membranes are affected, as in rheumatism and pleurisy, the pain is 

 most acute and at times throbbing. Bone, in health, is almost non- 

 sensitive, but when under inflammation, from its unyielding nature, 

 the pain is excruciating. But we can have pain without inflammation ; 

 for instance, as in cramp or spasm. 



20. Redness is due to the accumulation of blood, coupled with a 

 distension of the vessels and a crowding of red corpuscles in the part, 

 and, finally, extravasation into the structures ; yet we can have redness 

 without Inflammation. 



21. Swelling arises from many causes, but in inflammation it is 

 occasioned by the congestion and exudation of the serous portions of the 

 blood, and extravasation of the blood itself, owing to the coats of the 

 distended vessels giving way. Still, we have swelling in various 

 parts of the body without inflammation ; as in dropsy, from debility, 

 swelling of the legs, from plugging of blood vessels or want of tone in 

 the tissues, or the swellings of Blains or " Howkes" (nettle-rash) in 

 cattle. 



22. Yet, when all these signs are found combined — i.e., Heat, Pain, 

 Redness, and Swelling — they are characteristic of inflammation, and 

 cause more or less constitutional disturbance in the body, with a 

 certain amount of fever, according to the situation and nature of the 

 attack. 



23. Inflammation is of various kinds, such as Acute (sharp and 

 quick). Sub-acute (not quite so active), and Chronic (of a slow 

 character). Again, the temperament and condition of different animals 

 influence the nature and degree of the inflammation. In strong, robust, 

 and well-fed animals the attack may be of a sthenic or high order, 

 marked by morbid over-action ; whilst in old, ill-fed, and weakly 

 constitutioned subjects, the nature of the attack is likely to be of an 

 asthenic or low character, marked by weakness ; thus showing how 

 important the study of all these variations is to the trained practitioner, 

 as they require entirely different modes of treatment. No one would 

 think of treating a strong, robust, well-fed animal in the same way 



