COERELATIVES OF WATER CONTENT IN OTHER SPECIES 239 



remarkable that three independent studies (Dresel and Leitner, 

 '29, '31; Gregersen and Bullock, '33; Marx, '35, p. 79) show that in 

 both positive and negative increments, AVd is eight times AW ; or, 

 only 13 per cent of the body weight takes part in the distribution 

 of the water increment. If consistency of results is a basis for 

 trusting them, these though not numerous are highly trustworthy. 



When Dresel and Leitner ( '29) investigated the effect of ingest- 

 ing only 50 ml. of water (0.1% of Bq), a volume that does not 

 usually induce diuresis, the ''plasma" in four subjects apparently 

 increases by 6.6 per cent, a volume which itself is three times that 

 of the ingested water. It is true that dye volumes are measured 

 with limited accuracy, yet this series differs significantly from con- 

 trols. Much remains to be learned in the relations of AVd to body 

 load of water, it seems. 



"Corpuscular" volumes are, in the three investigations men- 

 tioned, modified almost as much as "plasma" volumes insofar as 

 hematocrit estimations indicate the ratios between them. But when 

 persons without spleens were tested, then in excesses of water the 

 total circulating "corpuscular" volumes are no longer modified 

 (Dresel and Leitner, '29). Individuals having certain diseases in- 

 volving livers or kidneys also show no modifications of ' * plasma ' ' 

 volumes after drinking water in excess (Oka, '38a). 



Few other volumes of distribution have been measured in any 

 type of measured water increment. If the object is to find a quali- 

 tative increase in some Vd with increase in the body's water con- 

 tent, that has been accomplished. If modifications of volume are 

 to be relied upon as indicators of water deficit and excess, adequate 

 quantitative correlations must be made. 



(2) Dilutions. The weights and the water contents of human 

 tissues are known from autopsy materials, but not their changes 

 with water increments. With respect to dilutions of blood con- 

 stituents, some few quantitative relations can be made out from 

 data confined to three types of water increment, namely: single 

 ingestions by mouth, continued ingestions by mouth, deficits by pri- 

 vation. It is readily recognized that other types of increment in 

 man yield other results, as was the case in dog. 



The time courses of modifications in dilution have been reported 

 several times for chloride of whole blood in water excesses (Priest- 

 ley, '21 ; Marx, '26 ; Dresel and Leitner, '29 ; Farkas, '32 ; Smirk, 

 '33). The diversity, both in amount of dilution and in temporal 



