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A 519958
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ARTES
18117
SCIENTIA
VERITAS
LIBRARY
OF THE
UNIVERSITY OF MICHIGAN
SPLURIBUS UMUM
TUEBOR
SI QUÆRIS PENINSULAM-AMŒNAM
CIRCUMSPICE
THE GIFT OF
C. B. Davis
THE
PLAYBOOK
PLAYBOOK OF METALS:
INCLUDING
PERSONAL NARRATIVES OF VISITS TO COAL, LEAD,
COPPER, AND TIN MINES;
WITH
A Large Number of Interesting Experiments
RELATING TO ALCHEMY AND THE CHEMISTRY OF THE FIFTY
METALLIC ELEMENTS.
BY
JOHN HENRY PEPPER,
AUTHOR OF "THE PLAYBOOK OF SCIENCE.'
With Three Hundred Illustrations.
A NEW EDITION.
LONDON:
GEORGE ROUTLEDGE AND SONS,
THE BROADWAY, LUDGATE.
NEW YORK: 416, BROOME STREET.
1869.

UNI
MICH
OF
MALLET'S MORTAR.
EEVANS.Sc
TO
WALTER HUGHES, ESQ.
SOUTHWOOD, HIGHGATE.
MY DEAR SIR,
As a slight token of my grateful esteem, permit
me to dedicate these pages on elementary science to
you, and with sentiments of sincere regard and respect,
to subscribe myself
Your Faithful and Obliged Friend,
JOHN HENRY PEPPER.
پانچ
INTRODUCTION
COAL AND COAL MINES
CONTENTS.
CHAPTER I.
CHAPTER II.
THE ART OF ALCHEMY THE PREFACE TO THE SCIENCES OF CHE-
MISTRY AND METALLURGY
CHAPTER III.
PAGE
1
3
116
THE METALS AND THEIR COMBINATIONS
. 152
CHAPTER IV.
GOLD
. 168
CHAPTER V.
SILVER
209
CHAPTER VI.
LEAD
. 233
CHAPTER VII.
COPPER
. 259
vi
CONTENTS.
CHAPTER VIII.
PAGE
TIN, ANCIENTLY CALLED JUPITER
. 291
CHAPTER IX.
MERCURY
. 318
CHAPTER X.
IRON
•
• 338
ALUMINIUM
CHAPTER XI.
CHAPTER XII.
ANTIMONY
·
•
. 395
. 416
CHAPTER XIII.
ARSENIC
424
CHAPTER XIV.
BARIUM
434
BISMUTII
•
CADMIUM.
CALCIUM
•
CERIUM
CHAPTER XV.
• 438
CHAPTER XVI.
411
CHAPTER XVII.
442
CHAPTER XVIII.
447
CHROMIUM
COBALT
CONTENTS.
CHAPTER XIX.
vii
PAGE
448
CHAPTER XX.
CHAPTER XXI.
DONARIUM, DIDYMIUM, ERBIUM, GLUCINUM, ILMENIUM, IRIDIUM,
LANTHANIUM, AND LITHIUM
CHAPTER XXII.
450
454
MAGNESIUM .
457
CHAPTER XXIII.
MANGANESE
. 460
CHAPTER XXIV.
MOLYBDENUM
464
CHAPTER XXV.
NICKEL
466
CHAPTER XXVI.
NIOBIUM, NORIUM, OSMIUM .
471
CHAPTER XXVII.
POTASSIUM
. 472
CHAPTER XXVIII.
PLATINUM
476
CHAPTER XXIX.
PALLADIUM, PELOPIUM
. 479
viii
CONTENTS.
PAGR
CHAPTER XXX.
RHODIUM, RUTHENIUM
482
CHAPTER XXXI.
SODIUM
483
CHAPTER XXXII.
STRONTIUM
486
CHAPTER XXXIII.
TANTALUM, TELLURIUM, TERBIUM, THORIUM, TITANIUM
488
CHAPTER XXXIV.
TUNGSTEN
490
CHAPTER XXXV.
URANIUM, VANADIUM, YTTRIUM
492
CHAPTER XXXVI.
ZINC
494
CHAPTER XXXVIL
ZIRCONIUM
. 503
CHAPTER XXXVIII.
GENERAL REMARKS
504
INTRODUCTION.
THE very flattering reception accorded to the "Playbook of Science"
has encouraged the author to endeavour to complete the popular
sketches not only of the great and imponderable powers of Nature
called Gravitation, Cohesion, Chemical Affinity, Heat, Light, Elec-
tricity, and Magnetism, but likewise to grapple with that very wide
field of inquiry comprehended in the subject of "Mines, Minerals,
and Metals." This theme involves the consideration of the fifty
metallic elements, which were wholly omitted in the former work;
the thirteen non-metallic elements-viz., Oxygen, Hydrogen, Nitro-
gen, Chlorine, Iodine, Bromine, Fluorine, Carbon, Boron, Silicon,
Selenium, Sulphur, and Phosphorus-being alone treated of in that
portion of the work devoted to the subject of Chemical Affinity; and
as the author has had the pleasure of visiting several Coal, Copper,
Lead, and Tin Mines, the personal narratives of those visits may be
of service to the youthful reader, who may be stimulated to go over
the same ground, and thus become practically acquainted, by personal
observation, with facts that are not likely to be easily forgotten after-
wards. A tour through the mining districts certainly impresses the mind
with the vast commercial results that can be obtained by persevering
industry and determination, coupled with scientific knowledge, and an
inspection of the engineering details shows what apparently insur-
mountable difficulties have been overcome. Such an example as the
great Dukinfield Coal Mine, in Cheshire, which is more than two
thousand feet deep, and occupied the proprietor twelve years in boring
and digging it, at a cost of 100,000l., is only one amongst other and
similar brilliant industrial triumphs won at the almost inaccessible
depths of the rock-formed crust of the earth; whilst the fact of the
B
2
INTRODUCTION.
value of the raw mineral products of Great Britain and Ireland being
estimated at about thirty millions sterling per annum, offers a further
inducement to the youthful reader to inquire how this mineral portion
of the dust of the earth is transmuted into such heaps of the precious
metal gold. Even if we disregard the strictly scientific portion of the
subject of the metals, the contemplation of the numerous useful purposes
to which they are applied is exceedingly amusing and instructive; thus
our houses contain all kinds of iron ware, stoves, grates, fire-irons,
locks, tin-plate ware, brass furniture, lead pipes, coppers, bells, wires,
lamps, Britannia metal, silver plate, electro-plated articles, jewellery,
pins, needles, cutlery, gold, silver, and copper coins, and silvered looking-
glasses.
The same metallic articles are all more or less contained in the huge
floating arks propelled by steam power, with the addition of great chain
cables, anchors, copper sheathing, compasses; or, when used for warlike
purposes, guns, swords, pistols, cannon, rifles, shot, shell, and bullets.
Again, in the more peaceful arts, there are the plough, husbandry im-
plements, machines, horse-shoes, tools, nails, screws, wire-work, type,
telescopes, microscopes, and other instruments, clocks, watches, trinkets.
In the fine arts, coinage, copper and steel engraved plates, zinc plates,
bronze and other metallic statues. And, to conclude a list which seems
endless, all the most stupendous forms of machinery, the steam-engines,
railways, suspension bridges, tubular bridges, and last, but not least, the
steam-horse, the locomotive, composed of 5416 pieces all fixed together,
and working as delicately as the finest bit of clockwork. These appli-
cations represent the mechanical value of the metals, but do not include
the almost equally important chemical metallic compounds indispensable
in the noble science of Medicine, in Chemistry, and in the useful arts of
dyeing, calico-printing, the colouring of glass, china, pottery, and the
thousand other requirements of this civilized but luxurious age.
The author desires here to express his obligations to Professor Ten-
nant, Mr. Evan Hopkins, and Professor Ansted, for much valuable
information, and recommends his readers to consult the more advanced
works on Geology, Mineralogy, Metallurgy, and Chemistry of Lyell,
Richardson, Phillips, Nicol, Scoffern, Clay, Oxland, Ure, Abel, Bloxam,
and Muspratt.

Fig. 1. Wellingtonia Gigantea in the Crystal Palace.
CHAPTER I.
COAL AND COAL MINES.
THE chief intention of this second "Playbook of Science" is to intro-
duce the important class of elements called the metals to our youthful
readers, and as nearly the whole of them, in their natural and mineral
state, are, as it were, invisible, by reason of their combination with other
B 2
4
COAL AND COAL MINES.
elements, which mask and conceal their metallic properties, it behoves
us to inquire what are the usual means resorted to for the purpose of
releasing the metals from their union with oxygen or sulphur, or other
common elements, and restoring to them with their liberty the important
qualities of brilliancy, malleability, ductility, and tenacity. The answer
to the previous query might be made at considerable length, if the
processes of the solution of the minerals by acids, as performed in
our laboratories, were fully described. We shall not, however, anticipate
these chemical details, which are better explained with each metal, but
will confine ourselves at present to that potent talisman "Coal," at
whose bidding, and whilst in a state of combustion, the minerals are
decomposed and liquefied, and their gritty, brittle, stony qualities
changed to those of tractility and extensibility. Coal is the commer-
cial substance specially required to obtain the useful metals. Coal, as
Vischers remarks, is now the indispensable aliment of industry; it is a
primary material, engendering force, giving a power superior to that
which natural agents, such as water, air, &c., procure. It is to industry
what oxygen is to the lungs, water to the plant, nourishment to the
animal. It is to coal we owe Steam and Gas; it replaces, in the work-
shops and the domestic hearths, the charcoal which had become too
costly. Under the last head, in our northern latitudes, it is destined
always to acquire increasing and more general use. The employment of
coal will henceforward be no other than a question of cheapness; as, in
the present age, the first intcrest of industry is, above all, to see amelio
rated the ways of communication-to lower the tolls upon the routes
and the canals. If custom-house officers still oppose shackles on manufactured
products, they lower their barriers for the passage of the raw material.
It is the lovers of antiquities, the laborious and painstaking anti-
quaries, who search out, recover, and rebuild in imagination the giant
castles, the abbeys, the nunneries, that once reared their proud pinnacles,
towers, and battlements in our land, and were peopled with men and
women who, although differing in dress, manners, and learning with
ourselves, possessed the same feelings of love and hatred, piety and pro-
fanity, simplicity and vanity, which abound in the well-dressed and
educated society of the nineteenth century. How many little things
dug out of the earth, such as hatchet and spear-heads, knives, pottery,
and coins, supply the learned antiquary with the light which discloses
the doings of our forefathers. Even the fair sex of ancient times are
re-embodied and dressed before the mind's eye, and bedecked with rude
ornaments; for are not their cists, or boxes, containing torques, armlets,
and rings, dug out occasionally? and even in localities now represented
by miles of peat-bog, there are discovered not only ancient British
ornaments, but even paddles or oars which are of the same form as
those used by the Welsh at the present day for their "coracles," or
little wicker boats covered with hides. But what has all this to do with
coal? Why, if brass ornaments, spear-heads, coins, &c., betray the
ancient haunts of man, the numerous remains of plants and stems of
trees, found in the coal and coal measures, surely betray the vegetable

IMPORTANCE OF COAL.
5
origin of coal, and tell us in the plainest language that this mineral fuel
is the remains of vast forests, and other large growths of innumerable
plants, which have lived, died, and have been entombed by the all-mer-
ciful hand of Providence thousands of years ago, and are now being
exhumed for our benefit, to give us health, in the shape of cheap
warmth, and wealth more abundant than the imaginary contents of
Aladdin's cave.
Fig. 2. Tropical Scene in Borneo.
The above illustration of a tropical scene in Borneo, the late home

6
COAL AND COAL MINES.
of the illustrious Sir James Brooke, Rajah of Sarawak, will afford
some idea of the exuberance of foliage prevailing commonly at the pre-
sent time; and it is presented in order to indicate what the coal such as
we have in England was not obtained from, and that we are not to sup-
pose, as it was formerly imagined, that the plants and forest trees grew
only in tropical climates, and were then transported by water-carriage
to the more temperate parts of the globe; but rather that a peculiar
condition of the atmosphere excited and maintained the wonderful life
and activity in the vegetable kingdom which prevailed at the period of
the formation of the coal measures, and that the forests grew at about
or near the localities where the coal is deposited at the present day.
The once familiar "Drift" theory which accounted for the production
of our British coal, supposed that vast forests were swept from the land
into the arms of the mighty ocean or into vast lakes, by continual in-
undations or powerful streams, just as the trunks and branches of trees
are swept from the banks of the river Jordan, and are carried into and
Fig. 3. The Dead Sea, from a Photograph by Negretti.
thrown up on the surface of the Dead Sea, to be again deposited, like
gaunt skeletons, on its shores; or on a grander scale, as by the over-
whelming volume of the vast rivers of the Mississippi or St. Lawrence,
in North America, where thousands of trees float annually down the
stream to the Atlantic, and are there deposited, with soil, sand, and clay,
in process of time, in the bed of the ocean,
GEOLOGICAL THEORIES.
r
7
"The Drift Theory" receives a further elucidation in the next simple
diagram of Professor Phillips. Thus, at the point A in the next
diagram, a series of limestone, sandstone, shales, coal, ironstone, occur,
these being the common names of the rocks which are associated with
coal. The limestone may be supposed to have been brought by dif-
fusion in the ocean from an area situated to the south-east, the shale
transported from the west, and the sandstone, plants, &c., drifted from the
north. We may imagine two rivers, one flowing from the west, and
NORTH

Coal
Sundstone
WEST
A
Shale
EAST


Limestone
SOUTH
Fig. 4. Illustration of Drift Theory.
bringing across the regions where now are Ireland, Lancashire, Derby-
shire, and South Yorkshire, a vast body of argillaceous (clayey) sedi-
ments, slightly charged with sand, and but little varied by floating trees
and plants; the other rushing from the north, loaded with sandy
matter, and bearing abundance of trees of different kinds, but not many
ferns or delicate herbaceous plants. Alternately, or contemporaneously,
these rivers might fill the sea with deposits such as we behold, and in
the manner that we see them united with the proper calcareous deposit
of the ocean." In appreciating the "drift theory," it must be remem
8
COAL AND COAL MINES.
bered that the "ancient ocean "is supposed to have been very different
from the present one, and the arrangement of land and water quite dis-
similar to the present order of these ancient elements. The Northern
Ocean, at the commencement of the coal period, was, it is supposed,
divided into basins, varied by islands, bounded by shores, supplied by
inundations from extended land. One of the most interesting localities
presenting an analogy to the dense island forests of the ancient coal
period is one of a group of islands called the Great Andaman Islands,
situated in the Bay of Bengal, and about one hundred and forty miles
long and twenty broad. The extreme thickness of the tree jungles

Europe
Allanlic
Asia
Africa
·
Fig. 5. The Earth before the Separation (Snider's Diagram).
which cover nine-tenths of this island, renders it almost impenetrable,
they being composed of trees as straight as arrows, of from thirty to
forty feet high, though their roots cannot expand much beyond one foot,
and are found twisted together like so many coils of rope. The foliage
LAND AND WATER.
9
is confined to the tops of the trees, the trunks of which are leafless and
branchless. The wood of the jungle trees is very hard, so that the axe
flies off them as from stone. There seems to be no grass whatever,
a great lack of water, and no rivers, but only brooks, which are dry in
the summer and torrents in the rainy season. There are no wild animals
except rats, snakes, and very little pigs, and all attempts to establish
any intercourse with the aborigines have failed.
The agitation of the shores of the Northern Ocean," says Phillips,
"is proved by conglomerates (matter rolled like currant dumplings into
balls); the amount of inundations from the land is demonstrated by an
abundance of clayey and sandy sediments, plants, and beds of coal;
while in the more tranquil laboratory of the deeper water, limestone
rocks were generated in great abundance.'
M. A. Snider, in a work entitled "La Création et ses Mystères
dévoilés," gives two diagrams which are intended to show the alteration
of the relative positions of land and water on the surface of the globe
since its creation.
At this period (Fig. 5) M. Snider supposes the earth to have been one
continuous block or mass rising out of the ocean, and the space marked
the Atlantide (the Atlantic) to have been formerly dry land, but_now
changed to the bed of the mighty Atlantic Ocean. Sir Charles Lyell
says, "It can be shown that the earth's surface has been remodelled
again and again; mountain chains have been raised or sunk; valleys
formed, filled up, and then re-excavated; sea and land have changed places;
yet, throughout all these revolutions, and the consequent alterations
of local and general climate, animal and vegetable life has been sus-
tained.
"This has been accomplished without violation of the laws now
governing the organic creation, by which limits are assigned to the
variability of species. The succession of living beings appears to have
been continued, not by the transmutation of species, but by the intro-
duction into the earth from time to time of new plants and animals, and
each assemblage of new species must have been admirably fitted for the
new states of the globe as they arose, or they would not have increased
and multiplied and endured for indefinite periods.'
دو
The eminent naturalist, Mr. Charles Darwin, in his work "On the
Origin of Species by means of Natural Selection, or the Preservation
of Favoured Races in the Struggle of Life," is opposed to the theory
of the introduction of new species and new plants, and insists on the
natural provocation to variety, and he says, "The more living beings
can be supported on a given area, the more they diverge in structure,
habits, and constitution; therefore, the more diversified the descendants
of any one species become, the better will be their chance of succeeding
in the battle of life. It is a truly wonderful fact-the wonder of which
we are apt to overlook from familiarity-that all animals and all plants,
throughout all time and space, should be related to each other, in group
subordinate to group in the manner which we everywhere behold-
namely, varieties of the same species most closely related together;
10
COAL AND COAL MINES.
species of the same genus less closely and unequally related together,
forming sections and sub-genera; species of distinct genera much less
closely related; and genera related in different degrees, forming sub-
families, families, orders, sub-classes, and classes. The usual subordinate
groups in any class cannot be ranked in a single file, but seem rather to
be clustered round points, and then round other points, and so on in
almost endless cycles. On the view that each species has been inde-
pendently created, I can see no explanation of this great fact in the

S America
4.
Europe
Alricu
•
As all
Fig. 6. Arrangement of the Land after the Separation (Snider's Diagram).
classification of all organic beings; but, to the best of my judgment, it
is explained through inheritance and the complex action of natural
selection, entailing extinction and divergence of character.
living forms of life are the lineal descendants of those which lived long
before the Silurian epoch, we may feel certain that the ordinary succes-
sion by generation has never even been broken, and that no cataclysm
[deluge] has desolated the whole world."
THE DRIFT THEORY.
11
The second diagram (Fig. 6) represents the same terrestrial globe after
the division of its parts at the surface, with the formation of the North and
South Atlantic Ocean. The great uniformity of the fossil plants of the
coal measures of Europe and North America is a convincing proof of the
former existence of a continent or chain of islands where the Atlantic
now rolls it waves. Four-fifths of the fossil coal plants collected in
Nova Scotia have been identified with European species; and there are
also other geological proofs of the existence of an ancient land situated
to the eastward of the present Atlantic coast of North America.
500 B.C. Herodotus mentions fossil fishes as occurring in the rocks of
Egypt, and states this as a proof of that country having been formerly
an arm of the sea, like the Red Sea. Without advocating the truth of
the first diagram, enough has been said to indicate some of the points of
the "drift theory," by which it is attempted to explain the origin of coal.
The opponents of the "drift theory," it must be admitted, bring
formidable arguments against it; and the following objections, arranged
in a condensed form under seven heads, by the late Mr. G. F.
Richardson, may not be uninteresting.
1. The purity of coal, and its freedom from extraneous substances.
Had it been drifted, it must have acquired some portion of foreign sub-
stances in its transit, such as pebbles, gravel, &c.; but since we find
extensive seams of coals unmixed with any other matters, its freedom
from these is considered to be incompatible with the idea of its having
been drifted from a distance.
2. The generally uniform thickness of each coal seam is considered to
offer another difficulty. The lower main seam of the great northern coal
field, according to Mr. Bowman, extends over at least two hundred
square miles, while a thin seam is pointed out as reaching in a straight
line from Whaley Bridge to Blackburn, a space of thirty-five miles. Had
the coal been washed away by floods or torrents, such currents, either
from the different specific gravity of portions of the same mass-of the
roots and stems, for example, as contrasted with the branches and
foliage or from the mechanical destructions occurring in such a transit,
would have deposited them in an unequal manner; whereas no such
effects are discernible in the coal seams, which are invariably free from
inequalities of this kind.
3. The exceeding minuteness of many of the coal seams, which thin
out into mere filaments, and extend in this condition over extensive
areas of solid rock, militates against the idea of any deposit of so at-
tenuated a nature having been spread over spaces so large by the act of
drifting.
4. On the other hand, the size of many of the coal seams considered with
reference to the immense compression which they have unquestionably un-
dergone, is considered to furnish another objection of insurmountable cha-
racter. The enormous extent to which the bulk of substances may be re-
duced by pressure, can scarcely be imagined, except by a reference to exact
computation. It was ascertained by Mr. Burr, that a mass of rubbish
which was left in a worn-out vein of ironstone, during a period of ten
12
COAL AND COAL MINES.
years, was in that interval reduced from seven to two feet in thickness,
owing to the pressure of the overlying weight. It was further changed
into so hard a substance as to form a mass of rock which could only be
penetrated by the operation of blasting. When we consider the great
compressibility of vegetable matter, and reflect that beds of coal have
been subject to the pressure of masses of rock many thousand feet in
thickness, during a period of countless ages, and when we recollect that
matter so compressed has formed beds of great relative thickness, it is
evident that, for the formation of such deposits, supplies on the most
enormous scale would be required, and that it would be utterly impossible
to transport masses of vegetable substances so immense as would be re-
quisite for the formation of the coal deposit alone.
of
The effect of great pressure produced by Bramah's hydrostatic press is
well illustrated in the compression of the bales of Manchester cottou goods,
and of all kinds of paper, gunpowder in the stage of press cake, compressed
trusses of hay, candle-making, seed-crushing and pressing, whilst the con-
stant downward pressure of the superincumbent strata will be explained
more fully afterwards in what are called "Creeps," when the earth, or
floor, or metal of the excavated galleries in a coal pit gradually rises
and fills the spaces left between the pillars of coal that support the roof.
5. The high state of preservation in which many of the plants occur,
the perfect condition of the leaves and parts of fructification of many
the ferns, the sharp angles of numerous stems which are pronounced to
have been of a soft and succulent nature, with the surfaces of Sigillarie
marked with lines, streaks, and flutings so delicate that the mere
drifting of a day would have inevitably destroyed them. These, with
other facts of a like nature, convince us that these plants have never been
subjected to drift, but were buried on the spots where they lived and died.
6. An additional objection to the drift theory is founded on chemical
facts;
it has been urged, that if vegetable matter were swept away by a
flood, such an agency, by allowing the gaseous elements to escape, would
be inadequate to produce the desired results, and that coal never could
be formed by such a process.
7. The multiplied instances of trees found erect, establish the fact
of the coal plants having chiefly grown on the spot where they are now
entombed.
Midway between the "drift" and "submergence" theories, it will
be perhaps instructive to pause in order to mention a theory which has
been urged with great power and ingenuity by Mr. Evan Hopkins, C.E.
—viz., the actual movement of the crust or outer crystalline shell of the
earth as it were in a spiral direction from the South to the North Pole;
so that any given country like Great Britain shall, in process of time (to
be numbered by thousands of years), have its position moved from a
warm to a colder latitude by the mechanically-destructive and chemically-
solvent power of water, aided by electro-chemical currents and crys-
tallization, just as a plate of copper may be gradually dissolved at the
positive pole of the battery, and again deposited at the negative pole
to form an electrotype. Mr. Hopkins is entirely opposed to the Plutonic
EVAN HOPKINS'S THEORY.
13
theory, and warns his hearers not to look at the strata of the earth
through "red spectacles," but to admit a little more "soda water"
(having a cooler and quieter agency in this globe than fire) into their
speculations as to the formation of rocks. The arguments most forcibly
used in favour of the idea of a movement of the earth's surface from
south to north by the electro-magnetic currents are: 1. The changes of
latitude which have occurred in various recorded instances.* 2. The re-
sult of the change of latitude-viz., change of climate. Hence it is urged
that formerly England was differently placed, and enjoyed a tropical or
warmer climate; and during that period the coal-plants grew and ex-
panded into those gigantic proportions which seem to be the speciality of
the flora of the coal-measures. Could elephants live in Siberia at the
present time? yet the remains of these warmth-loving animals are found
in abundance there. Wines were formerly made of the grapes grown in the
open fields of England; and it is stated that when Cæsar invaded Britain
1915 years ago, the site of the city of London was in latitude 40° 30',
and therefore in a climate corresponding to that of Portugal, which
gives us our much-loved "Port;" whereas now we know that the
latitude of Greenwich is 51° 28′ 38″.
The second theory that accounts for the production of coal may
be called "the Theory of Submergence," in contradistinction to the other
already discussed, called the Drift Theory.
It is assumed that there was a period in the history of our globe
when a damp and steamy heat, with incessant rains and an atmosphere
highly charged with carbonic-acid gas, prevailed on the surface of the
earth. Then repeated storms, lightnings, and the fearful thunder broke
only upon the solemn silence that prevailed; for, as Hugh Miller says,
"no human being had yet left an imprint of his foot on the soil where the
coal plants grew.
This damp and steamy heat our artist has endeavoured to portray
in the next picture, where we see the sun vainly struggling to send
his rays through the atmosphere highly saturated with vapour. Such
an atmosphere may be partly realized by a visit to any gardener's
forcing-house, and would of course be the means of increasing enor-
mously the rank growth of the underwood and trees of the coal forests,
whilst the continuous rains would wash down and dissolve out of the
atmosphere the carbonic-acid gas, carrying it to the roots of the plants
in that liquid state best adapted for its assimilation. If we could
imagine a plant taking a breakfast, dinner, and tea, carbonic-acid gas,
like our "daily bread," would always form a part of each meal. Then,
again, the repeated storms and excess of demonstrative electricity, the
continual flashes of lightning, no doubt produced soluble nitrogenous
matter, such as nitric acid, which was in like manner supplied to those
plants that required it for their sustenance.
Of the presence of the carbon (of the carbonic-acid gas) and the
nitrogen (derived possibly from the nitric acid) in coal we have abun-
* Usually explained astronomically by the phenomenon called the "Precession of the
Equinoxes."

11
COAL AND COAL MINES.
dant evidence; and of the rain that undoubtedly fell at that period in
such unusual quantities, there are the stony records in the rocks asso-
ciated with coal. The sandstone and green shale, especially in those
specimens collected by Mr. Brown from Cape Breton, Nova Scotia,
bear upon their surfaces indubitable marks of rain-drops.
Fig. 7. The humid Atmosphere and rank Vegetation of the Coal Period.
The damp heat, the constant supplies of nutritive matter, brought
about a gigantic condition of the plants and trees which reminds us of
the huge root displays of modern horticultural shows, with their giant

THE RAIN-PRINTS OF THE COAL PERIOD.
15
beetroots, colossal turnips, carrots, &c. The effect of this stimulating
action was to make the most humble plants spring up into forest trees;
thus there were trees in the coal flora allied to the club-moss tribe,
nothing but a tender bit of moss, and yet these plants shot up into
b
Fig. 8. Rain-prints and Worm-tracks (a b) from the upper and under surface of green
shale rock from Cape Breton, Nova Scotia. c c. Shrinkage-cracks and Rain-prints on the
under side of a layer of sandstone rock. i. Dog's Foot-print, made July 17th, 1850, on recent
mud of the Bay of Fundy; removed by Sir Charles Lyell immediately after the impression
was made, and showing how such records (as the rain-prints) may be left of past events,
The latter copied from specimens in the possession of Professor Tennant, 149, Strand..

16
COAL AND COAL MINES.
large trees from thirty to forty feet in height. It is interesting to know
that the same wonderful activity of the vegetable kingdom is to be
observed, to a great extent, in many forests at the present day, and
especially in the West Indies; there, plants, which in our climate might
be elegant creepers, such as the jasmine and clematis, fit to train on the
Fig. 9. Traveller in West Indian Forest; Accident from overhanging Creepers.
walls of a pretty cottage, grow up, under the effects of a West Indian
climate, into great ropes and cables, which intertwine and hang from
tree to tree, and must be carefully avoided in attempting to ride through
these forests, or the incautious traveller may find himself suddenly en-
tangled and lifted from his horse.

THE FLORA OF THE COAL PERIOD.
17
The great humidity of the climate of the coal period had been pre-
viously inferred from the nature of its vegetation and the continuity of
its forests for hundreds of miles; but it is satisfactory to have at length
obtained such positive proofs of showers of rain, the drops of which
resembled in their average size those which now fall from the clouds.
From such data we may presume that the atmosphere of the carboni-
ferous period corresponded in density with that now investing the globe,
a
d
b
e
Fig. 10. Remains of Fossil Stems and Plants of the Coal Measures. a. A Calamite.
b, c. Sigillariæ. d. Lepidodendron. e. Stigmariæ, root of the Sigillaria
C
18
COAL AND COAL MINES.
·
and that different currents of air varied then as now in temperature, so
as to give rise, by their mixture, to the condensation of aqueous vapour.
-Lyell's "Geology."
It might, however, be supposed that all statements with respect to
the origin of coal must be imaginary, and partake only of the fascinating
nature of fiction. No; the skeleton remains of plants which enable
the botanist to revivify the dead forests of the carboniferous period are
continually coming to light as the coal is dug from its rocky bed.
In Fig. 10 we have ferns-calamites, bamboo-jointed-reed-like plants,
Lepidodendra-and, more curious than all others, here are the sigillariæ,
which scarcely present any analogy with existing forms, and must have
imparted, as Miller says, a strange and wondrous character to the
flora of the coal measures."
cr
The ferns appear to have been the most abundant, at least if our
judgment in this respect is to be formed from the fossil specimens
already obtained. There seems, however, very good reason to believe
that we cannot make a just estimate of the exact proportion of one kind
of plant, or of its superabundance as compared with others, because
it would naturally happen that there might be a great difference in
the capabilities of certain plants of resisting the action of water longer
than others, and therefore our ideas of the precise state of the flora at
the time of the growth of the great coal-producing vegetation of the
forests must be somewhat obscure.
In order to assist the student of paleontology, or study of fossil
plants and animals, it is advisable to keep the following table constantly
în view, as it demonstrates the names of the groups of plants so often
alluded to-
Cryptogamic.
Phanerogamic.
BRONGNIART.
1. Cryptogamous Amphigens, or
cellular Cryptogamia
...
2. Cryptogamous Acrogens...
(3. Dicotyledonous Gymnosperms
LINDLEY.
Thallogens
Acrogens
...
Gymnogens
4. Dicotyledonous Angiosperms... Exogens
5. Monocotyledons
...
Endogens...
Lichens, Sea-weeds,
Fungi.
Mosses, Equisetaceæ,
Ferns, Lycopodiums,
Lepidodendrons.
.Conifers and Cycads.
Compositæ, Legumi-
nosæ, Umbelliferæ,
Cruciferæ, Heaths,
&c.
All native European
trees except Coni-
fers.
Palms, Lilies, Aloes,
Rushes, Grasses.
The term cryptogamic is of course derived from the Greek крUπтOS
and yapos, concealed fructification, and is applied to a class of plants
whose stamens and pistils are not distinctly visible.
The thallogens, or flowerless plants, which have no proper stem or
leaves, such as lichens, seaweeds, and fungi, are remarkable for certain

THE FLORA OF THE COAL MEASURES.
19
characteristics peculiar to all; they are entirely formed of cellular
tissues, or rather of interlacing tubular filaments, without vessels
properly so called; they never present true leaves, and their organs of
reproduction consist only of very fine seedlings, which appear to de-
b
a
d
Fig. 11. a. Pecopteris. b. Lepidodendron. c, d. Calamites. e. Lepidodendron.
J. Sigillaria. All drawings of fossils in Professor Tennant's Collection.
velope themselves without fecundation, and are immediately enclosed in
membranous conceptacles analogous to the filaments of that tissue
C 2
20
COAL AND COAL MINES.
which composes the whole of the plant. The only fossil plants of this
class known are some conferve with several alga, or seaweeds.
The second class comprises cellular cryptogamiæ, or mosses, which
present in their general form and structure features similar to those of
the most perfect vegetables; in this class are also grouped the Equise-
taceæ, Ferns, Lycopodium, Lepidodendrons, which possess more varied
tissues, and include perfectly distinct vessels, and very frequently spiral
vessels, or imperfect spiral vessels, while the leaves are in general very
fully developed and furnished with cortical pores. The stems, often
large and arborescent (Figs. 10 and 11), have some analogy with those of
Monocotyledons, or plants having one seed-lobe. M. Adolphe Brongniart
has called the period of the formation of the coal measures the age of
Acrogens, in consequence of the vast preponderance of ferns, and Lepido-
dendra, and the apparent absence of Exogens, or ordinary Dicotyledons,
or plants having two seed-lobes; nevertheless, Lyell supposes a forest
of that period may have borne a considerable resemblance to those woody
regions of New Zealand, in which flourished ferns, arborescent and herba-
ceous, and lycopodiums, with many coniferæ, or pine-trees, probably similar
to the Wellingtonia gigantea, depicted at page 3, the bark of which is
deposited and built up in the north transept of the Crystal Palace,
Sydenham. With reference to this gigantic specimen, Lord Richard
Grosvenor, in a letter dated November 3rd, 1859, and addressed from
San Francisco, California, says:

ઃઃ
"I have just been on a trip into the interior of this State to see the
'big trees,' and they are worth coming here to see. Imagine a tree 116
feet in circumference, and 450 feet high! There are several groves of
them, all on the western slope of the Sierra Nevada, and all about the
altitude of 4000 feet above the level of the sea. I have been to see two
of them: one in Calaveras county, and the other grove in Mariposa,
both about 200 miles from here, and the latter in a south-westerly direc-
tion. They are beautiful trees, but I do not think the branches are
large enough in proportion to the trunk; they are, in fact, very small,
and hang down in a nearly perpendicular fashion, sometimes bending
down in a semicircular arch, so as to touch the trunk again, which
makes them rather look like very tall masts. The trunk is beautifully
proportioned, and tapers off to a fine point, so you do not appreciate the
height till you find you have sprained your neck in trying to see the
top. The bark is a pretty yellowish cinnamon colour, of a very fine
texture, often twenty-two inches thick; but that you have seen at the
Crystal Palace. The tree from which that bark was taken is still standing,
with the scaffolding round it which was used on the occasion."
The Phanerogamic group includes those plants which have visible
flowers containing stamens and pistils.
The most remarkable plants or trees belonging to the coal period were
undoubtedly the Sigillaria, with their vast roots called stigmariæ, of
which about thirty-five species are known; and such was their indivi-
dual abundance, that there are great seams of coal almost entirely com-
vosed of them. These "trees were interesting," as Miller says, on
SYMMETRY OF THE TRUNKS OF THE SIGILLARIÆ.
21
account of their beautiful sculptured stems, various in their pattern
according to their species." All were fluted vertically, somewhat like
columns of the Grecian Doric, and each flute or channel had its line of

Fig. 12. A Grecian Doric Column, for Comparison with a Sigillaria Stem (p. 17).
rr
sculpture_running adown its centre, as we may notice in Fig. c, p. 17.
In walking amongst the ruins of this ancient flora, the palæon-
tologist almost feels as if he had got among the broken fragments of
22
COAL AND COAL MINES.
Italian palaces erected long ages ago, when the architecture of Rome
was most ornate, and every moulding was roughened with ornament;
and in attempting to call up in fancy the old carboniferous forests, he
has to dwell on this peculiar feature as one of the most prominent, and
to see, in the multitude of trunks darkened above by clouds of foliage,
that rise upon him in the prospect, the slim columns of an elder
Alhambra roughened with arabesque tracery and exquisite filigree work."
Having thus briefly attempted to give some idea of the flora of the
dark and tangled forests of the coal period, our thoughts must be again
directed to the process by which these tall tree-ferns, huge pines, reed-
like calamites, sculptured sigillariæ, and hairy lepidodendrons were sub-
merged, decomposed, condensed, and hidden for ages beneath the surface
of the earth.
It is a subject of everyday observation to those who delight in
country walks amid field and common, copse and wood, that wherever
due regard is not paid to the all-important first principle of agriculture,
viz., drainage—wherever water is allowed to accumulate, the soil, by
being constantly saturated with moisture, is no longer able to admit the
health-giving atmosphere, and in process of time the useful vegetation
dies away, sinks down into and is decomposed in the morass, being suc-
ceeded by a rank and sour crop, which even the much-despised donkey
will not condescend to touch. In a somewhat similar manner, though
gigantic in degree, it has been assumed that water gradually invaded
the vast forests, and saturating the earth, filled up all the pores and
excluded the air, and from the circumstance of carbonate of iron being
a constant companion of the coal seams, it may be imagined that the
falling leaves and the tangled underwood, rotting in the watery bed, con-
verted the peroxide or red oxide of iron in the soil (which is a valuable
ingredient of the earth that supplies the healthy plants with food)
into poisonous protoxide or green oxide, and directly this mineral poison
began to act upon the forest trees they gradually died, and were sub-
merged by the reception at intervals of deposits of silt and mud, the
detritus of neighbouring and higher land.*
When the forest grew on the banks of broad and shallow lagoons or
vast lakes the water would teem with vegetation, and might gradually
supply materials for beds of peat. These lagoons, covering, perhaps,
miles of country, by repeated sinkings may have subsided gradually
beneath the level of the sea, and have rendered the basin the receptacle
*We are indebted to Kremer for careful analyses of the ashes of coal, of which we
give an example, the per-centage of ash in the coal being 1.99, and its composition as
follows:-
Silica
Alumina
Peroxide of iron
...
...
..
...
...
..
15:48
...
...
...
...
...
5.28
...
74.02
Lime
Magnesia
...
...
...
Potash
...
2.26
...
...
0.26
0.53
...
...
...
...
...
2.17
...
...
...
...
...
100'00
Soda ...
Sulphate of lime
DEATH AND SUBMERGENCE OF THE FLORA.
23
of alternating deposits of sand and clay, and may thus have produced
the strata of sandstone and limestone which occur between the seams
of coal. Such ideas respecting the inroads of the sea are supported by
facts that are apparent at the present day-as, for instance, the remark-
able rising of the tide in the Bay of Fundy, which is a large inlet of
the Atlantic Ocean, and situated on the east coast of North America;
the bay, separating the south part of the peninsula of Nova Scotia
from New Brunswick, extending about 100 miles, with an average
breadth of about 30 miles.
The tides in this bay frequently rise to the great height of 60 feet,
and are, as may be supposed, very destructive; they sweep away the
whole face of the cliffs, and thus a new crop of erect trees springs up
about every three or four years. Rogers imagines that the areas now
covered with the coal formation have possessed a physical geography,
of which the principal feature was the existence of extensive flats
bordering a continent, and forming the shores of an ocean, or some vast
bay, and that this low coast was fringed by great marshy tracts or peat
bogs, on which along the landward margin grew the conifere, tree-ferns,
lycopodiacea, and other arborescent plants. If the fossils discovered in
the coal measures were all of freshwater origin, the supposed effects of
the sea would be purely imaginary; but there is abundant evidence of
the mixed nature of the fossil remains, and of the association of fresh
or brackish water with marine strata, not only in American, but also in
the English coal fields. In the lower coal seams of Colebrookdale, in
Shropshire (celebrated as the locality where railroads formed of wood
were first used in the year 1620 and 1650, and about 100 years after-
wards plated with iron), Mr. Prestwich suggests that the intermixture
of beds containing freshwater shells, with others full of marine remains,
and the alternation of coarse sandstones and conglomerate with beds
of fire-clay, or shale, containing the remains of plants, may be explained
by supposing the deposit of Colebrookdale to have originated in a bay
of the sea or estuary, into which flowed a considerable river subject to
occasional "freshes," or the mingling of fresh with salt water.
In the Edinburgh, Shropshire, and Staffordshire coal fields, also in
those of South Wales and Somersetshire, the marine deposits are more
or less associated with those of freshwater origin. Some geologists,
and especially E. de Beaumont, have assumed, in order to account for
the frequent alternation of coal seams and sedimentary rocks with marine
products, a continuous sinking of islands, so that each coal seam was
covered with sediment up to the level of the sea, and a new flora after-
wards grew there, which was in its turn sunk below the water, and
so on.
With respect to the production of the poisonous protoxide of iron,
and its effect upon the forests of the coal period, it is interesting to
know that Professor Hunt, of the Museum of Practical Geology, has
instituted a series of experiments, to illustrate the production of clay
ironstone, bands and nodules of which are so common in the coal
measures; and he has found that decomposing vegetable matter (such as
24
COAL AND COAL MINES.
would be distributed through all the coal seams) prevents the further
oxidation of the proto-salts of iron, and converts the peroxide into
protoxide, by taking a portion of its oxygen to form carbonic acid gas.
This gas coming in contact with the protoxide of iron in solution,
would unite with it and form a carbonate of the protoxide of iron, and
mingling with the excess of fine mud, might form beds or nodules
of argillaceous or clay ironstone. When pure, carbonate of iron is com-
posed of
Protoxide of iron
Carbonic acid
61.37
38.63
100.00
The carbonate of iron ore occurs in flattened nodules in connexion
with the coal at St. Etienne, a locality we shall again allude to, and is
composed of
Carbonic acid
Protoxide of iron
دو
Lime
Magnesia.
Silica
Alumina
38.4
41.8
•
manganese.
4.1
0.2
0.3
12.3
3.2
100.3
Speaking again of the inroads of water, there is a very interesting
example of the effects of such natural causes in the marsh lands which
once formed an estuary or arm of the Bristol Channel, and the formation
of extensive peat bogs on what are provincially termed the Turbaries.
The levels are about two hundred square miles in extent, and at the
present time a great part of those flats are below the level of the spring
tides, but barriers formed by nature and improved by art keep back the
sea. In ancient times the low lands became a morass or lake of fresh
water, and in such situations commenced the formation of peat. The
changes are interesting, and afford a good notion of the probable
formation of many coal seams; and they are thus described by an eye-
witness, who writes so pleasingly in "Chambers' Journal." He says:-
First, the reeds spring up, because they can raise themselves out of
the water; then other aquatic plants help themselves up by the stalks
of the reeds, till at length the confervæ thicken the mass so much that
the surface becomes suitable to the sphagnum tribe, to which succeed
lichens, rushes, and grasses. This spongy mass of vegetation con-
solidates, sinks below the surface, falls to the bottom, and there decays,
receiving year by year a fresh accumulation. This decomposed matter
becomes a semi-fluid and dark-coloured substance, which undergoes
fermentation, hence the bituminous and inflammable properties of peat,
into which this homogeneous mass is now converted. In this process
nature requires that the water should be quiescent, for should any
current disturb the stagnant morass, it would carry off the astringent
cr
DEATH AND SUBMERGENCE OF THE FLORA.
25
juice, which is the chemical agent for turning the decomposed vegetable
mass into peat. The 'moss water,' as it is called, is highly antiseptic,
and of so astringent a nature, that an attempt was made some years ago
to apply it to tannery purposes. The thickness of this congeries of
plants is from fifteen to eighteen feet; it is kept buoyant by the water
in the basin, and assisted, no doubt, by the clinging bubbles of gas
derived from its partial decomposition. In winter, the peat rises so
much above the level of the surrounding land, that people who live on
the borders of the turbaries cannot see objects which are clearly
discernible in summer."
The State of Michigan, in America, is remarkable for the abundance
and value of its peat deposits. In this locality the peat beds are more
condensed and compact, being comparatively shallow, and seldom
exceeding four feet in thickness. It most commonly overlies beds of
calcareous marl, which has accumulated in the innumerable low meadows,
beaver swamps, and wet prairies of the country. Michigan has been
aptly designated by the Indians as "The Land of Lakes;" and a pro-
fessional geologist has reported on the existence of not less than three
thousand lakes within the limits of the peninsula. The condition of a
vast territory, like that of the new States of America, thinly peopled,
and with its swampy lakes undrained, supplies a good illustration of the
probable condition of thousands of miles of the surface of the earth
when the flora of the coal measures attained their gigantic proportions.
It is stated that peat taken from land which has been many years
drained, when dried, is nearly as heavy as oak wood, and bears about the
same price in the market of Rhode Island, where peat abounds.
In the more ancient periods, after the peat was formed in the moist
state, accidental drainage, from alteration of the levels, might occur,
with its gradual submergence and condensation; and so, in the course
of hundreds of years, coal would be produced. The analysis of New
Hampshire peat by Messrs. Whitney and Williams is as follows:-
Locality.
Meredith
Canterbury.
Franconia
Vegetable
matter.
94.90
93.80
73.70
Silica, alumina,
iron, and lime.
5.10
6.20
26.03
Baron Liebig considers that wood, or brown coal and mineral coal
are the remains of vegetables of a former world, and that they are
the results of decompositions termed decay and putrefaction. Woody
fibre and linen both contain a proximate principle termed lignin, so that
there is a great connexion between the two, so far as their chemical
composition is concerned. When heaps of rags are moistened with
water they become warm, carbonic-acid gas is evolved, and their weight
diminishes from eighteen to twenty-five per cent., and the rags are
converted into a soft, friable mass, which has lost its coherence. When
sawdust is moistened with water, it also evolves considerable heat,
which in the presence of other combustible matter has even increased
until flames have burst forth from the mass. The author recollects a
26
COAL AND COAL MINES.
case of this kind, where the contents of an underground dustbin,
which had been nearly filled with sawdust, took fire spontaneously, and
where the whole mass of sawdust was found to be blackened, and caked
together into a porous coal-like mass. Pressure and temperature have
greatly affected the decomposition of the ancient submerged vegetation.
A piece of wood, which had been placed in the boiler of a high-pressure
steam engine, and subjected to a temperature of between 334° and
352° Fahr., with the corresponding pressure of between seven and a half
and nine atmospheres, was found to be converted into a species of coal,
which had precisely the same composition as Laubacher coal.
A piece of wood swallowed by a pig and retained in the stomach,
causing its death, was examined by the author, and had very much the
appearance of petrified wood. Decomposition of coal is continually
going on, and gases eliminated from it. In the vicinity of a layer of
wood coal in Germany the springs of water are usually found to be
highly charged with carbonic acid. The wood coal by analysis is found
to contain the exact elements of woody fibre or lignin minus a certain
quantity of carbonic acid. The gases formed in mines of wood coal,
causing danger in their working, are not combustible or inflammable as
in mines of mineral coal, but they consist generally of carbonic acid gas,
and are very seldom intermixed with combustible gases. The combus-
tible hydrocarbon called carburetted hydrogen, generally accompanies.
all mineral coal, and is usually found mixed with nitrogen gas, car-
bonic acid gas, and sometimes olefiant gas, being called "fire damp."
The constant evolution of these gases from coal in coal mines, proves
that changes are always proceeding in the coal; and Liebig adds: "It
is obvious that a continual removal of oxygen in the form of carbonic
acid is effected from layers of wood coal, in consequence of which the
wood must approach gradually to the composition of mineral coal." This,
however, Bischof denies, and states that in no case can carbonic acid
exhalation originate from brown coal: he further says, at every part
of the earth where observations have been made, the temperature in-
creases with the depth below the surface. If this same increase goes
on at depths which are inaccessible, there must be a red heat at a cer-
tain depth. If at this depth there are beds of carbonate of lime, car-
bonic acid would be disengaged from them in the same way as in
limekilus. Hydrogen, on the contrary, is disengaged from the consti-
tuents of mineral coal in the form of a compound of carbo-hydrogen; a
complete removal of all the hydrogen would convert coal into anthracite.
According to Liebig's view, the conversion of ligneous fibre into coal
consists in the separation of certain quantities of its elements in the
orm of oils, marsh gas, and carbonic acid.
When from the formula representing the composition of wood there
are deducted three equivalents of marsh gas (carburetted hydrogen),
three equivalents of water, and nine equivalents of carbonic acid, there
remain the constituents of the splint coal of Newcastle and the canne
coal of Lancashire.
One of the most interesting statements with respect to coal deposits
THE UNDERCLAY OF COAL SEAMS.
27
The
is that made regarding the "clay floor" which generally accompanies
and forms the base on which the fuel rests. If an artificial pond or lake
is to be formed, the porous nature of the soil in which it may be dug
must be changed by lining the whole of the excavation with clay. How
natural, then, that water accumulations which helped to destroy the
ancient forests should take place on a clay base. Lyell says that "in
South Wales the coal measures have been ascertained by actual mea-
surement to attain the extraordinary thickness of 12,000 feet, the beds
throughout, with the exception of the coal itself, appearing to have
been formed in water of moderate depth, during a slow, but perhaps
intermittent depression of the ground, in a region to which rivers were
bringing a never-failing supply of muddy sediment and sand.
horizontal extent of some seams of coal is much greater than that of
others, but they all present one characteristic feature in having each of
them what is called underclay. These underclays, co-extensive with
every layer of coal, consist of arenaceous (sandy) shale, sometimes called
firestone, because it can be made into bricks which stand the fire of a
furnace; they vary in thickness from six inches to more than ten feet;
and Mr. Logan was the first to announce to the scientific world, in
1841, that they were regarded by the colliers in South Wales as an
essential accompaniment of each of the one hundred seams of coal met
with in their coal fields. They are said to form the floor on which the
coal rests; and some of them have a slight admixture of carbonaceous
matter, while others are quite blackened by it. What a commentary
on drainage is here supplied; the sturdiest forest trees sunk down into
decay when the water accumulated at their roots, how much more,
then, delicate plants, such as grasses, cereals, and other crops in the
agriculture of man. Another curious circumstance is that all the
"floors" are characterized by enclosing a peculiar fossil vegetable de-
posit called "Stigmariæ;" the latter was formerly supposed to be an
aquatic floating plant, but is now ascertained to be the root of the
sculptured Sigillaria. It was also observed that while in the strata
lying on the coal or the roof of the coal, ferns and trunks of trees
abound without the stigmariæ or roots, and are flattened and compressed,
the latter in the underclays always retain their natural forms, branch-
ing freely, and sending out their rootlets through the mud in all direc-
tions. With the "stigmaria" we arrive, as it were, at the very base or
foundation of coal, and our ideas of the truth of the "Submergence
Theory" receive a fresh impulse when we grasp these important facts,
described by Mr. Logan, which are supported by other and similar
geological strata.
If all our coal was not worked in the dark and under the surface of
the earth, a great many interesting fossil remains would come to light,
and much information be gained on this important subject; occasionally,
however, the coal does outcrop or come to the surface, and then being
quarried out, with the adjoining rocks, like stone, presents the appearance
indicated in our next picture, which is that of the celebrated coal mine of
Treuil at St. Etienne, in the department of the Loire, in France. Here

28
COAL AND COAL MINES.
the coal occurs in beds, which are evidently horizontal, and tracing
up the strata from the level of the feet of the figures in the lower
part of the picture, we have first coal five feet thick, then a bed of
siliceous shale, then a layer of carbonate of iron ore in flattened nodules,
and, ascending the path to the right, we Lave at the summit several thin
seams of coal, more shale, more iron ore, and, finally, a bed of mica-
ceous sandstone from eleven to thirteen feet in thickness, traversed by
vertical trunks of monocotyledonous vegetables resembling branches or
large Equisetaceae, as it were petrified in the very places where they
formerly stood as living trees.
Fig. 13. The Coal Mine of Treuil, at St. Etienne, in the Department of the Loire, France.
Mark Brongniart, in his account written in 1821, very properly in-
ferred that these fossil trunks were the monuments of a veritable
submerged forest; and although Lyell at first objected to this conclusion,
in consequence of the absence of roots, which he asserted ought to have
been found at one and the same level, and not scattered irregularly
through the mass, he has since withdrawn these objections, and has now
little doubt, from his observation of similar remains near Picton, in Nova
Scotia, that Brongniart's view is correct. These plants flourished, in a
sandy soil, no doubt liable to be flooded at various periods, and elevated
by fresh accession of sediment, as may happen in swamps near the banks
PETRIFIED TRUNKS OF TREES.
29
of a large river in its delta. Trees which delight in marshy ground are
not injured by being buried several feet deep at their base, and other
trees are continually rising up from new soils, several feet above the
level of the original foundation of the morass; and in the banks of the
Mississippi are to be seen sections of a similar deposit.
Conversion into coal is not the only change to which vegetable sub-
stances are subject. The substances of some organic bodies
may be
replaced by mineral matter in the same way that one mineral is re-
placed by another. Petrifaction is a change of this nature, and the
fossil trunks of the Treuil coal mines, as in other localities, have long
had their vegetable matter replaced by sandstone. Göppert, on treating
silicified wood with moderately strong hydrofluoric acid, obtained a
ligneous residue, which for the most part indicated the species of that
wood; also on treating a fossil root, "stigmaria fucoides," fossilized by
carbonate of lime, with diluted hydrochloric acid, the calcareous matter
was dissolved away, and there remained a residue presenting the entire
structure of the root in its natural arrangement and colour.
Bischoff says, "Silicification is a phenomenon so common, that it is
not necessary to assume the existence of any peculiar circumstances
during the petrification of stems of trees in the coal formation, which,
when standing erect, are but little crushed, and very much so when
lying horizontally. This petrifying material is either in an earthy or a
hard state, coarse or fine-grained. In the latter case, the minutest
ligneous fibres can be recognised. In the silicified trees of the coal
formation, which are mostly contained in the sandstone strata, the
periphery consists of a siliceous, and the bark of a thin carbonaceous
mass, while the interior is filled with sandstone. This siliceous mass
is undoubtedly a chemical deposit from the silica dissolved in sea-water,
and the sandstone a mechanical one, like the rock in which the trees are
embedded. The analysis of the former does not show the presence of
more than a mere trace of organic matter. Silica, indeed, appears to
have a great affinity for organic matter, whether in animal or vegetable
fossil remains, and is invariably a constituent of them." Mr. Evan
Hopkins, who has travelled nearly all over the world, states "that there
are immense siliceous and calcareous stumps in their natural growing
position in Chili, Veraquas, in Australia, and Egypt; showing most
distinctly that the trees became silicified, when in the act of growing, by
an excess of silica or lime getting into the soil (like the trees of the
Andaman Islands, which turn the edges of the axes like stone). The
upper part having decayed, the whole forest appears to have been
snapped off by the winds, and nearly at the same time, reminding us
again of the fossil stumps of trees already alluded to.
Although the Treuil coal-mine has been quoted as a good example of
the presence of a fossil forest, we are not confined to foreign countries
for other examples. Hawkshaw describes five fossil trees exposed
in a cutting on the Manchester and Bolton Railway, standing erect
in relation to a bed of coal, and with their roots in a corresponding
So called from the usual triangular shape of the land included between the channels
of the river being similar to the Greek letter A delta.

30
COAL AND COAL MINES.
position. Another tree has subsequently been discovered on the oppo-
site side of the railway, making the entire number six.
Fig. 14. Fossil Trees discovered in making one of the Railway Cuttings between
Manchester and Bolton.
A section of the strata affords the following list of arenaceous and
argillaceous deposits:-
1. Sand intermixed with patches of loam.
2. An intermixture of argillaceous and siliceous shales.
3. Siliceous shale.
4. A vein of coal ten feet thick.
5. Blue and white argillaceous shale, in which the trees are em-
bedded. )
The trees, when dug out, had each a coating of very brittle and
friable coal, which crumbled away as the fossil trunks and roots were
removed from the shale. The largest was about fifteen feet in circum-
ference at its base, seven feet and a half at its top, and eleven feet in
height; the others were from six to seven feet in circumference, and
from two to five feet in height.
At the celebrated Craigleith quarry, near Edinburgh, there used to

FOSSIL TRUNKS OF TREES.
31
be standing one or two enormous fossil trees, of the Araucarian division
of the coniferous family, one of which, exposed in a slanting direction,
was sixty feet long, having a diameter of five feet at the base, and
gradually tapering off to a diameter of seven inches at the top. The
bark was converted, like the specimens discovered on the Bolton and
Manchester line, into a thin coating of the purest and finest coal, the
fossil trunk was deposited in white quartzose sandstone, and the tree
could not have been hollow when embedded, for the interior still pre-
served the woody texture in a perfect state, the petrifying matter being
chiefly carbonate of lime with oxide of iron and alumina.
Fig. 15. Craigleith Quarry.
The geologist, in observing these and other fossil remains, can only
come to the conclusion that fossil trees have originated partly from
submerged forests and partly from floating drift-wood.
The colliers who work the coal, as it may be imagined, do not dignify
these vegetable remains with the names of "fossil trees," but simply
call them "coal-pipes." Of all things in the world, the miner delights
in a tobacco-pipe, but he has an equal detestation of a "coal-pipe,
and the reason of this dislike is soon understood. These great fossil

32
COAL AND COAL MINES.
stone-converted trunks are usually conical-viz., larger at the bottom
than at the top, and they are, as already observed, enclosed with a
thin layer of coal, formed, seemingly, from the conversion of the bark
into that mineral fuel; they have no branches, they stand erect, or
nearly so, and the bond of union or cohesion between the bark and the
surrounding strata is exceedingly slight; when, therefore, this is broken,
either by the vibration of the coal-trucks or rolleys, or by an explosion
of gunpowder in another part of the mine, down falls the ponderous and
stony tree, and of course whatever living thing happens to be beneath
it is either seriously maimed or killed.
Fig. 16. Accident by the falling of a Coal-pipe.
Such accidents sometimes happen at the Durham and Newcastle
pits, and of course if they were laid bare and worked as quarries, all
these fossil stumps would be observed, and danger prevented. It appears
that the coal worked in Siam chiefly outcrops, or comes to the surface;
and when the Siamese ambassadors visited England, one of their chief
inquiries referred to coal-pits, and they could hardly be made to under-
stand that in England men worked in the dark and underground for
the purpose of procuring it.
And now we may ask, how long ago is it supposed that the coal was
deposited? or, in briefer language, what is the age of coal? A precise
PROBABLE AGE OF COAL
33
answer to this question would be impossible, or if attempted, could
result only in vain and useless words. Bischof remarks that "Expe-
rience shows that coal, whether it has been formed by ordinary carbon-
ization of wood or by the action of water, is one of the most inde-
structible of known substances. About ninety years since, pointed
piles were found in the Thames at the place where, according to Tacitus,
the Ancient Britons had driven in a great number of such piles, in
order to hinder the passage of the river by Julius Cæsar and his army.
They were all carbonized to a considerable depth, had preserved their
form perfectly, and were so hard in the interior, that knife-blades could
be made of them. As there is no chemical analysis of these piles, it cannot
be decided whether they were merely carbonized or more or less petrified.
If the vegetable remains under water or buried between rocks were
capable of being completely destroyed, we should not anywhere meet
with coal, the age of which must be calculated by millions instead of
thousands of years.
The talented author of “Our Coal and Coal-fields," in speaking of a
visit to a coal-mine, says: "You are in the catacombs of vegetable
giants, you are treading the streets of more than a buried city of men
and monuments. No storied arches are these, no marble busts are
breathing a stony life here, no illegible descriptions are standing and
lying here, no mouldering bones, no shrivelled mummies, no Egyptian
cats, no dried ibis are here-no spoils of rapine, no relics of royalty, no
fragments of luxurious appliances are here.
Why, all around
you are the relics of innumerable forms of vegetation which flourished
and waved largely and luxuriantly in the warm breezes long before
Egypt was dreamt of, or Nineveh even knew Nimrod, or Athens knew
Theseus or Athene, or Rome knew Romulus, or to begin aright, Adam
saw Eve. Every tree and plant whose ruins are here compressed into
these beds of coal was ante-paradisiacal-was green and was wood
centuries upon centuries before Eden had her first rose, and Eve
her first walk amidst admired and admiring flowers! The age of the
Pyramid of Ghizeh is nothing to this great pyramid of coal. Long,
long before the first stone of that pyramid rose above the sand, these
seams of coal were packed up close, arranged and ready for human
discovery and use. The Pharaohs were great men, but the Pembertons,
the diggers of the deep Monk Wearmouth shaft, are greater." And we
might add the name of Astley, the digger of the deepest coal-pit in the
United Kingdom.
The Pharaohs no doubt in their day were great kings, but they only
built a mountain of stone to cover a molehill of royal dust; whilst the
zealous and enterprising men, the diggers of coal-shafts, working for
the just reward of their labours, have at the same time greatly bene-
fited mankind by the fruit of their great works. Speaking of ancient
mechanical appliances as compared with those of the moderns, who
work with steam generated by burning coal, it has been calculated that
the largest pyramid of Egypt, which is 500 feet high and 700 feet
square at the base, might have been built and all the stone raised by
D

34
COAL AND COAL MINES.
steam-power, with a consumption of about 712 tons of coal, as the great
Watt has demonstrated that fifteen million pounds weight can be lifted
one foot high by the consumption of one bushel of coal.
With this glance at the probable age of coal, we return again to the
geological strata, for the purpose of learning how the coal reposes in
its earthy bed, and whether it is found in horizontal, inclined, curved,
or basin-shaped formations.
Here we come to the simple enunciation of facts, the previous pages
Fig. 17. The Pyramid of Ghizeh.
having been devoted largely to the consideration of the relative merits of
the "Drift" and "Submergence" theories, which account for the origin
of coal; but now it is necessary to deal with facts that are open to
THE COAL BASINS.
35
the critical examination of all, and about which no doubt can possibly
exist.
The coal strata were originally deposited in horizontal or nearly
horizontal positions. But great changes have taken place in the rocks
which compose the outer covering of the globe; and in order to give
instruction in this most important department of geological science,
Mr. T. Sopwith has constructed a series of correct models, presenting
a facsimile of the succession of coal-seams in the Newcastle coal-fields,
&c., &c., and affording a much better notion of geological phenomena
than ordinary plans and sections. These beautiful models are sold in
cases, bound and lettered to resemble books, by Mr. J. Tennant, geolo-
gist, 149, Strand.
By continual observation it has been discovered that all or nearly all
the coal formations are basin-shaped, with long and sloping sides dipping
X 20 MILES WEST DE NEWCASTLE,
RIVER COQUET,
NORTHUMBERLAND.

N
SUNDERLAND.
W
THE SEA.
S
VALLEY OF THE
RIVER TEES.
Fig. 18. The Great Coal Basin in the N.E. Corner of England.
down to a common and profound centre. This hollow or basin-like
form is of so great an extent that an area of a few miles is not sufficient
to exhibit it, just as the spherical or round form of the earth cannot be
discovered by the examination of a few miles of country; hence, in Mr.
Sopwith's No. II. model, representing a small area, the coal strata are
D 2
36
COAL AND COAL MINES.
aptly represented, as regards the limited extent included, by a perfectly
plane surface. To obtain a better notion of the basin-shaped arrange-
ment of coal, the great and principal coal field in the north-east corner
of Great Britain may be taken as an example, where the centre or
bottom of the basin lies about Sunderland.
-
The
Taking a common washhand-basin (Fig. 18) for an example, and at the
same time, stating that it should be rather oval than round, we may write
in the centre, Sunderland, or place a piece of stick in the centre of the
basin, with a label at the top, bearing the word Sunderland; and here, it
may be mentioned, that the deepest coal pits of that region occur.
strata rise like the sides of a basin till they "crop out," or come to
the surface of the earth or nearly so. The northern edge or rim of the
basin is discovered near the Coquet or Northumbrian stream. The
southern edge or rim of the basin is found in the valley of the
river Tees, which divides the counties of Durham and York. The
western rim is about twenty miles west of Newcastle. The eastern edge
of the basin may be covered with a sheet of blue paper, to indicate that
this portion rises useless and nearly unworked at the bottom of the sea,
although occasionally the hardy miners have pushed their galleries even
below the bed of the ocean, to obtain what is termed the ocean coal. Many
years ago, a coal pit was worked at Borrowstownness under the sea.
The seams of coal were found to continue under the bed of the sea in
this place, and the colliers had the courage to work the seam near half-
way over, there being a mote half a mile from the shore, where there
was an entry that went down into the coal pit, under the sea. This was
made into a kind of round key or mote, as they call it, built so as to
keep out the sea, which flowed there twelve feet deep. Here the coals
were laid, and a ship of that draught of water could lay her side to the
mote, and take in the coal. This famous colliery belonged to the Earl
of Kincardine's family. The freshwater which sprung from the bottom
and sides of the coal pit was always drawn out upon the shore by an
engine moved by water that drew it forty fathoms. This coal pit con-
tinued, says the narrator of the above account, to be wrought many
years, to the great profit of the owners and the wonder of all that saw
it. But at last an unexpected high tide drowned the whole at once;
the labourers had not time to escape, but perished in it. At the Howgill
pits, west of Whitehaven, the mine galleries have been driven more
than one thousand yards under the sea, and about six hundred feet
below its bottom. These pits have also been visited by fearful floods
from undermining the sea too closely and deeply.
It is often a matter of surprise with young persons how the learned
geologist or experienced coal engineer can, as it were, look into the
earth, and say whether it contains coal or not; because, if coal were
deposited in even strata all over Great Britain, a deep hole sunk in any
garden would be sufficient to discover it. What kind of spectacles, then,
do they put on for this purpose? Why, none are required; the only
power demanded is the power of observation; and just as we all know and
appreciate a person by the company he keeps, so the geologist or coal
THE COAL BASINS.
37
miner knows where to look for coal by observing the appearance of the
neighbouring rocks or strata.
The next diagram, showing the basin-like appearance of the coal
measures, demonstrates the chief rocks which are the companions and
neighbours of coal, and it represents a section of the coal fields south
of Malmesbury, in the county of Wilts.

9
10
7
8
6
5
4
A
Fig. 19. Section of the Coal Basin S. of Malmesbury.
1, 1. Old Red Sandstone.
2. Mountain Limestone.
3. Millstone Grit.
4, 4. Coal Seams.
5. Pennant, or Coarse Sandstone.
6. New Red Sandstone, or Red Marl.
7,7. Tias.
8, 8. Inferior Oolite.
9. Great Oolite.
10. Cornbrash and Forest Marble.
The apparent inversion occasionally of the coal strata, by which the basin-
shaped deposits appear to be turned upside down, is easily explained by
supposing that two basin-shaped formations might occur side by side; and,
of course, if the edges of two basins are placed together like c c, Fig.
20, and a section taken through, they would represent a convex coal
field, such as that exhibited in Staffordshire, at the Castle Hill, close to
the town of Dudley. Through this hill canals have been cut for working
the immense beds of carboniferous limestone. This seeming inversion
must be regarded as resulting from the approximation of two coal
basins, separated by the basset edges of their mountain-limestone
repository.
The limestone forms the base of the series of the carboniferous
group in the south-west and centre of England, but is more divided in
the north; and here, perhaps, the classification of rocks may not be
altogether undesirable, as it will demonstrate further the position
taken by coal in the assemblage of rocks forming the crust of the earth.
In the first place, the whole number of strata may be divided into two
great classes-viz.:
1. Strata produced by the agency of water, or the aqueous formation.
2. Rocks resulting from the action of fire, or the igneous formation;
38
COAL AND COAL MINES.
which may be arranged as follows:
1. Sedimentary or Fossiliferous Rocks.
2. Metamorphic or Unfossiliferous
3. Volcanic, as Basalt.
4. Plutonic, as Granite.
""
Nos. 4, 3, 2, are called igneous and metamorphic rocks, and contain no
B
B

B
A
A
A


C
C
Fig. 20. Convex Coal-field, Staffordshire. A, A A are Limestone Strata;
B, B, B, B, are Coal Seams.
traces of coal or fossil remains, whilst No. 1 is fossiliferous, and is again
divided into:-
1. The Paleozoic series (most ancient forms of life), or Primary.
2. The Mesozoic series (middle life period), or Secondary.
3. The Cainozoic series (more recent forms of life), or Tertiary.
The Paleozoic or Primary series of the Sedimentary or Fossiliferous
rocks include :-
1. The Cambrian Group.
2. The Silurian
3. The Devonian
4. The Carboniferous
"
5. The Permian
"
SOPWITH'S MODELS.
The Carboniferous Group includes:
1. The Coal Measures
2. Millstone Grit
•
3. Mountain Limestone
4. Limestone Shales .
Average thickness
in feet.
3000 to 12,000
600
500 to 1400
1000
39
Having traced down, as it were, the pedigree and stony relations of coal,
our thoughts may be directed, in the next place, to the mode of probing,
or "boring," the earth for the purpose of obtaining the last convincing
evidence of the existence of coal, before incurring the subsequent ex-
penses of erecting buildings, steam-engines, and machinery for the
purpose of working the coal.
It is sometimes a source of regret to unthinking persons that all our
coal does not outcrop, or basset, and come to the surface, but a moment's
reflection will show that, if this had been the case, we might never have
enjoyed the abundance we now possess of this invaluable fuel; because
it might all have been swept away by those remarkable changes brought
about by the action of water, which have washed away or denuded the crust
of the earth, so as to produce in some places variations in the strata
many miles in depth, and moulded generally that delightful appearance
to the eye of lofty hills and beautiful valleys. To understand what
denudation has done, it is necessary to study Mr. Sopwith's instructive
models, and especially Model I.

Fig. 21. Sopwith Model No. I. (Tennant.)
This model represents a square mass of part of the carboniferous or
mountain-limestone strata, and affords a general idea of the horizontal
40
COAL AND COAL MINES.
الك
deposition of strata. The upper stratum marked 1 represents part of an
argillaceous stratum, or bed of indurated clay, about thirty feet thick;
2 is a siliceous sandstone rock, about ten feet in thickness, called in the
mining districts of Alston Moor, in Cumberland, Pattinson's sill (bed
or stratum); 3 is a calcareous rock called Little Limestone; 4 are sili-
ceous and argillaceous rocks, accompanied by thin seams of coal, mostly
of an inferior quality.
By removing the upper part of the model No. I., the effect of denu-

66
Fig. 22. Hand removing Top of Model No. I.
dation is at once apparent; the various strata are exposed to view.
This," as Mr. Sopwith says, "is one of the first lessons in geology, and
when learnt, the student will find in every mountainous region abundant
examples of vaileys having similar strata, which were once connected,
but have been severed by denudation; and hence such valleys are termed
valleys of denudation. As familiar examples, the valleys of the river
VALLEYS OF DENUDATION.
41
Tyne, Wear, and Tees, in Cumberland, Durham, and Northumberland,
may be mentioned. In them, the cropping out, or basset, of the strata is
very obvious, and affords peculiar facilities for geological research...
To produce such a valley as that represented in the model, it is obvious
that a quantity of rock equal to the whole of the upper portion of the
model must have been washed away; and it thus affords a useful ex-
emplification of the vast amount of denudation which has taken place,
not by gradual operations as ordinary streams deepen their channels, but
by long-continued and powerful currents, of the extent of which we
can judge only by their vast results."
It remains only to be observed, that the portion of the strata repre-
sented by the upper part of the model has, by the process of denudation,
been carried away. This upper portion of the model, on being removed,
may serve, when laid with the surface marked No. 1 upon a table, to

Fig. 23. Sopwith Model. Top of No. I.
exhibit the appearance of strata cropping out or bassetting on a hill,
and presenting exactly the converse of the features exhibited by the
lower portion of the model. The V form of the strata which points
up the valley points down the hill, and the inclined surfaces of the hill
42
COAL AND COAL MINES.
present, in a very satisfactory manner, the great variation of the forms
of the edges of strata which, in the vertical sections at the sides, are
exactly parallel. If all the strata had remained horizontal, and exactly
in the order that they were deposited, like a number of books piled one

TERTIARY STRATA
CRETACEOUS STRATA
OOLITIC ROCKS
2
3
NEW RED SANDSTONE
COAL STRATA
MOUNTAIN LIMESTONE
L
OLD RED
SANDSTONE
5
UPPER SILURIAN
6
LOWER SILURIAN
Fig. 24. The books represent a thickness of about 5 miles, and the hand holding the
stick indicates the great depth of the Coal Strata.
above the other, it is evident that the task of procuring the coal would
have been one of the most laborious and expensive kind; and it is
THE UPHEAVING OF THE STRATA.
43
doubtful whether the coal could ever have been won from such profound
depths.
If it be assumed that the whole series of English stratified rocks,
from the highest formation down to the Silurian rocks inclusive, be
about five miles, the carboniferous series will be represented by about
one-seventh, thus leaving four-sevenths for the thickness of the strata
below, and two-sevenths for the thickness of the upper or superincumbent
strata; and in order to show how wonderfully Providence has ordered
the arrangement of the strata, a number of books may be placed one
above the other, so as to represent about five miles of strata.
Here it will be seen at a glance that, had the beds remained in their

TERTIARY STRATA
GRETACEOUS STRATA
COOLITIC
ROCKS
NEW RED SANDSTONE
COAL
STRATA
MOUNTAIN LIMESTONE
OLD RED
SANDSTONE
UPPER SILURIAN
LOWER SILURIAN
Fig. 25. Same as Fig. 24, only tilted on one side.
original horizontal position, the coal strata could not have been reached,
as the deepest coal mines are not more than about two thousand feet
deep; and, although the thicknesses of the various formations vary in
different parts of the kingdom, still the average thickness would have
formed an impassable barrier and prohibition of coal. But by the up-
heaving forces which have, ages ago, disturbed the crust of the earth,
the lower strata have been brought to the surface, and it is easy, by
placing the hand under the lowest volume, to tilt the pile of books over;
so that, instead of being arranged in the ordinary horizontal position,
they are now inclined at an angle, and the books representing coal and
44
COAL AND COAL MINES.
other older strata are brought to the surface, and can be touched by the
stick.
The task of "boring" must, therefore, always precede the "mining,"
and where this slow but sure plan has not been adopted, the most dis-

Fig. 26. Fossils of the Mountain Limestone and Carboniferous Shale.
astrous loss of property has occurred. The tools for boring are made
of the very best iron and steel-the bore-rods of tough iron, and the
BORING FOR COAL.
45
chisels of well-tempered steel; and the former are united together by
male and female screws. The chisels work into and bore through the
strata, and there is a tool called a "wimble," very much like an auger,
whose cavity is from six to ten inches in length, with an opening on one
side, and a partial overlap in order to receive, hold, and bring to the
surface the bits of broken strata; else the hole would be gradually
choked, and the chisel could not be worked, unless cleared from the
débris as the boring proceeds.
In the Newcastle coal district there are professional master-borers,
who undertake to search for coal, and furnish an accurate register of
the strata perforated. The average price of boring, in England or
Scotland, where no uncommon difficulties occur, is six shillings for
each of the first five fathoms, twice six shillings for each of the second
five fathoms, thrice six shillings for each of the third five fathoms, and
so on.
Whilst searching for coal in any country, its accompanying rocks
ought to be looked for, especially the carboniferous or mountain lime-
stone, known by its fossil remains; also, the outcrop of the millstone
grit and the newer red sandstone, amongst which some rifts of coal
may be discovered, and also fossils presenting the aspect of those in the
cut No. 26.
The mining engineer having surveyed the country, and proved the
existence and general distribution of the coal strata, and also ascertained
that the dip, or incline, of the strata, like the slanting books in Fig. 25,
page 43, is towards the south, commences boring the field at the extreme
northern part of the dip. He might certainly begin his operations at
the south extremity; but then it would be like reading a book back-
wards, as will be understood by reference to the next cut.

H
N
Fig. 27. Mode of "Boring" for Coal.
46
COAL AND COAL MINES.
The first bore is made at No. 1, to the depth of sixty yards, and as it
is proceeding, the peculiarities of the strata, their quality, and thickness
are carefully observed and noted in a journal, whilst specimens of the
rocks passed through are preserved. An ignorant person might suppose
the labour fruitless because the first probing of the "field" has not
touched coal; but there is this satisfaction obtained by commencing at
the extreme northern end-viz., that if coal has not been found, it has,
at all events, not been lost, and the owner of the coal field consequently
discovers, by the boring at No. 2, the exact place where his coal
begins. Now, suppose that the dip of the strata be one yard in ten,
the question is, at what distance from bore No. 1, in a south direc-
tion, will a second bore of sixty yards strike the first stratum D of the
preceding? The rule is, to multiply the depth of the bore by the dip—
that is, 60 by 10-and the product, 600, gives the distance required; for,
by the rule of three, if 1 yard of depression corresponds to 10 in hori
zontal length, 60 yards of depression will correspond to 600 in length.
Hence the bores marked 1, 2, 3, 4, 5, are successively distributed as in
the figure, the spot where the first is let down being regarded as the
point of level to which the summits of all the succeeding bores are re-
ferred. Another bore is therefore made at No. 2, where they strike
at E the stratum of coal they could not touch at No. 1-viz., that
which is just above D, whilst a second seam of coal is also found
at H.
A third bore, at the same distance of 600 yards, is again
made at No. 3, where they touch at H the same seam already dis-
covered at No. 2, and also make the acquaintance of one other
seam, L.
At No. 4 they again strike the L coal seam; and now,
thinking to proceed triumphantly, at No. 5 to touch other seams, they
find, perhaps, that a slip or dislocation of the strata has taken place,
which completely bewilders the master-borer, although he may be an
engineer of considerable experience. A consultation is then held with
other practical men well acquainted with the district, and it is finally
determined whether any further cost shall be incurred by deeper borings.
It should be remembered that the collier does not speak of digging out
the coal as they would of potatoes or other root crops, but proudly
says, "I win the coal;" and we may notice in the next place the
number of troubles and difficulties the engineer has to encounter in
trying to procure the coal; for the same upheaving of the strata which
has done so much good in giving him access to it, has also rendered
that access frequently hard and difficult, because of the breakage of the
continuity of the coal seams by

1. Dykes.
2. Slips, or Faults.
3. Hitches.
Nips, or Wants.
Saddle-backs.
4. Troubles Baulks, &c.
Pot bottoms.
Shaken Coal.
DYKE TROUBLES.
47
A dyke is a wall of rock generally of a nature and age differing from
the strata in which the coal is deposited, and dividing or cutting through
the beds of coal. In some places the dykes have acted as walls to defend
the coal; in others, as levers on a grand scale to upheave it; in others,
as partitions to divide it. They appear to be of an igneous origin, and
to have been produced by volcanic action coming from below and filling
the cracks and fissures in the strata of rocks and coal. The fissure,
according to its contents, is called a dyke," as a "trap-dyke" or a
whin-dyke;" the former being filled with the igneous rock called
trap, the latter with another volcanic rock termed whin or basalt.
CC
The effects of slips and dykes in the coal strata are shown in the
next cuts, and appear more prominently when viewed in a vertical
section than in a ground-plan, where they seem to be merely veins and
lines of demarcation, just like the appearance presented when we look
down upon the surface of a cracked looking-glass.
Fig. 28 is a vertical section of a coal field from dip to rise, showing

a
a
→
α
N
a
C
C
C
RISE.
K
H
F D
Fig. 28. Dyke Troubles.
B
DIP.
three strata of coal, a, b, c. A в represents a dyke at right angles to
the plane of the coal beds. This rectangular wall merely separates the
coal measures, affecting their line of rise; but further to the rise the
oblique dyke CD interrupts the coals a, b, c, and not only disjoins
them, but throws them and their accompanying strata greatly lower
down; yet still, with this depression, the strata retain their parallelism
and general slope. Nearer to the outcrop another dyke, E F, interrupts
the coals a, b, c, not merely breaking the continuity of the planes, but
also throwing them moderately up so as to produce a steeper inclination,
48
COAL AND COAL MINES.
as shown in the figure. It sometimes happens that the coals in the
compartment H, between the dykes C D and E F, may lie nearly horizontal,
and the effect of the dyke EF is then to throw out the coals altogether,
leaving no vestige of them in the compartment K. These dykes, or
walls, are frequently of great value in coal pits, by separating one
division of a coal field from another; thus, in the year 1825, a shaft was
dug at Gosforth, near Newcastle, on the wet side of what is locally
termed the great ninety-fathom dyke, which there intersects the coal
field. The workings were immediately inundated with water, and it

A
B
A
A
B
Fig. 29. A Dyke Trouble, and partial Change of the Coal into Cinders.
was found necessary to abandon them. Another shaft, however, was
sunk on the other side of the dyke, only a few yards from the former,
and in this they descended nearly 200 fathoms, or 1200 feet, without
any impediment from the water. When a coal-pit takes fire, which is
by no means unusual, the wall, or dyke (like the party-wall of a house),
is of the utmost value in arresting and confining the fire to a particular
portion of the coal field so invaded. Sometimes the dyke (as in Fig. 29)
completely displaces the coal, or reduces it to the appearance of half-
burnt cinder. The strata of coal are represented by the dark black
lines, and the main channel of the dyke at B B, showing at its arms A ▲ ▲ A,
near which the black lines are broken and discontinued, the natural
formation of coke or cinder in the earth by the heat probably given
out by the once melted and heated mass of whin, or basalt. This
curious fact appears conclusively to demonstrate that the dyke rocks
must have been in a liquid state, like lava, or they could not have affected
the coal in the manner described. It is right to mention that the advo-
cates of the Neptunian theory insist upon the formation of these so-called
igneous rocks by deposition from solution in water, and they meet the
question of the conversion of coal naturally into cinder by stating that
it has arisen from a spontaneous heat generated by natural changes in
the coal itself.
SLIPS OR FAULTS, AND IIITCHES.
49

NOJ
N° 2
N: 3
a
b
a
a
!
No 4
F. D
B
Fig. 30. Slips, or Faults. The arrows show the direction of the
down-throw and up-throw.
The effect of a slip, or fault, in breaking the continuity of the coar
seams is shown in the above diagram, where we may suppose the coal is

WM
4
3
2
1
Fig. 31. A Hitch,
F
50
COAL AND COAL MINES.
(c
being worked from the seams a, b, c, and is found to be disturbed by an
intersecting slip, A B, which throws all the coals of the compartment
No. 1 much lower, as shown in No. 2; and this is what is termed a
"Down-throw," or Jump-down." Another slip, CD, has produced
similar results in a lesser proportion, when a, b, c are thrown still lower
in No. 3. E F represents a slip in the opposite direction, by which the
coals (a, b, c) are thrown up, and this is called an Up-throw," or
Jump-up, as shown in the compartment No. 4. The appearance
produced by faults is often very deceptive, and has sometimes caused
considerable loss and disappointment, in consequence of inexperienced
persons observing various indications of coal at the surface (all of which
arises from the dislocation of one or more seams of coal), and mistaking
them for separate seams of coal.
""
1
Hitches are small and partial slips, where the dislocation does not
exceed the thickness of the coal seam. The miner's term of “steps"
is well applied to this freak of nature, and is displayed at 1, 2, 3, 4,
Fig. 31.´´As before noticed, when the miner digs into the earth for

A
B
C
F
A
B
C
Fig. 32. A Nip, or Want.
coal, he almost opens for himself a Pandora's box of "troubles," which
are termed nips or wants, saddle-backs, pot bottoms, shaken coal, &c.
A nip occurs where the rocky stratum just above the layer of coal
COAL-PIT
"TROUBLES."
51
invades the thickness of the precious fuel below, and, elbowing it away,
takes the place of the coal; here, instead of digging out coal only,
a considerable portion of the rock has to be removed; hence, where coal
is not, there must be a "want," or nip, and this condition of the strata
is shown at Fig. 32. A B represents the thickness of the rocky stratum
above the coal, c c. The floor is shown at FF, and the stratum A B has
descended into and nipped out the coal at N. A pot bottom is a modi-
fication of the same trouble. Saddle-backs and gaws appear to be the
reverse of nips, as the floor is either irregular or rises into and inter-
feres with the continuity of the coal stratum, again causing profitless
labour in order to level the rock to admit of the rails being laid down
for the rolleys or trucks to roll on. Shaken coal appears to be coal
which has been completely crushed or ground by some extraordinary
pressure and movement of the strata. It very much resembles the rubbish
of an old waste, being a mere shapeless heap of coal dust, which is
often so soft that it may be dug out with a spade.
The fact of coal being charred by the presence of a whin dyke would
seem to prove that the rock forming it had once been in the liquid state;
but the advocates of Neptunian action find no difficulty in urging that the
coal may have become heated like a damp haystack, and thus spontaneously
brought about its own change by internal chemical action, without the
assistance of Pluto and his molten and red-hot rocks. One of the most
interesting examples of this curious change in coal is that of the whin.
dyke in Cooper Colliery, near Blythe, Northumberland, and related in
the "Philosophical Magazine," 1827. "The total length to which this
dyke has been traced is 1577 yards. It increases in breadth from south
to north, being 43 yards wide near the most southern point where it has
been cut through, and 21 yards wide at the most northern spot. It is
formed of two walls of greenstone, each from two to four feet in thick-
ness; and these walls contain between them a brecchia composed of
fragments of shale and whin cemented by calcareous and argillaceous
matter. Carburetted hydrogen and pure water issue from a narrow
fissure in the broadest part of the dyke. The coal of the beds through
which the dyke passes is charred and deteriorated in quality to the
distance of about forty yards on each side."
COAL-MINE MACHINERY.
When coal mining is conducted even in the rudest manner, there
must, of course, be a deep well or pit dug into the earth; and supposing
the miner should meet with the usual occupant of wells-viz. water-it
is evident that provision must be made either to bale it out by tubs, or
some kind of pumping apparatus must be employed for that purpose.
Moreover, the collier must not only be kept dry, but he must have air,
and plenty of it, too, or his health is rapidly undermined, and he
becomes prematurely old and worn out. In other parts of this book
the details of mining will be gradually explained; and, instead of tiring
the youthful reader with the whole at once, they will be spread through
E 2

52
COAL AND COAL MINES.
the various chapters on the metals. The most simple arrangement for
draining and giving air to a mine, and one which is extensively employed
in America, is that of the day level, where the miner commences at the
level of the water at M, Fig. 33, and burrowing into the ground, inter-
sects the coal seams F, E, D. A perpendicular shaft, P, meets this level,
and cuts through the coal at c and B. So far the mine is drained by
Fig. 33. "A Day Level."
the level A, and ventilated by the shaft P; but if they require to go
lower than the level A, a steam engine and pumping apparatus must be
placed at the top of the shaft, P, for the purpose of lifting the water to
the level A, along which it would flow till it fell into the sea at M.
No. 1.
No. 2.
No. 3.
ÖÖ Ö
Fig. 34. Various Methods of dividing a Coal Pit Shaft for Ventilation
and drawing Coals, &c.

THE RUDEST METHOD OF DRAWING COALS, ETC.
53
Such a gallery, or nearly horizontal excavation, is called a day level; it
corresponds with the "adit level" of a mineral mine, and saves expense
in fuel, machinery, and pumps.
The usual method of winning coal is, however, to sink a circular pit
or shaft; and this is subsequently divided by wood work into two com-
partments, one being devoted to the pumps, and the other for ventilation
and drawing the coals; and this is called a double pit, No. 1. Some-
times the shaft is divided into three parts, one of which is occupied
with the pumping gear, and the other two for ventilation and raising
the coals; and this is termed a triple shaft, No. 2. A quadrant shaft
is divided into four compartments, one being occupied with the pumps,
and three for ventilation and coal drawing, No. 3.
Fig. 35. A Coal Rit worked by Women, as described by Mr. Scriven in "Blue Book."
54
COAL AND COAL MINES.
:
The rudest modes of working and winning the coal were disclosed in
the report of the Government Commissioners in 1841; one of whom,
Mr. Surgeon Scriven, gives some graphic pictures indicating the squalid
misery which prevailed in some of the coal districts. In the Yorkshire
coal field of the West Riding he describes the use of the "turn-wheel."
Mr. Scriven very properly says, "It is the least expensive, and certainly
the most dangerous, as you are upon all occasions dependent upon the
man, or it may be the woman, who works it. It is, in fact, nothing
more or less than a common well-winch, with a fly wheel; without trap-
door or stage, conducting rods, or anything else. In getting on or off
the clatch iron or corve, in coming up or going down, you are at the
mercy of the winder." At the very pit, shown at Fig. 35, a certain
Daniel Pellatt was actually drawn over the roller, and killed by falling
from the top to the bottom of the shaft; and it is painful to record
that this man's uncle and grandfather were at work at the winch at
the time, and their attention was diverted by a passing funeral just at
the moment they had drawn their unfortunate relative to the pit's mouth.
In the same picture (Fig. 35) is shown the dangerous and barbarous
method of drawing up a female on the clatch iron by another woman.
"As soon as she arrived at the top, the handle was made fast by a bolt
drawn from the upright post; the woman then grasped her hand, and
by main force brought her to terra firma." The corve, or basket, on
these occasions, is detached from the hooks, to render the load lighter.
The "horse gins" are turned by horses, and work much upon the same
principle as steam engines, with this difference, that the drums are
elevated eight or ten feet above the ground, and revolve horizontally.
(Fig. 36.)
Of the two methods-viz., by the turnwheel or roller and the horse
gin-Mr. Scriven considers the latter (provided the appointments
are in good condition) the least dangerous, as the strength of the
horse, even if disposed to be restive (which would be a most uncommon
circumstance), is seldom sufficient either to draw the basket over the
pulley or break the rope, the horse usually being a wretched, wind-galled,
spavined, blind, and broken-down animal, and driven by a child. The
motion, in coming up or going down the shaft, is of course regulated by the
qualities of the animal, or depends upon the attention of the child that
drives it it is sometimes quick; at others slow, jerking, and disagreeable.
If the shaft happen to be deep, you will probably have the benefit, says
Mr. Scriven, of some f-dozen turns of the rope, by which a swinging
motion is given to the basket or corve; the chances, then, are that you
get a blow from the other ascending, or strike the sides of the shaft,
with the danger of being instantly thrown out.
:
Some few of the "gins" have the excellent contrivance of conducting
rods. These are four iron bars, extending from the frame above the
shaft to the halt-stake at the bottom. They are made to pass through a
ring at each end of the clatch iron; by which means the corve, when
suspended, is kept steady and in its proper place, so that it cannot by
any possibility strike in its descent the ascending corve, or separate the
THE HORSE GIN.
55
loose rocks that form the sides of the unlined shafts; they are also
the medium for the conveyance of signals from below. By striking them
with a piece of iron one or more times, the sound is audibly heard at
the top, and in calm weather at a distance of half a mile.
But, of course, now, at all the best and first-class coal pits, steam
engines and machinery of the most perfect description are employed; and
whenever the traveller journeys in the coal districts, he is pretty well

Fig. 36. The Horse Gin used for drawing Coals, &c.
sure to see the great wooden shaft erected over the mouth of the coal-
pit, with its accompanying engine-house and chimney, the puffing steam,
and beam outside, working up and down, whilst the giant fly-wheel regu-
lates all by its steady motion.
The picture Fig. 38 offers a good example of the better class of
56
COAL AND COAL MINES.
machinery used at coal-pits for raising the men and coals, where the
corves or baskets are abolished, or nearly so, and tubs used instead, which
hold from six to twelve hundredweight each. These are placed on a frame
which works in a slide; and by this means the coals are brought up
much quicker to the pit's mouth.
At many of the Welsh collieries, in consequence of the coal being
"won" in large irregular blocks, it is drawn up in what are termed

Fig. 37. A Welsh "Pyche."
,,pyches. These consist of a bottom floor, or stage, on wheels, and as
the coal is packed on it, open frames are placed one above the other, so
as to retain the coal, and prevent it falling out of its place.
With the discussion of the machinery for raising the coal we come
at once to the mouth of the pit, down which the reader is invited to
travel in imagination, for the purpose of seeing all the wonders to be
noticed in these underground hives of industry.
FACILIS DESCENSUS AVERNI.
57
"DESCENT OF A COAL PIT.”
(AUTHOR'S NARRATIVE.)
Having been invited to deliver a course of lectures at the Philoso-
phical Institute at Newcastle-on-Tyne, my first inquiry would naturally
be directed to coal mines, and asking for introductions to some
of the coal owners, I was much amused on being told "that I had
better finish my course of lectures before going down a coal shaft.” The
descent, however, of a coal shaft furnished with good machinery and

Fig. 38. "The Keepier Mine," near Durham.
draw-ropes is no more dangerous than a railway trip; and after receiving
a proper pass, through the kindness of my late lamented friend, Mr.
Ralph Dixon, I went early one morning to the station, where I was
told to go down the line until I came to another one almost at right
angles, where I should see the full trucks of coal descending and the
empty ones going up. Attending to my instructions, I was soon at the
mouth of the "Keepier Mine;" and as punctuality was the order of
the day, did not wait long before the coal viewer, or overlooker, intro-
58
COAL AND COAL MINES.
duced himself to me by asking in a stentorian voice, "Whether I was
the gentleman who was going down the shaft that morning?" A brief
rejoinder in the affirmative provoked an equally summary reply, given in
gruff and plain-spoken language, and I was ordered to "Step in here".
viz., into a little house, or office, where the coal viewer, again addressing
me, said, "Now, sir, you must take off your clothes." This in the
abstract was rather disagreeable, considering it was winter-time, and
that the ground was covered with snow; but of course he had provided
other garments, and I was soon equipped in the regular miner's attire-
viz., a sort of short rough pilot-coat, flannel continuations, and a very
greasy-looking cap. My guide being a most intelligent person, seemed
to divine that I wanted to see everything, so he politely asked if "I
should not like to see the drawing machinery first ?" And away we
went to the steam-engine house, where we found, as usual, the beam of
the great engine poking its nose out of a sort of upper window, and
making continual bows in connexion with a rod and crank working the
drums on which the ropes are alternately wound and unwound. We
found the engineer inside, seated and looking at his tell-tale, which con-
sists of two pieces of wood attached to a string, and working up and
down in connexion with the machinery in front of a piece of black-
board. The bits of wood are supposed to represent the corves, or baskets,
and by watching their position, the engineer can tell with the greatest
accuracy the exact position of the corves in the coal shaft (Fig. 39); more-
over, a bell rings as the corve approaches the pit's mouth, and again rings
when it reaches the top of the shaft. If the greatest care was not taken
in this respect, the corves, with their live or dead freight, would be drawn
over the pulley, and such accidents as the following might continually
Occur:-
“An accident occurred at one of the pits belonging to Earl Granville,
at Star Green, Hanley Potteries, by which ten men were killed and other
ten severely injured. At half-past two, a cage,' containing fourteen
men, was being drawn up the shaft of the big pit,' while another cage
with six or seven men in it was going down at the same time. As the
ascending cage drew near the surface, the signal-bell in the engine-room
sounded as usual, in order that the engine might be at once stopped.
The engineer was, however, too late in attending to his signal, and
the consequence was that one cage was drawn up beyond its proper
point, while the other went to the bottom of the shaft with a heavy
shock. The ascending cage was drawn up till it reached the wheel over
which the rope attached to it worked, and was being taken round, when
the whole fourteen men, with one exception, were precipitated beneath.
Six fell down the shaft, and were dashed to pieces; three fell on the
pavement at the pit's mouth, and one on the iron pavement, and was
killed on the spot; four who were thrown on the ground received fearful
injuries. The occupants of the descending cage were all more or less
injured by their fall, but none of them were killed."
In this case the poor men were drawn over the pulley, but in the
next case described, the accident occurred from the drum (round which
THE TELL-TALE,
59
the rope is coiled) being improperly connected with the machinery.
It happened near Wolverhampton, and resulted in the instant death of
seven persons. "At a little before six o'clock, the colliers at the Blue
Fly Pit, at the Wednesfield Heath Colliery of Mr. H. B. Whitehouse,
assembled around the pit's mouth to descend to their work, down a shaft
nearly one hundred yards in depth. During the previous night the
engine had been used in drawing water from the pit, and on Saturday

A
B
FATROMS
2
3
4
6
7
8
9.
10.
15
16.
18
Fig. 39. The Tell-tale, which shows the position of the tubs in the shaft.
morning the night engine-tender had left duty, and the engine-tender for
the day had taken the engine in charge. On passing each other, the
engine-tender who was going off duty said to his successor, 'It's all
right. Presuming upon the supposed truthfulness of the statement,
the day engine-tender went confidently into the engine-house, and the
colliers received the customary signal to jump into the skip; four men
and three boys obeyed the signal, the engine was set in motion, and the
skip raised a few inches from the wagon or platform that on such occa-
sions forms the temporary covering to the mouth of the shaft, and the
waggon was drawn away to allow the skip to descend. The engine had
been scarcely reversed before it was found that the drum upon which the
60
COAL AND COAL MINES.
wire-rope that held the skip was coiled had been imperfectly connected
with the engine. In no way held in check, therefore, it began to revolve
with great rapidity, and in an instant the men and boys in the skip were
literally dashed to atoms at the bottom of the shaft.”
It must be evident, from the consideration of these two accidents, that

2
Fig. 40. Aytoun's Patent Safety Cage. 1. Cage descending and chain unbroken.
2. Chain broken, catch disengaged, and the cage stopped by the shoes or slides biting into
and fixing themselves on the guide-rod.
SAFETY CAGES.
61
safety-cages are of the greatest value, even when the rope is carefully
attended to. Neither of the accidents related was owing to any defi-
ciency in the rope or gearing, and yet seventeen lives were sacrificed,
not one of which would have been lost had a safety-cage, with its dis-
engaging catch, been in use. One of the most simple contrivances (Fig.
40) for that purpose is the invention of Mr. R. Aytoun, of No. 3, Fettes-
row, Edinburgh, and is thus described by the inventor:—
"The only novelty in this cage lies in the upper sides, or shoes, and
their appendages. These slides, or shoes, B C, B c, are two in number;
but being placed on opposite sides of the cage, only one of them can be
seen in the drawing. Each of these slides, B C, has a single bolt, or
stud, B, by which it is attached to the cage, and around which it turns;
a long arm, A B, to the extremity of which the winding chain is attached;
a stop, H, which prevents the arm from being pulled above the hori-
zontal line; and a spring, E F, which lowers it when the winding chain
is slack.
"From this description it is easily seen that, in the event of the rope
or gearing giving way, the springs, E F, E F, so tilt the shoes, or slides,
B C, B C, that they immediately seize hold of the guide rods in the
same manner as a boring key in the hands of a miner lays hold of the
boring rods, and with the same tenacity of grip; and although the rope
should come down on the top of the cage, the only effect would be to
cause the shoes to dig deeper into the guide rods, and thus to make the
hold more secure. The means of arresting the cage in its descent being
thus provided, there need be no hesitation in adopting the 'disen-
gaging catch,' whereby, in a case of over-winding, the rope is let go
and the cage remains safely suspended from the guide rods.
"It may be mentioned that the safety apparatus costs little money,
and can be fitted to existing cages. Moreover, when brought into
action, it does not injure the guide rods, and consequently, after an
accident, in which lives and property may have been saved, the winding
may be proceeded with almost immediately.
"To ensure the speedy adoption of this invention, the licence fee for
a single cage, during the existence of the patent right, has been limited
for the present to 17.”
Before the act was passed regulating the labour in coal mines, mere
boys were often employed to attend to the drawing apparatus, and
it will be remembered that the great George Stephenson fulfilled this
kind of duty in the early part of his industrial career. It has been said,
with great truth, that one boy alone at work, is a boy; two boys are
equal to half a boy; and three boys together are equal to no boys,
because they follow their natural instinct and do nothing but play;
hence the Act of Parliament orders that no lad shall be placed at the
very responsible duty of attending to the breaks who is of a less age
than fifteen years. With this digression on the subject of pit machinery
and the risk of over-drawing, we return again to the personal narrative.
'Having examined the engine and drums, ropes, &c., I could not
help saying to my guide, 'Does the rope ever break?' 'Oh yes, sir,
62
COAL AND COAL MINES.
but we are going to give you the new 'un, and now, if you are ready,
we'll go to bank?
CC C
'Going to bank' means going to the pit's mouth; and if the
visitor has never looked down a pit before, it certainly does seem to be
a very dark, yawning, and most dismal orifice or entrance to the riches
of the coal mine. The observer, however, has not time to reflect on
the dangers of the middle passage, for all is bustle and activity at bank,
and everything seems rattling, creaking, and noisy, giving ocular proof
of the most zealous industry. Really, going down coal pits ought to
become very fashionable, considering that H. R. H. the Prince of Wales
and suite visited Houghton Pit, the property of the Earl of Durham,
which they descended, and were conducted through some of the workings
by Mr. Heckels. The Royal party were conveyed from the bottom of
the shaft down the engine plane' into the workings in coal tubs, and
remained in the pit about an hour and a half. The young Prince, who
made frequent and pertinent inquiries of his conductors on different
matters, was shown the mode of working the coal, &c. He evinced no
symptoms of trepidation at the prospect of being let down the yawning
abyss, and in this respect his conduct strikingly contrasted with that of
the late Emperor Nicholas, of whom it is recorded that, after preparing
to descend a coal pit in this neighbourhood, his heart failed him when he
reached the mouth of the shaft, and he declined the perilous journey,
declaring it was like looking down into the infernal regions.
But my companion did not suffer me to waste time, so, once more
asking whether I would go down, and receiving a cheerful 'Yes,' he put
his head over the shaft and emitted the strangest sounds I ever heard.
They seemed to be a mixture of every kind of bellow that one could
possibly listen to, and after waiting a minute or so, I could not help
inquiring why he did not receive an answer. 'Oh! you wait a bit, and
you'll see,' was the rejoinder; and presently a corve full of coal came
to bank, and on it was the desired answer in the shape of a bit of
greasy tow; which telegraphic signal meant that a nice new corve was
coming up for me, but that they did not intend to waste time by sending
it up empty, as some of the colliers would take advantage of the carriage
and come to the surface. Again the bell rang, the engine wound up the
rope with its living freight slower and more carefully; the warning bell
rang as the top of the chain emerged from below, and more chain coming
into view, disclosed a cluster of boys clinging like sailors to the bare
chain above the corve, in which were two or three grave-looking men.
The engine bell rang again just before the rim of the basket touched the
edge of the pit's mouth; and the corve being stopped, the men were dexte-
rously handed out, and the boys liberated from their perilous position; and
although the gravity produced by hard labour was apparent on all coun-
tenances as they came into daylight, it quickly changed into hearty
merriment when they discovered me aping their attire and standing at
the brink, a real live cockney, and ready to descend. I did not, how-
ever, wait long to stand the brunt of their inquiring glances and com-
plimentary speeches; but, obeying the word of command to 'Jump in,' I
COMING TO "BANK.”
63
was soon located in the corve, or basket, and down I went at a speed
which appeared to be very great. I was rushing and tearing through
the air, in a downward direction, at a pace that seemed perfectly

Fig. 41. Men and Boys "coming to Bank."
frightful; indeed it was a good emblem of life, and having taken that
downward course, it was of no use to alter my mind-I could not jump
back again.
38680

64
COAL AND COAL MINES.
"As the corve descended, I could not help looking upwards, when I
discovered that the great yawning orifice had dwindled away apparently
into one of about the diameter of the hole in an ordinary coal-cellar
when the plate is removed; but thinking of a possible visitation
from some of the lumps of coal I had seen at the pit's mouth, I quickly
reversed the direction of my gaze, and found myself tucking my chin
into my waistcoat, to avoid the chance fragments of coal, but instantly
Fig. 42. Descent into a Coal Mine.
reassured, I peered downwards, and then noticed the increasing warmth
of the air. Presently a slight reddish glow of light was apparent, but
before I could perfectly collect my senses, the basket gently touched
the bottom of the shaft, and two or three sturdy fellows rushed at me
with a Now, sir.' I was soon pulled out, another corve full of coal
was tacked on to the rope, and away it went upwards, whilst I was

THE UP-CAST AND DOWN-CAST SHAFTS.
65
conducted through darkness visible to some kind of seat, where I was
gently thrust down, and told to wait a bit till I got my eyes,' for the
sudden change from full daylight to the darkness of the coal pit pro-
duced that want of confidence which is so apparent when visitors at the
Crystal Palace step from broad daylight into the darkened lecture-room
when dissolving views are being displayed.
"The shaft that I descended was called the 'down-cast,' and this re-
presents the beginning of a system of ventilation which ends with
another shaft called the up-cast.' That is to say, fresh air is
always passing down the former, it circulates through the intricate
labyrinth of galleries or excavated tunnels of the coal pit, and, after
having performed its office, escapes at the up-cast shaft. It might be
asked why the air does not sometimes prove refractory and reverse its
path, but that is prevented by a furnace which is kept burning night
and day at the bottom of the coal mine. The chimney conveying away
the heated air from the furnace terminates in the up-cast,' and by
the constant ascent of warm air in the latter, the direction of the venti-
lating currents is established, cold air passing down the 'down-cast,'
and hot and fresh air travelling up the up-cast.""
Fig. 43. A. Furnace. B. The furnace drift. c. The upcast shaft. D. The brattice, or
timber partition separating the up-cast from B, the down-cast, from which the air travels
to the various galleries of the pit, passing to the furnace ▲ B, and so to the up-cast c.
F
66
COAL AND COAL MINES.
As already explained at page 52, sometimes the mine is provided with
one shaft only, which is divided into two, three, or four compartments,
and called a bratticed shaft; but this cannot be so perfect a system as
that which includes separate shafts for the entrance and exit of the
air; moreover, when bratticed shafts are used, the heat of the furnace
which establishes the movement of the air must be greatly reduced, for
fear of setting fire to the woodwork of the brattices.
In the ventilation of mines there are certain rules laid down, the
proper application and modification of which, to meet given circum-
stances and localities, must depend on the judgment and practical expe-
rience of the engineer. These rules are :—
1st. That a current of air through the channels of collieries, at a
rate of five feet per second, is sufficient for almost all purposes.
2nd. That a current exceeding that velocity will be obtained at the
expense of leakage and other evils.
3rd. That, in order to obtain the requisite supply of fresh air, the
channels of a mine ought to be enlarged according to the exigency.
In mines evolving fire-damp it has been found necessary, in practice,
to have as large a ventilation as 300 cubic feet per minute per man;
and if it be assumed that about eighty men and boys are required to
work 100 tons per day, a mine working 200 tons per day would require
48,000 cubic feet per minute, and a mine producing 400 tons per day
would demand a ventilating power of 96,000 cubic feet per minute.
Taking as an example a colliery producing 200 tons per day; if five
feet per second be taken as the standard velocity of the air, it follows
that the intake and return air-channels should have a sectional area of
160 square feet, or about six feet high by twenty-seven feet wide-
dimensions which would be found too expensive, and possibly in many
cases impracticable. This assumes that the air would have to pour in
one undivided channel through the whole of the mine, and in that case
it would, in some large mines, have to travel as much as thirty miles.
But in practice it is not usual, even in the best-conducted mines, to give
to the air-channel a sectional area of more than fifty square feet, and
in many cases, particularly in South Wales, not more than sixteen
square feet.
An idea may be formed of the elaborate nature of mine ventilation by
the examination of the next cut, which represents a ground-plan of a
coal mine supplied with down-cast and up-cast shafts.
This pit contains three furnaces, which communicate with the "up-
cast." The air enters by the down-cast, courses round the goaf, or deserted
portion of the coal mine, and finally escapes at the up-cast.
When the air is supplied to a mine by one entrance only, and is made
to travel by stoppings and doors up and down every part of the works,
it necessarily forms a continuous chain and current of air, which may
be sometimes thirty or more miles in length, and terminates in the up-
cast. This system, which is not a good one, is called "coursing" the
air. It follows, therefore, that, if it were attempted to course the air
in one continuous channel of sixteen square feet, the current would be
LABYRINTHIAN COAL-MINE WORKINGS.
67
16 feet per second, or 50 feet per second with an air-channel of 50
square feet sectional area-velocities which it would be impracticable

FURNACE
FURNACE
DOWNCAST PITÍ.
STABLES
AUPCAST PIT
FURNACE
Fig. 44. Part of the Ground-plan of a Coal Mine.
to keep up through the workings, because the rarefication necessary to
produce such a current would cause the air channels to leak, and the
air to find a shorter course, through the excavated portions of the mine,
to the up-cast shaft. The system of coursing has therefore given way
to that of splitting or dividing the currents of air, which are conveyed
to separate compartments of the best-arranged mines in the North, and in
the same manner as they form distinct workings, so has it at last been
found practicable to ventilate each separately. Therefore, if a panel or
compartment of work of a mine producing 200 tons per day contains
twenty-seven men, the provision to be made in the ventilation for this
section of the colliery, at the rate of 300 cubic feet of air per minute
per man, would be 8100 cubic feet, or one-sixth of 48,600 cubic feet,
per minute; and if this ventilation is kept separate from the remainder
of the colliery, the air will necessarily be much purer, and will have to
travel a proportionably less distance. Moreover, the velocity through
the air-channels will be reduced, in a passage having an area of 50 feet,
from 16 feet per second to 2 feet per second; or, in a passage of
16 feet area, from 50 feet per second to about 8 feet per second. This
latter velocity would still be too high; but by the splitting system a
multiplication of air tubes may be obtained for the intake and return
F 2
68
COAL AND COAL MINES.
air currents of the mine, producing the same result as would be obtained
from one large tube of the aggregate area of the several splittings,
with a diminished distance for the air to travel in the same proportion.
The motive powers in most general use for accelerating the air-
currents of mines are-1st. The furnace. 2nd. The steam jet. 3rd.
The pump, or apparatus such as Struve's mine ventilator.
The use of the furnace has already been described, and in some cases
the average temperature of the air in some of the up-cast shafts of the
mines in the North was from 140° to 160° Fahr. From the minutes of
evidence taken in 1849 before a committee of the House of Lords on
the ventilation of mines, the following extract is selected :-
The Haswell Colliery.
Depth of shaft, 936 feet.
Area of down-cast pit, 110 superficial feet.
Area of up-cast pit, 58 superficial feet.
Average temperature in down-cast pit, 62°.
Average temperature in up-cast pit, 165°.
Velocity of air in up-cast pit, 27th feet per second.
Quantity of air discharged, 94,000 cubic feet per minute.
Consumption of fuel, 4 tons in twenty-four hours.
There are ten splittings of the current of air; the average area of
each is 42 superficial feet, making an aggregate of 420 superficial feet;
the distance travelled in each splitting is 3½ miles.
Estimated power of the up-cast pit, 34,7ths horse-power.
Ventilation of mines by the steam jet originated with Mr. Goldsworthy
Gurney, who proposed its use in 1835; and it consists in the arrange-
ment of boilers and steam-pipes at the bottom of the up-cast, which
are fitted with twenty or more jets, and as the steam escapes up the
shaft, a rush of air takes place from the other parts of the mine towards
them, and promotes a constant flow or current of air through the
galleries. This mode of ventilating mines, though ingenious, is con-
sidered to be expensive to maintain, but is found to be very serviceable
in any case where temporary ventilation is required in a coal pit, and
there happens to be boiler-power to spare. In the "Boy's Playbook of
Science" the steam jet is fully explained and illustrated. The prin-
ciple upon which Goldsworthy Gurney's steam jet acts is very simple,
and depends upon the constant rush of air which takes place towards a
jet of escaping steam. The fact is well illustrated by standing on the
brickwork at the top of a boiler, and asking the engine man to let off
some steam by the safety valve or other aperture; and if a light silk
handkerchief is held near the centre of the escaping cone of steam,
it will be instantly drawn in, and, like a finger-post, will clearly
demonstrate the direction taken by the surrounding air. When steam
is allowed to escape from a Marcet's high-pressure boiler, the air
rushes towards the inverted cone of steam, and if a light copper ball is
placed in the escaping steam, it is held up and supported in spite of its
gravitating power towards the earth, as shown in the next cut.
GURNEY'S STEAM JET.
69

Fig. 45. Escaping Jet of high-pressure Steam, supporting a hollow Copper Ball. The
Arrows show the direction of the air, which rushes to the steam.
Mechanical ventilation may be effected by pumps, screws, fans, pneu-
matic wheels, or modifications of pumps, such as Struve's apparatus
(Fig. 46), used at the Eaglehurst Colliery, near Neath, where the up-cast
shaft is only nine feet area, and yet the ventilation is worked by a five
horse-power engine; and it is calculated that if steam jets were substi-
tuted, four boilers of thirty feet each would be required. Struve's ap-
paratus consists of two aërometers or gasometers, E E, made to balance
each other, and to move vertically in the spaces J J, by means of the guide
rods F F; the spaces JJ are filled with water, forming a packing or stop
to prevent any air passing from the interior of the aerometers to the
chambers above them; the guide rods, F F, are connected by short
chains with the arch heads of the beams, I I, and at the other end of
these beams the motion is received from a small high-pressure steam-
engine, through the crank, G G, and the connecting rods, H H.
The apparatus is connected with the up-cast shaft, a, by a culvert, B,
which communicates both with the interior of the aërometers and the
top chamber, the interior cylinders of masonry, D D, and the inlet valves,
K K. The operation, then, of this machine is precisely that of a pump.
When the pistons ascend they are filled with air, and at the same time
70
COAL AND COAL MINES.
discharge the air out of the top chambers through the outlet valve, L L,
and when they descend they discharge themselves through the outlet
valves, L, and the top chambers are filled; the supply of air in both
cases being drawn from the mine.

LONGITUDINAL SECTION.
› M $
E
TELI
در جوار
PLAN.
B
44
B
R
@
Λ
A. The up-cast pit.
Fig. 46. Struve's Apparatus.
B. A culvert, six feet by ten feet, connecting the up-cast pit with the ventilator.
cc. Two cylinders of masonry, ten feet interior diameter and seventeen feet high.
DD. Two interior cylinders of masonry, ten feet interior diameter, and seven feet six
inches high. The space between the two cylinders, J, is filled with water seven feet deep,
which prevents the air from escaping or being admitted except through the inlet or outlet
valves.
E E. Two aërometers, sixteen feet in diameter, and seven feet high, made to balance each
other, and to move vertically in the water by means of the guide rods in the centre.
F F. Rods working in guides, to give the pistons a steady motion, and to form a con-
nexion by means of short chains with the arch heads of the beams.
G G. Two cranks placed at right angles to each other in a shaft connected with an engine.
и н. Two connecting rods, conveying the motion from the crank to the beams which work
the aërometers.
II. Two arch-headed beams.
K K K K. Four air ports, ten feet by seven feet six inches, fitted with valves for discharg
ing the air into the atmosphere.
LOSS OF LIFE FROM BAD VENTILATION.
71
MM. The framing which supports the working beams, and also the whole weight of the
aërometers.
N N. The beams supporting the guides for the rods to work through.
PP. The embankments formed from the cuttings of the foundations.
B. The framing of a pit for raising coal, showing the cover, s, raised by the wagon, and
the platform of the wagon supplying its place; also the other cover, s, at rest on the other
compartment of the pit, with the rope or chain working through it in order that the
raising of coal may not interfere with the continuous current of air from the mine to the
ventilator; and in order to prevent leakage, the tubes T T T are attached to the top of the
pit, and the platform on which the wagon rests enters one of these tubes before the cover,
8, is lifted,
Z. The engine-house, with a thirteen horse-power engine to work the machine.
One of the learned contributors to the "Edinburgh Review," in an
article on Mortality in Trades and Professions, forcibly illustrates the
importance of good ventilation in mines, and states, "his (the miner's)
supply of oxygen is small; for in all probability the air supplied to him
has to circulate many miles through the mine, and to pass over the ex-
crementitious deposits of man and horse, and the decaying woodwork of
the mine, ere it finally reaches him, in enfeebled streams, in his solitary
working cell. Long deprivation of solar light, again, tends to im-
poverish his blood, to blanch him, in short, like vegetable products
similarly deprived of the light of day. It is through their lungs, how-
ever, that the health of the miner is principally attacked. The air of
a coal mine (such as it is) holds a vast amount of coal dust in mecha-
nical suspension, and this, as a matter of course, is constantly passing
into the lungs of the miner. The proof of this
The proof of this is the so-called 'black
spit' of the collier, which, on being subjected to the microscope, is found
to consist of mucus filled with finely-divided particles of coal. The per-
manent inhalation of such an atmosphere results in what is termed the
black lung. The breathing apparatus of the collier becomes clogged,
in short, with coal dust, and after death it has the appearance of being
dipped in ink. A writer who has lately investigated this singular
pathological condition, thus gives his experience of two post-mortem ex-
aminations: In each case the black treacly fluid obtained by thus
cutting the various portions of the lung (more especially the posterior
and inferior portions of the lower lobes), and by splitting up, the bron-
chial tubes are evaporated to dryness, and the residuum being broken
up and subjected to a red heat in a porcelain tube retort, behaved pre-
cisely as coal under similar circumstances, i.e., it evolved a smoke-like
gaseous product, which on being slightly condensed, deposited hydro-
sulphide of ammonium and coal tar, and being then purified burnt in
all respects like the well-known compounds of the two carbides of
hydrogen (common gas).'
Although a chemist would object to the mode of testing for coal in
this last-quoted experiment, as the animal matter was not first separated
from the impalpable coal dust, and the products from both were there-
fore eliminated together during the destructive distillation, still there
can be no doubt respecting the carbonaceous nature of this black treacly
fluid.
"Dr. Gregory, of Edinburgh, many years since, by destructive analysis,
72
COAL AND COAL MINES.
came to the same conclusion respecting the carbonaceous nature of this
deposit. The presence of this foreign body in the lungs leads to the
whole train of pulmonary diseases. Asthma, bronchitis, and pneumonia
are but too frequent, and we are consequently not surprised to hear
that the aggregate amount of sickness experienced by this class for the
period of life from twenty to sixty, is ninety-five weeks, or sixty-seven
per cent. more than the general average.
"It is estimated that the worst coal mines can be ventilated thoroughly
at a cost of one penny per man per day, and that in well constructed
furnaces the consumption of one ton of coals per day at the bottom of
an up-cast shaft will enable each collier to cut one ton of coals more
per day with the same amount of exertion. Such being the case, there
can be no excuse for asphyxiating the miners wholesale. Those pro-
prietors of mines who are only open to these breeches-pocket appeals,
should know that it is their interest in a pecuniary sense to ventilate
well, inasmuch as the preservative effect of pure air upon the wood
brattices, which form so expensive an item in mining, effects a saving of
eighty per cent."
With this digression on the important subject of ventilating mines,
we return again to the descent of a coal mine, and resume the narrative
from page 65, where we left off to explain the various methods employed
to give the miner air. "After taking my seat on the bench for a few
minutes, I soon recovered the use of my senses, and the first object of
interest that I noticed was a sort of inner den or cave, from which
there issued the usual odour of a stable; so I said to my guide, 'What!
horses here ?' 'Oh, yes, sir; nice little "gallusses,"* aint they?' And
at that moment a sleek little nag, well groomed and cared for, came into
view; and I soon found that the animal was detached for my special
service, and that I was to go into the workings without the trouble of
wading through the muddy channels on foot, in fact, to ride in front of
a rolley or truck conveying empty baskets or corves to be refilled with coals.
Before taking my seat, I was presented with a lump of clay and a
miner's candle; and perhaps careful people may be desirous of learning
what sort of candle it could be? Was it a six, or a twelve, or a long
ten? No, it was one of those remarkable lilliputian candles from
twenty to thirty to the pound; and the reason of this exemplary
economy will be understood, when it is stated that the miners provide
their own candles; the coal owners do not furnish them. The quantity
of oil and candles consumed in the mines of the United Kingdom
cannot be less than half a million of money in value; and it is only
surprising that in safe mines-viz., in such as are free from fire damp,
that coal gas is not more extensively employed. Some time ago, Mr.
Wright read a most interesting paper before the Society of Civil
Engineers, and quoted an instance where the cost of lighting a mine had
been reduced from about 8007. to 4007. per annum by the use of coal
* Gallusses, a corruption of the word Galloway, being a hardy little horse first bred at
Galloway, in Scotland.

