236 AN ANALYSIS 
was found that the precipitate gives no effervescence with mu- 
riatic acid, nor suffers any change. It was therefore sulphate 
of barytes. Dried by a low red heat, it weighed 43 grains, 
equivalent to 14.4 sulphuric acid. 
By this step the whole salts in the sea-water were convert- 
ed into muriates. It remained to discover and estimate the 
quantities of their bases. 
To the clear liquor, oxalate of ammonia was added as long 
as any turbid appearance was produced. ‘The precipitate, 
washed and dried, by a heat of 150° continued for two hours, 
weighed 8.5 grains. Calcined with a low red-heat, it gave of 
carbonate of lime 5.2 grains. This, dissolved with strong ef- 
fervescence in dilute muriatic acid, and the product being 
heated with sulphuric acid, gave sulphate of lime, which, af- 
ter exposure to a red-heat, weighed 7 grains, equivalent to 2.9 
of pure lime. ; 
To the clear liquor warmed, carbonate of ammonia was add- 
ed, and phosphoric acid was dropped in * ; an abundant preci- 
pitation took place of phosphate of magnesia and ammonia, 
and additional portions of the phosphoric acid, with such addi- 
tions of the carbonate as were necessary to preserve an excess 
of ammonia in the liquor, were added, as long as any precipi- 
tation was produced. The precipitate was converted, by cal- 
cination for an hour at a red-heat, into phosphate of mag- 
nesia. This weighed 37 grains, equivalent to 14.8 grains 
of magnesia. 
The clear liquor was evaporated to dryness, and the dry 
mass was exposed to a heat gradually raised to redness, to ex- 
pel the muriate of ammonia formed in the preceding opera- 
tions. 
® J shall have to state in a subsequent paper, the peculiar advantages attend- 
ing this method of estimating the magnesia, 
