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adour as the vapour. This liquor is a mixture offulphuric acid, potafh, and hyperoxymuriaticacid, not indeed io pure as when combined withthe potafh but mingled more or lefs with muri-atic and oxymuriatic acids. If this mixture ofhyper oxymuriat of potafh and fulphuric acidbe heated over a lamp or in any other way, bythe time that it has acquired the temperatureof 125° or thereabouts, an exceedingly loudexplofion accompanied by a white and vividflafh takes place, breaking the vefTel in whichthe mixture is contained, and difperfing itsfragments with great violence in every di-rection. If the fulphuric acid inftead of beingconcentrated is diluted with twice or thrice itsweight of water, and the beak of the retortcontaining the materials is dipped in a bafonof water with an inverted jar of the fame placedover it, there will happen a rapid difengage-ment of a yeilowifh gas without rifk of explo-fion on the application of a lighted lamp. Thisgas when it enters the water of the jar will bein part abforbed, forming a weak liquid oxy-muriatic acid mixed with common muriaticacid, and the unabforbed portion will be foundto be oxygen gas. Hence it is evident thathyperoxymuriatic acid cannot be feparated fromits combination with potafh by either ftrongor weak fulphuric acid, without at the fametime undergoing decompofition.

Nitric acid produces nearly the fame pheno-mena with this fait, but in a lefs marked anddiftinCl manner.

Muriatic acid decompofes this fait, butneither the yellow vapour nor the orange-co-loured liquor are produced : by the applicationof a gentle heat an acid gas is liberated which,although not hyperoxymuriatic acid, is confide-rably more oxygenated than oxymuriatic acid:the compofition of this gas is however by nomeans uniform, depending very materially onthe quantity of muriatic acid employed beyondwhat is abfolutely neceflary to the faturation ofthe alkali. The oxymuriatic gas made ufe ofby Mr. Cruiekfhank, in his analyfis of thedydrocarbonats, was thus procured, and con-* r? 5^*5 m uriatic acid, and 43.5 oxygen.

, 1 a ** c » tartareous, and citric acids, are alfo

fias tb- 6 . 0 ^. decom P ofin g tllis fab, but the acidanv of V S lihcratei1 . is lel " s oxygenated than whenr>i...r , *■ le riiree mineral acids is made ufe of.this 1'.l? riC a!K * ar ^ en ' c acids exert no a£lion on

which r if XCept ^ ^ a ®ftance of heat, in*h,ch cafe m U ch oxygen gas is evolved, and

confequently the

acid is lefs oxygenated.

The acid difengaged from hyperoxymuriatof potafh by fulphuric or nitric acids, affetlscombuflible fubftances in the fame manneras common oxymuriatic acid gas does, onlywith more violence and rapidity, 011 account ofits containing a much larger proportion ofoxygen. Thus if a grain of phofphorus at theend of a piece of wire be let down into this acidvapour, it immediately burfls into flame, withdecrepitation, and a kind of explofion: fo inlike manner if a few grains of the hyperoxy-muriat of potafh be put into a wine-glafs, andtwice the weight of ftrong fulphuric acid beadded, and after that a little alcohol, ether, oroil of turpentine be poured in, an immediateand rapid inflammation will take place; thefame effe£l happens with many of the readilycombuflible folids, particularly camphor, rofin,tallow, pitch, and caoutchouc.

So powerful is the action of this highlyoxygenized acid, that it is not deilroyed evenby the prefence of water, though it is in fomedegree impeded and 'modified. Hence arifesa confiderable variety of interefling and verybeautiful experiments, from which we fhallfelefl the two following : s 1. Take a long ale-glafs, put into it a few grains of hyperoxymuriat,and then pour in water to the depth of from twoto three inches; upon the furface of this fluiddrop in a little exprefied vegetable oil, and thenby means of a long flender funnel, with its flemrefling at the bottom of the glafs, pour in fouror five times as much ftrong fulphuric acid ashad been previoufly added of fait, and immedi-ately after withdraw the funnel : the acid andfait will prefently reacl on each other, highlyoxygenized muriatic acid gas will be liberated,which, pairing through the water, enters theoil, and immediately converts it to a black frothyfluid, a multitude of ignited fparks being difen-gaged at the fame time. 2. Take about tengrains of phofphorus and cut it, under water,-into very fmall pieces, then put 20 grains ofhyperoxymuriat into a glafs jar nine or teninches long, and pour in water fufficient to halffill it; drop in the phofphorus, and then add40 or 50 grains of ftrong fulphuric acid, bymeans of a long funnel, as deferibed above.As foon as the hyperoxymuriat begins to bedecompofed, the phofphorus' takes fire, andburns vividly at the bottom of the veflel: onagitating the mixture, ftreams of fire pafsrapidly to the furface. This experiment requiresfome precaution, for the phofphorus is occafio-nally thrown out of the veflel in a flate c£

* Nicholfou's Jouru. 8 t*. I, p. 297 .

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