464 THEORY OF FEVER. SUP. 1. 8. j. 



nefs and coldnefs of the (kin, and alfo by the pain of coldnefs, 

 which attends it. There is neverthelefs in mod cafes, except 

 tkofe which are owing to expofure to external cold, a torpor of 

 the capillaries of fome internal vifcus preceding this inactivity 

 of the cutaneous capillaries ; which is known by the tumour or 

 hardnefs of the vifcus, or by an aching pain of it. The capilla- 

 ries of the lungs are at the fame time rendered inactive or tor- 

 pid, as appears by the difficulty of breathing, and coldnefs of 

 the breath in cold fits of fever, and in going into the cold bath ; 

 but the lungs are not affected with the pain either of coldnefs or 

 of torpor. 



One caufe of this fynchronous or fucceflive inactivity of the 

 cutaneous capillaries, in confequence of the previous torpor of 

 fome internal vifcus, may be owing to the deficiency of heat ; 

 which muft occur, when any part becomes inactive ; becauie 

 the fecretions cf that part ceafe or are leffened, and the quantity 

 of heat of it in confequence. But the principal caufe of it I 

 fuppofe to be owing to the defect of the fenforial power of af- 

 fociation ; which power of affociation is excited by fome pre- 

 vious or concomitant motions of the parts of every great circle 

 of actions. This appears on going into the cold bath, becaufe 

 the fhortnefs of breath inflantly occurs, fooner than one can con- 

 ceive the diminution of the heat of the fkin could affect the lungs 

 by the want of its llimulus ; but not fooner than the defect of the 

 fenforial power of affociation could affect diem ; becaufe this 

 mud ceafe to be excited into action on the inftant that the cu- 

 taneous capillaries ceafe to act ; whence in the firft moment of 

 contact of the cold water the cutaneous capillaries ceafe to act 

 from defect of irritation ; which is caufed by defect of the ftim- 

 ulus of heat ; and in the fecond moment the capillaries of the 

 lungs ceafe to act from the defect of affociation j which is cauf- 

 ed by the defect of the motions of the cutaneous capillaries. 

 Thus the univerfal torpor in the cold paroxyfm of fever is an ex- 

 ample of direct fympathy, though occasioned in part by defect 

 of irritation, and in part by defect of affociation. 



5. Thus in walking out in a frofty morning the fkin is cool- 

 ed by the contact of the cold air, whence the actions of its ca- 

 pillaries are diminifhed for want of their ufual itimulus of heat 

 to excite a fufficient quantity of the fenforial power of irritation. 

 Hence there is at firft a faving of the fenforial power of irrita- 

 tion for the purpofe of actuating the other parts of the fyflem. 

 with greater energy. Secondly, the fenforial power of affocia- 

 tion, which ufed to be excited by the motions of the cutar: 

 capillaries, is now not fo powerfully excited ; and in confequenc^ 

 rh<- pirts.. \vhich ronflitutc the nest links of the circles of aflb- 



ciated 



