PHYSIOLOGICAL CHEMISTRY. 



holism. Now, the conductivity measures the combined effect 

 of these products of oxidation and, if it could be determined 

 apart from the effect of the chlorides, a factor of considerable 

 practical importance would be secured. 



Approximately, the conductivity due to metabolic products 

 may be found by subtracting from the observed conductivity 

 that due to sodium chloride in the same solution. The chlorine 

 may be accurately determined and calculated as chloride ; then 

 from tables the conductivity for a solution of this concentration 

 may be found and used as a correction to be taken from the 

 total observed conductivity, leaving the desired residual or 

 metabolic conductivity. In this plan, however, an error is in- 

 volved, because the conductivity of the chloride taken from 

 the tables directly is that found in pure aqueous solution in 

 absence of other salts, and is larger than the true conductivity 

 of the chloride as it exists in the urine. It is necessary, there- 

 fore, to use as a correction the value of the salt conductivity, 

 not in aqueous solution, but in a solution of a concentration 

 corresponding to that of urine. 



Several attempts have been made to measure the conductivity 

 of mixtures of electrolytes and formulate the results. Most of 

 the experiments have been made with dilute solutions and can 

 not be used well in cases like the present one. The author has 

 investigated the question with special reference to mixtures like 

 the urine and has considered the effect of urea as a non-elec- 

 trolyte also. The conductivity varies from individual to in- 

 dividual, and from hour to hour according to the kind and 

 amount of food metabolized, but is seldom above * = 0.03. 

 The following table illustrates the variations in the urine of 

 two men, both well nourished on mixed diet, with the water 

 consumption intentionally high. 



By making complete urine analyses and duplicating the re- 

 sults by mixing the inorganic and organic ions and the non- 

 electrolytes in proper proportion, it is possible to reach almost 

 exactly the corresponding urine conductivity as shown, for ex- 

 ample, with the urines the complete analyses of which were 



