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II. An Analysis of Fluor-Spar. 



By Thomas Thomson, M. D. F. R. S. E. 



1U>& Jz^ 1808.J 



The mineral called Fluor- Spar, has been long- 

 known, and valued on account of its beauty, and 

 the ease with which it can be turned on the lathe 

 into various ornaments and useful utensils. It 

 occurs chiefly in veins, and very frequently ac- 

 companies lead-ore. Some of its properties have 

 been described more than a century ago, as, for 

 example, its phosphorescing when heated, and its 

 corroding glass when mixed with sulphuric or ni- 

 tric acid. But it is not forty years since its com- 

 position was discovered by Scheele, who demon- 

 strated, that it is composed of lime, and a pecu- 

 liar acid, called Fluoric. Chemists now distin- 

 guish it by the name of Fluate of Lime. 



Hitherto, no chemical analysis of this salt has 

 been published, except a very incorrect one by 

 Kirwan and Gren, which has been ascribed to 

 Scheele, though I cannot find it in any of his dis- 

 sertations on fluor-spar. By that analysis, it is 



