SECRETION. 429 



Drugs. Certain drugs favor sweating. Such are pilocarpine, 

 Calabar bean, strychnine, picrotoxine, muscarine, nicotine, camphor, 

 and the ammonias. Atropine, and morphine in large doses, diminish 

 the secretion. I have found that muscarine and pilocarpine act on 

 the peripheral end of the sudorific nerves. 



Quinine, iodine, arsenic, and mercury, when introduced into the 

 body, reappear in the sweat. 



Although the nerves of the sweat-glands are not anatomically 

 separated from others, yet their concurrence in the secretion is evi- 

 dent. In cutting the cervical sympathetic in a horse there is pro- 

 duced unilateral sweating (Dupuy). According to the increased 

 intensity with which the cervical sympathetic is galvanically excited 

 through the skin of man, there follows a lowered or increased per- 

 spiration of the corresponding side of the face. These facts, to- 

 gether with the known dilatation of the cutaneous vessels in profuse 

 perspiration, show the influence of the vasomotor nerves. 



Goltz and others have shown that by exciting the nerve of a 

 limb the perspiration of it can be increased through the action of 

 sudorific nerve-fibers. The same results have been attained even 

 though the limb has been previously amputated and therefore no 

 longer subject to circulation. It appears that the vasomotor and 

 sudorific nerve-fibers run in the nerves by themselves. 



Stimulating in man a motor nerve, such as the tibial, median, 

 or facial, the part corresponding to the active muscles would per- 

 spire, even upon the side not excited. Vulpian and Ott have made 

 experiments tending to prove the existence of inhibitory fibers of 

 sweat. 



The excretion of sweat takes place through vis a tergo, aided by 

 the concurring contraction of the interlaced muscular fibers in the 

 glandular glomerules. Besides, a kind of aspiration is exercised at 

 the mouth of the gland by the evaporation of the liquid which arrives 

 there. It is for this latter reason that air saturated with vapor 

 slackens perspiration, especially when the other causes of transpira- 

 tion do not act very strongly. 



In the normal state the sweat and urine vary in quantity with 

 the season; in the spring the sweat predominates over the urine, in 

 winter the reverse is true. There is an inverse relation between the 

 sweat and intestinal secretions. There is a very noticeable balancing 

 between the sweats and diarrhoea of phthisis. 



By varnishing the body death is caused. This does not occur ly 

 retention of poisonous principles in the Uood. There are functional 



