Chapter XVII: Brachionus (5)

This order contains various kinds of flies and gnats; the former abound in almost every place, but they are found more particularly on all kinds of plants and flowers, especially on the umbelliferous ones, about the tops of trees, little hills, &c. Some of them fly about cattle of various kind, in the skins of which they deposit their eggs, as the oestrus bovis, &c. These insects are easily killed by a few drops of spirit of turpentine: their wings are to be expanded so that their bodies may become apparent; a little brace should be placed underneath them, to prevent their bodies being too much incurvated in drying, which they are very apt to be. Many of these are most easily taken when they begin to feed; for, in the middle of the day they are so quick and active, that it is almost impossible to catch them.

With regard to the last order of insects, distinguished by the term APTERA, they are so common, and the places they inhabit so generally known, that any information on the means of collecting them must be superfluous. Under this class are included spiders, scorpions, centipes, crabs, lobsters, &c. &c. Most of these require to be preserved in some kind of spirit; spirit of wine, proof spirit, or geneva, are to be preferred, on account of their pellucidness; though rum or brandy may, if no other spirit be at hand, answer the purpose of preserving, though not that of exhibiting them with equal advantage.

Those of the genus cancer, after being well dried or carefully baked, may be conveniently preserved in store boxes, or properly arranged in a cabinet collection. The smaller kinds of insects in general, as well as those of the order aptera, are best disposed of between talcs in sliders; such, for instance, as the termes pulsatorium,[167] the several poduræ, pediculi, pulices, acari, &c.

[167] According to Linnæus, this is the minute insect which has been
long known by the English name of the death-watch, and described by a
number of authors: Linnæus thus notices it; “frequens in domibus,
invisum vestibus, herbariis, insectorum museis. Fœmina horologii
instar pulsatoria in ligneis festucis.” Syst. Nat. p. 1015. No. 2.
Geoffroy, however, says he is confident that it is not from this
insect, but from the dermestes domesticus, (Syst. Nat. p. 563, No.
12,) which makes the circular holes in furniture, that the ticking
noise proceeds. Hist. des Insectes, Tom. I. p. 111. & Tom. II. p. 602.
Neither of these are larger than the pediculus humanus. Again, on the
respectable authority of Dr. Shaw, we are assured, that the insect
properly called the death-watch is a coleopterous insect of the genus
ptinus, Syst. Nat. p. 565. The Doctor says, “it is chiefly in the
advanced state of the spring that this alarming little insect
commences its sound--the prevailing number of distinct strokes is from
seven to nine or eleven--these are given in pretty quick succession,
and are repeated at uncertain intervals; and in old houses, where the
insects are numerous, may be heard almost every hour of the day,
especially if the weather be warm. The sound exactly resembles that
which may be made by beating moderately hard with the nail on a
table--It is about a quarter of an inch in length.” This very able
naturalist has distinguished the insect by the name of ptinus
fatidicus, the beating ptinus, and supposes it to be the same with the
dermestes tesselatus of Fabricius, and the ptinus pulsator of Gmelin.
He also cautions us “not to confound this insect, which is the real
death-watch of the vulgar, emphatically so called, with another
insect, which makes a sound like the ticking of a watch, and which
continues its sound for a long time without intermission: it belongs
to a totally different tribe from the death-watch, and is the termes
pulsatorium of Linnaeus.” Every one will agree with the Doctor in his
remark, that, “it is a very singular circumstance that an animal so
common should not be more universally known.” Nat. Misc. vol. iii.

Whichsoever of the three above described is the real insect, it is
well known, that for a series of years the dread of it has excited the
most uneasy sensations in the minds of the weak and superstitious; an
unhappy prejudice which exists even to the present hour, and cannot be
totally eradicated by all the powers of reason and argument. Sir
Thomas Brown long since observed, “He that could extinguish the
terrifying apprehensions hereof, might prevent the passions of the
heart, and many cold sweats in grandmothers and nurses.” Pseudodoxia
Epidemica, Book ii. Chap. 7. With the feelings of these persons a
well-known satirist sports in the following lines:

--------------“a wood worm
That lies in old wood, like a hare in her form:
With teeth or with claws it will bite or will scratch,
And chambermaids christen this worm a DEATH-WATCH:
Because like a watch, it always cries click,
Then woe be to those in the house who are sick;
For sure as a gun, they will give up the ghost,
If the maggot cries click, when it scratches the post.”

Swift’s Invective against Wood.

Another poet has also diverted himself with the same subject:

--------------“The weather’s bell
Before the drooping flock told forth her knell.
The solemn DEATH-WATCH click’d the hour she died.”

Gay’s Pastoral Dirge.

