74 MANUAL OF NATURS STUDY. 



light. Long-continued looking at one object. 

 Looking at bright objects like the reflection .of light 

 from a mirror, or from white wall or paper. Effect 

 of trying to read or write with insufficient light, 

 e. g. — in dusk of the evening. 



Near sightedness and cross-eyes should receive 

 proper attention. 



2. The care of ears. Next to the eyes, the ears 

 are most important, and should receive our atten- 

 tion. The ear should be taught in its three parts, 

 external^ middle and internal. The outer ear gath- 

 ers the sound waves and therefore should be clean. 

 The wax is of use in keeping out insects and pro- 

 tecting the internal ear from exposure to cold air. 

 While it should not be removed entirely, yet it 

 should not be allowed to harden at the opening and 

 thus clog up the passage way, or to create too much 

 pressure upon the tympanum. 



Children should be cautioned against the practise 

 of screaming or whistling in another's ear. Such 

 practise is dangerous to the ear. Catarrh causes 

 deafness, hence care should be taken to prevent 

 taking cold. Do not pick the ear with a pin or 

 other hard substance. Avoid the use of tobacco, as 

 that will produce inflammation in the ear, and dry 

 the tympanum and thereby cause confusion of 

 sounds. 



