We shall see to what extent the more recent additions made to
sublimated alcohol, of hydrochlorate of soda, (chloride of sodium,) of
the hydrochlorate of ammonia, of the muriate and nitrate of alumine,
can contribute to the wants of the collector of pathological anatomy.
Before entering into this critical examination, it remains for us to
describe the processes employed by naturalists for preserving the
different species of animals. The excellent manual of M. Boitard, so
useful to preparors, will furnish us with this information.
_Means of preparing and preserving practised by naturalists._--The
soap of Becoeur enjoys with naturalists a great reputation as a
preservative. It is this preservative, then, that we should recommend
as the most approved by experience: the following is the receipt:
℞. Arsenic pulverized, 2 ℔.
Salt of tartar, 12 ℥.
Camphor, 5 ℥.
White soap, 2 ℔.
Powdered lime, 8 ℥.
In the original, four ounces of lime is recommended, and we have given
this dose in our first edition; but it has since been found by doubling
it, the preservative is less pasty, and less difficult to use, more
abundant and equally good.
M. Simon thus composes the preservative, but he adds to it a certain
quantity of corrosive sublimate, and of camphor dissolved in spirits of
wine. The camphor, thus incorporated with the preservative, does not
volatilize so easily as when used in powder.
When used, a sufficient quantity is placed in a small vessel, and, with
the aid of a hair pencil, it is moistened with water and spread upon
the piece to be preserved.
Some naturalists, fearful of the danger of the daily use of arsenic,
have endeavoured to replace this preservative by another composition,
but have never succeeded in obtaining results equally advantageous;
but, nevertheless, in order to render this work as complete as
possible, and to facilitate new researches, we thought that we should
at least, indicate here, the different processes which have by turns
been imagined.
In my cabinet of natural history, I have indicated, under the name of
_soapy pomatum_, the following composition:
℞. White soap, 1 ℔.
Potash, 1/2 ℔.
Powdered alum, 4 ℥.
Common water, 2 ℔.
Oil of petroleum, 4 ℥.
Camphor, 4 ℥.
M. Mouton de Fontenille proposes a tanning liquor thus composed:
℞. Quinquina, 1 ℥.
Grenada bark, 1 ℥.
Oak bark, 1 ℥.
Gentian root, 1 ℥.
Absynthium, 1 ℥.
Tobacco, 1 ℥.
Powdered alum, 1 ℥.
Common water, 2 ℔.
Boil the whole, except the alum, which is not to be added to the liquor
until withdrawn from the fire; it is to be put into a well corked vial
for use.
M. Mouton thus uses his liquor: when an animal is skinned, and the skin
divested of grease as well as possible, the internal surface is to be
moistened with the tanning liquor until it is perfectly impregnated; if
it be a dry skin, it is to be moistened in the same manner until it is
softened.
An author has recommended, under the name of _antiseptic powder_, the
following composition:
℞. Arsenic, 1 ℔.
Calcined alum, 1-1/2 ℔.
Purified sea salt, 1/2 ℔.
The whole to be reduced to a fine powder and well mixed.
We advise that powdered arsenic never be used, because, by
volatilizing, it might penetrate the lungs and cause mortal ravages.[N]
[N] In this country, powdered arsenic is almost exclusively used by
preparors--and is alone sufficient for this purpose--the arsenical
soap is not sufficiently strong; no fatal effects have been known to
follow its use; care should be taken to wash frequently.--_Tr._
The preparor Nicholas recommends, in certain cases, a composition
which ought to be here mentioned, not to advise the use of it, on the
contrary, to advise the rejection of it; for far from driving off the
insects, it attracts them; he calls it _gummy paste_.
℞. Colocynth, 2 ℥.
Gum Arabic, 4 ℥.
Amidon, 6 ℥.
Cotton, hashed fine, 1 ℥.
Other preparors, without passing any thing over the skin, confine
themselves to the use of the following powder:
℞. Calcined alum, 3 ℥.
