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a few drops of potato, or any fait of potato, beadded to the folution, the alkali unites to thefulphat of alumine, ant 1 aln.oft immediately.aquantity of (Comparatively) large hard oftohedralcryltals of alum are depofited. The proportionof potato necefTary to produce a fenfibie quanti-ty ot alum is fo imail, that all the commonfulphunc acid of the {hops will give it; andhence the pure fulphat of alumine muft hemade with rectified fulphuric acid, and verypure alumine.

Sulphat of alumine is infufible in any heat,but when ftrongly urged in the lire, it partswith its acid altogether.

An Acidulous, or Sniper-fulphat of Alumine, isformed by diffolving the latter lalt in fulphuricacid. It is then cryltallizable with itili moredifficulty, and the fait is fenfibly acid andaufterc to the tafte. It depofits cryllals of alumtoil I more readily on adding potato than theneutral fulphat does, as alum is naturally a faitvvith excels of acid.

The fuper-fulphat of alumine maybe reducedto the neutral fulphat by long boiling withalumine, but with difficulty. Neither of thelefalls is ufed.

SULPHURIZED MURIATIC ACID.

Sulphur, when expofed to the long-con-tinued action of oxymuriatic acid, is convertedinto fulphuric acid, as we have already men-tioned; but when the oxygenation of the fulphuris not compleated, the refult is a Angularcompound the properties of which have hithertobeen only examined by Dr. Thomfon. a It isthus prepared : charge a retort with commonhut and o.\yd of manganefe; annex to it aWoulfe’s apparatus, with two or three bottles;put feme dry flowers of fulphur into the fir ftbottle, and into the next fome carbonated pot-alb, to abforb the fuperfluous acid : then pourinto the retort fome concentrated fulphuric acid,and oxymuriatic acid gas will be immediatelyliberated. After the fulphur has been for fametime in contatf with this gas, it will becomemoift and doughy, its colour will change toorange, by degrees it will become more andmore foft, and at length will be refolved intoa red fluid : as foon as this is effected, the pro-cefs muft be flopped.

1 he liquid thus obtained is perfectly clear,.of a colour between fcarlet and crimfpn, by re-medied, and green by tranfmitted light; itsfpecific gravity is— 1.62, and its weight issnore than twice that of the fulphur employed.

• Mich. Journ.

When firft expofed to the air it fmokes like thediftilled muriat of tin, but after a time its fumesare not more copious than thofe from ftrongmuriatic acid. It is very volatile at a moderatetemperature. Its odour refembles that of fea-weed, but is much ftronger, and it affedts theeyes in the lame manner as wood fmoke does.Its tafte is acid, hot and bitter. It changespaper ftained with vegetable blues to red, butnot very rapidly, unlefs water is added.

If a drop of fulphurized muriatic acid be letfall into a glafs of water, the furface is imme-diately covered with a thin film of fulphur, anda greenift red globule falls to, the bottom, whichremains for fome time like a drop of oil, but isat length converted into acid flakes, of a yellowcolour, which are very dudlile, even after longexpofure to the air. A fimilar yellow matter isprecipitated from the fulphurized muriatic acid,on the addition of a weak folution of potato :this matter is hot to the tafte, and adheres tothe finger like thick oil paint. By digeftion inhot water it is converted into common fulphur,and the water becomes acidulous from the pre-fence of muriatic and fulphuric acids. Solidmuriat of barytes, whether cryftallized or infine powder, affords no precipitate with theentire fulphurized acid, whence it appears thatit contains no fulphuric acid ; but this lattermakes its appearance whenever water is added ;it is probable therefore that the whole of thefulphur, when combined with the muriaticacid, is in the ftate of oxyd, but the addition ofwater determines the whole of the oxygen tounite with part of the fulphur, converting itinto fulphuric acid, while the remainder of thefulphur is deoxydated.

If this fulphurized acid is poured into warmnitric acid, a violent effervefcence, accompaniedby a kind of explofion, takes place ; but if it isdropped very to-w!y into cold nitric acid, only amoderate effervefcence takes place. Nitrousgas and oxymuriatic acid gas are evolved, andthe fulphur is acidified.

Sulphurized muriatic acid, even when cold,difloives phcfphorus very readily; no effer-vcfcence happens, and the folution acquires abright amber colour. If this folution is mixedwith cauftic potato, the whole mafs becomesbeautifully luminous, and fulphur in combina-tion with phofphorus is precipitated.

When mixed with alcohol, a violent effer-vefcence enfues, and ether is difengaged.

Nitric acid decompofes this fulphurized acid,without occafioning any precipitate. Sulphur-