OF SEA-WATER. 239 



Muriate of Soda, - 159,3 grains. 



Magnesia, - 35.5 



Lime, - 5.1 



Sulphate of Soda, - 25.6 



226.1 grains. 



These proportions differ somewhat, though not very mate- 

 rially, from those found by the other modes of analysis. The 

 principal differences consist in the quantity of magnesia, and 

 of sulphuric acid being rather larger. This is evidently to be 

 ascribed to the modes of detecting sulphuric acid by barytes, 

 and magnesia by phosphoric acid and ammonia, being so per- 

 fect, that the entire quantities of them are found ; while, in 

 the other modes, from the difficulty of effecting the entire se- 

 paration of salts from each other, a small portion of sulphate 

 of magnesia, or of muriate of magnesia and sulphate of soda, 

 had remained with the muriate of soda, and though subcarbo- 

 nate of soda was employed to decompose them, this decompo- 

 sition is not altogether perfect. In the mode of analysis, too, 

 by re-agents, the presence of water in the products can be 

 more completely excluded, and to this, probably, is to be a- 

 scribed the absolute quantity of saline matter being a little less 

 according to this analysis, than it is in the others *. 



Of 



* In another analysis of sea-water, in which subcarbonate of ammonia was 

 employed to precipitate the magnesia, a solution of it being added to the water 

 concentrated by evaporation, the clear liquor, after the subsidence of the preci- 

 pitate being evaporated to dryness, the saline matter being exposed to heat, to 

 dissipate the muriate of ammonia ; being re-dissolved in water, the subcarbonate 

 of ammonia again added, and this repeated for a third, and even a fourth time, 

 the results gave the following proportions of the elements, 



Lime, 



