38 THE BUTTERFLIES OF THE 



three-fourths of an inch in diameter, and should taper a 

 little at one end so as to fit into the socket of the hoop. 

 A net made in this way is light enough to be used easily 

 by even a child without straining the wrist, and yet is 

 strong enough for all ordinary purposes. If it is desirable 

 to put the net in a valise or trunk when one is travelling, 

 the handle may be made in two pieces by sawing it in 

 two in the middle, having a close-fitting tin or brass 

 ferrule made to hold it together when in use. 



Chloroform has been used to some extent for killing 

 insects, but what is called a "poison-bottle" is pref- 

 erable to this, on account both of expense and of ease 

 in use. This is made by placing in a large-mouthed 

 bottle several pieces of cyanide of potassium, the amount 

 depending upon the size of the bottle. If the bottle 

 is large and the glass thin, it is better to break the cyan- 

 ide into pieces not larger than a pea, as otherwise the 

 bottle may be broken by expansion of the poison-cake. 

 After the chemical is in the bottle, pour in water to the 

 depth of half an inch or less, and slowly sprinkle in 

 plaster of Paris till a hard, dry cake is formed, having 

 some loose plaster on top of the cake. Upon turning the 

 side and rolling it round, this will absorb any moisture 

 on the inside of the bottle. Wipe down the sides now 

 with a cloth, using a stick if necessary, pour out the 

 dry plaster, wipe again both inside and out, put in the 

 cork, and the bottle is ready for use. Quinine-bottles 

 are a very good size for small insects. The glass jars 

 with tin tops in which " Old Reliable" baking-powder 

 is put up make excellent bottles for general use. It is 

 better to have several poison-bottles, so that one may be 

 had for use at any time without disturbing those that 



