It was in the School of Physics， in the old buildings of the Collège Rollin， that Pierre Curie was destined to work， first as Director of Laboratory Work， then as Professor， for twenty-two years， a period covering practically the whole of his scientific life. His memory seemed to cling to these old buildings， now destroyed， in which he had passed all his days， returning only in the evening to his parents in the country. He counted himself fortunate since he enjoyed the favor of the Founder-Director Schützenberger， and the esteem and good will of his students， many of whom became his disciples and friends. In alluding to this experience， at the close of an address delivered at the Sorbonne near the end of his life， he said：
"I desire to recall here that we have made all our investigations in the School of Physics and Chemistry of the city of Paris. In all creative scientific work the influence of the surroundings in which one works is of great importance， and a part of the result is due to that influence. For more than twenty years I have worked in the School of Physics and Chemistry. Schützenberger， the first director of the School， was an eminent scientist. I remember with gratitude that he procured for me opportunities for my own investigations when I was yet but an assistant. Later， he permitted Madame Curie to work beside me， an authorization which was at that time far from an ordinary innovation. Schützenberger allowed us all great liberty； his direction made itself felt chiefly through his inspiring love of science. The professors of the School of Physics and Chemistry， and the students who have gone from it， have created a kindly and stimulating atmosphere that has been extremely helpful to me. It is among the old students of the school that we have found our collaborators and our friends. I am happy to be able， here， to thank them all."
The newly appointed director of the laboratory was， when he first assumed his duties， scarcely older than his students， who loved him because of his extreme simplicity of manner， which was much more that of a comrade than of a master. Some of these students recall with emotion their work carried on with him and his discussion at the blackboard， where he readily allowed himself to be led to debate scientific matters to their great profit both in information and in kindled enthusiasm. At a dinner given in by the Association of Former Students of the School， which he attended， he laughingly recalled an incident of this period. One day after lingering late with several students in the laboratory， he found the door locked， and they all had to climb down from the first floor single file， along a pipe that ran near one of the windows.
Because of his reserve and shyness he did not make acquaintances easily， but those whose work brought them near him loved him because of his kindliness. This was true of his subordinates during his entire life. In the school his laboratory helper， whom he had aided under trying circumstances， thought of him with the greatest gratitude， in fact， with veritable adoration.
Although separated from his brother， he remained bound to him by their former bond of love and confidence. During vacations， Jacques Curie would come to him that they might renew again that valuable collaboration to which both willingly sacrificed their periods of liberty. At times it was Pierre who joined Jacques， who was engaged in making a geological chart of the Auvergne country， and there they covered together the daily distances necessary to the tracing of such a map.
Here are a few memories of these long walks， extracts from a letter written to me shortly before our marriage：
"I have been very happy to pass a little time with my brother. We have been far from all immediate care， and so isolated by our manner of living that we have not even been able to receive a letter， never knowing one night where we would sleep the next. At times it seemed to me that we had gone back to the days when we lived entirely together. Then we always arrived at the same opinions about all things， with the result that it was no longer necessary for us to speak in order to understand each other. This was all the more astonishing because we differed so entirely in character."
From the point of view of scientific investigation， one must recognize that the nomination of Pierre Curie to the School of Physics and Chemistry retarded from the very first his experimental research. Indeed， at the time of his appointment nothing yet， existed in that establishment； everything had to be created. Even the walls and the partitions were hardly yet in place. He had， therefore， to organize completely the laboratory and its work， and he acquitted himself of this task in a remarkable manner， injecting into it the spirit of precision and originality so characteristic of him.
The direction of the laboratory work of the large number of students (thirty by promotion) was alone a strain on a young man， assisted as he was only by one laboratory helper. The first years were， therefore， hard years of assiduous work， of benefit chiefly to the students trained and developed by the young laboratory director.
He himself profited by this enforced interruption of his experimental research by trying to complete his scientific studies and， in particular， his knowledge of mathematics. At the same time he became engrossed in considerations of a theoretical nature on the relations between crystallography and physics.
