Barley
The nutritive elements of barley are similar to those of wheat and rye. It contains less cellulose fiber, and therefore a larger per cent of digestible nutrients than any one of the cereal group except rice. It has never become popular as a bread-making grain because—
1 The nitrogenous or gluten substances are not tenacious enough to make the conventional "raised" bread
2 The flour is dark in color
3 The grain is so hard and "flinty" that it is very difficult to mill it down to the required fineness
For these reasons barley has been greatly neglected as a food commodity. From a chemical standpoint it deserves a much higher place in our dietaries than it has hitherto been given.
Oats
The composition of oats varies somewhat from that of wheat, rye and barley. They contain a larger proportion of both fat and proteids, and form a desirable food if correctly prepared. The objection to oats as an article of diet is the hasty manner in which they are usually prepared, which converts them into a gummy mass of gelatinized starch, entangled with the peculiar gummy proteid of the oat grain. Thus prepared the oat is a most prolific source of disturbed digestion.
Corn
Corn is the cheapest material capable of nourishing the human body that is produced in the temperate zone. It is less digestible, and more deficient in the salts than the group of grains thus far mentioned. It is very wholesome, however, but in no way superior to other grains. In the future corn will probably play an increasing part in the problem of feeding the world, as a cheap source of carbohydrates, and for the purpose of manufacturing glucose.
Rice