THE TRAPPER BOY.
73
gas; and as it burns without producing soot or those disagreeable em-
pyreumatic odours arising from the imperfect combustion of tallow and
oil, and at the same time affords a better light, it will no doubt be
gradually substituted for them. Having taken my seat in front of the
corves on the rolley, away we went for something like three quarters of
a mile into the workings, for this mine is somewhat ancient, and has
been worked since the time of Queen Elizabeth. Either I did not hold
my candle properly, or we moved too quickly, for it soon guttered away,
and deposited an ample greasy hæmorrhage in my hand, and at last,
receiving a drop of water from the roof, it sputtered angrily, and burnt
dimmer than before. I cannot say that at any time we came to a full
stop, but occasionally we perpetrated a sort of comma, or moderation of
our pace, in order to allow the little trapper boy time to open his door.
Fig. 47. Trapper Boy.
These doors are used for the purpose of maintaining the continuity of
the ventilating currents of air, because if the latter was allowed to make
its way at random through the workings, some parts would have a
perfect hurricane of wind, whilst in others the air would stagnate and
suffocate the persons engaged in the mine.
"The 'trapper' boy's employment is his first dreary apprenticeship in
the coal mine; and if he can bear that, he is not likely to be timid
afterwards. There they sit for hours in the dark, they must not stir
from their posts, for fear of being lost; indeed, there was a case of this
kind in a Welsh pit: a little trapper boy strayed away from his door,

74
COAL AND COAL MINES.
and was lost for three days; the lad stated afterwards, that he fre-
quently made his way to the back of the place where the colliers were
at work, and even heard the sound of their picks, he screamed and
roared, but it was of no use, they could not hear him, and it was only
by accident he providentially struck upon the right path, and made his
way in a wretched condition to the bottom of the coal-pit shaft. The
pitmen will tell you, that after the first few hours, the constant question
of the trapper boy to those who pass him is, 'Will it soon be time to
cry Kenna mon?" alluding to a cry which is shouted down the shaft
when it is time to leave off work. If personal friends go through his
doorway, he will beg a light with a coaxing Gie us a loo, mon,' for
his mother only furnishes him with two of the peculiar dips already
alluded to: viz., one to light him to his door, and another to light him
to the pit's mouth after his shift of work' is over; but, as before
stated, this must be regarded as the apprenticeship to coal-pit work,
and if the boy can get through this, he can do almost anything after-
wards.
Fig. 48. The Crane Hoister.

THE PUTTERS.
75
"After proceeding a considerable distance on a tram-way, the little
horse at last pulled up, and I found myself in a part of the pit which
had been widened out so as to afford room for a crane, where I made
the acquaintance of the crane hoister, whose duty it is to lift the cases
of coal from the rolleys pushed by lads to those which are pulled by
the horses. This lad is supposed to be better informed than his hard-
working companions, as he has sufficient learning to enable him to chalk
down upon a slate the number of corves that pass him. And here
perhaps it may be asked-How do they distinguish between the idle and
the industrious? or, rather, we ought to say, between the weak and the
strong? And how can they tell who fills each corve with coal? The
answer is very simple: each coal hewer attaches his own wooden label
to the basket he fills; this is noted at the crane, and also at the pit's
mouth, so that no man is likely to be defrauded of the just reward of
his labour; moreover, the quality of the coal sent to bank' is strictly
looked after, and the men are fined if they fill out their baskets with any
rubbish or débris of the rocks they pass through.
"Having now dismounted from the truck, I proceeded on foot, in
Indian file, after my guide, occasionally standing on one side to allow the
rolleys pushed by half-naked lads to pass by; and here it may be said
that the severe work of the mine commences. I have seen many kinds
of labour, but never before witnessed such straining, pushing, and
general activity; indeed, I could not help asking my companion whether
they were doing extra work that day. No, sir, it's their regular work;'
and such work as would put to shame any other that could possibly be
thought of; and it is agreeable to know that now, in many of the first-
Fig. 49. The Putters at work.
76
COAL AND COAL MINES.
class coal pits they are substituting Shetland ponies, whose hardy
roughness is of course better suited to the fearful wear and tear than
the poor human muscle, bone, and flesh of which our bodies are com-
posed."
These lads are called putters, and have even amongst themselves
grades of rank; for instance, the leader is called the "headsman," the
second in dignity the "half marrow," and the third lad, who is generally
attached to the rolley in front with a chain or rope, is called "the foal.
It is curious to observe how nature illustrates science; these lads lose
from six to eight pounds' weight during the eight hours' spell in the
mine, and with their violent perspiration and increased respiration, lose
a large amount of fatty matter, hence it is not surprising to hear that
they generally prefer the fattest pork and bacon; and the lads especially
enjoy now and then a great treat, called a “singing hinney," composed of
flour and butter, or some other greasy material; this is cooked on a
gridiron, and whilst being dressed the heat evaporates any watery par-
ticles therein contained with a sort of hissing or singing noise. It may
be interesting at this point to speak of the temperature of mines in
general, as instead of being cold they are usually warm, and the heat
increases with the depth of the coal pit. Professor Graham says, in his
Elements of Chemistry"-"There can be no doubt of the existence in
this globe of ours of a central heat. At a depth under the surface of
the earth, not in general exceeding twenty feet, the thermometer is
perfectly stationary, not being affected by the change of the seasons;
but at greater depths the temperature progressively rises.'
M. Cordier, to whom we are indebted for a most profound investiga-
tion of this interesting subject, considers the two conclusions to be esta-
blished by all the observations on temperature which have been made
at considerable depths:-1st. That below the stratum where the annual
variations of the solar heat cease to be sensible, a notable increase of
temperature takes place as we descend into the interior of the earth.
2nd. That a certain irregularity must be admitted in the distribution of
the subterranean heat, which occasions the progressive increase of tem-
perature to vary at different places.
Fifteen yards has been provisionally assumed as the average depth
which corresponds to an increase of 1° Fahrenheit. This is about 116°
for each mile. Admitting this rate of increase, we have at a depth of
30 miles below the surface a temperature of 3500°, which would melt
cast iron, and which is amply sufficient to melt the lavas, basalts, and
other rocks, which have actually been erupted from below in a fluid
state. But this central heat has long ceased to affect the surface of the
earth. Fourier demonstrates, from the laws of conduction, that although
the crust of the globe were of cast iron, heat would require myriads of
years to be transmitted to the surface from a depth of one hundred and
fifty miles. But the crust of the globe is actually composed of materials
greatly inferior to cast iron in conducting power.
The temperature of the surface of the globe now depends upon the
amount of heat which it receives from the sun, compared with the heat
THE CENTRAL HEAT.
77
radiated away from its surface into free space. There is reason to
believe that no material change has occurred in the quantity of heat
received from the sun during the historical epoch. The radiation from
the surface of the earth has its limit in the temperature of the planetary
space in which it moves, which Fourier deduces from calculation to
lie between -58° and -76° Fahr., and which Schomberg, from a
calculation on totally different principles, estimates at -5896; a close
coincidence. This low temperature appears to be attained in the long
absence of the sun during a polar winter, as Captain Parry found the
thermometer to fall so low as -55° or -56° at Melville Island; and
Captain Back has recorded a temperature, observed on the North
American continent, so low as -70°. The temperature of the famous
Monkwearmouth colliery, one of the deepest and perhaps worst venti-
lated mines in the United Kingdom (having only one bratticed shaft),
stands at about 78° to 80° Fahr.; and in the workings, where the tem-
perature is increased by the heat from the bodies of the men and their
lamps, the thermometer ranges from 85° to 90° Fahr. The tempera-
ture of the water issuing from the Artesian well of Grenoble, 600 yards
in depth, is 82° Fahr., being an increase of one degree for every 59 feet
in depth.
The statement of the existence of an internal heat in the earth is curi-
ously corroborated by the natural tar wells of Rangoon in Birmah. This
empire contains more than 500 wells in a small district called Rainanghong.
The soil there consists of a sandy clay, covering a thick bed of slate clay
saturated with naphtha, under which is coal, as if a kind of natural dis-
tillation had proceeded from the coal below; and since petroleum con-
tains paraffin, a product of the dry distillation of vegetable substances,
it was inferred that this substance originated from the action of sub-
terranean heat upon coal. According to our knowledge of the increase
of temperature towards the interior of the earth, coal beds at a
depth of about 8000 feet would possess a temperature of 212°; and
we may suppose that this petroleum, or mineral tar, was distilled from
such beds and condensed at higher points. But in this case the tem-
perature of the soil impregnated by it in places where it occurs in large
quantities, as in Asia, must long since have been raised to a nearly
equal degree, which is, according to the observations made by Abiel, by
no means the case.
On the western shores of the Caspian, in the country round Baku,
upon the peninsula of Abscheran, a tract has been long known under
the name of the "Field of Fire," which continually emits inflammable
gas, while springs of naphtha and petroleum occur in the same vicinity.
Abiel found the medium temperature of the soil of Abscheran to be 59°
Fah., that of the naphtha 62°.5 to 66°, and that of the gas springs
68.5; the gas therefore can only come from moderate depths. Upon
the Schagdag, not far from the village of Kinalurghi, 7834 feet above
the Caspian Sea, are found considerable exhalations of carburetted
hydrogen gas (the Eternal Fire of the Schagdag), which stream directly
out of clefts in sandstone alternating with slate. This burning gas is
78
COAL AND COAL MINES.
never extinguished by atmospheric changes, and these, with other
natural and eternal sources of fire originated, no doubt, the ancient
faith of the Fire Worshippers.
The Rangoon tar is brought to this country in iron tanks, and some
very important and practical results have been worked out from it at
Price's Candle Factory, in the preparation of paraffin candles and Bel-
montine oil. There are three qualities of oil obtained: one like alcohol,
is ignitable by wick only; the second is brown in colour, and useful for
machinery and spindles, with the advantage of not corroding metals.
The third is a detergent fluid, and will remove grease spots, without
staining even delicate silks.
At Colebrookdale, in Shropshire, there is a naphtha spring rising
from a coal seam. It likewise occurs at Amiano, in Parma, at Modena
and Piacenza, near the Tegernsee, in Bavaria. Mineral tar occurs in
Persia, France, and several other places.
Numerous experiments have confirmed the theory of Cardieu and
others, that the temperature increases one degree of heat for about
every fifteen yards, and the following results may be quoted as good
examples, because they are obtained independent of the air, which must
partake of the temperature of the bodies of the colliers and their
burning lamps or candles.
Whitehaven.-Spring water at surface .
Ditto at 480 feet
•
Ratio from surface, one degree for 44 feet.
Workington.-Spring at surface
Ditto at 504 feet
Fahrenheit.
49°
60
48
60
49
Ditto at a depth of 900 feet
70
Ratio from surface, one degree for 43 feet.
Jarrow Colliery (Tyne).-Surface assumed.
49.5
Ratio from surface, one degree for 42 feet.
Percy Main Colliery (Tyne).—Mean temperature at surface
Water at 882 feet deep
Ratio from surface, one degree for 48 feet.
Killingworth Colliery (Tyne).-Surface assumed.
Water at 1200 feet depth
Ratio from surface, one degree for 46 feet.
68
48
74
In trudging through the galleries of a coal pit, the visitor becomes
hot and feverish with excitement, until a copious perspiration breaks
out and relieves the sufferer; he then feels as I did, able to finish his
work and proceed to the actual spot where the men are digging or
hewing out the coal.
The cut offers some idea of the numerous tiring and almost painful
postures the miners are obliged to assume; kneeling, stooping, and
lying down, and great activity is required to change the position rapidly,
in order to get at the coal; and when the limbs have become stiffened
THE COAL HEWERS.
79
with age and exposure to the vicissitudes of mining life, the daily earn-
ings are much reduced, and whilst some men may earn four, others will

Fig. 50. Various Positions assumed by the Hewers in digging at the Coal
only get three shillings per diem. There is, however, some consolation
left to the men-viz., in the fact that they have now arrived (so far as
the hard work is concerned) at the very tiptop of the profession.
The writer (already alluded to) on Mortality in Trades and Pro-
fessions, says, "Of these artisans, exposed to irritating dust, pro-
bably miners take the second place after the miserable Sheffield dry
80
COAL AND COAL MINES.
grinders. If we investigate the condition of these men, we are imme-
diately struck with the lamentable conditions under which they labour,
and astonished at the endurance and patience with which they submit
to toil, to which that of the well-fed, well-housed felon is pleasant pastime.
There are at present upwards of 300,000 human beings acting the part
of gnomes (those imaginary beings who were supposed to inhabit the
interior of the earth), for the good of the community at large, entering
day by day into the bowels of the earth, and emerging in the evening.
Of human life they see as little as the train of black ants we watch
emerging from their holes in the ground. Yet the miner is the industrial
Atlas of England. Were he to cease to labour, this busy hive of men
would speedily be hushed, and the giant limbs of machinery, which now
do the drudgery of the world, become as still as the enchanted garden
of the fairy tale ere the advent of the prince. Without the coal and
the iron, the copper and the tin, they toilfully evolve from vast depths,
England would be but a third-rate power. In many pits in the West
of England the seams of coal are not more than twenty or twenty-five
inches thick; and inasmuch as the object of the worker is to remove
the coal with as little as possible of the surrounding soil, he often
drives his working to a considerable distance through an aperture not
more than, and often not so much as, two feet high. If our adult reader
will condescend to squat himself on the floor à la Turque, say under
the dining-table, for instance, and then picture to himself the incon-
venience of picking with an axe the under side of the prandial ma-
hogany for twelve hours, he will obtain some slight idea of the muscular
knot into which the poor collier has to tie himself for the whole term
of his working life, having to use violent exertion throughout. Can it
be wondered at that, under such circumstances, the Apollo-like form of
man becomes permanently twisted and bent, like the gnarled root of an
oak that has been doubled up in the fissure of some rock? If we look
at a collier, we see instantly that his back is curved, his legs bowed,
and the extensor muscles of his calves withered through long disease.
He has knotted himself so long that the erect position of his race
becomes a punishment to him. It is credibly related that a number of
colliers having been sentenced to imprisonment in Wakefield jail, with
hard labour, the only complaint they made was, that they were obliged,
whilst at work, to keep the ordinary posture of rational creatures.”
Working as these men do, in constant fear of death, it is no wonder
that they are somewhat superstitious, and firmly believe in bad spirits
and omens. Should a collier meet a woman whilst going to his work at
any very early hour in the morning, such as two or three o'clock, he would
consider that circumstance as a bad omen, and would turn back from
his work; or if any white animal, such as a rabbit or a cat, happen to
cross his path, he would not risk his life that day in the coal pit.
Superstition is not confined only to the poor miners; one of the most
learned of men never considered his affairs would go quite smoothly
during the day unless he trod upon a particular stone in Bolt-court.
With respect to the labour of the collier, some idea may be formed
THE PITMAN.
81
of its severity by obtaining the opinion of other hard-working men. It
is stated that during the temporary strike of the "coal whippers" (the
men who discharge the cargoes of the colliers or coal brigs into barges
on the Thames), a benevolent gentleman thought he could employ some
of the fine stalwart men who were thrown out of work, by sending
them down to the coal pits in the North, and, by way of trial, three
strong, able-bodied men were selected and forwarded, carriage paid, to
their destination. They did not, however, imitate the example of the
great Cæsar-they went, they saw, but did not conquer; indeed it
would appear they were disgusted at the notion of any one supposing
that human beings-"Christians"-could be asked to do such work, and
vanished from the scene without condescending to offer any explanation
of their conduct to the kind gentleman who imagined he had discovered
a new market for their labour; hence "coal whippers" thought their
work quite easy as compared with that of the "coal hewers." In cer-
tain coal districts with small workings, as in some parts of Stafford-
shire, the mining population displays great and lamentable ignorance,
with all the poverty and squalor of crowded dwellings; but in the best-
regulated and larger coal-pit districts of the North, the collier is a sen-
sible and self-respecting man, keeping a good cottage over his head and
aking care of his wife and children, the latter being clean and flaxen-
naired; whilst the "gude wife" shows her appreciation of her lord's care
by cramming the cot with the largest and most Brobdignagian furniture
she can procure; and it is said that there is quite a competition in a
first-class rookery," or assemblage of miners' cottages, amongst the
matrons for the possession of the best household gods. A clever ob-
server and writer in a Northern paper says:—
"The pitman is not the mere wretch that haunts a refined imagina-
tion. The influence of his dark environments, and of a life under the
unique conditions of a deep Northumbrian mine, displays itself less in
his physical than it does in his mental malformation. The village
attached to a colliery, or a 'colliers' row,' as it is called, may not
have an attractive exterior-it seldom has-but it reverses the de-
scription of a whited sepulchre: it is dingy enough without, but enter
the humble mansion, and you find it the very picture of cleanliness and
comfort. You will find an eight-day clock; you will find a shining
table turned up against the wall; you will find a four-post bedstead
and half-a-dozen excellent chairs; and, above all, you will find in the
mistress of the house a love of external purity almost amounting to a
passion. At the same time you will discover a certain barrenness of
imagination in the arrangements, a tendency to assume stereotypic forms,
a monotony and uniformity in the mode of fitting out those little man-
sions, which is not an agreeable, because not a healthy feature.
observe, as a general rule, no indication whatever of any individual
fancies. Not a soul in the place seems to have a taste of his own. The
interior of one pitman's cottage is as like another as the hexagonal cells
of a honeycomb. There is in each the same four-post bedstead, the
same shiny table against the wall, the same eight-day clock, and the
G
You
82
COAL AND COAL MINES.
same six stout chairs. With an obvious determination to gratify a
sense of general comfort, there is no more effort apparently to meet in-
dividual tastes than if the human family had been cast in the same
unvarying mould of propensity, desire, and aptitude. This, we repeat,
is not a wholesome characteristic, but it is surely far enough removed
from the misery which has been depicted. Cleanliness, according to
John Wesley, is to be ranked as next to godliness. There is not much
godliness in the pit; but no artisan's wife alive is more careful of her
husband's appearance, and of the appearance of the house he has to
come to, than she who waits with tub and soap the approach of her
grimy goodman. A story is told of a pitman in one of the neighbouring
villages, who wanted to lay up a sovereign unknown to his wife, in anti-
cipation of a coming cock-fight; but where to store it was the rub. At
length it occurred to him that by putting it between one of the bed-
posts and the floor, so that the post would rest upon it, he might put
detection at defiance. The day of the fight arrived, and John, sending
his wife out on a message, proceeded to raise the bedpost and draw out
the hidden coin. Out it came shining and safe, but he could scarcely believe
his eyes it seemed to be only a half-sovereign. My conscience,' he
said, 'how it has shrunk!' The fact was, Jean had been accustomed
to whisk out the dust from recesses which no broom would enter, by
means of a goose's wing, and her attention was one day rewarded by
whisking a sovereign from under the bedpost, and, deeming she had a
right to the half of it, for whatever purpose it had been deposited there,
she took the precaution to substitute the smaller coin, which John in-
vested in the chances of the cock-fight. Unfortunately, we fear, the
cock-fight, or rather the habit of mind which seeks its gratification in
such a display, is equally characteristic of the pitman. He is not un-
comfortable, but he is sometimes very wicked. England may be said to
have two populations, a terrene and a subterranean; and the annals of
crime show that the begrimed myriads burrowing beneath our feet,
among the crystallized remains of a forest older than the ichthyosaurus,
live and move in a moral darkness of which the darkness of the pit is
but the symbol. For there is no denying that, in the scale of criminality,
a mining population does stand unenviably high; and they who owe
their wealth to the toils and the drudgery and the danger-defying labours
of the human gnome will be the first to acknowledge and lament, and the
first also, we hope, in their efforts to abate, the deplorable thing we
mention. Northumberland ranks among the most criminal counties in
England, and in this rank it stands actually as high as fifth,-more
crime being committed in Middlesex, Lancashire, Surrey, and Warwick
alone.
"It was laid down at a recent meeting of the Social Science Association
that the amount of crime is in a direct ratio to the density of a popula-
tion; which, indeed, is only saying that most crime will occur where the
criminal has most chances of escape, and that where the greatest number
of persons of every character is assembled, there will also be the greatest
number of bad characters. But Northumberland is an exception to the
CONDITION OF THE PITMAN.
83
rule. Northumberland is less dense in population than other counties
less criminal. Several counties more compactly inhabited produce a
lighter calendar; and our place in the criminal scale may be safely set
down, we imagine, to the fact of our possessing a large and growing
underground population. But when the subject is fairly considered,
the rule that criminality is in direct proportion to the density of the
population in which it occurs, is as much in harmony with the circum-
stances of a mining as with the circumstances of a metropolitan popula
tion. To a large extent the two classes come under the same category,
for that temptation to crime which arises from the facility of escape,
operates no less on the collier when he finds himself in the open air,
than on the London thief in the neighbourhood of one of his favourite
alleys. The one believes he has only to plunge into the pit, the other
believes that he has only to plunge into the slum, in order to defy
pursuit. To this influence must in part be attributed the excess of
criminality predicated of our mining population. But the density of
a mining population increases that influence by increasing the chances
of escape still farther; and the population of Northumberland is
rapidly increasing in density. The population of England and Wales,
taken over all, increased during the decade ending 1851 at the rate of
thirteen per cent.; but in the mineral counties of England, which are
the most criminal counties, and in Glamorganshire, in Wales, which
has the same physical and moral characteristics, the increase amounted
to nineteen per cent. upon the preceding enumeration. Of that in-
crease Northumberland has more than had its share. Here, then, in
the condition of a mining population, we have almost every circum-
stance meeting favourable to the genesis of crime. There is density
of population, facility of escape, gross and prevailing ignorance; but
there is not that lowness of physical comfort which superficial observers
imagine. Wages are good, work is abundant, and masters have had
too many fearful warnings of the readiness of their men to strike, to be
very unreasonable or exacting. Though that element of criminality,
however, so far as we have been able to observe directly, is in a great
measure wanting, especially in the North of England, its absence is more
than made up for by another important circumstance characteristic of
the life of a pitman, for a tendency to excess is greatly exaggerated by
that recklessness of consequences incident to all peculiarly precarious
occupations. It is never more difficult to keep the crew of a vessel
back from the spirit-stores than when the vessel is on fire and the dare-
devils know that the flames will soon be at the powder-casks. Much of
the recklessness which seems almost constitutional in a seaman is un-
doubtedly due to the continual possibility of the occurrence of some such
accident, and to the continual occurrence of accidents in which lives are
extensively lost. The same influence is always at work in a mine. Let
us eat and drink, for to-morrow some one will be lighting his pipe at a
Davy, and we shall all be blown to atoms. Let us eat and drink, for
to-morrow the roof of the pit will be falling in, and we shall all be
crushed to a jelly. Let us eat and drink, for to-morrow the rope bɲ
G 2

84
COAL AND COAL MINES.
which we descend will be breaking, and we shall be gathered up in
bloody fragments at the bottom. The exposure of a pitman to this
continual but uncertain danger naturally results in an uncalculating and
reckless temper-a recklessness which does not display itself merely in
a course of abandonment to pleasure, but in doing at once and with all
his might whatever his hand findeth to do, whether it may happen to be
a violation of the law or not."
If it be expedient, in these days of advancement in all civilized arts, to
discuss the question of the amelioration of the condition of the "pitman,"
there could be no question about the absolute necessity of a searching in-
quiry into that of the poor "pit-women," who were formerly induced and
expected to work in those dreary regions. The debased condition of these
poor creatures can be well appreciated when we read the evidence respect-
ing the "Yorkshire Coal-fields of the West Riding.' "Girls from five
to eighteen perform all the work of boys. There is no distinction whatever
Fig. 51. Susan Pitchforth.-"I would rather set cards, or do anything else, than work in
pit. I have one sintoning of fourteen: she works with me."

WOMEN FORMERLY EMPLOYED IN COAL MINES.
85
in their coming up the shaft or going down. In the mode of hurrying
or thrusting, in the weights of the corves, or in the distances they are
hurried-in wages or dress. Indeed, it is impossible to distinguish,
either in the darkness of the gates (galleries of mines) in which they
labour, or in the cabins before the broad light of day, an atom of dif-
ference between one sex and the other. It is not my intention to
indulge in any display of fine feelings in directing your attention to
their employment in these dens of darkness, but I should be a traitor
to my countrywomen if I did not by every means in my power attempt
to excite in you, and through you, a desire to rescue them from a state
of moral degradation and suffering to which they are doomed, and that,
too, it may be affirmed, much against their inclination."
It would be tedious to quote all the illustrations of the evil effects of
employing women in coal pits; their cruel degradation must be evident
from the next cut. Thus, with respect to the poor creature crawling
on hands and knees, with that rude coal-box without wheels attached to
her waist with a chain, the commissioner stated that her sister was doing
Fig. 52. Women at Work.
86
COAL AND COAL MINES.
the same kind of work in a coal pit, and that she was positively
beautiful. (Fig. 52.)
Again, the poor old woman whose duty it was to carry the creel, or
basket, on her head from the bottom to the top of the coal shaft,
up a rickety ladder or rude staircase, when interrogated, replied
with great bitterness, and said "she wished the back of the first woman
had been broken who first undertook to carry the coals, for it was not
work for women folk;" and it is pleasing to know that very soon after
these statements were published, such were the efforts made in both
Houses of Parliament, and especially by Lord Ashley, now the Earl of
Shaftesbury, that an act was passed in the reign of our beloved Queen
Victoria, whom God long preserve, which abolished for ever the labour
of women in coal mines, and said that no children for the future should
work in coal pits who were of a less age than ten years. Before the act
was passed, it was stated that poor little things from three to five to
seven years were actually employed to pick up coal in the pits, for the
sake of the miserable pittance their tender strength could earn. It
is indeed satisfactory to know that this blot on the industrial records of
Great Britain is now wiped out.
EXCAVATION OF THE COAL.
It is not usual to remove the whole of a seam of coal, as the miners
burrow into the earth, but to divide and intersect it by what are
variously termed "partings," "backs," "faces," "cutters," and "ends."
Besides the chief partings at the roof and floor of the coal seam, there

D
C
Fig. 53. Method of excavating Coal.
IB
POST AND STALL SYSTEM.
87
are intermediate lines of parting, or places of cleavage, parallel to the
chief partings.
The letters A, B, C, D, E, F, G (Fig. 53), represent a mass of coal, being
a portion of a regular coal seam, and they are the chief partings at the
roof and flooring respectively; Q, Q, Q, the intermediate "partings," or
planes of cleavage; z z, z z, z z, the "backs;
backs;" P P, P P, the cutters.
It thus appears that a bed of coal, according to the number of these
planes of cleavage, may be broken or subdivided into solid cubical
blocks. The most common method of working the coal is by "post
and stall," or "pillars and rooms;" by which plan a certain quantity
of the coal is left in the pit to support the roof, and these pillars are
subsequently removed, when the whole coal field has been worked out
in this form.

O
Fig. 54. "Post and Stall System."
tr
CC
After driving the main levels in opposite directions upon the engine.
shaft, narrow mines, or galleries, called "bays," are driven out of the
main levels at regular intervals, in the direction of the rise, at right
angles to the backs. Cross-roads," or cut-thro's," are then driven
at right angles to them at every five or six yards-thus, in Fig. 54, L L
represents the main level; 0, 0, 0, 0, 0, 0, the pillars of coal supporting
the roof; P P P, the gallery; Q, Q, the cut-thro's. The galleries are
88
COAL AND COAL MINES.
not usually at right angles to the main levels, but sometimes meet
them in an acute angle, as in the ground-plan.
Mr. Kennedy has compared the post and stall method to a subterra-
nean town, with its numberless streets and alleys. The blocks or pillars
of coal left standing correspond with the houses, whilst the galleries, or
portions removed, are analogous to the streets.
After the coal has been removed in the manner described, the colliers
then return, as it were, upon their path, and proceed to remove the sup-
porting pillars; but by this time, probably, what is called "
a creep,

Fig 55. A Creep, and Cause of Thurst.
has taken place in certain parts of the mine, and the floor gra-
dually rises between the supporting pillars, by the superincumbent
pressure of the earth, and fills the space from which the coal was
excavated (Fig. 55).
1 shows the state of creep when ready to commence the working of
the crept pillars; 2, the first operation, or partial working of crept
pillars; 3, the second operation, or complete working of crept pillars,
where the roof is supported by wooden props and juds; and as they are
very economical in a coal pit, and will not leave a stick behind if they
can help it, they gradually draw away the props, and then, perhaps in a
few hours, days, weeks, or months, down falls the earth in great ava-
lanches, filling up the hollow space in a partial and irregular manner,
and forming at 4 what is termed "the goaf," being those portions of a
mine which have been worked out or deserted; and it is (as will be pre-
sently noticed) from these portions of the mine that the "fire-damp
ssues which does so much damage to life and property.
>>
When a coal field has been completely worked out, and the props re-
EFFECTS OF UNDERGROUND TUNNELLING.
89
moved, a gradual subsidence of the earth takes place, which the miners
call a
"thurst" after a creep.

ཀ་
A-
B
Fig. 56. A Thurst after a District of Crept Pillars is completely wrought off.
The effect of the sinking of the earth is sometimes very apparent on
the cottages and houses of those who live above the exhausted coal
fields; and as the earth becomes slightly concave, they all partake of the
angle, and the sinking of the door posts and window frames, with cracks
in the walls, show clearly the result of the underground tunnelling.
90
COAL AND COAL MINES.
Bills are filed in Chancery for injunctions to restrain persons from work-
ing mines under houses, and also from working any mines under land
adjacent thereto, in such manner as to cause damage or injury to the
foundations of the houses. As to the people who live in these tumble-
down dwellings, they, "like the unfortunate eels," become quite used to
the effects of these artificial earthquakes, and will not condescend to
turn out of their houses until they are just on the point of falling and
crushing them in the ruins.
There are three modifications of the "post and stall" system prac-

GOAF
Fig. 57. Ground-plan of the Shropshire Method of "Long Work." The face where
the men are at work is drawn in perspective to assist the explanation.
THE LONG WALL SYSTEM.
91
tised with seams of coal of every thickness. With the coals which are
only some six or seven feet thick, "the long work wall," or Shropshire
method, is pursued (Fig. 57). By this system no pillars are left, but all the
coal is taken out progressively as the workings advance; the roof is
supported by underposts near the face at which all the men work in a
line. As the workings are carried forward, the posts are withdrawr,
and the superincumbent strata are allowed to fall in at the heels of the
miners.
In the cut Fig. 57, a represents the engine-pit and down-cast; B, the
up-cast or cross-pit. The shaded portions represent the coal seam. The
white part marked "Goaf" up to the irregular line, represents that
portion of the seam which has been exhausted, and of which the roof
has fallen in; the small circles represent the underposts which sup-
port the roof at the faces where the men are at work, and the arrows
represent the course of the air from the down-cast to the up-cast.
In the Bristol coal district colliers work seams of coal as low as
nine inches thick. In the latter case, at least sixteen or eighteen
inches must be excavated to allow the men to work in the recumbent
position, and on their sides, the other seven or nine inches being shale
or fireclay. The collier holes, or works under the coal, with his elbow
resting on the inside of his knee.
On the other hand, there is the great Dudley seam of coal, which is
thirty feet thick (Fig. 57); and here, of course, the men work in greater
comfort. It is usual for the pitmen to contract to remove so many cubic
yards, and they commence by first digging or holing away the base of the
cube, which is then propped up with timber; in the next place, they
cut away the sides and top, leaving only the back, which is finally
charged with gunpowder, and connected with a slow match. On a
proper signal being given, all the men in its vicinity remove to safe
quarters, the mine explodes, and down falls the great cubical mass of
coal, which is soon shovelled off into corves or tubs, and conveyed to
the pit's mouth.
ور
During an imaginary walk through the coal pit I have said nothing, as
yet, respecting the drainage of the subterranean works. Considerable
practice and skill are required to select the right portion of the coal
field to which all the water will fall, so that, as the workings proceed,
they may not be incommoded. Hence, the shaft is not only completed
to the coal, but is continued further downwards, as a well, or "sump,'
to provide "standage," or reservoir room, for the collection of the water.
In some of the Shropshire pits I have seen large tubs used with a valve
at the bottom, which are let down alternately with the empty "pyches"
or frame boxes for the coals. The valve is forced open as the tub
enters the "sump," and the water flows in; the tub is now lifted to
the pit's mouth, when the pressure of the water shuts the valve, which
is subsequently opened by a lever at the top of the shaft, and the water
passes away by a surface drain. It shows the utter want of caution in
the pitmen to see half-a-dozen of them come up, perhaps 300 yards,
only standing upon the edge of one of the large tubs full of water, and
holding on by the chain.

92
COAL AND COAL MINES.
Fig. 58. The working of the great Dudley thirty-feet Seam of Coal.
In some of the mines it is found to be advantageous to carry out
"driftings," or spaces dug out in the stone or coal to contain a week's
drainage, or more; so that, in case of any sudden increase of water,
they may have timely notice, and thus prevent accidents. Before the
general employment of the steam engine, both coal and water were
raised by horses; afterwards water-wheels were erected; and, in 1708,
windmills were built for the same purpose. A majority of the mines
yield large quantities of water; some have been known to yield as much
as 2000, or even 3000 gallons per minute from very deep springs.
Force-pumps, worked by powerful steam engines, are kept constantly
FIRE-DAMP.
93
at work, both by night and by day; but as this part of the subject
belongs especially to the details of the mining engineer, we shall not
pursue it further here, except to state that the arrangement and working
of the pumps is a part of the regular duty of a coal pit which demands
constant care and attention, and is one of the heaviest expenses the
Coal owner has to contend against. Sometimes the unequal contest is
given up, and a new shaft abandoned on account of the enormous cost
of keeping it free from water. On the way back to the pit's mouth
the water may be noticed ever flowing towards the "sump." And
having once more arrived at the shaft we started from, I take my
place in the empty corve, and again return to terra firma. A coal pit,
no doubt, is a very interesting place to visit once or twice in the course
of one's life; but the satisfaction is something akin to travelling in fast
trains-we are glad to make use of them, but more delighted to step
out of the carriage.
now,
cr
FIRE-DAMP.
In our journey through the coal pit we have alluded to some of the
dangers, but said little or nothing about that most fiery trial to which
the poor collier is subjected in many of the Newcastle mines, called
fire-damp." However good the general system of ventilation may be
in a mine, unforeseen accidents will happen at any time. A sudden
invasion of this combustible gas, disengaged by the fall of a mass of
rubbish in the goaf, or of a quantity of coal in the workings, may meet
the collier, who is working, perhaps imprudently, with a naked candle,
and an explosion follows, which crowds the pit's mouth with a wailing
multitude of newly-made widows and orphans. The Edinburgh
Review" says that upwards of 1500 lives are annually lost, and not
less than 10,000 accidents in the same period testify to the dangerous
nature of the miner's occupation. It is humiliating to know that
England is yet far behind Continental nations in her methods of pre-
venting these dreadful catastrophes. Mr. Mackworth, in his lecture at
the Society of Arts, stated that the mortality from accidents was in the
coal mines of
Prussia
CC
1.89 killed per 1000 per annum.
Belgium.
England.
Staffordshire
2.8
""
"
4.5
>>
>>
7.3
>>
Fire-damp is not a definite chemical compound, but a mixture of
various gases, and explodes only when mixed with a certain proportion
of air; by itself the gas is simply combustible, like ordinary coal gas,
and burns without detonation. The combustible gases from coal
pits have been frequently analysed, and the following analyses by
Bischoff and Graham afford a correct statement of the constitution of
the gas which issues from a coal-blaze or blower :-
94
COAL AND COAL MINES.
Bischoff.
Th. Graham.
I.
II.
III.
IV.
V.
Carburetted hydrogen (83-03 ... 91-36... 79-10... 942 ... 82·5
•
1·98 ... 6·32 ... 16·11 ...
Olefiant gas
Oxygen gas
Nitrogen gas
14.94
2.32
...
...
1.3
...
1.0
4.79 4.5... 16.5
100.00 ... 100·00...100.00...100·00...100·00
The chief constituent of all pit gases is carburetted hydrogen, some-
times mixed with small quantities of olefiant gas and carbonic-acid gas.
Nitrogen seems to be invariably present. It cannot be derived, says
Bischoff, from atmospheric air in those instances in which it comes
with force from fissures, but is no doubt a product of the decomposition
of organic substances, most probably of the coal itself. The similarity
of the pit gases to marsh gas is much in favour of the view that such
is the origin of the nitrogen.
Light carburetted hydrogen is synonymous with marsh gas, fire-damp,
and consists of C₂, H₁.
•
C₂, Carbon
H₁, Hydrogen
12
4
16
The equivalent or combining proportion is 16, and the specific gravity
559.6, air being 1000.
This dangerous gas is liable to issue at any moment during the work
of the coal-hewer, who may suddenly strike his pick into a cavity
where the fire-damp has been pent up for ages. It rushes out with
great violence, and is then termed "a blower." If the ventilation is
good, and the men are working with safety lamps, little or no danger
may be apprehended; but if naked candles are used, and the current of
air in the mine is sluggish, the mixture of fire-damp and air accumulates
to a remarkable extent; and the train being fired at some point, the
whole explodes with fearful violence, blowing everything before it.
Those who have visited pits after one of these calamities, state that the
wood work is broken and splintered like twigs in the hand of a child,
and living beings are projected bodily through frameworks of wood just
as if they were hard, solid, and inanimate substances. The destruction
of life, as it were in a moment, is frightful, one or two hundred lives
being sometimes lost on these occasions. Science, however, steps in
here, and clearly indicates that such calamities may be prevented-first,
by good ventilation; second, by the use of safety lamps.
Having already alluded to the important subject of ventilation, which
bears the same relation to the safe and successful working of a coal pit
as drainage does in agriculture, some space may now be devoted to that
valuable instrument called the safety lamp, with a brief digest of those
THE DAVY LAMP.
95
admirable experiments made by Sir Humphry Davy which led to its
construction.
An opinion prevails amongst the "Newcastle folks" that Geordie
Stephenson invented the safety lamp before Davy produced his, because
the former was seen on one occasion observing "that the flame of the
candle did not pass through the small apertures of the latticed fender, and
gathering from this fact the rude idea of a safety lamp ;" and further,
that he actually constructed and tried his lamp at Killingworth Col-
liery before any other person had tested one under similar circum-
stances. In 1818 this opinion of the services of George Stephenson
took a tangible and demonstrative form, in the shape of a silver tankard
containing one thousand guineas, which were presented to him in the
Assembly Rooms at Newcastle, as the "discoverer of the safety lamp."
In May, 1818, Sir H. Davy collected and published, in a connected
form, all the papers that he had written on this subject; and it must
be evident from the originality of his experiments that he required no
borrowed genius, that the ideas he worked out were his own, and that
Stephenson and Davy must have been independent labourers in the same
field, probably arriving at similar results by different means, just as
Daguerre and Talbot, in the art of photography, reached the same goal
by entirely distinct paths.
Sir H. Davy says, "When I first turned my attention particularly to
the subject [accidents from fire-damp], which was in August, 1815, in
consequence of a letter from the Rev. Dr. Gray, there appeared very
little hope of finding an efficacious remedy. The resources of modern
chemical science had been fully applied in ventilation, in the improved
plans of Mr. Buddle; the comparative lightness of the fire-damp was
well understood, every precaution was taken to preserve the communi-
cations open; and the currents of air were promoted or occasioned,
not only by furnaces, but likewise by air pumps and steam apparatus.
Sir James Lowther had observed early in the last century that the fire-
damp in its usual form was not inflammable by sparks from flint or steel;
and a person in his employment had invented a mill for giving light by the
collision of flint and steel (Fig. 59). This was the only instrument except
common candles employed in the dangerous parts of the British collieries.
Yet instances of explosion have been known from the steel mill, and it
required manual labour for its use. In Flanders, amadou, or fungus
tinder, had been occasionally employed in dangerous parts of the mine;
but the light yielded by this substance was much too feeble to be used
for working the mines, and only enabled the miners to find their way
for particular occasions. M. de Humboldt, the justly celebrated philo-
sophical traveller, in 1796 conceived and executed the plan of a lamp*
for giving light in mines where a common candle would not burn or
produce explosion; but it was founded on the principle of entire insu-
lation from the air, and could burn only for a short time till the air
contained within it was exhausted.
* Journal des Mines, tom, viii. p. 839.
96
COAL AND COAL MINES.
"A lamp upon a plan similar as to insulation was contrived by Dr.
Clanny in 1813; but he supplied his light with air from the mine
through water by bellows, and it went out in explosive atmospheres,

Fig. 59. The Steel Mill for giving Light in Coal Pits. The mill is attached to the waist
of a boy, who holds the flint in one hand against the steel wheel, which is rapidly rotated
by the other hand.
and, to be employed, required to be worked by hand or by machinery;
and neither M. de Humboldt's lamps or Dr. Clanny's had, for obvious
reasons, I believe, ever been used in coal mining.
"The great object-one rather to be ardently desired than confidently
expected was to find a light which, at the same time that it enabled
the miner to work with security in explosive atmospheres, should like-
wise consume the fire-damp.
66
Having learnt from Mr. Buddle the degree of light required for the
common operation of the workmen, I made several experiments with
the hope of obtaining such a light without active inflammation. I tried
Kunckel's, Canton's, and Baldwin's phosphorus, and likewise the elec-
trical light, in close vessels; but without success."
DAVY'S ORIGINAL EXPERIMENTS.
97
Kunckel's phosphorus is the element obtained from phosphoric acid,
and used extensively in the manufacture of lucifer-matches. When ex-
posed to air, phosphorus gives out light in consequence of the slow
oxidation of its surface.
Canton's phosphorus is made by calcining oyster-shells in the open
fire for half an hour; after which, the whitest and largest pieces are
selected, mixed with about one-third their weight of flowers of sulphur,
pressed into a crucible with a closely-luted cover, and heated red hot
for an hour. When the crucible has become quite cold, its contents
are turned out, and the whitest pieces selected for use.
Baldwin's phosphorus is prepared by melting nitrate of lime in a
crucible or ladle for about ten minutes; it is then poured into an iron
pot, or mould, previously heated, and has the property, like Canton's
phosphorus, of absorbing light when exposed to the sun, and emitting it
when taken into a darkened room.
The electric light is that obtained when two pieces of hard carbon,
in connexion with a powerful voltaic battery, are brought in contact
with each other.
Sir Humphry Davy further adds: "I had a lamp made with two
valves, which closed in atmospheres contaminated with fire-damp by the
increased heat of the flame produced by the combustion of the gas; but
this lamp could not be used in an explosive atmosphere. It will be un-
necessary to dwell upon preliminary and unsuccessful attempts, and I
shall proceed to describe the origin and progress of those investigations
which led me to the discovery of the principles by which explosion and
flame may be arrested and regulated; and by means of which the miner
is not only able to subdue and control, but likewise to render useful his
most dangerous enemy.
"I first began with a minute chemical examination of the substance
with which I had to contend. The analysis of various specimens of
fire-damp showed me that the pure inflammable part of it was light car-
buretted hydrogen, as Dr. Henry had before stated, hydrogen, or pure
inflammable air combined with charcoal or carbon. I made numerous
experiments on the circumstances under which it explodes, and the
degree of its inflammability. I found that it required to be mixed with
very large quantities of atmospheric air to produce explosion; even when
mixed with three or nearly four times its bulk of air it burnt quietly in
the atmosphere, and extinguished a taper. When mixed with between
five and six times its volume of air, it exploded feebly; it exploded with
most energy when mixed with seven or eight times its volume of air;
and mixtures of fire-damp and air retained their explosive power when
the proportions were one of gas to fourteen of air. When the air was
in large quantity, the flame of a taper was merely enlarged in the mix-
ture; an effect which was still perceived in thirty parts of air to one of
gas.
رو
These original experiments of Sir H. Davy may be illustrated in a
simple manner by filling a bladder with coal-gas and passing some gas
from it into a graduated bottle filled with water. When half-filled with
H
98
COAL AND COAL MINES.
gas, the bottle may be stoppered and removed from the pneumatic trough,
and on taking out the stopper again, the water left in the bottle falls out
and atmospheric air takes its place. After the gases have been well
mixed by shaking the bottle, a lighted taper may be applied, when it
will be found that the mixture burns with a feeble blue flame, but does
not explode. On the other hand, if the bottle is graduated into eight
parts, and one part only is filled with coal gas, whilst the remaining
seven parts of water are displaced by air, then, on mixing as before, and
applying the lighted taper, the mixture burns rapidly, with a rushing or
roaring noise, indicating what would happen on a large scale, supposing
the fire-damp and air were mixed in a similar manner.

A
B
Fig. 60. A. Passing coal gas into a narrow-mouthed bottle in the pneumatic trough.
B. Bottle half full of coal gas, and the remaining half water; the latter is falling out, and
the air is taking its place.
Sir H. Davy found the fire-damp much less combustible than other
inflammable gases. It was not exploded or fired by red-hot charcoal or
red-hot iron: it required iron to be white-hot and itself in brilliant com-
bustion for its inflammation. The heat produced by it in combustion
was likewise much less than that of most other inflammable gases, and
hence, in its explosion, there was much less comparative expansion. On
mixing one part of carbonic acid, or fixed air, with seven parts of an
explosive mixture of fire-damp, or one part of azote, or nitrogen, with
six parts; their powers of exploding were destroyed. In exploding a
mixture in a glass tube of one-fourth of an inch in diameter and a foot
long, more than a second was required before the flame reached from
DAVY'S FIRST LAMP.
99
one end to the other; and Davy found that in tubes of one-seventh of
an inch in diameter, explosive mixtures could not be fired when they
were opened in the atmosphere; and that metallic tubes prevented ex-
plosion better than glass tubes. Sir H. Davy then had a lamp con-
structed with narrow tubes above and below, and he says: "In trying
my first tube-lamp in an explosive mixture, I found that it was safe;
but unless the tubes were very short and numerous, the flame could not
be well supported; and in trying tubes of the diameter of one-seventh
or one-eighth of an inch, I determined that they were safe only to small
quantities of explosive mixture, and when of a given length; and that
tubes even of a much smaller diameter communicated explosion from a
close vessel. Hence I took a new method of ascertaining the safety of
my apertures and of trying different forms of apertures. I had a vessel
furnished with wires by which the electrical spark could be taken in an
explosive mixture, and which was larger in capacity than a safe lamp
or lantern was required to be. I placed my flame sieves-i.e., my systems
of apertures-between this jar and a bladder containing, likewise, an ex-
plosive mixture, and I judged the apertures to be safe only when they
stopped explosion acting upon them in this concentrated way." Sir
H. Davy at last arrived at the conclusion that a metallic tissue, how-
ever thin and fine, of which the apertures filled more space than the
cooling surface, so as to be permeable to air and light, offered a perfect bar-
rier to explosion, from the flame being divided between, and
the heat communicated to, an immense number of cooling
surfaces; and he at length arrived at one evidently the most
simple-viz., that of surrounding the light entirely by wire
gauze, and making the same tissue feed the flame with air
and emit light. We can imagine Sir H. Davy's satisfaction
when, as he says: "In plunging a light surrounded by a
cylinder of fine wire gauze into an explosive mixture, I
saw the whole cylinder become quietly and gradually filled
with flame. The upper part of it soon appeared red-hot,
yet no explosion was produced."
The first safety-lamp was constructed of fine wire gauze
shaped in the form of a cylinder and about ten inches long,
two inches in diameter, and closed at one end with wire
gauze. Soft clay was then moulded and pressed around
the middle of a lighted candle, and this was covered with
the wire-gauze cylinder, so that the lower edge of the
gauze was firmly pressed and embedded in the lump of
clay. If such a lamp is held before a pipe from which
coal gas is escaping, the latter burns inside the cylinder of
wire gauze, but does not communicate with the exterior
gas. In Sir H. Davy's later experiments, he employed
coal gas because it takes fire at a lower temperature than
fire-damp; and therefore, if his lamps stood the higher test
of coal-gas mixtures, they were sure to answer in fire-damp Therst Safe
mixtures. Indeed, he says, "I placed my lighted lamps

Fig. 61.
Lamp.
Um
H 2
100
COAL AND COAL MINES.
MU
in a large glass receiver through which there was a current of atmo-
spherical air, and by means of a gasometer filled with coal gas, I made
the current of air which passed into the lamp more or less explosive, and
caused it to change rapidly or slowly at pleasure, so as to produce all
Fig. 62. Sir H. Davy's Lamp, as used in
Coal Mines.
possible varieties of inflammable
and explosive mixtures; and I
found that iron wire gauze, com-
posed of wires from one-fortieth
to one-sixtieth of an inch in
diameter, and containing twenty-
eight wires or seven hundred
and eighty-four apertures to the
inch, was safe under all circum-
stances in atmospheres of this
kind; and I consequently adopted
this material in guarding lamps
for the coal mines, when in Jan.
1816, they were immediately
adopted and have long been in
general use."


It deserves to be remarked,
that when Sir H. Davy was
pressed to secure his safety-
lamp by patent rights, he re-
jected the idea of making money
by his philosophical discoveries,
saying, "I have enough for all
my views and purposes; more
wealth might be troublesome, and
distract my attention from those
pursuits in which I delight.
More wealth would not increase
my fame or my happiness."
Since Davy's time a great many improvements have been suggested
in the construction of the safety-lamp, but none adopted, chiefly because
the "butty" system is opposed to any change of candles or lamps that
involves an outlay of money. "The butty men" have always made
an enormous per-centage out of the miners; and whenever any good
novelty, such as Simons' patent safety-lamp, is proposed, they play upon
the weakness of the poor ignorant men, and encourage them to oppose
everything likely to be introduced into the mine that will interfere with
their profits. The order of succession in which a great number of
mines are worked is as follows :-First, the owner, who lets the mine to
second persons called the contractors. These gentlemen never enter the
mine, and know nothing about the management or the miners. The
contractor makes the best bargain he can with the third person, the
butty, who is usually a man only one grade above the ordinary pitmen;
frequently a man from their own rank. He perfectly understands the
SIMONS' SAFETY DETECTOR LAMP.
101
prejudices and weaknesses of the poor fellows who spend nearly half
their lives in the coal pit and the other in bed, and so manages that a
very small sum out of every twenty shillings' worth of labour shall reach
them in the shape of current coin of the realm.
The principal danger arises from the men removing the wire gauze
from their lamps, and, in order to prevent this folly, Mr. Simons has in-
vented a self-extinguishing lamp, in which an extinguisher falls over the
light directly a man attempts to unscrew the wire gauze.
This lamp
has already been described and illustrated in the "Boy's Playbook of
Science," and therefore need not be repeated here; it is, in fact, the
original "safety-lamp" of Sir Humphry Davy, with Simons' self-acting
extinguisher.
In the next cut the different forms of lamps and candles (all provided
with spikes to fix into the walls of the galleries in which the men work)
are fully depicted and explained, being those supplied for the purpose
by Mr. Simons, of 84, Dale-end, Birmingham.

A
Iruini
C
B
Fig. 63. A. Miners' Safety Lamp for fixing or hanging in any part of the mine where
danger from any sudden or unexpected appearance of gas is to be apprehended, but where
the work is progressing, and a good, steady, and safe light is required. This lamp will give
the light of six candles, which can be directed to any desired point. It is under lock and
key; a piece of tale is suspended from the top of the gauze to prevent the flame from
burning through it, and also in front of the glass to protect it from the heat. The lamp
will burn from six to eight hours without any interference after being trimmed and put
into the miner's hands for use.
B. A Miner's Perfect Safety Lamp with all the different advantages of the above; but, in
addition, a ring at the top, prevented from getting heated by a non-conductor, and also a
handle to the side, so that it can either be carried about or hung up as may be needed.
This is under lock and key, and will have a self-acting extinguisher, so that the lamp cannot
possibly be opened without extinguishing the light.
c. A Cornish Miner's Skull-cap Lamp, for carrying on the head, or on the front of the
wheelbarrow, when going up the adit, and reversing when returning. It is easily removed
to fix wherever it is required.

102
COAL AND COAL MINES.
The consideration of the Davy lamp naturally involves a few remarks
upon the accidents with fire-damp which it is intended to prevent; and,
perhaps, one of the most fearful on record is that which took place at
the Lundhill colliery on the 19th of February, 1857, when about one
hundred and eighty men and boys lost their lives. The pit is in the
neighbourhood of Barnsley, and near the Wombwell station of the
South Yorkshire Railway, and the accident is thus graphically described
by the author of "An Hour in a Coal Mine," in "Chambers' Journal":-
"The men work in three gangs eight hours each, and, of the two
hundred who formed the gang which commenced work at six o'clock in
Fig. 64. The Ventilating Shaft on Fire at the Lundhill Colliery.
THE LUNDHILL COLLIERY EXPLOSION.
103
the morning of the day in question, not one-fourth came out of the pit
alive. About noon, those above ground felt the earth tremble, and
heard a smothered sound, which told only too certainly of disaster.
Wives left their simple preparations for dinner, children their play,
and all hastened to the pit's mouth. There they soon learned that an
explosion of such extreme violence had taken place in the mine as to tear
away the drawing ropes and destroy the apparatus for ascending and
descending the shaft. About two o'clock volumes of smoke issued from
the chimney of the ventilating shaft, and an hour later a magnificent, but
terrible, body of flame shot up therefrom, indicating the ignition of in-
flammable gases below, and giving heart-sickness to all the lookers-on,
who thought the while of husbands and fathers, sons and brothers, down
in the fiery bowels of the earth. It was a fearful crisis. The mine was
evidently on fire, and no one could go down to aid the sufferers. The
managers felt the full extent of their responsibility. If they closed
up all the shafts and pit's mouths, it might seem like consigning the
poor miners to certain destruction, and yet if they did not do so, there
was danger of the fire spreading and burning with such intensity as to
cause the fall of the bed of coal and superincumbent earth, the conse-
quent falling in of the shafts, and the inextricable loss of the bodies of
those below. They hastily called a meeting of colliery owners and
other persons in the neighbourhood, and it was not until fortified by
the approval of all that the managers decided on closing the shafts, and
thus smothering the fire. Before doing so, however, several venturous
men descended one of the shafts, rescued nineteen miners who had
saved their lives by clustering just at that spot, and then made two hours
of exploration under circumstances as frightful as men could well be
exposed to; dead bodies, dense volumes of sulphurous smoke, and
fiercely blazing masses of coal were what they came upon in all the
avenues and passages. When the dead and the living, so far as they
could be found, had been drawn up, the shafts were closed and the
mine flooded with water to quench the flames. It was a mournful
scene when, after the water had been again drawn off, the charred and
soddened corpses were drawn up one by one for Christian burial. Since
the accident no naked candles are allowed in the pit, and no blasting
with gunpowder, and the Lundhill colliery is again at work with its
hundreds of fearless miners."
We may turn from these scenes of misery to one of those rare pictures
which is presented annually in the coal-mine districts belonging to
that most noble lady the Marchioness of Londonderry, who once a year
entertains her workmen and miners to the number of three thousand
souls.
It is unnecessary to detail the quantities of good cheer consumed on
these occasions, or to report the speeches with which the banquet
terminates. The address par excellence is that of her ladyship, who
shows the benevolent interest she takes in those who contribute to her
wealth by the sound practical advice and affectionate admonition and
warning that she gives them, always entreating her miners to be careful

104
COAL AND COAL MINES.
and not to imperil their own or fellow-labourers' lives by removing the
wire gauze from their lamps to light their pipes or "fire their shots;"
PIT
ENCLANDS
ADELAIDI PIT
LONDONDE
FORDERNIST PIT
LADY WEARANC
Fig. 65. The Marchioness of Londonderry's Banquet to the Workmen and
Miners engaged in her Coal Fields.
but to remember their wives and families, the relations who depend upon
them for their daily bread. Her ladyship is not content only with mere
words, but by her numerous charitable acts shows that she is worthy of
the high station in which it has pleased God to place her.
Although much has been said about the working of the coal pits in
these pages, there are many practical facts which the limits of this
book oblige us to leave unnoticed; and having traced the coal to the
pit's mouth, the last points to be considered are the delivery, con-
sumption, and durability of the supply of the coal, not only to our
vast cities and manufactories, but to other countries, and especially
France.
No one should leave the coal district of Newcastle without paying
a night visit to the banks of the river Tyne, which is one of the
high-roads for the transport of enormous quantities of the "black fruit
of industry."

CARRIAGE OF THE COAL.
105
The scene is very imposing, the gigantic iron furnaces continually
sending out great flashes of fire, which light up the country as if
Fig. 66. A Scene on the Tyne.
with a general conflagration; the trucks full of coal continually
running down to the "staith machinery," by which the fuel is lowered
into the coal-brigs, the cressets burning, the men shouting, the con-
stant creaking of ropes and tackle, all indicate the bustle and work with
which the coal is shipped for home and foreign ports.
The construction and working of the staith machinery is thus de-
scribed by the author of "The Pits and Pitmen:" "From every pit a
tramway runs connecting the mine with a railway, or with one of the
thousand staiths which form so prominent a feature on the Tyne and
Wear. These staiths are high wooden jetties running far enough into
the river to allow ships to float at their extremities, even at low water.
The tramway runs from the pit to the end of the staith, the latter
usually forming an incline along which the loaded trucks, as they descend,
pull up the empty ones. The ship to be freighted lies at the end of
the staith; arrived there, the full truck is run upon a species of nicely-
balanced framework calculated to swing down with the weight from the
end of the staith, describing a fourth part of a circle, and coming to a
106
COAL AND COAL MINES.
rest just over the open hatchway beneath. The breaksman or rider
accompanies the truck in its descent, and, removing a bolt, he causes
the bottom to give way in trap-door fashion, and the load of course
sinks into the hold; while the well-balanced framework, immediately

GANGWAY
NDING
CRADLE
WATER SURFACE IN THE DOCK
POURTEABALANCE
WEIGHT
M
Fig. 67. One of the Forms of Staith Machinery.
rising as the weight is taken from it, swings up again to its former
position, and the empty waggon runs up the incline as the next loaded
one comes down. By this system the largest class of collier lading
at a staith will have her cargo aboard in a tide. In the hold a
gang of trimmers' are at work distributing the coals, as the crews
of the coal vessels never meddle with the cargo, either to stow it
away, or in London to heave it out. The dingy fleet of colliers is
calculated to be able to furnish at least 20,000 scamen to the British
navy, in case a maritime war unhappily broke out."
Seeing the constant annual drain of sixteen million tons of coal from
the northern pits, the question is naturally suggested, How long can
this state of things last, and what is the period that calculation assigns
for the duration of the supply?
We are assured by Professor Hunt, the keeper of the Mining Records
ANNUAL PRODUCE OF COAL.
107
of the Government School of Geology and Mines, that the total annual
produce of our three thousand British coal mines is not less than
"SIXTY-EIGHT MILLIONS OF TONS!!"
10
"It is very difficult [says a writer in the Edinburgh Review'] to
convey an adequate conception of this vast produce; but if, as a
collier has calculated, these sixty-eight millions of tons were excavated
from a pit gallery six feet high and twelve feet wide, such a gallery
must be 5128 miles and 1090 yards in length. Or if, instead of this
tunnel of more than five thousand miles, we prefer the conception of
a solid globe, then the diameter of a globe containing this annual
produce must be 1549 feet. Should a pyramidal form be chosen,
then this quantity would constitute a pyramid the square base of which
would extend forty acres, and the height of which would be more than
3356 feet. The great Egyptian pyramid of Ghizeh covers an area of
more than thirteen acres, and rises a hundred and nineteen feet higher
than St. Paul's, and twenty years were occupied in its erection. In
England one year suffices, with the industry of 200,000 persons, to
dig out coal that would build several pyramids as large as that of
Ghizeh."
Professor Rogers, the State geologist of the Government of the
United States of America, gives the following
Summary View of American and European Coal Fields.
"The aggregate space underlaid by the vast coal fields of North
America amounts to nearly 200,000 square miles, or to more than
twenty times the area, including all the known coal deposits of Europe,
or indeed of the whole Eastern continent. Comparing the assumed areas
and solid contents of the coal fields of other countries with those of
North America, we have the following results :-
cr
"I. Estimated Areas of Coal in Principal Countries.
• United States
Total sq. miles.
196,650 sq. miles of coal area
British Provinces of N.
200,000
America
7,530
وو
Great Britain.
5,400
France.
984
وو
Belgium
510
Rhenish Prussian Saar-
brücker coal field
960
Westphalia
380
8,964
Bohemia
400
Saxony.
Spain
Russia.
30
200
"
100
•
108
COAL AND COAL MINES.
II. Estimated Quantities of Coal in Principal Countries.
Tons.
"Belgium (average thickness, 60 feet of coal)
France (about the same thickness)
British Islands (average thickness 35 feet).
Pennsylvania (average thickness 25 feet)
•
36,000,000,000
59,000,000,000
190,000,000,000
316,400,000,000
Great Appalachian coal field (same thickness) 1,387,500,000,000
Indiana, Illinois, Western Kentucky (25 feet) 1,227,500,000,000
Missouri and Arkansas basin (10 feet in
thickness)
All the productive coal fields of North
America, assuming thickness of 20 feet of
coal over 200,000 square miles
739,000,000,000
. 4,000,000,000,000
"III. The Ratio of the Estimated Quantities of Coal in the more
important of these several coal countries is shown approximatively in
the following series of numbers, making the coal of Belgium, or
36,000,000,000 (thirty-six thousand million) tons, a unit of measure:-
" Amount of coal in Belgium.
33
"
>>
""
""
دو
ور
رو
وو
France, less than
British Islands, rather more than .
Pennsylvania, a little less than
Appalachian coal fields, about.
Missouri and Arkansas basin
entire coal fields of North America
all Europe.
""
""
1Q
2
9
38/1/2
201/2
111
S3"
In 1801 Mr. Bailey predicted the supply of the Durham and
Northumberland coal fields would only last 200 years; in 1830 Dr.
Buckland granted a larger period of 400 years; in the same year
Professor Thomson extended the time to 1000 years; and Mr. Hugh
Taylor exceeded all previous calculations by granting 1727 years.
Mr. Hall, more recently, by careful calculation, estimated the time to
be 331 years; which coincides precisely with the estimate of Mr.
Greenwell, made in 1846; so that it seems to be understood the great
coal fields of Northumberland and Durham will be hopelessly in-
poverished in about three hundred years.
In consequence of the immense consumption of coal in the iron fur-
naces and foundries of Staffordshire, it has been estimated that this coal
field will be exhausted some time before the Northern fields, for the
area of the former is scarcely more than one-half of the area of the
latter; and even Yorkshire, Lancashire, and Derbyshire are more than
living up to their income of coals. The quantity for supply being fixed,
and the quantity demanded being continually on the increase, the actual
period of exhaustion is not difficult to predict, though it may be unwel-
come to anticipate. We shall, however, have resources at that period
which will prevent a bituminous bankruptcy; and these will be found
HOW LONG WILL THE COAL LAST?
109
in one or more coal fields not at present so largely worked as those
previously named; particularly the great coal fields of South Wales will
afford an abundant supply for many years to come.
The whole ques-
tion of the durability of the supply of coal is brought up to the pre-
sent time in the following admirable review of the question by Professor
D. T. Ansted:
“As the extent of England's coal resources is an object of consider-
able interest at the present moment, perhaps the following statement
of facts and inferences may be useful to remove unnecessary alarm, to
suggest prudence in the management of so important an element of our
country's greatness, and at the same time to justify our public men in
permitting our neighbours to take a fair share of our mineral riches in
return for those productions which the climate of the Continent and
the ingenuity and industry of its people enable them to offer us in
exchange.
"There are in England nine distinct tracts of country where those
rocks come to the surface which are known to yield coal. These dis-
tricts are called coal fields; the smallest of them includes more than
60,000, and the largest more than 600,000 acres of coal lands, under
the greater part of which coal has been, is, or may be, worked to profit.
Scotland contains another million of acres of such coal lands.
CC
Besides these tracts, marked in our geological maps, there are others
exceedingly large, but less clearly made out, in which coal is also to be
got, although the coal-bearing beds are covered up with accumulations
of newer rocks. All these will be available when the price of coal
justifies the outlay that will be involved in mining them.
"The best known and largest of our coal fields are the Newcastle
and Durham, the Lancashire, the Yorkshire, the South Staffordshire and
Warwickshire, and the South Welsh. The ascertained acreage of coal
in these amounts to about 2 millions. Adding to this the million of
acres in Scotland, and half a million for the smaller areas, we have a
total of four millions of acres, or, in round numbers, 6000 square miles
of coal lands in the British islands.
"In none of these districts are there less than ten, while in some
there are more than seventy beds of coal known and described, each
capable of yielding coal to profit by the ordinary processes of mining.
Some of these beds are between one and two feet, most of them between
three and seven, and one between thirty and forty feet thick. Rarely
more than a small number of seams or beds of coal can be obtained
with advantage from the same area, but the average thickness of
workable coal may with safety be taken as not less than fifteen feet, or
five yards, over the whole area of any coal field.
tr
Now, as an acre contains 4840 square yards, and a cubic yard of
solid coal weighs nearly one ton, there thus appears to be 24,200 tons
of coal per acre of coal lands on a general average; but as a large
quantity of coal in every coal field is, from various causes, not obtain-
able, and another large part is lost by the ordinary mode of extraction,
we cannot calculate on more than one-third of this, say 8000 tons per
110
COAL AND COAL MINES.
acre, as the quantity that can be removed and sold. This would give
about 5,000,000 tons of coal for every square mile of coal lands.
"The annual consumption of coal at present in England cannot be
less than 80,000,000 tons, so that we are now exhausting about sixteen
square miles of our coal lands each year. Estimating the area of coal
lands at 6000 square miles, this would give a duration of rather more
than 350 years.
"It may be observed that the usual estimate of coal lands in England
is 12,000 square miles, and that in the smaller area I have taken, an
allowance is made for the unproductive portions.
"The coal area in Belgium and Rhenish Prussia together is not more
than one-eighth part, and in all France not one-fifth part that of Eng-
land and Scotland; the average thickness of coal is smaller, and the
position of those coals is generally less favourable in the former dis-
trict for extraction, and in the latter for transport to the sea.
"The quantity of coal known to exist in North America, both in the
United States and British possessions, is so large, that for all practicable
purposes it may be regarded as inexhaustible. Coal is also abundant
in India, China, Borneo, Eastern Australia, and South Africa.
"Owing to the advanced position of England in practical mining
operations, and the facility and economy with which she can place her
large supplies in the markets of the world, at a cost so low at present
as to exclude competition, her coal will no doubt be extracted very ra-
pidly for years to come. But should the advancing industry of other
countries reduce the price below that at which profit is secured by our
colliers, or should the cost of extraction increase with us out of propor-
tion to the rest of the world, the demand for exportation would be at
once checked, and the drain upon our resources would diminish.
"That this must happen very long before any approach to exhaus-
tion could be experienced, may be regarded as certain, and it must be
remembered that the price of iron (for the manufacture of which at
least half our coal is required) will to a large extent act as a regulator,
and prevent a too rapid extraction when the first symptoms of exhaus-
tion are felt.
"It is clear, then, that, like all other articles of commerce, the trade
in coal may safely be left to arrange itself, and will do so with greatest
certainty of benefit to all parties, both now and centuries hence, by
being left to its natural growth, restrained only by those checks which
nature has imposed."
We may now suppose that the collier brig has arrived in the vast
port of London, and that her cargo is to be offered for sale at the
market, viz., at the Coal Exchange, which is an ornamental building,
where one of the most stupendous trades in the world is carried on.
Mr. Timbs, in his most learned and entertaining work, "The Curiosities
of London," informs us that the Coal Exchange, up to 1807, was in the
hands of private individuals; in that year it was purchased by the
"Corporation" for 25,600l. In 1845 the coal trade petitioned for the
enlargement and rebuilding of the Exchange. This was done by the

THE SALE OF COALS.
111
City architect, J. B. Bunning; and the new Exchange was opened with
great éclat by Prince Albert, accompanied by the Prince of Wales and
Fig. 68. The Coal Exchange.
the Princess Royal, October 29, 1849, when the Lord Mayor (Duke),
himself a coal merchant, received a patent of baronetcy. The Exchange
has two principal fronts, of Portland stone, in the Italian style, one in
Lower Thames-street, and the other in St. Mary-at-Hill; with an entrance
at the corner by a semicircular portico with Roman Doric columns and a
tower 106 feet high, within which is the principal staircase. The public
hall, or area for the merchants, is a rotunda, sixty feet in diameter, covered
by a glazed dome seventy-four feet from the floor. This circular hall
has three tiers of projecting galleries running round it; the stancheons,
galleries, ribs of dome, &c., are iron, of which about 300 tons are used.
The floor of the rotunda is composed of 4000 pieces of inlaid woods, in
the form of a mariner's compass, within a border of Greek fret. In the
centre is the City shield, anchor, &c.; the dagger blade in the arms
being a piece of a mulberry-tree planted by Peter the Great when he
worked as a shipwright in Deptford dockyard. The entrance vestibule
Un

112
COAL AND COAL MINES.
is richly embellished with rows of fruit, arabesque foliage, terminal
figures, &c. In the Rotunda, between the Raphaelesque scroll sup-
ports, are panels painted with impersonations of the coal-bearing rivers
of England-the Thames, Mersey, Severn, Trent, Humber, Aire, Tyne,
&c., and above them, within flower borders, are figures of Wisdom,
Fortitude, Vigilance, Temperance, Perseverance, Watchfulness, Justice,
and Faith. The arabesques in the first story are views of coal mines-
Wallsend, Percy Pit-Main, Regent's Pit, &c. The second and third
story panels are painted with miners at work; and the twenty-four ovals
at the springing of the dome have, upon a turquoise-blue ground, figures
of fossil plants found in coal formations. The minor ornamentation is
flowers, shells, snakes, lizards, and other reptiles, and nautical subjects.
The whole is a polychrome by Sang. The gallery fronts and other iron-
work are cable pattern. The cost of the enlarged site, the building,
and approaches was 91,1677. 11s. 8d. In the basement, on the east
side of the exchange, are the remains of a Roman bath, in excellent pre-
servation, discovered in excavating the foundations of the new building;
and there is a convenient access to this interesting relic of Roman
London.
When the cargo is sold it is quickly transferred into large barges
called lighters, which contain five compartments, called "rooms," each
capable of holding seven tons of coal. The coal is further heaped upon
every available space, until the lighter is freighted with about forty-two
tons; and when the barge is open from stem to stern, it may be loaded
Fig. 69. Coalheavers at work
FORMER TAXATION OF COAL.
113
with fifty-five tons of coal. The work of unloading the coal brigs is
performed by the "whippers."
The duty is commenced by clearing the deck and opening the hatchways,
over which an iron wheel called a "gin" is rigged out, or a rope passed
over the top of a spar called the "derrick," at about eighteen or twenty
feet above the deck. A rope is passed over this wheel, and at one end
is slung the basket, and to the other four ropes are attached, which are
held by four men called coalwhippers. These men, as may be noticed
by any person passing by steamer from London to Blackwall, ascend some
steps or rails from the pull, and directly the signal is given they descend
rapidly, with a concluding jump, which brings the basket with a jerk
to the "measure," and when this is filled, a sort of blow is heard, and the
contents discharged by a broad trough into the "lighter" below. The
price of coals, as given in the London markets in the daily newspapers,
is the price up to the time when the coals are "whipped" from the ship
to the merchants' barges. It includes, 1st, the value of the coals at
the pit's mouth; 2ndly, the expense of transit from the pit to the ship;
3rdly, the freight of the ship to London; 4thly, the Thames dues;
and 5thly, the whipping. The emptied coal ships are ballasted to
Newcastle with gravel or sand chiefly dredged up from Woolwich
Reach.
In olden time, before a cargo of coals could be discharged from a
collier, it was necessary to obtain the permission of the Lord Mayor,
who, for a certain consideration, granted the required permission.
This much-honoured magistrate and his worthy coadjutors the alder-
men, with the common councilmen and livery, called the Corporation,
were permitted to lay a tax upon the "black diamonds" that amounted
to something like 50,000. per annum. In 1830 the heaviest of the
coal duties were abolished; and since that time the trade has as-
sumed those gigantic proportions which have made it the marvel of
the civilized world. The first licences to dig coals were granted to the
burgesses of Newcastle by Henry III., and in 1281 a very good trade
existed in that fuel. A proclamation in the reign of King Edward I.
shows the introduction of coal as a substitute for wood, and a charter
of Edward II. indicates that Derbyshire coal was used in London. In
the same reign coals were first sent from Newcastle for the benefit of
those trades which required fuel; and in 1316 a petition was made from
Parliament to the king praying his Majesty to forbid all use of the new
and pestilent fuel called "coals," which was acceded to, and a procla-
mation made, commanding all use of "coals" to cease and determine, and
threatening all who burnt coals to be mulcted, and on a second offence
to have their furnaces demolished. In the reign of Queen Elizabeth
the burning of stone coal was again prohibited during the sitting of Par-
liament. At a subsequent period, about 1618, coals were once more
placed under a ban; and, as if to annoy the brewers to the utmost legal
extent, the use of "hops" was at the same time forbidden. In 1520
Newcastle coal was first imported into Paris; but, as everybody knows
who has visited that city, wood has been preferred to the soot-producing
I

114
COAL AND COAL MINES.
mineral fuel. The Treaty of 1860 may work a remarkable change in
this respect, and Paris become the "black sister" city to London.
After the expenses of lighters and lightermen come those of wharfs,
officers and wharfingers, coalheavers, carmen, horses, waggons, sacks;
and, speaking of the latter, housekeepers should count their sacks before
and not after delivery.
P
Fig. 70. Delivery of the Coals. Coalheaver about to shoot the Coals into the Cellar.
The principle of contrast has always been recognised as one of
the most telling portions of an argument or scientific explanation,
because it is directly appreciated and understood. Thus we might talk
for ever of the bulk or weight of the coal contained in our mines, or of
the quantities annually consumed, without arousing any special wonder-
ment in the minds of our readers; but when we change the word coal
for its equivalent of human labour, and follow Mr. Henry Darwin Rogers
in his explanatory calculations, then our respect for coal as the equivalent
or exchange for human labour increases. Thus we are told "that each
acre of a coal seam, four feet in thickness, and yielding one yard net of
pure coal, is equivalent to about five thousand tons, and possesses,
therefore, a reserve of mechanical strength in its fuel equal to the life
labour of more than 1500 men. If we estimate a lifetime of hard human
work at twenty years, giving to each year 300 working-days, then we
have for a man's total dynamic efforts 6000 days. In coal this is repre-
sented by three tons; so that a man may stand at his own door while an
ordinary quantity of coals is being delivered, and say to himself: "There,

THE FIRE-SIDE.
115
in that waggon, lies the mineral representative of my whole working life's
strength!"
The railroads are now the greatest opponents of the water-borne coals,
and much to the satisfaction of Londoners. This great necessary of life
is no longer controlled by wind and weather, but is supplied in never-
ending successions of coal trains direct from the North to the streets
of London. A retired coal merchant informed the author that, in the
days of the supply by coal brigs, he once refused seven guineas a ton
for the best" Wallsends," and that four guineas per ton was a common
price formerly, when the City dues were exacted in all their ancient
rigour. The old collier brig is fast giving place to the clipper screw
steamer, which moves at least three times faster than the former, and
again places the sea-borne coals on a level with those conveyed per
locomotive.
May our readers ever enjoy the delights of a happy fireside.
ev
CONTIYASION ON
Fig. 71. "The last Scene of all"-Ashes.
I 2

EEVANS
Fig. 72. Alchemist in his Laboratory.
CHAPTER II.
THE ART OF ALCHEMY THE PREFACE TO THE SCIENCES OF
CHEMISTRY AND METALLURGY.
THERE is probably no branch of chemistry which is so intimately con-
nected with the alchemists as that important and very extensive section
that refers to the metals and metallurgy; for this reason it would
EGYPT THE BIRTHPLACE OF ALCHEMY.
117
hardly be doing justice to the subject if we omitted to say something
about the doings of these ancient pioneers of chemical science, who, as
Lord Bacon says, in their vain search for the philosopher's stone or the
elixir of life, were like the young men of the fable who carefully digged and
re-digged their father's field in search of a treasure which they never
found, but whose labour was amply repaid by the fertility of the soil
which they turned up with other intentions.
One of the greatest authorities on the literature of the subject is
Dufresnoy, who commences his celebrated history of "Hermetic Phi-
losophy" by telling his readers "that he is about to favour them with
the history of the greatest folly and the greatest wisdom of which man
can be capable;" and he very properly asks whether there is anything
more insane than the wish to change the inherent nature of created
things and to take to oneself, as it were, the supreme power of the
Great Creator, or anything wiser than the desire to be prosperous and
possess health and riches, to have the power to help friends and to so-
lace the miseries of the poor? "Such are the men of whom," adds Dufres-
noy, "I pretend to speak, and amongst whom are to be found plenty of
foolish but very few wise men.
دو
Dufresnoy then disclaims the idea of tracing back alchemy, or the
art of transmutation, to the time of Tubal Cain, who is supposed by
some authors to be identical with the Vulcan of mythological history;
he will not accept the wild and mad-brained theory of the art being
originally taught as the pretium amoris to mankind by the bad angels;
in fine, Dufresnoy considers it is taking the history too far back to place
it in the 1656 years that preceded the Deluge, and remarks, that it is
sufficient to commence it long after that general inundation of the uni-
verse. In this judgment we think our readers will entirely concur; and,
without troubling themselves to inquire whether Noah did or did not
possess the fabulous elixir of life, or whether one of his descendants, Cham,
was the first king of Egypt, formerly called Chemia, from Cham, and that
from his name arose the name of chemistry-without entering upon
such learned discussions, the students of alchemical history are satis-
fied to begin with the name of "Hermes Trismegistus," whose name is
celebrated amongst the ancient Egyptians as the inventor of the arts
and sciences, and especially physic, and who is said to have lived in the
year of the world 2076. And here it may be mentioned that there are
two great Egyptians of the name of Hermes; thus Hermes the Elder
is supposed to be the same with Mizraim, or Canaan, the grandson of
Noah; and Hermes Phthoth, or Mercury, surnamed Trismegistus the
Younger, is supposed to have been the son of Mizraim; and it is in
this way that the hermetic art is traced to the descendants of Noah.
It is right to observe (for the benefit of those profane persons who
would laugh outright if the foundation of chemistry was ascribed to a
descendant of Noah) that this notion is founded on the work of Dio-
dorus Siculus, of Agyrium, in Sicily, a celebrated historian and contem-
porary of Julius Cæsar and Augustus, who wrote his works about the
beginning of the Christian era, and awarded the honour of the dis-
118
ALCHEMY.
covery of chemistry to the Egyptian Hermes. No less than 36,000
books are said to have been written under the name of Hermes; but
this prolific and astonishing authorship, surpassing even that of Dumas,
is explained by Jamblichus, who states that a custom prevailed of in-
scribing all books of science with the name of Hermes. As Moses was
learned in all the learning of the Egyptians, to him is also ascribed a
knowledge of hermetic chemistry, or philosophy, affectedly called the
sacred and divine art. Bishop Wilson, however, in one of his "Che-
mical Essays," denies the scientific skill of Moses, and says, "We have
no reason to conclude that Moses either used the process of Stahl, or
any other chemical_means, for effecting the purpose intended;" and by
quoting the verse, Exod. xxxii. 20, the worthy divine at once brings the
theorists to facts: "He took the calf which they had made, and burnt it
in the fire, and ground it to powder, and strewed it upon the water, and
made the children of Israel to drink of it." There is not the least inti-
mation given of the gold having been dissolved, chemically speaking, in
water. After the form of the calf had been destroyed by melting in
the fire, it was stamped and ground, or, as the Arabic and Syriac ver-
sions have it, filed into a fine dust, and thrown into the river of which
the children of Israel used to drink. Part of the gold would remain,
notwithstanding its greater specific gravity, suspended for a time on the
surface of the river, as may be easily proved by placing some gold leaf
into a tumbler of water; and if the same kind of agitation be imparted
to it as would prevail in a river, the gold might be swallowed with the
water in the manner described by the sacred historian. Had the Is-
raelites taken the gold in a state of chemical solution, they must have
imbibed a rank poison.
The next in honour as an ancient student of chemistry, is Democritus,
a celebrated Greek philosopher, who lived about 460 B.C., and is stated
to have been the founder of the "atomic theory." Democritus was
quite an ancient Humboldt, and his knowledge, like that of the latter
philosopher, appears to have been most extensive, and embraced not
only the natural sciences-mathematics, mechanics, grammar, music,
and philosophy-but various other useful arts. Democritus, like Baron
Humboldt, travelled into many distant countries solely in pursuit of
knowledge. When it is stated that Democritus was the founder of the
atomic theory, it is not to be supposed that he knew anything of the
generalizations of chemistry, discovered only by analysis, or of the true
meaning of the term equivalent: all that he disputed about was the
finite or infinite divisibility of matters; and he was unable to affirm the
simple truth that 8 is the equivalent or combining quantity by weight
of oxygen, that 1 is the equivalent or combining proportion by weight
of hydrogen, and that the two united make the equivalent of water, 9
or, indeed, to state the equivalents, or combining proportions by weight,
of any or all of the sixty-three elementary bodies. If the nature of an
element had been understood from the time of Democritus, we should
have heard little or nothing of alchemy, for common-sense would as soon
have thought of converting an elephant into a black beetle as to change
THE HOLY OR SACRED ART.
119
lead into gold. There can be no doubt that the Egyptians, the Chinese,
and the Hindoos have, from time immemorial, exercised the arts of
agriculture, sculpture, the working of metals, glass-making, and pottery.
Their acquaintance with textile materials and the art of dyeing was by
no means insignificant, whilst the stone pictures on the tombs at Thebes
and elsewhere tell us of the conviviality and good cheer of the ancient
Egyptians, and of the wine they made and the beer they brewed; but
these same monuments give no hint of a knowledge of chemistry. There
were three great periods of Egyptian art-viz., the Archaic, the ancient
or obsolete, marked by the erection of the pyramids; the Theban, or
most renowned period; and the Ptolemaic, or third period, when Egyp-
tian art declined; and it may be supposed that it was at this period the
"sacred art," or the attempt by the Egyptian priests to change the base
into the precious metals, commenced, and which it was death to reveal
to the uninitiated. The experiments of the Egyptian priests were con-
ducted secretly in their temples, and the punishment of the peach-tree,
which M. Hofer conjectures to have been nothing less than a dose of
prussic acid prepared by distillation from the crushed stones or leaves of
some member of that family of plants, was awarded to those weak
votaries who betrayed the secrets of the so-called holy or sacred art.
χημια,
C
C
Humboldt, in his notes to “Cosmos," says "The name chemistry indi-
cates literally Egyptian art'-the art of the black land; for Plutarch
("De Iride et Osir,"cap.33) knew that the Egyptians called their country
xnuia, from the black earth. The inscription on the Rosetta stone has
Chmi. I find the word chemie, as applied to the decomposing art, first
in the decrees of Diocletian against the old writings of the Egyptians
which treat of the chemies of gold and silver (περι χημιος αργύρου και
Xpvrov)." The gaps in alchemical history are very wide, and we are
obliged to leap to the second century of the Christian era, when Dio-
scorides, of Anazarba in Cilicia, a Greek physician, appears upon the
scene as a practical philosopher, and the inventor of the technical art
of distillation. About the same period Alexander of Aphrodisias de-
scribed the distillation of sea water, and also indicated the distillation
of wine. The art of distillation would make men acquainted with
liquids having stronger power of effecting solution than water, and
hence the learned Humboldt remarks, "that chemistry first begins when
men have learnt to employ mineral acids as powerful solvents."
The work on "Materia Medica" written by Dioscorides is still extant,
and was for many years received as a standard production. Suidas, a
Greek lexicographer, who is thought to have lived in the tenth century,
states that Diocletian ordered all the books on chemistry to be burned,
lest the Egyptians, learning from them the art of preparing gold and
silver, should thence devise resources to oppose the Romans. The edict
of Diocletian occurred in the third century, but did not stop the pro-
gress of the fascinating art of alchemy. Suidas also defines chemistry
to be the art of making gold and silver, and boldly explains the my-
thical story of the Argonauts and the Golden Fleece as an expedition
undertaken to obtain a book teaching the profitable art of gold-making,
120
ALCHEMY.
which was supposed to have been written by Hermes, the Egyptian
king already alluded to.
One cannot help regretting that the epochs of chemical discoveries
are so widely separated; and now we come per force to the period of
the Arabians and the labours of Geber, or rather Abou Moussah
Djafar, al Sofi, who flourished about the end of the eighth century,
and is stated to have made the important discoveries of nitric and sul-
phuric acids, aqua regia, alcohol, and the preparations of mercury and
other metallic salts. The preparation of nitric acid and aqua regia by
Prince Geber is more than 500 years anterior to Albertus Magnus and
Raymond Lully, and almost 700 years anterior to the expert monk,
Basilius Valentinus. Nevertheless," adds Humboldt, "the discovery
of these decomposing [dissolving] acids, which constitute an epoch in
chemical knowledge, was long ascribed to the three last named
Europeans."
Whilst speaking of the refinement and learning of the Arabians at
the period Prince Geber lived, it must be remembered that about 150
years before his time, Amrou, the lieutenant of the Caliph Omar,
A.D. 651, had set fire to the immense library of Alexandria (which had
already suffered severely by fire when Julius Cæsar was besieged in
Alexandria), and totally destroyed it; to the great grief, no doubt, of all
learned persons at that period, but especially of the philosophers who
succeeded Geber. They never ceased to affirm that most probably the
secret of transmutation could have been procured from the ancient
books on hermetic philosophy in the Alexandrian library; and having
declared the art of transmutation already discovered, their efforts were
to be regarded as attempts to revive the lost precious secret.
If Geber lived about the end of the eighth century, he must have
flourished in the reign of that most celebrated of Arabian potentates,
the Caliph Haroun al Raschid, whose name will live for ever in the de-
lightful fictions of the "Arabian Nights' Entertainments." The latter
monarch had removed the seat of royalty from Damascus to Bagdad;
"and that city," says Dr. Crichton, in his "History of Arabia," "then
became the resort of poets, philosophers, and mathematicians from every
country and of every creed. Ambassadors and agents in Armenia,
Syria, and Egypt were ordered to collect the most important books
that could be discovered. Hundreds of camels might be seen entering
Bagdad, loaded with volumes of Greek, Hebrew, and Persian literature;
and such of them as were thought to be adapted to the purposes of in-
struction were, by the royal command, translated by the most skilful in-
terpreters into the Arabic language, that all classes might read and
understand them. Thus it happened that the great works of Aristotle
were only known and translated from the Arabic in later periods.
Dioscorides, A.D. 200, describes the distillation of mercury from cin-
nabar by means of an embic, or rather ambix, a Greek word signifying a
kind of cup, or cover of a pot, from which, by adding the Arabic al,
signifying the, we have Alembic, or rather Al-ambic; whilst the word
Alchemy, which appears to have been specially adopted about the time
cr
THE ARABIC WORD AL," THE.
121
of Geber, is likewise derived from the Arabic, and means—al, the, and
kema, dark or secret; indeed, the reader will have little difficulty in re-
cognising terms of Arabic derivation in the words, Al-kali-al, the, and
kali, a marine plant, now called glasswort, or marsh samphire; also in
Algebra, Alcoran, Alcove, Almanack, Alcahest, or universal solvent, and
many others.
It is difficult to say what kind of vessels were employed by the
Egyptians or their successors in hermetic philosophy; and it is not until
we come to the period of Geber that we are enlightened as to the forms
and peculiarities of chemical glasses, and the construction of furnaces.
These were aludels, or adopters; curcubites, or retorts; alembics, or
lymbeckes; matrasses, or bolt-heads; pellicans, or digesters. Some of
the chemical vessels invented by Geber are still employed in certain
metallurgical operations, and retain their original names; thus in Alma-
den, a famous mining district in Spain, in New Castille, where of course
many traces of the Moors, the descendants of the ancient Arabians,
would remain, they still employ the "aludel" furnace for the distillation
of mercury from the ore.
A
A
A

Fig. 73. Mode of arranging the Aludels or Adopters, at Almaden, for the condensation of
the mercurial vapour. At ▲ ▲ ▲ the joints are closed with a clay lute.
These adopters, in twelve long rows of twenty-five each, are connected
with a large circular chamber, in which the ore of mercury is placed,
and after the heat has been applied for about twelve hours, the mercury
is driven off, and by means of the aludels and other parts of the con-
densing arrangement, the mercury is obtained in the liquid state. It is
said that the Almaden quicksilver mines have produced more than ten
million pounds in one year.
Sir H. Davy very properly remarks that the "apparatus essential to
the modern chemical philosopher is much less bulky and expensive than
that used by the ancients. All the implements absolutely neces-
sary may be carried in a small trunk; and some of the best and most
refined researches of modern chemists (such as those of Dr. Wollaston)
have been made by means of an apparatus which might with ease be
contained in a small travelling-carriage, and the expense of which is
only a few pounds. It was said by an author belonging to the
last century of alchemy, that its beginning was deceit, its progress labour,
and its end beggary. It may be said of modern chemistry, that its
beginning is pleasure, its progress knowledge, and its objects truth
and utility." There are no doubt great intellectual qualities necessary
for discovery or for the advancement of science.
•
In Zweibrucken (two bridges), in Bavaria, large quantities of mer-
cury are distilled from the ore, which is placed in a number of earthen
curcubites, or ancient retorts. These are all arranged in one gallery, where
122
ALCHEMY.
the heat is applied, and their mouths fitted into receivers containing a
certain portion of water.

B
A
A
B
І
Fig. 74. ▲, ▲, Curcubites containing Mercurial Ore. B, B. The Receivers
half full of Water.
That the alchemists used their curiously-twisted and distorted chemical
vessels to some purpose is shown, not only in the chemical results of
their labours, but likewise in the remarkable speculations they made
with respect to future wonders in science and the mechanical arts.
These anticipations became almost prophetic when clothed in the noble
and enthusiastic language of such a man as the good old learned Friar
Bacon, truly one of the "good old monks," and depositaries of that
scanty amount of learning saved from utter oblivion in some of the
monasteries and religious houses of Europe. Thus Bacon says:-
"Bridges unsupported by arches can be made to span the foaming
current; man shall descend to the bottom of the ocean, safely breathing,
and treading with firm step on the golden sands never brightened by
the light of day. Call but the secret powers of Sol [heat] and Luna
[cold] into action, and behold a single steersman sitting at the helm,
guiding the vessel which divides the waves with greater rapidity than if
she had been filled with a crew of mariners toiling at the oars. And the
loaded chariot, no longer encumbered with the panting steeds, darts on
its course with relentless force and rapidity. Let the pure and simple
elements do their labours; bind the eternal elements and yoke them to
the same plough."
Here we have suggested, in the middle of the thirteenth century,
suspension-bridges, diving-bells, and submarine apparatus such as a
modern Heinke would have improved upon. Coal fires and steam con-
densed by cold are suggested for propelling ships, whilst steam-carriages
and locomotives relieve the panting steeds. Let the pure and simple
elements-meaning earth, represented by fuel, air to feed the furnace,
fire to boil the water, and water to generate the steam-do their
OLD ALCHEMICAL VESSELS.
123
labours. How far Friar Bacon's recommendations have been at-
tended to we perceive in the colossal Britannia tubular bridge and the
mammoth Victoria bridge, which his Royal Highness the Prince of
Wales has so lately opened with such éclat in Canada, and in the com-
plete success of diving apparatus; likewise in the almost countless miles
of road only used by steam horses-all honour to Friar Bacon!
The next cut, taken from a chemical book printed in 1662 (two years
after the restoration of King Charles II.), with its quaint drawing and
spelling, affords a good idea of the shape of the glass vessels employed
for chemical experiments; and they are, no doubt, nearly all copies of
those originally proposed by Geber.
BAJ JBC J

1
2
3
4
12
g d O l l O
7
13
8
9
14
10
วงนี้
17
15
16
Fig. 75. 1. A Pellican, or circulating vessel. 2. Another vessel of circulation. 3. An
infernall glass. 4. A Matrace, or boult head, with a flat bottom. 5, 5. A Troir, or double
Pellican. 6. A Matrace, or boult head. 7. An Alimbick made of one peece, or a head and
body joyned at the first making. 8. The Phylosopher's egg. 9. A double egg, or one
within another. 10. A little Matrace. 11. A separating glass. 12. A blind head, or a
head without a beak. 13. A receivour. 14. A glass funnell. 15. A Cornue, or a retort.
16. A Curcabit, or a body for an alimbick. 17. A ring, or round roule of straw, to hould
glass vessels.
The heat-giving agents employed by the alchemists were both natural
as well as artificial; thus, the rays of the sun were not forgotten, but
were made use of, and reflected by a mirror on to the alembic, from which
the distilled liquid passed. (Fig. 76.)
124
ALCHEMY.

Fig. 76. Sun's Rays reflected on to an Alembic by a concave Mirror.
Or else the curcubites, or vessels with long necks, used sometimes for
retorts, were placed directly in the sun's rays, and the operator was re-
commended to use this kind of heat only in the months of July and
August.

мне
Fig. 77. Alchemist placing Curcubites in the Sun. The Assistant is occupied grinding
and mixing the Lute for closing the Curcubites.
H
THE FURNACES OF THE ALCHEMISTS.
125
One of the great achievements of Geber was the construction of his
large furnace, or Tower of Athanor, which was provided with a some-
what lofty receptacle, called the Turret, for the fuel, and as the lower
portion burnt away, the combustible matter continued to descend, so
that it was like a modern furnace fitted with a hopper, and as long as
the upper part, D, was kept full of coal or charcoal, it never went out,
and was hence called the Athanor, or undying one.
It is to be noted in these Figures and the following There are some Geometrical, some
Optical made with a weake shade, the better to discerne the internal parts, which are onely
represented with punctuated lines.

g.
Bath of
Sand, or
fire of
Ashes
x
Tower of
Athanor.
I
Balne um Maris.
[Fig. 78. The Tower of Athanor.]
1. the ashe hole.
2. the focus or fire roome.
3. the place where the ashes.
or Sand for the Bath are
placed.
4. a Matrasse.
5. a glasse dish.
6. the Register of fire.
7. the entrance of the fire or
heat from the Tower of
Athanor.
8. the Iron plate or Vessel
a. the ashe hole.
b. the focus or fire
roome.
c. the passages made
1. the ashe hole.
2. the focus.
3. the kettle where the water
of the Balneum is put in.
for comunication of 4. a round (of wood, hay, or
the fire.
d. the empty place of
the Tower.
e. the solid part of the
Tower.
f. the cover of the
Tower.
containing the Sand or g. two severall circles
ashes.
wherein the cover
is inlayd.
some other soft matter) to
keepe vp the Limbeck body.
5. the curcubite with its Lim-
beck head.
6. the Registers of fire.
7. the stoole or table to keepe
up the Recipiem.
8. the Recipiem.
126
ALCHEMY.
This arrangement is highly commended by Le Febure, 1662, for the
following reasons: "Because this furnace is not only the most useful
of all others to perform at the same time several operations, but also
because it saves coals, easeth the care and assiduity of the artist, and
yields a heat easily to be regulated. The Athanor is consisting of four
parts. The first is the turret containing the coals; the second, or
Balneum Maris [water bath]; the third, an ash; the fourth, a sand
furnace."
The alchemists do not appear to have confined themselves only to the
use of the sun's rays or the furnace, but employed the heat arising from
Vessel to separate
the distilled Oyles.
3
Furnace and Vessels
for the Distillation of
Waters, Spirits, and Oyles.

2
1
9
C
m
a. the fire.
[Fig. 79. Alchemical Distillation.]
b. the glasse body for distillation (vesica).
c. the Moores head.
1. a tub to receive the water let out.
m. the barrell or caske containing the water
to coole and condense the spirits.
d. the iron bar which keepes vp the glassen. the prop or support of the barrel or
body.
f. the Registers of the fire.
g. the pipe or nose of the Moores head.
h. the pipe (sometimes worme) passing
through the barell full of water.
i. Recipiem.
cask.
1. a stoole or small table to keepe out the
recipiem.
2. recipiem with the water to be separated.
3. Cotton drawing the oyle and swiming
aboue the water.
k, the cock to draw out the water when it 4. Oyle swiming above the water.
must be changed.
5. a small glasse viall to receive the Oyle.
THE WORKS OF GEBER.
127
dung in a state of putrefaction or fermentation, and likewise lamp or
candle heat. It is impossible to assert that Geber ever worked with
any other heat than that of his Athanor, although to such a close
observer of " common things" the constant burning lamp might have
suggested its own application.
Dr. Johnson, the great lexicographer, asserts that the origin of the
word gibberish, signifying that which is very outlandish and difficult to
understand, arises from the name of Geber, because his works were
written in such a very unintelligible style; but the great difficulty is
to affirm what Geber really did write, because his name is made use
of as the author of a great number of trumpery, nonsensical books on
alchemy, with which he had really nothing whatever to do; in fact, the
dishonest alchemists of later times merely adopted his name to sell their
trash, which they neither understood or believed in themselves. Wit-
ness Salmon's "Geber," from which we will quote a few lines, and then
compare them with some of the genuine writings of Prince Geber,
which have been carefully collected by Hafer.* Salmon makes him say,
with a vast deal of other trash, referring to the Philosopher's Stone,
Hence we define Our Stone to be a generalizing or Fruitful Spirit and
Living Water, which we name the Dry Water, by Natural proportion
cleansed and United with such Union, that its principles can never be
separated one from another; to which two must be added, a third for
shortening the work, and that is one of the perfect Bodies attenuated
or subtilized."
'
The reader can well imagine unhappy believers in transmutation
wading through such muddy instructions, and after spending their time
and money, having literally nothing for their trouble. No doubt poor
Geber's name has often been sadly reviled by unsuccessful searchers
after the stone; whereas, if they could have obtained his genuine works,
they would have discovered that he denies the possibility of transmuta-
tion, and gives advice that might be printed and hung up in every labo-
ratory. "The chemist," says Geber, must be sound in mind and
in body; he who suffers himself to be led away by his imagination, his
vanity, or his vices, is as incapable of success as if he were blind or
mutilated. The greatest patience and sagacity are required. When a
difficult experiment has been commenced, which does not at first suc-
ceed, we must take courage to persevere, and follow it to the end, never
stopping half way; for an imperfect and unfinished work, far from being
useful, is hurtful to the progress of science." With respect to trans-
mutation, he says, "It is as impossible to transmute the metals as it is
to change an ox into a goat; for, if nature employs a thousand years to
form the metals, how shall we pretend to do so whose lives are so brief?
It is true that the heat we employ may produce sometimes, in a short
period, that for which nature requires years, but how slight is the
advantage in this respect!"
Geber was well acquainted with, and described, the properties of gold,
Histoire de la Chimie," par F. Hæfer.
128
ALCHEMY.
silver, mercury, copper, tin, iron, lead, and arsenic. He was also ac-
quainted with the processes of sublimation, distillation, calcination,
solution, crystallization, and he fully explains the art of assaying gold
and silver by the cupel; also the preparation of nitrate of silver, corro-
sive sublimate, red oxide of mercury, liver and milk of sulphur, the mineral
acids, caustic potash, magnesia, sal-ammoniac, and phosphate of soda.
Geber, like those who had preceded him, believed that the metals were
of a compound nature, and consisted of mercury and sulphur, with occa-
sionally a third element, arsenic, from whose varying proportions and
modes of combination the difference among them resulted.
Geber's mercury, sulphur, and arsenic were not the real substances,
having the ordinary characteristics of these metals, but were certain
imaginary and theoretical principles supposed to exist, real elements of
matter, and from which all the metals were supposed to originate.
Geber's successors lost the meaning of the great chemist's elements,
and thus degenerated into the fanciful notion of metals growing from
seeds, just as if they were endowed with the living organism of plants.
It is from the Arabians we have the abbreviations of words by signs,
which save their constant repetition, as in the well known signs of plus
and minus; and no doubt from the same refined people originated the
alchemical signs for the metals and other chemical substances. These
signs are now only seen upon the show bottles of chemists' shops, and
some of them probably will be recognised in the next cut.

Gold
Mercury
OF
Lead
h
Arsenic
Iron
Silver
Tin
Antimony
Copper
О
Fig. 80. Alchemical Signs of the common Metals.
ALBERTUS MAGNUS.
129
Prince Geber appears to have been succeeded by several learned
Arabians, amongst whom particular notice is made of Alfarabi, who was
murdered by some thieves in the deserts of Syria, A.D. 954, and also of
Avicenna, whose real name was Ebn Cinna. This alchemist was born
at Bokhara, A.D. 980, and, in consequence of the great reputation he en-
joyed as a physician and alchemist, was made Grand Vizier by the
Sultan Magdal Dowleth. This elevation is stated to have led to his
moral degradation and downfall, as he was dismissed from his office in
disgrace and died prematurely, worn out by debauchery, A.D. 1036.
After the lapse of about 150 years from the period of the last-named
alchemist, and 400 years from the time of Geber-viz., in the year 1193
—the celebrated Albertus Magnus was born, who, with his pupil Thomas
Aquinas, made great exertions to obtain the philosopher's stone and
elixir vitæ. It was this clever man who constructed the "Brazen Head"
which had the power of talking, and on one occasion it chattered so
fast that Thomas Aquinas took up a hammer and broke it to pieces.
The Brazen Head must have been some acoustic contrivance by which
the voice was rendered audible, most probably through the medium of
an ordinary speaking-pipe. It is Albertus Magnus who was said to
have the power of changing the course of the seasons, and the story is
thus related by Charles Mackay * from Lenglet's "Histoire de la Phi-
losophie Hermetique." Albertus was desirous of obtaining a piece of
ground, on which to build a monastery, in the neighbourhood of Cologne.
The ground belonged to William, Count of Holland, and King of the
Romans, who, for some reason or other, did not wish to part with it.
Albertus is reported to have gained it by the following extraordinary
method:-He invited the Prince, as he was passing through Cologne,
to a magnificent entertainment prepared for him and all his court. The
Prince accepted it, and repaired with a lordly retinue to the residence
of the sage. It was in the midst of winter; the Rhine was frozen over,
and the cold was so bitter that the knights could not sit on horseback
without running the risk of losing their toes by the frost. Great, there-
fore, was their surprise, on arriving at Albert's house, to find that the
repast was spread in his garden, in which the snow had drifted to the
depth of several feet. The Count in high dudgeon remounted his
steed; but Albert at last prevailed upon him to take his seat at the
table. He had no sooner done so, than the dark clouds rolled away
from the sky, a warm sun shone forth, the cold north wind veered sud-
denly round, and blew a mild breeze from the south; the snows melted
away; the ice was unbound upon the streams, and the trees put forth
their green leaves and their fruit; flowers sprang up beneath their feet,
while larks, nightingales, blackbirds, cuckoos, thrushes, and every sweet
song-bird sang hymns from every tree. The Earl and his attendants
wondered greatly; but they ate their dinner, and in recompence for it
Albert got his piece of ground to build a convent on. He had not, however,
shown them all his power. Immediately that the repast was over, he
"Memoirs of Extraordinary Popular Delusions," p. 16.
K
130
ALCHEMY.
gave the word, and dark clouds obscured the sun; the snow fell in large
flakes; the singing birds fell dead; the leaves dropped from the trees,
and the winds blew so cold and howled so mournfully, that the guests
wrapped themselves up in their thick cloaks, and retreated into the
house to warm themselves at the blazing fire in Albert's kitchen. The
sober reader would at first class this story with all other tales of won-
derful necromancers and sorcerers, until he remembers that a tropical
warmth and an abundance of growing plants, flowers, birds, is to be
seen during the severest winters at the Crystal Palace and other places;
and that most probably Albertus Magnus constructed the first winter
garden, where he maintained an agreeable warmth, and charmed and
astonished Wilhelm of Holland on the 6th of January, 1249, with this
delightful novelty. As the company retired from the winter garden to
finish the evening in Albert's kitchen, a great contrast would be apparent
in the falling snow and the usual severities of winter; and if any of the
birds had accidentally escaped from their glass-house at that moment,
no doubt the intense cold might have caused their death, whilst pro-
bably, to show the King of the Romans that it was artificial heat which
alone produced the results he had witnessed, some of the plants might
have been placed outside, where their leaves would soon curl and betray
the usual effects of Jack Frost. The first winter garden or hothouse,
in the garden of the Dominican convent at Cologne, suggested this fable
of Albertus Magnus. It would be an endless task to relate the histories
of all the alchemists who lived in the period between the twelfth and
seventeenth centuries; and therefore we shall only speak of the doings
of the greatest celebrities, and content ourselves by merely naming the
others.
دو
Artephius, Alain de Lisle, Arnold de Villeneuve, Pietro d'Apone,
Pope John XXII., Jean de Meung, Isaac and John of Holland, belong
to the thirteenth and fourteenth centuries; likewise Raymond Lully
and Roger Bacon, both of whom deserve notice here: the former be-
cause he appears to have been the first scientific Master of the Mint,
being invited to England by King Edward, who assigned him apartments
in the Tower of London, where he refined much gold and superintended
the coinage of the "Nobles of the Rose; and it is affirmed, made
gold out of iron, quicksilver, lead, and pewter, to the amount of six
millions. These statements, however, are denied by the writer in the
Biographie Universelle," who states that Raymond Lully never visited
England, but his name has been mistaken for another Raymond, a Jew
of Tarragona. Raymond Lully is worthy of praise, because he adopted
Prince Geber for his model, and, instead of pursuing the pretended arts
of astrology and necromancy, he studied most diligently the nature and
properties of the metals. If this was the case, and he became intimately
acquainted with the modes of refining gold and silver, no doubt Lully
might have been of great service to King Edward, who is said to have
detained him prisoner in the Tower, from which he ultimately escaped.
<<
Both Raymond Lully and Roger Bacon were contemporaries of Al-
bertus Magnus, and all three were extraordinary men of the age they

ROGER BACON.
131
lived in. If the palm of superiority may be awarded to either, it would
seem to belong to the famous Roger Bacon, or Bachon, as it is spelt in
William Salmon's translations of the "Radix Mundi," and "Speculum
Alchimia," alleged to have been written by the learned friar. He was
born at Ilchester, in Somerset, in the year 1214, and, after studying at
Oxford and Paris, Roger Bacon became a monk of the Franciscan order;
and, had he contented himself with the performance of his chemical ex
periments and ordinary duties, no one would have interfered with the
philosopher; but, taking upon himself to attack many of the dogmas of
the Church, and to reform the abuses which had crept into the order of
St. Francis, his brethren seem to have taken umbrage at these attacks
and charges, and, seeking an opportunity to revenge themselves upon the
reformer, he was very soon accused of witchcraft and sorcery, cast into
prison, and nearly starved to death. He is said to have discovered many
optical contrivances, such as the telescope, the use of concave and con-
vex lenses, the magic lantern, and other effects of glass lenses; and,
Fig. S1. The House of Friar Bacon, at Oxford.
K2
132
ALCHEMY.
above all, he is named as the discoverer of gunpowder, a material which
has wrought more wonderful changes in the great family of man than
the most potent elixir that could have been devised to prolong life.
It seems very strange that a man like Roger Bacon, possessing such
great and original powers of mind, should have been endowed with the
somewhat grovelling notion of making gold; he might certainly have
had the benefit of a doubt in this respect, if he had not left written
statements of his belief in the possibility of transmutation.
In one
(C
رو
of his works called the "Mirror of Alchemy" he thus defines the art:
Wherefore, Alchymie is the Art or Science teaching how to make or
generate a certain kind of medicine which is called the Elixir, and which,
being projected upon metals or imperfect bodies, by thoroughly tinging and
fixing them, perfects them in the highest degree, even in the very moment of
Projection. Again, in the 53rd chapter, where he speaks of the
"Natural Principles and Generation of Metals and Minerals." III.
"For, according to the Purity or Impurity of the said two, to wit, of
Argent Vive, and Sulphur, pure and impure metals are generated, to
vit, Gold, Silver, Tin, Lead, Copper, Iron; concerning the values of
which-viz., of their purities and impurities, or superfluous corruption
and defect, we have a few true things to say."
It is Geber's old idea of mercury, sulphur, and arsenic wrongly in-
terpreted. With the single exception of his belief in transmutation,
Roger Bacon stands out in all other respects as one of the most learned
and original philosophers who have ever attempted to study nature's
laws, and the great historian Hallam awards him very high rank, and
even suggests, from the examination and comparison of Roger Bacon's
Opus Major" with the "Novum Organon " of Francis Lord Bacon,
that the latter condescended to borrow a few notions from the worthy
friar. We now pass to the fourteenth and fifteenth centuries, and the first
name handed down by tradition as that of a successful alchemist is that of
Nicholas Flammel, who was born at Pontoise about 1350, and having
no property, he came to Paris to practise as a scribe, having received å
fair education and being a good penman and well skilled in the learned
languages. Although it appears he soon obtained employment as a
scribe, the profit from his calling was so very small that he could hardly
exist upon it, and, like a clever man, he began to turn his attention to more
profitable work; selecting that which would excite the cupidity and awe
of the ignorant, he commenced with alchemy, and astrology or fortune-
telling. In these occupations he appears to have been very successful,
and soon amassed sufficient money to take a house and marry his beloved
Perrenelle. About this time Nicholas Flammel bought by chance a very
curious old book for two florins, and it became ostensibly the means of
procuring him an enormous fortune, with which, quoting his own words,
as translated from the Latin by William Salmon, he says: "Before the
time wherein I wrote this discourse, which was at the latter end of the
year of our Lord 1413 (after the death of my faithful companion, whose
• Quicksilver.
NICHOLAS FLAMMEL.
133
loss I cannot but lament all the days of my life), she and I had already
founded and endowed with revenues 14 Hospitals, 3 Chappels, and 7
Churches in the city of Paris, all which we had new built from the
ground and enriched with Great Gifts and Revenues, with many Repa-
rations in their Church yards."
•
The discourse alluded to refers to the remarkable book which concealed,
under "Vails, Types, and Hieroglyphic Covertures," the wonderful art
of Transmutation; and it is this work which Flammel is supposed to ex-
plain in Salmon's translation of his "Nicholai Flammel Hieroglyphica
as follows: "I, Nicholas Flammel, Scrivener, living in Paris, anno 1399,
in the Notary Street, near S. James of the Bouchery, though I learned
not much Latin, because of the poorness and meanness of my Parents,
who, notwithstanding, were (by them that envie me most)_accounted
honest and good people
After the decease of my Parents, I,
Nicholas Flammel, got my living by the Art of writing, engrossing in-
ventories, making up accounts, keeping of Books, and the like. In this
course of living there fell by chance into my hands a Guilded Book very
old and large, which cost me only the sum of two Florens [which was
about 6s. 8d. formerly, now 10s. English]. It was not made of Paper
or Parchment, as other Books be, but of admirable Rindes (as it seemed
to me) of young trees. The Cover of it was of Brass; it was well
bound, and graven all over with strange kind of Letters, which I take
to be Greek Characters, or some such like. This I know that I could
not read them, nor were they either Latin or French Letters or Words,
of which I understand something. But as to the matter which was
written within, it was engraven (as I suppose) with an Iron Pencil or
Graver upon the said Barke Leaves; done admirably well, and in fair
and neat Latin Letters, and curiously coloured. Upon the first of
the Leaves was written in, Capital Letters of Gold, Abraham the Jew,
Prince, Priest, Levite, Astrologer, and Philosopher to the Nation of the
Jews dispersed by the Wrath of God in France wisheth health.
دو
After which words it was filled with many execrations and curses,
with this word, MARANATHA (which was oft repeated), against any one
that should look into it, to unfold it, except he were either Priest or
Scribe! Here it may be observed that Flainmel was sorely disconcerted
when he comprehended the dire misery which was to fall upon the rash
peruser of this precious volume, until he recollected that he was a scribe ;
when of course his scruples, with regard to the propriety of reading it,
were satisfied and his fears vanished. He then goes on to say: "In the
second leaf of the book he consolated his nation and gave them pious
counsel . . to flee from idolatry, and to wait in patience for the
coming of the Messiah. In the third leaf, as in all the writing
that followed, he taught them in plain words the transmutation of metals,
to the end that he might help and assist his dispersed people to pay their
tributes to the Roman Emperors, and some other things not needful here
to be repeated. The fourth and fifth leafthereof was without any
writing, but full of fair figures, bright and shining, or, as it were
enlightened, and very exquisitely depicted.
•
•
•
134
ALCHEMY.
"But of the Prima Materia, or first matter or Agent, he spake not
so much as one word; but only he told them that in the fourth and fifth
Leaves he had entirely painted and decyphered it, and depicted or figured
it with admiral Dexterity and Workmanship."
The next chapter of Flammel's book is devoted to the experience of
his sadness and discontent in consequence of being unable to decipher
or read the contents of the book; and after consulting all the wise and
learned men of Paris, he tells us, "they understood thereof no more
than myself. But the greatest part of them made a mock both of me
and that most excellent Secret, except one whose name was Anselme, a
practiser of Physick and a deep student in this Art." This profound
thinker unfolds the First Agent to Flammel, by stating "that this
without doubt was Argent Vive [quicksilver], which they could not fix,
i.e., cut off his feet, or take away his volatility, save by that long diyes-
tion in the pure blood of young infants." A good and humane process,
which Flammel tells us afterwards he accounted Wicked and Villanous,
and never pursued, although he lost one-and-twenty years in a perfect
meander from the verity by reason of the advice given by the deep
student Anselme. "In the end, having lost all hope of ever understand-
ing those Symbols or Figures, I made a Vow to God to demand their
intepretation of some Jewish Priest belonging to some synagogue in
Spain." Accordingly Flammel journeys to Spain, where he makes the
acquaintance of a physician, one M. Canches, a Jew by nativity, but now
a Christian, dwelling at Leon aforesaid. This worthy gentleman was
completely ravished with the copies of the pictures of the book, which
he appeared to have heard of and thought to be utterly lost, and, taking
ship together, they both returned to France; where, as Flammel says,
"he most truly interpretated unto me the greatest part of my Figures,
in which, even to the points and pricks, he could decipher Great Mys-
teries which were admirable to me. Unhappily the good Canches dies
suddenly at Orleans, where Flammel, always affecting poverty, says, “I
hurried him (as well as my present condition would permit me)." He
then returned to Paris to the great joy of Perrenelle; and having now
the "Prima Materia," and devoting three years more to study, search,
and labour, at length Flammel says: "I found that which I desired,
which I also knew by the scent and odor thereof. Having this, I easily
accomplished the Magistery. For, knowing the proportions of the prime
agents, and then litterally following the directions in my book, I could
not then miss the Work, if I would."
رو
(C
On the 17th January, 1382, about noon, being Monday, Perrenelle only
being present, he made a projection upon a pound and a half of mercury,
which he turned into Pure Silver, "better [says Flammel] than that of
the mine, as I proved by assaying of it myself, and also causing others
to assay it for me many times.' Again following exactly the direc-
tions in my Book literally and word by word, I made projection of the Red
Stone, on the like quantity of Mercury, Perrenelle only being present,
and in the same house; which was done in the same Year of Our Lord,
viz., 1382, April 25, at five in the afternoon. This Mercury I truly
NICHOLAS FLAMMEL.
135
transmuted into almost as much Gold, much better indeed than common
Gold, more soft also and more pliable."
Flammel then raises a doubt about his wife's capability of retaining
the secret, only the more to praise and commend her in the succeeding
paragraph as a wise and discreet woman; and he remarks: "Above all
she was exceedingly religious and devout; and, therefore, seeing herself
without hope of children and now well stricken in years, she made it
her business, as I did, to think of God, and to give ourselves to the
work of Charity and Mercy;" and then Flammel gives that passage
referring to the building of the hospitals, chapels, and churches already
quoted at p. 132. Nicholas Flammel was celebrated for his Hiero-
glyphics which he caused to be placed in the churchyard of the Inno-
cents, in the fourth arch entering by the great gate of Dennis Street, on
the right hand. Alleged copies of these pictures adorn Salmon's trans-
lation of "Flammel," and will remind the reader of those precious works

HO
me veniec ad Iudicium del
(vere illa dies terribilis.
chap. 30.
sect.1. Lc.
O Jesu bone
•
11:6.3.
ch.27.
¡sect. o .10.
o-rex sempitern"
Nicholas Flammel. Perrenelle his wife.
ຫານ ການ
ཏུ་
116.3.
ch. 17.
sect 12.12
ch 27
sect.11.
ch 23
sect. I.
lib
"
lib.3 ch.27
sect.13.15
chap. 31.
sect &c
Fig. 82. Illustrations of Nicholas Flammel's Hieroglyphics, which admit, according to
Salmon, of theological and philosophical interpretations. Chapter 27 in Salmon's work
refers to the theological interpretation; Chapters 30, 31, and 32, to the philosophical.
1.36
ALCHEMY.
!
of art to be discovered in Moore's Almanac and other edifying books of
Fate, &c.
There can be no doubt that Nicholas Flammel practised alchemy, and
died very rich; but those of his contemporaries who took the trouble
to look carefully into the source of his wealth, affirm that he did not
make his money literally by transmutation, but was a miser and usurer,
and received, in the first place, great profits from his Jewish brethren
when he visited Spain, apparently to obtain an interpretation of the
book, but really to collect debts and settle accounts between the Jews
living in France and Spain. Had it been known that Flammel was a
collector of money, he might probably never have lived to return to
France, but would most likely have been murdered for the sake of the
property he carried about him. With the excuse of his well-planned
story and apparent poverty he carried about his person documents,
and, no doubt, jewels of great value, which, in the then unsafe condi-
tion of the public high roads, could not otherwise have been transported
from one country to the other. After Flammel came George Ripley,
Basil Valentine, Bernard de Treves, the Abbot Trithemius, the Marechal
de Rays. This miserable wretch is supposed to have murdered at
least one hundred children, of both sexes, at his castle of Champtocé,
in those horrible mysteries which he believed would give him the philo-
sopher's stone. He was finally arrested, and condemned to be burnt
alive; the sentence, however, was modified in consequence of his high
rank, and he was first strangled, then thrown into the fire, and his half-
burnt body handed over to his relatives for sepulture. This nobleman, no
doubt, was insane, and in modern times would have become the innate
of a maison de santé. In the year 1404, and in the reign of King Henry
the Fourth of England, an act was passed in order to restrain in some
degree the knavery and trickery which abounded amongst professors of
the art of alchemy. Even oculists will admit that there is no passion
which so effectually blinds its votaries as that of avarice; and during
the fifteenth and seventeenth centuries every clever trick that the inge-
nuity of man could devise was practised for the purpose of simulating
the transmutation of the base metals into gold and silver. Numbers
of books were written alleged to be translations of the works of
Hermes, Geber, Roger Bacon, and other great men, who would have
blushed that such nonsense should be imputed to them; and even when
the commonest things were mentioned, they were concealed by ana-
grams or put into the most fantastic diagrams like the next cut (Fig. 83),
which is taken from the "Theatrum Chemicum Britannicum," by Elias
Ashmole. This picture is supposed to be explained in the following
verses belonging to "Ripley's Scroule" :-
On the Ground there is a Hill,
Also a Serpent within a Well:
His Tayle is long, with wings wide,
All ready to fly on every side,
Repaire the well round aboute,
That the Serpent pas not out;
THE PICTURE-WRITING OF THE ALCHEMISTS.
For if that he be there agone,
Thou loosest the vertue of the Stone.
What is the Grounde thou may'st know heere,
And also the Well that is so cleere:
And eke the serpent with his Tayle,
Or else the worke shall little availe.
The Well must brenne in Water cleare.
Take good heede for this thy Fyre,
The Fire with Water brent shall be,
And Water with Fire flush shall be;
The Earth on Fire shall be put,
And Water with Fire shall be knit;
Thus ye shall go to Putrifaccion.
And bring the Serpent to redaction.
First he shall be Black as any Crow,
And doune in his Den shall lye full lowe;
I swel'd as a Toade that lyeth on ground,
Brust with bladders sitting 80 rounde,
They shall to brast and lye full plaine,
And thus with craft the Serpent is slainc.
He shall show Collours there many a one,
And tourne as White as wil be the bone.
With the Water that he was in
Wash him cleane from his sin;
And let him drinke a litle and a lite,
And that shall make him faire and white;
The which Whitenes is ever abiding,
Lo here is the very full finishing;
Of the White Stone and the Red,
Loe here is the true deed.
137

10
Fig. 83. The Illustration to the Alchemical Verses.
In these verses it would appear that ground means the earth, on or
out of which proceeds a hill, probably Nitre or Saltpetre. This yields
the Serpent or Aqua Fortis (Nitric Acid). The latter acid is often con-
founded in the alchemist's nomenclature with Nitre, sometimes termed
the Dragon, a Venomous Worm, a Scorpion_devouring his children,
whilst Aqua Fortis is distinctly spoken of as Heaven, Dew of Heaven,
Celestial Water, Celestial Rain, May Dew, Water of Paradise, Parting
138
ALCHEMY.
Water, Aqua Regis, a Corrosive Sublimate, Sharp Vinegar, Brandy,
Viridescent Water, Leo Viridis (the Green Lion), Blood, Milk, a Fiery-
burning Spirit, a Deadly Poison and Basilisk, a Vulture, the Bird of
Hermes, and alluded to by many other absurd names.
The "Well that is so cleere" means some glass vessel; it must "brenne"
or "heat in water cleare," i.e., it must be placed in a water bath, of which
the alchemists make frequent mention, and depict over and over again
in their works on alchemy. By the aid of the serpent "ye shall go to

་་་་་་
כ ס .
ANKLEINA
Fig. 84. The Water-bath containing Alembics, which are connected with
Receivers for the Distillation of Aqua Fortis.
Putrefaccion," i. e., Silver and Gold may be attacked by the double-
headed serpent, or Aqua Regia, from which the White Stone, probably
Chloride of Silver, and the Red Stone, Chloride of Gold, would be pro-
curable. The Silver is represented by the Moon, whilst Gold is shown
by the Sun, so that these verses and the picture (Fig. 83) merely allude
to the effect of Aqua Regia upon the precious metals gold and silver.
Having sufficiently illustrated the jargon of the alchemists, we may
now explain how they apparently performed transmutation.
During the sixteenth and seventeenth centuries the practice of al-
chemy had risen to the highest pitch, and men of learning, princes, and
even kings, whose education should have taught them better things,
were all infatuated with the art from which the ban of Henry the Fourth
had been partly removed by an act of the imbecile Henry the Sixth,
from whom letters patent were granted to several persons, by which
they were permitted to investigate a universal medicine, and to per-
THE TRICKS OF THE ALCHEMISTS.
139
form the transmutation of metals into real gold and silver, with a non
obstante of the previous statute, which remained in full force till the
year 1689, when the famous Robert Boyle by his interest succeeded in
obtaining its repeal, because the act was supposed to operate to the
discouragement of the melting and refining of metals.
At the time that alchemy flourished as a thriving trade, nothing was
more common than to find men in the garb of beggars who professed to
be alchemists. Such persons made their way through the towns and
villages, and quietly eased their avaricious dupes of all they could
squeeze out of them, the victims generally being ashamed to complain
openly of their losses, fearing the ridicule of their fellow-townsmen.
Had all men possessed the discernment of Pope Julian, the pretended
alchemists would have had but a sorry trade. When the Pope was can-
vassed by some fellow who undertook to make his fortunes by transmu-
tation, if supplied with a little ready money to go on with, his Holiness
presented him with an empty purse, remarking that of course the possessor
of the secret could easily fill it. Sometimes an apparently rusty old
iron nail and a bottle of wonderful elixir would be displayed; a few
cabalistic high-sounding words were solemnly uttered, the nail was
stirred in the elixir, and now gold flashes on the eyes of the delighted
and credulous beholders! The nail is handed round for inspection, and
it
hvp
W
HAR
Fig. 85. The Nail, the Dagger, and Coin used by pretended Alchemists.
}



140
ALCHEMY.
found to be cnanged to gold where it had been immersed in the elixir;
but of course the small quantity of fluid in the hands of the alchemist
had lost its power. Some more could be made, and money was neces-
sary to buy the apparatus and chemicals. When these funds were pro-
vided, the impostor decamped, taking with him his prepared nail, half
iron and half gold, the whole being painted to represent common iron, so
that when the nail was stirred in the elixir (i.e. water) the liquid removed
the outer covering of paint, and the gold appeared. It is really sur-
prising that men could be found sufficiently bold to attempt the trick,
or others dull enough to believe in it; but there is evidence of such nails
being used, and one is still preserved in a cabinet of curiosities belong-
ing to the "Grand Duke of Tuscany." A monk presented a dagger of a
similar construction to Queen Elizabeth of England, the blade of which
was half gold and half steel, and alleged to have been produced by
transmutation. Coins, prepared in a similar manner, one face being
made of gold and the other of silver, were also shown to the credulous
as proofs of the art. (Fig. 85.)
Another simple mode of conjuring, or conveying by sleight-of-hand,
gold or silver into a crucible, called at the time transmutation, was that
of using a hollow rod, which, being previously filled with bits of gold or
silver, and closed at one end with wax, would, of course, deliver the

0:
Fig. 86. The Miraculous Omelette from the Monk's Wand.
THE TRICKS OF THE ALCHEMISTS.
141
same into the crucible, when the heat had melted away the wax. Indeed,
this is perhaps one of the oldest tricks, and finds its parallel in the
pious fraud of the good Spanish monk, who produced an omelette
in a frying pan out of his staff for one of his hungry flock, having
previously conveyed therein the materials usually employed in the pre-
paration of that culinary delicacy.
The best mode of carrying out the deception of "projection" is that
which the dishonest alchemist (pretending to avoid even the appearance
of trickery), might put into the hands of his credulous employer, and
say with apparent frankness and love of fair dealing, "Take my crucible
and make it red-hot; pour in some quicksilver, and then throw on the
powder of projection. I will not stay with you or approach the furnace
whilst the philosopher's stone is being applied; attend to my directions,
and the mercury shall be turned to gold." The willing captive of his own
imagination obeys; the projection is finished; nay, the crucible taken
from the furnace, cooled, and broken, and now the precious morsel falls
out-gold!—yea, pure gold! The deception, however, is soon explained;
a lump of gold is first melted in a crucible, and allowed to cool so as to
take the shape of the bottom of that earthen vessel. This gold is then
transferred to a new crucible, and neatly bedded in and concealed by
clay, with which the whole is more or less plastered. When this pre-
pared crucible is shown in a red-hot state, the interior lining is not de-
tected, and if the clay has been nicely worked and mixed, it will
prevent the mercury which may now be poured in from indurating the
surface of the gold, and also protect it from the action of the sulphur
of the red fire, which, of course, must be the powder of projection;
A
B

G
Fig. 87. & G. Lump of Gold filling the Bottom of the Crucible, ▲ B. The space within the
dotted lines indicates the clay used to conceal the gold in a B.
when this latter has deflagrated, and the whole is left sufficiently long in
the furnace to volatilize the mercury, then the crucible may be taken
142
ALCHEMY.
out, cooled by immersion in water, and broken; and of course, the lump
of gold will fall out. Sometimes they drilled holes in lumps of lead,
into which they poured molten gold; the holes were then stopped with
other bits of lead, and when placed in a crucible and subjected to calcina-
tion and proper treatment on the cupel, the lead was gradually oxidised
and removed, whilst the gold remained. Even the schoolboy's trick of
washing coins with mercury was not thought too shallow for the de-
ception of the uninitiated. A gold coin amalgamated with mercury
looks somewhat like silver, but rings with a deadened sound. The pre-
tended alchemists soon transmuted it back to pure gold by boiling it in
aquafortis, which dissolved the mercury, but did not touch the gold.
The author remembers a case where he was applied to for advice,
after several hundred pounds had been expended on a modern alchemist
who undertook to make gold. Upon examination of one flask alleged
to contain the precious metal in process of manufacture, it proved to be
nothing but fragments of mica in a yellow fluid, and as they were shaken
about, they glittered and looked like gold. After pouring off the fluid,
the white and colourless mica was apparent. Another bottle alleged to
contain the seed of gold, turned out to be partly filled with corrosive
sublimate. Whilst some bits of a crucible containing a few specks of
gold, stated to have been procured by projection, appeared to be the re-
sult of an unsuccessful attempt to fuse together some finely-divided
gold, prepared by precipitating a solution of the chloride of gold with
one of sulphate of iron.
The chief alchemists who distinguished themselves in the sixteenth
and seventeenth centuries were Augurello, Cornelius Agrippa, and
Paracelsus. The latter was undoubtedly a man of genius, but, un-
fortunately, the lustre of his talents was greatly dimmed by the most
outrageous vanity, which displayed itself in empty boasts and bombastic
assertions. We are so accustomed to hear that the lion was as meek as
a lamb, and vice versa, that it becomes an odd coincidence when we find
name and character so nicely corresponding as they did in the case of
Paracelsus, whose true name was Hohenheim, to which were prefixed
the baptismal names of Aureolus Theophrastus Bombastes Paracelsus.
He affirmed that he had learnt the art of transmutation, and was also
possessed of the elixir vitæ, and it is said that he died in consequence
of drinking too freely of this remedy against old age, which proved to
be strong distilled alcohol (Fig. 92); on the other hand, it is asserted
that he died, in a state of abject poverty, in the hospital of the town
of Salzburg, in the year 1541.
After Paracelsus came George Agricola, Denis Zachaire, Dr. Dee, and
Edward Kelly. These two men were certainly curious examples of learning,
enthusiasm, and imposture combined. Kelly appears to have been a
firm believer in alchemy, but an unmitigated scoundrel; whilst Dr. Dee
was half crazed with his belief in alchemy, and also in his crystal of a
convex form, which he alleged had been presented to him by no less a
person than the angel Uriel. Dr. Dee believed in a form of spirit-rap-
ping, or the possibility of communicating with the spirits of the invi-

DR. DEE'S MEDIUM.
143
sible world, and supposed that he had only to look intently into his crystal
to behold those who had been long dead, and to converse with them.
47
Fig. 88. Dr. Dee consulting his Crystal, and Kelly in another part of the room digesting
the pretended revelations as Dr. Dee delivered them.
How he could look into the stone it is impossible to say, considering that
the crystal (so-called), was a polished piece of cannel coal, and is thus de-
scribed in the supplement to Granger's "Biographical History." "The
black stone into which Dee used to call his spirits was in the collection of
the Earls of Peterborough, from whence it came to Lady Elizabeth Ger-
maine. It was next the property of the late Duke of Argyle, and is now Mr.
Walpole's." It appears upon examination to be nothing more than a
polished piece of cannel coal. In Mr. George Robins' catalogue, 1842,
of the contents of Strawberry Hill, collected by Horace Walpole, we
find the following puff:-
"One glance must be allowed at the little glass case in the corner,
which is filled with curiosities. Here is the wondrous speculum of the
renowned Dr. Dee-the mirror which
Kelly did all his feats upon.
A piece of highly-polished cannel coal of a circular form with a handle
to it. It is a very mysterious-looking object, and worthy of being
called The Devil's looking-glass.'

