1870.] 



Prof, lloscoc on Vanadium. 



321 



Silver Vanadates, 



1 . The Ortho-Silver Vanadate, Ag 3 V0 4 , is obtained as an orange-coloured 

 precipitate by mixing a freshly prepared solution of the trisodium salt with 

 a solution of silver nitrate, in which every trace of free acid has been 

 neutralized ; unless these precautions are attended to, the precipitate con- 

 sists of a mixture of the ortlio- and pyro-salt. The trisilver vanadate is 

 insoluble in water, but readily dissolves in ammonia and nitric acid. 

 Analysis gave the following results : — 



Calculated. Found (mean). 



Ag, =321-0 7375 73-83 



V = 51-3 11-07 11-76 



(X = 64-0 14-58 



4 



439-3 100-00 



2. The Tetrabasic Silver Vanadate, Ag t P 2 O r , is prepared by mixing a 

 solution of the corresponding sodium salt with a neutral solution of nitrate 

 of silver. It falls as a yellow dense crystalline precipitate, resembling in 

 colour the ordinary phosphate of silver. On dissolving the salt in nitric 

 acid, the silver is precioitated as chloride, and the vanadium determined as 



vo, - 



Analysis gave: — 



Calculated. Found. 



Ag 4 =432 66-81 66-45 



V 2 = 102-6 15-87 15-97 



0 7 =112-0 17-32 



646-6 100-00 



The reactions of the tri- and tetrabasic vanadates of the other metals 

 are then described. 



The author has to thank Messrs. Oelhofer and Finkelstein for the valuable 

 assistance which they have given him in the above investigation. 



The Society adjourned over the Easter Recess to Thursday, April 28. 

 April 28, 1870. 



Dr. WILLIAM ALLEN MILLER, Treasurer and Vice-President, 



in the Chair. 



Principal Dawson, LL.D., of M'Gill College, Montreal, was admitted 

 into the Society. 



The following communications were read : — 



