Fig. 19. Lamp Net.
Fig. 20. Chloroform Bottle.
The best methods of stupefying and killing insects on the field is the cyanide bottle, prepared by placing alternate layers of cyanide of potassium and blotting-paper in the bottom of a wide-mouthed bottle, the mouth of which is accurately stopped with a cover, which is better for the purpose than a bung. The chloroform bottle, which is generally made with a little nipple, through which the fluid flows slowly out, and covered with a screw-tap, as in the cut 20, is also handy. The chloroform should be dropped over perforations in the box containing our patient, these perforations having been previously made by a few stabs of a penknife. After the fluid is dropped, our thumb should cover it, when the vapour will quickly enter, and the inmate speedily become insensible. Afterwards the coup de grâce may be given to the insect by pricking it under the thorax with the nib of a steel pen dipped in a saturated solution of oxalic acid. If we are smokers, a puff of tobacco may be blown into the box with like result. If we are destitute of any apparatus, and brimstone lucifers for the purpose of suffocating our captures under an inverted tumbler cannot be obtained at some roadside inn, we must fall back on the barbarous practice of pinching the thoraces of such as cannot be carried home in boxes. At home we shall find the laurel jar and ammonia bottle the most useful. The former is made by partially filling a large wide-mouthed bottle or jar with cut and bruised dry leaves of young laurel: if any dampness hang about them, we shall have the mortification of seeing our specimens become mildewed. The latter consists in adding a few lumps of carbonate of ammonia, or some drops of strong liquid ammonia, on a sponge, to the bottle in which our captures, with each box lid slightly opened, have been placed. But it must be borne well in mind, firstly, that ammonia is injurious to the colours of most green insects; and secondly, that if the specimens be not well aired after having been thus killed, the pins with which they are transfixed will become brittle and break. Insects should be left in the ammonia for several hours, and are then in the most delightful condition for setting out.
To pin an insect properly is a most important procedure. The moth, if of moderate dimensions may be rested or held between the thumb and fore finger of the left hand, while the corresponding digits of the right hand operate by steadily pushing a pin through the thorax, bringing it out between the hind pair of coxæ until sufficient of the pin is exposed beneath to steady the insect in the cabinet The direction of the pin should be perpendicular when the insect is viewed from the front, as in [Fig. 21]; but a lateral view should show the pin slightly slanting forwards, as in [Fig. 22]. Pins made for the purpose in numerous sizes are sold by Mr. Cooke, of New Oxford Street.
Fig. 21 Front View of properly pinned Insect.
Fig. 22. Side View of ditto.