144
ALCHEMY.
Fig. 89. Strawberry Hill.
Elias Ashmole, in his notes to the "Theatrum Chemicum Britanni-
cum," states, "It is generally reported that Dr. Dee and Sir Edward
Kelly were so strangely fortunate, as to finde a very large quantity of
the elixir in some part of the Ruines of Glastonbury Abbey, which was
so incredibly Rich in vertue (being one upon 272,330), that they lost
much in making Projection by way of Trial, before they found out the
true height of the Medicine." Ashmole may well say strangely fortunate;
and he might have added, but unfortunate in the end, for Kelly died
whilst endeavouring to escape from a prison in Germany, and Dr. Dee
died in 1608, at Mortlake, almost in absolute penury. The nativity of
Kelly cast by Dr. Dee is still extant. The document is quoted by
Ashmole, and it very much resembles the scrolls which were displayed
to the ignorant by the swindling alchemists of the period as proofs of
their knowledge of the art of transmutation.
The reason these two swindlers selected Glastonbury Abbey as the
place where they pretended to have discovered the elixir was on account
of the legend of St. Dunstan, who was born at Glastonbury; he became
abbot, and died Archbishop of Canterbury, A.D. 988. "The legend of
St. Dunstan," says Hone, "relates many miracles of him, the most
popular of which is to this effect: that the abbot, as the fact really

THE LEGEND OF ST. DUNSTAN.
145
was, became expert in goldsmith's work; it then gives us a story that,
while he was busy in making a chalice, the devil annoyed him by his
personal appearance, and tempted him; whereupon St. Dunstan sud-
ww
Fig. 90. The Legend of St. Dunstan.
denly seized the fiend by the nose with a pair of iron tongs burning
hot, and so held him, while he roared and cried till the night was far
spent."
On examining nearly all the stories of alleged transmutation, it
will be found that the pretended alchemist never repeated projection
more than once or twice, either because all his gold dust was gone, or
from fear of detection, and that he invariably disappeared soon after the
trick had been performed.
L
146
ALCHEMY
When Dr. Dee and Kelly had ceased to astonish the world, Alexander
Seton (supposed to have been the author who wrote under the name of
the Cosmopolite) became celebrated. After the death of Seton, Michael
Sendivogius, The Rosicrucians, Jacob Böhmen, Peter Mormius, Joseph
Francis Borri, who died in the year 1695, made themselves names as
remarkable alchemists; but a new light was gradually coming into the
minds of the honest alchemists, the printing press had distributed some
considerable knowledge throughout Europe, the mysteries and fanciful
ideas of the believers in transmutation were giving way to the realities
and ingenious experiments of the real working philosophers. In
England, Hooke, Mayow, Boyle, Hales, and Sir Isaac Newton had made
their names illustrious. In Paris Le Fèbre and Lemery were working
zealously at chemical, not alchemical experiments. In the Netherlands
and Germany, Van Helmont, Kircher, Boerhaave, Beccher, Stahl, and
Glauber made many interesting discoveries in physics and chemistry.
re
The last of the alchemists were Helvetius, Jean Delisle, Albert
Aluys, the Count de St. Germain, and the arch-quack Cagliostro, who
died in the year 1790, a prisoner in the Castle of St. Angelo.
"The
Chemist" states that, even as late as the year 1784, Dr. Price, the
author of a History of Cornwall,' a physician and a member of the
Royal Society, publicly proclaimed that he could make gold, and had
made it in the presence of several persons; he even presented some of it
to the King. The Royal Society, however, empowered the celebrated
chemist, Mr. Kirwan, and the alchemist Woolfe to examine into the
pretensions of the doctor, and he was obliged to submit to the trial.
He first of all excused himself by saying he had employed all the powder
in the first attempt, but was compelled by reproaches to begin the task.
In this stage his art forsook him; with anxiety he endeavoured to con-
vert mercury, by means of phosphoric acid, into silver; he performed
experiments which consisted in treating arsenic with volatile alkali, and
what is called the Constantine experiment. All failed, and he was
called on to make some more of his powder. After an uninterrupted
labour of six weeks, he made his will, distilled for himself a pint of
laurel-water, drank it, and died in half an hour, at the age of twenty-
six, a martyr to a delusion that, even were it realized, would have no
value, nor be of any utility. He was a man of great talents, but of
greater ambition, and aimed at the reputation of being the greatest
genius of the age. He was possessed of considerable property, but
wrecked his happiness and lost his life by being so credulous as to
believe the assertions of the alchemists."
Whilst alchemy was slowly passing away, and chemistry taking its
place, the transition state was plainly evident in the books of some of
the most industrious workers in the laboratory. This intermediate state
of the science is very evident in the works of the celebrated Glauber,
who discovered the process of procuring vinegar, or acetic acid, by the
destructive distillation of wood; also the method of procuring the
spirit of salt, muriatic or hydrochloric acid from the distillation
of common salt and oil of vitriol; likewise the preparation from the
THE DECLINE OF ALCHEMY.
147
caput mortuum (or residue, after the muriatic acid was distilled off) of
the sal mirabile, or Glauber's salt, now more correctly termed sulphate

KAMINUCHINTA
D
E
བས 1.:
D
TAMI
Galin
JUMAN
Fig. 91. Glauber's Method of procuring Acetic Acid by the destructive Distillation of
Wood, copied from his "Miraculum Mundi." "A is the Furnace or oven, wherein the wood
is char'd, B. The Cover of the Furnace. c. The door at which the coals are taken out.
D. The Canes or Pipes wherein the sap or juice of the wood is condensed, and from thence
runs into the receiver. B is the vessell or receiver into which the vinegar of wood runs."
of soda. Glauber also discovered that a volatile alkali could be obtained
by the distillation of bones, and that, by admixture with his spirit of
salt, sal ammoniac was procurable; he also distilled sulphate of ammonia
with common salt, and obtained common sal ammoniac. These im-
portant discoveries show that Glauber was something more than a mere
alchemist, and his large work, containing "Great Variety of Choice
Secrets in Medicine and Alchymy in the Working of Metallick Mines
and the Separation of Metals; also Various Cheap and Easie_Ways of
Making Salt Petre, and Improving of Barren Lauds and the Fruits of
the Earth; together with many other things profitable for all Lovers of
Art and Industry. Translated into English, and published for Publick
Good by the Labour, Cure, and Charge of Christopher Packe, Philo-
chymico-Medicus," date 1689, is well worthy of inspection; and, though
encumbered with several ridiculous processes for making gold, still
contains many important recipes, from which we make an extract :-
L 2
148
CHEMISTRY.
"Cabinet-makers may strike an excellent Black upon Pear-tree,
Cherry-tree, Box, Walnut-tree, and other hard Woods, which may be used
for curious work instead of Ebony. Skinners or Furriers may dye their
Ermines, Fox-skins, Wolf-skins, and the like Furs with a scarlet, crimson,
or deep black colour, far exceeding the natural. In like manner, Feather-
dyers may swiftly give any lasting colour to their plumes. If an Aqua-
fortis be distilled from Niter and Vitriol, and a little Silver dissolved
in it, and Rain water poured thereon (for the weakening of the Aqua-
fortis), then not only all hard woods are blackened by it, so that they
represent Ebony, but also skins and feathers are made black as a coal,
a ground being first laid upon the feathers, skins, or woods, that the
colours may remain and endure frm."
If Glauber had only applied his solution of nitrate of silver as a
"hair-dye," he would doubtless have realized a large sum of money;
and long after his time, and at least two hundred years subsequently,
photography has almost entirely usurped the use and application of
nitrate of silver in the arts.
r
The latter part of the eighteenth century is remarkable for the
brilliancy of the talents of those who made the science of chemistry
their study. On the 1st of August, 1774, Dr. Priestley made the dis-
covery of a new air derived from red precipitate, a red oxide of mercury;
the same metallic compound which Prince Geber had discovered cen-
turies before, and called the calx of mercury. In accordance with the
Phlogistic theory of Stahl, Priestley called the new air "Dephlogisticated
air," it was not, however, the first gas discovered, because Priestley had
already made himself acquainted with the properties of nitrous oxide, or
laughing-gas; Dr. Black had likewise discovered the properties of car-
bonic acid or fixed air;" and the peculiarities of "inflammable air," or
hydrogen, had long been known, and first accurately described by
Cavendish in the year 1766. Still oxygen was the starting-point, the
basis of an entire new system of chemistry; and as this discovery of
Priestley was followed up by the original experiments of Cavendish and
Watt, and the discovery of the chemical composition of water, the key
was inserted into the lock which had so long excluded the philosophers
from the abode of Truth; and the nature of air and water being once
understood, experiment, reason, and analogy have done the rest, and in
about ninety years brought the science of chemistry to its present
wonderful development. Black, Cavendish, Watt, Priestley, Bergman,
Scheele, were the celebrities who worked in the dawn of chemistry.
"Among the brightest names," says Fownes, "which adorn the annals of
chemical science will ever be placed that of Lavoisier, who at the period
of the discoveries of Priestley and Cavendish pursued his researches in
France. To call Lavoisier the Nestor of chemistry would scarcely be
a profanation of that honoured name. The new facts he actually dis-
covered were not remarkable; it was his surpassing power of generaliza-
tion, his acuteness in distinguishing between the essential and the
accidental phenomena he witnessed, in his careful and happy repetition
of the experiments of others, which distinguished him above all who
LAVOISIER AND DALTON.
149
went before. To point out the elementary nature of the metals, and
show the fallacy of the evidence upon which the opposite view was
founded; to explain clearly the nature of the metallic oxides and the
composition of salts, were indeed great works. The reform of the nomen-
clature was chiefly the work of Lavoisier; and this nomenclature, after
the lapse of more than half a century, is still adequate to the wants of
the science, because its principle is sound and philosophical, and capable
of indefinite expansion. To complete the catalogue of the obligations
we owe to this great man, it may be said that he created the art of
quantitative research. An appeal to the balance was Lavoisier's habi-
tual argument; it was his infallible guide, his just and most faithful
judge.'
>>
How sad to reflect that this great and shining light was quenched in
the horrors of the French Revolution, and that the name of the elegant
and accomplished Lavoisier was inscribed in the fatal list Fermier-
Général, No. 5, and that he perished on the 8th of May, 1794.
Having traced out by rapid steps the rise and fall of alchemy and the
foundation of chemistry, it is impossible, without seriously interfering with
the object of these pages, to pursue the subject further. We may, how-
ever, pay a passing tribute to the names of Wenzel, Richter, Sir Humphry
Davy, Dr. Wollaston, and, above all, to that of Berzelius, whose name we
shall frequently observe to be associated with the metals and their com-
binations. Berzelius has been truly called one of the patriarchs of analy-
tical chemistry. The tables of equivalents, or combining quantities of
matter by weight, which we now possess, have chiefly been the result of
the labours of this great chemist. It is, however, to Dr. Dalton that we
are indebted for the first distinct anticipation, founded on well ascertained
facts, of the general law of multiple combination, and for The Atomic
Theory of the Chemical Constitution of Bodies. As the alchemists desig-
nated their metals by peculiar signs, so Dr. Dalton represented the
elementary substances and chemical combinations by characters which
have not, however, come into use. The system that merely gives the
initials of the elements and the number of their atoms being preferred
from its extreme simplicity, although Dalton always contended that
his own plan of representing the probable position of the atoms of a
compound was preferable. Taking for granted," remarks Dr. Henry,
"that combination takes place between the atoms of bodies only, Dr.
Dalton has deduced from the relative weights in which bodies unite, the
relative weights of their ultimate particles or atoms. This is all that we
are likely to determine respecting them; for it is not probable that our
knowledge will ever extend beyond the ratios of these weights. When
only one combination of any two elementary bodies exists, Dalton
assumes, unless the contrary can be proved, that its elements are united
atom to atom singly. Combinations of this sort he calls binary. But,
if united compounds can be obtained from the same elements, they com-
bine, he supposes, in proportions expressed by some simple multiple of
the number of atoms. The following table exhibits a view of some of
these combinations according to Dalton's theory:
CC
150
CHEMISTRY.
"1 atom of A+ 1 atom of B = 1 atom of C, binary.
1 atom of A+ 2 atoms of B = 1 atom of D, ternary.
2 atoms of A+ 1 atom of B = 1 atom of E, ternary.
1 atom of A+ 3 atoms of B = 1 atom of F, quaternary.
3 atoms of A+ 1 atom of B = 1 atom of G, quaternary."
The characters Dalton used may be copied from one of his own dia-
grams in Dr. Henry's "Life of Dalton," from which we have also taken
the portrait that heads the next chapter. The elements were desig-
nated by special characters, as in the following examples:-



Hydrogen
Carbon
Oxygen
Phosphorus
A Binary compound, such as water
•
A Ternary compound, such as carbonic acid
•
A Quaternary compound, such as sulphuric acid =
Nitrogen
Sulphur
а
ӨӨ
OO
ово
By the system now in use water would be represented briefly by the
letters HO; carbonic acid, CO₂; and sulphuric acid, SO3.
2
With regard to the appreciation of the labours of Dalton by other and
foreign distinguished chemists, the following letter, dated September 20,
1853, from Baron Liebig to Dr. Henry, author of the "Life of Dalton,'
speaks volumes :—
"You wish to have from me my view of the hypothesis of Dalton,
and of its influence on the development of chemistry. This is a difficult
problem; for we, who stand in presence of the science as now con-
stituted, can scarcely conceive how it would have developed itself with-
out this hypothesis. All our ideas are so interwoven with the Daltonic
theory that we cannot transform ourselves into the times when it did
not exist. Dalton's atomic theory was a product of the age, and sprung
forth in his mind as a consequence of the discovery of chemical propor-
tions or equivalents. By means of this theory, the numerical results
were marked with definite representations concerning the internal

Wel
THE ATOMIC THEORY.
151
nature and constitution of chemical combinations; and thus a number
of researches were called forth and prepared for, which had for their
object the relations of physical properties to internal composition. I
need refer only to isomorphism, to the relations of the specific heat, to
the atomic weight, and to those of the boiling point to composition. Che-
mistry received in the atomic theory a fundamental view, which over-
ruled and governed all other theoretical views to which the ideas of the age
respecting chemical forces, affinity, cohesion referred themselves; it was
the bond which bound together all other views. In this lies the extra-
ordinary service which this theory rendered to science, viz., that it sup-
plied a fertile soil for further advancement-a soil which was previously
wanting. In the most recent investigations concerning the constitution
of organic bases, the alcohols and the acids corresponding to the alcohols,
we have seen that the groundwork of the Daltonic theory is equally
valid for organic bodies. His main law that the properties of compounds
are dependent on the nature of their elements, and on the mode and way
of their position or arrangement, will always maintain a high value."
RS
Fig. 92. The Death of Bombastes Paracelsus by drinking Alcohol, being
his alleged Elixir of Life.

Fig. 93. Bust of Dr. Dalton, from the Statue by Chantrey.
CHAPTER III.
THE METALS AND THEIR COMBINATIONS.
It has already been stated in the Introduction to this work that the
thirteen non-metallic elements were considered in a popular manner in
the "Boy's Playbook of Science," and that the pure metals, or metallic
elements, would conclude the description of the whole series of elemen-
tary bodies at present known. The metallic elements are about fifty-
one in number, and their names, discoverers, symbols, and equivalent
numbers are enumerated in the next table.

Name.
Equiva-
lent or
com-
Mo- bining
Names of
eliminators.
1. Aluminium...
2. Antimony
3. Arsenic...
...
4. Barium...
5. Bismuth
6. Cadmium
7. Calcium
*8. Cerium...
...
...
...
...
...
Alumen, alum: Latin, but of
Greek extraction
Anti, against; Monos, one:
Greek words
Arsenicon, potent: Greek
Symbol.
Derivation of name.
An-
cient. dern. weight.
...
...
...
+0
: A
Bi
Ca
...
Ceres, planet so called: Latin
A 2ª Å 2888
Al 13.7
Wöbler.
Sb 129
As
75
Basil, Valentine
Brant, possibly
Ba
69.5
Paracelsus.
Davy.
213
Cd
56
Agricola.
Stromeyer.
20
Ce 47
•
Barus, heavy: Greek
Weiss Muth, white matter:
German
...
Cadmeia, calamine: Greek...
Cala, lime: Latin...
Davy.
Hisinger and
Berzelius.
The names of the metals which are at present unimportant are printed in italics.
TABLE OF METALS.
153

Name.
9. Chromium
10. Cobalt...
11. Copper...
12. Donarium
13. Didymium
14. Erbium
15. Gold
...
***
...
...
...
***
...
16. Glucinum
17. Iron
...
...
...
18. Ilmenium
19. Iridium
20. Lead
...
...
...
21. Lanthanium .
22. Lithium
23. Magnesium..
24. Manganese...
25. Mercury
28. Molybdenum.
27. Nickel...
28. Norium
29. Niobium
30. Osmium
31. Platinum
32. Potassium
33. Palladium
34. Pelopium
35. Rhodium
•
...
...
...
36. Ruthenium …….
37. Silver
38. Sodium
...
***
39. Strontium
40. Tin
...
41. Tantalum, or
Columbium
42. Tellurium
...
43. Terbium
44. Thorium
45. Titanium
46. Tungsten
...
...
...
...
47. Uranium
48. Vanadium
49. Yttrium
50. Zinc
...
...
...
Derivation of name.
Chroma, colour: Greek...
Symbol.
Equiva
lent or
com-
An- Mo- bining
cient. dern. weight.
Kobold, an evil spirit: German K,
Cyprium, cyprus: Latin
Donarium, a gift: Latin
Didumos, twins: Greek
•
...
...
...
Probably from the Hebrew,
signifying to be clear or to
shine
...
Glukos, sweet: Greek ...
Probably from the Hebrew,
signifying to melt
(Its existence denied)
...
...
...
Iris, rainbow: Latin
Molybdos, galena, ore of lead:
Greek
...
0+
: 10
5:
00
Cr
26.7
Co
29.5
Си
31.7
585
:AP
: 8:5
D
50
E
Names of
eliminators.

Vauquelin.
Brandt.
Known to the
ancients.
Mosander.
Mosauder.
ancients.
Wöhler.
ancients.
Hermann.
Tennant.
Au
197
Known to the
Gl
6.9
Fe
28
Known to the
Il
•
Ir
99
Descotils and
Pb
103.7
Known to the
La
47
Li
6.5
Arfwedson.
Mg
12.2
Mn
27.6
...
Hg
100
Mo
46
29.6
...
Lanthano, to conceal: Greek
Lithos, a stone: Greek ...
Magnesia, name of a locality
in Asia Minor
Mangana, in East Indies
Mercury, name of the planet
Molybdos, because mistaken
for lead: Greek ...
Kupfernickel, false copper:
German
...
...
...
Nore, old name of Norway
Niobe, daughter of Tantalus
Osme, odour: Greek
Platina, little silver: Spanish
Pot-ashes...
...
...
Pallas, name of a planet
Pelops, son of Tantalus, sub-
stance so called by Osann
Rodon, a rose: Greek ...
Probably from the Hebrew,
signifying money
...
Salsola, soda, name of a plant
Strontia, place in Scotland...
...
...
***
::
...
...
...
A
Ni
2 = 2 SE
2 2 2 20¤×2 2-2 4 Zãã 88 Ѥ ÞDPHS S
ancients.
Mosander.
Bussy.
Gahn.
Known to the
ancients,
Hielm.
Cronstedt.
H. Rose.
Tennant.
Klaus.
Davy.
...
Nb
99.6
Pt
98.7
Wood.
...
K
39*2
Davy.
Pd
53.3
Wollaston.
H. Rose.
52.2
Wollaston.
52.2
Ag
108.1
Known to the
ancients.
Na
23
Sr
43.8
Davy.
...
...
24 Su
59
Known to the
Та
184
Te
64.2
...
...
Tb
Th
59'6
Ti
25
W
95
60
68.6
Y
32.2
Wöhler.
...
LE Zn
32.6
Paracelsus.
...
...
...
Zr
22.4
Berzelius.
Tantalite, name of a mineral
Tellus, the earth: Latin
Thor, ancient deity
...
...
Titans, mythological deities
Tungsten,
Swedish
heavy
stone:
Uranus, name of a planet
Vanadis, ancient deity....
Ytterby, locality in Sweden...
Zinken, nails: German...
51. Zirconium Zircon, four-cornered: Cey-
...
lonese
...
:::
...
ancients.
Hatchett.
Riechenstein
and Klaproth.
Mosander.
Berzelius.
Gregor and
Klaproth.
De Luyart.
Klaproth.
Sefström.
154
THE PROPERTIES OF THE METALS.
After looking through the table of metals, the inquiring student will
naturally ask what are the properties that distinguish the fifty-one
metals from the thirteen non-metallic bodies? and this question we shall
first endeavour to answer, in order to show why this classification should
be insisted on.
1
In the first place, if we arrange a series of bottles containing speci-
mens of the thirteen non-metallic bodies, we immediately perceive that
three only of them-viz., iodine, silicium, and gas carbon-possess the
power of throwing off or reflecting light, so as to assume that appear-
ance which is correctly designated as metallic lustre. They all reflect
light, but not in the same brilliant degree, as polished gold, silver, cop-
per, zinc, &c. &c. Indeed, there ought to be two kinds of "lustres,"
one might be termed the "mineral" and the other the "metallic" lustre.
The examples of metallic brilliancy are very numerous; thus, a bit of
smooth cannel coal may be covered with leaf-gold which is not more
than the 200000th part of an inch in thickness. If the gold-leaf is
nicely burnished, it imparts an appearance to the coal which might lead
an observer who does not handle the brilliant-looking substance to sup-
pose it may be metallic gold, because coal never possesses a superficial
"metallic lustre." Again, glass reflects light, and when cut in the form
of a prism, and observed in a particular manner at a special angle, it
appears very much like bright shining silver; but glass of any shape
may have a brilliant lustre imparted thereto, by attaching to it either a
metallic amalgam of tin and mercury, such as is used in the manufacture
of looking-glasses, or by precipitating metallic silver from its solution
by the processes of Drayton or Hale Thomson. Salt-cellars and other
vessels made of glass may be easily mistaken for silver ones when pre-
pared by the latter gentleman's complete and perfect process, because
they have metallic lustre arising from the deposit of pure silver. The
metal never changes, being placed just as if it were in a well-
corked or stoppered bottle, and completely out of contact with the air.
A small looking-glass is easily made by laying down a sheet of tinfoil
on a smooth surface, composed of wood, slate, or marble; mercury is
then carefully dropped upon and gently rubbed into and amalgamated
with the tin with some nice soft cotton wool. When the whole surface
of the tinfoil is amalgamated, an excess of clear mercury is poured on
so as to flood the tin foil, where it remains by cohesion, rising like water
from the edge of a glass filled to overflowing. A sheet of perfectly

A
C
Fig. 94. A B. Tinfoil flooded with mercury, and placed on the levelled stand, with a
groove cut round it to catch the excess of mercury. B c. The plate glass held with both
hands by the edges, and carefully slidden over the amalgamated tinfoil.
BC.
METALLIC LUSTRE.
155
clean plate glass is now gently slid over the edge of the amalgamated
tinfoil, so as to remove the excess of mercury and secure contact
between the surface of the glass and amalgam. Great care must be
taken not to push the glass too roughly over the tinfoil and mercury, or
else the latter is liable to crack, and the looking glass is then imperfect.
After the contact has been secured, and all air-bubbles excluded, the
silvered glass may be placed on a smooth surface covered with paper or
cardboard, and pressed with another board on which weights or heavy
books are placed. The excess of mercury is then squeezed out,
and after it has been placed on end so as to allow the remaining mer-
cury to fall towards the lowest point, the amalgam becomes sufficiently
hard, and the looking-glass may be framed. On the large scale, the
table used is made of slate or marble, with a ledge all round, within
which is a groove or channel; it is truly levelled, and rests on an axis
of iron, which runs through the middle of its length, so that by means
of a screw the table can be placed at an angle of twelve or thirteen
degrees, in order to allow the excess of mercury to run off. Of course
great care and skill must be used so as to lay down the separate sheets
of tinfoil side by side, to amalgamate the whole, and then to slide the
great sheet of plate glass gradually over the mercurialized surface.
The plates of glass sometimes break with the pressure required; the
amalgam also will occasionally crystallize, and spoil the reflecting sur-
face; or a drop of mercury will flow down from the top when the glass
plate is put on end to drain, and give rise to curved streaks called
worms," in consequence of small portions of the amalgam being carried
away by the drop of falling mercury. Moreover, the effect of the mer-
cury on the health of the workmen is very prejudicial, producing what
is termed " a fit of the trembles ;" and "if," says a writer in the
Edinburgh Review, the charming belle, as she surveys her beauty in
the glass, could but for a moment see reflected this poor shattered human
creature with trembling muscles, brown visage, and blackened teeth, she
would doubtless start with horror; but as it is, the slaves of luxury and
vanity drop out of life unobserved and uncared for, as the streams of
travellers disappeared one by one through the bridge of Mirza.”
tr
CC
دو
rr
Silvered glass mirrors, in the literal sense of the word, have therefore
been proposed, and the patented processes of Drayton and Thomson
have been worked apparently with little success, in consequence of the
cost and defects of the silvered surfaces as compared with those
prepared with the amalgam of tin and mercury. Drayton's process of
silvering is conducted in the following manner:-A sheet of clean plate
glass is surrounded by a rim of putty, and a thin layer of silvering fluid
poured on. The solution consists of one part of nitrate of silver, to which
enough animonia has been added to precipitate and nearly dissolve the
whole of the oxide of silver. This solution is theu filtered, and if one
ounce of nitrate of silver has been used, three ounces of alcohol con-
taining twenty or thirty drops of oil of Cassia must be added to it,
and the whole shaken together and poured on the surface of the glass,
or the silver solution may be poured on the glass first, and the alcohol
156
THE PROPERTIES OF THE METALS.
1700
and oil of Cassia afterwards. The fewer the drops of oil of Cassia, the
slower and more perfect is the deposit and brilliancy of the silver, of
which from twelve to eighteen grains will cover a square foot of glass,
whilst the value of the silver covering a surface of ten feet by five feet,
varying fromth to 10th of a line in thickness, is stated not to
exceed from seven to ten shillings. Mirrors silvered by the deposit
process are not, however, popular with the manufacturers, because they
become spotted, and present a black aspect which is not considered flat-
tering to the visages of those who have occasion to consult their looking-
glasses. The best way to show the process is to cork one end of a long
clean glass tube, and then to pour in the silvering solution. When the
silvering is complete, pour away the solution, and wash out any
adhering portions of the oil with spirits of wine; drain, dry, and cork the
tube. A number of other deoxidizing agents will answer the same pur-
pose as the oil of Cassia, such as tannin, grape-sugar, &c.
www
The property of opacity is
conjoined to that of metallic
lustre, although gold leaf of the
thickness already alluded to
will transmit a greenish light.

Fig. 95. Red-hot Iron Ball on the palm of the
Hand, protected by some powdered charcoal.
It has been shown that the
metals are remarkable for their
metallic lustre and opacity;
they are also distinguished as
good conductors of heat, whilst
the thirteen non-metallic bodies
are bad conductors. A red-hot
iron ball may be placed for a
short time close to the skin of
the hand, provided a thin film
of charcoal is interposed, be-
cause the latter is a bad con
ductor of heat; but if iron or other metallic filings are substituted for
the charcoal, the effect of the conducting power of the metal is soon
apparent, and the red-hot ball must be quickly removed.
The relation of heat generally to the metals is peculiar and interesting.
The celebrated Dr. Black, in one of his lectures, says, "I therefore con-
sider the metals as substances which have the power to retain strongly
a certain quantity of latent heat, which gives them their toughness and
malleability; but I imagine that heat is driven out of them by the vio-
lent agitation, compression, and friction of their parts in hammering
them strongly into another shape. Those called the more perfect
metals retain this heat with the greatest force, and retain it in some
cases, though extended by skilful hammering to an amazing degree.
Tough iron, which is a purer metal than steel, contains more of it than
steel does, and shows a little more power to retain it; from iron it can-
not be expelled but by the strokes of the hammer, or violent compres-
sion; from steel it can be separated not only by hammering, but also by
LATENT HEAT IN THE METALS.
157
sudden and violent refrigeration of the steel from the red-hot state.
This happens in the operation called the hardening of steel. The steel
is made red hot in the fire, and then suddenly plunged into cold water.
Thus it is made excessively hard, but, at the same time, perfectly
flexible or brittle. We must, therefore, conclude that this sudden
and violent refrigeration prevents its retaining a due portion of latent
heat, which it would have retained, had it been allowed to cool slowly
and quietly. Iron, when treated in the same manner, loses very little
of its latent heat."
The quantity of latent heat in the metals is curiously illustrated by
the flash of faint light which is apparent when a bullet from Perkins's
steam-gun strikes a wrought-iron target. The bullets are completely
flattened, and when directed against a plate of lead placed in front of
the target a "cold weld" takes place, the two surfaces of lead being
firmly united, as if melted or soldered together. The flash of light is
not visible during the daytime, and only in a darkened room. Another
most interesting example of the latent heat retained by metals, and es-
pecially iron, was demonstrated during the trials of Mr. Whitworth's
80-pounder flat-headed hexagonal bolts-we cannot term them balls-
against the resistance offered by the thick iron sides of the floating
battery Trusty. Previous experiments had shown that a single ball
from the smooth bore 68-pounder, or from Armstrong's famous gun,
produced little or no effect upon the plate armour even at a point-blank
range of 200 yards. The plate armour is made of slabs of the finest
wrought iron 4 inches thick, which is backed up and further strength-
ened inside by 22 inches of oak or teak beams laid transversely, and
with half an inch of wrought-iron plate inside them again; but, notwith-
standing the immense resisting power of the iron plates, the hexagona!

Fig. 96. Whitworth Gun and the Iron-plated Floating Battery, the Trusty, showing the
flash of light when the shot struck the side.
158
THE PROPERTIES OF THE METALS.
80-pounder flat-headed bolt, projected from a cannon also made by Mr.
Whitworth, passed completely through them when fired with a charge
of fourteen pounds of powder. The hole it made in the plate was a
clean hexagon, precisely the size of the shot. The shot, when found, was
14
A
B
Fig. 97. The new Electric Lamp, invented by
Hart, of Edinburgh, is represented by the pre-
fixed figure, and consists of ▲ ▲, a moveable brass
rod roughened on the surface like an ordinary
rat-tail file, and holding within its grasp the
upper rod of charcoal, I, which constitutes one
of the electrodes or poles of the galvanic battery.
covered by insulated copper wire, and forming an
electro-magnet when a current of electricity tra-
BB are the two extremities of a soft iron bar
so hot that no one could touch it.
It scarcely showed any sign of
damage beyond being com-
pressed to about an inch shorter.
The fifth shot again pierced
through the centre of a plate
and into the main deck of the
ship, driving before it a mass
of splinters and an immense
iron bolt, which, from the posi-
tion in which it was found-
among the fragments of wood
on the main deck had evi-
dently been dashed through and
whirled about with a force only
inferior to that of the projectile
itself. "It was noticed that, at
the instant of concussion between
this shot and the vessel's side,
a broad sheet of intensely bright
flame was emitted, almost as if
a gun had been fired from the
Trusty in reply.
Metals are likewise excellent
conductors of electricity, whilst
the thirteen non-metallics are
non-conductors, with the excep-
tion of some kinds of carbon,
which, in its purest form-viz.,
the diamond, with a specific
gravity of 3.5 to 3.55-is a non-
conductor of electricity, whilst
in its softer state as in gas car-
bon, specific gravity 1·76, it is
an excellent conductor of elec-
tricity, and is employed as theter-
minals of the copper wires from
the voltaic battery to produce
the electric light (Fig. 97). The
expression of "non-conductor"
is useful to employ in an ele
mentary work like the present;

verses the wire. B is a hollow circular wedge
of a conical shape, divided longitudinally into
halves, which are hinged to a common basement,
and naturally tend to fall outwards. D is a ring
surrounding the hollow wedge E, and attached to
the armature, F, of the electro-magnet. K is a
hollow stem with one arm c, which serves as a
support to the electro-magnet, and a second arm,
H, which acts as a rest for the hollow wedge.
L L are binding screws which connect the wires
of the battery with the lamp. II are the two but must of course be taken in
charcoal pencils which constitute the poles of
the battery, between which the light is produced.
a qualified sense, and should be,
MALLEABILITY AND BRITTLENESS.
159
properly, "bad conductor," as Faraday has shown that good and bad
conductors have certain electrical properties in common, and pass by
insensible gradations one into the other.
One of the most important physical properties of the metals is their
malleability or power of extending, without disintegration, when struck
with the blows of a hammer. The noble metals, gold and silver, enjoy
this property in the highest degree. Ordinary gold leaf is sometimes
beaten so thin that five grains will nearly cover a surface of two square
feet. Pliny informs us that gold was beaten to such a degree of thin-
ness, that one ounce of gold was extended to 750 leaves, each four
inches in size. Lucretius compared the Roman gold leaf to a spider's
web; and Martial described it as little other than a vapour. Pliny also
states that gold leaf was applied to marble with a varnish, and to wood
with a cement called leucophoron. This property of the metals, as
compared with non-metallic substances, is easily shown by casting a bar
of lead, and then having cooled it to a temperature of 32° Fah., it may be
hammered out on the anvil; whilst all the solid non-metallics, if cooled
to the same temperature, in order to be able to include phosphorus, are
brittle, and easily broken up or powdered.
All the metals, however, are not malleable, and
Arsenic
Antimony
Bismuth
Manganese
Molybdenum
Tellurium
Cerium
Chromium
Cobalt
Columbium
Titanium
Tungsten
Uranium
Rhodium
with some others, are specially to be noticed for brittleness, and the
case with which they may be reduced to powder. The malleability and
ductility of metals are strangely altered when they are alloyed together;
if no chemical change or union occurred between them, it might be sup-
posed that the alloy would have the mean malleability of the two metals,
whereas the change of malleability is very curious in some instances.
Thus gold is very properly placed at the head of the list of metals
which enjoy the property of malleability, but if alloyed with lead in the
proportion of half a grain of the latter to one ounce of gold, the whole
becomes quite brittle, and may be easily reduced to powder. It is in
this manner Mr. Denham Smith supposes that Moses reduced the Golden
Calf to powder by first alloying the metal with lead, and it certainly is
a much more probable theory than that proposed many years ago by
Stahl, who gives the Israelites credit for more scientific knowledge than
they probably possessed, and supposes that Moses made sulphuret of
odium, in a solution of which the gold was attacked and dissolved. An
alloy of platinum, copper, and zinc, though remarkably ductile and mal-
leable, is rendered brittle by a quantity of iron not exceeding half a
grain in four ounces of the alloy. Dr. Henry remarks "that in such
cases it has been supposed that a true chemical union does not take
160
THE PROPERTIES OF THE METALS.
""
place, and that the newly-added metal is merely mechanically interposed
between the particles of the other, the cohesion of which it thus im-
pairs.' This explanation, however, can scarcely be admitted as satis-
factory; and among other arguments in proof of the existence of che-
mical union, it may be remarked that gold is rendered brittle by being
kept in fusion in the vicinity of melted tin, the vapour of which it
seems capable of attracting. Mercury, again, renders various metals
extremely brittle, whilst the addition of a very small quantity of sodium
to mercury will render it solid, brittle, and crystalline; hence it may
be asked why the metals have, in some cases, a greater tendency to
crystallize when alloyed with others? does the addition of the foreign
metal, such as lead, act as a nucleus around which the particles of the
gold crystallize in cooling? A great deal has yet to be ascertained by
experiment before we can make the assertion that an alloy is not a
chemical combination.

Fig. 98. Illustrations of the Malleability and Ductility of the Metals.
Ductility is quite the twin brother to malleability, and those metals
which enjoy the latter property are also remarkable for the possession of
the former. Metals are said to be ductile when they can be drawn into
thin wire by pulling a circular rod of metal through a steel plate per-
forated with a succession of holes gradually reduced in size (Fig. 98).
The ductility of gold is amazing, and Dr. Halley states that six feet in
length of the finest gilt wire, used for lace, brocades, &c., before flat-
tening, will counterpoise no more than one grain, and as the gold is not
quite th of the whole, a single grain of gold thus extended will be
345 6 feet long. In India the art of drawing gold and silver wire has
attained the greatest perfection, and the gold-embroidered housings of the
elephant and howdah (Fig. 99) as exhibited by her Majesty in the First
Exhibition in Hyde Park, were remarkable examples of the use of gold
thread, i.e., silver coated with gold. The Mohammedans of Dacca are
67
THE DUCTILITY OF THE METALS.
161
specially remarkable for the Cashmere shawls, scarfs, muslins, and net
fabrics which they embroider with silk, gold, and silver thread.

Fig. 99. Embroidered Housings and Trappings of the Elephant and Howaah exhibited
by her Majesty in the Great Exhibition, 1851.
Although iron is so tough and hard, it may be drawn into wire as thin
as hair, and Dr. Wollaston, by an ingenious modification of the process
of gold wire-drawing-viz., by surrounding the gold with silver, and
M
162
THE PROPERTIES OF THE METALS.
then dissolving off the latter with nitric acid after the drawing, was
enabled to extend one grain of gold to 700 feet. When weights are
applied to different metallic wires of the same gauge or diameter, they
are found to differ very much from each other in their power of sustain-
ing them. This is called the property of tenacity, or power of resisting
a strain. Guyton Morveau has carefully determined the weights which
can be supported by wires of a uniform diameter of 0.787 of an English
line, without fracture.
A wire of iron supports 549-250 lbs. avoirdupois.
copper
302.278
وو
platinum
274-320
""
وو
silver
187.137
""
""
>>
gold
150-753
zinc
tin
109.540
""
lead
34.630
27.621
وو
༤པ
رو
One of the most remarkable illustrations of toughness and tenacity
is exhihited in the Armstrong gun, of which all patriotic Britons are
justly proud. Each gun is made in about three-feet lengths, and on
much the same principle as the twisted gun barrels. Thin bars of the
best wrought iron, about two inches broad, are heated to a white heat,
and in this state twisted and welded together in spiral rolls round a
steel bar or core, smaller in diameter than the bore of the gun. Over
this, when cold, another twist of the same kind is made, with the spiral
running in a contrary direction, and so until three or four layers have
been put on, according to the calibre of the gun and the thickness re-
quired. The whole is then reheated and welded together for the last
time under the steam hammer. The edges of the three-feet lengths
are next planed down so as to admit their joining and lapping over, and
over these edges are forced on thick wrought-iron rings, which, being
welded down at a white heat, of course contract so as to make the joint
almost stronger than if made in one piece. In the breech an opening is
cut down into the chamber; but the breech itself is separate from the gun,
and is worked backwards by a powerful screw.
Unhappy midshipmen, on first joining their ships, are usually favoured
by their more hardened shipmates with all the practical jokes that can
possibly be played off on them in the narrow sphere of a floating ark
and one of the most dangerous is certainly that termed "cutting down,
where the individual in his hammock suddenly gravitates to the hard
deck, in consequence of the supporting ropes being cut away; but if
some tough iron wires were inserted, and concealed in the ropes,
they would still carry the hammock, to the great surprise of those
attempting the mischief.
At the theatre the tenacity of copper wire is frequently tested by
the ascent of witches, fairies, and other prodigies to the dominion of the
carpenters above, termed the "flies." (Fig. 100.)
THE TENACITY OF THE METALS.
163
The standing rigging of ships is now frequently made of iron wire,
and wire ropes are continually used for the purpose of traction, either in
hauling up coals or minerals from the deepest mines, or, as in the case
of the Blackwall Railway some years ago, for dragging the trains back-
wards and forwards between the drums worked by powerful stationary
engines.

Fig. 100. Use of Wire for suspending the Fairies, &c., at the Theatre.
Elasticity is illustrated by the manufacture of iron or steel springs
hardness by the use of steel for cutting tools, or of rhodium for the tips
of everlasting pens, sonorousness by the manufacture of steel and silver
bells, which are all examples of special physical properties belonging
to the metals. Whatever renders metals harder and more elastic
M 2
164
THE PROPERTIES OF THE METALS.
appears to increase their sound-giving power. Another illustration of
the change in the properties of the metals when alloyed together, is

Fig. 101. Spiral of Steel for producing the Sound of a Gong.
demonstrated in the manufacture of bell metal, and copper and tin united
by fusion, are more sonorous than either singly.
Gold and silver would be too soft, and soon wear out, if they were
used for the coinage in a pure state; but the addition of a certain quan-
tity of copper renders them sufficiently hard to sustain the wear and tear
of circulation. By the addition of manganese to steel it retains its cut-
ting edge much longer than ordinary steel, and is therefore employed
in the manufacture of razors and trade tools. The addition of gold is
said to confer even better qualities on the steel than manganese; whilst
tungsten, alloyed with steel, is stated to impart such excessive tough-
ness and hardness, that it may be used for boring through steel.
Amongst the non-metallic elements carbon in the form of the diamond
is remarkable for being the hardest substance in nature; and although
certain individual qualities belonging to the metals may be traced to the
non-metallics, there is not one of them which it would be desirable to
move out of its class. The distinguishing properties belonging to the
metals are not, however, confined to the physical ones of brilliancy,
malleability, ductility, tenacity, hardness, sonorousness, or to the re-
markable power which they possess of conducting heat and elec-
tricity.
:
t
CHEMICAL CHARACTERISTICS OF THE METALS.
165
The metals have peculiar chemical characteristics, viz. :-
A great affinity for oxygen, forming oxides or bases, and acids; also
A great affinity for chlorine, iodine, bromine, fluorine, forming salts.
The thirteen non-metallic bodies, with the exception of fluorine and
hydrogen, form acids when united with oxygen; but then it must be re-
membered that hydrogen has been frequently supposed to be a metal,
and when united with oxygen forms water, which acts like a base or
metallic oxide; for instance, oil of vitriol or sulphuric acid, SO,нО,
consists of dry sulphuric acid, SO3, and one equivalent of water, HO;
but if stated thus it exactly resembles sulphate of soda :-
Hydrated sulphuric acid, or sulphate of water, HO + SO3.
Sulphate of soda.
NaO + SO3.
It will be noticed that in the latter salt the only difference consists
in the substitution of Na, i.e., the metal sodium, for H, the gas hydrogen.
Other examples might be adduced, but would lead us away from the
chief point at present in view, viz., the chemical difference between the
two great classes of elements. With respect to the combination of
chlorine, iodine, bromine, or fluorine with a metal as compared with a
non-metallic element, we may adduce a simple example. Thus, the
metal sodium forms with chlorine a salt termed common salt, or chloride
of sodium, the type of other salts produced by substituting iodine,
bromine, or fluorine for it; hence these four non-metallic elements are
sometimes called halogens, or producers of substances like common salt.
Salts.
Chloride of sodium.
Bromide of sodium.
Iodide of sodium.
Fluoride of sodium.
Now, if oxygen is selected as the non-metallic element to be united
with these, we have numerous acids formed, such as
Chloric acid, ClO5.
Bromic acid, BrO5-
Iodic acid, IO.
Fluorine has not yet been united with oxygen gas.
Or, if carbon is taken as an example of the union of a halogen with a
non-metallic body, we have a series of compounds with a more or less
aromatic odour, such as the
Protochloride of carbon.
Sesquichloride of carbon.
Bichloride of carbon.
Iodine, bromine, and fluorine have not yet been united with carbon.
166
THE PROPERTIES OF THE METALS.
We might pass through the whole series of non-metallic bodies, and
an inquiry into their combination with the four halogens doubtless
affords some apparently contradictory facts, but still the line of demar-
cation is traceable between metallic salts and non-metallic compounds.
A
T
B
Fig. 102. A. The glass vessel containing metallic zinc
and a solution of oxalic acid, with the balls outside.
B. The glass containing oxide of zinc and solution of
Oxalic acid: the heat arising from their union has melted
the grease, and the balls are falling.
The strongest title, how-
ever, a substance can
have to the name of a
metal, is its power of
uniting with oxygen and
forming a base. Before a
metal can unite with an
acid, it must first be oxi-
dized and converted into
a base.
If some zine filings
and oxalic acid are mixed
together and placed in
a glass vessel, to the
outside of which some
large hollow glass beads
or light wooden balls
have been attached by
pomatum, they will not
fall off when water is
added to the contents of
the vessel, because there

is no heat arising from chemical combination to melt the grease; but if
the same arrangement is made in a second glass vessel, and oxide of
zinc, instead of the metal, added to the oxalic acid, then a rapid union
ensues between the acid and base, and the heat produced is indi-
cated by the melting of the pomatum and the fall of the little beads
or balls.
The act of oxidizing a metal is frequently one of the greatest energy,
and usually accompanied with the evolution of much heat. In the
respective chapters on these metals it will be observed that iron, lead,
copper, &c., in a finely-divided state, are actually pyrophoric, and take
fire spontaneously when only brought in contact with the oxygen of
the air.
Correctly speaking, we ought to say, the sulphate of the oxide of
copper, or the sulphate of the oxide of tin; but for the sake of brevity
it is usual to speak of them as the sulphate of copper and the sulphate
of tin. The subject of acids, and bases, and salts is too elaborate a
theme to attempt here, and is better studied in the complete work of
Auguste Laurient, translated by Dr. Odling, and published by the
Cavendish Society; and it is only by reading such a work that we can
form an idea of the difficulties in the way of chemical classification. As
the animal, vegetable, and mineral substances pass by insensible grada-
:
CHEMICAL CHARACTERISTICS OF THE METALS.
167
tions one into the other, so we may readily understand that the like
principle may prevail amongst the non-metallic and metallic elements,
and through them into the myriads of organic and inorganic non-metallic
or metallic compounds.

Fig. 103. Inlaid Vessels and Work in Gold and Silver Filigree from India;
being examples of the great ductility and admirable mechanical qualities of
these two noble metals.

Fig. 104. One of the largest Gold Nuggets yet discovered. From a model
in the possession of Professor Tennant.
BALCOMB.DEL.
CHAPTER IV.
GOLD.
The circle amongst the ancient Egyptians was the symbol of divinity and perfection.
SOME years ago the author remembers being invited by a large
trader in Liverpool to come to his office for the purpose of talking
over the sudden influx of gold from Australia, and its probable
effect upon the value of the precious metal at home; for such was the
general astonishment at the enormous yield of gold, that many serious
thinkers believed that the reign of the sovereign Mammon was over,
and that we must return to the patriarchal possession of land and flocks
of sheep, and herds of cattle, as the only representatives of wealth.
The expected crisis of cheap gold is over, and although 17,023,413 ounces
of gold, value 64,122,3607. sterling, have been exported between May,
1851, and December, 1857, from the two colonies of Victoria and New
South Wales, the expected glut and superabundance of gold coinage
has not yet been experienced in the United Kingdom.
Considering that the Peruvians decorated themselves with the gold
found in their country, and thus excited the cupidity of the cruel
Spaniards, it is remarkable that no gold ornaments should ever have
been alluded to by travellers as worn by the aborigines of the Aus-
tralian colonies. The Peruvians certainly appear to have enjoyed a
much higher grade of civilization than the poor miserable savages of
Australia, and as they erected temples, and were an organized nation
under the government of a king, they would naturally make use of
whatever metallic substances happened to be present in their country.
Unfortunately, their metal happened to be gold, which not only brought
AUSTRALIAN DISCOVERIES.
169
about the destruction of the ancient kingdom of Peru, but sowed the
seeds of avarice and sloth amongst their conquerors, which ultimately
reduced Spain from a first- to a second-class position amongst nations.
It would not be difficult to attempt an analogy between the Great
Britain of the present day and Spain of the ancient time. The latter
had their rich argosies and the most powerful fleet in the world; the
former now possesses those great gifts of Fortune, and is the envy of
the civilized nations. Spain yielded to the luxury and sloth of riches.
England is slightly inclining that way, but her good genius prevails, and
she is still the most industrious, toiling nation on the face of the earth.
Long may Providence decree this state of things! until the colonies
England has founded on the other side of the globe become great and
mighty nations, and reciprocate with filial love the good they have
received from the parent State.
It is truly marvellous that the actual discovery of the treasure
should be deferred till the present moment, in spite of the previous
tenancy of many of the gold-bearing districts by the aborigines and
parties of convicts with their officers. Officers in charge of parties of
convicts were located near the present gold-yielding districts, but
nothing of the kind was heard or talked of during their weary sojourn
there, and a pang of regret must shoot through the minds of those who
had the opportunity and the will to take, but not the knowledge or
powers of observation to find the king of metals when they read the
marvellous tales of Australian riches. Hardened outcasts, wretched
conscience-stricken felons, were neither the men to plan or carry out
discoveries; the highest enjoyment they could hope for was the occasional
temporary insensibility obtainable from fiery rum. Their food was fre-
quently deficient, and "I have known," said a liberated convict, “a man
commit a murder for a meal. I would myself have committed three
murders for a meal." The men who had chiefly sinned to procure gold
were marked, as it were, by being transported to a country where gold
was given away by Dame Nature, but the fact was hidden from their
eyes, and if known at the time, might have caused crimes too dreadful even
to think of every man's hand would have been raised against the other,
insatiable avarice would have caused them to spill each other's blood
like water, whilst the peaceful colonists would have been outnumbered
and destroyed.
In the year 1792 there were only sixty-seven free settlers in New
South Wales; at the present time, in Sydney alone, there are 310,000
souls; 1100 vessels entered the ports of New South Wales during the
year 1857, and these ships were manned by 18,728 sailors. The province
of Victoria in 1858 contained nearly half a million of human beings.
Surely the "good time so long expected has come at last, and there
is now an escape for the poor and industrious mechanic, who may emi-
grate to Australia and obtain for himself and family both work and pay.
It may be presumed that everybody knows that the colonies of Australia
are founded on an island in the South Pacific Ocean, formerly distin-
guished only by the general title of "New Holland ;" a title which has
170
GOLD.
almost (at least in the minds of the public) merged into and been lost
sight of in the glories of Sydney, Victoria, and Melbourne, and spoken
of collectively as Australia.
These colonies are about 16,000 miles away from the sound of Bow
bells, and whilst gold has been found in enormous quantities, and may
be called the staple of New South Wales and the independent province
of Victoria, South Australia is the agricultural colony of Australia, and
exchanges corn and flour for gold dust, although its Burra Burra copper
mines almost equal the gold discoveries in value, as it is said there are
"Hundreds of miles in the northern district which abound in copper of
great purity." The settled districts now occupy as large a space on the
globe as Great Britain, Ireland, and France; and, of the whole continent
of Australia, not more than one-fourth is as yet known.
Western Australia is likely to become the great wool- and tallow- -pro-
ducing portion of this highly-favoured part of the globe.
Having thus briefly alluded to Australia, it must be remembered
that this is not the only gold-producing country. Our worthy cousins,
the Americans, possess California. At the Exhibition of 1851 their
gold services of pure Californian gold were examined with loving eyes
by the multitude who thronged to that palace. A year before the dis-
coveries of the riches of California-viz., in 1846-Sir Roderick Mur-
chison, in speaking of the gold found in the Ural Mountains in Russia,
strongly urged the unemployed Cornish miners to emigrate to New
South Wales, and dig and delve in the débris and drift of what he termed
the Australian Cordilleras; but the lecture-room was 16,000 miles away
from the supposed riches, and the vision of wealth might melt away,
like the ghost, into "Air, thin air," when the miner reached the end of
his long journey; so nobody troubled their heads with what the great
geologist had recommended until 1851, when the startling and agreeable
news arrived from Melbourne, and then a tumultuous rush from the
mother country took place, and the miners no longer wanted to be
advised, but prayed to go.
Gold has not only been found in Australia, California, and the Ural
Mountains in Russia, but likewise in other parts of Europe. Jamieson
states that, "In the time of Queen Elizabeth, extensive workings were
carried on in the district of Leadhills, in Lanarkshire, for the purpose
of collecting gold; and it is reported that 300 men were employed in
searching for it, and that in the course of a few summers a quantity
was collected equal in value to 100,000l." It also occurs in Glen Turret
in Perthshire, in stream works in Cornwall, and in a ferruginous sand
near Arklow, in the county of Wicklow, in Ireland, where a mass
weighing twenty-two ounces, said to be the largest piece hitherto met
with in Europe, was found. The sand of any river is worth washing
for the gold it contains, if it will yield twenty-four grains in a hundred-
weight and provided always that labour is cheap. The sand of the
African rivers often yields sixty-three grains of gold dust in not more than
five pounds weight.
Mr. Evan Hopkins, in speaking from experience, "On the superficial
;
I
¡
!
WASHING SOILS FOR GOLD.
171
appearance of gold producing grounds in Australia," remarks that
"Barrenness, stunted vegetation, broken ridges, and continuous hills of
quartz, clay slate, and ferruginous gravel are the chief characteristics of
gold-bearing rocks. The surface of such formations is not only not avail-
ablefor extensive agricultural operations, but somewhat meagre for pastoral
purposes, owing to the absence of lime in the felspar and the excess of
iron and silica, excepting in the soils of the neighbouring valleys. The
surface of the non-metallic sedimentary rocks, like those in the neighbour-
hood of Melbourne, Geelong, and the western districts near the southern
coast, presents a very different aspect. The primary elements in these
parts of the colony have been more or less dissolved, and deposited in
homogeneous layers in a fit state to nourish the vegetable productions,
and are very different to the coarse ferruginous gravels of the gold fields.
We must be, therefore, very cautious in estimating the value of the
whole surface of the higher parts of the primary rocks for agricultural
purposes. The thickness and quality of the soil, generally speaking,
varies inversely as the richness of the ground is for metals (in situ),
therefore they are seldom found equally productive. I have stated that
the greater portion of Victoria appears to be more or less auriferous
from the Grampians to the Alps, and uncovered by sedimentary rocks
(except in some parts of the flanks), very easily examined, not merely
superficially, but geologically, and it would be for the interest of the
colony to get a survey made as early as possible. This would be the means
of removing many uncertainties, and lead to the early development of the
actual resources of the country and improvement in inland communication."
The sand of the Danube, Rhine, Rhone, Tagus, and many other
European rivers afford gold, and have been at different periods worked
for this metal. The only considerable gold mines of Europe are those
of Hungary.
Sir John Pettus, who wrote an excellent work on Metals," date
1686, says "Gold washers who go abroad in the country for gold wash-
ings, and get their livelihood by it, they have for the gold works a special
proving, whereby they do observe how much gold they wash in one day,
and accordingly make their accounts, whether the work will bear the
charge of washing, and whether it be poor or rich. If, upon search, he
doth find by such proofs that the wash work will recompense his labour,
pains, and charges, then each one, according as he is best instructed,
doth work the same and make his profit thereby, among whom there
are some who do wash that which doth lye in the fields under the mixed
earth, as also the sand out of the flowing Rivers or channels, and do
wash it over a board, in which are cut little gutters and wrinkles, here
and there, into which the heavy gold will descend and remaineth, but
part of it will wash over, especially if the work be rich, and hath grain gold.
"Some years past (and this shows how ancient the process of gold
washing must be) there was found upon such work and sand by the
water-side, a special wash work by which in one day near three hundred-
weight of rubbish have been washed away, and the gold saved, which is
done thus.
172
GOLD.

3
Fig. 105. Ancient Gold Washers (Pettus). "1. The man that worketh with
the Rattar (or shaking sieve). 2. The middle floor, whereon that which
goeth through the Rattar doth fall. 3. The lower floor, whereon that which
cometh from the middle floor doth fall. 4. The plain receiver, called the
hearth, of that which falls from both. 5. The person that stands on a board,
and out of a wheelbarrow throws the matter or oar into the tunnel which
guides it into the Rattar. 6. The channel in which water doth run into the
Rattar."
"Then some of the gold washers use upon their hearths the strong
Timode black and russet woollen cloth, over which they do drive their
works, because the woollen cloth is rough and hairy, so that the small
and round grains of gold will remain and not run forth (as it will from
the Timode), whereby the gold upon the black cloth may apparently be
known, though it may be small and little. Others use, instead of the
Timode, a black woollen cloath Linsey woolsey (half linnen and half woollen,
t
WASHING SOILS FOR GOLD.
173
wrought in the manner as the Timode is), upon which the gold doth
stick better, and such cloths do last longer, because of the Linnen that
is among the Woollen, which doth strengthen it, therefore it is better for
this work.
"But there is another way of washing (not much in use), which is
called Driving and Washing through the long Rattar; but according
to my mind it is not so convenient a way for the small works, which
have great and small gold, and are both sand and clay together, yet I do
not much decline from the before-described Rattar work. For in this
labour or washing, because of the turning in the upper and lower falls,
the running gold is preserved better and the gold goeth with the small
common work over the plain hearth upon which it is driven, and the
manner of doing it is seen in the following sculpture.'
>>
The classical story of Jason and the Golden Fleece has been frequently
suggested to be a fanciful romance, in which is embodied a rude mode of
collecting gold (washed down with the stream), by means of sheep's
fleeces. The fleecing of the King of Colchis probably meant the rob-
bery of the gold he collected in this way from the streams and rivers of
his country. The Pactolus, a small river in Lydia, formerly afforded so
much gold that it is alleged to have been one of the chief sources of
the riches of Cræsus.
The presence of gold in Europe has already been alluded to. There
are few considerable mines of gold worked in Asia; Siberia and Beresof
afford it; likewise the numerous islands in the Indian Ocean, as
Java, Japan, Formosa, Borneo, and the Philippines. In Sumatra many
thousand ounces of gold are collected annually. Africa has long been
celebrated as the land of gold dust, and it is supposed that Ophir, from
which Solomon obtained gold, was a country on the coast of Africa.
America is considered the richest country of the world in gold, and
not only includes Mexico, but California also, the kingdom of Granada in
South America, the Brazils, and other localities. Since the discoveries
of California and Australia, the public mind has become accustomed to
hear of pounds and hundredweights of gold, and although the produce
of this precious metal at the present time most likely transcends that of
all other times, it must be remembered that King Solomon received 666
talents of gold (being more than 27 tons weight) in one year; "and
all King Solomon's drinking vessels were of gold, and all the vessels of
the forest of Lebanon were of pure gold; none were of silver; it was
nothing accounted of in the days of Solomon." (1 Kings, x. 21.) Dio-
dorus says, that the tomb of King Simandius was environed with a
circle of gold 350 cubits about, and a foot and a half thick, and esti-
mating the Roman cubit to be 17.4 inches, it would be easy to calculate
the enormous value of this mass of gold. Semiramis erected in Babylon
three statues of gold, one of which was 40 feet high and weighed a
thousand Babylonian talents. For these statues there was a table or
altar of gold 40 feet long and 12 feet broad, weighing 50 talents.
We have now to ask, in the first place, what are the peculiar charac
teristics of the rocks likely to afford gold?
174
GOLD.
Secondly-Having procured a stone or mineral that looks like gold,
how is it possible to determine whether it is the precious metal or not?
For the ability to answer the first question, we take our information
from nature; because, at greater or less depths, we perceive that the
crust of the globe is not mere loose earth, but is formed of various layers,
or what geologists call strata (from the Latin stratum, a bed). These
layers, strata, or beds, whether hard or soft, are termed collectively
rocks, which admit of a very simple division into stratified and unstra-
tified rocks.
The stratified have all been deposited from water. Hence they are
sometimes called aqueous rocks.
The unstratified, it is supposed, have been once melted by some fer-
vent heat; they have been molten and liquefied like glass in the furnace.
Their other name is consequently igneous (ignis being the Latin for
fire).
The stratified rocks consist chiefly of three kinds of earthy matter-
viz., sand, clay, and lime. The sandy rocks are gritstone, sandstone,
sand, gravel, pudding-stone or conglomerate; the clayey rocks are clay,
clunch, marl, shale, and slate; and the lime rocks are marble, limestone,
chalk. If good examples be wanting of the application of stratified
rocks in London, we may point to the Marble Arch, at one of the en-
trances of Hyde Park, or the buildings faced with Portland stone, or
the New Houses of Parliament. Unstratified or igneous rocks are
lava, basalt, greenstone, and granite, consisting of quartz, felspar, and
mica.
Familiar illustrations can be given of the application of unstratified
rocks by reference to Waterloo Bridge, composed of granite, or to the
magnificent vases of Swedish porphyry exhibited in the Hyde Park
Palace, or the basalt columns of the Giant's Causeway.
The first, viz., the stratified, are deposited in regular order, like the
stones of a mason who erects a column: as the pillar must have a
beginning with the foundation, so with the strata. Common sense will
perceive that the lowest are the first laid down, then a second, followed
by a third. Thus we have the grand division of stratified rocks into
primary, secondary, tertiary, or, in plainer language, into first, seconds,
and thirds, which are again divided into systems and formations. It is
not, of course, supposed that the rocks are to be discovered in regular
sequence and in unbroken layers over the whole globe; but it is satis-
factorily determined that, though the strata are broken or displaced, like
the ruins of an ancient building, the succession can never be inverted.
The foundations of an ancient structure are traced out, and even the
exact position of the inscribed cylinders of Nebuchadnezzar, deposited
two thousand two hundred years ago, can be pointed out by a Sir H. Raw-
linson, whilst the pillars and upper portions of the temple may be in frag-
ments; in fine, the learned observer and student of ancient buildings never
mistakes the upper part of the structure for the lower one, and so it is
with the geological succession. A great number of examples might be
adduced where palæozoic rocks or primary deposits, instead of being in
1
!
!
A FEW WORDS ABOUT THE STRATA.
175
their proper places, "full fathom deep," are the topmost strata, and
stand out on our coasts battling with the winds and waves.
There is a fine example of this nature in the famous "Marsden
Rocks," easily reached from Newcastle by the South Shields line.
Several rooms have been excavated in this rock, and many romantic
associations are connected with it. The mass consists of a succession

Fig. 106. The Marsden Rocks.
of layers of magnesian limestone. Beneath this rock should repose the
speciality of that locality-viz., coal, the "black stones" that Pope
Pius II., in his description of Europe, written about the middle of the
fifteenth century, says he beheld with wonder, given, in Scotland, as
alms to the poor. The carboniferous order being consolidated, another
period, to which no limit can be assigned, seems to have elapsed; after
which, violent disturbing causes, grinding down the chain of mountain
limestone to the west, deposited above the coal measures, in successive
layers, the material of the magnesian limestone. The whole region
traversed by this limestone appears to have been afterwards ravaged
by denuding torrents from the same direction.
The most striking peculiarity of the Marsden Rock is the large and
well-cut bridge which the restless waves have channeled through it.
Magnesian limestone belongs to the paleozoic or primary rocks, and
yet it occurs at the surface of the earth.
These simple facts in geology would not have been mentioned, except
176
GOLD.
to answer a question likely to arise in the unscientific, though other-
wise clever mind-How can geologists say which are the oldest rocks?
or, What do they mean by primaries, secondaries, and palæozoics?*
&c. &c.
The simple classification already mentioned established in the mind,
it is easy to comprehend that, if Ñature be true to herself, she cannot
invert or turn in a contrary direction this arrangement of the stratified
rocks. The primary being first deposited, cannot be found above the
secondary, or the tertiary under the secondary. Pictures in a book help
to instruct both young and old; an imitation of nature, by way of
B
3
2
1
тута
B+ i
1.
Rice.
Fig. 107. Glass Jar standing on a piece of red
calico, A, and containing the three strips of calico
covered with the layers of seeds.
2. Black horsebeans. 3. Haricot beans. B. String
attached to the white calico at the hollow of the jar.
c. String attached to the blue. D. String attached to
the yellow.
pile" in the present generation.
experiment, however rude,
may assist us. Place in a
glass jar strips of white,
blue, and yellow calico, each
with strings attached to one
end, which carry up and lay
over the edge of the glass;
cover these with three layers
of seeds at the bottom rice,
then black horsebeans, lastly
haricot beans. Here we
have primary, secondary,
tertiary. Beneath and out-
side the jar arrange a bit of
red calico, which may be
called the igneous rocks.
Here is a mechanical illus-
tration of the previous facts
stated; but how are we to
know (in nature) primary
from secondary, or the lat-
ter from tertiary ?-By the
remains of animals, fishes,
plants, and shells, called
fossils, deposited by nature
with the strata, like the
bottle holding the coins
placed under the foundation-
stone of many "a goodly

Fossils are well termed "the medals of creation ;" and the gold seeker
would not experience much difficulty in appreciating the fossil remains
of a peculiar fish, now extinct, of the lobster tribe, called, in scientific
language, crustaceous, and known to naturalists as the Trilobite, having
a jointed body ploughed with two long furrows, and thus divided in the
length into three parts (hence the derivation of trilobite, from the Greek
• Palæozoic means characterized by ancient animals.
GOLD-BEARING STRATA.
177
treis, three; lobos, a lobe). Now, this and other very marked fossils
belonging to the older palæozoic rocks, have been stated to be associated
with the precious metal; and gold, like
coal, has natural companions, which enable
the geologist to pronounce with almost
perfect certainty that it may or may not
be found in certain localities.
Our thirst for knowledge will suggest
other pertinent questions-Had not gold
a beginning? or, How is it supposed
to have been formed in the bowels of the
earth?

Fig. 108. Fossil. The Trilobite.
Here we shall allude again to the illustration of the jar and the seeds,
Fig. 107, in explanation of the facts, the more particularly as Mr.
Stuchbery, in his Government report, states "that most of the hills west
of the principal gold diggings are capped with basalt," and basalt is an
igneous or unstratified rock. "I find by observation that the trappean
rocks, such as basalt and porphyry, have arisen to the surface, project-
ing themselves through the schistose rocks, and by overflowing and
after degradation, they give origin to most of the round-topped hills."
Here, again, we find igneous rocks in the neighbourhood of gold; and
Mr. Stuchbery also observes that quartz must be regarded as the chief
matrix or womb of gold.
If igneous rocks were below the unstratified originally, why do they
cap hills at the present time? Here speculation must assist us. It
has been assumed, that after the stratified rocks were deposited, certain
convulsions of nature (which occur even at the present time in the shape
of earthquakes and fiery volcanoes, like those of Etna or Mount Vesu-
vius) took place, by which the melted rocks were actually protruded up-
wards; just as the piece of white calico may be pulled from the bottom of
the seeds in the jar, causing the strata to bend upwards. Let that rude
imitation represent the melted rock, such as granite or basalt, pushed
through the other strata. During this grand operation of nature, the
surrounding strata must crack and leave fissures. Into these places
the melted rock might continue to run; then another interval of time
would elapse-the rocks previously in a state of fusion cool and contract,
leaving other cracks and fissures. In these places or hollows the
metals and minerals are supposed to have been deposited, perhaps by
the same electrical agency through which we obtain a perfect copy of
any medal or cast, by the process of electrotyping. Natural currents of
electricity may have gradually produced the veins of minerals, and thus
originated gold in common with other native metals, found generally
associated with quartz, which latter appears to have been more plen-
tifully deposited than any other mineral substance. Quartz is only
another form of sand, and is an oxide of silicium. Let us, then, pull up
a piece of blue calico from the bottom of the seeds, by the side of the
white, to represent quartz, and also another strip dyed yellow, to represent
the gold, and we have done practically all that can be effected with this
N
178
GOLD.
simple arrangement to give a mechanical notion of the origin of gold. We
have, finally, to imagine the top of the seeds, through which the different
3
B
ศ
2
B
Fig. 109. Glass Jar, same as at Fig. 107. B B. White
calico, pulled up through the three layers of seeds.
cc. Blue ditto. D D. Very thin strip of yellow
calico, to represent the gold. A. Red calico, on
which the jar stands.
coloured calicoes are protrud.
ing, and which we have called
igneous rock, quartz, and gold,
to be washed by water, and
carried off miles away from
the original source. Thus it
is supposed that the rocks
containing gold have been
subjected to the action of
breakers and waves, like our
sea-coasts at the present time.
These waves, gradually reced-
ing or advancing, have carried
off large lumps of the rocks,
and, by rubbing, reduced them
to smaller particles. Hence
we read of gold in the dry
diggings being found in drift,
which is nothing more than
particles of rocks transported
from their original position.
In unison with these observa-
tions, we may again quote Mr.
Stuchbery:-

Nor is it at all surprising
that gold should be so rarely
found in its original gangue
or matrix, as compared with
the large quantity found in the
limited areas of the earth's
surface, if the mind is only
prepared to grasp the immense
amount of disintegration (i.e.,
separation into smaller parts)
and consequent denudation
(washing away so as to lay bare the inferior strata), together with the
lapse of countless ages which may have taken place since the removal of
the first atom to the present time. As a proof of the transporting forces
I may mention, that in the bed of the Summerhill Creek I found rounded
blocks of fossiliferous limestone, which I am convinced must have come from
the mountain range between Summerhill and Emu Swamp, thus traversing
the tortuous course of the creeks, passing over precipitous falls through
deeply-hollowed holes, and other impediments; and yet large portions of
this limestone still remain as evidence of the power of these periodical
mountain torrents. This single instance is sufficient to explain the
abraded, battered, and water-worn character of the gold, and the general
I
COUNTRIES WHERE GOLD IS FOUND.
179
absence of any particle of its original investing but more fragile
matrix.
"In Europe gold occurs in igneous and metamorphic rocks, such as
granite at Gastin in Salzburg, gneiss in Upper Hungary, and mica
slate in Salzburg and Tyrol; in clay porphyry in Transylvania; in horn-
blende rock, along with auriferous iron pyrites; in veins of quartz at
Edelfus, in Sweden.
'In Asia gold occurs in Siberia in veins that traverse hornblende
rock; it is also obtained from veins, where it is associated with quartz
or from alluvial soil, when it occurs in the form of dust or in masses;" also
in the sand of rivers. "In Africa gold is found in the sand of rivers or
the alluvial soils of valleys or plains, and at the foot of those mountain
ranges in which are situated the sources of the rivers Gambia, Senegal,
and Niger."
In America the gold is chiefly collected in alluvial soil in the beds of
rivers, and also from veins. Jamieson, who wrote his work in 1816,
says, "On the coast of California there is a place of fourteen leagues
in extent covered with an alluvial deposit in which lumps of gold are
dispersed." How strange! that above thirty years should be per-
mitted to elapse before the great discoveries of gold were made in this
part of the world!
For the sake of greater simplicity, nothing has yet been said respecting
the metamorphic or transformed rocks, such as green and chiastolite
slate, mica and hornblende schists, porphyry; but it must be evident
that, if great eruptions of melted and red-hot granite, &c., have taken
place from below, they could not pass through stratified rocks without
affecting them to a certain degree, or changing their physical aspects so
as to make them assume the appearance of igneous rocks. Any of the
stratified rocks may be changed to metamorphic ones; but as the pri-
maries are the lowest and nearest to the granite, so the metamorphic
rocks are usually primary rocks, and in a geological chart, such as that
of Mr. John Morris, are placed at the bottom of the paleozoic or primary,
being termed hypozoic or metamorphic rocks.
We have spoken of strata, but not yet afforded the precise clue which
is to guide the gold seeker in his geological opinion of the rocks and
the probable existence of gold in any range of country under examina-
tion.
The following plan, however, may be recommended, founded on a
statement made by Professor Forbes, that "it is useless to waste time
in searching for gold in the older tertiaries, or in secondary rocks, so
far as Australia is concerned; though none of the latter appearing to
be as yet discovered in Australia, the gold seeker is not likely to go
wrong through them.
The older paleozoic, the metamorphic rocks that
lie beneath them, and the newest tertiaries, all taken in connexion with
mountain chains, are the best guides in this matter.”
The author recommends that every emigrant who intends to seek for
gold should purchase a small collection, specially and chiefly arranged
by Mr. Tennant, the eminent mineralogist of the Strand.
N 2
180
GOLD.
The collection may consist of two small deal trays, one containing
fossils of the most decided and ordinary character, belonging to the
older tertiaries and secondary rocks, which are NOT associated with
gold.
The other to contain specimens of the older paleozoic fossils, meta-
morphic rocks, newest tertiary fossils, with a specimen or two of
an igneous rock; all of which are said to be characteristic of the
presence of gold.
1
3
Co

A
C
ليا
4
2
5
6
8
7
B

D


F
Fig. 110. A to B. Australian Fossils of the older Tertiaries. 1. Echinolampas. 2. Spatangus.
3. Terebratula Compta. o to D. Australian Fossils of the Upper Palæozoic or Silurian
Rocks. 4. Spirifer. 5. Productus. 6. Pachydomus.-B to P. Lower, or older Palæozoic
Fossils. 7. Pentamerus, 8. The Trilobite.
STRATA OF THE GOLD DIGGINGS.
181
At the famous Ballarat diggings, the following strata are passed
through to reach the celebrated blue clay (one of the newest tertiaries)
which was found to be so rich in gold.
1. Red ferruginous earth and gravel.
2. Streaked yellowish and red clay.
3. Quartz gravels of moderate size.
4. Large quartz pebbles and boulders; masses of ironstone set in
very compact clay, hard to work.
5. Blue and white clay.
6. Pipe clay.
With a collection of specimens to look at on the voyage, and a month's
practical geologizing at the diggings (i.e., familiarizing the eye with the
earthy companions of gold), the intelligent though ignorant emigrant
may bid defiance to hard geological names, and lead the way, perhaps,
to fresh diggings, thus reaping the first and best harvest of gold in a
new district: as it is evident he does not require a knowledge of geology
to guide him in digging a hole close by the side of others who are
actually finding the precious metal.
Geology is of incalculable value to that man who will venture to lead a
party away from the multitude and search for gold in unexplored districts.

Fig. 111. Australian Gold Diggings.
Having spoken at p. 177 of the eruption of melted rocks, it is
right to bear in mind that many intelligent geologists ignore altogether
the action of fire, and maintain that the gold was entirely deposited by
electro-chemical decomposition. Mr. Evan Hopkins is one of the most
182
GOLD.
determined opponents of the red-hot theories, and he remarks, in his
pamphlet on "The Geology of the Gold-bearing Rocks of the World,"
"When persons see the large masses of gold obtained from the surface
of the quartz, or the edges of the primary slates, they are too apt to
think that such productions are caused by melting or intense heat."
Such ideas, Mr. Hopkins says, are incorrect, and from the circumstance
of the metal being marked with the most minute striæ of the quartz,
which contains the usual proportion of water, he maintains "that this is
a state of things totally inconsistent with an intense melting action, but
identical to that resulting from a battery and an aqueous solution."
In the second division of the subject, the most important question
remains to be answered: "Having obtained a substance which looks
like gold, how are we to be sure that it is or is not the precious
metal ?"
Before treating of the chemistry connected with this part of the
subject, it may be premised that the explorations conducted in the
general drift are termed "dry diggings; "the search after gold in the
bed of a river is called a "wet digging," whilst the operations conducted
by the assistance of machinery in which the quartz containing the gold
is crushed, washed, and amalgamated with quicksilver, may be distin-
guished from the others as quartz-crushing and mining.
The latter plan is now coming steadily into use, although it requires
expensive machinery, a number of hands, and, of course, large capital,
and is a process better worked by a company or association of monied
men. Quartz-crushing is now proved to be very profitable, and a
friend of the author, just returned from Sydney, informed him that he
knew a party of six speculators who had a large tract of ground
assigned by a creek in Australia, where they had erected a 12-horse
power steam-engine, with proper machinery for crushing quartz and the
amalgamation process. This speculation yielded at first 24007. worth
of gold per week, but it has since diminished. They employed thirty
men, and gave wages from 57. to 30s. per week, besides the necessary
rations.
The Melbourne correspondent of the Times of May, 1859, speaking
of quartz crushing, remarks that "The application of capital and costly
machinery to the production of gold, especially to quartz-mining, is
rapidly increasing, and some very rich quartz reefs have been lately
opened. At the Reedy Creek, about twenty miles from Kilmore, and
about fifty from Melbourne, in a rough, hilly country, quartz reefs of a
very rich character abound.
"In some cases the yield has been as high as thirty-one ounces of
gold to the ton of quartz. In some specimens that I have seen the
gold was so minutely distributed through the quartz as to be only here
and there visible, yet the weight of the specimens betrayed their rich-
ness, and they yielded sixteen ounces to the ton. Last month the paper
noticed a lump of amalgamated gold, weighing 730 ounces, as the
largest yet produced; but since then a lump of 1320 ounces has been
obtained from one crushing. It was procured from forty-five tons of
CRUSHING MACHINERY.
183
quartz taken from Iron Bank Gully, at Bendigo. The labouring diggers
now perceive that the old mode of independent digging must in time
wear out, and in many cases they are becoming reconciled to working
for wages.

ส
Fig. 112. A Cornish Crushing Machine worked by a Steam Engine.
The dry diggings are the most generally worked, because nature
has done the work of the steam-engine by crushing and breaking up
the original matrix, and spreading the gold over a large range of
country; we cannot, therefore, fail to notice machines mentioned in
nearly all letters from emigrants, called "cradles," used extensively to
rake or wake up the gold, in contradistinction to the usual office of this
machine, when it contains a living occupant, who is supposed to be sent
to sleep with greater facility by its use.
!
No doubt the original idea of cradles was taken from Nature, as
a hollow tree, cut down and divided in halves, with a few rude
184
GOLD.
partitions, or ribs, at the bottom, would answer the purpose of the
gold-washer.

Fig. 113. Rude Washing Cradle, consisting of the Half of the Trunk of a Hollow Tree.
A little experience only is required to work them properly. Thus
the earth is thrown into the upper sieve with plenty of water; here
the large stones are retained, which are carefully looked over for
gold; then the cradle is kept continually rocked, the motion being
graduated and not too violent; the continual shaking and flowing of
the water washes away the earthy matter, whilst the gold, which is
more than seven times heavier than anything likely to be associated
with it, sinks to the bottom, being retained by the cleets or ribs of wood
put across the lower part of the machine.
Professor Hunt remarks that Herodotus informs us that the people
living near the sources of the Indus obtained a large quantity of gold
from the eastern border of the great Bactriana and the desert steppes
of Cobi. Much was obtained by washing sands, and more by digging
and both Herodotus and Pliny tell us a strange story of gold being
turned up by enormous ants-"not so large as a dog, but bigger than a
fox," and that from these ant-hills the Indians obtained the greatest
quantity which they supplied to the monarchs of Persia. Humboldt
has shown that this story arises from the double meaning of a word.
Herodotus again tells us that "in the north there is a prodigious quan-
tity of gold, but how it is produced I am not able to tell you certainly.
It is affirmed, indeed, that the Arimaspi, a people who have but one eye,
take the gold away by violence from the griffins ;" but, says the father
of history, "I can never persuade myself that there are any men who,
having but one eye, enjoy in all other respects the nature and qualities
of other human beings.
More complicated cradles and machines were made at the time of the
first rush to the "Australian diggings." The cradles had perhaps one
recommendation-viz., that they could be used as clothes-boxes by the
emigrants on board ship, and would serve as models for others; and in
the next cut we give pictures of some of them, the principle upon
which they acted being that of agitating the auriferous earth with water,
GOLD-WASHING MACHINES AND CRADLES.
185
the settlement of the heavy gold to the bottom of the cradle or machine,
whilst the lighter earth was washed away.

2
1
H

3
DIALECE
Fig. 114. No. 1. Barnes' Barrow Gold-washing Machine. No. 2. Dray's Gold-washing
Machine. No. 3. Hill's Gold-washing and Reserving Machine.
Mr. Jukes, speaking of cradles, makes a very appropriate comparison
between them and the beds of rivers. He says, "Rivers are indeed
great natural cradles;' sweeping off the lighter and finer particles at
once, the heavier ones either sticking against natural impediments or
being left wherever the current slackens its force or velocity. A cradle
is a wooden trough with several 'cleets,' or ribs, fastened across its
bottom. Into the head of it is placed a quantity of auriferous sand or
gravel, water is poured over it, and motion communicated by rocking
186
GOLD.
i
and tilting the cradle. The running water carries off all the lighter
matters, and leaves the heavy stones and lumps of gold, either in the
head of the cradle or accumulated at its bottom against the 'cleets,'
fastened across to arrest them. Turning the bed of a river, then,
wherever such a manœuvre is practicable, is like a miner examining the
bottom of his cradle; and if it happens to be done at the right spot
where there are several natural 'cleets,' or bars, or where there are holes
in the rock for the gold to drop into, it is likely to be rewarded very richly
by the accumulated result of centuries of natural gold washings.
"In gold mining vast quantities of hard rock have to be quarried
and removed to be crushed by powerful machinery, and to be washed
over and over again, or to be treated by other expensive processes;
while in gold washing, or separating gold from drift, all the mining and
the crushing, and a good part of the washing and sorting of materials
have been already done for the miner by nature."
A very good machine made by Mr. Barnes consists of a stout
cylindrical vessel of galvanized iron; in the centre is placed a strong
shaft, with iron arms attached; the whole being worked by a set of cogs
and power-wheel. The earth is thrown into the top (where the large
stones are retained by a sieve), with plenty of water; the iron arms are
worked round and round, just as we see in a brick-field the clay and
other materials worked up in a tub with horse-power. At regular in-
tervals from the top are placed little doors with screws, and as the
washing proceeds, the person engaged in using it opens first the top
one, permitting a little of the earth and water to flow into a pan, which
he carefully examines for gold spangles or dust; if no glittering par-
ticles are apparent (and a large magnifying-glass would greatly facilitate
the examination), he passes to the second hole, from that to the third,
thus tracing the gradual descent of the gold, until he arrives at the
bottom of the vessel; here a plate or slide is withdrawn, and the gold
dust, with some earthy matters, falls into the pan. After two or three
iron buckets of the earth, rich in gold, have been collected, the contents
are washed over again in the machine; and it is stated that by this
apparatus one ton of earth (whether sand, clay, or gravel) can be washed
per diem with the assistance of two boys of twelve years of age, or one
able-bodied man.
When the first rush took place to the diggings, men worked singly or
in couples, but the lawlessness and utter recklessness of such a mixed
society soon caused the industrious and peaceful to band together for
the protection of life and property. Parties of six were the usual
number of the joint-stock company, because six were less likely to
quarrel than eight or twelve, and also because they were the smallest
force that could work together. Two of the band worked together,
one in the hole or claim, and the other at the pit's mouth; two guarded
the tent and two slept; those who slept always retired with their re-
volvers ready at hand to use immediately on the slightest alarm being
given. The author was told an authentic story where six men had
banded together as described; but, in consequence of extra work, the
DISCRIMINATION OF GOLD FROM OTHER MINERALS.
(c
187
watching was not complete, one watcher being allowed to sleep whilst
the other tried to keep his eyes open, and singly to guard the united
property. The single watcher had at last yielded to the enticing god;
but the other, who had permission to sleep, by some strange fatality,
felt uneasy, and having some apprehension of being robbed, could not
slumber; suddenly the light, or rather the darkness, from the opening
of the small flap in the tent, passed across his eyes, when he immediately
cried out, "Who's there?" and receiving an answer,
Oh, I beg your
pardon; I've made a mistake," he did not wait for further questioning,
but instantly fired his revolver. The whole party being roused, sallied
out, and found a man shot and lying dead, whose body they thrust into
the open street or lane between the canvas houses; and finding that the
corpse was removed before daybreak, surmised that this man belonged
to a gang of thieves who risked their lives in this way, with the hope of
surprising the toil-worn and sleepy gold-diggers. A friend of the
author told him that he was fairly cleaned out three times by thieves,
who carried off everything during very temporary absences from his
canvas home.
We now pass to the strictly chemical part of the subject, "the dis-
crimination of gold from other metals and minerals."
Our next cut displays a series of mineral specimens, many of which
glitter, and look like gold, suggesting, however, the old caution, that
"all is not gold that glitters.'
There are three specimens, Nos. 1, 2, 3 (Fig. 115), containing only
iron pyrites, or sulphuret of iron.
There is another set of three, Nos. 4, 5, 6 (Fig. 115), containing
copper pyrites, or sulphuret of copper, and carbonate of copper.
All these have a shining aspect, and are frequently mistaken for gold.
But the other three, Nos. 7, 8, 9 (Fig. 115), are very modest-looking
specimens. These have come from California and Australia, and contain
gold, although any one might consider them, by mere inspection, to be
worthless.
In the absence of specimens for comparison, the gold-seeker probably
having none, the most simple modes of ascertaining the difference between
iron or copper pyrites and gold may now be pointed out.

1
The only apparatus required is a common anvil and hammer, and a
red-hot shovel. A piece of gold may be treated most roughly with the
hammer on the anvil: it may be beaten out and extended, thus demon-
strating that it has the property of malleability, which gold enjoys in the
very highest degree, as this metal may be beaten out into leaves the
383000th of an inch in thickness; ie., it would take 282,000 to
make a pile of gold leaves one inch high. One grain also can be made
to cover 56 square inches. We cannot, then, beat the gold to frag-
ments, but may do so with the pyrites; and directly it is struck with
the hammer, sparks of fire are apparent (hence its name, from the Greek,
Tup, fire, as it was employed formerly for striking a light); at the same
moment the mineral is broken to pieces; it is very brittle, and by con-
188
GOLD.
tinuing the hammering may be reduced to powder. In the next place,
the powdered mineral is to be sprinkled on a red-hot shovel, when a blue

2
1
7
5
6
3
Fig. 115. Series of Specimens, from Mr. Tennant's. 1, 2, 3. Specimens of
iron pyrites. 4. Malachite. 5, 6. Copper pyrites. 7, 8, 9. Specimens of
rock containing gold.
flame is apparent, and by smelling the fumes which rise from it, the
odour of burning sulphur is soon detected. It is, perhaps, unnecessary
TESTING FOR GOLD.
189
to remark that gold is incapable of producing any odour or fumes when
thrown upon a red-hot iron.

Fig. 116. Testing for Pyrites by the red-hot Shovel.
These are the simplest tests to distinguish the pyrites minerals from
gold, and we shall speak of the mode of testing yellow mica in another
place: indeed, it may be observed, that there is little danger of the gold-
seeker being deceived by Nature, her ways are so unvarying, plain, and
simple. The emigrant has most to fear from the chicanery of his fellow-
man; and perfect imitations of gold nuggets have made their appearance at
several of the sea-ports, manufactured in the toy-shop of the world;
regular "Brummagem" wares, so well got up as regards weight and
outward appearance (for they were electro-gilt), that many have been
sold as specimens, and of course their chief destination was the dig-
gings—at least it may be supposed so,-because already some parties
sending brass filings from Sydney, under Government escort, and pay-
ing duty, have been detected, and their precious wares confiscated,
whilst their names have been most liberally treated by Government in
the Sydney papers; in fact, they have been deservedly exposed, and lost
nearly all their trade in consequence.
How, then, can gilt brass filings or sham nuggets be distinguished
from the real article?
In the first place, the author recommends every person intending to
trade in this gold to take out three pint bottles of acids; viz., one pint
of nitric acid, commonly called aquafortis; one pint of hydrochloric, or
muriatic acid; one pint of oil of vitriol, or sulphuric acid: these acids
will not cost more than eight shillings, bottles and all, and may be pur-
190
GOLD.
chased of Mr. Thomas, chemist, Pall Mall, London, and their great
value will soon be apparent.
If some glittering copper turnings are placed in a test glass, or wine
or other convenient glass, and some gold leaf in another, on the addition
of aquafortis or nitric acid to both of them, a violent commotion is
visible in the glass containing the copper, and orange-red fumes escape,
which are very disagreeable to the lungs; but the gold remains perfectly
tranquil and undisturbed, and if the nitric acid is pure, they might pro-
bably remain in contact with each other for a century without any action
on the gold taking place. If a similar experiment is made with hydro-
XXX



A
B
C
Fig. 117. A. Copper turnings or sham nugget in nitric acid. B. Glass con-
taining gold leaf and nitric acid. c. Glass containing gold leaf and hydro-
chloric acid. When the contents of в and c are mixed together, the sparkling
fragments of gold leaf soon disappear.
chloric or muriatic acid and gold leaf, no solution of the metal takes
place, the gold will not dissolve in this acid; but when the contents of
the two glasses, viz., the one containing the nitric acid and the other the
hydrochloric acid, are mixed, the mixture called aqua regia is formed,
which quickly dissolves the royal metal gold; and if the glass containing the
two is placed on one side, the chlorine of the aqua regia will attack and
take the gold into solution, rendering it for the time perfectly invisible.
Founded on this principle that gold is only soluble in aqua regia, or
other liquids in which chlorine is set free, a simple method of examining
rocks (in which the precious metal is not visible) may now be described.
In the absence of a flask, ring-stand, and spirit lamp, a more simple
method may be employed, which would be better adapted to the wants
of those pioneers of civilization who, living in tents in unexplored regions,
must take what they can procure and not what they want. The appa-
ratus required will be, a common saucepan, a few "doctor's phials," a
bit of tinfoil, or some tin scraped off any tinned iron vessel, a few nails,
TESTING FOR GOLD.
191
and the three acids already named-viz., the aquafortis, the muriatic
acid, and the sulphuric acid; these, with an ordinary fire, are all that
will be required.
For the purpose of demonstrating the use of these materials, three
specimens of rock, one of which is known to contain gold, may be pow-
dered separately either on the anvil by the hammer or with an ordinary
pestle and mortar, and a portion
of each specimen can be placed
into a two-ounce wide-mouthed
phial. Into each of the three
phials containing the powdered
rock may be poured some aqua
regia-i.e., two measures of hy-
drochloric acid and one measure
of nitric acid. The bottles and
their contents are now ready to
be heated; but, before doing so, a
bit of tinfoil and some muriatic
acid may be placed in another
similar phial, also a few iron
nails, some water, and a small
quantity of oil of vitriol in a fifth
and similar phial, so that there
are three phials containing the
rocks under examination, and
two containing the materials
required to make the tests for
gold.

The five phials may now be
arranged in a saucepan which
has a fold of paper or a bit of
cotton rag at the bottom to prevent the heat being conducted too
quickly to the glass from the bottom of the iron pot. Cold water is now
poured in, and the saucepan and its contents placed over an ordinary fire.
Fig. 118. The five Phials in the Saucepan con-
taining Water, and placed over the Fire.
As the water becomes hot and boils it communicates the heat slowly
to the contents of the phials, which are now placed in what the chemist
would term a water bath. In about half an hour the saucepan may be
removed from the fire, and the five phials will be found quite sound and
not cracked by the heat, because they have been very slowly warmed.
Three of them will afford the orange-red fumes usually apparent when
aqua regia is used, the other two contain colourless liquids, which
may still effervesce slightly if a small portion of either the tin or iron
remains undissolved, and they are the tests. Pour half the contents of
each of the three bottles containing the minerals separately into three
tumblers half-full of rain-water or the purest water that can be ob-
tained, distilled water, of course, being the best for the purpose, and
then add to each of them a portion of the solution of tinfoil.
The contents of two of the tumblers give no indication of a solid pre-
192
GOLD.
eipitate, or matter thrown down, because one, we will suppose, was yellow
mica (a mineral by-the-bye frequently mistaken for gold), and the other
a mixture of quartz and iron pyrites; but the contents of the third
tumbler afford a very different appearance, and directly the solution of
tinfoil is added, a purplish precipitate, darkening the whole fluid, is per-
ceptible, the perfection of the purple colour being chance work, as
the present operation is somewhat rough; but in the hands of the
skilled a solution of gold yields a magnificent purple compound; when
a solution of the oxides of tin is added to it, the colour is called "The
purple of Cassius," and is used for imparting the rich ruby colour to glass.
The mode of making this purple will be given in the experiments with
gold at the end of this article. In the rough experiment already de-
scribed perfection of colour cannot be expected, but enough is per-
ceptible to enable the observer to distinguish the rock which contains
the gold from the other two minerals that do not contain it. Corro-
borative testimony, however, is absolutely necessary before the exa-
miner would make up his mind as to the presence of gold; and taking
the remaining half of the solution supposed to contain the precious
metal, it may be poured into a fourth tumbler half-full of distilled water,
and to this the solution of the iron nails in water and sulphuric acid
should be added. Gradually a marked precipitate or dark matter thrown
down or produced becomes visible. Let this settle during the night;
the next morning pour off the fluid, a dark brown mud is perceptible;
earthy as it looks, this humble mud is metallic gold, the standard of
excellence, par excellence the sinews of war-the handmaid of peace!
Collect this mud by pouring it on a piece of paper, place by the fire or
in the sun, and let it dry. Then rub the dark particles with a bit of
iron or steel (a key for instance); immediately the mud changes its
poverty-struck appearance (as by the magician's touch) to the gay and
brilliant shining yellow all-commanding gold. The proofs are complete;
"the purple of Cassius" is corroborated by the mud raised to brilliant
gold, as already explained.
If some of the particles are gently smeared on a stone, such as a
"razor hone," they leave a particular-coloured streak. These marks or
streaks were anciently employed as one of the chief tests of the quality
of gold; and hence the use of the “touchstone,” which is even mentioned
in the Bible. The stone was not employed alone, but in conjunction
with "touch needles," whose exact composition was known and made
for special purposes; thus Sir John Pettus minutely describes-
"1. How gold in lumps, plates, ingots, or coyned gold is to be as-
sayed, and first of 'touch needles.'
"2. How the white touch needles are to be made.
3. How touch needles are to be made and used for crown gold.
“4. The division of the touch needles when the metal is half white and
half red.
"5. How touch needles are to be made from Rhenish gold, in which
there is two parts white and one part red.”
From the above division it will be seen that considerable trouble and
THE TOUCH-STONE AND NEEDLES.
193
expense would be incurred by the manufacture of a number of touch
needles, hence Pettus remarks :-
"But the goldsmiths take not so much pains nor are at large ex-
pences, but cut a piece of a duccate, and of a crown, and of a Rhenish

LEFEn-TH
3
Fig. 119. "2. The Proportion of Touch Needles for Gold. 4. The Ingot to be compared
with these Touch Needles; (3) as also by the Touch-stone." (Pettus).
gilder, and soder every one copper piece; after this they touch their
gold; and by this they can very well see whether the gold have its
right contents either in duccats, crowns, or Rhenish gold; but if there be
a different content, then they cannot know how much properly the con-
tent is less."
Pettus also explains "How the touch needles are to be used".
"When thus the touch needles are prepared with diligence, and one
would use them, there is need of a good touch-stone upon which the
gold is to be touched; of such are found some part which are grey and
pale green, but the black ones are best, although the same be not all
good, especially if they are cither too hard or too weak. The weak
ones have this property, that upon them no gold doth touch bright,
but the gold doth only grind on it and becometh in the aspect weake
and ruffe; also the Hungarish or other weak gold will not touch itself
right upon touch-stones, which are too hard for the gold, doth run over
it, that the stroak is not very well to be seen, and that touch-stone is
not good which doth not touch the gold, of what contents soever it be,
with a fine, good, and strong stroak; that it be bright upon it, and also
Q
194
GOLD.
the touch needles, as long until the same stroak be like the gold stroak
in the colour and as high, then ye have very nigh the content of the
gold only, as I have given an account above. Observe well whether the
gold be high-grained-viz., whether it hath much copper added, or
much white, which is called pale gold; according to this use the needles,
which every one doth not understand, and therefore he must have the
knowledge of the right stroak from great practice. But as to the hard
gold, they do not give a right stroak, but they do touch all of a smaller
content than they have in fine gold, therefore such stroaks are to be
judged false and uncertain."
rr
There is another mode of testing a rock containing gold or some
glittering particles, when it is in such a fine state of division that the
hammer-and-anvil test for malleability cannot be well applied. This
mode is a mere repetition of an old alchemical experiment, which is
thus rendered in the books on The Philosopher's Stone." "Hide and
couple in a transparent denne the eagle and the lyon, shut the doore
close, so that their breathe go not out, and strange ayre enter not in.
The eagle at their meeting will tear in pieces and devoure the lyon, and
then be taken with a long sleepe." Such mysterious language appears,
no doubt, very unintelligible-quite worthy, it might be thought, of
the gipsy at Norwood; but still the language, as a whole, is very appro-
priate, and admits of an easy interpretation. Thus, we are told to hide
the lyon and the eagle in a transparent denne. The alchemist does not
say put them into a glass, for how could you get such animals into any
ordinary vessel? the appropriate word "denne" is therefore used,
meaning, of course, a glass receptacle; but what is the lyon? It
means gold, the king of metals, whilst the eagle is the name for quick-
silver or mercury. Put some gold leaf into a glass, and add mercury,
which immediately unites, amalgamates with, or tears and devours the
lion gold. We have now formed a thick amalgam, the quicksilver no
longer runs about so quickly on a flat surface, but is pasty and sluggish;
hence we complete the alchemists' process, by observing that it is, in
their poetical language, "taken with a long sleepe."
The mode of using this plan in practical testing is very simple.
Powder say a quarter of a pound of the rock supposed to contain gold
on the anvil, place this in a wine-bottle, with a quarter of an ounce of
quicksilver, continually shake all together with a little water for several
hours, and when a leisure moment is found, separate the quicksilver
from the earthy matter, observing if it looks pasty. Place this on a
shovel and heat red hot, taking care to avoid the fumes, which are very
poisonous, and would soon produce salivation if inhaled. If any gold
has been taken up by the quicksilver, it will be left behind on the
shovel, and may be scraped off and weighed; a calculation being soon
made to determine, by rule of proportion, the per-centage of gold in
the rock.
Should the examiner wish to economize his quicksilver, he must
squeeze the amalgam through a piece of wash-leather before heating on
the shovel; the fluid matter that passes through is the mercury, which
PURIFICATION OF GOLD.
195
will do again; the pasty matter, if any be left in the leather, is the gold
amalgam, which can be heated as already directed.
Whilst alluding to alchemical processes in connexion with gold,
another may be quoted, with its accompanying illustration, which has
Deen faithfully copied from a work written by Basil Valentine, being
A Practick Treatise, together with the Twelve Keys and Appendix
of the Great Stone of the Ancient Philosophers.'
"}

C
Fig. 120. The Furification of Gold by Fusion with Antimony.
"The king's diadem is made of pure gold, and a chaste bride must be
married unto him; wherefore, if ye will work on our bodies, take the
most ravenous grey wolf, which by reason of his name is subject to
valorous Mars, but by the genesis of his nativity he is the son of old
Saturn, found in mountains and in vallies of the world. He is very
hungry, cast unto him the king's body, that he may be nourished by it;
and when he hath devoured the king, make a great fire, into which cast
the wolf, that he be quite burned, then will the king be at liberty again;
when ye have done this thrice, then hath the lion overcome the wolf
neither can he find any more on him to feed upon, and so is our body
prepared for the beginning of the work.”
The whole of this process may be reduced to very few words, and it
0 2
196
GOLD.
simply means the purification of gold (the king's body) by the
sulphuret of antimony (the most ravenous grey wolf), which in the
mineral state of sulphuret is decomposed by iron filings at a proper
heat (or is subject to valorous Mars, or iron). By fusion with
the metal antimony the impurities are removed from gold, although
that metal takes up a certain proportion of antimony, and must be
purified subsequently by fusion and blowing air on it. It must be placed
with lead in the cupel or test; to use the language of the alchemical
process, "when he [the antimony] hath devoured the king [the gold],
make a great fire, into which cast the wolf, that he be quite burned [sepa-
rated as oxide], then will the king be at liberty again [or the gold
be reduced to the metallic state]."
Pettus gives full directions for casting gold through antimony, which
he says "is a very old invention," so that the gold by it may be made
very clear and fine; but he adds, "so it is not well to trust to this,
that the gold should always come out sure and very clean." The
apparatus used in 1686, and described by Pettus, is almost exactly
that which is employed at the present time; and the next cut is Pettus'
sculpture (so called), showing how the cup, ingot, and other instruments
to the casting through are to be formed.

5
8
27
6
Fig. 121. 1. "The form of the common cup cast in brass. 2. A cup made of smith's work
[to receive the melted antimony and gold]. 3. A crucible for the work [i.e., the casting
the antimony and gold]. 4. A flat test [cupel] for it. 5. The ingot [mould]. 6. The
plates [mould]. 7. The cast antimony with a gold regulus. 8. The cast antimony when
the gold regulus is beaten from it." (Pettus.)
Amongst the various methods of determining whether a substance
with the outward appearance of gold is really the precious metal, none are
THE TEST OF SPECIFIC GRAVITY.
197
more satisfactory than the test of "specific gravity," which, reduced to
its most simple definition, means the weight of equal bulks;" but, as
it would be difficult to prepare exact measures (say cubic inches or
cubic feet) of the metals, the method first devised by Archimedes is
always employed.
Thus a cubic foot of water weighs just 1000 ounces at a temperature
of 60° Fah., the same bulk of gold weighs 19,300 ounces; now, as
water is the standard unit or starting-point to which the weight of the
volumes of all other solids is referred, the specific gravity of water
being 1, that of gold will be 19.3, or gold is more than nineteen times
heavier than water. It has, however, been stated, that exact volumes
of solid substances could not be prepared; but if the specific gravity
is determined by reference to one standard (water), and every solid,
whatever may be its shape, actually compared with its own bulk of
water, then we have a method against which no mechanical difficulties
can be adduced.
Every substance weighed in water weighs less than it does in air,
and this loss is found to be precisely equal to the weight of the volume
of water which it displaces; for instance, a cubic foot of gold weighs
in the air 19,300 ounces, and if thrust bodily into a vessel quite full of
water, it displaces a cubic foot of water, which, if collected and weighed,
amounts to 1000 ounces; and this is the division, for the rule says,
divide the gross weight (19,300) by the loss of weight in water or
water displaced-viz., 1000-and the quotient (19.3) is the specific
gravity.

A
B
F
D
F
Fig. 122. The Principle upon which the Specific Gravity of a Solid is taken. A B. Vessel
full of water. c. The cubic foot of gold placed in the water. D. The cubic foot of water
displaced, and flowing into the vessel, E F.
The loss of weight is of course more apparent than real, and is due
to the upward pressure of the water, by which a portion of the weight
198
GOLD.
of the body equal to the weight of the bulk of the water which it
displaces, is sustained. To put this principle in practice, a delicate
balance should be provided, with the strings of one scale shorter
than the other; and this latter pan may have a hook inserted, for the
convenience of suspending a thread or horsehair from it. The experi-
ment can be made with a sovereign, which is suspended by a horsehair
to the hook of the shorter stringed scale pan, and is found to weigh
123 24 grains. A glass vessel containing distilled water is now placed
under the latter, so that the sovereign is completely surrounded with
water, and if air-bubbles adhere, they may either be cleared away with
a feather; or, what is still better (with gold and other metals and
minerals to which air adheres), is to dip them first in alcohol, and then
in water, which effectually removes the adhering air, and causes the water
to be in perfect contact with the metal. The sovereign will now be
found to weigh 116·34 grains.

