A N A L Y T I C A L CHEMISTRY
1662 tion is small. If a solution of barbital containing 15 y per ml. (final concentration after dilution according to Goldbaum's method) has been completely hydrolyzed t o the eethylbutyrylurea, the absorption would indicate the presence of 3% of the original weight of barbital. Likewise, if the barbital were completely bydrolyBed to diethyl malonuric acid the absorption would indicate the presence of 6% of the original weight of barbital. The results obtained indicate that the method for determining. barbital concentration may be used for following the rate of hydrolysis of barbital provided that a 5% accuracy is satisfactory.
ACKNOWLEDGMENT
T h e authors express their appreciation to the Research C o p . for the grant which made this research poasihle. LITERATURE CITED
(1) Daimler. C.,Ann.. 249, 181 (1888). (2) Fisoher. E., m d Diltheu, H., Ibid., 335, 362 (1904). (3) Freund. M.,and Herrrnan, P.,Ber., 23, 189 (1890). . , 1604 (1952).
