Part 21
Unless the shells are covered with extraneous matter, it is not necessary to clean them. Marine shells are, however, very liable to be incrusted with other marine bodies, particularly with serpula and balani, etc. These must be started off by means of a sharp instrument; an engraving tool is well adapted for this purpose. This must be done with great caution, in species which have spines, and other excrescences, as they are very liable to be broken. Should any of the calcareous matter still adhere, this must be removed, by applying to it a _very weak_ mixture of muriatic acid and water, applied with the point of a quill, and then plunged into water, and allowed to remain till the acid is quite extracted. But on no account whatever attempt to eradicate these parasitic bodies by means of acid, or acid and water alone, as the chances are that the shell will be completely destroyed by their application. We have seen many fine and valuable shells destroyed by an injudicious application of acids—they should never be used when it can possibly be avoided. We have, on the other hand, seen shells which were so completely enveloped in calcareous crust, that it was impossible to trace their external surface, most thoroughly cleared of all this, without being touched at all by acids, the whole being removed by a small knife or other sharp instrument; and these, in many cases, having long and tender spines externally.
Nothing can be more monstrous than the application of pumice-stone, which some recommend, for polishing shells; as is also the use of tripoli, rotten-stone, and emery. Neither do we approve the application of varnishes, as such shells never have their natural luster.
If a shell is found dead upon the beach it is probable that it will have undergone a certain degree of decomposition, that is, it will have parted with part of its animal matter, and consequently the colors will have faded and the surface present a chalky appearance. To remove this take a small proportion of Florence oil and apply it to the surface, when the colors which were invisible will appear. When completely saturated with oil let the shell be rubbed dry and placed in a cabinet. Oil may also be applied after acid has been used, and it will be found extremely useful when applied to dry the epidermis, which it will prevent from cracking or quitting the shell entirely, which it frequently does.
Whether marine shells are procured in a living or dead state, a very necessary precaution is to immerse them in pure tepid water after the animal has been extracted, and allow them to continue in it for an hour or two so as completely to extract any salt or acid which may be in them.
Fresh water shells are liable to a calcareous or earthy incrustation, which must be removed by immersing them in warm water, and afterwards scraping and brushing them with a nail or toothbrush. Much nicety is necessary in cleaning these, as their great thinness renders them, in general, liable to be broken. A little Florence oil will improve the appearance of the epidermis and render it less liable to crack.
Land shells seldom require any cleaning except washing in water, as they are not liable to incrustations of any kind.
When shells are perforated by marine animals, or otherwise broken, if the specimen is rare, it is desirable to remedy these defects as far as possible; they may therefore be filled up, or pieces added to them with the cement, which may be colored when dry to its original state.
=Of Polishing Shells.= Many species of marine and fresh water shells are composed of mother-of-pearl, generally covered with a strong epidermis. When it is wished to exhibit the external structure of shells, the epidermis is removed and the outer testaceous coatings polished down till the pearlaceous structure becomes visible. It has been a common practice to remove the strong epidermis of shells by means of strong acids, but this is a hazardous and tedious mode of operating. The best method is to put the shells into a pan of cold water with a quantity of quicklime and boil it for two to four hours, according to the thickness of the epidermis. The shells afterwards must be gradually cooled, and some strong acid applied to the epidermis, when it will easily peel off. Two hours are sufficient for the common muscle being boiled. The shells are afterwards polished with rotten-stone and oil, put on a piece of chamois leather.
The epidermis of the uno margaritifera is so thick that it requires from four to five hours boiling. After the epidermis has been removed, there is beneath it a thick layer of dull, calcareous matter, which must be started off with a knife or other sharp instrument; this requires great labor, but, when accomplished, a fine mother-of-pearl is exhibited which adds an agreeable variety as a specimen.
Various turbos and trochuses are also deprived of their epidermis and polished with files, sand-paper, pumice-stone, etc., till the pearly appearance is obtained; but all these modes are invented for disfiguring rather than improving the shells in the eye of the naturalist, and should never be resorted to except where the species is very common, in which case it is well enough to do so with one or two specimens to show the structure of the shells.
After the operation of polishing and washing with acids, a little Florence oil should be rubbed over to bring out the colors and destroy the influence of the acid.
THE CHASE AND MANNER OF COLLECTING ANIMALS.
QUADRUPEDS AND BIRDS.
It is hardly necessary to recommend a double-barrelled gun. One of the barrels should be loaded with small shot or dross of lead for small birds and the other with large shot. These should have much less powder than an ordinary charge, so as not to tear and injure the animals. Paper, cotton or flax and powdered dry earthen ashes should form part of the naturalist’s stores.
