of the Surface Water of the Atlantic and Pacific. 



73 



34.53 (range 32.94 to 35.64). Thus it seems to be absorbing CO2 

 from the air. 



The surface water within 400 miles of the coast of CaUfornia, due 

 to upwelHng of deep water in this region, seems as a whole to be about 

 in balance with the atmosphere, although closer to shore it is doubtless 

 gi\ing out CO2 into the air. Thus, my average for the eight voyages 

 is: Temperature 13.45° C, Ph 8.09, CO2 tension 3 ten-thousandths 

 of an atmosphere, and salinity 33.15. 



We lack sufficient data for a definite statement as to whether CO2 

 is on the whole passing from air to sea, or vice versa, but the surmise 

 may seem reasonable that a balance is maintained; the absorption 

 of CO2 from the air by the Polar Seas being offset by its passing slowly 

 out of the ocean over the wide area of the tropics, at least during 

 the warmer months of the year. The temperate regions, on the other 

 hand, stand in an intermediate relation, the water absorbing CO2 

 during the winter and giving it out to the air during the summer. 



Table (i. 



It may be of interest to compare our observations with those of 

 Palitzsch (1911), who was the first to apply Sorensen's colorimetric 

 methods to the study of the hyrogen-ion concentration of sea-water. 

 Palitzsch used naphtholphthalein and phenolphthalein as indicators 

 and tested the Ph of the Black Sea, Sea of Marmora, Mediterranean, 

 Atlantic, and North Sea in summer, with the results shown in table 6. 



