-Camberwell Beauty Butterfly, with card braces, showing the mode in which a Butterfly should be set.

CHAPTER IV.

ALTHOUGH the author is fully satisfied that insects have not the acute sense of pain possessed by ourselves and warm-blooded animals, yet he wishes to impress on the collector of insects, that it is unjustifiable to subject any animal to even the possibility of suffering for our own gratification. Therefore let us resolve to adhere to two rules; first, to destroy no more specimens than are really requisite; secondly, to kill them in the most certain and expeditious manner: under any circumstances, the reflection that we have done this will be agreeable.

Butterflies and moths require to be pinned immediately on being taken; the pin is passed through the very centre

I

of the mesothorax,* or that part to which the wings are attached, the finger and thumb of the left hand, at the same time, pinching the insect under the wings. A slight pinch kills a butterfly, but it is far otherwise with a thick-bodied moth; these seem to possess an excess of vitality. There are several modes by which moths may be killed, but some of these are not at all times convenient; however, it will be best to give them all, and then the reader may avail himself of one or other, according to circumstances. First, take the moth by the wings, held together over its back, and then dip its body suddenly in boiling water; immediately on withdrawing it, it will be found that life and motion are completely extinct; but the downiness of the body will have received an injury which it never effectually recovers. Secondly, fix a piece of thin cork firmly at the bottom of a gallipot; then, having pinned the moth, as before described, through the mesothorax, stick the pin in the cork, and invert the gallipot in a basin of boiling water: the steam produces death almost instantly, and does not injure the plumage of the moth. Thirdly, having pinned the moth, take its body between the finger and thumb of the left hand, then withdraw the pin, and having previously prepared a sharp-pointed piece of quill or wood, dip it in prussic acid or a strong solution of oxalic acid, and introduce it into the aperture made by the pin; death follows almost instantly. A fourth mode of killing moths as well as other insects, has been recorded by Mr. Stephens, in the second volume of the 'Entomological Magazine;' it is as follows:-"take three or four juicy leaves (the younger the better, with, if a more powerful effect is required, a small portion of the tip of the stalk) of the common laurel; break or cut them into

* These anatomical terms will be fully explained in the following book, entitled 'Physiology of Insects.'

small pieces, and crush them quickly between two stones, in a thin piece of paper; screw up the produce in the latter, with as little exposure to the air as can be avoided, and fix the mass by a pin in a corner of the collecting-box, in which the living insects are to be previously placed; keep the box closely shut, and in about five minutes every specimen will have expired. It is necessary that the external air should be excluded, otherwise the fumes of prussic acid which are evolved from the crushed leaves, will become too much attenuated to affect the respiratory organs of the insects, and the latter will partially revive if too speedily exposed to the vivifying influence of a purer atmosphere. I have tried the experiment rather extensively upon insects of various families; Bombi and Helophili die very rapidly, in less than two minutes, and without any struggling, as is the case when heat &c. is applied; and moths, in a state of repose, expire without a single previous motion: consequently the process I have recommended is most admirably adapted for killing the larger Lepidoptera almost immediately upon their capture, and thus fine specimens may be conveyed home uninjured. I yesterday killed a gigantic spider in less than half a minute; and a specimen of Helops cæruleus, with one or two fresh-captured Philonthi, at liberty in the box, were also dead when it was opened. I therefore strongly recommend the above process to the notice of the practical entomologist, as being, from its convenience, better adapted for general application than any hitherto proposed."

Diptera and Hymenoptera are generally best carried home alive in pill-boxes, vials, or quills, as recommended in the previous chapter; the same also with very minute moths: Coleoptera of almost every kind may be safely immersed in the vial of spirits: Orthoptera and Hemiptera, if large, may be pinned; if small, put in pill-boxes: dragon

flies require to be pinned. Diptera and Hymenoptera should, when sufficiently large, be pinned, like the Lepidoptera, through the centre of the mesothorax; Coleoptera, through the right wing-case; Orthoptera, through the prothorax; and Hemiptera, through the mesothorax, generally in this class a triangular plate: dragon-flies should be pinned in the centre between the four wings.

All insects taken home alive in pill-boxes may be killed thus. Open the lids of the boxes a very little way, just so as to admit the passage of air, but not the exit of the insect; then make a pile of the boxes, thus partially opened, on a piece of soft leather placed on a table; invert a pint basin over the boxes; burn one or two matches under the basin. If the basin and boxes are placed close to the edge of the table, the facility of burning a match under the basin is increased. The basin should be pressed down, and the leather precludes the ingress of fresh air and the egress of the sulphur-smoke; if the boxes are examined in a few minutes, the insects will be found perfectly dead. But it must be borne in mind that the fumes of sulphur have different effects on different colours; yellow and red retain their brightness when submitted to it, or even acquire additional lustre, but blues and greens, on the contrary, are frequently totally destroyed.

All kinds of insects are killed instantaneously by immersion in boiling water; and with the exception of Diptera and Lepidoptera, none are materially injured by the process. The minute insects brought home in quills may be readily killed by immersing the quill in hot water, at the same time holding the cork between the finger and thumb. The beetles brought home in spirits should be subjected to this process, first, as a cleansing and purifying operation; secondly, because the spirit appears only to stupify and deprive them of motion, so that without this second killing

they generally revive.

All insects killed in water should

be very carefully spread on blotting paper; those large enough for pinning should be then selected, and left until thoroughly dried; those which are so small as to be injured by a pin should be removed to a sheet of pasteboard; each should be floated on a drop of water, and the water withdrawn by a camels' hair brush. The legs and wings usually spread out neatly of themselves, but if they do not, a little assistance from the brush will accomplish it; the board should then be carefully put away, and the insects will dry in the position in which they were left, but are so slightly attached to the board that a touch of the pencil will remove them.

A number of very small pieces of card should next be prepared; they should be triangular, with one angle very acute; a pin should be passed through each, near the base; then with a fine brush touch the acute point of the card with clean transparent gum-water, and again moistening the brush take up one of the insects and place it on the gum, to which it will instantly adhere. All minute Hymenoptera may be mounted in this way. The wings of minute Diptera are more difficult to deal with, being of a softer texture. As few of these should be mounted as possible, and great care should be exercised in the operation; the rest of the Diptera should be pinned. The minute insects brought home alive in the vial may be instantly killed by immersing the vial in hot water, after which they may be mounted at any future opportunity, when more time can be spared for the operation: each vial should be labelled with the date and place, when and where taken; and thus a winter's amusement may be provided.

In setting, i. e. arranging the legs and wings of those insects sufficiently large to require pinning, there are two modes: the first is to place the wings horizontally, the se