THEORY or INFLAMMATION. 63 



state of excitement, and that which under ordinary circum- 

 stances would call forth common sensation, now produces 

 pain. One cause appears evident in the tumefied condition 

 of the part : the general bloated and tense state of the 

 inflamed tissues must oppress the nervous filaments, at the 

 same time stretching many of them considerably beyond 

 their natural tone. In parts of an unyielding nature, as 

 tendon or ligament, the pain is violent, at the same time 

 peculiar in its kind, owing to the severity of the compression 

 which the nerves must experience. Anything that tends 

 to relieve distension, at the same time relieves some of the 

 pain felt : during a violent inflammation in my own hand, I 

 experienced considerable mitigation of the pain whenever I 

 held it in an elevated position, with the arm as much as 

 possible extended ; the return of blood through the veins 

 being thereby greatly facilitated. On this principle it is 

 that pain is augmented at every throb of the inflamed part. 

 Gradations in pain are very variable, and will admit of ex- 

 planation because of the distribution of the nerves the 

 inflamed part may contain ; because of the yielding or un- 

 yielding texture of the part ; because of the violence of the 

 inflammation ; and, also, because of the nature of the exciting 

 cause. After all, however, we shall find ourselves forced to 

 confess, that the morbid sensibilit}^ of the nerves will not 

 admit of complete elucidation until we shall have become 

 better acquainted with their operation in health. 



Explanation of the Swelling. — The tumefaction of 

 an inflamed part is ascribable to the immoderate distension 

 of its vessels with blood, and to the efi*usion in the form of 

 serous fluid and coagulable lymph into the cellular tissue 

 and surrounding textures. In the early stage, the swelling 

 seems attributable to distension : efi'usion, however, speedily 

 supervenes, and in the latter stages constitutes the major 

 part of the enlargement, imparting to it a degree of firmness, 

 and often remaining after the inflammatory action has sub- 

 sided. The solid feel the tumour has about its more promi- 

 nent part, is owing to the eff'usion of a mass of gelatinous 

 matter, which turns out to be the same as coagulable lymph ; 



