Minute moths are to be found in winter as well as summer. It would be scarcely credible, did not experience prove, that when the frost is so intense, as to entirely subvert the appearance and almost annihilate the existence of vegetable productions, within its influence myriads of these delicately-formed creatures brave the inclement season, and exist securely within those habitations which they have the address to construct. A skilful entomologist may at this season in a few hours collect a number of the coleoptera, hemiptera, and lepidoptera orders; several of which are not to be obtained, but in very cold weather.
These insects usually shelter themselves among the moss and other extraneous matters growing on the trunks or branches of trees, or beneath the rotten bark; these substances should be shut close in a box or tin canister, to prevent the escape of those insects that may be revived by the warmth. To examine them, Donovan recommends spreading a sheet of writing paper on a table, and placing a lamp or candle, with a shade of transparent or oiled paper before you, so as to weaken the glare; separate the moss, and shake it loosely in your hand, and you will perceive many insects fall down on the paper. If they be too minute to admit of a pin being thrust through the thorax, they may be fastened with gum-water to small slips of paper.
GENERAL INSTRUCTIONS FOR FITTING UP A CABINET.
To those who delight in subjects of natural history, a good cabinet of insects is esteemed a valuable acquisition: if it be well constructed, and the several objects arranged with judgment, it certainly exhibits one of the most beautiful and admirable assemblages of objects in nature. Such, however, who are disposed to make a collection sufficiently extensive to form a complete one, will find it necessary to devote a great deal of time to the purpose, as well as to be endued with a considerable share of perseverance and ingenuity; those who are possessed of affluence will find it far less difficult to acquire one. The cabinet, to appear with that elegance which the subject deserves, should be of mahogany, well seasoned, and made by a good workman in such a manner that all the joints may fit with the greatest nicety; the form and size may be according to fancy, or the extent of the collection intended to be made.
To form a cabinet sufficiently capacious to receive specimens of all the English insects hitherto discovered, those excepted which, as before observed, are better preserved in spirits or between sliders, I would recommend one on the following plan:
The height may be about three feet four inches, the width two feet four inches, and the depth one foot four inches, inclosed with folding doors, and provided with a good lock. The inside to be partitioned down the middle, so as to admit of a range of twelve square drawers on each side; under these, two or three drawers may be fitted extending the whole width, to admit the larger kinds of insects, such as the sphinges, cancri, &c. the sides and backs of all these drawers should be of cedar, and the fronts mahogany, with a brass ring or button to each. The cork with which their bottoms are lined, must be chosen as free from cracks as possible, and, after being washed several times with a solution of corrosive sublimate in spirit of wine, to destroy the animalcula, glued on to prevent its warping. The whole surface must be made perfectly smooth and level, and this, as well as the sides, covered with imperial paper carefully pasted on, and afterwards moistened with alum-water. The paper should be exactly ruled into squares proportioned to the size of the insects they are intended to contain; and the names of each order and genus affixed according to the system of Linnæus. By way of embellishment, the edges may be lined all round the drawers with narrow slips of some kind of ornamental paper. The fore-part of each drawer should have a thin partition to admit of a proper quantity of camphor, with a number of small air-holes for the more ready diffusion of its effluvia to the insects contained in the drawer: the tops of these partitions must be closed with thin slips of wood laid on them and fitted with nicety, but not glued. To prevent the admission of dust and air, and exhibit the contents to advantage, the top of each drawer must be glazed with the finest glass, fitted into a frame of the same size as the drawer, made either to slide in a groove, or let in on a rabbet.
