372 
Book II. 
Specific 
gravity of 
water hold 
ing diffe 
rent pro 
portions of 
salt in solu 
tion. 
SEA 
and Beaumé obtained by analysis, from water takén up 
by Pages in north latitude 34° and 14° exactly the same 
proportions of saline matter. In southern latitudes 
Pages found the following proportions of saline mat 
ters : 
Saline Matter. 
Latitude. 
49° 50 . . . . . . . . . 0.0416 
46 0. 0.045 
40 30.. ... . 0.04 
25 54 . . . . . . . . . 0.04 
20 0.d3 
I 16....... 0.035 
From the experiments made by Bladh on the specific 
gravity of sea water in different latitudes, it appears that 
the water contains more salt at the tropics than towards 
the equator. 
If we were acquainted with the proportion between 
the saline contents of sea water and its specific gravity, 
it would be easy in all cases to ascertain the quantity of 
saline matter merely by taking the specific gravity of 
the water we wish to examine. This would require a 
set of experiments on purpose ; dissolving in pure wa 
ter different quantities of the salts contained in sea wa 
ter in the proportions which they bear to each other, 
and ascertaining the specific gravity of every such solu 
tion. Dr Watson has given us a Table for ascertain 
ing that point, as far as common salt is concerned; and 
as the salt which he used was not perfectly pure, but 
contained a mixture of the different salts usually found 
in the sea, we may consider it as very nearly determining 
the proportion of saline contents in sea water as far as 
it goes. This TABLE therefore I shall here insert ?. 
* Watson's Chemical Essays, v. 91.