do with its course. If the cause be pneumonia, the course will be such as the detail of symptoms already given shows. In some unknown way the natural course of the disease is interrupted, and what promises to be an average case is followed by the characteristic features of abscess. If pyæmia be the precedent condition, a peculiar form of pneumonia, embolic in origin, appears, and abscesses again follow. Greater septicity and rapidity of destruction are probable sequences. The perforating abscesses are subject to modifying influences of mechanical effect, such as gravitation and the resistance of tissues, and have their peculiar course, which is often marked by great chronicity.

TERMINATION. In the course of seventeen years the reports of the Cincinnati Hospital show that there have been 6 cases of abscess of the lung treated there. Of these 4 died and 2 were discharged as improved. These figures show the infrequency of such cases, and also represent a greater mortality than probably occurs in the non-hospital class. We know of no large statistics which show what is the percentage of recoveries. Our own experience in private practice gives a majority of recoveries. They were cases following typhoid fever, croupous and catarrhal pneumonia, and hepatic abscess. A termination in a chronic cavity now and then happens: perforation of the pleural cavity, with subsequent pyo-pneumothorax, discharge externally through an intercostal space, or even extension into the abdominal cavity, are among the actual events of such abscesses.

DURATION. The duration of an ordinary case is subject to wide variations between one and six months. A few cases are recorded of several years' duration. Previous constitutional condition has much to do with this element. The degree of infectiousness in the pyæmic class is important as to time. The abscesses become a subordinate condition in the fate of the case. In this connection we may also refer to Leyden's third variety, a so-called chronic ab

scess.

PATHOLOGY.-A close parallelism, etiologically and otherwise, is observable up to certain points between gangrene and abscess of the lung. Both are products of, or associated with, pneumonia. That which finally determines whether the result shall be gangrene or abscess is unknown to us. In the article on GANGRENE OF THE LUNG some investigations are referred to which point to a probable solution in the existence of specific forms having special pathogenetic force. The tendency of experimental and clinical investigations is to connect the suppurative process closely with the product of specific germs. Ogston in 65 cases of acute abscess found micrococci present in all of them. Obstruction of blood-vessels in the centre of the pneumonic area or on the margin of the abscess walls is an important anatomical element in the production of abscess, and it is claimed that it is often due to colonies of micrococci within their calibre; so that it is probable that there are both mechanical and biological or chemical influences at work. If the view of the zymotic and infectious character of pneumonia be tenable, the contingency of an abscess developing in its course would seem not very remote. Yet the proportion of cases of abscess from pneumonia is not more than 2 per cent. Leyden's high authority supports the idea of the essential and specific differences in the chemical and morphological peculiarities of gangrene and abscess of the lung, but the subject is as yet on a hypothetical basis.

MORBID ANATOMY.-The fresh cavity, generally in the upper lobe, has rough, ragged, and irregular walls, and may have bridles of the more resistant structures, as bronchi and vessels, crossing it. Such a cavity is quite likely to contain portions of undissolved parenchyma or more or less malodorous pus. The older cavity becomes smoother walled, and of more regular limits and cleaner contents. A gradation from granular hepatization through congested to crepitant tissue is almost uniform in the varieties of abscess,

