several other processes given for the preparation of this bisulphide of tin, but 
the above probably gives the best results. 



Bergman mentions a native aurum musivum from Siberia, containing tin, sulphur, and 
a small proportion of copper. Dr. John Davy gave the composition as — 

Tin 100 | Sulphur - 56-25 

Berzelius as — 

Tin 100 | Sulphur - 52-3 

Mosaic gold is employed as a bronzing powder for plaster figures, and it is said to enter 
sometimes into the composition of aventurine. 

AUTOGENOUS SOLDERING. A process of soldering by which metals are united 
either by the ordinary solders or by lead, 
under the influence of a flame of hydro- 
gen or of a mixture of hydrogen and 
common air. 

The process of using air and hydro- 
gen was invented in France, by the Count 
de Eichemont. Hydrogen gas is con- 
tained in a gasometer, to which a flexible 
tube is connected, and air is urged from 
a bellows worked by the foot, through 
another tube, and on to the blowpipe, 
where the hydrogen is ignited. By means 
of the flexible tubes the flame can be 
moved up and down the line of any joint, 
and the connecting medium melted. Fig. 

This process has been a good deal employed for plumbers' work, especially in our naval 

AUTOMATIC ARTS. Such arts or manufactures as are carried on by self-acting ma- 

AVENTURINE. (Aventurine, Fr.) A variety of quartz which is minutely spangled 
throughout with yellow scales of mica ; is known as Aventurine quartz. It is usually 
translucent, and of a gray, brown, or reddish-brown color. There is also an Aventurine 
felspar [Feldspath aventurine, Fr.) Commercially, in France and some other parts of 
Europe, the name of Pierre de soleil is given to the finest varieties of the felspar aventu- 
rine, some lapidaries, however, calling this stone by the name of Aventurine orientate. 
This aventurine occurs at Capa de Gata, in Spain ; it has reddish and yellow internal 

An artificial aventurine has been manufactured on a large scale for a long period, at the 
glass-works of Murano, near Venice. According to Wohler's examination, aventurine glass 
owes its golden iridescence to a crystalline separation of metallic copper from the mass 
colored brown by the peroxide of iron. 

C. Karsten analyzed the artificial aventurine from the glass manufactory of Bigaglia, in 
Venice, and found it to contain — 

Silicic acid 67-3 

Lime 9-0 

Protoxide of iron 3 - 4 

Binoxide of tin - - - - 2-3 

Protoxide of lead l - 

Metallic copper --------- 4 - 

Potash 5-3 

Soda 7-0 

These numbers agree in a remarkable manner with the results formerly obtained by Peligot, 
and may therefore be regarded as truly representing the composition of the glass. 

AVERRUNCATOR. A pair of pruning shears, which, on being mounted on a pole 
some ten feet long, and actuated by a string of catgut, can be used for pruning at a consid- 
erable distance above the head. 

AVOCADO PEAR OIL. An oil obtained from the oleaginous fruit the Avocado pear- 
tree, (Laurus Persea,) a native of Trinidad. A portion of this oil having been submitted 
to Dr. Hofmann by the Governor of Trinidad, he reported on its character and composition. 
The following is an extract from his report : — 

" According to my present experience, the oil of the Avocado pear is less valuable as a 
lubricating material. To make it fit for the higher classes of machinery, its mucilaginous 
constituents must be removed by the same refining process requisite for its adaptation in 
illuminating purposes. This will slightly increase its price. Even when purified it retains 
an attraction for oxygen, by which it becomes rapidly colored, viscid, and actually acid. It 
cannot, either in price or in applicability, compete with that remarkable substance ' Paraf- 



fine oil,' which has been discovered within the last year by Mr. James Young, and which is 
now manufactured by him on a large scale, by the distillation, at a low temperature, of sev- 
eral varieties of coal. 

" On the other hand, the oil of the Avocado pear is very applicable for the production 
of good soap. I have the honor of transmitting to your Excellency specimens prepared 
with the oil : the smaller one, which possesses a yellow color, is prepared with the oil in its 
original condition ; the larger one is made with a portion of oil which had previously been 
bleached by chlorine. From this specimen it is obvious that the oil, although poor in 
stearine; nevertheless furnishes a soap which is tolerably hard and solid. It ought to be 
remembered that it is difficult to obtain a hard soap by working on the small scale pre- 
scribed by the limited amount of material at my disposal. For the perfect elaboration of 
this investigation also, a large supply of material will be of great advantage ; but I have 
even now no hesitation in stating, that, for the purposes of the soap-maker, the oil of the 
Avocado pear will have, at least, the same value as palm oil." 

AZIMUTH COMPASS. The azimuth compass is used chiefly to note the actual mag- 
netic azimuth, or that arch of the horizon intercepted between the azimuth, or vertical 
circle passing through the centre of any heavenly body, and the magnetic meridian. 

The card of the azimuth compass is subdivided into exact degrees, minutes, and seconds. 
To the box is fixed two " sights," through which the sun or a star may be viewed. The 
position into which the index of the sights must be turned to see it, will indicate on the 
card the azimuth of the star. When the observations are intended to be exact, telescopes 
take the place of the sights. By this instrument we note the actual magnetic azimuth ; 
and, as we know the azimuth calculated from the N. and S. line, the variation of the needle 
is readily found. 

AYR STONE, called also Scotch stone and snake stone, is much in request as a polish- 
ing stone for marble and for copper plates. These stones are always kept damp, or even 
wet, to prevent their becoming hard. 

The harder varieties of Ayr stone are now employed as whetstones. 

AZURITE. This term has been applied to several blue minerals, which have little in 
common. Beudant and Dana use it to signify the blue carbonate of copper — now termed 
Chessylite by Brook and Miller, from its occurring in fine crystalline forms at Chessy, near 
Lyons ; hence commonly called Chessy copper. 

Azurite is also applied to the Lazulite of Dana ; which is again called Azure stone and 
blue spar by others. 

The same term is also given to the Lapis lazuli, from which ultramarine is obtained. 

This want of agreement between mineralogists — leading them to adopt names inde- 
pendent one of the other (names frequently taken from some locality in which the writer 
knows the mineral to be found) — produces great confusion, and retards the progress of 


BACK. A mining term. The back of a mineral lode is that part which is nearest the 
surface. The back of a level is the ground between it and the level above it. 

BACK. A brewer's utensil. 

BAIN-MARIE. A vessel of water in which saucepans, &c, are placed to warm food. 

BAIZE. A coarse woollen stuff with a long nap, sometimes frized on one side. 

BAKERS' SALT. The sesquicarbonate of ammonia, so called because it is often used 
as a substitute for yeast in bread and pastry. 

BAL. An ancient Cornish miner's term for a mine. Bal-maidens is a name given to 
girls working at a mine. 

BALACHONG. An article of food much used in the Eastern Archipelago, consisting 
of fish and shrimps pounded together. 

BALANCE FOR WEIGHING COIN introduced at the Bank of England in the year 

Mr. William Cotton, then Deputy-Governor, and during the two succeeding years Gov- 
ernor of the Bank, had long regarded the mode of weighing by common hand-balances with 
dissatisfaction on account of its injurious effect upon the " teller," or weigher, owing to the 
straining of the optic nerve by constant watching of the beam indicator, and the necessity 
of reducing the functions of the mind to the narrow office of influencing a few constantly 
repeated actions. Such monotonous labor could not be endured for hours together without 
moments of forgetfulness resulting in errors. Errors more constant, although less in 
amount, were found to be due to the rapid wearing of the knife-edges of the beam ; cur- 
rents of air also acting upon the pans produced undesired results ; and even the breath of 
the "teller" sometimes turned the scale ; so that, in hand-weighing, the errors not unfre- 
quently amounted to J-, and even ■£ grain. A.t the very best, the hand-scale working at the 
rate of 3,000 per six hours could not indicate nearer than V 25 grain. 


Upon taking into consideration the inconveniences and defects of the hand-weighing 
srstem Mr. Cotton conceived the idea that it might be superseded by a machine defended 
from external influences, and contrived so as to weigh coins as fast as by hand, and within 
the fourth of a grain. He subsequently communicated his plan to Mr. David Napier, of 
York Koad, Lambeth, engineer, who undertook the construction of an experimental ma- 
chine. Its capabilities were tested and reported upon by Mr. William Miller, of the Bank. 
The result was most satisfactory ; more " automaton balances " were ordered ; and from 
time to time further additions have been made, so that at present there are ten in daily 
operation at the Bank of England. But it was not without a struggle that the time-hallowed 
institution of tellers passed away. There were interests opposed to the introduction of 
improved, more ready, and less expensive methods ; and it required all Mr. Cotton's energy 
of character, the influence of his intelligence in mechanics, as well as that arising from his 
position in the Direction, to obtain the adoption of an invention by which a very large 
annual saving has been effected. 

The mechanical adaptation of the principles involved in the Automaton Balance, as con- 
trived by Mr. Napier, may be shortly explained : — The weighing beam, of steel, is forked 
at the ends, each extremity forming a knife-edge ; and in the centre the fulcrum knife-edge 
extends on each side of the plate of the beam, and rests in hollows cut in a bowed cross- 
bar fixed to the under side of a rectangular brass plate, about 12 inches square, which is 
supported at the corners by columns fixed to a cast-iron table raised a convenient height on 
a stand of the same metal. To form a complete enclosing case, plates of metal or glass are 
slid into grooves down the columns. When the beam is resting with its centre knife-edge 
in the hollows of the cross-bar just referred to, its upper part is nearly on a level with the 
under side of the brass plate, in which a long slot is made so that the beam can be taken 
out when the feeding slide-box, and its plate, which covers this slot, are removed. On the 
top of the covering plate of the feeding slide a tube hopper is placed, and a hole in the 
plate communicates with the slide ; another hole is pierced in the same plate exactly over 
one end of the beam, upon the knife-edges of which a long rod is suspended by hollows 
formed in a cross-bar close to its upper end, where the weighing platform is fitted. A rod 
is also suspended at the other end of the beam in a similar manner ; but instead of a weigh- 
ing plate, it has a knob at top, which, when the beam is horizontal, comes into contact with 
an adjustable agate point. The lower end of this pendant rod is stirrup-shaped, for holding 
the counterpoise. Two displacing slides are provided, one on each side of the feeding slide, 
and at right angles to each other ; and a gripping apparatus is fixed to the under side of the 
brass top plate, arranged so as to hold the pendant on which the scale-plate is fitted during 
the change of the coin. A dipping-fiuger is also attached to the frame of the gripping 
apparatus, its end passing into a small slot in the pendant rod, and acting upon a knife-edge 
at the lower end of the slot. There are four shafts crossing the machine ; the one through 
which the power is applied is placed low and at the centre, and carries a pinion which gears 
with a wheel of twice its diameter on a shaft above ; this wheel gears with two similar 
wheels fixed to shafts on each side of the centre. Cams for acting upon the feeding slide 
through the medium of a rocking frame, are carried by the shaft placed at the end of the 
machine where the counterpoise hangs, and the other two shafts on the same level bear 
cams for working the gripping apparatus, the dipping-finger, and the displacing slides. 

Having described, as clearly and as popularly as we can, the general features of the 
mechanism, we will proceed to indicate its manner of action. Suppose, then, the hopper 
filled, and a hollow inclined plane about two feet long, which has been added to the hopper 
by the inventive genius of one of the gentlemen in the weighing-room, also loaded its 
whole length with the pieces to be weighed, the machine is set in motion, and the feeding 
slide pushes the lowest piece forward on to the weighing plate, the grippers meantime hold- 
ing fast by the neck of the pendant, so as to keep the plate perfectly steady ; the dipping- 
finger is also at its lowest position, and resting upon the knife-edge at the bottom of the 
slot in the pendant rod, thus keeping the beam horizontal, and the knob on the counter- 
poise pendant, in contact with the agate point already mentioned. When the coin is fairly 
placed on the weighing-plate, the grippers let go their hold of the pendant rod, and the 
dipping-finger is raised by its cam ; if then the coin is too light, the coin end of the beam 
will rise along with the dipping-finger, and the counterpoise end will descend ; if heavy, 
the beam will remain without motion, the agate point preventing it. As soon as the dip- 
ping-finger attains the proper height, and thus has allowed sufficient time for the weight of 
the coin to be decided, the grippers close and hold the pendant, and consequently the scale 
or weighing-plate, at the high level, if the coin has proved light, and been raised by the 
excess of weight in the counterpoise ; and at the low or original level, if the coin has 
proved heavy. One of the displacing slides now comes forward and passes under the coin, 
if it is light, and therefore raised to the high level ; but knocks it off, if remaining on the 
low level, into the " heavy " box. The other displacing slide then advances. This strikes 
higher than the first, and removes the light piece which the other has missed, into the 
receptacle for the light coin. During these operations the feeding-slide has brought forward 

128 BALE. 

another coin, and the process just described is repeated. The attendant is only required to 
replenish the inclined plane at intervals, and remove the assorted coin from the boxes. The 
perfection of the workmanship, and the harmony of the various actions of the machine, 
will be best appreciated from the fact, that 25 pieces are weighed per minute to the fineness 
of Vioo of a grain. This combination of great speed and accuracy would not have been 
possible with a beam made in the ordinary way, having the centre of gravity below the 
centre of action ; and it was pronounced to be so by the late Mr. Clement, the constructor 
of Mr. Babbage's Calculating Machine. But Mr. Napier overcame the difficulty by raising 
the centre of gravity so as to coincide with the centre of action, which gave it much greater 
sensibility ; and he provided the dipping-finger, to bring the beam to a horizontal position 
after each weighing, instead of an influencing weight in the beam itself. 

The wear and tear of these machines are found to be very small indeed ; those supplied 
in 1842 and 1843, and in daily use ever since, weigh with the same accuracy as at first, 
although they may be said to have cost nothing for repairs. The principal cause of this 
long-continued perfection is that the beam does not oscillate, unless the coin is light, and 
even then the space passed through does not exceed the thickness of the coin. 

In 1851, when the Moneyers were no longer wasters of the Royal Mint, and the new 
authorities began to regard the process of weighing the coin in detail by hand as a laborious, 
expensive, and inaccurate method, the firm of Napier & Son, at an interview with Sir John 
Herschel, the Master, and Captain Harness, the Deputy-Master, received an order for five 
machines, to be designed to suit the requirements of the Mint, which involved a complete 
chauge in the mechanical arrangement of the machine as used at the Bank, it being neces- 
sary to divide the " blanks," or pieces before they are struck, into three classes : " too 
light," " too heavy," and " medium," or those varying between certain given limits. It 
would occupy too much space to attempt a description of the mechanical disposition of this 
machine, and it could not be satisfactorily accomplished without the aid of drawings ; let it 
suffice, then, to say that the displacing-slides are removed, and a long vibrating conducting- 
tube receives the blanks as they are in turn pushed off the weighing-plate by the on-coming 
blanks ; but, according to the weight of the blank, so the lower end of the tube is found to 
be opposite to one of three openings leading into three boxes. The tube is sustained in its 
proper position, during the descent of the blank last weighed through it, by a stop-finger, 
the height of which is regulated by a dipping-finger, which comes down upon a knife-edge 
at the lower end of a slot in the pendant-rod just when the grippers have laid hold of the 
rod after the weighing is finished ; this finger thus ascertains the level which the knife-edge 
has attained, and as it brings down the stop-finger with it, the guide-tube, which is furnished 
with three rests, as steps in a stair, vibrates against the stop-finger, one of the three steps 
coming in contact with it, according to the level of the stop-finger ; and the end of the 
guide-tube takes its place opposite the channel leading to the box in which the blank should 
be found. The counterpoise employed is less than the true standard weight, by the quan- 
tity which may be allowed as the limit in that direction ; and in case a blank is too heavy, 
not only is the counterpoise raised, but a small weight, equal to the range allowed between 
the " too light " and " too heavy," is raised also ; this small weight comes to rest on sup- 
ports provided for it when the beam is horizontal, and is only disturbed by a too heavy 

These machines have proved even more accurate and rapid than those made for the 
Bank ; and Professor Graham, the present master, amongst the improvements introduced 
by him into the system of the Mint, has added to the number, and dispensed entirely with 
the hand-weighing. It is said that the saving accruing from this change alone amounts to 
nearly £2,000 per annum. 

BALE. A package of silk, linen, or woollen, is so called. 

BALLISTIC PENDULUM. An instrument for measuring the force of cannon-balls. 
The ballista was an instrument used by the ancients to throw darts, &c. The ballistic pen- 
dulum derives its name from this : it consists of an iron cylinder, closed at one end, sus- 
pended as a pendulum. A ball being fired into the open end, deflects the pendulum accord- 
ing to the force of the blow received from the ball, thus measuring its power. 

BALLOON. In France, a quantity of glass. Of white glass, 25 bundles of six plates 
each ; of colored glass, 12^ bundles of three plates each are called balloons. 

BALLOON, AIR. A varnished silk or other bag filled with gas, or warm air, which, 
being specifically lighter than the atmosphere, ascends in it. Numerous attempts have been 
made to bring air balloons under the control of the aeronaut, so as to guide them across the 
currents of the atmosphere ; but all of these have proved unsuccessful, the balloon and its 
voyagers having always moved with the aerial current, in spite of the mechanical appliances 
which have been adopted. 

BAMBOO. {Bambon, Fr. ; Indianischer Bohr, Germ.) A species of cane, the Bain- 
bos arundinacea of botanists. A most important vegetable product in the East, where it is 
used in the construction of houses, boats, bridges, &c. Its grain is used for bread ; its 
fibre is manufactured into paper. 



Walkm"- sticks are frequently said to be of bamboo ; they are the ratan, a different 

BANDOLINE, called also cli/sphitique and fixature, a mucilage of Carrageen moss; 
used for stiffening the hair and keeping it in order. 

BARBAKY GUM. Sometimes called Morocco gum. The product of the Acacia 
gummifera. Imported from Tripoli, Barbary, and Morocco. 

BARBERRY. (Berberris, Lat. ; Epine-vinette, Fr.) It is probable that this name has 
been given to this plant from its spines, or barbs. The name Oxycanthus, also given to 
it, indicates a like origin. 

BARILLA. (Soude, Barille, Fr. ; Barilla, Germ.) A crude soda, procured by the 
incineration of the salsola soda, a plant cultivated for this purpose in Spain, Sicily, Sar- 
dinia, and the Canary Islands. In Alicante the plants are raised from seed, which is sown 
at the close of the year, and they are usually fit to be gathered in September following. In 
October the plants are usually burned. For this purpose holes are made in the earth, capa- 
ble of containing a ton or a ton and a half of soda. Iron bars are laid across these cavi- 
ties, and the dried plants, stratified with dry seeds, are placed upon them. The whole is 
set on fire. The alkali contained in the plants is fused, and it flows into the cavity beneath, 
a red-hot fluid. By constantly heaping on plants, the burning is continued until the pits are 
full of barilla ; they are then covered up with earth, and allowed to cool gradually. The 
spongy mass of alkali, when sufficiently cold, is broken out, and, without any further pre- 
paration, it is ready for shipment. Good barilla usually contains, according to Dr. Ure's 
analysis, 20 per cent, of real alkali, associated with muriates and sulphates, chiefly of soda, 
some lime, and alumina, with very little sulphur. Caustic leys made from it were formerly 
used in the finishing process of the hard soap manufacture. 

The manufacture of barilla has greatly declined since the introduction of Le Blanc's 
process for artificially manufacturing soda from common salt. 

The quantity of barilla and alkali imported in 1850 amounted to 34,880 cwts., and in 
1S51 to 45,740 cwts. ; in 1856 the importation was 54,608 cwts. 

BARK. The outer rind of plants. Many varieties of barks are known to commerce, 
but the term is especially used to express either Peruvian or Jesuits' bark, a pharmaceutical 
remedy, or Oak bark, which is very extensively used by tanners and dyers. 
The varieties known in commerce are — 

Cork Bark. (Fr. Liege ; Korh, Germ.) 
Oak Bark. (Tan brut, Fr. ; Eichenrinde, Germ.) 
Peruvian Bark. (Quinquina, Fr. ; Chinarinde, Germ.) 
Quercitron Bark. 
Wattle Bark. 
BARLEY. (Orge, Fr. ; Gerstengraupe, Germ. ; Hordeum, Linn.) This term is sup- 
posed to be derived from hordus, heavy, because the bread made from it is very heavy. 
Barley belongs to the class Endogens, or Monocotyledons ; Glumel Alliance, of Linley : 
natural order, Graminacem. 

There are four species of barley cultivated in this country : — 

1. Hordeum hexastichon. Six-rowed barley. 

2. Hordeum vulgare. The Scotch bere or bigg ; the four-rowed barley. 

3. Hordeum zeocriton. Putney, fan, sprat, or battledore barley. 

4. Hordeum distichon. Two-rowed or long-eared barley. 

Barley and oats are the cereals whose cultivation extends farthest north in Europe. 

The specific gravity of English barley varies from 1*25 to 1'33 ; of bigg from 1-227 to 
1-265 ; the weight of the husk of barley is Y , that of bigg %. Specific gravity of barley 
is 1-235, by Dr. Ure's trials. 1,000 parts of barley flour contain, according to Einhof, 720 
of starch, 56 sugar, 50 mucilage, 36'6 gluten, 12 - 3 vegetable albumen, 100 water, 2-5 phos- 
phate of lime, 68 fibrous or ligneous matter. 

From the examination instituted by the Royal Agricultural Society of England, and car- 
ried out under the directions of Messrs. Way and Ogston, the following results have been 
arrived at : — 

Kind of Barley employed. 

Moisture in 

100 Parts of 



Gravity of 


Ash in 
100 Parts of 
dried Grain. 

Unknown ... 

Chevalier barley 

Ditto - - - - 
Ditto, from Moldavia - 
Ditto - - - - 

Grains of Chevalier barley 


1 -260 
1 -268 


Vol. III.— 9 



The analyses of several varieties gave as the composition of the ashes of the grains 
of barley : — 








Sesquisxide of iron ... 
Sulphuric acid -'-.-- 


Phosphoric acid - - - - 
Chloride of sodium - 














In the " Synopsis of the Vegetable Products of Scotland," by Peter Lawson and Son, 
will be found the best description of all the different varieties of barley ; and, since the 
Lawsonian collection is in the museum of the Koyal Botanic Gardens at Kew, the grains 
can be examined readily by all who take any interest in the subject. A few only of the 
varieties will be noticed. 

The true six-rowed Barley, known also as Pomeranian and as six-rowed white winter 
barley. — This is a coarse barley, but hardy and prolific. It is occasionally sown in France, 
and also in this country, sometimes as a winter and sometimes as a spring barley, and is 
found to answer pretty well as either. 

Naked two-rowed. — Ear long, containing twenty-eight or thirty very large grains, which 
separate from the paleae, or chaff, in the manner of wheat. This variety has been intro- 
duced to the notice of agriculturalists at various times, and under different names, but 
its cultivation has never been carried to any great extent. 

Common Bere, Bigg, or rough Barley. — This variety is chiefly cultivated in the High- 
lands of Scotland, and in the Lowlands on exposed inferior soils. 

Victoria. — A superior variety of the old bigg, compared with which it produces longer 
straw, and is long-eared, often containing 70 or 100 grains in each. Instances have been 
known of its yielding 13 quarters per acre, and weighing as much as 96 lbs. per bushel. 

Beyond these there are, the winter black; the winter white ; old Scottish four-rowed ; 
naked, golden, or Italian ; Suffolk or Norfolk, and Short-necked ; cultivated in various dis- 
tricts, and with varying qualities. 

BARREGE. A woollen fabric, in both warp and woof, which takes its name from the 
district in which it was first manufactured — the especial locality being a little village named 
Arosons, in the beautiful valley of Barreges. It was first employed as an ornament for the 
head, especially for sacred ceremonies, as baptism and marriage. Paris subsequently be- 
came celebrated for its barreges, but these were generally woven with a warp of silk. 
Enormous quantities of cheap barreges are now made with a warp of cotton. 

BARREL. (Baril, Fr.) A round vessel, or cask, of greater length than breadth, made 
of staves, and hooped. 

The English barrel — wine measure contains 31-J gallons. 
" (old) beer " " 36 " 

(old) ale " " 32 " 

" beer vinegar " 34 " 

" contains 126 Paris pints. 

The ale and beer barrels were equalized to 34 gallons by a statute of William and 
Mary. The wine gallon, by a statute of Anne, was declared to be 231 cubic inches; the 
beer gallon being usually reckoned as 282 cubic inches. 

The imperial gallon is 277"274 cubic inches. 

The old barrels now in use are as follows : — ■ 

Wine barrel 

Ale " (London) .... 
Beer " ".....« 

Ale and beer, for England ... 

The baril de Florence is equivalent to 20 bottles. 

The Connecticut barrel for liquors is 31£ gallons, each gallon to contain 231 cubic inches. 

The statute barrel of America must be from 28 to 31 gallons. 

The barrel of flour, New York, must contain either 195 lbs. or 228 lbs. net weight. 

The barrel of beef or pork in New York and Connecticut is 200 lbs. 

A barrel of Essex butter is 106 lbs. 

A barrel of Suffolk butter is 256 lbs. 

A barrel of herrings should hold 1,000 fish. 

A barrel of salmon should measure 42 gallons. 

26J imperial gallons. 

33 s 7 69 

36 36 / 69 

34 3 V 69 



BAROMETER. A name given to one of the most important instruments of meteo- 
rology. This name signifies a measurer of weight — the column of mercury in the tube of 
the "barometer being exactly balanced against the weight of a column of air of the same 
diameter, reaching from the surface of the earth to the extreme limits of the atmosphere. 
The length of this column of mercury is never more than thirty-one inches ; below that 
point it may vary, according to conditions, through several inches. 

There have been many useful applications of the barometer, but the only one with which 
this dictionary has to deal appears to be the following : — 

Barometer, MadkmortKs Underground. — In the goafs, or old workings, of some mines, 
hollows exist, in which explosive or noxious gases tend to accumulate in considerable quan- 
tity. When the barometer falls, these gases expand and approach or enter the working 
places of the mine, producing disastrous results to life or health. To enable the manager 
of a mine to foresee these contingencies, he has but to construct a small model of such a 
cavity, and let the expansion or contraction of the gas measure itself. In fig. 49, a is a 


brass vessel, 12 inches long and 1-J inches in diameter, closed at each end. In one end is 
inserted a copper tube, \ inch in diameter and 12 feet long, b. A hole, 2 inches in diam- 
eter, being bored 12 feet deep into the solid coal or rock, the brass vessel is pushed to the 
bottom of it, and the small tube is closely packed round with coal or clay, c is a glass 
tube, 4 feet long and \ inch in diameter, in which is placed water or oil. As the external 
atmosphere presses, the surface of the liquid rises or falls, and the scale is graduated by 
comparison with a standard barometer. The air contained in the brass vessel a, and copper 
tube b, is unaffected, or nearly so, by temperature, and no correction has to be made for the 
latter as in the sympiesometer. a and b may be conveniently filled with nitrogen, to pre- 
vent the oxidation of the metal ; and the surface of the liquid in the glass tube may be 
made self-registering, either giving maxima and minima, or, by the addition of clock-work, 
taking diagrams on paper. 

BARWOOD. Although distinctions are made between sandal or saunders wood, cam- 
wood, and barwood, they appear to be very nearly allied to each other — at least, the color- 
ing matter is of the same composition. They come, however, from different places. 

MM. Girardin and Preisser thus describe this wood : — 

This wood, in the state of a coarse powder, is of a bright-red color, without any odor or 
smell. It imparts scarcely any color to the saliva. 

Cold water, in contact with this powder, only acquires a fawn tint after five days' macer- 
ation. 100 parts of water only dissolve 2-21 of substances consisting of - 85 coloring 
matter and of 1-36 saline compounds. Boiling water becomes more strongly colored of a 
reddish yellow ; but, on cooling, it deposits a part of the coloring principle in the form of 
a red powder. 100 parts of water at 212° dissolve 8-86 of substances consisting of '7 - 24 
coloring principle, and 1-62 salts, especially sulphates and chlorides. On macerating the 
powder in strong alcohol, the liquid almost immediately acquires a very dark vinous red 
color. To remove the whole of the color from fifteen grains of this powder, it was neces- 
sary to treat it several times with boiling alcohol. The alcoholic liquid contained 0'23 of 
coloring principle and 0-004 of salt. Barwood contains, therefore, 23 per cent, of red 
coloring matter ; whilst saunders wood, according to Pelletier, only contains 16-75. 

The alcoholic solution behaves in the following manner towards re-agents : — 
Distilled water added in great quantity - Produces a considerable yellow opalescence. The 

precipitate is re-dissolved by the fixed alkalies, 
and the liquor acquires a dark vinous color. 

Fixed alkalies Turn it dark crimson, or dark violet. 

Lime water Ditto. 

Sulphuric acid Darkens the color to a cochineal red. 




Sulphuretted hydrogen - Acts like water. 

Salt of tin Blood-red precipitate. 

Chloride of tin - - - - - Brick-red precipitate. 

Acetate of lead - ' - - - - Dark violet gelatinous precipitate. 

Salts of the protoxide of iron - - Very abundant violet precipitates. 

Copper salts ----- Violet-brown gelatinous precipitates. 

Chloride of mercury - An abundant precipitate of a brick-red color. 

Nitrate of bismuth - Gives a light and brilliant crimson red. 

■Sulphate of zinc Bright-red flocculent precipitate. 

Tartar emetic An abundant precipitate of a dark cherry color. 

Neutral salts of potash - - - - Acts like pure water. 

Water of barytes ----- Dark violet-brown precipitate. 

Gelatine ------ Brownish-yellow ochrous precipitate. 

Chlorine ------ Brings back the liquor to a light yellow, with a 

slight yellowish-brown precipitate, resembling 
hydrated peroxide of iron. 

Pyroxylic spirit acts on barwood like alcohol, and the strongly colored solution behaves 
similarly towards re-agents. Hydrated ether almost immediately acquires an orange-red 
tint, rather paler than that with alcohol. It dissolves 19-47 per cent, coloring principle. 
Ammonia, potash, and soda, in contact with powdered barwood, assume an extremely dark 
violet-red color. These solutions, neutralized with hydrochloric acid, deposit the coloring 
matter in the form of a dark reddish-brown powder. Acetic acid becomes of a dark-red 
color, as with saunders wood. 

Barwood is but slightly soluble ; but the difficulty arising from its slight solubility is, 
according to Mr. Napier, overcome by the following very ingenious arrangement : — The 
coloring matter while hot combines easily with the proto-compounds of tin, forming an 
insoluble rich red color. The goods to be dyed are impregnated with proto-chloride of tin 
combined with sumach. The proper proportion of barwood for the color wanted is put into 
a boiler with water, and brought to boil. The goods thus impregnated are put into this 
boiling water containing the rasped wood, and the small portion of coloring matter dissolved 
in the water is immediately taken up by the goods. The water, thus exhausted, dissolves a 
new portion of coloring matter, which is again taken up by the goods, and so on till the tin 
upon the cloth has become (if we may so term it) saturated. The color is then at its bright- 
est and richest phase. 

In 1855, the quantity of barwood imported, duty free, was 2,710 tons. 

Of the barwood imported, 22*7 tons were re-exported; the computed real value of which 
was £1,241. 

BARYTA, CARBONATE OF. The composition of the native carbonate of baryta 
may be regarded as baryta 11-59 and carbonic acid 22-41. It is found in Shropshire, Cum- 
berland, "Westmoreland, and Northumberland. The carbonate of baryta is employed in our 
color manufactories as a base for some of the more delicate colors ; it is also used in the 
manufacture of plate-glass ; and, in France, it is much used in the preparation of beet-root 


Tons. cwts. 

Alston Moor produced, in 1856 -..--- 443 16 

Fallowfield (Northumberland) ditto 1,045 18 

BARYTA, SULPHATE OF. The baryte of Brooke and Miller, barytes of Dana and 
Phillips, Bolognian spar, called also " cawk" and " heavy spar." It is composed of baryta 
65-63, sulphuric acid 34-37, with sometimes a little iron, lime, or silica. 

This salt of baryta is very extensively spread over various parts of the islands. It is 

worked largely in Derbyshire, Yorkshire, Shropshire, and the Isle of Arran. In 1856 the 

production was as follows : — From 


Derbyshire 8,000 

Shropshire - 1,200 

Bantry (Ireland) 700 

Isle of Arran 550 

Kirkcudbright 70 

It might be obtained in very large quantities in Devonshire, Cornwall, and other places, 
if the demand for it sufficiently increased the price so as to render the working of it profit- 
able. A large quantity of the ground sulphate of baryta is employed in the adulteration 
of white lead. Paint containing much barytes very soon washes off the surface upon which 
it is spread. Lead combines with the oil, and forms, indeed, a plaster. No such combina- 
tion takes place between the oil and the baryta, hence they soon separate by the action of 
water. Baryta is employed to some extent in the pyrotechnic art, in the production of 
flames of a greenish character. 



■ 494 

In 1856 we imported — 

Baryta, sulphate (ground) ------- 

And in the same year we exported — 

Cwts. Declared Value. 

Barytes (sulphate and carbonate) - - - 67,751 - - £12,145 

BASALT. One of the most common varieties of trap rock. It is a dark green or 
black stone, composed of augite and felspar, very compact in texture, and of considerable 
hardness, often found in regular pillars of three or more sides, called " basaltic columns." 
Remarkable examples of this kind are seen at the Giant's Causeway, in Ireland, and at Fin- 
gal's Cave, in Staffa, one of the Hebrides. The term is used by Pliny, and is said to come 
from basal, an Ethiopian word signifying iron. The rock sometimes contains much iron. — 
LyelVs Principles of Geology. Experiments have been made on a large scale to apply 
basaltic rock, after it has undergone fusion, to decorative and ornamental purposes. Messrs. 
Chance (brothers) of Birmingham, have adopted the process of melting the Rowley rag, a 
basaltic rock forming the plateau of the Rowley hills, near Dudley, South Staffordshire, and 
then casting it into moulds for architectural ornaments, tiles for pavements, &c. Not only 
the Rowley rag, but basalt, greenstone, whinstone, or any similar mineral, may be used. 
The material is melted in a reverberatory furnace, and when in a sufficiently fluid state is 
poured into moulds of sand eneased in iron boxes, these moulds having been previously 
raised to a red heat in ovens suitable for the purpose. The object to be attained by heating 
the moulds previous to their reception of the liquid material, is to retard the rate of cool- 
ing ; as the result of slow cooling is a hard, strong, and stony substance, closely resembling 
the natural stone, while the result of rapid cooling is a dark brittle glass. 

BASILICON. The name given by the old apothecaries to a mixture of oil, wax, and 
resin, which is represented by the Cerat. resirue of the present day. 

BASSORA GUM. A gum obtained from the Acacia lewcophlaa, brought from Bas- 
sora. It has a specific gravity of 1 - 3591, and is yellowish white in color. 

BASKETS. Weaving of rods into baskets is one of the most ancient of the arts 
amongst men ; and it is practised in almost every part of the globe, whether inhabited by 
civilized or savage races. 

Basket-making requires no description here. 

Importations : — 

In 1856 we imported of rods peeled for basket-making, 123,103 bundles, value £12,309 
" " rodsunpeeled " 157,146 " " 7,858 

" " baskets, - - - 176,730 cubic feet, " 37,580 

Of these, 152,777 cubic feet were from France. 

BATH METAL consists of 3 oz. of zinc to 1 lb. of copper. 

BATHS. Public baths and wash-houses have now become common amongst us, and with 
them an increased cleanliness is apparent, and improved health throughout the population. 

The following is a return of the bathing and washing at the public baths and wash-houses 
in London, conducted under or in accordance with the Acts 9 and 10 Vict., cap. 74, and 10 
and 11 Vict., cap. 61, and of a few out of the similar establishments in the country : — 

Name of Establishment. 

Number of 

Number of 



1. The Model, Whitechapel - 

2. St. Martin's-in-the-Fields - 

3. St. Marylebone - - - - - 

4. St. Margaret and St. John, Westminster 

5. Greenwich - 

6. St. James, Westminster - 

7. Poplar ------ 

8. St. Giles's and Bloomsbury 











£ s. a. 
2,976 7 8 
3,007 5 10 
2,498 2 3 
2,204 12 5 

995 11 4 
2,038 10 11 

845 15 10 
1,546 3 



16,112 9 3 

Liverpool: — 

Cornwallis Street - 

Paul Street 

George's Pier-head - 
Hull .... . 
Bristol ------- 

Birmingham ------ 

Maidstone --.--. 





1,561 3 2 
797 4 4 

1,684 5 6 
612 8 7 
599 11 2 
405 10 5 

1,854 14 5 
34S S 10 



The return does not include the George Street (Hampstead Road) and Lambeth estab- 
lishments, which are not regulated by the public acts. 

The steady increase of the revenue derived from the baths and wash-houses in London, 
from the commencement of the undertaking in 1846, shows the practical utility of these 
institutions, and their effect on the physical and social condition of the industrious classes • 

The aggregate receipts of nine establishments, inclusive of the 
George Street establishment, during 1853, amount to 

1852. Eight establishments - . 

1851. Six establishments ------- 

1850. Four establishments 

1849. Three establishments -----._ 

1848. Two establishments 

1847. I - 
1846. J 


£ s. 


18,213 5 


15,629 5 


12,906 12 


9,823 10 


0,379 17 


2,896 5 


3,222 1 


-are extending in every 

Showing an increase, in 1853 over 1846, of £15,317 0s. 'id. 

Those conveniences — now, indeed, become absolute necessities- 
part of the country. 

Baths, as curative agents, are of very different kinds. Vapor Baths are stimulant and 
sudorific ; they may be either to be breathed, or not to be breathed. Dr. Pereira has given 
the following Table, as a comparative view of the heating powers of vapor and of water : — 

Kind of Batb. 



Not breathed. 


Tepid bath .... 
"Warm bath .... 
Hot bath 

85° to 92° 
92 " 98 
98 " 106 

96° to 106° 
106 " 120 
120 " 160 

90° to 100° 
100 " 110 
110 " 130 

Local vapor baths are applied in affections of the joints, and the like. 

Vapor douche is a jet of aqueous vapor directed on some part of the body. 

Medicated vapor baths are prepared by impregnating vapor with the odors of medicinal 

Sulphur, chlorine sulphurous acid, iodine, and camphor, are occasionally employed in 
conjunction with aqueous vapor. 

Warm, tepid, and hot baths are sufficiently described above. 

BAY SALT. The larger crystalline salt of commerce. 

BAY, THE SWEET. (Laurus nobilis.) Bay leaves have a bitter aromatic taste, and 
an aromatic odor, which leads to their use in cookery. 

BAYS, OIL OF. This oil is imported in barrels from Trieste. It is obtained from the 
fresh and ripe berries of the bay tree by bruising them in a mortar, boiling them for three 
hours in water, and then pressing them. When cold, the expressed oil is found floating on 
the top of the decoction. Its principal use is in the preparation of veterinary embroca- 

BEADS. {Grain, Fr. ; Bcthe, Germ.) Perforated balls of glass, porcelain, or gems,, 
strung and worn for ornaments ; or, amongst some of the uncivilized races, employed 
instead of money. 

Glass beads have long been made in very large quantities in the glass-houses of Murano, 
at Venice. 

Glass tubes, previously ornamented by color and reticulation, are drawn out in proper 
sizes, from 100 to 200 feet in length, and of all possible colors. Not less than 200 shades 
are manufactured at Venice. These tubes are cut into lengths of about two feet, and then, 
with a knife, they are cut into fragments, having about the same length as their diameter. 
The edges of these beads are, of course, sharp ; and they are subjected to a process for 
removing this. Sand and wood-ashes are stirred with the beads, so that the perforations 
may be filled by the sand ; this prevents the pieces of glass from adhering in the subse- 
quent process, which consists in putting them into a revolving cylinder and heating them. 
The finished beads are sifted, sorted in various sizes, and strung by women for the market. 

In the Jurors' Report of the Great Exhibition of 1851 are the following remarks on this 
manufacture : — 

" The old Venetian manufactures of glass and glass wares fully sustain their importance ; 
and those of paper, jewellery, wax-lights, velvets, and laces, rather exceed their ordinary 
production. The one article of beads employs upwards of 5,000 people at the principal 
fabric on the island of Murano ; and the annual value is at least £200,(100. They are ex- 



ported to London, Marseilles, Hamburg, and thence to Africa and Asia, and the great East- 
ern Archipelago." 

The perles a la lune are a finer, and, consequently, more expensive bead, which are 
prepared by twisting a small rod of glass, softened by a blowpipe, about an iron wire. 

The preparation and cutting of gems into beads belong especially to the lapidary. The 
production of beads of Paste, and of artificial Pearls, will be noticed under those heads 

In India beads of rock crystal are often very beautifully cut. 

Dr. Gilchrist states : — Coral beads are in high estimation throughout Hindostan for 
necklaces and bracelets for women. These beads are manufactured from the red coral 
fished up in various parts of Asia ; they are very costly, especially when they run to any 
size ; and they are generally sold by their weight of silver. 

Coral beads were always favorite articles for ornament even in this country ; and in the 
" Illustrations of Manners' and Expences of antient Times in England," by Nicholls, 1798, 
we find the following entries from " the churchwardens' accompts of St. Mary Hill, London," 
containing " the inventory of John Port, layt the king's servant, as after followeth :" — 
" Item of other old gear found in the house : — - - - - £ s. d. 

" Item one oz. and $ of corall 026 

" Jewels for her body. 

" Item, a pair of coral beds, gaudyed with gaudys of silver and gilt, 

10 oz. at 3s. 4d 1 13 4." 

(John Port died in 1524.) 

We imported, in 1856, of coral beads, 2,279 lbs., and of jet beads, 9 lbs. ; while of 
other kinds unenumerated, 14,281 lbs. were brought into the United Kingdom. 

In addition to those, the following were our Imports of glass beads and bugles : — 

Computed real value, 
lbs. £ 

Denmark 8,889 - - - 1,111 

Hanse Towns 541,580 - - - 67,697 

Holland 37,446 - - - 4,681 

Belgium 25,704 - - - 3,213 

France 6,835 ... 854 

Sardinia 18,949 ... 947 

Tuscany 10,432 - - . - 522 

Austrian Italy .... 1,493,452 - - - 74,673 

Other parts 14,306 - - - 1,564 

2,157,593 £155,262 

We exported, in 1856, ornamental beads to the value of £21,504. 
BEAVER, THE. {Castor Fiber.) This animal is captured for its skin, and for the 
castor, (castorcum,) which is employed medicinally. See Furs. 

BEBIRINE, or BEBEERINE. (C 38 H 21 N0 6 .) An alkali discovered by Dr. Rodie, of 
Demerara, in the bark of the bebeern tree. It was examined more minutely by Madagan 
and Tilley, and still more recently by Von Planta, who has determined its true formula. It 
is very bitter, and highly febrifuge. 

BEECH. (Metre commun, Fr. ; Gemeine Buche, Germ.) The beech tree (the Fagus 
silvatica of Linnaeus) is one of the most magnificent of the English trees, attaining, in about 
sixty or seventy years in favorable situations, a height of from 70 to 100 feet, and its trunk 
a diameter of five feet. The wood, when green, is the hardest of British timbers, and its 
durability is increased by steeping in water ; it is chiefly used by cabinet-makers, coopers, 
coach-builders, and turners. A substitute for olive oil has been extracted from beech nuts. 
BELLADONNA. (Belledame, Fr.) The Atropa Belladonna, or deadly nightshade. 
BELL-METAL ORE. Sulphide of Tin. (Main sulphure, Haiiy ; Zinnkies, Haus- 

The composition of the ordinary variety of this ore is, 

Copper 30-0 

Iron 12-0 

Tin 26-5 

Sulphur 30-5 

It is found in many of the Cornish mines, and especially at those of Cam Brea. 

BEN NUTS. (Ben noix, Fr. ; Salbnusse, Germ.) The tree which furnishes these nuts 
is the Guitandina moringa of Linnaeus, a native of India, Ceylon, Arabia, and Egypt. 

BEN OIL. The oil of ben, which may be obtained from the decorticated nuts, is said 
to be far less liable than other oils to become rancid, and hence it is much used by watch- 


makers. At a low temperature, the oil of ben separates into two parts — one solid and one 
fluid ; the latter only is used for watch-work. On account of its freedom from rancidity, 
oil of ben is used by Parisian perfumers to form the basis of the huiles antiques of tube- 
rose, jasmin, &c. See Oils. 

