cess

operation (Brown). 6. Accomplishment; qualification: out of use (Shakspeare). PREPARATION OF ANIMALS, and parts of animals of vegetables and parts of vegetables, for the purpose of preserving them.

This is a very extensive and important subject. It is obviously extensive from its range; and it is of great importance, as it affords the best and most direct mode of conveying instruction, and of communicating a knowledge of natural facts, of which, in thousands of instances, we could never otherwise become eye-witnesses. We shall examine it, therefore, in the order in which we have now noticed it, and shall treat successively of the preservation, first of animal, and secondly of vegetable substances.

I. PREPARATION OF ANIMAL SUBSTANCES. Of the two distinct branches, this is by far the most momentous; and it has been studied to a certain extent in all ages.

Animals are prepared in such manner that the exterior and entire form may be preserved; or only that particular parts of it, dissected from the rest, may be distinctly and permanently presented to the view. The former method comprises the art of embalming and of preparing animals for cabinets and museums of natural history: the latter comprehends the art of anatomical and zoctomical preparations.

Embalming This appears first of all to have been practised in Egypt, where it constituted a branch of medical science, and was carried to so high a degree of perfection, that the bodies which were the subjects of it, and which, when duly prepared, were called mummies, have in many instances been preserved to the present day, and have consequently descended through a period of many thousand years. Upon this topic, however, we have already treated, under the word EMBALMING, and without encumbering our pages further, shall refer the reader to that article.

Preparation of animals for mu eums.-The art of chemistry, which is of high importance in the process of embalming, is of equal value in the assistance it affords the naturalist in the preparing quadrupeds, birds, fishes, and other animals, for his cabinet of curiosities. It points out the means not only of giving them duration and consistence, but of continuing to them as long as possible their general appearance in a living state, their natural attitudes, positions, and distinctive characters.

Reaumur will be found to have published a treatise upon this subject, in the Philosophical Transactions, vol. XLV. and there is another treatise that at one time was regarded as of considerable consequence in the Dictionaire d'His toire Naturelle; neither of which, however, are very satisfactory, or capable of leading us to much perfection in this delicate art. The hints thrown forth by Dr. Hunter, and to which we have adverted in the article EMBALMING, are of far more importance, and should be studied and put in practice in connection with the directions afforded by the principal writers upon this subject, among whom we may place Kuckham, Chaptal, and Pinel.

Kuckham published a process for the preparation of birds in the Philosophical Transactions, vol. LX. His composition to preserve them from putrefaction is a mixture composed of a quarter of a pound of corrosive sublimate; half a pound of

calcined saltpetre; a quarter of a pound of calcinced alum; half a pound of flowers of sulpher; a quarter of a pound of musk; one pound of black pepper; and one pound of pulverised to bacco: these are to be kept mixed together in a well-closed glass vessel, and in a dry place The corrosive sublimate is an useful ingredient in the preparation of various quadrupeds: but it is fatal to all except the coleopterous or crustaceous in sects; and another objection to the entire com pound is its expence. On this last account, Pinel recommends the following substitute : equal parts of corrosive sublimate, or arsenic, calcined alum, camphor and canella, or any other are matic: all which are in like manner to be pul verised and mixed together.

Pinel has also strongly recommended the fol as a profound secret, and was well known to lowing varnish, which was for a long period lept have been employed with great success, espe sects in the skins of dead animals, as well as n cially in preventing the generation of minute destroying them if hatched: so that for three or four years, till they can be conveniently placed in the coljection for which they are designed, the keeping such preparations under glasses may be dispensed with, and they may be packed up with out injury in close cases. It is composed of the following articles: Four ounces of pulverised and the mixture is to be gently heated; a quantly arsenic are to be put into one pound of brandy, of black soap and aloes are then to be added, 10 ly extended while warm in the interior of the as to form a kind of magma, which must be lightanimal with a brush, the soft parts having been removed, the same process being applied to the external surface of the skin. When used, however, he recommends it to be diluted with alkohol: and immediately after its use the preparation should be mounted, as the evaporation of the fluid part occasions the skin to become harsh and difficult to soften again.

