194 A Manual of Veterinary Physiology. 



high and consists of soda and potash, especially the latter. 

 It will be observed that the mineral matter exceeds the 

 organic matter, and in horses which have sweated ireely 

 the matted hair (which is due to the albumin) is often seen 

 covered with saline matter, looking like tine sand. In the 

 paper referred to I have shown that there appears to be 

 some complemental action between the skin and the 

 kidneys in the elimination of soda and potash ; during rest 

 the kidneys eliminate these salts, whilst during work they 

 are assisted by the skin. 



It is difficult to see why horses should excrete albumin 

 by the skin. 



The secretion of sweat in the horse is governed by some 

 different nervous apparatus to that which exists in man 

 and other animals. I am not prepared to state what this 

 difference is ; it may only be a slight one, but it manifests 

 itself in the action of pilocarpine, which has absolutely no 

 effect on the sweat glands of the horse, though it produces 

 the most profuse salivary flow. 



The peculiar breaking out into sweats which occurs in 

 horses after work has no parallel in man ; nothing is more 

 common after a horse has been perfectly dried than to find 

 him break out two or three times into a sweat, which leaves 

 him as wet as he was originally.* 



We have no drug which can excite the sudoriferous secre- 

 tion in the horse ; this is an explanation of the common use 

 of nitre in veterinary practice : we make the kidneys do 

 what the skin is unable to. All this points to some 

 difference in the nervous arrangement, but until these 

 differences are ascertained we may provisionally adopt, as 

 the probable changes in the glands during sweating, the 

 results obtained on the sweat glands of carnivora. 



Sweating is produced by the action of the nerves supply- 

 ing the vessels of the sweat gland, and by special secreting 

 fibres supplying the gland itself: under ordinary circum- 

 stances these work together, the bloodvessels dilate and 



the Secreting fibres are active; but it is not. essential to 

 * I have ;ils<> observed sweating to occur immediately after death 



caused by Bhooting through the head. 



