CARBON DIOXIDE OF THE OCEAN 601 
according to the laws of gas absorption; this it is to be noted, 
under the unrealizable conditions of a uniform temperature of 
o° C. and an average depth of three miles. But Mr. Buchanan 
found that on boiling, sea water gives an average 45™8 or 23% 
CO, per liter, or ten times the greatest amount the ocean could 
hold as a gas under more favorable conditions than those of the 
present time. Mr. Jacobson found go™s upon distilling the water 
to dryness. Mr. Buchanan thought that this great excess of 
CO, over that which could remain in solution under atmospheric 
pressure of CO, must be held in some sort of loose combination 
with one of the salts, and he decided upon the sulphates as the 
retaining agent. Such a misinterpretation, of course, might be 
expected at that time from the imperfect knowledge of the 
nature of the solutions. Before determining the free CO,, there- 
fore, he precipitated the sulphate with barium chloride, and 
unfortunately he must have obtained a mixture of Ba SO, and 
Ba CO,, so that his numerous determinations are all probably 
somewhat too small. 
But in spite of this his analyses show that the ocean contains 
about eighteen times the CO, of the atmosphere. Now, bear- 
ing in mind Professor Arrhenius’ statement, ‘‘that to lower the 
temperature of the temperate region 5°, and bring on glaciation, 
the CO, of the atmosphere needs to be diminished to from 62 
per cent. to 55 per cent. of its present value,’* the following 
questions suggest themselves : 
1. How is the excess of the CO, found in the ocean at the 
present time held in solution ? 
2. Is it in equilibrium with that of the air? 
3. If so, what proportion of the ocean gas will be brought 
out into the air by a diminution of the partial pressure of the 
CO, to an amount from 62 per cent. to 55 percent. of its present 
value? 
4. How much will the consequent fall of temperature 
increase the ocean’s capacity for CO, ? 
5. What is the relation between these two? 
PWocscit. pp:237—270: 