BENZOIC ACID. (C H H 5 3 .) This acid may be obtained by placing benzoin powdered 
with sand in an evaporating basin, and above it a paper cap ; on applying heat carefully to 
the sand, acid vapors arise from the resin, and they are deposited in the form of fine light 
crystals with the paper cap. Stolze recommends the following process for extracting the 
acid : — The resin is to be dissolved in three parts of alcohol, the solution is to be introduced 
into a retort, and a solution of carbonate of soda dissolved in dilute alcohol is to be gradu- 
ally added to it, till the free acid be neutralized ; and then a bulk of water equal to double 
the weight of the benzoin is to be poured in. The alcohol being drawn off by distillation, 
the remaining liquor contains the acid, and the resin floating upon it may be skimmed off 
and washed, when its weight will be found to amount to about 80 per cent, of the raw ma- 
terial. The benzoin contains traces of a volatile oil, and a substance soluble in water, at 
least through the agency of carbonate of potash. There are several other methods for 
obtaining benzoic acid, described in Ure's " Dictionary of Chemistry." Benzoic acid has no 
special use in the arts. 

BENZOLE. Syn. Benzine, benzene, benzol, hydruret of phenyle, (C 12 H 6 .) The more 
volatile portion of coal naphtha has been shown by Mansfield to consist chiefly of this sub- 
stance. It is produced in a great number of reactions in which organic bodies are exposed 
to high temperatures. It may at once be obtained in a state of purity by distilling benzoic 
acid with excess of quicklime. The lime acts by removing two equivalents of carbonic acid 
from the benzoic acid. The method of obtaining benzole from coal naphtha will be found 
fully described under the head of Naphtha Coal. Benzole is also contained in consider- 
able quantity in bone oil ; but it is accompanied by peculiar nitrogenized volatile fluids, 
which are difficult of removal. The latter, owing to their powerful and fetid odor, greatly 
injure the quality of the bone-oil benzole. Benzole is an exceedingly volatile fluid, boiling 
at ordinary pressures at 187° F. Its density is 0-850. Owing to the levity of benzole 
being regarded by manufacturers as a proof of its purity, it is not uncommon to find it 
adulterated with the naphtha from the Torbanehill mineral, or Boghead coal, which has a 
density as low as 0'150. Any benzole having a lower density than - 850 is impure. Ben- 
zole is excessively inflammable, and its vapor mixed with air is explosive. Numerous lives 
have been lost owing to these properties, among them that of Mr. Mansfield, to whom we 
are indebted for an excellent investigation on coal naphtha. Benzole is greatly used in 
commerce, owing to its valuable solvent properties. It dissolves caoutchouc and gutta percha 
readily, and, on evaporation, leaves them in a state well adapted for water-proofing and many 
other purposes. Its power of dissolving fatty, oily, and other greasy matters, has caused it 
to become an article of commerce under the name of benzoline. It readily extracts grease 
even from the most delicate fabrics, and, as it soon, on exposure to the air, evaporates 
totally away, no odor remains to betray the fact of its having been used. It dissolves 
readily in very strong nitric acid, and, on the addition of water, it is precipitated as a heavy 
oil, having the composition C 12 H 6 NO'. The latter compound is nitrobenzole ; it is regarded 
as benzole in which one equivalent of hydrogen is replaced by hyponitric acid. Nitroben- 
zole, in a state of tolerable purity, is a pale-yellow oil, having a sweetish taste, and an odor 
greatly resembling bitter almonds. Owing to its comparative cheapness, it is employed in 
perfumery. Nitrobenzole can be prepared with nitric acid of moderate strength, such as is 
ordinarily obtained in commerce ; but it then becomes necessary to distil the acid and the 
hydrocarbon together several times. The product so obtained is darker in color, and in 
other respects inferior to that obtained with highly concentrated acid. By treatment with 
acetate of protoxide of iron, nitrobenzole becomes transformed into aniline. This change 
may be effected, but far less conveniently, by means of sulphide of ammonium. Benzole 
is extremely valuable in many operations of manufacturing chemistry. It dissolves^ several 
alkaloids, and, on evaporation, leaves them in a state of purity. It dissolves quinine, but 
not cinchonine, and may therefore be employed as a means of separation. Morphia and 
strychnine are also dissolved by it, but not in great quantity. To obtain many natural alka- 
loids existing in plants, it is merely necessary to digest the dry extract with caustic potash 
and then with benzole. The latter is to be decanted, and then distilled off on a water-bath. 
The alkaloid will be left behind in a state well adapted for crystallization or other means of 
purification. Benzole is becoming much used as a solvent in researches in organic chemis- 
try. Many substances, such as chrysene and bichloride of naphthaline, crystallize better 
from benzole than from any other solvent. 

Benzole may be employed in many ways for illuminating purposes. It is so easily in- 
flamed that great care is necessary in using it. It does not require a wick to enable it to 
burn. If poured even on an uninflammable surface and a light be applied, it takes fire like 
a train of gunpowder, and burns with a brilliant flame, emitting dense clouds of smoke, 
which, soon condensing into soot, presently fall in a shower of blacks. Even on the sur- 



face of water it burns as freely as anywhere else. If a drachm or two be poured on water 
contained in a pan, and a pellet of potassium be thrown in, the benzole inflames, and rises 
in a column of flame of considerable height. A method of destroying enemies' shipping has 
been founded on this principle. In consequence of the smoky nature of the flame of ben- 
zole, (caused by the comparatively larger percentage of carbon,) it is often convenient to 
burn a mixture of one volume of benzole and two volumes of alcohol. A stream of air 
driven through benzole becomes so inflammable as to serve for the purposes of illumination. 
For this mode of using the hydrocarbon, it should be kept slightly warm to assist its vapor- 
ization. A machine on this principle, of American invention, has been employed to illumi- 
nate houses. The air is driven through the benzole by a very simple contrivance, the 
motive power being a descending weight. 

When quite pure, benzole freezes at 32° to a beautiful snow-white substance, resembling 
camphor. The mass retains a solid form until a temperature of 40° or 41° is reached. 
This property of solidifying under the influence of cold may be made use of to produce 
pure benzole from the more volatile portion of coal naphtha. To obtain it perfectly pure, 
it should be frozen at least three times, the portion not solidifying being removed by filtra- 
tion through calico. The unfrozen portion contains hydrocarbons, homologous with olefiant 

Benzole dissolves free iodine and bromine, and has even been used in analysis to sepa- 
rate them from kelp and other substances containing them. They must of course be set 
free before acting with the hydrocarbon. The presence of benzole in mixtures may easily 
be demonstrated, even when present in very small quantity, by converting it into aniline, 
and obtaining the characteristic reaction with chloride of lime. For this purpose the mix- 
ture is to be dissolved in concentrated nitric acid and the nitrobenzole precipitated by 
water. The fluid is then agitated with ether, which dissolves the nitrocompound. The 
ethereal solution is mixed with an equal bulk of alcohol and hydrochloric acid : a little 
granulated zinc being added, hydrogen is evolved, and, by acting in a nascent state on the 
nitrocompound, reduces it to the state of aniline. The base is then to be separated by an 
excess of potash, and the alkaline fluid is shaken with ether to dissolve the base. The 
ethereal fluid being evaporated, leaves the aniline. On adding water and then a few drops 
of solution of chloride of lime, the purple color indicative of aniline is immediately pro- 
duced. (Hofmann.) The writer of this article has by this process detected minute traces 
of benzole in mixtures consisting almost entirely of homologues of olefiant gas. — C. G. W. 

BERGAMOT. (Bergamote, Fr.) The Citrus bergamia, a citron cultivated in the centre 
and south of Europe. By distillation from the rind of the fruit is obtained the well-known 
essence of bergamot. This essential oil and the fruit are principally obtained from Flor- 
ence and Portugal. See Oils, Essential. 

BERGAMOT. A coarse tapestry, said to have been invented at Bergamo, in Italy, 
made of ox and goats' hair, with cotton or hemp. 

BERRY. The term is commonly applied, not only to small fruit, but in some cases to 
seeds. The following is Professor Lindley's definition of a berry :— " A succulent or pulpy 
fruit containing naked seeds, or, in more technical language, a succulent or pulpy pericarp, 
or seed-vessel without valves, containing several seeds, which are naked, that is, which have 
no covering but the pulp and rind. It is commonly round or oval. But in popular lan- 
guage, berry extends only to smaller fruits, as strawberry, gooseberry, &c, containing seeds 
or granules. An indehiscent pulpy pericarp, many-celled and many-seeded ; the attach- 
ment of the seeds lost at maturity, and the seeds remaining scattered in the pulp." 

Berries are used in some of the processes of manufacture, but they are not of much 

Bay Berries. — The fruit of the Laurus nobilis, or the sweet bay. Both the leaves and 
the fruit are employed as flavorings. A volatile oil, the oil of sweet bay, is obtained by dis- 
tillation with water ; and a fixed oil, by bruising the berries, and boiling them for some 
hours in water ; this oil, called also Laurel fat, is imported from Italy. 

Turkey Yellow Berries. — The unripe fruit of the Rhamnus infectorius. They are 
used in calico-printing, producing a lively but fugitive yellow color. 

Persian Yellow Berries. — These are said to be produced by the same species of plant ; 
but the color is considered more permanent, and they fetch higher prices. 

Berries of Avignon. — Another name given to the Turkey and Persian berries. 

Juniper Berries. — The fruit of the Juniperus communis. They are chiefly used for 
flavoring gin and some spirituous cordials, and in the preparation of some pharmaceutical 
articles, as the oil of juniper and the compound spirits of juniper. 

Bear Berry. — The fruit of the Uva ursi. The leaves only are used medicinally. 

Myrobolans. — The fruit of a tree which grows in India. It has a pale-yellow color 
when new, but becomes darker by age, and then resembles dried plums. It contains tannin, 
and has hence been used in dyeing. 

BERTHOLLETIA. A plant of the natural order Lecytlddem, the Bertholleiia cxcclsa. 
It is a tree of large dimensions, forming extensive forests on the banks of the Orinoco. 

138 BERYL. 

The Portuguese of Para have for a long time driven a great trade with the nuts of this tree, 
which the natives call luvia, and the Spaniards Ahncndron. They send cargoes to French 
Guiana, whence they are shipped for England and Lisbon. The kernels yield a large quan- 
tity of oil well suited for lamps. — Humboldt and Bonpland. 

BERYL. (Beril, Fr. ; Beryl, Germ. ; Smaragd, Ital.) A beautiful mineral or gem, 
usually of a green color of various shades, passing into honey yellow and sky blue. 

Beryl and emerald are varieties of the same species, the latter including the rich green 
transparent specimens which owe their color to oxide of chrome ; the former those of other 
colors produced by oxide of iron. Gmelin gives the composition of beryl as : — 

Silica 69-10 

Alumina l^GO 

Glucine - < 13-39 

Bed oxide of iron - 24 

" Beryls of gigantic size have been found in the United States, at Acworth and Grafton, 
New Hampshire, and Royalston, Mass. One beryl from Grafton weighs 2,900 lbs. ; it is 32 
inches through in one direction, and 22 in another transverse, and is 4 feet 3 inches long. 
Another crystal from this locality, according to Professor Hubbard, measures 45 inches by 
24 in its diameters, and a single foot in length, by calculation, weighs 1,076 lbs., making 
it, in all, nearly 2-J- tons. At Royalston, one crystal exceeded a foot in length." — Dana. 

False Beryls of Commerce. — Some of the natural crystals of phosphate of lime are 
introduced as beryls. The Apatite is sometimes called the Saxony beryl. The Chrysolite, 
known by the Germans as the Pierre dAsperge, is also sold as the beryl. 

Fluor spars of different colors are sold as false beryls, false emeralds, false amethysts, 
and false topazes. These are filiate of lime. 

BETEL. A compound, in universal use in the East, consisting of the leaf of the betel- 
pepper, with the betel-nut, a little catechu, and some chunam, (lime obtained by calcining 
shells.) This is almost universally vised throughout central and tropical Asia ; the people 
are unceasingly masticating the betel. 

BETEL-LEAF. The leaf of the pepper vine, {Piper betel.) This plant is extensively 
cultivated throughout tropical Asia, and forms a large and important article of Eastern 

BETEL-NUT, or ARECA. The fruit of the Areca catechu, which is eaten both in its 
ripe and its unripe state. 

BEUHEYL. A mining term, signifying a living stream. It is applied by the tin- 
miners to any portion of a lode or of the rock which is impregnated with tin. 

BEZOAR. (The most probable etymology of the word is from the Persian Pddzaler, 
i. e. expelling poison. — Penny Cyclopaedia.) A concretion found in the stomach of ani- 
mals of the goat kind ; it is said to be especially produced by the Capra gazella. The 
finest bezoar is brought to India from Borneo and the shores of the Persian Gulf. The 
Capra yE'gagrus, or wild goat of Persia producing this concretion, which, by way of emi- 
nence, was called the Lapis bezoar orientalis. The bezoars, which were supposed to cure 
all diseases, have been found, by the analysis of Fourcroy and Vauquelin and of Proust, to 
be nothing more than some portions of the food of the animal agglutinated into a ball with 
phosphate of lime. 

Fossil bezoar is found in Sicily, in sand and clay pits. They are concretions of a purple 
color around some, usually organic, body, and the size of a walnut. Fossil bezoar is some- 
times called Sicilian earth ; and it appears to be of a similar character to Armenian bole. 

Bezoar Mineral. — An old preparation of the oxide of antimony. 

BICARBONATES. The ordinary carbonates of potash and soda have a strong alkaline 
reaction and caustic taste, making them unfit for many purposes where a soluble carbonate 
is required. Moreover, there are many uses to which they are applied, rendering it de- 
sirable that as large an amount of gas as possible should be given off on the addition of a 
stronger acid. 

Bicarbonate of Potash. — There are several modes of converting the carbonate into 
bicarbonate. The most economical is by exposing the salt to a current of carbonic acid. 
For this purpose some manufacturers place it, slightly moistened, on stoneware trays, and 
allow the vapors of burning eoke to travel slowly over it. The sources of the gas used in 
this manufacture will vary according to the locality in which it is undertaken. It is not 
unusual to produce it by the action of sulphuric acid on limestone. The gas generated in 
fermentation has been employed, and even that which in some places issues from the earth. 
The bicarbonate of potash is far less soluble than the carbonate, as it requires four parts of 
cold water for solution, whereas the carbonate dissolves in - 9 of its weight of water at 54° 
F. Consequently, if a strong solution is saturated with carbonic acid, the bicarbonate crys- 
tallizes out. When common pearl ashes are dissolved in water, and the gas is passed in, a 
large quantity of a white precipitate is often thrown down ; it consists chiefly of silica, but 
often contains alumina and other matters. Considerable heat is developed when moistened 



carbonate of potash is exposed to a current of carbonic acid gas. When carbonate of pot- 
ash is dissolved in water, and gradually treated with acetic acid, so as to form acetate of 
potash, by no means the whole of the carbonic acid is expelled, and a point is arrived at 
when a considerable quantity of crystals is deposited ; they consist of very pure bicarbonate 
of potash. In making acetate of potash on the large scale, the quantity of crystalline pre- 
cipitate obtained in this manner is sometimes very large. Bicarbonate of potash is usually 
tolerably pure. If well crystallized, all the impurities remain in the mother-liquor, and on 
heating to redness almost exactly the theoretical amount of residue is left, viz. 69'05 per 
cent. Crystallized bicarbonate of potash always contains one equivalent of water, its 
formula being KO, 2C0 2 + HO. 

Bicarbonate of Soda. — This salt is obtained by the same methods as the salt of potash. 
The crystals have a corresponding formula to the potash salt ; namely, NaO, 2C0 2 -\- HO. 
It requires about 13 parts of water at 60° to dissolve it. When pure, 100 parts leave 63 - 18 
of NaO, CO 2 on ignition. 

The bicarbonates of potash and soda lose carbonic acid by the boiling of an aqueous 

Modern theoretical chemists regard carbonic acid as being bibasic, the true formula 
being C 2 4 , instead of CO'. There can be little doubt that this view is the correct one, and 
it has the advantage of explaining why the bicarbonates are neutral instead of acid salts. 
Moreover, C 2 4 corresponds to 4 volumes, like organic substances generally ; whereas, if we 
assume CO 2 as one atom of the gas, we are compelled to admit a 2-volume formula. — ■ 
C. G. W. 

BIDERT. An Indian alloy of considerable interest, named Bidery from Bider, a city 
X. E. of Hyderabad. Many articles are made, remarkable for elegance of form and for 
gracefully-engraved patterns. Although the groundwork of this composition appears of a 
blackish color, its natural tint is that of pewter or zinc. 

Dr. Heyne says it is composed of, copper, 16 ; lead, 4 ; tin, 2 ; and to every 3 ounces 
of alloy 16 ounces of spelter (that is, of zinc) are added, when the alloy is melted for use. 
To give the esteemed black color and to bring out the pattern, it is dipped in a solution of 
sal ammoniac, saltpetre, common salt, and blue vitriol. Dr. Hamilton saw, zinc, 12,360 
grains ; copper, 400 ; and lead, 414 ; melted together under a mixture of resin and bees' 
wax introduced into the crucible to prevent calcination ; it was then poured into moulds of 
baked clay, and the articles handed over to be turned in a lathe. 

Though called bidery, and sometimes vidry, it is manufactured in other places. In some 
parts of the Nizam's dominions, specimens were obtained, for the Exhibition of 1851, of 
great beauty. 

Bidery does not rust, yields little to the hammer, and breaks only when violently beaten. 
According to Dr. Hamilton, bidery is not nearly so fusible as zinc or tin, but melts more 
easily than copper. — Dr. Boyle, Lecture on the Great Exhibition. 

BlJOUTRY. (Bijouterie, Fr.) Jewellery ; — the manufacture of and dealing in jewel- 
lery. This work is not the place in which to describe the almost endless variety of articles 
which come under this denomination. The principal places for the manufacture, in Eng- 
land, are Birmingham and London. The trade in jewellery forms one of the most impor- 
tant branches of French commerce ; on which a French writer says : — " La bijouterie est 
une des branches les plus importantes du commerce francais, et e'est elle qui constate, de 
la maniere la plus evidente, notre superiorite dans les arts du dessin et les progres toujours 
croissans de 1'industrie Parisienne. Dans cette partie essentiellc, elle n'a pas de rivaux, et 
elle rend tributaire de notre pays presque toute l'Europe, et une grande partie de l'Asie et 
de l'Amerique." 

The ordinary practice has been to divide articles of this character into two principal 
kinds — fine jewellery, and false jewellery, (bijoutier en Jin and bijoutier en faux.) Another 
division, among the French jewellers especially, has been to adopt four classes : 1, fine jew- 
ellery, which is all gold ; 2, silver jewellery ; 3, false jewellery ; and, 4, jewellery of steel 
or iron. 

BISCUITS. The manufacture of fancy biscuits, which in former times was confined to 
the pastry-cook and confectioner, has of late years assumed considerable importance, and 
several firms are now exclusively engaged in this branch of industry, the products of which 
are sold under an extraordinary variety of names. Some of these, namely, the " plain bis- 
cuit, arrow-root, captain, brown meal, cinnamon, caraway, vanilla biscuits," &c, are intelli- 
gible enough ; but, if we except " Abernethy biscuit, maccaroons, and cracknels," with the 
names of which the public, from long usage, are familiar, the rest of the products of the 
modern biscuit maker, " Africans, Jamaica, Queen's routs, ratafias, Bath and other sorts of 
Olivers, exhibition, rings and fingers, pic-nics, cuddy," &c, &c, forms a list of upwards of 
eighty fanciful names, all expressive of articles of different form, appearance, and taste, 
made of nearly the same materials, with but little variation in the proportion in which they 
are used, — the principal ingredients in all being flour and water, butter, milk, eggs, and 
caraway, nutmeg, cinnamon, or mace, or ginger, or essence of lemon, ncroli, or orange- 


flower water, called, in technical language, " flavorings." The kneading of these materials 
is always performed by a kneading or mixing machine. The dough or paste produced is 
passed several times between two revolving cylinders adjusted at a proper distance, so as to 
obtain a flat, perfectly homogeneous mass, slab, or sheet. This is transferred to a stamping 
or cutting machine, consisting of two cylinders, through which the sheet of homogeneous 
paste has to pass, and by which it is laminated to the proper thickness, and at the same time 
pushed under a stamping and docking frame, which cuts it into discs, or into oval or other- 
wise shaped pieces, as occasion may require. The stamps or cutters in the frame being 
internally provided with prongs, push the cut pieces of dough, or raw cakes, out of the cut- 
ting frame, and at the same time dock the cakes, or cut pieces, with a series of holes, for 
the subsequent escape of the moisture, which, but for these vents, would distort and spoil 
the cake or biscuit when put in the oven. The temperature of the oven should be so regu- 
lated as to be perfectly uniform, neither too high nor too low, but just at such a heat as is 
sufficient to give the biscuits a light brown color. For such a purpose the hot water oven 
of Mr. Perkins, or that of Mr. Eoland, is the best that can possibly be used. (See Bread.) 
Poland's oven offers the peculiar advantage that, by turning the screw, the sole of the oven 
can be brought nearer to the top, and a temperature is thus obtained suitable for baking 
thoroughly, without burning, the thinnest cakes. 

One of the most curious branches of the baker's craft is the manufacture of ginger- 
bread, which contains such a proportion of molasses that it cannot be fermented by means 
of yeast. Its ingredients are flour, molasses or treacle, butter, common potashes, and alum. 
After the butter is melted, and the potashes and alum are dissolved in a little hot water, 
these three ingredients, along with the treacle, are poured among the flour which is to form 
the body of the bread. The whole is then incorporated by mixture, and kneading into a 
stiff dough. Of these five constituents the alum is the least essential, although it makes 
the bread lighter and crisper, and renders the process more rapid ; for gingerbread, dough 
requires to stand over for several days, some 8 or 10, before it acquires the state of porosity 
which qualifies it for the oven ; the action of the treacle and alum on the potashes, in 
evolving carbonic acid, seems to be the gassifying principle of gingerbread ; for if carbon- 
ate of potash is withheld from the mixture, the bread, when baked, resembles, in hardness, 
a piece of wood. 

Treacle is always acidulous. Carbonate of magnesia and soda may be used as substitutes 
for the potashes. Dr. Colquhoun has found that carbonate of magnesia and tartaric acid 
may replace the potashes and the alum with great advantage, affording a gingerbread fully 
more agreeable to the taste, and much more wholesome than the common kind, which con- 
tains a notable quantity of potashes. His proportions are : 1 lb. of flour, | of an ounce of 
carbonate of magnesia, and £ of an ounce of tartaric acid, in addition to the treacle, but- 
ter, and aromatics, as at present used. The acid and alkaline earth must be well diffused 
through the whole dough ; the magnesia should, in fact, be first of all mixed with the flour. 
The melted butter, the treacle, and the acid dissolved in a little water, are poured all at 
once amongst the flour, and kneaded into a consistent dough, which being set aside for half 
an hour or an hour, will be ready for the oven, and should never be kept unbaked for more 
than 2 or 3 hours. The following more complete recipe is given by Dr. Colquhoun for 
making thin gingerbread cakes : — Flour 1 lb., treacle \ lb., raw sugar J- lb., butter 2 
ounces, carbonate of magnesia £ ounce, tartaric acid ^ ounce, ginger ^ ounce, cinnamon £ 
ounce, nutmeg 1 ounce. This compound has rather more butter than common thin ginger- 
bread. In addition to these, yellow ochre is frequently added by cheap gingerbread- 
makers, and altogether this preparation, more generally consumed by children, is very 

" Puff-paste " is a preparation of flour and butter, which is in great demand not only at 
the pastry-cooks', but in almost every private family. Take a certain quantity of flour, say 
half a pound, put it upon a wooden board, make a hole or depression in the centre, and 
mix it with somewhat less than half a pint of cold water, so as to make a softish paste ; dry 
it off from the board by shaking a little flour over and under, as is well known, but do not 
" work it " more than you can help. Take now a quarter of a pound of fresh butter, which 
should be as hard as possible, (and therefore it should be kept in as cold a place as practi- 
cable, the ice closet, if procurable, being the best place,) and squeeze out all the water, or 
buttermilk which it contains, by kneading it with one hand on the board. This operation 
is called in French " tnanier le beurre." Roll now the paste prepared as above into a flat, 
thick, square slab, extending about 6 or 7 inches ; lay the pat of butter, treated as above, 
in the middle of the slab of paste, and so wrap the butter up into it by folding the sides of 
the paste all round over it ; roll the whole mass gently with the rolling-pin, so as to form a 
thick sheet, put it upon a tin plate, or tray, cover it with a linen cloth wetted with water 
as cold as possible, and leave the whole at rest for about a quarter of an hour in a cold 
place. At the end of that time, roll the mass with the rolling-pin into a sheet about 1 5 or 
16 inches long, and fold it into three, one over the other; roll it out again into a sheet as 
before, and again fold it into three, one over the other, as before, and repeat this operation 


once more, making three times in all. Put the square mass, with a wet cloth upon it, in a 
cold place for another quarter of an hour, as before, and at the end of that time roll it out 
with the rolling-pin, and fold it into three, one over the other, as above ; and do this once 
more, making five times in all, after which the paste is ready for use. Care must be 
taken, during the rolling, continually to dust the board and the paste with a little flour, to 
prevent sticking. The paste may now be placed in the dish, or tins, in which it is to be " 
baked, taking care to cut the protruding edges with a pointed and sharp knife, so as to 
leave the paste all round with a clean cut edge, for otherwise it will not puff up or swell. 
The thick edges of pies and tarts are made by cutting strips of the paste with the knife, and 
carefully layin°- them on all round, taking care to leave the edges quite sharp. The pre- 
pared articles are then put in an oven, previously brought to a good heat, and the elastic 
vapor disengaged from the butter and water will at once cause the paste to swell into 
parallel layers of great tenacity, and apparently light, but really very heavy, since each of 
these thin laminae is compact and distinct. Puff-paste is indigestible. It is essential to the 
success of the operation, that the floor of the oven should be hot. — A. N. 

BISMUTH. (Bismuth, Fr. ; Bismuth, Germ.) The following are the principal ores of 
bismuth ; the first is the source of the metal used in the arts : — 

Bismuth, Native, is whitish, with a faint reddish tinge, and a metallic lustre which is 
liable to tarnish. Streak, silver-white. Hardness, 2 to 2'5 ; specific gravity, 9-121. It is 
brittle when cold, but slightly malleable when heated. It generally occurs in a dendritic 
form. It fuses readily at H6 n F. Beautiful crystals can be formed artificially by fusion 
and subsequent slow cooling. 

Native bismuth has been found associated with other minerals : in Cornwall, at Huel 
Sparnon, near Redruth, when that mine was worked ; at Trugoe Mine, near St. Colomb, 
(Gregg,) and at the Consolidated Mines, St. Ives, Caldbeck Fells, in Cumberland, with ores 
of cobalt. 

Bismuthine, or sulphuret of bismuth, occurs either in acicular crystals, or with a foli- 
ated, fibrous structure. It is isomorphous with stibnite. Hardness, 2 to 2-5 ; specific 
gravity, 6 - 4 to 6'9. It is composed of bismuth, 81 - 6 ; sulphur, 18-4. It fuses in the flame 
of a candle. 

Bismuthine occurs in Cornwall, at Botallack, and associated with tin at St. Just, and 
with copper at the mines near Redruth and Camborne. 

Bismuth Ochre. — A dull earthy mineral, found in the Royal Restormel Iron Mine, and 
in small quantities in the parish of Roach, in Cornwall. Its composition is stated by Lam- 
padius to be : — 

Oxide of bismuth 86 - 4 

Oxide of iron - 54 

Carbonic acid 44 

Water 34 

Telluric Bismuth. — Tetradymite, — occurs in Cumberland, at Brandy Gill, Carrock Fells, 
(Gregg.) Its composition is : — 

Bismuth 83-30 

Tellurium 8-65 

Sulphur 643 

Selenium 1.22 

Acicular Bismuth. — Aikinite — called also Needle Ore, and the plumbo-cupriferous 
sulphide of bismuth — is composed of sulphur, 16 ; bismuth, 34-62; lead, 35-69; copper, 

Carbonate of Bismuth. — Bismutite. This ore is composed of a mechanical mixture of 
the carbonates of bismuth, of iron, and of copper. 

Cupreous Bismuth. — Tannenite, is sulphur, 18-83 ; bismuth, 62-16 ; copper, 18 ,, 72. 

This metal is also found associated with selenium and tellurium. 

Bismuth may be regarded as the most remarkable of the dia-magnetic bodies, standing, 
indeed, at the head of the class, in the same way as iron does at the head of the magnetic 
order of substances.* 

In Ure's " Dictionary of Chemistry " will be found various methods for the determina- 
tion of bismuth. The following processes, however, appear so useful as to warrant their 
insertion in this place : — To detect small quantities of lead in bismuth, or in bismuth com- 
pounds, Chapman brings the somewhat flattened bead, reduced before the blowpipe, in 
contact with some moist basic nitrate of teroxide of bismuth, when, in a short time, in con- 
sequence of the reduction of the bismuth by the lead, arborescent sprigs of bismuth are 
formed around the test specimen. Since zinc and iron interfere with this reaction, they 
must be previously removed, the former by fusion with soda, the latter with soda and borax, 
in the reducing flame. 

* Consult De la Rive's Treatise on Electricity, translated by Charles V. Walker, F. K. S. 


Lead and bismuth can easily be quantitatively separated from each other by the follow- 
ing method, proposed by Ullgren : — The solution of the two metals is precipitated by car- 
bonate of ammonia, and the carbonates are then dissolved by acetic acid, and a blade of 
pure lead, the weight of which is ascertained beforehand, is plunged in the solution. This 
blade must be completely immersed in the liquor. The vessel is then corked up, and the 
experiment is left for several hours at rest. The lead precipitates the bismuth in the 
metallic form. When the whole of it is precipitated, the blade of lead is withdrawn, 
washed, dried, and weighed. The bismuth is collected on a filter, washed with distilled 
water which has been previously boiled, and cooled out of contact of the air ; this metal is 
then treated with carbonate of ammonia, and the precipitate which is left, after washing and 
ignition, is then weighed. The total loss of the metallic lead employed indicates how much 
oxide of lead must be subtracted from the total weight of the protoxide of lead obtained. — 
E. Peligofs Edition of Rose. 

Oxide of bismuth can be separated, by means of sulphohydric acid, from all the oxides 
which cannot be precipitated from an acid solution by this reagent. Yet, when the precipi- 
tate of sulphide of bismuth is intended to be made by moans of sulphohydric acid, it is 
necessary to take care to dilute with water the solution of the oxide of bismuth. But as 
the solutions of bismuth are rendered milky by water, acetic acid should first be added to 
the liquor, which prevents its becoming turbid when water is poured into it. — Rose. 

BITTER PRINCIPLE. {Amer, Ft. ; Bitterstoff, Germ.) The "bitter principles" 
consist of bodies which may be extracted from vegetable productions by the agency of 
water, alcohol, or ether. These are not of much importance in the arts, with a few ex- 

Lupulin. — For example, the bitter principle of the hop is used for preserving beer. It 
is a reddish-yellow powder, obtained from hops by digestion in alcohol, which is evaporated ; 
then the extract is dissolved in water, and the fluid saturated with lime. This is evaporated, 
and the residuary mass treated with alcohol or ether. 

Quassin is the bitter principle of quassia; Absinthin, that of wormwood ; and Gen- 
tianin, that of gentian, &c. 

BITUMEN, or ASPHALTUM. Bitumen comprises several distinct varieties, of which 
the two most important are asphaltum and naphtha. 

Asphaltum is solid, and of a black, or brownish-black, color, with a conchoidal brilliant 

Naphtha. — Liquid and colorless when pure, with a bituminous odor. 

There are also the earthy, or slaggy mineral pitch — petroleum — a dark-colored fluid 
variety, containing much naphtha, and maltha, or mineral tar. 

Bitumen in all its varieties was known to the ancients. It was used by them, combined 
with lime, in their buildings. Not only do we find the ruined walls of temples and palaces, 
in the East, with the stones cemented with this material, but some of the old Roman cas- 
tles in this country are found to hold bitumen in the cement by which their stones are 
secured. At Agrigentum it was burnt in lamps, and called " Sicilian oil." The Egyptians 
used it for embalming. — Dana. 

Springs of which the waters contain a mixture of petroleum, and the various minerals 
allied to it — as bitumen, asphaltum, and pitch — are very numerous, and are, in many cases, 
undoubtedly connected with subterranean heat, which sublime the more subtle parts of the 
bituminous matters contained in rocks. Many springs in the territory of Modena and 
Parma, in Italy, produce petroleum in abundance ; but the most powerful perhaps yet 
known are those of Irawadi, in the Burman empire. In one locality there are said to be 
520 wells, which yield annually 40,000 hogsheads of petroleum. 

Fluid bitumen is seen to ooze from the bottom of the sea on both sides of the island of 
Trinidad, and to rise up to the surface of the -water. It is stated that, about seventy years 
ago, a spot of land on the western side of Trinidad, nearly half-way between the capital and 
an Indian village, sank suddenly, and was immediately replaced by a small lake of pitch. 
In this way, probably, was formed the celebrated Great Pitch Lake. Sir Charles Lyell 
remarks :— " The Orinoco has for ages been rolling down great quantities of woody and 
vegetable bodies into the surrounding sea, where, by the influence of currents and eddies, 
they may be arrested and accumulated in particular places. The frequent occurrence of 
earthquakes, and other indications of volcanic action in those parts, lend countenance to the 
opinion that these vegetable substances may have undergone, by the agency of subterranean 
fire, those transformations or chemical changes which produce petroleum ; and this may, by 
the same causes, be forced up to the surface, where, by exposure to the air, it becomes 
inspissated, and forms the different varieties of pure and earthy pitch, or asphaltum, so 
abundant in the island." 

The Pitch Lake is one and a half miles in circumference ; the bitumen is solid and cold 
near the shores, but gradually increases in temperature and softness towards the centre, 
where it is boiling. The solidified bitumen appears as if it had cooled, as the surface boiled, 
in large bubbles. The ascent to the lake from the sea, a distance of three-quarters of a 



mile, is covered with a hardened pitch, on which trees and vegetabes flourish ; and about 
Point la Brave, the masses of pitch look like black rocks among the foliage : the lake is 
underlaid by a bed of mineral coal. — Manross, quoted by Dana. 

The Earl of Dundonald remarks, that vegetation contiguous to the lake of Trinidad is 
most luxuriant. The best pine-apples in the West Indies (called black pines) grow wild 
amid the pitch. 

Asphaltum is abundant on the shores of the Dead Sea. It occurs in some of the mines 
of Derbyshire, and has been found in granite, with quartz and fluor spar, at Poldice, in 
Cornwall. There is a remarkable bituminous lime and sandstone of the region of Bechel- 
bronn and Lobsann, in Alsace. From the observations of Daubree, we learn that probably 
this bitumen has had its origin as an emanation from the interior of the earth ; and indeed, 
in Alsace, with the great elevated fissure of the sandstone of the Vosges, a fissure which 
was certainly open before the deposit of the Trias, but was not yet closed during the ter- 
tiary epoch, affording during this latter, moreover, an opportunity for the deposition of 
spathic iron ore, iron pyrites, and heavy spar. — Annates des Mines. 

Elastic Bitumen, called also mineral caoutchouc and elaterite, was first observed in 
Derbyshire, in the forsaken lead mine of Odin, by Dr. Lister, in 16*73, who called it a sub- 
terranean fungus. It was afterwards described by Hatchett. The analysis of this variety, 
by Johnston, gave the following as its composition : — 

Carbon, 85 "47 Hydrogen, 13-28 

Two descriptions of elastic bitumen were analyzed by M. Henry, fils, (" Ann. des Mines.") 
He states the English to have been in brown masses, slightly translucid, of a greenish color, 
soft, elastic, burning with a white flame, and giving off a bituminous odor, and of specific 
gravity 0-9 to L23, and obtained from Derbyshire. 

The French elastic bitumen generally resembled the English, excepting that it was 
opaque, and floated on water. It was discovered at the coal mines of Montrelais. 






1-0000 1-0000 

Of ordinary bitumen, we have analyses of two specimens : one by Ebelmen, who ob- 
tained his sample from the Auvergne ; and the other by Boussingault, which was a Peru- 
vian specimen : — 

Auvergne. Peruvian. 

Carbon 76-13 - - - 88-63 

Hydrogen 9-41 - - - 9'69 

Oxygen 10-34 

Nitrogen ------ 2.32 

Ash 1-80 


32 y 

100-00 100-00 

BLACK BAND. A variety of the carbonates of iron, to which attention was first called 
by Mr. Mushet, at the commencement of the present century. The iron manufacture of 
Scotland owes its present important position to the discovery of the value of the black band 
iron stone. This ore of iron is also found in several parts of the coal basin of South Wales, 
and in the north of Ireland. See Iron. 

Chemical examination of the black band, from the neighborhood of Airdrie, about ten 
miles east of Glasgow, gives the following composition : — 

Carbonic acid - - 35-17 

Protoxide of iron 5303 

Lime 3-33 

Magnesia - . \->jij 

Silica --------- = . . i>40 

Alumina - 63 

Peroxide of iron 0-23 

Bituminous matter 3-03 

Water and loss 1-41 

by calcining bitartratc of potash 

An intimate mixture of charcoal and carbonate of potash, obtained 
Generally, the crude tartar of commerce is used for this 


BLACKING FOR SHOES. According to the " Scientific American," a good paste 
blacking is made of 4 lbs. of ivory black, 3 lbs. of molasses, 9 oz. of hot sperm oil, 1 oz. 
of gum arabic, and 12 oz. of vinegar, mixed together, and stirred frequently for six days • it 
is then fit for use. 

Blacking consists of a black coloring matter, generally bone black, and substances that 
acquire a gloss by friction, such as sugar and oil. The usual method is to mix the bone 
black with sperm oil : sugar, or molasses, with a little vinegar, is then well stirred in, and 
strong sulphuric acid is added gradually. The acid produces sulphate of lime and' acid 
phosphate of lime, which is soluble : a tenacious paste is formed by these ingredients, which 
can be smoothly spread ; the oil serving to render the leather pliable. This forms a liquid 
blacking. Paste blacking contains less vinegar. In Germany, according to Liebig, black- 
ing is made by mixing bone black with half its weight of molasses, and one-eighth of its 
weight of hydrochloric acid, and one-fourth of its weight of strong sulphuric acid, mixing 
with water, to form an unctuous paste. — Report of the Progress of Science and Mechan- 
ism, New York. 

BLAST HOLES. A mining term. The holes through which the water enters the bot- 
tom of a pump in the mines. 

BLEACHING (Blanchement, Fr. ; Bleichen, Germ.) is the process by which the textile 
filaments, cotton, flax, hemp, wool, silk, and the cloths made of them, as well as various 
vegetable and animal substances, are deprived of their natural color, and rendered nearly or 
altogether white. The term bleaching comes from the French verb blanchir, to whiten. 
The word blanch, which has the same origin, is applied to the whitening of living plants by 
causing them to grow in the dark, as when the stems of celery are covered over with 

The true theory of bleaching has not been entirely agreed upon, but there can be little 
doubt of the principal operations. It is known that oxygen deprives substances of color ; 
this may be performed by many high oxides ; by nitric acid, manganic and chromic acids, 
chlorous acid, and even lower oxides which hold their oxygen lightly, as hypochlorous acid. 
The same effect may be produced by chlorine, bromine, and iodine. It has been said that 
chlorine unites with the hydrogen of the water which is present, gives off oxygen, and so 
acts just as oxygen would. Davy found that it would not act in dry air, so that water was 
needful : but Dr. Wilson found that it would act, although slowly, in dry air, if exposed to 
the rays of the sun. This might show that water is not necessary in order to supply oxy- 
gen, but only to allow the chlorine to be brought into thorough contact with the coloring 
matter. It has also been supposed that the chlorine removes the hydrogen, or, rather, sim- 
ply takes its place by an act of substitution. Now, whether the chlorine or the liberated 
oxygen removes the hydrogen, the result will be the same — the destruction of the com- 
pound. Chlorine so readily performs these changes, that we should at once decide on call- 
ing it the active agent, were it not for the fact that oxygen acts so readily, even when 
chlorine is not present : for example, peroxide of hydrogen, as well as the oxides just men- 
tioned, and ozone also, which has no chlorine to help it. It is, then, certain that oxidation 
bleaches ; and it is certain that dehydration bleaches, if performed by chlorine, and that the 
sun aids it by its active rays. We know also that water aids it : water aids bleaching or 
oxidation by air, partly because it contains air in solution. It aids also the bleaching per- 
formed by solutions in contact with porous bodies, because these bodies have a power of 
condensing gases in their pores and of compelling combinations. The next question is, 
Does it aid the bleaching by chlorine in the same way, by assisting the union mechanically, 
or by decomposing water ? Chlorine acts slowly, unless water be present. The theor}', 
therefore, does not demand the decomposition of water, and the known powerful affinities 
of chlorine do not require to be supplemented by oxygen. But, in order to see exactly the 
state of the case, let us look at the action of chlorine in hypochlorites or in chloride of 
lime, and we find that it is a direct oxidation. We obtain by it peroxides of metals, and 
not chlorides. Here we seem to be taught directly by experiment, that bleaching by hypo- 
chlorites is an oxidation of the coloring matter. Bleaching by moist chlorine may there- 
fore be looked on as the same ; indeed, we oxidize by it ; but in such cases we may obtain the 
base at the same time united to chlorine, giving another turn to the question, as Kane 
showed. The oxidation theory, therefore, seems to be sufficient when water is present. 
We are, however, finally to deal with dry chlorine in the sun ; and in that case it is fair to 
conclude that it acts by direct combination with hydrogen or the coloring matter, or both. 
We have, then, two modes of bleaching ; but the usual mode in the air becomes by that 
explanation an oxidation, and the direct action of chlorine obtainable only with difficulty. 
When sulphurous acid is used, another phenomenon may be looked for, as we find a sub- 
stance whose chief quality is that of deoxidizing. The removal of oxygen also decomposes 
bodies, and sulphuretted hydrogen can scarcely be supposed to act in any other way. Sul- 
phurous acid, when it decomposes sulphuretted hydrogen, really acts as an oxidizing agent, 
and we can therefore imagine it as such in the bleaching process. Investigation has not 
told us if it enters into combination as SO 2 , and, like oxygen, destroys color, altering the 
compound by inserting itself. 



We may fairly conclude that the processes by chlorine and sulphurous acid are per- 
formed in a manner as different as the mode in which a salt of ammonia acts on chlorine or 
an oxacid, or, in Dr. Wilson's general terms, " Specific differences may be expected to 
occur with all the gases named, as to their action on any one coloring matter, and with 
different coloring matters, as to their deportment with any one of the gases." — Traits^ R. 
S. K, 18-18. 

It has been attempted to introduce manganates, chromates, chlorates, chlorochromic 
acid, and sulphites, but without success, as bleaching agents. 

General Process of 'Bleaching. — The process of bleaching, from what we have seen, 
resolves itself into treatment with alkalies and the action of chlorine or of light. In de- 
scribing the operations, they seem to be very numerous ; but, as explained, some require to 
be repeated gently, instead of being finished by one decisive operation, so as not to injure 
the fibre ; and some are intermediate operations, such as the frequent washings needed in 
passing from one process to the other. The alkaline solution in which the goods are boiled 
does not contain above 250 lbs. of carbonate of soda to 600 gallons, but nearly always less. 
Lime is, however, used much more frequently than soda, which it will be seen is only em- 
ployed in the second process, and the third, if there be one. It is less hurtful to the cloth, 
and is much cheaper than the alkalies. 

The chloride of lime is used at J Twaddle, or 1002-5. It is not considered so important 
now as formerly, and where 300 lbs. were formerly employed, 30 to 40 are now used. The 
goods are made nearly white by the alkalies. The chlorine gives only the last finish, and is 
sometimes used to whiten the ground on colored goods. The whole process may be ex- 
pressed thus : — Wash out the soluble matter ; boil with lime to dissolve still more, and to 
make a fatty compound with the oily matter ; wash out the lime by acids ; wash out the fat 
with a soda soap ; clear the white by chloride of lime. 

The impurities in the cloth have a certain power of retaining color upon them. Mud 
and dirt, as well as grease, gluten, and albuminous matters, have this property, and fatty 
soaps, such as lime compounds of fatty acids. The pure fibre, however, has no power of 
taking up solutions of such coloring matter as madder. When, therefore, it is desired to 
try the extent to which cloth has been bleached, it is dyed or boiled up with madder ex- 
actly as in the process of dyeing. It is then treated with soap, as the madder-dyed goods 
are treated, and if it comes out without a stain, or nearly pure white, the goods are ready. 
Dyers or calico-printers who dye printed goods are exceedingly particular as to the bleach- 
ing, the dyeing and printing having now approached to such exactness, that shades invisible 
to any eye not very much experienced are sufficient to diminish in a material degree the 
value of the cloth. Any inequality from irregularity of bleaching, which causes a similar 
irregularity of dyeing, is destructive to the character of the goods. Many patterns, too, 
have white grounds ; these grounds it is the pride of a printer to have as white as snow. 
If delicate colors are to be printed, they will be deteriorated if the ground on which they 
are to be printed is not perfectly white. 