When a bird is killed, a small quantity of dry dust is to be put on the wound. For this purpose the feathers must be raised with a pin, or a gun-picker, close to the wound. The bill of the bird should have a small quantity of cotton or flax introduced into it to prevent the blood from flowing and spoiling the plumage. The feathers must be all adjusted, and the bird then placed on the ground to allow the blood to coagulate. Every specimen should be placed in a piece of paper of the form of a hollow cone, like the thumb bags used by grocers. The head should be introduced into this, the paper should then be closed around the bird, and packed in a box filled with moss, dried grass or leaves.
Birds taken alive in nets and traps are to be preferred to others for stuffing, and also those caught by birdlime, which must be removed by spirits of wine.
Birds should always be skinned the same day they are killed, or next day at farthest, particularly in summer; as there is a danger of putrefaction ensuing, by which the feathers will fall off. However, in winter there is no danger for some days; but in tropical climates they must be prepared soon after they are killed. The same observations apply generally to quadrupeds.
Bats and owls are caught during the day, in the hollows of aged trees, in the crevices of walls, and ruins of buildings. These are animals which, it may be presumed, are still little known in consequence of their nocturnal habits.
Those who prepare for the chase, with the intention of preserving animals, should take care to provide themselves with implements necessary for fulfilling the objects advantageously. The articles most needed are one or two pairs of large pincers, scissors, forceps, scalpels, knives, needles, thread and a small hatchet, as well as one or more canisters of preserving powder, some pots of arsenical soap, or arsenical composition, and some bottles of spirits of turpentine. Cotton may be employed in stuffing the skins, and therefore a considerable quantity should always be taken along with the naturalist. In parts of Asia and Africa, where this cannot be procured, tow must be employed, or old ropes teazed down; and where even this cannot be found, dried grass and moss may be used. M. Le Vaillant used a species of dog-grass while in Africa, which is very abundant in that country; and it answered the purpose remarkably well.
It being supposed that a traveler has an ample caravan, provided with all the necessaries which we have pointed out, and having killed a quadruped, he will skin it immediately, according to the method which we have pointed out. He will then sew up the skin after receiving a partial stuffing, and having been anointed with the arsenical soap or composition. All the extremities must then be imbued with spirits of turpentine, and the skin should be placed in some convenient place to dry, so that it may have the advantage of complete exposure to the air. The turpentine must be again applied at the end of three or four days, more especially around the mouth of the quadruped.
It will be of the utmost advantage to remain a week or ten days at one place; by which means the naturalist will have had time to render himself somewhat acquainted with the animals which localize in that neighborhood. And as some species frequently confine themselves to a very limited spot, by leaving the place too hurriedly he is apt to overlook them.
After the traveler has determined on leaving his cantonment, he must see that all the objects he has collected are in a condition to be removed. He must examine carefully each specimen, and see that they have not been attacked by the destructive insects, so abundant in warm climates. Should flies have deposited their eggs in the lips of the quadrupeds or birds, these must be destroyed by spirits of turpentine. When a set of animals or birds are thoroughly dry, they should be packed in a box or case, which has been well joined.
A journal ought to be kept detailing all the circumstances connected with the animals, the places in which they were killed, and the color of their eyes, together with any information that can be procured of their habits from the natives. People are too apt to forget particulars when engaged in such varied pursuits, and the sooner they are committed to paper the better.
When the traveler arrives in Africa, he will meet with animals of the largest size, such as the elephant, the rhinoceros, hippopotamus, giraffe, quagga, urus, bubulus, condoma, as well as large antelope and deer. He will unquestionably find some difficulty in his endeavors to bring with him the skins of these animals, as in that country it is even troublesome, in many cases, to transport the necessaries of life. But the ardor of the zealous naturalist will here be increased by beholding such splendid specimens as he can never meet with elsewhere. All his energies will be strengthened and every sacrifice made to enable him to transport the fruits of his toils.
We need only to recur to the zeal manifested by Le Vaillant in his travels, and the rapturous delight experienced by him when he first beheld and killed the giraffe. He brought this large skin from Caffraria, where he killed the animal, a distance of two hundred leagues from the Cape of Good Hope.
