666 GEOLOGY. 



a new state of equilibrium. 1 The equalizing supply doubtless comes primarily 

 from the free carbon dioxide or carbonic acid of the ocean, but the reduction 

 which these thereby suffer causes the water to absorb some of the feebly com- 

 bined carbon dioxide of the bicarbonates, while it is temporarily dissociated, thus 

 reducing the bicarbonates to monocarbonates. In the case of calcium carbon- 

 ate, this tends toward precipitation because of its slight solubility. In the opinion 

 of some chemists, this process may go so far, if the atmospheric carbon dioxide 

 is continually removed, as to call forth all the loose carbon dioxide of the bicar- 

 bonates of the ocean, and reduce them to monocarbonates, the calcium mono- 

 carbonate being precipitated, which involves the proposition that all the bicar- 

 bonates of the ocean are held there practically by the carbon dioxide of 

 the air. Without accepting or rejecting this extreme proposition until experi- 

 ments have gone farther and become more consistent, the more conservative 

 observation that there is an interchange in the direction of equilibrium may 

 be recognized as an important working factor. 



The influence of the rate of diffusion. — But it is necessary to take careful 

 note of the qualifying conditions and retarding agencies. The re-establishment 

 of a state of equilibrium after it has been disturbed is dependent on diffusion 

 and on mechanical mixture. If, for example, the air were robbed of one half 

 its carbon dioxide, the ocean having, we will assume, 25 times as much, either 

 in simple solution or in loose combination as the second equivalent of the bicar- 

 bonates, and remaining perfectly quiescent, the ocean would, by theory, ultimately 

 give up enough carbon dioxide to make good about f f of the air's loss, and a 

 new equilibrium would be instituted. To reduce the carbon dioxide of the air 

 one half permanently, about one half of the great store in the ocean must be 



1 The important conception of equilibrium was long since entertained by Schlcesing 

 in its simple theoretical application to the existing status (Sur la Constance de la 

 proportion d'acide carbonique dans Fair, Comp. Rend., 1880, t. 90, p. 1410), and 

 he regarded the ocean as a regulating reservoir, so to speak, restraining the fluctua- 

 tions of the carbon dioxide of the air. This was a very valuable contribution, but 

 in its secular application to geological problems, it must be recognized that all the 

 factors are subject to change and, with them, the basis of equilibrium itself, and that 

 the results are qualified by rates of diffusion, areas of contact, temperatures, and 

 other elements. (See The influence of great epochs of limestone formation on 

 the constitution of the atmosphere, Chamberlin, Jour. Geol., Vol. VI, pp. 609-621, 1898. 

 A group of hypotheses bearing on climatic changes, Jour. Geol., Vol. V, pp. 653-683, 

 idem. An attempt to frame a working hypothesis of the cause of glacial periods 

 on an atmospheric basis, Jour. Geol., Vol. VII, pp. 545-584, 667-685, 757-787, 1899, 

 idem; and also Tolman, The carbon dioxide of the ocean and its relation to the carbon 

 dioxide of the atmosphere, Jour. Geol., Vol. VII, pp. 585-616, 1899.) 



Krogh has recently made valuable contributions to Schlcesing' s conception, but 

 without adequate recognition of the qualifying and secular factors of the problem. 

 (On the tension of carbonic acid in natural waters and especially in the sea, Vol. XXVI 

 1904, pp. 334-405, Meddelelser om Gronland, and The abnormal C0 2 -percentage in 

 the air in Greenland and the general relations between atmospheric and oceanic car- 

 bonic acid. Idem, pp. 409-436.) 



