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TAB. CCIII.
CUPRUM carbonatum.
Crystallized Blue Carbonate of Copper.
Class 3. Metals. Order 1. Homogeneous.
Gen, 10, Cuprum. Spec. 5. Carbonatum,
Div. 1. Crystallized.
Syn. Cuivre oxidé bleu. De Born, 2. 329.
Azure de Cuivre. De Lisle, 3. 541.
Kupfer lazur, Emmert. 2. 246.
Blue Calciform Copper Ore. Kirw. 2. 129.
Cuivre carbonaté bleu. Hauy, 3. 562.
Buve Carbonate of Copper has rarely been seen crystal-
_ lized, especially in the present forms, and has not, I be-
lieve, been before mentioned as a native of any part of
Great Britain. The present rare specimen is preserved in
the cabinet of G. Laing, Esq., and comes from Wanlock-
head mine. I have some beautiful specimens from Corn-
wall, undoubtedly of this kind, but could not be certain
of their formation until compared with these.
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TAB. CCIV.
CUPRUM carbonatum.
Crystallized Green Carbonate of Copper.
Div. 1. Crystallized.
Tis came from nearly the same spot as the last, and is
equally rare. The crystals are nearly the same, and only
differ in being thicker, and having truncations. We are
enabled to show whole crystals, as my kind correspon-
dent sent me some that were found loose. It is al-
ways an interesting discovery in the true science of Mine-
ralogy to find the crystals of any substance, that when
thoroughly acquainted with it, we may be less at a loss to
know it without analysis, so that it may often prevent the
destruction of a rare specimen. We, therefore, without
analysis, consider these crystals as the same with what we
have less perfectly crystallized from other places, as
Wales, &c.
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Mark 11807. Pubtisha by Ja‘ Sowerby, Londo .
TAB. CCV.
CALX phosphata. —
Phosphate of Lime, or Apatite.
Class 2. Earths. Order 1. Homogeneous.
Gen. 3, Calx. Spec. 3. Phosphata.
Div. 1. Crystallized.
Syn. Gemeiner apatit. Emmerl. 1. 502.
Chaux phosphorée, Apatite. De Born, 1. 363.
Calx, combined with Phosphoric Acid. Kirw.
1. 128. ,
Amethyste basaltine. De Lisle, 2. 254.
Chaux phosphatée. Mauy, 2. 234.
Aparire has not long been known as a native substance
of Great Britain, and [ believe it has only been found at
Stenna Gwyn, in Cornwall, from whence I have received
it by favour of Mr. Rashleigh. In many instances the
crystals are so small and so much imbedded in talcose rock
as scarcely to be discernible, and it is not uncommon for
the rock itself, or rather the gangue, to be thought Phos-
phate of Lime altogether. The present specimen was pro-
cured some years since, and is still a fine one, particularly
as it shows the primitive crystal, and the nature of its
fracture, which is very distinctly and neatly apparent. It
10
also shows some of the various tints, such as purplish,
blueish and greenish, natural to it, though rather palely *.
Apatite is infusible by the blowpipe. Powdered, and
thrown on red-hot coals, it emits a yellowish green phos-
phorescent light. It is soluble in muriatic acid, and the
solution becomes gelatinous. No decomposition of the
phosphoric acid from the Lime takes place. This plate
shows the integrant molecule, a regular triangular prism,
very distinct in the fractures of the specimen, and also the
primitive hexangular prism. It has been noticed as found
in Spain and Germany by most mineralogists:—In the
former it constitutes large mountains.
®% We have since received a fine specimen of an opaque white, and water
blue, from Dr. Turton, about a quarter of an inch in length.
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Mar.2.1807.2ubuisha by Jas Sowerby Londen .
11
TAB. CCVI.
C A LX phosphata.
Phosphate* of Lime.
Div. 1. Crystallized.
$$
Tuts specimen shows some of the varieties in the trunca-
tions and bevillings of the hexaédral prism, from the alter-
nately truncated edges—see the upper geometrical figure—
to the more complicated—see the lower figure.
The gangue is commonly talcose, with Oxide of Tin and
with Quartz, sometimes with Fluor, Felspar, and rarely
white Topaz, as in this specimen.
The prevalent quantity of Talc often gives it a waxy ap-
pearance, and this is peculiar to this rock, which, thus
differing from the general appearance of rocks, has been
supposed to be, and even sold for, Apatite itself.
Apatite has been confounded with Beryl by the Chemist
Trommsdorf, who thought it to contain a new earth, which
he named Augustite, but this is now understood to be an error.
* Phosphorus is sometimes united artificially with Lime, forming a powder,
which, if put into water, sinks to the bottom, but soon decomposes the water
by taking up part of its oxygen, and freeing part of the hydrogen: the
phosphorus becomes inflamed; and while this decomposition is taking place,
flames burst forth through the water till the phosphorus is consumed.
12
The upper geometrical figure shows the prism truncated on
the three alternate vertical edges. The left hand figure
below shows an hexaédral pyramid placed on the solid
angles of the prism. The right hand figure shows facets
that are on the horizontal edges and solid angles. The lower
figure shows both ends, forming the alternating pyramid,
giving four- and six- sided facets to the prism *.
* It is remarkable that the pyramids in our erystals alternate with the
faces of the prism, Hlatiy found them only opposite.
Vermeer Ae
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207
Nev.2206 . Publisha by Jaf Sowaby, London -
13
TAB. CCVII.
SILEX Quartzum.
Quartz Septarium.
Div. 2. Imitative.
Quartz is metamorphosed into so many different shapes,
that we never can be aware of the varieties; and the ap-
pearance of the present specimen would by no means indi-
cate such a substance. From its dull appearance it has ge-
nerally been taken for Lead, or some other metal, as it
looks as if easily flexible. The hardness and sharpness of
the delicately acute edges, however, soon betray it, and the
fractures, showing its crystallization, pretty readily deter-
mine it.
It seems quite natural to most Quartz to have been in
solution. In this instance, having evidently formed itself
in the cracks of the Clay, it is the more instructive ; for
whatever might have held the Quartz in solution, might,
at the same time, have decomposed the Clay, which, how-
ever, must have been dry enough to have cracked, and
formed sharp and neatly distinct fissures, so beautifully
shown by the Quartz. But if fire had dissolved the Quartz,
the Clay would have been baked: and that is not the case ;
as the latter, in its common state, remains in some of the
fissures. This specimen is the production of Cumberland,
and I have been favoured by the Rev. Mr. Harriman and
Mr. Oliver with a piece about a foot in length from which
the Clay had apparently been washed out, chiefly on one
14
side. The present specimen, however, is remarkable for
the incurved structure of the Sept.
Perhaps an attention to the nature of the subject will
give a theory for the cause, or lead us nearer to the cause
in question. Thus the general contrarieties of heat and
cold may be the cause. Clay cracks from contraction in
cold or frost, giving out much of its water into the fissures,
which latter, becoming impregnated with Quartz (which
may be crystallized from a saturated solution in any me-
dium), thus retains its position, and afterwards the water
may wash away the Clay under various circumstances.
I do not know whether it is pure water that forms in the
cracks of frosty Clay; perhaps it may be impregnated with
Quartz, whose natural temperature will not allow above
a certain quantity to remain with the Clay*. This might
be really of consequence enough to be inquired into by
those who have the opportunity.
* Common Clay is mostly a mixture (strictly speaking) of Silex and pure
Argilla, and is often so called when the Quartz contained in it amounts te
sixty, or even ninety, per cent.
ity!
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nig
208
Mar. 11807. Publish by Ja? Sowerby Londm ,
TAB. CCVITII,
SILEX Quartzum.
Laminated Quartz.
Div. 1. Crystallized.
EE
Tuer more we become acquainted with Mineralogy, the
more we have to admire.
The nuclei of crystallization often form in plates ; but,
in the present instance, it should seem that, by some in-
terruption of a particular nature in the dissolving men-
struum, the crystal could not be formed so smoothly and
regularly as is common with crystallizing Quartz, and ¢ab.
i99 shows that it may be mixed with much foreign matter
without altering the regularity of the crystallization. Thus
the present subject is the more remarkable. This sort of
Quartz has been found pretty frequently at Glassteining, in
Cornwall, but I do not know that it has been found else-
where. It has often Tin and decomposing Felspar about
it; and whether these or any other decomposable substances
have been originally formed with it, and have since caused
its decomposition, as seems to be partly the case with the
Pebbles at tab. 103, either way it is a curious circumstance,
and may lead to some useful truth in the investigation of the
16
nature of Crystallography, or to some other part of
mineralogical science.
These are the usual eighteen-sided crystals, interrupted
in a peculiar manner.
The right hand figure is in plates a little oblique to the
base of the pyramid, or to the transverse section of the
column. The middle figure shows them still more oblique ;
and the left hand one shows the lamine disposed length-
wise to the column, with an interruption of another set of
laminz towards the top. Zhe upper figure has many
other varieties.
Most of the specimens which Ihave received of this
curious subject are by favour of that warm friend to the
science of Mineralogy, Philip Rashleigh, Esq.
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May 11807. Publisha bv Ja? Sowerby London .
17
TAB. CCIX.
ARGILLA electrica.
Tourmaline, or Schor!.
Class 2. Earths. Order 1. Homogeneous.
Gen. 4. Argilla. Spec. __ electrical.
Syn. Tourmaline. Kirw. 1. 271.
Le Schorl. Broch. 1. 226.
Schwarzer Schorl. Lmmerl. 1. 95.
Tourmaline. Hawy, 3.31.
Borax electricus. Linn. Syst. Nat. ed. 12.
ty os, 96.
‘Tuts substance I have received from my friends Dr. Penneck
and Mr. Dunkin of Penzance, found in that neighbourhood ;
and I have gathered some curious curvilinear varieties of it
at the Logan Rock. I have also been favoured with some
aggregated kinds, by the Rev. Mr. Neck, from Devonshire.
The specimen here figured was received from the former
gentleman, and is somewhat remarkable for the largeness
of the crystals *, though they are somewhat confused ; but
more so still, from one end passing by fine straight fibres
into the Quartz which accompanies it, giving it an ap-
* The crystals are found more perfect at the Brazils, in Spain, Switzer-
land, &c.
VOL, III. Cc
18
pearance of a termination. The crystallized end is shown
at the upper part of the geometrical figure on the left hand
of the plate, and the other end on the lower part of the same
Jigure in fibres.
The other figure is one out of a gangue of Mica from the
neighbourhood of Aberdeen. These crystals are net very
regular, but are remarkable for holding small Garnets, im-
bedded in them ;—s¢e the lower figure.
Tourmaline is by some authors said to be distinct from
Schorl, whilst others consider these substances only as
varieties of each other. In some instances they appear to
be distinct, especially when sufficiently large; but of this
more shall be said hereafter.
Tourmaline generally presents straight prisms *, mostly
blackish or dark-coloured, sometimes showing a greenish
or brownish colour at the transparent edges or flaws. My
specimens from the Logan Rock are greenish, but those
imbedded in Mica are brownish. Some foreign specimens
are remarkable for varying their colour according to the di-
rection in which they are viewed. Tourmaline is well known
for its electrical properties. The crystals have mostly a rich
gloss, are smoothish, with more or less numerous striz
- placed longitudinally on the prism, and horizontally on the
pyramids, excepting when they are approaching to fibrous,
as below observed.
* Sir John St. Aubin is said to have in his possession a crystal without
a prism—a great rarity.
P er y
May vibo7 Publisha by Ja! Sowerby, London.
19
TAG COX,
Tue present specimen is part of a large aggregated * mass
sent me by the Rev. Mr. Gregor from’ Cornwall, and is
composed of numerous crystals forming several distinct
varieties, where they are ‘not confusedly intermixed with
each other. It seems to have been found in the vicinity of
a red Oxide of Iron, as the colour about it indicates. In
Mr. Gregor’s account of the analysis (Nicholson’s Journal,
vol. 4. 312), it appears that it contains Oxide of Titanium.
It is somewhat remarkable that the red Schorl of Siberia, and »
the large specimen of Rubellite or Titanitet (as it has been
called) in the possession of the Right Hon. Charles Gre-
ville, are by some considered as varieties of Tourmaline.
The crystals in this specimen show many of the faces
which are generally found on Tourmaline ; viz. the three-
sided prism, truncated at the edges, and formed into a six-
sided prism; the same with two or more bevillings on the
edges, &c.—The fracture is somewhat conchoidal, and the
- primitive form is a rhomboidal parallelopiped.
Tourmaline is harder than Quartz. ~ With moderate heat
it becomes electric, attracting and repelling ashes, &c.t, a
__ * Schorl is said to be mostly aggregated, and Tourmaline to be chiefly
imbedded in single crystals.
+ This was presented to Colonel Symes by the king of Ava, and is said to
be worth a thousand pounds.
_ ¢ Foreign specimens, sometimes cut and polished, are known by this
property.
Cc 2
20
property said to be in Schorl, Bergm. 9.124. Kirw. 1.272.
The latter observes that Bergman thought Lime essential to
Schorl in the analysis of that of Mount Albans, which Mr.
Kirwan says was probably Hornblende.
Mr. Kirwan asserts that Schorl was named so from its
brittleness ; others say from the village Schorlow where it
was first noticed.
Analyses of Tourmalines by Bergman.
Of Tyrol. Of Ceylon. OfBrazil.
Aregill . e e 42 e e e 39 e e & 50
Silex ° e e AO ® ° ° 3 7 e e' 8 34
Caleareous: Barth 12h ae ae. aad
Bron a ee ee ee Or oo oat ay
100 ; 100 100
=e eee =
Analysis of the Tourmaline of Brazil by Vauquelin.
Dilexcee cack eh OOD
Alumine;..- . . 39°00
Lime WR re nee nol!
Oxide of Iron |, 42°50
Oxide of Manganese 2°00
Water 2 Yarns ica eb
100°00
——
2H
May 13607.Publisha bv Ja’ Sowerly Londo.
VAR CUXxt.
SILEX Petuntse.
Feldspar and Petuntse.
Class 2. Earth. Order 1. Homogeneous,
Gen. 4. Silex. Spec. _ Petuntse.
Dw. 1. Crystallized.
Syn. Feldspath. Delisle, 2.445. Emmerl. 1. 226.
Feldspar. Kirw. 3177.
Feldspath. Hazy, 2. 590.
Spatum campestre. Linn.
Fexpspar is a very common substance, chiefly found in
ageregates of various descriptions. It is observable in the
granites which come from Aberdeenshire to pave the prin-
cipal highways in this metropolis, and remarkable in the
Moor Stone of Devonshire on London and Westminter
bridges, where the imbedded crystals are very bold and
distinctly seen, especially after rain. The present speci-
* men comes from near Monymusk in Aberdeenshire, by
favour of my kind friend Mr. James Reid. The crystals,
being nearly independent, allow us to see their determined
form distinct from the gangue, which is more confused
Feldspar with Quartz and dark crystallized Mica, forming a
Granite. The little middle figure was easily detached, and
makes a short six-sided prism. I haye put a geometrical
22:
figure of it at the bottom of the plate on ‘the left hand,
showing the form of the fractured rhomb, and the lower
side of a prism with a triangular face, formed of a bevilling
from the edge of the sharpest angle of the side of the
truncated end, as in the little middle crystal, which also
shows the parallel fractures. or flaws. The right hand
modification is rather more common; viz._a six-sided co-
lumn with two terminal faces, one primitive, or parallel
to the fracture of the crystal, as in those before spoken of ;
and two directly opposite, forming at each end of the prism
one primitive face and one opposite truncation, alternating
with those at the opposite end.
These are of the usual colour, viz. a lightish red*. They
are almost too hard to be scraped with a knife, but Feldspar
varies much in hardness 3; the crystals in the Moor Stone on
Westminster bridge stand above the rest of the stone, are
consequently of a harder nature, and do not wear so fast.
In other instances it is found decomposing, soft, and nearly
powdery f.
The primitive faces, or sides as it were, of those figured at
the apex and base of the crystals, fracture smoothly and with
facility., The other four break irregularly or roughish, The
former generally show some sparkling illinitions, which are
very apparent in some specimens, and serve to distinguish
which of the terminal faces is the primitive one.
* White or transparent Feldspar, being found at Adula, is called Adularia
Moon Stone, Feldspath nacré.— Hazy, &c.
+ This is often called Kaolin, and is frequently found in China manu-
factories.
a2
May 12507 Publish a by Jas Sowerly London.
May 41607, Publishd by Ja? Sewerby,London.
TAB. CCXII.
Tis pretty specimen was sent from the same place as the
last, and is of rather an unusual colour and appearance ;
having additional bevillings and truncations; viz. two on
each of the more obtuse edges of the prism, forming four
_ additional faces, and making in all ten faces to the prism
and two small faces on the apex. |
Feldspar differs in specific gravity from 2°272 to 2°7045.
Under the blowpipe it melts into a whitish glass without
addition. It also varies in analysis, containing
Silex: trom .)7. «42 4to7@
Alumine . . : 14 — 37
Lime, sometimes Oxide of Iron, and also Potash ;
Barytes and Magnesia, according to Mr. Kirwan.
TAB. CCXITI,
Pernars one of the most curious circumstances which ~
happens in this substance, is that of its crystals macling,
which in this specimen they most truly do, according to
the literal sense of that word, as distinguished from the
hemitrope*. The present specimen is of a peculiar kind,
* A crystal one half of which is turned upon the other.—Haizy,
24,
from the neighbourhood of Aberdeen, and may assist in
explaining those of the same nature when they occur. It
is part of a large crystal, which includes some Quartz and
a few sparks of Mica, appearing at first a rude mis-shapen
portion, to which I have added the outline for explanation.
The crystal is formed of two similar halves of different
crystals, locked as it were into each other ;—see the zigzag
line No. 1.
The lower left hand figure represents a single crystal, in
which the same faces are seen as are mentioned in tab. 212;
the largest terminal face being the primitive one ; but the
small faces are greatly increased in size. If this crystal were
divided in the middle in the direction of the dotted line,
and one half turned round, it would not be in the least
changed in form, answering nearly to Haiiy’s remark, 3. 602.
The right hand figure is formed of two halves taken from
the similar sides of two different crystals. (or, which is ex-
actly the same thing, of two pieces cast in the same mould),
each exactly corresponding with one half of the left hand
Jigure. In this the primitive face is divided into two parts,
and each part is brought to correspond with part of a
secondary face, fig. 2, but may be easily distinguished by
the fracture.
214
May 11807,Publishd by Jat SowerbyLo ndon.
es
Or
TAB. CCXIV.
Dr. Bucuanan, whose researches in the East Indies are
well known, brought me some of the Breccia Rock, from
Callender in Scotland, in which I found pebbles of Feld-
spath. As Feldspar of this description has not, to my
knowledge, been before noticed, I am pleased to have an
opportunity of showing it here, where I have added some
other amorphous Feldspar, known by the name of Petuntse
in Scotland, found in various parts of the Pentland Hills,
south-west of Edinburgh. This is of some esteem in ma-
nufactories of porcelain, being a fusible composition of Silex
and Alumine, but varying in the proportion or quality. It
often disappoints the workmen that gather it, as well as
the manufacturers, and Quartz nearly pure has been sent
to them as Petuntse, especially for the white or gray sort,
which has least Iron, and would consequently be of most
value for their purposes.
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27
TAB. CCXYV.
SILEX Quartzum.
Flints.
Class 2. Earths. | Order 1. Homogeneous.
Gen. 4. Silex. Spec. 1. Quartz.
Div. 2. Imitative.
Mz. WarzuRTON was so good as to bring me a specimen
of this curious flint coralloid found at the bottom of the
chalk-cliff on the eastern side, at Rottingdean in Sussex,
where it is said to be very abundant. It is almost always
the nature of flint to be formed into some shape expressive
of its having been in a state of solution. This is every
where evinced by the various substances it has taken pos-~
session of, but the distance of time since this happened
cannot be positively ascertained ; for although it is in a
sort of stalactitic form, running like a gelatinous substance,
yet it is always in a hard state, and looks as if it were
almost recent, although it may have been for many ages in
the same state. I have a piece of Coral from the neigh-
bourhood of Bristol, by favour of Thomas Meade, Esq.,
which has Flint and some Calcedony passing into its in-
terstices.
25
We figure these things that a subject of such universal
inquiry may no longer remain in obscurity. Animal re-—
mains, especially the more earthy, such as corals, have left
such various impressions * that it requires many specimens
and much experience to recognise them.
The figure No. 1. is from Sussex. No.2. was sent me
with some others by my kind friend Colonel Walford.
No. 3. I found with others of the same sort at the Isle of
Dogs. No. 4. shows the inside of the same, and No. 5.
was picked up in a gravel pit at Kennington.
* Some have considered these as parts of Mushrooms, such as Morels, &c.
petrified, and I have one that has been compared to a marrow and bone;
whichit much resembles in form, sent me by the Rev. Dr. Sutton of Norwich.
J have another which I found near Dulwich, which might very well be
taken for a petrified Agaricus, showing, as it were, the impressions of the
edges of the lamelle, three or four inches in diameter and eight or nine in
circumference.
6
May 2.1607. Lublish a by Ja? Sou aby hinten «
TAB. COXVE.
CUPRUM nativum.
Native Copper, Leaf-lke.
Class 3. Metals. Order 1. Homogeneous.
