This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
Buckwheat, or blackwheat as it is sometimes called, is indigenous to temperate climates, and in some parts of the world, notably in Russia, Siberia, and Brittany, it constitutes a staple of diet, but in the United States it is the least imporant of the cereals, and is used rather as a luxury for making griddle cakes. The buckwheat produced in the United States is mainly raised in New York, Pennsylvania, and some of the New England States. Buckwheat bread is nutritious, but it crumbles and does not keep well.
Soya bread is made from an oily pea which grows in China and Japan, and is used sometimes by diabetics, for it contains over one third part of gluten and but 1.17 per cent of glucose.
Millet and sorghum are grown in the warmest parts of Asia and Africa, and to some extent in southern Europe. In Russia millet is sold as a white meal. White sorghum, which is a grass or cane, is converted into flour called doura, and in Africa, mingled with barley, it is distilled into beer. A fine quality of alcohol may be made from it. In the United States it is mainly grown for molasses and sirup; sugar is also made from it. Bread made from either millet or sorghum meal is fairly palatable and nutritious when warm, but when it becomes cold it grows dark and crumbles. The grains are hulled like barley and are ground into flour, which is either eaten pure or mixed with bread. Millet is a grass raised largely in India, China, Egypt, along the west coast of Africa, in Italy, Spain, and Portugal. There are many sub-varieties. It contains, on an average, over 7 per cent of fat, nearly 10 per cent each of proteid and dextrin, 60 per cent of starch, and 2 of sugar (Parkes).