VITAMIN B (Bi) 47 



cure and the other the "glucose" cure. The former can be avoided 

 by leaving the birds in a warm place for at least two hours before 

 treatment and the latter by giving a small dose of glucose in water 

 at the same time that the bird is being tested for the heat cure. 

 This technique was followed by Guha and Drummond (1929) in 

 testing various concentrates obtained in an effort to isolate 

 vitamin B (Bi) from wheat embryo. Since they were primarily inter- 

 ested in this vitamin as required for normal nutrition of rats and 

 other animals, their investigation will be noted in greater detail in the 

 following section, but it is of interest that in following the procedure 

 of Jansen and Donath full confirmation of their results were obtained 

 at various stages of fractionation through that of precipitation with 

 platinic chloride. According to Drummond (1930) the concentrate at 

 various stages had the following activity in curative day doses for 

 pigeons (the material being injected subcutaneously) : Material sepa- 

 rated from "activated" fuller's earth, 2.6 milligrams ; silver fraction 

 at pH 6.5, 0.18 milligrams; phosphotungstic acid fraction, 0.014 milli- 

 gram; alcohol-soluble fraction 0.014 milligram, and platinum chloride 

 fraction 0.005 milligram. 



A further examination of the Jansen-Donath method has been re- 

 ported by Williams and Eddy ( 1927-28, 1928-29) and Williams, Water- 

 man, and Gurin (1930), using both yeast and rice polishings as the 

 original material, and both rats and pigeons as test subjects. Various 

 deviations from the original Jansen-Donath procedure and the use of 

 protective rather than curative tests make impossible a quantitative 

 comparison of their findings with those of Jansen and Donath, but 

 they report a good qualitative but poor quantitative relationship be- 

 tween their concentrates and those of Jansen and Donath at various 

 stages. Vitamin hydrochloride crystals supplied by Jansen and Donath 

 were used in protective tests for pigeons on a polished rice diet. With 

 doses of 0.04 milligram daily polyneuritis and death were much re- 

 tarded. 



deCugnac (1929) applied the method of fractional precipitation 

 to extracts prepared by the Seidell (1926) method, using as solvents 

 water, acetic acid, and formic acid and as precipitants alcohol, acetone, 

 ether, and picric acid. With successive precipitations with 70, 80 and 

 87 per cent alcohol and acetone, fractions were obtained similar in 

 their vitamin B content, as determined by the Seidell (1924) method, 

 but at each step freer from inorganic material. This was interpreted 

 as indicating that the apparent precipitation of vitamin B (Bi) is 

 really a phenomenon of adsorption rather than precipitation. The active 



