Aprney— Unrecognised Factors in the Transmission of Gases through Water. 1638 
DESCRIPTION AND RESULTS OF EXPERIMENTS. 
Eaperiments with unbroken Surfaces. 
No. 1. Two tubes, each 1950 mm. long and 18min. bore, were filled to the height of 
1800 mm. from the bottom, one with sea-water, and one with distilled water, both being 
nearly nitrogen-free, and were tmmersed in the water-yacket, and kept undisturbed for 
twenty-eight days. The temperature of the room varied between 16°5° and 10° C., that of 
the jacket between 12°9° and 8:0°C. During the last week of the experiment the 
temperature of the room varied between 12° and 10° C., and that of the jacket between 9° 
and 8° C. 
Distilled water saturated at 10° C. contains 15:37 cc. N, per litre.  Sea-water 
saturated at 10° C. contains 12°47 ce. Ny per litre. 
Depth of layer below surface. Sea-water. Distilled water. 
1 to 200 mm. O ar: 9°24 06 5.0 11°50 
300 to 500 mm. ae 50 8:96 50 5c 11-10 
800 to 1000 mm. 50 0.0 8°91 ie 00 8°43 
1600 to 1800 mm. Gye o6 7°89 56 50 6°84 
Before aération .. 6 1°51 6 50 1°55 
No. 2.—Similar to No. 1, with the exception that the tubes were kept longer in the 
water-jacket, viz., for 24 months. Temp. of room at close of experiment, 17-8°; of the 
water-jacket, 15:°6° C. Distilled water at 17-°8° C. contains 13°29 ce. Ny per litre; sea- 
water at 17°8° C. contains 10°80 ce. Ny per litre. 
1 to 200 mm. at 10°80 at 12°56 
1600 to 1800 mm. ait 10°72 hoe 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-water 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-water and distilled water in No. 1, 
even after exposure to the air for twenty-eight days, did not become saturated with 
nitrogen. Hence we may conclude that the streaming effect is more rapid in both 
sea-water and distilled water than the rate of solution at the surface exposed to the 
alr. 
These experiments, so far as they go, may be regarded as supporting the 
suggestion of Hiifner, that the streaming is a gravitational effect due to 
concentration currents. ‘The following experiment, however, affords conclusive 
evidence 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 
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