baffle the microscope; but that, as the worm grew, they grew also, and appeared, if they existed, large enough to be detected without difficulty in the moth.
Pasteur's first communication on the facts he had discovered, made to the French Academy of Sciences, in September, 1865, called out some rather sharp criticism on the presumption of the chemist who had ventured to instruct physicians and biologists on a subject that belonged to them. "They found it strange," he says, "that I was so little in the current on the question. They set against me works which had been appearing for a considerable time in Italy, the conclusions of which demonstrated the inutility of my efforts, and the impossibility of arriving at a practical result in the direction in which I was engaged; and that my ignorance was great on a subject on which studies without number had appeared during the last fifteen years." If the scientific men were thus disposed to reject his new truths, it was hardly to be expected that the cultivators would accept his guidance in a direction contrary to that in which they were going. To strike their imagination, and, if possible, determine their practice, he hit upon the expedient of prophecy. Having inspected fourteen parcels of eggs, and examined the condition of the moths which produced them, in 1866, he wrote out predictions of what would be the fate of the lot in 1867, and placed it as a sealed letter in the hands of the Mayor of St. Hippolyte. When the reports of the cultivators were compared with the forecasts in the letter, in the next year, his prediction was found to have been exactly fulfilled in twelve out of the fourteen cases. Two additional parcels of eggs, pronounced by him healthy, produced an excellent crop.
M. Pasteur's researches in fermentation have been practically applied by him in his process for preserving wines by the application of heat, and his process for manufacturing beer by fermentation sheltered from all contact with air.
In 1874 the Copley medal of the Royal Society was awarded to M. Pasteur "for his researches on fermentation and pébrine." Mr. Spottiswoode, in making the presentation, observed that Professor Pasteur's researches on fermentation consisted essentially of two parts, the first part embracing the examination of the products, and the second the causes of fermentation. Previous observers had noticed the production, in solutions of sugar which had been fermented, of substances other than the two commonly recognized, alcohol and carbonic acid; but it remained for M. Pasteur to show which were essential and which were occasional products. In regard to the cause of fermentation, "it had been found that certain solutions, when exposed to the air, soon became full of living organisms; and Pasteur's experiments led him to support the view that these organisms originated from the presence of germs floating in the air. He found that no living organisms were developed if care were taken to destroy all those which might be pres-
