416 



found during a strong easterly wind. It must be remembered 

 however that the place lies at the head of a »fjord» sur- 

 rounded on all sides by mountains ; the real direction of the 

 wind outside can therefore have been quite different. All other 

 places mentioned lie on the open sea-shore or so near to the 

 mouths of the «Qords» that the true direction of the wind 

 could always be ascertained. 



On the whole, it seems that Disko lies on the southern 

 or eastern border of an area of intensive production of carbonic 

 acid, since air, rich in the gas, oscillates to and fro over the 

 Island according to the shifting of the wind. What can be 

 the seat and source of this production or liberation of car- 

 bonic acid? 



In order to solve this special question I have been obliged 

 to take up the general problem of the carbonic acid of our 

 atmosphere, and by bringing to bear upon this the principles 

 of the tension of carbonic acid in the sea and of evasion and 

 invasion, as set forth in the preceding paper, I shall be able, 

 I hope, to throw some new light upon certain points in it. 



I. The carbonic acid of the atmosphere as a whole. 



I we take 0.03 as the average percentage of carbonic acid 

 in the air, what is probably a little too high, the total quantity 

 of the gas present in the atmosphere comes out as 2.4 x 10'* 

 tons. Is this quantity a fixed and unalterable one? 



This question has been discussed by several Authors and 

 valuable contributions have been made towards its solution, 

 notably by HoGBOM^) and Chambkrlin^). I shall confine myself 

 to a brief statement of the chief causes of consumption and 

 production of the gas. 



•) Svensk Kemisk Tiäskrift Bd. ö, 1894, p. 1G9. 

 ■'') Joimial of Geolofiy. vol. 7, 1899. 



