The Chemical Investigation of the Phosphotungstate Precipitate from Rice-Polishings.

The chemistry of rice-polishings has attracted many workers ever since it was shown that there occurred in the polishings a substance, apparently of a relatively simple chemical constitution, which had a powerful curative effect when administered in cases -of beri-beri, or experimental beri-beri, produced by a diet of polished rice. Practically all the communications which have appeared on the subject have, however, concerned themselves chiefly with that particular fraction of the polishings which contained the curative substance and have to a greater or less extent neglected other fractions which were obtained. The objects of this investigation were, primarily, to repeat the attempt to isolate the curative substance in a pure condition, and, at the same time, to carry out as exhaustive an examination of the other simple nitrogenous substances contained in the phosphotungstic acid precipitate as possible, in the hope that some new substance might be isolated which could be regarded as a degradation product of the unstable curative substance. We will not give a detailed account of the findings of previous workers, but will refer to and discuss them in the course of the description of our work.