OF SEA-WATEK. 219 



valent to 4.3 of carbonate of magnesia, and 3 of sulphate, 

 equivalent to 2.2 of carbonate of lime. I have already obser- 

 ved, however, that no carbonic acid is detected in sea-water by 

 the test of barytes ; these carbonates, therefore, are, as before, 

 to be considered as products of the evaporation, arising from 

 the decomposition of muriate of magnesia, and of muriate or 

 sulphate of lime. The one, but for the decomposition by 

 which it is produced, would have appeared as sulphate of lime ; 

 it increases, therefore, the proportion of that ingredient to 29.8 

 grains. The portion of muriate, equivalent to the other, that 

 is, 4.4 grains, may be added to the quantity of that salt obtain- 

 ed in the subsequent steps of the analysis. 



F. The products of the different crystallizations B, con- 

 sisting chiefly of sulphate of magnesia, with portions of mu- 

 riate of magnesia, were left exposed to the air for some days, 

 and the liquor formed from them by deliquescence, was pour- 

 ed off occasionally, and added to the solution of muriate of 

 magnesia, C. The residues were then washed with pure al- 

 cohol, to abstract more completely any muriate of magnesia. 

 The portions remaining undissolved, were dissolved together 

 in water. By evaporation, they afforded sulphate of magnesia 

 in bevelled prisms ; by farther evaporation, muriate of soda in 

 cubes was obtained ; and by successive evaporations, there 

 were thus procured sulphate of magnesia in crystals, 46.6 

 grains ; and muriate of soda 39 grains. A small portion of li- 

 quor remained, which, containing chiefly muriate of magnesia, 

 was added to the liquor C. 



G. This liquor C to which the portion of liquor formed by 

 deliquescence from B, had also been added, was evaporated 

 to dryness. It was then submitted to the action of successive 

 portions of alcohol, employing, first, the alcohol with which 

 the saline matter B had been lixiviated, and afterwards pure al- 



E e 2 cohol. 



