HOW TO SLEEP 



who has been awake through the night is more likely to 

 relax vigilance and fall asleep then ; for there can be no 

 question that a sleeper who has slept several hours is 

 constantly becoming, under normal conditions, less 

 profoundly unconscious. He is gradually approach- 

 ing the waking-point. It is true indeed that the "vital 

 energy " of the organism as a whole is at its lowest ebb 

 in the early morning hours; but the stored potential 

 energy of the brain whose unloosing results in con- 

 sciousness, is under higher and higher tension as the 

 period of sleep progresses. 



As to the exact conditions existing in the brain during 

 waking periods and during sleep, much is conjectural. 

 In general terms, however, it seems tolerably certain 

 that consciousness is the result of destructive chemical 

 processes in the brain. Along with this destructive 

 action, it is assumed that constructive or reparative 

 processes are also in operation. But it is further as- 

 sumed that during waking hours the destruction ex- 

 ceeds the repair; and that hence arises the necessity 

 for periodical epochs of sleep, during which the de- 

 structive processes shall be in excess. The brain con- 

 sidered as an organ of thought must be, as it were, 

 closed for repairs at pretty regular intervals. In this 

 view, consciousness is present so long as the destructive 

 physical changes in the brain are in excess, and sleep 

 is the period during which recuperative processes are 

 paramount. It would be hard to demonstrate that 

 this statement represents the exact facts, but as a 

 general proposition it is no doubt sufficiently ac- 

 curate. 



