VIRULENT DISEASES. 211 



ferences do they warrant as to the influence of external 

 media and conditions upon the life and develop- 

 ment of living contagia ! There have been great dis- 

 cussions in Germany and France upon a mode of 

 treatment in typhoid fever, which consists in cooling 

 the body of the patient by frequently repeated baths. 

 The possible good effects of this treatment may be 

 understood when viewed in conjunction with the fore- 

 going experiment on fowls. In typhoid fever the cold 

 arrests the fermentation, which may be regarded as at 

 once the expression and the cause of the disease, just 

 as, by an inverse process, the heat of the body arrests 

 the development of the splenic fever microbe in the 

 hen. 



