4 

 *6 * -# DISEASES ClassI. i. 2. ' 



■ v 



veflels, "which are generally cooler than the internal parts of tl 

 fyttem, excitel them into grcati on ; and pleafurable fenfa- t 



tion is the confequence oi thefejnereafed actions of the veiled 

 of the fkin. From confidering all thefe circumftances, it ap- 

 pears that it is not the evacuation by fweats, but the continued 

 stimulus, which caufes and fupports thofe fweats, which is fer- 

 viceable in preventing the returns of fever-fits. And that fweats 

 too long continued, or induced by too great (limulus of warmth, 

 clothes, or medicines, greatly injure the patient by increafing in- 

 flammation, or by exhaufting the fenforial power. See Clafs I. 

 i. 2. 14. 



Secondly > The fweats produced bv exercife or labour are of 

 the warm kind ; as they originate from the increafed action of 

 the capillaries of the (kin, owing to their being more powerfully 

 stimulated by the greater velocity of the blood, and by a greater 

 quantity of it pamng through them in a given time For the 

 blood during violent exerciie is carried forwards by the action 

 of the mufcles falter in the arteries, than it can be taken up by 

 the veins ; as appears by the rednefs of the fein. And from 

 the confequent fweats, it is evinced, that the fecretory vefTels. of 

 the ikin during exercife pour out the perfpirable matter falter, 

 than the mouths of the abforbent veffels can drink it up. "Which 

 mouths are not expofed to the increafed mufcular adtion, or to 

 the ftimulus of the increafed velocity and quantity of the blood, 

 but to the cool air. 



Thirdly, the increafed fecretion of perfpirable matter occafion- 

 ed by the ftimulus of exteral heat belongs like wife to this place > 

 as it is caufed by the increafed motions of the capillary veiTeis ; 

 which thus feparate from the .blood more perfpirable matter, 

 than the mouths of their correfpondent abforbent veifels can take 

 up •, though thefe alfo are ftimulated by external heat into more 

 energetic action. If the air be ftationary, as in a fmall room, 

 or bed with clofed curtains, the fweat (lands' in drops on the Ikin 

 for want of a quicker exhalation proportioned to the quicker fe- 

 cretion. 



A fourth variety of warm per fp nation is that occafioned by 

 stimulating drugs, of which opium and alcohol are the mofl 

 powerful ; and next to thefe the fpices, volatile alkali, and neu- 

 tral falts, efpecially fea-fak; that much of the aqueous part of 

 the blood is dimpated by the ufe of thefe drugs, is evinced by the 

 great thirft, which occurs a few hours after the ufe of them. See 

 Art. III. 2. 1. 



We may from hence underftand, that the increafe of this 

 fecretion of perfpirable matter by artificial means, mult be fol- 

 lowed by debility and emaciation. "When this is done by taking 



II. much 



