316 
of soda, yielded 25 parts of sulphat of lead, 
= 20.2 parts of lead. The liquor thus freed 
from lead was treated with ammonia. The 
precipitate obtained weighed 39 parts. It 
consisted of oxide of iron mixed with oxide 
of arsenic The production of oxymuriatic . 
acid induced Vauquelin to consider the lead 
as in the state of peroxide. 
3. Carbonat of lead was thus analysed: 
One hundred grains were thrown into 200 
grai ns of nitric acid diluted with 300 grains 
of water. It dissolved completely with ef- 
fervescence. The loss of weight was 1 6 
grains. It was equivalent to the carbonic 
acid. The solution, which was colourless, 
was diluted with water, and a cylinder of zinc 
put into it. In 24 hours the lead was preci- 
pitated in the metallic state. It weighed 77 
grains, = 82 grains oxide. If muriatic acid 
is suspected, it may be easily detected, and 
its weight ascertained, by means of nitrat of 
silver. 
4. Sulphat of lead was thus analysed by Kla- 
proth : One hundred grains of the ore, heated 
to redness, lost two grains, which were con- 
sidered as water, it was then mixed with 
400 grains of carbonat of potass, and heated 
to redness in a platinum crucible. The red- 
dish yellow mass thus obtained was digested 
in water, and the whole thrown on a tiltre. 
The oxide of lead thus obtained weighed 72 
grains, it was dissolved in diluted nitric 
acid. One grain of oxide of iron remained 
behind. Into the solution a cylinder of zinc 
was put. The lead thrown down weighed 
6bij grains. The alkaline solution was super- 
saturated with nitric acid, and then treated 
with acetat of barytes. The sulphat of 
barytes obtained weighed 73 grains, which 
Klaproth considers a; indicating 25 grains of 
sulphuric acid. 
5- Phosphat of lead was thus analysed : 
One hundred grains were dissolved in diluted 
nitric acid. Nitrat of silver dropt into the 
solution formed a precipitate weighing 11 
grains, =- 1.7 grains muriatic acid. The so- 
lution was mixed with sulphuric acid. The 
sulphat of lead precipitated weighed 106 
grains, == 78.4 oxide oi lead. The solution 
was freed from sulphuric acid by means of 
nitrat of barytes, and then almost neutralized 
with ammonia. Acetat of lead was then dropt 
in. The phosphat of lead which precipitated 
weighed 82 grains, = 1 8.37 phosphoric acid. 
The solution was now mixed with muriatic 
acid, evaporated to dryness, and the dry 
mass washed in alcohol. The alcohol, when 
evaporated, left a small residue, which dis- 
solved in water, and formed Prussian blue 
with prussiat of potass, It contained about 
.Ay grain of oxide of iron. 
6. Moiybdat of lead was thus analysed by 
Mr. Hatchet. The ore was boiled repeat- 
edlv with sulphuric acid till the acid refused 
to dissolve any more. The solution con- 
tained the molybdic acid. The undissolved 
{ jowder (sulphat of lead) was boiled for an 
lour with carbonat of soda, and then washed. 
Nitric acid now dissolved it, except a little 
silica. The lead was precipitated from this 
solution by sulphuric acid ; after which am- 
monia separated a little oxide of iron. The 
sulphuric acid solution was diluted with 16 
parts of water, and saturated with ammonia; 
a little oxide of iron gradually precipitated. 
The solution was now evaporated to dryness, 
and the mass strongly heated to separate the 
ORES. 
sulphat of ammonia. The residuum repeat- 
edly treated with nitric acid was converted 
into yellow molybdic acid. 
Ores of nickel. Kupfer nickel may be dis- 
solved in nitric acid, by which the greatest 
part of the sulphur will be separated. The 
arsenic may be afterwards precipitated by 
the affusion of water. A plate of iron will 
expel the copper, if any should be present. 
Precipitate by potass added in excess, and 
boil tire precipitate, which will separate the 
arsenic and sulphur completely. Dissolve 
the precipitate (previously exposed moist for 
some time to the air) in acetic acid, and add 
an excess of ammonia. The iron is precipi- 
tated ; but the cobalt and nickel remain in 
solution. Evaporate, and the cobalt is de- 
posited ; then by continuing the evaporation 
to dryness the nickel is obtained. 
Ores of zinc. 1 . Blende may be treated 
with diluted nitric acid, which will separate 
the sulphur, the siliceous gangue, &c. The ■ 
purity of the sulphur is to be ascertained by 
combustion, and the residuum analysed in 
the manner formerly described. Precipitate 
the nitric solution by soda, redissolve in mu- 
riatic acid, precipitate the copper (if any 
should be present) by a plate of iron ; sepa- 
rate the iron by adding an excess of ammo- 
nia. The zinc now only remains in the so- 
lution, which may be obtained bv evaporat- 
ing to dryness, redissolying in muriatic acid, 
and precipitating by soda. 
