266 PROCEEDINGS OF THE AMERICAN ACADEMY 



ration. Tlie barium salt is very slightly soluble in cold water, and is 

 decomposed by boiling water, with separation of baric molybdate, and 

 formation of a pale greenish-yellow solution, which possibly contains a 

 new salt of the same class. The salt is decomposed by boiling with 

 mercurous nitrate, giving a bright yellow crystalline body. Boiled 

 with argentic nitrate it gives an orange-colored precipitate, which is 

 also crystalline. Of this salt, — 



1.1 GOO gr. gave 0.72G0 gr. WO3 -f V^O^ + VO., = 62.09% 



and 0.4772 gr. SO.Ba = 20.80% BaO 



1.5526 gr. gave 0.6332 gr. " = 26.70% " 



1.0341 gr. lost on ignition 0.1127 gr. = 10.90% Hfi 



2.1990 gr. gave by titrition 0.1748 gr. = 7.95% Yfi^ 



The titrition was effected by SOJI, + SO^(NH4)2 -f- 6 aq, in a solu- 

 tion to which HCl had been added, after oxidation with nitric acid and 

 addition of an excess of sodic carbonate. All the vanadium present 

 was therefore estimated as VgO^. 



The analyses correspond closely to the formula 



30 M0O3 . 2 V2O5 . 3 VO2 . 14 BaO + 48 aq, 

 which requires : — 



7941 100.00 



The compound is doubtless a double salt, and its formula may 

 perhaps be 



2 {6 M0O3 . Y,0, . 4 BaO . 2 H,0} -j- 



3 (6 M0O3 . VO,, . 2 BaO . 4 H^O} -f- 32 aq ; 



only it must be remarked that the empirical formula given above must 

 be doubled in order to obtain a symmetrical structural formula, as the 

 number of molecules of vanadic dioxide is uneven in the simpler ex- 

 pression given. 



