Pierre received his licentiate in physical sciences at the age of eighteen. During his studies he had attracted the attention of Desains, director of the University laboratory, and of Mouton, assistant director of the same laboratory. Thanks to their appreciation he was appointed, when only nineteen years old, preparator for Desains and placed in charge of the students' laboratory work in physics. He held this position five years, and it was during this time that he began his experimental research.
It is to be regretted that because of his financial situation Pierre was obliged, at this early age of nineteen, to accept the post of preparator instead of being able to give his whole time for two or three years longer to his University studies. With his time thus absorbed by his professional duties and his investigations he had to give up following the lectures in higher mathematics, and he therefore passed no further examinations. In compensation, however, he was released from military service in conformity with the privileges at that time accorded young men who undertook to serve as teachers in the public-school system.
He was by this time a tall and slender young man with chestnut-colored hair and a shy and reserved expression. At the same time his youthful face mirrored a profound inner life. One has such an impression of him as he appears in a good group photograph of Doctor Curie's family. His head is resting on his hand in a pose of abstraction and reverie, and one cannot but be struck by the expression of the large, limpid eyes that seem to be following some inner vision. Beside him the brown-haired brother offers a striking contrast, his vivacious eyes and whole appearance suggesting decision.
The two brothers loved each other tenderly and lived as good comrades, being accustomed to work together in the laboratory and walk together in their free hours. They also kept up affectionate relations with a few of their childhood friends: Louis Depouilly, their cousin, who became a physician; Louis Vauthier, also later a physician; and Albert Bazille, who became an engineer in the post and telegraph service.
Pierre used to tell me of the vivid memories he had of the vacations passed at Draveil on the Seine, where, with his brother Jacques, he took long walks beside the river, agreeably interrupted by swimming and diving in the stream. Both brothers were excellent swimmers. Sometimes they tramped for entire days. They had, at an early age, acquired the habit of visiting the suburbs of Paris on foot. At times also Pierre made solitary excursions which well suited his meditative spirit. On these occasions he lost all sense of time, and went to the extreme limit of his physical forces. Absorbed in delightful contemplation of the things about him, he was not conscious of material difficulties.
On the pages of a diary written in , he thus expressed the salutary influence of the country upon him:"Oh, what a good time I have passed there in that gracious solitude, so far from the thousand little worrying things that torment me in Paris. No, I do not regret my nights passed in the woods, and my solitary days. If I had the time I would let myself recount all my musings. I would also describe my delicious valley, filled with the perfume of aromatic plants, the beautiful mass of foliage, so fresh and so humid, that hung over the Bièvre, the fairy palace with its colonnades of hops, the stony hills, red with heather, where it was so good to be. Oh, I shall remember always with gratitude the forest of the Minière; of all the woods I have seen, it is this one that I have loved most and where I have been happiest. Often in the evening I would start out and ascend again this valley, and I would return with twenty ideas in my head."
Thus, for Pierre Curie, the sensation of well-being he experienced in the country was derived from the opportunity for tranquil reflection. Daily life in Paris with its numerous interruptions did not permit of undisturbed concentration, and this was to him a cause of inquietude and suffering. He felt himself destined for scientific research; for him the necessity was imperative of comprehending the phenomena of Nature in order to form a satisfactory theory to explain them. But when trying to fix his mind on some problem he had frequently to turn aside because of the multiplicity of futile things that disturbed his reflections and plunged him into discouragement.
Under the heading, "A day like too many others," he enumerated in his diary a list of the puerile happenings that had completely filled one of his days, leaving no time for useful work. He then concluded: "There is my day, and I have accomplished nothing. Why?" Further on he returns to the same theme under a title borrowed from Victor Hugo's "Le Roi S'Amuse" :
"To deafen with little bells the spirit that would think."
"In order that, weak one that I am, I shall not let my head turn with all the winds, yielding to the least breath that touches it, it is necessary that all should be immobile about me, or that, like a spinning top, movement alone should render me insensible to external objects. "
