A TREATISE ON THE MANAGEMENT OF INSECTS.
[]A TREATISE ON THE MANAGEMENT OF INSECTS.
[]INSECTS are diſtinguiſhed from other Animals by the wonder⯑ful changes that all, except thoſe of the ſeventh claſs (aptera*), paſs through.
Antient writers were not acquainted with the transformations of Infects, as appears very plainly by the erroneous ſuppoſitions gene⯑rally entertained; neither was the myſtery entirely explained till the latter end of the laſt century, when Malpighi and Swammerdam made obſervations and experiments on Infects, under every appear⯑ance, and by diſſecting them juſt preceding their changes, were en⯑abled to prove, that the Moth and Butterfly grow and ſtrengthen themſelves, and that their members are formed and unfolded, under the figure of the Infect we call Caterpillar.
[14]The ſucceſſion of its transformations are, the Larva or Cater⯑pillar is hatched from the egg.
From the larva it paſſes into the Pupa, or Chryſalis ſtate.
From the Pupa or Chryſalis, into the Imago or Fly ſtate.
THE EGG.
[15]THE eggs of an Inſect are always ſmall, compared with the ſize of the Inſect itſelf; they vary in number and figure in different ſpecies; ſome are round, others oval; ſome are cylindrical, and others nearly ſquare; the ſhells of ſome are hard and ſmooth, while others are ſoft and flexible. It is a rule, but is not invariable, that the eggs never encreaſe in ſize after they are laid.
They are found of almoſt every ſhade of colour, and are always diſpoſed in thoſe ſituations where the young brood may find a convenient ſupply of proper food; ſome Inſects depoſit their eggs in the oak-leaf, producing there the red gall; others cauſe a ſimilar appearance on the poplar-leaf, and the red protuberances on the willow-leaf, and the termination of the juniper branches are pro⯑duced by like means: the leaves of ſome plants are drawn into a globular head by the eggs of an Inſect lodged therein; and many curious circumſtances relative to this oeconomy might be noticed if the nature of our plan would permit.
The Phryganea, Libellula, Gnat, Ephemera, &c. hover all day over the water to depoſit their eggs, which are hatched in the water, and remain there all the time they are in the larva form. Many Moths cover their eggs with a thick bed of hair which they gather from their bodies, and others cover them with a glutinous compoſi⯑tion, which, when dry, protects them from moiſture, rain, and cold; and the Wolf-Spider carefully preſerves its eggs in a ſilk bag, which it carries on its back: by ſome Moths they are glued with great ſymmetry round the ſmaller branches of trees, or are ſecreted beneath the bark, and frequently in the crevices of walls, in hollow ſtalks, &c.
THE CATERPILLAR.
[16]ALL Caterpillars are hatched from the egg, and when they firſt proceed from it are ſmall and feeble, but their ſtrength increaſes in proportion with their ſize; a diſtinguiſhing character of the Cater⯑pillar of a Lepidopterous Inſect is not having leſs than eight, or more than ſixteen feet.
The Caterpillar, whoſe life is one continued ſucceſſion of changes, moults its ſkin ſeveral times before it attains its full growth; thoſe changes are the more ſingular as it is not ſimply the ſkin which is caſt off; but with the exuviae we find the ſkull, the jaws, and all the exterior parts, both ſcaly and membranaceous, which com⯑poſe the lips, antennae, palpi, and even thoſe cruſtaceous pieces within the head, which ſerve as a fixed baſis to a number of muſcles, &c.
The new organs are under the old ones, as in a ſheath, ſo that the Caterpillar effects its change by withdrawing from the old ſkin when it finds it inadequate to its bulk.
Thoſe Caterpillars who live in ſociety, and have a neſt, retire there to caſt their exuviae; fixing the hooks of their feet firmly in the web during the operation. Some of the ſolitary ſpecies ſpin at this time a ſlender web, to which they affix themſelves. A day or two before the critical moment for its moulting, the Inſect ceaſes to eat, and loſes its uſual activity, the colours gradually become weaker and the Caterpillar more feeble, the ſkin hardens and withers, the [17]creature lifts up its back, ſtretches itſelf to the utmoſt extent, ſome⯑times elevates its head, moving it a little from one ſide to another, and ſuddenly letting it fall again; near the change, the ſecond and third rings are ſeen to ſwell conſiderably; and by repeated exertions a ſlit is made on the back, generally beginning on the ſecond or third ring: through this diviſion the new ſkin may be juſt perceived by the brightneſs of its colours; the creature preſſes through like a wedge, and thereby ſeparates the ſkin from the firſt to the fourth ring, which ſufficiently enlarges the aperture to admit the Cater⯑pillar through.
The Caterpillar commonly faſts a whole day each time after re⯑peating this operation: ſome Caterpillars in changing their ſkins, from ſmooth, become covered with hair; while others, that were covered with hair, have their laſt ſkins ſmooth.
The food of Caterpillars is chiefly or entirely of the vegetable kind. The larvae* of Beetles live under the ſurface of the earth, and prey upon ſmaller Inſects, on the roots and tender fibrils of plants, or on filthy matter in general; indeed in the laſt ſtate beetles are moſt commonly found in putrid fleſh, or in the excrements of animals.
When the Caterpillar has attained its full ſize, and all the parts of the future Moth, or Butterfly, are ſufficiently formed beneath the ſkin, it prepares to change into the chryſalis or pupa ſtate; ſome ſpin webs, or cones, in which they encloſe themſelves; others de⯑ſcend into the earth and conceal themſelves in little cells which they form in the light looſe mould; ſome are ſuſpended by a girdle which [18]paſſes round the body, and is faſtened to the ſmall twigs of trees; and Caterpillars of Butterflies connect themſelves by their poſterior extremity to the ſtalks or leaves of plants with their head down⯑wards.
The length of time Inſects live in the ſtate of Caterpillars is al⯑ways the ſame in each individual ſpecies, yet very few ſpecies pre⯑ciſely agree to the ſame period for their changes; ſome live two or three years, others only a few months, or even weeks, before they paſs to the pupa or chryſalis ſtate.
Preparatory to the change, the Caterpillar ceaſes to take any of its food, empties itſelf of all the excrementitious matter that is con⯑tained in the inteſtines, voiding at the ſame time the membrane which ſerved as a lining to theſe, and the ſtomach; and perſeveres in a ſtate of inactivity for ſeveral days. At length, by a proceſs ſimilar to its former moulting, the outer ſkin, or ſlough, is caſt off, and the creature thus diveſted of its laſt ſkin is what we call the Chryſalis.
PUPA, CHRYSALIS, OR AURELIA.
[19]THE words Aurelia or Chryſalis are equally uſed to expreſs that inactive ſtate which enſues after the Caterpillar has changed, for the great purpoſe of preparing for the Imago, or transformation to the Fly. Aurelia, is derived from the Latin aurum, and Chryſalis from the Greek, and are both intended to ſignify a creature formed of gold; this however is giving a general title, from a very partial circumſtance, as the colour of a conſiderable number are black, or dark brown, while the reſplendence of gold is only ſeen on the Chryſalides of a few ſpecies of the Papilio, or Butterfly. The term Chryſalis ſhould therefore be uſed to ſignify only thoſe of the Butter⯑fly kind, and Pupa for the Phalaenae, or Moths, as well as thoſe of Sphinxes, or Hawk Moths.
That very intelligent naturaliſt M. de Reaumur explains the cauſe of this brilliant appearance; it proceeds from two ſkins, the upper one a beautiful brown, which covers a highly-poliſhed ſmooth white ſkin: the light reflected from the laſt, in paſſing through the upper⯑moſt, communicates this bright golden yellow, in the ſame manner as this colour is often given to leather, ſo that the whole appears gilded, although no gold enters into that tincture.
The exterior part of the Pupa is at firſt exceedingly tender, ſoft, and partly tranſparent, being covered with a thick viſcous ſluid, but which drying forms a new covering for the animal.
The time each Inſect remains in this ſtate is very eaſily aſcertained by thoſe who once breed them, as they always remain the ſame ſpace [18] [...] [19] [...] [20]of time, unleſs forwarded or retarded by heat or cold, but in diffe⯑rent ſpecies they vary conſiderably; for example, the Papilio Atalanta (Red Admirable) remained only twenty-one days in Chryſalis, from the 12th of July to the 3d of Auguſt, but the Phaloena Oo. (Heart Moth) remained from the beginning of October till May following; and many ſpecies remain a very conſiderable time longer than this.
When the Inſect has acquired a ſuitable degree of ſolidity and ſtrength, it endeavours to free itſelf from the caſe in which it is confined; and as it adheres to a very few parts of the body it does not require any great exertion to ſplit the membrane which covers it; a ſmall degree of motion, or a little inflation of the body is ſufficient for the purpoſe; theſe motions reiterated a few times, enlarge the opening and afford more convenience for the Inſect's eſcape; this opening is always formed a little above the trunk be⯑tween the wings, and a ſmall piece which covers the head. Thoſe ſpecies which ſpin a cone, gnaw or pierce an aperture large enough for their emancipation.
The Moth immediately after emerging from its caſe is moiſt, with the wings very ſmall, thick, and crumpled; but they rapidly expand under the eye of the obſerver, and in a few minutes have attained their full ſize; the moiſture evaporates, the ſpots on the wings, which at firſt appeared confuſed, become diſtinct, and the fibres, which were before flexible, become ſtiff and hard as bones.
When the wings are unfolded, the antennae in motion, the tongue coiled up, the Moth fuſſiciently dried, and its different members ſtrengthened, it is prepared for flight. The excrementitious diſ⯑charge which is voided by moſt Inſects at this time M. de Reaumur thinks is the laſt they eject during their lives.
INSTRUCTIONS FOR COLLECTING INSECTS.
[21]INSECTS are collected in every ſtate, though in the Caterpillar, or Chryſalis, they are preferred, not only as the time of their ap⯑pearance in the winged ſtate may be then carefully attended to, but they will not be ſo liable to disfigure and damage their tender mark⯑ings, as thoſe which have been in the wind or rain; and if they are taken with care from the breeding-cage immediately after their wings have attained a proper ſize, they may be preſerved free from any injury to thoſe beautiful feathers, which are generally much diſcom⯑poſed in ſuch Inſects as are taken in flight.
There are ſome which cannot be found in the Caterpillar ſtate; or if found, cannot be provided with food; thoſe are generally of that kind which collectors term internal, or underground feeders, and either ſubſiſt on ſome ſubſtance unknown to us, or which we cannot raadily ſupply. The larvae of Beetles and many other kinds of Inſects, are of this deſcription: numbers of the Moth tribe have hitherto only been taken in the Fly ſtate, and are ſuppoſed to feed [22]in the night; they live in cells which they form in the earth, and come up in the evening to feed, but deſcend again into their cells before day-break; it is therefore that ſome Aurelians have ſought for Caterpillars by the light of a candle or lanthorn, and have been very ſucceſsful: the moſt valuable inſects have been diſcovered by this means.
Inſects are found in almoſt every ſituation, the ſummits of the loftieſt trees, and the loweſt herbage equally abound, and the gra⯑dations between ſwarm with an infinity of ſpecies: the collector muſt be therefore ſupplied with a different apparatus, according to the ſtate in which the Inſects may be found; thoſe in preſent uſe, though few and ſimple, require very little improvement, as they anſwer every neceſſary purpoſe. We ſhall enumerate the following articles, which are indiſpenſibly uſeful to the collector,
- A large Bat-fowling-net,
- A pair of forceps,
- A number of corked boxes of various ſizes,
- Ditto ſmall pill boxes.
- A ſpare box with c [...]ps, and
- A pincuſhion well ſtored with pins of different ſizes.
