CARBON DIOXIDE OF THE OCEAN 595 
cules. From some of his tables we find that for a solution of 
the strength of the oceanic brine the diminution of the solubility 
for gases of this class is somewhere near 20 per cent. (Joc. cit. 
PP: 245-259). 
If, however, there is a chemical reaction between the gas and 
the salt, the solubility is increased by so much. Oxygen, nitro- 
gen, and argon do not react with the salts of the ocean, but 
COG does, The carbonic acid dissociates into its ions, and 
these ions react with the ions of the salts to form small quanti- 
ties of undissociated compounds. This reaction has an appreci- 
able effect only where the original salt is formed from weak 
acids and bases. From Mr. Setchenow’s tables* for Na Cl 
solution of the strength of the sea water we gather that this 
increase for CO, would not be over 20 per cent. of that dissolved 
by pure water (.3” per liter, a quantity wholly negligible). 
The ocean salts.,—The average temperature of the surface of 
the ocean is about 15°C. 
The proportion of the different salts in the ocean, Professor 
Dittmar finds to be wonderfully constant for all parts of the sea 
water. He gives the following analysis for the salt : 
Gl, = - - - - - 5 5.292% 
Br - - - - - - .1884 
5SOz - - - - - 6.410 
COs = - - - - - .152 
CaO - - - - - 1.676 
MgO - - - - - - 6.200 
K,0 - - - - - 1agQ2 
Na,O - - - - - 41.234 
Basic O (equivalent to Hologen) —12.493 
100 
This table we have recalculated for the percentages of the 
ions according to modern usage, and in order to facilitate subse- 
quent discussion, as follows : 
mIcoe. cit.p. 240: 
? Phys. Chem. Chall. Exp., Vol. I. Narrative of the Cruise of H. M. S. Chal- 
lenger, 1885; Ency. Brit. XXI, pp. 611 to 614. 
