VITAMIN G (B2) 139 



(1929), who observed liver and kidney tissue (rat) to be approximately 

 10 times as rich in vitamin G as voluntary muscle. Carlsson further 

 found cardiac muscle five times, brain two and one-half times, spleen 

 three times and blood one-third as rich per gram fresh tissue as volun- 

 tary muscle. 



A few unpublished experiments by Stiebeling (personal communi- 

 cation, 1930) indicate that fresh lean beef contains approximately one 

 Bourquin unit per gram. Lean beef muscle was demonstrated by Gold- 

 berger and his colleagues (1920, 1924, 1926) to be a good source of the 

 pellagra-preventing factor. When fed to the extent of 50 grams protein 

 in a 2,400 Calorie ration, either fresh or cooked and dried, it contained 

 more than minimal amounts to prevent black-tongue in dogs; pork 

 liver, incorporated into the diet to the extent of 43.5 grams pro- 

 tein in a 2,400 Calorie diet appeared to be a good source of the black- 

 tongue preventive. Three hundred grams canned salmon per 2,400 

 Calories afforded complete protection to the dog (Goldberger, 1928) ; 

 six ounces daily (Goldberger and Wheeler, 1929) prevented human 

 pellagra. 



Hoagland and Snider (1930), using an alcoholic extract of white 

 corn meal as the vitamin B (Bi) supplement for the basal vitamin B- 

 free diet, secured from good to excellent growth in rats on the addition 

 of moisture-free commercial beef extract as the source of vitamin 

 G (B2). In similar experiments with dried lean beef as the source of 

 vitamin G, 25 per cent sufficed for excellent growth. From these results 

 it was estimated that 1 pound of concentrated beef extract contains 

 approximately as much vitamin G as 11 pounds of fresh lean beef. 



More recently Hoagland and Snider (1930a) have reported that 

 beef, pork, and lamb muscle contain approximately the same amounts 

 of vitamin G, from 15 to 25 per cent of the dried material sufficing for 

 excellent growth. Beef spleen was about as rich, and beef and pork 

 liver and beef kidney from 5 to 8 times as rich as muscle meats in 

 vitamin G. 



Vegetables. — According to unpublished data of Hartley (personal 

 communication, 1930), the juice from canned tomatoes contained 0.16 

 of a Bourquin unit of vitamin G (B2) per cubic centimeter. According 

 to Goldberger and Wheeler (1927) forty ounces of this material daily 

 prevented pellagra. Goldberger, Wheeler, Lillie and Rogers (1928) 

 found that upwards of 30 cubic centimeters per kilogram may be 

 needed to protect dogs from black-tongue. They further report that 400 

 to 450 grams cooked carrot daily was found inadequate to prevent 

 human pellagra; and only when the allowance exceeded 40 grams per 



