372 Preparations and Compositions. Part III

I

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Chap. IV.- EARTHS, and EARTHY SALTS.

MURIAS BARYTJE. Ed.

Muriate of Baryta.

Take of

Carbonate of baryta,

Muriatic acid, of each one part;

Water, three parts.

Add the carbonate, broken into little bits, to the water andacid, previously mixed. After the effervescence has cea-sed, digest for an hour, strain the liquor, and set it aside tocrystallize. Repeat the evaporation as long as any crystalsare formed.

If the carbonate of baryta cannot be procured, the muriatemay be prepared in the following manner from the sulphate.

Take of

Sulphate of baryta, two pounds ;Charcoal of wood, in ponder, four ounces.

Roast the sulphate, that it may be more easily reduced to avery fine powder, with which the powdered charcoal is to beintimately mixed. Pat the mixture into a crucible, and ha-ving fitted it with a cover, heat it with a strong fire for sixhours. Then triturate the matter well, and throw it intosix pounds of water in an earthen or glass vessel, and mixthem by agitation, preventing as much as possible the ac-tion of the air.

Let the vessel stand in a vapour bath until the part not dis-solved shall subside, then pour off the liquor. On the un-dissolved part pour four pounds more of boiling water,which, after agitation and deposition, are to be added tothe former liquor. Into the liquor, when still warm, or ifit shall have cooled, again heated, drop muriatic acid aslong as it excites any effervescence. Then strain it, andevaporate it so as to crystallize.

In the materia medica of the Edinburgh college, the car-bonate of baryta is introduced, for the purpose of Forming themuriate; but as that mineral is not very common, and some-times not to be procured, it became necessary to describe themanner of preparing the muriate from the sulphate. This is,however, attended with very considerable difficulties, on ac-