Hippuric Acid after Benzoate Ingestion. 175 



ous and water immiscible substances which imitate the tissue so 

 far as the production of currents is concerned can be analyzed in 

 all details much more easily than the tissue itself. The work 

 along this line is not yet entirely finished, the results obtained so 

 far show that biological potential differences are located at the 

 junction of water immiscible fatty membranes and aqueous solution 

 and that their magnitude is determined by peculiar phenomena of 

 distribution. These phenomena of distribution can be fully 

 accounted for by well-established physiochemical laws, but they 

 are of rather complicated nature. 1 



The biological potential differences are not determined by 

 ionic mobility as has been frequently assumed. 



The methods used in this work are essentially physiochemical. 

 The results obtained so far may appear insignificant to the physi- 

 ologist as most of the more important electrophysiological ob- 

 servations especially those connected with irritation (action 

 currents) remain unexplained. However the explanations for all 

 these phenomena which the alteration theory can put forward are 

 very hypothetical. It therefore seems justified at the present 

 time to try a thorough explanation on the basis of well known 

 physical laws of the very simplest electric phenomena observed in 

 tissues. 



107 (924) 



The synthesis and rate of elimination of hippuric acid after ben- 

 zoate ingestion in man. 



By Howard B. Lewis. (By invitation.) 



[From the Department of Physiological Chemistry, University of 

 Pennsylvania, Philadelphia, Pa.] 



Ten grams of sodium benzoate were administered to a healthy 

 man on a diet of milk, butter, and cane sugar, i. e., glycocoll-free. 

 The urine was collected at two hour intervals, and the relation 

 between the elimination of hippuric acid and urea studied. As 

 compared with the corresponding control periods on the same 



1 The details of this work are published in the Journal of the American Chemical 

 Society, XXXV, 344 (1913), Transactions of the American Electrochemical Society, 

 XXIII, 401 (1913), Zeitschrift f. Electrochemie, XIX, 319 (1913). 



