182 THE HOUSE FLY—DISEASE CARRIER 
“After the traps have been attached, some substance 
should be put into them that will either kill the insect 
upon falling into it, or on account of its sticky nature 
will hold the insect so that it cannot escape. For the 
first, kerosene, kerosene emulsion, soapsuds and py- 
rethrum are the best; and for the second, molasses, or 
a mixture of castor-oil and resin. For general use, the 
soapsuds are to be recommended. When using the 
liquids, fill the traps two-thirds full. 
“There should be one trap for every pane of glass 
of at least one window in the house. For instance, 
when the sash contains two panes of glass, as in the 
cut, there should be two traps, one at the base of each 
pane. When the sash contains four panes, there should 
be four traps, two on the bottom rail and two on the 
cross-bars or munting. It is not necessary to apply 
traps to all the windows. Attach traps to one or two 
windows in the sunny part of the house, and pull down 
the blinds of the remaining windows. The flies will 
seek the lighted rooms, and especially the windows. 
“When the traps are full of flies, remove them from 
their fastenings, empty out their contents, and fill them 
with fresh material. 
“A temporary trap can be made of flexible card¬ 
board, following the same directions as for those made 
of tin. Use glue or pins to fasten the ends. To render 
the trap water-proof, paint the inside with melted par¬ 
affin. This will hold any of the above remedies except 
the pure kerosene.” 
A correspondent, Dr. D. S. Hager, has made a sue- 
