So we remained in Paris, and with our income increased. But we were at the same time working under increasingly difficult conditions. Pierre Curie was doing double teaching; and that in the P.C.N., with its very large number of students, fatigued him greatly. As for myself, I had to give much time to the preparation of my lectures at Sèvres, and to the organization of the laboratory work there, which I found very insufficient. Moreover, Pierre Curie's new position did not bring with it a laboratory; a little office and a single work room were all that he had at his disposition in the annex (12 rue Cuvier) of the Sorbonne, which served as teaching quarters for the P.C.N. And yet he felt it absolutely necessary to go ahead with his own work. In fact, the rapid extension of his investigations in radioactivity had made him determine that in his new position at the Sorbonne he would receive students and start them in research. He therefore took steps to find larger available working quarters. Those who have taken similar steps realize the wall of financial and administrative obstacles against which he was throwing himself, and realize the large number of official letters, visits, and of requests the least success entailed. All this thoroughly wearied and discouraged Pierre Curie. He was obliged, too, constantly, to keep traveling back and forth between the laboratories of the P.C.N. and the hangar of the School of Physics where we still continued our work. And besides these difficulties, we found that we could not make further progress without the aid of industrial means of treating our raw material. Fortunately certain expedients and generous assistance solved this question. As early as 1899 Pierre Curie succeeded in organizing a first industrial experiment, using for it a chance installation placed at his disposition by the Central Society of Chemical Products, with which he had had relations in connection with the construction of his balances. The technical details had been arranged very successfully by André Debierne, and the operations brought good results, even though it had been necessary to train a special personnel for this chemical work which demanded special precautions.