—— 4.7" 
SPIER IE OE  e T 
4 ee 
OF. SEAWATER. 213 
Ajsmall portion of liquor remained, which, by farther: evapora- 
tion, yielded crystals of ‘sulphate’ of soda‘ to: the: amount of 6 
grains, with crystals‘of muriate of soda 2 grains. 
The portions of muriate of soda obtained in the deseditn 
experiments amounted’ to’ 765.1 grains... None of them; how- 
ever, were perfectly | pure. ° Their solutions became turbid om 
the addition of sub-carbonate of soda, and of muriate of ba- 
_ rytes, indicating the presence of sulphate of magnesia, or of 
muriate of magnesia and sulphate of soda, and probably. indeed 
of portions of all these. “The whole was submitted to the ac- 
tion of highly rectified alcohol for 12 hours, with repeated agi- 
tation ; the alcohol acquired-a bitter taste ; being poured off, 
and distilled, it afforded muriate of magnesia, which, heated 
with sulphuric acid, gave a product equivalent to 6.2‘of real 
muriate. The residual salt still gave indications of the pre- 
sence of sulphate of magnesia, by the tests of muriate of ba- 
rytes and sub-carbonate of soda. The difficulty is so great, of 
separating a small portion of a salt from a large quantity of 
another, where the difference in their solubility is not consider- 
able, that instead of attempting to remove the sulphate of mag- 
nesia by farther crystallizations, it was decomposed by adding 
to the solution sub-carbonate of soda; the precipitate was col- 
lected, and converted into sulphate of magnesia by the addition 
of sulphuric acid. This, dried ata low red-heat, weighed 16 
grains, equivalent to 33 crystallised. The salt had been previ- 
ously exposed to a red-heat, when it weighed 744.5 grains. 
The above quantity of sulphate abstracted from this, leaves as 
the real quantity of muriate of soda 728.5 grains. 
The powder G was soft, light, and tasteless. It weighed 
when thoroughly dried 7.5 grains." It might be expected to be 
similar to the powder A, and was therefore subjected-to the 
same treatment. Diluted alcohol, acidulated with muriatic 
acid, 
