SECRETION AND EXCRETION 341 



plasma; the NaCl content of the urine of nephritics approaches that 

 of the plasma. The same fact seems to obtain for the other crystal- 

 loids, including water. 



Inasmuch as the functionally inadequate kidney continues to 

 ultrafilter but ceases to regulate the ultrafiltrate, it likewise loses 

 its function as a regulator of the entire organism; it is no longer able 

 to maintain the "milieu interieur. " The diminished excretion of 

 crystalloids by insufficient kidneys causes an increase in the crystal- 

 loidal content of the blood as was first shown by A. VON KORANYI by 

 measuring the freezing point depression (cryoscopy). 



The Result of Deficient Kidney Function Upon the Organism. 



If in animal experiments both kidneys are removed, an hydremia 

 develops even though no water is given, or if the water removed 

 by respiration and through the skin is just replaced. If a ne- 

 phritic is given n water ad libitum, the hydremia does not increase 

 at all, or when it has reached a given grade only to an insignificant 

 extent; the tissues which have been deprived of water take it up 

 again. 



There thus develops between blood and tissues an equilibrium in 

 which more water enters the blood than normally. This is not sur- 

 prising since there is in functionating kidneys a dynamic equilibrium 

 inasmuch as there is a current of water from the tissues into the 

 blood and from the blood into the bladder. When the kidneys and 

 water maintenance are both deficient, a static equilibrium occurs, 

 which (to the extent that we .may speak of it in a living system) 

 represents the true water equilibrium between blood and tissues. 

 The question now presents itself: is this equilibrium conditioned by 

 osmotic relations or by the condition of swelling of the colloids in the 

 blood and the tissues? 



The investigations of A. VON KORANYI, P. F. RICHTER and W. 

 ROTH, H. STRAUSS, KOVESI and SURANYI show that the Cl content of 

 the blood serum of nephrectomized animals and nephritic men is 

 not materially increased; nor has the electrolyte content increased, 

 but on the contrary the freezing point depression of nephrecto- 

 mized rabbits rises from 0.56 to 0.60 (normal) to from 0.65 to 0.75 

 (A. VON KORANYI). In spite of the increased concentration of the 

 nonelectrolyte crystalloids, the content of water has been increased. 



Let us imagine what would happen if matters were under the 

 sole influence of osmotic conditions. Ever since PFLUGER'S ob- 

 servations, we know that metabolic processes occur in cells. Con- 

 sequently, an increased osmotic pressure would have to be present 



