

METABOLISM IN NEPHRITIS 



TABLE 29 



373 



SHOWING THE VARIATIONS OF SPECIFIC (!RAVITY READINGS IN DIFFERENT DISEASES WITH 

 THE TEST DAY FOR RENAL FUNCTION. (Mosenthal, 1915) 



* Last two figures only. 



correctly. It must also be remembered that the activity of the kidney is 

 composed of different functions, that to a certain degree act indepen- 

 dently of one another; it is well known, for instance, that the power to 

 excrete salt and urea is not synchronously curtailed in a great many cases ; 

 but to claim that a study of either one is of no importance because the 

 elimination of the other does not parallel it, is obviously absurd. 



When renal function becomes impaired the specific gravity tends to 

 become fixed, that is, instead of a variation of 9, there may be only a differ- 

 ence of one or two points. (Table 29.) In only two conditions, excepting 

 the normal individual with an inadequate water intake, is a high fixed 

 specific gravity found ; these are passive congestion and certain cases of 

 nephritis accompanied by albuminuria and edema. It is very satisfactory 

 to note that on chemical examination of the urine these cases can usually 

 be identified because of the high concentration of nitrogen and the low 

 percentage of sodium chlorid present in the urine. An example is given in 

 Table 30. 



