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Full text of "The life of Field Marshal the Duke of Wellington"

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1? IE T la A 3L © 'S T . 

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:jLS)iYliMY. 



«■>*<■ 



PETRALOGY. 

A TREATISE ON ROCKS. 



INTRODUCTION 
TO THE SECOND VOLUME. 

Having in the former yolume comprised all the Dooudns Aeddential 
which may be called Substantial^ as depending upon the pre- 
dominant substance^ under various modes of combination, it 
is now necessary to enter on another field, that of the Acci- 
dential Rocks, which must of course be arranged according 
to their Tarious accidences*. These accidences being, so to 
speak, infinitely diversified, and independent of any Mode in 
the sense used in the former volume, and often even of Struc- 
tures and Aspects, it was necessary to adc^t new denomi- New terms, 
nations. Even the Domains now become what might be 
called Dominions in the natural kingdom, as they no longer 
imply the preponderant or predominant substance, but grand 
divisions arising from natural accidences, as the Volcanic and 
Decomposed Rocks. 

But while the term Domain still seemed unobjectionable, 
it became necessary to abandon the other subdivisions, which 
being derived from the substances, and their qualities, could 
have no place here. Instead of denominations strictly arising 
£rom the very essence of the subject discussed, the subdivi* 
sions themselves became, so to speak, aeddential and arbi- 

* Plinj bu natitrm aeddenHai Cicero ccddeniia for ra 9iiribuUf, Acci^ 
dtnn is here used in coDtndittinctioii to atddenty which, in eommon Eoglith, 
implies m moral efent or incident, not tn aocidentil circumttuioe in natnic. 
Accidence is here « mtonl cifoilty, «a tdventitioaf ittribate. 

VOL. II. a 



19861 ft 



u 



INTRODUCTION. 



Nome* 



Hyponome* 
Bficroiioinc. 



Terms lome- 
timet bx. 



traiy. The only idea that arose was to select terms that 
might indicate subdivisions of the Domains, and still, if pos- 
sible, preserve some relation with chemistry, upon which the 
whole science of mineralogy ultimately depends. In Egypt, 
universally known to have been the parent country of che- 
mistry, the small pro^noes or districts tvere distinguished by 
an appellation which the Greeks have translated Nombs, 
from a word simply implying divisions. But the word may 
be said to have remained sacred to Egypt, not having been 
transferred to the provinces of any other country. This 
word had also the advantage of subdivisions easy to the me- 
moiy, in Hyponome and Micronome, implying greater and 
lesser subdivisions of the Nome. 

Such were the reasons for the preference of this arbitrary 
term to any other arbitrary term ; and as it cannot be too 
often repeated that the chief use of any system of natural 
history is to assist the memory, it will perhaps be difficult to 
find a term le^ objectionable ; at least, though the plan has 
been deeply reconsidered for many years, none such has arisen 
to the author : but perhaps candid dbquisition, and literary 
collision, may produce some more appropriate appellation, 
which he would be the first to adopt, having no view but the 
advancement of the science. Even in lithology and metal- 
logy. Nomas Will be found preferable to the Groups or Fa- 
milies of the Wernerians, denominations chiefly belonging to 
animated nature ; and the dear metallic divisions of Thom- 
son, Alloys, Sulphurets, Oxyds, and Salts, may well be styled 
Nomes; for the term being arbitrary there can be no obr 
jection to its occasional introduction even under Domains 
which are substantiaL 

Above all it must not be forgotten, that in no science;^ 
except those that are mathematical, can the terms admit 
mathematical precision. In the other kingdoms of natural 
history it i^ well known that disputes frequently arise whe- 
ther a new object form a genus, a species, or a variety. 
How much more vague, therefore, must be the language ot 
mineralogy, which depends on the infinite modifications of 



ivTioeiicTtoif. lUr 

the Taiioiis iiibsCaiioes formtiig thedhellorcniBt of thisTast 
giohe ? Iq iprc aac d with this tdek, Ptetrin has pronofunced that 
the best arraagemcnt is that which is the most lax> because 
pfreteaded precision would in itself be a radical error: for 
nature is not regular, but f^ree ; and it becomes pert of the 
perfection of a system to partake of that freedom. To ex- 
pect, therefore, mathematical exactness,, or meCapfaysical 
aeuteness, in the arrangemeBt and nomenelature of natural 
history, would be foreign to the very nature of the science 
itself; and if even the most precise and mathematical terms 
could be found, they would be improp^ in mineralogy,: 
where the substances themselves are inaccurate, and all the: 
^visions are mutually intemmigled, and graduate into each 
other. In the Substantial Domains even complex rocks, as 
granite, &c. are equally simple with some substances regarded 
as homogenous^ and smaragdite, fbr example, will present' 
aa numerous ingredients. But in the Substantial Domains 
the Modes are variations of the same substance, and naturally 
rollow each other ^ while the NcHnes are compounds wh<dly 
difierent in themselves, and connect detached substances in 
an arrangement totally distinct. In the former case the 
terms themselves may be regarded as definitions, which is a 
great advantage in any science ; while the Nomes must, from 
the very nature of the subject, be considered as arbitrary 
divisions fbr the sake of memory. In this point of vidw n 
system may be compared to a cabinet; and if each substance 
can find its proper drawer and place, the object of utility and 
deamess are answered. But at the same time eveiy system^ 
even the Newtonian, has its anomalies. 

In this, as in the former part, it became a chief otiject to Nomendstiire. 
increase the nomenclature, the poverty of which has long 
been regretted by Saussure, and other able authors. Buffi>n 
ineseats some useful observations on this topic '*Men have 
begun with giving difierent names to things which have ap- 
peared to them clearly distinct; and at the same time they 
have formed general denominations for objects which seemed 
to resemble each other. Among savages, and in all new Ian* 

a£ 



! IHTftODUCTiOK* 

gtttigcs, the nankes are almost always gtoeni, that is to bbj, 
Vague expressions for objects of the same similitude^ however 
distinct An oak, a beech^ a linden, a yew, a pine^^i fir, 
will^all at fint be called a tree^ then the oak, the beech, the 
linden, will aU be called oaks, tOl they be distinguished from 
the others, i^hich will be called pines. But particular names 
will only be found in an advanced state of society, after com* 
parisons and examinations j and the number has been always 
increased in proportion as nature is more studied and better 
known; and the more it is examined and compared, the 
more abundant will be the proper names and peculiar deno- 
minations. But when we are now presented with general 
terms, that is genera, it is to send us back to the A B C of 
knowledge, and recall the darkness of the in&ncy of nations. 
Ignorance has created genera, science has produced, and 
always will produce, proper names 5 and we are never afraid 
to augment the number of particular denominations when 
we wish to designate different objects." 

This eloquent author was, however, too inimical to systems 

of nomenclature on the Linnsan plan; and hb observations 

may be considered as chiefly applicable to mineralogy, in 

which the arbitrary divisions have been so often confounded, 

as has already been explained in the general introduction to 

this work. The most severely scientific writer on mineralogy 

Bsny's jg Ha»y, but even he has been obliged repeatedly to change 

^^ ^"^ the subdivisions ; for in the first class he has genera, in the 

second only species ; in the third there are two orden ; in 

the fourth three orders, and every metal forms a genus. Nay, 

as already stated, he has changed the very foundation of his 

plan, having formally abandoned the integrant molecule, 

* which, as he supposed, constituted the species, for the primi« 

tive form, as he confesses that he was often deceived by the 

integrant molecule*. This molecule was the invention of 

* Hit tTgomeDt tlmt ciysttls memble the flowcn of pkntt, u m criterion of 
•peciet, i* not just, the ciystds being often difieveDt firom du tubtunce, quits 
in limestone, barytes in gnnite, &c. &c. 



IMTXODVCTION. 

the ingeDious erystaOogist Roin6 de IJsle -, and fonned the 
foundation of the singalar production of Dolomieu on the 
Mineralogical Species, in which he goes so far as to assert 
that this species can propagate itself! This nugatory propo* 
sition seems merely to have been advanced/ because he allows 
that without this quality no species in natural history can 
exi^t. Let it not be ima^ned that such observations, ex- 
torted merely by the impulse of truth, are intended to violate 
the respect due to those great vmters in other departments 
of the ^science, which is sufficiently wide for the devdopement 
of various talents | and though the eagk requires a whole 
province of rocks for his immediate domain, there is in this 
science ample space for invention and ability, without enmity 
and without envy. 



It is hoped that the nature of the several domains con- 
tained in this volume will be found to be sufficiently illustrated 
by the observations at the head of these divisions. One of 
the most important, in eveiy point of view, is the Volcanic, Volcamo 
an object of ludicrous neglect and contempt to the German 
minerabgists, whose confined ideas have been the more im- 
I^itly. followed, because the Germans are the bXhevB of mo- 
dem mineralogy. It will here be found to be treated with 
t&e details, and it is hoped with the accuracy, which the sub- 
ject deserved, not only firom its own importance, and contra- 
distinction firom all the other domains, but on account of the 
infinite contestations which have arisen on this topic among 
th^ most eminent writers in the science. Diffident, however, 
of his own ideas, it gave the author singular satisfoction to 
find them confirmed by those of the first chemist of this or 
any age, as may be judged by the following extract from one 
of our weekly journals *• 

• 

• Obierrar, JttM ad, isu. 



Ti IMTKOSUOnOir* 

* 

Dr. Dayy^ '' In the condudii^ leetnrej ]>r. Davy stated, that the 
oUemtioiis. ^^^g^^^j^ of lam from volcaaoes was one of the priiicipal 

i]|iefmttana by whkh nature AippUed the waste i)fTOck8> and 
the destruction of the land noticed in his fbrmer lectures. 
The agency of volcanoes m the production of islands, and the 
increase of cantinentSj is more extensiTc, than those who 
** nside at a distance from their influence are disposed to admit. 
Apdofr of this may be traced in the islands and slioces of the 
If editerranean> in the continent of America, and in AsiSy 
and in cither parts of the ^be. Nearly' the whole of Sicily, 
and the southern parts of Italy and Frvnce, oftr evidenoe'of 
their voleanie origin; and Boine, which has by ancient writers 
been proudly styled the ^' £teriialGity," is built on the otater 
of an extinct volcano. The phenomena attending^ the eaxpp 
tion of volcanoes were described from Hamilton, Dolomieu, 
Spalanzani, and others, who had been present during the 
eruptions of £tna and Vesuvius. 

' " The oonvukion of the solid ground, the lofty columns of 
flame, smoke, and vapour, the tremendous explosions, the 
toivents of rain, and the thunder and lightning, which ac- 
company the etuption of lava, aU indicate tiiat the immediate 
eaiase is the expansion of steam and hydrogen gas» which in- 
flames when in contact -v^h the atmosphere. The doctrine 
of^ central Are waa unsupported by proof or analogy: did 
Such a fire exist its efleete must be felt at the suifrKse, even 
if it bad to pass through the most imperfect conductors of 
heat. 

<' To ascertain the cause which produced the expansion of 
tapour, and the other phenomena of volcanoes, we must 
examine the products of these august operations of Natural 
Chemistry. If we observe a fire at a distance, and are abl^ 
to odlect its products, we may thence determine the nature 
ef the substances which have been in a state of combustion; 
The products of volcanoes are hydrogen gas, vapour, and 
laya, of which lava is a compound of the earths, the alkalies, 
and the oxyd of irond-4n his ibnner lectures^ Dr. Davy oh- 



i 



IMTtOOOOMOM. yH 

served, that he had stated ttaedisdomy of the mataHie jwtnre 
iof the earths and the tfkaliefl> and tihat the metals obtaiaid 
•from them ^^re in a high dcgtee inflamreabie vrbma'^tt^ 
came in contact wkh ^(mfer. — Dr. D«vy ftirther obsenned^ 
that previous to the eruption- of volcaaioes, the lakes nnd 
Springs in their n^ghbourhood were known to hnveeodden]^ 
<&appeared,' and idlthe volcanoes which are inadxvl^aivlm 
the neighbourhood of the sea« or of iaigekkes^, ' Now IP 
we admit that these earths exist under the surfisuBe, in a mer 
tallic state, the access of water to them would ooeaskm their 
t»mbustion. The oxygen would be absorbed, and anim* 
mense volume of hydrogen gas Would be produoed, whiefa is 
always found to follow the eruption of flames^ This ex- 
planation of the cause of volcanoes may be coniMered as a 
teasonable influence ftom the disooveiy of the metalttc natOM 
of the earths j and if we admit the operation of electrical 
agency in the globe, we shall have a cause operating by whieh 
^e earths may be restored to tbef^ Aetallielbrm. llniaHM 
process of renovation and decay will be constaiitfy balafiefog 
each other, and nature be preserved in a state of etenial 
youth. The appearance of the Auitwa BoreaMs aiotf iilb 
Aurora Australis, render it probable that the {K>les are tik 
%wo difierent states of electricity, and that a constant circu- 
lation of efectncpdWer Id tydngpliee. ^ 
' " Though new land and soil may ^us be formed^ DtJ J^ty 
said he was not inclined to admit that the pnlkiary<^uMl se^- 
tx)ndary rocks were thus produced. The ciTStals they CMtaih 
are di^rent from those ever found M lavai • l%ib eacpertmettfo 
of Sir Jsones Hall, which had beeh thought td estsibHsh tile . 
vdk^anie nature of basalt, he conridered as d^edtive. In 
basalt, hornblende and fblspar are diiStinc^ crystalBSed j but 
the fused basalt Which had slowly cooled, though it haid the 
form of btoaltic prisms, did not oohtain 'hornblende tfrMspsr 
in distinct crystals. 

* The Andes are from 80 to 100 miles cUstaot from the set, tod are oiUy 
MiieDciid by snbtenmetD Utet. P. 



viii iirasootroTiosr. 



' '' Mr. Watt haying ftumd a laige quantity of bandt, la tlw 
cmtte of tbe mass wbkh was ^wly eoded^ the crystals of 
basalt weiekfge; but they grew less as th^ approached tba 
Burfiioe^ which was amorphous and vitrified. 

f' The la^ emitted from volcaiioes is speedily deccMnposed 
by the action of moisture and the atmosphere, and forms the 
most fMile soils. No countries are more productive than 
those in the vidaity of volcanoes, if below the line of per* 
petual.snow. The volcanic island of Santorin, which was 
raised in the Axchipelago in one night, in the year 1770, is 
now in part covered with a luxiiriant vegetation, and no 
country in Europe is more productive thap the Jpwi^r dedi* 
vities of Etna. 

*' .The operations of. nature are on a scale too extended to 
be o^easured by days or years : they require ages to produce 
their ftiU eiecL What appears destructive and desolating at 
the first v]ew> is found on a more comprehensive examination 
tOibe attended with permanent advantage. The lava and the 
«shes which burned Herculaneum and Pompeia^ have fur- 
nished abundant harvests for fifteen centuries. The evils 
that nature inflicts are transient, but her benefits are of last- 
tfig duration." 

It is .unnecessary to warn the reader that this extraet is not 
from the hand of the.excellent author, and that of course it 
is only the general current of the ideas which deserves atten* 
tion. Bat as the Germans have too much restricted, or 
rather annihilated, the influence of volcanoes, it seems here 
Space of to be rather too much e^laiged : for if we suppose two hun- 
appcHM^ces. ^'^ existing volcanoes,^ and compute the medidm of their 
agency at thirty miks each, the amount will be six thousand 
sqtis^ miksj or at the most equal to the island of Sicily> 
about seven thousand two hundred. But the extinct volr 
cano^ would probably more than double this extent $ and it 
seems certain that in the chaotic and ancient state of the 
globe, before the component substances had acquired their 
pr,esent solidity and temperature, numerous volcanoes miist 
have existed/ which have been totally and radically e^^tin^ 



f\ iwnoDVOTioir. 



gnished; while in nxxkm timet perbaps only tvm ▼olctaoes 
wlioily new have appeared, that of jQruUo, in New Spain, 
and that of Oahorra, under Hie peak of Tenerife. The in- 
fluence of heat in the diaotic state of the world is well ex- Chaotie heat 
plained by an able though anonymous author. 

" Incessant and infinite motions nrast have existed in Ghaos, 
from the uniTcrsal operation of endless varieties of unsatu* 
rated attractions and repulsions. In those vast fluctuations, 
therefore, of universally intermingled and heterogenous par- 
ticles, quantities possessing every order and degree of affinity 
must have come within their mutual spheres of attraction. 
The weaker affinities must have been overpowered by the 
stronger; and thus, in tlie process of time, immense quanti- 
. ties of uniform quiescent and digested masses of matter must 
have been produced : and in .these formations do we trace the 
first rudiments of oiganised nature. In them we find the 
origin of earths, metals, adds, alkalis, water, and atmospheric 
au*. 

" Combustion, or oxygenation, is the grand and prindpal 
chemical process by which most, if not all, such compounds 
are by the new system of chemistry known to be formed $ 
even water itself, so long supposed to be a simple dement, is 
now proved to be the combination of hydrogen and oxygen 
by combustion. Nature every where presents proo6 of the 
t^gency of fire in her primary combinations ! 

*' As fire has been seen to be the first process of nature in 
the formation of digested masses out of chaos, so is water 
found to be the great oigan of arranging these masses in the 
next operation of nature, in the formation of the spheres: ^ 

and here may I not for one moment pause, to observe how 
admirably this reconciles the contending opinions of geolo- 
gists as to which of these agents has been employed by na- 
ture? Each of these sects has produced innumerable argu- 
ments, innumerable documents and instances, to prove his 
theory; and, in truth, nature abounds in appearances, in 
examples, of the agency both of fire and water. In the de- 
monstrations before us we behold each serving in its turn the 



iirvxoonoTiON. 

great purposes of B^tare; we behold the one employed i& 
the mdimAial cattibmBtifm t>f substances, the other in the 
^merai arrmkgement of the phoU, We behold the contradie- 
toiy ofnaions of theory, and the dbenity of a|^)earanoe8 in 
nature, connected and harmonizing with the' truths i^ mq* 
iiem chemistry \"* 

-' JNor most it be foi^gotten that our ideas of a chaotic state 
peem to be confined to this globe only, instead of being at 
least extended to our solar system. And if we conceive, with 
La Plaoe, tliat the planetary bodies were formed by the con- 
cretion of an amfbnn llaid, emanating fh>m the sun, which 
derives Ite splendour from the Deity, the fountain of light, 
human imagination can never conceive the universal eibt<- 
vescence and developement of various vapours and gasei, 
which must have appeared in the primeval universe. But in 
this and other grand ideas the prince of modem philosophers 
twill ever be found to lead the way, having thus expressed 
Newton's himself in his immortal Principia. ** The vapours which 
arise fix>m the sun, the fixed etars, and tlte tails of comets, 
may ihll by their gravity into the atmospheres of the i^anets, 
where they may be condensed and converted into water and 
humid gases \ and afterwards by a slow heat graduate into 
eahs, and sulphurs, and tinctures, and mire, and mud, and 
olay, and sand, and stones, and corals, and other earthy sub- 
stances.** t Did not this eagle of intuition thus foresee the 
pneumatic chemistry ? 

The important geological observations of Dr. Davy on the 
subject of volcuaoes also exdte, and may authorise, some 
0ther gen^vi remarks cm the dieory of the earth, which will 
Hot, it is hoped, foe found wholly digressive. 

* Sketch oft New Demonstntton of Ntturei London 18 10, Svo. 
- \ Vapoves aatem qnl ol sole, et iteUtp finis, et caudis oometsmm oriantoff, 
inddere possqut per gmvitatem suam, in ttmqiphseias planetsrum j et tbi coo- 
denssri, et converti in aquam et ^ixltua humidos : et svibinde, per calorem lea- 
tnm, in sales, et salphara, et tinctuias, et limum, et luiom, et aigillam, et 
treoam, et lapides, et coralla, et substantias alias terrestres, pauUatim mignre. 

NswTOM Princpart ii. pnp. 43. 



i 

f 



IVTBOOtJCTIOir. 



' The original violent xapidity of tbe.earA 
cause a prodig^ue evaporatioa of the primeral wa1»B> as 
in the taU of a comet : and in the general duos, of tin* 
aokr system some esteem it not impossible that a safaHlfe 
aiay have struck a planet, and have merged in it> or feane 
lieen diffiased over it; fvhile the shock may have prodlided 
the refoulements of Saussore, which he seems to ascribe to an 
external cause *; in which he is followed by Dolomieu; who 
compai;e8 the strata of the globe to the shell of an egg, Om^ 
ttted by a squeeze of the hand. Some recent writers have 
also, on other grounds, adopted th6 same opinion. 

As thtfelbre, in the ideas of Newton and La Place, strength- 
mied by many discoveries of pneumatic chemistry, the solar 
fire miist have been a prime agent in the creation, as it Is 
still the chief agent of preservation, generation, and life, it 
knay well be conceived, as nature always prc^rtions the 
power to the efiect, that the heat was at first violent, and 
gradually diminished to the present temperature. Hence the 
impressions of plants, which are now tropical, are A>und id ' 
^climates at present temperate or frigid. The doctrine of 
central heat seems now to be universally abandoned, though 
•If the nucleus of the earth consist of iron, according to the 
writers on magnetism, or of various metals which pass iixte 
earths, according to -Dr. Davy, it is difficult to conceive that 
there should not be a certain heat peculiarly modified, as 
another modification exists in animal lifef. If we judg%, 

* De Luc, though a Geneftn, acknowledges that he does not nndentand 
Saniiure'a refinUemirU, Bemand, aoodier Genevan (Ren. Period. Parb an s), 
intcipreti it JufocrsiiM. Sauran himielf disttngoiihea it horn qffmsaemod, and 
lo one pMHge calls it vn r^fbultmeHt en ma eoniraire. 

f The nstnre and varieties of heat and light are ftrfiom being asoertained» 
Saussure, $ 3347, leganls them as different substances, and dbsenres that the 
-point of the flame actuated by the blow-pipe, though not of a paler blue than 
]lhe lest, yet, deprived of li^, witt convert ,gold into vapours, and yidd the 
greatest heat excitable, by art. Bat the appeaaoee of li|^t most depend on 
tbt degree of daikneiB, which no mtu* seem to fa»«e been invented to 



VI INTKOOUCTION. 

however, fttntn the external constitutioii, the predomiaant 
OBotatl sufafitances are iron and silex^ or the metal of ailex* 
For silex itself, as already explained, ia ftequcfkitly a new pro- 
duction, found in the straw of gnuninous plants and the 
baric of the bamboo. Nay, pebbles of quartz are found in 
the bamboo itself; and often of the size of a pea in the eggs 
of the ostrich*. 
Femn*k Ferrara's able account of the volcanoes of Sidlv has also 
opened some new geological ideas. In one passage he thus 
expresses himself: *^ The natural philosopher who has ex- 
plained the formation, that is, the condensation wad consoli- 
^dation, of the globe, and the inequalities of its sur&ce, as 
being produced by operations arising from an innate power 
in matter, from a power most generally diffused, from a 
power to which nature has put no Hmits of action upon 
the spot which we inhabit, but at the same time destined 
to bind all the parts of the universe together, in order 
to form a well-regulated whole 3 in a word, by gravita- 
tion: it would seem that he approaches nearer the veri- 
similitude of causes : he does not leave the earth in order to 
explain the facts which are found in it ; he has not created 
extraordinary powers ; but has attributed all the phenomena 
to agencies which still operate, although upon another scale, 
but which would renew the ^ame phenomena, if they were 
conducted under the same circumstances. Froxn what I have 
said it mayl)e understood that my opinion is with those who 
suppose that this globe was formed of materials which, being 
first diffused in a fluid, were thence deposited successively, 
and which occasioned aU the disorder which we observe on 
the sur&ce by the sinking of some parts, while others remain 
elevated in their original site and level. Burnet, who not 
long since started this grand and perhaps ancient idea, has 

* See Banrov'a Cape of Good.Hope. Breislak, ii. 305, mey be confolted 
for the diasolvtkMi of silex, whteh he wyt is effected bj water impregnated mth 
cilonc, soda, and sulphur in a state of mpoor. Kirwan, i. 155, says, oxyd of 
iron Vith miaocosmic salt yields a pale green glass, that u, a siliceous substance. 



INTRODUCTIOlf. lOn 



r 



been fbUoWed by nuuny nataral phUoeophers who have ^vea 
it all possible extension^ and^ fh>in physical truths and exact 
observations, have conducted this theory to a degree of verl<* 
similitude of which the others are not ci^bk. I adopt it, 
not only as it appears to me the most consonant to the 
theorems of natural philosophy, but as I find it most proper 
to give the most natural and easy explanation of the fects 
which we observe in Sicily, and which seem to add additional 
proofs to those observed in other regions." ''(^ 

Bouguer, and many other naturalists, have observed, that Sabsidenoe. 
in South America the plains have palpably subsided, and left 
the rocks elevated in many fantastic forms. It is indeed to 
be conceived that the earth, originally in a fluid state, as 
appears from the depresnon of the poles, and many other cir* 
oumstances well known in natural philosophy, and replete 
with innumerable vapours and gases, could only acquire its 
present comparative solidity by prodigious subsidences^ arising 
from the gravitation of the solid and semifluid parts towards 
the centre. The most prodigious of the subsidences must 
have been that which sunk two thirds of the globe' to make 
room for the present . oceans, sufiicient receptacles for the 
primeval waters, if the idea of this vast subsidence can be 
supported. Ferrara, arguing only on that subsidence which 
gave place to the Mediterranean, says that the mountains 
above Reggio are very sensibly inclined towards the sea» 
which indicates that their base sunk to form the channel 
which divides Italy from Sicily. He also observes, that the 
inclination of the strata towards the sea may be seen in all 
the mountains which border the southern side of Sicily f. 
The following passage likewise deserves observation : '* Where 
the mountains are formed of soils in which the lavas are 
united with the calcareous masses, or, toexpljun myself more 
clearly, where a frontier of consdidated lava was filled from 
the bottom to the top with calcareous masses, the series of 
these heights is calcareous on the one side, and volcanic on 

• Fenuty 354. t Ferr. 971, 874. ^ 



the <H^. Sii0k is tl» oMMmtetoowr nmm, ttiminMng ia' 
the aaminiky upon which stands the vilkge of CarlentiBL 
T^ suppose^ indth Ddomieu, that the lata pressed throogli 
the vile^ wheace^ lisiog by the side, it arrived at the top^ 
withonit havkig passed to the other side, is to suppose an 
Older of things which can nerer have existed at the epoch 
when the lava was fluid, in &ct> this division does not exist 
Wheal you proceed towards the west, above Lentini, whei« 
the hivas cover all piarts, that is, the volcanic stratum ooveis: 
all duKt-exle&t. . The same phenomena are obsnrvable in the 
nMHtainiJ of Ganmria, near Vizzini, and in some which are 
in the plsda of Marineo, beyond Licodia. In all these strati* 
form mounCalDs the position of the strata of similar materials- 
oorresponds from one mountain to another ; a circamstance 
wliich may be estimated by the eye, where the hi^adth of the 
valley is not too great. This circumstance demonstrates th^ 
cfaaraoter of the revolutions which have produced these in-' 
equalities.'* * He afterwards proceeds to stsAe the sinking of 
a part of a mountain in 15S6, and the catastrophe which 
happened at Nicosia about 1760, when a fourth part of the 
city, mth the convent and churches bf the Capuchins, sunk 
in one day, so that nothing could be seen but the tops of 
the buildings, and of the trees ) but the people escaped by 
stepping out of the windows. In 1740 the town of Shlemi 
su^red the same misfortune j and in 1790 some lands sunk 
near S. Maria di Nisoemi. He also states that the people of 
a pkice, a few miks to the west of Catania, thirteen years ago 
oooki only see the top of the cupc^ of the Benedictine mo- 
nastery of that dty, the prospect having been impeded by 
tfae.la^a of 10G9, imt now the entue cupola is seen, the 
dndky soil under the Ittva-havingsubsided f. 

Perhaps this doctrine of subsidence might of itself explain 
the inequalities and other phenomena of the earth's surfece, 
tvithout having recourse to any concussion of a satellite or 
other body. The summits of basalt, and the caps of lime- 

• Ferr. 37S. t Feir. S7S. . 



IirT10l>U0TIQM« XV 

♦ 

fltoae, in the TytdLeee, ituglit perbape be ckpUned iA this 
manner^ and ve aie at kast oertaia that the cama exists. 
But it 18 fiaor from the intention of this work to propose or 
sttpport any theory; and these remarks must only be regarded 
as a few aeattered hints which may interest the reader. 

PIbU in what he calls a new theoiy of the earth* supposes PrnTs system.* 
a nudeos surroanded with a fluid zone, which contained the 
dements of the Tarions substances; and he imagines the ^ 
effects and Tariatlona to have been very prompt and sodden, 
owing to the extreme rapidity of the rotation of the earth.- 
He argues for a formation wholly aqueoias; but his chief new. 
foot seems to be a granitic mountain at Gana, in Austrian 
Lombarcty, which is throughout full of cavities, a few inches 
distant from each other, and lined with crystals of quartz and 
felqpar*. 

The chief features of De Luc*s new system of geology De Lac's, 
seem to be the following. He supposes that during the 
dekuge the former continents disappeared $ but this is dearly 
contrary to the Mosaic account 6t paradise, and the whole 
scriptural narrative, which represents the land as stable and 
unalterable. That successive catastrophes affected the beds 
of our continents, even while they were rising under the 
waters by chemical predpitations, being occasioned by caverns 
which formed under them. That valleys, lakes, abrupt pre- 
cipices, existed at the birth of our continents, inconsequence 
of those catastrophes by which the beds were ruined. That 
stony masses and gravd, which are scattered in such great 
quantities upon the cqntinents, are also original features, 
and do not arise from currents ; the flints proceeding from 
beds of chalk dissolved; and the gravel, as well as the large 
blocks, caused by the attrition of fragments, have been ex* 
pdled from the interior by expansive fluids, during the sub- 
sidence' of the beds, an4 dispersed at the same time at the 
bottom of the sea. That the precipices towards the sea have 
not been produced by the sea itself, but are original fbatures. 



* See the OpaiGo]v3celti, torn. xiii. Milan 1790, 4to. p. 069> S79* 



XVi fNTSODVCTIOV. 

resulting from the rupture of the beds, at the time of the 
vast subsidence ivhich sunk the former continents, and pro- 
duced the new concavity of the ocean. 

These theories may be compared with the Wemerian and 
Huttonian, and that of Ferrua, founded, as lie says, on that 
of Burnet The rocks having been hitherto consido^ as 
the chief province of the geologist, it is hoped these few cur* 
sory remarks will not be found foreign to the purpose. But 
Ftetialqgy, as already observed, has little more connexion with 
Geology than its sister sciences lithology or Metallogy; 
and, like them, can only be regarded as an introduction. In 
which point of view these observations may not be found 
unusefol to the student. But it is time to return to the de- 
scription of the Accidentia! Domains, an accurate knowledge 
of which may be regarded as peculiarly indispensable to anj 
system of geology, such theories having so often ooilfounded 
the pride of human science. The more humble sage will 
perhaps be contented with the knowledge of the substances 
themselves, and prefer what Gibbon calls a lbarhbd xomo* 
SANGB to any geological themry. 



• * 



► CONTENTS 

OP THE SECOND VOLUME. 



NoDoel. 

II. 

lU. 

IV. 

V. 

VI. 

VII. 

VIII. 

IX. 

X. 

XL 

XII. 

XIIL 

xrv. 

XV. 
XVI. 

xvn. 

XVIII. 

XIX. 

XX. 

XXL 

XXII. 

XXIII. 

xxrv. 

XXV. 

XXVI. 

XXVIL 

VOL. n. 



f 

DOMAIH Vll. COMPOaiTB. p. 1 

SideriU, toith Oamet Rock 11 

Siderite, Feltpar, Graphite 19 

SiderUe, Unctuous Qtuartz, Pyrites . • • • ib. 

Porphyry, wUh Chalcedony 13 

Jasper y roith Agate and Chalcedony ib. 

Mica and Actinote • « 14 

Actinote, Siderite, Mica ...• *.. ib. 

Quartz, Siderite, Oxyd of Iron ib. 

Quartz, Schorl, and Limestone • 15 

Quartz, Limestone, and Saussurite* ib.' 

Felspar, Quartz, Garnets ..•• ib. 

Felspar, Quartz, Talc 16 

Felspar, Fibrous SiderUe ib.^ 

Felspar, Calcareous Spar .! ib. 

Jad, Schorl, Garnets 17 

Granite and Chalcedony ib. 

Granite, with Schorl and Garnets i • . . • 19 

Granite and Limestone ..•#•«... •• •• SO 

Granite 4tnd Slate ib. 

Gneiss,mth Blue Siderite,, •*,»,, ••,• S7 

Clay, Spathose Iron S8 

Serpentine, wUh Limestone • ib. 

Limestone, ioith Garnets • 39 

Limestone, with Steatite ,.* • 30 

Limestone, with OUmne ib. 

Limestone, with Actinote 39 

MarhU, with Asbestos 35 

b 



i 



• •• 

xvm 



C0KTENT8. 



Nome I. 

II. 

IIL 

IV. 

' V. 

VI. 

VII. 

Vlll. 

IX. 

X. 

Xf. 

XII. 

XIII. 

XIV. 

XV. 

XVI. 

XVII. 

XVIII. 

XIX. 

XX. 

XXI. 

xx!ii. 

XXIII. 

XXIV. 

XXV. 

XXVI. 

XXVII. 

XXVIII. 

XXI3C. 



Nome L 

II. 

III. 

IV. 



Domain VIII. Diamictohic. p. S6 

Sida-Ue, with Silex ; 39 

SiderUe, wUh J^ka M*»«*f ••• 41 

Sideriie, with Felspar ••.....•. .'/••»• .49 

Sideriie^ mth Earthy FeUpqr «•• » •• ib. 

Terruginoui Quartz • 43 

BasaUin, with Earthy Felspar 44 

BasaHtin, with Sideriie •••• 45 

BasaUin, with Silex • „ 46 

Basaltin, with fVacken •.•..•.••..••.. ib. 

BasaUin, with Steatite • 47 

Slate, with SUex • ib. 

S!ate, with Magnesia 48 

Slate, with Lime ....'. 49 

Quartz, with hon % ib. 

Quartz, %pith BasalHn 50 

Quartz, with Slate ib. 

Quartz, with Felspar ib. 

KeraRte, with Chlorite • 51 

Schistose KeraUte and Slate • ib. 

Schistose KeraUte and Limestone . #• ib. 

Steatite, with Argil • • 52 

OUite, with Silex ib. 

Serpentine, with Siderite 53 

Serpentine, with Basaltin • ib. 

Limestone, with Argil ib. 

Limestone, with Gypsum 54 

Limestone, with SUex ••... 55 

Qypsum, with Marl / • 56 

Gypsum, with SUex •.•••....• • 57 

DOUAIH IX. AWOMAX.OVS. 58 

Miagite .«••* t«..f.««*tf #•« 63 

Niolile 74 

CorsUUe .• 78 

Runite ••.•«•.••. ttt*f«.t«tt»*«« 85 



€DIITfirT9* 



Nome V. 

VI- 

VII. 

VIII. 

X. 

XI. 

XII. 

XIII. 

XIV. 

XV. 
XVI. 

xvii. 
xviii. 

XIX. 

• * I « 

XX. 

XXI. 

XXII. 

XXIII. 



Qrqnife, with SappOft 

Lgbrador Rock ••.< 

Kolkmite ••• • 

Topaz Rock 

Jadnt Rock 

Beryl Rock •••••••••••. 

Garnet fiock • 

ShorlRock 

ActmoteRock ••••»..• 
Marble ofMa^qrc^ .t 
if^rble of Ctfff^pan.^*** 

Photphqrite m* 

Globulqr Rqck ••p 

BarytUiftpck 

Sddine ft,gcks ..MifMt 
Bituminotu Rocki ».••< 
Sulphuric Rocks ••••• 
Iron ]^U .••••••••it«t< 



p. 88 
93 
ib. 
98 

127 
129 
ISO . 

ib. 
132 
133 
134 

ib. 
135 
136 
138 
141 
147 
153 
155 



Nome I. 

II. 

III. 

IV. 

V. 

VI. 

VII. 

viti. 

IX. 
X. 

XII. 
XIII. 
XIV. 



Domain X. Tramszlibnt. 

Siderite and Basalt ,•••«. •••••••••4 

BascUtin and BasaU^ or BasaUon 
Basaltin, with Porphyryi ..•••»•••. 
Bcualtin and Wacken ••••••.••,•», 

fVacken and Clay •<•••»»,« ••••! 

Jasper and Keralite •••«••»••#•••#.< 
Slate and Chlonte Slat^ •••..,..«, 
Fehite aad Basaitm •••^••••••••••t . 

Granite and Basalt •••••^•••».»f.,, 

Granite, with iGrfietMMf*«MfM»M« 
Granite and Granitic Pqtpkyry • 

Gnms and Mica Slate •• •« 

Steatite and Asbestos 

Shale and Coal • < 

Fariouf «••«»•. ••# ••••••••. 



163 

166 

ib. 

169 

170 

172 
ib. 

173 

ib, 

175 

ib. 

176 

189 

ib. 

191 

192 



i 



COHTBHT*. 

DouumXI. Dkcohposbd. ' p. 909 

Nomei Dteotnpoted Bataltm ^5 

■ n. D-PorjAyry 238 

■III. D.Blate ; S40 

IV. D. Oitartz ; ib. 

V. D.Keralite 841 

VI. D.fihpar ib. 

343 

S4T 



ibu 

XIII. H.MarhU 250 

XIV. Z>. Alabatter ib. 

XV, D. Coal .. ..^^ ib. 

- " ' Effect! of DecmnposUion »»».-..„«. -SBS 

Domain XII. Volcanic. 268 

None I. CtM^Mict Loea „„.„„„.,».„„„.„...„■..» 313 

II. Vetiadar Lava „„,.„.».».»„» 388 

III. Indtreaed Mud 373 

IV. Tufo 378 

V. PttmUx 428 

VI. Obtidian 443 

VII. Folcanic Intrite 469 

VIII. FfJamie GUaenite SOS 

Dt. Subgtancet Reeled or changed 51S 

Oeneral Ranarki, and Exanqtlet of singular 

Volcano^ 519 

RmacoU ...; «, 645 

yanttonu^ 4 661 

Appendix ,v, S^l 



D6MAIN VII. 

composite: 



This division comprehends the rocks „b®^^ 
which consist of different substances blend- 
' ed together^ and for which no distinct de- 
nominations have been adopted. Manj 
of them have been classed under vague 
naqjfes, particularly that of granite. 

Under the division of Aggregated Rocks, 
Gmelin, in his edition of Linnaeus, has ar- 

VOt. II. » 



DOMAIN Til, COMPOtlTt. 



ranged granite, gneiss, porphyry, amjgda- 
lite, bricia, and sand-stone; and the reader 
will be surprised to find what various and 
discordant objects arc united under.these ' 
vague appellations. Mr, Kirwan has, in 
like manner, two titles of Aggregated and 
es; the other rocks being 
:r the simple substances, 
supplied Brochant with a , 
tf rocks upon the plan of ' 
the Wernerian geology, or, as it is called, 
geognosy, not by the most fortiinate term, 
for the Gnostics have been celebrated for 
sixteen centuries as only pretenders to 
knowledge. But Werner is, on the con- 
trary, the most able and sagacious observer 
that the science has ever produced ; and 
his observations will continue valuable t« 
the latest posterity. His reputation can- 
not be injured even by the insolent tone of 
his disciples, who seem to say, " Are we 
not sons of the wise, and shall not know- 
ledge die with us ?" Daubuisson has how- 
ever treated this subject with great modesty 
and accuracy. The fault in the plan is^ 



that it U theoretic, and constructed upon 
geological ideas of the antiquity and forma- 
tions of the several rocks ; which the suo* 
oessive and general observations of future 
ages may perhaps demonstrate to be only 
local, or erroneous; and which, even at 
present, are very far from being univer- 
sally admitted. Nay, if they proved to 
be infallible, or uncontrovertible by any 
future facts or arguments, still the plan of 
arrangcmient would be improper for a truly 
scientific work, the same substances being 
repeated as primitive, transitive, and se- 
condary, nay, sometimes of independent 
formations; while, in any science, all that 
is required is the knowledge of the object 
collected into one strong point of view. 
Hie denominations are also, as in the in* 
stance of porphyries, bo laji apd vague, that 
the very base and nature of the substance 
are confounded, and no accurate know* 
ledge can arise. In any science, on the 
contrary, it is necessary that the objects 
be classed, and most precisely defined, be* 
fore even a plausible system can be con* 

B 2 



IXmilN VIT. CDMPOSlTB. 



slrticted: the stones must not only te 
hewn out of the quarry, but most accu- 
rately squared, before the temple can be 
erected. But true science and theory are 
so completely opposite, that any attempt 
to blend them has always defeated its ob- 
ject. 

To Mr. Jameson we are greatly indebted 
for a more ample accbunt of the Wernferian 
theory of rocks, which he has illustrated 
with considerable care and attention, so as 
to form by far the most complete treatise 
on the subject which has yet appeared. 
But an infinite number of rocks occur in 
nature, which have neither name nor local 
habitation in the Wernerian system, nor in 
the Huttonian ; though no science can be 
called complete without enumerations of 
all its objects, and in the present instance 
one neglected rock might perhaps suffice 
to overturn a theory. The greatest mis- 
fortune in the progress of human know- 
ledge has always been, that theories have 
been constructed before facts have been 
observed. The theories are indeed useful. 



1 



AOMillil' VII. C0MP08ITB. 



5 



as they stimulate theur admirers to the ol>- 
«ervatioQ of facts ; an^ as Weniet himself 
dbserved to the author at Pari«, a theory 
is useful to concatenate facts, and render 
-them more clear and pleasing to jun audi- 
-ence. Nor, with the modesty of a man of 
real genius, did he conclude his own theory 
to be unobjectionable. 

The intention of this treatise is the accui- *2h?w2?kf 
Tate knowledge of rocks considered in them^ 
selves. As a Zoologist or a Botanist does 
not pcetend to discriminate which plants 
or animals are of early or of later creation ; 
and, in the other branches of mineralogy, 
it is neither the situation nor antiquity of 
the gem, or the metal, that is an object of 
^e science, but the nature and name of the 
substance itself A Gemmologist would be 
ridiculed if he could not distinguish a blue 
diamond from a sapphire, without a previa 
ous acquaintance whether the object came 
from Golconda or Pegu ; and a Metallogist 
must distinguish grey silver ore from antii- 
mony, without knowing either its formation 
or site. In the same manner a knowledge 



6 l»6tf AIM nu MMMUTI. 

of mcks, arisring £rom local relations^ ttu$t 
always be regardeii as empyrical^ and will 
often ptove wholly eitoneous. That great 
^JUg[» observer, Saussure^ found, in the amplfe 
^Gene of the Alps, that he was farther r^ 
moved from the formation of a theory^ 
after the sedulous labour of forty yearn, 
than at the beginning ; that instead of any 
regular plan or order, he found perpetual 
eontradictions, in the assemblage and co- 
alescence of substances, that seemed to be 
wholly remote and dissimilar. '' It may 
well be affirmed,'' says he, ^^ that there is 
nothing certain in the Alps, but their va- 
riety Sometimes the skirts are cal- 
careous, sometimes magnesian. The cen*- 
tres and highest summits are here of mass^ 
ive granite, there of a calcareous mica slate; 
sometimes of magnesian stones, sometimes 
of gneiss : if the beds be considered, h^:e 
they are vertical, there horizontal; here 
their inclination follows the slope of the 
mountain, there quite the contrary."* We 
may add., from more recent obs^vations^ 



Wi9m4m Vtf« ^H^^MfflU 



tbati^e samniite of tii« PyretieeB im» cif » 
/dielljr iwd fi^tid marble ; while the An(k» 
wne chiefly composed of cky, and pour oni 
men of mud. When we compare thei« 
^raod 9cenet with the little mountaJOB or 
hiQB of Saxony, we must regret the per«^ 
vetveneas of fate» which hiB copfined Wer>* 
Ber to such an insjgoificant field of observ*^ 
IjoB. Nor cui the teavek of his di$oiples 
Aifect the question, ix many have cAiaiiged 
timr seatiments upon their visits to Au^ 
yeigne, and other volcanic couotiies; aad 
observatiioas of the gp^eat master alone o>eri{; 
confidence ; for we all know, ftom Hogarth^ 
how Eichardson could read Gretk through 
)m Bon* 

These introductory oba^rvations ve not 
unnecessary in passing to new and ^raod 
divisions of the jnocks, which have been 
trended and confounded under several 
league denominations, but which ace here 
separated into various great assembiagee^ 
lor the sake of more clear detail, and more 
accurate knowledge. 

Under the important Mode of granite, ^^SSSl^ 



S BOM AIV Tft. C01CF0S1TB» 

it has already been explained that felspar 
and quartz, united with siderite or mica^ 
or with both, are indispensable attributes 
of that substance. The mica may pass to 
micarel, or even steatite; and the appear* 
ance of schorl or garnets, not to mention 
the gems, cannot be considered as altering 
the nature of the substance. ' 

But the name granite has, on the -con* 
trary, by Gmelin and many other writers, 
been extended to almost every aggregation 
tiiat can be conceived. Such heterogo- 
neous aggregations are here arranged un-^ 
der the name of Corapositet Rocks ; while 
some, as that beautiful rock called the Cor^ 
sican granitel, are placed among the Anl> 
malous, as departing from the usual rules 
observed by nature. 

The latter six great divisions of the rocks, 
being derived, not from the nature of the 
substances themselves, but from accidence^ 
or circumstances, may^ be called acci* 
DENTiAL, or circumstantial; while the 
former divisions are substantial. The 
phemical Mode therefore, so essential \i^ 



and 
Accklential 



Domain vtu compositb* "9 

the substantial ranks, here becomes foreign 
to the object ; and the terms Structure and 
Aspect, derived from the self-apparent na* 
ture of the stones themselves, would be- 
come yet more improper, as by far the 
greater part of these rocks are even cotn^ 
pounded of various domains, united in one 
mass. 

•The term Domain has been retained, New 
not in its former acceptation, which may 
strictly imply the preponderance or pre- 
dominance of a particular earth or sub- 
stance ; but in a more general sense, 
equally applicable to all the twelve divi- 
sions; that is, merely a continuation of 
the metaphoric language of the Mineral 
Kingdom, Provinces, and Domains. In 
this sense it is indeed chiefly used in the 
first six divisions ; the other implication; of 
predominance of preponderance, being of 
a secondary and subsidiary nature, and 
only a further recommendation of its pro* 
priety. 

But the term Mode implying the che- 
mical mode of combination) which is even 



10 BOHAMH VII. COHfOUn. 

move essential than the aatore wid power 
of the substances combined, as appeam 
from an infinite number of analyses, it cap* 
not be admitted into these new diyisionsi, 
derived from accidential, and not from sub* 
stantial, differences, as has been just men* 
tioned ; isuid the inferior terms being equally 
objectionable, the adoption of a new appel* 
lation becomes indispensable. The word 
None, Nov £ has bccu adopted, as short and con* 
venient, and as applied by the Greek 
writers to the districts of Egypt, the first 
country where chemistry and inineiak^gjr 
appear to have been studied. It is there* 
fore not only of classical authority, but has 
an affinity, so to speak, with the parent 
country of the science, and thus ppesents 
scientific recollections*. The author has 
the greatest aversion to unnecessary ne* 
ology, the chief use of language being to 
be understood, and that the thoughts may 
be accurately perceived, as flowers or firuits 

* The word Id all its lekctioni seen» strictly Greek, and it pro* 
bably only a translation of a Coptic word, especially as Strabo in« 
ferms us that the NonMi were divided into Toparchies. 



HOMB uvBoautw, watt a4B«iT sock. 11 

in a vase of crystal: but when a science 
has assumed a new aspectt like chemistry, 
or is wholly new, like mineralogy, new 
words become indispensable to express 
new ideas. 

For the sake of memory, and easy re- 
ference^ the latter divisions follow the 
general succession of substances in the 
former : but this arrangement must not be 
understood to imply that any substance is 
predominant, as either may have greater 
or less importance in diflferent parts of 
Ihe same rock. After these considerations, 
the proper anrangemeot of the Composite 
Kocks will not be attended with much 
difficulty. 



NOME 1. SIDERITE, WITH GARNET KOCK. 

Siderite and garnet are substances of similar 
origin, alike influenced by iron ; and their con* 
junction is naturally to be expected. Nodules 
of garnet rock may appear in a rock of siderite, 
or the reverse 5 but both are so equally balanced, 
that it would be improper to class them under 
either Mode. 



J £ doMAur rjt. ooufoun. 



HTPONOBCB I, 

« 

. Garnet, in a base of siderite* 

BTPONOMB II. 

Siderite, in a base of garnet 

' Siderite, with garnet rock, from Scotland* 
The same, from Sweden. 



NOME n. SIDERTTE, FELSPAR, GRAPHITE. 

A little chain of rocks, amidst the eternal 
snows of Mont Blanc^ consists of laminar blacl^ 
or green siderite, felspar^ ^nd ^[raphitey with a 
little quartz and mica''^. 



NOME ni- SIDERJTE, UNCTUOUS QUARTS 

PYRITES. 

Mont Broglia, a southern spur of Mont Blanc^ 
is of a stone softer than granite^ being a mixture 
of siderite^ felspar, mica, unctuous quartz, and 
pyrites f. 

• Saoss. 1974. t lb. 911. 



IKIMAiy V|I. COMFOSITS. 1^ 



NOME IV. PORPHYRY, WITH CHALCE- 

DONY. 

The green porphyry, in particular^ sometimet 
appears spotted with chalcedony, so as to as* 
same the form of a composite rock^. Ferber^ 
it has been already .observed, saw numerous 
blocks of green porphyry at Ostia, the sea-port 
of Rome, where they had been disembarked in 
ancient times, and neglected after the empire 
&11 a prey to barbarians. 



NOME V. JASPER, WITH AGATE AND 

CHALCEDONY. 

This curious rock is described, by Petrini, as 
consisting of these three substances, in veins of 
white, green, red, yellow, purple. It admits a 
beautiful polish, and is found at Monte Rufole, 
in the Volterranof. 

* In the noble coUectioo of Beason, at Fflurisy there is a specimen 
joined with pure transparent quarts, which had probably pasted as 
a vein through the rock. 

t Gabinetto Nazareno, Roma 179f , 2 vols. Bvo. ii. S5B, 



14 BoauiN ni. ^^mtomtm 



NOMEVL MICA AN0 ACTINOTE, 

A composition rather uncommon, but found 
in primitive regions, abounding in mica slate. 
Mica and actinote, from Mount St Gothard. 



NOME vn. ACTINOTE, SIDERTTE, MICA. 

A composite rock of delphinite or actinote^ 
greenish siderite, felspar, and white mica^ all ia 
little grains or plates^. 



NOME Vin. QUARTZ, 6IDERITE, OXYD 

OF IRON. 

A rock, composed of quarts, siderite, mica, 
and oxyd of iron ; together with a tabular fel- 
spar, which he calls sanidin€f a substance in silky 
tufts, which he calls desndncy and another reseoir 
bling spinel, which he calls spinelan^ was dis- 
covered by Nose on the banks of the lake of 
Laach, near Andernach. See \m mineralogy of 
the mountains of the Rhine, quoted in the /our- 

• Sau88. § 1803. 



nal de Physique for August, 1809. This sin* 
gular rock might be called Nossite, from the 
name of the discoverer. 



NOME IX. QUARTZ, SCHORL, AND 

STONE. 

This composition appears in the in6nite va*: 
riety of the Alps. 



NOME X. QUARTZ, UME-STONE, AND 

SAUSSURITE, 

Also found in the Alps. Besides Saussurite 
(that is, basaltin with a notable proportion of 
magnesia), quartz and schorl may also be found, 
conjoined with steatite and other magnesian 
rocks. 



NOME XL FEI^PAR, QUARTZ, GARNETS. 

,This rock sometimes constitutes mountains, 
and may be found in Switzerland, Sweden, and 
Scotland. 



Il^ i>6MMa nu COMMtlTSi 



iiOME Xn. FELSPAR, QUARTZ, TALd. 

This noble irock contains plates of splendid 
talcy varying in size from half an inch to manjf 
feet in diameter. It chiefly occurs in the Ura- 
lian mountains, whence talc has sometimes been 
cdled Mascoty glaiss. 



NOMElXm. FELSPAR, nBROWS SlDERTTE. 

A rock in confused veins of felspai', white 
mica, and green fibrous siderite *« 



NOl^EXIV. FELSPAR, CALCAREOUS SPAR. 

A rock of great rarity, and seldom occurring 
except in the ejections of Mount Vesuvius, 
which also affords a composite stone of felspar, 
garnets, and actinote ; with Other aggregations 
on which it would be tedious to enlarge. Nor 
is it certain that they occur in such masses as 
to constitute rocks. Many may be mere para- 
sites or vein stones. 

• Sauas. $ 1369. 



OOHAIM Vlt. COMPOSITB. 1/ 



NOME XV. JAD, SCHORL* GARN^TTS. 

» t 

i 

' A raekt which Saussufe caUtf a mixt^are of 
jttd, sparry schorU and.mastiye garaert. It takes 
a fine! polish, and i(^ large spots of red^ green, 
and ydloWj form a beautiful effect*. 



KOMEXVI. GRANTltB AND OHALCEDONY. 

Chaloedony was chiefly found in amygdalites, 
and by some supposed to be of yolcanic origin. 
Saus^oce | discovered this curious and important 
rock iiear the city. Qf Vienne, in Daupjhiny. 
On examiniqg the stones employed in byilding 
a peasantV cottage^ he was astonished to. find 
that' most of them were elegant chalcedonies, 
more or less translucent, and mingled with leaves 
of a beautiful yellow pyrites. Observing that 
granite adb&ed tapiapy of these fcagments, the 
rock was explored, forming the adjacent bank 
of a rivulet called, Bougelai, In some places it 
filled^up the accidental seams of the granite, 
and in others formed nodules completely en- 
veloped in that substance* The most common 

• S 145. . t { 1634. 

VOL. II. . C 



tt POUAIK Vll. CeiffOSfTB. 

colour of the chalcedoBy is a bluish grey; but it 
also appears of a yellowish white, and often co- 
vered with ferrugiDoiu ru^t. Sometimes there 
are zones, concentric and in festoons, of a paler 
colour. Th« fraoturd is Torious, sometboes oni- 
form, sometimM scaly, sometimes a little con* 
choidal; and its hardness te such that the file 
cannot touoh it. It is coeval with the grapite^ 
for nodules of granite may be found in the chal- 
cedony, as well as the contrary. These granitic 

ii(HJhik$ cootain vet? linteimqa. but ^imdun^ 

felspar, yellow or reddish, and quartz, of which 
the aspect sometimes approaches that of the 
chalcedony. The pyrites is interlaced in a re- 
markable manner, being in plates nearly regu- 
lar, a quarter of a line in thickness, and about 
five or si& lines in length. These plates cross 
each other in certain places, in every direction. 
Each of the plates is included in a kind of sal- 
band, of a breadth equal to that of the phtte, of 
k deeper coloured chalcedony than the rest of 
the stone. The pyrites is of a pale brass co» 
lour, and granular fracture, but decomposes in 
the air; so that its beauty only becomes ap- 
parent on a fresh flracture*. 

* Smarare ftfterwafdt dUcofcnd aWMteiiM olT ahalMtony im 
the granitet and gneiu of the plains, and particularly in the ancient 
Bourbonnois. S«o taia v* p« xi. 



In a subsequent journey Saussure also dis- 
covered gneiss, its thin leaves alternating with 
thicks oi: tbimier hw€» qf .cbajce(jktfx)r« 

mPPOMOlCB 1« . 

Chalcedony in granite. 

HTPONOMB II. 

Nodules of granite in chalcedony. 

Mkronorhc 1. Gneiss, alternating with chalce- 
dony. 



• 1 



JfOMS XVU. OMNITS, WITH 9(tH01t£ 



\ • 



A granite, from Bamfshire, Scotland^ of red 
felsjpar^ apd blqish fat (juart^ in large ^rains^ 
brond p^t^sQf wicarel of » brilliant yellow, with 
black schprl io prisws oif four lines in diameter, 

There «re j^Up.patcbes pf f^^ 



• • 



4 A 






J • 



\9 



c S 



520 1>OIIAIV Vlt. -COIIPOSfTB* 



NOME XVIII. GRANITE AND UME-STONE. 

This mixture, likejnoat of the others, appears 
in the Alps. 

HTPONOMB I. 

Granite, with limerstone.. 

Micranome 1. Gneiss, with lime-stone. 



NOME XIX. GRANITE AND SLATE. 

Slate, by some called argillaceonsjchistai, is 
sometimes found blended with granite, though 
ifi general it rather se^vs to form a distinct line; 
and It commonly rests on granite, as being of i^ 
tVeiiisor more recent formation. The veins of granite 
slate. that run through slate have afforded matter of 
discussion to various theorists, who thence argue 
that the granite is of more recent fohuation, of 
at least that they are both coeval. It has been 
affirmed by some, that what is called giranite^ in 
such instances, is of an imperfect form, being 
either granitel of two substances, or the mica 
not in its usual state of crystallisation* Granites 



noum XIX* 0XAKirc av0 «.atb« ^l 

of quite d new fermatiou barre been indicated bj 
Sananire^. In describing the moontains which swmmet 
bound on the north-west the valley of ValorBiiie» 
he mentions that he foimd a mountain cofiorpoeed 
of biff roche de ccmCf which is sometimes basalt^ 
.generallj baialtio» sometimes basanite; s^ime- 
times magnesian basaltan, here called Sauasurites 
and sometimes a coarse slate, or argitlaceous 
schistos, which seems here to be the casejv 
^* On oboerving t\M roche de come in the spota 
•where it coalesced with the granite, I saw veins 
of different breadths filled with a granite, which 
was fbimed and raonlded in their interior. The 
largest of these veins is about three leet in 
breadth, cutting at right angles the planes of the 
lajers of the rock, which it traverses; and the 
uncovered part thove the rest is about seven or 
eight feet in length. The sides of this vein are 
regular and parallel. The granite which fiHs 
this vein is composed, like that of the mountain 
to which it adheres, of grey quartz, white fel- 
spar, and brilliant grey mica. This granite 
presents little even slits or seams, rather indi- 
cated than real, crossing each other in different 
directions ; which seems the effect of a begins 

• i 699- 601. 

t The cometM ^jm/m ofWallerius is hornblende slate, or slaty 
ftiderite. 



JSB oohahi Tit« coMBosnri. 

lftft«^ recM; aad irikBh sbinr the tendency) 
eomnidii in this boi« of Btone^ t^ diiride itsdf int6 
A^gmentb of 9i^m 6ittet« 

"^ Atove and beneaAi thit tein there amnthert 
diore MMPOW) ione in pttrticvlmr^ whieh k not 
^AlWf^ half M iiich in bmulth^ and iri prdoagw^ 
lifte the fottn^, for to. Bpiu^e of cieyen or e^^ 
Ktet. Some of the litde veins shovr that the 
hedd «f Uife f^A« ^(^ vome hate sehcMedt <n* sunk 
^inisquiUly^ teince the granite |>enekFated into it) 
<br th^ ^eem to be suddenly internipted^ and to 
t>egtn awew a litde higher or a litde 1otvtar« The 
t>road6St vein smws also te hart yidded a Mttle 
' $n some ^te. 

*< Th€ee teiM of g^ratnitev which vera then 
^ew to me^ a^peair to throw ii|ght on the fonM^ 
1!k)ii of that ^«onO. fbr to any mMi a tttdo 
ttetiMi in ttSaeralogy^ tit Is ahnoet dememstfldyle 
lAiat thift gtanite has been fbMned in these vems, 
hy mero fiitr alMti of ilio wateni) which, in de- 
^scendmg fwth the mouMsMi of gramite, which 
tiang^ oror these «chistoee rOGk6> bf oaglit down 
the •eltemdffts tif «kat OKraataiis whioh tiiey do- 
)posited atnd orystilKved in tbtee fissumfk When 
iHie finds the slite Of a tmMlit, or of a ^siate, filled 
with spar or quartz, one decides, without hesi- 
tation, that these foreign bodies, or parasitical, 
as Linnaeus calls them, have been brought by 



NOUS XIX* . OXAKITC AMD ftLATB. jU 

tihe WBtefSy and cr3nstallited m iiktst sUH^ Since 
then the element* of. granite we all capaUli of 
huihid crystallisation, why, as the circumstances 
ane the same, should one hesitate to adoMAY* 
ledge, that it has beea also dissolved and ctyt^ 
tellised through the medium of water } 

^ I thought then that I had made a great step- 
towards the knowledge of the formation of gra^ 
Bite, when I saw with so much <deamess that 
nature could form it by the mere a£sistance of 
water. My only regret was, that the proof of 
this truth was concealed in the centre of the 
Alps, in a spot so little accessible to the greater 
part of the lo^rs of lithology* 

<< But I had, towavda the end of the same 
year, the pleasure of finding, the phenomenon in* 
a place well frequented^ and of cMy aocess, 
since it is at the foot of the walls of the city of 
Lyons. If, without the gate of the Red Cromh 
you descend to the Saone, by a path whiob runs 
under the walls of the city, you will see on the 
fight, a little beneath the fort of St. John, banko 
of sand, the sides of which are open to the air.^ 
Under these Bands are schistose rock^ cojiiposed 
of white quarte and brilliant mica^ sometimes 
red, sometimes blackish. The layers ans ahnost 
perpendicular to the jiiCHrizon, for they form with 



24 OOMAm Til. COMPOSlTik 

it an ^ngle of 80 de^e^ inclining towatdff die 
west, and running from north to south* 

*^ There I found a Tein of granite 21 mchea 
in breadth) and uncoTered for a length of about 
18 feet. This vein, of which the sides are pa«' 
rallel, traverses the layers of schistose rock, un<^ 
der an angle of dO degrees, and forms with the 
horizon an angle of ^0 degrees, with the same 
inclination as .the layers. The granite! which 
forms this vein has shrunk, like that of Valor- 
sine, with some rectilinear fissures^ whichcross 
each other irregularly. There are seen in the 
« same rock other veins of granite, of a less con- 

siderable size, the largest being parallel to that 
which I have described, while the others run' in 
an oblique direction. 

. *^1 observed simile veins in the schistose 
rock, at the foot of the wall <^ the city, and 
under the path which accompanies that^walL 
One of them, about fourteen inches in breadth^ 
is perpendicular to the horizon, like the layers 
of the! rock. It passes under the widl» and rausl 
enter into the city. Near the Saone, and within 
the city, is a quarry of granite, which was 
wrought at die time I made my observations. 

** In fine, I made at Semur, in Auxois,an ob« 
servatton analogous to the preceding, and which 



NOMB-UX. OJUNITB MUD 8LATB. g5 

eoafirms the same triith that granite may be 
formed in the water, by the simnltoneoiis crys* 
taliisation of two or three kinds of stone. The 
granite rook, on which this town is built, na« 
titrally divides itself into large masses, with 
plane or fiat sides, and these masses are here and 
there separated by crevices of a certain breadth. 
I. found in these crevices parcels of quartz, fel* 
spar, and mica, mingled as in granite, but. in 
far lafger grains, there being bits of an almost 
tram^rent quartz, two or three inches thicky 
traversed by leaves of mica so large that they 
might be called talc, or Muscovy glass; and 
the whole intermingled with large pieces of red 
felspar, like that of the granite, and confusedly 
crystallised. It could not be doubted, on seeing 
these heaps of large crystals^ that tliey are the 
produce of the rain waters, which, passing 
through the granite, have dissolved and carried 
down these different elements, and have depor 
sited them in these wide crevices, wher^ they 
are crystal] ised, and have formed new stones of 
the same kindi The crystals of these new grar 
nites are larger than those of the ancientt on 
account of the repose which the waters eiy oyed 
Ml the Hifiide of these reservoirs." 

Such are the riemarks of this great observer^ 
who proceeds to argue that granite was ori« 



gtnally formed in the anoieilt ocean that eovered 
the eitfth ; that it is disposed in beds or layers^ 
though sometimes very thick and difficult to 
discover, especially as those of the low^er moun- 
tains are apt to split into fragments, either rhom- 
boidal, or at least with flat sides, which he 
ascribes chiefly to the mixture of argil in one of 
his pUrres de came ; and as he mentions tiiat it 
is fiequent in these granites, he must mean horn- 
blende or siderite : adding, that the absence of 
marine bodies in granite, gneiss, &c. affords no 
proof that they were not formed under water» 
tiie most ancient ocean probably having con« 
tained no aiiimated matter, as a pure infusion^ 
for example, only displays animalcules at the 
end of a certain time. 

Scarcely a phenomenon in orology has escaped 
Saussure, if his work be accurately read, or ra^ 
ther studied, as it well deserves; and what is 
regarded as a new observation may be here 
found, namely, the elevation of the veins of 
granite above the clay«>slate, which, in his vnde 
field of observation, he simply accounts for by 
the subsidence, or shrinking, an accident com* 
mon to clay; not to mention the greater soft* 
ness of the substance, which may mott easily 
be worn down by the weather. Nor is it incon- 
ceivable, on the other hand, that those, veins 



ifaiaf be as lacMt as tlie Mtauht gtanite ; that 
sub0lMi«e soBMtiaies rising into tiatnral walkt » 
in Cornimll t Wp in the gttmt vatiqmty <£ the 
earth, the veins majr bmt been fonnod in a 
softer granitic substance (more compact veins 
and nodules being observable on a small scale), 
which irfWrwards wasted away^ and its place 
was supplied by the clay^slate. 

■ 

HTFONOMB 1. 

Granite in slate. 

Micronome 1. Slate in granite. 



NOME XX- GWEISS, WITH SLUE SIDE- 

RITE. 

Near Breuil^ Saussure obserml a gneiss full 
of garnets, the surface beifj^g incrustated with 
little crystals of a beautiful steel blue, oblong, 
irregular, opake^ very brilliant, striated in the 
longest direction, frequently porous in that di- 
rection, and with difficulty scratched by a knife 
when the streak is grey. The fracture laminar, 
equally blue and brilliant; and they are easily 
fusible under the blow-pipe into a shining black 
amel, attractable by the magnet, although the 



2g DOHAIV vtu oomosiTE* 

original substance be not He adds, that aU 
these properties cfaaracterise some kinds of 
hornblende, the only singularity of this 
its blue and brilliant colour^. 



. '. * 



NOME XXI. CLAY, SPATHOSE IRON. ^ 

ft ■ * * 

A composite rock of clay, spatbose iron, and 
another sparf. 



NOME XXn, SERPENTINE, WITH UME- 

STONE. 

Some of the most singular compounds with 
lime-stone occur in the Pyrenees, where that 
substance forms the chief summits. The inter- 
mixture of lime-stone, or of calcareous spar, with 
s(erpentine, is there not uncommon. 

Some of the noblest marbles, as the verd- 
antique, and that lately discovered in Anglesea, 
consist of serpentine mingled with carbonate of 
lime ; but the magnesia is so preponderant, and 
its nature so predominant and characteristic, 
that such are arranged in the Talcous Domain ; 
not to mention that the union is too intimate to 

• § 8S74. t $ 1446. 



VOMB XXIll. LlMS-STOlfl^ WlTtt OAKMBTt* 99- 

class them among the Compoeite Rocks^ which 
are mostly only coherent» the substances form- 
il^ in distkict accretions. 



I. 

Dark green serpentine, with ffey Ume-stone, 
from the Pyreiiees. 

« - ■ t « * I • « 

Micronome 1. The same, with red calcareous, 
spar, from the same. 



NOME XXni. UME-STFONE, WITH OAR- 
NETS. 

» 

This curious mixture also chiefly occurs in 
ihePyrenees, 

Light brown lime-stone^ with red garnets, 
from the Pyrenees. 

• ■ - • * 

HYPONOMX I. 

• * 

With amorphous gciniet 



. • 



., HTfOHOMB II. 






5or p^MiiK mu c^iNwpsi^ik 



NOME XXIV. UME-STONE, WITH STEA- 

TTTE. 

Tirey^ one of the western isles of Scotland, 
pregents a wHte marble With y^lom spolist, sap- 
posed to be steatite. 

In the same interesting isle marble and steatite 
are reciprocally intervemed. 

HYPONOBCB I. 

M vblq? vitii v^m oi affile. 



HYFONOMB II. 

t 
I 

Witli spots. 



:•; • 



i ' : 



NOME XXV. LIME-STONE, WITH OLIVINE. 

Olivine, before chiefly observed in lava, and 
basalt, is also found in the imcaceous Kme-stone 
of Mount Somma, of which Vesuvius may be ' 
regarded as only a portion. Breislak has, on 
this occasion, given some itoflM ioCBilllMton 
concerning olivine and chiysolite*. 

• i. 160. 



NOMS XXV. LIXB*BTONB> WITB OLIVINE. 91 

1. The soft chrysolite, or asparagus-stone of oiivmeand 

• chrysolite* 

Werner, is a mere phophate of lime, analysed by 
Vauquelin. 

S. The chrysolite of the jewellers is a greenish 
oriental topaz. 

3. The common chrysolite, or peridot of the 
French, analysed by Vauquelin, contains*-mag- 
nesia 50, silex 38, oxyd of iron 9. This is also 
the chrysolite analysed by Ktaproth. 

4. Olivine^ called by some volcanic chrysolite,* 
has also been analysed by Klaproth, and though^ 

it contained rather more silex and iron, as ' the • 
proportions will even vary in different specimei^s 
of the same identic substance, it must be re- 
garded as the same with the peridot. There is 
also found a tincture of lime in olivine, which 
may proceed from the gangart* These gems 
are remarkable as alone belonging to the Mag- 
nesian Domain. 

The jacint of Vesuvius, the Vesuvian of Wer- 
ner, is also found in the lime-stone of Sommaj 
and it has been discovered in Siberiai and in the 
mountains of the Grisons. Melanite has also 
been found in the calcareous rocks of Somma. 
But the lattej subs.tance, is only to be regarded 
as imbedded in the rock, and strictly belongs to 
gemmology. 



3£ OOMtAIN VII. C0MF08ITS. 



NOME XXVI- LIME-STONE, WITH ACn. 

NOTE. 

l%r^ii»rbie. . The beautiful rose-coloured inarble of Tirey 
not only contaius large crystals of siderite, some- 
^imes an inch and a half in .lengthy of a black or 

very dark green colour, but numerous other 

, ' ■ • 

crystals of a lighter green^ which every candid 

* ■ 

observer would allow td be the same substanccj 
with a slight diversity of colour. It seems noW; 
to be universally allowed by the most skilful 
mineralogists, that actinote is only a diversity o( 
siderite, with a greater portion of magnesia, an 
earth which singularly affects the green colour. 
But this actinote must not be confounded with 

4 % 

the epidote of Haiiy, a mistake into which many 
writers have fallen, whereas the latter contains 
no magnesia, and a greater quantity of lime*. 
Under the epidote be ranks aoisite, so called 
from Baron Zois ; and the scorza, or greenish 
sand, found near Muska, in Transylvania. The 
sahlite he ranks under pyroxene, or augite« 
These substances are mentioned because they 
have been supposed to have been found in the 
marble of Tirey, which sometimes also presents 

* See hit TM99.VL comparaH/, VuU, ISO9. Sto. notes 51, 66. j 



KOMB XXVf. LIMB-STOMS^ WFTfC 'ACTINOTE. 33 

a substanca resembling red galnets^j or pefbaps 
they are only altered by the gangart^ and migiit 
be found upon analysis ta correspond with those 
fpund in the lime-stone of the Pyrenees. Thus 
the singular appearance of the flint discovered 
at Menil Montant, near Paris, and .ivhich re* 
sembles pitchnstone, probably only arises from 
the soft and unctuous marl in which it is al- 
ways found. This important observation may 
be^said to have escaped all writers on mine- 
ralogy. 

It is remarkable that marbles similar to that 
of Tirey occur in Scandinavia. A northern mi- 
neralogist, ' Mr. Neergard, observes that there 
are, in all Sweden and Norway, only two quar- 
ries of marble which are wrought 'i^. 

'< That of Fagemich, in Sweden, is situMie 
between the two little towns of Norkioping and 
Nykioping, and about thirty leagues from Stock- 
holm. It belongs at present to Mr. Eberstein 
of Norkioping, and to Baron linger, w%o pur- 
chased it from Count Gyllenberg for only 
200,000 fraucs, on account of its bad condition. 
This marble, which is white, with veins ofgreen 
talc, the fracture brilliant, began to be wrought 
aboLUt a hundred and fifty years ago, in the reign 

* Brard^ Tntit^ des pieries^ Paris 1808^ 8to. ii. 444* ' 
VOL. II, D 



34 eoMAtir tii. oomposits. 

ef Claeea Christma. The space irhere it is 
faond it about 2000 fbthoms in length, but its 
breadth is inconsiderable. They make of it 
tombstones^ slabs for tables^ vases for butter, 
sah cellars, and mortars ; and the sale of these 
differait articles amounts annually to about 
20,000 francs. There are magazines of it at 
Stockholm, at G<ri;tenbnrg, at Carlskrona, and at 
Abo. The manufectory employs about twenty 
workmen, who receive each two iivres ten sous 
(about two shillings) daily; and its position is 
fine and well adapted for working, as it is near 
tbe Baltic sea. 

'vThe marble^uarry of GUlebeck, in Nor« 
way» is seven leagues distant from Christiana $ 
but as the m«^ble which it furnishes is saturated 
with a great quantity of pyrites, it generally be- 
comes decomposed in a few years. The great 
church of Frederick, at Copenhs^n, which is 
unfinished, is built with this marble* I have 
often seen some pretty tablets of it, which con# 
lataed garnets^ and a green substance called ac<» 
tinote." 

Hie Tirey marble seldom takes a fine polish. 
Perhapa by a mill> or a steam-engine, and high 
firtctiDii with putty, tiiis defect might be reme« 
died. But granite itself seldom admits a perfect 
polish, dwing, as in the Tirey marble, to the 



WOMB XXYiU MARBLB, WITH AfBBSTOS. 35 



I 



hardness of the ingredients, 
oar artisans, only accustomed to soft marble 
seldom possess the instruments necessary for 
hard substances; and a laudable cl^ange in the 
public taste can alone drive them from their 
routine. 



VOfKE XXVn. MARBLE, WITH ASBBSTOS. 






Tll^bncoaimon mixture is found id Ihie-Fy- 
reneesy and, it is believed, in Sweden. 



I. 

» - r 



Marble, ivith asbestos. 

Micronome 1. Asbestos^ in calcareous spar. 



p 2 



DOMAIN yin. 

DIAMICTONia 



XHESE rocks, in which the substances 
may be said to be chemically combined, 
form the most difficult province of the 
whole science, and might deserve a sepa- 
rate treatise, like the Cryptogamia of the 
Botanists. Siderous earth, for example, 
may be found so intimately and equally 
combined with ^e siliceous, that the rock 



DOUAIH Till. DtAHICTOKIC. 



Bergman. The aggregated stones of Kir- 
wan comprehend granite, gneiss, porphyry, 
aroygdalite, sand-stone, and other sub- 
stances, visibly compounded of various 
materials; while bis derivative stones he 
distinguishes from aggregates by this, " that 
the associated ingredients are not visibly 
distinct, or at least require microscopes to 
render them so." He adds, that a deriva- 
tive stone may be denominated from the 
Bpecies (that is, the Mode), which still pre- 
dominates; but if it participate equally of 
both, it may receive its denomination from 
either. The siderous, siliceous, and argil- 
laceous earths, form the most frequent 



jDg BOMAIir VIII. DUMICTOariO. 

ccunbiiiations ; while those of calcareous 
earth and magnesia are far more rare. In 
his Geological Essays he observes, that 
stones are either original, as granite, or de- 
rivative, as sand.stone ; while, in his mine- 
ralofiry, he has classed sand-stone, alone: 
with^nite.aa.ong«.e.gg«g^. 

The appeUation and distinction are in 
fact alike fallacious. That a red sand- 
stone may be derived from the detritus of 
a red granite, may be justly admitted; but 
this afibrds almost the only example of a 
real derivative stone. And the intimate 
combinations of which Mr..Kirwan speaks 
are so far irom being derivative, that they 
often belong to the most original and pri*- 
mitive substances. But when Mr. Kirwan 
published his valuable system in 1794 (and 
the last edition is merely reprinted), the 
knowledge of rocks was extremely con*- 
fined, and regarded only as an appendage 
to mineralogy, instead of forming a grand 
and distinct science, a rank to which its 
dignity and importance authorise it to 
aspire. 



NOME I. •IDSIITB, WIVB tllAX. * 9§ 



The term diamietcnk, derived ffotn the 
Greek, implies that two or more substances 
are so thoroughly mingled, or, in the lan- 
guage of chemistry, so intimately com- 
bined, that the rocks cannot be arranged 
under either Domaiui either from prepond* 
erance or predominance. 

As this Domain depends especinUi^.ttpon 
the guidance of chemistry, it may be dkosen 
to honour the names of the chief ch^mists^ 
here arranged in chronological order, from 
the most ancient to the most modem 
times ♦• 



NOME I. SIDERITE, WITH SILEX* 

[Herv iTE, from Hermes, the supposed founder 
of chemistry, which certainly originated in 

Egypt) 

Of this kind is the celebrated rock abore 
mentioned, io which atoms of quartz are ioti<» 
mately blended with atoms of siderite ; but in 

* A curious «ofount of tb« ancient chemittSy or akhemiitt, vaa^ 
be found in the Hiitoire de la PkUoiophie Hermetic of liCnglet 



40 DouAin vuu ]>iAMicToina 

some poiticms, as usual in the infinite variety of 
nature, the quartz will preponderate, and some* 
times the sidente. Saussure's* description is as 
follows: . 

Giuoedroek* «« We now arrived at this singular. rock, which 
formed the object of this excursion. Its supe- 
rior surface inclines to the east, under an angle 
of 43 degrees. It is this surface which is pa- 
lisb^, and in so bright a manner, that it forms 
a penfect mirror. In some parts it is perfectly 
plariej so that tables might be cut from eight td 
^en.feet in lengthy and of a. profioiftipnal breadth:; 
)vhile in other, parts it is a little undulated, but 
still equally polished. It is here veined like a 
marble; there marked with angular spots, like 
fragments enchased in a base. The colour va- 
ries, the ground being commonly brown or 
blackish, and' the spots of a pure white; some- 
times, hpwever the gro.wd itself is Tvhite. This 
stone is very hard,- yielding abundant sparks 
undei! the flint, whence the polish resembles that 
of an agate or a jasper, having more splendour 
than that of marble. The white parts are un- 
dbubtedly of semi-transparent quartz^ infusible 
by the blow-pipe, but dissolving very speedily^ 
and with a lively effervescence, in mineral alkali. 

^'■' The black parts appear of two kinds; thosq 

which are nearest the polished surface losing 



NOMB in SIOBSITB^ WITH MICA. 44 

their colour under the blow-pipe^ and becoming 
white like the former, but without any further 
change ; and they also melt with effervescence 
in the mineral alkali, without colouring it in the 
slightest degree. But in the interior of the stone 
are found black and soft parts, which, when 
moistened with the breath, exhale an odour of 
clay, and melt under the blow-pipe. The black 
polished parts are therefore also of quartz, or, if 

w 

you will, of jasper, coloured by some particles 
of the black pierre de come, which is found in 

4 

the interior of the rock." 

He supposes that the most natural explanation 
of the polish is, that it arises from crystallisation 
on a vast scale, as it is accompanied with streaks^ 
like those comnion in crystals of quartz. 



NOME 11. SIDERITE, WITH MICA, q 

[Democrilite, from Democritus the philo^ 
sopher, B. C. 480, who made many experiments 
on plants and minerals.] 

The particles of siderite are sometimes inti* 
mately blended with particles of mica, * 



4d SdMAIH Till. PIAMICTQNSC 



O 



NOME ra. SIDERTTE, WITH FELSPAR. 

[FiRMicjTE, from JuUus Firmicus, who floo* 
rished under Constantine I. and first mentions 
mlchemy^ '' sdentiam akhemia*.''] 

uravstein. The gfaustein of Werner is an intimate mix- 
ture of siderite with white felspar^i which last 
often predominates. According to Mr. Jame- 
son f it contains olivine and augite,!ike basaltin* 
and sometimes passes into that substance. It is 
frequent near Vesuvius, and in some other parts 
of Italy. 



\ 

NOME IV. SIDERTTE, WTTH EARTHY 

FEI^PAR. 

[Stnesxte, from SynesiuSy one of those Greek 
philosophers, in Egypt, who cultivated this 
science, A. D. 400.] 

This combination has been described by Saus- 
sure. The mixture of siderite and felspar, in 

* Matheseoe iii. 15. Orosius first states, that piocletian burnt 
the books of the Egyptians. 

t iiuigcft. 



NOMB V. 7SR»UOtMOUS aUAtTZ. 43 

basalt and granite^ may be considered as a gra- 
dual approach to this intimate combination. 



NOME V. FERRUGINOUS QUARTZ. 

[ZoziMiTEj from Zozimus, one of the chief 
Greek philosophers of Egypt^ who wrote on al- 
chemy, A. D. 420.] 

Near Sallenche^ Saussure observed a rock, 
with protuberances, of a lively red, like cinna- 
bar. When broken with a hammer it proved to 
be a micaceous ferruginous rock, with irregular 
nodules of quartz, tinged red with iron. 

When the tender or micaceous part of this 
stone was exposed to the flame of t|he blow-pipe, 
it melted into a greenish and almost transparent 
glass; but the hard and quartzy parts scarcely 
suffered any change, except there were some 
free ferruginous particles, which in that case 
melted, and formed a black and brilliant dross, 
on the surface of the stone ; but when the co- 
louring part is intimately combined with this 
stone, it remains red and untouched*. 

* Saius. 1134. 



44 OOMAIir-TItl. OIAHIOTOBIC. < 



NOME VI. BASALTIN, WITH EARTHY 

FELSPAR. 

[Gebrite, from Geber (Abou Moussa Gia- 
BER'ben Haijam a1 Sofi), the first of the Arabian 
chemists, A. D, 830.] 

Saussure afterwards describes another singular 
diamictonic rock, which he found near Mont 
Blanc. 

" Fragments of a remarkable rock are after- 
wards observed; its colour is red, inclining to 
violet, like the dark lees of wine ; it is. not schis- 
tose, but in hard and compact masses ; yields 
fire with steeA In the fracture its grain appears 
a little scaly ; and if observed with a lens, it 
is found mixed with dull grey parts. These 
parts, softer than the rest of the rock, become 
white when scraped with a knife, and are un- 
questionably of pierre de come. As for the hard 
and reddish base, it seems to be of the same 
nature with that of several porphyries, which 
have been improperly classed among jaspers. 
The blast of the blow-pipe discolours and melts 
it, though with difficulty, into a transparent 
glass, strewed with small bubbles. This cha« 



VOUE Til. BAWMJUtlV, Vmn tfimtXTS. 4S- 

» 

racter belongs to felspar, and some kinds of pe* 
trosilex ; but as this rock has ngt the fracture of 
petrosilez> I think I ought to look upon it as 
the earth of uncrystallised felspar. Fragments 
of this rock are found very plentifully spread on 
this road. I had not time to ascend to the rock^ 
frdm which these fragments are detached, but I 
do not doubt, but that these rocks are situated 
like those of pierre de come^ which I have de- 
scribed in the preceding paragraph. Since I 
^ave become acquainted with this rock, I have 
found rolled pebbles of it in the environs of Ge* 
neva ; so true is it, that we find in proportion to 
what we know/'* 



/ 

|f(»fE Va. BASALTIN, WITH SIDERIHt 

[Rhazite, from Rhazesj A. D. 900.] 

This combination b far from uncommon, and, 
may be found in most basaltio countries^ It 
sometimes occurs even in schistose siderite. ^ 

Basaltin, with siderite, from Saxony. 

The same, from the Faroe Isles. 

•J1136. 



46 aaii4iii tiik BUMierovic. 



NOMB Vm. BASALTIir, WITH SILEX. 

[£»KNiiiviTS* from E^ Sina, or AvtoeDiia* 
A. D. lO^OO 

The siliceoQs part is generally felsite. $ar 
saltin sometimes passes into a more siligeoua 
substance, which, in the north of Ireland^ is 
schistose^ and contains ammonites. It i^ sup«» 
posed to be a detritus of the basajtin^ i|iixe4 
with siliceous particles in the primeval waters. 



NOME IX. BASALTIN, WITH WACKEN. 

. C A£B£&TXT£, fiY)m Jlbertui Magnus, A. D. 
1320.] 

This combination sometimes occurs in Sax- 
ony, and other basaltic countries. But far more 
generally the basaltin Is separated from the 
wacken by a positive line. 



snmxs s. xi. 



4# 



NOME X- BASALTIN, WITH STEATITE. 

[Bacon IT£» from Boger Bacon^ the greatest 
chemist of the middle ages; flourished A. D. 
1240^ 

This differs from Saussurite^ or magnesian 
basaltin^ because the particles of steatite may 
be partly distiuguished by the naked eye. It 
is found in the isle of Mull^ and in some other 
Countries. 

BYPONOfifX I, 

With steatite disseminated. 

HYPONOMB II. 

The same, with globules. 



NOME XI. SLATE, WITH SILEX. 
fLuLLiTE, from Raymond Lully, A. D. 1300.] 

This kind has been described by Mr. Kir- 
wmn*. Sometimes the quartz seems the most 



• ; 



1.381. 



48 I>OMAltr VIII. DIAMICTONIC. 

considerable part of the combination ; but the 
rock still preserves the slaty appearance. 



NOME XII. SLATE, WITH MAGNESIA. 

[Valentinite, from Basil Valentine (his real 
name see Dufresnoy, i. 229)5 A. D. 1410.] 

This substance is commonly to be distin- 
guished by its unctuous or silky appearance. 
The magnesia sometimes assumes the form of 
small scales, as at Holyhead, where it is also 
sometimes invested with a crust of foliated steat- 
ite, and sometimes includes masses of pure talc 
and amianthus^. The same interesting spot 
likewise presents schistose siderite, penetrated 
with talc or micarel. It has commonly layers 
of quartz between the plates of siderite. 

HYPONOME I. 

Level. 

HYPONOME II. 

Undulated. 

• Kirwan i. 388. 



Nouti xin. XTf.- 49 



NOME Xm. SLATE, WITH LIME. 

[PALfssi^E,* froin Bernard Palissy^ a potter 
of surprising genius and intuition, A. D. 1580*.] 

This mixture is found where the isiate joins 
the lime-stonei either primitive or secondary. 

HTPOXOaiB I. 

Slate, containing lime. 

HTPONOME II,'. 

■ 

lime-stone, with particles of slate. 



NOME XIV. QUARTZ, WITH IRON. 
[Helmontite, from Helmontj A. D. 1620.] 

The most remarkable kind, the eisenkieseL or 
iron-flint of the Germans, is only found in veins, 
and belongs to lithology, or the study of the 
smaller stones. But rocks of quartz and keralite 
sometimes occur, intimately combined with iron, 
in whole or in part. 

* See his works, pobliflhed by Faujas in 4to. 
VOL. II. E 



50 BOMAIII VIU* m^MiCTONIC. 



NOME XV. QUARTZ, WTIH BASALTIN. 

[TomBicjSLLiTE, from TorriceUU A. D. 1640.] 

This is a scarce rock, and may rather be re- 
ferred to tiie Aiixtare of siderite with qoart2.< 



NOME XVI. QUARTZ, WITH SLATE, 
[Glaub£Bit£9 from Glauber^ A. D. 1650.] 

A diamictonic rock, composed of quartz, ]m< 
pregnated" with slate*. 



■ t 
NOME XVn, QUARTZ, WITH EELSPAR- 

[Gu^Ri€iT£, from Otto von Guerick, A, D. 
1660.] 

Saussure has described a rock of this natureii 
the particles being so combined, that it could 
QOt be said to belong to either substance. 

• Sau88. $ 1955. 



NOM£« XViU. XI«;..XZr $\ 



NO>f £ XVIIL KERAUTE, WITH CHLORJTE. 

[KuKKSLiTE, from Kunkel, A. D. 1660.] 

This combination often forms the green kera- 
lite, one of the most pleasing appearances of 
that substance. 



NOME XIX. SCHISTOSE KERAUTE AND 

SLATE. 

[BoYLiTE, from Boyle, A. D. 1660.] 

The colour is grey, of a greater or less ten- 
dency to blue. 



NOME XX. SCHISTOSE KERAUTE AND 

UME-STONE. 

[Becch£kit£5 from Beccher, the great founder 
of modern chemistry, whose Pkysica Suhterranea 
appeared at Frankfort, 1669-] 

This seems chiefly to happen where the pri- 
mitive lime-stone joins the schistose keralite. 



52 DOMATN Ytn. DIAMICTONIC. 



NOME XXI. STEATITE, WITH ARGIL. 

; [Stahlite, from Stahl, 1700.] 

Dr. Babington informs us, that this substance 
is harder, and less unctnous, than common 
steatite, and has an earthy smell when breathed 
on. That of Cornwall is of a dark olive-green 
colour, and slaty texture*. 



NOME XXII. OLUTE, WITH SILEX. 

[PoTTALiTE, from Pottf of Berlin, who first 
analysed stones and earths, 1730.] 

This kind is described by Mr. Kirwanf. The 
quartz is in many parts visible in the veins, and 
the lustre approaches that of graphite* 

• Cat. St. Aubyn, p. 118. 
t i. 376. 



Wi>MMt XXIIl. niT. XXV. $$ 



NOME XXm. SERPENTINE, WITH SIDE- 

MTE. 

[Blacolite, from Blacky 176Q.] 

This compound is usually of a blackish co- 
lour, and the fracture rather foliated^ or striated: 
That of Portsoy is of a greenish black*. 



NOME XXIV. SERPENTINE, WITH BA- 

SALTIN. 

[Bergmanite^ from Bergman, 1780.] 

This substance is blacky and the fracture 
spJhiterj. If might perhaps be classed aioong 
the Sideromagnesian Hocks. 



NOME XXV. UM&STONE, WH'H ABGIL. 

* 

[Klaprothite, from Klaproih^ 1790.] 

This combination sometime!^ ocours In ttiaiv 
Ues ; for example, in that of Campan In ' the 

* Bab. at suptat 



^4 DCmAm Ttil* I>IAMICT0MC. 

Pyrenees, which from its remarkable structure 
however may partially be classed among the 
Aoomalous Rocks. Its decomposition in the 
air, so visible in the piUars of the palace at Tri- 
anon, is owing to the mixture of argil, which 
imbibes moistdre* Karsten, in his description 
of Leske's Museum, mentions granular lime* 
stone, mixed with clay-slate, from Kunnersdorf, 
in Upper Lusatia. 

HTPONOME X. 

Mtut>7^ !of Campan^ &c. 

Micramnmc 1. Lime-stone, with argiL 



ifbMA XXVI. LtME-OTONE, WITH GYP- 
SUM. 

[Lavoisite, from Lavoisier^ 1790.] 

Tlilft\s6ibeK;itfne8 occurs Hi Montmartre, oetr 
Paris. It js .a small proportion of lime^ natu- 
rally interm'ixed, which renders the plaister of 
Puri^ «(> ivraoh supeirior to .^her manufactories 
0fthijtsiib6taiice. ^ : <■ . 



HOMB SJCVJl. %iMM*BTOm, VITB 8ILBX. 55 

HYl'ONOMB I. 

Massire. 

BTPOVOMB II, 

Schistose. 



NOME XXVII. UME-STOlWE, WITH SILEX. 
{Bebtholite, firom BerthoUet, 1800.] 



Concerning the calcareous stones Mr. 
observes, that ^^ when mixed with siliceous par- 
ticles in considerable proportion, they effervesce 
with acids but slightly and slowly, and their 
fracture tends to the conchoidal, but often also 
to the earthy; of this we have a remarkable 
instance in Leske, s. 229. Its lustre, 0. Hard- 
ness, scarcely 9- Fragments, 3; which indi- 
cates the siliceous ingredient. Its sp. gr. only 
2,254 ; which shows it to be of the nature of 
sand-stone. Heated to 141^, it did not form a 
lime, nor did it melt. When the lime-stone is 
of the granular kind it has more lustre, and is 
much heavier, see Leske, s. 1098. But when 
the particles of silex are in a smaller proportion, 
or not purely siliceous^ the lime*stone presents 



\^ 



56 DOVAIK VIIX. iMAHlCTOIflt. 

a different appearance: thus the ]ime-stone» 
Leske^ s. 17699 seems as !f passing into horn- 
stone, and is of a yellowish grey colour. Lus- 
tre, 0. Transparency, I. Fracture, fine, splin- 
tery. Fragments, I. Hardness, 9- Sp. gr. 
2,640. It effervesces briskly with acids, but 
melts into a greenish grey compact enamel. 

^^ Effervescence with acids is not therefore a 
sufl&cieht pro9f that a stone will bum to lime : 
thus the dark bluish-grey stone, Leske 0. 1229; 
whose lustre is 0; transparency, 0; fracture, 
uneven and splintery; fragments, 2; sp. gr. 
2,740; hardness, 9; and which contains the 
impressions of various shells, and effervesces very 
briskly with acids, yet melts into a black com- 
pact glass. It has an earthy smell when breathed 
on. ^ 



NOME XXVni. GYPSUM, WITH MARL. * 

[Vauqu£Lit£> from VauqueUk^ 1800.] 

Gypsum often forms veins in hardened clay 
or marl, and is sometimes penetrated with the 
latter substance. Instances may be found at 
the Old Passage, near Bristol. 

* Kirwan, i. S73. 



DOHAIK nil. DUmCTOKIC , Si 

NOME XXIX. GYPSUM, WITH SILEX. 

[Davite, from Davy, 1810.] 

s the noted marble of tUviAtat 
line 

brn 

it yields a slight but 
easily perceivable phosphoric light. Its specific 
weight amounts to about 200 French pounds for 
each cubic foot. It is quarried at Vulpino, 15 
leagues from Milan, and is employed with suc- 
cess in that city in making tables, columns, 
Tases, or other works of that kind. Before the 
analysis it was regarded as a marble. 

HTPONOHB I. 

Uniform. 

HVPONOHB II. 

Veined. 

* Bratd, ii. 474. FUrin. iU. 99S. 



DOMAIN IX. 
ANOMALOUS. 



Amidst the infinite variety of nature 
there are many rocks which, though some- 
times composed of not unusual modes, are 
of so singular a structure, that they deserve 
to be ranked in a separate Domain ; more 
especially as the greater part are of distin- 
guished dignity and beauty. Others are 
entitled to this distinction from their gem- 



DOMAIM UL AKOMAI^Ot. 



mose natnre, being inlaid, so to speak, with 
precious substances; such as opaline fel^ 
spar, lazulite, chrysolite, and topaz. 

Those rocks may also be r^arded as 

-anomalous whidi are of very rare occur- 

were, another class 

isual laws a^d onkr 



Sveien -and Iia|]iand. The few rocks in 
ivhich barytes is incorporated may also be 
iuiQexed to this Domain, with !Ktuminous 
jmmI Sulphuric Rocks, which jere fer from 
common. 

'. The mifierail kingdom, as already men- 
tioned, is here Kgainded as divided into only 
^rtfe provinces, Petralogy, Lit^Iogy, and 
Metallogy: the class of Salts and Com- comttL 
Jbustiblcs being divided between the two 
Ibmier ^rovirtces. tn fact) the term nMzk 
-salt itadicates the protince of the onfy m^ 
fMhioh can properly and strictliy^ 4)e regarded 
'ss u mineral ; tlie others being found Jb 



00 IIOMAIH IS. AVOIULOeS. 

ivaters^ or deposited by them^ or appearing 
as mere efflorescences^ or at the most ia a 
gemmose form. And as the important and 
interesting study of Crystallography, or 
-Chrystallogy^ originated from the obseryar 
rtion of the salts, they may be considered a$ 
belonging to that department of Lithology^ 

But the Combustibles st^ind in a diff^rr 
cmi. .ent predicament, for coal is, in many coun- 
tries, a very common and abundant sub- 
'Stance; is found in vast beds, like manj 
rother rocks ; and may be said to constitule 
entire hills, as that of St. Gilles, near Liege* 
In this new point of view, therefore, coal 
has been ranked among the rocks; and 
that division also includes the bituminous 
. substances, which ouse from them, or may 
be found in their recesses; while amber 
and melUlite remain almost alone for the 
minute investigations of the gepimologist. 

In passing to the sulphuric substances it 

must be observed, that, a most common 

pyrites, and general appearance of sulphur, in py* 

rites, is so interwoven with most of the 

rocks, that it forms an important feature 



DOUAlU 12. AMOtfALOVf. 6l 

in petralogy. From the Alpine granites to 
the lowest beds of coal^ infinite are the 
rocks which contain pyrites. Henkel has 
written a large and learned work on py^ 
rites ; and a complete investigation of them 
by the gigantic powers of modem che- 
mistry, might perhaps decide the question ^ 
so long agitated, whether the rocky shell 
of this planet have been consolidated and 
expanded by internal heat, or merely de* 
posited by water. To conceive however 
that the matter of this globe is wholly inert^ 
seems to be contrary to all the other laws 
of nature, which abounds vrith various and 
prodigious kinds of motion and animation ; 
and appears to be positivdy contradicted 
by the vast force and extent of earth- 
quakes, not to mention inferior pheno* 
mena. 

However this be, pyrites form an im- 
portant consideration in the knowledge of 
rocks. Even native sulphur may be said to 
constitute rocks at Solfaterra, and in Gua- 
daloupe, and at St. Vincent's, not to men- 



Q^ DOMAIN IX. ANOMALOUS. 

tion other volcanic territories. It also ap- 
pijars disseminated in some lime-stones, as 
in Swisserland and Sicily. The fine ctys^ 
tals from ConiUa, in Spain, are intermixed 
with calcareous spar, on a rock of bluish 
indurated clay ; and they contribute to thd 
* elegant study of the Gemmologist. The 

Metallogist has also frequent occasions to 
describe the sulphurets, or combinations^ 
with sulphur, formed by many metals. If 
any objection should arise to thi& arrange* 
ment, the Salts and Combustibles may be 
thrown into appendixes ; for the theme is 
too confined to form a distinct province in 
the itiineral kingdom. 

Prom these considerations the rocks of 
common salt^ with the bituminous, su^ 
phuric, and metallic, as thoi^ of iron, are 
ranked among the Anomalous ; while, those 
intermixed with pyrites are so trivial, that 
it is scarcely necessary to distinguish, tbemi 
even from the commcm Modes of the SkAh 
stantial Domains. 
. The first di\ifiion of Anomalous Rodca^ 



VOMX I. MIAGITt. 63 

as already mentioned, win chiefly consist 
of those that depart in their structure from 
the common laws of nature. 



NOME I. MIAGITE. 