Gen. 10, Cuprum. Spec. 1. Nativum.
Div. 2. Imitative.
‘Tas curious specimen of Copper nearly in a pure state,
and commonly called Native Copper, comes from Huelvor
near Redruth in Cornwall. It is an excellent example of
the manner jn which the Copper was held in solution, and
the solvent subsiding from it, leaving it in a state to explain
the nature of the’ particles cohering, while supported by a
sort of reciprocal gravity in the solvent, which allowed it
to expand almost in distinct nuclei, by masses in the form
of leaves, resembling vegetation, teaching us a beautiful
lesson to explain the changes and formation of mineral
substances*. I do not know that the rhomb, perhaps pri-
mitive rhomb, of Copper has been before noticed ; it seems
in this instance to form into the octaédron ;—see the left
* Mineral substances approach vegetation more perhaps. than has gene-
rally been suspected, and may throw a light on that subject which has
hitherto been -a desideratum, or very obscurely understood. The pre-
sent specimen resembles the Fucus Hypoglossum, or ruscifolius, in the leaflets
coming from the middle of the larger foliage.
30
hand figure. The other figure exhibits the two sides of the
plates chiefly formed of rhombs, showing as it were the
under view. We could not measure these with any cer-
tainty, as they are very much interrupted and irregular.
We, however, think it very interesting. The octaédron,
—see the left hand figure—and the rhombs in its direction
seem to agree with the Native Coppers, and partly modify
hexangular plates as they partly do in these specimens, and
into consequently into double hexaédral pyramids ;—see.
Vol. 1 tab. 25. |
I have the pleasure to say that I possess a small sample
of this very curious Copper Ore, by the favour of my kind
friend Philip Rashleigh, Esq., marked by him from
Treskerby, Cornwall.
Apriibo7 Lublisha by Ja! Sowerky, London .
Co
Ca
TAB. CCXVII.
-CALX carbonata, magnesiata.
M. agnesian. Limestone.
Class 2. Earths. Order 1. Homogeneous.
Gen, 3. Calx. Spec. 5. Carbonata.
Var. Magnesiata.
Dw. 1. Crystallized.
Syn. Magnesian Limestone. Zennant in Phil. Trans.
1799, part 2.
Mr. Tennant having favoured me with specimens of the
stones spoken of in the Philosophical Transactions for 1799,
I feel a pleasure in presenting so useful a subject to the
public under such authentic circumstances.
The upper figure is what may be called the petrified re-
mains of a shell, and is of a remarkable construction, espe-
cially on the hinge end. It has something of the ap-
pearance of an Arca, but is very different, however, from
any that I have before seen, either petrified or recent. It
was a curious circumstance that caused Mr. Tennant’s in-
vestigation of the nature of these Limestones ; for he ob-
served in Mr. Marshall’s Account of the Agriculture of the
Midland Counties, that the Limestone found at Breden,
near Derby, is destructive to vegetation. His experiments
confirmed this account; and he found it to depend on the
Magnesia, of which it seems that this Limestone contains
about a fourth part. He further remarks, on the authority
of Dr. Fenwick of Newcastle, that the farmers in that
VOL. Ik. D |
34
country divide the Limestones into hot and mild. The
former, he savs, is no doubt magnesian, as it has similar
effects on the soil, and is not so easily dissolved in nitric
acid as the latter *. A little better acquaintance with these
substances may make them known without analysis; and I
have little doubt but that the farmers and their men, in the
neighbourhood of the hot and mild Limestone, have some
more or less intelligent way of distinguishing the one from
the other, so as not to mistake—as lapidaries can tell white
Agates from white Carnelians, although they confess they
cannot tell how. The present specimens have a granular
appearance, and, upon careful examination, are found to
contain, or are indeed almost wholly formed of, little
crystals agreeing more or less with the more perfect Pearl-
spar—see ¢al. 19—and show the rhomboidal sides some-
times tolerably distinct t+. The shell at the top of the plate,
and the brownish piece in the middle, from Breden, as also
the whiter piece below, have in these particulars the same
structure.
* One of the properties of Magnesian Limestone is its slow solution in
Nitric Acid.
+ Thus Mr. Tennant has discovered Pearl-spar to contain Magnesia ;
which in part corrects Bergman’s analysis of that substance, whence so many
mistakes have arisen. Heavy Limestone or Dolomite of Tirie he finds to
contain Magnesia in a larger proportion than above.
Tuby 22603 Publish d by Jat Sowerby London,
35
TAB. CCXVIILI.
SILEX Quartzum; var. Jaspis.
Red Jasper.
Class 2. Earths. Order 1. Homogeneous.
Gen. 4. Silex. Spec. 1. Quartzum.
Div. 3. Amorphous.
Syn. Quartz Jaspe rouge. Hawy, 2. 436.
Gemeiner Jaspis. Emmerl. 1. 243.
Jasper. Kirwan, 1. 309.
Silex Jaspis. Linn. Syst. Nat. ed. 13.
Green Jasper, or Ribband Jasper, has been figured at
tab. 157, of this work. Red Jasper is also found striped,
veined, &c. The present specimens are, however, the
most usual of the red kind in Great Britain. The upper one
came from a gravel-pit*, commonly so called, which has”
a large and curious variety of stones in it, from whence
most of the old pavement of the city of York is composed.
I am obliged to my kind and indefatigable friend the Rev.
J. Dalton for this, and some other very curious specimens
from thence, cut and polished; and it is nota little cu-
rious to knew that the lapidaries of York have been a long
time employed cutting these stones, which they call
Marbles +, some of which are, however, as hard as Oriental
* Gravel-pits near London hold only common Quartz and Flint Pebbles of
different sizes—see p. 88.
+ Any largish stones, not Gems, are pominolky called Marbles. I think,
however, that this name should be confined to such stones as masons can
polish without Emery, as the Marble of Italy.
D 2
86
stones. The present, like most British specimens, are
more porous than the Oriental ones, but in other respects
are the same, viz. Quartz mixed with Oxide of Iron and
Argill. It is very handsome, and takes a good polish.
Stones of the same sorts are found on many of our coasts,
but are still more porous, and veined with opaque Quartz,
&c. The lower specimen is from Devonshire, sent by my
friend G. Montague, Esq. I suspect they fall from near
the Serpentine Rocks, and that the red Serpentine may be
traced from the softer state to the indurated or harder Ser-
pentine holding Jasper, and may thus have been occasionally
confounded with it. Serpentine may generally be scraped
with a knife; Jasper, I should think, never: and it is perhaps
worthy of observation, that different states of red Serpentine
resemble Brick ; and some curious persons have picked up
these in various states from that resembling soft Brick to
Jasper, considering them as Brick passing from the more
soft beginning of petrifaction to the more hard and stony.
uly 21807, Publish ty Ja! Sowa, onion.
37
TAB. CCXIX.
SILEX Quartzum; var. Jaspis.
Jasper.
Class 2. Earths. Order 1, Homogencous. _
Gen. 4. Silex. Spec. 1. Quartzum.
Div. 1. Crystallized,
Syn. Iron Flint. Jameson, v. 1. p, 134.
Eizen Keisel. /WVerner.
a
Tus has an appearance so peculiar, that it may be readily
distinguished when once seen, although on careful exami-
nation it will be found to differ very little, if at all, from
the other coloured Jaspers, either in its nature or compo-
nent parts. It is said to be crystallized, like Quartz, with
the pyramids terminating in three faces, and sometimes
with the other three belonging to Quartz very small *. The
fact is, that this substance is no other than Quartz with a
red or yellow Oxide of Iron, and is often partially crystal-
lized, though sometimes otherwise with an appearance
rather peculiar, which occasionally resembles a coarse red
sealing-wax, or the cement used by lapidaries, made of
pitch, resin, and brick-dust. Its hardness is the same as
that of Quartz. Its peculiarity at first sight has been suf-
* We have independent crystals of Quartz from Matlock, &c. of the same
form.
38
ficient to make those who have found it, and who were
pretty well versed in the science of Mineralogy, inquire
what it was ; and Werner, I suppose, seems satisfied that
it ought to have aname which might distinguish it.
The specimen figured comes from Bristol, and I have
some also from near Keswick, in Cumberland. I believe
it is not very rare. The lower geomeirical figures are in-
tended to show the forms of the crystals as above men-
tioned.
i: ns
Tilly.11807 Publish. by Ja Sowerby London.
Zz
20
ee
SS
39
TAB. CCXX.
SILEX Quartzum.
Variegated Flint Pebbles. :
Class 2. Earths. Order 1. Homogeneous.
Gen. 4. Silex. Spec. 1. Quartzum.
Div. 3. Amorphous.
\
Some time since Mousehold Heath, near Norwich, afforded
much entertainment from the varieties of stones found near
Kett’s Castle, such as Petrifactions of Echini, Geodes, and
variously marked Flint Pebbles nearly resembling the Egyp-
tian Pebbles, or Jasper, as it is called by Kirwan, &c., it
bearing much the same affinity to that, as the British do
to the foreign Jaspers, being more porous and ordinary as
to hardness, &c, It, however, may often serve as amuse-
ment toa fertile mind in furnishing it with whimsical shapes ;
and it is astonishing to see what a difference there is in
the fanciful ideas of the many curious forms observable in
these stones, at different times. However, it may happen
that the lines give so general an appearance of a face, even
a likeness of a known character, that they have met with
an almost universal approbation and agreement, and are
-valued accordingly. The present specimens are rather
curious examples of the first mentioned, and rather undeter-
mined in my mind, yet may be more clear to others. Thus
the left hand upper figure is like a monster, something like
a boar, which, when turned the other side upwards, re-
sembles a Rabbi’s head. The right hand upper figure
is something like a tiger. Those at the botiom nearly speak
for themselves. The oval one is a boy; the other, like a
distresed mariner reposing or leaning on a rock,
a tt
A warts date a9
Sly 1.2807. lublisha by Jas Sow erty London.
7 < J z
Al
“TAB. CCXXI.
SILEX steatites; var. induratum.
Red and Green Serpentine.
Class 2. Earths. Order 1. Homogeneous.
Gen. 4. Silex. Spec. 13. Steatites.
Div. 3. Amorphous.
IT po not much admire the name Serpentine, nor do I
think it very appropriate to this substance, and it has in-
deed been the cause of much confusion, as different states
of Jade, Asbestos, and Actynolite have been mistaken for
it. I should rather consider this substance (which has
generally been called Serpentine) as a variety of Steatite
more or less veined with the help of Oxide of Iron, often
red, and of the colour of brown Bricks, as in some parts
near the Lizard Point, and Kynance Cove, where the rocks
are massive, and of a dark green on the outside, but when
broken look within of a brick-red, and the varieties found
about the Lizard Point are veined with red and different
greens, The upper specimen was obtained from thence by
favour of my kind friend P. Rashleigh, Esq. and is chiefly
green veined with red and a bright silky red interspersed,
which is reckoned rather rare. There are also bricht plates
of a substance about it which is considered by some as a
sort of crystallization of the Serpentine, and is called by
the general name of Schillerspar. The lower specimen is
such as is found at the Lizard, Portsoy, or in Wales, and
is in part approaching Jade*, but is much softer. This
and its varieties often include the silky Asbestos ;—see
tab. 123.
* Jade is hard and tough, or it would not answer the purpose of Hatchets
to the New Zealanders.
Tully 21807,Publishd by Jat Sowerby.London
AS
TAB. CCXXITI.
SILEX - steatites.
Soapstone, or Soaprock Steaiite.
SreaTITE, commonly called Soaprock, is found in Norway
and China, as also at Portsoy in Scotland, and at the
Lizard Point in Cornwall. It is found of a fine waxy white
like white hard soap or Windsor soap, and feels so similar
to the touch as naturally to assume that name. It is occa-
sionally coloured yellow, often so as to resemble common
yellow bee’s wax; it is also occasionally dendritically co-
loured with Iron Ochre or Manganese, from light yellow,
light gray, &c. to red or crimson, as figured. The whitest is
of course preferred in Porcelain, for which it is often used. It
is found of various degrees of hardness, from such as is easily
scraped by the finger nail to such as can scarcely be scratched
by a pin. It, however, hardens in the fire, according to
the time of exposure, until it will scratch glass like Quartz ;
the more transparent becomes opaque, and if polished
before putting into the fire will retain the polish after
heating. The coloured varieties are affected by heat ac-
cording to what the colouring matter may be. I suspect
that this may be the Hoa-che of the Chinese, which has
superseded the Kaolin; but so far as I have seen they do
not understand it so well, although the china made from
it is said to be better in some respects, I believe it is better
AA
understood in England. It may be chosen so as 10 be cut
easily into any form, and the Chinese use some varieties -
for carving figures and very delicate fret-work. The softest
might serve this purpose as well as the hardest sorts, and
either might be hardened afterwards by heat.
The upper kind comes from the Lizard Point in Corn-
wall, and is found in veins in the Serpentine Rock. The
lower piece is extraordinary for the strata of colours, which
perhaps are as vivid, and distinct, as will ever be found in
this substance. I have another specimen, by favour of my
friend the Rev. H. Davies, with Magnetic Iron in it ina
small quantity,
ies
aM ee
BI897, Publish by Ja? J
July
AS
TAB. CCXXIII.
SILEX §steatites; var. indurata.
Indurated Steatite.
Perrnars this substance may have so much resembled
Porcelain, that when polished it might be mistaken for na-
tural Porcelain, and it may possibly be very nearly the
same in regard to the component parts, especially with that
which is made of Petuntse and Kaolin. The present specimen
from Portsoy must be allowed to be softer than the Porcelain,
but would nevertheless become harder by being heated. It
is chiefly composed of Silex, Alumine, and Magnesia, like
the last substance, but in a harder state, and the tints may
give a lesson for a new way of preparing colours, if that
were necessary, and may indeed be useful, though the
colouring of Porcelain is now tolerably perfect. ~The co-
lours in this seem chiefly to depend on Oxide of Iron in
different states; thus the yellowish hue is owing to a
mixture of a pale yellow Oxide in” a small quantity, and
the red to a mixture of very deep Oxide of Iron; but the
green may arise from a mixture, as it were, of Chlorite. |
This is sometimes intimately mixed with Steatite, and is
curiously dispersed ‘about the present specimen in lines,
spots, &c. Indeed these and the larger yellower spots are
nearly the same in appearance with the Hatchet Stone of
the Leeward Islands, called Nephrite, Jade, &c.; but
46
known by its greater softness as Serpentine. This, there-
fore, includes a very interesting lesson, and I am obliged
to Earl Seaforth for so handsome a specimen.
The lower specimen came from North Wales, and was
sent me by the Rev. H. Davies: the Chlorite which holds
some Pyrites in the veins or marbling of this, and the
Pyrites with the rest of the substance, are not far from
agreeing with the Meteor-stones.
Steatite and Serpentine differ but little except in the
colour, which seems much to depend upon Iron. Steatite
has been found in secondary crystals, chiefly im the form of
those of Quartz.
eS Sy
3 : Suly7.1807.Pubisnad by Sa! Sowerby London.
,
t
'
»
i
AT
TAB. CCXXIV.
SILEX Petuntse.
Kaolin.’
Tuts substance (found at St. Stephen’s in Cornwall, &c.)
has long obtained the name of Kaolin because of its re-
semblance to the Earth so called in China, on account of
its being used in Porcelain manufactories, and is by some
considered as necessary to be used with the Petuntse for
hardening the mixture for the better sort of Porcelain. It —
is a kind of decomposed Granite, being an aggregate of
Feldspar, Quartz, and Talc, and is, for some purposes,
ground up together to make Crucibles, but it depends upon
the proportion of the three ingredients to determine how it
may best be used. If carefully separated and washed, the
decomposing Feldspar, with what Talc and perhaps fine
Quartz are among the washing, make the Porcelain Clay,
(Feldspath argiliforme of Haiiy,) commonly so called, and
the difference observed by Wedgewood, viz. of 60 parts of
Clay and 10 of Quartz, depends upon circumstances that
seldom allow any aggregate rock to be very regular.
Authors differ in the analysis thus :
Silica from Aas 52) ito 471
Alumine . elon tO ail
with occasionally a little Lime, Magnesia, Sulfate of Barytes,
and perhaps Iron, which may sometimes give a redness
more or less common in Feldspar.
One of its characters is, to be infusible: this, however,
may depend upon the proportion of the mixture. Some
say it is infusible in a porcelain-heat; others say, nearly
infusible in the greatest heat of a porcelain furnace. Ac-
cording to Achard, Kirwan, v. 1. p. 58, determines that
AS
Argil and Silex are infusible in all proportions. Kirwan,
v. 1. p. 66, says, three parts of Argil and three parts of
Silex with one of Magnesia form a Porcelain. Other pro-
portions of the same substances remained as a powder,
hardened only or formed a Glass, porous Enamel, Porcelain,
&c. This shows the necessity of having a knowledge of
the nice distinctions sometimes necessary in comprehend-
ing nature. It was with a Clay of this kind that Wedge-
wood formed his pyrometers; but it is said that after the
mixture was exhausted he could not venture to make any
more, as he could not find Clay that he could depend upon
as having the same proportion of parts, and consequently
could not produce any precisely of the same standard.
Earths of this kind are found wherever Granite rocks
occur in a decomposing state in greater or less abundance,
differing in the size or quantity of the different ingredients,
the Quartz in large or small grains, with more or less Talc,
which holds Magnesia, and perhaps helps the decomposi-
tion when in contact with the air, which last seems neceés-
sary, as Granite is never considered as Kaolin till thus de-
composed, although perhaps containing the same sub-
stances. It is curious to remark that these substances,
afforded by nature to snit our particular purposes, are ge-
nerally known by some external characters which distin-
guish them in a general way, and those used to it do not
care to venture on any other. In this instance the substances
may vary much, as is seen by the analysis ; and perhaps
the less decaying rock might, by affording a more suitable
proportion of parts, sometimes answer the purpose better,
The decaying rock 1s, however, more easily gathered. This
may be convenient to be known to those whose estates are
contiguous to the other’necessaries for percelain manu-
factories.
The specimen figured shows irregular spots or grains of
Quartz, with some shining greenish particles of Tale ; the
remainder is chiefly Earthy Feldspar or Petuntse. .
Sapt.2.1607. 2ublixid by Ja* Sowaby London.
Zee.
49
TAB. CCXXV. |
ARGILLA cyanea.
Cyanite.
Div. 1. Crystallized.
Syn. Sappare. Saussure, Journal de Physique, Mars
1789. 213. Kirw: 1. 209.
Cyanit. Lmmerl. 1. 412.
Disthéne. Hawy, 3, 220.
Tuts beautiful and curious substance is said generally to
occur in primitive mountains abroad, and in Scotland. The
present specimen, from near the Grampian Hills, Kincar-
dineshire, is nearly of the best or deepest colour: few are
deeper; and specimens are occasionally almost colourless.
We do not approve the name of Kzanite or Cyanite, taken
from its colour, as it does not serve to distinguish this
species from other blue minerals. The name Sappare also —
confounds it with Sapphire; and again, Cyanite is very
similarly sounded, by some, to Sienite, which is an aggre-
gate. We have placed this stone in the genus Argilla, to
which analysis plainly shows that it belongs; and we have
also made use of Cyanite as its trivial name, for it is
scarcely known by any other. We have quoted a part of
Haiiy’s description, as most applicable to the substance.
The crystals may be divided by two cuts inclined upon one
another, at an angle of about 103°, one of which is much
neater than the other. Spec. Grav. 3°517. A very sharp,
VOL. Lt. E
50:
pointed piece will scratch glass, and may be scratched by a
steel point upon the large faces of its lamine; but not upon
the lateral ones. The refraction is simple. The primitive
form is an oblique quadrangular prism, of which one plane
is inclined upon the other, at an angle of about 103°.—
Integrant molecules the same. Infusible without addition.
Seldom shows any determined crystal, at least among
English specimens.
Analyses by Saussure, by Lauguier.
VERBAL oo) BT hs ey ooo | ee
IGA eens BO eels wh ee ee
Weta Ho Nay inal eae y Gum Rae
Nig raest e754 seh ou oon
Oxide of ron 9 6 |. cal causa ae Bee
Water ergy oT Re OC? Ses lien
Fly 1807 Publish bu Ja! Soweriy London.
ol
VA B..CCXXVI.
SILEX wmagnesiatus.
Common Asbestus.
Div. 2. Imitative.
Var. Fibrous.
EE
‘Tuts substance has been long known in the Isle of Skye.
I believe it has not been discovered in Ireland, but may
perhaps be found in North Wales. The length of the fibres
in the present specimen gives it a remarkable appearance,
and the leek-green varieties but faintly convey the idea of a
stone, particularly in a figure. It is scarcely flexible, except
in very small fragments, although it has that appearance,
especially the middle twisted piece. It is finely fibrous in
its divisions in some parts, in others rather solid and
plated. Fragments splintery, breaking with hanging fibres.
Lustre rather internal, partly pearly. To the touch it is
smooth and softish, scarcely greasy; is readily scraped
with a knife, and is somewhat transparent at the edges.
The lighter left hand specimen is more solid, and mixed
with the amianthine rock, in a curious semi-detached
manner; breaking at right angles. The varieties between
these may include most known, as there are but small dif-
ferences. It sometimes approaches Lapis nephriticus,
which is more solid, tough, and hard.—Spec. Grav. from
2°547 to 2°995.
