Volume 3 — DISEASES OF THE RESPIRATORY SYSTEM. (continued 17)

As regards the different anatomical systems of the body other than the respiratory system, it is not important to add to the foregoing sketch details of symptomatology. The important symptoms referable to the respiratory system relate to cough, expectoration, and disturbance of respiration. The cough varies according to the quantity and character of the matter to be expectorated, the difficulty of its expulsion, and the susceptibility of the patient to the reflex influences on which cough depends. The matter expectorated is muco-purulent, and in many instances it is at times extremely fetid. This is due to the putrescency of morbid products detained within the bronchiectasic cavities and bronchial tubes, owing to difficulty in effecting their expulsion. The fetor may be suggestive of gangrene. The matter expectorated, however, if examined microscopically, will not be found to contain the débris of pulmonary structure. There may be sloughing of small portions of mucous membrane, but this is probably rare. The expectoration after certain intervals of putrid sputa in considerable or great abundance, the expectorated matter during the intervals having the characters of muco-pus without fetor, is almost pathognomonic of this variety of phthisis. The repeated occurrence of the putrid sputa, the clinical history, and the physical signs render it easy to exclude abscess of the lung. The detention of morbid products within bronchiectasic cavities, and the consequent putrescent decomposition, depend of course on the difficulty with which the contents of the cavity are expelled. This difficulty is greater if the cavities be in the lower than in the upper lobe. In a case which came under my observation the affection had been known by the attending physician to have existed for fifteen years. There was more or less habitual expectoration of ordinary muco-purulent matter, but after intervals of several days a considerable quantity of intolerably fetid matter was expelled. In this case the physical signs showed the affection to be limited to the lower lobe of the left lung. There was notable retraction of the lower and lateral portions of the chest on this side; solidification of lung was denoted by bronchial respiration and bronchophony over the posterior aspect; and the cavernous respiration was perceived over a circumscribed area in the latero-posterior aspect. This patient's general condition of health was fair; he had not a morbid aspect, and he was able to perform the duties of a clerkship in one of the municipal departments.

The respirations are more or less increased in frequency, the increase, other things being equal, being in proportion to the amount of damage of the pulmonary organs, or, in other words, the extent to which the respiratory function is compromised by the lesions. These may be sufficient to give rise to much suffering from dyspnoea. This was true of a case under my observation in which both lungs were extensively affected, while the muscular strength and the functions generally of the body were not greatly impaired. The embarrassment of breathing is increased by an accumulation of muco-pus within the bronchial tubes, and notable relief follows expectoration of the accumulated products. Hæmoptysis occurs in some cases, but much less frequently than in the ordinary form of phthisis. The hemorrhage is sometimes profuse. It proceeds from erosion of the walls of vessels or the bursting of small aneurisms within bronchiectasic cavities.

Cyanosis is marked in some cases. This symptom is not always in proportion to the dyspnoea; that is, the cyanotic appearance of the prolabia and face may be present when the patient does not manifest suffering from a sense of the want of breath. The cyanosis is symptomatic of distension of the cavities of the right side of the heart, this being an effect of the obstruction of the pulmonary circulation. The obstruction may lead at length to dilatation of the right ventricle and auricle. Thence arises the general dropsy which may take place at an advanced period of the history of fibroid phthisis. A tricuspid regurgitant murmur may be perceived with or before the occurrence of dropsy; also visible pulsation of the cervical veins. A frequent physical sign under these circumstances is bulbous enlargement of the ends of the fingers and sometimes of the toes. The clubbed fingers, as they are called, are symptomatic of disturbance of the circulation. They are observed in some cases of disease of the heart, phthisis not existing.

The physical conditions giving rise to physical signs are as follows: Notable shrinkage of lung; solidification, which, if the lung be much diminished in volume, may be considerable or complete in degree and extensive; dilated tubes and bronchiectasic cavities varying in size, number, and relative situations; the presence of muco-pus in more or less abundance, the quantity variable at different times within the bronchial tubes and cavities. Vicarious emphysema is more frequent than in the ordinary form of phthisis.

In typical cases of extensive and advanced unilateral fibroid phthisis the affected side is much contracted. The appearance is like that presented in some cases after recovery from chronic pleurisy. The range of respiratory movements is much diminished, the two sides presenting a marked contrast in this regard. With this one-sided contraction of the chest there may be lateral curvature of the spine, the concavity looking toward the affected side. The supposition that the contraction is in reality a sequel of chronic pleurisy is at once disproved by finding the evidence of a degree of solidification notably greater than would be incident to the mere diminution of the volume of the lung. If the affection be limited to a lobe, either the upper or lower, there may be contraction more or less marked over the portion of the chest corresponding to the affected lobe. If the two lungs be much affected, the evidence of contraction is apparent to the eye on both sides. It is rarely if ever that the two lungs are equally affected.

The signs furnished by percussion and auscultation which represent solidification of lung, the presence of air in dilated tubes or bronchiectasic cavities and emphysematous lobules, are present either separately or in various degrees of combination. Solidification from induration without dilatation, sacculated or otherwise, of tubes, or if these be filled with morbid products and without vicarious emphysema of adjacent lobules, will give dulness on percussion more or less marked and over an area corresponding to the degree and the extent of the solidification. There may be flatness over the greater part or the whole of an entire lobe. Often, however, dulness is found in some situation, and either tympanitic or vesiculo-tympanitic resonance in other situations. Over bronchiectasic dilatations a tympanitic resonance may have the amphoric or the cracked-metal intonation. On auscultation the respiration over a space more or less extensive or within separate spaces of variable extent is either bronchial or broncho-vesicular. With these respiratory signs representing solidification of lung are associated either bronchophony or increased vocal resonance, and the corresponding whispering signs—namely, whispering bronchophony and increased bronchial whisper. Over bronchiectasic cavities, may be heard the cavernous respiration and whisper. These signs of cavity may be combined with those of adjacent solidification of lung, giving rise to the several varieties of broncho-cavernous respiration. Coarse mucous or bubbling râles are of frequent occurrence, and the accumulation of muco-pus within the cavities may be represented by gurgling.

By means of the foregoing signs furnished by percussion and auscultation the character of the lesions, their situation, their extent, and the physical conditions as regards the presence of morbid products within the air-cavities, are determinable. These lesions are sometimes in striking contrast to the symptoms which represent the general conditions of the patient—the pulse, temperature, emaciation, etc. The symptoms and the physical signs may seem to conflict with each other, owing to the remarkable tolerance of the disease in some cases. To the physical changes which have been stated is to be added removal of the heart from its normal situation. If the seat of the affection be the left lung, its shrinkage may be such that the heart rises into the infra-clavicular region, and the space within which it is in contact with the chest-wall is larger than when the organ is in its normal situation. The latter circumstance is to be borne in mind with reference to the error of inferring therefrom enlargement of the heart. Not only is the area of notable dulness on percussion over the heart greater than in health, but the movements of the organ are remarkably apparent to the eye and touch. If the right lung be affected, the heart may be removed to the right of the sternum, the heart-sounds being heard here with their maximum of intensity. In this abnormal situation the presence of the heart may give rise to a notable dulness on percussion, and its impulses may be both seen and felt.

The differentiation of fibroid phthisis from the ordinary forms of the disease cannot be made with positiveness so long as the anatomical changes are small or moderate in degree and extent. The chief differential point is a greater degree of depression at the summit of the chest than would be likely to occur at an early period if the affection were of the ordinary form. If the affection begin at the base of the chest, it is more likely to be the fibroid variety. In typical cases, when the affection is unilateral and has led to notable shrinkage of the entire lung, taking the physical signs in connection with the evidence of tolerance afforded by the symptoms, it may be differentiated with confidence. Age is to be taken into account in the diagnosis; patients are rarely under forty. The expectoration from time to time of fetid mucus has considerable diagnostic significance.

With reference to the diagnosis, it is to be considered that between the ordinary form of phthisis and typical cases of fibroid phthisis there is every degree of gradation as regards the combination of the anatomical characters of both. There is no sharp line of demarcation between the two varieties. In these intermediate cases to determine by means of the symptoms and physical signs the relative proportion of each variety is not practicable, nor is this a matter of much practical importance. It may be added that the coexistence of chronic laryngitis and of tuberculous disease of the intestine is proof against fibroid phthisis. There is no possibility of the restoration of a lung affected with fibroid phthisis to its normal condition; but the prognosis as regards tolerance, arrest of progress or slowness of progress, and consequently duration of life, is much better than in the ordinary form of phthisis. On this account the diagnosis is of importance. The prognosis is better the nearer the approach to the affection in typical cases. Per contra, the prognosis is less favorable in proportion as the changes characteristic of the disease in its ordinary form are associated with those characterizing fibroid phthisis. If the affection be confined to a lower lobe, it may not extend beyond this limit, and the persistence of solidification of the affected lobe may not be incompatible with good general health. Of these facts the following case is an illustration: Phoebe, aged five years, came under my observation in 1864. There was at that time notable dulness on percussion over the lower lobe of the left lung, with bronchial respiration and bronchophony. She had cough and expectoration, but had not been confined to the bed or house, and her general condition of health was then fair. The treatment consisted of tonic remedies and out-of-door life. I saw her repeatedly during the next two or three years, the physical signs remaining the same, and the general health fair. In 1869 she had chorea and was treated with Fowler's solution. I did not see her again until October, 1871; she had then, and had never been free from, some cough and expectoration, but her general health had been maintained. The signs of the solidification of the lower lobe of the left lung were then present, the upper lobe remaining unaffected. In November, 1874, I noted that I had again seen her and examined the chest. The dulness on percussion over the lower lobe of the left lung continued; there was at this time absence of respiratory sound over this lobe, but the vocal resonance was greater than on the opposite side. The left side was considerably contracted. She had still some cough and expectoration, and there was some deficiency of breath on active exercise. Her aspect was healthful, and she was well developed for her age (fifteen years). Menstruation was irregular. She consulted me for this irregularity, not regarding herself as ill in other respects. About six years afterward I met her in the street, and she accosted me. Her appearance was healthful.³⁶

³⁶ This patient remains in fair health at the present time, May, 1883, nearly twenty years after she first came under my observation.

