OF ARTS AND SCIENCES. 93 



if we suppose SboOg partially to replace WO3 ; but in view of the 

 very frecpieiit recurrence of 22 molecules of tiingstic oxide among 

 comjilex inorganic acids, I am disposed to double the formula given 

 above, and to write 



22 WO3 . G SboOg . 4 BaO + 36 aq. 



In the yellow oily salt obtained by precipitating sodic antimonoso- 

 tungstate by means of potassic bromide, and carefully washing with a 

 cold strong solution of the bromide, the ratio of the tungstic to the 

 antimonious oxide was determined and found to be nearly 8 WO3 to 

 2 SboOg, so that there is probably a series of antimonoso-tungstates 

 with the general formula 



8 WO3 . 2 SboOg . n R,0. 



The quantity of solution taken gave 0.1091 gr. SboS, = 0.0935 gr. 

 SbjO,, and 0.3417 gr. AYO3 =: 71.51 % VVO3 and 21.49 % SbgOg. 



ANTIMONO S 0-MO L YB D AT E S. 



The salts of this series are readily formed by boiling antimonious 

 oxychloride, SbOCl, with an acid molybdate. The conditions are 

 exactly the same as in the case of the corresponding antimonoso-tung- 

 states. There is almost always a greater or less reduction of the 

 molybdic oxide, and the solutions obtained have a greenish or green- 

 ish-blue tint from the presence of MooOg or a similar oxide. The 

 ordinary acid amnionic molybdate of commerce in cold solution readily 

 dissolves freshly preci[)itated antimonious oxide with only a slight 

 reduction of the molybdic oxide ; on boiling, much reduction takes 

 place. 



Anal i/tical Methods. — Antimonious oxide cannot be separated from 

 molybdic oxide by" means of hydric sulphide, as a greater or less pro- 

 portion of molybdic sulphide is always found. By proceeding in the 

 manner already pointed out for the separation of antimony from tung- 

 sten, it is possible, in many cases at least, to separate antimony from 

 molybdenum with a very satisfactory degree of accuracy. It will bo 

 found, however, always advantageous to add a quantity of potassic or 

 sodic carbonate sufficient to neutralize both the molybdic and anti- 

 monious oxides before fusion with potassic cyanide. Crucibles of the 

 best Berlin porcelain are alone adapted to fusions of this kind, and 

 even when these are employed the action of the alkaline mixture upon 

 the crucible must be taken into account. The best method is to add 



