Metals. MINE R 
curved with diftimft fine-grained concretions. When 
heated it reddens, but before the blowpipe blackens, and 
gives an olive-green tinge to borax. 
This fpecies is met with at Ulverftone, and feveral 
other places on the borders of Lancalhire. It affords very- 
good iron; and, as the proportion of earthy matter is 
linall, it requires very little limeftone for its reduction. 
Where the proportion of earthy matter in a metallic ore 
is large, and of an argillaceous nature, as is moft com¬ 
monly the cafe, limeftone is neceflary in the reduftion of 
it, in order to vitrify the earthy particles ; lime very eafily 
afting upon other earths fo as to convert them into glafs: 
and in the redufilion of an ore this glafs floats on the 
furface of the reduced metal, and is called a (lag. Its 
colour is ufually a brown or bluifh green, in confequence 
of the prefence of oxyd of iron ; which has the property 
of communicating a green colour to glafs. Red iron-ore 
may be diftinguifhed from compadl i'ulphuret of quick- 
filver, or cinnabar, in not being volatilized by heat; alfo 
in becoming magnetic by the application of the blowpipe. 
22. Ferrum haematites, or hematite: not magnetic; 
fibrous, liardifh, opake, with a red or yellow ftreak. There 
are four varieties ; black, brown, red, and yellow. They 
are found in various parts of England and Scotland, 
particularly in Lancafhire; in Ruffia, Siberia, and other 
parts of the continent; maflive, diffeminated, nodular, 
botryoidal, tabular, cellular; tubular, or ftaladfitical; hard, 
compadt, fibrous, or radiated, with the fragments ufually 
fplintery or wedge-fhaped; the fibres are ftellate, or fome- 
times in diftindt columns. The furface often variegated, 
and lometimes marked with fhrublike ramifications. Spe¬ 
cific gravity, from 3-423 to 5. 
The word hematite is derived apparently from thofe 
varieties, which, in confequence of their colour and tu¬ 
bercular form, referable a mafs of coagulated drops of 
blood: many of thefe very readily Haim with a red colour 
whatever they come into contadl with; and this is an 
additional reafon for the name. 
It was mentioned under the fpecies called F. fpecularis, 
that the cryftallized variety, met with near Eriftol, often 
accompanied hematitic iron-ore other varieties of fpe- 
cular iron-ore alfo very frequently accompany hematite; 
and, although the two fubftances, when pofleffmg their 
appropriate characters raoft perfedtly, are exceedingly dif¬ 
ferent ; yet they infenfibly graduate into each other. 
Thus fome of the Cumberland fpecimens of hematite are 
of fo compact a texture externally, that their furface has 
a fmoothnefs and fplendour fcarcely furpaffed by the Elba 
iron; and fometimes indeed they almoft appear to be 
portions of fimilar cryftals, fince they have diftinftly cryf- 
talline furfaces. On the other hand, in the fpecimens 
from Briftol above mentioned, the extreme parts have the 
perfeft appearance, one of hematite, the other of fpecular 
iron; and the tranfition from one ftate to the other ad¬ 
vances fo gradually as to be imperceptible to the eye. 
This natural connexion between the two fubftances feems 
eafily explicable from the fimilarity in their compofition, 
their nearly equal degree of fpecific gravity, and the red 
fhade of colour conftantly oblervable in pulverized fpe¬ 
cular iron-ore. 
Pebbles of native oxyd of iron, in an intermediate ftate 
between fpecular and hematitic ore, occur in fome in- 
ftances; and, on account of their hardnefs and fmooth¬ 
nefs, are ufed as burniftiing-ftones in the enamelling of 
gold, &c. Hematite itfelf, when fufficiently compadt and 
hard, is ufed for the fame purpofe. Fibrous hematite is 
fometimes difpofed to feparate into maffes refembling 
fplintery fragments of wood. In fome inftances the fibres 
converge in a curved direction. 
23. Ferrum compadum, or compact red iron-ore: not 
magnetic; compaft, opake, with a red or yellow ftreak. 
Found in Lancaftiire, Siberia, Saxony, Bohemia, See. maf- 
five, diffeminated, or varioufly imitative, fometimes form¬ 
ing beds or veins. Colour between brownifh-red and fteel- 
grey. Fra.Cture even or uneven, fometimes imperfedtly- 
Vol. XV. No. 1060. 