The treatment in cases of fibroid phthisis differs in no essential points from that in cases of the ordinary form of the disease. The slowness of progress and the long duration show less activity of the tuberculous cachexia. Nevertheless, the cachexia either exists or has existed, and the measures relating thereto which have been considered as belonging to the dietetic and regiminal treatment are alike applicable to both varieties of phthisis. The circumstances which render changes of climate admissible, if not advisable, are much oftener present in the fibroid variety, and there is greater probability of the disease being either arrested or retarded. Medicinal treatment is to be employed with reference to therapeutic indications alike in both varieties of the disease.

The treatment by inhalations to prevent putrefactive changes in the contents of bronchial tubes and in cavities is oftener indicated by fetid sputa in cases of fibroid phthisis. The continuous breathing of the atmosphere of a room containing an antiseptic vapor requires the patient to remain within doors. A more effective method is to make use of a respirator inhaler. A portable and convenient instrument, worn over the mouth like an ordinary respirator, has been devised by W. Roberts and improved upon by H. Curschmann. In this instrument the air which is breathed passes through layers of tow moistened with the antiseptic liquid. The disinfecting agents which have been found efficient are carbolic acid, creasote, oil of turpentine, a mixture of the tincture of iodine and the compound tincture of benzoin and thymol.³⁷

³⁷ Vide article by William Pepper in Transactions of the American Medical Association, vol. xxxi., 1880.

Prevention of Phthisis.

The number of deaths throughout the globe which are caused by pulmonary phthisis vastly exceeds the number caused by any other disease. The etiology of pulmonary phthisis embraces largely causes which can be removed. Hence the disease is to a great extent preventable. Are any comments on these simple statements needed in order that the prevention of phthisis may be regarded as among the most important of the subjects belonging to preventive medicine?

It has been assumed that phthisis involves a predisposition which is in most, and perhaps in all, cases innate. Putting aside all questions relating to an acquired tuberculous diathesis, it may be assumed that the development of the phthisical affection depends in many or perhaps in most cases, more or less, and probably often in a great measure, upon causes which promote the diathetic condition. Now, many of these causes are removable, and if removed phthisis is prevented, and the prevention of a disease which may properly be called a scourge of the human family will be diminished.

Of removable causes may be mentioned humidity of the soil in places of residence; living in small unventilated dwellings; confinement within doors; breathing in close workshops or factories, and in overcrowded rooms at night, an atmosphere deficient in oxygen and contaminated with pulmonary and cutaneous emanations; working underground in mines from which light as well as pure air is excluded; a deficiency of food sufficiently wholesome and varied; impairment of the cutaneous functions from uncleanliness; and want of a proper adaptation of clothing to the climate or season. These are obvious violations of the hygienic requirements for health. It is unnecessary to cite facts to show to what extent these violations prevail in different countries. They are causes which admit of removal, however difficult may be the task. Connected with their removal are other considerations than the prevention of phthisis. But confining the attention exclusively to the latter object, how incalculable would be the saving of life and health were these causes to be removed! Much has been done within the last half century toward diminishing the mortality from phthisis by advancement in pathological and therapeutical knowledge; how much more remains to be done by preventive measures!

The prophylaxis against phthisis must date from birth. An infant should not nurse a mother who is consumptive or whose milk is of poor quality. Care is to be observed in the selection of wet-nurses. All the various articles which are sold under the name of infants' food should be discarded. Many of these are fraudulent; that is, they are not what they purport to be. But admitting that, if properly prepared, they are safe substitutes for milk and the simple farinaceous foods, there can be no guarantee for their proper preparation; and the risk is too great to rely upon articles which cannot be readily tested and for the genuineness of which dependence must be placed on irresponsible dealers.³⁸ There is need of much caution respecting the purity of milk, especially in cities. Much harm is not infrequently done by over-care in children's diet—that is, by denying articles which they crave, and restricting them to those which they do not like. In this matter the instincts are not to be set aside, especially in early life, when perversions of appetite and taste have not been acquired. Not infrequently from undue caution the quantity of food is restricted, and children suffer from insufficient alimentation; this is more likely to occur in our country among the wealthy than among the poorer classes. Other prophylactic provisions pertaining to exercise, out-of-door life, clothing, etc. need not here be considered.

³⁸ Vide "Address by A. Jacobi on Infant Diet," Transactions of the New York State Medical Society, 1882.

In order to combat the various causes which have been named, knowledge of hygienic laws must be diffused among all classes. There is a lamentable lack of information and of interest as regards matters of hygiene among the more intelligent classes. But it is not sufficient to enlighten these: the knowledge must be extended, as far as practicable, to those who, in this point of view, are lower in the scale. Many persons of wealth fall in this category. The causes which are purely personal can be reached only by information diffused by means of publications, lectures, and intercourse with medical men and others. Here is a rich field for missionary labors. To overcome certain of the causes, however, the intervention of legislative authority is necessary. With reference thereto health boards, properly constituted and invested with adequate powers, should be organized in States, counties, and cities. In this way it is practicable by the prevention of phthisis to lessen greatly the rate of mortality.

Protection against the communication of the disease requires to be specially noticed. Occupying the same bed with phthisical patients and sleeping in the same room, if the latter be not enjoined by the dictates of humanity, are objectionable. They are to be objected to on the score of unhygienic influences, physical and moral, irrespective of the doctrine of a tuberculous contagium, and of course still more in view of the probabilities in favor of this doctrine. Care should be taken to exclude from the table the meat of tuberculous animals. In addition to the purity of milk in other regards, it should be ascertained that the supply is not from cows affected with tuberculous disease. Obviously, this is especially of importance with reference to infants who are bottle-fed and in childhood, when generally milk forms a much larger proportion of the diet than in after years. The ventilation of apartments occupied by phthisical patients should be attended to with reference to the possibility of the disease being communicated by the inhalation of particles of tubercle; and it may not be a needless precaution to introduce a disinfectant into the vessels which receive the matter expectorated.

SYPHILITIC DISEASE OF THE LUNG.

BY EDWARD T. BRUEN, M.D.

DEFINITION.—Lesions of the lungs with a syphilitic impress include catarrhal inflammation of the bronchial mucous membranes, chronic inflammatory new formations, which affect especially the connective tissue, producing sclerosis or else gummatous growths.

HISTORY.—From the early part of the eighteenth century attempts have been made to create a word-portraiture representing the peculiar features of syphilitic pulmonary disease as a separate entity. It has been defined histologically and clinically from simple and from fibroid phthisis, or from cases of syphilis in which a damaged state of the general health has fostered the development of phthisis. But the question, Is there a peculiar microscopic and macroscopic anatomy, or a special symptomatology by the aid of which the cause, seat, and dissemination of pulmonary syphilis can be recognized? remains even now but partially removed from the field of debate and conjecture, although unquestionably the syphilitic poison bears intimate relation with various pulmonary processes.

ETIOLOGY.—Predisposing and Exciting Causes.—Syphilis of the lungs is a rare disease as compared with the forms of specific laryngitis, but even here Leman asserts that there is an early simple catarrh of the larynx indistinguishable from the specific catarrhs. Whistler, in recording his observations upon 88 cases of the lesions found in syphilis of the larynx, observes that catarrhal congestions in early laryngeal syphilis simulate the same lesions from ordinary causes. Schnitzler lays particular stress on the association of pulmonary syphilis with affections of the larynx and a specific bronchitis which may occur in the first two months after inoculation. Many other writers on this subject assert that laryngeal and bronchial catarrh attend the period of early skin eruptions, disappearing in consequence of an antisyphilitic treatment.

The rarity of pulmonary syphilis has been further attested by the observations of Greenfield, who states that out of 22 cases of visceral syphilis, only 1 occurred in the lung and 4 in the larynx and trachea: in these cases, while the dura mater and cerebral vessels were extensively diseased, no trace of skin affection could be found. Goodhart has collected from the post-mortem records in Guy's Hospital during twenty-two years 189 cases of visceral syphilis, but in only 38 of these chronic lung disease occurred. Phthisis associated with syphilis is usually a late secondary or tertiary process, which appears from two to five years after the infection; in rare cases ten—even twenty—years have been said to elapse before the supervention of pulmonary trouble. Cases of phthisis associated with syphilis have, however, been described as occurring within the first twelve months after infection. Further investigation may establish these cases of early pulmonary syphilis as attributable to violent systemic infection, or their etiology may be involved in the deterioration of the general health which sometimes occurs. Moreover, one must remember that simple phthisis may more readily be developed in the scrofulous syphilitic, owing to the predisposition of such persons to catarrhal forms of inflammation. In the progress of syphilis there is also a tendency to catarrhal processes through anæmia and damaged general health, which may predispose certain cases to an ordinary type of phthisis. The origin of the new formation in both tubercular and syphilitic phthisis is similar—viz. the arterial, lymphatic, and the peribronchial sheaths, spreading thence to the interlobular connective tissues. It is therefore not surprising that it has been difficult to differentiate the tubercular from the specific forms of phthisis, and Goodhart asserts that there is no histological difference between syphilitic and tubercular phthisis, except that the former is more vascular.

We may assume that true pulmonary tuberculosis may be associated with syphilis, but preserves its own pathological characters; that, although we are ignorant of the exact differential histological changes, there is sufficient evidence to show that there is a distinct association between syphilis and pulmonary disease; and that syphilitic phthisis is commonly interstitial. Whether the relation be one of cause and effect, or whether the process is simply a modification of ordinary tubercular phthisis, it is impossible at present to determine. The final adjustment of the theories concerning the specific etiology of tubercular phthisis may throw further light upon the etiology of syphilitic phthisis. That gummata may be found in the lungs is a well-established fact, and by some authorities is not considered rare.

The discussion of the etiology has already indicated the relation of the predisposing and exciting causes to pulmonary processes in connection with syphilis. In certain cases of syphilis the antecedent of pulmonary changes is a laryngeal or bronchial catarrh. The relation which an active virus in the blood sustains to the process is still subject to debate. Hutchinson writes as follows: "If the infected blood were the cause of the local phenomena, it is almost certain that such phenomena will be symmetrical, because the blood is equally supplied to both sides; such is the case during the secondary stage. If, however, the symptoms result from tissue-conditions, and the blood is at the time of the outbreak free, then there is a considerable probability that local influences may take a large share in evoking them, and they will be asymmetrical—evoked by some local cause."

The existence of gummata, then, does not necessarily show that there is any active virus in the blood, because their formation is sometimes symmetrical, sometimes asymmetrical.

