Excerpt from Elements of Physics, or Natural Philosophy, General and Medical: Written for Universal Use Now the four words, atom, attraction, repulsion, inertia, point to four general truths, which explain the greater part of the phenomena of nature. Being so general, they are called physical truths, from the Greek word signifying nature as also truths of Natural Philosophy, with the same meaning, and sometimes mechanical truths, from their close relation to ordinary machinery. These appellations distinguish them from the remain ing general truths, namely the chemical truths, which regard particular substances, and the vital and mental truths, which have relation only to living beings. And even in the cases where a chemical or vital influence operates, it modifies, but does not destroy, the physical influence. By fixing the attention, then, on these four fundamental truths, the student obtains, as it Were, so many keys to unlock, and lights to illuminate the secrets and treasures of nature. 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.