VITAMIN G (Bo) 125 



violet irradiation can be relied upon to destroy vitamin G (Bg). See 

 also Chick and Roscoe (1929). 



Williams and Waterman (1927, 1928) postulated the tripartite 

 nature of "vitamin B" in reporting the results of a quantitative com- 

 parison of the effects upon adult pigeons and young rats of various 

 yeast preparations used as supplements to the Sherman-Spohn water- 

 soluble-vitamin-free diet. The yeast preparations included (1) an 

 aqueous extract of brewers' yeast, (2) fuller's earth activated with the 

 aqueous extract of brewers' yeast with the interposition of a collodion 

 membrane, and (3) brewers' yeast autoclaved for 6 hours at 121° C. 



Pigeons on this test diet without supplement declined in weight to 

 from 60 to 70 per cent of normal and died of polyneuritis in 30 to 40 

 days. When the diet was supplemented by 0.2 to 0.4 gram of the yeast 

 extract, by 0.01 gram of activated fuller's earth, or by 0.01 gram of 

 activated fuller's earth plus 1 gram of autoclaved yeast, the pigeons 

 showed slight loss in weight and a slight dejection but were otherwise 

 healthy. The addition of minute quantities of whole wheat or untreated 

 yeast prevented this loss, and promoted growth. A repetition of these 

 experiments substituting polished rice for the Sherman-Spohn diet gave 

 essentially the same results, except that the birds receiving no supple- 

 ment died sooner. 



Young rats receiving no supplement lost weight rapidly and died 

 of polyneuritis. On the basal diet supplemented with 0.03 gram of 

 yeast extract plus 1 gram of autoclaved yeast or with 0.01 gram of 

 activated fuller's earth plus 1 gram of autoclaved yeast, growth was 

 normal. With 0.01 gram of activated fuller's earth as the supplement, 

 there was slow growth at first, followed by a decline of several weeks' 

 duration. With 1 gram of autoclaved yeast as the supplement there was 

 slight growth, followed by decline, polyneuritis, and death. 



The authors interpreted these findings to confirm the conclusion of 

 previous workers that at least two factors formerly included in the 

 concept "vitamin B," a heat-labile vitamin (B) and a more heat-stable 

 vitamin (G) are necessary for the growth and well being of young rats. 

 Pigeons appear not to require the heat-stable factor, but to need in 

 addition a third factor which is found in untreated whole wheat or 

 yeast, but not in autoclaved yeast nor in some purified antineuritic 

 preparations. 



Experimenting with pigeons on a "synthetic diet," adequate except 

 for the "vitamin B complex," Lecoq (1927) and Randoin and Lecoq 

 (1927d) found very different values for different yeasts and their ex- 

 tracts as sources of the substance necessary to prevent polyneuritis and 



