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SECT. XVIII. 15. O F S L E E P. 229 



tivity during the day expends much fcnforial power, 

 which is faved during our ileep. 



Hence it appears, that not only thofe parts of the 

 fyftem, which are always excited by internal ftimuli, 

 as the ftomach, inteftinal canal, bile-duds, and the 

 various glands, but the organs of fenfe alfo, may 

 be more violently excited into action by the irrita- 

 tion from internal ftimuli, or by fenfation, during 

 our fleep than in our waking hours j becaufe during 

 the fufpenfion of volition, there is a greater quan- 

 tity of the fpirit of animation to be expended by the 

 other fenforial powers. On this account our irrita- 

 bility to internal ftimuli, and our fenfibility to pain 

 or pleafure, is not only greater in fleep, but increa- 

 fes as our fleep is prolonged. Whence digeflion and 

 fecretion are performed better in fleep, than in our 

 waking hours, and our dreams in the morning have 

 greater variety and vivacity, as our fenfibility in- 

 creafes, than at night when we firft lie down. And 

 hence epileptic fits, which are always occafioned by 

 fomediiagreeable fenfation, fo frequently attack thofe 

 \vho are fubjeft to them, in their fleep ; becaufe at 

 this time the fyftem is more excitable by painful fen- 

 fation in confequence of internal ftimuli j and the 

 power of volition is then fuddenly exerted to relieve 

 this pain, as explained Seel XXXIV. i. 4. 



There is a difeafe, which frequently affects children 

 in the cradle, which is termed ecftafy, and feems to 

 confift in certain exertions to relieve painful fenfa- 

 tion, in which the voluntary power is not fo far ex- 

 cited as totally to awaken them, and yet is fufficient 

 to remove the difagreeable fenfation, which excites itj 

 in this cafe changing the pofture of the child fre- 

 quently relieves it. 



1 have at this time under my care an elegant 

 young man about twenty-two years of age, who fel- 

 dom fleeps more than an hour without experiencing 

 a convuliion fit $' which ceafes in about half a mi- 

 nute 



