Beschrijving

The problems of the classification of rocks, particularly igneous rocks, and of the nature and genesis of ores are obviously chemical and, by the mid- 19th century, chemistry was in a state where rocks could be effectively analyzed, and a classification built up depending partly on chemistry and partly on the optical study of thin specimens.

The founders of geology at the beginning of the last century were suspicious oflaboratories. Hutton’s well-known dictum illustrates the point: \