+------+---------+---------+---------+------------+---------------+
|Years.| Produce |Consump- |Stock in | Highest | Good middling |
| |in India.| tion of |England | Price. | Violet. |
| | | World; | 31st | | |
| | |average, |December.| | |
| | |4 years. | | | |
+------+---------+---------+---------+------------+---------------+
| | | | | Per lb. | |
| |_Chests._|_Chests._|_Chests._| _s. d._ |_s. d. s. d._|
|1811 | 21,000 | 22,200 | 26,900 | 10 6 | 5 6 6 0 |
|1812 | 23,500 | 22,500 | 29,500 | 11 6 | 6 9 7 3 |
|1813 | 22,800 | 22,800 | 24,500 | 15 5 | 9 0 9 6 |
|1814 | 28,500 | 23,000 | 24,900 | 13 0 | 7 9 8 3 |
|1815 | 30,500 | 23,200 | 30,400 | 11 0 | 6 9 7 6 |
|1816 | 25,000 | 26,900 | 25,700 | 10 0 | 5 0 5 6 |
|1817 | 20,500 | 27,000 | 23,500 | 10 0 | 7 3 7 9 |
|1818 | 19,100 | 26,500 | 24,000 | 9 3 | 6 9 7 3 |
|1819 | 20,700 | 26,400 | 19,700 | 8 6 | 5 6 6 0 |
|1820 | 27,200 | 24,200 | 14,500 | 9 0 | 6 3 6 9 |
|1821 | 21,100 | 25,300 | 9,800 | 11 6 | 8 6 9 0 |
|1822 | 25,700 | 26,000 | 8,200 | 12 0 | 9 0 9 6 |
|1823 | 29,800 | 25,300 | 13,100 | 10 0 | 7 3 7 9 |
|1824 | 24,100 | 26,500 | 12,200 | 15 0 | 12 0 12 6 |
|1825 | 43,500 | 23,500 | 16,400 | 15 6 | 12 0 12 6 |
|1826 | 28,000 | 27,300 | 22,300 | 11 3 | 7 6 7 9 |
|1827 | 45,300 | 28,900 | 22,800 | 12 6 | 8 0 8 6 |
|1828 | 30,000 | 31,000 | 31,100 | 10 0 | 6 3 6 6 |
|1829 | 43,200 | 33,000 | 31,200 | 8 9 | 5 3 5 9 |
| | | | |Years. | |
|1830-1| 32,100 | 32,800 | 37,600 |1831 7 9 | 4 3 4 9 |
|1831-2| 32,500 | 34,500 | 35,700 |1832 6 3 | 4 3 4 6 |
|1832-3| 35,200 | 35,500 | 32,500 |1833 6 0 | 4 2 4 4 |
|1833-4| 27,100 | 34,600 | 35,800 |1834 8 0 | 6 3 6 6 |
|1834-5| 30,500 | 33,800 | 29,319 |1835 7 0 | 5 3 5 6 |
|1835-6| 32,600 | 34,700 | 21,449 |1836 6 3 | 4 9 5 0 |
|1836-7| -- | 32,600 | 26,219 |1837 8 9 | 6 9 7 0 |
+------+---------+---------+---------+------------+---------------+
EAST INDIA and SPANISH, &c. INDIGO.
+------+------------------------+---------+------------+
| | Importations. | | |
|Years.+-----------+------------+Exported.| Home |
| |East India.|Spanish, &c.| |Consumption.|
+------+-----------+------------+---------+------------+
| | _lbs._ | _lbs._ | _lbs._ | _lbs._ |
| 1785 | 154,291 | 1,539,218 | 584,885| |
| 1786 | 253,345 | 1,724,945 | 466,696| |
| 1787 | 364,046 | 1,514,784 | 502,800| |
| 1788 | 622,691 | 1,473,920 | 445,857| |
| 1789 | 371,469 | 1,594,618 | 673,630| |
| 1790 | 531,619 | 1,307,088 | 821,131| |
| 1791 | 465,198 | 1,141,589 | 870,185| |
| 1792 | 581,827 | 1,274,538 | 880,951| |
| 1793 | 890,766 | 1,066,817 | 929,707| |
| 1794 | 1,403,650 | 1,487,642 |1,623,908| |
| 1795 | 2,862,684 | 1,424,941 |1,387,171| |
| 1796 | 3,897,120 | 680,915 |1,883,320| |
| 1797 | 1,754,233 | 535,845 |3,105,610| |
| 1798 | 3,862,188 | 192,060 |1,718,624| |
| 1799 | 2,529,377 | 512,459 |2,585,755| |
| 1800 | 2,674,317 | 1,076,417 |2,586,833| |
| 1801 | 2,123,637 | 827,696 |2,281,812| |
| 1802 | 2,264,199 | 669,679 |1,961,346| |
| 1803 | 2,632,110 | 522,825 |1,130,194| |
| 1804 | 2,765,871 | 395,258 |1,523,095| |
| 1805 | 4,666,292 | 687,319 |1,845,035| |
| 1806 | 2,612,181 | 319,394 |2,904,614| |
| 1807 | 5,326,032 | 715,809 |2,006,463| |
| 1808 | 5,314,860 | 477,625 |1,568,351| |
| 1809 | 2,179,083 | 674,048 |3,179,861| |
| 1810 | 5,243,613 | 883,061 |2,485,679| |
| 1811 | 4,453,932 | 658,577 |1,566,056| |
| 1812 | 4,461,793 | 354,171 |1,853,916| |
| 1813 | Accounts destroyed by Fire at Custom House. |
| 1814 | 6,803,064 | 328,881 |5,501,851| 3,406,282 |
| 1815 | 5,543,852 | 79,253 |4,278,674| 2,774,091 |
| 1816 | 7,247,227 | 39,275 |4,214,454| 1,899,819 |
| 1817 | 5,001,280 | 134,313 |2,427,443| 2,377,659 |
| 1818 | 5,497,768 | 187,257 |2,963,462| 2,302,163 |
| 1819 | 3,689,052 | 129,682 |3,126,739| 2,033,601 |
| 1820 | 4,924,222 | 161,164 |4,378,857| 2,288,196 |
| 1821 | 3,943,592 | 119,517 |2,985,364| 1,959,509 |
| 1822 | 2,549,284 | 374,230 |2,378,948| 2,004,062 |
| 1823 | 6,557,296 | 664,408 |2,783,504| 2,322,221 |
| 1824 | 4,595,707 | 485,110 |2,795,740| 2,493,350 |
| 1825 | 6,233,335 | 560,296 |3,870,929| 2,381,233 |
| 1826 | 7,699,439 | 386,312 |4,365,163| 1,901,047 |
| 1827 | 5,404,811 | 662,936 |3,315,675| 2,399,365 |
| 1828 | 9,683,626 | 229,384 |4,588,658| 3,064,915 |
| 1829 | 5,978,527 | 769,757 |4,286,605| 2,113,830 |