It is remarkable, that though the ignorant despise the minuter parts
of creation, as too insignificant to engage their notice, and venture
to deride those better informed for their attention to such TRIFLING
subjects; yet are those the very persons on whom REAL TRIFLES make the
strongest impressions, and by whose credulity an apparently
insignificant creature has been MAGNIFIED, so as to become an object
of considerable importance in the scale of beings; for, as our great
dramatist says of the JEALOUS:

------------“Trifles light as air
Are to the TIMID confirmations strong
As proofs of holy writ.”

As the collector will have frequent occasion for the use of cork, both to line his boxes with, and to set his insects on, the following directions how to prepare it for these purposes will be found useful.

He may procure the cork in large pieces at any of the cork-cutters; these must be cut into smaller ones, and, in order to make the cork flat, it is to be held before the fire till the heat thoroughly penetrate it; the cork is then to be immediately placed betwixt two smooth boards, and a very heavy weight laid on it; in which situation it must remain till cold. Thus flattened, it is to be rasped on both sides, with such a rasp as is used by the bakers; afterwards, with a finer one; and, lastly, with a pumice-stone; by which it will be rendered perfectly smooth. If the cork be thick, and the purpose of it to line boxes, it may be sawed through the middle, and rasped as before directed.

As, without a due attention to the state of the atmosphere, the collector may make many fruitless excursions, it will be proper to point out to him the kind of weather best adapted for the purpose of ensuring success.

If the day prove fine, and the sun emit much warmth, insects are very brisk and lively; if, on the contrary, the weather should be cold or windy, it will be in vain to attempt catching them on the wing, as at such times insects in general take shelter within the herbage, and instead of flying upwards, which is usually the case when disturbed, they dart into the thickest underwood; or should they rise above the bushes, they are impetuously hurled by the current of the wind far beyond the reach of the net; and, were it otherwise, the collector would find the apparatus unmanageable. Harris says the garden white is as good a token for fine weather as may be; when these flies are out in the morning, it generally prognosticates a fine day.

At day-break many insects are on the wing; and most kinds are observed in hot weather to come forth after rain, to enjoy the humidity of the air; this is the best time for collecting, as their wings are less subject to stiffen before they can be set.

The males of some, if not of every species of moths, and possibly of other insects, by a faculty to us incomprehensible, are able to discover the females, not only at a great distance, but in the most recluse situations. This circumstance has induced some collectors to endeavour to entrap such of the males as are not easily procured by any of the common methods: they enclose the female in a breeding box, and place it as near the usual haunts of the species as convenient; the males will generally be observed soon after fluttering on the box, and endeavouring to gain admission to the females. This artifice has been repeatedly practised with success on the fox and egger moths.

Every species has its distinct time for appearance, which is seldom accelerated or retarded a few days, unless by the unusual mildness or inclemency of the season. If a brood of insects be discovered at a certain season of the year, a brood of the same species will be found precisely at, or near the same period of the year following, except by accident they should have been destroyed. Notwithstanding the observation holds good in general, it is a fact that some insects are very variable in this respect; for instance, the sphinx convolvuli, unicorn hawk-moth, and the papilio hyale, clouded-yellow butterfly, were common about London in the year 1781, but have been very scarce since that time, especially the former; the papilio cardui, painted lady, sometimes disappears for several years. The papilio antiopa, grand surprize or Camberwell beauty, was first discovered in the year 1748, in Cold-arbour lane, Camberwell, and has occasionally disappeared for some years; a few seasons since several were taken in different parts of the kingdom; subsequent to which period, it is not known that even one specimen has been seen. It has been repeatedly ascertained, that, as with plants, so it is with insects, some kinds are confined to one particular spot of ground, and are not to be found in any other part of the same wood; consequently, the haunts being once discovered, the collector may be encouraged to expect meeting with some of the same species for several seasons successively.

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.

The above remarks, it is hoped, will afford some useful hints to gentlemen intending to visit India; as well as plead in justification of those who, unacquainted with the difficulty of preserving collections in so warm a climate, have previous to their departure precipitately made promises to their friends, which for want of being realized, have too frequently exposed them to unmerited censure.

A
COPIOUS LIST
OF
MICROSCOPIC OBJECTS.

In the introductory part to our author’s list of objects in Chap. X. he very justly observes, that from the nature of the subject the list must be very imperfect, &c. it is not with the vain idea of rendering that complete which he has left imperfect, and which indeed must ever remain so, that the following general list is introduced; but principally with the view of still farther assisting the tyro, and pointing out a variety of articles, that might not otherwise so readily occur to him. In most instances, I have mentioned where the objects may be sought for with a probability of success; to have described them would have exceeded my limits. The specimen here given, will convince the reader, that it would be no very difficult task, so to enlarge this list, as to constitute a volume; but, it is presumed, that in its present state it will be found sufficiently extensive, and of considerable utility. To those who are already conversant with the subject, it may prove acceptable as a kind of index to assist their memories; and to such as may be disposed to form a cabinet, it will serve the purposes of directing them in their choice of the principal objects, and exhibiting some idea of the manner in which they are to be arranged.