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kind of marble or jasper, found in Kasgar*.
" The king of Katay buys it at a great price ; and
what he leaves, the merchants sell to others at
exceeding great rates. Of it they make vessels,
ornaments for garments, and girdles, with other
toys, whereon they engrave leaves, flowers, and
other figures. The Chinese call it TiLshe-\. There
are two kinds; one more precious, like thick
flints, which are found by diving in the river
Kotan, not far from the City Royal : the other
meaner sort is digged out of quarries, and sawed
into slabs above two ells in breadth. The hill
where they are dug, called Konsanghi Kasho,

* Green's Voyages, iv. 645.

f In the original Tusce, a mistake, no doubt, for Yu-she, the
word used by Du Halde. There seems great reason to infer, that
the pocula murhina of the ancients were of this substance.



MODE VII. ARGILLACEOUS INTRITE. 281

r the stony mountain, is twenty stages from the
same city. This marble is so hard, that they
must soften it with fire to get it out of the quarry.
The king farms it every year to some merchant,
who carries provisions for the workmen for that
space of time."

This precious substance, if we judge from its
hardness, cannot be the present article; but is
probably that beautiful jad (though perhaps fu-
ture discoveries may impose a different iiame),
which is brought from Tibet and China in the
form of small basins, sword-handles, c. It some-
what resembles chalcedony, but is far more pond-
erous. The chemical analysis and proper classi-
fication of this singular substance remain among
the desiderata of mineralogy, though specimens be
not uncommon in various great collections.



MODE VII. ARGILLACEOUS INTRITE.

The argillaceous intrites and glutenites are of
prodigious extent and importance. The chief
intrite, commonly called clay porphyry, as con-
sisting of crystals of felspar in a base of clay, is
sometimes a principal material in vast chains of
mountains. The argillaceous glutenites, called



DOMAIN III. ARGILLACEOUS.



grauwack, sand-stone, &c. form extensive re*
gions of the earth.

STRUCTURE I. ARGILLACEOUS INTRITE, WITH CRYSTALS
OF FELSPAR.

porphyry. This substance forms large mountains in Lower
Hungary, and sometimes contains chalcedonies,
carnelians, amethysts, or zeolite*. According to
Werner it is either primary or secondary ; the
latter containing branches and roots, and even en-
tire trees, petrified ; as, for example, near Chem-
nitz in Saxony. The primitive argillaceous por-
phyry has commonly a red base, but differing
much in hardness from genuine porphyry.

This intrite forms a considerable portion of the
Andes, and of the metallic mountains of New
Spain. The saxum metalliferum of Baron Born
is also a clay porphyry, but is justly classed
among the Decomposed Rocks. Great confusion
has arisen, as has already been observed, from
arranging the porphyries in one family ; while they
ought to be classed as intrites, according to their
various bases.

Clay porphyry, from the metallic mountains of
New Spain.

* Kirwan Geol. Ess, 206, 207.



MODE VIII. ARGILLACEOUS GLUTENITE.

The same, from Lower Hungary.

The same, from Pentland hills, near Edinburgh.

The same, with petrified wood, from Saxony.

STRUCTURE II. WITH VARIOUS CRYSTALS.

Argillaceous intrites are also found with inlaid
crystals of quartz, calcareous spar, zeolite, and
other substances.



MODE VIII. ARGILLACEOUS GLUTEN1TE.

There is scarcely any bricia which belongs to
this Domain. Born indeed mentions a clay
bricia, consisting of fragments of his metallic
rock, joined by an argillaceous cement*. Frag-
ments of clay slate are also found united by a
spongy argillaceous tufa, an evident decompo-
sition of the substance by water. But these in-
stances are rare, and of little moment.

That kind of glutenite called pudding-stone
also falls rarely under this Domain, the cement
being commonly siderous or siliceous.

The argillaceous glutenites may as usual be
divided into the large and small grained. Even
the grauwack of the Germans, the most gene-

* Raab, i. 414.



284



DOMAIN III. ARGILLACEOUS.



rally diffused of this kind, may rather pretend to
the latter denomination, as where the pebbles
are large, they are commonly interspersed at
considerable distances.



STRUCTURE I.



LARGE-GRAINED ARGILLACEOUS GLU-
TENITE.



luarrects. The most remarkable rock of this kind is that
described by Saussure, who discovered it unex-
pectedly in a vertical situation, in the Alps of

Vaiorsine. Valorsine. In 1776, and afterwards in 1784, he
visited the mountain of Balme, which gives source
. to the river Arve, and made the following curious
observations, which chiefly contributed to lead to
his system of refoulements or subversions, an idea
which unhappily he does not explain at full length,
but implying that the rocks now found vertical
were formed in a horizontal position, and were
afterwards elevated by some cause operating in a
contrary direction from beneath or above*.