PLATE II. FIG. 1. repreſents the Bat-fowling-net, fitted for uſe.
FIG. 2.
ſhews the frame, which is made entirely of cane, or of light wood, with a cane bow at the top; it ſhould unſkrew, or disjoint at a, a, a, for the convenience of being conveyed in the pocket.
Note, This frame ſhould not be leſs than four or five feet in length, when fitted together.
[23]The net is to be made of Scotch gauſe, not very fine, and bound entirely round with a broad welt, doubled to form a groove into which the ſticks are to ſlip:—this bordering may be excepted at d d, but the gauſe at bottom muſt be turned up about ſix inches and form a bag; each ſtick or frame when the pieces are fitted together, is to paſs into the groove at b b, ſlip up to c, and be there faſtened by a piece of tape through a loop or hole; let the whole be drawn tight and each ſide at b b be tied to the nails; the handles are to be held one in each hand, when the net is uſed.
With this net it is intended to catch Moths on the wing, and that purpoſe it anſwers very effectually, as it may be inſtantly opened or folded together, and ſecure the Inſect between; even Inſects of the ſmalleſt kinds cannot eſcape, if the net is not damaged and the gauſe fine.
It alſo anſwers well for collecting Caterpillars.—Expand the net immediately under the buſh, or branch you mean to examine, another perſon may beat or ſhake the buſh with a ſtout ſtick, and not only a number of Caterpillars will fall down, but many of the minuter kinds of coleopterous, and other Inſects alſo; Moths re⯑main torpid and ſhelter in the buſhes in the day time, and by beating are ery often taken, as they cannot readily fly away when they fall into the net.
PLATE 1. FIG. 3 and FIG. 4.
The forceps are about ten or twelve inches in length, are made of ſteel, and may be purchaſed at the hardware ſhops; their fans are made either of a triangular or hexangular form, and are covered with fine gauſe; they are held and moved as a pair of ſciſſars, and where they can be conveniently uſed are to be preſerred, as the [24]Inſect is more confined, and not ſo liable to rub off its down as when taken in a larger net. If an Inſect is on a leaf, both leaf and Inſect may be encloſed in the forceps; or if it be lodged againſt the trunk of a tree, paling, or any flat ſurface, you may very conve⯑niently entrap it; when you have it between the gauſe, preſs with your thumb, (or thumb nail if the creature be ſmall) on the thorax, rather ſmartly, but not ſo as to cruſh it; you may then ſhake it into your hand to ſet it, without any apprehenſion of its flying away: or you may put the pin through the thorax while the Inſect is confined between the gauſe, open the forceps and take it carefully out by the pin.
CATERPILLARS.
[25]MOST Caterpillars lurk among the loweſt herbage in the night time, begin to aſcend early in the morning, and about noon are found feeding on the tops of their reſpective plants; they deſcend gradually as the ſun declines, and at the cloſe of the evening are again concealed in the low herbage: night feeders aſcend in the evening, and deſcend as morning approaches.
To collect Caterpillars it is only neceſſary to expand the fowling⯑net, or a large ſheet, under the branches, then beat them with a ſtick or pole, and the Caterpillars will be ſhook down with the frag⯑ments of the foliage and broken twigs.
When you have procured the Caterpillars, be particularly attentive to note the plant on which you found each ſpecies, and ſupply them plentifully with freſh food every day of that kind; only obſer [...] [...]f they are moulting they muſt not be diſturbed, or the ſtale food be removed, but give a freſh ſupply when the creature has recovered its ſtrength.
Inſects in this ſtate are rarely found on plants which do not afford nouriſhment to their ſpecies, but it ſometimes unfortunately hap⯑pens that ſtragglers are taken on ſome particular herbage, altogether of a different nature to its proper food; and indeed in ſome caſes the moſt ſkilful practical emtymologiſts are deceived, the Caterpillar refuſes to eat of the proffered plant, and dies. Some* will devour [26]indiſcriminately the leaves of almoſt every ſpecies of plants, and are therefore called general feeders; ſome✚ are more limited in this particular, but feed on ſeveral kinds; others* are deſigned to eat the leaves of two or more plants, and a few ſubſiſt on one ſpecies only†.
Neither can any certain criterion be formed as to the part of the plant, for though moſt Caterpillars devour the leaf, ſome ſubſiſt on the roots‡; others on the buds§, flowers, fruit‖, and indeed on every other part** of the plant, ſhrub or tree.
It is not always poſſible if one kind of food cannot be procured with convenience, to determine from the quality of that food, what other kind will beſt ſuit the creature; ſometimes plants of the moſt oppoſite nature have nouriſhed the ſame Caterpillar. The PHALAENA Antiqua has devoured leaves of the thorn, and of the roſe; and has throve well when fed on the poiſonous laurel, and the deadly nightſhade.
They ſhould always have an abundance of food, for ſome kinds devour a very conſiderable quantity in a few days: the PAPILIO Braſſicoe, Cabbage Butterfly, eat in one day twice its own weight of food.
[27]Doctor Lodovico Bellardi, a learned and ingenious Botaniſt of Turin, diſcovered, about ſix years ago, after a number of experi⯑ments, a new method of feeding Silk-worms, when they are hatched before the mulberry-trees have produced leaves, or when it happens that the froſt deſtroys the tender branches. Whether this diſcovery may be applied with equal propriety in other inſtances ſeems at preſent undertermined, though from ſome recent experi⯑ments we are inclined to believe the poſſibility of feeding Caterpil⯑lars in backward ſeaſons in this manner; we have tried ſeveral Caterpillars which were nearly full fed on the leaves of thorns and oak ſo prepared, and have obſerved them to eat it when no other food was given, but cannot ſay how they may thrive if fed on that aliment alone. This new method conſiſts in giving the Caterpillars the dried leaves of their uſual food, powdered and moiſtened; and repeated experiments, ſays our author, prove that they (the Cater⯑pillars of Silk-worms) prefer it to any other, and eat it with the greateſt avidity. The leaves muſt be gathered about the end of au⯑tumn, before the froſt commences, in dry weather, and at times when the heat is greateſt. They muſt be dried afterwards in the ſun, by ſpreading them upon large cloths, and laid up in a dry place after they have been reduced to powder. When it is neceſſary to give this powder to the Caterpillars it ſhould be gently moiſtened with a little water, and a thin coat muſt be placed round the young worms, which will immediately begin too feed upon it.
THE BREEDING CAGES
May be made of deal, in the form repreſented at FIG. 2, PLATE I. with a frame door covered with gauſe, or crape, to admit freſh air; and a hole in the bottom through which the [28]ſtalks of the plants may be put into a phial of water to preſerve them freſh.
Thoſe cages ſhould never contain more than one kind of Cater⯑pillar, as ſome ſpecies devour others; and indeed, if left without food, will devour thoſe of their own kind alſo.
"Let not the boxes which are taken in the pocket for Cater⯑pillars, nor the cages made for breeding Inſects be made of deal or fir, except they be well lined with paper; for the effluvia of the turpen⯑tine, raiſed by the heat of the pocket, or that of the ſun, is ex⯑tremely prejudicial to them, and ſeldom fails to deſtroy the greateſt part of the Caterpillars contained therein for any length of time. The cauſe of the deaths of the Caterpillars, found at the bottoms of cages or pocket boxes, is generally attributed to buiſes got in beat⯑ing the trees for them at the time of collecting them, which is a great miſtake, as thoſe which happen to be injured in beating, ſeldom die till the time of changing their ſkins, or of their transfor⯑mations, and will nevertheleſs eat heartily till either of theſe times approach. If the inſide of the cages or boxes be well lined with paper, as aforeſaid, and air-holes made in the ſides and tops, cover⯑ed with crape, canvas, &c. to admit air, it will in a very great meaſure prevent the above ill effects."—Harris.
Put a ſmall quantity of moiſt earth, about an inch deep, at the bottom of every cage, but if the Caterpillars are large, more in pro⯑portion; always allowing a ſufficient quantity for them to bury in.
The cages muſt never be expoſed to the ſcorching rays of the ſun; on the contrary, place them in ſome cool ſhady ſituation.
[29]And the Chryſalides ſhould be preſerved in ſome cold, or moiſt place, in the winter; for by being kept too dry the earth about them will abſorb the nutritive moiſture from the Animal, thereby not only weakening it, but hardening the ſhell, ſo that its ſtrength will be inſufficient to burſt open the caſe when it ſhould come forth; and thus encloſed it muſt periſh miſerably.
The larvae of many Inſects that feed beneath the ſurface of the earth may be bred by the Aurelian in the following manner: let any box that is about three or four feet ſquare, and two or three feet deep, be lined or covered externally with tin, and bore through the ſides and bottom a number of very minute holes: put into this box a quantity of earth that is replete with ſuch vegetables as you are certain the Caterpillars ſubſiſt on, and ſink it into a bed of earth, ſo that the ſurface may be expoſed to the different changes of the weather, unleſs the ſun is very hot, or the rain heavy; you may then put the Caterpillars into the box, and to prevent their eſcape, cover the opening with braſs or iron net-work.
PUPA.
[30]WE have before obſerved, that Inſects taken in this ſtate are moſt likely to be perfect and vigorous, and are therefore more generally fought for by Aurelians than even when in the Caterpillar ſtate. Some Chryſalides are buried in the earth; ſome penetrate into rotten wood; and ſome lie concealed underneath the bark of trees.
An inſtrument after the form of a hoe or trowel is uſed when you ſearch for thoſe of the firſt kind; and the only places worthy atten⯑tion are at the roots of trees, as oaks, elms, &c. or beneath the un⯑derwood: open the earth cloſe to the tree and ſearch to the depth of ſeveral inches.
Such as penetrate into wood, require more care leſt they be de⯑ſtroyed when the attempt is made to extricate them; ſound on the bark with a ſtick and you will diſcover hollows where no external ſigns are viſible; tear off the bark, and with a knife cut away the wood that ſurrounds the orifice of the cavity to enlarge it, and take out the Chryſalis as carefully as poſſible.
Whether found in the wood, or adhering to the inſide of the bark, it ſhould be preſerved with the ſame ſubſtance in the breed⯑ing boxes; and if found ſpun up on the branches of trees, or in the mould, manage to adjuſt them in a ſimilar manner in the boxes. —They muſt be handled as little as poſſible, and be very careful [31]not to preſs on any part; as the leaſt rough treatment will either kill or cripple the Inſect within.
Swammerdam uſed to hatch the eggs, feed the larvae, and pre⯑ſerve the pupa of aquatic Inſects, in a ſhallow diſh, which he covered with white paper, occaſionally moiſtened, and pierced in ſeveral parts for the admiſſion of air.
PERFECT STATE.
[32]IT is in this ſtate we find an immenſe quantity of Inſects, of whoſe Larvae or Caterpillars we are altogether ignorant; and indeed ſuch are the diſpenſations of Providence to this inferior rank in the ſcale of animated nature, that many are provided with the means of ſubſiſtence, in the moſt ſecret ſituations; they are hatched in the midſt of plenty, and inſtinct prompts them not to remove from it; but when they are matured that ſame inſtinct bids them burſt the ſhackles of their bondage.
Such as wiſh to collect, ſhould pay a proper attention to the ſtate of the weather; if it proves fine, and the ſun emits much warmth, Inſects are very briſk; but if a cold or windy day it will be only a fruitleſs toil to attempt collecting, as all Inſects at ſuch times ſhelter within the herbage, and inſtead of flying upward, as uſual when diſturbed, they dart into the thickeſt of the underwood; or if once they riſe above the buſhes, they are impetuouſly hurled by the current of the wind, far beyond the reach of the fowling-net.