| 1830 | 7,920,924 | 295,516 |4,686,784| 2,676,945 |
| 1831 | 7,004,510 | 290,089 |4,374,241| 2,490,134 |
| 1832 | 6,221,725 | 131,340 |5,346,725| 2,395,653 |
| 1833 | 6,304,016 | 331,016 |3,664,814| 2,323,300 |
| 1834 | 3,798,144 | 357,152 |3,928,226| 2,447,827 |
| 1835 | 3,986,233 | 183,480 |4,074,598| 2,606,772 |
| 1836 | 6,753,898 | 418,800 |3,691,951| 2,864,274 |
| 1837 | 5,872,601 | 673,270 |3,587,561| 2,240,451 |
+------+-----------+------------+---------+------------+
INDIAN RUBBER, is the vulgar name of caoutchouc in this country.
INK; (_Encre_, Fr.; _Tinte_, Germ.) is a coloured liquid for writing on
paper, parchment, linen, &c. with a pen.
_Black ink._--Nut-galls, sulphate of iron, and gum, are the only
substances truly useful in the preparation of ordinary ink; the other
things often added merely modify the shade, and considerably diminish
the cost to the manufacturer upon the great scale. Many of these inks
contain little gallic acid, or tannin, and are therefore of inferior
quality. To make 12 gallons of ink we may take,--
12 pounds of nutgalls,
5 pounds of green sulphate of iron,
5 pounds of gum senegal,
12 gallons of water.
The bruised nutgalls are to be put into a cylindrical copper, of a depth
equal to its diameter, and boiled, during three hours, with three
fourths of the above quantity of water, taking care to add fresh water
to replace what is lost by evaporation. The decoction is to be emptied
into a tub, allowed to settle, and the clear liquor being drawn off, the
lees are to be drained. Some recommend the addition of a little
bullock’s blood or white of egg, to remove a part of the tannin. But
this abstraction tends to lessen the product, and will seldom be
practised by the manufacturer intent upon a large return for his
capital. The gum is to be dissolved in a small quantity of hot water,
and the mucilage, thus formed, being filtered, is added to the clear
decoction. The sulphate of iron must likewise be separately dissolved,
and well mixed with the above. The colour darkens by degrees, in
consequence of the peroxidizement of the iron, on exposing the ink to
the action of the air. But ink affords a more durable writing when used
in the pale state, because its particles are then finer, and penetrate
the paper more intimately. When ink consists chiefly of tannate of
peroxide of iron, however black, it is merely superficial, and is easily
erased or effaced. Therefore whenever the liquid made by the above
prescription has acquired a moderately deep tint, it should be drawn off
clear into bottles, and well corked up. Some ink-makers allow it to
mould a little in the casks before bottling, and suppose that it will
thereby be not so liable to become mouldy in the bottles. A few bruised
cloves, or other aromatic perfume, added to ink, is said to prevent the
formation of mouldiness, which is produced by the ova of infusoria
animalcules. I prefer digesting the galls, to boiling them.
The operation may be abridged, by peroxidizing the copperas beforehand,
by moderate calcination in an open vessel; but, for the reasons above
assigned, ink made with such a sulphate of iron, however agreeable to
the ignorant, when made to shine with gum and sugar, under the name of
japan ink, is neither the most durable nor the most pleasant to write
with.
From the comparatively high price of gall-nuts, sumach, logwood, and
even oak bark, are too frequently substituted, to a considerable
degree, in the manufacture of ink.
The ink made by the prescription given above, is much more rich and
powerful than many of the inks commonly sold. To bring it to their
standard, a half more water may safely be added, or even 20 gallons of
tolerable ink may be made from that weight of materials, as I have
ascertained.
Sumach and logwood admit of only about one half of the copperas that
galls will take to bring out the maximum amount of black dye.
Chaptal gives a prescription in his _Chimie appliquée aux arts_, which,
like many other things in that book, are published with very little
knowledge and discrimination. He uses logwood and sulphate of copper, in
addition to the galls and sulphate of iron; a pernicious combination
productive of a spurious fugitive black, and a liquor corrosive of pens.
