CONFLICT OF THE AIICROBE WITH THE ORGANISM 255 



as Koch had seen, and must have contact with oxygen 

 in order to live. Therefore, as soon as the bacteria 

 reach the blood they struggle with the red corpuscles 

 for the possession of this gas, and, consequently, the 

 latter are asphyxiated. Thus, clearly, originates the 

 black color of the blood and viscera at the moment 

 of death, which is one of the most marked character- 

 istics of anthrax. 



These corpuscles of anthrax blood are, furthermore, 

 agglutinated and massed together. Why? Because 

 of a secretion of the bacteria. Anthrax serum filtered 

 and mixed with fresh normal blood agglutinates the 

 corpuscles as much and even more than occurs natu- 

 rally in the disease, due, without doubt, to a diastase 

 which the bacteria have secreted in the culture medium. 

 Here we have the first example introduced into science 

 of a bacterial secretion producing one of the symptoms 

 of a disease. 



The second, still more striking, was taken some months 

 later from the history of chicken cholera. One of the 

 most curious symptoms of this disease is the uncon- 

 querable somnolency which overtakes the diseased 

 fowls. But one can produce a somnolence entirely 

 similar though less profound by inoculating a healthy 

 animal with a filtered culture of the microbe of chicken 

 cholera. The filtered liquid is free from the microbe 

 but contains substances secreted by it, which we call 

 to-day its toxines, and this word alone is sufficient to 

 recall all that has sprung with time from this fundamen- 

 tal observation of Pasteur concerning which we have 

 just spoken. 



We are not yet done with this note of the 16th of July, 

 1877, from which we have derived the preceding facts. 

 There are some species of animals which are refractory to 

 anthrax. Such are the birds. Nevertheless the blood 



