$4 OF STIMULUS SECT. XII. 2. i. 



in nervous fevers, the arterial contractions may be performed 

 more frequently than natural, yet with lefs ftrength. 



And thirdly, if the fenforial power continues the fame in re- 

 fpeft to quantity, and the ftimulus be fomewhat diminifhed, as in 

 going into a darkifti room, or into a coldifn bath, fuppofe of a- 

 bout eighty degrees of heat, as Buxton-bath, a temporary weak- 

 nefsof the affected fibres is induced, till an accumlation of ien- 

 forial power gradually fucceeds, and counterbalances the de- 

 ficiency of ftimulus, and then the bath ceafes to feel cold, and 

 the room ceafes to appears dark ; becaufe the fibres of the fub- 

 cutaneous veflels, or of the organs of fenfe, aft with their ufu- 

 al energy. 



A fet of mufcular fibres may thus be ftimulated into violent 

 exertion, that is, they may aft frequently, and with their whole 

 fenforial power, but may neverthelefs not acl: ftrongly ; becaufe 

 the quantity of their fenforial power was originally fmall, or 

 was previoufly exhaufted. Hence a ftimulus may be great, and 

 the irritation in confequerice aft with its full force, as in. the hot 

 paroxyfms of nervous fever ; but if the fenforial power, termed 

 irritation, be fmall in quantity, the force of the fibrous contrac- 

 tions, and the times of their continuance in their contracted 

 ftate, will be proportionally fmall. 



In the fame manner in the hot paroxyfm of putrid fevers, 

 which are fhewn in Seft. XXXIII. to be inflammatory fevers 

 with arterial debility, the fenforial power termed fenfation is ex- 

 erted with great aftivity, yet the fibrous contractions, which 

 produce the circulation of the blood, are performed without 

 ftrength, becaufe the quantity of fenforial power then refiding 

 in that part of the fyftem is fmall. 



Thus in irritative fever with arterial ftrength, that is, with 

 excefs of fpirit of animation, the quantity of exertion during 

 the hot part of the paroxyfm is to be eftimated from the quan- 

 tity of itimulus, and the quantity of fenforial power, while in 

 fenfitive (or inflammatory) fever with arterial ftrength, that is, 

 with excefs of fpirit of animation, the violent and forcible ac- 

 tions of the vafcular fyftem during the hot part of the paroxyfm 

 are induced by the exertions of two fenforial powers, which are 

 excited by two kinds of ftimulus. Thefe are the fenforial pow- 

 er of irritation excited by the ftimulus of bodies external to the 

 moving fibres, and the fenforial power of fenfation excited by 

 the pain in confequence of the increafed contractions of thofe 

 moving fibres. 



And in infane people in fome cafes the force of their mufcu- 

 lar aft ions will be in proportion to the quantity of fenforial 

 power, which they poifefs, and the quantity of the ftimulus of 



defire 



