Excerpt from Collected Essays and Articles on Physiology and Medicine, Vol. 2 It is now an established doctrine that force, like matter, can be neither created nor destroyed. The different forms of force are mutually convertible the one into the other, but they have their definite reciprocal equivalents, and in the transmutation the exist ing force undergoes no increase or decrease. The force liberated by a certain amount of chemical action will produce a certain amount of heat, and this, in its turn, may be made to accomplish a certain amount of mechanical work. The chemical action has its representative amount of heat, and the heat its representative amount of mechanical work; and the relative value of each is sus ceptible of being expressed in definite terms. It has been ascer tained, for instance, that the force derived from chemical action which will raise the temperature of a pound of water 1 Degrees Fahr. Will, under another mode of manifestation, lift 772 pounds one foot high; 772 foot - pounds are then said to constitute the dynamic equivalent of I of heat of Fahrenheit' S scale. What is true of force in the inorganic world is equally applica ble in the\ organic. The force manifested by living beings has its source by transmutation from other forms which have preexisted. The food of animals contains force in a latent state. Properly regarded, food must be looked upon, not Simply as so much pon derable matter, but as matter holding locked - up force. By the play of changes occurring in the body the force becomes liberated, and is manifested as muscular action, nervous action, assimilative, secretory, Or nutritive action, heat, etc The above is quoted from an article by Dr. F. W. Pavy, published in The Lancet for November 25, 1876. It contains a proposition which, if happily it were true, would mark an advance in positive knowledge of animal mechanics, the importance of which could hardly be over estimated - reducing the ideas of the physiology of mus cular power to a degree of exactness and simplicity most attractive as w'ell as desirable. 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.