317 
ORE 
Ores of cobalt. White cobalt ore was 
thus analysed by Tassaert. Jo ascertain 
the proportion ot arsenic he treated the ore 
with diluted nitric acid, and obtained a com- 
plete solution. Crystals of white oxide of 
arsenic were deposited, and uy repeated eva- 
porations he separated the whole of the arse- 
nic, and ascertained its weight. 1 Ie then 
boiled a new portion of the ore with lour 
times its weight oi nitric acid, and thus aci- 
dified the arsenic, and obtained a solution. 
This solution was treated with potass, which 
retained the arsenic acid, aud separated the 
other bodies. A precipitate of arsemat ot 
cobalt, which had fallen when the nitric solu- 
tion was diluted with water, was treated with 
potass for the same reason. The residuum, 
together with the precipitate occasioned bv 
the potass, was dissolved in nitric acid, and 
ammonia added in excess. Part was retained 
in solution by the ammonia; but part was 
precipitated. 1 he precipitate was dissolved 
in acetic acid, and the solution repeatedly 
evaporated to dryness. By this piocess the 
oxide of iron gradually separated in the form 
of a red powder. r l he dissolved part was 
acetat of cobalt. It was decomposed by the 
addition of ammonia in excess, which redis- 
solved the cobalt. By these pioeesses the 
arsenic and iron were separated ; the cobalt 
was retained by the ammonia, and was ob- 
tained by evaporation. to ascertain the 
proportion of sulphur in the ore a new por- 
tion was boiled with nitric acid. On cooling, 
crystals of white' oxide of arsenic vyere de- 
posited. These being separated, nitr.it ot 
barytes was added to the solution ; 100 paits 
of the dried precipitate indicated Id. 5 or 
sulphur. 
ORE 
0 R G 
The other ores of cobalt may be analysed 
nearly in the same way. 
Ores of manganese. 1. Barytated manga- 
nese was treated by Vauqueiin with muriatic 
acid; oxymuriatic gas passed over, and the 
whole was dissolved except a little cnaicoal 
and silica. The solution when evaporated 
yielded crystals ot muriat of barytes. I hese 
were separated ; and the liquid, evaporated 
to dryness, yielded a yellow mass soluble in 
alcohol, and tinging its tiame with yellow bril- 
liant sparks. The proportion of barytes was 
ascertained by precipitating it in tire state of 
a sulphat ; the manganese, by precipitating 
it by carbonat of potass. 
2. The grey ore of manganese was treated 
by the same chemist with muriatic acid, 
some silica remained undissolved. Carbonat 
of potass was added to the solution. I he 
precipitate was at iirst white, but became 
black when exposed to the air. It was treated 
with nitric acid, which dissolved every thing 
but the manganese and iron (it a>iv had been 
present). The nitric solution, when mixed 
with caibonat of potass, deposited only car- 
bonat of lime. The black residuum was 
mixed with sugar, and treated with nitric 
acid. The solution was complete ; therefore 
no iron was present. 
The same processes will succeed with the 
other ores of manganese. When iron is pre- 
sent, it may be separated either as above, or 
bv the rules laid down in the first section ; or 
what succeeds better, we may dissolve the 
mixture in acetic acid, and evaporate to diy- 
ness two or three times repeatedly. The 
oxide of iron is left behind, while the acetat 
of manganese continues soluble in watei . 
Ores of tungsten. Wolfram was analysed 
pearl v as follows*. The ore was boiled with 
muriatic acid, and then digested with ammo- 
nia alternately til! the whole was dissolved 
The ammoniacal solutions being evaporated 
to drvness and calcined, left the yellow oxide 
of tungsten in a state, ot purity. 1 he muriatic, 
solutions were mixed with sulphuric acid, 
evaporated to dryness, and the residuum re- 
dissolved in water. A little silica remained. 
Caibonat of potass precipitated a brown 
powder from this solution. 1 ins pov del was 
treated with boiling nitric acid repeatedly, 
till the iron which it contained was oxidized 
to a maximum. It was then digested in 
acetic acid, which dissolved the manganese, 
and left the iron. Finally, the manganese 
was precipitated bv an alkali. 
Tun<»stat of lime was thus analysed by 
Klaproth : One hundred grains of it were 
digested in nitric acid. The yellow-coloured 
residue was washed and digested in ammonia. 
The residue was digested in nitric acid and 
ammonia alternately, till a complete solution 
was obtained. Two grains ot silica lemaine 
behind. The nitric acid solution was mixed 
with ammonia, but no precipitate appeal ei . 
It was then mixed with a boiling solution o 
[ carbonat of soda. The precipitate dried 
! weighed 33 grains. It was carbonat of lime; 
| but when redissolved in nitric acid, it left one 
l grain of silica. Thirty -two grains of caibo- 
i nat are equivalent to 17.6 ot lime. 1 lie am- 
j mouiacal solution, by evaporation yielded 
| small needleform crystals. V hen heated to 
' redness in a platinum cruible, they left 
grains of oxide of tungsten. 
