220 AN ANALYSIS 



cohol. These liquors, poured off from a portion which remain- 

 ed undissolved, were evaporated to dryness ; the dry mass was 

 dissolved in water, and, by a second evaporation, afforded a 

 congeries of prisms of Muriate of Magnesia. Dried by a heat 

 of 150°, the weight amounted to 156 grains. Converted into 

 sulphate of magnesia by the addition of sulphuric acid, the 

 product weighed, after being dried at a low red-heat, 99.2 

 grains, equivalent to 78.4 of real muriate of magnesia. 



H. The matter which remained undissolved by the alcohol 

 G was dissolved in distilled water. The solution was evapo- 

 rated, until, by a farther spontaneous evaporation in a warm 

 apartment, crystals were successively formed ; these were sul- 

 phate of magnesia, and, in general, bevelled prisms. The 

 whole freed from moisture weighed 48.6 grains. A small por- 

 tion of liquor remained, which, when evaporated, gave a deli- 

 quescent saline mass : by slow evaporation 2.6 grains of muri- 

 ate of soda were obtained from it ; the remainder yielded mu- 

 riate of magnesia equal to 3 grains. 



I. The crystals of sulphate of magnesia obtained by the 

 successive evaporations, were not all equally well formed ; and 

 after they had been left exposed to a dry air for some time, 

 some of them became quite efflorescent, while others did not. 

 The former were picked out, and each portion was re-dissolved 

 in water. By a new crystallization, there were thus obtained 

 72 grains of sulphate of magnesia, and 18.5 of sulphate of 

 soda. 



K. The muriate of soda obtained in the preceding steps, 

 amounted in all to 759.6 grains. After exposure to a red- 

 heat, it weighed 752.4 grains. It has already been stated, 

 that it was not perfectly pure; its solution being rendered 

 milky, both by sub-carbonate of soda and muriate of barytes. 

 The separation of the sulphate of magnesia, which this chiefly 



indicated, 



