“9. The preservation of particular organs, such as the heart, the lungs, the eye, &c., differ but little from that of the organs which we have just mentioned; they are always to be either dried, or deposited in an alcohol bath. The lacrymal ways, says M. Breschet in his excellent thesis on the preservation of anatomical subjects (Paris, 1819,) are less easily preserved, although the lacrymal sac, nasal canal, the lacrymal points and conducts, offer more difficulty in their preparation than in their preservation, which may be accomplished by liquors, or by desiccation. The lacrymal canal, and its excretory canals, can only be seen on preparations in spirits of wine. Finally, the following are some passages from the same work, upon the means of preserving the embryon and the fœtal envelopes.
“It is useful to preserve the embryons and fœtuses at different periods of gestation, in order to study the successive development of each organ.
“The egg, considered in its various periods of incubation, can only be preserved in alcohol somewhat weakened, in order that it may not harden the membranes. Kirschwasser, in which has been dissolved the nitrate of alumine, forms a limpid liquor, in which the egg may be preserved without any alteration. In order to demonstrate the development of these organs, many parts may be injected; thus, during the earlier periods, the pedicle of the umbilical vesicle admits mercury, which is introduced by a small glass syringe, the tube of which has been drawn fine in the blow-pipe: this injection ought to be made on the side of the vesicle, and sometimes the metal may be seen passing into the intestines.
“The omphalo-mesenteric vessel ought also to be injected. The urachus should be opened, and its communication with the bladder should be shown on one part, and with the alantois on the other. All these parts are to be kept separate from each other, and attached by means of small pins to a plate of wax. In the fœtus, near the term of gestation, those vessels which establish the communication between it and the mother, are to be injected.
“The bones of the embryon, after having been injected, are to be placed in oil of turpentine, without its being necessary previously to place them in a weakened acid.
“As regards the envelopes of the fœtus, and the placenta which it may be intended to preserve after an accouchment at full term, injections of different colours are forced into the umbilical arteries and veins; this injection should not be too delicate, or pushed with too much force, otherwise it will pass from one of the vessels into the other. These two parts should be allowed to soak some time in an aluminous water, or, what is better, in a sublimated alcoholic solution, then place a hog’s bladder in the cavity of the membranes, blow up the bladder, and thus expose the parts to the air for desiccation; after which the bladder is to be withdrawn. The membranes, with the placenta, may thus be preserved, by placing the uterine face of the latter sometimes within sometimes without the cavity of the membranes. These same parts can be preserved in liquors. Finally, some persons make use of the method of corrosion to prepare and preserve the placenta.”
It is useless to advance here new observations; those which have been already presented on the occasion of preservation, considered in general, are equally applicable to the present. It will be perceived in the following chapter what means I propose to substitute for them, as meriting the preference.