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 foi 1 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 
