18 THE WONDERFUL HOUSE THAT JACK HAS 



The first one of these dissolving stations is in the 

 mouth, and the fluid secreted there is known as saliva. 

 The glands that secrete it open into various parts 

 of the mouth and are called salivary glands. Saliva 

 changes some of the starchy food we eat to sugar. 

 It does not digest proteids or fats, or completely digest 

 starch. It does, however, change starch to a form 

 in which it is much more easily digested by the fluids 

 in the intestines. On this account, it is especially 

 necessary that bread, potatoes, cake, and all starchy 

 foods should be well masticated. Proteids and fats, 

 too, when thoroughly chewed before being swallowed, 

 are much more readily acted upon by the digestive 

 juices with which they come in contact later. Saliva 

 is also said to stimulate the glands in the stomach 

 to greater action. 



When we place bread and similar solid foods in 

 water, they soften and separate into small pieces. 

 Warm water causes such separation more rapidly 

 than cold. If certain acids or alkalies are added, 

 the change in form takes place more speedily and 

 completely. The finer the food is cut before being 

 placed in the water, and the more the solution is mixed, 

 the more quickly it is dissolved. 



What can be learned from this simple experi- 

 ment ? Two most important things, if we are to build 

 strong bodies. The first is to keep the inside of the 

 mouth at its normal temperature while eating; the 

 second, to chew our food so thoroughly that it will 