This rock is generaUy considered as the most 
beautiful which has yet been discovered. In 
the mode it is a graniteU being a mixture of 
white felspar and black siderite ^ whence it has 
by some been called Corsican granite, or Corsi* 
can granitel ; and by others, from some resem^ 
blaace to the eye, ocular granite, or, as it more 
properly may be expressed from, the Gneek, 
cphthalmite. The structure however forftis a Uescnptioii. 
complete anomaly from that of granitel, as it 
consists of concentric but irregi^ar circles of 
white felspar and black siderite, disposed in 
broad or narrow lines, which are defined with 
the greatest precision*.. Sometimes one oval 
spot of the siderite is surrounded by an irregular 
oval of the felspar ; the base or ground of the 
whole being siderite and felspar irregulariy m* 
termixed. In other spots the centre of siderite 
is surrounded by a light grey mixture of the two 

' * There is no ndUtioii from the centre, is in the phte of 
Patrin : that of Besson is preferable. 



'64 DOMAIN IX. ANOHAXOU8. 

substances^ bounded by a single black line about 
half a line in breadth^ : ficJlowed by a broader 
circle of the felspar. In others the centre is 
dark grey, bounded by two narrow black lines, 
followed by a broad circle of lighter grey, suc- 
ceeded by a black band, about a line and a half 
in breadth, followed by the white of a quarter of 
an inch. But the most beautiful glandules, as 
well as the largest, are those whidh present a 
narrow black line, like a hair^ on one or both 
sidies of the black band. 
Site. This most singular and beautiful of all the 

rocks was, it is believed, first described by Bes* 
son, a venerable mineralogist, formerly Inspectbr 
General of the mines in France*. But Patrin 
informs us that it was discovered by Barral, a 
French engineer employed in Corsica ; being 
merely a large solitary block, found, by Besson s 
account, beneath Olmetto : but as there* are 
many places of that name in Corsica, the indi^ 
' cation is not distinct^. So imperfect was theh 
the knowledge of rocks, that Besson supposes 
the siderite to be steatite. -The felspar ibay 
however be mingled with quartz, as he and F^ 

. * Journal de Physique, 1789* 
t Saussure says, § 1479, ^^^^ ^^^ ocular granitel of Corsica was 
' disoovered by Siooville; and Saussure intended to have describediit, 
when he was prevented by Besson. 



nolIB I* MIAOITS. 65 

trin suppose. In the base there are also specks 
of pyrites, and perhaps a little yellow mica, as 
Patrin mentions. 

The block found in Corsica was by the French ^^^ 
mineralogists considered as unique, till the au- 
thor pointed out to them a clear passage in the 
travels of Saussure ; whence it appears that this 
rock was found on the glacier of Miage, long 
before its discovery in Corsica^. This glacier 
adjoins to Mount Broglia, on the south-east side 
of Mont Blanc, where it regards Italy. The 
whole passage deserves to be transcribed : 

*' After a walk of an hour and a half from the 
huts, I gained the glacier of Miage. This part 
of the glacier was then entirely free from snow^ 
and the ice was of an extraordinary purity ; the 
sun from behind projected my shadow, which 
penetrating to a great depth in that firm and 
transparent medium, produced the most extra« 
ordinary effect in the world. No crevice op- 
posed our progress ; while rivulets of clear living 
water ran in transparent channels, which they 
liad formed for themselves. 

^< This singular soil is covered with the most 

* Saoasore^s first Journey was published in 1786 ^ and this excur* 
skm seems to have been performed in 17S1. 

VOL. II. F 



^5 0OltAIS IX. AMOUkSJOVS. 

beautiful stones which I have ever behdd* Tke 
largest blocks, and there were some from dO to 
40 feet in diameter, were of a granitello, com- 
posed of white felspar and black schoil^ in plates. 
These two kinds of stone were mingled in all the 
proportions, and under all the forms imaginafale. 
Upon one, were large parallel fillets of tke 
purest white and black; on another, nodules of 
the most beautiful black, surrounded with con- 
centric Ycins alternately white and black. Others 
presented yeins in zigzag, between parallel Teins. 
Those which astonished me the most by their 
structure, were the stones which displayed pa- 
rallel layers, terminated by Other layers which 
cut them at right- angles, without any appearance 
of rent or subsequent junction, the block appear* 
ing completely uniformf. I greatly regretted 
that these beautiful masses were not within the 
reach of a manufactory, where they might be 
sawn and cut, to make vases, and above all 
tables, which would be of the most perfect 
beauty. For there is no marble which can ap» 
proach to these stones in regard to the nz^ of 
the veins, their extrane precision, and the bright* 



* The Ungoa^ of that time for hornblende or si 
f So quartz sometimes appears in day siate^-i-P. 



tfOMl I. MIA61TB. 67 

ii€98 of the black and while which compose 
them. Besides, these stones are harder than 
marble, and capable of the most lively polish. 

<^ The bases of the momitainsj which enclose" 
the gletcier of the Miage on the right and on the 
left, are all composed of rocks of this kind. As 
to Uieir extierior form, they appear almost every 
where as ajsembUges of pyramidal large plates 
very pointed ; five, six, or even a greater nnm- 
ber of these plates often leaning against each, 
other, though separated by fissures which de* 
scend to the bottom. The pyramids ^re them* 
selves divided by slits parallel to their sides, and 
which often meet in such a manner as to indi'- 
cate partial pyramids, similar to those of which 
they form a part. In some, there are seen slits 
perpendicular to the planes of the plates; and 
which cut in the same direction many consecu- 
tive plates. Th£ blocks, which are detached 
from the faces <^ these pyramids, leave empty 
spaces of a square form, particularly in the 
upper part, because the lower must necessarily 
slip, before the upper blocks can disengage 
themselves. 

** I asked myself, in observing all the pheno- 
mena, if the whole of this organisation did not 
prove a crystallisation, which had produced, at 

F 2 



gg DOMAIN IX. AMOHALOUS. 

the bottom of the waters, horizontal beds, after- 
wards raised up by a great revolution, and lastly 
divided by the effects of time. Eleven years of 
observation and meditation have served to con- 
firm me in that opinion.^'^ 

It is evident that one of the singular rocks 
above described, that with concentric zones of 
black and white, is the same which was found ih 
Corsica. It might be styled Oculite, or 0/>A- 
thalmite; but as agates, and other substances, 
sometimes assume that form, it was thought 
advisable, as a new name is indispensable for 
so singular a structure, to term it Miagite, 
from the place where it was discovered by Saus- 
sure. 

This excellent observer afterwards discovered 
similar rocks on the glacier of Lauteraar. 
Sltow. " ^^' being able to survey these ridges, I ob« 
served at least the wrecks with which the gla- 
cier is covered, and which come from these 
ridges, or their vicinity. Some of these frag- 
ments are of common granite, others of veined 

* Sauss. § 892^ 893. In $ 899* mentioning granular felspar re- 
sembling granular quartz, but melting under the blow-pipe, Saussure 
adds, that in the beautiful granitel of Miage the felspar is also con- 
fusedly crystallised, but its white and sparry plates are evident; 
whereas here it is disguised in the form of a sandstone. 



MOMtm f« MIAGITE. GQ 

granite ; some of gneiss, others of granitel, or of 
a rock composed of felspar and hornblende* 
We see the elements of this granitel sometimes 
mingled, scxnetimes separated in the form of 
layers, some qnite white, others quite black; 
these layers are here straight, there in zigzag, 
or interrupted by knots or kernels ; these acci- 
dents are generally the same, but less marked, 
less beautiful, than at the foot of Mont Blanc, 
§ 892. The most remarkable rocks of this kind, 
that I saw on the glacier of Lauteraar, are those 
which enclose other fragments, whose layers cut 
at right*angles those of the stone or block which 
enclose them. I also observed roches de come, 
or schistose hornblendes, of different qualities ; 
and the fragments of that rock were covered 
over with a yellow ochre, occasioned by the 
oxydation of the iron enclosed in it. Many of 
these large blocks were sprinkled with rock 
crystals, formed in the crevices which had occa- 
sioned the separation of the rock. These crys- 
tals were frequently accompanied with a velvety 
green earth, or with chlorite."* 
. In ^ 1572 he had given an account of the 
pebbles of the river Isere, which runs by Greno* 

* Sautt. { 16^. 



70 DOKAtW IX* AtiamAvovs* 

ble. Among them are the variolites of Drac ; 
and another varioHte, of laminar siderite, of a 
dvH black inclining to green; spangled with 
crystals of felspar, sometimes rfaomboidaU some* 
times citxralary with green dots of homUende 
towards the centre. Sanssare obserres^ that it 
somewhat approaches to the ocular granitel of 
Corsica, the crystallisation being only more 
confused. 

The following detached observations of this 
skilAil Petralogist, mdy throw additional light on 
this subject. He supposes, § 1599 that layers 
in zigzag probably arise from ciystallisation, as 
they do in alabasters : and § S227> he mentions 
layers in zigzag, in a granular lime-stone, mixed 
with mica, included 'betw^n other veins which 
' are pafaHel. Sudi layers, he adds, are not only 

found in ciystallised rock> but in slate, which 
presents no appearance of crystallisation. 

The ocular appearance is also found in other 
rocks, and Faujas has formed, a series of this 
kind* Saussure indicates, § 161, mica slates 
often containing nodules of quartz, which, when 
cut across, appear like eyes« Sometimes they 
are as small as grains of millet y and others are 
two inches in diameter. 

An ocular serpentine is also found in Corsica. 



MOMB I. MIAGin* 71 

See Bariml) p. 31, who says tliat a serpentine in 
globules, the size of a nut, some ribboned, some 
with concentric zones, forms mountains near 
FittOKMrbo. 

Mr. Strange published at Milan, in 177S, an 
account of: some columnar hills in the north of 
Italy* They seem to be not of granite, as he 
sapposes^ but basalton.* That of plate iv. fig, 6. , 
resembles Miagite. 

A late French writer, who does not seem to 
have examined the accounts of former inquirers 
(an accident which often happens to the lively 
writers of that nation), informs us, that '^ only 
one mass of this magnificent stone was found on 
the shore of Taravo, half a league from the sea, 
in the gulf of Valinco, in Corsica. It might 
weigh, when first discovered^ about 80 pounds ; 
but it was soon beat to pieces, and dispersed 
into the principal cabinets, so that theve now 
only exist of it small pieces, either polished or 
unpolished. A beautiful vase, 18 inches in 
height, is in the celebrated cabinet of M. De^ 
dthe ; and his Majesty, the Emperor and King, 
has a snuffobox of this beautiful stone. The 

• 

beauty of this rock, and the singular disposition 
of its colours, engaged every possible research to 
discover the mountain, whence the mass might 
have rolled ; but to this day they haie been un- 



79 DOUklV XX. ANOMALOUS. 

8ucce8sfi)il, 80 that the smallest pieces of thii 
stone are extremely dear."* 

This is truly surprising; and affords a further 
proof, if necessary, that the ingenious writers of 
France, with their clear heads and nniyersal 
talents, never think it a duty, though it be in* 
dispensable, to read preceding accounts^ that 
they may not repeat what is already well known ; 
nor, above all, want the necessary knowledge of 
their subject. For to write on any science^ 
without a complete knowledge of what has be^i 
already done, can in few instances contribute to 
its real advancement, which ought to be the 
chief end of every publication. The glacier of 
Miage, where so many beautiful varieties of this 
rock occur, cannot exceed two French leagues^ 
or six British miles, from the little town of Cor- 
mayeur, on the river Doire; a distance surely 
not invincible for sledges or other conveyances : 
and any man of common enterprise might soon 
disperse these beautiful stones all over Europe. 
The fact is, that the passage of Saussure had 
totally escaped notice ; and at present is only 
known to M . Sage, and a few other mineralo- 
gists, to whom it was indicated by the author. 

It must not be forgotten that^ in whatever 

^ * Braid> ii. S87- 



NOteB I. MIAOITB. ^$ 

direction the Miagite be cut> the nodules appear 
the same^ so that the globular form is complete. 
It is also observable that Laet^ a writer of the se- 
venteenth century^ has quoted a preceding au- 
thor, Imperati, to this effect : *^ I must not pass 
in silence a very remarkable kind of marble, and 
hitherto undescribed, if I bxA not deceived. It 
is brought from an island in the gulf of Genoa, 
called Monte Cristo 5 and its colour is a greenish 
white, but it is all marked with black equidis- 
tant lines. It is extremely hard, and very rare, 
so that we have only small fragments/'^ He 
then gives a print, which corresponds with one 
of the rocks described by Saussure. The Tiege* 
rerz of the Germans, which ought rather to be 
styled Leoparderzp being spotted, not striped, 
with black, ma^ also belong to this stone. If 
Saussure had been aware of these instances, he 
would perhaps have argued that in his grand 
debacle these stones had been rolled from the 
pre-eminent height of Mont Blanc to the islands 
of Corsica and Monte Cristo, before the forma- 
tion of the Mediterranean Sea. 

« Laet De Gemmis et Lapidibus, l647> Sto. p. 167. Imperati 
infonna us that, in hit time, all the stones used in architecture were 
called marbles s while those employed in personal decoration were 
styled genu. 



• 



74 DOMAIN ZX« AKOUALOVS, 



HTPONOME I. 

Ocular Miagite. 

Micronome 1. With straight lines. 

Micronome 2. With zigzag. 

Micronome 3. Dendritic. This is the beauti* 
FmI 'Stone Only found in the ruins of Rome, the Nero 
e Bianco, falsely called a granite. 



NOME II. NIOUTE. 

Faujas, in his late interesting work of geology, 
is the first who has described this singular rock, 
of which he has also published a coloured plate* 
Description. His general description is that the base or ground 
consists of compact felspar, or felsite, of a brown 
colour, marbled with redj containing large 
spherical kernels of a flesh-coloured felspar, dis« 
posed in unequal rays or petals compressed upon 
each other, and diverging from the centre to the 
circumference. ..M« Rampasse, who brought 

* Parisj 1809> 8vo. ii. 945. 



KOIH II. HIOLITB* 75 

nany specimens from Corsica, said he fonnd 
them at the foot of Monte Pertusato^ one of the 
dependencies of the chain of Niolo ; which, with 
its valley, has been long since celebrated by 
Dolomieu for the variety and beauty of its 
fithology, 

<^ The ground of this beautiful rock is of a deep 
brown, with numerous little spots of a jrellowish 
red, which have a pretty effect. They pene^ 
trate the whole thickness of this stone, and pro* 
bably arise from the oxydation of the iron, which 
abounds in the base of the rock ; but this state 
of oxydation has little injured its hardness, and 
does not prevent the stone from receiving a tole* 
rable polish. 

*^ Amidst this ground spherical bodies ap- 
pear ; some being an inch, an inch and a half, 
and even three inches in diameter. Many are per* 
fectly round, others oblong, and they are placed 
near each other, having the aspect of balls or 
geods, solid in the interior, and strictly em* 
braced bv the base, as if formed when the latter 
Was soft. 

*< But in this sort of explication we might fall 
into the same error as DaubentQu, when he 
wished to apply this system of formation to the 
ocular granitel of Corsica i which^ like this rock, 
is only the result of a particular mode of ciystal* 



^Q DOMAIN IX. ANOMALOUS. 

ligation, of which numerous examples occur in 
the rocks and stones. 

" To distinguish perfectly the interior organi* 
sation of these bails> and discover the manner in 
ivbich they have been formed, it is necessary to 
cut, with iron wire and emery, some plates off 
the rock^ so as to reach if possible the centre of 
the balls. They must then be slightly, but not 
highly* polished; the former being preferable 
for this kind of rock, as it renders its lineaments 
more clear and distinct. It is then evidently 
seen that the interior of these balls is solid, com- 
posed of compact felspar or felsite, of a if hite 
tinged with rose-colour, disposed in rays, or 
rather petals* ; being flat imperfect crystals, ter« 
minating in sharp points, and diverging from the 
centre to the circumference. An envelope, 
about a line in thickness, of a lighter felsite, 
surrounds the globules ; and, when divided by 
the saw, this envelope presents a circular line, 
which encloses and circumscribes each disk, 
serving as a kind of frame. The flowers thus 
displayed then produce a beautiful effect ; and 
if it were possible to obtain large pieces of this 
rock, to saw in the form of a table, or turn in 



* PetaJum means a thin plate; and was originally transferred 
Ifora metak to the leaves of flowers in botany. 



NOMX II. MIOLITB. 77 

that of a vase, it would become one of the most 
beautiful materials of the arts. 

" There is another variety of this . rock, with 
little globules very near each other, but offering 
the same system of formation. This, according 
to M. Rampasse, appears in different parts of the 
chain of Niolo, in Corsica, being far more com- 
mon than the former ; but very curious, because 
in the fractures may be easily discerned the 
mode of formation of the globules, which are the 
result of a particular system of crystallisation. 
The oxydation of the iron having diminished the 
force of the cohesion of this rock, it is difficult 
-to obtain large pieces. The same cause has 
occasioned shades of different colours ; while the 
size of the globules does not exceed four or five 
lines in diameter. Their formation approxi- 
mates to that of the variolites of Durance ; but 
their crystallisation is more decidedly enounced 
than that of the latter." 

From this last description it seems doubtful 
whether the petals appear in ihe latter kind. 
As the flowers of the former bear no small re- Ntme.. 
semblance to the marigold, caltha, it was ima- 
gined that Calthite might be a proper appella- 
tion : but if in the smaller kind no petals ap- 
pefu*, the name of Niolite may be preferable; 



IJ'g DOMAIN IX. AVOKALOUS. 

especially as Niolo is celebrated for variouB 
beautiful stones*. 



NOME nr. CORSILITE. 

This beautiful rock being also from Corsica, 
it was thought proper to propose a geographical 
name ; and an island so eminent in the history 
of the rocks, well deserves this distinction. 
Deseriptkm. The rock now in question is a most beautiful 
mixture of greyish white, with the most delicate 
emerald green, which presents at the same time a 
satiny appearance. According to Werner, it is 
a mixture of felsite, or compact felspar, with 
actinote. Among the Italian artists, it has been 
long known by the name of Verde di Corsica s 
and Ferber, in his intelligent travels through 
Italy, 1772, informs us that '' the Verde di Cor- 
sica is no marble, but a hard rock, striking fire 
with steel, of a white substance, with blackish or 
violet spots, and large grass-green sherl crystals, 
of a sweet colour. Large tables of this fine 



* Even in the lai]ge maps of Bacler Dalbe« Corsica most be im- 
perfeetly represei^ted, for Niolo^ and other names often mentioned^ 
are not to be ibuiKL " ' 



MOMB iU. C0ft81LlT£« 79 

9(one are to be seen in the Capella di S. LorenaOj 
at Florence.*' 
Saussore, who jdiscovered pebbles of this rock Samtu^'i 

' ^ remarks. 

among those of the lake of Geneva (which in* 
elude many curious substances brought bj the 
Rhone^ and its confluent ^treamsj often from 
inaccessible parts of the Alps), and afterwards 
found it in its native places, describes it as com* 
posed of jad and a new substance which he calls 
smaragdit€j from smaragdus, the Latin name of 
the emerald. He found it in the mountain of 
Musinet, near Turin, which also presents the cu- 
rious semiopals, called hydropbanes: and which 
chiefly consists of serpentine, and other magne- ' 
sian rocks. In another spot also, among mag* 
nesian rocks, he found the same substance -, but 
the smaragdite was of a grey colour*. In Cor<« site^ 
sica it is found iu detached masses^ which en- 
cumber the bed of the rivulet of the village of 
Stazzona, and which came from the mountain of 
Santo Piatro di Rostino, not far from Orezza. 
Hence it has also been called Verde antico di 
Orezza. It is also found in large detached 
masses at Voltri, near Genoa ; and a similar rock 
b found at Estendorf, in Stiria. The same com* 



* Sautt. $ 1313, 136s. See hb acoount of tmtngdite, § 131^. 
He obiervct, that oriental jad is veiy fittiUe. 



go BOMAIM IX. AVOIIALOVS. 

I 

position is found at Serviere> above Brian9on ; 
but the diallage, or smaragdite, is black, yellow, 
bronze, grey, or silver-grey*. In other in- 
stances, the diallage has a metallic splendour; 
and the author has a specimen, which he re- 
ceived from Faujas, of a rock composed of ser« 
pentine and felspar, containing metallic diallage ; 
and which was discovered by the Marquis de 
Cubieres, in the ruins of Pompeia; so that 
scarcely a beautiful rock can be said to have 
escaped the researches of the ancients : and the 
ruins of Rome are found to present about two 
hundred and fifty kinds, while those of London 
would only afford white marble. 

The most complete account of the beautiful 
rock here called Corsilite, may be found in Pa- 
irings ingenious system of mineralogy. The 
Smngdite. smaragdite, he observes, was formerly called 
. mother qf emerald; and sometimes appears to 
have passed even for emerald itself. This sub- 
stance is a singular combination of many con- 
stituents, as may be judged by the following 
analysis, by Vauquelin, of the green and grey 
smaragdite ; a name which, might be retained as 
a compliment to its great observer, and as the 
green is its most usual and beautiful colour. 

• Braid, ii. 309. 



WOMB lit. OOtSf&ITfe. 




Silex . .... SO 


. 


Argil , 


, 21 




Magnesia . w • , 


6 




Lime . , . • . . 


, IS 





Osfydbf Iron . , 


5 


50 


Okyd of copper 


1 


10 


Oxyd of chrome 

■ • 


. 7 


50 



81 



104 10 • 

The increase of weight arises from the. oxygeoj 
which has been absorbed by the metallic oxyds 
during the operft^ion. 

In his recent piiblication, Haiiy places the dmm^ 
green diallage as a variety of the strahlstein 
of the Germans^ while be regards the metaU 
loid diallage, or that with metallic splendour, 
as the schiUer spar and Labrador hornblende 
of many mineralogists, the schillerstein of Wer<* 
ner, and the bronzit of Karsten. He has also 
found a palpable transition from the fairest green 
to the grey metallic splendour*.. As this in- 
teresting substance rivals the.gems in beauty, its 
description will not be found prolix. 

The base of this rock has, by Saussure, been 
called a jad ; by Werner, a compact felspar ; by j^ 
Haiiy, from its toughness,' a tenacious felspar. 
The substance called jad, has been recently di- 

* Tableau coznpantif> p. 46. 
VOL. II. O 



9§ DOMAIV IS. AN01IAI^V». 

Tided into two mod^^ axinite and kmMnite; the 
former, as Haiiy has quite a different axinite (a 

Pdekme. Crystal from Oisans), might be called pelekine, 
from the Greek term for a, battle-^e* ; for it 
implies the green substaace wcoiigbt in that 
form, from New Zealand, hoA fram Scwtth Ame- 
rica, where, as described by CoadasHoej it forms 
the real stone of the Amazons : a tribe idly so 
called on the Maranon, or river of Amazons, 
because the women upon one occasion defended 
themselves, while their husbands were absent in 
the chase. This substance has been anidysed 
by Hoefher, who pretends to have "found dS of 
magnesia ; but his authority is absohrtefy null s 
and this interesting substance rembins a problem. 

Lemanite. The lemanite, which bears the same aspect, has 
been analysed by the younger Saussure, who 
discovered no magnesia, but a considerable pro* 
portion of argilf: and it is possible that even 
the green kind, for that colour often indicates 
the presence of magnesia, may, like the Iconite 
of the Chinese, analysed by Klaprotfa, contain 
no magnesia, but merely an unctnotts arg^K 
The lemanite receives its name from the lake 
Leman, commonly called that of Geneva. 

* TisXsKvg, bipefmit. 

t Silex U, Lime 4, Aiigll dO« Ozyd of iioa 12,5, Soda 6,=96, 5. 



account* 



MOMB HI. COfiSILlTB, 83 

I 

The account of this inteFesting rock 3bali be 
closed by an extract from Patrin. 

'< The beautiful rock which the Italians call Patrnfs 
V^de di Corsica, is a mixture of the two pre- 
ceding substances, the smaragdite and the le- 
manite jftd ^ in which the white and the sptiny 
appearance of the green, have the most beauti*- 
fttl efiect« This rock is found in the primitive 
steatiUc mountains of Corsiqa. Some magnifi*' 
cent tables of it are seen in the chapel of Medi- 
CIS 5 and lately the Museum of Arts, at Paris, 
|ias several : which are of the greater beauty^ as 
they serve for a base to some mosaiq picture^ 
from fXorence, which are master-piecesof an art 
unknown in France. With the natural colours 
of jasper and agate, the art of the lapidary hfts 
been able to represent objects of nature with a 
correctness which seems to vie with painting 
itself. 

^^ Three of these pictures (as they may justly 
1^ 6tyJied) are on a base of xme single vlab of 
Ffirde 4i Corsica, wl^iph displays a considerable 
border ^U round the n^9saic s the latter represent- 
ing tables^ or trays, loaded with different vases. 

** Two of the pictunss seem to be at least 3 
feet long, and 18 or 20 inches high. The Verd^ 
di Corsica, which constitutes their base, has not 
the least defect ; the jad predominates, its colour 

g2 



84 DOlffAIM IX. ANOMALOUS. 

being sometimes of a greyish white, sometimes 
inclined to lilac ; the smaragdite is disposed in 
small masses, which never exceed one or two 
inches in diameter, and is of a beautiful velvety 
^rass green. 

*' The base of the third picture is of a most 
extraordinary beauty; it is* at least 4 feet long, 
and 28 or 30 inches in height. It is almost 
Entirely composed of pure smaragdite, of a dark 
grfeen, and yet of the most beautiful semi-trans- 
parency, which has a more imposing effect than 
if perfectly transparent, by the varieties which 
its niixttire forms with the jad. The latter is in 
small quantity, but spread in the form of little 
undulating leaves, as thin as paper, and as white 
as milk. As the stone has, with much inge- 
nuity, been cut obliquely to the planes of these 
leaves, their extremities are seen on the surface, 
and in proportion to their depth in the smarag- 
dite, they assume, by imperceptible degrees, the 
beautiful green colour; which, added to their 
undulating and festooned form, and their dispo* 
sition in little masses near each other, n^akes 
them resemble in a singular manner the beautiful 
foliage of trees, and, in other parts, the waves of 
the sea gently agitated.*^ 

* Patrm^ Min. i. l63« 



KOm IT. lUHlTB. ^5 



HTPONOMB I. 

White and green. 

HTPONOMB II. 

With violet spots on the base. 



NOME IV. RUNTTE. 

This rock is of rare occurrence^ and has often 
been fonnd to serve as a gangart to the topaz. 
It is composed of felspar in large plates^ inlaid Dttcnptioii. 
with crystals of grey quartz ; which, when cut 
transversely, offer angular figures, of which the 
greater part have the form of the Arabic nume* 
ral 7 ; while the others are more or less regular, 
presenting a rude appearance of Hebrew cha- 
racters*. The resemblance of Runic letters is Name, 
lar more exact, whence the rock is here called 
Ranite. 

The graphic granitel of Autun is one of the 
most celebrated : the fdspar being of a pale 
rose^coloar, while the cry stab of quarts are grey, 
small, and infinitely multiplied. Brard regards 



86 ^ DOUAIir tX. ANmfALOU». 

this as th& most beautiful of all. It is found 
Sites. near Autun, in the department of the Saone and 
the Loire, and particularly at Marropgne. There 
is also found, in the environs of Atitun, a white 
graphic granitel, with little crystals of grey 
quartz. Champeaux, an engineer of the mines 
of France, discovered the rose-coloured kind of 
Marmagne^ of which, small tables might be 
formed. 

That of Corsica is of a yet paler rose-colour 
than that of Autun, while the crystals of quartz 
are larger and more distMit from each <^er. 
There are also some specks of bronze^mica, 
which do not occur in that of Marmagne ; but 
h IB capable of an «qtial polish. 

That of Scotland is of little importance, as th^ 
crystals of quartz are distant, and not sufficiently 
apparent. It is found near Portsoy, 

That of Siberia appears in two distant site^ ; 
the Ufalian mountains to the north of EkatAin* 
burg, and in Daouria near the river Amur ; the 
felspar being of a yellowish, or reddish white, 
laitiitoar, and gKstening*. ft is charged with 
crystals of smoky quartz, which may be coin- 
pared to Runic letters t and is accomnanied with 



• Chaiayant, derived from the eye of the cat j it has scarcely a 
^mspoDding term in Engliib. ReAilMit f 



some specks of mica, and large neecUes of black 
schorl. 

The worthy and ingenious Patrin says^ that 
he himself discovered that of Daouria, in the 
mountain Odon Tchelon, which furnished him 
with many topazes, and prisms of beryl of an ex- 
traordinary size. He observes, that the quartz 
rather forms carcases of crystals, imperfectly 
hexagonal, the most usual form of that sub* 
stance : and he regards that of Scotland as of a 
different crystallisation, the felspar appearing to 
have been f3rmed in rhomboidal prisms, while 
the intervals have been filled with a quartzose 
fluid, bearing no evidence of crystallisation. 

« 

HVPONOMB I. 

With dbtmct crystals. 

HTFONOMB II. v 

With CQPiuoed* 



68 DOIfAIir. IX. Ay01CAI.01T8. 

• J ' I ' 

/ 

NOME V. LAZULTTE ROCK. 

pf this magnificent and interesting object, a 
better acpount cannot be given than in the 
words of Patrin. 

Ocsciiptioii. • <' The Lapis lazuli^ often simply called lapis, 
is a rock of a beautiful sapphire blue, generally 
mingled with veins and spots : it sometimes con- 
tains pyrites, which was formerly mistaken for 
grains of gold ; and spangles of mica, in greater 
or smaller quantity. This rock is hard: the 
blue parts are quartzose, and strike fire with the 
steel; the white veins are of felsite, sometimes 
mixed with calcareous spar or gypsum $ in some 
parts are to be perceived, in the tissue of the 
substance, brilliant plates like those of horn* 
blende. 

** The Lapis, which abounds with the blue 
substance, is wrought into various trinkets and 
other ornaments ; although granular, it is capa- 
ble of receiving a very fine polish. 

uitnumrioe. *^ A valuable colour for painting is prepared 
from the Lapis, known by the name of Ultra- 
marine ; because it is brought from the trading 
towns of the Levant. The blue colour is very 
vivid and intense ; and^ above all, possesses the 



NOm ▼• LAXVLITS ROCK. 89 

inestitnable property of being unalterable. It is 
to the ultramarine that we are indebted for those 
rich tints, so much admired in the skies and 
draperies of the first masters. 

** The Lapis is found in several countries, but Sit«. 
in very small quantities; that which furnishes 
the most is Great Bncharia ; it is from thence 
that it was brought to Russia, where it was so 
profusely used to ornament the marble palace, 
which Catherine the Second built at Petersburg, 
for Orlof, her favourite* There are in this pa^ 
lace some apartments entirely lined with lapis. 
It would be scarcely possible to imagine a deco- 
ration more simple, and at the same time more 
magnificent. 

<* I met with, at Ekaterinburg in Siberia, a ^ 

dealer in stones, who had been at Bucharia : I 
inquired of him concerning the nature of the 
mountains, whence the Lapis is brought^. He 
informed me that it was found in granite ; that 
it did not run in veins or streaks, but wai» disse- 
minated in the entire mass of the rock, in all 
sorts of proportions ; that here only a few slight 
bluish spots were perceivable upon a rock gene- 
rally grey ; there the spots were closer, and of a 
more lively tinge: in fine, small masses were 

* It is said to be found near Kalab aod.Budneah, in Bucharia.— -P. 



90 DOMAIir IX. A1IOJIALOT8. 

found of 8ti almost entire blue ; but that it was 
extremely rare to discover pieces as large as one's 
bead, in which the blue should generally predo* 
minate over the white and the grey. As those 
blocks, which I had seen, appeared to me rolled^ 
I asked if they had been found in the beds of 
rivers; and was informed they were taken from 
the quarry, and that they were rounded by their 
friction against each other in the carriage ; but 
that sometimes, however, they were found by 
chance in torrents, and these were of the most 
brilliant blue. 

<< Laxmann, an academician of Petersburg, 
who resided several years in Eastern Siberia, said 
he foundroUedblocksof lapisupon the shoreof the 
lake Baikal, in a kind of gulf, to the southward, 
called Koultouk ; but that he in vain sought for 
the mountain froiti which these blocks had been 
detached, and that he could get no information 
from the Buret Tartars, who inhabit this savage 
country. I have a specimen of this lapis, which 
b exactly similar to that of Bucharia. 

^^ Boetius de Boot has given a long account of 
the manner of preparing ultramarine. This 
operation consists chiefly in the repeated calci* 
nation of the lapid, and plunging it in vinegar : 
he adds, that the oftener these calcinations are 
repeated, the finer the colour. That of the first 



quality was sold, in his time^ at SO dollars an 
ounce, which is dearer than gold. 

^' Duiay, of the Academy of Sciences, has 
fdnnd the lapis when exposed to the sun, and 
afterwards brought into the dark, to give a phos- 
phoric light ; and that the purer and deeper the 
blue, the stronger the phosphorescence. The 
grey and white kinds have not this effect. 

^' In some mineralogical systems, lapis was 
classed with s^eolite; but a further knowledge of 
the nature of these two substances, has again 
separated them. 

*' The lapis has sometimes been confounded 
with the Armenian stone, which is totally dif- 
ferent, and is nothing more than a fine moun- 
tain blue, or oxyd of copper; and the colour 
which is extracted from it, though fine at first, 
' has not the durability of ultramarine. 

*^ The analysis of lapis lazuli yielded to 
Klaproth : 

« Silex 46 

Argil ..... 14 50 
Carbonate of lime S8 
Sulphate of lime • 6 50 
Oxyd of iron . . 3 
Water .... 2 



100. 



»> 



92 DOMAIN IX. ANOMALOUS. 

fiapphiret of The lozulite appears to have been the sapphire 
of Pliny, which was spotted with gold ; and an- 
cient engraved gems have been found of this 
substance. Wad mentions two Egyptian monu- 
ments of this stone ; being little statues, an inch 
or two in height. 
y«f • The lazulite of Werner, fotind at Varau in 
Austria, and in Salzia or Salzburg, is a different 
substance, recently arranged with the blue felsite 
of Krieglach in Stiria. But Haiiy regards it as 
distinct*. The lazulite here described, is the 
lazurstein of Werner. 

HYPONOMB I. 

With deep blue lazulite. 

HTFONOMB II. 

With whitish. 

* HaC^y Tableau, S25. 



NOME VI. OKAWITB WITH SAKAKB. 93 



NOME VI. GRANITE WITH SAPPARE. 

This rock has only been recently observed; 
The sappare is in small spangles> of a lively 
blue, being interspersed among the common in-« 
gredients of granite. 

Saossure informs us^ that he first rieoeived tbts 
substance from the Duke of Gordon, among 
other Scotish minerals; yvho informed him, at 
the same time» that the Scotish naiQe was sap- 
pare*. Werner (whose fondness for the worst 
of all nomenclatures, that derived Ax>m acci-' 
dental colours, has been ably ndiculed by Mr» 
Chenevix), has, forgetting all due respect to the 
great name of Saussure, most needlessly chaog^ 
this denomination for Kyanite^ or blue stone !• > 



NOME Vn. LABRADOR ROCK. 

The celebrated opaline felspar, originally, as^ 
is said by some, discovered by the Missionaries 
in the transparent lakes of that country, while 
others affirm that it is only found in the Island 
of St. Paul, to the sQuth of Labrador, has scarcely 

• § 1901. 



94 OQMAiN IX. AVOMALOUB. 

yet been observed in tbe parent rock, which \s 
only inferred to be a kind of granite. Another 
rock containing opaline felspar, but of fiaur infe* 
rior beauty, has been recently observed in Nor- 
way. The felspar is conjoined with a very hard 
reddish substance^ which has been inferred to b« 
quartz. 
*^Jwe«- In the Bee, a periodical papM, pubiished at 
Edinburgh in 1993^ by Dr» Andierson, thene is a 
curious account of precioas stones by Dr. Gatb* 
rie, physician to the corps of Noble Cadets at 
Petersborg, presenting some interesting parties* 
lacs concerning tboM fbnnd in Siberia. A cor* 
rei^ndmii of Dr. Anderson's has added a lett^ 
concerning the first appearance of the Labrador 
stone i whichi being little known, shall be sntv* 
joiaed. 

'' The coast of Labrador is k coM inhospitable 
country, bordering upon Hudson's Bay; and 
was granted by George IL to a religious sect of 
people, caUed tbe Moravians, whoi sdicited and 
obtained it, in order to convert to their way of 
thinking the few inhabitants who had settled 
along the sea coast ; but they soon discovered a 
more material advantage in cultivating the fur- 
trade, which they do at present to a very consi- 
derable extent About ten years ago, another 
unlooked-for source of wealth started up, and 



NOIIB VII. LABaApom ao€&« 05 

whieh> if it had been properly managed^ would 
have proved Utile worse than a silver wu^. 
Some of the English settlers, vralking along the 
borders of the inland riversj observed particular 
stones of a shining opaline colour ; these wheti 
slit, or cut in a mill and p<dished» disj^ayed all 
the variegated tints of colouring that are to be 
seen in the plumage of the peacock, pigeou^ or 
most delicate humming-birds. Some of these 
beautiful stones being sent as a present to thm 
fricinds in England^ soon attracted the notice of 
the lovers of the fine prodiictions of naturCj who 
bought them up with avidity. From England 
the same desire spread all over Europe^ aad 
every collector was unhappy till he could enrich 
his collection with specimens of different <^ 
loursi which are no less than seven, often mix^ 
with varying tints a«d shades. Sonde of th« 
larger specimens have four distinct colours upon 
the same slab ^ but more gjeiieeaUy each stpoe, 
as found in the lumpj has its own particular cx^ 
lour, and which most coEUBonly runs through 
the whole. The light blue and gold is the most 
cwnmon ; green mixed with yeUow» is the nextt 
fire witb a purple tinge, not so common; the 
fine dark blue and silver, still lessi and fine 
scarlet and purple, least of aU. The largest spe- 



^g t>011AXir IX. AHOMALOUS. 

oimens yet discovered are about three feet in 
circumference ; and all over one continued gleam 
of colour. I have seen many blocks of it greatly 
larger than the above, but they had only spots 
of colour here and there, thinly scattered. The 
first quantity that was exposed in Edinburgh, 
was in the year 1790, in a ware-room on the 
south bridge, by one Shaw, from London, a 
native of Aberdeenshire, who, I think, keeps a 
shop of natural history in the Strand ; and was 
the same person who sold that wonder of nature, 
the Elastic Stone, to the Honourable Lord Gar- 
denstone, and which his lordship, with his usual 
goodness, sent to the ingenious Mr. Weir, and 
now forms a part of his elegant Museum in 
Prince's Street, New Town, Edinburgh. Mr. 
Shaw again paid us a visit so late as November 
1792, when he exhibited some most brilliant 
specimens of Labrador spar ; particularly one of 
fine, extremely bright, and variegated colours ; 
one pretty large, of the scarce fire*colour with 
the purple tinge ; and one with gold, blue, and 
green shades : the first was sold to the celebrated 
Dr. Black ; the two last are in the elegant col- 
lection at Momingside. This beautiful stone, 
when analysed, is found to contain a portion of 
cidcareous matter, and some particles of silver 



VOMX Til. LABRADOR ROCK. ^7 

and tin*; some pieces bear an exceeding high 
polish, but Tery soft upon the surface, and may 
be scratched with a nail or file. Some natural- 
ists ascribe the reason of the beauty of the shades 
and colours, to arise from a decaying .quality in 
the stone ; however that be, it has been turned 
to no other use than specimens for the cabinets 
of the curious, and inlaying snuff-boxes; but if 
a proper quarry be found in Labrador, we shall 
have chimney-pieces of it, which will go beyond 
any thing the world has ever seen, as to beauty 
and elegance. The. highest price any single 
specimen has as yet sold for, is twenty pounds ^ 
but a much finer could now be purchased for 
half t1ie money. 

*^ John Jesms^ the Scotish fossilist, lately dis- 
covered a spar very similar and much resembling 
]tbe Labrador, in the shire of Aberdeen ; but it 
Qnly displays one colour, that is the gold tinge^ 
and is of a much softer consistency ; one of the 
finest specimens of which is to be found in Lord 
Gardenstone's cabinet of precious stones. This 
stone is arranged in parallel strata, which appear 
in certain lights to be of a greenish semi-trans- 
parency, and white opake, like the onyx, alter- 
nately ; in other lights, there are seen light tints 

* A strange ftiMlyit! 
VOL. II. H 



fif {^ brillt^fi^ g^<}^ ^ m^ a»m verjr mfitt 



9T90lK(nW !• 



Noble Lfbra^lor^ or opaline felspar. 
Mkrqnqmc Jf . Norwegian blue* 



Dticriptiau ^Th\% Pock> which^ if not the firsts ranks among 
the first in beauty, consists of round or oval peV> 
bles, or rather crystals, of various colours, in a 
siliceous cement, sometimes approaching to trans** 
parent quartz, at others itself a bricia of minute 
fiagtnents or crystals. The most cpmnion co« 
lour of the pebbles is grey, followed by the 
brown, black, dark blue; the more beautiAi!» 
yellow and red ; the rarest being the green. 
The cement Is also of various colours, fVom the 
transparent quartz to the opake red ; son^etimeg 
of a metallic yellow, perhaps from, disseminate4 
pyrites ; at 'other times tinged with yellow or red 

* The letter is signed A. S. Bee, xv. 99. A few copies of the 
account of gems were thrown off separately, by Dr. Anderson, for 
his friends } they are very Huti 99^. v%lip]ii1c. 



^irattad paitioular piebbie^* ^ or "ii^ iMttinet. pwii, 

adfiiag firom the influence of itbe oxydiof iron* 

i This is tfaa ceUbratbd pndding^slene of £ag^ pudding-ttom. 

Iand» so much is reqndst in fortignr ooanlries { 

bttt tbis n^me commonly ezcitittg a sniUcMvM^ 

fcbe ittiteitrte^ smd the mppeUatmi bei»g< etoce 

enlarged .to a grtat number of ^tenitea^ of a 

different nature and origin, forming 4ntit4 chaim 

of mountains (wluie this ia confined* to a tery 

aaiatt. district in Englandlt^d is feumd r» where 

else in the world), it has been thou^fit proper ta 

idirtingmsfa it by the nUiie of KoUasite ; derived 

ftom the Greek^,. dsaoling^ its. afipearaeett of 

beiBfg deiyieetad togetbeir^ 

The peliUes idso»..vriuch are ialaid in tto Nobitfiiaii 
lieanfiful sobstaocc^ seUfaoi belong' to common 
jiint^ 1mA. to an iDtehabdilrte kind,^betweeo flint 
and chalcedony, whieh^ in'ifae scnparfeetioii ef 
the. sdieBce, has not yet iMsa dkorMteciaadL 
£arsfteii,.iQ bia catalogue ef Ledce V ceSectiontt 
nieationedif mit^Mr tiie anawtia of Pokm^ 



« ^KcrXXA cement: it is alto used By Dioscoridet* ind othen« dor 
iron, which in the mineral kingdom forms an almcnt uniTeisal 
gimen. See Collini nir ie$ Agaiet, p. 166. 

In words front uit Oieek^ thv origkiaf and £n|^nh K if pRftntd 
t» theLadn and FmchrC. 

t ii. 471. 



100 aoKAUi new AvtmkLon§. 

ome fpecimaa^offlinti chiefly yellourorspotted^ 
which . most greatiy resemble to those in the 
KoUanite; and whichj as he obserres, ^preach 
exceeJMgly near to chalcedony. Many may 
also be .said to be agatised ; being disposed, Uke 
agate, in coacentrio lines of different tints and 
colours. It i'a indispensable that a new term be 
applied to this intermediate substance; and the 
CbiHte. Greek name of Chaliteis proposed, from the 
word for flint, but which has not yet appeaif^ in 
mineralqgy*. 

To arrange these pebbies with common^ flints^ 
would only occasion a confusion of ideas. They 
belong to an intermediate substance, between 
flint and agate, which, indeed Hauyjhas'ar* 
ranged together, under the name of Quarla 
agate. That flint which is fomid near Pari^ 
with the. layers and beauty of an onyx, and that 
called meniKtey might also.be classed as different 
atructures.of this nobler kind of flint; which, as 
silez is from the Latin, might be sought,.as before 
stated, in a higher source, the Greek, and de- 
nominated chalite. like chalcedony or agate^ 



* XaXf^. The Hebrew, it b said, . is ckalamith. Readen 
Teised in that language, may cnosult Deut* txix. 16, Pft. exit. S» 
Ii. V. S8. L. 7* £sek. III. 9« 



to whi^h it sometimes passes^ aceordkig to Mr. 
KirwaBy it is often accidentally impregnated 
"with jasper. 

' These pebbles are often found detached, and, *JS^? 
of a.particular beauty ; which, wanting however 
tbe delicacy of some agates, resembles that of a 
rustic girl when compared with the elegance of 
high life. Some present circles and shades of 
various tints of brown, approaching to the 
Egyptian pebbles ; others, various concentric 
tines of yellow and brown, yellow red and black; 
and others display a centre of red or crimson^ 
with concentric bands of yellow and olive green. 
There is also a rare kind called the zebra, from 
its regular black bands upon a white ground. 
If we believe Dr. Woodward*, who made a very 
large collection of English pebbles, fine agates 
have been found near Gaddesden, in Hertford- 
shire, one of the boundaries of the pudding- 
stone ; where have also recently been discovered 
9ome fine flints with purple illinitions, like land* 
scapes, perhaps tinctured with manganesef. 
That industrious author informs us that the KoU 
laoite is common about Berkhamstead, in Hert* 

* Nat Hist, of En^ish fossib. 

f ColHni observes^ p- 146, that agates are easily detached from 
the rocky because each is enveloped in iron ochre. This t^ooKk 
applies to many koUanites» 



fordshtrey'UlM^ it is called the breeding^stfue; 
^^^ Thi8 b alao the case at St Albans (which, witb 
its vicinity as far as Market Street on the nortby 
may be regarded as the chosen district of the 
most beautiful KoUautte)^ the name arising* 
from the common idea that this stone breeds, or 
produces successive pebbles. The breedings* 
Hon^ must, however, be distinguished £t>m the 
mather^tane, of the same county ; which is an 
iron-stone, with pebbles of quarts, deposited in 
layers above the chalk; and sometimes approach«% 
iqg the surface, renders whole fields bamsD. Dr. 
Woodward also says, that at Aldenham, near 
Watford^ Hertfordshire, this substance, tfaiere* 
calkd pudding-stone, is very frequent; and some 
masses weigh near a tcm$ nay, he mentions a 
mass of three tons, at Comer Hall, near Berk- 
hamstead ; and that labourers about St Albans 
speak of masses of a similar size^. 
Sites. From personal inquiries and observations^ ifc 

appears that the fiiirest pudding-stone is chie^ 
found at the ancient and venerable town of Sb 
Alhans» where masses often occur hi the pave« 
uKut ; and its northern environs, as fiur as Masw 
ket Street, where it also forms a great part of the 



• $it(» o£ Httl^ coiuoquQnc9» or <u^cQneDU4« af^eajc ts be Tvo. 
Watfw, West Wycombe, the county of ficdu* &cu. 



1iBm% tiff. K4t3AUiTi^ ii^ 

f^itmeAt The tnwsoni bf that tittle, iiot 6b-» 
«ch*yihg Hh beauty aad diti^lajity^ hate dftell 
nthted it i^^itb totbtnon flifit, as it atehr^ in th^ 
neighbouring quarries, in the walls of the Abbey 
Chuteh and its precincts, and in those of the 
ntinnery of SopWdl. The author etefn fbund si 
tt(« kpot called Gorhattibuty Blodk, a pieci) 
^hich h^ fidten ftoitt the Rmiatt tirklls ef 
Yernlata ; being flat^ like n RMMii hiltk, WftK 
nobMf toortiHT adbefetil But w a be^utlftil and 
valuable stone, it seems to httte beon iinknowib 
till the seventeenth century; 

It is also said to hdve been dbs^rf ed )n tfie htA 
of the forer Lea, at Luton. Th6 Ingenious Mr. 
. Putkidson, whos^ Woik on pettifaMions is W«ll 
known, ohiitvti iti fi letter f& the sttthdf, ^ thai 
towards Ware^ in the south-east, and fr6M 
Amersham to Kiiigs Lahgley, 06 the south* w6st^, 
I have sought for it in vatn ; but between Hemet 
Hampsteiul and Trhig, I hare seen large nia^s^^ 
whi£h I suppose hatef been diig up in that li^igh* 
biWthood. Th« Unit eoiMa;)m<i^ Alcy^fnta, fttrv 
tfteses lAotrt AilMrsbatfi ; aftd soon aftery t hi- 
lieve^ rather more to the iioffh/ commences thtf 
]^dding-stone." Iii sfacM, if we USke a line thwt 
St. Albdns in th6 south, tS jtfarket Stfe^t ifr f he^ 
north ; and from Tring in the west, to Hatfield 
in the east s we' fthaU hmd an o&l6ng*square, of 



104 DOMAIN IX. AHOPAI.OU8. 

about 20 miles £• and W. and about 10 N; and* 
S. which may be indicated as the peculiar dis- 
trict of the KoHanite, or precious pudding- 
stone. 
sheUa. Shells, or strong and marked impressions, have 

been found in the very centre of masses *of Kol- 
lanite, which with its superincnmbence on 
chalk (where however it only forms detached 
musses, like those of siliceous sandstone, or gra- 
nular quartz), have been regarded as proofs of 
its recent formation.' 

On Barnard Heath, near St. Albans, along 
with the masses of pudding-stone, which them- 
selves always appear to have been rolled, may 
also be found bowlders of black jasper veined 
with white quartz, the siliceous schistus of Wer- 
ner, with others of red jasper, of granular quartz, 
and even of rock crystal ^ so that the position 
would argue little, while the shells alone would 
evince it a secondary substance. They are 
commonly small chamites ; and, *it is believed, 
have never been discovered in the finest kinds. 

• • ■ 

Mr. Parkinson* has observed, that the numerous 
pebbles found in gravel-pits, &c. have seldom 
been rolled i but, on the contrary, their present 
forms are precisely those which they at first de^ 

* Organic Ranains, i. t83. 



aroMK vxiL kollamiti. tOfl 

riyedfrom the siliceous impregnation of several 
•nimals, which existed in the primeval waters. 
He supposes that the pebbles were at first soft 
nodules of martial clay> or marl, often composed 
of lamiuas of different colours ; such, as he says, 
have been frequently found in the gravel-pits of 
England, and in large heaps in various parts of 
Italy. They are afterwards impregnated with ^'jj^centf" 
siliceous juice, which may be of very recent, 
origin ; for silex is soluble in water, as appears 
from the analysis of nqany medical waters of 
England, not to mention the fountain of Gey- 
zer in Iceland : and Mr. Davy has shewn that it 
enters into the composition of the epidermis of 
many reeds, and even of oats, wheat, barley, and . 
other graminous plants ; that of Dutch rash, in 
particular, seeming to consist entirely of silex. 
In stacks of burnt hay, there are found porous 
stones, resembling frits of glass. From these 
examples it can scarcely be denied that silex 
may often be produced from decayed vegetables. 
There may, however^ be two formations of pud- 
ding-stone. The celebrated Fracastorius was 
the first neptunist, as he was the first who in* 
ferred fossil shells were not lusus natura^ but 
formed by the primeval waters which covered 
the earth. But if these shells existed even in the 
primeval ocean, it would be difficult to assign 



106 MUaiw fk; AirdkALdtfL 

th« precise flpoeh of tb^ir creation ; aifd tbnft ft 
few shdlld itiight iippeai^ eiren ih substanted styled 
primarjr. 
<Hggn of That patient atid cfal^fdl obsetire^ SaussuM^^i 
has dstablisbed as an ^}otti» that pebbles oA^ 
ginally so fomied, Mi4 fidt produced by attrittefti 
may be distiilgaish^ by their conciehtrio layei^r 
or by a tlodtile^ whose fortti correspotids With 
that of the stone i thtts what he cMs pettoiilet i 
^c^rdd, or with a Hnd, is a flint found in nuturtll 
nodoles, the rind being fh)di six lines td ah incfb 
in thickness, of a gf ey Almost opake ; whilAt tbd 
concentric kernel is of a fawn^colottr, and iiim\^ 
tMinsparentf. 

With regard i6 fiAltd pOihle^i the Mndy Of 
which he has particularly recoiiin^nded, 6s per* 
baps ntore essential to tbe theory c^ fbe eaitb 
than that of the rocks thetnselres, Sadsstire hM 
remarked, and the obserration has since beett 
repeatedly confirmed, that the pebbles of the 
Yitles among mountains are derited ffoitt the 
rocks of which these mountains consist; but th« 
pebbles of the ki'ge open pMns seetti m if 
dropped from the sky, no parent rocks appeiaing 
in a space of hmidreds, and ^en of thousands 
ijf mfilesj. It would seem, from many circuttM 

• §S(I4- t§I5(to. tf?17. 



ttanoM, that wUIe the priibcf?al waters covered 
this globe, noipartieular oceans nor seas e9cisted< 
Hence the currents of the chaotic ocean, of faf 
BBoie force and activity than we can at present 
conceive, have rolled these pebbles from im^ 
■sense distances, as products of Florida are by 
the golf stream brought to l^ewfoundland, and 
even to Shetland and the Orknejrs^ De Luc has 
observed, that the stones scattered over the con^ 
tnients form a principal geological monument j 
and any theory which passes this phencNnenon 
hi silence, can deserve but little attention from 
the real naturalist** So tme it is that the plains 
are more difficult to illustrate than the moUn* 
tains; and he who can explain the formation d 
a pebble, may eaqplaia tlie formation ofdM 
globe. 

Doctor Kidd^ observatiofis on the pebbles of 
England, deserve particular notice on this occa* 
sion*^* 

^ The target massea bk m many parts of 
BaglaDd called bga>lder stones, a name expressive 
of the cauae of tbeir rounded form : the term 
peM^y n in cofbmon language applied to those 
wkiok are smaller than She foregoing, but too 
huBgeto be used as gravel ; and these ar^ vwy 



103 DDKAIN: IX. iJIOMAI.Oir4. 

commonly employed for the pofrpose of poring 
court-yards- of houses, and the streets of small 
towns. Common gravel is too familiar to meed 
any description. P.ebhles of the smsdlest dimeii* 
sioiis constitute' coarse sand. 

*^ The gravel immediately round London ap* 
pears to c6ns^st almost entirely of the black flint 
met with in the neighbouring chalk strata : the 
pebbles are in general very uniformly worn, and 
have to a greater or less extent lost the charac- 
teristic black colour of the flint, from which 
they are derived; but sufficiently correspond 
with it to shew the identity of their nature. 

<' The gravel round about Windsor and Maid- 
enhead consists also, in a great measure, of the 
. flint of the surrounding chalk-hills s very much 
discoloured, but not much worn. It appears, 
however, that that part of this gravel which is 
nearest the surface is not of the nature of flint, 
but in its texture resembles a highly indurated 
sand-stone : and it is obs>erved that these pebbles 
are much larger than the flint pebbles; and^ 
though considerably . harder, are much more 
uniformly rounded. They have probably, there- 
fore, been conveyed from a greater distance $ 
and judging from their relative ^itu&tion, for 
they are found nearest the surface, they have 
been deposited mpre recently than the flint. It 



VOME Till* KOLLAXITC/ 109 

n worth' obsenring, that pebbles of this kind am 
met with in almost every part of England. I 
have collected them from very different points 
along the course of the North Road, both on the 
eastern and western side of the island : from. 
Nottingham, York, Durham, Edinburgh, Lan-* 
lurkt Carlisle, Chester, Shrewsbury, and Wor* 
oester; Aod have obsenred them in many othi&r 
parts. 

^* The gravel met with immediately • round 
Oxford consists principally of small siliceous 
pebbles ; many of which are flint, mixed with 
worn fragments of fossil calcaceous shells, and 
brown iron-stone; the presence of ^ all . these 
tabstanees is accounted: for by the nature of the 
aunkmndihg country ; the limestone of that dis-* 
trict abounding with fossil shells, and many of 
the neighbouring bpHs consisting either of chalk 
containing flint, or of ferruginous sand< contain* 
ihg brown coarse iran^stone." . 

But it is time to return from .the consideration 
of the pebbles, to that of the rock under view, 
which has alw* been called a pebble«stone by 
aome authors. 

That there v^y be no suspicion of national 
prejiidtce, ia the account of this, singular rock 
(which not only surpasses most ^others in beauty 



9Hi. vfiriekjr> but afiurdi many imporiaiit lortDm 
m g0ology)> we 6haU traodate the description cf 
FfttriQ ; who had not duly inspected the richul 
eabiaots of Earope^ bat had resided toe ei^ 
jears in Russia and Siberia^ which affordiM] 
e£ the most heautifui miiieral siabstaiseesu 
Mito << The most} oeldbrated poddia^stime,' 
which QD aceount of its beanly obtaiaa 9 
in all cabinets of mineralogy, is fonnd in MWf^ 
tiver» of Scotland^ in small roHed maasea^ which 
aie seldom more than five or sice inchM in dietaei^ 
ter.. It is generally known by the name of ihn 
poddiQg»8toiie> or pebUe of England, 

^^ It i& farmed by ao assemblage of smallaiK* 
oeoua stones the interstices of which are fiUed 
by gravel and very fine quart3sy sand. ThewfacAe 
la untied by a aUiceous gluten, of an epake winte 
aolour^ wUeh ia nel easily pereeplihle withooft 
the aid ^f a lensu 

*^ The pebbles which ecanpoae! diia beaaftifai 
piftddiog'^atone, are at moat of the sice ci a wal- 
nut, and ofitoier of that of a bean or a& almondi 
Thegr are caknured with mrioos tkria, but with a 
^ remarkable singularity ; for these caloHvaredi» 
poeed in concentrio layers^ It qeems thisa. that 
tiJMflie pebbliBis.are little flhsts». wUcb bavie bee« 
fiirmed sack asi thmr aie> but in aMtber matyiir 



.noifi vstb soLicAirinc 111 

fiwtt whaiee they hwe hceii detadhed by Ik* 
waters^ and afterwards ag|^utiiiatad hy Abquartf y 

^* The cimteftlne layers wls^h ate obmr^ id 
tbeir iateFior» seen) to demonstrate tjuuk it is not 
toiriotinD and rQlling that t)iey ar^ inddkt^ for 
their roimd appaaniQce; li qy€»i af^pears that 
tbeif prifdilive form has hwv^ no waya altered ; 
fon the iaterior layora are no% mily pamlld 
among themselves, buft even >dwaya parallel to 
th^ abrfii^e of )fhe.s|xme» whatevi^r way.be its 
ehl9>e. It is not unebiQ9iQB tq ohserM soom 
^b'c^b are triangular, of vihieh the iateriar layarf 
funeflent several triangles> one within' the other, 
Mid always pamllel ta the surface of the^ stone. 
The »ost «unmon cobnr of thesa lajrera, in 
yeMoiv, md« while, and bhiish ; this letter tiak 
is generally that of the surface of these little 
'{»bhlea« 

. f ^ Thieie is ' a circuHirtanee -mkiclh . ^eems to 
prove that thego atones have net Veqn tossed 
about by .tho waters for any long. tMO^ it is> 
that.ilibqp are ahnost always, observed ndnglei 
wlk ficBtgments of ^int, att the angles of wihieli 
are sharp. 

<< With this pudding-stone are mad^ bcpvs, 
trinketi^ aisd baantifiil )ij^ ah^ whkh b\y t^e 



llj^ VOMAlsr IX. AHOMASOUi. 

rariety of their colours^ and the vivacity of their 
polish,, arejufinitely i^gteeable to the eye"* 

Brard's account is as foliowsf : '^ The pud* 
ding'Stone of Englaird is cbmpdsed of little peb- 
bles round,' oVal, o'r elliptic, of the siise of aa 
olive, brown, grey, or yellow, imbedded in a 
cement of a grey, or of a chamois coloan 

'^ This pudding-stone, which is highly esteem* 
ed in jewellery, is found in rolled fragments in 
certain rivers in Scotland. 

<< Although the pebbles, and still less the oe* 
ment of this puddings be not of a very fine 
paste, it nevertheless takes a most beantiful po* 
lish. It is wrought in many works (^ decora* 
tion ; but is not fit for small jewellery^ such u 
earrings, necklaces, &c. It is used with: more 
advantage in making boxes, socles,' handles, of 
knives, etuis, &c;'^ 

He then proceeds to describe the pudding of 
Chantilly, which consists of fisir larger pebbles, 
of a deep yellow, bordered with a bluidi Uack» 
in a cement of quartzose sandstone. A finer 
kind is found near Chartres, in the department 
of the Eure and Loire, composed of very sadaU 



• in. 350. 

t Trait^ des pten«s prcdeiuet^ i. 18S. Rais 1808, S f«U. Svo. 



mourn rnu kollavitb; 113 

brown And black pebbles, united jn a silex of a 
yellowish white. The pudding of Rennes, which 
he subjoins, has been shown by Patrin to be 
merely a spotted jasper. That of Chartres must 
be also the same described by the acute Patrin, 
as merely an oculated silex, a keralite, or horn-* 
stein of the Germans. 

The pudding-stone of England, therefore, re- 
tains that singularity of composition, which has 
diffused its name through all languages, and 
been admitted in all works of mineralogy, in an 
awomed contradistinction to bricia^ which con- 
sists of angular fragments. 

But the learned and sagacious I^atrin is him*^ Commoii 

piiddiitt"ttoiM» 

self mistaken, when he says that the pudding- 
stone is found in the rivers of Scotland. It is 
true that a rough pudding-stone, composed of 
rolled pebbles of granite, porphyry, clay*8late, 
quartz, trap, primitive limestone, and other ori- 
ginal substances, in a cement generally ferrugi- 
aoQS or argillaceous, accompanies, on both sides^ 
the Grampian chain of mountains, as it doei 
that of the Alps. It sometimes, as Faujas has 
observed, , even contains green porphyry, and 
green trap, and thus approaches to the iamoui 
uuiversaL bricia of Egypt. But these Scotish 
locks have only a slight resemblance to the pud- 

\OL. lU I 



214 DOMAIN IX* AHOHALOVS. 

jliag-stotie of England, ba shall presently b^ 

• Brard is also mistaken when he asserts that 
the paste is not fine ; for, in the choicest speci- 
inens^ it is of surprising fineness and delicacy. 
Koiianite It would appear that this beautiful stone is 
^E^^bmd. quite unknown in other regions. Walierius has 
described it as a rock, composed of various flints, 
and England is the only country he mentions* ; 
for those of Rennes, in Normandy, are, as Patrin 
has shown, only spotted jaspers. Gmdin, in 
the last edition of Linnaeus, has described pud*» 
ding-stone as consisting of fragmehts of petro* 
silex (homstein) and quartz, cemented byjas- 
per» He says that it is found in England, aad 
also up6n the Rhine and in Bohetaia, assuming 
to exquisite polish, being variegated, but the 
jasper generally of a brownish red ; and is used 
fbr vas6s» bnd various kinds of ornaments. His 
description may apply to that of the Rhine, as 
jsontaitiing kernels of reddish brown jasper, and 
that of Bohemia ; but is quite foreign t^ the 
fingUsh pudding'^stone. 

Mr. Kiirwim, disgusted with the vulgar nande 
1^ pttddin^stone, derived from the resemblance 

• i. 444. 



frOHB Tilt. KOtLANITS. 115 

of a common kind to d plamb-ptfddingi c6m« 
posed of flour with raibins and corihths^^ ^nd 
which being strictly descriptive, hite pasi^cd intd 
all languages, is inclined to prefer the Lati^i 
farcilite of similar import ; but the Greek KoU 
lanite is preferable, the Latin having passed into 
the dramatic farce^ which ekes out the enter^ 
tainment like the old Roman ./irrr/wiew, or pud^ 
dings. He quotes the miners' journal, publii^bed 
in German, for a mountain of farcilite ot- pud^ 
ding*stone, in Siberia, near a rivulet citlled Tulat, 
consisting of rounded fragments of jasper, chal- 
cedony, camelian, and beryl, in a quartisy ce^ 
mentf. This he considers as primitive; but 
among the secondary rocks, quotes the same 
passage, only omitting the beryl, which indeed 
seems foreign to such a substance. Even this 
can scarcely rival the English pudding-stone in 
beauty and variety ; and, if it consists of round^- 
JtA or rolled fragments, must be of quite a Axftot^ 
ent nature, as shall presently be explained. 

The errors of foreign writers, concerning this 
singular and beautiful production of £ngland> 

* A unall gfBpe originally from Gorinthi but now chioflj io^ 
ported from Cephalonia and Zante^ and which has been used for 
centuries in the English kitchen. The French have no puddings, 
the houdin being a hog's-pudding. 

t Geol. £is. Sl«, 

12 



l\% DOMAIN IX« AHOMAIdOVt. 

will appear the less surprising when we consider 
the following description, just published by the 
learned Dr. Kidd, professor of chemistry in the 
University of Oxford^ in his account of what he 
calls pebble*stone^. 
Kidd's ^< This term is applicable to a numerous class 

scconnt* 

of rocks, &c. consisting of pebbles of various 
sizes and colours; which are irregularly con- 
nected together, either with or without an inter* 
mediate substance ; and it is presumed that the 
.cemented particles are pebbles, or have acquired 
their rounded form by attrition, from their uni* 
form smoothness. 

^* One of the most striking varieties of pebble- 
stone very commonly occurs scattered in large 
masses over the vale of Berkshire ; it consists of 
numerous oval pebbles, of reddish black flint, 
very much resembling raisins when swelled by 
boiling, cemented together by means of indu^ 
rated sand, of a brownish white colour. The 
whole appearance of the mass has given rise to 
the term plumb-pudding»stone, in this country ; 
• and the resemblance that gave rise to the terav 
is so remarkable, that it cannot fail to strike the 
mind upon the first view. The term has been 
very generally adopted by foreign mineralogists; 

ft 

* Outltacsof Mineralogy^ I8O9. App. p. SI. 



HOME VIII. XOI.LAKITB. 117 

who> howerer, commonly call it simply pudding* 
fttone» or English pudding-stone (ponding^ of 
Brochant; poudding Anglais^ of Hatiy). Fo* 
rei j^ers also seem to apply the name to varieties 
of pebble-stone in general. In the pebble*stone 
of Berkshire, the cementing substance is often 
so highly indurated, and so firmly adheres to the 
pebbles, that upon the application of a sufficient 
degree of force, the fracture of the stone is car- 
ried on indifferently through the pebbles as well 
as the cement; in some instances the fracture 
takes place in such a manner as to leave some 
of the pebbles half imbedded in the stone, and 
half projecting from the broken surface ; which 
probably depends either upon a considerable 
difference in the hardness of the pebbles, and 
the cement at those parts ; or upon a slighter 
adhesion than usual between the two. 

'' In some instances the cemented particles 
are angular fragments of pebbles. Both varieties, 
when the cement is sufficiently hard and com* 
pact, are capable of a very beautiful polish. 

<^ With respect to pebble-stones in general, 
their appearance is as various as ean possibly 
result from a variety in the colour, form, size, 
and degree, and mode of union, of their com- 
ponent parts. The hardest I ever met with, oo* 



|]3 DMMN »« AVOMALOIIt. 

curs in rolled fragments in the bed of the Esice, 
near Rosslyn Castle: it consists of numerous 
differently coloured particles, some resembling 
ted jasper, very compactly aggregated without 
i^ny intermediate substance.'* 

This last may either be a spotted jasper, or a 
jasper bricia. 
Accontranies The coarse pudding-stone accompanies at in^ 
tervals the vast chalk stratum of England, whose 
lindulating outline, from S. W. to N. £. may be 
computed to about 600 miles. This coarse pud<^ 
ding-'Stone consists of common flint pebbles, 
sometimes united by an argillaceous cement, 
sometimes by a ferruginous, at others by an 
firenaceous rendered coherent by oxyd of iron« 
The red gravel which affords such an elegant 
contrast with verdure^ and is well known for its 
binding or coherent quality, approaches nearly 
to the latter kind ; and masses of such pudding- 
^tone are frequent in gravel*pits, even in the 
neighbourhood of London* A large mass may 
be seen in the lane, which ascends from Kentisi^ 
Town to Kenwood, to use the orthography of 
Lord Mans6eld, derived from its ken, or widie 
prospect. 

But the precious kind, which has acquired 
such celebrity all aver Europe, for its beauty. 



JIOHB VIIX* X0X.LAKI71.. VISt 

variety^ and pleasing accideintfl, not obl^y^ldo 
in any other rock, seems confined to thQ district, 
of Hertfordshire abo?e niftntioned* 

If the term pudding-stone be r^stripted tOi 
what the Germans would call an agglomeriEUed^ 
substance, it may even be doubted whether it b$ 
properly applied in the present instance ; ibt it 
is not only clear, as Patrin has remarked, that 
the pebbles never have been rolled i but, frwn 9m 
accurate and minute elimination, that the whoto 
is an instantaneous composition, a kind of dis<* 
turbed crystallisation, like granular quarts ; or, 
as in the stones called glandulites by Smissureji 
as containing nodules of a finer or coarser graiii«^ 
It would seem that an intrusion (tf iron and 0lay» 
or what is called jasper, has imparted this p^cu^ 
liar appearance, as iron often ipo)in^« to thfi 
pisiform and fabiform. Or it may be that in % 
sUiceotts sediment the iron asserted its predQfn^ 
nance and affinities, to assume the$e $ingi4)Ar m^ 
beautiful forms*. But geologists mi^bt compose 
whole treatises on this rock alone ; whi^b m^^ 
be as important towards a theory of the furtbi^ 
as Saussure Sound the noted puddiag-stone Of thft 

* On the influence of iron in such formations, see CoUini's inge- 
nious little work on the Agates of Oberstein. Manheim, Y776» 
12mo. p. 126, scq. 



120 BOMAtV IX* AROUALOU8. 

Alps^ whose vertical position led to bis theory of 
refoulements. 

A shell of the cockle kind, as already men- 
lioned, has in one rare and solitary instance been 
observed in one of the pebbles ; and in another, 
imbedded in the cement of the stone; which 
might, in the language of Werner, indicate that 
it is a transitive, if not a secondary rock. But 
this would not argue against its coetaneous 
formation, any more than the shells found in 
jasper, and many siliceous substances, 
r The varieties of this curious rock are almost in-* 
finite; audit is diversified with almost every shade 
of colour, except perhapis pure blue and green, 
the former of which does not occur even in the 
finest Jaspers; but the latter, which is common 
in that substance, may probably be discovered 
when persons of real skill observe the sites of this 
remarkable rock*. Agate only presents single 
beautifiil pebbles, of a more fine and waxy ap- 
pearance, and often with more outlines; but 
here numerous pebbles display such various ac- 
cidents, that in a large polished slab no two 
would be found exactly alike. Some have the 



* I am since infonned^. from undoubted authority, that the green 
exists. 



KOMB Till. KOLLAKITS. 131 

I 

concentric zones of a^te> while others are 
spotted in infinite variety ; and others, though 
rarely, are nnicoloured. The beautiful marble 
bricia of Aix seems of ^ similar instantaneous 
formation, and approaches the nearest in point 
of variety, but is far inferior in tints and polish; 
^or can a comparison be instituted with others 
the most beautiful amongst the rocks ; such as . 
blue and green granite, serpentine, miagite^ 
Qiolite, corsilite, jasper, or even lazulite, which 
only present a few colours, and little variety in 
the texture ; while here the colours and variety 
Are infinite, and accompanied by the constant 
discovery of minute beauties and accidents. 

As not only foreigners, but even our own 
writers, seem strangers to the varieties of this 
stone, it may be proper to specify a few. 

1. A KoUanite of g^ey pebbles in a grey ce^ 
ment, the pebbles being sometimes lighter, some- 
times darker than the gluten, which is purely 
siliceous^ and of a more shining or unctuous 
lustre than the nodules. This is the simplest 
appearance of the substance, and never esteemed 
worthy to be polished. 

2. Nodules of a blackish grey, with some of 
transparent yellow, imbedded in a fawn-colour 
cement; consisting either of granular quartz, or 



133 X>0¥AIV IX* iLirOHALOVt. 

rather, as would seem, of ipiante sand, penetrated 
with siliceous liquor or pure quarts. 

d. Little dark grey nodules, in a lights oe-^ 
ment, of a yellowish white. 

4« A fawn-colour cement, in some places in- 
clining to white, in others tinged with red, and* 
ttudded with chalite of bluish grey, pate brown, 
lead colour, all inclosed in black ^ones, with 
one large nodule of a fine light lilac spotted with 
white, surrounded by a broad zone of yellow, 
which is followed as usual by an outline of black*' 

5. A slab, polished on both sides, of six inched 
square, containing great varieties of brown and 
yellow chalite, often with zones or tinges of 
Klac, purple, and a faint olive green. Many 
are spotted^ with various tints, while others havtf 
numerous zones, like agate. The whole in a 
cement of cofarse sand, of the same nature, aggln»> 
tinated by transparent quartz, so that the sub-^ 
stance^ appear as if seen through glass. A large 
pebble, of three inches by two, presents a sin* 
gular accident; a large portion of the cement 
appearing in its centre, in such a manner as to 
leave no doubt that both were liquid at the same 
time, or must have crystallised together. The 
white pebbles have more the waxy appearance 
of chalcedony than of flint. 



6. A detaohed large pebble, with a stnall ad* 
herent portion of the real kollanite, or precioua 
pudding-stone. This beautiful pebble, which 
rivils or exceeds the finest jasp-agate, is encir«^ 
cled with a brown zone, followed by one o£ 
crimson, the middle of a fine variegated brown,^ 
8<wietimes inclining to yellow, bearing near the 
eeotre a spot about half an inch in diameter, of 
a bright orange inclining to scarlet. Detached 
pebbles, agatised with red and white, and with 
other beautiful accidents, are sometimes found 
on Hampstead Heath, and many other places. 
They are quite different from rolled pebbles, and 
are oflen of a flattened, sometimes a kidney 
form, like those in the koUanite. Their exterior 
appearance is of a brownish black, with little 
lineal indentations, as if encrusted. They are 
called by the lapidaries English pebbles, to di»« 
tiuguish them from what they call Scotish peb- 
bles, which are generally of an impure agate. 

7. Pebbles of yarious tints, but chiefly yellow 
and brown, in a whitish cement. The singu« 
larity of this specimen, which is about 6 inches 
by d, is» that a little stream, as it were, of a light 
brown cement, and about an inch in breadth, 
tuns down the middle, bending byjthe side of a 
very large pebble. In this stream the pebbtea 
are all parallel with its direction, as if conveyed 



124 MITAIV IX. AHOMALOOK 

by it, while those on either side are iii perpen- 
dicular or contrary directions. 

8. A specimen, about two inches and a half 
by two, containing about thirty small pebbles^ 
of the most beautiful tints of red, black, brown, 
white, and cream colour, mottled and zoned m 
every conceivable form, in a granular transpa* 
rent cement, which however inclining to pale 
red, affords not the strong contrast which a &wn* 
colour would have produced. 

9' A piece, about four inches by three, pre* 
senting on a fawn-colour ground only ten or 
twelve pebbles, of the middle size ; one of the 
purest uniform carnelian, with the usual black- 
zone, and another of a fine purple red, or wine 
colour; while the others, chiefly red, are va« 
riously agatised and mottled. A singular acci- 
dent in this beautiful specimen is, that a lai*ge 
red nodule is split in various directions, yet the 
fragments perfectly preserve their position, the 
chiief rents being accurately filled by the fawn* 
coloured cement. 

10. A mass, about eight inches in diameter. 
In the heart of a yellowish brown pebble, with 
a broad black border, and about three-fourths of 
an inch in diameter, is the fair impression of a 
little chamite, about a quarter of an inch in dia^ 
meter. 



VOKI TXZX. BLOLLAWITE^ 1£5 

In this piece may also be observed a very 
large pebble, split in two, but not displaced, the 
crack being filled by the cement, which is of a 
dall white, or light grey colour, A pebble, with 
a portion of the cement in the centre, and every 
where inclosed by the substance of the pebble. 
Another, with the same circumstances. One 
pebble, with a cavity containing small quartz 
crystals. A pebble, in the state of indurated 
clay, and easily cut with a knife, being enve- 
loped, but not penetrated, by the siliceous mat* 
ter. 

11. Very small delicate pebbles, of a bluish 
grey, in a straw-coloured cement. 
* 13. Cement, half red, half yellow, with dark 
pebbles. 

13. Yellow and red pebbles, in a cement of a 
whitish grey ; but tinged with a fine red on the 
side of some pebbles, and with yellow near 
others, as if the pebbles had yielded a part of 
their colour when the cement was introduced. 

14. Pebbles of white quartz, in a deep red 
cement. 

15. A beautiful piece, found in the ruinous 
part of the abbey of St. Albans. Cement grey, 
with delicate tinges of red and yellow. Of the 
larger pebbles, one is yellow, with spots of red ; 
others yellow, with zones of white chalite, and 



.}S6 mouktn IX. anokaloui. 

small lines of purple ; and one may be styled 
agate, or cbdcedony^ being white delicatdjr 
tinctured with red and yellow. 

16. Fine red pebbles^ in a cement of a darker 
red. The contrast is not however sufficiently 
strong ; and the lapidaries in this case say, that 
the pudding has too much wine. 

17. Dark grey and black pebbles, in a cement 
of a delicate dove-colour. 

18. Brown, yellow, and red pebbles^ in a ce»> 
liient of an ash gre}', which only admits a dull 
earthy polish, while the pebbles are of great 
brightness. 

19. Very small pebbles, of almost every co^ 
lour, in a bright yellow cement Exquisitely 
beautiful. 

20. A pebble, about two and a half inches by 
one and a half, which is not only a pebble but 
a koUanite, as it contains distinct agatised peb» 
Wes* 

When the original sites of this stone are ex* 
amined by persons of real skill, it is probable 
that a vast number of interesting varieties will 
be discovered. Meanwhile it is hoped the reader 
will not blame some degree of prolixity concent 

* Those only are described which are in the author's ooUection, 
or which he has himself seen. The rare green probably contains 
green pebbles in a yellow cement. 



nous IS. TOfAt BOCK. iQf 



ing this singular substance, which has nev^r been 
carefully examined, and concerning which so 
many errors have been propagated both at home 
and abroad. 



NOME IX. TOPAZ ROCK. 

This beautiful anomaly is hitherto only known 
to exist in Saxony ; and Mr. Jameson's descrip- 
tion shall be copied, as it is probably the most 
authentic. 

<^ 1. The remaining primitive rocks we have 
now to describe, are less important than those 
we have already described, because they occur 
less abundantly, and not so widely extended. 
One of the most remarkable of these is the topa^ 
rock, which is not only remarkable on account 
of its constituent parts, but also its structure. 
It is composed of quartz, topaz, schorl, and a 
small portion of lithomarge. The quartz is fine 
granular ; the schorl thin prismatic ; the topa^fc 
iwually coarse and fine grannlar, and has com- 
monly a grey colour, which is to be attended to 
in its discrimination. These three fossils are 
disposed in layers, and thus form a slaty struc- 
ture; but this slaty structure occurs only in the 
small ; for these layers are collected into parti- 



128 DOMAIN IX* ANOMALOUS. 

cttlar. large granular masses^ so that the topas 
rock appears large granular in the great : a kind 
of structure which is termed slaty granular. The 
drusy cavities, that sometimes occur between 
these concretions, frequently contain regular 
crystallised topaz and quartz; sometimes also 
schorl and lithomarge, of the same colour as the 
topaz. 

** 2. Its stratification is uncommonly distinct. 
*^ 3. Its geognostic position has not been hi-^ 
therto satisfactorily ascertained. It appears to 
lie on gneiss, and under clay slate. 
• *< 4. It is a very rare rock, having been hi- 
therto found only in one place in Germany, near 
the town of Auerbach, in the Saxon part of 
Voigtland, where it forms a mountain mass of 
considerable extent, and is there known by the 
name of Scbneckenstein. A rock, composed of 
topaz, beryl, quartz, and lithomarge, occurs in 
the mountain of Odontschelon, and in the neigh- 
bourhood of Mursinsk, in Siberia, which resem- 
bles topaz rock, and is suspected to be the same 
with that of Auerbach, The schorl-rock of 
Cornwall is probably veiy intimately connected 
with topaz rock.** * 

It is truly surprising, that what are called the 
geognostic relations of so remarkable a rock 

* Jameson's Mid. iii. 141. 






JTOMB Z. JACIHT AOCK* ]29 

should not have been explained, especially as it 
stands in Saxony, the very focus of mineralogic 
knowledge* Henkel, as quoted by Patrin, says 
that the mountain or hill called Schneckenberg 
is near the valley of Tanneberg. The slope of 
the mountain is gentle; bat from* the summit 
rises, like a tower, the topaz rock, being about 
eighty feet in height, and three times as broad. 
But we are still to learn the composition of th« 
adjacent hills ^, 



NOME X. JACINT ROCK. 

A rock, which contains jacints, and which is 
itself composed of large white, greenish, and 
yellowish grains, consisting of quartz and of 
jacipt,so tbat it may be called jacint rockf. 

* Among the ejections of Vesovios there occnn what may bt 
ealled Chrytolite rock, that gem even sometimes sending as a base ; 
but these fragments, placed Jl>y Gmeiin among the locks, may per- 
haps be mere vein-stones, or may occur in small qoantities. Per- 
haps rocks of Corindon may be discovered. It ivas known to 
Woodward by the name of Telia Corwindum, and Nello Cori* 
pendtiM, 

t Sauss. § 1903. 



VOL. II. 



1S(^ DOMAtir IX. ANOHAUnrt. 



NOME XI. BERYL ROCK. 

This was discoyered in Fraxice» n^ar Limogest 
by le lieype. It had been used ia paving th^ 
highway, and is se^m of a good colour^ bieing 
generally of a greyish white^ thoagh some speci* 
mens offer a tint of green. It is however rather 
a vein-stone, though found in large masses, as il 
~^uns through the middle of a vein of quartz in a 
.granitic region*. 



NOME XB. GARNET ROCK- 

« 

The red garnet, of which this beautiful it>ek 
is chiefly composed, contains from 40 to 41 
parts of iron, according to analyses of Klaproth 
and Vauquelim The green garnet is even some* 
times fused as an ore of iron. 

In his System of Mineralogy, Cronstedt re- 
garded the garnet as entitled to a peculiar place, 
in the rank of earths ; a singularity which would 
seem to show that he had a distant view of the 

* Faujas, Geologic, Paris I8O9, vol. ii. part i. p. SOS. See parti«> 
cularly Journal des Mines, v. 641. The analysis of Vauquelia 
found the same ingredients as in the emciald. 



SOME a:it. GARNET SOC|K. 13 1 

necessity of introducing the ferruginous or side« 
rous among the other earths. 

This curious rock seems unknown in any sys- 
tem of mineralogy, except Mr. Kirwan*s, who 
saysi *' Garnet-rock of Karsten, found by bini 
near Winneburg : it consists of amorphous gar« 
net, in which trap, quartz, calcareous spar, and 
a very small quantity of blackish brown mica ard 
found/** 

'But the garnefc rock, recently discovered ia* 
Scotland, seems to consist of that matter minute- 
ly interspersed among siderite i^nd felspar, with 
larger or smaller globules, or imperfect crystalf 
. pf garnet. In some parts it seems to approach 
to slaty siderite, penetrated with gariiet ; a^ it is 
common for that schistus to contain garnets. 

The surface is brown from the decomposition 
of iron ; and the garnets ar^ of a coarse texture, 
and irregular form. 

STRUCTURE L 

Amorphous garnet rock, containii^ trap, qoarfe^ 
calcareous spar, and mica, from Winnebiirg. 

• Min. i. 368. The Scotbh may be the rock widi grains of garnet 
fimm Sweden,> Norway, &c Linn. ^ Gmelin, 883. The Saamm 
M^lmt GromUtctcm, colorv rac^eate, of Walkriua, fiom NiKUlkt i» 
Sweden. 



132 DOMAIV IX. ANOHALOUft. 



STRUCTUILB II. 



Garnet rock, inters[i6rsed w ith sideritei felspar, 
and spangles of brown mica, from . Portsipy in 
Scotland. 

' It seems essential to this rock that the garnet 
mc^tter should be dispersed throughout; otherwise 
gigantic and common garnets are sometimes so 
closely mingled in mica slate, that the rock might 
fall und^ this denomination. 
< The garnet trap of Saussure, § 2258, of abrownish 
green colour, composed of a mixture of particles 
of steatite, fibrous hcHtiblende, and mica, including 
many little garnets of a dull red ? 



NOME Xin. SHORL ROCK. 

This rock is chiefly composed of the common 
black shorl*9 the black tourmaline of Haiiy, 
whicb> according to Klaproth^ contains 22 parts 
of iron. It is common in: grant te, gneiss^ and 
other primitive rocks ; but is sonaetimes found to 
form a rock by itself, or mixed with quartz. It 

* The word is original, and not derived from the toyrn of Shorlatt, 
ts appean from the term Skirl, vatd by the Coroish mineri in the 
same tense. 



NOME XIV. ACTIMOTX X6CK. ]3S 

must not be confounded with the short en masse 
of Saussnre, and other French mineralogists, 
ivhich is siderite. 

Shorl rock is not uncommon in Cornwall ; the 
substance being generally, if not always, in small 
crystals, sometimes disposed in transverse radia- 
tions. ^ 

SnUCTURS I. SKTIRS. 

Shorl rock in small crystals from Cornwall. 
In very small crystals, elegantly fasciated in va- 
rious directions, from the same county. ^ 

STRXICTDRB II. MINGLED. 

Shorl rock mingled with quartz, from Cornwall. 

Dr. Kidd informs us that Roche Castle, near 
Bodmin, Cornwall, stands on a rock of this de- 
scription*. 



NOME XIV. ACnNOTE ROCK. 

Saussure describes^ § 2281, entire rocks com- 
posed of grey delphinite ; a kind of glassy acti« 
note. 

* Ontlines, i. 935. 



J34 IHOMAIV IZ. ANOMALOtTS. 



NOME XV, MARBLE OF MAJORCA. 

This rook fe of a singular and anomalous 
structure, as the shitpe of the spots, or concre* 
tions, resembles that of almonds. It is black 
and white, and takes a very fine polish. Th^ 
natives call it amandrado*. It is found near 
Alaro, in the island of Majorca. 



NOME XVI. MARBLE OF CAMPAN. 

This marbte, so well known in France, is 
found in the Pyrenees, not far from Bagneres. 
It is either red or green j and both colours even 
occur in a small specimen; but it is greatly con- 
taminated with argil, as before mentioned. It is 
ranked among .the anomalous rocks, because it 
often presents a singular structure, which may be 
called guttular, being disposed in oblong drops 
like icicles. These uncommon forms sometimes 
become important in a geological point of 
view. Rataibnd observed another marble in that 
vicinity, analogous to that of Campan, ^' tiant 
is to say, with a white base, veined with red and 

* Laboide 8 Spsdn, iiL 448. 



»6HB xni. PHOBmaftin. ]3,{ 

green by steatitic clays ; it contains a number of 
conical nodules, in which the different substances 
which compose it are rolled in a spiral form« 
and represent so many little distinct whirlpools, 
as independent of one another, as different from 
the flexions of the layers which contain them.''* 

HTPONOMB I. 

Red gattalar marble of Campan. 

BYPONOIfB II. 

Green. 



NOME XVn. PHOSPHORTTE. 

This rock is reported by some to form hills^ 
and by others only thick strata, in the province 
of Estremadura, in Spain. It is said somewhat 
to resemble curved laminar barytes ; and is of a 
yellowiflh white colour, often spotted with yel- 
lowish £rey. It is a combination of lime, and 
phosphoric aci49 the latter amounting to S4. It 
is rather soft, and brittle, and translucent on the 

Brochant says that its site is at Logrosan near 

* Samood, Voy. aa Mont Perdu* p. 99. 



136 OOMAIir IX. ANOMALOOS.' 

TroxillOy ID beds mingled with quarter and in 
rach abundance as to form a hill. It was known 
for a long time to. the inhabitants by its property 
of yielding a phosphoric light In 1788, Proust 
first indicated its nature^ in .the Journal de Phy» 
sique?^. 



NOME XVni. GLOBULAR ROCK. 

This anomaly was discovered by Saussure, in 
a hill not far from Hyeres, in the South of 
France. As his important work has nerer been 
translated^ aii extract may be satisfactory. 

*' On my ascent I observed, in the calcareous 
rock of the mountain, a hemisphere of 15 or 18 
inches diameter, entirely composed of calcareous 
spar, disposed in concentric layers, and each of 
these lajsers formed by an assemblage of needles, 
converging towards the centre of the mass. I 
at first thought it was accidental ; but, as I pro- 
ceeded, I saw with much surprise that the whole 
mountain, to its very summit, is composed of 
balls of spar, whose structure is nearly the same. 
Their bulk varies : the largest being two or three 
feet in diameter 3 the smallest, two or three 

* Mln. i. 585. 



VOMS Snil. OLOBULAX SOCK. 157 

inches: some are seen also ofan elongated form; 
but the layers are always concentric, and com- 
posed of parts conyerging to the centre, or to- 
wards the axis of the mass. Sometimes these 
layers, although concentric, are undulating or 
festooned. These balls, both the large and 
small, often intermix and arrange themselves in 
strange forms; and nevertheless the whole is 
disposed in beds pretty regular, a little inclined, 
rising to the north or north-east. 

" The spar which forms these balls, is of 
honey-yellow, or translucid yellowish white; 
and the grain is very {brilliant. The interstices 
of the balls are filled with a less dense matter, 
often cellular and of a coarser tissue, but the 
nature of which is essentially the same. 

*' One cannot bat observe in these forms the 
work of crystallisation ; stalactites and geods are 
seen to present similar structures; but an entire 
mountain, composed of an assemblage of these 
crystallisations, is a most extraordinary pheno- 
alenon."* 

• SauM. § 1478. 



158 »0«IAIK ». ^KOiUkLGff^ 



NOME XDC BARYTTC ROCK. 

Mr. Kirwan informs us, tbat Hoepfner disco- 
vered a whole mountain in Swiseerland, composed 
of quartz, bary tes, and mica partly compounded 
with shorl. Mr« Kirwan calls this kind of ba- 
ryXe^ baraselenite i because it resembles selenite, 
or gypsum crystallised in plates. It is the plane, 
laminar, heavy spar dT Werner, in which the 
most common colours are white aiid red* la 
the curious rock here mentioned, the barytes 
was of a flesh red odour ; but it «nust not be 
for^tten that Hoepfner's observations and ana* 
lyses are not of the first authority ; and his ba- 
ly tes may be fouud to be a felspar. 

In the mineralogy of the department of the 
Loire, there is the following account of a singular 
Fock near Ambierle, a village near three leagues 
N* W. of Roanne*. 

'* There is there seen a rock, situated bextween 
two little valleys, on the eastern side of the hill. 
This rock, which separates these two valleys, is 
a disordered mass, composed of fluor and bary tes, 
sometimes mixed, sometimes in separate and dis- 
tinct parts, but always in intimate contact, and 

* Journal des Miaes, iy. 127, by Passinges. 



HCMIB XUC« BAXYTIC B0CX« 1^ 

traret^ed by some Teins of quartE. The floor is 
of various coloars : green, violet, and reddish } 
yielding much phosphoresceaoe when thrown on 
hot iron, as well as a spathose acid ga&, very acrid 
and corrosive, when it is heated with vitriolic 
acid. The barytes is white, with a slight tinge 
of red, very pure, and disposed in large plates. 
It is sometiiftes crossed with veins of a beautiful 
pitch-stotie, of a deep yellow, a little transpa- 
rent, but sometimes opake, and resembling yel^ 
low resin. 

** The texture of this pitch- stone is rather 
loose, and it seldom strikes fire with steel; btrl 
rn its fracture it shows the conchoidal form, as 
well as the convolved streaks of silex; While 
some, in a state of decomposition, leave a lilac 
coloured earthy which cleaves to the tongue. It 
appears that it is coloured by iron, for there ap* 
pear, in some parts of this stone, grains of that 
melal, which have given more intensity to the 
colour of the pitch-stone in' the adjacent parts. 

** On examining some of the fluors, it may 
be observed that there have been successively de- 
poisfted new layers of the same floor, and of 
quartz of different colours, till the cavity, in 
which the first crystals were formed, ^was filled 
up. This frequeirt mixture of different sub- 
rtances forms veins in zigzag ; because they 64* 



140 DOMAtll nt. AVOMALOVS. 

lowed in their deposition the unequal angles of 
the cubes, which served them as a base. Some 
of these floors ha?e shown indications of the oxyd 
of cobalt, others of manganese in stalagmites. 
Only one piece of floor has been found traversed 
by the same pitch-stone : there are also founds 
but rarely, small cavities which contain little 
crystals of fiuor, bary tes, and quartz. 
^ <' It may be judged by the quantity of frag- 
ments scattered around this rock, and in the surr 
rounding vineyards, that it has been of a far 
greater heigh t^ and that it has been injured and 
shattered from many causes, but especially the 
-cultivation of the neighbouping vineyards ; there 
are even large open slits, which show that it has 
been shaken. 'It has even been attempted to 
make milestones with the barytes, of which 
there are large masses, but the attempt did not 
succeed. AH these fragments display much 
more quartz, mingled with the fluor and barytes, 
than the rock itself; which, nevertheless, may 
be said to form a kind of pudding-stone, as pre* 
sen ting adherent mixtures of various kinds. 

,** The environs of this remarkable hill shoW) 
in the hollow roads, veins of barytes amidst fluor. 
The rocks of the adjacent mountain are of pri- 
mitive grey granite, consisting of felspar, quartz, 
and mica. It is rather soft, but is used for the 



tf 0MB XZ. t AXrINB EOCX9. 141 

supports and traverses of doors and windows; re- . 
sisting the air a considerable time. It is to be 
presumed that mines may be discovered in this 
district, though nothing in that way has been 
attempted. Some cubic pyrites, yellow or black 
on the surface, give no strong hope in that 
respecf 

Some important rocks must now be consider- 
ed, which are not only anomalous in their struc* 
ture, as the preceding ; but of which the whole 
mass forms a deviation from the usual order of 
nature. Such are, as above mentioned, the Sa* 
line, Bituminous, Sulphuric, and Iron Rocks. 



NOME XX. SALINE ROCKS. 

The most remarkable of these exist in Spain 
and Africa. The latter saline hill can only be 
said to have been observed $ but those of Spain 
have been described by Bowles, in his natural 
history of that country^. The first is in Spanish 
^avarre, between Caparoso and the river Ebro, 
in a chain of hills which extend from east to 
west. 

* See the French traoslation, by Viscount Flavigny, Parh 1775. 
Bvo.|». 976,406. 



142 AOMAIN IX. AVOMALOVU 

Of Navarre. ** Thfisc hills," says he, ** are composed of 
limestone mingled with gypsum ; the chain ex-* 
tending more than two leagues. In the most 
elevated pmrt is situated the village of Valtierra^ 
on a slope towaids the middle of which is found 
a mine of rock-salt It may be about 400 paces 
long, and 80 wide. The salt is contained in a 
space of about five feet elevation. 

^^ I exammed/' he adds, << with attention those 
beds of salt ; I compared them with the layers of 
earth and gypsnm in which it is imbedded ; I 
found the cmtside layer to be composed of gyp^ 
snm; aQd immediatdy afterwards I met with 
two inches of white 3alt, succeeded by two inches 
of stony salt and a layer of earth. I found others 
alternately composed of earth and salt, to the 
very bottom of th^ mine, lyhich is of gypsum, 
undulated like the other layers. The layers of 
saline rock are of a dusky blue, those of salt are 
white. 

'• This toine,'* adds Bowles, " is consider- 
ably elevated above the sea 5 for you ascend 
continually all the way from Bayonne." 

The second hill is far more memorable, and is 
even very extraordinary : it is that of Cardona, 
in Catalonia, 16 leagues to the N. W. of Barce- 
lona, and a few leagues from the Pyrenees. 
Of Gardooa. ^* The village of Cardona,'' says h^, ^^ i$ i^itu^ 



ated at the foot of a rock of salt, wluch from the 
side of the rivor Cardonere, seems nearly moiBl. 
This rock is a block of massive salt» which risea 
from the earth about 4 or 500 feet» without ere* 
vices, chasms, or layers: no gypsum is found 
near it. This block is about a iei^e in cir- 
cumference ; and its elevation is equal with that 
of the surrounding moualains s . as its depth is 
not known, it is impossible to say on what it 



^^ In general, the salt from the top to the bot» 
torn is white, though some parts are red ; some 
is also fowid of a fine bloe. 

'^ Thb prodigious flsountain of sait^ destituto 
of all other matter^ is the only one of its kind in 
Europe. I do not know," adds Bowles, '' if it 
would be correct to affirm that it was fonied hjr 
an evaporation of the sea ; such a atdution might 
not satisfy every oue," 

The salt mines of England ase wdU known, 
but are not dtevated above the ground. The 
same obseiration applies to the grand and cde^ 
brated mine of Wielicaka, in that part of the 
farmer kingdom of Pohmd called Galitz, once 
ceded to Austria. Smaller mines of salt are also 
found at Thordi^ Diees, aad Eperies, aU in Hun<* 
gary. 

But the most remarkjUde mines of salt, after 



144 



BOMAlll IX. ▲HOMALOUI. 



OfPenu 



•ocomt. 



those in Spain and Africa, are in Peru; and a» 
thus described by Uiloa, who says they are 
situated at the surprising height of 10 or 12iOOO 
feet, on the grand cham of the Andes. 

« The highest part of Peru/' says UUoa, 
** which seems to be a depot of minerals, has 
also mines of salt. It is found in hard blocks, 
and continuous like the rock. The exterior form 
of this salt strikes at first sight ; for it resembles 
a stone of a dull violet colour, strewed with rays 
of jasper. 

*^ These mines of salt are found nearly all over 
the country; and what is most worthy of re- 
mark, is its extreme hardness, its colour, and 
that it should be in those mountains equally as 
high as those which yield nlver or mercury, 
which is certainly extraordinary.''^ 

Mr. Kirwan has treated this sijibject with bis 
usual mineralogic erudition. 
, ^^ Many mountains, entirely consisttng of salt^ 
have been discovered. The salt mountain of 
Cardona, in Valentia, is from 4 to 500 feM high, 
and about three miles in circumference. Bowles, 
406. Fortis mentions several in Calabria, attend* 
ed with some of gypsum. Several in the States 
of Algiers and Tunis are mentioned by Shaw, p» 



* Mem« i. 3 jS. 



