120 THE VITAMINS 



similar results were obtained as with the autoclaved yeast alone until 

 the beef was supplemented with alcoholic extract of corn (equivalent 

 to as little as 5 per cent of corn in the diet), when prompt recovery 

 and growth followed. 



These results are in harmony with those reported by other workers, 

 especially Hauge and Carrick and Smith and Hendrick, but in the in- 

 terpretation of them Goldberger and his associates went farther than 

 these investigators through suggesting a correlation of the pellagra- 

 preventing vitamin with the other factors present in yeast as follows : 



"Thus, autoclaved yeast and beef muscle contain a factor distinct 

 from the polyneuritis-preventing vitamin which in combination with the 

 antineutric is essential for the growth of the rat. From the facts pre- 

 sented, it seems probable that this is the same as factor P-P, and some 

 of the work in the very confusing literature relating to the identity of 

 the 'growth-promoting' complex of 'water-soluble B' with bios appears 

 to us to be in harmony with this interpretation. Further investigation 

 will, however, be required to determine this. 



"In any event investigators using the rat-growth test must here- 

 after recognize and take due account of at least two essentials (B sensu 

 stricto and P-P) where heretofore only one was considered. This is, 

 perhaps, of special importance to those heretofore occupied in the 

 chemical isolation of the beriberi vitamin. It may well be suspected that 

 the highly 'active' concentrates supposedly of vitamin B (sensu stricto) 

 that some of these workers have succeeded in preparing, in proportion 

 as they enable the rat to grow in the absence of any other source of 

 the 'water soluble B' in the diet, are concentrates of at least two factors. 

 The rat-growth test may continue to be used as a test of the purity 

 of a concentrate, but must be interpreted in a sense opposite to that 

 heretofore current. The pure concentrate will be seemingly inert. The 

 complete test of such a concentrate (or a food substance) will necessi- 

 tate combining it alternately with an adequate proportion of a proved 

 preparation of the antineuritic and of the P-P factor, respectively, and, 

 perhaps, of both, and this or some equivalent test will have to be made 

 before an apparently inactive preparation (or food) can be adjudged 

 as really inert. It is, at least, possible that in the past, workers in dis- 

 carding 'inactive' fractions have unwittingly been throwing away the 

 very thing they were laboriously seeking. This may perhaps explain, at 

 least in part, the somewhat unaccountable losses of vitamin in the 

 process of fractionation of 'active' preparations." 



In a more detailed report of their study of the effect of the pellagra- 

 preventing vitamin upon rats, Goldberger and Lillie (1926) illustrated 



