“What a sacrifice I made for you,” he could not help saying to Dumas, with a mixture of affection and deference, and some modesty, for he apparently forgot the immense service rendered to sericiculture, “when I gave up my studies on ferments for five whole years in order to study silkworms!!!”
No doubt a great deal of time was also wasted by the endless discussions entered into by his scientific adversaries; but those discussions certainly brought out and evidenced many guiding facts which are now undisputed, as for instance the following—1. Ferments are living beings. 2. There is a special ferment corresponding to each kind of fermentation. 3. Ferments are not born spontaneously.
Liebig and his partisans had looked upon fermentation as a phenomenon of death; they had thought that beer yeast, and in general all animal and vegetable matter in a state of putrefaction, extended to other bodies its own state of decomposition.
Pasteur, on the contrary, had seen in fermentation a phenomenon correlative with life; he had provoked the complete fermentation of a sweet liquid which contained mineral substances only, by introducing into it a trace of yeast, which, instead of dying, lived, flourished and developed.
To those who, believing in spontaneous generation, saw in fermentations but a question of chance, Pasteur by a series of experimental proofs had shown the origin of their delusion by indicating the door open to germs coming from outside. He had moreover taught the method of pure cultures. Finally, in those recent renewals of old quarrels on the transformations into each other of microscopic species, Pasteur, obliged by the mycoderma vini to study closely its alleged transformation, which he had himself believed possible, had thrown ample light on the only dark spot of his luminous domain.
“It is enough to think,” writes M. Duclaux concerning that long discussion, “we have but to remember that those who denied the specific nature of the germ would now deny the specific nature of disease, in order to understand the darkness in which such opinions would have confined microbian pathology; it was therefore important that they should be uprooted from every mind.”
CHAPTER VIII
1873—1877
Pasteur had glimpses of another world beyond the phenomena of fermentation—the world of virus ferments. Two centuries earlier, an English physicist, Robert Boyle, had said that he who could probe to the bottom the nature of ferments and fermentation would probably be more capable than any one of explaining certain morbid phenomena. These words often recurred to the mind of Pasteur, who had, concerning the problem of contagious diseases, those sudden flashes of light wherein genius is revealed. But, ever insisting on experimental proofs, he constrained his exalted imagination so as to follow calmly and patiently the road of experimental method. He could not bear the slightest error, or even hasty interpretation, in the praises addressed to him. One day, during the period of the most ardent polemics, in the midst of the struggle on spontaneous generation, a medical man named Déclat, who declared that Pasteur’s experiments were “the glory of our century and the salvation of future generations,” gave a lecture on “The Infinitesimally Small and their Rôle in the World.” “After the lecture,” relates Dr. Déclat himself, “M. Pasteur, whom I only knew by name, came to me, and, after the usual compliments, condemned the inductions I had drawn from his experiments. ‘The arguments,’ he said, ‘by which you support my theories, are most ingenious, but not founded on demonstrated facts; analogy is no proof.’”
Pasteur used to speak very modestly of his work. He said, in a speech to some Arbois students, that it was “through assiduous work, with no special gift but that of perseverance joined to an attraction towards all that is great and good,” that he had met with success in his researches. He did not add that an ardent kindness of heart was ever urging him forward. After the services rendered within the last ten years to vinegar makers, silkworm cultivators, vine growers, and brewers, he now wished to tackle what he had had in his mind since 1861—the study of contagious diseases. Thus, with the consistent logic of his mind, showing him as it did the possibility of realizing in the future Robert Boyle’s prophecy, he associated the secret power of his feelings; not to give those feelings their share would be to leave one side of his nature entirely in the shade. He had himself revealed this great factor in his character when he had said, “It would indeed be a grand thing to give the heart its share in the progress of science.” He was ever giving it a greater share in his work.
His sorrows had only made him incline the more towards the griefs of others. The memory of the children he had lost, the mournings he had witnessed, caused him to passionately desire that there might be fewer empty places in desolate homes, and that this might be due to the application of methods derived from his discoveries, of which he foresaw the immense bearings on pathology. Beyond this, patriotism being for him a ruling motive, he thought of the thousands of young men lost to France every year, victims of the tiny germs of murderous diseases. And, at the thought of epidemics and the heavy tax they levy on the whole world, his compassion extended itself to all human suffering.