SBCT. XXXII. 10. DISEASES OF IRRITATION. 445 



gradually recovers its natural degree of irritabi- 

 lity. 



4. But if the increafe of irritability, and the con- 

 fequent increafe of the itimulus of heat and mo- 

 mentum, produce more violent exertions than thofe 

 above defcribed ; great pain arifes in fome part of 

 the moving fyftem, as in the membranes of the 

 brain, pleura, or joints ; and new motions of the 

 veflels are produced in coniequence of this pain, 

 which are called inflammation ; or delirium or ftu- 

 por arifes ; as explained in Sect. XXI. and XXXIII. : 

 for the immediate effect is the fame, whether the 

 great energy of the moving organs arifes from an 

 increafe of ftimulus or an increafe of irritability ; 

 though in the former cafe the waile of fenforial 

 power leads to debility, and in the latter to health. 



Recapitulation. 



X. Thofe mufcles, which are lefs frequently ex- 

 erted, and whofe actions are interrupted by fleep, 

 acquire lefs accumulation of fenforial power during 

 their quiefcent ftate, as the mufcles of locomotion. 

 In thefe mufcles after great exertion, that is, after 

 great exhauftion of fenforial power, the pain of fa- 

 tigue 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 uueafmefs occafioned by want of exercife'; 

 and which in young animals is one caufe exciting 

 them into action, as is feen in the play of puppies 

 and kittens. 



But when thofe mufcles, which are habituated 

 to perpetual actions, as thofe ot the ftomach by the 

 ftimulus of food, thofe of the veflels of the (kin by 



G g the 



