DIGESTION DIAGRAM 1. 15 



another artery into all the body. There it loses its vermillion 

 colour, and returns to the heart by a large vein to be sent back 

 to the lungs, and so on. This is circulation. 



DIGESTION. Man must eat and drink in order to live. All 

 the solids and liquids which he employs for this purpose are 

 called food. But they are not all equally nourishing. It is 

 generally necessary that a diet should be a little varied to be 

 wholesome ; but it is a mistake to suppose that one cannot live 

 without such "and such a food. In towns, one is too apt to 

 believe that meat is indispensable to health. It may very 

 advantageously be replaced by milk or cheese. Nor is bread 

 indispensable, and some people eat hardly any. Habit has 

 much to do with all this. Certainly, we may be a little in- 

 convenienced, or even made ill, if we suddenly discontinue a 

 diet to which we have long been accustomed ; but we generally 

 soon become accustomed, especially in youth, to a very different 

 diet to what we had formerly been used'to. 



The most nourishing foods, and those which are consequently 

 styled nutritious, are meats and vegetables. But not to grow 

 tired of these, we generally add small quantities of other 

 substances to them, which are not so nutritious, but which, 

 nevertheless, greatly assist digestion, such as salt and pepper. 

 These foods, of a special kind, have been called condiments. 



The best and most wholesome of all beverages is undoubtedly 

 spring water. Nevertheless, custom has almost everywhere 

 abandoned it for the use of fermented liquors, either made of 

 grapes, apples, or barley. Beer, cider, and especially wine, 

 are excellent drinks, so long as they are not used to excess. 

 But we should always be very cautious in the use of brandy, 

 rum, and all alcoholic liquors. They have at first the serious 

 inconvenience of causing drunkenness, in which state a man 

 no longer knows what he is doing ; but repeated drunkenness 

 leads to much more serious consequences in time ; and men 

 who have fallen into this habit grow old before old age, their 

 speech is confused, their hands shake, and they often end their 



