204 SOME NERVOUS DISEASES. 



keeps in action the lungs, and skin, and kidneys to 

 purify the blood; it makes the eye see and the ear hear; 

 and through it we think, and hope, and love. To injure 

 the nervous system by too much work, too little sleep, 

 or over-indulgence in tobacco, alcohol, or any other sub- 

 stance which affects it, is to weaken every function of 

 the body and the mind. 



No doubt many persons have attained intellectual 

 eminence and led happy and useful lives in spite of 

 bodily feebleness. Unusual strength of will has enabled 

 them to overcome the odds against them. But we 

 should remember that body and mind are so united 

 that any disease of one affects the other, and she aid 

 guide our conduct accordingly. 



2. Some Disorders of the Nervous .System. Unhappily 

 most children have seen cases of " St. Vitus' Dance" It 

 is a twitching of the muscles, sometimes only those of 

 the face, sometimes those of the limbs and body gener- 

 ally. It comes from weakening of the control of the 

 nervous system over the muscles, so that occasionally 

 some muscle relaxes. This enables the opposing muscle 

 to give a jerk and pull the organ, it may be the eyelid, 

 the mouth, the arm, or the leg, out of place. Sometimes 

 these jerkings are so violent as to seriously injure the 

 organs. 



Fit is a name given to several disorders attended with 

 loss of consciousness. A fainting fit is due to temporary 

 weakness of the heart; it pumps so little blood around 

 that the cerebrum does not get enough nourishment to 



What are the consequences of injuring the nervous system ? What 

 have some persons of feeble body accomplished ? How ? What 

 should we remember ? 

 2. What is St. Vims' dance ? To what due ? To what is a fainting 



