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Constance, which first presents a thin layer of soft
micaceous sandstone, cemented by clay and lime ;
another of coarse marl and marl-slate, followed
by lirne-slate, alternating with layers of clay. At
the depth of nine or ten feet appears the rock,
which contains the impressions ; and which is, as
usual, a bituminous marlite. The fish are accom-
panied with several insects, and leaves of trees,
some of which belong to warmer climates ; but
far from being so extraordinary as those of Mount
Bolca, which, not to mention more recent dis-
coveries, presented at the time when Saussure
wrote, 1795,

27 kinds of fish of the European seas f
39 ... of the Asiatic.

13 ... of the African.
18 ... of South America.



480 DOMAIN V. CALCAREOUS.



1 1 kinds of fish of North America.
7 , . . of fresh water of the differ-
ent parts of the world.
In all 105.



MODE VIII. ORSTEN.

Name, Some of the Swedish appellations ought to be

Swedish

venerated, as that country has produced such
able writers in natural history, and particularly
in mineralogy; of which science Wallerius,
Cronstedt, and Bergman, must, be esteemed as
the chief founders. The substance now under
view has by some of our mineralogists been
called swinestone, and by the Germans and
French less politely stinkstein, and pierre puante ;
but as the Swedish name has more brevity, and
does not impress a disagreeable idea, it deserves
to be substituted.

Description. Orsten is merely a limestone, which, some-
times from a mixture of bitumen, sometimes
from yet unknown causes, yields a fetid smell,
when worked in the quarry, or in the marble
yards, or even when rubbed with any hard sub-
stance. In a geological point of view, it has
assumed higher consequence, since it was dis-



MODE VIII. ORSTEN,



431



covered by Ramond to form the summit of Mont
Perdu, the highest of the Pyrenees. It is gene-
rally of a black colour; but some specimens
from Derbyshire are even white, or at least
whitish grey. The other tints are chiefly va-
rious greys, with brown and Isabella yellow.

Mr. Kirwan says that the smell is urinous or
alliacious; and that it abounds in the county of
Galway,- in Ireland, where, as fuel is scarce, it is
often employed to heat the rooms, and remains
hot for many hours. In the neighbourhood of
Vesuvius it is found laminar, alternately white
and yellow. It often produces excellent lime.

A g re y Flemish marble, now much used at
Paris, belongs to this kind, and leaves a very
fetid smell in the manufactories. That of the
summit of Mont Perdu is a black marble, im-
pregnated with shells and sand. Ammonites
and camerines, gryphites, pectenites, with mad-
repores, and other zoophytic remains, enter into
the composition of the singular calcareous chain
of the Pyrenees.

Black orsten, from the summit of Mont Perdu.
Grey, with zoophytic remains, from Flanders.
In yellow and white plates, from Vesuvius.
Greyish white, from Derbyshire.



VOL. I.



482 DOMAIN V. CALCAfcBOUS.



MODE IX. GYPSUM,

Characters. Texture, coarse-grained and loose, commonly
with a saline or crystalline appearance.

Hardness, of course gypsic. Fracture, un-
even. Fragments, amorphous, blunt.

Weight, granitose, sometimes only carbonose.

Lustre, glimmering. Opake.

The colour of that of Montmartre is a yellow-
ish brown ; but it is also found of various tints
of grey: and is sometimes so compact as to
resemble coarse limestone.

As gypsum and alabaster consist of the same
peculiar ingredients, though they vary j n the
mode of combination, it may be proper to begin
by considering them on a large scale, and in
one point of view.

In the language of modern chemistry, gypsum
and alabaster are sulphates of lime; the sul-
phuric acid forming about half of their compo-
sition, as the carbonic does in the other cal-
careous rocks: hence the gypsous substances
do not effervesce with nitrous acid, like the va-
rious descriptions of limestone *.

* Fluor very rarely forms rocks ; but with Phosphorite may fcc
-found in the Anomalous division.



MODE IX. GYPSUM.



The distinction between gypsum and alabas-
ter may be regarded as more wide than that be-
tween limestone and marble, though chemical
writers arrange alabaster as merely a compact
gypsum; but the artist, and the antiquary, and
even the common observer, consider alabaster as
a distinct substance.

As limestone may be called a coarse marble,
and when calcined forms lime, so gypsum may
be regarded as a coarse alabaster, which when
calcined forms what is called plaster of Paris,
because the best is made of the gypsum of
Montmartre, in the neighbourhood of that city;
and the alabaster of the moderns, or compact
sulphate of lime, has, like marble, been em-
ployed by the sculptor and the architect, being
of a fine grain, and of a whiteness which has
become proverbial. The tombs of the middle
ages are sometimes of alabaster, yet more gene-
rally, it is believed, of alabastrite; but this has
seldom been examined; for while every parish
has its antiquaries, we have few mineralogists.

