36 THE VITAMINS 



sodium carbonate and precipitated with bismuth potassium iodide. After about 

 iive hours the grayish yellow precipitate, which at this point consisted chiefly 

 of choHne, was filtered off, the filtrate treated with one-tenth its volume of 20 per 

 cent hydrochloric acid and again precipitated with bismuth potassium iodide, with 

 long and thorough shaking. At this point the active material was in the precipitate, 

 a brick red to purple powder to which the name oridin fraction was given. This 

 was immediately filtered with strong suction, triturated with silver carbonate and 

 again filtered. The slightly alkaline, silver-containing, active filtrate was at once 

 made slightly acid with hydrochloric acid, and, after removal of the precipitated 

 silver chloride, evaporated to dryness in vacuo at low temperature. A slightly 

 colored, deliquescent mass of crystals formed which, in doses of 5 to 10 milligrams 

 daily, was capable of curing poli-neuritis in pigeons. On treatment with gold 

 chloride a yellow double salt, corresponding to the formula CsHnNOz.HCl. AuCU 

 was obtained which on decomposition yielded a free base isomeric with betaine 

 and valine and probably containing the pyridine or piperidine groups, but which 

 possessed no antineuritic properties. 



In discussing this loss in activity two possible explanations were 

 suggested, (1) that the antineuritic vitamin (or antineuritin as it was 

 called) was present in the oridin hydrochloride only as an impurity and 

 was set free from it and lost on further purification and (2) that the 

 oridin hydrochloride was actually the salt of antineuritin, but that in 

 the process of purification it became an inactive isomer. The latter view, 

 in harmony with the theory of Williams, was apparently favored by 

 Hofmeister at this time. Later, Hofmeister (1923) attributed the losses 

 of vitamin, in attempts to purify it, to adsorption by precipitates of 

 other substances, as had Drummond in 1917. 



Seidell (1921a) recorded the preparation of a stable silver vitamin 

 compound from activated fuller's earth. 



Saturated aqueous barium hydroxide solution in the proportion of one liter 

 per 100 grams of the activated fuller's earth was used for the extraction of the 

 active material, the mixture being shaken vigorously for three minutes and the 

 solid removed as rapidly as possible, preferably by means of a De Laval cream 

 separator. The nearly clear liquid was immediately acidified with a slight excess 

 of concentrated sulfuric acid, a moderate excess of powdered barium carbonate 

 was added to remove the excess of sulfuric acid, and the mixture filtered after 

 about thirty minutes. After the removal of non-active material from the filtrate 

 by precipitation with a saturated lead acetate solution, and of the excess lead 

 by hydrogen sulfide, the resulting filtrate was concentrated to a small volume 

 by rapid vacuum distillation, the white amorphous material, separating out 

 toward the end, removed by filtration, and the final concentrate reduced to a thick, 

 pasty, semisolid condition by allowing it to stand several days in a vacuum desic- 

 cator. 



On diluting to a volume of 25 cubic centimeters the extract thus prepared 

 from 300 grams of activated fuller's earth and adding gradually an almost satu- 

 rated aqueous silver nitrate solution, a voluminous silver precipitate devoid of 

 antineuritic properties was obtained. When the liquid resulting from centrifuging 

 and washing this precipitate was treated with an excess of fairly concentrated 

 aqueous ammoniacal silver nitrate solution another voluminous precipitate formed. 

 This second precipitate, which proved to be highly antineuritic as tested by feeding 

 to pigeons on a polished rice diet, was further purified of an easily crystallizable 

 inactive compound by adding a slight excess of hydrochloric acid to a suspension 

 in water, removing the silver chloride formed and slowly evaporating the clear 

 aqueous solution in a vacuum desiccator until crystals ceased to form. On remov- 



