THEIR RELATION TO MAN 213 



The one uniform requirement for development — water in 

 which they may breed — gives us the clew to the method 

 of control, and our efforts should be intelligently directed 

 to eliminating such places by draining or filling rather 

 than to destroying the larvae after they have begun to 

 develop. 



Sometimes, where it is recognized that mosquitoes 

 are hibernating in numbers in a house or cellar, it may 

 become desirable to attempt their destruction during 

 the winter. This can be accomplished by fumigation 

 with either stramonium or culicide. Stramonium is 

 simply the powdered leaves of "jimpson weed," which 

 grows almost everywhere within the United States, and 

 it is made up with one-third its weight of saltpetre to 

 make it bum better. Eight ounces of good stramonium 

 is sufficient for 1000 cubic feet of space and the fumes 

 are not poisonous to man. Culicide is a combination of 

 equal parts by weight of carbolic acid crystals and gum 

 camphor. Dissolve the carbolic acid crystals over a 

 moderate heat and pour over the camphor broken into 

 small lumps; the acid dissolves the camphor and the 

 solution is permanent when kept in a stoppered jar. It 

 requires three ounces of this culicide for every 1000 

 cubic feet of space and it should be evaporated in a 

 shallow pan over an alcohol or other lamp. This will 

 kill flies as well as mosquitoes and is not dangerous to 

 human life. The mixture is inflammable, however, and 

 must be used with that fact in mind. 



Whichever of these materials is used, the room to be 

 fumigated must be made as nearly air-tight as possible, 

 and must be kept closed at least an hour to make certain 

 of a satisfactory effect on the insects. 



Fleas are specialized flies, adapted for a particular 

 mode of life, and their habit of more or less indis- 

 criminate biting has laid them open to suspicion in 



