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



from semioxide and isoxide of copper. But if only a limited 

 access of air is permitted, the green quadrantoxide is first 

 covered with a yellow coating of semioxide of copper, and 

 gradually the supernatant liquid becomes somewhat blue. 

 Even when a mixture of ammonia and carbonate of ammonia is 

 used, quadrantoxide of copper undergoes not the least change if 

 air is completely excluded. 



By these experiments it is shown that the compound prepared 

 is a definite oxide of copper, of a constitution not hitherto sus- 

 pected, except in the case of the quadrantoxide of silver. That 

 the oxide of silver, which hitherto has been called suboxide of 

 silver consists of 4 atoms of silver and 1 of oxygen, can now be 

 as little doubted as the necessity for halving the atomic weight 

 of silver which has previously been adopted. Quadrantoxide of 

 copper and quadrantoxide of silver belong to the same group. 

 The oxides also, which are generally called suboxide of copper 

 and oxide of silver, and which are semioxides, belong to one and 

 the same group ; as do the oxides which are called binoxide of 

 silver and oxide of copper, which are isoxides. The properties 

 of both these oxides (of the same atomic composition) are, it is 

 true, very different ; for hitherto it has not been possible to com- 

 bine isoxide of silver with acids to form salts, as in the case of 

 isoxide of copper. On the other hand, no chemist will doubt 

 the atomic weight of copper, or the atomic composition of the 

 hitherto known oxides of copper, and call what is known as oxide 

 of copper a diploxide, and the so-called suboxide of copper an 

 isoxide. 



I have stated above that the number of metallic quadrant- 

 oxides is probably by no means small ; I must even assume that 

 the group is numerous. 



Bunsen has succeeded in removing by electrolysis chlorine from 

 the chlorides of alkaline metals, especially from chloride of 

 potassium, chloride of rubidium, and chloride of csesium, and 

 changing them into lower chlorides of intense smalt-blue colour, 

 which dissolve in the fused metallic chlorides*. These chlo- 

 rides can be prepared without electricity by fusing potassium 

 with chloride of potassium in a current of hydrogen. An intense 

 dark blue saline mass is thus obtained which dissolves in water, 

 liberating hydrogen and forming chloride and hydrated alkali. 

 Chloride of sodium fused with sodium in a current of hydrogen 

 gives a bluish-grey fused massj\ It may be assumed with great 



* Poggendorff 's Annalen, vol. cxiii. p. 344. 



t The blue rock-salt which occurs in nature does not owe its blue colour 

 to quadrantichloride of sodium, or rather potassium. The clear blue rock- 

 salt of Stassfurth is not uniformly coloured ; along with clear blue cubes 

 there are some well-defined perfectly colourless cubes, as well as some 



