Pasteur had also brought Biot some other products—a case full of new crystals. Starting from the external configuration of crystals, he penetrated the individual constitution of their molecular groups, and from this point of departure, he then had recourse to the resources of chemistry and optics. Biot never ceased to admire the sagacity of the young experimentalist who had turned what had until then been a mere crystallographic character into an element of chemical research.
Equally interested by the general consequences of these studies, so delicate and so precise, M. de Senarmont wished in his turn to examine the crystals. No one approved more fully than he the expressions of the old scientist, who ended in this way his 1851 report: “If M. Pasteur persists in the road he has opened, it may be predicted of him that what he has found is nothing to what he will find.” And, delighted to see the important position that Pasteur was taking at Strasburg and the unexpected extension of crystallography, Biot wrote to him: “I have read with much interest the thesis of your brother-in-law, M. Loir. It is well conceived and well written, and he establishes with clearness many very curious facts. M. de Senarmont has also read it with very great pleasure, and I beg you will transmit our united congratulations to your brother-in-law.” Biot added, mixing as he was wont family details with scientific ideas: “We highly appreciated your father, the rectitude of his judgment, his firm, calm, simple reason and the enlightened love he bears you.”
“My plan of study is traced for this coming year,” wrote Pasteur to Chappuis at the end of December. “I am hoping to develop it shortly in the most successful manner.... I think I have already told you that I am on the verge of mysteries, and that the veil which covers them is getting thinner and thinner. The nights seem to me too long, yet I do not complain, for I prepare my lectures easily, and often have five whole days a week that I can give up to the laboratory. I am often scolded by Mme. Pasteur, but I console her by telling her that I shall lead her to fame.”
He already foresaw the greatness of his work. However he dare not speak of it, and kept his secret, save with the confidante who was now a collaborator, ever ready to act as secretary, watching over the precious health of which he himself took no account, an admirable helpmeet, to whom might be applied the Roman definition, socia rei humanæ atque divinæ. Never did life shower more affection upon a man. Everything at that time smiled upon him. Two fair children in the home, great security in his work, no enemies, and the comfort of receiving the approval and counsel of masters who inspired him with a feeling of veneration.
“At my age,” wrote Biot to Pasteur, “one lives only in the interest one takes in those one loves. You are one of the small number who can provide such food for my mind.” And alluding in that same letter (December 22, 1851) to four reports successively approved of by Balard, Dumas, Regnault, Chevreul, Senarmont and Thenard: “I was very happy to see, in those successive announcements of ideas of so new and so far-reaching a nature, that you have said—and that we have made you say—nothing that should now be contradicted or objected to in one single point. I still have in my hands the pages of your last paper concerning the optical study of malic acid. I have not yet returned them to you, as I wish to extract from them some results that I shall place to your credit in a paper I am now writing.”
It was no longer Biot and Senarmont only who were watching the growing importance of Pasteur’s work. At the beginning of the year 1852 the physicist Regnault thought of making Pasteur a corresponding member of the Institute. Pasteur was still under thirty. There was a vacancy in the General Physics section, why not offer it to him? said Regnault, with his usual kindliness. Biot shook his head: “It is to the Chemistry section that he ought to belong.” And, with the courage of sincere affection, he wrote to Pasteur, “Your work marks your place in chemistry rather than physics, for in chemistry you are in the front rank of inventors, whilst in physics you have applied processes already known rather than invented new ones. Do not listen to people, who, without knowing the ground, would cause you to desire, and even to hastily obtain, a distinction which would be above your real and recognized claims.... Besides, you can see for yourself how much your work of the last four years has raised you in every one’s estimation. And that place, which you have made for yourself in the general esteem, has the advantage of not being subject to the fluctuations of the ballot. Farewell, dear friend, write to me when you have time, and be assured that my interest in hard workers is about the only thing which yet makes me wish to live. Your friend.”
Pasteur gratefully accepted these wise counsels. In an excess of modesty, he wrote to Dumas that he should not apply as candidate even if a place for a correspondent were vacant in the Chemistry section. “Do you then believe,” answered Dumas with a vivacity very unlike his usual solemn calmness, “do you believe that we are insensible to the glory which your work reflects on French chemistry, and on the Ecole from whence you come? The very day I entered the Ministry, I asked for the Cross[22] for you. I should have had in giving it to you myself a satisfaction which you cannot conceive. I don’t know whence the delay and difficulty arise. But what I do know is that you make my blood boil when you speak in your letter of the necessity of leaving a free place in chemistry to the men you mention, one or two excepted.... What opinion have you then of our judgment? When there is a vacant place, you shall be presented, supported and elected. It is a question of justice and of the great interests of science: we shall make them prevail.... When the day comes, there will be means found to do what is required for the interests of science, of which you are one of the firmest pillars, and one of the most glorious hopes. Heartily yours.”
“My dear father,” wrote Pasteur, sending his father a copy of this letter, “I hope you will be proud of M. Dumas’ letter. It surprised me very much. I did not believe that my work deserved such a splendid testimony, though I recognize its great importance.”
Thus were associated in Pasteur the full consciousness of his great mental power with an extreme ingenuousness. Instead of the pride and egotism provoked, almost excusably, in so many superior men by excessive strength, his character presented the noblest delicacy.
Another arrangement occurred to Regnault: that he himself should accept the direction of the Sèvres Manufactory, and give up to Pasteur his professorship at the Ecole Polytechnique. Others suggested that Pasteur should become chief lecturer at the Ecole Normale. Rumours of these possibilities reached Strasburg, but Pasteur’s thoughts were otherwise absorbed. He was concerned with the manner in which he could modify the crystalline forms of certain substances which, though optically active, did not at the first view present the hemihedral character, and with the possibility of provoking the significant faces by varying the nature of the dissolving agents. Biot was anxious that he should not be disturbed in these ingenious researches, and advised him to remain at Strasburg in terms as vigorous as any of his previous advice. “As to the accidents which come from or depend on men’s caprice, be strong-minded enough to disdain them yet awhile. Do not trouble about anything, but pursue indefatigably your great career. You will be rewarded in the end, the more certainly and unquestionably that you will have deserved it more fully. The time is not far when those who can serve you efficiently will feel as much pride in doing so as shame and embarrassment in not having done so already.”