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This substance, like alabastrite, is regarded as
being a sinter, or deposition ; but from gypsous
rocks. Hence it is commonly found in small
layers, and being rather soft, is used for little
statues and ornaments. Yet Gmelin, who has
ranked it under gypsum, assures us that it forms sites.
entire mountains, or at least very large strata, in
Thuringia and Siberia*; but he probably con-
founds it with alabastrite, the ancient or cal-
careous alabaster. If, as Mr. Kirwan asserts,
even mountains of gypsum are foundf, alabaster
may fill prodigious caverns. While Werner and
his disciples are perhaps too minute in lithology
and metallogy, they are in petralogy far too
theoretic and general : but if gypsum be found,
as they assert, in rocks distinguishable by their
white colour, they must belong to alabaster.
In fact, what has been styled primitive gypsum,
particularly the cubic of Salins, Mont Blanc, is
the purest alabaster; and naturalists ought to
attend to common distinctions, and the purposes

* Linn. 118.

f Geological Essays, 238.

2 K 2



500 DOMAIN V. CALCAREOUS.

of art and utility, else the sapphire and the ruby
might be confounded with corindon. It may
seem particularly doubtful whether the kind
called anydrous by the French mineralogists,
because it contains no water of crystallisation,
can properly be regarded as a sinter, or depo-
sition from other beds ; particularly that of Vul-
pino, which contains silex, and has been quar-
ried for many ages. If gypsous alabaster form
beds, which alternate with orsten and limestone,
it cannot be regarded as the mere production of
other rocks.

Mr. Jameson, who deserves to be mentioned
with respect, upon account of his assiduous ser-
vices to mineralogy, in treating compact gyp-
sum, observes, that " it occurs almost always
ash grey, passing into smoke grey, also yellow-
ish grey;" and closes thus, " It is employed in
architecture and sculpture, under the name ala-
baster." Nothing surely can be more contra-
dictory to the common sense of mankind, except
Mr. Werner's new and elegant appellation of
White-stone, thus introduced to his audience by
a German Professor, " White-stone is always
grey." The ingenious and intelligent Brard,
though a mere youth, gives a more rational ac-
count.

" Gypsous alabaster does not effervesce in



MODE X. ALABASTER.



nitrous acid ; it loses its transparency, its lustre,
and solidity, when exposed to fire; that is to
say, that it changes into plaster.

" It is so soft as to be marked with the nail,
and yet it takes a pretty fine polish ; but it is
true that the least friction will destroy it.

" It is never decked with lively colours;
milk-white is its colour by excellence.

<c Its transparency is sensible, even through
thick plates.

" In short, its fracture or internal aspect va-
ries much ; sometimes it presents a crystalline
and bright tissue, sometimes only a laminar con-
texture, or at other times only a dull and com-
pact surface.

" As gypsous alabaster is much oftener white
than calcareous alabaster, it is to that kind that
the old proverb should be applied of white as
alabaster."*

He informs us that the statues of the superb Monuments.
mausoleum of the Constable Lesdiguieres, in the
cathedral of Gap, are of gypsous alabaster, from
Boscadon, near Ernbrun, in the department of
the Upper Alps. It is probable that those in
the English cathedrals, generally executed by
foreign artists, are of Italian alabaster. The



P.



502 DOMAIN V. CALCAREOUS.

alabaster of the department of Mont Blanc, of
the most beautiful white, sometimes veined with
grey, and receiving an exquisite polish, is much
employed at Grenoble, the Gratianopolis of an-
tiquity, and the chosen seat of Venus and
Apollo.

Anydrous. The alabaster called anydrous is of several
colours, white, rose, grey, and even blue, which
is called celestine, a name now strictly belong-
ing to a kind of strontian. The white anydrous
kind is also found at Vizil, near Grenoble ; and
was used by the Romans, as appears from the
beautiful mile-stone, or rather column, at Thin,
on the banks of the Rhone, which is six feet
high, and erected in the time of Aurelian*.

Anydrous alabaster, mixed with a considera-
ble quantity of silex, forms the bardiglio of the
Italians, found near Vulpino, fifteen leagues
from Milan, and employed in making columns,
tables, and vases. It properly belongs to the
Diamictonic Domain, where it is more particu-
larly described.

White alabaster, from Derbyshire.

With a blue transparency, from Notting-
ham.

White alabaster, from the lower Pyrenees.

* Ib. 473.



MODE X. ALABASTER*

Yellowish white alabaster, from Lagny, about
twenty miles from Paris, where it is used for
columns and vases. It is translucent, and full of
little cracks, which however do not affect its
solidity.

