Excerpt from The Useful Arts, Considered in Connexion With the Applications of Science, Vol. 2 of 2: With Numerous Engravings The swimming bladder, which exists in most fishes, though not in all, is supposed to have an agency in adapting the specific gravity of the fish to the particular depth, in which it resides. The power of the animal to rise or sink, by altering the dimensions of this organ, has been, with some reason, disputed. T Lectures on Comparative Anatomy, vol. I. P. 116, Sir E Home deduces this fact from the anatomy of the animal, and from the movements which he perceived, in suffering a large coluber to crawl over his hand. The ribs appeared to be raised, spread, carried for ward, depressed, and pushed backward, successively. 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.