ART. II. 2. i. 8. SECERNENTIA. 35 



tient be kept in a moderate warm bed, will in a few hours 

 elicit moft profufe fweats. 



N.utral falts promote invifible perfpiration, when the ikin is 

 not warmed much externally, as is evinced from the great third, 

 which fucceeds a meal of fait provifions, as of red herrings. 

 When thefe are fufficiently diluted with water, and the (kin 

 kept warm, copious fweats without inflaming the habit, are the 

 cor.fequence. Half an ounce of vinegar faturated with volatile 

 alkali, taken every hour or two hours, well anfwers this pur- 

 pole j and is preferable perhaps in general to all others, where 

 {wearing is advantageous. Boerhaave mentions one cured of 

 a fever by eating red -herrings or anchovies, which, with repeat- 

 ed draughts of warm water or tea, would I fuppofe produce co- 

 pious perfpiration. 



Antimonial preparations have alfo been of late much ufed 

 with great advantage as diaphoretics. For the hiftory and ufe 

 of thele preparations I fhal< refer the reader to the late writers 

 on the Materia Medica, only obferving that the ftomach be- 

 comes fo foon habituated to its (limulus, that the fecond dole 

 may be confiderably increafed, if the firft had no operation. 



Where it is advifable to procure copious fweats, the emetics, 

 as ipecacuanha, joined with opiates, as in Dover's powder, pro- 

 duce this effect with greater certainty than the above. 



8. We mud not difmifs this fubjecT: without obferving, that 

 perfpiration is defigned to keep the (kin flexible, as the tears are 

 intended to clean and lubricate the eye ; and that neither of 

 thefe fluids can be confidered as excretions in their natural ftnte, 

 but as fecretions. See Clafs I. 1.2. 3. And that therefore 

 the principal ufe of diaphoretic medicines is to warm the (kin, 

 and thence in confequence to produce the natural degree of in- 

 fenfible perfpiration in languid habits. 



y. When the ikin of the extremities is cold, which is always 

 a fign of prefent debility, the digeftion becomes frequently im- 

 paired by aflbciation, and cardialgia or heartburn is induced 

 from the vinous or acetous fermentation of the aliment. In this 

 difeafe diaphoretics, which have been called cordials, by their 

 aclionon the ftomach reftore its exertion, and that of the cu- 

 taneous capillaries by their aflbciation with it, and the (kin be- 

 comes warm, and the digeftion more vigorous. 



10. But a blifter acls with more permanent and certain ef- 

 feel by ftimulating a part of the ikin, and thence aftecling the 

 whole of it, and of the ftomach by aflbciation, and thence re- 

 moves the moft obftinate heartburns and vomitings. From 

 this the principal ufe of blifters is underftood, which is to in- 

 vigorate the exertions of the arterial and lymphatic veflels of the 



ikin, 



