In 1869 a scientific congress was held at Chartres; one of the questions examined being this: “What has been done to oppose splenic fever in sheep?” A veterinary surgeon enumerated the causes which contributed, according to him, to produce and augment mortality by splenic fever: bad hygienic conditions; tainted food, musty or cryptogamized; heated and vitiated air in the crowded pens, full of putrid manure; paludic miasma or effluvia; damp soil flooded by storms, etc., etc. A well-known veterinary surgeon, M. Boutet, saw no other means to preserve what remained of a stricken flock but to take it to another soil, which, in contradiction with his colleague, he thought should be chosen cool and damp. No conclusion could be drawn. The disastrous loss caused by splenic fever in the Beauce alone was terrible; it was said to have reached 20,000,000 francs in some particularly bad years. The migration of the tainted flock seemed the only remedy, but it was difficult in practice and offered danger to other flocks, as carcases of dead sheep were wont to mark the road that had been followed.
Pasteur, starting from the fact that the charbon disease is produced by the bacteridium, proposed to prove that, in a department like that of Eure et Loir, the disease maintained itself by itself. When an animal dies of splenic fever in a field, it is frequently buried in the very spot where it fell; thus a focus of contagion is created, due to the anthrax spores mixed with the earth where other flocks are brought to graze. Those germs, thought Pasteur, are probably like the germs of the flachery vibrio, which survive from one year to another and transmit the disease. He proposed to study the disease on the spot.
It almost always happened that, when he was most anxious to give himself up entirely to the study of a problem, some new discussion was started to hinder him. He had certainly thought that the experimental power of giving anthrax to hens had been fully demonstrated, and that that question was dead, as dead as the inoculated and immersed hen.
Colin, however, returned to the subject, and at an Academy meeting of July 9 said somewhat insolently, “I wish we could have seen the bacteridia of that dead hen which M. Pasteur showed us without taking it out of its cage, and which he took away intact instead of making us witness the necropsy and microscopical examination.” “I will take no notice,” said Pasteur at the following meeting, “of the malevolent insinuations contained in that sentence, and only consider M. Colin’s desire to hold in his hands the body of a hen dead of anthrax, full of bacteridia. I will, therefore, ask M. Colin if he will accept such a hen under the following condition: the necropsy and microscopic examination shall be made by himself, in my presence, and in that of one of our colleagues of this Academy, designated by himself or by this Academy, and an official report shall be drawn up and signed by the persons present. So shall it be well and duly stated that M. Colin’s conclusions, in his paper of May 14, are null and void. The Academy will understand my insistence in rejecting M. Colin’s superficial contradictions.
“I say it here with no sham modesty: I have always considered that my only right to a seat in this place is that given me by your great kindness, for I have no medical or veterinary knowledge. I therefore consider that I must be more scrupulously exact than any one else in the presentations which I have the honour to make to you; I should promptly lose all credit if I brought you erroneous or merely doubtful facts. If ever I am mistaken, a thing which may happen to the most scrupulous, it is because my good faith has been greatly surprised.
“On the other hand, I have come amongst you with a programme to follow which demands accuracy at every step. I can tell you my programme in two words: I have sought for twenty years, and I am still seeking, spontaneous generation properly so called.
“If God permit, I shall seek for twenty years and more the spontaneous generation of transmissible diseases.
“In these difficult researches, whilst sternly deprecating frivolous contradiction, I only feel esteem and gratitude towards those who may warn me if I should be in error.”
The Academy decided that the necropsy and microscopic examination of the dead hen which Pasteur was to bring to Colin should take place in the presence of a Commission composed of Pasteur, Colin, Davaine, Bouley, and Vulpian. This Commission met on the following Saturday, July 20, in the Council Chamber of the Academy of Medicine. M. Armand Moreau, a member of the Academy, joined the five members present, partly out of curiosity, and partly because he had special reasons for wishing to speak to Pasteur after the meeting.
Three hens were lying on the table, all of them dead. The first one had been inoculated under the thorax with five drops of yeast water slightly alkalized, which had been given as a nutritive medium to some bacteridia anthracis; the hen had been placed in a bath at 25° C., and had died within twenty-two hours. The second one, inoculated with ten drops of a culture liquid, had been placed in a warmer bath, 30° C., and had died in thirty-six hours. The third hen, also inoculated and immersed, had died in forty-six hours.