Excerpt from Microscopical Physiography of the Rock-Making Minerals: An Aid to the Microscopical Study of Rocks In abridging the book, I have endeavored to retain all that appeared to be essential to a fair, general comprehension of the sub ject, omitting what seemed to be refinements beyond the need of the average student, and for which the advanced student is referred to the original work. Thus mosfof the historical portions have been omit ted, as well as the elaborate treatment of the optical anomalies of cer tain minerals, and many notes on European localities; While a number of notes on American occurrences have been inserted. 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.