There is a chemic laboratory attached to the Survey, with a large corps of
chemists engaged in a great variety of researches relating to the
constitution of waters, minerals, ores, and rocks. A part of the work of
this corps is to study the methods of metamorphism and the paragenesis of
minerals, and in this connection the chemists do work in the field; but to
a large extent they are occupied with the study of the materials collected
by the field geologists. Professor F.W. Clarke is in charge of this
department.