Excerpt from Protein Split Products in Relation to Immunity and Disease Many years ago the senior contributor to this volume began a research on the chemistry of bacterial cellular substance. This work'has grown and the progress made has been reported from time to time in current scientific and medical literature. Able assistants have rendered valuable service, and as the research has developed it has been correlated with that done'along similar lines in other laboratories. We feel that the time has come when the more important facts ascertained along this and related lines, by all investigators, should be classified and proper deductions drawn from them. We are the more inclined to do this because we believe that the proper interpretation of the results Obtained opens up a view of the etiology and development of both immunity and disease, which has hitherto not been appreciated. We have thought it best to state briefly in this introduction some of the most impor tant points dwelt upon in the volume. We have done this somewhat dogmatically, hoping that they will impress the reader and hold his attention while they are more fully detailed in subsequent chapters. 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.