54 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 fenforiai power continues the fame in re- 

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

 going into a darkifh room, or into a coldiih bath, fuppofe of a- 

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

 nefs of the affected fibres is induced, till an accumulation of fen- 

 foriai power gradually fucceeds, and counterbalances the de- 

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

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

 cutaneous veilcls, or of the organs of fenfe, act with their ufu- 

 al energy. 



A fet of mufcular fibres may thus be ftimulated into violent 

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

 fenforiai power, but may neverthelefs not act ftrongly ; becaufe 

 the quantity of their fenforiai power was originally fmall, or 

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

 the irritation in confequence act with its full force, as in the hot 

 paroxyfm s of nervous fever ; but if the fenforiai power, termed 

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

 tions, and the times of their continuance in their contracted 

 Hate, will be proportionally fmall. 



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

 which are (hewn in Sect. XXXIII. to be inflammatory fevers 

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

 erted with great activity, yet the fibrous contractions, which 

 produce the circulation of the blood, are performed without 

 Strength, becaufe the quantity of fenforiai 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 ftimulus, and the quantity of fenforiai 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 fenforiai powers, which are 

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

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

 moving fibres, and the fenforiai power of fenfation excited by 

 the pain in confequence of the increafed contractions of thofe 

 moving fibres. 



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



lar actions wiil be in proportion to the quantity of fenforiai 

 .pow Ich they pofiefs, and thexmantity of the ftimulus of 



defire 