Flour of sulphur, 1 ℥.
Black pepper, 1/2 ℥.
Powdered tobacco, 1/2 ℥.
Powdered sabine, 1/2 ℥.
Powdered camphor, 3 ʒ.
The whole to be finely powdered and well mixed.
Some amateurs content themselves in passing over the internal surface
of the skin they wish to preserve, a good layer of melted suet mixed
with a small quantity of corrosive sublimate; it appears that they
have obtained some advantageous results, which authorises further
experiments; it has been remarked, that suet is never attacked by
insects; perhaps, if it were combined with some mineral matter less
dangerous than the sublimate, results as satisfactory as those from the
arsenical soap of Becoeur might be obtained.
Such are the preservatives which have been employed in France, but
which do not possess, to any extent, the efficacy of the arsenical soap
of Becoeur. It appears that the Germans employ others to which they
attribute the same qualities, which appears to us very doubtful in all
cases: they may be mentioned here.
Naumann, in the first place, gives a method which appears to us
vicious, although he invokes in its favour his own experience.
After having said that the best method of preserving is to close
hermetically, stuffed animals in boxes, he adds: “I do no more for
skins which are to travel in boxes, than powder them with the following
composition:
“Of lime decomposed in the air, and finely sifted, two parts; of saxony
tobacco, also sifted, one part.”
Hoffman approves of, and recommends the following powder:
℞. Sal ammoniac, 1 ℥.
Calcined alum, 1/2 ℥.
Saxony tobacco, 3 ℥.
Aloes, 1 ʒ.
The librarian of Jena, M. Theodore Thon, proposes the following
powder, as better for preserving animals in the open air.
Cobalt, 1 ℥.
Alum, 2 ℥.
To be powdered and mixed. Before employing this powder, give a layer
of essence of pine, (turpentine,) in order that it may adhere better to
the interior of the skin. If the latter be very greasy, add an ounce
and a half of lime decomposed in the air and sifted.
Among the preservatives which this naturalist has investigated, we
find a very simple one, which he says, is very effectual for mammifera:
the following is its composition:
Cobalt in very fine powder, 4 ℥.
Alum, 4 ℥.
The same naturalist recommends another composition as very good, and
which I think would be worth making a trial of for large animals, which
would be very expensive done with arsenical soap. Very fat bitumen is
to be melted, in a strong solution of soap-water, until the whole forms
a sort of clear broth; the interior of the skin is to be endued with
this mixture, which costs very little.
_Preservatives in Liquors._
Liquors are employed in baths, in lotion, in friction, in injection,
and finally, in permanent baths, in which certain objects are always to
remain; we shall now treat of these four methods of preservation.
_Of the Bath._
In many animals, and particularly in the mammifera, the skin has such
a thickness, such a degree of intensity, that the arsenical soap can
not penetrate it sufficiently in order to preserve it perfectly; it is
then that the bath becomes an indispensable operation. In penetrating
the skin which is left to macerate a longer or shorter time, the
preservative molecules with which it is saturated enters all its pores,
and preserves it for ever from the attacks of insects.
The following is the composition of the bath employed by the
naturalists--preparors of Paris.
℞. Common water, 5 ℔. {pints}
Alum, 1 ℔.
Sea-salt, 1/2 ℔.
This mixture must be boiled until it is all entirely dissolved, and
when the liquor has cooled, plunge the skins into it; those of the size
of a hare, or thereabouts, need not remain longer than twenty-four
hours; those of the larger animals must macerate a longer or shorter
time, according to their thickness; from eight to fifteen days would
not be too long for a buffalo or a zebra. At the museum of Natural
History of Paris, they very rarely make use of this composition; they
are satisfied to macerate the skins in spirits of wine, which they
keep in hogsheads for that purpose. Without attempting to criticise
this method, which may have its advantages, we think that they might,
perhaps, in this particular, follow the English naturalists, and add,
like them, a small quantity of corrosive sublimate dissolved in
spirits of wine.
