VIII. B, g Vedder and Williams: Vitamines in Rice 177 



kilograms of polishings with 14 liters of 95 per cent alcohol in 

 three successive macerations, while we have for some time been 

 using 30 liters of alcohol to extract each 5 kilograms of polish- 

 ings, it seemed possible that the extract used by Strong and 

 Crowell was only partially successful in preventing beriberi be- 

 cause insufficient alcohol was used completely to extract the 

 protective substances from the polishings. In order to obtain 

 more definite information on this point, the following experi- 

 ment was performed. 



Experiment 39. — Five kilograms of polishings were extracted 

 with 15 liters of 95 per cent alcohol. The polishings were 

 pressed, and the dry residue again extracted twice in a similar 

 manner, using 8 liters of fresh alcohol each time. The extracts 

 obtained from these three processes were kept separate, the 

 alcohol evaporated off, the fat removed, and the residue diluted 

 with water according to our usual method. 



(a) Four fowls were fed on polished rice plus the substances 

 obtained on the first extraction. An amount equivalent to 10 

 grams of polishings was given each fowl daily. All 4 fowls 

 remained well for a period of three months when the experiment 

 was discontinued, 



{h) Four fowls were fed on polished rice plus the substances 

 obtained on the second extraction. An amount equivalent to 

 10 grams of polishings was given each fowl daily. All 4 

 fowls remained well for three months when the experiment was 

 discontinued. 



(c) Four fowls were fed on polished rice plus the substances 

 obtained on the third extraction. An amount equivalent to 10 

 grams of polishings was given each fowl daily. All 4 fowls 

 remained well for three months when the experiment was 

 discontinued. 



(d) Four fowls were fed on polished rice plus a daily dose 

 of 10 grams of the polishings that had been extracted three times 

 with alcohol. All 4 fowls remained well for a period of three 

 months when the experiment was discontinued. 



This experiment shows that even three successive extractions 

 with 95 per cent alcohol, using a total of 6 liters of alcohol to 

 each kilogram of polishings, are insufficient to remove all of the 

 protective substances from rice polishings. We may, therefore, 

 conclwde that the protective substances are only slightly soluble 

 in cold 95 per cent alcohol, and that it is very probable that the 

 extract used by Strong and Crowell in the experiment already 

 quoted failed to confer complete protection because the polishings 

 were incompletely extracted by the quantity of alcohol they used. 



