Hill

tion of the moon. This is, in effect, a particular
case of the problem of four bodies.

While Hill was essentially a mathematician,
he was interested in the subject only in so far as
it could be used to deduce astronomical and
other phenomena, and particularly those which
depend on the law of gravitation. He had little
interest in the modern developments of mathe-
matics. His work bears in many respects a
striking similarity to that of his contemporary,
J. C Adams, of Cambridge, England, the co-
discoverer with Leverrier of the planet Neptune.
In fact, immediately after the appearance of
Hill's paper on the lunar perigee, Adams pub-
lished one which showed that he had worked on
the same lines and even had constructed and
evaluated the infinite determinant. Adams, how-
ever, had kept to the lunar problem, while Hill,
as mentioned above, extended the idea in a gen-
eral manner. The marks of recognition of his
work included the presidency of the American
Mathematical Society and the award in 1909 of
the Copley Medal of the Royal Society of Lon-
don—the highest scientific honor in the British
Empire. He was a lecturer at Columbia Uni-
versity, 1898-1901, but characteristically re-
turned the salary, writing that he did not need
the money and that it bothered him to look after
it. His needs like his income were small. He
was not gifted as an expositor. His papers while
clearly expressed are very concise. On one oc-
casion the method of deducing a long algebraical
development which required special devices and
several weeks of concentrated work is dismissed
in a line. Most of his published papers have
been reprinted by the Carnegie Institution of
Washington in four quarto volumes, with a pref-
ace by Henri Poincare, The Collected Mathe-
matical Works of George William Hill (1905-

07).

[Nat. Acad. of Sciences, Biog. Memoirs, vol. VIII
(1919) ; Proc. of the Royal Soc. of London, ser. A,
vol. XCI (1915) ; Columbia Univ. Quart., Sept. 1914;
Nation (N. Y.), May 7, 1914.] E. W. B.

HILL, HENRY BARKER (Apr. 27, 1849-
Apr. 6, 1903), educator, chemist, second of the
six children of Thomas Hill [g.z/.] and Ann
Foster (Bellows) Hill, was born at Waltham,
Mass. His boyhood was passed at Waltham,
Yellow Springs, Ohio, and Cambridge, Mass,
Graduating from Harvard College in 1869, the
year after his father's resignation of the presi-
dency, he spent a year at the University of Ber-
lin and then, upon the urgent advice of his father,
accepted the position of second assistant in chem-
istry at Harvard. His career as a teacher cen-
tered chiefly in qualitative analysis and organic
chemistry. The former he raised from the pure-

Hill

ly mechanical to a discipline of the highest peda-
gogical value, admirably adapted to give a stu-
dent a foundation for a career in research. His
lectures in organic chemistry showed his origi-
nality of thought and independence of conven-
tion. He had an uncanny instinct for separating
the essential from the nonessential. Further-
more, he kept always up to date, no easy matter
in a rapidly growing science; he frequently
reached conclusions on debatable topics ahead of
the prevailing opinion of other experts in the
field. This was notably true in the case of the
constitution of the diazo compounds. Years later
the views on this intricate and highly valuable
group which he set before his students were
adopted by chemists, and they are still held. In
1874 he published Lecture Notes on Qualitative
Analysis.

In the year following his return from Ger-
many, Hill had married (Sept. 2, 1871) Ellen
Grace Shepard, daughter of Otis and Ann
(Pope) Shepard of Dorchester, Mass., and sister
of his father's second wife. To meet his neces-
sary expenditures, modest as they were, he was
obliged to supplement the meager stipend which
he received from the College by devoting his
spare time to commercial chemistry. He made
investigations on food adulterations for the State
Board of Health, rendered valuable service in
solving chemical problems for a bleachery, and
for some years was consulting chemist for the
Carter ink company. After months of prepara-
tory experimentation, he issued, in 1876, a study
of the methyl derivatives of uric acid (Proceed-
ings of the American Academy of Arts and Sci-
ences, vol. XII, 1877). His method in this in*
vestigation, in the hands of the celebrated
German chemist, Emil Fischer, later led to the
final explanation of the constitution of uric acid.
Induced by Edward Robinson Squibb [q.vJ] to
undertake the investigation of a previously use-
less by-product of the manufacture of acetic acid
from the distillations of oak wood, Hill found
therein abundance of furaldehyde, commonly
called furfurol. Abandoning further work on the
constitution of uric acid, he started an intensive
investigation of the furaldehyde derivatives which
occupied the rest of his scientific career and
resulted in thirty publications. Most of his pa-
pers were contributed to the Proceedings of the
American Academy of Arts and Sciences or to
the American Chemical Journal.

His scientific work was conspicuous for his
genius in getting at the kernel of a problem, ex-
ceptional experimental technique, and painstak-
ing thoroughness. This same thoroughness he
demanded from all his students. His criticisms

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