It is, in fact, a modification of the vile dye of the hatters.
Lewis, who made exact experiments on inks, assigned the proportion of 3
parts of galls to 1 of sulphate of iron, which, with average galls, will
answer very well; but good galls will admit of more copperas.
_Gold ink_ is made by grinding upon a porphyry slab, with a muller, gold
leaves along with white honey, till they be reduced to the finest
possible division. The paste is then collected upon the edge of a knife
or spatula, put into a large glass, and diffused through water. The gold
by gravity soon falls to the bottom, while the honey dissolves in the
water, which must be decanted off. The sediment is to be repeatedly
washed till entirely freed from the honey. The powder, when dried, is
very brilliant, and when to be used as an ink, may be mixed up with a
little gum water. After the writing becomes dry, it should be burnished
with a wolf’s tooth.
_Silver ink_ is prepared in the same manner.
_Indelible ink._--A very good ink, capable of resisting chlorine, oxalic
acid, and ablution with a hair pencil or sponge, may be made by mixing
some of the ink made by the preceding prescription, with a little
genuine China ink. It writes well. Many other formulæ have been given
for indelible inks, but they are all inferior in simplicity and
usefulness to the one now prescribed. Solution of nitrate of silver
thickened with gum, and written with upon linen or cotton cloth,
previously imbued with a solution of soda, and dried, is the ordinary
permanent ink of the shops. Before the cloths are washed, the writing
should be exposed to the sun-beam, or to bright daylight, which blackens
and fixes the oxide of silver. It is easily discharged by chlorine and
ammonia.
_Red ink._--This ink may be made by infusing, for 3 or 4 days in weak
vinegar, Brazil wood chipped into small pieces; the infusion may be then
boiled upon the wood for an hour, strained, and thickened slightly with
gum arabic and sugar. A little alum improves the colour. A decoction of
cochineal with a little water of ammonia, forms a more beautiful red
ink, but it is fugitive. An extemporaneous red ink of the same kind may
be made by dissolving carmine in weak water of ammonia, and adding a
little mucilage.
_Green ink._--According to Klaproth, a fine ink of this colour may be
prepared by boiling a mixture of two parts of verdigris in eight parts
of water, with one of cream of tartar, till the total bulk be reduced
one half. The solution must be then passed through a cloth, cooled, and
bottled for use.
_Yellow ink_ is made by dissolving 3 parts of alum in 100 of water,
adding 25 parts of Persian or Avignon berries bruised, boiling the
mixture for an hour, straining the liquor, and dissolving in it 4 parts
of gum arabic. A solution of gamboge in water forms a convenient yellow
ink.
By examining the different dye-stuffs, and considering the processes
used in dyeing with them, a variety of coloured inks may be made.
_China ink._--Proust says, that lamp-black purified by potash lye, when
mixed with a solution of glue, and dried, formed an ink which was
preferred by artists to that of China. M. Merimée, in his interesting
treatise, entitled, _De la peinture à l’huile_, says, that the Chinese
do not use glue in the fabrication of their ink, but that they add
vegetable juices, which render it more brilliant and more indelible upon
paper. When the best lamp-black is levigated with the purest gelatine or
solution of glue, it forms, no doubt, an ink of a good colour, but wants
the shining fracture, and is not so permanent on paper as good China
ink; and it stiffens in cold weather into a tremulous jelly. Glue may be
deprived of the gelatinizing property by boiling it for a long time, or
subjecting it to a high heat in a Papin’s digester; but as ammonia is
apt to be generated in this way, M. Merimée recommends starch gum made
by sulphuric acid (British gum) to be used in preference to glue. He
gives, however, the following directions for preparing this ink with
glue. Into a solution of glue he pours a concentrated solution of
gall-nuts, which occasions an elastic resinous-looking precipitate. He
washes this matter with hot water, and dissolves it in a spare solution
of clarified glue. He filters anew, and concentrates it to the proper
degree for being incorporated with the purified lamp-black. The
astringent principle in vegetables does not precipitate gelatine when
its acid is saturated, as is done by boiling the nutgalls with limewater
or magnesia. The first mode of making the ink is to be preferred. The
lamp-black is said to be made in China, by collecting the smoke of the
oil of sesame. A little camphor (about 2 per cent.) has been detected in
the ink of China, and is supposed to improve it. infusion of galls
renders the ink permanent on paper.
_Sympathetic ink._ The best is a solution of muriate of cobalt.
_Printer’s ink._ See this article.
By decomposing vanadate of ammonia with infusion of galls, a liquid is
obtained of a perfectly black hue, which flows freely from the pen, is
rendered blue by acids, is insoluble in dilute alkalis, and resists the
action of chlorine. Whenever the metal vanadium shall become more
abundant, as it probably may ere long, we shall possess the means of
making an ink, at a moderate price, much superior to the tannate and
gallate of iron.
To prepare the above vanadic salt cheaply, the cinder or hammerschlag
obtained from the iron made at Ekersholm, in Sweden, or other iron which
contains vanadium, being reduced to a fine powder, is to be mixed with
two thirds of its weight of nitre, and one third of effloresced soda.
The mixture is to be ignited in a crucible; cooled and lixiviated,
whereby solutions of the vanadates of potash and soda are obtained, not
pure, indeed, but sufficiently so for being decomposed, by means of sal
ammoniac, into a vanadate of ammonia. This being rendered nearly neutral
with any acid, constitutes an excellent indelible ink.
