Arthur Train - "The Confessions of Artemas Quibble"

Edward Sell - "The Faith of Islam"

Various - "Notes and Queries, Number 185, May 14, 1853"

Jules Verne - "20000 Lieues sous les mers Parts 1&2"

Annual Bibliography of Commonwealth Literature 2007
This paper argues that discourses of love in Ghanaian market literature for youth offer a view into complex negotiations of agency and empowerment. Drawing on Deborah Durham's notion of youth as "social `shifters'" and Francis Nyamnjoh's conception of the "interconnectedness" of agency, I take Ghanaian market literature as one specific case of how African literature for youth foregrounds questions of continuity and change as African societies enter into increasingly complex global relations. In this literature for youth, received notions of love, often constructed out of impressions from American pop and hip hop music, carry new notions of agency that compete with existing "domesticated" forms. Authors like Ike Tandoh and Evelyn Tay employ discourses of love to offer youth alternative avenues for empowerment in a context of socio-economic disenfranchizement. In a creative process of "straddling", this writing both reveals and reproduces the contradictions that obtain in youth configurations of agency.

The Botanic Garden

E >> Erasmus Darwin >> The Botanic Garden




Not only iron but manganese, calamy, and even copper and lead appear in
some instances to have been of recent production. Iron and manganese are
detected in all vegetable productions, and it is probable other metallic
bodies might be found to exist in vegetable or animal matters, if we had
tests to detect them in very minute quantities. Manganese and calamy are
found in beds like iron near the surface of the earth, and in a
calciform state, which countenances their modern production. The recent
production of calamy, one of the ores of zinc, appears from its
frequently incrusting calcareous spar in its descent from the surface of
the earth into the uppermost fissures of the limestone mountains of
Derbyshire. That the calamy has been carried by its solution or
diffusion in water into these cavities, and not by its ascent from below
in form of steam, is evinced from its not only forming a crust over the
dogtooth spar, but by its afterwards dissolving or destroying the sparry
crystal. I have specimens of calamy in the form of dogtooth spar, two
inches high, which are hollow, and stand half an inch above the
diminished sparry crystal on which they were formed, like a sheath a
great deal too big for it; this seems to shew, that this process was
carried on in water, otherwise after the calamy had incrusted its spar,
and dissolved its surface, so as to form a hollow cavern over it, it
could not act further upon it except by the interposition of some
medium. As these spars and calamy are formed in the fissures of
mountains they must both have been formed after the elevation of those
mountains.

In respect to the recent production of copper, it was before observed in
note on Canto II. l. 394, that the summit of the grit-stone mountain at
Hawkstone in Shropshire, is tinged with copper, which from the
appearance of the blue stains seems to have descended to the parts of
the rock beneath. I have a calciform ore of copper consisting of the
hollow crusts of cubic cells, which has evidently been formed on
crystals of fluor, which it has eroded in the same manner as the calamy
erodes the calcareous crystals, from whence may be deduced in the same
manner, the aqueous solution or diffusion, as well as the recent
production of this calciform ore of copper.

Lead in small quantities is sometimes found in the fissures of coal-
beds, which fissures are previously covered with spar; and sometimes in
nodules of iron-ore. Of the former I have a specimen from near Caulk in
Derbyshire, and of the latter from Colebrook Dale in Shropshire. Though
all these facts shew that some metallic bodies are formed from vegetable
or animal recrements, as iron, and perhaps manganese and calamy, all
which are found near the surface of the earth; yet as the other metals
are found only in fissures of rocks, which penetrate to unknown depths,
they may be wholly or in part produced by ascending steams from
subterraneous fires, as mentioned in note on Canto II. l. 398.



SEPTARIA OF IRON-STONE.

