NOVEMBER 71, 1899. ] 
department of Yale under the elder Silli- 
man. Seldom has an opportunity been used 
to greater advantage, and so quickly did he 
acquire a knowledge of the sciences pre- 
sented, that after two years in New Haven 
he was, in 1847, appointed chemist and 
mineralogist to the Geological Survey of 
Canada, a place which he then held for ex- 
actly a quarter of a century. During that 
period, with his unusual powers, he pre- 
sented to the scientific world those remark- 
able contributions to the. twin studies of 
chemistry and geology that have gained for 
him a foremost place among the pioneers of 
the newer science of geological chemistry. 
His early papers treated of chemistry. He 
developed a system of organic chemistry in 
which all chemical compounds were shown 
to be formed on simple types represented 
by one or more molecules of water or hy- 
drogen.* He anticipated Dumas with his 
researches on the equivalent volumes of 
liquids, and in 1887 published in book 
form, under the title A New Basis for 
Chemistry, a full digest of his papers, form- 
ing a complete system of his theory of chem- 
istry. 
In 1872 he returned to the United States 
and accepted the chair of geology in the 
Massachusetts Institute of Technology made 
vacant by the retirement of William B. 
Rogers, and remained in that capacity 
until 1878, after which New York City be- 
came his principal home, and he devoted 
his leisure, until his death, in perfecting 
his books, which present in matured form 
the opinions originally published as ad- 
dresses or special papers. They include 
Chemical and Geological Essays ; Mineral 
Physiology and Physiography ; and Sys- 
tematic Mineralogy According toa Natural 
System, and according to R. W. Raymond, 
‘constitute a monument to his genius, 
industry, and learning which certainly 
*See a Century’s Progress in Chemical Theory. 
American Chemist, Vol. V., p. 56, August, 1874. 
SCIENCE. 
709 
cannot be overlooked by the historian of 
science. ’”* 
Three times during the life of our Asso- 
ciation has the science of botany been con- 
spicuously honored by the selection of its 
most distinguished representative to pre- 
side over one of our meetings. The first 
of these occasions was in 1855 when the 
able Torrey filled the presidential chair 
with much grace and dignity, and the sec- 
ond was at the Indianapolis meeting in 
1871, when Asa Gray was the presiding 
officer. 
GRAY. 
Gray} was born in the Sauquoit Valley, 
in New York, in 1810, and was the son of 
a farmer. At an early age he showed a 
greater fondness for reading than for duties 
- around the farm, and his father wisely de- 
cided to make a scholar of him. He was 
sent to school in Clinton, New York, and 
later to an academy in Fairfield, New York. 
At the last-named place in compliance 
with the desires of his father he entered 
the medical school, and in 1831 received 
his doctor’s degree from that institution. 
Meanwhile, however, he acquired an inter- 
est in natural science, largely through the 
influence of Dr. James Hadley, the pro- 
fessor of materia medica and chemistry. 
Farlow says ‘he was not at first so much 
interested in plants as in minerals,’} and 
this is of special interest, for it was about 
that time that he first met Dana, with 
whom he ever afterward maintained a 
close friendship. 
* Engineering and Mining Journal, February 20, 
1892. 
{See Memorial of Asa Gray reprinted from the 
Proceedings of the American Academy of Arts and 
Sciences, and Biographical Memoirs of the National 
Academy of Sciences, Vol. III., p. 161, Asa Gray, by 
W. G. Farlow. See also Letters of Asa Gray, by 
Mrs. Jane Loring Gray, 2 vols. Boston, 1893 ; and 
Scientific papers of Asa Gray, selected by Charles S. 
Sargent. 2 vols. Boston, 1888. 
{ Memorial of Asa Gray, p. 20. 