" The base of this mountain is a genuine grey
granite, with grains of a middling size, and of a
structure nothing remarkable. But above these
granites are found schistose rocks of quartz, mica,
and felspar ; an intermediate kind of rock between

* The French of the Swiss writers in general is impure, and
sometimes requires a particular dictionary, as they think in Swiss or
German.



MODE VIII. ARGILLACEOUS GLUTENITE. 285

veined granite and common mica slate. Their
beds run from north to south, as does the valley
of Valorsine, and form an angle of 60 degrees
with the horizon, leaning to the west, against the
valley. These rocks are continued in the same
situation for more than half an hour's walk ; they
are lost sight of under the verdure which covers a
small plain, situated in the midst of woods, and
which is called le plan des Ceblancs.

" From thence, ascending obliquely on the south
side, great blocks of grey schistus, or of a violet
red, are found, sometimes even of a decided violet
colour, which contain a great quantity of foreign
pebbles, some angular, others rounded, and of
different sizes, from a grain of sand to the size of
the head. I was desirous of seeing these pud-
ding-stones in their native place. I went straight
up, to get to it ; but there, how was I surprised
to find their beds vertical !

:i This surprise will easily be conceived, when
it is considered that it is impossible that these
pudding-stones could have been formed in this
position.

c That particles of the greatest tenuity, sus-
pended in a liquid, may be agglutinated among
themselves, and form vertical beds, is what we
easily conceive, and of which we have proof in
the instances of alabaster, agates, and even in



8(> DOMAIN III. ARGILLACEOUS,

artificial crystallisations : but that a ready-formed
stone, as large as the head, should stop in the
middle of a vertical wall, and have waited there,
till small particles of stone should come and sur-
round it, cement it, and fix it in that place, is a
supposition at once absurd and impossible. It
must then be considered as a thing demonstrated,
that these pudding-stones have been formed in a
horizontal position, or nearly so, and elevated
after their induration. What is the cause that
has elevated them? It is what, as yet, we are
ignorant of; but it is already one step, and that
an important one, to have found, among the pro-
digious quantity of vertical beds which are met
with in our Alps, some, which we are very cer-
tain have been formed in a horizontal position.

" Even the nature of the substance which en-
velopes the pebbles of these pudding-stones, ren-
ders this fact more curious, and more decisive.
For if it was a misshaped and coarse paste, it
might be thought that these pebbles, and the paste
which cements them, were thrown pell-mell into
some vertical crevices, where the liquid part hard-
ened by drying. But on the contrary, the tissue
of this paste is of admirable regularity and fine-
ness ; it is a schistus, whose elementary laminae
are extremely thin, mixed with mica, and perfectly
parallel to the planes which divide the beds of the



MODE VIII. ARGILLACEOUS GLUTENITE. 287

stone. Those beds themselves are very regular,
well connected, and of different thickness, from
half an inch to several feet. Those which are thin
contain few, and sometimes no foreign pebbles ;
and some alternations are observed of thin beds
without pebbles, and thick ones which contain
thfem. The colour of the base of this schistus
varies considerably; it is grey, greenish, most
often violet, or reddish ; some is also found
marbled with these different colours. These beds
are in a direction from north to south, exactly like
those of granitoid rocks, which are under them ;
but the inclination of the schistus in much greater,
its beds are often nearly vertical ; and when they
are not, they rise some degrees on the same side as
the rocks I have just mentioned, that is, towards
the west.

" The pebbles buried in this schistus are, as I
have said, <)f different sizes, from a grain of sand
to six or seven inches diameter ; they all belong
to that class of rocks which I call primitive ; yet
I have not observed massive granite ; only laminar
granite, laminar rocks, blended with quartz and
mica; even fragments of pure quartz, but posi-
tively no schistus purely argillaceous, nor any
lime-stone ; nothing which effervesces with aqua-
fortis, and even the paste which contains these
stones does not. Their form differs; some -are



288 DOMAIN III. ARGILLACEOUS*

rounded, and have evidently lost their angles by
friction ; others have all their angles sharp ; some
even have that rhomboidal form that those kind of
rocks so often affect. In those parts of the rock
where these pebbles are imbedded in great quan-
tities, the elements of the schistus have not had
room to arrange themselves, and form parallel
laminas ; but every where, where the stones leave
between them sensible intervals, the laminse re-
appear, and are constantly parallel, both with one
another and with the planes which divide the beds.
" The mass of these schistose pudding-stones
constitutes a thickness of near 1 00 fathoms in the
mountain, reckoning from east to west across the
beds ; and I traced it in the direction of its length,
for more than a league : it cannot be traced far-
ther, because the beds hide themselves, and are
buried under the earth.

