3G6 Dr. W. E. Adeney on the 



No. 7. — Similar to the experiment No. 6, with the exception 

 that the inlet-tube dipped 10 mm. below the surface in the 

 first column of water, and 100 mm. in the second column. 

 The current of air was continued for 20 hours. Tempe- 

 rature of room at conclusion was 18°*2 C, and of the jacket 

 14°*9 C. 

 Sea-water at 18°*2 C. contains 10*68 c.c. N 2 per litri 



•e. 



Depth of Layer 

 below surface. 1. 2. 



1 to 100 mm 10-07 9*95 



1000 to 1100 „ — 6-05 



1200 to 1300 „ 9-61 — 



1700 to 1800 „ 6-26 2*15 



Before aeration 1*G1 1*56 



The sea- water employed for the experiments thus far re- 

 corded was collected in Dublin Bay. It had been stored 

 in partially full bottles for some weeks previous to use. It 

 contained 19*57 parts chlorine per litre. 



From the foregoing results it appears that the rate of 

 aeration, as a consequence of the streaming, was not materially 

 affected by difference of depth of the air-inlet tubes, when 

 two water-columns were aerated in series by the same current 

 of air. The inlet- tubes dipped 100 mm. and 10 mm. below 

 the surfaces in the columns of water 1 and 2 respectively 

 in experiment No. 6, and vice 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 dis- 

 solved more nitrogen than either of the second columns of 

 water. 



It appears, therefore, from these experiments that some- 

 thing 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 to ascer- 

 taining whether, by using slower currents of air and fine 

 capillaiy 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 nitro- 

 gen-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 mm., one 

 after the other. 