"The Garden White is as good a token for fine weather as may be; when theſe flies are out in a morning, it ſeldom or ever hap⯑pens but a fine day enſues. This fly is alſo called a Tally for the Swallowtail, which appears from the Chryſalis at the ſame time of the year."—Harris.
[33]For the ſmaller kinds of lepidopterous Inſects, before ſun-riſe or after ſun-ſet; though many may be taken by beating the buſhes in the day time.
Butterflies are abroad in the day time only; and the beſt time to collect Moths on the wing, is during the night, eſpecially an hour or two after ſun-ſet.
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, which is then damp but warm. This is the beſt time for collecting, as their wings are leſs liable to ſtiffen be⯑fore they can be ſet.
The males of ſome, if not of every ſpecies of the Moth tribe, and perhaps of other Inſects alſo, by a very aſtoniſhing faculty, are able to diſcover the females at a great diſtance, and in the moſt ſecret ſituations; this has been before noticed by Barbut, Harris, and others; and ſome collectors have endeavoured to find the male In⯑ſects by this means; they encloſe the living 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 female. This experiment is generally practiſed with ſucceſs on the Fox, and Egger, Moths.
Every ſpecies has a diſtinct time for its appearance, and this punctuality is ſcarcely forwarded or retarded a few days, except by the unuſual mildneſs or inclemency of the ſeaſon: if you diſcover a brood of Inſects at a certain time of the year, preciſely or nearly at the ſame period of the year following, you will find a brood of the ſame ſpecies; unleſs by accident they have been deſtroyed. It [34]is true that ſome Inſects are very variable in this particular*, and appear in one ſeaſon but diſappear the next; which however will not be obſerved with moſt kinds.
It is alſo to be remembered that certain ſpots of ground, or par⯑ticular ſituations, ſhould always be noticed; thoſe are termed by collectors the haunts of Inſects, and however unneceſſary this may appear, experience will enſure, that ſome kinds are confined to one certain ſpot, and are not to be found in any other part of the ſame wood; ſo that having once diſcovered the haunt of an Inſect, you may be able every ſeaſon to take ſome of that ſpecies; or perhaps oftener, as ſome kinds have two or more broods every ſummer.
The ſequeſtered vale, the hill, meadow, garden, and even dung⯑heap, are the uſual haunts of certain ſpecies; the PH. HUMULI has been called the Ghoſt, not only from its white colour, but as being generally ſound in church-yards, where an abundance of burdock is permitted to grow; the PH. GROSSULARIATA, Large Magpie or Currant Moth, is moſtly found in gardens; the PH. FESTUCAE invariably near marſhes; the Heath Moth receives its Engliſh name from the ſituations it is always diſcovered in; and the ſpecies of Butterfly known to collectors by the name Chalk-Hill Blue, is taken on the chalky hills and pits leading to Darent Wood, [35]a little diſtance beyond Dartford, Kent; the uſual haunts of the Red Arches Moth, is among the oaks, &c. within the intricacies of the wood; but of the Scallop-Shell Moth, the ſkirts or lanes near; the Meadow Brown Butterfly, in meadows; the Gothic Moth, againſt banks; and moſt coleopterous Inſects, or Beetles, in dung, &c.
Having now given an outline of all the rules which appear neceſ⯑ſary for the purpoſe of collecting Inſects, we ſhall proceed to their preſervation, which above all will act as a particular incitement to the early collector, who it is ſuppoſed would feel very little pleaſure at the recollection that all the fruits of his toil in one ſeaſon would be deſtroyed in the next; or at beſt that his ſpecimens would only retain a wretched veſtige of their original perfection.
SETTING AND PRESERVING OF INSECTS.
[36]COLLECTORS are generally ſatisfied, if they can obtain the In⯑ſect in its laſt, or fly ſtate, but as a few inſtructions for the preſer⯑vation of the Egg, Caterpillar, and Chryſalis, may induce ſome future Naturaliſts to enrich their cabinets with ſuch ſpecimens, in addition to the Inſect itſelf, we have ſelected a few particulars for their purpoſe.
THE EGG.
The eggs of moſt Inſects retain their form and colour well, if preſerved in the cabinet, but thoſe which do not promiſe fairly, may be prepared after the method practiſed by Swammerdam; he uſed to pierce the eggs with a very ſine needle, and preſs all the contained juices through the aperture; then inflated them until they regained their proper form by means of a ſmall glaſs tube, and laſtly filled them with oil of ſpike, in which ſome reſin had been diſſolved.
THE CATERPILLAR.
[37]The preſervation of Inſects in this ſtate, is not only one of the moſt curious, but uſeful diſcoveries that have been made in this de⯑partment of ſcience. They may be preſerved by being plunged into phials filled with well rectified ſpirits of wine: this method ſhould ever be preferred by thoſe who collect in a diſtant country, if their ſubjects are not likely to be injured by ſuch a proceſs, the moſt delicate Caterpillars will retain their exact ſize, but the ſpirits will generally extract the colour, and from thoſe eſpecially which have very tender ſkins.
But the manner in which Swammerdam preſerved his Caterpillars, completely obviates this defect, and if carefully managed, it not only preſerves the exact ſize, but generally retains the colours as per⯑fectly as in the living creature.
He uſed to make a ſmall inciſion or puncture in the tail, and having very gently and with much patience preſſed out all the con⯑tained humours, injected wax into them, ſo as to give them all the appearance of healthy living Inſects. In this manner he has preſerved many very ſmall ſpecimens.
There is another method which is more generally known to col⯑lectors; it conſiſts in taking out all the inſide of the Caterpillar, and inflating the ſkin by means of a glaſs tube.
The entrails, with whatever of the ſleſhy ſubſtance can conve⯑niently, is drawn through the anus by means of ſine wire curved at the end; when the inſide is emptied, the glaſs tube is inſerted [38]into the opening, through which the operator continues to blow while he turns the ſkin at the end ſlowly round over a charcoal fire; this hardens the ſkin equally, and dries up all the moiſture within; a pin is then put through it to fix it in a ſtanding poſition: if the ſkin is tender it may be filled with white paper or cotton.
But this is a moſt cruel operation on the little victim, and ſuch as muſt ſhock the feelings of the human ſoul; if therefore any other method can be introduced which will effect the purpoſe in a ſhort time, the practice ſhould be exploded as wanton barbarity.
Various attempts have been made, and among theſe ſome have tried to drown the Caterpillar, but you will never be able to ac⯑compliſh its death in this manner, unleſs it remains for a conſiderable time under water, and though it may appear dead, the principle of life will not be deſtroyed. Mr. Bonnet, making experiments on the reſpiration of Inſects, had one Caterpillar which lived eight days with only two of its anterior ſpiracula in the air.
The method we wiſh to recommend is to obſerve when the Cater⯑pillar is on the point of caſting its laſt ſkin; drop it by the threads into ſcalding water, and quickly withdraw it; the creature will be killed inſtantly; then put it into ſome diſtilled vinegar mixed with ſpirit of wine, which will give a proper firmneſs to all the parts and ac⯑celerate the ſeparation of the ſkin from the body; the fleſh may be carefully extracted, and the exuvia or ſkin be blown up by means of a glaſs tube while ſuſpended over a charcoal fire, as before de⯑ſcribed.
Anoint it with oil of ſpike in which ſome reſin has been diſ⯑ſolved, unleſs it is a hairy Caterpillar.
THE PUPA OR CHRYSALIS.
[39]When Inſects have quitted the pupa ſtate, the caſe will require only to be put into the drawers or boxes with ſome camphire, but thoſe which have the Inſects within, muſt be either dropped into ſcalding water, or incloſed in a ſmall chip box, and expoſed to the heat of a fire, which will ſhortly kill the Inſect within.
I have found that if thoſe chryſalides which have the appearance of gold, are put into ſpirit of wine they will always retain that co⯑lour, but if the Inſect within is killed firſt, or if the fly has quitted it, ſuch appearance is entirely loſt.
THE LAST, OR PERFECT STATE.
[40]COLEOPTEROUS INSECTS, OR BEETLES.
THE preſervation of this order of Inſects, is attended with very little difficulty.
If you drop them into ſcalding water they die in an inſtant, but the moiſture they imbibe can never be ſufficiently exhaled to prevent mouldineſs, after they have been a ſhort time in the cabinet.
The beſt method is to encloſe them in a ſmall chip box, and kill them by expoſing the box to the heat of a fire; this treatment will rather abſorb, than add to the ſuperfluous juices of the Inſect, and greatly contribute to its preſervation.
Thoſe of the Meloe genus have ſoft tender bodies which ſhrivel after death; to preſerve thoſe, make an inciſion at the extremity of the abdomen, probe out the entrails and fill the cavity with fine tow.
[41]Several foreign ſpecies of Caſſida, and many other coleopterous Inſects, are beautifully variegated with a golden colour that dies with the creature; if you plunge them into well rectified ſpirit of wine, when alive, they ſoon expire and retain their golden appearance; but if taken out and dried, that brilliance will be irretrievably loſt.
The Chineſe ſeldom take care to diſplay the parts of their Inſects after the European manner; thoſe we receive from China are ſtuck on long needles; if Beetles often through one elytra, ſo that the membranaceous wings are entirely concealed.
If the Inſects require only a little relaxation to extend the parts, uſe a camel's hair pencil moiſtened with ſpirit of wine; but if this ſhould prove inſufficient, fix them on a piece of cork and float them in an earthen pan half filled with water; it is better to cover the pan with a damp cloth, and the Inſects will be ſo limber, after a ſew hours, that they may be reſet in any poſition.
Large Beetles are uſually ſtuck through one of the ſhells, as at FIG. 5, PLATE II; but ſmaller Inſects are better if diſplayed on a ſmall piece of card, as at FIG. 6, PLATE II. (they muſt be fixed to the card with ſtrong gum); or they may be pierced through the head as at FIG. 7, PLATE II.
Inſects of the hemiptera order, as Cimices, &c. may be treated in the ſame manner.
LEPIDOPTEROUS INSECTS, AS BUTTERFLIES, HAWK-MOTHS, AND MOTHS.
[42]IT is uſual to put two ſpecimens of each ſpecies of the Butterfly kind into the cabinet, one to diſplay the upper, and the other the under ſide; for the under ſide is much more beautiful in moſt ſpecies, and differs entirely in appearance from the upper ſide.
Sphinxes and Moths are generally diſpoſed in pairs to ſhew the male and female, and as their under ſides are ſeldom very beautiful, only their upper ſides are ſhewn.
Except a few ſpecies, Moths conſtantly conceal their under wings when at reſt; but collectors ſacrifice the propriety of their remain⯑ing in a natural poſition, in order to diſplay the under wings.—It is adviſable to have one of every kind in a natural poſture, as that will often eſſentially aſſiſt to determine the family of the Inſect.
Provide a quantity of card braces, made in the ſame form as that repreſented at FIG. 8, PLATE II; and a board of a convenient [43]ſize, covered with ſoft cork; it muſt be perfectly even on the ſur⯑face, and papered; this is termed the ſetting board.
For ſmall Moths it is only neceſſary to put the pin through the thorax and they die in a very ſhort time; but for larger kinds, the pin ſhould be dipped in ſtrong aqua fortis before it is put through the Inſect.
It is very difficult to kill the largeſt kinds of Moths and Sphinxes:—ſelect a large pin (comparatively for the ſize of the Inſect) and dip it into aqua-fortis as before, but immediately that the pin is forced through the thorax withdraw it, and put a drop of aqua fortis into the wound; ſhould this prove inſufficient to kill it, put the point of the pin through a card, and hold it in the flame of a candle until it becomes red hot; this will kill the Inſect immediately, and the card will protect it from being injured by the flame.
