212
PROOFS OF THE PROPERTIES OF ZIRCON.
cooliug. The sulphate of zircon is therefore soluble in muriaticacid ; and this solubility is increased by means of caloric.
2. The phosphoric, citric, tartareous, oxalic, and sacco-lacticacids decompose the muriate of zircon, and form with its baseinsoluble compounds, which are precipitated in the form ofwhite flocks.
3. The gallic acid precipitates the muriate of zircon, in theform of a white matter, (or in that of a greyish green, if it con-tains iron). The liquor in which the gallate of zircon has beenformed preserves a greenish colour; and, though fresh quantitiesof gallic acid do not occasion any’ more precipitation, the carbo-nate of ammonia separates a very copious flocky matter, whichhas a purplish colour, similar to that of lees of wine.
These experiments prove,...l. That the gallic acid has agreater affinity with zircon than the muriatic acid possesses, andthat the gallate of zircon is soluble in muriatic acid, since a partof it remained in solution in the liquor which was separated bycarbonate of ammonia.
2. Carbonate of potash, saturated with carbonic acid, precipi-tates zircon from its solution in muriatic acid; and thoughthis solution be made with effervescence, the precipitate, whenwashed and dried in the air, retains a large portion of carbonicacid, for this earth afterwards produces a lively effervescence,when dissolved in acids.
3. A solution of sulphurated hidrogen gas in water, mixedwith a solution of zircon (containing iron) disturbs the transpa-rency of the solution, and gives to it a reddish colour; but itdoes not occasion a true precipitate. The hidro-sulphuret ofammonia instantly precipitates this salt of a beautiful green co-lour, which becomes black when dry'. This precipitate whenplaced on burning coals, gives out the smell of sulphurated hi-drogen gas, and becomes of a bluish, or slightly purplish colourby pulverization ; before it has been heated it affords a powderof a pearl grey' colour. This colour is ow'ing to the oxid of ironcombined with the zircon.