SUL
SUL
( 365 )
. and highly fuming ; the fecond was of a much
• deeper colour, and not fuming. Thefe wereput into feparate veffels, and into a third waspoured fome liquid hydro-fulphuret of ammonia,made by faturating liquid ammonia with ful-
■ phuretted hydrogen gas, and which did not
• fume. Muriatic acid was then added to each ;and with the firft, namely, that containing thefuming part of the diftilled liquid fulphuret,gave but little fulphuretted hydrogen, andcaufed but little fulphur to precipitate, thougha confiderable quantity of the acid was requiredto faturate it: with the fecond, namely that con-taining the portion of the diftilled liquid whichgave no fumes, more effervefcence was excited,more fulphuretted hydrogen was evolved, andmore fulphur was precipitated : with the third,namely that containing the Ample hydro-ful-phuret of ammonia, much of the gas was givencut, but little or no fulphur was depoiited.Other portions of the fecond and third folutionswere taken, and liquid ammonia was added toeach, which immediately gave them both thefuming property, and rendered the fecond li-quor in every reipedf fimilar to the firft.
It therefore appears that the property offending forth white fumes may exift both in theliquid fulphuret and in the Ample hydro-ful-phuret, and is produced by an excefs of am-monia, which not finding fufficient fulphuror fulphuretted hydrogen to keep it down, isvolatilized in the air, and carries with it partof the fulphuretted hydrogen contained in thefolution. Hence too, when the fuming hydro-fulphuret is digefted with fulphur, it diflolvesa portion, and then lofes its fuming property,as the excefs of ammonia is then engaged by thefulphur. This latter compound (that is, hydro-fulphuret of ammonia, digefted with fulphur tofaturation) has a deep colour and an oily con-fidence, and does not depofit fulphur by anyfurther addition of fulphuretted hydrogen ; andtherefore it is ftriftly a fulphuretted hydro-ful-phuret, or hydrogureVed fulphuret, in the fenfeto which we have limited it in the beginning ofthis article; and an excefs of ammonia wouldconvert it into a compound exactly the fame asthe fuming fulphuret defcribed by Boyle. Thelatter foon lofes its fuming property on expofureto air, after which it ablorbs oxygen like theother fulphurets, and a white fulphur is de-pofited.
Super-sulphuretted Sulphur. Hvdro-guretted Sulphur of Chenevix,-Soufre Hydrogene.Phis is a very curious combination, difcovered
by Berthollet , and confifts fimply of fulphuret-ted hydrogen, with a large excefs of fulphur,and without any alkaline or other bafe. It isprepared by mixing at once a large proportion ofmuriatic acid with liquid fulphuret of potalh,or better, by pouring the fulphuret in lmallportions, into the acid, during which molt ofthe fulphur is precipitated ns ufual, but verylittle effervefcence takes place, and the ful-phuretted hydrogen, inftead of efcaping in agafleous form, unites with a portion of thefulphur, and condenfes with it into a liquid ofthe appearance of oil, which gradually collectsat the bottom of the veffel in which tlip mix-ture is made. This fubftance was firft noticedby Scheele.
When this fuper-fulphuretted hydrogen ismixed with liquid fulphuret of potalh, fulphuris depofited; for, as has been already menti-oned, the liquid fulphuret is capable of com-bining with, and actually abforbs from the newcompound, an additional portion of fulphuret-ted hydrogen, which in confequence abandonsits excefs of fulphur. Another portion of theprecipitated fulphur is alfo furniihed by the li-quid fulphuret during its further faturationwith fulphuretted hydrogen, which in this re-fpedb afts as an acid, as has been before no-ticed. As therefore the portion of fulphurwhich is already united with an alkali is able toabftradl fulphuretted hydrogen from its com-bination with fulphur alone, it is obvious thatthe fuper-fulphuretted hydrogen cannot be pro-duced till there is a fufficient excefs of acid toengage all the alkali, and detach it from thefulphur, which happens when a little of theliquid fulphuret is poured into a larger quantityof acid. The fuddennefs of the decompofition,and denfity of the fluid produced by the copi-ous depofition of fulphur, appear alfo to affiftin forming this lingular compound.
Super-fulphuretted hydrogen may be confi-dered as a compound in which the elafticity ofthe gas is kept down rather than entirely fub-dued, by the folid with which it is condenfedinto chemical union, fo that this union is \'eryflight, and is readily broken in circumftancesat all favourable to the gas refuming its elafti-city. Hence when it is kept in a phial withwater, on the furface of which it fwims, it isconftantly in a ftate of ebullition, and if thephial is uncorked, the whole of the fulphuret-ted hydrogen exhales, and the fulphur returnsto its original ftate, and falls to the bottom ofthe water. 6 Alfo if a little of this liquid betaken in the mouth, it gives a pungent, bitter,.
• Fr&tft,