INULINE; (Eng. and Fr.) is a substance first extracted from the root of
the _Inula-Hellenium_, or Elecampane. It is white and pulverulent like
starch; and differs from this substance chiefly because its solution,
when it cools, lets fall the inuline unchanged in powder, whereas starch
remains dissolved in the cold, as a jelly or paste.
Inuline is obtained by boiling the root sliced in 3 or 4 times its
weight of water, and setting the strained decoction aside till it cools,
when the pulverulent inuline precipitates. It exists also in the roots
of colchicum, and pellitory.
IODINE; (_Iode_, Fr.; _Iod_, Germ.) is one of the archæal undecompounded
chemical bodies, which was discovered accidentally in 1812 by M.
Courtois, a manufacturer of saltpetre, in the mother-waters of that
salt. Its affinities for other substances are so powerful as to prevent
it from existing in an insulated state. It occurs combined with
potassium and sodium in many mineral waters, such as the brine spring of
Ashby-de-la-Zouche, and other strongly saline springs. This combination
exists sparingly in sea-water, abundantly in many species of _fucus_ or
sea-weed, and in the kelp made from them; in sponges; in several marine
_molluscæ_, such as the _doris_, the _venus_, oysters, &c.; in several
polyparies, and sea plants, as the _gorgonia_, the _zostera marina_,
&c.; particularly in the mother-waters of the salt works upon the
Mediterranean sea; and it has been found in combination with silver, in
some ores brought from the neighbourhood of Mexico.
Iodine is most economically procured from the mother-water of kelp, as
furnished by those manufacturers of soap in Scotland and elsewhere who
employ this crude alkaline matter. By pouring an excess of sulphuric
acid upon that liquid, and exposing the mixture to heat in a retort,
iodine rises in _violet_ vapours (whence its name), and condenses in the
receiver into black, brilliant, soft, scaly crystals, resembling
graphite or plumbago. An addition of the peroxide of manganese to the
above mixture, favours the production of iodine. Soubeiran has proposed,
as a means of extracting it in greater abundance from a given quantity
of the said mother-waters, to transform the iodide of potash or soda,
present, into an insoluble iodide of copper, by pouring into them
solution of sulphate of copper, which precipitates first of all one half
of the iodine. He then decants the supernatant liquor, and adds to it a
fresh quantity of the sulphate along with some iron filings. The latter
metal seizes the oxygen and sulphuric acid of the cupreous salt, sets
the copper free, which then seizes the other half of the iodine. To
separate this iodide from the remaining iron filings, he agitates the
whole with water, and decants the liquor. The filings immediately
subside, but the iodide of copper remains for some time in a state of
suspension. This compound, separated by a filter cloth, is to be mixed
with twice its weight of the black peroxide of manganese, and as much
sulphuric acid as will make the mixture into a paste; which mixture
being introduced into a retort, and distilled, the iodine comes over in
its characteristic violet vapours, which are condensed into the
glistening black substance in the receiver.
Iodine is always solid at atmospheric temperatures, though it slowly
flies off with a peculiar offensive penetrating odour somewhat like
chlorine. Its specific gravity is 4·946 at the temperature of 58° Fahr.
Its prime equivalent, according to Berzelius, is 63·283, one volume of
hydrogen being 1·000; but 126·566, if two volumes of hydrogen be
reckoned unity, as most British chemists estimate it, from the
composition of water. It possesses in a high degree electro-negative
properties, like oxygen and chlorine; and therefore makes its appearance
at the positive pole, when its compounds are placed in the voltaic
circuit. It stains the skin yellow; and if applied for some time to it,
is apt to produce painful ulcerations.
Iodine melts only at about 390° Fahr.; but with the vapour of water it
volatilizes at 212°. It has a great affinity for hydrogen, and
constitutes by that union hydriodic acid; a compound resembling in some
respects muriatic or hydrochloric acid. It also can be combined with
oxygen, and forms thereby iodic acid. Its compounds with carbon,
phosphorus, sulphur, chlorine, azote, and many metals have not been
applied to any manufacturing purpose, and therefore need not be
described here.
The chief application of iodine in the arts, is for the detection of
starch, which its watery solution, though containing only one part in
5000, does readily, by the production of a deep purple colour; this
vanishes by exposing the starch to the air for some time, or more
quickly by heating it.
As a medicine, iodine and its compounds, such as the iodides of
potassium and iron, are supposed to possess great powers in resolving
glandular swellings. The periodide of mercury is a brilliant red
pigment, but somewhat evanescent.
Chlorine, bromine, and iodine are frequently associated; and it has
hitherto been reckoned a difficult problem to separate them from one
another. The following plan is proposed by M. Lövig.
Heat the mixture of the dried chloride and bromide (or chloride and
iodide) while a current of chlorine is made to pass over it, till no
more bromine is carried off by the chlorine. Receive the gases in a
solution of potash; saturate this fluid mixture of the chloride of
potassium, and the chlorate and bromate of potash with nitric acid,
adding afterwards nitrate of silver. A mixture of bromate and chloride
of silver will precipitate. Dry the precipitate, calcine it, and
calculate the proportion of bromine from the volume of oxygen gas now
disengaged. It would be preferable to digest in a phial, the precipitate
while moist, along with water of baryta, which decomposes the bromate of
silver without acting upon the chloride. The excess of baryta being
thrown down by carbonic acid, and the liquid being evaporated, a bromate
of baryta is obtained, which may be washed with alcohol of 0·840. The
solution of bromate of baryta may also be neutralized by nitric acid,
and the bromic acid may be precipitated by nitrate of silver. The same
method is applicable to the separation of iodine from chlorine.
