s 



XO ANALYSIS OF FLUOR-SPAR. 



I first tried to decompose the filiate of lime, by 

 fusing it with twice its weight of carbonate of 

 potash in a platinum crucible. Only a small por- 

 tion of the fluate was decomposed. I was, there- 

 fore, obliged to repeat the fusions very often, 

 washing off the alkali after each operation, by 

 means of water, and then dissolving the carbonate 

 of lime formed, in muriatic acid. Fatigued with 

 the tediousness of this method, and despairing of 

 an accurate result from the great number of suc- 

 cessive solutions, I abandoned it altogether, and 

 adopted the following method, much more expe- 

 ditious and equally precise. 



From a mass of fluor-spar which I had ascer- 

 tained to contain no sensible portion of foreign 

 matter, I separated 100 grains, which I reduced 

 to powder, and digested for some hours in a plati- 

 num crucible, with rather more than an ounce of 

 pure concentrated sulphuric acid. The mixture 

 was then evaporated to dryness, and the crucible 

 exposed for an hour to a strong heat, in a wind 

 furnace. To ensure the complete decomposition 

 of the fluor, the mass was reduced to powder, and 

 treated a second time in the same manner with 

 another ounce of sulphuric acid. The residue, 

 which was white with a slight shade of red, prov- 

 ed, on examination, to be pure sulphate of lime. 

 It weighed 156.6 grains. 



Now, it has been ascertained by the most care- 

 ful experiments, that sulphate of lime thus vio- 



