OF ARTS AND SCIENCES. 89 



PHOSPHOROSO-MOLYBDATES (acjain). 



As the pliosphoroso-molybdate of ammonium, which 1 have described 

 in another part of this pnpev, appeared to contain a trace of pliosphoric 

 acid, I repeated the preparation with a perfectly pure solution of 

 jDhosphorous acid obtained by the action of water upon phosphorous 

 chloride. The liquid contained, of course, free chlorhydric acid, and 

 was poured into a cold strong solution of 14 : G amnionic molybdate. 

 A sulphur-yellow precipitate was at once formed, consisting of very 

 minute talcose scales. The salt was washed on the filter-pump very 

 thoroiiglily with cold water, and dried on woollen paper. It is readily 

 soluble in hot water to a yellow liquid. The solution on boiling re- 

 duces mercuric chloride to mercurous chloride. It gives an abundant 

 white, flocky j^recipitate with argentic nitrate, which on long boiling 

 becomes darker. Finally, silver is reduced. In this preparation, 



0.7247 gr. lost with WO^Na^ 0.1150 gr. = 15.87 % 

 0.8323 gr. gave 0.03SG gr. (NII^^O = 4.G4 r^ 

 0.742G gr. " 0.077G gr. PaO.Mg^ = 6.G8 % ¥^0. 

 0.9517 gr. " 0.0994 gr. " = G.68 f^ " 



The phosphorous acid was oxidized by bromine in presence of an 

 excess of COgNatl. The analyses correspond most nearly to the 

 formula 



24 M0O3 . 4 PO3H3 . 4 (NHJa 0-1-25 aq. 



Calc'd. Found. 





4442 100.00 



The analyses confirm the formula first obtained, though the new 

 salt contains eight molecules more of water of crystallization. 



ANTIMONOSO-TUXGSTATES. 



When solutions of an acid tungstate of sodium are boiled with anti- 

 monious oxide, the latter very slowly dis.'^olves, and it is dilficult to 

 obtain perfectly saturated solutions. It is best to em[)loy antimonious 