Bright grey alabaster, with green and yel-
lowish spots, from the river Niso, in Sicily ;
which affords many curious marbles, and other
substances.

Gypsous alabaster, waved with red and deep
yellow ; from Taormina, in Sicily ; another re-
markable spot for a variety of marbles and ser-
pentines, some of which were known to the
ancients.

Translucent alabaster, of a bright yellow
waved with white; from the isle of Gozzo, near
Malta.

Travellers seldom observe whether a substance
be found in such abundance, as to be useful to
the arts. Hence even celebrated cabinets are,
in the present confusion of the science, filled
with specimens from little fragments, or boul-
ders, and vein-stones, which merely please the
eye, and lead to no solid purpose of utility or
science. A final and perpetual division into li-
thology and petralogy, would obviate this among
many other inconveniences.

Anydrous alabaster, from Grenoble.



504 DOMAIN V. CALCAREOUS.



MODE XL CHALK.

Characters. Texture earthy, rather fine, on a large scale
generally stratified, with interposed layers of
detached flints at regular intervals. The flint is
sometimes schistose and continuous, as in the
neighbourhood of Margate, and the North Fore-
land.

Hardness, of course, cretic. Fracture, even,
earthy. Fragments amorphous, blunt.

Weight, pumicose.

Lustre, dull. Opake.

The colour is a dull white, proverbially known,
but, wanting the brightness of alabaster, has
never been used to celebrate the charms of
beauty. From the decomposition of the balls
of iron pyrites, which it often contains, it may
in parts assume a yellowish or greyish tint.
Sites. Chalk not only forms rocky cliffs, of a most

regular, bright, and imposing aspect; but may
be said to constitute whole regions. A large
portion of the south of England, and the north
of France, consists of chalk; which, in Hamp-
shire and Kent, is often covered with the hop ;
and in Champagne affords a light vivacity to the
vine. It also appears in the flat islands of Den-



MODE XI. CHALK. 505

mark ; while, in other countries, it must rather
be regarded as a rare production. This extent
of chalk in a N. E. direction, and its absence in
the other parts of the world, is a most grand
and singular geological fact, which does not
seem to have invited deserved attention.

Mr. Jameson's account is so concise and
exact, that its insertion will please the reader.

" 1. This appears to be one of the newest of Jameson'*
the floetz formations, and is nearly the last link
of the great limestone series.

" 2. It is very simple ; for it contains, besides
chalk, only a small portion of flint. The flint
occurs in tuberous shaped masses, or in the
form of petrifactions imbedded in the chalk;
and sometimes it forms thin beds, which are
more or less continuous, and alternate with
thicker beds of chalk. It contains but few pe-
trifactions, and these are principally echinites,
ostracites, and belemnites.

" 3. It is more or less distinctly stratified.
Like all new formations, it contains but few
metalliferous fossils. "All that have been hitherto
found, are iron pyrites in small balls, and small
portions of iron ochre.

" 4. Very few observations have been hitherto
made, with the view of ascertaining its relative
antiquity. Its occurrence on the sea-coast, and



506 DOMAIN V, CALCAREOUS.

its earthy aspect, point out the lateness of its
formation.

" 5. It occurs only in low situations, and most
frequently on sea-coasts, where it forms con-
siderable cliffs; but when it occurs in inland
situations, it rises into hills of considerable
height.

*' 6. In England, it extends through Wilt-
shire, Hampshire, Surry, Middlesex, Essex, and
Kent; and appears on the opposite coast of
France, and stretches through the Netherlands.
In the Baltic, it occurs in the islands of Zealand,
Moen, Rugen, Wollin, and Saltholm ; and it ex-
tends from Saltholm to the Swedish province
Schonen. According to Dr. Steffens, the chalk
at Stevens-klint in Zealand, and that of Moen,
rests upon an aggregate of nautilites, serpulites*
chamites, and corallites."

Shells, To the petrifactions may be added vast de-
composed ammonites, as at Margate, pectenites>
large pinnites, as at Meudon, near Paris, the
glossolites or glossopetrae, called petrified pa-
lates, often of a bright brown and great beauty * ;
with what are called Judaic stones, seemingly
spines of a large sea-urchin, dionites, &c. It
has been remarked that the petrifactions in chalk

* See Woodward and P. Tr. No. 232.



