FOOD 197 



small amount of ashes remains, showing the mineral 

 matter. Cereals contain all of the four classes of food. 



341. Sources of Food. All parts of a plant may furnish 

 food: the seed, as the various grains, nuts, and fruits ; leaves, 

 as lettuce, cabbage, dandelion; roots and tubers, as pota- 

 toes, beets, turnips, tapioca (root of cassava) ; stem, as sago 

 (pith of sago palm) ; saps, as sugars (of cane, beets, and 

 maple tree); honey; and oils (from peanuts, cottonseed, 

 olives, pecans and other nuts). 



342. Sources of proteid : albumen, in white of egg ; 

 gluten, the sticky or gluey part of grain ; casein, in cheese 

 and the curd of milk; fibrin, in the blood of animals; 

 myosin, the basis of lean meat ; gelatin, obtained from 

 bones and ligaments by boiling ; vegetable casein, in beans, 

 peas, and nuts. 



343. Sources of fats and oils : cream of milk, yolk of 

 egg, oil of nuts, olives, cottonseed, cocoanut, and fat of 

 meat. 



344. Sources of starch : corn, wheat, rice, oats, and other 

 grains, potatoes, cassava, arrowroot, sago (in this country 

 the last two are usually potato starch sold under those 

 names), beans, peas. 



345. Sources of sugar : sugar cane, sorghum, dates, 

 honey (almost pure sugar), bananas (20 per cent), grapes, 

 fruits, beets, maple trees. 



346. Study the table showing composition of foods 

 ( 434). Which grain has the least proteid ? Which has 

 the most ? the most starch ? the least ? the most fat ? the 

 least ? What vegetable foods are rich in proteid ? In oil ? 

 Which food has least nutrition (contains most water and 

 cellulose) ? Which has most nutrition ? 



347. Experience has shown that the diet best suited for 

 the body must contain, besides water, one part of nitrog- 

 enous food to four parts of non-nitrogenous food. Which 

 of the foods in the table approximate this proportion ? 



