SUL

SUL

C

Klapr.

Thenard.

Chenev.

41.8 —■

55 - 5 6

— 59.1 Sulphur

58.2 —

44.44

40.9 Oxygen

100.

I GO.

IOO.

It has been ftated by fome chemifts thatphuric acid is capable of combining with anadditional quantity of oxygen, if diftilled flowlywith oxyd of manganefe. This experimentWas however repeated without fuccefs by Vau-quelin and Bouvier; k fulphuric acid and oxy-gen gas came over, acidulous fulphat of man-ganefe remained in the retort, and the ful-phuric -acid on examination did not appear todiffer in the fmalleft circumftance from com-mon reftified acid.

Muriatic acid gas combines readily, and inconfiderable abundance with fulphuric acid;the compound acquires a brownilh tinge, andwhen expofed to the air emits denfe whitefumes of muriatic acid gas, probably mixedwith a little fulphuric acid, as their odour ismore pungent and fuffocating than that of Am-ple muriatic acid.

The nitric and fulphuric acids unite togetherreadily, either by diredt mixture or by addinga little nitre to fulphuric acid. This compoundwhen moderately concentrated has the propertyof diffolving filver without materially adling oncopper; hence it is in confiderable ufe for re-covering the filver from clippings and otherrefufe of the manufadtories of fdver plate.

Sulphuric acid abforbs by agitation a confi-derable quantity of red nitrous vapour, 1 and inconfequence acquires a light blue colour. Themixture when expofed to the air gives out awhite vapour. If water is added the great heatthat is thereby generated caufes a very rapidand copious emiffion of the nitrous vapour, andfulphuric acid and water alone remain behind.

Sulphuric acid thus impregnated with nitrousvapour after a time becomes pearly colourlefs,and then concretes into folid cryftals; in thisftate when dropped into water it acquires agreen colour, and both the cryftals and waterfparkle with the fpontaneous and copious pro-duction of nitrous gas. "When the cryftals areAmply expofed to heat they melt, emit a denfered'fume, and after the nitrous vapour is thusdriven off, the refidue is common fulphuricacid.

None of the'Ample combuftibles appear tohave any a£fion on fulphuric acid at the com-mon temperature, but at a high heat they arek ‘ Ann. Chem. vii. p. 387. 1 Priefl

37 5 )

all'capable of deoxygenating this acid, and re-ducing it to the ftate partly of fulphur, and’partly of fulphurous acid. Thus if fulphurand fulphuric acid are boiled together, the acidtakes up a fmall portion of fulphur, acquiresthereby a yellowilh colour, and the peculiar- 'fuffocating odour of fulphurous acid. In likemanner if fulphuric acid is diftilled off phof-phorus, a large production of fulphurous acidtakes place, and phofphoric acid remains be-hind in the retort. Charcoal in the fame man-ner deoxygenates this acid. The action of hy-drogen upon it is remarkably energetic ; iffome pure fand moiftened with fulphuric acid,be ftrongly heated in an earthen-ware tube, andat the fame time expofed to a ftream of hydro-gen gas, a copious production of fulphur andwater will enfue from a total decompofition of.one part of the acid, and the combination of itsoxygen with the hydrogen ; accompanied alfoby fulphurous acid arifing from an imperfectdecompofition of the other portion of acid.All the common metals except gold andplatina alfo decompofe fulphuric acid at a boil-ing heat; the metal is oxydated and the acid isconverted into the fulphurous. But when anacid fufficiently diluted is made ufe of, thofemetals that have a powerful affinity for oxygendecompofe the water in preference to the acid,whence hydrogen gas is given out, while thofewhofe affinity for oxygen is weaker, as filverand mercury, exert no action either on the acidor water.

Concentrated fulphuric acid, even when cold,'ads in a very ftriking manner on moft kinds ofvegetable and animal matter; if a piece of pa-per or ftraw, for example, be immerfed in ful- -phuric acid, the texture of the ftraw is fpeedilybroken down, it acquires a deep black colour,and is difFufed through the acid in a ftate ofhalf folution. This phenomenon however doesnot take place, as is generally fuppofed, on ac--count of the reaction of the fulphuric acid onthe carbon and hydrogen, producing fulphur-ous acid, but from the ftrong affinity of the-acid for water, in. confequence of which, theoxygen and hydrogen of the vegetable matter,combine together into water, while the carbon 'is precipitated. But of this we ftiaJi treat mere -fully in the article Vegetable Matter.

Sulphuric acid combines with all the metal-lic oxyds, with the alkalies, and all the earthsexcept filex, forming an important genus offalts, called in the reformed nomenclature, S-uf- -phots, which fee.

ley'* Exper. JVfeikod. iii. p- 144 , !■$(>*