82 THE HOUSE I LIVE IN. 



wear out much sooner for picking the teeth, 

 as many do, with pins and needles. These 

 things are too hard, even for the hard enamel, 

 and are apt to crumble it off. So is the 

 wretched practice of cracking nuts with the 

 teeth, or indeed the biting of any substance 

 harder than the crust of good dry bread. If 

 used to bite nothing harder than that, and if 

 not injured in .any other way for there are a 

 thousand ways of injuring the teeth they may 

 perhaps last all our lives. But if the enamel 

 once gets broken away, so that the air and 

 other substances come to the softer bone under 

 it, the tooth soon becomes hollow, or decays. 

 Like any other part of this wonderful frame 

 which God has given us, the teeth will, how- 

 ever, last the longer for being moderately used. 



Those kinds of food and drink which injure 

 the stomach, injure also the teeth, and cause 

 the enamel to become soft and break away. 

 Why this is so, is a question which it would 

 take too long to answer here ; but you may 

 believe the fact. In another place, I shall 

 probably say more on this subject. 



One thing, however, now. You should 

 keep your teeth clean. After eating anything, 



