Skct. XVIIJ. 16. O F S L E P. 253 



greater energy at that time; that is, that the fenforial 

 faculty of aftoc'ation, like thofe of irritation and of 

 fenfation, becomes in fome meafure accumulated 

 during the fufpenfion of volition. 



Other aflbciate tribes and trains of motions, as 

 well as the irritative and fenfitive ones, appear to 

 be increafed in their activity during the fufpenfion 

 of volition in fleep. As thofe which contribute to 

 circulate the blood, and to perform the various fe- 

 cretions ; as well as the aflbciate tribes and trains of 

 ideas, which contribute to furnifli the perpetual 

 ilreams of our dreaming imaginations. 



In fleep the fecretions have generally been fup- 

 pofed to be diminifhed, as the expectorated mucus in 

 coughs, the fluids difcharged in diarrhceas, and in 

 falivaticn, except indeed the fecretion of fweat, 

 which is often vifibly increafed. This error feems to 

 have arifen from attention to the excretions rather 

 than to the fecretions. For the fecretions, except 

 that of fweat, are generally received into refervoirs, 

 as the urine into the bladder, and the mucus of the 

 interlines and lungs into their refpeclive cavities ; 

 but thefe refervoirs do not exclude thefe fluids im- 

 mediately by their ftimulus, but require at the fame 

 time fome voluntary efforts, and therefore permit 

 them to remain during fleep. And as they thus 

 continue longer in thofe receptacles in our fleeping 

 hours, a greater part is abforbed from them, and the 

 remainder becomes thicker, and fometimes in lefs 

 quantity, though at the time it was fecreted the fluid 

 was in greater quantity than in our waking hours. 

 -Thus the urine is higher coloured after long fleep ; 

 which fhews, that a greater quantity has been fe- 

 creted, and that more of the aqueous and faline part 

 has been reabfcrbed, and the earthy part left in the 

 bladder ; hence thick urine" in fevers ihews only a 

 greater action of the veflels which fecrete it in the 

 kidneys, and of thofe which abforb it from the blad- 

 der. 



$2, The 



