34° 



DISEASES Class HI. su 1. i*. 



the pulfe, which fomctimes occurs in fleep, are copied from a 

 letter of Dr. Currie of Liverpool to the author. , 



« Though reft in general perhaps renders the healthy- pulfe 

 flower, yet under certain circumftances the contrary is the truth. 

 A full meal without wine or other ftrong liquor does not in- 

 creafe the frequency of my pulfe, while I fit upright, and have 

 my attention engaged. But if I take a recumbent pofture af- 

 ter eating, my pulfe becomes more frequent, efpecially if my 

 mind be vacant, and I become drowfy 5 and, if I flurnber, 

 this increafed frequency is more confiderable with heat and 

 fluihing. 



" This I apprehend to be a general truth. The obfervation 

 may be frequently made upon children ; and the reftlefs and fe- 

 verifh nights experienced by many people after a full flipper are, 

 I believe, owing to this caufe. The fupper occafions no incon- 

 venience, whilft the perfon is upright and awake -, but, when 

 he lies down and begins to fleep, efpecially if he does not per- 

 fpire, the fymptoms above mentioned occur. Which may be 

 thus explained in parr from your principles. When the power 

 of volition is abolimed, the other fenforial actions are increafed. 

 In ordinary fleep this does not occafion increafed frequency of 

 the pulfe ; but where fleep takes place during the procefs of di- 

 geftion, the digeftion itfelf goes on with increafed rapidity. 

 Heat is excited in the fyflem falter than it is expended 5 and 

 operating on the fenfitive actions, it carries them beyond the 

 limitation of pleafure, producing, as is common in fuch cafes, 

 increafed frequency of puife. 



" It is to be obferved, that in. fpeaking of the heat generated 

 under thefe circumftances, I do not allude to any chemical evo- 

 lution of heat from the food in the procefs of digeftion. I doubt 

 if this takes place to any confiderable degree, for I do not ob- 

 ferve that the parts incumbent on the ftomach are increafed in 

 heat during the moft hurried digeftion. It is on fome parts of 

 the furface, but more particularly on the extremities of the body, 

 that the increafed heat excited by digeftion appears, and the 

 heat thus produced arifes, as it mould feem, from the fympa- 

 thy between the ftomach and the veflels of the fkin. The parts 

 moft affected are the palms of the hands, and the foles of the 

 feer. Even there the thermometer feldom rifes above 97 or 98 

 degrees, a temperature not higher than that of the trunk of the 

 body j but three or four degrees higher than the common tem- 

 perature of thefe parts, and therefore producing an uneafy fen- 

 fation of heat, a fenfation increafed by the great fenfibility of the 

 parts affected. 



M That the increafed heat excited by digeftion in fleep is the 



caufe 



