124 THE HUMAN BODY. 



Cooking. When meat is cooked most of its connective 

 tissue is turned into gelatin, and the whole mass becomes 

 softer and more readily broken up by the teeth. In boil- 

 ing meat it is a good plan to put it first into boiling water 

 which coagulates its surface layer of albumen, and this then 

 keeps in flavoring and other matters which would otherwise 

 pass out into the water. After the first few minutes the 

 cooking should be continued at a lower temperature; meat 

 boiled too fast is hard, tough, and stringy. In roasting or 

 baking meat, the same plan is advisable. Put it close to 

 the fire or in a hot oven for a short time, and then com- 

 plete the cooking more slowly at a lower temperature. 



The cooking of vegetable foods is of considerable impor- 

 tance. Starch is the chief nutrient matter in most of them, 

 and raw starch is much less easily digested than cooked. 

 When starch is roasted it is turned into a substance known 

 as soluble starch, which is easily dissolved by the digestive 

 liquids, so there is a scientific foundation for the common 

 belief that the crust of a loaf is more digestible than the 

 crumb, and toast than fresh bread. 



The Oxidizable Matters required daily by the Body. 

 The necessary quantity of daily food depends upon that of 

 the material used by the body and passed out from it in each 

 twenty-four hours; this varies both in kind and amount 

 with the work done and the organs most used. In children 

 a certain excess is required to furnish material for growth. 



What happens when meat is cooked ? 



Why does a good cook first put meat that she is to boil into very 

 hot water? Why should the boiling be completed at a lower temper- 

 ature? How should meat be baked? 



Why is it important to cook most vegetable foods ? Why is toast 

 more easily digested than fresh bread? 



What determines the necessary amount of daily food? How does 

 it vary? Why do children require more in proportion to their size 

 than adults? 



