Lerts & Braku— The Carbonic Anhydride of the Atmosphere. 161 
(apports des fleuves). The equilibrium cannot be realised absolutely, 
as perfect equilibrium is not compatible with either atmospheric 
or ocean currents. Continuous exchanges ought to occur between 
the two media, provoking either disengagement of carbonic anhy- 
dride from sea-water, and consequent precipitation of carbonate of 
calcium (diminution in tension of atmospheric carbonic anhydride), 
or absorption of carbonic anhydride, and consequent solution of car- 
bonate of calcium (increase in tension of atmospheric carbonic 
anhydride).”’ 
Schloesing then calculates the respective quantities of marine 
and aerial carbonic anhydride on the basis (1) of his determination 
of the amount of the gas in sea-water, and (2) that air contains on an 
average three volumes in 10,000, and comes to the conclusion that 
“the oceans hold in reserve a disposable quantity of carbonio 
anhydride, for exchanges with air, ten times greater than the total 
quantity contained in the atmosphere, and a fortiori very much 
larger than the variations in this quantity.”! 
Schloesing’s theory is certainly ingenious, but it seems to us 
that it requires further investigation and is open to criticism. For 
instance, according to it, ought not the air of the tropics to be 
richer in carbonic anhydride than that of Polar regions, and ought 
not great ocean currents like the Gulf Stream to exercise a per- 
ceptible absorbing action as they pass from warmer to colder 
regions, leaving the atmosphere poorer in carbonic anhydride? 
But no such effects have been observed with certainty.” Hven 
allowing that in the main Schilcesing is correct, oceans would at 
best only exercise a limited action as regulators, for suppose a 
gradual but constant source of increase in the amount of atmos- 
pherie carbonic anhydride to exist, oceans would only partially 
diminish it, and a gradual but perceptible increase would still 
occur. 
1<¢Tt is admitted,” he says, ‘‘ that the sea, if spread over the whole surface of the 
globe, would have a depth of 1000 metres. The quantity of carbonic anhydride con- 
tained in a vertical prism cf this layer having 1 square metre for a base is 98°38 kilos, 
forming bicarbonates: the half is 49 kilos, and this is the quantity disposable for the 
regulating action, the other half being retained by the bases. In supposing that our 
atmosphere has a uniform composition, and contains z5%pq of its volume of carbonic 
anhydride—a vertical prism of this atmosphere, having for a base 1 square metre, con- 
tains only 4°7 kilos of carbonic anhydride.”’ 
2 See p. 179. 