Over some lime works at Walsall in Staffordshire, I observed some years
ago a stratum of iron earth about six inches thick, full of very large
cavities; these cavities were evidently produced when the material
passed from a semifluid state into a solid one; as the frit of the
potters, or a mixture of clay and water is liable to crack in drying;
which is owing to the further contraction of the internal part, after
the crust is become hard. These hollows are liable to receive extraneous
matter, as I believe gypsum, and sometimes spar, and even lead; a
curious specimen of the last was presented to me by Mr. Darby of
Colebrook Dale, which contains in its cavity some ounces of lead-ore.
But there are other septaria of iron-stone which seem to have had a very
different origin, their cavities having been formed in cooling or
congealing from an ignited state, as is ingeniously deduced by Dr.
Hutton from their internal structure. Edinb. Transact. Vol. I. p. 246.
The volcanic origin of these curious septaria appears to me to be
further evinced from their form and the places where they are found.
They consist of oblate spheroids and are found in many parts of the
earth totally detached from the beds in which they lie, as at East
Lothian in Scotland. Two of these, which now lie before me, were found
with many others immersed in argillaceous shale or shiver, surrounded by
broken limestone mountains at Bradbourn near Ashbourn in Derbyshire, and
were presented to me by Mr. Buxton, a gentleman of that town. One of
these is about fifteen inches in its equatorial diameter, and about six
inches in its polar one, and contains beautiful star-like septaria
incrusted and in part filled with calcareous spar. The other is about
eight inches in its equatorial diameter, and about four inches in its
polar diameter, and is quite solid, but shews on its internal surface
marks of different colours, as if a beginning separation had taken
place. Now as these septaria contain fifty per cent, of iron, according
to Dr. Hutton, they would soften or melt into a semifluid globule by
subterraneous fire by less heat than the limestone in their vicinity;
and if they were ejected through a hole or fissure would gain a circular
motion along with their progressive one by their greater friction or
adhesion to one side of the hole. This whirling motion would produce the
oblate spheroidical form which they possess, and which as far as I know
can not in any other way be accounted for. They would then harden in the
air as they rose into the colder parts of the atmosphere; and as they
descended into so soft a material as shale or shiver, their forms would
not be injured in their fall; and their presence in materials so
different from themselves becomes accounted for.

About the tropics of the large septarium above mentioned, are circular
eminent lines, such as might have been left if it had been coarsely
turned in a lathe. These lines seem to consist of a fluid matter, which
seems to have exsuded in circular zones, as their edges appear blunted
or retracted; and the septarium seems to have split easier in such
sections parallel to its equator. Now as the crust would first begin to
cool and harden after its ejection in a semifluid state, and the
equatorial diameter would become gradually enlarged as it rose in the
air; the internal parts being softer would slide beneath the polar
crust, which might crack and permit part of the semifluid to exsude, and
it is probable the adhesion would thus become less in sections parallel
to the equator. Which further confirms this idea of the production of
these curious septaria. A new-cast cannon ball red-hot with its crust
only solid, if it were shot into the air would probably burst in its
passage; as it would consist of a more fluid material than these
septaria; and thus by discharging a shower of liquid iron would produce
more dreadful combustion, if used in war, than could be effected by a
ball, which had been cooled and was heated again: since in the latter
case the ball could not have its internal parts made hotter than the
crust of it, without first loosing its form.




NOTE XIX.--FLINT.


_Transmute to glittering flints her chalky lands,
Or sink on Ocean's bed in countless sands._

CANTO II. l. 217.


1. SILICEOUS ROCKS.

The great masses of siliceous sand which lie in rocks upon the beds of
limestone, or which are stratified with clay, coal, and iron-ore, are
evidently produced in the decomposition of vegetable or animal matters,
as explained in the note on morasses. Hence the impressions of vegetable
roots and even whole trees are often found in sand-stone, as well as in
coals and iron-ore. In these sand-rocks both the siliceous acid and the
calcareous base seem to be produced from the materials of the morass;
for though the presence of a siliceous acid and of a calcareous base
have not yet been separately exhibited from flints, yet from the analogy
of flint to fluor, and gypsum, and marble, and from the conversion of
the latter into flint, there can be little doubt of their existence.

These siliceous sand-rocks are either held together by a siliceous
cement, or have a greater or less portion of clay in them, which in some
acts as a cement to the siliceous crystals, but in others is in such
great abundance that in burning them they become an imperfect porcelain
and are then used to repair the roads, as at Chesterfield in Derbyshire;
these are called argillaceous grit by Mr. Kirwan. In other places a
calcareous matter cements the crystals together; and in other places the
siliceous crystals lie in loose strata under the marl in the form of
white sand; as at Normington about a mile from Derby.

The lowest beds of siliceous sand-stone produced from morasses seem to
obtain their acid from the morass, and their calcareous base from the
limestone on which it rests; These beds possess a siliceous cement, and
from their greater purity and hardness are used for course grinding-
stones and scyth stones, and are situated on the edges of limestone
countries, having lost the other strata of coals, or clay, or iron,
which were originally produced above them. Such are the sand-rocks
incumbent on limestone near Matlock in Derbyshire. As these siliceous
sand-rocks contain no marine productions scattered amongst them, they
appear to have been elevated, torn to pieces, and many fragments of them
scattered over the adjacent country by explosions, from fires within the
morass from which they have been formed; and which dissipated every
thing inflammable above and beneath them, except some stains of iron,
with which they are in some places spotted. If these sand-rocks had been
accumulated beneath the sea, and elevated along with the beds of
limestone on which they rest, some vestiges of marine shells either in
their siliceous or calcareous state must have been discerned amongst
them.