whether simple or pyæmic. In addition, some peculiarities are observable in the latter. These are usually several, varying in size from a pea or less to a walnut, some round and others wedge-shaped; others lying superficially and forming slight elevations on the pleural surface. In proportion to the curative progress the cavity will contract and disappear, occasionally leaving behind cicatricial mark. A lining pus-secreting membrane will sometimes form, resulting in such a limitation of morbid action and such a disappearance of reactionary symptoms as to make the disease entirely local, but quite chronic. DIAGNOSIS. The more or less sudden and copious expectoration of pus, without a specially offensive odor, in the course of a case having up to that time the history of a pneumonia, would be considered as due to the development of an abscess in the lung. Some degree of fetor in breath and expectoration is observed, but it is far different from that of gangrene. The detection of the débris of lung-structure in coarse particles, and the microscopic discovery of elastic lung-tissue, are important diagnostic points in contradistinction from the solution of tissue that gangrene usually effects upon the parenchyma of the lung. According to Leyden's' very complete investigations, the microscope reveals fatty crystals, mostly in roundish fragments, of the size of the epithelium of the lung and of a brilliant structure; pigmentdébris of a yellowish-brown or brownish-red color; hæmatoidin and bilirubin, which Traube thought were due to hemorrhagic infarction, but which Leyden has observed in all of his cases; and, lastly, micrococci, in the well-known form of the round, granular micrococci colonies, which differ from those in gangrenous fragments in that they show very little movement and do not give the iodine reaction.

Difficulties of diagnosis arise in the case of an empyema discharging through the bronchi, or of an encysted empyema discharging through the third or fourth intercostal space in front; also, between abscess of the superior portion of the liver and one in the base of the lung, or between the latter and a pyo-pneumothorax. Very careful study of the history in each case is of the first importance. Where this is not attainable the difficulty is often much increased. In the case of the empyema the discharge is more profuse at each time, the whole amount in a given period is much greater, and the time of opening is much delayed beyond that of the pneumonic abscess. Trousseau gives the case of a child who brought up for more than six months 200 grammes of pus daily. He makes children an exception to the rule as to the late opening of the pleural abscesses. In the encysted empyema discharging either internally or externally the difficulties are greater. A portion of the lung-tissue may be so near behind the deposit of matter as to make the physical signs confusing if the pus has opened externally. Some of these and of the interlobular deposits it is almost impossible to diagnose. In hepatic abscess opening into the lung and bronchi the discharge is copious, dirty brown, paroxysmal, and will generally, on careful observation, show the bile color or its chemical reactions or some microscopic débris of the liver. In Leyden's third class, or the chronic abscess arising in the course of chronic pneumonia, the history is so much like that of some forms of phthisis as scarcely to serve in diagnosis. He thinks there are some macroscopic and microscopic appearances which may serve for diagnosis. There are in the expectoration dark and compact pieces of greenish-black color, not unlike plugs of pus, and larger, black-pigmented fragments of parenchyma, from a pin's head to a hempseed in size. Microscopically, they consist of a close and strongly-pigmented parenchyma, which seldom reveals alveolar structure. They show fatty degeneration and cholesterin plates. This class of cases is mostly without fever. The application of the bacilli-tuberculosis test would seem to offer some assistance in diagnosis.

1" Ueber Lungen-abscess," Volkmann's klin. Vorträge, p. 994.

PROGNOSIS.-A grave prognosis may be formulated if there be a history of feeble constitution, and especially if it be further impaired by habits of intemperance, if the patient belong to either extreme of age, if there has been a recent debauch, or if there be wide variation from the typical form of pneumonia. Variations will be shown in such a complexus of symptoms as follows: fever of low grade, subject to extremes in range; feeble and frequent pulse, but not so marked as in gangrene of the lung; dyspnoea, objective and subjective; typhoid depression; tongue dryish; delirium; copious and fetid or difficult expectoration; physical signs of extensive lesion, such as a large cavity with a large outlying pneumonic area. A favorable prognosis would be conditioned on the appearance of a fewer number of these symptoms or on their evolution in a milder form.

The capacity of the patient to endure a long-continued suppurative discharge is principally determined by his natural vigor and his ability to assimilate food, other elements, such as extent of injury to the lung, being the same. A well-defined superficial cavity would be more favorable, because within surgical relief.

In the pyæmic variety the force of the infectious element will determine largely the result. Chills and sweats are important prognostic elements in such a case.