Nevertheless, as we ought to be impartial, we should mention here the
dangers attendant on the use of this terrible mineral, so much boasted
by Sir S. Smith, president of the Linnean Society of London. When there
is occasion to mount a subject prepared with sublimate, whether it has
been employed in powder or in solution, in arranging the animal there
arises a dust, which penetrates the nostrils, and may cause serious
accidents. Arsenic, though much less energetic, is not even free from
this inconvenience. Thus it is only with much precaution that preparors
should handle preparations in skins which they receive from foreign
countries, the substances used in the preparation of which they are
ignorant.
Let us now pass to the other preservatives in liquor, less generally
employed, at the present time, although some of them may be very
useful. The following is the tanning liquor which I have proposed in
the Cabinet of Natural History:
Tan, or oak bark, 1 ℔.
Powdered alum, 4 ℥.
Common water, 20 ℔.
An ancient author, the Abbe Manesse, composed his bath in the
following manner:
Alum, 1 ℔.
Sea-salt, 2 ℥.
Cream of tartar, 1 ℥.
Common water, 4 ℔.
_Liquors employed externally as lotion._
When an animal has been mounted or prepared, and fears exist less the
insect should attack it, this may be prevented by washing its feathers,
its hairs, or its naked skin, with one of the liquors which we are
about to indicate. Animals exposed to the open air have, above all,
need of being thus treated, and yet, by an inconceivable negligence,
many amateurs permit their collections to be devoured, for the want of
employment of a means both simple and easy.
1. _The essence of wild thyme_, has been recently advantageously
employed; in using it the feathers or hairs of an animal are to be
raised every little distance by a long needle, and at their bases, that
is to say, the skin, is to be touched by means of a hair pencil with a
drop or two of the essence, and when this has been well imbibed, the
hairs or feathers are to be replaced, their extremities, never being in
contact with the liquor, cannot become tarnished.
2. _Essence of turpentine_ has been recommended by almost all authors,
and yet, when made use of it is perceived with astonishment that great
inconveniences result; it never dries upon the feathers, which it
greases and soils in spite of every precaution, the spots spreading and
enlarging like oil; besides this, it forms a species of glue, which
arrests and fixes the dust in such a manner that no subsequent effort
can remove.
3. _Liquor of Sir S. Smith._--This intelligent English naturalist,
president of the Linnean Society of London, having turned his
attention to the preservation of prepared objects, already classed in
collections, has concluded that there cannot be a more efficacious
means employed than the following liquor.
℞. Corrosive sublimate, 2 ʒ.
Camphor, 2 ʒ.
Spirits of wine, 1 ℔. {pint}
In large animals it is applied by means of a sponge, which is passed
at different times over the whole exterior of the animal, until it is
perfectly impregnated, and the liquor has penetrated to the skin. In
small animals a hair pencil is used, and the operation is performed in
the same manner. Whether the individual submitted to this practice be
recently prepared, or whether it has long remained in a collection, it
must be permitted to dry perfectly before placing it in a cabinet.
In France this dangerous composition is replaced by the preservative
in very small quantities diluted with water.
4. _The bitter spirituous liquor_, recommended by other authors, is
thus composed:
℞. White soap, 1 ℥.
Camphor, 2 ℥.
Colocynth, 2 ℥.
Spirits of wine, 2 ℔.
The whole is to be subjected to cold infusion for several days in a
vessel hermetically sealed, frequently shaking the vessel during this
interval, and allowed to strain through unglazed gray paper; when it is
thought that the infusion is done, it must be put into bottles equally
well corked, and used after the same manner as the preceding.
