THE ORIGIN OF ORGANIC MATTER 



41 



TABLE 3 

 Gases of the Atmosphere Contained in Fresh and Sea- water. (From Schulz.) 



Nitrogen -\- 



A, in the Atmosphere J J"^'^^^''^- 

 ^ ^ In per cent 



In 1,000 cc. 

 In per cent 

 In 1,000 cc. 

 In per cent 



In 1,000 cc. 



In per cent 



In 1,000 cc. 



^ In per cent 



Nitrogen 

 + Argon 



790 cc. 

 79 



18.64 cc. 

 63 



12.59 cc. 

 65 



per cent \ 



L At 20° 



14.42 

 63 



10.42 

 65 



cc. 



cc. 



Oxygen 



210 cc. 

 21 



10.29 cc. 



35 



6.57 cc. 



34 



8.04 cc. 



35 

 5.36 cc. 



34 



Carbon 

 Dioxide 



0.3 cc. 

 0.03 



0.51 cc. 



1.7 

 0.26 cc. 



1.3 



0.44 cc. 



1.9 

 0.23 cc. 



1.4 



Oxygen -|- 

 Carbon 

 Dioxide 



29.4 cc. 



100 

 19.4 cc. 



100 



22.9 cc. 



100 

 16.0 cc. 



100 



Owing to differences in the solubility of the gases of the atmosphere 

 the ratios of oxygen, nitrogen and carbon dioxide are different in water 

 than in air. The amounts of the gases present in the water are, of course, 

 greatly influenced by temperature, as well as by the salinity; both of these 

 factors vary greatly in different parts of the world. It has been found 

 that in the summer the oxygen content of sea-water at depths of about 20 

 meters is greater than that obtaining with sea-water and air in equilibrium. 

 The explanation offered for this is that during the summer months photo- 

 synthesis by marine plants is in excess of respiration and the oxygen lib- 

 erated during photosynthesis accumulates in the water. At the surface 

 of the sea where there is opportunity for diffusion into the atmosphere. 



TABLE 4 



Increased Oxygen Content of Sea-water Due to Photosynthesis in Summer. 



(From Schulz.) 



"Poseidon." Station 13. 