In the secondary abscesses of either the empyematous or hepatic variety prognosis is grave more so in the latter than in the former, because surgical procedure would be more promising in the former, and because of the implication of an organ so liable to destructive inflammation as the liver. A long and tedious course of suppuration is possible in either. The dangers in an established abscess arise from liabilities to septic infection and exhaustion consequent on want of reparative power and persistent suppuration.

TREATMENT. The treatment of abscess differs little if at all from that of gangrene of the lung. The tendencies of the two diseases toward exhaustion and infection are similar, but are less pronounced in the former. The same remedies are necessary in both, such as stimulants, tonics, antiseptics, anodynes, and expectorants internally, inhalations and drainage externally; brandy and malt liquors as stimulants; nourishing and concentrated food at frequent intervals; quinine as tonic and antiseptic; carbolic acid and turpentine as most valuable antiseptics (the latter being also an excellent stimulant); eucalyptus in cases of profuse as well as fetid discharge; carbonate of ammonia, senega, as expectorants; morphine and codeine or anodynes to control cough; carbolic acid for inhalation; and in cases of definitely localized cavities a free opening to be made with antiseptic injections.

Successful cases of surgical interference are reported, and such treatment is now recognized as proper when the system is giving way under septic poison, evinced in chills, sweats, and great prostration, where the purulent discharge is fitful and imperfect, and where the physical signs are clear enough to show the locality of the abscess.

GANGRENE OF THE LUNG.

BY WILLIAM CARSON, M. D.

DEFINITION.-Putrid necrosis of the lung-tissue.

SYNONYMS. Lungenbrand, Gangrene du poumon, Gangræna pulmonum. HISTORY.-By common consent, Laennec has the credit of first identifying, naming, and classifying gangrene of the lung as a distinct disease; yet Lieutaud' in 1707 describes imperfectly a case of gangrene of the lung in a child: "the right lung, within and without, appeared entirely putrid." Bayle' is considered, in his section on his fourth variety of phthisis (phthisis ulcereuse), to have described a rather chronic form of gangrene of the lung. Morgagni, Boerhaave, Stoll, J. Frank, and Cullen considered gangrene as one of the terminations of peripneumonia. Laennec's development of the subject has only in a few directions been enlarged. His classification is universally adopted. His description is adopted generally as the most complete. There have been, however, controversies on different points, such as the relation of pneumonia and of the obstruction of the vessels to gangrene of the lung.

In the pathology and etiology of gangrene Virchow's investigations on embolism and thrombosis opened up important relations; in diagnosis, Traube and Leyden and Jaffee; in medical treatment, also Traube; and in surgical treatment, Haley and Lawson (1879), S. C. Smith (1880), E. Bull (1881), Fengar and Hollister (1881), Mosler and Voght (1882). The antecedent development of pulmonary surgery, through important work done by Mosler, Pepper, and others, had prepared the way for special applications of it to gangrene and abscess of the lung. Spencer Wells claims to have suggested similar proceedings nearly forty years ago.

ETIOLOGY.-Predisposing Causes.-Constitutional weakness is a common predisposing influence: it may be a primary condition, but is more often secondary or dependent on some recently-acting debilitating cause, as typhoid fever, chronic lung disease, diabetes, etc. Chronic alcoholism is a cause which, besides its effect on the system at large, may add a special one on the lungs in producing hyperemia or drunkard's pneumonia.

Of 46 cases we have collected mostly from the Vienna Hospital report, the youngest was nineteen years old and the oldest was forty-seven years. Lebert has collected altogether 60 cases, 32 of his own and 28 of others: 19 occurred between twenty and thirty years, and 1 between thirty and forty. Huntington gives 32 cases from the Massachusetts General Hospital Record between 1857 and 1875: 9 were between twenty and thirty years, and 12 between thirty and forty; the youngest was ten years old and the oldest sixty-four. It is noticeable that these figures coincide largely with those.

