GEOLOGY — CHAMBERLIN. 183 



Under the general conditions of depletion and supply dependent 

 on deformation and vulcanism, the earth maintains a system of 

 storage and free delivery which effectually abets these primal agen- 

 cies in the maintenance of a serviceable working mean, viewed from 

 the standpoint of life, while it incidentally develops oscillations of 

 its own. This storage agency is found in the ocean, and a special 

 feature of the work of the year has consisted of a study of the 

 function of the ocean as an atmospheric reservoir and regulator, 

 particularly its action in the absorption and release of carbon dioxide. 

 Besides the climatic relations of this study, it considered the sources 

 of such large supplies of carbon dioxide as went to form the limestones 

 and other carbonates, together with the coals and other carbonaceous 

 deposits, and the consistency of such supplies with an atmosphere 

 not too highly carbonated to permit a continuance of active life on 

 land and sea. The testimony of the life record seems to indicate that 

 the variation of carbon dioxide in the atmosphere, while it may 

 have been considerable, was never very profoundly greater nor very 

 profoundly less than that of the present time, if by this expression 

 is understood a supply never many times greater nor many times 

 less than the existing quantity. The subject in its totality is too 

 complex for fair presentation here and only a few salient features 

 will be touched. 



The function of the ocean as a reservoir of atmospheric materials 

 has been for some time recognized by special students of the sub- 

 ject, but its working methods have not been elaborated and some 

 serious misapprehensions of its effects have been entertained. The 

 ocean carries carbon dioxide not only by absorption as carbonic acid, 

 but also in combination as the acid element of carbonates and bicar- 

 bonates, from all of which, under certain conditions, it may be sep- 

 arated and given forth into the atmosphere. While held in the 

 combined state it is essentially innocuous to animal life. The ocean 

 may thus hav^e held within itself, in a condition harmless to life, 60 

 or 80, or possibly 100, times the amount of carbon dioxide now con- 

 tained in the atmosphere ; while, on the other hand, it may have 

 been so far depleted by the removal of its carbonates as to contain 

 but a small multiple of the atmospheric content. My studies lead 

 to the belief that this variation could have taken place without 

 necessarily involving corresponding fluctuations in the atmospheric 

 content, for while a certain equilibrium must be assumed to have 

 existed between the carbon dioxide of the atmosphere and that of 

 the ocean, the basis of equilibrium was susceptible of very wide 

 changes by the increase or diminution of the carbonates of the ocean. 