2. SILICEOUS TREES.

In many of these sand-rocks are found the impressions of vegetable
roots, which seem to have been the most unchangeable parts of the plant,
as shells and shark's teeth are found in chalk-beds from their being the
most unchangeable parts of the animal. In other instances the wood
itself is penetrated, and whole trees converted into flint; specimens of
which I have by me, from near Coventry, and from a gravel-pit in
Shropshire near Child's Archal in the road to Drayton. Other polished
specimens of vegetable flints abound in the cabinets of the curious,
which evidently shew the concentric circles of woody fibres, and their
interstices filled with whiter siliceous matter, with the branching off
of the knots when cut horizontally, and the parallel lines of wood when
cut longitudinally, with uncommon beauty and variety. Of these I possess
some beautiful specimens, which were presented to me by the Earl of
Uxbridge.

The colours of these siliceous vegetables are generally brown, from the
iron, I suppose, or manganese, which induced them to crystallize or to
fuse more easily. Some of the cracks of the wood in drying are filled
with white flint or calcedony, and others of them remain hollow, lined
with innumerable small crystals tinged with iron, which I suppose had a
share in converting their calcareous matter into siliceous crystals,
because the crystals called Peak-diamonds are always found bedded in an
ochreous earth; and those called Bristol-stones are situated on
limestone coloured with iron. Mr. F. French presented me with a
congeries of siliceous crystals, which he gathered on the crater (as he
supposes) of an extinguished volcano at Cromach Water in Cumberland. The
crystals are about an inch high in the shape of dogtooth or calcareous
spar, covered with a dark ferruginous matter. The bed on which they rest
is about an inch in thickness, and is stained with iron on its
undersurface. This curious fossil shews the transmutation of calcareous
earth into siliceous, as much as the siliceous shells which abound in
the cabinets of the curious. There may sometime be discovered in this
age of science, a method of thus impregnating wood with liquid flint,
which would produce pillars for the support, and tiles for the covering
of houses, which would be uninflammable and endure as long as the earth
beneath them.

That some siliceous productions have been in a fluid state without much
heat at the time of their formation appears from the vegetable flints
above described not having quite lost their organized appearance; from
shells, and coralloids, and entrochi being converted into flint without
loosing their form; from the bason of calcedony round Giesar in Iceland;
and from the experiment of Mr. Bergman, who obtained thirteen regular
formed crystals by suffering the powder of quartz to remain in a vessel
with fluor acid for two years; these crystals were about the size of
small peas, and were not so hard as quartz. Opusc. de Terra Silicea, p.
33. Mr. Achard procured both calcareous and siliceous crystals, one from
calcareous earth, and the other from the earth of alum, both dissolved
in water impregnated with fixed air; the water filtrating very slowly
through a porous bottom of baked clay. See Journal de Physique, for
January, 1778.


3. AGATES, ONYXES, SCOTS-PEBBLES.

In small cavities of these sand-rocks, I am informed, the beautiful
siliceous nodules are found which are called Scot's-pebbles; and which
on being cut in different directions take the names of agates, onyxes,
sardonyxes, &c. according to the colours of the lines or strata which
they exhibit. Some of the nodules are hollow and filled with crystals,
others have a nucleus of less compact siliceous matter which is
generally white, surrounded with many concentric strata coloured with
iron, and other alternate strata of white agate or calcedony, sometimes
to the number of thirty.

I think these nodules bear evident marks of their having been in perfect
fusion by either heat alone, or by water and heat, under great pressure,
according to the ingenious theory of Dr. Hutton; but I do not imagine,
that they were injected into cavities from materials from without, but
that some vegetables or parts of vegetables containing more iron or
manganese than others, facilitated the compleat fusion, thus destroying
the vestiges of vegetable organization, which were conspicuous in the
siliceous trees above mentioned. Some of these nodules being hollow and
lined with crystals, and others containing a nucleus of white siliceous
matter of a looser texture, shew they were composed of the materials
then existing in the cavity; which consisting before of loose sand, must
take up less space when fused into a solid mass.

These siliceous nodules resemble the nodules of iron-stone mentioned in
note on Canto II. l. 183, in respect to their possessing a great number
of concentric spheres coloured generally with iron, but they differ in
this circumstance, that the concentric spheres generally obey the form
of the external crust, and in their not possessing a chalybeate nucleus.
The stalactites formed on the roofs of caverns are often coloured in
concentric strata, by their coats being spread over each other at
different times; and some of them, as the cupreous ones, possess great
beauty from this formation; but as these are necessarily more or less of
a cylindrical or conic form, the nodules or globular flints above
described cannot have been constructed in this manner. To what law of
nature then is to be referred the production of such numerous concentric
spheres? I suspect to the law of congelation.