A
B
C
Fig. 123. Mode of taking the Specific Gravity of a Sovereign. A B. The delicate balance.
c. Vessel containing distilled water. D. The sovereign suspended by a horse-hair.
Weight of the sovereign in air
""
""
•
in water
123.24
116.34
6.90
The weight of the sovereign in air (123-24) divided by the loss of
weight in water (6·9) gives a quotient of 17·86, being the specific
gravity of the gold, which is alloyed with copper, and therefore weighs
less than pure gold. The standard for coin is twenty-two carats fine;
that is say, it consists of twenty-two parts of pure gold and two
parts alloy.
THE TEST OF SPECIFIC GRAVITY.
Table of the Specific Gravities of the Metal in common use at 60°
Fahrenheit.
Platinum
Gold
20.98
19.26 to 19.3 and 19.64
199
Mercury
Lead
Silver
·
Bismuth
Copper
Iron
Tin.
Zinc
13.57
11.35
•
10:47 to 10.5
•
9.82
8.89
7.79
7.29
6.5 to 7.1
This simple rule may be applied to all metals of any size or weight,
always taking the precaution to clear away with a feather the air bubbles
which attach themselves to the different substances.
When, however, the gold is associated with quartz, another rule must
be made use of, being a modification of the first, which I can recom-
mend, having verified it in practice with some nuggets kindly lent by
Messrs. Hunt and Roskell, of Bond-street.
Practical Method of determining the respective Quantities of Gold and
Quartz in a Nugget.
S. G. Nugget-S. G. Quartz
X
S. G. Gold
S. G. Nugget
S. G. Gold-S. G. Quartz
S. G. Gold-S. G. Nugget S. G. Quartz
S. G. Gold-S. G. Quartz S. G. Nugget
X
x weight of nugget=weight of gold in nugget.
× weight of nugget=weight of quartz in ditto.
To make use of the above formulæ or rules, the reader need know
nothing whatever of algebra. He has only to be acquainted with the
management of vulgar fractions; and he must notice that is the
sign of subtraction; x is the sign of multiplication; and S. G. stands
for specific gravity. For instance,
Ex. I. Suppose we have a nugget weighing 1000 grains, and its
specific gravity is found to be S. Suppose also the specific gravity of
gold were 18, and that of quartz 2. Then, by above rules,
8-2 18
6 18
X x 1000= X ×1000-843 grains of gold in nugget.
18-2 8
18-8 2
16 8
X x1000=
0_10
18-2 8
X
16
2
×1000=1561 grains of quartz in ditto.
Ex. II. Suppose an Australian nugget is brought to us, weighing
10 ounces troy, and we find its specific gravity to be 8.5. Suppose
also we take the specific gravity of gold at 19.0, and that of quartz at
2.5. Then, as above,
8.5-2.5 19:0
oz. troy.
X x10= X ×10=8·128342246 of pure gold in nugget.
19.0-2.5 8.5
19'0-8'5 2.5
6 19
16384
X x 10 = 1023x10=1·871657754 of quartz in ditto.
19.0-2.5 8.5
16 8
200
GOLD.
It may be presumed that this practical mode of estimating the value
of gold nuggets is clear and brief, and as short a rule as it is possible
to conceive. Moreover, it is grasped by the eye all at once-you see
the whole; besides which, it is cast in a perfect mathematical mould,
and must therefore be absolutely and universally true; also capable of
instant application to every conceivable example.
By giving the two formulæ, one for the gold, and the other for the
quartz, we give the reader the readiest possible mode of proving his
own work; thus having (Ex. I.) found the gold in nugget to be 8433
grains, he deducts this from the whole weight, and gets 1564 grains of
quartz for a remainder. He therefore now works by the second formula
to obtain the weight of quartz; and finding it to come (by the inde-
pendent rule) exactly 1561 grains, he has reason to conclude that his
work is altogether right.
Ex. III. Let the specific gravity of gold be 19-26, and that of quartz 2·6.
An Australian nugget, weighing 550 grains, and assumed to contain
nothing but gold and quartz, was found to have the specific gravity
9.77. Required the quantity of gold and quartz respectively in the
nugget.
Let
Then,
x=grains of gold
.. 550-x-grains of quartz.
since gold loses of its weight in water,
1
19.26
1
and quartz loses
ditto ditto,
2.6
1
and also nugget-
ditto ditto,
9.77
x
therefore
19:26
550-x 550
2·60-9.77
And solving this equation, we have
x=466·6256 grains of gold in nugget
and 550—x— 83.3744 grains of quartz in ditto Answer.
Having shown how gold may be distinguished when disseminated
through quartz or other earthy or mineral matter, it will be advisable to
conclude this chapter with the chemistry and technical applications of
gold.
First Series of Experiments.
Pure gold has a specific gravity of 19 3, and its equivalent of com-
bining proportion is 197. It is prepared by dissolving, say, a half-
sovereign in a mixture of one part nitric acid and 4 parts hydrochloric
acid. The coin and the mixed acids are placed in a clean Florence oil
flask, and gently heated by the spirit lamp until the gold disappears.
If any silver is present, it is found at the bottom of the flask in the state
EXPERIMENTS WITH GOLD.
201
of an insoluble chloride, and therefore the solution is diluted with dis-
tilled water and filtered. The filtered liquid is then carefully evaporated
till a drop taken out and placed on a cold plate solidifies; water is again
added, and the solution boiled with some pure sulphate of iron, when
the gold precipitates and sinks to the bottom of the vessel. The dark
powder should now be well washed with water, boiled with hydrochloric
acid, and again edulcorated, and care of course must be taken, in the first
place, to add enough sulphate of iron, in order that all the gold may be
precipitated in the metallic state. The gold powder when dry appears
almost like brown-red earth, but when rubbed or burnished with a piece
of steel, or other hard substance, very soon shows its nature. Some che-
mists prefer boiling the terchloride of gold with oxalic acid instead of with
sulphate of iron, as the flakes of precipitated gold are larger, more cohe-
rent, and more easily manipulated with in the subsequent processes of
boiling with hydrochloric acid and washing with water; but when oxalic
acid is used, all excess of acid must first be removed from the terchloride.
Second Series
To show the perfect insolubility of gold in the mineral acids, some of
the powder obtained from the last experiment may be placed in three sepa-
rate glass test tubes, one of which contains nitric, the second hydrochloric,
and the third sulphuric acid. The finely-divided gold may be boiled for
any length of time in either of these acids, and no solution takes place;
but directly the nitric and hydrochloric acids are mixed, then the gold
is attacked and disappears, and if the solution is carefully evaporated
till it solidifies, pure terchloride of gold is formed.
Third Series.
Oxygen unites with gold in two proportions, and forms with the metal
Protoxide of gold, AuO.
Teroxide of gold (auric acid), Au¤¸.
These combinations do not occur by the direct union of oxygen with
the metal, and indeed, with the exception of chlorine, bromine, fluorine,
and phosphorus, no other non-metallic element unites directly with gold.
Oxide of gold (AuO) is obtained by decomposing the protochloride of
gold with a dilute solution of potash. The protochloride is prepared by
heating the terchloride of gold (AuCl,) obtained in the second experi-
ment, above, to a temperature of 393° Fah. There are two chlorides of
gold, viz., the chloride and terchloride.
Fourth Series.
Purple of Cassius, termed by Gmelin stannate of aurous oxide
(AuO,SnO2, SnO,SnO,+4 HO), being a double stannate of gold and
tin with four equivalents of water, is prepared in various ways; perhaps
the most simple one is to dissolve the pure terchloride of gold men-
tioned in the second experiment, in an abundance of water. If pure ter-
202
GOLD.
chloride has been obtained from a half-sovereign, which weighs about
sixty grains, it may be diluted with at least six ounces of water, and
then placed in contact with pure granulated tin, when a purple pre-
cipitate is obtained, which must be well washed with water and dried by
a gentle heat. The Purple of Cassius is a vitrifiable pigment, and em-
ployed for imparting the ruby red to glass and porcelain.
Fifth Series.
To prepare jeweller's gold, melt, in a good crucible, with a little
borax, three parts of pure gold, and add thereto one part of copper.
Gold for coin consists of eleven parts of pure gold and one part of
copper.
Sixth Series.
China is gilt by first triturating gold leaf with turpentine and borax, and
then laying this mixture on the porcelain, which is subsequently brought
to a proper heat in an oven or muffle surrounded with burning coal.
Ordinary gilding, such as that of picture-frames, is performed by first
laying on a tacky, sticky varnish, called gold size, to which the gold leaf
firmly adheres, and when hard and dry can be washed with soap and
water; but if the gold leaf is only laid on with parchment size or gum,
it is easily affected by water, and may soon be washed off.
Seventh Series.
Water gilding, so called (being a most pernicious process to those
engaged in it), is conducted by first preparing an amalgam of gold and
mercury. The copper article is then cleaned with dipping acid, com-
posed of equal parts of nitric and sulphuric acids, well washed with
water and placed in a solution of nitrate of mercury, when metallic
mercury is precipitated upon and adheres to the copper. The amalgam
of gold is then carefully spread over the amalgamated copper surface,
and the article is placed in a proper oven or muffle heated to about 700°
Fah., when the mercury volatilizes and a beautiful coating of dead gold
remains behind. When this operation is conducted on the large scale,
care is taken to get rid of and condense the fumes of mercury; and
indeed this dangerous process is now happily almost entirely super-
seded by electro-gilding.
Eighth Series.
When terchloride of gold is dissolved in sulphuric ether, the solu-
tion may be employed for ornamental gilding on cutlery, or writing
initials or names on steel articles. It is also sometimes used to pre-
serve the sharp points of steel surgical instruments from rusting. The
best mode of preparing the ethereal solution is to dissolve the terchloride
of gold first in a little water and then to shake some ether with it in a
long tube, and the two liquids, viz., the ether containing the chloride of
gold and the remaining water solution can afterwards be separated by
EXPERIMENTS WITH GOLD.
203

decantation. The ethereal solution of
the terchloride of gold should be kept
in a dark place or opaque bottle.
The gilding by the ethereal solution
of gold is not, however, very perma-
nent, and therefore polished steel is
gilded with gold leaf. The steel is
just heated till it takes a bluish
tint, a first coat of gold leaf is now
applied, which is pressed gently down
with a burnisher and then exposed to a
gentle heat. Several leaves, either
single or double, are thus applied in
succession, and the last is burnished
down cold. A fine illustration of this
kind of gilding is shown in the annexed
cut. (Fig. 124.)
Ninth Series.
Books are gilt and lettered by means
of heated metal stamps of the letters
or devices; these are pressed on the
cover, which is previously dusted with
powdered resin, and the gold leaf laid
over it. Wherever the hot stamp
touches, the resin melts and the gold
adheres to it, and the remaining leaf
is dusted off with a brush.
Tenth Series.
Gilding by the wet process may be
conducted in various ways, and the
metal, of course, is first reduced to a
soluble state by conversion into ter-
chloride.
Process of M. de la Rive.-Pour a
solution of chloride of gold exactly
neutralized with carbonate of soda, and
containing only a very small quantity
of gold, into a glass cylinder whose
lower extremity is hermetically closed
with moistened gut skin, and introduce
Fig. 124. Wilkinson's Exhibition Sword, orna-
mented with precious stones and gold devices.
The blade is of the finest temper, and combines
embossing with engraving, bluing, and gilding,
so as to form two clevations of a highly orna-
mental pattern. (Art Journal.)
204
GOLD.
the cylinder into a vessel which contains some water very slightly acidu-
lated with a few drops of sulphuric acid. The cylinder should be sup-
ported so as to prevent its lower surface from resting immediately on the
bottom of the larger vessel. It is necessary to carefully clean, or even polish
the surface of the metal, whether of silver or brass, that we desire to gild,
lest a portion of it should be left ungilt. To attain this end it is sometimes
advisable to place the metal for a few minutes in contact with zinc in
dilute sulphuric acid, so that hydrogen may be disengaged on its sur-
B
B
face; after which it must be well washed. In
order to gild an object, it must be fixed or
suspended by a platinum wire, to the other
extremity of which is attached a plate of zinc;
this done, plunge the article to be gilt in the
solution of gold and the zinc plate in the
acidulated water. The power of the electric
current may be moderated at will by im-
mersing more or less of the zinc plate, so that
no hydrogen may be disengaged, and that in
this case the chloride of gold is alone decom-
posed. After a minute the article to be gilt
is withdrawn, wiped dry with a fine linen
cloth, rubbed a little, and again immersed.
After two or three immersions the metal will
be found sufficiently gilded. By the above
conducted with the chloride of gold only, no
process it will be noticed that the gilding is
cyanide of potassium being used; and the
article to be gilt must not be left for a mo-
ment in the gold solution without galvanic
connexion, otherwise it will not be gilt at all
or the gilding will be very bad. It is, there-
fore, advisable to place the zinc in the acid
first, and then to bend down the wire to
which the article is fixed into the solution of
chloride of gold. The solution of gold should be diluted with water until
a plate of silver dipped into it no longer acquires a black coating, but
exhibits a bright yellow colour on being rubbed. Steel pens, freed by
dilute hydrochloric acid from their blue film of oxide, may be gilt with-
out the aid of galvanism by simply immersing them in the gold solution
neutralized as above with carbonate of soda.

Fig. 125. De la Rive's Process
Fig. 125. De la Rive's Process
of Gilding. A. Lamp chimney
closed at the lower end with
bladder containing the solution
ported so that the bladder end
does not touch the bottom of
of chloride of gold; it is sup-
B B, the outer vessel, containing
the acidulated water.
c. The
plate of zinc attached by a wire
to the article which is to be
gilt.
Eleventh Series.
The following method of gilding is said to give the best results.
The gold solution is prepared by dissolving one part of the terchloride
of gold and ten parts of ferrocyanide of potassium in one hundred parts of
water, which is filtered from cyanide of iron, and mixed with one hundred
parts of a saturated solution of ferrocyanide of potassium, and the
ELECTRO-GILDING.
205
A
A
C
whole diluted with an equal or double portion of water; the more
dilute the solution, the brighter is the frosted gilding produced, and
placed in a porous vessel or glass tube, closed with bladder. In the
outer vessel, containing the zinc plate, is placed a solution of ordinary
ferrocyanide of potassium and common salt; the latter salt alone, acts
more quickly, but for gilding silver, the solution must not contain too
much common salt, otherwise the silver will be blackened by the forma-
tion of chloride. It is advantageous to have the two solutions-viz.,
the one in the porous vessel, and the other in the outer cell-of the
same level and specific gravity, so that they may not mix too easily.
The zinc must not be amalgamated, otherwise chloride of mercury will
be introduced into the gold solution, and may be reduced on the metal.
The vessel containing the gold
may be either a tube closed with
bladder, or an inverted gas jar of
which the neck is tied over with
linen and a layer of clay free from
lime and moistened with a solu- C
tion of common salt and about a
quarter of an inch thick, placed
above or on the linen, so that it
represents the bottom of the vessel
containing the gold. While the
gilding is going on the object is
frequently moved, in order to
keep the very dilute solution of
gold as nearly as possible in one
uniform condition. If the depo-
sition goes on too slowly, an addi-
tional quantity of common salt is
added to the liquid in the outer
vessel containing the zinc plate.
Warming the outer vessel in a
water bath to 68° or 77° Falı.
likewise accelerates the gilding,
but diminishes its lustre. If any
of the gold solution penetrates
into the outer vessel, and gold is
in consequence precipitated upon
the zinc, it must be removed. A
thin deposit of gold makes its
appearance in ten minutes; to
produce a thick deposit several hours are necessary. The gilding on
silver is first greenish, then, yellow, then, after twelve hours, reddish
yellow. Brass and bronze take the gilding much more quickly. Finally,
the gilt object is washed with dilute sulphuric acid, which removes any
iron that may perchance have been precipitated, and then rubbed with
leather. The articles to be gilt are either cleaned by being dipped into


B B
Fig. 126. A A. Inverted gas jar. B B. Neck
of jar closed with linen and clay; the jar con-
tains the solution of gold. cc. The outer
earthen vessel containing the solution of ferro-
cyanide of potassium and chloride of sodium:
also the plate of zinc not amalgamated, and
attached by a platinum wire to the spoon.
206
GOLD.
dipping acid and well washed with water, or they are first well burnished
and then thoroughly cleaned by rubbing with lampblack moistened
with concentrated nitric acid and spread upon linen; then dipped
rapidly in water, and again rubbed, and so on, until perfectly clean, when
they are well dried.
Twelfth Series.
Process of Walker.-Terchloride of gold is dissolved in cyanide of
potassium, and an independent small battery used. The article to be
gilt is first cleaned, and then connected with the negative element,
whilst a small sheet of gold is connected with the positive; both are
placed in the solution of gold, which is thus maintained at one uniform
strength; for, as the gold is deposited on the article, it is also dissolved
from the gold plate.
Thirteenth Series.
A solution of gold can be made by placing a bit of gold foil in a
solution of cyanide of potassium connected with the positive element of
a small battery, whilst the negative element is placed in contact with an
iron plate enclosed in a porous cell containing some of the same solution

A
B
E
}
N
D
F
Fig. 127. A B. Vessel containing a solution of cyanide of potassium. CD. The gold
foil in connexion with the positive pole of the battery, and immersed in the solution
of cyanide of potassium. B F. A porous cell, also containing cyanide of potassium
solution, and a plate of iron connected with the negative pole of the battery. The
arrows show the direction of the current.
of cyanide of potassium, and of course standing in the same vessel with
the foil of gold. Napier recommends that the solution of gold should
be heated to a temperature of 130° to 150° Fah. in a water bath,
which enables the gilder to employ less battery power. The battery
for dissolving the gold foil may consist of five pairs of Smee's arrange
ment and of two or three for gilding small articles; the gilding solution
should contain about half an ounce of gold to the gallon. Napier do
EXPERIMENTS WITH GOLD.
207
scribes the deleterious nature of the gases, cyanogen and hydrogen,
which are evolved during the electro-gilding process on the large scale,
and recommends abundant ventilation, with the use of large rooms.
Even amateurs are warned not to keep their small experiments performed
in tumblers in their bedrooms, as the practice is decidedly dangerous.
Fourteenth Series.
The tests for gold have already been partly described in the first
portion of this article on gold, but they are here placed together for the
use of those who wish to know how to distinguish gold by chemical re-
agents.
The chlorides of gold are all yellow, and their solutions present
gradations of yellow up to the highest points of dilution.
Potash in excess does not precipitate gold, but a small quantity in
concentrated solutions of gold, with the assistance of heat, throws down
a reddish yellow precipitate, the teroxide of gold, AuО3.
3'
Ammonia produces, in strong solutions of gold, a similar coloured pre-
cipitate of aurate of ammonia, or fulminating gold.
Sulphuretted hydrogen precipitates from acid and neutral solutions of
gold the whole of the gold which they contain as black sulphuret of
gold, AuS,, insoluble in potash, or in any single acid, but soluble in
alkaline sulphurets and in aqua regia.
Hydrosulphuret of ammonia produces the same result, and in excess
re-dissolves the precipitate.
A solution of protochloride of tin warmed with a few drops of nitric
acid, produces with a solution of gold the well-marked precipitate of
purple of Cassius, which is insoluble in hydrochloric acid.
A solution of protosulphate of iron reduces the oxide of gold to the
metallic state, and precipitates it as a reddish-brown powder, which, being
collected, boiled with hydrochloric acid, and well washed and dried, may
be pressed and burnished, and will show the colour and brilliancy of
gold on any hard surface, such as a touch-stone or bone.
The very finely-divided gold thrown down by the protosulphate of
iron appears blue or blackish blue by transmitted light; and this is
apparent even when 40,000 parts of liquid are used to one of terchloride
of gold. When the dilution is doubled, or 1 in 80,000 parts, the colour
is sky-blue; 1 in 160,000 parts, violet; 1 in 320,000, the violet tint is
still recognisable, but is difficult to appreciate when the dilution is car-
ried to 1 in 640,000 parts.
Fifteenth Series.
An amalgam composed of half an ounce of gold and one hundred
pounds of mercury is liquid, and may be completely squeezed through lea-
ther. But if four ounces of silver be likewise dissolved in the mercury,
and the product pressed through leather, 284 ounces of amalgam remain
in the leather, containing the half-ounce of gold and 3 ounces of silver.
The whole of the gold, together with the greater part of the silver, is,
therefore, separated in the form of a solid amalgam.
}
208
GOLD.
Sixteenth Series.
White silk may be gilt by wetting it with a solution of terchloride of
gold, and then exposing the silk to the action of sulphurous acid gas,
which may be easily obtained by burning a little sulphur under a jar,
and confining the vapour. The silk is covered with a coating of minute
particles of gold in a very short space of time.
Another pretty experiment, illustrating the reduction of gold from
its combination with chlorine, and called many years ago "the mineral
rainbow," may be produced by pouring a small quantity of a solution
of terchloride of gold into a dish, plate, or cup containing some ether
in which phosphorus has been dissolved; the gold is instantly reduced
in exquisitely thin films, presenting purple, blue, and red colours, with
more or less metallic brilliancy.
Seventeenth Series.
Three parts of sulphur and three of caustic potash dissolve one
part of gold when boiled with it in water. This is the process of Stahl,
and is the one he supposed Moses was acquainted with when he reduced
the golden calf to a fine powder, and made the Israelites drink it. This
idea of Stahl's is refuted by the words of the text, as already quoted
at p. 118.

Fig. 128. Votaries dancing round the Golden Calf (N. Poussin).

C
Fig. 129. 1. Assayer. 2. The scales. 3. The cases for weights. 4. Glasses for aqua
regia, aqua fortis, aqua vitrioli, aqua argentum, and quicksilver. (Pettus.)
CHAPTER V.
SILVER.
The semicircle is the image of the moon, the only planet that appears under that
aspect to the unassisted eye.
ALTHOUGH the metamorphic and granitic rocks are destitute of organic
remains, they are traversed by numerous mineral veins, some of which
are probably gold (although no one has yet been fortunate enough to
arrive at a vein of the latter metal), some of silver, others of various
mineral veins, containing lead, copper, nickel, antimony, zinc, whilst tin
ores appear to be specially confined to granitic rocks.
Many years ago a vein of silver ore was wrought with considerable
profit in the parish of Alva in the county of Stirling. The metalliferous
minerals were native silver, and silver glance, sulphide of silver, with
ores of copper and cobalt; and the vein stones were calcareous spar
(carbonate of lime), and heavy spar (sulphate of baryta). It is said that
the value of the silver extracted amounted to forty or fifty thousand
pounds sterling.
P
210
SILVER.
Native silver has been met with in various parts of Cornwall, and is
associated with galena (sulphuret of lead), iron pyrites (sulphuret of
iron), bismuth, cobalt, and wolfram (tungstate of iron), in veins traversing
clay slate. In Europe, perhaps the most celebrated silver mine is that
of Königsberg in Norway, in the neighbourhood of Mount Johnskunden,
which towers up to the height of more than 3000 feet. The mines
were first worked in the year 1624; the deepest is 180 fathoms, and
out of it was taken an enormous mass of native silver, now in the Mu-
seum of Natural History at Copenhagen, measuring six feet long, two
feet broad, and eight inches thick, and estimated to contain five hundred
pounds' weight of pure silver.
In Europe silver occurs in Sweden, Saxony, Bohemia, Silesia, Swabia,
Wirtemberg, also in France, Spain, Hungary, and Transylvania. In Asia,
Siberia, and especially China, where silver constitutes the chief portion
of the currency. Silver mines are worked in North and South America;
Mexico, Peru, and the mines of Gualgayoc, and those of other localities
in the same quarter of the globe, are the most celebrated sources of
silver. Humboldt asserted that the mines of Mexico and Peru afforded
more than 316,000,000 lbs. troy of silver in the course of three
centuries, and he also remarks that this silver would form a solid sphere
of a diameter of 91,206 feet. M. Brongniart, a French mineralogist,
has ascertained the average annual quantity of silver supplied from the
following localities between the years 1790 and 1802.
Asia:-
Siberia
Old World.
40,200 lbs. troy.
Europe:-
Hungary
46,000
""
Austrian dominious
11,000
Harz and Hesse
11,000
•
>>
Saxony
22,000
Norway
22,000
"
Sweden
France
11,000
رو
Spain
Total Old World
165,000 lbs. per vear.
North America
1,400,000
885,000"
South America.
Total from America 2,285,000 lbs. per year.
Notwithstanding this large supply of silver, it would appear to be
used almost as quickly as it is produced, and it is absorbed and lost
sight of-we must not say destroyed-by the wants of the various civi-
lized communities; such as the hoarding of coin and family plate, the
SILVER IN SEA WATER.
211
use of silver in medicine, and also in the arts of electro-plating and
photography. It has been said that the ocean may contain a little
of everything soluble in water, and it is curious to find, from the experi-
ments of foreign chemists, that sea water contains an appreciable
quantity of silver in solution. Malaguti, Durocher, and Sarzeaud have
ascertained that a small quantity of silver occurs in sea salt. Sea water
itself contains about one milligramme in one hundred litres; various

Fig. 130. Fucus serratus and Fucus ceramoïdes, which contain of silver, from
specimens kindly supplied by Mr. Boswarva, of Plymouth.
P 2
212
SILVER.
seaweeds, the Fucus serratus and F. ceramöides (Fig. 130), contain at
least 1000; it is also present in chemical products for the preparation
of which common salt is used, as, for instance, in carbonate of soda and
hydrochloric acid. Silver is likewise found in the ashes of land plants,
and the insoluble portion contains more silver than the soluble portion;
the ash of ox-blood, rock salt, and most probably coal also, contains
minute traces of this precious metal. As gold chiefly occurs in the
metallic state, the processes by which it is separated from its matrix or
from the alluvial deposits through which it is disseminated, are
by no means complicated; but with silver, which is much more plenti-
fully distributed in the mineralized than in the metallic state, the me-
tallurgical processes by which it is procured in a purer form are more

Fig. 131. Native Silver.
Silver is found in about fifteen different
complicated and ingenious.
species―viz. :—
1. Native silver.
2. Native amalgamated silver ( Silver and from 13 to 64 per
and mercury
3. Auriferous native silver
4. Antimonial silver
5. Arsenical silver ore
•
cent. of mercury.
Silver and about 28 per cent.
of gold.
Silver and from 11 to 25 per
cent. of antimony.
Silver and about 35 per cent.
of arsenic, with iron and
antin ony.
SILVER ORES.
213
6. Bismuthic silver ore
Silver and about 27 per cent.
bismuth, with lead, iron, cop-
per, and sulphur.
7. Horn silver, or native chloride of silver.
8. Silver glance, sulphuretted ( Silver and from 15 to 25 per
silver, or vitreous silver
9. Brittle or black silver ore, or
brittle sulphuretted silver,
or brittle silver glance
10. Red silver ore
11. White silver ore or white
silver.
12. Grey silver ore, or carbonate
of silver.
13. Eucairite.
14. Iodide of silver.
15. Bromide of silver
•
S
cent. of sulphur.
Silver and sulphur, antimony,
iron, copper, arsenic, and
earthy matters.
Silver, oxide of antimony, and
sulphur.
Silver, lead, antimony, iron,
sulphur, aluminum, silica.
(Silver, carbonic acid, antimony,
and copper.
Silver, copper, and selenium.
Silver and about 23 per cent.
of iodine.
S Silver and about 12 per cent.
of bromine.
The most important metallurgical processes by which silver is pro-
cured chiefly from the native silver ore and the sulphurets of silver
and lead may be arranged as follows :—
No. 1.
Amalgamation with mercury, after treating the powdered silver ore
with salt and sulphate of copper, by the Mexican and the European
methods.
No. 2.
The silver ore, after being roasted alone or with salt, is subsequently
treated with metallic copper.
No. 3.
The reduction of lead ores, the crystallization of the lead, and the final
separation of the silver on the cupel by the very ingenious process of
Pattinson.
The Mexican amalgamation process is said to have been invented by
a miner of Pachuca, called Bartholomew de Medina, and it dates from
the year 1557, although some authors assert that it was practised long
before in Germany. The ore is first reduced to powder by stamps, and
then transferred, after being sifted, to the crushing-mills, or stones
moving in troughs with water. Each mill is called arrastras, and
grinds from eight to ten hundredweight of mineral in about twenty-
214
SILVER.
four hours. If the ore is rich in silver, so much care is not used in
reducing the mineral to powder; it is sufficient if it be reduced to about
the fineness of sand. When the ore, in the state of fine mud, is thought

பாரர்
Fig. 132. A Crushing Mill used in Mexico.
to be fine enough, it is carried while yet wet into the amalgamating
yard which is paved with large stones. It is then heaped up in masses of
from twenty to thirty hundredweight, and forty or fifty of these heaps
are called a tourte. This quantity is then left to itself for a considerable
time, after which common salt is added, in the proportion of from four
to twenty per cent., according to the quality of the ore. If the ore does
not contain, as it sometimes does, pyrites and sulphate of iron, this
substance is also added, mixed with roasted copper pyrites or crude
sulphate of copper, called magistral, and finally, lime and vegetable
ashes are put on the heap. These different substances are trodden to-
gether by horses, and being carefully mixed, are allowed to remain
together for several days. According to the nature of the ore, their
action on one another varies. If the mineral contains naturally the
sulphates of copper and iron, or contains much chloride of silver, the
heat generated is too great, and is diminished by a further addition of
lime. If much sulphuret of lead is present, or the pyrites difficult to de-
compose, the chemical action is feeble or does not take place, and must
De promoted by augmenting the temperature. Then also magistral, or
THE MEXICAN PROCESS.
215
a mixture of sulphate of iron and copper is added. The operation is
thought to go on well when a portion of the mixture, on being placed
in the hand, causes a sensation of heat. A few days afterwards, about
six times as much mercury as the tourte, or torta, is supposed to contain
silver is added, as well as more magistral. The mercury is allowed to
filter through a bag made of coarse canvas, which causes it to escape in
innumerable small jets over the whole surface of the heaps, and the
whole is again thoroughly incorporated by driving twelve or twenty mules
round it for several hours, or a considerable number of barefooted
workmen march backwards and forwards in this metallic and mercurialized
mud. What the effect may be on the health of the men and animals is
not stated, although it can easily be conceived that it must be pre-
judicial.
Every day the overseer ascertains the progress of the work by washing
a portion of the mixture in a wooden bowl, and judging by the aspect
of the amalgam. When the mercury assumes the colour of ashes,
separates in a grey powder, and sticks to the fingers, the heat is too
great, and more lime is added. If, on the contrary, the mercury retains
its metallic lustre, or is covered with a red or golden scale, if it does
not appear to act on the mass, the heat is increased by the addition of
magistral.
The process is
very tedious, and lasts about five months; and when
the amalgamation is judged complete, the mud is thrown into troughs,
made either of stone or wood, in which the arms of a mill revolve so
as to stir it; a stream of water passes through, and the lighter
earths and the oxides are carried away, and the amalgam which remains
at the bottom is put into a strong leather bag with a canvas bottom,
through which the mercury penetrates, whilst the pasty amalgam re-
mains behind; it is then subjected to a gentle pressure, and moulded into
wedge-shaped masses, each weighing about thirty pounds. The remaining
mercury is then distilled off, and the silver is finally cast into bars.
The rationale of the process depends on the mutual decomposition of
the salt and sulphate of copper, which are converted into sulphate of
soda and chloride of copper; the latter is acted upon by the metallic
silver, and a subchloride of copper produced, with the formation of
chloride of silver. The subchloride of copper dissolved in the solution
of common salt reacts on the sulphuret of silver with the formation of
more chloride of silver and sulphate of copper. The mercury is partly
changed by contact with the chloride of silver into subchloride of mer-
cury, whilst the metallic silver amalgamates with the excess of mercury.
To prevent the formation of free protochloride of copper, which causes
a great loss of mercury, by converting it into chloride of mercury, lime
is added for the purpose of decomposing the excess of chloride of cop-
per, and keeping it in the state of subchloride.
The following table exhibits the complicated changes which are sup
posed to occur, numbered in the order of their succession, water, of
course, being present:-
216
SILVER.
Materials.
No. 1 {Chloride of sodium
Sulphate of copper
•
:}
No. 3 { Metallic silver (in the ore).
Chloride of copper }
Chloride of sodium
•
•
No. 5 Subchloride of copper
•
Sulphuret of silver (in the ore)
No. 7 {Chloride of silver
Metallic mercury
Products.
= No. 2 { Sulphate of soda.
= No. 4
Chloride of copper.
Chloride of silver.
Subchloride of copper.
No. 6 Sulphate of copper.
Chloride of silver.
Subchloride of mercury.
= No. 8 Silver amalgamated with
mercury.
Gmelin remarks, "Might not many of the poorer silver ores be treated
as follows?-Pounding them finely, washing them if they contain sul-
phur, and heating them with a quantity of oxide of manganese and
hydrochloric acid sufficient to convert the sulphide of silver into chloride,
washing thoroughly with water, dissolving out the chloride of silver by
ammonia, separating the alkali by distillation, and reducing with sul-
phuric acid and iron.'
ور
The European process of amalgamation is conducted in a much more
expeditious and scientific manner by the assistance of heat, and roasting
the silver ore and salt together. The roasted ore is sifted and the
lumps mixed with more salt and roasted over again. The whole is
ground and sifted, the process being finished by the decomposition of
the chloride of silver with iron and the amalgamation of the metal with
mercury; the latter part of the process is conducted in barrels, which
are made to revolve at a velocity depending on the particular stage of the
process. (Fig. 133.) In the European, as in the Mexican process of amal-
gamation, the object is to obtain chloride of silver, which is decomposed,
and the metal amalgamated with the mercury. Halsbrücke, a mining village
in Saxony, in the vicinity of Freyberg, and about eighteen miles from
Dresden, is the site of the most important and complete amalgamation
works in Europe.
The refining and desilvering of lead by Pattinson's process is, like
nearly all clever and profitable discoveries, one of the most simple that can
be conceived, and is based on the principle that pure, or nearly pure lead,
crystallizes sooner than an alloy of that metal containing silver. When
lead containing silver is melted in a crucible or iron ladle, and allowed
to cool slowly, solid particles or crystals form within the fluid lead,
which sink to the bottom, and may be easily removed, and when assayed,
are found to contain less silver than the remaining fluid portion, which
becomes proportionally richer in silver.
This method of extracting silver from lead was discovered by Mr.
H. L. Pattinson, at Newcastle-on-Tyne, in 1829, and is said to have
been the result of accident; but it may be asked, what is the use of
these accidents happening to most persons? If Pattinson had not been
AMALGAMATION BARRELS.
217

A
C
B
E
E
D
E
E
HIN
D
E
E
C
EX
TIHNE DIERREKELLAD
NI
D
E
E
E
E
H
E
H
E
ETM
D
D
E
EU
H
F
H
Fig. 133. Amalgamation Barrels. A is the moving wheel; B is another wheel, with 108
teeth on the axle of A; c, c are smaller cog wheels, working to correspond with B, and each
of the axles on which they are placed gives motion by means of cog wheels marked D, to
a number of amalgamating casks marked E, which are all provided with a half-circular
piece of iron marked r, used in conjunction with a screw, to secure the opening of the
cask after the materials are put in; G, G, G, G, are also screws, the purpose of which is to en-
able the workmen to move any of the casks from the contact of the teeth of the wheels
marked n, so that it may be worked at without stopping the movements of the other
casks; H, H, H, I, indicate the iron gutter which serves to convey the mercury into any one
of the casks at pleasure; they are composed of several pieces, which can be moved in any di-
rection. In general there are 20 casks in a set, each of which contains about 300 lbs., or 30
gallons of water, and about 1000 lbs. of the decomposed mineral and pieces of scrap or forged
iron. The casks are fastened up and rotated for about an hour; 500 lbs. of mercury are
then put into each cask, and it is firmly closed. The machinery is so regulated as to permit
the casks to turn round about fifteen or twenty times in a minute. Every four hours the
amalgamation is examined, and in about sixteen hours the operation is completed.
218
SILVER.
gifted with great powers of observation, this valuable principle might
have been still unknown, and therefore the credit of the discovery need
not be diminished on that account, although it seems to be the fashion
to depreciate the merit due to a discoverer if he happens to have wit
enough to grasp and apply a new fact which comes accidentally before
him. By the old method of separating silver from lead, it was necessary
to remove the baser metal by oxidation and conversion into litharge, and
then to finish the rich argentiferous lead upon the test or cupel. This
process might be made profitable with lead which contained from nine
to eleven ounces of silver to the ton of lead, but could not possibly pay
where the silver amounted to about one ounce per ton; but since the use
of Pattinson's process the produce of silver in the United Kingdom has
been almost doubled during the last thirty years; and even lead con-
taining a single ounce of silver per ton may be profitably desilvered.
Moreover, the trade is greatly increased by the importation of foreign
lead, which is subjected to the same process. In order to carry out
Pattinson's process, a series of eight or ten moderately shallow cast-iron
pans are set in brick-work, with a fireplace beneath each vessel, which

EC
AUTOLE
Fig. 134. Pattinson's Process. A A B, iron pans containing the argentiferous lead.
c, melted lead to keep the ladle hot.
PATTINSON'S PROCESS.
219
is capable of holding about five tons of metal. The desilvering is com-
menced by placing five tons of lead, called original lead, and containing,
say, ten ounces of silver to the ton, into the middle pot of the series,
which we will call ▲ (Fig. 134); when the whole is melted, the surface of
the metal is carefully skimmed and the fire withdrawn; as the cooling pro-
ceeds, the liquid lead is stirred with an iron spatula, and, like a satu-
rated solution of common salt under similar circumstances, crystals soon
begin to form, which sink to the bottom of the pan, and are taken out
with a perforated ladle, that collects the solid particles of lead, and
permits the fluid to run back again into the iron pan. As the crystals
are taken out they are placed in the empty pan to the right hand side
until about four-fifths, four tons, have been taken out, when the re-
maining fluid portion, or one ton, is ladled into the empty pot to the
left of the workman; and the same operation repeated on five tons more
original lead in the pot first used. It is evident that three pots, with the
extra small pot c (Fig. 134) containing lead always heated for the purpose
of keeping the ladle at the right temperature, so that the lead shall not
solidify in it and stop up the holes at the bottom, would be sufficient to
carry out the principle, but a great saving of silver and time is effected
by arranging more pans right and left, so that the pure lead which crys-
tallizes out is continually passing to the right, whilst the rich argenti-
ferous lead is carried to the left. In every pan, when full, the lead is
crystallized again, so that by the time it reaches the last pot to the right
a mere trace of silver is left in the lead, which is cast into pigs. The
enriched lead, called lead riches, passes from the last left-hand pot when
it contains three hundred ounces of silver to the ton of lead, and is cast
into bars about two inches square.
The last portion of lead is removed from the silver by melting and
oxidizing the mixed metals upon a peculiar shaped vessel, of which the
frame or skeleton consists of iron, and on this is worked a superstructure
of bone earth or burnt bones, mixed with a certain proportion of fern
N°1.
N2.


Fig. 135. No. 1. The iron rame of the test. No. 2. The iron frame rammed hard
with damp bone-earth and dried, called the test or cupel.
220
SILVER.
ashes, and called a test or cupel, and having very much the shape of a
meat dish. (Fig. 135.)
The test is placed in a furnace of a peculiar construction, so that
the heated air and flame pass over it and up the chimney; and, in the
first place, the heat must be most carefully applied, or else the test will
be cracked and spoilt. When the test is sufficiently hot, the lead riches
are melted in a side furnace, and poured into it. At first, the surface
appears to be covered with dross, but in a short time it clears off, and
the surface of the melted lead increases, and a film of melted litharge
appears, which sinks into the test as if into a sponge; but when this is full,
then a draught of air is directed over the surface of the argentiferous lead,
and as the test is kept constantly filled with lead riches, the litharge or
oxide of lead flows over the hollow part of the test, and is collected in
a pot beneath. If the cupellation is conducted in one test to the end,
directly the last portion of lead is oxidized and removed, the whole
surface of the metal in the test suddenly brightens up and looks ex-
ceedingly beautiful; and if the silver is allowed to cool, another curious
phenomenon is exhibited, called spitting, by which a quantity of oxygen
gas dissolved in the fluid silver, like the solution of any gas in water,
is suddenly discharged, producing those irregularities on the surface of
the silver which very much resemble exhausted craters of extinct
volcanoes. It may be prevented by throwing charcoal powder on the
melted silver. At the Great Exhibition in Hyde Park masses of silver
presenting the appearance just described were exhibited, one of which
weighed 7703 ounces troy, and another, exhibited by Mr. Sopwith,
weighed 12,162 ounces. Having thus briefly described the processes
by which silver is obtained from its ores, we may now pass to the
chemistry and technical applications of the metal.
EXPERIMENTS WITH SILVER.
First Series.
Pure silver has a specific gravity of 10:47, and its equivalent or com-
bining proportion is 1081; its malleability and ductility are next to
those of gold; silver leaves have been beaten out as thin as the ten-
thousandth part of an inch, and five grains of silver may be drawn out
into a wire two thousand feet long. It is separated from all common
metals with which it is likely to be associated, except gold and platinum,
by the process of cupellation called the assay of silver by the "dry
method." The method of separating lead from silver on a large scale
has already been explained in connexion with Pattinson's process; but
in order to conduct an assay, little cups of bone earth must be con-
structed by forcing it, while slightly damped, into a proper mould. The
form and mode of making these cupels are as well illustrated in the
MANUFACTURE OF CUPELS.
221
work of Pettus as in the modern works on metallurgy; and, indeed,
the use of the cupel, or copel, appears to be very ancient.

JENECKERIALE | REPOLLJUDI LIKYTNO
munar
WEL
JILY
Fig. 136. "1 and 3. Copel moulds or cases. 2 and 4. The copels that are made in them.
5. The copels as they are set upon one another. 6. The washed bone-ashes or char made
into balls. 7. He that works the ashes. 8. He that strikes the copels into their moulds
or cases." (Pettus.)
When the cupels are dry, they are heated by being placed in a sort of
earthenware oven, with slits or openings in it at the sides, and called a
muffle; this latter is supported in a furnace, so that the open mouth of
the muffle corresponds with that of the furnace. The various forms of
the muffles and portable furnaces are likewise well illustrated by Pettus,
and leave little to be desired.
The fuel is put on at the top and lower opening, and the muffle is
supported on iron bars above, so that the mouths of the muffle and
222
SILVER.
furnace are one. After the cupel is sufficiently heated, the lead con-
taining silver is placed into it, and the heat being urged for a few

00000
아이
​оф
6
Fig. 137. "Nos. 1, 2, 3. Different forms of muffles.
of tiles joyned together, which may quickly be done.
of armour plate. No. 6. The foot of it." (Pettus.)
No. 4. An assay oven made
No. 5. An assay oven made
minutes, the lead soon melts, the dross on its surface flows off, and sinks
into the cupel, and the metal is uncovered; when that takes place, the
heat must be regulated, and the oxide of lead or litharge is soon
absorbed into the cupel, and the brightening of the little speck of silver
at the termination of the process demonstrates when it is complete. A
great many precautions are necessary in conducting the assay. The
muffle must neither be too hot or too cool: in the one case the silver is
carried off and lost by sublimation and absorption into the cupel; and in
the other, the absorption of the litharge into the cupel does not go on
THE MUFFLE FURNACE.
223
properly, the little speck or button of silver is not properly refined,
and contains a certain amount of lead. The mouth of the cupel must
be closed or half closed or opened during the process, according to
circumstances, and convenient tongs are supplied for the purpose of
putting in or taking out the cupels. At one of the meetings of the
Cheinical Society Mr. Taylor made the following interesting obser-
vations on a new form of muffle and a simple mode of cupelling, which
appears to be well adapted to amateurs and others who do not wish to
incur the expense of building a muffle furnace, such as that depicted in
the next cuts:-

1.
G
D
A
E
F
D
2.
Fig. 138. Nos. 1 and 2, cupelling or enamelling furnace. In both ▲ is the ash-
pit, c the fire-bars, D the muffle, в the opening for introducing the muffle, F the
chimney, and G the cover.
Cupellation is an operation not often performed by amateurs, chiefly
on account of the difficulty in doing it, unless provided with furnaces
built expressly for the purpose. The following plan affords the most
accurate results, while it may be performed in any furnace. The mouths
of two black-lead crucibles of the same size are to be ground flat, so
that, when applied one to the other, they may stand quite steady. An
oblong or semicircular notch is to be cut out of the mouth of one of the
crucibles, and a hole is also to be drilled through its bottom. This
224
SILVER.
crucible, when placed upon the top of the other, constitutes the muffle,
and of course resembles in shape a skittle. To cupel with this appa-
ratus, the lower crucible is nearly filled with clean sand, set upon the
bars of the grate in the centre of the furnace, and brought to a low
red heat. The cupel containing the lead and the alloy is then placed
upon the sand, and immediately covered by the other crucible, taking
care that the notch in its side shall be opposite to and correspond with
the furnace door; more fuel is added, during which it is well to cover
the hole in the top of the muffle with a crucible lid, in order to prevent
the admission of dirt. When the muffle has become throughout of a
bright red heat, the furnace door is thrown open, and the ignited fuel
gently moved aside, so as to permit a view of the side opening in the
muffle. The current of air which is thus established through the muffle
instantly causes rapid oxidation of the lead; and this may be regulated
at pleasure by closing the door more or less. If, from the fuel falling
down, any difficulty should be experienced in maintaining a free passage
of air, a portion of a porcelain tube or a gun-barrel may be passed
through the furnace door to within an inch of the muffle; but this pro-
ceeding is generally rendered quite unnecessary by taking care to place
C
A
·E-
D
Fig. 139. A B. Black-lead crucible. c. The upper
opening. D. The lower opening. B. The cupel.
The dotted semicircle represents the position of the
furnace door.
some large pieces of coke
immediately around the door
of the furnace. In many cases
it will be found advantageous
to convert the lower crucible
itself into the cupel by first
half filling it with sand, and
then ramming in pounded
bone earth. I have found
the above method to possess
the following advantages. In
the first place, the crucible
may be maintained at a much
higher temperature than can
be readily obtained when the
ordinary muffle is used, while
the degree of heat and the
quantity of air admitted may
be regulated with the greatest
nicety. Secondly, owing to

the greater draught of air, the oxidation of the lead is more quickly
effected; and, lastly, by looking through an opening in the furnace-cover,
the operation may be watched from first to last."
Second Series.
Silver is separated from gold and platinum by dissolving it in nitric
acid, which does not attack either of the other metals; the solution of
nitrate of silver, after careful filtration, is precipitated with one of
EXPERIMENTS WITH SILVER.
225
chloride of sodium, and the chloride of silver is thoroughly washed with
boiling water, dried, and mixed with black resin in the proportion of
three parts chloride of silver to one part resin; a gentle heat is applied
at first, when the hydrogen of the resin unites with the chlorine of the
chloride of silver, and a green flame is produced from the hydrochloric
acid formed by their union. The heat of the furnace is gradually in-
creased so as to afford a temperature of 1223° (Daniell's pyrometer)
the melting point of silver, and after tapping the crucible to shake down
the finely-divided silver, and adding some borax, a button of pure silver
is obtained, after the crucible is taken out, cooled, and broken.
Third Series.
Chloride of silver, when fused in a little porcelain cup, or allowed to
cool, forms a tough, hard substance, called by the old alchemists "horn
silver." This hard substance is difficult to remove from the porcelain
vessel, but may at any time be decomposed and reduced to the metallic
state by placing it in contact with some fragments of zinc and a few
drops of sulphuric acid, when a beautiful arborescent formation of silver
occurs, the particles interlacing with each other in the most curious
manner. If the chloride of silver has not been fused, the decom-
position by zinc occurs much more rapidly; and indeed this simple
process should be borne in mind by all photographers who use large
quantities of nitrate of silver. When the plates are placed on the deve-
loping stand, all the excess of the solution of nitrate of silver with the
acetic acid and other matters should be allowed to run into a stone jar con-
taining fragments of zinc; and at leisure times the metallic silver may
be collected, digested with some dilute sulphuric acid, washed and dried
in the oven, and will go a considerable way towards the purchase of
fresh nitrate of silver.

C
B
Fig. 140. A B. The gutta-percha trough and pipe leading to the stone jar cu
taining zinc. c, c. Two glass plates leveiled on the top of the trough, to carry the
glass plates for developing.
226
SILVER.
Fourth Series.
Silver is easily dissolved by dilute or strong nitric acid. Boiling
strong hydrochloric acid very slowly attacks finely-divided silver, which
it converts into chloride; the latter is partly dissolved, and is precipi-
tated again on the addition of water. Concentrated boiling sulphuric
acid oxidizes and dissolves silver, and is sometimes used in the arts for
the purpose of conferring a peculiar surface on the silver called oxidized
silver; the same result, however, is much more rapidly and expeditiously
brought about by the agency of the voltaic battery.
Fifth Series.
There are three oxides of silver-
The suboxide of silver
The oxide of silver
The binoxide of siver .
Symb.
Ag₂0=224.2
AgO=116·1
AgO, 124.1
Eq.
The most important and useful of the three oxides is the oxide of
silver, AgO, which is easily prepared by the mixture of hot solutions of
nitrate of silver and caustic potash, until the latter is shown to be
slightly in excess on testing with turmeric paper. The precipitate
is then well washed with boiling water, and when dried at 140° Fah.,
is a dark-brown powder, containing one equivalent of silver and one of
oxygen.
Sixth Series.
When a solution of nitrate of silver is precipitated by one of potash,
and the moist and recently prepared oxide digested with a little ammonia
for some hours, there remains a dark-black powder, and a considerable
proportion of the oxide of silver is dissolved. The black powder may
be placed in very minute quantities on separate pieces of blotting-paper,
and dried, and is, in fact, that most dangerous compound of silver
called fulminating silver, and supposed to be a nitride of silver consisting
of three equivalents of metal to one of nitrogen. The author does not
recommend the manufacture of these dangerous fulminating compounds,
and has only described the mode of making the fulminating silver
because amateurs, when making experiments in photography, sometimes.
put together very odd mixtures, and unwittingly prepare fulminating
silver, which, exploding when wholly unexpected, produces the most
lamentable results. Crackers, which the police object to so much on
the Derby Day, are sometimes made with this compound.
Seventh Series.
Silver remains perfectly bright in an atmosphere which is quite free
from sulphuretted hydrogen; consequently, silver plate is kept clean.
longer in the country than in London. Silver ornaments, such as silver
girdles and tassels, retain their brilliancy for any length of time if
placed in a clean, dry, and well-stoppered bottle. The ordinary black-
EXPERIMENTS WITH SILVER.
227
ness or film of sulphide of silver is soon removed from silver plate by
a little solution of cyanide of potassium, which, in conjunction with
whiting, is an excellent mixture for cleaning silver plate, and much
better than the mercurialized chalk or ordinary plate powder. The
bottle containing the cyanide of potassium should be labelled "poison."
Eighth Series.
Ordinary marking ink is prepared by dissolving two drachms of fused
nitrate of silver in six drachms of distilled water, and then adding to
the solution of nitrate of silver two fluid drachms of thick mucilage of
gum arabic. The linen or other fabric is prepared with a mordant
composed of a solution of half an ounce of washing soda (carbonate
of soda) in four ounces of water, and half a fluid ounce of thick muci-
lage of gum arabic, called the preparation. Writing with the marking
ink is rendered more legible by the addition of a little finely-powdered
charcoal or Indian ink; and to form a distinct writing upon cloth, it is
necessary to carry all the strokes of the pen downwards, and the pen
should have a short and stiff nib.
Ninth Series.
Silver is obtained in the metallic state from the chloride by pro-
cesses already explained at p. 225. The silver tree, or Arbor
Dianæ, so called, was originally devised by Lemery, and the following
is his process: Dissolve one part of silver in dilute nitric acid. Di-
lute the solution further with twenty
times its volume of distilled water, and
add to it two measures of mercury. In
about forty days the arborescent pre-
cipitate takes place. Homberg recom-
mends the preparation of an amalgam
of four parts of silver and ten of mer-
cury, which is to be dissolved in nitric
acid, and diluted with water equal to
thirty-two times the weight of the
metal employed; a lump of the same
amalgam is then to be placed in the
bottle, when the precipitation of silver
very rapidly commences, and assumes
the arborescent form. The same ef-
fect is produced by putting a soft amal-
gam of silver into six parts of a solu-
tion of nitrate of silver mixed with four
of a solution of mercury. When these
precipitations are conducted in one of
the glass globes used by engravers for
concentrating light upon their work,
the effect of the arborescence is very

Fig. 141. Engraver's Globe, with Arbo-
rescent Precipitate of Silver. The globe,
of course, must be entirely filled with
the solution.
Q 2
228
SILVER.
pretty. In this experiment a voltaic action is set up, the acid and
oxygen passing to the mercury, whilst the hydrogen travels to the
silver, deoxidizes, and gradually precipitates it in the metallic state.
A polished strip of ivory soaked in a dilute solution of nitrate of silver
until it acquires a yellow colour, and then taken out and immersed in a
tumbler of distilled water, whilst exposed to the action of the sun's rays,
turns black in the course of two or three days. If taken out, dried, and
rubbed, the black surface soon changes to a bright one of metallic
silver. A stick of clean phosphorus immersed in a solution of nitrate
of silver is gradually covered with fine dendritic or arborescent crystals
of metallic silver; the phosphorus deoxidizes the solution. Mr. John
Spiller, of the War Department, Woolwich Laboratory, has made some
important experiments on the composition of the film deposited by the
action of light and deoxidizing agents on the surface of glass and paper
used for photographic purposes.
Tenth Series.
Silver unites with chlorine, iodine, bromine, and fluorine, forming the
chloride, bromide, iodide, and fluoride of silver. The chloride is easily
prepared by the addition of a solution of common salt, or some dilute
hydrochloric acid to a solution of nitrate of silver. A white curdy pre-
cipitate is thrown down, which must be allowed to settle, and may theu
be washed by repeated decantation. It always settles better after the
addition of some nitric acid.
In the "Boy's Playbook of Science" the use of chloride of silver,
in the preparation of "photogenic" or copying paper, has been described
in the article on photography. Light changes the white chloride of
silver to a violet, which finally becomes black. This change occurs
much more rapidly in the presence of organic matter. Chloride of
silver is completely insoluble in water and in nitric acid; boiling strong
hydrochloric acid will dissolve a small portion, which it deposits in
minute octohedral crystals when carefully evaporated. The addition of
water to the latter solution likewise causes a precipitate of the chloride
of silver. Boiling-hot solutions of caustic potash and soda decompose,
whilst cold dilute solutions have no effect upon the chloride. A solution
of ammonia, however, rapidly dissolves it.
The chloride of silver has the curious property of absorbing one
equivalent and a half of dry ammoniacal gas; heat is evolved, and, when
saturated, the chloride gives up the ammonia rapidly on the application
of a gentle heat, such as that of the hand; and if a thermometer is
surrounded with it, the fall in the temperature is very apparent. The
chloride of silver saturated with dry ammoniacal gas may be employed
to illustrate the liquefaction of the latter gas, by placing some of the
compound in a bent tough glass tube hermetically sealed; on gently
heating the extremity where the chloride is placed, and surrounding the
other end with ice, the ammonia is driven off and liquefied. When the
heat is withdrawn, the gas is again absorbed by the chloride of silver,
which rises to a temperature of 100° Fah. during the absorption and
EXPERIMENTS WITH SILVER.
229
condensation of the ammoniacal gas. Chloride of silver dissolves
quickly in solutions of hyposulphite of soda and cyanide of potas-

Fig. 142. The Liquefaction of Ammoniacal Gas. A. Extremity of the bent-glass
tube containing the chloride of silver saturated win dry ammoniacal gas, and
placed in a copper pan containing water, and gently heated by the spirit-lamp
below. D. The other end of the tube surrounded with ice, where the liquefaction
of the gas takes place by its own pressure and the cold.
sium, and forms a cyanide which may be employed for silvering; it
also dissolves in a solution of chloride of sodium and in other chlorides,
forming double compounds. The presence of nitric acid appears to
prevent their formation, and hence the addition of nitric acid after the
precipitation of the chloride with nitrate of silver. At a temperature of
500° Fah. the chloride fuses, and when cold, solidifies into a tough mass
somewhat like horn; and hence its ancient name of "horn silver."
The reduction of chloride of silver to the metallic state has already
been explained in the third experiment, p. 225. A solution of ni-
trate of silver is precipitated by one of bromide of potassium, forming
the bromide of silver (AgBr). It very much resembles the chloride,
from which it may be distinguished by its lesser solubility in ammonia,
also by the disengagement of bromine vapour when heated in an atmo-
sphere of chlorine, which of course has no action upon the chloride of
silver.
When crystals of iodide of potassium are added to a solution of
nitrate of silver, the iodide of silver (AgI) is produced of a yellow
colour, and soluble in an excess of iodide of potassium; it is usual to
add the crystals of iodide of potassium to the nitrate of silver until the
yellow precipitate formed is redissolved. This solution precipitates
iodide of silver when diluted with water, and is used in the preparation
of Talbot's iodized paper, or rather iodide of silver paper, which is first
wetted with it, and then dipped in water; the latter causes the precipi-
tation of the iodide of silver on the surface of the paper by the dilution
of the concentrated solution of iodide of potassium.
Iodide of silver is almost insoluble in ammonia, and is readily distin-
guished from the chloride by its colour, its permanence in the presence
of light, and the violet fumes of iodine it evolves when decomposed by
chlorine gas.
230
SILVER.
Eleventh Series.
Electro-silvering may be conducted precisely in the same manner as
the gilding processes described in experiments pp. 204-5, substi-
tuting, of course, silver for the gold leaf or foil. On the small scale,
a silvering solution is rapidly prepared by dissolving a threepenny piece
in a little nitric acid contained in a test tube: the solution is poured into
a mug containing some dilute hydrochloric acid or solution of salt,
and, after being allowed to settle, the precipitated chloride is washed
several times with boiling water. The moist chloride of silver is then
dissolved in a solution of cyanide of potassium, and placed in a small

B
A
D
Р
C
N
M
உ
Fig. 143. A. The test tube containing the threepenny piece and nitric acid.
B. Mug containing boiling water with a small quantity of hydrochloric acid. c. The
gallipot with bowl of tobacco-pipe set upright in plaster of Paris (P P), and con-
taining the dilute sulphuric acid and zinc (z). D D. Solution of silver surrounding
the bowl of the tobacco-pipe, and containing the article to be silvered (M).
gallipot containing the bowl of a tobacco-pipe fixed in with plaster of
Paris, so that the latter completely stops the little tube or opening com-
municating with the stem, and at the same time keeps it upright. The
bowl of the pipe may contain water mixed with three or four drops of sul-
phuric acid, and a bit of amalgamated zinc being placed therein and
attached to a wire connected with a clean copper or brass article, it is
instantaneously silvered when immersed in the solution of the chloride
of silver in cyanide of potassium.
EXPERIMENTS WITH SILVER.
Twelfth Series.
231
Silver is easily removed from worn or injured plated goods by the
following solution: Oil of vitriol, together with five per cent. of nitrate
of soda, is heated in a cast-iron boiler, or, better, a stoneware pan, to
212° Fah. The silver-plated article, after being carefully freed from
grease by immersion in a boiling solution of carbonate of soda, is then
attached to an iron wire and held in the acid solution until the silver is
removed; it may then be taken out and well washed under a tap of
water.
Thirteenth Series.
Mr. Thomas's Formula for the Preparation of the Nitrate of Silver Bath
for Collodion Plates.-Into a 20-oz. stoppered bottle put nitrate of silver
14 ounces, distilled water, 4 ounces-dissolve. To this solution add
iodide of potassium, 4 grains, dissolved in 1 drachm of distilled water.
Mix these two solutions; the precipitate (iodide of silver) thus formed is,
by shaking, entirely dissolved. Add 16 ounces of distilled water, when
the excess of iodide of silver is again thrown down, but in such a finely
divided state as to render the saturation of the bath with iodide of silver
perfect. Now drop in sufficient of the oxide of silver to turn the turbid
yellow solution a dirty brown colour; so long as this effect is produced,
the quantity of oxide of silver, however much in excess, is of no con-
sequence; shake the bottle well for 10 minutes or so at intervals, then
add alcohol, 30 minims, and filter; to the filtered solution add dilute
nitric acid of the strength stated, 5 minims. The bath is now ready for
use, and should be quite neutral.
Fourteenth Series.
Silver is detected by the following tests: Solutions of silver are
precipitated by hydrochloric acid, forming the chloride of silver, which
blackens by exposure to light, especially when mixed with a little gallic
acid. The chloride is soluble in ammonia, and is reduced by zinc to
the metallic state. The precipitated silver may be collected, washed
with dilute sulphuric acid, and finally with boiling water; collected,
dried, and fused by the blowpipe with borax into a little button of silver.
The little button of silver may be dissolved in nitric acid, and portions
of the solution tested on slips of glass with hydrochloric acid and am-
monia. Sulphuretted hydrogen or a solution of hydrosulphuret of
ammonia precipitates the black sulphuret of silver insoluble in dilute
acids, alkalies, alkaline sulphurets, and cyanide of potassium. A solu-
tion of iodide of potassium precipitates the yellow iodide of silver
soluble in excess of concentrated solution of iodide of potassium.
Potash and ammonia precipitate the oxide of silver soluble in the latter,
but insoluble in the former. It will be evident that solutions of hydro-
chloric acid and ammonia afford the most characteristic results with
232
SILVER.
solutions containing the metal silver; and although the chlorides of
lead and mercury are precipitated by hydrochloric acid, they are readily
distinguished from silver by other tests explained in the respective
chapters on these metals.

Fig. 144. Elaborate Work of Art in Silver, by Hunt and Roskell; the lid is
removed when the vase is to contain flowers.

Fig. 145. The Planet Saturn.
CHAPTER VI.
LEAD.
h
The character is supposed to represent the scythe of Saturn, “Old Time.”
WE are reminded by the cut at the head of this chapter that Saturn
was the ancient name given by the old alchemists to this element, and
as the properties of the metals known to the ancients will first engage
our attention, we may proceed with the enumeration of those belonging
to lead, because it is so intimately connected, in its natural or mine-
ralized state, with the noble metal, silver.
Lead has been known from the most ancient times, both in the
metallic and combined state. Ever since the time of Moses (and how
long a time before that period it is difficult to say) lead has been in
use, and has continued in use from that time till the present day. It
is stated that the Romans sheathed the bottoms of their ships with lead,
and fastened it on with bronze nails, whilst the Roman ladies, like some
silly females of our own day, used the carbonate of lead, or white-lead,
for a cosmetic. The use of "face powders" is fortunately rather the
exception than the rule, sensible people being generally content to wash
234
LEAD.
their faces; and young persons cannot be too careful in avoiding the
use of such things, as they sometimes cause paralysis, and the counte-
nance is distorted by the involuntary twitching of the facial muscles.
The oxides of lead are used as pigments, and also in the manufacture of
the finest glass. The acetate, or sugar of lead, is likewise employed
for various useful purposes, and especially in dyeing and the preparation
of certain pigments. Lead has not only a bad reputation for producing
"the plumber's colic," when gradually absorbed into the system, but its
poisonous qualities have been unwittingly demonstrated by those unfortu-
nate persons who have swallowed wine sweetened with poisonous acetate
of lead (formerly much used by wine merchants for preserving wines from
acidity), or by children who have partaken of "lollypops" coloured with
red-lead, or eaten "Bath buns," as Dr. Griffin of Bristol has proved,
rendered more fatal by sulphide of arsenic, mistaken for chromate of
lead or chrome yellow. The alloys of lead are very important, and their
composition is stated in the experiments with this metal.
Nearly all the lead of commerce is obtained from a mineral called
galena," or "lead-glance," being a sulphuret of lead (PbS), and
diffused through (more or less) vein-stone or "gangue," a word derived
from the German gang, a vein. When pure, every 100 parts of galena
are composed of lead 86.55, sulphur 13.45.
CC
""
In the chapter on coal it has been explained that, by the disturbance
of the original layers or strata of rock and coal, they are brought nearer
the surface of the earth, and are discovered in positions they would not
otherwise have held. The same observation applies to minerals such as
lead ore, which has undoubtedly been deposited in the metamorphic
rocks, such as clay-slate, quartz rock, &c., and therefore very low in the
order of deposition; but the same convulsions of nature which have
thrown up the coal have performed a similar benevolent office for the
useful minerals, which are thus brought within the reach of the indus-
trious hands of man. When the geological survey of a country leads to
the supposition that minerals are present, the miner does not speak of
boring” and “winning," as he would do if he were searching for coal,
but uses other terms, such as "exploring," "shoading," and "costeaning,
and he terms the rock in which the mineral is deposited the " country,
whilst the mineral itself is distinguished as the "lode."
In a
mountainous or hilly region, a "lode" or metallic vein may "out-crop"
or come to the surface of the earth; but then centuries will probably
have elapsed since the event occurred, and by the time the country is
explored, great changes of the surface will have been brought about, so
that, by the action of water, particles of the lode will be carried a great
distance from the locality to which they originally belonged, and the
lode itself be completely hidden by the alluvial cover. The Cornish miners
have always been celebrated as keen observers of nature, and, like the
Red Indians of America, can take up and follow a "mineral trail" with
the most unerring precision. When they endeavour to trace the mineral
particles discoverable in the lower levels to their source, it is called
shoading," and the water-worn and rounded bit of mineral is termed
SHOADING AND SHOAD STONES.
235
a shoad-stone. "Costeaning" is analogous to the "boring" for coal; and
a number of pits, like churchyard graves, are sunk in places where the

B
Fig. 146. Section of Hill containing the Mineral Lode a B. The figures below are
supposed to represent the miners "shoading" and tracking the shoad stones from
the bed of the river flowing at the base of the hill to their source at the "broil,"
or head of the vein at ▲. It is seldom that a mine is opened from the surface or
grass.
mineral is supposed to exist. The holes or pits are sunk near each other,
and at right angles, or nearly so, to the supposed direction of the lode,
and in order that no mineral may escape discovery, the pits are con-
nected together by "cross-cuts" below. The science of geology no
doubt is of great value in preventing foolish schemes for mining dis-
tricts where no minerals exist; but it is evident that nature is continually
at variance with scientific prognostications, or else the shares of mines
would not fluctuate so fearfully in the market. Any man who could
examine and determine the probable mineral riches of a mine would
make a rapid fortune by speculating in shares; but this kind of know-
ledge has never yet proved infallible, and, like the diagnosis and pro-
gnosis of the physician, is frequently right, but very often wrong, because
the human body, and the rocks, happen to be both opaque and return
no direct answer to the prying eyes of the observer.
In a mining
district every well sunk or hole dug is examined with the sharpest
scrutiny; and when minerals are discovered, the next thing to be done
is to drive an adit or horizontal entrance into the rocks, provided the
conformation of the country admits of it. The adit level has already
been described in the article on coal at p. 52, for the purpose of
showing the most simple method of draining a mine, and is repeated
here in another picture taken from George Agricola's practical work on
mining, which is probably one of the most complete books ever written
on the subject; and when it is considered that the work is more than
three hundred years old, the reader will marvel at the careful practical
observations of the ancient miners, and how little they allowed to escape
them. This old book contains nearly everything, except the use of the
236
LEAD.
steam-engine, that might be found in a modern treatise on mining opera-
tions.

A
D
H
ס
M
K
"'!!
2
Fig. 147. The Adit Level. A, A. Two uprights or yokes supporting a bearer B B.
c. The well, pit, or shaft. D. First cord. E. Weight of the first cord. F. The
second cord, fixed to the earth at G. H. Head or ends of cords. I I. The mouth
or entrance of the adit or tunnel. K. The third cord, with weight attached, L. M.
The first measure; N, the second; o, the third, forming the triangle P. (Agricola.)
In the above cut the miner, or the person corresponding with the
modern superintendent or captain, is making out the course along which
the tunnel or adit is to be driven in order to meet the shaft. At the
present day, great credit is due to the captains, who, by carefully dialling
the ground with the assistance of a theodolite mounted over an ordinary
mariner's compass, direct the underground work of the miners with the
greatest precision, so that they may even excavate the different portions
THE TAMAR LEAD MINE.
237
of a shaft independently, one under the other, which shall form a perpen-
dicular pit when united together.
During a leisure month the author visited the famous Tamar lead-
silver mine near Beer Ferrers, on the banks of the river Tamar in De-
vonshire; and having an introduction to the "captain" of the mine,
was enabled by his courtesy to see the whole of these interesting works.
Like the labourers in the coal pits, every class of persons engaged has
its peculiar title, which appears, in mineral mines, to be in some degree
borrowed from the sailors, as the head business man is styled the
"purser," and under him is the agent called "captain," who likewise has
subordinates, termed “underground" and "grass" captains; the latter
superintends the preparation, cleaning, or dressing of the ore, and the
other works on the surface; the former looks after the pumps and at-
tends to the timbering of the chambers, galleries, shafts, and the general
works underground. The miners are classed in two great divisions, viz.,
the underground and surface men. The underground miners are sub-
divided into tutmen and tributers. The former, as it were, cut the
underground road by sinking the shafts and excavating the adits and
galleries, and the latter, using the path dug out by the tutmen, under-
take to find and bring the ore to the surface. The tributers are specu-
lators or adventurers, and the greater part of the money they earn,
except the sist money, is derived from a per-centage on the value of the
ore after it is prepared for market; and as this may vary, according to
the mineral, from 6d. to 13s. 4d. in the pound, the fascination of this
game of chance is very great. The surface men attend to the water- or
steam-engines, and also to the different kinds of machinery used in dress-
ing the ore for market; and whether surface or underground men, their
lives are passed in a continual round of hard labour. The number of
persons employed in the mining districts of Devonshire and Cornwall
has been estimated at about 30,000.
Having been duly equipped in miner's costume-a flannel shirt and
trousers, worn close to the skin, in order to afford a porous medium for
the escape of the perspiration, a pair of thick shoes, a linen cap, and a
stout broad-brimmed hat with a lump of clay in front to hold the lighted
candle-the visitor starts on his dismal route. The bustle and excite-
ment which prevail at the mouth of a coal pit are not observed at the
brink of a mineral one. The traveller commences his weary journey at
once by clinging to the ladder and slowly descending, taking rest occa-
sionally upon the stages which occur about every three fathoms, and
probably thinking of the hard work he will have to go through before
he reaches the summit again and once more breathes fresh air; indeed,
the downward journey must not be attempted unless the visitor is sure
of his physical powers being equal to the exertion required. Nothing
can be more dismal or melancholy than the inside of a mineral mine.
Writers of fiction may indulge in dreams of glittering ores bestudded
with flashing jewels only waiting to be grasped by the avaricious hands
of man, but stern reality is directly opposed to these poetical fancies; and
although occasionally a great mass of glittering galena, or sulphuret of
238
LEAD.
lead, may suddenly reward the toil of the miner and cause the shares of
the mine to give a spasmodic jump upwards, it rarely lasts, and perhaps
is only the forerunner of a greater scarcity of the mineral. The visitor
continues to descend through fathoms of rock, and the only noise he
hears is caused by the up and down movement of the long rods of the
pumping gear, or the occasionally scraping and grating of the buckets
or kibbles containing the ore against the sides of the shaft. At last a

C
B
NOL


D
Fig. 148. Descent of a Mineral Mine. A B. A portion of the shaft, being a paral-
lelogram about twelve feet by six,and divided in the centre; one division being
for the use of the miner c, and the other for raising the ore in the iron basket or
kibble D.
level is reached, and, with body bent, and in Indian file (for the levels
are generally so narrow that they admit the passage of one person only
at a time), the visitor almost starts when he comes suddenly upon a
solitary miner digging out dirty-looking lumps of lead ore with bright
shining speckles in them, which he is told is valuable, because it con-
tains so many ounces of silver to the ton, and can by Pattinson's pro-
cess be refined and the precious metal separated from the less valuable
lead. The most brilliant and purest galena generally contains the least
silver, and especially when it occurs in great bulk; but small forks,
branches, and veins of galena ramified in a stratified rock, generally
contain the most silver. A lead miner is glad to meet with galena in
a limestone rock, because the vein is usually large; but his enthusiasm
is checked when he discovers that it passes into sandstone, and espe-
cially when it enters shale or slate, for then it becomes a mere thread,
or the ore disappears altogether. The mineral vein being reached, is
usually found to slant or underlie to the right or left in the solid rock,
passing downwards to a considerable depth. It is different from a seam
of coal, which is one of the earth's strata, and can therefore be traced
over a large area; whereas a mineral lode is a mere fissure or crack in
the strata filled with a variety of mineral substances, such as carbonate
of lime, or crystallized silica, or quartz, or fluor spar, and containing
lead, tin, or copper, or other metallic ores. The probable riches of a
coal field may be estimated with amazing accuracy, because it is an
actual stratum of the earth, however disturbed it may have been since
DOWN IN A LEAD MINE.
239
its deposition; but there is no certainty with mineral veins, and what cor-
responds with the fault or trouble of the coal miner is exactly the locality
that may contain the rich vein of the mineral seeker. The lodes usually
take an easterly and westerly direction; but they are very capricious,
and may vary in thickness from that of a sheet of paper to thirty feet.
The foreign matter or rubbish associated with the mineral ore is
termed "deads;" and as the traveller passes down the beautiful river
Tamar, or journeys in other parts of Devon and Cornwall, he may trace
the progress of the underground work by the heaps of slaty poisonous
rubbish thrown up in rugged heaps, looking as if it was a deserted
railway embankment or other great engineering earthwork.
Having passed the solitary workman, the visitor will notice that a
large quantity of timber is required to support the roofs, and his guide
will probably tell him that under his feet there are two or three other
similar galleries; and coming to a great hole, round which he creeps
with some fear and trembling, he is informed that it is a "winze," or
perpendicular shaft, connecting the gallery through which he is walking,
with the one below. The "winze" (Fig. 149) is intended to assist the ven-
tilation of the mine, which is very imperfect and sluggish; so much so,
that the poor miners are continually suffering from diseases of the lungs;
and, although otherwise a strong, robust, and healthy class of men, they
gradually succumb to the effects produced by inhaling the poison of
their own breath mixed with the smoke and carbonic-acid gas from the
candles they are obliged to burn in their gloomy and badly-ventilated
mineral dungeons. The miners are quite aware of this state of things,
and are paid much higher wages when they work in mines where the
supply of air is known to be bad. It is a sad reflection on our law
makers that they do not make the ventilation of mineral mines compul-
sory, and that they permit men, for the sake of a little extra wages, to take
a slow poison that entails the penalty of consumption, which may be
transmitted to their children. Experienced mining engineers are agreed
that there is no reason why mineral mines of any importance should not
be ventilated like coal pits. Mineral mines might, whilst worked in
doubt or uncertainty, be allowed to escape the expense of ventilation;
but directly a certain tonnage of ore has been extracted, then the owner
ought to be compelled to give his miners air and ventilation like the
coal-pit proprietors. It has been stated that the extra wages paid to
miners who undergo the risks attendant upon breathing an atmosphere
almost as bad as that of the Black Hole of Calcutta, would be amply
sufficient to pay for the cost of ventilation. A mine is usually divided
by the galleries and winzes into compartments about thirty-three feet
long and sixty feet high, called "pitches," which are let by "Dutch
auction" to the three or four miners for two months. Both the pro-
prietor and workman are benefited by short leases, as there is no game
of chance more uncertain than that of mining. A rich vein will sud-
denly melt away, not into thin air, but into profitless rubbish, having, as
the Cornishmen call it, "taken a heave;" having, in fact, been dis-
placed by some subterranean freak of nature, and either gone up or
240
LEAD.
down to delight the "tributers" and "adventurers" working other
pitches." Sometimes, when a lode is profitable, it "takes horse," being
divided by another lode not of valuable mineral ore, but of "deads,"

D
A
B
1 โน,
F
A B. Main shaft.
Fig. 149.
CB. Gallery heavily timbered. D. Shaft connecting the
galleries with each other, called a winze. B F. Gallery timbered. (Agricola.)
}
DOWN IN A LEAD MINE.
241
such as clay slate, called "fluckans," which throws the lode out of its na-
tural position, and gives the poor miners much harder work to secure.
Should a miner become quite disheartened with his "pitch," he may
resign it on payment of a fine of twenty shillings. Indeed, profit and
loss seem to be equitably proportioned amongst masters and men; and
the "strikes," which are so much to be deplored in certain coal dis-
tricts, are hardly known amongst the intelligent hard working Cornish
miners.
If the visitor is not already too much fatigued with his monotonous
journey, he may continue slowly descending from gallery to gallery until
he is informed that the river Tamar flows above his head, and that the
surface of the water is about 220 fathoms distant from the place where
he stands, or rather stoops. The miners actually penetrated to this
depth below the water; and as the river was broad at that part, and
they could not excavate air shafts, the works were abandoned for a
time until they boldly commenced an inclined plane, beginning at a
point about 100 yards below the top of the main shaft. This gallery
was driven at an angle of 37° right through the old workings to a
depth of 320 yards, and, at the suggestion of Dr. Spurgin, one of the
most scientific and liberal-minded men at the Royal Polytechnic Board

Fig. 150. Section of Tamar Lead Silver Mine, Beerferrers, Devon. A. Inclined
plane, leading to workings and underground shaft. B. Entrance to inclined plane.
o. The "Spurgin" shaft. D. The flue of the underground engine, two miles long.
B. Slides in the ore.
R
242
LEAD.
of Direction, a twenty horse-power steam-engine was erected at the 145
fathom level, or 290 yards below the pit's mouth, which answered the
purpose intended, viz., to pump water and raise the ore. The smoke
from the engine was conveyed along a flue running through the old
workings to the surface, and the shaft and engine were duly named after
the learned and spirited gentleman who had proposed them. The visitor
to the mines of Devon and Cornwall cannot fail to be struck with the
absence of those engineering arrangements which are a matter of course
at the coal mines of Newcastle and Durham.
Professor Hunt, the keeper of the Mining Records, informs us lead
mining appears to have been carried on in this country from a very early
period. When in the possession of the Romans, many of the lead mines
in Wales and England were worked, and considerable quantities of lead
obtained, as we may infer from the immense accumulation of slags in
Derbyshire, the Mendip Hills, and elsewhere. There does not appear
to have been any period in our history during which mining for lead was
not followed to some extent; but in the reigns of Henry VIII. and of
Queen Elizabeth, especially in the latter reign, a fresh impetus was
given to British mining by the introduction of a number of German
miners. That mining for lead must, previously to this, have been ex-
tensively carried out is proved by the circumstance that Edward the
Black Prince took several hundreds of the Derbyshire miners into
Devonshire, and it is said that the result of his mining speculations in
the west was the realization of wealth sufficient to defray the expenses
of his French wars.
If the amateur miner has experienced any fatigue during his progress,
he must make up his mind to forget that such a fact has been forced
upon his consideration; there is no friendly "corve" or empty coal
basket to convey him quickly to terra firma, and he must now com-
mence his laborious climbing upwards, which (if it does not bring on an
attack of cramp at once) is pretty sure to be remembered when bed-
time arrives, and the weary body is trying to sleep off the effects of a
descent into the Tamar lead silver mine.
Having reached the surface or "grass," there
grass," there is yet a great deal to
examine, and the visitor will pass in the next place to that part of the
works where the sorting and cleansing of the mineral ore take place,
as the galena is rarely in a sufficiently pure condition to be taken at
once to the roasting or smelting furnaces. After a considerable portion
of the useless earthy matters are removed, cither by "hand dressing" or
by the help of sieves constructed of iron wire, it is then sometimes
placed in other sieves and agitated in water, or it is washed like
po-
totoes by placing the lead ore in large troughs full of water and stirring
it with an iron shovel, called the standing buddle system; the latter
method, however, is not so perfect as the running buddle which is used
at the Tamar works, and involves the use of a more complicated arrange-
ment of inclined planes with flowing water, so that the ore is sorted and
cleansed in one complete series of operations. The similarity between
the ancient and modern operations employed to prepare the ores for the
1
SORTING AND CLEANSING LEAD ORES.
243
furnace, is again remarkably displayed in the curious work on the metals
by George Agricola, published more than three hundred years ago.

Fig. 151. Old Method of sorting and cleansing Mineral Ores. (Agricola.)
In the above picture, the use of the various sieves and water for
sorting and cleansing the ore is very clearly demonstrated, and the
arrangements correspond precisely in principle with those employed at
the present time. The next operation is the powdering of the ore,
which is either done with a crushing machine worked by a steam-
engine, such as that described and figured at p. 183, or by the more
ancient arrangement of stampers, which correspond with the pestle and
mortar used in cvery apothecary's shop for levigating small quantities
of hard substances. In George Agricola's famous work, the applica-
tion of different kinds of power, and especially water power, for working
the stampers, and performing the numerous mechanical duties of
mineral mines, is very carefully depicted and explained. In the next
cut it is apparent that an overshot water-wheel gives motion to an
axle, to which are attached cams; these strike upon the tongues fitted
on the stampers or upright strong wooden beams, shod with masses of
cast iron, and as these are alternately raised and allowed to fall they
gradually crush the mineral. The stampers generally work in a large
and stout wooden box, in which are openings fitted with gratings, and
when the mineral is powdered sufficiently fine, the stream of water
R 2
244
LEAD.
allowed to enter the box gradually carries it through the perforations of
the grating, and the powdered ore subsides or deposits in the pits or
tanks connected with the stamping box.

M
C
ふい
​Fig. 152. Stampers and Box with Pits to receive the powdered Ore, used more
than three hundred years ago. (Agricola,)
The main object of the stamper is to reduce the particles of the
mineral to one uniform state of division, so as to prepare them for the
succeeding operation of washing, performed with what is termed "the
nicking buddle," which is a long wooden box or trough, provided with
a shelf at the head, and gradually inclined towards the foot. The ore
is agitated by wooden shovels and implements somewhat like road-
scrapers, and as the water is constantly flowing through the box it gra-
dually carries off the lighter earthy matters or gangue, and leaves the
heavy mineral behind. By constant practice the Cornish boys manage
the agitation so well that the nearly pure and heaviest mineral is depo-
sited at the head of the box, in the next division is the mixture of ore
THE NICKING BUDDLE.
245
and some earthy matter, and the third contains the very fine and poorer
particles, which are further searched and winnowed from the associated
powdered rock by means of the "rack." The nicking buddle em-
ployed at the present time differs very slightly from that employed in
olden times, as will be noticed by the next interesting cut.

04/"
∞
Fig. 153. The "Nicking Buddle." (Agricola.)
The rack is (as its name implies) only a more searching arrangement
for the detection of the fine particles of mineral ore, and is used by
placing the ore on the shelf, to which water is then admitted, and by
constant but steady agitation with a hoe and birch broom, the dirt and
earthy dust are carried away, and the ore deposited on the floor of the
rack or cradle. For the convenience of removing the ore from the
floor of the "rack," the lower part is usually supported on an axis, by
which the table is moved into an upright position, or, as may be noticed in
George Agricola's picture (Fig. 154), it is simply rested against the wall,
and the finely powdered ore washed off into a pit below, divided into
one or more compartments corresponding with the divisions in the floor
of the rack, so that the most valuable mineral at the head is separated
from the lighter and less important mineral collected at the foot of the
246
LEAD.
יווויין.
rack; indeed, the whole of the washing operations conducted by the
nicking buddle and rack are based on the principle of the different
specific gravities of the pure and impure ore, the former being heavy,
whilst the latter is several degrees lighter by admixture with earthy
matters.

Fig. 154. "The Rack." (Agricola.)
After these mechanical operations are completed, the different quali-
ties of powdered ores are inixed together according to the results ob-
tained by a preliminary assay on the small scale, and being both roasted
and smelted in a reverberatory furnace, the galena or sulphuret of lead
is reduced to the metallic state.
The sulphur and lead which galena contains are in such proportions,
that when both are united with oxygen and converted, the one into
sulphuric acid and the other into yellow oxide of lead, the acid and oxide
exactly saturate each other and form sulphate of lead (PbO,SO,), hence
the object of the preliminary roasting, which is managed by spreading
the ore out equally on the hearth or bottom of the reverberatory fur-
nace, and the latter being already red-hot, communicates its heat to the
mineral, which is stirred about occasionally with an iron paddle in
order that the air may have free access to the sulphuret, and convert it
SIAMOMUNI
SMELTING LEAD ORES.
247
into sulphate of lead. Several reverberatory lead furnaces usually com-
municate with one main chimney, and this being enlarged into various
flues and chambers placed almost at right angles to each other, the lead
fumes volatilized during the process are in a great measure saved and
re-smelted. The loss of lead from volatilization is very considerable,
amounting to ten per cent. or more. Accordingly flues of great length,
sometimes exceeding a mile, are constructed in order to effect as com-
pletely as possible the condensation of the lead smoke or fume. Other
contrivances with the same view have been adopted; the smoke has
been caused to pass through water by means of powerful exhausting
pumps, or water has been projected in a finely divided state, like rain,
into chambers through which the smoke has been made to circulate;
and other methods have also been tried with greater or less success,
but all attended with no inconsiderable outlay. Mr. John Taylor, jun.,
has suggested a fundamental improvement in the smelting of lead ores,
and recommended the endeavour to effect the object at a temperature
lower than that required for the volatilization of the lead.
When the roasting has been continued for some time, the skimmings
of the lead obtained from the previous batch of ore smelted are thrown
into the furnace, and the whole well stirred together; and the lead ob-
tained at this stage of the process is run off at once from the taphole B

I
TRU QA BRINGING
G
E
H
WH
F
B
#!
QIMINU VINURAT DUNNURKISH ULU EM MAIEREN, MUTDUAN SHADDAINA HIND
MUTUANO CONTAS Kunnas mowa QUGINIE, COMAND
mmmma dimal q
Fig. 155. Section of the Reverberatory Furnace used for roasting and smelting
Galena. A. The hearth or sole of the furnace. B. Tap hole. E. The bridge which
separates the fire from the hearth upon which the ore is placed. F. The flue.
G. Hole through which the fuel is placed in the fire below. n, н, п. Openings,
closed by sliding iron plates, for the admission of air. 1. The hopper by which the
ore is passed into the furnace.
248
LEAD.
(Fig. 155). The fire is now reduced, and some quicklime thrown upon
the lead, the effect of which is to produce a silicate of lime, and it also
sets free a portion of oxide of lead. The fire is again raised, the lead
run off, and finally an excess of lime being added, the slags are then
made sufficiently solid to be easily removed, and directly one batch is
finished it is succeeded by another, so that the increased heat of the
furnace in the last operation, serves to bring the cold lead ore of the next
to the proper temperature required for the first operation of roasting.
The chemistry of the smelting process may be thus described:-
Sulphide of lead or galena (PbS) is partly converted by roasting into
sulphate of lead (PbŠO,), which, mixed with the undecomposed sulphide
of lead (PbS), produces two proportions of metallic lead (2 Pb), and
two proportions of sulphurous acid gas (2 SO₂).
The pigs of lead of course contain the silver, which may be separated
by Pattinson's process, in the manner already described in the article
Silver, p. 218.
Metallic lead has a bluish-white colour; and when recently cut,
melted, or scraped, presents a brilliant lustre, which rapidly fades, as the
metal, when exposed to the air, is converted into a suboxide of lead.
The softness of lead renders it extremely useful in the shape of wire
for horticultural purposes, whilst its well-known malleability enables it
to be applied in sheets for covering the roofs of houses; in both these
cases the length of time required to rust or oxidize lead renders these
applications of the metal of extreme value. One of the most interesting
modes of showing the softness of lead, is by placing a common seal of
sealing wax between two pieces of soft lead on an anvil, and striking
them suddenly with a tolerably heavy hammer, a correct impression of
the seal on the lead is obtained, from which other sealing wax im-
pressions may be taken, and it is said that this was the mode employed
by inquisitive post-office authorities in olden times, when they wished
to know the convents of a letter without betraying the fracture of the
seal.
The specific gravity of lead is somewhat high, being 11:445; it is
unelastic, not sonorous like many other metals, and the density appears
to be reduced instead of increased by hammering. It melts at about
635° Fah., and when exposed to a red heat with free access of air, it
smokes, sublimes, and affords a grey suboxide, which settles on any cold
surface. The effect of water upon lead has been carefully studied, and
it seems to be received as an axiom that pure water absolutely free from
air will not attack pure lead; distilled water, otherwise pure, but con-
taining a minute proportion of air in solution, gradually converts the
surface of a sheet of clean lead partly into white spangles of hy-
drated oxide of lead. The presence of ammonia in distilled water is
often overlooked, and, as shown by Medlock, is frequently the at-
tacking agent. It has been found that certain waters containing salts in
solution, and especially the sulphate of lime, do not dissolve lead, con-
sequently it was thought that hard waters might be safely conducted
through leaden pipes, whilst soft waters were considered dangerous
EFFECT OF WATER ON LEAD.
249
because they contain air in solution, which first oxidizes the lead and
forms oxide of lead, and this combining with the carbonic acid gas
which is always an ingredient of spring, river, and rain-waters, produces
carbonate of lead, commonly termed white-lead, and under these cir-
cumstances oxide of lead is found to be dissolved by the water. The
author recollects a very interesting case of lead-poisoning by water
passing through leaden pipes, which occurred many years ago, before the
action of water on lead was understood, and it came under the special
notice of the late Mr. John Thomas Cooper. This gentleman was
employed to visit an estate, for the purpose of ascertaining which of
three different springs of water was best adapted to supply the family
mansion. The softest water having been selected, it was duly conducted
by leaden pipes to the house, and the members of the family were loud
in their praises of the excellence of the choice, and nothing occurred to
cause any inconvenience to them until their return to the country after
the "London season," when nearly the whole of the inmates were seized
with violent cramps and other symptoms, which the local medical men
pronounced to be colic, and they recommended at once an analysis of the
water. On examination, it was found to contain an abundance of lead
in solution, and on taking up the pipe, they discovered several ounces
of white lead deposited in the interior, and especially where the pipe had
taken a bend or circuit through a valley. The action upon the lead no
doubt had commenced directly it was laid down and brought into use,
but as long as the family remained in their country house, the demand
for this precious necessary of life was so abundant, that it never stayed
long enough in contact with the lead to dissolve an appreciable quantity.
When, however, the family removed to London, the water was in less
demand, and moved more sluggisbly through the pipes, so that a large
quantity of white-lead was formed, and directly the consumption of the
water increased, the poisonous white-lead was swept into the cistern, and
being diffused mechanically through the water as well as being partly dis-
solved, it produced those dangerous results already mentioned. The cure
was somewhat expensive, and consisted in the removal of the lead-pipe
and cistern, and the substitution of stoneware and slate.
It appears that neither hard nor soft water is safe in leaden cisterns if
it contains organic matter in solution. This important fact has been
established by Dr. Medlock, and he is of opinion that if the dissolved
organic matter is allowed to remain in the water, it decomposes, attacks
the lead, and forms a soluble nitrite of lead; and he has further ascer-
tained that by exposing water which contains organic matter in solution
to the action of iron, it has no longer the power to dissolve lead, and
hence he has explained those otherwise apparent anomalies of some kinds
of soft water not attacking lead, whilst other hard water containing the
so-called protective salts dissolve lead freely. In the former case, the
water was free from organic matter; in the latter, the hard water con-
tained organic matter which produced the soluble nitrite of lead; there-
fore Dr. Medlock insists upon the freedom of water from soluble organic
matter which is to be stored in leaden cisterns. Lead is not only used
250
LEAD.
to cover the houses which shelter the living, but has also been employed
from time immemorial in the construction of the box or coffin to contain
the dead. Formerly no person could be buried in a vault under a church
except in a leaden coffin; the barbarous custom of putting the dead in
leaden cases that were liable to swell, burst, and throw out their deadly
gases into the church above containing the living, has now been abolished,
except in rare cases, when embalmed royalty, or the remains of some of
our greatest men are consigned to their last resting-places in Westminster
Abbey, St. Paul's, or the Chapel Royal, Windsor.
Mr. R. V. Tuson has made an interesting analysis of coffin-lead taken
from an old coffin which had lain in a vault, it is believed, for eighty
years, and obtained the following results. The pieces of lead were about
a quarter of an inch in thickness; they had a laminated structure, and
possessed a fawnish or dead-white colour. Neither crystalline form nor
metallic lead were detected, even by the aid of the microscope. The
material was tolerably brittle and readily reduced to an impalpable
powder. On submitting it to quantitative analysis, the following were
the results obtained:
Moisture
•
Organic matter and loss
Peroxide of iron
Oxide of lead
Carbonic acid
0.10
0-52
1.94
82.29
15.15
100.00
These results show that it chiefly consisted of proto-carbonate of lead,
with a small proportion of anhydrous protoxide. The interesting points
in connexion with this substance are, that it is anhydrous, that it con-
tains but a small excess of oxide, and that it consequently differs in com-
position from any of the carbonates of lead hitherto described as being
produced by the united action of air and water on metallic lead, or by
the influences concerned in the well-known Dutch method for manufac-
turing "white-lead." The difference in composition of the various
carbonates of lead formed under the circumstances referred to, will be
seen by glancing at the subjoined table:-
Source.
Air and water in lead.
Dutch method
Leaden coffins
•
•
Composition.
PbO, HO + PbO,CO,
PbO, IIO+ 2 (PbO,CO)
PbO, + 15 (PbO,CO₂)
The searching and exposure of the condition of the vaults of many
of our crowded churches by Mr. George Godwin, Mr. Walker, and other
gentlemen, has induced the sanitary authorities to order them to be closed
and filled with charcoal, and that this was absolutely necessary, is appa-
rent from the vignette at the end of this chapter (Fig. 159), which shows
the condition and number of coffins containing decomposing animal
matter stowed away under the ancient crypt of Bow Church, and called
a Christian burial.
ASSAY OF LEAD ORES.
251
EXPERIMENTS WITH LEAD.
First Series.
On
D
C
B
To make an assay of lead ore or galena, a fair average sample must
be selected, and after being powdered, 150 grains may be weighed
out and mixed with 230 grains of
black flux and 50 grains of moderate-
sized nails, and the whole placed in
a proper crucible, which is then to be
When
brought to a bright red heat.
the whole is in a perfectly liquid state,
the crucible may be removed, gently
tapped, and allowed to cool.
breaking the crucible with a hammer,
a button of lead will be found in the
lowest part, which may be flattened
out on the anvil, to remove any of
the adhering flux or parts of the iron
nails. The weight of the button of
lead determines the per-centage of the
metal in the ore, and to ensure accu-
racy, the assay should be repeated
three times, and the mean of the ex-
periments taken. The furnace and
crucible for this operation are shown
at Fig. 156, and Messrs. Griffin, of
Bunhill-row, Finsbury, make most
convenient portable furnaces for all
kinds of assays. The button of
lead may be subsequently cupelled,
and the number of ounces of silver
it contains per ton accurately deter-
mined.

A
Fig. 156. Common sheet-iron Furnace
lined with fire-clay, for ordinary metal-
lurgical operations not requiring an in-
tense heat. A. Ashpit and sliding dam-
per. B. Side hole, with door for fuel.
c. Cover lined with fire-clay and hole in
centre. D. Chimney.
Second Series.
A very instructive experiment, illustrating the reduction of a metal
from the state of oxide, is performed by mixing one ounce of litharge
or red lead with three of powdered cyanide of potassium, and placing
the whole in a crucible, which is then brought to a dull red heat in an
open charcoal brazier or common fire. The carbon of the cyanogen re-
moves the oxygen from the oxide of lead, and directly the whole is
properly fused, the slag may be carefully poured off into an iron shovel,
and the heavier lead into a greased mould (the top of a 1-lb.
brass weight is as good as anything), and then after being cooled in
water, may be hammered on the anvil to show the malleability of the
252
LEAD. ·
metal when the oxygen is separated from it. The powdered litharge is
a dust or powder that the wind from the bellows may blow away, but
deprived of the combined oxygen, a solid and heavy mass is obtained,
upon which the air from the bellows has no effect. The powdered
litharge preserves a dull ash-grey colour, but like the fabled phoenix
bird of old, it is revived by the action of fire and charcoal, and is
changed to brilliant and shining lead.
Third Series.
The reduction of lead to the metallic state and its subsequent oxida-
tion, can be displayed in another and more curious form by heating some
tartrate of lead in a glass tube about eight inches long and three-eighths
of an inch wide, closed at one end, and drawn out to an open capillary
tube at the other. The perfectly dry tartrate of lead should be placed
in separate lengths of the narrow glass tube, previously closed at one
end, and after its admission, the tube may be drawn out into an open
capillary tube at the other extremity, so that when heated over a wire-
gauze burner of gas and air, the capillary end may be hermetically
sealed, directly after the smoke has ceased to be evolved from the heated
tartrate of lead. When the tube is cold, and one end broken off with
a pair of nippers, the finely-divided lead takes fire as it is shaken out
into the air, forming litharge, which is very apparent when the tube
containing the pyrophoric lead is emptied into a tall jar containing oxygen
gas. That the effect is due to the oxidation of the metal is clearly de-
monstrated by shaking some of the contents of the tube into another
tall jar containing carbonic acid gas, when the spontaneous combustion
of the lead no longer occurs, and the yellow colour of the litharge is

N° 1
N° 2
C
C
A
BIO
Fig. 157. No. 1. Tube closed at one end, containing tartrate of lead. No. 2. vnto,
closed and drawn out to a capillary tube at A, and held over the mixed ga and air
flame obtained by allowing coal gas to escape gently from the cock B into the iron
cylinder c c, open at the bottom, and covered with wire gauze at the top, where the
mixture of gas and air burns.
EXPERIMENTS WITH LEAD.
253
not apparent on the sides of the jar containing the latter gas, whilst it
is very easily seen in the jar containing the oxygen.
The tartrate of lead is readily procured by precipitating a solution of
acetate of lead with one of tartaric acid previously neutralized, or nearly
so, with ammonia. The precipitate may be separated and washed with
water by decantation, or it may be collected on a cotton cloth filter,
washed with water, squeezed by hand or with a press, and finally dried
in an oven.
Fourth Series.
Pure lead is frequently required in the assay of gold or silver, and is
obtained by calcining pure nitrate of lead in a crucible, and then fusing
the residual oxide with charcoal, or, still better, with cyanide of potas-
sium, when a button of the pure metal is obtained.
Fifth Series.
Lead is deposited from a solution of acetate of lead in a very beauti-
ful crystalline metallic state, by placing in the solution a bar or rod of
zinc. The first effect of the latter is to take away a portion of the acid
and oxygen from the acetate of lead, and when a portion of the lead is
deposited on the zinc, the electro-chemical deposit proceeds slowly by the
action of the voltaic couple, and whilst the oxygen and acid pass to the
zinc which is dissolved, the lead assumes the solid state, and clings to
the remains of the rod of zinc, producing a pretty ornament, called the
lead or Saturn's Tree. An engraver's glass globe is well adapted to
show off this very brilliant and pretty deposit of lead.
Sixth Series.
On the small scale, the reduction of litharge or red lead to the me-
tallic state may be shown by mixing the latter with powdered coke or
charcoal, and placing it in the bowl of a tobacco-pipe, using the stem as
the handle. On the application of a dull red heat, the charcoal com-
bines with the oxygen of the litharge, and escapes as carbonic acid, and
the lead gradually collects at the bottom of the bowl, and may be poured
off into a mould or on damp sand. Lollypops suspected to contain lead
as the colouring pigment, may be treated in a similar manner, and
although it takes a longer time to burn off the excess of carbon, the
lead finally becomes apparent, either in minute globules diffused through
the mass of charcoal, or collected in a larger quantity at the bottom of
the bowl.
Seventh Series.
Lead unites with oxygen in various proportions, but the chief oxides
are the
Suboxide of lead
Oxide of lead
Binoxide of lead
Pb₂O
PbO
Pbo₂
254
LEAD.
The suboxide (Pb,O) is obtained by heating oxalate of lead in a greer
glass test tube, placed in an iron ladle containing melted lead (a lead bath),
until the whole of the carbonic acid and carbonic oxide gases are given
off. The lead bath should be maintained at a temperature just sufficient
to keep it from solidifying. Oxide of lead (PbO) in the fused state,
under the name of litharge, is prepared in the manner already described,
during the cupellation of lead for silver on the large scale. Oxide of
lead which has not been fused or heated, or only moderately so, presents
a lemon or orange yellow colour, and is called massicot. At a high red
heat the latter fuses, and if of a red colour from the presence of minium
or red lead, is called litharge of gold; but if paler, is termed litharge of
silver. The presence of sulphuret of antimony in minute proportions
imparts a dark hue to the litharge.
The binoxide of lead (PbO) may be prepared by digesting minium
with strong nitric acid. The acid and oxide must be constantly stirred,
and after a few days a dark brown powder is formed, from which the
acid solution of lead must be poured, and the whole well washed with
an abundance of boiling water, and the residual binoxide carefully
dried in a water bath. The operation is quickened by boiling the
nitric acid.
Common minium or red lead is prepared by exposing oxide of lead to
the action of a current of air heated to a temperature between 570°
Fah. and 580°. The finest and most brilliant minium is prepared by
exposing carbonate of lead to the action of a current of air heated to
about 600° Fah.
Eighth Series.
Chlorine, iodine, bromine, and fluorine unite with lead. The chloride
(PbCl) is prepared by precipitating a strong solution of acetate of lead
with hydrochloric acid or a solution of common salt; on boiling the solu-
tion the precipitate disappears, as 1 part of chloride of lead dissolves
in 135 parts of cold and 33 of boiling water; therefore, when cold, the
chloride of lead again deposits in beautiful crystals, and is called the
"silver shower."
"The golden shower," so called, is prepared by precipitating a solu-
tion of acetate of lead with one of iodide of potassium; on boiling the
mixed solution the iodide is redissolved, but again precipitates in
pretty shining yellow scales, as the flask containing the solution is per-
mitted to cool. The yellow precipitate is the iodide of lead (PbI).
The bromide of lead (PbBr) is prepared by adding a soluble bromide
to a solution of lead, and resembles the chloride in its colour and pro-
perties. Amongst the various pigments obtained from lead there is a
yellow colour called Paris, Mineral, Turner, or Cassel yellow, which is
an oxychloride of lead of a variable composition, according to the
manner of its preparation. When a solution of chloride of lead is de-
composed witli lime water the oxychloride is obtained, aud being dried
and calcined affords the yellow colour. If prepared by boiling with
water four ounces of litharge and one of common salt, the oxychloride
EXPERIMENTS WITH LEAD.
255
obtained is white, but assumes a yellow colour after calcination, and its
composition is represented by the next formula, PbCl,3PbO, HO.
Fluoride of lead (PbF) is obtained by adding hydrofluoric acid to a
solution of nitrate of lead, when it precipitates as a white powder, which
is almost insoluble in water.
Ninth Series.
Ceruse, white lead, or carbonate of lead (PbO,CO), is prepared in
enormous quantities for white paint. By precipitating a solution of
lead with carbonic acid or any alkaline carbonate, a carbonate of
lead is obtained which appears to have a semi-crystalline form, and is
not sufficiently dense and opaque, or has not sufficient body to cover the
work when used as paint, consequently the ceruse prepared by the old
Dutch methods is generally preferred. This process was introduced
into England in 1780, and is conducted with lead which is cast into
plates, bars, or grates, and arranged in conical earthen pots containing
about a gill of acetic acid, and placed in stacks surrounded with dung,
or, better still, with spent bark. The stack, contained within an oblong
brick chamber, is built up of alternate layers of dung or tan, the pots
containing the lead and acetic acid, boards, more dung or tan, and so on
till the stack contains about twelve thousand pots, and from fifty to
sixty tons of lead. The tan or dung gradually ferments, and attains a
temperature of about 140° or 150° Fah. in the central part of the stack,
and in the course of four or six weeks the lead increases in bulk, and
although retaining its form, is now converted into a dense basic car-
bonate of lead, having the formula of 2, sometimes 3 (PbO,CO₂)
PbO,HO. The affinity of lead, or rather, oxide of lead, for carbonic
acid, is very remarkable, and may be observed sometimes on the ex-
terior of leaden water pipes which pass near drains evolving carbonic
acid and other gases. Even near the ventilating door of a roof of any
public building covered with lead, when the foul air escapes and im-
pinges on the metal, the same change is observed, and when it once
begins, the attacking carbonic acid cuts like a cancer into the very body
of the lead. Sometimes white lead is adulterated with sulphate of
baryta, called Fenice white, but a very simple analysis will detect the
sophistication.
Tenth Series.
Other valuable pigments are obtained by the combination of chromic
acid with oxide of lead, which may be either yellow in the state of
neutral chromate of lead (PbO,CrO3), or a beautiful red, as bibasic
chromate of lead, 2 PbO,CrO,. The former is prepared by precipitating
a dilute solution of acetate of lead with one of chromate of potash, and
the addition of sulphate of lime to the commercial chromate is said to
improve the colour. The red dichromate is formed by digesting the
yellow chromate of iead in caustic potash, or still better by Liebig and
Wohler's process, in which the neutral chromate is added to melted
nitre, and when the red chrome has subsided the melted nitre above it
is poured off and the remaining mass quickly washed with water.
256
LEAD.
Eleventh Series.
All pigments containing lead must be preserved from contact with
sulphuretted hydrogen gas; white lead especially is peculiarly sensitive
to the presence of that gas, and hence the use of tan is preferred to
that of dung in making white lead, because of the sulphuretted hydrogen
sometimes emitted from manure in a state of fermentation. In the
neighbourhood of large gas works the paint of the houses is sometimes
strangely affected from the same cause, and the author has seen a
whole row of houses rejoicing in fresh paint and cleanly cheerfulness,
changed in the course of a few days to a most dismal and funereal
aspect by the sulphuretted hydrogen escaping from gas purifiers, which
have been carelessly emptied and their contents allowed to remain ex-
posed to the air.
Sulphide of lead (PbS) occurs plentifully in nature as an important
mineral, which has been already spoken of by the name of galena. It is
Sulphide of
LEAD
Fig. 158. Invisible Letters written with a solution
of lead becoming visible by holding to them a bottle
containing a few drops of sulphide of ammonium
well shaken in it to diffuse the vapour through the
air contained therein.
prepared artificially by melt-
ing sulphur with lead, or by
precipitating a solution of
acetate of lead with sulphu-
retted hydrogen gas, when
the sulphide presents a black
colour, or a deep brown if a
solution of sulphide of am-
monium is employed; and a
very marked result is obtained
by writing on a sheet of paper
the words sulphide of lead
with a solution of acetate of
lead mixed with some gly-
cerine to keep it damp; and
if a little sulphide of ammo-
nium is poured into a wide-
mouthed stoppered bottle and
shaken, so as to diffuse the
vapour through it, on remov-
ing the stopper and applying
the bottle to the letters, they
become visible immediately,
and change to a deep brown
colour, the lead being preci-
pitated as the sulphide.

The presence of sulphur
in albumen is easily shown by dissolving some white of egg in
a solution of caustic potash, and adding one of acetate of lead, as
long as the precipitate formed is redissolved. On boiling the solution it
instantly becomes black by the separation of sulphuret of lead, which
proves in a satisfactory manner the presence of free sulphur.
EXPERIMENTS WITH LEAD.
257
As hair is allied to albumen in composition, and likewise contains
free sulphur, leaden combs are frequently used to darken it, and a hair-
dye composed of litharge and cream of lime has been recommended
for changing red hair to a blackish hue.
Twelfth Series.
The tests for lead are well marked in the results they produce.
A solution of sulphuretted hydrogen precipitates lead from its solution
as a black sulphide, when free from excess of acid; if the latter pre-
ponderates, it must be neutralized by ammonia or carbonate of soda before
using the test.
A solution of sulphide of ammonium affords a deep brown-coloured
precipitate in solutions of lead free from an excess of acid.
Potash precipitates the hydrated white oxide of lead soluble in an
excess of potashi, and more decidedly when the latter solution is hot than
cold.
Hydrochloric acid or a solution of salt precipitates the chloride of lead
soluble in boiling water, and very insoluble in cold.
Iodide of potassium precipitates the iodide of lead, which, if dissolved
in boiling water, and allowed to cool, separates again in beautiful golden
spangles. The solution of lead must be neutral.
Sulphuric acid throws down a white precipitate of sulphate of lead,
which may be collected, washed, dried, and reduced by black flux to the
metallic state. Sulphate of lead is nearly insoluble in water, and very
slightly so in dilute sulphuric or nitric acid; it is soluble in the alkalies
and in tartrate of ammonia, so that the presence of certain salts of
ammonia may interfere with its precipitation.
Chromate of potash precipitates the beautiful yellow chromate of lead
soluble in nitric acid.
The formation of the crystalline deposit of lead called the lead tree in
a solution of lead by a piece of zinc is very characteristic of the metal.
Thirteenth Series.
Type-metal is composed of one part antimony and four parts lead, with
a little bismuth.
Common pewter is made by melting together eighty parts of tin and
twenty of lead.
Plumber's solder is made of equal parts of lead and tin. Three equiva-
lents of tin and one of lead make the most fusible alloy.
Tea-lead, or the metal used by the Chinese for the lining of the tea-
chests, consists of nine parts of lead with one of tin.
Shot-lead appears to owe its property of taking the spherical form when
melted and poured through a colander placed on an upper floor of a
lofty tower to the presence of a certain quantity of arsenic, amounting
toths to ths per cent. The addition of too much arsenic causes
the shots to be like a double convex figure, or to be pear-shaped when
too small a dose of arsenic is added to the melted lead. The sieve or
10
S

258
LEAD.
colander is prepared inside with the dross scraped off the surface of the
melted lead, seemingly to prevent the melted lead adhering to, or, as it
is termed, wetting the surface of the colander, so that the lead may flow
or drop directly through the orifices. An ingenious person at Newcastle
constructed a shot manufactory out of a deserted coal-shaft, and thus
escaped the cost of building a tower like that we see near Waterloo
Bridge.
Fig. 159. Ancient Crypt under Bow Church, showing the Arrangement
of the Leaden Coffins,

ORIA
ICT
G
BRIT
REG:F:D
186
Fig. 160. The new Bronze Penny Piece.
PENNY
CHAPTER VII.
COPPER.
오
​The symbol is supposed to represent the looking-glass of Venus.
An old author, describing this metal, says, "Es, or copper (which was
so called from the Isle of Cyprus, where it was first gotten in great
plenty), is a metallick body, participating of a fuscous or darkish red-
ness, being ignible and fusible, and is as the mean betwixt gold and
silver, and is generated of argent vive (quicksilver), impure, not fixt,
earthy, burning red, not clear, and of such a sulphur, it wants fixation,
purity, and weight." The author's name is Webster, who wrote a
History of Metals," and, not content with his own description, he also
quotes that of Casalpinus, "That copper doth in colour imitate gold, for
if its redness be a little diluted, it becomes aurichalcum (brass), most like
to gold; and that it imitates silver in its tractable substance and slowness
of fusion, for it requireth ignition before it be melted. But it differs
from both, because it doth not bear the trial of fires (as they do), but is
universally burnt; from whence it is noted to contain much of combustible
exhalation, far above the rest of the metals it yieldeth a sulphurous smell
and flame. Besides being modified, it doth most easily contract a rust,
which is called ærugo, of a green colour."
Although garnished with many pedantic words, the above description
affords a tolerable account of the most prominent qualities belonging to
copper, which was called "Venus" by the alchemist; uot, it appears, or
account of any remarkable metallic charm, as Webster states "that it
participates of a fuscous or darkish red," but in consequence of its easy
union with other metals, and the change which ensues in its nature and
appearance.
s 2
260
COPPER.
Werner conjectured that copper was the first metal worked by man,
and Jamieson observes that "this opinion may be considered as very
probable, especially when supported by the account which is given of
some of the native tribes of the north-western parts of America, who,
though little civilized, have applied to domestic purposes the native
copper with which their country abounds. It is also known that at a
very early period, domestic utensils and instruments of war were made
of a compound of this metal and tin; even during the Trojan war, as we
learn from Homer, the combatants had no other armour but what was
made of bronze, which is a mixture of copper, tin, and zinc. Macrobius,
who wrote in the fourth century, informs us that when the Etruscans in-
tended building a new city, they marked out its limits with a coulter of
brass, and that priests of the Sabines were in the habit of cutting their
hair with a knife of the same metal.* The Greek and Roman sculptors
executed fine works of art in porphyry, granite, and other hard minerals
by means of their copper instruments. The great hardness of the ancient
copper instruments induced historians to believe that the ancients pos-
sessed a particular secret for tempering copper, and converting it into
steel. There is no doubt the axes and other ancient tools were almost
as sharp as steel instruments, but it was by a mixture with tin, and not
by any tempering, that they acquired their extreme hardness. Axes and
other instruments of copper have been discovered in the tombs of the
ancient Peruvians, and also in those of the early inhabitants of Mexico.
These were so hard, that the sculptors of these countries executed large
works in the hardest greenstone and basaltic porphyry; their jewellers
cut and pierced the emerald and other precious stones by using at the
same time a metal tool and a siliceous powder. Humboldt brought with
him from Lima an ancient Peruvian chisel, in which M. Vauquelin found
ninety-four parts of copper and six of tin. This mixture was so well
forged, that by the closeness of the particles its specific gravity was
8.815, while, according to the experiments of M. Briche, chemists never
obtain this maximum of density but by a mixture of sixteen parts of
tin with 100 parts of copper. It appears that the Greeks and Romans
made use of both tin and iron at the same time in the hardening of
copper. A Gaulish axe found in France by M. Dupont de Nemours,
which cuts wood like a steel axe, without breaking or yielding, contained,
according to the analysis of Vauquelin, eighty-seven of copper, three of
iron, and nine of tin."+
Europe, Asia, North and South America, and Australia are all well
supplied with deposits of copper ore, and England specially has been
remarkable for centuries as containing in Cornwall numerous copper
mines. It occurs in this locality in veins that traverse granite and
clay-slate, along with tinstone, red copper ore, common quartz, rock-
crystal, &c.
The ores of copper are somewhat numerous, and although they are
Macrobius, Saturnalia, lib. v. cap. 19, p. 29. 512.
+ Humboldt's New Spain.
ORES OF COPPER.
261
not to be distinguished by any one particular external appearance, they
are easily recognised by the action of a solution of ammonia upon them.
A little of the mineral suspected to contain copper may be powdered,
heated on a bit of platinum foil, and then digested with ammonia. The
production of a very marked blue solution serves to indicate the presence
of the metal, which may be confirmed by the use of other tests described in
the experiments with copper. Besides the blue water or solution of sul-
phate of copper which flows from certain copper mines, Jamieson enume-
rates twenty-three species, with other subspecies of copper ores-viz. :-
1. Native copper
2. Copper glance
3. Variegated copper ore .
4. Copper Pyrites
5. White copper ore
6. Grey copper ore
7. Black copper ore
S. Black oxide of copper.
9. Red copper ore
10. Tile ore
11. Azure copper
12. Velvet copper ore
13. Malachite .
In crystals, filaments, and
branches.
Copper, sulphur, iron, and
silver.
Copper, sulphur, iron, and
oxygen.
Containing from 30 to 50 per
cent. of iron, 12 to 36 per
cent. sulphur, and about 30
per cent. copper.
Copper, sulphur, iron, and
arsenic.
Copper, sulphur, iron, arse-
nic, antimony, lead, and
silver.
Same constituents as No. 6, with
the accidental addition some-
times of zinc and mercury.
Oxygen, copper, and a little iron.
Oxygen, copper, and a little
iron.
Oxygen, copper, carbonic acid,
and water.
Intermediate between Nos. 11
and 13.
Copper, oxygen, carbonic acid,
and water.
14. Anhydrous carbonate of cop- ( Oxygen, copper, a little iron,
per
15. Copper green.
16. Ironshot copper green .
17. Emerald copper ore
carbonic acid, and silica.
Copper, oxygen, carbonic acid,
water, silica, and sulphate
of lime.
Copper, oxygen, water, and silica.
Copper, oxygen, carbonate of
lime, silica, or copper, oxy-
gen, silica, and water.
18. Muriate of copper, or ataca- Copper, oxygen, chlorine, and
mite
•
water.
262
COPPER.
19. Phosphate of copper
20. Copper mica .
21. Lenticular copper ore
22. Olive copper ore
23. Cupreous arseniate of iron
S Copper, oxygen, and phosphoric
acid.
Copper, oxygen, arsenic acid,
and water.
Copper, oxygen, iron, arse-
nic acid, water, and silica.
All these ores, which contain copper, are available for the purpose of
extracting the metal, but copper pyrites and grey copper ore in England,
and azure copper in France, are those usually found in the greatest
abundance, and melted or reduced to the metallic state.
The copper veins or lodes of Cornwall present the most interesting
geological arrangement of the mineral, and they chiefly occur in the
killas, or greenish clay-slate, and sometimes in the "elvans," or granite,
so that the Cornish miners work chiefly in these rocks, and especially
near the line of junction between them. It has been already stated that
the localities where coal occurs are usually termed "coal fields;" these
are worked by different proprietors, and are confined to proper bound-
aries, beyond which no coal-owner may trespass. With minerals, when
the lode traverses the land of several proprietors of ground, it is usual
to call the respective divisions setts, which are worked at a fixed rental
or a per-centage on the value of the ore raised, termed the lord's dues,
amounting to about 6 to 7 per cent. A course is a term used to signify
a barren vein; but the word lode means a vein rich in mineral. The
slope of the vein to the horizon is called the underlie, or hade slope, and
when the vein divides into many smaller ones, like a cat-o'-nine-tails,
they are called strings; and if the vein becomes still thinner, it is
characteristically termed a "thread."
There are many systems of copper veins in Cornwall-viz., the rake
vein, the pipe vein, the flat vein, and the interlaced vein, and all the
skill, patience, and experience of the miners are sometimes demanded to
recover the lode, which is thrust out of its natural position by intersections
of worthless courses. In the article on lead the derangement of the
course of a vein has been already depicted (Fig. 150); and to show
how closely the old miners observed the positions of the veins of ore,
the following cuts, taken from Agricola's ancient work, are introduced.
They serve as ground plans, and give the reader a very fair notion of the
complicated position assumed by veins in the earth, into which the
spectator is supposed to be looking in a perpendicular direction. When
the lode is thrust downwards, it is not called a downthrow," as
in coal mining, but a slide;" and if forced upwards, it is said to be
"heaved," which corresponds with the "upthrow" of the collier. The
cavity containing the lode is necessarily surrounded by other rocks,
which are called the walls, the top being the hanging wall, or sod, while
the bottom of the bed is the foot wall, or floor. These terms are well
Gall
VEINS OF COPPER ORE.
A
1
Fig. 161. A. 'ief vein. B. Intersecting or cross vein. c. The other part of в,
removed from is natural position (rapta). The further removal and alteration of
the original position and continuity of the vein is shown to the right at DA B.
(Agricola.)
illustrated by the next diagram from Ure's "Dictionary," which is a
section of the famous Boroondara and Bulleen gold mines near Victoria,
SCHIST-STRATA
ele se bEGREES T
VRTZ REER...
CAVATION
SCHIST STRATA:
ལ་གི་
Fig. 162. Illustration of the Hanging Wall or Sod, and the Floor or Foot Wall.
in Australia. Here a vein of quartz containing gold fills a cavity in the
schist strata, which dips at an angle of 60 degrees. The schist is,
therefore, the walls of the vein, and if excavated properly, the hanging
263


264
COPPER.
wall or sod A, should be supported by the timbers, E, E, E, upon the foot wall
B, whereas the quartz has been removed in the rudest manner, without
taking these precautions; it is, therefore, a most dangerous working,
and the hanging schistose wall at 60 degrees may fall at any time and
annihilate the miners.
In the next cut it will be noticed that Agricola was desirous of giving
a still better notion of the actual appearance and position of the mineral
veins in the earth, and we have, in his rude attempt at a perspective view
of the vein standing in a supposed section of the earth, an approach
towards those correct and elaborate models of Mr. Sopwith, which de-
lineate so clearly the actual mechanism of faults, dislocations, cross
courses, veins, and lodes.


