44 CHAMBERLAIN, VEDDER, AND WILLIAMS. 



containing the precipitate obtained by basic lead acetate and 

 dissolved after removing the lead with hydrogen sulphide. 



One fowl developed neuritis in twenty-five days, 1 in twenty- 

 eight days and 1 in twenty-nine days, after which the experiment 

 was discontinued. 



Experiment 11. — Four fowls were fed on polished rice plus 

 a daily dose of 10 cubic centimeters of Extract Number 25, 

 containing the histon bases. 



One fowl developed neuritis in twenty days and 1 in twenty- 

 eight days, after which the experiment was discontinued. 



Experiment 12. — Four fowls were fed on polished rice plus 

 a daily dose of 10 cubic centimeters of Extract Number 26, 

 containing amino-acids. 



Two fowls developed neuritis in twenty-six days and 1 in 

 thirty-one days, after which the experiment was discontinued. 



In order to check these experiments we also fed fowls with pure 

 chemical substances of the amino-acid group and with amids. 

 Glycocoll, asparagin, and succinamid were chosen as represent- 

 ing the general classes of amino-acid and amid substances 

 likely to be present in the extract of rice polishings. Thus 

 glycocoll or amino-acetic acid contains an amino radical at- 

 tached to a carbon atom. Asparagin or amino-succinamic acid 

 contains 1 amino and 1 amid group (NH^), while succinamid 

 contains 2 amido groups. 



Experiment 13. — Four fowls were fed on polished rice plus 

 a daily dose of 10 cubic centimeters of a 0.5 per cent suspen- 

 sion of glycocoll in water. 



One fowl developed neuritis in thirty days and 1 in thirty- 

 five days, after which the experiment was discontinued. 



Experimejit lU. — Four fowls were fed on polished rice plus 

 a daily dose of 10 cubic centimeters of a 0.5 per cent solution 

 of asparagin in water. 



One fowl developed neuritis in thirty-two days and 1 in 

 thirty-three days, after which the experiment was discontinued. 



Experiment 15. — Four fowls were fed on polished rice plus 

 a daily dose of 10 cubic centimeters of a 0.5 per cent solution 

 of succinamid in water. 



One fowl developed neuritis in twenty-nine days and 1 in 

 thirty-one days, after which the experiment was discontinued. 



The doses of these substances used in the above experiments 

 were selected because it was certain from the chemical analysis 

 that the amount of rice polishing which is known to be sufficient 



