WATER EXCHANGES OF DOG 



39 



0.41/hour. These values show in numbers how much more is done 

 in that interval of time to compensate for deficits. 



Velocity quotients vary not only with loads but also with time 

 (fig. 19). The largest variations are in initial periods, for in these 

 periods the ingestion in deficit is sudden while the excretion in 

 excess is gradually augmented. After the first hour, velocity 

 quotients in positive loads often become nearly constant (fig. 19, 

 A and B). This indicates that the quotients found during falling 



Hour>5 



Fig. 19. Total velocity quotient (1/hour) in relation to time after single administra- 

 tion of water by stomach. These velocity quotients are obtained by dividing rate of total 

 water output by total water load, using the data of figure 6. Times at which half the 

 administered load had been disposed of are indicated (1) from figure 1. 



rates of excretion and at loads above + 1% of Bo serve to charac- 

 terize more broadly the exchanges that prevail. 



Under limited conditions, then, the velocity quotient (rate/load) 

 compares numerically the exchanges that occur at various loads, 

 by various paths, at various times. Very often it is constant 

 throughout considerable ranges of load or of time. It will be seen 

 later (§71) that it is a parameter in an equation that describes the 