Should the traveler, accidentally, or in pursuit of natural objects, find himself possessed of the carcase of one of these large and fine animals, he would deeply regret not being able to fetch away the skin from want of a knowledge how to separate it from the body. We shall, therefore, suppose that he has killed an animal the size of a bull. He must first make an incision under the belly, in the form of a double cross. The central line must reach from the chin to the anus; the two other transverse cuts must reach from one foot to the other. These are always made inside, so that the seams may be less conspicuous when the animal is mounted. When the skin is stuffed, the hoofs are detached by laying them on a stone, and striking them with a hatchet or mallet. The nails or hoofs must be left attached to the skin. After this, the skin is removed from the feet, legs, and thighs, and treated in other respects as pointed out in skinning other large animals. The bones of the head must be preserved if possible, leaving it attached at the muzzle only. All the muscles must be removed from the head, and the bones rendered as clean as possible.
As it is probable that an animal of this magnitude has been killed at a great distance from any habitation, there will not be an opportunity of macerating the hide in alum and water. The skin will also be too thick for the arsenical soap to penetrate with effect. Under these circumstances, the next best thing to preserve it is to take the ashes of a wood fire, and rub it well inside. The skin should then be stretched along the boughs of a tree, and allowed to dry. The skull, after it has been dried, must be returned into the skin, and the lips, ears, and feet imbued plentifully with turpentine, which operation must be several times repeated at intervals. Nothing is more effectual in preventing the attacks of insects than this spirit, and no larvæ will exist in places which it has touched.
The skin will be sufficiently dried within two or three days, so that the hair may be turned inwards. If some common salt can be procured, a solution of it should be made, and the hair rubbed with it. Both sides of the skin must be rubbed with this two or three times, at intervals of a day.
When sufficiently dry, the skin may be rolled up and packed. The hair ought to be inwards, with a layer of dried grass intervening, to prevent friction during conveyance. The operation of rolling up the skin must be begun at the head.
If the journey is long, the skin should be unrolled, and placed in the sun for a few hours, and the places liable to the attack of moths should be again rubbed with turpentine.
When a skin thus prepared has reached the place where it is to be put up, it must undergo a preparation previous to its being mounted. In the first place, it must be extended along the ground with the hair undermost, so that it may acquire fresh pliability, and those parts which remain stiff must be moistened with tepid water. The skin must then be placed in a large vessel of water saturated with alum, there to remain eight or ten days; after which, it must be extended on half rounded pieces of wood, and thinned with a sharp knife, which is facilitated by the projections of the wood, enabling the operator the more easily to cut it, while it is gradually shifted, till the whole has been pretty equally thinned. When this operation is completed, it is allowed to soak in water with an equal quantity of that saturated with the alum. Twenty-four hours will be sufficient.
In hunting for snakes, great caution must be exercised, as it is well known that the bite of some of these proves fatal within a quarter of an hour, particularly that of the rattlesnake and some others. Indeed, it would be more prudent to allow the natives to hunt for these poisonous reptiles, as they are better acquainted with their haunts, and the means of defense to be employed in this dangerous pursuit. They are also better acquainted with those which are poisonous. We may, however, remark, that the poisonous snakes have, in general, much larger heads than those which are harmless, and their necks are also narrow.
=Shells.= Shells, on account of the elegance and variety of their forms, and beauty of their colors, are objects much sought after, not only by naturalists but also by most persons who are unacquainted with science. There is no species, particularly in remote climes, which does not deserve to be brought home, the things most common in those countries being frequently the most rare in ours. Shells are found on every part of the surface of the globe. Some are inhabitants of the land, while others only frequent rivers, lakes, ponds, and ditches; and another and more numerous class live in the ocean. Land-shells are spread over the whole surface of the earth, and although more accessible, are perhaps less known than those which inhabit the “mighty deep.”
=Land-Shells=, for the most part, are to be found creeping abroad either in the evening or after a gentle shower of rain. During the heat of the day they retire to shaded retreats, under thick bushes, the crevices of rocks, the hollows of decayed trees, or under their bark; beneath stones, amongst moss, or in holes in the ground. A little experience will teach the naturalist readily to find their retreats.
=Fresh Water Shells= must be sought for, if in deep lakes, with a dredge, or if in shallow places, with a tin spoon fixed on the end of a stick. This is made of a circular piece of tin four inches and a half in diameter, beat concave, and then perforated with numerous small holes, not exceeding the sixteenth part of an inch in diameter; around this must be soldered a perpendicular rim three-quarters of an inch broad, and also perforated with holes. To this must be attached a hollow tubular handle three inches long, for the insertion of a walking-stick. It must have a few holes towards its outer end for passing a string through to tie it firmly and prevent it being lost. With this spoon the collector must rake along the mud at the bottom of ditches or ponds, and after bringing a quantity to the surface, he must wash the mud entirely away by shaking the spoon on the top of the water, and it will pass through the holes and leave the shells. The sharp edge of the spoon is also useful for detaching aquatic shells from the under surface of the leaves of water-plants.
