The Founders of Geology (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated.1905 Excerpt: ... CHAPTER V The Foundation of Volcanic Geology. Desmarest. The leading position acquired by France in the investigation of the history of the earth, through the labours of such men as Descartes, Buffon and Guettard, was well maintained in the later decades of the eighteenth century. Geology indeed as a distinct science did not yet exist. The study of rocks and their contents was known as mineralogy, which as a pursuit, often of economic value, had been in vogue for centuries. The idea that beyond the mere variety of its mineral contents, the crust of the earth contained a record of the earth's evolution, for many ages before the advent of man, only very slowly took definite shape. Buffon partly realized it; Guettard had a fuller perception of its nature, though he failed to observe proofs of a long succession of changes earlier than the present condition of the surface. One of the most valuable parts of Guettard's work was his recognition of the existence of volcanic rocks in regions far removed from any active volcano. We have seen that he was led to this important deduction by a train of observation and inference, and that although he never worked out the subject in detail, Nicholas Desmarest the credit of the first discovery, denied to him in his lifetime and after it, must in common fairness be assigned to him. Central France was the region that furnished Guettard with his proofs of extinct volcanoes. It was the same region that afterwards supplied fuel to the controversy over the origin of basalt which raged with fury for so many years, and it was from this region also that the proofs were obtained which more than any others brought that controversy to an end. The story of this old battle is full of interest and instruction. We learn from it how the adva...