PRACTICE OF PHYSIC. 



toratione, in order to distinguish the tabes from the phthisis 

 pulmonalis. Further, the presence of fever is here the distin- 

 guishing symptom, and that is universally of the hectic kind : 

 now if we were right before in maintaining that there is no 

 idiopathic hectic, then there can be no idiopathic tabes : and of 

 that I am quite convinced, and it appears upon merely inspect- 

 ing the enumeration of Sauvages"* species."" 



MDCII. Upon this occasion, therefore, I hope it may be 

 useful to investigate the several causes of emaciation in all the 

 different cases of disease in which it appears. And this I at- 

 tempt, as the surest means of determining how far it is a primary 

 or a symptomatic affection only ; and even in the latter view, 

 the investigation may be attended with some advantage. 



MDCII I. The causes of emaciation may, I apprehend, be 

 referred to two general heads ; that is, either to a general defi- 

 ciency of fluid in the vessels of the body, or to the particular 

 deficiency of the oil in the cellular texture of it. These causes 

 are frequently combined together ; but it will be proper, in the 

 first place, to consider them separately. 



MDCIV. As a great part of the body of animals is made up 

 of vessels filled with fluids, the bulk of the whole must depend 

 very much on the size of these vessels, and the quantity of fluids 

 present in them : and it will, therefore, be sufficiently obvious, 

 that a deficiency of the fluids in these vessels, must, according 

 to its degree, occasion a proportionate diminution of the bulk of 

 the whole body. This, however, will appear still more clearly 

 from considering, that in the living and sound body, the vessels 

 every where seem to be preternaturally distended by the quan- 

 tity of fluids present in them ; but being at the same time elastic, 

 and constantly endeavouring to contract themselves, they must 

 on the withdrawing of the distending force, or, in other words, 

 upon a diminution of the quantity of fluids, be in proportion 

 contracted and diminished in their size : And it may be fur- 

 ther observed, that as each part of the vascular system commu- 

 nicates with every other part of it ; so every degree of diminu- 

 tion of the quantity of fluid, in any one part, must in propor- 

 tion diminish the bulk of the vascular system, and consequently 

 of the whole body. 



