OF ABSCESS. 455 



CHAPTER XII. 



OF ABSCESS. 



By abscess, in its most extensive sense, we include every 

 collection of fluid which interposes between parts in a kind 

 of sac : but in its limited sense, as we now propose to em- 

 ploy it, the word represents a collection of pus formed by 

 a quick process of suppuration, and contained within a 

 closed sac. When an abscess forms, the following process 

 takes place : — an injury, generally a bruise, is received : 

 part of the vital body is crushed or dies, and nature is 

 desirous to repair the loss, and to cast off the dead sub- 

 stance. The minute vessels of the part are stimulated to 

 effuse coagulable lymph within the cellular tissue ; the con- 

 sequence of which is distention or swelling, that here, as 

 elsewhere, produces tenderness and heat, and, when the hair 

 allows us to detect it, a reddened blush. The effusion 

 around the immediate part which is dead thickens, grows 

 vascular, and ultimately forms a closed sac. Arrived at this 

 state, the tumour may take on various changes by peculiar 

 processes within it : the suppurative one is supposed to 

 ensue all over the internal sides of the sac, where, by 

 a change in the action of the inflamed vessels, pus begins 

 to be secreted. It then presses against the adjacent mus- 

 cles, causing these structures to be absorbed : and it is for- 

 tunate that, by an apparent conservative law of animal 

 life, such absorption is most active towards the surface of 

 the body, thus aiding the evacuation of its contents, which 

 can be effected without prejudice to the constitution. There 

 are many difficulties to combat in veterinary practice which 

 almost vanish in human pathology : thus, in the formation 

 of human abscess, universal rigors mark almost the com- 

 mencement of the suppurative process. Neither is fluc- 

 tuation or direct prominence in the suppurating abscess so 

 clear in our subjects, from the thickness and tenacity of 

 the integuments ; though some little pointing, and softening, 

 as well as denudation of hair, may be observed : it therefore 

 becomes us to make our examinations the more closely, 



