14 DISEASES- CLASS I. 1. 2- 3' 



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

 of the arteries coalesce, and become impervious, and thus add 

 to the opacity of the skin. 



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

 rieties, according to its remote causes. First, the perspirable 

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

 as towards the end of it, when the sweat is seen upon the skin. 

 But during the hot fit the cutaneous absorbents act also with in- 

 creased energy, and the exhalation is likewise increased by the 

 greater heat of the skin; and hence it does not appear in drops 

 on the surface, but is in part re-absorbed, and in part dissipated 

 in the atmosphere. But as the mouths of the cutaneous absorb- 

 ents are exposed to the cool air or bed clothes; whilst those of 

 the capillary glands, which secrete the perspirable matter are ex- 

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

 soon as the fever-fit begins to decline, lose their increased action 

 first, and hence the absorption of the sweat is diminished, 

 whilst the increased secretion of it continues for some hours af- 

 terwards, which occasions it to stand in drops upon the skn. 



As the skin becomes cooler, the evaporation of the perspira- 

 ble matter becomes less, as well as the absorption of it. And 

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

 consequent thirst, are perhaps greater during the hot fit, than 

 during the subsequent sweat. For the sweats do not occur, ac- 

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

 from 112 to 108 degrees of heat; that is till the paroxysm be- 

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

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

 critical to the cold one; but simply, that they are the natural 

 consequence of the decline of the hot fit commencing with the 

 decreased action of the absorbent system, and the decreased eva- 

 poration from the skin. And from hence it may be concluded, 

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

 health, as Sydenharn considered it, but a necessary consequence 

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

 less detrimental, if the fever itelf could be prevented from ex- 

 isting; as appears in the cool treatment of the small-pox. 



It must be noted that the profuse sweats on the skin are more 

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

 loose stools, which are mentioned below; as the cutaneous ab- 

 sorbents, being exposed to the cool air, loose their increased ac- 

 tion sooner than the urinary or intestinal absorbents; which 

 open into the warm cavities of the bladder and intestines; but 

 which are nevertheless often affected by their sympathy with the 

 cutaneous absorbents. Hence few fevers terminate without a 



