296 EARTHS. 



(b.) Or, to 1 part powdered zirconia, add 2 of potassa, and heat it for 

 one hour in a silver crucible ; add distilled water, filter and wash well 

 the insoluble part, which will be a compound of zirconia, silica, potash 

 and oxide of iron. Dissolve in muriatic acid, and evaporate to dry- 

 ness, to separate the silica. Redissolve the muriates of zirconia and 

 iron in water, and having washed the remaining silica with weak mu- 

 riatic acid, to remove any adhering zirconia, add it to the fluid. Fil- 

 ter and precipitate tlie zirconia and iron by pure ammonia ; wash 

 the precipitates well, and then boil them in oxalic acid ; this dis- 

 solves the iron and leaves the zirconia an insoluble oxalate, which is 

 to be washed until no more iron can be detected in the washings. 



The oxalate of the earth, which, when dry, is of an opaline color,* 

 is then to be decomposed by heat in a platinum crucible. f 



3. PROPERTIES. 



(a.) A fine white powder, tasteless and inodorous, resembles alu- 

 mina, but somewhat harsh to the touch ; sp. gr. after being heated vi- 

 olently on charcoal, 4.3. 



(b.) Infusible before the common blowpipe, but heated in a char- 

 coal crucible protected by an earthen one, in a good forge fire, for 

 some hours, becoming a substance like porcelain, insoluble in acids, 

 suffering a partial fusion, and acquiring a gray color. In this state, 

 it will scratch glass gives fire with steel, and has the specific gravity 

 of 4.3. 



(c.) Perfectly fusible before the compound blowpipe of Dr. Hare, 

 producing a white enamel.f 



(d.) Insoluble in water, but is absorbent of it, and when dried 

 slowly after being precipitated form a solution, it has a yellow color ; 

 retains about one third of its weight of water ; has a small degree of 

 transparency, and resembles gum arabic. When heated red in a cru- 

 cible of silver, it loses .37 of its weight. 



(e.) No action on combustibles, or oxygen, or nitrogen. 



(f.} Insoluble in alkalies, but dissolved in alkaline carbonates. 



(g.) Insoluble in acids, until it has been acted upon again by 

 caustic potash, and washed till the alkali is removed ; it is next dis- 

 solved in muriatic acid, precipitated by ammonia and the washed hy- 

 drate, is then easily soluble in acids, forming salts, and those with 

 the sulphuric, carbonic, and phosphoric acids, are insoluble in water. 

 In general, the salts of zirconia are insoluble, and those that are solu- 

 ble, have a sweetish astringent taste. 



* For a third process, see Thenard, Vol. II, p. 295, and Ann. de Chim. et de Phys. 

 T. XIII, p. 245. 



t Ann. de Chim. et de Phys. T. XIV, p. 110. 



t Am. Jour. Vol. II, p. 292. 



The hydrate heated by a spirit lamp in a glass capsule, becomes red hot, as 

 if it were on fire. Thenard. 



