402 PHYSIOLOGICAL REGULATIONS 



simultaneous quantities, two loads and two rates of exchange, are 

 established. 



I now consider the second sort of experiment. Negative heat 

 loads together with positive water loads follow the drinking of 

 ice water (fig. 145). Recoveries of both components simultaneously 

 are thereafter accomplished while sitting. Relating heat load with 

 water load (K, fig. 184), I observe that the load of heat as estimated 

 increases after the load of water begins to diminish. But later 

 the load of heat diminishes the more rapidly of the two (as judged 

 by the fraction of the load disposed of in a unit of time), so that 

 heat balance is at the end of 2 hours more nearly restored than 

 water balance ; the same fact appears in J also. At every stage of 

 K the rates of net exchange of heat and of water are known ; indeed 

 the total rates also were measured (fig. 145) but are not plotted 

 here. The two exchanges, when each related to loads of their own 

 component, yield two equilibration diagrams (N and Q). 



Thus two of the four possible combinations of positive and 

 negative loads of two components are worked out; the other two 

 an experimenter could secure by appropriate arrangements, such 

 as ingesting hot water to make both loads positive, and injecting 

 pilocarpine to make both loads negative. Further, each admin- 

 istered load might be varied in diverse tests, particularly in rela- 

 tive magnitudes of the two components, each yielding data for a 

 ''loop" diagram. While the development of loadings might be 

 regarded as controlled to a considerable extent by the experi- 

 menter, the recoveries are not, in so far as they freely proceed in 

 a uniform environment. 



What comparisons of simultaneous quantities are facilitated by 

 the type of diagram shown in fig. 184? The following may be men- 

 tioned: (l) loads of two components, (2) positive and negative 

 loads of each component, (5) time relations of loading and unload- 

 ing, (4) rates of net exchange of two components, (5) rates of load- 

 ing and of recovery at one load, and (6) four quantities ascertained 

 at one time (2 loads and 2 rates). 



Quantitative relations, in this as in every other diagram, in- 

 crease in clearness as time is spent in working with them. The 

 number of data contained in this figure is no greater than in a table, 

 but more relations are shown than would be explicit by non- 

 graphical methods. The four quantities recorded do not just 



