parotid, now the ovary, or the testicle; the eruptions of psoriasis form similar groups of scales upon both elbows.

New growths resemble normal tissues in their elementary composition and arrangement. Sometimes the elements form an amorphous group. When they become organized they follow the law of development, that is from protoplasm to granule, nucleus, cell, fiber and membrane. Fibrous membrane is exceptionally developed from structureless protoplasm, skipping the cellular stage.

Morbid products may reach and be arrested at any stage of development; a, as a liquid; b, liquid with nuclei and cells; c, liquid, nuclei, cells and fibers variously arranged.

Morbid growths increase, remain without alteration or waste, shrivel and disappear. They increase by additions of protoplasm to that portion in contact with the body (exudation), and by the development of blood vessels beneath, which may penetrate and carry protoplasm into the mass. In general, the greater the increase in size, the less the development. Increase may interfere, strangulate and destroy the parasitic life by (1) stopping nutrition, (2) by absorption through the vessels of the heterologous, decomposing matter.

Alkalies, acids and some salts often prevent the formation of a coagulum or membrane, upon a diseased surface. When there is much fibrin, the color of a pseudo-membrane is a dirty bluish gray; when there is albumen and fat, it is yellow; when there is decomposed blood corpuscles and coagula, it is reddish, or purplish white.

These exudates have an inherent power of development, but they must remain in contact with the living tissues. Deficiency of vital power cannot account for non-development of these exudates. In very low states of the system, we often find enormous developments of fibrin and new growths. The blood may be dyscrasic; the local inflammation may not be sthenic enough; the chemical and vital power of the underlying tissue may prevent, or its nervous activity forbid a high grade of organization. Pseudomembrane agrees with fibrin, in having many interlaced fibers, soluble in Acetic acid; intermingled are round, oval and rod like nuclei; granular cells, or leucocytes; mucous and pus corpuscles.

There may be much amorphous jelly in the transition stage. A morbid exudate undergoes three kinds of retrograde metamorphosis. It may be resolved into a pulpy, cream white, or, if it contains blood, reddish gray, or chocolate fluid; containing granular nuclei and pus cells. It may undergo a true fatty degeneration, and leave a net work of more resisting fibers. It may shrivel and dry into leathery shreds.

When the crisis of a disease is exhausted, an exudation of serum takes place beneath the parasitic product and pushes it off. Diphtheritic and croupous exudations and membranes furnish a basis for many of these propositions. I have made a microscopic study of several specimens of diphtheritic pseudo-membrane removed from the velum palati, the pharynx and larynx. The results have proved interesting, though the research was dangerous. I find them in accord with pathological principles established by the masters, and present them for consideration. Diphtheria is a blood disease, evolving a poison, which is for the most part eliminated by the mucous membranes, for which it may be said to have an affinity. The throat, on account of its vascularity and exposure to irritants, is a favorite seat for exudation, but the mucous membranes of the nose, mouth, larynx, alimentary canal, urinary tract and vagina are frequently affected, and sometimes, open wounds of the skin show the specific exudate. Lesions of surface predispose to the morbid development, and contiguous glands undergo infarction and become tumefied. The more severe the disease the greater is the exudation, and the less the development of the exudate. Copious exudation may be regarded as favorable to the patient, but it is often diminished by sloughing of the underlying tissues. Organized pseudo-membrane is not necessarily of bad omen, unless located in the larynx. It is freed by gangrene of the underlying membrane, by a change in the exudate to a more fluid condition, and by its own degeneration. It is more liable to be detached spontaneously from the muscular, movable pharynx, than from the larynx. It is generally softer and more vascular in the former situation, than in the latter. Its fibers are arranged indefinitely when in the pharynx, but, when formed in the larynx, there is a great preponderance of fibers run

ning in a direction parallel to the vocal cords. The subjacent tissues influence this arrangement in a remarkable degree. Though this fact is of little importance, I claim to be the first to place it upon record.

I divide the diphtheritic exudate into three kinds :

1. A simple, morbid, amorphous protoplasm, composed of blood serum, albumen and mucin. This cannot be separated from the detritus of epithelium and mucous corpuscles, which come from the diseased surface through which the exudation passes.

2. The semi-fluid constituents of number one, with the addition of nuclei, leucocytes and red blood corpuscles lying in interstices of a loose fibrinous matrix.

