Among the latter, E. Gouy, professor of the faculty of sciences at Lyon, should be named. His friendly relations with Pierre Curie dated from the time when they were both preparators at the Sorbonne. They carried on regularly a scientific correspondence, and took great pleasure in seeing each other again during the various brief visits of E. Gouy to Paris, on which occasions they were inseparable. There existed also a friendship of long standing between my husband and Ch. Ed. Guillaume, now director of the International Bureau of Weights and Measures of Sèvres. They met at the Physics Society and occasionally on Sundays at Sèvres or Sceaux. Later a group of younger men formed themselves about Pierre Curie. They were investigators engaged, as he was, in physical and chemical research in the newest fields of these sciences. Among these men were André Debierne, my husband's intimate friend and collaborator in the work on radioactivity; George Sagnac, his collaborator in a study of the X-rays; Paul Langevin, who became a professor in the Collège de France; Jean Perrin, at present professor of physical chemistry in the Sorbonne; and Georges Urbain, student of the School of Physics and later professor in the Sorbonne. Often one or the other came to see us in our quiet house in the Boulevard Kellermann. Then we engaged in discussions of recent or future experiments, or of new ideas and theories, and never tired of rejoicing over the marvelous development of modern physics. There were not many large reunions in our house, for my husband did not feel the need of them. He was more at his ease in a conversation with some one or few persons, and rarely attended any meetings except those of the scientific societies. If by chance he found himself in a gathering where the general conversation did not interest him, he took refuge in a tranquil corner where he could forget the company as he pursued his own thoughts. Our relations with our families were very restricted on his side as on mine; for he had few relatives and mine were far away. He was, however, very devoted to those of my family who could come to visit me in Paris, or during our vacations. In 1899, Pierre Curie made a journey with me to the Carpathians of Austrian Poland, where one of my sisters, married to Doctor Dluski and herself a physician, directed, with him, a large sanatorium. Through a touching desire to know all that was dear to me, my husband, though he knew little of foreign languages, wished to learn Polish, something which I had not thought of suggesting because I did not believe it could prove sufficiently useful to him. He felt a sincere sympathy for my country and believed in the future Establishment of a free Poland.