to be impregnated, with which the interual parts It is with this magma that cotton or flax ought of animal bodies are to be filled; a d it is found to be far superior to the mixture composed of a solution of camphor in rectified spirit of wine, which is the preparation commonly used in our own country. It is likewise necessary that the zoologist should be provided with caustic soda, a solution of which corrodes the soft parts, and by uniting with the fat parts forms a species peated lotions. Chaptal recommends the cranium of soap that is afterwards easily taken out by re and intestines, when deprived of their contents, to be syringed with sulphuric ether.

preserved by being kept in spirit of wine; for Small animals or parts of large ones are often which purpose it is remarked by Leonhardi that a little water and a fifth part of spirit of sal ammoniac should be added, which will continue the colour and the softness.

Anatomical preparations.

bid state. We shall notice both in their order. These consist of viscera in a healthy or a mor Preparations of the viscera in a healthy state —The a healthy state, either to exhibit their form various parts of the body may be preserved in or structure, or to compare them with morbid parts.

parts dissected away, the part to be preserved is When removed from the body, and the useless

to be soaked in water, in order to get out the blood.

When it is necessary to give parts their natural form, which is lost by macerating; put them into a saturated solution of alum, or rectified spirit, retaining them by any means in the required form until they become hardened. If it be a hollow part, as the stomach, bladder, &c. fill it with, and immerse it in, the solution, or spirit.

When an opening is to be exhibited, as that of the ureter, the bile-duct, the lacunae of the urethra, Stenonian duct, Fallopian tube, &c. introduce a bristle.

After this manner preserve the uterus and its appendages, cutting open the vagina and cavity of the uterus, the bladder, intestine, stomach, Heart in the pericardium, liver, spleen, kidney, &c. &c.

air.

All preparations of the brain are best hardened in a saturated solution of corrosive sublimate. The parts are to be suspended in proof spirit by raw silk, in a tie-over bottle, and covered with putrid bladder, taking care to exclude all When dry, varnish the bladder with mucithen put a sheet lage of gum arabic several times; of thin lead over, and varnish its edges with mucilage; and, lastly, tie another bladder over, and give it a coat of common spirit varnish, in which lamp-black, or other colouring matter, is mixed, or with Brunswick varnish.

Preparations of morb d parts.—All morbid parts should, immediately after their removal from the body, be put into rectified spirit of wine for a day or two, and then preserved in proof spirit. These preparations foul a great quantity of spirit, and should therefore be kept in stopper-glasses, from which the spirit can easily be removed, and fresh put in, until the preparation ceases to foul the spirit, when it may be put into a tie-over bottle.

Preparations made by macerating.—Preparations obtained by this process are very

various.

Let the water be frequently changed, until it is no longer coloured with blood, but never after the blood is steeped away. Let the macerating pan be placed in a warm place, to facilitate putrefaction, for if it be put in a cold place, the spermaceti-like conversion of the soft parts will be formed, and the part spoiled. The soft parts surrounding bones are a long time before they detach themselves from the bones. Bones, when macerated, should be exposed to the sun's rays, and frequently wetted with clean water, or they may be bleached with the diluted oxygenated

muriatic acid.

Bones are macerated, to be preserved whole; or they are sawed, to expose their internal structure. In preparing the bones of the head, put the whole head, without disturbing the flesh or brains, into the pan. When sufficiently macerated, all the soft parts will come away with the periosteum; then detach the vertebræ, and wash out the brain. Bones are separated from each other by filling the cranium with peas, and putThe same method is to be ting it into water. adopted with other bones.

In preparing bones in general for structure, divide the femur into two halves: the os innominatum, the petrous portion of the temporal bone, the parietal bone, &c.: these, when macerated, will exhibit the compact, the spongy, laminated, and reticular substance of bones.