PATHOLOGY AND CLASSIFICATION.—The lesions of pulmonary syphilis may be divided into four classes: (a) early phthisis, associated with principal interlobular proliferation; (b) advanced syphilis, in which gummatous or allied formation exists; (c) simple phthisis, developing in consequence of impaired general health induced by syphilis; (d) inherited or congenital syphilis, occurring in infants.

(a) The pathological process in the majority of cases in the adult is interstitial new formation, very often evoked by antecedent catarrhal inflammation. At first small spindle-shaped and round cells appear and develop into connective tissue, among the fibres of which blood-vessels are freely produced; the septa of the alveoli are thickened and the alveoli themselves compressed. In any morbid process in the lungs, such as tubercle, sarcoma, or cancer, the alveoli act as the inter-fascicular spaces of the connective tissue. In the same manner in syphilis the alveoli of the lungs are always in the later stages, and sometimes primarily, more or less filled with small cells, which, surrounded by the newly-formed connective-tissue fibrous framework, gives the appearance of some of the forms of simple phthisis. The smaller bronchi become narrowed, and perhaps occluded, by the pressure of the new growth which develops along their lumen. Occlusion of the bronchi may also be caused by enlargement of the bronchial glands, which is one of the incidents of the syphilitic pulmonary process.

If we endeavor to nucleate the peculiar impress attributed to early syphilitic pulmonary processes, we find much that is vague. The vascularity and advanced grade of organization of the new growth are considered by Greenfield and Goodhart to be characteristic when compared with tubercular consumption, in which the original growth is bloodless and the tendency is to retrograde metamorphosis. Green and Virchow suggest that the origin of syphilitic diseases of the lungs is distinctive in this respect, that while in the ordinary forms of phthisis the fibroid is secondary or coequal in its development with changes in the alveoli and alveolar wall, in syphilis there are primarily interstitial changes. In chronic bronchitis the fibroid thickening proceeds from the bronchi. Wagner, however, maintains that implication of the alveolar wall is as common in syphilis as in ordinary phthisis.

In the general pathology of syphilis the change in the intima of the blood-vessels is characteristic: this has not yet been demonstrated in the lung, but merely the general thickening of the external coat of the vessels. When entire vesicular consolidation and breaking down occurs, the process is similar to ordinary phthisis, and indistinguishable from it.

(b) In the gummatous stage the same formation of cellular and connective tissue is found as in the diffused form, with which gummata are often associated. Gummata may originate anywhere in the intervesicular tissue, usually near the visceral pleura. Sometimes they are formed near the roots of the lungs, intimately connected with the blood-vessels and bronchial sheaths. They may also be formed in the deeper layers of the costal pleura or upon the periosteum of the ribs. Owing to the peculiar anatomical formation of gummata, their subsequent history is one of combined caseous and fatty degeneration. These centres of softening may communicate with a bronchus, more or less rapid evacuation of the mass may occur, and a cavity be formed which often enlarges as the gummata break down. Contraction may ensue, leaving a small fibrous scar with cheesy cretaceous deposit, or the gummata may point externally, with or without the appearance of inflammation in the adjacent tissues, or they may remain stationary for an indefinite period. In some cases the pulmonary new formation may be a combined interstitial, gummatous, and catarrhal process; but, as a rule, the fibroid process of syphilis in the earlier stages is not accompanied by the filling of the alveoli with catarrhal cells. Gummata developed in or near the pleural sac may increase in size, and by compressing the lung simulate pleural effusions.

(c) The morbid anatomy of cases in which simple phthisis develops in consequence of the vulnerability of the pulmonary tissues to the exciting causes of bronchial inflammation requires no special consideration.

(d) Interstitial inflammation, gummata, and enlargement of the bronchial glands have been found in the syphilitic foetus and in very young children. It is also claimed that syphilitic disease of the lung may be one of the forms of tertiary disease which develop in children between the second dentition and maturity. Virchow and Lebert have described pulmonary gummata in children suffering from inherited syphilis. Depaul gives the cases of two children with pemphigus who had soft puriform nodules or collections scattered through the lungs. In the infant lung the highly cellular character and ready reversion to the embryonic type of structure would naturally lead to exuberant growth and rapid diffusion of the morbid process, which could not occur in the more fibrous, less cellular lung of the adult. Hence the slower growth in the latter establishes the more fibrous and limited extent of disease: in other respects the origin and distribution of the growth are identical in both cases. In the infant enlargement of the bronchial glands and bronchitis leading to broncho-pneumonia, or an unusual proliferation of epithelium in the alveoli, is more frequent than in the adult.

MORBID ANATOMY.—In the earlier stages of pulmonary syphilis the macroscopic appearance of the lung is firmer at the seat of deposit than elsewhere. It is also heavier and has a smoother surface. The infiltrated parts are grayish-red or grayish-yellow, smooth, and homogeneous. Sometimes the appearance resembles pale-whitish patches invading districts of the lung. The hyperplastic material becomes converted into a tough, contracting, fibrous tissue, which radiates through the lung, drawing together the bronchial tubes and flattening them, possibly even to obliteration. The entire lung may be involved, but the changes most frequently proceed from the hilus of the organ into the interior, following the track of the bronchial radicles and the bronchial and pulmonary arteries. The lesions frequently develop near the visceral pleura, where there is more connective tissue. This accounts for the depressed puckered scars which are found on the pleural surface.

The macroscopic appearances in specific pulmonary disease differ, according to Goodhart, "both from a chronic pneumonia and from that solidification ensuing after contraction of the lung from old pleurisy, in that it is less evenly distributed, and generally less widely spread over the lobe, than they. It is nodular, rather diffused, and more symmetrical than unilateral. From miners' phthisis the appearance differs in the absence of the extreme dilatation of the bronchial tubes and more solidity from greater growth. The tissues involved are more tough and less granular than red or gray hepatization." It is possible to differentiate other forms of fibroid phthisis by noting, in addition to the above points, the presence of the syphilitic process in other viscera, and by comparing the clinical records with the post-mortem examination.

Syphilitic lesions may be found in any part of one or both lungs, but their localization at definite points in the lungs, leaving the balance free even when the lesion has proceeded to formation of cavities, may be characteristic. There is, however, a wide division of professional opinion upon the subject of the localization of the process in syphilitic pulmonary disease; some claiming the middle lobe, some a symmetrical lesion at the apices, others lesions at a definite point elsewhere than at the apices. If the pulmonary lesions are introduced by an attack of pleurisy, the process in the lungs is usually located at one or both bases. Some, however, locate the disease at the base, without mentioning an antecedent pleurisy.

Gummata are more frequently situated in the middle or lower lobes of one or both lungs, and are defined by a boundary layer of fibrous tissue. Fibroid development may ensure their adhesion to the visceral and costal pleura. They are gray or yellowish-gray, hard, well-defined nodules, of varying size and number, occurring as single large masses surrounded by normal or compressed lung. In the centre is found a diffluent material, not unlike the centre of a scirrhous nodule, similarly enclosed in a limiting fibrous investment from an inch to many inches thick. In the condition of the neighboring pulmonary substance a difference may be observed between gummatous and tuberculous nodules: the latter occur in more numerous masses, usually small, and the entire lung is more or less diseased; while in syphilis extended districts of non-affected lung occur in the neighborhood of gummata. Whenever gummatous lesions in the lungs exist a history of pustular eruptions, laryngitis, arterial lesions—in fine, some indication of general systemic syphilitic poisoning—can always be found. Fournier thinks there are five anatomical points of distinction between syphilitic gummata and tubercle: "1. Tubercle involves the upper part of both lungs; gummata one lung, and may be limited to a portion. 2. Gummata are few as a rule, solitary; tubercles sooner or later become confluent. 3. Gummata are larger than tubercles, never miliary in form. 4. Gummata are always yellow or white, never transparent like miliary tubercle. 5. Until softening takes place gummata are of more equal consistence than tubercles, and if they soften do not break down, wholly owing to the capsule. Histologically, there is no difference in structure." Gummatous formations may be found on the pericardium and heart and in the thoracic and abdominal walls. Clinically, the most important pathological feature is that large districts of healthy lung are interposed between the affected districts; this is not so in ordinary phthisis.

Bronchial Lesions.—The syphilitic like the scrofulous are predisposed to catarrhal inflammation, and this may spread down the bronchial tubes, giving rise to a general bronchitis; a coexistent laryngitis may or may not exist. Enlargement of the bronchial glands is frequently combined with the syphilitic pulmonary process. When the glands are enlarged they present a firm pigmented character, varying in size from a hazelnut to an egg, and the connective tissue surrounding them is usually infiltrated. Subsequently, owing to the pressure of the mediastinal growths, the bronchi are narrowed and more or less occluded; the same effects are occasioned in the smaller bronchi by the pressure of the new growth which develops along their lumen. The effects of bronchial narrowing or occlusion produce serious mischief in the lungs proportioned to the degree of obstruction. By the retention of the bronchial secretions the air-supply to the vesicles is interfered with; emphysema with or without asthmatic symptoms or atelectasis may ensue. Further, the results of bronchial narrowing affect the circulation through the lungs, and in combination with atelectasis very intractable local bronchitis may be developed; and, with or without atheroma, hemorrhagic infarctions may occur, with a form of pneumonia which has been described by Fuchs as apneumatosis. The narrowing of the bronchial tubes in specific fibroid phthisis affords a means of differentiating this disease from non-syphilitic fibroid phthisis, in which the tubes are widened. Cases have been reported of nodules of syphilitic new formations in the mucous membrane of the superior and inferior extremities of the trachea and larger bronchi. The nodules ulcerate, and in healing cicatricial bands of fibrous tissue are formed which cause contraction of the tracheal tube transversely or diminish its length. These lesions resemble tuberculous ulceration, but they differ in the nature of the initial neoplasm by the formation of cicatricial tissue and by the tendency to stenosis of the tracheal tube. The cutaneous syphilides, mucous patches, the exostoses of the bones of the cranium help to demonstrate the connection of the marked cachexia with syphilis rather than scrofula.

