u8 INFECTION AND IMMUNITY 



of a malady which he considers trivial, and, instead 

 of being isolated and properly treated as he should 

 be in his own interest and that of the public gener- 

 ally, he goes from town to town or from country to 

 country distributing cholera germs by the way. 



Cholera is contracted only by the introduction of 

 cholera germs into the intestinal canal by way of the 

 mouth and stomach. The spirillum is easily destroyed 

 by acids, and consequently does not multiply in the 

 healthy human stomach, and, under ordinary condi- 

 tions, probably does not survive to reach the intes- 

 tine, owing to the germicidal action of the acid gastric 

 juice. But any derangement of the digestive process 

 predisposes to an attack of the disease. Excesses in 

 eating or drinking cause the individual to be more 

 susceptible to infection. In Germany it has been 

 noted that an increase in the number of cases is 

 likely to occur on Sunday, because of the indulgence 

 of the labouring classes in wine and beer during this 

 day of rest and recreation. 



Invalids, and especially those subject to disorders 

 of the stomach and bowels, are especially liable to 

 contract the disease during its epidemic prevalence. 

 But it is safe to say that no one will contract cholera 

 unless living cholera germs are introduced into the 

 intestinal canal. This usually occurs as a result of 

 drinking cholera-infected water, or partaking of food 