Fetus-Cut carefully away the fatty substance

enveloping a fœtus, but do not cut any of the
cartilages. Steep out its blood, and macerate.
It should be frequently looked at, and taken out
when the flesh is all destroyed, before the carti-
lages are separated. The following preparations
are obtained in this way:

The superior extremity, to shew its bones, the
progress of ossification, and the cartilage to be
formed into bone. The lower extremity, to ex-
pose the same circumstance. The spine, which
forms a beautiful preparation. The pelvis, not.
The mode of preservation is by
less elegant.
proof spirit.

The cuticle of the hand and foot may be sepa-
rated by maceration: the former is called chiro-
theca, the latter podatheca. The arm and foot of a
large foetus are to be preferred; they are first to
be well washed with a soft sponge in soap and
water.

Preservation-Suspend them in proof spirit: first tie the part by which they are to be suspended, then put them into the bottle with the spirit, and gently pour some spirit into the cuticle, to distend it like a glove or stocking.

Injecting instruments.-The celebrated Dutch anatomist, Ruysch, first invented the art of injecting animal bodies; hence it is termed the Ruyschian art.

There are three kinds of apparatus used in making injected preparations. The one for the coarse and fine injections, and the minute injection; the other for injecting with quicksilver; and the third, called the oyster syringe, for injecting minute preparations with the minute injection only.

The first consists of a brass syringe made for the purpo-e, of various sizes, from one carrying six ounces to one sufficiently large to hold two pounds. The point of these syringes is adapted to the pipes into which it is to be affixed. To this syringe belong a stop-cock, and a great variety of pipes.

The instrument for injecting quicksilver consists of a long glass tube, at whose end is fixed, by screwing in, a steel pipe, the end of which is extremely fine.

The oyster syringe is similar to the large syringe, except in size. It is so small, that when the syringe is in the hand, and full, its piston may be commanded by the thumb of that hand to throw its contents into any preparation in the other hand. The pipe affixed by being screwed to the end of this syringe is nearly as small as that belonging to the quicksilver tube.

These instruments are always to be had at the surgical instrument-makers.

The injections employed for anatomical purposes are of four different kinds: coarse, fine, minste, and mercurial.

Course injections.-Red.-Yellow bees' wax, sixteen ounces-the palest resin, eight ounces-turpentine varnish, six ounces, by measure-finely levigated vermilion, three ounces.

Yellow.-Yellow bees' wax, sixteen ouncespale resin, eight ounces-turpentine varnish. six ounces-king's yellow, two ounces and a half.

White.-Fine virgin wax, sixteen ounces-pale resin, eight ounces-turpentine varnish, six ounces-best flake white, five ounces and a half

Pale blue.-Fine virgin wax, sixteen ounces-pale resin, eight ounces-turpentine varnish, six ounces-best flake white, three ounces and a RR 2 half-fine blue smalt, three ounces and a half,

Dark blue.-Fine virgin wax, sixteen ouncespale resin, eight ounces-turpentine varnish, six ounces-blue verdiler, ten ounces and a half. Black.-Yellow bees' wax, sixteen ounces-pale resin, eight ounces-turpentine varnish, six ounces -pure lamp-black, one ounce.

Green.-Yellow bees' wax, sixteen ounces-pale resin, eight ounces-turpentine varnish, six ounces-levigated crystallized verdigrise, four ounces and a half-best flake white, one ounce -levigated gamboge, one ounce.

Liquefy the wax, resin, and turpentine varnish over a slow fire, in an earthen pipkin; then add the colouring matter, having previously mixed it in another pipkin, with a very small quantity of the melted composition. Stir the whole well together with a wooden pestle, so that the colour ing ingredients may be intimately and smoothly blended; place the whole again over the fire, and, when they have acquired their due heat, the injection will be fit for use.

Fine injections.-Brown spirit varnish, white spirit varnish, of each four ounces-turpentine varnish, one ounce.

These are to be put together in an earthen pipkin, over a slow fire, until they have acquired the necessary degree of heat. To make it of a red colour, put one ounce of fiuely levigated vermilion into another pipkin, and gradually add the heated materials, stirring the whole with a wooden pestle, that the colour may be equally

diffused.

