Cornell Nature-Study Leaflets / Being a selection, with revision, from the teachers' leaflets, home nature-study lessons, junior naturalist monthlies and other publications from the College of Agriculture, Cornell University, Ithaca, N.Y., 1896-1904

by New York State College of Agriculture

Fig. 129. Killing bottle.

Materials needed for a killing bottle.

1. A bottle with a wide mouth; a morphine bottle or a small olive or pickle bottle will do. Even a glass fruit-can holding a pint will answer very well, although taking off and putting on the cover consumes more time than is desirable.

2. A cork that will fit the bottle tightly and is long enough to handle easily.

3. Two cents' worth of cyanide of potassium.

4. One cent's worth of plaster of Paris.

These latter materials may be procured from any drug store.

Place the lump of cyanide of potassium in the bottle and pour in enough water to cover it. Add immediately enough plaster of Paris to soak up all the water; leave the bottle open in a shady place for an hour and then wipe the dry plaster of Paris from its sides, put in the cork, and it is ready for use. The plaster of Paris forms a porous cement, which, while it holds the cyanide fast in the bottom, also allows the fumes of the poison to escape and fill the bottle. It should be labelled "poison," for cyanide of potassium is very poisonous. If kept corked when not in use, a killing bottle made like this will last a whole season.

The first rule in using the killing bottle is this: do not kill any more insects than you need for your collection. The second rule is: do not breathe the fumes of the bottle, for they smell badly and are not good for you. When you uncork the bottle to put an insect in it, hold it away from your face and cork it up again as quickly as possible.

Some insects may be caught from flowers, etc., directly into the bottle by holding it uncorked beneath them for a moment; the fumes of the poison soon overcome them and they drop into the bottle. In taking insects from the net, hold the bottle in the right hand and the cork in the left; insert the bottle into the net and place the mouth of it over an insect crawling on the inside of the net, then put the cork on the outside of the net into the mouth of the bottle, net and all, for a moment until the insect falls into the bottom of the bottle; then remove the cork and take the rest of the imprisoned insects in the same way. Insects should be left in the bottle at least an hour, and may be left in there over night without injury to the specimens.