A L O G Y. Metals. 49? 
flaty or conchoidal. It ftains the fingers, blackens before 
the blowpipe, and gives a yellowiili-green tinge to borax. 
Specific gravity, 3-^. 
24. Ferrum fpatofum, fparry iron ore, or pearl-fpar: 
not magnetic; lamellar, effervefeing with acids, crack¬ 
ling and blackening before the blowpipe, breaking into 
rhomboidal fragments. Found in various parts of Great 
Britain and Europe, fometimes maftive, or diffeminated, 
or in fmall cryftals. Colour, when freih, white; but gra¬ 
dually tarnifliing to red, brown, yellow, bluifh, or varie¬ 
gated : ftreak grey or whitifh; fragments rhomboidal, 
with often a perlaceous or fatty luftre : it is foft, and can 
eafily be l'craped with a knife ; foluble with fome effervef- 
cence in acids, and decrepitates and becomes blackifli and 
magnetic before the blowpipe. Specific gravity, 3-6: 
contains iron 38, carbonat of lime 38, manganele 24. The 
iron obtained from this ore is in general of a very good 
quality, and eafily converted into lfeel : fometimes in¬ 
deed a part of the reduced metal is in the ftate of fteel 
upon its firft reduftion : hence this ore is fometimes called 
Jieel-ore. It is rarely met with in England. In the cen¬ 
tral parts of Europe it occurs in great abundance, and 
has been fmelted for many centuries. 
25. Ferrum filiceum, flinty iron, or finople: not mag¬ 
netic, ftriking fire with fteel. Found in the mines of 
Hungary and the Hartz foreft; conlifts of oxyd of iron, 
hornftone, quartz, and jafper, and fometimes a fmall por¬ 
tion of gold. 
26. Ferrum argillaceum, or argillaceous iron-ore : foft, 
opake, without luftre, dry. Found in various parts of 
Great Britain, and in Italy, Saxony, Germany, Bohemia, 
&c. in detached lumps or forming ftrata, fiftular, cellular, 
or varioufly imitative : colour reddifh or yellowifh grey, 
or various fhades of brown or black, with the furface of¬ 
ten uneven and bunchy: adheres to the tongue, and has 
a compaft, even or uneven, flaty or fplintery, frafture : it 
generally gives a reddilh-yellow ftreak, and lias an earthy 
linell when breathed on. Specific gravity, from 2-673 to 
3-471 : it iscompofed of oxyd of iron, alumine, lime, and 
filex, in various proportions. It affords from thirty to 
forty parts in a hundred of metallic iron ; but moft com¬ 
monly not much more than thirty. The iron however 
obtained from it is of a remarkable good quality. 
This is the ore which is worked fo extenfively in South 
Wales, in Shropfhire, and at Carron in Scotland. Its 
value is increafed by the coal and limeftone that ufually 
accompany it •. the limeftone being neceflary for the pur¬ 
pofe of vitrifying the argillaceous part; the coal, for the 
purpofe of reducing the oxyd of the iron. The firft pro- 
cefs reduces the metal to that ftate in which it is called 
crude, or cajl, or pig, iron ; the firft of which terms ex- 
preffes its imperfedtly-metallic ftate ; the fecond, that in 
a ftate of fufion it has been received into appropriate 
moulds; and the third, by a whimfical companion, the 
forms of thofe moulds ; that is, the melted iron being re¬ 
ceived into a broad longitudinal cavity, from which nu¬ 
merous fmaller cavities branch out at right angles, the 
whole prefents the appearance as it were of an animal 
fuckling a number of its young lying on each fide of it. 
The iron in this crude ftate being imperfeftly reduced, 
and having alfo imbibed a portion of the coaly matter 
employed in its reduftion, is too brittle and too hard for 
common purpofes. In the fubfequent procefs it is thrown 
into an horizontal furnace, and kept conftantly in con- 
taft with the fuel by which the furnace is l'upported; 
and, as the heat is fu.ficient to foften without melting it, 
it is kneaded conftantly by means of long rakes worked 
by men from the mouth of the furnace, till by degrees 
the oxygen contained in it is cn.: rely feparated; and the 
iron in that refpeft is reduced to a completely metallic 
ftate. The increafing toughnefs of the kneaded mafs af¬ 
fords the means of eftimating the progrefs of the opera¬ 
tion. But, as iron at a high temperature very readily 
imbibes charcoal, oh which property indeed depends the 
fabrication of fteel, the kneaded mafs of iron is not yet 
6 L of 
