336 



HERMAN O. MOSENTHAL 



of the blood, the level of the non-protein nitrogen of the blood and marked 

 renal injury all play their part in producing these various pictures. 



It becomes clear from what has been said, that the determination of 

 nitrogen in the urine has but a limited applicability to measuring the 

 efficiency of renal function. A single determination of the non-protein 

 nitrogenous constituents of the blood furnishes a much clearer conception 



CHART 2 



Comparative curves of excretion of urinary nitrogen as compared with amount of 

 nitrogen of the control periods in experimental uranium nephritis in dogs. Various 

 types of elimination are shown. Arrow indicates time of uranium injection. Solid line 

 across chart indicates level of urinary nitrogen during control period ; curves above line, 

 excess of excretion; below, retention. Line of dashes, Dog 10; dotted line, Dog 23; 

 solid line Dog 25. (Mosenthal(o), 1914.) 



of how the kidney is acting (see comparative value, uric acid, urea and 

 creatinin in the blood in nephritis). If the urea is low, the coefficient of 

 urea excretion or the percentage relation of the urea nitrogen to the non- 

 protein nitrogen will indicate the ability of the kidney to excrete the end 

 products of protein metabolism. (See the relation of the urea to the total 

 non-protein nitrogen of the blood in nephritis.) It is really a great satis- 

 faction to realize that a single determination of non-protein nitrogen or 



