68 URANIUM, ANTIMONY, CHROMIUM, &c. 



Analysis of #. Tungstate of soda, formed by boiling toge- 



tungstate of ' 



soda. ther a solution of carbonate of soda and tungstic 

 acid, till the liquid refused to take up any more 

 of the acid, was set aside after being concentra- 

 ted as far as possible, so as to retain the liquid 

 state. In about a week it shot into fine crystals 

 of tungstate of soda ; these crystals were white 

 and semitransparent. The first time I obtained 

 them in pretty regular short six-sided prisms ; 

 but the second time I repeated the process/ the 

 salt shot into flat rhombic prisms. The lustre 

 of these crystals is silky ; however carefully 

 washed, they give a violet colour to cudbear 

 paper, and restore the blue colour of litmus pa- 

 per reddened by acetic acid. Yet the solution, 

 from which they had crystallized, had been 

 boiled for nearly a fortnight with a considerable 

 excess of hydrated tungstic acid. The taste of 

 this salt is at first sweet, but it speedily becomes 

 an intense and pure bitter, almost exactly si- 

 milar to the taste of quassia. 



3. After a considerable number of trials, which 

 it is needless to detail, I found that when 29'5 

 grains of these crystals are dissolved in water, 

 and mixed with a solution of 20*75 grains of 

 dry nitrate of lead, a double decomposition takes 

 place ; tungstate of lead precipitates in a white 

 powder, and the residual liquid is neither affec- 

 ted by sulphate of soda nor by nitrate of lead ; 

 showing, that it contains no sensible quantity 