Old Methods still in use. — As a specimen of the older processes, we shall give the fol- 
lowing, adding afterwards a minute account of some of the plans adopted by the most suc- 
cessful bleachers. When grease stains do not exist, as happens with the better kind of 
muslins, or when goods were not required to be finely finished, the following has been 
adopted : — After singeing, 1. Boiling in water. 2. Scouring by the stocks or dash-wheel. 
3. Bucking with lime. 4. The bleaching property so called, viz., passing through chlorine 
or crofting. 5. Bucking or bowking with milk of lime. These two latter processes em- 
ployed alternately several times, till the whole of the coloring matter is removed. 6. Sour- 
ing. 1. Washing. 

The Processes used in Bleaching. Singeing. — The singeing is performed by passing 
the cloth over a red-hot plate of iron or copper. The figure 50 shows this apparatus as 
improved by Mr. Thorn. At a there is a cylinder, with the cloth wound round it to be 
singed ; it passes over the red-hot plate at b, becomes singed, passes over a small roller at 
c, which is partly immersed in water, and by this means has all the sparks extinguished ; 
then is wound on to the roller d, when the process is finished. As the products of combus- 
tion from the singeing are sometimes very unpleasant, they are carried by this apparatus 
into the fire-place, where they are consumed. The arrows show the passage of these vapors 
from the surface of the cloth downwards into the hearth, and thence into the fire. 

For goods to be finely printed both sides are singed ; for market bleaching, one side. 
Sometimes, however, singeing is not at all desired. 

The use of a line of gas jets instead of a red-hot plate, was introduced by Mr. Samuel 
Hall. It has not, however, found its way generally into bleach works : the plate is pre- 
ferred. Gas jets are used necessarily in singeing threads. 

Shearing. — For fine printing, it is by some considered needful to shear the nap of the 
cloth instead of singeing it. The method is more expensive than singeing. Messrs. Mather 
and Piatt have made a machine which will shear GO to SO yards per minute. 
Vol. III.— 10 







Bucking or Bowking. — This is the process of boiling goods. It is performed in alkaline 
liquids, generally lime or soda, or both. The kier for bowking is a cylindrical iron vessel, 
constructed so as to render the boiling free, and prevent the goods from being burnt on the 
bottom. The kier of Messrs. Mather and Piatt is very complete. The first figure (51) is 
the kier when shut or screwed down. The second figure (52) is the section of the tier, 
which is very like that before given ; but in this case it is steam-tight, and heated by steam 
which issues from a steam pipe communicating beneath the false bottom. The dangers 
attending the kier before mentioned are by this means entirely averted, and all the inven- 
tions which give the washing liquid a separate and distinct place for heating are at once 
done away with. 

An exact description of these kiers is required, a, 6, c, d, represent the body of the 
kier, which is a cylindrical vessel, generally made of cast-iron, but sometimes of wood, or 
wrought iron. h represents false bottom — a cast-iron grating sometimes covered with 
boulder-stones, and sometimes with wood ; g, cylindrical disk, of wrought iron, placed on 
the top of " puffer-pipe " q, to spread the liquor over the cloth. §■, " puffer-pipe," standing 
on false bottom, h. s, cylindrical casting for supporting false bottom and "puffer-pipe," 
whose periphery is " slotted," to admit of the liquor passing through, r, cover for kier ; 
the flanch on which this cover rests is grooved a little, to admit of " gasking " being 
inserted, so as to form a " joint." k, k, swivel bolts, holding down the cover, i, a small 
aperture, covered with a lid capable of being removed easily, to enable the attendant to see 
that the cloth does not rise too high in the kier to endanger its working ; if such happens, 
he checks the steam until the cloth settles, after which it does not again attempt to rise. 
n, steam valve ; I, water valve ; both communicate with pipe w, leading to kier. r, pipe 
communicating with kier for supplying steam and water — also serves as escape pipe ; /, es- 
cape valve for letting off kier ; c, wheel for opening ditto ; m, steam pipe from boiler. 
<?, p, foundation for kier. 

The process of cleansing is very various. Some use lime for the first process ; some use 
soda alone ; and some use them mixed. Of course, when carbonate of soda and lime are 
used, caustic soda is at once formed, and the carbonate of lime is left idle. The practices 
and fancies of bleachers are numerous ; and we have only to say that the principle consists 
in the use of alkaline lyes. Some use lime to the amount of 3 per cent. ; others go as high 
as 10. The lime is slaked first and a portion thrown in ; a portion of cloth is laid upon it, 
and a portion of lime again covers that ; but on no account must the goods be allowed to 
lie in contact with the atmosphere and the lime. 

When removed from the kiers the goods must be washed. Now, if they are to be 
washed in dash-wheels, it is needful that they be in separate pieces, and in this state they 
are sometimes boiled in the kiers ; but if they are to be washed in the washing machines, 
they are lifted out of the kier in the same manner as a piece of string is drawn'out of the 
canister in which the coil is kept. 

M. Metz, of Heidelberg, has attempted to perform the work of boiling by merely ex- 
tracting the air from the cloth. For this purpose the cloth is simply put into a strong 
upright cylinder, the top screwed down, and the air taken out by an air-pump. We have 
no knowledge as to the advantages gained by this process, or whether it has been found 
actually capable of putting cloth in a condition to be bleached for a very fastidious market. 



:^.vXVX-,>X vx-YN^";-: 



Steeping. — Instead of boiling in the kier at first, the goods are sometimes, though now 
rarely, steeped from one to two days in water, from 100° to 150° F., for the purpose of 
loosening the gummy, glutinous, and pasty materials attached to the cloth. Fermentation 
ensues and this process is dangerous, as the action of the ferment sometimes extends to the 
"oods, especially if they are piled up in a great heap without being previously washed. The 
spots of urease on the insoluble soaps become thereby capable of resisting the caustic alka- 
lies and are rendered in some measure indelible : an effect due, it is believed, to the acetic 
and carbonic acids generated during fermentation. Some persons throw spent lyes into the 
fermenting vats to counteract the acids. The spots of grease are chiefly to be found in 
hand-loom woods, and the difficulty concerning the fats is not therefore commonly felt where 
power-loom goods are chiefly used, as in Lancashire. 

Washing. — The machine made by Mr. Mather {figs. 53 and 54) washes 800 pieces per 
hour, or 8,000 pieces per day of 10 hours, using 400 gallons per minute, or 120,000 gallons 
per day, or 20 gallons to a piece. This class of machine is now in its turn superseding the 

This washing machine will be understood by the general plan, {fig. 54, and correspond- 
ing section, fig. 53.) a and b represent the squeezing-bowls. a is 18 inches diameter and 
8 feet 3 inches long ; it is made of deal-timber. (The lapping of strong canvas at a" is for 
the purpose of giving the " out-coming" pieces an extra squeeze, in order to prepare them 
for the kiers.) b is 24 inches diameter and of the same length as a, making 100 revolutions 
per minute ; it is generally made of deal, sycamore, however, being better, c, d, a strong 
wooden rail, in which pegs are placed in order to guide the cloth in its spiral form from the 
edge to the centre of the machine. A, h, the water-trough, through which the piece passes 
round the roller r. p, {fig. 53,) water-pipe ; t, water-tap ; to, to, pot-eyes, which may be 
adjusted to any angle, to guide and regulate the tension of the piece on entering the 
machine. I, side frame, for carrying bowls, &c. ; g, engine (with cylinder, 8 inches 
diameter) and gearing for driving machine -, w, weight and lever for regulating pressure on 
the bowL 

This machine washes 800 pieces per hour, and requires 400 gallons of water per minute. 
It will serve also to represent the chemick and souring machine, the only difference being 
that the bowls are 3 feet 6 inches, instead of 8 feet 3 inches, in length. 

The ehemick and sour are brought by turns into the trough, or into similar separate 
troughs, by a leaden pipe from the mixing cisterns, and are run in to 6 or 8 inches deep. 

The washing machine of Mr. Bridson {fig. 55) is worth attention. In its action the 
"course of the cloth in the water is easily seen -, it is chiefly horizontal. This motion had 
been given by Hellewell and Fearn in 1856 ; but they had a very complicated machine, and 
they did not attain the flapping motion which is given to the cloth when it becomes sud- 
denly loose,- and is driven violently against the board a a as often as b c and e d are in one 
line. It is not shown by the drawing that the cloth passes eight times round these wheels. 
There is a constant stream of water from the pipe /, which is flattened at the mouth about 
one and a half inches in one diameter, and about ten inches in the other. This machine can 
wash 900 pieces in an hour. It requires about twice as much water as a dash-wheel, but 
washes seven and a half times more pieces. Its length is nine feet. 




Souring. — After boiling in the first kier and washing, the goods are soured in muriatic 
acid of 1010- specific gravity, or 6-J- gallons of the usual acid, which contains 33 per cent. 
of real acid, mixed with 100 gallons of water. This is equal to 2° Tw. Muriatic acid may 
be replaced by sulphuric acid of 1024 - specific gravity, i..e. 3-J gallons liquid acid to 100 
of water ; — or the amount of the acid may be doubled in either case, and a shorter time 
allowed for the souring. The souring is performed in wooden or stone cisterns, where the ' 
cloth is laid regularly as it falls over one of the rollers of the calender ; — or it is passed 
through the acid solution by the movement of the calender in the same manner as described 
in the process of washing. If this method is used, it is allowed to lie on the stillages from 
two to three hours to allow the acid to act. The acid decomposes any lime soap formed, 
and washes out the lime. Hydrochloric or muriatic acid has been preferred in the process 
described, as the chloride of calcium is so much more soluble than the sulphate. After 
souring, of course the goods must be thoroughly washed as before. 

The sixth operation with soda removes the remaining fatty materials. If lime be used, 
it may be allowed to settle ; and it is better to allow it to do so, and thus to use pure caus- 
tic soda, which will with the resin remove the impurities in a more soluble form. If, instead 
of adding 170 lbs. of soda crystals to 600 gallons of water, 4 '6 lbs. of liquid caustic soda of 
specific gravity 1320 - were added, the effect would be the same. 

The solution of resin and carbonate of soda is a half-formed soap, which is considered to 
act beneficially in moving the soluble matter. It would not appear, from theory, to be 
capable of doing so well as the soda which has its cai'bonic acid removed ; but tender goods 
will not allow the action of caustic soda, and the carbonate is therefore safer. 

Powder-bleaching. — Chloride of lime is added in stone vessels where the goods are 
allowed to lie. It is universally called ehemick in the manufactories. The strength used at 
Briekacre is half a degree Twaddle, or 1002'5. This is sometimes very much increased, so 
as to be even 5° in some establishments, according to the goods bleached ; but it is not safe 
to allow the cloth to lie long in such strong solutions. In such cases it is needful to pass 
them rapidly through with the calender, so as to soak them thoroughly, and then to pass 
them on to the acid, and forward to be washed. It may be remarked that the use of the 
calender for these operations renders it possible to use strong solutions, even for tender 
goods, as there is no time given for injurious action on the fibre. 

Great care is to be taken to make the solution of the chloride of lime perfectly clear. 
The powder does not readily wet with water, and it must therefore be pressed or agitated. 
This may be done by putting it in a revolving barrel with water, until complete saturation 
of the powder with moisture ; the amount required is then thrown into the cisterns, and the 
insoluble matter allowed to sink. This insoluble matter must not be a41owed to come into 
contact with the cloth, as it will be equal of course to a concentrated solution of the liquor, 
and will produce rottenness, or bum the cloth so as to leave holes. When removing from 
the trough, the cloth is drawn through squeezing rollers, which press out any excess of 
chloride of lime. 

Squeezing. — A squeezing machine, with a small engine attached, is shown vafig. 56, for 
the drawing of which we are again indebted to the makers, Messrs. Mather and Piatt. 

d, f represent the squeezing bowls. They are as large in diameter as possible, and are 
generally made of sycamore ; but the bottom one is better made of highly compressed cot- 
ton, a, b are the engine and frame for driving ; g, frame for carrying bowls ; I, I, com- 
pound levers for regulating the press use ; s is a screw for the same purpose,, and e is the 
cloth passing through the bowls. 

The white-squeezers, or those used before drying, should have a box, supplied with hot 
water, fixed so that the piece may pass through it before going to the nip of the bowL 

When the goods are run through, they are carried off upon a grated wheelbarrow in a 
nearly dry state, and transferred to the spreading machine called at Manchester a candrog. 
In many bleach-works, however, the creased pieces are pulled straight by the hands of 
women, and are then strongly beat against a wooden stock to smooth out the edges. This 
being done, a number of pieces are stitched endwise together, preparatory to being mangled. 

This squeezing machine is small, but, as will be seen, the rollers are introduced so as to 
act as long and as rapidly as cloth of whatever length is drawn through them. 

The following figure (57) represents a pair of squeezers, for squeezing the cloth after 
several of the processes named, and are shown as being driven by a small high-pressure 
engine, a is the fly-wheel of engine ; 6, crank of ditto ; c, frame of engine ; d, spur-wheels 
connecting the engine and squeezers ; e andy, sycamore squeezing bowls. 

The cloth when passed over the steamed rollers is now dry ; but it is not smooth and 
ready for the market. If the cloth is wanted for printing, no further operation is needed ; 
but if to be sold as white calico, it is finished by being starched and calendered. 

The starch at large works is prepared by the bleachers themselves. At Messrs. Bridson's 
it is made with the very greatest care from flour. Of course it would be more expensive 
for them to buy it; as the manufacturer would dry it, and they would require to dissolve it. 
They are able also, in this, manner, to obtain the purest starch. This is mixed with blue, 






according to the finish of the goods. A roller, which dips into the starch, lays it regularly 
and evenly on the cloth in the same manner as mordants are communicated in calico-print- 
ing, whilst other rollers expel the excess of the starch. The cloth is then dried over warm 
cylinders, or by passing into a heated apartment. It receives the final finish generally by 
the calender ; but muslins receive a peculiar treatment. See Calender, vol. i. 

Finishing. — Pure starch is not always used for the purpose of finishing. Fine clay, 
gypsum, or Spanish white, is mixed with the cloth ; and if weight is desired to be given, 
sulphate of baryta is employed. Mr. John Leigh, of Manchester, has lately patented for 
this purpose the use of silicate of soda, which, for such goods as are not injured by alkalies, 
seems to answer the purpose at a very cheap rate. There can, however, be no doubt that 
too much attention is given to this finish for home goods, or for all purposes which require 
the goods to be washed ; they assume a solidity of appearance which they do not possess 
when the finishing material is removed from the pores, and the cloth appears without dis- 
guise. In some instances, however, this finish is a peculiarity of the goods, and is almost as 
important as the cloth itself. For example : in the case of muslins, when they are dried 
at perfect rest, they have a rigid inelastic feeling, somewhat allied to that of thin laths of 
wood, and feel very rough to the touch. They are therefore dried by stretching the cloth, 
and moving the lines of selvage backward and forward, so as to cause the threads of weft to 
rub against each other, and so as to prevent them becoming united as one piece. Goods 
dried in this manner have a peculiar spring, and such thick muslins are for a time possessed 
of great elasticity. Several pieces folded up in a parcel spring up from pressure like 

Mr. Ridgeway Bridson invented an apparatus for giving this peculiar finish to muslins. 
Formerly it was done entirely by the hand, and in Scotland only. Since the invention of 
this machine, this trade has become a very important one in the Manchester district. 

Sometimes goods are finished by the beetle, which acts by repeated hammering. This 
peculiar action has been transferred to a roller by T. R. Bridson, and called the " Rotatory 
Beetle." It consists of a cylinder having alternately raised and depressed surfaces, and two 
other cylinders which press upon it, and alternately press the cloth and give a freedom as it 
passes between the rollers. This is similar to the rise and fall of the hammers or mallets 
in the beetling process. 

Sometimes a stiff finish is wanted ; then muslins are dried in the usual way. 

Drying. — Figs. 58 and 59 represent a drying machine, with eleven cylinders, each 22 
inches in diameter, capable of drying 1,000 pieces of bleached calico in a day. a represents 
cylinders heated with steam ; v, vacuum-valves in ditto ; /, frame for carrying cylinders ; 
e, folding apparatus ; s, steam-pipe ; r/, gearing. 

"When goods are dried having a raised pattern, such as brocades, or any other, such as 
striped white shirting, only one side of the cloth is to be exposed ; the pattern rises up from 
the heated surface on which the cloth is dried. For this reason, cylinders such as those just 
described cannot be used. Large wheels of cast-iron are employed, consisting of two con- 
centric cylinders, between which is a closed space heated by steam. The cloth is by this 
means heated on one side only, not passing from cylinder to cylinder, in which case the side 
next to the heating surface would be changed every time. The larger the cylinder or 
wheel, the more rapid is the drying, as there is more surface of cloth exposed to it at a 
time • it can, for the same reason, be turned more rapidly round. Well-finished goods will 
not rise when heated, except on the pattern. Messrs. Bridson have a large business in 
jacconets for artificial flowers on account of this peculiar finish. They are formed ot a 
plain cotton cloth, but stand the pressure of hot irons without curling. 



No essential difference is made in bleaching muslins, except tbat sometimes weaker 
solutions are employed for very tender goods. Mr. Barlow makes no difference as a rule in 
the strength given in describing his process ; with very strong goods, he sometimes uses 
the liquids stronger. 

It is desired occasionally to bleach goods which have colored threads woven into them, 
or colors printed on them. In these cases great caution must be used. It is needful to use 
weak solutions, but more especially not to allow any one process to be continued very long, 
but rather to repeat it often than to lengthen it. This may be stated as a general rule in 
the bleaching of goods. It would indeed be possible to do the whole bleaching in one 
operation, but the cloth would be rotten. This arises from the fact that, at a certain 
strength, bleaching liquid or soda is able to destroy the fibre ; but another and less strength 
does not act on the fibre, but only on such substances as coloring matters. This care is 
needed when printed goods which have a white ground are treated. The white ground 
takes up color enough to destroy its brillianc} 7 , and soaping does not always remove it. The 
bleaching then is effected by using bleaching liquor at -£ Twad. Some persons put a Turkey 
red thread into the ends of the pieces. The original use of this seems to be scarcely known 
among the manufacturers. It was used as a test of the mode of bleaching employed. If 
strong solutions be used, which are apt to spoil the cloth, the color of the dyed threads will 
be discharged. When the separate system is employed, this is evaded easily ; it is the 
practice to keep the ends containing the red threads out of the liquid, allowing them to rest 
on the side of the vessel. 

Sometimes chlorate of potash is used for the same purpose, souring as with the bleaching 
powder. The colors may, in this manner, be made much more brilliant than before, 
although a little excess will discharge them.' A good deal of the effect may be owing to the 
better white given to the ground. Besides these processes for bleaching, another was at 
one time introduced, which consisted of immersing the cloth in a solution of caustic alkali, 
and afterwards steaming in a close vessel. It is not now in use. Alkali of 1020' specific 
gravity was used. 

The new or continuous Process. — This method owes its introduction to David Bentley, 
of Pendleton, who patented it in 1828. It consists in drawing the goods in one continuous 
line through every solution with which it is desired to saturate them. This is done by con- 
necting the ends of all the pieces. The motion of rollers draws the chain of cloth thus 
formed in any desired direction, and through any number of solutions any given number of 
times. We shall allow him to use his own words : 

Fig. 60 is an end view of two such calenders, each having two larger rollers b and b 1, 
a smaller driving roller c, two racks d and d 1, placed upon two cisterns g and g 1, inside 
of which cisterns are two rollers e and e i, which rollers have four square ribs upon each, 
to shake the goods as they pass through the cisterns. At f is a frame upon which the 
batches of goods are placed upon rollers shown in Jig. 61, where they are marked k, k, k, k. 
The calender cheeks are made fast at the feet, at the middle, and to the top of the building, 
having levers and weights h to give pressure to the calender bowls. 

Near the end walls of the building are two rollers, one of which is shown at a ; upon 
each of these is a soft cord used as a guide for conducting the goods through the machinery 
and cisterns. The operation is commenced by passing one end of the cord through the 
rollers b and c, down to cistern g, under roller e, through the furthermost division of rack 
d, and again through calender rollers at b and c, repeating the same, but observing to keep 







i" K idbxi'jB 



the cord tight, and to approach one division nearer in 
rack d each revolution until each division is occupied, 
when the end must pass over c, under and around b 1, 
down to and over the guide roller i 3, through the nearest 
division of rack d 1 into cistern g 1, under roller e i, over 
guide roller i 2, and again over roller c, under and round 
b 1. This course must be repeated, observing as before to 
keep the cord tight, and to receive one division of rack 
d 1 every revolution, until each division of rack d 1 is 
occupied, when the end must pass over from b 1 under 
I 4. The cord now forms a sort of spiral worm round 
and through the machinery and cisterns, beginning at b, c, 
and ending at the top of b 1 to i 4, the number of revo- 
lutions being governed by the number of divisions in the 
racks d and d 1, so that if there were fifteen divisions 
in each rack, there would be fifteen revolutions under c, 
round b through g, under e through d, and fifteen revo- 
lutions over c round b 1, over I 3 through d 1 and g 1, un- 
der e 1 over i 2, and again over c, passing from the top of 
b 1 to i 4 ; and by this means, if one end of the back of goods marked k, and placed upon 
the frame r., (jig. 61,) is fastened to the end of the guide cord, the goods will, when the 
calender is put in motion, be conducted and washed thirty times through the water in the 
cisterns, and squeezed thirty times through the calenders. As the operation proceeds and 
the guide cord passes through the calender, it is wound by hand upon roller a to prevent it 
from becoming entangled, and to keep it in readiness for the next operation. As soon as 
the first end of the goods has passed through jig. 61, and arrives at the guide roller I 4, it 
is detached from the end of the guide cord and attached to the guide cord to the other end, 
or with the opposite set of calenders. After this, by putting these in motion, the goods are 
washed and squeezed through its cisterns, which cisterns are supplied with hot and strong 
lime lye, and the goods passing over guide roller i 9, they are conveyed over other guide 
rollers to be placed for the purpose, and taken down by some person or some proper 
machinery into one of the boiling vessels, where, steam or fire heat being added, they are 
suffered to remain while the lime-boiling takes effect. 

We need not follow the inventor into all the particulars. When the goods were suffi- 
ciently acted on by one solution, another solution was used, so that this mode of calender- 
ing not only was a method of moving the goods from place to place by means of rollers, 
but it was a method also of saturating goods thoroughly with a solution, and of washing 

It was by a similar method that Mr. Bentley bleached skeins of yarn, of linen, or of cot- 
ton. The skeins are looped together by tying any soft material round the middle of the 
first skein, which will leave the loops from one end of the next skein to pass half-way 
through, and which will always leave other two loops, and by repeating which any quantity 
of skeins may be looped together, tying the last loop with another soft material. 

The mode of saturating the goods with solutions is effected by the arrangement shown 
in jig. 62. Kapid motion and- frequent pressure are introduced instead of a still soaking 






EZEgJSlS ^ g5ig3gZi5agSE35i 




\ iiiMiii n i l ipi iiii |i i tK|i ii.iiii iiii i!! i-|||W) 




A is a roller for the guide cords ; b, b, b, are eleven washing rollers ; c, c, c, are speed 
rollers ; e, e, e, are twelve rollers immersed in twelve divisions of the cistern g. The 
eleven staple-formed irons which pass through the frame rails on each side of the centres of 
the eleven rollers b, b, b, and the eleven rollers c, c, C, serve to stay these rollers in their 
places, at the same time allowing the eleven washing rollers b, b, b, to rise and fall accord- 
ing to the pressure by which they are held down, by the eleven weights attached to these 
irons at h, and upon the bottom rail may be placed such staves, brushes, or rollers, as may 
be found necessary for holding and brushing the goods in the best manner to keep them 
straight during the different washings in water and bleaching liquors. The goods are pre- 
pared by steeping, as before described, and placed in batches at f, and passing under the 
immersing rollers e and the twelve divisions of cistern g, between the eleven speed rollers 
c and the eleven washing rollers b, as seen at k, are taken down straight and open into one 
of the vessels, and are then boiled by steam, which is succeeded by repeated washings alter- 
nately in water and bleaching liquors, until they are sufficiently bleached, as before de- 

The elevation and ground plan of a bleach-house and machinery capable of bleaching 
800 pieces of 4 lbs. cloth per day, (for best madder work,) with the labor of one man and 
three boys, working from 6 until 4 o'clock, exclusive of singeing and drying, are represented 
in Jigs. 63 and 64, (p. 156.) The letter d represents two lengths of cloth of 400 pieces each, 
(end of pieces being stitched together by patent sewing machine made by Mather and Piatt,) 
making together 800 pieces, passing through washing machine g, and from thence delivered 
over winch, w, into kier, c, — this operation occupies one hour, — where they are boiled for 
twelve hours in lime. They are then withdrawn by the same washing machine, g, washed, 
and passed into second kier, b, (operation occupying one hour,) where they are boiled for 
twelve hours in ashes and resin ; again withdrawn by the same machine, g, washed, 
squeezed, (see plan at u,) and passed over winch e, and piled at h, (this operation occupies 
one hour.) They are then taken from pile, h, and threaded through sour-machine, e, 
soured, passed over winch, e", and piled at k, (operation, one hour,) where it remains in the 
pile for three hours. It is then squeezed at u, and washed through machine, g, (an hour's 
operation,) delivered into third kier, a, boiled for six hours, washed at g, squeezed at u, (an 
hour's operation,) and passed through chemick machine, (an hour's operation,) and piled for 
one hour ; after which it is soured again, (an hour's operation,) squeezed, and washed at g, 
(an hour's operation,) squeezed again at/, (an hour's operation,) and dried by machine at p, 
(Jig. 63.) 

There are several advantages in using the squeezing process so often in the above 
arrangement : — Firstly, The bowls of the washing machine are not so much damaged by the 
heavy pressure which is required to be applied, if no squeezers are used, in order to prepare 
the pieces for the sour and chemick machines : Secondly, A drier state of the cloth than can 
possibly be produced by the washing machine alone, thus fitting it to become better satu- 
rated with the chemick or sour : Thirdly, The piece passing from the souring to the washing 
machine, in this arrangement, carries with it less of the acid, and thus ensures a better 
washing with less water. 

It may be observed, that the velocity of the above-mentioned machines is much higher 
than usual, experience having shown that the various operations are thus better performed 







1 i 







than when running slower. The reason of this appears to be, firstly, that the piece, running 
at such velocity, carries with it, by reason of capillary attraction, a greater quantity of liquid 
to the nip of the bowls ; secondly, the great velocity of the bowls, together with the greater 
quantity of water carried up, produces a more powerful current at the nip and down the 
ascending piece, thus penetrating to every fibre of it. 

It may also be remarked, that the above-mentioned machines are not adapted to the 
bleaching" of linen ; for the latter cloth, not having the same elasticity as cotton, if it should 
become tight, would either be pulled narrow or torn. 

In illustration of the continuous process as at present used, the plan of proceeding at 
Messrs. McNaughten, Barton, and Thorn's, at Chorley, may be described : 

1. In order that there may be no interruption in the process, the pieces are united in 
one continuous piece — each piece being about 30 yards, the whole varying with the weight 
of cloth — about 300 yards long. Each piece is marked with the name of the printer. This 
is sometimes done in marking ink of silver, and sometimes in coal tar, at the extremity of 
the piece. The pieces are rapidly tacked together by girls, who use in some establishments 
a very simple sewing machine. (See Sewing Machine.) The whole amount to be bleached 
at a time is united in one piece, and is drawn from place to place like a rope. To give 
them this rope form, the goods are drawn through an aperture whose surface is exceedingly 
smooth, being generally of glass or earthenware. Of these many are used in transferring 
the cloth from place to place. They serve instead of pulleys. The cloth when laid in a 
vessel is not thrown in at random, but laid down in a carefully made coil. The rope form 
enables the water to penetrate it more easily. 

2. The pieces are singed. 

' 3. They are boiled in the first kier. In this, 3,500 lbs. of cloth have added to them 
250 lbs. of caustic lime, 1 lb. of lime to 14 of cloth. The kier is cylindrical, 7 feet deep 
and 8 feet, in diameter ; as much water is added as will cover the cloth, about 500 gallons. 
This boiling lasts thirteen hours. t 

4. They are washed in the washing machine. Robinson and Young's machine is 

5. Thev are soured in a similar machine with hydrochloric acid of specific gravity 1010", 
or 2° of Twaddle. 

6. The same amount of cloth being supposed to be used, it is bucked in a solution of 
soda-ash and resin, 170 lbs. of soda-ash to 30 lbs. of resin. . The boiling lasts sixteen hours, 
the same amount of water being used. 

7. Washed as before. 

8. Passed through chloride of lime, or chemicked. The cloth is laid in a stone or 
wooden cistern, and a solution of bleaching powder is passed through it, by being poured- 
over it and allowed to run into a vessel below ; this is managed by continued pumping. 
This solution is about half a degree Twaddle, or specific gravity 1002'5. The cloth lies in 
it from one to two hours. 

9. Washed. 

10. Boiled again in a kier for five hours with 100 lbs. of carbonate of soda crystals. 

11. Washed. 

12. Put in chloride of lime as before. 

13. Soured, in hydrochloric acid of 1012-5 specific gravity, or 2\° Twaddle. 

14. Lies six hours on stillages. — A stillage is a kind of low stool used to protect the 
cloth from the floor. 

15. Washed till clean. 

16. Squeezed in rollers. 

17. Dried orver tin cylinders heated by steam. 

This is the process for calico generally ; some light goods must be more carefully handled. 
The usual time occupied by all these processes is five days. Theysare sometimes dried 
in a hydro-extractor ; after singeing, laid twenty-four hours to steep, theu washed before 
being put into the lime kier. 

High-pressure Steam Kier. — This is designed still further to hasten the process of 
bleaching, and at the same time to improve it. 

Fig. 65 is an elevation showing the arrangement of these kiers, (which are recommended 
to be made of strong boiler-plate iron.) One of these is shown in section, a and 6 are the 
kiers ; c is a perforated platform, on which the goods to be bowked are laid ; k k is the pipe 
connecting the bottom of the kier b with the top of the adjoining kier, a ; and I, I, the 
corresponding pipe connecting the opposite ends of the kiers a and b ; m m are draw-off 
cocks, connected with the pipes k and I, by which the kiers can be emptied of spent liquor, 
water, &c. ; n and o are ordinary two-way taps, by which the steam is admitted into the 
respective kiers from the main pipe, p, and the reversing of which shuts off' the steam com- 
munication, and admits the bowking liquor as it becomes expelled from the adjoining kier ; 
q is a blowing-off valve or tap ; r, the pipe through which the bowking liquor enters into 
the kier ; s, manhole, (closed by two cross bars, secured by bolts and nuts,) through which 




the goods are introduced and removed ; 1 1 are gauges, by which it is ascertained when the 
liquor has passed from one kier and has entered the other. 

The process adopted for bleaching is as follows ; it is the shortest and simplest in use : 

1. The box or water trough of the washing machine is then half filled with milk of lime 
of considerable consistence, and the goods are run through it, being carried forward by the 
winches and deposited in the kiers. The whole of the cloth in a kier is in one length, and 
a boy enters the vessel to lay it in regular folds until the kier is filled. All the cloth before 
entering the kier must pass through the lime. 

2. When the kiers are filled, a grid of movable bars is laid on the top of the cloth, and 
the manhole of the kiers is closed. High-pressure steam is then admitted at the top ; this 
presses down the goods and removes the lime water, which is drawn off at the bottom. At 
the same time the air is also removed from the goods and replaced by steam. When this is 
driven off, and nothing but steam issues from the tap at the bottom, 40 lbs. of lime, which 
have been previously mixed with 600 gallons of water, are introduced into the first kier in 
a boiling state. High-pressure steam is again admitted, which forces the lime liquor 
through the goods to the bottom of the vessel, then up the tube I, and on to the goods in 
the second kier. The tap is then closed which admits steam into the first kier, and the 
steam is now sent into the second. The same process occurs, only in this case the liquid is 
sent again on to the top of the goods in the first kier. This process is continued about 
eight hours. 

In this method each *7,000 lbs. of cloth take into the kiers 2 cwts. of lime, which is 
equally distributed. The clear lime-water which is blown out of the steam at the com- 
mencement contains only 3 to 4 lbs. of lime in solution. At the close of the operation the 
liquor has a specific gravity of 3| to 4° Twaddle, (1017-5 to 1020,) instead of half that 
amount, or 1J to 2° Twad., (lOO^ to 1010,) as is usual. 

3. When the liming is completed the steam pressure in the kiers is removed, the man- 
way opened, the grid lying above the cloth removed, and the cloth in the kier attached to 
the washing machine, which draws the goods out of the kiers and washes them. 

4. The pieces are then passed by the winches through the souring machine, or soured 



by having muriatic acid of 2° Twaddle pumped upon them, (1010.) They must remain 
with the acid two or three hours, either steeped in it, or after having passed through it. 

5. Again attach the cloth to the washing machine, and wash it well, passing it on by 
winches, as before, into the kier. 

6. Introduce steam and drive off the air and the cold water ; these are let out by the 
tap at the bottom: add then 224 lbs. of soda-ash and 150 lbs. of resin, boiled in 600 
gallons of water, for 7,000 lbs. of cloth. Work the kiers by driving the liquid from one to 
the other as before ; about eight hours is a sufficient time. These proportions of soda may 
be varied. If the cloth is very strong, a little more may be used, (or if the cloth has been 
printed upon in the gray state, from having been used to cover the blanket of the calico- 
printing machine.) 

7. After this the cloth is passed through the washing machine, and then submitted to 
chloride of lime. This may be done either by the machine or by pumping. In either case 
it is an advantage to warm the bleaching liquid up to 80° or 90° F. The strength of the 
solution when the machine is used may be about 4-° Twaddle, or 1002-5 specific gravity ; 
but if the pump is used it must be much weaker. "When the bleaching is for finishing 
white, milk of lime is added to the chloride, in order to retard the operation ; the goods 
are also washed from the bleaching liquor before souring them. This causes a similar 
escape of chlorine, and is a more careful method ; it tends to preserve the headings, or the 
colored threads, which are often put into the ends of pieces of cloth in order to see if the 
bleaching has been performed roughly or not. The original use of this has almost been 
forgotten, but these headings are still carefully preserved. This method preserves also the 
cloth, which is also less apt to be attacked by the chlorine. 

If the cloth has been well managed, it will be almost white when it leaves the second 
kier containing the resinate of soda ; it will therefore require very little decolorizing. If 
the goods have been printed on, more chloride will be needed. The cloth should lie from 
two to eight hours in the liquor, or after saturation with it. The action is quickened if 
warmth is used. They are soured then, as before, in muriatic and sulphuric acid, at 2° 
Tw., for three or four hours ; then wash for drying. 

This method of Mr. Barlow's is an undoubted shortening of the process of bleaching ; 
eight hours only of bucking are found to be enough, and the whole may be performed, by 
the help of the continuous system, in two days. It will be seen that the steam drives the 
solution through the cloth ; and this is equal to the process of stirring, which is a continual 
change of surface and of liquid, but it is more effectual than any stirring could possibly be. 
The goods are laid in a firm, compact mass, and held down by an iron grid, so that the 
liquid cannot run through ruts and crevices, but must run through the cloth itself. 

From what has been said, it -will be seen that the operations of the bleacher are not so 
numerous as at first sight appears, when we call every washing a separate process ; and 
although it really is so, it is managed so rapidly that it can scarcely be said to occupy time, 
and as it is carried on at the same time as the other processes, it scarcely can be said to give 
trouble. The work may be divided into : — 

1. Singeing. 

2. Bowking with lime. 

3. Washing, souring, and washing. 

4. Bowking with resinate of soda. 

5. Washing and chlorinating. 

6. Souring, washing, and drying. 

This process has been tried with success on linen, although not yet in active operation. 

Bleaching op Linen. 
Old Method. — What is called the old method, or that used from about the introduction 
of bleaching powder, at the beginning of the century, till within ten or fifteen years, re- 
quired bleaching on the grass ; and the mode in which it was managed in Ireland and Scot- 
land, where it held its ground longest, is as follows : — 

1. They were rot-steeped in a weak solution of potash, at about 130° F., for two days, 
until the dressing used in manufacturing the cloth was removed. 

2. Washed. 

, 3. Boiled or bowked in potash lye, at |° Twaddle, for ten hours. 

4. Washed, and the ends turned so that the whole might be equally exposed to the lye. 

5. Boiled or bowked in a similar lye to the above for twelve hours. 

6. Washed well. 

7. Exposed on the grass for thijee days, and watered. 

8. Taken up and soured with sulphuric acid, at 2° Tw., for four hours. 

9. Taken up and washed well. 

10. Boiled again for eight hours in potash lye, at 1° Tw., to which had been added black 
or soft soap, about 20 lbs. to a kier of about 300 gallons 

11. Washed. 


12. Crofted, or exposed on the grass, as before. 

13. Treated with chloride of lime at 1-J-" TV., for four hours. 

14. Washed. 

15. Soured iu sulphuric acid, at 2° Tw., for four hours. 

16. Washed. 

17. Boiled for six or seven hours with soap and lye, using in this case more soap and 
one-third less lye than in the former bowkings. 

18. Drawn out and put through rub-boards. This is a kind of washing machine, made 
of blocks of wood, with hard-wood teeth. The goods are washed by it in a soapy liquid. 
The teeth, moving rapidly, drive the soap into the cloth. 

19. Boiled in the lye alone for six hours. 

20. Washed. 

21. Crofted, keeping them very clean, as this is the last exposure. 

22. Treated with chloride of lime. 

23. They are then starched, blued, and beetled, to finish them for the market. These 
operations last six weeks. 

New System, as practised in Scotland and Ireland. — Directions given by an extensile 


1. Wash. 

2. Boil in lime-water ten or twelve hours. 

3. Sour in muriatic acid, of 2° Tw., for three, four, or five hours. 

4. Wash well. 

5. Boil with resin and soda-ash twelve hours. 

6. Turn the goods, so that those at the top shall be at the botom, and boil again as at 
No. 5. 

7. Wash well. 

8. Chemick, at \" Tw., or 1002-5, four hours. 

9. Sour, at 2° Tw., or 1010' specific gravity. 

10. Wash. 

11. Boil in soda-ash ten hours. 

12. Chemick again. 

13. Wash and dry. 

This is the system chiefly adopted when the goods are to be printed. 
The following is the system practised in the neighborhood of Perth, where the chief 
trade is in plain sheetings : — 

1. Before putting them into operation, they are put up into parcels of about 35 cwts. 

2. They are then steeped in lye for twenty-four hours. 

3. Then washed and spread on the grass for about two days. 

4. Boiled in lime-water. 

5. Turned, and boiled again in lime-water, those at the top being put at the bottom. 
60 lbs. of lime are used at a time, and about 600 gallons of water. 

6. Washed, then soured in sulphuric acid of 2° Tw., or 1010 - sp. gr., for four hours, 
then washed again. 

7. Boiled with soda-ash for ten hours ; 110 lbs. used. 

8. Washed and spread out on the green, or crofted. 

9. Boiled again in soda as before. 

10. Crofted for three days. 

11. They are then examined : the white ones are taken out ; those that are not finished 
are boiled and crofted again. 

12. Next, they are scalded in water containing 80 lbs of soda-ash, and washed. 

13. The chloride of lime is then used at -J- Tw., or 1002-5 specific gravity. 

14. Washed and scalded. 

15. Washed and treated with chloride of lime. 

16. Soured, for four hours, with sulphuric acid, at 2° Tw., or 1010 - specific gravity. 

17. Washed. 

If cloths lighter than sheetings are used, the washing liquids are used weaker. The 
great point is to observe them carefully during the process, in order to see what treatment 
will suit them best. 

It will be seen that the process of bleaching linen is still very tedious ; and although it 
may be managed in a fortnight, it is seldom that this occurs regularly for a great length of 
time. The action of the light introduces at once an uncertain element, as this varies so 
much in our climate. If, again, linen be long exposed to the air in a moist condition, it is 
apt to become injured in strength. To shorten the process, therefore, is important ; and 
if no injurious agents are introduced, a shortening promises also to give increased strength 
to the fibre. It has not been found possible to introduce chlorine into linen bleaching at an 
early stage, as in the case of cotton ; and the processes for purifying it without any chlorine 
render it so white that unskilled persons would call it as white as snow. The chlorine is 


introduced nearly at the end of the operation, after a series of boilings with alkalies, sour- 
ings, and exposures on the grass. If introduced at an earlier stage, the color of the raw 
cloth becomes fixed, and cannot be removed. The technical term for this condition is 
" set." Mr. F. M. Jennings, of Cork, has just patented a method which promises to obviate 
the difficulty. The peculiarity consists in using the alkali and the chloride of alkali at the 
same moment, thus giving the alkali opportunity to seize on the coloring matter as soon as 
the chloride has acted, and thereby preventing the formation of an insoluble compound. 
He prefers the chlorides of potash or soda. His plan is as follows : — 

1. He soaks the linen in water for about twelve hours, or boils it in lime or alkali, or 
alkali with lime, and then soaks it in acid, as he uses soaps of resin in other mixtures — the 
alkalies being from 3° to 5° Tw., 1015-1025' specific gravity. 

2. Boils in a similar alkaline solution. 

3. Washes. 

4. Puts it into a solution of soda, of 5° Tw., 1025 - specific gravity, adding chloride of 
soda until it rises up to from 6°-'7 Tw. It is allowed to remain in this solution for some 
hours, and it is better if subjected to heating or squeezing between rollers, as in the wash- 
ing machine. 

5. He then'soaks, sours, and washes. 

6. He then puts it a second time into the solution of alkali and chloride. 

7. Then washes, and boils again with soda. These operations, 6 and 7, may be repeated 
until the cloth becomes almost white. 

The amount of exposure on the grass by this process is said to be not more than from 
one-half to one-fourth that required by the usual method, or it may be managed so as en- 
tirely to supersede crofting. 

Chevalier Clausen has opened up the filaments of flax by the evolution of gas from a 
carbonate in which the plant is steeped, and at the same time bleached by chloride of mag- 

Bleaching of Materials for Paper. 

The bleaching of paper is conducted on the same principle as the bleaching of cotton. 
Paper is made principally of two materials, cotton and flax, generally mixed. The cotton 
waste of the mills, which is that inferior portion which has become too impure for spinning, 
or otherwise deteriorated, and cotton rags, are the principal, if not the only, sources of the 
cotton used by paper-makers. The waste is sorted by hand, the hard and soft being sepa- 
rated, and all accidental mixtures which occur in it are removed. This is done at first 
roughly on a large lattice, which is a frame of wire cloth, having squares of about three- 
quarters of an inch through which impurities may fall. It is then put into a duster, which 
is a long rectangular box, it may be ten feet long, lying horizontally, the inside diameter 
about two feet, and covered with wire gratings running horizontally, leaving openings of 
half an inch in width. As this revolves, the waste is thrown from one angle to the other, 
and throws out whatever dust or other material falls into the holes or spaces. The fibrous 
matter has little tendency to separate from the mass, which is somewhat agglutinated by 
being damp, chiefly from the oil obtained during the processes in the cotton mill. A second 
duster, however, is used to retain whatever may be of value ; it is a kind of riddle. It is 
then transferred to the lattices, which are a series of boxes covered with wire gauze, the 
meshes of which are about half an inch square, and so arranged as to form a series of sort- 
ing tables. The sorting generally is done by young women. Each table has a large box or 
basket beside it, into which the sorted material is thrown ; this is removed when filled, by 
being pushed along a railroad or tramway. Pieces of stone, clay, leather, wood, nails, and 
other articles, are taken out. The cotton is then put into a devil similar to that which is 
used in cotton machinery, but having larger, stronger teeth, which tear it up into small 

The rags are sorted according to quality, woollen carefully removed, and all the unavail- 
able material sent back to the buyer. They are then chopped up by a knife, on the circum- 
ference of a heavy wheel, into pieces of an inch wide, devilled, and dusted. 

