VITAMIN B (B^) 89 



conditions would we expect the vitamin B deficiency of commercial 

 evaporated milks to be due to methods of manufacture." Daniels et al. 

 (1929) found evidence that both heat and subjection to aeration lower 

 the antineuritic value of evaporated and pasteurized milks. Sherman 

 and Spohn (1923), using powdered milk and reconstituted milk as a 

 vehicle for vitamin B in the dry and liquid state, respectively, found 

 that prolonged heating at 100° C. was more destructive of the vitamin 

 B in the liquid milk than in the dry. While these experiments were 

 conducted before the differentiation of vitamins B and G, it is certain 

 that vitamin B was being measured, both because it is the limiting 

 factor in cow's milk for growth, and because it is the more thermolabile 

 of the two. 



Human milk may perhaps contain vitamins B and G in different 

 proportions from cow's milk. Osborne and Mendel (1922a) found 5 

 cubic centimeters daily of mixed human milk to furnish insufficient 

 vitamin B for normal growth in young rats, but when dried and fed 

 in the form of tablets, the equivalent of 10 cubic centimeters sufficed 

 for normal growth. Macy, Outhouse, Graham, and Long (1927a) 

 reported that from 14 to 15 cubic centimeters daily of mixed human 

 milk were required to secure even subnormal growth in young rats. 

 From 25 to 30 cubic centimeters were required for normal growth and 

 development in the younger animals and 35 cubic centimeters for con- 

 tinued growth in larger animals weighing 200 to 240 grams. The young 

 of female rats receiving as much as 35 cubic centimeters of the milk 

 were subnormal and few survived the nursing period. The addition of 

 0.4 gram daily of autoclaved yeast brought about renewed growth in 

 a few rats which had ceased to grow. In a comparative study of cow's 

 milk, using identical methods. Outhouse, Macy, Brekke, and Graham 

 (1927) found that from 20 to 25 cubic centimeters of milk daily were 

 required for normal growth in young rats for a period of 12 weeks. 

 A daily supplement of 0.4 gram of autoclaved yeast was without effect, 

 but the same amount of fresh dried yeast brought about an immediate 

 response in growth in rats which had ceased to grow on the 25 cubic 

 centimeters allowance of milk. These results would suggest that of 

 these two water-soluble, growth-promoting vitamins in human milk 

 the limiting factor is the heat-stable vitamin G and in cow's milk the 

 heat-labile vitamin B. This difference if confirmed might be attributed 

 to the food ; the human diet may be poorer in vitamin G than that of 

 a cow on a ration consisting more largely of leaves. 



Cereals and Breadstuffs. — The whole grains of the cereals are fairly 

 rich in vitamin B and a diet consisting largely of grain products would 



