316 METALLIC OXIDE?. 



Yellow oxide Now, if we calculate the composition of the yellow oxide 



by n. acid ap- obtained by the action of nitric acid upon antimony, we shall 



pears to be . . ' r . 



composed of find it such as it would be if composed of the white oxide and 



(fee white and the yellow oxide, in such proportions as that each of them 

 vellovv oxides, ... . . .,-.«. 



in portions should contain an equal quantity of oxtgen*. 



containing 



equal qoanti- [The following annotation, 07 account of its length, is continued 



ties of oxigen. ^ ^ ^ of ^ e M ^ 



Other in- * In proportion as our researches shall be extended, we 



compounds of sna ^ mic * aDnndance °f *" cts °f tms nature. In my first essay 

 two oxides, upon determinate proportions, I had the notion, that the dif- 



each of which f erence f co i ur in precipitates, caused by the alkalis in the 



appears to \ i > J 



eontain the solutions of iron depended on a combination of two degrees of 



same quantity oxidation of iron, which probably afforded salts with excess of 



or oxisren ; and , , 



serve as the base, and I gave examples in the nomenclature by the prussias 



bases of com ferroso-ferricus, sulfas ferroso-ferricus, &c. One circumstance, 

 pound salts. . . , ., . , ■ . . .. , . . . t 



which strikingly proves these notions, rs found in the phosphas 



ferrosus. By precipitating sulphas ferrosus by means of a 

 neutral phosphate, a white precipitate is obtained j and the 

 same happens by precipitating the phosphas ferricus. But the 

 first, the phosphas ferrosus, acquires a fine blue colour by the 

 washing, which does not happen with the latter. In fact, a 

 blue precipitate is obtained by the alkaline phosphates, in a 

 mixture of the sulphas ferrosus and sulphas ferricus. The 

 blue phosphate of iron is, therefore, a salt with double basis, 

 containing the two oxides of iron, representing two different 

 bases, and it constitutes a phosphas ferroso ferricus. The phos- 

 phas ferrosus, on the contrary, is whhe, as well as the phosphas 



Metals pos- ferricus. I have reasons to think, that several metals, viz. 



sess this 



habitude. manganese, uranium, cerium, and mercury, have the property 



of producing salts with double bases, by combining their two 

 degrees of oxidation. But it is, no doubt, still more interest- 

 ing 