The Moth is then to be fixed on the ſetting board, and the braces are to be applied in the manner ſhewn at FIG. 9, PLATE II. The wings are to be carefully diſplayed by means of a large pin, and the braces put cloſe down to prevent their return to the natural poſition.—Note, All Inſects muſt be ſet while they remain limber, for if the parts ſtiffen they are apt to ſnap; they may be relaxed by floating them in a pan of water.
Inſects ſhould remain beneath the braces on the ſetting board until all the aqueous moiſture be evaporated, or the wings will ſtart from their poſition, and the bodies turn black, or mouldy; they ſhould be placed in a dry ſituation, and be covered with gauſe for [44]the admiſſion of air for the ſpace of a month at leaſt, before they are put into the cabinet.
It is proper in this place to caution the young beginner not to at⯑tempt to kill the Inſects by fumigations of ſulphur, &c. a practice too frequent with perſons of this deſcription, for ſhould be by this means deprive the creature of its life, he will alſo deprive it of its beauty: It is even doubtful whether many may not ſurvive the operation.
M. Lyonet placed ſeveral of the large Muſk Beetles, probably the Cerambyx Moſchatus, under a glaſs where he had been burning ſul⯑phur, and which he kept burning while they were there; and though the vapour was ſo thick that he could not diſcern them, and that he kept them therein more than half an hour, they did not ſeem in the leaſt incommoded*.
Some Moths are very liable to change colour when placed in the cabinet, and particularly thoſe which collectors term full-bodied; an oily matter is common to all Inſects, but thoſe are charged with a ſuperabundance. It appears at firſt in ſpots on the body, but gradually pervades every part; in ſome it will even deſcend into the wings, and then an obliteration of all the tender marks and beautiful ſpecklings is the leaſt that may be expected, if a total change of its colours, to an uniform dirty brown, does not enſue. Hence it is that many of the Linnaean deſcriptions of In⯑ſects appear defective to ſuch as breed them; we not unfrequent⯑ly read, body black, though we know that part of the Inſect is [45]white in every ſpecimen that is not greaſy; the body of the Satin Moth* is perfectly white when fine, but after it has been killed ſome time, it becomes black in parts; the body of the Burnet Sphinx† is of a very brilliant blue colour, with yellow bands on every annulation, when alive, but changes to a velvety black ſoon after the Inſect dies; the ſame is obſerved on the body of the Currant Sphinx‡; and every part of the body of the Hornet Sphinx§ changes to a jet black, after being ſome time in the cabinet; although when alive it is a very bright yellow, with a band of purple. Hence alſo it is that ſome ſpecimens of very common Inſects are valuable, by having preſerved their proper colours uninjured.
Various methods have been tried to extract the greaſe from the Moths, but a preventative ſhould always be preferred.
If the greaſe has not ſpread into the wings, the Inſect may ſome⯑times be cured, but it will be very difficult, if not impoſſible, to eradicate the greaſe which has ſettled in patches on the wings.
Large Moths are to be opened in a ſtrait line along the under ſide of the body, the entrails, &c. taken out, and the cavity filled with fine tow or cotton.—Note, This ſhould be performed ſoon after the Inſect is dead. The moſt delicate ſpecimens may be preſerved entire by this means; we have ſome very valuable Sphinges, Moths, &c. which were collected by an intelligent perſon in North America; they retain their colours to the utmoſt degree of perfection, and have only been prevented from changing black by this ſimple pre⯑paration.
[46]Sometimes it will be proper to break off the body cloſe at the thorax, and ſubſtitute the body of another Inſect which nearly re⯑ſembles it, and which is not ſo liable to change.
The method which is moſt ſucceſsful for recovering the original appearance after the Inſect has become greaſy, is to powder ſome fine dry chalk, on a piece of heated iron; cover the chalk with a very fine linen cloth, and thereto apply the under part of the body of the In⯑ſect: the heat of the iron diſſolves the greaſe, while the chalk ab⯑ſorbs it, and the linen cloth prevents the chalk from clotting to the Inſect. This proceſs may be repeated ſeveral times if the greaſe is not entirely eradicated by the firſt attempt. Always-obſerve to exactly attemperate the heat of the iron.
They may be baked in a ſlack oven, with the chalk placed to ab⯑ſorb the greaſe, without any conſiderable injury to the colours.
Some collectors open the bodies of large Moths, take out the en⯑trails, and fill the cavity with fine dry powdered chalk.
MINUTE MOTHS.
TINEA, TORTRIX, ALUCITA, &c.
Much experience, and conſiderable care, with a light, but ſteady hand, are neceſſary for the management of minute Moths on the ſetting board; it will be equally uſeleſs and impoſſible, to enter into a minute detail of every trivial circumſtance that muſt be attended to, we ſhall therefore give a general ſketch, and leave the reſt to the ingenuity of the operator.
Firſt, the fans of the clappers, or forcepts, or the fowling-net if you prefer it, muſt be covered with ſilk gauſe, of a very ſoft and [47]delicate texture, and as the ſlighteſt friction will obliterate the beau⯑tiful ſpecklings, or raiſed tufts that are ſo profuſely beſtowed by the hand of nature on this moſt elegant tribe of Inſects, you muſt be extremely careful when you preſs on the thorax not to cruſh it more than you can poſſibly avoid; or if you have it between the fans of the forceps, put the pin through the thorax while the creature is confined in that ſituation.
The next care will be to procure pins of ſuch a degree of fineneſs, as not to injure or diſtort the wings of the Inſect; the ſmalleſt ſort of lace pins will do very well for moſt kinds, but there are ſome ſo extremely minute that even thoſe would be too coarſe. If you have pins made purpoſely for Inſects of this kind, let them be about an inch in length, and have them drawn as fine as poſſible.
When the pin is put through the thorax it muſt be managed with the greateſt dexterity, and be exactly in the center, as the leaſt va⯑riation to either ſide will break the nerves of the anterior margin of the upper wings, which will immediately ſtart, and can never be replaced in a proper poſition; if the pin is placed too high, it will ſever the head from the ſhoulders, and by being too low, the under wings alſo will break off or ſtart from their true poſition; it may be managed better with the aſſiſtance of a magnifying eye glaſs.
The braces are to be made of the ſame form as thoſe which are uſed for larger Inſects, only ſmaller in proportion; and inſtead of making them of ſtiff card, or paſteboard, they may be ſmall ſlips of vellum, or ſtout paper that has been hot-preſſed. You muſt brace them immediately after you have put the pin through the thorax, for if they are permitted to ſtiffen, they cannot be relaxed ſo well as larger Inſects.
[48]Minute Moths are to be found in winter as well as ſummer; it would be ſcarcely imagined, nay reaſon would deny, did not experi⯑ence prove, that when the froſt is ſo ſevere as to entirely ſubvert the appearance, and almoſt annihilate the exiſtence of all the vegetable productions, within the verge of its influence, myriads of thoſe deli⯑cately formed creatures brave the inclement ſeaſon, and exiſt ſecure⯑ly within thoſe habitations they have the addreſs to conſtruct.
A very ſkilful Entomologiſt informs us that having occaſion to go into the country when the cold was intenſely ſevere and the ſnow deep, he collected in a few hours a vaſt number of minute Inſects of the Coleoptera, Hemiptera, and Lepidoptera orders; and though his collection was then very conſiderable he ſelected thirteen new ſpecies, and among them ſeveral which he has never found, but when the weather has been very cold as at that time.
It is proper to obſerve, that thoſe Inſects uſually ſhelter among the moſs, and other extraneous matter that grow on the trunks or branches of trees, or beneath the rotten bark. Gather the moſs, &c. into a box, or tin canniſter, and ſhut it cloſe to prevent the eſcape of thoſe Inſects, that may revive by the warmth; when you have an opportunity to examine them, ſpread a ſheet of writing paper on the table, and place a lamp, or candle, with a ſhade of tranſparent, or oiled paper before you, ſo as to weaken the glare; then ſeparate the moſs, and ſhake it looſely in your hand, and you will perceive many Inſects fall down on the paper; if they are ſo minute that by thruſting the pin through the thorax they would be damaged, faſten them with gum water, or ſome glutinous varniſh, to ſmall ſlips or pieces of paper.
NEUROPTEROUS, HYMENOPTEROUS, AND DIPTEROUS INSECTS.
[49]AMONG thoſe of the neuropterous order are included the Libel⯑lulae, a moſt elegant tribe of Inſects, but very difficult to preſerve. The colours on the body are exceedingly brilliant in ſome ſpecies, but inevitably change black within a few days after death, unleſs the collector is particularly attentive to their preparation.
They are extremely tenacious of life; we have ſeen one of the larger kinds live two days on the pin, and even ſhew ſymptoms of life twenty-four hours after being deprived of its head.
The moſt expeditious method of killing thoſe creatures, is to run a red hot wire up the body and thorax, for they will live a conſidera⯑ble time in agony if you attempt to kill them with aqua-fortis as before directed for the Moth tribe.
After they are dead, clean their bodies on the inſide with a little cotton twiſted to the end of a wire, and put a roll of white paper into the cavity, or fill it with cotton; in moſt ſpecies this will not only admirably relieve the colours, but preſerve them from chang⯑ing black.
[50] Note, Thoſe kinds only with tranſparent ſkins will require this preparation, as the L. 4. maculata, &c.
Some of the foreign Inſects of thoſe orders appear to the greateſt advantage in ſpirit of wine, but whenever the uſual method will ſuffice, it ſhould be preferred. They are all to be ſtuck through the thorax, and obſerve always to put the pin ſo far through, that when it is ſtuck near a quarter of an inch into the cork the feet of the In⯑ſect may only touch the ſurface.
The wings are to be diſplayed with cramps as uſual.
APTEROUS INSECTS.
[51]MANY kinds may be preſerved in ſpirits, or in the ſame manner as coleopterous and other Inſects; but among thoſe we can include very few, if any, of that extenſive genus ARANEA (Spiders), no method having been hitherto diſcovered whereby they may be pre⯑ſerved in their natural colours, for however beautiful they may be when alive, their bodies ſhrivel and their teints become an obſcure brown, ſoon after death; and as the moiſture exhales, the ſize of the body diminiſhes, very little more than the ſkin of it remaining when the creature is ſufficiently dry to be placed in the cabinet.
Spiders caſt their ſkins ſeveral times in the courſe of their lives; the exuviae would be very acceptable to the collector, if they re⯑tained any of the beautiful colours of the living Spiders.
To determine whether ſome ſpecies of Spiders could be preſerved with their natural colours, I put ſeveral into ſpirit of wine; thoſe with gibbous bodies ſoon after diſcharged a very conſiderable quantity of viſcid matter, and therewith all their moſt beautiful colours; the ſmalleſt retained their form, and only appeared rather paler in the colours than when they were living.
During the courſe of laſt ſummer, among other Spiders I met with a rare ſpecies; it was of a bright yellow colour, elegantly marked with black, red, green, and purple; by ſome accident it was unfortunately cruſhed to pieces in the chip box wherein it was confined, and was therefore thrown aſide as uſeleſs; a month or [52]more after that time, having occaſion to open the box, I ob⯑ſerved, that ſuch parts of the ſkin as had dried againſt the in⯑ſide of the box retained the original brightneſs of colour in a conſiderable degree; to further the experiment I made a ſimilar attempt with ſome caution, on the body of another Spider (Aranea Diadema), and though the colours were not perfectly pre⯑ſerved, they appeared diſtinct.
