420 IDEAL HOME LIFE
meat of fowls are the most readily digested and assimilated. Pork, the dark meat of fowls, game, and fish are less readily digested. Soups, when prepared from both fat and lean meats, are naturally less easily digested than those which are made from lean meat alone.
The cereals, oats, rye, barley, corn, etc., have a very important value. They consist largely of starchy material (hydrocarbons), but also have a certain percentage—varying in different specimens and different grains—of vegetable albumen, so that they have the possibility of forming the principal portion of the nutriment of large portions of the human race.
Rice and potatoes consist very largely of starch. The former is the principal article of diet of the majority of human beings, and its results in vital force, especially among the myriads in China, India, and the tropics, are indeed remarkable. Probably climate and race act as very important factors in determining these results, however. In Ireland and in South American countries in which the potato is indigenous, this substance, though almost exclusively starch, constitutes the bulk of the food. The results, especially in Ireland, often show the disadvantages of so exclusive a diet. Peas and beans contain a large portion of starch, but they also contain considerable vegetable albumen, which gives them great value as food. The nutritive value of some of the fruits and nuts (for example, cocoanuts and bananas), though they consist mostly of starch and sugar, is very great. Many other fruits and vegetables consist very largely of water with some starch, fat, sugar, and very palatable vegetable acids. They give variety to the diet, are often mildly laxative to the bowels, and therefore play a very prominent part in the mixed diet. The fruit of the olive tree is a conspicuous example of the great utility of a vegetable product.
Tea, Coffee, and Their Substitutes
The value of tea and coffee, so far as their active principle (theine, caffeine) is concerned, is alike for each, since the molecular construction of each is the same. Tea contains tannic acid, which gives it its astringent property, and explains the