CHE M I 
extracted it from fulphur ; then he diffolyed it in the ni¬ 
tric and nitro-nujriatic acids, and precipitated by alka¬ 
lis ; he ,obtained precipitates of a lemon or orange co¬ 
lour: with ammoniac, the precipitate is of a dirty yellow. 
For the reduction of this metal, feparate the yellow 
precipitates from the folution by means of acids; make 
a pafteof them with linfeed-oil, which put into a roaft- 
itig-furnace; a black powder is obtained, .which is to be 
put in a crucible, well fecured with charcoal, and ex- 
poled to a ltrong heat. 
This metal is of a dark-grey colour at the furface ; 
■within, it is of a pale-brown ; its Ipecific graviry is 6 - 44. 
It poffelfes a confiderable degree of hardnefs. It is lets 
inclined to fufion than manganefe. DiiTolved in ftrong 
acids, it gives a precipitate with alkalis; with pruffiats, the 
precipitate is of a brow nidi red ; with ammoniacal ful- 
phure, it is obtained of a brownifli yellow'. Tliefe ex¬ 
periments are not very conclufive, becaule the metal has 
never been yet obtained in large quantities; fo that it is 
not eafiy to difcover all its properties. 
Of NICKEL. 
It appears that nickel had been ufed by the Cliinefe, 
before the European difcovery of this metal, lince an 
alloy is known in that country under the name of pak- 
foiid., which contains nickel. Engeltroem difcovered 
that it was a mixture of copper, zink, and nickel; and 
that the proportions of the lalt were various, according 
to the ufe for which is w r as intended ; they make falie 
jewels of it. Hyerne is the firft who wrote of nickel un¬ 
der the name of kupfer-iiickel, or falfe copper, in 1694.. 
Hencker regarded it as a fpecies of cobalt, or arfenic 
mixed with copper. Cramer confidered it alfo as a cop¬ 
per ore. It was not till 1751 that Cronftedt extracted a 
new metal from this fuppofed mixture. Kupfernickel is 
found in Germany, Dauphiny, and the Pyrenees ; alfo at 
St. Sauveur, near Barege, in calcareous done. The dif- 
cove.ry of this metal, then, is due to Cronftedt. Several 
mineralogifts have denied its exiftence, regarding it as a 
mixture.of feveral metallic fubftances ; but Bergman and 
other chemifts have proved, that this fubftance, fo diffi¬ 
cult to obtain pure, poffeffes all theproperties of a metal. 
To obtain pure nickel, the ore is firft to be roafted, to 
feparate the lulphur and arfenic; it changes into a green- 
ifh oxyd; the greener it is, the more nickel it contains, 
according to Bergman and Arfvidfon. Mix the oxyd 
with two or three parts of a black flux ; put the mixture 
into a crucible, cover it with rnuriat of foda, and urge it. 
to fufion with a very ftrong forge-furnace fire. Breaking 
the crucible, there will appear, under the fcoria, which 
are brown, blackilh, andfometimes blue, a button weigh¬ 
ing a tenth, a fifth, or even one half, of the rough ore. 
Still this is far from being pure. Bergman and Arfvid¬ 
fon took peculiar pains in the purification of this metal: 
tliefe chemifts have (hewn that it is impofiible to feparate 
all the iron it may contain ; for fulphur, fulphure of 
potafti, detonation with nitre, folution in the nitric acid 
and in ammoniac, all lucceffively employed by Arfvid¬ 
fon, w'ould not fucceed ; the button ftill continued to be 
attracted by the magnet. Perhaps this property may be¬ 
long to the metal itfelf, lince thepurelt cobalt has a mag¬ 
netic property as ftrong as iron. 
The experiments of La Grange, in the humid way, 
fliew that keepfernickel may be diffolved in nitro-muri- 
atic acid. By diluting the muriatic folution with fix 
parts ot water, a flight precipitation is obtained; fepa¬ 
rate this firft precipitate, add pure carbonat of potafh to 
the liquor, and another precipitate is made, of a blue- 
grey colour; heat the mafs to drive off the excefs of car¬ 
bonic acid, and add pure potafh, the precipitate will then 
be of a light grey. The precipitate being feparated, a 
very alkaline liquor remains; faturate it with muriatic 
acid, and pour on lime-water to excels; a very plentiful 
precipitate will be obtained. 