SYMPTOMATOLOGY.—As the pathology of syphilitic pulmonary processes is intertwined with the pathology of many other forms of phthisis pulmonalis, so the symptoms must be common to those obtaining in other forms of pulmonary disease. They are insidious and gradual in their development, and may be classified as the subjective, the physical signs, and the objective phenomena. The subjective symptoms may be present without noticeable departure from an appearance of health. There may be difficult respiration with more or less dyspnoea, especially in the mornings and evenings, besides a sense of heaviness and oppression in the chest, with a feeling of inability to inflate the lungs. These symptoms may be increased on exertion, respiration becoming wheezing, with imperfectly-developed asthmatic attacks. Hoarseness, with varying degrees of aphonia, more or less dysphagia or unequal pupils, may be present. Nearly all of these symptoms may be accounted for as indicative of mediastinal pressure or irritation of the pneumogastric nerve by the enlargement of the bronchial glands. The catalogue of phenomena may be present in whole or in part, and the intensity of their manifestations may vary from time to time in the history of a single case. If the bronchial glands are much enlarged, a sense of discomfort, oppression, and uneasiness at the root of the neck may be experienced, which increases until actual pain is felt, located in the back between the scapulæ, but sometimes radiating through the intercostal nerves around the chest. Cough, as a rule, is an early symptom, usually dry, paroxysmal, and associated with dyspnoea, or there may be bronchial catarrh, with a relative amount of expectoration. Syphilitic disease of the larynx may occur coequal with the pulmonary trouble, and some of the above symptoms may be thus explained and many others added. Rheumatic and nervous symptoms, including sleeplessness and deterioration of the blood-crasis, may testify to the syphilitic infection of the blood.

When a physical examination of the chest is instituted, thickening of the head of the periosteum of one or both clavicles, substernal tenderness, thickening of the tibial periosteum, are usually detected. Prominent among the physical signs are the evidences of enlargement of the bronchial glands. According to Guéneau de Mussey, percussion over the spinous processes of the cervical vertebræ in the course of the trachea reveals in a healthy subject a distinct tubular sound down to the point of bifurcation of the trachea at the level of the fourth dorsal vertebra. Opposite the fifth and downward we get the lower-pitched pulmonary resonance. When the tracheal and bronchial glands are enlarged, the tubular sound over the upper dorsal vertebra is replaced by dulness, which may contrast sharply above with the tracheal and below with the vesicular resonance.

The respiratory murmur will be feeble in volume and limited to inspiration, especially over the interscapular region. Over one or the other bronchus the respiratory murmur may be more high pitched than in health, and slightly exaggerated on one side or at the base of the chest. The rhythm is often jerky and paroxysmal; the paroxysms are more or less constant, but are liable at times to increase.

The additional physical signs in syphilitic phthisis, unassociated with gummata, are those shared by other forms of fibroid phthisis, and do not require particular description here, as increasing dulness, varying degrees of bronchial breathing, and bronchophony. A peculiar alveolar rustle, resembling the sound produced by the rumpling of wall-paper, has been alluded to as characteristic.

Inspection or palpation sometimes reveals changes in the contour of the chest, with displacement of the movable thoracic viscera, as in fibroid phthisis. When cavities occur, the physical signs necessarily correspond to those of other varieties of phthisis at this stage.

When a gumma is large enough to be recognized by physical examination, one finds dulness or flatness on percussion, confined to a section of the chest, and not occupying its semi-circumference, as in pleural effusions. The vocal fremitus is suppressed in proportion to the size of the gumma. The respiratory murmur is abruptly cut off over the area of flatness, but it may be only distant bronchial breathing. The vocal resonance is absent or is distant bronchophony. Around the gumma the respiratory murmur is usually very feeble or scarcely audible, generally without râles unless they are due to neighboring congestion. The percussion resonance is good or exaggerated. Proportionate vicarious functional activity prevails in the opposite lung. If the gumma be large, the heart's impulse may be displaced to the left or right, and dyspnoea may occur as in case of pleural effusions. In this stage, owing to irritation of the bronchial mucous membrane, there may be expectoration of a tough, glairy mucus, or as a gumma softens the expectoration may become purulent.

The objective phenomena vary: the chest is often well developed, the body fairly nourished, and constitutional symptoms of a severe character may be wanting. The patient may be capable of hard physical labor, even though a considerable part of the lung be affected. Moxon relates a case of a man "employed in carrying sacks of grain who was suddenly killed, and who had fibroid infiltration of a great part of the left lung and part of the right, and besides scars in his liver and testes." But in some cases the complexion is pallid and waxy, indicative of cachexia associated with digestive disorders, with night-sweats, and a variable but low thermometrical record. Usually, the progress of the disease is slower in syphilitic than in tubercular phthisis, but when the systemic poisoning is grave and many other organs are coincidently involved, the progress is more rapid; but the process peculiar to syphilis is often past, and the patient suffers from simple catarrhal phthisis with formation of cavities and softening gummata. Diarrhoea and night-sweats are said to be less frequent than in ordinary phthisis, and the pulse is slower. Hæmoptysis occurs infrequently, because the process in the lungs is chiefly fibroid; but it is possible through the rupture of newly-developed blood-vessels in the new formation in the lung or hemorrhagic infarction through the rupture of atheromatous vessels.

DIAGNOSIS.—This depends mainly on the history of the cases, the prior or coexisting syphilitic lesions, especially laryngeal processes, cutaneous syphilides, exostoses, perforation of the palate, substernal tenderness, and the thickening of the tibial periosteum or that of the head of one or both clavicles. Family immunity from phthisical tendency, recovery from lesions usually incurable if they have any other than a specific origin, are suggestive of pulmonary syphilis. If a patient retains flesh and strength beyond the natural expectation considering the serious lesions of the lungs, the fact is of relative importance when considered in connection with the other diagnostic features. The distribution of specific lesions is variously located by different authors. Grandidier found induration affecting the middle lobe of the right lung in 27 out of 30 cases believed by him to be specific phthisis; the surrounding lung contained large areas free from disease. This tendency to localization in portions of the lungs, leaving large areas free from disease, is of value in diagnosis.

PROGNOSIS.—The prognosis is involved in the discovery of syphilis as the cause of the disease and on the subsequent appropriate treatment. Grave and important specific lesions, according to some authors, have yielded to the resources of art. Fournier has recorded a case where "dulness at the summit of the left lung was extensive and signs of a cavity distinct. After six weeks of antisyphilitic treatment recovery was almost complete. In this case the presence of a phagedenic ulcer of the foot was the only sign that suggested syphilis, the symptoms of the pulmonary affection being identical with those of tubercular phthisis." The principles presiding over the prognosis of the various stages of pulmonary diseases in general are applicable to syphilitic pulmonary processes.

TREATMENT.—When a case of pulmonary lesion presents itself, unless the existence of tuberculosis be demonstrated, we must ascertain if the symptoms can possibly be due to syphilis, and the line of treatment indicated in any single case must be based upon an estimate of the prominence of the specific process. The ravages of syphilis, however, often produce such loss of substance in the lung that the lesions are irreparable, and therefore we cannot always accomplish the brilliant results which usually attend an antisyphilitic treatment. If there is evidence of enlarged bronchial glands, in addition to other measures local counter-irritation is useful by means of the biniodide of mercury ointment, 16 grains to the ounce, and applied for a continued period, or a preparation of iodine with croton oil may be tried. In the main, the general principles of treatment correspond with those recognized in similar forms of pulmonary disease of a non-specific etiology.

PNEUMONOKONIOSIS.

BY EDWARD T. BRUEN, M.D.

DEFINITION.—A generic term applied to pulmonary diseases due to the inhalation of particles of irritating dust.

SYNONYMS AND CLASSIFICATION.—The synonyms and classification of pneumonokoniosis have been based upon the character of the dust inhaled, using such terms as anthracosis ([Greek: anthrax], coal), disease due to coal-dust; siderosis ([Greek: sidêros], iron), due to metallic dust; chalicosis ([Greek: chalix], gravel or pebbles), due to mineral dust; tabacosis, due to tobacco-dust; and byssinosis ([Greek: byssos], cotton), due to cotton fibre and dust. A more imperfect classification has been derived from the avocations of the sufferers; for example, miners' phthisis, Sheffield grinders' rot, potters' consumption and asthma, freestone-hewers', masons', or millers' lung.

HISTORY.—From the early experiments of Cruveilhier, who injected mercury into the system and subsequently noted the pulmonary changes, down to the experiments of the present day, evidence has accumulated to show that inorganic irritant materials are capable of exciting inflammatory new formation in the lungs. The difference between the changes produced in the lungs by experimental processes and those occurring after the inhalation by artisans of inorganic materials consists in degree rather than in essential character. In pneumonokoniosis the pulmonary processes are gradually developed, and consequently the ensuing changes in the tissues represent those usually associated with the more chronic forms of pulmonary lesions, and may not only occasion phthisis, but during years of life may cripple the sufferer by engendering chronic catarrhal processes in the mucous membranes, complicated by emphysema or asthma.

ETIOLOGY.—Predisposing Influences.—Atmospheric dust is composed of organic and inorganic matter, and both have been demonstrated by many admirable experiments to be very widely diffused in the air we breathe. In most instances the injurious action of inorganic dust is augmented by the conditions of imperfect ventilation under which it is inhaled, because the amount of dust deposited in the lungs is thereby increased. Illustrations of this fact can be found in various avocations, particularly among miners. The injurious action of dust inhaled when there is imperfect ventilation is increased in proportion as there is deprivation of sunlight, both conditions tending to lower the vitality of the artisan. Again, the rigor of confinement of parents engenders a sickly or scrofulous constitution which is transmitted to their offspring, causing great mortality among the children of artisans, especially where they, in turn, are subjected to unfavorable environment.

When work is performed in constrained or stooping positions, or when proper inflation of the chest is not secured, the liability to pulmonary disease is increased.

The foregoing conditions having been considered, the injurious action of dust upon the lungs is in proportion to the quantity deposited in them. The entrance of dust is, however, physiologically opposed by the action of the pulmonary cilia, although the resistance is frequently ineffectual. This inefficiency may be owing to the quantity of dust inspired or to deficient tissue-integrity in general upon which the ciliary action depends in inverse ratio.

