GEOLOGY. 291 



cliate in its properties between magnesia and manganese. The color 

 of the mineral when pure, is of a pale yellowish-green, consistence and 

 hardness about that of wax. Specific "gravity, 2.548. It has not been 

 found crystallized. Treated with hydrochloric acid, chlorine is evolved, 

 and the greater part of the constituents, except silica, dissolved. 

 About 10 per cent, of the mineral is made up of the supposed new 

 earth, which when separated has the following properties and reac- 

 tions with re-agents : It dissolves either in hydrochloric or nitric 

 acid evolving chlorine from the former acid. The solution in hydro- 

 chloric acid, when concentrated, has a beautiful pea-green color, and 

 the .salt crystallizes either of a slightly paler green, or a light chrome 

 yellow, depending on the degree of heat at which the evaporation is 

 completed. The peculiar color of its salts, together with the appear- 

 ance of the residue left in the analytical process after treating with 

 caustic potash to separate the alumina, was what first attracted my 

 attention to this earth. When separated, and still slightly contamin- 

 ated with magnesia, the earth has a pale, flesh color, not unlike yttria. 

 When freed from magnesia, it has more the appearance of powdered 

 dried albumen. The earth differs from alumina and glucina in being 

 insoluble in caustic potash. From magnesia in producing colored 

 salts ; in being only slightly soluble in ammoniacal salts ; in the pecu- 

 liar vesicular character of the precipitate with phosphate of soda ; in 

 being precipitated with oxalate of ammonia. From yttria it differs 

 in not giving a precipitate with oxalic acid in slightly acid solutions ; 

 in being precipitated by slice-mate of ammonia, even before the solu- 

 tion is quite neutral, which prevents this re-agent being applied to 

 separate iron from it, as is recommended by Berzelius for separating 

 oxide of iron from yttria. It differs from zirconium in being soluble 

 in nitric and muriatic acids after ignition. From cerium, in not turn- 

 ing a brick-red after ignition, and in the color of its salts which are 

 not amethystine, but shades of green and yellow, except the nitrate, 

 which is almost colorless. The nitrate crystallizes in prisms, which 

 seem to be right-rhombic. Its salts, like the corresponding ones of 

 magnesia seem to be deliquescent. From the quantity of chlorine 

 evolved during the solution of the mineral and earth in hydrochloric 

 acid, it appears that this earth must exist in at least two degrees of 

 oxidation ; the chlorine being disengaged, just as in the case of the 

 solution of the higher oxides of manganese when treated with hydro- 

 chloric acid. From these and other consideration Dr. Owen^con- 

 cludes, that the earth contained in the mineral, which is nearly inso- 

 luble in sal-ammoniac, insoluble in caustic potassa, and producing the 

 above reactions with re-agents, and green and yellow salts, must be 

 either a new earth or else^ a modification of some known earth not 

 previously known. The name Thalium is proposed for the base of 

 this earth, Thalio for the earth itself, and Thalite for the mineral from 

 which it is extracted. 



The new metal Donarium* the discovery of which was announced 

 last year by Bergeniann, proves to be nothing but Thorina. 



* See Annual of Scientific Discovery, 1852, p 176. 



