190 THE HOUSE FLY—DISEASE CARRIER 
that the butchers of Geneva have from time immemorial 
prevented flies from approaching the meat which they 
expose for sale by the use of laurel oil. This oil— 
the odor of which, although a little strong, is not very 
offensive—is said to drive away flies, and they are 
said not to come near walls which have been rubbed 
with it. Furthermore, an item in the Journal of the 
Department of Agriculture of Western Australia states 
that flies may be kept out of stables by using sawdust 
which is saturated with carbolic acid diluted—one part 
of the acid to one hundred parts of the water. It is 
said that this sawdust scattered about stables keeps all 
flies away. 
The idea prevails in some parts of the country that 
the hop vine grown over a country house keeps the 
flies away. Positive testimony to this effect has come 
to the writer from several correspondents, but he has 
not tested it and mentions it on hearsay evidence only. 
An American correspondent who lived in Dalmatia, 
for example, was troubled by flies, and was told by 
natives to grow hop vines over the side of the house 
towards which the flies appeared to come. She did 
so, and states that the fly invasion was stopped after 
the vines reached a certain height. There was, how¬ 
ever, possibly some explanation of this aside from the 
hop plants. 
Search for Breeding Places 
In a general way the character of the breeding places 
of flies has been described in Chapter I, and the state- 
