TORES OF THE SKIN. 
293 
PORES OF THE SKIN. 
The skin exhibits an infinity of pores over its entire 
surface, and probably the whole of these transmit hairs. 
There are also numerous others, smaller and less perceptible, 
which are called perspiratory pores, from their emitting an 
imperceptible vapour, denominated the insensible perspira¬ 
tion, the sensible perspiration being what is ordinarily called 
sweat. The situation of these pores is rendered manifest 
by the condensation and collection of this exhalation. But 
these pores can be rendered visible by maceration, or putre¬ 
faction in the dead animal. Besides these there is anothei 
set of pores, of larger dimensions, more discernible than 
others in some places, which are the mouths of follicles. 
These are of large size in the nose, for the secretion oi 
mucus; and the tubes of the ears have many of them for 
the passage of the waxy matter ; and all the portions of the 
skin which are liable to friction are numerously provided 
with them, which preserves it in a soft and pliable condition, 
and produces that greasiness of feel which is constantly kept 
up in the skin. 
This process of perspiration in the horse cannot be so 
controlled by the use of medicine as in the human being. 
The visible perspiration can only be increased in a limited 
degree in the horse, although we can in some measure lessen 
profuse perspirations which accompany the moult, disease 
or want of condition. 
The visible perspiration, as far as we know, cannot be 
produced by any kind of medicine. Antimony and sulphur, 
however, have considerable effect in opening the pores, and 
and in a certain degree exciting the vessels to action. 
There can be little doubt but the skin is furnished with 
absorbent vessels, which take in any substance in a fluid 
