Baron de la Rochette was a typical old French gentleman; his whole person was an ideal of old-time distinction and courtesy. Well up to date in all agricultural progress, and justly priding himself, with the ease of a great landowner, that he made of agriculture an art and a science, he could speak in any surroundings with knowledge of his subject and a winning grace of manner. When he entered the laboratory, he was at once charmed by the simplicity of the scientist, who hastened to accept the proposal of an extensive experiment. At the end of April, Pasteur wrote out the programme which was to be followed near Melun at the farm of Pouilly le Fort. M. Rossignol had a number of copies of that programme printed, and distributed them, not only throughout the Department of Seine et Marne, but in the whole agricultural world. This programme was so decidedly affirmative that some one said to Pasteur, with a little anxiety: “You remember what Marshal Gouyion St. Cyr said of Napoleon, that ‘he liked hazardous games with a character of grandeur and audacity.’ It was neck or nothing with him; you are going on in the same way!” “Yes,” answered Pasteur, who meant to compel a victory. And as his collaborators, to whom he had just read the precise and strict arrangements he had made, themselves felt a little nervous, he said to them, “What has succeeded in the laboratory on fourteen sheep will succeed just as well at Melun on fifty.” This programme left him no retreat. The Melun Agricultural Society put sixty sheep at Pasteur’s disposal; twenty-five were to be vaccinated by two inoculations, at twelve or fifteen days’ interval, with some attenuated charbon virus. Some days later those twenty-five and also twenty-five others would be inoculated with some very virulent charbon culture. “The twenty-five unvaccinated sheep will all perish,” wrote Pasteur, “the twenty-five vaccinated ones will survive.” They would afterwards be compared with the ten sheep which had undergone no treatment at all. It would thus be seen that vaccination did not prevent sheep from returning to their normal state of health after a certain time. Then came other prescriptions, for instance, the burying of the dead sheep in distinct graves, near each other and enclosed within a paling. “In May, 1882,” added Pasteur, “twenty new sheep, that is, sheep never before used for experimentation, will be shut within that paling.” And he predicted that the following year, 1882, out of those twenty-five sheep fed on the grass of that little enclosure or on forage deposited there, several would become infected by the charbon germs brought to the surface by earthworms, and that they would die of splenic fever. Finally, twenty-five other sheep might be folded in a neighbouring spot, where no charbon victims had ever been buried, and under these conditions none would contract the disease.