300 EARTHS. 



(a.) *Let the Gadolinite be repeatedly digested in muriatic acid, 

 and silica remains. To the fluid, add liquid ammonia, boil the pre- 

 cipitate in solution of potash, and filter. Dissolve the insoluble resi- 

 due of the last process in diluted sulphuric acid, evaporate to dry- 

 ness, ignite, and redissolve it in water ; a precipitate falls down, which 

 must be separated by the filter. 



The filtered solution, when mingled with liquid ammonia, yields a 

 precipitate which is Yttria.f 



(b.) Fuse the Gadolinite 1 part, with caustic potash 2, wash the 

 mass with boiling water, and filter the liquor, which will be of a fine 

 green ; evaporate till the oxide of manganese, in the form of a black 

 powder, ceases to fall ; then saturate the liquid with nitric acid. 

 Digest the undissolved sediment in dilute nitric acid, which will dis- 

 solve the earth with much heat, leaving the silica undissolved, and 

 the iron highly oxidized. Mix the two liquors, evaporate to dryness 

 and redissolve and filter, which will separate any silica or oxide of iron 

 that may have been left. A little carbonate of potash will separate 

 any lime, and hydro-sulphuret of potash will precipitate any mangan- 

 ese ; but if too much be added, it will throw down the yttria too. 

 Lastly, ammonia will precipitate the yttria, which must be well wash- 

 ed and dried. } 



3. PROPERTIES. 



(a.) Ji fine white, powder ', infusible alone, but with borax melts 

 into a glass. 



(6.) Tasteless, smooth, and inodorus no effect on vegetable colors. 



(c.) Sp. gr. 4.842, greater than that of any earth. 



(d.) Insoluble in water, but absorbs it, and loses .31 of its weight 

 when heated to redness. 



(e.) Soluble in alkaline carbonates, but not in pure alkalies, like 

 alumina and glucina ; requires to dissolve it 5 or 6 times as much 

 carbonate of ammonia as glucina does. 



(/.) With acids forms sweet tasted salts, with some degree of 

 austerity, and several of them are said to be colored, a fact not ob- 

 served in any other metallic salts, but there can be little doubt that 

 the color is owing to the adhering iron and manganese. 



(g.) Solution of Yttria in muriatic acid, evolves chlorine after be- 

 ing long heated. 



(A.) Oxalic acid, and oxalate of ammonia, precipitate yttria like 

 muriate of silver. 



4. POLARITY. Supposed from analogy to be electro positive. 



5. COMBINING WEIGHT, 42. 



* Accum. Mineral, p. 137. 



t For the process of Vauquelin, see Ann. de Chim. p. 150, XXXVI, and Henry, 

 10th Ed. Vol. I, p. 625. 

 J Ure'sDict. 