3. The constituents of number one and two in moderate quantity, with a larger amount of fibrin than in number two, having its fibers running in every direction, and forming a dense, leathery membrane, resembling that which lines the egg-shell of the fowl. The free surface is the densest, and the stroma diminishes and becomes looser towards the mucous membrane. One case of diphtheria may have only the jelly-like exudate of the first; another the jelly and slight organization of the second, and another the truly organized membrane of the third group.

One case may, at different stages of the disease, have each of these products in succession, not always regular.

Bacteria are often found, but are not considered significant. The first and second groups occur most frequently upon the velum and pharynx; the third in the larynx. Some acids, alkalies and salts modify the characters of diphtheritic deposits, but they should be used cautiously.

CANCER AND IT'S DIAGNOSIS.

BY J. EDWARDS SMITH, M.D.

It is somewhat remarkable that a word sufficient in its import to strike with terror the strongest heart, should nevertheless, from a histological or pathological standpoint, resist all and singular any attempt to accurately define the same. Alluding to this situation, Dr. Arnott says: "At the present time no term is used more vaguely, and yet with more caution and misgiving, both by pathologists and practical surgeons, than the term 'cancer.'" Dr. Arnott says further: "The common argument of the practical surgeon is something like this: When I speak of a cancer I mean a tumor which will return if I cut it out, which will probably also appear eventually in certain internal organs, and against which I am well-nigh helpless in any effort to eradicate it from the system. * It is only quite lately, long since the microscope has come into general use in medicine, that the various diseases of the lung family, grouped under the heading 'consumption,' have been recognized and classified. Few physicians will long rest satisfied with being told that a given case is one of phthisis. They will further ask, whether it be a catarrhal pneumonia, or an interstitial pneumonia, or a chronic tuberculosis. Just in like manner it behooves us to recognize that we can no longer content ourselves with the assertion that a given case is one of cancer. * * * We must look further, we must see to what special class of malignant growths the case properly belongs."

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Thus it is to be noticed that Dr. Arnott relegates the cancers to the domain of malignant growths; and it becomes of interest to define accurately what shall be understood by the use of the word 'malignant.' "By malignancy," says Dr. Arnott, "we imply such an energy of growth as baffles in a greater or lesser degree the surgeon's interference; and it is convenient to speak of three degrees of malignancy, viz.: 1st. The persistent recurrence in loco, after apparently complete removal by the knife. 2d. The

tendency to infection of the nearest chain of lymphatic glands with the same morbid growths; and 3d. The possible combination of one or both of these conditions, with a proneness to the formation of other like tumors in distant parts of the body, especially in the lungs and liver."

A late author on pathology and morbid anatomy, Dr. T. Henry Green, of London, England, defines malignancy thus: "By 'malignancy' is understood the property possessed by many tumors of reproducing themselves, either locally after removal, or in distant tissues. It is important not to confound the terms 'malignancy' and 'cancerous.' Malignancy is a purely clinical term, and although in a high degree the property of the cancers, is by no means confined to them, the sarcomata, for example, being in many cases equally or even more malignant. The term cancer, on the other hand, is used to imply a definite structure, and as such is applied to a certain class of new formations."

Accepting, then, either definition of the word 'malignancy' as thus given by Drs. Arnott and Green, as sufficiently definite, it is proper to say, that under the general heading "cancer" I recognize generally all "malignant" growths.

Fully thirty years ago, a remarkable paper on the subject of cancer and its microscopic diagnosis, from the pen of Dr. Francis Donaldson, of Baltimore, Md., made its appearance in the columns of the American Journal of Medical Science, vol. xxv, page 43. I proceed to give, as briefly as possible, the salient points contained in this paper. Dr. Donaldson insists that it "is improper to attempt to divide cancer into so many species, as they all have the same common pathology. The variety of aspect, consistence, volume, coloration and vascularity, is caused merely by the amount of fibrous element, of fat or gelatinous fluid present, all of which are purely accidental and in no way essential to constitute the growth. The density, softness, &c., may also vary according to the organ involved; the breast and the pylorus take generally the form of scirrhus, whereas the bladder, the kidneys, &c., are more likely to be affected with encephaloid."

Thus we find, that thirty years ago Dr. Donaldson pointed out the impracticability of any classification of cancerous growths