430 



ordinary air that its influence cannot be detected by the 



analyses M- 



As shown in the preceding paper the soil of Disko does 

 not contain free carbonic acid or, at all events, the tension of 

 the gas is distinctly lower than in the atmosphere, owing to the 

 alkaline nature of the rocks. The freshwaters, likewise, absorb 

 carbonic acid from the atmosphere instead of liberating it. 



In many places, throughout Europe and elsewhere, carbonic 

 acid issues forth from the depth in considerable quantities, 

 which must be detectable by analyses of the atmosphere in the 

 environs of such springs. 



In Arctic countries, however, the deep layers of the ground 

 are separated from the surface by an enormous sheet of frozen 

 rock, which must generally be impermeable for the gases below. 

 A few springs of hot water find their way through it, but even 

 if these were saturated with carbonic acid, the amount of gas 

 liberated would be too small to be detectable by analyses of the 

 atmosphere. My investigations show, further, that the hot 

 springs of Disko do not contain free carbonic acid. 



It appears from the above that the cause of the high 

 percentage of carbonic acid, observed in the air of Disko. is 

 not to be found on land. We must therefore turn our attention 

 to the sea. 



3. Reasons have been given above for the contention that 

 the COg-tension of the ocean-surface is generally lower than 

 that of the atmosphere, but, notwithstanding this, it may very 

 well be considerably higher in some places. 



In the bottom-water of the Baltic I found a tension of 

 carbonic acid of about 0.16 ^/o (see preceding paper p. 389), 



') The high percentage of CO.^, often observed during fogs, is ascribed by 

 Palmquist to the elimination of gas from the ground. It is supposed 

 by this Author that the carbonic acid cannot, under such circumstances, 

 be so rapidly dispersed. 



