636 Collecting and Rearing Insects 
mouthed bottle from three to six inches high (a quinine or quassia bottle is 
good) and covering this with wet plaster of Paris. When the plaster sets 
it will hold the cyanide in place, and allow the fumes given off by its gradual 
volatilization to fill the bottle. Or the cyanide may be covered with damp 
sawdust over which is placed a cardboard disk cut so as to fit tightly into 
the bottle. The advantage of the sawdust covering instead of plaster of 
Paris is that it allows one to clean out the bottle after the cyanide is used 
up and to recharge it. The plaster of Paris is broken out of a used-up bottle 
only with difficulty. The disadvantage of the sawdust and cardboard cover 
is that it is likely to be loosened if the bottle is jarred often. Insects dropped 
into a cyanide bottle will be killed in from two to six or seven minutes. Keep 
a little tissue-paper in the bottle to soak up moisture and to prevent the 
specimens from rubbing. Also keep the bottle well corked. Label it 
“poison,” and do not breathe the fumes (hydrocyanic gas). Insects may 
be left in it overnight without injury to them. 
Butterflies or dragon-flies too large to drop into the killing-bottle may 
be killed by dropping a little chloroform or benzine on a piece of cotton, 
to be placed in a tight box with them. Larvae (caterpillars, grubs, etc.) 
and pupae (chrysalids) should be dropped into the vials of alcohol. 
When the collected insects are killed they may be “pinned up” or 
“papered” in the field; or if not many have been taken, may be brought 
home in the killing-bottle and cared for after arriving. 
To “paper” specimens—and only insects with large wings, as butterflies, 
moths, dragon-flies, etc., are papered—they should have the wings folded 
over the back and the specimen then laid on one side on a rectangular piece 
of smooth paper, not too soft, which is then folded so as to form a triangle 
with the margins narrowly folded over to prevent its opening. A very success¬ 
ful professional collector of my acquaintance “papers,” in a sense, small 
insects in the following way: In the bottom of a small tin, wooden, or paste¬ 
board box he puts a thin layer of glazed cotton; over it he lays a sheet of 
paper, and on this a layer of small insects just as they are poured out of the 
cyanide bottle; then a covering sheet of paper, and over this a layer of cotton, 
another sheet of paper, a layer of insects, and so on. In this way he rapidly 
cares for hundreds or thousands of specimens in the field. When these 
specimens are brought home he either pins them up immediately while 
fresh and flexible, or stores them away to be worked over and pinned up 
at leisure. Before dried insects can be pinned, however, they must be re¬ 
laxed. This may be effected by steaming them, or simply by putting them 
for a day or two into a closed glass jar with a soaked sponge. In my lab¬ 
oratory we keep one or two jars with a layer of wet sand in the bottom; 
into these relaxing jars dried insects can be put at any time, and made ready 
for pinning. 
