32 



August Krogh and Marie Krogh. 



In our experiments also the excretion of nitrogen generally begins 

 to rise very soon after the nitrogen meals (curves I C. W., II, III, IV 

 A. S.), but there are some exceptions to this rule and the rise may 

 be postponed for 5 to 10 hours (curves I M. D. ,IV N. D.). In IV 

 N. D. large quantities of Л' were taken at 10 and 12, and in the period 

 from 12 — 8 there is a distinct fall in N excretion. The excretion of 

 water falls still more while the concentration rises. There has un- 



Fig. 11. Exp. II. Curves for urine and output of CO.^,. 



doubtedly been retention of N due to lack of water for its excretion, 

 and we find that the excretion both of water and N rises suddenly 

 between 8 and 10 and reaches extremely high figures: 300 cc. of water 

 and 4.55 gr. N per hour. In exp. I M. D. the excretion of N rises 

 suddenly 4 hours after the intake of TV, but up to this the N excretion 

 is extremely low and the concentration falling. The retention of N 

 cannot therefore in this case have been due to lack of water in the 

 organism. 



3. The mutual interdependence of water excretion and N ex- 

 cretion is shown very distinctly by our curves. Almost every time 



