120 C. Refer stein on White Copper. 



Of what does this metallic substance consist ? Whence is 

 it obtained ? How is it treated ? On these points scarcely 

 any thing has vet been known ; for which reason, some time 

 aoro, I requested my brother M. Adolphus Keterstein, at Suhl, 

 who directs much of his attention to natural history, to insti- 

 tute the most exact inquiries that could be made respecting 

 these subjects, which appeared of considerable interest with 

 respect to the arts, and to mineralogy. 



The Society for Exploring Nature, at Suhl, likewise became 

 interested in the inquiry ; my brother sent some of the ore, 

 from which the white copper is made, at Suhl, to M. Brandes 

 at Salz-Uffeln, who is distinguished as a chemist, in order that 

 he might analyse, it ; and my brother also undertook, in con- 

 junction with M.Miiller of Suhl, to make inquiries on the spot 

 respecting the sources of the ore. 



The results were laid before the Society for Exploring Na- 

 ture, at Suhl, in a Report of which I have just received a copy, 

 and from which I am enabled to give an account of them to 

 the honourable meeting of German Explorers of Nature ; and 

 to this I beg leave to add some observations of my own. 



Analysis of the Ore from which the White Copper of Suhl is 



made, by theAulic Counsellor M. Brandes of Salz-Uffeln. 



A. 



On 100 grains of the ore were poured 2 ounces of nitric 

 acid, which was kept for some hours in gentle digestion, after 

 which the fluid was poured off, and the undissolved part again 

 digested with another half ounce of nitric acid. After the 

 digestion was finished there yet remained a trifling residue, 

 which gathered on a filter, previously weighed, amounted to 

 2'5 grains. In this residue small particles of sulphur could 

 be plainly perceived ; when it was heated before the blowpipe, 

 no arsenical vapour was perceptible, but a smell of burning 

 sulphur was produced. The whole heated in a crucible lost 

 0"75 grain of sulphur ; besides which a small quantity of sub- 

 limate of a white substance, becoming yellowish afterwards, 

 appeared on a copper plate with which the crucible was co- 

 vered ; this sublimate had the properties of oxide of antimony. 

 The residue of 1*75 grain was heated with a few drops of 

 nitric acid, by which a solution was formed, which gave a 

 brownish precipitate with ammonia, evidently oxide of iron. 

 The remainder of the residuum proved to be a slag of silex, 

 and clay, in which the metal occurs. 



B. 



The nitric solution A was now supersaturated with am- 

 monia, 