Some kinds of gypsum and alabaster, as the
earthy and fibrous, with the crystallised, called
selenite or moon-stone, as it somewhat resembles
the gleam of the moon in water, are found in
veins and nodules, and belong to lithology. In
literary composition, as in painting, the eye



DOMAIN V. CALCAREOUS.



should repose on large masses or divisions -, while
minute and broken lights only distract the at-
tention and the memory. The gypsous rocks
may safely be reduced to two kinds, the coarse
and the compact.

primitive. It was long conceived that gypsum was of
the most recent formation, till a rock of this
kind, undoubtedly primitive, was discovered by
Saussure in the Alps. Dolomieu indeed ex-
presses his wonder, that gypsum has not been
more frequently formed from primitive marble,
as the sulphuric acid might easily be produced
from the decomposition of pyrites. But the re-
marks of Saussure must not be omitted.

" In regard to gypsum, it is found at St.
Gothard, either below Ayrol, as I have said,
1805, or in the Val-Canaria. It is in mass, of
a fine and brilliant grain; it does not effervesce
with acids, and consequently is free from all
calcareous mixture.

" But what is more rare, is to find gypsum
in a schistose form, and mixed with thin layers
of mica : this contains some calcareous parts $
it slightly effervesces.

" I do not think that this gypsous schistus is
a primitive rock, like the calcareous micaceous
gchistus; I believe it to be of modern origin,
and that it originated by deposition in hollows,






MODE IX. GYPSUM. 485

since the formation of the secondary mountains.
The specimens which I possess are of a nature
to justify this idea; their texture is not homo-
genous ; the mica does not appear to have been
united to the gypsum by a simultaneous crystal-
lisation : it is in plates nearly incoherent, which
separate thin layers of an argillaceous sediment.
This mica then seems to have been brought
down and deposited by the waters, rather than
crystallised in them. Nevertheless, as I have
not observed it in its native site, I dare not be
too decided in this opinion." *

This gypsum was observed by Saussure in
passing from Bellinzona to St. Gothard ; but we
are told by Brochant and Jameson that the pri-
mitive gypsum was discovered near Bellinzona;
and they add, that it is in layers between beds of
mica slate; and Jameson says, along with lime-
stone and hornblende slate. I know not their
authority for this assertion; but the objections
of Saussure seemed to Patrin so powerful, that
he virtually denies the existence of primitive
gypsum, by asserting that it is wholly tertiary.
The mixture indeed of mica is of little conse-
quence, as it is found in the most recent sand-
stones ; and even that of felspar, as observed by







DOMAIN V. CALCAREOUS.

Pallas in Siberia, would not now be regarded as
of much importance. The pretended porphy-
ries of Werner should, as already mentioned, be
simply referred to their bases ; for felspar, like
mica, being found in every description of rock,
can no longer be understood to alter the deno-
mination.

This gypsum, supposed primitive, has a schis-
tose structure, and approaches to selenite in
purity. A pure selenite, dividing at right an-
gles, was discovered by Gillet-Laumont, on the
left bank of the Doron, above Moutiers, Mont
Blanc ; and in the same neighbourhood a fine
alabaster, and a red gypsum. This beautiful
snow-white alabaster easily splits in cubes, and
is of a peculiar texture; it sometimes presents
acicular crystals of selenite, with brown spots,
which this excellent mineralogist suspects to be
ferriferous carbonate of lime*; but he did not
express his idea that it was of primitive forma-
tion.

But these are minute exceptions ; and in ge-
neral gypsum and alabaster must be classed
among the Floetz, the planiform, or horizontal
rocks of Werner. Sulphate of lime is commonly

* Chaux carlonatee jaune, ferrifere, as marked in the catalogue
which he gave me of several rock specimens. The precise site is
Salins, near Moutiers, Mont Blanc.



MODE IX. GYPSUM.



a simple rock, like limestone, and sometimes
occurs in large masses and beds ; but sometimes
in layers, alternating with orsten, clay, or sand-
stone. It sometimes contains crystals of quartz,
and in rare instances arragonite and boracite.
It also sometimes presents native sulphur; and
often appears in the neighbourhood of rock salt.
It seldom attains a great height, but forms little
precipices, which, when of the purer kind, are
distinguished by their white lustre. Hollows,
like funnels* are sometimes formed in gypsum,
which Saussure, 1238, ascribes to the rain water,
which, attacking a soft part, remains, and, gra-
dually increasing, melts the surrounding circle.

