M. H. Rose on a new Series of Metallic Oxides. 371 



copper, which, after purification from tin, weighed only 1*2501 

 grm. Both quantities of sulphuret of copper, which were obtained 

 as semisulpurets from the quadrantoxide decomposed by dilute 

 sulphuric acid, are in the ratio 1 : 2*9 ; and the dry quadrantoxide 

 of copper consisted therefore of a mixture of — 



Quadrantoxide of copper . . . . 96*56 



Diploxide of tin 3*44 



100*00 



It follows indubitably from these experiments, that there is a 

 degree of oxidation of copper which consists of 1 atom of oxygen 

 united with 4 of copper, which is decomposed by dilute sulphuric 

 acid into an atom of sulphate of copper and 3 atoms of metallic 

 copper. 



If quadrantoxide of copper in its mixture with water is treated 

 with dilute hydrochloric acid, there is formed at first a dark body 

 (perhaps quadrantichloride of copper), but on agitation metallic 

 copper is separated, above which is a layer of white semichloride 

 of copper, which, on further agitation, dissolves up entirely in 

 the excess of hydrochloric acid. Undoubtedly the quadrantoxide 

 is decomposed by hydrochloric acid into an atom of semichloride, 

 and into 2 atoms of metallic copper. 



If sulphuretted hydrogen is added to the mixture of qua- 

 drantoxide with water, it is changed after agitation into a black 

 body, which long remains suspended in the liquid. The black 

 body has quite the appearance of a homogeneous body, and not 

 that of a mixture of isosulphuret and semisulphuret with metal- 

 lic copper, and is therefore a quadrantisulphuret. But if it stands 

 for some time with an excess of sulphuretted hydrogen, it begins 

 to decompose ; a disengagement of hydrogen takes place, and 

 the quadrantisulphuret is changed into a higher sulphuret ; but 

 into what sulphuret it passes has not been made out. 



If the mixture of quadrantoxide of copper is treated with 

 aqueous hydrocyanic acid, it is also changed into a homogeneous 

 black body, which is quadranticyanide of copper. It readily 

 dissolves in dilute sulphuric acid at ordinary temperatures with 

 disengagement of red fumes, and forms a blue solution; the 

 solution smells of hydrocyanic acid, and gives with nitrate of 

 silver a copious precipitate of semicyanide of silver. If a solu- 

 tion of nitrate of silver is poured upon the quadranticyanide, 

 a blue solution is formed, and a blackish -brown mixture of 

 semicyanide of silver and metallic silver is formed. If this is 

 treated with nitric acid, a blue solution of nitrate of isoxide of 

 copper is formed, and semicyanide of silver is left. 



If the moist quadrantoxide of copper is treated with ammonia, 

 it is not dissolved, and is thus characteristically distinguished 



