A FOURTH CONTRIBUTION TO THE ETIOLOGY OF BERIBERI.' 



By Edward B. Vedder.^ 

 {From the United States Army Board for the Study of Tropical Diaeaaea.) 



Soon after our last paper (l) was submitted for publication, 

 our attention was attracted by the work of Funk. (2) This in- 

 vestigator claims that the neuritis-preventing substance which 

 is absent in polished rice and is contained in rice polishings is an 

 organic base which is completely precipitated by phosphotungs- 

 tic acid. It will be remembered that we had failed to precipi- 

 tate the neuritis-preventing substance with phosphotungstic 

 acid, but that we had used basic lead acetate as a reagent before 

 employing phosphotungstic acid. This suggested the possibility 

 that we had failed to precipitate the desired compound with 

 phosphotungstic acid because it had been previously destroyed by 

 the basic lead acetate. 



Experiment 22. — A portion of extract of rice polishings pre- 

 pared as described previously was, therefore, treated with a suf- 

 ficient quantity of a saturated solution of phosphotungstic acid 

 to produce complete precipitation. This precipitate was fil- 

 tered off and the remaining filtrate was tested as follows : 



Four fowls were fed on polished rice with a daily addition of 

 10 cubic centimeters of this filtrate which contained that portion 

 of the extract of rice polishings that was not precipitated by 

 phosphotungstic acid. 



One case of neuritis appeared after twenty-eight days when 

 this experiment was discontinued. 



The precipitate obtained from the extract when treated with 

 phosphotungstic acid was then ground in a mortar with freshly 

 slaked lime and baryta according to the method we had pre- 

 viously employed. Calcium phosphotungstate was then filtered 

 off, and the remaining filtrate, which should contain any organic 



• Published with permission of the Chief Surgeon, Philippine Division. 



' Captain, Medical Corps, United States Army, member of the United 

 States Army Board for the Study of Tropical Diseases as they Exist in 

 the Philippine Islands. 



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