Dr. Rush maintains the same doctrine, and relates that the late Dr. Beardsley of Connecticut, informed him that he had known several black slaves affected by a Consumption, which had previously swept away several of the white members of the family to which they belonged. In these slaves no suspicion was entertained of the most distant relationship to the persons from whom they had contracted the disease: nor had grief nor fatigue, been supposed to have had the least share in debilitating their bodies. The force of so much authority with the evidence adduced, constrains us to admit the communicability of Consumption by contagion. But if this agent has any effect, its action must be extremely limited, and extend no farther than to those previously predisposed to the disease. For daily examples without number occur of the constant attendants upon those labouring under Phthisis remaining perfectly free from that malady.
Violence done to the lungs by blows or other injuries of the chest, has in some instances, excited Consumption.[6]
Foreign bodies conveyed accidentally into the lungs has produced the same effect. Morton relates a curious case where three nails had passed into a person’s trachea and destroyed him, by inducing Consumption.
Bayle also enumerates a form of Phthisis, which he calls cancerous, arising in patients in whom the cancerous disposition has become constitutional. It is, however, extremely rare; only three cases having occurred to him among the 900 whom he had examined.
Hæmoptysis and tubercles are mentioned by most authors as exciting causes of Consumption, and remain to be examined. So frequently did Dr. Cullen consider Hæmoptysis the cause of Phthisis, that he placed the latter disease in his Nosology, merely as a consequence of the former. The impropriety of this arrangement has been already touched upon.
On this subject, I would suggest the following facts. Hæmoptysis occurring in persons not predisposed to Consumption, except the quantity of blood lost be so great as to produce it by mere debility, very frequently may be easily cured without danger of any consequent disease. Indeed not only in such cases consumption is not induced by it, but that disease has actually been prevented, by the occurrence of hæmorrhage from the lungs, relieving that inflammation, which the inert physician, by withholding the lancet, would have suffered to destroy his patient. Dr. Rush relates two cases of inflammatory Consumption attended by a hæmorrhage of a quart of blood from the lungs, in which the patient recovered; and ascribes their recovery entirely to the loss of blood. Wounds and other injuries of the lungs frequently heal, when no predisposition to Phthisis exists, as easily as in other parts of the body. Of this fact also Dr. Rush affords an example. A British officer informed him, a few days after the battle of Brandywine, in September 1777, that the surgeon general of the royal army had assured him, that out of twenty four soldiers admitted into the hospitals, during the campaign of 1776, with wounds of their lungs, twenty-three recovered. These facts prove sufficiently that the constant motion of the lungs does not prevent the healing process taking place in them as easily as in other parts of the body.
In most instances, the spitting of blood which is supposed to have produced the Consumption, has occurred a considerable period before the Phthisical symptoms appeared. During this interval perhaps the patient was perfectly well. Can it be supposed, that the inflammation necessary to form an ulcer, and the process of ulceration itself, could so long be going on unperceived, without producing any irritation of the lungs? Is it not more probable, that the Hæmoptysis was recovered from, and that the same cause which produced it, at length produced the Consumption?
Hæmoptysis, then, I would consider, as very seldom, perhaps, never, being the cause of Consumption; but in all those cases in which it is assigned as the cause, merely a symptom of the incipient stage of the disease. The symptoms accompanying hæmorrhage from the lungs, are no other than those of incipient Phthisis. They are thus accurately described by Dr. Reid. “When subsequent to a sense of weight and oppression in the breast, which scarcely amounts to a feeling of pain, together with cough, difficult respiration, and general lassitude, a quantity of blood is suddenly, and in a convulsive manner, discharged from the mouth, there can remain small doubt respecting the part from which it proceeds. If the discharged blood be of a florid colour, and together with the above symptoms, a saltish taste be perceived in the mouth, and the patient become sensible of a degree of irritation in the upper part of the trachea, the nature of the affection is rendered altogether unequivocal.” Every symptom here enumerated, occurs in the early periods of Consumption.
Nor have we any better reason for believing tubercles to be an exciting cause of Phthisis. These appearances are indeed very frequently found in dissections of the lungs of those who have died of Consumption. Of the nine hundred patients examined by Bayle, 624 had tuberculated lungs. Tubercles were formerly considered as indurated glands, and generally attributed to a scrophulous constitution; but we are assured by Baillie, in his morbid Anatomy, “that there is no glandular structure in the cellular connecting membrane of the lungs; and on the inside of the branches of the trachea, where there are follicles, tubercles have never been seen.” These tubercles are roundish bodies, of a firm consistence, and frequently a cartilaginous structure, but often containing decidedly purulent matter. By the union of several of them, vomicæ are formed, which are only larger tubercles. May not the formation of these bodies be sufficiently accounted for by the preceding inflammation, and they be considered therefore a consequence, rather than a cause of Consumption? Dr. Rush insists that tubercles are the effects, and not the cause of pulmonary Consumption; and remarks as a farther evidence of this opinion, that similar tumours are suddenly formed on the intestines by dysentery, and on the omentum by a yellow fever. He refers to cases of the former in the dissections of Sir John Pringle, and one of the latter mentioned by Dr. Mackittrick, in his inaugural dissertation on the yellow fever, published in Edinburgh, in the year 1776. Dr. Hosack, in his Lectures on the Theory and Practice of Physic, advocates the same doctrine, and enforces it, by remarking, that similar tubercles are formed in the parenchyma of the brain, the liver, and the kidneys, in which no small glands have yet been detected, and where, as in the lungs, there is nothing but cellular membrane and vessels. It is his opinion, that it is an union of a number of these cells in a state of congestion that constitutes tubercles or vomicæ—that in some instances they heal, the matter is absorbed, and they remain in a scirrhous state, the patient becoming perfectly restored to health; and hence the remark of Dr. Simmons, that tubercles may exist without Phthisis.
These are all the principal predisposing and exciting causes of Phthisis Pulmonalis. Some few others are mentioned by authors, but they are of either very doubtful agency, or too rare to deserve notice.