5. _Varnish_ is employed only on the naked skin of reptiles and
fishes, to which it restores a portion of its splendour; it must be
absolutely colourless, and perfectly transparent. In order to obtain
it thus, it must be prepared by dissolving fine and new turpentine in
spirits of wine, which must themselves possess the qualities above
mentioned. It is to be applied with a pencil of squirrel’s tail, or the
tail of a martin, and the object is left exposed to the air, sheltered
from the dust, if it be wished to hasten its desiccation.
_Liquors employed in Injections._
Injections are more generally employed for the preparation of the eggs
of birds, for which it is desirable to secure a long preservation;
although by a very bad method, they have also been used for the
desiccation of very small animals.
In order to decompose the flesh of a fœtus already formed in an egg,
recourse is had to a strong solution of a fixed alkali, of soda, of
tartar, or to ether.
_Liquors, in which objects are preserved which do not admit of drying._
The qualities which a liquor ought to possess, in which objects of
natural history are placed, are, independently of that of preserving
from decomposition: 1. to be colourless, that they may not tarnish the
contained objects; 2. not to attack by corrosion the proper colours of
the object; 3. to be perfectly transparent, that the contained objects
may be visible through the vase which encloses them; 4. the power to
resist frost, in order that they may not break the jar which holds
them.
1. Spirits of wine, of from fourteen to eighteen degrees of the
areometer of Baume, appears to be the liquor which best fulfils all
these conditions; the other alcohols, such as those from potato,
from grain, from sugar, &c., have the same qualities; but a serious
inconvenience is the high price of all of them, and this reason alone
is an inducement to look for other compound liquors, capable of
replacing them with more or less advantage.
2. Nicholas recommends the following composition:
Very pure water, 2 ℔. {pints}
Alcohol, 1 ℔. {pint}
Sulphate of alumine, 6 ℥.
The English naturalist, George Graves, in a work published in London,
seven years ago, indicates a liquor which has much analogy with the
preceding:
Alum, 8 ℥.
Common water, 1 ℔. {pint}
Alcohol, 1/2 ℔. {1/4 pint}
The following is the method of preparing this mixture: the alum is
pulverised and put into a vessel capable of resisting heat; water
being heated to ebullition is poured upon the alum; when cool, it is
to be filtered through gray paper, and then mixed with alcohol. The
same author recommends another liquor, thus composed, but of which the
mixture is made cold.
Common water, 1 ℔. {pint}
Alcohol, 1 ℔. {pint}
Alum, 12 ℥.
4. The Abbe Manesse, after various trials, more or less successful,
has published the result of his experiments; he proposes as the best
liquor, one composed as follows:
Alum, 1 ℔.
Nitre, 1 ℔.
Sea salt, 1 ℔.
Common water, 4 ℔. {pints}
Alcohol, 1 ℔. {pint}
The water used should be distilled, so as to be freed of any foreign
matter; the alum should be the most transparent that could be obtained,
and the salt also should be purified before use. The liquor may be made
cold, but it is always better to boil it, with the precaution not to
add the spirits of wine until it has cooled.
All these liquors are inferior to spirits of wine, inasmuch as they
are liable to freeze.
After having given this long list of the known means of preserving, and
given in detail the representation of authors, it remains for us to
judge of them, to determine their merit, and the degree of confidence
that ought to be accorded to each, under the triple point of view of
the preservation of objects of _normal anatomy_, of _pathological
anatomy_, and of _natural history_.
1. _Process of desiccation._--It can be of no utility for pathological
anatomy, because it changes entirely the aspect and texture of parts,
and in most cases it leaves no traces of the alterations which it
is important to know. For normal anatomy, these preparations are,
and always must be, from the simple fact of desiccation, a feeble
resource, and really much inferior to the artificial subjects of M.
Azoux; for this ingenious preparation, if it has many of the faults
of dry anatomy, the objects are not so deformed as scarcely to be
recognised.