EQ
yer ne
ivy me
53
TAB. CCXXVII.
Dark green wood-like Asbestus.
Div. 2. Imitative.
ee
Common Asbestus sometimes resembles rock-wood—
see page 124—and is often very different in appearance, at
first sight, from the preceding figure.—It is therefore
sometimes gathered in masses to be cut and polished by
the Lapidaries, when the light refracted through the flat
face, from the fibres, gives it something of a chatoyant,
satiny, or pearly lustre, which is much admired, especially
when some of the fibres, curving into concavities, are re-
lieved by those in a contrary direction, or by the dark ends.
This ‘specimen has some Talc, Pyrites, and Magnetic Iron
in the lower dark part, which give it a curious appearance,
especially where the Talc is prominent.
tug u1b07Lublisht by Jas Sowerby, Lonion~
TAB. CCXXVH1.
SILEX | fragilis.
Actynolite.
Class 2. Earths. Order 1. Homogeneous.
Gen. 4. Silex. Spec. _ Fragilis.
Div. 2. Imitative fibrous.
Syn. Strahlstein. /mmer/l. 1. 418.
Actynolite. Kirwan, 1. 167, 178.
Actynote. Hatiy, 3. 73.
Mr. Kirwan seems to have givenan excellent description of
this substance, perhaps the best extant. I shall, therefore,
make use of the following applicable part of it: ‘* Frag-
ments long, splintery, and exceedingly sharp, so as to be
dificultly handled without injury. Hardness difficult to
estimate, on account of its brittleness.”” He also says,
«We may vindicate to this species the stone called by
Saussure Schorle en fillets brillants et fragiles ; so sharp as
scarcely to be handled with impunity.” In these characters
it is certainly peculiarly different from any other species of
_ Mineral, and its particles are so fine and sharp as to put
me in mind of the setaceous spiculz or hairs on the pod of
the Dolichos pruriens. We might even suppose it as good
an anthelmintic or vermifuge, by its mechanical action ;
but its hardness would undoubtedly make it too violent.—
It very readily penetrates the skin, and the consequent
irritation is more violent than the most troublesome itching,
56
as it gives an aching pain. I have, by favour of the Rev.
H. Davies, and the late ingenious Mr. W. Day, received
specimens ofthis Actynolite said to come from the Isle of
Skye, where it appears to be abundant, and in great variety.
—Spec. Grav. from 2°950 to 3903.
Saussure found in his specimen,
Sexton ones ORS
Arg, i me's seg 3O18
Magnesia . . « 0°1087
EME shea Ses OS:
Tron 2 2. OF01S
It is often largely or finely and variously striated and un-
dulated; it also varies much in colour.—Tab. 229 is a large
undulating dark-green variety. I have received beautiful
dark shining green Actynolite, mixed with Copper Ore,
from Maudlin mine in Cornwall, by favour of Philip Rash-
leigh, Esq., Dr. Turton, and J. G. Children, Esq.
2 areas cals
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5
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229
Aug 2.1807. Publish d by Sas JSowerky, London.
Aug.22007. Publishd by Jas Sowarly Loudon.
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59
TAB. CCXXXI and CCXXXII.
QUARTZUM talcosum.
Faller’s Earth.
Class 2. Earths. Order 2. Mixed.
Gen. 4. Quartzum. Spec. Talcosum..
Syn. Fuller’s Earth. Kirwan. Babington, 52.
Walker Erde. Emmerl. 1. 375.
La Terre 4 Foulon. Brochant, 1. 464.
Terra fullonica. Linn.
‘Tats valuable Earth is rather peculiar to Great Britain ; it
is, however, said to be found in Saxony, Alsace, and
Sweden. Hampshire and Bedfordshire are the only two
places mentioned in England by most authors. Dr. Thom-
son says, * It occurs in greatest perfection in the South of
England.” J, however, cannot find out that any has been
discovered in Hampshire 5 and indeed the analysis usually
quoted from Bergman does not appear to me to indicate
Fuller’s Earth*. His Grace the Duke of Bedford was so
good as to supply me with an excellent specimen from
Aspley ; and I have seen the pits in Surry and Kent. A
sori is also found in Nottinghamshire. I exhibit a small
* Tt isremarkable, hat of many acquaintances of whom I have inquired,
there is not one who can find out any place in Hampshire where it is found,
and I suspect something wrong in all that quote Bergman’s Analysis.
60
piece from Aspley, as above: it is the lightest and softest
in my possession, and has a character peculiar to the best
for use, viz. a semi-transparency at the edges, even when
dry, as I figure it. The lower specimen came from Nutfield
in Surry, which is less transparent at the edges when dry,
and is darker coloured, especially when in the pit, where it
is called b/ve, in a manner synonymous with Blue Clay*.
I have a Sandstone from the bottom of the Bedfordshire
pit, which has dark-green particles of Chlorite, such as is
found in Cambridgeshire, and in the Irish Mulatto-Stone.
I am told that under a surface of about six feet there are
several strata of whitish and reddish sand, under which is a
stratum of Sandstone, then a sandy Fuller’s Earth, called
Cledge, which is thrown away ; and that the proper Fuller’s
Earth is found at a depth of about 14 feet, when there is
some redder Fuller’s Earth, called Crop; the lower half of
the stratum is called JVall-Earth, and is reddish: but I
suspect this must vary according to time and circumstances.
The Surry Fuller’s Earth is found at different depths, as
from nine to twenty or thirty feet. At one place, upon a
hill, the surface was a wood; and when I examined the
Earth at the bottom of the plants, I found it full of semi-
transparent waxy particles with common light earth, and
some ferrugineous appearances: below this were different
strata of small stones, lying tile-wise, being flattish, and
some approaching Hornstone, with a ferruginous sand,
and green Chlorite particles: these are alternate, two or
* Dark blackish Clay. such as Tile-Clay, is commonly called Blue Clay.
61
three times, when larger and rounder stones succeed, whichi
are often Septaria, holding shells and petrified wood: un-
der these are small or large stones, flat and squarish, some
of three or four feet in thickness, and often arranged in a
very ordetly. manner, with squared joints, like a castle-
wall; between them are flat stalagmitical flakes, composed
of rather porous and light Carbonate of Lime, looking like
mortar, to help the deception. Often next to these are a
few small flattish stones and a ferruginous Fuller’s Earth,
which is sent to London for housewifery purposes. The
Earth below this has a dark blueish slate colour for six or
nine feet: this is brought out in lumps of from ten pounds
to a hundred weight, carried to a shed to be weighed for
sale, and in a few hours is placed in a waggon to send to
be shipped near London Bridge for Yorkshire. It may be
observed, that as it cracks in the pit by the access of the
external air, the outsides of the lumps become more or less
ochrey, as the second figure shows, and afterwards the whole
bleaches, and we cannot blacken it again; for, if it be wetted,
it becomes lighter still, and falls to pieces: this may depend
on the Oxide of Iron, and something carbonaceous. As
the Spec. Grav. of Fuller’s Earth is about 2, it is a curious
fact to understand that large masses of Sulphate of Barytes*
are found suspended in it; but of this more will be said
hereafter.
Kentish Fuller’s Earth, tab. 232, upper figure, is found
at present near Bersted, but not in abundance, like that of |
Nutfield, and is not above from three to six feet from the
* Whose Spec. Grav. is about 4-5.
62
surface, under mixed sand, and differs also from that int
being found with much water, and not being in large
pieces, or above half a pound, as well as. in requiring
careful picking and washing ; when it is laid out to dry,
and then shedded for carting to the Medway. It is rather
softer to the touch than the kind from Surry, but generally
dries darker, and has a more ochraceous crust. The three
sorts of which I have spoken have all a very similar fracture,
perfectly conchoidal, with a reverse inclining to the letter S. :
Nottingham Fuller’s Earth, lower figure, varies like the
others, but is generally more opaque and soft, rather than
waxy, in appearance. What has been sent me evinces the
admirable contrivance of Nature. The former varieties were
infiltrated through sand and between stones, whereas this is
preserved, as it were, in large nodules of red clayey Sand-
stone, and is thus as effectually distinguished as the kernel
of a nut.. I understand these are found in sandy rocks, and
that women and children strip the Fuller’s Earth of its co-
loured covering.
This earth is met with in other places, but I believe not in
sufficient quantities for market.
These specimens of this substance, from what I can judge
of them without analysis, are of the best sort, and should
seem to contain much Magnesia. Its waxy, soft, or
unctuous appearance would indicate it to be a Steatite Clay,
and its greenish hue certainly bespeaks the presence of Fale
or Chlorite, which is so well incorporated with it as to seemr
to help its granular texture. In fine, it appears a more de-
composed state of Steatite, like many of the neighbouring
eon
re)
stones; some having the whole composition, yet being in
the form of a granular stone; viz. whitish Steatite, green
granular Chlorite, Silex, and Clay. Some of the stones
found above it are coated with this, and are Flint, or Flinty
Hornstone, within.
Fuller’s Earth is more or less massive, dull, somewhat
granular. It does not soil the fingers, and may be polished
by handling, though more by the finger nail; particles in
grains, and on the edges, often admitting light, give it a
waxy transparency. It feels soft and greasy, is easily
scratched by the finger nail, cracks irregularly on drying ;
fracture large or small, conchoidal, deep, zigzag, sharp
and angular, sometimes broad and plated; roughens by
wetting, scarcely adheres to the tongue, becomes lighter on
drying, but if pressed before it be dry, nearly retains its
original colour; falls gently to powder in water, where it
~ feels soft, and does not stick to the fingers.—Colour light-
brown to dark-greenish brown, uniformly of one tint, of
rather accidentally spotted, striped and clouded, some-
times with talcose particles glistening in it. For sale it is
generally chosen as nearly uniform as possible.
As there appears to be some confusion among the authors
I have looked at for this Earth, I have thought it the more
necessary to be thus particular. |
Mr. Hatchett once intended to examine the Fuller’s
Earth chemically, and made much inquiry about it, but we
have to regret that he did not complete his experiments. He
informs me that he knew of none from Hampshire, and
that he believed Bergman and others had been led into a
mistake,
Lg
Oetr1607,PbichZ by Jat Sowersy,L ondon.
TAB. CCXXXITI.
CALX sulphata.
Sulphate of Lime, or Gypsum.
Class 2. Earths. Order 1. Homogeneous.
Gen. 3. Lime. Spec. 3. Sulphate of Lime.
SE
Gyesum, when crystallized on an amorphous gangue, is.
not very generally known, and has been very Iittle noticed
by authors; common Selenites only have been placed
among the crystallized varieties*.
The present specimen is from Derbyshire, where largish
blocks or lumps of amorphous Gypsum are found, often very
white, looking like fine Carrara Marble, and sold for va-
rious purposes, as making what some cal] Alabaster figures,
turned candlesticks, imitations of fruit, &c.+ When the
workmen are cutting it, they frequently find hollows in-
cluding the crystals; but these do not often come into the
hands of the curious. ‘The white face of the hollow has
often a snowy appearance, and is finely grained, upon
which the pellucid crystals look sometimes very beautiful.
The crystals are generally more clear and delicate than the
Selenite, not having clay among them; and this is all the
difference between them, since they are liable to the same
forms of crystals, which are composed of opposite trape-
* Crystallized Selenites—see tal. 67, are said to want a little Carbonate
of Lime to make plaister, but the other varieties have naturally a sufficiency.
+ The less solid pieces serve, when burnt, for casting plaister figures, and
for inferior purposes.
VOL. Ill. B
66
ziums, and are somewhat undulated, the same, with some
variations, as the figure beneath, which comes from Oxford-
shire, and is commonly called prismatic from its long
columnar appearance; this is evidently mixed with clay, as
the lower figure of tab. 67.
This sort of Gypsum is said to be found in masses of
different sizes, but seldom larger than three or four feet
in thickness; they are generally rugged, and broader than
they are thick.
The antients are said sometimes to have used the transpa-
rent Gypsum in the place of glass in windows ; whence it
has been confounded with Mica and Talc—see tab. 180,
181, &c., which substances are still often confounded,
although so distinct, as I presume this work now clearly
explains.
The temple of Fortune at Seia was built of this stone, and
without windows. The semi-transparency of the Gypsum
admitted the light, and Pliny said that the temple appeared
as if lighted from within*,
Some specimens of the crystallized kind have lately been
found at Alstone Moor on blende, &c., and by some means
got the title of Asbestos. They are sold in moderate pieces
for a guinea each, or perhaps more, as the dealers may be
more or less acquainted with the subject.
* Haiiy 3.290. In Warwickshire, Iam told that Gypsum has been used
for building the outside of houses; where it is burned with wood for that
purpose, and the whole mixed up together, giving it a greyish cast. It is
said to be extremely durable, and is carefully saved when a house is on any
occasion pulled down, asit is still more durable even if it has lasted centuries
in the first instance.
Ke
7 «
< Sowoky 2
8
get b07,Publisha ky
67
TAB. CCXXXIV.
Sprcu.atep Gypsum is also new in description, as far as E
know ; and from what has been said, such a thing could
hardly be expected. It is, however, necessary that any mi-
neral should be known, in whatever form or variety it may
be; and Gypsum being at present so much recommended
as a manure, makes it not less necessary, as otherwise Gyp-
sum might be brought to manure Gypsum, or be refused
by those who prepare it, as useless.
This is a pretty and delicate variety. The crystals are
much confused, but seem to be a mass of trapeziurns—see
tab. 67—piled or formed into little spires; the points of
the trapeziums being mostly inclining upwards. It came
from Derbyshire. The under specimen might be considered
as a red or rose-coloured Gypsum. They are often coloured
with red Oxide of Iron, in various degrees. This specimen
appears of rather an uncommon form; the crystals are
something like the above, but lie horizontally ; and it would
seem as if the whole was a sort of Stalagmite, having fallen
into this form in a particular state.
I received this specimen by favour of my kind friend
Dr. P. Murray, from the limestone quarry at Bilton in
Yorkshire, along with another very instructive one, part
of a larger mass, with a vein of whiter striated Gypsum ,
passing into it, holding almost orange-coloured, or deeper
tinged, perhaps, primitive rhombs within it—see the left
hand figure and right hand geometrical one. This varety is
sometimes compact and hard enough to be turned and
polished for ornaments.
wit — P Cee
Y; ei ene
5
t Sowaly Londo.
Oct 2B 07, Publish by Ta
69
TAB. CCXXXYV.
Fibrous Gypsum.
THIS variety is occasionally found near the others in
broad veins, if I may be allowed to call them so, looking
like veins on the side of the cliff when exposed, but very
broad, and varying in thickness and flatness. It is not fit
for carving figures, as its structure will readily show; but
for making plaister, for casting, stucco or manure, it is as
good as the others, and much attracts the attention of the
common observer by its regular and finely striated ap-
pearance. It is remarkable for the perfect straightness of
its fibres, which are sometimes four or five inches or more
in length, and always divisible even beyond our limits of
calculation, being an excellent example of a common fibre.
Lewenhoeck might have said of this as he said of the mus-
cular fibre, and he would have been nearer the truth—see page
40 of the second volume of this work. This variety of Gyp-
sum has something of the appearance of the Satiny Carbo-
nate of Lime: it, however, is not, like that, sufficiently
hard to take a polish, but a fresh fracture is equally bright,
whereas that has not so bright a natural fracture, and re-
quires polishing to add to its beauty *, The fibres are so
* Ihave truly stated where the satin-spar is found: Late authors have
very erroneously quoted Derbyshire for it, where, indeed, it has been sold.
70
compact in some parts as to give this stone a particularly
solid and glassy appearance, but in those parts they may
nevertheless be easily separated, even by the finger nail.
As Gypsum dissolves sparingly in water, the speci-
mens cannot be washed without great care, and brushing
scratches them; even the common air spoils their ap-
pearance, which is worth preserving: they should therefore
be kept very attentively.
Heit
1
Sah
7 Publchd ky Ja* Sow
Oct280
rat
TAB. CCXXXVI.
Wauen on the coast at Sidmouth, I had the gratification of
seeing the red marly sides of the cliffs or rocks beautifully,
to appearance, veined with red and white Gypsum, from
half an inch or less to a foot or more in thickness, for many
feet below the summit; and from what I have been informed
by my friend Mr. Murray, it should seem that it has much
the same appearance at the beautiful grove near Clifton
Hall in Nottinghamshire, the seat of Sir Jervas Clifton.
The Marle varying between these veins, which are often
very broad, is commonly called Red-rotten-stone-rock *,
and is sometimes intermixed with a greenish, more or less
indurated, Marle. The Red-rotten-stone-rock moulders on
exposure to the air, and often leaves the Gypsum projecting
in flattish shelves, which also sometimes moulder or fall
down, sooner or later, according to their purity or some
other circumstances.
The upper specimen, figured in this plate,is from Clifton +,
with the Marle above and below it. It is often very red, as
if stained with the Marle: the present is a greyish speci-
men, with the appearance of the Sulphate of Strontian found
in a rock of the same nature in the neighbourhood of
Bristol, where Gypsum is indeed sometimes found, but
may be easily distinguished from that heavy earth, by its
being so much softer and lighter. I chose this specimen
for the sake of comparison. This finely fibrous variety,
* The substance has nothing in common with the Rotten Stone used by
the lapidaries, tab. 240.
+ Ihave specimens from Forth River, near Belfast, by favour of Mr.
Drummond.
BOE.
and the coarsely striated one, may make several degrees to
the more compact or amorphous sort one way, or to the
crumbly or dusty the other way.—This latter is said to be
washed from the Gypsum in the rocks, and is called Gyp-
sum earth, but is a mere variety, and seldom occurs: in-
deed it would seem rather remarkable if it should remain
long in a dusty state, especially as at the Baths of St. Philip,
in Tuscany, the stream deposits the Gypsum as it passes,
so as to make casts. This is now so contrived as to de-
posit it with the greatest nicety into moulds of the neatest
workmanship, when generally the basso-relievo medals or
figures taken out, are as hard as those made from baked or
manufactured Plaister of Paris, as it is usually called.
Gypsum has been in use for ages as a manure, and is
now become very fashionable, large manufactories being
established for grinding, and patents taken out for the pre-
paration.
* Sowerby, London.
Octiz 1707. Fubtishd by Ja
73
TAB. CCXXXVII.
BARYTES § sulphata.
Sulphate of Barytes.
Class 2. Earths. | Order 1. Homogeneous.
Gen. 6. Barytes. Spec. 1, Sulphate.
Var. Crystallized.
——————— SST
Surrwate of Barytes from Surry seems not very generally
known: I was first informed of it by my kind friend Mr.
Warburton. It is perhaps rather remarkable for its bright
brown or candied sugar tint, and, I may also say, for its
being suspended in the midst of the Fuller’s Earth—see
descr. of tab. 231—in masses of about 100 pounds in
weight; the whole generally very irregular on the outside,
and more or less coated with Ochre, and incorporated with
the Fuller’s Earth, which is not so pure within two or three
feet of it, therefore the proprietors of the pits do not
desire to meet often with this Sulphate.
When these lumps are broken they are found to be a
mass of different-sized crystals, crossing and interrupting
each other continually, and sometimes distinct, of various
modifications. I was, it seems, particularly fortunate in
what I met with when I visited the place in 1805. I found
in two lumps most of the modifications from and with the
primitive, including two facets not yet mentioned by any
author. One part of the lump was particularly beautiful.
The annexed figure is taken from a fragment of it, and will
74
give an idea of the manner in which they lie. The darker
sides of the prisms with the Pyrites * are chiefly primitives.
The broader white + faces are truncations, as it were, of
these, and have little irregular cavities with somewhat stel-
lated Carbonate of Copper. On some sides there are minute,
bright, iridescently golden-tinged, rust-coloured rhombs of
Carbonate of Lime, which Count de Bournon took notice
of in my museum when admiring the specimen. There are
also darker ones passing to dark brown, and nearly or quite
black. Some very pale Amethystine Quartz is occasionally
found in the interstices, which sometimes has the im-
pression of the Barytes. ;
The faces in this specimen are best to be understood by
the geometrical figure. :
Since writing the above I have met with a specimen in
which an interrupted crystal about six inches long lies
partly imbedded in the gangue of the same, and ts of a
very fine strong bright vinegar colour, but so well relieved
as to appear equally bright; if not brighter, than the finest
jewel set on foil.
* The Pyrites, which is generally of a brassy yellow, was found from the
octaédron to the cubo-octaédron in much variety, elegantly embossing the
faces.
+ The opaque whiteness of the faces seems to be a crystallization with a
smaller propoftion of the water or solvent.
Oct.27807.Lublichd by Jal Sowerby, Love
<2
75
TAB. CCXXXVIIL
BARYTES sulphata.
Sulphate of Barytes.
Class 2. Earths. Order 1. Homogeneous.
Gen. 6. Barytes. | Spec. 1. Sulphate.
Div. 1. Crystallized.