One ounce and a quarter of king's yellowtwo ounces of best flake white-one ounce and a half of fine blue smalt, with one ounce and a quarter of best flake white-four ounces of blue verditer-half an ounce of pure lamp-black-are the proportions for the various colours to the quantity of ingredients ordered above.

Minute injections.-The size, which forms the vehicle to the colouring matter in these injections, is made in the following manner:

Take, of the finest and most transparent glue, one pound, break it into small pieces, put it into an earthen pot, and pour on it three pints of cold water; let it stand twenty-four hours, stirring it now and then with a stick; then set it over a slow fire for half an hour, or until all the pieces are perfectly dissolved; skim off the froth from the surface, and strain it through a flannel

for use.

Isinglass and the cuttings of parchment make an elegant size for very particular injections; and those who are not very nice may use the best double size of the shops.

Red.-Size,, one pint-Chinese vermilion, two

ounces.

Green-Size, one pint-levigated crystallized verdigrise, two ounces-best flake white, levigated gamboge, of each eight scruples.

Black.-Size, one pint-lamp-black, one ounce. All injections are to be heated to such a degree as not to destroy the texture of the vessels they are intended to fill: the best criterion of this degree of heat is dipping the finger into the injection. If the the finger can bear the heat, the texture of the vessels will not be hurt.

All the coloured materials should be as finely legivated as possible, before they are mixed with the injection.

Great care should be taken lest the oily ones boil over, or bubble; and that the heat be gentle, otherwise the colour will be altered. They should be constantly stirred, lest the colouring material, which is much heavier than the vehicle, fall to the bottom. The instrument to stir them with should be a wooden pestle, and there should be one for each colour. A large tin pan to contain water, with two or three lesser ones fixed in it for the injections, will be found very useful, and prevent all accidents, and the colour from spoiling when on the fire.

Preparations made with coarse injection. -The blood-vessels are mostly filled with coarse injec tion, and the parts dissected, to shew their course; and when the anatomist wishes to exhibit the mi nuter branches, the fine injec ion is to be thrown in first, and followed by the coarse.

There are several circumstances to be observed in injecting with the fine and coarse injections, which are applicable to every part into which they are thrown; these are the part to be injected should be freed from its blood as much as possible, by steeping it for several hours in warm water, and repeatedly changing it. Having emptied the part of its blood, the pipes are to be fixed in their proligature. The heat of the water is then to be gradually per vessels, and all other vessels to be tied with a tion to be thrown in. The injecting syringe should increased to the same temperature with the injec be steeped in the water with the part to be inject the subject cold, remove the pipes and tie up the ed until wanted. The injection being finished, and parts they were in. Whenever a vessel is open, by accident or otherwise, be sure to secure it by a bladder, or the injection will always be oozing out. ligature, or cover it with a piece of thin and muist The parts dissected and dried are to be varnished free from grease. with some soap-lees, and well twice with copal or hard varnish, first washing them drying then again.

Blood-vessel subject.-Select an emaciated sub

ject, between the age of two and fourteen years. whole length of the sternum: then, with a saw, die Make an incision through the integuments the vide the sternum longitudinally into two equal parts; introduce a dissecting knife under the divid ed bone on each side, separate it from the mediback the two portions of the sternum and the carastinum, and lay open the thorax, by bending tilages of the ribs: an incision is then to be made into the pericardium, and the left ventricle of the heart, and a large pipe introduced into the aorta, and secured by a ligature. The subject is next to be put into warm water, and gradually beated. The time generally required to heat the whole subject is four hours, in a large body of water.

If the veins are to be injected, three more pipes are required: one to be put into the angular vein, at the corner of the orbit; another into a vin as near the fingers as possible; and the third into vein as near to the toes as possible.

The subject and injection being properly heated, throw the coarse red injection into the heart pipe, which will fill the arterial system, and then the coarse yellow injection into the head pipe first, and next into the pipes of the extremities. The subject, when injected, should be put into coll water, with its face downwards.