METHOD OF OBTAINING BARYTES.

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a powerful attraction for water, which it absorbs with a hissingnoise and consolidates it strongly. It is soluble in twenty timesits weight of cold, and twice its weight of boiling water. Itscrystals are loqg four-sided prisms of a sattin-like appearance. Itis a deadly poison to animals.

METHOD OF OBTAINING BARYTES.

1. Take native carbonate of barytes, reduce it to a fine pow-der and dissolve it in a sufficient quantity of diluted nitric acid,evaporate this solution till a pellicle appears, and then suffer itto crystallize in a shallow bason. The salt obtained is nitrateof barytes ; expose this nitrate of barytes to the action of heat ina china cup, or silver crucible, and keep it in a dull red heat forat least one hour, then suffer the vessel to cool, and transfer thegreenish solid contents, which are pure barytes, into a well stop-ped bottle. When dissolved in a small quantity of distilled waterand evaporated, it may be obtained in a beautiful crystalline form.

Rationale. ..The nitric acid added to the native carbonate ofbarytes unites' to the barytes, and expels the carbonic acid andforms nitrate of barytes; on exposing this nitrate to heat, itparts with its nitric acid, which becomes decomposed into itsconstituents, leaving the barytes behind.

2. Pure barytes may likewise be obtained from its sulphate.For this purpose boil powdered sulphate of barytes in a solutionof twice or three times its weight of carbonate of potash, in aFlorence flask for' about two hours, filter the solution, and ex-pose what remains on the filter to the action of a violent heat.

Rationale. ..In this case the sulphuric acid of the barytesunites to the potash, and the carbonic acid of the latter joins tothe barytes; hence sulphate of potash and carbonate of barytesare obtained. The former is in solution and passes through thefilter; the latter is insoluble and remains behind. From thisartificial carbonate of barytes, the carbonic acid may be drivenoff by heat.