Solution of Atmospheric Nitrogen and Oxygen by Water. 333 



The results o£ the experiments show that the bubble of air 

 in passing* up the tube continually exposed fresh water- 

 snrface to the air, and at the same time kept the water 

 mixed. In order to confirm this view, a test experiment 

 was made with a tube 5 feet long. This was filled in the 

 ordinary way, and the inversions carried out until the air- 

 content was about 60-70 per cent, of saturation. The water 

 in the tube was then drawn into the pump in two equal 

 portions, each of which was analysed separately. One of the 

 analyses represents the air-content of the water in the upper 

 halt' of the tube, and the other that in the lower half. 



Upper half. Lower half. 



C0 2 0-099 c.c. 0-075 c.c. 



Oo 0-235 c.c. 0-247 c.c. 



N 2 0-442 c.c. 0-466 c.c. 



Totals 0-776 c.c. 0'788 c.c. 



These figures show that the difference in air-content between 

 any one portion of the water in the tube and any other is not 

 appreciable on analysis; hence the assumption that the water 

 is well mixed seems to be a reasonable one. 



In order to keep a check on the manometer readings, 

 the air-content of the water was determined after each ex- 

 periment by boiling out in vacuo and measuring the gases, 

 using the apparatus described above. A comparison of 

 i he results obtained by the different methods is given in 

 Table 4. 



The area of the surface of the bubble was calculated from 

 the measurements of its length when at rest and in motion 

 and the known internal diameter of the tube. 



The volume of the bubble was 15 c.c. Its length when in 

 motion was 16*04 cm., and when at rest 13*30 cm. The 

 diameter of the tube was 1*20 cm.; hence its sectional area 

 Avas 1*13 sq. cm. 



The total volume of the water supported around the bubble 

 was the amount which collected when the bubble burst. 

 i. e . =(16*04-13-3) 1*13 c.c. = 3*10 c.c. 



This volume is made up of the portion round the 

 hemispherical cap of the bubble and the cylindrical shell 

 below. 



Phil. Mag. S, 6. Vol. 38. No. 225. Sept. 1919. 2 A 