ހ. ނ
282,
Fig. 163. A B. Two veins, both of which descend obliquely, so that one passes
into or intersects the other. c. The point where they meet. Two veins, again, of
which one, marked D, descends straight into the earth, and the other, marked F,
obliquely, which passes into or intersects the other at E. (Agricola.)
The veins of copper ore vary in thickness from a few inches to several
yards or fathoms; they may dip down to profound depths beyond the
limits of mining, and have been known to extend for miles within the
industrial grasp of the intelligent miner. A loose earthy substance,
containing oxide of iron, and of a somewhat crumbly nature, as if it was
in a state of decomposition, called gossan, or
ઃઃ gozzan, "is regarded
by the Cornish miners as the avant-courier of a vein of copper ore.
Gossan usually lies on the back of the vein, and as it frequently outcrops
or comes to the surface of the earth, the plough has often been the first
OLD MINING MACHINERY.
265

Fig. 164. Mouth of a Copper Mine, with simple mode of reversing motion of
the chain on the shaft by two overshot water-wheels. (Agricola.)
266
COPPER.
instrument which has disturbed it, and awakened the attention of the
shrewd miners to the presence of copper.
ઃઃ
The author, whilst paying a visit to Tavistock, took the opportunity
of visiting one of the richest copper mines in the county of Devonshire,
called the "Devon Great Consols," formerly known by the name of
"Huel Maria;' 'huel" being an old Cornish word signifying a hole.
Here the visitor has an opportunity of witnessing the operations of
copper mining involving the use of water-power on the grandest scale.
The immense size and power of the water-wheels, one of which drains
the mine, and the other forces water over the hill to supply the dressing-
floor of the mine, strike the visitor almost with awe, as he watches
their steady and magnificent rotations. Walking up to the main shaft
of the mine, the traveller has no difficulty in finding the way, as he has
only to follow the enormous iron rod which connects the water wheel
with the pumping gear. This iron rod, or rather a succession of jointed
rods, is 1740 feet long, or about the third of a mile, and it lifts at
every stroke a large quantity of water to the adit level. The weight
of this pumping apparatus amounts to 500 tons. These water-
wheels are placed in a most romantic and beautiful country, and are
situated on the banks of the river Tamar, near Tavistock. A steamer
will take the tourist from Devonport to Calstock, and the route thence
to the "Huel Maria" copper mine passes through a most interesting
country, where the water-wheels may be numbered almost by hundreds.
The tools used by miners have already been alluded to, but when the
rock is too hard to be penetrated by ordinary manual labour, gunpowder
is employed. Formerly a hole was drilled in the rock, then dried out
with tow, the charge of gunpowder being inserted, clay was stamped
in, and it was finally connected with the surface by a rush (from
which the pith had been removed) filled with gunpowder, the rush,
or train, being inserted into the hole left after the nail (a small
taper rod of copper, tamped and crammed round with clay, or any
soft species of rock) had been removed. A paper quick-match,
or "swift," adjusted to burn a certain time, is fixed on the top of
the rush filled with gunpowder, so as to give the men sufficient time
to get out of danger; but, as may be easily conceived, accidents fre-
quently arose from the careless adjustment of the "swift," which either
burnt too quickly, or, hanging fire, from dampness, the miners would
approach to ascertain the cause of the apparent failure, when the mine
probably exploded, and projecting the pieces of rock outwards with
the force of a cannon, killed and wounded many men. The dan-
ger of blasting is now greatly reduced by the use of the improved
tamping bar faced with bronze or hard copper, and the employment of
"Bickford's fuse," which consists of a pyrotechnic mixture enclosed
within a tube of hemp well protected from damp by a resinous coating.
This fuse is so impervious to moisture, that it can be connected with a
bladder containing gunpowder, and, being set on fire, the bladder may
be drawn under the water. The composition inside the Bickford's fuse
continues to burn until the fire reaches the powder, when the usual
BLASTING WITH GUNPOWDER.
267
explosion takes place. The ignition of iron or platinum wire by the
voltaic current has also been most successfully applied as a means of
firing the gunpowder; and the latter method has one great advantage,
because it enables the miner to ignite a number of mines at one and the
same moment instead of firing them in succession, and probably weak-
ening the effect of the second or third shot by the explosion of the
first having shaken or cracked the surrounding rock. It is also stated
that the saving of time is very great, and that as much blasting may be
performed by voltaic ignition in three months as would have required
twelve by the old method with the rush train. The trouble, however,
of attending to the voltaic battery, and the remarkable cheapness of
Bickford's fuse, have caused the latter to be preferred by the practical
man.
The introduction of gunpowder in the year 1615 completely revo-
lutionized the art of mining, as it had done previously with the art of
war; and soldiers bravely resisting the enemy, as at Inkermann, have
been compared to solid walls and hard rocks which even gunpowder can
move but slowly. The effect of gunpowder in blasting appears to be
greatly increased by leaving a space of air above it; and this result was
very apparent to the author in devising an experiment to show the mode
of firing infernal machines beneath ships, as practised by the Russians
before Cronstadt. When a certain number of grains of gunpowder were
fired in a small close bladder-case under a model of a ship, no effect was
produced, whilst the same number of grains of gunpowder enclosed
with a large quantity of air, and fired, blew the model ship from the
surface of the water with great force and power.
Fatigued by previous exertion, the author was not disposed to en-
counter the hard labour of ascending and descending the tedious ladders
of the main shaft of the copper mine. Indeed, the descent of mines in
Cornwall astonishes the stranger, who is surprised to notice the absence
of those mechanical appliances of the rope and corve worked by the
steam-engine, which render the descent and ascent of coal shafts in the
neighbourhood of Newcastle and Durham so easy. The waste of the
strength and time of the miner must be enormous. But there is
another reason why the old climbing method should be abandoned, viz.,
its frightful effect on the health of the miner, who, after the fatigue of
his work, conducted frequently in an atmosphere which produces the
most distressing pulmonary complaints, is obliged to pull himself and
mining tools upwards through a depth of twelve or even eighteen hun-
dred feet; or, as has been calculated, the miner must perform an amount
of work equal to lifting fifty tous one foot high in order to reach the
surface of the earth. It has been estimated that many miners have
thus to make an exertion every night equal to climbing to the summit of
Cader Idris, and this in a shaft frequently used for the purpose of an
air sewer to remove the foul air from the depths of the mine.
Stimulated by the offer of the high premium of 5001. from the Royal
Cornwall Polytechnic Society, the Tresavean and United Mines were
the first to adopt a "man machine," which consists of a long and con-
268
COPPER.
tinuous wooden beam, or iron rod, descending through the whole length
of the shaft. This long rod is connected with a working beam, which

F
C
B
B
B
D
E
Fig. 165. "The Man Lifter," showing the fixed stages, or shelves, ▲, A, A, and the
moving ones, B, B, B, attached to the rod, c, which is worked by the arm counter-
poised by E. The pull is given at F. The man lifter is adopted at the Tresavean
mine, which is 350 fathoms deep, and formerly occupied the miners one hour and
a quarter to ascend by ladders placed nearly perpendicular.
communicates to it a stroke or movement of twelve feet. The beam
is worked by steam- or water-power, and attached to the long rod, at the
intervals of the length of the stroke-viz., twelve feet-are placed
shelves sufficiently large to carry two men. The mere act of moving
the rod, with the shelves attached, up and down, would of course be
useless; but at the same intervals, and attached to the side of the shaft,
are other fixed shelves; consequently, the miner has only to step from
the latter to the moving ones to be lifted twelve feet each time, and to
be gradually and safely transported to the surface. Where this inven-
tion is used, it is stated that the health of the miner is greatly bene-
fited, and that heart disease, induced by the strain of climbing the
almost endless ladder, is no longer prevalent amongst them. The mor-
tality amongst the hardworking miners would be greatly decreased if
the use of these man machines were insisted on, with proper enclosed
DRESSING COPPER ORES.
269
lavatories for washing, so that the miners, after sustaining the close
heat of the deep mines, which usually stands at something like 80° Fah.,
should not be exposed to the cutting winds that assail him at the sur-
face of the mine during the cold months of the year. Thus, in Red-
ruth, which abounds in copper mines, it is stated that in every 100,000
of the population 220 males die of pulmonary disease more than females.
This is not so bad as the lead-mining districts, where the excess is 320
in every 100,000, and the death rate of the men is double that of the
women. In the tin mining districts of Penzance the superior waste of
male over female life in the mining population of all ages is 104.
From the mouth of the shaft the visitor proceeds to that part of the
works where the ore is "cleaned" or "dressed," and it may be observed
that the miners below take care to select the proper ore to send to the
surface, and use the rubbish to fill up holes or any vacant spaces in
the mines; if obliged to send up the " deads," it is kept separate from
the ore.
The large stones containing the copper ore are broken by
men and then arranged in three divisions-viz., "the deads or attle,"
the pure ore," and "the best ore," this latter is frequently broken
again into smaller pieces, or cobbed," by females, who, reclining on
shelves or floors placed a few feet above the ground, and under a rude
cover or roof, select the best portions of the ore and occasionally re-
lieve their labours with low, soft, and melodious choruses which sur-




Fig. 166. Ragging, Spalling, Riddling, and Cobbing the Copper Ore.
270
COPPER.
prise the stranger, who looks with pitying eyes on these poor women
doing such rough work and so exposed to all the changes of the
weather. It is unnecessary to add, that "6 consumption" here is
scarcely less fatal with these young women than with the underground
workmen.
The sorting and division of the broken ore is of course conducted
with great care and discretion, and it is now conveyed either to the
stampers or crushing mill, already described in the chapter on lead,
and then "riddled," or passed through a sieve having meshes of certain
dimensions. The first-class copper ore is passed through a coarse
riddle, the "poor ore" through one having finer meshes. To separate
the earthy from the mineral particles, a process called "jigging,"

Fig. 167. The Jigging Machine.
is used, by which the powdered and riddled mineral is placed in a
sieve formerly worked by hand, but now by steam-power. The sieve
receives a constant motion in a cistern of water, and the principle of
specific gravity determines the separation of the heavy from the light,
earthy, and worthless particles. If a number of marbles and leaden
bullets are placed in a sieve separately by hand, so that the two are
thoroughly mixed, they may be again separated into two layers, the
lead being at the bottom and the marbles at the top, by giving the
sieve a constant succession of half turns or rotations with an upward
jerk, and if this is done under water with smaller particles, like the
riddled" ore, the rich mineral sinks to the bottom of the sieve, whilst
the earthy matter is found at the top, the intermediate position being
filled by the ore, having more or less siliceous matter adhering to it.
The fine particles which pass through the meshes of the sieve sink
partly to the bottom of the cistern, and are partly carried off by the
water to other contrivances, where the greatest ingenuity is displayed in
arresting the passage of the fine grains of ore, so that little or none is
wasted, and the earthy matter only washed away. By crushers,
SALE OF COPPER ORES.
271
"jiggers," cylinders armed with spikes or paddles, riddles, and buddles,
the ore is collected and prepared for sale, and being arranged in heaps
or “piles,” bearing a ticket or label, having the weight of the heap in-
scribed thereon, samples are removed by intending purchasers for a
preliminary “assay." The sale, or ticketing, is conducted in silence; each
person proposing to buy deposits a piece of paper with his price and
name in a glass goblet, and the auctioneer, called the clerk of the
ticketings, afterwards removes and opens the papers, and finally ad-
judges the ore to the highest bidder.
Mr. Oxland, the learned consulting chemist of Plymouth, in the
valuable work entitled, "The Useful Metals and their Alloys," makes
the following remarks on the sale of copper ores, so far as it affects
the prosperity of the Cornish miner, which, taken in conjunction with the
statements made by a gentleman in the "Chemical News" of July 21st,
1860, appears to show that "monopoly" of any kind is opposed to
progress and improvement, and tends to unequal dealing on one side, the
poor or labour side, of course, being the loser. Mr. Oxland remarks,
That the system of submitting ores for sale by tender seems equi-
table, and calculated to give the miner the real value of his ores; but
the competition is limited to too small a number completely to ensure
this desideratum. The smelting of the ores is performed by about
twelve firms; but the control of the trade, the regulation of prices
and wages, and the prosperity of the miner generally, are in the
hands of three firms, who collectively purchase more than a half of the
total quantity of ores sold in Cornwall and Wales; while the pur-
chases of six of the remaining nine firms do not amount to more
than one of the larger ones. In consequence of this concentration of
the trade in the hands of three private firms, the competition system,
so far from affording the miner the value of his ores, is altogether
illusory. The baneful effects of a system which places such un-
limited power in their hands, is only too apparent in the paucity of in-
ventions emanating from the smelting interests."
•
In consequence of the comparative scarcity of coal in Cornwall
and Devon, the copper ores are not smelted in these counties, but are
taken to the coal fields of South Wales-viz., to Swansea and its imme-
diate neighbourhood. Here the effect of the "copper smoke," as it is
called, on plants, shrubs, and vegetable life in general, is very marked,
and yet it is asserted that the effect on human life is not so great as
might be expected. Leaving this question for the ultimate decision of
those stern truth-tellers, the laborious and careful collectors of sta-
tistics, it is certain that large quantities of sulphur are annually
wasted and carried off by the chimneys of the Swansea smelting works
in the invisible form of sulphurous and sulphuric acids The quantity of
sulphur thus wasted is calculated to be equal to 50,000 tons weight per
annum.
The per-centage of metallic copper in the ore when sold for smelting
varies considerably, and a most elaborate "fire torture" is required to
liberate the copper in a state of commercial purity. The furnaces em-
272
COPPER.
ployed are modifications of the "reverberatory furnace," and by the
proper application of heat, air, and fluxes the metal is at last procured,
after passing through at least eight operations, which are increased to
ten when every stage of the economical adjustment of the process is
taken into consideration.
No. 1. Calcination, or roasting by a reverberatory furnace to drive
off matters volatile by heat-viz., sulphur, arsenic, zinc, and
antimony.
No. 2. Melting by the stronger heat of a smaller reverberatory furnace
the roasted ore with a small quantity of other unroasted ore
containing a larger per-centage of copper, also some fluor
spar and slag, when the "matt," or coarse metal, containing
about thirty per cent. of copper, is run off into water or
granulated, and the slag, or scoriæ, is raked off into moulds
in sand, or regularly cast in iron moulds, and used for build-
ing purposes.
No. 3. Calcination, or roasting of the coarse or crude metal in a rever-
beratory furnace of the same kind as that used in the first
operation for the purpose of driving off the volatile sulphur;
the heat is urged to a point short of fusing the metal, and
when completed, the granules of copper are found to be
reduced in size, and are of a deep black colour, and they
should consist of oxide of copper and oxide of iron.
No. 4. Melting by a reverberatory furnace the coarse metal with sul-
phuret of copper and certain slags, and again running the
"matt" into water. The crude metal, called "white metal,"
now contains from seventy to seventy-five per cent. of copper,
and chiefly consists of sulphuret of copper with about four
or eight per cent. of sulphuret of iron.
No. 5. Melting for "blue metal." This operation is nearly identical
in principle to that of the previous one.
No. 6. Remelting of slags, by a reverberatory furnace, from the
fourth, seventh, and eighth process, for the purpose of pro-
curing a "matt" in which the copper contained in these
slags shall be brought together.
No. 7. Roasting, or calcination of the blue metal in a reverberatory
furnace, and its conversion into white metal similar to that
obtained from the fourth operation, and likewise for the
expulsion of the different ingredients which are prejudicial
to the quality of the copper.
No. 8. Calcining, or roasting in a reverberatory furnace, from regulus
to procure a very white metal which contains about eighty
per cent. of copper.
No. 9. Roasting and fusion of the regulus in a reverberatory furnace,
and preparation of crude copper.
No. 10. Preparation of fine copper by the refining, polling, and toughen-
ing of the product of No. 9; also conducted in a modified
reverberatory furnace.
WASTE OF SULPHUR
273
It is stated that there are at least 500 furnaces at work night and
day at Swansea, which consume nearly 500,000 tons of coal per annum;
and, out of a population of about 30,000 souls, employ about 4000, who
receive nearly 40007. sterling in wages every week. It is not surprising
that British copper should be the best in the world with such facilities
and experience, but it is a remarkable fact that the economy of the pro-
cess, so far as the saving of the sulphur is concerned, is not better
attended to; but trade secrets leak out, and the following remarks by a
scientific man, signing himself J. A., in the "Chemical News," explains
the mysterious abnegation of that wealth which may be derived from
the saving of the sulphur in the processes of copper smelting.
A misunderstanding arose between the British Government and that
of the kingdom of the Two Sicilies, some twenty years ago, respecting the
shipment of sulphur from the island of Sicily, as the latter government had
ceded to a French company a grant for the exclusive shipment of sulphur
from that island. I was at that time engaged in the neighbourhood of
Swansea, and noticed the amount of damage and nuisance caused by the
escape of sulphurous vapours from the copper works; it struck me that
this might be avoided, and that the sulphur might, at any rate, be made
available for the forming of sulphuric acid.
"An opportunity was afforded me for trying some experiments on a
pretty large scale, and I succeeded in obtaining sulphur from copper
ore. The mode by which I obtained this was, however, not applicable
to the existing plant and modus operandi of the established copper
works. I was engaged for a length of time in devising some modifica-
tion of my plan so as to adapt it to the existing order of things. I had
opportunities of making propositions to one or other of the coppe
smelters from time to time, which were always disregarded. At length
I thought of the plan of making a cheap preparation of iron to take up
and retain all the sulphur in the slag.
I devised an arrangement
of furnaces for this purpose, so that the process of copper smelting might
be conducted by one single continuous operation. I did not submit
this plan formally to the copper trade as a body; but having special in-
troduction to one of them on another subject, I incidentally introduced
my ideas on copper smelting as above. This gentleman entered into
my views very warmly, promised me all his individual assistance, and
that every facility should be afforded me at their works for carrying my
plan into operation. This occurred on my first interview. I had a par-
ticular engagement at that time which prevented me seeing this party
again for two or three weeks; at the end of which time I sought a
second interview, which I had great difficulty in obtaining. His manner
was now completely changed; he would do nothing to assist me, and
entered into a detail relating to the copper trade, some of which it would
not be right to mention here; but what he did say amounted to this,
that the copper trade was in a peculiar position, in the hands of half-a-
dozen very wealthy firms, having a most perfect understanding amongst
themselves; that if any plan came into use, this understanding would be
broken up, a stop being put to the nuisance from copper works, and so
T
274
COPPER.
great a saving of fuel effected that copper smelting might be carried on in
almost any locality; that the trade would thus become revolutionized.
"This conversation took place in 1848, the year in which revolutions
were so much in fashion.
C
"Finding that the copper trade' was so decidedly hostile to any
innovation, I abandoned this long-cherished project in despair, as I
thought it in vain to submit it to any parties ignorant of the mysteries
of copper smelting, since to any such, my scheme must have appeared
altogether visionary."
It may be supposed that this letter will stimulate a few more capitalists
to compete with the fortunate "half dozen," and that copper smelting
“will ultimately be carried on in almost any locality," to the great economy
of sulphur, and the protection of the lungs of her Majesty's lieges.
It is right to mention that, although the complicated methods of
smelting and refining copper are those which are generally pursued at
Swansea, there are certain patented improvements that have been
carried out to a certain extent, such as Blankart's, Rivet and Phillips's,
Napier's, Davies's, Birkmyre's, De Sussex's, Low's, Parkes's, Trueman
and Cameron's processes. It would, however, be foreign to the object
of this popular work to describe them in detail, and therefore the reader
is referred to Muspratt's splendid work on "Chemistry," or Phillips's
Metallurgy," or "The Useful Metals and their Alloys," for full informa-
on the subject.
re
The water which flows from certain copper mines sometimes contains
a considerable proportion of sulphate of copper, produced, no doubt, by
the spontaneous decomposition and oxidation of the sulphide of copper.
When the water contains a sufficient quantity to pay for the cost of
precipitating the copper, it is collected in ponds, and all the old clippings
of tin-plate, old battered iron pots and kettles, the refuse metal left after
stamping out steel pens, iron borings, in fact, iron in any shape as a
waste product, is cast into the pond; when the usual change of places
occurs, the iron is dissolved and the copper precipitated in a dark
powdery mass. It was by attention to this simple fact that a poor
Cornish miner realized a handsome fortune, and helped to lay the
foundation of a great and now ennobled family. He was accidentally
examining a part of the country to which he was a stranger, when his
attention was directed to a little spring flowing from the hill-side that
appeared to have a bluish appearance, being rejected by cattle and
man, because it was said to be of a poisonous nature. Stooping down
and dipping his knife into the water, he soon obtained that evidence of
the presence of copper which is unmistakeable, and rightly conjecturing
that the spring must flow from a mass of copper ore, he strongly urged
the proprietor of the land to commence searching for this mineral. It is
unnecessary to add that the search was entirely successful, and the vast
heaps of "deads" or "attle" attest the enormous wealth obtained from
this locality in the shape of copper ore.
This process of obtaining the copper from its natural solution in springs
flowing from copper ores is called “cementation," and is conducted
with profit at the "Paris Mounts in Mine," in the island of Anglesea,
THE PROCESS OF CEMENTATION.
275
now connected with the mainland by the famous Menai and Britannia
tubular bridges.
It is stated that copper mines have been worked in Anglesea from a
very remote period, and that the Romans were acquainted with the
Hamlet Mine, near Holyhead. The water is very limited in quantity at
this mine; it contains a considerable quantity of copper in solution, and
is precipitated by old iron in the manner already described. It is highly
creditable to those who work and smelt the copper ores at Anglesea, that
there they do save a portion of the sulphur.
In the Museum of "Practical Geology" there is a gilt copper cup
obtained from the copper mine of Herrn-ground, in Hungary, and made
from copper obtained by precipitation. The German inscription on the
cup is, "God shows in me his great power, who out of iron makes
copper;" and the date of this cup is about 1650.
One of the most curious instances of the precipitation of copper from
its solution by metallic iron has been mentioned by Messrs. Varley and
Lyell, in their report on the "Atlantic cable." This costly metallic
rope appears to have been completely decomposed by the action of the
sea-water, and was in such a rotten state, that even pieces of it could
hardly be hauled on board without breaking. The report states: "The
iron wires in many places often appeared sound, but on minute inspec-
tion, were found eaten away and rotten; the serving was also decayed.
In some places the iron wires were coated with metallic copper and
much eaten, they having most probably rested upou copper ore, for there
are veins of it in Trinity Bay. The gutta-percha and copper wire are,
however, in as good condition as when laid down. Those portions of the
recovered cable that were wrapped with tarred yarn were sound, the tar
and the hemp having preserved the iron wires bright and free from rust.
This will be further reported on when the pieces of recovered cable have
been more closely examined."
In the museum are also interesting specimens of sand from Perran
Zabuloe, on the north coast of Cornwall, where the drainage-water,
charged with sulphate of copper from a deserted adit, flows on to the
sand of the beach, which contains a large quantity of carbonate of lime,
in the shape of countless shells, and is there converted into a carbonate
of copper, whilst the carbonate of lime is converted into sulphate of
lime or artificial gypsum. This latter appears to act as a powerful
cement, and Mr. Henwood states, that "so hard had this floor of copper,
varying from one to eight inches thick, become cemented together, that
it was found necessary to use gunpowder to remove it.
carbonate of copper is worth six pounds per ton, and this natural copper
ore manufactory is still in operation, and must afford a good profit to the
lord of the manor on which it is situated.”
•
The
Mr. Henwood remarks, the hint ought not to be forgotten, as there
are no doubt springs or streams of water flowing from copper mines
which might be advantageously passed through great beds of roughly-
broken limestone or chalk, mixed with some siliceous particles to assist
filtration.
T2
276
COPPER.
Sir R. Murchison considers that the formation of malachite (of which
Russia furnished such magnificent specimens at the Great Exhibition of
1851) was probably caused by a somewhat similar natural process; and,
speaking of an enormous mass of this mineral, calculated to contain half
a million of pounds weight, and discovered at "Nijny Tagilsk," at a
depth of 280 feet, he says:-
The geological interest attached to this mass lies in the indication
it affords that the substance called malachite has been formed by a
cupriferous solution, which has successively deposited its residue in a
stalagmitic form. Mutatis mutandis, this mass has only to be viewed
as formed of calcareous spar (carbonate of lime), and it presents every
one of the features so well known to those who have examined stalactite
grottoes with their stalagmitic floors in the clefts and caverns of lime-
stones, or still more those large masses of tufa (or soft calcareous stone
formed by depositions from water) which have proceeded from calcareous
wells. Whenever a portion of the malachite has been broken off, the
interior is seen to consist of a number of fine laminæ (a fasciculus
of radio-concentric globules), which invariably arrange themselves
equally around the centre on which they have been formed, and are
adapted to every sinuosity of the pre-existing layer, here presenting a
dark line, there a bright and light one, just as the solution of the
moment, the day, or the hour happened to be more or less impregnated
with colouring matter. On the whole, we are disposed to view it
as having resulted from copper solutions emanating from all the porous,
loose, surrounding mass, and which, trickling through it to the lowest
cavity upon the subjacent rock, have in a series of ages produced this
wonderful subterranean incrustation."
•
A century ago several tin mines were abandoned when the miners
came to the yellows, or yellow copper ore, because they said the yellows
cut out the tin; but now the times are altered, and copper ore in any
shape is gladly welcomed by the miner. At the Polytechnic, Mr. Ten-
nant exhibited a great mass of native metallic copper from Lake Supe-
rior, in America, which is so tough that it cannot be blasted, and is
usually cut out with sharp chisels; the mass exhibited was worth at
least 3007.
The metal copper, when obtained in the pure state, has a remarkable
red colour, and, as may be easily imagined, its specific gravity varies with
its mechanical state, being from 8.6 to 8.95, which latter is the specific
gravity of sheet copper or flattened copper wire. It melts at a tempe-
rature somewhere between that required for the fusion of gold and sil-
ver, and placed by Daniel at 1994° Fah. Like melted silver, it absorbs
oxygen, when exposed in the liquid state to a current of air, which it
again resigns with spirting, as it cools. Copper is very ductile, and the
next in tenacity to iron; it conducts heat about two and a half times
quicker than the latter. Copper takes an excellent polish, to the
great delight of those who possess the metal in the shape of copper
culinary implements, and this property has been depicted over and over
again in the admirable works of Teniers and other great Dutch painters.
Copper precipitated by a voltaic current always preserves a crystalline
THE NEW BRONZE PENNY.
277
form, so that such deposits must be regarded as made up of a vast
number of crystals interlaced and united with each other, but still pos-
sessing pores or meshes which, though infinitely minute, interfere with
the use of iron or other metallic vessels (lined with electro-precipitated
copper) for chemical purposes. When copper is very slowly deposited
from its solution by a long-continued but feeble current of electricity,
it crystallizes in octohedra. If a large quantity of molten and liquid
copper is allowed to cool slowly, it crystallizes in the rhomboidal form.
With the intense heat of the oxy-hydrogen jet, copper boils like water,
and throws out a vapour which condenses on any cold substance, and if
examined by a magnifying glass, the deposit is found to consist of minute
particles having a core of metallic copper coated with the oxide of the
metal. Copper possesses great malleability, and may be beaten out into
very thin leaves; when alloyed with zinc in the proportion of two of the
latter to eleven parts copper, it forms the metal leaf called "Dutch
metal," so extensively used in theatrical decorations, the ornamentation
of toys, and certain kinds of gingerbread. The smell of copper is very
peculiar, and, like cinnamon, the taste of this metal very much resembles
the odour. Copper fuses readily with most of the metals, and affords several
compounds or alloys which are of great use in the common arts of life.
The alloy of tin and copper called bronze has been made from the
most ancient periods, and at least 600 years before the Christian era.
It is stated that Athens and Rhodes each contained three thousand
bronze statues. The latter place was celebrated for its colossal statue
in bronze which reached to the height of the watch towers. The pre-
paration of a perfectly homogeneous bronze appears to be one of some
difficulty, and the proportions of tin and copper vary according to the
use to which the bronze casting is to be applied. Thus for coinage it
may contain from four to seventeen per cent. of tin. Occasionally, zinc
is added in about the same proportion as the tin, so that the two to-
gether shall be from four to seventeen per cent. The bronze at the
Royal Mint is cast into ingots, and, with many precautions, laminated
between rollers; the blank pieces are then stamped out, weighed, ad-
justed, and impressed with the dies.
The coin of which Fig. 160, at the head of this chapter, is a sketch,
represents the penny of the new bronze coinage which is to displace the
old copper money, now become so imperfect as often to lead to a doubt
of its legitimacy. The bronze money will consist of 95 parts of copper,
4 parts of tin, and 1 part of zinc in 100 parts of the mixed metals.
The coins will be far thinner and, consequently, lighter than any of the
old coins, as shown below
Weighs in
grains.
Coins in
one pound
avoirdupois.
Measures in inches.
Diameter.
Thickness.
1.20
0·05550
48
1.00
0 05100
SO
0.80
0.03846
160
...
>>
The penny
halfpenny.
farthing
145.833
87·500
43.750
so that each coin is about half the weight of its representative in the old
278
COPPER
coinage of copper. The design on the coin possesses the important advan-
tage of being a correct likeness of her Majesty at the present time (1860);
otherwise it is without improvement, for there are to be found only the
old emblems not even dressed in new ideas; but there is one alteration, of
a strictly classical character, which deserves a passing word. If the
inscription be read, it will be found to exhibit the word (usually spelt)
'Brit." with a double "tt;" thus "Britt.," and for the following rea-
sons. On the old Roman coins "Britt." occurs, and is believed by
some numismatists to indicate that the coin was struck out of Rome, and
arose from ignorance on the part of the coiners; whereas all coins
struck in Rome at the same date exhibit the word spelt "Brit.;" and
this latter was at the time the correct mode of terminating the word.
At the present date it is necessary that the coin should indicate the
Queen's supremacy over all the British possessions, and, in conse-
quence, the abbreviation of the word "Britanniarum" must be treated
in the same manner as other words in the classics are treated, and
rendered (in its abbreviated form) plural by repeating the last letter;
so that if the abbreviation be made by writing "Britan.," it must be
written "Britann.," to indicate, as the word "Britt." does on our new
coins, the whole cluster of the British Islands now denominated Great
Britain.*
To convey an idea of the work of executing a new bronze coinage, it
is only necessary to state that at this time there are estimated to be in
circulation no less than 722,200 twopenny pieces (principally hoarded),
118,024,104 penny pieces,
266,855,297 halfpenny pieces,
102,966,564 farthing pieces,
16,438,176 half-farthing pieces (almost exclusively colonial),
504,284,141 copper coins,
besides many tons weight of tokens and false pieces.
In making any large castings the greatest uniformity in composition and
purity must be attended to, and the account of failures in former years
ought to enable contractors of the present day to avoid similar mistakes;
thus, at the erection of the celebrated column in the Place Vendôme, the
founder was completely ruined in consequence of his ignorance of the com-
position and properties of bronze. "The Chemist" of 1825 thus relates
the story: "This column was erected by order of Buonaparte in com-
memoration of the victories of the French armies, and it was cast out of
cannon taken from the Austrians and Russians in 1805. The whole weight
of the different pieces of bronze composing it was 900,000 kilogrammes,
or very nearly two million pounds. The contract for the performance of the
*To secure a perfect uniformity in the composition of the bronze, it is assayed by the
resident Mint assayers before the alloy is coined, and a sample of each ton of coined
bronze money is also assayed by Dr. Hofmann and Dr. Miller before it is allowed to go
into circulation. Each coin is allowed to vary to the limit of th part of its own weight
The author begs to
above and below the standard weight given in the Table p. 277.
express his acknowledgments to Mr. George F. Ansell, one of the eminent chemists at-
tached to the Royal Mint, for his courtesy in taking him through this most interesting
public establishment, and also for the valuable facts given as above.
CASTING BRONZE.
27€
work was made with an iron founder, who undertook the whole, carving
and all, for one franc a kilogramme. M. Darcet, the celebrated chemist,
tendered some good advice on the occasion, which was rejected, and the
contractor had a foundry built at a considerable expense. He employed
a furnace for melting iron; and being ignorant of the fusion of bronze,
he failed in his first attempts to cast the large pieces for the base of the
column. At each operation he altered the proportion of the alloy by
oxidizing the tin, the lead, and the zinc, the oxides passing into scoriæ,
or being partly carried off by the heated air.
He did not perceive this, and delivered the different pieces of differ-
ent qualities, but all of them contained a greater proportion of copper
than the bronze of the guns. When the column was about two-thirds
finished, he found his supply of metal exhausted; and so sure had he
been of having enough, that he had previously sold part of the ten per
cent. allowed him for waste, under the idea that it would be more than
sufficient. Being obliged to complete the work with the quantity of
metal delivered to him, he was placed in a disagreeable situation. Under
these circumstances, he endeavoured to cast the white metal obtained by
reducing the scoriæ, and a quantity of old brass he purchased at a low
price. The castings he obtained by mixing these materials were full of
bladders and spotted with lead; they were at first of a dirty-grey colour,
and afterwards became black. Such defective work could not pass;
the labours of the contractor were put a stop to, his foundry was sealed
up, and the man ruined." By dint of reclamations or appeals he procured
the appointment of a commission to examine his accounts. The com-
missioners wished to know the proportions of the different metals in the
guns delivered to him; but this point had not been ascertained, and,
therefore, the most important element for coming to a correct conclusion
could not be obtained. The weight of each piece of casting delivered
by him was known; and by taking morsels from them all, and smelting
them into one piece, an ingot was obtained representing the mean com-
position of the whole column.
After ascertaining this and knowing the general proportion of the
alloys of which cannon are constructed, the commissioners agreed in
opinion that the mean alloy of the column was equal to that delivered to
the contractor. By analyzing the different pieces it was found that the
large pieces of the pedestal contained only six per cent of alloy, while
the small pieces of the shaft and column contained twenty-one. It was,
therefore, evident that the contractor, not understanding the nature of
bronze, had refined his alloy in the first instance by repeated meltings;
and having thus diminished very much the total weight, was obliged to
have recourse to the means already described. At the commencement
of his operations, he had delivered the pieces with too much copper,
and at the end with too little. The pieces were, after all, so badly
executed, that 140,000 pounds of bronze were cut away by a sculptor,
who was, moreover, paid 300,000 francs for his labour.
Speaking of the decoration of columns with bronze, there is the
Nelson column, with its bronze Corinthian capital, and the four bronze
reliefs representing the battle of St. Vincent, the battle of the Nile, the
280
COPPER.
bombardment of Copenhagen, and the death of the immortal Nelson at
Trafalgar. There are also many bronze statues in London. Bell metal,
of which "Big Ben " has been a most unfortunate example, is composed
usually of seven-seven parts copper, twenty-one parts tin, and two parts
antimony. English cymbals form very expensive additions to a set of
instruments for a band, in consequence, it is said, of the large addition
of silver, in order to give the peculiar clang of these instruments. The
composition of Chinese gongs, cymbals, and tom-toms is very nearly the
same as that of ordinary bell metal. It is a curious fact, that whilst
steel is hardened by being cooled suddenly in water, copper, gold,
silver, and bronze all lose their hardness and acquire a tough and mal-
leable condition by being heated to a cherry red, and then plunged into
cold water. M. Darcet was the first to show that brittle bronze vessels
could be made hard and tough by heating to a cherry-red heat, and
cooling them suddenly in water; and it was by attention to this operation
that the ancients imparted such an edge and toughness to their bronze
swords and spear heads.
Speculum metal, used by opticians in the manufacture of the con-
cave mirrors of reflecting telescopes, requires great care in the casting;
it is usually composed of about sixty-seven parts copper and thirty-three
of tin, with a little arsenic. The author once assisted the late Mr.
Cuthbert in casting some of his speculums for his celebrated telescopes.
The metal was cast in a crucible by the heat of a furnace, such as that
described at p. 251, and when liquefied, was poured into iron moulds,
which were then covered up with sand and ashes, in order that the cast
metal might cool slowly. The most useful alloy of copper is, perhaps,
that which is included under the generic term brass, and consists of
copper, zinc, lead, and tin, in different proportions according to the use
to which it is to be applied. Various arbitrary names have been given
to this alloy, and it has been termed mosaic gold, Prince Rupert's
metal, pinchbeck, Mannheim gold, Bath metal, tombac, Dutch gold, &c.
Brass may contain from 60 to 92 per cent. of copper, from 5 to 35 per
cent. of zinc, from one-half to 3 per cent. of lead, and from a quarter to
3 per cent. of tin.
A very important alloy of copper used for sheathing vessels, termed
Muntz's metal, and remarkably soft and malleable, is composed of 16
parts copper, and 10% zinc; this alloy has a golden appearance, and
contains less zinc than mosaic gold, which, with the same proportion of
copper, is alloyed with about 17 parts of zinc.
The Chinese pakfong, tutenag, German silver, and electrum owe
their whiteness to the presence of the metal nickel, and, like brass, the
proportions of their ingredients-viz., copper, nickel, zinc, with occa-
sionally a little lead or iron-are variable. Thus the pakfong contains
about 1 per cent. of nickel, whilst the ordinary "German silver"
contains froin 20 to 25 per cent. Spoons made of this alloy consist
usually of copper 50, nickel 25, zinc 25 parts.
Unalloyed copper is used for innumerable purposes in the arts and
manufactures; plates, &c. for engravers, domestic utensils, kettles,
scuttles, urns, coinage, sugar-refining apparatus, brewers' coppers, dis-

COPPER ROOFS.
281
tillers' stills, dyers' vats, marine powder-magazines, sheathing of ships,
soda-water machinery, and culinary and confectionary vessels; the
latter are usually coated inside or alloyed with tin, in order to prevent
the poisonous effects of copper. The tinning of copper vessels used in
cooking should be as scrupulously attended to as it is in India, where all
the cooking vessels are made of this metal or brass, and are regularly
coated with tin at stated intervals or sooner if necessary. Pins are
tinned by the wet process, and are coated with the metal by boiling
them with water, bitartrate of potash, and finely-divided tin.
Russia (as it used to be in England in the medieval period), the
roofs, domes, and cupolas are frequently covered with copper and some-
times gilt, of which we give an example in the next cut, representing
the bell towers and famous bell of Ivan Veliki at Moscow.
In
Fig. 168. The Bell Towers with gilt copper cupolas, and famous Bell
of Ivan Veliki at Moscow.
i
282
COPPER.
EXPERIMENTS WITH COPPER.
First Series.
The assay of copper ores demands a considerable acquaintance with
the nature of fluxes, and the manipulations connected with furnaces,
the fuel, the crucibles, the regulation of the heat, &c. The ores are
usually divided into three classes-
No. 1 includes ores such as the red oxide of copper, the black oxide
of copper, the green carbonate of copper, the blue carbonate of copper,
&c. &c., which, with the exception of a little iron, contain no other
metal but copper, and are quite free from sulphur and arsenic. Such
ores, after being powdered, may be mixed with at least three times their
weight of black flux, prepared by throwing into a red-hot crucible a
mixture of one part nitre and two of crude tartar. The furnace, such
as that described at p. 251, must be lighted some time beforehand,
and should be, with the crucible, quite hot. The mixture of ore and
black ore is then thrown in, so that about one-third of the red-hot cru-
cible is filled, leaving the remaining space for the materials to swell
and puff up, and it is usual to spread a thin layer of black flux on the
top of the mixed ore and flux. The cover of the furnace is left off until
the pasty mass is in a state of tranquil fusion, when the furnace is closed
and the heat urged to the utmost for about twenty minutes; the glowing
crucible is then removed, gently tapped on a dry and warm brick, where
it is allowed to stand till cold, or the contents are at once poured into
a conical iron mould. The impure metallic button of copper called
the prill is found at the bottom of the crucible and mould, and may be
examined, if necessary, by the humid process of analysis described at
p. 284. In order to collect every particle of copper, it is usual, when
assaying very pure copper ores of this class, to fuse them first in con-
junction with sulphur, and to assay according to the method belonging
to the next division.
No. 2, ores containing only copper, iron, and sulphur, such as copper
pyrites, copper glance, vitreous copper, red ruthite, &c. The pulverized
ore is mixed with its own weight of borax (previously dried and pow-
dered), and melted in a crucible at a moderate heat. The contents are
then poured into a proper mould, and when cold the sulphide of copper
called the "matt," is found at the bottom, and may be easily separated by
a hammer from the slag which contains the earthy matters called the
gangue.
The "matt," regulus, or button, is then powdered (being very brittle,
in consequence of its combination with sulphur), and thrown into a
crucible arranged in a slanting direction, and placed in a furnace where
the heat is kept as low as possible, and the mouth of the crucible well
supplied with air; these conditions are fulfilled by using a properly-
constructed roasting furnace like that depicted in the next cut, al-
though, where expense is an object, an ordinary open fireplace would,
(with proper care) answer the same purpose.
ASSAY OF COPPER ORES.
283
As the roasting proceeds the heat may be gradually raised, and
when the odour (like that of a burning sulphur match) can no longer
be perceived, the crucible may be shifted to a wind furnace, and brought
up to a full white heat in order to decompose the sulphates and drive
off the last atom of sulphur. Sometimes a little carbonate of am-
monia is stirred in before exposure to the white heat. The roasted
ore is finally mixed with three and a half times its weight of black
flux, and being covered with a stratum of powdered fused borax, called
glass of borax, it is strongly heated in a wind furnace for about half
an hour, taken out, cooled, and broken, when the button of copper
is found at the bottom as usual, and may be cleaned by hammering on
the anvil and gently rubbing it with the leather gloves usually worn by

E
A
D
B
A
C
Fig. 169. Roasting Furnace. ▲ ▲. A square cavity in brickwork, with small
grate at B, to which air passes from the opening c, closed at pleasure by a
door and register. D. The crucible containing the powdered "matt," which
is kept at a very low heat, and occasionally stirred with a steel rod; the
sulphur is oxidized and carried up the chimney at E, and the whole is covered
with a hood of sheet iron, F G.
those who perform many crucible operations. The wind furnace will
be described in another part of this work.
Third class copper ores, such as grey copper ore, tennantite, white
copper ore, &c., containing the sulphides of other metals and arsenic,
are first powdered and fused with borax to obtain the "matt," which is
then powdered, and very slowly and carefully roasted, to prevent the
284
COPPER.
fusion and agglomeration of the particles. When arsenic is present,
it is usual to mix in a little powdered charcoal after the first roasting,
and then to raise the crucible to a bright red heat. The roasted "matt
is then fused, as already described, with black flux or glass of borax,
and the button of copper, containing various other metals, is placed on a
cupel of bone earth in the muffle with a certain proportion of pure lead,
and cupelled in the manner described at p. 223. The lead removes the
other metals, and, being oxidized with them, sinks into the cupel, whilst
the copper remains behind as a little bead or button, which ceases to
rotate, and suddenly brightens up when the process is complete. The
cupel is removed, cooled, and the bead of copper picked off, gently ham-
mered, rubbed, and weighed. In these metallurgical operations par la
voie sèche, practice truly and only makes perfect, and each assay should
be repeated at least twice.
Second Series.
Copper is analysed in the humid way, par la voie humide, by dissolv-
ing, say twenty grains (cut off the sheet, wire, or ingot), with nitric
acid in a flask provided with a long neck, or one partly closed by a
funnel. If any antimony or tin are contained in the sample, they will
be left behind as insoluble teroxide of antimony and binoxide of tin,
and they may be further precipitated by evaporating away the greater
part of the excess of acid and diluting with water. By filtering, these
oxides are separated, and may be collected, weighed, and examined by
the tests described under the respective chapters on these two metals;
although it may be mentioned here that tartaric acid will dissolve out
the oxide of antimony, and leave the oxide of tin behind.
The solution contains the copper with any silver, lead, zinc, iron, or
arsenic with which it may have been contaminated. The silver is pre-
cipitated by the addition of a few drops of hydrochloric acid, and, being
allowed to settle, the solution, now containing the copper, lead, zinc,
iron, and arsenic, is washed away carefully, and the chloride of silver
collected, dried, and weighed. The solution mixed with the washings
from the chloride of silver is now precipitated with sulphuretted hydro-
gen, and being kept slightly acid, is gently warmed, filtered, and the
precipitated sulphides of copper, lead, and arsenic collected and washed.
The iron and the zinc are the only metals now left in the solution, which
is evaporated to a small bulk with some nitric acid and treated with
excess of ammonia, which throws down the sesquioxide of iron; after
filtration to separate the latter, sulphide of ammonium is added to pre-
cipitate the zinc. The precipitated sesquioxide of iron is washed,
dried, and ignited, and the sulphide of zinc may be converted into the
more permanent oxide of zinc before it is weighed and estimated.
The sulphides of copper, lead, and arsenic left upon the filter must be
kept as much as possible from contact with the air during the washing,
and this may be managed by putting the glass and funnel under a gas
jar kept full of coal gas by holding an india-rubber pipe connected
EXPERIMENTS WITH COPPER.
285
with the gas fittings under the jar, and occasionally allowing the gas to
escape (Fig. 170) The nose of the analyst will inform him when it is escap-
ing from the edge of the jar. If the mixed sulphides, and especially the
sulphide of copper, is not defended from the oxidizing action of the air,
it is rapidly converted into sulphate, and washed away and lost during
the edulcoration of the mixed sulphides. A little hole is now made in
the filter, on which the sulphides remain, and they are washed off into
a flask by a solution of sulphide of potassium, for the purpose of dis-
solving out any arsenic that may be present. The solution may be
decanted off, and the sulphides washed by decantation. They are then
treated with weak nitric acid, and the solution is filtered and evaporated
to dryness with sulphuric

acid. This latter separates
the lead as the insoluble sul-
phate of lead, which is col-
fected, dried, weighed, and
estimated in the usual man-
ner, after, of course, treating
the dry residue with distilled
water. Copper only now re-
mains in the washings in so-
lution, and this is precipi-
tated by the addition of caus-
tic potash, which throws
down the hydrated oxide of
copper of a blue colour,
changing to a dense black
powder when the solution
containing the precipitate.
hydrated oxide of copper is
boiled. The black powder is
collected, washed, dried, and
scraped off the filter on to a
piece of glazed paper, the
filter is burnt away in a
porcelain crucible, and then
the black powder is placed
in and also ignited, and finally
weighed. Every 40 parts of
the black oxide of copper are
equivalent to 32 of copper.
The oxide of copper must
be weighed whilst hot, as it
absorbs moisture with great
rapidity.
B
D
C
Fig. 170. A. Funnel and filter containing the sul-
phide of copper, &c. B. Gas jar fitted with a cork
and glass tube in neck; the tube is bent round at c,
by which the water is poured in to wash the sul-
so that the coal gas may not escape. D. The funnel
phide of copper, and by turning the beaker round
that supplies the funnel, every part of the filter may
be washed. e. Gas-pipe connected with the coal-gas
fittings. The arrows denote the entry of the gas.
286
COPPER.
Third Series.
The equivalent or combining proportion of copper is 317 and it
unites with oxygen in various proportions, as follows:-
Suboxide of copper
Protoxide, or black oxide
Binoxide
Cupric acid
•
Cu.,O
CuO
CuO₂
The suboxide is made by heating a mixture of five parts of the black
oxide of copper with four parts of copper filings, in a close crucible, to
a full red heat; or by the wet process, by first boiling some syrup with
a little dilute sulphuric acid to convert the cane into grape sugar, and
then adding a solution of sulphate of copper with excess of caustic
potash to redissolve the precipitated oxide and form a violet-blue solu-
tion. On boiling this solution of copper for some time, the suboxide
gradually deposits and presents a crystalline form with a fine red colour.
This combination is found in nature, and is called by mineralogists red
copper ore.
Black oxide of copper is obtained by dissolving pure cop-
per in nitric acid, evaporating to dryness, and igniting the residue in an
earthen crucible until no more red nitrous fumes are visible. The pro-
cess occupies some time, and the oxide should be stirred now and then
with a copper rod. Binoxide of copper and cupric acid are combina-
tions which are only interesting to the chemist. The suboxide and
the protoxide of copper are both employed in colouring glass; the
former imparts a red colour, and the latter a blue or green colour. The
protoxide, or black oxide, forms with sulphuric acid that most valuable
salt called "blue vitriol," or sulphate of copper, CuO,SO,HO+4 Aq.,
which is employed so extensively in electrotyping and other useful arts,
likewise in medicine, and also in agriculture for the purpose of steeping
grain, before it is sown, to prevent smut. Sulphate of copper is sold
at such a very cheap rate, that it is never worth while to make it on the
small scale. Nitrate of copper is obtained by dissolving the black
oxide, or metallic copper, in nitric acid, and evaporating the solution
till a pellicle forms. The crystals are represented by the following
formula: CuO,NO, with 4 or 6 Aq., according to the temperature at
which it crystallizes.
The hydrated oxide of copper or oxide of copper united with a defi-
nite proportion of water, CuO,2HO, is obtained from a solution of
nitrate of copper by the addition of small quantities of caustic lime
until the green precipitate is no longer thrown down and the solution
becomes colourless. The precipitate is then filtered and washed, and,
when nearly dry, from eight to eleven per cent. of powdered caustic
lime is well incorporated with it, when the green colour changes to blue,
forming the well-known pigment termed blue verditer.
Sulphate of copper unites with ammonia, and produces magnificent
blue crystals, CuO,SO,,2NH,HO. The large show-bottles placed in
the windows of the chemists and druggists have generally one of their
number filled with a dilute solution of copper to which a slight excess
of ammonia has been added.
THE ELECTROTYPE.
Fourth Series.
287
Pure copper is obtained by decomposing a solution of pure sulphate
of copper by the voltaic current, as in the ordinary process of electro-
typing. The manipulations of this art have been so elaborately explained
by Napier and Walker, and also in the "Boy's Playbook of Science," that
it is almost unnecessary to mention them here; but as young persons do
not generally possess many books, and are sometimes restricted by their
finances to one, we give an easy method of conducting the process.
In the centre of a stoneware pan, or square wooden box well dove-
tailed and made water-tight, without nails, and nearly filled with a

H
C
G
LU
B
A
B
A
D
F
Fig. 171. ▲ ▲. Basin containing the solution of sulphate of copper. B B.
B B. The
porous cell, containing dilute sulphuric acid. c. Amalgamated zinc rod and
binding screw attached to wire and medal D. F. Porous cell, made with a lamp-
glass closed at small end by bladder and wire support & G, to prevent the mem-
brane touching the bottom of the pan containing the solution of sulphate of
copper. H. Brown paper porous cell, prepared by rolling paper of the required
length at least three times round a ruler, and closing the sides and bottom with
sealing-wax after the bottom is folded in.
strong solution of sulphate of copper, place a porous cell containing a
rod of amalgamated zinc surrounded with a mixture of one part strong
sulphuric acid and twenty parts of water. Round the top of the zinc
rod is wound one end of a length of thin copper wire, and the other is
attached to the seal or medal, previously well blackleaded and polished.
If a medal is used, the back should be imbedded in gutta-percha or
covered with wax, and the wire twisted round the rim, as the deposit of
copper is not required at the back, and might, indeed, spoil the medal
by preventing its subsequent removal from the electrotype cast. Very
little blacklead should be used with a medal, as it stops up the fine
lines; and sometimes a little sweet oil, or solution of wax in turpen-
tine is rubbed over it so as to prevent the deposited copper sticking to
and spoiling the medal. If an impression in sealing- or candle-wax is
used, this must be well blackleaded and polished on one face,
and twisted round with the thin wire, which is placed in good
288
COPPER.
conducting communication with the blackleaded surface. The medal
or cast is then placed into the solution of copper, and the whole left for
twelve hours, when the copper is precipitated over the surface of the
medal or cast, of which it takes an accurate copy in intaglio. From
the intaglio may be taken any number of other electrotype impressions
in relievo. The porous cells may be either unbaked earthenware,
brown paper rolled up and sealed at the bottom and sides, or a lamp-glass
closed at one end with wet bladder.
Fifth Series.
opper not only combines with oxygen, but also unites with the two
permanent gaseous elements hydrogen and nitrogen. According to
Wurtz, the former has a formula of Cu,H, and the latter, by the expe-
riments of Schrötter, is ascertained to have the composition of Cu,N.
This compound, as might be supposed, has a tendency to explode, and
appears to separate into its elements with sudden energy at a tempera-
ture of 509° Fah. Copper filings, or, still better, copper leaf placed
in chlorine gas, is attacked with rapidity, and, if heated in chlorine, takes
fire. Dutch metal, which contains zinc, burns immediately it comes in
contact with chlorine. Copper forms in this way the anhydrous chloride
of copper, CuCl, which may be converted into the subchloride, Cu,Cl,
by heating it to redness in a current of chlorine gas.
A very pretty green colour, passing to shades of blue, and assuming
a variety of tints between blue and green, is displayed on the ceiling of
a room in magnificent waves and miniature billows, which appear to
roll over each other in the beautiful experiment called "the fire cloud."
The apparatus for the performance of this experiment consists of a very
strong copper bottle furnished with a good brass stopcock, pipe, and
jet, and capable of being fitted to a condensing syringe.
To prepare the experiment, a solution of chloride of copper in alcohol
or methylated spirit, in the proportion of an ounce of the chloride of
copper to a quart of the spirit, is filtered or decanted quite clear from
all undissolved crystals, and poured into the copper bottle so as to fill
about one-half of its voluine; the bottle must be scrupulously clean, as
any fine solid particles getting into the jet completely destroy the
success of the experiment. After the solution is poured in, the stop-
cock and copper pipe, passing to within an eighth of an inch of the
bottom, are screwed in and the hand-pump attached.
Air is now
pumped in till the valves of the pump refuse to work, and being removed,
after turning off the cock, a jet with an orifice of about one-twentieth
of an inch is screwed on. Before allowing the alcoholic solution to
escape, it is better to place the copper bottle in a pail of boiling water
until thoroughly but gently warmed, when it may be placed in a ring
holder attached to the body by a strap for the convenience of direct-
ing it at any angle, and a torch being now held to the ceiling of the
room, which should be plaster, and about ten or twelve feet above the
head of the operator, who may wear an old cap or hat, the cock is
turned, the alcohol then takes fire on the ceiling, and being continually
supplied with a finely-divided jet of spirit, which is gently moved over
THE FIRE CLOUD.
289
a space of about ten feet square, it produces the beautiful undulating
and delicate blue-and-green coloured flame already described.
The oxychloride of copper (CuCl,3 CuO,4 HO) is an important pig-
ment, called "Brunswick green," and may be prepared by wetting
sheets of copper with hydrochloric acid and exposing them to the air,
and again repeating the wetting and exposure until the whole of the
copper is decomposed. This pigment is one of the cheapest green
colours sold, and is used very extensively for out-door purposes. The
winral oxychloride of copper is called atacamite.
A
C
B
D


Fig. 172. A. Section of copper bottle with pipe, condensing pump, and stopcock.
The bottle is half full of the alcoholic solution. B. Copper bottle ready for use,
with the jet screwed on and attached to a leathern belt by a ring and hook.
c. Pail of boiling water. G. Use of the copper bottle, from which the jet of aleo-
hol escapes to the ceiling D, where a torch of tow dipped in spirits of wine is held
for a few minutes, till it takes fire properly.
Iodine and bromine both unite with copper, forming proto- and sub.
salts like the chlorides. Fluorine also combines with this metal.
Sixth Series.
If a lump of copper pyrites is placed in a solution of chloride of
barium and connected with a weak voltaic current, it is gradually
changed into sulphuric acid (which unites with the baryta and forms
sulphate of baryta), peroxide of iron, and sulphide of copper, or grey copper
ore. The sulphate of baryta is obtained from the oxidation of the
sulphur in the pyrites, which liberates the iron subsequently oxidized,
and leaves the sulphide of copper.
290
COPPER.
Seventh Series.
A Florence flask filled with copper turnings, and then some roughly-
powdered sulphur sprinkled in so as to be well distributed through
them, affords an interesting example of combustion carried on with-
out the presence of oxygen. When the heat of a spirit lamp is applied
to the flask and its contents, they soon begin to glow with a red heat,
and the copper unites with the sulphur and forms the black and easily-
powdered subsulphide of copper (Cu₂S). This black matter, boiled with
dilute nitric acid, is decomposed, a small portion of the sulphur is oxidized
and forms sulphuric acid, but the larger portion collects in small lumps,
which may be separated by filtration, and present on combustion the usual
indications of sulphur, whilst the blue colour of the solution of copper, in
which a zinc or iron plate can be placed to precipitate the metal, affords
an instructive example of a simple chemical analysis in which the copper
is again recovered in its metallic state. The subsulphide of copper
exists in nature, and is called "copper glance;" and the sulphide (CuS)
is known in mineralogy as "blue copper." Copper pyrites is a mixed
sesquisulphide of iron and subsulphide of copper (Fe,S,, Cu,S), and the
greater proportion of copper is obtained from this mineral, which
assumes, in one of its species, the most lovely appearance of azure blue and
other colours, and is called from that circumstance "peacock copper
ore."
Eighth Series.
Artificial malachite, or bibasic carbonate of copper is prepared by
precipitating a saturated hot solution of sulphate of copper with one of
carbonate of potash; the green precipitate gradually collects, becomes
granular, and after being well washed and dried, is called "verditer
green" or mountain green;" when unmixed with foreign matters, it
has the same composition as malachite, 2 CuO,CO„HO.
66
Ninth Series.
A little nitrate of copper in crystals slightly damped and wrapped up
in tin-foil produces a most energetic action, with the evolution of nitrous
acid fumes, and an exchange of places occurs, by which the tin is united
with oxygen, and the copper precipitated in the metallic state. It is
stated that the production of the nitrous acid fumes is accompanied with
the production of light, but the author has never yet seen that effect pro-
duced, although it is quite possible to suppose that it might do so occa-
sionally, or if performed in an atmosphere of pure oxygen gas.
Tenth Series.
The double sulphate of copper and potash is prepared by neutralizing
a solution of bisulphate of potash with hydrated oxide of copper, and
then evaporating the liquid till a pellicle is formed and the salt crys-
tallizes. When heated on a piece of platinum foil, it melts, and if
ļ
EXPERIMENTS WITH COPPER.
291
allowed to cool, assumes a green and then a light-blue colour, and just
when it might be expected that the fused salt would become solid, a
sudden movement is seen, and decrepitation commences, which is very
distinctly audible, and the whole falls to powder. When the experiment
is made in a porcelain capsule, the same effect occurs, but slower, and if
the cup containing the fused salt is placed on a sounding-board, the
almost musical sounds emitted whilst the crystals are breaking up aro
very curious. Some alteration in the cohesive power of the molecules of
the crystals, brought about by unequal contraction, appear to produce the
effect, which is worthy of more careful examination.

Eleventh Series.
Paper prepared with a pulp containing the phosphate of copper is
slightly blue or bluish-green, and is recommended by Messrs. Glyn
and Appel as a preventive to forgery by the anastatic process. To
show the principle, a sheet of paper or blank cheque may be moistened
with some dilute nitric acid containing a little solution of copper, and
when this is laid upon the zinc plate, as in the ordinary process of
anastatic printing, it undergoes an immediate change; the zinc precipi-
tates the copper, and if the cheque and zinc plate are passed under the
roller, the paper is blackened by the precipitated copper, and adheres
so firmly to the zinc plate, that it cannot be removed without destroying
it, and hence it was stated that, supposing a forger were to attempt to
take an imitation copy of a note printed on this prepared paper, he would
be punished at once by the loss of his property, provided he did not
possess the proper amount of chemical knowledge to extract the copper
before attempting to take the anastatic copy.
Twelfth Series.
Succinate of copper heated in a glass tube till the decomposition is
complete, and then hermetically sealed like the pyrophoric lead
described at p. 252, takes fire spontaneously when shaken into the air,
and very pretty results are obtained by dropping the finely-divided
copper alternately into bottles filled with oxygen and chlorine.
Thirteenth Series.
The tests for copper afford results which cannot be very easily mis-
taken. In the first place, the solutions of this metal, even when very
dilute, present a blue colour, which is rendered further apparent by
evaporating a few drops on the lid of a white porcelain crucible. The
addition of ammonia causes the production of an intense blue colour.
Ferrocyanide of potassium affords a distinct brown tint in solutions of
copper, even when they are diluted to the highest degree. A gallon of
water containing one grain of copper in solution would afford a very
distinct brown cloud with the ferrocyanide of potassium, and the dilu-
tion might be carried higher if the solution is first evaporated in the lid
U 2
292
COPPER.
of a porcelain capsule before applying the test. The precipitated ferro-
cyanide of copper is insoluble in acids. Zinc, iron, tin, lead, all preci-
pitate copper; perhaps a zinc plate affords the most visible results,
because the difference of colour is so very marked, and the oxide of zinc
is white.
In testing bread supposed to contain copper, a zinc plate will detect
a very minute quantity, and all that is necessary is to acidify the bread
with dilute pure sulphuric acid, and leave the zinc therein. The deposited
copper may be scraped off, dissolved, and tested in other ways.
Sulphuretted hydrogen throws down a black precipitate of sulphide
of copper.
Aminonia precipitates and re-dissolves the oxide of copper, producing
an intense blue solution.
When an almost invisible and very minute quantity of copper is pre-
cipitated on an iron plate, it may be detected by moistening the iron
with a solution of chloride of ammonium, and holding it in the flame of
spirit-lamp, when a beautiful green colour is obtained.
a
Mr. Henwood gives a very interesting anecdote, showing the applica-
tion of this simple test: "In the Great Wheal Towan Mine, Cornwall,
they had for years been following a string of quartz, accompanied by a
small quantity of rich copper ore; the walls of this lode were so hard as
to deter them from commencing operations on them for cross cuttings.
At length a man, to preserve his tobacco-pipe, made a small hole in which
he placed it, when to his great surprise a quantity of water of a black
colour issued, which he tried by the usual miners' test-viz., wetting his
fingers in the substance, and applying them to his candle-immediately
the colour of the flame gave unmistakeable signs of copper. This
fortunate discovery laid the foundation of one of the largest fortunes
that Cornwall can boast."
if
A dilute solution of salt attacks copper with considerable rapidity,
and when pickles have been foolishly boiled in badly-tinned copper
vessels, or copper coin placed in the vinegar to impart a fine green
colour to them, a zinc or iron plate will readily separate the copper,
digested for some time with the pickles. The action of a weak solu-
tion of salt on copper is well illustrated by the destruction of the
copper sheathing of ships, which sometimes disappears with astonishing
rapidity.
The corrosive power of the chloride of sodium contained in sea-
water appears to be greatly increased with the voltaic action set up by
the different mechanical conditions of each separate plate of copper.
A voltaic circle is commonly made with a plate of zinc and one of
copper immersed in dilute sulphuric acid, being two dissimilar metals
placed in a fluid which acts rapidly upon one of them. Two plates of
zinc, prepared under precisely circumstances, and immersed in dilute
acid, will however afford a feeble current of electricity, which may
be
rendered apparent by means of a delicate galvanometer needle, such as
that described in the "Boy's Playbook of Science," showing that, if
here is the slightest physical difference between the plates, it is suffi-
DESTRUCTION OF COPPER SHEATHING.
293
cient to set up a voltaic action in which one plate is more rapidly
attacked than the other. It is not difficult to suppose that ships may
be coppered with plates that have been made from different saniples of
copper, and rolled at one or more mills; under these circumstances
there is a specific chemical and mechanical variety in each sheet of
copper, and directly the ship is immersed in sea-water a series of voltaic
currents are set up which greatly promote and increase the chemical
action; and no doubt frequently cause the copper to dissolve more
quickly, although on analysis the sheathing may prove to be made of
pure and good metal.

Fig. 173. Sheathing a Vessel with Copper.

Fig. 174. The Planet Jupiter. (Warren De La Ruc.)
CHAPTER VIII.
TIN, ANCIENTLY-CALLED JUPITER.
4
The character represents the thunderholts of Jove.
It has been truly remarked that the spirit of inquiry is a restless one,
and never slumbers; this greedy desire for knowledge incessantly
urges the mind of man to ask questions which time and observation only
can answer, and certainly one of the favourite queries of those who
study mineralogy is the ever-recurring one of "How were the minerals
deposited in the cracks or fissures of the earth?" In the chapter on
gold, p. 177, it has been explained that, according to the "Plutonic
theory," the crust of the earth has been disturbed by the heaving up of
the melted and intensely-heated mass of rock from below, which, pushing
its way upwards, has displaced and upheaved certain strata, and possibly
produced, by subsequent cooling and contraction, the cracks and fissures
THE ELECTRO DEPOSIT OF MINERALS.
295
alluded to. In the process of time-not to be counted by days or years, but
by centuries-certain solutions of earthy and metallic substances, saline
and mineral waters, have been conveyed into and slowly passed through
these large receptacles, in which crystallization has been set up, and in
consequence of the slowness of the deposition of crystals, like those of
quartz, crystallized silica or sand of remarkable hardness has been
produced. Crystallization has probably been assisted further by elec-
trical attraction, and it is quite possible to conceive that the variable
composition of the walls of these cracks or places, now filled with solid
matter and called lodes, might have set up feeble currents of electricity,
which the late Mr. Crosse, in his original experiments, has shown will
bring about the most singular changes of physical form, whilst Bec-
querel has imitated nature, and produced by slow electric action the
sulphides of silver, copper, lead, and tin in the most perfect and beautiful
crystalline forms.
Dr. Noad, in his most complete "Manual of Electricity," says: "More
recently the weak actions to which Becquerel's attention has been more
particularly directed, are those which commence as soon as the rocks, the
metallic and other substances which occupy veins and beds, come into
contact with the mineral waters that rise from all parts of the earth's
interior. Time then becomes an element in the growth of the crys-
talline substances formed." The following experiments were made by
Becquerel :-
First Series.
A plate of amalgamated zinc surrounding a copper wire was plunged
into a solution of silica in potash. After a fortnight's action, very small
regular octohedral crystals of siliceous oxide of zinc were formed on
the zinc plate.
Second Series.
A lead-copper arrangement was substituted for the zinc-copper, when
anhydrous crystals of oxide of lead were deposited on the lead plate.
Third Series.
Fragments of the mineral galena or sulphide of lead were left for
several years in solutions of chloride of sodium and sulphate of copper
(both of which solutions would occur naturally in the earth, either as
brine-springs or copper-water); the following were the products obtained
by this slowaction, and they were deposited either on the galena or on the
bottom and sides of the vessel. No. 1. Chloride of sodium or common
salt in cubes, cubic octohedrons, and even in octohedrons having great
transparency and very definite forms. No. 2. Chloride of lead in cubes,
and needles slightly yellowish and of a very perfect form. No. 3. Sul-
phate of lead in cuneiform octohedrons, much modified, precisely
resembling the crystalline sulphate of lead of Anglesea. No. 4. Chloro-
sulphate of lead in needles. No. 5. Basic chloride of lead in micro-
scopic crystals, disconnected here and there throughout the whole
296
TIN.
product. No. 6. Sulphuret of copper, black, without an appearance of
crystallization. The whole of these substances covering the piece of
galena gave it the appearance of a specimen from a mineral vein.
Fourth Series.
A voltaic couple formed of a piece of galena surrounded by a pla-
tinum wire placed in a saturated solution of common salt, and sulphate
of copper diluted with three volumes of water, gives rise to the forma-
tion of a considerable quantity of crystallized chloride of lead in cubes,
without any other product.
Becquerel thinks that these reactions take place in nature; rain water
coming in contact with mineral masses and veins formed of metallic
combinations, becomes charged with chloride of sodium and sulphate of
copper, arising (as it does at the present time) from the decomposition
of copper pyrites; these solutions, once in contact with galena, react
upon it weakly, and give rise to those combinations mentioned in the
third experiment of Becquerel; the action is, indeed, progressive, and
reminds one, in its succession, of the old "Joe Miller" of the parson
who told the clerk, who told the sexton, who tolled the bell, one event
succeeding the other with the utmost regularity, and only requiring
time for its fulfilment.
Dr. Golding Bird has also suggested an arrangement by which
nature's processes have probably been still further imitated, and crystals
of metallic copper, suboxide of copper or red copper ore, and oxide of
zinc produced:
"A glass tube, open at both ends, about half an inch in diameter, and
three inches in length, is closed at one end by means of a plug of
plaster of Paris about one-third of an inch in thickness. The tube is
filled with a moderately diluted solution of nitrate or chloride of copper,
and placed inside a cylindrical glass vessel nearly filled with a weak
solution of potash or soda. The leaden leg of a compound lead and
copper arc is plunged into the outer cylinder, and the copper leg into
the tube. The lead slowly dissolves in the alkaline solution, and elec-
tric action is set up; the current traverses the plaster of Paris parti-
tion, and the oxide of copper (precipitated by the slow admixture of the
alkaline solution with the copper salt) is reduced partly to the metallic
state and partly to suboxide, both of which crystallize on the negative
copper leg of the arc. If a solution of oxide of zinc in caustic potash
be substituted for the uncombined alkali in the larger vessel, a very
elegant deposit of oxide of zinc takes place in about eight or ten days,
on the lead or positive plate, while fine crystals of copper and suboxide
are deposited on the copper or negative plate. The detail of these ex-
periments is sufficient to indicate to the student that King Pluto need
not be made responsible for the mineral deposits, although he probably
paved the way for their production by causing those cracks, rents, and
great voltaic cells in the earth which were subsequently filled by the
agency of that potent solvent water which "Old Neptune" is supposed
THE ELECTRO DEPOSIT OF MINERALS.
297
to rule over.
We cannot conceive Pluto and Neptune to be_anta-
gonistic, as fire produces water, and vice versá—they were firm and good
allies, and, like the French and English combination, were great in their
respective specialities, and in the course of time, no doubt, performed
works which an all-bountiful Providence has made subservient to the
wants of man.
Professor Hunt says, however, we must not too hastily decide upon
the agency of electricity being the only cause of the production of
mineral veins, "The probability being, that a set of physical forces
acting on the surfaces of the material particles, which are as yet only
dimly seen by the eye of science, will be found to be the causes regu-
lating the effects under consideration."
"It is certain that in Devon and Cornwall there are distinct indica-
tions of the influences excited by two dissimilar rocks, in producing
the formation of the metalliferous minerals. It is evident that a main
line of direction is observed by mineral lodes, and usually the direction
of lodes containing the ores of lead is nearly at right angles to that of
the copper and tin veins in the same district. In the lead districts of
Wales and of the north of England we find the ores of this metal com-
monly occurring in the limestone bands, and appearing only slightly, if
at all, in the sandstone and shale strata, associated with the limestone.
There are, however, districts, and extensive ones, in which the lead
occurs in the sandstone, and not in the limestone, and there are some in
which the preference appears to have been given to the shales. This
is strikingly shown at the Grassington and at the Cavanley mines.
These facts prove to us that some conditions, beyond those which are
dependent upon the chemical constitution of the rocks, are to be
sought for."
These preliminary remarks upon the probable deposition of the
minerals have been made, because tin, the metal now under consideration,
is rarely found alone, but is more or less associated with ores of copper
and zinc, also with wolfram, arsenical pyrites, &c. The walls of the lode
which contain tin are frequently granite, that being the rock in which
the veins most abound, but it is likewise disseminated in clay and chlorite
slate, gneiss and other metamorphic rock. When procured from veins
it is called "mine tin," but it is obtained in large quantities from
alluvial deposits and drift, like gold; indeed, it is, in searching the
stream works for tin, that the vigilant Cornish miners sometimes dis-
cover little particles of the precious metal gold, which are his perquisites,
and usually preserved in a quill carried about his person, and called
tinner's prilly, or particles. Tin ore obtained from the stream works
is termed “stream tin;" it is a binoxide of tin, SuO,, and is usually
called tin-stone. The hardness of this mineral is taken advantage of;
and when powdered, it is used for polishing metals, glass, &c., under the
name "putty powder." It was the ores of tin that attracted the Pho-
nician traders to ancient Britain, of which they related the most fearful
stories, in order most probably to keep other persons from visiting the
barbarous island. The orcs of tin are called-
298
TIN.
Tin pyrites, or sulphide of tin
Tin-stone, or binoxide of tin, and
Wood tin, or Cornish tin ore .
Containing tin, copper, iron,
sulphur, and earthy matters,
and sometimes zinc.
Containing tin, iron,
Containing tin, iron, and oxygen,
with a little siliceous matter.
Although a certain quantity of tin is brought from Asia, and espe-
cially from the Island of Banca, in the Indian Archipelago, belonging to
the Dutch government, the greater proportion is obtained from Corn-
wall, which has always been celebrated for that metal from the earliest
historic periods. The Romans obtained tin from Britain, in order to
form their bronze helmets, weapons, shields, &c.; and in certain parts
of Cornwall there still remain the mouldering remains and débris of old
furnaces, and slag or dross. The old furnaces are curiously termed
"Jews' works," and the heaps of slag or melted earthy matter derived
from the smelting of the tin ore "Jews' attal." There is one remark-
able heap, called "Attal Saracen," as if tin had been melted at one time
for people who traded with the Saracens, or that the metal had been
made for those who warred with these brave descendants of Ishmael.
The metal tin is mentioned by Moses, and it was from Cornwall that
the Phoenicians obtained this metal which, with copper, formed the As-
syrian and Egyptian bronzes. It is supposed that St. Michael's Mount
and Looe Island were the ancient shipping ports for the tin obtained
round St. Austie, and mentioned by Diodorus Siculus, the famous his-
torian and contemporary of Julius Cæsar and Augustus. Diodorus
says,
"It is something peculiar that happens to the islands in these
parts lying between Europe and Britain; for, at full tide, the intervening
passage being overflowed, they appear islands; but when the sea returns,
a space is left dry, and they are seen as peninsulas." In Mount's bay
the tin-stone has been found in beautiful glassy white and limpid crys-
tals; the author recollects, when a boy, being promised specimens of
these so-called "Cornish or Tin Diamonds," by a gentleman who went
annually to Cornwall, but the promise proved to be illusory. In conse-
quence of the great value of tin-stone, it is very carefully searched for
by the Cornish miners, who always expect to discover tin wherever
granite and clay slate are found in each other's company. The veins of
copper and tin usually run due east and west, whilst those containing
lead (as already mentioned), are generally at right angles to them.
When the tin-stone has been carried away by the decomposition, in ages
past, of the outcrop of the tin lode, through the agency of water and
the continued action of atmospheric causes, it is of course transported
to the valleys and lower levels, and when picked up is called a "shode
stone." With a kind of superior Red Indian sagacity, the miners some-
times succeed in tracing the stone to its source; hence the old Cornish
proverb, “He knows tin." In ancient times they were firm believers in
the use of the "divining rod," made of hazel, and cut in the winter.
Agricola gives us an amusing illustration of the use of this supposed
indicator of the whereabouts of mineral wealth; and not only are persons
THE DIVINING OR DOWSING ROD
299
seen cutting and using the willow " dowsing rod," but others are sinking
shode pits in order to find surer evidence of the presence of tin or
copper. The insecurity of the times is marked by the sword in an old
scabbard, resting against the tree with the wallet and cloak.

A
B
Fig. 175. The ancient Use of the Divining or Dowsing Rod. A. Virgula, or little rod.
B. Fossa, a trench. "Virgula divina" is a Latin idiom, meaning, "When things succeed
without our care, and fall as it were into our laps from heaven."-CICERO.
"In
Sir Walter Scott, in his pleasing novel of "The Antiquary," intro-
duces the subject of the divining-rod in the following passage:
truth, the German was now got to a little copse-thicket at some distance
from the ruins, where he affected busily to search for such a wand as
should suit the purpose of his mystery; and after cutting and examining
and rejecting several, he at length provided himself with a small twig of
hazel terminating in a forked end, which he pronounced to possess the
virtue proper for the experiment that he was about to exhibit. Holding
the forked ends of the wand each between a finger and a thumb, and
thus keeping the rod upright, he proceeded to pace the ruined aisles and
cloisters, followed by the rest of the company in admiring procession.
'I believe dere was no waters here,' said the adept, when he had made
the round of several of the buildings, without perceiving any of those
300
TIN.
indications which he pretended to expect. I believe those Scotch
monksh did find de water too cool for de climate, and alwaysh drank de
goot comfortable Rhine wine; but aha! see them.' Accordingly, the
assistants observed the rod to turn in his fingers, although he pretended
to hold it very tight. 'Dere is water here about, sure enough,' and
turning this way and that way, as the agitation of the divining-rod
seemed to increase or diminish, he at length advanced into the midst of
a vacant and roofless enclosure, which had been the kitchen of the
priory, when the rod twisted itself so as to point almost straight down-
wards. Here is de place,' said the adept, and if ye do not find de
water dere, I will give you all leave to call me an impudent knave.'
The tin lodes are nearly perpendicular, seldom varying more than
twenty degrees, and are sometimes worked to the great depth of 1800 feet.
The "tin floors " occur at much lesser depths, and represent nearly
horizontal strata, containing the tin-stone. Near the Botallack Mine,
in the parish of St. Just, in Penrith, Mr. Henwood states, are the re-
mains of very ancient works called "tin floors." The mineral appears
to have been disposed in irregular kidney-shaped masses or bunches.
When the tin ore is obtained from the mine, it is called "spaller," and
is arranged like copper ores, in heaps of different qualities, according to
the external appearance; it is then dressed," or deprived of the earthy
matters by modern machinery, which is a vast improvement upon the
old methods. As the analysis of a mineral in the laboratory is usually
commenced by pulverizing the substance, so in operations on the grand
scale, the question of "fine division," or pulverization, is one of great
importance, and there are several degrees of fineness obtained either by
1. Crushing mills.
2. Stamping mills.
3. Edge or horizontal mills.
These different mechanical methods of reducing the ore to powder are
like the degrees of comparison; the latter, No. 3, reducing the stony
matter to the most impalpable powder, whilst the ancient stamping mill
appears to take the intermediate position, and has already becă de-
picted at p. 244.
Tin ores are usually subjected to the stamping mill, of which the
best and most complete examples are to be found in Cornwall. Some
idea of the work performed by these huge pestles may be formed when
it is stated that at "Great Hewas " three tons of pulverized tin-stone
per single head or stamp, pass through grates having seventy holes per
square inch every twenty-four hours. A small stream of water, as
shown in the next cut (Fig. 176), carries the particles through the holes
when they are reduced sufficiently fine, or else a motion would have to
be given to the box in which the stamps work, in order to shake the pul-
verized ore through the holes in the iron grates. The stamped ore
passes into receptacles or cisterns, fifteen feet long, ten inches deep,
and eighteen inches wide, having a gradual inclination of about three
quarters of an inch in a foot, and so arranged that whilst one is being
THE MODERN STAMPING MILL.
301
emptied the other may be filling; and the mechanically-suspended
mineral matter carried off by the water is not allowed to escape until it

Fig. 176. Modern Stamping Mill. (Henderson.)
has deposited in some degree the precious freight in pits called "slime
pits." The cisterns already alluded to being inclined, will of course
present the usual results obtained by slowly moving a series of particles
of different specific gravity with a stream of water. The top or part
of the cistern nearest the stampers will retain the best and heaviest tin-
stone, and the lowest division the more earthy particles or "tailings,"
whilst the intermediate portions will make up the series of three
qualities into which the powdered ore is divided.
The head-first or best ore is carried to a square cistern or buddle, also
slightly inclined, and by the skilful adjustment of streams of flowing
water is again divided into two parts, which take, as before, the same
relative position, viz., the best ore at the head and the worst at the tail
of the buddle or square trough.
The head ore is then passed through the "tossing tub," which is
nothing more than a strong iron-hooped tub, into which ore and water
are placed, then stirred up with a shovel, allowed to settle, and the sub-
sidence hastened by striking the sides of the vat with a hammer. When
the water is drained off the powdered mineral is found disposed in layers,
of which the best is this time at the bottom and the lightest or least
valuable at the top. Constant every-day practice enables the workman
to take out each layer separate from the other, either to undergo sub-
sequent washing processes or to be placed on one side for the smelting
process. The "packing kieve" is likewise worked by machinery, the
302
TIN.
hammers being forced outwards by a notched wheel, and brought back
again with a spring against the sides of the vat. Mr. James Hen-
derson, in his valuable paper "On the Methods adopted in Cornwall
in dressing Tin and Copper Ores,” read before the Institute of Civil
Engineers, thus describes the processes of "tossing" and "packing."
A large circular tub, about three feet eight inches in diameter, termed
a kieve, is nearly half filled with water. Two boys or girls then taking
the "work" to be tossed in their shovels, place it gently dcvn the side
of the kieve (Fig. 177) into the water, which is constantly stirred with
a shovel by a third boy, until the water rises (from the addition of the
tin stuff) to within two inches of the top of the kieve. The "tosser"
always stirs the ore in one direction, thus giving it a circular motion.
As the object of "puddling" was to separate the rough, poor matrix
from the tin, so that of "tossing" is to get out the fine matrix. The
"kieve" being now full, the operation of "packing" at once begins, and
merely consists in a boy or a girl striking repeated blows on the edge of
the kieve with an iron bar, one end of which rests on the ground.
About a quarter of an hour is usually occupied in "packing," although
sometimes an hour may be requisite, according to the nature of the stuff.
Fig. 177. Tossing and packing Tin Ores. (Henderson.)
the fine tin stuff taking a longer time to "pack" than that of rougher
quality. The vibration imparted by the process of packing to the
contents of the kieve causes the subsidence of the tin stuff, according to
its specific gravity, with greater regularity than it would have done had
it been at once left at rest after tossing. Directly the process of
packing is completed (which is ascertained by feeling the degree of
hardness of the subsided tin stuff with a shovel hilt), the water is baled
out into a second kieve placed alongside when "tossing;" and some fresh
tin stuff is again carried on. When the author visited the tin works in
the neighbourhood of Tavistock he was much surprised to learn the
value of certain heaps of "dressed tin-stone," which an ignorant person
might very well have passed by as comparatively worthless.
!


1
11.
THE CIRCULAR BUDDLE.
303
The circular "buddle" is used for washing and separating the rich
ore contained in that portion of the tin-stone left in the central part of
the cistern connected with the stamps. The buddle is worked by ma-
chinery, and therefore this description of poorer stamped ore is washed
and subdivided at a cheaper rate than by the hand labour used with the
richest tin ore. The circular buddle is a very ingenious piece of machinery,
and deserves notice here, being not only employed in washing tin, but
also copper and lead ores.

即​痧
​K
a Umf UN CANE HEAD DID DAD BRIOD PARA FIZ QUIN SÜNÜN QADIN CAE
OH I MATTER FULLER DER MANU DU VEZEZ KUD OR AN UNY BAY CAS
LARAT HAND ARIAT KATENTIE AULT MIT QUIT BUT QUE QUAY MOY (PRO ANE VED ALL AN
ŽA BURTON HOGAN WARNA DAM MAX MID FUND CRISIS WAS FOUND CHIC 200 MOCIDE IF
ITA ADIN MUUN KA MA MUNA EAR VA GRUN QEMIA I CIBO TERME CHOICE POSTI
TAL VOMIA INEM ME ON WAY ELOY VOWAN NAVI MOD ZUKU 1915 MON SUP
VO HO HRUNG TULAJAR BILL HOGAN DUNIAUSIO VALGE JOL
RON MAN VOR REBAND KILAUD AAD 12 WASHINJU MUDIARETIN 30 MICA ED IL ADES
IMOBMM MULET ADRE QUE JOM SUNET VON GIN VII 22 JE
Fig. 178. The Round Buddle. A is a conical floor, formed of wood, about eighteen feet
in diameter, on which the stuff is distributed. B is a cone effecting the regular distribu-
tion of the orey matter, and supporting the upper part of the apparatus. c is a cap piece
forming the centre of motion. D. A water wheel for giving motion to the buddle. B. A
funnel perforated with holes, and furnished with an annular trough on the top. FF are
arms for carrying two brushes, which may be balanced by weights G G, as shown, or raised
by a small arbor placed on the top of the beam; H is a launder for conveying slimes from
pit 1. K is a receptacle in which the orey slime, mixed with water, is worked up by the
tormentor, which is a cylinder of wood carrying a number of iron knives. L is a pulley
taking motion from a water-wheel or other prime mover. м is a circular sieve fixed on
the arbor N. The slimes at K are gradually worked over a bridge forming the side of a
catch pit between the sieve м and the tormentor, from whence the stuff passes into the
sieve, and by its rotation the finer particles are strained into the pit 1, whilst the coarser
are discharged with chips and other extraneous matter upon the inclined floor communi-
cating with the launder o. From the pit I the slime flows by the launder H into the funnel
B B, and after passing through the perforated holes, trickles down the sides of the fixed
cone B, when it commences to flow off towards the circumference, leaving by degrees, in
its downward progress, the heavier constituents, whilst the surface is constantly swept
smooth by the brushes, which revolve together with the funnel and vertical shaft, so that
the particles of different densities will be arranged in concentric circles.
The "slimes," or matter washed away by the water, are dressed by
"the trunking process" and racking table (a modified racking buddle
very like that described and used in the time of Agricola, and depicted at
p. 246), and worked by a hand-frame (Fig. 179). It is thus by stamps, and
a complicated series of washing processes that a certain portion of the
small per-centage of tin-stone in the associated matrix is mechanically
304
TIN.
separated from the earthy matter, but this is accomplished with a con-
siderable waste of the actual particles of the tin-stone.

Fig. 179. Hand Frame. (Henderson.)
Common tin is reduced from mine tin, whilst "grain tin," which is the
purest metal, is made from tin obtained from the alluvial deposits or
"stream works." Mr. W. J. Henwood gives a very interesting descrip-
tion of the strata at the "Carnon Stream Works," a few miles from
Truro. The enumeration of the strata is peculiarly instructive, showing
that the tin must have been washed away from distant sources, and
then covered up in process of time with other earthy and sandy matters:
the following is the order of the deposits :-
Sand and mud
Silt and shells
Sand and shells
Silt
Sand and shells.
•
•
in.
0
0 10
0
4302232812
Hooo
0
0
Silt and shells
Silt and stones
0
•
Vegetable matter, wood and leaves
1
6
The tin ground.
12
0
Total depth down to the clay slate rock 64 4
In this excavation were found a number of the antlers of the deer, the
horns of the elk, and the horns of the ox-some of gigantic size and in fine
preservation; these lay in the diluvial strata of earth, stones, and trees.
A rare discovery was made of a human skeleton, which was not sup-
posed to be coeval with the deluge that caused the formation of the
seam; the individual probably perished in the attempt to procure some
PRIMITIVE MINING IMPLEMENTS.
305
of the much-prized mineral; there was a peculiarity about the skull, as
it partook of the Negro form in a marked degree, and was radically dif-
ferent from the European or Asiatic. Near this spot was found a shovel
or spade, formed of a knotty part of the heart of oak; from the appear-
ance of the point it bore evidence of its having been long used. The
handle had disappeared, but had evidently been fitted into a hole
formed in the spade, and tied there by a thong, which was perfect,
owing its preservation, probably, to the tanning qualities of the oak. A
pick also was found, formed of one of the prongs or forks of a stag's
antler;
that had also been tied to the handle, but the tie and the handle
were not discovered. The whole of these primitive implements of
mining before described, together with the skull, bones, and horns, are
now in the possession of the Royal Cornwall Geological Society, and
grace their Museum at Penzance. Human bones and skeletons have
been met with, and occasionally more or less mineralized, in old deserted
galleries in mines. Some years ago human skeletons were discovered
in a compact calcareous rock in the Island of Guadaloupe, and sent by
Admiral Cochrane to Lord Melville, who placed them in the British
Museum; the rock, on examination, proving to be a mere alluvial mass

Fig. 180. Human Remains embedded in an Alluvial Mass.
formed of pieces of coral, that appear to have been thrown up on the
shore by the sea, and afterwards united together by water containing
carbonate of lime in solution.
The great Carnon Stream Tin Works commence near the Carn Brea
Hill, or mountain, in the parish and near the town of Camborne, and
after a circuitous route of about nine or ten miles through the parishes
of Illogan, Redruth, Guennap, Stythians, and Perran, terminates between
the parishes of Feock and Mylor at Restronguet Creek, a branch of
Falmouth Harbour. It has a gradual fall the whole distance, being, in
X
306
TIN.
fact, the bed of a large rivulet, from which the Stream Work derives its
name. Mr. Henwood considers that these deposits of tin ore, &c., are
the strippings of the granite ranges, still in existence, such as Carn
Brea; and he further remarks, "It has long been held that the veins
of tin in Cornwall have not been disturbed by the great deluge which
formed the beds of tin found in the streams, the backs of the lodes pre-
senting no indication of such an event; that is to say, no veins liave
been discovered bearing evidence of having been cut off, as it were, at
the surface, leaving the course of ore bare, which must have been the
case had this occurred. Again, the tin found in the veins is of a dif-
ferent appearance and quality to that found in stream works, the latter
being generally purer and richer, and altogether of another nature. Are
they not the débris of ancient hills, the ruins and wreck of moun-
tains? . . . My own opinion, from close attention to the subject, is,
they are the strippings of the granite ranges still in existence, such as
the Carn Brea,' and other mountains of a similar character, whose tops
and heights are now denuded of the argillaceous and micaceous slates
(both tin and iron-bearing strata) that once covered them.”
•
The above remarks are peculiarly interesting because it is always
most satisfactory to trace results to their causes; and in geological
investigations the sources of alluvial matter will always be a question of
great moment.
The reduction of tin from its mineralized state appears to have been

Fig. 181. Ancient Ingot of Tin marked with an Oriental Cypher, called Jew's Tin, because
the tin mines were farmed by the Jews in the reign of King John.
SMELTING TIN ORES.
307
carried on in Britain by the Phoenicians, or some persons connected
with them; as small blocks and ingots of well-refined tin have been found
in Cornwall, marked with cyphers that have been cast in the metal, and
not stamped or cut after fusion. (Fig. 181.)
The weapons used in the Trojan war must have contained tin, and
"Homer" informs us that it entered into the composition of the armour
of Agamemnon, and the shield of Achilles, being called by the immortal
poet, kaσσiτepos. The second King of Rome, Numa Pompilius, one of
the wisest monarchs that ever reigned, appears to have formed a craft,
or brotherhood, of the artificers in brass, who, no doubt, sometimes em-
ployed tin. If the ancients succeeded in smelting and refining tin, the
moderns have certainly not been backward in appreciating the impor-
tance of this metal, and Richard Earl of Cornwall, the brother of King
Henry III., appears to have made certain special laws for the tin works
and tinners, which were confirmed in a charter by his son Edward on
the payment of a certain tribute, or rent, upon the tin obtained. King
Edward III. confirmed and increased the former charter, and created
the first Lord Warden of the Stanniers of Stannum (tin).
The tin ores of Devon and Cornwall are all smelted, according to the
ancient laws, within the counties where they are mined. Dr. Ure very
properly remarks that private interest suffers no injury from this pro-
hibition, because the vessels which bring the fuel from Wales for smelt-
ing these ores, return to Swansea and Neath laden with copper ores.
"}
The process of smelting tin ores is much more simple than that of
copper ores, and consists in roasting and calcining the powdered and
dressed" tin ore, either with or without charcoal, in a proper rever-
beratory furnace to expel the sulphur and arsenic; and then, after
washing the roasted ore, it is mixed with small coal or culm, and a little
lime or fluor spar, as a flux, and reduced at a higher temperature to the
metallic state, and the tin is cast into blocks. This process is called
smelting. The blocks of tin are again melted, and subjected to the
action of billets of wood thrust into the liquid metal. The decomposi-
tion and escape of steam and gas from the wood causes the melted tin
to enter into a state of violent ebullition, by which a sort of scum rises
to the top, and is skimmed off. The metal is now allowed to settle, and
it spontaneously arranges itself in three strata. The top is the purest
tin, the middle is the second quality, the bottom the very impure metal.
This process is called "refining.'
ور
The arsenic driven off in the roasting process is carefully collected in
condensing flues, and after being again sublimed, is sold in commerce
under the name of white arsenic, or white arsenious acid (As O,). Fre-
quently the tin ores are associated with the mineral called "wolfram,'
which is a double tungstate of iron and manganese; and as the two
minerals are very nearly of the same specific gravity, it is evident that
the mechanical processes of stamping, and washing by the cistern,
buddle, trunk, tossing tub, and racking table, will not separate the
ore of tin from the wolfram. The aid of chemistry has therefore been
invoked, and Mr. Oxland, of Plymouth, has devised a most ingenioas
x 2
308
TIN.
and successful process by which the ores of certain tin mines (that
fetched a lower price than others in consequence of the presence of
wolfram) have been deprived of this impurity, and now command the
highest market price. Tungstate of soda, used by dyers as a mordant,
is produced in this process; and lately the author was informed by Mr.
Oxland that it was likely the metal tungsten would be in demand in
consequence of the remarkable hardness and toughness it imparts to
iron when alloyed with that metal.. Tungstate of soda is now recognised
as an anti-combustible salt, and is applied to muslin and other light
goods in the preparation of non-inflammable fabrics for ladies' garments.
It has long been known that a material of cotton or thread could be in
great measure preserved from the effects of flame by soaking in a solu-
tion of alum or common salt. The expedient is a simple one; but in
practice is liable to objections which, more than any wilful disregard or
carelessness, have prevented its general employment. The fabric that
is soaked in common salt becomes crisp and harsh to the touch, while
that which is saturated with alum is seriously injured by the process,
losing its strength by reason of the action of the salt upon the fibre.
The chemist was therefore called upon to discover a substitute which
would exert no injurious effect upon the colour, the appearance, or the
strength of the material to be rendered non-inflammable. The investi-
gation-one of considerable research and some difficulty-was under-
taken by Messrs. Versmann and Oppenheim, to whom the thanks of the
ladies are due for a long series of experiments made in their behalf. It
was found that borax exerted a powerful preservative effect; but that
the combination of the chemical ingredient impaired in some degree the
strength of the material operated upon. The effect of more than forty
different salts was then tested in the laboratory, the Royal Laundry,
and various muslin manufactories; and a reagent was at length disco-
vered answering in every respect the requirements of the manufacturer,
who, it is to be observed, finishes his muslin without the application of
a lot iron. But more was yet required of the chemist. The amount
of the reagent in question-viz., the phosphate of ammonia required for
a perfect preservative effect-was very considerable; and, moreover, the
salt decomposes under the iron of the laundress, rendering the operation
of ironing after its employment a matter of some difficulty. The sul-
phate of ammonia-a salt only one-fourth the price of the phosphate—
was found advantageously to replace the latter for the purposes of the
manufacturer, a similar preservative action being obtained with a much
smaller amount of the reagent. Both salts, however, are soluble in
water, requiring renewal after washing; and both are liable to the same
objection with regard to the ironing process. A substance was there-
fore required to answer a domestic purpose, and which, while allowing
the hot iron to pass smoothly over the surface of the prepared material,
would afford a perfect guarantee against the effects of flame, without
injuring in any degree the strength or appearance of the fabric. A
salt fulfilling these conditions was ultimately discovered by the above-
mentioned chemists in the tungstate of soda. This salt is now in con-
PROPERTIES OF TIN.
309
stant use in her Majesty's laundry at Richmond; and it is to be
hoped that its application may quickly become general. It remains only
for the wearers of light summer fabrics to require that their goods
shall have undergone the preparation through which their wearers will
be preserved from the dangers resulting from accidental ignition, and
that the laundress also shall employ the tungstate solution of the
domestic difficulty in obtaining the same desirable result of safety
against fire.-Mechanics' Magazine.
Tin, symbolized by the name of the planet Jupiter, in consequence
probably of its brilliancy, and now known by the symbol Sn, approaches
very nearly in its external appearance to silver, having a silvery, but
yellowish-white aspect, which, after slightly tarnishing, remains of a
permanent and dulled white colour. Its specific gravity is 7-285,
stated by some to be 7.9, and this observed difference in the density
of the specimens of tin arises probably from the presence of other
metals, such as lead, arsenic, copper, iron, &c., which, with some others,
are frequently met with in commercial tin. In consequence of its
softness, tin is deficient in elasticity, though, if cast and laminated
between rollers, and consequently hardened, it is found to possess
more elasticity than is usually attributed to it.
The malleability of tin is made available in the manufacture of tinfoil,
which is about0th of an inch thick, and used so extensively in the sil-
vering of mirrors. The tenacity of tin is placed very low down in the scale
of perfection, although it is curious to notice how difficult it is to break
one of the long and almost fibrous, but crystallized fragments of tin;
and probably if the mechanical structure of a bar of tin could be assi-
milated to the condition of bars of fagotted iron in which the fibres arc
all one way-viz., in the direction of the length-it would be found that
tin has a considerable amount of tenacity. In wire made of ordinary
tin, the crossing of the crystals would naturally suggest points of weak-
ness, and this may account for its very low tenacity. When a bar of
tin is bent backwards and forwards, it emits a peculiar crackling sound,
in consequence of the friction of the crystals upon each other; when
heated a little below its melting point, 442° Fali., tin becomes brittle,
and its fragments exhibit a granular or fibrous structure. If melted
tin is poured into a wooden box and quickly shaken, it is reduced to
a powdery state, and becomes finely granulated.
Tin is employed in the manufacture of tin-foil, and especially in the
coating of iron plates, called "tin plate." These iron plates are prepared
by immersion in weak sulphuric and hydrochloric acid, and being well
rubbed with sand and washed with water, are deprived of all oxide or
rust; they are then passed into a bath containing melted tallow, and
from that into one of melted tin, which alloys with, and remains on, the
surface of the iron. The plates are subsequently brought to a smooth
and bright surface by other dippings in baths of tin and tallow.
Bergman discovered that tin and iron form two definite alloys; the one
consisting of two of iron and one of tin, and the other two of tin and
one of iron. Tin plate has that peculiar crystalline appearance conferred
310
TIN.
st
on its surface, called "moirée métallique," by the action of dilute
aqua regia" or nitrohydrochloric acid. If the tin plate is previously
heated in various parts by the flame of a spirit-lamp, each spot where
the flame has been applied becomes the centre of a most beautiful series
of crystals, which are brought out on the application of the diluted
aqua regia.
Before the acid is applied, the "tin plate" reflects the light with
tolerable uniformity; but after being rubbed with the acid the facets
or faces of the crystals of the tin all present minute but different
angles, and the light is unequally reflected.
Bell metal, speculum metal, bronze, Britannia metal, plumbers' solder,
pewter, queen's metal, &c., are all alloys which contain tin. Amalgams
of tin and mercury are used for lining glass globes, or still better, an
amalgam of two parts of mercury, one of tin, one of lead, and one of
bismuth. Tin and mercury are sometimes mixed together, and used
by quacks for stopping decayed teeth, but the intelligence of the pre-
sent age no longer permits educated dentists to use a mercurial
amalgam which may in time produce the most distressing results by
actually salivating the unfortunate person in whose tooth the mercury
has been placed. If teeth are stopped with metal, it should be with
pure gold leaf, which lasts as long as the walls of the hollow tooth re-
main intact. Boilers for dyers are frequently made of tin, also worms
for rectifiers' stills, and many other utensils.
Mr. James Webster, Birmingham, has patented some metallic alloys
containing tin:-No. 1, for reflectors, is composed of nickel three parts,
copper six parts, tin twelve parts, and antimony one part. No. 2, which
may be used for most purposes where white alloys are usually employed,
is composed of two parts of alloy No. 1, twenty parts of tin, and a
quarter part of antimony. No. 3, for bearings of shafts and like pur-
poses, is composed of twenty parts of copper, twenty parts of zinc, and
twenty parts of alloy No. 1.
The forgers of ancient times employed tin in excess for the purpose
of imitating the silver currency. The cruel reign of Nero appears to be
specially represented by base coin containing a large excess of tin.
EXPERIMENTS WITH TIN.
First Series.
The following method of making the assay of a tin ore is recom-
mended by Messrs. Abel and Bloxam, whose valuable work, entitled
The Hand-book of Chemistry," should be in the possession of all
those who wish to acquire a more complete knowledge of chemistry,
and also of the best and most convenient methods of analyzing
minerals and other products:
"The powdered tin ore is heated to redness in order to expel any
water; it is then weighed in a small porcelain boat, and introduced
into a tube of porcelain or hard glass through which a stream of dry
EXPERIMENTS WITH TIN.
311
hydrogen is passed. The tube is heated to dull redness by a gas burner
or a charcoal fire, when the binoxide of tin is easily reduced. The
reduced residue is allowed to cool in the atmosphere of hydrogen, and
the tin dissolved in hydrochloric acid, with the aid of a few drops of
nitric acid. The weight of the tin may then be either directly ascertained
by determining it in the solution, or by calculation from the amount of
silica left undissolved, which is collected for that purpose on a filter,
washed, dried, ignited, weighed; the latter method is obviously appli-
cable only when no other metal but tin is present in the ore."
Second Series.
The combining proportion of tin is 59, and it unites with oxygen
in various proportions, forming definite compounds, the chief of which
are
Protoxide of tin.
Binoxide of tin, or stannic acid
Metastannic acid
•
SnO
SuO₂
Su₂010
Protoxide of tin is prepared by precipitating a solution of chloride of
tin, SuCl, by carbonate of ammonia, and then boiling the precipitate
hydrated oxide of tin, SnO,HO. By this process it is obtained in crys-
talline plates of an olive colour, which, if heated in a porcelain cru-
cible, take fire suddenly and burn like tinder, producing the binoxide
of tin.
Tin stone is the natural mineral form of the binoxide of tin, SnO,
obtained by heating the oxide of tin in air or oxygen, or decomposing
the bichloride of tin with water. This oxide of tin unites with alkalies,
forming stannates, of which the stannate of soda is prepared in con-
siderable quantities as a mordant in dyeing and calico-printing. It is
this oxide which is used in conjunction with glass to form a white
enamel.
Metastannic acid is prepared by slowly heating the hydrated stannic
acid; and also by the action of nitric acid on tin, which attacks the metal
when it is sufficiently diluted, with great rapidity. After the action of
the nitric acid is over, no tin is found in solution, because the metastan-
nic acid is insoluble in water and acid. If some slaked lime is now
stirred in to neutralize the remaining nitric acid, the vapour of ammonia
is immediately rendered evident, when an excess of lime has been added,
and is evolved in such quantity that it can be distinctly perceived by the
nose, and of course affects the turmeric test-paper very strongly. To
account for the production of ammonia it is only necessary to remember
that the water is partly decomposed, and its hydrogen in the nascent
state passes to the nitrogen of the nitric acid, with which it unites and
forms ammonia; this alkali is masked by the excess of nitric acid, and
does not appear until displaced by the lime.
Stannate of the oxide of tin, SnO,SnO,, is another curious example
of the manner in which the same metallic element may perform the part
of acid and base by uniting with different proportions of oxygen gas.
312
TIN.
Third Series.
Chlorine, iodine, brumine, and fluorine all combine with tin. The
chlorides of tin are the most important, and are manufactured and used
in large quantities by dyers. The two combinations of chlorine and
tin are
The chloride of tin
The bichloride of tin.
SnCl
SnCl2
The chloride of tin, SnCl, is usually prepared for commercial purposes
as the hydrated chloride, SnCl,Aq, by digesting hydrochloric acid on
pure granulated tin, with the assistance of a moderate heat; the sa-
turated solution is poured off to crystallize, and the mother liquid
evaporated gently, as long as it affords crystals, which are sold under
the name of "salt of tin." Such is the violence with which dry chlorine
will attack tin, that if passed through a narrow pewter pipe connected
with a receiver, a larger quantity of the vapours of the bichloride are
produced, and the heat generated is so great that the pewter pipe gene-
rally melts down.
The bichloride, SnCl,, is made by distilling carefully six parts of tin
previously amalgamated with one part of mercury, and mixed with
thirty parts of bichloride of mercury. The distillation must be made in
a capacious retort luted to a receiver, and may be conducted over a
charcoal fire, the heat of which should be equalized by surrounding the
lower part of the retort with coarse wire gauze. The bichloride distils

B
C
A
Fig. 182. A. The retort, having the lower part protected by a cap of rough wire
gauze. B. The receiver. c. The charcoal fire. D. The lute, composed of linseed
meal and a little water.
over and condenses in the form of a colourless fluid, known to the old
alchemists by the name of the "fuming liquor of Lebarius," because it
evolves white suffocating fumes when exposed to the air, which contains
invisible steam or aqueous vapour, that unites with it and forms visible
EXPERIMENTS WITH TIN.
313
hydrated bichloride of tin. This curious liquid is rather more than
24 times heavier than water, and its vapour is nine times heavier than
air; it has a great affinity for water, and produces a hissing sound
(similar to that of anhydrous phosphoric or sulphuric acids), when
dropped into water. Like the strongest nitric acid, it has the power of
inflaming turpentine when suddenly poured upon it.
Fourth Series.
Both the chlorides of tin are used in dyeing, and it is by precipitating
a solution of chloride of gold with a mixture of these chlorides of tin
that the finest “purple of Cassius" is obtained.
The solution of the chloride of tin is called by dyers plum spirits,
because it is employed in the preparation of the mixture of the decoction
of logwood and chloride of tin called the plum tub. It is used in calico-
printing, both as a mordant and a deoxidizing agent, and the solution
of protoxide of tin obtained by adding potash or soda to the precipitated
oxide until redissolved, is frequently employed instead of the proto-
chloride.
The deoxidizing power of a solution of chloride of tin is shown directly
it is added to one of the sesquioxide of iron, when the latter is converted
into the protoxide. If a solution of chloride of tin is poured into one
of corrosive sublimate or the bichloride of mercury, it is first reduced to
the state of chloride of mercury, or calomel, and this latter is further
deoxidized and converted into a grey precipitate of minute particles or
globules of metallic mercury, which gradually coalesce and form more
visible indications of the presence of quicksilver. An excess of the tin
salt is absolutely necessary to produce these results.
When exposed to the air, the solution or the crystals of chloride of
tin absorb oxygen, and binoxide and bichloride of tin are produced; but
this is usually prevented in practice by the addition of a little chloride
of ammonium, which forms a double salt, less disposed to change than
the single one. The colours obtained by uniting stannic acid, SnO.,
with the colouring matter, are much brighter than those procured with
the protoxide of tin, probably on account of the gradual change it under-
goes at the expense of the oxygen of the colouring principle. Although
the protoxide is employed in the first place because of its ready solu-
bility, and the facility with which it enters the pores of cotton fabrics;
it may be subsequently converted into the higher oxidized state of
stannic acid by rinsing the cloth containing the protoxide in a weak so-
lution of chloride of lime, which is an oxidizing agent. Stannic acid is
used as a mordant in the form of the perchloride prepared in a peculiar
manner by dissolving tin very slowly, without heat, in weak nitric acid
containing a little chloride of ammonium; this solution is called red
spirits. Pink salt," chiefly used as a mordant with peach wood, is
prepared by adding chloride of ammonium to perchloride of tin, and
evaporating to obtain crystals.
r
The peroxide of tin is employed in fixing the colouring matters
obtained from logwood, peachwood, barwood, Brazil-wood, cochineal,
314
TIN.
&c. The use of this mordant is well shown by dipping a skein of
German white wool (previously well wetted and rinsed in clear water
and squeezed out) into a hot infusion of cochineal; on removing the
skein and washing away the excess of colouring matter, it is found to be
very faintly coloured; but if another skein is previously dipped into a
weak solution of "red spirits," or if a little red spirits are poured
into the hot cochineal whilst the skein is immersed, and the whole well
shaken together by moving the skein in and out of the dye bath, it will
be found to be dyed of a beautiful red or crimson colour, and if rinsed
in water to remove the excess of dye, the colour of the wool is no longer
faint, and is quite fixed.
The important application of the salts of tin in dyeing with cochineal
was discovered by a German chemist of the name of Kuster, who lived at
that locality of concentrated chemical and putrescent odours called Bow,
about the year 1550. His discovery was the means of bringing cochineal
into much larger consumption. Beckman states that the first-mentioned
use of "kermes," or cochineal, in dyeing seems to have been continued
through every century. In the Middle Ages, as they are called, we
meet with "kermes" under the name of vermiculus, or vermiculum; and,
on that account, cloth dyed with them was called vermiculate. Hence
the French word vermeil, and its derivative vermilion, which latter origi-
nally signified the red dye of kermes, but is now used for the sulphide of
mercury or cinnabar.
The chloride of tin is used as "a resist" or means of preventing the
discharge of colour. Thus, if a piece of indigo-blue dyed cotton or linen
cloth is spotted over with a solution of chloride of tin, and then dipped
into one of chloride of lime or bleaching-powder, the latter attacks and
bleaches all parts of the cloth not protected by the tin salt, which
combines with the excess of chlorine, and then undergoing further change,
is converted into stannic acid.
Fifth Series.
The reactions obtained when the protochloride of tin is added to the
various solutions of other metals may all be termed effects of deoxida-
tion, and the following table, taken from Dr. Normandy's excellent
dictionary to his Chemical Atlas," affords some notion of the variety
of experiments that may be performed with this reagent. It is of
course understood that the solution of chloride of tin is quite pure, and
Fresenius recommends the following method of preparing it :-
“Fuse a certain amount of English tin in an iron spoon, and after
having removed the latter from the fire, triturate the fused mass with a
pestle until it has completely solidified. Introduce the powder which
is thus obtained into a flask, pour concentrated hydrochloric acid over
it (always taking care that the tin predominates), and boil the mixture;
dilute the solution subsequently with four times its bulk of water
slightly acidified with HCl, and filter. Pour the filtrate into a phial
containing small fragments of metallic tin, and close it carefully."
EXPERIMENTS WITH TIN.
315
SOLUTIONS OF
Oxide of silver
Protoxide of platinum
Peroxide of platinum
Protoxide of palladium
Peroxide of rhodium
Deutoxide of iridium
Deutoxide of osmium.
Peroxide of gold
...
...
COLOUR.
White
Brown
Brownish red
Dark reddish brown
Black.....
Dark brown
Light brown
Brownish
Purple
REACTIONS.
Precipitate, if the quantity of the
solution of protochloride of tin is
small; a larger quantity produces a
Precipitate of metallic silver.
Colour.
Colour.
Precipitate (Pd); the superincumbent
liquor has a beautiful dark green
colour.
Gives to the red solution a
Colour, but no precipitate.
Precipitate.
Precipitate.
Colour and in more concentrated
solutions
(purple of Cassius)
Deep purple or brown... Precipitate
Brown colour
Brown or yellowish
Sulphurous acid
Protoxide of mercury.....
Grey
Peroxide of mercury
White
Tetrathionic acid
Grey
White
....
Hyposulphurous acid.
Brown
Osmic acid
Brown
Tellurous acid
Black....
Sixth Series.
(Au₂OSnO2), (SnO,SnO2)4HO.
And afterwards
Precipitate.
Precipitate whilst boiling reduced to
globules of mercury.
A small quantity of reagent forms a
Precipitate Hg,Cl; but if an excess
be added,
Precipitate-metallic mercury.
Precipitate.
Precipitate after a time.
Precipitate; soluble in HCl, and the
solution is then brown.
Precipitate of metallic tellurium.
Sulphur combines with tin, and forms the sulphide of tin SnS, and
the bisulphide SnS2. The latter, under the name of "aurum Musivum,"
"mosaic gold," or "bronze-powder," is prepared by first making an amal-
gam of twelve parts tin with six parts mercury, which is then powdered
and mixed with six parts of chloride of ammonium and seven parts of
flowers of sulphur; this mixture is then placed in a mortar or glass flask
with a long neck, arranged in a thin iron pot surrounded with sand over
a proper furnace. A gentle heat is applied until the white fumes cease
to appear, when the temperature is raised to redness, and kept so for
some time. On cooling, the aurum Musivum may be obtained by
breaking the matrass. It is of a beautiful gold colour, and in flaky,
six-sided scales, which are very pretty. The fumes which arise during
the operation should be allowed to escape up the chimney, as they con-
tain mercury, and may produce dangerous results if inhaled; or the whole
process could be conducted over a common fire, by using an iron ladle
as the sand-bath for the Florence flask or matrass. Bronze-powder is
used for touching the edges of painted plaster busts, also by house-
painters and paper-stainers.
Seventh Series.
The tests for tin are classified under two heads-viz., those which
produce a reaction with solution of the protoxide of tin, and those
which affect the binoxide of the metal.
316
TIN.
Sulphuretted hydrogen gas precipitates a dark-brown sulphuret of
tin (SnS) from neutral and acid solutions of the protoxide, but not
from alkaline solutions. The precipitated sulphuret is soluble in
potash and sulphide of potassium, also in strong boiling hydrochloric
acid.
Caustic soda or potash precipitates a white bulky hydrated protoxide
of tin (SnO,HO), soluble in an excess of the alkali.
The carbonates of the alkalies, potash, soda, and ammonia, produce
the same result, but do not re-dissolve the precipitate.
Perchloride of gold added to a solution of the protoxide of tin with
a little nitric acid produces the characteristic precipitation of "purple
of Cassius."
Bichloride of mercury is reduced first to the state of calomel (white),
and then to minute metallic globules, grey in the presence of an excess
of the protoxide of tin.
Bichloride of platinum produces a blood-red colour in solutions of the
protoxide of tin, which very much resembles that obtained by the
addition of sulphocyanide of potassium to a persalt of iron; when
diluted with water, no precipitate occurs, and yet, strange to say, if the
bichloride of platinum is added to a very dilute solution of the chloride
of tin, a reddish-brown precipitate is obtained.
Eighth Series.
The binoxide of tin (SnO,) and persalts of tin being already saturated
with oxygen, do not reduce the other persalts of the metals to the
metallic state. The white powder-metastannic acid (Sn,O,,10HO)
produced, when tin is acted upon by nitric acid, is insoluble in nitric and
dilute sulphuric acids, but concentrated sulphuric, hydrochloric, and
tartaric acids dissolve it.
The precipitate (SnO₂HO) obtained by decomposing bichloride of tin
the fuming liquor of Libavius) with water is white and soluble in alka-
lies and acids; but when strongly heated, it is converted into the inso-
luble form, like the white powder obtained when tin is acted on by
concentrated nitric acid; but the insoluble form is converted into the
soluble by fusion with carbonate of soda.
It has been shown that, in the preparation of certain solutions of tin
for mordants, the bichloride of tin may be obtained in the soluble
form; if sulphuretted hydrogen is passed through a solution of a persalt
of tin, the metal is precipitated as the hydrated bisulphide (SnS,HO),
which is a light yellow precipitate.
The solution of the persalt of tin may be acid or neutral, but if alka-
line, sulphuretted hydrogen does not precipitate the bisulphide; hence
the latter is soluble in the alkaline sulphides and in pure alkalies and
their carbonates. Concentrated and boiling hydrochloric acid slowly
dissolves the bisulphide of tin.
Hydrosulphuret of ammonia produces the yellow precipitate of bisul-
phide of tin, soluble in an excess of the precipitant.
Metallic zinc

SUBMARINE TIN MINE.
317
precipitates tin from solutions of the protochloride or perchloride of tin
which are free from excess of nitric acid. Metallic tin so obtained is a
grey, spongy mass, which, if washed and dried, frequently takes fire
spontaneously on the application of a very moderate heat, and is con-
verted into the oxide of tin. If the solution of tin contains an excess of
nitric acid, the precipitate no longer consists of metallic tin only, but is
a mixture of stannic acid with that metal.
Fig. 183. Botallack Tin Mine at St. Just, near the Land's End, Cornwall, and worked
under the sea for a distance of more than half a mile.

EL EVANS
Fig. 184. The Dutch Alchemist working with Salt, Sulphur, and Mercury. The unprofitable
nature of alchemy is shown by the empty money-bag and the grief of the wife.
CHAPTER IX.
MERCURY.
The ancient sign represents the wand, or caduceus, of the god Mercury.
Ir there was one substance more than another which agitated the
philosophic minds of the earliest alchemists, it certainly was this metal,
MERCURY IN HUMAN REMAINS.
319
which suggested the most delusive hopes of its capability of conversion
into solid silver. Geber, the Arabian prince already alluded to most
respectfully in the chapter on Alchemy, seems to have been convinced
that it was nothing but silver united with moisture, and if he could
only succeed in driving it off, that a solid would be the result. The
chroniclers of his chemical experiments inform us that he succeeded in
changing mercury to a solid, but only with the vexatious result of
the entire loss of all the beautiful characteristics of the metal-its bril-
liancy, volatility, &c., were all entombed in the new form which it
assumed, of a red powder or calx. Geber does not appear to have
understood the nature and composition of the calx or earth, and it was not
till August, 1774, that Priestley discovered the nature of Geber's earth,
and proved it to be a compound of oxygen and mercury.
That the idea of changing mercury by driving off its supposed mois-
ture, was prevalent long after the time of Geber, is shown by the
patient experiments of Boerhaave, who is stated to have distilled mer-
cury twelve hundred times, obtaining, as everybody knows, in these
learned times, only one result-viz., the matter, the mercury, he ori-
ginally started with. What a sensation such a story as this headed,
Mercury in the Bones of a Corpse," related in a French journal,
would have produced amongst the old alchemists; and how many
corpses would have been ruthlessly torn from their last resting-places if
they had only conceived that the principle of transmutation began witk
the corruption and decay of our mortal remains, out of which, Phoenix-
like, the transmuting essence was to arise.
A wealthy farmer, having died, was buried in the tomb where his
father had been interred thirty-five years before-viz., at the burying-
ground of Whittington, near Shrewsbury. A veterinary surgeon, who
presided at the ceremony, took the necessary precautions to prevent
the bones of the father from being broken by the pickaxe of the grave-
digger. On examining the place where they lay, he was surprised to
perceive in the bones of the sternum brilliant particles of a metallic
lustre, and in other parts of the thorax he found a similar appearance.
All these particles being collected together, presented a considerable
quantity of oxide of mercury, which it was easy to reduce to the me-
tallic state. Thus for thirty-five years the mercury had been preserved,
almost without alteration, in the body of the deceased, who had pro-
bably been in the frequent use of the metal during the latter part of
his life." Geoffroy, at the request of an alchemist, placed a quantity of
mercury in an iron globe strongly bound with iron hoops, and then
placed the shell into a furnace. Directly it became red-hot the globe
burst with great violence, and the mercury was dissipated in vapour.
The metals, and especially quicksilver, were favourite objects of
study with the ancients, and, as Dr. Percy remarks, "metallurgy may in-
deed be said to have given birth to chemistry."
The use of quicksilver is traced by learned authors to the ancients,
who were acquainted, according to Pliny, with the process of amalga-
mation for the separation of gold and silver from their associated earthy
320
MERCURY.
matters, and likewise for gilding. Vitruvius details minutely the manner
in which the gold thread was obtained from cloth, with which it was
interwoven; the ashes of the cloth, after burning, were collected in an
earthen vessel and mixed with water and quicksilver, which latter takes
up and amalgamates with the gold. The fluid amalgam is then squeezed
through a cloth, and the gold remains in a compressed mass, and this
is precisely the method of amalgamation adopted by the Australian
gold diggers. "I was invited," says the author of " Life in Victoria,”
"into their dwelling tent, which was as trim and tidy as a woman's hands
could make it (for Mr. N. had another treasure besides his reef); and
while his hospitable wife was preparing luncheon, he amused himself
by exciting my amazement to its uttermost bounds, as he pulled cake
after cake of solid amalgamated gold, like so many Dutch cheeses, from
under his bed, until I absolutely thought either that I was labouring
under an optical illusion, or that he was producing a clever trick, like
that of pulling a market-cartful of cabbages out of a single hat. How-
ever, it was neither the one nor the other, but a palpable reality, a
marvellous fact of the most stubborn description."
Beckman, in his "History of Inventions," remarks: "That it is in
the thirteenth century he finds the first undoubted mention of glass
mirrors covered at the back with tin or lead;" and some time between
that and the sixteenth century, the art of silvering mirrors, as at present
conducted, with the aid of tinfoil and mercury, appears to have been in
common use.
Mercury is found in nature in the metallic and mineralized states, and
is said to be discovered in rocks that belong to the same period as
those which are associated with the coal formations.
The ores are
usually accompanied with iron pyrites, heavy spar, calcareous spar, quartz,
and sometimes copper ore; indeed, the usual constituents of what we
have already termed nature's gigantic electro-deposit cells, veins, or
lodes, are likewise to be found in connexion with them. The following
are the chief ores of mercury :-
Name.
1. Native mercury
•
2. Native amalgam; fluid or
semi-fluid, and solid
3. Mercurial horn ore, or corneous
mercury
4. Mercurial liver ore, or he-
patic ore
5. Red cinnabar or sulphide of
mercury
Constituents.
Mercury.
Mercury and silver.
Mercury, chlorine, oxygen,
sulphur.
Mercury, sulphur, carbon, sili-
ca, aluminum, oxygen, iron,
copper, water.
Mercury, sulphur, with occa-
sionally bituminous matter,
gangue, and water.
Pliny states that the Greeks imported red cinnabar from Almaden, in
Spain, 700 years before the Christian era, and that Rome received
700,000lb. weight annually from the same source. The most important
DISTILLATION OF MERCURIAL ORES.
321
mines which yield quicksilver are at Almaden, Peru, Idria in Austria,
and in the Palatinate on the Rhine.
At Almaden and Idria the cinnabar, after being pulverized and some-
times washed, was formerly placed with some lime in earthenware
vessels, termed cucurbites, which were attached to a long succession of
earthen tubes, called aludels, and already depicted at p. 121. The cucur-
bites or retorts were gradually heated for many days in succession,
and during this time the lime united with the sulphur of the cinnabar,
and the mercury, being volatilized by the heat, condensed as it passed
through the aludels and fell into the proper receivers. The late Dr.
Ure, however, suggested and carried out a great improvement in the
distillation of mercurial ores, and by using common iron gas retorts
and collecting the mercurial fumes with greater care, he was enabled to
prevent waste and economize the cost of the whole process.

E
C
cc. The
Fig. 185. A, A. The retorts. The pipes leading from the retorts marked B.
condenser of cast iron nearly filled with water into which the pipes в dip. D. Pipe
through which the condensed mercury falls into the iron chest E, which is provided with
a float and rod to indicate the quantity of condensed mercury.
Although potassium is soft like wax at ordinary temperatures, and is
liquefied at the low temperature of 136° Fah., there is no other metal
but mercury which remains fluid at common temperatures. The specific
gravity of mercury is very high, and amounts to 13-595; the brilliancy
of this metal is remarkable, and its colour is white and very slightly
tinged with blue. The boiling point of mercury is stated to be about
660° Fah.; and considering the high temperature required to change
the opaque metal to the condition of a transparent vapour, nearly seven
times heavier than air, it is somewhat curious that it should volatilize not
only at ordinary, but even below the common temperatures of our climate.
Mercury placed in a stoppered bottle, with a bit of gold leaf sus-
pended above it, volatilizes slowly, according to the experiments of
Faraday, at a temperature varying between 60° and 80° Fah.; but in
the winter months no trace of vapour (by the test of the whitening of
the gold leaf) could be detected. Karsten, however, states that the
Y
322
MERCURY.
volatilization of mercury is perceptible even at the freezing point of
water; and the experiment of the latter coincides with the generally-
received notion tliat all bodies that assume the state of vapour may
slowly volatilize into the atmosphere, which is supposed to contain a
little of everything capable of being vaporized. It is right to state
Faraday has proved that this is not true in all cases, and he has ascer-
tained, by a series of experiments conducted during four years, that many
chemical bodies which vaporize at 300° and 400° Fah., do not evaporate
when kept in a confined space with water.
Mercury solidifies at a temperature of 40° below zero on Fahrenheit's
scale, and, like water, expands at the moment of freezing; this fact is
proved by the decrease in its specific gravity, which is 13.39 in the solid
state, instead of 13.595. If mercury continued to contract in bulk
C
·D
B
B
C
Fig. 186. Apparatus for freezing Mercury.
whilst freezing, the specific
gravity would be higher than
that of the liquid state.

