Excerpt from The Retrospect of Medicine, Vol. 28: Being a Half-Yearly Journal, Containing a Retrospective View of Every Discovery and Practical Improvement in the Medical Sciences, July-December, 1853The specific gravity of a cubic inch of air is '185, that of water is 1000, and that of blood 1050. Forty cubic inches of air weigh about 12980 grains, the same amount of blood weighs about grains. Thus, the latter ¿uid is somewhat 865 times heavier than air, or, as '185 is to 1050. The amount of air, as it passes into the lungs, is op posed by a column of blood coming from the heart, in the proportion of one inspiration to four pulsations of the right ventricle. Each inspira tion carries into the pulmonary cells 40 cubic inches of air, and the average number of inspirations in an adult is 20 per minute. Each ventricular contraction throws two ounces of venous blood into the pull monary cells, and, as there are four contractions to one inspiration, about eight ounces of blood is therefore dispersed through the pulmonary capillaries, from minute to minute.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.