330 



COORDINATION AND SENSATION 



Effects of Heat and Cold. Heat and cold both have 

 their effects upon the nervous system. Heat increases 

 the nervous irritability, while cold acts as a natural seda- 

 tive to the nerves. A nervous person is made more 

 nervous by an overheated atmosphere, but derives bene- 

 ficial effects from exposing the body freely to cold air and 

 water. The tonic cold bath (page 273), if taken with the 

 usual precautions, can be used to good advantage in di- 

 minishing nervousness. The taking of outdoor exercise 

 in cold weather is, for the same reason, an excellent 

 practice. 



Effect of Emotional States. We have already noted 

 the effect of certain emotional states upon the digestion 

 of the food (page 162). Emotional states are also known 

 to interfere with breathing and with the action of the 

 heart. Such effects are explained through the close re- 

 lation of the mind to the work of the nervous system in 

 general. While certain emotional states, such as fear, 

 anger, melancholia, and the impulse to worry, interfere 

 seriously with the normal action of the nervous system, 

 others, such as contentment, cheerfulness, and joy, are 

 decidedly beneficial in their effects. How important, then, 

 is the habit of suppressing the states that are harmful and 

 of cultivating those that are beneficial. From a hygienic, 

 as well as social, standpoint a cheerful, happy disposition 

 is worth all the effort necessary for its attainment. 



The Nervous Condition of Children should be a matter of 

 deep concern on the part of both parents and teachers. 

 In the home, as well as in the school, the child may be 

 " pushed " until the nervous system receives permanent 

 injury. Exhaustion of nerve cells is produced through 

 too many and too vivid impressions being made upon the 

 immature brain. The child should be protected from 



