Iddings

Therese Pollet de la Comte Pocatiere, who bore
him two children.

[Iberville's campaigns were described by P. F. X.
Charlevoix, Hist, and Gen. Description of New France
(6 vols., 186^72), tr. by J. G. Shea. Claude Chas. Le
Roy Bacqueville de la Potherie, Hist, de I'Amerique
Septentrionale (4 vols., 1722), describes the expedi-
tion of 1697 of which he was a member. Pierre Margry,
Decouvertes et Stablissements des Fran^ais dans
I'Amerique Septentrionale, vols. IV-VI (1880-86),
gives the documents relating to the founding of Louisi-
ana.. C. B. Reed, The First Great Canadian (1910) is
the best modern biography. An excellent sketch is in
T. J. Campbell, Pioneer Laymen of North America
(1915), vol. II. See also A. C. G. Desmazures, Hist,
du Chevalier d'Iberville, 1663-1706 (1890); Chas. E.
A. Gayarre, Hist, of La. (1854), vol. I; "Voyage
D'Iberville," Quebec Lit. and Hist. Soc. Manuscripts,
3 ser. (1871).] L.P.K.

IDDINGS, JOSEPH PAXON (Jan. 21,1857-
Sept. 8,1920), geologist, petrologist, son of Wil-
liam Penn and Almira (Gillet) Iddings, was
born in Baltimore, Md. The Iddings family de-
scended from Richard Iddings, a Quaker who
came to America late in the seventeenth century
and died in Chester County, Pa., in 1726. When
Joseph was about ten years of age, his parents
moved to Orange, N. J., where he was taught in
a select private school. He manifested a fond-
ness for natural history subjects at an early age
and when about twelve formed with his class-
mates a "natural history society." He gradu-
ated in 1877 w^h the degree of Ph.B. from the
Sheffield Scientific School of Yale University.
His early interests were in the direction of min-
ing, but be turned naturally to petrology through
his association with George W. Hawes, then an
instructor in determinative mineralogy in the
scientific school and engaged in the study of the
rocks of New Hampshire. The Yale atmosphere
with George J. Brush, James Dwight Dana, and
other scholars was also favorable to the devel-
opment of his interest in geology. He passed the
winter of 1878-79, however, in fitting himself
for the duties of a mining engineer, under the
instruction of J. S. Newberry at Columbia, N. Y.
While he was there, a bill was passed by Con-
gress abolishing all existing governmental sur-
veys and creating a new and independent or-
ganization to be known as the United States Geo-
logical Survey, which was placed under the di-
rection of Clarence King. Iddings thereupon
applied for a position, which later received fa-
vorable action and turned him definitely from
the calling of a mining engineer in the direction
which led to his becoming one of America's
foremost petrologists.

While awaiting this decision, acting on the rec-
ommendation of Professors Brush and Hawes,
he went to Europe in 1879 and placed himself
under the tuition of Professor Harry Rosenbusch

Iddings

at Heidelberg, Germany, where he remained un-
til the spring of 1880. After a short tour in
Switzerland he returned to New York, in com-
pany with Arnold Hague [g.z>.], an American
student whose acquaintance he had made at Hei-
delberg, and with whom he was afterward for
a time closely associated. Pending the organi-
zation of King's forces, Iddings and Hague
spent several months in New York arranging
the collection of rocks collected by the Fortieth
Parallel Survey, and studied by Zirkel of Leip-
zig. His first field duties were to assist Hague
in the making of studies of the Eureka district
of Nevada, which were begun in the summer of
1880. The close of the field season found Iddings
again in New York awaiting the development of
a change in administration incidental to the res-
ignation of King and the appointment of J. W.
Powell [g.z>.]. Here he was brought into contact
with G. F. Becker [g.z/.], with whom there arose
a series of differences of opinion on petrographic
subjects, which, without serious detriment to
either, lasted for the rest of their lives.

The summer of 1883 found Iddings a member
of a party under the direction of Arnold Hague,
entering upon a survey of the Yellowstone Na-
tional Park. The work occupied them for seven
subsequent summers, and is the basis upon which
Iddings' scientific reputation largely depends.
In 1895, owing to a failure of appropriations
for a continuance of work on the survey, he
withdrew and accepted the position of profes-
sor of petrology in the University of Chicago
where he remained until 1908. He then resigned
and withdrew to private life, living thereafter
at his country home in Brinklow, Md. Freed
from the confinement of university work, he was
now enabled to undertake somewhat prolonged
geological trips, including one to the islands of
the South Pacific and Indian Ocean where he
made important observations and collected in-
teresting materials which, unfortunately, were
not completely worked up. He quickly estab-
lished himself as a leader in American petrology.
He did not merely describe rock structures but
entered deeply into the theories of igneous mag-
mas and the whole subject of petrogenesis. As
a coworker in the preparation of the epoch-
making Quantitative Classification of Igneous
Rocks (1903) he was one of the most alert. His .
technical papers were carefully and accurately
prepared and never published "subject to revi-
sion." Of those published by the government,
mention can here be made only of his "Micro-
scopical Petrography of the Eruptive Rocks oŁ
the Eureka District, Nevada" (an appendix to

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