THE CHEMISTRY OF FOOD 87 



these various principles, the necessity and value of which are 

 now explained. (Read Notes 12 and 13.) 



12. Variety in Diet and in its Preparation Beneficial. "Every 

 dietary should contain fresh vegetables. It is further necessary that cer- 

 tain articles belonging to the same class be varied from day to day, other- 

 wise the appetite cloys. Beef should alternate with mutton, for example ; 

 or variety should be secured by different modes of cooking the same 

 article. Indeed, it is not too much to say that the art of cookery is a 

 matter of national importance, not only because it renders food palatable, 

 but because the more it is studied and practised the greater is the 

 economy which may be effected. It is chiefly in this relation, that bever- 

 ages, condiments, etc., become such valuable dietetic adjuncts." Wil- 

 son's Hand-book of Hygiene. 



13. Some Experiments as to Food. " Magendie made numerous 

 experiments on the inferior animals to test the value of different forms of 

 nutriment. He showed that a diet exclusively composed of starch and 

 sugar would not support life. So, too, dogs confined to white bread and 

 water died with all the symptoms of starvation ; but on the military 

 brown-bread animals lived pretty well, as this article contains a greater 

 variety of the alimentary principles. Other experiments have given an 

 account of geese limited to some one substance. All of them died the 

 animal fed upon gum, on the sixteenth day ; that fed with sugar, on the 

 twenty-first day ; one fed with starch, on the twenty-fourth day ; and one 

 fed with white of egg, on the twenty-sixth day. In 1769, before these 

 experiments were performed, Dr. Stark, a young English physiologist, 

 fell a victim at an early age to ill-judged experiments on himself as to the 

 effects of different foods. He lived for forty-four days on bread and 

 water, for twenty-nine days on bread, sugar, and water, and for twenty- 

 four days on bread, water, and olive oil ; until finally, his constitution 

 became broken, and he died from the effects of his experiments." 

 Flint's Physiology. 



TOPICAL OUTLINE 



C Albumen white of egg. 

 Caseine miljp and cheese. 



(Nitrogenous. . j Fibrin blood. 

 \ Myosin muscle. 

 I Gelatin -bone. 



I Non-nitrogenous Fats and sugar. 



FOODS 



VEGETABLE 



I MINERAL . | phosphate, etc. 



Nitrogenous. . { ? luten ~real grains. 



[ Legumen oeans, etc. 



f Starch all parts of plants. 

 Non-nitrogenous \ Sugars -all parts of plants. 



j Gums all parts of plants. 



I Oils fruits. 

 Water, common salt, calcium carbonate, calcium 



