OP ARTS AND SCIENCES. 267 



VANADIO-VANADICO-TUNGSTATES. 

 The class of salts to which I have given this name come also under 



the general formula 



m 



RO3 . n W.p, . p R"0, . X ^'\0, 



and constitute, like the corresponding compounds containing molybde- 

 num, a nevjr ternary series. They are formed under the same condi- 

 tions as these last, and like these have an orange or orange-red color, 

 with a more or less distinct tinge of green. 



12:2:3 (?) Vauadio-vanadico-tungstate of Sodium. — This salt, 

 whicli was the first which I obtained containing vanadium, was formed 

 by boiling with 12:5 acid sodic tungstate, a commercial vanadic pent- 

 oxide, which I owed to the kindness of Dr. J. Lawrence Smith, and 

 which was probably prepared by igniting ammonic meta-vanadate, 

 and therefore contained a certain proportion of vanadic dioxide. I 

 did not succeed in preparing it a second time with a new preparation 

 of the mixed oxides, and therefore trust that the incomplete analyses 

 and meagre description of this and the corresponding ammonium and 

 silver salts will be excused. The solution of the mixed oxides in the 

 acid tungstate gave a deep orange-red solution, which, on evaporation 

 to the consistency of a syrup, yielded after a time large orange-red 

 apparently triclinic crystals, extremely soluble in water, and crystalliz- 

 ing only from syrupy solutions. In this salt, twice recrystallized, — 



0.5968 gr. lost on ignition to fusion of the residue 0.1019 gr. =^ 17.07^ 

 0.6852 gr. " " " " 0.1 1 64 gr. = 16.99% 



0.331 1 gr. gave 0.2481 gr. WO3 + Yfi, + VO^ = 74.96% 



These analyses, taken in connection with those of the ammonium 

 and silver salts, may, with at least a certain degree of probability, be 

 considered as leading to the formula 



12 WO, . 2 VA . 3 VO, . 6 Na.p -f 43 aq, 



17.07 



4545 100.00 



