Excerpt from A Treatise on Human Physiology: Designed for the Use of Students and Practitioners of Medicine Since the last edition of this work, nearly all the department of medicine have been cultivated with marked success; and the advances in physiological science during that time have made it desirable to revise the greater part of the book, and in, some respects, to modify its arrangement. In the section of Physiological Chemistry, the most important alterations relate to the classification of the Albumenoid Substances, and particularly to the prominence given to the Ferments as a special group. Although we are still very imperfectly acquainted with the chemical constitution of these bodies, and are even able to recognize them rather by the effects which they produce than by their physical properties, yet their physiological activity has assumed an importance which makes it necessary to consider them by themselves. In treatises exclusively devoted to Physiological Chemistry, the albumenoid substances are usually classified according to their characters of solubility in neutral, acid, or alkaline media, or in saline solutions of different degrees of concentration, or by the varying conditions of their coagulability; but in a work like the present, an arrangement based on their physiological properties and destination is both more useful and more intelligible. The same remark will apply, in great measure, to the other principal groups of organic substances. In the department of the Nervous System, more extended consideration has been given to the localization of function in special parts of the cerebro-spinal axis. The recent progress of investigation in this respect relates not only to the cerebral convolutions and their connection with various forms of movement and sensation, but also to the identification of special communicating tracts of white substance in the brain and spinal cord. 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.