T. S. Hunt on Salts from Sea-water. 369 
quantity of anhydrous sulphate of soda equal to one-eighth that 
of the common salt, but on a large scale the whole of this can- 
‘ be economically extracted: the saline of Baynas - yields 
_ annually besides 20,000 tons of sea-salt, 1,550 tons of dried sul- 
phate of soda, or 7°75 per cent, instead of the 12°50 per cent indi- 
cated by theory. Estimating the yield at 7-0 per cent the cost 
of the sulphate according to Payen, will be 80 frances the ton, 
which will make the cost of the crude carbonate of soda 5 
francs, while it brings in France from 80 to 120 franes the ton. 
_ The amount of chlorid of potassium obtained is equal to one- 
hundredth, or to 200 tons for the above amount of sea-salt, and 
the value of this salt is 860 francs the ton. By its decomposition 
_ Wtwill yield 185 tons of pure carbonate of potash, which sells 
for 1000 or 1100 francs the ton. Thus it appears that for 20,000 
tons of sea-salt, worth at ten francs the ton, 200,000 francs, there 
1s obtained chlorid of potassium for the value of 72,000 frances. 
‘he potash, being a secondary product from the residues of the 
aa scale in the vicinity of Marseilles, where the marshes of 
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phate of soda at 7 per cent will be 35,000 tons. The amount of 
_ Sulphate of soda annually manufactured in France is 65,000 tons, 
‘quiring for this purpose 54,000 tons of sea-salt, and nearly 
Soda manufactory of Chaunay, established in connection with the glass 
obain, consumes above 5,000 tons of sulphur yearly, and the immense 
ND SERIES Vor. XXV, No. 75.—MAY, 1858. 
47 