SSE
Wuen any thing unusual comes under our investigation,
it is a pleasant task to account for it if we can. Subjects
of the present nature may not be uncommon, therefore it
is the more convenient to comprehend them. The speci-
men here represented is particularly interesting and in-
structive, as the forms are strikingly curious, and show
the tendency of the molecules to form according to the
laws of Crystallography, notwithstanding certain interrup-
tions. In this instance the gravity of a quantity of Sulphate
of Barytes in solution has seemingly caused it to settle in
contact with a loose powder, consequently having more air
in its interstices, which, as the Barytes subsided, has risen
into the substance, and, in part, interrupted the mass,
while at the same time it gives them particular forms and a
curious appearance ; some of the powder filling them up more
or less towards their bases, which are sometimes quadran-
gular, but mostly hexangular—see the right hand figure—
where it appears that the greatest part of the hollows and
the larger sides of their bases are diagonal to the primitive
_ fracture. The variety in the forms of the hollows are in-
76
numerable; and there are some hair-like appearances on
the tops of some of them, which are bending or otherwise
modified: in the point of one is a little black speck like
soot. The specimen has broken rather conchoidally, but
not far from the primitive fracture. The somewhat zigzag
line is interruptedly six-sided, depending on the particular
interruption of the primitive molecules, and is chiefly filled
with the same powder as the others; whence its opacity.
It is not much unlike in the angles to che bottom figure of
tab. 72, and is remarkable for its contrary and prostrate ap-
pearance; and the combination of the two might lead the
imagination very far, of any one who had not attended to
Crystallography. I mentioned in the description of tah. 71
the water or liquid in the little hollows of this substance.
I add an outline or sketch of them at the bottom of this
plate, as hitherto they appear to be a great curiosity. The
hollows are rather irregular, a little angular, and have
sometimes more or less tendency to the form of crystalli-
zation. The air bubbles of course upwards, in whatever
position they are held; but in the long one it only moves
the space marked with dots.
I have specimens of solid crystals of Sulphate of Barytes
covered with, and passing into one another; and so it
happens with different substances; but these I thought
sufficiently remarkable to illustrate the present pheno-
menon, which may be very useful. . Both these specimens
serve to show the double refraction completely through the
columnar sides. Thus the bubbles and hollows are seen
double as in the bottom specimen—see the magnified figure.
And where we can look into the upper specimen, the py-
ramids and odd forms may be seen double.
These specimens are from near Alstone Moor, Cumber-
land, and are in the possession of Walker, Esq. I have
specimens with Copper Pyrites in spicule, hair-formed, &c.,
in them.
Ne inne
AWionyony
951.1807. Lubtisha bv Ja’ Sowerby Londen .
TAB. CCXXXIX.
BARYTES carbonata.
Globular Carbonate of Barytes.
Class 2. Earths. Order 1. Homogeneous.
Gen.6. Barytes. | Spec. 2. Carbonate.
Div. 2. Imitative.
ee EEE eee
SuLPHATE OF BARYTES has been represented in tab. 96 of
a globular form, and I believe it was thought almost a di-
stinguishing character of the substance. Since Carbonate
of Barytes has occurred in globular forms also, it becomes
necessary to show the distinction, as we do not know that
it has been before observed by any author. According to
a specimen I have received from Dufton in Westmorland,
which is rather a wedge-shaped fragment—see the back
Sigure—they may be tolerably large, as this fragment, which
seems to have been part of a ball, being near six inches long,
promises some of a larger formation, and I have seen some
balls pretty perfect, from one to three or four inches in
diameter. An opaque roughness generally occurs on these
nodules, which sometimes show a tendency to crystallize
in six-sided prisms, either with or without six-sided pyra-
mids*, or only with part of a six-sided pyramid, the end
being truncated—see the top large specimen and part of the
smaller, I <.o not show the most distinct, as in those, they
* Such as tal. 109, being, however, very rare.
138
are easily distinguished. The fractured parts have some-
thing of a columnar radiation; but very indistinctly and
massively incorporated, and the fracture is otherwise small
or largish, irregularly splintery, without any sign of in-
ternal crystallizational fracture. This is so peculiar to
Carbonate of Barytes, that it was chiefly known from other
substances by this mark, before it was found formed in ex-
ternal crystals, although that had not been particularly
described. I have a large piece of radiating Carbonate of
Lime from my kind friend F. Hall, Esq., of Arkendale,
fourteen inches long, on the face of which the appearance so
far corresponds with Carbonate of Barytes, that many good
mineralogists have doubted which it really is; but the
fracture of Carbonate of Lime soon exposes it. Carbonate
of Barytes, or Witherite, may thus be in part known by its
fracture. I have had dark specimens with Pyrites in it so
coloured by the Iron, that, for want of the above observa-
tion, they would not have been known from Carbonate of
Lime.
Oct11607 Piablichd bu Jai Sowely, Londen,
19
TAB. CCXL.
Rotten Stone.
Ix Derbyshire, about two miles west of Bakewell, is found
some variety of this remarkable substance in land belonging
to the Duke of Rutland. It is said to be found also in
Shropshire and Somersetshire, and I have a seemingly
chance specimen from Sussex, by favour of Mr. Borrer,
Near Bakewell it is found in broken nodules or fragments
in the upper soil to about eighteen inches deep or more.
It should appear that some parts of the rocks in the neigh-
bourhood are in a state suited to a certain decomposition,
by exposure on the common surface, mouldering in a pe-
culiar manner into a more or Jess coherent, fine, dusty,
soft, but somewhat granular appearance. The rock varies
from a light brown to a deeper and grey or blackish hue.
In decomposition it becomes lighter, and passes from dark
to light yellowish brown, in which state it 1s commonly
called Rotten Stone. It is sold to be used in manufactories
for polishing metals,.&c.; but.is more particularly ne-
cessary to the lapidaries*, who polish the harder stones
with it, by the help of water, and the substance of their
machine being of a harder or softer metal according to the
nature of the stone, as Lead, Copper, &c. Nature in this,
as is always invariably the case, has furnished us with a
substance so nicely suited to this particular purpose, that it
* Lapidaries sometimes cut and polish the more curious glass, imitative
of precious stones (commonly called paste) ; but this is considered as rather
degrading to the profession, and it might seem degrading to the glass po-
lishers to teach them to polish glass. Rotten Stone is certainly so hard in its
nature, as rather to grind the glass, as they would call it. Putty is used for
polishing glass. It is an Oxide of Tin.
6
380
is an error in any author to place it indiscriminately with
Tripoli; at least with that from Tripoli, which is sold in
the shops for polishing (chiefly metals) ; and being now
rare, they recommend Rotten Stone and Crocus Martis*,
&c., for those purposes; although neither the Tripoli nor
the Crocus Martis would at all suit the true lapidary.
The upper specimen is part of an irregular flattish frag-
ment of a lightish colour, begining to decompose. The
middle figure is part of a nodule decomposing on the out-
side: the curved line in the middle is part of a petrified
shell, which is composed of Carbonate of Lime. The
darker part is hard, looking like black Limestone (and
much resembles the black Calp of the Irish, having also a
similar foetid odour, quite offensive when scraped) ; but that
is of a texture more durable, else it would not be used for
tombstones and paving.
The lower specimen is probably altogether Rotten Stone,
or wholly decomposed rock, although it cannot be posi-
tively known by outward aspect, as even the best lapidaries
have experienced.
Mr. Richard Phillips has analysed the Rotten Stone, and
kindly favoured us with the result, as under;
‘Alomine: 6) 600 bo aeeoesb
Silicared. . £5) dee
Carbonaceous matter’. 10
Tripoli is said to contain
SUDA. 4) ag OD
miumine ':. « - owe
QOxideoflron .. 2° 3
although the Alumine and Iron are in general in greater
proportion.
* A rust of Iron, now often called Tripoli; rendering the true Tripoli
more obscure.
Dec.11h07.Publishd ty Jax sovain, Londo.
81
TAB. CCXLI.
SILEX ett eua.
Crystallized Quartz.
Class 2. Earths. Order'1. Homogeneous.
Gen. Silex. Spec. 1. Quartz.
Div. 1. Crystallized.
Tus curious specimen was collected long since by our
late worthy friend Mr. W. Day, in Derbyshire; and as we
have not seen the like elsewhere, we consider it as a va-
luable specimen. It is not uncommon to see Quartz on
Galena; but when it occurs in eighteen-sided crystals fairly
terminated at both ends, the prism elongated, and mostly
perpendicular upon all the faces of the Galzena, whether the
Galena be cubical or octaédral, it is very remarkable. In-
deed the Quartz in general appearance resembles small seed
or grains, which, when perfectly well crystallized, are not
common. They are sometimes dispersed, though adhering
in bundles to each other, as figured at the bottom of the
plate, and occasionally terminated by three-sided summits.
VOL. III. G
A Pgh
OG teat Bee pe Bye)
SS aeberadtta sys
ie oh eae
~
i
j f
ie
auwhhey
esa
Dec.1280; Publish ky Ja* Sowerby London.
—_—— a
83
TAB. CCXLIT.
Peruaps this is one of the most remarkable crvstallizations
ever observed in Quartz. As the ends of the primitive
rhomhs—see tal. 41—are so scarce, this specimen is the
more curious, having them dispersed about it. It is parti-
cularly so, for their being as it were nearly mackled, or in
pairs, making a bifid-ended crystal, which is partly a
series of these depositions, undulating in a somewhat step-
like manner, as if formed on each other, sometimes with
scarcely any prismatic sides, except at the lower ridge of
the opposite rhombs. Sometimes they are nearly trifid—
see figures 1,2 and 3. Besides these there is a very odd
formation in two places, much resembling the semicircular
ends of bivalve shells, partly gaping, like the fruit of some
_ Banksie, for instance of Banksia conchifera of Geertner.
These have smaller crystals on their outside, like the others 5
they are rather concave within, and a little convex without.
This specimen was sent me by my kind friend John Stack-
house, Esq., among others favours, from Cornwall. The
whole specimen is Quartz, a little coloured by Oxide of Iron,
although at the back in some parts it is darker, and there
are one or two crystals of a red tint with triedral ends,
which correspond with the characters of the Eizen-kiesel of
the Germans—see tab.219. This odd mackled formation
of Quartz it was the more necessary to figure, as the
rhomb referred to was scarcely known, and much less so
deceiving a crystal as this, if I may so call it, which has
but little of the usual appearance of Quartz.
G 2
tescabiest ey ay pail
. fining. 08 ee | s
ii bs to “2 {24 hPa
oC a adie oes ght glLMli OO aatiaaae. 3F siuonga smi: oe
| yale tammy e ak i crutethaes a came ) i ue}
we VUES 208 Saf. DAT
aan ow Wphieto, Gerace! A
Pettee Se | pipeoth st as achkax
yates oF aaah xe waka § oa al
aagen sit hit AIRS be “print ,
_ OR ARK 9th wom MO gE- to ui a ee
‘ ; Nh SON PRE RENG 28 gga:
ond rite botige, a shobae Y exo ae
248
Dec.2.1807.Fublishd by Ja? Sowerly Lond .
95
TAR COMLVITT
QUARTZUM argillo-pyritaceum.
Pyritaceous or Alum Clay.
Ciass 2. Earths. | Order 2. Mixed.
Gen. 2. Farinaceous Quartz. Spec. Mixed with Argilla and
Sulphuret of Iron.
Syn. Pyrito-bituminous Aluminous Ore. Kirw. 2. 17.
Argillaceous Schistus. Bal. 62.*
Alum Slate. Jameson, 1. 323.
Tue Alum Clays vary much at the different places where
they are found, and may be divided into many tolerably ‘
distinct varieties, from the appearance of common black
Clay to a more slaty one, more or less indurated. They
do not adhere to the tongue, nor take a ‘polish readily by
being rubbed with the finger nail, but rather a crumbly
whitish streak. Aluminous Clay is sometimes glossy with
a slaty fracture, but otherwise very dull, except having
some glistening particles of Pyrites.
Some sorts effloresce readily in the common air—see
tab. 23 and 24—-and some become covered with a whitish
tasteless powder. The mixture, like other Clays, may
contain many adventitious substances, particularly veyetable
and animal. At Whitby*, Bolton and Stowbrow works,
in Yorkshire, vegetable impressions, the remains of wood
and various shells, are found in the Clay. I have very curious
specimens of the different changes of vegetables, from
Whitby, in petrifactions from bituminous coaly formations
to the finest plank jet, if I may so term’it, and some curious
shelly remains, of which last sort are the Cornua ammonis
—see tal. 30—which are commonly called Snake-stones ;
and to favour the idea, the people who gather them form
one end into a kind of head.
Among the remains of shells, some there are almost all
Pyrites ; as the specimen now figured, from Whitby, being
the remains of a large Pecten or Ostrea, is formed with
= Cae specimen from Whitby appears from its colour to have been
roasted.
96
- two or three coats of Pyrites. I have therefore exhibited it
for its novelty, as it will very well show the nature of the
Clay at the same time. As I found a species of Arca, new
to me, I adda figure, as I believe they are not uncommon
there, though not, to my knowledge, elsewhere; therefore
they may identify something of the geology of the spot, as
well as add to our information in this department.
It somewhat depends on the nature of the ore to vary the
means of obtaining the Alum from it. It is mostly burnt
and well watered, and to the water, when saturated, is
added Muriate of Potash, or some other Salt, sometimes
an Ammioniacal Salt; it is then left to crystallize, which
the Alum usually does in masses terminated by four-sided
pyramids. In the last act of crystallization it forms the
other half of the octaédron more or less perfectly with
truncations, and sometimes crystals so piled on each other,
side ‘by side, that the workmen call them Alum towers,
making handsome ornaments under a glass; but these
should not be exposed to the sun, nor to much warmth, as
they will then lose their beautiful transparency.
The Alum stone of Tolfa* in Italy is found to contain
By Klaproth, By Vauquelin.
Silica neigh: veal sp BOO hier etetd eee
SAINT es) ninabe'g (AAO! emis cue k goptee eae
Potashiiee va Gert» AOD te ely oie) eens
Sulphuric Acid... 16°35 |e. ay (25D
W ater os) bliss aie y SU; On es epeeee Ree
162°0 ~ ¥00:00
ee
The Roman Alum is sometimes found in small crystals
of a reddish cast, and is well known in shops. The nature
of the British Alum might infer its containing some Am-
-monia, otherwise it differs only a little in the proportions,
and in containing a slight foreign mixture, as it is little
else than Clay and Pyrites. Sometimes particles of Mica
are found in it.
Clays, which seem too common almost to claim atten-
ticv, whether mixed with the spoils of the most precious
rocks, plants, or animals, or with more humble materials,
are still enriched to serye some future purpose ; and according
to Shakespeare, at the worst, it may, like the noble dust of
Alexauder, still serve to close a bunghole, or, like ‘* Im-
perial Cesar, dead and turn’d to Clay, might stop a hole
to keep the wind away.”
* This, as may be inferred from the analysis, requires no addition of
Alkali to make it crystallize. It seems very different from the British,
Fh ¥ 1.1808, Tubiishd bur Ja* Jowety, Lendaw -
249
OT
TAB. CCXLIX.
ZINCUM Oxy-sulphureum.
Oxy-sulphuret of Zine.
Class 3. Metals. | Order 1. Homogeneous.
Gen. 6. Zinc. Spec. 3. Sulphurated Oxide.
Div. 2. Imitative, mammillated.
Syn. Blende. Dr. Kidd in Nicholson's Journal,
v.14. 134.
Weare glad to give a figure of a new substance to the
‘mineralogical world, by favour of Richard Phillips, Esq.,
especially as it has been analysed by Dr. Kidd. Its first
appearance gave rise fo many queries; for the workmen
who found it considered it as wood-tin, but its resemblance
to some of the blistered Copper Ore from Cook’s Kitchen,
&c. excited different ideas. Dr. J. Kidd shows it to be
an Oxide of Zinc with a largish proportion of Sulphur. I
believe only one variety has been found, and this has always
in some degree a bubbled appearance; the bubbles more
or less solid, with a variety of tints, from dark dull yel-
lowish brown to nearly white, and rather irregularly coated.
The fracture is rather conchoidal, not striated, with a
waxy appearance. Externally this mineral is light yellowish,
often smoky or dusky grey, sometimes with a bloom like
a plum, or varying to a dull crimson, occasionally some-
what iridescent.
The specimen figured is on a matrix of Arsenical Iron and
Quartz.
VOL. III. H
98
The analysis by Dr. Kidd gave
Oxide of Zinc . 66
Sulphure atm 3S
This gentleman also found a Platinum crucible rendered
fusible by it ; we suppose, in consequence of the great
quantity of Sulphur which it contains.
Huel-Unity and one or two other mines in Cornwall
have lately produced this substance.
The Oxide of Zinc, tab. 202, lower figure, is somewhat
like the above; but we do not suspect it of containing any
notable proportion of Sulphur, if any.
y
i
with
abe
2A be lat Soveday, London,
99
TABS CCE.
SILEX quartzum.
Diy. 2. Imitative.
Turs might be called a Jasperine or Porcelain Flint, and
is extremely curious, as having taken place of a shell much
resembling Venus Islandica, and seems merely to differ in
being deeper. This appearance is rarely found, especially in
the place, as it were, of the shells themselves.
The top figure shows fragments of an Escallop, looking
like recent ones, but are of a most compact Silex, semi-
transparent like the natural shell.
The lower figure shows a transverse piece, separated at
the crack, with somewhat dendritical veins, giving the ap-
pearance of China. It has also the cast of other shells that
were involved in the same catastrophe. The Rev. Dr. Becke
was so good as to favour us with this curious specimen,
which was found at Little Teignmouth in Devonshire ; and
the Rey. Dr. Sutton has favoured me with a shell, probably
of the same species, from Elmsett in Suffolk, but little
changed, being nearly like such as may be found exposed,
and dead, on the coast. It has some fragments of Sertu-
laria with Lime and Gravel about it. I have some of the
same, which I found at Sydenham when the canal was
digging there in the year 1805, in a marly Septarium. So
we may trace the same shell at very different places; which
will not only be a help in geology, but will show at one
view the varieties to which Flint is liable, and not only
that it may be capable of taking casts or impressions, but
be in different states during that operation. In this instance
it seems to have been considerably diluted, as the dendrites.
(if I may so call the red lines) are much attenuated.
H 2
ioral nang ate “ vals
ile adie goes ile
*
vi : One
3 ae Ce os Linh di
bi Wg ori sahil ‘asian
a
gitn a i
i
\
e é fin :
Wi Ae Siti pe fects 1 paltaleadiele
apie odt en. borglb vider tty iehon nap dred
LarsoR IS down St6 (eoail: bs oc Hn
Feb. iabo8. Publis by Jat. Somerby Londen ,
101
TAB. CCLI.
LITHOMARGA.
_ Class 2. Earths. Order 2. Mixed.
Syn. Lithomarga. ysis +, «kg, eee
100'0 * 100
* I understand this dust is occasionally adulterated with micaceous Irom
—see tal. 64—which is apt to rust, to the great disappointment of the care-
ful housewife, who considers it as the property of the Black-Lead to pre-
vent the Iron from rusting.
Stay
135
TAB. CCLXVIII.
Plumbago in the Rock.
Tus substance is found in the form of pebbles in rocks,
making Pudding-Stones, Amygdaloids, anda sort of Traps,
and seems to have been but little understood by mineralo-
gical writers.
The rock is seldem schistose or slaty. It is sometimes
veined with red Carbonate of Lime; sometimes it consists
of a grayish or greenish compact steatitic or magnesian mix-
ture, including the Plumbago, very intimately mixed, or
in powdery-looking particles, minute pebbles, and other
forms, some resembling fragments, in common with par-
ticles of yellow Pyrites, pebbles of Quartz, &c., tightly or
loosely included *.
The upper figure represents an amorphous spotted mass
with the Plumbago, Pyrites, and Quartz pebbles.
The lower figure has much the resemblance of common
dark Limestone, and is much impregnated with Plumbago,
a small mass of which lies on the surface.
I have a specimen of somewhat largely foliated Plumbago
holding small cubic ‘yellow Pyrites, varying from a bright
colour to different states of decomposition, but not passing
towards Plumbago. I have some Plumbago in a stratified
piece of Quartz, coloured by red Oxide of Iron: euuerd
the rock it is found in varies much.
* Some substance, probably Quartz, runs occasionally among it, re-
sembling Actynolite, being in longish strix. My friend Mr. Sheffield, in his
curious collection, has a piece of this, and I was favoured with a specimen
by the kindness of Mr. Squire.
‘
eae ihre
‘
a
wt)
Fune22808 Pub tisha 1
by, London,
137
TAB. CCLXIX.
Prismatic Plumbago.
For this fine specimen we are obliged to the favour of
G. B. Greenough, Esq., M.P. P.G.S., who had it from
near Crumnock in Ayrshire. The shape and approach to-
wards crystallization, if it may be so called, somewhat ac-
cords with some of the columnar stones*, of which the
late Mr. Watt has with much philosophy given a valuable
paper in the Philosophical Transactions for 1804. The for-
mation of Basalt differs much from this, in which we have
to account for the transverse joints or articulations, which
do not so plainly appear in this; although there are some
indications of separation in some parts, yet I would rather
compare it to the separation usual to crystals of coals. —See
Crystallography and British Mineralogy, tab. 48. The
same form nearly remains even in the cinder of the common.
coal, if slowly burnt ; so this resemblance may depend upon
similar laws, having the same original atom or nucleus, if I
_ may so call it.
This extraordinary substance is as yet new in this form
to the mineralogical world, nor do we know of it as any
other than a British production.