The rags and the cotton waste are bleached in a similar manner. The cotton is put into 
kiers of about ten feet in diameter, of a kind similar to those described, and boiled with 
lime. The amount of lime used is about 6 lbs. to a cwt. of cotton or rags, but this varies 
according to the impurity. The lime removes a great amount of impure organic matter, 
and, as in bleaching, cotton cloth lays hold of the fatty matter, of which there is a great 
deal in the waste. When taken out, it is allowed to lie from two to three hours. The ap- 
pearance is not much altered ; it appears as impure as ever. 

_ It is then put into the rag-engine and washed clean. This is a combined washing ma- 
chine and filter, the invention of Mr. Wrigley, near Bury. The washing may last an hour 
and a half, or more. 

The cotton has now a bright gray color, and looks moderately clean. It is full of water, 
which is removed by a hydraulic press, the cotton being put into an iron cylindrical box with 
perforated sides. It is then boiled in kiers or puffing boilers, where soda-ash is used, at the 
Vol. III.— 11 



rate of 4 to 5 lbs. a cwt. Only as much water is used as will moisten the goods thoroughly. 
Much water would weaken the solution and render more soda necessary. It is then washed 
again in the rag-engine ; afterwards put into chloride of lime, acidified as in cotton bleach- 
ing, and washed again in the rag-engine. 

The cotton rags are treated in a similar manner. The colored rags are treated sepa- 
rately, requiring a different treatment according to the amount of color ; this consists chiefly 
in a greater use of chloride of lime. 

Some points relating to bleaching are necessarily treated of under Calico Printing. 

BLEAK. (Cyprinus Alburnus.) The scales of this fish are used for making the 
essence of pearl, or essence d'orient, with which artificial pearls are manufactured. In the 
scales of the fish the optical effect is produced in the same manner as in the real pearl, the 
grooves of the latter being represented by the inequalities formed by the margins of the 
concentric lamina? of which the scales are composed. These fish are caught in the Seine, 
the Loire, the Saone, the Rhine, and several other rivers. They are about four inches in 
length, and are sold very cheap after the scales are washed off. It is said that 4,000 fish 
are necessary for the production of a pound of scales, for which the fishermen of the Cha- 
lonnois get from 18 to 25 livres. 

The pearl essence is obtained merely by well washing the scales which have been scraped 
from the fish in water, so as to free them from the blood and mucilaginous matter of the 

BLENDE (sulphide or sulphuret of zinc, " Black Jack ") is a common ore of zinc, com- 
posed of zinc 67, sulphur 33 ; but it usually contains a certain proportion of the sulphide 
of iron, which imparts to it a dark color, whence the name of " Black Jack," applied to it 
by the Cornish miner. The ore of this country generally consists of zinc 61*5, iron 4-0, 
sulphur 33-0. Blende occurs either in a botryoidal form or in crystals, (often of very com- 
plex forms,) belonging to the tetrahedal division of the monometric system. H = 3 - 5 to 4. 
Specific gravity = 3-9 to 4.— H. W. B. 

■ In some districts the presence of the sulphide of zinc is regarded by the miners as a 
favorable indication, hence we have the phrase, "Black Jack rides a good horse." In other 
localities it is thought to be equally unfavorable, and the miners say, "Black Jack cuts out 
the ore." For many years the English zinc ores were of little value, the immense quantity 
of zinc manufactured by the Vieille Montagne Company, and sent into this country, being 
quite sufficient to meet the demand. Beyond this, there was some difficulty in obtaining 
zinc which would roll into sheets, from the English sulphides. Although this has been to 
some extent overcome, most of the zinc obtained from blende is used in the manufacture 
of brass. 

Dana has given the following analyses of varieties of blende : — 





Carinthia ... 
New Hampshire 
New Jersey - - - 
Tuscany - 

32- 6 

67 -46 






BLIND COAL, a name given to Anthracite. 

BLOCK TIN. Metallic tin cast into a block, the weight of which is now about 3£ 
cwts. Formerly, when it was the custom to carry the blocks of tin on the backs of. mules, 
the block was regulated by what was then considered to be a load for the mule, at 2J cwts. 
Subsequently, the block of tin was increased in size, and made as much as two men could 
lift, or 3 cwts. It was the custom to order so many blocks of tin, and the smelter, being 
desirous of selling as much tin as possible, continued to increase the size of the block, so 
that, although 3| cwts. is the usual weight, many blocks are sold weighing 3f cwts. 

BLOOD. Mr. Pillans, in 1854, took out a patent for the separation of the coloring 
matter of blood, and also for drying the prepared serous matters. He recommends the blood 
(which must be received warm) to be caught in shallow vessels containing from 14 lbs. to 
20 lbs. of blood, to stand at rest from two to six hours according to the weather and the 
nature of the blood ; then the clot is separated by a strainer from the serous fluid, and by 
means of cutting-knives, or rollers, the clot is divided into small pieces ; a considerable 
quantity of coloring matter flows with the serum, which is to be set aside to deposit ; the 
clot is placed on strainers until the serum has all drained away. By these operations there 
are obtained readily from the blood — 1st, the clot, in a comparatively dry state, comprising 
hematosine, with a portion of serum and all the fibrine ; 2d, a portion of serum, highly 
colored with hematosine ; 3d, the clear serum. 

The blood, in small fragments, is dried on wirework or trays, at a less temperature than 
will coagulate the hematosine, so that, when dry, it may be soluble in water ; 110° to 115° 





is the temperature recommended. The second or highly-colored serum can be dried by 
itself or mixed with the serum, and may be used for sugar refining and in dyeing. 

The clear serum is dried and ground and in a fit state to be used as albumen, and may 
be employed by the printers of textile fabrics for fixing ultramarine blue and other colors, 
or as a substitute for egg albumen, both in printing colors and in refining liquids. 

Instead of drying at once the clear serum, it may be mixed with $ V eT cent, of oil of 
turpentine. Other vegetable, and, particularly, volatile oils, are also suitable, preferring 
those that have been exposed to the air ; from 10 to 20 per cent, of water, ultramarine, 
suitable colors, or thickening, may be added, taking care that under no circumstance is it to 
be exposed to a heat high enough to coagulate it while in the drying-room. 

BLOODSTONE. A very hard, compact variety of haematite iron ore, which, when 
reduced to a suitable form, fixed into a handle, and well polished, forms the best descrip- 
tion of burnisher for producing a high lustre on gilt coat-buttons. The gold on china is 
burnished by the same means. — Knight. , 

Bloodstone is a name also applied to the jaspery variety of quartz known as the helio- 
trope, colored deep-green, with interspersed blood-red spots like drops of blood — Dana. 

BLOWPIPE. The blowpipe is so extremely useful to the manufacturer and to the 
miner that an exact description of the instrument is required. 

When we propel a flame by means of a current of air blown 
into or upon it, the flame thus produced may be divided into two 
parts, as possessing different properties — that of reducing under 
one condition and of oxidizing under another. 

The reducing flame is produced by blowing the ordinary 
flame of a lamp or candle simply aside by a weak current of air 
impinging on its outer surface ; it is therefore unchanged except 
in its direction. Unconsumed carbon, at a white heat, giving the 
yellow eolor to the flame, coming in contact with the substance, 
aids in its reduction. 

The oxidizing flame is formed by pouring a strong blast of 
air into the interior of the flame ; combustion is thus thoroughly 
established, and if a small fragment of an oxidizable body is held 
just beyond the point of the flame, it becomes intensely heated, 
and, being exposed freely to the action of the surrounding air, it 
is rapidly oxidized. 

The best form of blowpipe is the annexed, (Jig. 66,) which, 
with the description, is copied from Blandford's excellent transla- 
tion of Dr. Theodore Scheerer's " Introduction to the Use of the 
Mouth Blowpipe." 

The tube and nozzle of the instrument are usually made of 
German silver, or silver with a platinum point, and a trumpet- 
shaped mouth-piece of horn or ivory. Many blowpipes have no 
mouth-pieces of this form, but are simply tipped with ivory, or 
some similar material. The air-chamber a serves in some degree 
to regulate the blast and receives the stem, b, and the nozzle, a, 
which are made separately, and accurately ground into it, so that 
they may be put together, or taken apart at pleasure. The point 
6 is best made of platinum, to allow of its being readily cleaned, 
and is of the form shown in the wood-cut. When the in- 
strument is used, the mouth-piece is pressed against the lips, or, 
if this is wanting, the end of the stem must be held between the 
lips of the operator. The former mode is far less wearying than 
the latter ; and whereas, with the trumpet mouth-piece, it is easy 
to maintain a continued blast for five or ten minutes, without it 
it is almost impossible to sustain an unbroken blast of more than 
two or three minutes' duration. While blowing, the operator 
breathes through his nostrils only, and, using the epiglottis as a 
valve, forces the air through the blowpipe by means of the cheek 

Some years since, Mr. John Prideaux, of Plymouth, printed some valuable " Sugges- 
tions" for the use of the blowpipe by working miners. Some portions of this paper appear 
so useful, especially under circumstances which may preclude the use of superior instru- 
ments, &c, that it is thought advisable to transfer them to these pages. 

For ordinary metallurgic assays, the common blowpipe does very well. A mere taper- 
ing tube, 10 inches long, £ inch diameter at one end, and the opening at the other scarcely 
equal to admit a pin of the smallest kind, the smaller end curved off for 1+ inch to a right 
angle. A bulb at the bend, to contain the vapor condensed from the breath, is useful in long 
operations, but may generally be dispensed with. In selecting the blowpipe, the small 



aperture should be chosen perfectly round and smooth, otherwise it will not command a 
good flame. 

A common candle, such as the miner employs under ground, answers very well for the 

To support the subject of assay, or " the assay," as it has been happily denominated by 
Mr. Children, two different materials are requisite, according as we wish to calcine or re- 
duce it. For the latter purpose, nothing is so good as charcoal ; but that from oak is less 
eligible, both from its inferior combustibility and from its containing iron, than that from 
alder, willow, or other light woods. 

For calcination, a very convenient support, where platinum wire is difficult to procure, 
is white-baked pipe-clay or china clay, selecting such as will not fuse nor become colored by 
roasting with boras. 

These supports are conveniently formed by a process of Mr. Tennant. The clay is to be 
beaten to a smooth stiff body ; then a thin cake of it, being placed between a fold of writing 
paper, it is to be beaten out with a mallet to the thickness of a wafer, and cut, paper and 
all, into squares of f inch diameter, or triangles about the same size. These are to be put 
in the bowl of a tobacco-pipe, and heated gently till dry, then baked till the paper is burnt 
away, and the clay left perfectly white. They should be baked in a clear fire, to keep out 
coal-dust and smoke as much as possible, as either of these adhering to the clay plates 
would color the borax in roasting. A small fragment of the bowl of a new tobacco-pipe 
will serve instead in the absence of a more convenient material. 

A simple pair of forceps, (Jig. 67), to move and to take up the hot assay, may be made 
of a slip of stiff tin plate, 8 inches long, \ inch wide in the middle, and Vi 6 inch at the 

ends. The tin being rubbed off the points on a rough 

6 ' whetstone, the slip is to be bent until they approach each 

/j||jjp " ~~} other within -J an inch, and the two sides are parallel ; 

thus there will be spring enough in the forceps to open 
"2^, and let go the assay when not compressed upon it by the 
finger and thumb. 

A magnetic needle, very desirable to ascertain the presence of iron, is easily made of 
the requisite delicacy where a magnet is accessible. A bit of thin steel wire, or a long fine 
stocking-needle, having \ inch cut off at the point, is to be heated in the middle that it 
may be slightly bent there,' (fig. 68.) While hot, a bit of sealing-wax is to be attached to 
the centre, and the point which had been cut off, being heated 
68 at the thick end, is to be fixed in the sealing-wax, so that the 

sharp end may serve as a pivot, descending about -j- inch below 
the centre, taking care that the ends of the needle fall enough 
below the pivot, to prevent it overturning. It must be mag- 
netized, by sliding one end of a magnet half a dozen or more 
times from the centre to one end of the needle, and the other 
end a similar number of times from the centre of the needle to 
its other end. A small brass thimble (not capped with iron) will do for the support, the 
point of the pivot being placed in one of the indentations near the centre of the tap, when, 
if well balanced, it will turn until it settles north and south. If one side preponderate, 
it must be nipped until the balance be restored. 

A black gun-flint is also occasionally used to rub the metallic globules, (first attached, 
whilst warm, to a bit of sealing-wax,) and 'ascertain the color of the streak which they give. 
Thus minute particles of gold, copper, silver, &c, are readily discriminated. A little refined 
borax and carbonate of soda, both in powder, will complete the requisites. 

Having collected these materials, the next object for the operator is to acquire the 
faculty of keeping up an unintermitted blast through the pipe whilst breathing freely 
through the nose. 

A very sensitive, and, for most purposes, sufficiently delicate balance, (fig. 69,) was 
also devised by Mr. Prideaux, of which the following is a description : — 



The common marsh reed, growing generally in damp places throughout the kingdom, 
will yield straight joints, from 8 to 12, or more, inches long ; an 8-inch joint will serve, but 
the longer the better. This joint is to be split down its whole length, so as to form a 



trough, say ^ inch wide in the middle, narrowed away to J inch at the ends. A narrow 
slip of writing paper, the thinner the better, (bank post is very convenient for the purpose,) 
and as long as the reed trough, is to be stuck with common paste on the face of a carpen- 
ter's rule, or, in preference, that of an exciseman, — as the inches are divided into tenths 
instead of eighths ; — in either case observing that the divisions of the inch on the rule be 
lift uncovered by the paper. When it is dry, lines must be drawn the whole length of it, 
^ inch apart, to mark out a stripe -J inch wide. Upon this stripe the divisions of the inch 
are to be ruled off by means of a small square. 

The centre division being marked 0, it is to be numbered at every fourth line to the 
ends. Thus the fourth from the centre on each side will be 10 ; the eighth, 20 ; the 
twelfth, 30 ; -the sixteenth, 40, &c. ; and a slip of 10 inches long, graduated into tenths of 
an inch, will have on each arm 50 lines, or 125 degrees, divided by these lines into quar- 
ters. While the lines and numbers are drying, the exact centre of the reed-trough may be 
ascertained, and marked right across, by spots on the two edges. A line of gum water, 
full \ inch wide, is then laid with a camel-hair pencil along the hollow, and the paper 
being stripped from the rule, (which it leaves easily,) the graduated stripe is cut out with 
scissors, and laid in the trough, with the line exactly in the centre. Being pressed to the 
gummed reed, by passing the round end of a quill aloug it, it graduates the trough from the 
centre to each end. This graduation is very true, if well managed, as the paper does not 
stretch with the gum water after being laid on the rule with the paste. 

A very fine needle is next to be procured, (those called bead-needles are the finest,) and 
passed through a slip of cork the width of the centre of the trough, about ^ inch square, 
\ thick. It should be passed through with care, so as to be quite straight. The cork 
should then be cut until one end of it fits into the trough, so that the needle shall bear on 
the edges exactly in the spots that mark the centre, as it is of importance that the needle 
and the trough be exactly at right angles with each other. The cork is now to be fixed in 
its place with gum water, and, when fast dry, to be soldered down on each side with a small 
portion of any soft resinous cement, on the point of a wire or knitting-needle •, a little 
cement being also applied in the same manner to the edges of the cork where the needle 
goes through, to give it firmness, the beam is finished. It may be balanced by paring the 
edges on the heaviest side : but accurate adjustment is needless, as it is subject to vary with 
the dampness or the drvness of the air. 

The support on which it plays is a bit of tin plate, (or, in preference, brass plate,) If 
inch long, and 1 inch wide. The two ends are turned up square -f of an inch, giving a base 
of f of an inch wide, and two upright sides f- high. The upper edges are then rubbed 
down smooth and square upon a Turkey stone, letting both edges bear on the stone to- 
gether, that they may exactly correspond. For use, the beam is placed evenly in the sup- 
port, with the needle resting across the edges. Being brought to an exact balance by a bit 
of writing paper, or any other substance, placed on the lighter side, and moved toward the 
end until the equilibrium is produced, it will turn with extreme delicacy, a bit of horsehair, 
£ inch long, being sufficient to bring it down freely. 

It must not be supposed that any such instrument as this is recommended as in any way 
substituting the beautiful balances which are constructed for the chemist, and others requir- 
ing to weigh with great accuracy. The object is merely to show the miner a method by 
which he may construct for himself a balance which shall be sufficiently accurate for such 
blowpipe investigations as it may be important for him to learn to perform for himself. If 
the suggestions of the chemist who devised the above balance had been carried out, much 
valuable mineral matter which has been lost might have been turned to profitable account. 

The blowpipe is largely used in manufactures, as in soldering, in hardening and temper- 
ing small tools, in glass-blowing, and in enamelling. In many cases the blowpipes are used 
in the mouth, but frequently they are supplied with air from a bellows moved by the foot, 
by vessels in which air is condensed, or by means of pneumatic apparatus. 

Many blowpipes have been invented for the employment of oxygen and hydrogen, by 
the combustion of which the most intense heat which we can produce is obtained. Pro- 
fessor Hare, of Philadelphia, was the first to employ this kind of blowpipe, when he was 
speedily followed by Clark, Gurney, Leeson, and others. The blowpipe, fed with hydro- 
gen, is employed in many soldering processes with much advantage. 

The general form of the " workshop blowpipe " is that of a tube open at one end, and 
supported on trunnions in a wooden pedestal, so that it may be pointed vertically, horizon- 
tally, or at any angle as desired. Common street gas is supplied through one hollow trun- 
nion, and it escapes through an annular opening, while common air is admitted through the 
other trunnion, which is also hollow, and is discharged in the centre of the hydrogen through 
a central conical tube ; the magnitude and intensity of the flame being determined by the 
relative quantities of gas and air, and by the greater or less protrusion of the inner cone, by 
which the annular space for the hydrogen is contracted in any required degree. — Holtz- 

' BLUE COPPERAS, or BLUE STONE. The commercial or common names of the 
sulphate of copper. See Copper. 



BLUE VITRIOL. Sulphate of copper. When found in nature, it is due entirely to 
the decomposition of the sulphides of copper, especially of the yellow copper pyrites, which 
are liable to this change when placed under the influence of moist air, or of water contain- 
ing air. 

BOGHEAD COAL, and other Brown Cannel Coals. The brown cannels are chiefly 
confined to Scotland, and have been wrought, with the exception of the celebrated Bog- 
head, for the last thirty years. They are found at, near Bathgate ; Eocksoles, 
near Airdrie ; Pirnie, or Methill ; Capeldrea, Kirkness, and Wemyss, in Fife. The first- 
named coal, about which there has been so much dispute as to its nature, has only been in 
the market eight years. It is considered the most valuable coal hitherto discovered for gas 
and oil-making purposes ; but, strange to say, the middle portion of the Pirnie, o"r Met- 
hill seam, which has been unnoticed for thirty years, is nearly as valuable for both pur- 
poses. « 

Boghead. Amorphous ; fracture subconchoidal, compact, containing impressions of 
the stems of Sigillaria, and its roots, (Stigmarim,) with rootlets traversing the mass. 
Color, clove-brown, streak yellow, without lustre ; a non-electric ; takes fire easily, splits, but 
does not fuse, and burns with an empyreumatic odor, giving out much smoke, and leaving 
a considerable amount of white ash. H. 25. Specific gravity, 1-200. 

According to Dr. Stenhouse, F. R. S., its composition is: — 

Carbon 65-72 

Hydrogen 9-03 

Nitrogen o-72 

Oxygen- - - - i 4.78 

Ash 19-75 

Dr. Stenhouse's analysis of the ash of Boghead coal, from three analyses, was as fol- 
lows : — 

Silica 58-31 

Alumina '- 33-65 

Sesquioxide of iron 7 -00 

Potash 0-84 

Soda 0-41 

Lime and sulphuric acid --------- traces. 

Dr. Andrew Fyfe, F. R. S. E., on analysis, found that the coal yielded, from a picked 
specimen, 70 per cent, of volatile matter, and 30 per cent, of coke and ash. From a ton 
he obtained 14-880 cubic feet of gas, the illuminating power of which was determined by 
the use of the Bunsen photometer, the gas being consumed by argands burning from 2-J to 
3-} feet per hour, according to circumstances. The candle referred to was a spermaceti 
candle, burning 140 grains per hour. 

Cubic Feet of 

Gas per Ton of 



by Chlorine 
In 100 Parts. 

Durability 1 foot 

Power 1 foot = 
Light of Candles. 

Pounds of Coke 

per Ton of 





Min. Sec. 
88 25 



The Pirnie or Methill brown cannel, on analysis, gives the following results : — 

Specific gravity 1-126 

Gas per ton • - - 13,500 feet. 

Illuminating power ...... - 28 candles. 

Coke and ash 36 per cent. 

Hydro-carbons condensed by bromine ... - 20 " 

Sulphuretted hydrogen ------- i" 

Carbonic acid ........ 4f" 

Carbonic oxide - - - - - - - - 7f" 

Volatile matter in coal - - - - - - _ 65" 

Specific gravity of gas - - -700 " 

The Boghead coal occurs in the higher part of the Scotch coal field ; in about the posi- 
tion of the " slaty band " of ironstone, its range is not more than 3 or 4 miles in the lands 
of Torbane, Inchcross, Boghead, Capper's, and Bathvale, near Bathgate, in the county of 
Linlithgow. In thickness it varies from 1 to 30 inches, and at the present consumption, say 
from 80,000 to 100,000 tons per annum, it cannot last many years. 



The following section of a pit at Torbane shows that the eannel occurs in ordinary coal 
measures, and under circumstances common to beds of coal : — 

Ft. In. 

Boghead house coal 27 

Arenaceous shale .....--..6 

Slaty sandstone 07 

Shale and ironstone, containing remains of plants and shells - 10 

Cement stone (impure ironstone) 4 

Boghead eannel 1 9 

Fire clay, full of Stigmarice -------05 

Coal (common) 06 

Black shale Of 

Coal - 1 

Shale Of 

Coal OJ 

Fire clay U 

Hard shale - - - - - - - - - -03 

Thin laminae of coal and shale -- 3£ 

Common coal - - - - - - - - - -0 6 

Fire clay 

One of the chief characters of this eannel is its indestructibility under atmospheric 
agencies ; for whether it is taken from the mine at a depth of fifty fathoms, or at the out- 
crop, its gas and oil-yielding properties are the same. Even a piece of the mineral taken 
out of the drift deposits, where it had most probably lain for thousands of years, appears 
to be just the same in quality as if it had been but lately raised from the mine. 

In the earth the seam lies parallel to its roof and floor, like other beds of coal ; and it is 
traversed by the usual vertical joints, dividing it into the irregular cubes which so generally 
characterize beds of eannel. The roof lying above the cement stone contains remains of 
Catamites ; and the ironstone nodules, fossil shells of the genus Unio, The floor of the 
mine contains Stigmarice ; and the coal itself affords more upright stems of Sigillarice, and 
its roots (Stigmarice) and their radicles, running through the seam to a considerable dis- 
tance, than the majority of coals show. In these respects it entirely resembles the Pirnie 
or Methill seam. Most canuels afford remains of fish ; but in Boghead no traces of these 
fossils have yet been met with, although they have been diligently sought after. 

The roots in the floors, and the upright stems of trees in the seam itself, appear to show 
that the vegetable matter now forming the coal grew on the spot where it is found. If the 
mangroves and other aquatic plants, at the present day found growing in the black vegetable 
mud of the marine swamps of Brass town, on the west coast of Africa, were quietly sub- 
merged and covered up with clay and silt, we should have a good illustration of the forma- 
tion of a bed of carbonaceous matter showing no structure, mingled with stems and roots 
of trees showing structure, which is the case of Boghead coal, the structure being only de- 
tected in those parts showing evidence of stems and roots, and not in the matrix in which 
those fossils are contained. 

The chemical changes by which vegetable matter has been converted into Boghead ean- 
nel will not be here dwelt on ; but the chief peculiarity about the seam is its close and 
compact roof, composed of cement stone and shale. This is perfectly water and air-tight, 
so much so that, although the mine is troubled with a great quantity of water, it all comes 
through the floor, and not the roof. This tight covering of the coal has doubtless exercised 
considerable influence on the decomposing vegetable matter after the latter had been sub- 
merged. It is worthy of remark, that, above the Pirnie or Methill seam, — the coal nearest 
approaching Boghead, — a similar bed of impure ironstone occurs. 

Away from whin dykes which traverse the coal field, there are no appearances of the 
action of an elevated temperature, either upon the coal or its adjoining strata, to give any 
sanction to the hypothesis that the eannel has resulted from the partial decomposition of a 
substratum of coal by the heat of underlying trap, the volatile matters having been retained 
in what has probably been a bed of shale. First, it must be understood that Boghead ean- 
nel, even when treated with boiling naphtha, affords scarcely a trace of bitumen ; and, 
■secondly, when the seam of coal is examined in the neighborhood of a whin dyke, where 
heat has evidently acted on it, it is found nothing like eannel, but as a soft sticky substance, 
of a brown color, resembling burnt Indian-rubber. Besides these facts, the seams of coal 
and their accompanying strata, both above and below the eannel, show no signs of the ac- 
tion of heat, but, on the contrary, exhibit every appearance of having been deposited in the 
usual way, and of remaining without undergoing any particular alteration. — E. W. B. 

BOGHEAD NAPHTHA, (syn. Bathgate naphtha,) naphtha from the Boghead coal. See 
Naphtha, Boghead. 

BOG IRON ORE is an example of the recent formation of an ore of iron, arising from 
the decomposition of rocks, containing iron, by the action of water charged with carbonic 



acid. The production of this ore of iron in the present epoch, explains to us many of the 
conditions under which some of the more ancient beds of iron ore have been produced. 

Bog iron ore is common in the peat bogs of Ireland and other places. 

The iron manufactured from bog iron ore is what is called " cold short," from the pres- 
ence of phosphorus ; it cannot, therefore, be employed in the manufacture of wire, or of 
sheet iron ; but, from the fluidity of the metal, it is valuable for casting. 

It varies much in composition, some specimens giving 20 and others TO per cent, of the 
peroxide of iron. Protoxide of iron and oxide of manganese are often present ; and as 
much as 10 per cent, of phosphorus and organic matter have been detected. See Iron. 

BOILER. See Boilers, vol. i. 

BOLE. A kind of clay, often highly colored by iron. It usually consists of silica, alu- 
mina, iron, lime, and magnesia. It is not a well-defined mineral, and, consequently, many 
substances are described by mineralogists as bole. ■ 

Armenian bole is of a bright red color. This is frequently employed as a dentifrice, 
and in some cases it is administered medicinally. 

Bole of Blois is yellow, contains carbonate of lime, and effervesces with acids. 

Bohemian bole is a yellowish red. 

French bole is of a pale red, with frequent streaks of yellow. 

Lemnian bole and Silisean bole are, in most respects, similar to the above-named va- 

The following analysis are by C. Van Hauer : — 

Capo di Bove — Silica, 45 - 64 ; alumina, 29 - 33 ; peroxide of iron, 8 - 88 ; lime, 0'60 ; 
magnesia, a trace ; water, 14 - 2'7 = 98'72. 

New Holland — Silica, 38 - 22 ; alumina, 31'00; peroxide of iron, ll'OO; lime, a trace; 
magnesia, a trace ; water, 18 - 81 = 99 - 03. 

BOLOGNIAN STONE. A sulphate of barytes, found in roundish masses, which phos- 
phoresces when, after calcination, it is exposed to the solar rays. 

BOMBAZINE. A worsted stuff mixed with silk ; it is a twilled fabric, of which the warp 
is silk and the weft worsted. 

BOMBYX MORI. The moth to which the silkworm turns. This species was originally 
brought from China. In this country the eggs of this moth are hatched early in May. The 
caterpillar (silkworm) is at first of a dark color ; but gradually, as with all other caterpillars, 
it becomes lighter colored. This worm is about eight weeks in arriving at maturity, during 
which time it frequently changes its color. When full grown, the silkworm commences 
spinning its web in some convenient place. The silkworm continues drawing its thread 
from various points, and attaching it to others ; it follows, therefore, that, after a time, the 
body becomes, in a great measure, enclosed in the thread. The work is then continued 
from one thread to another, the silkworm moving its head and spinning in a zigzag way, 
bending the fore part of the body back to spin in all directions within reach, and shifting 
the body only to cover with silk the part which was beneath it. As the silkworm spins its 
web by thus bending the fore part of the body back, and moves the hinder part of the body 
in such a way only as to enable it to reach the farther back with the fore part, it follows 
that it encloses itself in a cocoon much shorter than its own body ; for soon after the begin- 
ning, the whole is continued with the body in a bent position. During the time of spinning 
the cocoon, the silkworm decreases in length very considerably ; and after it is completed 
it is not half its original length ; at this time it becomes quite torpid, soon changes its skin, 
and appears in the form of a chrysalis. The time required to complete the cocoon is five 
days. In the chrysalis state the animal remains from a fortnight to three weeks ; it then 
bursts its case, and comes forth in the imago state, the moth having previously dissolved a 
portion of the cocoon by means of a fluid which it ejects. — Penny Magazine. 

BON-BONS. Comfits and other sweetmeats of various descriptions pass under this name. 
A large quantity is regularly imported from France into this country, and, from its usually 
superior quality, it is much in request. The manufacture of sweetmeats, confectionary, &c, 
does not enter so far into the plan of this work as to warrant our giving any special detail 
of the various processes employed. 

Liqueur Bon-bons are made in the following manner : — A syrup evaporated to the proper 
consistence is made, and some alcoholic liqueur is added to it. Plaster of Paris models of 
the required form are made ; and these are employed, several being fastened to a rod, for 
the purpose of making moulds in powdered starch, filling shallow trays. The syrup is then, 
by means of a funnel, poured into these moulds, and there being a powerful repulsion be- 
tween the starch and the alcoholic syrup, the upper portion of the fluid assumes a spherical 
form ; then some starch is sifted over the surface, and the mould is placed in a warm closet. 
Crystallization commences on the outside of the bon-bon, forming a crust inclosing the 
syrup, which constantly gives up sugar to the crystallizing crust until it becomes sufficiently 
firm to admit of being removed. A man and two boys will make three hundredweights of 
bon-bons in a day. 

BONES. 169 

Crystallized Bon-bons are prepared by putting them with a strong syrup contained in 
shallow dishes, placed on shelves in the drying chamber, pieces of linen being stretched 
over the surface, to prevent the formation of a crust upon the surface of the fluid. In two 
or three days the bon-bons are covered with crystals of sugar ; the syrup is then drained 
off, and the comfits dried. 

Painted Bon-bons. — Bon-bons are painted by being first covered with a layer of glazing ; 
they are then painted in body colors, mixed with mucilage and sugar. 

The French have some excellent regulations, carried out under the " Prefet de Police," 
as to the colors which may be employed in confectionary.' These are to the following 
effect :— 

" Considering that the coloring matter given to sweets, bon-bons, liqueurs, lozenges, 
&c, is generally imparted by mineral substances of a poisonous nature, which imprudence 
has been the cause of serious accidents ; and, that the same character of accidents have 
been produced by chewing or sucking the wrapping paper of such sweets, it being glazed 
and colored with substances which are poisonous ; it is expressly forbidden to make use of 
any mineral substance for coloring liqueurs, bon-bons, sugar-plums, lozenges, or any kind of 
sweetmeats or pastry. No other coloring matter than such as is of a vegetable character 
shall be employed for such a purpose. It is forbidden to wrap sweetmeats in paper glazed 
or colored with mineral substances. It is ordered that all confectioners, grocers, dealers in 
liqueurs, bon-bons, sweetmeats, lozenges, &c, shall have their name, address, and trade 
printed upon the paper in which the above articles shall be enclosed. All manufacturers and 
dealers are personally responsible for the accidents which shall be traced to the liqueurs, 
bon-bons, and other sweetmeats manufactured or sold by them." 

If similar provisions were in force in this country, it would prevent the use, to an alarm- 
ing extent, in our cheap confectionary, of such poisonous substances as 

Arsenite of copper, 
Acetate of copper, 
Chromate of lead, 

Sulphide of arsenic, 

Oxide of lead, 

Sulphide of mercury, &c. 

The coloring matters allowed to be used in France are indigo, Prussian blue, saffron, 
Turkey yellow, quercitron, cochineal, Brazil wood, madder, &c. 

BOXES. Heintz found that the fixed bases in the bones were sufficient to saturate 
completely the acids contained in them, so that the phosphate of lime, as well as the phos- 
phate of magnesia, which the bones contain, is composed, according to the formula 3RO, PO 5 . 
Bone phosphate of lime was considered by Berzelius to be 8CaO, 3PO\ True bony struc- 
ture is perfectly free from chlorides, from sulphates, and from iron, these salts being only 
found when the liquid pervading the bones has not been completely removed. The bones 
in youth contain less earthy constituents than those of adults ; and, in advanced age, the 
proportion of mineral matters increases. Von Biria found more bone earth in the bones of 
birds than in those of mammals ; he found also the ratio of the carbonate of lime to the 
phosphate to be generally greater. In the bones of amphibia, he found less inorganic mat- 
ter than in those of mammals and birds ; and, in the bones of fishes, the earthy matters 
vary from 21 to 57 per cent. The scales of fishes have a composition somewhat similar to 
that of bone, but they contain phosphate of lime in small quantity only. 

In certain diseases, (the craniotabes in children,) the earthy salts fall in the spongy por- 
tion of the bone as low as 28-16 per cent, of the dry bone ; and in several cases the propor- 
tion of earthy matter was found by Sehlossberger as low as 50 per cent. At the age of 21 
years, the weight of the skeleton is to that of the whole body in the ratio of 10 - 5 : 100 in 
man, and in that of 8-5 : 100 in woman, the weight of the body being about 125 or 130 lbs. 

The quantity of organic matter in fossil bones varies very considerably : in some cases 
it is found in as large a quantity as in fresh bones, while in others it is altogether wanting. 
Carbonate of lime generally occurs in far larger quantity in fossil than in recent bones, 
which may arise from infiltration of that salt from without, or from a decomposition of a 
portion of the phosphate of lime by carbonic acid or carbonates. Magnesia often occurs in 
larger quantities in the fossil remains of vertebrated animals than in the fresh bones of the 
present animal world. Liebig found in the cranial bones excavated at Pompeii a larger 
proportion of fluoride of calcium than in recent bones ; while, on the other hand, Girar- 
din and Preisser found that this salt had greatly diminished in bones which had lain long in 
the earth, and, in some cases, had even wholly disappeared. 

The gelatinous tissue of bones was found by Von Biria to consist of 

Ox bones. Fossil bones. 

Carbon .... 50-401 .... 50-130 

Hydrogen .... 7-111 - - - - 7-073 

Nitrogen .... 18-154 .... 18-449 

• Oxygen .... 24-119 .... 24"348 
Sulphur .... 0-21(5 
This is the same composition as that of the gelatinous tissues. 



In the arts, bones are employed by turners, cutlers, manufacturers of animal charcoal, 
and, when calcined, by assayers, for making cupels. In agriculture, they are employed as 
a manure. Laid on in the form of dust, at the rate of 30 to 35 cwts. per acre, they have 
been known to increase the value of old pastures from 10s. or 15s. to 30s. or 40s. per acre ; 
and after the lapse of 20 years, though sensibly becoming less valuable, land has remained 
still worth two or three times the rent it paid before the bones were laid on. In the large 
dyeing establishments in Manchester, the bones are boiled in open pans for 24 hours, the 
fat skimmed off' and sold to the candle makers, and the size afterwards boiled down in an- 
other vessel till it is of sufficient strength for stiffening the thick goods for which it is in- 
tended. The size liquor, when exhausted or no longer of sufficient strength, is applied with 
much benefit as a manure to the adjacent pasture and artificial grass lands, and the ex- 
hausted bones are readily bought up by the Lancashire and Cheshire farmers. When burned 
bones are digested in sulphuric acid diluted with twice its weight of water, a mixture of 
gypsum and acid phosphate of lime is obtained, which, when largely diluted with water, 
forms a most valuable liquid manure for grass land and for crops of rising corn ; or, to the 
acid solution, pearl ashes may be added, and the whole then dried up, by the addition of 
charcoal powder or vegetable mould, till it is sufficiently dry to be scattered with the hand 
as a top dressing, or buried in the land by means of a drill. 

In France, soup is extensively made by dissolving bones in a steam heat of two or three 
days' continuance. Respecting the nutritive property of such soup, Liebig has expressed 
the following strong opinion : — " Gelatine, even when accompanied by the savory constitu- 
ents of flesh, is not capable of supporting the vital process ; on the contrary, it diminishes 
the nutritive value of food, which it renders insufficient in quantity and inferior in quality, 
and it overloads the blood with nitrogenous products, the presence of which disturbs and 
impedes the organic processes." The erroneous notion that gelatine is the active principle 
of soup, arose from the observation that soup made, by boiling, from meat, when concen- 
trated to a certain point, gelatinizes. The jelly was taken to be the true soup until it was 
found that the best meats did not yield the finest gelatine tablets, which were obtained most 
beautiful and transparent from tendons, feet, cartilage, bones, &e. This led to an investiga- 
tion on nutrition generally, the results of which provexl that gelatine, which by itself is 
tasteless, and when eaten excites nausea, possesses no nutritive value whatever. 

The following table exhibits the relation between the combustible animal matter and the 
mineral substances of bones, as found by different observers : — 

Organic Portion. 

Inorganic Portion. 


Ox bones - 

Human bones - - - 
Bird bones 







1-8 to 2-3 ) 

2 - in mean \ 

1-6 to 2-2 j 

1"9 in mean j- 

2-3 to 2-6 ) 


Von Biria. 

Prior to the use of bones by the turner or carver, they require the oil with which they 
are largely impregnated, to be extracted, by boiling them in water, and bleaching them in 
the sun or otherwise. This process of boiling, in place of softening, robs them of part of 
their gelatine, and therefore of part of their elasticity and contractibility likewise, and they 
become more brittle. 

The forms of the bones are altogether unfavorable to their extensive or ornamental 
employment : most of them are very thin and curved, contain large cellular cavities for 
marrow, and are interspersed with vessels that are visible after they are worked up into 
spoons, brushes, and articles of common turnery. The buttock and shin bones of the ox 
and calf are almost the only kinds used. To whiten the finished works, they are soaked in 
turpentine for a day, boiled in water for about an hour, and then polished with whitening 
and water. 

Holtzapffel also informs us, that after the turning tool, or scraper, has been used, bone is 
polished, 1st, with glass paper ; 2d, with Trent sand, or Flanders brick, with water on flan- 
nel ; 3d, with whiting and water on a woollen rag ; 4th, a small quantity of white wax is 
rubbed on the work with a quick motion ; the wax fills the minute pores, but only a very 
minute portion should be allowed to remain on the work. Common bone articles, such as 
nail and tooth brushes, are frequently polished with slaked lime used wet on flannel or 
woollen cloth. See " On Bone and its Uses," by Arthur Aitkin, Trans, of Society of Arts, 
1832 and 1839. 

The importance of the trade in bones will be seen from the following statement of Im- 
ports, in 1856, of the bones of animals and fish — not whalebone. 




Computed real Value. 

Eussia ------ 

Norway ------ 




Hanse Towns 

Holland - 


Spain - - 

Tuscany -..--.- 

Two Sicilies 

Austrian Italy 

Turkey Proper 

United States ...,.- 
Brazil ------- 


Buenos Ayres - - - - ' - 

Australia ------ 

Other parts 


2,636 ' 




























In 1857, of bones, whether burnt or not, or as animal charcoal, 63,951 tons. — H. M. N. 

BONE BLACK. The composition of perfectly dry bone black of average quality is as 
follows: — Phosphate of lime, with carbonate of lime, and a little sulphuret of iron, or oxide 
of iron, 88 parts ; iron in the state of silicated carburet, 2 parts ; charcoal containing about 
Vis of nitrogen, 10 parts. None of the substances present, except the charcoal, possess 
separately any decolorizing power. 

It was formerly supposed that the peculiar absorbing and decoloring power of animal 
charcoal was only exerted towards bodies of organic origin ; but it was found, by Graham, 
that inorganic substances are equally subject to this action ; and later experiments have 
demonstrated that there are few, if any, chemical compounds which altogether resist the 
absorbing power of charcoal. The action is of a mechanical nature, and in some cases it is 
sufficiently powerful to overcome chemical affinities of considerable power. It is not con- 
fined to charcoal, though pre-eminent in this substance, in consequence of the immense ex- 
tent of surface which its porous structure presents. The action of charcoal in sugar refining 
has been particularly studied by Liidersdorf. When the defecated saccharine juice is 
allowed to flow upon a moist and firmly compressed charcoal filter, pure water is the first 
product that passes through ; but a considerably larger quantity is obtained than was em- 
ployed for moistening the charcoal. Water is then obtained of a decidedly saline character, 
which increases in strength, and after this has passed through for some time, a sweet taste 
becomes perceptible, which gradually increases, and at last entirely masks the saline. This 
purely sweet fluid continues to flow for some time ; after which, the liquid acquires an 
alkaline reaction from the presence of caustic lime ; it then becomes colored, the liquor 
getting gradually darker, till the action of the charcoal ceases. Lime is completely 
abstracted from lime water by bone charcoal ; and, according to the experiments of Cheval- 
lier, lead salts are likewise entirely absorbed, the acetate the most readily. It has also been 
shown by Graham, that iodine even is separated from iodine of potassium. The commercial 
value of animal charcoal has usually been estimated by its decoloring power on sulphate of 
indigo ; its absorbent power, which is a property of equal, perhaps of greater importance, 
may, according to M. Coreuwinder, be determined, approximatively, by the quantity of lime 
which a given weight will absorb. For this purpose he employs a solution of saccharate of 
lime of known strength. An acid liquor is first prepared, composed of 20 grammes of pure 
oil of vitriol diluted with water to exactly 1 litre. A solution of saccharate of lime is then 
prepared, by dissolving 125 to 130 grammes of white sugar in water, adding thereto 15 to 
20 grammes of quick-lime, boiling the liquid, and then filtering to separate the undissolved 
- lime. This solution is prepared of such a nature, that it will be exactly saturated by the 
same volume of the dilute sulphuric acid. By adding the latter to 50 cubic centimetres of 
the liquid filtered from the animal charcoal, it is easy to see how many degrees of the 
burette are required to complete the saturation of the lime. Suppose 35 are required for 
this purpose, 100 — 35 = 65, which represent the proportion of lime absorbed by the char- 
coal : this is, therefore, the number representing the standard. By operating with a burette 
graduated from the bottom, the degree of the charcoal experimented upon may be read 



BOOKBINDING. The process of sewing together the sheets of a book, and securing 
them with a back and side boards. 

Books are said to be either stitched, or in boards, or half-bound, or bound. The first 
consists simply of stitching the sheets together. The second, of placing the sheets, after 
they have been stitched, between millboard sides, which are covered with paper or cloth, 
and with the backs lettered and ornamented. The third is a process of more perfectly se- 
curing the leaves, and of placing them between boards with a back of leather, the side-boards 
being covered with marble paper. Books are whole bound when the sides as well as the 
back are covered with leather. Bookbinding is performed in the following manner : — The 
sheets are first folded into a certain number of leaves, according to the form in which the 
book is to appear, as follows : — 

The folio consists of 
" quarto of 
" octavo of 
" duodecimo of 

2 leaves 
4 " 
8 " 
12 " 

When the leaves are thus folded and arranged in proper order, they are, if the books 
have been long printed, usually beaten upon a stone with a heavy hammer, to make them 
solid and smooth, and are then subjected to severe pressure in a powerful press ; but in the 
case of newly-printed books, pressure alone is considered sufficient. Beating, or severe 
pressure, would spoil the book ; because the ink, not being well dried, would " set off" on 
the opposite pages. 

The employment in bookbinding of a rolling-press for smoothing and condensing the 
leaves, instead of the hammering which books have usually received, is an improvement 
introduced several years ago in the trade by Mr. W. Burn. His press consists of two iron 
cylinders about a foot in diameter, adjustable in the usual way by means of a screw, and 
put in motion by the power of one man, or of two if need be, applied to one or two winch- 
handles. In front of the press sits a boy who gathers the sheets into packets, by placing 
two, three, or four upon a piece of tin plate of the same size, and covering them with an- 
other piece of tin plate, and thus proceeding by alternating tin plates and bundles of sheets 
till a sufficient quantity has been put together, which will depend on the stiffness and 
thickness of the paper. The packet is then passed between the rollers and received by the 
man who turns the winch, and who has time to lay the sheets on one side and to hand over 
the tin plates by the time that the boy has prepared a second packet. A minion Bible may 
be passed through the press in one minute, whereas the time necessary to beat it would be 
twenty minutes. It is not, however, merely a saving of time that is gained by the use of 
the rolling-press ; the paper is made smoother than it would have been by beating ; and 
the compression is so much greater, that a rolled book will be reduced to about five-sixths 
of the thickness of the same book if beaten. A shelf, therefore, that will hold fifty books 
bound in the usual way, would hold nearly sixty of those bound in this manner — a circum- 
stance of no small importance, when it is considered how large a space even a moderate 
library occupies, and that book-cases are expensive articles of furniture. The rolling-press 
is now substituted for the hammer by our principal bookbinders. 

