aspiration to secure the obliteration of the cyst by inflammation. The injection of carbolic or salicylic acid under the same conditions has been practised with success by Mosler and others.

The treatment of old suppurating cysts is rather different. The centre of the sac, as nearly as can be judged, is fixed upon, and an incision is then made through the skin and muscles, and the largest-sized trocar and canula that will pass between the ribs is introduced into the sac. This gives exit to a quantity of pus, even chalky substances and fragments of cysts of different sizes. The opening must be free and kept patulous for some weeks, and the sac should be daily washed out with some disinfecting solution through the drainage-tube. Some delay is always necessary to allow of the separation of the parent cyst from its nidus and the gradual expansion of the lung. Immediate attempts at its removal by forceps are generally unsuccessful, and portions are very apt to be left behind. Several complications may interfere with the success of the operation. One is the unavoidable piercing of a small bronchus by the trocar. After the operation the wound of the bronchus may remain patulous and a violent paroxysmal cough comes on, with subsequent possible evacuation of the cyst through this channel. The bronchial tubes, however, have been opened in operative treatment of pulmonary cavities without serious result. When the parent cyst has progressed to maturity quite unhindered, and is stuffed full of daughter cysts, it has been recommended in such cases to introduce the stylet and endeavor with its sharp point to stir up and break down the smaller cysts as much as possible. The thermo-cautery has recently been used successfully by Mosler to afford a means of penetrating the cyst in the treatment of pulmonary hydatids. The tissues of the thoracic wall must be first divided down to the pleura, as recommended in the opening of pulmonary vomica by the thermo-cautery. Resection of the ribs should be practised in case sufficient drainage cannot be accomplished through an interspace.

Before applying to these operative measures it is desirable that adhesions should have occurred between the visceral and the parietal pleura. Fenger and Hollister recommend the introduction of a needle as a means of diagnosis: if there be adhesions, it is unaffected by respiration; if no adhesions exist, it is moved synchronously with the breathing. There are, however, no absolutely reliable signs by which this adhesion can be determined. Paracentesis of suppurating sacs has been performed in cases in which the pleural surfaces have not been adherent. In some instances the lung has been stitched to the opening in the pleura, and after partial adhesion has occurred the purulent collection has been punctured. In certain other cases, when pleural adhesions have been absent, paracentesis has not been followed by serious pneumothorax, possibly because the apposition of the pleural surfaces is maintained by the tendency to cohesion which exists, and after operative interference these surfaces are united by adhesive inflammation.

ACUTE MILIARY TUBERCULOSIS.

BY JOHN S. LYNCH, M. D.

ACUTE MILIARY TUBERCULOSIS may be defined to be an acute disease characterized by an eruption in one or all of the organs of the body of small nodular or granular masses called tubercles, attended with fever and various other functional disturbances.

The fact which Villemin and Klebs were the first to show,' and which hundreds of others have since verified, that tuberculosis can be conveyed by inoculation to certain animals, and the additional fact that Koch and his followers seem to have identified the infective material in the micro-organism which he has named bacillus tuberculosis, would seem to justify our placing tuberculosis, along with variola, measles, etc., among the acute contagious infectious diseases. But since some able pathologists still deny the correctness of Koch's conclusions; since in certain animals indifferent irritants have excited a disease which could not be distinguished from tuberculosis by the ablest pathologists of Europe and America; since to some species of animals even more nearly allied to man by their organism than rabbits and guinea-pigs the disease cannot be conveyed at all, and that even to some of the latter inoculation fails to transmit it; and, above all, since there is, as far as we know, not one single case on record in which the disease has been clearly and unmistakably traced from man to man in the order of infection, we do not think that as yet we are justified in defining it as a contagious infectious disease purely and only. Everybody will take small-pox if not protected by vaccination or inoculation, and this disease may be transmitted in a modified form to many of the lower animals. The same may be said of measles, scarlatina, and nearly all other diseases known to be contagious and infectious. Since, then, so few persons take tuberculosis that the evidence of its contagiousness rests upon a vague popular belief, and since even some animals of a species known to be liarly susceptible to the disease fail to take it even by inoculation, we think that we are justified in assuming that there must be something else besides a contagium required to produce the disease. This is evidently a predisposition which depends upon some peculiar diathesis, cachexia, or dyscrasia, congenital or acquired. It has been assumed that scrofula constitutes the particular diathetic condition which predisposes to tuberculosis, and it is common for scrof ulosis and tuberculosis to be spoken of as convertible terms. In the article on SCROFULA in this work we have already given our reasons for dissent from this view, and to that article the reader is referred. Farther on we shall give our views as to what constitutes the tubercular diathesis when we shall speak of the mode of formation of tubercle.

pecu

While, then, we cannot as yet admit that acute miliary tuberculosis is always and only set up by a contagium, it is unquestionably true that it is in a large majority of instances caused by an infective material, which, however, But Buhl had long before advanced the doctrine that tuberculosis was a resorption disease.

does not come from without, but is produced within the system. This material is the purulent detritus resulting from the softening and breaking down of the inflammatory and other cellular hyperplasias which have undergone the caseous degeneration. It seems to make little difference whether the caseous product was derived from scrofulous glandular hyperplasia, catarrhopneumonia, inflammation of serous membranes with a cellular exudation, or ordinary cellular inflammation; the only essential prerequisites being that there shall exist a cellular exudation or proliferation, and that these cells shall undergo the caseous degeneration.