N 



HOME XX« SAfJNB XOCKI. 145 

S99 ; and another in the province of Astrachan, 
3 Bnif. Min. 8vo. p. 371 : the salt in this, how- 
ever^ contains a mixture of foreign ingredients^ 
the nature of which has not been accurately de- 
termined. Th^ salt of the mountain Jibbel .. 
Hadiffa is of a purplish colour, and bitter ; but 
whether the bitterness proceeds from glauber, or 
muriated lime, or magnesia, or some two of 
them, is not known ; but that it proceeds from 
one or other of them is certain, as this bitterness 
is easily mashed out. In the province of Yakp 
outz, in Siberia, near the river Kaptindei, there 
is a mountain of salt 180 feet high, and 120 in 
lem;th ; but at two-thirds of its height it is co- 
vered with a stratum of red clay, which reaches 
to its summit. 1 Gmelin Voy. 342, cited by 
Macquart, 82. 

^* Patrin suspects that many granitic moun- 
tains contain salt ; which, he thinki^, has been 
the cause of destruction of many of them^ and 
at this day promotes the decomposition of many 
that still exist 3 hei^ce he derives the saliniferous, 
sandy plains of Siberia, 4 Nev. Nord. Betr, 167> 
174: but it more commonly, at least, proceeds " 

from salt springs beneath the sand. See 1 Her- 
man Uber die Uralisck Erze Gebirge, 36.^* 

• Kirwan G<ol. Em. 373. For the Salt Mountains of Persia^ 8Cf 
01eariu9. 

VOL. II. t 



I4d mntMn %x^ jiNOKiLori*. 

It ttust not be lorgotten tkat a ttOMMain of 
salt has recently been discovered on the westers 
fide of the rirer Mksourij in North America. 

In the salt mines of England, Pictet observed 
a singular structure, somewhat resembling that 
of basaltic columns. In those of Poland, a simi- 
lar polygonal structure has also been observed^ 
bnt was supposed to arise from lai^ge globalea 
compressed on all sides by others. Further con- 
siderations on rock-salt may be foimd in many 
mmeralogical treatises ; and are scarcely requi- 
site in a work of this nature*. 

BTFOVOMB I* 

Entire saline rock, blue, red, white. 
Micronome 1. Mixed with gypsum. 

* The irnmcroiiaar and prodigious rocks •£ vce in the pekr regtoat^ 
mil^t aind aa intnoiim dttcriplaMi; hut are foragu to 

VQik. 



KOMc XXI. BifruiftiKoua BOCKf. 147 



NOME XXI. BmJMINOUS ROCKS. 

The chief bituminous substances are naphtha^ 
m pn^re rock oil, as fluid and transparent as 
water ; petrel which is less fluid and pure^ when 
it is 3ret more impure it becomes mineral tar. 
Of nmieral pitch there are diree diversities: 
Maltha> of a brownish colour and earthy cont- 
siruction; Asphak» pure and black; and the 
dastic^ or mineral Caoutchou. 

All the bitumena bdong more strictly to the 
province of chemists, who now arrange them 
after the vegetable tmbstances^ from whicli, like 
coal^ they aH seem to be derived. 

They are most commonly found in the proxi>> OtBgnti. 
mity cf that mtneral, and in its moBt wual at* 
leadaat rocks, limestone and sandstone^ Im 
Siberia, bitumen has even been observed in balls 
of ehaleedony. It sometimes also appears ia 
vdas, that traverse that argillaceous gluteoite 
eaUed greuwack; and in veins of calcareous 
spar in basalton, or the transitive grunsteiii of 
Werner. The asphalt occurs in mineral veins^ 
like the eaoutchoo. The chief t^tuminous rock% 
however, are limestone smd sandstone; the fop* 

L2 



148 DOMAIN IX. AH0MAL6U». 

mer being generally black, as at Sefeld, in 
Tyrol. 

The grandest appearance of that nature is at 
Baku, on the western side of the Caspian Sea ; 
whence it is supposed that this substance was 
brought to Constantinople, where it formed the 
chief ingredient of the noted composition called 
the Grecian fire; which, burning with increased 
intensity under water, became a most formida- 
ble instrument against an inimical fleet From 
the description given by Hanway, it would ap- 
pear that the rock is limestone. His account of 
this singular phenomenon deserves to be here 
repeated, 
i^aptiuiof " The earth round this place, for above two 
miles, has this surprising property, that^ by 
taking up two or three inches of the surface, 
and applying a live coal, the part which is so 
. uncovered immediately takes fire, almost before 
the coal touches the earth : the flame makes the 
soil hot, but does not consume it, nor affect 
what is near it with any degree <*f heat. Any 
quantity of this earth carried to another place, 
does not produce this effect. Not long since» 
eight horses were consumed by this fire, being 
under a roof where the surface of the ground was 
turned up, and by some accident took flame. 



irOMB XXI. BITUMINOUS K^CKI. 'l49 

'< If a cane or tube/ even of paper, be set 
about two inches in the ground^ confined and 
close with the earth below, and the top of it 
touched with a live coal> and blown upon, im- 
mediately a flame issues, without hurting either 
the cane or paper, provided the edges be covered 
with claj ; and this method they use for light in 
their houses, which have only the earth for the 
floor : three or four of these lighted canes will 
boil water in a pot, and thus they dres& their 
victuals. The flame may be extinguished in the 
same manner as that of spirits of wine. The 
ground is dry and stony; and the more stony 
any particular part is, the stronger and clearer 
is the flame ; it smells sulphureous, like naptha, 
but not very offensive. 

<^ Lime is burnt to great perfection by means 
of this phenomenon ; the flame communicating 
itself to any distance, where the earth is unco* 
vered to receive it. The stones must be laid on 
one another j and in three days the lime is com- 
pleted* Near this place brimstone is dug, and 
naptha springs are found. 

^< The chief place for the black or dark grey 
naptha, is the small island Wetoy, now uninha- 
bited, except at such times as they take naptha 
from thence. The Persians load it in bulk in 
their wretched vessels^ so that sometimes the sea 



450 BeMiiv IK. AflroMibOtft. 

is centred wkh it fer leagues together^ When 
the weatlier is thick and haary^ the springs boM 
up the higher ; and the na{»tha often takes fire 
on the surface of the earth, and runs in a flame 
into the sea in great quantities, to a distanoe 
idnost iofCreddi^. In clear iveaifaer the spriaga 
dx> not boil up abore two or three £eet ; ia boil- 
ing ^over, this oily substance iMtbes se strong a 
consistency* as by decrees almost to close the 
mouth of liie spring; sometimes it is qnite dosedl^ 
and fonsis lullocks that look as black as piteh^ 
but the spring which is resisted in one piaoe^ 
breaks out in another. Some of the q)nsig8» 
which haipe not been iong opened, £onn a saooth 
of <S or 10 feet dismieter. 

^^ The people carry the napdut, by tranghs^ 
into pits or reserfeirs ; drawing it off from one to 
another* leaving in the first resenmir the water^ 
or the hearier pant widi which it is iniKed when 
it issues from the spring. It is unpfeasant to ihe 
smeU, and used mosfcly amongst the pooser aort 
of the Persians, and other neighbaormg people^ 
as we Use oil in lamps, or to boil their rictnafa^ 
bnt it communicates a disagreeable taste. They 
find it burn best wMi a small mixture of ashes t 
as they find it in great abundance, every £uniiy 
is well supplied. They keep it at a small dts» 
tance from their haiiaes» tuearthea vessels^ under 



• NONB XXI. aiTuicivaya rocks. j^l 

fronad, jb> preMot any accident by fir^, ef which 
it is extremely susceptible. 

'' There is also a white oaptha on tbe peDin- 
^Mlaof Apcheron, of a much (bhtoAer coasistencyt 
but this is Ibund oply in small quantities. The 
fittssiaas drink it both as a cordial and a medi* 
ciaej but it does not intoxicate : if takea tntar^ 
pally^ it is said to be good Sot tbe stone, as also 
&r diaordcKs of the breast, and in venereal cmcs, 
and sore heads ; to both the last the PersktosMe 
yery stti^ject. Externally applied* it is <if great 
use in scorbutic pains, goats, cramps, kc. % but 
it must be ^ut to the part aifected only ; it pene- 
trates iAstaataoeously into the blood, and is apt 
for a short time to create gpeat pain* It has 
also the property of spirits of win^j to take out 
greasy spots in villas or wodlens ; bat tbe remedy 
i^ woKse diaa the disease* for it leaves an abomit 
nable odour. They say it is carried ioto India 
as a gp^9A nurity ; and, bei^g prepaced as a 
japan, is tbe i»ost bewttfut mud lasting of any 
that has yet been found. Not far from hence 
are also springs of hot water, which boil up 
in the same manner as the naptha, and very 
thick, baoig iatpmegnated with a Une day; 
but it soon clarifies. Bathing in this warm 
water is found to strength^i aiid procure a good 



1 

i 



15B BOMAIK IX« ANOMALOUS. 

appetite, especially if a small quantity is also 
drank.*^ 

The justly celebrated Kempfer had visited 
these remarkable springs in the end of the seven- 
teenth century ; and Gmelin, in the eighteenth 
century, 1773, has added little to the account 
of Hanway, except that the soil is a coarse marl, 
mixed with sand, and effervescing with acids. 
There are many other wells in an adjoining pe- 
ninsula ; and the revenue arising from this un« 
common product, to the khan of Baku, was 
computed at forty thousand rubles. 

Werner rather doubts the existence of pure 
and limpid rock oil, and unites naptha with 
petrol: the purer kind indeed seems to occur 
only in small quantities. The mineral tar of 
Colebrook Pale is obtained from a sandstone: 
and Williams has observed many bituminous 
rocks in Scotland. Bituminous shale and marl 
are not uncommon ^ but the whole subject re- 
. quires and deserves further illustration, 

HYPONOME U 

Limestone with naptha, or with petrol. 

^ Hanway's Tnveb, i. S(S3. 



KOKt XZIf. 8UL?HinitC 10CK8. 15^ 



H7PONOMB II. 

Sandstone with mineral tar. 

HTFONOMB III. 

Mumia or asphalt, in the rock, from Persia. 
Micrononte 1. Bituminous shale, 
Mzcnmofne 2. Marl. 
Microfwme 3. Limestone with caoutchou. 



NOMEXXn. SULPHUIUC ROCKS. 

The pyritic rocks^ as has been already ex- 
plained^ are generally arranged in the respective 
modes of the substances in which tliey are found; 
pyrites being, like mica^ of almost universal 
occurrence^ and nowise considered as altering 
even the structure of the stone. 

Werner has considered sulphur as natural, 
and volcanic -, the latter being found in lava, or 
neap volcanoes. That found in the other rocks» 
is here chiefly to be considered : and Mr. Jame- 
son has well illustrated this subject. 



^' Natural sulphur commonly occurs in masses^ 
in gypsum, limestone, and marl. Near Artern, 
it occurs along wifh honey-stone and bituminous 
wood. 

'* It is sometimes found in veins that traverse 
primitive rocks ; in veins of copper pyrites, that 
trayense granite at Schwartzwald in Swab»» in 
Siberia, in the gold mines of Catberineburg, 
and in leadglaace veins in the Altuein flvmn- 
tains. 

*' It occurs also in nests in limeifeQiie, . to Ire- 
land ; in sandstone, at Budoshegy, in Transyl* 
vania; along with ted manganesenM^p at.Kap* 
nik ; and with red orpiment, at Felsobanya. 

'' Very lately, the celebrated and enterprising 
Prassiaa traveller^ Von Humboldt^ communi- 
cated to the National Institute of France, a note, 
ifk wUch he Bieotioas his having disoevened^ in 
4he province of Q«ito, between AJausi and Ttc* 
aa» a bed couponed of s4il|pJKara«idq«ait£^ iaa 
paoHBtaiii «f ouca slat^; aad also goeafcquantitief 
«f wljphqr i« prraitive poi^yry."* 

HYTtmoUM 1. 

t 

Porphyry with sulphur. 

* ** Amnks 'de Museum National, cahier 17-*' Jameson Mia* 
ii. 40. . 



Momm mmm. aov mium» ISS 



HTFONOlfB II. 

Mica slate with the same. 

HTPONOMB III. 

LifflGstone with &u]|)hun 
SandstOM. 



\ 



NOME XXni. IRON HILLS. 



In his curioai work of pfajreioal geegra^y;, 
Becgmaa mforms us that there is a momiUia 
Betr Toniea» in Bothnia, entirely connstiBg of 
ironf-oie. In Luko Lapfamd^ the mountain ^ 
ifirdlivar is one enlare mass of rieh iron-ore, of a 
Uackidi bJae colour, extending like an irregvlar 
i«n £6r more than a mile, sod of a thi d pn cw 
£iMi S to 400 iathoms. He also infecmt ns th«t 
ibe two moantaiitt of Kenmawara and of Lou- 
sowara, in Pitea Lapland, only separated kj a 
mall valley, are entirely composed of inM-ape. 
This iron, as he describes, is called vir^^n or 
native iron; to distinguish it from what were 



156 AOMiLlS IX. AttOUMOJM^ 

called mineralised, as being mixed with sal- 
. phur*. 

This father of modern mineralogy has more 
minutely described the hill of Taberg, in Smo- 
land, in the southern part of Sweden; which 
has been mentioned by Born, as being 400 feet 
in height, and about a league in circuit, in the 
midst of a sandy plain ; and solely consisting of 
granular black iron, cemented by quartz into a 
solid mass, extremely compact and banl. Berg- 
man's descriptipn follows. 
Bergman's ^' Among the most singular mines of iron» 
Taberg. may be reckoned that of Taberg, in Smoland : 
it extends from the N. N. W. to the S. S. E. rising 
gently on the northern side to a considerable 
height ; then sinks a httle, and again rises, form- 
ing at last a very high crest, and terminating in 
an abrupt cliff towards the river Mansarpa, 
above which its summit is elevated 420 feet to 
the S. E. and on the other side of the river is a 
corresponding height ; to the E. and S. W. there 
is a succession of heights, equally separated 
from the mountain of Taberg by a river which 
runs through a valley a quarter of a mile long. 
.Beyond the lake Wetter, in the environs of Jon- 
koping and of Taberg, as far as the district of 

• Journal dej Mines^ No. l6, p. 58, 23. 



NOMB XXIII. IRON HILLS. 157 

Oesbo, the soil is a movable sand. Near the 
cliff are large collections of ferruginous ore; 
tvithout any intermixture of stones ; some being 
several feet thick. They are placed in horizon- 
tal layers, separated by strata of earthy and 
ascend about three-fourths of this part of the 
mountain. The crest of Taberg, and probably 
the whole mountain, is filled with narrow pa- 
rallel veins, which are generally vertical, follow- 
ing the direction of the mountain s the richest 
are seldom more than a quarter of an ell' in 
thickness*^ and are known in that part by the 
name of iron*bands (laernbands): they contain 
a blackish brown and shining ore, which yields 
thirty-two pounds and a half in the hundred 
weight. The common ore has a particular ap- 
pearance: it seems smoked, and has no lustre; 
it gives 31 per cent. That which is called rib- 
bon ore, or pied ore, has layers of white spar 
between its plates, and thus shows in the frac- 
ture alternate rays of white and black ; it yields 
SI per cent. The veins of this latter kind are 
exposed on the western declivity of the moun- 
tain. The effect which this enormous mass of 
ore presents^ is well calculated to excite curib- 

• The Swedish ell is only two feet. 



158 



OOmiN t%, AHOMALOt/^ 



Fitriii*8 
femailtB* 



Blagodat. 



skty and wonder i though it is not the only otautt^ 
pie of the kind thai natitire offers ta ua"* 

Patrin has observed on this description^ that 
Taberg^y fiir from being an irregnlar mass of ore^ 
is on the conlrary a mountain of a most regulat 
strvcture ; the arrects^ or uprightsti having theit 
plaaaes paralkl to its great axis» as is generidlj 
observed in primitive mountains* 

The same aUe observer, who passed many 
years in Siberia, thus proceeds : 

^' The mines of iron in veins, which I observed 
in Siberia, in this Ural mountains, have a singular 
resemblance to* those of Swedeii. 

** The two prmcipat ones are those oi Btego>» 
dat and of Keskanar, both upon the eastern side of 
the UraKam chain ^ the first thirty, and the other 
fifty, leagues to the north of Ekaterinburg. 

** Kagodat, Uke Taberg, is a mountain about 
44)& feet in heigbt^ in which the upright veink 
nm from north to south, as the chaan itself. 

^ The summit; is ahnost entirely composed of 
ore, fi>r an extent of SOO firthoms in length and 



t ThcM isuBg are hatBxded'» at aliead]^ itated, to supply a defect 
in mineralogical langoage* lamented by Saussure and many other 
writers ; the expressions of vertical bedt, or vertical laffers, being 
highly obJ4 



100 ill bfeadth. The Teins, wUch aie several 
feet and even fathons tbick^ are only separafeeA 
hy lajefs of tcbistus^ and a kind of trapi whkh 
are scarcely so thick. 

«< The ore is of the black coinpact kind^ amck 
affected by tbe magnet ; it yields 60 per cent, ia 
fmofiy and affanis most excdlent iron. 

^^ There are annually extracted from thia 
mouDtain two millions of pounds^ or about seven 
kondfed thousand quintals of ore. 

*^ The mountain of Keskanar has a similar Kcdmv. 
stroctare ; it is famous fbr the loadsUMies it has 
produced; blocks of 40 pounds weight of it 
have been found, which woidd carry two hun- 
dred weight; the small loadstones had in pro- 
portion a much ^eater strength; s<Mue have 
been seen which would carry twenty-fife times 
their own weight. This magnet is mixed with a. 
considerable quantity of greenish hornblende^ 
which is dbpersed through it in small nests some 
lines in diameter, and which is very glistening 
when the stone is polished* 

*^ There are also loadstones in th^ mountain 
of Blagodat, and one of its summits is entirely 
composed of theni^ but they hare a singular de* 
feet : when they are detached from the moan* 
tain, their poles mnhiply and intermingle, and 
they become useless. 



IQO OOMAIir IX. AVOMALOUS. 

r 

«< The same summit offers another singularity^ 
which is, that it is crossed by a vein of copper. 
I have brought away a piece of this loadstone^ 
which was found imbedded in this vein, an<i 
which is entirely covered with mountain blue 
and green. Since it has been in my collection 
amongst other loadstones, it has acquired a po- 
larity rather more regular. It seems not impos- 
sible, with some pains, to re-establish that of the 
large pieces, that may be obtained from that 
mountain. 

^^ The Altaian mountains are also in several 
places rich in iron-ore ; but it is not wrought, on 
account of the distance* 

'^' In that part of those mountains which the 
river Irtish crosses, when it quits the lake Zaifs* 
san, I have seen, on the left bank of that river^ 
perpendicular mountains more than six hundred 
feet in height, entirely composed of iron-ore. 
They are of ochre-coloured schistusi the thin 
layers of which are exactly perpendicular, and 
alteriiate with layers of compact iron-ore. 

*' Amongst the immense wrecks of these 
mountains, I saw several pieces of large grained 
loadstone, which contained nothing heterogen- 
ous, and with a complete metallic appearance : 
I brought away some specimens. 

'< It is not only in the frozen regions that 



HOICB XXIII. IKOH HILLi. 1Q|. 

nature has placed veins of iron-^ore; and though 
they are there incomparably more frequent than 
elsewhere, they are nevertheless found in more 
temperate countries. Striking examples are seen 
in the mountain of Etsenertz, in Stiria; and in 
that of Rio, in the island of Elba. 

" The mountain of Eisenertz is 3000 feet per- 
pendicular ; you there find almost every where 
abundance of iron-ore, especially at its summit : 
it is for the most part steel-ore; that is, car- 
bonate of iron, or spathose iron-ore; and it is 
well known that this species of ore is never found 
but in veins/'* 

He then proceeds to state that the mine of 
Rio, in the isle of Elba, celebrated for this metal 
since the time of Virgil,, may be said to be a 
mountain of iron. It now presents only disorder; 
the rock which separated the arrects having been 
decomposed, and seeming now to appear in the 
form of a white bole. 

HTPONOMB I. BNTIEl. 

Iron rock. 

HYPONOMB XI. UUMD. 

With quartz. 

* Pktnn Miiu T. 18. 
VOL. II. M 



a>o)iAiii IX. Mnmkun%. 

Tim subject caimot be quitted without the ob« 
iemtion, that there geenu a most manijfest indi- 
cation of HiHD and DESIGN, oc in other words of 
a great Creator, in the peculiar distribution <^ . 
this metal m die northern parts of Europe ; when 
He knew, to whom all times are present, that it 



not seem to have been made, namely, the superiot 
size and strength of the female, when compared 
mth the male, solely among the birds of prey; as 
it was necessary that she should both protect and 
feed her voracious offspring. 



DOMAIN X. 

TRANSIUENT. 



XHiS diirisioa induces the rocks vhich iNftinct 
■wMcnly pais irom one to another, so that 
apedmenakuay aooMtimes eTeo appear in 
caUiiets ; while th99kansitive rdeks com- 
nonly occor in a slow 'and scarcely visible 
pngress ; die term implying, in Werner's 
system, those intermediate between th« 
ftiiiiitiTe and Secondary. The sadd«mc<» 



1^ DOMAIN X* TIANSILIBMT. 

of the transition has given rise to the deno- 
mination, which implies that the substance 
has leaped, as it were, from one to an- 
other. 

These rocks are extremely interesting in 
the study of Geology; and the learned 
reader will observe, that this treatise fdrms 
a ^adual introduction to that sublime 
science, or rntiber study; for,, even in the 
German sense of Geognosy, or knowledge 
of the shell of the earth, it can scarcely 
ever be supposed to arrive at the perfection 
of a science. - '- * ^' ' 

Db^ct from Great care must be exerte,d not to con- 

AducreBt. ^ 

found the rocks which are merely adherent, 
or composite, with -tlK>se that really gra- 
duate into another. Saussure, in speaking 
of a Emssian tfareildr, J!fays,;;that 2ie woolc 
have boldly asserted ithat a iroasting.igooeai 
graduates into the spit Thu3 someitJieo^ 
nats have coriceivied that lime ;becQiDQBi 
^t, 0r flint graduates into lime, from.thoi 
iperq .ipi^ture of the particles neai;the line^ 
qf jthgir junction. The most pfop^ an^^ 
Hn^oubtM graduations occur pnly amoo0L 



DOMAIN X. TRANSItlBNT. • ]55 

the kindred rocks ; and are generally a 
mere variation of the Mode or Structure ; 
as the passage from granite to gneiss, or 
from granite to granitic porphyry. If the 
granite be surcharged with siderite, and its 
particles become very small, it may pass . 
into the real basalt of the ancients; but 
can never become a basaltin interspersed 
with chrysolite or zeohte ; and if the ba- 
saltin occur with granite, it must be merely 
adherent. Keralite may, by imbibing iron 
from the atmospheric air, or whatever 
cause, become jasper. Werner has ob* 
served, that wacken passes into clay on one 
hand, and basaltin on the other; which 
last again passes into basalton or grunstein. 
Many other undoubted transitions may be 
observed ; but it will suffice to enumerate 
some of the most remarkable, leaving the 
others to time and accurate observation. 



]66 / ^OMAIV Z« TRAHULXXNX« 



NOME I. SIDERITE AND BASALT * 

This transition may be observed in the Egyp- 
tian monuments, and is not uncommon in nature, 
when, in the German language, the massive 
hornblende rock passes into grunstein ; or, in 
other words, becomes interspersed with small 
crystals of felspar; the common basalt of the 
ancients. 

Siderite with basalt, from Egypt 

The same, from Mount Sinai. 

The same, from the Alps. 



NOME n. BASALTIN AND BASALT, OR 

BASALTON. 

That is, in the German dialect. Basalt pass- 
ing into Grunstein. Daubuisson observed this 
Of Meisner. transition, in great perfection, at Mount Meis- 
ner, in Hessia, which rises like a colossus above 
the other heights of that country. f The mass is 
of shelly limestone; towards the top there are 

* The vague words toith or and are used, because it cannot be 
poutively afiirined which graduates into the other. 
t Sur ies basaltes de la Saxe, p. 59. 



VOM£ II. BASALTIN AlTD BASALT^ OK BA8 ALTON. \Qj 

thin layers of sandstone and sand^ followed by a 
bed of coal, in some places not less than 28 
yards in thickness. Immediately upon this coal 
reposes a platform of basaltin, forming the level 
on the summit, which is about nine mifes in 
length. and about three broad. The basaltin 
exceeds a hundred yards in thickness. 

** The grunstein appears almost every where 
above the basalt, and in some places has the ap* 
pearance of a beautiful granite ; the grains of 
siderite being black or green, laminar, and bb 
large as peas, while those of felspar are whitish. 
On the lower part of the platform, towards the 
west, there is a basalt in prisms ; the most black, 
the most compact, and the most homogenous, as 
far as can be judged, that can well be observed. 
I here arranged the sequence of a dozen speci* 
mens, which presented a decrescent progression, 
with regard to the size of the grain> from the 
beautiful grunstein to the compact *foasalt, of 
which I have spoken ; and to shun the objection 
that the specimens did not belong to the same 
continuous mass, I chose some in which the 
small grained grunstein was in the midst of the'' 
compact basalt; and they might be seen, so to 
speak, melting into each other.'' He then 
quotes the remarkable passage of Dolomieu in Ancient basalt, 
these terms : ** I have seen many statues, mor* 



108 DOMAIN X. TRAKSILIEMT* 

tai^, sarcophages, made of black stones, which 
have all the characters attributed to the ancient 
basalts, and which have preserved that name ; and 
I can say, with positive certainty, that none of 
them is volcanic." Dolomieu then proceeds to 
state that some of them are siderite, or massive 
hornblende ; but the most compion are a kind of 
granite, in which the siderite so predominates 
that the mass appears black, though it be asso- 
ciated with a white felspar, of which the grains 
are so small, or so interlaced with the scales of 
siderite, that it is difficult to discern them ; espe* 
cially as the felspar itself sometimes appears 
black, because it is transparent. He adds that 
it happens sometimes that a greater quantity of 
felspar imparts to the rock the appearance of a 
real granite ; that is, as Daubuisson observes, a 
real grunstein. 

This passage of Basaltin into the real Basalt 
of the ancients, is one of the most remarkable in 
Geology; and particularly interesting to the 
accurate and scientific observer. It seems, how- 
ever, to be somewhat surprising that, while these 
substances are often found to coalesce, the 
Egyptians did not prefer the close grained and 
uniform basaltin to their coarser basalt. Siderite 
is also found in Mount Sinai, and pe/haps in the 
eastern chain between Egypt and the Red Sea } 



VOMB ni. BAIALTIK WITH POBPHTBT. 169 

bat as the ancient authors are unanimous that 
the basalt came from Abyssinia, it probably oc« 
curred under the appearance of columns, of too 
small a diameter to be employed in arebitecture 
or monuments. It is to be regretted that the 
mountains of Abyssinia have not been explored 
by any geologist, as the transcendent beauty of 
the emerald-green granite alone might invite a 
research into that interesting region. 



NOME in. BASALTIN WITH PORPHYRY. 

Basaltin being the base of porphyry, it is na* 
tural to eipect many examples of this kind. 
Among others, near the village of Renaisoii, in 
the department of the Loire, there occur, after 
passing through fragments of granite, rocks of 
black trap, surmounted by porphyry of the same 
base, the transilience being clear and palpable. 
This porphyry is crowned by another porphyry, 
of a brownish grey ; but in this the crystals of 
felspar are long, and thinly scattered (a por- 
phyron); while the others are white, and fre* 
quent. The black porphyry, and even the grey, 
are harder than the tr^p. 

The separation of the trap or basaltin from 
the porphyry is clearly marked by an undulat- 



170 



AOMAIIf X. TRAN8IX.IBVT. 



ing line, in a fragment which has been polished. 
The porphyry has taken a fine polish^ while the 
basal tin remains dull. The polish of the por« 
phyry has brought to light little crystals c( 
schorl, or siderite, which could scarcely be dis* 
covered in the rade fragments.* 



NOME IV. BASALTIN AND WACKEN. 

* 
t 

This transition has also been accurately traced 

by Werner himself. Speaking of the mountain 

weniei^ of Scheibcnberg, he says, " I have seen there, 

account* , , 

in a successive series of shades, the most perfect 
transition from clay to wacken, and from this to 
basalt. (basaltin) : these three substances are the 
produce of the same formation ; that is to say, 
they are precipitates or sediments of the same 
dissolution, which becoming more and more 
quiet, has deposited the clay, then the wacken, 
and lastly the basalt."f This explanation de- 
pends upon Werner's theory, that the rocks 
. were deposited by waters in different states of agi- 
tation or of tranquillity. It may be added, that 
there is much heat, or, in strict terms, caloric, in 
water itself, which would otherwise be in a state 

* Jonrn. dci Mines^ iv. 133. f Daub. Basaltes^ 58. 



XOM& Xr« BAtALTlK AMD IfAOKBN. « lij"] 

of ^> not to mention the heat developed by 
crystallisation ; so that the agency of heat may 
be conceived as admitted even by the Nep- 
tonists* \ 

-: On the transition between Basaltin and Wac- 
ken, the remarks of Daubuisson may also be ' 
adduced. ** We have already observed that ba^ 
salt has great connexions with the argillaceous 
rock called wacken. Let us recollect those 
prisms, of which one of the extremities is a true 
basalt, while the other is an argillaceous sub- 
stance, both being the evident produce of one 
effort; Na circumstance which excludes every 
suspicion of a volcanic origin. This argillaceous Basaitunot 
wacken cannot be considered as arising from 
an eruption of mud ; for between it and the ba- 
salt there is a most marked transition, there not 
existing even a line between them. Nor can it 
be said that this wacken is a decomposed lava ; 
for at Scheibenberg, for example, the wacken 
passes to common clay, which degenerates into 
sand, and then into gravel; but a lava, when de- 
composed, does not produce gravel of quartz."* 
He adds in a note, that olivine, augite, &c. 
though common in the basalt, are not found in 
the wacken ; so that the latter cannot be a de« 

• 

• Daub. Basaltes, 73. 



1 



m 



DOMAIN X. TIAVftlLinrT* 



composition of the former. It must however in 
candour be added, that after hiis visit to Auvergne^ 
where he was unexpectedly con vincied of the voi* 
canic nature of the products of that country^ 
Daubuisson hesitated concerning even the ba- 
salts of Saxony, and hinled to the author that 
they might be volcanic, but, as resting on the 
summits of hilb, of an antiquity altogether in-> 
conceivable. 



NOME V. WACKEN AND CLAY. 
This transition has been before described. 



NOME VI. JASPER AND KERALITE. 

This transition, according to Patrin^ is com- 
mon in Siberia. The author has seen specimens^ 
in the collection of that celebrated traveller, of 
keralite translucent on the edge, joined with 
opake jasper. The colours also correspond; 
but in the keralite they are pale. This transi- 
tion seems to depend on the greater or smaller 
quantity of iron, a chief constituent in jasper. 

* See his papers in the Journal de Physique ; and here Dom. I. 
Mode Basaltin. 



vents Til. Awn ▼in. tiS 



mrpoNoiiB I. 



Massive. 



'^ 



HYPONOMS II. 



Schistoa^*. 



MOliEyn. SLATE AND CHLOHrTB 

This is rather a scarce transition^ the latter 
substance not being common. Slate also passes 
Ihto mica slate; and sometimes into the massive 

9 

substance described under the Mode Slate. 



NOME VIU. FELSITE AND BASALTIN. 

' Dolomieu, in his able memoir on petrosilex or 
felsite, trap, and roche de come, or magnesian 
basaltin, observes that they are the chief bases of 
layas^ and thus entered into his consideration^ 
in. forming a system of volcanic productions. 
He then speaks of the various transitions of his 
petrosilex 6r'fehite*. 

I • * Jovmii dk^Phyw^itf, new seriet, ? ol. i. p. i950. 



/ t 



^4 BOIMUrvX. n4^Nm4tNT. 

*' Petrosilexy as I have already said^ unites 
itself by gradual shf^de^ with all rocks> in whose 
composition some of the free earths enter^ or 
compound particles which may assist in the 
formation of the masses which it chiefly consti* 
tutes. Combined with pure quartz, in which it 
seems to dissolve, it gradually assumes all the 
characters of quartzose rocks ; by a progressive 
augmentation of talcous earth, it proceeds to 
unitd itself to fitefttitts and serpentines, forming 
in its progress a kind of fusible jad, which has 
not the weight of common jad: it acquires the 
earthy smell, as it approaches the roche de come; 
the schistose tissue, in uniting with argillaceous 
schisti. But it is when it approximates traps, 
that the shades of its transitions are most insen- 
sible : and an infinity of rocks placed between 
the two, leave the greater uncertainty concern- 
ing the species in which they should be classed, 
as the composition is scarcely ever the same in 
all the parts of the same mass : one portion shall 
incline to trap, while the other is affected by the 
fire like petrosilex. The base of many porpby-. 
ries is found in this intermediate situation; aa 
well as most of the ancient grey and green ba- 
salts which come from Egypt, when it happens 
that the fineness of their paste no longer allows 



the distinct grains of felspar and greenish horn- 
blende to be perceived^ v^hich are still visible in 
the greater number/* 



NOME IX. GRANITE AND BASALT. 

This sometimes occurs in t^e Egyptian mo^ 
numents. In Norvray^ and other primitive 
countries^ veins of basaltin occur in granite] 
but it is a mere coherence^ and there is not the 
smallest trace of transition. , 



NOME X. GRANITE WITH GNEISS. 

This transition is one of the most common in 
primitive countries. 

Red granite with red gneiss, from the Alps. 

Grey granite with grey gneiss, from th« 
same. 



]*J'5 BOMAIN X. TRAM8ILIBMT. 



NOME XL QRANITE AND GRANITIC POR- 
PHYRY. 

This is also a very common rock. 

The passage from granite to granitic porphyry 
being one of the most remarkable and important^ 
the following observations of Dolomieu will be 
found to merit particular attention*. 

** During the great coagulation, to which the 
primitive mountains pwe their construction, it 
seems that there have been substances, of which 
the concurrence, or too great abundance, has 
impeded or prevented the regular aggregation, 
in giving the paste a tenacity, in some manner 
fattening it, to make use of a term applied to 
mother-waters when they refuse to crystallise. 
Such are the particles of talc, and of argillaceous 
And magnesian earths when free. It seems that 
these earths, naturally unctuous, have prev^ntied 
the other particles from assuming the places to 
which the laws of elective aggregation destined 
them, in causing them to slide on one another. 
I have pretty generally observed that the super- 
abundance of magnesian earth chiefly acted upon 

* Journal de Physique, new series, vol. i. 1794, p. 193. 



von XI. ^UWIJ* ♦¥!> .tB4«TIC f OBPHYIT. l^fj 

ijti^ bmiofur teoUvr^ of fd^r, C9m\ng iu lm$ 
without depriving the feUpv of the £»^ulty of 
MMifBing the exterior fomi of it8 wual crystal- 
lisation. This i» peroeiYed in itbo^e felsptry^ 
arhicfa comtitute the large >pot« io green por^ 
phyry» called serpentino a»HcQ i and 3till moro in 
Ibd fidapaj^t which ipiogled with green hom«* 
blende fiirm die granites called Egyptian greens. 
It finequently happens that their oompact fra^ 
(lire no longer presents any indicatiim 6f a lami- 
nar teature^ though they still affect the quadraor 
gular prismatic ianxif whkh beloogs to their 
mode of crystallisation. 

^^ Just as in the magma of mother* watm» ire*- 
ducedto a state of paste bv evaporation^ tbere 
one partides whichy escaping from the viscidity 
of tke meoHum in which they are engaged, agr 
gregate and form crystaIs^ which are found hi)** 
ried in the mass: in the same maaoerj io these 
kinds of m^ma of die gieat precipitation^ it if 
rare that some isolated crystals are not f(mnd 
among them ; and which hiive acquired so mncb 
mem bulk apd regiilarityj as they have had 
mom facility of i^ggregation. They a» diatia^ 
guished from the paste which contains them» by 
their form, their tissue, and almost always by 
their colours^ brighter than that of the base. 
Thus are formed rocks called porphyries j and 

VOL II. Ti 



which, in reality, only differ from graiutes by 
this accident of aggregation*. 

^^ The' distinction eslablished between grankes 
and porphyries is proper* for common use, it is 
necessary for artists ; neverthele^ the lithologiat 
could not admit it in' a strict sense, Witfaoiit exf 
posing himself to an error, which might lead hiui 
Onuiitet. to mistake the identity of the origin of these two 
rocks, and the analogy of their compqsitioo. 
The celebrated naturalist (M. de Sausenire), who 
has furpished us with a gr^at and important 
truth, by proving, by a thousand exceUi^nt oh* 
servatioDs, that the parts' of granite are canton^ 
poraryy that they have all bem farmed in the same 
element, and by the same cause, and that the prin* 
eiple of this formation is crystallisation ^ but who 
has thought he ought to make two separate 
genera of granites and porphyries, and who tQ 
distinguish them, has said, in granite ikerei is no 
paste, which envelops the stor^- grains of which it 
is composed, while in porphyries, is seen a wliifam 
iascyor cement, in which the other \stones are eii* 
closed : this naturalist, I say, by the progress 
«f his researches, has soon himself found the in« 

ifufficiency of these distinguishing characters, of 

» ■ » » 

* This can only apply to granitic porphyries: end some other 
Rnuirks must be paidonedj^ from the state of the science at that 
periodi 



MOiCB XI. OAAVITB AlTD OHANITIC POSFHTIT. 179 



which I have long combated the precision, 
mitive mountains have often shown him^ as well 
as myself^ many rocks which have united the two 
modes of beings and which seemed to be inter* 
mediate species between real granites and real 
porphyries ; and to point out the gradations by 
which nature passes from the formation of the 
one to the other. How many rocks have I not 
observed, which, by their polished sur£su:es» 
showed the texture attributed to porphyries, by 
distinct and isolated crystals, forming spots on a 
base apparently compact, and of a dijQTerent co- 
lour ; while their fracture represented grains of 
granite, by the scaly tissue of the substance 
which had appeared to be the paste, in which 
the other substances were enveloped ; for granites 
have a granular appearance, not always by the 
detachment of the grains of each of the sub- 
stances which compose them, but by the nature 
of the texture of the felspar, of which the plates 
cross each other when confusedly crystallised* : 
and in all compound rocks, the substance which 

* *' It is equally on aocount of tbdr acaly tissoe that spany 
marbles^ called taline, aeem fbnned of large grains^ adheriog toge* 
ditr by jtDLtapoaition. They owe the appearanoe of it to a eonfused 
aystalliaation^ which interlaces the spany plates $ and they lose this 
granular aspect, to assume that of a compact and uniform mass^ 
when they axe deprived of this commencement of regular aggre* 
ptioB.** 



1^ OQHAIW :(• T|tAMSI|.IBNT. 



i$ 5{ifficjdotIy ^undtot not; to be divided by file 
fencounter of other small stones mixed wHb it» 
aud for its parts to form a kind of coptioviity of 
o^asSf in surronQdiQg th^ other substanoes^ of 
tvbich the graios are easily isolated> loay be coor 
sidered u the principal base of the rocjc^ or af 
thi^ cement which agglutinates the raiaU stotij 
bodiesj of a different nature, QoncurdAg tp ti» 
foroiation of the mass. Such s^re granites^ when* 
f!^par alooe often constitutes diree-fonrtbii^ 
sonaetimes ibur*fifths of the mass ; «od if an j^bs^ 
traction of the sparry tissue is allowed, which 
depends on a rather «ore perfiscfc aggr^^tioo^ 
and of which it aiay be deprived without change 
in$ its nature^ the granular appeaiance of the 
granite disappears, the Cetlspar assumes the aspect 
(^a umtnt in wkieh the other stones are enclosed^ 
and the rock acquires the conformation of por* 
phyry» without the transition of the one to th# 
other requiring any oth^ condition. Nature 
often, as if she would demonstmte the idmitity of 
thje two rocks, perfonns heiBelf, in certoin masses, 
this successive transformation of granite to por* 
pbyry, by taking away and returning at inter^ 
yals its laminar tissue to the feli^par $ and she 
produces masses which, according to the ex- 
pression of definitions, may be in part placed 
among granites^ in part among the genus of por- 



VOHt XI. •lAirm AMD OBANlttO POIFMTHT. ISl 

]bh jries. It is not even requisite thtt the felspar 
shduld entirely fose its texture; it Is sufficient 
that it be in very small platek confusedly inteiv 
mingled, and that it contains other crystals of 
the same nature, but larger and better marked, 
and a litde distinct by their colour from the buM 
in which they are contained. Thus there ig 
often observed among the Egyptian monuments^ 
at Rome, a rock whose base is a mixture of feld- 
spar and black hornblende, both in small grains^ 
although still msry apparent; in this kind of 
granitose paste are contained tolerably regulai^ 
large crystals of white or red felspar, which forml 
spots on the base of the rock, and which give it 
the greater appearance of a porphyry : as some* 
times the abundance of hornblende renders the 
paste which contains these crystals almost en^ 
tirely black*. The granites called the green of 
Egypt, composed c^ hornblende and felspar^ 
become similar to a porphyiy, if the proportioa 
of hornblende ever so little exceeds iSiat of the 
felspar ; because then the crystals of the latter 
detach themselves from one another, and, by 
separating, form distinct white spots on the dull 
green base of the took. The uncertainty of the 

* Dolomieu by no maans exeeb in Utecaiy oompoiation, hit cea« 
ttnpet being very tfedious and complex. His long notes, which otdj 
distnct the attention, are here thnMvn into the tezL 



182 DQiumx* TAAvstLixmr. 

charttcters of this rock has always embarrassed- 
systeittatic noikienclators, they have varied in the 
name they have bestowed on it, and in the 
place they have assigned it. 

/^ I have seen in the mountains of Tyrol, 
and especially in the large rolled pebbles in the 
plains of Verona, which have descended from 
them, a great quantity of those rocks which 
might be called porphido*granites, from the 
imibn of those two characters; but the most 
curious of this kind I have ever met with, are 
those of Corsica ; of which, ten years since, I 
deposited a hundred specimens in the beautiful 
cabinet of Florence, under the direction of my 
illustrious friend Fontana. 

^' But it is not the granite of the earliest pre- 
cipitation which possesses this identity of com- 
position with porphyries; these primary granites^ 
as I have said, are more quartzy than the others; 
the felspar is less abundant in them, and cannot 
represent a cement The medium in which 
they were formed being purer than in later 
times, the particles differently constituted have 
been less interrupted in the choice of places, 
assigned them by the aggregative attraction; 
and if in a few of these granites some of those 
large spots are found, which, like placards, an- 
nounce some change in the constitution of the 



iroMK XI. OBAinra avd ORAirmc porfhtrt. 183^ 

rook» they are formed, by kinds of knots, oi^ 
large kemds of a globular figure; the sab* 
stances appear, «8 it were, nodular, and disposed 
in concentric layers ; it seems that they might 
be produced by a small whirling motion in the 
fluid where the rock has coagulated*; and they 
resemble those knots which are seen in alabaster, 
and other rocks produced by concretions, when 
the water which deposited them was agitated^ 
Posterior granites are most often deprived of 
grains of pure quarts^ or display smaller, and in 
less quantity. The argil predominates more ia 
the whole mass ; and the felspar does not appear 
in it of exactly the same nature, since it admits 
'a larger portion of calcareous earth, which per- 
haps is not at all essential to the composition of 
the firstft 

^^ More than three*fourths of the antique gran 
nites of the monuments of Rome, are deprived 
of grains <tf quartz; among others, the beautiful 
reddish granite called Sosato, of which such im* 
mense columns and so many Egyptian monu*^ 
ments have been formed ; and in which I have 
discovered a considerable number of small octae- 
dral crystals of opake yellow jacinth. Often in 
these granites, mishapen crystals, or grains of 

* Owing perhaps to ps^^ 



li)4 



saMxiir xi TUiun.iiiiT« 



trangjiaretit kUpvti are mistafcen for qoaitz, hi« 
astench as there is one directioti in which their 
vitreons fracture is exactly like that of quarts ; 
but their fuiibiiity easily distinguishes them^ 
when brought to the proof of the Uow^^pipe. 
perphyries. ^* By the infcrse of what we have said, ibt 
best characterised porphyries easily pass to the 
state of granite. It is enough that their base 
shows a beginning of regular aggregation ; and 
there are fek large masses of red porphyry amon^ 
the most perfect, in which spots ape not observedi 
often more than a foot in extent, where the graina 
of felspar multiply sb as to touch each other } 
little cryi9tals of black schorl are then seen in the 
midst of theih, which hate also profited by the 
local facility giveh to tlie aggregation, or whicH 
perhaps has caused it by seizing the irdn ; th^ 
presence of whibh^ when it is free and oxyginated, 
iohr BAto assume ihfe red colour, seems io place 
An bbstatle to the crystallisattotl* Thus also ah> 
th^e partfe of granitic appieafance discolouifid : 
one would of%eil bditeTe that those large grey 
granitose spots^ which disfigiire the purple co^ 
lour of the rock, proceeded froni foreign miti* 
stances accidentally incorpoiuted in the pastb of 
the porphyry ; if one did not discern on th« 
margin of those spots, thaf the grains become 
gradually less distinct, and reassume the tissue 



mourn xu etaiiin amd opAinTio fOB?BTRT« 1^5 

of the hmkf in which there is some appeanace 
€fi m solQtkm of coiitiitiiitgr« 

^< There are (KMphjnies in Which these spots^ 
which diffisr by their coloiif and texture from 
l^e base of the iock> are so multiplied that they 
resemble bricias^ and ieoeive from them the epi* 
thet of Porjidi briciatu They appear formed of 
an infinity of similar fiieoes, which beconke 
united by a common cement. This kind of por« 
phyry seems to me to depend oil sdme accidents, 
which have disturbed the coagulation ; Which 
has been suspended and resumed at several 
timeti 

^^ I mention^ with equal confidence^ the im- ifoimneiitiof 

Rome* 

mcnse blocks of rocks of diflferent natares» which 
decorate the city of Roioae) or are found in its 
rninst as I would mention the mountains them«* 
selves from which these neks have been extract^- 
ed ; because ii is seldom that nature herself ex* 
poses masses so large, and in such perfect pre- 
aem&tion ; and to obtidn them thus, it has been 
neocssary to attack the heart itself of the moun- 
tains. Columns of granite from 40 jto 50 feet in 
elevation, sarcophages hollowed in n^ses of 
j^rphyry to the extent of even 1000 cubic feet^ 
present as much matter fw observation as the face 
offa rock naturally exposed; and they show the 
substances in a state ef preservatiOi» which they 



]gg OOUAtfr X. TBAmiLISKT. 

cannot hare on the sur&ce of inountidBS,' whereir 
the weather, and a thousand other causes of de^. 
gradation^ alter the hardest rocks. If I have 
acquired some knowledge of the nature of rocks> 
I owe it in a great naeasure to the comparisons 
that I have been able to make from the observa- 
tions furnished by the monuments of Rome, 
with those which I collected in the mountains : 
and I cannot too much advise all naturalists^ 
who travel in Italy, to pursue a regular course 
of lithology on those large masses, whose ex- 
traction is a proof of the industry and power of 
that ancient people who used them, and of which 
the beauty seems to assure a sort of pre-eminence 
to the eastern regions which furnished them-: 
and this advantage which they possess over ours, 
is doubtless owing only to the scantiness of 
means that we have employed to find similar 
substances in our own mountains; thus how 
ridiculous our magnificence appears, when we 
compare it with that of the ancients 1 I have, 
made a descriptive catalogue of all the monu*: 
mental rocks of ancient Rome, which perhaps 
may not be uninteresting. 

^< It is besides easy to show that the bases, of 
many porphyries are only disguised granites; 
and it is sufficient to take off the kind of mask* 
which, covers them, and which depends on the. 



ttOMB ZX. OBAHTTB AND OBAMITtC POBPfitBY. 

colouring substeilce^ to behold with astonish* 
ment that this base judged to be uniform, is itself 
a stone composed of two distinct substances^' 
which do not even always require the powep of 
the lens to be observable. Taking, for example,; 
a small piece of the base of antique red* pdr«- 
phyry, and with a blow-pipe directing the flame 
of a taper on it, it becomes brown by the first 
Mast of the fire ; and then are easily perceived 
the small black and white grains, intermingled 
like those of granite ; and continuing the heat 
io the fusion of the mass, the white semi-trans- 
parent frothy vitrification of the white grains in« 
dicates the felspar : the opake black glass pro- 
duced by the others, announces the schorl ; this, 
more fusible, melts the first, and often encloses 
small grains of felspar, before the fire has af* 
fected them, and then their glasses mingle. As 
to the proportion of the two substances, it dif- 
fers ; but although I have observed them alter* 
nately to take the predominance, the one over, 
the other, in the different masses that I have 
essayed, I have nevertheless found that it wad 
the felspar which most often predominated in the 
base of antique red porphyry/' 

He proceeds to observe, that what he calls 
the ancient green serpentine, from the Italian 
phraseology, and which is our green porphyry. 



1«7 



18S 



DOMAIN Z. TmAlUIllBMT. 

pM»ient8 in its baae a superabundance of what lio 
calls schorl ; that is, the hornblende of the Ger« 
mans^ or siderite of the present work. In sMae 
porphyriesi called by the Roman artists Ubria^ 
genes, the felspar appears, as it wejre, melted 
into the base, so as only to ptes&at spots of a 
different tint. It is now well kbown that the 
base of the porphyries is a trap, or basaltin ; and 
Dolomieu has the merit of having perhaps first 
observed that it could not be a jasper, as it is 
ei^sily fusible by the blow-^pipes but many 6f 
his observations will, in the present advanced 
state of the science, be pronounced to be in«* 
accurate. 

Grahite ^nd granitic porphyry, firom Mounk 
Sinai. 

The same, from the Alps. 

The same, from the Grampian mountains, in 
Scotland. 

In general the Scotish grianites are very ine- 
gular 'y and, in small fragments, often appear as 
granitels, consisting chiefly of felspar with littlitf 
seams or particles of mica, while the quarfes is 
often rare and distant. 



HOMM XXV AMD Zllli JQ^ 



NOME XII. GNEISS AND MICA SLATE. 



is also 9i commoQ transition in primitiv« 
countries. 

Goeiss and mica slate, fr<Hn the ^ps, &c. 



NOME Xni. STEATITE AND ASBESTOS. 

. Steatite, in assuming ^ fibrmis form, passes 
into asbestos. This traqsition is very uncom- 
mon. Saussure has described a rock of this 
kind 3 and Patrin hfis iobserved that it affords a 
remarkable example of the passage of one n>ck 
into another. 

^^ This stoi^e, which I maeived foam M. Stmvei 
is of a grey colour, sometimes inclining to yel* 
loir, sometimes to green. It greatly resembles 
asbestos; but the filaments are larger, softer, 
and more nnctuons to the touch ; whHe the 
fracture lengthwise presents long and large 
fibrra, parallel among themselves, perpendicular 
to their bases, and irregularly prismatic. Some 
are straight, others a little bent ; and they am 
sometimes three inches in length. Their lustre 
is little or none i and where it seems lively, and 



190 lyOUktS X* TEAN8ILIEKT* 

t 

almost metallic, this effect is produced by a thin 
coating of talc, which covers the fibres of the 
stone. .... 

^^ The cross fracture is extremely unequal and 
tplintry, with a mixture of spangles of a differ- 
ent substance. This stone is translucent oq the 
edges/ to th6 thickness of four tines, and so soft 
as to be scratched with the nail, the streak being 
whitish and of some lustre ; it faintly stains cloth 
with a grey line^ is 9, little flexible, and pretty 
heavy. Under the blow-pipe it melts into a black 
globule, not exceeding the tenth part of a line. 

^^ It is then evidently an interinediate kind be* 
tween talc, steatite, and asbestos. . 

^^ The long fibres; are intermingled with pris^ 
matj^c columR3» strjated lengthwise, white, la* 
minar, very brilliant, but of which I do not 
know the nature. . . They are soft, translucent, 
and soluble ia . nitrous acid ; but without offer* 
vescence, and in lengldi of time. Th^ do not 
crackle under the blow-pipe ; and oh charcoal 
turn brown without melting. They can only 
be melted on a point of sappare, into brown 
brilliant glass, without bubbles, and half trans- 
parent y the drop not.exceeding the tenth part of 
a line. This stone is found at Weysler Stoude/'^ 

♦ Sauss. 1915. 



VOUM XIT. •BALS AKO OOAI,. Igl 



NOME XIV. SHALE AND COAL. 

The particles of shale sometimes pass into 
coal J or the reverse. Bat this may rather be 
regarded as an adherence. Sometimes the shale 
is marked with vegetable impressions^ which like- 
wise pass into the .coal. 

Coal is sometimes, however, found so impure 
as to be unfit for domestic purposes ; and such 
mines are commonly abandoned. When in the 
mineralogic language it passes into sl^te, it is 
far from being a recommciiidation in the kitchen 
br in the parlour. 

The passage of coal into bituminous shale, is 
the most interesting. The latter sometimes . 
bears the impressions of fish ; which never seem impitMioitt. 
to be observable on the coal. But Mr. Jameson 
says that the fish themselves are generally con- 
verted into coal, sometimes the scales into cop* 
per-ore; bituminous shale being common in 
copper-mines. It is the slate-clay, Schieferthon 
of Werner, which generally accompanies coal, 
and presents vegetable impressions, chiefly of 
gigantic ferns and reeds now only found between 
the tropics. This substance is commonly soft i 
but is sometimes so bud as to resemble basanite. 



102 DOlUUr X* TllAVfII.I«Nr« 

The clay-slate of that author^ thanschie/er^ is 
our date^ simply so called by way of eminence, 
but a graad and priwitiva rock ; while the other 
is understood to be of recent formation. 

BTfDNOMS 1. 

Uniform. 

HTFONOMS II. 

With impressions. 



F " ^ 



The following transitions are upon a larger 
and more various scale ; but may be here sub- 
jQin^> in order to thrpw more ample illustration 
upon a curious and intricate topic, 

Saussure has minutely described a singular 
transition from graijiite to limeslate^ which he 
observed not far from Courmayeur*> 

*^ Travelling through these pasturages^ the 
eyes always fixed on the prijnitive chain> I sai/f 
below this chain beds similsur to slates> and lean- 
ing against rocks of granite. As nothing in my 
mind is more interesting for theoryt than the 
junction of mountains of different orders» I de- 
termined to examine this ; but as it was too late^ 

» { S7t. 



VA1I0U8. 153. 

in the day, I went to sleep at Coumiayeary dis* 
tant from it two leagues^ and returned on the 
morrow. 

** Quitting the .bottom of the valley, you must. ' 4 
ascend for nearly three quarters of an hour, to. 
arrive where the schisti touch the granite. These 
schisti, which at.a distance only appeared a thin 
surface, adhering against the foot of the moun- 
tain, fire 9 considerable mass, of different layers. 
The substance which composes the greater part 
of these layers is remarkabld^ in that it briskly 
effervesces with acids, and yet very easily ilielts 
with the blow-pipe into a clear green transparent 
glass s which runs and sinks on the tube of glass 
to which it has been fixed, 

^* It^ colour is blackish, and its grain re^emr 
bles that of a limestone; I wished to. see, what 
was the quantity q£ free absorbent earth that i\ns 
rock contained: I pulverised 100 grains of it, 
which I pounded for an hour in distilled vinegar ; 
this acid dissolved the half of it, and those .50. 
grains were fo)ii)d composed of 44 grains of lime 
and 6 of magnesia. The other 50 grains which 
had refused to dissolve in the vinegar, were 
placed in decoction in aqua regis s being dis- 
solved assisted by heat, 17>47 grains of lime^ 
2,25 of argil, and 1^43 of iron, were extracted 
from it, there remained S7 grains and a half of 

VOL. II. o 



194 DOMAIN X. IVAtfSILIENT. 

indiBSoloble sUiceou ^r(h. Unitiiig the pro« 
duotd oi these two operatidUH 100 grains of this 
schistus were found to contain. Lime ^hA5, 
Slez V7/iO^ Magnesia 6,00, Ai'gil 3,ft5, Irdn 
iMf Water, air, and lofs l^. Total 100,00. 

*^ The layers of this sohistns am inteniiingled 
with laj^rs <^ a ftne sandrtona; but little cohe* 
rentj and which resotres of itself in a^ white sand, 
found in quantity at the fool of theee same layers. 
The weak gluten, which imttes these grains of' 
wnd, is of a calcareous nature^ 

^* These layers are a little bent ; but their ge- 
neral position, of those at least which are the 
hmest, is vertical, eavoepting by a few degrees^ 
in which they reclino against the mountain. 
There can be no do^bl on the position of the 
beds of these sckisti, because they are exactly 
paraHel t<y the fdales of whith they we eom^ 
posed, ' But these layers are cut here and there, 
and at right angles, by clefts parallel to one an« 
other, and which all bend alike, ^teseendtng to 
the S. W. under an angts of about 50 degrees. 
These clefts' leave intervids between themj here 
h foot, there only a few inches. When they we 
observed at a distance, it is impossilrfe not to 
take them for divisions of the beds of the rock, 
so nteportant is it in these researches to see the 
object cfose^ and observe it kk detail; for the in^ 



TABIOUS. IQg 

terior siructnf e of the rock can alone decide be- 
tween sections which efoss ftt right angles, which 
are th^se whieh denote the position of the beds. 
I have alread|y mentioned whal I thought of the 
origin of the fii^oMs which thus cut the beds^ 
and I dha}) elsewhere refer to it again. 

^< I hslre distinguished four irery distinct shades 
in the transition of these schisti to granites. 

'* The first layers of schistus, where some al- 
teration is observed, assume plates more wavy, 
brighter, more resembling mica ; but they have* 
otherwise the iKutue properties with the others. 
- " The next are still more waved, plates of real 
mica are observed, and besides a mixture of 
quarts, which yields fire with steel, although the 
rock still effervesces with acids. Veins of a black 
substance are observed in this same rock, bright. 
Composed of little' rhomboids^ which appear to 
be the cfystallisatioii of the purest substance of 
the schistus; for these crystals- dissolve with e& 
fervescence in acids, without leaving any percept* 
tiWe residue; and yet they veiy easily melt 
under the blow^pipe into a greenish ihid trans* 
parent glass, which sinks ou the point of the 
glass tube. 

**The third shade is a red quartz, mixed 
with a little. mica, and which does not effer- 
vesce. 

OS 



196 JD^MAIN X. T1ANSILIENT« 

^< The fourth is a grey granite, with very small 
grains of quartz, felspar, and mica. 

<^ This transition in general occupies an in^ , 
considerable thickness; in some places these 
four layers, taken together, are not more than a 
foot : neyertheless, the granite does not acquire 
all its perfection, its grains are not very exact 
and distinct, till a distance of some feet from its 
junction. Layers are observed in this perfect 
granite; they are parallel to all those vi^hich 
form this transition. 

<' Following it round the mountain, I traced 
this junction of schisti to a considerable distance, 
by sounding every where with a hammer the. 
bordering beds : I observed no particular differ* . 
ence in the nature of the layers, which form 
the transition between granite and schistus ; but 
I found some alteration in the position of the 
beds: advancing towards the S. W. I observed 
schisti as well as granites overhanging towards 
the valley, here of 35, there even of 47 degrees. 
The direction of the layers also changes a little. 
Those nearest to Col Ferret run to the S. S. W., 
while those most distant from this same Col, run 
about 30 degrees more to the west 

« I observed also, in some places, vitriolic 
effervescences which distilled, sometimes from 
the schistuS; sometimes from the granite itself." 



VARIOUi. 197 

In his interesting account of the extinct vol* 
cano of Beaulieu, in the south of France, he thus 
describes a singular stone, which was supposed 
to be transilient, or passing from limestone to 
flint. It probably rather belongs to the Diamic- 
tonic ; but the remarks of Saussure rather place 
it in this division. 

<< The upper beds of that rock appear to me 
calcareous, oHnpact; but the lower, or those 
which approach nearest to the supposed orifice 
of the crater, are of a substance that has been 
confounded with petrosilex, but whose essen« 
tial characters differ from it. I call it silici-calx, 
because it i^ composed of silex mixed with cal- 
careous earth* 

^^ It is of a white colour, which, in some spe- 
cimens, inclines to a grey, in others to a red. 
Its fracture is perfectly conchoidal and smooth, 
but without lustre, and of a fine paste. It can- 
not be called scaly, although in some places 
there are large scales. Its fragments are sharp, 
and translucent on the edges. It is a little more 
than semi-hard, only being capable of being 
scratched with the point of a knife, and yielding, 
though rarely, some sparks with steel. 

^' It makes a weak and long effervescence 
with acids ; it then loses a great part of its hard* 
ness, but however not so much as to become 



1^ . DOMAIK X. TAAKSILXEMT* 

friable or spotty; and ito e^ges tliAti bMpme 
more traaslucent. 

f ^ Reduced to powder, and digested in the 
nitrous acidf it loses 46 hundredths of its weights 
and the residuum, of a fine white, and truly mil* 
ceotts, dissolves witii effervescence in the mineral 
alkalK It is cold to the touch: its tp^&hc 
weight is 2;90L 

^* Under the bkuw-pipe it begins to crack m 
little, then it mdtsin boiling to a nrhkie scoria $ 
the fusibility of which expressed by a globules 
equal to 0,8, answers to 71 degrees of Wedge-» 
wood's thermometeri but the small fragflEients 
that have been digested in the nitrous tteid, are 
much more refractory, on account .«f their being 
deprived of tb« calcareotts earths the prisictple 
of their fusibiUty. Globules of tbetm can onlj 
be formed equal to 0^04, corresponding with the 
1496 degree of Wedgewood, 

<< There are some small knots of flint scattered 
" in the interior of this stone ; and its 8urfiu:e 
is frequently covered with pretty black den*^ 
drttes. 

*' I hate already observed, that naturalists 
have confounded the stones of this kind with 
petrosiiex, and particuktrly with the petrcsilex 
^tquabilis of Wallerins. But its properties jire 
too remarkable, and too different from those of 



tteseoMKkrypetforileK or horntletn of Werner^ 
not to ibm a aepamte kind^ 
• ^* Besides, the effervescence arising from cal« 
oaraovB earthy scattered amongst the dements, 
as in the sUkicalcey mnst be well distingnished 
flom that which arises from calcareous parts^ 
accidentally eadosed between the leaves ( or in 
the vehis of secondary petrosilex^ which have a 
vaned or schistose fwm. 

^ Very near this, in the fleidsi are found frag- 
ments of common compact limestone, dkhur 
kallMem of Werner, fliU of sea^shells, and above 
aUofiptf^screws, or tubercular strombitei^ There 
am also frequently found in the same stones 
vmns of common flint." f 

In another pessi^, § 1^ 97» our esorilent au» 
thor describes the same substance, and the rocks 
which accompanied it As his work will pro- 
bably nevCT be translated^ no apology needs be 
offisred for inserting the passage, though some- 
what long. On his route from Aix to Avignoo, 
he perceived along the high road horiaontal beds 
^ a whitish limestone, which alternate with 
beds of an eatth of the same colour. These beds 



* '* I tl^pk we mml t^kx to diit gennt the itono known al 
Borne try the name oiSelce de Madrid, FUrini Gabiiietto Mine- 
lalogicOy U 1. p. iGl.** 



^OO DeifAIN X.- TftANtlLIBNT. 

of stone enclose, in the middle of their thickness, 
another stone in which are contained kernels of 
flint 

^^Each of these^ beds, whose thickness varies 
from one inch to five or six, is therefore .com- 
posed of three dijSerent substiances: 1. White 
stone s 2. Brown stone ; 3. Flint. 

^* White stone. No. 1, forms the upper and 
lower part of each bed ; it is calcareous, of a 
■white approaching to red ^ it breaks in irregular 
uneven fragments, with obtuse angles ; its frac* 
ture presents a mixture of grains, more or less 
small, shapeless, earthy, and without any lustre. 
It is rough to the touch, and stains the hands a 
little ; it is soft, but however less so than chfeilk. 
It therefore differs from this by being a little 
more hard, and by a coarser grain. It dissolves 
in acids with considerable effervescence, and 
leaves behind a small argillaceous sediment. 

** The brown stone. No. 2, which occupies 
the middle of the beds of that kind of chalk, is of 
a clear Isabella-brown ; it breaks in conchoidal 
fragments with sharp edges, and whose angles 
and small scales are translucent; its fracture i^ 
compact with scales, being sometimes very 
-small, sometimes pretty large. Its lustre is 
^eak, a little shinipg ; its streak is of a whitish 
grey} its hardness rather more than that of 



VAftlOUt. ,201 

marble^ although it.yields no sparks with steel. 
In the plac^'Where it borders on the chalky stone, 
Jt. melts into it by gradnal shades. Under the 
blow'pipe it is changed, though difficultly, into 
a beautiful white scoria, besprinkled with small 
bubbles; the fusibility of which, expressed by a . 
;globule equal to 0,3, answers to the 189 degree 
of Wedgewood. 

•. ^< It effervesces in the nitrous acid with many 
little bubbles.; and a small piece, of the thick- 
-ness of a line, after remaining in it twenty*four 
-hours, is found to have, lost m,uch of its hard- 
ness, especially att the surface ; it even stains a 
little brownish, and breaks between the fingers, 
without however being reduced to powder. Its 
fusibility, is then only 0,13, or 581 degrees of 
Wedgewpod. 

. «( According to these characters, it is a kind 
of the stone which I have described in 1524, by 
the name of silicicalce. 

<^ The nodules (3) enclosed in that brown 
stone, are of a fawn*colour, translucent, hard, 
their fracture perfectly conchoidal, smooth in 
some parts, a little scaly in others, having, in 
short, all the characters of true flint, or of the 
feuerstein of Werner. 

^^ These nodules of flint are scattered in the 
brown stones yet they more frequently occupy 



f03 OOKAfK %M TKANIIUKHT. 

the upper and lover part of tfae bed of tluB 
stamey and are fonnd thos cootigiioin^ on the one 
side to the white chalky stone^ and on the other 
Ao the silicicaloe. There are also scattered heie 
and there^ in the body of the chalky stone, some 
small flints^ and some small silicicalces, which 
are not fragments, but pieces formed in the spots 
they occupy. 

^ These observations and experiments appear 
to me to prove that these intermediate kinds we 
have sometimes represented as passages from one 
kind to another, or as limestones half metamoN 
phosed into flint, are often only mechanical 
mixtures of one kind with another. We here 
see that the calcareous earth has preserved in 
this petrosilex all its solubility in acids; and 
when we extract it from the mixture, what ve^ 
mains separated from the dissolvent, is still re* 
fractory like pure silex« 

^^ I shall also draw an example from this stone 
of the insufficiency of the external cbamcters of 
a rock to determine its nature, and even oidy to 
decide whether it be simple or compound. In^ 
deed in the silieicalce, the calcareous parts are 
not combined with the siliceous, since the nitncmt 
acid extracts them with ^ervescence without 
destroying the aggregation of the stone. They 
ure then only interposed between the siliceous 



eknents ; however, the whole that reailts from 
it, obsenred even with a strongmagtiifying g^as8» 
appears to be absolutely homogenouf ; and ought 
oonieqaently^ according to the nde of the litho^ 
logical nomenclatutet to be dons idered as a siin- 
pie stone. 

<^ If then we owe gratitude to Mr* Werner, for 
having given to the exterior characters all the 
perfection of which they were susceptible; we 
must ODiit no means which may afford us lights 
upon the nature and composition of bodies, with 
which onr senses alone are incapable of furnish* 
ingM. 

^ We frequently find on the same road, be« 
tween Aix and Lambesc, the same flints en- 
closed in chalky calcareous stone/'* 

His accowit may also be subjoined of a sin- 
gular nsflrmhlagr of heterogenous rocks, which 
could not well be separated, as the sudden tran- 
sitions form their chief curiosity. These he dis- ^ 
covered on Mont Jovet, between St Vincent and m^^jovL 
Verrex, not far from the city of Aosta; being 
constant alternations of arrects or uprights of 
fleatite, basaltin, siderite, garnet rock, and cal* 
careous granitoid. 

Serpentine, with brilliant plates of green trans- 

• Saws. 1694. 



1204 POMAIN X. TAANSIUBNT. 

parent talc, sometimes undulated, at others 
fibrous or laminan 

A large rock of siderite, partly very hard, 
and yielding sparks with steel ; partly laminar, 
and more tender* The hard part marbled with 
brown, from the decomposition of the iron. It 
is crystallised. 

A massive garnet rock, either in mass or con- 
fusedly crystallised with deep green siderite, in 
brilliant needles, being a mixture of the greatest 
beauty^. The infusibility of the garnet, Saus- 
sure ascribes to the refractory matrix s a remark 
that may be applied in many other instances^ 
and chemists should often analyse the gangart. 

Another rock of siderite, brown where com- 
posed of flat plates, green when of little needles, 
confusedly interlaced. His greenish schistus, of 
a fine pierre de corne^ seems a chlorite slate. 
• The calcareous granitoid of limestone, quartz, 
and mica, alternates repeatedly at Mont Jovet 
with the other rocks; and Saussure observed 
another kind, consisting of rhomboidal calcareous 
spar of a fawn-colour, of ^ pure white quartz, 
and white talc, in soft brilliant plates; a most 
beautiful and uncommon rockf. 



* Some fragments are of pure red. 
t Sauss. g65. 



VAftious* 205 

. Among the trftnsilient rocks may also be cla^s- . 
ed many which are imperfect in their stracture, 
and so irregular in different portions, that they, 
embarrass the scientific inquires In fact, rocks 
of this nature constitute a large portion of the 
globe; while the specimens in cabinets chiefly 
consist of what are called well characterised. 
To detail and class these imperfect rocks would 
be infinite, and uninteresting, so a few observa- 
tions may suffice. 

Great Britain and Ireland, in particular, often imperfect md 
afford irregular and imperfect rocks. Even the orBnuiB. 
granite of Scotland rarely presents the regular 
crystallisation observable in that of some other 
countries; consisting chiefly of felspar, with a 
little quartz, and remote spangles of mica. Dr. 
TownsoD, in his mineralogy of Shropshire, has 
specified many irregular rocks of this kind; 
such as an imperfect or ill characterised granite^ 
composed of red felspar, white quartz, and 
blackish green hornblende. But this appear- 
ance only occurs in the most perfect specimens ; 
while in general it may rather be called a sand« 
stone, seemingly formed by deposition. Such is 
also the rock of Raglitb, formed of grains of fel- 
spar and quartz, in an earthy base*. 

• Townson's Tncti, p. l63» l6«, 188» kc. 



906 BOMAIN X. fflAMsaiSNT. 

MaifeiBbiJia. The Bimeralogj of the Malvern hillsi in Wor- 
cestershire, also presents severiU imperfect rocks, 
of the nature of granite, and cheft, and wacken, 
with mica slate and schistose siderrte. B&t this 
intelligent writer's own description wHl convey 
the clearest idea. He introduces it by the fol* 
lowing observation^ which indicates their proper 
place in this division : '^ All these rocks fre* 
qntn^ypass imperceptibly into each other j whence 
arise various strange mixtures^ and imperfectly 
characterised fossils/' 

<« These rocks are singularly blended together. 
In some parts the granitoid rock, which contains 
scarce 4my mica^ runs as it were in thick irregu- 
lar veins, or forms patches amongst the wacken 
and chert ; and these likewise are similarly si- 
tuated amongst the granite, sometimes the 
one, sometimes the other, forming the principal 
mass. 

** In walking over these hillsj I collected the 
foUownig specimens; none of which I found 
any where to constitute a considerable portion 
ef them, except the granitoid kind; and this^ 
though greatly varying in its nature, I found in 
considerable rocks on the summit of the ridge 
between Great Malvern and the Well House. 

** !• Red granite, with, scarce any silver mica, 
and a little hornblende. 



▼ASlOUf. 



207 



^ 4* Fat quArts, in which a few particles of 
red felspar are imbedded, 

<' 3. Qnarte and felspar united in equal por- 
tioss, rather in short stripes than in grains, with 
a few minute spangles of mica. The different 
components being in yery small quantities, con^ 
stitute a body which, at first sight, appears ho* 
mogenous. 

<< 4. Quarts and fidspar, in such minute grains 
as to resemble a sand-stone. 

** 6. Red compact felspar? In this I cannot, 
even with a good lens, distinguish any admixture 
<^ quarts; but when held in a particular direc- 
tion, the silver mica is visible. I conjecture this 
fa be of the same nature as the preceding, but 
to be composed of much minuter parts. 

^^ 6. Red granite, or rather felspar and quartz, 
forming a vein or stripe in spatous (granular) 
hornblende i which is likewise interspersed with 
red particles of felspar. 

^* ?• Two stripes of the preceding granitoid 
mixture, separated by brownish mica. - 

'^ 8. Stripes of the preceding granitoid mix* 
ture ^bedded in, and separated by, a greenish 
mass, probably of the nature of hornblende. 

<^ 9. Red felspar, in irregular spots or blotches 
of the size of a large pea, and in smaller parti- 
cles, in greenish spatous hornblende. 



•OUAIH X, TIAKSILIENT. 

. *' 10. Black spatoQS hornblende* interspersed 
with small particles of red felspar. 

*' 11. Fine grained black spatoue bwnblende, 
interspersed with very few and very minute par- 
ticles of reddish felspar. 

" 12. A brown stone* and, to the naked eye,- 
ich is a mixture of 
[ felspar and black 
f minute particles. 

pot of siskin green 
lapis nephiiticus, or kind of jad. 

" \5. A mixture of hornblende and tlie same 
lapis nephriticus, with some quartz, all so inti- 
mately mixed as to form nearly a homogenous 
basis or ground, in which are small streaks and 
particles of red felspar. 

** 16. Reddish grey petrosilex, including a few- 
particles of pellucid felspar. 

" All these specimens are from about three or 
four miles of the centre of the chain } the other 
parts of it I never examined."* 

• Townsoo'i TracU, p. 8l6. 



DOMAIN XI. 

D£C0MK>SED. 



XHE decomposition of rocks forms a 
strikiog feature in geology, as a great part 
of the productive soil, and many of the 
substances used in important manufac- 
toriesj may be considered as chiefly derived 
fiom this circumstance. Several of the 
most useful clays are reputed by some to 
be merely decompositions of felspar ; the 



1 



210 



DOMAIN XI. DSCOMPOtED. 



Loam* 



HoQld. 



xpixture of sand being a decomposition of 
quartz. Bergman found the loam near 
London^ to contain only 13 of argil ; the 
remaining 87 being a redish grey sand, as 
fine as flour. What is called mould, con- 
sists chiefly of vegetable and animal re* 
mains* The fall of leaves in a forest 
creates a fine black mould. 

In various parts of England, and other 
countries, the loam is of a red colour, and 
proceeds in what may be called belts or 
zones (for strata can only be superimposed 
on each other) for a great distance, but 
with various interruptions. This red tinge 
can scarcely arise from tbe decomposed 
felspar of red primeval granite, as some 
have supposed ; for in that case the hardest 
nodules of the granite would probably still 
be found, as in the red aand-^tone; but 
may merely proceed from the admixture 
of red oxyd of iron, while in other spots 
the black oxyd may predominate. Ai^* 
laceous earth is found in the most primitive 
substances; and theory cam scarcely be 
expected to determine whether the 



OOMAIW Xt. DBCOMFOtlO* Sll 

clay, which forms so prodigious and import^ 
ant a portion of the surface of this globe^ 
and furnishes aliment to animals atkl ve- 
getables, arises from a decomposition 6& 
fected, during myriads of ages, by the 
superincumbent waters ; or by a mere de* 
position from the original mass and consti* 
tution of the waters themselves. 

On the decomposition of rocks, tikd ob» 
servations of a skilful chemist must be 
particularly exact and interesting, for whidi 
reason those of Mr* Kirwan are extracted ; 
more especially as they abound with ex» 
amples which are essential to the nature of 
the present work. It may also be pre- 
ftced, that the decomposed rocks have 
never hitherto been tieated in any profess- 
ed work of mineralogy, so that the novelty 
of the subject calls for eveiy aid of illus* 
tiBtion. 

" Decomposition consists in the separa* J^SSL 
tion of the constituent parts of a stone, or 
other substance ; and may be either total 
or partial* Disintegration denotes the se« 

PS 



CKOlilMUkMb 



213 0OMAIM Sir DBeOMPOSEOw 

paration only of the integrant parts ; botli 
often take place in the same substance. 
CM«fc " The only causes of mere disintegration 
as yet known, are the vicissitudes of the 
titmosphere; the absorption and congela* 
tion of water; the sudden dilatation or 
contraction produced by the former, par. 
ticularly when extreme, cannot but lopsen 
the texture of most stony substances, and 
when aided by the absorption of water, 
strongly tend to separate them. The water 
thus received in their minutest rifts, being 
afterwards frozen, bursts them with incre^ 
dible force, of which frequent instances 
occur in the northern countries, and in the 
more elevated mountains of the southern, 
where the most sudden transitions of heat 
and cold, and the highest degrees of the 
latter, frequently prevail; and hence the 
broken craggy state of their loftiest sum* 
mits*. 
^^ The known external causes of decom« 

* Crantf has informed va that, in Grreenkodj the rocks are ofte» 
heard to hunt with a noise like thonder.-*P. 



1X)VAIN XI. DBC0MP08BD. 21S 

position, are "water, oxygen, and fixed 
air. •• 

" The internal causes are, the bases most 
capable of forming a union with the exter- 
nal : as saline substances, sulphur, slightly 
oxygenated calces of iron, or of manganese^ 
lime, argil, bitumen, carbon, and mephitic 
air ; which is certainly contained in many 
stony substances, as Dr. Priestly has shown 
in the first volume of his last edition, p. 64; 
but as to its nature and effects, they are at 
present too little known ; all these are as- 
sisted by a loose texture of the substance 
acted upon. 

" Saline substances, particularly when ^ts. 
(relatively to their mass) they present a 
large surface, are dissolved by water, and 
consequently the stones, of which they 
sometimes form a component part, are de- 
composed ; thus muriacite, which consists 
of 27 per cent gypsum, 14 common salt, 5 
mild calx, and 53 micaceous sand, must be 
decomposed when long subject to the ac- 
tion 'of water. 

^ Sulphur promotes decomposition by soiphnr. 



9J4 POUAIV XI. DBCOII9Q8S0. 

absorbing oxygen, while it is thus convert* 
ed into vitriolic acid ; but moisture is also 
Fequisite. To ibis cause the decomposi- 
tion of such stones as contain pyrites is to 
be attributed; it seldom acts, however, 
unless united to some metallic substance ; 
and hence its combinations with argil, un« 
less assisted by heat, are not sensibly de- 
composed, or only in a great length of 
time. 
oxydofiroB. « Calces of iron, tnoderately oxygenated, 
ai« the zoofit general cause of decomposi* 
tion, particularly when assisted by a loose 
texture, and the other causes of disinjte- 
gration; these act by absorbing a greater 
proportion of oxygen and fixed air, but re« 
quire also the assistance' of moisture* By 
this absorption they gradually swell, and 
are disunited from the other constituent 
parts of the stone, into whose composition 
they enter. When least oxygenated, their 
colour is black, or brown, or bluish ; and 
in some instances, when united with argil 
and magnesia, grey or greenish grey ; the 
former in proportion as they become more 



DDMAUr ZI. DBCOlftOtBII* {l^ 

oxygenated, beoorae porple, recU ^^ntgCf 
and finally pale yellow ; the lal:ter becxnaen 
at first blue, then puiple, red^ i&c. 

^^ Iron in its perfect metallic $tate, or at 
least but slightly oxygenated, also decom-; 
poses water ; but if exposed to the air, it 
becomes farther oxygenated ; andthecom-t 
pound into wfaieh it eaters gradually 
withers, ns Dr. Hi^ns observed, in imi^ 
tating pouz2olaflia (oq Cements, 124). 

^^ But stones, into whose compositioa 
calces of iion highly oxygenated seem to 
hav^e originally entered, are very difficultly 
decomposed, as red jaspers, ice, as they 
already possess nearly as much as they can 
absorb. 

^ ManganfMC, when sli^tly oxygenated, 
is known to attract oxygen strongly, par- 
ticularly with the assistance of heat and 
moisture; hence it is, in many cases, a 
principle of decomposition, as in siderocal*- 
cites, &a ; it also frequently assists or pix>9 
motes tiiat effected by calces of iron. 

^^ Lime, firom its attraction to fixed air, Lime, &c. 
and ibs solubilily in water, must promote, 



216 l>OlffAJH XI. DECOMrOfEO. 

in favourable circumstances, the decom- 
position of stones, of which it forms a con- 
stituent part; to it the decomposition of 
felspars, and many zeolites, may in part 
be attributed. 

" Argil, when its induration does not ex- 
ceed 7 J must, by the common annual vi- 
cissitudes of heat and cold, gradually be- 
come rifty, absorb, soften q.nd swell, and 
thus promote disintegration and decompo- 
sition. 

" Bitumen is said to form the cement of 
some limestones, and probably of various 
other species. Bowles found it so in va- 
rious parts of Spain, and Flurl in Bavaria; 
and to its fusion and withering (probably 
by attracting oxygen), he attributes the 
disintegration of several compact lime- 
stones in Bavaria (p. 78). 

" Carbon has lately been found in several 
species of stone ; as it powerfully attracts 
oxygen, to it we may perhaps attribute the 
disintegration of many of them, as marls, 
marlites, some argillites, shales, &c. 

Mephitic air (the azote of the French) 



<c 



DOMAIN ZI. DBCOMPOSBO. 217 

» 

by its property of forming nitrous acid, 
when, during its nascent state, it is gra- 
dually brought into contact with the oxy- 
gen of the atmosphere, in a moderately 
dry state, may also promote decomposi- 
tion ; calcareous stones are known to con- 
tain it in pretty considerable t)roportion, 
and those that contain animal remains, pro- 
bably most ; from this qonsideration we 
may derive some explanation of a very re- 
markable phenomenon, related by M. Do- 
lomieu 36 Roz. 116. *A11 the houses of 
Malta are built of a fine grained limestone, Limestmie of 

° . Malta. 

of a loose and soft texture, but which 
hardens by exposure to the air. There is 
a circumstance which hastens its destruc- 
tion and reduces it to powder, namely, 
when it is wetted by sea water ; after this 
it never dries, but is covered by a saline 
effervescence ; and a crust is found some 
tenths of an inch thick, mixed with com- 
mon salt, nitre, and nitrated lime ; under 
this crust the stone moulders into dust, the 
crust falls off, and other crusts are suc- 
cessively formed, until the whole stone is 



destroyed. A »ii^e drop of sea water is 
sufficient to produce the germ of destrac*- 
tion ; it forms a spot which gradually iur^ 
creases, and spreads like a caries through 
the whole mass of the stone : nor does it 
stop there, but after some time affects all 
the neighbouring stones in the wall. The 
stones most subject to this malady are those 
that contain most magnesia ; those which 
are fine grained and of a close texture, resist 
most/ Short as this acoount is, it appears 
from it that the limestone of Malta coop* 
tains both calcareous earth and magnesia, 
but most probably in a mild state ; and 
the stone being of the looser kind, is of 
the species which is known to contain most 
mephitic air. M. Dolomieu shows, at the 
end <^ his tract en the Zipari Islands, that 
the atmosphere of Malta in some seasons^ 
when a south wind Uows^ is remarkably 
fouled with mephitic air; and at other 
times, when a north wind blows, remaiki* 
ably pure ; and hence^ of all others, most 
fit for the gienemtion of nitrous acid.-^^ 
Agauu sea water^ besides common salt. 



OOMAIV XI. DMOUrO$MtK 



219 



contains a notable proportion of muriated 
magnesia^and a small proportion of selenite. 
From these data we may infer^ that when 
tibis stone is wetted by sea water» the sele- 
nite is decomposed bj the mild magnesia 
contained in the stone, and intimately 
mixed with the calcareous earth. Of this 
decomposition, two results deserve atten^ 
tion : 1. the production of vitriolic Epsom. 
9. the extrication of mephitic air; the 
muriatic magnesia of the sea water serving, 
during this extrication, the purpose of at* 
tracting and detaining a sufficiency of 
moisture. This air thus slowly generated, 
and meeting the dry oxygen of the atmo* 
sphere, forms nitrous acid, hi^y me{dii* 
tised ; but it soon acquires a due propor-^ 
tion of oxygen, by deoxygenating the vi- 
triolic contained in the Epsom salt, which, 
by successive depredations of this sort, is 
gradually destroyed. Part also must unite 
to the mild calx, which in its turn is de» 
composed by the remaining mild magnesia ; 
more mephitic air is set loose, and more 
nitrous acid is produced, until the stone ia 



f 20 D0MA1V XI. PECOMrbtftl>. 

destroyed. How the alkaline part of the 
sitre, which is one of the products result- 
ing from the decomposition of this stone, 
is formed, is as yet mysterious ; is it not 
from the tartarin lately discovered in -clays 
and many stones ? I am as yet inclined to 
think, that it is derived from the putrefac- 
tion of vegetable and animal substances; 
and though nitrous acid formed of oxygen 
and air, from putrefying substances, be 
found united not only to the absorbent 
earths to which it is exposed, but also* to a 
fixed alkali ; yet I should rather suppose 
that the alkali is conveyed into those earths 
by the putrid air, than newly formed ; and 
the reason is, that tartarin, notwithstand* 
ing its fixity, is also found in soot; and 
in the same manner may be elevated in 
putrid exhalations. As to the common 
salt, said also by Dolomieu to be found in 
the blisters of this mouldering stone, I am 
as yet in doubt ; for common salt was also 
said to accompany the native nitre found in 
the pulo of Apulia ; yet Klaproth, in ana« 
lysing this nitrated earth, could find none : 



irOMAlN XI. DBCOIIPOIBDI. g2l 

iee Zimmerman's account of this native 
nitre. {36 Roy. 1 1 1 , 1 13, and 1 Klap. 319.) 
^^ So also when the calx of iron contain- 
ed in $tones is but slightly oxygenated, it 
may, by reason of the close texture of the 
stone, remain undecomposed for ages ; but 
if by any accident, as fracture, or contact 
with some saline matter, or the alternate 
reception and dismissal of water, the re- 
ception of more oxygen is facilitated, a de- 
composition will commence, which, as in 
the former case, will spread like a caries, 
because the less oxygenated part of the 
iron takes oxygen more easily from the 
more oxygenated part, than from the at- 
mosphere; by reason, that the absorbed 
oxygen is more condensed than it is in the 
iktmosphere. Thus iron inserted into a 
highly oxygenated solution of vitriol of 
ircm, and which therefore refuses to crys- 
tallise, will take up the ^excess of oxygen, 
and thus restore the solution to a crystal- 
lisable state ; or as calx of tin takes up 
oxyg^i &om calces of silver, antimony, &c. 



I 



222 DOUJLIK XJ» DBC01IP08BD. 

in the beautiful experiments of Pelletier^ 
(12 An- Chym. 229, &c-) 
Fwwnons « Hence also, ferraginous stones near 
or upon the surface of the earth, being 
more exposed to air and moisture, and the 
disruptive action of growing vegetables^ 
vrhose roots pierce through their minutest 
rifts, and by swelling burst them, are more 
exposed and subject to decomposition. 
Water carries down the ferruginous parti* 
cles into the lower strata, and forms there 
those illinitionB and masses of pisiform ar« » 
gillaceotis iron ore, which Bu£fon and others 
have, without sufficient reason, derived 
from decayed vegetables. 

^ Basalt, when pure, strongly resists de* 
composition, or its surface alone bears any 
marks of it ; the argillaceous, siliceous, and 
calcareous ingredients, and part of the fer- 
ruginous, soon recombining and forming a 
hard crust, which invests and protects the 
wacken. remainder of die stone. But wacken is 
very eausily decomposed; and henoe the 
basalts or traps, into whose compoeitioa 



U enters, yield easily to the decomposing 
priociple. Sk^ne granites, I may say most^ 
aie in appropriate circumstances not diffi- 
cultly decomposed, the mica and felspar 
are ehiedy affeeted : the same may be also 
said of most sand-stones, pcurticularly those 
whose ccnent is argittaceoQs or feiruginou9, . 
and many poiphyries and gneiases«'^ 

From these interesting obaervatioas it ^^StS! 
fvill appear, that the decomposition of 
rocks is not cmly a curious subject in itself^ 
but of tlie greatest importance to the arts, 
particularly architecture and sculpture. 
Msoky noble edifices have soon become 
disfigured, because the architect did not 
kaow the easy decompositi<»i of the mate* 
rials. Thus at Trianon the pillars are al« 
ready decayed, because the argillaceous 
UAtuie of the marble of Campan will not 
beaor exposure in the open air^ where it soon 
exfoliates.. At Oxford it has been observed 
that some of the public buildings are ia« 
juredy because the builders had not studied 
the nature of the stcme, which requires to' 

• KLrwiA*»0«olog|bd Bttiys, p. 143—1^. 



224 DOMAIN XI. ' DECOM^OfBlK 

be laid in its original position in the quafry^ 
that the first compression may still exist, 
as otherwise it will imbibe the moistiirel 
and thus split or crumble in frosty weather! 
Sculptors are singularly anxious that the 
stone which they use- should not be subject 
to this defect; and their example should 
be followed by architiscts, as the duration 
of their works and reputation depends en- 
tirely on this branch of knowledge. It 
would appear that the ant^ients, who always 
mingled the useful with the ornamental, 
had particularly investigated this subject^ 
even in very eariy times ; forthfe Egyptians, 
in their eternal mobumeikls, had already 
learned to prefier grailite and porphy ry^ the 
two most durable substances in nature; 
and which have the additional advantage 
thact they afford no temptation for destruc- 
tion^ because they cannot^ like mafble, 
be * converted into lime : for some of the 
noblest monuments of Greece have been 
used for this purpose by the barbarouis 
Turks ; and a tetaiple or statue of Diana 
has been turned into cement, for the voiup- 



DOM AIH XI* DEGOMPOBBOb 2S5 

tuous apartments of a , Haram. It is also 
conceived by antiquaries, that some of the 
finest monuments of ancient Rome perish- 
ed in this manner during the middle ages. 

It must not be forgotten that stones ap- ^JJ^jJl^ 
parentlj hard, are sometimes more subject 
to decay than those of a softer contexture* 
The pyramids of Egypt have suffered little 
degradation, though constructed with a soft 
calcareous konite*. The Roman Pharos, 
at Dover, remains almost entire, though 
built with a soft stalactitic tufa, found in 
abundance on the shores of several rivers ; 
for example, the Tees, in the north of 
England. The transportation of this stone 
from a distance, seems to evince that there 
was some reason for giving it a preference ; 
and as it is coralloid in its structure, it was 
perhaps justly conceived that it would emit 
the moisture with the same eaise as it was 
received, and hence be little subject to 

* Strabo says, that one of the pyramids was more expensive, as 
the lower part was built with basalt, from Ethiopia ; a circumstance' 
wliich aoems to hti« escaped the attention of timvellers, probably 
from the white crust which invests basalt. But some were covered 
with granite : see Dom. II. 

VOL, II. • Q 



226 BOMAIM XI. DEOOMP08ED* 

decomposition* The conjecture, if suchi 
was certainly vwified bj the event. From 
this, and numerous other examples, it may 
b» inferred that the ancient architects ob- 
served, with a most scrutinizing eye, the 
nature and the structure of the stone which 
they employed ; an important circumstance 
which has not met with due consideration 
among the moderns. 

The same considerations are also of the 
greatest importance in private buildings, 
where stone is abundant and in general re- 
quest ; and the product of any new quarry 
should be put to several tests, and severely 
examined, before it be brought into use. 
The example of the houses of Malta, above 
mentioned by Mr. Kirwan, is a striking 
lesson of this kind; and some modem 
buildings in Scotland are more decayed 
than the ancient. If iron, clay, or even 
perhaps some magnesian mixtures, be much 
intermingled, the stone is apt to become 
carious. But the magnesian rocks in ge- 
neral are littk suljgect to decay ; and ser- 
pentine, resisting moisture by its unctuous 



POMAtN XI. DECOMFOfBDi S27 

BSiture, forms somfe of the boldest summits 
and promontories. It was perhaps this 
consideration which induced the preference 
of bllite, or potstone, in the construction 
of the Diike of Argyle's noble mansion at 
Inverary. 

These observations can scarcely demand 
excuse, as being digressive, for the utility 
Qf any subject is its most laudable quality : 
nUi utile est quodfacimusy stulta est gloriam 
But to return to considerations more imme- 
diately connected with the nature of this 
work, it must not be forgotten that the 
able illustrator of the Huttonian theory, 
has treated the subject of decomposed 
^ks. which maj be said indeed to form 
the very foundation of that system, with 
his usual talents ; but not with tha,t long 
and laborious discussion which was to have 
been expected on a topic so important to 
his purpose. After describing the plain of 
Crau, at the mouth of the Rhone, a space 
of about 20 square leagues covered with, 
quartzose pebbles, and which Saussure ob- 
served to proceed from the decomposition 



2^ 0'OIIAni Xf. DBCOXPOSEIIu 

of a vast stratum of pudding-stone, 
underlies the whole ; the intelligent author 
thus proceeds. 
W'lyft?'* •• The argument for the decomposition 
of Stony substances, which is afforded by 
the state of this singular plain, may be 
confirmed by the appearances observed in 
many extensive tracts of land all over the 
World, and especially in some parts of Great 
Britain. The road to Exeter from Taun- 
ton Dean, between the latter and Honiton, 
passes over a large heath or down, consi« 
derably elevated above the plain of Taun« 
ton. The rock which is the base of this 
heath, as far as can be discovered, is lime* 
0tone; and over the surface of it large flintSf 
in the form of gravel, are very thickly 
spread. There is no higher ground in the, 
neighbourhood from which this gravel can 
be supposed to have come, nor any stream 
that can have carried it ; so that no ekpla« 
nation of it remains, but that it is formed 
of the flints contained in beds of limestone^ 
which are now worn away. The flints on 
the heath are precisely of the kind found ia 



DOXAIV ZI. DBCOMFOSSO. jggg 

limestoae ; many of them are not much 
worn, and cannot have travelled far from^ 
the rock in which they were originally con- 
tained. It seems certain, therefore, that 
they are the debris of limestone strata, now 
entirely decomposed, that once lay above 
the strata, which at present form the base 
of this elevated plain, and probably cover- 
ed them to a considerable height. This 
explanation carries the greater probability 
with it, that any other way of accounting 
for the fact in question, as the travelling 
of the gravel from higher grounds, or the 
immersion of the surface under the sea» 
will imply changes in the face of the coun« 
try, incomparably greater than are here 
supposed. Our hypothesis seems to give 
the minimum of all the kinds of change 
that can possibly account for the pheno- 
meoon. i 

'^ The same remarks may be made on 
the high plain of Blackdown, which the 
road passes over in going from Exeter to 
the westward. The flints there are disse- 



t 

g5(} DOMAIN XI* Z>EOO]IPO8B0. 

minated over the surface as thickly as in the 
other instance, and can be explained only 
on the same supposition. 

" Again, in the interior of England, be* 
ginning from about Worcester and Birming-- 
ham, and proceeding north-east through 
Warwickshire, Leicestershire, Nottingham-* 
shire, as far as the south of Yorkshire, a 
particular species of highly indurated gra- 
vel, formed of granulated quartz, is found 
every where in great abundance. This 
same gravel extends to the west and north-* 
west as far as Ashburn, in Derbyshire; 
and perhaps still farther to the north. The 
quantity of it about Birmingham is very 
remarkable, as well as in many other places j 
and the phenomenon is the more surprising, 
that no rock of the sajne sort is seen in its 
native place. It is such gravel as might be 
expected in a mountainous country; in 
Scotland, for instance, or in Swisserland ; 
but not at all in the fertile and secondary 
plains of England. 

^* This enigma is explained, however,. 



DOMAIN XI. DECOMPOSED. , 4|3| 

when it is observed, that the basis of the 
whole tract just described is a red sand^ 
stone, often containing in it a hard quartzj 
gravel, perfectly similar to that which has 
just been mentioned. From the dissolu- 
tion of beds of this sandstone, which for- 
merly covered the present, there can be no 
doubt that this gravel is derived. But as 
the gravel is in general thinly dispersed 
through the sandstone, and abounds only 
in some of its layers, it should therefore 
seem that a vast body of strata must have 
been worn away and decomposed, before 
such quantities of gravel as now exist in the 
soil could have been let loose. 

" I have said that a rock, capable of af- 
fording such gravel as this, is not to be 
found in the tract of country just mention- 
ed. This, however,* is not strictly true; 
for in Worcestershire, between Bromes- 
grove and Birmingham, about seven miles 
from the latter, a rock is found consisting 
of indurated strata, greatly elevated, and 
without doubt primitive, from the detritus 



£S2 DOMAIN XI. DBCOMPOftBD. 

of which such gravel as we are now speak* 
ing of might be produced. These strata 
seem to rise up from under the secondary, 
where they are intersected by the road; 
and, for as much as appears^ are not of 
great thickness, so that they cannot have 
afforded the materials of this gravel direct- 
ly, though they may have done so indi^ 
rectly, or through the medium of the red 
sandstone ; that is to say, a primary rock 
of which they are the remains, may have 
afforded materials for the gravel in the 
sandstone ; and this sandstone may, in its 
turn, have afforded the materials of the 
present soil, and particularly the gravel 
contained in it. 

" Pudding-stones being very liable to 
decomposition, have probably, in most 
countries, afforded a large proportion of 
the loose gravel now found in the soil. 
The mountains, or at least hills, of this 
rock, which are found in many places, 
prove the great extent of such decomposi* 
tion. Mount Kigi, for instance, on the 



POMAIV XXt D^poHrOBBBte 239 

side of the lake of Luoeme^ is eotirelj of 
puddiog-stone, and is 74& toiges in height^ 
measured from the level of the lake. By 
the descriptions given of it, as well as of 
other hills of the same kind in Swisserland^ 
ve may, without due attention, be led to 
suppose that they are entirely formed of 
loose gravel. Even M. Saussure's descrip- 
tion is chargeable with this fault ; though, 
when attended to, it will be found to cob* 
tain a sufficient proof that this hill is com* 
posed of real pudding-stone. The nature 
of the thing also, would be sufficient to 
convince us that a hill, more than 4000 
feet in height, could not consist of loose 
and unconsolidated materials. 

" If then we regard Mount Rigi as the 
remains of a body of pudding-stone strata, 
we must conclude that these strata were 
originally more extensive; and the adja- 
cent valleys and plains will serve, in some 
degree, to measure the quantity of them 
which time has destroyed.''* 

• Playfair, 373. 



f 34 DOMAltf XX. OBCOMPOSBlh 

The noveky of the topic, in a professed 
work of this nature, will be a sufficient 
apology for the length of these introductory 
observations : but it is now proper to pur- 
sue the plan proposed, by an arrangement 
of the chief decompose4 TOQks. 



VOIIS X* D. BASALTIK. 235 



KOME I. DECOMPOSED BASALTIN. 

The German mineralogists have not been de- 
ficient in their observation of this curious ap- 
pearance. Karsten^ in his catalogue of Leske's 
poUection, has the following instances, among 
others, in the geographical series. 

HYPONOMK I. 

Basaltin. 

