CLASS II. i. i. OF SENSATION. 151 



CLASS II. 



DISEASES OF SENSATION. 



ORDO I. 



Inert afed Setifatwn. 

 GENUS I. 



With increafed Action of the Mufcles. 



THE actions belonging to this genus are thofe which are im- 

 mediately excited by the fenfations of pain or pleafure, but 

 which are neither followed by inflammation nor by convulfion. 

 The former of which belong to the fubfequent genera of this 

 order, and the latter to the clafs of voluntary motions. 



The criterion between the actions, which are the immediate 

 confequence of painful fenfation, and convuUive actions prop- 

 erly fo called, confifts in the former having a tendency to dif- 

 lodge the ftimulating caufe, which induces the painful fenfation ; 

 and the latter being exerted for the purpofe of expending the 

 fenforial power, and thus dulling or deftroying the general fen- 

 fation of thefyftem. See Clafs III. i. 



There is a degree of heat produced in the affected part by 

 thefe fenfitive actions without inflammation, but in much leis 

 quantity than when attended by inflammation ; as in the latter 

 there is production of new vefTels. See Sett. XXXIII. 2. 3. 



Some of the fpecies of this genus cannot properly be termed 

 difeafes in their natural ftate, but become fo by their defeat or 

 excefs, and are here inferted to facilitate the explanation of the 

 others. 



SPECIES. 



i. Degltttiiio. Swallowing our food is immediately caufed 

 by the pleafurable fenfation occafioned by its iiimulus on the 

 palate or fauces, and is acquired long before the nativity of the 

 animal. Afterwards the pain of hunger previoufly produces 

 the various voluntary exertions to procure the proper material, 

 but the actions of mafiicating and of fwallowing it are effected 

 by the fenforial power of fenfation ; which appears by their not 

 being always controlable by the will, as when children in vain 

 attempt to fwallow naufeous drugs. See Clafs IV. i. 3. i. 



The- 