The specimen before us shows the probable varieties of
this formation, from straight to curved, and are somewhat
varied in the angles and number of them, in which it much
resembles various Coals when partly burnt in a slow fire,
* A peculiar stone found in columnar forms, reaching many miles, at the
Giant’s Causeway in Ireland and at many other places, of which more will
be said hereafter;
138
which crack or divide into irregular columnar appearances,
although larger and more expanded, somewhat agreeing also
with the mineral coke—see tab. 192 :—but as. they are also
more compact, it may depend upon the substances around
them preventing in a great measure their expansion, which
would agree in some measure with the experiments made by
the ingenious Sir James Hall.
A long time since I received a portion of columnar
Glance Coal from a Dyke about ten miles from Wanlock-
Head, by favour of G. Laing, Esq., which so nearly re-
sembles this in structure and appearance, that thence we
might suppese them the same thing; and Mr. Greenough
has specimens which are more intermediate, some parts
having Plumbago about them.
Junes.1808 Publishit bia Jes
Je
verlgy London
IO
139
TAC (CORN
PLUMBUM sulphatum.
Class 3. Metals. Order 1. Homogeneous.
Div. 3. Amorphous.
EEE
Tus curious, apparently new, decomposition of Galena
is so remarkable in its property of burning with a blue flame,
like Sulphur, that it seems a prodigy, and has from that
circumstance been called inflammable Lead Ore.
The upper figure shows some remains of the cubic forms
of the Galena, the outside having been so affected as to
have blunted and in some parts obliterated the angles.
The lower specimen is more compact, and is striated with
more or less zigzag lines, and has a few blotches of Galena
about it. The outside is generally whitish with a granular
texture passing to crystallization. Inwardly it is generally
somewhat darker and often of a dense gray, with a horny ap-
pearance and flinty fracture. It shines upon being slightly
rubbed with the finger nail, and may be easily scraped.
As this substance is scarcely known, of course there is
no analysis recorded. Having examined it by the blowpipe,
we annex a short account of the changes it underwent. A
piece being laid on Charcoal, and the flame gently applied
by the blowpipe, it became red-hot, the Sulphur sublimed
from the interior and melted with a greasy aspect, and a
trifling blue flame, leaving the substance rather lighter in
colour when cold. On further urging the flame, white
Sulphate of Lead appeared on the surface which bubbled
and blistered, and on cooling showed some signs of facets
and spicule. After a while it was reduced to a globule of
Lead. On further examination we find it to be composed
of Sulphate of Lead, and about 10 per cent. of Sulphur.
A
=
ie oNar ber i spot Lena: }
dots: i of Coon cay is ohelin MARRS
jatoo A ot hae ay GET
bra
4
NEE 26 A894
“141
TAB. CCLXXI.
PLUMBU M_ sulphureum.
Sulphuret of Lead, or Galena.
Div. 1. Crystallized.
ee
‘Tue Galena, or Sulphuret of Lead, is remarkably striking
in this figure, not only because it is eight times repeated in
stripes, but the coincidence of the opposite halves is pecu-
liar; the outer stripes are nearly of the same width, and the
next within them double, and those again nearer the middle
are single, and nearly the same width, so that the whole -
together form eight lines in pairs. The substance in the
middle of the specimen is Sulphate of Barytes, and ‘the
substance between the lines of Sulphuret of Lead is Car-
bonate of Lime; there is some Sulphate of Barytes on the
outer sides. }
The specimen came from Derbyshire. I know not in
what position it was found, whether lying horizontally, per-
pendicularly, or obliquely; it, however, has been admired
as a remarkable stratification by some, and as an example
of a vein by others, instancing what Dr. Thomson says of
a vein according to Werner, where it is- understood as
characteristic of a vein to have opposite sides alike, with
ihe same or different substances often repeated. The lower
pair of double stripes differ from the upper in this specimen,
by haying a more regular and equally bounded zigzag line
between them.
The lower figure is Sulphate of Strontian from Bristol,
bounded by Sulphuret of Lead,
142
We do not know that this has been before noticed, and
it is very rare at present. The modification of the Stron-
tian indicates a centre, and the crystallizations seem to
meet in the middle somewhat in points ; but whether this:
lined a cavity on the inside of a fissure or vein I know not,
nor does it often happen that the workmen are very parti-
cular in this respect ; but metals of some kinds may be said
to indicate veins or lodes, which are nearly the same
thing.
iene
Li ee ih
i a a ae
Ra
Ne
Phil V4
Pea cea
ine
ie
Lb2
tum,
werly Lon
Jiore 1.2808. Piblish Thy Jarek
143
TAB. CCLXXIL
SILEX talcum.
Earthy Tale. Green Earth of Veraw.
Terre verte.
Class 2. Earths. Order 1. Homogeneous.
Gen. Silex. Spec. Talcum,
Div. 3. Amorphous,
Syn. Green Earth. Kirw. 1. 196.
Sar to be found near Verona, a3 well as in Bohemia, &c.
also in Scotland, and Somersetshire. The present specimen
came from the Hill of Kinnoul in Scotland. It is the largest
piece I have ever seen, and was lent me by G. B. Green-
ough, Esq. It is to be found entrapped in a smoothish
earthy rock in various forms and of different sizes. I
know not if it could be gathered so pure as to serve for
commerce there or any where else in Great Britain ; but if
it could, I should think it might be chosen of such tints as
might be desirable to artists, it being very durable. It may
probably be the pigment used in the large draperies often
exhibited in pictures of the Venetian school, so much ad-
mired by connoisseurs for their brilliant and lasting greens.
Mr. Kirwan thought the green colour was owing to a
mixture of “ Calx of Nickel.” It is not, however, known
at present what gives permanent colour to most mineral
substances. Iron in this seems to be particularly oxidated,
so as to serve that purpose, perhaps with the help of a pe-
culiar phosphate of a blue colour, mixed with a certain
144
yellow Oxide, or Sulphur, these being so nicely incorpo- _
rated in the mass as not to be easily detected. Most en-
deaveurs to ascertain the colours of substances first discolour
‘them, and it is not easy to find and mix the proportions
by synthesis, although the present advancing state of
chemical knowledge gives a hope that these things are
likely to. be discovered in due time.
The analysis by Klaproth shows no particular colouring
substance except Iron, as will be seen below;
Silicaya ss veiw) 2 3S ;
PUNE vane eth
Mapnestan ss sot stoae
UNC need ol hel ee ao
Oxidemilronyiis" > ax
Winterreise coe e marlin
Loss’ 4-.6)-s-cageoes 1
100°0
The holes in the Rock of Kinnoul are occasionally lined
or filled with great variety of coloured substances, perhaps
including all possible mixtures, except the more brilliant
reds and crimsons,
Wap Near eet
Aug 22508. Publish by Jat Sowerlky London,
145
TAB. CCLXXIII.
BITUMEN succinum.
Amber.
Class 1. Combustibles. Order 2. Compound.
Div. 1. Amorphous.
Spec. Cuar. Bitumen in combination with Succinic
Acid.
Syn. Succinum electricum. Bernsten. Jinn. ed. 13.
t., 3. pp. 108.
Succinum durius, Europeeum; Succinum. Wal-
ler. 2. 108.
Karabe, Carabe, Succinum, Electrum, Glessum ;
Ambra citrina, Sacal. Lemery Diction. 463.
Succin. De Lisle, 2. 589.
Succin, Ambre jaune ; Karabé. De Born. 2. 88.
Bernstein. Emmerl. 2. 81.
Petrole combiné avec I’Huile de Succin. Sciagr.
2. 22.
Ambre jaune. Daub. 30.
Amber. Kirw. 2. 65.
Succin. Hauy, 3. 327.
Peruaps, for an anciently-known substance, Amber is as
little understood as many more modern substances. Some
consider it as a mineral oil with oxygen, or, as Mr. Par-
kinson, an inspissated mineral oil. By others it has been
thought either honey or wax indurated, though mostly
judged to be an indurated vegetable gum or resin; and
Mr. Patrin, among his arguments for its being honey,
VOL. III, 'L
146
supposes gums or resins could not entrap insects, which
Amber is often understood to do, and even fishes.
The resin called Gum Aniine by the apothecaries and
varnish-makers, is often used to make varnish, which very
nearly resembles amber varnish, as the resin itself does
Amber. Pieces of this frequently contain many ants and
other insects, as well asthe Gum Copal. TI have seen a
fish enclosed in Amber, bought at the high price of five
guineas *, and have heard of another at the same price,
which, when examined, was found to have had:the fish
enclosed betwixt two concave pieces; the said fish being a
badly dried stickleback, a very common inhabitant of our
own pools and ditches. “Tt is very seldom, if ever, we see
perfect Amber with insects, as it either has a deceptive
appearance, or what was supposed to be Amber proves
either Copal or Gum Anime.
I find by my specimens of true Amber that it is subject
to much variation, even in that character which has been
deemed its principal criterion, viz. its odour, as some of
the amber-workers, who seem to know it pretty well, find
it occasionally very disagreeable. This causes much contra-
diction among collectors.
The best characters I can find for Amber at present are,
that it occurs in irregularly rounded forms with a roughish
coat, rendered dull with small semicircular flaws, varying
from very bright transparent yellowish red to opaque white.
When broken it has a waxy, or resinous, and rather horny
appearance ; mostly having a conchoidal surface, and often
sharp edges. It is resinously electric, and, on being
briskly rubbed, gives out sparks visible in the dark. It
takes a good polish easily, and retains it better than most
resins, with a far superior degree of richness. It is rather
colder, and I can fancy it allows the finger to slide more
readily over it; it is also rather tougher than the hardest
resin.
* Not a high price, if no deception.
+ All the resinous substances are nearly alike electric by rubbing, which
is often considered as a characteristic mark of Amber.
147
The acid obtained from Amber, called Succinic, is pe-
culiar to it, the origin of this name being obvious.
_ Amber is said by Woodward to be found in the clayey
or aluminous rock, and on the shore, at Whitby, in three
states or varieties. He names the three varieties, Rock,
Washed, and Fat Amber. It is found in many of the
northern parts of Europe as well as in Great Britain, in
which it occurs on the Norfolk and Suffolk coasts, chiefly
at Lowestoft, sometimes in great variety. Some authors
speak of two varieties, white and yellow, but the white is
generally described as of a light or straw yellow.
Some parts of the upper figure are so perfectly white that
it will not allow of any other denomination: it is opaque,
and forms a great contrast to the yellow or redder parts,
which are transparent.
The lower figure is taken from a specimen with which I
was favoured by Dr. J. E. Smith. It is such as is com-
monly called Fat Amber, and does not unaptly resemble
some sorts of fat, having a mixt and clouded appearance.
Some pieces more nearly resemble Mineral Tallow, such
as is found in Ireland, by some considered as butter pre-
served in the bogs of that country.
I have specimens of this, and mention it here, as suffi-
client, not at present considering it as a truly mineralogical
substance, although mentioned by the excellent Kirwan.
It is certainly the spermaceti-like remains of some animal.
I have also the kernel of a common nut of a whitish fat or
greasy appearance, exactly resembling the Mineral Tallow.
It was found in the Thames with its shell entire.
Amber is much esteemed when large, and free from flaws,
specks or blotches, either for curiosity or for ornamental
purposes, and sells for a proportionate price. It is supposed
to have preceded the use of ornamental jewels ; which seems
very natural, as the ruder people would manage it better
than hard stones. Accordingly we find in the tumuli * of
* These, according to the observations of my friend, the experienced
Mr. Cunnington, are the most antient Tumuli; and although they somes
ju
148
the primtive Britons that they made their beads and other
ornaments chiefly of Amber or of Jet, with a few rude glass
beads, and some ivory; but we do not know that any gems
have been noticed among them.
times have ivory, gold and copper, these articles seem distinctly to have be-
longed to a more polished people by the neatness of their workmanship,
and were possibly taken in barter from the Gauls or Pheenicians. ‘The
Amber they made use of is mostly cf a dark and very red colour, perhaps
from having been long immured in such a situation, being also much cracked,
like Amber that has been long exposed. Plates of two inches long by
one inch anda half wide have been sometimes found. Amber is sent to the
East Indies by the merchants, where it is much valued for its beauty, and its
supposed quakties as a charm.
Aug 1.2808. Pbrishd ty Ja! Sowerby London»
149
TAB, ,CCLXXLY.
Aruoucen much has been said about insects, leaves, bits
of plants, gold, silver, and iron* being found in Amber,
I do not know of Pyrites having being positively noticed.
T have some with Pyrites in it in small globules, and one
specimen with the decomposed remains of wire-like Pyrites ©
in long diverging tubes. The latter I figure while there yet
remains this vestige of the Pyrites. It was observed when in
the dealer’s hands ; but as he did not know how to value it,
although J told him the Pyrites was decomposing, I did not
obtain it until it was nearly decomposed, notwithstanding
its being of no value but as a specimen, from its foul and
- unbrilliant aspect.
The upper figure shows a piece with the striz or tubes
more or less filled with Sulphur and decomposing Pyrites.
The lower figure exhibits another piece with small knobs
or little round specks of Pyrites, some decomposing and
showing the Sulphur and empty holes, ©
The left hand figure much resembles Gum Anime in the
common outward aspect, except that it appears to take a
more perfect polish. It, however, has all the characters
of Amber, and encloses about the middle an insect of the
Hymenopterous Class, probably of the Genus Sphex; but —
it seems a species not known at present. I prize this more
than ordinary, as I have good reason to suppose it came
from the Lowestoft coast. It contains also some drops of
liquid, which I suppose have not been before observed in
Amber—See the lower corner towards the right hand.
The specimen is full of flaws and cracks, and holds
* In the Encyclopxdia Britannica it is questioned whether this gold or
silver may not be Marcasite, and the Iron is mentioned as being sometimes
in the state of Vitriol. The glistening appearance of the flaws may often
mislead. ;
150
much of a dirty-looking substance, rather of a carbona-
ceous appearance.
I have not seen British Amber so large, and free from
what is commonly called foul, or cracks, as the foreign ;
but the present specimens pretty well include all the usual
colours of Amber. All the fine and clear specimens that
fa]l into the hands of the dealers are sure to be deprived of
their coat, as this has been, or to be cut into some fanciful
form so as to make them more saleable.
Amber is sometimes of considerable size. I have seen a
fragment measuring fourteen inches and a half in girth
Jengthwise, by seven inches and a half in girth the shortest
way. It weighed nine ounces and a quarter. Itis how-
ever said that there was in the possession of the Grand
Duke of Tuscany a column of Amber of ten feet in height.
It is said to have been well known to the Arabians, who
called it Ambra, and to the Greeks, who called it *HAexrgov*.
* Some may be led to suppose from reading in Ezekiel i. 4, and 27, and
will. 2, “as the colour of Amber,” that this substance was known to the
Hebrews in the time of the Prophet; but on further investigation it will ap-
pear hardly safe to found such an opinion upon the received English Version.
Junius and Tremellius render the passage “ tanguam color vividissimus :” and
Dr. John Taylor in his Hebrew Concordance has S5nwn, which occurs only
in the above-cited three passages, pruna ignita. The LXX have as dgucw
gaéxroe, and the Vulgate “ quasi species electri ;” but Zaexrgay, electrum, here
doubtless signifies, as it often does, an alloy of gold and silver, and not Amber.
And the account given in the Synopsis Criticorum of the word bown,
chasmal, is probably right. It is supposed that Ezekiel borrowed the word
from the Chaldee, in which diaiect it signified a brilliant alloy, mixed not of
gold and silver, but of gold and brass, being the yaaxoyedoiv, OF xaAxds
xeveoudas of Diodorus, and that it is composed of the Chaldee words Wm3,
nachas, lrass (the 3 being dropt as in other analogous instances), and bbn,
dn, malal, gold. Some commentators, desirous of extracting all the
meaning they can out of a word, have maintained that the Prophet selected
this substance, as expressive of the union of the divine and human nature
in Christ.
Amber having been first found on the shores of the Baltic, Skinner is of
opinion that the Arabs were indebted for their name Ambra or Antar, as
well as for the substance itself, to the Teutonic nations. In Dutch 4eil-
bern is to burn up, and %Aen-bern-steen, lapis ustilis, the comlustible stone.
Bern-steen is still its name in Holland. It appears from Tacitus (De Mor.
Germ.) that the ancient Germans called it Glas, which is probably the same
word with our Glass.
151
Plato and Aristotle recommended it for many virtues, and
Thales observed that it attracted light bodies, 600 years be-
fore the Christian era. It was in high esteem as a luxury
among the Romans.
Since writing the above, I have been favoured by Lord
' Dundas with references to those best informed respecting
the coast and rocks at Whitby, especially the Rev. Joseph
Harrison, who gives us every reason to believe that Amber is
seldom or never found on the shores or cliffs near Whitby,
although they produce the substance usually found near it,
viz. Jet, which has been known there for many years. Indeed
it would appear that Dr. Woodward was imposed upon.
It is not a little curious that the Fat or Opaque Amber
may often be made transparent by being boiled in olive oil ;
but in most instances it thereby acquires flaws that have
been compared to fishes’ scales entrapped in the same man-
ner as insects.
fad
PR
‘aaeal
. ; Bk?
=
Fag +i4 nah £m:
153
TAB. CCLXXYV.
CALX_ carbonata.
Carbonate of Lime.
Div. 1. Crystallized.
Tue perhaps numberless variations in the forms of the
crystals of Carbonate of Lime, however difficult they may at
first be considered by many, are one of the surest proofs of
the necessity of attending particularly to their formation ; for
when we are a little conversant with them, they seldom fail to
indicate the place to which a specimen should be referred.
The present variety is formed of two regular hexaédral
pyramids applied base to base, each terminated by the faces
of the equiaxe rhomb—see tal. 34—the alternate solid
angles near the summit, being bevelled, form the little that
remains of the metastatic variety—see ¢al. 33. The inci-
dence of the three edges of the termination on the cor-
responding edges of the pyramid is about 122°, that of the
face of termination on the other three is nearly 133°, and
the two pyramids on each other about 145°. The crystals
are apt to vary a little, especially those in the next plate,
for which these measures will serve.
The right hand geometrical figure in this plate shows the
position of the primitive rhomb in the centre, and the left
hand one shows the oblique base of the curious mackle that
belongs to this modification, to assist in the explanation of
the next plate.
The crystals are extremely neat on this specimen, which
is in the possession of Mr. Lowry, whose remarkable abi-
lities are so well known. It came from Ecton-mine, in
Staffordshire. The same gentleman has a group of crystals
of the same form from nearly the same spot; one crystal
about ten inches in circumference, and nearly as long.
a4
154
The present specimen is rendered handsome, and serves two
purposes here,-by giving an example of yellow fluor.
There are also some varieties of octaédral Pyrites, a few little
spots of Galena, &c. The whole stand on a piece of shat-
tered schistose Limestone.
TAB. CCLXXVI.
Carbonate of Lime.
Tuts singular modification of Carbonate of Lime came
from the neighbourhood of the Ecton-mine, Staffordshire,
having been gathered by W. E. Sheffield, Esq., who was
so good as to favour me with the use of the specimen. The
depth of two of the facets of each pyramid, or the want of
a proper supply to give them a proportion to the others, is
a sort of deception, as they are nearly the same with the
foregoing, except one or two additional facets, and the dia-
gonal mackling. Thus the wholeis shortly accounted for;
and as these are extremely rare specimens, I was glad of an
opportunity to show them, and to explain so instructive a
lesson in Crystallography.
The gangue is chiefly of variegated Pyrites, but in another
specimen possessed by my friend there is much Sulphate of
Barytes with the faces as in the geometrical figure at the
bottom of tal. 72, giving them a singular sharp-edged ap-
pearance; and the modifications of the Carbonate of Lime
are rather more mixed, or have the other ends of the crystals
appearing in some parts beyond the mackling, rather irre-
cularly. Iam the more gratified in having the use of these
specimens, as the mackle in such a direction in Carbonate of
Lime has not, to my knowledge, been noticed before, nor
is it mentioned by Haiiy, being in itself very puzzling.
The place of intersection is parallel to one of the faces
of the equiaxe rhomb, or to the edge of the nucleus, and
corresponds with the diagonal fractures that may be obtained
from some yarieties of Carbonate of Lime.
Ang.1.2808. Publish lu Ja! Sowerby London.
76
nt
La
;
As
LZ
.
aK
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ie
277
fug21808.Publisha by Jai Sowerby London .
155
TAB. CCLXXVII.
TITANIUM oxygenizatum, var. ferriferum.
Menachanite. Ferriferous Oxide of Titanium.
Class 3. Metals. Order 1. Homogeneous.
Gen. 20. Titanium. Spec. 1. Oxygenizatum.
Var. F¥erriferous.
Syn. Menachanite. Kirw. 2.326. Gregor.
Nigrine. Karsten, 56.
Titane oxidé ferrifére. Hauy, 4. 305.
We are indebted for the first discovery of this curious
substance to the penetration of our. ingenious friend the
Rey. Mr. Gregor, who examined it in the year 1781, and
discovered that besides Iron, it contained a new metal,
which he called Menachine, but which appears to have
been the same with what has since been discovered in the
Red Schoerl by Klaproth, and is named Titanium. This
name has obtained most general use, on account of the
great authority of the chemist by whom it was given, al-
though Menachine might with much propriety have been
preferred, as being originally given to the substance by Mr.
