The remarkable results of these historic experiments forced, one may say, upon the physicist the electromagnetic theory of matter, the theory, namely, that the ultimate components in the structure of matter are positive and negative electrons. This theory was vaguely foreshadowed by Faraday in his poetic visions suggested by his researches on electrolysis. Needless to say, the physicists in the United States were thrilled by these revelations, and by the new views disclosed by them, perhaps even more than by the discoveries of the X-rays and of radioactivity. The first visible effect of this thrill was the organization in 1899 of the American Physical Society, a quarter of a century after Tyndall’s visit to this country. Just think of it, the great United States had no physical society prior to that time! It is an interesting fact that two of the most important American organizations in abstract science were started at Columbia College. The first was the American Mathematical Society. In 1888, two young instructors at Columbia College, Fiske and Jacoby, started a mathematical club. To-day the first is a professor of mathematics, and the second is a professor of astronomy at Columbia University. I joined them in 1889, as soon as I had returned to Columbia. We transformed the mathematical club into the New York Mathematical Society, and elected for president the famous Columbia don, the late Howard Van Amringe, for many years senior professor of mathematics at Columbia College. Doctor Fiske was its secretary; no young and struggling scientific organization ever had a better secretary. The society prospered, and in 1894 it was transformed into the American Mathematical Society, counting among its members most of the distinguished mathematicians of the land. I am certainly very proud that I am one of its charter members.