When salt and water are exposed to severe frosty air, the salt is said
to be precipitated as the water freezes; that is, as the heat, in which
it was dissolved, is withdrawn; where the experiment is tried in a bowl
or bason, this may be true, as the surface freezes first, and the salt
is found at the bottom. But in a fluid exposed in a thin phial, I found
by experiment, that the extraneous matter previously dissolved by the
heat in the mixture was not simply set at liberty to subside, but was
detruded or pushed backward as the ice was produced. The experiment was
this: about two ounces of a solution of blue vitriol were accidentally
frozen in a thin phial, the glass was cracked and fallen to pieces, the
ice was dissolved, and I found a pillar of blue vitriol standing erect
on the bottom of the broken bottle. Nor is this power of congelation
more extraordinary, than that by its powerful and sudden expansion it
should burst iron shells and coehorns, or throw out the plugs with which
the water was secured in them above one hundred and thirty yards,
according to the experiments at Quebec by Major Williams. Edinb.
Transact. Vol. II. p. 23.

In some siliceous nodules which now lie before me, the external crust
for about the tenth of an inch consists of white agate, in others it is
much thinner, and in some much thicker; corresponding with this crust
there are from twenty to thirty superincumbent strata, of alternately
darker and lighter colour; whence it appears, that the external crust as
it cooled or froze, propelled from it the iron or manganese which was
dissolved in it; this receded till it had formed an arch or vault strong
enough to resist its further protrusion; then the next inner sphere or
stratum as it cooled or froze, propelled forwards its colouring matter
in the same manner, till another arch or sphere produced sufficient
resistance to this frigoriscent expulsion. Some of them have detruded
their colouring matter quite to the centre, the rings continuing to
become darker as they are nearer it; in others the chalybeate arch seems
to have stopped half an inch from the centre, and become thicker by
having attracted to itself the irony matter from the white nucleus,
owing probably to its cooling less precipitately in the central parts
than at the surface of the pebble.

A similar detrusion of a marly matter in circular arches or vaults
obtains in the salt mines in Cheshire; from whence Dr. Hutton very
ingeniously concludes, that the salt must have been liquified by heat;
which would seem to be much confirmed by the above theory. Edinb.
Transact. Vol. I. p. 244.

I cannot conclude this account of Scots-pebbles without observing that
some of them on being sawed longitudinally asunder, seem still to
possess some vestiges of the cylindrical organization of vegetables;
others possess a nucleus of white agate much resembling some bulbous
roots with their concentric coats, or the knots in elm-roots or crab-
trees; some of these I suppose were formed in the manner above
explained, during the congelation of masses of melted flint and iron;
others may have been formed from a vegetable nucleus, and retain some
vestiges of the organization of the plant.


4. SAND OF THE SEA.

The great abundance of siliceous sand at the bottom of the ocean may in
part be washed down from the siliceous rocks above described, but in
general I suppose it derives its acid only from the vegetable and animal
matter of morasses, which is carried down by floods or by the
atmosphere, and becomes united in the sea with its calcareous base from
shells and coralloids, and thus assumes its crystalline form at the
bottom of the ocean, and is there intermixed with gravel or other
matters washed from the mountains in its vicinity.


5. CHERT, OR PETROSILEX.

The rocks of marble are often alternately intermixed with strata of
chert, or coarse flint, and this in beds from one to three feet thick,
as at Ham and Matlock, or of less than the tenth of an inch in
thickness, as a mile or two from Bakewell in the road to Buxton. It is
difficult to conceive in what manner ten or twenty strata of either
limestone or flint, of different shades of white and black, could be
laid quite regularly over each other from sediments or precipitations
from the sea; it appears to me much easier to comprehend, by supposing
with Dr. Hutton, that both the solid rocks of marble and the flint had
been fused by great heat, (or by heat and water,) under immense
pressure; by its cooling or congealing the colouring matter might be
detruded, and form parallel or curvilinean strata, as above explained.

