:4 DISEASES CLASS I. i. 2. 3. 



probable, that in more advanced life fome of the finer branches 

 of the arteries coalefce, and become impervious, and thus add to 

 the opacity of .the fkin. 



3. Sudor calidus. Warm fweat may be .divided into four va- 

 rieties, according to its remote caufes. Firft y the perfpirable 

 matter is feoreted in as great quantity during the hot fit of fever, 

 as towards the end of it, when the fweat is feen upon the fkin. 

 But during the hot jit the cutaneous ab foments act alfo with in- 

 creaied energy, and the exhalation is likewife increafed by the 

 greater heat of the fkin j and hence it does not appear in drops 

 on the furface, but is in part re-abforbed, and in part diflipated 

 in the atmofphere. But as the mouths of the cutaneous abforb- 

 ents are expofed to the cool air or bedclothes ; whilft thofe of 

 the cr.piiiary glands, which fecrete the perfpirable m.itter, are ex- 

 pofed to the warmth of the circulating blood ; the former, as 

 foon as the fever-fit begins to decline, lofe their increafed action 

 firft, and hence the abiorption of the fweat is diminiihed, whild 

 the incr.eafed fecretion of it continues for fome hours afterwards, 

 which occafions it to ftand in drops upon the fkin. 



As the /kin becomes cooler, the evaporation of the perfpira- 

 ble matter becomes lefs, as \vell as the abforption of it. And 

 hence the diffipation of aqueous fluid from the body, and the 

 confequent third, are perhaps greater during the hot fit, than 

 during the fubfequent fweat. For the fweats do not occur, ac- 

 cording to Dr. Alexander's experiments, till the {kin is cooled 

 from 1 12 to 1 08 degrees of heat ; that is, till the paroxyfm be- 

 gins to decline. From this it appears, that the fweats are not 

 critical to the hot fit, any more than the hot fit can be called 

 critical to the cold one -, but fimply, that they are the natural 

 confluence of the decline of the hot fit, commencing with the 

 decreafed action of the abforbent fyftem, and the decreafed evap- 

 oration from the (kin. And from hence it may be concluded, 

 that a fever-fit is not in general an effort of nature to reftore 

 health, as Sydenham confidered it, but a neceffary confequence 

 of the previous torpor ; and that the caufes of fevers would be 

 lefs detrimental, if the fever itfelf could be prevented from exj(l> 

 ing , as appears in the cool treatment of the fmall-pox. 



It muft be noted that the profufe fweats on the 1km are more 

 frequent at the decline of fever-fits than the copious urine, or 

 looie ilools, which are mentioned below ; as the cutaneous ab- 

 forbents, being expofed to the cool air, lofe their increafed ac- 

 tion {boner than the urinary or inteflinal abforbents *, which 

 open inro the warm cavities of the bladder and inteftines ; but 

 which are neverthelefs often affected by their fympathy with the 

 cutaneous abforbents. Hence few fevers terminate without a 



moiilure 



