AND PHYSIOLOGY. 



053 



requires sound sleep. For this alone can return to the brain 

 its expended energies. It is as necessary to the brain as 

 steam to the locomotive. And no person can enjoy the per- 

 fection of health to old age, who does not gain a due supply 

 of sleep. Hence the very ambitious student, or the man eager 

 to make money, whose time, energies and thoughts are so 

 engrossed that he can not, or will not, find time to sleep, vio- 

 lates one of nature's principal laws, and sooner or later will 

 receive the penalty. And, according to insane hospital re- 

 ports, one of the principal causes of insanity is put down to a 

 want of sleep. 



645. Needs Rest and Recreation. — 4. The mind not only 

 needs sleep, but also recreation or an occasional change of its 

 objects of thought. Long-continued trains of thought are to 

 the brain what working one set of muscles incessantly all day 

 is to them — complete exhaustion. He then that would last 

 the longest, must occasionally turn his thoughts from his or- 

 dinary avocation completely, and so give the brain rest. This 

 applies to every one, whether he is the business man, student, 

 or the hard-working farmer or mechanic. And every one 

 also needs a vacation, or at least some change of employment, 

 once or twice during the year, when, for a few weeks or days, 

 he may break up the ordinary routine of life. 



646. Necessity of various Objects for the Mind to di- 

 vert itself with. — 5. If change or recreation be so impor- 

 tant for the health, how necessary that the mind should have 

 various objects on which to employ itself when free from daily 

 duties. How pleasantly, and profitably, for instance, can 

 one pass his leisure hours, if he will but cultivate a taste 

 for music, reading, or some branch of natural history, as for 

 example zoology, botany, mineralogy, or geology! These 

 pursuits not only give healthful physical recreation, but by 



644. What is the effect of a want or scarcity of sleep ? What is often a prominent 

 cause of insanity ? 645. What kind of rest does the mind need besides sleep? Do all 

 employments need a vacation ? 646. Is exercise, that is taken simply for exercise, ever 

 the best ? What studies combine profit as well as recreation and exercise ? 