Gregor; he being undoubtedly the first who named it, as
well as the first discoverer of it. The term Menachanite
has been applied to the substance here figured from the
name of the place where it was first found, the valley of
Menachan, in Cornwall. The same substance is said to
have been since met with in the Island of Providence and
in New Holland. It bears some resemblance to gunpowder,
but has rather more the appearance of grains of Plumbago.
The grains do not assume any particular shape, some being
156
flattish and angular, and others finely granulated. Mena-
chanite is easily pulverized, is rather brittle, and slightly
attractable by the magnet. Its surface is opaque, some-
what shining, grayish black, retaining its colour when
pounded, in which it differs from the Tron Sand of ¢al. 197.
By analysis, Mr. Gregor found it to contain
Oxide of Titanium . . 45
Oxide'of Iron) <=.) 47 AG
se Noe ec ce ee
Among the loss a little Silica and Oxide of Manganese
are included. A trifle of Oxide of Manganese, Silica, and
Alumina have been found since:in some specimens by
othet persons ; but as these may be reckoned rather adven-
titious, Mr. Gregor’s seems most to be depended upon.
Klaproth, Hecht, and Vauquelin have clearly proved Mr.
Gregor’s accuracy by their analyses,
Spec. Grav. 4°497.
The Oxide of Titanium, when separate from the other
ingredients of the Menachanite, has these peculiar pro-
perties. It may be reduced by exposing it with charcoal to
a violent heat, when it assumes a deep copper colour, with
much lustre and brittleness, but is elastic when in thin
plates. It is extremely difficult of fusion. It is easily
tarnished by air, or oxidized by heat, becoming blue, and
detonates when thrown on hot Nitre. It is said to form
three Oxides, viz. the blue or purple, the red, and the white.
We, as well as Haiiy, consider the Nigrine of Karsten as
a variety of Menachanite, but generally much freer from
Tron.
_tua.22808. Publisha bu Ja? Soni, Lona
157
TAB. CCLXXVIII.
PLUMBU™M_ oxygenizatum.
Minium, or Red Ovide of Lead.
Class 3. Metals. Order 1. Homogeneous.
Gen. 15. Plumbum. Spec. 1. Oxygenizatum.
Div. 1. Amorphous.
EE
Tiais new and truly curious production is unusually in-
teresting, as being found naturally formed, and will pro-
bably afford a lesson for the chemist, as the work of the
great Laboratory of Nature: especially as it exposes a sub-
ject usually formed by a sort of volcanic process, if I may
so term it, and which yet has here every appearance of a
Neptunian origin. Possibly the very process of thus pro-
curing it may be of consequence enough to teach us how to
preserve its most inimitable tint, which has hitherto been a
great desideratum. It should seem by the nature of the spe-
cimen that something has wrought a sort of furrow or con-
cave passage through the Galena, and that this was a very
powerful menstruum, penetrating it so deeply in some
parts, and in such a manner, as to give the appearance of
worm-holes: these holes are lined with the Oxide of Lead
of the usual scarlet colour, in a fine-grained powder, about
the thickness of paper, adhering to the Galzna rather
closely, and which, when separated, shows a dull roughish
site with a corroded appearance. Upon the surface of the
Minium we may almost recognise a substance between
Massicot and Litharge, about the same thickness, sepa-
rating in irregular patches, in extremely fine particles,
which, with a magnifying glass, seem to sparkle, and
have something of a scaly appearance. In some parts they
158
are of a lighter yellow and nearly white. as the colouring
of the figure indicates.
In a letter to Sir Joseph Banks, from Smithson Tennant,
Esq., it will be found that he has lately discovered this
substance abroad *.
* See Phil. Trans. for 1806, and Phil. Mag. xxvi. 114.
4ur.r2808 PuBtisha bi Jal Sowerky ondon
159
TAB. CCLXXIX.
CUPRU M_hyperoxygenizatum.
Peroxide or rather Hydrate of Copper.
$$
Tue specimen here figured was brought from Dalehead-
mine, in Cumberland, and is in the possession of W. E. Shef-
field, Esq., who, with the utmost generosity, has offered to
lend his best specimens for this public use. I have only
seen one exactly corresponding with this as to its waxy ap-
pearance. In the drops, and general form, they well agree,
as they do also in fracture; so that it might be called a
specific distinction. JI was favoured with this latter by
Mr. Duncan of Penzance, and I have a very neat specimen,
somewhat approaching it, from Scotland, for which I am
obliged to my kind friend Gilbert Laing, Esq.
This variety is certainly rare, especially in fine specimens,
and may be considered as one of the harder varieties of
Malachite. The interior of the mamillz is formed of com-
pact radiated Carbonate of Copper of a darker colour.
At Dalehead-mine is also found the elegant satiny full
green radiated Carbonate, so much prized, and chiefly
known as of Siberian origin. I have indeed small speci-
mens of it from North Wales ; but hope ere long to figure
a satisfactory one from Dalehead.
The gangue of this and the following specimen is a va-
riegated Pyrites or Sulphuret of Copper with Quartz.
160
TAB. CCLXXX.
urs specimen is remarkable, not only from its being
unique, but from being found by Mr. Sheffield in Dale-
head lead-mine, in Cumberland. The vitreous appearance
might give occasion for dispute between the Neptunians
and Voicanians; but as I consider both modes of forma-
tion to be more or Jess concerned in many instances where
it has been imputed to one only, I shall leave it to every
philosopher to consider it in his own way, as such a speci-
men may give equal force to either theory when considered
alone.
This specimen consists of a green Oxide or rather Hy-
drate of Copper united to almost half its weight of Silex.
It is quite vitreous or glassy in its fracture, with a semi-
transparency, full of irregular cracks or flaws, like the
potter’s glaze, or like moderately diluted gum that is
cracked after being left to dry, and when thinnest, not un-
like cracked varnish. Its colour and brilliancy are quite
similar to verdigrise, which is only a preparation from Cop-
per; nor do we know many other substances which produce
this beautiful green, which in some mtances approaches the
green Patina found on old coins. Under the blowpipe its
brilliancy is lost, and it assumes a dark brown colour,
but the fragment is difficult of fusion. Small pieces
thrown into dilute Nitric Acid gradually lose the Copper
they contain without effervescence, and the Silex remains
unaltered in form. Of two grains and a half, about one
erain and a fourth remained transparent when wet, but
proved opaque white when dry, and possessed the characters
of Silex.
tg at0b. Liblishd by Jat Soverby London .
note
Se
London.
+
da
lisha by
Lub
Cct2.2808.
Y Sowerby
161
TAB: -CCLXXXI.
OXYGEN Aqua.
Water, Ice or Hail.
Class 1. Combustibles. Order 1. Homogeneous.
Gen. 4, Oxygen. Spec, 2. Aqua.
Div. 1. Crystallized.
Gen. Cuar. Permanently Gaseous. In all cases the
supporter of Combustion.
Spec. Cuar. In combination with Hydrogen.
EEE
T wave already introduced a subject from the skies, and it
is not a little remarkable that it should be necessary to do
so again, but to show the insulated crystal of Water I have
no other resource. Indeed Water in any form may be
deemed more absurd in British Mineralogy than the Me-
teoric Stone. As it, however, belongs neither to the
Vegetable nor Animal Kingdoms of Nature, it must remain
to the Mineral one, and this with the more propriety as its
ingredients are found dispersed in that division. It has
long been known that 85 parts of Oxygen Gas and 15 parts
of Hydrogen Gas, combining at the expense of the greater
part of their Calor, or the Galvanic or Electric Fluids, &c.
form Water, and that this becomes solid, or Ice, at 32° of
temperature, being liquid above that point. Hence it is
mostly in the latter form that it is best known, such being
the more usual temperature of the atmosphere, especially
in moderate climates: in winter indeed it is often in the
VOL. Iil. M
162
solid state; but on the earth it does not appear to form
itself into any distinguishable shapes or crystals, as it is
mostly condensed, and dependent on adjacent subjects that
are not favourable to equal, or what we call perfect crystalli-
zation, and being either in thicker or thinner plates, or
shooting into rather undetermined spicula.—In the at-
mosphere, however, it is sometimes surrounded by a more
equal medium, so that every side has an equal opportunity
to form; and thus we are allowed to see the true shape of
the crystal of Water with as much precision as that of an.
earth or a metal, nay, even more so than Quicksilver,
which I believe has not been discovered. As the crystal
of Water seems very undetermined by the authors I have
examined, it gives me great pleasure in being able to show it.
As hail, its crystals are in general rather opaque tetraédrons,
formed of roughish accumulated plates—see the top and
right hand geometrical figures—but sometimes in smooth,
somewhat rounded transparent tetraédrons—see the left
hand figures. Other forms have been seen; but these are
mostly clusters of indistinct granula or spicule, or irre-
gular solid masses, or both combined, as in the large
hailstones that fell at Menabilly in Cornwall, as observed
by my friend Philip Rashleigh, Esq., where the opaque,
perhaps minutely crystallized granula were about the size
of a pea, and enclosed in flattish irregular masses of ice,
half an inch in thickness by an inch and a half or more
in length or breadth.—See Mr. King’s Account of the Me-
teoric Stones. Water is so useful in a fluid state, that neither
mankind nor any part of the present mundane system
could exist without it. In the solid state it is most qui-
escent; but at the temperature to which it is most liable
to be exposed, in various seasons and climates, it proves a
compound ever assisting in the grand scheme of the uni-
verse, as the cause of vegetation, beginning that life which
is perfected in animals. It makes in most instanees the
163
greater bulk of the vegetative body, either disposing the
foundation, and conducting the base or root, governed by
the unfolding organs of the seed, to descend in due order ;
or the other parts to grow and ascend, helping the arrange-
ment by a sort of natural union, and guiding the necessary
particles to build the wonderful fabric. Since Water has
been found to consist of three elements, viz. Hydrogen,
Oxygen, and Calor, it has also been found to be soluble in
the common air, in various proportions; in which case it
is capable of acting either by itself, or in conjunction with
the common air; so that the effects and changes to be
wrought upon substances where this fluid comes in contact
with them must be mnumerable. Thence the many ap-
pearances that are otherwise unaccountable may be the
more easily comprehended.
Water often contains various substances in solution,
such as salts, earths, and even metals. Thus Epsom Salt,
or Sulphate of Magnesia, Sulphate and Super-carbonate of
Lime, Carbonate of Iron, or Sulphate of Copper, &c. are
numerous varieties, and are commonly called Mineral
Waters; but as they do not properly constitute different
species of Water, one figure is sufficient in this work, unless
the varieties of form in the crystals of Snow should warrant
more.
‘i
Wt ;
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AN
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War i? sibrentiy |
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PEE) bey Sa
3d va, a tt
NGA ReoamsA 3 he arene! fe oie
Tey:
‘an
7 oe gn
Paes Abed
Be tim heal
2 iy i =)
“oud (\\
O0t 7808 FAME TH bar Feet Sowerby London
165
TAB. CCLXXXII.
CAWULX carbonata, var. Stalactitica.
Stalactitic Carbonate of Lime.
Div. 2. Imitative.
ed
Tue remarkably chimerical or whimsical appearance of the
formation of this Carbonate is truly admirable and in-
structive, showing that Nature kindly indulging us with so
many elegances for amusement, knowledge, and improve-
ment, must excite the most lively sensation of gratitude in
every sensible mind. ‘
I consider this as a sort of gradation from the Carbonate
of Lime with the usual rhomboidal fracture, to the hard Car-
bonate of Lime with the irregular or rather flinty fracture. Its
fracture is rather curved and irregularly plated. It is some-
what harder than the former, and generally of rather more
specific gravity. Sometimes the harder Carbonate of Lime
—see the next plate—partly coalesces with it; see the
opaquely tinted whiter parts.
The varieties of its forms are beyond description ; and
the manner of the curvature in every varied direction.
Branching, and inosculating, is not only new, but rare in
Carbonate of Lime, nor do I know that it has been before
described. It must be observed that the Sulphate of Lime,
tal. 21, however curved, is more involute, and otherwise
varying. The specimen here figured differs somewhat in
hardness: the more opaque parts, however, are in general
hardest. It is mostly semitransparent, with a somewhat
166
waxy appearance, sometimes having a beautiful satiny
or even pearly gloss, and showing occasionally some facets
of small crystals. It seems to lead us through the mineral
aggregation to the growth of plants, and hints to us their
connexion, which is, however, more conspicuously shown
in the next plate. I have called this chimerical, because
we never see two specimens alike, and it seldom happens
but that they convey, in the smaller or larger masses, an
idea of something monstrous, not unlike some of the
strange Imaginary figures of the Chinese.
Sowaty Londen.
by Jat
Lublisha
0ct.2.18 08.
167
TAB. CCLXXXIII.
CALX_ carbonata dura.
Hard Carbonate of Lime.
Div. 2. Imitative.
Tue elegant specimens of Hard Carbonate of Lime from
Eizenarzt in Styria have long been recognised under the
misleading name of Flos-ferri. The no less elegant speci-
mens of our isle lately discovered at Dufton in Lan-
cashire are, if possible, more truly interesting to us, as a
product of our own country, rich not only in the conve-
niencies of life, but in materials for that sort of instruction
which teaches the ways of Providence, so that we cannot
forget to adore the infinite wisdom which even provides for
our curiosity, and thus proves an incitement to knowledge
of the first utility. In this fossil we see so much of the
vegetable, and even of the animal structure, that our asto-
nishment is heightened beyond all common sensation.
The substance is a stone, though its formation is like
that of a plant or animal. The Agaricus tubiformis—see
English Fungi, tab. 382—or its variety, Ramaria ceratoides,
often has as little resemblance to vegetation as this; and
the Spheria digitata—English Fungi, tab. 69— shows,
when broken, very nearly the same conical and fibrous
surface, or fracture, as this stone, as I have endeavoured
to express, besides other analogies, whilst the coralliform
appearance or structure of it has been universally acknow-
ledged. The specimens I possess are so large and elegantly
108
formed, that they ought to be seen for any one to geta
just idea of them*: but te proceed with the description as
well as Imay. It is very compact, with a partly con-
choidal and somewhat splintery fracture, and more or less
composed of fibres radiating from the axis with an inclination
towards the ends of the branches, without any sign of the
usual rhomboidal fracture of Carbonate of Lime. This texture
continues throughout the whole formation, whether globu-
Jar, curving, branching, or inosculating. The centre is
generally most dense and opaque, and the outside opens
into spiculee—see the right hand figure ;—other fresh spi-
cule seem to be emerged as it were, and form a covering.
Sometimes the outward spiculz are very transparent, giving
a velvety appearance in particular lights. Sometimes there
are small grains of the equiaxed form of common Carbonate
of Lime upon the surface, giving it a curious appearance—
see the lower left hand figure.
Its gravity and hardness help to distinguish it. Probably
its density may answer for these characters, as it effervesces
with acids, and is dissolved very readily, like other Car-
bonates of Lime. The variety figured on the last plate will
often form one specimen with this.
* Mr, Sowerby will most willingly show them to his friends, on the first
or third Tuesday in the succeeding months of the year.
ie
s.
Sowerby Tandon
Oct.2. 2508. Publisha by Ja
169
TAB. CCLXXXIV.
CALX _ carbonata, var. foetida.
Fetid Carbonate of Lime, spherical and
concentrated.
Div. 2. Imitative.
— eer
Axtuouen this substance has been twice figured before,
the present specimen is so remarkably curious as to its
formation that it must excite astonishment, and I have
found that the best description must fall short of giving a
proper idea of it without the specimen ora figure. At first
it seems a wonder that the spherical ball should be formed
so regularly as in this, or so aggregated as in fab. 19 ; but
the somewhat stratified concentric rings, with a sort of coat
or covering, (as a formation of stone,) are at present un-
accounted for in a satisfactory manner, any more than
tab. 38, to which, however, some affinity may be traced.
But as the formation is more external, and the inside partly
crystallized, although somewhat confusedly, it is still more
unaccountable. I broke one on purpose to see how it ap-
peared withinside, expecting a section would either show a
continuation of the concentric rings, either in striz, or
casing like an onion, or that I should be led directly to the
manner of its formation; but as it does not show what
was, or might have been, expected, it may be somewhat
satisfactory if I try to account for it, although it may ap-
pear a little too theoretical.
On examining the broken one, there are some signs of a
170
crystallization radiating from a point, or centre, approach-
ing in appearance the inside of tab. 38. Thus the sub-
stance consolidated chiefly as to its inside; but being in
some parts of a more earthy fracture, there probably was
much undissolved matter, which interrupted the crystalli-
zation, and so it is occasionally irregular in its appearance.
Some parts of the outside, therefore, it seems, were suc-
cessively covered with these rings, as the water evaporating,
in the time of aggregation, allowed of them: afterwards
the substance of the coat adhered less perfectly between wet
and dry, not so easily attaching to the drier edges of the
rings or circles: and this may be in part understood; for it
is only where the coat easily separates that these circles are
seen, and should we by a little help detach any other ad-
jacent part of the coat, there is little or no continuation of
them. Sometimes there are partially two or three coats,
some very thin, and occasionally two or three balls are
found adhering together with the circles on them. These
stones are not always what are called Swine- or Stink-stones,
some having little or no Sulphuretted Hydrogen, which 1
believe is the cause of fetidness in this particular species,
though not in all Stink-stones.
a
002.1808. Publish by Ja* Sowrby,London.
£71
TAB. CCLXXXV.
CALX carbonata.
Crystallized Carbonate of Lame.
Div. 1. Crystallized.
—
Ar the commencement of the study of British Mineralogy
I could scarcely conceive the beauty, novelty, and in-
structive utility of it im our own country; but every in-
vestigation of Nature’s admirable ways is replete with the
most satisfactory proofs of the necessity of such research,
and the most exalted writers have been most indebted to it
to give that universal celebrity that 1s attached to their
writings.
« For thou, Lord, hast made me glad through thy work :
I will triumph in the works of thy hands.””—Psalm xcii. 4.
To those acquainted with the nature of crystallization
and the formation of stones, this must be acuriosity. The
elements composing and decomposing each other, according
to affinity, are here displayed. While the Carbonate of Lime
was forming according to its due course from one men-
struum, another disturbed it; and thus it was diverted from
forming an entire regular figure, as the metastatic, or its
makle, and other additional facets are formed, some deeper
than others, so as sometimes to give them an obliquity,
and so to disguise the figure, and therefore it is difficult to
trace the operation. The upper left hand side of one of
the crystals shows most of these facets pretty completely,
some of which are very shallow, but one is very sufficiently
marked. This is only on one side, or the half coat of the
crystal ; for the interruption on the other side leaves the
included metastatic crystal half exposed, whose faces are
often seen roughened by corrosion. ‘This coat often over-
laps the edges, and finishes irregularly. It would seem that the
172
powdery white ahout the gangue has been precipitated,
covering some, and filling other crystals, so as to appear
as if filling a case—see the lower right hand part of the
Jjigure. This white part is granular, almost of the texture
of Carara marble, but is more perfect in the following spe-
cimen.
TAB. CCLXXXVI.
Tus, and the last figure, have nearly the same form of
crystallization, and also in some parts the appearance of
Carara‘tarble more complete, with a very white surface.
Among the substances concerned in this composition or
decomposition we find Sulphuret of Iron neatly coating the
crystals; which are more perfect than those in the former
figure, few having the corroded or half coated appearance;
and so accurately-does the Sulpburet of Iron fit upon most
of them, that it could not have been discerned but that
they were solid metallic crystals of Sulphuret of Iron, with
a gold blued steel, or copper-coloured, appearance. These
so complete-coverings are very thin, and, when magnified,
are found to be composed of minute bubbles, with-the fine
mamumillated- appearance of the bubbled fusion belonging to
metals, although the effect of a fire to produce such a fu-
sion would certainly have given opacity to the crystals
covered with it, which the broken ones discover to be
otherwise; that is, to be Carbonate of Lime.
I am obliged to my worthy and scientific friend the Rev,
Dr. Jackson for presenting me with these remarkable spe-
cimens, from the Dimple mine near Matlock, which give
a fine idea of the changes passing on, in darkness to us,
although our excavations, when mining, may let in fresh
agents to the veins or lodes, which may probably assist in
them, and may sometimes, though unknowingly, be useful,
or the contrary. It may, however, be wortha little attention,
as in some instances it may be of great consequence.
266
0.21808, Published by Ja? Sowahy Louie,
287
9QCAMWGS LubwsNE by Jat Sowaby Lendow.
TAB. CCLXXXVII.
FERRUM _ sulphureum.
Sulphuret of Iron. Hair Pyrites.
Div. 2. Imitative. Capillary.
EB
Whuen we find a curiosity from its rarity and peculiarity
invaluable, we may with great satisfaction contemplate its
nature from a figure and description, first as learning that
such a thing exists, and next as such a representation ap-
proaches nearest to possessing an object which only one or
two can actually possess.
The specimen here figured was gathered by W. E. Shef-
field, Esq., in Wales, and therefore truly British. We are
indebted to the generosity of that gentleman for the use of
the very delicate specimen. The extreme tenuosity. of the
fibres is only to be equalled by the spider’s attenuated thread.