From other obſervations I find, that if you kill the Spider, and immediately after extract the entrails, then inflate them by means of a blow-pipe, you may preſerve them tolerably well; you muſt cleanſe them on the inſide no more than is ſufficient to prevent mouldineſs, leſt you injure the colours, which certainly in many kinds depend on ſome ſubſtance that lies beneath the ſkin.
After inflating them, you may either inject them with fine virgin wax, or anoint the ſkin with oil of ſpike in which reſin has been diſſolved, and dry them in ſome ſhady place.
Of the largeſt kinds of foreign Spiders, the bodies are the only parts which are liable to ſhrivel; if they were prepared in this man⯑ner their proper form would be preſerved.
In 1792, Dr. Withering preſented a paper to the Linnaean ſociety, in which he relates the particulars of a new method of preſerving Fungi, &c.; as we have given an account of this improvement with the inſtructions for the preſervation of plants, we ſhall only obſerve in this place, that the compoſition which he has applied with ſo much ſucceſs as a preſervative of the moſt periſhable tribes of vegetables, may hereafter prove alſo an excellent preſervative for Spiders, and other apterous infects.
THE CABINET.
[53]It is immaterial whether the cabinet is made of mahogany or wainſcot; ſometimes they are made of cedar wood, but very ſeldom of deal or any other wood that is ſoft; the drawers may be from fifteen to thirty inches in length, the ſame, or nearly the ſame in breadth, and about two or three inches in depth; the cork with which the bottoms are to be lined, muſt be choſen as free from cracks as poſſible, it muſt be glued into the drawers to prevent its warping, and be filed, or cut very level; the irregularities ſhould be rubbed even with pummice ſtone, and the whole ſurface be perfectly ſmooth, be⯑fore the paper is paſted over it; the paper ſhould be of the fineſt quality, but neither very ſtout, nor highly ſized; the former being liable to turn the points of the pins, and the latter to injure the inſects by not readily abſorbing the greaſe, which may flow from them: the top of every drawer muſt be glazed to prevent the admiſſion of duſt or air; the glaſs is uſually fitted into a frame of the ſame ſize as the drawer, and is made either to ſlide in a groove, or let in on a rabbet. Some collectors waſh the cork ſeveral times with ſpirit of wine and corroſive ſublimate, to deſtroy the mites; and moiſten the paper after it is paſted on the cork with allum-water.
Obſerve that every crevice in the drawers or boxes muſt be ſtopped to prevent the admiſſion of external air, and always appro⯑priate a quantity of camphire for each drawer, or the mites will de⯑ſtroy the Inſects.
[54]If your cabinets or boxes ſtand in a damp ſituation the Inſect will become mouldy on the antennae, legs, &c. this muſt be cleaned off with a camel's hair pencil, and the cabinets in future be put into ſome place where it will be leſs expoſed to damp.
If you perceive notwithſtanding the camphire, a duſty appearance on the Inſects, add alſo a quantity of muſk, and clean the duſt off with a ſoft pencil; if after this you find more duſt, either bake the Inſects, or diſſolve ſome corroſive ſublimate in ſpirit of wine, and touch the parts that appear duſty with a fine pencil moiſtened in the liquor, which will deſtroy the mites that occaſion ſuch appearance.
The method which Harris adviſes promiſes only to materially in⯑jure the Inſects, or at leaſt change their colours if brilliant, as I have found by experience.
"If at any time the Inſects in a cabinet or box, where they are placed for preſervation, ſhould appear as if growing mouldy, or be infeſted with ſmall animalcule, which is known by a kind of duſt ſeen beneath the abdomen; in this caſe the ſmoke of tobacco is the only effectual remedy, which muſt be blown through the ſmall end of a pipe admitted through a hole made for that purpoſe in the back part of the drawer or box: this not only corrects the putrid and ſtagnant air, but deſtroys thoſe formidable enemies which often de⯑ſtroy whole cabinets of Inſects: this will preſerve them for twelve months, when it will be neceſſary to act the ſame part over again. It may be feared and objected that the ſmoke may in ſome meaſure damage the Inſects, but a little experience will plainly evince the contrary."—Harris.
CRABS, &c.
[55]SUFFOCATE them in ſpirits, either of wine or turpentine, and dry them in an oven.
Or after they are killed, put them into an Ant's neſt; thoſe little animals will devour the fleſh in a few hours and leave the ſhell entire.
Diluted aqua-fortis is uſed to clear off any impurities that may adhere to the ſhell.
VERMES.
This claſs compriſes a number of very ſingularly formed crea⯑tures; moſt of which may be preſerved in ſpirit of wine.
The ASTERIAS, or Star Fiſh, belong to the ſecond order of this claſs; they are very numerous in ſome places on our coaſt, are beautiful when alive, but their colours fade after death. Suffocate them in ſpirits, after which they may be dried and preſerved in boxes with a quantity of muſk and camphire.
TESTACEA. SHELLS.
[56]IN this order are included the whole tribe of ſhells according to the Linnaean arrangement; many diſputes having ariſen reſpecting the proper method of ſtudying the ſubject, Linnaeus made concho⯑logy a branch of zoology, and not of mineralogy, as preceding authors had claſſed them; there however yet remain very ſtrong arguments againſt the method by the animals, although it cannot be denied that the ſhells are only the coverings or habitations, and ſhould not therefore demand our primary attention, or be conſidered as any farther uſeful in eſtabliſhing the mode of claſſification, than as ſubordinate diſtinctions.
Fabius Columna was aſtoniſhed that of all the writers on this ſubject, not one had conſidered the animals that inhabit the ſhells, but owns, that many are ſeldom ſeen by us, and that to diſcover the manners of their life is extremely difficult.
Mr. Adanſon alſo, in his Natural Hiſtory of Senegal, wiſhes to methodize teſtaceous animals by the Fiſh in preference to the ſhells. He obſerves, that there is ſuch an infinite variety of the Libot, or Black Limpet, that it is difficult to meet with two ſhells alike, and that any perſon would be led to conclude that they were diſtinct ſpecies, did not the fiſh or animal prove the contrary by admitting of no ſuch differences. The ſhells differed in colour and form; ſome were white, others grey, aſhen, or black; very flat, or very [57]raiſed; the number of furrows unequal, from twenty-five to fifty; ſometimes rigid, or ſet with ſmall prickles; the jaggings or tooth⯑ings of the Contour alſo differed widely, ſome being ſmall, or mere⯑ly notches, while others were flaſht ſo deep, that they gave the whole ſhell the form of a ſtar with five or ſeven rays.
Da Coſta, whoſe abilities as a concholiſt will require no eulogiurn, has however encountered the objections to claſs by the ſhells, and has convicted Adanſon of having confounded the Libot, or Black Limpet, with the Thorny Limpet, the Beauty, and the Aſtrolepas Lim⯑pets, all as one ſpecies, though they have not the leaſt reſemblance to each other. With reſpect to the fiſh, he allows with Adanſon, that being the ſame ſort is a preſumptive proof of their being in⯑dividuals of the ſame ſpecies, but cannot agree that it is a poſitive or deciſive one. "I will allow him," ſays Da Coſta, "that the whole of the external appearance of the fiſh, and the particular parts are nearly the ſame; yet I think even that is not a poſitive proof, for I imagine, the very ſame kind of animal inhabits different covers or ſhells; as for example, the Snails may be the ſame kind of fiſh, and form the genus, yet vary ſo much in their habitations or ſhells, as to form different ſpecies of that ſame genus, from only the differences of the ſhells or coverings: for the ſhell or covering may be held for as great a character of the ſpecies, as the very fiſh. Thus the volutes called Admirals, Brocades, Purple Tips, or Onyxes, Tigers, &c. though ſuch different ſhells may be inhabited by the ſame kind of fiſh, to wit, a Limax or Snail, and therefore though the Limax or Fiſh is of the very ſame kind, and forms or fixes the genus, yet the ſhells, always conſtant, will fix or define the ſpecies of that ſame genus. An analogy to this bears ſtrong through all the animal kingdom; for ſpecies of quadrupeds are diſtinguiſhed and defined in their genera, from the different colours of their hides; [58]birds by their various plumage; and inſects by their different colour⯑ings, therefore why ſhould not ſhells, which wear ſuch ſtrong cha⯑racters, by the ſame parity of reaſon, form ſpecies of the ſame genus? Or in other words, why ſhould not the ſame fiſh, or genus, yield many different ſpecies, according to the ſeveral characteriſtical differences of its ſhells or habitations?"
This author does not attempt to deny the propriety, but practica⯑bility of claſſing by the animal; he juſtly obſerves, "The vaſt num⯑ber of ſpecies hitherto diſcovered, and the numerous collections made, exhibit only the ſhells or habitations, the animals themſelves being ſcarcely known or deſcribed. Of the ſhells we daily diſcover, few are fiſhed up living; the greater number are found on our ſhores dead and empty. Accurate deſcriptions of animals whoſe parts are not eaſily ſeen or obvious, and anatomical reſearches, are not in the capacity of every one to make; nor are the particular parts and their reſpective functions ſo eaſily cognizable to any but expert, aſſiduous, and philoſophical enquirers. How is it poſſible then to arrange a numerous ſet of animals by characters or parts, we can with difficulty, if ever, get acquainted with, in the far greater number of the ſpecies we collect or diſcover?"
COLLECTING.
[59]LIKE all other kinds of animals, ſhell fiſh have their parti⯑cular reſorts; ſome inhabit only the deep parts of the ſea, ſome are found in leſs depths, others in ſhallows, in bays, and even on the ſhores; it has been alſo obſerved, that many very fine and rare ſpecimens are ſometimes found in narrow ſtraits between iſlands, and in ſhallows of four or five fathom water.
The beſt live ſhells are collected by means of a trawling-net, ſuch as are uſed by fiſhermen, if the depths will permit; they are alſo brought up by the cable in weighing anchor, the log-line in ſounding, &c.
After a ſtorm good ſhells may be picked up on the ſea beaches, or ſhores, as the violent agitation of the water in a tempeſt ſeparates them from their native beds, and often caſts them on the ſhore; but ſuch as have been expoſed for ſome time to the heat of the ſun, or beaten by the waves, are of little value, as their colours will be ſuded, and the ſhells worn and broken; chooſe therefore always ſuch ſhells as lie in the deepeſt parts of their reſorts and under water, whether taken up by the drag-net, from the ſides of rocks, or bot⯑toms of ſhips, &c.
River ſhells are in general very obſcure in appearance, ſeldom ad⯑mit of elegant colouting, and are extremely thin and brittle.
[60]But terreſtrial or land ſhells, though few in compariſon with marine ſhells are no way deficient in beauty, or leſs eſteemed by collectors.
Many ſhells are ſo very beautifully poliſhed when they are fiſhed up, that art cannot improve their appearance, ſuch are the Cowries, Tuns, ſome Buccina, the Volutes, and the Olives.
Da Coſta imagines that the fiſh inhabiting all naturally poliſhed ſhells whatever are capable of not only adding to the extent and growth of their ſhells, but can likewiſe, from time to time, add a freſh poliſhed covering to the whole ſhell; or at leaſt extend their organs to ſuch a length as to clear away all impurities from their ſhells, as we ſeldom find any Cowries with coral or any extraneous bodies adhering to any part of them.
As ſhells are of a calcareous nature, all acids muſt be avoided as much as poſſible; and even when the animals are killed, as much boiling may injure the ſhells, it with be moſt adviſable to dip them into ſealding water, which will kill them, let them remain for two or three minutes to cool, and then put them into cold water, in which they may lie until they are taken out to be cleaned. If the animals die without this precaution the colours will be very dull and obſcure, if not entirely changed.—Thoſe are known to col⯑lectors by the term Dead Shells, and are little valued becauſe the co⯑lours are ſo very much injured.
