Body Water Compartments throughout Lifespan 107 



for the relative water contents of plasma and interstitial 

 water, and for the Donnan effect. As the extracellular water 

 according to the method applied here shows a higher normal 

 value than is obtained with the thiosulphate method the 

 results for extracellular and intracellular water in this series 

 will not be directly comparable to the findings in the group of 

 children. 



Table III 

 Body water compartments in adults, absolute values 



Sex 



Males 

 Females 



Age range 



23-54 

 23-51 



Body weight 

 kg- 

 72-5 

 59-8 



Water compartments in litres 

 TBW ECW ICW 



38-9 



28-7 



16-8 

 13-3 



22-1 

 15-4 



The absolute average values for total body water, extra- 

 cellular water and intracellular water appear in Table III. As 

 expected all values are higher in the males than in the females, 

 corresponding to the higher average weight in the male group. 

 Most of the difference in total body water is accounted for by 

 the difference in intracellular water. 



Table IV 



Body water compartments in adults, relative values 



Sex 

 Males 



Females 



Age 

 23-54 



23-51 



Weight kg. 

 72-5 



59-3 



Water compartments in per cent of body 

 iveight with standard error of the mean 



WW 



TBW 

 54-3 



±1-39 

 48-6 



±1-47 



ECW 



23-4 

 ±0-64 



22-7 

 ±0-54 



30-9 

 ±0-89 



25-9 

 ±0-96 



In Table IV the average values are given in per cent of 

 body weight. The males contain 54-3 per cent of total body 

 water whereas the females contain 48-6 per cent. This dif- 

 ference is statistically significant (P=0-01). The relative 

 values for the extracellular water are very close to one another. 

 The intracellular water amounts to 30 • 9 per cent in the males 

 and to 25 • 9 per cent in the females. This difference is statistic- 

 ally significant (0-01 > P>0-001). 