Further, each of the preparations which tend to desiccation has
its particular inconvenience: thus those of the deuto-chloride are
numerous, as we have seen in the preceding chapter, and as have
remarked in this the authors whom we have cited. We may add that the
salts of mercury, of copper, and of lead, which, in combining with
gelatine, form, it is true, an inalterable compound, have a great
affinity for hydrosulphuric acid, and that there results from this
affinity, a necessary deterioration of the objects, colouring them
black. Sea salt does not possess durable preservative properties; and
its affinity for water even facilitates the decomposition of the dried
subjects which contain it. Alcohol is, doubtless, a good means, but
it requires to be frequently renewed, until by its affinity for water
it absorbs all which the organs contain; but alcohol costs _forty
cents a quart, and loses always by evaporation_. Besides, parts thus
prepared, are not less deformed than other dried parts, when subjected
to desiccation.
The naturalist finds in the soap of Becoeur, in other preparations
containing arsenic, the deuto-chloride of mercury, alum, &c.,
sufficiently good means of drying or of tanning the skin and other
animal tissues. But, as M. Boitard has remarked, these preparations are
not without their inconveniences.
What have I to offer the anatomist who believes in the utility of dried
preparations, to the naturalist whom a real necessity often forces to
recur to them? My liquid, employed as a bath or injection, without
either danger or inconvenience, and _which costs only two or four cents
the quart_.
I shall give here an example of injection; a corpse is injected by
the carotid with from five to seven quarts of the acetate of alumine
at 20°, and containing in solution about two ounces (fifty grammes)
of arsenic acid. Four days after this injection, if it is intended to
prepare the large and small vessels, inject by the aorta half a quart
of a mixture, equal parts, of the essence of turpentine and essence of
varnish; finally, make a single cast of a hot injection of a mixture
of suet and of rosin, in equal parts, coloured with cinabar for the
arteries, and with a black or blue colour for the veins. Then, the
corpse, or the part of the corpse which it is intended to preserve,
is prepared and dissected at leisure, according to the wish of the
operator.
When the body has been injected, as above described, the preparation
which is made of it easily dries in the open air from the month of
May to the month of October; during the winter it is necessary to
deposit it in an oven, or in a heated chamber. When the desiccation is
slow, or the moisture is excessive, the byssus sometimes develops on
its surface, but this may be washed off, and a layer of varnish will
prevent new vegetations. This preparation will be certainly superior to
any contained in cabinets of anatomy.
In support of this assertion, I will cite an authentic fact, that of a
woman whose body was submitted to the examination of the commissioners
of the Institute and of the Royal Academy of Medicine, appointed to
prove the value of my process.
On the 10th of May, 1834, a woman died in the wards of M. Majendie, at
the Hotel-Dieu; the body was injected the next day with the acetate
of alumine; at the termination of this operation, it remained fresh
until the 15th of January, 1835, when it dried without experiencing any
alteration. The commissioners of the two Academies made experiments
upon this body, at different periods. On the 15th of January, 1836,
M. Gueneau de Mussy, to assure himself of the state of the cerebral
substance, demanded the head to be opened, I profited by this occasion
to _take off the hairy scalp_. The same day, M. Breschet, desiring to
know what would result from the exposure of this corpse to the open
air, it was suspended beneath the shed of the dissecting rooms (ecole
pratique.)
Ten months after, in the month of November of the same year, it had not
experienced any alteration. At this period, M. Gaucherant, inspecting
overseer of the ecole pratique, wishing to terminate the experiment,
the body was sent to the cemetery.
_The right arm and forearm_, the only parts remaining untouched,
after the experiments of MM. the commissioners, were _amputated by
myself_. I preserve this piece, as well as the hairy scalp; I can show
them to anatomists to be compared with all the preparations obtained
by other processes; none of them, I am convinced will be pronounced
comparable to mine. The hairs remain so firmly attached to the scalp,
that a strong pull will not detach them; I am quite sure that the
injection has penetrated even to the capillary tubes of these organs;
my experiments upon cats, dogs, and birds, have demonstrated the
penetration of my liquid into the horny organs, hairs, or feathers,
which clothe the skin of these animals. These facts will demonstrate
all the services which it is capable of rendering naturalists. Finally,
no process of tanning could give to the internal surface of the skin
an aspect more satisfactory than that which offer other preparations
deposited in my cabinet.