Gypsum is generally of a whitish yellow, or
yellowish brown cast ; but it also occurs of an
ash grey colour, in which case, as Saussure has
observed, it can only be distinguished from lime-
stone by the nitrous acid producing no effect.

One of the most remarkable gypsous hills in Moutmartre.
Europe is that of Montmartre, near Paris, not
only from its producing the plaster best known
in commerce, but from its peculiar constructure,
and the singular animal remains which have
there been discovered. It is thus described by
the venerable M. Sage, whose chemical mistakes
may be forgiven, in the consideration of the
great services he has rendered to mineralogy,



DOMAIN V. CALCAREOUS.

particularly by the formation of a noble cabinet,
now the public property. The respect due to
his excellent heart, and polite manners, is in-
creased by the regret for his misfortunes, during
JSL revolution which at length destroyed itself, by
ruining even the natural and eternal aristocracy
of talents; so that the members having, as it
were, extinguished the eyes, were of course re-
duced to darkness and perdition.

des S ofption. " The hill of Montmartre is elevated about
forty fathoms above the level of the Seine. The
summit is covered with vegetable earth, under
which is a bed of sand, mixed with rolled flints.
This is seated on layers of marl, of different
colours and thickness: this marl precedes and
accompanies horizontal beds of gypsum.

" The quarries of Montmartre may be consi-
dered as divided into three successive large beds,
or masses.

" The first, called haute-masse by the work-
men, is often more than fifty feet thick; it pre-
sents beds placed one on the other, without any
sensible interruption, although separated : they
are seated on a bed of bluish argil, spotted, about
twelve feet thick. This argil is intermixed with
marl.

" The second part is called pierre franche.
This gypsous mass, which is nearly fourteen



MODE IX. GYPSUM. 489

feet thick, is disposed in contiguous layers, re-
posing on marl.

" The third part, called basse-carrti?*e, pre-
sents a gypsous mass of about fourteen feet,
divided into six beds, separated from one another
by layers of marl. This last part is in the plain,
and is incumbent on limestone.

" I shall not undertake to account for the
formation of the gypsous hill of Montmartre, as
well as those which are contiguous, and form a
chain of eight or ten leagues, in a northern di-
rection. Among the naturalists who have writ-
ten on the quarries of Montmartre, M. Pralon,
and the Chevalier de Lamanon, have, among
others, given excellent lithological descriptions
of this place. The latter affirms, that in this
part of the Isle of France there was a lake of
gypsous water, which gave birth to these quar-
ries.

" The gypsous hills of Montmartre, Belle-
ville, Pantin, and all those of this part of the Isle
of France, are incumbent on quarries of lime-
stone; the gypsous mass only extending to the
level of the soil. The shelly and argillaceous
rock which is found on the summit of the hill of
Montmartre contains white shells, brittle, of the
class of chamites, and screw-shells: these shells
are analogous to those which are found in the



40,0 - DOMAIN V. CALCAREOUS.

river Marne, and in the rivulet of the Gobelins,
as is observed by Lamanon.

" Infiltrations of black martial earth* often
form very elegant dendrites, on white limestone,
mixed with argil. The dissolution of the lime-
stone, infiltrating between the clefts of the gyp-
sous masses, forms stalagmites composed of un-
dulating layers, often distinct by their shades of
brown, yellow, and white. These alabasters vie
in beauty with the best of this kind; but hitherto
they have only been found in thin pieces, often
several feet in length. The limestone which in-
filtrates into the gypsous masses, is the cause
that they almost all effervesce with acids; ex-
cept the plaster-stone with a coarse grain, the
crystals of selenite, and those known by the
name of grignards, a term bestowed on selenite
when it forms regular layers. When these
masses are broken with the hammer, they emit
a strong odour of decomposed liver of sulphur.

" The marl forms beds and masses, more or
less considerable, in the plaster-quarry of Mont-
martre: argil is also found in it in considerable
quantity, and in different states: one is tena-
cious and ductile; the other exfoliates in drying,
and sticks closely to the tongue when tasted.

* Rather manganese.



