26 Berzelius on a new Mineral Body, [Jan. 



This serpentine, when treated with concentrated muriatic acid, 

 is decomposed ; but the hquid contains neither selenium nor 

 copper : these two bodies remain undissolved with the silica — a 

 proof that neither of them existed in the mineral in the state of 

 oxide. On the other side, both nitric and nitromuriatic acids 

 dissolve the two metals before they have begun to attack the 

 serpentine. In the mine of Skrickerum, we find the following- 

 minerals along with the eukairite : yellow sulphuretted copper, 

 sometimes iridescent, sometimes in its natural state, and some- 

 times with a compact and tarnished fracture; carbonate of lime; 

 serpentine partly black, partly dark-green, and partly pale- 

 green ; and anthracite mixed with carbonate of lime in very thin 

 beds, which intercept the anthracite at the distance of one-sixth, 

 or one-third of a line. 



The discovery of selenium at Skrickerum occasioned a more 

 attentive examination of what might be found from that mine in 

 collections. M. Swedenstierna found beautiful specimens of a 

 carbonate of lime, which had great black spots in it, and he sent 

 me a specimen of it for examination. I observed that these 

 spots were formed round natural clefts in the carbonate, and 

 when the mineral was divided through these clefts, the new 

 surfaces were found covered with a white metallic vegetation. 

 A small plate of the black mass surrounding the clefts, being 

 seen through a compound microscope, presented a metallic vege- 

 tation, which penetrates the substance of the limestone in every 

 direction. 



I separated the metallic substance from the lime by dissolving 

 this last in muriatic acid. A considerable black mass remained, 

 which was dissolved in nitric acid. The solution, being mixed 

 with nitrate of barytes, did not give any precipitate. Muriate of 

 soda precipitated nothing ; but after an interval of some minutes, 

 the liquid began to assume a milky aspect, and in some hours 

 gave traces of a precipitate. The liquid, which was blue, being 

 mixed with an excess of ammonia, did not let any thing fall ; but 

 with subcarbonate of potash, it formed subcarbonate of copper, 

 and I then separated from the residual hquid, rendered acidulous 

 by muriatic acid, selenium, by means of sulphite of ammonia. 

 Hence the mineral which produces these black stains is a sele- 

 niuret of copper without any mixture of silver. Likewise the 

 metallic vegetation found in the clefts contains no traces of 

 silver, as I ascertained by detaching a small quantity which had 

 been dissolved in nitric acid and then mixed with muriatic acid, 

 without any other result than a feeble opalescence. 



It is well worth remarking that it is only the seleniuret of 

 copper which is found filtered into the porous parts of the car- 

 bonate of lime, as well as of the serpentine. Hence it seems to 

 follow that the selenim-et of copper was more liquid than the 

 eukairite at the time when these stony masses assumed their 

 actual form. 



