INTERRELATIONS AMONG COMPONENTS 411 



quantitatively correlates 7 components that were measured simul- 

 taneously. These interrelate the state of and what is happening in 

 the whole with the state of its parts. In the same manner equilibra- 

 tions also might be represented, as they exist simultaneously in 

 diverse parts of one organism. They would indicate the competi- 

 tive rates of recovery among the parts. 



(3) In man, water was withdrawn from the diet to varying 

 extents, and in daily periods the net exchanges of seven electrolytes 

 were measured (Wiley and Wiley, '33). Conversely, to constant 

 diet and water intake each of four salts in equivalent amounts was 

 added in a separate period (Wiley, Wiley and Waller, '33). Dia- 

 grams may be constructed by plotting the body's load of one 

 against the load of another, upon which each period traces a differ- 

 ent loop. It was found that deficit of water leads to deficit of 

 electrolytes, and excess of electrolytes leads to excess of water, a 

 relation that is, however, only qualitatively reciprocal. 



In other tests on man, water and varying amounts of sodium 

 chloride were taken by mouth either together or separately 

 (Adolph, '21). The load and the rate of exchange, of water and of 

 chloride, depended on the relative times and amounts in which they 

 arrived in the body. Water might be depleted by salt excess when 

 intake of water was denied. Evidently interrelations need not be 

 limited to simultaneous states but may relate what follows with 

 what precedes. Very many speculations suggest how electrolytes 

 may be related among themselves and to water in the human body ; 

 planned experiments can test all of them quantitatively. 



In a third set of tests on man, sodium chloride was withdrawn 

 from the diet, while the exchanges of water and several electro- 

 lytes were measured (Goodalland Joslin, '08; Stohr, '34; McCance, 

 '36, '37). Deficit of sodium led to deficit of water and of some 

 electrolytes ; numerous correlations are possible that are limited by 

 the fact that each individual was tested differently. Going further, 

 if the researches of Tuteur ('10), Wiley, and others had been 

 planned to allow correlation with these latter ones, the same 

 amount of manipulative effort would have produced results capable 

 of a high degree of synthesis. 



There is no great trick to finding interrelations among com- 

 ponents ; most researches in physiology that are at all quantitative, 

 ascertain data suitable for the sort of study here illustrated. A 

 point to be emphasized is that a constant proportionality, or an 



