Chapter VII

METHODS OF PREPARING AND PRESERVING SUBJECTS OF ANATOMY, PATHOLOGY, AND NATURAL HISTORY, PREVIOUS TO THE PROCESS OF GANNAL.

Among the investigations belonging to the domain of medicine, normal anatomy and pathological anatomy occupy the first rank; they constitute the necessary basis of exact study: all men of genius have experienced this.

This conviction has been the source of the persevering efforts of numerous distinguished savans, who reasonably supposed that they would merit the esteem and gratitude of their species, if they could succeed in composing collections of engravings, or artificial models, representing the form, colour, &c., of each of the organs, or if they could discover methods of preparation capable of preserving the organs themselves with all the physical properties which they possessed at the moment of death.

It is not necessary to enter into discussions upon the high importance of these different kinds of investigations; for every one comprehends it, and the gravest authorities have pronounced upon this matter. Who does not know the vast importance which our illustrious Cuvier attributed in the progress of the natural sciences, to him who first conceived the idea of preserving objects in alcohol? It is perceptible, indeed, at the first glance, that the most beautiful and valuable of libraries for the physician and naturalist would be a collection of artificial subjects; or still better, of all the organs of the bodies of animals, and of man, skilfully prepared and preserved, without any alteration of the properties which it is important to know.

It must be admitted that a collection in which all the organs would be disposed in series, where they would be seen passing by their successive degrees of increment and decrement, offering their differences, individual and sexual, their points of contact and separation in the various classes of the animal kingdom, their anomalies, their pathological affections, their intimate structure, &c., it must be admitted I say, that such a collection would be an inexhaustible source of knowledge; it would acquire additional value by the addition of a series of pieces representing the detailed anatomy of each of the parts involved in surgical operations.

But this library, so eloquent and instructive, does it exist at the present time? Do we possess the means of forming such? The examination of the various processes, ought to furnish us with an answer to this question; it will besides enable our readers to estimate for themselves the part that our method may enjoy in the accomplishment of this object.

And first, in admitting the utility of _engravings_ of _models in wax_, and in _artificial carton_,[L] in _white wood_, or in other compositions kept secret by their authors, we feel that whatever may be the accuracy of these different representations, they never can afford but an incomplete idea of the thing represented. 1st. _Plates and engravings_, so advantageous for reference, to recall the study made upon the corpse, have lost their importance in proportion as the means of obtaining dead bodies have become more easy: they are calculated to render great service and contribute to the progress of science in the fine anatomical works of Meckel, Lauth, Haller, Zinn, Hunter, Cruikshank, Cowper, Vic-d, Azyr, and of numerous other learned authors; at the present day, even, they are justly esteemed in the great works of MM. Cloquet, Bourgerie, &c. (The plates of the work of M. Bourgerie, are executed with remarkable care, and will form an epoch in the history of anatomical works.) But they occupy a secondary place, only to aid the memory; for of whatever good they may be, they must always have many inconveniences: 1. They fatigue attention, because it is necessary so often to multiply the figures, when it is requisite to examine an object under all its aspects where it is of importance to perceive it; 2. The organs are rarely seen of their natural dimensions; 3. Whatever may be the exactitude of the drawing, it is difficult to form a just idea of the relief and dimension of the organs; 4. The relations which they indicate are always incomplete; it is impossible thus to represent all the organs in their position, and in their natural relations.

[L] A composition of papier maché, with which Dr. Azoux has so
beautifully represented anatomical subjects.--_Tr._

2d. _Models in wax_, nearer to nature than plates, reproduces objects with admirable truth for the eye, but for the eye only. They were recently estimated of such importance, that courses on modelling were introduced into the schools in many cities of France; nevertheless, it cannot be concealed that pieces thus prepared leave much to be desired: 1. The relations of the organs which they indicate are very limited: 2. It is necessary then to multiply them to infinity, if it be desirable to represent under various points of view, the different points of the human body, which is indispensable, in order to comprehend their relations and connections: 3. And still the mind comprehends with difficulty the totality of objects viewed in a great number of pieces: 4. They cannot be handled and displaced as is requisite for study, without injury to them.

3d. _Artificial pieces_, which possess many of the inconveniences of wax models, are more proper to give a knowledge of the parts, which enter into the structure of man; nevertheless, if they be white wood, like the subjects of Fontana, or in Carton, like those of Ameline, or of M. Azoux,[8] they leave much to be learned of the properties which are requisite to an accurate and complete knowledge of the parts. Finally, these three means of communicating knowledge possess their degree of utility, but they can never support a comparison with the proper matter of the organs; they may serve to complete a museum, but never to form one; so we content ourselves to mention them here, in order to assign them a rank.

[8] The subjects prepared by M. Azoux, are however, more proper to facilitate and extend the study of anatomy; they are far superior to dried objects. It is desirable that every amphitheatre should possess one of these subjects.

Anatomical pieces which place before the eyes the organs, themselves, are then the elements, “par excellence,” for the formation of collections, which are to serve as studies of normal anatomy, of pathological anatomy, and of natural history, but, the preparation and preservation of these pieces is a new science; we ought not to be astonished at it, notwithstanding the advanced state of our anatomical knowledge, if we reflect on the difficulties of all kinds, which prejudice excited in our predecessors. It is stated, it is true, that Ruysch, had discovered the means of preserving the dead body, with _all the appearance of life, without drying, with florid complexion, and supple limbs_. But, is this really the fact? and have we not good reasons to doubt such assertions, since no collection of anatomical pieces, prepared by this process, has descended to us, and no explanation has confirmed our knowledge of them?