Exciting Causes.—These vary materially in different avocations. The most injurious industries are those in which the various forms of grindstones are used, or those trades which necessitate labor in an atmosphere loaded with particles of steel, iron, or flint. In London, where millstones are made from French burr, a peculiarly hard flint quarried on the Marne to the east of Paris, and more liable to chip from its hardness and dryness than flint quarried in other places, the mortality among the artisans is said to be very much increased. Peacock, who has investigated this subject, asserts that in certain manufactories of this class the average age of those engaged is very low: of 23 apprentices the average age was twenty-four, and the longest period during which the occupation could be followed was thirteen years. The same author has also demonstrated the presence of silicious particles in the lung-tissues. In the pottery districts of England the death-rate from pulmonary diseases is greater among those who work at that avocation than among the other inhabitants.

The study of the effect upon the lungs of the inhalation of coal-dust is very important. In the coal-mining region of Cornwall the deaths from chest diseases among miners is double that of males in the community at large; the mortality of those working in lead-mines is also very great.

The black spit of pitmen, examined under the microscope, is seen to consist of mucus enclosing finely-divided particles of coal, frequently presenting the special bands of the particular coal in which the subject of the disease may have worked. The fact that coal-dust may enter the lungs in the act of breathing is corroborated by Rindfleisch, who, reporting for Traube a post-mortem made in 1860, found in the fluid expressed from the parenchyma of the lung "one of the dotted cells of coniferous wood entirely carbonized, in which he was able to count seven pores close together. This particle of charcoal-dust equalled half the diameter of an alveolus." Inhaled particles of dust first penetrate the bronchial tubes and infundibula, and, entering the alveolar parenchyma, mix with the general current of extravascular fluid, together with which they ultimately tend to reach the lymphatic vessels. On their way they must occasionally meet with corpuscular elements which have the power of permanently adopting small solid particles into their protoplasm: foremost among such elements are the stellate corpuscles of the connective tissue, next the migratory amoeboid cells, which are found in the connective tissue of the lungs as well as elsewhere, and which carry the black pigment with them wherever they go. The residual portion which escapes, being arrested by cells on its way through the lymphatic system, is carried to the root of the lung and enters the lymphatic glands of the mediastinum; here the granules meet an obstacle to their further progress, for the countless lymph-corpuscles with which the glands are stored are ready to take up as many of the charcoal particles as can by any possibility be accommodated in their protoplasm. We may conclude that the influence of inhalations of coal-dust varies in different cases, but may be considered as prominent among the exciting causes of pneumonokoniosis.

The charcoal-grinders and carriers, chimney-sweeps, moulders, iron and glass polishers, and the workers in mother-of-pearl, all suffer more or less from destruction of lung-function. Deposits of oxide of iron have been found in the lungs of operators who have for years used this substance as a polishing pigment. Merkel reports the case of a man who was employed to clean the surface of oxidized iron by scrubbing it with sand: his expectoration was grayish-black, and was found to contain small grains of magnetic oxide of iron; the lungs were found to be indurated with cavities at the apices.

Many other instances of dusty avocations may be mentioned as exciting causes. The polishing of brass is sometimes effected by rollers made of canton flannel which revolve with great velocity, filling the air with fibres of cotton which are capable of acting as mechanical irritants.

In the sizing process in some cotton manufactories the material is often adulterated with clays or some sort of salt to lessen the glutinous qualities of the flour or tallow, and although the process is carried on in damp rooms to lessen the brittleness of the size, dust prevails, causing irritation of the nose, eyes, and throat. Some interesting observations have been made on this subject by James Y. Simpson, who has especially investigated the hygiene of woollen manufactories. He suggests that these artisans are comparatively healthy because of the oil absorbed while running the machines. In the manufacture of cotton it has been found that in mills where cotton containing dust and dirt is used, as the East India varieties employed in England during the American War, the respiration was affected, and the expectoration of numbers of operatives contained slaty-colored matters, found, on microscopic examination, to contain cotton fibres.

Bakers who have to deal with highly-dried biscuit flour suffer more than those using ordinary brands of flour. But when all has been said, when we consider how many persons live permanently in an atmosphere specially surcharged with dust without showing a symptom of a morbid state of the respiratory organs, and since the epithelial cells of the lungs can contain particles of coal, it demonstrates that foreign bodies may penetrate the lungs without always inducing serious changes. Mineral matter has been found by Riegel in the form of silica in the lungs of a boy aged four, constituting 2 per cent. of the ash left after incineration. In those of a day-laborer aged forty-seven it amounted to 13 per cent., and in those of a woman cook sixty-nine years old it reached 16 per cent. Accepting these figures as accurate, they show a progressive accumulation in proportion to age among individuals breathing dusty atmosphere. Traube thinks that the changes in the lungs of coal-miners may not be produced by the accumulated particles of coal, but by the chemicals contained in coal, and not found in charcoal. In a discussion of this question in London in 1869, Wilson Fox thought it remarkable that in proportion to the number of persons exposed to the inhalation of irritating substances the cases of phthisis were comparatively few, and suggested that a diathetic condition might underlie the entire pathology.

In summing up the evidence bearing on the predisposing and exciting causes of pneumonokoniosis we cannot overlook the recent discoveries of Koch and his collaborators, but may conclude that although there is increasing evidence tending to show that the bacillus tuberculosis is always present in tuberculous pulmonary processes, yet its exact etiological relation cannot be considered as established. We may still hold that when large amounts of inorganic materials are taken into the lungs, particularly if the ventilation or hygienic conditions under which the dust is inhaled are imperfect, certain diverse pulmonary processes are apt to ensue. That phthisis can be thus produced is undoubted, but the nature of the irritant has less to do with the type of the resulting disease than has an inferior or scrofulous constitution, inherited or acquired, or the indulgence in habits directly damaging to the health; since an unvarying specific cause would be more destructive than has been proven, large numbers of individuals escaping any serious effects when equally exposed.

PATHOLOGY AND MORBID ANATOMY.—Whatever be the dust inhaled, the pathological processes set up by it partake of the same essential character, though differing in intensity and in the division of pulmonary tissue principally involved, while the combined inhalation of organic particles may essentially modify the results produced. Examination of the lungs has revealed deposits of various inorganic materials which have been inhaled, such as oxide of iron, indigo, snuff, silica, coal, carbon, etc. A black discoloration of the pulmonary tissue, with or without induration, enlargement, and blackening of the bronchial glands, may, however, have its origin in morbid changes independent of inhaled matter, such as defective elimination of carbon and carbonic acid, with a sort of precipitation of carbon within the tissues.

The black coloration of the lungs, especially in miners, is also partly due to the deposition of a true hæmatoidin pigment in granular form, caused by the irritating particles inhaled setting up changes in the bronchial or pulmonary tissues, resulting in the escape of the coloring matter of the blood either by rupture of capillaries or from transudation of serum. Similar discoloration is often found in cases of chronic bronchial processes independent of a dusty etiology. The most penetrating form of dust is the silicious, on account of its hard, vitreous character. German authors comment on the difference in the power of penetration of mineral coal-dust as compared with charcoal-dust, because the spiculæ of the former are elongated, sharpened splinters. The coloration of the lung from clay-dust does not diffuse itself so readily as coal-dust, yet it possesses more irritating properties and creates more damage.

The morbid anatomy of pneumonokoniosis includes nearly all the pathological processes incident to the pulmonary tissues. The bronchial lesions are those of chronic bronchitis, with thickening of the bronchial mucous membrane, associated with possible ulceration and bronchial dilatations, forming bronchiectasic cavities. These cavities are caused by combined softening of the bronchial tissues with traction from without by the newly-formed fibrous tissue. The bronchial glands may be enlarged to the size of walnuts, and are often perfectly black and gritty on section. These enlarged glands may occasion, through pressure, many changes in the pulmonary tissues. The effect of this pressure is especially manifest in the lymphatic system. The lymph-circulation is further crippled by the accumulation in the lymph-channels of the inhaled inorganic materials. These interferences with the lymph-circulation may be followed by exudation or lobular and interlobular formation of tissue; secondary to these changes the pressure upon the vesicles may cause local congestions, exudations, and even hæmoptysis. By one or all of these processes the expansile power and elasticity of the lung are slowly depreciated, emphysema develops, intertwined with the lesions of acute, subacute, or chronic bronchitis, fibroid phthisis, and atrophic emphysema. Nodules of cretaceous matter can be recognized through the lungs, which are black in anthracosis or gray in silicosis. These nodules occur from the size of a pin's head to that of a pea, and are especially found in the lungs of glass-cutters, sandstone-workers, and grinders. In these cases they consist in part of iron and in part of stone. In sandstone-workers they are composed of silica; the organ feels nodulated, very fibrous, and in some cases actually gritty. The predominant form of pulmonary change is fibroid; hardened districts of advanced cirrhosis occur measuring two inches and upward in length and width, and in depth and thickness nearly as much. These may be rounded, but are not separable from the adjacent structures, the condensation of the tissues lessening without a defining line. On section they appear tough and leathery, most pronounced along the anterior edges of the lungs, and are apt to be covered in by thickened pleura. If the nodules previously alluded to are encysted, fibrous prolongations extend from these cysts into the substance of the lung, the thickening of the lung being greatest in the septa, on the pleural surfaces, and along the course of the bronchial tubes. Sometimes subacute or chronic pleural processes coexist. The caseous masses found in tubercular fibroid phthisis are infrequent in pneumonokoniosis, but in the latter process the pathological changes may be identical with the ordinary forms of phthisis, especially in those individuals who are predisposed to pulmonary affections and those in whom the pathological processes are rapid.

