WATER EXCHANGES OF DOG 



43 



duration and course of the previous loading. Slow and prolonged 

 administration yields slower excretion at any one load. Further 

 evidence of difference is observed in other ways. The highest out- 

 put rates in series K to N are found when intake rate exceeds 

 output rate ; series A to F further exaggerates this factor. During 

 intake the rate is higher than after it, as though incoming water is 

 more promptly excreted than water already incorporated. 



Q 2. d 6 



Hours 

 Fig. 22. Course of sensible water load (% of Bo), i.e., ingested water minus urine 

 excreted, with repeated water administration. In the first 2.5 hours, water is given by 

 stomach tube in ten equal portions, and the loads are designated as in figure 21. Half 

 of the maximal load is returned at 1. The total amounts of water given are: K 10.0% 

 •of Bo, L 6.0%, M 2.14%, N 1.40%. Data of Kingsley and Adolph. 



Which of the data shown may be considered characteristic of 

 the stationary state of load? A stationary state strictly exists 

 only in those limited periods where neither contents nor rates of 

 •exchange manifest a marked trend. A marked trend is (for the 

 present) one in which the component may be shown to have changed, 

 either consistently or statistically significantly, within three of the 

 .successive periods of time in which its exchange is measured. 



