Chemical relations of rocks and their graphic representation

Abstract

“Whoever sought to give himself a clear account of the chemical relations of rocks had to see with amazing clarity all the imperfections of our information on this issue. We have to admit that real, exact science has hardly yet touched upon this important issue, and the most primitive empiricism reigns here. A large number of types of rocks are exhibited, receiving numerous names, but there is not even a generally accepted criterion for distinguishing one type, or, more precisely, a type of rock from another."