MODE IX. GYPSUM. 4$ 1

" Heavy spar* is found in the marl at Mont-
martre : it is more abundant in the hill of Belle-
ville, where it is met with in misshapen masses,
greyish, flattened and rounded, at ten or twelve
feet from the surface of the earth.

c< The trunk of a tree agatised, which I found
at Montmartre in 1778, serves to support my
theory on the agatisation of vegetable sub-
stances. See page 168, vol. ii. of my Chemical
analysis of the three kingdoms. This agatised
trunk of a tree was thirty feet long, and nine
inches in diameter; it was rather compressed,
lying horizontally from north to south, and was
at least 100 feet from the summit of the hill, be-
tween the two lowest beds of gypsum, of which
the interior part was crystallised. The inter-
stices of this agatised wood are ornamented with
little regular rock crystals, of various colours.
A part of this wood is brown and compact : this
colour is owing to iron and oil, principles of the
woody substance. I have inquired, since then,
if any agatised wood had been found at Mont-
martre, and I was assured that it had not.

" The shelly sandstone which is found at
Montmartre, seems of the same date with the
agatised wood : this sandstone contains white

* Strontian,



492



DOMAIN V. CALCAREOUS.



calcareous muscles and clams. For the most
part, it only presents the impression of these
shells. In regard to the sand and flint, which
are found in the u'pper layers of the hill of
Montmartre, they have no peculiar character,
and do not appear to differ from those found on
the sides of rivers ; but in the masses of gypsum
is found whitish silex, striped, and formed in
this quarry, like the masses of shelly sandstone.
" In the hill of Belleville, two feet from the soil,
are found black flints, in beds formed in irregu-
lar heaps; they lie in a kind of marl, which
reposes on a bed of gypsum of ten or twelve
feet, the layers, which are of different thickness,
being intermixed with marl : this layer of gyp-
sum lies on a considerable bed of green argil,
under which the gypsum is again found *.
Bones. " The bones which are discovered in the
gypsum, have undergone no other alteration
than that effected by time: the greater part
have a yellowish tinge. M. de Joubert has ob-
served, that these bones are always surrounded
with a kind of marl, which he regards as being
produced by the decomposition of the soft parts
of animals. In the cabinet of that naturalist

* This green clay corresponds with that of the river Marne^
which is green. It contains iron. See Vauquelin's analysis.






MODE IX. GYPSUM. 4QS

there are icthyolites; the impression of the fish
being compressed, as in schistus: nor are the
fish solid, as in limestone.

" M. d' Arcet. possesses an ornitholite, or pe-
trified bird, which he found, in 1781, twenty
fathoms below the summit of Montmartre *.

" It has not yet been decided to what species
of animals the bones found in gypsum belong.
If these bones are neither agatised, nor pene-
trated with gypsum, it is because the absorbent
earth, which forms their base, is found to be
combined with phosphoric acid, and a fat sub-
stance (; consequently the selenitic water has
not been able to decompose these bones.

" The brown hepaltic iron ore, solid, in an
irregular mass, which is found dispersed in some
places in the hill of Montmartre, seems to be
the product of decomposed pyrites.

" The calcareous and gypsous ludi, in a
spheroidal mass, flattened, called by the work-
men miches de quatorze sous, are found to the
east of Montmartre, near Clignancourt, in a bed
of marl, from twelve to fifteen feet below the
summit of the hill. Among the ludi of this
kind, which are in the cabinet of the royal
School of Mines, there is a spheroidal mass,

* It seems to be a water- rail.

t The acidum pingue is a favourite teet of M. Sage.



494 DOMAIN V. CALCAREOUS.

flat, of two feet diameter, and seven inches
thick; all the exterior crust is calcareous, gra-
nular, greyish, and a little argillaceous : it is an
inch and a half thick. The interior of this Indus
is filled with gypsous prisms, greyish, penta-
gonal and hexagonal, with interstices between
them. These prisms are two or three inches in
height, and one in diameter; their surface is
strewed with small brilliant crystals.

" The farinaceous gypsum, or white gypsous
earth, is sometimes found in the form of guhr,
- but the crystalline gypsum forms considerable
beds: they are often intermixed with grignards,
or crystals of selenite, forming continued layers.
Lenticular seleuite is found in the marl : these
crystals, grouped in different ways, have been
precipitated from the aqueous fluid which held
them in solution; the marl, which has after-
wards settled, has encrusted, gurrounded, and
protected them. They are found in great quan-
tities at the foot of Montmartre, towards M ou*
ceaux.

<c Basaltic selenite, or in hexahedral prisms,
with trihedral summits, alternate, with a curved
surface, is found in the marl, near the summit
of the hill of Belleville.

" Prismatic decahedral selenite, produced by
the elongated octahedron, truncated near its



MODE IX. GYPSUM.



basis, is very scarce at Montmartre;' but is
common in the hill of St. Germain-en- Lay e,
where it is found in grouped crystals, spread in
a red veined clay, which precedes the beds of
limestone, found towards the summit of the hill.

