x FOOD AND FOOD-PLANTS 117 



chemist gives these three special names, and there 

 are many conveniences in learning these three names, 

 though two of them are never used in daily life. 



The first, and in some ways the most important, 

 is proteid. Many people would use instead of this 

 name the everyday word meat ; but this is not exact, 

 for though meat consists of proteid yet we have 

 to remember that bread, for instance, and other 

 vegetable foods also contain proteid. No animal 

 can live without proteid, but we know that the 

 cow does not eat meat she gets her proteid in the 

 grass which she eats. But as, bulk for bulk, there 

 is always less proteid in plants than in animal 

 matter, the cow must eat far more proportionately 

 than the cat, which eats meat. In the same way 

 with man, the people who eat meat do riot need to 

 take so much bulk of food as the people who live 

 on vegetable food only. 



The second substance which we need in our 

 food is what is called carbohydrate, which is simply 

 a convenient word to include both starch and 

 sugar. We need far more starch or sugar than 

 proteid, and the bulk of our food is, or should be, 

 carbohydrate. Bread, for instance, is largely made 

 of starch. 



Finally, we need an amount of fat, which varies 

 with the climate and the season, and can be got 

 either from plants or animals. 



