Excerpt from Elements of Crystallography: For Students of Chemistry Physics and Mineralogy To both chemists and physicists the subject is important, although the information in regard to it embraced in text-books and lectures on chemistry and physics is usually inadequate. Crystals are constantly employed as a means of purifying, recognizing and tracing the relationships between chemical compounds of all sorts; their genesis and growth offer interesting problems in molecular physics, and their completed forms furnish material for the study of elasticity, co hesion and the propagation Of various forms of radiant energy. To the geologist in every field, as well as to the mining engineer, Crystallography is the starting-point to a knowledge of mineralogy, while to the student of petrography an acquaintance with crystal form and its relation to the Optical properties of crystals is indis pensable. 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.