OTHER TYPES OF WATER INCREMENT 



59 



any one agent that produces water excess, are not uniform, quanti- 

 tative relationships can supersede categorical statements in de- 

 scribing the enhancement and inhibition of water diuresis. At one 

 load and time the rates of recovery of water content are diverse 

 but are numerically comparable. 



1 r 



m second and later hours 



-2 +2 



Total Wo+er Load 

 Fig. 38. Comparison of net exchanges of water in dogs subjected to several types of 

 water load. Ordinates, % of Bo/hour; abscissae, % of Bo. The curves selected are each 

 derived from 4 or more tests, as indicated in figures 39 (J), 16 (M), 29 (L, T), 35 (N, P), 

 34 (R, V), 6 (K), 31 (S, U) ; and treated with pituitary extracts studied by Molitor, '26a 

 (X). Gains in negative loads are compared in the first 1.0 hour of recovery, except for the 

 steady ingestion (L) by the dog with esophageal fistula; losses in positive loads are com- 

 pared at times after 1.0 hour, being the maximal rates of net exchange found. 



§ 17. Deficits of water 



Water-drinking ordinarily follows water deficit. No dog un- 

 assisted gains water by route other than the mouth; dogs without 

 food drink less (Kleitman, '27) ; dogs after physical exercise drink 

 more (Gerhartz, '10) ; dogs ingest other amounts of any solution 

 offered them in place of water (Wettendorff, '01). Both excretion 

 and ingestion are quantitatively graded activities; so also are 

 mobilization and absorption. 



An example of recovery from another type of water deficit is 

 the sequel of sucrose infusion (Keith and Whelan, '26). After two 

 hours of intravenous administration of 1.46 M solution, four hours 

 are allowed for further loss of water through diuresis accompany- 

 ing excretion of the sugar. Then water is offered during one to 

 five hours, with the recoveries shown in figure 39. The quantities 

 ingested are less at every deficit than those of figure 11, as figure 40 



y 



