Water Retention 



533 



eral experiments of each kind on eight students were briefly as 

 follows : 



Water alone. An increased output of urine was noticeable 

 in 30 minutes, reached a maximum in from one to one and one- 

 half hours and was over in four hours. Chloride excretion was 

 irregular but in general fell as the water excretion increased. Two 

 maxima of nitrogen excretion were noticeable — the first about 

 10 A. M. and the second about 2 P. M. which is noteworthy in 

 view of the fact that no lunch was taken, indicating apparently 

 the influence of habit. 



Water and Cane Sugar. No noteworthy effect on the water 

 output was noted until amounts of sugar of over 150 grams 

 were given. With 180 gms. of sugar the increased urine output 

 began and reached approximately the same maximum at the 

 same time as with water alone but decreased much more rapidly 

 reaching the same low point about an hour sooner but showing 

 a second moderate maximum at from one to two hours after the 

 first low point. By the end of another hour the output was back 

 to the low (normal) level again, indicating a retention of water 

 by the sugar. 



The nitrogen excretion showed the same two maxima as when 

 water alone was given while the chloride did not fall as rapidly 

 as with water alone. 



A few experiments were made to determine the amount of 

 salt necessary to cause complete retention of a liter of water for 

 a period of five or six hours. In general about 14 grams of 

 NaCl was found to be necessary. 



