2. The hæmoptysis is either a local disease, or it is the effect of general debility of the whole system. When it is local, or when it is the effect of causes which induce a _temporary_ or _acute_ debility only in the system, it is seldom followed by consumption. The accidental discharge of blood from the lungs, from injuries, and from an obstruction of the menses in women is of this kind. Many persons are affected by this species of hæmorrhage once or twice in their lives, without suffering any inconvenience from it afterwards. I have met with several cases in which it has occurred for many years every time the body was exposed to any of the causes which induce _sudden_ debility, and yet no consumption has followed it. The late king of Prussia informed Dr. Zimmerman that he had been frequently attacked by it during his seven years war, and yet he lived, notwithstanding, above twenty years afterwards without any pulmonary complaints. It is only in persons who labour under _chronic_ debility, that a hæmoptysis is necessarily followed by consumption. 3. I yield to the popular mode of expression when I speak of a consumption being produced by tubercles. But I maintain that they are the _effects_ of general debility communicated to the bronchial vessels which cause them to secrete a preternatural quantity of mucus. This mucus is sometimes poured into the trachea from whence it is discharged by hawking, more especially in the morning; for it is secreted more copiously during the languid hours of sleep than in the day time. But this mucus is frequently secreted into the substance of the lungs, where it produces those tumours we call tubercles. When this occurs, there is either no cough[21] or a very dry one. That tubercles are formed in this way, I infer from the dissections and experiments of Dr. Stark[22], who tells us, that he found them to consist of inorganic matter; that he was unable to discover any connection between them and the pulmonary vessels, by means of the microscope or injections; and that they first opened into the trachea through the bronchial vessels. It is remarkable that the colour and consistence of the matter of which they are composed, is nearly the same as the matter which is discharged through the trachea, in the moist cough which occurs from a relaxation of the bronchial vessels, and which has been called by Dr. Beddoes a bronchial gleet. [21] See Med. Com. Vol. II. [22] Clinical and Anatomical Observations, p. 26, 27. See also Morgagni, letter xxii. 21.