" Above these pudding-stones, to the south,
slate is found, of which the beds are rather less
inclined, and the direction a little different ; the
tend some degrees more to the east, like those o
Col de Balme, but they lean to the same side, as
those among the beds of pudding-stones, which
are not quite vertical : they lie towards the west.
" In continuing; to ascend, thin beds of sand-
stone are found above the slates, which have the
same situation and inclination with these last.







MODE VIII. ARGILLACEOUS GLUTENITE. 289

On these sand-stones are other slates ; then thin
layers of bluish calcareous rocks, mixed with
mica ; then the same stone with very little mica ;
and then again the same in thicker beds without
any mixture of mica.

" Then the same succession recommences : first
sand-stone, mixed with mica and quartz ; on these
lime-stones, in thin layers, mixed with mica and
quartz; then the same, in thin layers, almost
without any mica ; and lastly the same, in thicker
layers, entirely exempt from mica.

" Here the vegetable earth almost entirely co-
vers the summits of the layers ; only here and
there, two or three feet above the grass-plats,
eminences of calcareous layers, nearly vertical,
are perceived. These eminences, arranged in pa-
rallel lines, as if they had been so placed by art,
afford an appearance altogether singular.

" From thence to the highest limit of Col de
Balme, you walk entirely on summits of slate,
nearly vertical, which sometimes degenerate into
laminar sand-stone, mixed with mica; and such
is the nature of the peak, on which is placed the
high stone ; bearing on one side the arms of Sa-
voy, and on the other those of Valais, with the
date of 1738. These latter layers turn more di-
rectly from north to south, and approach nearer
to the vertical position, than the slates, which are

VOL. I. H



290 DOMA1M III. ARGILLACEOUS.

above the pudding-stones ; but their inclination is
always towards the west.

" The entire mass of this mountain, elevated
1181 fathoms above the sea, has then been raised
by the same revolution, that is, this revolution
has given a vertical position to the whole mass of
these beds, originally formed in a horizontal one.
For all these layers having very nearly the same
position as those pudding-stones, they being im-
bedded in the midst of the mountain, and having
undoubtedly undergone this change, it is impos-
sible not to believe that the position of all the
parts of the mountain has originally been the
same, and that this position has experienced the
same change by the same cause. "*

Such is the account given by this great observer
of the most remarkable argillaceous glutenite
which has yet been discovered ; and it is worthy
observation, that this instance, among many
others, shows the error of the division, proposed
by some, of bricias and pudding-stones ; for here
both angular fragments and round pebbles are
found in the same mass.
Bnciaof A great part of the north of Scotland, and

Scotland.

almost the whole of the Orkneys, consist of an
argillaceous sand-stone, with interspersed masses

* Sauss. vol. iii. 138. 8ro,



MODE VIII. ARGILLACEOUS GLUTENITE, Q<) \

of bricia, consisting of granite and other primitive
rocks. But this bricia seems to be united by a
siliceous cement : if the fragments be sometimes
joined by the argillaceous sand-stone, it may be
classed under this division.

The substance called grauwack by the Germans
sometimes contains large fragments of clay slate,
and large pebbles of quartz ; but as its grain in
general is rather that of a sand-stone, it will be
considered under the next structure. The Ger-
man name is not only barbarous in itself, but im-
plies grey wacken ; while wacken is a rock essen-
tially different. Mr. Kir wan says that it is the
grh-gris, or grey sand- stone, of the French, a
name very applicable ; and it seems also to be the
grison of some French topographers. The latter
appellation might be adopted as at once express-
ive and sonorous ; but as other important rocks
have received appellations from the illustrious
founders of mineralogy, the term Bergmanite .may
perhaps be preferable.



STRUCTURE JI. SMALL-GRAINED ARGILLACEOUS GLU-
TENITE.

The most celebrated rock of this denomination Grison, or

Bergmanite.

is the Grison, or Bergmanite, just mentioned,
being composed of grains of sand, various in size,
sometimes even kernels of quartz; which, with

u 2



'.\ ( ' 4 i DOMAIN 111. ARGILLACEOUS.

occasional bits of hard clay slate, and sometime
of schistose keralite, arc imbedded in an argilla-
ceous cement, of the nature of common grey clay
slate. When the particles are very fine, it as-
sumes the slaty structure, and forms the grauwack
slate of the Germans. It is the chief of Werner's
transitive rocks, nearly approaching to the primi-
tive ; while at the same time it sometimes con-
tains shells, and other petrifactions of the se-
condary.

