being evaporftteci Id d'^yri^s^, kft a i*esidu^, tvhicfh ^ofTeifed 



the pro|)ert»es of sulphate of lime, and which weighed 1»2 Lime. 



grains, equivalent to ahoutO'7 of a grain of lime. 



10. The constituents obtained by the f>rec^ding analysis Analysed in a 

 Leins^ obviously defective, it remained to examine whether *^'^^^'*^^^ '^*^* 

 the mineral, according to the conjecture of Bournon, 

 contained an alkali. For this purpose, 100 jj^rains of it, re- 

 duced to a tine powder, and mixed with 500 grains of ni- 

 trate of batytes, were exposed for an hour to a red heat, in 

 a porcelain crucible. The fused mass was softened with* 

 water, and trt-ated with muriatic acid. The whole dis- 

 solved, except "id grains of a white powder, whicKp^jpOved 

 on examination to be silica. The muriatic acid solution 

 was mixed with sulphuric acid, evaporated to dryness; 

 the residue, digested in hot water, and filtered, to sepa- 

 rate the sulphate of barytes. The liquid was now mixed 

 with an excess of carbonate of ammonia, boiled for an 

 instajntor two, and then filtered, to separate the earth and 

 iron precipitated by the ammonia. The liquid was evapo- 

 rated to dryness, and the dry mass obtained exposed to a 

 red heat in a silver crucible. The residue was dissolved in 

 water, and exposed in the open air to spontaneous ev'pora- 

 tion. The whole gradually shot into regular crystals of 

 sulphate of soda. This salt, being exposed to a strong red 

 heat, weighed 50 grains, indicating, according to Berthol- s^^la 

 let's late analysis, 23*5 grains of pure soda. It deserves to 

 be mentioned, that during this process the silver crucible 

 was acted on, and a small portion of it was afterward found 

 among the sulphate of soda. This portion was separated 

 before the sulphate of soda was weighed. 



The preceding analysis gives us the constituents tjf soda-" 

 lite as follows: 



Silica, - 38'^^ r^ ^ ... _> 



Lime, 2-70 



Oxide of iron, l-OO 



Soda, 25.50 



Muriatic acid, 3-00 



Volatile matter, ^^JO 



Loss, 1-70 



lou-00 



