RECOLLECTIONS AND REFLECTIONS
money out of them, for he says that the fate of a successful inventor is to be exposed to " envy, robbery and abuse ".
Philadelphia owes to Franklin some of its most important institutions. Soon after his first arrival there, when a boy of seventeen, he started a kind of Mutual Improvement Society with a few friends. This developed into the American Philosophical Society, the oldest scientific society in America, and also into the Union Library of Philadelphia, one of the oldest and most interesting libraries in the country. The University of Philadelphia grew out of a College he had started, and the largest hospital in Philadelphia owes its inception to him.
I gave five lectures at the Franklin Institute on " The Electron in Chemistry " : these were subsequently published under this title for the Franklin Institute, by the J. B. Lippincott Company. I give in the preface of this book my reasons for choosing this subject : "It has been customary to divide the study of the properties of matter into two sciences, physics and chemistry. In the past the distinction was a real one, owing to our ignorance of the structure of the atom and the molecule. The region inside the atom or molecule was an unknown territory in the older physics, "which had no explanation to offer as to why the properties of an atom of one element differed from those of another. As Chemistry is concerned mainly with these differences there was a very real division between the two sciences. In the course of the last quarter of a century, however, the physicists have penetrated into this territory and have arrived at a conception of the atom which indicates the ways in which an atom of one element may differ from that of another." The electron is the dominating factor in this question, so that it is important 258