He was already keen in the pursuit of another malady which caused great damage, the “rouget” disease or swine fever. Thuillier, ever ready to start when a demonstration had to be made or an experiment to be attempted, had ascertained, in March, 1882, in a part of the Department of the Vienne, the existence of a microbe in the swine attacked with that disease.
In order to know whether this microbe was the cause of the evil, the usual operations of the sovereign method had to be resorted to. First of all, a culture medium had to be found which was suitable to the micro-organism (veal broth was found to be very successful); then a drop of the culture had to be abstracted from the little phials where the microbe was developing and sown into other flasks; lastly the culture liquid had to be inoculated into swine. Death supervened with all the symptoms of swine fever; the microbe was therefore the cause of the evil? Could it be attenuated and a vaccine obtained? Being pressed to study that disease, and to find the remedy for it, by M. Maucuer, a veterinary surgeon of the Department of Vaucluse, living at Bollène, Pasteur started, accompanied by his nephew, Adrien Loir, and M. Thuillier. The three arrived at Bollène on September 13.
“It is impossible to imagine more obliging kindness than that of those excellent Maucuers,” wrote Pasteur to his wife the next day. “Where, in what dark corner they sleep, in order to give us two bedrooms, mine and another with two beds, I do not like to think. They are young, and have an eight-year-old son at the Avignon College, for whom they have obtained a half-holiday to-day in order that he may be presented to ‘M. Pasteur.’ The two men and I are taken care of in a manner you might envy. It is colder here and more rainy than in Paris. I have a fire in my room, that green oak-wood fire that you will remember we had at the Pont Gisquet.
“I was much pleased to hear that the swine fever is far from being extinguished. There are sick swine everywhere, some dying, some dead, at Bollène and in the country around; the evil is disastrous this year. We saw some dead and dying yesterday afternoon. We have brought here a young hog who is very ill, and this morning we shall attempt vaccination at a M. de Ballincourt’s, who has lost all his pigs, and who has just bought some more in the hope that the vaccine will be preservative. From morning till night we shall be able to watch the disease and to try to prevent it. This reminds me of the pébrine, with pigsties and sick pigs instead of nurseries full of dying silkworms. Not ten thousand, but at least twenty thousand swine have perished, and I am told it is worse still in the Ardèche.”
On the 17th, the day was taken up by the inoculation of some pigs on the estate of M. de la Gardette, a few kilometres from Bollène. In the evening, a former State Councillor, M. de Gaillard, came at the head of a delegation to compliment Pasteur and invite him to a banquet. Pasteur declined this honour, saying he would accept it when the swine fever was conquered. They spoke to him of his past services, but he had no thought for them; like all progress-seeking men, he saw but what was before him. Experiments were being carried out—he had hastened to have an experimental pigsty erected near M. Maucuer’s house—and already, on the 21st, he wrote to Mme. Pasteur, in one of those letters which resembled the loose pages of a laboratory notebook—
“Swine fever is not nearly so obscure to me now, and I am persuaded that with the help of time the scientific and practical problem will be solved.
“Three post-mortem examinations to-day. They take a long time, but that seems of no account to Thuillier, with his cool and patient eagerness.”
Three days later: “I much regret not being able to tell you yet that I am starting back for Paris. It is quite impossible to abandon all these experiments which we have commenced; I should have to return here at least once or twice. The chief thing is that things are getting clearer with every experiment. You know that nowadays a medical knowledge of disease is nothing; it must be prevented beforehand. We are attempting this, and I think I can foresee success; but keep this for yourself and our children. I embrace you all most affectionately.
“P.S.—I have never felt better. Send me 1,000 fr.; I have but 300 fr. left of the 1,600 fr. I brought. Pigs are expensive, and we are killing a great many.”
At last on December 8: “I am sending M. Dumas a note for to-morrow’s meeting at the Academy. If I had time I would transcribe it for the laboratory and for René.”