COERELATIVES OF WATER CONTENT 229 



ations some physiologists are ready to make ''derivations" {sensu 

 Pareto, '35, p. 508) relating anorexia and gastric motility, which 

 they do not make relating gastric motility and water content of the 

 body. 



It may be pointed out that going without food is a possible 

 means of conserving water to the body. In extreme water deficits, 

 food that is eaten is actually regurgitated and thus rejected. With- 

 out food, less water is excreted, both in urinary and in evaporative 

 paths (Morgulis, '23, p. 133, p. 266) ; and the water already present 

 more nearly suffices to maintain the gradually shifting balance of 

 water. 



(3) Energy transformations. In the body as a whole, energy 

 metabolism is most often studied in the particular stages of energy 

 transformation represented by oxygen consumption and by carbon 

 dioxide output. No change in over-all rate was found in 3 hours 

 after placing warm water in the stomach in amounts up to 2% of Bq 

 (+2 AW) (Bidder and Schmidt, 1852; Eubner, '02; Lusk, '12). 

 But after administering loads of + 10 AW by stomach, Heilner 

 ( '07) found increases of 10 and 18 per cent in rate of carbon dioxide 

 elimination. 



Rates of oxygen consumption increase only at certain times 

 during water excess, indicating therefore less relation to water load 

 than to interval after introduction. Increases of 20 to 600 per cent 

 may occur for short periods after fluids isotonic with blood are 

 rapidly introduced by vein (Davis, '35), but disappear entirely 

 before the load has been eliminated. 



Significant modifications in respiratory quotient with water 

 loads of the type discussed here have, I believe, not been found. 



(4) Renal clearances, or ratios of the rate of excretion of any 

 constituent to the concentration of that constituent in blood or in 

 plasma, are greatly modified with water content of the body. For 

 the most part the correlations already made are with rate of uri- 

 nary water excretion (Austin et at., '21). However, having estab- 

 lished the relation between AW and AW/At, perhaps choosing the 

 steady state for the comparison, I indicate that the relation of load 

 to the renal clearance (fig. 129) is equally significant with that of 

 rate. 



With this information at hand, it next appears possible that the 

 increased output of diverse substances at the same plasma concen- 

 tration of them can account for the depletions of nitrogen, phos- 



