VITAMIN B (5i) 41 



"By fractionation of a product of 63 T.A. in mixtures of ether and alcohol 

 in which the amount of water was reduced to a minimum, three fractions were 

 obtained: (a) a gummy fraction thrown out of the alcohol by the addition of 

 mere traces of ether, (b) an intermediate fraction thrown out by ether up to 

 four volumes of ether to one of alcohol, and (c) a fraction soluble in ether- 

 alcohol. The last contained an oil, comparatively insoluble in water. Fractions 

 (a) and (c) were relatively inactive. The intermediate fraction when treated 

 with silver sulfate in acid solution threw down an inactive precipitate. From the 

 centrifugate after treatment with silver nitrite in the presence of hydrochloric 

 acid, ammoniacal silver hydroxide threw down a precipitate, which was extracted 

 with hydrochloric acid and alcohol, and yielded a preparation of 1190 T.A. . . . 

 This contained ammonium chloride as an impurity, and some evidence has already 

 been obtained that the activity may be pushed to 3,000 T.A. This being so, it 

 does not seem unlikely that the activity of torulin itself may prove to lie between 

 10,000 and 100,000 T.A. or in the region of 0.001 milligram per day for the 

 normal pigeon. This would only bring it into line with substances like pituitrin." 



Two feeding experiments were reported with growth curves show- 

 ing that doses of this concentrate which protected against polyneuritis 

 for many days did not cause an increase in weight of the pigeons after 

 cure of the polyneuritic symptoms. This was thought to support the 

 view that vitamin B consists of two factors. (Compare Williams and 

 Waterman, 1927.) 



Influenced by the work of Levene and van der Hoeven (described 

 later), Seidell (1926) modified his general procedure for obtaining 

 an antineuritic vitamin concentrate from yeast in two essentials — first, 

 by using sodium hydroxide in place of barium hydroxide to liberate 

 the vitamin from its combination with fuller's earth, and glacial acetic 

 acid in place of sulfuric to acidify the resulting extract, (in 1929 the 

 use of sulfuric acid was again recommended,) and second, by using 

 strong alcohol to precipitate the active material from this extract after 

 removal of the sodium salts and other inactive material. The addition 

 of successive portions of 98 to 100 per cent alcohol to the thick 

 viscous paste resulting from the evaporation under reduced pressure 

 of the purified extract from the fuller's earth converted it into a non- 

 hygroscopic powder. From pigeon tests (1926) it was estimated that 

 approximately one-third of the total vitamin contained in 5 kilograms 

 of activated solid is found in about 150 grams of the non-hygroscopic 

 powder. The losses of active material were attributed to the impossi- 

 bility of liberating all of the vitamin from its combination with fuller's 

 earth, the destruction of the vitamin by the various treatments to which 

 the solutions are subjected during the process, and the impossibility 

 of separating the vitamin completely from the inactive fraction by 

 the method employed. Numerous tests for activity of the powder have 

 shown that it prevents loss in weight in pigeons in doses of about 

 0.010 gram given on alternate days. In 1929, Seidell pointed out that 



