228 OUR BODIES AND HOW WE LIVE 



306. The Health of the Nervous System. The health of 

 every organ of the body is dependent upon the welfare 

 of the nervous system. 



If a tiny blood vessel in the brain is broken and forms 

 a little clot as large as a pea, a paralysis of one side may 

 be produced by its pressure on the delicate brain tissue. 

 An overloaded stomach may make the brain dull and 

 stupid for some time. Indigestion may make one cross, 

 morose, and unhappy. The long loss of sleep may cause 

 exquisite suffering. 



A slight blow on the head may instantly rob a man of 

 consciousness. On the other hand, severe accidents to the 

 brain may not produce serious results. By breathing in such 

 poisons as ether or carbonic acid gas, the blood is so altered 

 that the brain ceases to act and consciousness vanishes. 



307. Brain Power increased by Education. Like any 

 other organ, the brain may be strengthened and increased 

 in its power by education. Impressions made upon the 

 mind in early life are more readily received and more com- 

 pletely retained than those which are made when the growth 

 of the brain is far advanced. For this reason, education 

 should be begun early in life ; and educational influences 

 brought to bear at that time are most effective in shaping 

 mental growth. It is an object for which most parents are 

 willing to work hard and to exercise much self-denial. 



308. Worry and not Mental Work overtaxes the Nervous 

 System. Just as the stomach may be overworked and fail 

 after a time to digest food properly, and as muscles are 

 exhausted by overexertion, so may the nervous system, 

 especially the brain, be overtaxed. 



Mental work is rarely hurtful to a healthy person who 

 takes good care of himself. It is not so much severe 