** L525. Very fine splintery basalt, with half of Gennany. 
decayed chrysolite disseminated, and exteriorly 
decomposed to yellowish brown clay, from Riet- 
stein, Saxpny. 

^' 1533. Basalt, in which the chrysolite is be* 
come very steatitical through decay, from the 

same place. 

*^ 1534. A piece of basalt with decayed chryso- 
lite, wherein it is quite evident that the pores ori- 
ginate from the decay of the latter, from the same 
place. 

" 1577. A piece of basalt, mixed partly with 
small grained chrysolite, partly with felspar, which, 
W is very frequently the case in granite, is decom- 
posed to lithomarga; from Wachberg, beside 
^artipansdorf. 



' 



(255 DOIUIV XI. PBCOlftOitD* 

"1667. Perfectly decayed basalt, which in 
some places contains a large quantity of earth re- 
sembling bole, with interposed basalt consisting of 
lamellar distinct concretions. 

" 1671. A pentahedral columnar tolerably large 
piece, which consists entirely of this earth, so that 
evidently the basalt must have been decomposed 
into it 

" Rem. It deserves to be noticed as a singular 
phenomenon, that a perfect hexahedral prism of 
chrysolite occurs in it. 

" 1819. A very decayed porous basalt frag- 
ment, which lay between the solid layers, and is 
called lava flag. 

" 1673. Very decayed porous basalt, which 
had better be called a basaltic amygdaloid, where- 
in are still contained abundant vestiges of the 
earth, with which these pores were formerly filled. 

" 1674. The same fossil, but the pores, not so 
uniform, are smaller and larger promiscuously. 

^^ 1675. The same fossil, penetrated more uni- 
formly with the sulphur-yellow argillaceous mass, 
which gives to the whole^ in the opinion of many 
geologists, a volcanic appearance." 

HYPONOMB II. 

Amygdalite. 



irOIIB I. B. BASALTIW. 337 

^ 305. Amygdaloid resembling basalt, in which 
small groups of zeolite occur, which in some 
places have totally lost their water of crystallisa* 
tion. 

** 306. Similar amygdaloid, out of which all 
the extraneous parts have decayed, therefore the 
whole has a perfectly porous appearance; from 
Ascherofen, in the Thuringieui forest. 

** 307. A piedB of amygdaloid in which not 
only all the extraneous parts have decayed out^ 
but the basis itself is also very much decayed ; 
hence such varieties are not unfrequently called 
pumice ; from Upper Lusatia." 

As the opinion concerning the volcanic nature 
of basaltin seems rather to gain ground, it is not 
improbable that some of those substances are 
truly volcanic. When we consider the vast num- 
ber of volcanoes in Asia and America, amounting 
to about one hundred and fifty, we may very rea- 
sonably infer that many in Europe may have be- 
come extinct. As these appearances only affect 
small spots, prejudice on either side becomes truly 

.ludicrous ; and its excess will, with rational minds, 

• 

turn the scale upon the other side. What shall 
be said, when a late writer has informed us, that 
pumice itself is commonly a Neptunian sub- 
stance? 



ftS^. nOMAIM XI. BEC0MF08SD. 



NOME n. D. PORPHYRY. 

In the same work^ Karsten has given the fol* 
lowing examples : 

" 208. A piece of porphjoy in which the fel- 
spar is indeed entirely, but the basis only $light<» 
ly, decomposed ; from Norway. 

" 209. Porphyry in which the felspar is partly 
actually decomposed, but partly appears barely 
without lustre, the basis is become perfectly fri- 
able ; from the vicinity of Regensburg, 

** Rem. It . is very frequently passed for 
tarras." 

The remarkable stone which composes the 
Tuy de Dome, where Pascal made his celebrated 
observations on the barometer, is a porphyry, 
which seems to be decomposed by volcanic heat. 
According to the experiments ^of Sayssure, the 
base is an earthy felspar, or felsite. 
.s^inti But the most celebrated decomposed porphyry 

is the saxiim metalliferum of Baron de Bom, 
which serves as a gangart to many rich mines of 
gold and silver in Hungary; and even to the 
noble opal, only found in that country. It is 
surprising that so many mistakes should have 



mettillifmtm. 



been made even by skilful mineralogists^ \vhile 
he repeatedly informs us himself that it is a grey 
argillaceous stone> mistaken by the miners for a 
sandstone^ often containing crystals of felspar 
and (Juartz^ and sometimes schorl. But in gene- 
ral the felspar itself seems to be decomposed, 
forming oblong white spots on the grey base. 
The gold and the opal would appear to have 
been formed after the decomposition of the rock. 
Opal and chalcedony are also found in entire 
porphyry 3 as well as veins of gold. The various 
porphyries of the German writers, occasion a 
strange confusion in the very nature of the sub* 
stances. 

The saxum metalliferum might as well be Bamite. 
called 3ornite> in honour of that great mine- 
ralogist. 

HTFONOBfB I. 

Bomite, from various parts of Hungary. 

Micranome L The same, with native gold in 
thin plates and disseminated, from the same. 

Micronome 2. The same, with sylvanite, from. 
Nagyag in Transilvania. 

Micranome 3. The same, with fine dendritic 
gold, from Crenmitz in Hungary. 



£40 P^VAtH XI. *BOOIIfOtl». 



BYTOVOUU II. 

MicroTiome 1. The same, with noble opal, 
from Czerweniza in Hungary. 

Micronome 2. The same^ with black opal, from 
the same. 

Micronome 3. The same, with milk opal, and 
many other kinds, from tiie same*. 



NOMEHI. D. SLATE. 

Some kinds of slate, especially those mixed 
with calcareous matter, easily exfoliate and de* 
compose. 



NOME IV. D. QUARTZ. 

This substance is far from being easily decom- 
posed; but, from some unexpected intermix- 
ture^ it sometimes though rarely decomposes in 
granite, while the felspar remains entire. Mr.^ 
Kirwan has an article concerning earthy quarts 

* See Town8oa*8 Travek in Hiiogftiy, for m ample aeoomit of 
the opal minet. 



hi in^ich one ^would expect examples of d0oom« 
position ; but the specimens rather seem to be^ 
long to the granular^ and the cellular*. Ferru- 
ginous quartz seems the most liable to decom- 
position. 



NOME V. D. KERAUTE. 

Mr. Kirwan has observed, that when tliis sub* 
stance begins to decompose it discovers the cha- 
racters both of an earth and of a stone. Kar- 

« 

9ten has the following articles. 

** S. 417« Hornstone^ which in some parts i$ 
quite decomposed to clay, and from thence has 
acquired an earthy fracture. 

'^ 493. A decomposed hornstone, which 19 
there called indurated fullers' earth. From 
^ainungen." 



NOME VI. D. FELSPAR. 

This substance which/ owing to a mixture of 
pot-ash, is not of very difficult decomposition, 
passes into bole or lithomarga, kaolin or porce^ 
lain earth, and other sorts of clay. It is part^- 



• Minu-i. 3S7* 
VOL. II. R 

9 



* / 



S4t DOHAtK XK DBCOWOSBD. 

cidMr)^ i^flfeCted in ctecomposed gramte ; td 
which nrUole the reader is referred. 



UTFONOME I. 

Felspar changed into kaolin. 

HYPONOME II. 

f 

Into clay. 



NOME VU. D. GRANITE. 

The grandeur of this substance renders all ita 
appearances interesting. The decomposition of 
granite may be considered on a large and on cL 
small scale; in the former point of view, thii 
subject has been well illustrated by Ramond, 
Pyrtneci. who has added a plate of its various appear* 
ances*. As the felspar is generally by far, the 
most abundant substance, it might have been 
expected that granite would split into rhombs ; 
but the forms cannot be called regular, though 
the sides, as Saussure has observed, are very 
plane or flat^ intersecting, as if cut, all thi^ 
fiompouent substa&ces. According to Ramondj^ 

• Voyage au Mont Perdo, p. 90, flrc. - It is to be Tfigrettcd tha^ 
a style ludictoosly empkatic and important, shomld disfigure a work, 
etherwise Gwioua and intercsltng. 






MOUM VIL D. OB AM ITS. ' 243 

the final fragmentj in th6 massive decompositton 
of granitey resembles a wedge^. One rock pre^ 
sents harder projecting veins, crossing in varioM 
directions; while the softer parts are excavated : 
perhaps a type in miniature of the granite veins 
observable on a larger scale, when the softer in-* 
tervals may have been wasted, and their place^ 
9iteT many ages, supplied by schistus. 

This massive decomposition of granitf often 
takes place on the summits of mountains* It 19 
said that Ben Nevis, the highest mountain iil 
Great Britain, affords interestiilg examples of this » 
kind; but, to the disgrace of our mineralogy, 
that mountain remains without due examina* 

tioii. . 

The high ridge of Sochondo, in Chinese Ta- sodiondo. 
tary, which gives source to the great rivers of 
Onon and At'goon, is said* to present summits 
consisting of large rocks, piled on each other iii 
iuccessive terraces. The mountains are proba- 
bly granitic, like the celebrated Odon^Tchelon^ 
m Daouria, near the same river Onon, which 

* De Lac, Geologies 305, says that granite sometimes decom- 
poses into circular portions^ the rhomhs having become spheroids. 
He sawjiiks of these in the Giant Moontains of Silelia, which, at a 
distance, resembled Dutch cheeses. 

In some granites the decomposed mica becomes chlorite 3 but it 
seems too bold to assume that all chlorite is decomposed mica. See 
Joum. des Minc^ iv. 42. 

R2 



244 ooMAitr XI. »ECoaifoii0. 

presents in its opulent bosom chrysolites^ eAe^ 
raldsy and beryls ; and which is thus described 
by an able observer. 
odoB-Tcbdoik . << Three or four leagues before arriving at the 
gang of the beryls, you begin to rise on the vast 
base of the mountain, entirely composed of the 
remains of its ancient summit. You may go on 
horseback to the foot of its actual summit, which 
is only elevated above its base about 1200 feet 
perpendicular; and it may be easily climbed on 
^ footj as it is composed of granite tolerably friable^ 
and which presents no precipices. This summit 
- js formed like a horse-shoe, at the bottom of 
which is a spring, which waters the little valley 
formed by the two branches of the horse*shoe» 
whose aperture faces the S. E. ; its extent in 
length being from 4 to 500 fathoms. /It is upon 
the slope, which rises on the right in entering 1^ ) 
the valley, that there are two gangs of emeralds: 
the first is not far from the rivulet, and contains 
chrysolites ; the second is near the middle of the 
height of the summit, rather advanced within 
the horse-shoe, and is that which contains the 
emeralds. The third gang is on the very crest 
of the summit, at the extremity of the horse* 
shoe, it contains the beryls."'^ If this celebrated 

• Patriti, ii. 84. 



HOMB Til. *D. ORAHITB* ^45' 

mountain . had not been decomposed, perhaps 
these precious miqes would not have been. dis- 
covered. * 

On a smaller scale, the most usual decompo« 
sition of granite is where the felspar assumes the 
appearance of bole or lithomarga, of porcelain 
earth, or of fine clay. The noted Kaolin of the 
Chinese forming a chief ingredient of their 
famous porcelain manufactures, is a decomposed 
felspar, which seems mostly to proceed from an 
entire rock of that substance, as there seems to 
be no quartz ; while that of Limoges, in France, 
l^e chief ingredient of the Sevres manufacture, 
may have been a granite in which the micarel is 
also decomposed ; for there are numerous grains 
of quartz, which are carefully separated. 

Granite, decomposed by volcanic heat, is 
common in Auvergne, where the lava has 
burst through superincumbent masses of that 
substance ; but such appearances may rather be 
ranked among the volcanic ; the decomposition 
here chiefly treated, being that effected by the 
influence of time and climate. Karsten has 
given the following examples of decomposed 
granite. 



246 DOtCAIW XI. l^BCOUKMBB. 



HYPONOMB I. 



46. A piece of granite, in which the felspar 
has lost only a very minute portion of the water 
of crystallisation ; from Upper Lusatia. 

" 47- Granite, with felspar somewhat farther 
decomposed ; from Konigshain. 

" 48. Granite, with felspar considerably dcr 
composed ; from the same place. 

" 49- Granite, on one side of which the felspar, 
is decomposed almost entirely to porcelain clay,, 
but on the other not quite so much decomposed ; 
from the county of Glaz. 



HTPONOMB II. 



50. Granite, in which the mica is decomposed 
into steatite, but the felspar ver/ slightly; from 
Siberia. 

^' ^1* Granite with mica and felspar, quite de^ 
composed ; from the vicinity of Meissen. 

'' Si. Gramte, with almost perfectly decom-- 
posed mica,^md felspar slightly so; from Kip- 
baasen, in Thuringia. 

'^ 53. Granite with entirely decomposed mica, 
in which, on the other hand, the felspar still re- 
tains its perfect lustre; from the Altaischan 
Mountains. 



BOMB Tin. & GWMn« f 47 

'^ Rem. This is extremely rare, as the felspar is 
by far the most subject to decay.'' 



NOME Vni. D. GNEISS. 

In this substance, as in granite, the felspac 
and the mica are chiefly affected. Karsten give^ 
the following examples ; 

HYPONOMB I. 

^^ 95. Coarse fibrous gneiss, with slightly de- 
composed felspar, but further decomposed mica ; 
from Swisserland. 

^' 96. Gneiss with entirely decomposed felspar; 
from the Isaac, near Fr^yberg. 

^* 97. Gneiss entirely decomposed, which is * 
iicarcely any longer distinguishable, except where 

« 

the quartz still retains its appropriate structure ; 
with an adhering compound of brown blende, 
martial pyrites, and some galena; from Frey- 
berg.*^ 

The last is properly a vein^stone; and rocks 
dre generally decomposed when in contact with 
metallic ores. 



1(49^ BOMAIV XX* XWCOMfOlSO. 



NOME IX. D. PrrCH-STONK 

This substance being of a very* compact and 
unctuous nature, its decomposition seems rather 
difficult. Among the volcanic specimens from 
Auvergne, in the author's cabinet, there is a 
piece of decomposed pitch^stone, which would 
be mistaken for brown iron ochre, if some parts 
did not retain their original character. 



NOME X. D. SANDSTONE. 

These glutenites, whatever be the cement, will 
discompose into sand. From the appearance of 
the rocks, in the vast sandy desarts in Africat 
and Asia, travellers have presumed that those 
prodigious extents of inert matter proceed from 
the decomposition of ranges of sandstone. Thia 
is perhaps the only decomposition which is de* 
structive of all cultivation. It was natural for 
an* Elector of Brandenburg, the lord of a sandy 
region, to inquire why God had created ^nd ?. 
While the vast and lofty chains of mountains, 
covered with perpetual snow, supply perpetual 
rivers, and perpetual fertility, tq the most dia« 



wnng art. ahd xiu £4$ 

taut regions ; those eoipires of sand present ta 
human observation no symptom of utility, but, 
on the contrai'yi daily encroach on the fertile 
vales in their vicinity. ^ 

Sandstone rock and sand, from the desarts of 
Africa. 

The same, from Aiiibia. The sand is red and 
coarse, and the decomposition would appear to 
proceed from iron ; so that a metal of the great- 
est utility may, in the field of battle, or in the 
dreary desart; become the most pernicious to the 
human race. 

Sandstone and sand, from the desart of 
Shamo. 



NOME XI. D. CLAY-SLATE. 

This is a common occurrence. Aluminous 
slate is particularly subject to decomposition. 



NOME XII. D. SAUSSURITE. 

« 

This magnesian basaltin, one ' of the pierres 
de forne of Saussure, is not only liable to a sQ« 
perficial decomposition, forming a white crust ; 
but, as it sometimes contains 'asbestos and ami- 



(^Q DOMAIN XU »BCQUfO%ES>. 

aothus^ may become rifty^ and thus split by th^ 
weather* 
Decayed Sau8surite> from the Alps, 

i 

The same, with amianthus, firom the Pyreneeii 



NOME Xin. D. MARBLE. 

Argillaceous marble, as already mentioned^ is 
peculiarly subject to decomposition, tin the 
north of England^ black marble has been ob- 
served, accompanied with a soft grey substance 
Galled rotten-stone ; but this seems rather an 
adherence than a decomposition. Rotten-stone^ 

^ > * 

though also used in polishing, must not be con- 
founded with tripoli, which seems a mixture of 
very fine clay and sand, and is only found in 
veins. 



NOME XIV. D. ALABASTER. 

In particular circumstances, this substance 
first becomes of a dull white> and then decom* 
poses into dust. 



wMu xr. o. COAL. jlSL 



NOME XV. D. COAL. 

I 

< This substance, when in contact with ^ha^ 
Itre called whin*dykes^ those singular arrects or 
uprights which sometimes intersect whole mouo- 
tains^is often observed to beiiecomposed ; having 
lost its bitumen^ and wearing the appearance of 
being charred* The Neptuaists say, that thQ 
jsjtone has absorbed the bitumen; while thci 
Plutonists affirm that the melted stone^ ejectecl 
firom beneath^ has caused the bitumen to eva^ 
porate. 

Those immense arrects are often argillaceous^ 
but more generally of a basaltic nature. They 
9f e. sometimes of prodigious extent ; one of them 
extending from Lothian through the estuary of 
the Forth into Fifeshire, a space of twelve of 
fifteen miles. It is observable, that where they 
intersect the coal^ the beds subside in this po* 
sition : 




S52 DOMAIN XI. DECOMPOSBO. 

ti^hich seems to evince that they rose from be- 
neath, having left an empty space in the direc- 
tion of their ascent» into which the superincum- 
bent bed subsided ; for if a mere rupture had 
taken place, the descent of any substance from 
above would not have altered the original levef 
of the beds. The eruptions of clay are frequent 
in American volcanoes, and may arise like sand* 
stone, from the subterranean waters, which seem 
of far more extent and influence than is gene- 
rally conceived. It ought also to be observed, 
if these arrects proceed in a northerly and south- 
erly direction, or on any point of the compass 
from S. £. to N. W. ; for such seems to be the 
common direction of chains of volcanoes, and 
of earthquakes ; as perhaps in the desiccation of 
this globe, and the contraction at the poles, rup- 
tures of different sizes took place in the shdll, 
which were afterwards filled with subterranean 
waters, and combustible materials ; while an ex- 
tenor crust was gradually formed, with a dis- 
tant resemblance of those on some morasses, con- 
sidering the horrible chasms^ beneath. It is far 
from the intention of this woilc, a mere intro- 
duction to the science, to support any system ; 
as it is of an eclectic nature, choosing the 
most authentic facts, and the most solid obser- 
vations^ from all the theories. If these ideasj 



BVVBCTB OF DBCOMPOSITIOIT. 253 

however, should appear to savour of volcanisniy 
let it be considered that we are on dangerous 
ground; for we now approach 'the volcanic 
domain. 



, The decomposition and ruin of mountain^ 
forming one of the grandest features in the his* 
tory of the earth, a few examples may be sub- 
joined ; which shall be introduced by some ob- 
servations of the greatest of petralogists, upon 
this singular and important topic. 

" Another fact, bf which I discovered the ^ Natnreof 

aeoomponoiNk 

solution by examining these granites close and 
attentively, is that of those exfoliations which I 
had observed in the upper valley. It is a fact 
known by all mineralogists, that most rocks are 
softer in the interior of mountains than at their 
external.part ; and that in the air they acquire 
a considerable degree of hardness. It hence fol- 
lows that the external part, or the edge of the 
vertical sectioiiL of a large layer of granite, ougl^t 
to harden- by contact with the air, whilst the 
interior of the same layer retains a certain de- 
gree of softness. And so long as the lower 
layers remain a little soft, the enormous weight 
<d all those that rest upon them> must in time 



254 DOMAlir XI. DSCOinttttDk! 

conipreds them. But the external parts^ faardea^ 
ed by cobtact with the air, are not susceptible 
of the same compression. They i^rast then se« 
parate, and thus form the exfoliations which are 
observable. 

^'Thisexplanation acquires the highest degree 
of probability^ when we see some of these large 
plates still adhefing> above and bdow^ to the 
layers of which they were a part, and only se^ 
parated in the middle^ where they form a kind 
of convex arch on the external side; and the 
identity of the substance, as well as the parallel 
direction of their veins with those of rocks from 
which they are separated, demonstrate that they 
have formerly been united with them/'* . 
liapid. The decomposition of these prodigious works 
of nature, the Alps, is far more rapid and in* 
cessant than might be supposed, increasing per^ 
haps in proportion to their antiquity. The fol* 
lowing grand and striking observation of Saus? 
sure, will not fail to impress the reader with this 
singular truth : ^< I do not exaggerate when I 
say that we did not pass an hour, without seeing 
or hearing large masses of rock precipitate them* 
selves, with the sound of thunder, either front 
the sides of Mont Blanc, or the Aiguille Marbr6^ 
or from the crest on which we stood."t 

• Smiss. 1748. t § S048. . . > 



EFjrsovi or obcouposjltiov. ||55 

Of the ruia of mountains^ one of the most Roin of pinnw 
tnoi^nt examples recorded is that which occa* 
sioned the melancholy fate of the town of Piura, 
by the Swiss called Pleurs, in the county of 
Chiavenna ; a handsome and commercial town, 
which was overwhelmed by the fall of Mount 
Conto, in 1618 ; when the inhabitants, in nvaa* 
ber 3430, were crushed or buried alive under the 
ruins^. The manu£e^cture of oUite, which yields 
ed to the town a revenue of 60,000 ducats, is 
said by some to have led to this disaster^ the 
quarries having been so iniprovidently conducted 
as to* undermine the mountain. But other 
writers regard it as proceeding from those na^ * 
tural causes, which have occasioned the fall of 
other, mountains, in Swisserland and other , 
countries. 

Burnet introduces his account of this melan-i 
choly event by some observations on pot-stone, 
or ollite» which are indeed materially connected 
with the subject. / * 

/ *' There is a sort of pots of stone, that is used oiuit. 
not onfy in all the kitchens here, but almost all 
Lvnbardy over, called Lavcgcj the stone feels 
oily and scaly^ so that a scale sticks to one's . 
^ngor that touches it, aud is somewhat of the 

1 

* Bounit, 01aciec9« iii. |20. 



1 

* 
I 



256^ BOMAIV XU ]IBCOMPOM». 

nature of a slate : there are but three mines of it 
known in these parts^ one near Chavennes''^/ 
another in the Valteline> and the third in the 
Grisons ; but the first is much the best. Th^y 
generally cut it in the mine round, of about a 
foot and a half diameter, and about a foot and a 
quarter thick ; and they work it in a mill, where 
the chisels that cut the stone are driven about by 
a wheel that is set a going by water, and which 
is so ordered, that he who manages the chisd^ 
very easily draws forward the wheel out of the 
course of the water. They turn off first the 
outward coat of this stone, till it is exactly 
smooth, and then they separate one pot after 
another by those small and hooked chisels ; by 
which they make a nest of pots, all one within 
another ; the outward and biggest being as big 
as an ordinary beef-pot, and the inward pot 
being no bigger than a small pipkin : these they 
arm with hooks and circles of brass, and so they 
are served by them in their kitchens. One of 
these stone*pots takes heat, and boils, sooner 
than any pot of metal ; and whereas the bottoms 
of metal-pots transmit the heat so. entirely to Ae 
liquor within, that they are not insufferably hot, 
the bottom of this stone-pot, which.* is about 

* Cbiaveaaa, 



KjrPBOTt OP ABCOMPOtlTIOW. 2^7 

twice so thick as a pot ofmetal^ burns extreme* 
ly. It never cracks, neither gives any sort of 
ta^te to the liquor that is boiled in it ; but if it 
falls to the grpand, it is very brittle ; yet this is 
repaired by pi^tching it up : for they piece their 
broken pots so close, though without any ce- 
ment^ by sewmg witt^ iron- wire the broken par^ 
eels together, that in the holes which they pierce 
with the wire there is not the least breach roade^ 
except that which the wire both makes and filj[s« 
The passage to this mine is very inconvenient ; 
for they must creep into it for near half a mile 
through a rock, that is so hard that the passage 
18 not above three feet high ; and so those that 
draw out the stones, creep all along upon their 
belly, having a candle fastened in their forehead^ 
and the stone laid on a sort of cushion made for 
It upon their hips: the stones are commonly 
two hundred weight. 

^' But having mentioned some falls of moun* 
tains in those parts^ I cannot pass by the ex-^ 
traordinary fate of the town of Pleurs, that was 
about a league from Chavennes, to the north in 
the same bottom, but oti a ground that is a little 
more raised. The town was half the bigness of 

* Rather of fragments and avalanches ; and the partial ruin ot 
QhiSLVcnnsL, in the 14th century, by the (all of a cliiF:' p. 75, 

VOL. II. S 



^Sl »MIAIir %U tfBG^tfVOItlK 



Gbav^Eines; the flumber of the itAmMuLtd wM 
tboat two and twenty bundfred peiwnsy but it 
Was much more nobly built i for besides the 
great palace of the Francken, that cost some 
Inillfons^ there were many other palaces that 
were built by several rich fectcM^i bc%h of NKIatt 
and the other parts of Italy, who liked the 
mtuation and air^ as well as the freedom of the 
government of this place ; so they used to come 
hither during the heats, and here they gave 
themselves alt the indulgences that a vast wealth 
oould famfsh. By one of the palaces that was 
II little distant from the town, which was not 
Overwhelmed with it, one may judge of the rest« 
It was an outhouse of the family of the Francken, 
and yet it may compare with many palaces in 
Italy; and certainly house and gardens could 
not cost so little ^s one hundred thousand crowns. 
The voluptuousness of this place became very 
crying -, and Madame de Salis told me, that she 
had beard her mother often relate some passages 
of a protestant minister's sermons, that preached 
in a little church, which those of that religion 
had there, and warned them often of the terrible 
judgments of God which were hanging over their 
heads, and that he believed would suddenly 
break out upoti them. On the 25th of August, 
1618^ an inhabitant came and told them to be 



gone^ fbr he saw the mountains denting ; but 
be was laughed at for bis pains. He had a 
daughter^ trhom he persuaded to leaye all^ and 
go with him ; but when she was gone out of the 
town with him, she called to mind that she had 
not locked the door of a room, in which she had 
some things of Value ; and so she went back to 
do that, and was buried with the rest : for at 
the hour of supper the hill fell down, and buried 
the town and all the inhabitants, so that not one 
perscm escaped. The fall of the mountain did 
90 fill the channel of the river, that the first 
news those of Chavennes bad of it, was hj the 
failing of their river ; for three or four hours 
there came not a drop of water, but the riVer 
wrought for itself a new course, and returned to 
them. I could hear no particular character of 
the man who escaped, so I must leave the secret 
reason of so singular a preservation to the great 
discovery at the last day, of those steps of 
Divine Providence, that are now so unaccount- 
able. Some of the family of the Francken got 
some miners to work under ground, to find out 
the wealth that was buried in their palace ; for 
besides their plate and furniture, there was great 
store of cash and many jewels in the house. 
The miners pretended they could find nothing ; 
but they went to their country of Tyrol, and 

* 2 



260 OOMAIK XI. DSC0MCO8BO. 

built fine houses^ and a great wealth appeared^ 
of which no. other visible account could be 
given but this> that they had found son^e of that 
treasure." 

Mr. Cox:e, in his interesting des.criptiou of 
Swisserlandy aft^r a short account of this events 
adds the following observations : , 

" I walked over the spot where Pleurs was 
built : parts of the ancient walls^ and the ruina 
of a country-house, which belonged to the 
Franchi, the richest family in the place, are the 
only remains of its former existence ; and these 
would not be noticed by a passenger. A pea- 
sant, who has a cottage close to the ruins, point* 
ed out to me every place, as it had been ex- 
plained to him by his grandfather. He showed 
me where stood the churches and prinpip^l 
houses, the channel through which the river 
then flowed, and where the bridge was con- 
structed. He informed me, that in digging, se- 
veral dead bodies had been found ; particularly 
the bones of a priest, covered with shreds of 
garments, which indicated that he was employed 
in divine service when the rock overwhelmed the 
town. Household utensils are frequently dug 
up : the other day, several corpses were disco- 
vered, and on the finger-bone of one were a silver 
and two gold rings. Vineyards, chesnut-trees. 



1714. 



BFPBCT8 OF DBCOIfVOSIflOir. f|0X 

and houses, cover the spot where this unfbrtttnate 
town was once situated/' 

In 1714, a great part of the mountain Dia- l>i*^i^ 
bleret fell. It was on the 23d of September, 
between two and three o'clock in the afternoon, 
and during the calmest weather, that the sum- 
mit of this mountain fell in an instant, and 
covered more than a league of fertile land. Of 
140 huts there only remained 40 s and where 
the others stood, there is at present a bed of 
stones, about SO yards in thickness. Four tor- 
rents were stopped, or changed their courses, 
and now terminate in lakes. There perished 
under the ruins of this mountain, eighteen per- 
sons, near one hundred cattle, with a great 
number of sheep, goats, and swine. Those who 
saw this disaster, say that it haf^ned in a mo- 
ment i and at the same time there rose whirling 
clouds of dust, which darkened the air like a 
sudden fall of night, and so much covered the 
neighbouring pasturages that they were obliged to 
withdraw the cattle. Even the adjacent moun- 
tains were wounded by the faU, which lasted 
for twenty*four hours. Some pretended that fire 
and smoke were seen ; but the former arose from 
the collision of the siliceous fragments, and the 
pretended smoke was only dust ; while the smell 
of sulphur arose from the pyrites. 



Tolthte account of IioBe«t Groan^^ Bourrit 
has added> as usuaU some pioturesqiue (pirQum- 
' • stance^* . - 

«^ This rain happeadd m tbe^ 23fl Qf $ept«mr 
ber i the weather .was caloii th0 sky doar ; the 
cattle were feeding peaceably under the shadow, 
pf th^se rockp; the goats^ 9beep, and iBXjfim 
frere .playing .in the pasture. The afaepberds 
m4 sh0pher^ses were diverting themselvies 
wUh innocent gAmes ; nothing happened to foro^ 
warn them. <i£ their :terrihle fate» when the 
mountain suddenly fell^ and buried under its 
ruins shepherds^ cattle, pasturages,, and huts. 
The fragments of the codk:s, which extended fior 
two leagues ; ^ the smoke, which covered the sky 
with thick darkness ; and the horrid noise, which 
the . neighbouring mountains increased by deep 
9nd repeated echoes ; all seemed to. announof 
total Tuin to the vicinity. The surprise, the 
terror, the lamentable outcries of men and quae 
drupedsr the disordered and tumultuous flight of 
birds, spread the alarm to a distance.; and all 
fled from places which they could no longer 
know, and where they could not hope for safety. 
This terrible ruin destroyed considerable woodsy 
which served as ramparts against the avalimches 
of snow, at present so dreadful and destructive. 
The rivulets which came from the mountain Imve 



hoA thfir course^ and no longer eiciMs §o tlwt 
the pastuiBges are become deaertsj wliicfa <mljr 
remittd. die spectator of this suddea irwmJ* * 

This author also in^onass us, liiai;s at the %\m^ 
of the earthquake at U^oUt many moontaav 
were seen to shake in the Vallais, which hM ve^ 
mained subject to earthquakes since that period ; 
Md the town of Brigue Buffered considerable da«» 
mage. But in 17^ if another mouotiAn ftU^ 
and the account oi thiB disastw shaU :be gif en in 
ihe words of SauBSure ; aftor premising that <hts 
aouDtain was situated not fiur from Piassy^ ber 
iween Sallenches and Servoz. 

*^ Near this summit was rituatad a tnountifiiii. Monntaio new 

Serrosi 175lf 

which fell ki 1751, with so dreadful 9 ttoise, and 
j^o thick and dwk a dust, that many people be- 
lie?ed that the world was at beu end. Thts.black 
<dust passed for sm^e^ ejes, distracted widi 
lear^ saw flames in the mkkt of tke whirling 
jttoke : uid intelligence was received at Turin^ 
ihat a tecrible volcano had bunt forth in ihe 
miAat of these mountaiosy so that.tlie long aent 
« cdebrated naturalist, Vitaliano Dooati, to ve- 
rify that Kport He came with great diligence, 
before the rocks had completely fallen, so that 

« 

^ G&ioaner, Glac. de Sotie^ Vku, 1770> 4to. p. 138. Bonrrft, 
iLqs. 



254 bOMAIW XI. DECOMK^SSD. • 

be was witness of a part of , that ev^t. He 
gave the king a memoir of his obsenratioiis : and 
a brief account is contained in a letter to one of 
his friends, of which I possess the original, dated 
15th Oetober, 175 1, and of which a translation 
follows: • 

* I left Turin on the I6th July, and only re- 
turned within these few days. I was in the 
valley of Aosta ; and I was in hopes of being in 
Venice in September and October. But I was 
obliged to turn back, and make a tour of 250 
leagues in the mountains, to observe the pre- 
tended new volcano, according to an order 
which I received from his majesty. I confess, 
that though I doubted the truth of the fact» 
•nevertheless^ hoping that I had deceived myself, 
I hurried with extreme pleasure to observe so 
extraordinary a phenomenon. After having 
travelled four days and two nights without halt- 
ing, I came in front of a mountain all covered 
with smoke; and from which were incessantly 
detached, by day and by night, large masses of 
stone, with a noise perfectly like that of thun- 
der, or of a large battery of cannon ; but still 
louder and more terrible. The peasants had all 
retired from the vicinity ; and did not dare to 
look, at this ruin> but at the distance of two 
iniles, and even farther. All the neighbouring 



y 



B^VlCTlB OF l>BOOilP68ITIO«r« 265 

Aelds were covered with a dust^much resembling 
asbes; and in some spots ihis dust had been 
carried by the winds to the distance of five 
leagues. All said that they had seen, at inter^ 
vak^ a smoke which was red during the day, 
and accompanied with flames at night. These 
^observations led people to believe that it was a 
volcano. But I examined the pretended ashe^^ 
and only found a dust composed of brayed mar- 
ble: I Attentively observed the smoke, and 
neither perceived flames, nor any smell of sul- 
phur ; nor did the rivulets, nor fountains, which 
I examined with care, present the least appear- 
ance of sulphuric matter. Thus persuaded, I 
-entered into the smoke, and, though quite alone, 
went to the brink of the abyss, where I saw a 
large rock dart into that abyss, and observed 
that the smoke was only dust, raised by the fall 
of the rocks ; the cause of which I soon after 
sought for and discovered. I saw that a great 
part of the mountain, situated above that which 
had fallen, was composed of earth and stones, 
not disposed in beds, but confusedly heaped to- 
gether. I thus perceived that the mountain had 
been subject to similar falls ; at the end of which 
thelai^e rock, which fell this year, had remain- 
ed without a support, and with a considerable 
projection. This rock was composed of hort- 



4{^ POUUM WiU 0nWU9Q$M9^ 

TOOtal bedsj of which die two lower were of 
alat^i or rather of fragile schistose stone« and of 
litlje consistency; while the two beds beneath 
thes^ were of a marUe, like that of Porto Venere^ 
but full of rifts which crossed the beds. Tte 
fifth bed was wholly composed of slate* in vertt^ 
cal learesy entirely disanited ; and this bed fon»- 
ed aU the upper part of the fallen monntaio. 
Upon the same level summit there were three 
laikes« of which the waters penetrated constat/ 
by the fissures of the beds» separated them, and 
4ecQnposed their supports. The snow, which 
4jits year had follen in Savoy io so great abirn- 
dabce as had newer been seen in the mcasiory of 
jnad» having increased the effort^ all these w^ 
ters reunited produced the i&U of three miUmis 
of cubic falhbms of rock ; » mass suffici^M: 4d 
form a large mountain. In Abe aarrsttve wfaiefa 
X have written of the fall of this Eio»otaisi, and 
which I jseat to has mi^esty^ with a tiew of ih(e 
mDn«taAn» I have given a mm? detailed account 
of the cause and efiect of this ruisi^ and I fore- 
told that it would cease in a flhort tiaie» as has 
actually happened; ao that tiius I have eisto* 
guished a volcBDa.'' 

Sanssnre proceeds to infonn us» that thertuos 
of this mouBtain mre situated io the north-east 
of the village of Senrocz. Bead^ the saiidstone 



BrrSCT8 OP DBC0XP081TI0H. 



267 



1806. 



already described*» Saussure observed rocks of 
grey marble^ and fragments of slate. 

Sach are some of the most remarkable exam- Ro^enbof^ 
pies of this phenomenon. In 1806, the moun- 
tain of Rosberg, or Rosenberg, near the town of 
Arth, fell down, and buried a considerable tract 
of country, with some inhabitants. A detailed 
account of this event was published at Paris, 
with three plates, representing, 1. the town of 
Arth, the neighbouring country, and the profile 
of the ruin ; 2. the same scene in front, with the 
extent of the fall ; 3. the lake and tower of 
LawertSf with Roggiberg and Rosenbergf* 

* Dom. 11. Modexur* 

t Dermere relation da trisU i^sasire, caus/par TehouUment if cme 
parlie du Roggtberg, et du Rosberg i de trente pages d*etendue, 
meeompagmio de troh graoures^ propremetd terminiei en noir, de 10 
poueee de haut, $url5de large. Chez Fillequin, march, d^esiampes, 
grande amr du Tnhunat, No. SO. f^Jr. 

La premiere rtpreemUe le heau hourg d^Arth, Us campagnee qtn 
favomnenif ei le profil du Tehomlemeni: La teeonde, Timmem^ 
ttdqfaifa§9 et iruie Umhtam, £%ne pariie dee haUtuu, de la naUde 
dArtkt et feboukmeni mi deface. La ttememti leJacet la tour d$ 
Lawerts, le Roggiberg, et le Rosberg. 



DOMAIN XII. 
VOLCANia 



The volcanic rocks may be said, with the 
Gennan miQeralogists, to be of the most 
modem formation, as every new eruption 
of about one hundred and fifty volcanoes 
'scattered over the face of the globe, must 
produce new rocks of this description. 
That there are also volcanoes at the bottom 



SOMAIH XII. VOLCANIC. £69 



eruptions of volcanoes, must lie at an im- 
mense depth beneath the crust of the earth. 
This position may be argued, 1. from the 
surprising extent of earthquakes, felt from 
Lisbon to Scotland, a space of 15 degrees, 
or about 1000 British miles. 2. From the 
prodigious quantity of matter ejected in 
the course of ages ; from the comparatively 
small craters of Etna, for example, whole 
mountains, nay territories have issued; 
which, if drawn from a space near the 
surface, the mountain must long since have 
sunk into its own abysses. 3. From the 
nature of the lava, which, in some in- 
stances, has burst through the superincum- 



^^Q DOMAZM XII. VO&CAKICU 

bent masses of granite, itself regarded as 
the fundamental rock. 
Candour As it is foreign to the nature of this work 
to examine with <much attention the the* 
ones of volcanoes, it shall only be observed 
that the French authors, in treating the 
origin of basaltin and amygdalite, seem to 
be rather too much attached to the volcanic 
influence ; yet we, on the other hand, seem 
to be too violently prejudiced against the 
admission of that influence. Prejudice, 
on either side, is not only ridiculous, as 
the subject is of no importance to human 
life or happiness, but as a direct contra* 
diction to the very spirit and nature of phi- 
losophy, which ought to examine any topic 
with coniplete candour and impartiality; 
nay, a writer who means sincerely to serve 
the sacred cause of truth, which must in 
the end ever be victorious, would rather, 
iot a season, support an opinion the most 
opposite to prejudice, that the light may as 
usual be struck out by the collision of con- 
tending powers. 
Many extinct When wc considcT the great number of 



VOtfASk XII. VOLCAMIC. S7i 

volcanoes that are still actire on that third 
part of our planet which consists of land, 
is it not most rational to suppose that many 
may have become extinct ? Strabo informs 
us, that Vesuvius had been a volcano at a 
remote period j while its first emption is 
commonly ascribed to the reign of Titus, 
»ear a century after the time of that author*. 
The volcanoes of Auvergne *se€m to have 
been relumed for a short period, in the 
time of Sidonius Apollinaris, whose ctil^ 
mina can scarcely be applied except to the 
summits of mountains ; for the tops of 

* Lib. V. This remarkable passage amy be thus translated : 

** Here arises the mountain of Vesuvius, inhabited through all its 
^licious iields^ the summit alone excepted, which spreads into a 
barren plain^ displaying ashes and deep caverns Ibrmed of burnt 
lock, as the colour indicates, and abrasions by fire 3 whence it may 
be conjectured that this mountain was formerly in a state of efBa- 
gration and presenled fieiy craters, which became exttnguishel 
when the materials were exhausted*** He proceeds to state, that 
Ae fields near Etna were equally fertile. The streets of Hercu- * 
Isoeom were pored with lava« 

See also, Strabo, lib. i. p. 158. edit. Siebenkees, for a volcano^ 
aeon extinct, near Methone, which ejected a hill near a mile in 
height, and rocks like towers. 

Pindar describes Etna, which is unmentloned by Homer, a proof 
that his geographical knowledge did not extencj as far as Sicily, and 
that the received interpretations are fklse. 



g'^^ DOMAIN XII. VOLOANIC. 

hotiises would be foreign to his emphatic 
and alarming description. Auvergne alone 
has indeed convinced every Neptunist, who 
has visited that interesting country, tha( 
volcanoes may become extinct ; and may, 
perhaps, again surprise the unbeliever with 
an unexpected appearance. Tlie wonder-r 
ful volcano of Jorullo, in New Spain, burst 
out about half a century ago, in the midst 
of a fertile and luxuriant plain ; but, as 
has been observed, in the precise line of 
direction of the other volcanoes in thai 
pountry ; whence it has been argued, that 
duuDM. there is a chasm, at an amazing depth, 
filled with subterranean water and combus- 
tible materials. For the American vol- 
canoes are generally very distant from the 
sea*, and their eruptions of mud can only 
be imputed to subterranean waters, often 
, very extensive ; as is bbserved from digging 
wells in the north of Italy, near twenty 
miles around Modena, where, on arriving 

* Even those of the Andes are from eighty to one hundred miles ; 
so that a late writer is much mistaken when he supposes them near 
the oeean^ and influenced by sea-water instead of subterraneaa 
lakes. 



flit a ccsrtain crust, the water gashes, out 
with prodigious violence. If this vast 
chasm, therefore, be covered with such a 
lasting shell of fertile land, it is easy to 
conceive the existence of similar cavities in 
many parts of this globe. For we are not 
ta imagine that the immense mass which 
forms the nucleus,, and which from ito 
gravity would appear ^Ov be iron,^ pxesents 
a uniform surface; but^may, on the con«> 
trary, bear fissures deeper, than the ocean, 
and asperities or precipices higher than 
mountains. Hence the grand observation 
of Saussure, his refiniiements*^ may be coo- 
stmed into a subsidence of .^^e beds fttonfs 
extremity, owing to . irregularities on . thp 
surface .of the nucleus, ^nd; whidi of cpursp 
elevated them at the other extremity ; whilp 
the secondary rocks, the lev^ or horizontal 
of Werner, finding^ tbe^ asperities already 

• .'** Examiner en g^n^nl si le» couches presentent des indices de 
sCNileVements, oa de lefotdements tiolents, qui aient chang^ leor 
ntoilion primitive ; on si/ mx pontiim t^usj* e«. lef . rfdnsie«)qpjts 
n{imt des coaches, peurent s*espli^uer pw de sim^k^ tfutsements** 
§0314. 

rohi II. t 



274 



AaVAlV sir. TOLCAVtC. 



filled, of course retain their regular form- 
ation. 

Biit if^ with Ddlomieu, we conceive that 
thisu planet only presents a shell spresid 
over a fluid centre, it would be difficult to 

explain why this central lava should only 

• ••■•»• 

bur»t forth in particular spots and direc- 
tions ; for it might equally appear in et^ry 
portion of the glbbe. . Theories, which 
only afford sublime speculations on the 

vast varieties of nature, and the infinite 

_ « 

power of the ineffaUe Creator, cannot be 
greatiy blamed, jeven when they So not 
lead to inccmtestible condusions ; and it is 
lioped that an inference arising ftom the 
preceding considerations may be hazarded ; 
'Basndy, that volcanoes owe their o^n to 
fissures, more or less extensive, in the very 
nudeus of our planet; and that th^se fis- 
«ures always remaining, the causes of erup-^ 
tion may be withdrawn or renewed. Thia 
theoiy, jnight reconcile iQpst of the doc- 
trines on the subject, except the puerile 
ideas c^ those Wemerians who have never 
visited volcanic countries, and who impute 



I>01IA1H XII. VOLCANIC* ^^^ 

these wonderful efforts of nature to a few 
beds of coal ! But coal or bitumen would 
easily be traced in the currents of lava, 
while no such appearance has ever struck 
the most attentive and rigid observers ; and 
a large bed of coal, near Dysert, has been 
on fire since the days of Buchanan, the 
poet, without even the mockery of a vol* 
cano. An. idea, which tends to degrade 
the power and magnificence of nature, can 
never be true ; and, when we seriously re- 
flect on the daily circumvolution of this 
planet, it is impossible to find a greater 
miracle. In complicated scenes there must 
be complicated causes ; but does not the 
grand exhibition of volcanoes arise from 
natural gunpowder?* 

* The common subterranean noise of Cotopacsi^ may be heard at 
a distance of the space between Vesuvius and Dijon, hi Burgundy, 
acooiding to Humboldt: andBouguer* p* Izvi, infiirms pa that the 
^ame volcano has thrown stones, of 8 or 9 feet in diameter, to the 
distance of 9 miles. 

> Werner seems not to have formed the most distant idea of atd* 
cano i and his paeodo-volcanoes are much beneath even that name, 
haying scarcely a fiunt resemblance of a volcano. 

According to Brochant, ii. 63d, one eruption of Etna oovered a 
space .of more iban 50 leagues inHnicnity With a bed of Tolcanic sand 
12 feet thick. 

T S 



276 SOlffAlM Zll. yOLCAKtC* 

The existence of such chasms being once 
admitted, it would be easy to account whj 

BaMit basalt always appears in volcanic coun* 
tries ; since, even on the supposition o^ the 
French mineralogists, particularly Patrin, 
these chasms must have supplied volcanic 
materials, under the primeval waters, or 
what may be called a state of chads ; for 
Patrin supposes that basaltin, compact or 
columnar, but especially the latter, may 
be the produce of submarine volcanoes, 
the matter being suddetkly congealed, and 
brought to a most compact form by the 
prodigious pressure of the ocean. Dau- 
buisson, a rigid and determined Neptunist, 
after visiting Auvergne, was inclined to 
suppose, as already mentioned, that the 
basaltin on the summits of the Germaa 
mountains was a volcanic remain of incon- 
ceivable antiquity. Beuss also concluded 

Banitie that the basaltic summits of Bohemia were 
only fragments of a mass, which had once 
clothed a prodigious territory. In like 
manner, caps of mountains sonietimes pres 
sent masses of sandstone, or limestonet 



SOMAIK XII. TOLCAMie. 



«77 



while none exist in the adjacent country. 
Whether this effect could be produced by 
currents at the bottom of the primeval 
waters (and similar currents continue to be 
observed in many seas), which, by their 
continual action, abraded the lower parts, 
without reaching the summits of these then 
submarine hills; or from whatever other 
cause this effect may have proceeded, must 
for ever remain among . the inscrutable se- 
crets of nature, which despise the puny 
efforts of human intellect. Perhaps it may 
simply arise from the circumstance that 
these portions, sometimes from their posi« 
tion, and sometimes from internal causes, 
may have beea harder than the rest of the 
mass, and thus have remained like some 
large fragments of granite, after the softer 
parts had wasted away. However this be, 
we must never, in geological discussions, 
forget the amazing power of time, which 
enables the water to destroy the hardest 
rocks ; and which, though important in the 
short period of human life, may be said to 
be .nothing, in the eternity of Him, with 



Ji78 wyukivf )au ■ ▼oioANits. 

whom a thousand age» are but as one in- 
stant. 

Bffecis of In general, the effect of fiire only is con« 
sidered in volcanoes ; but the curious vol* 
cano of mud in Sicily, and the muddy 
eruptions of the Andes, should excite more 
attention to the agency of water. If we 
conceive the volcanic chasms, containing, 
as already mentioned, reservoirs of water, 
as well as of in&ammable substances, to 
be in the nucleus of the globe ; and that 
nucleus to consist of iron, mingled at least 
superficially with its usual attendant' silex, 
the ferruginous nature of lava can easily be 
explained, as arising from an abrasion of 
the nucleus by the water. For, passing 
the minuter appearances, which only excite 
curiosity, and are exceptions, not rules; 

Iron and riiM. all lavas may be said to consist of iron and 
silex ; the most common being the black, 
of melted siderite ; while the others, of a 
grey colour, have a base of silex in the 
Febpar, form of fclsito. But fclspar is a name of 
far too general acceptation ; and may pro- 
bably, in the progress of mineralogy, be 



divided into six or more denominations, to 
be determined by fiiture analyses : for its 
extent and importance are prodigious, con- 
stituting two-thirds of granitic mountains, 
and appearing in many other forms, which 
seem to indicate a substantial diSerence in 
the siliceous rocks, now included under the 
yague name of felspar. 

These introductory observations have i^m, 
thus conducted us to the more immediate 
object of this work : the consideration of 

ft 

the lavas themselves. 

The ex^tence of compact lava, forms CMqMetkva. 
one of the most curious questions between 
the Volcanists and the Neptunists. In 
strict impartiality, thie observations of Mn 
Xlirwan, the chief defender t)f the ' Nep* 
tunian system, shall be admitted at full 
length, more especially as they may lead 
to very important observations. 

*^ By compact lavaj volcanic writers de- ^^J^SSH^ 
note an' earthy substance, which, after 
liavii^ been fused, but not vitrified, be- 
OHnes, on cooling, compact, close, and 
Bolid* 



'J280 MlCAIV XZI. TOLCAHie. 

** Whether this degree of solidity is such 
as totally to exclude that evidently porous 
and cavernous structure, which cellular 
lava presents, is not perfectly agreed 
upon. 

" Those who are guided by observation 
on modern and undisputed ' volcanic ton- 
rents, allow that no lava absoliitely conr- 
pact, and destitute of pores in an extent 
of more than a few square inches, is ever 
found. Thus Mr. * Bergman^ defines com- 
pact lavas to be ^ those which, though not 
absolutely destitute' of cavities, yet con* 
tain so few, that they may be cut into 
slabs with an almost entire surface, and 
polished like' marble,' S Bergm. p. 201. 
To ' this definition, M. Dolomieu, in his 
notes on Bergman's dissertation^ makes no 
objection ; from which we may conclude, 
* that in a small extent,* such as that of 
common marble slabs, they never exhibit 
an uninterrupted surface. This last inen^ 
tioned philosopher, indeed, having tinftfi^ 
tunately wished to comprehend, in his de< 

finitioo of compact lava, stony massei^ not 



found in modem and undisputed beds of 
lava, but in supposed apeient currents, 
found himself much embarrassed : ^ there 
is/ says be, * such uncertainty in the cha- 
racters of compact lava, that independent* 
ly of local circumstances, the most expe- 
rienced eye may be deceived*/ Yet these 
circumstances, not properly attended to, 
are those which have seduced him into the 
most palpable mistakes* 

^^ Gioeni, though in many instances mis* 
led by Dolomieu, yet acknowledges that 
lava, so compact as to be totally destitute 
of pores, is not to be found. Litbolog, 
•Vesuv. p. 85-f-. Padre Torre, who, inde* 
pendently of any system, has candidly and 
impartially examined the products of Ve- 
suvius, expressly denies, the existence, of 
lava destitute of pores ; none other but the 
porous being found of modem. date|. 
cGaleam,Jn hi& • catalogue of the lava^ of 
-Vesuvius, drawn up in 1772f hardly men^ 

' ^ Isks Ponces. 171t « 

t (It is 157 ; but pot ezpressly.;^?.) 
} Ponoes^ 174, 



281 IK>lCAlir XII* TOICAWSC 

tions any coTnp»p% l^YOS, . Gioeqi, m hit 
catalogue, entirely. omits this distinction; 
and M..DolQnueu acknowledges, that not 
a single spepimen .of compact lava is to be 
found in the. cabins of Prince Bkcari. 

^^ Those, on the other hand, who, guided 
by system, bestow the name of lava on 
stony masses n^hich. they suppose to have 
anciently.flowed>.either from real still sub- 
sisting, or imaginary. ancient. extinct, vol- 
canoes,.find compact lava entirely destitute 
of pQff»» .veiy jicarce ^i^xleed in the sy p- 
posed currents horn modem^^ but in great 
plenty in those which they ascribe to their 
fictitious, volcanoes now extinct, as well as 
in the very bowels of .those volcanoes. 

^ Gioeni afkef telling us, from Dolomieu, 
that compact lava occupies the ce^ptre of 
the beds of lava, and porous lava the upper 
part, acknowledges that this gradation sel« 
dom takes place : ^ few, however,' says he, 
y are the visible currents of lava oh Vesu« 
yius, in which we meet this gradation/ It 
seems he should rather have said, none; 
for, some lines after, he tells us, ^ that mo- 



OOXAIlt Xtf. TOXJCAVIQi 283 

dem Tolcanoes bavd lost tlie power of pixH 
ducing anyV The detached < masses that 
pass for compact lava^ be acknowledges to 
have been ejected in their solid form, by 
the explosive powor of the volcano; and 
consequentl J they are not real lavas, but 
rather natural stonesv torn Irom the'sides 
of the mountain-f*. M. I>olomiett tells xm^ 
that compact lavas are stones, which, alter 
having been melted, reassimie their natural 
state and appeaiance;' without any. change 
in their external or internal prc^icalMS^ or 
scarce any change:];'; and that some are 
perfectly compact (that is, destitute . of 
pores) ; namely, those that are buried un^ 
der, not other lava»,* but under an entye 
and immense volcano §; he therefi»re gives 
up the idea of finding these, not only in 
the beds of modern, but even in those of 
extinct ancient volcanoes. Hence he tells 
us, that they are much more conunon in 



♦ lithol. VcBuv. p, 47. 

t Ibid. 61. 

X Dei prodotti VdcaiL p. iG^. Ponoes, I70, &o» 

I Ibid, 179* 



264 BOHAIir XII. TOLCAMXCU 

extinct volcanoes ; and that in Etna thej 
do not constitute the one thousandth part 
of the whole ; whereas, in Vivarois and 
Auvergne, they form whole mountains. 
Now most of these ancient volcanoes of the 
Vivarois, appear to me, and many others, 
to be mere creatures of imagination ; and 
consequently, until the substances they 
contain are proved to have been in fusion, 
no definition, grounded on the appear* 
ances of these substances, can pass for 
that of real compact lava*. 

" In beds, however, of real undisputed 
lava, some parts are found, that having 
been pressed by the superincumbent weight, 
are more compact than common porous 
lava, and these, comparatively to the for- 
mer, may be called compact ; but scarcely 
more than a few squai:e inches of their sub- 
stance is destitute of visible pores. 

** Their colour is brown, yellowish, reddish 
brown, bluish, or black, more rarely grey. 
Their lustre 0,1. Transparency 0,1. 

* (See, on the oontniy, the remarks of another Neptoiiift» Daa« 
« in Dom. I-^P.) 



IHyMAlir XII. TOLCAVIO* 285 

. ^ Their firactute, earthy » or fine spliiH 
t^, more rarely foliated^ and pretents 
small internal pores, if of sufficient siee, 
in some part of their substance. 
. *^ Hardness, from 7 to 9* Specific gra^ 
vity, 2,75 to 2,88. • 

^^ Much circumspection id requisite, in 
framing a description of compact lava, firom 
h view of the specimens brought to us from 
volcanic; countries ; as they are all collect- 
ed by persons who take indiscriminately 
from real, and from supposed, volcanic cur* 
rents, even. from mountains in which no 
volcano ever existed. 

^^ To form a true idea of these laras, we 
should attend to the following circum* 

stances: 

*^ 1st 'Ebat the heat of most volcanoes 
(I exclude those that for the most part 
produce only vitrified substances) seldom 
Ireaches 100 degrees of Wedgewooci ; the 
proof of which is, that almost all real lavas, 
whether cellular or compact, are vitrifiable 
at that degree. Since, therefore, they were 
not vitrified in the volcano, it is plain that 



2gg OOMAtW XII. T(WiCA]ll€. 

in it they did not attain that d^ree ; 90 or 
95 degrees may then be assumed as the 
average heat of most volcanoes. 

^^ 2d. In this heat, many stones of the 
argillaceous genus,' as ta^ps^ hornblendes, 
and argillites, undergd a change ; for they 
alttf their colour^ become porous, ^.ssume 
h pwcelain graiur uid consequently begin 
to vifcrify, as I hav€ Ibund on repeated 
trials ; but they Beverflow in tins heat, nor 
consequently i&rm alava ; but Intumen will 
flow in thb heat, and even in one much 
inferior^ and be ^decomposed. If, there* 
fore, the argillaceous stones be mixed nirith, 
aikdr drenched in bitumen, they will be 
sofibened llydt^4Mi^ flow with it ; and where 
the air, erapting both fix>m them «nd the 
decomposing 4)ttumeB^ has -most liberty to 
escape, it^ wifl lumify, bmrst through the 
liquid'^ Etiass^ and form cellular lava; but 
where it is more compressed, less of it will 
Ise disengaged^ and the lava will be com- 
pact, 'Mid resemble in some degree the ori- 
ginal stone of which it is formed. 
' ^< Sd. Stones of the siliceous genus un- 



dergo no change in this heat, not even 
schorls or felspars ; and hence, though imh 
mersed in the fiery torrent, they cannot 
with propriety be called lavas ; as they are 

i* • V ■ 

even softehed by'tiSe mixture of bitu- 

men, as stones of the lur^l&Ctous genus 
aw. " '" " ■ "' ■■ 

' ** Between siUeeoas said " ntgillsioebus 
stdnes'thfere Are nian;^ gradatidlis, and t»- 
•noiii lttixtui«s, "klahh nMM occasion cor- 
responding varieties in the effects which 
heat, 'Stid vayioQS 6f^eif ciitninl&tances, maj 
'produce. It i£( sufficient here to' establish 
the'priiidple& Ott whidv most df them may 
be ekpteln^. ' Cdm{>act lavas abound in 
hetero^icyas sbBsfftbcite, t(1iibb«hiive either 
liot been fused; tx ottly partiftUy fused, or 
scorehfed; ot dbd6mpoded' by h^t, as ^- 
qpar, 8clioi)s; gSfnefs,' zedlitfes^ ftc.' Every 
volcano 'hSea*'s6me that arb' pl^&iiliar to it. 
!l£us the TaVii§' of V^uVins itiSiinid m that 
caU^ Wmtfe gahiet, ai£d ^liichl call Ve- 
flpuvian ; thosig of Etna alxiiihii in felspar, 
■&c. 
~** ^enoe Winttytekclttde!!6m the rank 



4|^ DOMAIN XII* TOIiOAMIO. 

of kvas^ all stones which do not appearr 
either from their external characters or 
local circumstances, ever to have been 
softened by heat ; and consequently aU 
those detached pieces which are ejected at 
the beginning of an eruption without fusion, 
and many others which volcanic collectors 
enumerate among compact lavas, merely 
from having found them in the vicinity of 
volcanoes. Thofr M. Dolomieu, Lipari 85, 
reckons among volcanic stones one, in the 
interior of which he distinctly perceived ft 
leaf of sea*weed. Few indeed are the 
stones contained in his catalogue, wUck 
can be deemed really volcanic : and p« 70t 
of the same treatise, he tells us, that thfe 
lava which burst from the sides of Etna, ia 
.l669f had for its basis a granite^ no way 
altered; but when he expressly treats of 
the products of Etna, he tells us, L'Etnm 
paroit n* avoir jamais traitile granite^ The 
mistakes of this great man, for such I cer- 
tainly hold him, have had so wide a spread, 
and have misled so many who have not 
had an opportunity of viewing volcanic 



DOMAIN Zli. VOLCANIC. £89 

countries, that I feel myself necessitated 
to detect them ; a liberty which, I am per- 
suaded, his candour and love of truth will 
readily induce him to excuse. 

"• All real lavas, except those of the vi- 
treous kind, affect the magnetic needle, 
unless the iron they contain be much oxy- 
genated, as it often is in those of a red 
colour ; but even these are frequently mag- 
netic, by reason of the schorls embodied 
in them. 

" The component ingredients of lavas 
are various, according to the nature pf the 
original stones, and the accidents they 
meet with in the liquified state. M. Do- 
lomieu found them to contain irom 40 to 
60 per cent, of silex, from 16 to 3 of ma^ 
nesia, from 5 to 1 of lime, and from 6 to 
25 of iron. Ponces, 184/'* 

These reflections are certainly cogent, 
and worthy of the sagacious author, who 
has rendered great services to the science : 

* Kirwan, Min. i. 404. 
VOL. II, V 



IJI^ BbltAtH til. rotCAHlC 

hot tntist We, in the modem spirit of in« 
gratitiide^ not (even of 

Th* unwilling gratitude of base mankind, 

ibrgei the state of mineralogy at the time 

ht wrote, because superior illuminatioii 

has since been thrown on many topics* 

oter On tlie other side^ the worii:s of Dolomieu 

opnuooi. 

on the Lipari Islands, on those called 
Ponceis, near the Gulf of Naples^ and on 
Doiomiea the volcanic productions of Etna, were 
written before he had attained much expe* 
lictice in Udmlogy. Tliis trath lamentably 
Wppfeat% fh)m the latter production, where 
two o^ three passages demonstrate that he 
Vlid hot even know what granite is*; jdt 
we lane toM that exact nomenclature, and 
th6 precise knowledge c^ particular stones, 
are not necessary in geology ; which is as 



^ Inp.£01» he talltuft thai the 6ate of granite, oomiitidr 
•ive felspar v and p. S57> he mistook a mixture of schorl, febpar, 
'and chiysoKte, wt k gratnite. E/jual tftMA may he IbMid in many 
books of geology $ a study which totally depends on a previous 
acquaintance with petralogy and lithology. Dolomieu was a mill* 
iary man, who at an advanced age entered on this difficult study. 



DOMAIN XII. VOLCANIC. ^91 

much as to say, that Botany can only be 
studied in the roots, or Zoology from the 
legs of animals ; that History may be stu<^ 
died in a book of chronology ; or that, in 
short, any science may be attained with 
complete inattention to its chief objects. 
For a laborious study, and even the most 
nice discrimination of lithologic character- 
istics, is indispensable ; otherwise the key- 
stone may happen to be the weakest, and 
the whole edifice may sink in ruins. The 
treatises of Dolomieu on different rocks, 
published some years after in the Journal 
de Physique, though tedious, prolix, and 
ill-digested, like all his writings, are the 
best and most scientific of his productions. 
But, on the other hand, our celebrated 
mineralogist is certainly mistaken, when he 
asserts that siliceous stones undergo no 
change in the heat of volcanoes ; for the 
white or gtey lavas, with a base of felspar, 
are among the most common, and are some- 
times interspersed with mica, so as to show 
that the parent rock was a felspar mixed 
with that substance ; while die mottled or 

u 2 



29^ DOMAIN XII. VOLCANIC. 

« 

dotted appearance of the lava is such as 
never occurs in any natural rock. The 
quantity of potash recently discovered in 
felspar, sufficiently accounts for its fusibi- 
lity. Nor, so far as the perusal of most 
works on the subject can conduct to an 
opinion, is the power of volcanic heat to 
be computed from a few examples ; while 
it is sometimes, on the contrary, demon*- 
strable to be very intense* 

• 

comractiava It is truly singular that, in the sitate of a 
science so much advanced since the time 
of Dolomieu, specimens of compact lava 
do not abound in every cabinet ; and that 
the subject has not been completely inves- 
tigated; but attention has been diverted 
to crystallography, which may be called 
the entomology of the science, while the 
grandest objects of nature are neglected. 
Dolomieu positively allows that what he 
calls the basaltic columns, chiefly observa- 
ble on the eastem side of Etna, are com- 
posed of a lava, " of which the most com* 
pact morsels are not exempt from some 
little round pores, easily discoverable with 



nOMAIN XII. TOLCAHIC. ^93 

a leDS*/' In this they differ from basaltin, 
one of the most compact substances in na- 
ture; though Werner himself marks its con- 
texture as cellular, or vesicular. Even in 
the purest substances, as glass, the marks 
of fusion by heat remain in little globular 
cavities. But that the question has not 
been examined with due care and sagacity, 
^ill appear from another observation. 
The beautiful forms of basaltic columns Ba»itic ov 

lamns com- 

have, on a first review, been compared '^^^^ 
with the fissures arising from the desicca- 
tion of starch, and some argillaceous sub-* 
stances. But the comparison is in fact of 
the most careless kind, and arises from a 
distant resemblance, as if a trunk of a tree 
were compared with a Corinthian column. 
The accurate eye of Pictet has observed, 
and he has engraved a most distinctive 
characteristic of the columns of the Giants 
causey, unobserved by all writers on the 
subject; which is, that the joints of the 
columns are not only inserted in each other 

r 

* Etna, p. 19^. 



•OHAUI Xir. VOLCAKIC. 



by hemispherical protuberances and con- 
cefvities, but that the corners of one j<Hot 
rise into what may be called triangular 
mortices, nicely adapted to receive the 
next joint, which appears as if cut for that 
purpose*. Patrin showed me, at Paris, 
and has engraved in his mineralogy, spect- 
mens of Siberian emerald, with similar pro- 
tuberances Mid concavities ; the form« 
sometimes admitting of being detached 
when it assumes the form <^ an in-egular 
oval. But no one has doubted that these 
emeralds are crystallised by water; and 
Patrin makes the curious observation, that 
when they are broken in the mine, they 
are soft as an apple, " and the two frao> 
tures are covered with a fluid of an unctu* 
ous appearance, and penetrating smdl, 
which evaporated quitter than a drop <^ 
ether :"-f but exposure to tiie air for a few 

* Da CoBta, howerer, had obMrr«d and engravtd the •ame ap- 
fmrancet, in 17S7. See hj« Fonilt, p. 856, and the plate. 

Min. ii. 33. From ttw aod other t^icumtiaiiccs, detailed ia 
tu parts of hU Hork, Patria argiies Tor a kind of mineral life, 
night have rather said that God fills all space. 

Mens agitat molem, et laagao te corpnre miscct.- 



hours, rendered them quite bard. It might 
hence appear, that to carry the cbemical 
anisdysis of mineral substances to the greatp 
est perfection, means should be oontriyed 
to preserve their natural softness while in 
the bowels of the earth, either by instant 
immersion in naptha, or by other means of 
excluding the air. Tim simple attention 
might perhaps lead to very curious and 
iiliportant discoveries; which might grur 
dually conduct us to rival nature herself in 
the combination of the most piecioufl mit 
nerals. 

To return, as the crystallisation of eroe» 
raids has never been denied, so it would 
appear that the yet more curioufi and re-> 
fined articulations of basaltin cannot be 
ascribed to any other cause. The columns 
of sandstone, and other substances, and it 
is suspected even the columnar lava of 
Etna and other volcanoes, cannot be cpm^ 
pared with this consummaite, and, so to 
speak, artificial architectttre ; for nature is 
the art of God. A prejudiced eye wodd 
find identity; but if no such fomis be 



995 OOMAfN XII. VOLCANIC. 

observable in the columnar lavas, a rational 
argument would arise that the basaltic co- 
lumns have a different origin. Such is the 
nature of lithology, that a very minute diiP- 
ference sometimes constitutes a wide dis- 
tinction ; and Werner's system of external 
characters rests on little tints and shades, 
for which hijs sagacity found expressions; 
while many of them have been known be* 
fore by experienced miners, who felt and 
knew what they could not express ; as a 
shepherd cannot impart the knowledge by 
which he can discern any one sheep among 
a thousand, a trivial circumstance in pas-r 
tural countries. 
Oiwi«of ' The final opinion of Dolomieu, in which 
he is joined by Spallanzani, who visited the 
volcanic regions of Italy with great care, 
though not perhaps with a sufficient expe^ 
rience in lithology, was that basaltin may 
be produced either in the humid way, or 
by volcanic fire. In submarine volcanoes, 
if we listen to the French mineralogists, it 
might be ejected by heat, and crystallised 
in a more compact and beautiful form 



DOMAIN XII. TOLOANIO. Q^^ 

than it assumes when it only enters the 
confines of the sea. It always seems to 
have another singularity, which must not 
be forgotten, namely, an arid and dead 
appearance, ranking it with the stones 
called by the Italians pietri morti; while 
other substances indescribably belong to 
what is called the living rock. 

In the opinion, therefore, of the greatest 
mineralogists, we are only authorised to 
consider as compact lavas those which 
have very small pores; for volcanic ba- 
saltin, though admitted by Dolomieu and 
Spallanzani, is exposed to all the tempests 
of Neptune and his followers. Masses and 
columns of basaltin, brought from well 
known lavas of whatever antiquity, would 
alone form a barriersagainst their attacks. 
A strict examination of the supposed ba« 
saltic columns of Etna, where its vast lavas 
enter the sea, might also lead to some con- 
clusions, whether the opinion of those phi- 
losophers be just, who argue that basaltin 
is always a volcanic product, its compact- 
ness arising from its formartion under the pri- 



f29S OQMAIW XII. YOLeAWlC. 

meval waters, like most other rocks, at a 
period when the power of crystallisation 
was more vigorous, as appears from all the 
other primitive substances; and nothing 
can be more rational than to infer that voU 
canoes not only existed in that state of the 
globe, as they are now known to exist in 
the vast depths of the ocean ; but that they 
must have been far more numerous, and 
of greater power, than in the subsequent 
tranquil state of the elements*. 
Fcrram'B Fcrram, the intelligent professor of na» 

•ystem. or 

tural philosophy in the university of Ca. 
tania, has just published a learned work on 
the volcanoes of Sicily, and the adjacent 
isl^f • This treatise is certainly important 

* In his graod and surprising course of lectures, 18 U, Dr. Davy 
u said to have produced an artificial volcano, being a hillock of clay 
eoclosiogamiztDieofpoiBisiaqi^icoiiiaadliaie: onpovriogwattr, 
> smoke, flame, and lanra, issued from the orater. The earths, he con- 
ceives, may exist in a metallic state in the centre of the globe, and, 
combined iritb wster» may became eartki, and npply nor flOBr 
tinents. 

t I Campi Flegrei della SiciUa, e delle isole eke le sono intomo ; 
• Discntiane Pidca e MUntralogua di fU0U$ Jmde. DelT mbaU 
Francetco Fcrrorat Pr^ess^e primario di Fiska nella Re^ Um^ 
vtrsiia di Caiania^ Doitore di Filosqfia e Medicina, e Socio di varie 
Academie. Mettina, daUa Stamperia ddf Armaia Britanttica. 



BOMAIN XXI. VOlCAmC. jj|^ 

in the history of mineralogy^ as it seems to 
decide some points which were before 
doubtful, and throws fresh light on many of 
the most interesting topics of the science^ 
After a long and patient investigation of 
all ihe lavas in Sicily, and the neighbour* 
ing isles, he has opposed the opinions of 
Dolomieu; whom he justly regards as a 
cursory visitor, who would have retracted 
many of his remarks, if he had simply 
twice visited the same objects, the first 
ideas being often conected by the second. 
After a sedulous attention of many years, 
Ferrara denies that there are any prisms 
whatever, in any lava which has erupted 
since Sicily emerged from the primeval 
ocean. But he is at the same time as de* 
cided in his opinion, that all basaltic co* 
lumns are the product of primeval sub- sotavine 
marine volcanoes. This position he does 

1810, 4to. ''The Burning Fields of Sicily and the minxrandiog 
isles, or a Physical and Mineralpgical Description of these Islands, 
hy iy>b^ F. Fenara, princtpal Piofessor of Nadunl Fhiknophy ia 
the Royal University of Catania, Doctor of Philosophy and M«di» 
cine, and Member of several literaiy Societies. Messina, .from the 
Pmbs «f Che British Army, 1810/* pp. 4U. 



300 DOMAIN XII. VOLCANIC. 

not seem to have borrowed from the French 
mineralogists, but to have adopted from 
his own observation. For this inference, 
which to some may seem arbitrary, and 
even visionary, is founded on an indubita^ 
ble fact that currents of lava, perfectly 
identic with that of the historical and later 
ages, are found covered, and often even 
alternating, with products universally al- 
lowed to have been deposited by the pri- 
meval waters, such as thick beds of chalk 
and limestone, sometimes compact, some-* 
times conchitic. 
c^^tion By his account, and the mineralogical 
map which accompanies his work, the 
whole of Sicily appears to be calcareous^ 
except the mountains of Peloro, in the 
north-east comer, which consist of grey 
. granite, often covered with a bed of lime- 
stone. In that quarter, near a hundred 
mines were formerly wrought, producing 
abundance of silver, copper, and lead* 
The limestone of Sicily is often in the form 
• of what he calls creta^ by which he does 
not seem precisely to understand chalk; 



j>6main XII. voLCAirio. 301. 

but perhaps that kind of earthy limestonef 
which appears under the Giant's causey 
in Ireland, and which has also been 
called chalk. In other parts there are ex- 
tensive layers of keralite, which occasion- 
ally, by his account, passes into the beau-& 
tiful agates and jaspers, for which Sicily is 
famous ; as it is for its singular marbles, 
seemingly affected by the volcanic vapours* 
The chalk he regards as the base of Etna 
itself, which he considers as being entirely 
a volcanic mass of a hundred miles in cir- 
cuit, ejected by the prodigious exteht of 
internal fermentation, which since the cre- 
ation has agitated Sicily and the adjacent 
isles and coast of Italy ; and which must 
exist, as he infers, at a depth almost in-* 
conceivable*. The question of the inten* 
sity of volcanic heat, he regards as merely 
depending on circumstances, being some- 
times great, sometimes moderate ; and the 
quantity of liquid lava may be esteemed a 
standard of the activity of the fire. His 
estimate of volcanic products is the reverse 

• p. 141, 409. 



503 DOMAIW Jai. ¥OLCA«ie* 

of that of Faujas, being extremely simple 
and confined; and he confirms the idea 
which I have long since advanced, that all 
lavas consist of sideiite and felsite. The 
fonner, with Sanssure and other writerB, he 
calls pietre comee^ being a cameus of Wal* 
lerius*. 

The study of extinct volcanoes he con^ 
sideis as, perhaps, more interesting to the 
naturalist, than that of the activef. Not 
only has Vesuvius been repeatedly quite 
extinct for centuries; but even the tre« 
mendous and eternal Etna was quiescent 
from 1447 till 1537- The basaltic prisms, 
as already mentioned, he regards as the 
undoubted pnxlucts of submarine volca* 
noes ; and his account of their origin may 
more accurately be expressed in his own 
words« 
on^of ^^ As a perfect dissolution b necessary in 
Older to form perfect crystals, so a perfect 

• p. 291, 343, 173. 

t '* Lo stadio dei volcani aidenti non essere il solo che possa per- 
§nkmut la Kteaza; che qndlo dq^i eitiiiti h, » oeiti r^guardi, pm 
fecondo dt lumi, e non meno del prime di^gno dell* attenzione, e 
della premura del Nataialiila." Dist> Prel p. tv. 



DOMAIN XII. ▼OLCAKIC. ^0S 

fluidity is required iu stony substances, 
liiat in their consolidation, after their dis* 
solution by fire, they may assume the forms 
to which they have a natural tendency. 
It cannot be denied that many tnodern 
lavas have all the fluidity of which they are 
capable : what circumstance then has per* 
nutted the ancient* lavas sometimes to as* 
sume the form of prisms, which is entirely 
denied to the modern ? 

" A lava which rises from the bottom of 
the sea, must be consolidated in a shorter 
or longer time by the cold contact of the 
water. The lava being thus amassed 
around the orifice^ while the subterranean 
ferment continues, or is even augmented, 
the elastic vapours, acting from beneath, 
must break the upper surface, and occa^ 
sion the lava to accmnulate on itself. The 
sides, however, lemaining always consoli- 

* By thk word he always undentaods, as he ei^Jaina hinudf, 
ihe priHieval sabmarine volcanoes. 

He supposes, p. 989, that the locks are rendered fluid by elastic 
vapours, vapori eUuiici; and, ^tom ihek resemblance to rivers, are, 
Uke ihem, called latfine or lave. Does he refer t6 the Sicilian 
%lialect ^ In part Itdian, kt»are ii to wash, or water. 



S04 DOMAIN XII. YOLCAMIC. 

dated, at length the mass appears above 
the waters; and the crater which rises 
above the waves, communicating with the 
source of the fire, which cannot be inun- 
dated, may thus continue its explosions. 
In this manner were formed, even in our 
times, many isles in the Grecian archipe^ 
lago ; and in this manner must have been 
formed the Eolian isles, and other volcanic 
rocks around Sicily. Finally, when the ef- 
flagration ceased^ the lava which formed 
the great mass upon the bottom of the sea, 
while it was surrounded on all sides with a 
thick arrect of the same matter (now cold 
and a very bad conductor of the internal 
fire, which ought to assume the tempe- 
rature of the water), now enclosed, both 
beneath and above, with the same lava, re- 
mains in the internal gulf, in the most 
perfect fluidity that it can receive from fire, 
to which it has been so long exposed, and 
in a condition to suffer all the activity of 
the subterranean fumace. It is very pro- 
bable that the lava in this recipient, having 
the necessary time, space, and tranquillity, 



DOMAIN XII. TOLCANXa 

cools slowly, and condenses under the forms 
to which its nature tends*. For what is 
crystallisation but the effect of a similar in- 
clination of the more simple, similar, and 
attenuated particles of matter ? It appears 
to me then that this tendency, being faci- 
litated by the circumstances here indicated, 
explains the formation of prismatic lavas, 
without confounding them with the pro- 
ducts of crystallisation/'-f* 

As au example, he mentions the rock 
of Motta, which with those of the Cyclops 
he has also. engraved, in thjs rude manner 
now practised in Sicily! -He observes that, 

* ''A similar combinatMifiipon a vetysnull scale, may have pio- 
duced the few prisms which are found in tlie upper parts of Etna, 
and likewise in the Eolian Isles, not to mention Vesuvius." 

Our author has shown that schistose substances, when melted by 
the volcanic heat, will reassume the same form. But what does he 
conceive to be the natural tendency of basaltin } The forms he de* 
scribes, are not only the prismatic with articulations, but that of 
balls with concentric layers ; and others, in which the prisms con- 
tract and meet in the centre, like the balk of pyrites found in chalk. 
But as iron often assumes the prismatic and gfobular forms, and 
even the radiated and concentric, he ought to have referred the 
whole to that metal, so predominant in siderite, which forms the * 
base of these lavas. 

VOL. II. X 



^ 



4 » 



906 JDOWiltf «II. JOi^A^^O* 

in this and other instances, the centre alone 
is in the prismatic forms, which are some*- 
times found enclosed in amorphous lava, 
identically the same with the columns, 
sometimes in tufa, and somciimes even in 
volcanic glass* But he seems never to 
have seen or observed the remarkable arti*- 
culations, not only convex; and concave, 
hut strengthened by projecting angles and 
recipients, which were first noticed and 
engraved by Da Godj., and afterwards by 
Fictet, in their representations of the g^ts^ 
causey. This striking characteriatic, whidli 
seems unaccountably to have escaped moat 
writers, can scarcely be ascribed to mere 
desiccation ; but seems mther to rival the 
process by which pature produces regular 
lock crystals, in the vast cavema of the 
Alps, of enormoug size, and weighiijg many 
tons. 
coinmns of Other basaltic columns occur in Sicily 
at Vijj^ini, where the coluraus are articur 
lated and a foot in diameter, but only a 
few feet high, curiously arranged PR a 
curved basis ; and they gradually bfscome 



Sicily. 



V 

r 



iMMiiiiii xn. jfiphtAWOm 307 

irregakr, and pass into the amorphous 
lava. At the Motta, already mentioned, 
they are about tvm jfeet in diameter, partly 
vertical partly inclined. At the bottom of 
the colonade the peasants made an ^er« 
ture, where, on introducing the hand, heat ' 
was perceived, and the hand smelled of su)* 
phur. Above are great masses of sand, 
red drosses, and puazolana ; and he infers 
ttiat the prisms are in the centre of the 
Tolcamc mass. It may be said indeed, 
that heat thus enclosed becx^mes inexthoh , 

guishable; and he mentions that, two years 
a^^ the lava of 1669 being perforated at 
Gatania» flames issued; and within these 
ei^ yeajrs it yielded, after ram, smoke 
and great heat This lava is about two 
huhdiied faet in depth, and two miles in 
breadth, and had run about fifteen miles/ 
Other basaltic columns appear near Bronte, 
on the west of Etna, which gave a title to 
the glocious Nekon. They are in beau* 
tiful hexagonal groups, winch disappear in 
the incumbent chalk or earthy hmestone. 

Some not only project from one centre, 

X 2 



508 DOlUm 1^. VOLCAKIC. 

but are bent as if to cover a convex sur- 
face. On the east of Etna, the rock of 
the Cyclops, here also engraved, presents 
on its east side beai^tiful columns of prime- 

«val iftva, disposed in the form of an organ, 
liKe the Organ Rock near the giants' causey. 
Near the castle of Aci, the ancient Acis, 
are found masses of lava in balls, with con- 
centric layers, eight or ten inches in dia- 
meter, involved in a bed of bluish volcanic 
glass. The superincumbent limestone has 
« ' infiltrated and crystallised in the little ca- 
vities of the glass. A reddish baked clay 
also appears, and little prisms of lava about' 
two inches in length. In the neighbour* 
hood volcanic balls are also found in tufa, 
with fragments of lava, glass, drosses, and 
sand. They are generally about six inches 
in diameter, and often break into regular 
pyramids, which are joined in the centre as 
in balls of pyrites; which, he might have 
added, marks the same influence of iron*. 
iaJi%Tima™e, ^"^ Icamcd author totally denies, even 

• r 

• P. 9?, 1 16, 123, 135, 137. 



I>0MAIN Xir, VOLCANIC. 309 

in opposition to his friend Spallanzani, that 
the modern lavas on the east of Etna as^ 
sume the prismatic form when they reach 
the sea ; and regards this opinion as a mere 
illusion arising from the fissures common in 
amorphous lavas, and which may be equal- 
ly observed inHthose that are inland. " I 
must therefore repeat/' says he, " that the 
prismatic lavas around Etna, do not be- 
long to the modern eruptions of that vol- 
cano, but to the ancient volcanoes under 
the ocean ; and that modern lavas, whether 
on the land or in the sea, and under what- 
ever circumstances, never pass into regular 
forms ; but only appear in shapeless masses, 
or in such accidental shapes as arise from 
their site or refrigeration. Two or three 
-prisms which I have found of modern lava 
near Mount Finocchio, on the upland 
skirts of Etna, and some small ones in the 
clefts beneath, must, from their singularity, 
be ascribed to an accident, which can never 
esta\)lish a general system : and I am of 
opinion that to thej&ame accident may be 
ascribed the two or four prisms, which 




I 
\ '• 



v\ 



310 DOMAIir XII. VOLCAiriC. 

«ome naturalists have found in other tno* 
dern lavas ; and the great difference ought 
to be remembered between these scarce 
trifles, and the vast masses of prisms, groups 
of columns, and fascicular assemblages, of 
which even the fragments tend to regular 
divisions, which constitute their charac- 
teristic quaUty/^* 

Even the amorphous lava of the primes 
val period is very compact, sprinkled with 
filifprm crystals of felspar, and some of 
siderite, with grains of chrysolite. That 
of Cape Passaro takes a beautiful poUsh. 
^ The prismatic lavas are very hard and 
compact, and always of a dull ashy colour, 
or a bluish black ; and I have never ob- 
served any pores in prismatic lava/'-f* 
Among these primeval products is also 
found black or blue obsidian, sometimes 
in fragments, sometimes in tables in the 
slits of the lava, and sometimes concave, 

* p. 144. He had before said, p. lis, *' In generale posso dire 
ehe le iave piismadcke, le lave bMsldboe, i basalti, cbe sono iDtomo 
alia base ddl* Etna apparteogono agli avtichi tolcavi» t ooq 
mai alle eruzione moderiie di qaesto volcano.*' 

t P. 176. . . 







• • / 



m 






• i 



OAKMir XII. ▼O&OAKIO. Zll 

M e&velopmg batlls of lava. I^gmdnts 
are also found partly glass and partly lava> 
the former appearing in delicate reins. 
While the lava is decomposed into black 
ferruginous earth, the obiidian passes into 
a light ashy. sttbstanoe« Tlie bubbles and 
cavities are full of calcareous spar^ while 
others, though rarely, pnesent confused 
CTfBtalfl of white and semitranspatent 
quarts. 

In fine, our laborious and intelligent 
author concludes that ** those Neptunists, 
who deny the volcanic origin of the basaltiG 
columns of Sicily, must never have ob- 
served them, el^ they might have seen 
them surroundedL with amorphous lava of 
the same identic paste, and often continu- 
ous with them ; and must have seen in the 
mass fissures which indicate regular divi* 
sions/'-f- Such is this important work of 
Ferrara, which must be pronounced one of 
the most solid and judicious that has yet 
appeared upon the subject. 

• P. 177, 179* &c. * t P. 316. 






3 IS DOMAIN XII. VOLCANIC. 

If the observations on this cufious 
topic, which has so long occupied scien* 
tific men, should in this and other parts of 
the work sometimes appear contradictory, 
let it be regarded as a proof of the author's 
candour, and not of his inattention to a 
subject far from being ascertained. 

The account of the volcanic substances 
will extend to considerable length, and 
some degree of prolixity may be found in 
the minuteness of the details, which was 
necessary for the sake of accuracy ; espe- 
cially as these substances have been objects 
of repeated disputes and contestations 
among the mineralogista^^nd geologists. 



V 



-< 

\ 

i 



> 



HOMB I. COMFACT LATA. 



NOME I. COMPACT LAVA. 



m 



^ 



The volcanic substances are of such various 
kinds> that their arrangement becomes more 
difficult. By far the most important substance ' 
is the lava, which must be considered chiefly as 
it is compact or porous> the former requiring '<| 

particular attention. In Karsten's catalogue f 

there are only two bits of lava ; and as Buffon 
had prejudices against certain rocks which con- 
tradicted his system, so Werner seems absolutely 
to shut his eyes upon the grandeur and import- 
ance ot volcanic productions. Hence they are 
treated with great neglect, and may be said to 
be excluded from German cabinets; while, to 
the impartial observer, they convey sublime ideas 
of the wonderful power of nature. 

As the opinion that basaltin is at least some- Basaitin. 
times volcanic, appears to gain ground, it must, 
when identified by its geognosy^ be admitted as 
the most compact of all lavas. Like porous 
lava, it very often contains grains, or even no- 
dul^» of olivine, or what has been called chry- 
solite; and zeolite forms likewise a common 
parasitic substance. Neither of these, it would 
appear, is found in siderite, or in the basalt of the 



••• 



t^ 



3 



DOMAI!! Xff. VOLCAmC. 



ancients; who^e most common admixtures are 
^^ f . qulEirtz and felspar, and in some porphyries 
^ chalcedony. This observation, if exact, would 

seem of itself to indicate a different origin ; for 
^ if basaltin were merely the more earthy and 

compact appearance of the siderons substances^ 

hornblende^ and granstein, as asserted by the 

Wernerianfi, it seems difficult to imagine why its 

i^- parasites should thus totally differ. Chrysolite 

or oli?ine also occurs in the tnaiies of native 
iton, and other stottes said to hatTe fallen from 
the atmosphere ; and which are well known to 
appear in the form of fiery meteors, and to beai 
other palpable mwks of fusion by heat*. 
Anangement Id tbis diidsionj the lerms HYPONOMfi and 
MicitOKOSi£> implying greater and smaller sub-^ 
divisions of the Nome» will become still more 
necessary, and more strictly applicable, as^ 
though the subjects resemble each other, they 
are widely different in a geological point of 
view. The want of such denominations has 
obliged the writers on volci^nic products to di<» 
vide them into new and untisual classes^ genera^ 
and species; ilk violation of the odier proviacei 
of mineralogy^ where tbeie terms bear quite a 

* P«vha]» in a heated state the toagnesia may combine with th^ 
siloK, and the potash evaporate ; so that felspar and magnesia may 
become olivine. 



,.^^/ 



I 



NOMB X, COMPACT LATA. SlU 

different interpretation. Hence the genera of 

Dolomieu are, 1 . Compact lava. 2. Porous lava» 

3. Scoriae, &c. &c. ; while the genera of Wer- • 

ner are Flinty Clay, lAme, &c. Here, on the t, 

contrary, basaltin remains a mode among the 

^iderous substances, being only a different com*- 

bination ; while among the volcanic it becomes 

a hyponome, being amidst the accidentia), not 

the elemental^ rocks ; not in a series of similar 

combinations, but in a mere assemblage of sub<» 

stances of quite distinct natures, but all altered 

by fire. 



HYPONOMB I. VOLCANIC BASALTIN. 

Volcanic basaltin from Etna, Vesuvius, the isle 
of Bourbon, &c. 

The same, with olivine, from the isle of Bourbon. 
The same, with zeolite, from Etna. 

Mkronomc 1. The same, with various sub- 
stances involved in the volcanic torrent. 

Micronome 2. The same, with fragments of 
ejected rock. 

Micronome 3. Compact lava, with melted gar- 



«* 



«■ 



-»*•<• 



•f* 



-.>:.•' 



If 



316 OOIIAIH XII. VOLCANIC. 

1 

nets, from Vesuvius. The appearance is rather 
vitreous. 

HVPONOMB II. POROUS BASALTIN. 

The three very compact Iiomogenous lavas of 
Dolomieu are probably original rocks; for he 
speaks of their occurrence in blocks*; and the 
grand error of his volcanic treatises is, that he 
confounds antecedent rocks and ejections with 
lavas. 

The siderous compact lavas are thus described 
by Brochant ; who has, however, in this part of his 
valuable work, followed the arrangement and 
ideas of Dolomieu. 
Broriwit'8 *' These lavas are commonly of a black colour, 
more or less deep, seldom grey or brown : their 
f fracture is imperfectly conchoidal, their contexture 

very compact ; they are harder, but more brittle 
than trap, ratker sonorous, very heavy ; they melt, 
under the blow-pipe, into black scoriae ; they at- 
tract the magnet ; they give, by breathing on them, 
an earthy smell : this lava is one of the most 
common in volcanic regions, above all in the cur- 
rents which have issued from Etna, and which are 
' % almost entirely composed of it. 

* Etna, 1 85. 



f^ '. 



i 



*»«.* 






\ 



KOMB !• COMPACT LATA. 317 



ii 



It is seldom that they are homogenous ; they 
are, on the contrary, almost always interspersed 
•with different minerals; those which have been 
most remarked are felspar, augite, hornblende^ 
garnet, leucite, olivine, and mica,"* 

Recently Breislak, certainly an intelligent writer, 
mentions many kinds of compact lava, without 
any notice concerning their rarity or singularity f* 
Ferber, an unprejudiced judge, likewise gives a Ferbei's idaiii. 
catalogue of compact lavas, amounting to fifteen 
kinds. He especially says that the common black 
lava, which covers Vesuvius on every side, is 
porous on the surface, spongy, and light, and 
therefore employed in vaulted roofs ; but at a , .^^ 
greater depth it is extremely compact, and thenj^'' i(\ 
used in foundations, and in paving the streets!. 
^ ■ .Yet he compares it with slags ; and speaks of itar 
being . tnixed with a reddish iron ochijp, like the 
rocks under the basaltin in the north of Ireland, 
aiid in the Faroe isles. But Ferber possibly 
means only porous lava, which he styles compact, 
in comparison with the common vesicular lava': 
and it is possible that the latter may abound in 
cabinets, because it is easily detached from the 



* Brochant, ii. G126, 

f Voyage dans la Caznpanie, Paris, 1801^ 8to, 

X Letters on Italy^ p. 154. 



"^ 



d. 



SIS OOMAIV Xtt« VOLCAIIIO. 

surface; irhite conndcraUe labour aiid time 
mnnt be employed to arrive at the true compMt 
Java*. 

It must also be remembered that Ferber regards 
basaltin as a volcanic production, in Mrbich be ia 
IbUowed by almort every writer, German or 
French, who baa yiaited volcanic countries. As 
it is Werner's plan never to decide on aubataneea 
or re^nsy which he has not seen with his own 
cyesi it is much to be r^retted that he did not 
visit Vesuvius, if he couM not attam the majestic 
scenes of Etna. 

While the French writers are often so pn^ 

psr w diced in leivour of volcanoes, that with them every 

^%. \4Bimck or vesicular stone ia a lava; and the €rer- 

^ ' mans, on the other hacid, deny even obeidian and 

pumice )to be volcanic ; both sides injuring thdr.^ v 
own cause^bv pushing it to an absurd matas ; it 
may be satis&ctory to know the idea^ of I^erber, 
who is at least regarded as an unprejudiced wrifer. 
Besides the black homogenous lava, above meD* 
tioned, his other compact sorts are black with 
leucites, with felspar, with siderite, with chrysc^ 
Mte, with vesuvian, witii obsidian. He adds four 

* Saussure, i. 128, 4to. has obsenred, that compact lava is very 
rare, and found only in the interior of the current. So al^o Ferrara^ 
, p. 301, '' la parte bassa del torreoti ^ formata di lava {du o meno 

compatta.** 






{ 



kkvb of grey compMt lava» with ajdente, Au^te, 
felspar; and red compact lava idn^leucite and 
felspar. But by bis immediate tran&it|o|i to the 
lapUlty tbe 9wdi and the powders, he would rather 
veen^ by the term compact^ to imply a vague dis- ^ 

foctbu from the loose substanGes» than a strict 
appUfation of the word : and this, among a thoiH ^'^ ' .. 
sand^tances, may show the necessity of austere Jfe 

language, and tiie most precise definitions in mi- ^^ 

oeralogy. 

. Faiyaa used to indicate fir^ differences between . 
tiap and compact lavau 1. Trap is soft, and may 
be seratehed by a knife, which on lava loses edge. 
S. Trap attracts iron, but lava is a magnet. ^' ^ ^ Jkj 
In rieetiikity, lava acts like glass. 4. There is np ' ;> ^ 

olivine i|^Wp> hut it is common in lavdit 5. Trap . m 

in a iurmce becomes a traasparant glass, but lava 
remains opake. Th^e distinctions will not, how- 
ever, be admitted 1^ the Neptunist$« In Broq- ^ 

gioiart's oj^moo, compact la?a alwaya presents a 
gtain somewhat crystallised, in which it differs 
firom trap**. If basaltic columns be found on 
Etna, their or^ may still remain dubious ; for, 
aecordmg to Gioeni, the radical parts of that 
momitaiu are basalt, which is only concealed by 




• i. §51. 



r 
f 



\ 



320 BO&HIN XII. VOtCAHIC. 

the lavas*. But Ferrara seems to have decided 
this inquii7.^^..A* 

Porous basaicin, with olivine, from Etna. 

The same, with leucite, from Vesuvius. 

l*he same, with augite, the pyroxene of Hauy ; 
which contains about 15 of iron, and seems a 
*| ^ mere modification of siderite. 






'«.* 



I 



».'< 



Micronome 1. Grey compact lava. 
: All lavas, as already mentioned, with a few tri- 
fling exceptions of mere curiosity, may be classed 
^^ in two divisions: those with a base of siderite^ 

and those with a base of felsite. The grey iavas 



• P. 52. Chrysolite, or olivine, is commoD in native iron, and 
in lava, ib. SIJ^. Gallitzin (Rec. des Noms, Brunsw. 1801, 4to.) 
mentions an iron ore articulated like basalt, mine ot^f^en prismes 
articuUs, comme le hatalie, Brochant has a red hematite of iron in 
prisms, from the mchteibeig near Bareuth. 

The pretended basaltin of Wales, obitrved by Strange and others^ 
at Cader Idris, is, according to recent aad more accurate observers, 
a coarse granstein or basalton, in rude oblong fragments occasioned 
by fissures.' Appearances more volcanic may be traced in the north 
of Ireland ; where the red earth resembles puzzolana^ the krag of 
Kirwran, found near Belfast, is ytrj porous; and the mullen seems to 
some an ash-grey lava with hornblende. Deluc, Geol. 273, ex- 
presses his belief in the extinct volcanoes of Grermany, and says thai 
sections of lava may be observed turned to a central point, and 
forming circles of hills around an empty space, the focus having 
sunk and disappeared. He calls these volcanic crowns^ and the 
centre is often a lake. 



NOME I. COMPACT LIVA. Sg J 

often belong to the latter division ; but are some- 
times so intermingled with siderite, that they ap- 
pear delicately dotted or punctuated. Vesuvius 
presents lava of this kind, which, in spite of the 
interspersion of mica, receives an admirable 
polish. 

Faujas, in his general classification of volcanic 
products, has denominated this kind Laves feld- 
spathiques s and mentions one which is black, yet 
melts under the blow-pipe into a white amel. 
Some, on the C(»itrary, belong to the white com- 
pact lavas, about to be described*. 

- The grey sorts are, " Felsite lava, of a clear Org^iivisof 
grey, sometimes bluish, sometimes rather greenish, 
or white a little inclined to red, of a fine paste, 
rather disposed in little plates than in grains, with 
mica more or less black, and a multitude of irre- 
gular grains of a felspar, whiter or a little yel- 
lowish, which infringes on the base, and whose 
' parts have a contexture and a direction different 
from that of the base of the lava. 

* In his ideas, trap resembles felsite ; but he forgets that iron, 
always a most predominant and characteristic substance, is wanting 
in felsite. 

His classification of volcanic snbstancSes was first published in the 
Annales du Museum -, and latterly, with great variations, in his 
Geologic, tome ii. The extracts here given are generally from the 
former, which is more ample and instructive, on some topics, than 
hb last revision. 

VOL. II. V 



3£S ^OXAIir XXk rOLCAKIC. 

'^ Felsite lava of a ^y white, fine paste, scaly, 
aad of a shining reflection, and satiny, of an ana« 
logons nature to the preceding in respect to its 
eomposition ; but difiers in aa much as the action 
of vdcanic fire has impressed on the paste a cha^ 
racter of fusion similar to that of pumice, while 
the granular fragments of felspar, whiter and of a 
more diaphaDous nature, whkh are imn^rsed in 

r 

the massive febpar, have more resisted the actkn 
of fire, and rwoain nearly untouched. 

