FOWL CHOLERA. 217 



thoroughly, especially with water acidulated with a 

 little sulphuric acid, or carbolised water with two 

 grammes of acid to the litre. These liquids readily de- 

 stroy the microbe, or at least suspend its development. 

 Thus all causes of contagion disappear, because, during 

 their isolation, the animals already smitten die. The 

 action of the disease, in fact, is very rapid. 



The repeated cultivation of the infectious microbe in 

 the fowl infusion, passing always from one infusion to 

 the next following, by sowing in the latter an infinitely 

 small quantity, so to speak, of the virus as much, for 

 example, as may be retained on the point of a needle 

 simply plunged into the cultivation does not sensibly 

 lessen the virulence of the microscopic organism. Its 

 multiplication inside the bodies of fowls is quite as 

 easy with the last as with the first culture. In short, 

 whatever may be the number of the successive cultures 

 of the microbe in the fowl infusion, the last culture is 

 still very virulent. This proves the microbe to be the 

 cause of the disease a proof the same in kind as that 

 which had already enabled Pasteur to show that 

 splenic fever and septicaemia are produced by specific 

 microbes. 



Like the bacillus of splenic fever, the microbe of 

 the fowl cholera is an aerobic organism. It is culti- 

 vated in contact with the air, or in aerated liquids. 

 At the same time, though it is entitled to be' called an 

 aerobic organism, it differs essentially in certain re- 