2. _Preservation in liquids._--The different preservative liquids
produce effects very different from the process of desiccation;
however, all those employed up to the present day, possess serious
inconveniences, as any one may be convinced by reading the very
commendable passages which we have extracted from the pamphlet of M.
Dumeril. We shall point out some others which he has omitted.
(_a._) _Nitric Acid_, the only one of all the acids, that can be of any
use to the anatomists, preserves well, it is true, the preparation of
the nerves, hardening their structure, and increasing their nacreous
white colour; but it deteriorates all the other structures, it
dissolves the gelatine, softens the muscles, and deprives the bones of
their calcareous salts; it cannot be other than deleterious to objects
of pathological anatomy, and natural history.
(_b._) _Alcohol_, is more serviceable than any other liquor in use, but
its high price renders its employment almost impossible for objects of
normal anatomy; it hardens and sensibly alters objects of pathological
anatomy; and these alterations, however trifling they may be, and
unimportant to regular anatomy, are serious for the physician, who
cannot have too exact an idea of the progress of disorganization in the
living tissues. If alcohol is eminently useful for natural history, its
costliness renders it impossible to extend the use of it as far as the
interest of science demands.
(_c._) _Diluted Alcohol_, to which is added the deuto-chloride of
mercury, is a less expensive liquor; it preserves accurately enough the
labours of the naturalist and anatomist, but it is not sufficiently
faithful for a pathological anatomy. The same may be said of the
hydro-chlorate of soda, the hydro-chlorate of ammonia, the muriate and
nitrate of alumine added to alcohol.
(_d._) _Alum_, which we have seen figure in many of the adopted
formulæ, is, nevertheless an unprofitable means of preservation.
Extensively used in commerce, and employed from time immemorial in
dyeing, it has only recently attracted the attention of preparers. This
salt, to which the new chemical nomenclature has successively assigned
the names of _double sulphate_, _triple sulphate_, _acid sulphate of
alumine and potash_; has been experimented upon by myself, and has
not answered my expectations. I have investigated the cause of this
failure, and think I have found it; in analysing this compound, for
every hundred parts I have obtained
Sulphate of alumine, 36.85
Sulphate of potash, 18.15
Water, 45
----
100
One hundred parts of this salt contains 10.86 of alumine. At the
temperature of 12° centigrade, five hundred grammes of water dissolves
thirty grammes of salt, from whence it results that a pound of water
contains in solution only eighteen grains of alumine; from whence I
have suspected that the little efficacy of alum for the preservation
of animal matter, depends on the too small quantity of alumine in the
solution. A fact convinced me that I was right: twenty-four hours
after the immersion of a corpse in a bath containing the acid sulphate
of alumine, I have observed that all the alumine was absorbed by the
animal matter. Finally, the experiments which I have tried with the
salts of alum, more rich in alumine, and more soluble in water, and
the happy results I have attained, authorizes me to say: alum is a bad
means of preservation, _because it is not sufficiently soluble, and
does not contain enough alumine_. The reader will naturally again recur
to the subject when we come to the exposition of my researches.
SECT. 3.--_Means of preservation applied to each tissue._
In our first paragraph, we have passed in review the different
preparations which ought to precede the application of preservative
means; in the second, we have seen these numerous means, and we were
compelled to deliver an impartial judgment. It remains for us to
explain here how anatomists have applied them to the tissues taken
separately. We shall abstain from relating the preparations which
precede the application of preservative means, because they are
foreign to the subject which occupies us, and would uselessly prolong a
discussion already too much extended.
1. _Fibrous tissues._--_Articulations, aponeuroses, tendons, and
ligaments._--The process generally adopted is due to M. J. Cloquet, in
nearly following the method employed by the tanner, he has succeeded in
preserving the suppleness of these tissues.