*^ Fdsite lava of a deep IsiteUa eokMir, with 
grains of white diafdnanous &lapar, aad a mimfaor 
of small specks of black mica, which have re- 
maiaed untoiiched m dtt midfit of the eferiated 
base, mther porow, and passed into the state of 
pumice. This felsite lava has relations with Use 
preceding ; but its contexture is more rou^, and 
. its pores closer ; its aspect has an aj^iearanee of 
pitchstone; which obtained it, from DolomieUf 
the name of remmfo^^m hva^ 

^' Grey felsite lava, wilh a miiltitiide of ntaH 
globules more or less round, and inherent in th^ 
base, of a substance analogous to that of felspar, 
of a deeper colour than the paste which contain3 
tfaem^ and in w^di tliey have been pnukively 
ibrmed: their contexture is closer and rather 
vitreous. This lava, which is hard^ and suscep* 
tible of being polished, appears spotted^ and pre* 



WOME I. COMPACT LAVA. 923 

seats very small lineaments of black mica; 
scratches ^ss, and melts mider the blow-pipe 
into a greyish white anieL 

" Felsite lara, grey, and sometimes of a whitish 
^y, anak)go«fi9 to the foregoing, with the differ- 
ence that, in this, the paste, which also encloses 
some lineaments of black mica, is looser and less 
adherent, and that the spherical globules are much 
kurg^, and of a felspar a little vitreous, but very 
compact Th^ caimot be better compared than 
to large peas« Some spedmens are found, where 
the base which contains them being in part de- 
stroyed, the globules have resisted, and offer saliaiit 
proCubarances wUeh have a Mse appearaace of 
orfaicukr crystals. These contain in thek* interior, 
as well as on Idbeir sur&ce, linear portions of fel- 
spar, whiter than the globular paste which contains 
tfaem ; there are also some specks of black mica. 
It is probaUe that these globules may pass into a 
kind of obsidian called lucks saphir^ when a violent 
heat produces vitrification." 

As the base of this lava consists of fe^>ar or 
fislfflte, it is often very compact In desaribing * 
an immense current, which descends from the an- . 
dent crater of Etna towards M ascali, Dolomieu 
says that it lies under vesicular lava, and is of a 
very fine grain, and conchoidal fracture, like petr^- 

Y 2 



a 



24 BOMAIV ZXl. yOLCAKIC. 

silex, that is felsite*. There are some white spot9 
of undissolved felspar, and some specks of siderite, 
which occasionally appear rusty aiid earthy from 
the oxygenation of the iron. He also describes a 
grey homogenous lava, of a very fine grain, with 
very small dots of a clearer colour, which, ex- 
amined with a lens, present a looser texture than 
the other parts, and have often pores in their centre. 
His laves dlicies also belong to this kind, being as 
compact as porcelain, with spangles of black mica, 
while sometimes there are long fibres, as in melted 
glassf. 

Breislak says that the grey lava, which issued 
from Vesuvius in the noted eruption of 1 794, is in 
some parts so compact that the grain resembles 
flint It has a faint interspersion of mica;]:. 

Grey compact lava, with very small pores, 
abounds at Volvic in Auvergne, where it is used in 
building : it chiefly reposes on a fine grained grej 
granite. 

Micronome 2. White compact lava. 

This kind is uncommon, and must arise fi*om 

* Dolomieu Etna, 240. See afterwards Bmslal^'t aceount of the 
eruption of Vesuvius, 1794. 
* t Ponces, 104. 



MOMB I. COlffPACT LAVA. 3£5 



pure melted felsite. Dolomieu specially observes 
that the tint is original, and not derived from sul- 
phurous vapours*. Even earthy lavas and basalt 
may be found of a white colour ; but this always 
arises from the action of vapours. White lava is 
found in the little isle of Ischiaf . 

Micronome 3. Brown compact lava. 
This colour may arise from the iron mingled in . 
red felsite. 



HTPONOMB ni. PORPHTRITfC. LAVA. 



As both the substances most general in lavas', 
namely, siderite and felspar, also constitute ge- 
nuine porphyry, it is naturally to be expected 
that lava should sometimes assume this structure. 
The ingenious observer of Etna gives tlie follow- 
ing account^:. 

" I denominate all those lavas porphyritic, ^ccwS* 
which present crystals of felspar, when those 
crystals are of a different colour from the base 
which contains them, and from spots in it. 

" This species is most common : it in itself con- 
stitutes more than half of the compact lavas of 

• Etna, 161. 

t Ponces, p. 71> md lOp. 

I ]>oloiDieu, 312. 



326 DOMAIN Xll. yOLCAMIC 

Etna ; it may even be said that porphyry is the 
essential base of almost^ all the lavas of that vol-* 
cano ; that it chiefly characterises the productions 
of £tn^ and distinguishes it from other volcanoes^ 
where in general porphyries are more rare; 

" The size, number, and form of the crystals 
of felspar, and the colour of their base, will dis- 
tinguish the varieties of this species ; but I shall 
not consider as varieties, the accidents of the 
fractures, which, according to their direction, of^ 
fer inequalities in the form and size of the felspar, 
especially when the crystals are very much flat- 
tened, and resemble a piece of money. 

" Felspar is not always solitary in these lavas, 
it is often accompanied with black schorl, and 
sometimes chrysolites ; both these substances are' 
equally fpund in some antique porphyries. 

" The base, or ground of all these porphyritic ' 
lavas resembles those simple lavas described in 
the first species : some, however, are more sub- 
ject tb be inflated, and have a more vitreous grain ; 
besides the felspar is never altered in its form, or 
organisation, only sometimes it is a little cracked. 
It is generally observed that the more the lavas 
have undergone a violent action of fire, the whiter 
the felspar has become ; an effect which may be 
produced by exposing green porphyry to the fire, 
or antique serpentine, in which the base becomes 



L 



WOMB I* yCOMPACT LkTX* SS7 

black, while the felspar whitens ; it then acquires * 
the property of strongly acting on the magnet. ' 

'' Most porpbyritic lavas are susceptible of a 
fine polish, which always increases the strength of 
their colour ; they then acquire as much bright- 
ness and beauty as natural porphyries, and may 
be substituted for them ; only porphyries of a pur- 
ple, and green bases, are not found among them^ 
because those two colours become black in a less 
degree of heat than that of volcanoes." 

The most common porphyritic lava of Etna is 
of a greyish blapk with white spots, the base re- 
sembling basalt. But the work of Dolomieu 
having been published before mineralogy had ac- 
quired great precision, it is to be feared that he 
has often confounded the lavas with the original 
tocks. 

In one of his porphyritic lavas he observed 
crystals of specular iron ; and as he also observed 
this metal in the same state in the dross of Monte 
Rosso, he concludes that it is formed by sub- 
limation**. 

m 

• Eiom, 379. 



328 



DOMAIN XII. VOLCANIC. 



Analysii. 



Sommit of 
Etna. 



NOME II. VESICULAR LAVA. 

This is the most general and undoubted pro-: 
duct of volcanic fires. The vesicles are some- 
times of an oblong form, but often spherical, 
especially in those with a base of siderite, which, 
even in vitrification, does not assume the fibrous 
form common to other substances. 

From the lava which contains leucite, Vau- 
quelin derived silex 53, argil 18, lime 2, oxyd o^ 
iron 6, potash about 17* The leucite itself con* 
tained very little iron, but presented the same 
ingredients as the lava, with 20 of potash. 

Vesicular lava is the most common and cha- 
racteristic production of volcanoes, among which 
Etna has been chiefly celebrated for more than 
two thousand years. The torrents of liquid fire,' 
vaguely mentioned through a long series of 
learned and illiterate ages, consisted of inflamed 
vesicular lava. Many were thie attempts to ex- 
plore the source of this phenomenon, the sum- 
mit of a mountain so interesting to curiosity and 
even to science. But the best account is that of 
Spallanzani, at once a natural philosopher and 
a mineralogist, and who has sprinkled his de- 
scription with some learned anecdotes of the his- 



NOME II. VESICULAR LAVA. 32^ 

tory of this celebrated mountain. Its length 
and minuteness will only render it the more ac- 
ceptable to the intelligent reader, especially as 
they may serve to diversify the dry brevity of 
some parts of this domain. It may also be con- 
sidered as a counterpart to the description of 
the summit of Mont Blanc, by Saussure, which 
is given in a former division of this work. 

" Three hours before day I, with my compa- 
nions, lefit the Grotta delle Caprcy which had 
afforded us a welcome asylum ; though ourlbed 
was not of the softest, as it consisted only of a 
few oak leaves scattered over the floor of lava, 
I continued my journey towards the summit of 
Etna ; and the clearness of the sky induced me 
to hope that it would continue the same during 
the approaching day, that I might enjoy the 
extensive and sublime prospect from the top of 
this lofty mountain, which is usually involved in 
clouds. I soon left the middle region and en- 
tered the upper one, which is entirely destitute 
of vegetation, except a few bushes very thinly 
scattered. The light of several torches, which 
were carried before us, enabled me to observe 
the nature of the ground over which we passed, 
and to ascertain, from such experiments as I 
was able to make, that our road lay over lavas 
either perfectly the same with, or analogous to, 



330 OQMLAIV XII. VOLCANIC. 

those ia which the Grdtta detle Capre is hoU 
lowed. 

'< We had arrived at within about four miles 
of the borders of the great crater^ when the 
dawn of day began to disperse the darkness of 
night. Faint gleams of a whitish light were 
succeeded by the ruddy hues of Aurora ; and 
soon after the sun rose above the horizdn/turbid 
at first and dimmed by mists, but his rays insen- 
sibly became more clear and resplendent These 
gradations of the rising day are no where to be 
viewed with such precision and delight as from 
the lofty height we had reached^ which was not 
far from the most elevated point of Etna. Here 
likewise I began to perceive the effects of the 
eruption of Etna, which took place in July 17S7» 
and which has been so accurately described by 
Drosses, the Chevalier Gioeni*. These were visible in a 
coating of black scorias, at first thin, but which 
became gradually thicker as I approached the 
summit of the mountain, till it composed a stra* 
turn of several palms in thickness. Over these 
scoriflo I was obliged to proceed, not without 
considerable difficulty and fatigue, as my leg at 

* " His account of this eruiition was printed at Catania, in 1787* 

There is likewise a French translation at the end of the Catalogue 
Raisonni of M. Dolomieu." An English translation of thb singu- 
lar account is afUrwaxds here given. 



NOMB II. VESICULAR ULVA. 33} 

I 

every step sank deep into it The figure of the^e 
9corie» the siriallest of which are about a line» 
or somewhat less, in diameter, is very irregular. 
£acterDally they have the appearance of scorim 
6f iron ; and when broken, are found full of 
small cavities, which are almost all spherical^ or 
nearly of that figure. They are therefore light ^ 

and friable, two qualities which are almost 
always inseparable from scoriae. This great 
number of cavities is an evident proof of the 
quantity and vigorous action of the elastic fluids, 
which in this eruption, imprisoned in the liquid 
matter within the crater^ dilated it on every side^ 
seeking to extricate themselves ; and forced itt 
in scoriaceous particles, to various heights and 
distances, according to the respective weights of 
those particles. The most attentive eye cannot • 
discover in them the smallest short ; either be- 
cause these stones have been perfectly fused» 
and with the lava passed into homogenous con- 
sistence, or because they never existed in it. 
Some linear felspars are however found, which 
by their splendour, semitransparency, and so* 
lidity, show that they have suffered no injury 
from the fire. When these scorias are pulverized, 
they become extremdy black; but retain the 
drynefss and scabrous contexture which they had 
when entire* They abound in iron> and in con* 



332 DOMAltl XII. VOLCANIC. 

ft 

sequence the dust produced by pulverising them, 
copiously adheres to the point of fhe magnetised 
knife ; and a small piece of these scoriae will 
put the magnetic needle in motion at the dis- 
tance of two lines. 
Balls of lava. *' In the midst of this immense quantity of 
scoriae, I in several places met with some sub- 
stances of a spherical figure, which, like the 
lava, were at first small, but increased in size as 
I approached the summit of the mountain. 
These wejre originally particles pf lava ejected 
from the crater in the eruption before mention- 
ed, which assumed a spherical figure when they 
were congealed by the coldness of the air. On 
examining them, I found them in their qualities 
perfectly to resemble the scoriae, and to possess 
the same magnetism. 
Smoke. '^ Only two miles and a half remained of our 

journey, when the great laboratory of nature, 
enclosed within the abysses of Etna, began its 
astonishing operations. Two white columns of 
smoke arose from its summit : one, which was 
the smallest, towards the north-east side of the 
mountain ; and the other towards the north-west. 
A light -wind blowing from the east, they both 
made a curve towards the west, gradually di- 
lating, until they disappeared in the wide ex* 
panse of air. Several streams of smoke, which 



NOME II. VESICULAR LAtA* 353 

^rose lower down towards the west, followed the 
two columns. These appearances could not but 
tend to inspire me with new ardour to prosecute 
my journey, that I might discover ^d admire 
the secrets of this stupendous volcano. The sun 
likewise shining in all his splendour, seemed to 
promise that thi3 day should crown my wishes. 
But experience taught me that the two miles 
and a half I had ye& to go, presented many more 
obstacles than I could have imagined ; and that 
nothing but the resolution I had formed to com- 
plete my design at every hazard, could have en- 
abled me to surmount them. 

" Having proceeded about a hundred paces lii^aof irer. 
further, I met with a torrent of lava, which I 
was obliged to cross to arrive at the smoking 
summit. My guides informed me that this lava 
had issued from the mountain in October 1787; 
and as the account of the Chevalier Gioeni» 
which I have cited, only mentions the eruption 
of the month of July of the same' year, I shall 
here give a brief description of it, as it does 
not seem hitherto to have been described. 

^' This very recent lava extends three miles in 
length 3 its breadth is various, in some places 
being about a quarter of a mile, in others one-* 
third, and in others still more.' Its height, or 
rather depths is different in different parts 9 the 



334 AOMAIK XII. VOLCAVIC 

greatest being, as far as I was able to obaervey 
about eighteen feet, and the least six. Its 
course is dowD the west side of the moimtain i 
and, like the other laVa which flowed in Jaly 
17875 it issued immediately ftom the great crater 
of Etna. The whole number of the eruptiotts of 
this mountain of which we have anj record^ 
before and after the Christian tira> is tfairty-one ; 
EraptioBflfirom aud ten only» as we are informed by GioenSy in- 
cluding that of which he has gif en an account^ 
haYe issued immediately from the highest crater. 
That which I observed may be the deventhi 
unless it should rather be con»dered as the same 
with that described by the Sicilian natutalist, 
sinice the interval between Auguaft and October 
is a very dbort intermission of rest for a volcano^ 
Tbe cause of the rarity of the eruptions whicb 
issue immediately from the crater^ eosupared 
with those which disgorge from the sides, seema 
^aaiiy to be assigned. The centre of this voU 
cano is probably at a great depths and parhape 
eia a level with tbe sea. It is tberefore mueh 
more easy for the matter liquified by Ae fim, 
p«t in efiervesccDce by the elastic fiuid6» and 
impcUed oo every side fitnn the centre to tike 
ctoeumfereBae, to force its way through one e# 
the aides of th^ mountain where it finds least 
resistance^ and there foms a current; than to be 



NOMB II. TEBICULAK LATA. 335 

I 

thrown up^ notwithstanding the resistance of 
gravity, from the bottom to so gre^t a height as 
the highest crater of Etna. It is evident, there* 
fore, that the effervescence in the eruptions of ^ 

the cftonths of July and October 17875 was ex- 
tremely violent. The torrent of the month of 
October is every where covered with sconce, *\ 

which resemble tiMse ejected in the month of 
July in their bhck colour, but differ from them 
in the great adhesion they havie to the lava, in 
their exterior vitreous appearance^ their greater 
weight, and their hardness, which is so great 
that they give sparks with steel almost as plen- 
tiAiUy as fliat& These difleroaces, howeverj 
are to be attributed only to accidental combina* 
ticms of the same substance ; the constituent 
principles of the scorias of this hrva not being 
different from those of the detached scorise 
mentioned above. Both likewise contain ^e 
same fdspar lamrilaou 

** This ai&w current was however very di&- Difficulties of 
icij^t, 9m even dangereus, in the passi^. In 
some phuoes the scor iss pitgeeted in prominent 
as^es ai^ pointy aad in oiineis mmk in hollows, 
9r steep declivities ; in some, from their fragility 
a&d 8moathness> they reannhbd Am phtes of 
ice^ and ia otheia they presented veitical and 
yharp i^fxuiectioMs. la addition to. these dtffi- 



336 m 2I0M.uk XII. VOLCANIC. 

culties, my guides informed me I should have to 
pass three places where the lava was still red- 
hot, though it was now eleven months since it 
had ceased to flow* These obstacles, however^ 
could not overcome my resolution to surmount 
them, and I then experienced, . as I have fre* 
quently done at other times, how much may be 
effected in difficulties and dangers like these, by 
mere physical courage, by the assistance of 
which we may proceed along the edge of a pre* 
cipice in safety ; while the adventurer who sn& 
fers himself to be surprised by a panic. fear, will 
be induced cowardly to desist from the enter* 
prize he might have completed. In several 
places, it is true, the scorias broke under My 
feet; and in others I slipped, and had nearly 
fallen into cavities from which I should have 
been with difficulty extricated. One of the 
three places pointed out by the ^ides had like- 
wise, from its extreme heat, proved highly dis- 
agreeable ; yet at length I surmounted all these 
obstacles and reached the opposite side,' not 
without making several cursory observations on 
the places whence these heats originated. Two 
large clefts, or apertures, in different places 
appeared in the lava, which there, notwithstand- 
ing the clearness of the day, had an obscure i^- 
ness ; and on applying the end of the staff which 



NOMB If. VESICULAR LATA. 53^ 

1 had used as a support in ^his difficult jouraeyi 
to one of these^ it presently smoked, and imme* 
diately after took fire. It was therefore indubi* 
table that this heap of ejected lava still contained 
.within it the active remains of fire, which were 
more manifest there than in other places, b&* 
cause those matters were there collected in 
greater quantities. 

'^ I had yet to encoiihter other obstacles. I had Cone of Etmb 
to pass that tract which may properly be called 
the cone of Etna, ^nd which, in a right line, is 
about a mile or somewhat more in length. This 
was extremely steep, and not less rugged, from 
tiie accumulated scoriae which had been heaped 
upon it in the last eruption, the pieces of which 
were neither connected together, nor attached 
to the ground ; so that frequently when I stepped 
upon oK^e of them, before I could advance my 
other foot, it gave way, and forcing other pieces 
before it down the steep declivity, carried me 
with it, compelling me to take many steps back« 
wards instead of one forwards. To add to this 
inconvenience, the larger pieces of sconce above 
that on which I had stepped, being deprived of 
the support of those contiguous to them, * came 
rolling down upon me, not without danger of 
violently bruising my feet, or breaking my legs. 
After several ineffectual attempts to proceed^ I 

VOL. II. z 



5$( IWMAXII KII. TOLCAVIC. 

fodtid the only method to ayoid this ittcooTe* 
nience and conttntie tny journey) was to step 
only on tho9e large pieces of scoiise which, on 
account of their weight, remained firm $ but the 
length of the wny was thus more than doubled^ 
by the oircuitoiis windings it was necessary to 
make to find such pieces of sconss as, firom their 
large size, were capable of affDrding a slaU^ 
support* i employed tbrAe hojirs in passing, or 
tatber dmggisf myself^ to tbe top of the aioun«* 
tain, partly from being «ndble to proceed in A 
right line, and partly ftotm the steepness of Iha 
declivity, which obliged me to dimb with my 
hands a»id feet^ sweating aad toeaddess^ ami 
under the necessity of stopping at intervals to 
rest, and necover my strength* How moch did 
I then envy the good fortme of those who had 
visited Etna before tihe irruption of ITS?* wlien» 
as my guides asdored Bie» the j<Mimey was fior 
less dUfficttk and laborieasl 
^ ^ I was not move than a hundted and £ttf 
paces distant from the vertex of tho cone, asid 
alMady beheld <doBe to^me^ in all their majesty^ 
the two oolumrn of smoke. Anxious to reach 
the borders of the vtupendoos gulf, I summoMd 
the litile strength I had remaining to make A 
Inst effort, when an anfereseen obstacle for a 
moment cruelly mtnidod the completion of my 



noun a. VB8ICVL4S lava* 339 

ardent wishes. The volcanic craterty if hich are 
still burning more or Ies8» are usually surrounded 
with hot sulphureous acid steams^ which issue 
from their sides and rise in the air. From these 
the summit of ]&tna is nolt exempt ; but the 
largest of them /rose to the west^ and I was ou 
the sputl^-east side. Here likewise four or five 
streams of smoke arcMie from a part somewhat 
lower^ and through these it was nectary to 
pass j siace on <«e sid« waa a dreadfiil pneoi* 
pio9> md <>9 the other so steep 4 declivity, that 
J aod my cpfio^Mmion, from wectkness aud fatigue, ^ 
were w^le to ascend it; ; and it was with the 
«tmo8t difliculty that our two glides insde their 
way up it) fiotwithstaoding they were so much 
BCfiUtQmed to suc^ laborious ^cpeditiom. We 
^cmtiuued ovr J0W7^y> therefore, throi^h the 
juidst of the vaponin^ ; :btit» i^ough we ran as fast 
^ tke ffowAmf^ ovr stre«iigth wonld permit, the 
Miiiftoreous ateims with wbicb they were loadp 
ed were ^xiLmo^y offensive and pr^udicial to 
^espui^ation, and aliectad m^ m paitioular sf» 
nauch^ th^it fprsame moments I wM deprived of 
MQse ; aud (mod, by experience, how daa^er^ 
laus an wndertaJ^ing it is to viait volcanic regions 
mfi^ed by mch y^^ours. 

^^ l^viiQg jessed this plaoe^ and lecovcmd by enter. 
flfB^cees iny former pri^si^e ofjviU^d, iiilesstiha» 

z8 



340 0OMAIV XIU tOLtiANlC. 

an hour I arrived at the utmost summit of Etna, 
and began to discover the edges of the crater ; 
when our guides^ who had preceded me at some 
distance^ turned back, and hastening towards 
tne, exclaimed^ in a kind of transport, that I 
never could have arrived at a more proper time 
to discover and observe the- internal part of this 
stupendous volcano. The reader will easily 
conceive, without my attempting to describe it, 
how great a pleasure I felt at finding my labours 
and fatigue at length crowned with such com*** 
plete success* This pleasure was exalted to a 
kind of rapture when I had completely reached 
the spot, and perceived that I might without 
danger contemplate this amazing spectacle. I 
sat down near the edge of the crater, and re* 
mained there two hours^ to recover my strength 
after the fatigues I had undergone m my jour« 
ney. I viewed with astonishment the configu- 
ration of the borders, the internal sides, the form 
of its immense cavern, its bottom, an aperture 
which appeared in it, the melted matter which 
boiled within, and the smoke which ascended 
from it. The whole of this stupendous scene 
was distinctly displayed before me ; and I shaH 
now proceed to give some description of it, 
though it will only be possible to present the 
jpeader with a very feeble image, as the sight 



VOM« II. TESICVLAE LAVAi 341 

alone can enable him to form ideas at all ad^ 
quate to objects so grand and astonishing. « 
. *^ The upper edges of the crater, to judge by 
the eye, are about a mile and a half in circuity 
and form an oval, the longest diameter of which 
extends from east to west. As they are in seve- 
ral places broken, and crumbled away in large 
fragments, they appear as it were indented, and 
these indentations are a kind of enormous steps, 
formed of projecting lavas and scoriae. The in** 
ternal sides of the cavern, or crater, are inclined 
in different angles in different places* To the 
west their declivity is slight; they are more 
steep to the north; still more so to the east; 
and to the southrcast, on which side I was, they 
are almost perpendicular. Notwithstanding this 
irregularity, however, they form a kind of fun* 
Del, large at the top and narrow at the bottom^ 
as we usually observe in other craters. The 
sides appear irregularly rugged, and abound 
with concretions of an orange colour, which at 
^rst I took for sulphur, but afterwards found to 
be the muriate of ammoniac, having been able 
to gather some pieces of it from the edges of the 
gulf. The bottom is nearly a horizontal plane, 
about two-thirds of a mile in circumference. It 
appears striped with yellow, probably from the 
above mentioned salt. In this plane, from the 



$43 06MAiir xir. toL6AMne. 

place where I Bloody a circular aperture wag 
visible, apparently about five poles in diatneter^ 
from which iseued the larger column of smoke, 
which I had seen before I arrived at the summit 
of Etna. I shall not mention several streams of 
smoke, which arose like thin clouds from the 
same bottom, and different places in the sides. 
The principal column, which at its origin might 
be about twenty feet in diameter, ascended ra« 
pidly in a perpendicular direction while it was 
within the crater ; but when it had risen above 
the edges, inclined towards the west, from the 
action of a light wind, and, when it had risen 
higher, dilated into an extended but thin vo- 
luqne. This smoke was white, and being im- 
4>elled to the side opposite to that in which I 
was, did not prevent my seeing within the aperw 
ture; in which I can affirm I very distinctly 
perceived a liquid ignited matter, which conti« 
nuaily undulated, boiled, and rose and fell, with- 
out* spreading over the bottom. This certainly 
was the melted lava, which had arisen to that 
aperture from the bottom of the Etnean gulf. 

^' The favourable circumstance of having this 
aperture immediately under my view, induced 
me to throw into it some large stones, by rolling 
them down the steep declivity below me. These 
stones, which were only large pieces of lava that 



VOMt II. YEStGVLAt tATA. 343 

I had detached from the edgas of the crater, 
bounding down the side, in a few moments fell 
on the bottom, and those which entered into tbo 
aperture, and struck the liquid lara, produced a 
sound simiMr to that they would have occasion* 
ed had thfey fallen into a thiek tenaoious paste. 
Every stone I thus threw, struck against and 
loosened others in its passa^, which fell with it, 
and in like manner struck and detached othera 
in their way, whence the sounds produced were 
considerably multiplied. The stones which fell 
on the bottom rebounded, even when they were 
very large, and returned a sound different ham 
that I have before described. The bottom can<- 
not therefore be considered only a thin crust } 
since, were it not thick and solid, it must have 
been broken by stones so heavy falling from so 
great a height. 

^ To satisfy one emotion of curiosity, is fte-» 
quently to excite another. I had at first ap«» 
proached this volcano with a kind of super^itious 
awe. The histories of every age, the relations 
of travellers, the universal voice of Europe, had ^ 
all contributed to inspire those who Aould ad« 
venture to visit it with dread: but bs at this 
time it seemed to have laid aside its terrors^ and 
was in a state of perfect calmness and trahquiU 
lity, I was encouraged to become more familiar^ 



344 Domain xii. yoLOANie. 

and to endeavour to pry into more of its secrets* 
I have already observed that the side of the 
crater to the west is of a more gentle declivity 
khan the others ; and I thelrefore conceived that 
this might serve me as a ladder to' descend to 
the bottom, where I might have added to the 
observations T had already made, other new 
and important facts. But the persons whom I 
had brought with me as guides, would not con* 
sent that I should expose myself to such danger. 
They could not, however, prevent me from 
* making at my ease the observations I have here 
published, and walking leisurely about the sum<* 
mit of the mountain, notwithstanding the dan* 
gerous consequences with which they threatened 
me : telling me that, should the wind change^ 
the column of smoke must be turned towards 
us» and might deprive us of life by its pestilent* 
tial fumes ; that besides, we were not certain 
that the lava at the bottom, which now appear- 
ed so calm and still,' would long remain in the 
same state ; but that it was possible, from cir* 
« cumstances difficult to foresee, that it might be 
thrown up on a sudden, and punish our impru* 
dent curiosity by burying us beneath the fiery 
ruin ; in support of which suggestion they pro* 
duced several instances of sudden and most uo^ 
expected eruptions. 



X 

• * s 



NOMB n« TCSieVLAR LATA*. 545. 

^* We have seen above that there were two second enter, 
columns of smoke arising from Etna. It is to 
be remarked that, besides that point of Mount 
Etna on which I stood, there is another to the 
north, a quarter of a mile higher, and which 
renders the summit of Etna properly bifurcated. 
Within the first prominence is sunk the crater I 
have described ; and on the side of the other is 
the second, from which ascends a lesser column 
of smoke* Thie second crater is smaller by 
about the one-half than that I have already. de« 
scribed ; and the one is separated from the other 
only by a partition of scoriae and accumulated 
lava, which lies in the direction of from east to 
west. I made my observations on this second 
crater from a small distance ; but it was impossi- 
ble to advance to it, pn account of the numerous 
and thick streams of smoke by which it was 
surrounded. This, however, was no great dis« 
appointment, after having seen and examined 
the principal crater, which is that whence several 
currents, of lava had issued in 1787. I ought 
certainly to consider myself as extremely for* 
tunate, in being able to gratify my curiosity with 
so near and distinct a view of the objects I have 
described ; as the guides assured me that among 
all the times when they had conducted strangers 
to the summit of Etna, this was the only one in 



546 BOMATB Xlt. FOLCANia 

< 

which they had a clear and undiatorbed view of 
the internal parts of that tmmeiise gulf. After 
my return to Catania, the Chevalier Gioeoi like- 
wise declared to me that in his. difi^reot cxcur* 
sions to that mountain he bad never had a good 
fortune similar to mine ; and that a month be<* 
fore my arrival he had made 'a journey to Etna 
with the Chevalier Dangios, furnished with the 
necessary instruments to ascertain accurately 
the height of the mountain; but when they had 
arrived at the foot of the cone, where th^ had 
proposed to begin their operations^ they were 
obliged to return back, from the obstacles they 
met with, which^ to say the truth, are commcmly 
neither few nor small. 

'< Etna rises to a prodigious height above the 
level of the sea, and- its summit is usually co« 
vered with snows and ice, and obscured with 
clouds, except when the latter are low, and 
range along the sides. , The winds likewise fre«» 
quently blow with such violence, that persona 
can scarcely keep their feet, not to mention the 
acute cold which benumbs the limbs. But the 
most formidable impediments to the progress of 
the adventurers who attempt this perilous jour* 
ney , are the streams of sulphureous vapour which 
rise on the sides, and the thick clouds of sul« 
phureou9 smoke which burst forth from the 



MOltS It. IfBSlCiaAll LATA. 54/ 

I 

mouth of the voleano» eren when not in a state 
of agitation. It seems as if nature had placed 
these noxious fumes as a guard to Etna, and 
other fiery mountains, to prevent the approach 
of curiosity, and secure her mysterious and 
wondrous labours from discovery. I should^ 
however, justly incur the reproach of being un* 
grateful, were I not to acknowledge the generous 
partiality she appeared to manifest towards me. 
At the time I made my visit the sky was clear, 
the mountain free from snows, the temperature 
of t^e atmosphere not incommodious, the th»- 
mometer standing at seven degrees above the 
freezing point (48" of Fahrenheit), and the wind 
favouring my design, by driving the smoke of 
the crater from me, which otherwise would 
alone have been sufficient to have frustrated all 
my attempts. The streams of smoke I met with 
In my way were indeed somewhat troublesome, 
but they might have been much more so; 
though, had our guides conducted us by another 
road, as on my return to Catania I found they 
Alight have done, we should have escaped this 
inconvenience. ^ 

^' It here will, not be improper to compare other 
these observations on the crater of Etna with ^^° * 
those of Baron Riedesel, Sir William Hamilton, 
Mr. Brydone, and Count Borch; as such a 



348^ imMAIK XII' VOLCAllie* 

comparison will show the great changes which 
have taken place in this volcano within the 
space of twenty years ; that is, from the time 
BiedeieL when it was visited by Baron Riedesel in 1767» 
to that of my journey in 1788. At the time 
when that traveller made his observations, the 
crater was enlarged towards the east, with aa 
aperture which now no longer exists* He has 
not given the measure of its circuit, nor has he 
mentioned the interior aspect of the crater ; pro* 
bably because he had not seen it, having been^ 
as I Imagine, prevented by the quantity of 
smoke which he teUs us continually ascended 
from it. 

" It is worthy of notice, however, that at that 
time there was not at the bottom of the cjrater 
the hard flat surface I have described ; since the 
stones thrown into it did not retttm. the smallest 
sound. Within the gulf itself was heard a noise 
similar to that of the waves of the sea when agi- 
tated by a tempest, which noise probably pro- 
ceeded from the lava within the bowels of the 
mountain, liquefied and in motion. We may 
hence conceive how easily a volcano may begin 
•to rage on a sudden, though before apparently 
in a state of complete tranquillity; for if we 
suppose a superabundant quantity of elastic 
substances to have been suddenly developed in 



KOHB II. TSBICULAB LAtA. 349 

the liquid lava of Etna, either at the time when 
Baron Riedesel visited the crater, or when I 
observed it in a state of slight commotion within 
the gulf, it must immediately have swelled in 
every part, beating violently against the sides of 
the caverns in which it was imprisoned, thun- 
dered among the deep cavities, and, bursting 
forth through the sides, have poured out a river 
of fire; or should its violence have been there 
Insisted, it would have rushed up within the 
crater, until it overflowed its brink, and deluged 
the sides of the mountain with its torrents. 

^< Sir William Hamilton, on the 26th of Octo- Haniitoo. 
ber, 1769> arrived at the summit of Etna with 
great difficulty, on account of the snows he met 
with in his way, the severity of the atmosphere, 
the sulphureous vapours, and the violence of the 
wind. He was ^unable to view distinctly the 
iower parts of the crater, being prevented by 
the great quantity of smoke which issued from 
it; though when this smoke was sometimes dri- 
ven away by the wind, he could discover that 
the crater was shaped like a funnel, diminishing 
tintil it ended in a point ; and that this funnel 
was incrusted over with sidt and sulphur. The 
t^rater was two miles and a half in circumference. 

** From the time therefore of the journey of 
Baron Riedesel to that of Sir William Hamilton^ 



1 



SSO 9QUMV Xlli rOLCAVIC 

the crater most h«ve undergone great changef 
in its structures since if the stones that were 
tiirowii into it gave no indications to the ear 
tJ)at they struck against any solid body, it i9 
maacfest that there must thea have been aa 
abyss as well as. a funnel^ and as the funad 
tenuiiaated in a poinl^ when it was observed by 
Sir William Hamiltout it is evident that the flat 
bottom I ha^e descnbed, and which was about 
two ikuods <^ a mile in circuit, did not the^ 
ttist. 

<< The internal sides of the cmter^ *$ir WiOiea} 
teUs us» were C0vc9^ with a crust of s«lt and 
aniphnr; bisit he 4aes not specify the na^vre of 
the Sotmeti and thongh the presence of the lat* 
ter is not improbd^ble* be might have been led 
into a mistake by !the yellow colour^ and have 
taken the mnrisie of ammoniac (sal ammoniac) 
iat anlpbur^ as 1 4id befiue I examined it.. Sir 
WiHiam has not told ns that he made any 
faouniaation at aU ; and it is probable (tot M 
Judged only from the appeamm^e it presented !• 
bis eye. 

** He r^sums, lastly, that the CDEater wtui tnw 
amies 4«ida half in dvcmttfemnoe; jm esfAnate 
wbiohmay be made ta agfee mth mine by nsr 
gleotingthe partitiMii winch separates the^^reater 
aiater fimn the less, and fimmdeiingtbem JMidk 



NOXB II. TE8JCQL4a LATA. 351 



N. 



as one. The sum of the two circumferences, 
acoording to the estimate I have given, would 
then gready differ from the meaduire of Sir Wil- 
liam Hamilton^ Nolhiug likewise can be more 
piobahie, than that aoiong the Tarious changes 
that have happened to El;na, this partition, by 
which the great crater is divided into two parts, 
iotas been produced. 

^< Omitting the observatioM of Mr. Brydone, 
that ** the tremendow galf <bf Etna, so cdebrated 
in allages, has been looked upon as llie terror 
both of this and another life; that it inspires 
inch awe and horror, that it is not surprising 
tlMit it has been conaidered as the place of the 
damned;*' aod other similar philosophical re«> 
flectionBwhidt he has employed; andconfintag 
ourselves to what he actually saw on the 29th 
of Afeay, 1770) we learn from him that ^ the 
crater was tiieii a. oiicle <)f about three miles and 
a imU m ciroBniafrence ; that it wcDt ahelying 
down •n each side, and fimned a regular bol* 
low, like amstampUthBatie; and that a grlaat 
aaoiAh opened near the oentie*. 
. «« Ih>m the tioK of the joumey of Sir William 
Haariten tbeMfixe, to «hat of ike visit a£ Btry^ 
done, that is to say, within the short space of a 



S52 OOMAltf XIL YOLCANIC* 

year^ various changes had happened to this vdU 
canoy by the enlargement of its crater^ and a 
spacious aperture formed in its bottom. 
Bmfa. «^ Count Borch appears to have wished to ex- 

ceed the three other travellers in brevity, relar-- 
tive to this subject; since he only tells us that 
he arrived at the mountain on the l6th of De* 
cember, 1776, and that the crater of Etna ia 
formed like a funnel. He adds, however, what 
is worthy of notice, that the summit of Etna is 
bifurcated, as I observed it to be; a circum* 
stance not noticed by others. Sir William Ha^ 
milton even affirming that the smnmit of the 
mountain is Single; whence we may conclude 
that one of these summits has been produced 
since the time of the journey of Brydone, in 
1770. 

<« On comparing the above*cited observations^ 
made within the space of twenty-one years, we 
may perceive how many changes have taken 
place in Etna during thc^t interval; and aa 
within that time the mountain has suffered only 
two violent convulsions, in the eruptions of 17S1 
and 1787) it is evident that even in the state of 
apparent inaction, it btiU internally exerts its 
force. 
D^OnriDe. « To these observations it may likewise not 
be without utility to add those of M« D'Orville. 



MOMK 11^ VB8ICULA1I LATA. S6S 

He ascended Etna in 1727> and remarked 
two craters, one larger than the other. The 
latter he only mentions, but the former he de-* 
scribes at some length* Its circumference was , 
perhaps somewhat more than four miles. From 
it issued clouds of smoke and reddish flames* 
These9 hovlrever, did not prevent his approach- 
ing to the edge of the gulf; though, to prevent 
the danger of falling into it, he and his compa^ 
nions fastened themselves to a rope held by three 
men* On looking into the crater, they were 
unable to discern the bottom, on account of the 
flames and smoke: they only observed that a 
conical hill, formed of lava, rose in the middle of 
the crater, the top of which they estimated to 
be sixty feet below them ; and they were able to 
see perhaps about sixty lower ; where> as they 
conjectured, the circuit of this hill might be 
from six hundred to eight hundred feet*. 

** We have here a remarkable circumstance 
relative to Etna, as it appeared in the time of 
M* D'Orville, and not observed by any one of 
the four travellers above cited, I mean the coni« 
cal hill within the crater. Every observation^ 
therefore, tends to confirm the inconstancy of 
the internal configuration and dimensions of tbi^ 

• Jacobi Philippi jyOrrilk SicuU. 
VOL. II. S A 



854 BOMAUr Z1I« ▼OLCANIC. 

volcano. It is an unextinguished forge, whicfi 
in proportion to the violence of the fire, to 'the 
nature of the fossil tnatter on which it acts, and 
of the dastio fluids which urge and set it in mo* 
tion, produces, destroys, and re^prodnces v^riowt 
forms. The usual and natural figure of the suqh 
mit of a volcanic moonfaiuy is^ that of 4in invert- 
M concave cone within, and one -solid and er^i 
without ; and such a configuration, in countries 
whichare no longer in a state of conflagration^ 
is one of the most certain indications of the en* 
isienoe of an ancient volcano. This 42one, bow^ 
ev^r, is liable to verj great changes ; according 
to the greater or less fury of the volcano, and the 
quantity and quality of the matters ejected. Its 
internal part,' from more than one cause, is ex^ 
posed Xo continual violence and change. Thd 
pcodigious * cavities of the mountain make it 
almost appear suspended in the air. It may 
easily therefore give way^ and fall in; especially 
on the violent impulse of mew matters, which eiv 
deavour to force a. passage through the upper 
part ; in oonsequetice of which the inverted con^ 
may, according to circamstances, present Ih^ 
appearance of an apertnne, ot wbiripool, or il 
gulf. Should the liquid lava pass th^6l^gh the 
aperture, and continue there some time, its 
superficies by the coatapt of the odd air losing 



KOMB II. TBSICULAt LATA. 555 

its heat gradually, would congeal and form a 
drqfit or solid plane ; and should the fluid lava 
beneath, afterwards act forcibly on this crust, it 
might burst it, or make a passage where jt £Dund 
least resistance ; in which case the melted laya 
would odoupy that aperture. Should then the- 
orust, instead of ascending in a single body, be. 
forced up >ih small fragnkents, tibese cooled in the 
air» Would fall down in immense, quantities wi thin 
the crater;, and, from the effect, of the lawfr 
ofgravity^ must accumulate in the figure, of a 
cone. These theoretical conjectures, if, they do 
not perfectly explain, may at least enable us to 
Gonceive the nature.of the causes, .which have 
produced the difierence of appearance observed 
at difierent times in the crater of Etna. 

*' It is much to be regretted that we have no Changes. 
history of Etna ; whi<ih, did we possess it, must 
greatly contribute to ielucidate the theory of 
volcanoes, and the causes of the various changes 
vihicb ha^ taken place at different times, in the 
summit of this mountaan. That such changes 
have happened, is evident from the few but va- 
Iqable notices poncemin^ Etna, which we find 
in ancient authors. Of these I shall briefly state 
two or three, which appear to be of most im- 
portance. 

'* I shall first produce the authority of Strabo, stnt>o,&c. 

S A S 



356 DOMAIH XII. YOLCANrC. 

I 

though he was not himsdf an ocular witness; 
but relied on the information of others, who had 
visited Etna, and from whom he received the 
account, * That the summit was a level plain of 
about twenty stadia in circumference, surround*, 
ed hy a brow or ridge, of the height of a wall ; 
and that in the middle of the plain arose a smoky 
hill, the smoke of which ascended in a direct 
line, to the height of two hundred feet/ If we 
consider this description as accurate, the crater 
of Etna was at that time surrounded by a brow 
or ridge, which I should explain as the sides or 
edges ; and in the lower part, was separated by 
a mount rising in the middle*. The same geo-^ 
grapher relates, that two men having ventured to 
descend upon the plain, were obliged immediate*, 
ly to return, from the violence of the heat. 

<* Solinus tells us that there were two craters 

from which the vapours issuedf- 

Bembo. '* Cardinal Bembo likewise found two craters^ 

on the summit, the one higher than the other, 

and about as far distant as a stone might be 



* *' This obaervation agrees with that of D'Orville^ mentioned* 
ftbov^. I find likewise that similar mounts have sometimes been 
thrown up within the crater of Vesuvius. See De Bottii Isloria di 
varii incendii del Fesuvio" 

t *' In Etnae vertice hiatus duo sunt^ crateres nominati^ per quos! 
eructatus erompit vapor. Cap. xi. 



NOlfl ir* VBStCULAK LAVA* 357 

'thrown from a sling. The extreme violence of 
the wind, and the exhaling fumes, prevented 
him from approaching the upper crater. The 
lower he found to be formed like an immense 
pit, and surrounded with a plain of no great 
extent, which was so hot that he could not bear 
his hand on it. From its mouth, as from a 
•chimney, continually issued a column of smoke» 

'* Of the other crater, which he could not 
observe himself, he received a description, at 
Catania, from a monk, who, he assures us, was 
a man deserving credit, and well acquainted 
^ith such subjects. He informed him that this 
cvBitet was situated on the highest part of the 
summit of Etna ; that it was about three miles 
in circumference; formed like a funnel; and 
that it had in the middle a spacious cavity. He 
asserted that he had made the circuit of it, along 
a kind of narrow ridge ; that from time to time^ 
it threw out stones and burning matters to a 
•considerable height, roaring, and shaking the 
ground; but that in the intervals, when it was 
undisturbed, he had observed it without danger 
4>r difficulty. 

'' In the time of Fazello, however, who visited ¥ua». 
Etna after Cardinal Bembo, there were no longer 
two craters, but only one ; the circumference of 



'35S :i»oMAiv xfi. vaLCAwio. 

Vhich/ as he informs us, was four miies. It hit 
the usual form of the fimnel^ emitted fine arid 
thick smoke ; but at iutervab was calm, and 
night be epproacKed ; at which- times a sabter* 
raneous noise was beard, and a somod like that 
t>f tbe boiling of an inftmense caldron on a vast 
£re. These^ observations were made by him ki 
1541, and 1544 ; in both which years the crat^ 
appears to have .been 3ingl^. 

<< These few citations appear io' me snflSkiietit 
to show what changes < have taken place -iu the 
sammit^ of Etna,, relative to 'the .number, .the 
form, and the size of its ccaters^ accoidingito 
the difEsrent effiects of its conflagrations at di& 
ferent tiikies;. But there is Ukewise another 
ialteratton which should oroi be passed. unnoUced, 
idescribed'by two writers who thems^esolKaettved 
it, Fazello and BoreHi^ I mean the'faUing ia 
^and absorption of the ex^emesimimit of Etna 
within, ite cr^r* The. former ctfr the abo^e 
mentioned aothors relates that ia bis^ ifcime there 
itrose, in the mouth of the craier, a- little hiti 
isolated on every side, which formed the vehez 
of the mountain ; and which, in a terrible ehi^ 
tion, fell into and was buried in the gul^ thus 

• FazdL.Sic c 



NOBIS n. YBStOVLAR &A1fJU , ^^^ 

eolai^hig the crater, and diminishing the fidgfat 
of the mountain. This hill itself had been pro- 
duced by a. former eraption in \iAJi*. ^ - 
' ^* In like manner, Borelli informs us that in 
the conflagration of 1669> the summit of Etna, 
whidh rose like a tower to a great height above 
the part which is level, was swallowed up in the 
deep gulff. 

' ^* I have already said, that when I visited 
Etni^ its summit was divided into two points, or 
little mountains, one of which rose a quarter of 
a mile alrave the other* I should notbe- sur« 
prised' were I to hear that in some new and 
fierce eruption, the highest of these had faUea 
in, and the two craters became one of much 
larger dimensions* We know that the summit 
of Vesv^ius has sometimes iiaUen down in the 
same manner; nor does it appear difficult to 
assign the cause. It seems to admit of no doubt 
that the highest parts of Etna, and other moun^ 
tains which vomit fire from their smnmits, have 
tiieif foundaUcns on the sides of the cwter^ 
which extend to an immense depth. In any 
violent earthquake therefore, or impetuous shock 
ef the lava endeavouring to force a passage, i* 
may easily be imagined that those foundations 

• Ubi sup. Bordli Hist Inc. Sxom, l660, ^\o. 

t Ubi nil). * 



5^' HOHAIir XfT. TOLCAMte* 

ttiiist be torn up and broken away^ and th^ sutii'^ 
mit of the volcano fall and be lost in the gulf. ' > 
<^ These dilapidations have not» bowever> fron^ 
time immemorial, produced any sensible dimi- 
nution of the height of the summit of Etna ; 
since the losses occasioned by some eruptionsr 
are repaired by others which follow. This may 
be inferred from a phenomenon usually insepa-* 
table from the summit of Etna, though, by rare 
accident, not observable, at the time of my jour* 
hey ; I mean the ice and snow with which it.i& 
covered. > Had any considerable decrease of the 
height of the mountain taken place, in conse* 
quence of the summit repeatedly falling in» in 
Ice and snow, former ages, the ice and snow would -not cer* 
tainly, in a climate so mild, have continued ta 
envelop the top of the mountain as they now>do, 
even dtirihg the heats of summer. But this con-^ 
tinual residence of the snow and ice on . Etna 
has been celebrated by all antiquity ;. for near 
observation was not necessary to ascertain this 
phenomenon, since it is distinctly apj^neujt at 
the;distance of a hundred miles. Adscendti ea 
regio (says Fazello, speaking of the upper regioir 
of ^tna) passuum miUiaferexii; qtaeper hyemem 
iota nivibus obsita extremisque frigoribus riget:: 
per astatem quoque nulla sui parte nee canitie nee 
gelu caret: quod equidem admiricftione dignun% 



•econnti. 



v<mn lu TBttevLAB lata* ',SSl 

est; cum vertex incendia prope sempitema jugi 
Jlammarum eructatiane inter nhes ipsas pariatf 
emitriat, ac continuet. * This region extends 
nearly twelve miles; and^ eyen.in summer, is 
almost perpetually covered with snow^ and ex- 
tremely cold ; which is the more wonderful as 
the summit continually produces, nourishes, and 
pours forth flames amid the i6e and snow with 
which it is enveloped/ 

** Solinus and Silius Italicos give the same de- Andeot 
scription. The former says, Mirum est quod in 
ilia ferventis natura pervicacia mixtas ignibus 
(JEtna) nives profert : et licet vastis exundet in^ 
cdhdiis, aprica can\tie perpetuo brumalem detinet 
faciem*. * * Etna, in a wonderful manner, ex* 
hibits snows mixed with fires ; and retains every 
hppearance of the severest winter amid her vast 
conflagrations.' 

'^ Silius Italicus has the following lines : 

' Summo cana jago cohibet (mirabile dictu) 
yiciiiam flammis glaciem, seteraoque rigore 
Aidentes horrent scopuli ^ stat yertice ceki 
Collit hyems, calidaque niyem t^t atra favillaf.' 

' Where burning £tna« toweriog, threats the skies, 
'Mid flames and ice the lofty rocks arise ; 
The fire amid eteroaL winter f^ows. 
And the warm ashes hide the hoary snows/ 

* Cap. xi. t Lib. si?. 



ggjl .'JMUfAIH XII. VOIrCAVie*^ 

AridMCti I have qinited.a poet^ I wili cite ttra 
fitheras Claudiaa .and .Sinilar ; as it it sufficient-. 
1^ evident that poetry here must e^re^a truths 
and not fiction. 

' Sed quamvis nimio ferrens exaberet ssta, 
Scit niyibus servare fidem : pariterque (kvillis 
Dorescit gbeie8» tanti secuia capons, 
Aicano defenta fida, lumoque fiddi 
Lambit oontiguas innozia flamma pruinas*.* 



the fil^ acommilvtts Ibe doofw. 
And frost renudna where buming ashes glow ; 
0*er ice eternal sweep th* inactive flames^ 
And winter^ spite of fire« the region claims.' 

^' Thus the Latin poet ; but the Gre^ has 
given us a picture of Etna much more highly 
coloured^ representing it not only as the eternal 
abode of sno ws» but. as the column of heaven, to 

• • • • ' 

express its astonishing height 

Ni^oso'a^ Airy a ntavsre^ 
Xtovos o^sixs tiii^vaf. 



•' Snowy Etna^ nurse of endless frost. 



The mighty prop of heaven.* 

It is to be remarked that Pindar lived five hun- 
dred years before the Christian »ra. 

* Claud, de Rapt. Pros. 
t Find. Pyth. Od. i. 



<< I HOW retnm from this digression, wUcll, Smoke. 
4facmgh.not indeed very short, appears to me 
perfectly appropriate to the. snbject; and 'pro* 
• ceed to resmne my narrative. I shaU first speak 
briefly of a ph^iomenon relative to the smoke 
which arises from the crater of Etna, and which 
! was . seen differently by Mr. Bvydone, . Count 
Borcfa, and myself Mr. Brydone tells ns that 
*' from many places of the crater issue volumes 
•of sulphureous smoke, winch being much heavier 
than the circumambient air, instead of rising in 
it, as smoke generally does, immediately oo its 
^getting out of the. crater,, rolls down the side of 
die mountElin Kke a torrent, tUl coming to that 
part ^ the atmosphere .of the same speciftb 
gravity with itself, it shoots <^ horizontally, and 
«fbrms:a iMge track in the air, according tathe 
4lioeetioh of the Wind." '• 

.: f^ On die.cobirary, die smoke Hvheh seen by 
Couhtifioteh,. at. the intervals when the air was 
•calm, aitose^ 'perpendtcolarly, to a great height, 
M|d afierwardsfell,. like white fleeces, 4m the top 
,6f the mdimtain. I shall not presume to dqubt 
these two. &cts, though I observed neither of 
-them. The two columns of smoke wbicb I saw, 
thou^ bent*^ somewhat ft-om the perpendiealar 
fay. tlie wmd, ascended' with the wuil . prattipt»- 



tude of. ordinary smoke (a certain proof that it 
was. considerably lighter than the ambient air)» 
-and, ivhen at a certain height, became extremely 
rarefied and dispersed. This difference in the 
appearance of the smoke, as observed by the 
two authors before mentioned and myself, may 
arise not only from the gravity of the air on 
Etna being different at different times, but also 
from the diversity of the smoke, which may be 
sometimes lighter and sometimes heavier than 
the air. that surrounds it ; differing in its nature 
according to the quality of the substances from 
which it is produced. Such a variation in its 
specific gravity, must induce us to conclude 
iliat the bodies which bum within the crater are 
.specifically different. 
Air. '^ The effects of the air at the summit of Etna, 

as experienced by myself and some of the tra- 
Tellers I have before cited, were likewise different. 
Sir William Hamilton tells us, that the thinness 
,of that fluid occasioned a difficulty of respira- 
tion ; and Count Borch appears to have expe- 
rienced a still greater inconvenience of that kind, • 
since he, says, <^ The rarity of the air on this 
mountain is extremely sensible, and almost ren- 
ders that fluid unfit for respiratidn." On the 
•contrary, Baron Riedesel felt no such effect, as 



KOMS IX. VESlCULXn LAVA. 3fi5 

far at least as we can judge from his own words* 
** I did not perceive, as several travellers have 
asserted, that the air here is so thin and rarefied 
as to prevent, or at least greatly incommode^ 
respiration." Mr. Brydone has said nothing on 
the subject, and his silence may induce us to 
conclude that he experienced no difficulty. 

*' I, my servant, and the two guides, suffered. 
HO inconvenience from the air. The exertions) 
we had made, indeed, in climbing up the craggy . 
steep declivities which surround the crater, pro<« 
duced a shortness of breathing ; but when we 
had reached the summit, and recovered from our 
weariness by rest, we felt no kind of inconve- 
nience, either while sitting, or when, incited by 
cariosity, we went round and examined different 
parts of the edges of the crater. The same is 
affirmed by Borelli : ^que bene respiratio in 
cacumine JEtna absolvitur^ ac in locis subjectis 
campestribtLs. — * Respiration is performed with, 
the same ease on the top of Etna, as in the coun- 
try below.* 

*' Several writers have treated of the difficulty 
of respiration experienced by those who travel 
over high mountains, and other inconveniences 
to which they are exposed; but none, in my 
opinion^ more judiciously than M. Saussure, in 



S£SL JDOMAIH XiU VOLCAKIC* ' 

hts feravds among the Alp3« The obgervations h^ 
has made, appear to ine to explain the cause of 
these different accounts, rdative to the ^ect o£ 
the air on the top of Etna, Wh/en the height 
above the l^el of the sea W6^ two ^ thousand 
four hundred and- fifty poles, or nearly such, 
which, he found to be thai of Mont:BIane>every:» 
ihdividttd felt more or less incoovenience from 
die rarefaction of the air» as happened to him-« 
self and nineteen persons who accompaoidd himj 
when. in August 1787 he ascended that momiK. 
tain. • But when the deTation was much less, a& 
for example, nineteen hundred poles, some of 
these persons felt no difficulty, among wfaomr 
was this.naturalist ; though he confesses that be 
b^gan to experience inconyenience as he ascends 
ed higher. We have hot inti^ied any certaiq 
observations relative to the exact height of Etn^ 
as is sufficiently proved by the diffierent estift 
mates given by different naturalists^ SiguoD 
Dangios, ho we Yen, ai^onomer at Maka, in thk 
year 1787i measured the height of this taMiua^ 
taiii by a giaotodtrical method, and the . phUic « 
anxiously expects tile results, which will sat^ 
&etorily solve this iffl|HirtsM^t problem/ In the 
meantime, from cbmpariqgiheineasures hitbertd 
^ignedj the j^eratloa of Eciuitdnrae the leirel 



•f the sea 117 probably somesvhat less ihaa nitae^ 
teen handted poles*. Henoe we uadenitand 
why respiration^ in many persons, is dot income 
moded, while the contrary happens to others, 
according to the different strength and habit of 
body of different indiyidiials; 

.^^ After having, for two hours, indulged my viewfrom 
ey€is .with a i view of the interior of the crater; 
thai . is, in tUe contemidation of a spectacle 
which in its kind, and in the present age, is 
Wfldiont a parallel in the worid ; I turned ihetn 
to iEtiiather scene, which is likewise nneqqaUed 
fM the niattiplicity, the beauty, and the' variety 
6f this objebte it presents. In fact, there is, 
|iiirhaps, no elevated region on. the whole globe 
which offiera, at oiie view^ so ansple an' extent of 
Ka and lahd as the sunamit of EtnaJ Thd first 
of the snblime objects which it presents, is the 
immense mass of its own colossal body. When 
in the. country below it, near Catania, w6 raise 
our eyesi.to this sovereign of the moontfiiins, we 
c^ertainly.sttrvey it with admiration, a0 it rises 
^ majestieally, and lifts its lofty head above the 
dottds ; and with a kind of geometric glance we 
esthnate its height from the base to the summit; 

* The height of Etna is generally estimated at 11^000 feet above 

* 

the sea. Ferrara seems to estimate it at little more than 9000: 
i6lO^#f (p: l4l), Doo he mean: the French /otic /«*?. 



96s. OOMAIW XII. VOLGAKIC. * 

bnt we only see it ia profile. Very different is 
the appearance it presents^ viewed from its 
towering top, when the whole of its enormous 
bulk is subjected to the eye. The first part, and 
the nearest the observer, is the upper region^ 
which, from the quantity of snows and ice be^ 
neath which it is buried during the greater part 
of the year, may be called the frigid zone, but 
which at that time was divested of this covering, 
and only exhibited rough and craggy cliffs, here 
piled on each other, and there separate, and 
rising perpendicularly ; fearful to view, and im^ 
possible to ascend. Towards the middle of this 
zone, an assemblage of fugitive clouds, irradiated 
by the sun, and all in motion, increased the wild 
variety of the scene. Lower down, appeared the 
middle region, which, from the mildness of its 
climate, may merit the name of the temperate 
zone. Its numerous woods, interrupted in vari« 
ous places, seem, like a torn garment, to dis* 
cover the nudity of the mountain. Here arise a 
multitude of other mountains, which in any 
other situation would appear of a gigantic size, 
but are but pigmies compared to Etna* These 
have all originated from fiery eruptions. Lastly^ 
the eye contemplates with admiration the lower 
region, which, from its violent heat^ may clainot 
the appellation of the torrid zone; the mos( 



t±tenme of the three^ adoraed with elegant 
TiUas and 'Castles, rerdant hills, and flowery^ 
fidds, and * tenninated by • the extensive coast j 
where, to the south, stands the beafitiful city of 
Catania, to which the waves of the neighbouring 
sea serve as a mirror. 

. ^^ But not only do we discover, from this 
astonishing elevation, the entire. massy body of 
Mount Etna ; but the whole of the Island of 
Sicily, with all its noble cities, lofty hills, exten- 
sive plains, and meandering rivers. In the in« 
distinct distance we perceive Malta ; but have a ^ 
dear view of the environs of Messina, and the 

» 

greater part of Calabria; while Lipari, the 
filming Vulcano, the^blazing Stromboli, and the 
Other Eolian isles, appear immediately under onr 
feet, and seem as if, on stooping down, we might 
touch them with the finger. 

** Another object, no less superb and majestic^ 

"was tTO' &r-stretching surfaccvof the subjacent 

sea which surrounded me^ and led my eye to an 

imqiense -distance,' till it seemed gradually to 

mingle with the heavens. , 

^* Seated in the midst of this theatre of the 
wonders of nature, L fdt an indescribabl^lea-* 
sure from the multiplicity and beauty of the ob- 
jects I surveyed; and a kind of internal satis- 
faction and exultation of heart. The sun was 

VOL. II. S B ir 



370 voMAur xif. rouoAmHu 

adTancing to the iiieri4utn» iinofaBCured hy llie 
smalleiit cloud, and* Rteatouf'^ fthermometer 
stood in the tenth degree above the freesing 
point. I was ther^Mre in that temperatiire 
which in most friendly to man ^ and the refined 
air I breathed, as if it had been entirely vital^ 
communicated a vigour and agility to my limbs» 
and an activity and life to my ideas, vrhich apK 
peared to be of a celestial nature." 
cafem. The cuTtents of lava sometimes, contain caverns 
of a very considerable extent. . In Iceland th^ 
afford recesses for the flocks of sheep^. Dolo** 
mieu has described a very remarkable one in an 
island near Sicily; and he also found some in 
the proximity of Etna, spmethnes 30 feet in 
height and 80 in breadth, the v^alls and vault 
; being as r^^ular as if they vrere works oi artf. 
They are numerous; and some, as he asserts, 
many leagues in length. His explani^km is, 
that the surface of die lava foraiing a cnist, is 
sometimes arrested by impediments, while the 
under current continues to flow ; so that upon 
its complete elapse, the space remains void* 
Thus bridges, of some miles of breadth or length, 
are fjftind on the Missouri, in North America : 

I t 

« Von Troil Voy. d'ltUinde, Paris, 178]» the best editioA rerised 
by the author, 
t Lipaii.— Etna, sgi. 



WOMB II. VB8ICULAR LATA. 



the floiatiiig trees being stopped by some, otiita* 
cle. Similar caverns in Iceland, especially near 
Hecla^ are described by Von TtcAL 

The vesicttlar la?a, like the compact, may be 
divided into two principal kinds:, those with a 
base of siderite, and those with a^ base of felsite. 

i 

HYFONOBCE I. OF SIPBRITB. 

This is the most common of all the lavas^ . |pd 
covers the sides and skirts of every volcano*. 
Tha colour is black or grey, derived from the 
melted siderite. The vesicles are generally round; 
the larger^ of two or three lines in diameter^ being 
interspersed with many Smaller pores. It is often 
spotted with white spangles of felspar ; aad the 
vesicles sometimes contain crystdb of .the same 
substance, and sometimes of zeolite. Those of 
Vesuvius^ once itself an extinct vcdcano^ and of 
the extinct volcanoes of Italy in a more northern 
direction, often ODntain leucite, a white sfone crys* 
tallised like a garnet. This last may be s^d to 
form the base of some lavtt, comparatively more 
abundant in cabuiets than in naturef • 

Homogenous vesicular lava, from Etnay Vesu^ 

^ Ssnissarey § 178» concludes that his roche de corne fonns the 
base of dl the black lnvas* 

f Dol. Etna, 44 1 , says that pyrites are formed in dttomposed lara^ 
in the humid way, by the union of the iron with the tulpbwr. 

9 b8 



c 



J^ BOMAIM XII. VOLCAHIC. 

viiis, the Isle of Bourbon, the Puy-de-Dome, 

* — 

The same, with spangles of felspar. 

Vesicular lava of a violet colour, from the extinct 
TOlcanoea of Provence: see Saussure, § 1485, 1495. 

The other kinds are sufficiently remarkable te 
form regular subdivisions. 

Micronome 1. With Leucite. 
lava, with unimpaired leucite, from Vesuvius. 
The same, from Albano near Home. 
The same, with decomposed leucite, from the 
same places*. 

Micronome 2. With Zeolite. 

Black vesicular lava, with fibrous zeolite. 

According to Dolomieu, this is sometimes co^ 
lumnar. 

" A pcA*ous black lava, the pores being exactly 
round, and one or two lines in diameter ; distant 
fit>m each other more than six lines, and some- 
times one or two inches ; the interior of the sphe- 
rical cavities being Uue, while they GoiinnR>nly 
contain zeolite and calcareous spar. This lava is 
crystallised in prismatic columns, moro or less 
regular, in the mountains of Trezza.and of the 
castle of Jaci."f Is not this an original rock? 

*" See Volcanic Intrites. 

fEtna^SOS. Jaci b the Aciof Ferran. 



i^ 



MONl in. IKDURATBD MUD. $73l 

• Micranome 3. With OUoine, or Volcanic 
Chrysolite. 

' These lavas are remarkable, as the same sub- 
stance is found in basalt, and in the native iron of 
S]t)eria and South America. 



HYPONOMB II. VESICULAR LAVA WITB A BA8B OF ^ 

FELSITB. 

. In this kind the vesicles are generally elongatedj^ 
and it sometimes passes into a fibrous appearance, 
which, when predominant, is a characteristic of 
pumice. 

Grey or white vesicular lava, from various vol'-* 
canoes. 

Microrume 1. Felsite lava, with crystals of 
(iderite. 



Micronotne 2. The same, with mica. 



• > 



NOMEm. INDURATED MUD. 

• 

The American volcanoes chiefly devolve top* 
jrents of mud^ which seiems to be strongly im* 
pregnated with iron. Torrents of this kindliave 
also been said to occur in the eruptions of Etna, 



▼OlCMMMk 



974 DOMAIV UL TOLCANIC. 

and even of Vesuvius. Yet no writer has men- 
tioned with precision what form this miul as« 
sumes after desiccation. Brocfaant indeed^ who 
has borrowed his arrangement of the volcanic 
rocks from Dolomieu, supposes that they be- 
come volcanic tufo^. But this substance is ge- 
«; nerally understood to be formed of volcanic sand 
and powders^ dross^ pumice, and pulverised 
lava. The grand volcanoes of Cotopacsi, Tun- 
garunga, and Sangay, in South America, eject 
prodigious quantities of mud ; and, what is stilt 
more striking, vast numbers of fish, so as some- 
times to infect the air with putrefaction. These 
fish appear to be littli^ injured, and are the same 
with those found in the rivulets at the bottom of 
the volcanoes, being apimelodes silurm^ from two 
to four inches in length ; but they are very rare 
in the rivulets which they probably remount, in 
order to pass to subterranean lakes, and are 
caught by the natives at the very sources; facts 
which tend to confirm the theory of volcanoes 
above hinted. 

Late writers specisUy mention that the muddy 
eruptions become fertile clay, and are yerj pro- 
ductive ; while tufo can never be regarded as a 

productive soil. If the muddy eruptions be 

* 

^ Thia is the Julian and claBsical ortbogn^y. T%fa |kw \^ 
reserved for depositions merely aqueous. 



mow. 



NOiit III. INDVKATSA MVD. 3?^ 

stfotigly iiBpregtiftted with inm» they mighty on 
Patrin's theory, become basaltin ; or, if mingled 
with fdspar, a clay porphyry. Bnt this curious 
sutject must remain for future investigation^. 

It was sapposed that Etna, during the erup- often melted 
tiob of 1755, had poured out a torrent of mud; 
but Ferrara has shown that it was only snow and 
ice, qielted by the lava ; and he gives a singular 
instance of the lava having attacked a mass of 
ice, which it partially melted» and left only a 
pile in the midst, which stood for some time like 
a superb palace of crystal. Ulloa also mentions 
a torrent of melted snow, which issued from the 
volcano of Cargaraso in South Americaf. The 
water volcano, as it is called, of Guatimala pro- 
bably ejects mud ; and Ferrara regards Maca* 
luba as belonging to that system of volcanio 

* Mr. Jamei^nt (Oeoga^ 3$3» NoteSi) aays the mud of the Ame- 
rican volcunoes b called Koih by the Spaniards, and Muya by the 
Indians. For this, and some other parts of his Note, he has ad- 
duced no anthofhy ; and ihey seem borrowed, as usual, from some 
iiifM9^«rate Gemian writer. He adds, that this mud is of a blackish 
brown colour, earthy, and not very coherent. There are traces of 
glassy felspar ; but none of sulphur or pyrites. Some kinds are used 
as foel, and emit a strong heat, without flame. Klaproth's amdysif^ 
by this aoDOfuil, yiekied chiefly sikx and aigil* with carbenk add^ 
hydrogen gu^ amonia, coal, lime, oxyd'of iron, and natron. I can« 
not find it in Klaproth*s works. 

t Ferrara, 165. Ulloa, i. 867, falsely quoted by Ordinaire at a 
▼olcanoofmud. 






576 • DOMAIN XII* VOLCANIC* 

w 

heat which influences: Sicily and the neighbour-^ 
ing isles*. ♦ 

His account of the remarkable eruption of 
this muddy volcano in 1777 issubjoined^ as pre* 
senting new and singular: circumstances, 
nof ; << Sometimes this phenomenon appears with 
immense force. The inhabitants of the jieigh*^ 
bourhood still remember with terror the erupt^oa 
of 1 7779 one of the most violent yet known. Oa 
the 29th of September were first heard dreadful 
bellowings all around> while the earth shook to 
the distance of some miles ; and from the midst 
of the plsdn, in which was formed a vast ^gul^ 
arose^ to the height of about one hundred feety 
an immense column of mud ; which, at the top» 
and abandoned by the impulsive foroe, assumed 
the form of a large tree. The middle was^form* 
ed of stones of all kinds and sizes, which darted 
violently and vertically within the body of the 
column. This terrible explosion lasted half an 
hour, when, it became quiet i hut, after a few. 
minutes, resumed its force, and with these int«[w 
inittences continued all the day, but the smoke 
lasted all the night. During the time of this 
phenomenon, a pungent odour of sulphurated 
hydrogen gas was felt at a great distance, to the 

♦ P.43. 



NOMB III. IMDUBATSD MVB. d77 

surprise of the inhabitants^ who did not dare to 
approach this spot on account of the horrible 
noises. But many came the following day, and 
found that the new great orifice had ejected 
several streams of liquid chalk (creta)^ which 
had covered witli an ashy crust of many feet all 
the surrounding space, filling the cavities and 
chinks. The hard substances ejected were frag* ^ 
ments of calcareous tufo, of crystallised gyp- 
sum, pebbles of quartz, and iron pyrites, which 
had lost their lustre, and were broken in pieces: 
all these substances form the outward circuit at 
this day. The unpleasant smell of sulphur still 
continued ; and the water, which remained in 
the holes, continued hot for many months; 
while a keen smell of burning issued from the 
numerous orifices around the great gulf, which 
was now completely filled."* 

In all events, as indurated mud forms, after 
lava and tufo, the most abundant ejection of 
volcanoes, it ought to occupy an important sta- 
tion -among their products. It may be divided 
into two Hyponomes: L Entire; 3. Mingled 
with variottiT^sttbstances. 

* Ferr. 45. Tlie name Macaluba is Arabic, signifying the place 
of spilling or €99rtuming. This fdienomenon is mentiooed by 
Solinns ; nay Plato^ in his Phcedo, mcotioos the torrent or spring of 
mud in Sicily. 



578 BOM AIH 3CII. TOIiCANIlC. 



NOME IV. TUFO- 

CompMftioa. This may be regarded as the fiMirth and last 
of the great vdoanic ejections. It is ehiefiy 
composed of volcanic sand and powders^ op 
what are absurdly called ashes^ of pulverised 
lava, dros8» and pumice. When it consists of 
ferruginous clay it is properly called puzzolana ^ 
when of pumice in a recent state, rapitto or 
lapillo. For as earths are no longer distinguish* 
' od from stones, the difference of cohesion not 
altering the nature of the substance, so tufo^ 
may be regarded as of yarioos indurations. 
These remarks, however, naituridly lead to two 
grand divisions ; the hard tufo, which is used 
as stone ^ and the soft, or incoherent tufo, 
which is also called puzzolana, tarras, &c. 
Tofo of Troil has observed, that the greater part of the 
Icelandic mountains consist of tufo ; and Hecla 
often ejects brown and black pumice, with sand 
and powder, of which substances it chiefly con- 
sists, interspersed with fragments of slate, either 
originally red or changed by fire. Perhaps the 

* Italifaii writers always pat ttifb. It miglit be a not unuseiixl 
dbtinction, aa alitady stated, to onafinc H^ to the Mkateoos and 
•ther depositions merely aquatic. 



ir<Hf» IT. YVFO. gj^ 

base of the moiintain may consist of date 5 and 
the red puzzolana of the Italians may be merely 
tbat substance affected by fire. 

It is well known that, during the grand erup- Volcanic 
tions of volcanoes, the sun is often hid, for entire 
days, with thick columns and clouds of com* 
minuted [substances, called ashe^ by modem 
writers ; white the ancients, with their usual die* 
oernment, used the word powder^. On their 
fall, these powders become coherent and itH 
derated, by humidity and the lapse of ages, so 
as often to assume the' consistence of stone. 
These are also among the most dangerous phe- 
nomena; the city Pompeia having been over- 
whelmed with a bail of pumice, while Hercu- 
laneum was buried under a shower of powders ; 
and in the theatre, constructed without a roof as 
usual among the ancients, a piece wjus found 
impressed with the breasts of a woman, who had 
perished; a circumstance which evinces the 
tenuity of the substance. The hills of the isle 
^f PouEa often present a white argillaceous tufo, 
extremely soft, being chiefly composed of com-" 
minuted pumicef. Breislak observed in Ischif^ . 
Mils of a fine white tufo, sometimes stratified ^ 

* Involutu9 ett (fief pufoere^ papuhtfue sMia no9 ierruit. 
Seneca Quest, oat. 1. 2. &c. &c. 
t Dolomieo, Ponces, 118. 



380. BOMAIV XII* VQtCAJflC. 

• and it sofaddtimeis assumes the a{>pearance of 
pisolite* 

A duef part of Dolomieu has asserted,' that tufo forms nine 
tenths of Mount Etna, and its filiaEl hills ; but 
Ferrara, a more competent qbserver, ^viil hot 
allow that one-htdf is of this sntetanCe. The 
recent eruptions of this grand and perpetual 
volcano have» however, been chiefly remarkable^ 
for those ejections of drosses, powders, and sand* 
which form tufo, as the reader will observe from 
the . following accounts of Gio^ni and Ferrara* 
yet untranslated ; and who, being skilfql litiine* 
rajiogists, deserve more confidence than common 
travellers and narrators* Some degree of pro* 
lixity is indispensable, as already observed, in 
scientific details; and in the description of 
such grand and wonderful phenomena, minute* 
ness, as ^in historical anecdotes, ^ increases the 
pleasure of the perusal. 

Renarkabie in Giocui's accouut of the cruptiou of Etua, in 
teeruptioM. j^jy jtjrgy^ is introduced by the following re- 
marks of Dolomieu, and letter of the French 
Consul at Messina. . ' > 

Doiomies'i ^* While ou the point of closing the enumera^ 
^ion and description of the productions of Etna» 
this volcano, which, during six years, had re- 
mained inactive and quiet, experienced new con« 
vulsions : they began about the 15th of Ju^e* 



and were the forerannerd of an eraption^ which 
manifested the greatest activity about the middle 
of July : the eruption was remarkable on ac« 
count of the immense quantity of ashes^ sandj 
and light pulverulent scorias^ which i^ued from 
its crater^. They covered the mountain^ were 
expanded over a part of Sicily, and carried even 
as far as M aljta. The Chevalier Dangios coU 
lected, on the terraces of the observatory at that 
place, a pretty large quantity of black sand, in 
small hard grains, which were attracted by the 
a»agnet: the sand wa» mingled with small and 
Bomewbat transparent crystals, of irregular 
figure, which, seen through the microscope, 
appeared to be a porous vitrification -, this sand 
was borne to Malta by a north-west wind, on 
the night between the 18th and 19th of July. 

<< Many currents of lava were emitted by this 
eruption, and consequently all those kinds of 
substances which I have attributed to this crisis. 
I have received different accounts of this event, 
which may be serviceable in developing . the 
theory of subterranean^ fires, and support certain 

* '* These ninnerous products of tcorificatioii announce veiy ^ 

considerable efiervescence, and are constantly attended with a great 
disengagement of elastic if olds. Hence the column of smoke and 
flame roft to an immense height ; and the atmosphere was infected 
with tlwodoui of iiilpbar.'* 



38iil DOMAIN ZIL yO&CAWIC. 



eiNiaTatieiis I bave given in, this catalogne. I 
cannot theref<H'6 teminate t^Hi work mcNre pro- 
perly, in my opinion^ than with an ^raet from 
a letter ef M. UAUeneat, French Consnl at 
Messina, in which some curioij^ details will be 
found ', and a trandati<m» by myself, of the nar^ 
rative of the Chevalier Don Joseph Gioeni^ pidb* 
lished in Italian^ at Catania, in September 1787. 



'^ Ej^tract of the Letter ^ M« L'Alldkenst, 
French Consul at Memna, addressed to 
the Com$nat>ider Dolomm^. 

Letter of the ^^ Precisely six years and two months had 
elapsed since the last external symptom of fer- 
mentation exhibited by £ttia, when, towards the 
close of the month of June, the cloud of smoke 
with which its summit is commonly crowned^, 
was observed to increase in size ; this smoke oc* 
casionally assumed the complexion of fire. 

*• Early in July, an opening was remarked on 
the edge of the crater in the north-west, and 
the fire, as seen from Catania, exactly resem- 
bled the full-moon at its rising above the hori- 
zon : the lava made a slow progress for two 

* He was a Ejug^t-oommander of tli* Older cf Maittl« 



VOIIB IV. TVVO» 3jK3 

^yn ; it occupied a space on the slope of two 
I9^1e3 ; becwie, <m cooling, grey and ahiqing i 
and for a time all ceaaed. 

<^ In the night between the 9th and lOtb, aa 
aurora borealis was distinguished, which waa 
visiible for the space of half an bout*, and waa 
fepeateds it^ was largely spread and cotered the 
whole horizon from Monte Rosso as far as Noto ; , 
it» colour was that of light, but somewhat deeper, 
and its direction being the same a^ that of the 
eruption which it preceded,, many conceived it 
to bjB connected with it, and even foretold that it 
would happen, ^ 

^' In effect, on the 13th, a Uack and thick 
smoke was again seen on the summit, which pro- 
gr^^siyely increased, and fire was shot forth 
more frequently and in greater abundance i but, 
in the m<»*ning of the 16tb, though the glare of 
the sun and the thickness of the smoke prevent* 
ed part of the active fire, which issued from the 
mouth of the volcano, from being seen, the ex-* 
treme heat of the atmosphere^ the n<^ from 
the mountain, and the subterranean ei^ploaiona 
which shook the whole of its base, announced 
the vicdence of the eruption being at its acme ; 
still this was not; the case until the next d^y, 
and at ten at nigl)t it presented a most terrible^ 
but» at ihe same tim^ a mo^t interesting speci 






3g4 1>0MAIK Xlh VOLCANIC. 

tacle : a cotQmn of fire> of astofibhing volmne^ 
was seen to rise from the mouthy the height of 
which was estimated at about five hundred toises^ 
it the same time a strong lateral current of lava 
was discovered running in a south'^west direction^ 
«id which leaving the base of the column, form* 
' ed a right angle witb it, the lines n^ly equai 
in length. 

*^ The column itself presented in the colours 
it displayed the greatest variety : the inflamed 
part, abounding in a prodigious quantity of 
water and sand, was occasionally mingled with 
a chiar* oscuro, which at every instant threaten-* 
ed the flame with extinction, but which ulti- 
* mately tended only to increase its vivaoity (and 
on these occasions was it that the eruption was 
distinctly visible at Messina), and the dark and 
caliginous part above, throughout its whole<ez> 
tent, was illuminated by flashes of fire, elMtrical 
aigrettes, and evulsions'^^of ignited stones ; so that 
what with the explosions of the crater, and the 
incessant subterranean rumbling, a strong simi* 
litude was afforded to the ear of a distant 
tempest. - 

^^This spectacle was presented during two 
successive days; on the 19th, all seemed ap^ 
peased. It is not with Etna as with Vesuvius ; 
for no one presumes^to approach this mountaint 



when in a stftte of fehnetitatioti> and only after 
several days of tranquillity dares even the '. 6b> 
server venture on his researches.- 

^* All that can at present be/ said is, that the 
great current of lava v^hich flowed from one. of 
the sides of the crater, ran) the. space of. four 
leagues, alternately threatening the towns, of 
Randazzo and Bronte, especially the latter, which 
the inhabitants were on the point of abandon- 
ing, but we have not heard of its having expe* 
rienced any material damage ; the ignited stones 
wounded two peasants, who were at work at the 
ice-houses, at the distance of two leagues from 
the summit; the rain of sand, which fell in 
abundance on the plain of Mascari, and in the 
territory ofJaciy destroyed almost all the crops. 

" The following are the results of the obser- 
vations of those who, after the termination of 
the las( eruption, visited Etna : 1^. The summit 
of Etna is inaccessible fronnu the /vast quantity of 
lava, and of black and friable pumice (drosses), 
with which it is entirely covered, and. which yet 
retain an intolerable heat; ,S^ The great> crater 
is closed, and another has been formed of equal 
dimensions between that and the. one on the 
western side, closed some years before ; 3^. The 
matter of the eruption is of two kinds <only> 
saline and earthy y 4^. By analysis, the . 

VOL. II. 2 c 



mattor is loMid to eoiMst of aai uimoiiiac, in 
white and jrellowisli erfstali^ wti in « tolerabljr 
pure state; and nanjr compoQiidB of ial aoMM^ 
wac, mingled with Ttrjr ine if<4caiiic sand^ 
which has preveaAed thb salt fiwn astoiaiag ite 
natmal Ibnn and oafeur: the earthy matter is 
componiided5 in rmasaa propMaonB^ of earthy 
alay, iron, and loae." 



rti*«»«Mi 



•• Translation^ hy Dolomieuy of the Narrative 
of the Chevalier Don Jossiph Gioeni, 
member of various Academies, and an In- 
halbitaitt of the first Region of Etna. 

*' loteidnflique ammprarunpit ad ethcfa n«bcin« 
Turbine fnmantem pioeo^ et candente &Till&. 

Vnto. L iiL JEn. 

QuHsni't '^ From the year IWU tfve epodi of the last 

^^^ eraptiaa of Elon^ that monatain oontinned per* 

fectly inadttvei vudy did smoke ascend ftom 

its craiter^ and even daring the earthqodtes 

whic^ destroyed Messina aad |iart of CUabria, 

the vents of dus veieauo seeeMd tobe closed. 

lint ^ About the middle of the last monlh of June 

.ppe«»c«. 1787, 1 inbabitedaoountiy^aseia the middle 

fegion ef the moantain, and dbalF taaacked a 



worn IT. vno^ §^j 

onoke whtefa» iflsuing ffMi tiie crater^ tdU oa 
the oooe^ and corered Hus sammit of Ae rcl^ - 
cano ^ I obsttved occasiooally^ daring the nighty 
that this smoke towards the centre was of die 
colour of fire ; it gradually augmented to* the 
fi4th of June^ when, by riaing in a vertical oo* 
lumn, it foretold a speedy eruption* 

^< Flames were yisible on tihe enuDg of the 
same day, and continued to be so until the night 
ofthe27tb. 

^ On the ^Sth, at eight in the morning, an TUek naoke. 
immeMe coUiom of smoke was seen issuing 
from the crater, of white, black, and red colours* 
which, after aMaioing a considerable elevation, 
was unable to Mstain its weight, and, as if com- 
pressed, assumed the form of a pine ; after this^ 
it sent ibrtb a horizontal line, forming an angle 
cf 60 degrees with the columo in a vertical posi* 
iion, and taking a direction towards the south* 
eaat 

^ This species ^f thick and opake cloud, 
ibrmed by the smoke, after traversing a part of 
Sicily, extended for^ miles out to sea ; it show- 
ered over the whole space it covered a quantity 
*of light scoriss and ashes; while this was pass- OfdraMtsnd 
jng, fresh volumes of thick smoke rose from the 
crater, took at a certain elevation the same di- 
rection along the horizon, and furnished the cloud 

2c S 



^gS DOM AIH XII. VOLeAMIC. 

with the. Voicanicnitttters it incessaatty shoir^ ^ 

ered down. This cloud ck>ntiiiued tbus'SDpphed 

Qiitil the night of the dO(h, when it wholly di8»- 

appeared*. 

' ** In the morning of the 30th, Catania and 

the neighbourhood were covered with a > small 

layer of extremely fine powders. ' 

'^ The flames and smoke continued daring the 
ni§bt ; and the smoke, extending from the sum- 
mit towards the west, indicated the direction (^ 
an eruption of lava ; thle volcano continued in 
this state without any remarkable alteration^ other 
than occasional subterranean shocks. 
. ^' On the 8th of July, at two in the afternooir, 
the smoke increased, rising in mihite ahd opake 

^ globular .clouds^ which rapidly succeeded each 
other ; by these clouds the mountaii^ was covers 
ed, and the atmosphere was loaded with them to 
an immense height; they spread towards the 
west, in the direction of the wind : at the same 

' time a roaring was heard under ground, accom- 
panied by concussions of the earth ; the repeated 
peals of thunder were echoed through the air, 

* ** On visiting the spots covered by this lain of powder^ I re^ 
marked that the smoke had formed a bend towards the south, as^ 
on leaving the crater, it passed over Trifaglieiio and Zqfarana, and 
thence, directing its conne h^ the woods of Jaci^ it leachad the sea 
above Sania Teela.*' 



^. 



KOKE ZV. TUBO. 



389 



Aurora 
boreaJis, 



while the smoke in the west and nortfareiif wA$ 
furrowed' by continual dashes of ligtitabg.:of lightnings. 
various colours; this smoke so much resemdli^ 
a. cloud . laden with hail^ that every body x^on* 
cdved it .to. forebode a violent storiri ; .the cloud 
remained in this st2U;e the space of four hours> 
ivhen.it* was/ utterly dissipated. by the VicJence of 
the. wipd ;. ;the flaaies continued three days and 
nights without intermisBioa. ..; •! 

<vOn the «13tb and ISth^ neither flame nor 
smoke were visible proceeding from the crater; 
and on the. night oi the 18th, .three quarters of 
an hour after nine, a weak aurora borealis was 
distinguished, beginning . to waixlsthb w^sjt^ and 
extending eastward, passing north of Etna; this 
illumination ceased about, ^vea . o'clock, but 
re-appeared^ in the same position as befoi:ei a,t; 
one in the morning : it then.eichibited radii».ap* 
parently diverging from a centre .behind, the 
mountain, and at intervals shone with more^ 
splendour than at others ; it continued thus .visi- 
ble the space of an hour. 
- ^* On the following days the flames increased, 
the subterranean roarings were loud, and the 
concussions. so violent as to iihake the houses^ 
deeming myself therefore no longer safe, so near 
the sumipit, I removed to Catania. 

^< Jn the night of the 17th,. and throughout aoads of nnd. 



Sbockf* 



390 Dtuum XII. VMMAiric. jj^ 

th« XMh, the lulMerfftaean noise was ahiiMt un* 
intennpt^l at five in the ereiiio^^ olooda of 
white smoke^ streaked with Uack^ sprang forth 
in rapid snooeBsiony the one cloud driving for* 
ward the other ; they covered the momxtain and 
spread over Catania^ excluding the light of day 
dnring eight hours ; the clouds showered down» 
almost perpetually^ a rain of vety shining black 
sand ; the atmosphere at first was loaded with 
vapours of a reddish ydlow colour^ which were 
perceptible the space of an hour, and difiiised 
on all sides a smell of sulphur, that jcontinued 
for several hours* 

~ *^ While these vapours infected the atmosphere 
the thermometer of Reaumur rose from 241 to 
98^ (71f to 89^ of Fahrenheit) ; which proves 
that the temperatttre of the air was iiK^reased by 
the heat of the sand. 

^ In the course of the first three houn this 
rain of ashes formed a bed two-thirds of a line in 
thickness i in the five succeeding hours, the 
quantity that fell was the third of a line* 
cj^ikter. ** The crater, at sun*set, presented a wonder- 
ful spectacle, easier for the painter than the 
writer to describe : the flames rose to a height 
greater than ever was known before ; they were 
distinctly seen divided into three large columns, 
which rose either, at once, or at separate inters 



t9h, mA Aot forth «ci abmidwdo of ignited 
iloDes ; part of whiob falling back into the 
crater, iMsied to aogment the violence of the 
floney wbtte the other part rolled to a condder* 
aUe difttaoce down the flanfci of the cone« 

^ The meke,. accumulated at a considerable 
heigbti wae mingled with flames, which oaet a 
light on objects similar to a weak moon^-light i it 
occupkd a great horizontal eacftent, above which 
rose the diree columns of fire. Another column 
of very dense smoke was. noticed, proceeding at 
interrals fkim a ?eat in front of the others $ it 
concealed for some instants the centre of explo^ 
sion, and, extending towards the south, united 
with the other smoke, which, forming an arch 
several miles in length, served as a conductor to 
the electric ires j its eatrem ity was frequently 
furrowed b j lightning. 

^ The height of this cdomn of fire, wbiclK 
continued firom eleven o'clock till midnight, seen 
from Catania, was estimated at half that oi the 
mountain. 

* After the eruption had lasted five hours, 
the mountain was enveloped in the deepest dark* 
ness, except the crater, which still emitted 
flamei to the same height as the day before; 
besides the first, three other currents of lava 
seesMd to be eiected ; one towards the east^ami 



991 



392. DOMABC XII. ' VOLCAJflC. 

two towards the soulh^ waA all .m divergemt radii 
from the crater; but observing them alter waidi 
with a good telescope^ I perceived- that the three 
supposed currents of lava were no odier.thao 
massed' of scorise heaped together during the 
etuplAOA) which continued to bum <m the flianks 
of thc^ cone, and which became extinct at four 
io the morning. 

^^ 'A second eruption seemed to imnounce it- 
lelf on the following day, when, at noon, an 
immense number of whirling clouds of white 
smoke issued from thek^rater, spread themsdves 
fiom east to west, and: by three o*clock attained 
an immense elevation ; it seemed as though they 
would cover the city of Catania; but they 
merely tenninated in flashes of lightning, similar 
to those of die day before^ rather more pale, and 
which issued from the more elevated globes. I 
afterwards understood, that in the second and 
Iftiird region, some aqueous clouds uniting with 
the smoke,' a very violent rain fell mingled with 
volcanic matters, differing in a small degree 
from the first; in the apace of an hourj^ the 
whole was dissipated, and the n^ountiun waa 
clear. 

*^ The ordinary flames continued during -the 
night of the 20th of July ; th^ somewhat in- 
preased at two in the morning, ^mdeven assumed 



MOMB IT.. TinPO* S93 

tlie form of a colamn; ,bat the fermentotioii 
diminishing, they resumed their former appe^« 
ance in abont half an hour's time» and preserved 
the same during two or three days, subsequent 
to which die mountain resumed its pristine tran* 
quiUity. 

*^ It is evidently visible that, on this eruption^ 
the extent of the crater was diminished towards 
the: souths and increased; towards the west 

f f From . the testimony of individuals worthy siie 
of credit, I learn that, on the 18tb of July^ 
blocks of dross, weighiiog ap^und and a haif^ 
ejected from the crater, fell in.tha valley of ^fi^^ 
thaA is to say, five;miles and i^ third. part of a' 
mile from the spot; others likewise were thrown 
to different distaufses, in all directions round 
about the crater, diminishing, in size in propor- 
tion to the distan.ce. 

. '* At La Cava Secca, six miles from the crater,, 
ifome fell the size of a pigeon's-egg ; at twelve 
mjles from it, fragments of dross blended with 
SQind formed a bed more than three inches in 
thickness. Duri,Dg the rain of which I have 
spoken, the whole pf the middle region of Etna 
was enveloped in darkness ; but chiefly in the 
eastern part> where the greatest quantity fell. 

. '^ The inhabitants of Zafarana were unable to 
0e9 ^cb other at the distance of two feet ; and'. 



5^ Mduam xfi. v«eMric. 

wkai the flamei began to i^ipear, they wwe 
Ttlopedi&Tapeunefiiitolenbleheat; diefiiiMU 
gined the moimtain was sinking into the abysa 
fnm which it qf^nemg : part of the inbabitaala 
abandoned the Tilli^ and comtemation waa 
universal i the volcanic matter retained a heaft 
which it comnranicated to the atMioiphere» and 
tiie air was loaded with leddish vapour; the ram 
that fell ruined the vineyards and trees of the 
middle region, the latter in many parts having 
nothing but the trunk left standing. 

** From Brmte we had information that, dih- 
ring the night of the 18th of July, a cnrrent of 
kva ffom the crater surrounded a wood in the 
neighbourhood of the town ; and from its having 
made a progress of several miles in very little 
timci it caused there the greatest alarm. 

*^ Feeling a desire of examining on the spot 
the effects of this eruption, the more extraordi- 
nary from its having proceeded from the summit, 
and not occasioned any opening in the flanks <ii 
the mountain, I repaired in the beginning of 
Bronte. August to Bronte : this town, situated north- 
west of the crater, stands at the distance of six 
miles from it, in a direct line ; within the inter* 
val are several volcanic mountains, and currents 
of lava which have traversed imd laid waste a 
thick wood of fir, whose deep roots were fixed 



in aodcnt Iwa^ decompostd and ooBTertod into 

ewlli*. After {NMsmg thoie arid spots, I aaoead^ 

•d a hill^ from wkksh I dearly distingiiiriied tiro 

W0W corrents €£ kiTS: the first had flowed Con;^^^^ 

w. N. w. of the crater over the flanks of the 

cone, between the two territories of Bronte and 

Ademo ; I was assured that the breadth of this 

stream was a mile, and its length three miles ; it 

was formed on the I6th and 17th of Jnly, and 

on the 18tfa the rate of its progress had so mndi 

diminished that it ceased to advance more than 

a few fathoms. I was nnable to approach it, on 

acCQnnt of the steepness of the rocks by which 

it was surrounded* The second stream, which 

took the direction v. W. by k.> was^ at its is* 

suing from the crater, half a mile in breadth } it 

qiread afterwards so as to become a mile broad, 

and descending rather in an oblique line down 

the npid slope of this part of the cone, divided 

into diflferent currents, which left between them 

* " I wat obliged to travene the camnt of Uft^ medeby tlM 
eraption of 1766, the most leoent of aoy which took this directioii j 
I saw several streams of lava which had crossed others^ and which 
M kft&ed me evident pioofi of the fidlacy of the concluaions of those 
tliho sedt to estimate the period of the formation of the beds of lava 
fiom die diange they have undergone. Some lavas, of earlier date 
than others, still resist the weather, and present a vitreoos and un* 
alierad sar&oe, while the Isras of later date already begin to be 
cofdM wnn v eg e i aiioa. 



31^ DOM AtiT'' XII.. * .VdtCMIIC. 

falribiis eminetKsed -tliey met in tteir coarse^ 
these! streams united' to form but two branches, 
after i having floweddrer a. space t)f four miles in 
d 'Very short period ofitime^.in the night. of 
Ae Ifith* 

i '*. Nearly die whole, sur&ce. of this lava was 
covered with smoke, which issued :ffom crevices 
in the mass, and whic^h increased in (fnantity io: 
proportion to its. proximity to the .crater ; much 
smoke likewise arose from the crater itself. At 
two in the. morning, the thermometer. of Reaur 
mur stood at 19\ (6IS44 of Fahrenheit*). 

: ^' On reaching the ^^tremity of one. of the 
branches of lava recently ejected, I found it still 
continued hot, and the heat was more sensiULe 
as I advanced upon it. The thickness of this 
stream did not exceed sixteen feet. Placing the 
thermometer upon the drosses on the surface, 
the mercury rose to 28 (92^ of Fahrenheit), 
and had the guide allowed, us to advance farther^ 
the heat would have been still greaterf. I 
brought away some of the light drosses and 



. • ** fidbre I reached the lava, I made an experiment with the 
new atmospheiical electrometer of M. de Saussure^ the air, not* 
withstanding I raised my arm with the instrument as hi^ as pos- 
sible, exhibited no indications of electricity." 

t ^' The divergency of the balb of the electrometer^ virith which 
I here made some experiments^ did not exceed the fraction of a line f . 



lieavy lava, of which the whole of this current 
•eetned to be composed. 

'< Learning for certain tbiett there wiE» not oii 
the north of Etna any new current of lavaj I trod 
iiack my steps iowsaAs NicolosL I re-ascendeil 
the mountain on the 11th of Au^ost, and bent 
my way directly towards the crater, 'to examine 
"the changes which' an explosion so violent must 
necessarily have effected : smoke rose from the 
crater in great abundance, and to a consiilerable 
height; but, driven by the wind towards the 
east, it was no prevention to my plan. 

" From the very walls of Nicolosi I. noticed 
that Abe earth was covered with small fragments 
of light dross, which became larger in proper* 
ti'on as I approached the summit; I found th^ 
had covered the whole space denominated the 
plain del Lago^ io-such manner that the former 
soil could no longer be distinguished ; the time 
of my departure on the excursion was. half past 
nine in the morning, and the thirmbmeter stood 
11^ [521 of Fahrenheit). 

«nd it disappeared at three feet distance from the lava. To ascertaia 
correctly whether or not there really was any difference in the state 
of electricity, I several times got upon and descended from the lava, 
and found not the slightest divergency of the halls on removing to a 
distance of forty paces ; the slight electricity in the lava was of a posi- 
tive kind, as I convinced myself by means of a stick of Spanish Wax." 



V9<t 



OOlUm XXI. VfMUIklllC. 



^< Oft irachiog the PbUoMpbei^^ T0iy»r*» mj 
guide measure the heighi id the bed of immm^ 
find fiwiid it thwe fi^s but* at the foot of the 
eone^ two miles dtttantfi-oin the crater in atifhft 
lioep J computed tJie ftraitiim of dfMae» to be 
lurelve feet in thickness. 

*^ I fimod a immber of insulated round bbcfest 
which had heen thwwn oat from liie Toteaoo 
towards the w. n. w»» and in the aame directiiNi 
Another I aaw4| CHnr«t of lava^ stifl inflamed and smok^ 
^^'^'^^ iflg^ which was deseeadiag firom the crater* aad 
at its origin was nbont iMlf n mile sn hreadth ; It 
afterwards swelled to • heeadA of thne «iHes» 
anlesstended two miles jftleogl^; the height^ 
Ihe cwrent, at its sides, was fiiom twelTeio jix«> 
teen feet» but in theoHddle twii^ or ere» fenr 
times 00 much ; thecnnreat ooitf inued to foctawe 
fimh natter ih>m the crater, as wm todicated Hj 
the slow motion of the drosses with which its 
aorfiso^e was cowred* and thOiflflmes which f ror 
ceeded from th%oeeasianall|r doren sui&oey and 
which, notwithstanding the day-light, were visi- 
ble; we at the same time perceived that the 
progress, in a Ibrwaid directioB of the ciurrent, 
was arrested. 
Cone. ^* The portion of the cone we had to pass, in 

• Pkobably built lAn^ the JSofteror Hadriao ewloe idaitcd 



Qidfcr to peach the crater^ benig covered with 
this lava, we were eonseqnentlj obl^ed to ad* 
Tanoe over it, feUoving oar gttide^ who picked 
lus ilep6» choosing thaae dranes to tmd upon 
which were the kast friaUe ; but our labour was 
vain» anoe» on reaching the kiolred4er terin of 
owrjonmey^ so great a qoantitj of smoke istoei 
as entirely to fiU the movth of the crater, aad 
Iprokibit all approach. 

*^ The guide, who had paidavitit to the same 
spot seoM dajrs before, informed me that he paw 
oeired a connderaUe increase in the formeait** 
tkm of the moootain ; and what he stated was 
confirmed by a smoke, which ascended from a 
iMmber«fthediasfli»of JUiwfe AxM», although 
this moaDtain IS at n distance «f three mies fiom 
tiie enter. 

*^ Before I quitted the lava, I placed the ther* 
momeler on a piece of heavy dross, about the 
middle of the onrrent ; the asercury , in two mi* 
nutes, rose to ;22^ (ff^ Fahrenheit*). 