After the sheets have been thus prepared, they are sewed ; for which purpose the sew- 
ing press is employed. See Bookbindert, Vol. I. 

BORACIC ACID. (Acide Borique, Fr. BO 3 ; chemical equivalent, 34-9 ; specific grav- 
ity, 1-83.) Supposed to be the chrysocolla of Pliny. In the seventh century, Geber 
mentions borax ; and it was described by Geoffroy and by Baron in the early part of the 
eighteenth century. Boracic acid was formerly called IIoi>iberg , s sedative salt. 

This acid occurs in several minerals, particularly as tincal, or crude biborate of soda, 
which is found in the form of incrustations in the beds of small lakes in Thibet, where it is 
dug up during the hot season. Sassolin, so called from its having been first obtained from 
one of the localities in Tuscany named Sasso, is native boracic acid. It is found abundantly 
in the crater of Vulcano, one of the Lipari Islands, forming a layer on the sulphur and 
around the fumaroles, or exits, of the sulphurous exhalations. The native stalactitic salt, 
according to Klaproth, contains mechanically mixed sulphate of magnesia and iron, sulphate 
of lime, silica, carbonate of lime, and alumina. Erdmann has stated that sassolin contains 
3-18 per cent, by weight of ammonia, and, instead of being pure boracic acid, that it is a bo- 
rate of ammonia. Native boracic acid is composed of boracic acid, 56-4 ; water, 43'6. — 

Professor Graham, in his " Report on the Chemical Products of the Great Exhibition of 
1851," thus speaks of Larderel's discovery : — 

" The preparation of boracic acid by Count F. de Larderel, of Tuscany, was rewarded by 
a Council medal. Although this well-known manufacture is not recent, having attained its 
full development at least ten years, still the bold originality of its first conception, the per- 
severance and extraordinary resources displayed in the successful establishment, and the 
value of the product which it supplies, will always place the operations of Count de Larderel 



among the highest achievements of the useful arts, and demand the most honorable mention 
at this epoch. The vapor issuing from a volcanic soil is condensed, and the minute pro- 
portion of boraeic acid which it contains (not exceeding - 3 per cent.) is recovered by 
evaporation, in a district without fuel, by the application of volcanic vapor itself as a source 
of heat. The boraeic acid thus obtained greatly exceeds in quantity the old and limited 
supply of borax from the upper districts of India, and has greatly extended the use of that 
salt in the glazes of porcelain, and recently in the making of the most brilliant crystal, when 
combined with the oxide of zinc instead of oxide of lead." — Reports of the Jurors of the 
Great Exhibition of 1851. 

The violence with which the scalding vapors escape from the suffioni gives rise to muddy 
explosions when a lake has been drained by turning its waters into another lake. The mud 
is then thrown out, as solid matters are ejected from volcanoes, and there is formed in the 
bottom of the lake a crowd of little cones of eruption, whose temperatures when in activity 
and play are generally from 12Cf to 145° C, and the clouds which they form in the laguons 
constitute true natural barometers, whose greater or less density rarely disappoints the 
predictions that they announce to the inhabitants of those lagoons. 

The boraeic acid of the Tuscan lagoons is obtained from nine different works belonging 
to Count Larderel, the produce of which is on the average as follows : — 

36,000 lbs. per month. 

Monte Cerboli 
Castel Nuovo 
Monte Kotondo 
San Frederigo 
Lustignano - 









163,855 avoirdupois pounds. 

M. Payen has given the following as the composition of this crude boraeic acid for 
100 kilogrammes : — 

Pure crystallized boraeic acid - - - - - 74 to 84 

Sulphate of ammonia 

of magnesia 
" of lime 
Chloride of iron 
Sand, &c. ) 
Sulphur ) 
Hygroscopic water disengaged at 35° C- 
Azotic organic matter 
Hydrochlorate of ammonia 
Hydrochloric and hydrosulphuric acid 

- 14 to 8 

- 2-5 to 1-25 

7 to 5-75 

- 2-5 to 1 

The processes of chemical alteration taking place beneath the crater of Vulcano, 
already spoken of, may, according to the statement of Hoffmann, depend upon conditions 
very similar to those existing in Tuscany. There, likewise, sulphuretted hydrogen is 
associated with the boraeic acid, and, it would appear, in much greater quantity, since 
the fissures through which the vapor issues are thickly lined with sulphur, which is in 
sufficient quantity to be collected for sale. A profitable factory is established at the 
place, which yields daily, besides boraeic acid and chloride of ammonium, about 1,700 lbs. 
of refined sulphur, and about 600 lbs. of. pure aluin. — Bischof. 
In 1855 our Imports were : — 

Cwts. Computed real Value. 

Boraeic acid from Sardinia 85 - £383 

" " Tuscany - 26,777 - - - 121,163 

" " Gibraltar - 947 - - - 4,285 

And in 18C6 : — 

Boraeic acid from Sardinia - 
" " Tuscany - 

" " Peru ' - 

" " other parts 



- 313 

- 1,453 



Computed real Value. 

- £1,377 

- 110,264 




174 BORAX. 

BORAX. (Borax, Fr. ; Borar, Germ.) Anhydrous Borax is composed of 

1 equivalent of boracic acid - - - 872 or 69-0 

1 " soda 390 " 31"0 

1262 for 100-0 ' 
Octahedral Borax — 

1 equivalent of boracic acid - - - 872 or 47 -7 

1 soda 390 " 21-3 

5 " water - 562-5 " 31'0 

1824-5 for 100-0 
Prismatic Borax — 

1 equivalent of boracic acid - - - 872 or 36-55 

1 " soda 390 " 16-35 

10 " water .... 1-125 " p 47-1 

2-387 for 100-00 
Tincal was originally brought from a salt lake in Thibet ; the borax was dug in masses 
from the edges and shallow parts of the lake ; and in the course of a short time the 
holes thus made were again filled. The borate of soda has been found at Potosi, in Peru ; 
and it has been discovered by Mr. T. Sterry Hunt, of the Geological Survey, in Canada', 
from whose report the following extract is made : — 

" In the township of Joly there occurs a very interesting spring on the banks of the 
Ruisseau Magnenat, a branch of the Riviere Souci, about five miles from the mills of 
Methot at Saint Croix. The spring furnishes three or four gallons a minute of a water 
which is sulphurous to the taste and smell, and deposits a white matter along its channel, 
which exhibits the purple vegetation generally met with in sulphur springs. The tem- 
perature of this spring in the evening of one 7th of July was 46° F., the air being 52° F. 
The water is not strongly saline, but when concentrated is very alkaline and salt to the 
taste. It contains, besides chlorides, sulphates, and carbonates, a considerable propor- 
tion of boracic acid, which is made evident by its power of reddening paper colored by 
turmeric, after being supersaturated with hydrochloric acid. . . . The analysis of 
1,000 parts of the water gave as follows: — 

Chloride of sodium 0'3818 

" potassium ....... 0-0067 

Sulphate of soda 0'0215 

Carbonate and borate of do. 0.2301 

of lime 0-0620 

" magnesia 0-0257 

Silica - - - - 0-0245 

Alumina - - - - a trace 

" The amount of boracic acid estimated was found to be equal to 0-0279." 
Professor Bechi has analyzed a borate occurring as an incrustation at the Tuscan 
lagoons, which afforded boracic acid 43-56, soda 19-25, and water 37'19. Lagonite is a 
mineral of an earthy yellow color, which appears to be boracic acid and iron ; while Lar- 
dcrellite, also from Tuscany, is a compound of boracic acid and soda. See Dana, and 
" American Journal of Science." 

BORING. The importance of boring, as a means of searching for coal and for water, 
renders it necessary that some special attention should be given to the subject in a work 
devoted to manufactures and mining. 

Boring for water appears to have been in use from the earliest periods, in Egypt and 
in Asia. In many of the desert tracts there are remains of borings, which served, evi- 
dently, at one period, to supply the wants of extensive populations which once inhabited 
those now deserted regions. In the " Guide du Sondeur," by M. J. Degousee, we find it 
stated, with reference to China, "There exists in the canton of Ou-Tong-Kiao many 
thousand wells in a space often leagues long by five broad. These wells cost a thousand 
and some hundred taels, (the tael being of the value of 6s. 6d.,) and are from 1,500 to 
1,800 feet deep, and about 6 inches in diameter. To bore these wells, the Chinese com- 
mence by placing in the earth a wooden tube of 3 or 4 inches diameter, surmounted by 
a stone edge, pierced by an orifice of 5 or 6 inches ; in the tube a trepan is allowed to 
play, weighing 300 or 400 lbs. A man, mounted on a scaffold, swings a block, which 
raises the trepan 2 feet high, and lets it fall by its own weight. The trepan is secured to 
the swing-lever by a cord made of reeds, to which is attached a triangle of wood ; a man 



sits close to the cord, and at each rise of the swing seizes the triangle and gives it a half 
turn, so that the trepan may take in falling another direction. A change of workmen 
goes on day and night, and with this continuous labor they are sometimes three years in 
boring wells to the requisite depth." 

Boring appears to have been practised in England during the last century, but to a 
very limited extent; it has, however, for a considerable period been employed in seeking 
for coal, and in the formation of wells. 

The ordinary practice of boring is usually carried out, by first sinking a well of such 
a depth that the boring apparatus can be fixed in it; and thus a stage, raised from the 
surface of the ground, is dispensed with. A stout plank floor, well braced, together by 
planks nailed transversely and resting on putlocks, forms the stage. In the centre of the 
floor is a square hole, through which the boring-rods pass. The boring-rods are of many 
different forms. A few are represented in the following figure, (70.) 

1, 2, 3 are an elevation, plan, and section of an auger; the tapped socket is for the 
purpose of allowing the rods to be screwed into it. 

4, 5 are two views of a small auger, with a longitudinal slit, and no valve, which is 
used for boring through clay and loam. In very stiff clay the slit is generally made 
larger ; in moist ground the slit is objectionable. 

6, 7, 8 are different views of a shell, a a are valves opening upwards, to admit the 
material. These tools are used for boring through sand, or through ground which has 
been loosened by other tools. 

9, 10, 11 show an S chisel, for cutting through rocks, flints, and the like. 

Such are the principal tools employed. The boring-rods are turned round by the 
leverage of two handles moved by man, or, where the work is heavy, by horse, or, some- 
times, even steam power is applied. Besides the circular motion of the tool, a vertical 
percussive action of the same is required in certain cases, such as rock or hard sand ; 
indeed, always, where the position of the auger or chisel requires a fresh place to act 
upon during its revolution. This motion is most readily got by suspending the boring- 
rods to a windlass, through the intervention of a rope coiled two or three times round 
the latter, and adjusting it so that if the workman holds one end of the coil tight, suffi- 






6 per fathom. 



of 5 fathoms. 






6 per fathom 




6 " 


176 BOEING. 

cient will be the friction to raise the rods on putting the windlass in motion. Should the 
end of the rope the workman holds now be slackened, the coil becomes loose, and the 
rods descend with a force equivalent to their weight and the distance through which they 
have fallen. A regular percussive action is thus gained by keeping the windlass contin- 
ually in motion in one direction, the attendant workman alternately allowing the rods to 
be drawn up a certain distance, and then, by relaxing his hold, allowing them to fall. — 
— Swindell, on Boring. 

The following list of the prices of boring, in different localities, may prove useful: — 

In the North of England, the prices for boring, in the ordinary strata of the district 

or of that coal field, are as follows : — 

First 5 fathoms ..... 

Second 5 " 

Third 5 " ...... 

Fourth 5 " ..... 

and so increasing 5s. 6d. per fathom on each succeeding 

unusually hard strata are met with, the borer is paid by special arrangement, unless a 
binding contract has been previously made. It is sometimes usual for the borer to take 
all risk of hard strata, when the prices are as follows, the borer finding the tools :- 

First 5 fathoms .... 

Second 5 " ..... 

Third 5 " .... 

Fourth 5 " .... 

and so increasing 7s. %d. per fathom on each succeeding depth of 5 fathoms. 

In the Midland Counties, where the strata are more inclined than in the north of Eng- 
land, the prices for ordinary strata are as follows : — 

First 20 yards ----- 

Next 10 " 

" 10 " 

" 10 " 

" 10 " 

and so advancing Is. &d. per yard upon each 10 yards. 

In some localities, where the boring is still more favorable, the prices are as follows, 
— the bore hole being 2+ to 2| inches diameter : — 

s. d. 

First 20 yards 36 per yard. 

Next 10 " 4 6" 

" 10 " 5 6" 

" 10 " 6 6" 

" 10 " 7 6" 

In boring strata of unusual hardness, a special arrangement is made, as before stated, 
and the borer is allowed some payment for filling up and for removing tackling. 
In Scotland the general prices for boring are as follows : — 

s. d. 

First 5 fathoms 5 per fathom 

Second 5 " 10 

Third 5 " 15 " 

Fourth 5 " 20 " 

and so advancing 5s. per fathom for each succeeding 5 fathoms. 

In boring through very hard strata, the work is done either by shaft-work, or at the 
following rates, the bore hole being 2f inches diameter : — 

s. d. 

First 5 fathoms 10 per fathom. 

Second 5 " 20 

Third 5 " 30 " 

The borer usually specifies to have his tackle laid down ready for erecting at the cost 
of the employer. 

As the boring proceeds, it is often necessary to lower pipes into the hole made, to pre- 
vent the falling of fragments from the sides of the cylinder. There are many ingenious 
contrivances for effecting this, which need not be described in this place. See Pit 
Coal, vol. i. 




6 per yard 



6 " 






BORON". One of the non-metallic elements ; it exists in nature in the form of boracic 
acid, and as borax, tincal, &c. 

Homberg is said to have obtained boron from borax in 1702 ; if so, his discovery appears 
to have been forgotten, since it was unknown, except hypothetical]}', to the more modern 
chemists until, in 1808, it was obtained by Gay-Lussac and Thenard, and by Davy in 1808, 
who decomposed boracic acid into boron and oxygen. 

Boron is best obtained by preparing the double fluoride of boron and potassium, 
(3KF 2BF 3 ,) by saturating hydrofluoric acid with boracic acid, and then gradually adding 
fluoride of potassium. The difficultly soluble double compound thus produced is collected 
and dried at a temperature nearly approaching to redness. This compound is then powdered 
and introduced into an iron tube closed at one end, together with an equal weight of potas- 
sium, whereupon heat is applied sufficient to melt the latter, and the mixture of the two 
substances is effected by stirring with an iron wire. Upon the mass being exposed to a red 
heat, the potassium abstracts the fluorine. The fluoride of potassium may afterwards be 
removed by heating the mass with a solution of chloride of ammonium, which converts the 
free potassa into chloride of potassium, and thus prevents the oxidation of the boron, which 
takes place in the presence of fixed alkali ; the chloride of ammonium adhering to the 
boron may be afterwards removed by treatment with alcohol. Boron is a dark greenish- 
brown powder, tasteless, and inodorous ; its chemical equivalent is 10'9, or, according to 
Laurent, ll'O. 

BOTTLE MANUFACTURE. See Glass and Pottery. 

BOULDERING STONE. A name given by the Sheffield cutlers to the smooth flint 
pebbles with which they smooth down the faces of buff and wooden wheels. As these 
stones are usually taken from gravel pits, the name is, no doubt, used in the same sense 
as the geologist uses the word boulder. 

BOX WOOD. (Buis, Fr. ; Buchsbaum, Germ. ;) Buxus sempervirens. — Two varieties 
of box wood are imported into this country. The European is brought from Leghorn, Por- 
tugal, &c. ; and the Turkey box wood from Constantinople, Smyrna, and the Black Sea. 
English box wood grows plentifully at Box Hill, in Surrey, and in Gloucestershire. The 
English box wood is used for common turnery, and is preferred by brass finishers for their 
lathe-chucks, as it is tougher than the foreign box, and bears rougher usage. It is of very 
slow growth, as in the space of 25 years it will only attain a diameter of 1-J to 2 inches. 

Box wood is used for making clarionets and flutes, carpenters' rules, and drawing scales. 
As the wood is peculiarly free from gritty matter, its sawdust is used for cleaning jewellery. 
Box wood is exclusively employed by the wood engraver. See Engraving on Wood. 

A similar wood was imported from America by the name of Tugmtitton, which was used 
for making ladies' fans ; but we cannot learn that it is now employed. 

BRASS. The table on the following page, for the compilation of which we are indebted 
to Mr. Robert Mallet, C. E., presents, in a very intelligible form, the chemical and physical 
conditions of the various kinds of brass : — 

Brass Color, for staining glass, is prepared by exposing for several days thin plates of 
brass upon tiles in the leer, or annealing arch of the glass house, till they are oxidized into 
a black powder, aggregated in lumps. This being pulverized and sifted, is to be again well 
calcined for several days more, till no particles remain in the metallic state, when it will 
form a fine powder of a russet-brown color. A third calcination must now be given with a 
carefully regulated heat, its quality being tested from time to time by fusion with some 
glass. If it makes the glass swell and intumesce, it is properly prepared ; if not, it must be 
still further calcined. Such a powder communicates to glass greens of various tints, passing 
into turquoise. 

When thin narrow strips of brass are stratified with sulphur in a crucible and calcined 
at a red heat, they become friable and may be reduced to powder. This being sifted and 
exposed upon tiles in a reverberatory furnace for 10 or 12 days, becomes fit for use, and is 
capable of imparting a chalcedony — red or yellow — tinge to glass by fusion, according to 
the mode and proportion of using it. 

The glassmakers' red color may be prepared by exposing small plates of brass to a mode- 
rate heat in a reverberatory furnace till they are thoroughly calcined, when the substance 
becomes pulverulent, and assumes a red color. It is then ready for immediate use. 

Mr. Holtzapffel, in his " Mechanical Manipulation," has given some very important 
descriptions of alloys. From his long experience in manufacture, no one was more capable 
than Mr. Holtzapffel to speak with authority on the alloys of copper and zinc. From his 
work the following particulars have been obtained : — 

The red color of copper slides into that of yellow brass at about 4 or 6 ounces of zinc to 
the pound of copper, and remains little altered unto about 8 or 10 ounces ; after this it 
becomes whiter, and when 32 ounces of zinc are added to 16 of copper, the mixture has the 
brilliant silvery color of speculum metal, but with a bluish tint. 

These alloys — from about 8 to 16 ounces to the pound of copper — are extensively used 
Vol. III.— 12 



* E, signifies earthy ; CC, coarse crystalline ; FC, fine crystalline ; FF, fine fibrous ; C, conchoidal ; V, vitreous ; VC, vitreo-conchoidal ; TC, tabular crystalline. 




I s 



["Several of these 

„. ., . are malleable at 
Similor, &c. -< , . v. 

' high tempera- 
te tures. 

Bath metal. 

Dutch brass. 

Rolled sheet brass. 

Normal brass. 

British brass. 

Muntz's patent sheathing. 

German brass. 

German brass, watchmakers'. 

Very brittle 

Ditto Too hard to file 
Ditto or turn ; lustre 

Brittle [ nearly equal to 
Ditto speculum metal. 

Very brittle 

Barely malleable. 


White button metal. 


Brittle zinc. 


Order of 






Order of 




of Mal- 

at 60°. 

HrlH <M<MCM.-lt-ICNi-l.-<t-.i-l 1 -l 

t< 3 

I— 1 i— < I— t ,— ( 



per Square 


g!DiH!OCO(MT-(t-I^H Wfl3(MnHnt-(MCi(OCiHOMCl 
HCMrHr-li-Hi-4r-ti— (i— 1 i — 1 i — 1 i-l t-i 




Tile red 

Reddish yellow, 1 
Ditto 2 
Ditto 3 
Ditto 4 

Yellowish red,- 3 
Ditto 2 
Ditto 1 

Pale yellow 

Full yellow, 1 


Ditto 2 
Deep yellow 
Silver white, 1 

Ditto 2 
Silver gray, 1 
Ash gray, 3 
Silver gray, 2 

Ditto 1 
Ash gray, 4 

Ditto 1 

Ditto 2 
Very dark gray 
Bluish gray 


* 3* 


ir-joi-Mt-HHcoj-- cioonHOQKXNnCHiao 


S.J3P || 





- aO 

o u 

a fco 



ffiOHW^ocinoDxoot-cooOHdW't loono 


++++++-H--H--H-+ MM +++++ ; -J 



- ■— • 



ocficot-oia^wioNo oo co co co ao co co 



for dipping, a process adopted for giving a fine color to an enormous variety of furniture 
work. The alloys with zinc retain their malleability and ductility well unto about 8 or 10 
ounces to the pound ; after this the crystalline character slowly begins to prevail. The 
alloy of 2 zinc and 1 copper may be crumbled in a mortar when cold. In the following list, 
the "quantity of zinc employed to 1 lb. of copper is given : — 

1 to 1A oz. gilding metal for common jewellery. 

3 to 4 oz. Bath metal, pinchbeck, Mannheim gold, Similor ; and alloys bearing various 

names, and resembling inferior jewellers' gold. 
8 oz. Emerson's patent brass. 
10 2 ' 5 oz. Muntz's metal, or 40 zinc and 60 copper. " Any proportion," says the 

patentee, " between the extremes, 50 zinc and 50 copper and 37 zinc and 63 copper, 

will roll and work well at a red heat." 
16 oz. soft spelter solder, suitable for ordinary brass work. 
16^ oz. Hamilton and Parker's patent mosaic gold. 

Brass is extensively employed for the bearings of machinery. Several patents have been 
taken out for compositions varying but slightly. The following, for improvements in cast- 
ing the bearings and brasses of machinery, appears important : — Mr. W. Hewitson, of Leeds, 
directs, in his patent, that the proper mixture of alloy, eopper, tin, and zinc, should be run 
into metal or " chill " moulds, in place of the ordinary mould. In large castings, it is 
found more especially that the metals do not mix intimately in cooling, or, rather, they ar- 
range themselves into groups when cast in sand, and the bearings are found to wear out 
more quickly ; but if the bearings are cast so that the alloy comes in contact with metal, 
the mixture is more intimate, and the bearings last longer than if east in dry or green sand 

Mr. Hewitson generally only applies these chill-metal surfaces of the moulds to those 
parts of a brass, or bearing, that are to receive the shaft or bear the axis of a machine. The 
chills are preferred of iron, perforated with holes ('/i 6 to V 8 inch) for the passage of air or 
vapors ; the surface should be thinly coated with loam, and heated to about 200°. 

Fenton's patent metal consists of copper, spelter, and tin ; it has less specific gravity 
than gun metal, and is described as being " of a more soapy nature," by which, conse- 
quently, the consumption of oil or grease is lessened. 

Many of the patentees of bearing-metals assure us that the metals they now use differ 
very considerably from the statement in their specifications. Surely this requires a careful 

We exported of our brass manufactures, in 1856, 19,198 cwts., the declared real value 
of which was £121,206. 

BRASSING IRON. Iron ornaments are covered with copper or brass by properly 
preparing the surface, so as to remove all organic matter, which would prevent adhesion, 
and then plunging them into melted brass. A thin coating is thus spread over the iron, and 
it admits of being polished or burnished. The electro-magnetic process is now employed 
for the purpose of precipitating brass on iron. This process was first mentioned in Shaw's 
" Metallurgy," in 1844, where he remarks, " In depositing copper upon iron, a solution of 
the cyanide or acetate of copper should be employed. The only value of these salts is, that 
a die or surface of iron m£y be immersed in their solutions without receiving injury by the 
corrosion consequent upon the deposition of a film of metal by chemical action." The fol- 
lowing solutions are recommended by Dr. Woods, in the " Scientific American," for coat- 
ing iron with copper, iron, or brass, by the electrotype process : — 

To make a Solution of Copper or Zinc. — Dissolve 8 ounces (troy) cyanide of potassium 
and 3 ounces of cyanide of copper or zinc in 1 gallon of rain or distilled water. These solu- 
tions to be used at about 160° F. with a compound battery of from 3 to 12 cells. 

To prepare a Solution of Brass. — Dissolve 1 lb. (troy) cyanide of potassium, 2 ounces 
of cyanide of copper, and 1 ounce of cyanide of zinc, in 1 gailon of rain or distilled water ; 
then add 2 ounces of muriate of ammonia. This solution is to be used at 160° F. for 
smooth work, and from 90° to 120°, with a compound battery of from 3 to 12 cells. See 

BRAZIL WOOD. The ibiripitanga, or Brazil wood, called, in Pernambuco, pao da 
rainha, (Queen's wood,) on account of its being a Government monopoly, is now rarely to be 
seen within many leagues of the coast, owing to the improvident manner in which it has 
been cut down by the Government agents, without any regard being paid to the size of the 
tree or its cultivation. It is not a lofty tree. At a short distance from the ground, innu- 
merable branches spring forth and extend in every direction in a straggling, irregular, and 
unpleasing manner. The leaves are small and not luxuriant ; the wood is very hard and 
heavy, takes a high polish, and sinks in water : the only valuable portion of it is the heart, 
as the outward coat of wood has not any peculiarity. The name of this wood is derived 
from brasas, a glowing fire or coal ; its botanical name is Ccesalpinia Bratilcto. The leaves 
are pinnated, the flower white and papilionaceous, growing in a pyramidal spike ; one spe- 

180 BEEAD. 

cies has flowers variegated with red. The branches are slender and full of small prickles. 
There are nine species. See Bell's " Geography." 

The species Brasileto, which is inferior to the crista, grows in great abundance in the 
West Indies. The demand for the Brasileto, a few years ago, was so great, owing to its 
being a little cheaper than the crista, that nearly the whole trees in the British possessions 
were cut down and sent home, which Mr. Bell very justly terms improvidence. It is not 
now so much used, and is consequently scarcer in the English market. 

The wood known in commerce as Pernambuco is most esteemed, and has the greatest 
quantity of coloring matter. It is hard, has a yellow color when newly cut, but turns red 
by exposure to the air. That kind termed Lima wood is the same in quality. Sapan wood 
grows in Japan, and in quality is next the two named above. It is not plentiful, but is 
much valued in the dyehouse for red of a certain tint ; it gives a very clear and superior 
color. The quantity of ash that these two qualities of wood contain is worthy of remark. 
Lima wood, as imported, gives the average of 2 - 7 per cent., while Sapan wood gives 1*5 
per cent. ; in both, the prevailing earth is lime. The quantity of moisture in the wood 
averages about 10 per cent. ; that in the ground wood in the market about 20 per cent. 

Peach wood, or Nicaragua, and sometimes termed Santa Martha wood, is inferior to the 
other two named, but is much used in the dyehouse, and, for many shades of red, is pre- 
ferred, although the coloring not so great. It gives a bright dye. The means of 
testing the quality of these woods by the dyer is similar to that describey for logwood, with 
the same recommendations and precautions. — Napier on Dyeing^ 

BREAD. One of the most important, if not altogether the most important, article of 
food, unquestionably, is bread ; and although rye, barley, oats, and other cereals are some- 
times used by the baker, reheat is the grain which is best fitted for the manufacture of that 
article, not only on account of the larger amount of gluten, or nitrogenous matter, which it 
contains, and than can be found in other edible grains, but also on account of the almost 
exact balance in which the nitrogenous and non-nitrogenous constituents exist in that cereal, 
and owing to which it is capable of ministering to all the requirements of the human frame, 
and of being assimilated at once and without effort by our organs, whence the name of 
"staff of life," which is often given to it, wheat being, like milk, a perfect food. 

Although gluten is one of the most important constituents of wheat, the nutritive power 
of its flour, and its value as a bread-making material, should not be altogether considered 
as dependent upon the quantity of gluten it may contain, even though it be of the best 
quality. Doubtless a high percentage of this material is desirable, but there are other 
considerations which must be taken into account ; for, in order to become available for 
making good bread, flour, in addition to being sound and genuine, must possess other qualities 
beyond containing merely a large amount of gluten. Thus, for example, the bit rouge glace 
d Auvergne, which contains hardly 45 per cent, of starch, and as much as 36 per cent, of 
gluten, though admirably adapted for the manufacture of macaroni, vermicelli, semolina, 
and other pdtes oVItalie, is totally unfit for making good bread ; the flour used for making 
best white loaves containing only from 10 to 18 per cent, of gluten, and from 60 to 70 per 
cent, of starch. 

Bread is obtained by baking a dough, previously fermented either by an admixture of 
yeast or leaven, or it is artificially rendered spongy by causing an acid, muriatic or tartaric, 
to react upon carbonate or bicarbonate of soda, or of ammonia, mixed in the doughy mass ; 
or, as in Dr. Dauglish's process, which will be described further on, by mixing the flour 
which has to be converted into dough, not with ordinary water, but with water strongly im- 
pregnated with carbonic acid. 

The conversion of flour into bread includes two distinct operations— namely, the prepa- 
ration of the dough, and the baking. The preparation of the dough, however, though 
reckoned as- one, consists, in fact, of three operations — namely, hydrating, kneading, and 

When the baker intends to make a batch of bread, his first care is, in technical lan- 
guage, to stir a ferment. This is done, in London, by boiling a few potatoes, in the pro- 
portion of 5 lbs. or 6 lbs. of potatoes per sack of flour, (which is the quantity we shall assume 
it is desired to convert into bread,) peeling them, mashing and straining them through a 
cullender, and adding thereto about three-quarters of a pailful of water, 2 or S lbs. of flour, 
and one quart of yeast. The water employed need not be warmed beforehand, for the heat 
of the potatoes is sufficient to impart a proper temperature (from 70° to 90° F.) to the 
liquid mass, which should be well stirred up with the hand into a smooth, thin, and homo- 
geneous paste, and then left at rest. 

In the course of an hour or two, the mass is seen to rise and fall, which swelling and 
heaving up is due to carbonic acid, generated by the fermentation induced in the mass, 
which may be thus left until wanted. In about three hours, this fermenting action will 
appear to be at an end, and when it has arrived at that stage, it is fit to be used. The fer- 
ment, however, may be left for six or seven hours and be still very good at the end of that 
time, but the common practice is to use it within four or five hours after its preparation. 

BEEAD. 181 

The nest operation consists in " setting the sponge.'" This consists in stirring the fer- 
ment well, adding thereto about two gallons of lukewarm water, and as much flour as will 
make, with the ferment, a rather stiff dough. This constitutes " the sponge." It is kept in 
a warm situation, and in the course of about an hour, fermentation again begins to make its 
appearance, the mass becomes distended or is heaved up by the carbonic acid produced, the 
escape of which is impeded by the toughness of the mass. This carbonic acid is the result 
of the fermentation induced under the influence of water, by the actirfn of the gluten upon 
the starch, a portion of which is converted thereby into sugar, and then into alcohol. A 
time, however, soon comes when the quantity of carbonic acid thus pent up becomes so great 
that it bursts through, and the sponge collapses or drops down. This is called the first 
sponge ; but as the fermentation is still going on, the carbonic acid soon causes the sponge 
to rise a^ain as before to nearly twice its volume, when the carbonic acid, bursting through 
the mass, causes it to fall a second time ; and this constitutes what the bakers call the second 
sponge. The rising and falling might then go on for twenty-four hours ; but as the alco- 
holic would pass into the acetous fermentation soon after the second rising, the baker always 
interferes after the second, and very frequently after the first sponge. The bread made 
from the first sponge is generally sweeter ; but, unless the best flour is used, and even then, 
the loaf that is made from it is smaller in size and more compact than that which is made 
with the second sponge. In hot weather, however, as there would be much danger of the 
bread turning sour, if the sponge were allowed to " take a second fall," the first sponge is 
frequently used. The next process consists in breaking the sponge, which is done by adding 
to it the necessary quantity of water and of salt, — the quantity of the latter substance vary- 
ing from £ lb. to f of a pound per bushel of flour ; that is, from 2£ lbs. to 3f lbs. per sack 
of flour, (new flour, or flour of inferior quality, always requires, at the very least, 3|- lbs. per 
sack, to bind it, that is to say, to render the dough sufficiently firm to support itself while 
fermenting.) Salt acts, to a great extent, like alum, though not so powerfully. As to the 
quantity of water to be used, it depends also a great deal on the quality of the flour, the 
best quality absorbing most ; though, as we shall have occasion to remark, the baker too 
often contrives to force and keep' into bread made from inferior flour, by a process called 
under-baking, the same amount of water as is normally taken up by that of the best quality. 
Generally speaking, and with flour of good average quality, the amount of water is such that 
the diluted sponge forms about 14 gallons of liquid. The whole mass is then torn to pieces 
by the hand, so as to break any lumps that there maybe, and mix it up thoroughly with the 
water. This being done, the rest of the sack of flour is gradually added and kneaded into a 
dough of the proper consistency. . This kneading of the dough may be said to be one of 
the most important processes of the manufacture, since it not only produces a more com- 
plete hydration of the flour, but, by imprisoning a certain quantity of air within the dough, 
and forcibly bringing into closer contact the molecules of the yeast or leaven with the sugar 
of the flour, and also with a portion of the starch, the fermentation or rising of the whole 
mass, on which the sponginess of the loaf and its digestibility subsequently depend, is se- 
cured. When, by forcing the hand into the dough, the baker sees that, on withdrawing it, 
none of the dough adheres to it, he knows that the kneading is completed. The dough is 
then allowed to remain in the trough for about an hour and a half or two hours, if brewers^ 
or German yeast have been employed in making the sponge ; if, on the contrary, patent 
yeast or hop yeast have been used, three or even four hours may be required for the dough 
to rise up, or, as in technical language, to give proof. When the dough is sufficiently 
"proofed," it is weighed off into lumps, shaped into the proper forms, of 4 lbs. 4 oz. each, 
and exposed for about one hour in an oven to a temperature of about S'lO" F., the heat 
gradually falling to 430 or 420° F. The yield after baking is 94 quartern (not 4-lb.) loaves, 
or from 90 to 92 really 4-lb. loaves, as largcagain as they were when put into the oven in 
the shape of dough. 

The manner in which yeast acts upon the flour is, as yet, an unsolved mystery, or, at 
any rate an, as yet, unsatisfactorily explained action ; for the term " catalysis," which has 
sometimes been applied to it, explains absolutely nothing. 

A yeast, or fermenting material, may be prepared in various ways-, but only three kinds 
of yeast are used by bakers: namely, brewers' yeast, or barm, — German yeast, and patent, 
or hop yeast. 

The most active of these ferments is the first, or brewers' yeast ; it is, as is well known, 
a frothy, thickish material, of a brownish or drab color, which, when recent, is in a state of 
slight effervescence, exhales a sour characteristic odor, and has an acid reaction. 

When viewed through the microscope, it is seen to consist of small globules of various 
size, generally egg-shaped. They were first described by M. Desmayieres. 

The best, and in fact the only brewers' yeast used in bread-making, is that from the ale 
breweries ; porter yeast is unavailable for the purpose, because it imparts to the bread a dis- 
agreeable bitter taste. 

German yeast is very extensively used by bakers. It is a pasty but easily crumbled 
mass, of an agreeable fruity odor, and of a dingy white color. German yeast will remain 



good for a few weeks, if kept in a cool place. When in good condition, it is an excellent 
article ; but samples of it are occasionally seized on bakers' premises, of a darker color vis- 
cid, and emitting an offensive cheesy odor : such German yeast, being in a putrefied state, 
is, of course, objectionable. 

The so-called '■'•patent yeast" is the cheapest and at the same time the weakest of these 
ferments ; very good bread, however, is made with it, and it is most extensively used by 
bakers. It is made either with or without hops : when with hops, it is called hop yeast, and 
is nothing more than a decoction of hops to which malt is added while in a scalding hot 
state ; when the liquor has fallen to a blood heat, a certain quantity of brewers' or German 
yeast is thoroughly mixed with it, and the whole is left at rest. The use of the hops is in- 
tended to diminish the tendency of this solution to become acid. 

Potato yeast is a kind of "patent yeast " in general use. 

The theory of panification is not difficult of comprehension. " The flour," says Dr. Ure, 
" owes this valuable quality to the gluten, which it contains in greater abundance than any 
of the other cerealia, (kinds of corn.) This substance does not constitute, as has been here- 
tofore imagined, the membranes of the tissue of the perisperm of the wheat ; but is inclosed 
in cells of that tissue under the epidermic coats, even to the centre of the grain. In this 
respect the gluten lies in a situation analogous to that of the starch, and of most of the im- 
mediate principles of the vegetables. The other immediate principles which play a part in 
panification are particularly the starch and the sugar ; and they all operate as follows : — 

" The diffusion of the flour through the water hydrates the starch, and dissolves the 
sugar, the albumen, and some other soluble matters. The kneading of the dough, by com- 
pleting these reactions through a more intimate union, favors also the fermentation of the 
sugar, by bringing its particles into close contact with those of the leaven or yeast; and the 
drawing out and laminating the dough softens and stratifies it, introducing at the same time 
oxygen to aid the fermentation. The dough, when distributed and formed into loaves, is 
kept some time in a gentle warmth, in the folds of the cloth, pans, &c, a circumstance pro- 
pitious to the development of their volume by fermentation. The dimensions of all the 
lumps of dough now gradually enlarge, from the disengagement of carbonic acid in the de- 
composition of the sugar, which gas is imprisoned by the glutinous paste. Were these phe- 
nomena to continue too long, the dough would become too vesicular ; they must, therefore, 
be stopped at the proper point of sponginess, . by placing the loaf lumps in the oven. 
Though this causes a sudden expansion of the enclosed gaseous globules, it puts an end to 
the fermentation, and to their growth ; as also evaporates a portion of the water. 

" The fermentation of a small dose of sugar is, therefore, essential to true bread-making ; 
but the quantity actually fermented is so small as to be almost inappreciable. It seems 
probable that in well-made dough the whole carbonic acid that is generated remains in it, 
amounting to one-half the volume of the loaf itself at its baking temperature, or 212° F. It 
thence results that less than one-hundredth part of the weight of the flour is all the sugar 
requisite to produce well-raised bread. 

" Although the rising of the dough is determined by the carbonic acid resulting from 
the decomposition of the sugar, produced by the reaction of the gluten on hydrated or moist 
flour, considering that the quantity of sugar necessary to produce fermentation does not 
amount, probably, to more than one-hundredth part of the weight of the flour employed, 
and perhaps to even considerably less than that, — the saving and economy which is said to 
accrue to the consumer from the use of unfermented bread (which is bread in which the ac- 
tion of yeast is replaced by an artificial evolution of carbonic acid, by decomposing bicar- 
bonate of soda with muriatic acid, as we said before) is therefore much below what it has 
been estimated (25 per cent. !) by some writers ; and it is certainly very far from compen- 
sating for the various and serious drawbacks which are peculiar to that kind of bread, one 
of which — and it is not the least — is its indigestibility, notwithstanding all that may have 
been said to the contrary. 

" In a pamphlet entitled, ' Instructions for making Unfermented Bread, by a Physician,' 
published in 1846, the formula recommended for bread made of wheat meal is as follows : 
Wheat meal - - - - S lbs. avoirdupois: 
Bicarbonate of soda - - 4-J- drachms troy. 
Hydrochloric acid 5 fluid drachms and 25 minims, or drops. 

Water 30 fluid ounces. 

Salt - - - - - ■§■ of an ounce troy. 

" Bread made in this manner," says the author, " contains nothing but flour, common 
salt, and water. It has an agreeable, natural taste, keeps much longer than common bread, 
is much more digestible, and much less disposed to turn acid," &c. 

Liebig, in his " Letters on Chemistry," very judiciously remarks, " that the intimate 
mixture of the saliva with the bread, whilst masticating it, is a condition which is favorable 
to the rapid digestion of the starch ; wherefore the porous state of the flour in fermented 
bread accelerates its digestion." 

Now, it is a fact, which can readily be ascertained by any one, that unfermented bread 

BEEAD. 183 

is permeated by fluids with difficulty. It will not absorb water, hence its heavy and clammy 
feel ; nor saliva, hence its iudigestibleness ; nor milk, nor butter. Unfermented bread will 
neither make soup, nor toast, nor poultice. When a slice of ordinary bread is held before 
a bright fire, a portion of the moisture of the bread, as the latter becomes scorched, is con- 
verted into steam, which penetrates the interior of the mass, and imparts to it the spongi- 
ness so well known in a toast properly made ; but if a piece of unfermented bread be treated 
in the same manner, the steam produced by the moisture, not being able to penetrate the 
unabsorbent mass, evaporates, and the result is an uninviting slice, toasted, but hard inside 
and out, and into which butter penetrates about to the same extent as it would a wooden 
slab of the same dimensions. 

" Fermentation," says Liebig, " is not only the best and simplest, but likewise the most 
economical way of imparting porosity to bread ; and besides, chemists, generally speaking, 
should never recommend the use of chemicals for culinary preparations, for chemicals are 
seldom met with in commerce in a state of purity. Thus, for example, the muriatic acid 
which it has been proposed to mix with carbonate of soda in bread is alicays very impure, 
and very often contains arsenic. Chemists never employ such an acid in operations which 
are certainly less important than the one just mentioned, without having first purified it." 

In order to remove this ground of objection, tartaric acid has been recommended instead 
of muriatic acid for the purpose of decomposing the carbonate of soda ; but in that way an- 
other unsafe compound is introduced, since the result of the reaction is tartrate of soda, a 
diuretic aperient, and consequently very objectionable salt, for it is impossible to say what 
mischief the continuous ingestion of such a substance may eventually produce ; and what- 
ever may be the divergence of opinion, — if there be such a divergence, — as to whether or 
not the constant use of an aperient, however mild, may be detrimental to health, it surely 
must be admitted that, at any rate, it is better to eschew such, to say the least of it, suspi- 
cious materials ; and that, at any rate, if deprecating their use be an error, it is an error on 
the safe side ; — after all, a bakehouse is not a chemical laboratory. 

Before leaving this question of unfermented bread, we must not omit to speak of a re- 
markable process invented by Dr. Dauglish, and which has lately excited some attention. 
Without discussing the value of the idea which is said to have led Dr. Dauglish to invent 
the process in question, we shall simply describe Dr. Dauglish's method of making bread, 
and give his own version of its benefits : — 

" Taking advantage of the well-known capacity of water for absorbing carbonic acid, 
whatever its density, in quantities equal to its own bulk, I first prepare the water which is 
to be used in forming the dough, by placing it in a strong vessel capable of bearing a high 
pressure, and forcing carbonic acid into it to the extent of say ten or twelve atmospheres," 
(about 150 to 180 lbs. per square inch ;) " this the water absorbs without any appreciable 
increase in its bulk. The water so prepared will of course retain the carbonic acid in solu- 
tion so long as it is retained in a close vessel under the same pressure. I therefore place 
the four and salt, of which the dough is to be formed, also in a close vessel capable of bear- 
ing a high pressure. Within this vessel, which is of a spheroidal form, a simply-constructed 
kneading apparatus is fitted, worked from without through a closely-packed stuffing box. 
Into this vessel I force an equal pressure to that which is maintained in the aerated water- 
vessel ; and then, by means of a pipe connecting the two vessels, I draw the water into the 
flour, and set the kneading apparatus to work at the same time. By this arrangement the 
water acts simply as limpid water among the flour, the flour and water are mixed and 
kneaded together into paste, and to inch an extent as shall give it the necessary tenacity. 
After this is accomplished the pressure is released, the gas escapes from the water, and in 
doing so raises the dough in the most beautiful and expeditious manner. It will be quite 
unnecessary for me to point out how perfect must be the mechanical structure that results 
from this method of raising dough. In the first place, the mixing and kneading of the flour 
and water together, before any vesicular property is imparted to the mass, render the most 
complete incorporation of the flour and water a matter of very easy accomplishment ; and 
this being secured, it is evident that the gas which forms the vesicle, or sponge, when it is 
released, mu^t be dispersed through the mass in a manner which no other method — fermen- 
tation not excepted — could accomplish. But besides the advantages of kneading the dough 
before the vesicle is formed, in the manner above mentioned, there is another, and perhaps 
a more important one, from what it is likely to effect by giving scope to the introduction 
of new materials into bread-making, — and that is, I find that powerful machine-kneading, 
continued for several minutes, has the effect of imparting to the dough tenacity or tough- 
ness. In Messrs. Carr and Co.'s machine, at Carlisle, we have kneaded some wheaten dough 
for half an hour, and the result has been that the dough has been so tough that it resembled 
birdlime, and it was with difficulty pulled to pieces with the hand. Other materials, such 
as rye, barley, &c, are affected in the same manner. So that by thus kneading, I am able 
to impart to dough made from materials which otherwise would not make light bread, from 
their wanting that quality in their gluten which is capable of holding or retaining, the same 
degree of lightness which no other method is capable of effecting. And I am sanguine of 



being able to make from rye, barley, oatmeal, and other wholesome and nutritious sub- 
stances, bread as light and sweet as the finest wheaten bread. One reason why my process 
makes a bread so different from all other processes where fermentation is not followed, is, 
that I am enabled to knead the bread to any extent without spoiling its vesicular propertv ; 
whilst all other unfermented breads are merely mixed, not kneaded. The property thus 
imparted to my bread by knettding, renders it less dependent on being placed immediately 
in the oven. It certaintly cannot gain by being allowed to stand after the dough is formed, 
but it bears well the necessary standing and waiting required for preparing the loaves for 

" There is one point which requires care in my process, and that is, the baking, — as the 
dough is excessively cold ; first, because cold water is used in the process ; and next, be- 
cause of its sudden expansion on rising. It is thus placed in the oven some 40° Fahr. in 
temperature lower than the ordinary fermented bread. This, together with its slow spring- 
ing until it reaches the boiling point, renders it essential that the top crust shall not be 
formed until the very last moment. Thus, I have been obliged to have ovens constructed 
which are heated through the bottom, and are furnished with the means of regulating the 
heat of the top, so that the bread is cooked through the bottom ; and, just at the last, the 
top heat is put on and the top crust formed. 