After throwing down the solution of the mixed salts by nitrate of
silver, Berzelius digests the washed precipitate in a closed bottle of
water of baryta; whence results bromate of baryta without any chloride
of barium. On evaporating the liquor we obtain crystallized bromate of
baryta, which may be freed from a small accidental quantity of chloride,
by washing with alcohol at 0·840. By calcination we then obtain bromide
of barium, which being distilled with sulphuric acid and peroxide of
manganese, affords bromine.
IRIDIUM, is a metal discovered by Descotils in 1803, as also by Tennant
in 1804; and is so called because its different solutions exhibit all
the colours of the rainbow. It occurs only in the ore of platinum, being
found there in two states; 1. united to that metal, and 2., as alloy of
osmium and iridium, in the form of small, insulated, hard grains.
Iridium is the most refractory of all the metals; and appears as a gray
metallic powder. It is not fused by the flame of the hydroxygen lamp.
IRON; (_Fer_, Fr.; _Eisen_, Germ.) is a metal of a bluish-gray colour,
and a dull fibrous fracture, but it is capable of acquiring a brilliant
surface by polishing. Its specific gravity is 7·78. It is the most
tenacious of metals, and the hardest of all those which are malleable
and ductile. It is singularly susceptible of the magnetic virtue, but in
its pure state soon loses it. When rubbed it has a slight smell, and it
imparts to the tongue a peculiar astringent taste, called chalybeate. In
a moist atmosphere, iron speedily oxidizes, and becomes covered with a
brown coating, called rust.
Every person knows the manifold uses of this truly precious metal; it is
capable of being cast in moulds of any form; of being drawn out into
wires of any desired strength or fineness; of being extended into plates
or sheets; of being bent in every direction; of being sharpened,
hardened, and softened at pleasure. Iron accommodates itself to all our
wants, our desires, and even our caprices; it is equally serviceable to
the arts, the sciences, to agriculture, and war; the same ore furnishes
the sword, the ploughshare, the scythe, the pruning hook, the needle,
the graver, the spring of a watch or of a carriage, the chisel, the
chain, the anchor, the compass, the cannon, and the bomb. It is a
medicine of much virtue, and the only metal friendly to the human frame.
The ores of iron are scattered over the crust of the globe with a
beneficent profusion, proportioned to the utility of the metal; they are
found under every latitude, and every zone; in every mineral formation,
and are disseminated in every soil. Considered in a purely mineralogical
point of view, without reference to their importance for reduction, they
may be reckoned to be 19 in number; namely, 1. native iron of three
kinds: pure, nickeliferous, and steely; 2. arsenical iron; 3. yellow
sulphuret of iron; 4. white sulphuret of iron; 5. magnetic sulphuret of
iron; 6. black oxide of iron, either the loadstone, or susceptible of
magnetism, and titaniferous; 7. compact _fer oligiste_, specular iron
ore, as of Elba, and scaly _fer oligiste_; 8. hematite, affording a red
powder; 9. hematite or hydrate of iron, affording a yellow powder, of
which there are several varieties; 10. pitchy iron ore; 11.
siliceo-calcareous iron, or yenite; 12. sparry carbonate of iron, and
the compact clay iron-stone of the coal formation; 13. phosphate of
iron; 14. sulphate of iron, native copperas; 15. chromate of iron; 16.
arseniate of iron; 17. muriate of iron; 18. oxalate of iron; 19.
titanate of iron.
Among all these different species, ten are worked by the miner, either
for the sake of the iron which they contain; for use in their native
state; or for extracting some principles from them advantageous to the
arts and manufactures; such are arsenical iron, sulphate of iron,
sulphuret of iron, and chromate of iron.
1. _Native iron_ A. Pure.--This species is very rare, and its existence
was long matter of dispute; though it has been undoubtedly found not
only in volcanic formations, but in veins properly so called. It is not
entirely like our malleable iron; but is whiter, more ductile, more
permanent or less oxidizable in the air, and somewhat less dense. Among
the best attested examples of pure native iron is that observed by M.
Schreber, in the mountain of Oulle near Grenoble. The metal was
entangled in a vein running through gneiss, and appeared in ramifying
stalactites, enveloped in fibrous brown-oxide of iron mixed with quartz
and clay.
B. The _native nickeliferous_ or _meteoric iron_ is very malleable,
often cellular, but sometimes compact, and in parallel plates, which
pass into rhomboids or octahedrons. It is naturally magnetic, and by its
nickel is distinguishable from terrestrial native iron. Macquart, in
describing the famous mass found at mount Kemir in Siberia, says that
the iron is perfectly flexible, and fit for making small instruments at
a moderate heat; but in too strong a fire, the metal becomes short,
brittle, and falls into grains under the hammer. Meteoric iron is
covered with a sort of varnish which preserves its surface from the
rusting action of the air; but this preservative property does not
extend to the interior. Chladni has given a list of masses of meteoric
iron, which have been known to fall at different times from the
atmosphere, and of many specimens which indicate their atmospheric
origin, by their aspect and composition. A portion of the mass of
meteoric iron found at Santa-Rosa near Santa-Fe-de-Bogota, was made into
a sword, and presented to Bolivar.
