402 SOME GREAT NAMES IN BIOLOGY 



famous. First as professor at Strassburg and at Lille, later as 

 director of scientific studies in the Ecole Normale at Paris, he 

 showed his interest in the application of his discoveries to human 

 welfare. * 



In 1857 Pasteur showed that fermentation was due to the pres- 

 ence of bacteria, it having been thought up to this time that it 

 was a purely chemical process. This discqyery led to very 

 practical ends, for France was a great wine-producing country, 

 and with a knowledge of the cause of fermentation many of the 

 diseases which spoiled wine were checked. 



In 1865-1868 Pasteur turned his attention to a silkworm dis- 

 ease which threatened to wipe out the silk industry of France and 

 Italy. He found that this disease was caused by bacteria. After 

 a careful study of the case he made certain recommendations 

 which, when carried out, resulted in the complete overthrow of the 

 disease and the saving of millions of dollars to the poor people of 

 France and Italy. 



The greatest service to mankind came later in his life when he 

 applied certain of his discoveries to the treatment of disease. 

 First experimenting upon chickens and later with cattle, he proved 

 that by making a virus (poison) from the germs which caused 

 certain diseases he could reduce this virus to any desired strength. 

 He then inoculated the animals with the virus of reduced strength, 

 giving the inoculated animals a mild attack of the disease, and 

 found that this made them immune from future attacks. This 

 discovery, first applied to chicken cholera, laid the foundation for 

 all future work in the uses of serums, vaccines, and antitoxins. 



Pasteur was perhaps the best known through his study of 

 rabies. The great Pasteur Institute, founded by popular sub- 

 scriptions from all over the world, has successfully treated over 

 22,000 cases of rabies with a death rate of less than 1 per cent. 

 But more than that it has been the place where Roux, a fellow 

 worker with Pasteur, discovered the antitoxin for diphtheria which 

 has resulted in the saving of thousands of human lives. Here 

 also have been established the principles of inoculation against 

 bubonic plague, lockjaw, and other germ diseases. 



Pasteur died in 1895 at the age of seventy-three, " the most 



