The Pedestrian's Record

the pedestrian'S record. 97 the young man, and the man twenty years old more than his father. The amount of sleep necessary for adults is subject to many and various conditions ; with them it may be granted that the constructive and destructive operations are equallybalanced, and for this reason prolonged slumber, so important to infancy and youth, is no longer requisite. At the same time, although many men are refreshed with sleep of short duration, there are others who are not reinvigorated without prolonged repose : both mental and physical exertion cannot be long continued with­ out sleep ; there is no rest for the brain during waking hours ; thought succeeds thought from the moment we rise until the instant we close our eyes in soporific oblivion; the locomotive system when awake knows little rest, even the movement of the finger represents the destruction of tissue, and excessive physical exertion marks a waste which has to be resupplied; every movement, however limited, is under the control of nervous force; the brain dictates the action which the bones and their pulleys, the muscles, carry into execution. The performance of these functions, being of such constant occurrence^ never receive that amount of consideration which their importance demands, yet they represent the existence of animal life, and prove that the greater the waste the greater will be the necessity for functional activity in making good such loss. We have seen that the constructive function in the infant is principally carried out during sleep, and the waste