Text from Directions for making anatomical preparations: formed on the basis of Pole, Marjolin and Breschet, and including the new method of Mr. Swan (1831) by Usher Pole.
That a minute knowledge of anatomy is essential to success in the practice of physic and surgery, is an opinion so generally prevalent, that the assertion of it at the present day wears the air of a truism. Every student reads the remark in his books, hears it from his lecturer, sees its force in the clinical rounds of his instructor, and feels it when he commences practice. And if the young practitioner feels the want of anatomical knowledge when he has recently left the dissecting table and the halls of demonstration, how much more sensible must he be of it, after years have elapsed, without affording him an opportunity to refresh his memory by lectures or dissections. To obviate this inconvenience, various modes have been employed for preserving the different organs and textures, in a humid or dry state, to which the practitioner may refer as a substitute for recent dissection and demonstration; with this aim in view, the art of making anatomical preparations has been cultivated with great success and advantage.
The art is of modern invention. Injecting and preparing of the blood vessels certainly could not have been known prior to the discovery of the circulation of the blood, nor have we any description of arterial preparations until the time of Ruysch, a professor of anatomy who died in 1731. His first anatomical museum was sold to Peter the Great, in 1717, and many specimens belonging to it, as well as a great number made subsequently, are still in a good state of preservation. His manner of preparing wet specimens,—of injecting the blood vessels, and of preserving the flexibility of dried preparations, although he professed to have disclosed it, is supposed to have perished with him, since no one has yet succeeded in imitations that can be compared with those made by himself.
Still however the common process for making and preserving injected preparations bears the name of Ruysch, and to this process many additions and improvements have been made by Dumeril, Breschet, Hunter, Pole, Marjolin, Charles Bell, Cloquet, Swan and some others, besides several valuable treatises on the art of injecting the lymphatics, and numerous facts and observations, are contained in periodical publications. The substance of the following sheets, is principally drawn from the above writers, but chiefly from Pole, to which are added, such facts as I could glean from some of the best practical anatomists of this country, and such observations as I have been able to collect during a year passed in the medical schools of Europe, and several years devoted to practical anatomy in this country.
That a work like the present is wanted, appears evident from the fact, that several teachers of anatomy have contemplated publishing an edition of Pole, notwithstanding its numerous imperfections. I should however not have commenced the present work, had that of Pole been in circulation in this country. The few copies to be found are imported, and I have several times been at pains to order copies for my friends from London.
Such a work will, I am confident, be acceptable to students from the country, as by following its directions, they will be able to preserve the dissections made at medical schools, as memorials of their industry, and for reference in their future practice. Even in cities, where subjects are easily obtained and dissected, and where public demonstrations are frequent, a student feels reluctant to destroy a fine piece of dissection that has cost him long protracted labour and pains to finish, although he may expect to derive but little advantage from its preservation; but in the country, where such specimens are the best, if not the only means he can enjoy for refreshing his memory, they possess a real and practical value; for, with the exception of Massachusetts, whose legislature has nobly raised its voice in favour of practical anatomy, prejudice and legal impediments it is to be feared will long exist against its prosecution throughout the union, and especially in our country towns.
SEASON FOR DISSECTING AND FOR MAKING DRY PREPARATIONS.
The extremes of heat and cold are unfavourable for dissections and making preparations, heat being the season for insects and rapid putrefaction, and* cold congeals the subject, the subsequent thawing of which is attended with loss of time, hastens decomposition, and always impairs the beauty of the preparations. But the objections to midwinter are removed where the accommodations are such as to moderate the intensity of cold. The late autumnal and early spring months are, however, decidedly preferable for long continued dissections; and it is well known to those who are conversant with the business, that for preserving subjects from decomposition, spring at the same temperature, is more favorable than autumn. These remarks however, refer to preparations requiring long and patient dissection; for other kinds, as macerated and corroded, the summer season may be even preferable.
DISEASES OCCASIONED BY DISSECTIONS.
