CARBONIC ACID 



135 



tons for the whole earth. 1 In the oeean the 

 amount of carbonic acid is about 0.1 gram per 

 liter, or approximately 0.01 per cenl by 

 weight. Here, however, much (lie larger 

 part is in chemical union with bases, chiefly 

 in the form of bicarbonates.- 



There can be no doubt that the physical 

 properties of carbon dioxide are less important 

 to the living organism than are those of water. 

 But indeed the characteristics of water so 

 largely determine the nature of the environ- 



1 The composition of dry air is as follows : — 



Per Cubic Meter 



Nitrogen . . 

 Oxygen . . 

 Argon . . . 

 Carbon dioxide 



Nitrogen . . 

 Oxygen . . 

 Argon . . . 

 Carbon dioxide 



2 See below in the discussion of the alkalinity of the ocean. 