1 Historia Anatomica Medica, 1787, Obs. 329, cited by Louisa Atkins, 1872.

2

Bayle, G. L., Recherches sur la Phthisis pulmonaire, 1809-10, p. 30.

I. Štraus, Nouv. Dict. de Méd. et de Chir., p. 403, etc.

Lungen Chirurgie, Mosler, xx. p. 67.

Klinik der Brustkrankheiten, vol. i. p. 827.

Boston Med. and Surg. Journal, vol. xcv. p. 486.

showing the incidence of phthisis. Louisa Atkins' gives, as the youngest ages among all the varieties, one of three months and another of two months. Of the 46 Vienna Hospital cases, 43 were male and 3 female. Huntington's cases were males 24, females 8. Of Lebert's own 32 cases, 22 were males; of the 32 others summarized by him, in 4 sex was not mentioned, and of the remainder 17 were males and 11 females. These figures show the large predominance of males in the liability to attack.

Exciting Causes.-They may be classified as pulmonary and extra-pulmonary. The influence of the alcoholic habit has been referred to above among predisposing causes: debauches are a frequent antecedent, especially in hospital cases, by means of resulting pulmonary hyperæmia and drunkard's pneumonia. Its association with croupous pneumonia may be assumed as settled after some warm disputes. The pneumonia of Bright's disease and putrid bronchitis are occasionally causative; bronchiectasies result in it not unfrequently. Extension of diphtheritic inflammation from the tracheal and bronchial mucous membrane is another form. The catarrhal pneumonia secondary to measles may produce it in children.

Embolism is the most frequent cause in the class of extra-pulmonary causes. It may be mechanical or infecting. A bronchial artery may be plugged so as to produce a gangrenous slough from mechanical cutting off of nutrition. Embolism of the pulmonary artery branches is more frequent, and by bringing about infarction and apoplexy may produce gangrene. Of the infecting variety may be mentioned emboli from the peripheral veins, as in surgical or uterine phlebitis, or from cerebral sinuses secondarily involved from otitis. Other causes acting from without on the lungs are foreign bodies, as particles of food passing beyond the trachea into the lungs, as in case of the insane or drunkards, and blows on the walls of the chest. These latter are capable of producing not only the ordinary phenomena of contusion-pneumonia but gangrene, and without evidence of external injury or fracture of the ribs.

SYMPTOMATOLOGY.-Gangrene of the lung is the termination of a process the beginning and progress of which are not declared or cannot be followed through characteristic symptoms. Even its final occurrence may remain unknown if a communication be not established with a bronchus, which event is followed by the true symptoms, the expectoration and its odor. Whatever symptoms occur previous to that event may occur independent of it. Adopting Lebert's dictum, gangrene of the lung is not a pathological unit. As its pathogenesis varies, so does its symptomatology. A feature common to its several varieties is marked constitutional depression and variations from the typical form of the disease in which it occurs. If pneumonia, croupous or catarrhal, be the precedent or associated disease, it will be marked by soft and feeble and frequent pulse, restlessness, dulness or distress of countenance, more or less cyanosis, cool and relaxed skin, possibly delirium, dry tongue, unusual dyspnoea and pleuritic pain, copious prune-juice expectora tion, irregular or non-typical temperatures. Along with these functional variations occur some in physical signs, as a lesser amount of dulness or of bronchial breathing, indicative of less structural density and corresponding exudation. A case with such an evolution may afford a presumption of an outcome in gangrene, but appearance of the characteristic expectoration and fetor is necessary to exclude it from irregular forms of pneumonia, which have no such termination. The same general remark applies to the cases of gangrene in bronchiectasic cavities. Perhaps some aggravation of the general condition may excite apprehension, but the characteristic phenomena of expectoration, odor, etc. must decide. If the cause be of embolic origin, we 1 Gangræna Pulmonum bei Kindern, 1872.

2 M. Litten, p. 26, vol. v., Zeitschrift für klinische Medicin.

3 Op. cit., p. 803.