CHAP. II.] EFFUSION AND PEPcSPIRATION. 79 



included the whole secret of my method of cure in 

 such attacks ; and, in this case, gentle sweating is 

 that remedy which is best calculated for restoring 

 the function. 



22. When the skin does not permit evaporation, 

 and send forth the secretion by perspiration, dis- 

 ease has begun, the hair looks staring near the 

 part affected, and not a stable-boy exists, who, 

 when he sees a horse with a rough coat, cannot tell 

 that " something or other is the matter with him." 

 This arises from want of moisture within ; the skin 

 itself not having the power of secreting or drawing 

 towards it, by effusion, the moisture which is neces- 

 sary to keep it supple, it shrivels up, and this im- 

 portant evacuation, which is second only to the 

 urinary, is then stopped, so that even the insensible 

 perspiration ceases. Some idea respecting the 

 amount of this insensible evacuation may be formed 

 by placing a horse, that has been exercised, be- 

 tween ourselves and a well white-washed wall upon 

 which the sun shines ; when the shadow of the 

 insensible perspiration may be seen upon the wall 

 ascending in tolerably thick volumes, something 

 very like steam from a boiling pot. Indeed, the 

 insensible perspiration is, when compared to sweat- 

 ing, the same as warm water compared to boiling 

 water. 



Yet, although we do not know the exact work- 

 ings by which this internal effusion (as it is called) 

 of the watery particles from one part of the animal 

 to another takes place, we do know, accurately 



e 4 