The colouring matter both of limestone and flint was probably owing to
the flesh of peculiar animals, as well as the siliceous acid, which
converted some of the limestone into flint; or to some strata of shell-
fish having been overwhelmed when alive with new materials, while others
dying in their natural situations would lose their fleshy parts, either
by its putrid solution in the water or by its being eaten by other sea-
insects. I have some calcareous fossil shells which contain a black
coaly matter in them, which was evidently the body of the animal, and
others of the same kind filled with spar instead of it. The Labradore
stone has I suppose its colours from the nacre or mother-pearl shells,
from which it was probably produced. And there is a stratum of
calcareous matter about six or eight inches thick at Wingerworth in
Derbyshire over the iron-beds, which is replete with shells of fresh-
water muscles, and evidently obtains its dark colour from them, as
mentioned in note XVI. Many nodules of flint resemble in colour as well
as in form the shell of the echinus or sea-urchin; others resemble some
coralloids both in form and colour; and M. Arduini found in the Monte de
Pancrasio, red flints branching like corals, from whence they seem to
have obtained both their form and their colour. Ferber's Travels in
Italy, p. 42.


6. NODULES OF FLINT IN CHALK-BEDS.

As the nodules of flint found in chalk-beds possess no marks of having
been rounded by attrition or solution, I conclude that they have gained
their form as well as their dark colour from the flesh of the shell-fish
from which they had their origin; but which have been so compleatly
fused by heat, or heat and water, as to obliterate all vestiges of the
shell, in the same manner as the nodules of agate and onyx were produced
from parts of vegetables, but which had been so completely fused as to
obliterate all marks of their organization, or as many iron-nodules have
obtained their form and origin from peculiar vegetables.

Some nodules in chalk-beds consist of shells of echini filled up with
chalk, the animal having been dissolved away by putrescence in water, or
eaten by other sea-insects; other shells of echini, in which I suppose
the animal's body remained, are converted into flint but still retain
the form of the shell. Others, I suppose as above, being more completely
fused, have become flint coloured by the animal flesh, but without the
exact form either of the flesh or shell of the animal. Many of these are
hollow within and lined with crystals, like the Scot's-pebbles above
described; but as the colouring matter of animal bodies differs but
little from each other compared with those of vegetables, these flints
vary less in their colours than those above mentioned. At the same time
as they cooled in concentric spheres like the Scot's-pebbles, they often
possess faint rings of colours, and always break in conchoide forms
like them.

This idea of the production of nodules of flint in chalk-beds is
countenanced from the iron which generally appears as these flints
become decomposed by the air; which by uniting with the iron in their
composition reduces it from a vitrescent state to that of calx, and thus
renders it visible. And secondly, by there being no appearance in chalk-
beds of a string or pipe of siliceous matter connecting one nodule with
another, which must have happened if the siliceous matter, or its acid,
had been injected from without according to the idea of Dr. Hutton. And
thirdly, because many of them have very large cavities at their centres,
which should not have happened had they been formed by the injection of
a material from without.

When shells or chalk are thus converted from calcareous to siliceous
matter by the flesh of the animal, the new flint being heavier than the
shell or chalk occupies less space than the materials it was produced
from; this is the cause of frequent cavities within them, where the
whole mass has not been completely fused and pressed together. In
Derbyshire there are masses of coralloid and other shells which have
become siliceous, and are thus left with large vacuities sometimes
within and sometimes on the outside of the remaining form of the shell,
like the French millstones, and I suppose might serve the same purpose;
the gravel of the Derwent is full of specimens of this kind.

Since writing the above I have received a very ingenious account of
chalk-beds from Dr. MENISH of Chelmsford. He distinguishes chalk-beds
into three kinds; such as have been raised from the sea with little
disturbance of their strata, as the cliffs of Dover and Margate, which
he terms _intire_ chalk. Another state of chalk is where it has suffered
much derangement, as the banks of the Thames at Gravesend and Dartford.
And a third state where fragments of chalk have been rounded by water,
which he terms _alluvial_ chalk. In the first of these situations of
chalk he observes, that the flint lies in strata horizontally, generally
in distinct nodules, but that he has observed two instances of solid
plates or strata of flint, from an inch to two inches in thickness,
interposed between the chalk-beds; one of these is in a chalk-bank by
the road side at Berkhamstead, the other in a bank on the road from
Chatham leading to Canterbury. Dr. Menish has further observed, that
many of the echini are crushed in their form, and yet filled with flint,
which has taken the form of the crushed shell, and that though many
flint nodules are hollow, yet that in some echini the siliceum seems to
have enlarged, as it passed from a fluid to a solid state, as it swells
out in a protuberance at the mouth and anus of the shell, and that
though these shells are so filled with flint yet that in many places the
shell itself remains calcareous. These strata of nodules and plates of
flint seem to countenance their origin from the flesh of a stratum of
animals which perished by some natural violence, and were buried in
their shells.

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