THEORY OF INFLAMMATION. 61 



awa}^ — by the experimental fact, that more blood will flow 

 within a given interval from those veins than from the corre- 

 spondent vessels on the healthy side of the body, — from the 

 circumstances of inflamed parts, when cut into, exhibiting 

 blood of the arterial character, and yielding it more rapidly 

 than corresponding structures when in health. 



Condition of the Capillaries. — This brings us to the 

 pith of the question. It appears, that the blood, which is 

 sent to the inflamed part, so far from being congested or 

 anywise stagnant, is actually flowing with increased velocity, 

 as well as fulness of current, through the capillaries : this is 

 made manifest by the plethora of the vessels that conduct 

 the blood away from the inflammation. Were it detained 

 in the capillaries, or retarded in its course through them, it 

 would undergo the changes consequent on its protracted 

 absence from the heart, and become dark in its hue ; and it 

 would issue but tardily from the venous trunks : whereas, 

 we know that the contrary of these suppositions is the case. 

 In fine, it would appear, from all facts we are able to collect, 

 that the blood is actually circulating through the capillary 

 system of a part under inflammation both in greater propor- 

 tion and with more rapidity than through the same vessels 

 in a state of health : the only explanation of which preter- 

 natural performance I can offer is, that the vascular powers 

 are roused and rendered capable of it by the sympathy of 

 the nervous system. Let us see how these explanations 

 tally with the symptoms. 



Explanation of the Redness. — This symptom is ovring 

 to the blood, in inflammation filling all its vessels to reple- 

 tion with red globules, the tubes in health being too small to 

 admit any but the finer and colourless portion of that fluid. 

 The shade of the redness is owing to the quality of the blood, 

 and also to the vascularity of the aff"ected part : the ^orid 

 scarlet complexion of the part being attributable to the arte- 

 rial character of the current of blood ; while tendons or 

 ligaments assume less redness under inflammation than skin 

 and muscle, because they are naturally less vascular. I say 

 "naturally^' so; for, as Mr. Hunter tells us, ''parts in- 



