ANTISEPTIC SURGERY 153 



as the result of possession by an evil spirit, and the 

 practice of the medicine man, who is frequently also 

 the priest, commonly consists in inducing the evil 

 spirits by supplications, bribes, or threats to leave 

 the body of the afflicted person. There has come 

 down to us from primitive times as a part of the 

 intellectual heritage of the race, a semi-supersti- 

 tious attitude in regard to the healing art that even 

 now betrays itself in a variety of ways. Epidemics 

 a half century ago were entirely mysterious. Medi- 

 cal men in general vaguely conceived of disease as 

 due to some subtle "morbid matter," which could 

 be spread by contact or through the air and which 

 had the power of multiplying itself in the body. 

 Many had from time to time speculated on the pos- 

 sibility that diseases might be caused by living 

 germs, but in the absence of any thorough-going 

 experimental tests the doctrine remained as a mere 

 plausible conjecture. Pasteur's work on fermenta- 

 tion and spontaneous generation brought the "germ 

 theory," as it was called, more prominently before 

 the public. The germ theory had been demon- 

 strated for the maladies of wines and beers and 

 later for those of silk worms and the analogy of 

 these phenomena to infectious diseases of man and 

 the higher animals could scarcely be overlooked. 