399 



* " The dificnlty of tbe titnatim did not adiiut4if my jDakii^ 
experiments with the electrometer; but on wramining thU inttni- 
menty at the distance of a mile from the crater^ I found the diyer* 
geiicyortlieballt«Lt«idedtothfee4iM»aD4«ftMlimi$ thklthal 
pmc m md lo ba tmwg to a ctowd» -which wm p aii ing pcrpeniJ cu la t^ y 
over my head ; when the foot of the ekctrometer touched the earthy 
the electridty disappeared ; and repeating afterwards the experiment, 
1 Bomid the diverftetiey ind Ml CMceed'Ooe une* 



400 DOMAIN XII. > tOLCANIC. 

' **' Directing nowi my steps toward& that part 
<)f the" cone which fronts the south, I found there 
another small current* which had.iiot^ like the 
restf' |>roceeded froth the crater^ bnt which, on 
the 18th of July, formed an opening fortitself, 
lialf a: mile below the prater; this« eruption had 
Ibrmed a small mountain of aconic/orm, with a 
lateral opening, through which the current flow* 
ed in a breadth of half a mile, and to the length 
of a mile. My guide informed me, that it was 
from' the inferior opening of this small cone that 
the smoke, mixed with sand and light drosses, 
issued, which ocicasionaUy concealed the ; fire 
from the great crateh 

^' This partial eruption was not yisiUe from 
Catania, on account of the interposition of 
Monte RossOf immediately between the summit 
of Etna and that city. 

^^ The appearance of these two small streams 
19 not so horrible as that of Bronte^ on account 
of their being of different colours, produced by 
the iron in the lava; which is deprived of its in^ 
flammable substance by the sulphuric acid,* ren- 
dered more effective by heat. 

'* I examined many insulated pieces, darted 
to the distance of one or two miles, aod remark* 
ed their figure to be a pretty regular oval ; their 
larger diameter was five, and their smaller three 



mouM IT. Tvro* 401 

feet ; I found a similar bloek projected the dis- 
tance of three miles, its diameter one way was 
eigl^t, the other four feet ; its prodigious weight 
had occasioned it to bury itself almost entirely 
in the drosses^ and its surface, alone w^ias visible. 
^' Pieces of such great bulk are not numer<Mus } 
but it is impossible to calculate the immense 
.quantity of light and heavy drosses, which, at 
various elevations, cover the cone itself, and the 
country £3r several miles around; and which, 
during the most violent part of the eruption, fell 
in the form of rain. The streams of solid lava 
•added together would form a solid mass, includ* 
ing interstices between the parted streams, of 
6^218,661^6 cubic feet. 



« PRODUCTION OF THE ERUPTIONS OF THE 

MONTH OF JULF, 1787- 

<< I have minutely examine the productions 
of this eruption, which may be reduced, to the 
following varieties. 

<* No. I. The first rain of volcanic matter, at DnMwt mi, 
.first sight, appeared to consist of a yellowish 
puzzolana, such as is found. near the craters of 
volcanoes, after their .having been long extinct; 
it is composed of pieces from the size of dice 

TOL. II. 8 D 



40t DOHAIII^XII.'. T^iUO^IC. 

4<}wii to that of the Sixkik powdar \ Hild is it 
yorotii laFE, li^t» teader) bod sodieiriiat jo- 
MmUiog an argiUaceous substance^ whieh iB 
artringent to the totigue $ aomia of the graias aife 
hard lava, heavy, ferragaioost aod ia raiiiid 
particles. Naariy half of this fimt voicuiG rain 
eoosifitod of TGiy fine powders; thcse^ Mdi 
tfamugh a mieroBcope, appear to be composed* 
1. of crystals of bbck seborl*^ which paitiaUy 
retain their prismatic shape, and are pattiidly 
leaten bj rait; S. vitreous grains of lioiilar 
acfaorl ; 3. grains of lava which have under|;ooe 
Alteration, and are reddened or wMbBpcd bjr Ta^ 
pour; 4. crjrstab of felspar, detached, and al- 
though somewhat decomposed^ preserying their 
rbomboidal form ; 5. other crystals of felspar 
adhering to lava^ changed and covered with 
fiirina externally, but internally untouched ; 6. 
fragttietits of lava with ^stnall crystals, similar to 
the arsenical ruby; 7. others incrusted with 
flowers of sulphur ; iS. vitrifactions of no regular 
figure, porous Titiiiactions^ and iat species of 
black glass or obsidian, transparent at the edges 
and ef a dark greeti^our. 

^ The maMer here analysed was coftlected on 
the snows of the crater at Trifoglvetto. 

* Schorl w^ tbeii ft Mine lor nderite, or ltoiiiMtdJe.JiA.R, 



K^UE IV. TVFO. 4) W 

" No. II. Heavy drasBes of neariy an oval 
ahzpe, and weighing from six to eight and moe 
pounds; snob were projected the distance of 
four miles from the crater ; superficially tliey are 
vitrified^ their pores are glossy^ and are five or 
six lines in diameter. The centre of these 
drosses has rounded and pretty regular pores; 
it contains crystals of white felspar confiisedly 
dispersed^ and some volcanic chrjrsolites. The 
crystals of felspar preserve their transparency* 
and are merely a little glazed, while the chryso* 
Jites have undergone a species of fusiou, which 
has combitted their grains, and rendered their 
5vrface cowvex. 

*^ These drosses are found round the crater, 
especially from the southern to the eastern side, 
as well as in the yalley of Sue. 

^^ No. III. Light whitilA drosses, similar %o 
the cavernous pumice-stone of Lipari; they have 
the same fibrous texture and prolonged pores ; 
some little light drosses, of a black colour, ad-» 
here to this pumice, whiclv separately floato on 
the water^ hot which when attached io the black 
drosses, is carried by their gravity to the bottom: 
this is the first instance known of Etna having 
produced a similar mbsfeance. 

" Found on the W. S. W. torrent of lava, near 
the crater, 

2dS 



t>OMAIH XII. . TOLGAJIIC. 



'< No. IV. Light drosses m separate pieces j 
the largest are ten inches long, one in widths 
and two in breadth i from this size they dimi* 
nish to that of a pigeon Vegg ; their pores are 
rounded, glossy, vitrified, and of a pitch black ; 
some of them seem to be damp as soot 3 seen 
through a magnifying*glas$, they appear a real 
vitrifaction, porous, and of a greenish colour. 

*' These drosses are found at a greater distance 
from the crater than the former ; some even as 
far from it as six miles. 
Sand. '* No. V. A very fine and shining sand, which, 

seen through a microscope, is found to be com- 
posed of grains of volcanic chrysolites, trans- 
parent,, and of a golden gre^,. and greenish 
colour.^ Among the sand also are fragments of 
transparent quartis, and laminated felspar. 

>/' Sand of this description fell at Catania^ on 
the 16th of July. 

'< No. VI. Light sand, formed of small grains 
and filaments of a glossy vitrifietction, analogous 
to the drosses No. ly. 

^^ This sand fell in every part of the second 
region ; and on the confines of the first, from the 
eastward to the south and south-east, on the 
18th of Jyly ; it is mingled with fragments of 
the drosses before noticed. 

'' No. VIL Pu2zolana composed half of cry s* 



VOMB IV. TUVO. 



40^ 



tals of black schorl^ which have received a kind 
of varnish from fire ; of fragments of drosses 
such as described No. III. ; of chrysolites^ some 
yellow and transparent, and others opake and of 
dull green colour at their edges ^ of small crys- 
tals of white felspar in rhomboidal laminae, some 
detached, others united together, and grouped 
with crystals of schorl, some of them superficial- 
ly; vitrified. The crystals of schorl preserve 
almost perfectly their natural figure: they are 
chiefly detached in octagonal prisms, somewhat 
compressed, and with two broad and one nar-^ 
row side, terminated by a dyedral summit with 
hexagonal faces; they -present some slight 
varieties. 

'^ This matter, which fell on the 19th of July, 
did not extend 'beyond the middle region, where 
it spread from the S. £. by S. to the S. W. 
wherever the watery cloud mixed with the smoke 
which contained it was carried, and from which 
it was precipitated by the rain. 

" No. VIII. Pieces of lava tolerably compact, 
of an oval or wedge-shaped form, fi*om two or 
three to twelve indhes in length, and from one to 
sixiinches in thickness ; the surface vitrified, and 
exhibitiifg small pores ; their interior similar to 
that of No. II. They resemble pebbles rounded 
by water, and are remarkable among the drosses, 



Pebbles of 
lava. 



40$ DOMAnr SII. VOLCAHIC. 

dmid which they are found, on account 6f th^ir 
singuUr shape. 

" They are collected on the cone of Etna^ 
lying among light drosses. 

'^ No. IX. Other pieces of the same form, 
but more compact : the surface of these is more 
limooth, ahd is sprinkled with- white spots, which 
s6em produced by the vitrifaction of the felspar; 
the internal part of these pieces assimilates with 
obsidian. 

'* These are found in the same place as the 
last. 

*• No. X. Oval pieces, nearly two inches in 
length, ccnnpbsed of two parts of white felspar 
transparent and glazed, some yellow chrysolites, 
and some prismatic crystals of black schorl ; the 
surface of this specimen was changed by fire, 
which had chiefly affected the schorl, occasion- 
ing it to lose its angles. 

*' Found near the crater. 

*' No. XI. A compound stone, divisible in 
parts, with a vitreous incrustation : one portion 
exactly resembling lava^ which elicits sparks 
when struck with steel; the laminse are distin- 
guished, one from the other by their different 
. colours, the result of a calcination which has 
acted differently on the rarious component mat- 
ters ; in it mica and felspar are found in an un* 



alteradpMe. in bnt of tii^ ]Mmmb wk^ oly$laBh 
of prismatic schorl ; and: is. all the Miities b a 
white fibrous radiating ftmktfflr, which I €oa6eive 
to he asbestos in a ohangled cottdltioii, owing to 
the action of fire. 

^« It is found on the carrrot of lava^ at the foot 
of the cone. 

« No. XII. A grey lava with earthy grains^ i*m. 
which) notwithstanding, yields sparks with steel ; 
its base is composed of a great number of points 
and lamins of fblspar, with sofaie crystals of 
Mack vitf^ous and prismatic schorl, and a fe« 
grains of greenish chrysolite ; this IaTa> on being 
moistened^ yields a smell like day^ as also do 
the two following lavas. 

<^ It ia a fwult of the lesser eniptioa towards 
the south. 

*^ Ka XIIL Conspaot lava riiawing a vitifeoos 
fracture, the base at wUch consists of smatt 
sbining points^ resettibling talc, mingled wHh 
diminotive lamellie of white felspar, and sdaie 
chrysolites of a diirll green colour : ikh speciascii 
was apparently fissile. 

^ This proceeds from the same eruption. 

« No. XIV. A lava of a dark grey colour, of ^ 
tbe same specice as the foregoing; it is of 
roogher grain^ and tk|e talc slill pnserring Hi 



40^ BOMAtw xn. ToftCAine. 

ludtt^ .has beoofme aggliitiiialedy and .compimBe4t 
by it kind of calcinataoh. 

<^ Its origin similar to the last. 

«'No.XV. A black la^a with a base of febpar 
and chrysolite, to which fire has impartiad ^jtif*. 
ftrent colours ; it comprehends rhomboidal crys- 
tals of felspar, and crystals of vitreous schorl* 
and mica. 

^' From the eruption of the west-south*w6rt» * 

** No. XVI. Lava in beds of different suIk 
stances : one of them is compact, very hard, of a 
fine grain, with laminsB of Mspar ; the other has 
regular pores, with laminas of felspar which 
cross each other, and vitrified grains of a green* 
ish hue and semi-transpar^it ; this lava, on 
being moistened, yields a strong smell like 
clay. 

<^ It is a product of the same eruption as the 
Java of the preceding article. 

<' No. XVII. A compact and very hard lava^ 
with a vitreous fi*acture ; its black base contains 
small laminae of felspar, with a few ciystak of 
vitreous schorl. 

<< From the same current of lava as the pre^ 
ceding. 

<< No. XVIII. A very hard bsA compact lava. 
Mack, and sprinkled with points varying in sise^ 



Horn IT. 9*VfO» 400 

formed by a Unck shining glasB^ which still re-, 
tains the figure of the crystals of schorl contam* 
ed in the base, which was on the point of fusing 
into a state of homogenous glass. 

*^ From the same eruption. 
'' -^^ No. XIX. A dark grey lava of a rugged 
fracture, the base of which contains similav 
scales of talc as No. XIII. and No. XIV. with 
scAne laminae of felspar faintly apparent. 

^' Foond in large oval masses ejected by th^ 
volcano. . . 

^ No. XX. A porous lava, of similar nature 
to the preceding, with a stratum of vitrifaction,' 
mingled with laminas of mica> radiantly disposed. 
From the same. 

*< No. XXI. A species of stalactite, or coa« 
cretion, found under the preceding lavas ; it pre- 
sents three varieties : 

«^ 1. With a friable base, and lamino appa- 
rently of mica. 

^^ SL With a coating of silvery talc. 

^^ 9. With a coating two lines in thidcness^ 
consisting of a white powder, which is salt of 
Sedlitz, deprived of its water of crystallisa- 
tion. 

f* No. XXII. An incrustation of selenite, of a 
mingled white and red colour, in thin strata. 



410 BOMAIV YII. VttUSikiriC. 

'forming a coatiag of two liDes m tbickti€iB4« ^n 
.W'bich ara small graua of a aimtlar nature*. 

«< Foond io tbe fissurea of the w. a. w. cuf* 
rent of lava. 

*' No. XXIII. Deliquescent sea-salt with a 
martial basis, which flows from tho^e light drosses 
iHiich are of a reddish yellow colour. 

<^ From tbe same fissures. 

<« No. XXIV. Martial yitriol adhering to 
mUij of the preceding drosses, now of a lively 
red, now of a greenish yellow, and now of other 
colours: these droases remain yet partially co- 
Tfired with the sdenita of No. XXII. 
. ^* From the same spots as the iast : in tlie 
eruption of this w. s. w* current it was very 
abundant 

** No, XXV. Martial aal ammoniac, suUi« 
mated in very thin needles, two or three Hues in 
loigth, and adherent to a light cellular HvA of a 
reddish yellow colour: on examining these 
needles with a microscope, small articuUtions 
ate clearly distinguished, composed of octaedra^ 
placed one on the oliier« 

r 

* '* These incrustations of selenite are found in veiy great abuiH 
dance in the two new currents of lava ; they eviiMO the prompt 
activity and powerful effect of the sulphuric acid on the calcareoua 
molecnies of lava^ especialty when assisted hf heat" 



KOM& IV. TUtO^ 41 1 

'' From the same fissures. 

" No. XXVL A hard lara, the base of which 
CK^ntains many small laminae of felspar and 
grains of volcanic chrysolite, coloured by fire^ 
and some pretty large clusters of the same kind 
of chrysolite. 

<' From the current of lava which flowed to* 
wards Bronte. 

' ^' No. XXV IL A bard, grey, anddnllish lava^ 
with abundance of laminse of felspar, of greatjsr 
snze than in the preceding specimen ; they are 
enveloped in the base of the lava, as well as 
some crystals of prismatic schorl, and some yel- 
low and greenish chrysolites. 

<< From the same stream of lava as the pre- 
ceding. 

'' The different speOimens of lava I have de- 
scribed, show us the nature of the various kinds 
of primitive stone, which constitute the base of 
Etna 3 they demonstrate also that the rocks^ ' 

which enter into the composition of these erap^ 
tions of lava, undergo little change fVom fire$ 
and that, in the last eruption, the granitoid schist 
had been chiefly attacked*. 

* *' From the indications of the Commander Oolomieu, who has 
daoaifami in the Neptiinian mou&laios (or those of Feloro) all the 
pcnmtivo lockt fbnad in the nirieus lavM evolved from Etna, I ha\-e 
myself made a large coUec(ioD of them ; these I have also cooifMred 



413 DOMAfir XII. VOX.eAKIC. 

<< From the few historical memoirs which speak 
of the eruptions of Etxia, we fiad that those which 
EraptioDsfromhav^ issued from the crater are comparatively 
&r less numerous than those which broke for 
thcsuselves n|3w orifices through the sides of the 
mountain. 

f^^The epoch of the first stream of lava that 
issued from the crater, which history has pre- 
served, is that noticed by JzUius Obsequens, whose 
testimony is corroborated by Orosius^ to have 
happened in the year 227 from the. building of 
Rome. 

^^ The second is described by Fazelliy an ocu- 
lar witness, by Philoteusj and Selvaggio ; it oc* 
curred in the year 1536. 

'* The third happened in IGO?, and is de- 
scribed by Carrera and Guarneri. 

*^,Mas$a speaks of the fourth, in the year 
1688. 

, *' Father Amico mentions the fifth, sixth, se- 
venth, and eighth, in the years 1727, 1732, 1735, 
and 1747. 

" And finally the Canon Recupero speaks of 
the ninth, which occurred in the year 1755.'* 



with the different species of lava, and suppose myself capable of 
pointing out, with the specimens in my hand^ the dififeient speciea 
to which th^ belong." 



The intelligent Ferrara has giyen a chrono- i^J^^Jtrfths 
logy of the eruptions of Etna ; but has only de» •™p^^"*^" 
scribed those of 1800 and 1809 in the following 
words: 

'< 1800. In February, the mountain ejected 
smoke, with those powders falsely called yolcanic 
cinders and ashes. During the night of the 27th, 
the inhabitants of Zafarana, situated about the 
middle of the cone, on the east, were awaked 
-with the horrible explosions of the mountain, 
and saw rising to a prodigious height immense 
ccrfumns of fire, which often sparkled with long 
and tortuous lightnings. Their summits ex- 
panded, and dropped black matter, which burst 
on the fire beneath. This phenomenon was ac- 
companied with a treme^^us roar, like that of a 
ruinous hurricane; and a strong west wind which 
'arose, bore to the east all the ejected matter, 
which formed on the lower skirts rain, sand, and 
drosses, which, rustling as they fell^ occasioned 
a singular and horrible noise. They deposited a 
bed half a foot thick. This phenomenon was 
repeated on the 4th of March ; the eroption of 
inflamed masses was more copious, and the 
southern wind carried the dust even to Milazzo. 
The inhabitants of the places in that direction, 
but more near the volcano, were greatly incom- 
moded with this dreadful shower. At Malvagna, 






414 DOMAIN XII. Vaf<C4NfC. * 

jgyGteen miles from ihe crater, tbe sky suddenlj 
darkened, and the people were obUg^ to Ugbt 
candles, though it wanted an hour and a half to 
sunsety as neither business nor pleasure could be 
^oUowed amidst the thick dafkneas. It seemed 
as if the darkest hour of the ntght had fallen at 
once ; and the inhabitants neithier knew where 
to flee, aor what was the cause^ as tiiey only 
he&rd a rustling murmur. This uncertainty con^ 
tiniied for twenty-five minutes ; aft^ which be* 
gan a rain of black drosses^ the largest oi wbU^ 
wene nine ounces in weight 3ttt at Moj/o aad 
BocoeUa they were of thirteen ounces ; and vaomf 
in the &eUs raeeiired wounds in tbe head and 
aims. These drosses bad so much heated the 

4 

atmosphere, that a ^iigpiions fall <tf irainrwater, 
which accompanied thenit was quite hot 

*' The enipti(m was often repeated in tbe IbL- 
iowing months; and the grandeur of the scene was 
increased by frequent forked lightnings, which 
broke fortii in the midst of the black smoke, 
having coflamonly one line perpendicular to the 
axis of the cone of the craler, while at the other 
extremity another nose at right angles, and was 
lost amidst the smidke and the iames. This long 
eruption ended in July ; having formed on all 
the upper part of tbe mountain a stratom df 
mttny feet of light dmsasa, iota which fom ihe 



vojiB IV, Tm«; 4]^ 

fara hftd been reduced bjr l;he inteBse heat and 
fermentaiioa. 

<< 1802. An eruption from a neiv apertui^y a 
Iktle under the crater^ in tbe great valley of 
3U69 accompanied with horrid thunders aUd 
tmmendoQs bellowings of the tnountiUh. It 
ceaied in a few daysj but the lava ran twelve 
miles. 

^« I8O9. After the volcano had> in 1805 -and 
1606, ejected flames and copious smoke, at un^* 
iB^pial intervals, daring which some undulating 
shakes were observable, chiefly in the skirts, 
and alter a perfect calm in 1 807i during which 
I ofbm descended to the bottom of tbe cmtof , 
and to spots before inaccessible; in 180i, the 
frequent eruptions of flame returned, the most 
copious being always preceded by prodigious 
bellowings of the mouDtain, and subtemineous 
^thunders, ntM; ivitbout some shocks sensibly Mt 
even at Catania. These having continued tiH 
March I8O93 on the 87tfa day of that month, 
after the rise of immense perpendicular colmmis 
nf -smcAe, was opened a new orifice, a little andcr 
the crater towards tbe v. w.^ from which issued 
a river of fuliginous sasoioe, in the form of enor- 
mous balls, with a slow motion, as they were fidl 
of powders and sand, whiph were snatchMl by 
the wind and carried even te Messina. AAes* 



4 



rf" 



41^ DOMAIir XII. VOI.CMIC. 

wards,, in a Iine> which from the : third. 01* opok 
region of the mountain passed the woody region 
till it reached the cultivated lands .of Castiglione 
and Linguagrossa, many new orifices were opea- 
ed. One was. at six miles distance from the. first, 
fuid the others at unequal distances; while 
throughout all the space many fissures appeared 
and subsidencies of the ground. From . these 
new orifices, after they had darted immense 
clouds of dark smoke, which appeared like hor- 
rid rocks hanging in the air, and from which the 
drosses which Ml in . iron sleet, rushiog and 
dashing against each other, produced a clamour 
which filled the neighbourhood with dismay; 
on the 28th, at the approach of nighty were 
ejected torrents of lava, whilst the mountain 
suffered the most violent convubions, and r^ 
: sounded with horrible bello wings, which were 
heard even as far as Catania. The thundeos of 
these apertures were pretty frequent, and were 
repeated progressively from one to the other, till 
they reached the crater. The eruption conti- 
nued forthe remaining days of March, and the 
beginning of April, when the lava ceased; after 
having covered a space of eight miles in length» 
and four hundred and fifty feet in breadth. 
Around the two chief orifices, in which the fire 
seemed at last concentrated, were formed two 



ItOlU IT. TUFO. 417 

large conical masses of ejected matter, one of 
them having two summits. The shocks con- 
tinued to be felt in the succeeding months^ but 
' the eastern skirts toward Aci were the most agi- 
tated; and in some parts it appeared as if the 
subterranean winds aiid vapours would have 
opened new apertures, struggling as it were to 
get loose ; while on the same spots long fissures 
appeared, occasioned by the sinking of 'the 
ground. But the oircle of these great agents of 
nature seems to have been confined by ' the 
mountain; for, in the following months, the 
shocks arrived at Catania with an unduktion 
which was evidently occasioned by a shock 
from the north to the south: and afterwards, 
while Etna remained perfectly quiet, these un- 
dulations violently and repeatedly shook many 
places of the southern part of Sicily, called Val- 
dinotO; and have continued, with still more 
force and frequency, in the present year 1810." 

To return to a more immediate consideration 
of tufo, as connected with the present design, 
this important substance maybe arranged under 
the following divisions : 



VOL. II. 2 £ 



\ 



41$ DOMAnr xtu yotcMtSic, 



BYPOKOMB I. fiAftD TltFO« 

Hus has often the appearance of a grey argil- 
laceous stone, and is used for building in various 
narts of Italy. It is generally grey and porous, 
and sometimes contains small leucites, whence 
this kind is called partridge-eyed tufo"*. It may 
also embraoe fragments q£ granite; but when 
these are numerous, and joined with fragments of 
marble and other substances, it assumes the name 
of peperinOy which is a volcanic bricia, or glu- 
tenita . 

Micronome 1. Of Clay^ Sand^ Powdery Pu- 
mice J ^c* 

This is the most usual form of tufo ; but the 
clay seeois to be chiefly inserted by the infiltra* 
tion of the waters from superior soils and emi- 
nences. 

Tufo, from Herculaneum^ Pompeia, Iceland, 
&c. &c» 

Hard tufoi from Mont Anis and PaUgnac/in 
Auvergne^ where it is used £ar buildiog* 

* Fatrin, v.* 99s. Hie isk Ventotiene (Dd. PoBoes, 41) con- 
Mts almost entirely of a yolcanic tofo^ a soft stone with an aigil- 
laceoQS base, iBcludiDg fragments of lava, slags, pumice, &c. 



HOlCfi IV. TOM. * 4l9 

The same, with bitumen and chalcedony, from 
Clermont 

Micramme 2. Of Drossy and putoerUtd Lwoa. 

Th)s, in the course of age^, assumes consider- # 
able hardness, while it shews its origin by ' ;; 
black colour, arising from the drosses or scoria ; 
the latter are sometimes red from calcination, 
whence seems to arise the name of Monte Rosso, 
ejected by Etna in the terrible eruption of 1669 ; 
but th^ surface at least is chiefly incoherent Thia 
tufo in particular sometimes aflfects tiie magnetic 
needle. Black tufo sometimes resembles wacken. 

A tufo of fragments of laya, droeses, sand, 
augite, and conchitic limestone, in a paste of 
marl. Ferrara, p. 67 • 

Mtcrtmome 3. Withfragments of Granite^ or 
other substances. 

When these are numerous and dosely set, the 
stone becomes a volcanic glutenite ; but they are 
sometimes rare and i^mote. 

A tufo of lava and limestone, fitnn Cape Pm* 
saro and the rocks of the Cyclops, Sicily*. 

• FttT. 181. 



S £ S 



420 OOMAm XII. VOJICAIIIC. 



HTPONOMS II. SpPT TUfO. 

This is either found in an incoherent form, or 
easily crumbles into small fragments. When it 
chi^y consists of comminuted pumice it is called, 
upiOo. in its recent state, lapilla or rapillo; and some* 
times, though improperly, white puzzolana; for 
the absence of iron must render it unfit to be used 
as' a cement, which is the chief quality of puzzo- 
lana. It sometimes consists of minute scorie, or 
dross, in which case it is called black puzzolana ; 
and at Naples a rapUio; now constituting, ac- 
cording to Dolomieu, almost all the mountains 
around Etna, with nme-tenths of that mountain 
itself* 

The proper puztolana, also called Trass or 
Tarras, which is used to consolidate buildings 
under water, is a ferruginous clay, of a grey, 
brown, or reddish colour ; and is more likely than 
any of the others to be a muddy ejection from the 
Tolcanoes. 

' * Dolomiea^ Etna, 3ft3> 388. Volcanic scoriae^ ISce tlioie of a 
smithy, or more porous, form all the conic moui^ins around £tna^ 
and perhaps nine-tenths of its mass. At Naples they are called 
rtqnllo. (Dol. Etna, p. 388.) They are of the nature of kva ; 
while puzzolana is burnt day. Ferrara, a superior judge, denies 
the extent of the tnfot, and says they do not form one half of Etna : 
p. 336. 



NOSB IT. TUro. 



421 



Microname 1. White Tufo. 

This ccxisists, as already meiitionedy of commi- 
Quted pumice, and often presents larger fragments 
of that stone. It may, from the yarious influence 
of the waters, be indiirated in some paits, and in- 
coherent in others. 

Microname 2. Black and red Tufo. 

Tufo, of comminuted black dross, from the 
mountains of Iceland. 

The same, from Etna, and its filial hills. 

Tufo of small red scoriae, from Monte Rosso. 
This mountain, chiefly formed of volcanic sand, is 
1000 feet in height 



Micronome 3. Tarras or Puzzolana. 
This is chiefly a ferruginous clay, as already 
explained ; but ferrugmous tufos in general may 
'■ be applied to the same purposes, l^ie tarras 
found near the Rhine is of the same nature and 
quality ; and is supposed, by impartial authors, to 
be of volcanic o^gi^- A more candid and equita- 
ble judge cannot be invoked than the patient and 
experimental Saussure, who not only allows the 
mountain of Chenevari, and some others in the 
south of France, to be of volcanic origin ; but 
has also published an interesuling account of bis 



Turn. 



? < 



4SS OOIUIV SLII. VMCANIO. 

journey to the extinct volcanoes in the Brisgaw, 
being in the Black Forest adjacent to the Rhine*. 

Puzzolana forms a remarkable feature of several 

• 

extinct volcanoes ; but Mr. Kirwan, who has an 
inconceivable averuon for those grand phenomena, 
often passcis in silence the most cogent authorities 
against his system, and argues that tarras is of a 
pseudo- volcanic origin. Yet his accounts of these 
two substances, so useful to the arts, and esper 
cially to a maritime people, are more carefully 
composed than those of any other writer, and de? 
serve transcription. 

Kirwairt f* PUZZOLANA, 

account 

** Reddish, or reddish brown; grey, or greyish 
black. That of Naples is generally grey ; that of 
Civita Vecchia more generally reddish, or reddish 
brown. Dolomieu*s notes, 33. 

^^ Its surface rough, uneven, and of a baked 
appearance. It comes to us in pieces of from the 
size of a nut to that of an egg. 

** Its internal lustre, 0. Its transparency, 0. 

" Its fracture uneven, or earthy, and porous j 
commonly filled with particles of pumice, quarte/' 
scoriae, &c* 

** Hardness, S. Very brittle. Sp. gr. from 

t Joonial de Rornqoc Nev^ Series, ^niL L 



v 



%r 



mua lyj tuso* 



4SS 



A^70, which m that of. the Uack, to fl^78if, rarely 
fiy^. .H9S an earthy dmelL 

'' It is not diffusiUe in. odd water ; but in heal* 
ing water it gradually depositee a fine earth. It 
does not effervesee with acids. 

^^ Heated, it assumes a darker colour, and 
easily nielts into a black slag; or, with borax, 
into a yellowish green glass. 

'^ It B magnetic before it is heated, but not 
laiter. This is the most remarkable of its pro^ 
perties. 

^^ By Mr. Bergman's analysis, it contains from 
55 to 60 per cent of silex, I9 to SO of arg^, 5 or 
6 of lime, and from 15 to 80 of iron. 3 Bergm. 

p. id4. » 

^^ When mixed with a small proportion of lime 
it quickly hardens, and this induration takes place 
even under water. This singular .property ap- 
pears to me to proceed from the magnetic state of 
the iron it contains ; for this iron being unoxygen- 
ated, subtilly divided, and dispersed through the 
whole mass, and thus offering a large surface, 
"' quickly decomposes the water with which it is 
mixed when made into mortar, and forms a hard 
substance analogous to the specular iron ore ; as 
it does in the iron tubes, in which water is de- 
composed, in Mr. Lavoisier's and Dr. Priestley's 
experiments. For in these the iron swells and in-* 



424 ooMAn .xu. voLeAinc. 

creases in bulk. Menu Par.. 1781, p* 277: and so 

does puzzolana when formed into mortar, Higgins 

on Cemrats, 1S5. One principal use of lime 

seems to be to heat the water, as while cold it 

cannot readily pervade the caked ar^ that invests 

the.ferru^nous particles; yet, in time, even cold 

^vater may pervade it, and produce hardness ; and 

hence lavas become harder when mobtened, as 

M. Dolomieu has observed. Ponces, 417. If 

the mortar be long exposed jlto the atmosphere^ 

fixed air, as well as pure air, will unite to the iron^ 

rust will be produced, and the mortar will not 

then ,harden, as Dr. Hig^s has also noticed. 

Clay, pvier which lava has flowed, is fiequently 

converted into puzzolana,J?onces, 332. But vol* 

canic scoriae never afford it ; ibid ; either because 

they are much calcined, or retain sulphur, or its 

acid." 

" TRASS OR TARRAS. 

' " I couple this with puzzolana, on account of * 
their similarity to each other, and hot because I 
look upon it as constantly, and necessarily, a vcd-^ >^ 
canic production. On the contrary, I believe it 
to be generally the product of pseudo-volcanoes, 
pr external fires. 

'^ It is found in many places, but principally 
near And^rnachi in (he vicinity, of the Rhine ; alsa 



•/ 



■ « • 



' r 



Hoiis IT. ' Tupo. 425 

near Frankfort^ Cologne, Pldtb, &c. and there 
called tuffstan. 

" Its colour is grey, brown, or yellowish. 

^^ Its sur&ce rough and porous. 

'* Its lustre and transparency, 0. 

'^ Its fracture, commonly earthy, rarely lamel- 
lar; it contains fragments resembling pumice 
(though not real pumice, Voigt FuMa^ SSI) ; cdso 
^ fragments of argillite and basaltin (siderite) ; often 
branches of trees half cleared, and impressions of 
leaves, 2 Nose, 182. Mica, iron ore, and other 
heterogeneities, are more frequent in it than in 
puzzolana, 3 Bergm. 1^6. 

'^ Its hardness from 5 to 7. 

^^ Feels dry and hanrii. Scarcely efferves'ces 
with acids. • 

'^ It is not difiusible in cold water ; but in hot" 
it gives an earthy smell, and deposites a finer 
earth. 

^^ It melts into a greyish brown slag. 

^- It is found in valleys, some feet under the 
surface, to which no .|treams of water have had 
access. Sbmetimes in columnar masses of a grey, 
or Isabella yellow colour, some round and some 
quadrangular, standing close to each othef, and 
forming^ internally one common mass. 3 Berl. 
Beob. 199. 
^' '^ According to Mr. Bergman, it consists of 






4S6 



BOKAUr XII.' VOtetHIC. 



nearly the same principles as puzzolana, only the 
calcareous seems more plentiful in this. 

*^ Artificial tarras, or puzzdaha, is made by 
burning clays or slates that abound in iron, and 
then grinding them to a fine powder."* 
ot irekod. A red substance is found in the north of Ireland, 
particularly in Lord Antrim's Deer-park, near 
Glenarne, which has a burnt appearance, and 
much resembles the puzzolana of the extinct vol* 
canoes of France. It might perhaps be applied 
to architectural purposes. Faujas, who rendered 
a serviee to his country in discovering the puzzo- 
lanas of Vivarais, gives the 'following observa- 
tionsf. 

'^ Puzzolanas are ah object of ^e first utility in 
hydraulic constructions. We cannot build with 
^solidity in the sea, without using this volcanic pro* 
duction, by. mixing it with two portions of lime to 
one of this natural cement, of which a well-united 
mortar is fisrmed. Vitruvius has, in his architec- 
ture, devoted a chapter to the origb of this sub- 
stance, and the property it^possesses of hardening 
very soon in sea-water, as well as fresh, when it 
has been amalgamated with strong lime ; it then 



Uses of 



* Kirwan, Min. i. 411. 

f Annales du Museum . It is truly surprising that he has omitted 
this important article in his large Classification of Volcanio Sob- 
ftanccs. GeologU, tome ii. p. 401-r678. 



MOMM IV, TUfO. 

perfectly resists the corrosive action of marine 
salt 

" TTiere are in Vivarais, Velay, as well as in 
Auvergne, as good mines of puzzolana as those 
of Italy ; and yet we still use the puzzolana of the 
^virons of Naples : which shows that much time 
la necessary to change the customs of meui eveQ 
Ux the most simple things. 

^^ The trass of the environs of Andemach, on 
the left bank of the Rhine, is a kind of puz^olan^ 
formed of small fragments of pumice, and several 
upecies of lavas, more or less altered and (^lu* 
^ tioated in the mann^ of volcanic tufos*. Trass 
IS transported by water as far as Dort, to be re* 
duced to powder in stamping mills worked hy the 
wind. Trass, thus pulverised, circulates through- 
out Holland ; and is used with the greatest sue* 
tQess for all constructions in masonry, in a country 
where water is every where found in digging the 
earth: the Dutch also supply En^and with 
trass." 



4S7 



^ *' I have gimi the description of the quarries of trass in tha 
iint number o(AfmaU$ du Muteum, vol. i.'* 



S" 



4S8 DOMAIV XII« VOLCANIC 



NOME V. PUMICE. 

Fonner rocks. This substance deserves to be ranged among 
the rocks^ as in the isle of Lipari> whence it is 
chiefly brought into commerce, it appears in the 
form of large currents*. Pumice also-abounds 
at the smaller volcanoes of the isles of Santarin 
and Vulcano: and, according to Troil, Hecia 
presents vast quantities of brown and black 
pumice. The volcanoes of Temate, and other 
Molucca isles, also eject s^ph prodigious quan- . 
tities of this substance that the ocean appears 
covered for many leagues. 

cueayUHtpu. Different lavas may become pumice by some 
peculiar .modification of the volcanic agents. 
Felspar in particular has been detected passing 
into pumice: and according to the degrees of 
heat and other circumstances^ it may be more or 
less porous and lightf . That which only pre« 
sents small cavities may be termed porous; 
while the more lax may be styled vesicular. 

* P^itruiy ▼• 9SQ, from Dolomieu's Upari. 

f Fecrara, p. 3(Hy mentions a laige specimen Reeled by Etna in 
18p2, of which one half was lava, or melted siderite, the other 
pumice or melted fekpar. See also hb account of the pumices of 
Ijiparij p. 215, *" , 



' MOMB ▼• PVmCE. 489 

In his Tisit to the little isle of lipari, which, ^^^^ ^ 
though only sizmiles in length andfour in breadth, 
is singularly interesting from the. pumices, and 
great variety of volcanic glasses of ail kinds 
and colours, which it contains, Spallanzani has 
minutely described this substance ; and the spot 
ivhence it is exported to all parts of Europe, as 
It is useful in many of the arts. On such occa- 
sions, the words of the original observer are to 
be preferred, not only for the sake of accuracy, 
but because the impressions of the scene are 
best conveyed by a spectator ; not to add that 
they diversify the style, by imparting somewhat 
of a dramatic interest to the narrative. 

*' I had now continued my tour in the boat, 
till I approached Campo Bianco (the White 
Field), distant three miles from the haven of 
Lipari, and so called because it is a lofty and 
extensive mountain,, composed entirely of white 
pumices. When seen at a distance, it excites 
the idea that it is covered with snow from the 
summit to the foot Almost all the pumices 
that are employed for various purposes in 
Europe, are brought from this immense mine ; 
and Italian, French, and other vesseb continual- 
ly repair hither to take in cargoes of this c<«n- 
modity: the captain of the ship which had 
brought me to Lipari, had sailed from Marseilles 



430 DOtfAtIf til. VMCAKtC. 



to carry back a freight of this mftrchatidtse. I 
was not, however, actuated mefely by tboBi 
motives of curiosity that might induce any tra* 
veller to visit this remarkable mountain ; I pr6« 
posed to examine it with the eye of a philoBO^ 
pher and a naturalist 
Ongiiu << The pumice-stone» with respect to its origin^ 
though universally admitted to be the product of 
fire, is one of those bodies which have divided 
the opinions of the chemiMs and naturalists both 
ancient and modern. It may, in fact, be a^ 
firmed that it has given rise to as many hypo^ 
theses and extravagant suppositions, as the 
question formerly so much agitated relative to 
the nature of the yellow and grey amber. With- 
out noticing the more absurd of these, I shall 
only mention that Pott, Bergman, and Demeste 
• imagined that pumices were amiauthuses deconn 
posed by fire; Wallerius, that they were coal 
or schistus calcined ; Sage, that they were sco* 
rified marls ; atiid lastly, the Commendator Do* 
lomieu, that they were granites rendered tume- 
fied and fibrous by the action of the fit^ and 
aeriform substances. 

" The most effectual method to investigate the 
truth in so obscure a question, appeared to nie 
to make the most accurate and minute observa- 
tions on the spot; to collect and attentively 



A. 



asamine the pumices most siitable to this pmr^ 
pose^ and to make further exp^imeots on them^ 
after my return to Pavia ; which practice I like* 
wise observed with respect to the other Tolcauic . 
products. 
•«< OHpipo Bianco is a mountain that rises al- Homitainor 

Hmt pumice. 

mo^ p^endicularly from the sea^ and which 
seen at a distance appears to be about a quarter 
of a mile in lieight, and abote half a mile in 
breadth* No plants grow on it» except a few 
which bear no fndt, and likewise grow on the 
tops of the Alps. Its sides are streaked with a 
great number of furrows^ *that grow deeper and 
wider as they approach the bottom, and have 
been formed by ^e rains^ which easily corrode 
and excavate a substance so soft and yielding as 
pumice. The sea at the foot of it has Kkewise 
occasioned gmat devastations^ by means of 
irhkh we discovered a large vein of horizontid 
lava, on which the last waves die away whea 
the sea becomes calm. The formation of this 
lava was, therefore, prior to the vast accumula* 
tion of pumices which rest upon it. 
. •< On attentively viewing this prodigious masii inbe<b. 
of pumice, we soon perceive that it is not one 
solid whole, and forming only one solid single 
piece ; but that it is an aggregation of numerous 
beds or strata of pumices, successively placed on 



■4- 

432 DOMAIV XII. . TOLCAHIC. 

each other ; which beds are distinguidhable by 
their colour, and in many places project from 
the mountain. They are almost all disposed 
horizontally, and their position is not dissimilar 
to the stratifications so frequently met with in 
calcareous mountains. Each bed of • jramice 
does not form a distinct whole, whi^^mjght 
lead us to suppose that they had flowed at dif- 
ferent intervals, and every current produced a 
bed or stratum ; but it consists of an aggregate 
of balls of pumice united together, but without 
adhesion. It is hence evident that the pumices 
were thrown out by the volcano in a state of 
fusion; and took a globose form in the air, which 
they preserved at the time of their sudden con- 
gelation. We find many such eruptions of pu« 
mices in the Phlegrean Fields ; as, for example^ 
that which overwhelmed and buried the unfor- 
tunate town of Pompeii. The excavations which 
have been made to exhibit to view some parts of 
that city, manifestly show, that repeated ejec- 
tions of small pumices in immense quantities 
from Vesuvius, have covered it with vast accu* 
mulations of that substance, disposed in different 
beds or strata. 

^* A great quantity of these Liparese pumicest 
of a globular form, are first met with on the 
shore near Campo Bianco^ but as I doubted 



.< 



HOME V. FUMICS. 433 

whethef the action of the waves might not con<* 
cnr to produce the roundness of their figure, I 
rather chose to make my observations on those 
that actually formed the beds; which I did, by 
climbing up one of the sides where the ascent, 
though difficult, was not impracticable. Here 
I found pumices approaching, some more some 
less, to the globular form ; and of different sizes. Globular, 
some not being larger than nuts; and others a 
foot or more in diameter, with innumerable sizes 
between these extremes. Though the ground 
colour of them all is white, in some it inclines 
to yellow, and in others to grey. They swim in 
water, do not give sparks with steel, nor cause 
the least motion in the magnetic needle. Their 
fracture is dry and rough to the touch ; their 
angles and thinner parts are slightly transparent ; 
and their texture in all of them, when viewed 
through the lens, appears vitreous; but this 
texture has diversiti^, whit^h it*wili be proper to 
specify. 

<< Some of these pumices are so compact that Co ict 
the smallest pore is not visible to the eye ; nor 
do they exhibit the least trace of a filamentous 
nature. When viewed through a lens with a 
strong light, they appc. r an irregular accumu- 
lation of small flakes of ice ; their compactness, 

VOL. II. S F . 



454 DOMAiK'kn. .voccAvia 

howererv does .not prevtot their swiikuliing An 
the water; 

poroiM. ^' Others are full of pores' and vacuities of a 
larger size, usually of a round figure $ and their 
texture is formed by filaments and strides, in 
geiieral parallel to each others of a shining silver 
whiteness; and which, at first view, might seem 
to be silken, did* they not present' to the touch 
the usual roughness of the pumice. 

''These varieties are not only observable in 
di£ferent globes of pumice, but frequently in the 
same 3 it is therefore indnbitable that these dif* 
ferences are not intrinsical and i essential to the 
nature .off piunices; but accidentaU and arising 
fix>m: the. action of aeri£brm fluids^ which dilsiting 
tiieu in many 'piaoes, when they were in, a stat0 
of fusion^ halve produced that.multitikde of pore^^ 
and those filaments ' and subtile^ streaks ! that 4e^ 
note a .s^mration of^tbe pi^rts; whereas Che 
odier puipices, whic^iiaiie, not been acted on by 
these gases, have preserved that compactaest 
which resttk$> firom the force of aggrtgatioDi; 

Fhicture. . '* The fraoturcsof the compact^pumices are; 
in some places, shaded with a blackish vbot at 
Uxe .same time shining tinge ; which» tvheii oare^ 
fully examined, is found ; to be censed by a 
greater, though still -a very flii|[ht,l degree of vi- 



trifioation Qf the putnice itself; either because, 
the fire has there acted with somewhat mare 
force, or because the parts were there more 
easily vitrifiable. ' * 

'* The putnices hitherto (described^ form one 
of the species which the lApe^i^e^t sell to foreign 
traders. 

•^ None of these, so far as can-bediicirned by 
the eye, or even tvith the a$sii3tan4ce of this lens^ 
eontalii 'any extraneous' bodies } but were we tod 
hasti^ to conclude that they really do not, we 
shdukl oommit an error, as thcfif Tiftrificatioft by 
artificial means will prove. When kept in the 
furaaee during an hour, they become only more Efi^ts of bett. 
friable and of a reddish yellow colour; but when 
continued in the same heat for a longer time, 
they 'Condense into a vitreous and semttrans*' 
patesft mass, Mrithih which .ap|>iear a ntnnber df 
small white felspar orystald^ thAt were not vii^i^ 
ble in the pumice, because tl^y were »f the 
same colour* . These stones, however, are not 
seen In^evcffypdnri^e thus fused; eithier because 
it did »M contalin if heffii^ or' because they have 
Bftetted into one .homdg^ndils ibass with the pd^ 
taicei This is on^of the many itnpoKHMit' cas^ 
in which we are Sble, by tiie m^ans of common 
fire, to discover jthe composition of volcanic 

^ 2f2 



n 



436 DOMAIW m. YOLCAVTC. 

products, which had at first been supposed to be 
simple. 

*^ But to render complete my enquiries rela- 
tive to the pumices of Campo Bianco, it was 
necessary that I should not confine my re- 
searches merely to the part of the mountain I 
have mentioned, but extend them to all the 
principal places where they might be found. 
This I did, accompanied by two natives of 
Lipari, whose assistance was particularly useful 
to me, as they lived by digging pumice, and 
were well acquainted with every part of the 
mountain, and the different kinds of pumices it 
contained. It is impossible to describe the dif- 
ficulties I met with in these excursions. We 
!requ^tly passed along the edges of the deep 
ditches made by the rain-water, at the hazard, 
in case of a false step, of falling into them, and 
not easily getting out again ; or the still greater 
danger of precipitating into the sea. The daz- 
zling whiteness of the pumice, equal to that of 
snow, increased my fears; for I made my .ex- 
cursions in the day time, injien the sun shone, 
and was strongly reflected by these stones. 
Every one knows that snow, besides dazzling 
the sight, is accompanied with the inconve^ 
nience, when it is deep and has lately fallen. 



I 



NOMB V. PUMICB. 437 

that the person who walks oh it sinks into it to 
a greater or less depth : and the same inconve- 
nience IS experienced from the pumice, which in 
many parts of Campo Bianco is reduced to a 
powder several feet deep, and, when the wind 
blows on it, • sinks in on one side, and is heaped 
up on the other. All these difficulties and ob- 
stacles I however surmounted, animated by that 
ardour which inspires the philosophical traveller, 
and enables him to brave the greiatest dangers, 
and such as can only be known and appreciated 
by those who have engaged in similar under- 
takings. I can affirm, therefore, with great sa- 
tisfaction, that with the assistance and guidance 
of the two Liparese, there was no corner of the 
inountain that I did not visit; and when I 
reached the summit, and saw that it joined an- 
other mountain, the foot of which was in the sea, 
and which was in like manner composed of pu- 
mice, I extended my researches to that likewise, 
and examined the different species of pumice it 
afforded, or rather which compose a very consi- 
derable part of it. I shall proceed to describe 
them severally, with as much brevity as pos- 
sible. 

" I shall first mention those which constitute Varieto. 
a branch of comn^erce at Lipari, and are applied 
to various purposes. One of these has already 



438 DQiaill XII. VQLC4NIC. 

been sufficiently described: I shall pnty add, 
•that it is £>und in. considerable quantities in 
Campo Bianco i bnt solely in detached pieces, 
and not forming currents or veins; whence it is 
evident that it h^ been ejected from the volcanp, 
and has not flo^wed in the manner of lava. 

^' The second species is cut by the labourers 
in parallelopipedsy about twenty-two inches long 
and eight broad. ^ This pumice is of a dark dirty 
colour, contains no extraneous bodies^ gives a few 
spaiics mrith steely and is so light that some pieces 
of it will float on th^ water. * It is formed by 
agglomeration<of pumicepusbubblest which are^ 
as it'W|3re, conglutinated together^ and incline 
more or less to an oblong figure. To detail 
their various sides' would be useless prolixity. .1 
shall only say, that from the very minute and, if 
I may so term them, infinitesimal, they increase 
in size till some >of them exceed an inch in dia- 
meter, though thQi latter are less numerous than 
the former. They are all extremely friable, as 
their sides are very thin, and always, semi-^vitre- 
ous. The glass of many of them is white, and 
has. some transparency; but in others is dull^ 
and almost entirely opake. 

*' As I do not know that this species of pu- 
mice has ever been described ^before, though it 
certainly well deserves attention, I would wish 



my description <. to. be as clear and explicit an 
possible, ' It has. been, already. jaid^ that many 
Ulwbs, andt. other volcanic psoductions, on re- ' 
fasioHj become cellular. To apply this to • 'the 
pumice in question^ would be an error. A lava, 
which has undergone this change by the action 
of elastic gases, . continues to fi>rm one whole^ 
though interrupted by these multiplied spores* 
The pumice of which I now speak is. princin 
pally formied by anraccumulation of small vitre-' 
ons vesicles^, which attached themselves to each 
other while they we^ yet soft from the action of 
the fire ^. and which, from itheir globose figure, 
not adhering' except in a few points, have left 
many vacuities very visible in the fracture of the 
pieces. The labourers who dig these pumices, 
after they have shaped theni into parallelepipeds, 
take them on their backs and carry them down 
to the shore, where they pile them up in large 
heaps, to be ready for sale when opportunity 
sl^all offer. We are not to imagine, however, 
that this species of pumice is to be found in 
every part of the mountain : the workmen, to 
find what th^y call the vein of it, are obliged to 
makeigreatexcavations, and frequently without 
success ; which, as they tol4 .me, in this case, as 
in fishing for poral, often, depends on chancer 
When they have found the vein, they dig it, fol- 



440 DOHAIV XII. VOLCANIC. 

lowing its direction; in which laborious em* 
ployment a number of men are occupied for 
whole weeks, the vein being sometimes a hun- 
dred and fifty, two hundred, or even three hun* 
dred feet long, and large in proportion* These 
veins are called Faraglioni. I have examined 
them, and satisfied myself that the accounts I 
received were true. Pumice-dust, and large 
heaps of the first species of pumice, with some 
scattered vitrifications, usually cover these veins, 
vtrhich, when viewed with the attentive eye of 
the naturalist, give reason to believe that they 
are long tracts of pumice, which once flowed ia 
^ Cmrents. a liquid State. Their bubbles, frequently length* 
ened in the direction of the vein, seem likewise 
to prove the same. 

^^ M. Dolomieu, who first suggested that many 
pumices have flowed in currents like lavas, ob* 
served that at Campo Bianco the lighter pumices 
lie above the heavier ; in the same manlier as in 
the common currents of lava, the porous lavas 
occupy the highest place. I have certainly ob- 
served this disposition ; but sometimes it proves 
fidlacious: for if the excavation be continued 
below the vein which forms the second species 
of pumice, we frequently again find masses of 
extremely light and pulverulent pumice. 

** The first action of the fire of the furnace 



NOME v. PVMICS. 441 

thickens the Sides of the vitreous vesicles^ of the 
second species^ and diminishes the internal pores. 
A longer continued heat entirely annihilates the 
pores, and changes the pumice into a fixed, ob- 
scure, homogenous, and hard glass, which gives 
sparks plentifully with steeL 

" The third species is likewise an object of Anoflierkiod. 
traffic with the natives of the island, who dig it 
in the same places where they find 'the second ; 
and, in like manner, shape it into parallelopi- 
pedons. This is likewise an aggregate of bub- 
bles, but differing from those of the former in 
several respects. Those, as we have seen, are 
conglutinated together in some points, while 
they are separated in others, so that we can fre* 
quently detach them without breaking; while 
these, on the contrary, are so incorporated by 
different solid points, that if we attempt the se- 
paration of one, we break the others that are 
contiguous. Here the elastic gases, investing 
the pumiceous substance in several points, have 
expanded it '^n every part into tumours and 
' cavities, nearly as we see in raised and baked 
paste. It is worthy remark, that frequently 
when we break one vesicle, we meet with an- 
other within it, and concentricaL There is like- 
wise another difference between these two pu- 
mices. The vesicles of the second species 



44g DOMAIN . SII. TOLCAMIC. 

are all more or less vitrified v but* many of th^ 
third showDOsign^of Titrificatioo^ are extremely 
fridble, and of a pale red colour. 
- ^' This pttmice> though destitute of any fibrous 
texture, is specifically lighter than water. To 
obtain it» large pieces of \vhite pumice, of the 
first species, in which it is enveloped, must be 
removed ; and it commonly lies in long tracts^ 
in the direction of which its vesicles are some* 
times- lengthened, whiph may induce us to sus- 
pect that this likewise, when it was liquid^ 
formed small currents. It contains no extra- 
neous bodies. 

*^ In the furnace it condenses into an obscure 
mass of glass, almost opake, but little porous, 
and sufficiently hard to give sparks with steel. 

^^ These are the three kinds of pumice which 
the people of Lipari dig for sale. The first is 
employed in polishing different substances; and 
the other two are used in the construction of 
arched vaults, and the corners of buildings/* 

From these descriptions the following arrange- 
ment naturally arises. 

HYPONOME 1. POROUS PUMICB. 

From Lipari. It sometimes presents small 
crystals of felspar. 

Porous pumio^; fi*om Hecla. 



VOHI TI. OBSIDIAJK* 443 



HVPONOMB II. ' VB»retrLAR-PUMIC9. 

From Lipari, Santorin, Hecla> Teraate^ &o, 

Micronome 1. Fibrous Jelsite, 

This kind of pumice, described by Dolomieu, 
assumes the form of distinct elongated fibres, )Euid 
sometimes occurs with, minute crystals of felspar. 



NOME VI. iCffiSIDIAN. 

This division will include all the Volcanic 
Glasses and Amels^ ; which are nearly connect- 
ed, and often pass into each other. * < 

The volcanic glass called obsidian, appears in 
such quantities as to constitute rocks. 
• *' In the Isle of Lipari, the mountain della putriiA 
Custagna is wholly composed of glass and amels. tj«^ 
It forms a promontory which extends 800 fa* 
thoms into the sea, and which is more than SOOO 
in circumference. Spallanzani says, that this 
mass of vitrified substances cannot be better 
compared than to a great river, which, dividing 
itself into a thousand branches, should be preci- 

* See Johnson, as before mentioned : enamel is properly the ap- 
plication of the afuel to another -substance. 



444 OOMAIV ZII. TOLCAHie. 

pitated by a rapid declivity, and suddenly frozen. 
There are several currents, one above another ; 
their thickness varying, in the same current, 
from one foot to twelve. 

^' Some of these substances are compact ; 
others^ are so porous that they resemble froth, 
and float on virater. In the cavities of some are 
observed capillary threads perfectly vitrified. 

** As the volcanoes of Lipari have ceased to 
be active, even before the times of history, these 
glassy Substances must have existed more than 
3000 years ; and they have not undergone tiie 
least alteration. 

" All volcanoes do not produce these vitreous 
substances : they are extremely rare in the ejec- 
tions of Etna, as well as in most countries of 
Europe. 
VraBce. ** Faujas only found obsidian in one place in 
France 5 at Chenavari near Rochemaure, in Vi- 
varais; and there were but three pieces which 
he collected. It is an amel, perfectly black, with 
rounded vesicles of about half a line diameter, 
leeinid. ^' The volcauocs of Iceland are very prolific in 
vitreous substances; and what is improperly 
called Iceland agate, is a volcanic amel, of a fine 
black, almost free from pores, and susceptible of 
a perfect polish. 

" The piedra de Galinazzo, regarded by Cay- 



NOMlfr TX. OBSIOIAH. 



^s 



lus ds the obsidian of the ancients, is a yoloanic 
amel of the province of Quito. 

** The volcano of the isle of Bourbon piiesents Bonrboi. 
v6ry remarkable vitreous ejections: they are fila- 
ments of a flexible and yellowish glass, two or 
three feet in length, sprinkled at intervals with 
small globules. These threads of glass showed 
themselves in the eruptions of , the 14th of May 
1766, and the 17th of July 1791. In the latter, 
they were carried by the winds, and strewed 
upon the trees, to the distance of ten leagues. 

^' The ancient volcanoes of northern Asia 
have also •produced vitreous substances. Near 
the port of Okhotsic, in the gulf of Kamschatka, 
there is a volcanic hill called Marikan, formed Uaribui. 
of a white sand entirely vitreous ; and in which 
are found dispersed, globulcb of glass and vol* 
canic ameL This very remarkable sand ap* 
pears at first view to be sbdly ; for it is all com- 
pqsed of white fragments, resembling mother of 
pearl, convex on one side and concave on the 
other. These fragments proceed from the re» 
mains of a singular variety of vitreous globules : 
they are at most of the size of a pea, of a pearly 
white, perfectly spherical, and exactly like 
pearls. They are entirely composed of con- 
centric layers, as thin as the peel of .an onion, 
and which separate from each other* They are 



4 



44& BQiiipr xit. rohCMikc^ 

m 

in midiatiirek whiit baialtic balls are on a large' 
scale. These little globales are, opake^ but tibe 
coats trbioh foroKthew' are peirfeotljr transparent. 

. " TKere are kwc^ other vamties • df globoles ite 
the same ctod^ entirely .differeat from theses 
they are less r^gpularly spherical^ and bare some 
flat fiices: their, textum is )perfeQtly ^olidi and 
compdict, aii4 theif* firaoture ivitreous. - 

. ^* Some «ie of a white and transparent glaas» 
which seems free from bubbles: their sioe does 
not exceed that of * a hazel-ntitk . 

^'The others are opdce» ^and formed of an 
amel mottled with md and black veins; these 
^roaalwgejRsa smfUleggrf , Beingatlrkut^in 
178^> I received <fcom» Mr. Bensiog, formeslys 
commandantrof Qfchotaky a^eonndesable . dumbM 
of thtee^ globiiles^ ^^vidh* »b. sample of the ^ sand 
which> wataint ihnb'i / 

^« To judgieibgr ^n^gj^i ifc might i>e said that 
basaltiB. balls Hvismr/iromitiMs hegimidng,. formed^ 
by layers, as they «>#) appear; for the lamiaaif 
te^turet of 4he ^glohiiles <if Okhotsk, seems in no 
wise owMg'to any kind of ^alteration : their thtn 
coats c^Hitiaue, to the centre, of a perfectljr pure 
glass."* 

* Patrin, v. 2g2. Ferrara^ p. 211, 212, may also be consulted 
for the obsidians of Lipari. He observes, p. sgg, that they are of 
infinite variety, and all.lbraied of felspar melted in an intense heat. ' 



» 

* 



IIOIIB VI. OBSIOIAK. 447 

The Piedra de Gaiinazza^ ^bove m^tiolied BaTeiMtone. 
by M. Patrin, is a kind of obsidian; foond ia 
Quito and Peru.j and is so called^ because in 
blackness it resembles the raven. It seems to 
have been sometimes polished^ and - used for 
mirrors ; but must not be confbahded with the 
ttone of the Incas, found in the. fcniile tombs^ 
and used for the same purpose 5 the latter. bbiasg 
a compact pyrites, or marcasite of the Arabians; 
and oiher' early writens on mineralogy. 

In his aocount of the island: of Lipari, afier chmbcsoT 
having 'mentioned several ftiiids *Qf Volcanio 



gfatss, as the pumlceouS) xetiottldt€Ml,'2and'c«piU 
lary, Spalkuizani thns proceadi^ihann^ apoldii^ 
gised for the prolixity of his dci^cription as indto* 
pensdbly necessary for the sake of accuracy, in 
discussions merely scientific. 

*^ 4. The glasses of 4he Mdnte'della CasthgMg spaibumif 
which we have hitkerto' xonddered, are those 
that have a teitare more or less porous ^ we tvM 
now proceed to those of a compact' tftracture, of 
which kind is the fourth 'species; tvUch may be 
said to compose nearly ^one half ofthe mountain. 
This glass, if viewed superficially, and M it i^ 
found oil the ispot, has rather the appeafance of 
a red earth than a glass^ occai^loned by t a red 
earthy coating that invests the gliW'idispojMd 



448 OOMAtN XII. VOLCAKie. 

under It in immense plates; which covering, 
though in many places it bat feebly adheres to 
it^ since it may be removed by simply washing 
with water> in others is so closely united that 
it forms the last rind or outermost part of the 
glass, which induces me to believe that it is *a 
superficial decomposition of it. Beneath this 
earthy coating the glass appears, which is ex* 
tremely perfect, and as if.it had just come out of 
the volcano. If we except a few pieces, in 
which its structure is spungy, it is extremely 
compact and solid, and therefore much heavier 
than either of the other three kinds. It is of an 
olive colour, and transparent whjenin thin scales, 
examined by a bright light ; but in the mass it 
appears opake. It gives sparks rather plenti- 
fully with steel. Pieces of perfect glass, it is 
well kntfwn, when broken, have their fractures 
striated, waving, aAd curved. In this glass some 
of the fractures are the same ; but in general 
they are conchoids, like those of flints. Its con* 
sistence is not perfectly homogenous, as it con- 
tains many felspathose points. Its aspect is not 
lively and brilliant, like that of glass, but some- 
what unctuous and dull ; from all these qualities, 
this product i^pears to be more property an 
enamel than a glass; unless we are willing t^ 



MOMB VI* OBSIDIAN* 449 

consider it as one of those volcanic bodies which 
constitute the middle substance between enameb 
and glasses. 

*' In my description of the glasses of Lipari^ Vemdar. 
I have observed that several of them are inter- 
sected with veins or earthy leaves, by means of 
which they are easily divided into plates. The 
same is observable in the present glass, in which 
we find the same quality as in some marbles^ 
which being cut in the vein may be divided^ 
without any great labour, into large slabs, but 
which break into small pieces if it be attempted 
to divide them in any other manner. Some of 
the workmen who dig the pumices, and were 
very useful companions to me in my excursions 
to Campo Bianco and the Monte della Castagna^ 
at my request drove, with heavy hammers, an 
iron wedge into these earthy veins, and extract* 
ed from the common mass of this glass, large 
plates five feet long, three broad, and two in 
thickness. To the surface of each plate was at* 
tached a coating of hard earthy matter, which 
still more confirmed me in the opinion I have 
already given, that this matter had resisted fu* 
rion, and, being lighter than the fluid glass, had 
ascended to the surface; a conjecture further 
corroborated by the artificial fusion which I 
made of this glass retaining some portion of this 

VOL. II. S o 



450 DOMAiK XII* voidAirie. 

earth, which with difficulty fused, though the 
glasi waft inflated, and changed into a frothjr 
enamel. 

^* This gtas» slightly cuts the factitious glass ; 
and if the cutting angle of one piece is driven 
with force along the surface of another, it pro- 
duces a white and impalpable powder. 
9^uL " ^* ^^^^ Species of glass completely deserves 
that appellation, since, it i$ not only the most 
perfect of all the volcanic glasses of the Colian 
isles, but does not in the least respect yidld to 
what is called the Iceland agate, or tlie pietra di 
galina2S2o of Peru, which is supposed to have 
been the obsidian stone of the ancients. In the 
large pieces its colour is extremely black, and it 
is entirely opake, but the thin leaves are white 
and transparent : the opacity and blackness may 
be said to be in the direct ratio of the thickness. 
This glass, which is extremely compact, is free 
from aeriform bubbles, and from every kind of 
heterogenottsness. It is son:iewbat harder than 
the fourth species, and therefore cuts foctitious 
gkas more easily, and gives more sparks with 
steel. Its edges are sharp and cutting. 

*^ M. Faujas, having obtained Mme specimeni 
of the best glass of lipari, has made some ob^ 
servations oa it proper to be given here. He 
admits that this spedes is the same with that of 



Iceland ; but he remarks, however, that it dilBbrs 
from it in the polish, which appeared to htm 
more unctuous and less vitreous, besides that' in 
the fractures it had not that waving, striated, 
scaly appearance, which is proper to the masses 
oftrueg^ass* 

^ It must be remembered, however, that the 
specimens of M. Faujas were none of the best c 
the pieces, at least, which I collected^ took so 
exquisite a polish and lostrs, th^t I do not be« 
lieve any kind of artificial glass ^yer received 
one more beautiful and brilliant. This gla^s, f^^- 
besides, when in the mass, b^g opake, became 
a tme mirror; and I therefore find'nb difficulty 
in believing that the ancient Pemviatis.used »* 
similar kind of glass, cut and poliid)ed, for mir* 
rors *, This glass likewise could not be broken 
without exhibiting the undulating scales, lightly 
striated, widch the French vulcahist affirms he 
could not find in hi$ specimeips. While I now 
write^ 1 have before me a piece with a recent 
fiactnie, in whidi these ^aves are droular and 
flO Bc eptrical, occupying an area of two inches 
aad B^haU^ the common centre of which is the 
peiW that teoAvai the blow: they resemble ia 

naDtttr tliote waves which a stone pro- ^ 



So8 



452 



OOMAUr XII. VOLCANIC. 



TriiHiMreiicy. 



CokHor. 



daces round it when it falls perpendicularly into 
a standing water. 

'^ I cannot omit another remark. M. Taujas 
says, that the ddges of this glass where they are 
very thin, if presented to a strong light, are 
a little transparent. The transparency of the 
thinnest parts of the glass on which I made my 
observations, when compared to that of common 
factitious glass, is certainly not equal to it : it is 
not, however, $o much inferior as this naturalist 
seexik^ to suppose. A scale three lines and a 
half in thickness being presented to the flame of 
a x^andle, afforded, in part, a passage to the light; 
an4 another,' two. lines thick^ being interposed 
betyireen'the eye and external objects, permitted 
a confused sight of them. Another, half a line 
in thickness, being laid on a book, it might be 
read with the greatest distinctness. 1 have en- 
tered into these minute details the better to show 
the perfect quality of this glass. 

'' The opacity of this glass in the mass pro- 
ceeds from a veiy subtile, and perhaps bitumi- 
nous substance, incorporated with the vitreous 
matter, and rendering it dark like a cloudj The 
glass loses this substance if it be left for some 
hours re-melted in the crucible^ and it then J)e* 
comes white." . 

^* Bergman observed that the Islandic glass. 



NOMB VI. 



OBSIDIAN. 



453 



when exposed t^^the fire, melts with difficulty; 
without the addition of some other substance as 
a flux. In.this it differs from the present of Li- 
pari^ which soon begins to soften in the fur- 
nace, and in a few hours undergoes a complete 
fusion. , 

** This kind of glass, however, is not the most 
common to be met witb on the Monte della 
Castagna. It is found only in a few places, 
scattered, in large hut solitary masses ; nor can 
I pretend to say whether these are remains of 
currents, or whether they were thrown out by « 
the burning gulfs. 

** It happens to this glass as to the different Mixed. 
kinds of precious stones, that is, the same 
piece is not always- throughout of equal purity 
and value ; for on breaking some of these masses 
we sometimes find one portion veiy pure glass, 
such as has been already described, and the 
other imperfect \ either because the fusion has 
not been general, the substance containing bo- 
dies foreign to the base, or because that base is 
rather an enamel than vitreous. These bodies 
are felspars, but of a new appearance. Nothing Pekpan. 
is more common thaa to find felspars in lavas, 
and lometimes even in enamels and glasses ; of 
which we have frequent examples in this work, 
as well as in the accounts of other writers : but 



4A4 DOMAIV XII. TOLCAariC. 

these felspars are always inserted ioimediateljr 
into these substances without any intervening 
body* Here, however^ the case is different ^ 
every felspar is surrounded with a rind or coai> 
ing) which^ when it is extracted entire fix)m the 
enamel, appears to be a vitreous globule, about 
one or two lines in diameter* of a clear cinereous 
colour. If we break this globule^ we find within 
it the half-fused felspar, not divested of its coat- 
ing, but forming one t>ody with it Theae glo- 
bules are very numerous, and sometiikite by their 
* confluence form groups ; and they are very dis- 
tinctly visible, on account of the black c^dir of 
the enameL 
Coating. *^ The manner in which this coating was 
formed around the felspars, I conceive to be as 
follows: when the enamel was floid^ and eii^ 
clo)9ed the felspars, it acted as a flux to their 
external parts, and j^ombined with them ; and 
fmm this combiaattoo was tiie riod <m coatitig 
produced, while the ittfeemal part of the fels^ais 
had only andevgone a semiftisioti> becanieit was 
not in ifliaiediate contact irith the emiad. 
There can be litde doubt bat that the Mspacs 
likewise existed in the fyerfeot glass $ but the 
heat probably being more activie ia that than in 
the eaamd, they were enmpietdy dsssolved^ and 
the entile .nmsa nedaced to otie aimilar tumskstt-^ 



NOV* VI. OA0IPIAV, 4^5 

eoce. As a proof of this conjecture the furnace 
produced a complete homogeneity of parts in the 
enamel containing these extraneous globules. 

'^ 6. When treating of the rocks of the castle 
of liparit I said they were formed of a cinerepus 
lava of a felspar base» which in many places has 
passed into glass. I likewise remarked that the 
]ava» as well as the lai:ge pieces of glass, was 
filled with globules apparently not dissimilar to 
I3ie base. At the beginning of the Monte della 
Castagna, not far from a cottage, the habitation 
of one of the labourers who dig pumice, there is 
a current of similar glass that falls into the sea in ^°^'.^^ 
several branches, and which I shall here con^- 
sider as the sixth species. This glass, however, 
ba3 a more fine and shining grain, and its frac^ 
ture is exactly such as we obser?e in glass, yet 
in beauty it is little inferior to the fifth kindi 
and if whiteness, or mote properly the want 
of colour, is particularly valuable in volcanio 
flMses (siace those whicb bave this quality are 
extremely rare), this certainly has considerable 
daim to ofir attentuont not that it is entirely 
ooiourJeRs, as it contains a kind of obscure cloud, 
which gives it, when viewed in the mass, a 
blackish hue, but at the edges it appears white. 
The round cinereous bodies with which it is 
fiiied form the most pleasing and conspicuous 






'456 V OOlfAIM XIL TOLCANIC. 

contrast, and render the glass irregularly spot- 
ted. I have large pieces of, the fifth sort cut and 
^ polished: their colour, which is that of pitch, 
gives them a peculiar beauty. The blackest 
and choicest marbles of Varena and Verona are 
far' inferior to them in fineness of grain and 
lustre 5 yet, from their uniformity of colour, they 
are less t>eautiful thait this spotted glass, when it 
has received a delicate polish from the hands of 
the artist. On the shore, where the torrent fell 
into the sea, we find pieces of all sizes, rounded 
and smoothed by the continual agitation of the 
sea: I have met with more than one of half a 
foot and a foot in diameter. Notwithstanding 
the powerful action of the waves, which have 
beaten on them for so long a time, their internal 
parts are not injured ; and, when cut and po^ 
lished, they present sur£su)es very beautiful to 
the eye. Tablets of this kind of glass (and 
there is no want of pieces of a proper size to 
form them) would add much to the grandeur 
and splendour of any sumptuous gallery. 
Origin. c« But disregarding the beauty which delights 
the eye, let us proceed to oh^edt& that attract 
and interest the curiosity of the philosophical 
inquirer. We shall find that the cinereous bo- 
dies included in this glass are only points of lava 
with a felspar base ; and on examining .in va* 



NOME Vt. OBBIDIAH. 45? 

rions places the current of this glass> we shall ^ 
perceive that it is a continuation of the same 
lava with the felspar hase, of which these orbi- 
cular corpuscles are composed; whence we shall 
not hesitate to conclude^ that from this stone 
both the lava and the glass derive their origin^ 
and that we find small particles of lava scatteced 
through the latter, because it has not undergone 
complete fusion ; whence we find some pieces 
composed partly of glass and partly of this same 
lava. In some of these pieces we discover small 
geodes, or thin filaments of an extremely brilliant 
and transparent glass, resembling in miniature 
the husk of the chesnut. 

<* 7. Though this glass in many particulars 
resembles the last species, it yet differs from it 
in others. It is perfect, like that, but it is of a 
deeper colour. In it, likewise, the small glo- 
bules abound, but they are earthy and pulveris- 
able ; every one is detached in Hs distinct niche^ 
or at most is only fastened to it by a few points. 
^^ The description of this seventh species of 
glass will render that of several others unneces- 
sary, since the glasses I should have to describe 
contain a greater or less number of similar glo- 
bules, differing only in the nature of the base 
enclosing them, which in some is more, and in 
others less vitreous. I shall only make one ob- 



458 



OOMAIH XSI. rOhCAHlC. 



servatioD, which I think to be of some imports 
aace, relative to the glaates I here omit. Several 
of them have, even in their internal parts, fis- 
sures frequently an inch in breadth, and three 
inches in length. These are not entirely vacni* 
Fiiamento. ties, but are frequently crossed by small threads 
of glass, connected at their two extremities with 
the sides. The broadest of these threads are 
four lines in breadth, and the narrowest scarcely 
a line. When broken they have the fragility of 
gla^, and are found to be a most perfect glass, 
being colourless, and extremely transparent. It 
is easy to conceive that these threads have been 
formed in the same manner with those of the 
capillary glass, fouiid in similar fissures in the 
third species of glass. 

^' 8. The eighth and last kind of the vttrifi* 
cations of the Monte deUa Castagna may be 
denominated ani^nameU that has the colour and 
lustre of asphaltum» of a scaly grain, a very 
small degree of <irand|parency iti the points of 
the fr9Ctiixe§, and of consideiable weight and 
compactness, though it ia extremdy friable. It 
is found in solitary masses, not very numerous, 
and the broken^ pieces have' the property of 
assuming a ^obose form* Some of these globes 
resemble those found by M. Dolomiea in the 
idand of Ponza. I hav6 been fovoured with 4wo 



Unctaoos. 



MOMB VI. OBSIDUir. 450 

of the latter by the Abbe Fortis ; but I find that, 
excepting their globose figure, they differ io 
every respeot from those of which I now speak. 
The globes of Ponza are composed of leaves 
over leaves of an imperfect enamel, do not give 
sparks with steel, and contain febpars and mi* 
ca ; whereas those of the Monte della Castagna 
rarely include a few felspars, give sparks with 
steel, have a vitreous appearance, and, are not 
composed of plates or leaves. 

** Some pieces of this enamel, brc^en and de- 
tached from the masses, are in one part true 
enamel, and in another lava. The latter gives a 
few sparks with steel, has & grain approaching 
to earthy, and, as far as I coold dboover, has for 
its base a soft hom^stone, from which conse- 
qoently the enamel likewise derives its origin. 

^^ These are the principal. vitrifications I ob* 
served in my excursions to the Monte della Cas- 
tagna. Somo I have omitted to notice, sioce^ 
some trifling differences excepted, they are es- 
sentially the same with those described. It is 
proper, however, to remark, tliat more than one 
of (hem exhibits -manifest signs of having once 
flowed down tlie i^des t^ <lie movntein, in the camnts. 
thick threads and vitreom filaments they con« 
tain, irimitaf to thpse we see, <m a lesser scale, 
in glass fraed in xmv ^flmaces, when it •comes 



460 



DOMAIN XIU VOLGANIC. 



Melt in the 
fiunace* 



into contact with the cold air> as it flows down 
an inclined plane. 

" Every one of these eight kinds of glasses 
and enamels may be completely remelted in the 
furnace. When speaking of the compact glass 
of the rock of the castle of Lipari, I remarked 
its extraordinary inflation in the furnace, and 
said that this tumefaction usually accompanies 
a refusion, in our fires^ of solid glasses and voU 
canic enamels. I then had in view those of the 
Monte ddla Castagna, five of which, though 
compact and solid, in the furnace swelled high 
above the edges ; notwithstanding that, before 
their refusion, %heyt)nly filled athirdpartof it/' 
> These ample descriptions may serve to show 
the precise nature of volcanic glasses, which 
some have confounded with the aqueous pro- 
ductions. 

The obsidians, or volcanic glasses, and amels» 
may be arranged in the following order. 



Divenities. 



HTPONOMB I. VITREOUS. 



This can scarcely be distinguished from glass. 
The generat colour is black, whence it forms ex- 
cellent mirrors for lietndscapes : it sometimes pre- 
sents white spots, which are. ^decayed crystals * of 
felspar, whence the base is supposed to be a vitri- 



* 4 



' i 



ROMl VI. OBSIOIAV. 



461 



fied trap or basaltin. The white fibrous veins 
sometimes observable seem also tO' be of felspar^ 
which when Ideated assqtnes a fibrous form. 

But obsidian also occurs of other colours, such 
as bluish, dark green, yellowish, and grey ; nay, 
Troil says that in Iceland it is s6metimes found 
colourless, like crystal. Dolomieu mentions a 
yellow vitreous lava, with black mica and white 
quartz, somewhat resembling pitch-stone, and 
which seems a granite in a particular period of 
fusion. In the eruption of Etna, 1787, a vitreous 
lava appeared, interspersed with particles of talc*. 

The volcanoes of New Spain sometimes present 
a beautifii^ obsidian, in which a spangled light 
plays upon a brown base, with an effect resem- 
bling aventurine. 

Micronome 1. Entire. Common black ob- 
sidian, firom Iceland, commonly called Icelandic 
agate. 

The same, firom Peru, piedra de Galinazzo. 

* 

Bluish obsidian, from Iceland, Teneriffe, &;c. 
^ Yellowish, from Lipari; ^ 
Crystalline, from Iceland. 
Refiilgent, from New Spa^n. 

* Dolomieu Ponces, 93, Etna, 509. 



46SI OOMAtV XII. VOLCAWtC. 



HYPONOMS II. FORPHYftlTIC. 

This kind, spotted with decayed crystals of fel- 
spar, may be found in most of the preceding sites. 

Faujas gives the following examples. 

" Obsidian, with crystals of white felspar, which 
have preserved their form and colour, and which 
are rather^^V^ than melted. 

^ Obsidian of a very sharp fracture, with & 
number of little round and oblong globules of a 
dull white substance, which i^sembles amel, and 
which may proceed from a granular felspar, spread 
in great abundance in the paste of the stony sub- 
stance which has given birth to that beautiful 
black glass, spotted with white. The paste of this 
obsidian should be frisible; for. the glass which 
results from it is pure, and although it appears 
of a deep black in contrast with the white spots, 
it is of a fine transparency on the edges, and rather 
white than black, but of a smoky white : found at 
Lipari. Some specimens of Ihis yolcaoic glass 
are seen in which the same white substance, in- 
stead of being disseminated in the mass, is dis- 
posed in small layers, very thin, of the thickness 
of half a line or a line at most, which alternate 
with layers of glass, very black and shining, of 
four, five, or six lines in thickness. This beauti- 



NOMB Vi. OBfllDlAir. 46$ 

ful glass wad discovered at Lipari by Spellan-* 

^^ Black volcanic glass^ rather porous, enamelled 
with reticular lines of white felspar, which every 
where penetrate it, and cross each other in differ- 
ent directions : the black part is melted, the fel- 
spar is only a frit 

*^ On the summit of Mont Meisner, in Hessia, 
are found isolated bj^ocks, of a large bulk, of this 
stony substance, whose base is incontestably vitri- 
fiied ; while the felspar has undergone but a slight 
alteration. There is nothing extraordinary in this 
fact, since the obsidians of Lipari not only afford 
us a similar example, but also show us the felspar 
in its state of crystallisation. 

" It is nevertheless proper to observe, that the 
crystallised felspar, in the obsidian of Lipari and 
other places, is an indication that this obsidian 
owes its origin to a porphyritic rock, whose base 
should be a trap, or a paste of felspar in mass ; 
while the reticular felspar of the volcanic glass of 
Mont Meisner seems to differ in its origin, ^d to 
have had a base different from porphyries. 

<' The disposition of this felspar, interwove in 
a vitreous black substance, recalled to my recol- 
lection some stones which are not volcanic, of a 
similar texture, which I possess in my collection 
of rocks. I carefully examined them, and I per- 



464 ooMAiir xii. voLeANie. 

ceived their analogy.' These last are composed 
of a white filaceous felspar, which intersects small 
' black and shining crystals of tourmaline/* 

HTPONOBIB III. WITH WHITB FIBROUS VBINS. 

This kind is also found in the Italian volcanoes, 
^ but the most beautiful is from New Spain. 

BYPONOMB IV* CAPILLARY. 

It appears, from Dolomieu*s account of Etna, 
that this kmd sometimes appears in the large ve- 
sicles of vitreous lava: but that of the Isle of 
Bourbon, above described, is singularly curious. 

HYPONOMB V. GRANULAR. 

Patrin, as above quoted, has described a hill of 
vitreous sand. 

There yet remain two important distinctions of 
vitreous lava* 

HYPONOME VI. RBSINOUS. 

These have somewhat the appearance of pitch' 
stone, and Icelandic obsidian sometimes assumes 
this visage*. They are by many, not improperly, 
classed in the next division. 

* The untninlatable hiibx/ades is more ei^esuve. 



'- MOMB TI. OSMDI4V. 46ff 

The peiiiarkcJ)le isle of Pentdkria, between 
Sicily and Africa (the ancient Cossura, of wfaich 
there are coins), produces a black oiisidian of so 
unctuous an aspect that Ferrara compares it to the 
bitumen of Chaldea. It is perfectly opake, even 
in the thin edges ; and has numerous crystals and 
quadrilateral plates of felspar in perfect preserva^ 
tiaOj except that it has a dry aspect, and is stunned 
insome parts. The pieces more frae from felspar 
arc ei^lremely hard, with a conchoidal and oftea a 
flttiated fracture like common glass. When rub* 
bed they yield a powerful smell of burnt hiir*, 

HTPOMOliB VU. VOLCAKIC AMBLS. 

Faujas, in his classification of volcanic pn)-D«cni>tioni>y 
ducts, has so amply treated tiiis curious subject, 
that his account deserves to be translated, for the 
benefit of the English readcrf. 

" When compact lavas, either prismatic or 
amorphous, are fused in a crucible in the furnace 

• Feir. SM ; mJotv di4:itpeUi hmH^. ^9M 4liii c^pmi A^ 
m<fefinftHe tmell of quartz } 

f Annales du Museum: but much altered and gceatly enlarged in 
te tecond Tolume of his Eum de Gtologie, Pteu^ 1809> Sro. Aft 
first there were seven, but now twelve, dassei. i^}udiciDii0l)r eliOHa 
and arranged from tii^ng objects and circumstanoes | while aome 
important substances are omitted. But there are many nordties, 
and ingenious observations, as usual, in the works of Faujas. 

^Ikt formoral^^ is piclvfrtdi for the reasoii aliwdy assigooi. 

VOL. II. 2 H 



466 DOMAIN XIX. YOX.CAMlS' 

of a glass-house, \^ithout the addition of any flux 
or dissolvent, a fine and shining glass, of the most 
beautiful black, is obtained in a few hours. When 
it is in a mass, this glass is very opake ; but in 
breaking and reducing it into thin plates, it is 
found to be transparent, biit a little coloured by a 
fuliginous substance. « 

m 

^^ If the substance submitted to this experiment 
is derived from a trap, the glass is then of a 
greenish colour, and is much iriore transp^Mit on 
the edges. It may even be refined by the assbt- 
% ance of soda, so as to form a fine bottle glass ; 
which does not happen when basaltio^va is used 
instead of trap ; for, in the latter mstance, the 
substance cannot be blown but with difficulty, and 
without success : and the glass is neither good nor 
transparent. I know the contrary has been as- 
serted in a work on chemistry ; but experiments 
that I made in the presence of well-informed men^ 
in 1784, in the glass-house of Sevres, near Meu- 
don, and of which I have preserved the minutes, 
demonstrate that b^||ttltic lava used alone, can in 
no instance make bottles : that it is neither im- 
proved by soda nor potash, but other substan^^ 
must be added to it. 

" The theory of volcanic glasses, obsidians, and 
amels, needs not be sought elsewhere. If I distin- 
guish amels from other vitreous pro^dctions^ pro- 






I 



MOMS VZ. OBSIDIAir* ' 46? 

duted by subterraneitn fires, this difierence only 
relates to a gilsater opacity, and a more unctuous 
and rdnnous aspect %hlch amels possess ; while 
the glasses, of whatever colour, have a brighter 
lustre, are more crystalline, aiid seem better 
melted. 

^^ Real pitchs tones, whatever may be their co- 
lour and their vitreous , appearance, must not be 
confounded with glasses and amelat they are 
foreign to them. 

" 1. Grey amel, with shades of a grey white, Amd^ 
rather greenish, with a fracture rather stony than 
vitreous. Its contexture, and the vesicles seen in 
its paste, leave no doubt of its being a volcanic 
amel. In observing it with a lens, crystals of fel« 
spar, which characterise it9 porphyritic origin, are 
even perceived, -^his variety comes from Ascen- 
sion Island, where it was collected by M. de 
Berth, an able mineralogi^ who has some fine i^. 

collectionsr of lavas firom the isles of Bourbon and 
France. 

" 2. A yellowish grey amel, rather reddish, 
with a resinous fracture. If I may be allowed to 
use the expression, it is what Dolomieu has called 
resiniform lava. ' Its grain, its fracture, its semi- 
vitreous paste, all indicate its being an amel ; and 
the crystals of felspar, distinguished on polishtd ^■ 
faces, announce that this amel owes its origin to 

S H 2 



4M DOKAm %n. w^vsxmc. 

m fmphyiy wkh m base of Msptr. It is found at 
iipftri. 

^^ 3. Reddish grey amd, ^opiJce, with « Btody 
fractaire, having some relation to what the Ger- 
taM minepalogi)^ oafl porzellan j4Upu ; but 4t is 
incontestably an amel, since the greater part of thi) 
ipecioaetis found at lipati «re perforated with 
pores^ amd in some parts ^ritrified; whereas ja»^ 
pers OK infiisihle. 

'^ 4. A bluish grey aoiel, with a sUning fiiac* 
ture and an homogenous paste. 

^^ 5. A greenish amel, opake, shining^ fractuns 
vitreous with crystals of white felspar. Whten lliese 
amels are cut and polished, the crystals are better 
observed. In this class I place the vitreous amel 
of Puy Gryou, in Auvergne^ formed in a laarge 
.^1 current covered with lavas. M. de la Co^ 

professor of the cerftral school of Puy de Done; 
first pointed out this amel. 

** 6. An olive-green amel, of an mnogenouft 
paste, and with a fracture of pitohstone, of Modta 
Galda in the Vicentin. 

** 7. An ttnel, of a h<miogenous paste, with 
pitehstone fractare, of a pale black, with very fiM 
and undulating zones of a smoky grqr, from Asoen* 
sion Island. 

' ^^ 8. Vitreous amel, g( a coal black or obsidian, 
fracture irregularly ccmchoidal. I give tlK aama 



M 



NOIM WfU TOLCAMIC mnSTB. 4^9 

of obsidian to Uack volcanic j^aases*, whatever 
may be their opacity and their brilliancy^ more er 
less unctuous, Ofc their paste more or ksa vikreoos^ 
provided tiiat their transparency is visible on "dieir 
edges in the thinnest fractures of these glasses. 
The preceding number forms the tranrition of 
black amel to the obi^idion of the Ascension Island^ 
of Tenerifie, of Stromboli, Vulcano, &e." 



NOMEVn. VOLCANIC INTRITE. 

This' denomination, as in the other di visions. 
' ' S-* includes those substances which^ on a baae, pre- 



-4#f 



sent crystals of various natures; and which hav^ 

thence often been vaguely styled porphyries* 

Real porphyritic lava has already been consi- 

dered» under the Nome Compact I^va ; being 

one of the most common appearances of that 

kind» and scarcely distinguishable from genuine 

porphy ry, with a base of basaltin and crystals of 

felspar. 

• The most remarkable and singular volcanic 

intrite is that with leucite» a crystal resembling with leactte. 

a white garnety and at first so named> which 

seems peculiar to the lavas of Vesuvius,- and of 

• Obsidian may h% ofsererai colouni as already mentioned. 



470 DOMAIW XII. TOLCANIC. 

extinct volcanoes in the Campania of Rome. 
Breislak, an eminent mineralogist, has minutely 
discussed the leucite> in his interesting travels in 
thof^ parts of Italy : and as the nature of his 
work rather precludes any hope of its being 
BrenWs de- translated^ his accounts of the summit of Vesu- 

acnption or » 

VeBovius. yius^ |^nd of the noted eruption of 1794, which 
are more scientific than any other descriptions^ 
shall be here given ; after premising that Vesu- 
vius forms, as it were, a part of a larger moun- 
tain, called Somma, which, in a semicircular 
form, includes on the north the summit of this 
celebrated volcano. 
Cone "^ «« The present cone of Vesuvius is truncated, "" ^ 
'%o as to form an inclined plane, sloping from the 
north east to the south-west. The circumfer- 
ence of the summit, which forms the brim of the 
cauldron, is about 3000 feet ; and at the bottom 
is distinguished an oblong plain, the greatest 
diameter of which is from east to west. Having 
since ascended several times to the top of the 
cone, I perceived that its depth had gradually 
diminished, and that the bottom of the crater 
became higher daily, owing to the different mat- 
ter which falls down, especially from the almost 
perpendicular sides on the east and north. One 
may at this time easily scan the extent and depth 



<f: 



WOKS VII. VOLCANIC INTftlTI. 



471 

of its mouth ; but^^occasionally it is much en* 
cumbered, and sometimes totdly clogged. In 
17^^» the bottom of the funnel rose so consider- 
ably that it presented a vast plain^ only 23 feet 
beneath the brim ; and in the midst of this plain 
was another cone, from 80 to 90 feet high, with 
a small crater from which the eruptions pro- 
ceeded. 

^' Braccini has left us a curious description of state of crater, 
the state of the crater of Vesuvius, after a long 
state of rest, and before the grand eruption of 
1.631. The whole of it, or at least its greater 
part, had become accessible. Having himself de* 
scended into the crater, he says he found it co- 
vered with plants and trees, and that a road 
down it was practicable for the space of a mile ; 
that at this depth a very deep cavern was seen, 
which having passed, the way was again open 
for two miles^ by a very steep, but at the same 
time very safe road, owing to the trees growing 
near to each other. At length a large plain 
presented itself, surrounded by a number of 
grottoes and caverns, which might be entered, 
but which the party were deterred from, on ac- 
count of their darkness. This plain, which was 
not accessible otherwise than by a very rapid 
slope nearly three miles in length, must, assur- 



471 wcmAim viu ToLMvse. 

ecUy^ have been much bem^h the lerA oi the 
tea*. Had the grottoes then been visited, wfaa* 
a fbnd of knowledge might no* have been ac** 
i^uired ! 
Vapoiin. «^ When the rolcano is at rest, rapours ard 
seen to arise from the canldron's brim, or from 
the interior of its sides, which are very percepti- 
ble. It would be difficult to conceive it possible 
that they should proceed from the internal ftir- 
nace ; that they should, by tortuous and hidden 
conduits, penetrate from such a profound depth 
to the summit of the cone : for all confined va« 
pour seeks for liberation by the shcnrtest road ; 
and, consequedtly, were these derived from a 
tource so low, they would issue from the bottom 
of the cauldron, which presents them an easier 
passage with a smaller mass of matter to t»^ 

* *' If the angle of descent, during the distance of the three miles* 
was 60^ from vertical, or 30® from an horizontal-line, the perpendi- 
cular depth, by a plain trigonometrical problem, will be found t6 
have been 7g90 feet -, if, however, the steepness of the dedivi^ b« 
reduced to form an angle of no more than 22p, the perpendicular 
depth will yet have been 6060 feet ; and, as the height of Vesuvius, 
according to our anthor (tome ii. p. 43), is only sgSS Engliah feet, 
allowing the statement of the length of the descent to the plain^ as 
stated by Biaccini, to have been correct, viz. three English miles, 
or 52S0 yards, that plain must have been at least SOOOfeet'belpw th» 
level of the sea, eten with a slope of descent of only S!8('} but if A 
slope of 30^ be allowed, it will hare beta 4000 English liKt bdoW 
4he level of the sea I Traitsl.'* 



^ 






JKOMB Vll* TOLCAHIC inAITJk 



473 



m 



terse. It is therefore probable that the^ fome$ 
ara the production c£ substaaces* in the neigh« 
bonrhood of the brim of the crater> in a state of 
decomposition. 

^< When the mouth oi VeMTius is observed 
from any distance, and during the prevalence of 
moisture in the atmosphere»' a niMjk of vapour 
seems to rise from it which mingl& with the 
clouds. Entirely distinct from any volcanio 
cause» these are only the humid vapours in the air» 
attracted by the conical diape of the mountain^ 
and imprisoned in the vast cavity of the caul<» 
dron. Vapours which spring firom^ or are dtf» 
fused over a plain^ are dismpated by the air and 
winds ; but when enclosed^ they are much less 
readily dispersed. 

*^ The western portion of Somma must be con« sonmn. 
sidered as connected with the cone of Vesuvius^ 
by a hill of smaller eminence^ denomijbat^ 
Monte Cantaram, on which iathe hermitage del 
Salvatore. This hill is intersected by three val- Vanep. 
leys that c^serve to be examined with attention, 
6n account of the quantity of primitive sub- . 
stances which the volcano has thrown thither, 
durin)^ old eruptions. The northern valley is 
that termed La Fossa di Pharaone near the plain, 
and Vallone delta Vetrana in its more elevated 
part, where the current of lava flowed in 178^« 



^1 



I. 

4*^4 DOMAIN Xir. TOLCAMIC. 

This vale, hollowed by rains, is the only interval 
between Mount Somma and Mount Cantanmi. 
South of this vale are two others nearly parallel, 
.*^*» the first called Rio Cupo; the second Fossa 
Grande, which taking a direction from east to 
west, merges in the plain of Saint Jorio. Its 
northern siijie^ nearly perpendicular, rises to a 
considerable height above the valley, and beings 
composed only of lapillo*, pumice, and other 
substances of an inadhesive quality, is subject 
frequently to crumble and fall in large quantities. 
Along the whole extent of the southern side, at 
its upper part, is seen an ancient current of lava, 
which at first sight appears to be several strata 
of lava imposed one on the other, but which a 
little attention shows is but one current, in 
which horizontal chasms have been occasioned 
by refrigeration, and into which the wind has 
sific^llintroduced a slight quantity of vegetable 
earth. This lava js hard and compact ; it con- 

* * This is the denominatiou.^ven to fragments T>f pmnioe, the 
largest of which are from six to eight millimeters (a quarter to a third 
Jyofan inch) in thickness. It is of this lapillo, saturated with lime- 
wttter and well beaten^ that the floors and terraces of the'houses are 
-made at Naples. It is spread in a uniform nxanner about Hk or six 
inches deep, and bj beating is reduced to the thickness of two to 
two and a half inches. It then becomes a body of sufficient solidity 
to be impervious to water, and so hard as to bear being hewn like 
tufo," 






%• 



% 



KOMB VII. VOLCANIC INTRITS. 475 

tains but few fragments of aogite or pyroxene^ 

and seems to be an assemblage of leucites, the u£dta[ 

superficial crystalline lostre of which, ^vingi^ 

been impaired by decomposition, makeA^ re* 

semble variolite in its exterior. Many detached 

masses of this current have fallen to the bottom 

of the valley. Each fall of matter brings down 

oalcareous stones, mica, mixtures of felspar, mid 

idtfcrases. The lava of 1767» which threat^e^ 

the villages of La Barra and Saint Jorio, dis* 

charged itself into this valley, which it filled to 

a certain height, and afterwards flowed, spread* I 

ing itself, to the plain. As it is already covered 

by the crumblings from the flank, in order to 

examine it the inquirer must repair to the plain 

of Saint Jorio, in the neighbourhood of the cha* 

pel of Saint Vito. Its gr^n is crystallis^||jAt 

fine, and oftentimes so close and compactaFto 

be nearly equal to petro-silex. It contains many 

sm^kU crystals of pyroxene, and fragments of 

leucite, which is rarely found in its perfect form 

of crystallisation .... 

" The lava of La Scala passes beneath the gar- ^XJjf 
den of La Favorita. It is of the colour of ashes, 
whitish, and of a crystallised grain. It contains" 
many crystals of pyroxene, few of leucite, and J^ 

small pieces of felspar, in %roups in its cavities. 
This lava^ where it is hewrf on the sea-shore near 



476 DOMAfH XIU VOLCftNiC. 

La Cavalleria, is worthy of attention. Under a 
tinifonn bed, from 15 to 20 feet in thickness, the 
instnta. "^lava IS found divided into strata of frcwtbree to 
;». four feet: these dirisions are formed by parallel 

X and'horizontal lines, and where these are dog 

down to, the lava is found to have separated itaelf 
(Spontaneously into beds. Below them are large 
Prisms* pTJfpQSj commonly hexagonal^ which are disjoined 
with great ea^: in some places these prisms, 
instead of the lower are found in the upper part 
of the current. Some of these large prisms I 
hare seen, the summit of which was parted into 
a number ^ small prisms. These observations 
sufficiently demonstrate that the recession of the 
matter of the lava, when in the act of cooling, 
is the sole cause of the form, whether even or 
p|i^4itic, which it assumes ; and that this cause 
is capable of giving to lava t^e appearance of 
stratification. This phenomenon may afibrd 
ground for reflection to those geologists who so 
strongly insist on the fact of horizontal and ver* 
tical beds of granite, as affording a proof of 
deposits being first made in a fluid, and after- 
wards diverted from their pristine position, I 
am far from inclining as yet to adopt any ge- 
ological system whatever; for, in my opinion, 

we have not hitherto edttected a sufficient num« 

*• .-"* 

ber of fietcts to prodiifee one that will bear the 



NOm Tit. VOLCAVie Un«tTE. 



477 



test of reason. I merely give iny observations^ 

vrit^ the reflections theif suggest ideologists 

are not y^et of one opimon reapecting the strati* v^ 

ficatioQ of gmnite, although it appears to be 

deaiiy demonstrated by theobsen^iom of Sans* 

sore. Adttutting, however, the truth of the pro« 

Mem, solid reasons may ^lence be d«luced for 

believing that the ciroumsta»ce is mone indebted 

fer its existence to st state of aqueous than to 

one of igneous fluidity : here, however, is a cuiw 

jent of hand and i^euipact iava, which most 

assuredly has undergone a state of igneoH 

fluidity, and to ii^ieh refrigeration has given tin 

hori2NMital stratification. It may be objected^ 

that granite forms chains of immense mountains^ 

and thait this is but a small current, scarcely a 

few yards thick; but the p3ienomenon is the 

same: the tifierence between great and litde, 

however matemai with us^ being nothing with 

nature. 

