Insects to be preserved in a collection should be killed separately in a wide-mouthed stoppered jar, at the bottom of which is cyanide of potassium covered with plaster-of-Paris. As soon as it is quite dead, remove the insect from the bottle, catching hold of it by the middle - that is, where the legs join the body - and use a pair of tweezers, not fingers or anything as clumsy. Suitable tweezers can be bought at many shops, and can be made by bending double a strip of thin sheet steel or brass Jin. or Jin. wide and 6in. or 8in. long till the two ends meet and form a delicate substitute for forefinger and thumb. The spring of the metal at the bend should keep the ends about 3/4 in. or 1 in. apart. The ends can be filed to a blunt point. Touch the insect as little as possible, and always catch hold of it by the thorax. The wings and other parts of butterflies and moths are covered with minute feathers, which are rubbed off and defaced at the slightest touch. The dead insect stiffens and dries up rapidly; therefore, have ready a setting board, on which to hold it in position whilst drying.

The setting board is made by gluing two strips of soft, smooth cork, each 9 in. by 1 in. by 1/2 in., to an under-piece of wood 9in. by 21/4 in. by 1/4in. The two cork strips are glued to the wood with a 1/3-in. groove between then-longest edges, and the cork is slightly bevelled off on the outer edge. Insect setting boards used by Continental naturalists are, however, quite flat; but English naturalists consider insects to be spoilt if set flat. Of course, the larger the insect the wider will the board require to be. In the 1/4-in. groove the body of the insect lies whilst its wings are extended over the cork on each side. Along the bottom of the central groove glue a strip of cork. Having laid the dead insect in the groove, a pin is pushed vertically through the centre of its thorax down into the cork; the height of the latter should be just sufficient to bring the wing above the edge of the side cork, and packing must be inserted where necessary to ensure this. An entomological pin, long and thin with a small head, is used. If the wings can bespread with a couple of sparrows'-tail or flight feathers fixed in a handle, all the better. Contact with fingers or tweezers or such like spoils the wings.

Small slips of letter-writing paper are used as straps to hold the wings in their extended position, a couple or more of ordinary pins being stuck through each strap, but not through the wings. Use plenty of straps to keep the wings extended; put the set insect aside for a week or so, remove the straps, and stick the sample inside a store box or case. Camphor enclosed with the specimens will preserve them from mites, which otherwise might spoil a valuable collection. In the busy insect season many adopt the system of leaving the killed insects to dry unset, so that they may be relaxed and set properly at leisure. Dry insects are easily relaxed by keeping them on damp sand for a few days, when they may be treated on the setting board precisely as if they had but just been killed.