OF ARTS AND SCIENCES. 251 



1,0558 gr. gave 0.1222 gr. (NHJ.O by titrition = 11.57% 



1.1873 gr. lost on ignition 0.2922 gr. = 24.61% HgO and NH3 



1.0558 gr. gave by titrition with KMnO^ 11.09% VPg 



The analyses lead to the formula 



5 WO3 . y.fi, . 4 (NHJ,0 + 13 aq, 

 or 



5 WO3 . V,0, . 4 (NH,),0 . 2 HP + 11 aq, 



if we regard the acid provisionally as G-basic, which requires : — 



Calc'd. round. 



oWOg 1160 64.99 — 



VA 183 10.26 11.09 



4 (NH,)20 208 11.65 11.57 



13 H2O ' 234 13.10 13.04 



1785 100.00 



The percentage of vanadic oxide found is too high, but there can 

 be no reasonable doubt as to the formula. I obtained the salt but 

 once, and then in small quantity. The solution gives a dull yellow 

 flocky precipitate with argentic and mercurous nitrates, and after a 

 time a yellow crystalline precipitate with excess of potassic bromide. 

 The ammonium salt is interesting as being probably the first term in 

 a series. It corresponds to the phospho-molybdate 



5 M0O3 . PoO^ . 3 (NHJ.O . 3 H,0 4- 4 Aq. 



The following may serve as starting points for further investigation. 

 "When normal baric tungstate, WO^Ba, is boiled for a long time with 

 a solution of ammonic meta-vanadate, it is very sl'owly dissolved to an 

 orange-yellow solution, which on cooling gives very beautiful square 

 tabular deep red crystals mixed with excess of baric tungstate. 12 : 5 

 baric tungstate dissolves more readily in the meta-vanadate, and gives 

 a bright orange-yellow solution, which on evaporation yields fine pris- 

 matic crystals. From the above it appears probable that the tung- 

 states of the heavy metals, both neutral and acid, will yield vanadio- 

 tungstates by boiling with alkaline vanadates, and possibly in this 

 manner various new series of salts may be formed. The costliness of 

 the material for this work has prevented a more thorough study on 

 my own part. 



10:1 Vanadio-tungstic Acid. — A solution of ammonic meta-vana- 

 date dissolves tungstic oxide readily on boiling, giving a deep orange- 