Vol. IV. No. 195, 
S T R Y. 269 
At prefent, it does not feem poflihle to determine ab- 
folutely the nature of nickel, fince it always participates 
of iron, which contaminates its properties. The follow¬ 
ing defcription of it is colkCted from Bergman, Arfvid¬ 
fon, Cronftedt, and La Grange. Its texture is not plat¬ 
ed, as Cronftedt aflerted, but granulated, as its fraCture 
fhows. It is nine times heavier than water. It is not 
brittle, but, on the contrary, fufficiently duCtile to make 
it a queftion with Bergman, whether lie fhould rank it 
among the metals or femi-metals. It is nearly as difficult 
to melt as forged iron, is extremely fixed in the fire, and 
becomes calcined wdien heated with accefs of air, afford¬ 
ing an oxyd of a green colour, which is deeper in pro¬ 
portion to its purity: Guyton fays this oxyd is fufible 
into glafs. The fluxes and combuftible matters common¬ 
ly ufed in reducing the metals, produce their effieCt with 
this. The aCtion of air and water qn nickel are not 
known: its oxyd, when melted with matters proper to 
form glafs, gives them a hyacinthine colour, more or lefs 
red. The aCtion of lime, magnefia, and the three pure 
alkalis, on nickel, are ftiil unknown. 
Nickel is foluble in all the acids, and communicates 
to them a green colour. Salts, more or lels coloured, 
lome of them in cryftals, may be obtained from tliefe fo- 
lutions; but the properties of thefe falts have not yet 
been examined. 
The oxyd of nickel parti}'- decompofes rnuriat of am¬ 
moniac. This metal combines readily with fulphur by 
fufion ; Cronftedt, who made the experiment, fays alfo, 
that it diffolves in the alkaline fulphures, and produces 
a combination like the yellow ores of copper. Nickel 
unites readily with gold, and renders that metal white 
and brittle. It may be.feparated from the gold by oxyda- 
tion. Nickel melts alfo with platina. Silver melts eafily 
with nickel, without lofing much of its colour or dufti- 
lity. If this mixture be detonated with nitrat of potafti, 
the nickel will be oxydated, and the lilver remain un¬ 
changed. Nickel precipitates filver from its folution in 
nitric acid. Nickel does not amalgamate with mercury. 
In the heat it difengages the mercury from cinnabar, by 
uniting with the lulphur. Nickel unites likewife with 
arfenic. But in general all the properties we have men¬ 
tioned require the teft of frelh experiments. 
Of COBALT. 
Cobalt was employed in manufactories to give a blue 
colour to glafs, long before it was fufpeCted to be a pe¬ 
culiar metal: this was firft difcovered by Brandt, a Swpde: 
It has never yet been found pure and native; but moftly 
oxydated, and united with arfenic, arfenical acid, ful¬ 
phur, iron, &c. 
To affay cobalt ore, it is pounded, waflied, and after¬ 
wards roafted to diffipate the arfenic. The cobalt remains 
in a ftate of black oxyd, more or lefs deep with relpedt 
to colour; this is mixed with three parts of black flux, and 
one part of decrepitated marine fait; fome add one half part 
of rofin. Put the whole into a crucible, which fhould be 
only two-thirds full; place it in a furnace; heat gently 
til] the rofin ceafes to burn ; then ufe the bellows to in- 
creafe the fire by degrees, and bring the crucible to a 
white heat; keep it thus till every thing is perfectly melt¬ 
ed ; let the crucible get cold, then break it, and feparate 
the metallic button from the fcoria, which are always of 
a blue colour. 
It has never been poffible to obtain cobalt in a ftate of 
purity; but Taflaert’s method of treating the cobalt of 
Tunaberg, as inferted in the Annales de Chimie, may 
anfwer for fixing precifely the characters of this metal. 
Having obtained the oxyd of cobalt in a very pure ftate, 
his mode of reducing it is as follows : Take a porcelain 
crucible, which is to be lined with carbon obtained from 
carbonic acid ; put in the oxyd of cobalt, and expofe it 
for an hour and a half to a forge-furnace; let it cool, 
then break it, and a button will be found, of the colour 
3 Z of 
