26 THE VITAMINS 



Chamberlain, Vedder, and their associates (1911) of the United States 

 army medical commission for the study of tropical diseases in the 

 PhiHppines were able to report in 1910 the rapid eradication of beri- 

 beri from the native troops known as Philippine Scouts, and promptly 

 began a systematic investigation looking toward the chemical identifica- 

 tion of the antineuritic substance. As has been mentioned briefly in the 

 preceding chapter, they found the neuritis-preventing substance to be 

 soluble in water and alcohol but insoluble in ether, readily dialyzable 

 through an ordinary parchment membrane, rather readily adsorbed 

 by bone black, and gradually decomposed by heating at temperatures 

 in the region of 115° C. to 125° C. Attempts to identify it with any 

 one of a number of salts and organic phosphorus compounds, with 

 choline or lipoids of the lecithin group, and with arginine, histidine, 

 asparagine or other amino acids were unsuccessful. They suggested 

 that, though not identical with any of the nitrogen compounds tested, 

 the antineuritic substance might prove to be a nitrogenous base but not 

 an alkaloid. 



Simultaneously with this work, Fraser and Stanton (1911) had 

 shown that the antineuritic substance is soluble in both alcohol and 

 water, stable to heat in acid solution, and much more readily destroyed 

 in alkaline solution. 



Cooper and Funk (1911) reported that dried, pressed yeast hy- 

 drolyzed for 24 hours with 20 per cent sulfuric acid still retained its 

 curative properties. They also confirmed the results of Fraser and 

 Stanton concerning the antineuritic action of the alcoholic extract of 

 rice polishings and carried the process further by finding that the 

 active substance was completely precipitated from a water solution 

 of the extract by means of phosphotungstic acid and that on decom- 

 posing the precipitate with barium hydroxide an active substance free 

 from phosphorus, carbohydrate, and protein was obtained. Following 

 this, Funk (1911) announced the isolation from rice polishings of a 

 crystalline nitrogenous compound which he held to be the curative 

 substance. Shortly afterward (1912a) he corrected some of his pre- 

 vious statements regarding this substance, which he provisionally named 

 beriberi vitamine (1912c). At this time he offered evidence indicat- 

 ing that it was a free base probably belonging to the pyrimidine 

 group analogous to uracil and thymine and possibly a constituent of 

 nucleic acid. 



While later work has hardly supported such definite conclusions 

 as to the chemical nature of the antineuritic substance, yet considerable 

 interest attaches to the experimental evidence which led to the intro- 