C. _Native steel-iron._--This substance has all the characters of
cast-steel; it occurs in a kind of small button ingots, with a finely
striated surface, and a fracture exceedingly fine grained. It is hardly
to be touched by the file, and will scarcely flatten under the hammer.
M. Mossier found this native steel at the village of Bouiche, near Nery,
department of the Allier, in a spot where there had existed a seam of
burning coal. A mass of 16 pounds and 6 ounces of native steel was
discovered in that place, besides a great many small globules.
2. _Arsenical iron_, _Arsenikkies_ or _Mispickel_, is a tin-white
mineral, which emits a garlic smell at the blowpipe, or even when sparks
are struck from it by steel, accompanied with a small train of white
smoke. It contains generally more or less sulphur and sometimes a little
silver, associated with metallic arsenic and iron.
3. _Yellow sulphuret of iron_, commonly called _Marcasite_, or Martial
pyrites. The bronze or brass-yellow colour enables us to recognize this
mineral. At the blowpipe it gives off its sulphur, and is converted into
a globule attractable by the blowpipe. It is a bisulphuret of iron
containing 32 of sulphur and 28 of metal.
Copper pyrites may be distinguished from it by its golden yellow colour,
which is frequently iridescent, and by its inferior hardness; for it
does not strike fire with steel, like the preceding persulphuret. There
is no vein, stratum, or mass of metallic ore which does not contain some
iron pyrites; and it is often the sole mineral that fills the veins in
quartz. It sometimes contains gold, and at other times silver.
4. _White sulphuret of iron._--This is distinguishable from the
preceding species only by its colour and form of crystallization, and
was hence till lately confounded with it by mineralogists. Its surface
is often radiated.
5. _Magnetic sulphuret of iron_, the _Magnetkies_ of the Germans.--This
ore is attractable by the magnet like common iron. Its colour is
reddish-yellow, passing into brown; its fracture is rough. It consists
of 16 of sulphur and 28 of iron.
6. _Black oxide of iron_, _magnet ore_, or _native loadstone_.--One
variety of this species has two poles in each specimen, which manifest a
repulsive action against the corresponding poles of a magnetic needle.
All the varieties furnish a black powder. Its external colour is a gray
approaching to that of metallic iron, but somewhat duller; with
occasional iridescence of surface. Neither nitric acid nor the blowpipe
has any action upon it. Its specific gravity varies from 4·24 to 5·4;
and its constituents are 71·86 peroxide, and 28·14 protoxide, according
to Berzelius; or in 100 parts, 71·74 of metallic iron, and 28·26 of
oxygen. Assuming the prime equivalent of iron to be 28, with the British
chemists, then an ore consisting, like the above, of two prime
proportions of peroxide, and one of protoxide, would be represented by
the number 116 = 80 + 36; and would consist in 100 parts, of iron 72·4,
oxygen 27·6.
Magnetic iron-ore belongs to primitive rock formations, and occurs
abundantly in Sweden, Dalecarlia, Norway, Siberia, China, Siam, and the
Philippine Isles; but it is rare in England and France. It is worked
extensively in Sweden, and furnishes an excellent iron.
The titaniferous oxide of iron, or iron sand, is also attractable by the
magnet. Its colour is a deep black, with some metallic lustre; it is
perfectly opaque: its fracture is conchoidal; it is hard and difficult
to grind under the pestle into a dull black powder, which stains the
fingers when it is very fine; it melts at a high heat into a black
enamel without lustre. All volcanic rocks contain a greater or less
quantity of titanic iron-ore, disseminated through them, which may be
recognised by its brilliant metallic lustre, and its perfect conchoidal
fracture.
7. _Fer oligiste, iron-glance, specular iron and red iron-ore._--This
ore has the colour of polished steel; and the light transmitted through
the thin edges of its crystals appears of a beautiful red. Its powder is
always of a well marked brown-red hue, passing into cherry-red, which
distinguishes it from the black-oxide ore. Its fracture is rough, or
vitreous in certain varieties; it breaks easily; but it is hard enough
to scratch glass. It usually contains from 60 to 70 of metallic iron in
100 parts; the equivalent proportion of oxygen in the pure red oxide of
iron being 30 parts combined with 70 of metal. It is a mistake to
suppose any specular iron ore capable of yielding 85 per cent. of iron,
for 100 parts of even protoxide of iron contain only 77·77 parts of
metal.
The compact variety comprises the crystals of the island of Elba, and of
Framont in the Vosges, which have a rough-grained fracture. It exists in
very great masses, constituting even entire mountains; in the cavities
and fissures of these masses, the beautiful crystals so much prized by
collectors of minerals, occur.
[Illustration: 581]
The island of Elba is equally celebrated for its inexhaustible abundance
of rich specular iron-ore, and for the immemorial antiquity of its
mining operations. _Fig._ 581. is a vertical section passing through the
three workings, called Pietamonte (D), Sanguinaccio (E), Antenna (F),
through an antient excavation _a_, through the coast _o_, and the mole
_p_, ending at the canal of Piombino. The total height of the
metalliferous mountain above the level of the sea, is no more than 180
metres, or 600 feet.
The rock which constitutes the body of this little mountain _d l_, is
called _bianchetta_ by the workmen. It is a white slaty talc, slightly
ochreous, or yellowish, consisting chiefly of silica and alumina, with
some magnesia.
