Excerpt from The American Journal of Roentgenology, 1922, Vol. 9 This paper was undertaken in the hope that some improvement in this situation might result through the application of old principles rather than th1ough the contribution of anything essentially new, and through the adoption of a simpler but more comprehensive routine technique. 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.