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. 



• I shall have to state in a subsequent paper, the peculiar advantages attend- 

 ing this method of estimating the magnesia. 



