2 PRACTICE OF PHYSIC. 



CCXXXVII. We judge of the presence of inflammation 

 also from the state of the blood drawn out of the veins. When 

 the blood, after cooling and concreting, shows a portion of the 

 gluten separated from the rest of the mass, and lying on the 

 surface of the crassamentum, as such separation happens in 

 all cases of more evident phlegmasia, so in ambiguous cases, 

 we, from this appearance, joined with other symptoms, infer the 

 presence of inflammation. At the same time, it must be ob- 

 served, that as several circumstances in blood-letting may pre- 

 vent this separation of gluten from taking place in blood other- 

 wise disposed to it, so, from the absence of such appearance, 

 we cannot always conclude against the presence of inflamma- 

 tion. 



CCXXXVIII. I cannot easily give any other general his- 

 tory of the phenomena of inflammation than what is contained 

 in the three preceding paragraphs ; and the variations which 

 may take place in its circumstances, will occur to be more pro- 

 perly taken notice of under the several heads of the particular 

 genera and species to be hereafter mentioned. I proceed, there- 

 fore, to inquire into the proximate cause of inflammation in 

 general. 



SECT. II. OF THE PEOXIMATE CAUSE OF INFLAMMATION. 



CCXXXIX. The phenomena of inflammation (CCXXXV.) 

 all concur in showing, that there is an increased impetus of the 

 blood in the vessels of the part affected ; and as, at the same 

 time, the action of the heart is not always evidently increased, 

 there is reason to presume, that the increased impetus of the 

 blood in the particular part, is owing especially to the increased 

 action of the vessels of that part itself. 



" An increased impetus in the vessels of the part will most 

 simply and obviously account for the circumstances of inflam- 

 mation, viz. the increased redness, the increased heat, the ten- 

 sion, and the pain. 



" The increased redness has been variously explained. We 

 set out with this, that the redness of a part depends on the 

 colour of the globules of the blood, which are red ; the increas- 

 ed redness of a particular part may therefore be explained by 



