66 Circular No. 15. 



be used with safety in almost any part of a dwelling. Turpen- 

 tine soon evaporates and must be renewed. Its odor, also, is 

 objectionable to many people; of the three, perhaps oil of cit- 

 ron ella is to be preferred. A very effective tape can be made 

 by soaking cloth, or tape, in a solution of corrosive sublimate, 

 as follows: Dissolve by boiling in a porcelain dish or glass 

 beaker a small quantity of corrosive sublimate in four or five 

 ounces of water. When cool, filter thru good filter paper, 

 then soak the tape for four hours and finally suspend it in loops 

 from a cord stretched across the room until dry. It has no 

 perceptible odor, and strips tied about objects will last for 

 months. The fluid and cloth are poisonous, so must be handled 

 at all times with caution, the tape to be finally burned. The sub- 

 stance is corrosive to metals also, and must not be brought in 

 contact with them for any length of time. Scissors used to cut 

 the tape should be washed carefully, as should the hands. 



Sometimes one, sometimes another of these precautions be- 

 comes practicable, according to circumstances. And again sev- 

 eral may be employed to advantage at the same time. But it 

 should always be remembered that the complete suppression of 

 these pests can be most quickly accomplished by finding and 

 destroying the nests, whether indoors or out 



HOUSE-FLIES. 



The only fly very troublesome about dwellings and calcu- 

 lated to do us serious harm is the common Musca domestica, a 

 species that appears to have followed man in his peregrinations 

 about the globe and in spite of his hostility to have persistently 

 held its own as an occupant of his habitations. 



The house-fly passes the early stages of its existence in 

 manure and other decaying vegetable substances. The eggs are 

 placed there by the adults and produce maggots in a few days. 

 These feed on the refuse and soon become enclosed in a firm, 

 brown coat in which they assume the quiescent pupa stage, after 

 which they come forth as adults. The whole life-story of a fly may 

 be completed in eight days, during very warm weather, but varies 

 with the temperature. The winter is passed in the adult, or 



