IRON. 
separation of the scoriae. After the mass is 
cooled, the antimony is found separate at 
the bottom of the crucible, while the iron 
remains in combination with the sulphur 
and alkali. If the proportion of the iron be 
considerably greater than five ounces to the 
pound of ore, the antimony will be alloyed 
with iron. Manganese is almost always 
united with iron in the native state. Tung- 
sten forms a brittle, whitish-brown, hard 
alloy, of a compact texture, when fused 
with white crude iron. The habitudes of 
iron with molybdena are not known. 
Iron is the most diffused, and the most 
abundant, of metallic substances. Few mi- 
neral bodies or stones are without an ad- 
mixture of this metal. Sands, clays, and 
the waters of rivers, springs, rain, or snow, 
are scarcely ever perfectly free from it. 
The parts of animal and vegetable sub- 
stances likewise afford iron in the residues 
they leave after incineration. It has been 
found native, in large masses, in Siberia, 
and in the internal par ts of South America, 
This metal however in its native state is 
scarce : most iron is found in the state of 
oxide, in ochres, bog ores, and other friable 
earthy substances, of a red, brown, yellow, 
or black colour. The hematites, or blood 
stones, are likewise ores with oxide of iron : 
these are either of a red colour, or blue, 
yellow, or brown. An iron ore is likewise 
found, of a blue colour, and powdery ap- 
pearance. This useful metal is so abundant, 
that whole mountains are composed of iron 
stone ; whereas other metals usually run in 
small veins. Besides these ores of iron, 
which are either nearly pure, or else mixed 
with earths, as in spars, jasper, boles, ba- 
saltes, See., iron is mineralized with sulphur, 
as in the pyrites; or with arsenic. The 
coally iron ores contain bitumen. The 
magnet, or loadstone, is an iron ore, the 
constitution of which has not yet been ac- 
curately examined. Iron is also found in 
combination with the sulphuric acid, either 
dissolved in water, or in the form of sul- 
phate. 
To analize the ores of iron in the humid 
way, they must be reduced tq a very subtle 
powder, and repeatedly boiled in muriatic 
acid. If the sulphureous ores should prove 
slo w of solution, a small quantity of nitric 
acid must be added to accelerate the ope- 
ration. The iron being thus extracted, the 
insoluble part of the matrix only will re- 
main. Prussiate of potash being added to 
the decanted solution, will precipitate the 
iron in the form of Prussian blue. This 
precipitate, when washed and dried, will be 
equal in weight to six times the quantity of 
metallic iron it contains ; and from this 
iron four parts in the hundred must be 
deducted, to allow for the iron which is 
contained in the prussiate of potash it- 
self. But as this alkali, and every other 
preparation containing the prussic acid, 
does not constantly afford the same quan- 
tity of iron, the most exact way, in the use 
of such preparations, consists in previously 
dissolving a known quantity of iron in 
sulphuric acid ; and precipitating the whole 
by the addition of the prussiate of potash. 
This result will afford a rule for the use of 
the same alkali in other solutions. For 
as the weight of the precipitate obtained 
in the trial experiment is to the quantity of 
iron which vvas dissolved and precipitated ; 
so is the weight of the precipitate obtained 
from any other solution to the quantity of 
iron sought. 
If the iron be united to any considerable 
proportion of zinc or manganese, the 
Prussian blue must be calcined to red- 
ness, and treated with strong nitric acid, 
which will take up the oxide of zinc. 
The manganese may then be dissolved by 
nitric acid with the addition of sugar; 
and the remaining iron being dissolved by 
muriatic acid, and precipitated by subcar- 
bonate of soda, will afford 225 grains of 
precipitate for every 100 grains of metallic 
iron. 
To examine the ores of iron in the dry 
way, the only requisite is fusion, in contact 
with charcoal. For this purpose eight parts 
of pulverized glass, one of calcined borax, 
and half a part of charcoal, are to be well 
mixed together. Two or three parts of 
this flux, being mixed with one of the 
pounded ore, and placed in a crucible, lined 
with a mixture of a little clay and pounded 
charcoal, witli a cover luted on, is to be 
urged with the strong heat of a smith’s forge 
for half an hour. The weight of the ore, 
in this experiment, should not exceed sixty 
grains. Other processes for determining 
the contents, or metallic product, of iron 
ores, are instituted by performing the same 
operations in the small, as are intended to 
be used in the large way. 
In the large iron-works, it is usual to 
roast or calcine the ores of iron, previously 
to their fusion ; as well for the purpose of 
expelling sulphureous or arsenical parts, as 
to render them more easily broken into frag- 
