Metals. MINERALOGY. Metals. 489 
fpar, from the Tides of which the pure filver ifl'ues in the 
form of curled hair. Fig. 8 is an ore of white filver with 
beautiful cryltals and capillary filver. The entire mafs 
is a white ore in horn-ftone mixed with quartz and fpar. 
The cryltals are tranfparent, in part green, of different 
fizes, but all hexagonal. At the bale of the cryltals ap¬ 
pear a number of curled filaments; thefe are native ca¬ 
pillary filver. Fig. 9 is a red ore of filver, wherein (what 
rarely happens) the filver appears in cryllalline cubes, 
femi-tranfparent, red, and as bright as a garnet; found 
in the mines of Annaberg, adhering to an emerald fiuor 
as to a matrix. Similar ores occur in the mines of Mifnia. 
Hydrargyrum, Quickfilver, or Mercury.—Of a fil- 
very-white colour, becoming blacker in the air; always 
in a Hate of fluidity in the common temperature of the 
air, but freezing fo as to become folid and malleable at a 
temperature of—39 ; fpecific gravity, 13’568 : evaporating 
in a low heat: foluble in moll acids, and imparting no 
colour to the folution; when dilfoived in muriatic acid 
and mixed with lime-water, precipitating an orange-red 
powder. 
1. Hydrargyrum virgineum, or native mercury: pure, 
fluid, very ponderous, of a filvery colour and lultre. Found 
in the quickfilver-mines near Saldberg in Sweden, at Al- 
maden in Spain, Idriain Bohemia, in the Palatinate near 
Wolfftein and Moersfeld, in the duchy of Deux Ponts, 
and on Mount Stahlberg, See. in fmall globules fcattered 
through different kinds of ftones, clays, and ores, and 
may be eafily extrafted by evaporation. See the article 
Chemistry, vol.iv. p.280-287. 
2. Hydrargyrum amalgama, or amalgam of mercury 
with filver: ponderous, of a filvery colour and lultre; 
rather folid ; evaporating when heated, and leaving pure 
fdver. Found in the mines of Hungary near Zlana, 
near Mofchellanlburg, and on Mount Stahlberg, in the 
duchy of Deux Ponts, and in Sweden; rarely in large 
maffes, imbedded in quartz, hornltone, or fpar, but ge¬ 
nerally running through other ores of quickfilver; fome- 
times in imperfedt cubes, prifms, or pyramids. Colour 
filvery-white or grey, fometimes tarnilhed in an iridelcent 
manner: it is brittle or foft, according to the proportion 
of mercury; but is generally foft enough to bear the im- 
prefiion of the thumb-nail, and when cut with a knife 
gives a creaking noife: when rubbed on gold, it leaves a 
white llreak. Specific gravity, above 10; contains mer¬ 
cury about 64, filver 36. Klaproth. 
3. Hydrargyrum fublimatum, or muriat of mercury: 
without metallic lultre, fubliming almoft entirely before 
the blowpipe in the form of a w'hite fmoke without ful- 
phurous flame or vapours. Found in the mines of Wolf- 
ftein and Moersfeld in the Palatinate, and near Mofchel¬ 
lanlburg in the duchy of Deux Ponts ; in lcales or grains, 
or cryltallized in fmall four-fided prifms, terminated by 
four-fided rhomboidal fummits, or four-fided pyramids 
with the angles truncate. Colour fmoke-grey, yel- 
lowilh-grey, yellowilh-white, lemon-yellow, or greenilh, 
rarely blackilh. The cryltals have a pearly lultre, are 
femi-tranfparent and foft, and have a foliated texture: 
when thrown on red-hot charcoal, they difcover a fmell 
like garlic, and when mixed with lime-water occafion an 
orange-coloured precipitate. It confilts of mercury com¬ 
bined with fulphuric and muriatic acid in various pro¬ 
portions. 
