A comparison of its chemical composition with that of wheat or corn will show that it is by no means equal to them in nutritive value. It is obviously unfitted to sustain life alone, and hence in rice-eating countries it is mixed with fat or other foods supplying principles in which it is deficient.

Corn has the following composition (Letheby, Smith) :

Water...................................................... 14·0

Nitrogenous matter (albumen).................................. 11·0

Starch___................................................. 64·7

Sugar....................................................... 0·4

Fat......................................................... 8·1

Salts....................................................... 1·7

It is not so readily digested as starch, requiring about three hours. Corn, when green, is prepared for the table by boiling, and is eaten with salt and butter, or milk. If young and tender, and sufficiently cooked, it is a digestible and nutritious food; but, if the grain is too mature, it resists the action of the intestinal juices, and passes unchanged.

The mature grain, deprived of the heart and husk, is known as hominy. Thus prepared and thoroughly boiled it is an esteemed article of diet, ranking in nutritive value a little above boiled starch. Mush is boiled corn-meal, which may be eaten with milk, and is sometimes fried, but in that form is highly objectionable. Corn-meal is also eaten in the form of bread and cakes. These various preparations of corn are liable to cause intestinal disorders, and hence are improper in cases of irritable mucous membrane, and in diarrhoeal diseases. For this reason corn-bread is sometimes prescribed in cases of constipation dependent on diminished secretion of the intestinal mucous membrane, and torpor of the muscular layer of the bowel. The starch of corn is not unfrequently prepared for invalids in the form of blanc-mange.

Oatmeal corresponds in physical qualities and composition to corn-meal. Its proximate composition, according to Smith, is as follows:

Water......................................................  15·0

Nitrogenous matter..........................................   12·6

Starch......................................................  58·4

Sugar......................................................    5·4

Fat.........................................................    5·6

Salts........................................................    3·0

It is not at all generally used as an article of diet in this country. It is prescribed in the form of gruel as a delicate food. Boiled for a long time, the oatmeal swells up and thickens, forming a blancmange, which may be eaten with milk, or butter, or cream, and sugar and aromatics.

Buckwheat flour is largely consumed in this country, chiefly in the form of breakfast-cakes. As it contains a relatively small proportion of starch, and considerably more fat and salts than wheat flour, it can be eaten by diabetics in the form of light bread, and is said to be preferable to any gluten preparation.

The Potato, next to wheat, is the most important food derived from the vegetable kingdom. Its composition is affected by its source and variety, and by the soil in which it is grown. The specific gravity of the potato affords an index of its nutritive value, for, the heavier, the greater the quantity of starch it contains. For the sick, watery potatoes are unsuitable. "When cooked, the tuber should be mealy and dry. The following is the composition of the potato:

Water.....................................................    75·0

Nitrogenous matter...........................................    2·l

Starch......................................................   188

Sugar......................................................    3·2

Fat........................................................    0·2

Salts........................................................    0·7

According to some authorities, the potato contains free citric acid. The salts are rich in potash. According to Letheby, the composition of the sweet-potato is nearly that of the white, the chief difference being the proportion of sugar, which is three times greater than in the latter.

Starch, Sago, Arrowroot, and Tapioca, differ from the preceding vegetable foods in that they contain no nitrogen. They are digested in from one to two hours. They are largely used in the preparation of diets for the sick, but are insufficient in themselves to maintain for any considerable period the vital functions. Hence they are prepared and eaten with sugar, milk, cream, butter, and aromatics.

Turnips, Parsnips, Carrots, Onions, Asparagus, Beets, Cauliflower, Cabbages, and Celery, are but rarely prescribed for the sick, but enter into certain special plans of diet. According to Smith, the following represents the composition of

Beets differ from the above chiefly in the quantity of sugar. The following is the analysis of Payen:

Salts and pecten........................... 3·7

All of the members of this group are deficient in nutritive value, and are besides slow and difficult of digestion, requiring from three to five hours for complete solution.

Ripe fruits, as grapes, apples, pears, peaches, oranges, lemons, etc., possess but little nutritive value, as they contain only about 10 to 15 per cent of solid matters. In composition they are represented by sugar, free acid (tartaric, citric, etc.), nitrogenous matters, and salts. They differ, of course, in the peculiar flavoring matters which give to each fruit its special taste. Dried fruits, as dates, figs, and raisins, are relatively much more nutritive, because they contain a larger percentage of sugar. Under the head of dietetic management of diseased states, some further remarks will be made on the use of the fresh and dried fruits.