SECT. X. PHYSIOLOGY. 95 
the arterial system may proceed from various 
passions: Leo X. died of a fever caused by joy at 
the capture of Milan. 
cexvil. The expansion of the arterial system 
is synchronous with the contraction of the heart. 
ccx1x. No arguments are required to prove 
that the blood causes contraction in the arterial 
system; the increased impetus of the blood in an 
artery going to a local inflammation, and foetuses 
without hearts, are positive evidences of con- 
tractibility, which no sophistry can perplex, no 
experiments annul. 
ccxx. Acute inflammation.—When the arterial 
expansibility of an organ is increased to such a 
degree, that there are present, pain, redness, swell- 
ing, and preternatural heat; it is said to be in a 
state of inflammation. This morbid condition 
may be accomplished by causes which either aug- 
ment or diminish the vital force of the part. 
ccxxi. When the vital force is locally much 
augmented, as in a scald, the calibers of the ex- 
treme arteries are enlarged, and elicit a greater 
quantity of blood from their trunks, to the part 
affected, which inflames forthwith. The capilla- 
ries are more expansible than the extreme arteries, 
and participate largely in the morbid expansion of 
inflammation; and some have even supposed it 
situated exclusively in them. 