Besides the diseases that may proceed from contagious affections of dead bodies and which every anatomist will know how to avoid, there are two pertaining to a dissecting room that require some notice. One of them is derangement of the stomach, sometimes attended with fever, and which is probably occasioned by putrid inhalations, perhaps by errors in diet and long exposure to cold, and is more common to ardent beginners; the other is extensive and severe inflammation from slight wounds of the fingers, and absorption of poison from the subject. B
The former affection may be prevented, first, by proper attention to diet, never visiting nor remaining in the dissecting room with an empty stomach ; by nutritious well seasoned food and considerable exercise of the body in the open air, and by obviating a costive habit. Secondly, by attention to the air of the room both as respects temperature and cleanliness. The large cavities of a subject when cleared of their viscera may be sponged with clean water and sprinkled with chlorate of lime and the room freely ventilated.—When the emanations are very putrid and offensive, they may be entirely removed by a fumigating mixture like the following:
.Black oxide of manganese and common salt pulverised, equal parts, by weight, to which add sulphuric acid, diluted with three parts of water in a leaden or earthen vessel. Close the dissecting room, leaving the mixture in the centre of it in the evening, and by morning, the putrid smell will be entirely removed.
Attention should also be paid to cleanliness of person. An apron with sleeves to it, made of shalloon, or brown linen, may be worn, and when this is wanting, a suitable coat to put on and off on entering and leaving the room may be substituted.
When the symptoms of gastric disturbance which I have mentioned appear, the dissection should be suspended, for a day or two, and an active cathartic administered.
The other affection arising from wounds of the fingers is of a more serious character. Chambar, Percy, Duncan, and Shaw, have each written treatises of some length on such wounds, from which I shall draw such facts as are most material to be known. The effects of such wounds, Mr. Duncan and Mr. Shaw, think, may be classed under two heads, forming cases which differ essentially from each other. The one is attended with immediate danger, and is generally the consequence of examining a body a few hours after death ; and proceeds with more certainty, from dissection of the bodies of persons who have died with inflammation of some of the serous membranes. The other cases are more frequent, and less dangerous, and they occur more in common dissections, and particularly, in preparing bones or ligaments after long maceration. The symptoms attending this last kind of wound are the following :—the finger being scratched or pricked in the morning; there is not much pain at the time, but it gradually increases towards evening; a little uneasiness is felt in the axilla, and next morning red lines can be perceived running up the arm. The finger is now excessively painful; there are often slight rigors, and general uneasiness ; the countenance is anxious, tongue sometimes furred, and head-ache; but there is not much fever. The finger then becomes rapidly swollen and livid, so as to call for immediate attention, and the general system still more and more affected.
In respect to the first, or malignant kind, which is more likely to occur from examining a body that has died from peritonitis, in the form of hernia and puerperal fever; or from pleurisy, there will, in five or six hours after receiving a scratch or puncture be a small pimple, or a blush of red. If the case proceeds in the usual manner, there will probably be a darting pain up the arm, which seems to fix more particularly in the shoulder or side of the chest. Within fourteen hours, the patient is very ill; he suffers a great deal of pain, and is anxious and alarmed. Red lines may generally be perceived running from the hand towards the axilla, but it sometimes happens that there are no marks on the arm, nor even on the finger. Indeed, the affection of the finger is occasionally so slight, "that it is neglected, and the patient refers all his suffering to the shoulder and chest. Vessications often appear, and the case may end in desquamation of the cuticle, or in suppuration with extensive sloughing, and a discharge of fetid matter, and in many instances, it proves fatal."
The local treatment of both kinds of the above mentioned wounds, should be the same, at the moment they are inflicted. It consists in applying to the wound a drop of strong mineral acid or of caustic ;—the French prefer liquid muriate of antimony. But after this has been neglected, and absorption has taken place, indicated by pain, &c. such applications will be of no avail, and may aggravate inflammation. The best applications will then be of the soothing kind. Mr. Shaw recommends lint soaked in equal parts of Goulard's extract and laudanum, applied round the finger and along the arm. Emolient cataplasms are also recommended, but their weight gives pain and uneasiness. The French recommend leeches to the part.