" At Montmartre I also found striped sele-
nite, in small layers of two or three lines in
thickness/ 1 *

One of the most singular discoveries made at
Montmartre was a horse-shoe, partly corroded
by age; but more than the half remains with
the holes very distinct. It is said to have been
found at a great depth in the solid mass, and
had most probably dropped into a reft, After-
wards filled by stalactitic matter, a common ap*
pearance in gypsous regions.

Fossile bones did not attract so much curi-
osity when they were carelessly examined, and
supposed to belong to known animals. But the
singular discovery in South America of the en-
tire skeleton of an animal larger than the ele-
phant, and of quite a different genus, and now
totally extinct f, led to more minute investi-
gations and comparisons, till it was at length

Sage, Supplement & la Description Methodique du Cabinet
de 1'Ecole Royale des Mines. Paris 1787, 8vo. p. 124.

f See the print, Faujas, Essai de geologie, from the large plates
engraved by order of the King of Spain,



496 DOMAIN r. CALCAREOUS.

discovered by microscopic eyes, that even the
insects found in amber are not of the European
kinds, but belong to distant regions. In the
comparative anatomy of fossile bones, the cele-
brated Cuvier greatly distinguished himself, and
by patience and research has nearly completed
three skeletons of those found at Montmartre.
For they belong to three kinds of animals, of the
same genus, but of very different stature ; one
only attaining the size of a hare, the second of
a hog, while the third reaches the size of the
horse. Those animals approached the nature of
the rhinoceros, the hog, and the American ta-
pir, but were more nearly allied to the latter.
Being herbivorous, as appears from the teeth,
easily distinguishable from those of carnivorous
animals, their bones seem to have been rolled
down by the river to the spot where they are
now found.

shells. It might be imagined, that there is a kind of
artful malice, if the expression may be pardoned,
in the bosom of the goddess Nature, which
allows human theory to sport for some time,
and then brings out her stores for its destruction.
It was long conceived, that fossile shells were
confined to limestone, and fossile bones to gyp-
sum, till very lately most of the sea-shells, found
in the highest state of preservation in a bed of



MODE IX. GYPSUM.

sand at Grignon, about four leagues beyond
Versailles, have also been discovered in the gyp-
sum of Montmartre. Most of the shells found
at Grignon, some of which retain their most de-
licate spines, and even their colours, are known,
now to belong to the South Sea, a portion of the
Grand Ocean falsely called the Pacific; and
but few to the Atlantic, or even the Mediter-
ranean.

The various beautiful kinds of selenite, or
crystallised gypsum, found at Montmartre, be-
long to lithology. The curious kind called ve-
getable selenite, from its resemblance to vegeta-
tion, seems confined to Derbyshire.

Aspect 1. Common gypsum, from Montmartre.

The same, with selenite, often elegantly inter-
spersed with farinaceous gypsum.

The same, with blue variegated clay.

The same, in small layers of marl, &c. forming,
as it were, a Montmartre in miniature.

The same, with imbedded ossilites, or bones of
quadrupeds and birds.

The same, with various sea-shells ; a recent and
curious discovery. Brongniart says that some of
the marl beds contain cardites, venerites or dion-
ites, tellenites, cerites or screws (turbinites), and

VOL, i. 2 K



DOMAIN V. CALCAREOUS.

even bones of fish, and trunks of the palm-tree.
Small pieces of iron-stone also appear, particu-
larly on that side where the gypsum once bore a
prismatic form, now destroyed by the progress of
the quarriers, and which probably arose from the
influence of that metal.

Aspect 2. Grey gypsum, from Mount Cenis.
The same, from Germany.



MODE X. ALABASTER.

Characters. Texture, compact, generally saline, but fine-
grained ; sometimes fibrous, even in large masses.

Hardness, gypsic. Fracture, even, sometimes
scaly. Fragments, amorphous, rather blunt.

Weight, carbonose, sometimes granitose.

Lustre, glimmering. Sometimes translucent,
even in pretty thick pieces ; often only on the
edges.

The colour is generally of the purest white,
sometimes slightly veined with grey : but when
stalactitic, it may be veined with yellow and
brown, by ferruginous infiltrations. In small
veins it may assume a rose colour, as at the Old
Passage, near Bristol, where it is however too



MODE X. ALABASTER. 499

soft to be polished. It may also, like that near
Nottingham, appear blue when held between
the eye and the light.

It is now proper to pass to the consideration
of that fine compact gypsum called alabaster.



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