In anthracosis the lung is large and increased in weight; the surface of the pleura has a bluish-black color, contrasting with the coal-black color of the lungs, which are universally pigmented and contain nodules of pigment. When only small quantities of pigment are present, it presents the appearance of dark lines running between the lobules; on section these are very hard and distinct, being about the size of a millet-seed. They are universally distributed throughout the lung, and in some places appear like small masses of charcoal. Upon squeezing the organ a blackish fluid exudes which stains the hands, but the discharge which is found lying in the bronchial tubes is often yellow and muco-purulent, although the sputa during life is more or less discolored. When the distribution of the discoloration of anthracosis is investigated, it is found to closely correspond with the lymphatic distribution of the lung, and the conclusion is probably well founded that all other irritating particles pursue the same course through the pulmonary tissues. When particles of coal or pigment enter the bronchi with the air, they cannot pass through its mucous membrane, because the basement membrane and fibrous coat underlying it present an obstacle to their lodgment, whilst the cilia of the epithelium tend to prevent their retention in the bronchi; they therefore enter the vesicles, and may be found sticking to the walls. In this way the exemption of the bronchi from pigmentation, even down to the smallest ramifications, can be explained. The interlobular septa ate also the seat of great pigmentation. The germinating epithelium elevates the cells slightly above the surface, and in the interspaces between them the pigment insinuates itself, and thus enters the underlying plasmatic or lymphatic spaces; or the pigment may be incorporated into the epithelial cells, which transfer it to the underlying lymph-space. Once the pigment has found entrance to these lymphatic channels, it is carried by them through the lymphatic vessels in the sheath surrounding the bronchial tubes and the small branches of the pulmonary artery, and in the interlobular septa to the bronchial glands. In this manner the special distribution of the coloring matter in these situations is explained. The special deposit around the small branches of the pulmonary artery is owing to the double set of lymphatics, the peribronchial and the perivascular, which form an anastomosis. The perivascular set is the larger; consequently the pigment passes into them more readily, forming the nodules. Pigment is also found in small quantities around the bronchi, which can be accounted for by the anastomosis of the lymphatics. The bluish-black appearance of the pleura and the distribution of the pigment only in the deeper layers of the visceral pleura are susceptible of a similar explanation, because the deeper layers of the pleura contain lymphatic vessels which are directly continuous by means of the lobular septa with the large perivascular branches of the lymphatic system.

The consequences of the obstruction to the lymphatic and pulmonary-artery circulation may be very serious. In grave cases the lung breaks down, forming a gangrenous-like cavity, which differs from an ordinary cavity in not being rounded; it is more like a gangrene or slough. In a few cases the pathological appearances indicate phthisis, chiefly interstitial, with formation of cavities; sometimes traces of cavities are found which have cicatrized. More commonly oedema is developed in the lung and the bronchial passages. As a consequence of combined bronchial irritation from continuous inhalation of inorganic particles, and the consequent oedema, a continuous germination and shedding of the bronchial epithelium—a chronic bronchitis—associated with emphysema, is maintained. The mechanical cause of this bronchitis—more or less impediment to the vascular and lymphatic circulations by the pigment deposit—is capable of explaining the persistence of various forms of bronchial processes in anthracosis and in other forms of pneumonokoniosis after the patient has ceased working in a dusty atmosphere.

SYMPTOMATOLOGY.—Pneumonokoniosis does not present a special symptomatology. The course of the various morbid processes is insidious and slowly progressive: the development of any of the forms of pulmonary disease depends largely upon the degree of exposure to the exciting causes, or the inherited tendencies, or the susceptibility to influences liable to diminish general vitality or affect the personal hygiene.

The earliest objective symptom of pulmonary lesion is cough, especially recurrent in winter, accompanied by expectoration, which is whitish, frothy, or stringy in character. Gradually the physical signs, taken together with the symptoms, indicate the various forms of bronchitis, acute, subacute, or chronic, sometimes associated with emphysema, bronchorrhoea, or bronchial dilatation. In other cases the symptomatology is that of asthma, either purely spasmodic or secondary to emphysema or cardiac degeneration. In true anthracosis dyspnoea is a marked symptom, and perhaps the accumulation of pigment may interfere with the oxygenation of the blood, or dyspnoea may be due only to an emphysematous pulmonary tissue. The sputa will be black so long as the subject is working in an atmosphere loaded with pigment.

Fibroid phthisis is frequently associated with atrophic emphysema, and the clinical history corresponds with that which is commonly observed in these diseases. Hæmoptysis is rare, but if it occurs it suggests the addition of some tubercular element; a purulent nummular sputa is a suspicious sign of similar import. The symptoms and physical signs of dry pleurisy are to be expected whenever any form of the phthisical process supervenes. The cavities in the lungs are usually bronchiectasic, unless tubercular phthisis occurs as a complication, and the physical signs need no comment. Subacute and chronic laryngitis with ulceration complicate certain cases, particularly those which have inherited or acquired a tubercular tendency.

DIAGNOSIS.—The diagnosis involves a comparative examination of the etiology and the physical signs.

PROGNOSIS.—The prognosis depends very largely upon the withdrawal of the sufferer from an unhealthy environment. In each single case the inherited tendencies, the personal constitution and habits, must be the basis for an opinion upon the gravity of the pulmonary processes and the possibilities of restoration to health. The progress of the disease may be materially retarded or arrested by withdrawal from the occupation involving the inspiration of dust, and restoration to comparative health after years of invalidism is possible for these victims of dusty avocations, even after serious damage has taken place in the lung, if suitable hygienic conditions can be obtained.

TREATMENT.—The treatment of pneumonokoniosis divides itself into the prophylactive and the curative. In works devoted to the hygiene of occupation careful directions are given in reference to methods designed to prevent the dust from entering the respiratory passages. This is partly accomplished by the use of masks or respirators, which possess the obvious disadvantages of clumsiness and interference with respiration. Various devices may be employed in different avocations to prevent the generation of dust, but the most practical plans consist in thoroughly ventilating the atmosphere, and thus preventing the dust from reaching the artisan. Aside from these, the management of the various pathological conditions must be based upon the general principles which govern the treatment of pulmonary processes.

CANCER OF THE LUNGS.

BY EDWARD T. BRUEN, M.D.

DEFINITION.—A malignant disease affecting the pulmonary tissues. (Vide also MEDIASTINAL DISEASE.)

SYNONYMS.—Fr. Carcinome du poumon; Ger. Lungenkrebs.

ETIOLOGY.—Carcinomatous disease affecting the lung-tissue is exceedingly rare as a primary process, and exhibits only a feeble inclination to inoculate other portions of the body. In the majority of cases the mediastinal glands are first affected, or it appears in the lungs as secondary to disease elsewhere in the system. Metastasis is probably effected by means of particles of living cellular material which are transferred through the blood-vessels or lymphatics.

Cancer of the lung often reverses the rule that carcinoma occurs most frequently in the female, Hasse, Kohler, and Cockle giving a majority of cases among males. It has been met with in childhood and in extreme old age, but is more common in the middle periods of life, from twenty to sixty years.

PREDISPOSING AND EXCITING CAUSES.—The predisposing and exciting causes of malignant pulmonary disease are involved in the obscurity that surrounds the development of all neoplasms.

PATHOLOGICAL ANATOMY.—Clinically speaking, cancer in the pulmonary tissues includes the scirrhous or encephaloid neoplasms. The colloid, enchondromatous, or fibromatous growths have been recorded as possible tumors, but possess only a pathological interest.

Malignant disease may commence in, or ultimately implicate, one or all of the pulmonary tissues; secondary neoplasms have been experimentally produced by lodgment in the lung of living cellular particles which grew centrally by virtue of inherent cell-proliferation, independently of changes produced in the surrounding tissues. Cancer of the lungs, whether primary or secondary, usually originates near the roots of the lungs, implicating the mucous and submucous membranes of the bronchi, sometimes commencing in its small mucous follicles. The bronchial passages and the lymph-channels become the viaducts along which the growth proceeds in its march of invasion, involving most frequently the posterior portion of the middle lobe. The apices of the lungs may be implicated, but not primarily, as in tuberculosis. The mediastinal lymphatics are originally involved in an unestimated number of cases, or enlargement of these glands is coexistent with the development of pulmonary cancer. The enlargement of the mediastinal glands is sometimes moderate, but an enormous mass may be formed. (Vide MEDIASTINAL TUMORS.)

Carcinoma is found in masses varying in size from a hempseed to an orange or larger, and since its distribution follows the lymph-channels in their circuitous route through the lung, we can account for the wide distribution of the nodular masses of secondary cancer. The isolated nodules present an ovoid outline, sometimes situated near the pleural surface, in contrast with the larger formations which affect the roots of the lungs.

The primary malignant formation presents a single large mass of infiltration, possibly associated with a few small nodules scattered throughout the lungs; the right lung is conceded to be the most frequently affected, but secondary cancer usually implicates both organs.

Cancer in the parenchyma of the lung may diminish or occlude the lumen of the bronchial tubes, or they may be filled with cancerous matter and their walls perforated. The development of cancer along the distribution of the bronchial passages shows us how readily chronic bronchitis may occur as a complication and form a confusing element in the diagnosis. The remaining pulmonary tissues may escape anatomical change, or from pressure atrophic or hypertrophic emphysema or collapse may ensue. These changes, together with the similarity to a fibroid phthisical process which many cases suggest, must be borne in mind in making a diagnosis. Pulmonary apoplexy, or even gangrene, is an incident in some of the clinical pictures of this disease, and embolism or thrombosis in other parts of the system may occur. The terminations of intra-thoracic cancer vary in accordance with the history of these growths elsewhere. Infiltration with blood or melanic deposition has been noticed; evacuation of the new growth through the bronchi may induce the development of cavities in the lungs, preceded or accompanied by suppuration, ulceration, or gangrene. In addition, hydro- or pyo-pneumothorax may occur by perforation or invasion of the pulmonary pleura.

Carcinoma of the pleura is usually secondary to its development in the lung, but it may be communicated from a similar process in the mammary gland by infection through the pectoral and intercostal muscles to the parietal pleura. Carcinomatous formations on the pleura are small and hard in scirrhous, but are larger in encephaloid, cancer. The minute spots of early formation are found scattered over the pleura like drops of wax. The thickened tissues, when they coalesce, undergo degeneration, and may form plaques of cartilaginous hardness. Large pleural growths may compress or nearly efface the lung, but are among the curiosities of medical literature.

Neuralgia may be occasioned when nodules impinge upon the intercostal nerves. Similar pressure is the cause of the pain in pulmonary cancer, except that induced by the pressure of mediastinal enlargement. Chronic pleural inflammation may be frequently developed by the new growth, and the diseased lung may become adherent to the inner surface of the sternum and ribs. The lung in other cases may be compressed or retracted, uncovering the heart and rendering the chest-walls smaller. The chest may be enlarged, especially if there is pleural effusion; usually the contour is unchanged.

Pleural effusions are frequent in the history of this disease: they may be passive, resulting from pressure on the azygos or hemiazygos veins, preventing the return of the blood from the pleural veins, or from mediastinal pressure. An inflammatory hydrothorax may be excited by the deposit of cancerous material in the pleura; and it is possible for these effusions to undergo purulent transformation or to become hemorrhagic. A hemorrhagic effusion when grouped with other symptoms may be considered an important evidence of malignant formation. The further history of pleural effusions in this association is usually an increase of such an amount as to necessitate removal by thoracentesis, but reabsorption is possible.