Henry describes a very simple
and cheap contrivance for freez-
ing quicksilver by chloride of
calcium and snow. The outer
vessel of wood may be twelve
and a half inches square and
seven inches deep. It should
have a wooden cover, rabbeted
in, and furnished with a handle.
Within this is placed a tinned iron vessel, B B, standing on feet which
are one and a half inch high, and having a projection at the top half an
inch broad and one inch deep, on which rests a shallow tin pan, c c.
Within the second vessel is a third, D, made of untinned sheet iron,
without any solder at the corners, and supported by feet two inches
high. This vessel is four inches square, and is intended to contain the
mercury. When the apparatus is used, a mixture of chloride of calcium
and snow is put into the outer vessel A A, so as completely to surround
the middle vessel, B B. Into the latter, the vessel, D, containing the
quicksilver to be frozen, previously cooled down by a freezing mixture,
is put; and this is immediately surrounded by a mixture of snow and
chloride of calcium, previously cooled to zero Fah. by an artificial mix-
ture of snow and common salt. The pan, c c, is also filled with these
materials, and the wooden cover is then put into its place. The vessels
are now left till the quicksilver is frozen. A more elegant, but more
expensive apparatus is that employed for the solidification of carbonic
acid by Robert Addams; when mercury is placed in a dish with ether
and solid carbonic acid, the intense cold produced by the sudden lique-
faction and evaporation of the ether and carbonic-acid gas, solidifies the
mercury, which assumes very much the property of lead and tin so far
as malleability and tenacity are concerned. By means of solid carbonic
acid and ether Mr. Addams succeeded in freezing ten pounds of mercury
in less than eight minutes: the same gentleman placed a lump of solid
carbonic acid in a red-hot crucible for one minute, and afterwards froze a
THE MERCURIAL BAROMETER.
323
pound of quicksilver with it. For use in the Polar regions the thermo-
meters are filled with absolute alcohol instead of quicksilver, which
solidifies and bursts the bulbs under the influence of the intense cold
of those inhospitable and dreary portions of our globe. In the late Sir
John Franklin's second

journey to the shores of
the Polar sea, in 1825-
26-27, a Mr. Kendall
froze some mercury at the
temperature of 52.2°
Fah. in the mould of a
pistol-bullet, and fired it
against a door at the dis-
tance of six paces. A
small portion of the mer-
cury penetrated to the
depth of one-eighth of an
inch, but the remainder
only just lodged in the
wood. Mercury is not
only employed for filling
thermometers, as de-
scribed in the " Boy's
Playbook of Science," p.
360, but is likewise used
in the construction of
barometers or weather-
glasses, which are of such
immense value to cap-
tains of vessels, and also
to fishermen, whose lives
frequently depend on a
foreknowledge of the
state of the weather.
To meet this want
Messrs. Negretti and
Zambra, of Hatton-gar-
den, have constructed a
very cheap instrument,
which they call
call the
"Fisherman's barome-
ter." The scale of the
instrument has been de-
vised by Rear-Admiral
R. Fitzroy, the head of
the Meteorological de-
partment of the Board
of Trade.
NEGRETTI & ZAMBRA,
RISE
FOR
NELY
NW NE
31
DRY 30
OR
LESS
WIND
EXCEPT
WET FROM
NED
LOAC FORETOLD
LONG LAST
323
28
SHORT NOTICE 27
600N PAST
ADD ONE TETI
FOR EACH
LONDON,
FALL
FOR
S WLY
SE S-W
WET
OR
MORE
WIND
EXCEPT
WET FROM
NED
FIRST RISE
AFTER LOW
FORETELLS
STROVOER BLOW
HUNDRED F" ABOVE
THE SEA.
N. & Z.
PATENT
Fig. 187. Negretti and Zambra's Fisherman's Barometer.
Y 2
324
MERCURY.
The instrument that Messrs. Negretti and Zambra had to devise was a
barometer that would bear exposure on a wall, or any other convenient
public place, where it could be consulted by all both day and night;
and also an instrument that might be carried about from one station to
another without fear of the air getting into the vacuum at the top of the
barometer tube, and called the Torricellian vacuum. The new barometer
is made as follows: The frame, which is constructed of oak, is screwed
together with brass screws, so as to render it as durable as possible;
if iron screws had been used, they would be liable to rapid corrosion by
the action of the salt spray more or less pervading the shores of a sea-
CEERNE
Fig. 188. Negretti and Zambra's ingenious ar-
rangement to prevent the air creeping up the
inside of the barometer tube.
port town. The scale, instead
of being made of metal or ivory,
as heretofore, is made of hard-
baked porcelain, the divisions
and figures being indelibly
marked by a patent process oe-
longing to Messrs. Negretti
and Zambra, which is neither
more or less than etching and
blacking in, and burning in at
a low temperature, so as not to
run the risk of altering the
scale; by this process absolute
durability is insured as far as
the divisions and scales are con-
cerned; and the whiteness of the
porcelain is also a great assist-
ance to the dimmed eyes of some
of those who will consult the
instrument. The glass tube is
four-tenths of an inch diameter
internal measurement; thus se-
curing a column of mercury
which is perfectly distinct and
visible. The tubes, with their
mercury, are all boiled an
operation very rarely performed
except in few cases, and then
only by one or two makers, be-
cause the operation is attended
with considerable risk both pe-
cuniary and personal, for as
many as seven or eight large
tubes out of a dozen will break
in boiling. The operation con-
sists in filling a tube with mer-
cury and then holding it over a
pan of charcoal until the mer-

MANUFACTURE OF BAROMETERS.
325
cury boils inside the tube; by this process all the air is expelled. With
respect to the mode of stopping the gradual creeping of the air up
the inside of the barometer, for enter it will, in spite of bags, platina
rings, and all such contrivances, a most ingenious contrivance is em-
ployed, which may be termed a trap. (Fig. 188.) This consists of a stout
bulb of glass welded an inch or so over the open end of the barometer
tube; and, by reference to the preceding woodcut, it will be seen that,
as the air only creeps up between the glass and the mercury, it is
stopped in the top space of the glass bulb or trap, whilst the end of the
barometer tube, being immersed in the mercury, is cut off from com-
munication with the sides of the tube dipping into the cistern of mer-
cury. If the air was permitted to remain in the trap, it might cer-
tainly creep into the main tube at last; but then it must be remem-
bered that, on the first occasion the barometer is turned upside down,
which can be done with perfect safety, all the air goes out of the trap,
and the barometer is as perfect as the first day it was made. It may be
urged that, if the quantity of air that creeps into the tube is so small,
there need not be such a fuss made about trapping it; but it must be re-
membered that the one-thousandth of an inch of air let in at the bottom
of the barometer tube becomes expanded to one inch when it arrives
at the top, or Torricellian space, and hence the absolute necessity of ex-
cluding the smallest bubble of air in a good barometer.
Mercury is employed in the extraction of silver from its ores, like-
wise in the manufacture of looking-glasses, and also in certain processes
of gilding. The science of medicine has long been indebted to mercury
for some of its most powerful remedies, which produce, when taken in
excess, very frightful effects on the human system. One of the pret-
tiest applications of mercury is that lately made by Professor Way, who
employs it for the electrodes of his new electric lamp instead of the solid
poles usually made of carbon. (Fig. 189.) The mercury is contained in an
upper cistern connected with one wire of the battery, and allowed to flow
through a capillary aperture into a closed glass tube communicating
with a lower cistern also connected with the other wire of the battery.
At the moment of contact between the globules of quicksilver falling
from the upper cistern to that retained in the glass forming the upper
part of the lower one, the metal is ignited, and produces a constant
though flickering light, which may be continued for any length of time,
so long as the upper cistern and the battery are kept supplied with their
respective quicksilver and acids.
"Some exceedingly interesting experiments took place off Osborne
House, the beautiful marine residence of her Majesty, in the Isle of
Wight, and also in Cowes-roads, with Professor Way's electric light,
and which we believe are preliminary to more important experiments
about to be carried out by the Government. The principle of the light
is simply the application of electricity to a column or running stream
of quicksilver-in this instance as fine as the point of a lady's needle.
So long as the voltaic battery retains power to act with its wires upon
this column, so long must the light burn-the strongest and purest
326
MERCURY.
light in the known world, and the nearest approach to sunlight that the
skill of the chemist and man of science has yet produced, and this
without actual combustion taking place or the quantity of the mercury
being reduced, the supply of acids to the battery being its sole
expense after its first cost, excepting wear and tear. The Professor
with his apparatus left Portsmouth harbour in a steamer shortly
before dark, and steered direct for Cowes. On the sponson of the
steamer was placed the battery. Abaft the foremast hung one of the
Professor's simple apparatuses as a masthead light. On a moveable
circular platform placed on the vessel's after-hatch a similar apparatus
to the one hung up aloft stood, to which was attached a lens, but both
of them as yet unlit. The apparatus is one of the simplest possible
form, consisting merely of an oval-shaped pair of tubes connected at
each end, with a round hollow globe about the size of an orange, in which
is placed the mercury. The mercury runs from a point to a cup in the
centre, enclosed within a glass tube, and here the subtle liquid is heated
to a white heat as it flows in a fine stream from the upper ball into the
cup, and thence into the lower one, thus producing an indestructible
wick. The wires which connect the battery with the apparatus were
made by Messrs. Silver, and are, perhaps, the most perfect of their kind
yet constructed. These wires are coated with silver, enclosed in india-
rubber, and have an outside coating of braided hemp, the whole pliable
as common packthread. To look at the light, with a view to a close
inspection of the cup, with the naked eye, would be about as useless
as to look at the sun at noonday. A pair of coloured glasses, however,
show that this light, which can only be compared to the sun for its
brilliancy and power, is only of the same circumference as the cup
itself the size of a threepenny silver piece, and of little more diameter.
Midway between the aftermost light and the voltaic battery is a brass
standard a few inches high, with which the wires are connected, and by
pressing a button on the top of this, simple as the key of a piano, the
light can be given in flashes of as long or as short a duration as the
operator pleases. This is, however, more beautifully and correctly car-
ried out by a small instrument of Mr. Way's. It consists of a piece of
clockwork, having in front a revolving disc, the face of which is covered
with numerous holes with pins to fit in as may be required. In front
of the disc are two small cylinders with pistons and arms attached. As
the disc revolves, the pins in its face lift the pistons in the cylinders
and cut off the connexion between the battery and the lighting appa-
ratus, producing flashes of light of any duration that may be required,
with their accompanying intervals of darkness, and admirably adapted
for a revolving light, or as a code of signals for night service. In fact,
there would appear to be no limit to the uses to which this discovery
may be applied, and so simple is it in its manipulation that the choicest
music of the great masters may be henceforth accompanied by expres-
sive flashes of electric light. When the steamer arrived off the Mother-
bank the light aloft was lit by attaching to it the ends of the wires
from the voltaic battery. So soon as the glass tube became sufficiently
WAY'S MERCURIAL ELECTRIC LAMP.
A
B
Z
Z
P
W
327
heated to throw off the mercury from its surface, the light exhibited
its power and beauty, the steamer's masthead light, which was
hoisted in its usual position, appearing but a dull red speck alongside
it. Its effect upon the human countenance was, however, by no means
favourable, casting on all on board the steamer a strange unearthly hue.
Mauve colour, as it has become fashionable to term it, on the ladies'
dresses or bonnets, was brought out by the light with astonishing bril-
liancy. On reaching Cowes-roads, crowded with yachts, and all dis-
playing lights, the contrast between the electric light and those shown
by the yachts was something wonderful. The electric light was shining
in its pale pure brilliancy aloft, while the hundreds of lights displayed
the yachts and by the town
of Cowes, its clubhouse
and hotels, dwindled down
to dull red specks. The
lens applied to the after
light threw broad pathways
of light to and fro as the
lens might be directed,
bathing the low black hulls
of the craft that were in P
the line of light with a
flood of sunshine, as also
the delicate tracery of their
spars and rigging. A boat
which left the steamer here
for one of the yachts was
lighted on its way by the
lens. On the steamer's
return, Norris Castle was
passed, and the light
thrown on its picturesque
front. Ivy-covered towers,
walls, and parapets were
illuminated as with a stroke
from an enchanter's wand.
Off Osborne House the
steamer was stopped for
some time, and the light
must have shown itself
with good effect on the
still waters of the Solent,
in front of the beautiful
marine residence of her
Majesty. The experiments,
which, as already stated,
are only preliminary to
more important ones, were
P
Z
E
D
N
W
Fig. 189. Way's Mercurial Electric Lamp. A. Upper
slowly, in a fine stream, through the minute aperture, c,
iron cistern containing B, the mercury, which falls
on to a little cup not shown, because invisible when the
light is produced, and placed in the glass tube z z z z,
metallic cisterns are cut off from conducting communi-
cation with each other by the non-conducting material
inserted at the pillars P P, P P. w, w. Wires passing to
the voltaic battery.
connected with the lower iron cistern, B. The two
+

328
MERCURY.
considered to have been fully satisfactory. With a light on this prin-
ciple under her bows, the Great Eastern herself might have lighted her
path across the waters of the Atlantic."-The Times.
EXPERIMENTS WITH MERCURY.
First Series.
An assay of mercurial ore, such as cinnabar, is easily made by mixing
together a weighed portion of the powdered mineral with about five
per cent. of dry carbonate of soda and ten of caustic lime, both of
which must also be well powdered and mixed with the ore. The whole
is then put into a combustion tube after a little bicarbonate of soda
has been placed in the closed end of the tube, so that at the last stage
of the process carbonic-acid gas may be disengaged, and acting like a
broom, sweep off any minute portion of mercurial vapour that might
remain and condense in the tube. The mercury is received into a proper
vessel, and its weight compared with the loss of weight in the tube will
give the per-centage of mercury. The cinnabar must of course be
well dried, and any moisture it contains estimated in the usual manner
by drying a weighed quantity in an oven heated a little above 212°.
Mercury is easily purified from zinc, lead, copper, &c., by placing it
in pans containing some dilute nitric acid; and if the latter is kept at a
temperature of about 130° Fah., and the whole frequently stirred, the
metal is gradually purified. The proportions are one part ordinary nitric
acid and two of water.
Second Series.
The combining proportion of mercury is 100, and it unites with
oxygen in two proportions.
The suboxide of mercury
The oxide of mercury
•
Hg,O
HgO
The suboxide was first described by that indefatigable chemist Boer-
haave, who prepared it mechanically by attaching a bottle containing
quicksilver to one of the spokes of a mill-wheel. Homberg, in 1669,
had previously made it in the same kind of manner, but Boerhaave
was the first to call the black powder so obtained "Ethiops per se,"
which appears to be insoluble in water, and has a peculiar coppery
taste. This oxide is also prepared by triturating calomel with a large
excess of solution of potash. It is only interesting to the scientific
chemist because it forms the first of the limited series of oxygen com-
pounds of mercury; but the oxide of mercury presents perhaps the most
peculiar features of interest, not only because it is probably one of the
first chemical compounds ever made by the hand of man, but also
on account of its being the substance by which the original experi-
mentalist, Priestley, discovered oxygen. When mercury is boiled for
some days in a matrass or flask with a long neck open to the air, so
that the volatilized quicksilver is in a great measure condensed in the
EXPERIMENTS WITH MERCURY.
329
upper part of the tube, and falls back again into the body of the matrass,
the mercury is gradually converted into the oxide (HgO), which assumes
the appearance of red scales, and was called by the alchemists "preci-
pitatum per se." It is a very curious fact that, whilst a certain amount
of heat about 600°-facilitates the combination of the mercury and
oxygen, a further increase, amounting to about 900°, decomposes it
again into its elements, mercury and oxygen. The usual method of pre-
paring the oxide is by very carefully heating or calcining minute crystals
of nitrate of mercury, which gives up its acid, and yields the oxide of
mercury in beautiful red scales, called "red precipitate," or nitric oxide
of mercury. This oxide appears to be "dimorphous," or capable of
assuming two forms, having two different colours - viz., yellow or
orange, and red, and we shall have occasion to notice that the same
property belongs to the iodide of mercury, which in one state is yellow,
and in the other red or scarlet, although both have the same chemical
composition.
It is worthy of remark that the oxide of mercury is slightly sensi-
tive to the action of light, and is partially blackened by exposure
thereto.
Third Series.
Chlorine and iodine unite with mercury, and form highly-important
compounds; bromine and fluorine also combine with mercury, but the
resulting salts are of little importance at present. The compounds of
chlorine and mercury consist of
The subchloride of mercury or calomel.
The chloride formerly called bichloride of mercury
or corrosive sublimate
Hg,Cl
HgCl
Calomel is prepared in various ways; it does not seem to have been
made by the alchemists, because Crollius, in the seventeenth century,
speaks of it as a great secret, and as the alchemists were generally in-
clined to describe with considerable prolixity what they discovered, it is
possible to conceive that this compound was, at all events, unnoticed by
them. The commonest and perhaps one of the oldest methods of pre-
paring it, is to rub quicksilver with corrosive sublimate, HgCl, until the
running mercury is said to be killed or rendered invisible by minute
division. This mixture is then placed in an alembic, and being properly
heated in a sand-bath, the impure calomel sublimes, and is subsequently
purified by washing with cold water or re-subliming. There are other
and better modes of preparing calomel, but as this work only pretends
to describe the most popular and characteristic qualities of the metals
and their compounds, these processes cannot be enlarged upon. Mercury,
when heated, takes fire, if plunged into chlorine.
Corrosive sublimate, HgCl, is one of the most ancient chemical com-
pounds, and is described by Geber. It has been known from time
immemorial to the Chinese. One of the most simple processes of making
it is to dissolve the oxide of mercury (HgO) in hydrochloric acid; the
A
330
MERCURY.
oxide dissolves rapidly, and the chloride soon crystallizes; the decom-
position that takes place is very simple, and consists in the combination
of the oxygen of the oxide of mercury with the hydrogen of the hydro-
chloric acid; the liberated chlorine and mercury unite and form corrosive
sublimate. It is this salt of mercury that is used in preserving timber
from the dry-rot by the kyanizing process. Goadby has applied
the following solution to the preservation of the most delicate insects,
and especially butterflies, with complete success. The latter, inclosed
in square glass boxes or troughs containing the solution, and mounted
with a gold border, form the most beautiful and ornamental brooches.
Goadby's Solution.
Corrosive sublimate
Bay salt
Alum
•
•
4 grains
8 ounces
Water.
4 ounces
2 quarts
Corrosive sublimate forms an insoluble compound with albumen, which
is therefore one of the antidotes recommended in cases of poisoning with
this very potent and dangerous salt. It is connected with one of the
most interesting episodes in the life of the late M. Thénard, who on
one occasion, whilst lecturing to his pupils, drank what he imagined to
be water; discovering his mistake, he calmly said, "Gentlemen, I am
poisoned fetch me some eggs." He had taken corrosive sublimate.
Inflammation of the stomach supervened, and for many days he lay in
the most dangerous state; but his house was surrounded by a triple
chain of faithful and admiring pupils, who day and night preserved the
utmost quiet in the streets adjoining his house in Paris. His enthusiastic
reception after recovering from the effects of the poison may be imagined,
but cannot be described.
This well-known story seems to indicate that the whites of eggs are
not to be relied on as a perfect antidote in cases of poisoning with this
salt, and there are other cases where albumen has failed.
"A gentleman staying at a hotel had swallowed some fluid brought
to him by mistake. The mistake originated in the carelessness of a
servant, who, after using the solution of corrosive sublimate for the
purpose of killing certain nameless insects which prevailed in the bed-
steads, had carried the bottle in which it was contained to the bar, and
placed it on the shelf where the cider was kept."
Albumen administered ten minutes after the accident failed to save
his life. Under these circumstances, Dr. Buckler of Baltimore recom-
mended the use of iron-filings, but M. Mialhe has discovered that the
hydrated sulphide of iron will effectually prevent the dangerous effects
of corrosive sublimate. The antidote is prepared by dissolving sulphate
of iron (green vitriol) in at least twenty times its weight of water which
has been boiled to deprive it of air, and then adding enough sulphide of
sodium to precipitate the iron. The hydrated sulphide of iron is to be
1
EXPERIMENTS WITH MERCURY.
331
washed with water by decantation, and may be kept by apothecaries for
use in closely-stoppered or corked bottles filled up with boiling distilled
water. Chemists and druggists would advance their own interests and
those of humanity if they kept on a special shelf the antidotes (in good
order) for all the common poisons.
Iodine unites with mercury to form the iodide HgI, by rubbing
together the equivalent proportions of mercury and iodine. Thus the
equivalent of the latter being 127·1, and the former 100, these would be
the quantities in grains or ounces to be triturated. A little alcohol must
be used to assist the chemical union of the two elements. Iodide of
potassium added to a solution of corrosive sublimate throws down first
of all a dirty-yellow precipitate, which rapidly changes, by stirring, to a
scarlet. If too much of the iodide of potassium is added, the iodide of
mercury is re-dissolved, and this experiment forms one of the most
amusing tricks, if carried out with the assistance of a hollow stirring-
rod (closed at one end by drawing it out to a thin point), which is to
be previously filled with a strong solution of iodide of potassium. If
this rod is stirred in the glass containing a solution of corrosive subli-
mate, no effect is produced until the operator, pretending to get irritated,
thrusts the rod violently down to the bottom, and breaks off the pointed
end, when the iodide flows out and produces the usual colour; and if
the open end of the tube is carefully manipulated with by closing it
with the first finger, just enough of the solution of the iodide of
potassium may be allowed to escape into the corrosive sublimate to
produce the scarlet, and then the whole colour may apparently be
stirred away again by permitting an excess of the iodide to escape
from the end of the rod. These arrangements require careful adjust-
ment beforehand, and some previous trials with the solutions, to ensure
success.
Another amusing experiment may be performed with iodide of potas-
sium and corrosive sublimate, combined with the effects obtainable from


1
COLOURLESS
2
SCARLET.
3
COLOURLESS
4
5
WHITE
BLACK
Fig. 190.
oxalate of ammonia, chloride of calcium, and sulphide of ammonium.
The object is to obtain from five colourless solutions which are to be
332
MERCURY.
}
poured from one glass to the other, a scarlet colour becoming colourless,
then white, and finally black.
Into the first glass a solution of iodide of potassium is placed, suffi-
ciently strong to give a copious precipitate of the scarlet iodide of
mercury when poured into the second glass, which contains a solution
of corrosive sublimate. The scarlet contents of the second are poured
into the third glass, which contains enough iodide of potassium to
redissolve the iodide of mercury, and also some oxalate of ammonium,
so that the contents of the third glass become colourless. By pouring
some of the third into the fourth glass, containing a little solution of
chloride of calcium, a copious white precipitate of oxalate of lime is
thrown down, and this again is masked and lost sight of in the dense
black precipitate of sulphide of mercury, obtained when the solution,
still containing mercury, is poured from the fourth to the fifth glass,
containing some sulphide of ammonium. The fifth glass should be
covered with a glass plate, to prevent the escape of the disagreeable
odour of sulphuretted hydrogen.
The iodide of mercury, when rubbed across a sheet of paper, affords
a beautiful scarlet colour, called "geranium colour," which would be
employed by artists, if they could only depend upon its remaining per-
manent; this, however, is not the case, because the iodide of mercury is
dimorphous and capable of assuming two forms and two colours, yellow
and red; for if the scarlet streak on the paper is carefully heated over
the flame of a spirit lamp, it gradually changes to a primrose yellow,
and when these yellow crystals are subject to any abrasion, such as
scratching them with a pin, the change to scarlet gradually occurs, or
it is produced instantaneously by merely rubbing or breaking down the
yellow crystals, or again restored to the yellow colour by heating the
paper.
Mr. Robert Warrington has investigated this curious change of colour
and form with his usual ingenious acumen, and he states that "when a
quantity of the precipitated biniodide [iodide] is sublimed, the resulting
crystals are very complicated in their structure, consisting of a number of
rhombic plates, of varying size, superposed, sometimes overlapping each
other, and causing considerable variableness in their thickness, but gene-
rally leaving the extreme angle and the two lateral edges clear and well-
defined. The annexed sketch (Fig. 191), taken by the camera lucida from
the field of view of the microscope, will give a better idea of their cha-
racter. The length of these crystals was about 015 of an inch. On
cooling, the first change that is observed is usually a scarlet marking,
commencing at the extreme angle, and extending gradually inwards,
always retaining a perfectly well-defined line in its progress; when this
change has reached so far as the line a b, Fig. 191, the scarlet line will
suddenly shoot along one of the lateral edges, as shown at c d, and in-
stantly the whole mass is converted, in a most rapid and confused man-
ner (which the eye in vain endeavours to follow), to the scarlet colour,
Memoirs of the Chemical Society, vol. i. p. 85,
WARRINGTON'S EXPERIMENTS.
333
the crystal being frequently, if detached, twisted and contorted during
the transition.

с
a
-b
B
Fig. 191. Crystals of Iodide of Mercury.
"In order to obtain these crystals in a more defined and clearly-developed
form, a small glass cell was constructed of two slips of window-glass,
leaving a space of about the thickness of cartridge-paper between the
upper and under plates, in which the sublimations could be readily con-
ducted, and the whole of the subsequent changes at once submitted to
the microscope; by this means, beautifully well-defined and perfect
crystals were obtained, having
the form of right rhombic prisms,
as in the accompanying outlines,
Fig. 192, A and B. The follow-
ing interesting phenomena were
then observed; a defined scarlet
line of varying breadth would
shoot across the crystal as at
1 C, D, E, F, Fig. 192, and then
gradually spread throughout
the whole of its structure, keep-
ing a straight and well-defined
line in its onward progress until
F
6

B
A
C
12
2
E
543
6
the whole had undergone the Fig. 192. Iodide of Mercury in Rhombic Prisms.
334
MERCURY.
change of colour. Nos. 2, 3, 4, 5, in E, and No. 2 in F, are the stages
which the transition had reached at intervals of observation; in many cases,
after the crystal has undergone this metamorphosis, two angles can be dis-
tinctly seen as at E, Fig. 191, and at times two edges are visible, as at c 6,
and D 6, Fig. 192. This observation must of course depend entirely on the
position of the crystal to the eye of the observer. These phenomena prove,
I consider, in the most perfect manner, that the change in the colour of
this compound arises from the plates of the crystal having been separated
from each other by the means alluded to in the direction of their
cleavages; and in further confirmation of this view, the lamina so sepa-
rated may, by the sudden application of heat, be again fused together,
and the yellow colour reproduced without materially altering the dimen-
sions of the crystal, a slight rounding of the edges from partial sublimation
being the only other concomitant." These and other careful experiments
by Mr. Warrington show that the iodide of mercury has two vapours,
which are given off at different temperatures, and also that it is di-
morphous, the yellow form being rhombic, and the scarlet octohedral
with a square base. Besides the iodide of mercury, there is a sub-iodide
(Hg,I), which is a dirty green colour, and prepared by "triturating an
excess of mercury with iodine and a little alcohol."
little alcohol.” This compound
may be fused and sublimed if the operation is performed quickly.
There are also the oxychloride, the oxyiodide, and the oxybromide of
mercury.
Fourth Series.
The compounds of sulphur and mercury are interesting, because they
include the natural compound or mineral called cinnabar, an impure sul-
phide of mercury, and also the well-known pigment which the Chinese
so much delight to use in their gaudy paintings, under the name of ver-
milion. If some quicksilver and sulphur are shaken together in a tube
they quickly unite and form a black compound formerly termed
Ethiops mineral." This experiment offers a good example of the dif-
ference between chemical union and mechanical mixture; for if some
mercury and lycopodium (which is yellow, and looks very much like
sulphur) are shaken together, there is no blackening, but simply a divi-
sion of the particles of quicksilver, and this is of course a "mechanical
mixture." When "Ethiops mineral" is sublimed at a red heat, it forms
a fine red colour, termed cinnabar (HgS) or vermilion. The latter name
is derived from the French word "vermeil," which comes from vermi-
cular, a name given in the medieval period to kermes or cochineal. The
subsulphide of mercury (Hg,S) is, like many other metallic salts, only in-
teresting on account of its analogies, and because it forms one of a large
series of mercurial compounds.
Fifth Series.
The amalgams of mercury are somewhat numerous, and extremely
suggestive of chemical solution; indeed, Joule has obtained definite
EXPERIMENTS WITH MERCURY.
335
compounds of mercury with tin, copper, lead, zinc, silver, and pla-
tinum. Gold is attacked by mercury, and dissolved in it with con-
siderable rapidity, and the author remembers a case of vanity reproved,
in which the mercury contained in a mercurial trough used for certain
experiments with gases that are soluble in water, formed the corrective
agent. A young gentleman who had made himself conspicuous as a
pupil in a chemical class, by wearing a very showy collection of jewel-
lery on his person, was induced by the brilliancy and pretty appearance
of the quicksilver in the open trough, to stir it about with his fingers,
on one of which was a diamond ring; no one made any remark, a few
masonic signs passed between the initiated, but at the end of the dis-
course a sudden cry was heard, Where's my ring? The débris of
this precious ornament remained floating and dissolving in its mer-
curial grave.
The diamond alone remained perfect, and this, if the
author remembers properly, the other mischievous pupils recommended
should be heated red-hot in a crucible with some nitre, and was either
burnt away or lost. Chemical pupils or chemists must not wear jewel-
lery in the laboratory, or fear stained fingers. Some of the most curious
amalgams of mercury are those made with potassium and sodium, and
if some quicksilver is gently warmed and a bit of either of these metals
thrust in on the end of a wire, an intense chemical action takes place
with the evolution of heat and fire. When enough potassium or sodium,
or both, have been added, a solid amalgam is formed, which remains per-
manent only under naphtha, and is slowly oxidized and changed to potash
or soda and running mercury when exposed to the air.
The amalgam for electrical machines is made by melting one part of
zinc with one of tin, and then agitating the liquid alloy with two parts
of mercury placed in a wooden box; when cold, it must be finely pow
dered and kept in a well-corked or stoppered bottle for use.
Mercury is used for amalgamating the plates of zinc used in galvanic
batteries. The best plan is to boil some solution of washing soda in a
saucepan, and first dip the zincs therein for the purpose of removing the
grease with which the plates are more or less covered when they first come
from the zinc worker. They are then to be placed in a weak solu-
tion of corrosive sublimate containing some hydrochloric acid, and are
finally coated with mercury by dipping them into a vessel containing
that metal, or else by pouring some over both sides of the plate and
spreading it well with a stick having a bit of flannel tied on one end
with stout silk. Cotton is soon rotted and destroyed. The plates
must be allowed to drain in any convenient dish, or else a good deal
of quicksilver is wasted.
An amalgam, composed of four parts of mercury and one of bismuth,
is sometimes employed to coat the insides of glass globes used for
ornamental purposes; and if subsequently protected by a varnish com-
posed of wax dissolved in turpentine, they will remain bright for a con-
siderable period.
For scroll and arabesque work, and imitations of illuminated me-
336
MERCURY.
diæval works, "powdered gold," made by first amalgamating gold with
mercury, and then distilling off the latter, is used; the proportions are
one of gold to eight of mercury.
Sixth Series.
The salts of the oxide of mercury are mostly white, and of a very dis-
agreeable metallic taste. If nitrate of mercury, HgO,NO,, is mixed
with an excess of water, it is decomposed into basic nitrate, having a
yellow colour, which, by continual washing, is converted into the red
oxide of mercury.
Solutions of chloride of tin (SnCl) and sulphurous acid (SO2) preci-
pitate metallic mercury from its solution in very minute globules, which
appear grey until they are warmed and coalesce.
The subsalts of mercury are precipitated black by solutions of potash,
soda, and ammonia; salts of mercury, which are persalts, like the
nitrate of mercury or the chloride of mercury (corrosive sublimate), are
precipitated yellow by solutions of potash or soda, and white by ammonia.
The subsalts of mercury are precipitated black both by sulphuretted
hydrogen and sulphide of ammonium; if the black precipitate (Hg,S) is
collected, washed, dried, and heated in a test tube, a sublimate is ob-
tained containing little globules of quicksilver.
With the same tests persalts of mercury are also precipitated black,
and in the use of sulphuretted hydrogen the precipitate becomes white,
then yellow, orange, brownish-red, and black, being truly the embodi-
ment of the living chameleon. If this precipitate is heated in a test tube,
the sublimate contains no globules of quicksilver, and its composition
is HS.
Iodide of potassium throws down a yellowish-green precipitate with
subsalts of mercury; but with persalts a beautiful scarlet precipitate,
soluble in an excess of a solution of iodide of potassium or of chloride
of mercury.
One of the most delicate tests for mercury is, perhaps, the one
pointed out by Smithson. If a little of any oxide or saline compound
of mercury be put in a drop of hydrochloric acid on gold, together with
a little tin, the gold will be amalgamated by the mercury and exhibit a
white spot; and as a gold coin is easily obtained, and hydrochloric acid
is by no means scarce, the test is readily applied, and will detect very
minute quantities of mercury. If the mercury is in a very finely divided
but metallic state, it must be placed on the gold with a drop of nitric
acid evaporated to dryness, and the hydrochloric acid and tin subse-
quently applied.
Frampton recommends the use of finely divided silver when the pre-
sence of soluble chloride of mercury is suspected. The finely divided
silver obtained by electro deposit is boiled with the fluid suspected to
contain the mercurial salt, and being allowed to subside, the liquid is
poured off. The silver is then boiled with potash to remove organic
matter, and washed; it is then heated with ammonia to remove the
EXPERIMENTS WITH MERCURY.
337
chloride of silver, and being finally dried and placed in a glass test tube,
is heated and the mercury sublined, when it forms a metallic ring in
which globules of mercury are clearly visible by a magnifying-glass.
Copper gauze or plate may also be employed, like gold, for the detec
tion of mercury, by the white spot of amalgam left on its surface.

།
Fig. 193. The God Mercury and his Caduceus.
2

Fig. 191. Thirteen-inch Sea-service Mortar.
CHAPTER X.
IRON.
J
The sign represents the lance of Mars, the God of War, together with his shield.
Ir has been well said "that there could be no effectual civilization with-
out iron. From the moment that a people acquires the art of making
it malleable, they cease to be savages, and in proportion as they acquire
skill in its fabrication, they may be said to be civilized." Fortunately
for mankind, therefore, iron is the most abundant, the most widely-dif-
fused, and the cheapest of all metals. It is, at the same time, one of
the most difficult to reduce from the ore to the metallic state, and yet,
with the exception of the savage tribes of America, of Australia, and of
the islands of the Pacific, the art has been in the possession of nearly
all the other people of the world for more than 3000 years.
By reference to the four books of the Mosaic law, it is evident that
Moses (who was born 1635 years before Christ) was acquainted with
iron, and that, consequently, the Egyptians and Phoenicians must have
discovered its use and value many years before his time. Solomon truly
asks, "Is there anything whereof it may be said, See, this is new ?"
and then observes, "it hath been already of old time, which was before
THE ORES OF IRON.
339
us." Moses mentions furnaces for working iron ores, from which it was
extracted, and clearly states that swords, knives, axes, and tools for
cutting stone were then made of that metal.
Dr. Thompson remarks "How many ages before the birth of Moses
iron must have been discovered in these countries, we may perhaps con-
ceive, if we reflect that the knowledge of iron was brought over from
Phrygia to Greece by the Dactyli,* who settled in Crete during the
reign of Minos I., about 1431 years before Christ; yet, during the
Trojan war, which happened 200 years after that period, iron was in
such high estimation that Achilles proposed a ball of it as one of his
prizes during the games which he celebrated in honour of Patroclus.
At that period none of their weapons were formed of iron. Now, if the
Greeks in 200 years had made so little progress in an art which they
learned from others, how long must it have taken the Egyptians, Phry-
gians, Chalybes, or whatever nation first discovered the art of working
iron, to have made that progress in it which we find they had done in
the time of Moses ?"
It would appear from the writings of Diodorus, Pliny, and others,
that the Romans employed iron in the fabrication of their warlike
weapons which chiefly came from Spain. Mr. Aikin states that cutting
and surgical instruments made of bronze, and some few of iron, were
discovered in the excavations at Pompeii, that most interesting of
buried cities, situated about five miles from Mount Vesuvius, and en-
tombed by its eruption A.D. 79. Pompeii remained unnoticed and
almost forgotten for 1700 years, when it was accidentally discovered by
some peasants who were digging a ditch, and since then, the most inte-
resting remains, showing the civilization and luxury of that period, have been
laid bare. Seventeen hundred years are certainly a long period for an expe-
riment on the permanency of bronze and iron implements, and it only
shows that exposure to air (which contains oxygen and moisture) is the
chief cause of that destruction of the useful properties of the iron, and
which we familiarly term "rusting."
The iron discovered naturally, with the exception of those great
masses of the metal containing five per cent. of nickel or cobalt, that have
come to us from unknown sources, and are called meteoric iron, and a
very thin band, or rather foil, of metallic iron, found in America, is all
mineralized or united chiefly with oxygen or sulphur.
The ores of iron are almost endless in variety and composition; in-
deed, iron is the most extensively distributed of all the metals, and it
not only exists in the mineral, but also in the organic kingdoms, being a
constituent of an immense number of natural minerals, and existing
as an essential element in the blood of vertebrate animals. It
would be too tedious to enumerate the names of all the iron ores that
have been discovered and analysed; and therefore, only the most
important, and especially those found and used in Great Britain, will be
mentioned.
* Hesiod, as quoted by Pliny, lib. vii. c. 57.
z 2
340
IRON.
Native iron.
Meteoric iron
•
Iron pyrites
pickel.
Name.
Constituents.
Iron, with occasionally a little
lead and copper.
Iron, with nickel and cobalt.
Iron and sulphur.
Arsenical iron pyrites, or mis-Iron, arsenic, and sulphur.
Magnetic iron ore, or load- A mixture of the two oxides of
stone.
d.}
Specular iron or red hematite,
red ochre, and iron glance.
Brown iron ore, or hydrated oxide
of iron
Umber
•
•
Carbonate of iron
Clay ironstone
iron, FeO+Fe,03.
Iron and oxygen, FeO3.
( Peroxide of iron, water, and
{silica, 2FeO3+3HO.
Oxides of iron and manganese,
water, silica, and alumina.
Protoxide of iron and carbonic
acid.
Impure carbonate of iron, con-
taining oxide of manganese,
lime, magnesia, silica, alu-
mina, peroxide of iron, car-
bon, and sulphur.
It is the clay ironstone which yields, from its varieties of the argilla-
ceous and blackband ironstone, at least nine-tenths of all the iron made
in this country. By a beneficent ordinance of the Creator this is gene-
rally associated with coal and limestone, the two essentials-viz., the
fuel and the flux-required to liberate the iron from its oxygen and earthy
matters. The coal basin of South Wales, which includes an area of
about ten thousand square miles, affords the largest quantity of iron.
A railway journey past Bilston and Wolverhampton reveals to the as-
tonished eyes of the Londoner the wonderful quantities of iron that
must be made in Staffordshire, whilst Shropshire, Yorkshire, Derby-
shire, and North Wales, all coal-producing counties, are also eminent
for the iron they produce. There are very few rules without exceptions,
and so it is with the relationship of coal and iron, and the latter is not
found in any important quantities in the coal fields of Northumberland,
Durham, Lancashire, Leicestershire, and Somersetshire. One of the
most remarkable discoveries of iron ore was made a few years since by
some gentlemen who were out shooting in the neighbourhood of Cleve-
land, in the district of North Yorkshire. One of them happened to
strike his foot against a lump of rocky matter, and stooping down to
look at his enemy, he quickly perceived, from his knowledge of mine-
ralogy, that this lump of stone was a friend in the shape of iron ore,
and that it probably came from a much larger bulk. Returning to the
same spot, he subsequently discovered that the whole of the estate,
consisting of nearly worthless land (at least for agricultural purposes),
THE CLEVELAND IRONSTONE.
341
was full of iron ore, and, it is said, that this fortunate discoverer was
enabled to buy a lease of the land at a very moderate price, which he re-
let at an enormous profit. The Cleveland ironstone turned out to be of
first-rate quality, and was discovered in beds from twelve to twenty feet
thick, and extending for miles, with the greatest facilities for working them.
A rough calculation estimated that ten millions of tons of ironstone
could be obtained by open quarrying alone. The whole of this important
mining district has ready access by railway to the prosperous town of
Middlesborough, which contained only a few scattered houses some
twenty years ago, and is now a town containing from twenty to twenty.
five thousand inhabitants, being just the number which the ancient city
of Pompeii is supposed to have sheltered within its luxurious precincts.
The Cleveland ironstone, like the iron ores of Northamptonshire,
belongs to the oolitic series, and is very similar in its chemical
characteristics to the ores of the Wealden group, which have been
worked in ancient times in Hampshire and Sussex until the charcoal
obtained from the wood of the New Forest and other forests failed to
supply the greedy wants of the iron smelters. Devizes in Wiltshire,
Lancashire, some parts of Yorkshire, and the Isle of Wight supply
limited quantities of the same kind of ironstone. The Cleveland ore
has interspersed through its substance an abundance of fossil shells,
and contains about thirty-three per cent. of metallic iron. When the
author last inquired respecting the treatment of the ore, he was in-
formed that it could be smelted without being previously roasted, and
that the expense of that preliminary operation was therefore saved. The
following is a section of the strata at one of the localities near Cleve-
land, where the ironstone is being worked, viz., at the Loft House Works
belonging to the Earl of Zetland, and leased to a mining company :-
1. Sandstone beds and inferior oolite
2. Shale
3. Hard or cement stone
4. Alum shale
5. Jet rocks
6. Hard composite shale, very sandy
7. Main ironstone bands
8. Sandy shale and iron dogger
9. Shaly sandstone
•
10. Alternations of calcareous sandstone and sandy
shale, generally one sandstone bed
11. Shaly marlstone, slaty sandstone, gradually par-
taking of the nature of the lower lias shale
12. Lower lias shale below the level of the sea
Feet. Fect.
50
10
25
150-185
20
30-50
25
48
10- 58
40
20-60
•
150
578
It is evident, therefore, that the chief portion of the iron discovered in
a mineralized state is oxidized, or rusted, and in order to recover it from
342
IRON.
that condition some cheap material must be sought for which has a
great affinity for oxygen. The substance that answers the condition
required is carbon, in the shape of coal; and as the equivalent propor-
tion of carbon is only 6, a comparatively small quantity is required
when we consider what would be the consumption of this agent if its
equivalent was like that of iodine and amounted to 127.1. But this is
only another addition to the thousands of other illustrations of the
omnipresence of the forethought of the Deity.
The ordinary clay ironstone has been quarried out like stone from
the earliest periods of the history of iron manufacture; but when
steam-power came generally into use, and the demand for iron increased,
mines were sunk into the earth, and nearly all the conditions described
in the mining of coal were adhered to, and especially the mode of
working out the ironstone by the "pillar and stall system," already ex-
plained with reference to coal mining at p. 87. The roof of the
mining gallery is supported by stout props made of fir or larch, which
are removed as the ore is exhausted, and the superincumbent mass
allowed to fall in. The roof is also sometimes further upheld by por-
tions of the useless rock stacked up like a pillar, and called "stons."
The timbering of shafts has already been alluded to in the pre-
ceding chapters on the metals known to the ancients; and the con-
sumption of timber in the mining districts is enormous, practical
miners being fully aware that there is no economy in having a deficiency
of timber in the main ways or places where the miners are actually at
work` Larch and oak are found to last the longest in mines. When
the timber is required for temporary purposes, such as for props and
planks (No. 1, Fig. 195), or is to be abandoned in the mine, Scotch
1
O
2

Fig. 195. Timber Supports used in Mines. No. 1. Props and planks. No. 2.
A "chock" of timber for supporting the roof of a main way,
fir, alder, birch, and beech wood are to be obtained at a cheaper rate.
Sometimes the roof is supported by a number of single props, or, better
still, by "chocks” (No. 2, Fig. 195), which are stacks of wood made up of
pieces two and a half to three feet long, and equal to four strong props, the
TIMBERING OF MINES.
343
breaking strain being transverse to the fibre of the wood; in fact, the
nearer the mining engineer approaches the simplicity of the children's
building toys in which the model timbers are all square and not weakened
by cutting or morticing, the better for the durability of the work. Such
timbering as that depicted in the next cut will of necessity be weakened
by cutting away portions of the solid cross pieces at a and в in Fig. 196,
A
B

B
ДА

A
Fig. 196. Timber Supports used in Mines.
B
and, of course, it is understood that a piece of timber is no stronger
than its weakest point; here the whole block is reduced to the strength
of the points A, B.
It is in the cost of timbering, through bad ventilation, that the
philanthropist gains one of the most telling arguments in persuading
the owner to give his miners a sufficiency of air to breathe. When the
air in a mine is sluggish, the dampness of the air is increased, and it
is charged with different kinds of animal and other odours, which com-
municate their foul condition to the wood, and produce the growth of
a fungus which eats into and destroys the heart of the stoutest timbers;
and it has been declared by a thoroughly practical mining engineer that
at least eighty per cent. of the timber now wasted in mines could be
saved by improving the ventilation. Bad air, fire-damp, and choke-
damp are not the only difficulties the miner has to fight against; there
is the steady infiltration of water, that would in time convert a mine
into a huge cistern well, in which no man could possibly work unless he
went down in a diving-dress, which is, of course, too ridiculous to be
thought of. Hence the necessity for the erection of powerful steam-
engines and complete pumps, by which the water is removed from
mines. It was in the first year of the present century, when bread
had reached famine prices, that the whole future of George Stephenson
was changed by his successful attempt to drain a mine that had baffled
all previous attempts. The great engineer had determined to emigrate,
but this piece of fortune, or rather wisdom, made him at once a
of mark," and he soon rose to an eminent position.
man
Mr. Mark Fryar, one of the eminent lecturers of the Bristol Mining
School, gives the following advice to prevent accidents to life and
property arising from the inundation of coal or other mines-viz.,
344
IRON.
"Accurate surveying and mapping; a due consideration of the lithological
character and properties of the rock dividing the surface or underground
water from the places of the mine in progress; carrying narrow ex-
ploring drifts in the subterranean districts where water may be expected,
with bore-holes in advance, the length of the holes depending very much
on the tenacity and texture of the material being excavated; supporting
water with strong and durable dams where it is to be kept to the rise of
the working parts of the mine, and by leaving pillars of the material
being worked, sufficiently strong to support the roof. When the work-
ings extend under the sea or river, it is of very great importance that
the plans of all underground operations be properly kept, and every ex-
cavation accurately registered, so that when the mine is worked out and
filled up with water, as is the case in a great many instances, the sur-
veyor of a neighbouring mine may, with some degree of confidence and
certainty, direct the workings thereof to a certain point in the direction
of the drowned mine, and thereby save all the expense and much of
the anxiety attendant on a sort of blundering and daring adventure into
the regions of the unworked mineral, only known to be there in certain
quantities by the hearsay of some two or three generations back. What
can be more dangerous than the position of men in the deep workings
of a coal mine, when to the rise of them are lying several thousand cubic
yards of water, only prevented from rushing upon them with fatal
violence by a thin barrier of coal that bleeds," whilst there is no
means of obtaining anything like certain knowledge of the thickness or
strength of such barrier? Where water may be expected from an ad-
joining colliery, the thickness of coal to be left as a barrier against the in-
gress of the water must depend in a great measure on the thickness of the
vein and the strength and fracture of the coal, also on the kind of stone
forming the roof and floor; if these consist of broken fossil shale, with
threads or veins, or of soft clays, the water will be found to percolate through
a considerable thickness of barrier; but if, on the other hand, these con-
sist of hard, compact, siliceous grits, or any other kind of rock of
durable texture, the quantity of coal left between the collieries need not
be so great; thirty to forty yards of barrier is very commonly left
between the workings of extensive collieries."
To prevent a surprise to the main body of an army advancing into an
enemy's country, it is usual to throw out advanced pickets, who feel
their way, so to speak, through the unknown dangers that may harm
them; so, in mining underground, wherever it is known that water has
collected in old and deserted mine workings, the position of which is
not marked out in any plans, or, indeed, wherever it is desirable to keep
a strict watch upon the inroads of water, such as working under a river
or the sea, one or more exploring drifts, or small tunnels, must be
thrown forward in advance of the main working places, and bore-holes
kept about ten or twelve feet in advance of the faces of the drifts, as
shown in the next cut. These borings give ample warning of the pre-
sence of the enemy, who is then attacked and routed with the aid of a
proper system of drainage, which shall conduct the water to the sump
IRON MINES.
C
345
A

C
D
B
-C
Fig. 197. The Pillar and Stall System. A, B. Main working-places. c, c, c, c. Exploring
bore-holes. D, D, D. Brattices, or timber partitions to confine the air (shown by the arrows)
in its proper channel, and make it sweep round the place where the men are working
at A, B. The shaded parts represent the pillar left to support the roof.
or pump-hole, or the water is fairly
shut out by clay dams, constructed by
ramming clay between two strong par-
titions of wood forming a shield, which
effectually secures the miner from his
enemy water.
The construction of the bore-rods,
depth of bore-holes, and formation of
the dam are all minutely described in
Mr. Greenwell's work on "Mine En-
gineering." A colliery or mine is said
to be drowned when filled with water;
and many instances are on record where
from thirty to one hundred men and
boys, with their horses, rolleys, and other
working gear, have been suddenly de-
stroyed by a rapid influx of water cut-
ting off their escape by the main shaft.
It is in the construction of the
pumps, valves, and steam-engines em-
ployed to drain the mines that the me-
chanical genius of the Englishman is
apparent. The common suction-pump,
so called, is not employed in the steady
hard work required to keep a mine dry,
but a pump first invented by Sir Thos.
Morland, about two centuries ago, and
introdued into the Cornish mines by
Murdock. This pump is called the
r
Plunger force-pump," and it acts in
the same manner as the solid plunger
Y
R
F
P

E
Fig. 199. The Plunger Force-pump.
x
346
IRON.
used in Bramah's hydraulic press. Instead of a piston, which fits accu-
rately the interior of a barrel- suction- or lifting-pump, there is a long cast-
iron cylinder, P o, nicely turned and polished on the outside, and of a
diameter somewhat less than the inside of the barrel. This cylinder, called
the “plunger,” slides through a collar of leather, D C, on the top of the
barrel, so arranged that the plunger works air-tight. To prevent the
leather from shrinking by drought, there is usually a little cistern, x Y,
formed round the head of the pump, and kept full of water. The plunger
is forced down by a rod from the connecting beam, which is attached by
numerous clamping bolts to a single piece of pine fitted inside the cast-
iron plunger. At the bottom the barrel of the pump is connected with
two valves, G A M, and H I N, being respectively the inlet and outlet
valves; so that when the plunger is raised, the valve, or door, M, opens and
admits the water, whilst the valve N is shut; and directly the plunger is
forced down again, the latter opens, and allows the water to pass up a
pipe, L K, whilst the valve м is closed. The whole power of the steam-
engine is used to pull up the plunger and connecting rod; and it is usual to
divide the shaft of a mine into a succession of lifts, in which the water
of the lowest lift is delivered to the pump next above it, and so on in
succession until the water reaches the surface. The plunger-pump is
used in all these lifts except the lowest, where the ordinary suction- or
lifting-pump is used, with the view of obviating inconvenience, should
the water, from derangement in the machinery or otherwise, rise so
high in the mine as would make the valves and barrel of a forcing pump
inaccessible, and also on account of the facilities afforded by the lifting
pump in the drainage of the water as the mine is sunk deeper. The
force of the engine is expended in lifting the pump-rods, and the water
is forced out by the weight of the pump-rods in their descent. The
pump-rods of some of the engines, however, are too heavy for the engine
to lift, and part of the weight has to be taken off by one or more levers,
provided with counterbalance weights, placed either at the surface or in
some convenient side excavation. The main pump-rod of Davy's engine
at the Consolidated mines is one-third of a mile in length, and weighs
95 tons: the other rods weigh 40 tons making a total weight of 135
tons; of which 39 tons only are wanted to balance the water in the
pump, and the greater part of the remaining 96 tons is balanced by
weighted levers, or, as they are termed, "balance bobs." The main
pump-rod is usually composed of balks of "Memel timber,” and at in-
tervals, down the sides of the shaft, projecting pieces are bolted on,
which catch upon suitable timbers let into the sides of the shaft to pre-
vent the rod from descending too fast, in the event of fracture above.
The rod is guided at intervals by appropriate frames. "There is some-
things," says Mr. Bourne (who explains the above), "rather primitive in
these expedients, and it appears to us not improbable that the whole of
this cumbrous apparatus will hereafter be superseded by machinery
operating by atmospheric pressure, whereby the pump-rods will be ren-
dered superfluous, and a small engine, working at a quick speed, will
suffice."
PUMPING GEAR.
347
The question of valves is, of course, one of great importance, and the
size of the valve, in large pumping engines, was not formerly so care-
fully attended to as it is now. A large area in the valve-passages, for
the water to flow through, in order that the power of the engine may
not be expended in putting the fluid in motion to fill the pump barrel,
is absolutely indispensable.
The steain-engines used to move the pumps are extremely rough at
many of the mines; but in Cornwall, where fuel is comparatively dear,
the greatest attention has been paid to the economy of coal. The
gigantic cylinders, measuring sometimes ninety inches in diameter, with
the valve, gearing, steam-pipes, &c., are all carefully protected from the
cold by outside jackets composed of a non-conducting material; and the
perfection of them is so complete, that the duty of the Cornish steam-
engines is taken as a perfect example of the accumulation of "horse-
power. The great Watt tested the powers of a horse by ascertaining
the weight which a horse could lift over a pulley out of a well, and with
him horse-power really meant what the words imported. Reduced to a
unit of duty, "one horse-power" is equivalent to 33,000 pounds raised
one foot high in one minute. The next cut, from Bourne's "Treatise
on the Steam-engine," is a fine example of the construction of a steam-

EL FOT
Fig. 199. A Cornish Pumping Steam-engine. (Bourne.)
348
IRON.
engine used for pumping water out of a mine, and contrasts most
amusingly with the contrivances employed for the same purpose some
three hundred years ago.

MMCNAM
Fig. 200. Pumping Apparatus used three hundred years ago. (Agricola, 1550.)
In the Cornish engines, the consumption of fuel has been greatly
decreased since the time of Watt, chiefly by the large application of the
principle of expansion. In a cylinder engine erected at the United
Mines, an average duty of 107,000,000 pounds raised one foot high
by the consumption of one bushel of coals, weighing ninety-four pounds,
was obtained, and this duty has been surpassed by others since its
erection. The introduction of "super-heated steam" will doubtless effect
still greater economical wonders in the consumption of coals.
With this digression on the subject of keeping mines free from water,
we will return to the subject of the preparation and smelting of the
iron ores.
Instead of washing the iron ore in the manner used in dressing the
copper and tin ores, it is merely stacked in great heaps, and exposed for
some months to the weather; during which time the outer crust or coating
of the adhering and comparatively worthless gangue, or rock, cracks and
falls off.
1
1
SMELTING IRON ORES.
349
With very few exceptions, the next step is to roast the ore; this is
performed in a very simple manner by mixing the ore with small-coal,
which is set on fire much in the same manner as the London clay is
now burnt in heaps in the clayey districts surrounding the suburbs of
the great metropolis. By this process the water, the carbonic-acid gas,
and sulphur, if‘any, are driven off, and the ore sustains a loss equal to
about twenty-five per cent., and if examined after burning, is found to
have assumed the form of a dark-red and partially porous mass, in con-
sequence of the protoxide of iron previously united with the carbonic acid
being converted into peroxide, Fe,O,. The amount of carbonate of iron
in the ironstones associated with the coal measures varies from fifty
to eighty per cent., the other constituents being silica, alumina, lime,
magnesia, with minute quantities of sulphur, phosphorus, potash, and
sometimes oxide of manganese.
3*
If the ore consisted only of the peroxide of iron, carbon in the shape
of coal or coke would be sufficient to reduce it; but, since the ore con-
tains a large quantity of earthy matter, the particles of iron, when
reduced, would be held in this porous earthy mass like water in a sponge,
and, although reduced, the metal would remain in an unavailable form.
Something must therefore be mixed with the roasted ore for the purpose
of liquefying the earthy matters, and the cheapest and most convenient
flux is of course limestone. The lime of this substance forms a rough
kind of slag or glass with them, and liberates the iron, which gradually
sinks to the bottom of the great furnace, whilst the liquefied slag floats
on the surface of the heavier iron like oil on water, and is let off by a
tap-hole placed higher up than the orifice from which the liquid iron
flows out.
Dr. Percy, of the Museum of Practical Geology, has made a vast
number of analyses of the slags from iron furnaces, and he reported in
1846 to the British Association the results of his experiments.
These slags were found to contain silica, alumina, lime, magnesia,
protoxides of manganese and iron, potash in small quantity, and sulphur
as sulphurets; phosphoric acid was also found in some of them. The
production, under the peculiar circumstances in which these slags were
formed, of crystalline minerals, in many respects similar to some which are
found in nature, renders the inquiry into their chemical constitution and
physical conditions a peculiarly interesting one; and in its bearings
upon many geological phenomena it is most especially so, as showing the
influences of the long-continued action of high temperature upon
mineral combinations and crystalline structure. With respect to cast-
iron, which will be spoken of more particularly in other parts of this
chapter, a most interesting account is given by Professor Hunt of the
origin of the famous "Berlin cast-iron." At the time when the final
struggle commenced between Prussia and Napoleon, the patriotism of
the Prussian ladies was particularly conspicuous. With the noblest
generosity, they sent their jewels and trinkets to the Royal Treasury to
assist in furnishing funds for the expenses of the campaign. Rings,
crosses, and other ornaments of cast-iron were given in return to all who
350
IRON.
made this sacrifice. They bore the inscription "Gold von eisen" (I gave
gold for iron). Such Spartan jewels are, to this day, much treasured by
the possessors and their families.
WAZE
Dianowy
Fig. 201. Section of a Blast Furnace (Muspratt).
m, m, m, m. Two courses of fire-brick. 1, l. The bad
conducting casing, n, n. Outer casing of solid masonry.
B. The crucible where the melted iron and slag collect,
the bottom of which is called the hearth, formed of a
large firestone supported by masonry, having air-
channels, with open arches, P, P, P, to keep the whole
dry. D. The chimney, approached by a gallery, and gang:
way, with an opening to admit the fuel, &c. o. The throat
or tunnel hole. ▲. The cone or body. B. The boshes.
H, H. Arches leading from one side of the furnace to the
other. E. The tymp, a stone which does not reach the
base and is supported by strong iron-work. A. The
dam-stone. c, c. Perforations a little above the level of
the tymp, to admit the pipes or tuyeres conveying the
blast of air from three pipes.
The furnace used sur-
passes in size all others
that have been previously
described, and is from
forty-five to fifty feet
high, being called the
blast-furnace because it
is fed with a constant and
powerful current of air
forced through the burn-
ing material by proper
blowing machines. The
interior of this furnace,
technically called "the
shirt," consists of the
very bestfire-bricks, about
fourteen inches
inches thick.
The exterior is built of
stone or brick, within
which is a casing of ma-
sonry or fire-bricks, about
fourteen inches
inches thick.
Between the interior and
exterior walls is a space
of about six inches, which
is tightly rammed with a
bad-conducting material,
such as river-sand, brick,
and scoriæ. No expense
or care is spared in build-
ing these furnaces, which
are never allowed to burn
out until they want re-
pairing; so that a well-
built furnace will last
from five to ten years, pro-
vided an unforeseen acci-
dent (arising from care-
lessness in the adjust-
ment of the proportion of
the ore, fuel, limestone,
and blast of air to each
other) does not take place.

HOT AND COLD BLAST.
The crucible on hearth . .
The boshes, inclined at an
angle of from 52° to 59°
The cone or body.
The chimney or mouth.
Feet (height).
. 6 to 61
351
Feet (width).
6 to 61 { bottom, 2 to 21
top, 2 to 3
} 7 to 8
30
to 36
8 to 121/20
12 to 131
31 to 40
The next cut shows the arrangement of the tuyeres or blow-pipes,
the nozzles of which are made hollow and kept cool by a current of
cold water. The air is forced in by an
air-pump, and it has been calculated by
Dr. Percy that no less than six tons of
air pass through an average-sized iron
blast-furnace every hour. Before passing
from the tuyeres, the air is now usually
heated to a temperature of about 600°
Fah., by passing it through coils of red-
hot pipe. With this "hot blast" it is
stated that an increase of about one-eighth,
or of 360° of heat, are obtained in the
furnace. The "hot-blast" was first in-
troduced by Mr. Neilson about thirty
years ago; it has certainly effected à
great saving of fuel, and in many cases Fig. 202. Ground-plan, showing the
enabled manufacturers to increase their
weekly production of iron fifty per cent.;

disposition of the tuyere pipes.
but the following observations of Mr. Henry Hartop, of Doncaster,
addressed to members of the engineering profession, are worthy of
notice; and the paper is dated April, 1847:
ઃઃ
"A View of the present State of the Cold- and Hot-air-blast System of
manufacturing Pig Iron in the Smelting Furnace, as practised for the
last eighteen years.-Notwithstanding great skill and attention have
been used during the whole of this period, the produce from the latter
has regularly fallen in the market until it has reached a difference as
compared with iron of a similar quality made with cold air, of from
17. 15s. to 27. per ton; for the particulars of which, see the Mining
Journal' for the last and present year; although the most unprincipled
means have been taken to uphold the price, as the following notices in
the Mining Journal' of November 21st and December 15th, 1846, re-
spectively will testify:
C
"Hot- and Cold-blast Iron.-A correspondent in Newcastle writes as
follows: Mr. R. Stephenson, the eminent engineer, has been making
a series of experiments upon the relative strengths of hot- and cold-blast
iron, the result of which will be a complete revolution in the iron
trade. Hitherto cold-blast iron has brought a higher price, and has been
considered in every respect superior to hot-blast. Previous, however,
to the construction of the High Level Bridge at Newcastle-upon-Tyne,
352
IRON,
intended to connect the York and Newcastle with the Newcastle and
Berwick Railway, Mr. Stephenson caused more than one hundred ex-
periments to be made with the various sorts of pig iron, the result of
which has been to prove that hot-blast is superior to cold- in the pro-
portion of nine to seven; and, moreover, that pig iron No. 3 is better
than No. 1, which, up to this time, has sold much higher in the market.
-November 21st, 1846.'
'Gateshead Iron Works, Gateshead, Dec. 15th, 1846.
"Hot- and Cold-blast Iron.-Sir, I beg to inform you, and those
who may be interested in this subject, that the article which appeared
in your excellent journal of the 21st of November, from a Newcastle
correspondent, purporting to be the result of experiments made by Mr.
R. Stephenson, the eminent engineer, on the relative strength of hot-
and cold-blast iron, is entirely fallacious and unauthorized. As is evident,
your correspondent has reference to the experiments which are now being
made under my superintendence, by direction of Mr. Stephenson, at these
works. It may be proper to state, that they were adopted with a view to
the selection of the most suitable iron to be used in the construction
of the High Level Bridge. These experiments are as yet by no means
completed; indeed, the number hitherto made does not amount to that
stated by your correspondent; but, so far as they have gone, no one at
present, except myself, is in possession of them, so as to be enabled to
draw a just estimate from the average results. It must therefore be
clear that, from whatever source your correspondent has obtained his
information, it was not only premature but incorrect. Your insertion
of this in your next journal will assist to correct any erroneous impres-
sions that may have been formed by your readers relative to these ex-
periments, and at the same time oblige
"Yours, &c.,
JOHN HOSKING.'
"Since the publication of my paper on this subject in the Mining
Journal' of August 6th, 1842, many circumstances have occurred
corroborative of what I therein state, of which I may here add, that—
"An engineer and iron founder on the most extensive scale in Lan-
cashire, previous to his death, a short time ago, gave an opinion to the
effect that, within the three previous years more machinery in mills and
other manufactories had broken down in his district than in the
twenty-five years preceding, in consequence of using hot-blast iron. The
same is doubtless the case in other manufacturing districts; as in
Yorkshire some of the largest foundries, where it is known that none
but the best cold-blast iron is used, are in a great measure employed in
replacing castings, &c., for those constantly breaking.
"In Staffordshire, at a furnace supplying a bar-iron work with pig
iron, the proprietors thought it worth their while, without any intima-
tion to their customers, to use one out of three blast pipes with hot
air, by which the previous good name of the wrought iron made from
pig iron, the produce of cold blast only, from the same furnace, was at
once destroyed.
"At that notoriously unfortunate mill at Oldham, which fell before
THE BLAST FURNACE.
353
being finished, and by which so many lives were lost, it is but too well
known that every cast-iron bearer in the building was found broken, the
contract for making which bound the founder to use one-third of Staf-
fordshire iron and two-thirds of Scotch, nine-tenths of which is made
with hot air ; and notwithstanding from the above and many similar mis-
fortunes, it is but too well known that the iron in question is altogether
incapable of bearing impact, yet we even now see contracts for railway
chairs being advertised for, in which the above mixture of iron it is
stipulated shall be used; and when this very inconsistent practice is
named to the parties implicated, the only reply made is, 'How can it be
proved that the chairs found broken after almost every railway accident,
whether the chair found so broken was the cause of such accident, or
in consequence of it?' This, I am very happy to find, is at length
bringing about its own cure; and such railway companies as have any
regard whatever for public safety are becoming their own founders,
with a view to prevent so unfit a material being used for railway pur-
poses under their management.
"I shall now only add, as I stated in the paper in question at pages
9 and 10, nearly five years back, that the public only can remedy this
very great evil, inasmuch as the greater the difference in price between
strong and weak iron, the greater the inducement for the founder to use
the latter whenever he is allowed to do so."
Muspratt remarks: "It would appear that greater benefits have
been derived in Scotch than in English furnaces, by the introduction of
the hot blast, either owing to the former having been worked less
economically than the latter, previous to the introduction of the hot
blast, thus making the saving appear greater; or else the fuel used in
Scotch furnaces being weaker than the English, the hot blast has
consequently effected much greater comparative advantages."
A front view of one of these great, heavy-breathing, giant blast
furnaces impresses the observer with something like awe; and if he
waits till night comes on, he is still better able to appreciate the grandeur
of the scene in the lurid and ever-changing blaze which proceeds,
volcano-like, from the mouth of the fiery furnace. Some idea of the
quantity of materials used, and the iron obtained from a single furnace
in one week, may be gained from Dr. Noad's account of the work per-
formed by a furnace at the Cwm Celyn and Blaina Works in South Wales-
From 652 charges of roasted iron ore,
coal, coke, limestone, and forge cinder iron made, 181 tons 9 cwt.
Each charge consisted of coal
Coke
Limestone.
Roasted iron ore
Red ore
Forge cinder
Total.
▲ A
Cwt.
10
63
1
10
•
1
4
32×652=1059 tons 1 cwt.
354
IRON.
So that from 1059 tons 1 cwt. of ore, coal, coke, limestone, and cinder
there were obtained 181 tons 9 cwt. of pig iron; and taking Dr. Percy's
calculation of the consumption of air at six tons per hour, day and
night, for the week of seven days, the quantity of air used amounts to
the astounding quantity of 1008 tons weight; the tonnage of the air
and the raw materials used being nearly equal to each other.
After a furnace is built, it is allowed to stand for some months to
settle and dry spontaneously; and the important step of lighting the
furnace is commenced by piling a quantity of loose fuel outside the
furnace-viz., in the arch forming the breast. The fire, smoke, and

الله.
Fig. 203. The Tapping of the Blast Furnace.
THE BLAST FURNACE,
355
heated air enter the furnace at the orifice left between the tymp and the
bottom of the crucible or hearth, as the damstone at this point of the
operation is left quite open. The fire is maintained for several days and
nights, and when the lower part of the brickwork and masonry has
become sufficiently warın, fuel is thrown in at the chimney, or mouth, till
it reaches the middle of the boshes. In a few days more, the furnace
is entirely filled with coal or coke, and in about fifteen days, or three
weeks, from the time of first beginning to light it, the blast of air is
cautiously set to work, and when the fuel has sunk down to a certain
point, a little roasted iron ore is thrown in; then more fuel, more ore,
flux, and fuel, until the whole of the interior is filled with the necessary
materials in the right proportions, and then the blast is urged to its full
power, and the smelting fairly begins. As the fuel, ore, &c., sink down,
their places are immediately filled up with fresh materials, the only rule
being to keep the blast furnace quite full. In about twelve hours the
contents of the crucible are run off, the blast being frequently suspended
at this time. The slag, or cinder, is allowed to run as an overflow into cast-
iron moulds, to be used for building purposes; and these lumps of slag are
called "donkeys." The lower hole is then tapped, and the liquid
molten iron, which throws up streams of brilliant coruscations and
sparks, flows out in a gradual, one might almost say, dignified manner,
filling up a large number of rough sand-moulds placed in front of the
blast furnace. These moulds consist of parallel trenches, connected by a
main channel. The iron assumes the form of semi-cylindrical bars called
pigs," connected together by those of larger dimensions termed
sows," from which they are subsequently separated.
<<
CC
"The
The eminent authority, Truran, thus briefly describes the changes
which take place inside the furnace, unroasted ore being used:
changes which occur in the descending ore commence with the un-
calcined ores in the throat of the furnace; they lose their moisture and
volatile gases before they reach the level of the boshes, absorbing from
the fuel the necessary caloric for calcination. Below this the ore is
gradually converted from a sesquioxide (FeO3) to a magnetic oxide
(Fe,O), or, as sometimes occurs, into metallic iron, having combined
with a portion of the carbon from the fuel to form the fusible carbide of
iron. From the bottom of the boshes to the level of the tuyères the
reduction of the ore and flux into a liquid mass is completed. The
fusion of the ore and flux occurs at a height of eight or ten inches above
the tuyères, from whence it descends into the hearth. Here the metal,
from its greater specific gravity, falls to the bottom, freed more or
less from the fluid cinder, which floats on the surface and protects it
from the oxidizing influence of the blast.”
No new light was thrown on the theory of the blast furnace until
Professors Bunsen and Playfair made their interesting experiments with
the gases evolved from the incandescent materials at the various parts
of the interior of the blast furnace. It would be impossible here to do
full justice to the voluminous facts recorded by those learned chemists;
but the main facts are, that,-
▲ ▲ 2
356
IRON.
1. There is no carbonic-acid gas in the immediate proximity to the
tuyères, but an abundance of carbonic-oxide gas, which would
have a strong deoxidizing power.
2. Cyanogen and cyanide of potassium are formed at about or near
the blast. The cyanogen being obtained by the direct union of
the carbon of the fuel and the nitrogen of the air of the blast,
whilst the potash is derived from the ashes of the coal, and like-
wise from the iron ore. Cyanide of potassium has long been
known for its powerful deoxidizing qualities; and this chemical
agent no doubt performs most important functions in the general
process of reduction.
3. Ammonia is liberated in large quantities, and Bunsen and Playfair
have recommended that it should be collected, as they calcu-
lated that each 280 cwt. of coal, used every twenty-four hours,
would furnish ammonia sufficient to make 200 lbs. of chloride
of ammonium, or sal ammoniac.
The constituents of the gases evolved from the blast do not appear to
have been as yet applied to any useful purpose, but the heat and im-
perfectly burnt gases are no longer permitted to escape; and in the
best conducted iron works the 813 per cent. of heat formerly wasted in
the air is now conducted, by large pipes six feet in diameter, lined with
fire-brick, under proper boilers; and at the Cwm Celyn works the gases
from two furnaces only more than suffice for the supply of seven boilers,
and for the heating of the hot blast for both furnaces, at a saving of
full 10,000 tons of coal per annum.
The cast or pig iron is not, however, sufficiently pure and malleable
to be employed in the smithy, or in larger operations, and the impurities
it contains may be understood by consulting the following analysis of
pig iron smelted in Scotland with coal :-
Iron
Carbon free
Carbon combined
Silicon
Sulphur.
Phosphorus
Manganese
Slag
•
93.6
1·4*
1.2*
•
1.5
•4
•4
*5
1·0
100.0
It is evident from the above analysis that the iron contains 6.4 per
cent. of foreign substances, of which the sulphur and phosphorus, the
silicon, and excess of carbon must be got rid of before the iron is fit for
useful purposes, such as railway bars and other important castings. This
analysis is not an exceptional case, as may be noticed in the following
* Special notice should be taken of this constituent, in order to understand the principle
of Bessemer's process.
REFINING AND PUDDLING.
357
analyses, made twenty years ago, by the author, of Blaernarvon pig iron
and of Coalbrookdale, Salop, pig iron :-
Iron.
Carbon, free and combined
Silicon
•
Phosphorus
Sulphur
Manganese.
Aluminium
Loss.
Blaernarvon.
Coalbrookdale.
90.39
91.10
...
4.50
5.23
2.10
1.90
1.04
⚫32
•44
•13
1·40
1.20
:
a trace
•13
•10
⚫02
100.00
100.00
It is the object of the refining and puddling processes, with the aid of
mechanical appliances, such as hammers and rollers, to get rid of the
chief portion of the impurities and obtain good commercial bar iron.
The refining process consists in directing streams of air from six tuyères
upon the surface of the bath of liquid iron, so that a portion of the
iron is oxidized, and, combining with the silicon, also oxidized into si-
lica, forms a silicate of iron, which floats upon the surface of the refined
metal. This slag exercises a strong decarbonizing action on the iron,
and when the air has been directed for a sufficient time upon the molten
iron and the slag floating upon the surface, carbonic-oxide gas escapes,
showing the nature of the action that proceeds; finally, the iron is run off
by a tap-hole, and a fresh portion of crude pig iron immediately placed
into the refining furnace.
The process of refining is now generally abandoned in Staffordshire,
the same objects being attained much more economically by the im-
proved method of puddling termed boiling. The following analysis, by
the author, of a specimen of cinder from "boiled pig iron" will give
some idea of the amount of purification by this process, and of the
substances removed from the iron :-
Protoxide of iron
Protoxide of manganese
Silicon
Phosphate of aluminia
Phosphoric acid
Sulphuric acid
78.1
2.96
14.6
.8
2.85
*$8
100-19
The final purification of the refined iron takes place in a reverberatory
furnace by a process originally invented by Henry Cort, who was born
at Lancaster, 1740. This unfortunate gentleman, says his biographer
in the Bristol Mercury, "became an iron merchant at Gosport, in Hamp-
shire, and after erecting works at Fontley, near Gosport, and expending
20,0007. in experiments, it then became necessary to obtain a moneyed
358
IRON.
partner, and he found one in Mr. Adam Jellicoe, chief clerk in the office
of the Paymaster of the Navy. Mr. Jellicoe was a man of reputed
honour and wealth, and he made such a bargain with Henry Cort as
showed the very great advantages which wealth can command. He
advanced, from time to time, 27,500l. to the firm, for which he was to
receive five per cent. interest, half the profits of the trade and patents,
and a salaried appointment for his son at the iron works. The inge-
nious Mr. Cort having at length succeeded in effecting one of his objects,
took out, in 1783, a patent for its manufacture, specifying the patent as
for 'malleablizing cast iron in the air furnace by the cheap flame of
pit coal, without charcoal, blast, bellows, or cylinder.' In the following
year Mr. Cort showed that he had made still further progress, for he
then obtained a second patent, and this time it was for a grooved or
fluted roller, by means of which the large masses of iron at a welding
heat obtained from his puddling furnace were almost instantaneously
elongated into bars, instead of that result being effected by the tedious
and imperfect previous operation of shaping a rough mass into a square
and lengthened figure by incessant blows of a hammer.
"Without noticing further, for the present, the great importance of
these new processes, we now mention that when, in 1784, Mr. Anthony
Bacon, having made an ample fortune, sub-let the mineral tract of forty
square miles of moor and mountain surrounding Merthyr Tydvil, a
lease of which for ninety-nine years, at the trifling rent of 2007. a year,
he obtained in 1755, Mr. Richard Crawshay became the lessee of the
Cyfarthfa and Mr. Samuel Homfray of the Penydarran 'flitches,' as
they have been called, of the great Bacon domain.' At Cyfarthfa
Mr. Crawshay was laboriously forging his ten tons of iron per week
when he chanced to hear of Cort's inventions, and in 1787 he paid a
visit to what he described as 'the little mill at Fontley,' and forth-
with engaged with Mr. Cort for the erection of puddling furnaces and
grooved rollers at Cyfarthfa. The works were duly completed, when,
instead of ten tons, Mr. Crawshay could with ease turn out two hun-
dred tons of excellent bars per week; and Mr. Homfray, soon perceiving
the importance of the new inventions, borrowed from Cyfarthfa the
drawings of the puddling furnaces, the patterns of the rollers, and
Mr. Cort's workmen to teach the operations. Contracts were then
signed by Messrs. Crawshay and Homfray to pay Mr. Cort 10s. per ton
of bar iron as the licence dues for the use of his two patents.
"Everything thus seemed, in 1789, as smooth and clear as an Italian
lake, and Mr. Cort had the fairest prospect of realizing a large fortune
for the benefit of himself and his increasing family. In that year,
however, Mr. Jellicoe, his partner, suddenly deprived himself of life,
and, to all men's astonishment, he turned out to be a public defaulter;
the 27,500l. which he had advanced to the partnership, on the terms
above narrated, having-according to the affidavit of Mr. Alexander
Trotter, Paymaster of the Navy-been moneys entrusted to his deputy
Jellicoe for the discharge of seamen's and other wages. Mr. Trotter
then began to play a part the occult ramifications of which we cannot
}
CORT'S INVENTIONS.
359
here attempt to unfold; but they undoubtedly connected themselves
with that series of transactions for which William Pitt's bosom friend,
Henry Dundas, Viscount Melville, was impeached by the House of
Commons in 1805. Had grace and time been allowed, Cort would
have had no difficulty in supplying Jellicoe's deficiency. He was en-
gaged on lucrative contracts for the navy; the Cyfarthfa and Penydarran
mills were approaching completion; other ironmasters had made and
signed similar contracts with the patentee; and very large returns from
the patents were certain. Only fair and reasonable, then, would it
have been to have taken the security of Cort's licence-dues for the re-
payment of his partner's default. But what did Trotter? He forth-
with sued out the Star Chamber process of an extent in aid against poor
Cort's effects upon an affidavit in which he swore that he had been
informed Cort's prospects and credit were 'much decayed,' so much so
that the summary process taken by the Paymaster of the Navy was
required in order to prevent a total loss of the default ! A disastrous
sale of the Fontley iron-works was the consequence. They produced
only 16,0007.; and, although a jury valued the goodwill of the establish-
ment at 20,000l. more, it was declared that a debt of 11,000%. remained
in the hands of the Crown, for which alleged deficiency Cort's patents
and contracts with the Welsh ironmasters were seized and locked up
in the desk of the Solicitor to the Navy Board. Thence, it is believed,
they never issued to the light of day until they were exhumed to be
burnt, along with heaps of other documents that had each a precious
tale to tell, when Lord Melville and Trotter mutually agreed to adopt
that process for what purpose, viewed in connexion with Melville's
subsequent impeachment, we need scarcely specify. Cort was of course
a ruined man-the victim of deception on every side, and, it seems,
purposely made a victim in order to varnish over for a few more years
the fading characters of other people. Although, however, the patents
were no longer produceable, most people will be disposed to say that
surely the Welsh ironmasters, who were profiting immensely through
the agency of Cort's inventions, ran not back one iota from their word.
Alas for weak humanity when opportunity serves further to enrich the
already rich!—the workers of Cort's patents, bound by deed to faith-
fully recompense him for the same, did not give Cort a shilling of the
licence-dues which they had legally and morally bound themselves to
pay!
CC
Henry Cort's inventions not only enriched many individual firms, but
they were immensely advantageous to the nation. From this time
British iron superseded foreign iron for all our naval purposes, thereby
saving one and a half millions a year previously paid to the iron makers
of Sweden and Russia. It is asserted, too, that the railway system
was rendered possible solely by Cort's invention of the grooved rollers.
Taking these asserted facts into account, the total saving from the
two inventions, in railways and in home-made iron, is estimated at
500,000,000l. since they came into operation in 1785, besides the yearly
saving of 60,000,000l. now progressing. Let it be remembered, too,
360
IRON.
that Cort mainly suffered loss through the malpractices of individuals
in the service of the British Government which existed in his time."
Cort's puddling process consists in liquefying the refined metal with
some cinder rich in oxide of iron on the hearth of a reverberatory
furnace, and at particular periods of the operation stirring and raking
the mass about until the metal, at first very liquid, becomes doughy,
and emits numerous bubbles of carbonic-oxide gas. Experience alone
guides the puddler as to the precise moment when the metal is to be
raked together and formed into masses called puddled balls or blooms;
and all this time the workman, almost in a state of nudity, has to face
the intense heat and glare of the furnace, so that, as he proceeds with
his labour, the perspiration falls from him in such quantity as to pro-
duce a distinct wet circle round the place where he stands. The blooms
are then conveyed to a great hammer, or, still better, to a Nasmyth's
steam-hammer, where, by repeated blows, the slag is fairly squeezed out,
like water from a sponge; it is then passed through heavy rollers, where
it is rolled into bars, and these, when cold, are broken into short
lengths, again heated in a reverberatory furnace, hammered, and rolled,
to form the ordinary British bar iron. In the puddling process there is,
of course, considerable loss, and it is now considered that 22 cwt. of
pig iron is required to make 20 cwt. of puddled bars, and about 213
cwt. of puddled bars to make 20 cwt. of the finished merchant iron.
Some idea of the improvements effected in the puddling process may be
formed from the fact that in Cort's time 33 cwt. were required to pro-
duce the same quantity of merchant iron now made from 24 cwt. of
pig iron.
Messrs. Calvert and Johnstone have made a careful series of re-
searches on the changes that take place in the composition of pig iron,
when converted into bar iron, by which it is clearly proved that the
quantities of carbon, silicon, phosphorus, and sulphur are reduced to
a minimum by the puddling process, and that the hammering, squeezing,
and rolling assist in the segregation of the carbon and silicium.
Since Cort's great invention, which completely revolutionized the iron
trade, of course many other processes have been proposed by inventors,
who have all sought to shorten the steps of the process required to convert
pig into malleable iron or steel. Amongst the most notable processes
are those of Plant and Martin. Mr. Clay's process is so ingenious that
it deserves special notice even in the present work, which professedly
deals with this extensive field of inquiry only in a popular manner.
By the ordinary method, malleable iron is obtained from the ore by
six processes-viz.,
1. Calcining the ore.
2. Smelting in a furnace, by the aid of blast, either cold or heated,
with raw coal or coke for fuel, and limestone as a flux.
tr
3. Refining the "pig” into “plate" iron.
4. Puddling, shingling, and rolling to produce the "rough," "pud-
dled," or No. 1 bars.
CLAY'S PROCESS.
361
5. Cutting up, piling, and rolling, to produce "merchant," or No. 2
bars.
6. A repetition of the same process to make "best," or No. 3 bars.
Mr. William Neale Clay proposes to diminish the number of manipu-
lations by grinding together a mixture of rich iron ore, such as hæmatite,
with about four-tenths of its weight of small coal, so as to pass through a
screen of one-eighth of an inch mesh. This mixture is placed in a hop-
per fixed over a preparatory bed or oven, attached to a puddling furnace

HI
K
H
F

K
Fig. 204. Mr. Clay's Oven and Puddling Furnace. A. The hopper to contain
the charge of ore and coal. B. Preparatory oven or bed. c. Wheels to regulate the
supply of the mixture. D. Shaft to which the perforated bottom в is attached.
F. Chimney, nearly double in area to that which is required on the old system of
puddling. The sectional drawing, K K, is taken through a н.
362
IRON.
of the ordinary form. While one charge is being worked and balled,
another gradually falls from the hopper through the crown, upon the
preparatory bed, and becomes thoroughly and uniformly heated; the
carburetted hydrogen and carbon of the coal combining with the oxygen
of the ore, advances the decomposition of the mineral, while, by the
combustion of these gascs, the puddling furnace is prevented from being
injuriously cooled. One charge being withdrawn, another is brought
forward, and in about one hour and a half, the iron is "balled," and
ready for "shingling" and "rolling." Mr. Clay states that the cinder
produced is superior in quality to that which results from the common
system; it contains from 50 to 55 per cent. of iron, and is free from phos-
phoric acid, which is so injurious in ordinary slags-vide next analysis
(by author) of slag cinder from common puddled iron. The phosphoric
acid chiefly arises from the limestone, nearly every specimen of which
contains a minute proportion.
Protoxide of iron
78.40
Protoxide manganese
2.96
Silica
14.00
Phosphate of alumina
•80
Phosphoric acid
2.85
•
Sulphuric acid
•88
99.89
Loss.
•11
100.00
ore of
When Clay's cinder is re-smelted, it produces as much No. 1 and No. 2
cast iron, and of a good quality, as the ordinary "black band
Scotland. The cast iron produced from the slag (amounting to one-
third of what was originally contained in the ore) is mixed with the ore
and coal in the puddling furnace; and thus, while nearly all the iron is
extracted from the ore, as much wrought iron is produced in a given
time, and at the same cost of fuel, as by the old system. The iron thus
produced is stated to bear a high polish, is very uniform in its texture,
is ductile and fibrous, having more than an average amount of tenacity,
and at the same time appears to be more dense, as it possesses a peculiar
sonorousness resembling that of a bar of steel when struck.
The new process, however, which for the time eclipsed the renown of
all others, is that of Bessemer, and it is perhaps one of the misfortunes
of an inventor, that if a palpable and popular advantage is apparently
to be obtained from his discovery, that the public is rather too hasty
in lauding the invention to the skies, and awarding to it praises for
imaginary advantages which the inventor has never claimed. It is to do
everything, and, like gutta-percha,-which was overdone with praises
and declared good for every purpose, not even excepting, as "Punch
said, coughs, colds, and bunions,-the new process of Bessemer was at
once to carry everything before it, and completely revolutionize the whole
BESSEMER'S PROCESS.
363
iron trade, and really the arguments in its favour were so good that
every one at once saluted the inventor as the future "richest commoner
of England;" but a few analyses of the iron obtained soon pointed out
the presence of the old enemies to the perfection of iron-viz., phos-
phorus and sulphur; and after this fact was known, the process was as
unfairly depreciated as it had been formerly overrated; people will not
include the element time in their calculation, and remember that the best
invented processes may still be improved.
Bessemer's process no doubt will, in time, effect great improvements
in the iron manufacture, and the author, in common with many others,
has ever been a firm believer in its ultimate success, because the principle
is good; at least, so far as the removal of the excess of carbon and
silicon is concerned; and the very success of this part of the process is
suggestive of others, by which the sulphur and phosphorus might be re-
moved. What can be more simple than forcing air through a vessel
lined with fireclay and filled with molten iron, and producing a most in-
tense heat by the actual combustion of the carbon contained in all cast
iron to the extent of nearly five per cent.? This operation is effected in
an apparatus such as that depicted in the next cut, Fig. 205.
Mr. Bessemer's apparatus may be described as a clay crucible, or iron
vessel lined with fire-clay, and pierced with holes, or fire-clay tuyères,
beneath the surface of the molten metal, through which holes hot or
cold air is forced at such a pressure as to hold the melted iron sus-
pended in it, or to force it away from the air-passages; the air so forced
in gradually increases the heat of the metal, and forces up the slag or
cinder in a scum, which bursts and overflows like an exploding volcano,
till the heat, having gradually burnt and purged away the carbon, oxygen,
and silicon, leaves the iron malleable, though, by reason of its great heat,
still fluid, and when run out into a mould and set, convertible into forged
or bar iron without further process.
Up to this period the make of iron was a "puddling" process, and
the distinctive appellations henceforth of those before the era and after
will be "puddlers" and "non-puddlers," the stagnant and the flowing.
C
the
"A practical ironman," writing on the subject of Bessemer's process,
says, "There are two processes by which pig iron is converted into mal-
leable. In one process the pig is first converted into refined metal,
and the refined metal is puddled, and by the refining and puddling com-
bined, the pig is converted into malleable iron. In the other process,
pig iron (without being refined) is converted into malleable by what is
technically termed boiling,' which is, in fact, very similar to puddling.
After being treated in one of these ways, the puddler forms the iron
(which is then in the puddling or boiling furnace, of a pasty consistency)
into masses termed 'balls,' of about eighty pounds each; and these, taken
from the puddling or boiling furnace, are delivered to the shingler,'
who shapes them into 'blooms' by passing them under the forge
hammer or squeezer. The blooms are then passed through the rolls.
First the roughing and then the finishing puddle bar rolls, and a finished
puddle bar of malleable iron is produced. To convert the puddle-bar
364
IRON.
iron into merchant iron it is cut into lengths, which are piled together
and heated in a reverberatory furnace, and then rolled into the kind of
iron required.
Mr. Bessemer's process supersedes the refining and puddling or
boiling processes now used, but not, of course, the use of the hammer
B


AMWANANY
MMVAVAWANVAUN
SIITA
Dimens
AVMIVA
C

Fig. 205. A, B, c. Sections of Bessemer's apparatus, showing the construction of the iron
vessel lined with fire-clay, and the arrangement of the tuyères.
or squeezer and rolls. Mr. Bessemer's 'ingots' are in precisely the
same condition (except that they are much freer from impurities) as the
balls' above referred to when delivered to the shingler. Both the
'balls' and Bessemer's ingots are malleable iron, but without the fibre
or grain required for merchant purposes. This is produced by the ham-
mering or squeezing and rolling through which both the 'ball' and the
ingot have to pass. That Bessemer's process must succeed is at once
evident to any one practically acquainted with ironmaking, as the
rationale of the puddling or boiling process is to get rid of the excess of
BESSEMER'S PROCESS.
365
carbon and the impurities in the pig iron, by exposing every part of it, in a
melted state, to the action of the atmosphere. To effect this, the 'puddler'
with great labour works it about with an iron bar while it is in the
puddling and boiling furnace until every portion of it has been suffi-
ciently exposed to the atmosphere, the oxygen of which combines with
carbon in the iron and the other impurities, and carries them off. From this
description of puddling it will at once be seen that Bessemer's process
is, in fact, puddling upon a superior plan, as it is obvious that the iron
in Bessemer's process is far more effectually acted upon and purified by
the columns of air permeating every part, than by the imperfect mode
of exposing each portion of the liquid iron to atmospheric influence by
the tedious process of moving it about with an iron bar. The statement
in a Birmingham paper that a particular bar, rolled from one of Bes-
semer's ingots, was 'red-short,' proves nothing one way or the other, as
a great deal of iron made under the old process is red-short.' 'Red-
shortness' depends upon the quality of the ore from which the iron is
smelted, and cannot be remedied by any known process, unless, indeed,
Bessemer should effect it. Calcareous and siliceous ores commonly give
the iron produced from them a 'red-short' quality.
The magnitude and importance of this discovery of Mr. Bessemer
can scarcely be exaggerated. The only paralled to it is to be found in
the kindred inventions of Henry Cort, which, towards the close of the
last century, relieved this country to a great extent from its commercial
servitude to Russia and Sweden in regard to its supply of wrought iron.
Two years have been spent by Mr. Bessemer in the perfection of his
scheme; and when, the other day, he divulged it to the world before
men distinguished for their scientific attainments, and practical manu-
facturers well able to appreciate its vast public significance and its
whole bearing on the trade in which they are interested, it took them
wholly by surprise, superseding, as it does, the expensive, laborious, and
tedious processes now in use in the production, and the application in
some cases, of malleable iron and steel in this and many other countries,
cheapening those articles to an extent which will lead to their employ-
ment, and especially steel, for purposes to which they have never yet
been subservient, and in many respects refining and improving the quality
of the metal. Men like the two Rennies, Nasmyth, and others of minor
note, but of great experience as engineers and iron manufacturers, have
pronounced emphatically and without qualification in its favour; while
some, including Nasmyth, declare themselves unable to foresee the
whole of the advantageous results calculated to spring from its dis-
covery, not to this country alone, but wherever else it may be brought
It is to the credit of the Emperor of the French that, when
the invention, then in an imperfect state, was brought under his notice
within the last year, and when he comprehended its full import from
personal interviews which he graciously conceded to Mr. Bessemer, he
afforded him great facilities for conducting his experiments to a success-
ful result, and has since intimated his intention of bringing the plan into
practical operation in the arsenal at Rouelle.
into use.
366
IRON.
"The essential feature of Mr. Bessemer's invention is, that he takes
crude iron directly from the ordinary blast furnace, and in the incre-
dibly short space of thirty minutes converts it into ingots of malleable
iron or steel of any size, and fit for the various manipulations ordinarily
employed to adapt them to all the material purposes to which they are
now applied. He thus dispenses with all the intermediate processes
to which recourse has been had to produce the same effect within the
last seventy years, including the making iron into pigs, and the re-
fining, puddling and squeezing stages, with all their attendant labour
and fuel. Paradoxical as it may seem, it is not,
less true, that he
has achieved this great result by the application to the iron, in its
transition from the blast furnace to the condition of the ingot, of a heat
inconceivably intense, generated without furnace or fuel, and simply
by blasts of cold air. By this means he not only avoids the injurious
action of mineral fuel on the iron under operation, which has always
deteriorated the quality of English iron, but saves all the expense of the
fuel. He sets out with the assumption that crude iron contains about
five per cent. of carbon; that carbon cannot exist at a white heat in the
presence of oxygen without uniting therewith and producing combus-
tion; that such combustion would proceed with a rapidity dependent on
the amount of surface of carbon exposed; and, lastly, that the tempera-
ture which the metal would acquire would be also dependent on the
rapidity with which the oxygen and carbon were made to combine, and
consequently that it was only necessary to bring the oxygen and carbon
together in such a manner that a vast surface should be exposed to their
mutual action, in order to produce a temperature hitherto unattainable
in our largest furnaces. With a view of testing practically this theory,
he has constructed a cylindrical vessel of three feet in diameter and
five feet in height, somewhat like an ordinary cupola furnace, the in-
terior of which is lined with fire bricks, and at about two inches from
the bottom of it he inserted five tuyère pipes, the nozzles of which are
formed of well-burnt fireclay, the orifice of each tuyère being about
three-eighths of an inch in diameter. At one side of the vessel, about
half-way up from the bottom, there is a hole made for running in the
crude metal, and on the opposite side there is a tap-hole stopped with
loam, by which the iron is run out at the end of the process. A vessel
is placed so near to the discharge hole of the blast furnace as to allow
the iron to flow along a gutter into it, and a small blast cylinder is
used capable of compressing air to about 81b. or 10lb. to the square inch.
A communication having been made between it and the tuyères, the con-
verting vessel is in a condition to commence work. The blast being
turned on, and the fluid iron run into the vessel, a rapid boiling up of
the metal is heard going on within the vessel, the metal being tossed
violently about and dashed from side to side, shaking the vessel, by the
force with which it moves, from the throat of the converting vessel.
This continues for about fifteen or twenty minutes, during which the
oxygen in the atmospheric air combines with the carbon contained in
the iron, producing carbonic-acid gas, and at the same time evolving a

BESSEMER'S PROCESS.
367
powerful heat. The rapid union of carbon and oxygen adds still further
to the temperature of the metal, while the diminished quantity of carbon
present allows a part of the oxygen to combine with the iron, which un-
dergoes combustion and is converted into an oxide. At the excessive
temperature that the metal has now acquired, the oxide, as soon as
formed, undergoes fusion, and forms a powerful solvent of those earthy
bases that are associated with the iron. The violent ebullition going
on mixes most intimately the scoria and metal, every part of which is
thus brought in contact with the fluid oxide, which washes and cleanses
the metal most thoroughly from the silica and other earthy bases that
are combined with the crude iron, while the sulphur and other volatile
matters which cling so tenaciously to iron at ordinary temperatures are
driven off, the sulphur combining with the oxygen and forming sul-
phurous acid gas.
Fig. 206. Mr. Bessemer's Experiments at Baxter House.
"In conducting the demonstration of Bessemer's process, 6 cwt.
3qr. 181b. of molten iron from a furnace were poured into the fire-brick
vessel already described at twelve minutes past one o'clock, the blast
having been applied at a pressure of about 8lb. per square inch, and
continued until twenty-seven minutes past one. The mass of metal
368
IRON.
began to boil up, and the cinders and other impurities were extruded
from the top of the vessel by two apertures provided for the purpose.
Showers of brilliant sparks were thrown off during this process, which
lasted several minutes; and as the object was to produce a mass of
east steel, rather than continue the process to the extent necessary for
making pure iron free from carbon, the vessel was tapped at thirty-
six minutes past one o'clock, and the contents drawn off. Small speci-
men ingots being first taken, the general mass was run into an inge
niously contrived mould concealed in the floor in front of the apparatus,
and, after remaining there a few minutes, cooling down, it was raised
out of the mould in a red-hot state by an hydraulic ram, and placed upon
a weighing machine. The ingot thus produced, with the two specimen
ingots, weighed 6 cwt. Without the aid of fuel this mass of material
was converted in twenty-four minutes from crude cast iron as it comes
from the blast furnace into steel of fine quality.
"The experiment was unanimously pronounced by the company to
be perfectly satisfactory. It is a peculiar and important feature in the
process that by continuing the boiling a few minutes longer the whole
of the carbon still remaining in the mass of metal, and which gives to it
the character known as steel, would have been burnt off, and a pure
spongy mass of crystalline iron would have been the result.
"Mr. Bessemer states that hitherto the finest qualities of iron have
always been imported from Sweden and Russia, and these are now sold
in this country at from 207. to 30l. a ton; but by the new process iron can
be manufactured of equal quality at a cost of 27. per ton less than the
present cost of common English iron. If this statement be borne out
by experience of his invention, we shall no longer be dependent on the
foreign market for the production of iron of the finest quality. He also
speaks with something like enthusiasm of the extent to which what he
calls semi-steel, of a quality between malleable iron and steel in ordinary
use, as manufactured under his patent, may be expected to supersede
in time the use of malleable iron for railway plates and many other pur-
poses to which the latter is not altogether adapted; and he as confi-
dently asserts that the process of forging and welding, which, under the
existing system, is necessary whenever a piece of iron-work of a larger
size than from 80lb. to 100lb. is required to be constructed, will be dis-
pensed with. He looks, also, to the universal use of his discovery,
seeing that atmospheric air is the prime element used in producing the
desired result; it is not, therefore, dependent upon any local circum-
stances."-Times.
Such were the favourable anticipations formed by some practical and
scientific men of Bessemer's process, and it is perhaps to be regretted
that the invention was brought out too soon; a delay of one or two
years would have indicated the difficulties of the process, although it
must be remembered that the cost of experiments with iron on anything
like a large scale is enormous, and therefore the patentee had only one
of two courses open; either to keep what he had discovered a secret,
and therefore useless to mankind, or boldly to make his invention public :
THE PROPERTIES OF IRON.
369
the latter alternative was taken, and the theory advanced at the British
Association, Cheltenham, in August, 1856; and the experiments in
London demonstrated first, that crude pig iron could be wholly decar-
bonized, while still retaining the fluid state; secondly, that by the
injection of atmospheric air into the fluid metal, the combustion thereby
produced would, in the absence of fuel, raise the temperature of the
metal to a degree never before attained in the metallurgical operation;
and, thirdly, that the iron so decarbonized, without the employment of
fuel, would retain its fluidity long enough to enable it to be cast into
ingots capable of extension under the hammer or the rolls.
Pure iron has a specific gravity that is variously stated to be between
7·7 and 7·843 and 79. Iron which is not chemically pure, but is still
capable of being employed for useful purposes, presents various fractional
differences in the important property of specific gravity, as may be ob-
served in the following table:
No. 1. Black cast iron
دو
•
2. Mottled cast iron
3. White cast iron
""
دو
4. Grey cast iron
5. Hammered bar iron
>>
Specific gravity.
6.901 to 6.836
7.068
7.684
6.79 to 7.05
7.9
Iron may be brought to a high polish and brilliancy, but it presents,
under ordinary circumstances, a greyish colour. The hardness of this
metal constitutes one of its most valuable properties, and when united
with carbon, and possibly nitrogen, it furnishes that most valuable mo-
dification of iron called steel, of which more will be said hereafter. Iron
is not only very malleable, so that iron books with leaves as thin as paper
have been made of it, but it is also astonishingly ductile, and may be
drawn into wire as thin as hair. The most useful quality of iron is its
superior tenacity or power of resisting a strain; no other metal is equal
to it in that respect; hence the value of iron in the manufacture of
wire, standing rigging, traction ropes, cables, anchors, and warlike im-
plements, such as cannon and mortars. When iron is drawn out into
wire, its strength is said to be 13 times greater than that of hammered
iron, and its enormous tenacity may be appreciated by Rennie's expe-
riments, who proved that an iron wire 0.078 of an inch in diameter, is
capable of supporting 449 34 lbs. avoirdupois. The question of burst-
ing and breaking cylindrical or other shaped vessels of iron, such as
guns and boilers, has received an impartial elucidation from the expe-
riments of Nairn, who has ascertained that iron begins to change its
shape and elongate, when subject to a force equal to 66 per cent. of
the power capable of bursting it. The limit of the strength of iron
seems to have been reached in Mallet's mammoth 36-inch mortar, which
might be called Lord Palmerston's Pacificator. The experiments with
this terrific piece of ordnance (shown in frontispiece) have not as yet been
successful, partly because it does not project the shell so far as an ordinary
13-inch mortar, and secondly, because the rings of iron or portions of the
BB
370
IRON.
strengthening system have given way after one or two discharges; but of
its power there can be no doubt, when it is remembered that the shell
weighs about twenty-five hundredweight, or rather more than one ton and
a quarter. The momentum of such a falling mass must be enormous, and
no existing fortifications could withstand for any number of hours the
steady application of these shells.
Many years ago the late Professor Barlow ascertained that there is a
point beyond which any increase of thickness in a gun or mortar gives
no increase of strength. In his treatise on the "Strength of Materials
(1837) he states, speaking of hydrostatic presses,-
"It would at first sight appear that the strength of a cylinder exposed
to an internal pressure must be proportioned to its thickness; but prac-
tically this is not the case, it being found necessary to increase the
thickness in a much higher proportion than in that of the strain.'
He then enters into an investigation of the subject, and deduces the
following formula :-
pr
x=
c - P
x
in which required thickness of cylinder;
pinternal pressure per square inch;
~= internal radius of cylinder;
c = direct cohesive power of the material of which the cylinder
is made;
and he points attention to the fact that "it is obvious from this expres-
sion that no thickness will be sufficient to resist an internal pressure
which exceeds (per square inch) the cohesive power of a square inch
rod of the metal-a result which at first sight appears to be paradoxical;
but it will be observed that with such a pressure the interior surface
will be fractured before the other parts of the metal are brought into
action."
We cannot, then, be surprised, when we read of the partial failure of
Mallet's mortar, if we recollect Barlow's law, and also that the initial
force of gunpowder, according to Hutton, amounts to two thousand
atmospheres, or about thirteen tons pressure per square inch. Even
failures are instructive, and, therefore, one of the accounts from the
Times of the trial of Mallet's mortar is inserted here.
kr
Another trial of the 36-inch mortar was made in Woolwich Marsh.
The experiments commenced at 11 o'clock and terminated at 1.30, with
a charge of 50 lbs. of powder, &c., which obtained a range, as on the
former occasions, of about 340 yards to each 10 lbs. of powder. A
minute examination of the wedges, keys, rings, &c., having been made
and pronounced 'all right,' a second charge of 60 lbs. of powder, &c.,
was introduced. The second round, like the first, was highly success-
ful, the range in this instance exceeding 2000 yards, the shell alighting
beyond the butt, in a ditch which separates the marsh from the adjoining
property, and creating a tremendous eruption of water, black earth, &c.
MALLET'S MORTAR.
371
According to the prescribed arrangement of adding 10 lbs. of powder
to each successive charge, the third round contained 70 lbs., and al-
though the monster gun had stood the first two rounds well, an ad-
ditional degree of caution was observed by every one present to stand clear
of its proximity the instant the match was ignited. The effect of the third
round was less successful, as one of the steel cotters broke asunder,
and was rendered useless; but as the former experiments had shown the
necessity of being provided against a similar casualty, the broken key
was replaced, with some slight delay, by a second, wrought of malleable
cast iron, supposed to be more durable. The mortar was then reloaded
with an 80-lb. charge, and fired with apparent success, the shell again
mounting high in the air and taking a flight over 2758 yards, consider-
ably exceeding a mile and a half. The elevation of the mortar was fre-
quently varied, and was ultimately reduced from 48° 30′ to 45°. At
this stage of the proceedings it was found impossible to carry on the
experiments, as one of the main stays intended to secure the various
segments constituting the barrel of the mortar was broken, and one of
the principal wedges or cotters, a foot and a half in length, had escaped.
The bugles were then sounded, and Lieutenant Walton and the detach-
ment of mounted orderlies and sentries under his command in charge of
the range were called in and marched off the ground, and a committee
was formed to consult on the expediency and practicability of a con-
tinuation of the trial on some future occasion."-July 26.
The whole subject of iron is completely of a practical nature, and the
information respecting it is so entirely derived from gentlemen who
have made this metal their study, that we feel no hesitation in giving here
some of the results of the experience of Mr. Richard Solly, of the Lea-
brook Iron Works, Staffordshire, and of Sheffield. That gentleman
remarks that, although bar iron is commonly divided, by persons un-
acquainted with its varieties, into two great classes, namely, good iron
and bad iron, yet these terms can only be correctly interpreted to mean
that a certain iron is suitable or unsuitable for the purpose to which it is
applied, for I am not aware that there is any iron manufactured to be equally
suitable for all purposes, nor that there is any so worthless as to be suitable
for none. Some iron may be tough and able to bear great longitudinal
strain; such iron is peculiarly fit for chains and chain cables, but unless
it will weld easily, without requiring such a heat as to injure the tenacity,
the links will be liable to break where the welding exists. Other iron
may be strong to resist impact, or sharp blows, and stiff-such would
make good axletrees: but unless it will turn well, free from asperities
and black specks, termed greys, it is not approved. These greys are,
in reality, very minute cavities; their perfect absence it is very difficult
to attain; when attained, the iron is termed perfectly clear, and fetches
a high price. If hard, it will be in request for all articles where a high
polish combined with stiffness and strength is required; if soft, for
objects requiring tenacity."
Iron, soft and extremely tenacious, by which Mr. Solly means that
which will bear much bending backwards and forwards, and a great
BB 2
372
IRON.
strain, without breaking, is also much esteemed for peculiar purposes,
such as for the harpoons used in the capture of whales.
Independent of the quality of the iron, after it has been fabricated
into the article to be used, it is highly important that it should bear the
fabrication into such article with as little liability as possible to be
spoiled in the process. A smith will say that such and such iron is cold-
short or red-short, or that it is unsound, or that it will not weld, or that
it will not punch, or that it is full of dirt, or that, if drawn to a point, it
becomes brittle. Mr. Solly explains these defects still further: "When
a smith puts a piece of bar iron into his smithy fire, he frequently heats
it to a white heat, and then begins fashioning the article he is making; as
he continues hammering, punching, and bending the iron, it assumes by
degrees a yellow, and then a red heat. If the iron be red-short, the
moment it turns red, if the smith attempt to punch or bend it, the iron
cracks, and his work is spoiled. Therefore, in working red-short iron,
he is obliged to watch the colour carefully and to suspend his work
before it turns red, and to put it in the fire to re-heat it. This occasions
a loss of time and greater consumption of fuel, and consequently in-
creases the expense of manufacture. The usual mode of trying whether
iron be red-short is by what is called the ram's head. If this can be
done at one heat, that is, without replacing the bar in the fire, it is con-
cluded that it is not red-short. Cold-short iron usually works well at all
heats, and is not liable to crack when under the smith's operations; but
when cold it will not bend far without snapping short with a granular
appearance, the grain, or crystal, being much larger than in some of the
best descriptions of iron, which may be granular, but the grains are fine
and the colour silvery. Good common irons, and those of best quality
for any but special purposes, when nicked on one side and broken by
the succesive blows of a hammer, draw out and exhibit a fibrous texture
similar to that of an ash stick when broken. Iron for turning purposes
is mostly made from scrap, in order to get it as clean as possible, and
at the same time free from the seams common in piled iron. The
softest and almost the cleanest iron for turning for cotton and other
machinery is made from wrought iron swarf (or turnings). Sometimes
the swarf is worked by itself, but commonly a ball is made of good
swarf, and while hot, fine swarf is thrown into the furnace, and the ball
is rolled about so that the swarf adheres to it, and it is then taken to
the hammer. Piston rods, and other important parts of machinery, are
made from faggots of iron bars drawn under a swage hammer, and fre-
quently are twisted, in order to prevent the fibres and seams of the iron
from running in the direction of its length, and also to make it more
regular in its wear.
"
In a paper read by Mr. Solly before the British Association, "On
Molecular Changes in the Constitution of Wrought Iron," that gentle-
man was the first to point out that "an extraordinary change is pro-
duced in iron by long-continued vibrations, or shocks, or blows of a
hammer. It appears to take place more readily in scrap iron than in
other kinds, and especially if there are many filiets, or collars, or other
inequalities, these appearing to destroy the uniformity of the vibrations,
SOLLY'S OBSERVATIONS ON IRON.
373
and so assist in inducing a re-arrangement of the molecules. If a shaft
or bar be swaged, i.e., gently hammered from a yellow heat until it
becomes lukewarm, or turned at the end, either larger or smaller than
the other part of the bar, and it be struck at the opposite end with a
hammer, the probability is that the former part will fly off after a very
few blows have been struck, unless it be held in the hand, or unless the
increase or decrease be very gradual. By plunging iron when red-hot
frequently into water, the fibres will also lose their form and become
quite crystalline, and as brittle as cast-iron. If two pieces of wrought
iron work together without lubrication, a kind of union takes place
between some of the particles, and the surfaces of the two pieces of iron
are torn and galled in a surprising manner. This is termed by mechanics
'seizing,' and is a source of great annoyance to them, as it will some-
times.happen while fitting portions of machinery together."
Mr. Samuel Poole states that he has seen a cross-head seized on the
end of a piston rod, so that it was utterly impossible to move it, except
by an hydraulic press, or some other powerful means. This fact reminds
us of the result that may be obtained by bringing two pieces of ice
together whilst submerged in water at a temperature of 32° Fah., the
two surfaces immediately adhere and freeze together, called by Dr.
Faraday (who has investigated the subject with his usual penetration)
regelation. From these experiments, coupled with the remarkable
cohesion that takes place sometimes between surfaces of plate-glass,
Mr. E. W. Brayley has endeavoured to deduce a general law or the
universality of a principle analogous to regelation.
Mr. Solly again observes that "it is remarkable that most red-short
irons are tough when cold. This is the peculiar property of the Welsh
iron in general, but there are some both red-short and cold-short. The
best South Staffordshire irons are neither cold-short nor red-short. The
defect of red-shortness is generally attributed to the presence of sulphur;
cold-shortness, to phosphorus; and difficulty in welding, to arsenic. I
have some reason to believe that the addition of flue cinder in the pud-
dling furnace tends to counteract red-shortness. With respect to other
of the defects to which I have alluded, we can explain some by the
process of manufacture; some we can only guess at; and of the causes
of some we are quite ignorant. Two conclusions alone appear to be
undisputed, namely, that extremely small quantities of extraneous sub-
stances in chemical combination with iron produce most striking altera-
tions in its quality, although such quantities of extraneous substances
may be so minute as almost to clude the analysis of the scientific
chemist; also, that many of the qualities of iron depend on the par-
ticular arrangement of its molecular particles, which may be influenced
and altered by merely mechanical operations."
Mr. Solly then proceeds to define other peculiarities and properties.
belonging to iron, called body, clearness, soundness, toughness, hardness,
and softness.
Body is the property that iron possesses of bearing the considerable
and repeated action of the fire without becoming brittle.
374
IRON.
Clearness is the absence of greys or small cavities in the iron.
Soundness is freedom from a coating of protoxide of iron, which is an
obstacle to perfect welding.
Toughness depends on the molecular arrangement of the particles.
Sulphur is said to contribute to the fibrous, and phosphorus to the
crystalline state.
Hardness seems to depend on the condition of the carbon, whether
combined or uncombined.
Softness appears to be the result of the purity of the iron; that of
Biscay being the softest and purest.
Mr. Thorneycroft has likewise shown that compression, or impact.
upon the end of a bar of iron, will alter its texture from a fibrous to a
granular character; and he states that this is well exemplified by two
tools used by forgemen. The first is called the "gag," which is a
short bar of iron of about two inches diameter, employed for holding
up the end of the large helve during the intervals of working; it is sub-
jected to impact endways, whenever the lower end is placed on the
anvil, and the other receives a vertical blow from the helve falling about
an inch upon it. However fibrous may be the quality of iron used for
making the "gag," it soon becomes brittle, and literally falls to pieces
as if it were made of cast-iron.
The second instance is that of the tool employed in puddling, one end
of which is constantly subject to blows from a small hammer, in order
to detach the metal which adheres to the other extremity. After being
some time in use, it frequently breaks at a slight blow, exhibiting a per-
fectly granular fracture. If a bar of fibrous iron be bent down at a
short angle, the fibres of one side are compressed, and those of the other

B

A
Fig. 207. A. Granular fracture of iron. D. Fibrous fracture of iron.
MOLECULAR CHANGE IN IRON.
375
side elongated, and after being bent back again, the fracture on the com-
pressed side will exhibit a granular appearance, having evidently lost
the fibre and been broken off short, as at Fig. 207, ▲ and в.
One of the greatest sources of mischief to the internal molecular
structure of a bar of iron is the cold swaging or hammering which is
given to the iron in order to give it a nice appearance. Mr. Nasmyth
subjected two pieces of cable bolt iron to one hundred and sixty blows
between swages, and afterwards annealed one of the pieces for a few
hours. The unannealed piece broke with five or six blows of a hammer,
showing a crystallized fracture, while the annealed piece was bent double
under a great number of blows, and exhibited a fine fibrous texture;
thus showing that the fibrous texture could be restored apparently by
readjusting the combined or latent heat of the iron. Mr. Gravatt men-
tions a case at the Thames Tunnel, where the "fleeting bars" used as
levers for turning the large screws for forcing forward the shield never
lasted longer than three or four weeks, although they were very strong,
and were made from the best materials by careful smiths. They were
only used occasionally, and then without any concussion, having only
the power of eight men exerted upon them; yet they broke constantly,
and the fracture exhibited a bright crystallized appearance. It was
found at last that, in order to give them duration, they should be left
rough, and not hammered much in working.
In wrought-iron guns it might be expected that the repeated concus-
sion arising from the discharge of the gunpowder would gradually bring
about a change in the molecular structure of the iron; but this does not
appear to be the case, and may be due to the great heat evolved by the
combustion of the gunpowder, readjusting the balance of the latent heat
of the forged iron, which might otherwise be disturbed, and produce the
granular and brittle state. The whole phenomena represent, perhaps,
the most curious properties belonging to the metal iron, and deserve
still further investigation.
Returning again to the question of the impact or blow that iron is
capable of sustaining, it is evident that the quality of cast iron is ex-
tremely variable, and consequently the greatest care must be used in
selecting the very best iron for the manufacture of cannon; and even
with the utmost caution accidents arise similar to that most unfortunate
one recorded last August, which occurred with the volunteer artillery at
Dover Castle, when a large piece of ordnance suddenly burst and killed
several gentlemen. The use of a tougher iron therefore becomes de-
sirable, and the discovery of the wrought-iron gun of Sir William Arm-
strong seems just to have been made at the right moment, when wars
and rumours of wars compel the most peacefully-disposed nations to
arise in self-defence. Consequently the British nation hailed with plea-
sure the account given of the new wrought-iron gun, by the then
Mr., and now Sir William Armstrong, in the Times of the 3rd of January,
1857, and headed "Experiments in Gunnery." The learned civilian
engineer says—
"In the latter part of 1854 I submitted to the Duke of Newcastle,
376
IRON.
then Minister at War, a proposal for a gun which I anticipated would
possess great superiority over the common forms of light artillery, and
I undertook, with his Grace's authority, to construct a field-piece in con-
formity with the plan I had suggested. The gun was accordingly soon
afterwards made, and has since, during a period of nearly two years, been
the subject of numerous experiments, partly upon the Ordnance firing-
ground at Shoeburyness, but principally under my own direction in this
neighbourhood.
“I have hitherto avoided publicity in reference to these experiments,
but, as matured results of much interest and importance have now been
arrived at, and as other names are already before the public in con-
nexion with gun experiments made during the same period, I feel that
I may now, without impropriety, give some information on the subject.
With a view to strength and durability, the gun is composed in-
ternally of steel and externally of wrought-iron, applied in a twisted or
spiral form, as in a musket or fowling-piece. The bore is nearly two
inches in diameter, and is rifled. The projectile is a pointed cylinder
six inches and a half long, and its weight is five pounds. It is made
of cast iron, coated with lead, and is fired from the gun with a charge
of ten ounces of powder; it contains a small cavity in the centre, and
may be used either as a shot or a shell. When applied as a shell the
cavity is filled with powder, and a detonating fuse is inserted in front,
so as to fire the powder in the centre on striking an object. When used
as a shot the powder is omitted, and an iron point, which favours
penetration, is substituted for the fuse. The gun is constructed to load
at the breech, the object being not only to obviate the disadvantages of
sponging and loading from the front, but also to allow the projectile to
be larger in diameter than would enter at the muzzle, and thus to insure
its taking the impress of the grooves and completely filling the bore.
The piece weighs 5 cwt., and is mounted upon a carriage which bears
a general resemblance to that of an ordinary 6-pounder field-gun, but
which embraces a pivot frame and recoil slide. A screw is also applied,
not only for elevating and depressing the gun, but also for moving it
horizontally, by which means great delicacy of aim is effected. The recoil
slide has an upward inclination, which enables the gun, after running
back, to recover its position by gravity, and its use is to relieve the
pivot-frame and adjusting screws from injurious concussion.
"I shall now give some particulars of the experiments recently
made with this gun on the coast of Northumberland, near the village
of Whitley, under the official inspection of Colonel Wilmot.
2
Fourteen shots were in the first instance fired from a distance of
1500 yards at a timber butt, 5 feet wide and 7 feet high. Six of these
were expended in finding the elevation proper for the distance, but after
that was determined, every succeeding shot hit the object without pre-
vious graze. The final elevation of the gun was 4 degrees 26 minutes,
and the mean lateral distance of the shot marked from a vertical line
through the centre of the butt was only 11 inches.
Persons who are conversant with artillery practice will be able to
THE ARMSTRONG GUN.
377
appreciate the accuracy of this firing, but for the information of those
who are unacquainted with the subject, I may state that the ordinary
6-pounder field-piece, which in point of weight forms the nearest ap-
proach to the present gun, is perfectly useless at a distance of 1500
yards, and is very uncertain even at 1000. It is only, therefore, with
heavy artillery that a comparison can be drawn, and it will be sufficient
to state that in tabulating the practice made with such ordnance the
deflections are invariably recorded in yards, whereas with this rifled gun
they can only be properly given in inches.
"With respect to penetration, the following particulars will be regarded
as equally remarkable, considering the small weight of the shot and
the length of the range. The butt was three feet thick, and was com-
posed of six layers of rock elm bolted together, so as to form a solid
block. One shot passed entirely through, another struck near the edge
and glanced, and the remaining six penetrated within a few inches of
the opposite side.
rr
Shell firing was next tried at a distance of 1500 yards, the gun being
fired at the same elevation and with the same charge as in the previous
practice at the butt.
"In this case two targets were erected, one behind the other, so as to
appear as one object when viewed from the gun, and a space of thirty
feet was left between them. The front target was intended to exhibit
the perforations of the shells before bursting, and the back one to show
the effect of the fragments resulting from explosion.
"After some preliminary experiments, twenty-two shells were fired at
the front target, and of these only one missed the object of aim. The
following are the particulars: Seventeen hit the first target direct, and
burst behind it, the fragments penetrating the second one; three grazed
and burst immediately in front of the first target, and perforated both
with the pieces; one hit the bottom of the first target and exploded in
the ground, and the remaining one missed entirely and burst on some
rocks nearly in line beyond. A strong side wind was blowing at the
time, and accounted for the deviation of this single shell.
"Four shells and three shot were then fired at an elevation of six
degrees, from a distance of 2000, or, more accurately, 1964 yards. All
these struck within the breadth of the target; but the elevation being
scarcely sufficient, they all fell a little short, except one shell, which,
ranging somewhat further than the others, hit the target and burst as
usual.
"The results of this shell firing were as follows: The front target
contained 51 holes, and the back one 164, while the ground between
and adjacent to the targets exhibited about 70 perforations by frag-
ments of shells, the greater portion of which were afterwards recovered
by digging.
With respect to ranges exceeding 2000 yards, I may state that on
previous occasions the gun had been tried up to 3000 yards-a distance
which was reached with an elevation of eleven degrees, and the usual
charge of ten ounces of powder, or one-eighth the weight of the pro-
378
IRON.
jectile. By augmenting the charge the range is increased, but the
accuracy is impaired, and I therefore adhere to the ten-ounce charge,
which gives ample penetration, as the experiments at the butt will
testify. I may also observe that the ranges obtained with this charge
bear a favourable comparison with those of the heaviest round-shot
guns fired with a much larger proportion of powder.
"It is a curious fact, and one which greatly increases the efficiency of
the shells, that, owing to the bursting charge requiring a minute space
of time to mature its ignition after the firing of the fuse by impact,
the shell is enabled to travel four or five feet after striking an object
before disruption takes place. Hence, therefore, it acts as a shot before
it bursts as a shell. When it perforates a target the explosion may be
seen to take place a few fect beyond, and when it grazes it has time to
rise, and may be observed to burst after clearing the ground. If,
therefore, it were fired against a ship, it would first penetrate the side
in its entirety, and then bursting, traverse the deck in fragments; or if
directed against troops, it would pierce the front line as a bullet, and
operate like grape shot beyond. The shells explode with equal cer-
tainty, whether the first substance struck be hard or soft, and, in fact,
they even burst on the surface of water, provided the elevation of the
gun be not too great. The bursting charge is very small, but it suffices
to break the shell into about thirty pieces, which pursue their forward
course without too much dispersion.
"It is impossible to contemplate the results obtained with this gun
without being impressed with the important part it is calculated to per-
form in warfare. Opposed to any ordinary field-piece, it would be like
the Minié rifle against the old musket, and no gun could be worked at
an embrasure if a fire of shells were directed against it by one of these
rifled pieces placed within the distance of a mile. In naval operations,
also, guns of this description, but of larger size, might apparently be
applied with great effect-more especially as a system of breech-loading,
combined with a self-recovering recoil action, would be peculiarly
advantageous in firing from portholes. Even light five-pounders send-
ing their shells from great distances through the sides of a ship, and
sweeping the decks with fragments of lead and iron, would produce
very destructive effects, and a small swift steamer carrying a few such
guns might prove a very troublesome opponent to a large ship of war.
But if the dimensions of the gun were increased so as to adapt it for
shells of 20 lb. or 30 lb., still more terrible injury could be inflicted at
greater distances, and the ponderous artillery now used at sea would be
of little service when opposed to the accurate and long-range firing of
such rifled shell-guns.
"It now only remains to be stated that in the course of the long
series of experiments made with this gun it has been fired nearly 1300
times without sustaining any permanent injury, either in the breech-
loading arrangement or otherwise. The only parts exposed to wear
(and none are seriously so) are separable from the gun, and can with
great facility be renewed."
THE ARMSTRONG AND WHITWORTH GUNS.
379
The sequel to this letter is too well known to require comment ex-
cept in praise of the Government, who have secured this valuable
invention and erected great works at Woolwich for the manufacture of
the Armstrong guns. Since the use of the wrought-iron gun, Mr.
Whitworth, the celebrated engineer, has brought forward his gun, called
the Whitworth gun, which bids fair to equal in the results obtainable

Fig. 208. Whitworth Gun.
from it those already ascertained to belong to the Armstrong weapon.
Considering the immense number of fortified places belonging to Great
Britain where the old cast guns must all eventually be replaced by
rifled cannon, it is not too much to anticipate that the work will be
divided between these two great engineers, and that for every “Arm-
strong" we shall have a Whitworth" gun. The old caution of
"not having too many eggs in one basket" may apply with peculiar
aptness to the manufacture of only one kind of ordnance; although, so
far as we know at present, the Armstrong gun is as near perfection as
a gun can be, and that the first letter written by Sir William Armstrong
on his new gun is not an exaggeration is proved by the results lately
obtained with a 100-pounder gun of this construction, and headed in
the Times of August, 1860, as the warlike case of "Armstrong v. Mar-
tello."
"The Martello tower at Eastbourne, selected as the object to be fired
at, was one which the sea was gradually undermining, and the guns em-
ployed were a 40-pounder of 31 cwt., an 80-pounder of 63 cwt., and a
short 100-pounder, weighing only 53 cwt. The distance was 1032
yards, and the projectiles employed were partly solid shot, and partly
percussion shells. The tower was built of very strong brickwork, the
thickness of the walls being 7 ft. 3 in. on the land side, and 9 ft. on the
side next the sea. It measured 48 ft. in diameter at the base, and was
upwards of 30 ft. high. Like all other Martello towers, it was arranged
380
IRON.
to carry one heavy gun en barbette. The roof or platform bearing this
gun consisted of a massive vault of great strength, supported by the
walls and by a solid pillar of brickwork occupying the centre of the
tower. The chief merit which has been claimed for Martello towers is
that, from their circular form, they deflect all shot which strike them in
the curve; but the accuracy of rifled guns has rendered this advantage
of small importance, while the exposed condition of the gun on the top
would render it entirely useless against arms of precision. The expe-
riments commenced by a few rounds of solid shot from the 40-pounder
and the 80-pounder, and of blind shells from the 100-pounder, the object
being to ascertain the penetration of these various projectiles. The
80-pounder shot was found to pass quite through the wall into the
tower, piercing 7 feet 3 inches of brickwork; the others lodged in the
wall at the depth of about 5 feet. Live shells were then fired, and
with so much effect that after eight or ten rounds from each gun the
interior of the tower became exposed to view. The firing was then
suspended to enable his Royal Highness the Commander-in-Chief, who
was present, to examine the breach, and also to allow of the execution
of a photograph. The fire was resumed in the evening, and continued
at intervals on the following day. The centre pillar supporting the
bomb-proof roof was speedily knocked away, but the structure was so
compact that the vault continued to stand, and was only brought down
by a succession of shells exploded in the brickwork. Nothing could

い
​Fig. 209. View of the Martello Tower after its Destruction by the Armstrong Guns.
ARMSTRONG V. MARTELLO.
381
exceed the precision with which these shells were thrown. The broken
section of the vault was itself but a small object to hit, but this was
done with such unerring certainty that the very spot selected was almost
invariably struck. The total number of shot and shell fired against the
tower was 170, of which only a small proportion was from the 100-
pounder. The ultimate result was that the land side of the tower was
completely destroyed, and the interior space filled with the débris of the
vaulted roof. The opposite side was also injured, but the mound of
fallen materials saved it from destruction. We may infer from these
valuable experiments that no species of masonry or brickwork penetrable
by percussion shells will in future be available in fortification. Nor is
it conceivable how wooden ships are to withstand the effects of such
projectiles. The 100-pounder gun used on this occasion is probably the
most formidable weapon ever yet produced. Its shell, which weighs
100 lbs., contains 8 lbs. of powder, and yet the weight of the gun with
which this tremendous projectile is discharged is less than that of the
ordinary 32-pounder, the weight of which is 56 cwt."
EXPERIMENTS WITH IRON.
First Series.
To obtain chemically pure iron, sesquioxide of iron, prepared by the
process described at p. 385, is placed in a hard green glass tube, one end
of which is drawn out to a capillary tube, and the other connected by
caoutchouc (not vulcanized india-rubber, because that substance contains
sulphur), with an apparatus for generating and making pure hydrogen
free from phosphorus, hydrocarbon vapour, arsenic, antimony, or
sulphur. The tube containing the pure sesquioxide of iron is moderately
heated, whilst the pure hydrogen passes through it, and the latter, com-
bining with the oxygen of the sesquioxide of iron, produces water,
which is driven out of the tube by the heat, and the iron remains in the
metallic state, but in a curious pyrophoric condition, so that when shaken
into the air it takes fire like pyrophoric lead, copper, or antimony, and
the property of burning spontaneously when brought in contact with
the air is said to be much increased by the addition of a little alumina
to the sesquioxide of iron. Another mode of obtaining pure iron is to
melt some of the finest Biscay iron from Spain in its own scales, with
some pure green glass free from lead, in a porcelain crucible placed in-
side a Hessian crucible, and exposed to the most intense heat of a wind
furnace.
If anything will try the heating power of a wind furnace, it is melting
pure iron, and the author recollects the gusto with which his old teacher,
Mr. John Thomas Cooper, used to relate the story of Dr. Wollaston
asking him if he had a wind furnace? On replying in the affirmative,
the doctor, intent upon a little quiet fun, put into his hands some horse-
shoe nails, and asked him to be good enough to melt them. Mr. Cooper
used to say, "By Jove! I melted them, but it was a tough job; and when
382
IRON.
I put the melted nails into Wollaston's hand, all he said was, 'Oh!'" The
Biscay iron contains only a little carbon, and this acted upon by the
oxygen in the iron scales is burnt away, whilst the excess dissolves in
the glass, forming a silicate of iron, and the metal itself is found at the
bottom of the crucible. The erection of a wind furnace and chimney
being somewhat expensive, it is extremely useful to know that for all
temperatures up to that of the melting point of cast iron, a most useful
patent blast gas furnace has been invented by the eminent philosophical
instrument maker, Mr. John Joseph Griffin, of Bunhill-row, Finsbury.
This furnace is intended for the fusion of refractory metals, and for
other purposes which demand a high temperature, producible with readi-
ness, and under complete control. The fuel is common coal gas, taken
at the ordinary pressure, and supplied with a blast of atmospheric air
by means of a blowing machine. The apparatus consists of an iron gas
burner, and a clay furnace packed
AIR
1
3
Fig. 210. The Gas Burner.
GAS
with small flints. The gas burner is
a cylindrical iron reservoir, con-
structed as shown in section in Fig.
210, which is drawn on a scale of
one-third the full size. It contains
two chambers, which are not in com-
munication with one another. Into
the upper chamber gas is allowed to
pass by the tube marked gas. Into
the lower chamber air is forced by
the tube marked air.
The upper
part of the burner is an inch thick
in the metal. Through this solid
roof holes are bored for the escape
of the gas. The air passes from the
lower chamber through a series of
metal tubes placed in the centre of the gas holes, and continued to
the surface of the burner, so that the gas and air do not mix until both
have left the gas burner, and then a current of air blows through the
middle of each jet of gas. The gas and air pipes generally used are
both half an inch in the bore, and about ten inches long; the gas has
usually had a pressure of half an inch of water, and the blast of air
about ten times that pressure. The quantity of gas used in an hour
is about one hundred cubic feet, when the gas burner contains six-
teen jets. The jet of blue flame produced by such a burner, when
the gas is lighted and the blast of air is set on, is about two inches
in diameter and three inches in length. It can be directed into the
furnace either at the top or the bottom. Fig. 211 represents a section of
a gas furnace heated by the top; a, is a gas burner, similar to Fig. 210;
6, is a support for the burner, to be used as represented in Fig. 212; d,
and d', are two plates of fire-clay, bored to fit the nozzle of the gas
burner; e, e, are two cylinders of fire-clay; c, is an iron support for the
furnace. Upon the base, d, is placed a perforated cylinder of fire-clay,
and upon that as many discs of fire-clay as bring the crucible that is to

GRIFFIN'S GAS-BLAST FURNACE.
383
be heated up to the top of the furnace. A perforated cylinder of plum-
bago is placed round the crucible, and the space between the middle

d
Ъ
a

C
С
9
e
f
a
C
C
12
6
Fig. 211. Section of Gas Furnace
with Gas Jet at the Top.
Fig. 212. Gas Furnace with Gas Jet
at the Bottom.
pile and the walls of the furnace is filled with flat stones, of about half
an inch diameter. The cover, d', is then to be put on, the gas is to be
lighted, the blower to be put into action, and the flame to be directed
down into the furnace. The whole force of the blue flame then acts
directly upon the crucible. The products of the combustion of the gas,
and the nitrogen and surplus air, escape at the bottom of the furnace,
leaving most of their heat with the pebbles, crucible, &c. Fig. 212 repre-
sents a gas furnace arranged for being heated at the bottom. The parts
marked a, b, c, d, e, e, have been already described; but the piece
marked f, g, g, and represented separately by Fig. 213, is a false bottom,

9
9
Fig. 213. False Bottom for Gas Furnace.
consisting of a fire-clay plate, mounted with a pair of iron handles.
The crucible to be heated is flanged at the mouth, Fig. 214, and rests by
the flange on a perforated cylinder of plumbago, Fig. 215. This cylinder
rests on the fire-clay plate, d, Fig. 212. Upon the false bottom, f, is placed
384
IRON.
a perforated dome or hemisphere of fire-clay or plumbago, and above the
dome the furnace is filled with small flints. The flame is put in at the


Fig. 214. Crucible to be heated.
Fig. 215. The Perforated Cylinder
of Plumbago.
bottom. When the crucible is to be examined, the whole upper part of the
furnace can be lifted by means of the handles, g, g (Fig. 213), and, if neces-
sary, can be easily replaced. The heat produced by this furnace is suffi-
cient for the fusion of silver, gold, copper, cast iron, wrought iron, nickel,
and cobalt. One pound of copper can be melted in ten minutes, three
pounds in fifteen minutes, ten pounds in an hour. Cast iron melts with
nearly equal facility."
The author has witnessed the most satisfactory results obtained with
this patent gas blast furnace, and cannot too highly recommend it to
practical chemists and amateurs. If the crucible containing the melted
cast iron is removed and poured from a moderate height on to a level
iron tray about three feet in diameter, a magnificent series of sparks
are thrown upwards as the iron burns in contact with the oxygen of
the air.
Second Series.
The equivalent of iron is 28, and it combines with oxygen in several
proportions, as follows:
Protoxide of iron.
Sesquioxide of iron
Ferric acid.
The mixture of the protoxide and sesquioxide
called magnetic oxide of iron
FeO
Fe,03
FeO3
Fe,04
If a solution of pure sulphate of iron free from dissolved air is
placed under a jar filled with hydrogen gas, and provided with a brass
cap and sliding rod to which is attached a test tube containing some
strong solution of potash, also free from dissolved air, no action of
course takes place until tne potash is thrust into the solution of iron,
when a white precipitate of the hydrated protoxide of iron (FeO,HO)
is obtained, which quickly changes to the green hydrated magnetic
oxide, and gradually to the red or sesquioxide of iron by exposure in
another jar containing oxygen gas or air. If the liquid containing the
hydrated oxide is boiled, it changes black, and is converted into the
state of anhydrous protoxide of iron (FeO), which, however, is always
more or less altered by the oxygen of the water, so that it is impos-
THE OXIDES OF IRON.
385
sible to obtain it absolutely pure. It is this oxide which is the base of
that important salt called green vitriol, or sulphate of iron, used so
extensively by dyers and calico printers, and likewise in the manufacture
of ink.
The sesquioxide of iron (FeO3) is always the condition in which iron
is estimated by analytical chemists, and is produced by boiling any of
the proto-salts with dilute nitric acid until no more orange-red fumes
escape. Thus, supposing iron is dissolved in hydrochloric acid, and
ammonia added in excess, the protoxide is certainly precipitated, but
very imperfectly, because it is soluble in ammonia. If, however,
the solution of chloride of iron is first boiled with an excess of nitric
acid, and a slight excess of ammonia added, a very bulky red precipi-
tate is formed, which is the hydrated sesquioxide of iron. This pre-
cipitate must then be collected, washed, dried, and ignited, and is the
sesquioxide of iron (FeO3).
C+
It has been shown by Mr. John Spiller, assistant in the chemical
establishment of the War Department, Woolwich,* that the sesquioxide
of iron, in common with many other bases, is disguised by the presence of
citric acid. A solution of the sesquichloride of iron is not precipitated
by ferrocyanide of potassium, benzoate, or succinate of ammonia; nor
is the coloured reaction produced with acetate of potassa, ferri-
cyanide, or sulphocyanide of potassium. The reaction between sesqui-
chloride of iron and ferrocyanide of potassium is curiously modified.
On mixing these two solutions in the presence of an alkaline citrate, a
yellow solution is formed, which becomes deep-blue in colour on largely
increasing the amount of ferrocyanide of potassium; no precipitate of
Prussian blue is produced until hydrochloric acid in excess is added.
Neither potassa nor ammonia will precipitate protoxide of iron in the
presence of citric acid.
The alkaline product so obtained, gives with
sulphide of ammonium, if dilute, a dark olive-green solution; but if
more concentrated, an immediate precipitate, with a supernatant liquid
of that colour. The sulphide of iron comes down, however, on boiling,
or on standing for a sufficient length of time in the cold. The proto-
phosphate of iron is held in solution, and the reaction between ferro-
cyanide of potassium and a protoxide of iron is entirely masked."
Ferric acid has never been isolated, and is only known in combination
with potash, soda, lime, baryta, &c. The magnetic oxide of iron is
interesting, not only because it occurs in nature as the loadstone,
and sometimes most perfectly crystallized in octohedra, but also on
account of the numerous simple processes by which it can be made.
Thus, if a bundle of very thin iron wire is attached to a bit of lighted
taper and plunged into a jar of oxygen gas, a most brilliant combustion
of the iron takes place, and if the gas jar is standing in an earthen dish,
the ignited magnetic oxide of iron falls through the water and melts
itself into the glaze; but if the jar is placed in a stout metal dish, the
surface of which is blackleaded, then the globules of black magnetic
* Quarterly Journal of the Chemical Society, July, 1957.
C C
386
IRON.
oxide of iron may be removed with greater facility, at the same time
exhibiting most perfectly that peculiar condition of heated matter by
which water is repelled, as it were, from the surface, and does not come
in contact with it until the temperature has sunk below the point that
will produce the spheroidal state.
During the combustion of steel or iron in oxygen a quantity of the
sesquioxide of iron is also produced in such a very fine state of division,
that it appears for the time to be quite vaporous, and does, indeed,
condense on the sides of the gas jar as a red powder. If steam is
passed over fine iron wire heated to redness in a gun-barrel, the magnetic
oxide is produced, which crystallizes in minute octohedra.
The hydrated magnetic oxide is not difficult to make, and is some-
what amusing on account of its following the course of a powerful
magnet, if the latter be held against the sides of the bottle containing
it. Divide a solution of sulphate of iron into three parts, boil two of
them with nitric acid to convert the iron into the sesquioxide, let it
cool, and then add the third, and pour the whole into a strong solution
of ammonia, taking care that the latter is in excess, and that the whole
is well stirred. The order of the process must be strictly attended to,
or it will fail to produce the true hydrated magnetic oxide.