^ The same tendency to a fasuisBtic confonnaF- 
tion, which is noticed in the lava of La Scala, is 
observed again in tdie neighfooaring correirt of 
CalastK). This, afier passing throngh a defile of CaUsuo. 
bdow Valldonga, spveads to a broad £ronft on 
leaching the sea. What most deserves observa- 
tion in the lava here, mm die small crystallisations 



9,Jtttt 

seoVto 



presents, ^vhioh seVto be the olivine of Wer 



r.-..^ 



478 ooMAiir xxr* tolcaiiic* 

ner. It is, moreover, of a deeper colour than 
the laf a of Scala, more porous, and like that 
contains many crystals of augite, and fragments 
of felspar. On an excursion to ^ gulf of Sa* 
lemo, the sand of its shore, and more especially 
that q£ the coast of Amalfi, presented similar 
cryslipj tfk abundance, as well as augites, both 
substances indigenous of this country, whither 
it is unlikely they should have been transported 
from Vesuvius. A rock of a similar kind also 
may possibly have ^supplied that volcano with 
them on one of its eruptions. 

Lava of 1794. << Next to this lava is foi|n4|ihat of the erup- 
tion of 1794. Of the different eruptions of Ve- 
suvius this is the most recent, and was one of 
the most considerable. Having had occasion 
to observe it myself, and trace it with attention, 
it possibly will not be displeasing tlPmy readers 
that I should present them with a description of 
it in this place. ^iV SL 

^e mpti^. " Vesuvius had continued tranquil for a long 
time. On the 12th June, 1794, towards eleven 
in the evening, a very violent shock of an earth- 
quake was felt, which induced many of the in- 
habitants of Naples to leave their houses for the 
night. The tranquillity of the mountain did 
not however appear to be disturbed either on 
the Idth, 14th, or 15th, nor did it exhibit any 



♦ai 



NOMS VXr. TOLCAKIC IvfRITE. 479 

syinptoin of an approaching eruption ; bat, Vm 

wards nine in the evening of the last day, many 

symptoms were manifested. The houses about 

the mountain experienced violent shocks, which siiocks, 

gradually increased in force; a very powerful 

one was felt at ten o'clock in Naples and its en* 

Yirons. ^ At this instant, on the western base of 

the cone, at the spot called La Pedamentina, and 

from the midst of ancient torrents, a new mouth 

disgorged a stream of lava. This opening was ismeof hvm. ^ 

237^ feet in length, and 237 in breadth. Scarcely 

had the stream of lava begun to flow, before .f 

four conical hills, each having its small crater 

(the third alone excepted, which had two distinct 

mouths), arose out of the stream itself. From 

these different months stones were parted into 

the air with great noise, and in a^tate so highly 

ignited that they resembled real flames ; the ^ 

plosions indeed were so qui.ckly repeated that 

they seemed but one, and formed a continued 

sheet of fire in the air, which received no other 

interruption than what was occasioned by the 

inferiority of t^ j^rce of some of the ejections. 

They sometimes vomited substances, I may say, 

in a fluid state, for they expanded in the air like 

a soft paste, so that one may imagine they were 

either a part of tbfc running lava, or masses of 

old lava fus^d and pifUSpted. Some of these 



'% f- 




1^ 



480 JDtKAtV maUt TOLCANIC* 

Wms were contigv^w one to the other, and it 
seems as if the fi>roe by which Ahey were pro- 
duced had aoet with obstruction to the disgorge 
ment of the substances at one point, and conse* 
quend J effected several issues in the same line. 
The iara flowed in one bodj finr some time, aad 
at mtenrals flashes <of light arose fi!cm the sarfiM^ 
of it, produced by jeks of hjrdiogeaous gas, whidi 
disengaged itself from the Java precisely in tiie 
same manner te the gwes ezpaaided from the 
Diraetion. sur&ce of a fluid. Its first Erection was towards 
Portici and Besina, so that the inhabitants of 
Torre del Greco already bewailed the £ste of 
Iheir neighbours, and began their thanksgivif^ 
to the Almighty for their escape. Collected to«- 
gekher in t^ church, they were still singing 
mns of joy, and espressing their gratitude^ 
en a voice anaH>unced to them the fatal news 
cf their altered destiny. The stream of ia?a, <hi 
flowing down a declivity it met in its way, di^ 
Tided its^ into thpee branches; one bearing ta>» 
wards Sta Maria de P«gliano traveiaed a space 
of 906$ feet ; afuodier, directing dts course to- 
wards Resina, flowed to the distance of SiBl 
feet ; while the remainder of the stream, iaUiag 
into the rsdley of Mi^mo, flowed towards La 
Torre. On reaching the okapel of Baizano it 
Ibraied a branch towuEl|( the 4K)atli*ea9t, which 



hyc 






now Tin . rOLCAMlQ IMTUTB. 4g] 

teiminated in file territory of Aniello Tirone^ 
after having ran the length of 1490 feet; the 
leiidve of the laya> punuing its course^iflowed 
iqpon Torre, presenting a front from twehe to 
fifteen hundred feet in breadth^ and filling several 
deep ravines. 

*^ On reaching the first houses of the town DeBtroysTom 

del Greco. 

tiie stream divided^ according to the different 
slopes of the streets, and the degrees of oppo^ 
sition presented by the buildings. An idea may 
easily be formed of the accidents consequent on 
such a flood of fire ; accidents which bear rela- 
tion to the site of the manufactories, the thick- 
ness of their walls, and the manner in which they 
were assailed by the lava. Had not the mass of 
the stream suffered a diminution, from the differ- 
ent diveigencies noticed, not a single house 
would have been left standing in Torre del 
Greco. The lava, after a serpen tine^ course 
through the town, at length reached the sea* 
shore. The contact with the water diminished 
the speed <^ its course : still the current flowed 
into the sea in a body 1 127 feet in breadth, imd 
advanced into it a distance of 362 feet. Its en» Eotmneeiatt 

the 

trance into the sea was not* marked by any sin- 
gular phenomenon ; it began to issue from the 
volcano at ten at ni^ht, and reached the sea- 
shore by four in the morning; continuing a 

VOL. II. « I 



48SI DOMAIM Xll. VOLCANIC* 

very, slow progressive movement into, the sea 
throughout the whole of the I6tb» and the fol- 
lowing pight. It was conceived that the sudden 
cooling of the lava in the sea would . have pro- 
duced a basaltic construction; but it. became 
firm without assuming any regular . fonn> an 
effect which possibly is to. be ascribed to the 
heap of drosses with which it abounded*. The 
main stream» from the point where it issued from 
the volcano to that at which it stopped in the 
sea, measured 12,961 feet. Its breadth varied 
greatly; in some places it scarcely exceeded 
322 feet, but in the plain it spread to 1111 ; and 
at a medium, without risk of any great error, it 
may be computed to have. been 725 feet broad. 
In thickness also it differed according to the 
depth of the hollows it filled : in the plain it was 
constantly from twenty-four to thirty-two feet 
thick ; and if its mean thickness be reckoned at 
the latter number of feet, it may possibly be 
nearest the truth. According to these data the 
mass of molten matter is l,8^jS27 cubic fathoms. 
c«DTttUions. During the eruption the convulsion of the moun- 
tain was so great that even the houses in Naples 
were shaken by it. Still it was not constantly 
alike. At the beginning the trembling was con- 

* The explanations of Ferraia are better. P. 



VOME VII. TOLCAltIC INTRITI. 483 

• 

tinual, and accompaiiied by a hollow noise^ 
similar to that occasioned by a river fiBdliog into 
a subterranean cavern. The lava at the tune of 
its being disgorged^ from the impetuons and un» 
interrnpted manner in which it was ejected^ 
by striking against the walls of the vent, occa* 
sioned a continual oscillation of the mountain. 
Towards the^ middle of the night this vibratory 
motion ceased> and was succeeded by distinct 
and repeated shocks. The fluid mass, diminished 
in quantity^ now pressed less violently against 
the walls of the aperture, and no longer issued 
in a continual and gushing stream, but only at 
intervals, when the interior fermentation elevated 
the boiling matter above the mouth. About 
four in the morning the shocks began to be less 
numerous, and the intervals between them ren- 
dered their force and duration more perceptible. 
One might compare them to the thunder heard 
in Italy during storms in summer, the loudest 
claps of which are succeeded by rumbling sounds 
which gradually die away. 

^' While I . was making my observations on 
this grand eruption at the foot of Vesuvius, its 
summit was tranquil, and no phenomena were 
visible about its crater. I passed the night at 
sea, between Calastro and La Torre, to have a 
nearer view of this great operation of nature, 

2 i2 



484 l>01IAI« Xtl. TOLCANIC. 

and to prove the truth of the opinion generally 
received) that great eraptions bt^ accompanied 
s^iimityof \^y extraordinary phenomena in the sea« A 
more grand spectacle there could not be. On 
one of those serene imd brilliant nights^ known 
only in the delightful climate of Naples, a ma- 
jestic stream of fire, II9868 feet in length and 
1483 in breadth, was seen at the foot of Vesu- 
vius. Its reflected surface formed in the at- 
mosphere a broad and brilliant aurora borealis, 
regularly spread, and terminated at its upper 
part by a thick and dark border of smoke, which, 
dilating itself in the air, covered the disk of the 
moon, the shining silvery light of which wu en- 
feebled and obscured. The sea again reflected 
the illuminated sky, the surface of it correspond- 
ing with this portion of the atmosphere appear- 
ing red as fire. At the source of this river of 
fire inflamed matter was incessantly spouted out 
to a prodigious elevation, which, as it diverged 
on all sides, resembled an immense firework: on 
the sea-shore, finally, the mournful spectacle of 
the conflagration of La Torre completed the 
picture. The vast clouds of thick black smoke 
which rose from the town, the flames which oc- 
casionally Crowned Uie Summits of the houses, 
the ruins of the. buildings, the noise of the falling 
tpalaces and houses^ the rumbling of the volcano^ 



NOMB riU yOLCANIC IHTBITB. 485 

% 

these were the principal incidents of this hot* 
rible yet sublifne scene. The ruins of Pompeia, 
buried beneath heaps of drosses and powders^ 
did not certainly present a spectacle near so 
striking. To these objects^ so powerfully cal- 
culated to fix the senses^ was added another 
which forcibly touched the heart; this was a 
doleful group of fifteen thousand persons^ be* 
wailing th^ destruction of their city and pro* 
perty, who had had but a moment's notice to ' 
flee^ and abandon their homes for ever; and 
were reduced to become wanderers, and de» 
pendent on the world for refuge. 

« 

*^ About dawn the summit of Vesuvius ceased ciand of 
to be visible ; it was covered with a thick cloud, 
frequently furrowed with lightning. This cloud 
gradually spread itself, and in a little time over- 
shadowed the gulf, the city of Naples, and Its 
vicinage. It was formed of a large quantity of 
that fine sand called ashesy and prevented all 
sight of the fire of the volcano. The sun, as it 
appeared above the horizon, presented a still 
more dismal picture. From the abundance of 
ashes in the air it seemed more pale than during 
the strongest eclipse, and a black scarf appeared 
to be spread over the whole of the gulf and the 
country. At the extremity of the horizon, to* 
wards the west, the day was more cleari while 



powdcft. 



486 DOMAIN 3Llt. VOLCAHXC. 

the light at Naples was fainter than twilight ) 
and with Pliny the younger one might have 
said ^^ Jam dies kilibiy iHic nox omnibus nigrior 
densiorque.** 

Sea calm. <« During this mournful night the air was per- 
fectly unagitated) and the sea calm : it was not 
disturbed even in the slightest degree, at least m 
the gulf of Naples. The slightest action of the 
volcano on it would have been perceptible at the 
base of the mountain, and I was within a distinct 
view of this part of the sea; but its influence on 
that element was absolutely null. 

^^ " While one current of lava flowed over the 
western flank of Vesuvius, spreading ruin and 
desolation, another fell down its eastern slope, 
from an opening at an inferior height, and a 
greater distance from the summit. This current 
was not visible at Naples ; all that was perceived 
of it was a great light in the atmosphere, pro* 
duced by reflection from the rolling fire. At 
first it took an eastern direction, turned after* 
wards to the south, and descended to the spot 
called Cognolo; there it fortunately found the 
valley of Sorienta, 65 feet wide, 121 deep, and 
1627 feet long. This valley the lava filled; but 
as the volcano still continued to emit fresh mat- 
ter, the current afterwards spread into the plain 
of Forte, near to Pozzelle, where it divided into 



NOME VII. VOLCANIC INTBITB. 48? 

three branches : one proceeded towards Bosco^ 
another towards Mauro, and the third to the 
plain of Mulara. The length of this current of 
lava was not less than an Italian mile; bat as it 
flowed constantly over old lavas it did but little 
harm, merely laying waste and occupying a 
small extent of vineyard. From the spot where 
it diverged from its first direction it projected a 
small branch in a continued line: falling to this 
point over a very rapid slope, the speed with 
which it flowed must have been considerable} 
and a portion of its mass preserving itS' first im- 
pulse, naturally fell in this small stream, in which 
were four mouths in the shape of an inyerted 
cone, the base of which is in the surface of the 
lava. This stream terminates in a small and 
regular hill, of a conical figure, on the summit 
of which are two mouths, in form of inverted 
cones. The dimensions of this second current 
are nearly half those of the first ; consequently 
the mass of the whole is adequate to 2^804^440 
cubic fathoms. The coincidence and perfect re- 
semblance of these two currents of lava sufii- 
ciently prove that they had but one common 
origin, and but one cauldron in which the mat- 
ter was fused of which they are composed. 
How great then must be the recipient in which 
such an enormous mass could be contained! 



488 DOilAlW ZII* VOLCAWZC. 

"I^l^^^® And what powerful exertion of strength must 
haye been required to break through the moun* 
tain in these two opposite directions ! The laya^ 
agitated l>y the expansion of elastic fluids^ made 
its first effort to liberate itself on the eastern 
flank, and found a passage ; but the resistance 
it met with from the mountain, no doubt occa- 
sioned its reflux, or rebound, against the opposite 
flank. The western current, taking its departure 
from a more elevated mouth, more quickly ter- 
minated its course^ but the cauldron chiefly 
emptied itself by the eastern opening. The lara 
issued from it very slowly, compared with the 
celerity with which that flowed which proceeded 
from the eastern mouth, because it was no longer 
driven forward nor compressed by the total mass, 
which was already greatly diminished. 

Attendant «< On the morning of the I6th the lava ceased 

phenomenu 

to flow over the western side, and the month of 
the . volcano began to resume activity^ The 
whole of its cone was covered with a very thick 
rain of ashes or powders, which totally hid it 
from sight, so that nothing could be distinguished 
on Vesuvius, which was wholly inaccessible. In 
this state it continued four days, during which 
many shocks of earthquakes were felt, and loud 
'^KStohi?^ claps of thunder were heard. Thunders raged 
in every part of the adjacent country, and the 



HOMB Til. VOLCAVIC IHTRITB* 489 

flakes of lightnii^ by whicfa they were accom- 
paniedy at intervals for an instant, allowed a view 
of the znoontain, through the darkness in which 
it was involved by the rain of powders. This s«rime«. 
darkness was so prodigiously great, that at Caserta 
and other places, ten or twelve miles from Vesu* 
vius, it was impossible to' walk the streets at 
mid-day without torches, and that circumstance 
was renewed which is related by Pliny on the 
occasion of the eraption in the time of Titus, 
^^ faces multa, variaque luminal sohebant obseuri^ 
tatemJ^ It is utterly impossible to determine 
with precision the quantity of ashes or powders 
that fell in the course of these days/ as it was 
different in different places, accordii^ to the di« 
rection of the wind ; it is however computed, on 
the base of observations at different places, that 
fourteen inches and six lines in depth fell on an 
area, the radius of which is three miles, the sum** 
mit of Vesuvius bein^ the centre, 

^* It would be erroneous to conclude that all Ra« o^ the 

crater, 

this mass of matter proceeded from the entrails 
of the mountain ; the greater part was the off* 
spring of the ruins of the crater, which during 
these last days fell into the abyss below. A rain 
of ashes, when continued for any length of time» 
is very injurious to vegetation. Lands which» 
a few days before, presented the most smiling 



490 BOMAIN XXI. VOLCANIC. 

aspect, and were enriched with every kind of 
fruit, assumed a similar appearance to what 
would have been occasioned by the sharpest 
^^rtil*" winter. Happily hope, looking forward to the 
future, found consolation ; for these ashes are 
excellent compost : and though the husbandman 
lamented the destruction of the fruits and the 
vintage of the year, he already reckoned for 
recompense in the promised abundance of sue* 
ceeding seasons. As these ashes contain no 
element injurious to vegetation, their bad effects 
are purely of a mechanical nature. Mingled 
with rain water, as is their condition on an erup* 
tion, they form a pa^te which, collected on ve«» 
getables in great abundance, destroys by its 
weight their more tender organs, and bend.'t 
down their branches, which either sink or break 
under the w^ght, according to the nature of 
their fibres. They moreover form, especially on 
leaves and fruit, a crust which absorbs a greater 
degree of caloric than them, and retains it a 
longer time, thus prevenping the transpiration 
of the plant, and destroying its economy. 
7*T«Sif* ** I merely use the word ashes to accommo* 

improper. *^ 

date myself to the general custom. The impro- 
priety of the term is evident, as the substance 
has not the slightest affinity to the ashes of ve^ 
getables. It will therefore be better for th^ 



NOMB VII. VOLCASIC INTAIT8. 491 

JTutore to distinguish it by the name of volcanic Voicdodcund. 
sand, one which already begins to be common. 
On examining it with the microscope, this sub* 
stance is seen to be composed of particles of a 
rough and earthy appearance, mingled with tri- 
turated fragments of felspar and augite. All are 
not alike^ some being of large and others of 
smaller size. The grains are often of a dark 
grey colour, inclining to black; sometimes, and 
especially on the last days they fell, they were 
of a brighter ash-coloun It is constantly ob* 
served that, when the volcanic sand that falls is 
of a whitish colour, the eruption is near its end: 
This white colour of the volcanic sand may be 
derived from two causes; a greater trituration 
and tenuity, as in the instance of green glass, 
which when finely pulverised becomes white, or 
A longer exposure to the action of acid vapours. 
The sand ejected by the volcano, in the earlier 
stages of its eruption, issues from a furnace full 
of matter; but the vapours, as it begins to empty, 
have room to act with greater effect on the re- 
maining substances. Some particles of this vol- 
canic sand placed t>ver fire effuse a perceptible 
innell of sulphur; others, lixiviated, yield a mu«- 
riate of soda or ammoniac, or the sulphate of 
jron ; aj;id often two or even the whole of these 
salts are produced from the same sand. Th^ 



492 



DOUkin XII. TOLCANie. 



state of 
atmofphere. 



earthy matters which predomiaate are argil and 
silex. 

^^ It might be imagined that the phencnnena 
of this eraptionj and especially those which took 
place from the evening of the 15th to the 20tfa» 
would have a considerable influence on the st^ 
mosphere of Naples^ yet the meteorological ob« 
servatioDs, communicated to me by the astrono- 
mer Casselli, prove that the barometer had ex- 
perienced no material alteration, Casselli made 

Bannneter. use of an English barometer, divided into inches 
and hundredth parts. From the 11th of June 
to the 15th it maintained itself between 29,61 
BXid 29,58. On the l6th and 17th it was sta- 
tionary at 29y60. The 18th it varied from 29,56 
to 29y52. The 1 9th from 29,50 it rose to 29,51. 
TheSOth it stood si 29,46. The 21st between 
29,46 and 29,49. I conversed on this subject 
one day with Cotte, tolerably well known by his 
meteorological observations, who considered it 
as a very extraordinary circumstance. We were 
at the time at the house of Lametherie, who 
showed me a memoir on this subject written by 
M. de Buch, a learned mineralogist of Prussia, 
inserted in the Journal de Physique of Thermi- 
dor. An 7f under the title of Considerations swr 
k barometre, in which I found the following 

account, passage, which to me seemed curious : ^ Vesu- 



HOMS Til. TOLCANIC IMTtlTB. 403 

yiu8 in 1794 teemed as if about to engulf all na- 
tare ; the earth shook ; horrible roarings threat* 
ened the destruction of the country^ a dark 
night overshadowed the land; ashes fell to a 
considerable depth; flames and smoke rose to 
an elevation seven times as great as that of the 
mountain^ that is to say, to a twelfth part of the 
height of the atnu>sphere ; vivid lightnings flash- 
ed in every direction, and the atmosphere denoted 
an abundance of negative electricity, never ob* 
served during the reign of tranquillity ; torrents 
of rain committed dreadful ravages on the fruits 
of the industry of man; and every meteorologi* 
cal instrument underwent the greatest alteration, 
the barometer alone excepted; this, like the sage 
among worldlings, took no part in the confusion 
by which it was surrounded, but on the contrary 
seemed as steady as its partners were wavering, 
agitated, and unquiet. It required the most 
practised eye to distinguish throughout ten days, 
in which nature experienced the most dreadful 
convulsion, the slightest imaginieible variation of 
this instrument.' 

<^ At length the rain of volcanic sand having 
ceased on the 20th, and that which was spread 
through the atmosphere beingdispersed, Vesuvius 
itgain became apparent; but its appearance with 



494 



DOMAIN XII. VOLCANIC. 



Fall of the 
iiinniliU 



Globular 
clouds. 



Of droflses 
and Band. 



reason occasioned surprise^ for its summit bad 
fallen in» and its mouth was considerably en- 
larged. 

. ** Considerable eruptions evdived from it of an 
entirely different nature to those by which they 
were preceded. From the crater thick globular 
clouds issued, of such huge dimensions as to fill 
the whole cavity. Their surface appeared to be 
granulated like the head of a cauliflower ; and^ 
in proportion as they arose, they seemed to di* 
late . and extend themselves. When the sun 
shone on them their irregular edges were of a 
whitish colour. In the body of the cloud were 
discerned substances .of a greater specific gra- 
vity, which fell down again, unable to continae 
their ascent. Scarcely did one cloud proceed 
from the mouth before it was followed by? an* 
other, so that the cone of Vesuvius was fre- 
quently crowned with a multitude of these volu- 
minous clouds, continually fed and renewed by 
those which issued from the crater; and which 
rose to a height continually increasing till it 
exceeded that even of the mountain itself. These 
clouds were composed of fragments of ancient 
lava, and the rubbish of drosses and volcanic 
sand, projected into the air by the force of the 
explosion s and as one eruption scarcely 



NOU£ Til. VOLCAXIC INTBITX. 493 

taotfaer, the immense quantities of stones, which 
struck against' each other in the air ; those which 
lell back into the cauldron, and those which from 
a prodigious height fell on the external walls of 
the volcano, produced a most frightful uproar. 

^ Such was the state of the volcano to the 
/»th of July ; and during the whole interval an- 
other meteor occasioned incalculable damage to 
the fields in the neighbourhood of Vesuvius: 
this was rain, which for a fortnight was inces* Heavy rain<. 
aant, and mostly so violent that it laid waste th^ 
best grounds of Somma, Ottajano, and Bosco. 
Whenever a cloud appeared above the horizon, 
it seemed to be attracted by the volcano, and 
scarcely did it touch its summit ere immense 
streams were visible, precipitating themselves 
with horrible roaring to the base of the mountain. 
These impetuous torrents of water, mingled with 
volcanic powders, overturned the bridges, har^- 
rowed up the roads, tore up trees by the roots. 
Bud bore them along in their course, carried 
away houses, and utterly devastated the fields of 
one of the most rich and flourishing countries 
in the worid. For the space of a fortnight its 
unfortunate inhabitants were in a state of un- 
certainty, respecting their late, and were repeat* 
edly forced to abandon and flee from their dwell* 
ingSy in the very dead of nighty to preserve their 



4d6 



IKMIAIW ZII. TOLCAVia 



Mcphitic 
▼apoon. 



lives. The appearance of the smallest dond 
occasioned general consternation. 

^^ Nor did the series of calamities which ae* 
companied this fatal eruption terminate here* 
In different parts around the mountain, power« 
ful mnrtherous vapours, of a mephttic nature, 
were exhaled. These manifested themsdres, 
not only in the greater part of the cellars of the 
houses of Portici and Resina, but q>read through 
the country, carrying desolation in their train, 
and destroying all the trees, which then were ia 
the finest state of vegetation. They showed 
themselves in the different roads cut to ascend 
Vesuvius, and occasioned there the death of a 
number of animals, and even of some men. It 
was certainly a most afflicting scene to behold 
vast extents of ground in the highest state of 
culture, which fortunately had esci^ed the ra- 
vage of the rainS) become in the space of a few 
days the prey of this terrible scourge, and all 
their verdure and all their trees withered by the 
baneful gas. 

wad^^^ " ^ ^^^y extraordinary phmomenon, and 
one highly worthy the attention of the natural- 
ists who make the vegetable reign their study, 
accompanies this mephitic vapour: though it 
destroys all other vegetation^ and causes even 
the roots of other plants and trees to perish in a"^ 



KOUt Vfl. VOLCAniti INTfclTt. 497 

few days^ it neither ' injures the olive nor the 
pear-^tree) whieh^ in the midst of the general de* 
stniction, constantly retain their verdure and 
^tfength.' This is a fact c6nfirmed by all farm^ 
ersi and which I have many times -verified my-* 
self. • 

^* On examining this mephitic gas by the or<» Gas. 
dinary means^ I found it to be composed of car* 
bonier acid gai> azotic gas, and a portion of sul- 
phuric acid, as is shewn by the precipitation of 
barytes, by the solution of muriate of barytes. 
The bad effect, therefore^ of this gas on plants, 
is little matter for wonder, the deleterious nature 
of (Jarbonic acid to the vegetable reign being 
known. 

** The colour of the lava of 1794 is a darkish lata of 1794, 
greyy its hard^e^s such as to yield sparks with* 
steel, its grain coarse and earthy, its fractlire ir- 
regular^ its porousness various, for in soine parts 
it is ?o compact as to resemble petrosilex in itj^ 
grain ; on moistening it, even by breathing, or 
on being wetted, it exhales an earthy smell r^ 
finally, it-powerfully answers the magnet. Sel- 
dom is micafound in this lava in I&minae, but 
often in groups and small united masses; on 
these occasions it presents the same phenomena' 
as in the lava of Granatello. The lava is rich in 
augite, which is frequently seen crystallised in 

VOL. II. 2 K 



ita ca^yities^ Md often a)3Q ioteniMiai: with muA. 
Near tbe orifice* of the voloaino d^^tacW ory*^ 
%9^ of aogite are found in i^bundaBce ; tbejr be« 
long to those drosses and|KH*onft ^r^, whiehtbe 
violence of the ytipoursji in the vicinity oif th» 
mouths, has decomposed without affecting th# 
Wgite." 

From the description ci this cdebrated y^- 
cano it is now proper to pass to its most peci^ 
tiar production. i 

RYPONOllfB t. LAVA WITH LBUCITB. 

This abounds in the ni^ighbourhood of Vesu* 
vius, particularly in the more ancient eruptions ; 
Of P0Bp€iB, and the streets of Pompeia, built when that yol- 
cano was extinct, were found to be payed with 
this. Uya* Breislak employe a chapter in the dis- 
cnssion of teucite, winch is common iu the an- 
cient lavas of the tenitory of Naples and Rome*. 
There is aa invnense quantity of leucites in tbe 
AibiM. oiountaina of Alhaqoi Tivoli, Caprarola^ ViterhOi^ 
Aquapwdentey Ciyita CasteUana, and Bor^tto* 
Thisy often occur in compact lava» sometimes in 
tbe vesicular, and cyan m the dross, which de« 
connposinft Imv^s the crystals sepwr^ Tbey 9X^ 
fywA in tbfi calcareous rocks of Sonimai whkk 

* VViyage dftngla Camp^fe, tome IL 



499 



MOMB fll.^ TOlCANtd IimiTX« 

mny be regarded as 4Rragments of a primitiye 
rock) ejected without having undergone the action 
of Tolcanic fire*. Leucites are often conjoined with 
lelftpar and aug^te ; tuid, like topaz, the earth of 
leocite may occur uncrystallised. 

MTPOKOJkfB n. LAVA WITH CALCARKOITS SPAB. 

According to Feifaray calcareoas spar abounds Femn's 
in the ancient or rather primeval lavas of Sicily^ 
Though the doctrine of infiltration begins to yield 
to that of contemporaneous sublimation by heati 
yet his arguments in favour of the former hove 
great weight; for when he afterwards mentions 
the zeolites found in the same basaltins, and the 
mdlcimes of Haiiy, (which he proposes to call c^«> 
cJopitcs^ because they were first found in the rocks 
of the Cyclops, and C4;>peared about the middle of 
last century in the cabinets of Prince Biscari^ and 
of the Benedictine monastery,) he observes, that 
^/ this substance has not only infiltrated and crys- infiitnted* 
talised in the most interior recesses of these &mv* 
mous masses of the hard lava, but io a great 
quantity in the slits andT in the middle of the marl| 
which forms a stratum above all these lavas ; a > 
convincing proof that its origin is posterior to tha 
liquid state of the lava, and foreign to that sub- 

♦ IfcM* H. 6*." 

S K S 



^QQ DOMAIN XIX. VOItCANia 

stance'*." That even the hardest metals aad 
other substances have pores of extreme minute- 
ness, undiscernable by the best microscopes, is a 
well known fact in natural history ; and gases may 
penetrate where the purest water may be excluded. 
^' Calcareous spars, or crystalised carbonate of 
lime,, is the most abundant substance in these an* 
* eient lavas. It is sometimes confusedly crystal- 
ised like stalactites, and like Ahem also with con- 
centric layers, which indicate the successive de- 
positions ; but often in solid globules, which per- 
fectly fill the cavity, as is generally the case with 
all the lavas of southern Sicily. I found some 
with those globules six lines in diameter, on the 
mountain of Carlintini ; and behind Lentini, near 
Ferla, there are masses of lava in fragments, in 
Sites. which these calcareous globules are so numerous, 
that they may be said to be conglomerated by a 
little argillaceous cement These masses are very 
friable, and the diameter of the globules varies 
with the size of the vesicles in which they were 
formed. I have also found them abundant in the 
lavas near Pedagaggi, Palagonia, and other 
places'. Many of these globules, but chiefly the 
larger, have a radiated structure, and may be ob- 
served to be formed by the union of several py- 

♦ Fcrr. 184, 



NOIIB Vlf, TOLOANIC IMTftlTE. JQJ 

rathids of three sides, joined at the centre, with 
diverging rays ; their bases forming the sur&ce of 
the circuniference, but ttiey are often covered with 
a spherical layer of the same substance, confusedly 
crystallised. Such are seen in the lavas of Murgo^ 
between Simeto and Lentini ; in the Rocks of the 
Cyclops ; and I have found them, from four to 
six lines in diameter, in the vesicles of the lava 
which is scattered in fragments on the chalky 
mountain of Cifali, near Catania, where they 
form curious £ELns Avhen gently broken. 

'^ But more commonly this calcareous sub- . 
stance lines the cavities under the stalagmitic 
form, in the shape of hanging crystals, or im- 
planted globules. I have beautiful specimens 
collected to the west of Lentini : some of the glo« 
bules are void, die inner surface being only crys- 
talised in what was formerly called the dogs-tooth 
spar, but now the mettutatic of that diligent crys* 
talographer Haiiy. Under the same form these 
spars line the cavities of the beautiful tufb around 
Cape Passaro, formed of fragments of lava and 
limestone, and many masses of lava alone ; and 
in the rocks of the Cyclops it is not only found in ' 
the cavities, but forming layers above the lava, 
and even above the stratum of marl which coters 
these famous rocks. 

^^ This substance is stiU more frequent in the otken. 



e«viti«9 of a hxard aiid compact lava, ia Ihe ne^jb- 
bouring HMMmtains of Tresaa, mi the faiU of <}]fidik 
and in the oeighboarhood of Paterno^ disposed ia 
beautiful starry crystals, formed of splendid py^ 
Itenidal plates, more or less^ transparent, unitad in 
the centre ; diverging sometimes with aggiegated 
fays, sometimes with distinct, and of various 
length; sometimes tbey are JBisciculan But the 
calcareous spar assumes a vast number of forms, 
of which it is enable. In the heaviest and most 
compact lavas of the rock oi M otta, the cavities 
ccncealed in . the mass, and which were formed 
while the paste was in a kind of ferment, are lined 
with the same substance, covered with many mii- 
nnte globules, but not visibly crystalised ; and I 
have found it in the same form in the lava on the 
high summit of the mountain of S. Vennera. 
• '^ This calcareous spar may be said to be alwa^ 
white ; but the iron proceeding from the decom* 
position of lavas, often tinges it with various co- 
lours, from blood-red to deep brown. I have 
found some at Favarotta, near the lake ci Palici, 
which could not be distinguished, except by the 
chemical test 

^' At no great distance from the mountain of Fa« 
temo, there is a vast heap of large masses of lava, 
containing crystals of felspar, where there art 
some cavities filled vnih calcareous spar in bright 



^llqr (te^MMfe eiF iiMquai letigth) united in taatts, 
with div^rgkig rays ; but the diief ditigularity is, 
Ihftt all the imurs is full of pMroli wfaidi als6 fills 
tMny of tbe cavities. On breaking this lata the 
iM runs out, which, though of a blacic colour, is 
so subtile as tb approach naphtha, with a pungent 
smell, whid^ it soon loses in the air« There seems 
no reason to doubt lliat this petrol has been pro** 
duced by infiltration *.•* 

HVFONMIB ttl« INimaATBly MOD WlTfi VltUtAtL^ Wi^ 

DBRTIB, &C« 



NOME vm. VOLCANIC GLUTENTTE. 

. This dQaominaticm ioclades, as usuftlt what 
are called bripias and pudding'Stones^ being 
fragmei^to of different ro^ks joiaed by lava or. 
tufo. Tbe p^perino of tlie Italics is a volcanic Pcpttjno. 
briota; the cetnaat being a gr^ poviaceous 
tplbj in which are c<mcreted fragipents of gra* 
nitej lelsite> marble^ gypsum) with crystals of 
siderite and ipica. In the ettinct volcano of 
Beaulieuj three leagues to the N. W» of Aix in . 
Proyence» Saussure observed a singular pud«* 
ding-stone, composed of fragments of vesicular 

• Fcrran^ 17&. 



lava, mingled with others of a violet >colour9 «iid 
bits of white limestone ^, . Dolomieu desGribes 
Bridas. ^ sihceous lava^ which is a bricia of •iUcejNi^ 
sttbstaDces and pumice. . In another pfs^age he 
seema to doubt whether Etna ever had any-erap* 
tions of mud, so common in the coatinental voU 
canos of Italy, and wbipbf according to him^ 
have fonnpd stones of an ar^Uaceou^ ^ase caUed 
peperino ; nor are there any brtcias called .tufo» 
fyrmed in the water by volcanic ejections f. He 
howeviar describes a glotenite c^ fnagments of 
compact lava, black clay rock, and spathose 
iron ore, cemented by a clay with red and white 
Teins. What is called leucite lava is a glutenite 
of those pr^stftls, cepented by tufa ^r compact 

lava. 

Tufo itself may be regarded as a glutienite or 
volcanic sandstone ; but in this instance forms 
so important a feature ' of volcanic etuptions^ 
that it has been considered apart : so that the 
present division must only be understood to com- 
prise what are called large-gralued glatenites, 
though in some instances tuib may pass into 
bricia. In' his classification of volcanic sub- 
stances Faujas has joined them together; but 
^is account shall be transcribed, as it presents 

• $ 1529. 

I Ponces, 106, Etna 354. But^ compare Ferranu 



Nom irtu. yoicA^ic qsvtbnitb. ^05 

jome institKittTe remarks and interesting sin]B;ii'« 

larities : and the extreme intntiteness of the de^ 

9cri{»tiODS will serre fiillj to instruct the reader 

IB the nature of these complex substancesr the 

mingled products of fire and water*. 

» 
'^ Division 1. Brii;ias, whose formation is Ca^ioipieby 

owing to lavas, which in tlieir state of Jiuidity 

have embraced other kinds of lavas, whether com-s 

pact or porous, scorified, vitreous, or other stony, 

substances reduced into fragments. When the 

wbstances thus imbedded present kernels more or 

less angular qf a certain size, and the lava which 

unites them is hard and soUd, they may be called 

volcanic bricias. ]f, on the contrary, the frag^ 

mpnts are very small, and the paste which sur* 

rounds them is friable, soft, and rather earthy 

than stony, tlie name ttffo is more applicable. 

'^ 1. Volcanic bricia, formed of angular and From fin. 
vound fragments of black compact lava^ of black 
lava rather porousj and some grains of white fel- 
8p^> strongly'^nited by a very hard granular 
I^vai of a reddish coloiil*. 

4< S. Bricia^ formed of angular fragments of 
black lava» bard^ with small pores^ united in a 

* This IS also from the AnnaUi du Museum. In the Geologies 
opfffjQMOy ({elivereA at a course of lectures* it is moch abridged. 



fiae paste of reddish fatm» wiwch fa>d m U m dttS Sf 
to pass to the state of pairiice* 

^* 9. Bricsay similar in aspect to tlie precMhtg^ 
but different from it in as mnch as the firagsietitt 
of black lava, instead of being ponom^ aM in the 
state of semi-vitreous drosses^ of a very bright 
black. The gfej paste which unites this bricia, 
and gives it a strong consistence, is composed 
of fine particles, but rather scaly, very neatly 
allied to hard pumice. 

** 4. Bricia^ formed of angular fragments of 
black porous lava, of some small grains of white 
felspar, opake, blended in a pttste of grey pu- 
mice with small pores. 

" 5. Bricia, with angnlar iragments of white 
calcareous stone, grey and sometimes reddish, ot 
the nature of marble, capable of receiving a po- 
lish, every where and in every direction enclosed 
in a grey lava, bard, sprinkled with fragments 
and crystals of wKtte felspar, diaphanoos and 
shattered, of black horriblende, with some grainar 
of pyroxene of a grass green, and with some 
spangles of silvery mica : this last is found In it 
in a very small quantity. This bricia is hard 
enough to be sawed and polished : it strongly 
attracts the magnet. 

<* 6. Bricia, with large fragments of white 



VOMB.irni; TOLOAWO OWTftiriTB. ^10^ 



iiiafbie> of ydlowish marble with a fitie 
grain^ which takes the pdish ; of grey atone of 
a wery fiae pasted which cannot be scratched by 
flieely but which nevertheless effervesces briskly 
with nitrous acid : it seems to be stliceo-caica^ 
nous. The different fragments of these stones 
are imbedded in a grey lava, rather earthy, but 
•otid, mixed with many black pyroxenes, divided 
into very small fhigments. 

*^ 7. Bricia, with fragments of white and grey 
marble, and some kernels formed of a mixture 
of clear felspar, and a black 4N]bstance which has 
some resemblance* to hornblende. Conglome- 
rated nodules of black mica are alto found in it. 
The several foreign bodies are imbedded in a 
grey lava, which contains in great abundance 
small fragments of pyroxene, of a brilliant black 
in appearance, but which, observed with a lens 
in a strong light, are found to be green : some 
strongly marked ciystals of that substance are 
even distinguished, which are diaphanous and 
of a grass green, and some spangles of silvery 
mica. 

*^ 8. Bricia, with large nodules of volcanic 
chrysolite, of a greenish and yellowish colour, 
mixed with large fragments of porous lava, and 
of black compact lava almost scorified, cemented 



'508 BOMAIN XIL rOLCANlC. 

by a grey lavsi, whidh itself contains a number 
of sandy grains, of black lava. 

'' 9. Bricia of a yellowish base^ with very 
jafge fragments of a black compact basaltic 
lava, filled with vitreous grains of chiysolite of a 
yellowish green, and a number of smaller, fi^g* 
ments of black lava with small pores, some <^ 
which are vitrified* The yellowish and rather 
earthy lava, which cements this bricia, contains 
eome' grains of black pyroxene, which seem to 
have been melted ; and of flaky felspar> changed 
and of a dirty white. 

« Division 2. Bricias^ or volcanic tufos^Jbrm^ 
cd by the cdncurrence of , fire and watery carried 
to the highest degree of temperature : the water 
introducing itself by some subterranean comfnuni^ 
cations into the burning centre ofvolcanos^ has pro- 
duced results and particular combinations^ which 
. partake of the contrary properties of those tzvo 
elements. 

nAtt^T ^* ^* Bricia of an ashy grey base, formed of a 
number of fragments, rather porous, of black 
basaltic lava^ mixed with many grains' of chry- 
solite, of large fragments of quartzose. sandstone 
with parallel zones, white and r^d, irregular 
pieces of hard grey marl, reddish in many parts, 



NOMB TIU. VOLCAVXC OLVTBHITK. jt09 

and of some geods with a crast of brown hema- 
tite» which seem to be the result of the infiltra^ 
lions of a marl, which is found in pieces in this 
bricia, and which is strongly impregnated with 
iron. 

'* 2. firicia, formed of fragments of brown 
parpktfrjfi and of porphyry with a red base, with 
parallelopiped ciystals of white felspar, frag* 
ments of white marble, surrounded in their points 
of contact with black lineaments, which seem 
to be the result of an aqueous dissolution, which* 
has intimately united all the parts which com- 
pose this singular bricia. The grey lava which 
forms its base, and which contains some grains 
of Mack melted pyroxene, is so amalgamated, by 
the assistance of calcareous infiltrations, with 
the other parts of the bricia, that the whole 
forms a substance capable of being polislied^ 



Division 3. Bricias, or volcanic tufas, fanned 
by ejections of substances reduced to pieces, to 
grains, or to powder, sometimes carried to a dis^ 
tance by explosions and by the winds, afterwards 
uniting, whether they fall into the sea, or are de-'- 
posited in places where the rain water consolidates^ 
them, as at Pompeia, and elsewhere. 

^* 1. Volcanic tufo, which owes its origin to tvom 
showers of black and grey pumice, divided into 



^(0 . tMUMK SK« TOX^CASfC. 



fiagmeiite th6 size of an olive, and ao i rt imes of 
a nut, adhering hj tbe points .of contact, the 
natter which nnites them not being distingoirii* 
able. This tnfo is exceeding light, but not of a 
strong consistence. 

*^ 8. Tnfo, whose base is a pumice reduced 
lAto so fine a powder that it has the appearance 
of an argillaceous substance : this nnites a num* 
ber of very small grains of pumice, dryer, harsher 
to the feel, and much less altered, and very dis^ 
tinct pieces of porous lava, although partly dis^ 
odbured. This tufp forms one of the varieties 
of trass of Pleyt, in the environs of Andernach* 
What I have said of it in a distinct memoir majr 
be consulted, in which I have described the se# 
veral considerable quarries of these tarrasses, 
which are wrought to be converted into cement. 
See Anmaks dm, Museum^ vol. i.p.lS. 

*^ 3. Tufo, formed of a mixture of pumice in 
powder, or in grains, angular fragments of black 
compact basaltic lava, and small scaly fragments 
of a grey schistus, rather shining, not volcanic^ 
which has been cast up with the other sub* 
stances. It is in this variety of tufo, which has 
much more solidity than the preceding, and 
which has formed beds and masses more thaa 
fifty feet thick, that there are sometimes feund 
cylindrical pieces of real charcoal, as sound and 



NOM£ nu« TQicAirK: a^vmriTB. Jill' 

waD prcsenrcd m if tbiry had kibdjr been pre« 
pitfttd. Sea what I have said of this curioiui 
laiietjr of trass of the ennrons of Aadeniich,^ 
vol. i p. 24f of the Ankales du Museunu Spal^ 
laiuwii fooad a similar charcoal in a tufo of the 
isle <A LiparL See aho to(» iiu p. 11, of Spal- 
laaaaoi*s Vcgfoge to SicUf. 

^^ Of the particular configuration peculiar ta 

some ti(fos. 

^' Ni^e^^^lt flmst be observed, that under son^ 
CirciHttstancas tnfo^ particalarlj those whidi 
owe tbejr ocigin to the coneunDence of fire and 
water, have undergone a recession whi^ haa 
given them a prismatic form. I have seen simi* ^SSmnT 
lar onefl^ bit ia sowU quantities, iu the extinct 
volcanos of ifabisohwaJd, near Hease €assel. 
The most remarkable of this kind are thesa of 
Campania^ near the town of St, Agatha, also 
hetweea Mounta Sarckio and VitoUim\ near a 
plaee called La Varrettdlar but the largest and 
the best formed are those which are found on the 
road to Venafro^ near the bridge of Calvi and 
the tavera of TorrfeeHu. 

^ ChalcedooTc substances are sometimes found ctektitoy. 
in tufos, which seem to be the result of a second- 
ary formation,, snah as those of Pemi^dm^ 



512 DOMAIN XII. VOLCAHC. 

and .of some other parte of Auv^gbe^ wher«3 fine 
lentils of chalcedony, and chalcedonic crystal* 
lised quartz, are found* The perktein of Sancta 
Fiora, on the confines of Tuscany, is an aoalo'* 
gous chalcedonic substance, which is also found 
in a tufo ; and the muller-glass, which was dis- 
covered by Dr. Muller of Frankfort, and thought 
to be a glass, is only a very fine chalcedonic 
substance, with the lustre and transparence of 
glass. Muller observed this substance formed 
m drops on a porous lava*. I have found it on 
the tufos of Bocheneim, near Frankfort, spread 
like a shining varnish, and pretty thick, on the 
surface. 

*^ Of som^ substances of the organised kingdom, • 
which are accidentally found in tufos. 

^'^j^J^^ " 1. The fossil tusks of the elephant have 
been found in tufo in the neighbourhood of 
Rome, The Duke of Rochefoucault found one 
himself of a gigantic size, as it was eight feet 
long and fourteen inches in circumference : he 

* Faujas has added, Geol. ii. 147, that Mailer nid to hiin, 
*^ I have ififinite obligatknt to natural history, it charms my last 
moments, and the weight of ninety-Jive years, my present age, does 
not weaken its power. One has always fresh enjoyments, dne Bvh 
without Tepr90ch, emd 9ne does not die, buifriili asleep" 



VOM£ VIII. VOLCANIC QLUTXNITB. 513 

/ 

. I 

sent it to M. Buffon : it may be seen In one of 
the galleries of the Museum of Natural History 
at Paris. 

'* 2. The grinders and the thigh-bones of an 
elephant, were discovered iii the midst of tufo> 
in a vineyard not far from the Porta del Popolo 
at Rome. Count Morozo sent the description 
of it to M. de Lacepedty who inserted it in the 
Journal de Physique, vol. 54, page 444. 

** 3. In digging some years since, in a tufo of 
Mont Couerou, in the department of Ard^che, 
near the commune of Arbres, to find a spring, 
M. Lavalette found a tusk of a young elephant, 
half petrified, but perfectly characterised. On 
this subject I published an account in the An* 
nals de Museum, see vol. ii. p. 23, where the 
tusk is represented. 

*' 4. Different kinds of shells are found, as Sheiu. 
well univalve as bivalve, in sometufos; and these 
shells are scarcely altered. 

" The valley of Ronca, so well described by 
Fortis, and which he justly calls volcanico-ma* 
vine, in the territory of Verona, contains many 
shells in the tufo. 

'^ Dr. Thompson an English naturalist, resid« 
ing at Naples,' possesses in his rich collection 
some fine samples of tufos, which are found sCat« 
tered in dififerent places of Vesuvius. Some con* 

VOL. II. S L 



|;|4 BOKAIN XU« TOLCAine. 

tain marine .mbstaoces, and he has one in which 
18 dirtinguidied a madrepore, common in the sea 
of Naples ;Jt is the retepora spongites of Linneus, 
the poms anguinus of Imperati. 

** \ In the magniiScent gardens of the Elector 
of Hesse Cassd^.at Waissenstein, in the midst of 
a volcanic soil^ is found a sandy tufo> filled with 
beautiful shells of different kinds ; among which 
I observed the Venus islandica of Lamar ck> and 
the area pilosa of Linneus. 

*^ I possess in my collection^ a shell of the ge- 
nus cone, in a very hard volcanic tnfo, which 
has filled its interior, found on the sea shore at 
St* Croix, inXeneriffe; it was gi?en to me by 
M. Bailly, one of the mineralogists in the ex- 
pedition of Capt. Baudin. 

lignite. ** 5. 1 have already mentioned wood changed 
to coal, which is found at a great depth in the 
tufo, of the environs of Andernach, and in that 
of Lipara. 

Plant!. ^ 6. I ought not to pass in silence, the tufo 

of Rochesauve, in Vtvarais, of which the beds 
seem to alternate with other fossile beds of a 
fight marl, which contains leaves of trees and 
plants, whose fibres are in the most beautiful 
preservation, but whose parenc*hyme is black 
and carbonised. I have a numerous collection 
of those plants, which I gathered on the spot : I 



NOMB IX. fVBSTANCBS BJBCTBD OB CHANOBD. 515 

intend shortly to make them public, by having 
them engraved, and to give the explanations of 
those which hav6 relations with known species.** 

HTPONOMB L VOLCANIC HEICIA. 

The various kinds are already mentioned. * 

Microrwme 1. Peperino. 

From the environs of Vesuvius, &c.* 

Micronome 2. Leucite Lava. 
From Vesuvius, Albano, &c. 



NOME IX. SUBSTANCES EJECTED OR 

CHANGED. 

Many kinds of rocks are at various periods 
ejected by volcanoes; often with some marks of 
fusion^ but in many instances^ exploded by the 
vapours, without being visibly affected by heat. 
Whole masses of rock, nay mountains, are also 
found changed by the action of the sabterranean 
vapours, as the celebrated Puy-de-Dome, which, PnHe-Dome. 
according to Saussure \ 7SI8« 7299 is a porphyry 
with a base of earthy felspar ; and he found one 
of the same kind in the Valorsine. Mont Do^ 

* MmUe Nu»90 near Naples, ^aniists of indaratod powder« pa« 
mice, and fragmcntt of lava intcrmuiglfid, fbrming a peperino. 

St l2 



516 J>01fAIN XII. VOLCANIC. 



Stones. 



also' presents granite, evidently affected by heat, 
the felspar having become dull and shattered*. 
Several altered rocks are found in volcanic re- 
gions;' and even the lavas sometimes become 
white^ by the action of sulphuric vapoursf • 

HYPONOME I. LIMESTONE. 

This substance deserves the first place, as that 
ejected by Vesuvius is not only more firequent in 
cabinets than any other exploded rock, but con- 
FjM^tic tains several remarkable parasitic stones ; such as 
1. The Vesuvian of Werner, and idocrase of 
Hauy, the jacint of Vesuvius according to Saus-* 
sure, the colour resembling that of a pale jacint 
It is also found of an olive green, whence it is 
' sometimes called chrysolite by the Neapolitan la- 
pidaries. It v^rould seem that the latter is, how- 
ever, the same with the olivine of Werner, also 
called volcanic chrysolite p 2. The sommite of 

« 

* It is surprising that the French writers continue to spell d*Or w 
if it were the golden mountain, while Lc Grand (Voyage d'Ao- 
▼ergne ii. 66.) has deitKinstrated, that the name was taken from the 
liver Dor, which, with the Dogne, forms the Dordogne. 

t The lava decomposes into clay, or rather the aigil displays it* 
self; whence the environs of volcanos are very fertile. 

} Because the olivine is found in basalt, the Wemerians reject 
it from the volcanic substances, while it is in fact the common vol- 
canic chrysolite, as Breislak has shewn. Gioeni, p. 217* observes, 
thflt many scoriae of Vesuvius and Etna contain a yellowish substance 
like glass, pjsrfectly resembling that in the native irOQ of Siberia. 



VOME IX. SUBSfANCBS BJBCTBD OH CRANOBD* 517 

Karsten, the nephiline of Haiiy, of a white or 
greenish grey, found in the ejected rocks of Mount 
Somma, which may be styled the parent of Vesu- 
vius. Leucite is also found in the calcareous rocks 
of Somma, accordmg to Breislak : but the pyroxene 
of Haiiy, the augite of Werner, of a dark brown 
or green colour, rather belongs to granitic rocks. 

Limestone, with volcanic jacint and chrysolite, 
from Vesuvius. 

The same with leucite, from Monte Somma. 
Kirwan has strangely confounded the volcanic 
jacint, or vesuvian of Werner, with leucite or white 
garnet. 

Limestone with sommite, from Monte Somma. * 

HTPONOIIE II. GRANITE. 

■ 

In this substance the felspar, which, owing to 
the mixture of potash, is the most easily fusible, 
is sometimes either melted or shattered by the 
heat*. But the granitic lavas of Dolomieu, and 
other French writers, seem problematic. That 
patient observer says that he never saw them in 
such abundance, nor with such convincing proofs ' 
of having been fused, as at Sancta Flora, on the 
confines of Tuscany and the Papal territories. If 

* In the language of jewellers ilutwed, corresponding with the 
French ttonn^. 



518 AOIIAZVXXI. TOI.eAWIC« 

the ejected granite contains garnets, they are ocMn- 
monly vitrified. 

Saussure observed, § 730, the ejBTects of vitri- 
fication on granites in the lime-kilns of Chamouni. 
Those that have suffered the least heat, are known 
by the dull white appearance, and cracks of the 
quartz and felspar, and by the glossy golden 
lustre of the mica. In a greater degree of heat, 
the mica and felspar appear melted, but witihout 
derangement. In the greatest heat, the mica is 
melted into large round bubbles, while the felspar 
looks like glass with microscopic bubbles; and 
the quartz is only of a dull white, without any 
appeanbce of fusion. 

HTPONOMB Iff. MICA-SLATB. 

This sometimes accompanies ejected granites. 

HTPONOMB IV. SLATB. 

This substance b chiefly conspicuous among 

the ejections of Hecla. 

* 

HTPONOMB V. BA8ALT0N. 
HTPONOMB VI. PORPHTRT. 

These two kindred rocks are frequent in vol- 
canic countries ; and abound among the ejectiivis 
of New Spain, and other volcanic re^ons. 



MOMI IX. ftOBfTAIWBt BJtCTIB OB CHANOSO. $1^ 



HYPONOMB VII. tAKDnOMB. 

This substance seems one of the rarest of the 
ejections ; while, as it generally, if not always, 
accompanies coal, if the Wernerian theory of vol- 
canoes were just, it wouM be among the most 
common. 



This arrangement of volcanic substances bein^ 
from its nature, rather jejune, it may be proper 
somewhat to diversify it by a few general remarks^ 
and some examples of singular volcanoes, chiefly 
from Patrin and other foreign authors, whose 
works have not been translated. It mi|^ have 
been thought unpardonable to have passed, with 
irreverent brevity, some of the grandest features 
of nature ; especially as the recent progress of 
mineralogy has thrown new light on many topics ; 
and the ignorance of the ancient accounts has 
been dbpdled by the precision of modem science. 

Patrin has started a singular idea concerning ^|^ 
volcanic substances in general, which is, that they 
are created by gases ; otherwbe, in his opinion, it 
would be impossible to account for the vast quan* 
tity of matter ejected ; and the volcanic moun* 
tains would, long since^ have sunk into their own 



520 001U1V zii. .roLCANic 

abysses. He introduces this new system by the 
theory of that great astronomer and geometrician 
Laplace, that this earth, and the other planetary 
bodies f have been formed by the concretion of an 
aeriformjluid, rvhich emanatedjrom the sun. The 
account^ given by Dolomieu, of the singular per- 
petual volcano of Stromboli, furnishes our inge- 
nious author %vith his chief arguments in favour of 
this hypothesis. 
StromboiL ^* The volcano of Stromboli is one of the most 
curious and important in the illustration of vol- 
canic phenomena. It is in one of the isles of 
Eolus, on the north of Sicily; and Dolomieu's 
description is very interesting. This volcano was 
already noted in the days of Pliny ; and its erup- 
tions, from time immemorial, arise every eight 
minutes, so that it would seem that nature there 
displays every moment the concretion of gases 
into stoney matter, as a chemist shews it in his 
laboratory. 

' The inflamed crater,* says Dolomieu, * is in 
the north-iwest part of the isle, on the side of the 
mountain. I saw it dart, during the night, at re- 
gular intervals of seven or eight minutes, ignited 
stones, which rose to the height of more than a 
hundred feet, forming radii a little divergent, but 
of which the greater quanti^ fell back into the 
crater ; while others rolled even to the sea, £ach 



DOMAIN Xtl. . VOLCAMIC. 581 

explosion was accompanied with a burst of red 
flame . .* . . The stones ejected are of a lively 
red, and sparkle, having the eflfect of artificial 
fireworks/ 

'' I mast here remark that these sparkling 
masses with the effect of fireworks, announce that 
their base is combustible. 

^' Having visited the mountain on the following 
day, Dolomieu thus continues his description. 

* From a little. summit, you have a view of the 
kiflamed crater .... It is very small; I do 
not think that it exceeds fifty paces in diameter, 
having the form of a funnel terminating in a point. 
During all the time that I observed it, the erup- 
tions succeeded with the same regularity as during 
the night ... the stones ejected forming diver- 
gent rays ; and the greater part, which fell back 
into the crater, rolling to the bottom seemed to 
obstruct the vent, which the vapours had opened 
at the moment of the explosion, and were thus 
again ejected by the subsequent eruption. They 
are thus tossed till they are broken and reduced to 
cinders (coarse powder). But the volcano always 
affords a new supply ; and is inexhaustible in this 
kind of production. The approach of the eruption 
is not announced by any noise or dull murmur in 
the interior of the mountain ; and it is always by 
surprise that one sees the stones darted into the 



53 jl ]»oirAi» zii. voLCAKie. 

ain There are times when the eruptions are mom 
precipitate and violent : and the stones, describing 
more divergent rays, are thrown into the sea at a 
considerable distance. In general the inflamma- 
tion is more considerable in the winter than in the 
summer ; and more on the approach, and during 
the rage, of storms, than in calm weather/* 

'^ The author afterwards adds, that ^ Stromboli 
is the only known volcano which has such frequent 
eruptions. The fermentation of the others in- 
creases progressively, but here the eruption is con* 
stant .... and it would seem that it arkes from 
air or inflammable vapours, which suddenly kindle 
and explode, expelling the stones which impede 
the vent^t 

Patrin proceeds to argue, on his system, !• 
That the eruptions of Stromboli arise from a cause 
always reproduced, otherwise it would have been 
exhausted. 2. That the stony masses are instan<- 
taneously formed, by the contact of the air; as 
magic alone could always supply a like number of 
stones, and still preserve the precise form of the 
crater. 3. That the focus is of little depth, as 
there are no commotions nor subterranean noises^ 
and the stones diverge; for a cannon scatters 
grq)e-shot in proportion to its shortness. 4. Hiat 



i 1 la t F^trin, Mia. ▼. StS. 



IIOMAtN XII. TOLCAIliO* ^£5 

the electric fluid is a principal agent in Tolcanoes» 
because the eruptions are more frequent and vio- 
lent in winter, and in stormy weather. He, con- 
eludes that volcanoes, like springs, are emanations 
of fluids constantly reproduced. 

Ferrara has simply observed that Stromboli 
ejects in a year, what a volcano, subject to violtot 
eruptions, would explode in a day. He regards 
it merely as a volcano of an uncommon construc- 
tion. 

A volcano in the isle of Bourbon sometimes Ue of 
rivals Stromboli in singularity, a gtrht or sheaf 
arising, like what is called a Chinese tree in arti- 
ficial fireworks, and resembling tumultuous waves 
of fire, darted to the height of more than a hun- 
dred and twenty feet, and dashing against each 
other with a sanguine light, visible even at noon- 
day. The summit presents glassy drpsses ; and 
the crater is lined with fragments of greyish lava 
much scorified*. 

The history of submarine volcanoes might be 
illustrated by the details which we have concern- 
ing the new isles which have appeared near San« 
torin, in the Grecian archipelago. 

In his history of volcanoes. Ordinaire has given 
die following account of these phenomena. 

• B017, Voy. ISM, 3 vols. SfO. ii. fSl. 



584 BOMAW XII. VOLCAKIC 

Tbcnu « The islaad of Thera, afterwards St IrcnCt 
and now Santorin, was sumamed by the Grecians 
JLafAijfoti that is to say, burnt : and so in fact' the 
soil is, * There is a tradition/ says PUny, lib. 2. 
cap, 87, * that it rose out of the sea, at a very re- 
mote but unknown period/ This tradition is ren- 
dered probable, by the known events, which have 
since taken place near it. 

" This island with that of 'Miio, of whidi we 
have spoken, and that of Paros, so famous for its 
marble, forms a triangle, the sides of which are 
about fifteen leagues each. I suspect that there 
is a considerable central fire among them, of which 
the volcano of Milo might have formerly been an 
exhaling point above water ; though it is certainly 
at present unconnected with it> which appears 
from the effects of that volcano being in themselves 
slight, and from the situation of Milo being no- 
wise affected in the great commotions of Santorin. 
I found my suspicion of this central fire on a vast 
Bunt ides, number of small burnt islands, as they are called 
on the chart of that sea, which are scattered in the 
midst of the three principal islands, and pf which 
several had not appeared till within the eighteenth 
century. Almost all of them are near Milo, where 
there is less depth of water. I should imagine 
that these small islands are simply the productions 
of the central fire. The sea, on the contrary^ 19 



DOMAIN ZII. TOI»OA«IG* 525 

*rery deep towards Santorio, where it covers the 
mountaioi. whence proceed incessant eruptions. 
There is no ground for anchoring near -it^ as is 
mentioned by M. de Bomare, voL xv. page 128 
of his Dictionary. 

" Whatever on the surface of this sea-covered 
mountain be the quantity of matter which has 
issued from it, when the fires once set in motion 
in the void at its base within biecome active, they 
rise violently and carry the matter along with 
them, being always confined in their direction by 
the internal form of the mountain. Its summit 
then, and the parts round its summit, dre always 
the points most strongly attacked ; there it must 
and does in fact give way, as is the case with a 
volcano on land opening for the first time. And 
when eniptions take place in a submarine volcano, 
the masses already settled are always affected by 
them, and partly open, and their surfaces either 
g^ by the addition and adhesion of new ejections, 
or lose by some of their parts sinking into the fiery 
abyss, or into the sea. This is confirmed by all the 
eruptions, and particularly by the circumstances 
attending the last They are to be found in all 
the periodical writings of that time. An account 
,was published by Fatlier Gor^ who was an eye- 
witness of it ; and of his narrative I will give an 



526 j>oiuw xif. yohCAMie^ 

abstract, after I have taken notice of tfa& ei^it 
known eruptions which were prior to it ^ 

^^ They are all interesting to a laudable curiosi* 
ty, and proper to throw light on this operation of 
nature; but as the circumstances of this grand 
phenomenon are nearly always alike, I shall do 
little more than date the former eruptions, reserv* 
ing for the account of the last the most renmrkw- 
able particulars which generally attended the 
eruptions. 
Ofibm. « In the fourth year of the 135th Olympiad, 
that is to say, in the year 2S6 before Christ, the 
bland of Therasia rose in the midst of fire out of 
the sea : it is separated from Santorin by a strait 
of a mile and a half in breadth. * 

** A hundred and thirty years after, the island of 
Automate, which having heen consecrated to 
Vulcan, was afterwards more known by the name 
of Hiera, or the Consecrated, rose near it 

^' After another lapse of a hundred and ten 
years, in the like manner was formed a third 
island, called Thia, at two stadia, or two hundred 
and fifily paces, from Hiera. 

" These tliree eruptions are recorded by Plii^, 
in the place before cited ; by Strabo, lib. 1 ; and 
by Seneca, in his Naturales Quaestiones, lib* 6, 
cap. 81. 



JDOMADC ZII. TOLOAMIC. 527 

'^ In the year 7S€; the volcano^ after violent 
ejections of ashes and red-hot rocks, disgorged a 
great quantity of lava, which joined Thia to 
Hiera. 

^^ In 1457, this island was still farther in- 
creased, attended by the same circumstances. 
This event, and the date of it, are attested by an 
inscription on a marble stone erected near the gate 
of Fort Scarus, in Santorin. 

'^ A sixth eruption, in 1570, produced a new 
bland : it is called the Little Kamenoi. 

^^ In 1650, the a^tations of the volcano lasted 
almost a twelvemonth. Its greatest convulsions 
were at the beginning, from its opening on the 
S4th of Sq^tember to the 9th of October. The 
sea rose to the height of forty-five feet, and that to 
auch a distance, that some galleys of the Grand 
Seignor*s were wrecked in the port of Candia, 
thou^ it is more than eighty miles firom Santorin. 
Smyrna and Constantinople were incommoded 
virith the ashes which rushed out of the sea in 
whirlwinds of flame. All the particulars of this 
eruption are to be found in Kircher, a contempo- 
rary author, after the account of the preceding. 

^^ .This inexhaustible volcano i^ain opened in ^P^?* 
1707. « The Little Kamenoi was increased, and is 
QDw more than three leagues in circumference. 

<< Most of these eruptions, and all the circum* 



' 



52B nouAiK xtw rovcAmc, 

Stances attending the last mentioned, are reported 
in the third volume of the Memoirs of the Aca- 
demy of inscriptions, and in those of the Academy 
of Sciences, of the year 1 708.* 
direr. « The eruption of 1767 took place between the 
Little Kamenoi, and the island of Hiera. It 
began in the month of June. The earth, after 
being shaken violently for some days by the action 
of fire, raised the sea in such a manner as ta oc- 
casion a dread of its swallowing up all the islands 
thereabout. A thick black smoke darkened the 
air, and infected it with so strong a stench of sul- 
phur, that many persons and animals were suffo- 
cated by it Black ashes, resembling gunpowder^ 
fell all round. Torrents of flame, issuing from 
the sea, and waving on it to the height of several 
feet, lighted at intervals this horrible scene. The 
frightful mixture of different sounds, produced by 
all the elements in fury, froze every heart with a 
dread of the horrors which every instant might be 
the result of liieir conflict. 

"At length, after a labour often or twelve days, 
Nature paused, and the effect of her agitation was 
discovered in a new island, which had risen dear 
the Little Kamenoi. There was no time lost in 



* An ab»tnct of these remaikftble phenomena shall presently be 
flven.— ;P. 



DOMAIN XII. VOLCANIC. SS9 

going to examine it. Many parts of it i>rere st3l 
burning. It was a shapeless n^ass of baked sub- 
stances, amalgamated by a lava, vrhich, Father 
Gor6e says, appeared to the eye like the crumb of 
fine bread. But the very next day the inquirers 
were compelled to relinquish this hasty curiosity; 
and betake themselves to flight. They felt the 
new soil moving : it rose in some parts and sunk 
in others. The earth, sea, and sky, soon resumed 
their formidable appearance. The symptoms ap- 
peared even to spread wider and to threaten worte. 
The boiling sea several times changed colour : 
flames, following one another without intermission^ 
bsued as from a vast fiimace, but accompanied 
with ashes and pumice. The frightful noise of 
subterranean thunders was heard. It seemed as 
if enormous rocks, darting from the bottom of the 
abyss, beat against the vaults above it, and were 
alternately repelled and thrown up again : the re- 
petition of their blows was distinctly heard. Some 
of them, making or finding a passage, were seen 
flying up red-hot into the air, and again falling 
into the sea whence they had just been ejected. 
Masses were produced, held together for some 
^ days, and then disappeared. In this general dis^ 
order large portions of the Little Kamenoi were 
swallowed up. Meanwhile the labour of the vol- 
cano took a larger surface, its ejections became 

VOL. II. 2 M 



33Q POICAUI %iU 1M>4.CilflC« 

Ifff^igkwftly fkbun^Wt, wid a new isla^A wta Me9 
fimniog. By suf^esgive additioiis, contiiwed lor 
Bear four otKmtha, it made a junctioa with ^bit 
p(q4uc64 vx June, {t y^sfi nam^ the BUick 
Island, from tl^ pQlour oC Us s<«k. It is UMily 
twice as large as ^ iitlAa Knp^enoi, aad is aepi^ 
Vat^ ffoai it by ^ yery najnow atrvjt The Tol< 
eanOL ow^iMp d cr^atiqg ahuvx till tbie esd of May 
i^^^foU^wvagyeaf; frequently sh«ldng the earth 
sqA 9Ml 9a4 ^u^ing frightful noises. It eVeQ 
ogim^ f0M<^ ¥ytf ocdy for a moment, oo the 15th 
Qf ApsU, 9*4 Ihrew out a multitude of large bun:^ 
iffg ro$l^ i^hieh foil at th^ #»tan€e of two miles^ 

^ Iti i^ liherefore pn^i[^ hy ^me ^tiptions r^ 
qord^d in histoi;y, ^at there exists a maiitisptf 
fQ}caj«^ ajt $«ntorb* These eriqptioni^ have hapi^ 
fWenj^ in tih9^ fiwpe 9C ^w«ntyron.e centuries."* 

B^^ oi^ Qpt^ ^ruptioas of 1707, a npora oi^ 

m»^ ayd sajtisfo^ry a<:count had before i^peared 

|Q anotheir work. 

cmptioitt of '^ AcrQteri i(» aa island famous m natqial hia-i 

^|CH3r> and iS: s}|M»t^ ia. Htititde Sff north, long^ 



^u49S|$r«a^; i|6eei»s.t(>h«t<xwip99edof pumio^ 
^jQBe^ ^Qciwti^ with 4 aurfo^ of fertile earth, 
apA the ancients represent it as. rUmg^ m a. violeiit 
fankhcynJw^ ont qC th^ qe% Four Qthei: islwda 



• Oid.979» 



OOIIAIN KII* TOXi«AMIC« 551 

* 

had the same origki^ and jet the sea is here of 
Buch a depth as to be an&thomable by any sound«- 
ing^ine. These aHose at different times ; the first 
long before the commeiKtement of the Christian 
rara, another in the first century^ a third in the 
ei^^h, and a fourth in 1573. Another island 
arose in the year 1707 and 1708> between this 
island and Grreat Cammeni. The reader will not 
be displeased at seeing hefe a particular accouiyt 
of this extraordinary phenomenon. 

" On the 25d of May l707, after an earth* ^mtooB. 
quake thest happened the mght heto^Cj the last 
mentioned island was discovered early in the mom« 
ing by some seamen, who, taldng it for a wreck) 
rowed knmediately toward it '^ but finding rooks 
and earth instead of the remains of a ship, haisted 
back, and spread the news of what they had s6en 
in Santorini. How great soever the apj^reheti-" 
sioiis of the inhabitants were at the first sights 
their surprise soon abated; and in a few days, 
seeing no appearance of fire or smoke, some of 
fbem ventured to land on the new island. Theif 
Curiosity led them finom rock to rock, where they 
found a kind of white stone tilat cut like bread, 
which it nearly resembled in its form, cdour, and 
consistence. They alsd found many oysters stick-' 
ing to the rocks ; but while they were employed 
m gathering them, the island nK>9«d «fid s^ook 

8 M 8 



i 



55s DOMAIN UI« TOLCAMIC. 

under their feet, upon which they ran with pi^eci«- 
pitation to their boats. With these motions and 
tremblings the island increased, not only in height^ 
but in length and breadth ; yet sometimes while it 
was raised and extended on one side, it sunk and 
diminished on the other. Our author observed a 
rock to rise out of the sea, forty or fifty paces 
from the island, which, having continued four days, 
sunk, and appeared no more ; but several others 
appeared and disappeared alternately, till at last 
they remained fixed and unmoved. In the mean 
time the colour of the surrounding sea was 
changed: at first it was of a light green, then 
reddish, and afterwards of a pale yellow, accom- 
panied with a noisome stench, which spread itself 
over part of Santorini. 

^^ On the 16th of July the smoke first appeared, 
not indeed from the island, but from a ridge of 
black stones which suddenly rose about sixty paces 
from it, where the depth of the sea was tinfathom* 
able. Thus there were two separate islands, one 
called the White, and the other the Biack Island^ 
from their different appearances. This thick 
smoke was of a whitish colour, like that of a 
lime-kiln, and was carried by the wind to Santo- 
rini, where it penetrated the houses of the inha« 
bitants. 

'' In the night between the 19th and 20th of 



0OMAIM XII. VOLCANie. SSS 

July, flames began to issue with the smoke, to the 
great terror of the inhabitants of Santorini, espe* 
cially those of the castle of Scaro, who were not 
above a mile and a half distant from the burning 
island, which now increased very £Eist ; large rocks 
daily springing up, which sometimes added to its 
length, and sometimes to its breadth. The smoke 
also increased, and, there being no wind, it 
ascended so high as to be seen at Candia, and 
other distant islands. During the night it resem* 
.bled a column of fire, fifteen or twenty feet high; 
imd the sea was then covered withascurf or froth, 
in some places reddish, and in others yellowish, 
from which proceeded such a stench, that the in* 
habitants throughout the whole island of Santorini 
burnt perfumes in their houses, and made fires in 
the streets to prevent infection. This, indeed, did 
not last above a day or two ; for a strong gale of 
wind dispersed the froth, but drove the smoke 
upon the vineyards of Santorini, by which the 
grapes, in one night, were parched up and de- 
stroyed. This smoke also caused violent head- 
aches, attended with retchings. ^ 

^' On the 3 1st of July, the sea smoked and bub- 
bled in two different places near the island, where 
the water formed a perfeqt circle, and looked like 
oil when ready to boil. This continued above a 
month, during which many 6sh were found dead 



5S4 0OMAIir XII. TOtCAMIG. 

aa the sisore of Santorini. The following ni^t a 
dull hollow noise was heard^* like the distant re* 
port of several camion, which was instantly fol^ 
lowed by flames of fire shooting up to a great 
hei^t in the air, where they suddenly disappeared. 
The next day, the same hollow sound was several 
times heard, and succeeded by a blackish smcAe, 
which, notwithstanding a fresh gale Uew at tliat 
time, rose up in the form of a column to a prodi* 
gious hei^t, and would probably in the nigl^ have 
appeared as if on fire. 

^^ On the 7th of August the noise was different; 
]t resemUed that of large stones thrown all toge* 
ther into a deep well. This nois^ having lasted 
some days, was succeeded by another much louder, 
so nearly rosemhling thnnder as hardly to be dis- 
tinguished from three or four real claps that hqH« 
pened at the saaoie time* 

^^ On the SIst, the &re and smoke very consi* 
derably diminished; hut the next mormng they 
broke out with greater fiiry than before. The 
smoke was red, and very thick ; and the heat was 
so intense, that all round the island the sea smoked 
and bubbled in a surprising OMuiner. At night, 
our author viewing with a telescope a br^e fur- 
nace upon the highest part of the island, disco* 
vend sixty smaller c^ninga or funnels^ all emit- 
ting a vwy \m^ flun^; and be imagined tbent 



] 



JHl||4Ilt XII. fOl.C4aM» 5^j 

might be as iiiMily more on tiie otter side of tilt 
great voleimo. On the fiSd of August, in the 
morning, the island was much higher tfaaii the day 
befbrb, kad its breadth was increased by a thtain 
ef rocks sprang op in the nl^t ahnost fifty feet 
tf)OVe the water. The sea t^as also again covered 
iirlth reddish frothy which always af^peared when 
the island reeeited any considerable adfitionSi asNl 
occasioned a(i Intolerable stenth^ till it was dis^ 
persed by the wkid and the motion of tbt wares. 

'' On tiie 5th of SepiMiber, the fire Opened an* 
oAdr vent Hk the extreiitliy of the Black liland^ 
from yMth it issucfd for sefrerai days^ dbribg 
irhieh bot little was ^HsdMtfged from the larg« fttf^ 
nace : and from this n^ passage the astohisbed 
spectators b^ield the fire dart up three ^KS^hsnX 
timeik to a vast height, resembling so maify preidl^ 
^smt l^-rO«kets of a ^owhig lively rdd. Tlie 
MhHnng lii^t the suMdfaMoos flr^ ttaAC a «^ 
HMe ndbe, and immediatfeSy ctflMr a ftOiiMKId 
sheaves of fiiife lAew up info the lAr, #here, M(Hfti* 
ing and dispersing, they fell like a fjbbwat i4 iUn 
iipon the island, which appeared all in a blaze, 
pre s etf tift g to the amazed spectators at once li 
most di^ftdVhl and bea^ful iHMhination. To 
these natttrta} fireworks Succeeded a kind of meteor,- 
tirtiieh for sOkne time hong o^er Ite cairtle of SeaM^ 
^UcAf is seated on a hi^rddt in the ttfcmtef 



SS6 W)UAIV XII. VOLCANIC* 

Stotoiini, a meteor not unlike a fiery swoihI, aiid 
which served tx) increase the consternation of the 
inhabibiots. 

. ^^On the 9th of September, the fFhite and 
Biack Ishmds united, after which the western end 
of .the island daily increased. There were now 
only fbur openings that emitted flames, which 
issued forth with greiit impetuosity, sometimes at-* 
tended with noise like that of a large organ-pipe, 
and sometimes like the ho wUng of wild-beasts. On 
the 13th, the subterraneous noise became much 
fiugmented, having never been so frequent or so 
dre«^16il as on that and the following day. The 
bursts of this subterranean thunder, like a general 
discharge of the artUlery of an army, were re^ 
peated t^i or twelve times within twenty-four 
hours ; and immediately after each clap, the large 
furpace tljrew up huge red-hot stones, which fell 
into the sea at a great distance. These claps 
were aluirays followed by a thick smoke, which 
spread clouds of ashes over the sea, and the 
neighbouring islands. 

^^ On the 18th of September, an earthquake 
was felt at Santorini, but did no great damage, 
though it considerably enlarged the burning island^ 
and in. several new places gave vent to the fire and 
smoke.. Xbe claps were also more terrible thap 
iiver, aiKl in the midst of a thick smoke that ap- 



DOMi^lN Zll. VOLCANIC. ^^J 

peared like a mountain^ were seeo and heard large 
pieces of rock, thrown up with as much noise and 
force as balls from the mouth of a cannon, which 
afterward fell upon the island, or into the sea. 
One of the small neighbouring islands was se vend 
times covered with these fiery stones, which, being 
thinly crusted oyer with sulphur, gave a bri^t 
light, and continued burning till that was con-f 
3umed. 

. ^^ On the 21st, after a dreadful clap of subter- 
Taneous thunder, very great lightnings ensued, 
and at the same instant the new island was so 
violently shaken, that part of the great furnace 
came tumbling down, and huge burning rpcks 
were thrown to the distance of two miles and up* 
ward. This seemed to be the last effort of the 
volcano, and to have exhausted the combustible 
matter, as all was quiet for several days after. 
But on the 25th, the fire broke out again wilii 
^till greater fury, and among the claps was one. so 
terrible, that the churches of Santorini were soon 
filled with crowds of people, expectmg every mo- 
ment would be their last ; and the castle and town 
of Scaro suffered such a shock, that the doors and 
windows of the houses flew open. The volcano 
continued to rage during the remaining part of the 
year ; and in the month of January, 1 7Q8, the 



3sa 



large fatatitB^ irMiotit ode day'ft kiMTimsrioiiy 
threw out straes and iames et leMt c«lce or twtoe, 
but generally five or six tkaes^ ^ day. 

^^ On the 10th of February, id the oiomiiig, a 
pretty stroog eardtquake was felt at SantDtini, 
which the inhabitants considered as a prelude to 
greater commotions in the burning iriand; ncft 
were they deceived ; for soon after the fire • and 
smoke issued in prodigious quantities, tiie Clapd 
like thunder were redoubt, and nothing appear- 
ed but objects of horror and coilfu»)on ; itocks of 
an aaiazing size were raised op to a grent height 
above the water, and the sea raged and boiied to 
.such a degree that it- occasioned ^^eat constema-^ 
tion. The snbterraneotis bellowings were heard 
wilhimt intermission, and sometimes in less than a 
quarter of an hour there were six or seven erup^ 
tions from tiie large fiirnace. The noise of the 
repeated claps, the quantity of huge stones that 
flew about on everf side, the houses tottering to 
then- very foundations, and the fire, which now 
appeared in open day, surpassed all that had 
' hitherto happened, and formed a scene astonish- 
ing beyond description. 

•^ Thp 1 5th of April wa* rendered remarkable 
by tt^ number ^nd violence of the beHowings and 
ttuptions ; by one of which near a hundred larg^ 






SmUXH XXI. VOUUlliC. ^39 

itones were thrown up all together into the air, 
end fell again into the sea at about two miles 
distance. From this time to the 2Sd of May, 
wliidi might be called the anniversary of the birth 
of the new island, things continued much in the 
same state ; but afterward the fire and smoke by 
degrees subsided^ and the subterraneous thunders 
became less terrible. 

^^ On the 15th of July, 1709, our author, ac* 
companied by the Romish Bishqp of Santorini, 
and some other ecclesiastics, hired a bbat to take 

« 

a near Tiew of the island. They made dtirecdy 
toward it on that side where the sea did not bub- 
ble, but where it smoked very much. Being got 
into this vapour, they felt a close suffocating heat, 
and found the water very hot ; upon which tiiey 
direcied tbrar course toward a part of the island at 
^hj^^t»nc^^^]Mrff,fynim^ The 
fires, which still continued to bum, and the boil- 
k^ of die sea, obl^ed them to take a great cexn* 
pass, and yet they felt the air abont them very 
hot and sultry. Having ^compassed the island, 
and surveyed it caiefuliy from an adjacent one, 
Ihey judged it to be two hundred feet above the 
see, about a mfle broad, and five miles in circura* 
ference ; but not being tfacnron^y satisfied, they 
wsdbped to attempt to land, and aceordiD^y 



540 DOMAIir Xtl. VOXi(<U«tCU 

rowed toward that part of the idand where thej 
perceived neither fire nor smoke; bat when they 
got within a hundred yards of it, tiie great fiimace 
discharged itself with its usual fiiry, and the wind 
blew upon them a thick smoke and a shower of 
ai^eS) which obliged them to quit their desi^ 
Having retired a litde^ they let down a plummy 
with a line ninety-five fiithoms long, but it was 
too short to reach the bottom. On their return 
to Santorini) they observed that the heat of the 
water had melted most of the pitch from thdr 
boat, which was therefore grown very leaky. 

^^ From this time until the 15th of August, 
when our authw left Siwtorim, the fire, smoke, 
fmd noise, remained very moderate ; and by the 
accounts that he received firom that place for se^ 
veral years after> it appears that the island still in- 
crefised^ but that the fire and subterraneous noises 
wer$ much abated; and as the travellers who 
have ^ince visited the Levant give no account of 
its burning, it has doubtless long since ceased. 

'^ Strange as this account may appear, it is al- 
lowed to be qnquestiwably true ; and indeed, this 
is not the only instance, in modem times^ of 
islands risen fi*om the bottom of the sea; we have 
an account of one such in the Fhiiosophieai 
JVansactions, voL v* pagt 197, near the Azore$y 



DOITAIN 3C1I. rOLCkftUU ^41 

thus raised by subterraneous fires^ in the year 
1720. 

. " This happened in the beginning of December, 
1720. In the night, a violent earthquake was felt 
on the island of Tercera ; and the next morning 
the top of a new island appeared, which ejected a 
huge column of smoke. The pilot of a ship, who 
attempted to approach it, sounded on one side of 
the new formed island, with a line of sixty fathoms, 
but could find no bottom. On the opposite side, 
the sea was deeply tinged with various colours, 
white, blue, and green, and was very shallow. 
This island was larger on its first appearance than 
at some distance of time after ; and at length sunk 

« 

in such a manner as to be now only just above the 
level of the sea. 

** Upon this extraordinary production of nature, 
the narrator remarks as follows : 

^ What can be more surprising than to see fire 
not only break out of the bowels of the earth, but 
also to make itself a passage through the waters 
of the sea ! What can be more extraordinary, or 
foreign to our common notions of things, than to 
ake the bottom of the sea rise up into a mountain 
above the water, and become so firm an island as 
to be able to resist the violence of the greatest 
storms! I know that subterraneous fires, when 



54S MouAiM ail. rbtCAmtu 

pent in a narrow passage, are able to niat up a 
mass of earth as large as an island ; but that tiiis 
should be done in so regular and exact a manner, 
that the water of the tea should not be able to 
penetrate and extinguish these fired ; and after 
having been extinguished, that the mass oi earth 
should not fell down, or sink i^^ with its own 
Weight, but still remun in a manner suspended 
over the great arch bdow ! This is what to me 
seems more surprising than any thing that has 
been related oi Mount Etna, Vesuvius, or any 
other volcano.'* 
tJtoRba of Ordinaire estinialies the number of volcanoea on 
^ this globe, in actual activity, at one hundred and 

ei^(y-nine ; of wlucb ninety-nine are cm eooti^ 
nents, and ninety in islands. But if we reflect on 
the vast portions of the eartk which are still un- 
explored, particularly the intefkNr of Africa, and 
of Notasia, it will not be thought rash, if the whole 
be estimated at two hunched and fifty ; though in 
strict argument this number should be diminished, 
and not enlarged^ 
Ettmct Nor will the candid inquirer reject the suppo* 
^^''^^'''^'^ sitioa of a vast number of volcanoes odw extinct. 
Vesuvius itself haa repeatedly been in this aitoa*- 

• Bqpo't Geoip. Extncto, p. Mi« 



tion, as not ooly appear* fiiooei tba testimooy of 
,Strabo before adduc^ but from others. For 
Diodoru3 SiRul\Hhi ^^o flourisb^ at tbe be^nning 
of the reigp of Tibcdus^ «aya Vesuvius emitted 
fire in the time of Herculea; and he adds, that ia 
fact it retained many vestiges of conflagration*. 
Vitruvius had before* asserted that the eruptions of 
Vesuvius were mentioned in history, and that 
pumice, there founds also appeared near Etna^ 
and in those hilly parts of Mysia which the Greeks 
called the burnt countryf . Silius Italicus also 
expresses the same tradition. Nay, in latter 
times, Vesuvius became extinct from a. d. 1136 
till 1506, that is 370 years ; the crater being filled 
with coppice woods and pools of water, refuges 
of the most timid animals;]:. 

From the month of October 1702, till July 
1703, a series of earthquakes, like those of 1783^ 
desolated the southern parte of Italy. Among 
other phenomena, a volcano near Sigillo, in Fur- 
ther Abruzzo, which had been extinct beyond all 
history or tradition, suddenly opened the cover of 
its cratery and smoke and flames issued for three 
days, after which it has remained tranquil. The 
mouth of the abyss is only about twenty-two feet 

* Lib. y. 21. t Lib. iL 6. 

{ Acad. Nap. apud Ord. 937* 



544 



BOMAIN XII. VOLCAHIC. 



in diameter ; but no bottom can be found with a 
line of eighteen hundred feet*. 

It is now proper briefly to consider what are 
called Pseudo- Volcanoes ; objects only important 
in the systems of a few mineralogists. 



^ Mem. Acad, des Sc. 



APPENDAGE TO THE VOICANIC. 



FUMAVOLS, 

t. 

OR 

PSEUDO-VOLCANOES. 



;' '. 



VOL. II. 2 N 



a 



I 



#47 



FUMAVOLS. 



JL HESE trifling ignitions of coal-pits are treats 
tA by the Wernerians with an importance truly 
ludicrous. Their chief products seem to be in- ^vm^^ 
durated clay, and, according to some, tnpoli. 
Slates may also be turned to slags; and what is 
called porcelain jasper, probably an iron stone 
affected by the heat, also appears in the ricinity 
of those ignited spots, particularly near Dysert Dymu 
ih Fifeshire, where a coat-mine has continued in 
a state of deflagration, at least since the time of 
Buchanan, 1560 ; for he minutely describes the 
spot in one of his poems. Nay, according to 
Mf. Kirwan, who quotes the Memoirs of the 
Academy of Sciences for 17819 the mountain of 
Cransac has continued burning since the year crmac 
1400. 

It is observable, that Mr. Kirwan^ and the 
other Neptunians, regard columnar argillaceous 
iron ore, which has a singular affinity with pris- 
matic basaltin, as a product of these pseudo-vol- 
canoes, a name which would more properly be- 
^ 2n 2 ' 



5i% 



APPENDAGE TO TK£ VOLCANIC. 



Name. 



Mpnuod^ 
account. 



long to mountains which, like that of Chimera, 
now called Goranto in Natolia, emit flame and 
smoke, without any other ejection ; than to lit- 
tle ignited spots, which, like one of the Italian 
isles, might be called volcanellos. But a more 
proper name for these ignited hills and spots 
would hefumarols, already admitted into French 
from the Italian, as their chief mark is their 
smoking in rainy weather. Yet zsfumarol has 
been used in a very confined acceptation, some 
may prefer fumavols, from their smoke, and di^ 
minutive resemblance of a volcano. 

Among other causes of these ignitions may be 
mentioned saline ballast and rubbish of ships, 
which have formed a fumayol not a little destruc- 
tive, near Sunderland in the north of England, 
Pallas mentions a mountain in Siberia which 
continued to burn for a long period, the ori- 
ginal cause being a pine struck with lightning, 
which communicated the flame to the rest of the 
forest, and to the surface of the ground. 

M. Morand, in a curious memoir on the spon* 
taneous inflammation of coal-mines, has describ- 
ed the singular fumavols or pseudo-volcanoes of 
Rovergue, a district of the former Guienne, ly* 
ing on the south of Auvergne*. The mountain 

• Mem. de V ac. des So. 1781, p. 1 69. The style is embarrassed 
and olxcure. 



PUHAV0L9. 549 

of Cratisac is mentioned in charters, as btirhing 
•in the year 1400 3 and has been noted in several 
works of geography. The smoke may ^ome* 
times be seen at the distance of a league; and at 
night> especially during rain or snow^ the flame 
appears red, yellow, or blue, 

- M. Morand has given a curious list of the sub* / 
stances affected by fire, being chiefly indurated 
telay, or porcelain jasper; slate of a brick red, 
often with impressions of vegetables as usualin 
coal-mines; dross from oxyds of iron ; the dead 
rock of the Germans, or red sand-stone; slate • 
redoced to impalpable powder; a kind of tufo 
composed of powder and sand ; besides sulphur^ 
alam, and ammoniac. 

. His account of the hill of Fontaynes, where 
the coal-mines took fire about the year 1763, is 
curious, and may give tlfe reader a complete 
idea of a fumavol or volcanello in its greatest ac« 
tivitv. 
" The hill of Fontaynes, situated near Ca- Hfli ofFon-- 

taynes* 

huac, is surmounted by two adjacent houses, 
forming the hamlet of Fontaynes, in the parish of 
Aibiu; the lower house belongs to Aluratels, 
and the upper to a person named Capellcj pro* 
prietor of the mountain. The fire having de- 
stroyed bis plantation of cbesuuts; and his coaU 
mine, which was of the first quality; now threat- 



550 AmifOAOB TO Vm TOL^AVIC. 

eni h\$ housed ; and occ«pies a surfiice ^ eiurtb 
with a 9lope towards the north or norib^ivert ; itf 
etiimt may bo in lengtb from oast to woat» 
about ^ fatboms, and in braadtb* from iK>rtb t^ 
0oath> 56 fathoms* 
ApiKMrnce. M All the surface on the nde towards Fon^ 
^ taynes» Tarionsly coloti^ed, but more particu* 
lariy with red» visibly bumtt no longer regularly 
following the slope of the mountain* is entirely 
broken* deranged, furrowed in clefts, in crerioes^ 
in trenches or a kind of small ravines, which an« 
nounce an interior and pretty deep convuIsi<m; 
and, by its appearance, it might be suppoead to 
have been lately shaken and overturned. In 
some places it is hollowed into pits, in irfhers it 
is lifted up in small eminences or little hills, 
^rmed, some of masses of large cinders, and of 
ashes, the remains of substaooes which hem 
escaped calctnalion : others of stones, sometimei 
in large detached pieces. The variegated co« 

* ^' The aooidcBt aboui to be described is bat of late ori^, 1% 
dates from the grant of 1763^ before which the grantees, whoal 
Sudalia and Bouqui^ only worked small coal for the forges, caused 
ail ^e proprietor's mines to be shut op, and woold only allow the ib* 
habitants of the country, to foniish tbemseWes with what ooal ihfy 
wanted from the mine of Fontaynet. It is said, that the considerable 
number of purchasers not allowing time to raise the small ooal, the 
inhabitants taking none but the large blocks for their use, the small 
ooal fomented and took Src." 



ioun ot fthfiM fr^gmemta belosg to tiiMe mbkk 
«r» imown to be the r^nflt of eaJrination^ move 
or less ^liiig on 6ftrth8 aad irgiIlaoeoo9 or 
^diktose Mcks, otpeeiallif of a ftrragtiioiis |mu> 
tore. ThU dry and dwor^ered mfface pimcpti^ 
IpwiieoUriy towards tiie oasteni side, agaiost 
which (lie niioka it oftoMst driveii^ the most no- 
equivocal characters of the completost stertlitjrj 
no kind of idattt bting to be Ibuad th^fo, not 
I^K loMt ¥6rd«re. 

^ OMrered (weiw ymm ago, as weU as att the D^mMt. 
Aoighbottriog qaarter, with fltiagiiificeiit chesmit 
walks of the first quality, a second resouree lor 
^o CQWitry after coal, there maains no loiiget 
any traee of these trees, except on the lower 
Imfders of the mountoin, even in the part which 
(s iniamed ; where is perceived, nearly opposite 
Capelle^s house, a single stump, stSU aiihering to 
a portion of the trunk above ground. This stump 
and the trunk, hollowed and nuned by the si4>* 
terranean heat, are, actually, only a mishapen 
qsass, which, seen from the house^ is distin- 
guished by its eoal-Uack colour, and the smoke 
which issues from it, as from a vent spouting; 
irom the earth. 

'^ From all points of the surface of this moan- 
tain, even from those where neither crevice nor 
dislocation is perceived, through ashes, 4Ntnlii, 



559i APP&VOAOB TO TH8 VOLCANIC. 



stonesy which seem lifted up» guits of smoke 
more or less dense escape, as from under the ex* 
tingnished and smoking remains of a great con* 
Aa^ration* This mioke, according to the wind» 
disperses by spreading itself over all the snrfiice» 
or, in calm weather^ rises in clouds more than 
100 feet high, and is then sometimes seen at a 
^reat dktancd. 

^^ A just idea may be formed of the burning 
mass, and of the degree of heat of the burning 
mine of Fontay nes, at the time that I was there» 
by the foUov^ibg observation. I was travelling 
towards Albin, coming from Villeneuve^la- 
'Cumriftde^ on my arrival at Montmajet^ three 
hours from Fontaynes, I . had observed this 
,smobe ; and my guide, from the place we had 
just left» tellii^ me he was no longer certain of 
the way, I perceived it, and he sought it; I 
made him observe the smoke of the hill of Fon- 
taynes,^ where he h|ad' never been, and with 
)Which hi» was not.iri the least acquainted. 
Vapour. * ^' 'In short, another circumstance sensibly 
.strikes the throat, the smelling, and the eyes^ 
it is the moist and earthy vapour at times sensi- 
bly sulphureous, at some places even suffocat- 
mgy the dtsagreeableness of which is sometimes 
.perceived, even on approaching the vicinity of 
Fon^yrnes. 



I 



VUMATOLS. 553 

^< In order to AimiBb mjrself with an exact and 
complete' picture of all the parts of this pheno* 
m^ion^ which bad drawn nke thither, the cir- 
cumstances I have just relMed were, the only 
<mes, to which I confined ikiy first inspection. For 
that pufpo8e> I remained for some time at the 
place wheire I arrived coming from Albin; it 
was directly on the crest of th^ mouotaiUj above 
its inflamed part, bordering even on the brink of 
the soil where its degradation is at present mark* 
ed. What there most astonished me was, three 
kinds of Inminoius globes (I describe them as rm. 
they appeared to me), at different distances fir(mi 
one another^ in the lower part of the mountain^ 
nearly of the same size as the moon appears 
when at the full, of a bright red, or such as the 
fire in a forge appears, at the farther end of a 
smithy when seen from a clear and distant place, 
. ^* I did not know what it was; I nevertheless 
attentively observed these brill iant points, which 
I was desired to consider. Do you see the fire? 
said they. The stones, or any thing found at 
hand, which my guide, and those who were with 
us at the time, amused themselves with throwing 
towards the place where I perceived these bodies 
of light, explained to me, what I had neither 
been able to judge of nor define: they were so 
many apertures, which served as chimneys to the 



^4 APPBNDAOB TO TB» TOLCAlTZe. 

quiet pMsage of a bright and livdy flame, shel- 
tered frons the wiod. The edges, or ex4|piior 
coat of these fuiiiids, reddened by the fire, se aa 
to be blended in colour with the flame, to whioh 
they senred as conduits, and which was not at 
firat perceptible, produced that effect of light of 
which I have endeavoured to describe the fifst 
appeantnce. When the stones or wood whioh 
had been thrown towards these bumiiig mevths^ 
reached them, then their coats, breaking aad 
felling into the flame, agitated the ftre, causiag 
efections of a reddish hue, to a height and of a 
?<rfume proportioned to the derangement eaiised 
in the furnace ; cKactly as it occurs, on a small 
scale, in the lamace of a blacksmith, when he 
stirs the fire. 

'^ If the pieces of the trunks of trees, fibrowa 
on these funnels, were not carried into the fire, 
with the crust of the apertures, they would in- 
fltantly be seen to take fire, or be immediately 
reduced to charcoal, 

** In other places, towards the top of the htt 
where I stood, and more within my view, the fire 
likewise appeared in all its force, but under a dif* 
ferent aspect, and otherwise varied and repeated. 

** Generally the trace is distinguished by a 
light, accompanied by a flame, fluttering from 
time to time on the surface, from a prodigious 



nimiber of littk crevices, ntber indented, whick Cimem. 
msU^df in a serpentine direction, to a greater or 
Jets difitanoe. Theie Jittla crerices are theaoeelvM 
dialiagaiflhed by a constant trembling, perceptt- 
Ue on tbeir edges; the playing of the flame, • 
joined to the continual derangement of the edges 
of the crevices, which fidls in a fine powder ia 
the interior of the QltAs, giving them a partic«^ 
iar motion, which cannot be better compared 
than to a kind of twinkling, 

^ In other parts the fire, confined in a kind of 
epen ravines which are very numerons, struggles 
against the wind, when it blows in the direc«> 
tioa of those trenches i and forms, to the sight, 
a Kdi stream ef flame. 

^ By sounding the earth with . my cane, to 
airoid those places which wem too hot, and re* 
guiating my rteps by the wind, so that the smoke 
and mffocating exhalations of hot, humid, and 
sulphureous vaponrs^ were driven before OM, I 
had the satisfaction of approaching pnd examin- 
ing at my ease, ampng others, a very large ore* 
vice, which, at that time, happened to be burn* 
ing ; its winding, broad, and elongated mouth, 
was as if enamelled on its exterior edg^s^ by vola- 
til isatioM of different colours, aedoftbegfentest 
delicacy, which from time totimefell into thefire. 

