72 THE VITAMINS 



promoting" has always been associated with vitamin B. In this same 

 paper Osborne and Mendel showed for the first time that there is a 

 quantitative relationship between the appetite-stimulating vitamin B 

 and the amount of growth, an observation confirmed the following year 

 by Drummond (1918). The outward effect on rats of deprivation of 

 vitamin B was described by Drummond as follows : "For some time 

 after the water-soluble factor has been withheld from the diet the gen- 

 eral appearance of the animals is apparently normal. They are lively, 

 sleek-coated, and bright-eyed. As the period of maintenance at constant 

 body weight draws to a close, the rats gradually lose this appearance. 

 The fur loses its gloss and becomes ruffled, whilst the rats assume a 

 hunched attitude, and become lethargic. During the final decline the 

 rats appear pale and emaciated, feeling cold and thin to the touch, and 

 they usually remain huddled in corners away from the light." Occa- 

 sionally symptoms resembling those of avian polyneuritis were noted 

 by Drummond, but usually the rats died before the appearance of such 

 symptoms. 



Karr (1920), working in Mendel's laboratory, demonstrated with 

 dogs failure of appetite and decreased food consumption on diets de- 

 ficient in vitamin B, followed by a revival of appetite and increased 

 food consumption when vitamin B preparation was fed. As the vitamin 

 preparation was given separately from the food the effect could not be 

 attributed to increased palatability. The quantity of the vitamin prepa- 

 ration necessary to sustain the appetite, while varying slightly with 

 different animals, appeared to be fairly constant for the same animal. 

 It was noted in this paper that in certain of the animals which continued 

 to eat their food for a longer time without the addition of vitamin B, 

 characteristic polyneuritic symptoms appeared which were promptly 

 alleviated by administration of the vitamin extract. 



This suggestion that stimulation of the appetite is a function of 

 the antineuritic factor B is confirmed by Sandels' (1928) study of the 

 food consumption of rats receiving respectively, (a) diets free from 

 vitamin B ( Sherman-Spohn basal diet supplemented by autoclaved 

 yeast) and (b) diets practically free from vitamin G (Sherman-Spohn 

 basal diet supplemented by a strong-alcohol extract of ground whole 

 wheat). Chick and Roscoe (1928) also state that on a basal diet ade- 

 quate except for vitamin G, young rats can be maintained for three 

 months or more at practically constant weight, with fair appetites. 

 Metabolism studies reported by Karr (1920a) suggested that the nitro- 

 gen utilization in the digestive tract was unaffected by the absence of 

 vitamin B, although it was pointed out that "metabolism experiments 



