HvEM01tllllAGlE.S. 



corrupted, as to become unfit for the purpose of pus in the 

 healing of the ulcer. These seem to be possible causes of the 

 corruption of matter in abscesses, so as to make it the occasion 

 of a phthisis in persons otherwise sound ; but it is probable, 

 that a pneumonic abscess does especially produce phthisis when 

 it happens to persons previously disposed to that disease, and 

 therefore only as it concurs with some other causes of it. 



DCCCLXX. The third cause supposed to produce phthisis, 

 is a catarrh ; which, in many cases, seems, in length of time, 

 to have the expectoration of mucus proper to it, gradually 

 changed into an expectoration of pus ; and at the same time, 

 by the addition of a hectic fever, the disease, which was at first 

 a pure catarrh, is converted into a phthisis. This supposition, 

 however, is not easily to be admitted. The catarrh is properly 

 an affection of the mucous glands of the trachea and bronchia?, 

 analogous to the coryza, and less violent kinds of Cynanche 

 tonsillaris, which very seldom terminate in suppuration. And 

 although a catarrh should be disposed to such termination, yet 

 the ulcer produced might readily heal up, as it does in the case 

 of a Cynanche tonsillaris ; and therefore shouldjiot produce a 

 phthisis. 



DCCCLXXI. Further, the catarrh, as purely the effect 

 of cold, is generally a mild disease, as well as of short duration ; 

 and of the numerous instances of it, there are at most but very 

 few cases which can be said to have ended in phthisis. In all 

 those cases in which this seems to have happened, it is to me 

 probable, that the persons affected were peculiarly predisposed 

 to phthisis. And the beginning of phthisis so often resembles 

 a catarrh, that the former may have been mistaken for the latter. 

 Besides, to increase the fallacy, it often happens, that the ap- 

 plication of cold, which is the most frequent cause of catarrh, 

 is also frequently the exciting cause of the cough, which proves 

 .the beginning of phthisis. 



DCCCLXXII. It is to me therefore probable, that a catarrh 

 is very seldom the foundation of phthisis ; but I would not 

 positively assert that it never is so ; for it is possible, that the 

 cases of a more violent catarrh may have joined with them n 

 pneumonic affection, which may end in a suppuration ; or it 

 may happen, that a long continued catarrh, by the violent 



