A STUDY OF THE DIETARY ESSENTIAL, WATER-SOLU- 
BLE B, IN RELATION TO ITS SOLUBILITY 
AND STABILITY TOWARDS REAGENTS. 
By E. V. McCOLLUM anp N. SIMMONDS. 
(From the Laboratory of Agricultural Chemistry of the University of Wis- 
consin, Madison.) 
(Received for publication, November 12, 1917.) 
Since the discovery by Eijkman (1) of a means of producing 
an experimental polyneuritis in birds by feeding them a diet 
restricted to polished rice, and its relief by feeding rice polishings, 
interest in the problem of the isolation and identification of the 
curative substance has steadily increased (2). Without excep- 
tion the methods which have been adopted for the isolation of 
the physiologically active substance have involved extracting it 
with either water or alcohol and subsequent precipitation with 
phosphotungstie acid, mercuric chloride, or silver nitrate and 
barium hydroxide. The former reagent has been employed ex- 
tensively. The decomposition of the phosphotungstic precipi- 
tate by means of alkali such as barium hydroxide has been found 
to be attended by great loss of curative properties of the prepa- 
rations. Better success has attended the use of barium acetate 
and of lead acetate for this decomposition (3). 
The various modifications of the methods of separation, which 
were based upon precipitation with reagents, have yielded but 
meager results, and it seemed to us that prospects for success in 
the isolation of this interesting substance must be based upon an 
_ entirely different line of procedure from that employed in the 
past. It was with a view to the development of a new method 
for the separation of the physiologically indispensable substance 
which we term water-soluble B (4), and which we believe to be the 
specific complex, a lack of which causes the development of 
polyneuritis, that the experiments reported in this paper were 
conducted. The plan contemplates a complete study of the 
solubility of the water-soluble B in all organic solvents available. 
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