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



the liquid became blue from dissolved copper. After the com- 

 plete deposition of the copper, the solution was removed from 

 the flask in the manner described above, and replaced by boiled- 

 out water, which operation was continued until no more copper 

 could be detected in the wash -water by means of sulphuretted 

 hydrogen. Both the copper deposited and that in the sulphuric 

 acid solution contained tin. The latter was mixed with ammonia 

 until it had only a feeble acid reaction, and it was thereupon 

 boiled, by which diploxide of tin was deposited, whose weight 

 was determined. The copper was precipitated from the solution 

 by sulphuretted hydrogen, the sulphide of copper ignited in a 

 current of hydrogen and weighed. The precipitated metallic 

 copper was dissolved in nitric acid, sulphuric acid added to the 

 solution, and the same process repeated as in the case of the 

 other solution. 



There were obtained — 



(1) From the sulphuric acid solution, 



0*3636 grm. semisulphuret of copper and 0*0348 grm. di- 

 ploxide of tin. 



(2) From the residue of metallic copper, 



1*0760 grm. semisulphuret of copper and 0304 grm. di- 

 ploxide of tin. 



If the new oxide of copper is decomposed by dilute sulphuric 

 acid into isoxide of copper and metallic copper, the copper in the 

 isoxide produced stands to the separated copper in the ratio of 

 1 : 2*959 ; hence, in the new oxide, 1 atom of oxygen is com- 

 bined with 4 atoms (in the experiment 3*96) of copper. But 

 the quadrantoxide investigated consisted in the dry condi- 

 tion of 



Quadrantoxide of copper .... 9493 



Diploxide of tin 5 *07 



10000 



The latter was, however, only mixed with the former, and might, 

 by repeated and renewed treatment with hydrate of potash, have 

 been removed from the quadrantoxide. 



The results of a second experiment of a preparation made at 

 another time, which had been repeatedly purified with hydrate 

 of potash, were as follows : — 0*469 grm. of semisulphuret of 

 copper was obtained from the sulphuric solution of the quadrant- 

 oxide decomposed by sulphuric acid. It had been precipitated 

 along with some tin, and, after weighing, it was dissolved in nitric 

 acid, and then freed in the manner above described from tin ; 

 after this purification the semisulphuret weighed only 0*432 

 grm. The metallic copper separated by dilute sulphuric acid 

 gave, after solution in nitric acid, 1*2731 grm. semisulphuret of 



