Adkniov, Lkonaiji), and RrcHAi{DS()N — Aeration of Water. 23 



salt, at any time during re-aeration were expressed in percentages of satnrat.ion, 

 they would be found to increase practically in tlie same proportions at diflerent 

 temperatures, provided that tlie variation in temperature did not exceed three or 

 four degrees centigrade. 



This view was based upon the following considerations : — 

 (1; Dittmar has determined the saturation values of distilled and of sea-water 

 for atmospheric nitrogen and oxj'geu between 4° C. and So" C. ; and when his 

 results are plotted against temperatures, the cur\'es obtained approximate to 

 parallel straiglit lines between the limits 8^ C. and 35° C/ 



(2) Adeney and Becker, in their worlc on the rate of solution of these 

 atmospheric gases by distilled and by sea-water, found that, when tlie experi- 

 r.iental observations hoxw zero to saturation were expressed as percentages of 

 satitralion and plotted against time, tlie curves obtained were coincident when 

 uniform conditions of exposure of water to the gas, of the mixing of the exposed 

 with the unexposed portions of the water, and of temperature (within 1° 0.) 

 obtained. - 



It may be assumed from this that the curves showing the rate of solution of 

 atmospheric nitrogen and oxygen by dilutions of sea-water with varying propor- 

 tions of distilled water would also be coincident with the curves showing the 

 same for distilled and sea-water, separately, under like conditions of exposure to 

 air, of mixing, and of temperature varying within 1° C. 



(3) Adeney and Becker further found that the cuives showing the rate of 

 solution in water of nitrogen and of oxygen, when stated in percentages of saturation, 

 lie very closely together for differences of 5° (J. within the range of temperature 

 from 0° C. to 30° (J. 



Consequently it is possible to convert approximately, by simple calculation, 

 observations made at slightly different temperatures, to those that would obtain 

 at a selected common temperature, varying even to as much as 2 or 3 degrees 

 from' them, and still obtain sufficiently accurate results for purposes of com- 

 parison. 



'- Supplementary vol. vi to the Fifth Report, Royal Commission on Sewage Disposal, p. 59. 



■• '• The Determination of the Rate of Solution of Atmospheric Nitrogen and Oxygen by 

 Water." By W. E. Adeney and H. G. Becker, Part 1, Sci. Proc. R.D.S., 1918, and Phil. 

 Mag. , 1920, p. 385. 



[Table. 