This important rock was formerly considered
as being almost peculiar to the Ilartz, where it
contains the richest mines ; but as the science has
advanced, it has been observed in many other
countries. The slaty grison, or Bcrgmanite, has
been confounded with a clay slate; and we mv
obliged to Mr. Jameson for the following dis-
tinctions : 1. It is commonly of a bluish, ash, or
smoke grey, and rarely presents the greenish or
light yellowish grey colour of primitive clay slate.
2. Its lustre is sometimes glimmering from specks
of mica, but it never shows the silky lustre of clay
slate. 3. It never presents siderite nor garnets,
4. It alternates w ith massive grauwack. But is
not the chief distinction its aspect of a sand-stone,
which has led to the trivial French name of grks-
gris, and the English rubble-stone, which may
imply that it was formed of rubbed fragments, or



MODE VIII. ARGILLACEOUS GLUTENITE.

of the rubbish of other rocks? The fractui
cjJso different; and three specimens of various
fineness, which I received from Daubuisson at.
Paris, could never be confounded with clay slate.

" This rock is uncommonly productive of me-
tals, not only in beds but also in veins, which
latter are frequently of great magnitude. Thus
almost the whole of the mines in the Hartz are
situated in greywack. These mines afford prin-
cipally argentiferous lead-glance, which is usually
accompanied with blend, fahl ore, black silver
ore, and copper pyrites. A more particular ex-
amination discloses several distinct venigenous
formations that traverse the mountains of the
Hartz. The greywack of the Saxon Erzgebirge,
of the Rhine at Rheinbreidenbach, Andernach,
&c., of Leogang in Salzburg, is rich in ores, par-
ticularly those of lead and copper. At Voros-
patak and Facebay, in Transylvania, the greywack
is traversed by numerous small veins of gold.

" The whole of the important lead-glance form-
ation of Leadhills and Wanlockhead is situated in
greywack.

" It was for a long time supposed that this rock
was peculiar to the Hartz, where it occurs in great
quantity: later investigations however have shown,
that it is widely and abundantly distributed. Be-
sides the Hartz, it occurs also in the Electorate



294 DOMAIN m. ARGILLACEOUS.

of Saxony, on the Rhine, as at Ehrenbreitstein
and Oppenheim, Bohemia, Silesia, Moravia, Salz-
burg, Switzerland, Pyrenees, Transylvania, Tus-
cany, France, and Portugal ; nearly all the moun-
tains in Scotland, that lie to the north of the Frith
of Forth, are principally composed of this rock :
and many, if not the \vhole, of the mountains in
Cumberland appear to be of the same nature."*
Argillaceous Another remarkable rock, belonging to this di-

sand-stone.

vision, is the argillaceous sand-stone, which com-
poses the Orkneys, and part of the north of Scot-
land. It is commonly of a brown colour, and
more or less indurated by iron, whence it some-
times decomposes in fantastic forms. The south-
eastern part of the Mainland of Shetland also con-
sists of this sand-stone, which has unexpectedly
been found to be metalliferous. A copper mine
was opened near Sandlodge, the upper rock being
sand-stone, while, at the depth of 150 feet, was
found a rock of keralite, traversed by many veins
of brown quartz. The copper .was imbedded in
an iron ore, in veins between the sand-stone and
the keralite. " The iron ores here found are,
1, Dark-brown, fibrous, and mamellated hema-
tites. 2. Columnar bog-iron ore. 3. Micaceous

* Jameson, Geognosy 151. In his Dumfries, p. Q2, he says
the craigs near that town consist of fragments of syenite and grau-
wack, the bricia being cemented by ferruginous clay.



M&DE VIH. ARGILLACEOUS GLUTENITE. 295

iron ore. 4. Iron ochre, of a brown colour. 5.
Stalactitic iron ore, colour dark brown. 6. Earthy
matter, much charged with iron, seemingly arising
from the debris of other ores. The copper ores
are, 1 . Friable and amorphous carbonate of cop-
per, colour rich green. 2. Beautiful carbonate of
an emerald green, crystallised in capillary fibres
of a silky lustre, diverging in radii from a centre :
this species is found imbedded in iron ore. 3,
Sulphuret of copper, disseminated through felspar
in some places, and in others, in great masses, in
iron ore. The rich carbonates were found near
the bottom of the mine."*

This sand-stone also often occurs in a schistose
form, when it is called sand-stone flag.

