i6 Fractionation of Phosphotungsfic Acid Precipitate 



tions. The various phosphotungstates obtained by this method 

 show entirely different aspects, so that certainly a crude Separation 

 was affected. 



Summary of general conclusions. The phosphotungstate 

 percipitate from alc. extract of yeast can be divided, by means of 

 acetone, into two f ractions : a small insohihle f raction, which con- 

 tains the hulk of Vitamine; and a large soluhle one, which is totally 

 inactive. The phosphotungstates were decomposed with lead ace- 

 tate instead of with baryta. This method offers two advantages : 

 it yields very clear Solutions, which facilitate further purification, 

 and it avoids the use of alkaH. 



In the case of autolyzed yeast, from which a larger yield of 

 Vitamine may be expected, the acetone method produces an insoluble 

 fraction which represents 34 percent of the total precipitate. By 

 using 25 percent, 100 percent, 50 percent, and 75 percent acetone 

 sol., in this order, it is possible to separate the phosphotungstate 

 precipitate into four soluble fractions, and into a fifth insoluble one 

 representing only about 13 percent of the total precipitate. 



BIBLIOGRAPHY 



1. Funk: Jour. of PhysioL, 191 1, xliii, p. 395. 



2. Edie, Evans, Moore, Simpson and Webster: Ann. of Trop. Med. 



and ParasitoL, 1912, vi, p. 235. 



3. Funk : Jour. of PhysioL, 1912, xlv, p. 75. 



4. CoopER and Funk: The Lancet, 191 1, ii, p. 1266. 



5. Suzuki, Shimamur^v and Odake : Biochem. Zeit., 1912, xliii, p. 89. 



6. Funk: Jour. of PhysioL, 1913, xlvi, p. 173. 



7. Drummond and Funk : Biochem. Jour., 1914, viii, p. 598. 



8. Funk : Jour. of PhysioL, 1914, xlviii, p. 228. 



9. Wechsler: Zeitschr. f. physioL Chem., 1911, Ixxiii, p. 139. 



IG. Funk and v. Schönborn : Jour. of PhysioL, 1914, xlviii, p. 328. 

 II. Cooper: Biochem. Jour., 1914, viii, p. 250. 



