674 Ll. €: CHAMBERLIN 
gathering force as the result of the processes in action there. 
The ocean was accumulating carbonates and augmenting their 
degree of bicarbonation with the increase of cold. Now it is 
obvious that if the loading of the ocean with carbonates were 
to proceed to the point of saturation, inorganic processes of 
precipitation and dissociation would come into play to an 
extent that must necessarily balance all further accessions of 
material. It does not appear, however, that there is enough, 
or even nearly enough, carbon dioxide in the air to bring 
about a condition of full saturation of the ocean with bicarbon- 
ates, even if it were all to take that form, and were to be con- 
veyed completely to the sea. But the movement toward satura- 
tion should increase in some degree, probably small, the 
efficiency of inorganic agencies tending toward precipitation, 
although it could become notably effective only after prolonged 
accumulation. 
The concentration of carbonates in the ocean was somewhat 
aided by the removal of water required to form the great ice- 
sheets. Ona rather large estimate of the mass of the ice-sheets, 
this extraction might possibly reach 5 per cent. of the volume 
of the ocean. 
There would probably be a progressive evolution of lme- 
secreting life adapted to the cooled waters, and this would 
increase the rate of carbonic release and contribute to a reversal 
of action. 
None of these subsidiary agencies, nor all combined, seem 
to have been controlling factors. 
It is notable that some of these subsidiary agencies, on 
both sides, are final in themselves and quite without retroactive 
possibilities. When once their work was done there was no 
resilience. It was quite otherwise with the ice mantling and the 
ocean loading. Far from being final, these contained in them- 
selves the potentialities of reaction and gave vigor to the reac- 
tion when it took place. 
Agencies that precipitated reaction—When once the reactive 
agencies had reversed the relative rates of enrichment and 
