220 



PHYSIOLOGICAL KEGULATIONS 



AQ are each correlated with AW. Then, still under these condi- 

 tions, AM and AN, AP and AQ, etc., also vary in parallel. Con- 

 versely, AM, AN, AP and AQ characterize the state of the organism 

 with respect to water load, and AW may in turn be found from its 

 correlation with them. All this is implicit in table 24. 



The relation of hemoglobin dilution of the blood to water load 

 of the body as a whole (fig. 124) might be an especially useful one, 

 for having once established the relation, A/Hb = 1.03AW, data re- 

 corded in the past would become available for the study of water 

 loads in which body weights were not measured at suitable inter- 

 vals, but in which hemoglobin dilution was measured, as was the 



+8 M^ +16 



Total Water Load 

 Fig. 124. Increment in dilution of whole blood (% of initial) in relation to total 

 water load ( % of Bo) . Dog. Eepeated administration of water by stomach. Triangles 

 and dash line, dilution of whole blood chloride, in two individuals of Underhill and 

 Sallick ('25). Circles and solid line, dilution of hemoglobin, in four individuals of 

 Underhill and Sallick and in two individuals of Greene and Eowntree ('27). Occasion- 

 ally 2 or 3 determinations were made during one test. 



case in figure 125. Before further conclusions are drawn, however^ 

 it may be recalled that dilution of hemoglobin is in other studies 

 (table 24) not accurately related to water load. Increments in 

 hemoglobin dilution might also be expected to parallel increments 

 in "red cell" volume in water excesses, whereupon it is found (fig» 

 114) that at + AAV = 8 the volume of distribution of carbon mon- 

 oxide ( Vd) is not significantly different from the Vd at AW = 0. 



The changes undergone simultaneously by the various concen- 

 trations measured are diverse. At a chosen time, some, as A/Clg 

 (fig. 125), indicate more dilution than the increment in volume of 

 the "plasma" (fig. 114). Others indicate about the same or less 

 dilution than the increment in volume of "whole blood," but not 

 all dilutions measured in whole blood do so. Many plausible ex- 



