THE NERVOUS SYSTEM 



229 



mental toil as it is worry that disturbs the mental poise. 

 It is not study, but fretting, that causes the student to 

 break down in his studies. Let young people have plenty 

 of nutritious food properly given, plenty of sound sleep, 

 enough suitable clothing, and a calm and wise oversight at 

 home, and they will rarely be injured by too much study. 



It is fretting about passing examinations, worrying about 

 promotions, and other bane- 

 ful influences, which have 

 become attached to our 

 educational system like 

 barnacles to a stately ship, 

 that may make the deli- 

 cate, sensitive child cross, 

 peevish, and sickly. 



309. Abuse of the Nerv- 

 ous System. Every tiny 

 cell of the nervous system 

 is busily at work doing its 

 allotted duty. Now, let a 

 person fret and worry day 

 after day over real or fancied 

 troubles, abuse his digest- 

 ive organs by too much or too little food, go without proper 

 sleep, smoke or chew tobacco in excess, try to prop up his 

 flagging energies with strong coffee or alcoholic liquors, and 

 the strain on the nervous system will make him, sooner or 

 later, a mental wreck. 



Like a spendthrift who spends his principal and per- 

 sists in calling it his income, so is a man who is indulging 

 in various forms of dissipation really exhausting the limited 

 amount of nervous force at his command. Unhealthful and 



FIG. 144. Dental Branches of One 

 of the Divisions of the Fifth Pair 

 of Cranial Nerves, supplying the 

 Upper Teeth. 



