Abstract
Summary (1) It is shown that yeast G (cultured, primary dried yeast) and yeast K (debittered, dried brewers yeast), which do not induce liver degeneration, exert a strong protective influence when added to diets causing the disease. It has been demonstrated by fractionation experiments that this effect is not due to vit. E or cystine, but due to a third unidentified factor, designated factor 3, which has been concentrated from yeast K. (2) The presence of factor 3 explains why dietary necrotic liver degeneration cannot be produced with American yeasts G and K. Factor 3 is water soluble, stable against acid hydrolysis, and is not identical with any one of the presently well-known vitamins.