The fiſh by being killed in this manner becomes condenſed, or ſomewhat ſolid, and may be picked out by any ſharp inſtrument.
[61]The epidermis, or perioſteum, is common to many ſhells, and is perhaps a membrane that covers the ſhells to defend them from exterior accidents, and aid their growth; its ſtructure in different genera varies very much; in ſome it is laminated, in others fibrous or bruſh-like, or as velvet; it prevents ſhell-fiſh or other marine inſects from fixing their habitation on thoſe ſhells, and protects it from the corroding of the ſalt water, for all ſhells that have the epidermis have a ſcabrous ſurface.
Tellens, Muſcles, Snails, &c. come out of the ſea ſlimy or even encruſted with filth, coraline matter, moſs, &c. For theſe, firſt ſteep them in hot water, let them remain therein for twenty-four hours, to ſoften the filth or cruſt, then bruſh them well, with bruſhes that are not too hard; if that proves inſufficient to clean them, rub or bruſh them again with tripoli or emery, or put them into weak acid, obſerving to dip them into cold water every minute; ſtrong ſoap may alſo be uſed with a rag of woollen or linen, to rub them, and when cleaned finiſh them with a ſoft bruſh and fine emery.
The ſcientific collectors ſhould always if poſſible preſerve one of every ſhell with the epidermis on, to exhibit its natural appearance, together with the uncoated ſpecimen.
The epidermis may ſometimes be ſo thick that it will be proper to take it off, before the ſhell can be poliſhed, for that purpoſe pour a proportion (nearly one tenth) of aqua-fortis mixed with common water, into a ſhallow baſon or ſaucer, and place the ſhells therein, in ſuch a manner that the corroſive liquor may act only on the coat, without injuring the orifice, which in ſome caſes may be coated with bees-wax; change the ſituation of the ſhell every two or three [62]minutes, that all the parts may be equally uncoated; wipe off the bubbles as occaſion may require with a feather, firſt dipped in wa⯑ter: when you perceive the enamel of the ſhell in any part free from the coat, take it out and waſh it entirely free from the aqua-fortis; after this proceſs bruſh them with emery, putty, or tripoli.
If inſtead of a thick epidermis it is only a pellicle, it is ſufficient to ſteep it in hot water, and then pick it off; or ſteep the ſhell in vinegar for ſome time till it peels off freely, or is corroded away.
The epidermis of ſome ſhells is ſo very coarſe and ponderous as to reſiſt the corroſive quality of acids diluted, or even ſtrong aqua-fortis; coarſe emery, with ſtrong bruſhes, are then ſubſtituted, and ſeal-ſkin or pumice-ſtone is in ſeveral reſpects uſeful. If the matter is too obſtinate to be cleared off by this means, pour ſome ſpirit of nitre into a cup or other veſſel, ſtop up every part of the ſhell that may be ſuſceptible of injury, with ſoft wax as carefully as poſſible, and put it into the liquor in the veſſel; remove it every minute into cold water, but obſerve never to ſhift it into the ſame water more than once, and waſh it every time before you return it into the corroſive liquor. If the ſhell is warted, irregular, or arm⯑ed with points, examine with a common magnifying glaſs, and if you perceive on the more prominent parts through the coat any appearance of the poliſhed ſurface, cover them with wax, and let the ſhell remain a few moments longer in the ſpirit; take it out and waſh it again, after which poliſh the ſhell with fine emery, and paſs a camel's hair pencil with gum arabic over them to glow the co⯑lours; white of egg is ſometimes uſed, but it is very apt to turn yellow in time, though at firſt it appears glaring; and varniſh com⯑municates a diſagreeable ſmell.
[63]Some ſhells have naturally a ſlight politure, though dull; thoſe muſt be rubbed by the hand with chamois leather, which will give them a bright gloſſy appearance; avoid when poſſible the uſe of powder of emery, as it is apt to detriment the beautiful working on the ſhells; it cannot however be often left out of uſe.
It may be neceſſary as far as can be, to avoid the impoſitions which are often practiſed on thoſe who are not well acquainted with ſhells; at the ſame time that the collector may wiſh to enrich his cabinet with ſpecimens under their ſeveral appearances: thus we ſee that though the outer ſurface of the common Cowry, or Tide Shell, is of a pale colour with dark ſpots, when that is taken off, it is of a fine violet colour; the Sea Ears are clouded with brown, green, and white, but when that coat is rubbed away, it appears a beautiful mother of pearl, and the pearly chambered Nautilus, or Sailor, is of a light ochre colour, variegated with ſtreaks of red, externally, but when that coat is rubbed off, the ſhell is mother of pearl alſo; the ſame circumſtance attends many of the Trochi, Snails, and an infinite variety of other ſhells of different genera. Among thoſe ſhells which alter their appearance moſt, we muſt not omit the Volute, called by us the Purple or Violet Tip, and by the French the Onyx; it has a brown epidermis, which being taken off diſcovers the ground colour to be a dull yellow. When this is worked down to beneath the cruſt or ſurface, it is of a pure white, with the tip of a fine violet colour.—To rub them down in this manner uſe a file, hard bruſhes of boar's briſtles, coarſe emery, &c.
The Dutch frequently ſtain artificial colours on ſhells, ſo as to render it extremely difficult to prevent impoſition; ſometimes they entirely alter their appearance, by filing the mouths, &c.
[64]To examine the internal ſtructure of ſhells, they may be ground down on a hone.
Foſſil ſhells ſhould be noticed here if any inſtructions were re⯑quired for their preſervation, but they, together with minerals, are the moſt durable part of a collection; being either chalky, caſts of ſtone, or replacements of ſparry matter, with perhaps only ſome ſlight fragments of the ſhells adhering. They are dug out of lime, or ſtone quarries, coal pits, chalky cliffs, &c.
The remains of foreign animals, ſhells, and plants which have at different periods been diſcovered in a foſſil ſtate, within the bowels of the earth, in Europe, has been ſuppoſed to exceed the variety and number of thoſe in a recent ſtate, or in preſent exiſtence with us; and although Buffon will not allow ſuch a conſiderable latitude to this circumſtance, he acknowledges that foſſils are extremely numerous in Europe as well as in every other part of the univerſe, and appears ſatisfied that ſhells, &c. may be diſcovered wherever we are diſpoſed to ſeek for them.
Strata of ſhells have been found at the greateſt depths from the ſurface of the earth that have ever been examined, and in equal abundance on the ſummits of the higheſt mountains, for example, on mount Cenis, in the mountains of Genes, in the Apennines, and in moſt of the ſtone and marble quarries in Italy; in the marbles of the moſt ancient buildings of the Romans; in the mountains of Tirol; in the center of Italy, on the ſummit of mount Paterne, near Bologne; in the hills of Calabria, and in many parts of Ger⯑many, Hungary, &c.
[65]In Aſia and Africa they have been obſerved by travellers in many parts; on the mountains of Caſtravan above Barut there is a bed of white ſtone as thin as ſlate, each leaf of which contains a great number and diverſity of fiſhes; they lie for the moſt part very flat, and compreſſed, as do the foſſil of fern-plants, but they are not⯑withſtanding ſo well preſerved that the ſmalleſt traces of the fins, ſcales, and all the parts which diſtinguiſh each kind are perfectly viſible. Many petrified ſhells are alſo found between Suez and Cairo, and on the hills and eminences of Barbary. Alſo according to Bourguet in the long chain of mountains which extends from Por⯑tugal to the moſt eaſtern parts of China.
"Oppoſite the village of Inchene, and on the eaſtern ſhore of the Nile, are found petrified plants, which grow naturally in a ſpace about two leagues long, by a very moderate breadth; this is one of the moſt ſingular productions of nature. Theſe plants reſemble the white coral found on the Red Sea*."
"There are petrifactions of divers kinds on mount Libanus, and among others flat ſtones, where the ſkeletons of fiſh are found well preſerved and entire; red cheſnuts, and ſmall branches of coral, the ſame as grow in the Red Sea, are alſo found on this mountain."
According to Dr. Woodward, foſſil ſhells are met with from the tops to the bottoms of quarries, pits, and the deepeſt mines of Hun⯑gary; and Mr. Ray aſſures us, they are found a thouſand feet deep in the rocks which border the Iſle of Calda in Pembrokeſhire in England.
[66]We would willingly purſue our enquiries farther, were they ſub⯑ſervient to our general deſign, but as we only wiſh to acquaint the early naturaliſt, in what ſituations he may expect to meet with foſſil ſhells, or the remains of animals, &c. we ſhall return to our own country, which abounds in productions of the foſſil kind.
The greateſt variety of ferns, and other foſſil plants, in iron-ſtone, are found at Coalbrook Dale, Shropſhire; ammonites, &c. in Kent, Dorſetſhire, Glouceſterſhire, Cornwall, Bath, &c. and foſſil ſhells in general are abundant in chalky cliffs, and clay ſoil. To convey ſome idea of the extenſive variety of foſſil ſhells, &c. in this country, it will be only neceſſary to mention the Foſſilia Hantonienſia, the figures contained in that work amount to one hundred and twenty-one different kinds, although they were only collected in the county of Hampſhire, out of the cliffs by the ſea coaſt, between Chriſt Church and Lymington, and about the cliffs by the village of Hordwell, which is nearly in the mid way between the two former places; they were found in their natural ſtate, excepting their loſs of colour, and ex⯑ceedingly well preſerved, below a ſtratum of gravel and ſand about fourteen or fifteen feet thick, in a bluiſh kind of clay or marle, quite down to the level of the ſea, how much deeper is not known; the heights of theſe cliffs are, in many places, above one hundred feet.
We cannot better conclude this diſcourſe, than by ſubjoining the following extract from the preface of that work.
"This ſtratum of clay runs a great way into the country in a northerly direction quite acroſs the New Foreſt, as may be perceived when ſinkings are made in the earth for buildings, or pits for the digging of marle, where foſſil ſhells, on ſuch occaſions, frequently [67]occur, together with thoſe other bodies here mentioned, by which it appears, that along with the teſtaceous tribe, fiſh and quadrupeds became involved in the general confuſion; the ſhores under theſe cliffs abound with large noddules of iron ore, and pebbles or flints, in many of which when broken are diſcovered foſſil ſhells, or their impreſſions, and the eſcharae here deſcribed.
"Various are the opinions concerning the time when and how theſe bodies became depoſited; ſome there are who conceive it might have been effected in an indefinite length of time by a gradual chang⯑ing of the ſea; others again, that this globe may have undergone many, even total revolutions, of which we neither have or can have any idea, but by theſe traces.
"The moſt common cauſe aſſigned is that of the deluge, but the notion that an overflowing of the waters, during the time men⯑tioned in ſcripture, although the univerſality of it ſhould not be called in queſtion, could have looſened the intire contents of the whole earth, according to Dr. Woodward, and have rendered all that was ſolid, fluid, for the admiſſion of the ſpoils both of the ſea and land, into the centre of the hardeſt rocks, nay even pebbles and flints, is equally hypothetical with other conjectures; ſo that upon the whole, I am apt to think this affair will for ever remain a myſtery. I ſhall therefore content myſelf with making a few general obſerva⯑tions on the ſubject, the better to enable ſuch as are leſs converſant in theſe matters to judge for themſelves.
