Accessory Factors, or “Vitamines,” in Diet

Abstract

IT was known to Captain Cook that fresh food, especially green vegetables, contained something which was absent from the preserved food used by him in his voyages, but was necessary to maintain health. Stepp showed, a few years ago, that bread and milk, if extracted with alcohol, did not suffice for the growth of rats, but that addition of the residue from the alcohol extract restored the adequacy of the diet. Hopkins then found that rats are unable to grow on a diet, otherwise complete, composed only of pure protein, fat, carbohydrate and salts, although this diet can be rendered perfectly adequate by the addition of a minute amount of milk. Further research by Osborne and Mendel and others in the United States confirmed these results.