336 SUWHURET OF LEAD, COPPER, AND ANTIMOJfT. 



had been sent me, I requested Dr. Wollaston, to have (he 

 goodness to ascertain its nature. His examination informed 

 him, that it contained nothing but sulphur, copper, and 

 lnalys«d. antimony. Desirous of ascertaining if possible, whether 



the antimony were combined with the copper in it, or simply 

 intermingled with the sulphuret of this metal ; and this ore 

 being soluble, though very slowly, in cold nitric acid; I 

 first of all dissolved it in this acid. A part only of the 

 sulphur rose to the surface of the solution; and it is pro- 

 bable, that the rest was converted into sulphuric acid. The 

 copper dissolved entirely, and the antimony was precipitated 

 in the state of oxide. The latter, to judge from the size of 

 the specimen I had set to dissolve, was evidently in smaller 

 proportion than the copper. As this same substance is ex- 

 tremely fusible, I brought a thin piece, about four lines 

 long, to the state of fusion, and kept it so for a short time. 

 Great part of the antimony sublimed, covering the surface 

 of the body on which it rested with a white powder. The 

 fragment when cooled retained its form, and even its bulk. 

 On breaking it afterward, its fracture exhibited an aspect 

 exactly resembling that of the sulphuretted copper which is 

 produced by the last fusion, it could be cut with the same 

 facility, and the cut had a metallic lustre. Having after- 

 ward placed this fragment, which had been fused, in cold 

 nitric acid, and a fragment of simple sulphuret of copper 

 along with it by way of comparison, they both dissolved 

 slowly, comporting themselves exactly in the same manner, 

 and the solution contained nothing but copper. The so- 

 lution of each of these fragments produced the same black, 

 flocculent, and very light precipitate, which was nothing 

 but sulphur still united with a small portion of copper,, 

 which, no doubt, was the cause of its black colour. From 

 these details it appears to me there can be no doubt, that the 

 ore was a simple sulphuret of copper, with which antimony, 

 probably in the state of a sulphuret likewise, was inter- 

 mingled. This substance came from Bojojawlensk, near 

 Cathariuenbourg, in Siberia. 



II. On 