"Theſe phaenomena then, upon an inquiſitive ſearch over as great a part of the globe as we have any knowledge of, except in a very few inſtances, are found to be univerſal; for from the ſurface of the higheſt mountains in the moſt inland parts, down to the great⯑eſt [68]depths in the earth ever penetrated, where openings have been made, are found ſhells, bones, and vegetables, petrified, or pre⯑ſerved in their natural ſtate, in earth, ſand, clay, marble, flint, &c. and in ſuch abundance, that the teſtaceous tribe eſpecially are equal in variety to thoſe found recent, and in quantity infinitely exceed them. The greater part of theſe foſſil extraneous ſubſtances that are known, are found to be inhabitants of ſouthern latitudes, as the ſkeletons of Elephants, Crocodiles, Sharks, and almoſt all the vege⯑tables; and of the teſtaceous tribe are found the Ammonitae, Belem⯑nitae, Stellae Marinae, Anomiae, &c. now in general not known in the recent ſtate, inhabitants no doubt of the great deep, or of ſome unknown ſeas or ſhores; all of which are met with in great plenty in this our iſland*."
M. de Juſſieu imagines, that as the bed of the ſea is continually riſing in conſequence of the mud and ſand which the rivers in⯑ceſſantly convey there; the ſea, at firſt confined between two nar⯑row dykes, ſurmounted them and was diſperſed over the land, and that the dykes were themſelves undermined by the water and over⯑thrown therein; hence he accounts for the impreſſions of ſo many exotic vegetables on the ſtones of St. Chaumont, in France; which are all either natives of the Eaſt Indies, or the hot climates of Ame⯑rica, and are not to be found in the recent ſtate in any part of France.
LITHOPHYTA, ZOOPHYTA, &c.
[69]SEA WEEDS only require to be waſhed in freſh water, and dried between ſheets of paper.
For the preſervation of ſome kinds of Corallines, &c. it will be neceſſary to waſh them firſt in ſpirit of wine to kill the inſects which are concealed in the hollows or crevices, and then in common wa⯑ter to clear off the extraneous matter, &c.
A receipt for cleanſing white corallines, &c. when dirty, or changed black, is very little known; put them into a mixture of ſoap-ſuds and a ſmall quantity of pearl-aſhes, and rub them therein with a ſoft bruſh; however changed, or dirty they may be, their fineſt degree of whiteneſs will be regained by this proceſs. Fumiga⯑tions of ſulphur will alſo whiten coral that has turned black.
In the laſt order it only remains for us to notice the Polypes, whoſe very aſtoniſhing power of reproducing the parts, which they may be occaſionally deprived of, has given birth to ſo many learned diſcuſſions in every part of Europe.
We often obſerve at the bottoms of ſhallow pools, or on the plants which grow in, or recline on the ſurface of ſtagnant water, a number of ſmall tranſparent lumps, about the ſize of a pea, and ſlatted on one ſide; thoſe are Polypes in an inactive ſtate: they are [70]generally fixed by one end to ſome ſolid ſubſtance, at the other end is an opening, which is the mouth of the creature, and the arms ſhoot forth round it in the form of rays.
They are generally found in waters that move gently; neither rapid ſtreams, nor ſtagnant waters ever abound with them; they adhere to aquatic plants, to rotten wood, ſtones, &c. They are ſeldom met with in winter, but in the month of May they begin to appear, and are to be found in ditches all the ſummer.
When you ſearch for Polypes it will be beſt to take up a quantity of the pieces of wood, &c. that are uſually found in ditches, and put them into a glaſs of water, let it ſtand for a while without moving it, and if there are any Polypes adhering to theſe ſubſtances, you will perceive them ſtretching out their arms in ſearch for their prey.
Mr. Trembley diſcovered that a ſmall ſpecies of Millepede was an excellent food for thoſe little animals; they will alſo devour the Pulices Aquatices, the ſmall red worms which are found in the mud banks on the banks of the Thames, common worms, the larva of gnats, and other inſects, and even butcher's meat if cut ſmall enough.
If a ſufficient quantity of the red worms which are found on the mud banks, be gathered in the month of November, and put into a large glaſs, with three or four inches of earth at the bottom, the Polypes may be fed in the winter; cleanſe the worms before they are put in among the Polypes.
[71]To preſerve thoſe creatures in health, it will be proper to change the water in which they are kept very frequently, and particularly after they have done eating; the water muſt be poured off, the Poly⯑pes taken out, and the ſides and bottom of the glaſs waſhed free from all ſlimy ſediment. To take them out, firſt looſen their tails from the ſides or bottom of the glaſs; then take them out ſeparately, with a quill cut in the ſhape of a ſcoop, and put them into a glaſs with clean water.
The power of reproduction is ſo great in thoſe creatures that if a Polype is cut tranſverſely, or longitudinally, in two or three parts, it is not deſtroyed; in a little time each part will become a per⯑fect Polype; even a ſmall portion of the ſkin will produce a new creature.
If a Polype is ſlit, beginning at the head, and proceeding to the middle of the body, a Polype will be formed with two heads, and will eat at the ſame time with both. If a Polype is ſlit into ſix or ſeven parts, it becomes a hydra, with ſix or ſeven heads. If they are again divided it will have twelve or fourteen. If thoſe again be ſevered from the trunk, as many new ones will ſpring up in their place, and the heads thus deprived of the body will become new Polypes alſo.
Thoſe who may wiſh for farther information relative to the va⯑rieties, habits, and properties of Polypes, we refer to the Eſſays on the Natural Hiſtory of Polypes, by Henry Baker*; to Memoires pour ſervir à l'Hiſtoire d'une Eſpece de Polypes d'Eau douce, par M. Trembley†; to Lettres d'Eugene à Clarence au Sujet des Animaux [72]appellées Polypees‡, and particularly to Mr. Adams's Eſſay on the Mi⯑croſcope§, in which the reader will find a circumſtantial detail of the moſt material diſcoveries and experiments that have been made by different naturaliſts, on thoſe ſingular creatures.
The inſtructions for their preſervation as microſcopic objects, as they were given by Mr. Baker, and ſince inſerted in Mr. Adams's Eſſay, will be particularly uſeful to the early naturaliſt, not only ſo far as relates to Polypes, but as with care many animals of a ſimi⯑lar texture may be preſerved by the ſame means.
"Chuſe a proper Polype, and put in a ſmall concave lens, with a drop of water; when it is extended, and the tail fixed, pour off a little of the water, and then plunge it with the concave into ſome ſpirit of wine contained in the bowl of a large ſpoon; by this it is inſtantly killed, the arms and body contracting more or leſs; rub it gently, while in ſpirits, with a ſoft hair pencil, to cleanſe it from the lice.
"The difficulty now begins; for the parts of the Polype, on being taken out of the ſpirits, immediately cling together, ſo that it is not practicable to extend the body, and ſeparate the arms on the talc, without tearing them to pieces: ſo that the only method is, to adjuſt them upon the talc while in the ſpirits; this may be done by ſlipping the t [...] under the body of the Polype, while it lies in the ſpirits, and diſplaying its arms thereon by the ſmall hair pencil and a pair of nippers; then lift the talc with the Polype upon it, out of the ſpirits, take hold of it with the nippers in the left hand, dip the pen⯑cil [73]in the ſpirits with the right hand, and therewith diſpoſe of the ſeveral parts, that they may lie in a convenient manner, at the ſame time bruſhing away any lice that may be ſeen upon the talc; now let it dry, which it does in a little time, and place the talc carefully in the hole of the ſlider. To prevent the upper talc and ring preſſing on the Polype, you muſt cut three pieces of cork about the bigneſs of a pin's head, and the depth of the Polype, and fix them by gum in a triangular poſition, partly on the edges of the ſaid talc, partly to the ſides of the ivory hole itſelf; the upper talc may then be laid on theſe corks, and preſſed down by the ring as uſual."
PLANTS.
[74]PLANTS are ſometimes tranſmitted from one country to another, by ſlips or cuttings, but as thoſe require the ſkilful management of the gardener during the paſſage, roots or ſeeds ſhould always be preferred. It is, however, very difficult to lay down any preciſe mode of treat⯑ment that will anſwer for all ſeeds indiſcriminately: ſome kinds keep beſt expoſed to the air; while others are preſerved by a total excluſion of it*. The ſeeds of parſley, lettuce, onions, &c. kept in vials hermetically ſealed a twelve month, did not vegetate, while thoſe of the ſame age and ſort hung up in bags in a dry room, vege⯑tated freely.
In Ellis's directions for bringing over ſeeds and plants, the neceſſity of giving freſh air to ſome ſeeds is clearly proved†, though it is [75]certain that the vegetative power of many other kinds can only be preſerved by a total excluſion of air, as coating them with wax or encloſing them in tin canniſters, &c.‡
[76]Some ſeeds will retain their vegetative property for a conſiderable time if buried in a bed of earth, a foot or more below the ſurface§; others may be encloſed in vials, corked and ſealed with a compoſi⯑tion of melted reſin and bees-wax, and placed in caſks or boxes of ſalt; and the ſeeds of moſt aquatic plants ſhould be tranſmitted in water.
Seeds which contain much oil, and are of a warm nature, may be generally kept for a conſiderable length of time without any injury; thoſe of parſley, carrots and parſnip, it is ſaid, will not grow if more than a year old.
Colonel Davies has given the following uſeful inſtructions for the tranſmiſſion of plants from one country to another.
[77]"With reſpect to ſhrubs and plants, I would recommend (as I have from conſiderable experience found) their being dug up care⯑fully, ſo as to break the roots as little as poſſible; when about eighteen inches, or two feet high, waſh all ſtones and earthy parti⯑cles away from the roots as clean as poſſible with freſh water, pro⯑cure boxes of any kind of wood inch thick, thirty or thirty-ſix inches long, fourteen or ſixteen wide, and as many deep; bore a conſider⯑able number of holes with a large gimblet in the bottom and lid. Cover the bottom with ſoft long wet moſt, about an inch or two thick, and lay the plants with their tops towards the ends of the box as cloſe as poſſible, about two inches deep: cover them with a layer of wet moſs, inch deep, and proceed with another layer of plants, and ſo on until the whole of the box is filled, covering the upper layer of all with wet moſs in like manner. If ſome moſs is alſo added to the ends of the box the better, as their being preſſed cloſe down in the box does not damage or injure them; many by ſo doing may be packed in a ſmall ſpace. Nail on the top of the box and immerſe it under water in a pond, river, or tub, for a few minutes to admit it into the moſs; it may then be kept in any damp cellar or out-houſe free from harm, until ſent on board ſhip, and requires no further trouble, but once in five or ſix weeks to pour ſome freſh water on the top or bottom, through the holes, to moiſten the moſs within. In this manner vaſt quantities of ſcarce and va⯑luable plants may be eaſily tranſported from one part of the globe to another. Although I have never yet made the experiment myſelf, I am confident that all kinds of nuts, and hard ſeeds, may be ſent in this manner from place to place with great probability of ſecurity and ſucceſs; as the vegetative part of the ſeed, by being nouriſhed by the moiſture of the moſs, will be ſurer preſerved, than by any other mode I have heard of. Small ſeeds will do very well in dry papers, or in ſmall bottles, mixt with dry ſand that has not been [78]near ſalt water; bulbs keep admirably well alſo in freſh dry ſand or moſs, packed in ſmall boxes or kegs."
From countries which we are not permitted to explore, as China, Japan, &c. the curious traveller may obtain many rare plants, if he will examine the fodder that is brought down from the country, by the natives; the indefatigable Thunberg *, who was commiſſioned to collect ſeeds and ſpecimens of plants in Japan for the medicinal garden at Amſterdam, was prevented by the jealouſy of the Japaneſe from herbarizing in that country for a conſiderable time after his arrival, but from the fodder which he examined very carefully every time it was brought down from the country for the cattle, he for⯑tunately ſelected many rare and curious plants.
FERNS.
