184 analyssis of 



Sulphuric acid was added to the Carbonate of 

 Lime, which converted it into Gypsum and dissolved 

 the Iron mixed with it. It was filtered and the Iron 

 so held in solution, was thrown down by ammonia 

 thus separated and calcined, it weighed 2 grains. 



The result of this Analysis, gives us on estimating 

 the quantity of lime by difference, 



Silex - - 77. 5 or per cent. M. 67 

 Lime - - 70. 5 - - 47. 00 

 Oxide of Iron - 2. - - - 1. 35 



100. 100. 00 



But as the Iron appears to be an accidental ingredi- 

 ent in this mineral, the real composition of it will be, 



Silex 52. 36 ~> Containing according to this (26. 71 > of oxi~ 

 lame 47. 64 3 presumed composition, ^ 13. 38 5 g e n« 



100. 00 



Hence this mineral is a bisilicate of Lime, if the 

 oxygenous composition of these earths be correct ; 

 the quantity of oxygen in the Silex being twice that 

 contained in the Lime. 



From the external and other characters of this mi- 

 neral, and from its chemical composition, it appears 

 to be identical with the rare mineral called Schaal- 

 stein or Table Spar, although according to the Ana- 

 lysis of Klaproth, this mineral contaius 5 per cent, 

 of water. But Berzelius in his new system of mine- 

 ralogy published in 1819, at Paris, says, "from ex- 



