COLLECTION OF INSECTS FOR STUDY. 



their internal organs without tlieir exhibiting any sign of pain; 

 so there is no need to feel that we are harming hel})less creatures by 

 collecting insects. Still, for the sake of the effect on the collector, 

 it is not well to gather nor destroy more than is necessary for this 

 purpose. 



Insects may be killed by a vapor of chloroform, ether, sulphur 

 smoke, etc., but by far 

 the best way is by the 

 vapor of potassium 

 c y a n i d . This potas- 

 sium cyanid is a hard 

 white substance which 

 can be purchased at 

 drug stores. It is a 

 deadly poison. The 

 cyanid may be broken 

 into small lumps, put 

 in a bottle, covered with 

 a little dry plaster of 

 Paris, and then with a layer of plaster of Paris mixed with water 

 so as to cover the cyanid about one-quarter of an inch. The 

 bottle should be left open an hour or so to diy, and then kept 



Fig. 4.— Method of piimmg butterflies. 



Fig. 5. — Method of pinning bees. 



tightly corked so that the fumes of the cyanid will be strong enough 

 to kill an insect in a few moments (fig. 3). A label with the word 

 "Poison " should be pasted upon it. It is well to place some crumpled 

 strips of soft paper in the bottle to absorb any moisture and to pre- 

 vent the insects from shaking against each other. A weU-made 

 poison bottle will last several yeare. The bottle should be of thick 



