124 PASTEUR 



point in the discussion, with the two sides 

 steadfastly maintaining contradictory opinions, 

 each supported equally by facts, that Pasteur, 

 in collaboration with Messrs. Joubert, Cham- 

 berland and Roux, intervened in his accustomed 

 manner, quite simple, quite clear and rigor- 

 ously scientific. 



Having obtained a fresh drop of blood from 

 an animal infected with anthrax, Pasteur culti- 

 vated the bacterides in artificial mediums by 

 impregnating each new medium with a drop 

 taken from the preceding culture, so that by 

 the time of the tenth culture he obtained pure 

 bacterides. When these were used for inocu- 

 lation they produced anthrax, without the aid 

 of the original drop of blood, which had dis- 

 appeared through being diluted to such a de- 

 gree as to be imperceptible in the later cultures. 

 This amounted to a complete confirmation of 

 Davaine's opinion, that these bacterides were 

 the cause of the disease of anthrax. In order 

 to render his experiment more decisive Pasteur 

 established a counter-proof by inoculating his 



