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



sought in various ways, but seldom according to right principles. 

 The French and the English nomenclature have this advantage 

 over the German, that the several degrees of oxidation of a matal 

 can be designated much more readily. But all have the defect, 

 that the oxides of the same name do not always belong to one 

 and the same group, the members of which with the same atomic 

 composition have similar properties. Thus, as regards their 

 atomic composition, protoxide of iron, protoxide of tin, with oxide 

 of copper and oxide of zinc, belong to the same group, while 

 they differ in their nomenclature ; and while oxide of iron and 

 oxide of lead have similar designations, they have different com- 

 position and properties. This has frequently unpleasantly sur- 

 prised the chemist, and a remedy for it has on many occasions 

 been sought. Thus oxide of nickel and oxide of cobalt are now 

 often called pr<Ttoxide of nickel and protoxide of cobalt, to bring 

 them into the same category with protoxide of iron and protoxide 

 of manganese, to which, indeed, oxide of zinc and oxide of copper 

 belong. But as many chemists, for good reasons, have not 

 adopted this innovation, an unavoidable confusion arises from 

 these various designations. 



This great defect may be obviated by taking the atomic com- 

 position as basis for the designation of the various metallic oxides. 

 Similar compositions correspond to similar properties, and in this 

 way natural groups are formed. In this respect I take upon 

 myself to make proposals. The names which I propose seem to 

 avoid all the disadvantages of the previous ones, and at the same 

 time suit all languages. 



In atomic relations we can distinguish five distinct classes of 

 salifiable oxides, of the following composition : — 



(1) 4 atoms of metal with 1 atom of oxygen. 



(2) « )t a I a )f 



(3) 1 atom „ 1 „ „ 



(4) 2 atoms „ 3 atoms „ 



(5) 1 atom „ 2 „ „ 



The last division of oxides can scarcely be considered as belong- 

 ing to the salifiable ones. 



If now the oxides of the different divisions are named accord- 

 ing to the number of oxygen atoms which are combined with 

 an atom of metal, they may have the following names : — 



(1) M+ \0, Quadrantoxide. 



(2) M+ |0, Semioxide. 



(3) M+ O, Isoxide. 



(4) M + 1^ 0, Sesquioxide. 



(5) M+ 20, Diploxide*. 



* The oxides of the composition R 3 O 4 are usually and justly regarded 