MODE XI. CHALK.



seem more ancient than those in many lime-
stones; and Brongniart has observed that they
are chiefly pelasgian. The shells are often
changed into flint, particularly the echinites.
Sometimes unaccountably the shell retains its
original appearance, and even lustre when
broken; while the interior is a mass of solid
flint, which has also been found to pass through
the shell without affecting its texture, which
could not have happened if the flint had been in
a state of fusion from heat.

Patrin informs us, from Buffon, that a chalk
region is also found in Poland ; but he adds par-
ticularly in the territory of Sadki, where it is
only found above an iron mine, with beds of
other substances. This may perhaps be a soft
white limestone, like that sometimes used at
Lyons, and which has also been employed in
building the famous bridge of St. Esprit over the
Rhone. Some^ regard this last as a highly in-
durated chalk, which may be cut with a common indurated.
saw, and becomes, like most other stones, more
solid by exposure to the air, losing what the
quarriers call the rock water.

There is, on the other hand, a kind of chalk,
which may be regarded as crude and imperfect,
often consisting merely of comminuted shells;



DOMAIN V. CALCAREOUS.

and such are the falunes of Touraine, and other
parts of France.

Uses. Its use, as a manure, seems to have been long

known; and the numerous chalk-pits in Eng-
land, sometimes of vast extent, have been dug
for this and other purposes. When cleared by
water from foreign particles, it is allowed again
to condense, and sold under the name of whiten-
ing. Spanish white is merely refined in this
manner ; and the name is arbitrary, as it is manu-
factured in the north of France. Spanish white
not having the poisonous qualities of white-lead,
there is room to regret that it is not brought into
niore general use. Such are, it is believed, the
chief consumptions of chalk 5 the use of which
is rather condemned at the alehouse; but it is
also sold at the shops for many domestic pur-
poses. In Woodward's time, the British seamen
generally carried chalk eggs from Kent, being
echinites, supposed to contain the purest kind.
They were used to correct sickness, diarrhoea,
and other disorders of the stomach, arising from
salted or gross food ; and the absorbent powers
would be approved by the modern physician,
especially if chalk contain 11 of magnesia, as
asserted by Bouillon Lagrange ; but other che-
mists have only found about 60 of lime, and 40



MODE XII. TUFA, 509

of carbonic acid*. The chalk-stones which ap-
pear at the joints of gouty persons, and greatly
resemble that substance, are now said only to
consist of uric acid and soda.

The structures and aspects of chalk, are rather
various in minute parts, than in general masses;
so that an excess of precision in this respect
might, as sometimes happens, only introduce
erroneous ideas.

Chalk, with various shells ; from many parts
of England, France, and Denmark.

The same, with the shells in flint.

The same, with balls of pyrites diverging!/
radiated.



MODE XII. TUFA.

The name of calcareous tufa, is most justly Description*
applied to a light and porous rock, gradually
formed and daily increasing by the depositions
of springs and streams much impregnated with
stony matter. It is, of course, the newest of all
the mineral productions; and often contains

* Da Costa, p. 77, says that chalk, called creta, from Crete,
tvhere it is found, as it is, among other places, in the archbishopric
of Cologne, is used for the heartburn and diarrhqea. It is also
employed in manures, to cleanse metals, and in baking sugars.



510 DOMAIN V. CALCAREOUS.

moss, grass, and other vegetables. The forma-
tion in many instances is so rapid, that it is ap-
Very modern, plied to the purposes of art. Nests of birds,
and other small objects, are subjected to the
stream ; and, when covered by the deposition,
are said to be petrified ; an erroneous idea, for
they are merely clothed with tufa. Such is the
tufa common on the banks of the Tees, and
other rivers in the north of England. By its
lightness it is well calculated for vaults and roofs
in buildings, where the use of wood would be
dangerous; and, by its open intervals, admits
the mortar, so as to form as it were one coherent
mass ; and it was used by the ancients in many
constructions. The Pharos, at Dover, is chiefly
built of tufa, from the north of England*.

But as the Italians first used the word tufo,
and seem more generally to have applied it to
volcanic accretions, there is no impropriety in
extending it, as is often done, to many loose
and porous stones, evidently of recent forma-
Conciutie. tion. Thus the shelly tufa of Gmelin, consist-
ing of broken fragments of shells, with sand and
gravel, loosely joined by a calcareous cement,
might perhaps be more properly classed here

* This tufa seeming to join substances together, was exhibited by
the surgeons in the fracture of bones, and called ostcocolla.



