50 PRACTICE OF PHYSIC. 



case of pneumonic inflammation, particularly entitled to the ap- 

 pellation of Peripneumony ; and that is, the case of an inflam- 

 mation beginning in the parenchyma or cellular texture of the 

 lungs, and having its seat chiefly there. But it seems to me 

 very doubtful if any acute inflammation of the lungs, or any 

 disease which has been called Peripneumony, be of that kind. 

 It seems probable that every acute inflammation begins in mem- 

 branous parts ; and in every dissection of persons dead of peri- 

 pneumony, the external membrane of the lungs, or some part 

 of the pleura, has appeared to have been considerably affected. 



CCCXLIII. An inflammation of the pleura covering the 

 upper surface of the diaphragm, has been distinguished by the 

 appellation of Paraphrenitis, as supposed to be attended with 

 the peculiar symptoms of delirium, risus sardonicus, and other 

 convulsive motions : but it is certain that an inflammation of that 

 portion of the pleura, and affecting also even the muscular sub- 

 stance of the diaphragm, has often taken place without any of 

 these symptoms ; and I have not met with either dissections, 

 or any accounts of dissections, which support the opinion that 

 an inflammation of the pleura covering the diaphragm is at- 

 tended with delirium more commonly than any other pneumonic 

 inflammation. 



CCCXLIV. With respect to the seat of pneumonic inflam- 

 mation, I must observe further, that although it may arise and 

 subsist chiefly in one part of the pleura only, it is, however, 

 frequently communicated to other parts of the same, and com- 

 monly communicates a morbid affection through its whole ex- 

 tent. 



CCCXLV. The remote cause of pneumonic inflammation is, 

 commonly, cold applied to the body, obstructing perspiration, 

 and determining to the lungs; while, at the same time, the 

 lungs themselves are exposed to the action of cold. These cir- 

 cumstances operate especially when an inflammatory diathesis 

 prevails in the system ; and, consequently, upon persons of the 

 greatest vigour, in cold climates, in the winter season, and 

 particularly in the spring, when vicissitudes of heat and cold 

 are frequent. The disease, however, may arise in any season 

 when such vicissitudes occur. 



Other remote causes also may have a share in this matter ; 



