THE BACTERIA IN CONTAGIOUS MALADIES. 161 



into the blood of sheep and of rabbits, these cor- 

 puscles produced death with the symptoms of 

 charbon, and the blood of the animals presented 

 numerous bacteria. The appearance of spores in 

 the liquid under cultivation, containing bacteria, 

 occurs in twenty-four hours at 35° (95° Fah.), in 

 three days at 18° ; above 45° and below 12° it is 

 no longer possible. Once produced these spores 

 resist putrefaction, desiccation, and alternation of 

 humidity and dryness, during several years. On 

 the contrary, the adult form of the Bacillus an- 

 thracis dies under the influence of putrefaction 

 and of oscillations of temperature. It has not 

 seemed to develop itself in the dog, the cat, birds, 

 and cold-blooded animals. The immunity which 

 these enjoy has recently been the object of a study 

 by Pasteur, Joubert, and Chamberlain. Believing 

 that it might be attributed to their temperature, 

 incompatible with the life of the bacteria, they 

 have refrigerated a fowl, and have ascertained that 

 it lost this immunity. Besides, by placing the 

 infected animal in an oven at 30° (86° Fah.) they 

 have seen the temperature come back rapidly to 

 the normal and the symptoms of charbon to re- 

 cede. 



The labors, then, of Koch add an additional 

 element of probability in favor of the parasitic 

 theory. They show us the existence of an organ- 

 ism which we would be able to invoke as the cause 

 of spontaneous epizootics. 



All these results Cohn of Breslau has obtained 

 upon repeating the experiments of his compatriot. 



11 