The Pyrites shoots so like a spider’s thread across the hol-
lows in the Septarium, which is an argillaceous iron-stone
related to tab. 61, that, as the specimen really had got
some spider’s webs across it, they were difficult to be distin-
guished. The web, however, would not bear the gentle
breath of wind without being put in motion; but had it
been less carefully kept, the real webs might have been the
strongest. Some of the threads are so thin, that it is difi-
cult to see the golden hue of the Pyrites ; afew are thicker,
80 as to show it tolerably distinctly.
F ee ate eect . be,
rt Ray ee oe
&
'
D.
2
a
DA HOB. PibUAA by Jie! Sowerby, Lenton .
173
TAB. CCLUXXXVIII.
MOLYBDENUM sulphureum.
Sulphuret of Molybdenum.
Class 3. Metals. Order 1. Homogeneous.
Gen. Molybdenum. Spec. Sulphuret.
Gen. Cuar. Spec. Grav. 7°400. Nearly infusible.
Colour yellowish white. Capable of being formed
into an acid. |
Spec. CHAR. Molybdenum combined with Sulphur.
Syn. Molybdéne sulphuré. Hauy, 4. 289.
Molybdéne. De Lisle, 3. 4. note 3.
- Molybdéne sulphuré; Sulfure de lee an
De Born, 2. 119.
Warsserblel. Lmmerl. 2. 541.
Molybdenite mineralized by Sulphur. Azrw. 2.
322
ad ad O
‘Tuts ore is said to have been found in Scotland. The
specimens here figured are, the upper one, from near Me-
nabilly in Cornwall, and the lower one, from Coldbeck in
Cumberland, and are now first published as discovered in
these latter places. Mr. Sheffield first told me of its being
found in Cornwall; and Mr. P. Rashleigh was so good as
to procure me a specimen about a twelvemonth since; and
about the same time I had some specimens of rocks from
Kendal, among which was the one figured at the bottom of
the plate. The first is lodged in small detached parcels
very sparingly in largely plated Chlorite or Talc, among
176
_Arsenical Iron with some light Quartz; the latter in red
Feldspar with Quartz and Mica, in which are interspersed
smallish scattered particles of Pyrites, and the Molybdenum
is dispersed in little particles, mostly on one broadish face,
of a natural crack; but on the other sides of the stone,
which is about half an inch thick, there is not the least
particle to be seen. It therefore appears extremely local
and partial. At first sight it has occasionally been con-
founded with Plumbago ; but its micaceous foliated texture
distinguishes it; besides, the lustre is truly metallic, and
its colour bluer. Its folia are rather easily divided ; it soils
with less ease than Plumbago, and its mark is paler. It is
bright in itself, and does not allow of being made brighter
by scratching. I do not know that it has been found with
determined crystals in Great Britain; I have, however,
shown the form of the crystal proper to it. As we possess
many things besides the few that I have published, that
have been chiefly ascribed to foreign habitats, I shall be
glad to add them to our list *.
* T intend to form a Supplement to British Mineralogy by publishing
such few as do not seem likely ever to appertain to our island; see Adver-
tisement on the cover.
289
Lendon-.
: Sowerdy,
Thad dar Ja
Publ:
Dec.2.2808..
177
TAB. CCLXXXIX.
CALX carbonata.
Coral-like Carbonate of Lime.
Div. 2. Imitative.
ee
We read frequently with astonishment of vast Coral rocks
in different regions of the globe, when it is only our neg-
ligence of the productions of our own country that makes
us wonder, since every Limestone quarry and the adjacent
places teem more or less with Corallines of various species,
from Wiltshire to Yorkshire, Cumberland, &c., and even to
Scotland and Ireland. Thus our island is almost all Coral
rock externally, as will be shown, although some species
are more local than others. at &
The specimen from which the upper figure is taken re-
sembles Madrepora radiata of Solander and Ellis, tab. 47,
Jig. 8, but the artist seems to have forgotten the little in-
tervening lamellated stella, or perhaps the specimen had
not them. Gmelin and Solander do not mention any ha-
bitat. M. cavernosa of Espers Pflanzenthiere seems to be-
long to the same Coral. It has so exactly the appearance
of a recent Coral, that it became quite necessary to show
that it really was a mineral, in order that mineralogists may
if possible be guarded in their conclusions, and examine
further than the commen external structure, however ap-
parently decisive.
The organic appearance in this specimen is given by
crystallized Carbonate of Lime, and is distinguished by its
VOL, III. N
178
fracture, and in some parts we see the stalactitical form of
infiltration, as it were, into the exquisite mould formed by
nature around the animal remains of organization. I was
favoured with this specimen by Charles Stokes, Esq. It
was picked up in Wiltshire.
The specimen figured beneath is very hike Madrepora
ananas of Solander and Ellis, tab. 47, fig. 6, said by
Gmelin to be found in the Mediterranean sea, and in
America, and frequently fossil... It is nearly whole,
having been bounded by a sort of shapeless rocks when
formed by the animal inhabitants. This is, if possible, more
perfect than the last; but its dingey appearance might
give us reason at first to suspect it to be the remains of ©
some old Coral, for it has very little of the appearance of
Carbonated Lime. It was sent me from Kendal Fell in
Westmoreland.
The lamine of the nuclei are often curved in these spe-
cimens, and more irregular than in the spines of Echint,
which, as in those figured tab. 151 and 152, have them
universally as regular even in the minutest of their parts
as in the metastatic crystal.
Dee. 12808 Lublishd ty Jat Sowerhy, Lindon .
9
TAB. CCXC.
CAQLX carbonata coralliformis.
Coralliform Limestone. -
Div. 2. Imitative.
Denrzysutre, Cumberland, Westmoreland, and some
parts of Scotland and Ireland, have large remains of these
coralloid Limestones, often called Marbles; which, when
compact, being cut and polished, serve for tables, slabs,
and other ornamental masonry. They vary much in co-
jour, are of different stronger or paler reds, and sometimes
the Madrepore is light with a dark or black ground; but I
have some exactly the reverse, given me by Lady Wilson,
from the north of England. Some specimens are of a
larger variety, or a species nearly allied to this. Perhaps
there are numerous species, as we have no reason to sup-
pose there were not as many Corals formerly as now, and
some are so nearly alike that we can scarcely determine
the different species. The redder ones which I have by
favour of Gilbert Laing, Esq., are found at Limeworth
near Arundale in Dumfriesshire, and are often very beauti-
ful; they are commonly called Bengang and Aboyne Marble.
This is a larger species than that before described, and is
lodged in red Limestone, which might be called Eisen-calk
with as much propriety, by the Germans, as Quartz or
Flint, coloured by red Oxide of Iron, is called Eisen-kiesel,
and Clay under similar circumstances Eisen-thon. If the
nomenclature is good, there cught to be such a concordance,
when nature agrees with it.
N@
180
I have given these examples to show some varieties de-
pending on what is commonly called petrifaction, and also
to show that the remains of organized substances have
passed into the common soil from whence they in part
originated, and are now become evident to us by the me-
morials left as proofs of such existence. In Limestone
many curious subjects are to be found ; but it is only in-
tended here to give a general idea of them ; and after show-
ing a few other sports of Nature in different substances, it
is expected that the remainder will be pretty well understood
in mineralogical hands.
Zoek
dom,
, Lona
Jal Sowerky,
2808, Publish a by
De.
181
TAB. CCXCI.
SILEX Quartzum coralliformis.
Coralliform Flint.
Div. 2. Imitative,
eee
Tus is one of the most beautiful, and perhaps local,
of the Flint Coral formations, and is found in tolerable
abundance in a field near Tidsbury, Wiltshire, in pieces,
sometimes as large as a quartern loaf. Some specimens
show the remaining form of a real Coral most perfectly ;
having at the same time little globular infiltrations, as if in
the act of filling the spaces of the Coral with a whitish
calcedony or cachalong-like substance, which more solidly
pervades the Flint in other parts; and again a considerable
part of the petrifaction is in so solid a state, that it retains
a great degree of semitransparency, and either the reticu-
lated or stellated structure ; or both remain distinguished by
the whitish opaque Calcedony, so beautifully, that it is one
of the most curious subjects that I know of for orna-
mental jewellery. I have most of the varieties here figured
as one speciinen, but not on the same piece. Besides the
stony representation of a Coral, perhaps new to our cata-
logue, there often remains the oval hole of the Mytilus or
Pholas, which are known to bore holes in old Corals and
various rocks.
I am obliged to my good and very generous friends,
Thomas Mead and William Cunnington, Esquires, for
most of my specimens of this curious modification of Flint,
182
and I have some specimens of Coral Limestone from the
last-mentioned gentleman from Steeple Ashton, which
have sufficient of the remains of the shell to discover by
comparison that it agrees with AZytilus lithophagus of Linn.
Trans. vol. 8, or the other new species, which F am in- ~
clined to think the cross-beaked one is, although the beaks
are only a sort of accumulated appendage. I think it ought
to be distinguished by some title different from the usuak
one, and might therefore be called Mytilus curvirostris.
The signs of these, and innumerable remains of organiza-
tion, seem to be the cause of the various spots in all
common Flints, although they are often too much oblite-
rated to show it, as it happens in some parts of the above
specimens.
The Flint appears to have first entered into the substance
of the Coral, and then seems to have been filling up the
spaces between the ramifications, and is in some places to be
detected in the operation; but some Flints have the general
shape of a Coral, but not the least resemblance in other
particulars. I have such as show what they are by the in-
ternal structure, from different parts of Wiltshire.
292
183
TAB. CCXCII.
SILEX @rotteuns coralliformis.
Coralliform Quartz.
Div. 2. Imitative.
Havine shown some modifications in Limestone and
Flint separate, it becomes somewhat necessary to show
them in different substances; and the more so, as they
have not been noticed by mineralogical writers. Varieties
of the present sort of specimen have been taken for roots
of different plants, as Ferns, &c. It is, however, another
sport of Nature, forming the imitation of one substance
which is imbedded in another. Thus the Coral is chiefly
Quartz, and is imbedded in argillaceous Limestone. The
Quartz in the polished piece is indicated by its taking a
better polish than the Limestone; for what polishes Quartz
grinds the Limestone, and will not give it a smooth surface;
‘and the specimen having been thrown about as a boulder in
the bed of some river, the Quartz is left beyond the Lime-
stone, resembling stumps of plants, in many instances not
much unlike stubble in a lump of earth encompassing the
roots. I have received pieces from the shore of North Wales.
This kind nearly resembles M/adrepora musicalis of Lin-
neus, figured Esper 1. Madrep. tab. 30.
Tags. CCXCIII is another species, branching like roots
dividing upwards, as happens in some plants, and the trans-
verse section would accord with that notion to those not so
conversant with Corals as with Plants; and in éad. 189 and
184
190 the divisions somewhat resemble the alternating la-
mellz of the tribe of Fungi called Agaricus, a form that
has given the name of Fungites to Corals, especially fossil
ones. The cells concentrate, and the outside remains
broken, much resembling some plants with decayed stumps.
The specimen here figured somewhat resembles AZadrepora
anthophyllites, figured by Solander and Ellis, tab. 29, but
the branches are not so club-shaped.
he a
i
Dee2.2803. Publish ty Ja! Sowaky London,
IG)”
Dee.21908, PBUSKA bu Ti? Sowctey Londen,
185
TAB. CCXCIV,
BARYTES sulphata.
Sulphate of Barytes.
Div. 2. Imitative.
When we are showing any distinct subject, it is often
necessary, for the sake of comparison, to exhibit others that
bear analogy to it, and may be confounded with it. Fre-
derick Hall, Esq., whose kindness gave me an opportunity
of showing the best specimen of crystallized Carbonate of
Barytes, tab. 76, favoured me with this specimen of Sul-
phate from Arkendale in September 1805. It now seems
to be an appropriate time to exhibit this, and the pleasure [
have in doing so may perhaps only be felt by those who
occasionally share such friendly favours. It is, if I may
use the term, a vermiculated Sulphate of Barytes, or some-
what like Sabella rudis, which accumulates bits of shells,
as if an abundance of worm gluten, having accumulated
every thing in its way, found chiefly Sulphate of Barytes
to adhere to it. It is. composed of irregularly formed
tubes, many of which are distinctly angular with from
three to five angles, the tubes curving and passing over
each other in every direction in a crowded manner. When
the present specimen was sent, Mr. Hall observed he could
have sent a very large mass but for the great weight and
bulk, it being as big asa bushel.
Primitive Crystals of Sulphate of Barytes are rather rare.
These tubes are nearly covered with them both‘on the in-
side and out, the tubes being rather opaque. Those within
186
are smallest, and most irregular ; of the outer ones some are
nearly perfect, others slipped off, if I may use the expres-
sion; and the nuclei falling on each other somewhat irre-
gularly are lengthened out beyond the proper angle; some
are a little rounded, and some flattish ; others have trunca-
tions on their angles, &c.—see fig. 1, 2, 3, 4.—and in
some instances resemble the Pearl-spar, al. 19.
I have a specimen that was in the collection of my late
Jamented friend Mr. Day, from Matlock, that has quartzose
tubes which have much the appearance of the Coral, tab.
292, each surrounded by Cubic Fluor and Sulphate of
Barytes in nearly lenticular crytals, like tab. 96.
iy
Dex BoE PDGHA bu Ja? Sowerky London,
187
TAB. CCXCV.
PLUMBUM Arseniatum.
Arseniate of Lead.
~ Class 3. Metals. Order 1. Homogeneous.
Gen. Lead. ; Spec. Arseniate.
Div. 1. Crystallized.
$$ —____
‘Tuts new and at present very rare substance, but lately
discovered in Cornwall, is a token of our possessing in our
island some substances that are not found elsewhere. I
am obliged to the Rev. William Gregor (who has been
mentioned as the first person who analysed the Menacha-
nite, fab. 277.) for ascertaining what this substance is,
and also for the delicate specimen figured. In colour and
form of the crystal it somewhat resembles Phosphate of
Lead.—see tal. 84,—which, however, is seldom so brown
as this, and is less transparent: besides, the crystals of
Arseniate have some characters which I do not know to
occur in the Phosphate of Lead, such as the fasciculated
structure found in most of the crystals, even where the two
ends are apparently regular ; also a considerable degree of
lustre, transparency, and neatness at the terminal edges:
besides, it is considerably softer than Phosphate of Lead,
and rather harder than Sulphate of Lead. The crystals are
scattered upon a gangue of white Quartz.
With the specimen sent by Mr. Gregor, he favoured
me with the following account, which, as it is likely to
be very useful to the science, I consider it proper to publish
in nearly his own words.
188
‘© The mineral which I lately sent to you was raised in
across lode of Huel Unity in the parish of Gwennap in
Cornwall. At what depth or under what circumstances I
am unable to discover. A very small quantity only of it
has been raised. [I shall briefly mention some of the rea-
sons which induced me to pronounce this fossil to be an
Arseniate of Lead. A small fragment of it exposed to the
flame of a blowpipe in a golden spoon loses its yellowish
brown colour, and becomes white. Urged still further it
melts into a brownish mass, and continues in this fused
state without decomposition. If this mass be detached
from the spoon and placed upon charcoal, and if the flame
be directed upon it, a decomposition rapidly takes place,
and fumes, evidently arsenical, are extricated. Globules of
a fused metal are left upon the charcoal, which is marked
with that yello,.ish hue which indicates the presence of
- Lead. This fused metal is malleable: it ts soluble in
Nitric Acid, and forms with it a crystallized salt, the so-
Jution of which is rendered turbid by a drop of liquid Sul-
phate of Soda, and a heavy white matter subsides. A
piece of the mineral does not appear to be acted upon by
Nitric Acid in the cold. By long digestion, however, in
a sand-bath, the solution is effected. The transparency of
this solution is not disturbed by a-drop of liquid Muriate
of Barytes. Some crystals, however, appeared in small
quantity, after some hours, at the bottom of the glass.
A drop of liquid Nitrate of Silver caused the nitric solution
to assume an opalescence, scarcely however perceptible.
The purest crystals were selected ; but it is impossible to
free them perfectly from all the stony matter which adheres
to them. With a view to this extraneous increment, I
weighed 26-2 grains, and exposed the powder in a platinum
crucible to a very low heat, in which the bottom of the
vessel was scarcely red, for half an hour. I proceeded thus
cautiously, because the Arsenic Acid is decomposed under
189
certain circumstances, and it was a greater object with me
to ascertain the quantum of acid than of the water of
crystallization, The matter lost 0:48 of a grain. I have
reason to think that all the water of crystallization was not
expelled. It was now transferred to a silver crucible, and a
ley containing about 20 grains of Potash was gradually
digested with it, to dryness, and the crucible was at last
exposed for a few minutes on an open fire. All the soluble
part was elixated by distilled water, and the solid matter
left behind weighed 19°50 grains. I found that the alka-
line ley held a small portion of the mineral in solution: this
was previously separated : it consisted of Oxide of Lead,
Silica, and very slight traces of Alumina and [ron. After
being neutralized with Nitric Acid, liquid Nitrate of Lead
was dropped into it, as long as any precipitate was pro-
duced. The precipitated white matter weighed 14 grains,
which, according to the calculation of Mr. Chenevix, indi-
cates 4:62 of Arsenic Acid. In order to be certified that it
contained Arsenic Acid, I decomposed it by means of half
its weight of Sulphuric Acid. I obtained a dry granulated
matter which attracted the moisture of the atmosphere.
It had acid properties. . Dissolved in water, it precipitated
Cxide of Titanium from a solution of its Sulphate. Some
of this acid was exposed to the flame by the blowpipe in a
golden spoon: it bore ignition, and appeared to be a dry
pulverulent matter; but being heated on charcoal it was
speedily dissipated m copious arsenical vapours. Some of
the Acid was neutralized hy Carbonate of Soda. A solution
of this Salt, mixed with liquid Nitrate of Silver, produced
a copious precipitate of a brick-colour. As 1 thought
it possible that-all the ‘acid had not been extracted, I
boiled the 19°50 grains with a fresh ley of Potash. Some
of the mineral was again dissolved, but not the smallest
quantity of Arsenic Acid was obtained. The remaining
matter was dissolved in Nitric Acid, except.a small portion
of Quartz. The matter, also, which had been separated from
190
the alkaline ley, was dissolved in the same acid. The so-
lution was assayed by a drop of Muriatic Acid, which causéd
the precipitation of a white matter; but it was redissolved -
on shaking the fluid,—a circumstance which proves the
absence of Silver. The Lead was separated by liquid Sul-
phate of Soda, and added together, the Oxide of which,
according to calculation, amounted to 17°179. Ammonia
afterwards precipitated a greenish white matter, a portion
of which a further addition of Ammonia redissolved. The
former proved to be Oxide of Iron = 0°17, and the latter
Oxide of Copper which amounted to about 0°1. The Silica
which remained undissolved by Nitric Acid, and which
was separated from the Potash, amounted to 0°815. The
Alumina was in too small a quantity to be estimated.
This, and the Silica, and probably the minute portion of
Copper also, proceeded, I believe, from the gangue of this
fossil. There is a deficiency of 2°836, which is to be at-
tributed in part, I think, to a retent of water of crystalli-
zation, in addition to the loss which is unavoidable in such
experiments, more especially when smal] quantities are ope-
rated upon, and a repetition of experiments is precluded
from the scarcity of the mineral.”
ead’: Oo roxisees. hea
Arsenic Acid . . 4°62
Water ¢5 - Suadotek sis Olas
SICA“. Se es ee. OSES
from 8s. DUR et One
Oxide of Copper . Ol
Alumina andloss . 2°836
26°200
Since the above was written, Mr. Gregor, having been
enabled to extend his experiments, has informed me that he
suspects the presence-of the Muriatic as wel] as the Arsenic
Acid in this substance, and that he intends presenting the
Royal Society with an account of the results of his more
extended experiments.
LA cf hi
296
Der.22808. Pub shi du Satboniiby, Londen:
191
TAB. CCXCVI.
FERRUM oxygenizatum argillaceum.
Argillaceous Iron-Stone.
Class 3. Metals. Order 2. Mixed.
Gen. Ferrum oxygenizatum. Spec. Argillaceum.
Div. 1. Amorphous,
See ee ee a
Tron-stones with vegetable impressions, or rather exuviz,
have been much noticed by many writers, but have scarcely
been admitted into mineralogical works: we should, there-
fore, be at a loss in most instances to find an account of
them, where we would wish to see them spoken of as a part
of the great system, especially of the phanomena of the
change, or seeming conversion, of one substance into an-
other. How bits of ferns or such plants should become so
regularly immersed in the clayey Iron-Stone balls upon the
Coal strata as they are found to be, can only be guessed at.
