ke et oe 
OY SEA-WATER. 243 
to the end of it, and the muriate of soda would be depo- 
sited in the same manner ; so that the proportion between the 
two would continue nearly the same, But if the sulphate of 
lime did not exist in solution, but derives its origin from the 
action of sulphate of soda on muriate of lime, which these 
brines contain, this action would take place, when a certain 
degree of concentration of the liquor had been attained; the 
sulphate of lime would then be copiously deposited ; but as 
the evaporation continued to proceed, its quantity would be di- 
minished, as the quantity either of sulphate of soda, or of mu- 
riate of lime, became less; and its deposition would cease 
when either of these salts was exhausted. 
This is placed in a still clearer light, by an analysis of these 
brines, after evaporation, to a certain extent, compared with 
their original composition. A brine from Northwich was 
found by Dr Henry to afford, by evaporation, saline matter, 
which, he inferred, contained in 1000 parts, muriate of lime 
and muriate of magnesia in nearly equal proportions 5 parts, 
sulphate of lime 19 parts, muriate of soda 974 parts. But the 
brine remaining after the separation of all the common salt, 
which it is thought worth while to extract, afforded saline mat- 
ter by evaporation, which he found to contain, in 1000 parts, 
muriate of magnesia 35, muriate of lime 32, sulphate of lime 6, 
muriate of soda 927. Here, in the progress of the evapora- 
tion, the quantity of sulphate of soda, which may be consider- 
ed as an original ingredient of the brine, had been diminished 
by the decomposition arising from its action on the muriate of 
lime. The liquor, therefore, after this, afforded by farther 
evaporation, along with a large quantity of muriate of lime, a 
small quantity only of sulphate of lime ; while, if this sulphate 
had been an original ingredient, it would have continued to be 
afforded at least in equal proportion. 
Hh 2 Something 
