1912] On the Distribution of Potassium in Renal Cells 401 



dish till a constant weight was obtained ; it was then carefully inciner- 

 ated and the soluble portion of the ash extracted with hot water acidu- 

 lated with hydrochloric acid. From the combined extraction fluids 

 the calcium and magnesium and the sulphuric and phosphoric acids 

 were removed by precipitation and filtration, and the filtrate, treated 

 with hydrochloric acid, was evaporated to dryness, then heated to 

 expel any traces of ammonium chloride. The residue, which consisted 

 of the chlorides of sodium and potassium, was carefully weighed, then 

 appropriately treated by the platinum method to determine the amount 

 of potassium present, which, calculated as the chloride and subtracted 

 from the total chloride found, gave the amount of sodium chloride present. 

 In the dogs' kidneys the same method of estimating the total sodium 

 and potassium present was used, but only one kidney was used in each 

 analysis. 



The analyses gave the following : — 



Frog. 



Analyses 



Sodium 



Potassium 



Na(=ioo) : K 



Dog. 



Analyses 



Sodium 



Potassium 



Na(='ioo) : K 



In the analyses are, of course, included the sodium and potassium of 

 the blood and lymph held in the excised kidney, and this constitutes a 

 source of error, for the more blood and lymph the dog's kidney con- 

 tains the lower is the proportion of the potassium to the sodium. Abder- 

 halden's" analyses of dog's blood gave 0.2721 per cent, of sodium and 



