1835.] Chemical Analysis of Gadolinite, Sfc. 409 



If the protoxide of iron be an essential constituent, the 

 oxide of cerium, glucina, and protoxide of iron must be in 

 the state of disilicates. 



II. EXPERIMENTS ON YTTRIA. 



The neutral colourless sulphate of yttria was dissolved in 

 water, and the solution, when treated by re-agents, exhi- 

 bited the following properties : — 



1. Prussiate of potash : A white chalky precipitate. 



2. Ammonia : A white precipitate, not soluble in excess. 



3. Potash : A white precipitate, not soluble in excess. 



4. Alkaline carbonates : A white precipitate, soluble in 

 excess. 



5. Infusion of nutgalls : O. 



6. Gallic acid : O. 



7. Tincture of nutgalls : White, merely from the alcohol. 



8. Alcohol: White. 



9. Chromate of potash : Yellow. 



10. Bichromate of potash : O. 



11. Hydriodate of zinc : tO. 



12. Sulphate of potash : O. 



13. Oxalic acid : A white precipitate. 



14. Oxalate of ammonia : A white precipitate. 



When a solution of muriate of yttria was exposed to the 

 galvanic action, chlorine was given out at the negative pole, 

 and a small quantity of some other gas, (probably hydrogen) 

 at the positive pole. A quantity of gelatinous matter col- 

 lected round the negative wire. 



Yttria is not altered by having a current of sulphuretted 

 hydrogen passed over it while heated to redness in a green 

 glass tube. 



When phosphorus in vapour is passed over yttria heated 

 to redness, a vivid ignition takes place, but no combination 

 is formed. The weight of the yttria remains unaltered. 



III. SALTS OF YTTRIA. 



1. Sulphate. — Sulphuric acid acts with considerable vio- 

 lence on anhydrous yttria, and with the evolution of consi- 

 derable heat. The solution crystallizes in doubly oblique 

 prisms, and also in acute rhomboids. 



