32 THE VITAMINS 



while the third appeared to be nicotinic acid. The vitamin fraction from 

 rice poHshings yielded nicotinic acid and a substance to which the 

 formula C26H20O9N4 was assigned. The work of Suzuki ct al. was 

 discussed in this paper and in greater detail in one by Drummond 

 and Funk (1914) in which were reported the results of an extended 

 study of the phosphotungstate precipitate from rice polishings obtained 

 according to Funk's earlier method. They were not only unable to 

 obtain the active products mentioned by the Japanese investigators 

 but failed also in isolating the curative substance of rice polishings 

 by an extension of their previous method which had pointed to success. 

 From an exhaustive fractionation of the phosphotungstic acid precipi- 

 tate they succeeded in isolating comparatively large amounts of choline, 

 nicotinic acid and betaine, together with small amounts of the purines, 

 guanine and adenine, and traces of a substance which they considered 

 might possibly be guanidine. 



The substance to which Funk had previously assigned the formula 

 C26H20O9N4 and which, with nicotinic acid, had been obtained from 

 the portion containing practically the whole of the curative substance 

 was definitely proved to be also nicotinic acid. "All trace of the cura- 

 tive substance had disappeared and a fraction which originally had 

 shown very marked curative properties now consisted of nothing other 

 than nicotinic acid which possesses very slight action. All attempts 

 which we have made to isolate the elusive curative substance from 

 this fraction, in which it originally occurs, have failed." This throws 

 doubt upon Funk's earUer isolation of a vitamin of melting point 

 233° C. and gives point to Barger's suggestion that this may have 

 been only nicotinic acid contaminated with the active substance. 



Seidell (1916), adopting a method used by Lloyd in working with 

 alkaloids, found that Lloyd's reagent, a special form of fuller's earth 

 (hydrous aluminum silicate), effectively adsorbed the vitamin from 

 autolyzed yeast solution. When 50 grams of the fuller's earth per 

 Hter of the autolyzed yeast solution was used the vitamin was practi- 

 cally all adsorbed and the solid could then be washed with successive 

 portions of very dilute acid, water, and small amounts of alcohol, 

 and finally dried in a vacuum desiccator, thus affording a stable form 

 of the vitamin. Both preventive and curative experiments were made 

 with this material. Prompt and effective cures of completely paralyzed 

 pigeons resulted from 0.05 gram doses of the activated solid, corre- 

 sponding to 1 cubic centimeter of the original yeast filtrate. The same 

 amount fed alternate days to pigeons on a polished rice diet proved 

 sufficient to keep the birds in normal health and weight. 



