420 DISEASES OF IRRITATION, SECT. XXXII, 3. 



pulfation of the heart and arteries becomes doubled; 

 which, however, is never the cafe, in fevers with 

 ftrength, in which they feldom exceed 118 or 120 

 pulfations in a minute. It mufl be added, that in 

 thefe cafes, while the pulfe is very fmall anid very 

 quick, the heart often feels large, and labouring to 

 one's hand ; which coincides with the above expla- 

 nation, (hewing that it does no,t completely empty 

 itfelf. 



3. In cafes however of debility from paucity of 

 blood, as in animals which are bleeding to death 

 in the fiaughter-houfe, the quick pulfations of the 

 heart and arteries may be owing to their not being 

 diftended to more than half their ufoal diaftole ; 

 and in confequence they njuft contract fooner, or 

 more frequently, in a given tiifle.. As weak people 

 are liable to a deficient quantity of blood, this 

 caufe may occalionally contribute to quicken the 

 pulfe in fevers with debility, which may be known 

 by applying one's hand upon the heart as above ; 

 but the principal caufe I fuppofe to confift in the 

 diminution of fenforial power. When a mufcle 

 contains, or is fupplied with but little fenforia^ 

 power, its contraction foon ceafes, and in confe- 

 quence may foon reftir, as is feen in the trernbling 

 hands of people weakened by age or by ch'Uflken- 

 nefs. See Sea. XII. i. 4. XII. 3. 4. 



It may neverihelefs frequently happen, that both 

 the deficiency of ilimulus, as where the quantity 

 of blood is leflened (as defcribed in No. 4. of this 

 fe6tion), and the deficiency of fenforial power, as 

 in thofe of the temperament of inirritability, de- 

 icribed in Se6l. XXXI. occur at the fame time j 

 which will thus add to the quicknefs of the pulfe 

 and to the danger of the difeafe. 



III. i. A certain degree of heat is ncceffary to 

 mufcular motion, and is, in confequence, effential 

 to life. This is obferved in thofe animals and infec~h 



which 