Fig. 216. Magnet drawing up the Magnetic Oxide of Iron (contained in Water) at
the Side of the Bottle.
It is the oxide of iron which imparts the colour to bricks, and also
to many jewels and precious stones. The sapphire, the garnet, the
topaz, the amethyst, all contain oxide of iron, and the blue of the lapis-
lazuli has been imitated with great success by combining silica, oxide
of iron, &c., in a peculiar manner, as by the process lately conducted
by Messrs. Beard at the Wharf-road, City-basin. Both iron and steel are
oxidized in the most brilliant manner by mixing them in the divided state
of filings with gunpowder, sulphur, and charcoal. The firework is called
a gerb, and is termed iron or steel, according to the nature of the
filings used. The following proportions give fair results :-

។
EXPERIMENTS WITH IRON.
387
Meal
gunpowder.
16
3
Nitre. Charcoal. Sulphur.
8
Cast-iron
filings.
Steel
filings.
3
10
•
16
Iron gerb
Steel gerb. 16
These materials are mixed when required, and rammed into cases, because
the gerbs become useless if kept any length of time, in consequence of the
sulphur combining with the iron. The steel filings produce long needle-
shaped sparks, and the iron filings afford stars or rosettes, that burst
and break in the most beautiful manner as they fall to the ground.
The rapidity with which steel filings oxidize is well shown by making
a large flame with alcohol in a flat stout tin dish, and throwing into it a
mixture of gunpowder and steel filings. The latter burn with great
rapidity, whilst the former drops through the flame in large quantities
unburnt; and when the flame is extinguished, the alcohol poured off, and
the gunpowder dried, it may be fired on the application of a lighted
taper, proving that the flame did not ignite the powder as it passed
through the alcohol flame.
Third Series.
Chlorine, iodine, bromine, and fluorine unite with iron and form
salts, which are chiefly interesting to the scientific chemist and the
medical practitioner.
The combinations of sulphur with iron deserve notice in this work,
because the sulphide (FeS) is the chief source of sulphuretted hydrogen,
so frequently required in the chemist's laboratory. The sulphide of
iron is made by placing some common iron tenpenny nails in a crucible
provided with a cover, and heating them to a bright red heat; bits of
roll sulphur are then thrown in, and the lid of the crucible put on after
each portion of the sulphur is added. If the heat of the furnace is
kept up properly, and the sulphur added till the iron nails are fused
and nearly melted away, the sulphide of iron is formed, which may
be allowed to cool in the crucible, or may be poured out into a proper
conical mould, and when cold broken up and put into a dry, corked
bottle. The sulphide of iron may also be prepared by heating the
end of a bar of iron in Griffin's gas furnace, and then if a roll of sulphur
is brought in contact with the white hot iron, an intense action takes
place, and the bar of iron melts down in great drops of sulphide, which
exhibit, as they fall into water, the same curious repellent power already
observed with other metallic bodies, and especially with heated silver,
as shown by M. Boutigny.
Sulphuretted hydrogen is readily made by pouring dilute sulphuric
acid upon sulphide of iron; but as the escape of this gas into the air
of the laboratory is very disagreeable, not to say hurtful, to person and
property, it is better to fit up an apparatus (like that recommended by
Fresenius) when it is required to be constantly used. This arrangement
consists of an upper and a lower vessel made of lead, soldered with pure
lead. The sulphide of iron is placed on a shelf in the lower vessel, and
dilute sulphuric acid in the top one, and by the proper disposition of the
CC 2
388
IRON.
pipes the gas is always stored ready for use, whilst if any escapes it is
made to pass through ammonia, and being absorbed, forms that most
useful test called sulphide of ammonium.

E
N
O
O O
M
V
V
E
K
F
1
H
R
S
T
C
Fig. 217. 1. Perforated shelf of lead, on which the sulphide of iron is placed through the
aperture к, closed with well-greased leather. L. Opening for running off the sulphate of
iron when required. M. Filling tube, down which the dilute sulphuric acid is poured.
D H. Tube that conveys acid to I. CB. Tube from BFG, the generating vessel which
conveys the sulphuretted hydrogen to the glass z, and can be turned off by a cock at c.
B contains cotton-wool;
P. Tube to convey waste gas to the three Wolfe's bottles, R, S, T.
8, ammonia; T, ammonia. U is a safety-tube. When the sulphide of iron is placed on the
shelf 1, acid is poured into the top vessel v v, through M; and directly the cock o is
turned, the acid makes its way to the sulphide of iron on the shelf 1, in the lower vessel
EF G. As all the tubes are made of small diameter, the gas generated escapes only in
a limited proportion by the tube c E, and its pressure stops the descent of more acid from
v v. Directly the cock c is turned, the gas drives the acid back into v v, and then the
little gas that continues to escape from the acid which wets the sulphide of iron bubbles up
through the pipe D н, and escapes at P, from which it passes to the Wolfe's bottles, R, S, T,
containing the ammonia. As before, directly the cock c is turned, sulphuretted hydrogen
escapes, until, in the course of some weeks, the sulphide of iron has been entirely
decomposed.
The mineral called iron pyrites is a bisulphide of iron (FeS2), and under
the name of marcasite was much used formerly as an ornament, being set
like steel stud ornaments of the present time, in brooches, bracelets, &c.
STEEL.
Fourth Series.
389
The combination of carbon with iron is too important to be passed
by in silence, because it is the peculiar union or mixture of these two
elements which produces that valuable body called steel.
The only approach to an atomic combination of iron and carbon is in
the formula of Fe,C, obtained by heating iron in contact with powdered
charcoal, but that proportion is not maintained when the steel is worked
up for use; perhaps the presence of the definite compound of Fe,C, dif-
fused or alloyed through the mass of metallic iron, may produce those
remarkable effects which confer upon iron the properties of extreme
hardness and elasticity, with intermediate gradations. In Bessemer's
process it is shown, that by arresting the combustion of the carbon
(always present in the cast iron) at a particular point, steel is pro-
duced of fair quality and of reinarkable cheapness, because no interme-
diate processes are required. The cast iron, in fact, may be taken direct
from the blast furnace to Bessemer's apparatus, and converted at once
into steel. If (as Mr. Binks has shown) nitrogen appears to fulfil
some office in the conversion of iron into steel, then Bessemer's process
must again be the right principle, because in the act of driving air
through the molten iron large quantities of nitrogen are thus brought in
contact with the heated metal.
Mr. Binks has shown that the contact of red-hot charcoal with iron,
in the absence of nitrogen, will not produce steel, which is usually made
by a process called cementation. Bars of iron are laid in large fire-clay
boxes filled with powdered charcoal, which are then heated red hot and
kept in that state for six or eight days, with the partial admission of
air, until a sample bar taken from the box exhibits the unequivocal signs
of proper cementation by the appearance of numerous blisters on the
surface. The steel in this state is called "blistered steel," and its phy-
sical character is changed, being full of cavities and inequalities, which
must be closed by heating and hammering, or "tilting," and after having
undergone this process, it is called "tilted steel.”
Shear steel derives its name from the accidental circumstance of tailors'
shears being forged from it; it is made by breaking up the bars of "blis-
tered steel" into lengths of about eighteen inches, which are then bound
together in bundles containing four lengths, and also a fifth of double
length, whose projecting end is used as a handle. A thin steel rod is
twisted round them like the binding of a faggot of firewood, and the
whole is brought to a welding heat, sprinkled with sand, and placed
under the tilt hammer, and after sufficient hammering, the mass is
rolled and drawn out into a long rod; table knives, surgical instru-
ments, powerful springs, gun locks, &c., are made of shear steel.
Cast steel is manufactured by breaking up and melting the blistered
steel in proper crucibles, with a little bottle glass to protect the surface
of the melted metal from oxidation. Some fifteen years ago there used
to be a "steel works" at Millbank, where the author has seen all these
processes conducted, from the manufacture of the blistered steel to its
390
IRON.
conversion into "tilted," shear, and cast steel, but now the locality is
covered with the buildings of "Cubittopolis." It was at these works
the author saw the alloying of iron with manganese (under the auspices
of the spirited proprietor, Mr. Johnson), which was then a patented
process, but now the common property of all, because the unfortunate
patentee was deprived of his rights by some freak of the patent law.
The presence of manganese in iron converted into steel appears to
confer the property of lasting hardness to the edges of cutting instru-
ments, and the author has an excellent pair of razors made twenty years
ago with steel containing manganese.

Gooo
Kuup...
E.EVANS SC
Fig. 218. A Thirty-two Pounder Earth Battery (rear view).
As we have spoken of the Armstrong and Whitworth guns, mention
must be made of Mr. Krupp's cast-steel gun, and if this weapon could
be made and rifled at a cheaper price, it would probably compete very
favourably with those of the English engincers. Although one burst at
Woolwich, March 19, 1855, in consequence of certain liberties having
been taken with it by endeavouring to fire an expanding shot weighing
two hundred and fifty-nine pounds, instead of one of sixty-eight, for
which it was intended, the "Krupp cast steel" gun enjoys a high repu-
tation, proved by the fact that since the bursting of this piece Mr.
STEEL.
391
Krupp has manufactured guns and mortars for the arsenals of Prussia,
Russia, Wurtemberg, Switzerland, Egypt, and France.
Two 12-pounder howitzers made by Krupp were tried at Vincennes,
by firing three thousand rounds with the usual service charges, and
did not exhibit in the chamber or box the slightest trace of injury. One
of the guns was then subjected to the following severe proofs :-
20 rounds with 6 lbs. 9 oz. of powder and 2 balls.
10
5
دو
وو
13 lbs. 6 oz.
دو
3
6
At this point the experiments were wisely stopped, in order to preserve
so valuable a piece.
Steel may be distinguished from iron by letting fall a drop of nitric
acid on the surface, which produces a greyish black spot, whereas that
of iron is red with the same acid.
Steel filings produce a spark, during the act of combustion, which is
quite different from that of iron filings.
Steel remains permanently magnetic when properly magnetised,
whereas iron receives, but does not retain its magnetic power.
Steel possesses the curious property of assuming various colours and
degrees of hardness and elasticity, according to the temperature at
which it is heated and cooled, called the act of "tempering;" this pro-
perty again appears to connect the imponderable and invisible agent
heat with the assumption of some of the most important qualities of
steel.
The analyses of steel indicate the presence of from 1·94, 1·7, 1·72.
1·43, 1·13, 62 of carbon; so that from about a half to two per cent.
of that element appears to be amply sufficient to impart the properties
of steel to iron, provided that peculiar state of combined carbon and
probably nitrogen is obtained, which is not yet quite understood by
scientific men.
દ
Fifth Series.
Solutions of iron are used by dyers to produce the colour termed
"iron buff," which is obtained by passing a piece of calico cloth through
a solution of a persalt of iron, and then into one of an alkaline car-
bonate. Different shades are obtained by varying the strength of the
solutions.
Prussian blue is produced on cloth by first passing it through a so-
lution of acetate of iron (iron liquor), and afterwards into one of fer-
rocyanide of potassium, or it is obtained as an independent pigment by
precipitating a protosalt of iron with the red ferricyanide of potassium,
or a persalt with yellow ferrocyanide of potassium.
The addition of a few drops of a strong solution of sulphocyanide of
potassium to one of a persalt of iron, produces a blood-red colour, and
if the experiment is performed on the surface of a white plate, the ap-
pearance of blood is conferred upon the mixture of the two salts. The
392
IRON.
almost instantaneous disappearance of the blood-red colour is produced
by adding a little solution of tartrate of ammonia.
Ink is prepared by adding a solution of a protosalt of iron to a de-
coction of nutgalls and logwood, and the following recipe is recommended
by the author, who has used it for many years :-
Bruised galls.
Ground logwood
Sulphate of iron
Gum arabic
Water.
4 ounces.
1
2
""
1
1 quart.
Boil the galls and logwood in the water, say, for half an hour; make up
the quantity lost by evaporation, and strain through coarse calico; dis-
solve the sulphate of iron in a very little water, then add it to the de-
coction of galls and logwood and stir vigorously. Put the vessel on
one side for a day or two, and stir frequently; pour off or strain
through muslin; finally, add the ounce of powdered gum and a few
cloves. Lewis recommends with great propriety the use of com-
mon white wine (query, South African ?) instead of water, and he also
advises that a few broken gall nuts and iron nails be placed in the
bottle in order to keep the ink in good order.
Sixth Series.
The analysis of iron or an iron ore is usually performed by the wet
process, but the whole of the analytical steps to be taken are too com-
plicated to be described in the present elementary work. Supposing it
was desirable, for commercial purposes, to determine the per-centage of
iron in an iron ore, a given weight of the ore should be fused in a
platinum crucible, with four times its weight of pure dry carbonate of
soda, and whilst hot, but not red-hot, may be transferred to a porcelain
dish containing dilute hydrochloric acid. After all the fused mass is
dissolved out of the crucible, the latter may be washed and removed,
and the solution gently evaporated to dryness with the previous addition
of nitric acid until the whole of the iron is peroxidized. The residue
in the dish may now be moistened with hydrochloric acid, and allowed
to stand a few minutes; water is then added, the solution filtered, and
the matter left on the filter well washed, dried, ignited, and estimated
as silica or sand. The clear solution of iron is now precipitated with
an excess of ammonia, and the sesquioxide of iron collected on a calico
or paper filter, washed with cold and finally with boiling distilled water,
until the liquid that passes no longer affects a solution of nitrate of
silver. The washed oxide of iron is finally dried, ignited, and weighed,
and the iron estimated by the rule of proportion. As the equivalent
proportion of sesquioxide of iron (which is equal to 80, and contains
56 parts of metallic iron) is to the weight of the sesquioxide of iron
obtained from the above analysis, so is the metallic iron contained in the
equivalent proportion to the answer required-viz., the weight of me-
EXPERIMENTS WITH IRON.
393
tallic iron in the sesquioxide obtained by the analysis. The sesquioxide
of iron obtained by precipitation with ammonia will contain most pro-
bably alumina, but this may be separated by the following process.
The sesquioxide of iron, after powdering and fusion with carbonate of
soda, is dissolved in hydrochloric acid, and precipitated with an excess
of boiling potash, the latter dissolves the alumina, and, after filtration,
may be again precipitated from it by the addition of an excess of
chloride of ammonium. The bulky precipitate of alumina is then
collected, washed, dried, ignited, and weighed.
Seventh Series.
Iron is detected with great facility by means of ferrocyanide of potas-
sium, if it is in the state of the persalt; and by ferricyanide of potassium
when it exists as a protosalt; and it precipitated in the very marked
condition of Prussian blue, soluble in oxalic acid.
Sulphocyanide of potassium produces a blood-red colour with persalts
of iron.
Ammonia precipitates the hydrated red oxide from solutions of the
persalts of iron.
In all cases of testing for iron, the metal should first be peroxidized
by nitric acid.
Sulphuretted hydrogen produces in acid and neutral solutions a
precipitate of sulphur, and the peroxide of iron is reduced to the state of
protoxide.
Sulphide of ammonium precipitates black sulphide of iron (FcS),
which is decomposed by exposure to the air.
Protosalts of iron are precipitated by potash and ammonia in the
state of a white, rapidly becoming a dingy-green and reddish-brown
precipitate.
Nitric acid added to protosalts produces an increase of colour of a
brownish tint, in consequence of the change of the protoxide of iron
into sesquioxide.
Perchloride of gold is reduced to the metallic state in the form of a
brownish-black powder by the addition of a protosalt of iron.
The protosalts of iron are precipitated by the ferricyanide of potassium
(Fe,2 Cfy) as Prussian blue," which is decomposed by potash into a
reddish-brown powder, in consequence of the precipitation of peroxide
of iron.
Eighth Series.
Returning again to the all-absorbing topic of iron-mailed ships, the
following remarks by Mr. Lynall Thomas, in the Times, are most
interesting:-
"Notwithstanding that my opinion may be opposed to that of many
naval officers of great weight and experience in their profession, I am
nevertheless convinced that an iron-cased ship (unless her plates were of
a thickness utterly to preclude the possibility of her being a seagoing
394
IRON.
ship) might be destroyed from shore batteries, large frigates, or gunboats
at distances at which she could be hit with any degree of certainty, say
two or three thousand yards, and with guns very little, if at all, heavier
than the service 68-pounder gun.
"If Government will find the money I will engage to furnish them
with guns and projectiles which shall penetrate the sides of a vessel
cased with iron plates 4 inches thick, at the distance I have named.
"To show that this is no vain boast, I will explain how it can be done.
"It has been proved that a 68lb. shot of wrought iron will penetrate
a 4-inch iron plate with facility within the distance of 100 yards, the
initial velocity of the shot being less than 1800 feet a second.
"Those who know anything of the theory of projectile force will be
aware that a shot of 170lb. weight, striking an object with a velocity
of 1100 feet a second, would have a penetrating power quite equal to
that of the 681b. shot, while the general effect of the blow would be
enormously greater.
cr
According to the ordinary method of calculation, therefore, this shot
should penetrate an iron plate at almost any distance within its range
with the same facility as would a 681b. shot at a distance of 100 yards.
No iron-cased ship could come within the range of guns similar to
the one I have referred to without the risk of destruction, unless, as I
remarked, the plates of iron were so thick as to render the vessel an
inert, floating mass.”

lcd
Fig. 219. Eight-inch Gun on Rear-chock Carriage, covered by the Russian Mantelet.
METALS UNKNOWN TO THE ANCIENTS.

Fig. 220. A Brick Field. Clay the source of Aluminium.
CIIAPTER XI.
ALUMINIUM.
THIS metal, which has lately become very popular, derives its name
from alumina, so called by Morveau about 1760, because it is obtained
in the greatest state of purity from alum. Some years previously
Margraff had shown that the base of alum is an earth of a peculiar
nature, and quite different from all others, being an essential ingredient
and characteristic of every variety of clay, and imparting to it the pro-
perty of tenacity and plasticity by which good clay may be moulded
into almost every imaginable shape, and after being burnt, is rendered
hard and durable. The earth which conferred these properties was
called argil, and hence, when speaking of a rock which contains an
excess of clay, it is commonly said to be argillaceous.
The sources of the metal aluminium are, therefore, boundless, and it
lies at the doors of the richest and poorest members of society; the
universality of its presence enables us partly to realize the idea of Whit-
tington; and if the streets of London are not paved with gold, they do
contain an abundance of the beautiful silvery-like metal aluminium, now
being made and sold in jewellers' shops, and used for ornamental pur-
poses as brooches, bracelets, chains, &c., &c. Directly the announce-
396
ALUMINIUM.
ment was made of the discovery of the means of procuring aluminium
from clay in any quantity, the author was favoured by an offer of a large
clay farm and a loan of a thousand pounds to work it into crops of alumi-
nium. No one but a Dousterswivel could have accepted the tempting
chance of comfortable board and lodging and nice country air for a year
or so whilst preparing the apparatus to produce the aluminium, because (as
we shall see presently) there is a very roundabout and expensive chemical
process to be conducted before the valuable metal is extracted from the
comparatively worthless clay.
There is every reason to suppose that at some early period of the ex-
istence of our globe, its outer crust was represented by hard rocks,
which have crumbled down in the hand of "old Time," aided by the
action of water in the shape of rain and ice, and the consolidated snow
of the glacier grinding its slow and solemn path from the topmost peaks
of the highest mountain ranges. These crumbled and roughly-powdered
rocks have given us our various qualities of soils, the light containing
an excess of the sandy element; the stiff or heavy soil, the argillaceous,
clayey, or aluminium-bearing earth. Amidst such an abundant choice of
the raw material to work upon, it might be thought only necessary to
take a spade and remove a lump of clay from the field to the laboratory;
but it must be remembered that this raw material is somewhat too
coarse and crude-it contains the alumina (the source of the metal) in
a very insoluble form; the silica or sand is abundant, and would require
to be separated, and the clay itself is inconveniently bulky, in conse-
quence of the large quantity of water naturally contained within it, and
amounting at least to fifty per cent. of the whole weight. Aluminium
could certainly be obtained direct from clay, if the latter was first calcined,
so as to make it dry and porous, but not to fuse its particles, and then
digested for months with dilute sulphuric acid; the latter would dissolve
and combine with the alumina, and form sulphate of alumina, and when
this solution is mixed with a potash salt, such as sulphate of potash
or chloride of potassium, the alum may then be crystallized out. A
particular mineral is therefore preferred and selected, called alum slate,
which has a bluish- or greenish-black colour, and contains a certain pro-
portion of iron pyrites or sulphide of iron; this substance is decomposed
by exposure to the air into oxide of iron and sulphuric acid, and the
latter attacks the alumina and forms the basis of alum, which is a double
salt, being the sulphate of alumina and potash.
This alum slate is usually found in the neighbourhood of coal, and
indeed usually contains more or less bituminous matter; sometimes
the heat generated by the decomposing iron pyrites is so great that the
mineral takes fire, and originates those great natural fires in coal mines
which in former times were allowed to rage for years in "the waste" of
certain coal fields, but are now attacked in a scientific manner, and
extinguished by the method first proposed and carried out by Mr.
Goldsworthy Gurncy, and described in the "Playbook of Science."
The presence of bituminous matter in the alum slate imparts that
porosity and openness of the pores which admits the oxygen of the
MANUFACTURE OF ALUM.
397
air to the iron pyrites, and renders a smaller quantity of fuel sufficient
for the purpose of setting it on fire.
The ordinary alum rock is mixed with small coal, cinders, &c., and
formed into heaps and burnt precisely in the same manner as those
heaps of clay already alluded to, and visible in any new London neigh-
bourhood where that sticky soil is abundant. The combustion of the
alum rock heaps is kept as slow as possible, and water occasionally
added. It is conducted, of course, on a gigantic scale, so that the
works are never stopped for want of calcined alum rock. After
burning, the heaps are left exposed to the weather, care of course being
taken that the rain falling on and passing through the mass shall be
conveyed by proper drains and channels to the lixiviating pans or
cisterns, where the burnt rock, after "weathering," is digested with
water to dissolve out the sulphate of alumina. The cisterns are
arranged like a series of terraces, so that the cost of labour in lifting
and pumping is avoided. The weak solution passes in succession from
one cistern to the other, all of course coutaining burnt alum rock; and
when sufficiently strong, it is passed into proper receptacles, and a salt
of potash (such as sulphate of potash from the aquafortis makers, or
chloride of potassium) added; the potash salt unites with the sulphate
of alumina, and produces crystals of sulphate of alumina and potash.
These are subsequently recrystallized, and form the alum of commerce,
composed of
Sulphate of potash.
Sulphate of alumina
Water.
18.34
36.20
45.46
Alumina, the sesquioxide of the metal aluminium, is obtained either
from the sulphate of alumina, or from common alum, by precipitating
the solution with carbonate of ammonia, which throws down a bulky
white gelatinous precipitate of the hydrate of alumina; the solution
is heated, and the precipitate collected on a calico filter, and washed
with plenty of water, redissolved in hydrochloric acid, again precipi-
tated by ammonia, thoroughly washed, and dried at a gentle heat.
Gay Lussac has, however, proposed a much easier mode of obtaining
alumina, and recommends that ammonia alum be exposed first to a
gentle heat, to drive off the water of crystallization; and afterwards to
a red heat, which leaves the alumina pure. Ammonia alum is made
by substituting sulphate of ammonia for sulphate of potash in the
addition to the sulphate of alumina to form alum.
It is evident, from this condensed narrative, that the process of
separating alumina from clay is neither an easy nor a rapid one; and
then the chasm that divides the oxidized from the pure metal is a
wide one, and demands considerable skill to bridge it over.
The reduction of alumina to the metallic state is a process of great
interest; and one of the best papers ever read upon this subject is
that of the highly respected and talented secretary of the Society of
Arts, Mr. Peter le Neve Foster, M.A., and published in the "Journal'
398
ALUMINIUM.
!
of the Society, February 4th, 1859, from which the following historical
table is partly compiled :
1807.-Sir H. Davy discovered, by the agency of electricity, the
alkaline metals, one of which (sodium) is the key to the
reducing process for aluminium. Gay Lussac and Thénard
discovered that potash and soda are decomposed at a white
heat by iron; and they contrived a process for obtaining
the alkaline metals in larger quantities at a cheaper rate.
When this process was known in England, the alkaline
metals were made in small quantities, and sold at fabulous
prices, and not less than 57. per ounce. Mitscherlich,
Brunner, Donny, and Mareska improved the process further,
so that the alkaline metals were sold for about 30s. per
ounce.
1854.-M. H. Sainte-Claire Deville, assisted with funds from the
Emperor Napoleon III., prepared sodium so that the price
fell to 7s. 6d., then to 5s. per ounce.
1858.-Gerhard, at Battersea, by still further improvement, manu-
factured sodium at 1s. per ounce, or 16s. per pound avoir-
dupois.
In the first table the reader may glance at the gradual fall in the
price of sodium, due to the improved methods of production; and in
the second table the history of the preparation of aluminium is apparent.
1807.-Sir H. Davy did not obtain aluminium sufficiently pure to
investigate its properties. Alloys were, however, formed
with it that proved the existence of the metal.
1826.-Berzelius and Ersted failed to obtain aluminium.
1827.-Ersted succeeded in obtaining aluminium from the chloride
of aluminium; and the following notice, copied from
Hensman's "Répertoire de Chimie," appears in the "Phi-
losophical Magazine" for 1827, p. 391: "M. Ersted is
stated to have obtained the metal alumina (sic) by employing
the chloride of that earth. Pure alumina is heated to
redness, and then intimately mixed with powdered charcoal;
the mixture is introduced into a porcelain tube, and after
heating to redness, dry chlorine gas is passed over it. The
charcoal reduces the alumina, the metal combines with the
chlorine, and oxide of carbon is also formed. The chloride
of aluminum is soft, crystalline, and evaporates at a little
above the temperature of boiling water; it readily attracts
moisture from the air, and becomes hot when water is
added to it. By mixing with an amalgam of potassium,
containing much of the latter, and immediately heating the
mixture, chloride of potassium is formed, and the metal of
the alumina combines with the mercury. The amalgam
quickly oxidizes by exposure to the air. Being subjected
to distillation out of the contact of air, the mercury is
HISTORY OF ALUMINIUM.
399
volatilized, and a metallic button is left, which has the colour
and splendour of tin [they did not take the liberty of com-
paring it to silver]. M. Ersted has ascertained many pro-
perties belonging to the new metal and its amalgam, which
he promises to publish speedily."
1828.-Wöhler improved Ersted's process as follows: "When an
attempt is made to heat chloride of aluminum with potassium
in a porcelain tube, the action is so strong, and the extri-
cation of heat is so considerable, that the apparatus is
instantly broken. I therefore employed a small platina
crucible, the cover of which was kept on by a wire of the
same metal. At the moment of reduction the crucible
became intensely red hot, both within and without, although
it was but slightly heated; the metal of the crucible was
not sensibly acted upon. The operation may also be
effected in a porcelain crucible with a cover attached, and
indeed is recommended by Wöhler.
Excess of
potassium is to be avoided; for after it was oxidized it
would dissolve a portion of the aluminum. The reduced
mass is generally completely fused, and is of a blackish grey
colour. When all is cold, the crucible is to be thrown into
a large vessel of water; a grey powder is soon deposited,
which, when looked at in the sunshine, appears to be entirely
composed of small metallic plates; the powder is to be
washed with cold water, and then dried: it is the metal of
alumina."-Philosophical Magazine, 1828, p. 149.
1854.-Deville, assisted with funds from the Emperor Napoleon III.,
repeated Wöhler's experiments, and substituted sodium for
potassium, the combining proportion of Na being 23, whilst
that of K is 39.2, and thus reduced the quantity of the alkaline
metal required to nearly one-half. Deville's vessels of porce-
lain are only a repetition of Wöhler's. To produce the
chloride of aluminium, Deville forms a mixture of alumina
(prepared by Gay Lussac's process-viz., by heating am-
monia alum red-hot) and charcoal made into a paste with
oil, which is heated to a red heat in upright tubular retorts
of fireclay, similar to those used in the manufacture of
coal gas; and whilst in this state, a current of chlorine
gas is caused to pass into the retort, when chemical
reactions take place, and the chloride of aluminium sub-
limes over, and is condensed in proper vessels. This pro-
cess of Deville's, it will be seen, only differs from that
proposed by Ersted twenty-seven years before, in the addition
of oil to the charcoal and alumina, and in the employment
of a gas retort instead of a porcelain tube. The reduction
of the metal from the chloride was performed by Deville.
in the following manner : “A tube of Bohemian glass, 36
inches long, and about one inch in diameter, is placed in a
400
ALUMINIUM.
combustion furnace constructed for the purpose of heating
the tube. Chloride of aluminium is placed in one end
of the tube, and at the same extremity a current of
dry hydrogen gas is made to enter the tube, and sustained
till the operation is finished. The chloride is now gently
warmed by pieces of hot charcoal, in order to drive off any
hydrochloric acid it may contain; porcelain trays filled with
the metal sodium are introduced into the other end of the
tube, and the heat augmented by fresh pieces of glowing
charcoal, until the vapour of the sodium decomposes that
of the chloride of aluminium. Intense ignition usually
attends this reaction. At length, the metal aluminium is libe-

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Fig. 221. A. Hydrogen generator. B. Chloride of calcium bottle, for drying the gas.
c, D. The Bohemian-glass tube, containing the chloride of aluminium at E, and the tray of
sodium at F. G G. The chafing-dish, containing burning charcoal. п, н. Wire supports
for the tube.
rated and forms buttons, which are found in the tray, adhering
to a substance consisting of the mixed chlorides of alumi-
nium and sodium. The tray with its contents is now trans-
ferred to a porcelain tube, through which hydrogen gas is
passed. At a red heat, the double chloride distils into a
receiving vessel attached to the tube for the purpose; the
buttons of aluminium are collected, washed with water, and
subsequently fused together under a flux consisting of the
double chloride."
1855.-M. Paul Morin so far improved Deville's process as to con-
duct it, like Wöhler, in a crucible. The same year Dr.
Percy suggested the use of the mineral cryolite, (which is a
double fluoride of aluminium and sodium), as the ore from
which the metal could be obtained, and experiments were
made by the late Mr. Allan Dick with this mineral, and the
metal procured from it by the following process: "A pla-
tinum crucible is first lined with magnesia, by ramming
the same hard in, and subsequently cutting all out but a
thin lining. Into this alternate layers of cryolite and so-
dium are placed, with a thickish layer of cryolite on the top.
The crucible is covered with a tight-fitting lid, and heated
t
THE HISTORY OF ALUMINIUM.
401
to redness for about half an hour over the air blowpipe.
When cold, it is placed in water, and after soaking for some
time, the contents are removed, crushed in a mortar, and
washed by decantation. Two or three globules of aluminium
tolerably large, considering the scale of the experiment, are
obtained along with a great number of very small ones.
The large ones were melted together under chloride of po-
tassium."
Professor Rose, of Berlin, speaks highly of Dr. Percy's process, and
says, "I am of opinion that cryolite is the best adapted of all the com-
pounds of aluminium for the preparation of this metal. It deserves the
preference over chloride of aluminium and chloride of aluminium and
sodium, and it might still be employed with great advantage, even if its
price were to rise considerably."
1858-59.-Mr. Gerhard, an Englishman, established a factory at Bat-
tersea where aluminium and sodium are prepared in large
quantities, and at a cheaper rate than they can be procured
in Paris. Mr. Gerhard uses 270 parts by weight of pow-
dered cryolite, mixed with 150 of common salt, and into
this mixture are placed 72 parts of sodium cut into small
pieces. The whole is then thrown into a heated earthenware
crucible, previously lined with a melted mixture of cryolite
and salt, which mixture is also immediately poured over the
contents of the crucible, covering them to some little depth;
finally, the cover is put on. The crucible is now subjected
to a full red heat for two hours, and when the pot is un-
covered, the melted mixture is well stirred and then poured
out. The buttons of aluminium are found mingled with the
slag, and may be easily melted together by heating them in
a crucible with common salt. Theoretically, the quantity of
aluminium obtainable by this process should be one-third of
the weight of the sodium employed, but practically such a
result is never attained, and it does not extend beyond the
mean between one-third and one-fourth of the sodium used.
Previous to Deville's labours, aluminium sold at the rate of
407. sterling for 35 ounces avoirdupois; in 1856, when De-
ville came to England, the price was reduced to a much
lower rate, and the metal is now to be bought at about
3s. 9d. per ounce, or 67. 10s. for 35 ounces.
One of the most pleasing reminiscences of the author is connected
with the metal aluminium, and he records with gratitude the gracious
condescension of the Emperor Napoleon III., who not only deigned to
answer his application for a specimen of the then rare and much-sought-
after metal, but also forwarded to him a bar of aluminium, which was
exhibited at the Royal Polytechnic for many months, to the great delight
of the curious, who were all most anxious to handle and touch the metal
made from clay.
Ꭰ Ꭰ
402
ALUMINIUM.
The following letter was graciously sent with the bar of aluminium:
"Cabinet de L'Empereur, Palais des Tuilerics,
le 29 Juillet, 1855.
'MONSIEUR,-L'Empereur a daigné accueillir favorablement votre
demande. J'ai l'honneur de vous envoyer, par son ordre, un morceau
d'aluminium, destiné à la collection de métaux de l'Institut Polytech-
nique. Je vous prie de m'accuser réception de cet envoi.
CC
‘Recevez, Monsieur, l'assurance de mes sentiments très-distingués.
"Le Sous-chef du Cabinet de l'Empereur,
"Mr. John Pepper."
"ALBERT DE DALMAY.

Fig. 222. The Bar of Aluminium presented by the Emperor Napoleon III. to the
Author, during his Management of the Royal Polytechnic.
In an admirable lecture delivered at the Athenæum, Bristol, by Dr.
Griffin, that gentleman made the following remarks upon the probable
uses of aluminium, and exhibited a medal commemorative of her Majesty's
visit to Paris, struck for him at the Imperial Mint of France, in that
metal. After explaining the process of obtaining the aluminium, "Dr.
Griffin referred to the experiments of M. Deville, and the encourage-
ment afforded him by the French Academy, who voted the sum of two
Deville
thousand francs to defray the cost of continued researches.
soon procured enough of the metal to cast several ingots and have a
medal struck, which he presented to the Emperor, who, with that en-
ALUMINIUM AND NAPOLEON III.
403
lightened spirit which characterizes the French in such matters,
authorized experiments on a large scale to be continued at his own
cost. It was worthy of remark, that from the first, Deville had repu-
diated all affectation of mystery, or claim to exclusive pecuniary profit;
all his results had been constantly reported to the Institut, and his
operations themselves thrown open to scientific and practical men.
That liberality of feeling is one of the most pleasing features of the
French character; in Paris any intelligent inquirer was everywhere wel-
come, and met with nothing but courtesy and kindness. M. Deville
was not in Paris during the lecturer's stay, but at his splendid laboratory
in the Ecole Normale every information on all points connected with
his researches was freely rendered, and he took sketches of the ap-
paratus. Considerable quantities of the metal had been procured by
M. Deville, there being in the Paris Exhibition a pile of a dozen bars,
besides a variety of articles manufactured from it. The properties of
aluminium in its new form were thus described. It was a white metal
susceptible of a high polish; its white was not so pure as silver, espe-
cially when it had been worked, but had a decided shade of blue, so that
it was hardly likely to replace silver for ornamental plate; but it would
make capital mustard and egg spoons, as it was not in the least affected
by sulphuretted compounds, whether gaseous or otherwise, which so
instantly blackened silver. It retains its lustre in the air, whether
moist or dry, for any length of time and at all temperatures; even when
kept melted it hardly oxidized like zinc or tin, though each fragment
became covered with an extremely slight violet film of oxide, which
prevented its running together unless stirred up with a rod. If covered
with chloride of potassium, or the double chloride of aluminium and
sodium, this superficial oxidation was prevented and the smallest
globules united in one. Not only had boiling water no action upon
pure aluminium, but even diluted sulphuric acid and strong nitric acid,
which vehemently attacked silver, had no action upon it in the cold, and
it was not sensibly affected by being plunged into melted nitre, potass,
or sulphuret of potassium-a threefold test which no other metal, not
even gold or platinum, can withstand, and hence it would be extremely
valuable in certain laboratory vessels. Muriatic acid, however, rapidly
dissolved it, even in the cold, from its powerful attraction for chlorine.
Alkaline solutions also acted on it, and were, in fact, useful for cleaning
it. The metal was nearly as hard as iron, but could be softened by an-
nealing; it had great rigidity and tenacity, and when a bar was broken
across, it showed a fine-grained fracture, like cast steel. It could be
turned, chased, and filed with the greatest facility, and without clogging
the tools. In the Paris Exhibition there were several examples of its
working capabilities. M. Christofle, the well-known Parisian gold- and
silversmith, exhibited forks and spoons, and also a cup made from it;
and, to show its hardness and strength, it might be mentioned that this
cup, though quite thin, could be allowed to fall out of the hand on to a
stone pavement without being indented. Aluminium could be drawn into
wire as fine as a hair, and rolled into extremely thin sheets. Small traces
DD 2
404
ALUMINIUM.
of iron much impaired its malleability, and rendered its colour bluer and
duller; when considerably impure it became much more markedly crys-
talline, both on the exterior and in its texture throughout. It could be
plated on copper, and soldered with ease. It melted at a full red
heat, about the same as silver, and took a good impression by casting.
It also struck admirably under the die, as was better seen in large
medals than in the small one produced, which was struck for him with
some trouble at the French Mint, through the kindness of the Director,
the distinguished chemist, M. Pelouze. He remarked, however, that in
future years that would become a notable historical souvenir, being, as
it was, a memento of the auspicious and magnificent visit of a sovereign
of England to the capital of France, impressed on a material belonging
to the same epoch. Thus it would be seen that aluminium fulfilled every
requisite for a multiplicity of industrial applications, but it had yet
another remarkable feature. Its density was intermediate between that
of the alkali metals which floated on water, and the ordinary heavy
metals. It was considerably lighter than flint glass, being only two-
and-a-half times heavier than water. Thus, bulk for bulk, it was four
times as light as silver, and but little more than one quarter the weight
of copper. Hence, it had been suggested that, if it could be procured
cheaply enough, its hardness, lightness, and incapability of rusting
would render it admirably adapted for the helmets and cuirasses of the
cavalry; it would make splendid field-guns, as strong as the present
oues, and not one-third their weight; and, in sheets, it might serve as
an incorrodible roofing, far lighter and more durable than even zinc.
It would also admirably replace copper, if not silver, for the purpose
of coinage. A crownpiece in aluminium would hardly weigh more than
a shilling in silver; or, a piece the size of a penny, about as much as a
copper farthing. The same qualities of lightness, hardness, and incor-
rodibility also fit it excellently for the beams of delicate balances, and
the minute weights used in analysis. It would also make admirable
utensils for the more delicate operations of cookery, replacing the
copper ones, which rendered pickles and soups so poisonously green;
it would also form excellent vessels for manufacturing chemists; it
being extremely sonorous, would make capital bells, and aluminium coins
would have a ring" equal to those of silver. The present price of
aluminium, as retailed by Messrs. Rousseau, was 37. 10s. an ounce, but
that was merely a fictitious price, the demand for it as a chemical
curiosity greatly exceeding the very limited supply, and the makers
having to reimburse themselves for much outlay in apparatus and pre-
liminary experiments. In estimating its cost, they must never forget its
singular lightness; even at its present price, bulk for bulk, it was ten
times cheaper than gold, and only three times the price of silver; but, in
looking forward, he could see no improbability in its being made for 8s.
or 10s. a pound, and then it might at once replace copper for coinage,
for it is nearly four times as light, so that pieces of half the present
size would be of the same value as now. Time alone could decide the
question of the cost of the metal. Much depended on the scale on
r
THE PROPERTIES OF ALUMINIUM.
405
which any product was manufactured. Phosphorus, which in its early
days, was an object of curiosity like aluminium now, sold for a guinea
an ounce; fifteen years ago it was as much per pound; now, though its
preparation was difficult and dangerous, it was about 3s. 6d. a pound,
solely from its commercial demand for the manufacture of that insignifi-
cant but useful little article the lucifer-match. Aluminium formed alloys
with most of the metals, but hardly at all with lead, and it would not in
the least amalgamate with mercury, which might be useful in some of
its future applications. After dwelling for a short time upon these
alloys, which he said had not been much studied, the lecturer closed his
remarks by observing that Mr. Gore, an able electro-chemist of Bir-
mingham, had presented the Society of Arts with specimens of copper
and brass, coated with white and lustrous aluminium and silicium by the
usual electro-plating process from the solution of alumina, obtained by
boiling pipe-clay with sulphuric acid, or from the common siliceous
sandstone dissolved by hydrofluoric acid, so that silicium might here-
after be destined to play as prominent a part as its sister aluminium;
and assuredly it was a proud triumph for chemistry, amidst the count-
less benefits she had conferred on mankind, that she had wrung their
hidden metals from despised clay and paving-stones to add to the com-
forts and ornament of their daily life, thus, as it were, bringing home
Peru and Mexico to their very doors."
Aluminium appears to take an intermediate position between the
precious metals and the common ones, and Professor Graham considers
that it ought to stand at the head of the common metals. It possesses
some properties analogous to those belonging to iron, such as a passive
state in nitric acid; it is also slightly magnetic, and acquires by pres-
sure some of the elasticity of iron. Aluminium combines with carbon
and silicium, forming brittle and friable compounds somewhat similar to
those procured from iron when combined with the same elements, and,
like iron, it does not unite with mercury.
One of the chief objections urged against the use of aluminium is its
extreme liability to abrasion; but even then, its alloys are proved to be
most valuable, especially the alloy with copper, or "aluminium bronze,"
as it is considered that if this could be procured sufficiently cheap,
superior cannon might be cast of it.
The employment of aluminium by dentists appears to be limited to the
use of the cast metal, as the forged aluminium is frequently attacked
and destroyed by the saliva of the mouth. Aluminium and iron may
probably form alloys which will be of the very highest importance. At
the present time aluminium is to be had in London, from any of the
silversmiths, at a very cheap rate, made into jewellery and ornaments
of various kinds, bracelets, combs, pins, seals, penholders, tops of ink-
stands, porte-monnaies, shirt-studs, harness, statuettes, candelabra,
candlesticks, bells, tubes, &c.
406
ALUMINIUM.
EXPERIMENTS WITH ALUMINIUM.
First Series.
The combining proportion of this metal is 13-7, and its specific gravity
is 2-6, being nearly that of glass; it is malleable and ductile, and pos-
sesses considerable tenacity; it conducts electricity eight times better
than iron, and is considered to be about equal to silver in that respect.
It melts at a temperature between that required to fuse zinc and silver.
It is not readily attacked by oxygen gas; and Deville ascertained that
it could be exposed for a lengthened time to the action of a current of
air in the cupelling furnace without undergoing any change.
The only oxide of aluminium known at the present time is the sesqui-
oxide, called alumina, having the same relation to oxygen as the ses-
quioxide of iron, and represented by the formula Al,O,. The manner
of obtaining this oxide from ammonia-alum has already been explained
at p. 397. The state of aggregation of the metal aluminium has no
doubt a great deal to do with its combustibility in oxygen. Deville,
as already observed, exposed some melted aluminium in a cupel, but did
not succeed in setting it on fire; but Wöhler, using the finely-divided
metal in his experiments, observed that when the aluminium was heated
to redness in the air, it took fire and burnt with great brilliancy into
white and tolerably hard alumina. He also states that when it is pro-
jected on the flame of a candle, it emits sparks as brilliant as those of
iron burning in oxygen gas. It also burns in oxygen gas with a splen-
dour which the eye can hardly support, and with so much heat that
the resulting alumina is, in part at least, fused into yellow fragments,
which are as hard as corundum, and not only scratch, but absolutely
cut glass. In order to obtain this combustion in oxygen, it is necessary
first to heat the finely-divided aluminium red hot before plunging it into
the gas. Indeed, these results are very similar in effect to those obtained
with antimony or bismuth in chlorine gas; when these metals are in-
troduced in lumps into the gas, the action is slow and unaccompanied
with the evolution of fire; but if they are first reduced to powder, and
then dropped into the chlorine gas, they take fire and produce at once
the chlorides of these metals.
Alumina appears to perform the part of an acid, and combines with
potash, magnesia, baryta, strontia, &c., forming aluminates of these
bodies. When first precipitated as an hydrate of alumina, it is ex-
tremely bulky, and very much resembles jelly or pectic acid, and if
allowed to dry slowly, it gradually contracts into a substance that looks
like fine glue. Dr. Thompson found that 100 grains of precipitated
alumiua left to dry on a paper filter during two months, at a tempera-
ture not exceeding 60° Fah., retained so much water, that when heated
red hot it lost 51-3 grains of water, or rather more than half its weight.
After being heated red hot, a great condensation of water appears to
take place within its pores when cold; and Berzelius found that 100
parts, after being ignited, gained 15 grains from a dry atmosphere,
DANIELL'S REGISTER PYROMETER.
407
and 33 grains from a humid one; hence, in estimating and weighing this
substance in analysis, great care must be taken to prevent it absorbing
moisture. Like sponge, alumina shrinks as it yields up its water, and
upon this property is founded the pyrometer of Wedgwood, which
is intended to measure high degrees of heat by the amount of the con-
traction of regularly shaped pieces of china clay; and as we have had
frequent occasion to speak of the temperature at which metals fuse, it
may be interesting here to describe the late Professor Daniell's im-
provement on the pyrometer of Wedgwood. The latter instrument
afforded incorrect results; partly on account of the difficulty of obtain-
ing clay of uniform composition, and partly because the principle upon
which it is founded is not a correct one, for clay will contract as much
by a long-continued low heat as by a short continuance of a high one.
Daniell's Register Pyrometer consists of two parts, which may be dis-
tinguished as the register and the scale. The register is a solid bar of
blacklead earthenware, highly baked; in this a hole is drilled, into which
a bar of any metal, six inches long, may be dropped, and which will
then rest upon its solid end. A cylindrical piece of porcelain, called
the index, is then placed upon the top of the bar, and confined in its
place by a ring or strap of platinum passing round the top of the register,
which is partly cut away at the top and tightened by a wedge of porce-
lain. When such an arrangement is exposed to a high temperature, it
obvious that the expansion of the metallic bar will force the index
forward to the amount of the excess of its expansion over that of the
blacklead, and that, when again cooled, it will be left at the point of
greatest elongation. What is now required is the measurement of the
distance which the index has been thrust forward from its first position;
and this, though in any case but small, may be afforded with great pre-
cision by means of the scale. This is independent of the register, and
consists of two rules of brass, accurately joined together at a right angle
by their edges, and fitting square upon two sides of the blacklead bar.
At one end of this double rule a small plate of brass projects at a right
angle, which may be brought down upon the shoulder of the register,
formed by the notch cut away for the reception of the index. A move-
able arm is attached upon this frame, turning at its fixed extremity
upon a centre, and at its other carrying an arc of a circle whose
radius is exactly five inches, accurately divided into degrees and thirds
of a degree. Upon this arm, at the centre of the circle, another lighter
arm is made to turn, one cnd of which carries a nonius with it, which
moves upon the face of the arc, and subdivides the former graduation
into minutes of a degree; the other end crosses the centre, and termi-
nates in an obtuse steel point, turning inwards at a right angle.
When an observation is to be made, the metallic bar is placed in the
cavity of the register, the index is to be pressed down upon it and
firmly fixed in its place by the platinum strap and porcelain wedge. The
scale is then to be applied by carefully adjusting the brass rules to the
sides of the blacklead bar, and fixing it by pressing the crosspiece a
(Fig. 223) upon the shoulder; holding the whole together steadily in the
408
ALUMINIUM.
left hand, the moveable arm should be so placed that the steel point (h) of
the other leg of the compasses may rest upon the edge of the porcelain

#
D
a
d
f
A
A
B
ė
Fig. 223. Daniell's Pyrometer. No. 1 is the register. D D D D is the blacklead bar with
its cavity, o o. At pppp it is cut away to the depth of half the bore. g g is the porce-
q
lain index, which is placed upon the top of the metallic bar, and confined to its place by
the pressure of the platinum strap r, so acting by the force of the small porcelain wedge 8.
No. 2 represents the scale. AA is the principal brass rule, upon the under side of which
the frame a aa aa a is adjusted by the screws bb, and which supports upon its bent
extremity c, the arm в moving upon the centre d, and terminating in the arc of the circle
e e.
cc is the lighter arm moving upon the centre f upon the arm B, and carrying at one
end the nonius g, and at the other the steel point h, the distance of which from the centre
fis exactly half-an-inch, or one tenth of the radius fg, and equal to the distance of the
two centres fd. I is a small lens, represented as lying down, but which may be raised
by the centres k and perpendicularly above the nonius to facilitate the reading.
is the steel spring, which, being fixed in a cavity cut out of the arm B, presses upon a small
pin n on the arm c, and throws the radius back to the commencement of the arc.
>
m m
EXPERIMENTS WITH ALUMINIUM.
409
index, against which it will be pressed with some force by the spring;
then, moving the arm gently forward with the right hand, the point will
slide along the end of the index till it drops into a small cavity (t)
formed for its reception, and which exactly coincides with the axis of
the metallic bar in the register, and the centre of motion of the com-
passes on the brass rule. The minute of the degree must then be noted
which the nonius indicates upon the arc. A similar observation must
be made after the register has been exposed to an increased tempera-
ture and again cooled; and the number of degrees or minutes which
the nonius will then mark will, by a simple calculation from the known
length of the radii and angle, give the length of the chord comprised
between the original position of the compasses and the point to which
they have moved in the distance which the index has been forced for-
ward. Such an operation," says Daniell, appears complex in the
description, but is in fact extremely simple after a little practice, and
does not require more than a few seconds for its performance. The
scale of the pyrometer being completely detached from the part which
is exposed to the fire, obviates one important objection which has always
been made to other contrivances of the same nature, from the uncertain
degree of heat and expansion to which they are liable, while the sim-
plicity of that part of the arrangement which alone is subjected to great
heats, renders it little liable to injury; and, together with the cheapness
of the material of which it is constructed, occasions but a trifling ex-
pense for replacing it when injured."-Phil. Mag., 1831.
Second Series.
cr
Chlorine, bromine, and fluorine unite with aluminium. The prepa-
ration of the chloride has already been explained; and as the bromide
and fluoride of aluminium do not present any very interesting chemical
features, the bare mention of them may be sufficient here. The "topaz"
consists almost entirely of fluoride of aluminium united with alumina.
Third Series.
Alumina is the cheapest and the most extensively employed of all
mordants for fixing colouring matters on cotton, &c. Four kinds of
solutions are used for this purpose: viz., 1. A solution of common alum.
2. A solution of common alum, partly neutralized with an alkali, called
basic alum. 3. A solution of alumina in acetic acid, called "red
liquor.” 4. A solution of alumina in caustic potash, called aluminate
of potash. Cotton cloth, washed free from stiffening, steeped in a
solution of alum, partly dried, and dipped in a decoction of "fustic,'
the wood of the Morus tinctoria, affords a much brighter yellow than if
the cloth had not been prepared with the mordant.
A piece of cotton cloth impregnated with basic alum, and dipped in
a hot infusion of cochineal, is dyed a beautiful crimson.
Another piece of cloth dipped in acetate of alumina (" red liquor”)
affords a beautiful orange, if placed in a mixed decoction of cochineal
410
ALUMINIUM.
and quercitron; the exact shade can only be acquired by practice and
a nice adjustment of the quantities of the materials used.
When a piece of cloth saturated with the aluminate of potash is
exposed to the air, and especially in occupied rooms, the carbonic acid
in the atmosphere is entirely absorbed, combines with the potash, and
the alumina is precipitated in the fibre of the cloth; hence the im-
portance of one of the stages of mordanting cloth-viz., "hanging,"
or "ageing," and the free exposure of the goods to plenty of air. The
alumina deposited in this manner has a peculiar affinity for colouring
matter.
Fourth Series.
Alumina unites with silicic acid, and forms a most valuable series of
natural earths and clays, which are employed for a great number of
purposes, and especially in the fabrication of pottery and porcelain.
Amongst the minerals that consist of alumina and silica are to be
named pumice-stone and china clay; and it is from the best description
of clay that those beautiful works of art called Parian or statuary
porcelain are made by the famous house of Copeland, in Bond-street.
The author is indebted to Mr. Frederick Battam for the following in-
teresting facts in connexion with this manufacture :-
r
Statuary Porcelain.-The articles under the head of 'Statuary
Porcelain' are produced by 'casting.' As the most direct mode of
illustrating this process, let us suppose the object under review to be
a figure or group, and this we will assume to be two feet high in the
model. The clay, which is used in a semi-liquid state, about the con-
sistency of cream, and called 'slip,' is poured into the moulds forming
the various parts of the subject (sometimes as many as fifty); the
shrinking that occurs before these casts can be taken out of the moulds
(which is caused by the absorbent nature of the plaster of which the
mould is composed) is equal to the reduction of one inch and a half in the
height. These casts are then put together by the 'figure-maker;' the
seams (consequent upon the marks caused by the subdivisions of the
moulds) are then carefully removed, and the whole worked upon to
restore the cast to the same degree of finish as the original model. The
work is then thoroughly dried, to be in a fit state for firing, as, if put in
the oven while damp, the sudden contraction consequent upon the great
degree of heat instantaneously applied, would be very liable to cause it
to crack; in this process it again suffers a further loss of one inch and
a half by evaporation, and it is now but one foot nine inches. Again,
in the firing' of the 'bisque' oven, its most severe ordeal, it is dini-
nished three inches, and is then but eighteen inches high, being six
inches, or one fourth less than the original. Now, as the contraction
should equally affect every portion of the details of the work, in order
to realize a faithful copy, and as added to this contingency are the risks
in the oven of being over-fired,' by which it would be melted in a
mass, and of being short-fired,' by which its surface would be im
perfect, it is readily evident that a serics of difficulties present them-
COPELAND'S STATUARY PORCELAIN.
411
selves, that require considerable practical experience successfully to
meet.
t
"The moulds are made of plaster of Paris, which, when properly pre-
pared, has the property of absorbing water so effectually, that "the
moisture is extracted from the clay, and the ware may be removed
from the mould or delivered' with care and rapidity. Prior to use,
the plaster (gypsum) is put into long troughs, having a fire running
underneath them, by which means the water is driven off, and it remains
in a state of soft, fine powder; and if its own proportion of water be
again added to it, it will immediately set into a firm, compact body,
which is the case when it is mixed to form the mould.
"The following are the degrees of temperature in which the different
brauches work:—
Plate-makers' hothouse
Dish-makers' hothouse
Printers' shop
Throwers' hothouse
•
108° Fahrenheit.
106°
90°
98°
دو
The workmen for whom the temperature of the hothouse' is graduated
require that heat for drying their work and getting it off the moulds.
The outer shops in which they work may be from five to ten degrees
less.
The
Printing. There are two distinct methods of printing, in use, for
China and earthenware-one is transferred on the bisque,' and is the
method by which the ordinary printed ware is produced, and the other
is transferred on the glazed. The first is called 'press printing,' and
the latter bat printing. The engraving is executed upon copper
plates, and for 'press' printing is cut very deep, to enable it to hold a
sufficiency of colour to give a firm and full transfer to the ware.
printer's shop is furnished with a brisk stove, having an iron plate upon
the top, immediately over the fire, for the convenience of warming the
colour while being worked, also a roller, press, and tubs. The printer
has two female assistants, called 'transferers,' and also a girl called a
'cutter.' The copper-plate is charged with colour, mixed with thick
boiled oil, by means of a knife and 'dabber,' while held on the hot
stove-plate, for the purpose of keeping the colour fluid; and the en-
graved portion being filled, the superfluous colour is scraped off the
surface of the copper with a knife, and is further cleaned by being
rubbed with a 'boss' made of leather. A thick firm oil is required to
keep the different parts of the design from flowing into a mass or be-
coming confused while under the pressure of the rubber in the process
of transferring. A sheet of paper of the necessary size, and of a pecu-
liarly thin texture, called 'pottery tissue,' after being saturated with a
thin solution of soap and water, is placed upon the copper plate, and
being put under the action of the press, the paper is carefully drawn off
again (the engraving being placed on the stone), bringing with it the
colour with which the plate was charged, constituting the pattern.
This impression is given to the 'cutter,' who cuts away the super-
412
ALUMINIUM.
fluous paper about it: and if the pattern consists of a border and centre,
the border is separated from the centre, as being more convenient to fit
to the ware when divided. It is then laid by a transferrer upon the
ware, and rubbed first with a small piece of soaped flannel, to fix it, and
afterwards with a rubber formed of rolled flannel. This rubber is
applied to the impression very forcibly, the friction causing the colour
to adhere firmly to the 'bisque' surface, by which it is partialled imbibed;
it is then immersed in a tub of water, and the paper washed entirely
away with a sponge; the colour, from its adhesion to the ware, and
being mixed with oil, remaining unaffected. It is now necessary, prior
to 'glazing,' to get rid of this oil, which is done by submitting the
ware to heat in what are called 'hardening' kilns, sufficient to destroy
it and leave the colour pure. This is a necessary process, as the glaze,
being mixed with water, would be rejected by the print while the oil
remained in the colour.
The 'bat' printing is done upon the glaze, and the engravings are,
for this style, exceedingly fine, and no greater depth is required than for
ordinary book engravings. The impression is not submitted to the heat
necessary for that in the 'bisque;' and the medium of conveying it to the
ware is also much purer. The copper-plate is first charged with linseed-
oil, and cleaned off by hand, so that the engraved portion alone retains
it. A preparation of glue being run upon flat dishes about a quarter
of an inch thick, is cut to the size required for the subject and then
pressed upon it, and being immediately removed, draws on its surface
the oil with which the engraving was filled. The glue is then pressed
upon the ware with the oiled part next the glaze, and being again re-
moved, the design remains, though, being in a pure oil, scarcely per-
ceptible. Colour, finely ground, is then dusted upon it with cotton-
wool, and a sufficiency adhering to the oil, leaves the impression perfect,
and ready to be fired in the enamel kilns.
"Enamel Painting.-Enamel colours are metallic oxides incorporated
with a fusible flux: gold precipitated by tin furnishes the crimson,
rose, and purple; oxides of iron and chrome produce reds; the same
oxides yield black and brown, also obtained from manganese and cobalt;
orange is from oxides of uranium, chrome, antimony, and iron; greens
from oxides of chrome and copper; blues from oxides of cobalt and
zinc. The fluxes are borax, flint, oxide of lead, &c. They are worked
in essential oils and turpentine, and a very great disadvantage under
which the artist labours is, that the tints on the palettes are in most
cases different to those they assume when they have undergone the
necessary heat, which not only brings out the true colour, but also, by
partially softening the glaze and the flux, causes the colour to become
fixed to the ware. This disadvantage will be immediately apparent in
the case where a peculiar delicacy of tint is required, as in flesh tones,
for instance; but the difficulty does not end here, for, as a definite heat
can alone give to a colour a perfect hue, and as the colour is continually
varying with the different stages of graduated heat, another risk is
incurred that resulting from the liability of its receiving the heat

PRECIOUS STONES AND ARTIFICIAL GEMS.
413
in a greater or less degree, termed 'over-fired' and 'short-fired.'
As an instance of its consequence, we will cite rose-colour or crimson,
which, when used by the painter, is a dirty violet or drab; during the
process of firing, it gradually varies with the increase of heat from a
brown to a dull reddish hue, and from that progressively to its proper
tint. But if, by want of judgment or inattention in the fireman, the
heat is allowed to exceed that point, the beauty and brilliancy of the
colour are destroyed beyond remedy, and it becomes a dull purple. On
the other hand, should the fire be too slack, the colour is presented in
one of its intermediate stages, as already described; but in this case
extra heat will restore it. Nor must we forget to allude to the casual-
ties of cracking and breaking in the kilns by the heat being increased
or withdrawn too suddenly a risk to which the larger articles are
peculiarly liable. These vicissitudes render enamel painting in its
higher branches a most unsatisfactory and disheartening study, and
enhance the value of those productions which are really successful and
meritorious."
Fifth Series.
Alumina, coloured chiefly with oxide of iron, is found crystallized in
nature, and is then valued at enormous sums, under the names of the
sapphire, the ruby, and the emerald, which are varieties of the very
hard mineral termed corundum-a mineral that justly deserves the title
of adamant, and in its more common variety is the well known hard
substance sprinkled on glazed cotton or paper, and termed emery or
scouring paper.
The sapphire is the next in value to the diamond (supposing always
that the gem is free from specks or flaws); it is so hard that it is cut
with diamond powder, and polished by means of emery. The most
highly-prized variety is the Oriental ruby, of a crimson and carmine red
colour. The cochineal red variety is the "Balais Ruby," so named
from Balacchan, the Indian name of Pegu, where this variety is found.
Amongst the beautiful jewels displayed at the first exhibition in Hyde
Park were some remarkable specimens of rubies from Hunt and
Roskell, the eminent jewellers of Bond-street. One, a large Oriental
ruby of an oval shape and of a deep crimson colour, consisting of a
mixture of red and purple, and most beautifully cut, weighed 84 grains.
Another "Balais" ruby, of an oblong shape, and of a deep pink, very
brilliant, and weighing 53 grains, was considered to be unsurpassed in
beauty and perfection; likewise sapphires of a still larger size, and one
weighing 180 grains, of a light blue colour, and cut in steps with exqui-
site lustre, will long be remembered by all those who admire precious
stones.
It has already been observed at page 295 that natural minerals may
be imitated perfectly by artificial processes; and the same remark can
be made with respect to these costly jewels. M. Ebelsman, of the
Sèvres Porcelain Works, near Paris, has succeeded in making the arti-
ficial "ruby;" not, it must be understood, as a copy in glass, but
414
ALUMINIUM.
veritably and honestly out of the same substance (alumina) of which
rubies and sapphires are naturally composed. The process consists in
employing a solvent which shall first dissolve the mineral or its con-
stituents, and may thus, either upon its removal, or by a diminution
of its solvent powers, permit the mineral to aggregate in a crystalline
state. The solvents are boracic acid, borax, phosphate of soda, phos-
phoric acid, &c.; but the first named is that preferred by Ebelsman,
who mixes together certain proportions of alumina, magnesia, oxide of
chromium, or oxide of iron, and fused boracic acid; these are then
placed in a crucible made of refractory alumina enclosed in a second one,
and both carefully protected by covers from air, dust, and dirt, and the
whole exposed to the intense heat of a porcelain or other furnace. The
materials are dissolved in the boracic acid, and then, as the heat is
continued, the latter evaporates, and the alumina and colouring
materials are found combined and crystallized, and present the
exact appearance of the Spinel ruby. In this way crystals having
the same form, hardness, colour, specific gravity, composition, and
effect on light as the true ruby, the cymophane, and other precious
stones, were prepared, and were found to be identical in composition
with them.*
Analysis frequently reveals strange and curious truths, and the pro-
duction of artificial "ultramarine" is another example of the imitation
of one of nature's most beautiful mineral works. The "artificial ultra-
marine" is made by fusing together soda, carbonate of soda, sulphur,
silica, ferruginous clay; and the receipt is copied from the natural spe-
cimens of this valuable substance, which consists of—
Silica
Alumina
Soda
•
Sulphuric acid
Sulphur
Iron
Lime
Chlorine
Water
•
45.40
31.67
9.09
5.89
0.95
0.86
3.52
0.42
0.12
97.92
When the Spinel ruby weighs sixteen grains it is considered of equal
value to a diamond of half the weight. Corundum occurs in a crys-
tallized state, and the author has a good specimen from India, a six-
sided prism, about three inches long, and from one inch to an inch and
a quarter wide from plane to plane, called the "Sawmee Stone," from
the god Sawmee. This mineral is used in India for cutting all precious
stones, and when mixed with shellac, forms their only "grindstone;"
* See Annales de Chimie, 1848, tom. xxii. p. 211.
CROWN JEWELS.
415
and as the precious stones alluded to are all varieties of this mineral,
the analysis of the specimen is given below :-
Alumina
Silica
•
Oxide of iron.
89.0
9.0
2.0
100.0
In the collection of crown jewels at the Tower of London are some
magnificent specimens of the sapphire and ruby, which are well worthy
of a visit of inspection, and are very nicely described by the lady at
present in charge of them.

Fig. 221. The Crown and Sceptre of England.

1.
Fig. 225. The supposed Origin of the Name of the Metal.
CHAPTER XII.
ANTIMONY.
THE origin of the name of this metal is somewhat peculiar, and in
reading Basil Valentine's "Triumphant Chariot of Antimony," it will
be noticed that he speaks of the metal "yet crude, it fattens swine, how?
Therefore let men know that antimony not only purgeth gold, cleaneth
and frees it from every peregrine matter, and from all other metals, but
also (by a power innate in itself) effects the same in men and beasts.
If a farmer purpose in himself to keep up and fatten any of his cattle
—as, for example, an hɔg-two or three days before let him give to the
swine a convenient dose of crude antimony, about half a drachm, mixed
with his food, that by it he may be purged; through which purgative
he will not only acquire an appetite to his meat, but the sooner increase
and be fattened. And if any swine labour with a disease about his
liver, antimony causeth it to be dried up and expelled." It is said that
certain worthy monks, having experimented upon some hogs with anti-
THE ORES OF ANTIMONY.
417
mony, discovered that it hastened their fattening, and, with a laudable
desire to avoid the effects of fasting, they treated themselves to the
same medicament, which in their case unfortunately proved fatal; and
hence the origin of the name of antimony-avrı, against, and povos,
one who lives alone, a monk.*
*
στιμμι,
Although, apparently, not acquainted with the metal, the ancients
appear to have known the oxide of antimony, to which they gave the
name of oriµµi, stibium. Pliny speaks of it, and says the oxide was
used as a remedy for sore eyes. He not only describes the compound,
but gives a method of preparing the mineral balsam. The sulphide of
antimony, called the regulus of antimony, was likewise known to the
ancients; but it was not until the fifteenth century that the metal was
extracted from the ore by Basil Valentine and called antimony. The
learned monk gives the following process of reduction: "Take of the
best Hungarian antimony [meaning the sulphide] and crude tartar [i.e.,
cream of tartar or crust of wine] equal parts, and of salt nitre half a
part; grind them well together, and afterwards flux them in a wind
furnace; pour out the flowing matter into a cone, and then let it cool;
then you will find the regulus; which thrice, or oftener, purge by fire
with tartar and nitre, and it will be bright and white, shining like
cupellate silver, which hath fulminated [alluding to the brightening up
of the silver on the cupel when the process is complete] and overcome
all its lead." We have only to complete this process with the method
of purification recommended by Dr. Thomson-viz., pounding the crude
metal, mixing it with its own weight of antimonic acid, and fusing in
a crucible, and the antimony is obtained in a state of purity. Native
antimony, containing about 98 per cent. of the_metal, is found in the
gneiss mountains of Chalanches in Dauphiny in France.
White antimony ore, red ore, or oxide of antimony, is likewise found
in moderate quantities in Bohemia, Saxony, and Hungary; but the
most important ore containing this metal is the "radiated grey anti-
mony" ore, the tersulphide of antimony (SbS,), consisting of 72-8
antimony and 27.2 sulphur. It occurs in Scotland, Cornwall, Norway,
Saxony, Bohemia, Hungary; and hence the title given to it by Basil
Valentine of Hungarian antimony. The reduction of this metal from
the ore is conducted, on the large scale, with a reverberatory furnace
provided with a sloping hearth; the heat fuses the tersulphide, which
flows away from the earthy matters, to the lower part of the hearth into
proper vessels placed to receive it. The tersulphide is then roasted,
converted into an oxysulphide, or glass of antimony, and finally reduced
with charcoal and carbonate of soda.
One of the best modes of assaying the sulphide is to fuse it with cyanide
of potassium, by Mitchell's method, in which he employs one part ore and
four of cyanide of potassium; the heat required is so very low that
little, if any antimony, is lost by sublimation. Antimony, when pure,
has a silver-white colour and much brilliancy. Basil Valentine, whilst
* Worcester, in his new "Dictionary," says that avri, against, and μovos, one or alone,
mean, when combined as in antimony, a metal seldom found alone. See p. 152 (table).

RE
418
ANTIMONY.
describing the reduction of the ore to the metallic state, says, “You
will obtain a fair star, (*) bright and shining like cupellate silver."
Antimony is partly fibrous, or rather made up of a number of very
fine plates; it crystallizes in the octohedral form, and being very brittle,
is easily reduced to powder. The specific gravity of antimony is 6.702,
and it melts at about 800° Fahrenheit, and although it does not vola-
tilize so readily as zinc, still it assumes the state of vapour at high
temperatures.
EXPERIMENTS WITH ANTIMONY.
First Series.
A globule of melted antimony thrown down from a height of about
two feet on to the centre of a levelled sheet of cartridge paper, exhibits
the most eccentric movements, dividing itself into numberless minute
beads, which bound and rebound over the surface of the paper, leaving
a track of oxide, and burning at the same time with considerable bril-
liancy. Mr. G. Gore, the talented electro-metallurgist of Birmingham,
has discovered that there are peculiar modifications of metallic antimony
obtainable by electro-deposit, which he terms amorphous and crystalline,
dark and grey. For the special production of the dark amorphous anti-
mony, he employs a solution composed of the ordinary chloride of anti-
mony saturated with tartar emetic, using about three or four parts of
the former to one of the latter; and for the precipitate of the crystalline
grey antimony, a solution is made of five parts tartar emetic, five parts
tartaric acid, dissolved in a mixture of ten parts of hydrochloric acid
and thirty parts of water, each solution being filtered before using.
To prepare Gore's amorphous antimony, take any quantity, say, for
the sake of convenience, ten ounces by measure (i.e., half a pint) of
pure hydrochloric acid; add to it as much as it will dissolve of oxide
of antimony (this will be about two and a half or three ounces by
weight, if the acid is of the usual strength), and then add about five or
six ounces more of the pure acid, and well stir the mixture. Pulverized
tartar emetic may be substituted for the oxide of antimony with but
little disadvantage. Prepare a small voltaic battery of about two pairs
of plates; connect a piece of the purest commercial quality of antimony
(known as "best French regulus") with the positive pole of the bat-
tery, and suspend it in the solution, so that the connecting wire is not
in contact with the liquid, and connect a polished and clean sheet of
thin sheet silver or copper with the negative pole of the battery, and
immerse it also vertically in the liquid at about two or three inches dis-
tance from the antimony, taking care to have about as large a surface of
silver or copper in contact with the liquid as of antimony. The sheet
of metal will immediately acquire a nearly black shining coating of
"amorphous antimony," which goes on increasing in thickness as long
as the power of the battery continues. The process should be continued
until the coating is about one-twelfth or one-sixteenth of an inch thick
on each side of the sheet; this will occupy about three days and nights,
GORE'S AMORPHOUS ANTIMONY.
419
if the battery is moderately strong. The solution should be stirred
with a rod of gutta-percha or glass every morning and evening during
the action.
When the deposit is sufficiently thick, transfer the coated sheet to a
wooden bowl into which a stream of cold water is freely running, and
clean the metal (which will become covered with a white powder) by
means of a soft brush; bend the sheet of metal very slowly and
cautiously under the surface of the water, the "amorphous antimony"
will then fall off in large plates, which should be at once removed and
broken upon a surface of wood, under cold water, into fragments of the
desired size, by a gentle blow with the end of a wooden rod; the frag-
ments should then be wiped dry and placed at short distances asunder
upon a narrow strip of cotton wool, which may then be formed into a
roll and kept for many months, and conveyed with safety.
The peculiar property of this substance is, that it evolves a large
amount of heat by slight causes, such as friction, a blow, momentary
contact of a heated wire, a flame, &c.; and that the heat evolved is not
due to cohesive action, nor to alteration of the specific heat of the
substance. The temperature at which the sudden discharge occurs
varies from 170° to upwards of 212° Fah. The total amount of
heat evolved by electro-deposited antimony is usually sufficient to raise
the temperature of an equal weight of ordinary antimony about 650°
Fah. The evolution of the vapour of terchloride of antimony is
not a cause, but an effect of the heat. The active substance consists of
about 93.5 per cent. of antimony, 6·0 per cent. of terchloride of anti-
mony, 0.3 per cent. of hydrochloric acid, and a trace of water. It is
also liable to contain traces of nearly all the impurities of the anode
and of the depositing liquid. The discharge of heat is always attended
by a diminution of attraction between the metal and its associated ter-
chloride of antimony. The terchloride of antimony cannot apparently
be extracted without destroying the heating property of the substance,
and by lapse of time the active substance invariably loses its heating
power, especially if it is in a state of mixed division.
Much amusement has on many occasions been produced at juvenile
parties, soirées, &c., by taking a number of small fragments of the sub-
stance, about one-sixteenth or one-twelfth of an inch thick, and about
three-eighths or half an inch square, handing them round in single
pieces to persons with a request to hold it very firmly between the finger
and thumb of the left hand, and rub it quite hard with the edge of a new
sixpence or other rough and hard body; it then quickly evolves so much
heat as to adhere rather strongly to the fingers, and much amusement is
created by the violent movements exerted to get rid of it. If the sub-
tance is very cold, or if it has been prepared many months, it does not
readily act; it should in that case be made warm and rubbed imme-
diately. After a fragment has once evolved its heat it is valueless, as it
does not evolve heat a second time. A mass of the substance of half
an inch or three-eighths of an inch thick evolves sufficient heat to melt
tin and other metals. The amount of heat evolved by one ounce of the
EE 2
420
ANTIMONY.
substance has been found by actual measurement to be sufficient to
raise the temperature of one ounce of common antimony from 50° Fah.
to 700° Fah., that is, 650°; but no flame or actual ignition of paper,
cloth, wood, &c., is produced in any instance.
It has been exhibited by Dr. Tyndall before the Royal Society; and
a full account of its properties is published in the Philosophical Trans-
actions of that body for the year 1858.
The substance has not at present been applied to any useful or manu-
facturing purpose, although the cost of producing it upon a large scale
would be comparatively small.
Second Series.
To produce the crystalline antimony, prepare some of the second liquid
already described, and proceed in the same manner as for the produc-
tion of the amorphous antimony, except that a much larger receiving
surface should be used in consequence of the greater tendency to a
sandy deposit. In this case the deposit is grey, and frequently of a
dull aspect, or even a dark, loose, granular powder, if the power is too
great; but when properly produced, it has a silky lustre or semi-
iridescent silver-grey appearance, especially when viewed within the
liquid; and if the process is continued for several days, or better, for
one week, the edges of the deposit assume a partly nodular form. The
cleaning of the anode in this case may be of less frequency and with
water alone.
Antimony trees, consisting of branches of amorphous and crystalline
nodules, are easily formed by suspending a horizontal copper wire as a
cathode, upon the surface of the terchloride solution.
The fracture of amorphous antimony is conchoidal, smooth, and
waxy; that of the grey variety is crystalline, radiating like hematite.
The texture of the amorphous variety is rather soft and weak, that of
the crystalline quite hard and strong; the former files easily, the latter
with more difficulty.
Third Series.
The combining equivalent of antimony is 129, and it unites with
oxygen in at least three proportions, viz. :—
1. The suboxide of antimony
2. The teroxide of antimony
3. Antimonic acid
•
Sb₂04.
SbO
3.
Sbog.
The first oxide constitutes what may be termed the rust of antimony,
or the film which gradually forms on the surface of the brilliant metal.
The second, the teroxide, is the important oxide which is contained in
that valuable medicine called tartar emetic, the tartrate of antimony
and potash, KO,SbO,,T+Aq. The teroxide is obtained by heating
antimony at a tolerably high temperature in an open vessel, when it
sublimes as a white vapour, which condenses, and collected constitutes
a white oxide formerly called argentine flowers of antimony. Basil
Valentine, speaking of its preparation, says: "Some have peculiar in-
EXPERIMENTS WITH ANTIMONY.
•
•
•
421
struments for this work, prepared with windy caverns through which
the antimony may receive the air, and be sublimed.
But the pro-
cess by which I inake the flowers of antimony most profitable for medi-
cine is this: I mixed the red flowers of antimony with colcothar of
vitriol-i.e., red oxide of iron, and sublimed them together thrice." The
next cut shows a convenient method of preparing the teroxide of
antimony.
いいいい
​N
ฟ
N
-
B
وائے الا



Z
N
Fig. 226. Preparation of the Anhydrous Teroxide of Antimony. A. Lower
erucible standing on a brick in the furnace z z z z, and containing the melted
antimony B, which, being gradually oxidized, forms the teroxide; and this latter
sublimes into the upper inverted crucible, with hole in bottom, c, and condenses
at D in needle-shaped crystals.
Antimonic acid is obtained by dissolving antimony in aqua regia,
evaporating the solution to dryness, adding nitric acid to the residue,
and heating it till all the nitric acid is expelled; it combines with
potash, soda, ammonia, and also with the teroxide of antimony.
"James's powder," identical with pulvis antimonialis, is a mixture of
fifty-seven parts of impure teroxide of antimony and forty-three of
phosphate of lime.
Fourth Series.
Chlorine, iodine, bromine, and fluorine all unite with antimony. Of
these combinations the most interesting is, perhaps, that peculiar fatty
greyish-white product obtained by distilling a mixture of two parts cor-
rosive sublimate and one of powdered antimony. This substance was for-
merly called the "butter of antimony," and is a terchloride of the metal.
422
ANTIMONY.
Finely-powdered antimony dropped into a bottle of dry chlorine
takes fire and produces the same product.
Fifth Series.
Hydrogen unites with antimony most probably in the ratio of the
formula SbH,. Antimoniuretted hydrogen is produced by pouring a
solution of antimony into a vessel containing the usual materials for
generating hydrogen gas-viz., granulated zinc and pure dilute sul-
phuric acid; the gas burns with a peculiar coloured flame, and if a white
porcelain dish or piece of window glass is held above it, a bright me-
tallic stain of antimony is deposited which may be mistaken for arsenic,
but is easily distinguished by adding some strong nitric acid, and eva-
porating to dryness; on the addition of a little distilled water and a drop
or two of a solution of nitrate of silver, a dirty-white precipitate is
obtained, perfectly different from the brick-red one obtained when the
arsenic stain is treated in a similar manner. Moreover, the antimony
stain is insoluble in a solution of chloride of lime, which readily dis-
solves the arsenic mirror or stain.
Sixth Series.
The tests for the metal antimony afford the most unmistakeable
results.
Sulphuretted hydrogen precipitates from solutions of the teroxide,
such as tartar emetic, an orange-red precipitate of the hydrated tersul-
phide of antimony, SbS,HO, both in acid and neutral solutions. If the
solution is very dilute and neutral, it merely changes to a red colour, but
the precipitate falls on the addition of some hydrochloric acid. Potash,
soda, and ammonia throw down bulky white precipitates of the hydrated
teroxide of antimony soluble in an excess of the reagents.
Tincture of galls affords a white precipitate with solutions of
antimony.
The tersulphide of antimony dissolves in boiling hydrochloric acid,
with the evolution of sulphuretted hydrogen; and if the solution is
poured into a large test glass containing distilled water, a dense white
precipitate is formed of the oxychloride of antimony, called the
"powder of algaroth," SbCl₂,2 SbO₂HO, soluble in tartaric acid.
Seventh Series.
The alloys of antimony are very important, and amongst them may be
noticed “Britannia metal," composed of 100 parts of tin, 8 of anti-
mony, 2 of bismuth, and 2 of copper; but the special alloy of this
metal is, with lead, called "type metal," and composed of 4 parts of
lead and 1 of antimony. Its hardness is such as to resist without
breaking and bending the sudden pressure of the printing press. It
TYPE METAL.
423
would be impossible to state briefly the wonderful agency of this human
invention, which is gradually spreading knowledge in all languages to
nearly every nation and people of the earth. The daily and weekly
'press" of the United Kingdom, taken as a single example of the work
of the "printing press," exhibits an irresistible power which is the
marvel and praise of the whole civilized world.
cre

-TIMES.
Fig. 227. Times Printing Office, Publishing Hour.

Fig. 228. The Trial of Madame Laffarge.
CHAPTER XIII.
ARSENIC.
IF the old alchemists had been aware that this metal would have been
made the instrument of so many crimes amongst high and low of all
degrees, they would probably have represented it by the sign of the
"death's head and cross bones." Arsenic, like alcohol, is one of the
good things which were created for man's use and profit, but it has
been fearfully and wickedly abused.
The learned Dr. Thomson states that the word arsenic (apoeviKOV,
powerful) occurs first in the works of Dioscorides, and some other
authors who wrote about the beginning of the Christian cra. It denotes
in their works the same substance which Aristotle had called oavdapaɣn,
and his disciple, Theophrastus, appevɩkov, which is a reddish-coloured
mineral, composed of arsenic and sulphur, used by the ancients in
PROPERTIES OF ARSENIC.
425
painting, and as a medicine. The white oxide of arsenic, or what is
known in commerce by the name of arsenic, is mentioned by Avicenna,
in the eleventh century; but at what period the metal called arsenic was
first extracted from that oxide is unknown. Paracelsus seems to have
known it, but the metal does not appear to have been obtained as a simple
or single body until Brandt, in 1733, described an accurate process for
procuring it.
Arsenic occurs as a metal and mineralized in nature, and the following
minerals are well known :
Name.
Native arsenic.
Oxide of arsenic
Red orpiment, or realgar,
Yellow orpiment
Common arsenical pyrites
Pharmacolite
•
S
·
Arsenic.
Composition.
Oxygen and arsenic.
Sulphur and arsenic.
Arsenic, sulphur, iron.
Arsenic acid, lime, water, with sometimes
magnesia and oxide of cobalt.
gas,
The oxide of arsenic, or arsenious acid, is obtained as a secondary
product from the roasting of certain minerals, such as arsenical pyrites,
cobalt, tin, copper and lead ores. They are placed on the hearth or
sole of a reverberatory furnace, to which an abundance of heated air
(coming through the grate) is admitted. The oxygen of the air com-
bines with the sulphur of the mineral, and forms sulphurous acid
which flics up the chimney, and is thus wasted and lost; whilst the
combination of arsenic and oxygen-viz., arsenious acid-condenses in
cells, chambers, or flues through which the air from the reverberatory
furnace must pass before it finally escapes into the atmosphere. The
crude white arsenic is then re-sublimed, not in expensive glass vessels
or alembics, but in cast-iron tubes or retorts fitted to wrought-iron
receivers. The author has seen masses of re-sublimed white arsenic
which have appeared more like porcelain than arsenious acid; and,
indeed, this substance is employed to impart the appearance of
porcelain to glass. The metal arsenic can be procured by heating
the oxide with black flux, and when deposited on the inner surface
of a glass tube, presents a most perfect brilliancy called the "arsenic
mirror," to which special allusion will be made in the experiments
with this metal. Arsenic has a steel-grey colour, is extremely
brittle, and when carefully sublimed, assumes a very perfect
crystalline form-viz., that of brilliant rhombohedral crystals. The
specific gravity of arsenic is 5.75. One of the most important uses of
the metal is for the purpose of conferring a perfect spherical figure to
the melted lead as it falls through the colander placed at the summit of
the lofty shot towers which rear their heads in the neighbourhood of
Waterloo Bridge and elsewhere. If too much arsenic is added, the
shots have a double-convex form, but are not spherical; and when too
small a quantity has been alloyed with the lead, the drops are pear-
426
ARSENIC.
>>
-་་༥ཡ
shaped, and some practice is required to adjust the precise quantity of
arsenic, which not only confers a spherical figure, but likewise hardens
the lead considerably. Arsenic is likewise used to whiten copper, and
small quantities are employed in casting the specula for telescopes.

11
Fig. 229. Shot-Tower, near Waterloo Bridge.
POISONED SWEETS.
EXPERIMENTS WITH ARSENIC.
First Series.
427
The combining equivalent of arsenic is 75, and it unites with oxygen
in two proportions, forming-
Arsenious acid, or white arsenic
Arsenic acid.
AsO₂.
ASOS.
White arsenic is readily prepared from metallic arsenic, by subliming
a small quantity of the metal through a glass tube open at both ends.
After chasing it about slowly with the flame of a spirit lamp, it is
converted into perfect octohedra (like alum) of arsenious acid.
Arsenious acid is readily converted into arsenic acid by digesting it
with nitric acid mixed with a small quantity of hydrochloric acid, and
evaporating to dryness, and heating till all the excess of acid is driven
off.
Second Series.
Powdered metallic arsenic, brought in contact with chlorine gas, by
sprinkling it into a bottle containing that element, takes fire, and pro-
duces a chloride of arsenic. A definite terchloride (AsCl₂) is prepared
by distilling arsenic with corrosive sublimate; but very great caution
must be used in experiments with this metal, to avoid inhaling any of
the fumes from these preparations.
Third Series.
Sulphur forms no less than five compounds with arsenic, of which
the most remarkable are realgar, or red orpiment (AsS,); a bisulphide
of arsenic; and yellow orpiment, or king's yellow, a tersulphide of
arsenic (AsS,). The latter is easily made, either by distilling white
arsenic with sulphur, or by precipitating a solution of arsenious acid
with sulphuretted hydrogen, with the addition of a little hydrochloric
acid. This hydrated tersulphide is soluble in nitric acid and ammonia.
Before the exposures which took place under the supervision of Dr.
Hassall and the Sanitary Commission of "The Lancet," great careless-
ness was observable in the colouring of twelfth-cake ornaments and
other things which might come into the hands of children; and there
can be no doubt that the preparations of arsenic have performed their
fatal mission, in times now happily gone by, and many a child has pro-
bably been hurried into eternity by some of the vile trash called
"sweets" coloured with poisonous metallic preparations to make them
more attractive. Orpiment especially was a favourite colouring material,
equalled, if not surpassed, in popularity by the lovely green produced
by precipitating a solution of sulphate of copper with one of arsenious
acid, to which carbonate of potash has been added. This colour is
called "Scheele's green," and is an arsenite of copper, consisting of
two equivalents of oxide of copper united to one of arsenious acid. It
428
ARSENIC.
is also prepared by adding a solution of the ammonio-sulphate of
copper to one of arsenious acid.
Fourth Series.
There is unhappily no metal whose reactions with other bodies have
been so carefully studied as those of arsenic, or rather white arsenic,
that being the poison supposed to have been used by the infamous
Tophania or Toffana, who resided first at Palermo, and afterwards at
Naples; this wretch, who was put to the rack, and afterwards strangled,
confessed to having caused the death of not less than six hundred
persons. This disgrace to her sex was succeeded, as arsenical poisoner-
in-chief, by another woman, if anything, even more infamous and
satanic, the Marchioness de Brinvilliers, who was at last condemned
and executed at Paris, being first beheaded and then burnt, on the 16th
of July, 1676.
In the nineteenth century the succession of the evil name of arsenical
poisoner passed, by universal consent and execration, to Madame
Laffarge, who managed to escape death by the sentiment she artfully
provoked in her judges and the public, but who was reserved, perhaps, for
worse than death-viz., the slow but sure action of conscience and the
stern, unrelenting discipline of a French criminal prison. Great numbers
of male arsenical poisoners have equalled, if not surpassed, in indi-
vidual acts of deep-laid villany, the accumulated tragedies of a
Toffana or a Brinvilliers; but it is strange that in the early days of
these dark deeds that women should have gained such an unenviable
notoriety in that respect. It seems that we do not now require pro-
fessional poison-makers, as arsenic is brought within the reach of any
one, and Mr. Draper has found an average of 2.55 grains of arsenic (quite
enough to destroy life) in each of the papier-Moure fly-papers. Hence
they might lead to the accidental poisoning of children, or serve the
purpose of criminals.
Marsh's Test is a most convenient preliminary one, on account of its being
so easily and quickly applied; but it is not absolutely relied on, because
antimony affords the same kind of result, and where the two poisons may
exist together, neither could be detected with certainty; its value con-
sists in proving at once the presence or absence of arsenic or antimony.
It may be arranged in an expeditious manner, by passing a tobacco-pipe
through a cork fitted into a perfectly clean bottle containing some zinc
and dilute sulphuric acid, both of which it is, perhaps, needless to state,
must be free from arsenic. When the hydrogen is being freely evolved,
a little of the fluid suspected to contain arsenic may first be boiled in a
test tube, to coagulate any matters which are affected by a temperature
of 2120, and then poured into the bottle containing the zinc and acid.
The escaping hydrogen is now set on fire, and a piece of white hard
porcelain or a clean white plate held close over the end of the tobacco-
pipe, so as to cut the flame in half; if any arsenic or antimony are
present, they are deposited on the porcelain as a dark, metallic, and
shining mirror, which, when once seen, is unmistakeable. A little nitric
DETECTION OF ARSENIC.
429

acid is now dropped on the stain, and the
porcelain heated, and the plate is put into
the oven; when the excess of acid is eva-
porated, a few drops of water are added,
and the solution tested with one of nitrate
of silver, with (if required) a few drops
of dilute ammonia, when a brick-red pre-
cipitate of arseniate of silver, soluble in
nitric acid and ammonia, is obtained. If
the stain be antimony, the precipitate with
nitrate of silver is dirty-white, quite
different from that of arsenic. When the
hydrogen is burning, a number of stains
or "mirrors" may be taken on separate
bits of glass or porcelain, or on different
parts of the plate; and if a beaker glass
is held above the burning gas, containing
the arseniuretted hydrogen, the arsenic is
oxidized and converted into white arsenic,
which deposits in the glass, and, being dis-
solved with boiling distilled water, will af-
ford a yellow precipitate of arsenite of silver
with Hume's test (viz., the ammonio-nitrate
of silver, which must be free from excess of
ammonia), or Scheele's green with neutral
solution of ammonio-sulphate of copper.
Both of these tests are best applied by
first adding either the solution of silver or
copper separately, and then taking a stirring
rod moistened with ammonia, and holding
it at the top, and just touching the solu-
tion supposed to contain the white arsenic,
when the precipitate of yellow arsenite of
silver or green arsenite of copper falls in
a very distinct manner. There are more
refined methods of applying Marsh's test; Fig. 230. Marsh's Test. ▲. Bottle
but, as the youthful readers of this book containing zinc and dilute sul-
are not likely to be engaged in medico- phuric acid and the suspected fluid.
legal inquiries, enough has been said to pipe fitted through cork, and having
enable the experimentalist to detect arsenic some clean, dry cotton-wool, C,
lightly tied at the bottom of the
in a mineral, which of course must first be cork, to stop the moisture which
dissolved in an acid.
C
B
B. Cork and tube, or clean tobacco-
condenses in the pipe and spoils the
experiment. D. Plate covered with
Reinsch's test is the one now preferred black stains of arsenie; in one or
by toxicologists, and consists in the use of two seconds an arsenic mirror is
copper wire-gauze rendered chemically obtained, and if the plate is held
over the flame for a longer time, the
clean by dipping it into strong nitric acid indication may be lost.
and washing thoroughly with water. The
suspected fluid is rendered acid by hydrochloric acid,-if nitric and chloric
430
ARSENIC.
acids (chlorate of potash, for instance) are present, they should first be
got rid of—and then boiled for ten minutes with the clean copper gauze.
If a film deposits, the gauze should be withdrawn, and another piece
put in, as any number of pieces of wire gauze can be kept clean and
ready for use by attaching them to a suspending thin copper wire, dip-
ping them in nitric acid, washing, and leaving the gauze under pure
water. The ganze taken out of the liquid under examination is now
well washed with water and carefully dried, it is then placed in a clean,
hard German glass tube of a small diameter, certainly not wider than
two-eighths of an inch, and the heat of a spirit lamp gradually applied
to the place where the wire gauze is resting, and the tube slightly in-
clined upwards. By this manipulation a current of air oxidizes the
metallic arsenic as it is sublimed from the surface of the gauze, and
forms white arsenic, which condenses in the further end of the tube, and
may be washed out afterwards with boiling water and tested by the
reagents already named.
The following remarks on arsenic sublimates, made by Frederick W.
Griffin, Ph.D., of Bristol, are so important, that we give them entire :
"While acknowledging the ingenious character of many of Dr. Guy's
adaptations, as described in his paper read before the Society of Arts, I
must altogether demur to the proposed employment of flat discs of glass
for receiving arsenical crusts. Except with very high magnifying
powers (which are rendered unnecessary by adopting a process which I
shall presently describe), a glass tube of half an inch diameter offers
equal facilities for examination under the microscope. Indeed, for small
crystals, even a quarter-inch objective (magnifying 500 diameters) can
be so employed, with the slight drawback of needing some extra focus-
ing. On the other hand, the rapid sublimation required in Dr. Guy's
method must involve the loss of part of the arsenical vapour at the mouth
of the tube, which is only loosely covered by the flat glass; and another
portion, being very dense, will remain in the tube itself, whilst that
which reaches the disc will be deposited on it in a nearly amorphous
condition. No wonder that such 'mists' should frequently require ob-
jectives of one-eighth inch to develope any crystallic character, and even
then a few imperfect triangular facets afford but unsatisfactory evidence
of octohedralism when we consider what weighty issues are in a measure
dependent on the making out that feature. It is, however, in the
power of the operator to obtain crystals of arsenious acid as perfect as
he can those of alum an inch or two in diameter, and by acting on the
same principle, namely, by obtaining a very gradual formation during
slow cooling. The following is the modus operandi, as described in
Table I. of my Compendium of Qualitative Analysis. Drive the sub-
stance entirely off the lower half of the tube, which is made very hot by
waving it about in the flame. Then revaporize the sublimate, holding
the tube (which should be closed by a loosely-fitting cork) as upright as
possible. The dense vapour sinks to the bottom, and will give farge and
regular crystals as the glass slowly cools. These crystals glitter in the
sun like diamonds, and exhibit the same play of colours: they are from
50
EXPERIMENTS WITH ARSENIC.
431
th toth of an inch in diameter, and under an inch objective form
splendid specimens for the micro-crystallographer. Here and there we
find octohedra absolutely perfect, but they are more frequently truncated;
all the angles, however, being beautifully sharp. The majority are
transparent, but some are only translucent, or even opaque. By re-
flected light (using a bull's-eye condenser) they appear, in consequence
of their adamantine lustre, like diamonds lying in high relief on a black
ground; but their complete shape is most strikingly displayed by a
combination of strong reflected and feebler transmitted rays of various
degrees of obliquity. A tube of half an inch diameter, under a one-inch
objective, presents nearly the entire field in focus, and the perfect
crystals appear from one-half to three-quarters of an inch in diameter.
As regards the statement that arsenious acid sometimes assumes the
cubic form, I would venture to suggest that Dr. Guy may possibly have
been deceived by a hasty examination. An octohedron, if opaque and
seen only by transmitted light, often appears a cube, since, when viewed
perpendicularly to either axis, its section or outline is square. I may
mention as a parallel case, that I have obtained crystals of hydrate of
chlorine full a tenth of an inch in diameter, which, for the most part,
seemed to be perfect rhombs (the angles were 110° and 70°), but closer
observation convinced me that Faraday's description of them as acute
flattened octohedra with three unequal axes' (ie. rhombic_octohedra)
was really correct. Such misapprehensions are very likely to occur
under high magnifying powers.
1
1000
"I will describe an actual experiment which will show that my
method is as applicable to minute quantities as Dr. Guy's, while it is far
more conclusive in its results. Dr. Guy states that th of a grain
of arsenious acid yielded on sublimation a circular mist consisting of
brilliant detached points distributed evenly over the surface (of a disc),
and easily resolved into octohedra under an eighth power of the micro-
scope.' By way of comparison, I accurately weighed out a grain of
pure arsenious acid on a balance sensible to the thousandth of a grain.
I dissolved this in water, and made up to a known bulk. By means of
a graduated pipette I took a thousanth part of this, containing, of
course, a thousandth part of a grain of arsenious acid, and evaporated it
to dryness on a bit of curved glass. The latter, with the slight residue
adhering to it, was then cut up and placed in a corked tube four inches
long by four-tenths of an inch in diameter. On igniting the fragments,
a feeble sublimate appeared half way up the tube, which, under a
quarter-inch objective, was seen to consist of granules, evidently crystal-
line, but of indeterminable shape, and not more than 100th of an inch
in size.
Resublimed by my method, these gave a few octohedra, which
were sought out by the inch objective, and then examined under the
quarter-inch. They were beautifully perfect in shape, and about th
of an inch in diameter. This alone would yield the strongest presump-
tive evidence of the nature of the substance in question, but I can by no
means agree with one of the speakers at the meeting (Dr. Thudichum),
who considered that we might afford to neglect applying the liquid tests
1
1200
432
ARSENIC.
to a solution of the sublimate. Each reaction must stand for what it
is worth, but the concurrence of many furnishes proof the most irre-
fragible. The above quantity seems to be about the smallest that would
yield any definite result in a tube of the size named; but unless much
more than a thousandth of a grain of arsenious acid were obtained by
Reinsch's tests, I, for one, should be extremely loth to assert that it
had been criminally administered. Indeed, I fear that the detection of
this particular poison has reached an almost dangerous degree of deli-
cacy, for we live surrounded by means of unconsciously absorbing traces
of arsenic. We breathe arsenicated dust from the green flock papers on
our walls; arsenical papier-Moure lies soaking on dishes afterwards
used for culinary purpose; arsenic is contained in glazed green papers
which are often employed for wrapping cocoa and other articles of food,
and confectioners supply it wholesale in their cake-ornaments. The
very drugs prescribed for our relief, especially the compounds of bismuth,
are tainted with arsenic, and it has even been detected in carbonate of
soda. Nay, more, our vegetable food, as Professor Davy has lately
pointed out, may be contaminated with arsenic derived from superphos-
phate-manure, and there is probably no drinking-water containing iron
without a trace of arsenic as well. Now, metals are remarkably prone
to become localized in particular organs; the 'dropped joints' of painters
are found to contain lead permanently combined with the tissue; and a
course of iodide of potassium will bring off abundance of mercury by the
urine, years after its administration. It would appear by no means
improbable that traces of arsenic occasionally introduced into the
system, may be stored up in like manner (especially in the liver), till, in
the course of years, the amount becomes appreciable. Many aquatic
plants contain much iodine, all gradually absorbed from the water in
which they live, though it cannot be detected therein, from the minute-
ness of its quantity; the vegetable tissue, however, accumulates it and
retains it persistently. So may it be with arsenic in the human body;
and I think toxicologists should pause before affirming that it had been
criminally administered, unless a proportionate amount of the poison is
found."
Sulphuretted hydrogen throws down orpiment in solutions of white
arsenic, provided a few drops of hydrochloric acid are added, and this,
taken in conjunction with the nitrate of silver test, is greatly to be
relied on.
Before dismissing the subject of white arsenic, it may be stated that
it is employed for very many useful purposes-viz., in the manufacture
of glass and enamel, and also for destroying vermin, and for other
purposes in the treatment of sheep.
The strangest story in connexion with this poison is the fact attested
by the most truthful evidence, obtained by Mr. Heisch, the eminent
Professor of Chemistry at the Middlesex Hospital School-viz., that the
peasants and other persons in Germany, and especially in the metallur-
gical districts of Styria, actually eat small doses of white arsenic to improve
their personal appearance, and also to increase their powers of sus-
THE ARSENIC-EATERS.
433
taining fatigue in the ascent of this romantic Alpine region. Amongst
the evidence adduced are the following statements: There is in
Stürzburg a well-known arsenic eater, Mr. Schmid, who now takes daily
twelve and sometimes fifteen grains of arsenic. He began taking arsenic
from curiosity, and appears very healthy, but always becomes sickly and
falls away if he attempts to leave it off." They say, "In this part of
the world, when a graveyard is full, it is shut up for about twelve years,
when all the graves which are not private property are purchased and
dug up, the bones collected in the charnel-house, the ground ploughed
over, and burying begins again. On these occasions the bodies of
arsenic-eaters are found almost unchanged and recognisable by their
friends." Many people suppose that the finding of their bodies is the
origin of the story of the "Vampire."

Fig. 231. Arsenic-eaters of Styria.

