176 



Scientific Proceedings (60). 



diet, there was observed a diminution of the urea-nitrogen elimi- 

 nated during the first six hours after the benzoate ingestion, a 

 diminution corresponding to the nitrogen eliminated as hippuric 

 acid-nitrogen. 



Periods. 



Total 

 Nitrogen. 



Urea + NH, 

 Nitrogen. 



Undetermined 

 Nitrogen. 



Hippuric Acid 

 Nitrogen. 



I— III, control 



3-521 

 3.760 



3-074 

 (87.3%) 



2.436 

 (64.8%) 



0-447 



I.324 

 (0.481) 





VIII-X, benzoate 



0.843 





If the hippuric acid-nitrogen be subtracted from the unde- 

 termined N (shown in parentheses), the undetermined N is com- 

 parable with that of the control periods. This indicates that in 

 man as in rabbits and pigs, the glycocoll available for synthesis into 

 hippuric acid may be derived at the expense of substances whose 

 N normally appears in the urine as urea-nitrogen. At the end of 

 six hours the greater part of the hippuric acid had been eliminated 

 and the urea elimination had become normal again. 



No free benzoic acid nor glycuronates could be detected in the 

 urine, indicating a complete conversion to hippuric acid and a 

 very rapid elimination. In order to ascertain whether the rapidity 

 of elimination was influenced by the liquid diet of the preceding 

 experiment, the work was repeated on the same subject on a mixed 

 diet, and on a purine-free diet. In both experiments, the greater 

 part (85-95 per cent) of the hippuric acid was eliminated within 

 six hours. Another subject received six grams of sodium benzoate 

 and eliminated the greater part of the hippuric acid within six 

 hours. An amount of sodium hippurate equivalent to the ben- 

 zoate fed was administered, and the elimination of the hippuric acid 

 studied. The rate of elimination was practically identical with 

 that of the benzoate experiments. This indicates the great 

 rapidity with which the human organism can detoxicate and 

 eliminate a toxic substance such as sodium benzoate. 



