27 4 C H E M 
and red. If fulphure of potafli, or hydro-fulphure, be 
poured into a folution of nitrat of bifmuth, precipitated 
by water, the oxyd is changed from white to a deep black. 
The magiftery of bifmuth fhouidbe very white and corn- 
pad. 
The muriatic acid aCts with difficulty on this metal. 
It is neceflary that the acid fhould be very concentrated, 
and be kept in digellion on the bifmuth for a long time ; 
the folution fucceeds llill better, when a large quantity 
«f muriatic acid is diftilled from the metal. The mix¬ 
ture has a fetid fmell ; the refidue is to be walhed with 
water, which becomes charged with a portion of the me¬ 
tallic oxyd united to the acid. The muriat of bifmuth 
cryltallizes with difficulty; it may be fublimed into a 
kind of foft fait, improperly called butter of bifmuth \ it 
Ifrcngly attracts the humidity of the air; and, laftly, 
water decompofes it, and precipitates it in the form of a 
■white oxyd. The nitro-muriatic acid dilfolves bifmuth 
alfo; the folution is at firft greenilh, but afterwards it 
grows white. 
Bifmuth makes no detonation with nitre ; yet that fait 
converts it into an oxyd. Bifmuth in powder, mixed 
with the fuper-oxygenated muriat of potafli, detonates 
with a blow. Muriat of ammoniac is decompofed by the 
oxyd of bifmuth, but not by the metal ; the produCt is 
what was formerly called bifmiitbical flowers of fed ammo¬ 
niac, and a large quantity of ammoniacai gas is difen- 
gaged. Mix together one part of the oxyd of bifmuth, 
and two parts of muriat of ammoniac ; put the mixture 
into a glafs retort, and proceed to dillillation with the 
pneumatic apparatus : fome ammoniac pafles over; and 
a little oxyd of bifmuth mixed with undecompofed mu¬ 
riat of ammoniac, rifes and flicks to the neck of the re¬ 
tort; the refidue is a combination of the metallic oxyd 
with the muriatic acid: The oxyd of bifmuth may be 
leparated from the muriat of ammoniac by Ample folu¬ 
tion in water. 
Bifmuth unites, by means of fluxes, with gold, and 
forms with it a pale, brittle, heavy mafs. When this 
mafs is expofed in an open fire, tire bifmuth is oxydated, 
and leaves the gold unchanged. Bifmuth precipitates 
gold from its folution in aqua regia. Platina melts with 
bifmuth, and the mixture becomes fufible in proportion 
to the quantity of bifmuth which it contains. The bif¬ 
muth is oxydated by expofure to an open fire, but it is 
difficult to leparate it completely from the platina, for the 
mixture becomes infoluble in proportion as it is lepa- 
rated. Bifmuth precipitates platina from its folution in 
aqua regia. Bifmuth unites eafily with filver, which 
becomes brittle, and lofes its brilliancy. By expofing 
the mixture in an open fire, the bifmuth is vitrified, and 
the filver left unchanged. Bifmuth precipitates filver 
from its folution in nitric acid, firft in its metallic ftate, 
and at lalt in the form of an oxyd. Bifmuth amalga¬ 
mates eafily with mercury, and is often uled to adulte¬ 
rate that fluid. It is difficult to feparate the bifmuth 
again, even by diftillation and filtration through leather. 
Mercury diflolved in nitric or fulphuric acid is precipi¬ 
tated in its metallic ftate by bifmuth. If three parts of 
bifmuth and feven of oxygenated muriat of mercury be 
diftilled together, a butter of bifmuth will be formed, 
and the mercury will pafs over in a fluid ftate into the 
receiver. By the afliftance of heat, bifmuth feparates the 
mercury alfo in a fluid ftate from cinnabar. The refult 
is a fulphure of bifmuth. Lead unites eafily by fluxes 
with bifmuth, and by this union becomes harder, more 
brittle, and more fufible. Thefe metals may be fepa- 
rated from each other by folution in aqua-fords, and 
dilution with water; for the water precipitates the oxyd 
of bifmuth, and leaves the lead in combination with the 
acid. Lead precipitates bifmuth from its folution in 
acids. The lead has alfo a ftronger affinity in the dry 
way for fuiphur, and feparates it from the fulphure of 
bifmuth. 
