CARRIAGE OF DISEASE 115 



There was nothing in common in the milk supply of 

 the different houses, and as there was no well liable 

 to contamination from the first source, it is not im- 

 probable that the infection was conveyed in the man- 

 ner indicated." 



Writing of nine cases occurring in a certain locality 

 in Washington, he says, "There was nothing in com- 

 mon in the milk supply, and the fact that the cases oc- 

 curred at considerable intervals indicates with more 

 or less certainty that the first case was a focus of in- 

 fection; but how the germs were carried, unless by 

 flies, or through the air, is a matter impossible to de- 

 termine." Later, in writing of methods for the dis- 

 posal of human excreta, he says, "These boxes, even 

 if there are no wells, are still a source of danger in 

 so far as they favor the transmission of germs by 

 means of infected flies." In his conclusion, he writes, 

 "A large percentage of the cases occurred in houses 

 supplied with box privies which, apart from being an 

 important cause of soil pollution, are believed to be 

 otherwise instrumental in the dissemination of germs, 

 chiefly through the agency of flies." 



The attention of all interested was riveted to the 

 question of the agency of flies by the results of the 

 investigations carried on during the Spanish-American 

 War in 1898. In his first circular of directions to army 

 surgeons, the Surgeon-General of the Army, Dr. 

 George M. Sternberg, gave explicit directions regard- 

 ing sinks, which, if followed carefully, would have pre- 

 vented the spread of typhoid by flies, and he definitely 



