206 The Philippine Journal of Science 



possible that this extract no longer possesses its full curative 

 properties when it ages. Treatment of chicken 4 was begun- 

 on the one hundred sixteenth day of the experiment ; consequently 

 the extract used had been made for some time. Williams 8 has 

 recently shown that hydroxy pyridines have antineuritic proper- 

 ties, but these curative effects are lost after a solution stands for 

 some time or more quickly when warmed. Evidence that the 

 antineuritic compounds in autolyzed yeast undergo a change 

 probably due to dynamic isomerism has been presented by Wil- 

 liams and Seidell. 9 A preparation from cardiac muscle loses its 

 ameliorative power in a few days. 10 A similar change may be 

 the cause of the apparent lessened activity with age of the 

 hydrolyzed extract used in these experiments. 



The method of extraction with infusorial earth appears in- 

 applicable, due to the inability of small quantities of infusorial 

 earth to absorb the total vitamine content of the hydrolyzed 

 extract of rice polishings. 



SUMMARY 



A study of the antineuritic properties of infusorial earth ex- 

 tracts of the hydrolyzed extract of rice polishings is reported. 



Only a part of the vitamine content of the extract was ex- 

 tracted by the proportions of infusorial earth used. 



There appears to be a loss of antineuritic power in the extract 

 as it ages. 



8 Williams, R. R., Journ. Biol. Chem. (1916), 25, 437. 



8 Williams, R. R., and Seidell, Atherton, ibid. (1916), 26, 431. 



10 Cooper, Evelyn A., Biochem. Journ. (1914), 8, 347. 



