344 FOOD AND DIGESTION 



TABLE OF THE PERCENTAGE COMPOSITION OF FOWLS' EGGS. 



Legumes are used by vegetarians as the principal source of the nitrogen of 

 the food. Those chiefly used are peas, beans, lentils, etc.; they contain a 

 nitrogenous substance called legumin, allied to albumin. Legumes contain 

 about 25.30 per cent, of this nitrogenous body and twice as much nitrogen 

 as wheat. Nuts also form a very nutritious article of diet. 



Carbohydrate Foods. Bread, made from ground grain obtained from the 

 various so-called cereals, viz., wheat, rye, maize, barley, rice, oats, etc., is 

 the direct form in which the carbohydrate is supplied in an ordinary diet. 

 It contains starch, dextrin, and a little sugar. It also contains gluten, com- 

 posed of vegetable proteins, and a small amount of fat. 



TABLE OF PERCENTAGE COMPOSITION OF BREAD AND FLOUR. 



Various articles besides bread are made from flour, e. g., spaghetti, maca- 

 roni, etc. Dextrin and a small amount of dextrose are present in bread, 

 particularly in the crust. 



Vegetables, especially potatoes. They contain starch and sugar. In 

 cabbage, turnips, etc., the salts of potassium are abundant. 



Fruits contain sugar and organic acids, tartaric, malic, citric, and others. 



Sugar, chiefly saccharose, used pure or in various sweetmeats. 



Oils and Fats. The substances supplying the oils and fats of the food 

 are chiefly butter, bacon and lard, suet (beef and mutton fat), and vegetable 

 oils. These contain the fats olein, stearin, and palmitin. Butter contains 

 some tributyrin, while vegetable oils, as a rule, contain no stearin. 



Mineral or Inorganic Foods. The salts of the food. Nearly all the 

 substances in the preceding classes contain a greater or less amount of the 

 salts required in food. Green vegetables and fruit contain certain salts, 

 chiefly potassium. Sodium chloride is an essential food; it is contained in 



