174 Miscellaneous Intelligence. 



already been detected in some of the Bohemian sulphuric 

 acid, and it is supposed that the acid in question had been pre- 

 pared in Bohemia. The second source of selenium is in the 

 volcanic productions of the Lipari Isles, among which, Professor 

 Stromeyer has lately discovered a native sulphuret of selenium. — 

 Ellin. Phil. Jour. xi. 216. 



8. On Titanium, hi/ M. Peschier. — INI. Peschier, of Geneva, has 

 lately been engaged in examining the various combinations of tita- 

 nium. Many of his observations are analogous to those of 

 M. Rose*, which we have not room, therefore, to refer to; others 

 are new, and highly interesting. 



Having observed the acid nature of oxide of titanium, M. Pes- 

 chier boiled some ounces of finely-powdered rutilite in distilled 

 water, then concentrated and filtered the liquid, which had the 

 following properties : it was yellow, had a particular metallic taste, 

 strongly reddened litmus paper, and destroyed its colour ; it did 

 not crystallize, but on evaporation gave a pulverulent substance, 

 which was nearly all soluble in alcohol ; it slowly precipitated 

 salts ofiron, copper,mercury, and lead, and, after some hours, nitrate 

 of silver. Combined with potash, it gave a salt crystallizing in cubes; 

 with soda, a rhomboidal salt sligTitiy deliquescent, both soluble 

 in alcohol ; if the alkalies were in excess, the salt, with potash, was 

 permanent in the air, that with soda, deliquescent. 



Convinced of tlie acid nature of the oxide of titanium, M. Pes- 

 chier endeavoured to acidify it to the highest degree. A mixture 

 of nitrate of titanium and carbonate of potash, or of nitrates of 

 titanium and potash, were submitted to a high temperature, and the 

 residue diffused through water. A combination of the new acid with 

 potash dissolved, and could be thus separated; and this bemg de- 

 composed by sulphuric acid, the liquor evaporated, the substance dis- 

 solved in alcohol,(which takes the acid,) and the solution evaporated, 

 gave the acid in acicular crystals. This acid has no sensible action 

 on metallic or earthy salts ; it has a disagreeable metallic taste; 

 when subjected to the voltaic current, it gives out an odour of 

 phosphorus, and deposits a black substance at the negative pole ; 

 combined with subcarbonates of potash and soda, it gives acicular 

 prisms insoluble in alcohol, unle?s excess of the acid be present. 

 The salts affect a rhomboidal prismatic form. M. Peschier pro- 

 poses to call the liquid obtained from rutilite, titaneous acid, and 

 the one just described, titanic acid. 



M. Peschier endeavoured to reduce the dry oxide of titanium by 

 heating it with excess of potassum ; there was always heat, light, 

 and the evolution of hydrogen gas, perhaps from the heated oxide ; 

 and then by washing, a black powder was obtained, which retained 

 •water unless heated in hydrogen : heated in the air or in oxygen, 



* See Quarterlij Journal, xvi. 381. 



