298 Berzelius — Analysis of a New Mineral. 



hydrogen gas, from reddish brown changed to a blue grey, in- 

 clining to green, and lost again by the formation of water .03. 

 Rubbed in the mortar, the mineral now gave a dark grey pow- 

 der, very little acted upon by muriatic acid. 



b. Five grammes of thorite unheated and reduced to fine 

 powder, being treated with muriatic acid, became yellow, and 

 gave a slight odour of chlorine. By heat the evolution of chlo- 

 rine became stronger, and the whole was gelatinized. Evapo- 

 rated in a water-bath it left, after solution, .985 grammes of 

 silica. This was dissolved afterwards by boiling in carbonate 

 of soda ; the solution diluted with boiling water, the clear liquor 

 decanted, and the remainder boiled over again with carbonate 

 of soda, there remained undissolved in the alkali small grains 

 of quartz, a little powder of the stone which had escaped solu- 

 tion, and a light grey yellow powder which, by decantation, 

 could be separated from the foregoing. This powder weighed 

 .05 grammes; the heavier weighed .018, or together .07 

 grammes; after which there remained of undissolved pure silica 

 .915 grammes. The grey yellow powder contained much 

 silica in its composition, and, with carbonate of soda, before the 

 blowpipe melted into a glass. I have not examined this more 

 minutely. 



The aqueous solution which had been separated from the 

 silica, was precipitated with caustic ammonia, and the precipi- 

 tate well washed with boiling water. The ammoniacal liquor 

 which passed through was mixed with the evaporated washings, 

 saturated with oxalic acid, and slightly heated, till the precipi- 

 tate, which immediately appeared, had completely fallen. The 

 precipitated oxalate of lime, burnt and treated with carbonate of 

 ammonia, gave a slightly brownish carbonate of lime, weighing 

 .241 gr. It was dissolved in muriatic acid, and the solution 

 mixed, first with aqueous solution of bromine, and afterwards, 

 in a corked flask, with very dilute caustic ammonia, till the acid 

 was, in a minute degree, oversaturated. After twenty-four 

 hours, there had separated from the solution, which, by degrees, 

 became yellow, a quantity of oxide of manganese, which, heated 

 to redness, weighed .01 gr. The true weight of the carbonate 

 of lime, therefore, was .23 gr., answering to .1288, or 2.576 

 per cent, of pure lime. 



