COKRELATIVES Or WATER CONTENT 225 



samples of urine vary around one concentration and in all negative 

 loads around another, with a steep transition between. Many other 

 concentrations (chloride, urea) and ratios (chloride/creatinine) of 

 urinary constituents yield equal correlations with water load. Over 

 all, one conclusion emerges, namely, that in water diuresis, rate of 

 output of water augments more than of other substances. In the 

 long run, little else slips out of the body with it; its excretion is 

 highly specific. 



§ 82. Concentrations of other body FLuros 



Digestive juices are collected from fistulas while dogs are sub- 

 jected to diverse types of body load of water. It is believed that 

 the total particulate (electrolyte) concentrations in most juices are 

 equal to those of blood plasma simultaneously. Some at least of 

 those constituents {e.g., bicarbonate) that increase in concentration 

 in deficits of water, do so in both blood and juice (Herrin, '35), 

 The drained juices, wherever available, therefore serve as auto- 

 matically extruded samples of analyzable body substance. They 

 are equivalent to any other sort of sample in indicating a part of 

 the distribution of water increments. 



<^ 83. Other compositions 



In the whole body of the dog with water load, few changes in the 

 total amounts of materials other than water have been measured. 

 To ascertain them, the whole body need not be analyzed, for with 

 greater accuracy the increments in content of those materials are 

 ascertained from determinations of intake and of output of them. 

 Nitrogen is said to be characteristically lost in water privation 

 (Straub, 1899; Spiegler, '01). It is uncertain whether the amount 

 lost from the body is related to the duration of the water deficit 

 more than to the extent (- AW) of it; in all cases the negative load 

 of nitrogen (-AN) amounts to less than 1 per cent of the nitrogen 

 in the body. Retentions of nitrogen are sometimes found, espe- 

 cially in short periods of water privation ; these are related to the 

 retention of urea and probably of other substances at low rates of 

 water excretion (§84 (4) ). Phosphorus is reported to be retained 

 with nitrogen (Landauer, 1894; Straub, 1899). 



Water excess leads to depletion of several measured chemical 

 constituents, as nitrogen, phosphorus, chloride, creatinine, and acid 

 (Heilner, '06; Underbill and Sallick, '25; Greene and Rowntree, 



