Transmission of Gases through Water. 363 



Distilled water saturated ao 10° C. contains 15*37 c.c. 

 N 3 per litre. Sea-water saturated at 10° C. contains 

 12-47 c.c. X 2 per litre. 



Depth of Layer 



below surface. Sea-water. Distilled water. 



1 to 200 mm 9'24 11-50 



300 to 500 ., sin; n-io 



800 to 1000 , 8-91 8-43 



1600 to 1800 ., 7-8D 5*84 



Before aeration 1*51 1*55 



N >. 2. — Similar to No. 1 with the exception that the tubes 

 were kept longer in the water-jacket, viz. for 2^ months. 

 Temperature of room at close of experiment 17°*8 C, of 

 water-jacket 15°'6 C. 



Distilled water, at 17°'8C. contains 13'29 c.c. N 2 per litre. 

 Sea-water at 17°-8 C. contains 10*80 c.c. N 2 per litre. 



Depth of Layer 



below surface. Sea-water. Distilled water. 



1 to 200 mm 10*80 12-56 



1600 to 1800 „ 10*72 9-09 



The foregoing results reveal a number of points of interest 

 in connexion with the streaming effect above referred to. 



The most noticeable is the marked difference in rate in 

 sea- and distilled water, being much greater in the former 

 than in the latter. Another point of interest is that the 

 surface-layers of the sea- and distilled water, in No. 1, even 

 after exposure to the air for 28 days, did not become satu- 

 rated with nitrogen. Hence we may conclude that the 

 streaming effect is more rapid in both sea- and distilled water 

 than the rate of solution at the surface exposed to the air. 



These experiments, to far as they go, may be regarded 

 as supporting the suggestion of Hiiiher, that the streaming- 

 is a gravitational effect due to concentrated solution currents. 

 The following experiment, however, affords conclusive evi- 

 dence that the streaming is really a gravitational effect. 



No. 3. — A U-shaped tube, each limb 1600 mm. long and 

 50 mm. diameter, was filled with boiling sea-water and 

 immediately closed air-light with indiarubber corks. 

 When the water had cooled, the tube was further ex- 

 hausted by mean- of a mercury-pump. One limb was 

 then uncorked, and the water in it was saturated with 

 atmospheric gases by a current of air drawn through the 



