Nevertheless Pasteur had to go. M. Pouillet gave him a letter for a former Polytechnician,[18] now a civil engineer at Dijon, a M. Parandier, in which he wrote—

“M. Pasteur is a most distinguished young chemist. He has just completed some very remarkable work, and I hope it will not be long before he is sent to a first-class Faculty. I need add nothing else about him; I know no more honest, industrious, or capable young man. Help him as much as you can at Dijon; you will not regret it.”

Those first weeks away from his masters and from his beloved pursuits seemed very hard to Pasteur. But he was anxious to prove himself a good teacher. This duty appeared to him to be a noble ideal, and to involve a wide responsibility. He felt none of the self satisfaction which is sometimes a source of strength to some minds conscious of their superiority to others. He did not even do himself the justice of feeling that he was absolutely sure of his subject. He wrote to Chappuis (November 20, 1848): “I find that preparing my lessons takes up a great deal of time. It is only when I have prepared a lesson very carefully that I succeed in making it very clear and capable of compelling attention. If I neglect it at all I lecture badly and become unintelligible.”

He had both first and second year pupils; these two classes took up all his time and all his strength. He liked the second class; it was not a very large one. “They all work,” Pasteur wrote, “some very intelligently.” As to the first year class, what could he do with eighty pupils? The good ones were kept back by the bad. “Don’t you think,” he wrote, “that it is a mistake not to limit classes to fifty boys at the most? It is with great difficulty that I can secure the attention of all towards the end of the lesson. I have only found one means, which is to multiply experiments at the last moment.”

Whilst he was eagerly and conscientiously giving himself up to his new functions—not without some bitterness, for he really was entitled to an appointment in a Faculty, and he could not pursue his favourite studies—his masters were agitating on his behalf. Balard was clamouring to have him as an assistant at the Ecole Normale. Biot was appealing to Baron Thenard. This scientist was then Chairman of the Grand Council of the Université.[19] He had been a pupil of Vauquelin, a friend of Laplace, and a collaborator of Gay-Lussac; he had lectured during thirty years at the Sorbonne, at the Collège de France, and at the Ecole Polytechnique; he could truthfully boast that he had had 40,000 pupils. He was, like J. B. Dumas, a born professor. But, whilst Dumas was always self possessed and dignified in his demeanour, his very smile serious, Thenard, a native of Burgundy, threw his whole personality into his work, a broad smile on his beaming face.

He was now (1848) seventy years old, and the memory of his teaching, the services rendered to industry by his discoveries, the éclat of his name and titles contrasted with his humble origin, all combined to render him more than a Chancellor of the University; he was in fact a sort of Field Marshal of science, and all powerful. Three years previously he had much scandalized certain red-tape officials by choosing three very young men—Puiseux, Delesse, and H. Sainte Claire Deville—as professors for the new Faculty of Science at Besançon. He had accentuated this authoritative measure by making Sainte Claire Deville Dean of the Faculty. In the unknown professor of twenty-six, he had divined the future celebrated scientist.

At the end of the year 1848 Pasteur solicited the place of assistant to M. Delesse, who was taking a long leave of absence. This would have brought him near Arbois, besides placing him in a Faculty. He asked for nothing more. Thenard, who had Biot’s report in his hands, undertook to transmit to the Minister this modest and natural request. He was opposed by an unexpected argument—the presentation of assistantships belonged to each Faculty. This custom was unknown to Pasteur. Thenard was unable to overcome this routine formality. Pasteur thought that the unanimous opinion of Thenard, Biot, and Pouillet ought to have prevailed. “I can practically do nothing here,” he wrote on the sixth of December, thinking of his interrupted studies. “If I cannot go to Besançon, I shall go back to Paris as a curator.”

His father, to whom he paid a visit for the new year, persuaded him to look upon things more calmly, telling him that wisdom repudiated too much hurry. Louis deferred to his father’s opinion to the extent of writing, on January 2, 1849, to the Minister of Public Instruction, begging him to overlook his request. However, the members of the Institute who had taken up his cause did not intend to be thwarted by minor difficulties. Pasteur’s letter was hardly posted when he received an assistantship, not at the Besançon Faculty but at Strasburg, to take the place of M. Persoz, Professor of Chemistry, who was desirous of going to Paris.

Pasteur, on his arrival at Strasburg (January 15) was welcomed by the Professor of Physics, his old school friend, the Franc-Comtois Bertin. “First of all, you are coming to live with me,” said Bertin gleefully. “You could not do better; it is a stone’s throw from the Faculté.” By living with Bertin, Pasteur acquired a companion endowed with a rare combination of qualities—a quick wit and an affectionate heart. Bertin was too shrewd to be duped, and a malicious twinkle often lit up his kindly expression; with one apparently careless word, he would hit the weak point of the most self satisfied. He loved those who were simple and true, hence his affection for Pasteur. His smiling philosophy contrasted with Pasteur’s robust faith and ardent impetuosity. Pasteur admired, but did not often imitate, the peaceful manner with which Bertin, affirming that a disappointment often proved to be a blessing in disguise, accepted things as they came. In order to prove that this was no paradox, Bertin used to tell what had happened to him in 1839, when he was mathematical preparation master at the College of Luxeuil. He was entitled to 200 francs a month, but payment was refused him. This injustice did not cause him to recriminate, but he quietly tendered his resignation. He went in for the Ecole Normale examination, entered the school at the head of the list, and subsequently became Professor of Physics at the Strasburg Faculty. “If it had not been for my former disappointment, I should still be at Luxeuil.” He was now perfectly satisfied, thinking that nothing could be better than to be a Professor in a Faculty; but this absence of any sort of ambition did not prevent him from giving his teaching the most scrupulous attention. He prepared his lessons with extreme care, endeavouring to render them absolutely clear. He took great personal interest in his pupils, and often helped them with his advice in the interval between class hours. This excellent man’s whole life was spent in working for others, and to be useful was ever to him the greatest satisfaction.

Perhaps Pasteur was stimulated by Bertin’s example to give excessive importance to minor matters in his first lessons. He writes: “I gave too much thought to the style of my two first lectures, and they were anything but good; but I think the subsequent ones were more satisfactory, and I feel I am improving.” His lectures were well attended, for the numerous industries of Alsace gave to chemistry quite a place by itself.