HYGIENE OF THE NERVOUS SYSTEM 321 



Proper habits of study should be acquired. One should 

 learn to bring all his mental force to bear upon the work 

 in hand to concentrate Ms thoughts, as we say ; that is, 

 to hold his attention firmly upon the subject before him, 

 and not dawdle over his book, letting his thoughts run 

 from one topic to another according to chance sugges 

 tions, coming back only now and then to his work. Such 

 practices weaken the brain and unfit it for effective labor. 

 Severe, intense mental effort for a short time should be 

 the rule, and then relaxation or complete change in the 

 form of labor. But bad mental habits, abuse of the 

 digestive organs, and the breathing of impure air are not 

 the only causes of injury to brain and nerves. A life 

 of overexcitement, which keeps the nerves continually 

 a quiver in response to incessant stimulation, has shattered 

 the nervous system of many a girl or young woman. Our 

 American customs leave to the young too little space 

 for the quiet, regular, uneventful living which promotes 

 health of mind and body, strengthens for future useful- 

 ness, and stores energy for the severe and sudden emer- 

 gencies of mature life. If a girl breaks down in health 

 during her school years, her teachers are usually blamed 

 as exacting too much brain work, whereas the mischief is, 

 in fact, far oftener due to unhygienic habits of life, to too 

 rich or otherwise unsuitable food, to lack of air and exer- 

 cise, and, especially, to too much social indulgence, along 

 with late hours which interfere with regular and abundant 

 sleep and use up the nervous force which should be given 

 to study or stored for the future. 



468. Habit as connected with Nervous Action. Something 

 was said upon this subject when reflex nervous action was 

 considered, but its importance is so great that it should 

 be further dwelt upon. 