The large swan-muscle (_Anadonta Cygnea_), and other ana-dons, generally lie deep in the mud, so that they cannot be procured by dredging. I found it necessary to invent a net to fish for these. This consisted of an iron triangle of twelve inches, with a hollow handle fixed on its base, and in this is inserted a pole of sufficient length to reach the bottom. It is firmly screwed to the handle. A net is attached to the triangle either of twine or hair-cloth. The point of the triangle should be sharp so that it may the more easily penetrate the mud, and it is drawn through it in situations where shells are supposed to exist.
=Marine Shells.= These are to be found in all seas; some of them inhabit rocks on the shore within high-water mark; others reside in deep water, and can only be taken by dredging, or by the use of a kind of net called in France the gangui, and an instrument called the rake has also been successfully used.
Different species of sea-weed are frequently covered by minute shells—weeds should always be carefully examined. Many of the smaller and microscopic shells are found at high-water mark among the fine dross and drifted fragments of shells; this sand should be brought home and examined at leisure. To facilitate the process a small wire-cloth sieve should be made of about six or seven inches square and all the sand sifted through it and the shells left.
=Molluscous Animals.= Many species of worms and other soft, invertebrate animals are to be caught also by the dredge. There is no way of preserving these animals except by putting them in spirits. Animals of this kind are still very imperfectly known, notwithstanding the researches of Lamarck, Poli, and other celebrated naturalists. Every opportunity should, therefore, be embraced of bringing them home; indeed, we are still little acquainted with those which inhabit our own seas.
When animals of this kind are procured in foreign parts a careful noting of the latitude should be taken; and it should be stated whether they live singly or are congregated, if they are phosphorescent, and if they were taken in deep water. And as these animals are very liable to lose their colors by being put in spirits, a careful noting of these should be taken whenever they are caught, as the colors are very evanescent; or, what would be still better, a drawing of the animal should be made.
=Intestinal Worms.= Whenever we have killed either a quadruped, bird, or fish, we should carefully examine the stomach and intestinal canal of the animal to see if there are any worms; indeed, there are few animals without them; they must also be preserved in spirits. Besides the stomach and intestines, worms are also found in the livers and other parts of the body; also in the back of Skates and various fishes.
INSECTS.
This class is subject to infinite variety, according to climate and soil. The entomologist, or the mere collector, must not confine himself to those whose beauty of coloring renders them attractive, but collect all that come in the way. Those species which have wings, and fly around plants, we take by means of gauze nets, and also those which swim in the water. Those which live on putrid substances, and such as are disagreeable to the touch, are seized with pincers; they are first put into camphorated spirits to render them clean. Trees are the habitations of innumerable insects; many of them skulk under the old rotten bark, and others attach themselves to the foliage. A cloth should be spread under the trees, or an umbrella, and the branches shaken with considerable force, when they will fall down, and may then be caught.
Insects are killed by making a crow-quill into a long point and dipping it into prussic acid; an incision with it may be made immediately below the head of the insect betwixt the shoulders, which usually produces instant death. But this acid must be used with much caution, because its effects are almost as instantaneous and fatal in the human subject as in the lower animals. When cork cannot be had for lining the bottoms of the boxes, a layer of beeswax may be used in its stead. The pin should be deeply sunk in this substance, as it is more liable to loosen than when in cork.
It is of much importance to procure the caterpillar as well as the insect, and, in this case, some of the leaves on which it feeds should be placed in a box beside it, so that it may reach maturity. A small perforation should be made in the box for the admission of air.
Every kind of insect, except butterflies, sphinges, and moths, may be preserved in bottles of spirits, which will not injure them; when they are taken out they are immediately placed in the position in which it is wished to preserve them, and they are then allowed to dry. Another mode of preserving coleopterous insects, such as beetles, etc., is to put them in a dry box amongst fine sand. A row of insects is placed in a layer of sand, and then a new layer of about an inch in depth laid on the top, and so on till the box is filled. This mode of packing will not, however, do with soft insects and those having fine wings.
It is extremely desirable that all the different kinds of Spiders should be caught, particularly those said to be venomous; also termites, or white ants, the different scolopendra, and gaily worms, etc. The nests of spiders and other insects should also be sent home; in short, every insect which is remarkable, in any way, either for its history or properties.
It is also of much importance to bring specimens of the plants on which they feed; these should be dried, and their localities marked, the kind of soil on which they grow, and the situations, whether moist or dry, should be noted.
BRITISH INSECTS.