Excerpt from The Analytical Expression of the Results of the Theory of Space-Groups It was the original intention simply to state these results and to outline the method whereby they were obtained. The writer is firmly convinced, however, that sure and definite progress in this relatively new field of crystal structure can be realized only by making the fullest possible use of the added information which the theory of space-groups furnishes; and since any dis cussion of this theory is almost completely absent from work published in English, it has seemed worth while to add a brief introduction in order to give such details of the space groups and of their development as seem to furnish suficient background for the appreciation of the importance of the theory in this new field of physical science. 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.