MER

MER

C S8 )

former to about 14.5 of the latter. This refultwas obtained by decompofing cinnabar by meansof reguline antimony, a method in fome refpe&spreferable to the more ufual one by iron filings,efpecially on account of the ready fufibility ofthe fulphuret of antimony.

Some attempts have been made to preparecinnabar by fubllituting the oxyds and even thefalts of mercury to the fimple metal, but forthe molt part with no improvement in thecolour of the cinnabar, and at the imminenthazard of cccafioning a violent explofion.Bayen was the firft chemift who obferved thefulminating property of the oxyds of mercurywhen heated with fulphur, and thefe mixtureshave hence received the name of Bayen’s fulmi-nating mercury. The moft powerful of thefemixtures is thus prepared : y to a folution ofnitrat of mercury add limewater, as long as anyprecipitate falls down, decant the clear liquorand wafh the pulverulent oxyd with repeatedportions of water, after which dry it on awater bath, and then grind it carefully in a mor-tar, with \ of its weight of flowers of fulphur.This powder when laid on a hot iron explodeswith confiderable force, no doubt in confequenceof the fudden deoxydation of the mercury andthe rapid combuftion of part of the fulphur:for if it is performed in a clofe veffel to preventthe diffipation of the powder, the refult of itsdeeompofition will be a reddifh violet colouredfulphuret, fimilar to that procured in the ufualmanner. Corrofive muriat of mercury rubbedup with the fulphur produces in like manner aviolently explofive compound, while on theother hand calomel and fulphur afford by drydiftillation cinnabar and corrofive muriat with-out any explofion; the- reafon of which is thatthe calomel divides itfelf into two portions, ofwhich one is converted into cinnabar by com-bining with the fulphur and letting go its oxy-gen and muriatic acid, which bejng abforbed bythe other portion of calomel, convert it intocorrofive fublimate.

Sometimes cinnabar is prepared in the labo-ratory, though not in the large way, from cor-rofive fublimate and fulphuret of antimony, bydiftilling them together in the proportion ofthree of the former to one of the lattev : in thiscafe a double deeompofition takes place ; theoxygen and muriatic acid of the mercurial faitcombine with the antimony, while the fulphurof this laft unites with the mercury: henceduring the procefs the products appear in thefollowing order ; firlt, the corrofive muriat, or

y 'Sage Elcm. de Mineral, ii. p.

butter, of antimony, paffes into the receiver,then fome undecompofed corrofive fublimatemakes its appearance, and laftly, at a red heat,the cinnabar rifes and attaches itfelf to the neckof the retort.

The a£tion of mercury and its oxyds in themoiil way upon the alkaline fulphurets, hydro-fulphurets, and liydroguretted fulphurets, isvery llriking, and has received much attentionfrom various chemifts, though from the naturalintricacy of the inquiry many difficulties yetremain to be cleared up.

It was an obfervation by Schultz, 2 in theGerman Ephemerides , that firft of all we be-lieve attracted the attention of chemifts to thisfubject. He obferves that if 36 grains of mer-cury be put into an ounce vial, with half an ounceof Boyle’s fuming liquor, for a few days, and isfrequently fhaken during the interval and occa-fionally expofed to a gentle heat, the mercurywill become at firft black, and after a while willbe wholly changed into cinnabar; when thishas taken place, the fupernatant liquor will befound to have loft its odour and colour, andwill be covered with a faline pellicle.- Hoffmanand Wiegleb verified this obfervation and fup-ported it by fome new experiments, to whichBeaume foon after made fome very valuableadditions. He put into a vial fome mercurywith .twice its weight of volatile liver of fulphur ;upon agitating the mixture the mercury wasimmediately converted into a black powder,which three days after was found to have affumedthe appearance of cinnabar, and cryftallized inthick and very fhort prifms. 2. Sulphat ofmercury being mixed with volatile liver of ful-phur, a confiderable heat and ebullition wasproduced, and the mercury became black ; threedays after, the fupernatant liquor now colourlefswas poured off, .and a freftt portion of liquidfulphuret was added, in the fpace of two daysmore the precipitate was changed into cinnabar.3. To a folution of nitrated mercury volatileliver of fulphur was added as in the formercafes, a confiderable heat was produced and acopious black precipitate fell down, which in thefpace of a week had acquired a brick colour;the clear liquor was then poured off, and re-placed by a frefh quantity of ammoniacal fulphu-ret, by which in the fpace of a few hours thecolour of the precipitate was raifed to a brightfcarlet, fully equal to that of the heft fublimedcinnabar. 4. A mercurial ethiops was madein the ufual way by melting together four partsof mercury and one of fulphur, this was pul-

58. * Coll. Acad. vi. p. 30,