SECT. XVIII. 1 6. OF SLEEP. 165 



our during the fufpenfion of volition in fleep. It will be (hewn 

 in another place, that the gout generally firlt attacks the liver, 

 and that afterwards an inflammation of the ball of the great toe 

 commences by aflbciation, and that of the liver ceafes. Now as 

 this change or metaftafis of the activity of the fyflem generally 

 commences in fleep, it follows, that thefe aflbciations of motion 

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

 faculty of aflbciation, like thofe of irritation and of fenfation, be- 

 comes in fome meafure accumulated during the fufpenfion of 

 volition. 



Other affociate tribes and trains of motions, as well as the ir- 

 ritative and fenfitive ones, appear to be increafed in their acliv- 

 ity during the fufpenfion of volition in fleep. As thofe which 

 contribute to circulate the blood, and to perform the various 

 fecretions as well as the aflbciate tribes and trains of ideas, 

 which contribute tofurnifh the perpetual dreams of our dream- 

 ing imaginations. 



In ileep the fecretions have generally been fuppofed to be di- 

 minifhed, as the expectorated mucus in coughs, the fluids dif- 

 charged in diarrhoeas, and in falivation, except indeed the fecre- 

 tion of fweat, which is often vifibly increafed. This error 

 feems to have arifen from attention to the exertions 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 inteftines and lungs into their refpective 

 cavities ; but thefe refervoirs do not exclude thefe fluids imme- 

 diately by their ftimulus, but require at the fame time fome vol- 

 untary efforts, and therefore permit them to remain during fleep. 

 And as they thus continue longer in thofe receptacles in our 

 ileeping 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 quan- 

 tity than in our waking hours. Thus the urine is higher col- 

 oured after long fleep ; which {hews, that a greater quantity 

 has been fecreted, and that more of the aqueous and faline part 

 has been re-abforbed, and the earthy part left in the bladder ; 

 hence thick urine in fevers fhews only a greater action of the 

 vefiels which fecrete it in the kidneys, and of thofe which abforb 

 it from the bladder. 



The fame happens to the mucus expectorated in coughs, 

 which is thus thickened by abforption of its aqueous and faline 

 parts ; and the fame of the feces of the inteftines. From hence 

 it appears, and from what has been faid in No. 15 of this Sec- 

 tion concerning the increafe of irritability and of fenfibility du- 

 ring iieep, that the fecretions are in general rather increafed 



than 



