SECT. XXXII. i. i. OF IRRITATION 301 



Recapitulation. 



X. Thofe mufcles which are lefs frequently exerted, and 

 whofe actions are interrupted by deep, acquire lefs accumulation 

 of enforial power, during their quiefcent ftate, as the mufcles 

 of locomotion. In thefe mufcles after great exertion, that is, 

 after great exhauftion of the fenforial power, the pain of fatigue 

 enfues *, and during reft there is a renovation of the natural 

 quantity of fenforial power ; but where the reft, or quiefcence 

 of the mufcle, is long continued, a quantity of fenforial power 

 becomes accumulated beyond what is neceflary ; as appears by 

 the uneafinefs occafioned by want of exercife ; and which in 

 young animals is one caufe exciting them into ation, as is feen 

 in the play of puppies and kittens. 



But when thofe mufcles, which are habituated to perpetual 

 actions, as thofe of the ftomach, by the ftimulus of food, thofe 

 of the veffeis of the fkin by the ftimulus of heat, and thofe which 

 conftitute the arteries and glands by the ftimulus of the blood, 

 become for a time quiefcent, from the want of their appropria- 

 ted ftimuli, or by their aflbciation with other quiefcent parts of 

 the fyitem ; a greater accumulation of fenforial power is ac- 

 quired during their quiefcence, and a greater or quicker ex- 

 hauition of it is produced during their increafed action. 



This accumulation of fenforial power from deficient action, 

 if it happens to the ftomach from want of food, occafions the 

 pain of hunger ; if it happens to the vefTels of the fkin from 

 want of heat, it occafions the pain of cold ; and if to the arterial 

 fyftem from the want of its adapted ftimuli, many difagreeable 

 fenfations are occafioned, fuch as are experienced in the cold fits 

 of intermittent fevers, and are as various as there are glands or 

 membranes in the fyftem, and are generally termed univerfal 

 uneafinefs. 



When the quiefcence of the arterial fyftem is not owing to de- 

 fect of ftimulus as above, but to the defective quantity of fenfo- 

 rial power, as in the commencement of nervous fever, or irrita- 

 tive fever with weak pulfe, a great torpor of this fyftem is 

 quickly induced ; becaufe both the irritation from the ftimulus 

 or the blood, and the aflbciations of the vafcular motions with 

 each other, continue to excite the arteries into action, and thence 

 quickly exhauft the iil-fupplied vafcular mufcles ; for to reft 

 is death , and therefore thofe vafcular mufcles continue to pro- 

 ceed, though with feebler action, to the extreme of wearinefs 

 or faintnefs : while nothing fimilar to this affects the locomo- 

 tive mufcles, whofc aft ions are generally caufed by volition, and 



not 