We cannot diſmiſs thoſe inſtructions for the preſervation or tranſ⯑portation of ſeeds, without taking notice of a very intereſting diſco⯑very which Mr. John Lindſay, a ſurgeon in Jamaica, communicated to Sir Joſeph Banks, Bart. in the year 1789, relative to the germi⯑nation [79]and raiſing of Ferns from the ſeed. We ſhall not preſume to follow this gentleman through the whole of his very pleaſing diſcourſe, but refer our readers, if they deſire a farther account, to the thirteenth article of the Linnaean Tranſactions, Vol. II.
Mr. Lindſay, as being an aſſiſtant to Dr. Clarke, botaniſt for that iſland, could not be ignorant of the various opinions which were entertained by botaniſts reſpecting the fructification of this tribe of plants, and of the difficulty of raiſing them from the ſeeds; having ſome ſpare time when he arrived at Jamaica which he could with propriety dedicate to a minute obſervance of thoſe plants, he en⯑deavoured to aſcertain their ſeed; their minuteneſs rendered every at⯑tempt to diſcover them, by ſearching at the roots of even the ſmalleſt viſible plants fruitleſs, he then thought of ſowing the powder or duſt which falls from the leaves when drying in a flower-pot, and ob⯑ſerving their progreſs; to do this with care and certainty he mixed ſome of the powder with ſome of the mould it was to be ſown in, and by the aſſiſtance of the microſcope was ſoon able to diſtin⯑guiſh the different parts of the powder, or fructification from the mould in which it was ſown. He next proceeds to relate the altera⯑tions which he obſerved in the ſeeds of ſeveral ſpecies, from the firſt ſymptoms of vegetation to the expanſion of the leaves, and illuſtrates the progreſs by ſeveral figures and ſuitable references. Engaging in the practice of medicine ſoon after, he thought no more of the ſubject, till he had the honour of a very polite letter from Sir Joſeph Banks, Bart. by which he was induced to re⯑ſume his obſervations, and tranſmit his valuable diſcovery to England.
[80]He ſays "the ſeeds of Ferns may be procured with readineſs and eaſe by taking thoſe frondes or leaves on which the fructification is copious, fair and conſpicuous; which are of full growth, have a healthy appearance, and are more expoſed to the free air than con⯑fined in the ſhade. Theſe leaves, laid on clean paper in a dry place, ſoon ſhed their ſeed in the form of duſt or fine powder, of colour varying from black or brown to yellow; the groſſer part of this powder is the empty capſules, and that very fine part which adheres cloſe to the paper is the ſeed. The ſeeds thus procured may be ſown immediately, or kept in paper in a dry place."
He next determines, that like other vegetables, many ſpecies of Ferns requires a ſoil and ſituation peculiar to themſelves; he took equal parts of brick mould and good pit marle, at ſome depth below the ſurface, to avoid the ſeeds of other plants, mixed them well together, and with this filled the flower-pot, moiſtened it pro⯑perly, and made the ſurface very ſmooth; he then divided it into ſmall ſpaces, according to the number of the different kinds in⯑tended to be ſown in it; and laſtly ſtrewed the ſeeds lightly on the ſurface. The ſeeds which are ſown in this manner ſhould be placed in a heat correſponding to that of their native climate, in a place rather moiſt than too dry, freely open to the light and freſh air, but ſo ſhaded that the direct rays of the ſun cannot reach them.
OBSERVATIONS On the Manner of making a HORTUS-SICCUS.
[81]The Abbé Hauy, of the royal academy of ſciences at Paris, in the year 1785, preſented that ſociety with the following intereſting obſervations, relative to the preſervation of dried plants.
"Of all the productions of nature, there are none more ſuſceptible of change than vegetables, or which require more care and attention for their preſervation. Flowers, in particular, ſoon loſe their colours in an herbal, and aſſume others, quite different from thoſe beſtowed on them by nature. Yellow grows pale, or becomes nearly effaced; blue or red are ſtill more apt to fade or diſappear entirely. The flowers of the Violet, the Campanula, of ſeveral ſpecies of Gera⯑nium, and a multitude of other plants which add to the ornament of the fields, and often to that even of our gardens, become, in a few days ſo much tarniſhed, that they cannot be known by any eye but that of an experienced botaniſt.
"This inconvenience I have endeavoured to remedy, at leaſt, in part; and as I found it almoſt impoſſible to fix the natural colours of plants, I attempted to diſcover a method of ſubſtituting artificial colours for them which might not fade, ſo that the flower, by pre⯑ſerving its bloom, and all its eſſential characteriſtics, might in ſome degree exhibit its natural colour. For this purpoſe, I painted a piece of fine paper with water colours in ſuch a manner as to have, as much as poſſible, the ſame degree of ſtrength as thoſe of nature, [82]only a little fainter, for a reaſon I ſhall mention hereafter. When I had done this I threw the leaves into ſpirits of wine, where they ſoon loſt all their colours, and were reduced to whitiſh tranſparent membranes. After having dried them thoroughly, by preſſing them between two folds of a fine cloth, I laid them on the coloured paper by means of a thick varniſh, which I took care to ſpread over the paper in order that they might adhere to it, I afterwards drew another paper, ſeveral times over the flower preſſing it ſtrongly with my hand until all the leaves were properly applied, and until the artificial colours appeared through them. In this operation the colours become a little darker; for which reaſon it will be neceſſary to make the tints a little fainter than what they are naturally. I afterwards left the flower a few moments in a preſs, then, having cut the paper around it, I applied it with a diſſolution of gum⯑arabic to the place it ſhould occupy on the plant, which had been before fixed by means of the ſame diſſolution to a piece of paper of a proper ſize.
"It will be of great ſervice when thoſe flowers even are applied, which have permanent colours, ſuch as the greater part of the wild Ranunculuſes, to begin by cementing the flowers to a piece of paper, and to cut it round the leaves, as in the preceding caſe, before they are added to the plant. This operation renders them more natural, and if their poſition is ſuch that they cover the leaves of the plant, which will often happen, the colour of the leaves does not injure that of the flowers, by appearing through their delicate membraness, which are in part diaphonous.
"There are ſome plants, the leaves of which, on account of their thickneſs and ſpongy ſubſtance, cannot eaſily be dried, and which become black before their juices have been extracted by the [83]ordinary mode of drying. Such, among others, are thoſe of the orchis. I have obſerved that by peeling off, with a pointed knife, the thin pellicle which covers the lower part of theſe leaves, before I cemented them to the paper, it greatly haſtened their deſiccation, ſo that it generally took place in two or three days, and even in a much ſhorter ſpace of time. The leaves then preſerved their ver⯑dure in a great meaſure, or, at leaſt, aſſumed only a tint inclining a very little to yellow, without ever appearing of that black colour which indicates the laſt degree of decay in a ſpecies of productions the moſt beautiful and pleaſing in nature.
"I have ſubmitted to the inſpection of the academy the Violet, the Geranium, and the common Poppy of the fields, the artificial colours of which have preſerved their luſtre for many years, I have added alſo three ſpecies of orchis, the leaves of which ſtill retain their freſhneſs after being dried ten years, the ſummer Adonis and common Cinque Foil, &c. the natural colours of which have been preſerved without any other precaution than the care I took to dry them between folds of warm paper as ſpeedily as I poſſibly could, and not to expoſe them to the air, or to moiſture."
This method may be applied to moſt plants, with the greateſt proſpect of ſucceſs; but as the time it will require to preſerve only a few ſpecimens may be more than every collector can ſpare, a more ſimple proceſs is recommended; dry the plants between the leaves of a large book, or ſheets of ſtout paper, and preſs them even in a ſcrew-preſs, or let them remain under a heavy weight for ſome time; then ſpread a thin coat of gum-arabic on the paper, and diſplay the plants thereon as ſmooth as poſſible. They ſhould after this be covered with a thin coat of copal varniſh to preſerve them from the ravages of infects, or the ill effects of damp.
[84]Plants loſe all their native verdure in ſpirit of wine, but pre⯑ſerve their form perfectly well, if therefore they are preſerved on account of the ſingular ſtructure of any part, it is beſt to keep them in bottles, with either ſpirit of wine, rum, or brandy, &c. Spirit of wine diluted with common water will preſerve the colours of ſome plants tolerably well.
The moſt intereſting diſcourſe we have met with on the pre⯑ſervation of vegetables, is that which Dr. Withering communicated to the Linnaean Society in December, 1794; it is inferted as the 23d article of the ſecond volume of the Tranſactions of that Society. Dr. Withering has confined his diſcourſe to the preſervation of Fungi, only obſerving that Moſſes and Lichens might be preſerved in great perfection by the ſame methods.
He obſerves that acids, even thoſe of a mineral origin, are apt to produce mouldineſs; that neutral ſalts often deſtroy the texture of the plants; though perhaps a weak ſolution of common ſalt, with a ſufficient quantity of ſpirit of wine, might be uſed advantageouſly for the preſervation of Fuci, and other marine vegetables. Earthy ſalts ſeem uſeleſs, except alum, which preſerves them tolerably well for a time, but at length they are apt to become mouldy.
For the preparation of the liquors No. 1 and No. 2, which he found moſt efficacious, he has given the following directions. No. 1. "To half a pound of vitriol of copper, called blue vitriol, reduced to powder, add a pint of cold water: ſtir them together for a minute, and then throw away the water: upon the remain⯑ing vitriol pour half a pint of boiling water: and ſtir them fre⯑quently until the liquor be nearly cool. Set it by in a warm place, for two or three days, to cryſtallize.
[85]"Take any quantity of theſe cryſtals, add to them as much hot water as will barely diſſolve them, and put the ſolution into a vial.
"To two or three quarts of pure ſpring water, put as much of this ſolution of blue vitriol as will give the whole a very ſlight bluiſh tinge: then add to it, rectified ſpirit of wine, in the pro⯑portion of a pint to a gallon: filter the liquor through blotting or cap paper, and put it into bottles for uſe."
"No. 2. Diſſolve a quarter of an ounce of ſugar of lead in a pint of diſtilled or very pure ſpring water, made boiling hot; add ſeven pints of pure cold water, and one pint of rectified ſpirit of wine: filter the liquor, and keep it in bottles."
"The above proportion of ſpirit of wine is ſufficient for the thickeſt and moſt ſucculent ſpecimens, but leſs will do for ſuch as are thick and not juicy. If the ſpirit be ſufficient to prevent mouldineſs, it is enough, for more has a tendency to extract the colours."
"Put the ſpecimens into wide-mouthed jars made of flint glaſs, and well fitted with corks: fill the jars quite full with one or other of the above liquids, ſo as to leave in as little air as poſſible: cork the jars very cloſe, covering the corks with tin foil, or ſheet lead, ſuch as may be had from the dealers in tea, turning the edge of the lead or tin downwards ſo as to lap over and under the edge of the jar.
"The dark-coloured plants are very apt to diſcolour the liqour, the milky ones to render it turbid, and ſome of the juicy ones to [86]excite the vinous fermentation. In any of theſe caſes the liquor muſt be repeatedly changed.
"I have principally uſed the liquor No. 1; but No. 2 is beſt adapted to preſerve ſome of the more tender colours, and it alſo keeps the texture more firm. Let the botaniſt however be careful not to mix the liquors, not to change one for the other after a plant has been wetted with one of them."
Dr. Withering in the courſe of this diſſertation has alſo given ſome inſtructions for the tranſportation of Agarics; his method is nearly the ſame as that preſcribed by Colonel Davies for the tranſ⯑portation of ſhrubs and plants in general, except that he adviſes to put the plants and moſs in layers into an earthen jar, inſtead of an open box; and to pour in the liquid No. 1, as long as the layers of moſs, between the plants, will continue to imbibe any; then to ſtop up the mouth ſecurely.
FINIS.