Ores of moli/bdeitum. Molybdena may 
be treated with nitric acid successively boil- 
ed upon it till it is converted into a white 
powder. This powder, washed and dried, is 
molvbdic acid. The liquid obtained by wash- 
ing the acid, on the addition of potass, depo- 
sits some more molvbdic acid. 1 his being 
separated, muriat ot barytes is to be dropt 
into it as long as any precipitate appears. 
One. hundred parts of this precipitate indi- 
cate 1 4.5 ot sulphur, . ,, 
Ores of uranium. 1. Pechb ende or the 
black ore of uranium, was dissolved by Kla- 
proth in nitric acid. The undissolved part is 
a mixture of silica and sulphur. By evapo- 
ration the solution, nitrat ot lead was preci- 
pitated; then nitrated uranium in crystals. 
The solution being now evaporated to drv- 
ness, 'and treated again with nitric acid, left 
the iron in the state ot red oxide. 
2. Uranitic ochre may be treated with 
nitric acid, which dissolves the uranium, and 
leaves the iron. The purity of the iron may 
be tried by the rules already laid down. 
3 Green mica was dissolved by Klaproth 
in nitric acid, and ammonia added in excess 
to the solution. The oxide of uranium was 
rlatic acid. White oxide of titanium preci- 
pitates. Separate the precipitate, and eva- 
porate the solution to dryness. Redissoive 
the residuum in water, lhe silica remains 
behind. Precipitate the solution by an al- 
kali ; add the precipitate to the white oxide 
obtained at first, aud dissolve the whole m 
sulphuric acid. From this solution phospho- 
ric acid precipitates the titanium, but leaves 
the iron. _ . , 
The third species, which contains lime and 
no iron, is to be fused with potass, dissolved 
in muriatic acid, and the silica separated in 
the usual way. After this the titanium is first 
to Ire separated from the muriatic solution bv 
ammonia ; and afterwards the hme by an al- 
kaline carbonat. 
Ores of chromium. Vauquelin analysed 
the chromat of lead in the following manner : 
When boiled with a sufficient quantity ot cai - 
bonat of potass, a lively effervescence takes 
place; the acid combmes with the potass, 
and the carbonat of lead is formed, and re- 
mains undissolved. It may be dissolved in 
nitric acid, and its quantity ascertained by 
precipitation with sulphuric acid. Or the 
chromat mav be treated with muriatic acid,; 
muriat of lead precipitates, and chromic acid 
remains in solution. This process must be 
repeated till the whole of the ore is decom- 
posed. There remains in solution chromic 
acid mixed with a little muriatic, which may 
be separated by means of oxide of silver. 
ORGAN, in general, is an instrument or 
machine designed for the production ot some 
certain action or operation; in which sense 
the mechanic powers, machines, and even 
the veins, arteries, nerves, muscles, and 
bones of the human body, may be called or- 
precipitated ; that of copper retained. 
Ores of titanium, lhe ores ol titanium, 
reduced as usual to a fine powder are to be 
fused with potass or its carbonat. I he melted 
mass is then to be dissolved in hot water. A 
white precipitate gradually separates, which 
is the white oxide of titanium, this is all 
that is necessary to analyse the first species. 
But when iron and silica are present, the fol- 
lowing method of Cheneyix may be adopt- 
ed : Saturate the alkaline solution with mu- 
The organs of sense are those parts of the 
body by which we receive the impressions or 
idea's of external objects, being commonly 
reckoned live, viz. the eye, ear, nose, palate, 
and cutis. 
Organ, a wind-instrument blown by 
bellows, and containing numerous pipes of 
various kinds and dimensions, and multifa- 
rious tones and powers. Ot all musical in- 
sruments this is the most proper for the sa- 
cred purpose to which it is most generally 
applied in all countries wherever it has been 
introduced. Its structure is lofty, elegant, 
aud majestic ;. and its solemnity, grandeur, 
and rich volume of tone, have justly obtained 
it an acknowledged pre-eminence over every 
other instrument. 
An organ, when complete, is of threefold 
construction, aud furnished with three sets ot 
keys ; one for what is c alled the great organ, 
and which is the middle set , a second (or 
lower set) lor the choir organ; and a thii d 
(or upper set) for the swell. In the great 
organ, the principal stops are the two diapa- 
sons, the principal, the twelfth, the filter nth, 
the sesquialtra, the mixture or furniture^ the 
trumpet, the clarion, aud the cornet. I he 
chdir organ usually contains the stopt diapa- 
son, the dulciana, the principal, the flute, 
the twelfth, the bassoon, and the vox bu- 
rn, ana. The swell comprises the two diapa- 
sons, the principal, the hautboy, trumpet, 
and cornet. Besides the complete organ, 
there are other organs of lesser sizes, and 
more limited powers, adapted to church, 
chapel, and chamber use. There is also ths 
