ME R

ME R

( S5 )

A hundred parts of calomel therefore containMercury 79 1 8 8. SOxygen 9.5/

Muriatic acid x 1.5

100.0

A hundred parts of corrofive muriat containMercury 69.7 \ gOxygen 12.3 j

Muriatic acid 18

100.

Mr. Chenevix in afcertaining that corrofivefublimate was not oxymuriat of mercury, butmerely muriat of mercury highly oxydated, hasdifcovered a fait which is truly the oxymuriatof this metal. By palling a current of oxymu-riatic gas through water in which, there wasfome red oxyd of mercury, after a time thered oxyd became of a very dark brown colour,and part of it was difiolved. The liquor wasthen evaporated nearly to drynefs and a mixedfait was obtained, confifting partly of corrofivemuriat, and partly of another fait which cryftal-lized later than the former, and on being re-diflolv-ed and cryftallized appeared neatly pure.This fait has not been much examined, but itpofleffes the eflential quality of an oxymuriat ingiving out vapours of oxymuriatic acid by thealfufion of the fulphuric or any Itronger acid.

The action of moll of the other acids onmercury has been examined, but few of the faltsare interefting.

The acetous acid has no action on mercury,but if boiled on its oxyds it difl'olves them,though with difficulty. But the bell and molleffectual way of making the acetited mercury isby the double decompofition of nitrated mercuryand acetited potalh. For this purpofe take 3ounces of mercury/ diffolve it in about 4-| oz.of nitric acid or a little more than is fufficientfor folution without heat. Mix this with 3 oz.of acetite of potalh previoufly diflblved in 8pounds of boiling water and fet the whole-afideto cryftaliize, which takes place as the liquorcools, and the acetited mercury then feparatesin the form of fine loft micaceous cryilallineplates, very light and fpungy. Then waih themwitn cold water and dry them by palling betweenfolds of blotting paper.

In preparing this fait it is eflential to pourthe mercurial folution into the acetite, other-

wife part of the nitrat of mercury would bedecompofed by the mere water of the iolution,and an infoluble fub-nitrat would be mixed withthe acetite. The quantity of water of folutionhere directed is fufficient to difl'olve, whenboiling, both the acetite of mercury and thenitrat of potalh; but the procefs fucceeds asweil if only a few ounces of water are ufed,fufficient to difl'olve the new formed nitrat ofpotalh, in which cafe the whole acetite ofmercury is precipitated and may be feparatedand fubfequently rediffolved and cryftallized.Neither is it neceflary to ufe the cryftallizedacetite of potalh, diftilled vinegar nearly fatc-rated with potalh anfwering all the purpofe.

Acetited mercury is fcarcely foluble in coldwater, but readily difl'olves as the heat is raifed.The dry fait is eafily decompofed by heat.

lhe carbonic acid only unites with mercurywhen an acid folution is precipitated by a car-bonated alkali. The carbonated oxyds are whiteand remain fo unaltered by the air.

The boracic acid may be made to unitewith mercury in the fame way as the acetousacid, that is by double decompofition. Forthis purpofe common borax mull firll be neu-tralized with its own acid, then diflblved inwater, and nitrated mercury poured into it.The borat of mercury partly feparates on thefirll mixture of the liquor, and more may beobtained by evaporation. This fait is in theform of brilliant feales, which grow yellow byexpofure to air.

The phofphat of mercury is formed in thefame way as the laft, by adding nitrat ofmercury to an alkaline phofphat. A whiteprecipitate is formed which is phofphat ofmercury nearly infoluble.

When the nitrat of mercury is decompofed -by alcohol, a very lingular powder is produced,which appears to be the oxalat of this metal,and pofleffes a moll aftoniffiing power of ex-plofion when kindled, as difcovered by Mr.Howard. This fulminating mercury will bedeferibed in the next article.

None of the alkalies have any action uponmercury, but the fixed alkalies diifolve itsoxyds. Thefe combinations have been butlittle examined.

Ammonia added to any of the mercurialoxyds immediately blackens them, caufes thedifengngement of azotic gas, and reduces themnearly to the metallic Hate. Fourcroy alfoaflerts that another aftion takes place,, namely,the production of a quantity of nitric acid by.

• I'liarm. Edinb.