Bifmuth may be ufed for making a fympathetic ink. 
a 
S T R Y. 
Any of the folutions of bifmuth'will do; but we fliould 
choofe in preference an acid which will not corrode the 
paper, as the acetit of bifmuth. Write the characters on 
the paper, and they will be invifible ; to make them ap-- 
pear, take an alkaline fulphure, (the fulphure of am¬ 
moniac in preference;) putting this in contaCt with the 
paper, the vapour difoxygenates the bifmuth, and black¬ 
ens it, forming a fulphure of bifmuth. The experiment 
may be made by putting the fulphure of ammoniac in a 
glafs, and inverting the paper over it; the vapours of 
the fulphure will rile, and foor, render the characters vi- 
fible. Bifmuth is employed by the pewterers to commu¬ 
nicate hardnels to tin. It may be lubliituted inltead of 
lead, in the art of cupelling the perfeCt metals, becaule, 
like that metal, it has the property of flowing into a glafs, 
which is abforbed by the cupels. Geoffrey the younger 
has obferved and recorded many circumftances in which 
this brittle metal refembles lead. The eftecis of bifmuth 
on the animal economy can only be conjectured; but 
there is reafon to think that its ufe, like that of lead, 
would be dangerous; and there are fome inftances of 
bad effeCts-ariling from the external ufe of this metal. 
We have already oblerved, that the oxyd of bifmuth is 
ufed as a pigment for the Ikin, and that ftrong duelling 
matters alter its colour; Inch finells as are fetid more 
particularly produce this effeCt. The vicinity of flaugh- 
ter-houfes, of common fewers, and alrnoft every other 
itrong fmell, has that effeCt onthis oxyd, and caules its 
colour to become more or leli*> black; and hence it in¬ 
jures the tkin. The vapour of alkaline lulphures, or the 
fmell of eggs, produce this eil'eCt quickly. A very com¬ 
mon experiment in natural philolophy. thews this proper- 
ty in a linking manner. If characters be written with a 
lolution of bilmuth on the firft page of a book of fifty 
leaves, and the lalt page be impregnated with a final! 
quantity of the liquid alkaline fulphures, a fiiort 
time afterwards, the hepatic vapour carried by the air, 
which circulates between all the leaves, arrives at the 
other extremity of the book, and converts the colourlefs 
characters marked even on the firft page, into a deep 
brown. It is affirmed, that the fulphurated hydrogen, 
or hepatic gas, pafles through the paper; but Monge 
has proved, that it is the air which carries it in this man¬ 
ner, from one leaf to another, fince the erfect does not 
take place, when the leaves are glued together. 
Of ANTIMONY. 
The Latins called this metal flibium : it was firft called 
antimonium , or antimony, in England, from its having 
been given to fome monks , as a purgative. The prior of 
a monaftery at Canterbury had given fome of it to his 
hogs, and he found that it purged them and increaled their 
appetite; heeflaved to do as much by his monks, a lazy 
crew, who were often ill, and loft their appetites for 
want of exercile ; but the greater part of them died. 
No metal has given lo much employment to alchemifts, 
and volumes have been written upon it. Alchemifts 
have given it various names, as root of metals , fugar of 
lead , &c. 
To feparate the antimony from its gangue, and other 
metallic matters with which it may be mixed, two 
earthen pots are taken, one of which is pierced at the 
bottom in many places; into this the ore is put; ano¬ 
ther pot, placed below the firft, for the purpofe of re¬ 
ceiving the fulphure of antimony in proportion as it 
melts, being funk in the earth. A fire is then made 
round the fuperior-pot, fo as to produce gentle heat at 
the beginning, becaule the antimony is very fufible; 
but towards the end the heat is railed,- that the whoie of 
the antimony contained in the mineral may be melted 
out. The Icoriae remain in the upper pot. This fub- 
Itance is of a blackilli grey colour,, in thin plates, or 
needles of different lizes, and friable. 
To obtain the oxyd of antimony from the native ful- 
phtu'e, break the fulphure into finall pieces, and expole 
it 
