In the case of the bronchial glands, a communication is occasionally established between their contents after they have softened and the channel of the bronchi, and may be thus evacuated, by expectoration. The chalky concretions find their way out occasionally in the same A remarkable instance of death being caused by the impaction of the cretaceous contents of a bronchial gland in the bronchi, is detailed by Dr. Tice, in the twenty-sixth volume of the Medico-Chirurgical Transactions.

manner.

CARCINOMA.

The lymphatic glands are very commonly the seat of malignant disease; it affects them either primarily or secondarily, but more frequently in the latter form. It is probably owing to the implication of the lymphatic system that we may, in part, at least, attribute the symptoms of cancerous cachexia in an advanced state, as influencing the process of nutrition and assimilation. No other part of the economy is so liable to secondary cancerous deposits as the lymphatic glands; the immediate cause of their becoming the seat of the heterologous growth being the introduction of cancer blastema from the affected organ, or an irritation set up by the proximity of the gland to the latter, which, in its turn, excites a fresh separation of cancer matter from the blood. The second explanation is probably that which obtains in most cases; for we find the parenchyma of the gland to be the prevailing seat of the disease, both in primary and secondary carcinoma of the lymphatic glands. It commonly appears in the shape of a general infiltration, and rarely in isolated nodules or islets. The encephaloid or medullary variety is the form which carcinoma generally presents in the glands. In a case of pancreatic sarcoma affecting the thoracic muscles of the right side, which fell under our own observation, there was a development of a similar morbid growth in the anterior mediastinum, evidently involving, if not proceeding from, the bronchial glands. The tissue was made up of fibres and fibroid cells and circular corpuscles, containing oil-particles. The lungs and other viscera presented no trace of a similar disorganization. In another instance, occurring at St. Mary's Hospital, in which the bronchial glands were converted into a mass closely resembling a malignant growth, though the microscope only exhibited granular corpuscles, resembling the forms seen in tubercle, the lungs were free from substantive disease, though the spleen was both disorganized and hypertrophied, and presented in its tissue deposits resembling those found in the bronchial growth.

MELANOSIS.

An affection to which the glandular system, and especially those parts in relation to the respiratory organs, is very prone, is melanosis; it is scarcely, however, to be looked upon as a morbid process in itself, but rather as an evidence of the depurating functions by which they assist in eliminating the superfluous carbon from the blood. We have shown

elsewhere that melanosis does not, in itself, constitute a malignant disease, and that it does not consist of a new formation, but that it is mainly a secretion of normal constituents of the blood, though frequently complicated with malignant affections. While it is unusual to find black matter in the lymphatic ganglia of the abdominal or inguinal regions, we constantly meet with it in the glands surrounding the bronchi.

ENTOZOA.

The only instance on record, of entozoa being found in the glands, is recorded by Rudolphi.' It was found by Treutler, in a person worn out by syphilis; it was an inch in length, tawny in color, semitransparent at one end, presenting two hooklets at its anterior extremity, and hence termed hamularia bronchialis.

1 Entozoorum Historia Naturalis, vol. ii. p. 82.

THE PATHOLOGICAL ANATOMY OF THE

ORGANS OF RESPIRATION.

CHAPTER XXVI.

GENERAL OBSERVATIONS.

WE learn from the registers of mortality that the most prevalent cause of death at various ages is to be found, in our climate at least, in morbid conditions of the organs of respiration; if it were possible to estimate the amount of disease introduced into the system through the lungs, though manifested in other organs, we should enhance the importance of an intimate acquaintance with their pathology still further. While the lungs serve the purpose of affording to the blood the means of effecting the changes of assimilation and metamorphosis, this very function renders them, by their extent of surface, and by their intimate relation to the capillary circulation throughout the body, more than any other organ the portal of disease. The impalpable poisons borne on the air enter the human economy chiefly by this entrance, and the system, debilitated by the various influences that wear out its strength, is attacked at this point by irritants of all kinds, introduced directly from without, palpable and impalpable. Thus, the lungs and their accessory parts are subject in various ways to suffer primarily or secondarily from causes that scarcely affect other organs; no age is exempt; no sex or rank offers any immunity; the common air is the common danger, and the sanitary measures necessary to anticipate or remove it, confer immeasurable benefits upon all, though the boon may be but scantily acknowledged.

