I shall begin by remarking, I. That the pulmonary consumption is induced by predisposing debility. This I infer, 1st, From the remote and exciting causes which produce it. The remote causes are pneumony, catarrh, hæmoptysis, rheumatism, gout, asthma, scrophula, chronic diseases of the stomach, liver, and kidneys, nervous and intermitting fevers, measles, repelled humours from the surface of the body, the venereal disease, obstructed menses, sudden growth about the age of puberty, grief, and all other debilitating passions of the mind; hypochondriasis, improper lactation, excessive evacuation of all kinds, more especially by stool[18], cold and damp air, a cough, external violence acting upon the body[19]; and finally, every thing that tends, directly or indirectly, to diminish the strength of the system. [18] Sir George Baker relates, in the second volume of the Medical Transactions, that Dr. Blanchard had informed him, that he had seen the consumption brought on ten persons out of ninety, by excessive purging used to prepare the body for the small-pox. I have seen a case of consumption in a youth of 17, from the spitting produced by the intemperate use of segars. [19] Dr. Lind says, that out of 360 patients whom he attended between July 1st, 1758, and July 1st, 1760, in consumptions, the disease was brought on _one fourth_ of them by falls, bruises, and strains, received a year or two before the disease made its appearance. The most frequent exciting cause of consumption is the alternate application of heat and cold to the whole external surface of the body; but all the remote causes which have been enumerated, operate as exciting causes of consumption, when they act on previous debility. Original injuries of the lungs seldom excite this disease, except they first induce a debility of the whole system, by a troublesome and obstinate cough. 2. From the debilitating occupations and habits of persons who are most liable to this disease. These are studious men, and mechanics who lead sedentary lives in confined places; also women, and all persons of irritable habits, whether of body or mind. 3. From the period in which persons are most liable to be affected by this disease. This is generally between the 18th and 36th year of life, a period in which the system is liable, in a peculiar manner, to most diseases which induce it, and in which there is a greater expenditure of strength, than in any other stage of life, by the excessive exercises of the body and mind, in the pursuits of business or pleasure. I have conformed to authors, in fixing the period of consumptions between the 18th and 36th year of life; but it is well known that it sometimes appears in children, and frequently in persons beyond the 40th, or even 60th year of life. II. The pulmonary consumption is a primary disease of the _whole_ system. This I infer,