The ore of Antenna (F) is a very hard compact _fer oligiste_, of a
brilliant metallic aspect. The workable bed has a height of 66 feet, and
consists of metalliferous blocks mixed confusedly with sterile masses of
the rock; the whole covered with a rocky detritus, under a brownish
mould. From its metallic appearance and toughness, this bed is called
_vena ferrata_, the iron vein. In Pietamonte the workable bed is
composed entirely of micaceous specular iron ore (_fer oligiste_), with
its fissures filled with yellow ochre. This bed rests upon the rock
called _bianchetta_; the brilliant aspect of ore in this place has
gained for it the name of _vena lucciola_.
The metalliferous hill _d l_, extends to the north-east, about a mile
beyond the workings D E F. The ore contains about 65 per cent. of iron,
and is smelted in Catalan forges.
The following description of the figure will make the structure of this
extraordinary mine well understood. _a_, is a great excavation, the
result of antient workings.
1, 1; 2, 2; 3, 3, 4, 4, 5, 6, and 7, are roads for carrying off the
rubbish, in correspondence with the several working levels.
_b_, _b_, _b_, masses of old rubbish (_deblais_).
_c_, _c_, ditto, from the present workings D, E, F.
_d_, the rocky mass called bianchetta, against which the ore extracted
from _a_, abuts.
_e_, the surface of a bed of ore, near the streamlet _g_.
_f_, _f_, indication of beds of iron pyrites and _fer oligiste_.
_g_, a small rivulet preceding from the infiltration of rains, and which
is impregnated with acidulous sulphate of iron.
_h_, _h_, ravine which separates the metalliferous hill _d l_, from the
barren hill _i_.
_k_, masses of slags from ancient smelting operations; such are very
common in this island. None of any consequence now exists; nearly the
whole of the ore being exported to Tuscany, the Romagna, the Genoese
territories, Piedmont, Naples, and Corsica.
_l_, a considerable body of rubbish from ancient workings, towards the
summit of the metalliferous hill _d_, _l_.
_m_, _m_, part of this hill covered with rubbish, the result of old
workings.
_n_, the site called _Vigneria_.
_o_, houses upon the shore called _Marine de Rio_, where the workpeople
live, and the mineral is kept in store.
_p_, wooden pier (_mole_) whence the ore is shipped; terminated by a
small tower _q_.
Compact _fer oligiste_ occurs also in the Vosges, in Corsica, at
Altenberg and Freyburg in Saxony, Presnitz in Bohemia, Norberg and
Bisberg in Sweden, &c.
The varieties called specular _fer oligiste_, and scaly _fer oligiste_,
or iron-glance, do not differ essentially from the compact. None of them
affects the magnetic needle, and their powder is a red of greater or
less vivacity.
8. _Red oxide of iron._--The varieties included under this species
afford a red powder, do not affect the magnetic needle, and are
destitute of metallic lustre. At the blowpipe they all become black, or
deep brown; and then they act on the needle. The crystallized variety
consists of 70 iron and 30 oxygen in 100 parts. The concretionary kind,
or _hematite_, has a brown-red colour; is solid, compact, and sometimes
very hard; its surface may be filed and polished so as to acquire a
lustre almost metallic; its internal structure is fibrous, and it
exhibits sometimes a resemblance to splinters of wood. Its outer surface
is constantly concretionary, mammelated, and presents occasionally
sections of a sphere, or cylinders attached to each other. This is the
blood-stone of the burnisher of metals. It is a very common mineral. The
ochry variety or red-iron-ochre is distinguished from the solid hematite
by the brightness of its colour. It is used as a pigment.
9. _Brown oxide of iron, brown iron-stone._--This affords always a
yellow powder, without any shade of red, which passes sometimes into the
bistre brown, or velvet black. At the blowpipe this oxide becomes brown,
and very attractable by the magnet; but after calcination and cooling,
the ore yields a red powder, which stains paper nearly as red as
hematite does; and which is much employed in polishing metals. All the
yellow or brown oxides contain a large proportion of water, in chemical
combination; and hence this species has been called hydrate of iron.
There are several varieties which assume globular, reniform,
stalactitic, and fruticose shapes. As impure varieties of the species we
must consider some of the clay-iron-ores, such as the granular, the
common, the pisiform, and the reniform clay-iron-ore. According to
D’Aubuisson, the present species consists of peroxide of iron, from 82
to 84 _per cent._; water, 14 to 11; oxide of manganese, 2; silica, 1 to
2. It is therefore a hydrated peroxide of iron; and ought by theory, to
consist, in its absolute state, of 81·63 peroxide, and 18·37 water. It
occurs both in beds and veins. The _œtites_ or eagle-stones form a
particular variety of this ore. On breaking the balls so named, they are
observed to be composed of concentric coats, the outside ones being very
hard, but the interior becoming progressively softer towards the centre,
which is usually earthy and of a bright yellow colour; sometimes however
the centre is quite empty, or contains only a few drops of water. Œtites
occur in abundance, often even in continuous beds in secondary
mountains, and in certain argillaceous strata. These stones are still
considered by the French shepherds as amulets or talismans, and may be
found in the small bags which they suspend to the necks of their
favourite rams; and they are in such general use that a large quantity
is annually imported into France from the frontiers of Germany, for this
superstitious purpose. When smelted, they yield a good iron.
The variety called _granular brown oxide_, _or bone ore_, is merely a
modification of the preceding. It occurs in grains nearly round, varying
in size from a millet seed to a pea, each being composed of concentric
coats, hard outside and soft within. They are generally agglutinated by
a calcareous or argillaceous paste; but are occasionally quite loose.
