826 THE POPULAR SCIENCE MONTHLY. 



baffle the microscope ; but that, as the worm grew, they grew also, and 

 appeared, if they existed, large enough to be detected without diffi- 

 culty 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 be- 

 longed 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 

 w T hich demonstrated the inutility of my efforts, and the impossibility 

 of arriving at a practical result in the direction in which I was en- 

 gaged ; and that my ignorance was great on a subject on which stud- 

 ies 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 predic- 

 tion was found to have been exactly fulfilled in twelve out of the four- 

 teen cases. Two additional parcels of eggs, pronounced by him healthy, 

 j)roduced an excellent crop. 



M. Pasteur's researches in fermentation have been practically ap- 

 plied 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 ah*. 



In 1874 the Copley medal of the Royal Society was awarded to M. 

 Pasteur " for his researches on fermentation and pebrine." Mr. Spot- 

 tiswoode, 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 produc- 

 tion, 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- 