MODE XH. TUFA. $\ \

than among the glutenites. Of this stone the
celebrated temple of Jupiter Olympius at Agri-
gentum, or Girgenti, in the south of Sicily, was
constructed, as appears from the ruins. The
coarse limestone of Saillancourt, used in build-
ing the beautiful bridge at Neuilly near Paris,
also approaches to this kind.

The Travertine, with which the church of St.
Peter, at Rome, is constructed, is also a tufa,
daily formed in the waters of the Anio, now
Called the Tiverone.

A fine calcareous tufa is also formed in an- ofaquedncts.
cient aqueducts, in like manner as we see it
every day in our tea-kettles. The ingenious
Brard says, " Being in Languedoc, towards the
middle of June, 1807, 1 visited the great Roman
aqueduct, known by the name of Pont du Gard:
I ascended into the gallery which terminates this
bold monument, and in which, anciently, the
water ran which was conducted from Uzes to
Nismes : I observed that the sides and bottom of
this canal are encrusted with coarse tufa, 18
inches thick. In like manner also, and what
has happened under the eyes of the Parisians,
when in new modelling the garden of the senate,
there was found, in digging the soil, canals;
which are said to be as ancient as the time of
Queen Blanche, and which brought the water



DOMAIN V. CALCAREOUS.

from Arcueil to Paris; and these canals were
entirely filled with the same sediment which
that water deposes, even now, on the surface
of all bodies on which it remains a certain
time."*

Some establish a distinction between tufa and
sinter; that the former is deposited in the open
day, while the latter is formed under ground.
But this seems arbitrary; and depositions of the
purest alabaster, or alabastrite, may be equally
formed in the open air, as at the Baths of St.

stFeiippe. Philip, in Tuscany, where they appear equal to
the most beautiful marbles, being received in
moulds with the heads of Roman Emperors, and
other objects. This ingenious manufacture was
established by Mons. Vegni. But such objects
belong to lithology; and the name of tufa will
ever imply a coarse stone used in architecture.

Travertine. Of this kind, by far the most celebrated is the
travertine, already mentioned; as it has been
employed, both in ancient and modern times, in
the construction of the most magnificent edi-
fices of the most magnificent city in the worldf.
Hence a more particular account will be found

* Brard, 466.

f For example, the Coliseo or Flavian amphitheatre. Petrini,.
i. 138, says the Travertine is of a sweet yellowish vflute, and
hardens by time.



MODE xn. TUFA.



interesting, and shall be given in the words of a
skilful observer.

" The Anio or Tiverone, which descends from
the Apennines of Vicovaro and Subiaco, to the
east of Rome, before reaching the plain where it
unites with the Tiber, crosses Tivoli ; a place
equally known to the learned and the artist, by
its ancient monuments and its beautiful views,
which have employed the pencils of the greatest
masters. All the land through which the Anio
passes in Tivoli, whether near the great cascade
or the smaller ones, is filled with masses of a
calcareous stone, produced by the deposition of
its waters. Sometimes a piece of rush or reed, or
other vegetable matter, is the first point to which
the calcareous earth begins to attach itself. It
generally deposes in concentric layers, and has
the hardness and fibrous tissue of alabaster.
These layers are nevertheless separated by a bed
of calcareous earth, friable, yellowish, and very
fine. At the foot of the mountain of Tivoli,
where the Anio enters the plain, which extends
to Rome, are the quarries of travertine. This
calcareous rock is disposed in horizontal beds :
its colour is yellowish white, its grain earthy,
fracture uneven, and its hardness far surpasses
that of those calcareous masses produced by the
Anio, in the neighbourhood of Tivoli. Cavities,

VOL. i. 2 L



DOMAIN V. CALCAREOUS.

where the calcareous substance has assumed a
sparry grain, and stalactitic forms, are common
in travertine. Sometimes these cavities have
been since filled by a calcareous stalactite,
whiter, of a finer grain and harder. This is the
origin of those white spots ; the regularity of
which, has caused them to be mistaken for ma-
rine bodies enveloped in its paste. Travertine
contains no remains of marine substances ; but
sometimes it affords fragments of vegetables.

