154 THE HOUSE FLY—DISEASE CARRIER 
a struggle between them and the prisoners for the 
food. An active prisoner might possibly be able to 
protect his plate from contact with them; but many 
are careless and do not seem to mind much.” Actual 
experiments were made by exposing boiled milk; and 
that exposed on the male side became infected with the 
cholera germ. In conclusion, Macrae writes: 
“The practical lesson the experiments teach is, that 
flies should be looked upon in the light of poisonous 
agencies of the worst kind during cholera epidemics, 
as it is clear that if they find access to poison they will 
carry and distribute it, and every possible means should 
be taken to prevent their getting into contact with either 
food or drink of any kind, and to those having to deal 
with large bodies of men it is a lesson more easily 
learnt than put into practice.” 
Another interesting instance of a somewhat similar 
nature is cited by Nuttall and Jepson, in which they 
state that W. T. Buchanan, in 1897, described a jail 
epidemic which occurred at Burdwan in June, 1896. 
This was also the case of a prison. Outside of the 
prison there were some huts where cholera prevailed. 
It is said that a strong wind blew great numbers of 
flies from the side where these huts were into the prison 
enclosure, where they settled on the food of the pris¬ 
oners. It resulted that only those prisoners who were 
fed at the jail enclosure nearest the huts came down 
with cholera, while the others remained healthy. 