The inoculation of this material into certain species of the lower animals or its absorption into the blood of a human being predisposed to tuberculosis will, as a rule, produce tuberculosis. Koch and his disciples add to the foregoing another prerequisite-viz. that the caseous matter must contain the bacillus tuberculosis. But as the bacillus is generally found in all the cheesy inflammatory products we have mentioned, they have (ignoring Virchow's definition of tubercle) declared that all these are tubercle, thus very much enlarging the hitherto accepted doctrine upon this subject. But if any of the cheesy products are found not to contain the bacillus, then such product is not tubercle, whatever may be the apparent identity or dissimilarity in their etiology, microscopical appearances, or clinical history. This seems to us to be a begging of the whole question of the relation of the bacillus to tubercle, and in the absence of fuller experimentation and investigation involves an assumption which cannot yet be admitted.

While the absorption of caseous pus is undoubtedly by far the most frequent cause of miliary tuberculosis, it cannot be inferred that all who may happen to have foci of caseous degenerations will necessarily be attacked by tuberculosis. On the contrary, a vast majority escape, and it is almost surprising how few of those who suffer from scrofulous inflammation of glands, joints, etc. become the subjects of miliary tuberculosis. Many cases of pulmonary phthisis also, originating as a cheesy pneumonia, run their course without any distinct tubercular complication. We can only explain these exemptions from the tubercular process by supposing that in such cases the predisposition to tuberculosis does not exist-they do not have the tubercular diathesis or that such persons possess a peculiar means of resistance to the entrance of the infecting material into their blood.

Other diseases are supposed to favor the tubercular process, either by directly exciting or increasing the predisposition to it. Among others, measles, whooping cough, and typhoid fever have been regarded as specially liable to be followed by tuberculosis. Bad air, poor or insufficient food, onanism or other forms of sexual excess, severe study with insufficient exercise, and, in short, anything which impairs the strength or lowers the vitality, have been heretofore considered as excitants or predisposers of the disease. Admitting all these causes as effective in either exciting it or increasing the predisposition to it, there still remains quite a large residuum of cases in which the disease can be traced to none of these causes, and which, for the want of more accurate knowledge, we are compelled to call idiopathic or spontaneous. Such are those cases of tubercular meningitis. occurring in young children heretofore in apparent good health, and in whom no traces of caseous degeneration can anywhere be found. It is true that it may be asserted that these children may have been infected through kissing by persons suffering from pulmonary consumption; but if this were so the disease ought to be far more frequent than it is, since the habit of kissing babies is universal and consumption the most prevailing of all diseases. In the absence of any proof to the contrary, we think that we are justified in believing that these are cases of spontaneous tuberculosis, occurring in consequence of intensity of the diathesis, either inherited or acquired.

Miliary tubercles are found in the form of small roundish nodules ranging in size from to inch (submiliary tubercles), up to the size of a milletseed or even of a pea. When of the latter size they are always made up of a number of submiliary tubercles. Much larger masses are found usually in the lungs and in the mesentery, but these will generally be found to consist not of miliary or submiliary tubercles alone, but of cellular new formations derived from endothelial or lymphatic proliferations excited by the presence of tubercles, and therefore mixed with them. When first formed they are grayish in color, somewhat translucent, and tolerably firm to the touch (gray granulations). They soon, however, undergo partial fatty degeneration (this degeneration usually commencing in the centre of the mass), and subsequently are converted into a dry, yellowish-white, and somewhat crumbly mass which from its resemblance to cheese is called caseous. This sooner or later softens (the softening process beginning also in the centre), and the mass breaks down into a fluid detritus-tubercular pus. In some situations they never reach the caseous and purulent stage (notably in the cerebral meninges), because the interference with the organs or nerve-centres of animal life excited by their presence destroys the patient before there is time for the accomplishment of these changes. The subsequent history of tubercle depends upon the condition of the patient, his powers of resistance, the intensity of the tubercular diathesis, the injury inflicted by the first eruption, and the appearance of secondary eruptions. If all conditions are favorable, the patient placed under proper hygienic conditions and properly treated, the first eruption will also be the last, and the tubercle dries up into an earthy mass (calcareous degeneration), or it may remain for months, and even years, in its caseous stage without undergoing the softening process.

