Chapter III 



OTHER TYPES OF WATER INCREMENT (DOG) 



§ 15. It seems useful to examine further compensatory ex- 

 changes of water, before the dog's other manifestation of water 

 regulation are examined. In the investigation of water equilibra- 

 tion already presented, only one general method of producing 

 excess and only one of producing deficit are considered; positive 

 loads are imposed through administration by stomach and negative 

 loads through privation. These two types of positive and negative 

 increment, and various sorts of stipulated conditions, were arbi- 

 trarily chosen; scores of alternatives are possible. 



Data exist for water exchanges following some of the alterna- 

 tive modifications of water content, and I now inquire what features 

 of the physiological recoveries are similar, and what ones differ, 

 among them. There is no way other than actual comparison of 

 finding whether or not, for instance, what Keith ('24) called 

 ''dehydration" is the physiological equivalent of what Gamble 

 ('29) called ''dehydration." How does the dog indicate equiva- 

 lence among possible deficits or excesses of water ? Does ' ' excess ' ' 

 of water content always call forth polyuria, and one rate of urinary 

 output 1 



§ 16. Excesses of water 



Types of water load may be provisionally grouped according to 

 manners of their production. 



a. Does an anesthetized dog with water load differ from the 

 same individual unanesthetized? It is widely recognized that it 

 usually does ; the present object is to treat the differences as quanti- 

 tative ones. In positive loads of water, the rates of elimination 

 are diminished under the influence of ten out of eighteen narcotics 

 tested by Bonsmann in a variety of concentrations. A few results 

 are shown in table 2. The other narcotics, such as papaverine in 

 the dose tested, do not diminish water diuresis. None of them 

 augments the returns by significant amounts, indicating that, as 

 usual, processes are not hastened by imposed agents. 



In negative loads the rates of water intake under anesthesia are 

 zero. When stated thus, any alternative seems preposterous ; but 

 that does not keep physiologists from doing experiments which 



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