The Wernerians have confounded the sand-
stones, as they have the porphyries, while they
ought to be carefully distinguished according to
the nature of the cement. The whet-stones and * Whet-stone,

&c.

filtering-stones are often argillaceous glutenites,
as is the important division Cos of Wallerius, Lin-
naeus, and other writers in Latin. Some whet-
stones are curiously spotted, commonly with dark
specks on a light ground f. According to Wal-

* Dr. Trail's Mineralogy of Shetland, in Neil's Tour, p. 170.

f Da Costa, 120, &c. mentions the whet-stone of Derbyshire
as of a lax texture, easily pervaded by water, as most clays are.
The grind-stone of Gateshead, Durham, also possesses this quality.






DOMAIN III. ARGILLACEOUS.

lerius, the filtering-stone from the Canary Islands,
and New Spain, consists of angular particles of
quartz, united without any cement ; but the pure
siliceous sand-stone seems the most uncommon.

Gmelin, in the last edition of Linnaeus, has
included Cos among the Lapides arenarii, which
he rightly arranges in three divisions, with a sili-
ceous, calcareous, and argillaceous cement. Of
the latter he particularises that of Fahlun, in Swe-
den, where it forms the bottom of the copper-
mine ; and that found in many countries, where it
is used for slates. The sand-stone of Derbyshire
is chiefly argillaceous, as is probably the flag-stone
of Oxfordshire. To this class also generally be-
longs the sand-stone found in coal-mines, which
sometimes bears vegetable impressions. Some
sand-stones present layers of variegated colours,
the cement being probably argillaceous, tinctured
with iron in various proportions *.

Saussure mentions the following :

Argillaceous sand-stone, in vertical beds, or
arrects, which he says cannot be the effect of a

* Mr. Jameson says (Dumf. 166) that the cliffs of Hawthorn-
den are of red sand-stone : argillaceous or siderous ? The same
question may be applied to the chain of mountains behind our set-
tlements in Notasia, or New Holland, which have been found im-
passable. Voy. de Peron, Paris 1808, i. 3Q3. From the sea to tha,t
chain the radical rock is siliceous sand-stone.






MODE VIII. ARGILLACEOUS GLUTENITE. 297

simple subsidence, but implies a " refoulcment en
sens contraire, which has broken and raised beds
originally horizontal." 1 166.

A fine argillaceous sand-stone, speckled with
mica. 1442.

The beautiful pierre de Moravie seems of this
kind : it is white, with purple lines*.

* Gallitzen, Recueil des Noms des Mineraux, Brunswick 1801,
4to, Born mentions a sand-stone of Siberia, containing nodules of
malachite. In Thuringia a sand-stone is found which is worked ns
an ore of copper; and it also contains silver, cobalt, arid lead,
Brongn. ii. 224.




/uy-tfct






DOMAIN IV.

TALCOUS.



MAGNESIA.

THIS earth seems first to have been dis-
covered, or at least sold as a remedy, by
an ecclesiastic at Rome about the begin-
ning of the eighteenth century. Under
the name of magnesia alba, it was proposed
as a universal medicine, while it could do
little more than supply the place of the






DOMAIN IV. TALCOUS. 99

Lemnian earth, and other boles. As Theo-
phrastus, however, in describing the stone
called magnetes, says it may be turned on
a lathe, and has a silvery appearance, Dr.
Kidd agrees with Hill, that the ancient
Greeks called the load-stone heraclea, but
the more modern magnetes; and Pliny's
description of the stone brought from Mag-
nesia, in Asia, seems to belong to a talcous
substance*.

Hoffman, Black, and Bergman, contri-
buted to establish the difference between
magnesia and lime. It seems originally to
have been prepared from nitre; but sea-
water contains the sulphate of magnesia,
a salt composed of this earth and sulphuric
acid; and which is also found in many
springs, particularly at Epsom, whence it
was called Epsom salt.

Magnesian or talcous earth is infusible
in the strongest heat. It does not form






* Kidd, i. Ql. It is singular that the modern Italians have also
a calamita bianca, or white magnet, which is described as fibrous,
and probably belongs to the same description. Ferber, Italy 88,
says it is a white hardened bolus, striated like asbestos.



300



DOMAIN IV. TALCOUfe.






phosphorets, like the three other alkaline
earths, lime, barytes, and strontia.

In talc it sometimes amounts to one half
of the composition ; but in the other sub-
stances, such as steatites and serpentines,
it is only from twenty to forty; but its
power is so great as sensibly to alter the
appearance and qualities of the stone. The
chrysolite or peridot of the French, con-
taining about one half magnesia, belongs to
this division; and is remarkable as the only



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