" With regard to the gain effected by saving the loss by fermentation, I may state what 
must be evident, that the weight of the dough is always exactly the sum of the weight of 
flour, water, and salt put into the mixing vessel ; and that, in all our experiments at Carlisle, 
we invariably made 118 loaves from the same weight of flour which by fermentation made 
only 105 and 106. Our advantage in gain over fermentation can only be equal to the loss 
by fermentation. As there_ has been considerable difference of opinion among men of 
science with respect to the amount of this loss, — some stating it to be as high as 17-J per 
cent, and others so low as 1 per cent., — I will here say a few words on the subject. Those 
who have stated the loss to be as high as 17-J- per cent, have, in support of their position, 
pointed to the extra yield from the same flour of bread when made by non-fermentation, 
compared with that made by fermentation. Whilst those who have opposed this assertion, 
and stated the loss to be but 1 per cent, or little more, have declared the gain in weight to 
be simply a gain of extra water, and have based their calculations of loss on the destruction 
of material caused by the generation of the necessary quantity of carbonic acid to render the 
bread light. Starting then with the assumption that light bread contains in bulk half solid 
matter and half aeriform, they have calculated that this quantity of aeriform matter is ob- 
tained by a destruction of but one per cent, of solid material. In this calculation the loss 
of carbonic acid, by its escape through the mass of dough during the process of fermenta- 
tion and manufacture, does not appear to have been taken into account. All who have 
been in any way practically connected with bakeries, well know how large this lose is, and 
how important it is that it should be taken into account, that our calculations may be 

" One of the strongest proofs that the escape of gas through ordinary soft bread dough 
is very large, arises from the fact that when biscuit dough, in which there is a mixture of 
fatty matter, is prepared by my process, about half the quantity of gas only is needed to 
obtain an equal amount of liglitness with dough that is made of flour and water only, the 
fatty matter acting to prevent the escape of gas from the dough. Other matters will ope- 
rate in a similar manner — boiled flour, for instance, added in small quantities. But the as- 
sumption that light bread is only half aeriform matter is altogether erroneous. Never before 
has there been so complete a method of testing what proportion the aeriform bears to the 
solid in light bread as that which my process affords. The mixing vessel at Messrs. Carr and 
Co.'s works, Carlisle, has an internal capacity of 10 bushels. When 3-| bushels of flour are 
put into this vessel, and formed into spongy bread dough, by my process, it is quite full. 
And when flour is mixed with water into paste, the paste"measures rather less than half the 
bulk of the original dry flour. This will therefore represent about If bushels of solid mat- 
ter expanded into 10 bushels of spongy dough, showing in the dough nearly 5 parts aeri- 
form to 1 solid ; and in all instances, if the baking of this dough has not been accomplished 
so as to secure the loaves to ' spring ' to at least double their size in the oven, they have 
always come out heavy bread when compared with the ordinary fermented loaves. This 
gives the relative proportion of aeriform to solid in light bread at least as 10 to 1, and at 
once raises the loss by fermentation from 1 to 10 per cent., without taking into account the 
loss of gas by its passage through the mass of dough. 

" Of the quality and properties of the bread manufactured by my process, there will 
shortly be ample means of judging. I may be allowed, however, here to state, what will be 
evident to all, that the absence of every thing but flour, water, and salt, must render it 
absolutely pure ; — that its sweetness cannot be equalled except by bread to which sweet 
materials are superadded ; — that, unlike all other unfermented bread, it makes excellent 
toast ; and, on account of its high absorbent power, it makes the most delicious sop pud- 
dings, &c, and also excellent poultice. Sop pudding and poultice made from this bread, 

BEEAD. 185 

however, differ somewhat from those made from fermented bread, in being somewhat richer 
or more glutinous. This arises from the fact of the gluten not having been changed, or 
rendered "soluble, in the manner caused by fermentation ; but that this is a good quality 
rather than a bad one, is evident from the fact, that the richer and purer fermented bread is, 
the more glutinous are the sop, &c, made from it ; and the poorer and more adulterated 
with alum"it is, the freer the sop, &c, are of this quality." 

Such, then, is Dr. Dauglish's plan, and it is impossible to deny that it possesses great 

From the fact that, in all his experiments at Carlisle, Dr. Dauglish invariably made 118 
loaves from the same weight of flour which, by fermentation, made only 105 or 106, to 
argue that the gain over fermentation can only be equal to the loss by fermentation, is to 
draw a somewhat hasty conclusion ; for the gain may be, and is probably due, not to the 
preservation in the bread of what is generally lost by fermentation, but simply to a reten- 
tion of water. 

It is of course certain that the production of the porosity required in bread produced by 
the carbonic acid and alcohol evolved by fermentation, entails the loss of a portion of the 
valuable constituents of the flour, but the amount of that loss should not be estimated, I 
think, from the proportions which the aeriform bear to the solid matter of the loaf after it 
is baked. 

In effect, the fermentation induced in bread differs from that produced at the distillery, 
inasmuch" as, instead of the fermenting material being sheltered from the air by an atmos- 
phere of carbonic acid, the dough is on the contrary thoroughly permeated by, and retains a 
considerable quantity of atmospheric air introduced into it by the kneading process, and 
owing to the presence of which, in fact, the acetous fermentation is carried on to a certain 
extent, within the dough, simultaneously with the alcoholic fermentations, so that even the 
10 parts of aeriform matter to 1 of solid matter in a quartern loaf, are not altogether car- 
bonic acid resulting from the fermentation, but are carbonic acid from that source mixed 
with the atmospheric air with which the dough is permeated. On the other hand, the aeri- 
form matter thus imprisoned in the dough, expands to at least twice its volume when ex- 
posed to the temperature of the oven, and accordingly the bread after baking becomes as 
bulky again as the dough from which it was made, and this doubling of the volume being 
due to the expansion of the gases, and not to the fermentation, bears no proportion what- 
ever to the amount of the sugar of the flour employed in the production of the alcohol and 
carbonic acid evolved. Moreover, as a quartern loaf, for example, measures about 9 inches 
by 6 - 5 inches by 5 inches, making a total of about 292 cubic inches, if we take nine-tenths 
of that to be aeriform matter, we have 262'8 inches as the aeriform cubic contents of the 
quartern loaf. 

It is ascertained beyond doubt by numerous experiments, that genuine, properly manu- 
factured new bread contains, on an average, 42-5 per cent, of water, and 57 - 5 of flour, and 
consequently a quartern loaf weighing really four pounds, would consist of 11,900 grains 
of water and 16,000 grains of solid matter, 422'5 grains of which are salt and inorganic 
matter ; the rest, 156*77"5 grains, being starch and gluten. Now a quartern loaf measuring 
about 9 x 6'5 x 5 inches, gives a total of 292 cubic inches. Assuming, with Dr. Dauglish, 
nine-tenths of that to be aeriform matter, we have 262'8- inches as the aeriform cubic con- 
tents of a quartern loaf, but as the gases expanded in the dough to double their volume 
during its being baked into a loaf, we must divide by 2 the 262-8 inches above alluded to, 
which gives 13T4 as the number of cubic inches of aeriform matter contained in the dough 
before it went into the oven. Again, assuming with Dr. Dauglish that these 131"4 cubic 
inches consist altogether of carbonic acid resulting from the fermentation of the flour, they 
would represent in weight only 62 grains of that gas, and as 1 equivalent = 198 of sugar 
produces 4 equivalents = 88 of carbonic acid, it follows that, at most, about 140 grains of 
sugar or solid matter out of the 15677-5 of flour in the quartern loaf would have disappeared, 
which loss is less than 1 per cent., from which, however, it is necessary to make a consider- 
able reduction, since a large quantity of air is mixed with that carbonic acid, and expanded 
with it in the oven. Unless, therefore, it can be satisfactorily proved that the unfermented 
bread manufactured by Dr. Dauglish's process is more nutritious, weight for weight, or more 
digestible, or possesses qualities which fermented bread has not, or is sold at a reduced price 
proportionate to the quantity of water thus locked up and passed off for bread, the benefits 
and advantages will be all on the manufacturer's side, but the purchasers of the unfermented 
bread will make but a poor bargain of it. 

Of all the operations connected with the manufacture of bread, the most laborious, and 
that which calls most loudly for reform, is that of kneading. The process is usually carried 
on in some dark corner of a cellar, where the temperature is seldom less than 60° F., and 
frequently more ; by a man, stripped naked down to the waist, and painfully engaged in 
extricating his fingers from a gluey mass into which he furiously plunges alternately his 
clenched fists, heavily breathing as he, struggling, repeatedly lifts up the bulky and tena- 



cious mass in his powerful arms, and with effort flings it down again with a groan fetched 
from the innermost recesses of his chest, and which almost sounds like an imprecation. 

We know, on very good and unexceptionable authority, that a certain large bakery on 
the borders of a canal, actually pumped the water necessary for making the dough directly 
and at once from the canal, and this from a point exactly contiguous to the discharging of 
the cesspool of that bakery ! And let us not imagine that this is a solitary instance of hor- 
rible filth. The following memoranda, recorded by Dr. Wm. A. Guy, in his admirable lec- 
ture on " The Evils of Night-work and Long Hours of Labor," delivered on Thursday, July 
6, 1848, at the Mechanics' Institution, Southampton Buildings, will serve to illustrate the 
condition of the bakehouses : — 

1. Underground, two ovens, no daylight, no ventilation, very hot and sulphurous. 

2. Underground, no daylight, two ovens, very hot and sulphurous, low ceiling, no ven- 

tilation but what comes from the doors. Very large business. 

3. Underground, no daylight, often flooded, very bad smells, overrun with rats, no ven- 


After mentioning several other establishments in the same, or even in a worse condition, 
than those just enumerated, Dr. Guy adds: — ■ 

" The statements comprised in the foregoing memoranda are in conformity with my own 
observations. Many of the basements in which the business of baking is carried on are cer- 
tainly in a state to require the assistance of the Commissioners of Sewers, and to invite the 
attention of the promoters of sanitary reform." 

If we reflect that bread, like all porous substances, readily absorbs the air that surrounds 
it, and that, even under the best conditions, it should never, on that account, be kept in 
confined places, what must be the state of the bread manufactured in such a villanous man- 
ner, and with a slovenliness greater than it is possible for our imagination to conceive ? 
What can prove better the necessity of Government supervision than such a fact ? The 
heart sickens at the revolting thought, but, after all, there is really but little difference be- 
tween the particular case of the bakery on the border of a canal above alluded to, and the 
mode of kneading generally pursued, and to which we daily submit. 

In the sitting of the Institute of France, on the 23d of January, 1850, the late M. Arago 
presented and recommended to the Academie the kneading and baking apparatus of M. 
Rolland, then a humble baker of the 12th Arrondissement, which, it would appear, fulfils 
all the conditions of perfect kneading and baking. 

"The kneading machine (petrin meccmique) of M. Rolland," says Arago, "is extremely 
simple, and can be easily worked, when under a full charge, by a young man from 15 to 20 
years old : the necessity for horse labor or steam power may thus be obviated. The machine 
(jigs. "71 to 74) consists of a horizontal axis traversing a trough containing all the dough 
requisite for one baking batch, and upon which axis a system of curvilinear blades, alter- 
nately long and short, are placed in such a manner that, while revolving, they describe two 
quarters of cylindrical surfaces with contrary curves, so that the convexity of one of these 
surfaces, and the concavity of the other, is turned towards the bottom of the trough. The 
axis has a fly-wheel, and is set in motion by two small cog-wheels connected with the han- 
dle, as represented in the following figures : — 



inn fuiuiun 





The action of the kneading machine is both easy and efficacious. In 20, and, if neces- 
sary, in 15, or even 10 minutes, a sack of flour may be converted into a perfectly homoge- 
neous and aerated dough, without either lumps or clods, and altogether superior to any 
dough that could be obtained by manual kneading. The time required in kneading varies 
according to the greater or less density of dough required ; and the quantity of dough manu- 
factured in that space of time varies, of course, also with the dimensions of the kneading- 
trough ; for instance, in the trough provided with 16 blades, one sack and a half of flour 
can be kneaded at once ; in that of 14 blades, one sack, and in that of 12 blades, two-thirds 
of a sack. 

M. Holland gives the following instructions for the use of the machine, in order to im- 
part to the dough the qualities produced by the operations known in France under the names 
of frasage, contrefrasage, and soufflage, which we shall presently describe, and to which the 
bread manufactured in that country mainly owes, in the words of Dr. Ure, " a flavor, color, 
and texture, never yet equalled in London." 

The necessary quantity of leaven or yeast is first diluted with the proper quantity of 
water, as described before ; and in order to effect the mixture, the crank should be made to 
perform 50 revolutions alternately from right to left. — Frasage is the first mixture of the 
flour with the water. The flour is simply poured into the kneading-trough, or, better still, 
when convenience permits it, it is let down from a room above through a linen hose, which 
may be shut by folding it up at the extremity. 

Three-fourths only of the flour should at first be put into the trough ; the first revolu- 
tions of the kneader should be rather rapid, but during the remainder of the operation the 
turning should be at the rate of about two or three revolutions a minute, according to the 
density of the dough to be prepared. The dough thereby having time to be well drawn out 
between the blades, and to drop to the bottom of the trough. From 24 to 36 revolutions 
of the crank will generally be sufficient ; but in order to obtain the dough in the condition 
which the frasage would give it in the usual way, it will be necessary to make about 250 
revolutions of the crank alternately from right to left, about the same number of turns. 

Contrefrasage is the completion of the process of mixing ; and, in order to perform that 
operation, the last fourth part of the flour must now be added, the crank turned 150 revol- 
utions, to wit : 75 turns rather slowly, alternately from right to left, and the remainder at 
the rate of speed above mentioned. 

The operation of soufflage consists in introducing and retaining air in the paste. To 
effect this, the kneader should be made to perform, during nearly the whole time occupied 
in the operation, an almost continual motion backwards and forwards, by which means the 
dough is shifted from place to place ; five revolutions being made to the right, and five to 
the left, alternately, taking care to accelerate the speed a little at the moment of reversing 
the direction of the revolving blades. 

All these operations are accomplished in twenty or twenty-five minutes. 

Of course, the reader should not imagine that these numbers must be strictly followed ; 
they are given merely as a guide indicative of the modus operandi. 

The kneading being completed, the dough is left to rest for some time, and then divided 
into lumps, of a proper weight, for each loaf. The workman takes one of these lumps in 
each hand, rolls them out, dusts them over with a little flour, and puts each of them sepa- 
rate in its panneton ; he proceeds with the rest of the dough in the same maimer, and 



leaves all the lumps to swell, which, if the flour have been of good quality, will take place 
at a uniform rate. They are then fit for baking, which operation will be described presently. 

The Hot-water Oven Biscuit-baking Company possesses also a good machine with which 
1 cwt. of biscuit dough, or 2 cwts. of bread dough, can be perfectly kneaded in 10 minutes. 
The machine is an American invention, and of extraordinary simplicity, for it is in reality 
nothing more than a large corkscrew, working in a cylinder, by means of which the dough is 
triturated, squeezed, pressed, torn, hacked, and finally agglomerated as it is pushed along. 
The dough, as it issues from that machine, can at once be shaped into loaves of suitable size 
and dimensions. A machine capable of doing the amount of work alluded to does not come 
to more than from £6 to £7 ; the other forms of kneading machines are likewise inexpen- 
sive, so that, in addition to the economy of time which they realize, there does not seem to 
be any excuse for retaining the abomination of manual kneading. 

Among superior and very desirable apparatus for bread-making, there are at any rate 
three which fulfil the desiderata above alluded to, in the most complete and economical 
manner. One of them is M. Mouchot's aerothermal bakery ; the second is A. M. Perkins' 
hot-water oven ; the third is Rolland's hot-air oven, with revolving floors : all three are ex- 

Perkins' hot-water oven is an adaptation of that distinguished engineers' stove, which, 
as is well known, is a mode of heating by means of pipes full of water, and hermetically 
closed ; but with a sufficient space for the expansion of the water in the pipes. As a means 
of warming buildings, the invention has already produced the very beneficial effects which 
have gained for it an extensive patronage. There is no doubt but that this novel applica- 
tion entitles the inventor to the warmest thanks of the public. The following figure (75) 
represents one of these ovens, a, stove ; b, coil of iron pipe placed in, the stove ; c c, 
flowpipe ; d, expansive tube ; e, oven charged with loaves, and surrounded with the hot- 
water pipes ; f, return hot-water pipe ; g, door of the oven ; h, flue for the escape of the 
vapors in the oven ; i, rigid bar of iron supporting the regulating box ; j, j, regulating box 
containing three small levers ; k, nut adjusted so that if temperature of the hot-water pipe 
is increased beyond the adjusted point, its elongation causes the nut to bear upon the levers 
in the box, j, which levers, lifting the straight rod l, shut the damper m of the stove ; n is 
an index indicating the temperature of the hot-water pipes. 


The oven is first built in the ordinary manner of sound brickwork, made very thick in 
order to retain the heat. Then the top and bottom of the internal surfaces are lined with 
wrought-iron pipes of one inch external diameter, and five-eighths of an inch internal diam- 
eter, and their surface amounts, in the aggregate, to the whole surface of the oven. These 
pipes arc then connected to a coil in a furnace outside the oven. The coil having such a 
relative proportion of surface to that which is in the oven, that the pipes may be raised to a 
temperature of 550° F., and no more. This fixed and uniform temperature is maintained 
by a self-regulating adjustment peculiar to this furnace, which works with great precision, 
and which cannot get out of order, since it depends upon the expansion of the upper as- 
cending pipe close to the furnace acting upon three levers connected with the damper which 
regulates the draught. The movable nut at the bottom of that expanding pipe being 
adjusted to the requisite temperature, that precise temperature is uniformly retained. The 



smallest fluctuation in the heat of the water which circulates in the pipes instantly sets .the 
levers in motion, and the expansion of one-thirty-sixth part of an inch is sufficient to close 
the damper. 

It will be observed, that if the pipe be heated to 550' F., the brickwork will soon attain 
the same temperature, or nearly so, and accordingly the oven will thus possess double the 
amount of the heating surface of ordinary ovens applicable to baking. The baking temper- 
ature of the oven is from 420° to 450° F., which is ascertained by a thermometer with 
which the oven is provided. 

With respect to Eolland's oven, Messieurs Boussingault, Payen, and Poncelet, in their 
report to the Institute of France ; Gaultier de Glaubry, in a report made in the name of the 
Committee of Chemical Arts to the Societe d'Encouragement ; and the late M. Arago, 
represented that oven as successfully meeting all the conditions of salubrity, cleanliness, and 
hvo-iene. Wood, coals, and ashes, are likewise banished from it, and neither smoke nor 
the heated air of the furnace can find access to it. As in Perkins', the furnace is placed at 
a distance from the mouth of the oven, but, instead of conveying the heat by pipes, as in 
the hot-water oven, it is the smoke and hot air of the furnace which, circulating through 
fan-shaped flues, ramifying under the floor, and spreading over the roof of the oven, impart 
to it the requisite temperature. The floor of the oven, on which the loaves are deposited, 
consists of glazed tiles, and it can thus be kept perfectly clean. The distinctive character 
of M. Holland's oven, however, is that the glazed tiles just spoken of rest upon a revolving 
platform, which the workman gradually, <sr from time to time, moves round by means of a 
small handle, and without effort. 

Figures 76 to 85 represent the construction and appearance of M. Eolland's oven' on a 
reduced scale. 

76. Front elevation. 

77. Vertical section through the axis 

of the fire-grate. 

78. Ditto, ditto. 

79. Elevation of one of the vertical flues. 

80. Suspension of the floors. 

81. Plan of the first floor. 

82. Plan of the sole. 

83. Plan of the second floor. 

84. Plan of the fire-grate and flues. 

85. Plan of the portion under ground. 


When the oven has to be charged, the workman deposits the first loaves, by means of a 
short peel, upon that part of the revolving platform which lies before the mouth of the oven, 
and when that portion is filled, he gives a turn with the handle, and proceeds to put the 
loaves in the fresh space thus presented before him, and so on, until the whole is fitted up. 
The door is then closed through an opening covered with glass, and reserved in the wall of 
the oven, which is lighted up with a jet of gas, or by opening the door from time to time, 
the progress of the baking may be watched ; if it appears too rapid on one point, or too 
slow on another, the journeyman can, by means of the handle, bring the loaves successively 
to the hottest part of the oven, and vice versa., as occasion may require. The oven is pro- 
vided with a thermometer, and, in an experiment witnessed, the temperature indicated 
210° C. = 410° F., the baking of a full charge was completed in one hour and ten minutes, 
and the loaves of the same kind were so even in point of size and color that they could not 
be distinguished from each other. 

The top of the oven is provided with a pan for the purpose of heating the water neces- 
sary for the preparation of the dough, by means of the heat which in all other plans (Mou- 
chot's excepted) is lost. The workman should take care to keep always some water in that 



pan, for otherwise the leaden pipe would melt and occasion dangerous leaks. For this and 
other reasons, the safest plan, however, would be to replace this leaden pipe by an iron 
one. The said pan should be frequently scoured, for, if neglected, the water will become 


rusty, and spoil the color of the bread. Bread-baking may be considered as consisting of 
four operations — namely, heating the oven, putting the dough into the oven, baking, and 





— ^W— 84 



taking the loaves out of the oven. The general directions given by M. Rolland for each of 
these operations are as follows : — 

In order to obtain a proper heat, and one that may be easily managed, it is necessary to 
charge the furnace moderately and often, and to keep it in a uniform state. 

When the fire is kindled, the door should be kept perfectly closed, in order to compel 
the current of air necessary to the combustion to pass through the grate, and thence through 
the flues under and the dome over the oven. If, on the contrary, the furnace door were 
left ajar, the cold air from without would rapidly pass over the coals, without becoming 


properly heated, and, passing in that condition into the flues, would fail in raising it to the 
proper temperature. In order that the flame and heated products of the combustion may 
pass through all the flues, it is, of course, necessary to keep them clear by introducing into 
them once a month a brush made of wire, or whalebone, or those which are now generally 
used for sweeping the tubes of marine tubular* boilers, and the best of which are those 
patented and manufactured by Messrs. Moriarty, of Greenwich, or How, of London. The 
vertical flues which are built in the masonry are cleared from without or from the pit, ac- 
cording to the nature of the plan adopted in building the oven. These flues need not be 
cleaned more often than about once in three months. 

Sweeping between the floors should be performed about every fortnight. 

In case of accident or injury to the thermometers, the following directions, which, in- 
deed, apply to all ovens, may enable the baker to judge of the temperature of his oven : — 
If, on throwing a few pinches of flour on the tiles of the oven, it remains white after the 
lapse of a few seconds, the temperature is too low ; if, on the contrary, the flour assumes a 
deep brown color, the temperature is too high ; if the flour turns yellowish, or looks slightly 
scorched, the temperature is right. 

The baking in Rolland's oven takes place at a temperature varying from 410° to 432° 
F., according to the nature and size of the articles intended to be baked. During the baking, 
the revolving floor is turned every ten or twelve minutes, so that, the loaves not remaining 
in the same place, the baking becomes equal throughout. 



As to the hot-water oven, two establishments only have as yet adopted it in England ; 
one of them is the " Hot-water Oven Biscuit-baking Company," on whose premises fancy 
biscuits only are baked ; the second establishment is that of a baker of the name of Neville, 
carrying on his business in London. With respect to M. Mouchot's system, it is not even 
known in tins country, otherwise than by having been alluded to in one or two techno- 
logical publications or dictionaries. 

The quantity of bread which can be made from a sack of flour depends to a great extent 
upon the quantity of gluten that the flour of which it is made contains, but the wheat which 
contains a large proportion of nitrogenous matter, does not yield so white a flour as those 
which are poorer. From a great number of determinations, it is found that the amount of 
gluten contained in the flour to make best white bread ranges from 10 to 18 per cent., that 
of the starch being from 63 to 70 per cent, the ashes ranging from 0-5 to 1-9 per cent. 

This day, (17th of March, 185S,) the sack of genuine best household flour, weighing 280 
lbs., delivered at the bakers' shop, costs 42s., and the number of sacks of flour converted 
weekly into bread by the London bakers is nearly 30,000, which gives about 12 sacks of 
flour per week as the average trade of each of them. The average capital of a baker doing 
that amount of business may be computed at £300, which, at 5 per cent., gives £15 interest ; 
his rent may be estimated at about £55, and the rates, taxes, gas, and other expenses at 
about £25, in all £95, or very nearly £1 16s. 6$d. per week, which sum, divided by 12, 
would give 3s. 0^d. per sack. 

In the ordinary plan of bread-making, /London bakers reckon that 1 sack of such a flour, 
weighing 280 lbs., will make 90 real 4-lb. loaves (not quartern) of pure, genuine bread, 
although a sack of such flour may yield him 94 or even 95 quartern (not 4-lb.) loaves.* 

From this account it may be easily imagined that if the baker could succeed in dispos- 
ing at once of all the loaves of his day's baking either by sale at his shop, or, still better, by 
delivery at his customers' residences, such a business would indeed be a profitable one, 
commercially speaking, for on that day he would sell from 28 to 34 lbs. of water at the 
price of bread, not to speak of the deficient weight ; but, on the one hand, so many people 
provokingly require to have their loaves weighed at the shop, and are so stingily particular 
about having their short weight made up ; and, on the other hand, the loaves, between the 
first, second, and third day, do so obstinately persist in letting their water evaporate, that 
the loss of weight thus sustained nearly balances the profit obtained upon the loaves sold on 
the first day at the shop, or to those customers who have their bread delivered at their 
own door, to those who the baker knows, from position or avocations, will never take the 
trouble to verify the weight of his loaves, and who, he says, are gentlefolks, and no mistake 
about it. 

As to those bakers who, by underbaking, or by the use of alum, or by the use of both 
alum and underbaking, manage to obtain 96, 98, 100, or a still larger number of loaves 
from inferior flour, or materials, their profit is so reduced by the much lower price at which 
they are compelled to sell their sophisticated bread, that their tamperings avail them but 
little ; their emphatically hard labor yields them but a mere pittance, except their business 
be so extensive that the small profits swell up into a large sum, in which case they only 
jeopardize their name as fair and honest tradesmen. 

Looking now at the improved ovens, of which we have been speaking merely in an 
economical point of view, and abstractedly from all other considerations, the profits realized 
by their use appears to be well worth the baker's attention. But as with the improved 
ovens the economy bears upon the wages and the fuel, the advantages are much less consider- 
able in a small concern than in a large one. Thus, the economy which, upon 12 sacks of 
flour per week, would scarcely exceed 20 shillings upon the whole, would, on the contrary, 
assume considerable proportions in establishments baking from 50 to 100 sacks per week. 
We give here the following comparative statements of converting flour into bread at the 
rate of 70 sacks per week, from documents which may be fully relied upon. 70 sacks of 
flour manufactured into genuine bread, in the ordinary way, would yield 6,300 real 4-lb. 
loaves, and the account would stand as follows, taking 90 loaves, weighing really 4 lbs., 
as the ultimate yield of 1 sack of good household flour, of the quality and price above 
alluded to : — 

By the Ordinary Process. 

6,300 loaves (4 lbs.) at Id. 

£ s. d, 
183 15 

* It is absolutely necessary thus to establish a distinction between four-pounds and quartern loaves, 
because the latter very seldom indeed have that weight, and this deficiency Is, in fact, one ui'uio proAls 
calculated upon; for, although the Act of Parliament (Will. IV. cap. xxxv'ii.) is very strict, and directs 
(sect, vii.) that bakers delivering bread by cart or carriage shall bo provided with scales, weights <&o., 
for weighing bread, this requisition is seldom, if ever, complied with. 

There are, of course, a few bakers whoso quartern loaves weigh exactly four pounds, but the immense 
majority are from four to six ounces short. 

Vol. III.— 13 

194 BEE AD. 


70 sacks of household flour at 37 s. 

Coals, gas, potatoes, yeast, salt, wages, and other baking ex- 
penses, at 5s. per sack ------- 

Kent, taxes, interest of capital, and general expenses - 

Net profit on 1 week's baking £12 5 

By Perkins's Process. 










— 171 























— 162 




6,300 loaves (4 lbs.) at Id. 


•70 sacks of flour at 37s. 

Yeast, potatoes, and salt, at Is. per sack - - - - 

Coals at Gd. per sack 

Wages of a man per week 

" 1 workman 

" 1 hand 

Wear and tear, and repairs 

Rent, interest on capital, (£1,500,) taxes, gas, waste, and general 
expenses, per week 

In Rolland's process the profits are very nearly the same as in that of Perkins', except 
the amount of fuel consumed is still more reduced, and does not amount, it is stated, to 
more than 44<i. per sack, which, for 70 sacks, is £1 6s. 3d., instead of £1 15s., or 9s. differ- 
ence between the two methods for baking that quantity of flour. 

The richness or nutritive powers of sound flour, and also of bread, are proportional to 
the quantity of gluten they contain. It is of great importance to determine this point, for 
both of these objects are of enormous value and consumption ; and it may be accomplished 
most easily and exactly, by digesting, in a water-bath, at the temperature of 167° F., 1,000 
grains of bread (or flour) with 1,000 grains of bruised barley malt, in 5,000 grains, or in a 
little more than half a pint, of water. When this mixture ceases to take a blue color from 
iodine, (that is, when all the starch is converted into a soluble dextrine,) the gluten left un- 
changed may be collected on a filter cloth, washed, dried at a heat of 212° F., and weighed. 
The color, texture, and taste of the gluten ought also to be examined, in forming a judg- 
ment of good flour or bread. - 

The question of the relative value of whit" and of brown bread, as nutritive agents, is 
one of very long standing, and the arguments on both sides may be thus resumed : — 

The advocates of brown bread hold — 

That the separation of the white from the brown parts of wheat grain, in making bread, 
is likely to be baneful to health ; 

That the general belief that bread made with the finest flour is the best, and that white- 
ness is a proof of its quality, is a popular error ; 

That whiteness may be, and generally is, communicated to bread by alum, to the injury 
of the consumer ; 

That the miller, in refining his flour, to please the public, removes some of the ingre- 
dients necessary to the composition and nourishment of the various organs of our bodies ; 
so that fine flour, instead of being better than the meal, is, on the contrary, less nourishing, 
and, to make the case worse, is also more difficult of digestion, not to speak of the enormous 
loss to the population of at least 25 per cent, of branny flour, containing from 60 to 70 per 
cent, of the most nutritious part of the flour, a loss which, for London only, is equal to at 
least 7,500 sacks of flour annually ; 

That the unwise preference given so universally to white bread, leads to the pernicious 
practice of mixing alum with the flour, and this again to all sorts of impositions and adul- 
terations ; for it enables the bakers who are so disposed, by adding alum, to make bread 
manufactured from the flour of inferior grain to look like the best and more costly, thus de- 
frauding the purchaser, and tampering with his health. 

On the other side, the partisans of white bread contend, of course, that all these asser- 
tions are without foundation, and their reasons were summed up as follows in the Bakers' 
Gazette, in 1849 :— 



*' The preference of the public for white bread is not likely to be an absurd prejudice, 
seein^ that it was not until after years of experience that it was adopted by them. 

" The adoption of white bread, in preference to any other sort, by the great body of the 
community, as a general article of food, is of itself a proof of its being the best and most 

" The finer and better the flour, the more bread can be made from it Fifty-six pounds 
of fine flour from good wheat will make seventy-two pounds of good, sound, well-baked 
bread, the bread having retained sixteen pounds of water. But bran, either fine or coarse, 
absorbs little or no water, and adds no more to the bread than its weight." 

And lastly, in confirmation of the opinion that white bread contains a greater quantity 
of nutriment than the same weight of brown bread, the writer of the article winds up the 
white bread defence with a portion of the Eeport of the Committee of the House of Com- 
mons, appointed in 1800, " to consider means for rendering more effectual the provisions 
of 13 Geo. III., intituled ' An Act for the better regulating the assize and making of 
Bread.' " 

In considering the propriety of recommending the adoption of further regulations and 
restrictions, they understood a prejudice existed in some parts of the country against any 
coarser sort of bread than that which is at present known by the name of " fine household 
bread," on the ground that the former was less wholesome and nutritious than the latter. 
The opinions of respectable physicians examined on this point are, — that the change of any 
sort of food which forms so great a part of the sustenance of man, might, for a time, affect 
some constitutions ; that as soon as persons were habituated to it, the standard wheaten 
bread, or even bread of a coarser sort, would be equally wholesome with the fine wheaten 
bread which is now generally used in the metropolis ; but that, in their opinion, the fine 
wheaten bread would go farther with persons who have no other food than the same quan- 
tity of bread of a coarser sort. 

^ It was suggested to them, that if only one sort of flour was permitted to be made, and a 
different mode of dressing it adopted, so as to leave it in the fine pollards, 52 lbs. of flour 
might be extracted from a bushel of wheat weighing 60 lbs., instead of 4*7 lbs., which would 
afford a wholesome and nutritious food, and add to the quantity 5 lbs. in every bushel, or 
somewhat more than : / 9 . On this they remarked that there would be no saving in adopting 
this proposition ; and they begged leave to observe, if the physicians are well founded in 
their opinions, that bread of coarser quality will not go equally far with fine wheaten bread, 
an increased consumption of wheaten bread would be the consequence of the measure. 

From the bakers' point of view, it is evident that all his sympathies must be in favor of 
the water-absorbing material, and therefore of the fine flour ; for each pound of water added 
and retained in the bread which he sells, represents this day so many twopences ; but the 
purchaser's interest lies in just the opposite direction. 

The question, however, is not, in the language of the Committee of the House of Com- 
mons of those days, or of the physicians whom they consulted, whether a given weight of 
wheaten bread will go farther than an equal weight of bread of a coarser sort ; nor whether 
a given weight of pure flour is more nutritious than an equal weight of the meal from the 
same wheat used in making -brown bread. The real question is, — Whether a given weight 
of wheat contains more nutriment than the flour obtained from that weight of wheat. 

The inquiry of the Committee of the House of Commons, and the defence of white bread 
versus brown bread, resting, as it does, in this respect, upon a false ground, is therefore 
perfectly valueless ; for whatever may have been the opinion of respectable physicians and 
of committees, either of those days or of the present times, one thing is certain — namely, 
that bran contains only 9 or 10 per cent, of woody fibre, that is, of matter devoid of nutri- 
tious property ; and that the remainder consists of a larger proportion of gluten and starch, 
fatty, and other highly nutritive constituents, with a few salts, and water, as proved by the 
following analysis by Millon : — 

Composition of Wheat Bran. 

Starch 52-0 

Gluten 14-9 

Sugar l-o 

Fatty matter • - - - - ... . 3-6 

Woody " 9-7 

Salts 5-0 

Water 13-8 

And it is equally certain that wheat itself — I mean the whole grain — does not contain 
more than 2 per cent, of unnutritious, or woody matter, the bran being itself richer, 
weight for weight, in gluten, than the fine flour ; the whole meal contains, accordingly, 
more gluten than the fine flour obtained therefrom. The relative proportions of gluten 



in the whole grain, in bran, and in flour of the same sample of wheat, were represented 
by the late Professor Johnston to be as follows : — 

Gluten of WJieat. 

Whole grain 12 per cent. 

Whole bran 14 to 18 " 

Fine flour - ' - 10 " 

Now, whereas a bushel of wheat weighing 60 lbs. produces, according to the mode of 
manufacturing flour for London, 47 lbs. — that is, 78 per .cent, of flour, the rest being bran 
and pollards-; if we deduct 2 per cent, of woody matter, and H per cent, for waste in 
grinding at the mill, the bushel of 60 lbs. of wheat would yield 58 lbs., or at least 96f per 
cent, of nutritious matter. 

It is, therefore, as clear as any thing can possibly be, that by using the whole meal in- 
stead of only the fine flour of that wheat, there will be a difference of about */ 8 in the pro- 
duct obtained from equal weights of wheat. 

In a communication made to the Royal Institute nearly four years ago, M. Mege Mouries 
announced that he had found under the envelope of the grain, in the internal part of the 
perisperm, a peculiar nitrogenous substance capable of acting as a ferment, and to which he 
gave the name of " cerealine." This substance, which is found wholly, or almost so, in the 
bran, but not in the best white flour, has the property of liquefying starch, very much in the 
same manner as diastase : and the decreased firmness of the crumb of brown bread is re- 
ferred by him to this action. The coloration of bread made from meal containing bran is 
not, according to M. Mege Mouries, due, as has hitherto been thought, to the presence of 
bran, but to the peculiar action of cerealin ; this new substance, like vegetable casein and 
gluten, being, by a slight modification, due perhaps to the contact of the air, transformed 
into a ferment, under the influence of which the gluten undergoes a great alteration, yield- 
ing, among other products, ammonia, a brown-colored matter analogous to ulmine, and A. 
nitrogenous product capable of transforming sugar into lactic acid. M. Mege Mouries having 
experimentally established, to the satisfaction of a committee consisting of MM. Chevreul, 
Dumas, Pelouze, and Peligot, that by paralyzing or destroying the action of cerealin, as 
described in the specification of his patent, bearing date the 14th of June, 1856, white 
bread, having all the characters of first quality bread, may be made, in the language of the 
said specification, " with using either all the white or raw elements that constitute either 
corn or rye, or with such substances as could produce, to this day, but brown bread." 

Cerealin, according to M. Mege Mouries, has two very distinct properties :— the first 
consists in converting the hydrated starch into glucose and dextrine ; the second, which is 
much more important in its results, transforms the glucose into lactic, acetic, butyric, and 
formic acid, which penetrate, swell up, and partly dissolve the gluten, rendering it pulpy 
and emulsive, like that of rye ; producing, in fact, a series of decompositions, yielding 
eventually a loaf having all the characteristics of bread made from inferior flour. 

In order to convert the whole of the farinaceous substance of wheat into white bread, it 
is therefore necessary to destroy the cerealin ; and the process, or series of processes, by 
which this is accomplished, is thus described by M. Mege Mouries in his specification : — 

" The following are the means I employ to obtain my new product : — 

" 1st. The application of vinous fermentation, produced by alcoholic ferment or yeast, 
to destroy the ferment that I call ' cerealine,' existing, together with the fragments of bran, 
in the raw flour, and which, in some measure, produces the acidity of brown bread directly, 
whilst it destroys indirectly most part of the gluten. 

" 2dly. The thorough purification of the said flour, either raw or mixed with bran, 
(after dilution and fermentation,) by the sifting and separating of the farinaceous liquid from 
the fragments of bran disseminated by the millstone into the inferior products of corn. 

" Sdly. The employing that part of corn producing brown bread in the rough state, as 
issuing from the mill after a first grinding, in order to facilitate its purification by fermen- 
tation and w r et sifting. 

" 4thly. The employing acidulated water (by, any acid or acid salt) in order to prevent 
the lactic fermentation, preserving the vinous fermentation, preventing the yellow color 
from turning into a brown color, (the ulmie acid,) and the good taste of corn from assuming 
that of brown bread. However, instead of acidulated water, pure water may be employed 
with an addition of yeast, as the acid only serves to facilitate the vinous fermentation. 

" 5thly. The grinding of the corn by means of millstones that crush it thoroughly, in- 
creasing thereby the quantity of foul parts, a method which will prove very bad with the 
usual process, and very advantageous with mine. 

" 6thly. The application of corn washed or stripped by any suitable means. 

" Vthly. The application of all these contrivances to wheat of every description, to rye, 
and other grain used in the manufacture of bread. 

" Sthlv. The same means applied to the manufacture of biscuits. 

" I will now describe the manner in which the said improvements are carried into effect. 

BREAD 197 

" First Instance. When flour of inferior quality is made use of. — This description of 
flour, well known in trade, is bolted or sifted at 73, 75, or 80 per cent., (a mark termed 
Scipion mark in the French War Department,) and yields bread of middle quality. By 
applying to this sort of flour a liquid yeast, rather different from that which is applied to 
white flour, in order to quicken the work and remove the sour taste of bread, a very nice 
quality will be obtained, which result was quite unknown to everybody to this day, and 
which none ever attempted to know, as none before me were aware of the true causes that 
produce brown bread, &e. 

" Now, to apply my process to the said flour, (of inferior mark or quality,) I take a part 
of the same — a fourth part, for instance — which I dilute with a suitable quantity of water, 
and add to the farinaceous liquid 1 portion of beer yeast for 200 portions of water, together 
with a small quantity of acid or acid salt, sufficient to impart to the said water the property 
of lightly staining or reddening the test-paper, known in France by the name of papier de 
tournesol. When the liquid is at full working, I mix the remaining portions of flour, which 
are kneaded, and then allowed to ferment in the usual way. The yeast applied, which is 
quite alcoholic, will yield perfectly white bread of a very nice taste ; and I declare that if 
similar yeast were ever commended before, it was certainly not for the purpose of prevent- 
ing the formation of brown bread, the character of which was believed to be inherent to the 
nature of the very flour, as the following result will sufficiently prove it, thus divesting such 
an application of its industrial appropriation. 

" Second Instance. When raw flour is made use of. — By raw flour, I mean the corn 
crushed only once, and from which 10 to 15 per cent, of rough bran have been separated. 
Such flour is still mixed with fragments of bran, and is employed in trade to the manufac- 
ture of" so-called white flour and bran after a second and third grinding or crushing. In- 
stead of that, I only separate, and without submitting it to a fresh crushing, the rough flour 
in two parts, about 70 parts of white flour and 15 to 18 of rough or coarse flour, of which 
latter the yeast is made ; this I dilute with a suitable quantity of water, sufficient to reduce 
the whole flour into a dough, say 50 per cent, of the whole weight of raw flour. To this 
mixture have been previously added the yeast and acid, (whenever acid is applied, which is 
not indispensable, as before stated,) and the whole is allowed to work for 6 hours at a tem- 
perature of 77° F., for 12 hours at 68°, and for 20 hours at 59°, thus proportionally to the 
temperature. While this working or fermentation is going on, the various elements (cerea- 
line, &c.) which, by their peculiar action, are productive of brown bread, have undergone 
a modification ; the rough parts are separated, the gluten stripped from its pellicles and dis- 
aggregated, and the same flour which, by the usual process, could have only produced deep 
brown bread, will actually yield first-rate bread, far superior to that sold by bakers, chiefly 
if the fragments of bran are separated by the following process, which consists in pouring 
on the sieve, described hereafter, the liquid containing the rough parts of flour thus disag- 
gregated and modified by a well-regulated fermentation. 

*' The sieve alluded to, which may be of any form, consists of several tissues of different 
tightness, the closest being ever arranged underneath or the most forward, when the sieve 
is of cylindrical or vertical form, is intended to keep back the fragments of bran, which 
would, by their interposition, impair the whiteness of bread, and, by their weight, diminish 
its nutritive power. The sifted liquid is white, and constitutes the yeast with which the 
white flour is mixed after being separated, so as to make a dough at either a first or several 
workings, according to the baker's practice. This dough works or ferments very quickly, 
and the bread resulting therefrom is unexceptionable. In case the whiteness or neatness 
of bread should be looked upon as a thing of little consequence, a broader sieve might be 
employed, or sieve used at all, and yet a very nice bread be obtained. 

