4 PRACTICE OF PHYSIC. 



cause in our system ( Physiology ', p. 55.); and as it accom- 

 panies tension in this case, it is readily accounted for by the in- 

 creased impetus. 



" I believe there does not now remain, with any physicians, 

 the least doubt, that the whole of these symptoms do infer and 

 prove the existence of increased impetus of the blood, as the 

 principal circumstance in inflammation. 11 



CCXL. The cause of this increased action in the vessels of 

 a particular part, is, therefore, what we are to inquire after, and 

 to consider as the proximate cause of inflammation. 



In many cases, we can manifestly perceive that inflammation 

 arises from the application of stimulant substances to the part. 

 When the application of such stimulants, therefore, is evident, 

 we seek for no other cause of inflammation ; but as, in many 

 cases, such application is neither evident, nor, with any proba- 

 bility, to be supposed, we must, in such cases, seek for some 

 other cause of the increased impetus of the blood in the vessels 

 of the part. 



CCXLI. Many physicians have supposed, that an obstruc- 

 tion of the extreme vessels, any how produced, may prove a 

 cause of inflammation ; and, particularly, that this may arise 

 from an obstruction formed by a matter stopping up these ves- 

 sels. But many difficulties attend this doctrine. 



1. The opinion seems chiefly to have arisen from the appear- 

 ance of the blood described in CCXXXVIL, when the separ- 

 ated gluten was considered as a preternatural and morbid 

 matter: but we now know very certainly, that this gluten is 

 constantly a constituent part of the human blood ; and that it 

 is only a peculiar separation of the parts of the blood, that hap- 

 pens in consequence of inflammation and some other circum- 

 stances, which gives occasion to the appearance that was falsely 

 considered as a mark of the morbid lentor in the blood. 



2. There are no experiments directly in proof of a preternat- 

 ural lentor prevailing in the mass of blood ; nor is there any 

 evidence of certain parts of the blood occasionally acquiring a 

 greater density and force of cohesion than ordinary ; neither is 

 there any proof of the denser, or more coherent parts, being 

 present in the mass of blood in such greater proportion than 

 usual, as to occasion a dangerous spissitude. The experiments 



