1915] Charles J. Robinson and J. Howard Mueller 117 



in which the disagreement between his findings for wheat-bran, and 

 those of Patten and Hart and ourselves, is explained. The existence 

 in wheat-bran of a phytin-spHtting enzyme, a "phytase," active in 

 dilute hydrochloric acid sol., accounts fully for the failure to isolate 

 in all cases from wheat-bran the inosite hexaphosphate Compound. 

 We refer above (p. 115), to the possible occurrence of such an agent. 

 As to the reason why this enzyme has been active in some instances 

 and not in others, there appear to be two possibilities. Either the hy- 

 drochloric acid used for extraction, having been made up roughly 

 to 0.2 percent, was somewhat stronger and therefore (as has been 

 shown) inhibitory to the phytase; or, in the case of our work, which 

 was conducted during the winter months, the original extraction hav- 

 ing been made in a cold room at a temperature not above 10° C, 

 the enzyme was inactivated by the low temperature. 