“The following,” continues he, “is the process which I have adopted.
“Dissolve four pounds of muriate of soda and a pound of alum in ten
pints of water: the articulation, which has been carefully dissected,
must be allowed to macerate fifteen or twenty days in this lie; paying
attention to move it frequently in the solution, to press and twist
its ligaments, and, above all, to strike it lightly with a little mace
of light wood. These manœuvres are intended to render them pliable, to
separate the fibres, which permits the salts to penetrate more easily.
Withdraw the articulation from the solution, dry it for four or five
days, taking care to move it occasionally, and still to strike it with
the little mace; then put the articulation into a very concentrated
solution of soap, (a pound to three pints of water,) handle, and strike
it again for seven or eight days, the time necessary for divesting it
of salt, and permitting the soap to penetrate the ligamentous fibres,
to take the place of the salts. At the end of this time, that is to
say, thirty-six or forty days after the commencement of the operation,
wash the articulation in a weak lie of carbonate of soda, (an ounce to
two pounds of water,) after which it is to be dried.
“By this process, which may be modified in various ways, ligament
may be obtained perfectly supple, of a yellowish or grayish colour,
resembling chamois leather, very resisting, and permitting the joints
to execute their ordinary movements.
“I have prepared, in this manner, the articulations of the shoulder, of
the knee, of the fingers, and of the vertebral column. I repeated my
experiments with the intention of obtaining a more expeditious method.
“The articulations may also be preserved perfectly supple, by keeping
them immersed in a mixture of equal parts of olive oil and essence of
turpentine.
“2. _Osseous tissue._--The different preparations to which bones are
subjected in order to preserve them, are maceration or ebullition, and
then bleaching.
“_Maceration._--When it is desired to obtain the bones very white,
it is necessary to choose, as far as possible, a thin or infiltrated
corpse, of an individual of from thirty to forty-five years, or
thereabouts, dead of some chronic disease which has not altered the
structure of the bones. Consumptive bodies are the most proper for
this kind of preparation. The subject being chosen, it is roughly
stripped of its muscles and periosteum; the sternum is to be detached
by dividing the costal cartilages where they join the ribs; the members
are to be separated from the trunk, in order that these various parts
may be more conveniently placed in a trough, which is to be filled with
water, and disposed in some place where the putrid emanations cannot
produce any inconvenience; the bones must be constantly kept covered
with water, which must be renewed every four or five days in the
commencement, and at more prolonged intervals towards the end of the
maceration.
“The anatomist should watch over these macerations; and it is only
when all the fibrous parts separate easily from the bones, or the
inter-vertebral fibro-cartilages, and the yellow ligaments separate
readily from the vertebra, that the skeleton should be withdrawn from
the bath and cleaned. For this purpose, he collects with care all the
pieces, and places them in clean water; he cleans them by removing with
a scalpel the fibrous parts which may yet adhere, and by rubbing them
under water with a very coarse brush; he then places them on coarse
linen to dry them.
“_Ebullition._--Boiling water is often resorted to for preparing the
bones of the skeleton. After having roughly separated them from the
soft parts, they are placed in a kettle of water, and subjected to
ebullition for six or ten hours, according to the subject. The action
of the water is increased, and the fibrous parts more accurately
stripped from the bones, as well as the grease, by placing in the
kettle, an hour before the end of the operation, potash, or soda of
commerce, (sub-carbonate of potash, and of soda,) one pound to eighty
or a hundred pints of liquid. After having carefully removed the
grease which swims on the surface of the water, the bones are to be
withdrawn and plunged into a new alkaline lie, warm and very weak;
clean them with care, as in the preceding case, separating exactly
from the articular surfaces, the swollen and softened cartilages, which
remain adhering to them: the bones being clean, they are to be washed
frequently previously to drying.
“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. Dumeril 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.
“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. |
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