THE ANTIBEKIBERI VITAMINE 169 



removal of silver and sulphuric acid, the solution was acidified with 

 nitric acid, and then treated with silver nitrate till it gave a brown 

 precipitate with baryta. 



A saturated baryta solution was then added so long as a drop of 

 the clear solution gave even a slight white precipitate on addition of 

 ammoniacal silver nitrate solution. The precipitate was then 

 washed free of nitric acid, decomposed with hydrogen sulphide, the 

 last traces of baryta removed with very dilute sulphuric acid, and 

 concentrated in vacuum. The solution thus obtained was very 

 active. By means of the gradual evaporation of the solution in the 

 desiccator, with the addition of alcohol, a colorless crystalline sub- 

 stance was obtained. This weighed 0.4 gram out of 50 kilos of rice 

 polishings (secured from Malay). The very small yield prevented 

 further work, it being possible only to make a series of reactions. 

 The needle-like crystals, melted sharply at 233C. (uncorrected) and 

 were rather insoluble in cold water and cold alcohol. At that time, 

 no other substance could be found in this fraction. 



As to the therapeutic action of the product, we expressed ourselves 

 only with great caution, but beyond all doubt there was a curative 

 action present. The amount used for a curative dose contained only 

 four milligrams of nitrogen. Smaller doses were not tried at the 

 time. 



In a later publication (I.e. 62), we called this active substance 

 "beriberi vitamine," to make it evident that it contained nitrogen 

 and was indispensible for life. 



To illustrate our procedure, we append a schematic diagram. 



Rice polishings > Alcohol extract > Watery extract 



S 

 Phosphotungstic acid precipitate > Filtrate 



. / \ \ 



KC1 Sublimate Silver nitrate and baryta. 



4 i. 



Choline Vitamine. 



Still later, we attempted to simplify our procedure (I.e. 324). In 

 the first place, the rice polishings were extracted with ordinary alcohol 

 instead of acid alcohol. The watery extract was then immediately 



