102 The Story of the Bacteria 



absorbed, just as some kinds of food might 

 be, and carried to various parts of the body, 

 producing effects which we recognize as 

 symptoms of the disease. 



The great and important source of in- 

 fection the means by which the disease is 

 usually spread is these discharges from the 

 bowels and the urine containing the living, 

 virulent typhoid bacilli. 



Here we have an essentially similar con- 

 dition of affairs to that in tuberculosis, namely, 

 bacteria of a particular species inducing a 

 disease which, without them, could not or 

 does not, so far as we know, occur and after 

 inducing the disease in an individual, being 

 discharged alive and virulent from the body. 

 Here, as in tuberculosis, although the mode of 

 infection is somewhat different, if all the dis- 

 charges from persons suffering from the dis- 

 ease could be immediately destroyed, all 

 danger of infection, so far as we know, would 

 be removed. Typhoid fever is thus a com- 

 municable and a preventable disease. 



Typhoid fever affects man alone, and he 

 alone forms the source of infection. But, 