According to the same authors, the general treatment should be active aperients, such as rhubarb and jalap, with a little calomel, and to keep the patient at first almost in a state of intoxication, by laudanum and porter. Bleeding, although the pulse be much accelerated, he condemns.
Should any abrasion or sore previously exist on the fingers of the dissector, the utmost care should be taken to shield it from the contact of the dead body, by proper dressing and a slip of bladder bound over it.
CHOICE OF SUBJECTS.
This must, of course, vary according to the kind of preparation intended to be made. For a perfect skeleton, the subject should be near, or a little passed, middle age, for if younger, the bones are not so fully developed, and in old age they contain oil, which is constantly appearing upon their surface. For exhibiting osteogeny, choose the bones of a foetus; and for showing the vascularity of bones with minute injection, the bones of a young child are preferable ;—To make a preparation of the bones of the head separately, choose the bones of a young subject, before the age of puberty, and for the ossiculae of the ear, a child from birth to one or two years. The tympanum should here be preserved on one side, and partially removed on the other, taking care to preserve its centre, where the maleus is attached. For exhibiting the labyrinth by filing into the petrous portion, the temporal bone of an adult will be best. For exhibiting the deciduous and permanent teeth, choose the head of a child from five to eight years old, and file away the alveolar covering of the front teeth.
To dissect and study the muscles, choose a robust, full grown subject that has died suddenly, and a male in preference to a female. For making dry preparations of the muscles, take a subject of a strong muscular frame, whose death was occasioned by a short, but not putrid disease. Great corpulency, as well as great leanness, and dropsical subjects, are for obvious reasons unsuitable.
For dissecting and studying the arteries and veins, choose an adult that is neither very plethoric nor very lean. For making a dry preparation of the blood-vessels of an entire body, an emaciated subject, from two to fourteen years is preferable, as being more easily dissected and dried, and more conveniently handled, and less likely to become greasy after it is varnished :—For a head or extremities, an adult not much beyond middle age, as after this period there will be a constant issuing of fat upon the surface, that will mar the beauty of the preparation; but as the veins are more developed in advanced age, such subjects are best for shewing them upon the head. For minute injection, a full grown foetus is best, and may at the same time serve for exhibiting the foetal circulation, and for making many handsome preparations, to be hereafter described.
For a wet or dry preparation of the cerebral nerves, choose an adult emaciated subject, of almost any age;— but for the whole nervous system, a small emaciated subject, as it can be more conveniently preserved in spirit.
For the lymphatics choose a full grown dropsical subject.
Whatever be the kind of subject that has fallen into the hands of the student, and whatever may be his purpose as to its final destination, he should first perform such little operations upon it, as can be done without injuring it for injecting, and which he may be desirous of performing with dexterity upon the living body; such as introducing the catheter and probing ;—passing a fine wire into the puncta lachrymalia, and introducing a probe from the lachrymal sack through the nasal duct;—pinching up the tunica conjunctiva with a pair of small forceps and clipping it with scissors, as is often required for severe opthalmia. After the subject is injected, he may take up the various arteries, as the carotid, subclavian, axillary, external iliac, and those of the extremities. He may also operate for hare-lip, perform bronchotomy, &c.
ORDER OF EXAMINATION OF THE LARGE CAVITIES.
The tendency of the brain and other viscera of the large cavities to rapid putrefaction, requires their early removal. The brain mollifies so soon, that if the student intends examining it minutely, or to make a wet preparation of it, no time is to be lost by delaying the undertaking.
