THE DIGESTIVE APPARATUS AND NUTRITION 241 



the microorganisms mentioned above, and the mouth 

 should be well rinsed with a solution of the same. 



348. It is a mistake to suppose that a child should be 

 supplied with soft, pulpy food. Just as soon as the first 

 set of teeth are in place, he should have a fare which will 

 require vigorous mastication. He should not be allowed 

 to reject bread crusts and eat only the soft crumb, nor 

 should his bread be always soaked in milk or gravy. 

 Plenty of hard " chewing " is not only good for the teeth; 

 it also promotes the flow of the saliva necessary to diges- 

 tion and aids in the development of the jaws, and so 

 helps to provide room for the second set. 



The teeth should be under the care of a competent den- 

 tist, who by yearly or seiniy early examination and repair 

 will be able to forestall and prevent the inroads of decay. 



349. While a due action of the mechanism of mastica- 

 tion is to be sought, that overactivity which results from 

 the habit of chewing tobacco or gum is to be avoided. While 

 a sense of propriety and good taste should alone be suffi- 

 cient to condemn such a habit, there are hygienic rea- 

 sons for its avoidance. The constant stimulation of the 

 salivary glands leads finally to their weakness and defect- 

 ive action, thus laying a foundation for general derange- 

 ment of digestion. Many dentists also regard it as directly 

 injurious to the teeth. 



350. Food is not ready for the action of the gastric 

 juice until it has been finely divided by the teeth and all 

 portions well moistened with saliva. Slow and thorough 

 mastication is therefore necessary to perfect digestion. 

 Too rapid eating not only shows bad manners, but also is 

 exceedingly bad for the health. 



351. The temperature of our food should not be so hot 

 as to stimulate unduly the glands of the mucous mem- 