The mild muriat of mercury, or calomel, is a medicine 
in very extenfive ufe. It has been frequently aflerted, 
that, throughout the greater part of India, calomel and 
other mercurial preparations, are unknown to the natives; 
and that the only mode of employing mercury, is by va¬ 
pour or fumigation, which is, however, feldom ufed, ex¬ 
cepting in very fevere cafes. However, in the year 1815, 
Mr. Charles Hatchett, F. R.S. received from a friend, who 
had arrived in England after a refidence of feveral years 
in India, a fubftance which had been brought from Thi¬ 
bet, with an account that it was much employed by the na¬ 
tives as a medicine in venereal cafes. This fubftance was 
white, tranfparent, brittle, and extremely heavy. When 
Vol, XV. No. 1059. 
broken, the fragments had a fibrous appearance, and by 
trituration it became a pale yellow powder. Upon fub- 
je&ing it to various experiments, it was found to confift 
of muriatic acid and mercury in the ufual flute and pro¬ 
portions conftituting calomel. No part of it was foluble 
in boiling water, nor in folution of muriat of ammonia; 
and it might juftly be pronounced equal to the calomel 
commonly found in European (hops. Hence it appears 
that calomel is really prepared and employed in medicine 
by the natives of Thibet. Mr. Hatchett was not able to 
colleiSt any information concerning the procefs of making 
it. An idea of it may, however, be formed, from a paper 
of the Philofophical Tranfaftions for 1789, entitled “ Some 
Account of the Vegetable and Mineral Productions of 
Boutan and Thibet; by Mr. Robert Saunders, furgeon at 
Boglepour in Bengal.” In this paper, Mr. Saunders ob- 
ferves, (p. 100.) “ The people of this happy climate are 
not exempt front the venereal difeafe, which feerns to rage 
with unremitting fury in all climates. It has been long 
a matter of doubt, whether this clifeafe has ever been 
cured by any other fpecific than mercury and its different 
preparations. In defence of the opinion of other fpecifics 
being in ufe, it has always been urged, that the difeafe 
is frequent in many parts of the world, where it could 
not be fuppofed that they were acquainted with quickfil¬ 
ver, and the proper method of preparing it as a medi¬ 
cine. I mult own, that I expedted to have been able 
to have, added one other fpecific for this difeafe to 
our lift in the materia medica, being informed that the 
difeafe was common here, and their method of treating 
it fuccefsful; nor could I allow myfelf to think, they 
were acquainted with the method of preparing quick¬ 
filver, fo as to render it a fafe and efficacious medicine. 
In this, however, I was miftaken. There is one prepara¬ 
tion of mercury in common ufe with them, and made 
after the following manner: A portion of alum, nitre, 
vermilion, and quickfilver, are placed at the bottom of 
an earthen pot, with a fmaller one inverted, put over the 
materials, and well luted to the bottom of a larger pot. 
Over the fmall one, and within the large one, the fuel is 
placed, and the fire continued for about forty minutes. 
A certain quantity of fuel carefully weighed out, is what 
regulates them with refpedl to the degree of heat, as they 
cannot fee the materials during the operation. When 
the veflel is cool, the fmall inverted pot is taken off, and 
the materials colledted for ufe. I attended the whole of 
the procefs, and examined the materials afterwards. The 
quickfilver had been added on by the other ingredients, 
deprived of its metallic form, and rendered a fafe and 
efficacious remedy. This fubftance is the bafis of their 
pills ; two or three of which taken twice a-day, generally 
bring on about the fourth or fifth day a fpitting, which 
is encouraged by continuing the ufe of the pills for a day 
or two longer.” This formula at firft does not leem to 
have any thing to do with the preparation of the muriats 
of mercury; but, when we confider that the nitre of Thi¬ 
bet is probably limilar to the rough nitre of India, which 
commonly contains a large quantity of muriat of fioda, it 
might jultly be fufpedted, that calomel conftitutes a con- 
fiderable part of the produdt obtained by the afore-men¬ 
tioned operation. 
The other muriat of mercury, called the oxymuriat, or 
corrofivefublimate, is alfo ufed in medicine, but not with¬ 
out great precautions, and in very minute quantities, as 
it is a medicine of molt potent operation ; (fee Chemis¬ 
try, p. 287.) There was a very extraordinary man lately 
living in Conftantinople, who was generally known by 
the name of “ Soliman, the eater of fublimate.” He was 
106 years of age, and had feen the following fuccejlion of 
fultans: Achmet III. Ofman, Mahmoud, Muftapha III. 
Abdul Hamed, Selim III. and the prelent fovereign. This 
man, when young, accuftomed himfelf, as the Turks do, 
to fwallow opium; but, having taken by degrees a large 
quantity without producing the defired effedl, he adopted 
the ufe of fublimate, and, for upwards of thirty years, 
had taken a dram, or fixty grains, a-day. He would fome- 
6 I times 
