21 C Aeiu Metal discovered by M. Tromsdorff. 



oF copper money. After twenty-four hours the piece was 

 covered with a grayish yt-llow crustj which, when rubbed 

 with a burnisher, took the colour of shining iron. 



/;. He divided the remaining part into three portions, 

 which he dccornposcd by pruosiatc of potash, hydro-su-L- 

 phurct of ammonia, and tincture of galls : exactly the 

 same results were obtained as in the preceding trials with 

 the same reagents. 



Having exhausted bv these experiments his supply of 

 mineral, "M. Tromsdorff was obliged to state his researches. 

 He concluded from the results, that the fossil forms a 

 combination of sulphur with a new metal. But he says he 

 cannot yet pronounce this with rigorous certainty. Tt is 

 proved that the fossil contains a metal, as much by its 

 rnauner of acting with the rengejits, as by its precipitation 

 by copper, and by the metallic aspect of the substance which 

 it forms by sublimation. And it is not doubtful that ii 

 contains sulphur, since we can really separate this sub- 

 stance. 



The first experiment proved that this metal is volatile, 

 for it leaves not a single residue on the fire. We know no 

 other metals that are volatile but mercury, bismuth, arsenic, 

 -zinc, and antimonv. The metal in question cannot be 

 mercury ; for, besides its fluid form, this metal produces 

 vermilion in combination with sulphur, of which it has 

 not been possible here to discover the slightest trace, l^ 

 cannot be bismuth, which is less volatile, and of which the 

 acid solutions are precipitated by the prussiate of potash of 

 a yellowish colour, by hydro-sulphuret of ammonia of a 

 blackish-brown colour, and by ga^ls of a yellow greenish 

 colour. It cannot be arsenic, or that would have dis- 

 covered itself by the smell, and which besides would not 

 have yielded the phaeitftniena observed. Still less can it 

 be zinc, which requires a verv strong heat to volatilize it, 

 which is precipitated by the reagents employed by our au- 

 thor under quite different colours, and which, instead of 

 being precipitated by copper, does itself precipitate thai 

 metal. Finally, antimony is precipitated of & white colour 

 by prussiate of potash, and orange by hydro-sulphuret of 

 ammonia, and its solution in sulphuric acid is not at all 

 reddish, as is that of our metal. M. Tromsdorff concludes 

 from all this, that the fossil he has examined is in all pro^ 

 bability a combination of sulphur with a metal hitherto 

 uiiknown. 



. . XLIir. On 



