eight pints are required, according to the depth and extent of their nests.
Although insects are very injurious to vegetation, yet Dr. Darwin is of opinion that they may be rendered extensively useful as a manure. Hence, in the summer months, he recommends heaps of dung to be supplied with water, for promoting the propagation, and nourishment of myriads of vermin; which, when suffered to decay on the soil, would greatly contribute to its fertility.
The catching and preservation of insects, for the collections of naturalists, is indeed a necessary practice, though it has at all times been branded with cruelty. Hence, in stating the most proper methods of effecting this purpose, we shall likewise point out the easiest expedients to deprive them of life.
Beetles, and other insects of the same class, may be caught either with a gauze net, or with a pair of pincers covered with gauze. As soon as they are secured, it will be advisable to immerse them either in hot water, or in spirits of wine, where they will be instantaneously killed: next, they may be fixed to a piece of cork, in a creeping direction, and exposed to the air till all their moisture be evaporated.
Bugs, crickets, and other insects of the hemipterous class, may be put to death in the manner just mentioned, or by pouring a drop of etherial oil of turpentine on their head.
Moths, butterflies, and all other flies which are furnished with membranous wings, may be taken with gauze nets; then pierced through the shoulders between the fore-wings, with a pin; and, after gently squeezing the breast of the insect, it will immediately perish.
Lobsters, scorpions, or such vermin as have no wings, may be preserved in spirits; and the various other kinds of insects may either be killed with oil of turpentine, or the fumes of sulphur.
After the insects are deprived of all moisture, they should be placed in the boxes or cabinets where they are to remain; these should be kept very dry, and closely shut, to prevent the depredations of small vermin. The bottoms ought likewise to be covered with pitch, and paper on the surface; or, they may be preferably lined with cork, which should previously be impregnated with corrosive sublimate, in a strong solution of sal ammoniac.
INSTINCT, denotes that faculty or disposition of mind, by which animals are led spontaneously to perform whatever is necessary to preserve the individual, or to continue the species; independently of any instruction or experience, and aiming at no determinate object.
Thus, infants suck immediately after they are born; thus, too, insects deposit their eggs in all climates, invariably in such situations as are peculiarly favourable for the hatching and support of their future progeny.
In succeeding years, the faculties of the juvenile mind enlarge, and our conduct is, or at least ought to be, dictated by reason; while the actions of the brute creation are generally directed by instinct. With respect, however, to the human instinct, philosophers are by no means agreed; some affirming that man possesses a greater number of instincts than any species of brutes, while others assert that human na-
