194 THE HOUSE FLY—DISEASE CARRIER 
whether it would be possible to treat a manure pile in 
such a way as to stop the breeding of flies. Previous 
experience with the use of air-slaked lime on cow 
manure to prevent the breeding of the horn fly sug¬ 
gested the experimentation with different lime com¬ 
pounds. It was found to be perfectly impracticable 
to use air-slaked lime, land plaster, or gas lime with 
good results. Few or no larvae were killed by a thor¬ 
ough mixture of the manure with any of these sub¬ 
stances. 
Chloride of lime, however, was found to be an ex¬ 
cellent maggot-killer. Where one pound of chloride 
of lime was mixed with eight quarts of horse manure, 
ninety per cent, of the maggots were killed in less than 
twenty-four hours. At the rate of a quarter of a pound 
of chloride of lime to eight quarts of manure, however, 
the substance was not sufficiently strong. Chloride of 
lime, although cheap in Europe, costs at least three and 
one-half cents a pound in large quantities in this coun¬ 
try, so that frequent treatment of a large manure pile 
with this substance would be out of the question in ac¬ 
tual practice. Moreover, if the manure receptacle is in 
the stable where horses are kept, or in close proximity 
to it, the chlorine fumes arising from a pile thus treated 
would be an irritant to the eyes of the live stock. 
After these experiments with lime, kerosene was 
used. It was found that eight quarts of fresh horse 
manure sprayed with one pint of kerosene which was 
afterwards washed down with one quart of water was 
thoroughly rid of living maggots—every individual 
