OF ARTS AND SCIENCES. 265 



The analyses lead to the formula 



5481 100.00 



The compound is doubtless to be regarded as a double salt, but 

 there are at present no data upon which to base even a conjectural 

 arrangement. The salt is slightly soluble in cold water, the solution 

 being strongly acid to litmus paper. It is soluble in hot water, and 

 separates from the solution without sensible decomposition. The solu- 

 tion is reduced with great diihculty, either by sulphurous oxide or by 

 sulphydric acid gas. For analysis I found it best, after oxidation with 

 nitric acid, to boil with excess of ammonia, evaporate with ammonic 

 chloride, and separate the ammonic meta-vanadate upon an asbestos 

 filter. The vanadium was then determined by titrition with liyper- 

 mauganate. The vanadic dioxide was determined by hypermangauate 

 in the solution of the salt, after adding phosphoric and sulphuric acids. 

 It was found necessary to use very dilute solutions, and the close 

 agreement of the determination of vanadic dioxide with the formula 

 cannot be regarded as other than accidental. The reactions of this 

 salt are as follows: the cold dilute solution gives no precipitate 

 with salts of zinc, copper, manganese, and cadmium ; a pale yellow 

 flocky precipitate. with baric chloride, which soon becomes granular- 

 crystalline ; with potassic bromide, after some days, very fine, large 

 prismatic crystals; with argentic nitrate, the solution gives a flocky 

 precipitate, which is yellow with a tinge of buff; with mercurous 

 nitrate, a bright, and with thallous nitrate, a pale yellow, flocky 

 precipitate. 



15 : 1 : 2 Vanadio-vanadico-mohjhdate of Barium. — Baric chlo- 

 ride added to the mother liquor from which the preceding salt was 

 prepared gave a pale yellow crystalline, and, so far as could be seen, 

 homogeneous precipitate, in very small grains. This was filtered 

 off, well washed with cold water, and dried on woollen paper for 

 analysis. The filtrate was greenish, and gave no other salt on evapo- 



