MODIFY SLEEP. 949 



state of the brain, that may be relieved by cold 

 applications to the head, putting the feet in warm 

 water, and then getting into a warm bed all of 

 which tend to equalize the circulation, diminish 

 the morbid activity of the brain, and thus induce 

 sleep. 



It is maintained by Dr. Billing, that a warm 

 bed is favourable to sleep, by causing a plethoric 

 state of the brain. (Principles of Med. p. 80.) 

 But according to the observations of Blumen- 

 bach, the circulation is diminished in the brain, 

 and its vessels less turgid during sleep than 

 when we are awake. Hence it is that strong 

 tea and coffee prevent sleep, by augmenting 

 the circulation and activity of the brain, or 

 that when the blood is determined from the 

 surface and extremities by sleeping in a cold 

 bed, and sent to the brain in augmented quan- 

 tities, we are kept awake until the circulation is 

 equalized by warmth. Sleep is more sound 

 during the early part of night, when the nu- 

 tritive process is actively employed in repairing 

 the previous waste, than towards morning, when 

 it is often partially interrupted by dreams. Long 

 before the philosophy of mind had been rescued 

 from the reveries of metaphysics, by the dis- 

 coveries of Dr. Gall, it was known that the 

 different senses sleep in succession, and with 

 different degrees of intensity that in cases of 

 partial somnolency, individuals are capable of 

 hearing, and even of answering questions, when 