Having proceeded thus far, it will be adviseable to let the cabinet be thoroughly aired, before any insects are deposited in it, and to be particularly careful that all the insects so deposited be as free as possible from moisture; if the cabinet be then constantly kept in a dry situation, the camphor occasionally renewed, and the air excluded, there is every reason to expect that the several insects may be for a long time preserved in a state of perfection. If, notwithstanding all these precautions, little dusty particles should appear on any of the insects, which is a certain sign of the presence of animalcula, they should be gently wiped with a hair pencil dipped in spirit of wine, or carefully removed into a chip box and placed on the side of a Bath stove for a short time; by these means, if early attended to, they will be sufficiently baked to prevent future injury. A strict adherence to the above particulars, enabled me to preserve the contents of the cabinet formerly in my possession, now the property of Sir John St. Aubyn, Bart. F. R. & L. S. for several years in the most perfect condition, though containing considerably above 2000 articles. Within the same space of time, to my certain knowledge, several valuable collections have been either totally destroyed, or very materially injured; as when once the depredations commence, the destruction proceeds with rapidity, if not speedily prevented.
Those who are desirous of enriching their collection with the productions of other climes, will require a cabinet much more extensive, or, as the subject may be said to be inexhaustible, may devote several to exotic insects only. The collection made by Mr. Drury being, I believe, the most superb which has ever appeared in this kingdom, it may prove agreeable to many of my readers to give them a concise account of it. It is contained in five large cabinets, and consists of two divisions; first, those found in this country, and, secondly, those procured from various quarters of the globe. The English collection contains 2324 different insects, and the foreign one 5066; total, 7380: the latter comprises of coleoptera, 1716; hemiptera, 676; lepidoptera, 1739; neuroptera, 122; hymenoptera, 472; diptera, 312; aptera, 29. The whole of this magnificent collection is regularly arranged, according to the Linnean system, in 144 drawers. Some of the most beautiful objects in this collection are exhibited and fully described in a work published by Mr. Drury, in three vols. quarto, containing on 150 plates about 700 elegantly coloured specimens.
The climate of Asia is particularly favourable to the production of numerous articles in the several branches of natural history unknown to, or not natives of Europe; especially those of the lepidoptera order of insects, numbers of which are remarkably large, and exhibit a variety of the most beautiful colours. This induces gentlemen, previous to their departure for India, to furnish themselves with cabinets at a considerable expense, anticipating the satisfaction they shall enjoy during their residence there, in arranging and depositing therein the several articles they purpose collecting, and entertaining their friends with a view of them. Besides this, they receive commissions from their European friends to collect and remit to them as many as they can, neither party conceiving that this would be attended with any considerable degree of trouble or inconvenience. It may, therefore, not be amiss to introduce here what the Rev. Mr. John, one of the Danish missionaries at Tranquebar, says on the subject.[168] “The rainy season is in the highest degree injurious to collections in every part of natural history, shells and minerals excepted. To obtain a permanent cabinet, if not impossible, is at least very difficult and expensive. Insects, unless carefully preserved in close cases, well secured from the accession of the smallest particle of air, are soon covered with mouldiness; nor are dried fish, stuffed birds, skins of animals, plants, &c. exempted from this inconvenience; if not frequently exposed to the rays of the sun or dried in ovens, myriads of animalcula in a short time form a settlement and inevitably destroy them. All the cabinets received from Europe, lined in the accustomed manner with cork or deal, are here on this account totally useless, besides their being soon disjointed by the heat of the climate. Sail cloth, well pitched and extended on frames, is far better calculated to answer the purpose; a number of these may be placed one above another, at a convenient distance, and the whole supported on light feet: to render them more pleasant to the eye, the linen may be covered as most agreeable either with white or coloured paper. Even the echini, and the smaller marine plants, attract so much dampness as to lose their colours and spiculæ, and fall to pieces, especially if they have not for some time been previously soaked in fresh water, in order to deprive them of their saline particles. Stuffed birds, &c. lose their feathers or hair, and the more soft and tender parts fall off. Consequently, if no ships go from hence during the month of October, but are detained till February, the major part of what I have collected for such of my friends in Europe who are admirers of the wonderful works of the Creator, will be lost to myself and them, besides subjecting me to the imputation of a want of attention and gratitude for favours previously received, than which nothing can be farther from my heart.”
[168] Neuere Geschichte der Missions Anstalten. 48 stück. Halle 1796.