" It is not doubted but travertine owes its
origin to the depositions of the Anio ; deposi-
tions which, in the plain, may have formed a
more solid and compact rock; because its cur-
rent was less rapid, and perhaps its waters more
stagnant in several places. Not far from the
quarry of travertine is the Solfatara, so called
on account of the great heat of its waters, which
abound in sulphuric hydrogen gas, and form a
considerable sediment of calcareous matter. A
Cardinal d'Este caused the canal to be dug,
which conveys the waters of the lake to the
Anio. The calcareous depositions are there so
abundant, that, if every three years it was not
cleaned out, it would be closed up, notwith-
standing its breadth and depth. The water
which runs in the canal, on meeting with bits of
rush or other bodies, covers them with a white



WODE XII. TUPA.

calcareous crust, two or three lines in thickness.
These incrustations are known by the name of
Comfits of Tivoli*. Before this passage was
opened, the overflowings, to which the lake is
subject, were often so considerable that the water
spread over the neighbouring grounds, and
formed on their surface a stony crust. The
water of the lake so charged with calcareous
earth, uniting with those of the Anio, in the
floods which their union must produce, have
themselves contributed to the formation of tra-
vertine. I do not think that the Anio alone
would have been capable of forming the quan-
tity which is found of that rock.

" Independent of the immense quarries work-
ed by the ancients, there are besides others of
such vast extent, that they may supply the de-
mands for many ages.

* <f Dr. Vegni had established there, a manufacture of bas-reliefs,
analogous to that which he possesses in Tuscany, near the Baths of
St. Philip. The ingenious method by which he forces the water to
form the bas-reliefs in a short time, which by the exactness of the
design and the hardness of the stone, are not inferior to the originals,
is sufficiently known by the relation^ pf most modern travellers in
Italy.

" I shall only add, that the colour, grain, and hardness of the
stone formed by the waters of the Solfatara of Tivoli, as well as the
neighbourhood of Rome, which furnishes so many beautiful models,
and skilful artists, give this manufacture a decided advantage over
that of Tuscany."



516 DOMAIN v. CALCAREOUS.

c< The lake of Solfatara seems to have greatly
assisted in the formation of this rock. Its water,
charged with much gaz, explains by that qua-
. lity the great number of hollows which travertine
presents. It proves that when the rock harden-
ed, a gaz has at the same time escaped in several
places, which has prevented the approximation
of its parts which were still soft. As often as
the interior of a mass of rocks presents cavities,
without any indication of foreign substances,
which might have opposed the union of its parts,
I conceive their origin may be attributed to the
escape of gaz, at the moment when the sub-
stance was passing from a state of softness to
solidity, by cooling or drying.

" From what I have just shown, it follows that
travertine, or rock of Tibur or of Tivoli*, is a
carbonate of lime, formed by the depositions of
the Anio and the Solfatara of Tivoli. The
Roman artists give the name of travertine only
to the stone taken from the quarry, situated at
the foot of the mountain of Tivoli. The litho-
logists, less slaves to locality, bestow it on all
calcareous rocks which possess the grain, tissue,
and formation analogous to that of the traver-
tine of Tivoli. If the ancient and modern

* Tibur linum of the ancients.



MODE XII. TUFA,



Romans have employed this stone in the most
noble structures, they have but followed the ex-
amples of other people before them. The tem-
ples of Pestum, the most ancient monuments
that are known after the pyramids of Egypt,
were built with a travertine, formed by the de-
position of waters which still exist in that dis-
trict. This stone, when long exposed to the
air, acquires a considerable degree of hardness j
its colour assumes a reddish tinge, .pleasing to
the eye, and which in no small degree contri-
butes to bestow on monuments of antiquity that
majestic character which is so striking. Buch
justly observes, ' that the temples of ancient,
the churches and palaces of modern, Rome,
would infinitely have lost of their grandeur and
majesty, if the bold genius which erected them
had not met with such a material as travertine.
They would have lost much of their solidity, if
the formation of tufa had not given rise to the
discovery of puzzolana.' The chance which
collects in its vicinity the materials most fit for
architecture, travertine, and puzzolana, was not
a little happy for Rome. The mortar or cement,
which results from a mixture in just proportion
of that ferruginous volcanic earth with lime, so
much surpasses in hardness all other known



518 DOMAIN V. CALCAREOUS.

cements, that the exportation of puzzolana, by
the Tiber and the Port of Ostia, is become a
little branch of trade."*

From the preceding observations, it might
be understood that there are at least three dif-
ferent structures of the calcareous tufa: the
/

porous, or that of the travertine; the shelly, like
that of the ruins of the temple of Jupiter; and
the tubular, like that of Germany, and the north
of England.

STRUCTURE I. POROUS.

Travertine, from the ruins ,of Rome.
The same, from the quarries near Tivoli.

STRUCTURE II. CONCHIT1C.

From the ruins of Agrigentum or Girgenti. It
is found in many other places, but has excited
little attention, being probably regarded as a
coarse limestone ; while its lax composition refers



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