100 Hydrographical Observations, North Atlantic, 1903 and 1904 



nitrogen in this sample might he supposed to be about 14-40 c.c. per 

 litre. The nitrogen that has come into the tube from the atmosphere 

 then amounts to 19*79 — 14 - 40 = 5*39 c.c. per litre, and the oxygen 

 may be calculated at 1*43 c.c. per litre (air = 79 per cent. N 2 , 21 per 

 cent. 2 ). The water sample should have 14'40 c.c. N 2 , 5"94 c.c. O a , 

 29*17 per cent. 2 .' 



Column 8 of the table gives the temperature in situ of the sample 

 (Table III.), and column 9 the temperature of saturation calculated 

 from the amount of nitrogen by a graphical extension of Hamberg's 

 table. These values of T, which do not profess to be more than 

 approximations, are of great interest, but their number is too small to 

 justify full discussion. 



Two points arise out of these analyses. The large amount of 

 carbonic acid in the deeper Mediterranean waters is very remarkable, 

 for, as Professor Pettersson has pointed out to me, in the Scandinavian 

 fjords the amount of C0 2 per litre never exceeds 50 to 51 c.c. even if 

 the oxygen has been reduced by the action of animal life to 4 or 5 per 

 cent, of the normal. Yet it is suggested that these Mediterranean 

 waters are of Atlantic origin. The second point is the occurrence of 

 a minimum of oxygen in the Atlantic at a depth of 500 to 600 fathoms. 

 This confirms the results of the temperature and salinity observations, 

 and suggests that in this particular case at least the method of gas 

 analysis is the most sensitive. It seems well to defer further dis- 

 cussion until the observations of Dr. Wolfenden's 1905 cruises are 

 available. 



As has been stated, the soundings may be conveniently grouped in 

 a series of sections. The stations in each section are as follows : 





1903. 





Section I. ... 



... Stations F3, F9, Sc. 19a, Sc. 15a. 



„ II. ... 



., 



F4. F9, Sc. 19a, Sc. 15a. 



„ III. ... 



,, 



F5, F4, F3, F2, Fl. 



„ IV. ... 



,, 



F7, F8, F9. 



V. ... 



,, 



E15, E16. 



„ VI. ... 



,, 



E15, Ell, E13, E12, Ell 

 E10, E9, E8, E7, E5. 