They not only contain a certain portion of the plant, but
often so regular a fragment that it would hardly be possible
to put a more complete fragment between two pieces of
clay, and press them into a ball, more or less ovate, as
these generally are. Were I to endeavour to account for
this appearance, I should suppose the plants to have been
formerly in or near ferruginous loamy or clayey soil ; that
their tops being much shaken as by a watery or showery
tempest, were continually heating against the unctuous
clayey cliff, and thereby became loaded with clay, till the
branch was detached by help of its cumbrous load; and
being at length covered by the deluged soil, has remained
to this time, a lasting memorial of a catastrophe of which
we can only expect to see such signs, although it seems to
say we are indebted to it for the Coal formation, which I
think is more confirmed in these instances. The peculiar
change here wrought is an excellent specimen to show us
that, under these particular circumstances, all vegetables
192
then existing, however large or small, might undergo, by
natural gravity, the changes that, as I have before said,
preserve whole forests in the different forms of coals for
the use of future ages. Thus the vegetable, in this instance,
could but allow of certain of its most volatile parts, which
gave it bulk when living, to pass into the clay, at the same
time admitting of others to help the change. In general,
Carbon and Bitumen are the ingredients of the remains,
though sometimes it is nearly the same with that of a
common brown dead leaf. The process of carbonization 1s
occasionally carried on above ground, as in some Fungi—
see Agaricus Elephantinus, tab. 36, and aurantius, tab. 381,
Eng. Fungi. Dead leaves often become carbonized aboye
ground; but the most frequent form of Carbon above
ground is organic, as in Spherie—see Eng. Fungi, tab.
372, 373, and 374, &c.
The observation that both sides of the impressions exhibit
the same side of the leaf, is nearly correct. It seems that
the front of the leaf is least liable to decomposition, and
that the impression is opposite to it; the substance of the
leaf, chiefly the front, remaining on the other half when
it is detached. Only the inner side of the cortex, appa-.
rently, is seen, and I do not know that any signs of the
fructification, which should be on the edge or other part
of the back, have ever been detected, either in the impres-
sion or otherwise. The two upper figures seem to have
been a Pteris, if we can guess by what remains. The right
hand one is the concave impression, and the other the
convex one that fitted it. The lower figure is a lobated fern,
and is also, perhaps, a Péeris. It is lodged in rather irony
clay, and has a coaly film in some parts, and small frag-
ments of coal are among the squame. Some have much
More coal on the leafy surface. Indeed the edges of some
of my specimens have little hollows, and a margin of Car-
bonate of Lime and Pyrites, where the fruit may perhaps’
haye been.
qe
verity Lo,
(1800 Publishad by Ta* Poy
Wad
193
TAB. CCXCVII.
SILEX Quartzum.
Crystallized Quartz.
Div. 1. Crystallized.
Whuenever we wish to contemplate the wonders of
Nature, we shall find ample scope for our researches in
every branch of the creation. But subjects which are
chiefly confined to ceconomical inquiries do not so readily |
arrest our attention, as those which occur less frequently ;
and it is a grateful task, when opportunity offers, to in-
dulge in admiration of the beautiful varieties that excite
observations which might otherwise be lost or neglected.
I am glad not to let the present object escape, as it is not
only very remarkable, but also very mstructive, being no
where mentioned before. The singular crystallization, $0
conspicuous on the edzes or angles of the pyramids, has so
extraordinary an appearance, that it could not fail of being
noticed by the miner ; and its uniformity, over a much larger
group than is figured, is a sign of its being originally extended
very orderly, however the position of the crystals would
seem to interrupt it. The parts of the faces between the
edges are covered with innumerable eighteen-sided crystals
in various positions, among which is scattered a large pro-
portion of light-brown Pearlspar, giving a pretty relief to
the whiter edges, which thus have a more star-like ap-
pearance.
The very curious modification of this crystal of Quartz,
lately brought from Cornwall, being quite new to me,
I could not but desire to have it shown. It often hap-
pens that the crystals of Quartz give some item of this sort
of modification.
VOL. III. O
298
isha by
Ja* Soverlyy London
195
TAB. CCXCVIII.
SILEX Quartzum, var. spongiosum.
Swimming Quartz.
Div. 2. Imitative.
Tuis curious formation of Quartz differs very much from
the last, and is therefore essential to this work, as it could
scarcely have been thought to be the same substance. In-
deed it might have been imagined as great a miracle to see
Quartz float in a large mass as the iron ax’s head that Elisha
caused to swim.—Masses of much larger dimensions than
this now figured will swim, and scarcely displace the water.
The present specimen ig too tender to bear handling,
and is thinner than any paper. It seems to have been
formed. in the interstices of some substance now entirely
decomposed from it, which would appear to have
had many thin cracks or flaws in it, crossing at various
angles. I could not detect the cast of any thing regular
about which it might form. I have some specimens very
much resembling the crumb of bread.
a ie ;
etme bse ts:
t
x
feet
ania sHelpee
4B 22800 Publickd by Jat Sowerdy London
197
TAB. CCXCIX.
TITANIUM oxygenizatum.
Oxide of Titanium.
Class 3. Metals. Order 1. Homogeneous,
Gen. 22. Titanium. Spec. 1. Oxide of,
Syn. Schorl rouge. De Lisle, 2.421. Sciagr. 1. 288.
Schorlecrystallisé opaquerouge. De Born, 1. 168.
Spath adamantin, brun-rougeatre. nn. de Chim.
1. 188.
Titanerz. Emmerl. 3. 378.
Titanite. Kirw. 2. 329. 2
Adamantine Spar. Kzrw. 1. 336.
Titane oxidé. Hay, 4. 296.
Great Britain is richer in Minerals than might have
been supposed ; and I am happy to have it in my power to
add still another to the catalogue, by favour of my friend
W. Lowry, Esq., whose kindness I have mentioned before.
This gentleman brought it from near Snowdon last summer.
When I figured the Menachanite, tab. 277, however con-
fident I might be that many Minerals, as yet only dis-
covered as foreign productions, might be added to the
British list, I must own [ did not expect to find Titanium,
except in the Menachanite, where it is known, by the aid
of chemistry, to exist in the form of an Oxide combined
with Iron. The satisfaction of seeing it in a regular for-
mation, distinctly identified and crystallized, is very grate-
ful. It is most usually found in Hungary ; but the present
specimen more nearly resembles the specimens from
St. Gothard, being on a gangue of Quartz and Adularia. 1
. 7
198
do not know of any other having been found in Great
Britain. It is of an intense semitransparent red, showing
~ occasionally a brilliant reflection. The crystal is represented
distinctly, and rather large, at the bottom of the plate, showing
the principal faces deeply striated, with the bevelings, trun-
cations, &c. The Quartz upon which it is found is rather
elegantly crystallized and grouped; but could not be drawn
with every advantage to show both subjects, and the white
Adularia, which is in small crystals, somewhat like those
in dabs. 211 and 212 in form, much resembling that found
abroad, being nearly as transparent as the Quartz, which
adds much to its rarity as being British.
Oxide of Titanium when crystallized is said to contain
little or no Silex. Its specific gravity is from 4°1025 to
4°246. It is soft, but not easily scratched with a knife. The
fracture in the present specimen is vitreous, nor could we
discover any other, though Haiiy says its primitive form is
an upright prism with square bases. The most conspicuous
faces of the largest flat crystal on the specimen are shown
in the lower figure, the three angles of incidence that could
be measured were al, bc, cd; the first measuring 142°, the
second 130°, and the third 147°.
There are many minute irregular fragments about the
gangue, and two crystals remarkable for being flattish in
the pyramidal end of the large Quartz crystal, one of
which is reflected three times, or seen at the same time in
three of the faces, which serves as an exainple of the mul-
tiplying quality of faceted subjects, very convenient in
this where the substance is scarce. It is infusible by the
blowpipe, but becomes blackish and opaque.
Since writing the above, I have been presented with a
superb specimen of Quartz, on which are two or three
crystals of this Oxide of Titanium, by my kind patron the
Right Hon. the Earl of Dartmouth, from the same place.
This specimen also has some Adularia about it.
Feb.22809. Publish tu Jax Sonabu Landen.
199
TAB. CCC.
FERRUM. sulphureum.
Sulphuret of Iron, or Iron Pyrites.
Dw. 2. Imitative.
Aone other geological formations, perhaps, that are
least noticed in works of this kind up to the present time,
are those of fruits that are preserved in a Carbonaceous
Pyrites, if I may so term the substance in which the Car-
bon, or remains of the Wood, is more or less incorporated
with the Pyrites which has chiefly taken place of the
Wood, like some parts of the left hand upper Jig. &e.
The present specimens are from the cliffs of Sheppy
Island, near Minster (whence the Sulphate of Barytes,
commonly called Lepastrum—see tabs. 172, 173*).
Many of these fruits fall to pieces from a certain excess
of moisture which acts occasionally on this combination,
by which many valuable specimens are lost from time to
time. I was therefore glad to figure some while in a proper
state.
The upper left hand figure represents a nearly round,
semi-spined fruit with a flattish sulcus on one side. It is
enclosed in a shell which is partly indented inwardly, op-
posite the spines. It is thick and irregular on the outside,
and does not agree with any fruit now known.
The upper middle figure is a five-valved capsule.
The upper right hand figure is not much unlike the cap-
sule of Thea viridis, but is less regular: nor does it agree
* I said, when those figures were done, that they were not found anywhere
else ; but I have since gathered them from the opposite cliffs at Southend,
and have found small specimens at Sydenham in the Croydon canal.
200
with any Euphorbia so well as with Menispermum, Gertn.
é. 70.
In the second row the left hand figure is very different
from any thing I know at present ; as it appears to have had a
fleshy capsule below a calyx of five divisions, and has with-
in it a thinner woody capsule splitting in to five divisions.
The middle figure was not unlike some gourd seeds, but
is now lost by decomposition.
The right hand one represents a flattish woody capsule,
probably having had a fleshy outside.
The third row consists of three figures of a capsule some-
what resembling a hazel nut, partly covered with bubbled
Pyrites. The left hand figure shows the outside; the right
hand one represents the shell broken, as found, with a re-
gular pentagonal seed within, which is shown more di-
stinctly in the middle figure: this is occasionally found
separate from the other part.
The lower line has in the left hand figure a seed or fruit
similar to a nut, but the base has particular marks that do
not agree with it.
The middle figure resembles the longish nutmeg, with
the mace enveloping one side. On one part are protu-
berances which have a white Lime or Chalk upon them.
The right hand figure is a little like a half of a Kentish
cherry with the stone; the outer part or mass is metallic
Pyrites, formed as it were round the stone as from a centre,
showing the peculiar construction of the fleshy part of a
cherry.
Some of the specimens figured are in my own cabinet ;
with the others I have been favoured by Mr. Francis Crow
of Feversham, who has a large and curious collection, of
which I shall have an opportunity of saying more here-
after.
Printed ly Richard Taylor and Co., Shoe Lane.
SYSTEMATICAL INDEX
VOL. ITI.
CLASS I. COMBUSTIBLES. Tab.
var. Metastatic 285. 286
ORDER 1. HOMOGENEOUS. yar copies double
hexaédral pyramid
275. 276
GEN. A. Oxygen Tab. Div. 2. imitative
Spec. 2. aqua var. stalactitical 282
Diu. 1. crystallized — 281 stalact. hard 283
Gen. 7. Carbo coralliform 289. 290
Spec. 4. ferriferum foetid, globular 284
Div. 1. imit. prismatic 269 Sulspec. magnesiata
Div. 2. amorphous 267. 268 Div. 1. crystallized 217
Gen. 4. Silex
ORDER 2, COMPOUND, Spec. 1. quartzum
Div. 1. crystallized 242. 241
s : —_—- — 297
Gen. 1. Bitumen Cale var. jasperine — 219
Spec. 4. succinum 273. 274 Garilaninated ih O08
Div. 2. imitative
CLASS Il. EARTHS. var. septarium = — 207
var. swimming — 298
; var. shell-formed 250
Gen. Pe Argilla var. coralloid — 215
Spec. 2. hydrata var. coralliform 291. 292
Div. 1. crystallized — 243 293
Spec. cyanea Div. 3. amorph — 218
Div. 1. crystallized — 225 Earnest IS 4
Spec. electrica Spec. petuntse
Div. 1. crystallized — 209. 210 Din I: crystallized 257. 211
Spec. ferrifera 212. 213
Dw. 1. amorphous 253. Zoe Div. 2. amorphous 214, 224
Tn tet OO Spec. mesotypus
Gen. 3. Calx Dwv.1. crystallized 265. 266
Spec. 2, phosphata Spec. fulgens _
Div. 1. crystallized 205. 206 Div. 1. crystallized 258. 259
Spec. 4. sulphata — 260
Dw.1. crystallized — 233 Spec. talcum
var. mackled — 233 Div. 3. amorphous — 272
Diz. Z. imitative Spec. steatites
var. spiculated — 234 Div. 3. amorphous — 222
var. fibrous 235. 236 var. indurated 221, 223
Spec. 5. carbonata
Dw. 1. crystallized
VOL. IIt.
Spec.. magnesiatus
Div. 1. imitative
12
202 SYSTEMATICAL INDEX.
Tab.
var. fibrous — 296
var. ligniform — 227
Spec. fragilis
Div. 2. imitative
var. fibrous 228, 229
var. stellated — 230
Gen. 6. Barytes
Spec. 1. sulphate
Div. 1. crystallized 237. 238
Div. 2. imitative — 294
Spec. 2. carbonata, imit. 239
ORDER 2, MIXED.
Gen. 1. Argilla
Spec. marga _ — 240
Gen, 4. Quartzum
Spec. 1. argillaceum 245. 246.247
Spec. talcosum — 231. 232
Spec. lithomarga 251. 252
Spec. argillo-pyritaceum 248
ORDER 3. AGGREGATE,
Talcose breccia — 261
CLASS Ill. METALS.
Gen. 1. Molybdenum
Spec. 1. sulphureum
Div. 1. crystallized — 288
Gen. 6. Zincum
Spec. 1. oxygenizatum
Div. 2. imitative — 201
var. stalactitical — 202
Spec. 5. oxysulphureum
Div. 2. imitative — 249
Gen. 8. Ferrum
Spec. 2. suboxygenizatum
Tab.
Dw. 1. crystallized — 263
Spec. 3. oxygenizatum
Div.3. amorphous — 264
Spec. 5. subsulphureum — 262
Spec. 6. sulphureum
Div, 2. imitative
var. hair-like — 287
var. in form of fruits 300
Gen. 12, Cuprum
Spec. 1, nativum
Div. 2. imitative — 216
Spec. 4. hyperoxygenizatum
Dw.38. amorphous 279. 280
Spec. 13. carbonatum
Dw. 1. crystallized 203. 204
Gen. 14. Argentum
Spec. 7. Muriatum
Div. 1. crystallized — 244
Gen. 15. Plumbum
Spec. 2. oxygenizatum
Div. 1. amorphous — 278
Spec. 5. sulphureum
Div. 1. crystallized — 27]
Spec. 6. sulphatum
Div. 3. amorphous — 270
Spec. arseniatum
Div. 1. crystallized — 295
Gen. 20. Titanium
Spec. 1. oxygenizatum
Dw. 1. crystallized — 299
Spec. 3. oxyferriferum
Dw. S. amorphous — 277
ORDER 2. COMPOUND.
Gen, 1. Ferrum oxygenizatum
Spec. argillaceum
Div. 1. amorphous — 296
ALPHABETICAL INDEX
TO
VOL. III.
Tab. Page.
PNcryNoLine) ee ei, 228 55
sfellated wees yoo. 230 57
undulating dark green 229 56
SeAdamantine;Span a. ccs cdsigce esos 197
abun Clay hie sitesi) eve cvstel tt sioner: 248 95
ma OLALC ME tinier, cyae Gisie eis =) «sce 95
IETEC TIES ase Pea anier tier ete ea Shete 273, 274 145
pura: ClTIN A ea) sete) 2 cele siclelcls 610 « 145
IATMDYC MAMTC Aha 5 5a.) «10s ateyelasteyake 145
Amethyste basaltine.............. 9
PRTAN TA eiatecke pen oyes 2) rel io1 sien) 6 oanere oh as 150
Apatite }
Abatit Gemeiner $ 077001800 9
PEC ONE, MIUMALG S| = 0 212) s1c1s) ereerci oieiois, 0° 87
Argentum muriatum............. 244 87
~ CORMEUME 15 cir cicienoperaiolshete 87
MEP IONAISE i cteiel or 6 5'-. «/=/(s\6 Sedbebde 89
- Wit OMAarge: 2 reicis(s) fo) e10. 5) of: 101
: unie 4 la terre silicieuse, faisant
la moitié du poids, et quelquefois
davantage, et Aun peu de chaux 129
Aspillaceous Schistus ...4.....'.6- 95
Perodua CLUStACCA nA = arcth<\s) 215) 0,c1ervie of 101
= CYANEA 6. eee ee ee ewer eeee 225 49
: Electrica ts a ocklcee BG 209, 210 17. 19
agrees fEPTCTa.. ciele «+ sje cies ot 46 253 103
== hydrate ee. Ase anes Shi 248 85
ASDESCUSs)) COMMMONY © 36.0 idicis Soc icls 6 226 51
dark green woodlike .... 227 55
Aseustite IN! oo... REE BE sen mbane 1)
AZULCIGE CUIVIC: a0.) 5 tess cals s 5
B
Rarytes; catbonata.s. ="... 4 PHOSPHAtay sys bee)» se sels She 6) 205, 206
sulphataeterscre +2). s sere es 233—236
GEES eae ies frome Meera R EE eR mn
@arbo tenriierMic. 2): ayes Bete os 267 —269
Carbon combined with one-eighth or
one-tenth of its weight of Me-
fallichlrOtye Gece sia aerator
Carburerdeitete. cc on cen oc elensets
@haux phosphatée; .. 625 bee. see =
phosphorée....... $5.0 30" Sa
CB AUIS) Sais a4 Hood eR OU uE 248
wees SERIE 505 Rjote se in! oso Sesseoe oa e's 5500
BIOWD Eee oho acco hemeaien 246
COMMON ses. ss 2 Lette) s)spave
peceeer BEAMIC rel cfateys el nisl olele bi=telelelmiale : 245
Potter’s }
Gasees isp peers : 5
Clays, coloured .......... eichatakats 247
. Cledge Nc WeWeme eG cietons aes
Copper, Carbonate of, crystallized blue 203
————$<—__—_—_————green 204
———— Hydrate of ............... 279, 280
Native leaf-like .......... 216
ore, blue calciform........
PETORIGe 100 seh eeievcteis 279, 280
Cuivresazune Geremen eles eis hee ae
carbonaté ae :
oxidé bleu Sac ain
Cuprum carbonatum ............. 203, 204
hyperoxygenizatum ....... 279, 280
TAPLVALIIA 5), sca lone/cbe aly eas wise 216
Cyanit
Ea) Pee aos 225
Page..
145
145. 147
133.0127
97
1.3
153, 154
171,192
177. 179
167
33
169
165
9
On
65—71
145
133—137
133
133
159, 160
29
we
159, 160
5
5
ALPHABETICAL INDEX. 205
Tab. Page,
D
Diisthenetin . 2s wali e iol eetatoretetctets 49
E
Barth, Coloriticones wis aoe eldbetatere 103
— Fuller’s...... BEI a etc RN Fi 231, 232 59
Sa Green Se. i es ae ware elas 143
cms VV AL err eee oils 0; «! od) a. dase ot etattete 60
PYellowere aioe cia iicr sie stale 103
J ESUAS ol eTTERTS) MSs EI oe 37
PICELLUMN EE Caer ces) steieelere fio melee 145
Prde;Gelb 0700's. 3. Ae ca RO 103
F
Heldspatisuse.s - BURRS Neca meter NaN QV DAD O13 | 2.476 1S
214,224,257
elds pathy csysisieciants ices oes 21
Hens. Carburervder oneness ales 133
mineralisé par le Carbon...... ib.
Berrum oxygenizatune.. ) 2 .)0.2.0. 23 264 127
oo argillaceum .. 206 191
suboxygenizatum ......... (263 125
subsulphureum...2 5. .,.. 3- 262 123
Sulphmrewmnas sic «4 syeiersi ste Bib 287. 300 173. 199
Bint) corallifornm. 2 ng Se ee 291 181
Conalloldy eA a ee 215 27
NOMI Meere er etec cea ee ie eee BY/,
Flint-pebbles, variegated .......... 220 39
[SI FLS(Getieze i nce a ene 215 27
POS Stel Miles eee clsise sls pateCe es 3
Bers Rartntc owt cs. sy oe oe 231, 232 5¢
G
Galbzerde cist sy sees bas csi we 103
GVESSUMIE soi fere) severe: 56 sa eter cve wee 145
Graphit } tens
Graphites plambago fie") 14055145 ae
H
| SITU SR NCIGAS I £1 Ce ing ae SPO 281 161
Vali PY Lites ety diac isroiers<-pcteraicic ers 287 173
Hornertz } fan
Hornerz eocwererereec eee eee ec eos ee d
EV ODM SHIVERS ceslosoe sei eels Whe oie o's ib.
Ely drargillites: cessiea cites co 6 sivas 243 65
J
LACIE TE GIA As EOE Giclee Stee Be une 219 37
206 ALPHABETICAL INDEX.
Apc veo BG Aaya Aas au Gouke
JaepIS-MEMCINED perry tre, SS. ARUN Ey, 3S RAR efor othe eal) Fietetedated eyes rte Pao a got! 08 nee 7 we ata Shy, eee at! SSasgVe wont mies — nye
2 SAS ~ 1 e oo ry whe ’ %e ry a 2 a SS! nr S ‘ syae® SS, . : SSS ‘ > ’ > Fe M
alae ee A > "assanahh SS “Peenymat’ Sr Tereg neh Meaaad a Manaah?® Sr Sernaend = a Sanat a "Wesecete ee ws