406 



Scientific Proceedings (124). 



carried out. A portion of the urine was also used for the isola- 

 tion of hippuric acid according to Dakin's method. 1 On account of 

 the difficulty of removing pigments the method in our hands was 

 not adapted for the quantitative estimation of hippuric acid but 

 it did serve to establish the presence of this substance qualita- 

 tively. In the second series of experiments attempts were made 

 to estimate benzoyltaurin directly. A volume of urine was eva- 

 porated to dryness and extracted with ethyl acetate in accordance 

 with the procedure used by Dakin for the estimation of hippuric 

 acid. After evaporating the ethyl acetate an estimation of neu- 

 tral sulfur was carried out on the aqueous solution of the residue. 

 The result of an experiment in which benzoyl taurin was added 

 to normal urine indicated a recovery of 70 per cent. 



The data indicate that no appreciable synthesis of benzoyl- 

 taurin takes place in the body when taurin and benzoic acid are 

 simultaneously administered. The increase in neutral sulfur 

 (62 per cent, of the taurin sulfur) and in amino nitrogen (60 per 

 cent, of the taurin nitrogen) of Subject No. 1 agrees with the 

 results of former work on the output of taurin when ingested by 

 man. The experiments carried out on dog No. 1 also indicates 

 a recovery (S = 59 per cent., NH 2 = 66 per cent.) or about 60 

 per cent, of the dose of taurin which was given. The figures for 

 neutral sulfur in the experiments of series II are within the limits 

 of the normal variability and indicate that benzoyltaurin was not 

 present in amounts which can be estimated. The figures for 

 benzoic acid indicate that this substance was almost quantita- 

 tively recovered. The presence of hippuric acid in the urine was 

 established in all of the experiments. 



Synthesis of Bezoyltaurin. 



Baum 2 who prepared the benzoyl derivatives of a number of 

 the amino acids by treating them with benzoyl chloride reports 

 that he was unable to similarly synthesize benzoyltaurin. Later 

 the substance was prepared by Gabriel and Heymann 3 from 



'Dakin. H. D.. and Hawk, P. B.. "Practical Physiological Chemistry," Phil- 

 adelphia, 1918, p. 543. 



•Baum. J.. Z. physiol. Chem., 1885. ix. 465. 



3 ( iat>rirl, S., and Heymann, P.. Berichle, 1890, xxiii, 157. Gabriel, S. and 

 Colman, J., lirruhte, 191 1, xliv, 3628. 



