io . DISEASES ^ CLASS I. i. i. * 



they are, where no part is deftroyed by the cold fit, as in morti- 

 fication or death. But we have no meafure to diftinguifli this, 

 except the time of their duration , whereas the extent of the 

 torpor over a greater or lefs part of the fyftem, which occafions 

 the cold fit ; or of the exertion which occafions the hot one , as 

 well as the degree of fuch torpor or exertion, are perhaps more 

 material than the time of their duration. Befides this, fome 

 rnufcles are lefs liable to accumulate fenforial power during their 

 torpor, than others, as the locomotive mufcles compared with 

 the capillary arteries j on all which accounts a long cold fit may 

 often be followed by a fhort hot one. 



As the torpor, with which a fit of fever commences, is feme- 

 times^ owing to defeft of ftimulus, as in going into the cold- 

 bath 5 and fometimes to a previous exhauflion of the fenforial 

 power by the action of fome violent ftimulus, as after coming 

 out of a hot room into cold air , a longer time muft elapfe, be- 

 fore there can be a fufficient accumulation of fenforial power to 

 produce a hot fit in one cafe than in the other. Becaufe in the 

 latter cafe the quantity of fenforial power previoufly expended 

 rnuft be fupplied, before an accumulation can begin. 



The cold paroxyfm commences, when the torpor of a part be- 

 comes fo great, and its motions in confequence fo flow or feeble, 

 as not to excite the fenforial power of affociation 5 which in 

 health contributes to move the reft of the fyftem, which is ite- 

 nated with it. And the hot fit commences by the accumulation of 

 the fenforial power of irritation of the part firft affected, either 

 ib as .to counteract its deficient ftimulus, or its previous wafte of 

 fenforial power ; and it becomes general by the accumulation of 

 the fenforial power of afTociation ; which is excited by the reno- 

 vated -actions of the part firft affeded j or becomes fo great as to- 

 overbalance the deficient excitement cf it. On all thefe accounts 

 the hot fit cannot be fuppofed to bear any proportion to the cold 

 one in length of time, though the latter may be the confequence 

 of the former. See Suppl. I. 16. 8. 



SPECIES. 



1. Felris irritativa. Irritative fever. This is the fynocha of 

 fome writers, it is attended with ftrong piilie without inflama- 

 tion ; and in this circumftance differs from the febris inirritativa 

 ofClalsI. 2. i. T. which is attended with weak pulfe without 

 inflammation. The increafed frequency of the pulfation of the 

 heart and arteries conftitutes fever ; during the cold fit thefe 

 pulfations are always weak, as the energy of action is then de- 

 d throughout the whole fyftem , and therefore the gener- 

 al 



