CHEMICAL AND PHYSICAL RESEARCHES. 53 
could be commercially extracted and freed from its impurities. The 
results obtained will be found in Bulletin No. 60. 
For Survey publications on chemical subjects, see the Survey's list 
of publications. A very large part of the work done for the geolo- 
gists, however, is scattered through the various publications of the 
Survey; and in addition to the official publications the chemists have 
been frequent contributors to scientific journals, to the Smithsonian 
Miscellaneous Collections, and to the proceedings of chemical and 
other societies, both in this country and in Europe. 
Section of Physics. 
Physical research by the- United States Geological Survey began in 
1880, under direction of the geologist in charge of the division of 
California, when it appeared desirable to investigate the extraordinary 
thermal conditions of the Comstock Lode and to ascertain whether 
terrestrial electricity and magnetism were disturbed by the presence 
of ore bodies. The results are contained in Monograph III, on the 
Comstock Lode, and in the Annual Report for the year 1882. 
At the close of this investigation, which was of course made in the 
field with portable and more or less extemporized apparatus, plans 
were prepared, under the direction of the late Mr. Clarence King, 
then Director of the Survey, for the equipment of a laboratory and 
the systematic study of certain geophysical problems under more 
favorable conditions. Most of the apparatus for this laboratory was 
constructed in Europe, the expense being borne personally by the 
Director, Mr. King. By November, 1882, the apparatus was received, 
and a private house in New Haven, Conn., was rented for use as a 
laboratory. 
A brief classification of the researches proposed at that time is con- 
tained in the Second Annual Report of the Survey, and is of very 
considerable interest. If such a classification of the most important 
work to be done in geophysics were required to-day, after twenty 
years of marvelously active and productive work in most other 
branches of science, the classification then made would serve without 
the change of a word, so little attention has been given to geophysical 
problems as compared with those of other sciences. 
The outline was this: 
(a) Phenomena of fusion. These would comprehend temperature of fusion, 
specific volume at this temperature of the solid and of the liquid materials, respec- 
tively, heat expansion, compressibility, latent heat of fusion, specific heats— all 
considered with especial reference to their variation with pressure. 
(6) Phenomena of elasticity and viscosity, considered, as before, with especial 
reference to their dependence on temperature and pressure. 
(c) Phenomena of heat conductivity under analogous circumstances. 
The establishment at New Haven was planned on a large scale and 
was intended to be permanent, but relatively little more than the 