" The saving secured by the application of my process is as follows : — By the common 
process, out of 100 parts of wheat, 70 or 75 parts of flour are extracted, which are fit to 
yield either white or middle bread ; whilst, by the improved process, out of 100 parts of 
wheat, 85 to 88 parts will be obtained, yielding bread of superior quality, of the best taste, 
neatness, and nutritious richness. 

" In ease new yeast cannot be easily provided, the same should be dried at a temper- 
ature of about 86° F., after being suitably separated by means of some inert dust, and pre- 
vious to being made use of, it should be dipped into 10 parts of water, lightly sweetened, 
for 8 to 10 hours, a fit time for the liquid being brought into a full fermentation, at which 
time the yeast has recovered its former power. The same process will hold good for manu- 
facturing rye bread, only 25 per cent., about, of course bran are to be extracted. For 
manufacturing biscuits, I use also the same process, only the dough is made very hard, and 
immediately taken into the oven, and the products thus obtained are far superior to the 
common biscuits, both for their good taste and preservation. Should, however, an old 
practice exelude all manner of fermentation, then I might dilute the rough parts of flour in 
either acidulated or non-acidulated water, there to be left to work for the same time as be- 
fore, then sift the water and decant it, after a proper settling of the farinaceous matters of ■ 
which the dough is to be made ; thus the action of the acid, decantation, and sifting, would 




effectively remove all causes of alteration, which generally impair the biscuits, made of in- 
ferior flour. 

" The apparatus required for this process is very plain, and consists of a kneading- 
trough, in which the foul parts are mixed mechanically, or by manual labor, with the liquid 
above mentioned. From this trough, and through an opening made therein, the liquid 
mixture drops into the fermenting tub, deeper than wide, which must be kept tightly closed 
during the fermenting work. At the lower part of this tub a cock is fitted, -which lets the 
liquid mixture down upon an inclined plane, on which the liquid spreads, so as to be equally 
distributed over the whole surface of the sieve. This sieve, of an oblong rectangular form, 
is laid just beneath, and its tissue ought to be so close as to prevent the least fragments of 
bran from passing through ; it is actuated by the hand, or rather by a crank. In all cases, 
that part of the sieve which is opposite to the cock must strike upon an unyielding body, 
for the purpose of shaking the pellicles remaining on the tissue, and driving them down 
towards an outlet on the lower part of the sieve, and thence into a trough purposely con- 
trived for receiving the waters issuing from the sieve, and discharging them into a tank. 

" The next operation consists in diluting those pellicles, or rougher parts, which could 
not pass through the sieve, sifting them again, and using the white water resulting there- 
from to dilute the foul parts intended for subsequent operations. The sieve or sieves may 
sometimes happen to be obstructed by some parts of gluten adhering thereto, which I wash 
off with acidulated water for silk tissues, and with an alkali for metallic ones. This washing 
method I deem very important, as its non-application may hinder a rather large operation, 
and therefore I wish to secure it. This apparatus may be liable to some variations, and ad- 
mit of several sieves superposed, and with different tissues, the broadest, however, to be 
placed uppermost. 

" Among the various descriptions and combinations of sieves that may be employed, the 
annexed figures show one that will give satisfactory results : 

" Fig. 87 is a longitudinal section, and J!g. 88 an end view, of the machine from which 
the bran is ejected. The apparatus rests upon a cast-iron framing, a, consisting of two 
cheeks, kept suitably apart by tie pieces, b ; a strong cross-bar on the upper part admits a 
wood cylinder c, circled round with iron, and provided with a wooden cock, d. The cylin- 
der, c, receives through its centre an arbor,/, provided with four arms, e, which arbor is sup- 
ported by two cross-bars, ij and h, secured by means of bolts to the uprights, i. Motion is 
imparted to the arbor, /, by a crank, _/, by pulleys driven by the endless straps, Jc, and by 
the toothed wheel, I, gearing into the wheel, m, which is keyed on the upper end of the ar- 
bor, /. Beneath the cylinder, c, two sieves, n and o, are bome into a frame, p, suspended 
on one end to two chains, g, and on the other resting on two guides or bearings, r, beneath 
which, and on the crank shaft, are cams, s, by which that end of the frame that carries the 
sieves is alternately raised and lowered. A strong spring, u, is set to a shaft borne by the 
framing, a, whilst a ratchet-wheel provided with a clink, allows the said spring, according 
to the requirements of the work, to give more or less impulse or shaking as the cams, *, are 
acting upon the frame-sieve carrying the sieve. Beneath the said frame a large hopper, t r 

BREAD. 199 

is disposed, to receive and lead into a tank the liquid passing through the sieves. The filter 
sieve is worked as follows : — After withdrawing, by means of bolting hutches, 70 per cent., 
about, of fine flour, I take out of the remaining 30 per cent, about 20 per cent, of groats, 
neglecting the remaining 10 per cent., from which, however, I could separate the little flour 
still adhering thereto, but I deem it more available to sell it off in this state. I submit the 
20 per cent, of groats to a suitable vinous fermentation, and have the whole taken into the 
cvlinder, c, there to be stirred by means of the arbor, /, and the arms, c ; after a suitable 
stirring, the cock, d, is opened, and the liquid is let out, spread on the uppermost sieve, n, 
which Tieeps back the coarsest bran. The liquid drops then into the second sieve or filter, 
o, by which the least fragments are retained ; the passage of the liquid through the filters 
is quickened by the quivering motion imparted by the cams, s, to the frame carrying the 

The advantages resulting from such a process are obvious : first, it would appear — and 
those experiments have been confirmed by the committee of the Acadejnie des Sciences, 
who had to report upon them — that no less than from 16 to 17 per cent, of white bread of 
superior quality can be obtained from wheat, which increase is not due to water, as in other 
methods, but is a true and real one, the Commissioners having ascertained that the bread 
thus manufactured did not contain more water than that made in the usual way, their com- 
parative examinations in this respect having given the. following results : — 

Loss by drying in Air. 



Old method 

37-8 - 

- 12-0 

New method 

---- 37-5 - 

- 14-0 

Difference - - - • - 00-3 2-0 

Another experiment by Peligot : — 

Loss by drying in Air at 248° F. 

Crumb and Crust. 

New method 34 - 9 per cent. 

Old method 34-1 

Difference. 00'8 

Since the enrolment of his Specification, however, M. Mege Mouries has made an im- 
provement, which simplifies considerably his original process, according to which the 
destruction of the cerealin, as we saw, was effected by ordinary yeast ; that is to say, by 
alcoholic fermentation. The last improvement consists in preventing cerealin from be- 
coming a lactic or glucosic ferment, by precipitating it with common salt, and not allow- 
ing it time to become a ferment. In effect, in order that cerealin may produce the 
objectionable effects alluded to, it must first pass into the state of ferment, and, as all 
nitrogenous substances require a certain time of incubation to become so,* if, on the one 
hand, cerealin be precipitated by means of common salt, the glucosic action is neutral- 
ized ; whilst, on the other hand, the levains being made with flour containing no cerealin 
— that is to say, with best white flour — if a short time before baking households or sec- 
onds are added thereto, it is clear that time will be wanting for it (the ferment) to become 
developed or organized, and that, under this treatment, the bread will remain white. 

The application of these scientific deductions will be better understood by the follow- 
ing description of the process : — 

100 parts of clean wheat are ground and divided as follows : — 

Best whites for leaven 40 - 

White groats, mixed with a few particles of bran - 38"0 

White groats, mixed with a larger quantity of bran - 8'0 

Bran (not used) 15-5 

Loss - - - - 0-5 


These figures vary, of course, according to the kind of wheat used, according to seasons, 
and according to the description of mill and the distance of the millstones used for grinding. 

" In order to convert these products into bread," says M. Mege Mouries, " a leaven is 
to be made by mixing the 40 parts of best flour above alluded to, with 20 parts of water, 
and proceeding with it according to the mode and custom adopted in each locality. This 
leaven, no matter how prepared, being ready, the 8 parts of groats mixed with the larger 
quantity of bran above alluded to, are diluted in 45 parts of water, in which 0-6 parts of 

* Communication of M. Mege Mouries to tbo Academio ties Sciences, January, 1S5S. 



common salt have been previously dissolved, and the whole is passed through a sieve, which 
allows the flour and water to pass through, but retains and separates the particles of bran. 
The watery liquid so obtained has a white color, is flocculent, and loaded with cerealin ; it 
no longer possesses the property of liquefying gelatinous starch, and weighs 38 parts, (the 
remainder of the water is retained in the bran, which has swelled up in consequence, and 
remains on the sieve.) The leaven is then diluted with that water, which is loaded with 
best flour, and is used for converting into dough the 38 parts of white groats above alluded 
to ; the dough is then divided into suitable portions, and, after allowing it to stand for one 
hour, it is finally put in the oven to be baked. As the operations just described take place 
at a temperature of 25° C, (= 77° F.,) the one hour during which the dough is left to itself, 
is not sufficient for the cerealin to pass into the state of ferment, and the consequence is the 
production of white bread. Should, however, the temperature be higher than that, or were 
the dough allowed to be kept for a longer time before baking, the bread produced, instead 
of being white, would be so much darker, as the contact would have lasted longer. By this 
process, 100 parts in weight of wheat yield 136 parts of dough, and finally, 115 parts in 
weight of bread," instead of 100, which the same quantity of wheat would have yielded in 
the usual way. This is supposing that the grinding of the wheat has been effected with 
close-set millstones ; if ground in the usual way, the average yield does not exceed 112 
parts in weight of bread. 

The substances which are now almost exclusively employed for adulterating bread, are 
water, alone or incorporated with rice, or water and alum : other substances, however, are 
or have been occasionally used for the same purpose ; they are, sulphate of copper, carbo- 
nate of magnesia, sulphate of zinc, carbonate of ammonia, carbonate and bicarbonate of pot- 
ash, carbonate and bicarbonate of K soda, chalk, plaster, lime, clay, starch, potatoes, and 
other fecula. 

This retention of water into bread is secured by underbaking, by the introduction of rice 
and feculas, and of alum. 

Underbaking is an operation which consists of keeping in the loaf the water which 
otherwise would escape while baking ; it is, therefore, a process for selling water at' the 
price of bread. It is done by introducing the dough into an oven unduly heated, whereby 
the gases contained in the dough at once expand, and swell it up to the ordinary dimen- 
sions, whilst a deep-burnt crust is immediately afterwards formed ; which, inasmuch as it is 
a bad conductor of heat, prevents the interior of the loaf from being thoroughly baked, and 
at the same time opposes the free exit of the water contained in the dough, and which the 
heat of the oven partly converts into steam ; while the crust becomes thicker and darker 
than it otherwise should be, a sensible loss of nutritive elements being sustained, at the 
same time, in the shape of pyrogenous products which are dissipated. 

The proportion of water retained in bread by underbaking is sometimes so large, that a 
baker may thus obtain as much as 106 loaves from a sack of flour. 

The addition of boiled rice to the dough is also pretty frequently used to increase the 
yield of loaves ; this substance, in fact, absorbs so much water, that as many as 116 quartern 
loaves have thus been obtained from one sack of flour. 

From a great number of experiments, made with a view to determine the normal quan- 
tity of water contained in the crumb of genuine bread, it is ascertained that it amounts, in 
new bread, from 38 at least to at most 47 per cent. 

The quantity of water contained in bread is easily determined by cutting a slice of it, 
weighing 500 grains, for example, placing it in a small oven heated by a gas-burner or a 
lamp to a temperature of about 220° F., until it no longer loses weight ; the difference 
between the first and last weighing (that is to say, the loss) indicating, of course, the amount 
of water. 

Alum, however, is the principal adulterating substance used by bakers, almost without 
exception, in this metropolis ; as was proved by Dr. Normanby, in his evidence before the 
Select Committee of the House of Commons, appointed in 1855, under the presidence of 
Mr. W. Scholefield, to inquire into the adulteration of food, drinks, and drugs, which as- 
sertion was corroborated and established beyond doubt by the other chemists who were 
examined also on the subject. 

The introduction of alum into bread not only enables the baker to give to bread made 
of flour of inferior quality the whiteness of the best bread, but to force and keep in it a 
larger quantity of water than could otherwise be done. We shall see presently that this 
fact has been denied, and on what grounds. 

The quantity of alum used varies exceedingly ; but no appreciable effect is produced 
when the proportion of alum introduced is less than 1 in 900 or 1,000, which is at the rate 
of 27 or 28 grains in a quartern loaf. The use of alum, however, has become so universal, 
and the Act of Parliament which regulates the matter has so long been considered as a dead 
letter from the trouble, and chance of pecuniary loss which it entails on the prosecutor 
should his accusation prove unsuccessful, that but few, and until quite lately none, of the 
public officers would undertake the discharge of a duty most disagreeable in itself, and at 
the same time full of risk. 

BREAD. 201 

vVlien alum is used in making bread, one of the two following things may happen : 
either the alum will be decomposed, as just said, in which case the alumina will, of neces- 
sity, be set free as soon as digestion will have decomposed the organic matter with which it 
was combined ; and thus it is presumable that either alum will be re-formed in the stomach, 
or that, according to Liebig, the phosphoric acid of the phosphates of the bread, uniting 
with the alumina of the alum, will form an insoluble phosphate of alumina, and the benefi- 
cial action of the phosphates will, consequently, be lost to the system ; and since phosphoric 
acid forms with alumina a compound hardly decomposable by alkalis or acids, this may, per- 
haps, explain the indigestibility of the London bakers' bread, which strikes all foreigners. — 
Letters on Chemistry. 

The last defence set up iu behalf of alumed bread to be noticed, is, that, with certain 
descriptions of flour, bread cannot be made without it ; that, by means of alum, a large 
quantity of flour is made available for human food, which, without it, must be withdrawn, 
and turned to some other less important uses, to the great detriment of the population, and 
particularly of the poor, who would be the first to suffer from the increase of the price of 
bread which such a withdrawal must fatally produce. 

The process usually adopted for the detection of alum, is that known as Kuhlman's pro- 
cess, which consists in incinerating about 3,000 grains of bread, porphyrizing the ashes so 
obtained, treating them by nitric acid, evaporating the mixture to dryness, and diluting the 
residue with about 300 grains of water, with the help of a gentle heat ; without filtering, a 
solution of caustic potash is then added, the whole is boiled a little, filtered, the filtrate is 
tested with a solution of sal ammoniac, and boiled for a few minutes. If a precipitate is 
formed, it is not alumina, as hitherto thought, and stated by Kuhlman and all other chem- 
ists, but phosphate of alumina, — a circumstance of great importance, not in testing for the 
presence of alumina, but for the determination of its amount, as will be shown further on, 
when entering into the details of the modifications which it is necessary to make to Kuhl- 
man's process. 

In a paper read in April, 1858, at the Society of Arts, Dr. Odling stated that out of 46 
examinations of ashes furnished him by Dr. Gilbert, and treating them by the above process, 
he (Dr. Odling) obtained, to use his own words, " in 21 instances, the celebrated white pre- 
cipitate said to be indicative of alumina and alum, so that, had these samples been in the 
manufactured instead of the natural state — had the wheat, for example, been made into 
flour — I should have been justified, according to the authority quoted, in pronouncing it to 
be adulterated with alum. But a subsequent examination of the precipitates I obtained, 
showed that in reality they were not due to alumina at all. Mr. Kuhlman's process, as 
above described, is possessed of rare merits : it will never fail in detecting alumina when 
present, and will often succeed in detecting it when absent also. The idea of weighing this 
olla podrida of a precipitate, and from its weight calculating the amount of alum present, 
as is gravely recommended by great anti-adulteration adepts, is too preposterous to require 
a moment's refutation." 

Having stated the question in dispute as it at present stands, we must leave it to be dis- 
cussed in another place. 

In order, however, to render the process for the detection of alum in bread free from 
objections, the following method is recommended. It requires only ordinary care, and it is 
perfectly accurate : — 

Cut the loaf in half; take a thick slice of crumb from the middle, carefully trimming 
the edges so as to remove the crust, or hardened outside, and weigh off 1,500 or 3,000 
grains of it ; crumble it to powder, or cut it into slices, and expose them, on a sheet of 
platinum tray turned up at the edges, to a low red heat, until fumes are no longer evolved, 
and the whole is reduced to charcoal, which will require from twenty to forty minutes, ac- 
cording to the quantity ; transfer the charcoal to a mortar, and reduce it to fine powder ; 
put now this finely-pulverized charcoal back again on the platinum foil tray, and leave it ex- 
posed thereon to a dark cherry-red heat until reduced to gray ashes, for which purpose gas- 
furnace lamps will be found very convenient. Only a cherry-red heat should be applied, 
because at a higher temperature the ashes might fuse, and the incineration be thus retarded. 
Remove the source of heat, drench the gray ashes with a concentrated solution of nitrate of 
ammonia, and carefully reapply the heat ; the last portions of charcoal will thereby be 
burnt, and the ashes will then have a white or drab color. Drench them on the tray with 
moderately strong and pure hydrochloric acid, and after one or wo minutes' standing, wash 
the contents of the platinum foil tray with distilled water, into a porcelain dish ; evaporate 
to perfect dryness, in order to render the silica insoluble ; drench the perfectly dry residue 
with strong and pure muriatic acid, and, after standing for five or six minutes, dilute the 
whole with water, and boil ; while boiling, add carefully as much carbonate of soda as is 
necessary nearly, but not quite, to saturate the acid, so that the liquor may still be acid ; 
add 'as much pure alcohol-potash as is necessary to render it strongly alkaline ; boil the 
whole for about three or four minutes, and filter. If now, after slightly supersaturating the 
strongly alkaline filtrate with pure muriatic acid, the further addition of a solution of car- 

202 BEEAD. 

bcmate of ammonia produces, either at once or after heating it for a few minutes, a light, 
white flocculent precipitate, it is a sign of the presence of alumina, the identity of which is 
confirmed by collecting it on a filter, putting a small portion of it on a platinum hook or 
on charcoal, heating it thereon, moistening the little mass with nitrate of cobalt, and again 
strongly heating it before the blowpipe ; when if, without fusing, it assumes a beautiful blue 
color, the presence of alumina is corroborated. If the operator possesses a silver capsule 
he will do well to use it instead of a porcelain one for boiling the mass with pure caustic 
alcohol-potash, in order to avoid all chance of any silica (from the glaze) becoming dissolved 
by the potash, and afterwards simulating the presence of alumina, though, if the boiling be 
not protracted, a porcelain capsule is quite available. It is, however, absolutely necessary 
that he should use potasse a I 'alcohol, for ordinary caustic potash always contains some, and 
occasionally considerable, quantities of alumina, and is totally unsuited for such an investi- 
gation. Even potasse a Palcohol retains traces of silica, either alone, or combined with 
alumina ; so that for this, and other reasons which will be explained presently, an extrava- 
gant quantity of it should not be used. 

Lastly, carbonate of ammonia is preferable to caustic ammonia for precipitating the 
alumina, since that earth is far from being insoluble in caustic ammonia. 

The liquor from which the alumina has been separated should now be acidified with hy- 
drochloric acid, and tested with chloride of barium, which should then yield a copious pre- 
cipitate of sulphate of barytes. 

The only precipitate which can, under the circumstances of the experiment, simulate 
alumina, is the phosphate of that earth, which behaves with all reagents as pure alumina. 
Such a precipitate, therefore, if taken account of as pure alumina, would altogether vitiate a 
quantitative analysis if the amount of alum were calculated from it ; but the proof that a 
certain quantity of alum had been used in the bread from which it had been obtained would 
remain unshaken ; since alumina, whether in that state or in that of its phosphate, could 
not have been found except a salt of alumina — to wit, alum — had been used by the baker. 
"When, therefore, the exact amount of alumina has to be determined, the precipitate in 
question should be submitted to further treatment in order to separate the alumina ; and 
this can be done easily and rapidly by dissolving the precipitate in nitric acid, adding a little 
metallic tin to the liquor, and boiling. The tin becomes rapidly oxidized, and remains in 
the state of an insoluble white powder, which is a mixture of peroxide of tin and of phos- 
phate of tin, at the expense of all the phosphoric acid of any earthy phosphate which may 
have been present. The whole mass is evaporated to dryness, and the dry residue is then 
treated by water and filtered, in order to separate the insoluble white powder, and the fil- 
trate which contains the alumina should now be supersaturated with carbonate of ammonia. 
If a precipitate is formed, it is pure alumina. The white insoluble powder, after wash- 
ing, may be dissolved in hydrochloric acid, and after diluting the solution with water, the 
tin may be precipitated therefrom by passing through it a stream of sulphuretted hydrogen 
to supersaturation, leaving at rest for ten or twelve hours, filtering, boiling the filtrate until 
all odor of sulphuretted hydrogen has disappeared ; an excess of nitrate of silver is then 
added, and the liquor filtered, to separate the chloride of silver produced, and exactly neu- 
tralizing the filtrate with ammonia ; and if a lemon-yellow precipitate is produced, immedi- 
ately soluble in the slightest excess of either ammonia or nitric acid, it is basic phosphate 
of silver, (3AgO,) PhO 5 , the precipitate obtained in the first instance being thus proved to 
be phosphate of alumina. The pure alumina obtained may now be collected on a filter, 
washed with boiling water, thoroughly dried, and then ignited and weighed. One grain of 
alumina represents 9'02'7 grains of crystallized alum. 

In testing bread for alum, it should be borne in mind, however, that the water used for 
making the dough generally contains a certain quantity of sulphates, and that a precipitate 
of sulphate of barytes will therefore be very frequently obtained, though much less consid- 
erable than when alum has been used. Some waters called " selenitous " contain so much 
sulphate of lime in solution, that if they were used in making the dough, chloride of barium 
would afford, of course, a considerable precipitate. For these reasons, therefore, the sepa- 
ration and identification of alumina are the only reliable proofs ; because, as that earth does 
not exist normally in any shape in wheat or common salt otherwise than in traces, the proof 
that alum has been used becomes irresistible when we find, on the one hand, alumina, and, 
on the other, a more considerable amount of sulphate of barytes than, except under the 
most extraordinary circumstances, genuine bread would yield. 

Sulphate of copper, like alum, possesses the property of hardening gluten, and thus, 
with a flour of inferior quality, bread can be made of good appearance, as if a superior flour 
had been used. 

Lime water has been recommended by Liebig as a means of improving the bread made 
from inferior flour, or of flour slightly damaged, by keeping, by warehousing, or during 
transport in ships ; and this method, at the meeting of the British Association at Glasgow, 
in 1855, was reported as having been tried to a somewhat considerable extent by the bakers 
of that town, and with success, the bread kneaded with lime water, instead of pure water, 


beinc of good appearance, good taste, good texture, and free from the sour taste which in- 
variably belongs to alumed or even to genuine bread ; — admitting all this to be true, still 
we should deprecate the use of lime water in bread, because it cannot be done with impu- 
nity ; however small the dose of additional matter may be considered when taken separately, 
it is always large when considered as portion of an article of food like bread, consumed day 
after day, and at each meal, without interruption. To allow articles of food to be tampered 
with, under any circumstances, is a dangerous practice, even if it were proved that it can be 
done without risk, which, however, is not the case ; and Liebig himself has said that chem- 
ists should never propose-the use of chemical products for culinary preparations. 

The quantity of ashes left after the incineration of genuine bread, varies from 1 -5 at 
least to at most 3 per cent. ; and if the latter quantity of ashes be exceeded, the excess may 
safely be pronounced to be due to an artificial introduction of some saline or earthy matter. 

As to the addition to bread of potatoes, beans, rice, turnips, maize, or Indian corn, 
which has occasionally been practised to a considerable extent, especially in years of scarcity, 
it is evident that they may be, and are actually permitted under the Act of Parliament, 
Will. IV., cap. 27, sect. 11. As may be seen below, bread in which these ingredients 
replace a certain quantity of flour, is, of course, perfectly wholesome ; but as a given weight 
of it contains less nourishment than pure wheat bread, it is clear that if the mixed bread 
were sold under the name, or at the price, of wheat bread, it would be a fraud on the pub- 
lic, and more especially upon the poor ; but the admixture is not otherwise objectionable. 

In his " New Letters on Chemistry," Liebig makes the following remarks on the sub- 
ject :— 

" The proposals which have hitherto been made to use substitutes for flour, and thus 
diminish the price of bread in times of scarcity, prove how much the rational principles of 
hygiene are disregarded, and how unknown the laws of nutrition are still. 

" It is with food as with fuel. If we compare the price of the various kinds of coals, of 
wood, of turf, we shall find that the number of pence paid for a certain volume or weight of 
these materials is about proportionate to the number of degrees of heat which they evolve 
in burning. . . . The mean price of food in a large country is ordinarily the criterion 
of its nutritive value. . . . Considered as a nutritive agent, rye is quite as dear as 
wheat ; such is the case, also, with rice and potatoes ; in fact, no other flour can replace 
wheat in this respect. In times of scarcity, however, these ratios undergo modification, and 
potatoes and rice acquire then a higher value, because, in addition to their natural value as 
respiratory food, another value is superadded, which, in times of abundance, is not taken 
into account. 

" The addition to wheat flour of potato starch, of dextrine, of the pulp of turnips, gives 
a mixture, the nutritive value of which is equal to that of potatoes, or perhaps less ; and it 
is evident that one cannot consider as an improvement this transformation of wheat flour 
into a food having only the same value as rice or potatoes. The true problem consists in 
communicating to rice and to potatoes a power equal to that of wheat flour, and not in ' 
doing the reverse. At all events it is always better to cook potatoes by themselves, and 
eat them, than with bread ; the Legislature should even prohibit their addition to bread, on 
account of the fraud which the permission must inevitably lead to." 

The detection of potato starch, of beans, peas, Indian corn, rice, and other feculas, 
which is so easily effected by means of the microscope in flour, is exceedingly difficult, if 
not impossible, in bread. Bread which has been made of flour mixed with Indian com is 
harsher to the touch, and has frequently a slight yellowish color, and, when moistened with 
solution of potash of ordinary strength, a yellow or greenish-yellow tinge is developed. — A. N. 

BREWING. (Brasser, Fr. ; Brauen, Germ.) The art of making beer, or an alcoholic 
liquor, from a fermented infusion of some saccharine and amylaceous substance with water. 
For a description and analysis of which, and of the substances usually employed in its fer- 
mentation, see the article Beer. 

The processes of brewing may be classed under three heads : — the mashing, the boiling, 
and the fermentation. 

For the principles which should guide the brewer in the conduct of these operations, we 
refer to the article Beer, where it will be seen that the ultimate success of the entire series 
depends greatly on the regulation of the temperature, the duration, and the proper manage- 
ment of the initial process of mashing. 

With regard to temperature, the brewer must not only regulate the heat of the water 
for the first mash by the color, age, and quality of the malt, whether pale, amber, or brown, 
but he should also mark the temperature of the atmosphere as influencing that of the malt, 
and the absorption of the heat by the utensils employed ; remarking that well-mellowed and 
brown malt will bear a higher mashing heat than pale or newly dried, and that the best 
results are produced when the mash can be maintained at an equable temperature, from 
160° to 165°. 

The duration of the mash must also have reference to the required quality of the beer, 
whether intended for keeping some time in store, or for present use, as influencing the 




relative proportions of dextrine and sugar. The following table, by Levesque, will exem- 
plify the foregoing remarks. 

The first column gives the temperature of the air at the time of mashing. 

The second column shows the heat of the water, the quantity used, and the resulting 
heat of the mass — noting, that if the water has been let into the mash-tun, at the boiling 
point, and allowed to cool down, or the vessel has been thoroughly warmed before the com- 
mencement of the process, the heat may be taken several degrees lower. 

The third column shows the time for the standing of the mash ; but this will be modi- 
fied, as before stated, by the quality of the extract required. 

The bulk of the materials used must also enter into the consideration of the temperature, 
as a large body of malt will attain the required temperature with a mashing heat lower than 
a small quantity ; the powers of chemical action and condensation of heat being increased 
with increase of volume. 

Donovan, speaking of the temperature to be employed in mashing, lays down the fol- 
lowing as a general rule : — For well-dried pale malt, the heat of the first mashing liquor 
may be, but should never exceed, 170° ; the heat of the second may be 180° ; and, for a' 
third, the heat may be, but need never exceed, 185°. 

The quantity of water, termed liquor, to be employed for mashing, depends upon the 
greater or less strength to be given to the beer, but, in all cases, from one barrel and a halt 
to one barrel and three firkins is sufficient for the first stiff mashing, but more liquor may 
be added after the malt is thoroughly wetted. 

The grains of the crushed malt, after the wort is drawn off, retain from 32 to 40 gallons 
of water for every quarter of malt. A further amount must be allowed for the loss by 
evaporation in the boiling and cooling, and the waste in fermentation, so that the amount 
of liquor required for the mashing will, in some instances, be double that of the finished 
beer, but in general the total amount will be reduced about one-third during the various 

Table of Hashing Temperatures. 


.- High-dried. 






"" ! 



Heut of 











Heat of Mash, 


Heat of Mash, 



Heat oi 




146° to 



145° to 147°. 



144° to 146°. 



143° to 145°. 












6 Firkins 



1 Firkins 8 Firkins 



9 Firkins 

10 Firkins 



11 FirkinB 

12 Firkins 



per Qr. 



per Qr.. 

per Qr. 



per Qr. 

per Qr 


per Qr. 

per Qr. 





H. M, 


H. M 


H. M. 



















! 15 










169-19 jl-00 




1 20 







■j -in i 















■j no 



107 37 








3 -00 











4 00 


ISO -10 


3 00 






167 00 















166 00 





4 00 

45 177-94 


3 00 




2 00 








1 50 






166 36 




162-82 1100 







3 00 







10191 |l-00 



3 40 

1 60 









162 00 

161-00 10-55 




1 65 










160-19 0-50 






167 07 








159-28 045 

Heat of the Tap, 

Heat of the Tap, 

Heat of the Tap, 

Heat of 

the Tap, 

144° to 146°. 

143° to 145\ 

142° to 144° 

141° t< 


The following example will give an idea of the proportions for an ordinary quality of 
beer : — 

Suppose 13 imperial quarters of the best pale malt be taken to make 1,500 gallons of 
beer, the waste may be calculated at near 900 gallons, or 2,400 gallons of water will be re- 
quired in mashing. ■ 

As soon as the water in the copper has attained the heat of 145° in summer, or 167° in 
winter, 600 gallons of it are to be run off into the mash-tub, (which has previously been well 
cleansed or scalded out with boiling water,) and the malt gradually but rapidly thrown in 
and well intermixed, so that it may be uniformly moistened, and that no lumps remain. 
After continuing the agitation for about half an hour, more liquor, to the amount of 450 
gallons, at a! temperature of 190°, may be carefully and gradually introduced, (it is an ad- 
vantage if this can be done by a pipe inserted under the false bottom of the mash-tub,) the 
agitation being continued till the whole assumes an equally fluid state, taking care also to 
" allow as small a loss of temperature as possible during the operation, the resulting temper- 
ature of the mass being not less than 143°, or more than 14S°. 



The mash is then covered close, and allowed to remain at rest for an hour, or an hour 
and a half, after which the tap of the mash-tub is gradually opened, and if the wort that 
first flows is turbid, it should be carefully returned into the tun until it runs perfectly limpid 
and clear. The amount of this first wort will be about 675 gallons. 

Seven hundred and fifty gallons of water, at a temperature from ISO to 185°, may now 
be introduced, and the mashing operation repeated and continued until the mass becomes 
.uniformly fluid as before, the temperature being from 160° to 170°. It is then again 
covered and allowed to rest for an hour, and the wort of the first mash having been quickly 
transferred from the underbade to the copper, and brought to a state of ebullition, the wort 
of the second mash is drawn off with similar precaution, and added to it. A third quantity 
of water, about 600 gallons, at a temperature of 185° or 190°, should now be run through 
the goods in the mash-tun by the sparging process, or any means that will allow the hot 
liquor to percolate through the grains, displacing and carrying down the heavier and more 
valuable products of the first two mashings. The wort is now boiled with the hops from 
one to two hours. 

The object of boiling the wort is not merely evaporation and concentration, but extrac- 
tion, coagulation, and, finally, combination with the hops ; purposes which are better accom- 
plished in a deep confined copper, by a moderate heat, than in an open, shallow pan, with a 
quick fire. The copper, being encased above in brickwork, retains its digesting tempera- 
ture much longer than the pan could do. The waste steam of the close kettle, moreover, 
can be economically employed in communicating heat to water or weak worts ; whereas the 
exhalations from an open pan would prove a nuisance, and would need to be carried off by 
a hood. The boiling has a four-fold effect : 1, it concentrates the wort ; 2, during the 
earlier stages of heating, it converts the starch into sugar, dextrine, and gum, by means of 
the diastase ; 3, it extracts the substance of the hops diffused through the wort ; 4, it co- 
agulates the albuminous matter present in the grain, or precipitates it by means of the tannin 
of the hops. 

The degree of evaporation is regulated by the nature of the wort and the quality of the 
beer. Strong ale and stout, for keeping, require more boiling than ordinary porter or 
table-beer, brewed for immediate use. The proportion of the water carried off by evapora- 
tion is usually from a seventh to a sixth of the volume. The hops are introduced at the 
commencement of the process. They serve to give the beer not only a bitter aromatic 
taste, but also a keeping quality, or they counteract its natural tendency to become sour — 
an effect partly due to the precipitation of the albumen and starch, by their resinous and 
tanning constituents, and partly to the antifermentable properties of their lupuline, bitter 
principle, ethereous oil, and resin. In these respects, there is none of the bitter plants which 
can be substituted for hops with advantage. For strong beer, -powerful fresh hops should 
be selected ; for weaker beer, an older and weaker article will suffice. 

The stronger the hops are, the longer time they require for extraction of their virtues ; 
for strong hops, an hour and a half or two hours' boiling may be proper ; for a weaker sort, 
half an hour or an hour may be sufficient ; but it. is never advisable to push this process too 
far, lest a disagreeable bitterness, without aroma, be imparted to the beer. In some brew- 
eries, it is the practice to boil the hops with a part of the wort, and to filter the decoction 
through a drainer, called the jack hop-back. The proportion of hops to malt is very 
various ; but, in general, from 1J lbs. to li lbs. of the former are taken for 100 lbs. of the 
latter in making good table beer. For porter and strong ale, 2 lbs. of hops are used, or 
even more ; for instance, from 2 lbs. to 2+ lbs. of hops to a bushel of malt, if the beer be 
destined for the consumption of India. 

During the boiling of the two ingredients, much coagulated albuminous matter in various 
states of combination, makes its appearance in the liquid, constituting what is called the 
breaking or curdling of the wort, when numerous minute flocks are seen floating in it. 
The resinous, bitter, and oily-ethereous principles of the hops combine with the sugar and 
gum, or dextrine of the wort ; but for this effect they require time and heat ; showing that 
the boil is not a process of mere evaporation, but one of chemical reaction. A yellowish- 
green pellicle of hop-oil and resin appears upon the surface of the boiling wort, in a some- 
what frothy form : when this disappears, the boiling is presumed to be completed, and the 
beer is strained off into the cooler. The residuary hops may be pressed and used for an in- 
ferior quality of beer ; or they may be boiled with fresh wort, and be added to the next 
brewing charge. 

After being strained from the hops, by passing through the false bottom of the hop- 
jack, and allowed to rest on the coolers a sufficient time to deposit the greatest portion of 
the flocks separated in the boiling, the cooling process is rapidly completed by the action 
of the Befrificrator. See Refrigeration of Worts, vol. ii. 

The wort is then ready for the inoculation of the yeast and the commencement of the 
fermentative process, which completes the finished beer. See the articles Beer and Fer- 
mentation. — R. W. H. 

BREZILIN and BREZILEIN. According to M. Preisscr, the coloring matter of Brazil 
wood (Brczilin) is an oxide of a base Brezilein, which lias no color. 




BRICK. (Brique, Fr. ; Backsteinc, Ziegelsteine, Germ.) A solid rectangular mass of 
baked clay, employed for building purposes. 

The natural mixture of clay and sand, called loam, as well as marl, which consists of 
lime and clay with little or no sand, are the materials usually employed in the manufacture 
of bricks. 

There are few places in this country which do not possess alumina in combination with 
silica and other earthy matters, forming a clay from which bricks can be manufactured. 
That most generally worked is found on or near the surface in a plastic state. Others are 
bard marls on the coal measure, new red sandstone, and blue lias formations. It is from 
these marls that the blue bricks of Staffordshire and the fire-bricks of Stourbridge are made. 
Marl has a greater resemblance to stone and rock, and varies much in color ; blue, red, 
yellow, &c. From the greatly different and varying character of the- raw material, there is 
an equal difference in the principle of preparation for making it into brick ; while one 
merely requires to be turned over by hand, and to have sufficient water worked in to make 
it subservient to manual labor, the fire-clays and marls must be ground down to dust, and 
worked by powerful machinery, before they can be brought into even a plastic state. Now 
these various clays also shrink in drying and burning from 1 to 15 per cent., or more. This 
contraction varies in proportion to the excess of alumina over silica, but by adding sand, 
loam, or chalk, or (as is done by the London brick-makers) by using ashes or breeze — as it 
is technically called — this can be corrected. All clays burning red contain oxides of iron, 
and those having from 8 to 10 per cent., burn of a blue, or almost a black color. The 
bricks are exposed in the kilns to great heat, and when the body is a fire-clay, the iron, 
melting at a lower temperature than is sufficient to destroy the bricks, gives the outer sur- 
face of them a complete metallic coating. Bricks of this description are common in Staf- 
fordshire, and when made with good machinery, (that is, the clay being very finely ground,) 
are superior to any in the kingdom, particularly for docks, canal or river locks, railway- 
bridges, and viaducts. In Wolverhampton, Dudley, and many other towns, these blue 
bricks are commonly employed for paving purposes. Other clays contain lime, and no iron ; 
these burn white, and take less heat than any other to burn hard enough for the use of the 
builder, the lime acting as a flux on the silica. Many clays contain iron and lime, with the 
lime in excess, when the bricks are of a light dun color, or white, in proportion to the 
quantity of that earth present ; if magnesia, they have a brown color. If iron is in excess, 
they burn from a pale red to the color of cast-iron, in proportion to the quantity of metal. 

There are three classes of brick earths : — 

1st. Plastic clay, composed of alumina and silica, in different proportions, and contain- 
ing a small percentage of other salts, as of iron, lime, soda, and magnesia. 

2d. Loams, or sandy clays. 

3d. Marls; of which there are also three kinds ; clayey, sandy, and calcareous, according 
to the proportions of the earth of which they are composed, viz., alumina, silica, and lime. 

Alumina is the oxide of the metal aluminium, and it is this substance which gives tenac- 
ity or plasticity to the clay-earth, having a strong affinity for water. It is owing to excess 
of alumina that many clays contract too much in drying, and often crack on exposure 
to wind or sun. By the addition of sand, this clay would make a better article than we 
often see produced from it. Clays contain magnesia and other earthy matters, but these 
vary with the stratum or rock from which they are composed. It would be impossible to 
give the composition of these earths correctly, for none are exactly similar ; but the follow- 
ing will give an idea of the proportions of the ingredients of a good brick earth : silica, 
three-fifths ; alumina, one-fifth ; iron, lime, magnesia, manganese, soda, and potash forming 
the other one-fifth. 

The clay, when first raised from the mine or bed, is, in very rare instances, in a state to 
allow of its being at once tempered and moulded. The material from which fire-bricks are 
manufactured has the appearance of ironstone and blue lias limestone, and some of it is re- 
markably hard, so that in this and many other instances, in order to manufacture a good 
article, it is necessary to grind this material down into particles as fine as possible. 

Large quantities of bricks are made from the surface marls of the new red sandstone and 
blue lias formations. These also require thorough grinding, but from their softer nature it 
can be effected by less powerful machinery. — Chamberlain. 

Recently, some very valuable fire-bricks have been made from the refuse of the China 
Clay Works, of Devonshire. The quartz and mica left after the Kaolin has been washed 
out, are united with a small portion of inferior clay, and made into bricks. These are found 
to resist heat well, and are largely employed in the construction of metallurgical works. 
See Clay. 

The principal machines which- have been worked in brick-making are three — 1st, the 
pug-mill ; 2d, the wash-mill ; 3d, the rolling-mill. 

The pug-mill is a cylinder, sometimes conical, generally worked in a vertical position, 
with the large end up. Down the centre of this is a strong revolving vertical shaft, on 
which are hung horizontal knives, inclined at such an angle as to form portions of a screw, 

BRICK. 207 

that is, the knives follow each other at an angle forming a series of coils round this shaft. 
The bottom knives are larger, and vary in form, to throw oft* the clay, in some mills verti- 
cally, in others horizontally. Some have on the bottom of the shaft one coil of a screw, 
which throws the clay off more powerfully where it is wished to give pressure. 

The action of this mill is to cut the clay with the knives during their revolution, and so 
work and mis it, that on its escape it may be one homogeneous mass, without any lumps 
of hard untempered clay ; the clay being thoroughly amalgamated, and in the toughest state 
in which it can be got by tempering. This mill is an excellent contrivance for the purpose 
of working the clay, in combination with rollers ; but if only one mill is worked, it is not 
generally adopted, for, although it tempers, mixes, and toughens, it does not extract stones, 
crush up hard substances, or free the clay from all matters injurious to the quality of the 
ware when ready for market. This mill can be worked by either steam, water, or horse 
power ; but it takes much power in proportion to the quantity of work which it performs. 
If a brick is made with clay that has passed- the pug-mill, and contains stones, or marl not 
acted on by weather, or lime-shells, (a material very common in clays,) or any other extra- 
neous matter injurious to the brick, it is apparent from the action of this mill that it is not 
removed or reduced. The result is this : the bricks being, when moulded, in a very soft 
state of tempered material, or mud, considerably contract in drying, but the stones or hard 
substances not contracting, cause the clay to crack ; and even if they should not be suffi- 
ciently large to do this in drying, during the firing of the bricks there is a still further con- 
traction of the clay, and an expansion of the stone, from the heat to which it is subjected, 
and the result is generally a faulty or broken brick, and, on being drawn from the kilns, the 
bricks are found to be imperfect. 

The earth, being sufficiently kneaded, is brought to the bench of the moulder, who 
works the clay into a mould made of wood or iron, and strikes off the superfluous matter. 
The bricks are next delivered from the mould, and ranged on the ground ; and when they 
have acquired sufficient firmness to bear handling, they are dressed with a knife, and staked 
or built up in long dwarf walls, thatched over, and left to dry. An able workman will 
make, by hand, 5,000 bricks in a day. 

The different kinds of bricks made in England are principally place bricks, gray and red 
stocks, marl facing bricks, and cutting bricks. The place bricks and stocks are used in 
common walling. The marls are made in the neighborhood of London, and used in the 
outside of buildings ; they are very beautiful bricks, of a fine yellow color, hard, and well 
burnt, and, in every respect, superior to the stocks. The finest kind of marl and red bricks, 
called cutting bricks, are used in the arches over windows and doors, being rubbed to a 
centre, and gauged to a height. 

Bricks, in this country, are generally baked either in a clamp or in a kiln. The latter 
is the preferable method, as less waste arises, less fuel is consumed, and the bricks are sooner 
burnt. The kiln is usually 13 feet long, by lOJ- feet wide, and about 12 feet in height. 
The walls are one foot two inches thick, carried up a little out of the perpendicular, inclined 
towards each other at the top. The bricks are placed on flat arches, having holes left in 
them resembling lattice-work ; the kiln is then covered with pieces of tiles and bricks, and 
some wood put in, to dry them with a gentle fire. 

This continues two or three days before they are ready for burning, which is known by 
the smoke turning from a darkish color to semi-transparency. The mouth or mouths of the 
kiln are now dammed up with a shinlog, which consists of pieces of bricks piled one upon 
another, and closed with wet brick earth, leaving above it just room sufficient to receive a 
fagot. The fagots are made of furze, heath, brake, fern, &c, and the kiln is supplied with 
these until its arches look white, and the fire appears at the top, upon which the fire is 
slackened for an hour, and the kiln allowed gradually to cool. This heating and cooling is 
repeated until the bricks are thoroughly burned, which is generally done in 48 hours. 
One of these kilns will hold about 20,000 bricks. 

Clamps are also in common use. They are made of the bricks themselves, and generally 
of an oblong form. The foundation is laid with place brick, or the driest of those just 
made, and then the bricks to be burnt are built up, tier upon tier, as high as the clamp is 
meant to be, with two or three inches of broeze or cinders strewed between each layer of 
bricks, and the whole covered with a thick stratum of breeze. The fire place is perpen- 
dicular, about three feet high, and generally placed at the vest end ; and the flues are 
formed by gathering or arching the bricks over, so as to leave a space between each of nearly 
a brick wide. The flues run straight through the clamp, and are filled with wood, coals, 
and breeze, pressed closely together. If the bricks are to be burnt off quickly, which may 
be done in 20 or 30 days, according as the weather may suit, the flues should be only at 
about six feet distance ; but if there be no immediate hurry, they may be placed nine feet 
asunder, and the clamp left to burn off slowly. 

