Louis Pasteur: His Life and Labours

by René Vallery-Radot

It was not until he reached the third class that Louis Pasteur, beginning to realise the sacrifices which his father imposed upon himself, determined to abandon his fishing implements and his crayons, feeling aroused within him that passion for work which was to form the foundation of his life. The Principal of the college, who followed with watchful interest the progress of a pupil who, in his first effort, had outstripped all his comrades, used to say, 'He will go far. It is not for the chair of a small college like ours that we must prepare him; he must become professor in a royal college. My little friend,' he would add, 'think of the great École Normale.'

The College of Arbois having no professor of philosophy, Pasteur quitted it for Besançon. There he remained for the scholars' year, received the degree of bachelier ès lettres, and was immediately appointed tutor in the same college. In the intervals of his duties he followed the course of mathematics necessary to prepare him for the scientific examinations of the École Normale. He must have been already endowed with a singular maturity of character, for the director confided to him the superintendence of the quarters of the older pupils, who during class time were his comrades. In the class room his table was in the midst of them; and never had so young a master so much authority, and at the same time so little need for its exercise.

His first taste for chemistry manifested itself by frequent questions addressed during class time to an old professor named Darlay. This questioning was so often repeated that the good man, quite bewildered, ended by declaring that it was for him to interrogate Pasteur and not for Pasteur to interrogate him. His pupil pressed him no further, but having heard that at Besançon there lived an apothecary who had once distinguished himself by a paper inserted in the 'Annales de Chimie et de Physique,' he sought this man, with a view of ascertaining whether, on holidays, he would consent to give him lessons secretly.

At the examination for the École Normale, Pasteur passed as fourteenth in the list. This rank, however, did not satisfy him. Notwithstanding the censure of his fellow candidates he declared that he would begin a new year of preparation. It was in Paris itself that he chose to work—in one of the silent corners of the city, amid the seclusion of preparatory schools and convents.

In the Impasse des Feuillantines, there lived a schoolmaster, M. Barbet by name, or rather le père Barbet, as the Franc-Comtois, with provincial familiarity, used to call him. Pasteur begged to be allowed to enter his institution, not as an assistant, but as a simple pupil. Knowing how slender were the means of his young compatriot, M. Barbet reduced the fees of his pupil by one-third. Such kindness was customary with the père Barbet, who did not like to be reminded of his generosity. This, however, gives double pleasure to him who records it.

The year passes, the time of the examination arrives, and Pasteur is received as fourth on the list. Thus at last, in the month of October 1843, he finds himself in that École Normale in which he was destined to take so great a place. Pasteur's taste for chemistry had become a passion which he could now satisfy to his heart's content. Chemistry was at this time taught at the Sorbonne by M. Dumas and at the École Normale by M. Balard. The pupils of the École attended both courses of lectures. Different as were the two professors, both of them exercised great influence on their pupils. M. Dumas, with his serene gravity and his profound respect for his auditory, never allowed the smallest incorrectness to slip into his exposition. M. Balard, with a vivacity quite juvenile, with the excitement of a southerner in the tribune, did not always give his words time to follow his thoughts. It was he who once, showing a little potash to his audience, exclaimed with a fervour which has become celebrated, 'Potash, which—potash, then—potash, in short, which I now present to you.'

The general principles which M. Dumas in his teaching delighted to develop, the multitude of facts which M. Balard unfolded to his pupils, all answered to the needs of Pasteur's mind. If he loved the vaster horizons of science, he was also possessed by the anxious desire for exactitude, and for the perpetual control of experiment. Each of the lectures of the École Normale and of the Sorbonne excited in him a profound enthusiasm. One day M. Dumas, while illustrating the solidification of carbonic acid, begged for the loan of a handkerchief to receive the carbonic acid snow. Pasteur rushed forward, and, presenting his handkerchief, received the snow. He returned triumphant, and running forthwith to the École Normale, repeated the principal experiments which the illustrious chemist had just exhibited to his audience. He preserved religiously the handkerchief which had been touched by M. Dumas.

Pasteur usually spent his Sundays with M. Barruel, the assistant of M. Dumas. He thought of nothing but experiments. For a long time in one of the laboratories of the École Normale was exhibited a basin—perhaps it is still shown—containing sixty grammes of phosphorus obtained from bones bought at the butcher's by Pasteur. These he had calcined, submitted to the processes known to chemists, and finally reduced, after a whole day's heating, from four in the morning to nine in the evening, to the said sixty grammes. It was the first time that the long manipulations required in the preparation of this simple substance were attempted at the École Normale.

Isolated in laboratory or library, Pasteur's only thought was to search, to learn, to question, and to verify. As the rule of the school leaves much to individual initiative, he devoted himself to his work with a joyful heart. This daily liberty constitutes the charm and the honour of the École Normale. Not only does it permit but it encourages individual effort; it allows the student to visit at his will the library, and to consult there the scientific journals and reviews. This free system of education develops singularly the spirit of research. There is in it an element of superiority over the École Polytechnique. Influenced by its military origin, constrained, moreover, by the number of its pupils to impose on all an exact discipline, and to introduce into their exercises a strict regularity, the École Polytechnique is, perhaps, less calculated than the École Normale to awaken in the minds of its pupils a taste for speculative science. It is certain that Pasteur owed to the freedom of work, and to the facilities for solitary reading which he there enjoyed, the first occasion for an investigation which was the starting-point to a veritable discovery.