340 DISEASES CLASS III. 2. i. 11. 



the pulfe, which fometimes occurs in ileep, 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 circumitances 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 1 take a recumbent pofture af- 

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

 mind be vacant, and I become drowfy ; and, if I flumber, 

 this increafed frequency is more confiderable with heat and 

 fiufhing. 



" 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 fupper 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 part from your principles. When the power 

 of volition is abblifhed, 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 fyftem falter than it is expended ; and 

 operating on the fenfitive actions, it carries them beyond the 

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

 increafed frequency of pulfe. 



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

 under thefe circum (lances, I do not allude to any chemical evo- 

 lution of keat 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 ikin. The parts 

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

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

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

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

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

 fatibn of heat, a fenfation increafed by the great fen fibility of the 

 parts affected. 



c; That the increafed heat excited by digeftion in flccp is the 



caufe 



