CHAPTER XXIV 



HYGIENE OF THE SENSE ORGANS 



Questions. 1. Why do so many people have to wear glasses today? 

 2. Why do people living in cities have greater need for glasses than those 

 living in the country? 3. W^hy are the special sense organs in greater 

 need of protection than other organs of the body ? 4. What concern is it 

 of the taxpayer's if some children do have defective eyesight or hearing ? 



192. Hygiene of the skin. The end organs of touch, heat, 

 cold, and pain form an intimate part of the skin. Their health 

 depends upon the general tone of the skin, the circulation of the 

 blood near the surface, and the condition of the blood. What- 

 ever keeps the body as a whole and the skin in good condition 

 will serve for these organs also (see Chapter XX). We prob- 

 ably cannot increase the sensitiveness of our organs by anything 

 we do, although it is possible to dull them. The extreme sensi- 

 tiveness in the finger tips of a blind person probably results 

 from learning to interpret impressions received and not from 

 an increase in the delicacy of the nerve endings, but the conges- 

 tion of the skin capillaries from using alcohol may result in 

 false impressions regarding the temperature of the surrounding 

 air ; one may feel warm when the air is really cold. 



193. Taste. The tongue, considered as a sense organ, needs 

 no special attention to preserve its health. Disagreeable tastes 

 in the mouth may arise from disturbances of digestion, or from 

 the presence of decaying particles of food between the teeth. 

 The sensitivity of the tongue may be impaired by excessive use 

 of spices and condiments and by excessive smoking. 



194. The nose. The chief source of disturbance to the sense 

 of smell is a cold in the nose, which results in the accumulation 

 of mucus in the nasal passages and so in an obstruction of the 

 sensory surfaces. An additional danger of colds in the nasal 



235 



