The Journal Of Geology 1900 Vol 8 PDF Download

Excerpt from The Journal of Geology, 1900, Vol. 8: A Semi-Quarterly Magazine of Geology and Related Sciences The introduction of the petrographical microscope and its accessories, bringing as it did quick and delicate methods for determining the mineral constitution of a rock, naturally enough drew away the attention of petrographers from the slower and less brilliant methods of chemical analysis, which up to that time had been almost the only ones in use. Moreover most of the analyses of the period were, as we now know, inaccurate and failed to show the real chemical differences between individual rocks. The multiplication of the number of analyses and the improvements in the methods of rock analysis which have been made during the last decade, particularly by Hillebrand, have disclosed important differences among rocks formerly classed together, and thus necessitated a considerable elaboration of the systems of classification. With this elaboration rock names have been introduced into the science with a rapidity which is little Short of bewildering. The older petrological nomenclature was largely binomial or polynomial (i. E., mica-syenite, quartz-mica-diorite) though the recent names seem planned for a monomial nomenclature (i. E., ciminite). It is therefore not strange that misunderstanding has arisen in some quarters, where it is not realized that the new names proposed are for the most part specific and varietal in their nature and in no way to be correlated with the great family names such as granite or gabbro, and hence a protest has been made against what seems a needless overburdening of the science with names. Without entering upon this question here it may, I think, be stated with all assurance that some reforms are imperatively demanded before the worker will be fully equipped to discover the relationships among rocks because of the incubus of unclassified facts by which the science is now encumbered. Some of the particular reforms which to me seem desirable and practicable will be briefly described. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.