154 GOOD HEALTH 



1. What to eat. 



2. When to eat. 



3. How to eat. 



4. How much to eat. 



First of all, however, he needs to know a little about 

 the part of the body that uses the food. He must bear in 

 mind the important fact that it is a long tube, beginning 

 with the mouth, enlarging as a stomach, then becoming a 

 tube again. Parts of it are straight and parts are twisted ; 

 parts are large and parts are small ; but every mouthful 

 of food we swallow takes the same road through it 



The next time you eat, notice just what happens. 

 You might try an experiment first: wipe your tongue 

 perfectly dry and put a lump of sugar on it. You will 

 be surprised to find that you cannot taste the sugar with 

 a dry tongue. This is true of other kinds of food, for the 

 fact is it is the saliva in our mouths that helps us taste 

 anything. Yet the saliva has even more important work 

 to do. 



Put a piece of bread into your mouth. Perhaps you 

 want to swallow it at once, but it is too hard and dry ; so 

 you crush it between your teeth and bite it into smaller 

 and smaller pieces ; your tongue turns it over and rolls 

 it around, while you keep on chewing, and all the while 

 the bread is getting damp and soft. 



That is the main use of saliva : it gets the food ready 

 for swallowing. Perhaps the wonder is where all the 



