166 Aprnry—Unrecognised Factors in the Transmission of Gases through Water. 
inlet tubes, when two water-columns were aérated in series by the same current 
of air. The inlet tubes dipped 100 mm. and 10mm. below the surfaces in the 
columns of water 1 and 2, respectively, in experiment No. 6, and wice versa in 
experiment No. 7; and yet both the columns of water which first received the 
air-currents in the two experiments were found to have dissolved more nitrogen 
than either of the second columns of water. 
It appears therefore from these experiments that something was taken from 
the air by the first water-column in each experiment in addition to the ordinary 
atmospheric gases, and that very little reached either of the second columns. 
The next experiments were arranged with a view of ascertaining whether, by 
using slower currents of air and fine capillary glass inlet and exit tubes of 0°5 mm. 
bore, the streaming effect could be completely confined to the first water-column. 
No. 8.—Three tubes, each containing sea-water nearly nitrogen-free, were fitted with 
indiarubber corks and air inlet and exit tubes, and were connected in series, so that the 
same current of air could be drawn through the upper layer of each column of water to a 
depth of 200 min., one after the other. 
The air-current was a slow one, at the rate of about a litre per hour. It was continued for 
forty-eight hours, and then stopped. Samples of water were then drawn from each tube as 
before, and stored in glass vessels standing over mercury. The nitrogen determinations 
are given below. The tube which the air-current first entered was marked 1, and the one 
at next entered 2, and so on. The ar was filtered through glass wool. 
Temperature of room, . 5 IBS? xo OW? C. 
Temperature of jacket, . 86° to 83° C. 
Sea-water at 10° C. contains 12:47 cc. N, per litre. 
Depth of layer. 1 2 3 
1 to 200mm., ob YY 8 MMB. ga AOS 
800 to 1000mm., —.. 8720 ee TO 2°55 
1600 to 1800mm.,_—.... ONG oo Dal Bane: 2°54 
Before aération, OC 1:57 af 2°18 ae 2°51 
No. 9.—Similar to the experiment No. 8, with the exception that the air inlet tubes 
dipped only 50 mm. below the surface. The air-current was filtered through glass wool. 
Temperature of room, 5 UB ti IBS? C. 
Temperature of jacket, . : 8:4° to 8:5°C. 
Sea-water at 13°5° C. contains 11°67 cc. N, per litre. 
Depth of layer, 1 2 3 
1to 200mm., oo. OAS Ml, GOB 
300 to 500mm., Sens 1(0:6 0 re eG | 
800 to 1000 mm., <n 9°36 ets 1°65 O° 1:56 
1600 to 1800 mm., », DAD gd) CK og Te 
Before aération, sts 1:75 AS 1°63 50 1°51 
