T. S. Hunt on Salts from Sea-water, 367 
ture of salts (A) is carefully collected, and resetved for the man- 
d 
- wfacture of the sulphate of soda. 
of the sun, it deposits a mixture which is called sel @été, and 
of 35° or 40° Fahrenheit, they deposit the greater part of their 
sulphate of magnesia in large crystals. This sulphate is either 
sold to the apothecaries, or used to prepare sulphate of soda by 
the process about to be described. When the sulphate of mag- 
n . . . 
taked up from the tables and placed in piles on the earth, where 
the moisture causes the salt to decompose; the magnesian salt 
_. The mother li uors, having acquired a density of 38°, have 
deposited all thebr potash, and oe now evaporated by artificial 
heat to 44° ; during this evaporation they still deposit a portion 
of common salt mixed with sulphate of magnesia (B), and on 
Cooling, the liquid becomes a solid mass of hydrated chlorid of 
_ Magnesium, which may be employed to furnish caustic and car- 
: bonated magnesia by Secompasition. When calcined in & cur- 
«Tent of steam, it is completely decomposed into bydrochiaes 
— *id and an impure magnesia, still contaiming some sulphates an 
‘Worids, which may be removed by water. | vee 
Y mingling in eriged proportions the solution of chlorid of 
Salt is precipitated in the form of minute crystals of eat 
4 Water has become greatly diminished. 10,000 
| rater ° : 
reduced to 25°, see at 30°, 200 gallons; at 31°, 50 
