it was bound to win our battle for higher ideals in science. The people of the United States owe a great debt of gratitude to Johns Hopkins for the leadership in that great movement which, as we see to-day, has produced a most remarkable intellectual advancement in this country. Nearly thirty years ago I heard Rowland say in a public address: “They always say in Baltimore that no man in that city should die without leaving something to Johns Hopkins.” When he said it he knew that Johns Hopkins was very poor. It is poorer to-day than ever, and no rich man in the United States should die without leaving something to Johns Hopkins, the pioneer university of the United States. Rowland said once that lack of experimental facilities and of time was not a valid excuse for neglecting entirely scientific research. I agreed with that opinion; neglect breeds indifference, and indifference degenerates into atrophy of the spirit of inquiry. The alternating current machine of the electrical engineering laboratory at Columbia was free in the evenings, and so was my time; that is, if my wife should not object, and, being a noble and unselfish woman, she did not object. With the assistance of several enthusiastic students, among them Gano Dunn, to-day one of the most distinguished engineers in the United States, I started investigating the passage of electricity through various gases at low pressures, and published two papers in the _American Journal of Science_. I soon discovered that most of my results had been anticipated by Professor J. J. Thomson, of Cambridge, who, in all probability, had received his inspiration from the same source from which I had received mine. He not only had anticipated me but, moreover, he showed a much better grasp of the subject than I had, and had much better experimental facilities. I decided to leave the field to him, and to watch his beautiful work from the outside. It was a wise decision, because it prepared me to understand the epoch-making discoveries in this field which were soon to be announced, one in Germany and one in France. I turned my attention to another field. I must mention, however, one of the results which Thomson had not anticipated and which created quite an impression among astronomers. I noticed a peculiar appearance in the electrical discharge proceeding from a small metal sphere which was located in the centre of a large glass sphere containing air at low pressure. The discharges looked very much like the luminous corona of the sun which astronomers observe during eclipses, and which was always a mysterious puzzle in solar physics. Pasting a tin-foil disk on the glass sphere, so as to hide the metal sphere and see only the discharge proceeding from it, I photographed the appearance of the discharge and obtained the pictures given opposite page 294. The resemblance of these photographs to those of the two types of the solar corona is most striking. This is what I said about it at that time: