means of the spray apparatus being first described in the JOURNAL for

1866.

The tissue which is to be cut is placed on the brass plate closing the end of the tube of the condensing chamber. I have found an advantage in using a drop or two of gum water, or, better still, the fluid recommended by Rutherford as an embedding substance in his freezing microtome. It consists of gum arabic five ounces, water nine ounces, and spirits of camphor two fluid ounces, the camphor making the mixture when frozen less brittle, and keeping it about the consistence of cheese. The advantage of using the gum solution is that the tissue is made to adhere better to the smooth brass, and is not so liable to be broken off from it when making the section should the tissue become too much frozen.

The section knife can be kept cold by placing it on a block of ice or by directing the spray from the atomizer upon it for a moment or two. It is necessary that the blade should be cold when making sections in summer or in a very warm room, because the sections melt very rapidly and become rolled into a mass difficult to unfold. During the winter, even in the warmed laboratory, I have not found it necessary to use ice for this purpose, and only rarely do I cool the blade with the spray.

As the sections are cut I transfer them from the blade of the knife, or from the brass plate where they fall, to small cups containing an appropriate solution, by means of a needle mounted in a holder. Usually the sections as cut roll up in small rolls; the thinner the section the closer is the roll. With some tissues the rolls are with difficulty unfolded, but by passing the needle through the centre or hollow axis of the roll, then transferring it to the solution in the cup by gentle manipulation, the thin section uncoils and floats out smoothly. Frequently air bubbles become entangled in the roll when dropped into the solution, and cause the section to float; as soon, however, as the uncoiling is effected the tissue sinks. Many tissues, however, and especially those which have been previously slightly hardened by reagents, unfold themselves as soon as they are placed in the cup, and require no further manipulation.

The sections obtained by this means can be made of the greatest thinness and perfectly even; their areas are limited only by the size of the brass plate closing the tube of the condensing chamber. The instruments as now made by Mr. William H. Walmsley, the manager for R. and J. Beck, in Philadelphia, have brass plates either one inch or one and a half inches in diameter.1

1 Mr. Walmsley has been very kind in carrying out my suggestions in making this instrument (perfect, as I believe it to be) as modified from the one used at the West Riding Asylum, England, and described by Mr. Bevan Lewis in the Journal of Anatomy and Phys iology. Mr. Walmsley, 921 Chestnut Street, Philadelphia, has kindly furnished the cut for

illustration.

The majority of sections that I have made with the instrument are of fresh tissues, but I find a great convenience in the use of it for cutting tissues which have been partly or completely hardened, whether by aqueous solutions or alcoholic. When alcohol has been the harden-. ing agent it is necessary to remove it by soaking the tissue in water for a short time before the specimen can be frozen. If the tissue is thoroughly hardened it is necessary merely to freeze it fast to the plate, which can be done almost instantly. I have found very great advantage from the use of the instrument in making sections of membranous tissues, such as the intestine, an arterial or venous wall, or a thickened pleura, or the peritoneum, tissues ordinarily very difficult to embed. To get vertical sections of these tissues I first spread out a drop of the gum solution on the brass plate, then with two needles or pair of forceps hold the membrane so that its edge just touches the plate; in an instant the spray directed into the aperture of the tube freezes the gum solution and fixes the tissue in place; then, removing the nozzle of the atomizer tube from the aperture, I direct the spray directly on the tissue, taking care that the current is parallel to the length of the membrane; in almost as short a time as is required to fix the membrane to the plate the whole is frozen and stands erect in a vertical plane, provided that at the moment of freezing a slight tension is exerted by the needles or forceps. If the position in which the tissue becomes fixed is not satisfactory a warm breath relaxes it in a moment, and the adjustment can be corrected. In making sections of such delicate tissues or very small fragments it is essential that the blade of the knife should be kept cold. Another and very important use which I have made of the instrument — and an employment destined to be more and more commonly made of it is the examination of tissues from the living subject. The surgeon in excising new growths is desirous of carrying his scalpel through perfectly healthy tissues, and of removing all the surrounding parts which are becoming infiltrated with the malignant products. The determination of this question, and therefore the completeness of the operation, is often a difficult matter. It is not possible with the naked eye to be absolutely certain that all the affected parts have been removed, and how frequently it happens in examining with the microscope the periphery of tumors after removal, for example, tumors of the breast, that a deposit of malignant cells is found in the adipose tissue, often far from the growth in the gland. A small fragment of tissue, whether suspected or not, can be immediately frozen and cut, and the examination made before the wound of operation is closed. I have within the last six months made several such examinations during operations at the Pennsylvania Hospital. Recently, also, through the kindness of my friend Dr. L. A. Duhring, I have had the opportunity of using the instrument in making sections of diseased skin taken from

living patients. The sections were made and mounted ready for microscopic examination before the blood had ceased flowing from the small incision. The fragments of skin were in some cases not one fourth of an inch in length, and probably less than one eighth of an inch in breadth,— fragments so small that the attempt to harden them in reagents resulted in their complete disintegration and loss.

Recently, also, I have been able to obtain sections of the contents of cysts in situ, both from ovarian tumors and from cysts occurring in a fibro-cystic growth of the uterus.

Now that the method of freezing is so widely and generally used in making sections of tissues, it is not necessary to defend the process from the charges formerly made against it, namely, of cold producing alterations in the cells, etc. In fact, the tables are turning, and those who use the old hardening process and the tedious embedding of tissues are called upon to defend their methods against such charges.

One word more concerning the subsequent manipulation and mounting of sections made by the freezing process. As before related, I usually transfer the sections to cups containing appropriate solutions, but frequently the sections are placed directly on the slide and there stained, etc., and mounted. By this latter method nearly all the cells contained, in a section are retained, even if displaced from their original site.

In mounting the sections, which in the first place were transferred to a cup, I usually place them on the slide and perform all the manipulations necessary while they are on the slide. The advantage of this method is that the sections are saved from the danger of breaking or tearing to which unhardened tissues are necessarily peculiarly liable in the process of transference from one dish to another. By this method the section is always floating, and rarely needs to be touched by the needles; the disadvantage is the greater waste of reagents.

The difference in the appearance of tissues sectioned by freezing and those cut after hardening in alcohol, for example, a normal kidney prepared by the two methods, is very great. A normal kidney hardened in alcohol more nearly resembles a section of contracted kidney made by the freezing process. I do not find that sections of frozen tissues when treated with the alcohol, necessary to transferring them to oil of cloves and dammar, are much altered by this reagent, at least not nearly so much so as when hardened by it previously to sectioning. In this brief notice of the freezing microtome and the uses to which I have applied it, only a few of my experiments have been mentioned, and I have not considered it necessary to speak of the various solutions, reagents, and staining fluids which I commonly employ. Different tissues require different treatment by reagents and staining fluids, and each worker has his own peculiarities and favorites. To make this part of the subject complete, a catalogue of the various organs of the body would be nec

essary.

RECENT PROGRESS IN ORTHOPÆDIC SURGERY.

BY E. H. BRADFORD, M. D.

Caries of the Spine; Plaster-of-Paris Jackets. The advantages of Dr. Sayre's method of treatment of Pott's disease are shown in a paper written by Mr. Willett, of St. Bartholomew's Hospital, and published in the Hospital Reports.1 Mr. Willett wishes "to express unhesitatingly the satisfaction he has experienced in the treatment of both angular and lateral curvature of the spine by suspension and the application of the plaster-of-Paris bandage," a method of treatment which he says is now adopted in all the large London hospitals. His conclusions are based upon sixty cases of caries of the spine treated according to Dr. Sayre's method. An analysis of these cases is given. He adds: "The most eloquent testimony in favor of Dr. Sayre's method is the eagerness with which children who have once experienced the ease which the plaster jacket has afforded them have craved to have it left on" when it has been necessary to remove it. Mr. Willett has not been able to satisfy himself that the change in the outline of the spine during suspension is due entirely to the pulling apart of the diseased vertebræ. He also finds that the time needed for a cure is longer than that stated by Dr. Sayre.

2

Dr. N. Shaffer, of New York, in a paper read before the Academy of Medicine, points out the disadvantages of the plaster-of-Paris treatment. He says that plaster jackets are heavy and filthy, that excoriations and chafing may arise and progress without being known, and that the application is attended with danger and difficulty. He claims that as a support a plaster jacket is a failure when the disease is above the seventh dorsal vertebra, that the "jury-mast is inoperative, and that the principle of antero-posterior support is the correct one in the treatment of the affection." He believes that continued extension and counter-extension which could be maintained with any degree of efficiency is impossible.

3

In regard to the dangers attendant on suspension employed during the application of "plaster jackets," Mr. Willett mentions that vomiting occurs quite frequently while adults are suspended, and that in some cases there is fainting. In one case syncope seems to have taken place during the application of a plaster-of-Paris bandage upon a child, accompanied by a temporary paralysis of the muscles of the neck. No fatal cases have been reported, except one mentioned by Mr. Willett. Vomiting began shortly after the application of the jacket; the jacket was removed, but the vomiting persisted, and the patient died in two

1 Vol. xiv., 1878.

2 New York Medical Record, No. 2, page 177.

3 Lancet, February 8, 1879, page 214.

days. At the autopsy, a chronic dilatation of the stomach was found. The application of the jacket was apparently the exciting cause of death, though the method of treatment can hardly be blamed for the termination of the case, as an unexpected organic lesion was discovered. Respiration is not much interfered with, according to Mr. Willett, by the plaster-of-Paris jacket; in two patients, however, both paralyzed from disease in the upper dorsal vertebra, an attack of acute bronchitis produced such urgent dyspnoea that it was necessary to remove the jacket. Two somewhat similar cases are mentioned by Madelung.

To avoid the difficulties and dangers of suspension in the usual way, Dr. Reid1 recommends a modification of the apparatus described by Dr. Sayre. The arrangement for suspending the head and neck is similar to that in general use, except that a separate pulley and rope are used for the head. Suspension of the trunk is made by means of adhesive plaster applied to the trunk. Plasters "two and a half inches wide are applied along the back, across the shoulder down the body, leaving a loop (above the shoulder) for suspension." An ordinary bandage is wound round the body to retain the plaster, a rope passed through each loop, and the patient can be hoisted and hung without danger as long as necessary. The plaster-of-Paris bandages are applied in the ordinary

way.

Walker 2 believes that suspension is not a necessary part of the treatment of caries of the spine. He writes: "That a jacket should be effectual, it is a sine qua non that it shall be applied when the spine is in such a position that the diseased vertebræ shall be free from all pressure, and the deformity, if deformity exist, be reduced to a minimum. This condition is found when the patient is suspended, as recommended by Dr. Sayre, but it also obtains in an equal degree when the patient is laid flat on the back."

To make the application of a bandage on a patient in a recumbent position practicable a many-tailed bandage is used. The separate strips are soaked in plaster of Paris mixed with water, to which mucilage of acacia is added to prevent too rapid setting (proportions, one pound of plaster of Paris, one ounce of mucilage of acacia, and eight ounces of water) of the plaster. The strips are arranged and the patient is laid upon them; they are then folded around the patient. Two layers of bandages are usually enough for a child, while three are needed for an adult. Mr. Walker summarizes his opinion as to the treatment of caries of the spine, based upon an experience of seventeen years, as follows: "The main object of the treatment of angular curvature of the spine should be the maintenance of the affected bones and joints in a state of absolute rest, and that in the position most favorable for the 1 New York Medical Journal, July, 1878, page 37. 2 British Medical Journal, March 1, 1879, page 306.