We shall examine the pathological conditions of the different parts of the respiratory system in the order in which they naturally present themselves, as we proceed from the orifice downwards; commencing with the larynx and its appendix the epiglottis, we shall descend to the trachea, the bronchi and their ramifications, the pulmonary parenchyma, and the pleura. Though a definite relation exists between these different parts, which is more intimate in some than in others, they are each susceptible of isolated morbid states; and though the continuity of the mucous membrane lining the entire passages frequently induces a propagation of disease from one part to the other, this is by no means uni

versally the case, and the catarrh or croup affecting the larynx or trachea need not cause any pathological changes in the adjacent mucous membrane, or the other tissues of the affected part itself. The absolute importance of the morbid condition to the individual, does not necessarily bear a direct relation to its intensity, but depends a great deal upon the part affected; a point which the physiological laws regulating the different sections of the respiratory organs render sufficiently palpable; thus, a trifling amount of inflammatory swelling of the glottis or epiglottis threatens danger, while much more intense inflammation of the pulmonary parenchyma, or of the bronchi, may run its course without causing more than a temporary inconvenience. The features of the morbid condition may be identical, while their bearings upon the existence of the individual are widely dissimilar.

THE EPIGLOTTIS.

The epiglottis is, notwithstanding its exposure, not very liable to disease, a circumstance due in part to the dense fibro-cartilaginous tissue which forms its substratum. The mucous membrane which invests it, may be affected with acute or chronic inflammation, in which case the vessels enlarge and become tortuous and congested, and the light pink hue is converted into a streaky, or more or less uniform redness. The

Aente ulceration of the epiglottis and surrounding parts in a man, caused by taking a large dose of bichloride of mercury. Death followed after nine days; there were pneumonia, ulceration of the stomach, and infiammation of the entire intestinal tract.

acute form is commonly the result of mechanical injury or chemical irritation; while the chronic form accompanies old standing catarrhs of advanced age, arthritic or syphilitic cachexia, and other conditions resulting from general atony. The former is met with as a result of the action of irritant poisons, which may thus cause death without pass

ing the fauces; and as Dr. Marshall Hall' has pointed out, in consequence of children, as frequently happens among the poorer orders, drinking boiling water from the spout of the kettle or tea-pot. In these cases there is also rapid and extensive ædema, giving rise to a mechanical impediment to the admission of air into the lungs. In one of the instances detailed by Dr. Davis, suffocative dyspnoea supervened within three or four hours, and when at this period the attempt was made to apply leeches, the child, a little girl of three years of age, was much terrified, and screamed so violently, that they could not be applied. From this moment, however, respiration became easy, and a speedy recovery took place, owing most probably to a rupture of the bulle which had formed in consequence of the irritation. The remedy which in such a case relieves the immediate symptoms, and may thus be the means of saving life, is the operation of tracheotomy, though, as in the instance from which the delineation was taken, not always successful. Ulcerations of the epiglottis are not unfrequent, more especially as complications of phthisis; they are generally limited to the inferior surface of the valve and to its mucous covering; though they occasionally penetrate to the fibro-cartilage. They are not generally accompanied by much tumefaction or reddening of the surrounding tissue. Louis' states that in all the cases that fell under his notice, he only once observed ulcerations on the lingual surface; he found the breadth of the ulcers to vary from about one to two lines; though in some cases the laryngeal surface of the epiglottis was entirely deprived of its mucous membrane: in four cases the edge of the fibro-cartilage was destroyed, as well as the surface ulcerated, so as to give the part a festooned appearance; in a fifth case the epiglottis was totally destroyed. The proportion of phthisical cases in which the epiglottis is affected, appears, according to the same author, to be about one-quarter. These ulcers are not, however, the result of a fusion of tubercular deposit, which is not met with at this point, but of sympathetic irritation and inflammation; they, like other affections of the mucous membranes of the airpassages which have been mistaken for tubercular deposit, often originate in occlusion and sebaceous enlargement of the numerous solitary follicles scattered about the respiratory mucous membrane. These vary in size from an almost imperceptible point to a pin's head, and even to that of a bean; and closely resemble miliary granulations, surrounded by a halo of bloodvessels, as they appear for instance in the pia mater. The microscope, however, reveals their structure; showing the basement membrane of the follicle lined with epithelium, and containing oily matter. The cheesy particles coughed up by many people, are formed partly in the follicular structures of the tonsils; and probably also in the follicles of which we have just spoken. The epiglottis is liable to suffer from syphilitical ulceration, by an extension of the disease from the fauces: it very rarely passes beyond to the larynx and trachea. In smallpox and other eruptive fevers, the peculiar poison of the disease

Medico-Chirurgical Transactions, vol. xii. p. 1.

2 Ibid.

3 Researches on Phthisis, Sydenh. Soc. Ed. p. 42.

4 See a case detailed in Dr. Bright's Reports, ii. p. 644.