to DISEASES Class I. z, i. ii 



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 j as 

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

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

 mufcleS are lefs liable to accumulate fenforial power during their 

 torpor, than others, as the locomotive mufcles compared with 

 the capillary arteries ; 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 fome- 

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

 bath ', and fometimes to a previous exhauftion of the fenforial 

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

 out of a hot room into cold air j 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 

 mud 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 ilow or feeble, 

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

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

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

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

 fo as to counteract its deficient ftimulus, or its previous wade 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 affected 5 or becomes fo great as to 

 overbalance the deficient excitement of it. Gn 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. 



\. Fehvls irritativa. Irritative fever. This is the fynocha of 

 fome writers, it is attended with ftrong pulfe without incarna- 

 tion ; and in this circumftance differs from the febris inirritativa 

 of.CIafsL 2. 1. 1. which is attended with weak pulfe without 

 ilammation. The increafed frequency of the pmfation of the 

 heart and arteries conltitutes fever ; during the cold fit thefe 

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

 creafed throughout the whole fyftem ; and therefore the gener- 

 al 