SYMPTOMATOLOGY.—The interest of the clinical observer nucleates itself around the symptomatology and diagnosis. The frequent negative results of physical examination indubitably prove that its teachings alone are insufficient for the purposes of diagnosis, so that any study of a case would be partial which did not unite the evidence yielded by physical signs with the general symptoms. The clinical evidences are more definite when the neoplasms are multiple and associated with some mediastinal process than when single or absolutely primary growths. The development of the disease is insidious. Gradually the facies and general surface of a patient indicate the true nature of the malady by the characteristic cachexia. Cough is an early symptom, unimportant save that it cannot be assigned to any definite cause. It may be dry and hard, attended only by expectoration of glairy mucus, or the sputa may be purulent. Usually the amount is in ratio with the degree of coexistent bronchitis. In the latter stages of the disease the sputa may contain blood, resembling prune-juice or black-currant jelly, due to erosion of some of the blood-vessels. In this stage of softening cells characteristic of the new growth, with portions of the pulmonary structure, may be found on microscopic examination of the sputa; the appearance of the expectoration sometimes suggests fibrinous bronchitis.

When there is elevation of temperature it may present a hectic type, with night-sweats, which are stated by Walsh to be sometimes confined to the affected side. The presence of an abnormal temperature-curve is indicative of associated inflammation of the bronchial mucous membrane, the development of a pleural process or of phthisis, especially the fibroid form. The pulse becomes accelerated in ratio to the degree of these inflammations and the failure of the sufferer's strength.

The new growth determines some mechanical symptoms cognate to all intra-thoracic tumors, especially those which involve the mediastinum. Lancinating pain would presumably be a constant symptom, but is, in fact, infrequent, unless the growth or growths enlarge so as to cause pressure on the nerve-trunks, in which event pain may become a distressing symptom. Characteristic pains complicate those cases in which the pleural tissues are involved in the morbid process. Dyspnoea is a pressure-symptom of considerable import if other conditions capable of producing it, especially uncomplicated emphysema, are rigidly excluded. When the new formation is infiltrated throughout the lungs, the growth may, as in miliary tubercle, impair the aërating power of the lungs by diminishing their elasticity and increasing their density. When, however, the process is local and restricted, the dyspnoea may be due to irritation of the terminal filaments of the vagus; this being a mixed nerve composed of accelerator and inhibitory filaments, the balance of innervating power may be readily destroyed and partial or incomplete respiratory effort follow. Dyspnoea may also result from pleural adhesions or effusions, or may be secondary to direct cardial or pericardial involvement in the cancerous process. Palpitation or increased pulse-rate may be referred to irritation of the vagi, or to some of the foregoing pathological processes.

Kindred to these symptoms are the changes in the voice, which sometimes undergoes frequent variations due to irritation or pressure on the trachea or on the branches of the pneumogastric nerve, especially when mediastinal disease is present. Aphonia, huskiness, a bass voice, or high treble, one or all, may be constant or alternating harbingers of the concealed mischief. The laryngoscope will inform one whether there is direct involvement of the larynx with morbid growth. Dysphagia is to be expected if the new formation involves the regions through which the oesophagus passes, and a sacculated pouch may be formed above the compressed spot. Changes of posture may increase or diminish the pressure, and thus the dysphagia or dyspnoea may at times be more pronounced than at others. Dysphagia may also be due to swelling of the oesophagus near the location of pressure. Reflex irritation of the sympathetic ganglia may induce pupillary contractions in one or both eyes: this symptom is chiefly present when the mediastinum is involved.

The physical signs contingent on pulmonary cancer include those ordinarily indicative of bronchitis with or without atrophic emphysema, simple pleural effusion, or chronic pleurisy with retraction. By inspection a study should be made of the contour of the thorax, the respiratory movement, and displacements of the intra-thoracic viscera. The thorax may appear enlarged, either from the new formation or from associated pleural effusions. It is often retracted, owing to the atrophic changes, and collapse brought about by the new formation or induced by pleural adhesions. The movements of the chest, unless there is a pleural complication, possess no distinctive character in this disease. Displacements of the heart or trachea may be expected on mechanical principles if there is mediastinal disease. General inspection may detect in the clubbed fingers evidences of venous obstruction, and sometimes an asphyxial hue of the upper portion of the body. Nearly always a general emaciation with anxious expression exists, and a tawny or lemon-hued skin indicative of the cancerous cachexia.

By palpation of the substernal or supra-clavicular spaces one may reach masses of painless, movable, glandular enlargement, but these may be easily overlooked unless a careful study be pursued. Circumscribed swellings of the thoracic walls may be detected, though not often, and the glands of the axillæ and neck may enlarge. Palpation may also reveal an inequality in volume between the radial pulses, but not so commonly as in purely mediastinal tumors or in aneurisms. Percussion and auscultation are negative or yield an area of dulness or flatness with restricted or absent respiratory murmur. When there is a single large growth the boundaries of these signs are local. If the tumors are diffused the respiratory murmur varies. In tiers of lung it is feeble or absent; elsewhere it is harsh, puerile, or bronchial. Chiefly remarkable is the fact that the character of the respiratory murmur cannot be harmonized with any other pulmonary states when the entire clinical evidence is taken. Vocal resonance corresponds with the respiratory murmur according to accepted laws. When there is pressure on the principal bronchus on one or both sides, one can detect either a snoring, increased bronchial respiration, or else, if the pressure decidedly narrows the calibre of the bronchus, the breathing becomes feeble or wheezing. Expiration may be prolonged and sonorous in character, with or without râles. The pressure is rarely equal on the two sides. The vocal resonance in these cases is ringing and brazen. Mensuration corroborates inspection. Pleural effusion from whatever cause is revealed by the ordinary signs. Enlargement of the bronchial glands, either primary or coexistent with the development of cancer in the lung, reveals itself by pressure-symptoms proportionate in their severity to the degree of bronchial enlargement. Pain, laryngeal irritation, differences in the radical pulses, tumor if the enlargement is anterior, one or all, may be present. The aorta itself may be compressed by the enlarged glands; and by the narrowing of its lumen thrill, and even systolic, murmur can appear, making a differential diagnosis from aortic aneurism very difficult. (Vide MEDIASTINAL TUMORS.) Embolism and thrombosis, with the ordinary symptoms, may complicate the course of pulmonary cancer and obscure the diagnosis.

The duration of cancer of the lung is fixed by Walsh at 13.2 months, mean average, maximum, at 27 months; minimum, at 3.5 months; but this is based on a confessedly small contingent of cases. The first symptoms, dry cough, pain in the chest, difficulty of breathing, may last for some years without alarming the patient. After the more dangerous phenomena appear the course is often more rapid. The history of cancer in the lung in the main corresponds with cases of similar types of cancer elsewhere. The grave symptoms appear earlier in cases of mediastinal cancer than in cancer of the lungs proper. Death may result from asphyxia; from bronchial obstruction; from pulmonary oedema occurring suddenly, as in chronic alcoholism; from embolism of the pulmonary artery; or from pleural effusion. Life may gradually ebb away through general asthenia with malnutrition; in some remarkable cases the same result is accompanied by hectic fever and the typhoid phenomena, with evidences of tissue-disintegration.

COMPLICATIONS.—The complications of pulmonary cancer have been already outlined. They are chiefly the bronchial, pleural, and mediastinal processes. Primary cancer of the lungs possesses a feeble tendency to metastasis.

DIAGNOSIS.—The most valuable assistance is derived from a close study of the personal and hereditary history. Whenever a new growth has been extirpated, the possibility of its reappearance in the lungs should always be remembered. The most disciplined comparative analysis of physical signs may be fruitless. The origin of a primary growth from the roots of the lungs may help to interpret the physical signs, and examination of the sputa should never be omitted. In secondary cancer the history of the case may include the removal or development of morbid growths from other parts of the body. Any pulmonary symptoms in these cases become more suspicious than they would in persons in whom no signs of cancerous diathesis have ever made their appearance. This rule must not be pressed too far, for forms of pleurisy, bronchitis, and pneumonia or phthisis may be the explanation of the symptoms.

In the differential diagnosis it is a matter of universal experience that some form of chronic pleurisy is the most frequent source of doubt to the clinician. It has been said by Wintrich that vocal fremitus in cancer is more often present than absent. If there is much pleural effusion, paracentesis will be helpful in two ways. When the fluid is turbid, highly albuminous, with a large proportion of coagulable fibrin, it is an evidence of its inflammatory origin; but if it is clear and limpid, and upon standing gives but a delicate veil of pseudo-fibrin, it indicates a passive or mechanical cause. If the fluid evacuated should contain any considerable amount of blood, such a peculiarity in association with the other symptoms already indicated is to be regarded as probable evidence of the existence of cancer of the pleura. If the external veins of the thorax are enlarged, they indicate a deep-seated cause of pressure. In malignant disease with retraction there may be less deepening and narrowing of the intercostal spaces on full respiratory movement than is associated with chronic pleurisy: there is usually greater volume and nearness of the respiratory murmur, although this is more noticeable on the left than on the right side, since the liver is present in the latter. The greater severity of the local symptoms and the increase in gravity of the disease must be contrasted with the features of a disease in the decline, as is the case in chronic pleurisy. Walsh considers that "the normal position of shoulder, spine, and scapulæ distinguishes cancer from the results of simple pleurisy." In addition, we have the shorter duration of cancer, which is never over two and a half years, often less. The lemon-hued cachexia is so frequently absent that the inference from general inspection of the features is marred. From fibroid forms of pulmonary disease we have the pressure-signs, giving evidences of mediastinal new formation; also the possible prune-juice expectoration of cancer. The retraction and displacements of the intra-thoracic organs, chiefly the heart, are greater in fibroid disease than in either pleurisy or cancer.

