vast range of materials which civilized man has at his command for the purpose of food: these few preliminary remarks on the chemical constituents of food having been intended to aid in appreciating the value of different kinds.
Commencing with the vegetable kingdom, from which our early progenitors, probably during long ages, drew all their sustenance, the cereals, or cultivated grasses, come first, as containing all the elements necessary to life, and being therefore most largely consumed. Wheat and its congeners, which rank highest in quality, had been distinguished in the form of bread, as "the staff of life," long before the physiological demonstration of the fact had been attained. Wheat, oats, rye, and barley, maize and rice, are the chief members of this group; wheat containing the most nitrogenous or flesh-forming material, besides abundance of starch, a moderate amount of fat, together with sufficient saline and mineral elements. Rice, on the other hand, contains very little nitrogen, fat, and mineral constituents, but starch in great abundance; while maize, with a fair supply of nitrogenous and starchy matter, contains the most fat or heat-producing material of the whole group. As derived from wheat must be named the valuable aliments, macaroni and all the Italian pastes. Derived from barley is malt-saccharine, parent of the large family of fermented liquors known as beer. And from various other grains are obtained, by fermentation and distillation, several forms of ardent spirit. Vinegar, best when produced from the grape, is also largely made from grain.
The legumes, such as beans, lentils, and peas, form an aliment of great value, containing more nitrogen even than the cereals, but with fat in very small proportion, while starchy matter and the mineral elements abound in both groups.
The tuber finds its type in the potato, which contains much starch, little nitrogen, and almost no fat; in the yam also. The roots may be illustrated by the beet, carrot, parsnip, and turnip, all containing little nitrogen, but much sugar, and water in large proportion. Derived from roots and stems of foreign growth, we have arrowroot, tapioca, and sago, all starches and destitute of nitrogen. Fatty matter is abundantly found in the olive, which supplies a large part of the world with an important article of food. The almond and other seeds are also fruitful sources of oil.
Under the term "green vegetables," a few leading plants may be enumerated as types of the vast natural supplies which everywhere, exist: The entire cabbage tribe in great variety; lettuces, endive, and cresses; spinach, seakale, asparagus, celery, onions, artichokes, and tomato, all valuable not so much for nutritive property, which is inconsiderable, as for admixture with other food chiefly on account of salts which they contain, and for their appetizing aroma and varied flavors. Thus condiments are useful, as the sweet and aromatic spices, the peppers, mustard, and the various potherbs, so essential to an agreeable