If we examine a fresh tubercle under the microscope, we find, according to Woodward' and Zeigler,' that it is usually made up of three different kinds of cells first and most abundantly, lymphoid cells (Woodward) or white blood-cells (Zeigler); second, endothelioid cells; and third, embryonic cells. In addition to these there is often found (but not always) a few so-called giant-cells, generally occupying the centre or circumference of the tubercle, and sometimes both. These cells, which usually contain two or more nuclei and are much larger than the ordinary lymphoid cell, were thought at one time to constitute an essential histological feature of tubercle, and have been named tubercular cells. But the frequent absence of these cells in genuine tubercle has led to the conclusion that they do not possess any special significance and are purely accidental. Each submiliary tubercle is usually surrounded by a proliferating zone in which multinuclear (giant) cells and fibroplastic or spindle-form elements can be distinguished (Cornil and Ranvier3). According to Rindfleisch, Woodward,' and Zeigler, the cellular elements of tubercle are always found included in a trabeculum of fine fibrillar (connective) tissue, while Cornil and Ranvier deny the existence of any such trabeculum, maintaining that its appearance is due to the action of hardening agents used for preparing it for microscopic examination. Virchow and Woodward believed that tubercle always takes its origin in a lymphatic vessel, while Rindfleisch, partially agreeing with this view, maintains that they most generally occur in the lymphatic sheaths of the blood-vessels and follow the course of the latter, and that the cells which compose the tubercle are formed by proliferation of the endothelia of the lymphatics.

593.

Medical and Surgical History of the War of the Rebellion, Part 2, Medical Volume, p.

Pathological Histology, Philadelphia, p. 116.

5

Op. cit.

Textbook of Pathological Histology, Philadelphia, 1872, p. 125.

Zeigler has not been able to demonstrate this relation of the tubercle to a blood-vessel-that is, to an artery-but leaves us to infer that they always arise from a capillary vessel, since he maintains that the tubercle is primarily and principally made up of emigrated leucocytes.

Such is a brief résumé of our knowledge as to the histology and mode of formation of tubercle, and such are the opinions-in some particulars agreeing, in others discordant-of those whose investigations and observations the world regards as most complete and accurate. This résumé is doubtless unnecessary and out of place in this article, since this question (the histology and mode of formation of tubercle) has been already discussed in the first volume of this work; but, as in the explanation which is to follow of our views as to what constitutes the tubercular diathesis and what is the mode of formation of tubercle we shall have to frequently refer to the facts above stated, we have thought it best, in order to save repetition and too frequent reference to authorities, to give the above résumé of the present state of the views of pathologists upon the histology of tubercle.

A careful consideration of the foregoing facts ought, it seems to us, to enable us to arrive at a rational and probably correct conclusion as to the mode of formation, as well as the principal etiological factors concerned in the causation, of the miliary tubercle; and we venture to offer the following explanation of the subject as more in consonance with the facts above related than any view which we have seen upon this question:

1. Miliary tubercles always occupy a lymph-space surrounding a capillary blood-vessel. When found, as they quite often are, occupying the wall of a larger vessel, artery or vein, it is still in the lymph-sheath of a capillary of the vasa vasorum that they primarily originated. And it may be said that this is the most dangerous site a tubercle can occupy, because when softening takes place it is so apt to burst into the lumen of the vessel and so produce a general infection.

2. The tubercular process consists at first of an undue or excessive emigration of leucocytes through the walls of a capillary which runs through a lymph-space, and where, of course, the walls of the vessel are less firmly supported. Those cells whose vitality is lowered by the causes which have preceded and excited the process can neither undergo any process of differentiation nor wander on through the lymphatics; they remain in the lymph-space, which they crowd and block up, and finally by their pressure occlude, the capillary vessel from which they emigrated. Until this event occurs they still retain a feeble vitality, and even abortive attempts at proliferation are seen, which, however, only reach the stage of division of the nucleus, the body of the cell meanwhile swelling up by imbibition and thus forming the so-called giant-cell. As soon as the capillary vessel becomes occluded further addition to the incipient tubercle from this source ceases; nutrition is now entirely cut off, and the cells, dying, become a foreign substance, and soon undergo the caseous degeneration. But by their presence they now excite a quasi-inflammatory process in the endothelia lining the lymph-space, and hence we have a secondary addition to the tubercle derived from the proliferating endothelia. Lastly, the inflammatory process extends to the connective-tissue cells around the lymph-space, and embryonic cells (the only cells capable of resulting from connective-tissue inflammation) are added to the mass. This constitutes the proliferating zone, consisting of many nucleated cells and fibro-plastic and spindle-form elements, described by Cornil and Ranvier.'

As soon as one capillary vessel becomes entirely occluded, the neighboring ones become distended by a collateral hyperæmia, and the same process of cell-exudation or emigration begins; and thus the process goes on until all the capillaries supplied by a single arterial twig take part in the process, and

1 Loc. cit.