“In employing ebullition, we have the advantage of preparing the bones more promptly, and in a manner less insalubrious than by maceration. Nevertheless, this mode of preparation has its inconvenience: 1. Bones which are boiled, become, in general, less white than those which are macerated; the blood coagulating in their pores, leaves a brown tinge, which it is often impossible to remove; 2. They commonly retain a greater quantity of medullary matter, which, by becoming rancid, soon gives them a yellow colour and a very disagreeable odour; 3. Ebullition is not applicable to the bones of young subjects, in which the epiphyses are not yet adherent; it acts upon their gelatinous texture, and despoils, in part, the short bones and the extremities of the long bones of the compact layer which envelopes them. This last inconvenience is manifested even in the bones of adults.
“Dealbation, or bleaching of bones.—In order to obtain macerated bones perfectly white, several processes are employed: 1. The best method consists in placing them upon the grass exposed to the united action of the air, the sun, and the dew, as is practised in bleaching linen, wax, &c.; care is to be taken to turn them every fifteen days, in order that they may bleach equably; two or three months of such exposure is sufficient, particularly during the spring, to give them a brilliant whiteness. 2. The bones may be exposed to the action of chlorine, either liquid or gaseous. In the first case, they are to be plunged three or four times daily in a lie which holds chlorine in solution, repeating this operation for ten or twelve days; in the second, they must be steeped in water, placed on a hurdle and covered with cere-cloth or gummed taffeta, they are then to be exposed over an earthen pan, in which has been placed suitable proportions, of muriate of soda, oxide of manganese, and sulphuric acid: from time to time this mixture is to be slightly heated. 3. In place of gaseous chlorine, the vapour of sulphuric acid may be advantageously employed, as is done in the arts of bleaching wool, silk, &c.; sulphur is slowly burned beneath the hurdle, upon which has been placed the moistened bones; the alkaline lies may also be used for the bleaching of bones although they do not appear to me so advantageous as the preceding means.
“3. Cutaneous tissues.—Deprived of grease, and of subjacent cellular tissue and exposed to the air, this tissue inclines to dry. The human skin may be prepared by the aid of several processes analogous to those of tanners and leather dressers. A lie has been recommended composed of two pounds of common salt, four ounces of sulphate of iron, and eight ounces of alum, melted in three pints of almost boiling water; the skin divested of its grease, is plunged into this solution, agitated for half an hour, and macerated for a day or two in this liquid; the lie must be frequently renewed, then the skin is to be withdrawn from the bath and dried in the shade.
“4. Cellular tissue.—Authors have successively employed desiccation, insufflation, tanning liquors and alcohol, for preparing the cellular tissue; although the method given by them as preferable, is the preservation in an aqueous solution of nitrate of alumine, to which is added a small quantity of spirits of wine.
“5. Synovial and serous tissues.—The first is much more easily preserved than the other; an accurate dissection, expulsion of the synovial liquor, kneading, and desiccation, are the means used; the operation is finished by the application of a preservative varnish. The same practice is applied to the serous tissues, but with less success; its proximity to organs eminently putrescible, such as the brain, the lungs, the liver, renders its dissolution more imminent, more difficult to prevent.
“6. Encephalon, spinal marrow, nerves.—We have already spoken of the property of nitric acid, to give consistency to the nerves, without causing them to lose any thing of their pearly whiteness. Anatomists generally avail themselves, for the preservation of the whole nervous system, of the alcoholic solution of corrosive sublimate. After twenty or thirty days immersion in the bath, these organs are withdrawn and exposed to dry. As communicating a remarkable density to the encephalic mass, a solution of sugar in brandy is much praised: it is a method recommended by Lobstein, chief of the anatomical department of the Faculty of Strasbourg.
“7. Arterial vessels, veins, and lymphatics.—The interesting details which have been furnished to us by the pamphlets of M. Dumèril on the subject of injections, will enable us to dispense with much further developments; the vessels injected and preserved, as we have seen, are dried and preserved in alcoholic liquors.
“When the object is to prepare the vessels of the bones, some care is exacted to render visible their passage through the bony frame; after having filled the vessel with a coloured injection, the piece is to be placed in a diluted mineral acid, which, in dissolving the calcareous phosphate, leaves the vessels in position, and clearly visible through the gelatinous portion of the bone.
“In causing this mucous body to dry slowly and in the shade, it will acquire the necessary transparency to manifest on its cut surface (endued with volatile oil and varnished) the distribution of the vessels which penetrate the bones. These pieces may be preserved in a collection, either in the open air, after having been plunged into an alcoholic solution of arsenical soap, which dries quickly without bleaching; and to which essence varnish adheres very well; or if the piece is small, it may be suspended in a jar of volatile oil, luted with care; in this latter case, the injection must have been made with gelatine, and not with fatty matter.
“8. Muscular tissue.—The process of Swan, or rather the discoveries of Chaussier, furnish the means of preserving the muscles by desiccation. Nevertheless, another method is recommended by authors; after having prepared the vessels and the muscles, the preparation is to be placed in a mixture of alcohol, lavender, and essence of turpentine; it is to be left for several days in this liquor, and then exposed to a warm and dry air; when desiccation is complete, a layer of varnish may be applied.