We may then conclude, that the means of preparing and preserving, does not date much earlier than the commencement of the present century. None of them, however, has had for object the preservation of the entire subject: that which offers us the most numerous parts united in the same preparation has only a reference to anatomy, properly so called; it is the process of M. Swan, of England, given by him as a new method of making dried anatomical preparations, preserving to them the appearance and the advantages of fresh preparations, without possessing the inconveniences of them; this process is, as we shall see, only an application of the discovery of Chaussier, on the preservative properties of the deuto-chloride of mercury. We give it here, before passing in review the methods of preparation practised for each organ or each tissue.

“In order to describe the manner of making these preparations, I shall only take the arm by way of example.

“The member should be selected as clear from fat as possible. A solution of two ounces of oxymuriate of mercury, in half a pint of rectified spirits of wine, must be injected into the arteries, and the day after make another injection with the same quantity of white spirit varnish, to which must be added one-fifth part of turpentine varnish, and a small quantity of vermillion. The limb should next be placed in hot water, and remain there until it is sufficiently heated for a coarse injection into the arteries, and even the veins if necessary. If the veins are to be injected they had better be emptied of blood, with water, before forcing into the arteries the solution of oxymuriate of mercury, because there returns always by the veins some portion of this injection which coagulate the contained blood, and hinders the coarse injection from passing into the smaller branches.

“After the limb has been injected it may be dissected. Every time the work is left, it is better that the parts uncovered, should be enveloped in a linen cloth wet with water; and when the dissection is recommenced a great advantage will be remarked, which is that the parts injected with the solution of the sublimate will suffer very little alteration in several days, and are found in the same state in which they were left, whilst, by the common method, in one or two days, all is so changed that there is little profit in seeing what has been done, and if the dissection is long, they will scarcely be recognised when finished.

“Another advantage is that it may be dissected any where, since the preparation is without odour.

“When all the parts are uncovered, and all the fat and cellular tissue has been removed, the member thus prepared must be put into a solution of two ounces of oxymuriate of mercury, to one pint of rectified spirits of wine, and let remain entirely covered with this for at least fifteen days, for it cannot remain too long. A box of oak, painted white and varnished is the best recipient for the limb, whilst in solution; the cover must fit closely, in order to prevent the evaporation of the spirits of wine.

“The member must be withdrawn every two or three days, and any remaining cellular tissue is to be removed, and when returned to the tub the part which previously touched the bottom must be placed uppermost. The best thing upon which to place the preparation, when withdrawn from the solution, is a butcher’s tray, after having been well oiled; without this precaution the tray imbibes moisture, from which results a great loss of the solution. When the limb has remained long enough in the solution, it is to be taken out, to be painted and varnished.

“Before proceeding to these operations, the member kept in a state of extension, is suspended and dried, then endued with white varnish. On the same day the nerves, the tendons, and tendinous expansions, ought also to be varnished; which must be repeated once a day, for three consecutive days. The fifth day, the tendons, ought to be covered with a layer of yellow varnish, and white paint mixed in equal parts; this operation is to be repeated the seventh, eighth, and ninth day. The nerves, must also be endued, as often as necessary, with a mixture of equal parts of white paint, and white varnish.

“As soon as the muscles have become stiff, they may be painted, taking care that the nerves and tendons, are not touched by the paint. Nearly a month after the limb has been withdrawn from the solution, those of the nerves and tendons that are not sufficiently coloured should be repainted and varnished, as often as may be judged necessary. But always allowing a day’s interval between each application of paint and varnish.

“These operations being finished, wash lightly the tendons and nerves with boiled flax seed oil; this layer being dry, give a second over the whole limb; finally, several layers of copal varnish will terminate the operation. The first layer of copal varnish to be applied to the arteries with a slight addition of vermillion, and of Prussian blue, for the veins.

“In order to preserve the liver, it is necessary first to inject the vena porta and excretory ducts with white varnish, to which has been joined one-fifth of turpentine varnish, and some coloring matter, such as red lead. Then make the coarse injection, after which the liver is to be put into the solution for a least fifteen days; it is not necessary to heat it before injecting. The ligaments are to be prepared in the same manner as the tendons.

“We give below the paints, and varnishes, employed in the preceding preparations:

1.--_White Varnish._

℞. Canada balsam, spirits of turpentine, _a.a._ 3 ℥.
Mastic Varnish. 2 ℥.

Put the whole in a bottle, and agitate until it is perfectly mixed.

2.--_Mastic Varnish._

℞. Powdered mastic. 4 ℥.

Dissolve in a pint of spirits of turpentine.

Agitate daily, until the mastic is dissolved.

3.--_Yellow Varnish._

Infuse one ounce of gum-gutta in powder in eight ounces of spirits of turpentine for fifteen days; then, with equal parts of this clear drawn liquor, Canada balsam, and mastic varnish, form the yellow varnish.

4.--_White Paint._

Three ounces of white lead, and an ounce of spirits of turpentine serves to form it.

5.--_Paint for the muscles._

It is made of Lac, Prussian blue, and white varnish, to which is added one quart of turpentine varnish.

6.--_Red Injection._

℞. Wax, 4 ℥.
Copal varnish, 1/2 ℥.
Red lead, 1/2 ℥.
Vermillion, 1 ʒ.

Melt together.

7.--_Green injection._

℞. Wax, 4 ℥.
Blue dross, 1/2 ℥.
Copal varnish, 1/2 ℥.

8.--_Blue injection._

To form this it is only necessary to add to the green injection, half a drachm of powdered Prussian blue.”

The advantages of such preparations do not answer, in any degree, to the promises of the title; the artificial preparations of M. Azoux are much more preferable, since his cartons represent the form which the anatomical pieces of Swan have lost by desiccation.