The father would often sit up late at night over rules of grammar and mathematical problems, preparing answers to send to his boy in Paris.
Some Arboisians, quite forgotten now, imagined that they would add lustre to the local history. General Baron Delort, a peer of France,[11] aide de camp to Louis Philippe, Grand Cross of the Legion of Honour and the first personage in Arbois—where he beguiled his old age by translating Horace—used to go across the Cuisance bridge without so much as glancing at the tannery where the Pasteur family lived. Whilst the general in his thoughts bequeathed to the town of Arbois his books, his papers, his decorations, even his uniform, he was far from foreseeing that the little dwelling by the bridge would one day become the cynosure of all eyes.
Months went by and happy items of news succeeded one another. The Normalien was chiefly interested in the transformations of matter, and was practising in order to become capable of assisting in experiments; difficulties only stimulated him. At the chemistry class that he attended, the process of obtaining phosphorus was merely explained, on account of the length of time necessary to obtain this elementary substance; Pasteur, with his patience and desire for proven knowledge, was not satisfied. He therefore bought some bones, burnt them, reduced them to a very fine ash, treated this ash with sulphuric acid, and carefully brought the process to its close. What a triumph it seemed to him when he had in his possession sixty grammes of phosphorus, extracted from bones, which he could put into a phial labelled “phosphorus.” This was his first scientific joy.
Whilst his comrades ironically (but with some discernment) called him a “laboratory pillar,” some of them, more intent upon their examinations, were getting ahead of him.—M. Darboux, the present “doyen” of the Faculty[12] of Science, finds in the Sorbonne registers that Pasteur was placed 7th at the licence examination; two other students having obtained equal marks with him, the jury (Balard, Dumas and Delafosse), mentioned his name after theirs.
Those who care for archives would find in the Journal Général de l’Instruction Publique of September 17, 1846, a report of the agrégation[13] competition (physical science). Out of fourteen candidates only four passed and Pasteur was the third. His lessons on physics and chemistry caused the jury to say, “He will make an excellent professor.”
Many Normaliens of that time fancied themselves called to a destiny infinitely superior to his. Some of them, in later times, used to complacently allude to this momentary superiority when speaking to their pupils. Of all Pasteur’s acquaintances Chappuis was the only one who divined the future. “You will see what Pasteur will be,” he used to say, with an assurance generally attributed to friendly partiality. Chappuis—Pasteur’s confidant—was well aware of his friend’s powers of concentration.
Balard also realised this; he had the happy idea of taking the young agrégé into his laboratory, and intervened vehemently when the Minister of Public Instruction desired—a few months later—that Pasteur should teach physics in the Tournon Lycée. It would be rank folly, Balard declared, to send 500 kilometres away from Paris a youth who only asked for the modest title of curator, and had no ambition but to work from morning till night, preparing for his doctor’s degree. There would be time to send him away later on. It was impossible to resist this torrent of words founded on solid sense. Balard prevailed.
Pasteur was profoundly grateful to him for preserving him from exile to the little town in Ardèche; and, as he added to his Franc-Comtois patience and reflective mind a childlike heart and deep enthusiasm, he was delighted to remain with a master like Balard, who had become celebrated, at the age of twenty-four, as the discoverer of bromin.
At the end of 1846, a newcomer entered Balard’s laboratory, a strange delicate-looking man, whose ardent eyes were at the same time proud and yet anxious. This man, a scientist and a poet, was a professor of the Bordeaux Faculty, named Auguste Laurent. Perhaps he had had some friction with his Bordeaux chiefs, possibly he merely wished for a change; at all events, he now desired to live in Paris. Laurent was already known in the scientific world, and had recently been made a correspondent of the Académie des Sciences. He had foreseen and confirmed the theory of substitutions, formulated by Dumas as early as 1834 before the Académie. Dumas had expressed himself thus: “Chlorine possesses the singular power of seizing upon the hydrogen in certain substances, and of taking its place atom by atom.”
This theory of substitutions was—according to a simple and vivid comparison of Pasteur’s—a way of looking upon chemical bodies as upon “molecular edifices, in which one element could be replaced by another without disturbing the structure of the edifice; as if one were to replace, one by one, every stone of a monument by a new stone.” Original researches, new and bold ideas, appealed to Pasteur. But his cautious mind prevented his boldness from leading him into errors, surprises or hasty conclusions. “That is possible,” he would say, “but we must look more deeply into the subject.”