This ore occurs in calcareous formations, and is sometimes accompanied
with shells, such as _terebratulæ_. The brittle quality of the iron
afforded by it, has been ascribed to the phosphorus derived from the
large quantity of organic bodies, with which the ore is frequently
mixed. The bog-iron-ore, and swamp iron ore belong to this species.
10. _Pitchy hydrate of iron._--This is a rare mineral of a resinous
aspect, found in a vein in the mine of Braunsdorf, two leagues from
Freyberg, and seems to consist of red oxide of iron and water.
11. _Yenite_, is a mineral species rather rare, composed of red oxide of
iron, silica, and lime.
12. _Carbonate of iron, sparry iron, or brown-spar._--This important
species has been divided into two varieties; spathose iron, and the
compact carbonate. The first has a sparry and lamellar fracture; with a
colour varying from yellowish-gray to isabella yellow, or even to
brownish-red. It turns brown without melting at the blowpipe, and
becomes attractable by the magnet after being slightly roasted in the
flame of a candle. Even by a short exposure to the air, after its
extraction from the mine, it also assumes the same brown tint, but
without acquiring the magnetic quality. It affords but a slight
effervescence with nitric acid, changing merely to a red-brown colour.
Its specific gravity varies from 3·00 to 3·67. Its primitive form is
like that of carbonate of lime, an obtuse rhomboid. Without changing
this form, its crystals are susceptible of containing variable
quantities of carbonate of lime, till it passes wholly into this
mineral. Manganese and magnesia enter also occasionally into its
composition.
Sparry carbonate of iron belongs to primitive formations; forming
powerful veins in mountains of gneiss, and is associated in these veins
with quartz, copper pyrites, gray copper, fibrous brown oxide of iron,
and a variety of ramose carbonate of lime, vulgarly called _flos ferri_.
Thus it is found at Allevard and Vizille, near Grenoble, at Saint-George
d’Huretière, in the Alps of Savoy; at Baigorry, in the Lower Pyrenees;
at Eisenerz, in Styria; at Hüttenberg, in Carinthia; at Schwartz, in the
Tyrol; in Saxony, Hungary, other places in Germany, as also in Spain,
Sweden, Norway, and Siberia. It also occurs along with galena, and other
ores of lead, in the mines of Lead-Hills, and Wanlockhead, in Scotland;
and in the mines of Cumberland, Northumberland, and Derbyshire; likewise
with tin-ore, at Wheal Maudlin, Saint-Just, and other places in
Cornwall.
This ore viewed as a metallurgic object, is one of the most interesting
and valuable that is known; it affords natural steel with the greatest
facility, and accommodates itself best to the Catalan smelting forge. It
was owing in a great measure to the peculiar quality of the iron which
it produces, that the excellence long remarked in the cutlery of the
Tyrol, Styria, and Carinthia was due. It was called by the older
mineralogists _steel ore_.
The carbonate of iron of the coal formation, is the principal ore from
which iron is smelted in England and Scotland, and it yields usually
from 30 to 33 per cent. of cast metal. We are indebted to Dr. Colquhoun
for several elaborate analyses of the sparry-irons of the Glasgow coal
field; ores which afford the best qualities of iron made in that
district. The richest specimen out of the nine which he tried, came from
the neighbourhood of Airdrie; it had a specific gravity of 3·0533, and
afforded in 100 parts; carbonic acid, 35·17; protoxide of iron, 53·03;
lime, 3·33; magnesia, 1·77; silica, 1·4; alumina, 0·63; peroxide of
iron, 0·23; carbonaceous or bituminous matter, 3·03; moisture and loss,
1·41. Its contents in metallic iron are 41·25.
The _compact carbonate of iron_ has no relation externally with the
sparry variety. It comprehends most of the clay-iron-stones, and
particularly that which occurs in flattened spheroidal masses of various
size, among the coal measures. The colour of this ore is often a
yellowish-brown, reddish-gray, or a dirty brick-red. Its fracture is
close grained; it is easily scratched, and gives a yellowish-brown
powder. It adheres to the tongue, has an odour slightly argillaceous
when breathed upon, makes no effervescence with any acid, blackens at
the blowpipe without melting, and becomes attractable by the magnet with
the slightest calcination.
This ore affords from 30 to 40 per cent. of iron of excellent quality;
and it is the object of most extensive workings in Great Britain. It
occurs in the slaty clay which serves as a roof or floor to the strata
of coal; and also in continuous beds, from 2 to 18 inches thick, among
the coal measures, as in Staffordshire, Shropshire, and Wales. It is
remarkable, that the coal-basin of Newcastle contains little clay
iron-stone, while the coal-basin of Dudley is replete with it.
13. _Phosphate of iron._--A dull blue colour is the most remarkable
external character of this species, which occurs in small masses
composed of aggregated plates, sometimes in an excessively fine powder,
or giving other bodies a blue tinge. It assumes at the blowpipe a rusty
hue, and is then reduced to a button of a metallic aspect. It dissolves
completely in dilute nitric acid, as well as in ammonia, but it does not
communicate its colour to them, and oil turns it black; characters which
distinguish it readily from blue carbonate of copper, whose colour is
not altered by ammonia. It is of no use as a smelting ore.
14. _Sulphate of iron, native green vitriol._--This is formed by the
oxygenation of sulphuret of iron, and is unimportant in a metallurgic
point of view.
15. _Chromate of iron._--For the treatment and use of this ore, see
CHROME.