HYGIENE OF THE NERVOUS SYSTEM 327 



incd and glasses fitted by a competent oculist. 1 The 

 nervous energy should be carefully economized and the 

 habit of self-control diligently cultivated. Special exer- 

 cises that have for their purpose the equalizing of the cir- 

 culation and the strengthening of the blood vessels of the 

 neck and the brain also have beneficial effects. 



Nervous Overstrain. Both mental and physical over- 

 work tends to weaken the nervous system and to produce 

 nervousness. Where hard mental work is long continued, 

 or where it is carried on under excitement, a tense nervous 

 condition is developed which is decidedly weakening in its 

 effects. The causes which lead to such a condition, and 

 in fact overwork of all kinds, should if possible be avoided. 

 Where this is not possible, and in many cases it is not, the 

 period of overwork should be followed by one of rest, 

 recreation, and plenty of sleep. To the overworked in 

 body or in mind, nothing is more important from a hygi- 

 enic, as well as moral, standpoint, than the right use of the 

 one rest day in seven. The best interests of our modern 

 civilization require that the Sabbath -be kept as a quiet, 

 rest-giving day. 



Disturbed Circulation of the Brain. Nervousness not in- 

 frequently is accompanied by an increase in the circulation 

 of the brain and disappears when this condition is relieved. 

 Though mental work and excitement tend naturally to in- 

 crease the circulation in the brain, this should subside with 

 rest and relief from excitement. When there is a tendency 



1 Any part of the body which is overworked or which works at a disadvantage 

 tends to disturb, more or less, the entire nervous system and to produce nervous- 

 ness. Especially is this true of such delicate and highly sensitive structures as the 

 eyes. If the eyes do not focus properly or if the muscles that move the eyeballs 

 are out of their natural adjustment, extra work is thrown upon these delicate parts. 

 One of the first and sometimes the only indication of eye strain is that of some dis- 

 turbance of the nervous system. For this reason it is important to carefully test 

 the eyes in determining the cause of nervousness (page 385). 



