30 P. T. Cleve, 



Vanadates of samarium. 



The neutral solutions of the salts of samarium and alkaline meta- 

 vanadates give a light yellow perfectly amorphous precipitate, consisting 

 for the greater part of hydrated orthovanadate of samarium. The num- 

 bers found on analysis did not agree sufficiently well with those calcu- 

 lated to make me think it worth publishing them. If a solution of bi- 

 vanadate of sodium be mixed with a solution of the nitrate of samarium, 

 a yellowish amorphous precipitate is thrown down, probably the ortho- 

 vanadate of samarium, and from the filtered solution on spontaneous 

 evaporation at the ordinary temperature two different sets of crystals 

 are obtained. The one set has the colour of bichronate of potash and 

 the other a more yellow colour. Both form large, extremely beautiful 

 crystals. 



A. The red salt 8m,0,,5Y,0, + 28R,0. 



0.3760 gram lost on heating to 100° 0.0864 gram HgO and at 

 incipient redness 0.0196 gram more. The anhydrous salt was dissolved 

 in HCl and reduced with SOj. On adding oxalic acid and igniting the 

 oxalate 0.0726 gram SmjOg was obtained. The filtrate from the oxalate 

 of samarium was evaporated to dryness and the residue carefully heated 

 so as to volatilize the excess of oxalic acid. It was then oxidised with 

 very dilute nitric acid, evaporated to dryness and heated so as to melt 

 the vanadic acid, the weight of which was found to be 0.1953 gram, 

 but which however contained 0.0027 gram SnigOg. The analysis had thus 

 given 0.1926 gram V2O5 and 0.0753 gram SnijOg. 



99.44 1762 100.00 



Spec. Grav: 



0.8846 gram, large crystals, temp. 17°.5, sp. Gr. 2.522 

 0.8702 » » » » IT^.B, » » 2.526 



Mean of both determinations: 2.524 



Molecular volume: 1762/2.524 = 698. 



