Chemical Science. 413 



stance formerly called Thorina by the same philosopher. A new 

 mineral body, discovered by Esmark, near Brevig, in Norway, was 

 sent to Berzelius for examination. It was compact, black, brittle, 

 and semi-hard, having the vitreous fracture of gadolinite, a specific 

 gravity of 4.8, and producing a dark brown powder. Under the 

 blowpipe it loses water, and becomes yellow. The mineral con- 

 tains a new earth so like the substance formerly called thorina, as 

 to be at first mistaken for it; when, however, distinguished by 

 experiment, the name thorina was retained. 



The new earth is colourless and infusible after ignition, insoluble 

 in all acids except the sulphuric, and not rendered soluble in other 

 acids by calcination with alkali. It is insoluble in caustic potash, 

 but soluble in the carbonate ; heat partially precipitates the solu- 

 tion, cold causes re-solution. Its salts have a pure styptic taste : a 

 strong solution of the sulphate becomes a thick mass by boiling, 

 but it is soluble in cold water ; this property particularly charac- 

 terises the new earth. Sulphate of potash produces a precipitate 

 in the saturated solution, which is a double salt, soluble in cold 

 water. This is a character also of the salts of cerium. Ferro- 

 prussiate of potash precipitates it, as it does yttria. 



Potassium does not reduce thorina ; but the chloride, obtained in 

 the same manner as with alumina, is readily decomposed with a 

 feeble detonation. The product is a pulverulent grey metallic mass, 

 dissolving rapidly in muriatic acid, and but slowly in the nitric and 

 sulphuric acids. Neither water nor alkalies act upon the metal. By 

 friction it acquires lustre. It burns brilliantly in oxygen gas into 

 thorina, without exhibiting fusion. Thorina contains 11.8 per cent, 

 oxygen. The mineral (thorite), from which it was obtained, con- 

 tains per cent. 57.91 thorina — 18.98 silica — 9.5 water — 3.4 oxide of 

 iron — 2.58 lime — 2.39 oxide of manganese, and portions of the 

 oxides of uranium, lead, and tin, with traces of potash, soda, mag- 

 nesia, alumina, &c. — Hensmaris Repertoire. 



15. Analysis of Siliceous Minerals by Alkaline Carbonates. — The 

 ready fusion observed by M. Berthier * of many atomic mixtures 

 of salts may be applied to the analysis of siliceous minerals by alka- 

 line carbonates, aided by a spirit lamp. A mixture of five parts of 

 carbonate of potassa and four parts carbonate of soda is so fusible, 

 that between 200 and 300 grains may be rendered perfectly liquid 

 by a spirit-lamp iiame. If sand be added to the mixture, there is 

 an effervescence as lively as if acid had been added. This effer- 

 vescence occasions the expulsion of part of the substance; and by 

 the addition of too much sand, the mass would become too difficult 

 of fusion, unless the sand or mineral had been previously pulverised 

 and mixed with the carbonates. Hence the operation should com- 

 mence with the mixture of the carbonates and the mineral. In 

 this manner considerable quantities of felspar may be readily de- 

 * Quarterly Jour., N. S. vol.iv, p. 436. 



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