20 THE UNIVERSITY OF OKLAHOMA 



could he get to Arbois to continue his study of silk worms, as 

 the enemy had overrun his beloved town. So he went to the house 

 of his pupil DuClaux. In March 1871 he wrote to DuClux: "I 

 have my head filled with the finest projects for work but the 

 war has forced my brain to lie hollow. I feel ready now to be- 

 come productive again, although, alas I may be deceiving myself ! 

 How fortunate you are to be young and in good health! Oh! If 

 I could only recommence a new life of study and toil ! Poor 

 France ! Dear mother land !" 



He now turned to a study of beer and soon he announced 

 that all he diseases of beer came from micro-organisms and he 

 showed that if bottled beer was heated to 122°F. it was unalterable. 

 This discovery enabled France to cope with foreign competition. 



Pasteur's next great discovery was with anthrax, by which 

 the herds of cattle and sheep were greatly depleted in France. He 

 took a drop of blood from an infected sheep and placed it in 

 artificial media and after 10 succeeding inoculations he got a cul- 

 ture which produced anthrax in another animal. At the same time 

 he was carrying on a similar research on chicken cholera and with 

 this he discovered, that the germs became attenuated or lost their 

 virulence, when grown on artificial media exposed to the air. These 

 attenuated cholera bacilli when injected into fowls would cause 

 a mild form of cholera which gave immunity to the fatal form of 

 the disease. 



He tried the same experiment with anthrax and found it 

 effective, that is attenuated bacteria when injected caused a mild 

 form of anthrax which made the animals immune. Pasteur an- 

 nounced his experiment on February 28th, 1881. Some received 

 this with enthusiasm, others with distrust. On May 5th, the Soc- 

 iety of Agriculture asked Pasteur to give a public demonstration. 

 For this purpose 50 sheep and 10 cows were placed at his disposal. 

 Twenty-five of the sheep were to be vaccinated with attenuated 

 virus, and then to receive an inoculation, of A'irulent anthrax germs 

 along with the twenty-five uninoculated sheep ; of the ten cows 

 six were vaccinated with attenuated virus and were then given 

 virulent anthrax microbes along vv^ith the four unvaccinated ones. 

 On May 31st, all of the animals were given the virulent anthrax 

 virus. Every one of the unvaccinated animals contracted anthrax 

 and died while not one of the vaccinated animals contracted the 

 disease. ■ This was a great triumph for Pasteur to make this demon- 

 stration before a large throng. Within a year after this demonstra- 

 tion 613,740 sheep and 83,946 cattle had been vaccinated against 

 anthrax in France. By following his method the disease was prac- 



