62' INFLAMMATION. 



flamed appear to become more vascular ;^^ tliough lie ima- 

 gines that appearance may be owing to the dilatation of the 

 capillary vessels. The same distinguished pathologist placed 

 the ear of a rabbit in a situation where it froze ; after which 

 he thawed it : this occasioned intense inflammation. In 

 this condition the animal was killed, and the two ears in- 

 jected, and afterwards dried. The uninjured ear dried clear 

 and transparent, beautifully displaying its arborescent vessels 

 from a single trunk ; but the inflamed ear dried thick and 

 perfectly opaque, at the same time exhibiting vessels double 

 in number, and of larger size; and, mstead of one, tivo 

 principal trunks. 



Explanation of the Heat. — An animal body derives 

 heat from its blood. That fluid in its passage through the 

 lungs undergoes certain changes, in consequence of which it 

 acquires the requisites for heat, to be evolved in a sensible 

 form in the course of its circulation : consequently, any part 

 through which a larger quantity of blood circulates than is 

 natural will be hotter than in health. At least, as was 

 before observed, this will be the case with parts whose tem- 

 perature is by nature below the standard of the body, or 

 lower than from 98° to 100° Far. Not but more heat is 

 evolved in every inflammation ; only, as was before stated, 

 it does not appear to accumulate : it seems to pass off" 

 almost as quickly as produced, operating on the sensations 

 of the patient without raising the actual temperature of his 

 body. Mr. Hunter conceived the body had the power of 

 generating cold as well as heat : and though his proofs of 

 this faculty are rather of a negative than of a positive kind, 

 we may say, it promotes evaporation in places of unusual 

 warmth to carry off any excess of heat. Our theories on 

 the subject of animal heat are not yet sufficiently matured 

 to e^iable us to speak more decidedly on the present point. 

 The nervous system is probably very influential ; and this 

 will necessarily add to the complexity of the subject under 

 consideration. 



The Sensation of the Pain is referable to the nervous 

 system. The nerves of the part inflamed appear to be in a 