WA
Fig. 232. Use of Nitrate of Baryta, mixed with Sulphur and Charcoal, for the Green
Fire of the Ghost Scene.
CHAPTER XIV.
BARIUM.
AMONGST the host of new metals with which Sir H. Davy surprised the
scientific world at the beginning of the nineteenth century was the
metal barium, so called from the Greek Bapùs, heavy, because of its
existence in a very common mineral that occurs in veins, and rocks of all
ages, called "
heavy spar," consisting of sulphuric acid and the oxide
of barium or baryta, and termed sulphate of baryta. This mineral is
used extensively for the purpose of mixing with white lead; we must not,
perhaps, call it adulteration at a certain commercial stage, because the
wholesale people know perfectly well what they are about when they
EXPERIMENTS WITH BARIUM.
435
buy white lead mixed with ground heavy spar, or still better, with heavy
white, which is the same substance prepared artificially, and, therefore,
much whiter and freer from earthy matter or oxide of iron, which im-
parts a yellow tinge to the pigment. The adulteration is only felt by
Paterfamilias, who, innocently thinking to do a little economical paint-
ing (house) on his own account, buys some white lead, and is much dis-
gusted to find that it soon washes off again, after a few vigorous ap-
plications of the domestic soap and water; moreover, a larger quantity
of the adulterated than the pure white lead is required to cover a given
surface properly. Analysis reveals all these delinquencies, and in the
Government dockyards and arsenals white lead is not purchased until
an analysis of the sample has been made. The heavy white is usually
made from the carbonate of baryta, called by mineralogists "witherite,"
and found in large quantities in Lancashire, Northumberland, and Cum-
berland, and used to destroy vermin. In the localities where the car-
bonate of baryta occurs, the poultry frequently and innocently commit
suicide by swallowing the poisonous mineral in mistake for chalk, and,
therefore, must be kept shut up, at least from all access to the public
roads along which cartloads of the mineral are conveyed.
The metal can be obtained by Davy's original process-viz., electro-
lizing carbonate of baryta in conjunction with mercury by a very
powerful voltaic battery; the metal is eliminated in small quantities and
amalgamates with the mercury; by subsequent distillation the latter is
driven off, and the barium remains in the tube or retort. It is, how-
ever, more expeditiously obtained by subjecting baryta, on dense gas
graphite charcoal, to the action of the oxy-hydrogen jet in which an
excess of hydrogen is maintained.
After our experience of the actual properties of aluminium as com-
pared with book statements, it is not surprising to find Dr. Matthiessen
assert that barium powder has a yellow colour, decomposes water at
ordinary temperatures, and oxidizes quickly when exposed to the
atmosphere; whereas other authors assert that it is white, brilliant,
and malleable.
EXPERIMENTS WITH BARIUM.
First Series.
The equivalent of barium is 68.5, and it unites with oxygen in two
proportions-viz. :—
•
Baryta
Binoxide of barium.
BaO
BaO2
Baryta is made by calcining the nitrate of baryta in a covered and
capacious iron crucible, at a full red heat, until no more fumes escape.
It is a grey cellular mass, and must be kept from contact with the air,
as it soon "slacks like lime, and, combining with water, changes to
a white dust or hydrate of baryta.
When water is dropped upon
it, enough heat is evolved to fire gun cotton or phosphorus.
FF 2
436
BARIUM.
Barium, placed in water, decomposes the latter, unites with its oxygen,
and forms baryta, which is dissolved, whilst the hydrogen escapes with
effervescence. A solution of baryta in water is used as a test, and
called baryta water; it must be kept in a well-closed bottle, as it pos-
sesses a remarkable affinity for carbonic acid. The carbonate of baryta
dissolved in dilute nitric acid, forms nitrate of baryta, being the salt
which is used so effectively in pyrotechnic compositions and at theatres
to produce the livid colour on the "ghost; "the effect is, no doubt,
very startling, unless an officious current of air should waft a strong
draught of sulphurous acid (the supposed diet of such unfortunates)
from the burning "green fire," and make the poor ghost sneeze.
The binoxide of barium is made by passing oxygen over baryta
heated to a dull red heat, and Boussingault has indicated this substance
to be a steady source of oxygen gas, as it can be made to absorb and
deliver up its oxygen with the assistance of steam. The process de-
serves more attention than has hitherto been paid to it, because the
oxygen so procured is taken from the air, and the only cost is for the
baryta; there are, however, certain difficulties of manipulation, which
render the process uncertain in the hands of ordinary work-people.
Second Series.
M. Thenard's method of preparing the pure peroxide of barium is as
follows: "First make a pure nitrate of baryta, and give it a strong heat
in a porcelain vessel, by which baryta, not quite pure, but containing
traces of silica and alumina, but no manganese, will be obtained; the
latter impurity must always be most cautiously avoided, for oxide of
manganese possesses the property of energetically decomposing the
oxygenated water. The baryta, broken into small pieces, is then intro-
duced into a luted glass tube (the glass should not contain lead) large
enough to contain about two pounds of it, and being heated to dull
redness, a current of dry and perfectly pure oxygen gas is passed through,
which it rapidly absorbs; this operation is to be continued till the
oxygen escapes from a small tube inserted into the opposite extremity
of the larger one. The peroxide of barium thus obtained is pale grey,
and frequently some pieces are speckled with green, which announces
the presence of manganese, and these portions should be rejected; its
distinctive character is that it crumbles when a few drops of water are
added to it, without producing heat."
It is from this substance that the so-called peroxide of hydrogen, or
oxygenated water (HO,), is obtained, which is colourless and inodorous.
It blisters the cuticle of the tongue, and has a peculiar metallic taste.
It is decomposed by all metals except iron, tin, antimony, and tellurium ;
the metals should be finely divided or in powder; silver and oxide of
silver decompose it very suddenly with the evolution of heat and light;
platinum and gold produce the same phenomena; lead and mercury
slowly separate the oxygen. Orpiment and powdered sulphuret of
molybdenum act upon it with the same violence as silver; the peroxides
of manganese and of lead also occasion its instant decomposition.
BOLOGNESE PHOSPHORUS.
437
A solution of nitrate of baryta, or one of the chloride of barium, is the
test for sulphuric acid, with which it forms an insoluble white precipi-
tate, already alluded to as sulphate of baryta.
The famous "phosphorescent Bolognese stone" is made from a ra-
diated variety of heavy spar found near Bologna. The process consists
in heating the mineral in conjunction with carbonaceous matter; most
likely it is saturated with mucilage of gum arabic, or, perhaps, pure olive
oil, and then calcined, and if exposed to the sun and afterwards brought
into a darkened room, it emits a faint glow of light.

Fig. 233. The Bolognese Phosphorus.

!!!
Fig. 234. Lady at her Toilette applying the "Pearl-white" with a Hare's-foot.
CHAPTER XV.
BISMUTH.
WHEN God's image is defaced with a mineral and poisonous powder, it
must of course be for some special purpose; now, the savage tribes
chiefly wear paint when they go to battle, to frighten their enemies,
and hence the term " war paint," used by modern writers to express
this peculiar decoration worn by a few silly women, is perhaps one of
the severest reproofs ever administered to that absurd and foolish
practice. The metal bismuth, so called from the German wiessmate,
or "blooming meadow," is the one selected for this office; not, of
EXPERIMENTS WITH BISMUTH.
439
course, in the metallic state, but combined with nitric acid and water,
and called the trisnitrate of bismuth, or "flake white," Bi,O,NO,+HO.
This metal occurs in the native and mineralized state in various parts of
Europe, and also in Cumberland and Cornwall. The greater portion of
the bismuth sold in commerce is obtained by melting the "native bis-
muth" with certain precautions.
The metal is very brilliant, crystalline, and brittle, and as it fuses at
a very low temperature, 477° Fah., beautiful cubic crystals (Fig. 235)
like steps may be obtained by allowing a crucible full to cool till a pellicle
forms on the top. This is then pierced with two holes, out of one of
which the remaining liquid metal is poured, and the other allows the air
to enter as the metal is displaced.
The specific gravity of bismuth is 9.8, and its equivalent 213.
EXPERIMENTS WITH BISMUTH.
First Series.
Bismuthic acid, BiO,, and teroxide of bismuth, BiO,, are the scientific
oxygen compounds of this metal. The former is only interesting to the
chemist, but the latter is the oxide in combination with nitric acid already
spoken of as "flake white," and obtained by dissolving bismuth in nitric
acid, and pouring it into water; by subsequent washing, the desired
cosmetic is obtained, and great care is required in making it to please
the fastidious eyes of Vanity Fair.
Second Series.
Ignition is sometimes produced during the violent action that takes
place when nitric acid is poured upon powdered_bismuth. Nitrate
of bismuth is readily prepared by dissolving as much of the metal as a
mixture of two parts nitric acid and one of water will take up. The
decomposition is extremely rapid, and nitric oxide gas escapes in large
quantities. The solution affords, on careful evaporation, beautiful
four-sided prismatic crystals, which are decomposed at a red heat and leave
oxide of bismuth. A most amusing form of invisible ink is obtained by
writing on paper with a solution of nitrate of bismuth; the letters do
not become visible until the paper is dipped into water, when the pearl
white or blanc de fard, or magistery of bismuth, is precipitated-thus
forming a white sympathetic ink.
Third Series.
The fusible metal that melts when placed in boiling water consists of
eight bismuth, five lead, and three tin, and some persons-of course
wags have even gone to the expense of having it made into spoons ;
and the surprise of any grave personage who uses such a base spoon to
stir his or her tea, to see that usually solid article of plate melt away
before their eyes, may be more readily conceived than described. Pew-
ter and type-metal also contain bismuth.
440
BISMUTH.
Fourth Series.
Bismuth is detected by sulphuretted hydrogen, which throws down
a black precipitate of tersulphide of bismuth, BiS,, from solutions of
that metal, which is insoluble in dilute acids, alkalies, alkaline sulphides,
and cyanide of potassium, but decomposed by concentrated boiling
nitric acid.
Chromate of potash throws down a yellow precipitate of chromate of
bismuth; unlike chromate of lead, being insoluble in potash, but soluble
in dilute nitric acid.
The most characteristic reaction is the effect of water on solutions of
bismuth, which are precipitated as white basic salts insoluble in tartaric
acid.

Fig. 235. Crystallized Bismuth.
CHAPTER XVI.
CADMIUM.
THIS metal was discovered in 1818 by Stromeyer, and is so called
from "Kaduela," being the ancient name for the mineral containing
zinc, used in the manufacture of brass; and as cadmium is a sort of
twin brother to zinc, and is usually associated with it in nature, the
title of cadmium was selected for it.
Mr. Herapath, the eminent chemist of Bristol, was the first to point
out that the yellowish-brown matter adhering to the brick vault placed
over the furnace and pots in which the zinc is distilled from calamine,
contained about ten per cent. of cadmium.
The sublimate gradually collected from the "brown blaze" of the
zinc furnace may be dissolved in dilute sulphuric acid, and on placing
the solution in a platinum cup, according to the elegant method of Dr.
Wollaston, and holding a zinc plate therein, the cadmium is precipitated
on the sides of the vessel, and adheres so firmly that it may be washed and
afterwards dissolved out with acids. Cadmium is a white, or bluish-grey
metal, having a specific gravity of 8-6; it is soft, malleable, and ductile, and
admits of being highly polished. There is only one oxide of cadmium,
CdO, and if in solution, the metal is rendered apparent by the rich
yellow precipitate of sulphide of cadmium, CdS, when sulphuretted
hydrogen or sulphide of ammonium are added; insoluble in alkalies and
dilute acids, but decomposed by strong nitric acid; likewise insoluble
in an excess of sulphide of ammonia, which distinguishes the precipitate
from the same colour obtained under similar circumstances with anti-
mony, arsenic, and tin, all of which as sulphides are soluble in an excess
of the sulphide of ammonium. Potash and ammonia throw down white
precipitates of hydrated oxide of cadmium, insoluble in the former but
soluble in ammonia.
The useful arts have not as yet been benefited by cadmium, except,
perhaps, in the preparation (as Dr. Percy states) of the finest and most
durable yellow colour with which the artist is acquainted, and made
from the sulphide of cadmium.

Dista
4171

Fig. 236. Lime Kilns.
CHAPTER XVII.
CALCIUM.
ALL over the country, in the most picturesque forms and situations, are
to be seen numberless kilns or rude furnaces in which the well-known
substance lime is prepared by burning chalk or limestone, both of which
are impure forms of carbonate of lime. The existence of the metal cal-
cium in lime was satisfactorily proved by Davy, who employed the same
process to procure it as that described for the metal barium. The impetus
given by M. St. Clair Deville to the cheaper production of these metals of
the earths and alkalies, by the employment of sodium, has induced MM.
Bunsen and Matthiessen to prepare calcium in quantity, and thus fill in
a void which is apparent in all works on the metals-viz., the absence
of a correct description of the properties of calcium.
EXPERIMENTS WITH CALCIUM.
First Series.
In a valuable paper by Dr. Matthiessen, "On the Preparation of the
Metals of the Alkalies and Alkaline Earths by Electrolysis,"* that
* Quarterly Journal of the Chemical Society, vol. viii. p. 27.
MATTHIESSEN'S RESEARCHES WITH CALCIUM.
443
gentleman gives the following description of the preparation and pro-
perties of calcium. "A mixture of two equivalents of chloride of
calcium and one of chloride of strontium with a small quantity of chloride
of ammonium, is fused in a small porcelain crucible, in which a carbon
positive pole is placed, and a thin harpsichord wire, wound round a
thicker one, dipping only under the surface of the melted salt, is con-
nected with the zine of the battery formed of six of Bunsen's elements,
the current of which is allowed to pass through the mixture.
r
"In order to obtain the beads of calcium, which hang on to the fine
wire, the negative pole must be withdrawn, about every two to three
minutes, along with the thin crust that forms round it. The surest me-
thod, however, to obtain the metal (although in very small beads), is by
placing a pointed iron wire merely so as to touch the surface of the
liquid; the great heat evolved, owing to the resistance to the current,
causes the reduced metal to fuse and drop off from the point of the
iron wire, and the bead is recovered from the liquid by means of a small
iron spatula.
"The properties of calcium are the following: it is a light yellow
metal of the colour of gold alloyed with silver, and has a specific
gravity of 1.5778; on a freshly-filed surface the lustre somewhat de-
creases the yellow colour, which becomes more apparent if the light be
reflected several times from two surfaces of calcium; a thin film of
oxide produces the same effect. The hardness approaches that of gold,
being from two to three. It is particularly ductile, and may be cut,
filed, and hammered out to plates having the thickness of the finest
paper, a piece not larger than a mustard seed having been flattened to
the size of ten to fifteen square millimètres, showing only a few cracks
at the border.
In dry air the metal retains its colour and lustre for a few days only,
but in presence of moisture the whole mass is slowly oxidized. Heated
on platinum foil over a spirit lamp, it burns at a red heat with an ex-
cessively bright flash, about equal in intensity to the voltaic arc. Cal-
cium is only slowly acted upon by dry chlorine; but when heated, burns
in that gas with a most brilliant light, as also in iodine, bromine, oxygen,
sulphur, &c. With phosphorus it combines without ignition, forming
phosphide of calcium. Heated mercury dissolves it to a white amalgam.
Water is rapidly decomposed by the metal, with the evolution of great
heat and hydrogen; diluted nitric, hydrochloric, and sulphuric acids
cause a still more rapid decomposition; the first acid often causing ig-
nition. Concentrated nitric acid, even when heated almost to boiling,
does not attack the metal, the action not beginning till the liquid boils.
From these experiments, it appears that the metal formerly stated to
have been obtained by the reduction of chloride of calcium with the
alkaline metals cannot be calcium, but was most probably a mixture of
potassium or sodium with aluminium, silicon, &c."
444
CALCIUM.
Second Series.
The equivalent of calcium is 20, and it forms with oxygen the well-
known oxide, lime (CaO), and is also capable of uniting with another
equivalent of oxygen to form the peroxide of calcium, CaO,. The
mode of burning limestone, in order to drive off the interstitial water
and combined carbonic acid, is very simple: a lofty inverted conical
furnace is constructed with a proper hearth, over which a rude arch of
lumps of the limestone is constructed; below the arch, which has many
apertures left for the upward passage of the fire, is arranged the fuel,
and above it the smaller lumps of the chalk or limestone; the fire is
lighted carefully, and, gradually increased, in about seventy hours the
process of burning is completed. Lime is a brittle and somewhat
sonorous white earthy solid, having a specific gravity of 2-3; it is ex-
tremely infusible, and is the substance selected for ignition with the in-
tense heat of the oxyhydrogen blowpipe to produce the beautiful white
light required for the exhibition of dissolving views, called the "lime
light." After being exposed for some time to the action of the heat, a
hollow is scooped out in the ball by the volatilization of the lime. All
round the point where the jet of the mixed gases impinges on the sur-
face of the ball, the lime is most beautifully crystallized. One of the
inconveniences of this light caused by the cracking of the lime has
been in a great measure surmounted by Prosser, who causes a thick
slab of lime to move upwards in a brass frame (instead of the ordinary
rotation) by clockwork. Many years ago, Mr. Frederick Gye, the pro-
prietor of the Covent Garden Opera House, constructed and used a
good-sized slab of lime ground flat on one surface, and worked by an
eccentric, so as to avoid the trouble of replacing cracked lime balls, and
also to prevent the sudden eclipse of the light when this takes place.
The application of the lime light has now, perhaps, reached its cul-
minating point, having been used, during a part of the time Parliament
was sitting this year, to illuminate the new Westminster Bridge at
night, in the most admirable manner. When water is added to fresh-
burnt lime, it unites chemically with that substance and forms the
hydrate of lime, CaO,HO; this combination takes place with the evolu-
tion of considerable heat, and is usually called "slaking," whilst the
hydrate is distinguished from the caustic lime by the term of "slaked
lime.” When the latter is shaken with some cold water in a bottle pro-
vided with a cork or stopper, and then allowed to settle, the clear solu-
tion is called lime water, and is employed as an important test for car-
bonic acid; see "Boys' Playbook of Science," p. 154.
Lime water, like baryta water, powerfully reddens turmeric paper,
and if a little sugar is mixed with the slaked lime, water dissolves a
much larger quantity. The chief test for lime is oxalic acid in the form
of oxalate of ammonia, which precipitates the white oxalate of lime,
insoluble in acetic and oxalic acids. Sulphate of soda precipitates sul-
phate of lime, CaO,SO,HO+Aq, from concentrated solutions of lime,
ŝoluble in a large proportion of water, and more so, on the addition of
EXPERIMENTS WITH CALCIUM.
445
acids. A little alcohol added to weak solutions of lime will assist the
precipitation of the sulphate.
Third Series.
The number of minerals that are formed of lime salts may truly be
called "legion."
Count Bournon has described seven hundred varieties of calc spar or
carbonate of lime, of which the following well-known substances may
be mentioned :—Marble of all kinds, oolite egg or roe-stone, pisolite,
chalk, marl, tufa, double-refracting spar.
Fluor spar, or "blue John," so common in Derbyshire and elsewhere,
is a fluoride of calcium. Phosphate of lime, the important chief earthy
constituent of bone, takes a position as a manure which is not surpassed
by any other metallic salt. The eminent practical and scientific agri-
culturist, Mr. Lawes, has clearly shown that phosphates are the manure
for turnips and other root crops.
Gypsum, or sulphate of lime, is another common mineral, of which the
transparent crystals are called selenite, and are used for objects in the
polariscope; whilst the same mineral when calcined forms that truly
valuable medium by which sculpture and other works of art are copied
in the well-known substance termed "plaster of Paris."
Lime and its combinations are therefore amongst minerals almost what
oxygen is in the non-metallic group of elements; and lime is used not
only for mortar, cement, manure, tanning, soap-boiling, &c., but is
employed in the state of carbonate for sculpture, architecture, and
general ornamental stone-work, whitewashing, soda-water making, &c.;
also in glass-making, and, as already shown, is the important flux for
iron-stone.
Fourth Series.
Amongst the reagents that indicate the presence of lime in solution,
may be mentioned the carbonates of the alkalies, which throw down
white precipitates of CaOCO₂. In acid solutions, boiling assists the
entire precipitation of the carbonate of lime, and the presence of am-
inoniacal salts do not prevent this precipitation.
Dilute sulphuric acid, or soluble salts containing it, throw down
lime from concentrated solutions as a white precipitate of sulphate of
lime, CaOSO,, perfectly soluble in acids, and also in large proportions
of water. In less concentrated solutions, the precipitates are only
formed after the lapse of some time; and no precipitation whatever
occurs in very dilute solutions. If solutions of lime are not sufficiently
concentrated, the addition of alcohol will cause the immediate precipi-
tation of sulphate of lime.
Oxalic acid produces a most characteristic precipitate of oxalate of
lime, CaO,O+2 aq, in dilute or strong solutions, and the detection of
the lime with oxalic acid is rendered more certain by the subsequent

446
CALCIUM.
addition of ammonia, or by using oxalate of ammonia instead of the
acid.
The soluble salts of lime improve the red colour of the flame obtained
by burning alcohol containing nitrate of strontium, and indeed, the
colour so obtained with lime salts is frequently mistaken for that of
strontium.
STEREOSTOP
STERNOST
Fig. 237. Immense specimen of Cale Spar, called Double-Refracting Spar, from
Professor Tennant's collection. Proportions, nine inches high, seven inches and
three-quarters broad, five inches and a half thick; estimated value, one hundred
pounds.

Fig. 237. Scene of the Labours of Ceres.
CHAPTER XVIII.
CERIUM.
THE good, kind goddess who presides over the material for the
"quartern loaf," gives the name to this metal, which was discovered in
1803 by Hisinger and Berzelius, in a mineral that comes from Sweden
called "cerite," and found only in the Bastnaes copper mine near
Ridderhyttan. The mineral consists, according to Klaproth, of-
Silica.
Protoxide of cerium
Peroxide of iron
Lime.
Water
Loss [?], oxides of lanthanium, didymium, &c.
34.5
50-75
3.5
1.25
5.0
5.0
It is stated to be a white, brittle metal, volatile at high temperatures,
and soluble in aqua regia. It is not as yet applied to any useful
purpose, although it might prove to be valuable in the state of
oxide for painting on porcelain or colouring glass. The equivalent
of cerium is 47, and it forms with oxygen a protoxide, CeO, and
peroxide, Ce,O3.
CHAPTER XIX.
CHROMIUM.
If there was one part more than another, in the Great Exhibition, which
was crowded from morning till night, it was the locality where the
Queen of Spain's jewels were exhibited, under the guardianship of a
trusty policeman; and yet people hardly thought, perhaps, what they
elbowed each other to gaze at, and the generality of the spectators did
not know that the emeralds were only composed of the usual ingredients
of clay-viz., silica and alumina, with some glucina and lime, but
coloured with oxide of chromium, with a small quantity of peroxide of
iron. It is, indeed, from this special property of colouring glass a
lovely green, and making valuable pigments with lead, &c., that the
metal derives its name xpôμa, colour. It was discovered by Vauquelin
in 1797, and first obtained from crocoisite, which is a natural dichromate
of lead, containing about thirty per cent. of chromic acid. It occurs
in Hungary, Silesia, the Ural Mountains, and other places.
The metal is obtained, like aluminium, by the action of sodium on the
sesquichloride of chromium. It possesses brilliancy, with a greyish
colour; is hard, brittle, and not easily oxidized by air or water. Its
magnetic power is curious, and this virtue is exalted by a low and
diminished by a high temperature.
EXPERIMENTS WITH CHROMIUM.
First Series.
The equivalent is 26·7, and there are numerous oxides of chromium
—viz.,
Protoxide of chromium.
Sesquioxide of chromium
Chromic acid
•
Perchromic acid
Cro
Cr₂03
Cro3
Cr₂07
Like alumina, the sesquioxide of chromium forms chrome alums with
potash, soda, and ammonia, but chromic acid is the most important
compound, because it forms with potash the valuable commercial salt
called bichromate of potash, used for making various important pigments
with lead, and is the source of the various oxides and salts of chromium.
This metallic acid is one of the most powerful oxidizing agents known,
and is therefore sometimes used for bleaching purposes. If some abso-
EXPERIMENTS WITH CHROMIUM.
449
lute alcohol, prepared by distilling ordinary alcohol from chloride of
calcium, is slightly warmed and thrown suddenly on crystals of chromic
acid, the oxidation takes place so rapidly, that the remaining alcohol
usually catches fire. Warington has recommended chromic acid in a
certain voltaic arrangement, described in the "Transactions of the
Chemical Society" (vol. i. p. 61):-
“My first endeavour was to substitute this mixed fluid (bichromate
of potash, 206.9, concentrated sulphuric acid, 275-8) for the nitric acid
in the powerful arrangement of Professor Grove, so as, if possible, to ob-
viate the inconvenience arising during the action of that battery, without
diminishing the splendid effects produced by it. In doing this, it was
absolutely necessary, from the nature of the materials to be employed,
to modify to a certain extent the details of the construction of the
battery, retaining the metallic elements unaltered, but enlarging con-
siderably the cell appropriated for the nitric acid."
Second Series.
A solution containing oxide of chromium is not examined without
attracting observation from its emerald-green colour. The sesqui-
oxide of chromium, like alumina, is soluble in potash, and precipitated
by chloride of ammonium; and by fusion with nitre, the oxide is converted
into chromic acid, which yields with solutions of lead either the yellow
or orange chromates of lead; indeed, the chromates are all red or
yellow-the neutral solutions affording yellow chromates, or red on the
addition of acid.
Nitrate of silver gives a dark reddish-purple precipitate of chromate
of silver, soluble in nitric acid and ammonia.
Chromic acid is reduced to the state of oxide by oxalic, citric,
tartaric, and sulphurous acids, and by hydrochloric acid and alcohol.
Any chromate fused with borax yields a beautiful emerald-green
colour.
Chromic acid in combination with chlorine, as chloro-chromic acid,
CrCl,2 CO₂, is perhaps one of the most, if not the most powerful
oxidizing agent with which we are acquainted. It is easily prepared
by fusing together ten parts salt and seventeen bichromate of potash.
When cold, the mass is broken into small lumps and placed in a retort
with thirty parts of oil of vitriol, and heat applied, when a vapour
distils over, which must be carefully condensed. It is a dark, red-
dish-brown liquid, very volatile, and emits dark-brown vapours; if
hydrogen is passed through a tube containing pumice moistened with
chloro-chromic acid, and burnt, the flame is white, and deposits the
green sesquioxide of chromium upon any white porcelain plate or cup
held in the flame.
G G

いい
​Fig. 239. Kobold, the Gnome or Sprite supposed to haunt the German Mines.
CHAPTER XX.
COBALT.
THE supposed origin of the name of cobalt is apparent from the vignette
and description at the head of this chapter; but whether the Germans
really had a superstitious dread, like the Cornish miners, of evil spirits,
or whether they simply abhorred the presence of cobalt because they con-
sidered it useless, and only wasting their time (by obliging them to remove
it, to obtain more valuable minerals), is not perhaps fully known; an odd
mixture of both ideas may perhaps have pervaded their minds, as they,
like the "Roundheads," who prayed against Prelacy, Popery, and Peveril
EXPERIMENTS WITH COBALT.
451
of the Peak, also invoked the good powers against kobalts and spirits.
Truly, knowledge is power, for the cobalt ores of Hesse were formerly
used to repair the roads, and now yield a profit of many thousands per
annum.
The metal is obtained either by heating the oxalate of cobalt in a glass
tube like tartrate of lead (and is then pyrophoric when brought into con-
tact with the air), or it may be obtained by passing dry hydrogen gas
over oxide of cobalt heated to redness in a hard German glass tube: in
this state (like many other metals) it is also spontaneously combustible.
Cobalt has a specific gravity of 8.5; it is moderately brilliant, and re-
quires a powerful heat for its fusion. Like iron, it is attracted to the
magnet, and may, indeed, according to Wenzel, be made into a magnetic
needle. In olden time, all the cobalt ore came from Germany, but now
large quantities are obtained from Cornwall, Cumberland, and the Men-
dip Hills. The chief ores of cobalt are-
Name.
Tin-white cobalt ore, or arsenical (
cobalt, or smaltine.
Cobaltine, or bright white cobalt,
or glance cobalt
Composition.
Cobalt, iron, nickel, copper,
bismuth, arsenic, and sulphur.
Cobalt, iron, arsenic, and sul-
phur.
Smaltine and cobaltine are used in preparing zaffre, which is merely
the ore calcined to drive off the arsenic, and afterwards powdered.
Smaltine is roasted and melted with pounded quartz or glass, and smalt,
a compound used most extensively for the cheap blue patterns of crockery-
ware, and especially for an old friend, the "willow pattern," Fig. 240.
A very minute quantity of the oxide of cobalt is sufficient to impart the
blue colour to the design, and it is stated that one grain of the oxide
will give a full blue to 240 of glass.
EXPERIMENTS WITH COBALT.
First Series.
The equivalent for cobalt is 29·5, and it unites with oxygen in two
proportions, viz.:-
Protoxide of cobalt
Sesquioxide of cobalt
•
Coo
Co₂03
Cobalt, dissolved in nitric acid, may be precipitated with a solution of
potash as the blue hydrated oxide of cobalt, convertible by heat, but
out of contact with the air, into the protoxide of cobalt. The hydrated
oxide, suspended in water, is converted into black hydrated sesquioxide
by passing chlorine gas through it, and on heating the hydrate, it is
converted into the sesquioxide of cobalt. A beautiful red liquid is ob-
tained by dissolving oxide of cobalt in ammonia, and is used in a dilute
state for chemists' show bottles. The nitrate of cobalt is a valuable blow-
pipe reagent, and yields a beautiful green with oxide of zinc, or blue with
G G 2
452
COBALT.
alumina, and a feeble rose tint with magnesia. The substances under
examination may be powdered, heated on charcoal, and then moistened
with the smallest drop of a solution of the nitrate of cobalt, and finally
heated to redness. Silica also affords a blue colour with the same re-
agent, but the intensity is very different from that of alumina.
Second Series.
By dissolving the oxide of cobalt in hydrochloric acid, a pink solution
of the chloride of cobalt is obtained, which turns to blue when it is
evaporated to dryness; hence the use of this solution for sympathetic or
invisible ink, which becomes apparent when the writing is held to the
fire. The idea of such secret communication is not new, for Ovid
mentions the use of milk for writing, which may be rendered visible by
dusting on soot; and Pliny recommends the milky sap of plants, such as
the dandelion, for the same purpose. The first use of the solution of
cobalt as an invisible ink is ascribed to Hellot. The discoverer appears
to have been a German named Stolberg, who probably met with the ko-
balt in his visits to certain mining districts, and trying the effect of
aqua regia upon it, produced a red salt, that turned blue on exposure
to heat. The following are the different solutions of cobalt which are
invisible until another reagent, or heat, is applied.
Green sympathetic ink consists of a solution of acetate or chloride of
cobalt with a small quantity of a salt of nickel and a little chloride of
calcium to keep the writing damp; when heat is applied, a bluish-green
colour appears.
Blue is obtained by writing with a dilute solution of nitrate of cobalt,
and then washing it over with one of oxalic acid, and heating it strongly
before a fire.
Third Series.
Chloride and sesquichloride of cobalt are known to chemists; the
former, CoCl, is prepared by dissolving the oxides of cobalt in hydro-
chloric acid, when a beautiful pink-coloured solution is obtained; which,
if carefully evaporated and crystallized, affords pretty rose-coloured
crystals of the chloride combined with water. The solution of chloride
of cobalt is green when it contains iron or nickel, or blue if it con-
tains an excess of acid. The red again appears if it is mixed with a
large quantity of water.
When the hydrated chloride is heated, it parts with the combined
water, and becomes blue; hence the use of the chloride in the pre-
paration of sympathetic ink. Letters written with the pink chloride
are invisible until held before the fire, when they appear blue; and
if a little salt is mixed with the chloride, it is not so likely to remain
permanently blue, as will happen sometimes when too much heat is
applied.
COBALT AND CHINESE BLUE.
Fourth Series.
453
Cobalt is detected by the blowpipe when a drop of any of its solutions
is heated red-hot in conjunction with oxide of zinc, alumina, or silica,
as already described.
Sulphuretted hydrogen precipitates with difficulty a black sulphide
from neutral, but not from acid solutions of cobalt.
Sulphide of ammonium completely precipitates the sulphide from
neutral and alkaline solutions of cobalt.
Potash precipitates a dirty blue, which changes to green when exposed
to the air.
Ammonia precipitates and redissolves the oxide of cobalt, forming a
beautiful red solution.
Fused borax, powdered and moistened with a solution of cobalt, and
then taken up on a platinum wire loop, and heated by the blowpipe
flame, yields that characteristic blue which is so usefully employed in
colouring glass and china.

Fig. 240. The Willow Pattern Plate. An illustration of the use of the oxide
of cobalt; being the much-lamented Albert Smith's last advertisement.

Fig. 241. The Rainbow, which is typical of the multiplicity of colours obtained
from metals.
CHAPTER XXI.
DONARIUM, DIDYMIUM, ERBIUM, GLUCINUM, ILMENIUM, IRIDIUM,
LANTHANIUM, AND LITHIUM.
THE first-named metal was discovered by Bergmann, in certain minerals
from Norway. The second, so called from Didumos, "twins," a fanciful
allusion to its connexion with lanthanium, is extracted from cerite, a
mineral already alluded to at p. 447, in the article "Cerium." M.
Marignac has published some valuable researches on didymium and
its principal compounds, and has also determined the atomic weights of
cerium and lanthanium, and approximatively that of didymium.
Cerium
Lanthanium
Didymium
Atomic weight.
47-26
47.04
49.4
LITHIUM, THE LIGHTEST METAL.
455
Erbium is obtained from a mineral called gadolinite, composed,
according to Berzelius, of
Silica
Yttria.
25.8
•
45.0
Protoxide of cerium
16.69
Protoxide of iron
Water.
10.26
•60
Loss [?], oxide of erbium
1.65
100.00
Glucinum has already been mentioned as a constituent of the emerald,
which is a double silicate of alumina and glucinum, coloured with oxide
of chromium. The beryl and chrysoberyl also contain it.
Ilmenium.-The existence of this metal has been challenged by Rose;
indeed, many more experiments are required to be made with some of
these alleged new metals before they can be said even to exist.
The latter metal is stated to have been discovered by Hermann, in
Siberian yttro-tantalite, or rather Samarskite, but H. Rose showed that
he had mistaken niobic for ilmenic acid, and, therefore, that such a metal
did not exist.
Iridium deserves special notice, because, although rare, it is now used
in the shape of the very hard native alloy of osmium and iridium, for the
tips of the so-called gold pens; it is likewise employed in the state of
oxide, to produce a most intense blackness in painting on porcelain; and
it is stated by Dr. Percy that all other porcelain black colours appear
grey by the side of it. It is not, perhaps, surprising that iridium should
be remarkable for its qualities as a pigment, when we search into the
origin of the name, which refers to its colour-giving powers as if it were
similar in this respect to an iridescent soap-bubble, or the pretty iris
produced by the deposit of dew on the spider's web (Fig. 242).
Lanthanium is also derived from the mineral cerite, and the only
oxide known is a white powder!
Lithium is the lightest metal known, having only a specific gravity of
0.5936, and is obtained from the oxide of lithium or lithia, which occurs
in various minerals, and especially in petalite and spodumene, which are
silicates of alumina and lithia, containing about nine per cent. of the
latter.
Professor Bunsen, in a letter to Liebig, describes his method of pre-
paring lithium:-"Pure chloride of lithium is fused over a Berzelius
spirit-lamp in a small thick porcelain crucible, and is decomposed by a
zinc coke battery, consisting of four to six cells. The positive pole is a
splinter of gas coke (the hard carbon deposit in the gas retort), and the
negative an iron wire about the thickness of a knitting-needle. After a
few seconds, a small silver-white regulus is formed under the fused
chloride round the iron wire and adhering to it, which, after two or three
minutes, attains the size of a small pea: to obtain the metal, the wire
pole and regulus are lifted out of the fused mass by a small, flat-
456
LITHIUM.
spoon-shaped, iron spatula. The wire can then be withdrawn from the
still melted metal, which is protected from ignition by the chloride of
lithium with which it is coated. The metal may now be easily taken
off the spatula with a penknife, after having been cooled under rock
oil. As this operation can be repeated every three minutes, an ounce
of chloride of lithium may be reduced in a very short time.
Lithium, on a fresh-cut surface, has the colour of silver, but tarnishes
after having been exposed for a few seconds to the air, and becomes
slightly yellow. The melting-point is 180° C. A piece of it at that
temperature, if pressed between two glass surfaces, exhibits the colour
and brightness of polished silver. Lithium is harder than potassium or
sodium, but softer than lead, and therefore can be pressed out, like that
metal, to wire. By pressure lithium can be welded at ordinary tempera-
tures; it swims on rock oil, and is the lightest of all solid bodies.
The salts of lithium are stated to impart a red colour to the inner
blowpipe flame; and lithia, LiO, is usually considered to be the interme-
diate link between the alkalies and alkaline earths. The atomic weight
of lithium is 81·7.

Fig. 242. The Spider's Web upon which dew deposits, and, when lighted by a
sunbeam, produces the beautiful prismatic colours of the iris, the origin of the
word iridium.

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PICKLE,
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MEDICINE
CHEST
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Fig. 243. Domestic Use of Magnesia and its Sulphate.
CHAPTER XXII.
MAGNESIUM.
THIS metal is another of the metallic bases of the earths, and claims
Davy for its discoverer. Bussy, however, in 1830, prepared it in much
larger quantities by a somewhat similar process to that used by St.
Clair Deville with alumina. Bussy employed chloride of magnesium,
which he decomposed by potassium, with the assistance of heat. The
metal has the following properties: it is brilliant, silvery white, perfectly
ductile and malleable, fusible at a moderate temperature, like zinc,
volatilized at a temperature a little higher than that of its melting
point, and, like that metal, condenses into small globules. It has a
specific gravity of 1743, and does not decompose water at common
temperatures; it oxidizes at a high temperature, and is slowly converted
458
MAGNESIUM.
into magnesia when in small masses; but when finely divided, as in filings,
it burns with great splendour, throwing out sparks like iron in oxygen.
Magnesium has lately been made in much larger quantities, and can
now be obtained at a moderate price, so that enthusiastic practical men
have suggested its employment as a magnesium lamp, on account of the
very great brilliancy of the light which it evolves during combustion;
indeed, nothing can be more brilliant than this union of oxygen gas with
magnesium. Dr. Matthiessen recommends the use of a mixture of the
chlorides of potassium and magnesium in nearly equal proportions, in-
stead of the anhydrous chloride; the quantities are three equivalents of
chloride of potassium to four of chloride of magnesium. The solution
of the chloride of magnesium can be evaporated almost to dryness, and
analysed to find the amount of the anhydrous salt present. After
having mixed the two salts in the proper proportions with some chloride
of ammonium, the mixture may be fused and electrolysed by Bunsen's
method, the pockets not being required, as the metal is specifically
heavier than the fused mixture. A very simple and convenient way of
reducing the metal, especially for the lecture-table, is in a common clay
tobacco-pipe, over a Berzelius spirit-lamp, the negative pole being an
iron wire put up the pipe-stem, and the positive being a piece of gas
coke just touching the surface of the fused chlorides.
The minerals that contain magnesium are found in very large quan-
tities, and amongst them may be specially noticed the following; viz.—
Name.
Dolomite, or magnesian limestone.
Steatite, or soapstone, a variety of
which is called Spanish chalk,
whilst another is used by certain
savage tribes as a portion of their
food; another is called meer-
schaum, of pipe celebrity; a fifth
serpentine; a sixth variety is
asbestos, or amaranthus, of which
the fibres are elastic and flexible,
and used in the manufacture of
incombustible cloth; a seventh,
tale, used frequently instead of
glass for windows; and an eighth,
potstone, which is formed into
culinary vessels in Greenland and
Hudson's Bay.
Magnesian mica
Composition.
Carbonate of magnesia, carbonate
of lime, with some oxide of
iron and manganese, silica, and
alumina.
Silica, magnesia, with some alu-
mina, oxide of iron, manganese,
potash, and lime.
Silica, alumina, magnesia, with
some oxides of iron, potash,
fluoric acid, and water.
WOLLASTON'S METHOD OF DETECTING MAGNESIA.
459
Certain spring waters retain an abundance of sulphate of magnesia
in solution-such as the Norwood and Epsom springs, of which the
latter has given the name to that popular, because cheap, medicine
called "Epsom salts." The water of the ocean likewise contains a large
quantity of magnesia. The well-known medicine called calcined mag-
nesia is prepared by precipitating a solution of magnesia by boiling it
with one of carbonate of soda; the carbonate is then well washed and
calcined, and by the application of a proper heat is converted into
magnesia, MgO.
The equivalent of the metal magnesium is very low, being only 12;
and it has for that reason, in a great measure, been proposed as a light-
giving agent. The equivalent of carbon is 6, and therefore, if the
metal could be procured at a very cheap rate, there is no reason why it
should not be used for special purposes of illumination. The only oxide
known is magnesia, the preparation of which has already been described.
This alkaline earth, in the state of carbonate, is freely dissolved by
carbonic acid, and has been employed most efficaciously for many years
as a domestic medicine under the name of "Dinneford's fluid magnesia."
If water is added to calcined or caustic magnesia, it does not com-
bine chemically with, and "slacken" this earth, like lime, baryta, or
strontia; neither does magnesia absorb carbonic acid from the atmo-
sphere, hence caution must be used in selecting and burning limestones
for agricultural purposes, on account of the magnesia remaining in an
alkaline or caustic state.
Dr. Wollaston, whose laboratory consisted of a tray containing a few
bottles, watch glasses, and glass tubes, &c., was the first to point out
an elegant method of detecting magnesia in minerals supposed to
contain it. "Dissolve with aqua regia in a watch glass a minute frag-
ment of the mineral; and if it is not soluble, it must be rendered so by
previous fusion with carbonate of soda. Render the solution neutral
by cautious evaporation; then, while hot, add a little oxalate of am-
monia, to precipitate any lime which it may contain. Let the pre-
cipitate fall, and take a few drops of the clear liquid, and put them on
a slip of window glass. Add a drop or two of bicarbonate of am-
monia, and afterwards a drop or two of biphosphate of ammonia.
Then draw a little of the clear solution to one side of the slip of glass,
and trace any letters or lines across it with a glass rod. On exposing it
to a gentle heat, white traces will be perceived wherever the rod was
applied."
Ammonia precipitates from the solutions of neutral salts of magnesia
a portion of the magnesia as hydrate of magnesia (MgO,HO); the other
portion remains in solution, forming a double-salt with the ammonia
perfectly soluble in water. It is this circumstance which renders Wol-
laston's method of detecting magnesia so important, because of the
insoluble basic phosphate of ammonia and magnesia (2MgO,NH,O)
(PO₂+2HO+10aq) produced in the presence of an excess of ammonia by
the addition of a solution of phosphate of soda to one of magnesia.

Fig. 244. The Chameleon.
"Of the chameleon's food I eat (the air)."
HAMLET.
CHAPTER XXIII.
MANGANESE.
THE little animal that heads our present chapter has given rise to much
discussion, in consequence of the curious changes of colour that it is
said to be capable of producing at its own will and pleasure; and the
fanciful writer has little difficulty in assuming that the animal suffers
from anger when he turns red; jealousy, of course, if yellow; but
is amiable and serene when blue. Into these varieties of colour or
temper, of course, we do not enter; but merely state that manganese
is capable-like antimony, chromium, arsenic, tellurium, tungsten, and
others-of forming acids with oxygen; and that this compound is
called manganic acid, which, in combination with potash and dissolved in
water, affords a complete series of spontaneous chromatic changes of
the most curious description; and, indeed, from this curious circum-
stance the salt is called “Chameleon Mineral,” and its preparation and
composition will be explained in another part of this chapter.
The metal manganese, so called, according to Sir Robert Boyle, from
its resemblance to the magnet, appears to have been known only in
combination with oxygen gas in the common mineral called "black oxide
of manganese;" and it was this accomplished philosopher who discovered
the first mine of it in England. The mineral was used 2000 years ago,
and is now employed in the manufacture of the best crystal or flint
glass, to which it is said to confer a greater brilliancy in consequence
of the delicate amethystine colour it imparts to this siliceous mix-
EXPERIMENTS WITH MANGANESE.
461
ture. Moreover, it does to all intents and purposes bleach the glass
whilst the materials are in a state of liquefaction and incorporation, by
giving oxygen to any carbon or protoxide of iron that may be present,
and discolour the pot of glass; hence it is called "Glass Maker's Soap
the oxygen it contains burns away the carbon, and at the same time
converts the protoxide of iron into peroxide, which is colourless when
united with silicic acid.
"

This metal, after evading the processes of Boyle, Glauber, Haig, Pott,
Kaim, Bergmann, and Scheele, at last rewarded the persevering efforts of
chemists, by appearing to the summons of Dr. Gahn, who, by mixing
some black oxide of manganese with oil in balls, and placing them in a
crucée brasquée, or crucible lined with charcoal, and then applying a most
intense and vigorous heat, was rewarded (Chinese fashion) with a button,
or rather a number of small metallic globules, equal in weight to one-
third of the mineral used. The charcoal, of course, removed the oxygen,
and the manganese remained in the metallic state. To purify the button
of manganese, it should be fused again with some pure carbonate of
manganese and borax, The metal has a specific gravity of 7·05, and
presents a grey colour; it is hard and brittle, readily oxidizes when
exposed to the air in the moist state, and decomposes water at the
boiling point, but very slightly, if at all, at ordinary temperatures.
EXPERIMENTS WITH MANGANESE.
First Series.
The equivalent of manganese is 27.6, and it combines with oxygen in
five different proportions, viz. :-
Protoxide of manganese
Sesquioxide of manganese
Peroxide of manganese
Manganic acid
Permanganic acid
•
MnO.
Mn₂03.
MnO2.
MnO₂.
3.
Mn₂O.
Of these, the most interesting is the peroxide, which occurs in nature
under the name of pyrolusite, or black oxide of manganese, and
used largely in the manufacture of chlorine for bleaching purposes, like-
wise in the preparation of oxygen gas; and as both processes are fully
described in the "Playbook of Science," it is unnecessary to repeat
them here.
Manganic acid, although not yet isolated, is known to exist in com-
bination with other bases; and amongst its salts is the manganate of
potash, or "chameleon mineral (KOMnO3), first discovered by Scheele,
who fused together equal parts of nitre and black oxide of manganese,
and dissolving the green compound in water, obtained a fine red solution,
which in consequence of presenting a green colour when made with
boiling water, and a purple or red with cold, likewise changing by acids
from green to rose or red colour, was named after the extraordinary
animal already alluded to.
462
MANGANESE.
Manganic acid is a powerful oxidizing agent, and in contact with
organic matter is quickly converted into the sesquioxide of manganese.
Permanganic acid (Mn,O,) is prepared by first carefully mixing
together four parts of powdered black oxide and three and a half of chlorate
of potash, to which five parts of potassa fusa, or stick potash, dissolved
in just enough water to make a paste with the other ingredients, are
added. The paste is then dried in an oven, and fused in a crucible for
one or two hours, and when cold is dissolved in water and allowed to
settle in a well-stopped bottle, and the clear solution decanted and
evaporated at a very low temperature, when crystals of the permanganate
are obtained. Lately, Machuca has carefully analysed the permanganate
of potash, and his researches not only prove the existence of the acid,
but the truthfulness of the formula KÕмn,O,.
The oxidizing powers of this acid are truly remarkable; and by
making a standard solution of the permanganate of potash, Dr. Smith,
of Manchester, has detected organic matter in the air. It is this salt,
mixed with the manganate of potash, which is the basis of Condy's
disinfecting fluid, a most excellent deodorizer, and satisfactory in its
result, because the operator can always tell when it has done its work
by the solution becoming colourless. Amongst the recommendations of
the patentee in the use of Condy's fluid is the following:-Pour one
wine-glassful of the concentrated fluid into a hogshead of offensive
drinking-water, and stir it up with a stick or lath; generally this quantity
will render it as sweet as fresh water. Should it be so bad as to require
another half wine-glassful, let it be added, and when the sesquioxide of man-
ganese has settled it may be run off and drank, or if filtered after the addi-
tion of the permanganate, will be found as sweet and good as fresh water.
Mr. Wildsmith, analytical chemist, of Wolverhampton, has made the
permanganate in large quantities, and states that it can be sent into the
market at 150 per cent. below its former rate. Mr. Horsley states
that the powdered black oxide of manganese is likewise an excellent
disinfectant; and he states that a most powerful and cheap deodorizer is
obtained by mixing three parts of the black oxide and one of chloride of
lime. The use and value of manganese, in conjunction with iron, in the
manufacture of the best steel, has been already alluded to.
Second Series.
Manganese is detected by the colour it produces when oxidized with
nitre or chlorate of potash and dissolved in water; and by the precipitation
of the sesquioxide of manganese of a brownish-black colour, on the addition
of organic matter.
The protosalts of this metal are not precipitated by sulphuretted
hydrogen, except from alkaline solutions.
Sulphide of ammonium throws down from protosalts the sulphide of
manganese (MnS), as a bright flesh-coloured precipitate.
Potash and ammonium precipitate protosalts as a white hydrated
protoxide, which gradually changes from white to brown and brownish
TESTS FOR MANGANESE.
463
black by exposure to the air. The reactions of the hydrated oxide are
taken advantage of in dyeing and calico printing.
Any salt or compound of manganese fused with carbonate of soda, on
a platinum wire loop in the outer flame, affords a green colour as long
as the little bead of soda is hot, but when cold it changes to a bluish
green, and becomes opaque. Borax and phosphate of soda and ammonia
dissolve the compounds of manganese in the outer flame of the blow-
pipe, and produce bright violet-red glasses, which, on cooling, appear of
an amethystine red tint; these, however, lose their colour when subjected
to the inner part of the blowpipe flame, owing to a change in the condi-
tion of oxidation, by which the peroxide of manganese is changed to the
protoxide. If an excess of peroxide of manganese is fused with borax,
the glass bead is black; hence the use of this cheap compound of man-
ganese, not only in whitening, but also in conferring a black colour on
some kinds of glass. The glass bead formed in the loop of platinum
wire by melting oxide of manganese with phosphate of soda and am-
monia never dulls or loses its transparency.

Fig. 245. Manganese Compound, fused on a loop of platinum wire with phosphate
of soda and ammonia, which is sometimes called microcosmic salt.

Fig. 246. View in the Hartz Mountains, from whence numerous kinds of
minerals are obtained,
CHAPTER XXIV.
MOLYBDENUM.
NEARLY every mineral cabinet contains a specimen either of molybde-
nite, the sulphide of the metal; or of molybdate of lead, called wulfenite.
The following is the composition of molybdenite, according to
Brandes:
Molybdena
Sulphur
59.6
40.4
Domeyko has given the analysis of wulfenite, or molybdate of lead from
Chili, which consists of-
Protoxide of lead
Molybdic acid
Peroxide of iron
Lime
43.0
42.2
8.5
6.3
100.0
PROPERTIES OF MOLYBDENUM.
465
This rare metal may be procured either by decomposing molybdic
acid at a white heat with hydrogen, or by exposing it to the intense
heat of a wind furnace in a crucible lined with charcoal. Thomson re-
marks, that hitherto the metal has been obtained only in small grains or
in pieces imperfectly agglutinated, and which break readily when struck.
Its colour, from the observations of Bucholz, seems to be a silvery white,
but it frequently has a shade of yellow. Hjelm found its specific gravity
only 7.400; but Bucholz, whose specimens had doubtless been exposed
to a more violent heat and were more compact, found it as high as
8.615, or even 8.636. Molybdenum is brittle. It is not altered,
even if kept under water. Its affinity for oxygen is not great. Hence
it is not liable to undergo alteration when exposed to the atmosphere.
When the metal is heated to redness in an open vessel, it absorbs
oxygen, and is converted into a brown powder, which becomes reddish
if the heat be long continued, and at last, according to Bucholz, becomes
blue. When the heat to which the metal is exposed is still higher, the
molybdenum takes fire and burns without flame, smokes, and deposits
small, brilliant, white needles, which constitute molybdic acid.
Very little is known about the metal, and it is interesting to the chemist
because it forms with oxygen another metallic acid, molybdic acid, com-
posed of three equivalents of oxygen and one of molybdenum (MoO3),
likewise a binoxide (MoO), and protoxide (MoO). Phosphoric acid
appears to be one of the most conclusive tests for this metal, although
a thorough practical knowledge of its behaviour with this and other
reagents is necessary in order to enable the chemist to discover its pre-
sence, and not to lose sight of this element, should it come accidentally
before him.

Fig. 247. The Coast of Cornwall, being one of the localities where molyb
denite is found.
H H

Fig. 249. Aerolite, or Meteoric Stone, in British Muscum.
CHAPTER XXV.
NICKEL.
Tuis metal introduces to our notice what Humboldt terms "an enigma-
tical class of bodies," called minute "asteroids," "acrolites," or "meteoric
stones,”-travellers that come to us out of space, fortunately at rare inter-
vals, but of whose permanent visits to this globe there cannot be any doubt.
These metallic masses chiefly consist of iron, and have usually been dis-
tinguished by scientific men from other natural ores of iron in conse-
quence of their containing nickel; although it ought to be understood
that they include in their composition, according to the analyses of Ber-
METEORIC STONES.
467
zelius, the same elements that are usually found in the crust of the
earth-viz., iron, nickel, cobalt, manganese, chromium, copper, arsenic,
tin, potash, soda, sulphur, phosphorus, and carbon, being rather less
than one-fifth of the number of elements already known. A great many
theories have been suggested to account for these strange mineral
truants, who leave their usual path and turn aside to the earth. Some
astronomers have asserted that they are projected from volcanoes in the
moon; but Humboldt, in his "Cosmos," remarks that, "It is probable
that the different streams of meteors, each consisting of myriads of
small cosmical bodies, intersect the orbit of the earth in the same way
that Biela's comet does. According to this view, we may imagine that
they form a continuous ring, each pursuing its course in a common
direction. The small planets between Mars and Jupiter present, with
the exception of Pallas, an analogous arrangement in their closely-con-
nected orbits.
The highly ingenious Olbers was inclined to
think the next return of the great phenomenon of fire-balls and shooting
stars, falling like flakes of snow, would be witnessed from the 12th to
the 14th November, 1867." The instances of the fall of these solid
masses are very numerous: thus, on the 16th September, 1843, a large
aërolite fell at Kleinwenden, not far from Mulhausen, accompanied by a
thundering noise, but with a clear sky in which no cloud was formed. In
another case, a small and very dark cloud formed suddenly in a perfectly
clear sky, and the stones were hurled from it with a noise resembling
repeated discharges of cannon. Such a cloud, moving over a whole dis-
trict of country, has sometimes covered it with thousands of fragments,
very various in size but similar in quality. Humboldt further remarks:
They exhibit, on the whole, a general unmistakeable resemblance to one
another in their external forn, in the nature of their crust, and in the
chemical composition of their principal constituents; and this resem-
blance is traceable when and wherever they have been collected, at all
periods of time, and in all parts of the earth." In the Lithuanian
mythology a beautiful symbolical meaning has been attached to these
"falling stars." The new-born infant's destiny was supposed to be
attached by a thread to a star, and when it fell the child died, and the
thread was broken for ever. In consequence of the density of their
chemical composition, they have been divided into two classes, viz.—
Nickeliferous meteoric iron.
Fine or coarse-grained meteoric stones.
Enough, then, has been said to prove that one of the sources of
nickel is to be found in the aërolites that wander in space; but as this
nickel happens to be rather largely used just now for the whitening
agent in the manufacture of nickel silver, or German silver, it would
not be a very profitable or prudent course to wait, like fags at cricket,
till the balls containing it come to hand; so the diligent miners seek for
it in the earth, and are rewarded with certain minerals that contain it:
viz.—
X X 2
468
NICKEL.
Name.
Copper nickel, or kupfer nickel.*
Antimonial nickel.
Nickeline, or nickel ochre, or
nickel arseniate
Chrysoprase,
quartz.
Composition.
Nickel, cobalt, arsenic with a little
iron, lead, antimony and sulphur,
but no copper.
Nickel, antimony, sulphur, arsenic,
with occasionally a little iron.
Oxide of nickel, arsenic acid, sul-
phuric acid, oxide of cobalt, oxide
of iron, water.
a variety of í About one per cent. of the oxide of
nickel.
Solutions of nickel are specially distinguished by their peculiar grass-
green colour, and if precipitated by oxalate of ammonia, an oxalate of
nickel is obtained, which, if it contains cobalt, must be dissolved in
ammonia; and being left to evaporate spontaneously, the nickel is de-
posited as the ammonio-oxalate, whilst the cobalt remains in solution.
When this ammonio-oxalate has been thoroughly dried, it is placed in
a closed plumbago crucible, and exposed to the strong heat of a wind-
furnace, by this means the carbon and oxygen of the oxalic acid are
converted into carbonic acid, which passes away, and the nickel remains
behind in the metallic state.
In a state of purity, nickel is of a beautiful white colour, brilliant,
and, like silver, leaves a mark on the touchstone: it has a specific
gravity of 8.5, and its equivalent is 29.6. Nickel is malleable both hot
and cold, and, like cobalt, is attracted by the magnet; and nickel needles
may be constructed, magnetized, and suspended like ordinary steel ones.
This metal forms poisonous salts, and therefore "German silver"
articles must never be exposed to vinegar or other acid matter, and
should be kept scrupulously bright and clean. Oxide of nickel (like
the oxides of iron, copper, &c.), when heated and exposed to a current
of dry hydrogen gas, is reduced to a pyrophoric metallic state: it is
stated that when heated, nickel passes through nearly the same phases
of colour which are perceptible if steel is tempered. In a lecture
delivered by Dr. Percy, on "The Importance of Special Scientific
Knowledge to the Practical Metallurgist," at the Government School of
Mines, he stated that-
It is only a few years ago that, in respect to commercial value,
nickel occupied much the same position as tungsten, but now it is
worth eight shillings a pound, or about ten times more than copper.
It is the whitening constituent of the alloy known as 'German silver.'
The silver-platers who practise the old method of plating by soldering,
as well as those who deposit the silver by the agency of voltaic elec-
tricity, employ this alloy extensively, the advantage being, that when
the silver is worn from any part of an article, the alloy beneath suffi-
The name of this mineral is the origin of the word nickel. "Kupfer nickel" means
false copper, because the miners at first mistook it for that metal, and threw it away as
useless, when unable to extract any copper from the mineral.
EXPERIMENTS WITH NICKEL.
469
ciently approximates to silver in whiteness as to deceive the eye
respecting the wear. Some years ago, a compound of nickel, termed
pottery nickel, was obtained in the manufacture of compounds of
cobalt, for the use of the potters, which was sold as low as three-
halfpence a pound, whereas it would now fetch about three shillings
and sixpence."
The late Mr. Henry Bradbury, who distinguished himself so highly in
the perfection of the printing process termed "nature printing," has
found that by depositing nickel on the surface of copper or steel
engraved plates, they last an indefinite period if occasionally re-nickelized
by the voltaic current in a bath containing a solution of the sulphate
of the protoxide of nickel in ammonia.
EXPERIMENTS WITH NICKEL.
First Series.
There are two oxides of nickel-—viz., the protoxide, NiO, and the
sesquioxide, Ni,O,, and when a solution of potash or soda is added to
one of the protoxide of nickel in sulphuric acid (that being the acid which
appears to be the best solvent of the metal), a beautiful light apple-
green precipitate is thrown down, being the hydrated oxide, NiO,HO.
Nickel dissolves in nitric acid, and by evaporating the solution and
calcining the residue at a moderate heat, there remains behind the
sesquioxide of nickel.
Second Series.
Copper plates, as already observed, may be coated with nickel, and
in that state exercise a curious influence upon the magnetic needle.
Boettgher states that copper plates assume a silvery-white shining
surface after exposure to a long-continued and constant galvanic action
in a solution of the ammonio-sulphate of nickel, and, when covered, they
have sufficient magnetic power to bring a magnetic needle suspended
by a thread of raw silk out of the meridian. A drop of concentrated
nitric acid placed on a coating of nickel gives no evidence of reaction on
the metal below it, whilst a copper plate covered with gold in the same
space of time is strongly acted upon by the acid. As pure nickel is as
difficult to melt as iridium or manganese, and is, in fact, not to be
fused except by the oxyhydrogen blowpipe, this metal, procured in the
pure state (in the form of plate) by voltaic deposition, might be used
for the construction of magnetic needles, &c.
Third Series.
In the chapter on the metal Tin, the preparation of "mosaic gold,"
by distilling an amalgam of tin and mercury with sulphur and sal
ammoniac, is fully described. The chloride of nickel, NiCl, has a some-
what similar appearance to "mosaic gold," and is prepared by passing
chlorine gas over nickel at a red heat, when it sublimes in fine plates of
470
NICKEL.
a beautiful golden yellow colour; which if heated to redness in hydrogen
gas, afford brilliant metallic nickel.
Fourth Series.
Solutions of nickel are nearly always green. The protoxide is pre-
cipitated by ammonia as a lovely apple-green hydrated oxide, which is re-
dissolved by an excess of the precipitate, and then turns blue.
Cyanide of potassium throws down a greenish-white precipitate of
cyanide of nickel, NiCy, which is dissolved by an excess, and then
forms a brown-coloured solution; but the original greenish-white,
NiCy, reappears on the careful addition of an acid. In all experiments
with the cyanides, and whenever acids are added to them, care must
be taken not to inhale the hydrocyanic acid (prussic acid) fumes given
off. More than one instance has occurred in olden times where the
alchemist was found dead in his laboratory, killed by the poisonous
exhalation of his experiments. Scott disposes of Alasco (in his novel of
"Kenilworth") by this mode of retributive justice. The glass and its
contents, placed on a piece of wood, or any other bad conductor of heat,
may always be placed on one of the hobs of an ordinary fireplace, and
the current of air which sets towards the fire will generally sweep it up
the chimney.

Fig. 249. Mode of avoiding Dangerous Fumes.
CHAPTER XXVI.
NIOBIUM, NORIUM, OSMIUM.
WITH respect to niobium and pelopium-and we mention this metal
out of the alphabetical order because of its association with niobium in
the same mineral-Professor H. Rose says: "I have discovered in
the tantalite of Bavaria two new metals: one I have called Niobium,
and its acid, niobic acid, from Niobe, the daughter of Tantalus, a
name which calls to mind the resemblance between the two metals
and their oxides; and the other, Pelopium, from Pelops, the son of
Tantalus, and the brother of Niobe. For more than four years I have
been engaged in investigating the tantalites from various localities, and
the tantalic acid derived from them." And it was by the searching
examination of that which was supposed to be wholly tantalic acid, that
these metals were eliminated in minute quantities. Niobic acid is said
to resemble titanic acid and the binoxide of tin; both of these, when
calcined in the hydrated state, present the same luminous phenomenon.
Pelopic acid also resembles tantalic acid.
Norium, the existence of a new earth in Zircons, was first pointed
out by L. Svanberg; and, by analogy, if a new earth, it must have a new
metallic base, called Norium, from Nore, the old name of Norway; but
the existence of this new metal seems doubtful.
Osmium.―This metal has already been alluded to in connexion with
iridium, page 455, and it forms at least five compounds with oxygen
gas, of which osmic acid is represented by the formula, OsO. The
equivalent of the metal is 99.6, and specific gravity 10. It is stated
to be a brittle metal having a greyish appearance, but when obtained
in the metallic state from its solutions, osmium has a blue colour.
These remarks on the colour and general appearance of the metal must
probably be received with caution, because it is difficult to form any
judgment of these points until a tolerably-sized bar of any new metal is
obtained. The peculiar smell and the volatility of the osmic acid in
the treatment of ores containing platinum are very marked, and it is
from this peculiar circumstance that the metal osmium derives its name.
Osmic Acid (Os0,).-This metallic acid appears to possess very
feeble powers of combination, and is incapable of reddening litmus-
paper or decomposing the carbonates of the earths or alkalies; still the
vapours of osmic acid have always enjoyed a very bad reputation, and
are stated to be extremely hurtful and irritating to the lungs of those
who have performed experiments with it. Osmic acid is prepared by
heating osmium with nitric acid in an alembic or retort; the vapours
pass over with those of the nitric acid, and the osmic acid condenses in
colourless prismatic crystals, which melt and sublime some degrees
below 212° Fah. The chief source of osmium is from the alloy of
iridium and osmium (osm-iridium), which is associated in nature with
native platinum.

Fig. 250. Portrait of Sir Humphry Davy, the Discoverer of the Alkaline Metals.
CHAPTER XXVII.
POTASSIUM.
IN 1807 the scientific world of Europe was gratified with the fulfilment
of the prediction, that the bases of the fixed alkalies and earths were
metals, by the ingenious experiments of Sir H. Davy, who discovered
that potash can be resolved by an intense and powerful current of
voltaic electricity into potassium and oxygen. The battery used consisted
of two hundred pairs of four-inch plates; but the late Dr. Golding Bird
devised a very simple arrangement with a single pair of elements, and
decomposing cell, which will effect the same object as that obtained by
Davy with his large battery. The single cell consists of an inner vessel,
BIRD'S MODE OF MAKING POTASSIUM.
473
B B, which may be an inverted lamp-glass closed at one end with plaster
of Paris, seven-tenths of an inch in thickness, suspended by a wire
(twisted round the shoulder) inside a sufficiently deep jar, ▲ ▲. In the
latter is placed a sheet of zinc with wire attached, z, and some weak

B
B
F
F
A
A
D
D
Z
Fig. 251. AA. Outer vessel of the single-pair battery, containing a zinc plate
and a solution of common salt. B B. Inverted lamp-glass closed at the bottom
with plaster of Paris, and containing a copper plate, c, surrounded with a satu-
rated solution of sulphate of copper. D D. Outer vessel or decomposition cell,
containing a weak solution of common salt and amalgamated plate of zinc, z.
F F. The funnel closed with plaster of Paris, and holding the little cup of mercury
covered and surrounded with a solution of chloride of potassium, P. G. Connecting
wire.
solution of common salt, and in the lamp-glass is placed a sheet of
copper, c, and wire attached of the same size as the zinc, surrounded
with a saturated solution of sulphate of copper. The two liquids must
be at the same level in each glass. The decomposition cell is the ditto
of the miniature battery, and it consists of an inner vessel, such as a
glass funnel, which is closed at the tube or narrow end with plaster of
Paris, likewise seven-tenths of an inch in thickness, and contains a short
glass tube, like a thimble, full of mercury, and the whole covered with
a solution of chloride of potassium; the funnel is supported in an
outer vessel containing a weak solution of common salt. In the latter
solution is placed a slip of amalgamated zinc soldered to the wire coming
from the copper plate of the miniature battery, and a platinum wire, P,
coiled into a spiral at the extremity, is connected with the wire from
the zinc plate of the little battery, and placed in the mercury contained
in the short glass tube standing in and covered with the chloride of
potassium in the funnel. After the circuit had been completed and
maintained for nine hours, the mercury was found by Dr. Bird to have
puffed up to twice its former bulk, and when this amalgam of mercury
and potassium was thrown into water, it evolved hydrogen and produced
an alkaline solution, just as potassium acts in the ordinary manner.
474
POTASSIUM.
Potassium is obtained by the improved process of Mitscherlich, by
exposing black flux, which is a mixture of charcoal and carbonate of
potash, and lumps of charcoal, in a wrought-iron mercury bottle, to which
an iron tube and copper receiver containing petroleum, and surrounded
with ice, is attached. At the proper heat the metal distils over, and
falling into the mineral naphtha is preserved from oxidation. After re-
distillation, it is found to be sufficiently pure, and is a soft solid at all
ordinary temperatures, having a specific gravity of 0.865, water being
1.000. When cut with a knife, it exhibits considerable brilliancy and
looks like lead, but is quickly dimmed over with the rapid oxidation
and formation of potash (the oxide of potassium) on its surface. The
vapour of potassium, like that of chlorine, is green. The most important
oxide is potash, KO, always obtained when potassium is burnt on the
surface of water; but there is probably a suboxide, K₂O, and a teroxide,
KO,, is also believed to exist.
Potash is one of the most important of the fixed alkalies, forming, with
various acids, salts, such as nitre, carbonate of potash, chlorate of
potash, ferrocyanide of potassium, and chromate of potash, &c., which
are of the highest commercial value. Nitre, saltpetre, or nitrate of
potash (KO,NO), is a salt which is produced spontaneously, and comes
out as a sort of efflorescence on the surface of the soil in certain hot
climates. It has been calculated that the soils of Spain, Egypt, and
India might supply the whole world with this substance, and it is ex-
tremely satisfactory to feel that, as gunpowder is likely to be required
in large quantities for those wars with which Europe is threatened,
we hold possession of India, and have therefore a boundless supply of
the "villanous saltpetre."
The superficial earth containing the nitre is broken up and thrown
into large cisterns provided with false bottoms covered with straw,
which act as the strainer does in a coffee-pot. These cisterns are
usually arranged in a succession of steps or levels, so that the water
poured upon the first quantity of the earth containing the nitrates may
remain upon it for twelve hours, and then be run off (without the
trouble of lifting or pumping) into the next lower cistern, also containing
the nitre earth, and from that into the third or lowest cistern, likewise
containing a quantity of earth. By this simple method the solution is
made tolerably strong, and is usually termed the lye. This liquid, which
not only contains the nitrate of potash or saltpetre, but also nitrates of
soda, ammonia, lime, and magnesia, is now mixed with a strong solution
of carbonate of potash or pearl-ashes, and sometimes with sulphate of
potash, and allowed to stand till clear. The clear solution is then run
off into boilers, and rapidly evaporated. During this process many of
the impurities, such as common salt, chloride of potassium, sulphate and
carbonate of lime deposit, and when the liquor in the boiler has reached
a certain strength, it is drawn off into other large pans, and kept at a
temperature of about 123° Fah., when a further crystallization of the
impurities takes place. Finally it is run off into other vessels, allowed
to cool, and the saltpetre then crystallizes. The impure crystals are

THE SOURCE OF POTASH.
475
re-dissolved in water, boiled with glue to separate any organic matter,
and, after filtration, placed in vessels, where the strong solution is con-
stantly agitated with wooden stirrers to break up the large crystals and
form only small ones, which shall retain the very smallest proportion of
interstitial water.
One of the best tests for potash is the insoluble compound of cream
of tartar or bitartrate of potash, which it forms with tartaric acid; it
is also precipitated in conjunction with platinum, as the bichloride of
platinum and chloride of potassium, KCl,PtCl,, when bichloride of
platinum and hydrochloric acid are added to a solution containing
potash.
Fig. 252. Cutting down and burning Forest Trees, in order to collect the ashes
for lixiviation, and manufacture of pearl-ashes or crude carbonate of potash; thus
showing that potassium is characteristic of the land plants, as sodium is of the
marine plants or sea-weeds.

Fig. 253. Portrait of Wollaston.
CHAPTER XXVIII.
PLATINUM.
PLATINUM is obtained from native platina, which occurs in obtuse-
angled grains, with smooth, shining surfaces, and contains, besides pla-
tinum, also palladium, rhodium, iridium, osmium, iron, copper, likewise
osm-iridium, and sometimes manganese. It was this complicated
mineral which the great Dr. Wollaston attacked with his usual
talent, and not only succeeded in climinating platinum, but like-
APPLICATIONS OF PLATINUM.
477
wise all the other metals above named. The examination of this
mineral offers one of the most interesting subjects of analysis that the
advanced student of chemistry can possibly desire; and by consulting
either the tables of Dr. Griffin, of Bristol, or those of Dr. Normandy,
of London, he may master the principles upon which this examination
may be successfully conducted.
The metal is usually obtained, by precipitating a solution of platinum
in aqua regia (after separation from the other metals contained in native
platina), by chloride of ammonium; a double chloride of ammonium and
platinum is obtained, which is converted into a porous mass, called
"spongy platinum," after being heated red-hot. The porous metal is
gradually brought by compression into a compact brilliant white mass,
which may be forged, welded, and hammered like iron, provided a
sufficiently high temperature is employed. Platinum has the greatest
specific gravity known-viz., 21-5; it is remarkably malleable, ductile,
and tenacious, and is of the greatest value in the laboratory, being
used in the manufacture of crucibles, spatulas, grain and fractions of a
grain weights and now that it can be melted and cast by the econo-
mical use of the intense heat of the oxyhydrogen blowpipe, no doubt
many parts of the delicate mechanism of clocks and watches will be
made with it. This metal is used for the nipples of rifles and other
fire-arms, and is likewise employed, on account of its difficult fusibility,
for the jet pieces of the oxyhydrogen blowpipe. Platinum stills, which
may cost from 900l. to 1500l. pounds sterling, are employed in the
final concentration of oil of vitriol.
The author's respected teacher, the late John Thomas Cooper, in-
vented the platinum lustre for china, and formed an alloy of 1 part zinc,
16 copper, and 7 parts platinum, by fusing together under borax the
copper and platinum, and finally adding the zinc, and well stirring the
whole after its removal from the fire. This alloy is very ductile, is not
readily attacked by nitric acid, and very much resembles in colour and
weight pure gold.
If platinum and tinfoil are rolled together and held in the flame of a
spirit-lamp, they alloy or unite instantaneously, with the production of
a sudden flash of light and intense heat, which is very remarkable, and
offers another illustration of the theory that metals unite chemically with
each other in certain definite proportions.
EXPERIMENTS WITH PLATINUM.
First Series.
The equivalent of platinum is 987, and it forms two oxides-viz.,
the protoxide, PtO, and the binoxide, PtO,. This metal is not attacked
by pure hydrochloric, sulphuric, or nitric acids, either hot or cold; but is
readily dissolved by aqua regia, and if the solution is carefully evaporated
with an excess of hydrochloric acid, leaves the bichloride of platinum,
PtCl, which is converted into chloride, PtCl, when carefully heated at
a temperature of 400° Fah., until no more chlorine is given off.
478
PLATINUM.
Second Series.
The mode of preparing spongy platinum has already been described.
Platinum black is obtained by boiling a solution of the bichloride with
sugar and carbonate of soda, constant agitation being used during the
process. The black precipitate, after being thoroughly washed with
boiling distilled water, may be dried spontaneously on blotting paper.
When hydrogen gas is projected upon the spongy platinum or black, it
takes fire in consequence of the condensation of the oxygen of the air
in the pores of the metal, and its rapid union with the hydrogen in the
presence of the platinum. The spongy platinum is usually mixed with
pipeclay, and made into little balls, which, if placed in a cage of pla-
tinum wire and heated, may be used in the analysis of air by hydrogen,
and being passed through the mercury of the mercurial trough into the
tube containing the mixed gases, causes the oxygen and hydrogen to
unite and form water.
Dobereiner's well-known hydrogen lamp has long been used as a
rapid means of obtaining a light; and when the spongy platinum belong-
ing to it refuses to act, it must be removed, boiled in nitric acid,
thoroughly washed and gently heated, when it will again cause the hy-
drogen to take fire.
A platinum wire, turned in a spiral form, and placed over the wick of
a spirit-lamp, will continue to glow after the flame is blown out; and
if the lamp is fed with eau de Cologne or tincture of benzoin, and a
little glass tube inserted in the wick, carrying a platinum wire support-
ing a ball of mixed spongy platinum or clay, it will continue to distil
delightful odours into the room until the spirit is exhausted.
Third Series.
Platinum is precipitated from the state of bichloride by salts of
ammonia and potash, forming yellow ammoniochloride of platinum,
NH,CIPtCl₂, and yellow potassiochloride of platinum, KCIPtCl,; hence
the value of solutions of this metal in the detection and estimation of
these important alkalies.
CHAPTER XXIX.
FALLADIUM, PELOPIUM.
PALLADIUM is one of the metals discovered and isolated by Dr. Wollaston
in 1803, and is obtained from native platina by dissolving it in aqua regia,
filtering, evaporating to a syrup, and adding water with cyanide of mer-
cury, when a pale yellowish-white precipitate falls: this precipitate,
washed, dried, and heated strongly, leaves a white matter, which is pal-
ladium. The metal, which is in a spongy state, is then worked into
inasses by pressure in the same manner as platinum.
Palladium is a hard metal of a white colour, and very malleable,
ductile, and tenacious; it may be welded at a high temperature, and
melts like platinum in the flame of the oxyhydrogen blowpipe: its spe-
cific gravity is 11.5, and equivalent number, 53.3. There are two oxides
of palladium, the protoxide, PdO, and the bínoxide, PdO; and although
the mineral acids dissolve it slowly, aqua regia is the true solvent of
this metal. Iodide of potassium precipitates a black iodide of palla-
dium, and cyanide of mercury a yellowish-white precipitate of cyanide
of palladium. The metal is used by dentists when alloyed with silver,
and the author has seen graduated arcs of astronomical instruments and
balances which were made of palladium, and likewise portions of
chronometers.
Formerly the only source of palladium was the native platina already
alluded to, but, as Mr. Cock has shown,*—
"Of late years, however, the importation into this country from
Brazil of gold dust, alloyed with palladium, has occasioned a much
more extensive supply of this metal, as it exists in some specimens of
gold dust to the extent of five or six per cent., and in one instance
(that of gold from the Candonga mine) it constitutes the only alloy of
the gold.
The operation of refining is conducted in the following manner.
The gold dust is fused in charges of about 7 lbs. troy, with its own
weight of silver, and a certain quantity of nitrate of potash; the effect
of this fusion is to remove all earthy matter and the greater part of the
base metal contained in the gold dust and in the silver melted with it.
The fused mixture is cast into ingot moulds, and, when cooled, the flux
or scoria (containing the oxides of the base metal, and the carthy mat-
ter, combined with the potash of the nitre) is detached. Two of the
bars thus obtained are then remelted in a plumbago crucible, with such
* "Memoirs of the Chemical Society," vol. i. p. 161.
480
PALLADIUM.
an addition of silver as will afford an alloy containing one-fourth its
weight of pure gold, and which, being first well stirred to ensure a com-
plete mixture, is poured through a perforated iron ladle into cold water,
and thus very finely granulated; it is then ready for the process of
parting. For this purpose about 25 lbs. of the granulated alloy is
placed in a porcelain jar upon a heated sand-bath, and subjected to the
action of about 25 lbs. of pure nitric acid, diluted with its own bulk of
water. After the action of this quantity of acid, the parting of the
gold is very nearly effected; but, to remove the last portion of silver,
&c., about 9 or 10 lbs. of strong nitric acid are boiled with the gold for
two hours. It is then completely refined, and after being washed with
hot water, is dried and melted into bars containing 15 lbs. each.
"The nitrous acid gas, and the vapour of nitric acid, arising during
the above process, are conducted by glass pipes (connected with the
covers of the jars) into a long stoneware pipe, one end of which slopes
downwards into a receiver for the condensed acid, the other end being
inserted into the flue for the purpose of carrying off the uncondensed
gas.
"The nitrate of silver and palladium obtained as above is carefully
decanted into large pans, containing a sufficient quantity of solution of
common salt to effect precipitation (as a chloride) of the whole of the
silver, the palladium and copper remaining in solution in the mother
liquor, which is drawn off, together with the subsequent washings from
the chloride of silver, into wooden vessels; and the metallic contents
are then separated, in the form of a black powder, by precipitation with
sheet zinc, assisted by sulphuric acid.
"The chloride of silver, when washed clean, is reduced by the ad-
dition of granulated zinc, washed on the filter with boiling water, dried,
and melted in plumbago crucibles without the addition of any flux.
From the black powder obtained as above, the palladium is extracted by
re-solution in nitric acid, and super-saturation with ammonia, by which
the oxides of palladium and copper are first precipitated and then re-
dissolved, while those of iron, lead, &c., remain insoluble. To the clear
ammoniacal solution, muriatic acid is then added in excess, which
occasions a copious precipitation of the yellow ammonio-chloride of
palladium; from which, after sufficiently washing it with cold water,
and ignition, pure metallic palladium is obtained. The mother liquor
and washings contain all the copper and some palladium, which are
recovered by precipitation with iron.
Pure palladium is of a greyish-white colour, rather darker than that
of platinum; it is both malleable and ductile, though inferior in those
qualities to pure platinum; its specific gravity is 11.3, which may be
raised by hammering or rolling to 11.8. When perfectly pure, it cannot
be fused, even in small quantities, in an ordinary blast furnace, but may
be brought into such a state of agglutination as to bear laminating or
drawing into wire.
"It may be completely fused by means of oxygen gas, and being kept
some time fused, is said to burn with the production of brilliant sparks.
PELOPIUM.
481
It is not tarnished by exposure to sulphuretted hydrogen, nor oxidated
by the air at the ordinary temperature, or at bright red heat; but it has
the singular property of becoming oxidated by exposure to air at a dull
red heat, the surface becoming coloured in the same manner as iron or
steel; and by continuing the process cautiously for some time, the
metal becomes coated with a brittle crust of oxide of a brown colour;
this oxide is, however, reduced by a temperature very little higher than
that necessary for its formation; and the surface of the metal regains
its original colour upon being heated to a bright red, and cooled out of
contact with the air.
It is with difficulty soluble in nitric acid, when pure and fused, or
in a state of aggregation; but is readily so when alloyed to some extent
with silver or copper, and still more so when in the form of the black
powder above referred to, in which state it is also soluble with the aid
of heat in sulphuric and muriatic acids; but its proper solvent is nitro-
muriatic acid, which, if it be not very much alloyed with silver, dissolves
it readily.
It is, of all the metals, that which has the greatest affinity for cyan-
ogen; and by means of cyanide of mercury it may be separated from
all its solutions. It may be alloyed so as to be malleable with gold,
silver, and copper, several of its alloys with the two latter metals being
of great use in the arts, from their hardness and elasticity, and non-
liability to rust or tarnish. When added to gold or copper, it whitens
both those metals in a very great degree, about 20 per cent. being suf-
ficient in either case to destroy their colour. The uses to which the
alloys of palladium have been applied are for the points of pencil-cases,
for lancets for vaccination, for graduated scales of instruments, as a
substitute for gold in dental surgery, or for any purpose where strength
and elasticity, or property of not tarnishing, is required."
Pelopium has already been alluded to at p. 471, in connexion with the
metals obtained from tantalite, and is not at present regarded with any
interest, except by scientific chemists. It unites with oxygen, and forms
a metallic acid, which contains three equivalents of oxygen, and is
termed pelopic acid; this compound is said to be very like tantalic acid,
and unites with other bases, forming pelopiates. By heating a mixture
of pelopic acid and charcoal in a porcelain tube, and passing chlorine
gas over them, the chloride of pelopium is obtained. The sulphide of
pelopium may also be procured by heating pelopic acid in sulphuretted
hydrogen gas.
1
CHAPTER XXX.
RHODIUM, RUTHENIUM.
RHODIUM is another of the metals discovered by Wollaston in 1804,
and likewise obtained from native platina. It is very like platinum in
appearance, is brittle, and so hard, that when used for the purpose of
making the nibs of gold or silver pens, the lapidaries who grind it
complain of the hardness as injurious to their working tools.
Rhodium has a specific gravity of 106, and its combining proportion
is 52.2, and is remarkably infusible, being only rendered pasty by the
oxyhydrogen blowpipe. There are two oxides-viz., the protoxide,
RhO, and the sesquioxide, Rh,O,. It is not dissolved by the mineral
acids, and even resists the powerful action of aqua regia, unless the
rhodium is first alloyed with some other metal. The insolubility of
rhodium in aqua regia and the effect of bisulphate of potash upon it,
which is coloured pink, and attacks the metal, are to be considered as
distinguishing characteristics of this metal.
Ruthenium was discovered by Professor Claus in 1845, and likewise
exists in native platina; it is a very rare metal, and of no practical
importance at present. Claus describes it as a blackish-grey powder, and
calls it ruthenium because it occurs in small quantities in the white
body described by Osann, which consists principally of silica, titanic
acid, peroxide of iron, and zirconia, and was regarded by Osann as a
peculiar metallic oxide, which he called the oxide of ruthenium.
Messrs. Abel and Bloxam point out a most interesting coincidence
in the equivalents of the following metals just described.
First Group.
Equivalent.
Platinum
98.7
Iridium
99.0
Osmium
99.6
Second Group.
Rhodium
52.2
Palladium
53.3
Ruthenium
52.2

BOHN 49. ESSEX STRECT-STRAND.
Fig. 254. A Sea-water Tank, or Vivarium, copied from one established by Bohn,
Essex-street, Strand.
CHAPTER XXXI.
SODIUM.
In the chapter on silver, it has been shown that certain sea-weeds con-
tain that metal: in the olden time, however, the sea-weed was collected
by all the poor people of the parishes coasting Great Britain, when the
ocean threw up its spoils (made in violent storms) from the otherwise
tranquil meadows of sea-weed. Protected by one of Heinke's diving
dresses, and supplied with air, even human beings might observe for
themselves the appearance of a world, full fathom deep, to which the
drowned mariner only pays his last solemn visit. But this inquisition
is more safely arrived at by gazing into the little pools of water and
sea-weeds left by the receding tide, or at home in the aqua vivaria.
It should have been stated that the sea-wecd was collected and burnt,
and produced an ash called "barilla," which, lixiviated with water, af-
forded carbonate of soda, known familiarly to all who pay their weekly
domestic bills by the name of washing soda.
Sodium was discovered by Davy in 1807, and is procured much in
the same manner as potassium. The carbonate of soda is mixed with
acetate of soda and calcined; the charcoal from the decomposed acetate
II 2
484
SODIUM.
is thus distributed through the mass, which is powdered, mixed with
small lumps of charcoal, and subjected to heat in a wrought-iron bottle.
The metal distils over much more easily than potassium, and is now pre-
pared in large quantities for the preparation of the new metal aluminium.
Sodium is a white metal like silver, extremely soft, so that it is easily
squeezed and moulded in the fingers, or cut with a knife; its specific
gravity is 0.97 and combining equivalent 23. Potassium is pasty at 70°
and liquid at 137°, whilst sodium does not become perfectly fluid until
it reaches a temperature of 194° Fah. Potassium takes fire directly it
touches the surface of water contained in any convenient vessel.
Sodium appears to cool too rapidly in a large quantity of water, but
takes fire easily on well wetted blotting-paper. If an inclined plane is
made with a board a few feet in length, provided with a ledge on
each side, and wet blotting-paper laid upon it (Fig. 255), the sodium

Fig. 255. Globules of Sodium rolling down and burning on the wet Blotting-
paper placed on an Inclined Board provided with ledges at the sides to prevent
the Metal rolling off.
launched at the top rolls down the miniature hill, and, taking fire,
presents a most curious appearance, burning during the time of its
descent with an intense yellow light. In all experiments with potas-
sium and soda on water, care must be taken to avoid the final bursting
of the red hot spheroid of potash or soda, which offers another illustra-
tion of Boutigny's discoveries.
Sodium forms two, perhaps three, oxides-viz., soda (NaO), teroxide
of sodium (NaO₂); and possibly a suboxide.
Soda is produced whenever sodium is burnt on water; and as it is
required in large quantities for commercial purposes, and especially in
soap-boiling, it is usually made by boiling together, in a cast-iron pan,
three parts of common crystallized carbonate of soda, fifteen of water, and
one of lime slaked with three of water. This metal, like potassium,
forms the most valuable salts, of which common salt (easily made by
burning sodium in chlorine gas), carbonate of soda, hyposulphide of
soda, sulphate of soda, phosphate of soda, are important examples: in
THE TESTS FOR SODA.
485
fact, the manufacture of soda for glass and soap making, and as a deter-
gent, is second only in importance with that of iron; and is one of those
staple products of industry of which commercial England may be justly
proud. Soda is now made by decomposing common salt; but formerly
it was wholly obtained by burning sea-weed, and collecting and lixiviat-
ing the ashes. The product was called barilla when it came from Spain;
kelp, when made on the coasts of England, Scotland, Ireland, and
Wales.
Soda is precipitated in a white crystalline state in combination with
antimonic acid (SbO,) as the antimoniate of soda (NaO,SbO), provided
the solution containing it is slightly alkaline. This test, however, can
only be relied on in the absence of all other oxides.
Periodate of potash (KO,Io,) likewise forms a white precipitate in
concentrated solutions of soda.
The most characteristic test of the presence of sodium is a spirit
flame, which is immediately changed to a yellow light if a piece of paper
moistened with the solution supposed to contain soda is dried and then
allowed to burn in contact with it; and still better if the smoke from
the burning paper is passed up into a wire gauze chimney whilst the
mixed coal gas and air are burning.
As common salt (chloride of sodium) is not only the speciality of the
ocean, but is found in all the secretions of the human body, it is con-
sidered the characteristic of the animal, just as potassium is thought to
represent the vegetable kingdom: at all events, the idea is a good one,
and assists the memory in recollecting the sources of these two most
valuable alkalies.

Fig. 256. Collecting and burning Sea-weed on the Sea-shore for the Manufacture
of Kelp.

ELVANS
Fig. 257. People looking at Fireworks. "Oh!-Oh!!!"
CHAPTER XXXII.
STRONTIUM.
OUR picture demonstrates the chief use of this salt by pyrotechnists, for
the purpose of producing those fiery effects which excite and draw
forth so many admiring and long-sustained "O-hs!" from the British
public.
The metal was proved to exist by the triumphant Davy in 1808, and is
obtained from a mineral which was brought, in 1787, to Edinburgh, by a
dealer in fossils, from the lead mines of Strontian in Argyleshire. Klap-
roth christened the new earth strontian, which is a natural carbonate of
strontium, found abundantly in various parts of the world. It yields a
metal by the same process as that described for barium, p. 435: it is
stated to be white, solid, heavier than water, and presents very much
the same physical characters as barium. Dr. Matthiessen has, however,
MATTHIESSEN'S EXPERIMENTS.
487
shown, in his paper on the preparation of strontium and magnesium*-
"that strontium resembles calcium in colour (a light yellow, like that
of gold alloyed with silver), being only a shade darker. It oxidizes
much more quickly than that metal. The specific gravity of the metal
obtained from pure chloride of strontium gave, in two experiments,
2.5041 and 2.5796; the mean of which is 2.5418. Its atomic volume is
216, being one and a half greater than that of calcium. The specific
gravity of calcium from pure chloride of calcium gave, in three expe-
riments, a mean of 1.5778, and its atomic volume is 158. Strontium
burns like calcium, and also acts similarly to it when heated in chlorine,
oxygen, bromine, or iodine, or on boiling sulphur, or when thrown into
water or acids. The best method, by which pieces weighing half a
gramme are sometimes obtained, is as follows:-A small crucible, with
a porous cell, is filled with the anhydrous chloride of strontium, mixed
with some chloride of ammonium, so that the level of the fused chloride
in the cell is much higher than in the crucible. The negative pole
placed in the cell consists of a very fine iron wire wound round a
thicker one, and then covered with a piece of tobacco-pipe stem, so that
only about the one-sixteenth part of an inch appears below; the posi-
tive is an iron cylinder placed in the crucible round the cell. It is easy
to regulate the heat during the experiment, so that a crust may form in
the cell; the metal will then collect under this crust, without coming
in contact with the sides." Dr. Matthiessen states that he has found
this method very advantageous also for the preparation of calcium.
Strontia unites with oxygen in two proportions, forming strontia
(SrO), and binoxide of strontia (SrO₂).
Strontia forms with nitric acid the nitrate of strontia, which is the
salt employed in pyrotechnic compositions; and as the proportions for red
fire are given in the "Playbook of Science," they need not be repeated
here.
Both strontian and baryta are detected when in solution by sulphuric
acid, which forms with these earths sulphates insoluble in acids and
alkalies.
Strontium is distinguished from baryta by the carmine-red colour it
imparts to a spirit or diluted gas flame. Baryta affords a green colour.
Hydrofluosilicic acid (3HF,2SiF,) does not precipitate strontian, and
therefore serves, like the flame test, to distinguish it from baryta, which
forms with this acid a white precipitate that gradually becomes crys-
talline.
• "Quarterly Journal of the Chemical Society," vol. viii. p. 107.

www
Fig. 258. The Alchemist, the Model of patient Investigation.
CHAPTER XXXIII.
TANTALUM, TELLURIUM, TERBIUM, THORIUM, TITANIUM.
TANTALUM is obtained from tantalite, a mineral which occurs in Fin-
land, and contains, according to the analysis of Berzelius-
Tantalic acid
83-2
Protoxide of iron
7.2
Protoxide of manganese
Oxide of tin.
7.4
0.6
Loss.
1-6
100.0
It was from the tantalic acid, stated in the above analysis, that Rose
obtained niobic and pelopic acids, the oxides of two new metals already
incntioned.
RARE METALS.
489
Tellurium.-The properties of this metal are fully known and de-
scribed; and in 1798 Klaproth gave it the name of tellurium, which
had been called by Kirwan, in 1796, sylvanite. The mineral from which
it is obtained is called tellurite, and consists, according to Klaproth,
of-
Tellurium
Gold
Iron
+
92.55
0.25
7.2
100.00
The metal is silvery white and brilliant; it has very much the ap-
pearance of antimony, being extremely brittle, and easily reduced to
powder. Its specific gravity is 62, and equivalent 642, and it forms
with oxygen tellurous acid (TeO) and telluric acid (TeO3).
Terbium has already been mentioned at p. 454, in connexion with
erbium, and is found in gadolinite.
Thorium, or thorinum, is a metallic curiosity, and found in thorite.
This mineral, according to Berzelius, consists of—
The oxide of thorium, thorina
Silica
Lime
Peroxide of iron.
Peroxide of manganese
Magnesia .
Oxide of uranium
Oxide of lead
•
Oxide of tin
Potash
Soda.
Alumina
Water
•
Undissolved mineral
Loss.
57.91
18.98
2.58
3:40
2.39
•
0.36
1.61
0.80
0.01
0.14
0.1
0.06
9.5
1.7
*46
100.00
Titanium, another rare metal discovered by Klaproth, and found, in
conjunction with iron, in certain iron ores, especially in rutile, which
contains about 60 per cent. of titanium. It forms three oxides, viz.—
Oxide of titanium
Sesquioxide
Titanic acid
•
•
TiO
Ti₂O,
Tio
3
and is described as a dark green powder, which burns vividly in the air
or oxygen, and forms titanic acid

Fig. 259. "Prevention is better than Cure."
CHAPTER XXXIV.
TUNGSTEN.
THIS metal is so called from a Swedish mineral called tungsten, or pon-
derous stone. The industrious Scheele discovered the tungstic acid in
1781, but D'Elhuyart first procured it in the metallic state by mixing
the acid substance obtained from wolfram (a mineral already alluded to
in connexion with tin ores) with powdered charcoal, and exposing it to
a very intense heat.
Berzelius calls tungsten "wolfranium." It is a greyish-white metal
OXLAND'S EXPERIMENTS WITH TUNGSTEN.
491
like steel, and possesses considerable brilliancy. It possesses a re-
markable hardness, and has lately been applied with success by Mr.
Oxland, of Plymouth, in the manufacture of the hardest steel, which,
it is said, will bore through and file ordinary steel, so that, if England
is to begin a course of experiments on the best armour for ships, Mr.
Oxland should be consulted on this most important question.
The specific gravity of tungsten is 17.6, and its equivalent 95. It
forms with oxygen gas two combinations :-
Binoxide of tungsten.
Tungstic acid
WO₂
WO,
2
Wolfram is obtained abundantly in Cornwall, and was formerly con-
sidered to be worthless; but since Oxland has discovered a mode of
separating the tin, and is now likely to employ the tungstic acid, we
may shortly expect to see the price of wolfram take a respectable posi-
tion in the metallic market. Wolfram is a tungstate of iron, and con-
sists of-
Tungstic acid.
Protoxide of iron
Protoxide of manganese
Silica
78-77
18.32
6.22
1.25
The above analysis of Berzelius is evidently incorrect, but still affords
a good notion of the quantities of the various ingredients.
This and other analyses show that wolfram is a double tungstate of
iron and manganese, (FeMn)O+WỌ¸. Tungstic acid is employed in
the preparation of tungstate of lead, which is said to be valuable as a
white pigment, and capable of being used for all the purposes to which
ordinary white-lcad is applied.
In order to prepare tungstic acid, wolfram is digested with aqua regia,
which dissolves out the iron and manganese, and leaves the tungstic
acid; the latter is then well washed, and heated with ammonia. This
alkali unites with the tungstic acid, and as the tungstate of ammonium
is soluble in water, the latter is easily separated from the remaining
silica or sand. By heating the tungstate of ammonium in air, tungstic
acid is procured, which has a straw-yellow colour, and is insoluble in
water and acids.
Tungstic acid is united with soda, and is used not only in calico
printing, but is found to be one of the best and cheapest anti-combus-
tible salts ever applied to textile fabrics, and, indeed, is now employed,
in conjunction with starch, in the royal laundry.

Fig. 360. Warrington's Microscope, an instrument of great value in analytical
investigations.
CHAPTER XXXV.
URANIUM, VANADIUM, YTTRIUM.
URANIUM deserves special notice, because, although a rare metal, its
oxide is employed most usefully for colouring glass of a peculiar yellow
colour, having certain curious optical characteristics, as shown by Pro-
fessor Stokes of Cambridge. It is likewise employed in porcelain
painting. The name of this metal is derived from that of the planet
Uranus," and it is procured in the state of oxide from "pitchblende,"
பமாம்
RARE METALS.
493
which is found in Cornwall, and also in Saxony and Bohemia. Thom-
son's process for procuring pure protoxide of uranium is thus described
by him: "Pitchblende is reduced to a fine powder, and digested with
nitric acid until everything soluble in that acid is removed. The solu-
tion is then rendered as neutral as possible by evaporation, and a cur-
rent of sulphuretted hydrogen gas passed through it as long as any
precipitate continues to fall. The liquid is then filtered and heated to
drive off all traces of sulphuretted hydrogen. It is now precipitated
by caustic ammonia, and the precipitate, after being well washed, is
digested, whilst still moist, in a pretty strong solution of carbonate of
ammonia. A fine lemon-coloured liquid is thus obtained, which, being
set on one side for a few days, deposits abundance of fine yellow
crystals, in four-sided right prisms with rectangular bases. These
crystals, being exposed to a red heat, give out water and carbonate of
ammonia with oxygen gas, and leave the protoxide of uranium in the
state of a black powder, having a good deal of lustre, but which, when
reduced to powder, presents a dark green colour." The yellow crystals

consist of
3 atoms carbonate of ammonia
1
1
4
percarbonate of uranium
water
>>
14.625
30.75
4.5
49.875
The specific gravity of uranium is 8.1, and its equivalent 60, and the
metal unites with oxygen in three proportions, viz. :·
The suboxide of uranium
The protoxide of uranium
The peroxide of uranium.
UO,
UO
•
U₂O3
Vanadium was discovered by Sefström, who called it after one of the
ancient female deities of Scandinavia. It is, of course, a rare metal,
and resembles chromium, molybdenum, and tungsten; the metal is like
chromium, because it imparts a green colour to blowpipe fluxes. It
also forms a red acid, vanadic (VO₂); but, whilst chromic acid retains
its colour on evaporation from its solution, vanadic changes by heat,
becomes colourless, and deposits vanadic acid in the form of a deep red
powder. The metal was first obtained from certain specimens of Swedish
iron, which were remarkable for their malleability, and was afterwards
procured in larger quantity from scoria of the furnace where the iron
had been melted. The equivalent of vanadium is 68.6, and it resembles
molybdenum in the blue colour of certain of its combinations. Vana-
dium has been obtained from certain lead ores; and there are three oxygen
compounds, viz., the protoxide (VO), the binoxide (VO.), and vanadic
acid (VO3).
Yttrium is another rare metal, first discovered in Jenny Lind's
country, at Ytterby, in Sweden, by Captain Arbenius, in 1788. Gadolin,
Vauquelin, and Klaproth all examined the new earth, which they called
yttria, being an oxide of the metal yttrium, and combined with gado-
linite, already described at p. 454, and named after Professor Gadolin.

Bustyne.del.
Palovaros.
Fig. 261. The Court of Lions.
CHAPTER XXXVI.
ZINC.
THIS metal was not known to the ancients, although they were ac-
quainted with the mineral cadmium or calamine; and without it they
could not have made brass, which alloy of zinc and copper is repeatedly
mentioned in the Scriptures; and its use in Solomon's temple, in the
construction of the sea of brass supported on the backs of twelve oxen,
no doubt suggested the beautiful Moorish fountain of lions of the
ancient. Alhambra, a copy of which adorns the lovely and unique
Alhambra Court of the Crystal Palace. Hesiod states that "in remote
ages the earth was tilled with brass implements of agriculture, because
iron had not been discovered."
Zinc appears to have been first called by that name in the writings of
the madly-zealous Paracelsus, about the year 1540. It is supposed that
PETTUS'S DEFINITION OF BRASS.
495
the term is derived from the Teutonic "zinken," signifying nails, be-
cause the metal, when poured in the liquid state into cold water (Fig. 265),
assumes the form of a number of jagged and pointed fragments, not
very much like nails, but perhaps sufficiently so for the fervid imagination
of the bombastic Paracelsus, who also termed calamine the spurious son
of copper. This divided condition of the metal is familiarly known to
every tyro of the art as granulated zinc." Lewery termed zinc a
kind of bismuth. Glauber imagined it to be an immature "solar
sulphur." Homberg said it was a mixture of tin and iron. Kunckel
(of phosphorus celebrity) declared it to be coagulated mercury.
Schluter imagined it to be tin made brittle with sulphur.
•
Pettus, in 1686, says "It is a great error that most writers run into,
by promiscuously giving the title Es for both Brass and Copper, as if
they were the same metals; whereas Es or Brass is not a proper Metal,
but compounded of a Metal, viz.: Cupreum or Copper, and Lapis
Calaminaris' or Cadmiæ, which is a Mineral, and from the mixture of
these two Brass is made. Now, whereas Pliny (cap. 33) speaks of
about eighteen several Mines of Brass, we must not understand it as a
specifick Metal, though the word Es is vulgarly applied to both; but
those Mines were either Copper Mines capable of being made Brass, or
so many several sorts of Lapis Cadmiæ or Calamine, from the compo-
sition of all which with Copper, Brass was made, more or less, both in
Quantity and Quality. And this art of composing it is said by him to
be first invented by Cadmus, a Grecian contemporary with Joshua, in
whose time the word Brass is first mentioned in the Sacred Story,
Exod. xxv. 3. And it is observable that though, in the composition of
Brass there is more of the Stone than of the Copper, and that Copper is
a Metal, and that other a Stone, yet it takes a new name of Brass, and
not its own, or of the Metal, Copper; and being thus made Brass, it is
an Imitation of Gold, both in Colour and in many Virtues, and in such
esteem that the Roman Treasurers were called ' Tribuni Ærarii,' rather
than Aurarii. And Camerarius says that the Egyptians (long before the
Romans) had so great Veneration of Brass, that they made Images of
it, and laid them in the graves of their Kings, to preserve their Bodies
from putrefaction; and to men of lesser quality they nailed their dead
bodies with many Brass nails. Also Virgil, Horace, and Homer are
all full of their Encomiums on Brass, and therefore it may well have the
honour of a seventh metal, though compounded of a mineral."
The metal zinc is first mentioned, about the thirteenth century, in
the writings of Albertus Magnus, under the name of the marcasite of
gold; and it is evident, from his account of it, that he was aware that
a volatile metal existed in the alloy. The use of calamine in the com-
position of brass was known to Aristotle, who makes a distinction
between the compound resulting from the mixture of copper and
calamine and that resulting from the mixture of copper and tin.
The ancients were acquainted with the fact that when cadmia was
burnt it changed into a white, flocculent, and spongy ash, that
volatilized, and which they employed in medicine. There are strong
496
ZINC.
1
reasons for believing that it was known at a very early period in China.
The Chinese were acquainted with the method of rendering it malleable,
and they struck pieces of money of it, having the Tartar characters on
one side and Chinese characters on the other. Kasimir, the Pliny of
the Arabians, at least states these circumstances as facts. The
Arabians called it Rouh-tutia, and the Persians Kar-tsini (Chinese iron).
According to Kasimir, "mirrors were made of it, which were considered
as useful in curing sore eyes." No ancient coins or implements made
of zinc have been discovered in Europe; and it was not till the beginning
of the eighteenth century that any processes were described for its
production. Dr. Isaac Lawson is said to have been the discoverer of
the process of distilling zinc from the ores, of which two are chiefly
employed for that purpose, viz.: the carbonate of zinc or calamine, and
the sulphide called "blende," or "blackjack." There are other im-
portant ores, especially the red zinc ore, or red oxide of zinc; and in
the Great Exhibition of 1851 an enormous mass of the latter ore was
deposited, weighing 16,400 pounds. The following are the names and
constituents of the zinc ores :-
Name.
The red zinc ore, or red oxide
of zinc
The sulphide of zinc; yellow,
brown, and black, blende, or
blackjack
The carbonate of zinc, calamine,
zinnespath, lapis calaminaris
Silicate of zinc, or electric cala-
mine
•
Constituents.
Zinc, oxygen, with some oxide of iron
and red oxide of manganese, which
are supposed to be the cause of the
red colour of the mineral.
(Contains zinc, sulphur, and sometimes
a little iron, fluorine, silica, and water,
arsenic, cadmium, lead, and copper.
Oxide of zinc and carbonic acid and
water.
Oxide of zinc, silica, and water.
The ores of zinc are discovered in the carboniferous or mountain lime-
stone, and in the magnesian limestone, or alpine limestone, and are asso-
ciated in nature most frequently with galena or sulphuret of lead,
copper pyrites, copper green, and iron pyrites; and the mining opera-
tions already explained in connexion with the latter mineral will also
serve to indicate the manner in which these zinc ores are procured.
Blackjack, or sulphide of zinc, is obtained in abundance in Cornwall,
Cumberland, and Derbyshire, and, in the absence of foreign zinc, would
doubtless be extensively reduced; but at the present time the celebrated
foreign company at the Vieille Montagne, near Liége, with others,
compete so successfully with British zinc, that it hardly pays to reduce
the ores. At Sheffield, Bristol, and Birmingham especially, the toy-
shop of the world, where so many brass articles are made, calamine is
reduced to the metallic state. The process is comparatively simple,
and consists in first carefully hand-picking the ore to remove the galena,
and then calcining it in a reverberatory furnace, or rather oven.
roasted ore, deprived of carbonic acid, water, and sulphur, as the case
The
REDUCTION OF ZINC ORES.
may be, is then mixed with char-
coal alone if prepared from cala-
mine; but if from blende, a certain
quantity of roasted calamine is
also added, and the whole placed
in earthen pots, or crucibles, very
much like the pots used at glass
works, but provided with a luted
cover and also with an opening at
the bottom, to which an iron pipe
is fitted. After the heat has been
applied sufficiently long, the vola-
tile metals, such as arsenic and
cadmium, make their way in va-
pour, per descensum, to the end of
the iron tube, where they afford a
flame, which the workmen distin-
guish by the name of the brown
blaze; this is succeeded by a blue
flame, called the blue blaze, which
indicates the distillation of the
zinc; and then the metal is con-
densed in the iron tube, and falls
in drops and in a powdery state
into a vessel placed to receive it;
as may be easily imagined, the
iron pipe sometimes becomes
stopped, and is occasionally
cleaned by a red-hot iron rod.
A
E
D
C
B
497

Fig. 262. A B. Large earthen crucible or pot
containing a mixture of roasted zinc ore and
coal or charcoal. c. The cover closely luted
vapour condenses and falls into the vessel E,
down. D. The iron pipe in which the zinc
containing enough water to cover the end of
the pipe. The pipe is removed after each
charge has been exhausted, in order to take out
the caput mortuum or matter left in the crucible
after distillation. The arrows show the direc
of the metallic vapour, and the iron pipe is
usually plugged with wood, w, which is soon
reduced to charcoal, and whilst preventing the
ore from falling out, does not stop the zinc
vapour.
Although it is not the first example of the distillation of a metal we
have had to notice, still the process of reduction by charcoal and distil-
lation per descensum (or in the reverse position of that usually taken by
the still head in the distillation of alcohol) is very interesting, and
affords another example of the intimate relations existing between solids,
liquids, and gases, and it also assists the mind in surmounting the diffi-
cult process of reasoning required by unscientific thinkers when they
endeavour to connect the permanent gaseous element hydrogen with the
solid metals, because the ideas generally associated with a gas and a metal
are so very far apart from each other; but when the chemical facts
are examined in detail, these apparent differences vanish by gradually
merging one into the other.
It is not, however, difficult to remember that the zinc chimney-pots
which help to convey away the gases from our fireplaces have themselves
once been in the state of vapour whilst being released from their
mineralized state by the deoxidizing power of heated carbon. The
crude distilled zinc is finally melted in large iron pots, and, after being
well skimmed, is cast into ingots. At the Vieille Montaigne works,
larger retorts, furnaces, and arrangements are employed for the distil-
K K
498
ZINC.
lation of the zinc, which, it might be imagined, could be readily
imitated and worked at a profit in England.
Zinc is a brilliant white metal having a slight tinge of blue, and a
specific gravity that varies from 6·861 to 7·1. The discovery of the
increase of its malleability at a temperature of about 212° Fah. has
greatly enhanced its value, and if the metal did not become soft and
malleable at that temperature, many articles now manufactured could
not be made, as it would break in the attempt to form it into shapes,
when it has to be hammered and bent at very sharp angles. Amateurs
who make voltaic batteries are sadly teazed with the hardness of zinc
until they learn that it can be easily bent, after being warmed to the
proper temperature, which is generally discovered by wetting the finger
and tapping it on the zinc: if the water evaporates at once with the
usual fizzing noise, the operation of bending may be commenced without
fear of breaking the zinc. There is, however, a limit to the increase of
malleability on the application of heat, and at 400° Fah., zinc becomes
so brittle that it can be easily powdered in a mortar; at 680° Fah. it
melts, and at a still higher temperature, volatilizes, and may be easily
distilled, provided the access of air is prevented.
Zinc, like many other metals, if allowed to cool slowly and in suffi-
cient quantity, crystallizes in prisms with six-sided bases, reminding one
of the basaltic columns of the
It's
Fig. 263. Zinc Chimney-pots.

Giants' Causeway.
The use of zinc to alloy
with copper and form br
has been already alluded to
there are also other important
alloys, such as pinchbeck,
which consists of five or six
parts of copper and one of
zinc; tombac, prince's metal,
and other arbitrary mixtures
of the two metals, which are
further described in the chap-
ter on copper.
The tenacity of zinc is very
moderate, but probably in-
creases with a temperature of
about 216° Fah. It is em-
ployed for covering the roofs
and lining the gutters of
houses instead of lead, which
is, of course, considered a
very false economy by builders,
unless the houses are built to
be sold; because during the
winter the zinc becomes
harsh and somewhat brittle,
EXPERIMENTS WITH ZINC.
499
and should the wind find its way under the zinc, the house roof is soon
stripped of its covering, or so bent and broken in parts, that the whole
must be renewed. Baths, window sashes, trade signs, frames of aqua
vivaria, and all kinds of ornamental work are constructed of this
metal, of which, perhaps, the least decorative are the chimney-pots, so
expressively delineated by Punch in his funny sketches.
EXPERIMENTS WITH ZINC.
First Series.
The assay of an ore of zinc by the dry method presents many difficulties
in the way of a correct estimation of the metal, in consequence of the
volatility of zinc; it is, therefore, usual to perform the assay by the wet
process: thus, if calamine is the ore under examination, it may be
roughly assayed by the following process. A weighed quantity is first
heated in a short hard German green glass tube, to which a weighed
tube filled with chloride of calcium or pumice-stone soaked in oil of
vitriol is attached, for the purpose of determining the per-centage of
water by the increase of weight in the latter tube.
Another weighed quantity is then strongly heated in a porcelain cru-
cible, and the loss represents the carbonic acid and water contained in
the mineral, and by deducting the weight of water obtained by the tube
experiment, the per-centage of two of the constituents-viz., water and
carbonic acid-are discovered. The roasted ore is now dissolved in
nitro-hydrochloric acid, evaporated to dryness, and the soluble salts
washed out, whilst the insoluble portion may be collected, washed,
dried and ignited, and they represent the silica.
The solution containing the soluble salts is precipitated by ammonia
in excess, and, being filtered, is evaporated to dryness with an excess of
carbonate of soda, again dissolved in water, the carbonate of zinc col-
lected on a filter, washed, dried, ignited, and estimated as oxide of zinc.
Various refinements on the above must be used if an exact analysis is
required.
Second Series.
The equivalent of zinc is 32-6, and it combines with oxygen in three
proportions, forming the
Suboxide of zinc
Protoxide of zinc
Peroxide of zinc
Zn,O
ZnO
ZnO₂
The existence of the suboxide has rather been inferred from analogy
and it is supposed to be formed when a bright metallic surface of zinc is
exposed for some time to the action of air and moisture.
The oxide of zinc (ZnO) appears to have been known to the ancients,
who called it pompholyx. It is easily prepared by setting fire to a
bundle of zinc turnings arranged in an ornamental iron-wire basket (used
for suspending flower-pots), and having a little tow saturated with spirits
!
500
ZINC.
A
B
C
"
of wine at the bottom
for the purpose of kindling
the metal. As the metal
burns it produces a large
quantity of very flocculent
oxide of zinc, which floats
about the air of the room,
and was called by the an-
cients and the alchemists
the "philosopher's wool"
flowers of zinc.
Diosco-
rides, who lived in the
second century of the
Christian era, was the first
who compared it to wool.
The oxide of zinc formed
in this manner is anhy-
drous; and it may also be
prepared by melting some
zinc in a red-hot crucible,
and then throwing in a
little nitre, which, afford-
ing oxygen, produces (when
stirredinto the melted zinc)
a most brilliant deflagra-
tion of the metal. Some

Fig. 284. A B. Iron-wire basket containing the zinc Zinc filings mixed with pow-
turnings, and having a very little tow at the bottom dered chlorate of potash
saturated with spirits of wine. c. The lighted torch will also easily take fire on
for igniting the tow at bottom of the basket.
falling particles indicate the oxide of zinc.
the application of a lighted
taper. When steam is passed
The
over zinc at a dull red heat, it is rapidly decomposed into its elements,
hydrogen escapes in large quantity, whilst the oxygen unites with the
metal and forms the oxide of zinc. Such is the affinity of zinc for
oxygen, that the decomposition of steam will commence even when the
zinc is only heated to 212° Fah., provided it is in a sufficiently divided
state. Zinc dissolves in fused potash with astonishing rapidity, being
oxidized at the expense of the alkali, and apparently combining,
like an acid, with the excess of potash. Pure oxide of zinc, when
heated, becomes yellow, but changes to white after being cooled; it is
extensively used as a pigment under the name of zinc white, which has
certain advantages, viz., that it does not produce those distressing
effects of colic on the system which are provoked by the use of lead
paint, and does not turn black by the sulphuretted hydrogen gas so
frequently prevalent in large towns where coal gas is made.
When diluted sulphuric acid is poured on zinc, the water is de-
composed, and the hydrogen escapes, as in the process of making that
gas so fully described in the "Playbook of Science," p. 107. The
EXPERIMENTS WITH ZINC.
501
oxide of zinc unites with the sulphuric acid, and forms the well
known salt called sulphate of zinc or white vitriol (ZnO,SO,), which is
prepared in the pure state by dissolving some ordinary zinc in dilute
sulphuric acid, and, after placing it in a large wide-mouthed bottle, some
chlorine may be poured in, and the whole well shaken, taking care to
prevent the stopper being fixed in through the vacuum formed, by
introducing a very fine thread, so that the stopper does not quite fit the
neck of the bottle, and permits the entry of the air. The object of the
chlorine is to convert any iron present to the state of peroxide, which
is precipitated when the solution is heated with a little excess of pure
carbonate of zinc. Subsequent filtration and careful evaporation will
yield crystals of pure sulphate of zinc. Native sulphate of zinc occurs
at Holywell, in Flintshire. Dr. Thomson denies the formation of the
binoxide of zinc (ZnO) by Thenard's process, and considers it to be
only a mixture of deutoxide of hydrogen and oxide of zinc. A very
distinguishing test for the oxide of zinc is a drop of a solution of nitrate
of cobalt, which, being dried and ignited with the oxide, becomes of a
green colour.
Third Series.
Chloride, iodine, bromine, and fluorine all unite with zinc; and of
these the most important is the chloride (ZnCl), which is prepared by
dissolving zinc in pure hydrochloric acid, heating the liquid with excess
of chlorine and carbonate of zinc, and, after filtration, finally evaporating
and fusing in a thin porcelain dish. Chloride of zinc forms beautiful
white lumps, that quickly deliquesce and dissolve very readily in water,
forming Sir W. Burnett's disinfecting fluid, which is sometimes employed
to delay the putrefaction of the subjects used for dissection. The chief
value of this disinfecting fluid is due to its power of absorbing sulphu-
retted hydrogen; but it has neither the deoxidizing power of sulphurous
acid, or the oxidizing power of chlorine or manganic acid. There are
both oxychlorides and oxysulphides of zinc. And the chloride of zinc
may also be prepared by dropping zinc filings into chlorine gas. So-
lutions of salt must not be kept in vessels lined with zinc; and the
author remembers a case where some brine used in pickling beef, and
kept with the latter in a zinc cistern or vat, contained a considerable
portion of chloride of zinc, which is a poisonous salt. When obtained
by distilling a mixture of corrosive sublimate and zinc filings, it was
distinguished by the alchemists as the "butter of zinc."
Fourth Series.
Zinc is detected by the following tests:
If an
Sulphuretted hydrogen precipitates the white sulphide of zinc (ZnS),
in part from perfectly neutral solutions of zinc, but affords no precipitate
in acid solutions, unless they are weak acids, such as acetic acid.
excess of acetate of soda is added to a neutral solution of zinc, the
whole of the metal may then be precipitated by sulphuretted hydrogen as
the sulphide of zinc.
502
ZINC.
Sulphide of ammonium precipitates the sulphide of zinc from neutral
and alkaline solutions insoluble in an excess of the reagent, or caustic
potash, or solution of ammonium, but soluble in acids. This is the
most characteristic test for zinc; and any strong, colourless, alkaline
solution, producing a white precipitate with a soluble sulphide, and
extremely difficult to filter, may be pronounced to contain zinc with
almost unerring certainty.
Solutions of potash and ammonium precipitate the hydrated oxide of
zinc, which is soluble in an excess of the precipitate.
A solution of carbonate of ammonia throws down a hydrated car-
bonate of zinc, soluble in an excess.
Carbonate of soda, in the absence of salts of ammonia, precipitates
the carbonate of zinc, insoluble in an excess. A drop of a solution of
nitrate of cobalt placed on oxide of zinc, and ignited, affords an
emerald-green colour.

Fig. 265. Process of granulating Zinc by pouring it from a height into a pail of
cold water.
CHAPTER XXXVII.
ZIRCONIUM.
AMONG the precious stones exhibited by Hunt and Roskell, of Bond-
street, at the first palace in Hyde-park, were some magnificent speci-
mens of the jewel called zircon, or jargon, or jargoon, of which one
deserves special comment, being a superlatively fine jargon, of an oc-
tagonal form, cut with step facets, of a very fine deep orange colour of
the purest tint, having the charming hue, prismatic play, and brilliancy
of the diamond. At the time it was considered that it would be a
difficult task to match this beautiful gem, on account of its extraor-
dinary fine and unique colour. The hardness of this gem is, however,
inferior to that of the sapphire, one of the lovely forms assumed by
alumina; but it is greater than that of the spinel ruby, its specific
gravity being 4-416 to 47. Klaproth analysed it in 1789, and disco-
vered therein a new earth, which he termed zirconium. Berzelius, in
1824, was the first to obtain the metal from the oxide of zirconium, or
zirconia, from the potash fluate of zirconia; and the impure metal is
stated to have a close resemblance to charcoal dust, and does not
assume any brilliancy even after being rubbed with a burnisher. When
purified, zirconium is like plumbago. It is composed of brilliant scales,
and is stated to be an exception to one of the special properties of
the metals in being a non-conductor of electricity. Zirconia (Zr₂O¸) is
the only compound of this metal with oxygen known at present; and
its metallic qualities, as above stated, ought to be received with some
reservation, considering that it has not yet, like aluminium, been cast
into bars or lumps, and therefore its mechanical characteristics can
hardly be described.
2 3

CHAPTER XXXVIII.
GENERAL REMARKS.
In the preceding chapters the metals have been described alphabetically,
with the exception of those which were known to the ancients. This
arrangement was adopted to facilitate reference; but one of the best
classifications is probably that of Gmelin, who arranges the metals as
follows:
A. Alkali metals
B. Earth metals.
I. Light Metals.
J Potassium, sodium, lithium, barium, stron-
tium, calcium.
Magnesium, cerium, lanthanium, didymnium,
yttrium, erbium, terbium, glucinum, alu-
minium, thorium, silicium, zirconium.
II. Heavy Metals.
C. Base metals not redu- )
cible by heat alone,
brittle, and also diffi-
cultly fusible
D. Easily fusible or vola-
tile
E. Malleable.
Titanium, tantalum, niobium, pelopium,
tungsten, molybdenum, vanadium, chro-
mium, uranium, magnesium.
Arsenic, antimony, tellurium, and bis-
muth.
Zinc, cadmium, tin, lead, iron, cobalt,
nickel, and copper.
Mercury, silver, gold, platinum, palladium,
rhodium, iridium, ruthenium, osmium.
Thus
F. Noble metals, reducible
by heat alone.
Even this arrangement might be criticized in many ways.
aluminium is not placed amongst the malleable metals; but still the
metals are arranged according to their predominating qualities, and the
difficult question of attempting to classify the metals is certainly dis-
posed of in a satisfactory manner by the author and translator of that
colossus of chemical works, Gmelin's "Handbook of Chemistry.'
>>
The author has felt great difficulty in selecting from the immense
stores of our information on the metals the precise facts that would
please and instruct the young, and has therefore endeavoured to
carry the youthful reader through the somewhat tedious and lengthy
numbers of the metals by giving pictorial illustrations as helps to
artificial memory; so that, by merely looking through the pictures of
this book, he may gain at once the first and most simple rudiments of a
knowledge of the metals.
THE END.

*
UNIVERSITY OF MICHIGAN
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