2. Calamine may be digested in nitric 
acid, noting the loss of weight for carbonic 
acid, and the insoluble residuum boiled with 
muriatic acid repeatedly; what remains after 
dilution with boiling water is silica. The 
nitric solution contains zinc, and probably 
also iron and alumina; evaporate to dryness, 
reckssolve, and add an excess of ammonia. 
'1 lie iron and alumina either remain imdis- 
so'ived or are precipitated, and they may be 
separated by potass. The zinc may be pre- 
cipitated by an acid, or by evaporation to 
dryness. The muriatic solution probably 
contains iron and alumina, which may be 
precipitated by the rules already laid down. 
Ores of antimony. Native antimony was 
thus analysed: One hundred grains were di- 
gested in nitric acid till the whole was con- 
verted into a while powder. When the acid 
emitted no longer any nitrous gas, the mix- 
ture was diluted with water and thrown upon 
afiltre. The solution was then treated with 
nitrat of silver. The precipitate yielded by 
reduction one grain of silver. The prussiat 
of potass threw down from the residuum so- 
lution a precipitate which contained ^ grain 
of iron. The white oxide formed by the ni- 
tric acid was digested in muriatic acid ; the 
whole dissolved and formed a transparent 
solution. It was diluted with six times its 
weight of water, and the precipitate redis- 
solved in muriatic acid, and a cylinder of 
zinc put into it. The antimony obtained 
weighed 98 grains. 
2. Sulphuret of antimony is to be treated 
with nitro-muriatic acid. The sulphur and 
the muriat of silver (if any silver is present) 
will remain. Water precipitates the anti- 
mony ; sulphuric acid, the lead ; and ammo- 
nia the iron. 
3. Klaproth analysed the red ore of anti- 
mony as follows: One hundred grains were 
digested in muriatic acid till the whole dis- 
solved, exeept If grains of sulphur. A little 
sulphuret of antimony rose with the sulphu- 
rated hydrogen gas exhaled, and was depo- 
sjted in the beak of the retort. The solution 
was diluted with water. The whole preci- 
pitated in the slate of a white powder; for 
potass threw nothing from the liquid. The 
powder was redissolved in muriatic acid, au 
excess added, and the solution diluted. A 
plate of iron threw down 67^ grains of anti- 
mony. 1 he ore then contained 78.3 grains 
of oxide of antimony. One hundred grains 
of the ore yielded by solution in muriatic acid 
37 cubic inches of sulphureted hydrogen gas. 
From tins, Klaproth concluded that it con- 
tained 20 grains of sulphur. 
Ores of bismuth. Native bismuth maybe 
treated witli nitric acid. Repeated concen- 
trations and affusions of water precipitate the 
bismuth, and perhaps the arsenic; but this 
last may be redissolved in boiling w aler. 
I he cobalt. remains, and may be examined 
by the rules to be hereafter laid down. T he 
same analysis succeeds with the other ores 
of bismuth. The sulphur when present re- 
mains undissolved. 
4\ e shall give as an example of these ores 
Klaproth’s analysis or a sulphuret of bismuth. 
I I ifty grains ot the ore were digested in nitric 
acid. 1 lie whole w:as dissolved except 
grains ot sulphur. r l he solution being diluted 
with water, a white powder precipitated. 
1 he iiitred solution was treated with com- 
mon salt ; at first it produced no change,, j 
but by and by the whole became milky. 
The precipitate consisted, like the last, of ox- 
ide oi bismuth. 1 he solution continuing. I 
clear tor some time, indicated that no silver ] 
was present. Ihe vvlnte precipitate was not 
altered by exposure to thq light; an addi- 
tional proof that no silver was present. 
Ores of tellurium. Klaproth dissolved 
the white gold ore of Fatzbay in nitro-muri- j 
atic acid, and added potass in excess to the ! 
solution. A brown precipitate remained iin- 
dissolved, which was a mixture of gold and 
iron. It w^as redissolved in nitro-muriatic 
acid, the gold tirst precipitated by nitrat of 
mercury, and then the iron by potass. The 
potass in the tirst solution being saturated j 
with muriatic acid, the oxide ot tellurium j 
precipitated. 
The other ores may be analysed in the ] 
same manner; only the precipitate occasion- ] 
ed by the pota SS must be treated accord. ng 
to the metals of which it consists. The rules J 
have been already laid down. 
Ores oj arsenic. Native arsenic may be 1 
treated with nitro-muriatic acid. The silver ] 
and gold remain; the first in the state of a 1 
muriat; the second may be dissolved by 1 
means of nitro-muriatic acid, and pretipi- 1 
tated by sulphat of iron. The arsenic may ] 
be precipitated by concentrating the nitric ] 
solution, and then diluting with water. The I 
iron may then be precipitated by ammonia. 
2. The sulphureted ores of arsenic may | 
likewise be treated with diluted nitro-muri- ] 
atic acid. The sulphur remains undissolved; j 
the arsenic may be precipitated by concern- 
tration and the affusion of water ; the iron by 
ammonia. 
3. Oxide of arsenic may be dissolved in 1 
sixteen parts of water. The solution displays 
acid properties, and nitrat of silver and of 
mercury occasion precipitates in it 
