THE CANADIAN ENTOMOLOGIST. 137 



but the study of insects has great attraction for me, and I spend no Httle 

 time upon it. 



The method which I desire to mention may be too well known to 

 deserve any space in your columns — if so, I can only ask you to over- 

 look my intrusion — but I have never seen it mentioned in print anywhere, 

 nor have I ever seen it used by any entomologist of my acquaintance. 

 Perhaps also there may be some objections to its adoption which I have 

 not discovered in the course of several years' use. In that case I shall be 

 glad to learn them. 



Your contributors speak of chloroform and cyanide of potassium as 

 their favorite insecticide materials. Both these I have abandoned for 

 some years, the former because it is expensive, and the latter because i^ 

 is unpleasant and dangerous, especially the latter to young students, and 

 both because they are comparatively imperfect in their effects. For 

 example : I have often known an insect, especially one of the large 

 bodied Bombycids, that recovered after having been apparently killed by 

 chloroform, and even after having been pinned out in the case. The 

 result usually is that it is seriously injured by flapping about. Chloroform 

 is an anaesthetic and not a poison, and its effect soon passes off unless its 

 action is renewed or long continued so as to insure death. 



In regard to cyanide of potassium, I may state that last year I found 

 one of my cases badly infested with the fur moth (T. pellionella). I put 

 an open bottle containing cyanide of potassium into the case and closed 

 it. For a fortnight it remained so, when desiring to know the result of 

 the poison, I opened it. It was strongly impregnated with the well known 

 smell of the cyanide. To my surprise, however, I could not find a dead 

 moth, and the larvae were as lively after breathing for fourteen days the 

 so-called deadly atmosphere as if they had been all the time in the open 

 air. As a substitute for both of these I have for years used no other 

 insecticide for the purpose of killing my specimens than benzine or 

 gasoHne. The latter at fourteen cents a gallon is merely nominal in cost 

 and perfectly efficacious in action. I use it without hesitation on the 

 Lepidoptera in any quantity. With most of them it causes instant death, 

 and with the few that slightly resist its effects the resistance is very short- 

 lived. I recollect one day seeing a large Cecropia moth enter the room 

 where I was sitting and alight on the knob of the door handle. I took 

 my bottle of gasoline and poured some of the liquid on the body of the 



