The soy beans have long been an important article of diet among the Chinese and Japanese peoples, and have been grown within recent years somewhat extensively in the United States. The dietary properties of this seed have been studied in several laboratories (15). The results show that this seed belongs in the same class with peas and navy beans for it contains proteins which are adequate when fed at a plane corresponding to 17 per cent or more of the diet, and can support growth when they form the sole protein supply.

When soy beans are supplemented with potassium and calcium salts and butter fat (fat-soluble A) the nutrition of rats was markedly improved as shown by better growth, larger litters, better developed young and lower mortality of the latter.