Pierre passed his childhood entirely within the family circle; he never went to the elementary school nor to the lycée. His earliest instruction was given him first by his mother and was then continued by his father and his elder brother, who himself had never followed in any complete way the course of the lycée. Pierre's intellectual capacities were not those which would permit the rapid assimilation of a prescribed course of studies. His dreamer's spirit would not submit itself to the ordering of the intellectual effort imposed by the school. The difficulty he experienced in following such a program was usually attributed to a certain slowness of mind. He himself believed that he had this slow mind and often said so. I think, however, that this belief was not entirely justified. It seems to me, rather, that already from his early youth it was necessary for him to concentrate his thought with great intensity upon a certain definite object, in order to obtain a precise result, and that it was impossible for him to interrupt or to modify the course of his reflections to suit exterior circumstances. It is clear that a mind of this kind can hold within itself great future possibilities. But it is no less clear that no system of education has been especially provided by the public school for persons of this intellectual category, which nevertheless includes more representatives than one would believe at first sight.

Very fortunately for Pierre, who could not, as we can see, become a brilliant pupil in a lycée, his parents had a sufficiently keen intelligence to understand his difficulty, and they refrained from demanding of their son an effort which would have been prejudicial to his development. If, then, Pierre's earliest instruction was irregular and incomplete, it had the advantage of not so weighing on his intelligence as to deform it by dogmas, prejudices or preconceived ideas. And he was always grateful to his parents for this very liberal attitude. He grew up in all freedom, developing his taste for natural science through his excursions into the country, where he collected plants and animals for his father. These excursions, which he made either alone or with one of the family, helped to awake in him a great love of Nature, a passion which endured to the end of his life.

Intimate contact with Nature, which, because of the artificial conditions of city life and of traditional education, few children can know, had a decisive influence on Pierre's development. Guided by his father, he learned to observe facts and to interpret them correctly. He became familiar with the animals and plants of the environs of Paris. He knew which ones could be found at each season of the year in the forests and fields, the streams and ponds. The ponds in particular had for him an ever new attraction with their characteristic vegetation and their population of frogs, tritons, salamanders, dragonflies, and other denizens of air and water. No efforts to obtain the objects of his interests seemed too great for him. He never hesitated to take any animal in his hands in order to examine it more closely. Later, after our marriage, in our walks together, if I made some objection to letting him put a frog into my hands, he would exclaim: "But no, see how pretty it is!" He loved always, too, to bring back bouquets of wild flowers from his walks.

Thus his knowledge of natural history progressed rapidly. At the same time, also, he was mastering the elements of mathematics. His classical studies, on the contrary, had been much neglected, and it was principally through general reading that he acquired a knowledge of literature and history. His father, who was widely cultured, possessed a library containing many French and foreign works. Having himself a very pronounced taste for reading, he was able to communicate it to his son.

When he was about fourteen years old, a very happy event occurred in Pierre's education. He was put under an excellent professor, A. Bazille, who taught him elementary and advanced mathematics. This master was able to appreciate his young pupil, became much attached to him, and directed his work with the greatest solicitude. He even helped him to advance in his study of Latin, in which he was very much behind. At the same time Pierre and Albert Bazille, his professor's son, became friends.

This teaching had, I am sure, a great influence on the mind of Pierre, aiding him to develop and to sound the depth of his faculties and to realize his capacities for science. He had a remarkable aptitude for mathematics, which expressed itself chiefly by a characteristic geometric spirit and a great power of spatial vision. He, therefore, progressed rapidly and joyfully in his studies under M. Bazille, for whom he always felt an unalterable gratitude.

He once told me something which proved that even at this time he was not content solely to follow a fixed program of studies, but that he had already begun to launch out into personal investigation. Strongly attracted by the theory of determinants, which he had just mastered, he undertook to realize an analogous conception, but in three dimensions, and endeavored to discover the properties and uses of these "cubical determinants." Needless to say that at his age, and with the knowledge then at his disposal, such an enterprise was beyond his powers. The attempt, however, was none the less indicative of his awakening inventive spirit.

Several years later, when preoccupied with reflections upon symmetry, he asked himself the question: "Could not one find a general method for the solution of any equation whatever? Everything is a question of symmetry." He did not then know of Galois' theory of groups which had made it possible to attack this problem. But he was happy later to learn its results in the geometric applications to the case of equations of the 5th degree.

Thanks to his rapid progress in mathematics and physics, Pierre Curie was made a bachelor of science at the age of sixteen years. With this he passed his most difficult stage of formal education. The only thing with which he had to concern himself in the future was the acquisition of knowledge through his personal and independent effort in a field of science freely chosen.

CHAPTER II
DREAMS OF YOUTH. FIRST SCIENTIFIC WORK. DISCOVERY OF PIEZO-ELECTRICITY