166 



THE MODERN SYSTEM 



reooived opinion now is, that the production 

 or animal heat depends upon the difference in 

 the capacity of arterial and venous blood, for 

 (.ombinino- with caloric, and that in the minute 

 arteries, the blood is combined with certain 

 substances ; in consequence of which, its ca- 

 pacity is diminished, and heat is given out. 

 But when the venous blood has been freed from 

 such substances in the lungs, its capacity is 

 increased, and the heat which is given out by 

 the decomposition of the air which we inspire, 

 is absorbed. Now, if these things be ad- 

 mitted as facts, the augmented heat of in- 

 flammation may be conceived to arise from 

 the increased velocity of the circulation in the 

 part affected. More blood is transmitted into 

 the minute arteries, the capacity of a greater 

 quantity of this fluid for heat is of course there 

 necessarily increased, and more caloric is 

 e.\tracted. 



Pain. —This is observed to be greatest 

 during the diastole of the arteries. The 

 affection is probably owing to the unnatural 

 state of the nerves, and not to mere distention, 

 as many have asserted. Were the latter 

 cause a real one, the pain would be propor- 

 tioned to it. 



APPEARANCES OF THE BLOOD IN INFLAMMATION. 



Tlie blood, when taken out of the living 

 vessels, spontaneously separates into two dis- 

 tinct parts ; the serum, and the crassameti- 

 tnm. The last is a compound substance, 

 consisting chiefly of coagulating lymph and 

 red globules, the most heavy ingredients in 

 blood. Blood taken away from an animal 

 aflected with inflammation, is longer in coagu- 

 lating, and coagulates more firmly than in any 

 o<her instances. Hence, the red globules not 

 being so soon entangled in the lymph, des- 



cend by their gravity, more deeply from it« 

 surface, which being more or less divested 

 of the red colouring matter, is from its appear- 

 ance termed the buffy coat, or inflammatory 

 crust. The firmer and more compact coagu- 

 lation of the lymph compresses out an unusual 

 quantity of serum from it, and the surface of 

 the sizy blood is often formed into a hollow, 

 the edges being drawn inward. These 

 changes in the blood are, in some cases, a 

 more infallible sign of the existence of in- 

 flammation, than the state of the pulse itself. 

 At the same time, it is probably only a cri- 

 terion of some unusual operation going on in 

 the system. In peritoneal inflammation, the 

 Horse sometimes seems to be in the most 

 feeble state, and the pulse, abstractedly con- 

 sidered, would rather induce the practitioner 

 to employ tonics and stimulants, than evacua- 

 tions ; but should the contuiuance or exaspe- 

 rations of the disorder, or any other reason, 

 lead you to use the lancet, then the bujfy coat 

 and the concave surface of the blood clear 

 away all doubt concerning the existence of 

 inflammation. 



TERMINATION OF INFLAMMATION. 



Inflammation is said to have three different 

 terminations ; or, in more correct language 

 we may say, that after this process has con- 

 tinued a certain time, it either subsides en- 

 tirely, induces a disposition in the vessels 

 to form pus, or completely destroys the 

 vitality of the part. 



When the inflammation is to ena in the 

 first-named manner, which is the most fa- 

 vourable, the pain becomes less, the swelling 

 subsides, and every other symptom gradually 

 abates, till at last, the part is wholly restored 

 to its natural size. There is no formation ol 



