The amount of common Salt in all the oceans is estimated by Schafhäutl
at 3,051,342 cubic geographical miles. This would be about five times
more than the mass of the Alps, and only one-third less than that of
the Himalaya. The sulphate of soda equals 633,644·36 cubic miles, or is
equal to the mass of the Alps; the chloride of magnesium, 441,811·80
cubic miles; the lime salts, 109,339·44 cubic miles. The above supposes
the mean depth to be but 300 metres, as estimated by Humboldt.
Admitting, with Laplace, that the mean depth is 1000 metres, which is
more probable, the mass of marine salt will be more than double the
mass of the Himalaya.--_Silliman’s Journal_, No. 16.
Taking the average depth of the ocean at two miles, and its average
saltness at 3½ per cent, it appears that there is salt enough in the
sea to cover to the thickness of one mile an area of 7,000,000 of
square miles. Admit a transfer of such a quantity of matter from an
average of half a mile above to one mile below the sea-level, and
astronomers will show by calculation that it would alter the length of
the day.
These 7,000,000 of cubic miles of crystal salt have not made the sea
any fuller.