The next organs to be examined and removed, are, the abdominal viscera, as their presence hastens decomposition. For this purpose make a crucial incision from the sternum to the pubis, and cross it with another near the umbilicus. In this way the viscera are more easily examined and removed, but the abdominal muscles are in some measure destroyed for dissection. Such however is the intricacy of this piece of dissection, that the student will hardly undertake it at first; and the parts most interesting to the surgical pupil, as the abdominal ring and surrounding ligaments, are uninjured by it. The viscera are to be examined in their natural situation, and then after passing a ligature round the O3sophagus below the diaphragm, and round the rectum, they are to be removed, by dividing the suspensory ligament of the liver, turning it down from the diaphragm, dividing the oesophagus above the ligature, and raising the stomach, spleen and pancreas, leaving the branches of the coeliac and mesenteric arteries as long as practicable. The viscera may be subsequently examined, and made into separate preparations, as hereafter directed.
The chest, it is presumed, has already been opened for the purpose of injecting the subject, if not, proceed as directed for injecting the arteries, and remove such organs as are intended not to be preserved in connexion with the walls of the thorax.
The contents of the pelvis are to be removed, by dissecting the kidneys and passing them downward, or, by dividing the ureters, and dissecting round the several organs down to the sphincter ani. But if it is intended to preserve these organs in connexion with the pelvis ; the rectum is to be cleared and stuffed with curled hair, or oiled wool.
The subject may now be dissected entire, or it may be divided among a class of four or five persons.
Before he commences dissections, the student is presumed to be well acquainted with the skeleton. He is to begin his work by making an incision through the integuments, down to the muscles of each limb, commencing it near the trunk and extending it along in the direction of the large muscles. The limb or part dissected should be so placed as to keep the fibres of the muscles in a state of gentle extension. The integuments are to be raised from the muscles, by drawing them aside, and laying the edge of the knife obliquely upon and in direction of the fibres, in order that all cellular substance may be removed without dividing them. The knife may be held in the fingers like a pen, and moved by them, rather than with the wrist or arm. After removing the integuments over muscles, all the cellular substance between them is to be dissected out, taking care not to divide the large nerves or blood-vessels, or such of their branches as are interesting in surgery. When the superficial layer of muscles is fairly cleared of adipose substance, they may be raised or turned aside with hooks, or divided in the middle and turned back, for the purpose of exposing the deep-seated ones for dissection. The integuments ,are to be raised from the muscles no farther at a time than is necessary for the present dissection, and should afterwards be replaced upon the part, to keep it from drying and to protect it from dust; and in warm weather the whole should be covered during the interim of dissection with a wet cloth, to keep it cool by evaporation.
It should be the object of the student to examine the muscles separately and in classes, according to their respective offices; to study their situation and direction with respect to the arteries and nerves, and other parts that are concerned in surgery. If not intended to be preserved, the muscles may after full dissection be removed, and the ligaments and structure of the joints examined, before the bones are immersed for maceration.
The student will hardly find it advantageous to make dry preparations of the muscles alone. They require as much attention, and are attended with as great expense, as when prepared with the blood-vessels, and unless he adopts the method of Mr. Swan hereafter described they will change in colour and size so much by drying, as to represent a recent dissection less satisfactorily than good plates.
COMPARATIVE VALUE OF COLD AND WARM INJECTION.
The comparative value of the two kinds of injection depends somewhat upon the kind of preparation intended to be made. For corroded preparations the cold injection is entirely unsuitable. For wet preparations it is immaterial which kind is used, excepting that the warm kind is attended with loss of time and expense. For common dissections, the cold injection is in most respects preferable, not only on account of the trouble and expense saved in heating the subject, and its not heating and crisping the aorta to the risk of its strength, but also for its withstanding the greatest heat of summer, when the warm kind is apt to liquefy and ooze out from the orifices of divided branches. There is, however, a greater smoothness of the vessels that have been filled with the warm kind, which is pleasing to the eye of an anatomist. In respect to fineness, they will, either of them, if properly conducted, answer every purpose for surgical reference, though beyond this, I have found the cold injection succeed better than the warm, especially for filling vessels of the hollow organs, and of the membranes of the large cavities. Therefore as respects utility and convenience I should, except for corroded preparations, prefer the cold injection.