CARBON DIOXIDE OF THE OCEAN 607 
an average of 10° C., and the diminution of the partial pres- 
sure he has postulated as sufficient to cause this drop in temper- 
ature. 
We find from Professor Ditmar’s investigation (see tables and 
figures, pp. 609 and 610) that as the waters of the ocean become 
warmer, the effect of a change in the partial pressure of atmos- 
pheric CO, upon the bicarbonate dissociation becomes greater, 
while near zero a change in partial pressure has no effect on 
the dissociation of the bicarbonates of the ocean. On the 
Sa 
6 
# & 
Volume dissolved. 
0 h y z s 
Fics. 3 and 4 show the relation between the partial pressure of CO, and its solu- 
bility in pure water on the one hand and the solubility of Ca Hy (CO3), on the other. 
Fic. 3 represents the simple law of gas absorption that the amount dissolved is 
directly proportional to the partial pressure. The pressure is plotted on the ordinates 
in mm of mercury and the volume of gas absorbed on the abscissa. 
other hand, the effect of any postulated fall in temperature, 
causing the bicarbonates to take up COg, is the greatest at the 
temperature just above 0°, and becomes less for higher temper- 
atures. So that a fall in temperature of the colder waters of 
the ocean is correlated with the greatest absorption of CO,, and 
without the counteracting effect of decreasing partial pressure. 
In equatorial waters, however, the fall in temperature does not 
