CARRIAGE OF DISEASE 117 



The investigation was thorough, and at the annual 

 meeting of the American Medical Association in June, 

 1900, Doctor Vaughan presented a paper entitled ''Con- 

 clusions Reached after a Study of Typhoid Fever 

 among American Soldiers in 1898." This report com- 

 prised fifty-three categorical conclusions. The one re- 

 lating to flies was as follows : 



"27. Flies undoubtedly served as carriers of the in- 

 fection. 



"My reasons for believing that flies were active in 

 the dissemination of typhoid may be stated as fol- 

 lows: 



"a. Flies swarmed over infected fecal matter in the 

 pits and then visited and fed upon the food prepared 

 for the soldiers at the mess tents. In some instances 

 where lime had recently been sprinkled over the con- 

 tents of the pits, flies with their feet whitened with lime 

 were seen walking over the food. 



"b. Officers whose mess tents were protected by 

 means of screens suffered proportionately less from ty- 

 phoid fever than did those whose tents were not so 

 protected. 



"c. Typhoid fever gradually disappeared in the fall 

 of 1898, with the approach of cold weather, and the 

 consequent disabling of the fly. 



"It is possible for the fly to carry the typhoid bacillus 

 in two ways. In the first place, fecal matter containing 

 the typhoid germ may adhere to the fly and be mechan- 

 ically transported. In the second place, it is possible 

 that the typhoid bacillus may be carried in the digestive 



