MUR

M U R

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place with fuch minute quantities as to renderthe muriat (as well as the other foluble falts)of barytes a moft valuable left for fulphuricacid in any,form. Nitric acid alfo decompofesthis muriat, and if it is much concentrated awhite precipitate of nitrat of barytes falls down,owing to the more fparing folubility of thenitrat in water than of the muriat. But it isdillblved by adding more water, by which itmay be readily diftinguilhed from the fulphat.

Muriat of barytes is ufed as a tell for ful-phuric acid in chemical experiments. It hasalfo been employed in medicine, and like allthe other foluble barytic falts it is a powerfulpoifon in large doles.

Muriat - of Strontian.

This fait is prepared by difiolving ftrontianor its carbonat in muriatic acid. The modes ofprocuring ftrontian will be found under thearticles Strontian and Carbonat of Strontian. Thefait cryftallizes in long needles, very tender andeafily broken, the form of which it is not eafyto determine, but the linking difference in theappearance of muriat of ftrontian and muriatof barytes will readily enable the chemift todiftinguifh thefe falts, which in other refpedlshave many properties in common.

Muriat of ftrontian is one of the moft folubleof all the known falts. A hundred parts of thecryllallized fait required but 75 of water at amoderate temperature, and when heated itdiffolves in its own water of cryllallization.Alcohol when boiling alfo diffolves a largequantity, but the greater part.is again feparatedby cooling. The alcoholic folution when fetlire to, burns with a beautiful crimfon flame,which is a very ufeful tell for ftrontian. Thetafte of the fait is cooling at firffc, and after-wards rather acrid, but not auftere like muriatof barytes, nor bitter. It is not poifonous.This (alt is not delfquefcent. When heated itlofes its water of cryllallization, but none of itsacid. Its component parts according to Vau-quelin, are (in the cryllallized llatej 36.4 ofltrontian ; 23.6 of acid ; and 40 of water.

It is not applied to any ufe.

Muriat of Magnesia.

Magnelia diffolves in muriatic acid with greatea fe, forming a bitter naufeous fait which can-1 w Mi extreme difficulty be brought to

n \ but when evaporated nearly to dry-

e 3 ecomes a gelatinous, lhapeleis, deliquef-cent mafs Tt ; r 11 1 , • 7

particularly in r found 1 “ natme -

f 1 ■ n y m lea-water, to which this owesus bitter naufeous tafte. It alfo often accom-

panies common fait in the water of inland brine -ipritigs.

This fait is extremely foluble, requiring onlyits own weight of cold water. Boiling watertakes up much more, fo that a hot faturatedfolution on cooling coagulates to a gelatinousmafs.

’Muriat of magnelia is compleatly decompo-fable by heat, the whole of the water of crys-tallization and the muriatic acid flying off andleaving the magnefia pure. In this refpedl itdiffers from muriat of lime, with which it isoften mixed, fo that it affords an ufeful wayin analyfis of feparating thefe earths, which'has fometimes been adopted. After calciningthe two falts, therefore, muriat of lime andpure magnefia are left, which mere folution inwater will feparate. As however muriat oflime is partially decompofable by the fame me-thod, it probably would require a repetition ofthe calcination of the refidue with frelh acidto feparate the earths compleatly.

Muriat of magnefia is readily decompofableby the fixed alkalies and the alkaline earths.With ammonia, only a part of the earth isfeparated in a moderate heat, and the remainderunites with the undecompofed portion into atriple fait, the muriat of magnefia with atmnonia yor ammmhaeo rnagnefian muriat , which will beprefently mentioned.

The faturated carbonat of ammonia (deferibedunder the article Carbonat of Ammonia, and madeby expofing the pungent carbonat to the air forfome hours) produces no precipitate whateverwith muriat of magnolia, owing to the exccfsof carbonic acid, till this excefs is driven off byheat.

Muriat of magnelia is compofed. according toBergman, of 41 of magnefia, 34 of acid, and25 of water. It is very foluble in alcohol.

Ammoniaco Magnesian Muriat.

This fait has been particularly deferibed byFourcroy, a in a valuable memoir on the triplernagnefian falts, of which the following are theleading fafls : 144 grains of carbonat of mag-nolia (containing 50 grains of magnefia) weredifl'olved in muriatic acid, to which was added72. grains of liquid ammonia, which caufed aprecipitate which, collected, walhed and dried,weighed 3J grains. Seventy-two grains moreof ammonia were added, which gave a furtherprecipitate of 7 grains, though the former fuper-natant liquor was ftrongly ammoniacal. Anotherdofe of 144 grains of ammonia gave a furtherprecipitate of 14 grains, after which no further

Ann. Chem. tom. .j.