In addition, the history of phthisis includes a higher thermometrical record, frequent hæmoptysis, and abundant sputa. Physical diagnosis in cases of phthisis reveals a destructive process involving extensive areas of pulmonary tissue in a comparatively regular sequence. The cancerous process is more local or involves the tissues in an irregular order. Moreover, the asphyxial hue and the pressure-symptoms preponderate in malignant disease. To distinguish the cancerous process from simple forms of bronchitis we may observe the frequency with which the symptoms of bronchitis recur in cancer without exposure to an adequate cause; by the absence of marked tendency to hypertrophic emphysema; by the resistance to treatment; by the persistence of dyspnoea as a prominent symptom; and by the gradual development of patches of hypostatic congestion. To differentiate from aneurism we should consider the occupation of the patient, the absence of syphilis or other causes of arterial disease, the history, the location of the tumor, and the absence of the murmur. Hydatid cysts may simulate cancer, but this disease is rare in America. (Vide PULMONARY HYDATIDS.) In cancer of the liver, as that organ enlarges pulmonary symptoms may occur from irritation, and congestion or oedema be produced. We must be content to mention the possibility of error, and decide in each case after a crucial analysis of the abdominal or thoracic symptoms.

PROGNOSIS; TREATMENT.—The prognosis is fatal; the treatment purely palliative. It is quite justifiable to relieve pain by the hypodermic use of morphia, cough by chloral or the usual narcotics, and fetor of the breath may be palliated by inhalation of carbolic acid or other disinfectants. Dyspnoea may be alleviated by the use of strychnia as a respiratory stimulant—by inhalation of nitrate of amyl or small allowances of chloroform or digitalis. Paracentesis thoracis must often be resorted to in cases of pleural effusion, even although the relief it affords be temporary.

PULMONARY HYDATIDS.

BY EDWARD T. BRUEN, M.D.

DEFINITION.—A disease in the lungs consequent upon the entrance into the human system of the eggs of a small tape-worm, whose usual habitat is the upper half of the small intestine of the dog.

SYNONYMS.—Tænia echinococcus; Acephalocyst. Fr. Kystes hydatiques du poumon; Ger. Lungenechinococcus.

HISTORY.—Unmistakable references to this disease are found in the writings of Hippocrates, Aretæus, Galen, and other early writers. For a long time, however, the animal character of the hydatid cyst was not recognized, but confounded with slowly-developed local dropsies of various orders and with lymphatic dilatations. Their animal nature was suspected by Hartman in 1685, but their origin was not separated from the cysticercus. In 1766, Pallas clearly distinguished the two species, and this author was followed in a more positive way by Groeze in 1782. Laennec in 1804 carefully studied the hydatid cyst as found in the sheep, recognizing even the mode of reproduction, but he erroneously described the same parasite, when existing in man, as a distinct animal, which he termed acephalocyst. Since 1821, Bremsen, Davaine, Küchenmeister, and others have definitely settled the true mode of the entrance of the Tænia echinococcus into the human system, and the subsequent development of the hydatid cysts. The development of the parasite resembles that of the cysticercus. Like the latter, the larvæ infest the bowels of certain animals, and take their further development in a different animal or species, forming vesicles which are distributed in the parenchyma of the different organs, and in this way more or less seriously compromising the functional life of the part in which they occur.

ETIOLOGY. (See article on INTESTINAL WORMS, by Leidy.)—Hydatids have been found in the human subject in all countries, but especially in France, Germany, and in the north of Europe. They are rarely found in North America, and the fact that the majority of cases seen here have occurred in foreigners favors the probability of the hydatid disease having been imported. But there are two countries where it may be said to be endemic—Iceland and Australia. Finsen found 1 out of every 43 inhabitants affected with this disease in the district of Ofjord in Iceland. Hydatids are communicated to the human race through the system of the dog, and in Iceland the proportion of these animals to the population is probably more than 1 to 3, a recent census recording 20,000 dogs to 70,000 inhabitants. Hydatids usually enter the system through the digestive and respiratory organs. The Icelanders are excessively uncleanly and careless of the laws of ventilation. In the winter season both men and women are confined to the house in company with their dogs, and in consequence the air is impregnated, and oftentimes the drinking-water contaminated, through their dejecta, which contain thousands of the eggs of the echinococci. The largest number of cases occur in the agricultural districts, since the dogs are more required there than on the sea-coast.

In Australia large numbers of dogs are maintained to guard the sheep. The droppings of these animals, dried by the hot winds, are inhaled as dust. It is curious to note that in Australia, where the high winds prevail, the proportion of pulmonary hydatids is very large, while in Iceland, where the drinking-water is the principal medium of communication, the lungs are less often affected than other viscera. Finsen's records in the latter country show 255 cases; of these, 176 occurred in the liver, and only 7 in the lungs. In both Iceland and Australia women are more subject to echinococci than men. This is possibly accounted for by the facts that the women take care of the dogs and wash the vessels from which they eat, and are also less protected by hair about the mouth and nose than men.

The disease occurs most often between the ages of twenty and thirty years, but it has been found in children of four years of age. Before ten and after sixty the proportion of cases in both sexes is equal. The malady is not hereditary, but uniformity of environment accounts for the propagation in communities. Pulmonary hydatids occur as primary formations in the lungs, but may be secondary to similar growths elsewhere, especially in the liver. There is, however, scarcely a tissue in the body in which hydatids have not been found.

MORBID ANATOMY.—Hydatid cysts consist of sacs of various sizes, from that of a pea to an orange or even an adult head. They are usually globular in shape, and attached by a vascular membrane to the organ in which they are situated. The walls of the cysts are composed of a few laminæ of indeterminate membrane of varying thicknesses, commonly depending on the age of the cyst. In young cysts they occur in direct contact with the lung, but as they grow larger a thicker investment is formed, and large old cysts which have generally undergone spontaneous rupture often have a dense leathery sac. Walsh asserts that the parent cyst lies in direct contact with the lung-tissue, and, unlike that of the liver, is rarely surrounded with a thick shell or cyst-wall of pseudo-areolar tissue. The interior of the pouch is smooth and of the aspect of serous membrane without epithelial covering. The parent cyst contains daughter cysts which are single or multiple, and a liquid the proportion of which is variable. This liquid is nearly limpid, and non-coagulable by heat or acids; it deposits by evaporation crystals of chloride of sodium.

Commonly, only one hydatid tumor is found in the human lungs, although in animals multiplicity of cysts is the rule. They are usually located in the base of the lungs, and are thought to be more common on the right side, but they may occupy any portion of one or both lungs. They have been found in the pleura, the bronchi, the pericardium, and the thyroid gland. In the pleural cavity they may be attached to both the costal and the visceral pleura; in the latter case they may form an outgrowth from the lung into the pleural cavity. Authorities differ as to the condition of the neighboring lung-tissue, some stating that the cysts are rarely surrounded by healthy lung-substance, while others assert the contrary. Since the growth of the cysts is often very slow, the accommodating power of the lung is remarkable when no constitutional mischief exists. In some instances the rapid enlargement of a cyst has been accompanied by certain forms of pneumonia, secondary inflammatory lesions, congestion of the neighboring tissue, splenification, or even gangrene.

Hydatids situated either in the lung or pleura may rupture into the bronchial tubes, and thence be discharged by cough and expectoration, or they may open externally like a pleural empyema, or even rupture through the diaphragm into the intestines or peritoneum. None of the above accidents are necessarily fatal, not even the latter, unless the fluid be puriform. Empyema with pneumothorax usually follows rupture into the pleura. Finsen observes that a general urticaria may follow the rupture of a cyst into a serous cavity. In old cases, after rupture of cysts, pulmonary changes may almost always be found. The ruptured cyst may become a suppurating cavity, suggesting the possible development of phthisis. In some cases hydatid formations have been described with coexisting catarrhal or tubercular disease, or these processes may occur as a complication without rupture of the cyst.

SYMPTOMS.—The symptoms of hydatid cysts are obscure, and the physical signs difficult to analyze when the cysts are small. They are more suggestive when the cyst becomes large enough to contain a pint or more of fluid. The outline of the cyst is usually globular, and is imbedded in healthy or nearly healthy lung-tissue. According to Bird, the physical signs correspond with those familiar to us in pleural effusions: absolute dulness or flatness on percussion, with absence of respiratory murmur over a space of the chest-wall not smaller than the palm of the hand; vocal fremitus and resonance are also abolished. The expansion of the chest is more or less deficient upon the affected side, but seldom with any change on mensuration.

The area of the above physical signs usually presents a rounded outline, limited by a line of demarcation so exact that it can be mapped out with pen and ink, but is unaltered by position. Their location is generally in the lateral or infra-clavicular regions; beyond the boundary-line percussion is vesiculo-tympanitic resonant or normal, and the respiratory sounds begin at the very margin of the pen-and-ink line, and, though probably harsh and puerile in character, are indicative of healthy lung-tissue.

Pulmonary hydatids can seldom be examined by palpation, but all authors allude to a frémissement or peripheral fluctuation which may sometimes, but not invariably, be detected by palpation over the intercostal spaces. Davaine directs palpation as one would palpate an abdominal cyst. The sensation of fluctuation is as though the fluid were gelatinous; when the quantity of liquid is excessive this movement is not perceptible. It is most recognizable when there is but a single hydatid in the parent cyst (Jobert). The frémissement cannot be felt when the sac has undergone atheromatous degeneration, because there is then no liquid, and the cysts are withered, agglutinated to one another, and the tumor is inelastic and hard. By auscultating the tumor while practising percussion one may hear more or less positive vibrations resembling those produced by a bass string (Briançon).

The general symptoms of pulmonary hydatids are of mechanical origin: pain, dyspnoea, cough, with duskiness of the surface, all of which are more or less marked according to the size and location of the tumor and its rapidity of growth. A phthisical appearance is possible, with deterioration of the blood-crasis and progressive loss of flesh. Marked clubbing of the finger-ends and incurvation of the nails have been noticed, all of which symptoms have disappeared after the hydatid cyst has been tapped or expectorated. Cough nearly always accompanies this disease, as it does a large pleural effusion. The expectoration is a glairy mucus, sometimes stained with blood; when local bronchitis occurs as a complication, it may become muco-purulent. There is much diversity of opinion as to the frequency of hæmoptysis, many authors looking on it as a rare symptom. According to Bird, there is seldom or never profuse hæmoptysis, though several ounces have been expectorated at a time in an aggravated case where tapping had been long delayed. The cause of hæmoptysis is usually pressure of the growing cyst upon the pulmonary veins, leading to extravasations of blood.