Excerpt from Lecture-Notes on Chemistry for Dental Students: Including Dental Chemistry of Alloys, Amalgams, Etc., Such Portions of Organic and Physiological Chemistry as Have Practical Bearing on the Subject of Dentistry Matter has been divided into masses, molecules, atoms and electrons, and we are to study first the properties of these di visions. For purposes of present definitions it may be necessary only to consider that aggregations of electrons constitute atoms; groups of atoms make up the molecules; and numbers of mole cules held together by the physical force of cohesion form masses. The properties of these divisions of matter will constitute our further definition. 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.