The following remarks by Mr. H. Chamberlain, on the drying of bricks, have an especial 
value from the great experience of that gentleman, and his careful observation of all the 
conditions upon which the preparation of a good brick depends : — 



" The drying of bricks ready for burning is a matter of great importance, and requires 
more attention than it generally receives. From hand-made bricks we have to evaporate 
some 25 per cent, of water before it is safe to burn them. In a work requiring the make 
of 20,000 bricks per day, we have to evaporate more than 20 tons of water every 24 hours. 
Hand-made bricks lose, in drying, about one-fourth of their weight, and in drying and 
burning about one-third. The average of machine bricks — those made of the stiff plastic ' 
clay — do not lose more than half the above amount from evaporation, and are, therefore, of 
much greater specific gravity than hand-made ones. 

" The artificial drying of bricks is carried on throughout the year uninterruptedly in sheds 
having the floor heated by fires ; but this can only be effected in districts where coal is 
cheap. The floors of these sheds are a series of tunnels or flues running through the shed 
longitudinally. At the lower end is a pit, in which are the furnaces ; the fire travels up the 
flues under the floor of the shed, giving off its heat by the way, and the smoke escapes at 
the upper end, through a series of (generally three or four) smaller chimneys or stacks. The 
furnace end of these flues would naturally be much more highly heated than the upper end 
near the chimneys. To remedy this, the floor is constructed of a greater thickness at the 
fire end, and gradually diminishes to within a short distance of the top. By this means, 
and by the assistance of dampers in the chimneys, it is kept at nearly an equal temperature 
throughout. Bricks that will bear rapid drying, such as are made from marly clays or very 
loamy or siliceous earths, will be fit for the kiln in from 12 to 24 hours. Before the duty 
was taken off bricks, much dishonesty was practised by unprincipled makers, where this 
drying could be carried on economically. Strong clays cannot be dried so rapidly. These 
sheds are generally walled round with loose bricks, stacked in between each post or pillar 
that supports the roof. The vapor given off from the wet bricks, rising to the roof, escapes. 
This system of drying is greatly in advance of that in the open air, for it produces the ware, 
as made, without any deterioration from bad weather ; but the expense of fuel to heat these 
flues has restricted its use to the neighborhood of collieries. In 1845 attention was turned 
to the drying of bricks, and experiments carried out in drying the ware with the waste heat 
of the burning kilns. The calorie, after having passed the ware in burning, was carried up 
a flue raised above the floor of the shed, and gave off its spent heat for drying the ware. 
Although this kiln was most useful in proving that the waste heat of a burning kiln is more 
than sufficient to dry ware enough to fill it again, it was abandoned on account of the con- 
struction of the kiln not being good. 

" Another system of drying is in close chambers, by means of steam, hot water, or by 
flues heated by fire under the chambers. I will, therefore, briefly describe the steam 
chamber, as used by Mr. Beart. This is a,- square construction or series of tunnels or cham- 
bers, built on an incline of any desired length ; and at some convenient spot near the lower 
end, is fixed a large steam boiler, at a lower level than the drying chamber. From the 
boiler the main steam pipe is taken along the bottom or lower end of the chamber, and from 
this main, at right angles, run branch pipes of four inches diameter up the chamber, two 
feet apart, and at about three feet from the top or arch. From there being so close and 
shallow a chamber between the heating surface of the pipes and the top, and so large an 
amount of heating surface in the pipes, the temperature is soon considerably raised. At 
the top and bottom ends are shutters or lids, which open for the admission of the green 
ware at the upper end, and for the exit of the dry ware at the lower end of the chamber. 
Over the steam pipes are fixed iron rollers, on which the trays of bricks, as brought from 
the machine, are placed, the insertion of one tra^ forcing the tray previously put in further 
on, assisted in its descent by the inclination of the construction. The steam being raised in 
the boiler flows through the main into those branch pipes in the chamber, and from the 
large amount of exposed surface becomes condensed, giving off its latent heat. From the 
incline given to the pipes in the chamber, and from the main pipe also having a fall 
towards the boiler, the whole of the warm water from the condensed steam flows to the 
boiler to be again raised to steam, sent up the pipes, and condensed intermittently. The 
steam entering at the lower end of the chamber, it is, of course, warmer than the upper 
end. Along the top end or highest part of the chamber is a series of chimneys and wind- 
guards, through which the damp vapor escapes. The bricks from the machine enter at this 
cooler end charged with warm vapor, and as the make proceeds are forced clown the cham- 
ber as each tray is put in. Thus, those which were first inserted reach a drier and warmer 
atmosphere, and, on their arrival at the lower end, come out dry bricks, in about 24 hours, 
with the strongest clays. In some cases the waste steam of the working engine is sent 
through these pipes and condensed. Bricks will dry soundly without cracking, &c, in these 
close chambers, when exposed to much greater heat than they would bear on the open flue 
first described, or the open air, from the circumstance of "the atmosphere, although very 
hot, being so highly charged with vapor. In practice, these steam chambers have proved 
many principles, but they are not likely to become universal, for they are very expensive 
in erection on account of the quantity of steam pipes, and involve constant expense in fuel, 
and require attention in the management of the steam boiler ; but their greatest defect ia 



the want of a current of hot air through the chamber to carry off the excess of vapor faster 
than is now done. The attaining a high degree of temperature in these chambers is useless, 
unless there is a current to carry off the vapor. Why should this piping be used, or steam 
at all, when we have a large mass of heat being constantly wasted, night and day, during 
the time the kilns are burning ? and after the process of burning the kiln is completed, we 
have pure hot air flowing, from 48 to 60 hours, from the mass of cooling bricks in the kilns, 
free from carbon or any impurities ; this could be directed through the drying chambers, 
entering in one constant flow of hot dry air, and escaping in warm vapor. The waste heat 
during the process of burning can be taken up flues under the chamber, and thereby all the 
heat of our burning kilns may be economized, and a great outlay saved in steam pipes, 
boilers, and attention. It must not be forgotten, also, that so large an atmospheric con- 
denser as the steam chamber is not heated without a considerable expenditure in fuel. This 
drying by steam is a great stride in advance of the old flued shed, but practical men must 
see the immense loss incurred constantly from this source of the spent heat of the burning 
kilns, and that by economizing it, an immense saving will be effected in the manufacture. 
The kilns are constructed as near the lower end of these chambers as convenient." 

Mr. Chamberlain must be again quoted on the burning of bricks : — " I will now more 
fully describe a principle of burning which I have had in practice for the last six years, and 
which I can therefore recommend with great confidence. The great object in brick-burning 
is to attain a sufficient heat to thoroughly burn the ware with as small a consumption of 
coal as possible ; and with nearly an equal distribution of the heat over all parts, so that the 
whole of the ware, being subjected to the same temperature, may contract equally in bulk, 
and be of one uniform color throughout. The advantage is also gained of burning in much 
less time than in the old kilns, which, on an average, took a week ; and the management is 
so simplified that any man, even though not at all conversant with the manufacture, after 
he has seen one kiln burnt, will be able to manage another ; and the last, though not least, 
advantage is, that of delivering up to us the waste heat at the ground level, or under the 
floor of the kiln, to be used in drying the green ware, or in partially burning the next kiln. 

"Hitherto the heat has been applied by a series of fire-places, or flues and openings 
round the kiln, each exposed to the influence of the atmosphere ; and in boisterous weather 
it is very difficult to keep the heat at all regular, the consequence of which is the unequal 
burning we often see. The improvements sought by experimentalists have been the burn- 
ing the goods equally, and, at the same time, more economically. These are obtained by 
the patent kilns, as improved by Mr. Robert Scrivener, of Shelton, in the Staffordshire Pot- 
teries. The plan is both simple and effective, and is as follows : — A furnace is constructed 
in the centre of the kiln, much below the floor level, and so built that the heat can be di- 
rected to any part of the kiln at the pleasure of the fireman. First, the heat is directed up 
a tube in the centre to the top of the oven or kiln, and, as there is no escape allowed to 
take place there, it is drawn down through the goods by the aid of flues in connection with 
a chimney. Thus, all the caloric generated in the furnace is made use of, and, being cen- 
tral, is equally diffused throughout the mass ; but, towards the bottom, or over the exit- 
flues, the ware would not be sufficiently burnt without reversing the order of firing. In 
order to meet this requirement, there is a series of flues under the bottom, upon which the 
goods are placed, with small regulators at the end of each ; these regulators, when drawn 
back, allow the fire to pass under the bottom, and to rise up among the goods which are not 
sufficiently fired, and thus the burning is completed. By means of these regulators the heat 
may be obtained exactly the same throughout ; there is, therefore, a greater degree of cer- 
tainty in firing, and a considerable saving of fuel, with the entire consumption of the smoke. 
From the fire or draught being under command, so as to be allowed either to ascend or 
descend through the ware during the time of burning or cooling, the waste caloric can be 
economized and directed through the adjoining kiln in order to partially burn it, or be used 
in drying off the raw wares on flues or in chambers. I have found the saving of fuel in 
these kilns, over the common kiln, 50 per cent. ; and to give an idea of the facility with 
which they can be worked, it is common for my men to fill the kiln, burn, cool, and dis- 
charge it in six days." — Chamberlain. 

There are numerous machines in use for the manufacture of bricks. For the manufac- 
ture of perforated bricks, Mr. Beart's machine is the most generally employed. Mr. Cham- 
berlain thus describes it : — " The most universally used die machine which has been exten- 
sively worked up to the present time is Mr. Beart's patent for perforated bricks. This gen- 
tleman, whois practically acquainted with these matters, in order to remedy the difficulties 
I have mentioned in expressing a mass of clay through a large aperture or die, hung a series 
of small tongues or cores, so as to form hollow or perforated bricks. By this means the 
clay was forced in its passage through the die into the corners, having the greater amount 
of friction now in the centre. Still, the bricks came out rough at the edge with many clays, 
or with what is termed a jagged edge. The water die was afterwards applied to this ma- 
chine, and the perforated bricks, now so commonly used in London, are the result. In Mr. 
Beart's machine, whicl^s a pug-mill, the clay is taken after passing through the rolling-mill, 
Vol. III. — 14 



and, being fed in at the top, is worked down by the knives. At the bottom are two horizon- 
tal clay-boxes, in which a plunger works backwards and forwards. As soon as it has reached 
the extremity of its stroke, or forced the clay of one box through the die, the other box re- 
ceiving during this time its charge of clay from the pug-mill, the plunger returns and emp- 
ties this box of clay through a die on the opposite side of the machine. The result is that 
while a stream of clay is being forced out on one side of the machine, the clay on the oppo- 
site side is stationary, and can, therefore, be divided into a series of five or six bricks with 
the greatest correctness by hand. Some of these machines have both boxes on one side 
and the plungers worked by cranks. Tins machine cannot make bricks unless the clay has 
previously passed through rollers, if coarse ; for any thing at all rough, as stone or other 
hard substance, would hang in the tongues of the die. But the clay being afterwards 
pugged in the machine, is so thoroughly tempered and mixed, that the bricks, when made, 
cannot be otherwise than good, provided they are sufficiently fired. As to the utility of 
hollow or perforated bricks, that is a matter more for the consideration of the architect or 
builder than for the brick-maker. Perforated bricks are a fifth less in weight than solid 
ones, which is a matter of some importance in transit ; but it takes considerably more power 
to force the clay through those dies than for solid brick-making. In the manufacture of 
perforated bricks, there is also a royalty or patent right to be paid to Mr. Beart." 


Mr. Chamberlain's own machine is in principle as follows {fig. 87a) : — The clay is fed 
into a pug-mill, placed horizontally, which works and amalgamates it, and then forces it off 
through a mouth-piece or die of about 65 square inches, or about half an inclrdeeper, and 
half an inch longer than is required for the brick, of a form similar to a brick on edge, but 
with corners well rounded off, each corner forming a quarter of a 3-inch circle, for clay will 
pass smoothly through an aperture thus formed, but not through a keen angle. After the 
clay has escaped from the mill, it is seized by four rollers, covered with a porous fabric, 
(moleskin,) driven at a like surface speed from connection with the pug-mill. These rollers 
are two horizontal and two vertical ones, having a space of 45 inches between them ; they 
take this larger stream of rough clay, and press or roll it into a squared block, of the exact 
size and shape of a brick edgeways, with beautiful sharp edges, for the clay has no friction, 
being drawn through by the rollers instead of forcing itself through, and is delivered in one 
unbroken stream. The rollers in this machine perform the functions of the die in one class 
of machinery, and of the mould in the other. They are, in fact, a die with rotating sur- 
faces. By hanging a series of mandrels or cores between these rollers, or by merely chang- 
ing the mouth-piece, we make hollow and perforated bricks, without any alteration in the 

Messrs. Bradley and Craven, of Wakefield, have invented a very ingenious brick-making 
machine : — 

It consists of a vertical pug-mill of a peculiar form, and greatly improved construction, 
into the upper part of which the clay is fed. In this part of the apparatus the clay under- 
goes a most perfect tempering and mixing, and, on reaching the bottom of the mill, thor- 
oughly amalgamated, is forcibly pressed into the moulds of the form and size of brick re- 
quired, which are arranged in the form of a circular revolving table. 




As this table revolves, the piston-rods of the moulds ascend an incline plane, and grad- 
ually lift the bricks out of the moulds, whence they are taken from the machine by a boy, 
and placed on an endless band, which carries the bricks direct to the waller, thus effecting 
the saving of-the floor room. 

The speed of the several parts of the machine is so judiciously arranged, that the opera- 
tions of pugging, moulding, and delivering proceed simultaneously in due order, the whole 
being easily driven by a steam engine of about six-horse power, which, at the ordinary rate 
of working, will make 12,000 bricks per day ; or, with eight-horse power, from 15,000 to 

In consequence of the perfect amalgamation of the clay, and the great pressure to which 
it is subjected in the moulds, the bricks produced by this machine are perfect ; and from 
the stiffness of the clay used, less water has to be evaporated in the drying, thus saving one- 
half the time required for hand-made bricks, and avoiding the risk of loss from bad weather. 

A very ingenious and simple brick-making machine was constructed and patented by 
Mr. Roberts, of Falmouth, and it has been extensively worked by him in the parish of Mjlor. 

Fig. 89 shows a plan of machinery combined, according to Mr. Roberts's invention, and 
fig. 90 shows a side elevation, partly in section, a is a circular track, on which are fixed 
series of moulds, b, at intervals, the form of moulds being according to the shape of bricks 
or tiles to be made. Each set of moulds is provided with movable bottoms, (one for each 
mould,) which are connected to the bar, c, so that they may be all simultaneously lifted by 
the lever, d. 

la. fig. 90, one set of the moulds and apparatus used therewith is shown, and the several 
sets of moulds (the positions of which are in the drawing,^. 89) are similarly provided. 
e is a roller, which is moved round on the track, a, by means of the frame, /, which receives 
motion from a steam-engine or other power, by means of the shaft, g, the cog-wheel, h, and 
circular-toothed rack fixed on the frame,/. The olay, or brick earth, is filled into the 
moulds, and the roller, e, presses the same intomthe moulds as it rolls over them ; i is a 
scraper which, following the roller, e, removes smy excess of clay or brick earth from the 
moulds ; andj is a smaller roller, which acts as a balance, to prevent the cutter from rising-, 
k is a pressing plate attached to the bar, c, and is raised at the same time by the lever, d. 
The roller, e, in its further progress, passes over and presses down the plate, k, which com- 
pletes the pressure ; e then passes on and presses down the lever, d, by which all the mov- 
able bottoms of the moulds will be raised with the bricks or tiles thereon. The whole of 
the pistons and bar, c, are kept up by the stop, I, which works by a spring, and is removed 
by the treadle, ??i, as soon as the bricks or tiles are taken away ; n are small rollers, fixed 
to the frame, o, to which the cutter or scraper is attached. 



For the analyses of the clays of which these and others are constructed, see Clay. 
Stone Bricks. — These are manufactured at Neath, in Glamorganshire, and are very 
much used in the construction of copper furnaces at Swansea. 

The materials of which the bricks are made are brought from a quarry in the neighbor- 
hood. They are very coarse, being subjected to a very rude crushing operation under an 
edge stone, and, from the size of the pieces, it is impossible to mould by hand. There are 
three qualities, which are mixed together with a little water, so as to give the mass co- 
herence, and in this state it is compressed by the machine into a mould. The brick which 
results is treated in the ordinary way, but it resists a much greater heat than the Stour- 
bridge clay brick, expands more by heat, and does not contract to its original dimensions. 
The composition of the three materials is as follows : — 

From Pendreyn. From Dinns. 

Silica 94-05 - - 100' 91'95 

Alumina, with a trace of ox. iron 4-55 - - traces 8 '05 
Lime and magnesia - traces traces 

98-60 100- 100-00 

— Dr. Richardson : Knapp's Technology. 
In immediate connection with this subject, it appears that the following machine for 
raising bricks, mortar, &c, by M. Pierre Journet, described to the London Institution of 
Civil Engineers, merits attention. It is a machine for raising bricks and materials to pro- 

BKONZE. 213 

gresive heights in the building of chimneys and other works. A strong frame on the 
"round contained the winch wheel, and on the second motion a notched wheel ; on the 
scaffold frame above is a similar notched wheel, and round these two wheels an endless chain 
travels, made of flat links and cross pins, which are held by the notches in the wheels. The 
buckets for mortar, and hods for bricks, are hooked upon these transverse pins, and are 
raised, by the winch motion below, to the landing above ; the bricks are removed by labor- 
ers, and empty buckets and hods hung to the descending chain, to be detached and filled 

It appeared that a working rate of 15 feet in a minute for the chain to travel was a con- 
venient rate for the men. One man turning the winch will raise — 

10 feet high 90 bricks per minute, or = 5400 bricks per hour. 




u s 

' = 2700 




a i 

' = 1800 




a i 

' = 1350 




U l 

' = 1080 




U l 

1 = 900 

As the work increases, the scaffold is elevated, and the chain lengthened, adding more hods. 

The great advantages are, that the men are relieved from the labor of climbing ladders 
and risk of accidents, that the building is carried on quicker, and therefore at less cost. 
The plan was adopted with success at the large buildings at Albert Gate, Hyde Park, and at 
the new Houses of Parliament. 

Steam power, of course, can be employed ; and a great practical advantage arises from 
not encumbering the building with the weight of ladders, and materials collected on the 

BROMINE. (Br. Atomic weight, 80. Density in liquid state, 2 - 97. Density of vapor 
by experiment, 5-39 ; calculation on supposition of the density of hydrogen being 
0-0692,5-536.) One of the most active of the elements. It was discovered in 1826, by 
Balard, of Montpellier, in the bittern produced from the water of the Mediterranean. Bro- 
mine is a very interesting substance, and its discovery has had great influence on the pro- 
gress of theoretical and applied chemistry. It is the only element, save mercury, which 
exists in the fluid state at ordinary temperatures. It is found not only in sea water, but in 
numerous saline springs. It also exists in combination with silver and chlorine in some 
Mexican and Chilian minerals. 

Preparation 1. From bittern. — Chlorine gas is passed in for some time ; this has the 
effect of combining with the metallic base of the bromide present, the bromine being, in 
consequence, liberated. When the bittern no longer increases in color, the operation is 
suspended, or chloride of bromine would be formed, and spoil the. operation. The colored 
fluid is placed in a large globe, with a neck having a glass stopcock below like a tap funnel, 
the upper aperture being closed with a stopper. Ether is then added, the stopper replaced, 
and the whole well agitated. After a short repose, the ether rises to the surface retaining 
the bromine in solution. The stopper being removed to permit the entrance of air, the 
stopcock is opened, and the aqueous fluid is permitted to run out. As soon as the highly 
colored etheral solution arrives at the aperture in the stopcock, the latter is shut ; a quan- 
tity of solution of potash is then poured, by the upper aperture, into the globe, and the 
stopper is replaced. The whole is now to be agitated, by which means the bromine com- 
bines with the potash, forming a mixture of bromate of potash and bromide of potassium. 
The stopcock is again opened, and the aqueous fluid received into an evaporating vessel, 
boiled to dryness, and ignited. By this means the bromate of potash is all converted into 
bromide of potassium. The bromine may be procured from the bromide of potassium by 
distillation with peroxide of manganese and sulphuric acid. In this operation one equiv- 
alent of bromide, two equivalents of sulphuric acid, and one of peroxide of manganese, 
yield one equivalent of sulphate of manganese, one of sulphate of potash, and one of bro- 
mine ; or, in symbols, KBr -+- 2S0 3 -f- MnO 2 = KO, SO 3 + MnO, SO 3 + Br. The reac- 
tion, in fact, takes place in two stages, but the ultimate result is as represented in the 

Preparation 2. — In some saline springs where bromine is present, accompanied by con- 
siderable quantities of salts of lime, &c, the brine may be evaporated to one-fourth, and, 
after repose, decanted or strained from the deposit. The mother liquid is to have sulphuric 
acid added, in order to precipitate most of the lime. The filtered fluid is then evaporated 
to dryness, redissolved in water, and filtered ; by this means more sulphate of lime is got 
rid of. The fluid is then distilled with peroxide of manganese and hydrochloric acid. 

The only well-developed oxide of bromine is bromic acid, BrO 5 . Solutions of bromine 
in water may have their strength determined, even in presence of hydrochloric or hydro- 
bromic acids, by means of a solution of turpentine in alcohol. One quarter of an equivalent 
of turpentine (34 parts) decolorizes 80 parts or 1 equivalent of bromine. — C. G. W. 

BRONZE. {Bronze, Fr. ; Bronze, Germ.) A compound metal consisting of copper 
and tin, to which sometimes a little zinc and lead are added. There is some confusion 

214 BEONZE, 

amongst continental writers about this alloy ; they translate their bronze into the English 

See, for an example of this, " Dictionnaire des Arts et Manufactures." This has arisen 
from the carelessness of our own writers. Dr. Watson, " Chemical Essays," remarks : "It 
has been said that Queen Elizabeth left more brass ordnance at her death than she found 
iron on her accession to the throne. This must not be understood as if gun metal was made 
in her time of brass, for the term brass was sometimes used to denote copper ; and some- 
times a composition of iron, copper, and calamine was called brass ; and we, at this day, 
commonly speak of brass cannon, though brass does not enter into the composition used 
for casting cannon." 

Bronze is an alloy of copper and tin. 
Brass is an alloy of copper and zinc. 

In many instances, we have zinc, lead, &c, entering into the composition of alloys of 
copper and tin. However this may be, the alloy is called a bronze, if tin and copper are 
the chief constituents. 

This alloy is much harder than copper, and was employed by the ancients to make 
swords, hatchets, &c, before the method of working iron was generally understood, The 
art of casting bronze statues may be traced to the most remote antiquity, but it was first 
brought to a certain degree of refinement by Theodoros and Rcecus of Samos, about 700 
years before the Christian era, to whom the invention of modelling is ascribed by Pliny. 
The ancients were well aware that by alloying copper with tin, a more fusible metal was 
obtained, that the process of casting was therefore rendered easier, and that the statue was 
harder and more durable. It was during the reign of Alexander that bronze statuary re- 
ceived its greatest extension, when the celebrated artist Lysippus succeeded, by new pro- 
cesses of moulding and melting, in multiplying groups of statues to such a degree that 
Pliny called them the mob of Alexander. Soon afterwards enormous bronze colossuses 
were made, to the height of towers, of which the isle of Ehodes possessed no less than one 
hundred. The Eoman consul Mutianus found 3,000 bronze statues at Athens, 3,000 at 
Rhodes, as many at Olympia and at Delphi, although a great number had been previously 
carried off from the last town. 

From the analyses of Mr. J. A. Phillips, we learn that most of the ancient coins were 
bronzes, the quantity of tin relatively to the copper varying slightly. The proportions of 
copper and tin in many of those coins are given below, the other ingredients being 
omitted : — 

Copper. Tin. 

A coin of Alexander the Great, 335 b. c. - 86 - 72 - - 13-14 

" PhillipusV. - 200 B. C. - - 85-15 - - 11-10 

" Atheris 88-41 - - 9-95 

" Ptolemy IX. - - 70 b. c. - - 84-21 - • 15-59 
" Pompey - - 53 b. c. - - 74-11 - - 8"5& 

" the Atilia family - 45 b. c. - - 68-72 - - 4-77 
" Augustus and Agrippa, 30 b. c. - - 78-58 - - 12-91 

The arms and cutting instruments of the ancients were composed of similar bronzes, 
as the following proportions, also selected from Mr. J. A. Phillips's analyses, will show : — 

Copper. Tin. 

Eoman sword blade, found in the Thames - - 85-70 - - 10-02 

" / " " Ireland - - 91-39 - - 8-38 

Celtic " " Ireland - - 90-23 - - 7-50 

Layard brought from Assyria a considerable variety of bronze articles, many of them 
objects of ornament, but many evidently intended for use. Amongst others was a bronze 
foot, which was constructed for the purpose of support of some kind. This was submitted 
to the examination of Dr. Percy. It was then found that the bronze had been cast round a 
support of iron. By this means the appearance of considerable lightness was attained, while 
great strength was insured. This discovery proves, in a very satisfactory manner, that the 
metallurgists of Assyria were perfectly conversant with the use of iron, and that they em- 
ployed it for the purpose of imparting strength to the less tenaceous metals which they em- 
ployed in their art manufactures. This bronze, as analysed in the Metallurgical Laboratory 
of the Museum of Practical Geology, consists of copper 88-37, tin 11-33. 

Examination has shown that all the bronze weapons of the Greeks and Romans were not 
only of the true composition for ensuring the greatest density in the alloy itself, but that 
these, by a process of hammering the cutting edges, were brought up to the greatest degree 
of hardness and tenacity. 

Before 1542 "brass ordnance" (bronze) was founded by foreigners. Stow says that 
John Owen began to found brass ordnance, and that he was the first Englishman who ever 
made that kind of artillery in England. 

Bell founding followed. Bell metal and other broken metal were allowed to be ex- 



ported hitherto ; but it being discovered that it was applied to found guns abroad, " brass, 
copper, latten, bell metal, pan metal, gun metal, and shroff metal are prohibited to be ex 


Bronze has almost always been used for casting statues, basso relievos, and works which 
were to be exposed to atmospheric influences. In forming such statues, the alloy should be 
capable of flowing readily into all the parts of the mould, however minute ; it should be 
hard in order to resist accidental blows, be proof against the influence of the weather, and 
be of such a nature as to acquire that greenish oxidized coat upon the surface, which is so 
much admired in the antique bronzes, called patina antiqua. The chemical composition 
of the bronze alloy is a matter, therefore, of the first moment. The brothers Keller, cele- 
brated founders in the time of Louis XIV., whose chefs-d'oeuvre are well known, directed 
their attention towards this point, to which too little importance is attached at the present 
day. The statue of Desaix, in the Place Dauphine, and the column in the Place Vendome, 
are noted specimens of most defective workmanship from mismanagement of the alloys of 
which they are composed. On analyzing separately specimens taken from the bass-reliefs 
of the pedestal of this column, from the shaft, and from the capital, it was found that the 
first contained only 6 per cent, of tin, and 94 of copper, the second much less, and the third 
only 0-21. It was therefore obvious that the founder, unskilful in the melting of bronze, 
had gone on progressively refining his alloy, by the oxidizement of the tin, till he had ex- 
hausted the copper, and that he had then worked up the refuse scoria3 in the upper part of 
the column. The cannon which the Government furnished him for casting the monument 
consisted of: — 

Copper ' 89-360 

Tin 10-040 

Lead 0-102 

Silver, zinc, iron, and loss ------ 0-498 

For the following table we are indebted to "Mr. Robert Mallet, C. E., whose investiga- 
tions in this direction have been most extensive, and as accurate as they are extensive : — 




by Weight 
per cent. 

* # 

Color of Fracture. 

O J3 

Q £ 

CD 3 






5 E 

o | 

£ fa 

Commercial Titles, 

characteristic Properties 

in working, &c. 






5 & 




Cu + Sn 

100-00+ 31-6 8-667 

Tile red - 








lOCa + Sn 

S4-29+ 15-71 3749 8 561 


Eeddish yellow, 1 






Gun metal, &c. 


9 Cu+Sn 

82-S1+ '17-19:343-3 S-462 


Eeddish yellow, 2 









SI -10+ 18-90 311-7 S-459 



Yellowish red, 2 






Gun metal, tempers 

Hard mill brasses, 




7S-97+ 21-03 280-1 8-72S 


Yellowish red, 1 








76-29+ 23-T124S-5 8-750 


Bluish red, 1 







72-80+ 27-20 ! 216-9 8-575 

Bluish red, 2 - 








68-21+ 31-79.185-3 S-400 


Ash gray - 








61-69+ 88-31 153-7 8-539 


Dark eray - 







2Cu + Sn 

51-75+ 4S-25;1221 8-416 


Grayish white, 1 







Cu + Sn 

34-92 + 65-03: 90-5 8056 


Whiter still, 2 





Small bells, brittle.t 



21-15+ 73-S51149-4 7 387 



Ditto 3 





Ditto brittle.t 
Speculum : — 



1517+ 84S3 1208-3 7-447 


Ditto 4 





Metal of authors. 



11-82+ 83-18:267-2 7472 


Ditto 5 






Files, tough. 



9-68+ 90-32 32G-1 7^442 


Ditto 6 






Files, soft and 


+ Sn 

0-00 +100-001 58-9 7-291 


White, 7 - 






In 1856, we imported, of Bronze, works of art, 21 cwts. ; and of manufactures of bronze, 
or of metal bronzed or lacquered, 3,492 cwts. 

BRONZING-. The process for giving to metals, plaster, wood, or any other body, a 
bronze-like surface. 

Various processes have been adopted for producing this effect. 

When brass castings are to be bronzed, it is essential, in the first place, that they should 
be thoroughly cleansed from grease, and brightened either with the file or emery-paper, or 
by boiling in a strong lye and then scouring with fine sand and water. 

Vinegar alone is sometimes employed to produce the green bronze color ; sometimes 
dilute nitric acid, and often the muriate of ammonia, (sal ammoniac.) This latter salt and 

* E signifies earthy ; c c, coarse crystalline ; F o, fine crystalline ; o, conchoidal; v, vitreous; V 0, 
vitreous-conchoidal ; T c, tabular crystalline. 

t All these alloys are found occasionally in bells and specula with mixtures of Zn and Pt>. 


vinegar are frequently combined, and often a little common table salt is added to the bronz- 
ing fluid. 

The best and most rapid bronzing liquid, which may be applied to copper, brass, iron, 
or to new bronze, with equal advantage, is a solution of the chloride of platinum (nitro- 
muriate of platinum) called chemical bronze ; but it is expensive. With the chloride of 
platinum, almost any color can be produced, according to the degree of dilution, and the 
number of applications. 

Some beautiful effects are produced upon bronze, and also upon iron castings, by treat- 
ing them with dilute acids. The action here is scarcely to be described as bronzing ; it is, 
in fact, merely developing the true color of the metal or alloy. 

With the view of rendering the action of the bronzing liquid as uniform as possible, 
small articles are dipped ; for larger articles, the bronzing liquid is dabbed on plentifully 
with a linen rag. The dabbing process is to prevent the occurrence of streaks, which might 
arise if the liquid was applied in straight strokes. When properly bronzed and washed, the 
work is usualy black-leaded, to give it a polished appearance. 

BRONZE POWDERS have been much used of late in the decorative painting of houses, 
&c. They are prepared of every shade, from that of bright gold to orange, dark copper, 
emerald green, &e. Pale gold is produced from an alloy of IS J of copper, and 2f of zinc ; 
crimson metallic lustre — from copper : ditto, paler, copper and a very little zinc ; green 
bronze, with a proportion of verdigris ; another fine orange by 14^ copper and l| zinc ; 
another ditto, 13f copper and 2£ zinc : a beautiful pale gold from an alloy of the two metals 
in atomic proportions. 

The alloy is laminated into very fine leaves with careful annealing, and these are levi- 
gated into impalpable powders along with a film of fine oil to prevent oxidizement, and to 
favor the levigation. 

On the subject of bronze powders and metallic leaves, Mr. Brandeis furnished to the 
New York Exhibition an account of his articles of manufacture : — 

Bronzes, or, more correctly, metallic powders resembling gold dust, were invented, ac- 
cording to my researches, in 1648, by a monk, at Purth, in Bavaria, named Theophrastus 
Allis Bombergensis. He took the scraps or cuttings of the metallic leaves then known as 
" Dutch leaf," and ground them with honey. This roughly made bronze powder was used 
for ornamenting parchments, capital letters in Bibles, choral books, &c. 

As the consumption of metallic leaf increased, and the properties of alloys became bet- 
ter known, leaves of different colors were produced, and from the scraps a variety of pow- 
ders or bronzes. 

At Furth, bronze powders are largely made for Europe, and with little change or im- 
provement. There are JWir sorts of Dutch leaf : 

Common leaf, soft, and of a reddish cast, composed of 25 or 30 per cent, of zinc to 75 
or ^0 per cent, of copper. 

French leaf contains more zinc, is harder, less ductile, and has a purer yellow color. 

Florence leaf has a larger proportion of zinc, and is of a greenish gold color ; and 
lastly — 

White leaf composed of tin. The more zinc these alloys contain, the harder, the more 
brittle, and more difficult are they to work into perfect leaves. The manner of beating is 
similar to the mode for producing gold leaves. 

The scraps, cuttings, and fragments of these leaves are the materials for the German 
bronze powders. First brushed through a sieve and ground with gum water on marble 
slabs for six hours, the gum washed out, the powders sorted, dried, and a coating of grease 
given to make them appear more brilliant, and to protect them from oxidation. Varieties 
of color, such as orange, &c, are produced by a film of suboxide upon the surface of the 
particles. The price of bronze powders depends upon the demand, and the supply of the 
waste material of the metal leaves, and prices change accordingly. 

Messrs. Brandeis patent their process, and in place of being dependent upon uncertain 
supplies of metal and unknown composition, they take the metals at once in a state of pu- 
rity, (say copper by voltaic precipitation :) it is alloyed with zinc, cast into ingots, rolled into 
ribands, cut, annealed, and rolled until the metal is thin and leaf-like ; then it is taken to a 
steam-mill, and ground. The bronze powder is washed out and dried, then introduced into 
an air-tight room, with an' arrangement of boxes ; the air of the chamber is set in violent 
motion by bellows, and the powder diffused throughout ; the bronze powders are deposited, 
the finest in the upper boxes, and the coarser powders below. When settled, mineral var- 
nish is introduced ; the boxes, fitted with tight lids, are made to revolve, and the particles 
are thus rapidly coated, and the highest metallic brilliancy imparted. Different shades of 
color, pink, crimson, &c, are produced by submitting the powder to heat and oxidation 
before the rapid revolutions of the varnishing boxes. 

The quantity thus produced by one firm, with three steam-engines at work, enables the 
finished bronze powders to be produced at a rate about equal to the price the German 
manufacturer has to pay for his materials — the cuttings and scraps of leaves. Hence, for 



the purposes of trade and art, a large exportation of bronze powders takes place from 
America to Europe, South America, and China. 

The bronze powders are largely used in japanning, bronzing tin and iron goods, orna- 
mental works of paper, wood, oil-cloth, leather, &c. ; while sign-boards and the decoration 
of public buildings have effective metallic brilliant surfaces of beauty and durability. In 
fact, for ornamental decorations, the demand steadily increases. 

in Holland and Germany the subject has been examined, with the view of ascertaining 
the effect of chemical composition. 

De Heer E. R. Konig has lately given a table of the analyses of the best European sam- 
ples of bronze powders and leaves, ( Vblksfiight .-) — 





Per cent. 

Per cent. 

Per cent. 

Per cent. 

1. Light yellow 




2. Gold yellow 




3. Messing yellow, or brass copper red-yel- 

low color 




4. Copper bronze orange - - - - 




5. Copper red, high shade of purple color 




6. Purple violet 





7. Light green 





8. Tin white or leaden gray 





Our importations in 1856 of Bronze Powders were valued at £i, > iZ1, according to the 
Custom House computation. 

BROWN COAL is of a brownish-black color, and presents, in some cases, the texture 
of wood, when it is called Lignite ; but, in some varieties, all organic structure has disap- 
peared, and it is then called pitch coal, from its strong resemblance to true coal. 

The beds of brown coal are generally of small extent, and are of later date than the true 
carboniferous strata, belonging to the Tertiary period. 

Brown coal is worked in Saxony and in countries where there is an absence of true car- 
boniferous deposits. It burns with an empyreumatic odor, and generally contains more 
pyrites than ordinary coal. 

At Steieregg, in Southern Styria, brown coal occurs in the form of a basin ; and has 
been opened out through a distance of more than two miles. The coal, from 8 to 16 feet 
thick, is of good quality. It contains 9 to 14 per cent, of "water, and leaves from 5 to 12 
per cent, of ash after combustion. 

The following is an analysis of a variety from Oregon : volatile matter, 49 5 ; fixed car- 
bon, 42-9 ; ash, 2"7 ; water, 4-9 = 100-00. 

A variety of brown coal, called the paper-coal of Rott, near Bonn, and of Erpel on the 
Rhine, contains numerous remains of freshwater fishes, Leuciscus papyraceus ; and of frogs, 
Palmophrygnos grandipies. The ashes of this coal are, also, rich in infusorial remains. 

For an account of the brown coals of this country, see Lignite and Boghead Coal. — 
H. W. B. 

BROWN IRON ORE (or Limonite) is one of the most important ores of iron, and, at 
the same time, one of the most abundant as well as most widely diffused. It never occurs 
crystallized, but usually in stalactitic, botryoidal, and mammillated forms, with a fibrous 
structure, a silky lustre, and often a semi-metallic appearance ; it also occurs massive and 
sometimes earthy. In color it is of various shades of brown, generally dark, never bright. 
It affords a brownish-yellow streak, which distinguishes it from other ores of the same metal. 
It dissolves in warm nitro-muriatic acid, and in a matrass gives off water. Before the blow- 
pipe it blackens and fuses, when in thin splinters ; with borax, it gives an iron reaction. 
H = 5 to 5-5 ; specific gravity = 3-6 to 4. Brown iron ore is a hydrated peroxide of iron, 
composed of peroxide of iron, 85-6, and water, 14-4 = 100-0 ; but it frequently contains 
small percentages of silica, alumina, &c. 

The principal varieties of this ore are brown hematite, comprising the compact and 
mammillary varieties, scaly and ochry brown iron ore, yellow ochre constituting the decom- 
posed earthy varieties, which are often soft, like chalk. Bog iron ore and clay iron stone 
are sometimes classed under this head, but it appears to us, especially as it regards the lat- 
ter, improperly. The hydrated oxides of Northamptonshire and Bedfordshire may with 
propriety be called brown iron ore. 

_ Brown iron ore is found in Cornwall, in the carboniferous limestone at Clifton, near 
Bristol, and in the Forest of Dean ; in Shetland, Carinthia, Bohemia, Siegen near Bonn, 
Villa Rica in the Brazils, and Peru. 

Brown Hematite occurs at Talcheer, in the Bengal coal-bearing strata, which are prob- 
ably of Permian age. It is smelted with the charcoal made on the spot, and produces iron 


of excellent quality. According to the calculations of Professor Oldham, it takes 2^ tons 
of charcoal to produce 1 ton of iron. — H. W. B. See Iron. 

BRUCINE. (C 4e H' 26 N'-0 8 ; syn. Canimarine, Vornicine.) A very bitter and poisonous 
alkaloid accompanying strychnine in mix vomica and in the false angustura bark, (Brucia 
antidysenterica. ) 

BRYLE or BROIL. A mining term. The loose matters found in a lode near the surface 
of the earth ; probably a corruption of Beuiieyl, {which see.) 

BRUSH WHEELS. In light machinery, wheels are sometimes made to turn each 
other by means of bristles fixed in their circumference ; these are called brush wheels. The 
term is sometimes applied to wheels which move by their friction only. 

BUCKING. A mining term. Bruising of the ore. A bitching iron is a flat iron fixed 
on a handle, with which the ore is crushed ; and a bucking plate is an iron plate on which 
the ore is placed to be crushed. 

BUCKTHORN. (Rhamnus cat/iarticus.) This plant is a native of England ; it grows 
to the height of from 15 to 20 feet ; its flowers are greenish colored, and its berries four- 
seeded. It is the fruit of this plant which is sold under the name of French berries. The 
juice of these, when in an unripe state, has the color of saffron ; when ripe, and mixed with 
alum, it forms the sap-green of the painters ; and in a very ripe state, the berries afford a 
purple color. The bark also yields a fine yellow dye. 

BUCKWHEAT. (Ble Sarrasin, Fr. ; Buchweizen, Germ.) The common buckwheat 
(Polygonum fagopyrum, from poly, many, and gonu, a knee, in reference to its numerous 
joints) is cultivated for feeding pheasants and other game ; and is now being largely used 
in France and in this country in distilleries. 

" In France, besides being used for feeding fowls, pigs, &c, it is given to horses ; and it 
is said that a bushel of its grains goes further than two bushels of oats, and, if mixed with 
four times its bulk of bran, will be full feeding for any horse for a week. Its haulm, or 
straw, is said to be more nourishing than that of clover, and its beautiful pink or reddish 
blossoms form a rich repast for bees." — Bauson. 

It has been stated that the leaves of the common buckwheat (Polygonum fagopyrum') 
yield, by fermentation, Indigo blue. On examining this plant, for the purpose of ascertain- 
ing whether this statement was correct, Schunek was unable to obtain a trace of that coloring 
matter, but he discovered that the plant contains a considerable quantity of a yellow coloring 
matter, which may very easily be obtained from it. This coloring matter crystallizes in 
small primrose-yellow needles. It is very little soluble in cold water, but soluble in boiling 
water, and still more soluble in alcohol. Muriatic and sulphuric acid change its color to a 
deep orange, the color disappearing on the addition of a large quantity of water. It dis- 
solves easily in caustic alkalies, forming solutions of a beautiful deep yellow color, from 
which it is again deposited in crystalline needles on adding an excess of acid. It is, how- 
ever, decomposed when its solution in alkali is exposed for some time to the air, being 
thereby converted into a yellowish-brown amorphous substance, resembling gum. Its com- 
pound with oxide of lead has a bright yellow color, similar to that of chromate of lead. The 
compounds with the oxides of tin are of a pale but bright yellow color. On adding proto- 
sulphate of iron to the watery solution, the latter becomes greenish, and, on exposure to the 
air, acquires a dark green color, and appears almost opaque. The watery solution imparts 
to printed calico, colors, some of which exhibit considerable liveliness. Silk and wool do 
not, however, acquire any color when immersed in the boiling watery solution, unless they 
have previously been prepared with some mordant. The composition of this substance in 
100 parts is as follows : — carbon, 50'00, hydrogen, 5 - 55, oxygen, 44-45. Its formula is 
probably C 30 H 2O O 20 . It appears, to be identical with Ruline, the yellow coloring matter 
contained in the Ruta graviolens, or common rue, and in capers ; and with Ilixanthim, a 
substance derived from the leaves of the common holly. From 1,000 parts of fresh buck- 
wheat leaves, a little more than 1 part of the coloring matter may be obtained. As the 
seed of the plant is the only part at present employed, it might be of advantage to collect 
and dry the leaves, to be used as a dyeing material. — E. S. 

The Tartarian Buckwheat (Polygonum Tartarium) differs from the former in having the 
edges of its seeds twisted. It is not considered so productive, but it is more hardy, and 
better adapted for growing in mountainous situations. 

The Dyers' Buckwheat. (Polygonum tinctorium.) This plant was introduced to the 
Royal Gardens at Kew by Mr. John Blake, in 1*776. Authentic information as to its 
properties as a dye-yielding plant was only received at a comparatively recent period, from 
missionaries resident in China, where it has always been cultivated for its coloring matter. 
In Europe, attention was first directed to its growth by M. Delile, of the Jardin du Roiat 
Montpellier, who, in 1835, obtained seeds from the Baron Fischer, Director of the Imperial 
Gardens at St. Petersburg. It has since that time become sufficiently valuable to render its 
cultivation as a dye drug of sufficient importance. The Japanese are said to extract blue 
dyes from Polygonum Chinensis, P. barbatum, an 1 ! the common roadside weed, P. avicu- 
lare. — Lawson. 

CABLE. 219