*' On the kind of ashes which formed the soil 



5S6 APPBNDA6S TO THB VOLCANIC* 

/ 

zdjoiniiig this ravine of fire, seme substances 
'Collected in tolerably large heaps, boiled up,«hav« 
ing the appearance of a brilliant metallisation, 
coloured like that kind of copper called rosette. 
However difficult the access to those places 
-where I remarked these frothy scorifications, I 
contrived, with my cane, to get by a little at a 
time, from the hottest parts^ some fine pieces, 
to bring them within reach, and to take them 
away when perfectly cooled. 

•* The direction of the wihd^ then correspond- 
ing with the aperture of this magnificent preci- 
pice, was very* fiivourable to enable the eye to 
examine the extent of the gulf. The external 
air, agitated by the wind, penetrated into it, su- 
perficially acting on the flame, and by directing 
It like a wave, to the other extremity of the burn- 
ing ravine, where it became turbulent, and roar* 
ingi even in the interior*, afforded the facility of 
observing a deep and void space, a superb fire, 
gentle and quiet in one part, undulating in an- 
other, presenting only a bright red, such as is 
perceivable in a glass-house. 

^^ The idea which suggested itself at the sight 

• *' Which brought to my recollection, what is said by the inha- 
bitants in the neighbourhood of the plain of Dyiert Moor, in Soot* 
land ; they pretend that, at certain times^ they hear marmurinsi 
and whistlings in the holes and caverns. Art (^exploiter Us Bones 
de charbon, p* 36." 



FVKAVOLS. 



567- 



of this object^ of diversifying it, of changing the 
actian of the fire, by throwing different things 
into the precipice, which sometimes seemed lost 
in an instant, afforded a kind of amusement, not 
unworthy a naturalist Stones thrown bound- 
ing into this furnace, produced flaming eruptions 
with sparkling, even with a detonation, and ere- 
ated as it were little tempests, which gave a 
kind of diversion, which might be renewed as 
often as the shock repeated in the chambers of 
fire had neither destroyed nor overwhelmed them.. 
If it was .possible to approach these furnaces with 
safety, and without danger throw in large masses 
pf any substance whatever, so as suddenly to 
compress the fire within, there is no doubt, but 
one would see a real brisk explosion*. 

^' The singularity of the sight, of which I 
have endeavoured to give a sketch, would com- 
pletely satisfy the most indifferent traveller; it 

m 

• "That related by M. labW Marie, probably had no other cause 
than the detachment of a considerable part of the earth within. M. 
Laurens, curate of Albin, informed me, that in September last, this 
mountaiii in the night had made a considerable explosion. The 
noise which accompanied it, was like that of a cannon, the ground 
of the vicinity, to a considerable distance, was next rooming found 
covered with stones thrown up by this eruption ; the quantity was 
observed, and was estimated at 200 cart loads. The surface of the 
hill also showed by its alteration, the conflict within ; all which was 
caused by a current of water, which had been injudiciously intro« 
ducedj with a view to extinguish the burning of the mountain." 



5S9 AYPBKDA6E T0 VKB TOLCAVIC. 

w«i nelr to ftitf^ and excited my ouriofity mi aD 
pohiti. It may wdl be Mpposed, thMt I did itofc 
<$onfitM njself to lhi» idle iofpectien; ia Umet9^ 
itg wkh an mnc^rtain step thia smcrkiog and 
btinM|^ Mirfacd, which often obliged me to tnrit 
froitt one part to another; in walking oti thia 
demoHlion of sobrtances^ to admire^ mb near at 
pofltiUe, the different apertures of fire, which i 
was accnstonicd to distingoi»h ; I felly perceived 
flnt those oonfnsed remains^ deserved a separate 
and detailed examination : their different tints of 
wbite^ yellow, yellowish, violet, greenish, of 
#tfarr cdoQfs that they have acquired according 
to their natore, according to the duration ord^ 
gwe of the fire, made them already remarkable^ 
PkMtaca. *^ They are all either calcareous, of vitrifiaUes 
tlie greater part resemble baked bricks, some Are 

m 

vrbitoned, calcined, reducod to lime, and art 
changed into a kind of red pnmice, or bear otiier 
marks of scorification in different degrees, some- 
times with mixtures of stones more or less altered, 
at veined tofos, formed of ashes, and lapUld 
agglutinated together. Several of these sf ott«!t, 
and in great numbers, are visibly and abundantly, 
either impregnated, or incrusted with salts and 
Mlphnrs. Mere stones of different siilses, covet 
thick beds of ashes, reduced by the strength and 
duration of the fire, to an impalpable powder^ 



Still bttmiiif in certain ^aqeifw These ashes^ if 
they may be called so, heaped soiMtifiies in 
making h^Uowsi form very dangermid spots j a 
stifck may be thrust into them with the f reattsl 
•ade ; in going oter themj one may sink to one's 
ktiees : I myself founds that^ besides the great 
heat which is ooncetitrated in tkem# it was no 
little trouble to get out of tbemi 

^' The liveliness with which the fire sboWs it^ 
telf^ towards the eatft aaid the south of the hill, 
whefe the trees Uplit at 30 fathoms' difitance, does 
not jtermit much detailed observation^ otherwise 
than as fdatis, either to the &ety spectacle of a 
cowiderabkf surface of earthy or to the aspect ctf 
a €0«fuled aAd extraordinary subvefsiM« One 
eaiMMt lipproacb every spot one would wish. la 
some, at the bottom of the burning part, the heat 
is sufferabte } the neighbouring inhabitants roast 
their eherinats in it; even rabbits like to burrow 
in it, and, althoagh the Beaton when I wae there 
was extrenAely hot, I have seen tome of those 
animals driven froth places contiguous to thtf 
burning soil. On approaching the centre of the 
mountain, the superficial heat becomes stronger ; 
besides, this burning and moving earth, in some 
places, will not allow you to remain any time ; ^ 

either the stones give way under the feet, and 
are buried in the ashes which they cover; or the 



S6Q . APPBNDA6B TO THB VOLCANIC* 

beat which is felt through the boots^ becomes in- 
supportable. 

*^ One is then obliged every moment to move 
forward or return against one's will^ from the 
way one would wish to go. If the naturalist 
would observe these objects near and in their 
place, he is not always at liberty to satisfy him- 
self, the suffocating smoke sometimes preventing 
him from stooping as much as would be neces- 
sary. The day I was at Fontaynes> the wind 
was favourable, as I have said ; it prevented the 
smoke from rising, and, at the same time, drove 
it in a certain direction. . But it often happens 
tiiat the heat of the fire will not allow the tra- 
rdler with impunity to pick up calcined stones, 
or other substances, which he may think worth 
examination. 

^' This burning heat of the hill of Fontaynes, 
seems to gain towards the east and south ; on the 
opposite side where the fire recedes, grass g^ows; 
and corn and rye are sown within four or five 
fathoms of the conflagration." 



SUPPLEMENT, 



VEINSTONES. 



VOL. II. % O 



• * 



VEINSTONES. 



X HES£ stones have, in cabinets, been often 
confounded with rocks, from which they should in 
general be carefully distinguished. They are call- ^^n^ 
ed veinstones, because they are found in the teins^ 
either metallic or barren, which traverse many 
mountains. 

'Che reader who desires complete information 
concerning those veins, one of the most important 
topics in tiie science, is referred to the elaborate 
work of Wemei*. A few general ideas w91 be 
sufficient for tiie present design. 

Most mountains consist of stratified rocks, by 
the Germans called ^i^;af^ ; and the beds are 
often intersected, almost at right angles, by "vdiat 
are called vdns, of more or less length, depth, and 
thickness ; sometimes metallic, and sometimes of 
it rocky substance ; but dissimilar from other parte 
of the mountain* Oppd^ formerly president of 

* Ncmrdle Tbeorie de U fainsdoa An (Boas. TMntefv 
| >l ri bstiiol L IWHUOCttfQ^ 

S08 



5 54 tUPPLIMBNT. * 

the Council of Mines in Saxony, has informed lu 
that the mere fissures of rocks are commonly very 
narrow ; while a vein, on tlie contrary, may be of 
prodigious extent, and is always filled with a sub- 
stance difierent firom* that of the mountain. He 
was the first, according to 'Werner, who establkh- 
ed the essential difierence between veins and 
Jkstxe^ or beds, which may be metallic and con- 
tain a heterog^ous substance, yet must not be 
called veins, as they follow the direction of the 
other strata. 
Aireen. Many primitive niountains consist of what have 
been called, with great impropriety, vertical strata 
or beds ; while the latter words of themselves im- 
ply a horizontal position. The terms arrects or 
uprights have, been here proposed and adopted, 
in order to obviate a solecism long regretted by 
writers on mineralogy. Such mountains consist* 
ing of arrects, are often intersected by veins, which 
cut these arrects in an opposite direction. 

OrigiB. It seems a probable opinicm that many veips of 
great extent may have been produced by the de- 
siccation of the globe, after the retreat of the 
primeval waters; while- others, may be owing to 
the subsidence of parts of mountains resting on 

EsiMt an irregular nucleus. At Uspallata, in the Andes 
of Chil^< tl)ere is a vem of silver, which has been 
traced to the enormous lenf^ of 90 mileS'; bat'iiy 



many has been suppose^ to extend to Potosi, that;ifli 
840 geographical miles. The grand vein is alwaya* 
nine feet in thickness ; but on both sides numeroas 
veins branch off, which may be said to penetrate, 
in all directions a chain of mountains SO miles in 
breadth** From this surprising example, an idea 
may be fimned of the extent, of some veins, which 
have continued to be richly productive after the 
labours of many centuries. 

In conducting their subterranean operations, 
the miners use a kind of compass, divided, in to 

w 

twice twelve hours ; 13 and IS being k. and s. 
while 6 and 6 are £• and w.f Thb is used to 
estimate the directian of the vein ; while its tncli- 
Mff/JM is' measured by the plummet The dip is 
often .confounded with the inclination, but seema 
more properly to imply the general decUnation^ 
taken in the line or direction of the vein, lhan:tfaa 
lateral inclination or obliquity. Thus if a book 
be held obliquely, the. back will show the direc>* 
tion Qf the vein, which is seldom strictiy horizontal^ 
but dips at one extremity, while at the othw it is 
salient; or» in the lai^age of miners, bassets out^ 
w rises to the day. The width of the back shows 



I«L Nat del ChiU- 

f InreDtad by the Gennant, ifae lalhen of modem minenlogf • 
The dihcr minei in die Huts wcve d iioofe i e d a* 9, fifiS* Thorn 
«f Sttopjt by « Hitta aviMrt tboil A. P» 1X90. 



A66 



^9WnMMMMT* 



Hbe tliickiiess of the vein ; wiule ibe sides Husk 
the declination from the vertical through the 90 
^d^rees to the hoiiaoii. But a little sketch and 
explanatioii, ^ven in the appendix, will explaio 
this subject better than any verbal description. 

The rock which covers the vein^ is called tiie 
roof; and tiie bottom is called the sole. Tbef 
are also called the hanger and tfie ledger^ Tke 
English miners also use the word kade^'to denote 
the mcKnation : and rake vein, to denote the per- 
pendicular, while the pa^ om approaches tfaa ho* 
TizootaL The veinstones are s(Mnetinm caUsd 
riders: and the German word /pcA is retained ftr 
a cavity or empty qmce« 

sdtandi. The vein raxdy coalesces with te rack, bnt is 
separated finom it on both sides by wiMt aie catted 
the salhrndsy which, lil;e walls^ oontain the mnwh 
lal: and often by the skkis^ in Geronoi betttg, 
wUcfa are small layers of earthy matter, oomsmdy 
arpDaoeoos, lying betnaen tiie saUiantb and the 
raek In the veins themselves tim ores are ne« 
empankd with lliear gangartioi qnarta, haeytai^ 

Ctvitick oakareona spar, &;c»* There are alsn ccmMBr, 
whicb m powerftil veins are of pnportiottBi en* 
tent, so as to appear like chambers, stndded all 
over with druses^ or giroups of beautifiil ores aod 



eryfitalfl^ whichy when enli^itened by tordies, ex* 
eeed all Hm ideas of orieDtBl magmficenoeiy and 
aeem the chosen abodes of the ftdries of the nooe ; 
ft race whose existence was anciently credited in 
all mineral coontries. 

These cavities are often found where the vein is 
mast powerful^ and the sides are covered wilii de^ 
iMMitions of Tarioas periods, whence Werner ad* 
duces them in supportof his tioteory, that the veins 
fvemoqee empty, and wwe fiUed iroin above; 
eapedally as -the crystals are covered on that side 
wiili little <iryata]s oi pyrites, magnetic iron, and 
ipltea^ which, by his doctrine, may have distiUed 
^Eom above. This is opposed by the theory of 
Tnefara^ who fiir thirty years soperiodsnded the Tfeimteideiu 
sansa of the Harts, and who afihns dmt ^letallie 
aeios are istmed by tiie fimnentation and.exBlt»> 
tion Off irapaiifs, wfaidi we now call j;aies; and 
whieh ofierate as it were a kind of life in the iDte^ 
rior of the earth, perpetually deconiposii^ and 
ta insuwi ting asiaeiai an b ata n ces*, Hewoukipar- 
hapa base infcrwd. that, thougfai the gases rose 
.fism benefrih, tfa^ were oongealed^ as in distilr* 
Itvy^ hf tltt eopcrior coU, and tlien let fall their 
depoiibbns. Vain sometimaa erosa each other in 
dtffaent dvecthins ; and it seeni^ dear that those 



* See his corioiu work on the Interior of Mountains, a .foUo 
TOdmt tf anri atefl hito Fiouish, bjrDistiidtf 



568 

which extend across the others iiu»t* be the 
Aodeataiid tDodem; the andent having been broken by tt 
later subsidence of the mountain. \Temer m-* 
forms us, that in the mining dbtrict of F re y be rg 
there are two kinds of veins,. of very difiereat de«* 
scriptions. One kind consbts of those wfaidi ktc 
called northern and southern, that is, they rum 
from nine to three hours, according to the minera* 
ocHopass, or between the nortiii^west and Ibe north- 
east They yidd galena, black blende, pyrites^ 
either coppery, arseaicai, or caaaagmi\.qamtm, 
and brown spar. The second kind of vdns; 
always traversing the first,. and never travecaed hf 
them, contains galena with a little radiated ^lytitoi^ 
barytes, fluor, and qiuurtz. This.ektends betinct 
the sixth and ninth hour. One district oootaMi 
veins of tin and of silver, the former bdng always 
traversed^y the latter. The dhrectioa ;of the fini 
IS chiefly between six tad nine hours^ while that of 
the last is between nine and tiiree. 

In a more immediate consaderataoa of the vena 
themselves, it may be observed that Aey hane 
sometimes neither skirts nor salbaods,. but pass 
into the rock itself, which in that case is- oSbm 
somewhat decomposed. Weraer .jsaya, that <Ui 
particularly happens when: yein^ toiaded. wilh 
quartz and hornblende, occur in. a quartzy gpif^ ; 
and sometimes only in particular parts^ while Out 



otibers are divided from the rock by the sattmnd, 
-or by te bcsteg of clay. The ore passbg into 
the .duote of the rock, sometiiiies for a fisw inches^ 
jiewr more than a yaid^ is always in a leafyor 
•rapcrficial form. In diffincnt minii^ distdets of 
CrernMOiy, aeveral sflver ores are wrouglit in the 
itocomposed gneiss of the roek adjacent to the 
aalbeads of the mine; iaad^at Xqng^berg in Nw'- 
.way, natiFe silfm* appeals in gneiss, mica-slate, 
jmd homhtaide. . Copper, - galena, and even tii% 
jemetim es assmne the same appearance. : > 

f jSdmetimes fragments of .^ rock have dropped 
into the vn. And been enveloped: in its subftCance. 
fiat Werner seeins to ishide a great dificttlty; the 
■hailisr appearsiiee of masses of nmiersl, by iM 
finmcfa called jdocAor or pockets^ which have been 
aindflntafly diAsovered at' detached andivMe inf^ 
.tarvals, ia^ievolid body oftfaer6ck; • 

It nraat net -be ednoervdd tfiat all veins are me* stoMfvia. 
taBiferous.> Bdhny; on the contrary, disappomt * 
Abe hopes of 'the miner, and ai^ffound to consiA 
esticdy of stona Weh«»* tnentiox^nrdiis of gra-^ 
liil^ ^perphyry i IhnesMie, < basalt^ ' wadcen, tiokl 
grimstein; Haeids, tbat4n dome parts of Saxfony 
Mins aire foubd dfathalt^grwiM gramfe, ioi^ a rock 
of^miBaHdate^'iand'tiiese i^ritti^ are ^tmv«Med and 
demnqpdi by/vems of sttrer; vrtnch ptoves^that the 
ghmilicveiasianmoreiadoim In other dinrictf 



570 



appear vems of porphyry and of trap^ or baMdlBt. 
Veins of wackea aie particalarly ftequent in tbe 
iBBtaUic mounttiiia of Suony ; they ti av eni e aU 
tiie otiier metatikr veins, and' are of ooorse of m 
more modeni fonaataxi. Veais of grunstieiB ap^ 
pear near Bautzen* In the aooinfeaiai of Schna^ 
berg and Hartensfedn, dKre are veins of cbyrdals^ 
In ^e Pyrenees/ Dohaasel ohserred^ nat fir fron 
veinsof te peakofOncet^ what ha calls «.hed of grants^ 
aiK)ut nme inchai lldck. cndosed befameii two bads 



of trap, whidi ware thn aaschfm farinaRd bfjtwaaa 
two beds of IhiMBtaae. ^ We ofaaennBd tfaatthe 
infimor bed of trap di sa p p eartdy tenninaiiag in 
the £mn of a wedge^ ao that Urn gcanitai aftsn- 
wards reposed on tiie Imiestoner We abb afc» 
served that the ktker ia oftea penetmled by tfascads 
of grsiitewhitib appear on lis anrfioe, ia db^aq^^ 
zag form; and the granite alBO aasmteathelbmi 
of nodtdes, being ia dl these dscninifeanoea tndj 
p&eieiit to the rock, which si]qiports or cndoaes 
It, forming with it a eontnuMMis bddy$ and dKoa 
is>«7ery teaaon t6 bdieFs that it netei 
tomuoh^dfif^tb. This gpraatte is in a gnat 
9a«|>06dd of irfal^.of fetsp^r^ aaon orlesa 
gledrwildler^stak^MbokseholL aOttaan 
lb« qmrfes ane thinly scaltarad; :Tim teaas dni# 
triet^ ofiersd aaoliieir pheabaienon t wn! pooased 
maj teal veina of waam^ dbmt^n, nek ai 



«7I 



^ttkkneas, trafemng dkmetricaliy the maas of the 

•It appears^ firom the ooadoaioD, that the Pic do * 
Midiy the chief oft^ject of these observatioQSy iseok 
tirely oompoaed o£ primitive rods, in diatbct and 
continued bedi^ or properly anects^ inclined from 
60 to 80^; the anperior beds, httmediately covers 
iag the limestaine^ heing ^a^eiss and gamet^rock i 
•boive which are numerous alternating beds or 
arrects of Kmealoiie, trap, and sianetimefl of gta* 
nte. The disposition of the trap is remarkable, 
as it often afiects, between two letel beds of lime* 
itamey folds either sii^ or mul^lieci^ and of the 
stmngest appearance. The granite of die supe» 
rior beds or arrects presents many features,, as m 
Tsittf as a bed^ and as a constitQent part of many 
ealeaieoua rocks ; bu^intfaelatlercaae, itisonly 
ibesid on lim anrfiboe, as if it had been depositBd 
noD aifter the compaclioQ of the catcareooa mol»» 
emes« 

Vems of granite^ composed of qtmrtK^ folspar^ 
and white mioi, haive also been ofaserved bj Bea« 
aai^ in the lioaosin, in a day slater Thsy are oa 
nplaiBiwfaidihaabeantiUfid; and he obaened na 
gianitJB rook in die ne^^tboorhood* Thai gnmila 
is isi wy kige a*d irr^ular ptmni -m carei 



stance also remarked by Dolomieu, who says that 
^uch granites differ from those of the mountains, 
* as the grains are larger, the substances less inter- 
woven and coherent, while each has a greater ten- 
dency to regular crystallisation. But, on the 
other hand, Charpentier observed, in various parts 

^ of Saxony, veins of granite in mountains of gneiss ; 

the granite consisting of white quartz in vary small 
grains, mica in fine particles, while the felspar was 
scarcely distinguishable from the quartz*. 

ittpi. The slips or dykes found in coal mines, may 

also be classed among the veins of stone. Thqr 
chiefly consist, as already mentioned, of basaltia 
and basalton, clay-rock, and argillaceous sand- 
stone. 

But the denomination of veinstones has been 
more strictly confined to the substances fomid in 

4 

metallic veins, which^ &oak their confined natnre^ 
perhaps more properly belong to lithology ; wfaence 
only a few observations are here ofiered, by way 
of supplement to a treatise on rocks; as they 
often perplex the learner, and sometimes even the 
adept, by combinations which do not occur ia 
mountain masses. A short account of these vein- 
stones, ^ven by an honest practical miner, maj 
AjssBrtiiy not be unacceptable. '' What I call yeiDSfeobe^ 



• lb. Now l6f p. 99i 



TBINSTOHBt* 



*7d 



15 a compound mineral concretion of various co* 
loiirs^ appearances, and degrees of hardness, and 
not unfirequentiy of various colours in the same 
mass, though white often prevails. This com- 
pounded stony concretbn is called by miners a 
rider, -perhsLipB from its riding the vein, or sepa* 
rating it longitudinally into two or more divisions. 
This mineral stone is hard and heavy, sometimes 
compact and solid, "but finequently cracked and 
cavernous, rising in irregular and mishapen masses, 
and gaieraily exceeding hard. A rider frequent* 
ly contains a variety of diflferent substances or 
species, as well as different colours,inthesame mass, 
such as spar, quartz, fragments of the rocks near 
the vein, sometimes pyrites,' and often ore in grains 
and flowers, and sometimes diffisrent ores, as lead, 
copper, &c. in the same mass, and all these strong* 
ly coagulated or concreted together by a whitish or 
a brownish-white substance, resembling quartz and 
a^vte, which seems to have enveloped the several 
articles in the composition when the whole was in 
a fluid state. I call this veinstone, as I think the 
term should be the most intelligible to naturalists, 
it being always found ia vems, upon the super* 
fides of them, and- in fragments and masses lying 
about upon the , hee of the ground, which have 
slidden, or been forced off, the superficies of veins. 
But the veinstone does not always contain so great 



074 

a variety in its compontian. It is often pMtf 
wiutey and oppeacs Uke a quaitzy oonoretion of m, 
porousi or rather a corenxHU textore; md Ae in- 
side of the caverns, thougfi small, freqnentiy ooih 
tains a brownish femigmons soft soil of a^snnfiy 
annearanoe: and sometinies the ^lyffAw of theaa 
somU caverns axe findy lined wkh great numbers 
of pointed or prismatical crystalsi generally ex- 
eeeding beautiful, and sparkling like dieniond& 
But all die veinstones, or riders, are notiriiite nor 
whitiBiL In many pboes th^ are of a brown, or 
a reddish-brown, and several other coloufis; but 
the whitish oolour most commonly prevails. 
Strong wide veins often omtain a large rib of this 
veinstone betwixt the sides, several feet thick ; but 
in all degrees of thickness, from a few inches up 
to several feet, 1 have seen strong bdd vdns carry 
such a rib or body of this stone as to appear in a 
ridge above the surface of the ground a great way, 
the superficies of the native rock being withared, 
and wasted away from faodi sides of it"* 

This description clearly applies to quartz : and 
be afterwards proceeds to mention that the dnef 
spars, found in mineral veins, are the calcareous 
and Gaok*spar, since called barytes. The Mk 
mineral soils found in veins, area idate, or wUlirii 

• WiUMU(,Jin.Kh»LssS. 



d75 



Itole; a red nacteMnas ierf upn ous clay ; wiihoAier 
IdndB afid colours, especially that called gur by Gar. 
tte GertMnSy of various tmts of brown, and Wh 
aml^ttag rappee, and sometinies l^panish snuft 
The peach of the Cornish miners, chlorite, or 
green bole, is also fneqoent 

From the account which Williams gffes of the Bidcr, 
tUkr, in the very imperfect mineralogy language 
of that period, it would appear that he means to 
ifldicale a vein of ferruginous quwtas, generally 
^nd to accompany metallic ores. By his de- 
^ertptiott it is very rough and irregular, and foil 
9t little cavities, containing a ferruginous powder 
Uke snuff. The whitest parts have some resem- 
blance to what is called a buv'-staney chiefly used 
tsr i^kstones, Ihefar irr^ular surfece serving the 
fiirpose of trituiation: but the rider genially 
etetains heterogenous substances, as ores, pyrites, 
•par, 4ttor, ftc.* It seems often to approach 
keralite, or the homstdn of the Germans, whieh 
fometiinea even fenns mountains, replete with 
aflVer and other ores. 

It wauld seem that the cavities containing druses 
<of small crystti^ chieAy oocur in the purer por« 
llansoftherDck; and his account of lids beantIM 
littd of veinttDnes merits transcription* 



it< •^WBLLaw* 



576 ummMMMn. 

liochf. '< Moit of the. .mineral; spm are ffeqaently 
foimd shctf into prismadcal, cvbic iiexagooate, or 
other .figures, llieae .figured .crystieUa afift igep^ 
raUy tmuepaffenl, andirery beautUuU it is a gp^eat 
xuxioaity to bebdid the iu»de of some q|f the large 
cavities in which they, are fonmd. . These opea 
caireras are firequendy met. with^^in.. hard mioeFal 
veins, and they. are. generally call^ by mineiv 
lochs, or loch holes. • 

*^ The nnnars know nothing of the^e cavoropoa 
vacuities until . they strike into them, as . th^y ad- 
vance in working ; and they ^re of varioiW' dimett* 
sionsy firom the bigness of a nut, op to room 
enough fat three or four men to. turn th^nse^yesn 
them. 

<^ The magnitude, of tbeae .cayei^s is.generaUy 
in some proportion to theicapadty.of the.veios an 
which they are found;. and the insides of diem 
fitequently.exjiftibit. all tibe. variety,, beauty^^/and 
4ildendojir of the most curiooa grotto-fwcrk* 

'^ There is commonly a l«rd eonisreted' stony 
crust, called druse, adhering to. the inside* <tf tiha 
cavity; out ^f which, as oot <^ ft root, an inno- 
mereble multitude^ oi ^hort . prismatical .cryfi^$U 
are shot, which q^kle.like^a jtt^jBapd diaflKwds 
with the candle, or when brou^ up to t^ .stfq. 
Between these clusters of mock diamonds, and 
sticking to them pfamiacvously, there are oAeo 



VBiiftTOfrtf« 577 

4 

ore, pyrites, and spar, shot also into prismatical, 
cubicj and other figures ; and besides these, clus* 
ters of grotesque figures which grow out of one 
another, and are as it were piled upon one an* 
other. The whole inside of the cavern is some- 
times most magnificently adorned with the most 
wildly grotesque figures, which grow upon and 
branch out of one another, in a manner not to 
be described ; and with all the gay and splendid 
colours of polished gold, of the ndnbow, and of 
the peacock's tail, and all these blended together,^ 
and the masses reflecting all the beauty of such an 
assemblage of gaudy colours. But it may be re- 
marked, that these caverns are never so magnifi- 
cent and glorious but when there is less or more 
of yellow copper ore, or of the pyrites in them s 
as these ores are found to produce, in hard veins^ 
the most beautiful colours in the world. An emi- 
nent instance, in proof of this assertion, is to be 
seen in the copper veins in the parish of Colvend, 
in Galloway. 

''These mineral loughs, or caverns, are the 
great source of materials for grotto wwk ; and the 
specimens collected from the mines are generally 
the most showy dazsUng articles in the whcde ar- 
tangement of the splendid grotto.*^ 



• waLi. 

▼OL. II. S « 



578 9VFI?I>BMENT. 

From tbe plain det^Uis of thishonqst iDinei:^ it 
ahd appears thbt the rider oAea arises like ^ w^ 
in the middle of the vein, the ore being foimd tm 
either side ; whilb sometimes, . on tlie conttery^ 
the ore is in Ihe middle^ and t!bd rideir on. ieaeh 
Mkien' temii. ^kI^; Qf, to ttse the mining lahgctage, the hanger 
^^ ^8?^9 ^ hMging OF uji^per side, and the 
hading or lower side ; for the Iuide,slopey or incli* 
Mtion of the vdn is thie&y estimated by idkieni 
frodi the lower aide, wjhile the directtan is by then 
9alled tbe bearing ol tbe vem. The back of tiaie 
rem is ako called the basset. What the Germans 
call the besiege lA described by Williams as a thin 
s6am of day, by the miners called a sleeking^ 
He has observed tvtro rich veins of Ited^xr^ 00 
the sides of li rider of whinstone or basalt. Sonie 
veins have little or no rider, but .only OPe and 

. Ano&er substance, not nneommon in veins, ia 
^' diaihibtoliHC combii^tion of silex and iron ;. ibr 
there are few mines in which iron does not tocoaif 
paby the other metals. . 
siiez often . Jhis siljlii. must^ accdrdiris to tbe doctrine .^l 
Werner, be often of rteent formation. But sta« 
laotitte jof silex Inay be said to bb daily formed ia 
the deepest gallery gi ihi tUmiB of Cremnita; and 

• lb. 969,JnS,,90U 96t, 377> 379- 



•I 



TBINSTOHBf* 57^ 

tee ranarkable^ when they have attained several 
iiichee of leagth, by their extreme flexibility^ while 
calcareous stalactites jure broken with the slightest 
effort*. In his account of his own cabbet, Trebra 
mentions that, in 1782, a peasant <iigging his gar* 
den VI the ?31age of Seppenrode, dependent on 
the bishopric of Munster, found a grey ffint, about 
nine inches in length by four in breadth, having 
nothing particular in its exterior appearance ; but 
having broke it for his tinder-box, he found withkv 
a cylindrical cavity, containing twenty fittle pieced 
oi siLveri which appeared to have been tied with ai 
tbrexid, of which aome vesti^ were apparent 
The cavity was exactly moulded on Ak little pSd 
of coins, and the inside was black ; bat the most 
9urpa»ng circumstance is^ that the most ancieM 
of these coina are only of the aizteenth century^ 
Trebra's cabinet cDntained a piece ^ this flit^ 
and one of the corns presented to him by Prince * 
GalUtsdn> with mi authentic certificate of the dr* 
comstances above^mentionedf . Mn Kirwa» faatf 
another example of coins found in ffint};. 
In Ins barge work on the interior of mocstitains^ 

* Joonf. det Mincty Na sa^^ f • 76. 

t ibid. p. 75. 

X Geot. Em. 447, where he briefly quotes Schneider, Top. Min. 
114, for lS6t]lverooiiuf<mndinfliiiUatGriiioci&I>eii]|iAi1c, and 
in iron nail at PotMb«t» 



jgQ SUFFLBMBHT. 

Trebra had before stated a fact more applicable to 
the present subject^ and observed by himself in the 
nxine called Dreyweiber, in tbe district of Marien* 
berg. In 1777, on enlarging and opening that 
min^, which had been under wata* for two hun* 
dred years, four standard posts were found, farm- 
ing part ;of the fabric of an ancient pit. The 
lower ends' of these posts were buried in a new 
vein, consistmg of barytes, of a flesh colour, and 
of greeii fludr. Moreover, the extremities of these 
pieces of wood were ' dovered with a black and 
^roWQ ferruginous matter, containing much vitre- 
ous silver ore, and native silver in extremely thin 
leaves^. Fi^om these and other examples, it may 
be inferred that substances^ reputed the most 
primeval, are in fact daily produced by nature ; 
and that the same, Power which has impressed 
such wt>t|d<erful and perpetual motion on the pla- 
• netary; bodii^^, also animates^ so to speak, their 
interior ; .where to suppose Absolute death and in- 
^rtion,, would be to contradict all the otlier pheno- 
mena. . ; i ' : * 

A^ of Tela. AcGordifig to Werner^ the most ancient v^is 

••****^ present felspar, schorl, topaz, and beryl. Those 

which yield grey and green mica, are also veiy 

ancient; while the calcareous stones appear more 

* Jour, del Miaei» t. 79U 



▼SIVITOIItt. Jg 1 

nodern ; appatite and some fluors being the oldest 
of this description. Barytas seems one of the 
newest substances which appear in veiiis. Quartz, 
if not the most ancient, appears to be of all ages ; 
while wacken and basalt seem to be recent. Trebra 
has observed^ that certain gangarts se^m more 
generally to be found in certain kinds of rock. 
Quartz and barytes are more frequently found in 
granite, than calcareous spar. Porphyry also 
contains much quartz, little barytes, still less cal- 
careous spar, and almost never fluor; but there 
are gan^trts of chalcedony and jasper, which are 
seldom found in granite and gneiss. In argilla- 
ceous mountains the prevailing gangart is calca- 
reous spar, wlnle barytes and quartz are rare« In 
calcareous mountains quartz seldom occurs, while 
calcareous spar, barytes, and fluor, are abundant 

In the mines of Giromagny, in Alsace, the ' 
dnef gangarts are quartz, trap, fluor; the rock 
being almost universally what was called petro^ 
ailex, more probably homstein than felsite. The 
direction of the veins is very various ; and those 
that are north and south sometimes have their 
inclination to the east, sometimes to the west*. 
Amoi^ veinstones must also be reckcmed bricias, 
compcMsed of flragiments of the mass of the veins, 

• Sm dM table, JowriL da Mioci, W. Wgi, 



and alleged by Werner, among hb arguments, 
that the veins were filled from. above. Such is a 
bricia, consisting of little fragments of barytes in 
a cement of bluish grey ihior. Bnt he particular* 
ly instances the celebrated bricia of agate, found 
at Schlotwitz near KunersdorfT. This singular 
Afite bricia. and beauttfril stone consists of lai^^and ^maB 
fragn^i^its of a fine ribon agate, which forma a 
powerfiil vein in that spot ; the fragments being 
joined by a cement of amethyst and quartz. In 
the polbhed specimens there are firagments, of 
which the parts correspond so exactly^ tjiat it is 
evident that they must have dn^ped fr<Mii the 
same portion of the vem. 
Among singular veinstones may also be classed 
pebbiM. pebbles. Werner mentions that a van of pebUas 
of gnebs, fourteen inches in thickness, was found 
at the depth of 180 fathoms. In Hessia, a vein 
of cobalt, almost vertical, was traversed by an* 
other vein consisting almost entirdy of sand and 
gravel. At Chalanches in Dauphiny, sevwsl 
veins are entirely filled with rolled pebbles. But 
one of the most remarkable examples is reported 
by M. Duhamel, in his Subtmranean Geometry. 
The principal vein o^ the HMne of lead containing 
silver, at Huelgoat in Lower Brittany, is accom- 
panied, as well on the roof as on the sole, with 
ten or twelve feet in tiuckness of rolled stones or 



« 



pebUes, of various siises, eitlier round or oblong; 
the greatest number bemg of quartz, like those 
Ibund on die shores of the .sea, and in the beds of 
rivers ; while the intervals are filled with a white 
earth, someitiaies ochry. The works are 500 feet 
under the mountain, and the inclination of the 
vein is from 60 to 70 de^eesr Duhamel adds, 
ttmt the disposition of the vem admits no- doubt 
that it has hetn fbtHied after the banks of pebbles, 
which ^erve 4t as wi&lls : and that it may be in-* 
itned that the two banks of' pebbles were at fitsl 
toited, and' idt^wards rent ^and> filled with dm 
vtin. 'But may it not be simply a pudding-stone^ 
ef which the cemestit is d^bmposed, a ^mmon 
dfeet of metallic veinsf*^ ? l^wt] is it wholly inoon- 
eeivablcf that the • vast - receptacle of subtarraneafli 
waters, known to exist in many parts of the globe^ 
may contMi extensive beds ^of pebbles, whieh ^ 

may'l)e forced into any cavities by the prodi^ous 
power of eaithquakes, or oilier phenomena^ occa* 
sibned by the extreme force 6f steuafi, .vapours, 
fend gases. ' ^ 

Among the most remarkable veinstones must FMnfiietiMk 
also be classed petrifactions, which have unex-> 

ft 

• Danb. Theorie de Werner, S3. Near Gienock in Scothnd^ 

• 

ore 11 foilbd in pnddMrttoc^ .WP-Jt.iH^ 



584 A9FPtBl»RT. 

pectedly been fotmd at great dqptba. , Bom 
assuresr us that petrified porpites (a kind of. mol* 
lusk), have been repeatedly found in a mine oi 
Hungary, at the depth of 89 £Bithoms, Or i34 fe^ 
Fichtel has also observed, in his work on the, Car- 
pathian mountains, that ia the nunes of Hungary 
has been found a fungite as large as^a^nut, Ijhe jia- 
tallel leaves containing a little ball enchased in 
the interior, the substance being now spatix>8e iron» 
of a deep brown; fuid :it rests on crystallised 
quartz, covering the decomposed pcurphyry, called 
saxum fnctaltfferum . by Bom, and . here styled 
bomitCy in honour of that great mtneralo^bt 
There was also found a bivalve shell, of the ske of 
a .filbert, likewise, pla^^d on quartz and bornifee. 
. The tvifo valves were separajbed. finom each other, 
^ut entire. Fichtel adds, tliat he has in his poa- 
sesaSon a cochlite, or searsoail, fqundin a vemci 
gald in Transilvania^. Mi^t not even these 
relics arise firom subt^rape^n waters ? 
Deeomoied , Finally, amoqg.yeinstones may also be dassed 
those decomposed rocks, generally occurring in 
the proximity of metallic veins, and which having 
a more immediate relation to the present worl^ 
must be treated with some detail. 

* Werner*- llicorie, 80« MO- 



r 



; Werner h9a inforined us ttiat, in many teins, 
the rock .on both sides^ or, in the miners' lan- 
guage, the roof and the sole, the hanger and the 
leg&j js altered and deoMoposcfd. This accident 
chiefly takes {^ace in mountains of granitel, gneiss, 
mica : slate, common slate^ and porphyry. ^ But 
this decomposition seldom extends to more than 
one. of. .the constituent eLements of the rock ; for 
the qu&rtz remains entim; while common^, the 
felspar, oftm the nuca, and very dten tfafi hom^ 
Ueaoids^ iure decayed ; the potash of the ohe^ and 
the iron; of the others, being very liable to decom« 
position. This alteration sometimes extends a 
considerable way, even a fiathom; and is not 
always apparent along the vein, but chiefly in 
tho» .parts where the mineral abounds with sul* 
phur. In the pursuit of a barren vein, when this 
decomposition begins to appear, it may be con- 
cluded tl^at ore is not fiur distant 

This, change Werner ascribes to acids in the 
dissolution that formed the vean; and supposes 
that the felapar is changed into kaolin, or white 
day^ by the carbonic add ; and he gives examples 
of gneiss and granite thus decomposed. He also 
supposes that the sulphuric add may affect the 
mica and hornblende, and convert thrai into that 
green bole or lithomargay which was ori^nally 



586- fi^nnsuciinr.' 

called gums by the Saxon miners, befove the 
term was transferred to the entire rock now so 
denominirtsd. 

Daubuisson, in his able translation of Werner's 
work on Veins, has ^ten two remarkable exam* 
pies of the decompCKsition of granite, which may 
best be^ explained in Ins own words'^. 

'^ Near Bautzen, in Lusada, in a hollow way, 
there is a cut made into a granitic soil, wUch is a 
mere assemblage of balls of granite, mostly a 
iktiK)m in diamet^ ; while the interstices are of a 
granite, decomposed to such a degree that the 
spot resembles a gravel-^pit The balls are cover-* 
^ with envelopes, consisting of many layers of 
granite, also falling into decay* I obs^^vedone 
ball which had thirteen of these en^lopes, each 
nearly an inch in thickness, and the mora deccmi- 
posed as tiiey were distant from the kernel. A 
ball detached from the mountain, having split m 
the middle, afforded me ah opportunity of observ- 
mg the nature and structure of that l^mel, whidi 
consists of a fair solid granite, of a hardness and 
freshness of colour, (koionstrating that it has suf* 
fered no alteration ; nor does it preset any fis** 
sure, nor any lineament of a struttiive in conceo* 

• Thforle, 148. 



trie layers. For these circumstances I shall thus 
account The granitic rock being divided into 
masses by horisontal and vertical fissures, as most 
^granites are, the decomposition arising fi*om the 
atmosphere would first afiect the angles and sides^ 
and reduce them into that kind of gravel of which 
we have spoken, while the masses of course as* 
sume the form of balls. The decomposition^ 
afterwards penetrating gradually into their intariory 
would successively relax the tissue, and thus faan 
concentric layers; while the inmost part would 
contmue to preserve its solidity, thus forming the 
kernel. One of the effects of the decomposition 
has been the oxydation of the iron in the felspar^ 
whence the red 'colour of the gravd, of the con«i 
tentric layers, and all the decayed parts ; while, 
m the kernel, the felspar is of a very firesh Uuisih 
white. This oxydation of iron, by the common 
influence of the atmosphere, is the cause of several 
appearances in rocks, particularly the sandstones* 
In one of the balls, which was on the sur&ce of 
the earth, the upper hemisphere of layers was en» 
tirely wantbg, the fresh and solid keroel being 
displayed ; while beneath it was enveloped by the 
bwar hemisphere of decooaposed layers^ the upper 
hwing been carried away by the winds, rains, 
and other meteoric inftie&cei. I report this Act 



588 tvniiSicBNT. 

as leadflig to the remark, that althouf^ certain 
masseis, peaks, rocks, &c. which we see bare, 
always present a very hard substance, seeming to 
defy all decomposition ; it is neverthdess subject 
to the destructive power of tune, or more strictly 
speaking, of the elements ; but in proportion as 
the particles of that sur&ce are thus decomposed, 
they are washed away, so that we have always 
under our eyes the solid part, not yet affected by 
decomposition. 

' '^ The second example which I shall state, ap- 
pears at the Seifienwerk of Steinbach, near Johan- 
georgenstadt in Saxony. When I was ther^, and 
in front of a mountain of granite, of which the 
surface was entirely decomposed, at the first 
glance I thought it was a mass of sand or gravel ; 
but, on approaching, I perceived that the grains (tf 
quartz had the same colour and the same form aa 
in the granite of the neighbourhood, and were dis- 
posed in the same manner, but in a felspar com^* 
' pletely decomposed. This decomposition peQe^ 
trated a great way into the rock, as I observed in 
passing into a gallery, where the granite did not 
appear firm till at the depth of several &thoms: 
and I am persuaded that in many places wl^t ia 
reg^ed as gravely produced by alluvion aod 
transference, is only decomposed granite in its 



M9 



M^al situaticn;.aiid fliat under:thu p w t— daJ 
gntrU would be found tb& solid rode ' ' ui 

:: ".'I diaU not bere enlai'gp ^.i1k destiudist 
power of the demeI^s, but leserretiie subject fair 
another woik;' where I ^lall afaow, by a' aeriefa of 
fiicts, its consequemes in granitei,> sandstooe^ 
basahs^andfOmoit all tbe Todi^; : i shall shoir 
that acting constantly, and without interruption, 
during a long series of ages, it must bare pro- 
duced very great efiects on the solid crust of our 
gtobe ; and has BU^n^y concurred in fiubionii^ 
the inequalities, now observed on its sur&ce. I 
■hall with regret be obliged to combat the opinkm 
of Dolomieu ; the vivacity of whose imagination 
could not bear the slow and uniform progress, 
which experioQce shows to be that of nataire. He 
said hf 
bare ft 
serve tl 
tion: s 



It is 
fident. 
tkn to 

or in cabinets, have oAen been confounded with 
rocks. In the latter, particularly, they have some- 
tmet led nuneralogjuts, and even gefdogists, to 



«90 



^lirmff apd. cmobeous mfisEBoces. But, in ihs 
rapid advancek of tfae Bdence, die kmp cf obaer- 
vationwiU. sobnidiapel anjrolMi:in%; and when 
facts shall beconne snffidendy. Dumerous, it is t^ 
Ik hoped tint 9om&fatuie Newton: may ariK, to 
^spel the dpikbess abd <T«*ft^»i"" wliich stffi 
jfnmS in niftny liactB <tf the nUBniL itwig H CT w . 



r.,.. J . 



APPENDIX. 



APPENDIX. 



No. I. On the ancient Manner of carving Granite* 

Z0S6A9 p. ]89, et seq* 
[See the translation. Vol. !• p. 199.] 

ReUQUUM est dicere de Barberino bbelisoo. 

Nempe ad eum scalpendum ixistromenta qusedam adhibita 
yidentur quorum in magnu Obeliacis nullum deprehenditur 
vestigium. Que enim lines sunt recte, yd ad drculi seg- 
mentum curvatse, non acut6 ineisae sunt^ neque profundi- 
tatembabentequalem: sed fundus ooncavus est; ipsisuldin 
medi& sui parte proftmdiores> ad extremitates sensim es« 
tenuantur, donee paulatim evanescant. Nee desinunt puncto 
definito in eo loco> qui terminus est rei quam representandam 
sibi sumserat sculptor, sed exilior pars procurrit extra limites 
figurie. 

Unde clarum fit ejusmodi sulcos non &ct06 esse stylo nee 
smyride lamin& cultrifbnni subacti, sed serra aliqu4 lunat4, 
cui subjiciebatur smyris, et altemo motu inddebantur sulci. 
Sed in rectis lineis; ubi vero cunrs essent, serr& etiam opus 
erat curvd. Qaoniam vero figune incavita te eminentes turgi- 
diores sunt, et singuls partes aliqua deformantur globositate, 
probabile fit eas teretro vel tubo fbnnatas esse smyridb sub* 
sidio, licet ejus instrumenti vestigia non appareant^ figuraram 
superfide fricando expolita 

Universim in hi\)U8 classis operibus tempus lucrifacere 
studuerunt artifices ; et serris, tuctris, atque frietione efBcere^ 

VOL. II. 2 Q 



594 AFPXHOIX. 

qus in magnis obeliscis coelo £eM:ta videntuTj yrek sm jxide 
laminae subjecta 

6. Nostrates ubi granito figuram aliquam inddere volant, 
primo loco exemplar ejiis faciunt^ d ferri lamini subtili^ qui 
super piano saxo iq^diaato ae velnt aggiutinata, asaumpta 
altra lamina, brevi cultro similij ea utuntur ad sulcum da« 
cendum; ope smyridis circa exemplar supradictum. Sulco 
autem ad certam profunditatem impre8so> exemplar aui^^runt, 
et spatium sulco defimtum, acuto sodpro (iubbiq) commimiere 
inci|iiuAt« Dcia malleob nacfcmato tpmng^to) Ibnaaie 
aggrediuntur figuram .... quam postea malleolo latioi« 
(nuxrteUxno) molliorem reddunt et Isviorem. Quo ikcto amy- 
ride plumbo subacti ksvigant Dain exiliora lineamenta par- 
tim scalpro coelove a^jiciunt, partim lamin4 cultrifomii et 
sflQjxida. Postremo vexo. omnia expoliunt nnjrida iaiBiKii» 
tima qnam ipoUHgUa vooant. 

r. IM Rosso Tost%iadsprdien£t Untri in Obdlpcd Hello* 
pcditano $ neque sine hoc instrumeuto dMiraoCa^ 
in saxo granitioo contendit : sed loqui videtor da re iM tarn 
IntalleetL Nam ooomnmb Untri (tefetnm id. q. fntpta^ 
mdlus usQs sit in 60 lapide* eum Ibito stt Ipse d«rlor. 
Ahsrum r9Xo Hrtttoa, quod Udm tst aasMs, smytide chtw * 
gendis deslinatur, Uctt commodom instnimeBtuiii, tameii 
inii^fne est nsesssarhun neo nisi in profendis exoavatioiiibat 
eo uU Solent nostrates.. 



No. II* Illusirations of the ancient Marbles* 

Whitb. Pcfrian, also called Lychnitei aind Lygdif, 
fiymettian. 

*f Non tnbet Hymetttft 
PremuDt ooIumnM ultima McSnt 



APrSfllUK* g^ 

f^ Pentelkan, 
Mylassian, 

I JVoGonneHan. Tomb of Mausolus* Vitruv. 

{ Thaiian. 

, Caralian from the river Coralius in Phrygia ; also called 

I j SangarioD, from the river Sangarus 3 resembling ivory. 

^ Phoenician, TyriaOj or Sidonian^ from libanus; used in 

^ the Temple of SoJomon. Josephus. 



I 
I 

r 

* 



Arabian. Diodorus says^ that in weight and whiteness it 
exceeded the P^ian. 

Isshiam greyish white (PalombiBo) j iko dbrk grsy. 

Canchites, white with shells. 

BtACK. Prom Tananu in Laconla. 

^ Quidf« Anras prodest Fhiygiis itmlxa colttttnli 1 
Taeiuure sife tuii, sive Carjste tuis." 

*' Quod non Ttenviii domnt est mihi &lt« columiiiB." 

PnpCfU 

The green wat IKim Mount Taygetus. The Crocian waft 
ffobably white, m fttatnes were formed of it. 
Lydian*' (Basanite.)* 

Qbbiit. Of Moant IViygetus in Lactmia, which extends 
fliiough that qottntry to Arcadia: (^erde antico.J 

** IlUc TayvMi TiKBt wnih." 

MvL 

^ £t ipidl viMMi Ibhta lavit Enratift.*' 

/if. 

^ Heic dui» Ijuconnia 

Sttt vikdL 

^ The itone of Akbtnda in Ctxift, black incUnlog to poiplei WM Bidtad 
fnd incd fir ^(liis (IKIiiy), to could iiot bt a i&arble. 

2 qS 



i 



596 



APFSNBIX. 

** Heic et Amycbei teflom de monte Lycuigi 
Quod yntetf ct moUet imitatur nipibut herbas." 

Id. 

'* HeiboM qiae venmit manncn vrait." 

i(i 

** Post caute Lacomim 

Maimoris hoboti radians inteirirf t oido/* 

Id, 

ProcopiuB de JEd. compares it to emerald. 
In a noted passage^ Sidonius thus describes the 
bles of antiquity : 

** Hie lapis est de qoioqae lods, dans qoiiiqiie colores, 
iCtbioposy PhiTgius, Parios, Poenus, Lacedsemoo, 
PurpureiiSy Tiridis, maailafosy ebunmsy et albas." 

African red^ Phrygian spotted, Laconian green, Fbcian 
white, Poenus like ivory. 

Carystian, green, yeined and spotted, also called Euboean. 
As it was spotted, it is probably the verd onHque sanguine, of 
a deep sea-green with little red and Uack spots. It was 
most probably a serpentine, for amianthus was found in it, aa 
is dear from a passage of Plutarch. 

** In some countries we see lakes and whole riTers, and not 
a fbw fountains and springs of hot waters, have sometimes 
foiled and been entirely lost; and at others, have fled and 
absconded themselves, being hidden and concealed under the 
earth; but perhaps, some years after, do appear again in the 
same place, or eke run hard by. And so of metal mines, 
some have been quite exhausted, as the silver ones about 
Attica ; and the same has happened to the veins of brass ore 
in Euboea, of which the best blades were made, and hardened 
in told water, as the poet JEschyhu tells us, 

' TaJdttg his moord a right Euboean Hade.* 

*TiR not long since the quarry of Carystus has ceased to 



€f 



AFPBHDIX. 597 

yield a certadn soft stone^ wfaich was wcMit to be dxawn into a 
fine thread) for I suppose some here have seen towels^ net- 
ymitk, and quoife woven of that thread which could not be 
burnt; but when they were soiled with using, peopk-fiung 
them into the fire, and took them thence white and cleani» 
the fire only purifying them. But all this is vanished, and 
there is nothing but some few fibres, or hairy threads, lying 
up and down scatteringly in the grain of the stones, to be 
seen now in. the quarry."* t 

jitracian, from Atrax, a town on the river Peneus, not &r 
lh>m the celebrated vale of Tempe, in Thessaly, whence it 
was also called ThegsaUum. \ 

The ancients included all the rocks used in sculpture or i 

architecture under the name of marbles ,- but the verde antico, 
which is really a serpentine marble, is mentioned by so many 
ancient writers as the most cheerful of aU, with veins of a 
grassy appearance winding in a spiral manner, and presentf* 
ing white parts when polished, that no reasonable doubt can 
be entertained of its being the Iiaoonian sort. 

Paul Silentiarius, in the sixth century, wrote a poem, in 
which he describes the decorations of the famous church of 
St Sophia, then erected by the £mperor Justinian at Con* 
stantinople. The subject led him to a minute description of 
the most celebrated ancient marbles; and that of the Atnu' 
cian, contained in six lines, may be thus literally translated. 
" Whatever the Atracian land produces in the pkdns, not in 
the high mountains as the other rocks, in some parts of a 
light green not &r fh>m the colour of the emerald, in others 
proceeding to a deep and full green. There is ako something 
like snow added to a black splendour 3 all which concur to 
form one beautiful whole." From other passages of andent 
writers, it appears that tlus stone is described in the mass, as 
being of a leek green 3 whereas the Laconian is mentioned as* 

* Plataxch's Moral TmtiBes, W. 54. Tournefort, TniTds, I. 176, mei^ 
tM^Qi amianthus from Caryaiiu, ai being now an inferior kind, imposed on th« 
ignorant as |>lumose alum. 



being of tbaeolourofteaikrlierlwergittai Thfcie JMtt^ - 
dma can toBfcely In more joatljr upijpiM tbau to wtatt luv 
lieeti called green p^nphyxy, tbe enoiMoiia njukkm of anavgr 
BKxIertt authors, the base bang of a leek gnem, while tkr 
cryrtak of felspar approach the < emerald colour> and k is 
eftea spotted with white and black chalcedDDji anA in otker 
iDstanees with white felspar and bkck siderite. This beaMt^ 
fill stone seems to have been dinoTCred after the emjnre 
transferred to Constantinople; for it eseaped the 
dassicB, and continues to be celebrated fran the limn of 
Justhnian^ and that of Basilius the Macedonian^ to thai tf 
Eustathhis in the eleventh century, who menUona it» in the 
love vtory of Ismene^ as quite distinct from the Laconiaa. It 
has been generallv su{qposed to be from Egypt 5 but is not 
ipeeilied in any of the recent descriptions "as being baad 
fa) that country^ where the red porphyry is not unconunoiiy 
and ie found in pebbles in the univenal bricia* The 
masses found at the harbour of Ost ia, only preve that It 
brought by sea to that sole port of Rone*. 

RxA. The Rosso jtintioo. The aneiiinto aaen eemctittee 
to have confounded red marble with porphyry^ wlifcdi vm 
quarried in the Thebaid. But statues show that red marble 
was also found in £gypt> or tiie adjoining countries; and it 
» highly probable, if not demonstrable, as already Tpl«?iiM4 
that the Angusieum and Tiberianum of Hiny aUuded to Hut 
red, purpurtnup or imperial colour. One 4dnd of the Basse 
aniico is JtoritOf that is tlK Augusteen ; another all dotted 
over, the llberian. The colossal statue of Agrippa, fonmriy 
in the Psiithcon, now in the Grimani palace at Veaioe^ is of 
Adsio aniico. 

• Ybllow. The Numidian. Paul Sil. says yellow and gold 
(Lumachella Castracana?) and found in Mount Maurausis 

* Wad has one Egjptim reHc of what be calk green poi^tiyiy, a scanbtfoa; 
but it is of homstone. 



(MMnaim €ft AmntSm). hwa0alHyintadi|tolUillnCbred 

and white (Jfricanojlorito, RezziaioJ* - 

*^ Sola nitet flavis NoDudam decisa metallis 
Furpora." 

« Heie Nanadmn Idcrat ImmmU MM." 



S99 



** If omadttm hpb idftttt tek, 
Antii|Mm BMMltii eboA" 



Precisely the Gta/Zo oit^o. 



M.JpolL 



Bluish GreY or Torquih. Thk, as wdl ad the pure 
white, was found at Luna. Strabo. (BigioJ 

Variegated. Phrygian from Synnada^ the Fkrygias lofAs 
of the classics; wMte, with red veins and spots. 



** , • . • . M ■urtte i c picto 

Candida purporeo disdnguitur area gyro." 

StaL 

" PoTpuia so]a» cafo Phiygbar^piod Syanadoi 
Ipn cemwtKnt maeiib kcandHi Atys." 

SifiL 

Tde spots either rose colour or' deep red fFlore di Portico, 
Cipolaxzo, Coionello, Porta tantaf.) 

* the Ckdio Anmdato or ringed maibfe mtf be allailed to by Pfttky, isxr. !• 
^tllMi Ik tpcakfOf egg figma baingaftiflciaUy inaarttd. 

Whit it called Afrktti Brkit b quite caeneoii mtn in Fighnd> aii4 it 
<{aamed at Suavezu in Tuscanj, pieteatiog Inge piecei of bioirn, leddisl^y 
and vhlte, on a black ground. There is no ancient authority (or its being 
African* One kind, however, resembling the Picfe di Persicog Brud^ 34S9 
rightly conceives to be from the same qnarrief, thar is, 9ynnadic or Phrygian. 

f Specimens of two inches of coune vary much. Laiger pieces woold 
iMMr isajimiwe the kinds. AnUm, Kkc OriMtei in geM^ tMiiti«n ftily 
ImpUea a besntifbl naritle. 



600 APPXHOIX. 

fiAodiofi irith golden spots (serpentine with mi^ OccAio 

Corinthian, Jiams, yellow with spqts. (CaneUof Perhaps 
Giallo e nero.J 

Ckian, black or dark with spots. (Pavonazzo? Ocdno di 
pemicef) 

Judaan, flame colour (DoraiafJ 

Tcmromenian, variegated. That of Taormina in Sicily (Red 
spotted with black, or a deeper red; or veined with white, 
BrocaielioneJ. Also> greenish with red spots. 

Gibbon, viL 180, describes from Faul SUentiarius the fol- 
lowing marbles of St. Sophia. 

Garystian, pale with iron veins. Phrygian. 

Caiian from Jassus, veined white and red. 

Lydian, pale with a red flower (a fiorUo,) African^ of n 
gold or safiron colour. Celtic, black with ^diite veins. 
(Nero e bianco*,) 

What marble appears in the ruins of Palmyra? 



Some farther illustrations may also be offered, concerning 
the ancient petralogy of Egypt. 

Plato, in TinuBO, describes an Egyptian stone as composed 
of red, yellow, white, and black. It is the noted granite of 
Egypt, says Garof. p. 42. Red felspar, yellow or white 
quartz, black siderite. 

The psaronion, also from Syene, derived its name from the 
white and ash coloured spots of starlings. Roziere gave me a 
specimen, which he found at Syene, intersected with a vein 
of red granite. Beyond Syene, Ethiopia was supposed to 
commence. Pftusan. EUac, 518. 

Eusebius, lib. viii. p. 420, mentions that Christians were 
condemned to labour in the quarries of porphyry in the 

* The Uack utd white Cehic may be gnxiUe, Hie li^spteutaria wtatm te 
bettlc 



APPBNDIX. 

Thebais. Paul SiL says it was brought down the Nile in 
large vessels. 

Some have inferred the word basaU to be of Hebrew origin, 
as in that language barsalt or bcarzaU implies iron. Belion, 
li. Eg. says he saw a pyramid of basalt as hard as iron. 

Ptolemy, iv* 6, says that the eastern part of Egypt, on the 
Arabian gulf, was possessed by the Arabs ; and among them 
were the quarries of lapi$ Trotcus, alabastrine, porphyry, 
Uack Hone (basalt), and of basanite. Herodotus, also, il 8, 
mentions the quarries in the Arabian chain. The town of 
Alakastran was so called from its alabaster 3 and PorphffHo 
from its porphyiy. See Garof. SS. 



No. IIL TJie value at Rome of Specimens of ancient 

Stones*. 

Vcdore di Marmi, Alabastn, Pietre tenere e dure, ragguag^ 
Uaio alpalmo cubico Romano, 

Marmi e pietre tenere, 

Sc. baj. 

Marmo bianco di Carrara, il palmo • „ 70 

Greoo „ 90 

nero di Carrara ^ 2 „ 

antioo, detto vulgarmente di pa^a- 

gone 8 „ 

giallo di Siena • S 50 

detto Porta Santa, antlco 5 

detto fior de peraico antioo 14 

detto Settebase semplice antlco ••• '2 

a rose antico 8 

giallo antico , ,.... 7 

in massa grande m..,. 8 „ 



601 



9» 
»9 
»9 



• Petrini Gabinetto del Colltfgio Ntareno, torn. ii. App. Tavola xi. The 
Somali palm ia about nine inches. The satda (which contains one hundxed 
JjtQQtciJ is about 4s* 6d« 



gQ^ APPSttOUL 

Bfanno Terde aniico di bella qualiti •••••••«• l^ m 

in maaaa gnnde •«••••« •••••••«•*•••• 90 ^# 

rossaantico ••»•»«•••••••• ^ 13 j« 

in maaiia gruuie« molto niio««*r««»M •«•••••••«■ S4r ^^ 

Affiricaao « •• • *•• •*••!»•••*•• 1 50 

dpollino »...•..••« •.••.••••••••«..••••«. ^9 60 

biapco e nero antj^Q... .••••••;.. #•*.»••»•« •« 30 ,, 

delle coste di FraociA***...^. ••#•*.»»•••••»•••••• 8 i« 

ISetra volgannente detta llfarmo di Pbkovcra ••«••.••» 3 50 

Ycrde Pcatow »••»«•«••••• •..••••^ •••••• 3 f» 

Porto Venere con Qiaechicgialk....^*.......*** 2 M 

Breccia corallina antica • 5 „ 

di Saravezza 2 50 

diFVancia.. *••...•. ^, •* „ M 

Jlabasiri, 

AUbtJiiro Orientale...., 20 ,, 

e peccH'ella antico ^ 30 „ 

di S. Felidta o sia Monte Ciroello....^......, 4 „ 

di Polombara c di Gvita Vecchia « 3 60 

di Montanto ..•••• 3 „ 

d'Ortebianco • ^ „ ^ 

biondo del fpsso delk Fboihu^**..*. 25 „ 

Pietre Dure. 

rosBO deHe Guglie „ 50 

in massa grande ...«..••• 3 ^^ 

Egiziano nero con macchie bianche rossigne 3 „ 
bianco e ncnro aniico^ volgannente detto della 

Colonna del Signore ., 8 „ 

in massa grande 12 „ 

porfiritico^ detto porfido rosso •••• 8 „ 

in massa grande ^. 12 „ 

prasino, detto porfidotverde • .^U 8 ,, 

in massa grande^ raro ,• 15^ ^ 



% 



^ 



AmiiBUb 603 

Graaitovoefita •* .^•••mm 6 ,^ 

stcatitico^ detto volgarmente Grttnitoiie, 

Itaaaco e Tcrde «• 6 ^> 

QnEinitelkK f. ,> SQ 

Basalte nero d*£gitto •...«•• 10 j^ 

Orientale verde ..« •%..•...,•» io y, 

Verde di Memfi, voj^^annente detto Serpenti»o aotkro 3 ^t 

Sreqeia d'Egitto d^ foncto yerdiao ••• 8 «» 

I soprammentovati prezzi si aumentano, non solo in pro- 
porzione della mole^ ma anche della beilezza della pietra o 
marmo. Cosi, per esempio^ il marmo detto Porta Santa se 
abbia colorito piu acceso > il verde antico se sia de macchie 
bianche e di verde pieno ben rilevate ; e il granito porfiritico se 
sia di color di porpora vivo^ con grani di felspato bianco rom- 
boidale; avranno sempre pregio maggiore. 



No. IV. Account of the IJillof St, GiUes, near Liege. 

♦ • 

Lametherie (Theorie, v. 71) has described the hill of St. 
Gilles, near Liege^ adjacent to the river Meuse (which is seen 
on the \eft, with the coal passing under it) from Genette : as 
in the plate here reduced. Dam. VI. 

The height of the hill is 2S^200 feet j and it contains sixty- 
one beds of coal, separated by other beds. Many of these beds 
of coal and intermediate substances are composed of smallef 
beds ; and, without doubt, the lowest beds of coal have not 
been discovered. 

The beds of the chief hill form a concave curve ; but after 
passing under the Mcuse, they become horizontal under the 
little hill on the left. They aftenvards ns^ and become 
almost vertical. 

On the other side, or right hand of the print, they are bent 
like chevrons 3 while the intermediate beds aseume the like 
form. 



604 APPENDIX. 

^e beds are intersected by three great dykes, called /atUet 
in Flanders, crains in France, 9prtmg$ or leaps in Germany. 

The firat, on the right of the chief hiU, is thin towards the 
summit, but thic]|ens as it deepens. The second is of great 
thickness, but does not pass the fiftieth layer of coal. The 
third resembles the first. ^ 

There is a great number of inferior dykes in this hill. 
Some are 420 feet thick at the depth of the lowest beds ; but 
probably they thicken still more as they approach the radical 
rock. 

All the beds of coal, wliich are cut by the dykes, are either 
lost in them, or continued in little irregular threads ; or are 
found behind, either above or below their natural directions, 
and never in a straight line. 

The mass of these dykes is chiefly of Tock*j others of 
sandstone, of agaz (that is, a ferruginous sandstone) ; or of 
earth, with here and there broken coal. 

Beds of the HiU of St. GiUes, which continue for more 

than a league. 

1. From the surface to the first bed of coal, 21 feet. (Th^ 
Liege foot is 10 inches French.) 

Thickness of this bed of coal 15 inches. 
3. Intermediate bed 4^ feet. 

Second bed of coal 1 f. 7 i* 

Divided into two by earth nearly an inch thick. 

3. Intermediate B4f 

Third bed divided into two, 4 f. 3 L 

4. Intermediate 49 f 
Fourth bed 1 f. 7 i. 

5. Intermediate 42 f 

Fifth bed 1 f. 3 i. In three layers^ 

6. Intermediate 56/. 
Sixth bed 7 i. 

* Siwfa is the tagoe language of Geoett^ 



▲PPINDIX. (505 



7- Intermediate 56/. again. 
Seventh bed 2 f. 3 i. 

8. Intermediate ^If. 

Eighth bed 2 f. 2 i In three kyera. 

9. Intermediate 98 f. • 
j^inth bed 1 f. 3 L In three layers. 

JIO. /n^ermedioee 35/. 
Tenth bed 1 f. 

11. Intermediate 98 f. 
Eleventh bed 3 f. 3 L . 

12. Intermediate 92 f. 
Twelfth bed If. 2L 

13. Intermediate 91 f. 

Thirteenth bed 1 f. 7 i* In three layers. 

14. Interme^ate 98 f. 

Fourteenth bed 4 f. In two layers. 

15. Intermediate* 

Fifteenth vein 3 f. 3 i. In two layers. 

16. Intermediate^/. 

Sixteenth bed 3 f. In three layers. 
17- Intermediate 49f* 

Seventeenth bed 3 f. In two layers. 
18. Intermediate 91 f. 

Eighteenth bed 1 f. 3 i. In two layers. 
19* Intermediate 87/ 

Nineteenth bed 5 f. 6 i. In two layers. 

20. Intermediate 49 f. 

Twentieth bed 3 f. In two layers. 

21. Intermediate 98/ 

Tw«|ity-first bed 2 f. 3 i. In two layers. . 

22. Intermediate 49 f. 
Twenty-second bed 4 f. In two layers. 

23. Intermediate 98 f. 

Twenty-thiid bed 1 f. 7 i* In three layers. 

24. Intermediate 49 f. 

Twenty«fourth bed 1 f. 2 L In two layers. 



(06 AmvDix. 

35. Intermediate SB f. 

Twenty-fifth bed 1 f. 2 i. In two IsiyaiB. 
86. Intemiediaie 84 f. 

Twenty-sixth bed 3 f. 3 L In two layen. 
87* Intermediate 45/. 

Twenty-seventh bed 8 £ 3 L 

88. Intermediate 42 f. 
Twenty-eigfath bed 8 f. 3 i. 

89. Intermediate's/. 
Twenty-ninth bed 5 f. .7 i* 

30. Intermediate 24 f. 

Thirtieth bed 3 f. In two layers. 

31. Intermediate 49 f. 

Thirty-first bed 2 f. 3 i. In three hyenu 
38. Intermediate 94 f. 

Thirty-second bed 3 £ In two layers. 

33. Intermediate 70 f. 

Thirty-third bed 4 £ 7 i In two hsfm. 

34. Intermediate 42 f. 

Thirty-fourth bed 1 £ 3 L In three \Bjen. 

35. Intermediate 70 f, 

Thirty.fifth bed 3 £ 7 i. 

36. Intermediate 9\ f. * 
Thirty-sixth bed 3 £ 

37. Intermediate Zhf. 

Thirty-seTenth bed 8 £ 7 i. In two kjftn. 

38. Jn^ermedto/e 88/ 
Thirty-eighth bed I £ In two layeig. 

39. Intermediate 14/ 

Thirty^nittth bed 1 £ 5 L IntMlqwct. 

40. Intermediate 42 f. 

Fortieth bed 7 i. 
^ 41. Intermediate 56/ 

FoTty-flrrtbed8£ Si. Intwolejrcnk 
48. Intermediate 42 f. 

Forty-ieoond bed 4 £ 3 L IntwoliVCOk 



Amvoix. 507 



43. IntermediaU 49 f. 
Forty.thirdbedl£7L 

44. Intermediate 67 f. 
Porty-fbuffth bed S f. 

46. Iniermediaie 4^f. 

■prty-fifth bed 9 f. In two kyen^ 
4^. Intermediaie2lf. 

Forty-sixth bed 4 £ In two kyen. 

47. Iktermedkde IMf. 
Forty-eeventh bed 9 £ In two hyen. 

48. IfUermediaie 70 f. 

Forty-eighth bed 7 i 

49. Intermediate 7 /• 
Porty-ninth bed 1 £ 3 i. 

5a IwtemedMOe 70 f. 

Fiftieth bed 4i i 
6X, IrdermedMiteTf* 

Fifty-first bed 1 £ 3 L 

52. Intermediate Shf. 

Fifty-second bed 3 £ In two layers. 

53. Intermediate S4f. 

Fifty-third bed 3 £ In two layers. 

54. Intermediate 70 f* 

Fifty-fourth bed 3 £ 3 i. 

55. Intermediate ^/^ 
Fifty-fifth bed 3 £ 3 L 

56. Intermediate 84/. 

Fifty-sath bed 1 £ 7 i. 

57. Intermed^e 4S0/. 

Fifty-seventh bed 2 £ 7 i. IntwoJayers. 

58. Intermediate 105/. 
Fifty-eighth bed 1 £ 

59. Intermediate 126/. 

Fifty-ninth bed 3 £ 3 L Intwoh^crs. 

60. Intermediate 154/ 
Sixtieth bed l£2i. 



^g APPENDIX. 

61. Intermediate 126/ 

Sixty-first bed 3 f. 8 L In two layers. 

All the intermediate beds are of ai^g^illaoeous or calcareoiu 
stone. These substances also often qipear in the tbickneas 
of the coal beds. Sometimes these beds are divided into two 
or three layers by houage, or black day, and by geantrax^ a 
kind of ampeUte*. 

This enormous mass of coal seems to form a continuation 
of those of Huy> Namur> Anzin, Mons^ Tournay, Vakn- 
ciennea. 



No. v. Strata at Portsoy^ Scotland. 

[From Mr. Jameson's Mineralogy of the ScoUsh Islands, toI. ii. 

p. 270, scqq.] 

" We now continued journeying along hy the sea-shore, 
that "we might have a better opportunity of discovering any 
interesting appearances which were to be observed. The 
clifis continue to Sandside to be composed of nearly vertical 
strata of talcaceous and micaceous schistus; but upon tbe 
south side of Sandside I observed a considerable stratum of 
steel-grey, foliated limestone, which lies upon an ardesia, or 
primitive argillaceous schistus, and this ardesia appears to be 
covered by a breccia. As the sea covered the greater part of 
this rock of breccia, I could not determine with certainty its 
position with regard to the limestone. After passing this 
stratum of limestone, which, we were informed, runs a con- 
siderable way into the country, we came to an immense mass 
of breccia which seemed to be quite insulated : it is not im- 
probable, however, that before the sea had washed away the 
talcaceous schistus, the breccia would have been observed co« 
vering it. We still continued our journey along the shore 
until we came within a quarter of a mile of Portsoy; and in 

* Ampelite, Brongn. i. 561, U slumioous slate and black cKallc. P. 



APniiDix. 609 

that extent I obflermL strata of talcaceous^ micaoeous^ and 
hornblende 8chistus> alternating with each other. We now 
jumlked to the town, which we found to be irregular and 
dirty. 

'^ As the rocks upon the sea^shore near to this town ar^ 
▼ery interesting^ we agreed to stay a day or two> and examine 
them particularly. I was the more anxious to do t^is, as 
they have longitttracted the attention of mineralogists; but 
their particular geognoetic characters have never been de- 
tailed in any publication. After having examined these rocks, 
the following is the result of the observations which I made. 

" About a quarter of a mile from Portsoy, at the place to 
which I had traced the strata in coming into the town, th^ 
talcaoeous schistus appeared in vertical strata ; and nearly at 
the saAae place I observed a stratum of white marble, which 
18 marked £, in the plan at the end of this volume. It is 
about twelve feet wide, and runs south-west and north-east, 
which is in the same direction with the Ixninding strata^. 
It appears to have been worked for ornamental purposes, as 
I observed several blocks upon the beach which seem to have 
been sawed. To this stratum succeeds a vertical stratum of 
micaceous schistus f, marked F, which is compact, and of a 
blackish colour where in contact with the marble, but of a 
green colour where it is in oontact with the next stratum, 
which is serpentine ^. The stratum of serpentine^ marked G, 
which succeeds to the talcacepus schistus, is of .great width, 
and, like the other strata, is nearly veilical, and runs in a 



« • This maible ii white, or clouded wiih steel grey j but it it mvA 
fnth Males qf talc." 

** ^ The talcBceous 'schiitus, which alternates witli these strata, has tome- 
times so much the appearance of compact micaceous schistus, tliat it caimot be 
distinguished from it : and as it approaches the marble, it is to be observed 
mued with it, and passtog into it." 

^ *' X 1*1^1* serpentioe is <if various sliades of olive and blackish green. Its 
fracture, which is either uneven, coarse splintery, or even 6nc spUnterv, presents 
canaiy-green scales. It is intermiiied with various fossils, as asbcstus, Indurated 
4teatites, talcite of WaUeiius, calcareous spar, and iron pyrites.*' 

VOL. It. 2 K , 



610 



sin^kr dimftkm. ltiayBOiillntDtiie«mia»agnfltOTH^ 
and thJB^ wilb its green vdkfoty gMs it u ciagvfar 
Tbis tftntam is boaiiAed byaatmtom 
H> which is almost entirely oompoBed of quartz* where It is 
fncoDAactwithtteserpeatine; tataskappKiaclwitteiKxt 
BlratinEi^ which is naifcle, it has mose of the tijcuoaooi ch»> 
racier, and is also tnKversed by veias of ijuaitx. The^tftmnn 
of inBH>le» I, is from 15 to 90 feet mde; is aiao wettied^ 
hot isof abadiqaalily, and will not aervete -any vmuoRatil 
piHpose. It has, immersed in it^ pieces of qmote and tii^ 
ceoeous sdiistus. To this stratum succeeds a thin atxatnnaf 
quartz; and this again is bounded by a thin slratnm «f tal- 
caoeous schistus, K. Both these strata are only a few ieet 
Wide> and are succeeded by a stratum of marble, L> aeady af 
the same width with the fonner stratum, 1. To this^wirfaie 
succeeds a great stratttn of seipentiae, M, which is of tba 
same natinre with the stratum we have befove described^ 
This stratum is bounded by honAlende ixNdcf, N, sditoh 
forms the rocks that ssrroimd the harbour of Fortsoy, and 
continues beyond it towards a bay, the name of which I da 
not reooHectf. It is traversed in several places l^'mns of 
gnmite, which run in difoent dtrections, and vary hibreaddi 
ttom one to eight or nine feet. At a little distance ibom the 
side of the bay I have just mentioned, another sinttum of 
serpentii^e, maiiced O, makes Its appearance; andtoltagaia 
succeeds tlie hornblende rock, P, which is taversed by veina 
ofgru^te(. 

'' We now walked^Jong the shore by the bottom of this 
%afi and upon its opposite side, in the flaoe of the horn* 



* Qnite the ivrene in the sketch. 

^' f The hombleixle rock is genenllj tchiitase, and fau ■Ti*f^hnff fcdct 
tihrawu mica intermixed with it." 

" X The seipentine, ts it approacfaei the Irarnbleiideiodc, hecenes ptAaSkf 
iDtensiied with it, and at last is not to be dlstii^mihed firoa^it.'' 

" § Betwixt Portsoy liarbour and the bay I observed matfole,:liitt I could not 
determine how it lay, with respect |o the other rodEis to that I latve uaft repic- 
seatadithidieplao.'' 



*•"• 

I 



ff 



UMb iwi^, thote Me npgged (Kft of jnicieMB fcbistiii^ 
which is in some places alternated with quartz, aoid in otherp 
lray«ffM4 by cooai4mdbk granite iwiiw. The micaeeoua schia* 
tui aoawNrignw eonlmg gamete; upd tbe graiute> which id 
gNat-gnined> firequanUsr conbtthis cryntais 4»f acbori and 
niipa* ami MOMtinics it has the appearance that is caltod 
fianrt gr4fhiqii£. 81K1I1 afipean to Joe the 4ifl|io»idon and aar 
tmeof ttefltrataiiqinndiedioreatPaitsof*. ^ 

'' ha Aha gepgnoatie Qharaotevs of Aha aerpentiae at tUi 
place arekxteraatiipg, I diaH here xoeQtiiQin,fin* the infbrmatiooji 
of my nadeis, a far fecta, whfeh abow that pretty neari^ 
aimilar appearances have been obsenred in other countries. 
Zobtenberg> in Lower Silesta^ consists entirely of serpentine, 
Sn which some hon^blen^e is fb^nd, and its strata are nearly 
vertical t. In the Miner's Kalendar for 1790, Kohler in- 
feiyms. i^ that serpentine and primitinie limestone (marfale) 
are nearly allied in their geognostic characters, and t^t 
ao^etin^es jthey are disposed in strata which alternate. We 
are also informed that serpentine rests upon gneiss, and even 
alternates with it J, and also with quartzy talcaceous schistus §. 

'' The appearance of the veins of granite traversing horn* 
Uenda rock aad mkaceous echistw^ is by no means uncom- 
mon in Scotknd 3 and in other countries similar appearances 
have been «ery often observed. The piarre grapldque has 
been observed in Siberia to form the sides of veins where the 
topaz is found II ; but at Sebritz it is disposed in beds with 
the comaion granite f; and in the Uralian mouotains Her- 
man observed it mixed with the common granite **. Fktrin, 
who found it in Siberia with the topaz> ooi^tures that it 



^ * Some tnvcHen are of opinion that the Mtpentine and OMible (bm gmt 
«otn«» ndier than vertical ttimta." 
«.t A Bad. JWobacht. SAa." 

<« { X:i^iIKMkff Minan^giicha Qaqgraii^ von a«oic^^ 

** % N. Nofd. Beytnge. 149." 

II Jour, de Phjaiqtie. Ann. 1791* 

\ N. Beigmannbhe'i Joornal, B. 9. 446. 

A*i|eniMMiMineiBlogiteheBeMhreUmiigdet'Ufdaischeii<>ibaifn»B.l. 144. 

8 R 8 



012 



AFPENDIX. 

may generally be considered as indicatiTe of the presence of 
these gems. 

'' Having thus examined the strata upon the shores I 
walked into the country for about two miles, but could oh* 
serve no trace of the serpentine, or marble, or talcaoeooi 
schistus \ but in several places I observed the hornblende rock. 
I ascended a hill a few hundred feet hi^ ; upon the side of 
it were masses of hornblende rock and gneiss scattered about^ 
but towards the summit it was entirely composed of sdustose 
quartz. This is a rare rock in Scotland; nor has it bee* 
observed but in a veiy few places upon the Continent.*' 



isd 







• 
















M 


fa 


o 


» 


■" 


1^ 


s 


z 





^ 



*. 



No. VI. Further iUustrations of Miagite and NioHi^* 

[Translated from Fai^, Ettai de Geologie, Fwb 1809, 

tome ii. p. d/Q.] 



ORBICULAR GRANITE OF CORSICA ; 
Ducovery qfthe Site qfthis Stone. 

In 1785 was discovered in Corsica* on a small eminence 
with a level summit in the plain of Taravo^ an insulated and 
rounded, but at the same time unparalleled block of rare and 
extraordinary granite with globular crystallisations, whkh 
deeply excited the curiosity of naturalists. 

If, on the one hand, this discovery was interesting;, to mi- 
nerak^;istsi on the other, geobgists readily comprehended 



APPENDIX. 613 

that an insulated block of stone, the ofgankation of which 
posBessed a character so forcibly pronounced and so ^^SereaC 
to that of other rocks, might, if the spot where it was found 
were diBcovered, point out the distance it had traversed firom 
its natiye place to that whither it was removed in the shape 
<^ a rounded block. 

Messieurs ds Sionville, Barral, Dolomieu, and other natu^ 
ralists after them, made long and vain researches to discover 
the orlMcular g^ranite in its original situation. The search 
for it seemed to be abandoned, and specimens of the first 
block, dispersed in cabinets, became every day more and 
more rare; and when any pieces of it were exposed to sale, * 
they obtained very considerable prices. 

In the month of May 1809, that is to say, twenty-four 
years afterwards, M. Mathieu, a captain of artillery resident 
in Corsica, distinguished alike for his military talents and 
his taste for the study of nature, while traversing the steep 
granitic mountain by the side of the village of Sainie Lucie, 
seven leagues distant from the spot where the first block was 
found, observed attentively a saliant mass of rock, entirely 
covered vrith lichens and moss, which concealed its external 
character j but the interior texture of the stone being acci*- 
dentally displayed by a break in it, M. Mathieu was agreeably 
aurprised to find that the whole mass consisted of orbicular 
granite, similar in composition, colour, and mode qf forma- 
tion, to the orbicular granite which had so long and fruit- 
lessly been sought: other masses, contiguous one to the 
other, and in a similar manner covered with lichens and old 
moss, occasioning a presumption that they might be of lik^ 
nature, M. Mathieu tried then^ with his hammer, and dis- 
covered them to be actually the same species of orbicular 
granite. It was about three parts up the mountain, and on 
ground belonging to M. Jean Paul Roccasserra, that this dis- 
covery was made. 

As the point the most essential to geology here b to ascer« 
tain distinctly the spot where this granite lies, that no doubt 
may be entertained of its adherence to the rock on which it 



A 



614 AfftHMH. 

iMtf ibrmetf ^ it U incmstetf, hAf ^ etudditfe this ouAte^, im 
kaow ihKt the mmiitaiii of Suhue Imeie is gtocrldly oook 
}idMd of A greyish grtldite^ eoBsistifig olqourts, fel^iiry aai 
ttto; nidfhAtithssanelefatk>iiofalNnitd)afeet*« 

Let M suppose tht observer to be filaeed en the snnanlt of 
the inoantain> where blocks and masses of gref granite fie 
httrei som^ of them seMsitft and afiected in a sl%ht degrte by 
time; from this point he is presumed to tAe liis deportiire^ 
dsif he would descend by tlieside of tiie moonti^ which q^ 
pait^ntly slopes towatds the villagis of 9ainie Lueie. 

His way then lies over the same kind of granitic rock nalfl 
M) feet bek>w tiie summit whence he departed, m c asmiMg - 
perpendicularly j in the rock he padses oteo^ there is nothing 
hut quartz, fyspar> And mica withovt hornblende. When 
Ift this distance below the summit he will notice a change in 
the rock, which insensibly passes to the stai^ of homfalinda 
tock of rather a greenish black colour, mixed with muek 
White felspar^ compact, but in a sl^ht degree granulated^ 
and somewhat similar to antique black and white granite of 
k fine grain. 

As the observer advances over this difiefing ikpaee he wfll 
begin to perceive the first attempts at globolat crystallisatioii 
in the solid rock; shortly after he will discover a pretty 
huge mass, hairier than the mother rocki which rises to a 
certain height^ but at its base adlieres to the hombleBde 
rock below. This first block presents globules of diieieni 
sizes, the spherical form of which is advanced to a more pei^ 
feet and n^ar state than in the crystallisations previoud^ 
noticed. 

Finally, at but little dbtance from tUs first mass of ghibiH 



* These iratmctive dehah 1 liftve from M. Matfaieu Umself, wbom I 
die pbiiuic of Mcfaig at I^ris, on hit wnj to HoIIan<), whither he wtt going bf 
Older of the minUtcr. He was kind enough to commanicate to me the poaitioa 
of die mount^n of SahiU Lude^ to draw a dcvtch of it, and to mark the placet 
where the globular granite is »ititate; and at liis request it is, and with his pcr^ 
misnoD, that 1 publish this account, to serve as a supplemeoi to what I hivt 
laid of the orbiciilar gruiite of the plain of Taiaro. 



I 

APPVNDIS. 615 

Imt gfmntit, olhen tie fbnod of skiiBar sature* man or kat 
m^iamtt but tke awriMr of them k not gicat. M. Malhiea 
fan^niy then to be a apedes of kemek much mof solid 
theft the honibleiMle rock which geve them birth $ end thel 
thk, aot being of a conqpositioa equally hard, haebeeQ unable 
in aft equal degree to leeiat the action of the weather> and 
eonsequently^ beeoatuag graduaUj deoompoeed ia part, hae 
left the orbkolar granite bare. 

The spaoe oGcupied by these nnguhur prodoctiona, at leaat 
audi of them aa ase exposed to sight, indudiag that filled l^ 
the hornblende rock> ia about a hundred yards j after which 
the orcKnary granite reappears. 

M. Mathieo, not content with simply affording me Ia- 
atiuedve infiprmation respecting the diioQfvery he bad madaj 
waa ao kind and liberal aa to enrich mj collection with a 
aeriea of beautiful specimens of all the varieties of brbioukr 
granite he had collected on the mountain of Sainte Lade. 

I here annex a short description of tlioae which appeared 
to me the most interesting. 

' No. 1. A specimen, the thickness of whidi is one inch and 
three lines, dfameter four inches, of orbicular granite, re- 
sembling as weU in composition, shade of colour, and hard* 
ntaa, aa in the form of ita globules, that of Taravo, possessing 
alsn like that some small brilliant points of a substance 
apparently metallic, and of a silvery white colour, which 
alfects the magnet, and bdonga to the class of magnetic 
pyrites. This substance takes a beautiful polish; grains of 
this description are not numerous, but distinctly sprinkled 
in the mass, as wdl as in the globules themsdves of this 
granite. In every respect, in short, it seems a similar species 
to that of the valley of Taraoo ; but M. Mathieu informed 
me that this beautifiil variety is not frequent: it eziata, how 
ever, in its original site, which suffices. 

No 3. Orbicular granite, the composition of which ia 
the same with that of the granite of the plain of Taruvo, but 



gl5 ' ArPBiroiz. 

the globules of whichi of much greater tise, are almost en* ' 
tirely white, owing to the predominance of the felspar of 
that colour, and' the almost total absence of hornblende, of 
which only very slight traces can be distinguished. White 
globules,' like those on the black ground spotted with white, 
of which this granite is composed, produce an effect as re- ' 
markable as it is extraordinary. The arts might reap great 
advantage from it in the formation of certain monuments ;' 
which would be the more attractive of notice as the Greeks 
and Romans, so solicitous of employing the most curious 
granites, never knew this species. As^ according to M. Ma- 
thieu, the largest blocks are of this variety, they would con- 
sequently furnish the most considerable nouisses $ in order to 
transport them, all that would be required is the making a 
road practicable for carriages, from Mount Sainte Lucie to 
the Crulf of Valinco. 

Some laminae of mica, of a bright brown, are seen in small 
patches, in certain parts of this granite. 

Nd. 3. Another variety, remarkable on account of the 
ground of the stone, which is of much deeper colour, owing 
to the greater abundance of hornblende, and to its particles 
being more divided, and more equally mixed with the granu- 
lated fekpar, which has received a tint from it of greenish ' 
black, that gives the stone, which is hard and receives a very 
beautiful polish, rather a grave appearance. The globules in 
general ar# of inferior size, and distinctly marked, and the 
lightly greeitish tint which shades their white circles harmo- 
nises with the ground of the stone. 

No. 4. I know not whether or not we ouglit to consid^ as 
a fourth variety that in* which the globules are of equal size 
with those in the preceding, but in which the ground is dif- 
ferent ; being more rich in felspar than in hornblende, and 
speckled with white and black in a very distinct manner 
and without being mixed, so that the white specks predomi- 
natingi the ground^ fiir from being so harsh as in the pre* 



APPBVDtX. 617 

% in lively; what indeed renden this ipedmen still 
more pleasing, the globules, being tinged with an extremely, 
light but evident shade of black, have acquired by the mix* 
ture a bluish appearance, highly grateful to the eye. 

No. 5. Finally, one of the most remarkable varieties of the. 
orbicular granite discovered by M. Mathieu, and at the same 
time the most clearly distinct as k variety, is that which, on 
neaiiy a black and equal ground, resulting fiom a uniform 
mixture of white felspar and black hornblende in particles, is 
distinguished by its globjiles having in general the first circle 
white. As black is the dominant colour in this singular 
variety of orbicular granite, the white circles which succeed^ * 

and are alternated with black, participate of this tint, and 
are, as it were, veiled with black ; they are, however, very 
distinct, owing to their contrastinewith the other circles, 
wlfich are of the deepest black. Tflk variety, which takes a 
polish equally beautiful with the other specimens, and is H>r 

equally hard, is {bund in tolerably large masses. It is ad- Q 

mirably ^pted ibr urns, and other vases of a grave aspect. 

Such are the principal varieties of the orbicular granite^ 
for the discovery of which we are indebted to M. Mathieu. ^ 
I have'thought right to give these details at length, the bet- 
ter to delineate a rock of which nature has been so little pro- 
digal. I reserve all the fects, that I may resume them when« 
if I am able, I may occupy myself with the theory of this 
stone ; for if it be clearly demonstrated, as every thing seems 
to show, that this is the native site from which the block of 
Taravo was torn, an exact datum will be afforded of a very 
singular geological fact. 



GLOBULAR PORPHYRY OF CORSICA ; 

ft 

bs dispontion in large weins. 
It was reserved for M. Mathieu to find on its natal spot. 



mot cmlfthe orbictlar gnadtie^ Imt atoi> gbbiilsr for^^tfry, 
two of thtf flwrt beaiitiM stcnoes knovm to afoenio^^ 
- I lUkdl beftwie heard fhm M. Dupeynt, efalef eagiiieer dbr 
jMm/« ^ chmmea in ConHCii» a very good mtaralkt, tiat M. 
Mathieu, a captain of ardUery^ had discovered large mnwif 
of globiriar porphyry on tl^ site. HL Dopeyrat was so 
good even as to give me a harndsome specimen of tfaia stose 
ftotn M. Mathoeit; but I uras yet withoiit the nccesaary in* 
ftirmalkn retpecting the spot ivhere it wbs fimad> to be ahls 
to speak of it fvith certainty, when M. Mathieo, mukr ortea 
to join the army in Holland, came to Puis, vi^ere I had the 
piotfure of seeing him, and receiving some very iastmctiva 
details, acconqNAied by plans and drawings, and a serin of 
very fine specieoens of aH the varieties of giobokr porphyry, 
Vfith which he was so obfiging as to enrich my oolfection. 

My book was wholly nrinted^ but the publication was de* 
layed by the engravinpFaot being yet entirely coaspleted; 
''' ^ this delay aOowed of fdj inserting the present account, aa 

wen as that I have previously given of brhicular granite : the 
learned among naturalists will be the better pleased with me 
for producing it, as the basis of the account is derived from 
M. Mathien himself. 

' It is fit however that I should observe, before I proceed 
farther, that a specimen of globular porphyiy, nearly twenty 
years back, was added to the collection of the beautiful odM* 
net of natural history in the HoUl de Monnaie at Pari$» 
ibnned by M. Sage, founder of the first School of Biines, a 
ticket to which states that it came from Gaieria, in Cloracai 
hut whether thb single specimen wholly esca^d the notice 
of mineralogists ; whether it was regarded merely as a sort 
of solid geod, formed accidentally in the composition which 
serves it as a gangi this species of stone was no longer 
spoken of, and no specimens of it were found in other ca* 
binets. 

In the month of January, ISM, M. Rampasse, a veteran 
officer of Corsican light in&ntry, &voured me vrith informa- 
tion from fiastia that, in a mineralogical excursion into the 



id^imtaiiit of grkdte in seaich of ^MeaikKt gru^te, in wMek 
0ean:h lie was tuxsuccessM, he had in scmie measore been in* 
diMinified lyy the diBcoveiy^ on the flanlc of a mountain oo^ 
-weteA with wood, between Monte Pettusato and the valley 
wliieh leads to Santa Maoia la Stella, of '^ u block of stone* • 
lour feet and a half in length hj three in breadth^ which wail 
aonk in the earth, and displgyed on one of its sides giobidar 
ixi^ea remarkable fbr their disposition and colour/'^ M.^- 
Rampasse added, that he was unable to sunder more thtiB^ 
about eighty pounds weight from the stone, and that he con« 
aidered it a proper i^pendage to the orbicular gnmite. Some 
time after M. Rampasse came to Paris, and the specimens of 
gLobolar porphyry which he brought with him strongly tx* 
cited the attention of naturalists. 

It was not then generally known, and I myself was at thai 
time ignorant, that M. Mathien had discovered, twelve months 
faefbre, orbieular porphyry on its native site, not only in 
koge masses, but in a kind. of veins, very thick and of oonsi* 
detable eiitent, and that he had already sent to Fsrii two 
memoirs on the occasion, accompanied by plans and charts, 
the one intended fot presentation to the Institute of Fra^nce, 
the other addressed to M. Vialart-Saint-Morys, who resides 
on one of his estates at Houdamville, in the neighbourlMKHl 
of Clermont, in the department of the Oise i this latter was 
also accompanied by several specimens of the stone, iriiich, 
with the memoir^ were contained in a case that had not yet 
been opened, and which M. de Ssdnt Morys was requested by 
M. Mathieu, on his passing through Pkris, to deliver into my 
hands. From this memoir I propose to designate the site oi 
the globular porphyry found by M. Mathieu, in a different 
spot from that in which M. Rampasse diKovered his insulated 
block pertly buried in the earth. 

^' The territory on which the globular porphyry is found,*' 
says M. Mathieu, in a memoir sent to M. Vialart-Sednt-MorySj 

* Sm the letter of M. lUmpaste, insenaS Tome vtU, pa^ 470, of the 
Amtdif iu Mitsaim dSistairt iVolwtNr, 



630 MnBVDVL. 

and which I have at this time before TXle, ''is bmmded on the' 
aoiith by the Bussagia, and on the north by the Munolino; it 
comprifles the district oi'Ozani, and that of Girolaia, whicli 
collectively have an extent of about eight leagues and a half 
• square. The aspect of the country is extremely rugged ancl 
wild, especially in the district of Girolata: nothing is seen 
but steep and arid mountainsj the most elevated' of which 
' form a line from east to west ; these are accompanied by other 
jjunall chains less lofty^ resembling teats, which become gra^ 
dually of less height as they advance in amphitheatrical dis- 
position to the sea, when they terminate in almost inaccessible 
clifis. The whole of this mountainous district is composed of 
porphyrons rocks of dififerent species, varying from each other 
in colour, in the disposition of their constituent parts, in 
degree of hardness, and the difierent state of oxydation of 
the iron which generally predominates in them. 

*' These rocks are furrowed by long and large veins, some 
of them more than sixteen feet in thickness, and of consider- 
able extent. As these consist of a porphyry of greater hard- 
ness than that which forms their bed, and which has under- 
gone a change from time, they rescgcnble large walls raised by 
the hand of man. Many of these veins have globules in 
them, varying in siae and intensity of colour; and as these 
kinds of walls are sometimes very wide apart, they present 
distii^tions and a great variety in their form, and the dispo- 
sition and shade of the colour of their globules. The vein of 
the village Ckarzo is greyish; in this the globules are very 
laige and of a somewhat rosy colour; while at Girolata the 
ground is a blood red, and the globules of a less deep colour. 
At a short distance from this last spot is seen a vein, the 
globules of which are not larger than peas. The largest glo- 
bules are found on two peaks of a sugar^oaf form : these 
dhow themselves distinctly, and contrast perfectly with the 
ground of the porphyry; they are three inches in diameter> 
and most commonly four. 

'' At La Bocca Vignola the ^hole sur&ce of the soU is co- 
vered with small balls in a state of decomposition; at L^ 



Bocca CfaUria the febpar, harder and of a deeper colour than 
any where else, contains globules of a paler hue ; there also; 
are found most beautiful geods of a substance much more 
indurated, which seem as if agatised, anil^re of a reddish 
brown colour; at Fornaci the same kind of geods, but of a 
tlolet tint: these last are yerj bulky, some of them being 
more than a foot and a half in diameter. 

" At Elbo, on the sea-shore, globules are found dettiched 
item theur matrices, forming a sort of insulated balls. It 
appeaxB that the action of the waves has been sufficiently 
forcible to beat down, break, and wear away, blocks of the 
porphyry } but that the globules being much more hard, have 
BK)re strongly resisted degradation, and been cast on shore. 

*' To conclude : this vast extent is entirely composed of 
porphyrous socks, intersected by numerous reins in the form 
of walls, in which the globular system is every where mani« 
nested; and this wide field for observation well deserves the 
attention of skilful mineralogists, who could not £Biil of 
mflking^ numerous discoveries." 

It now remains I should give a detail of the different 
specimens of orbicular porphyry, presented to me by M, 
Mathieu. 

Noupft. Porphyry of an Isabella colour, with a very %ht 
shade of the rose, the globules spherical, very small and ra- 
diant, some of them encurcled by a distinct line, others with- 
out this distinct line, and united with the ground in such 
manner as to seem to form but one body with their matrix. 
The ground, which is felspar, very compact, and formed of 
extremely small particles, receives an excellent polish, for it 
is hard, but susceptible at the same time of decomposition, as 
well from the oxydation of the iron it contains, as from other 
causes. The largest globules of this porphyry are but four 
lines in diameter, the smallest in general three. When this 
atone is broken for the purpose of obtaining specimens, the 
globules sometimes separate in a perfect state, and leave the 
mark of their position in the stone. 



(^ Arr*iiD» 



▼ariaty of porphyiy mUdk smidl globulet feqidreB tint 
detail gWen of it, on acooupt of its ■ffoowfanyipg general^ 
tbe porfd^ry with large globukB, nvbkb Fe are about ^ 
PKDtioD i or, m^ prc^ieriy i^yaking, tliw is the rotdc itoU^ 
in ipidst of whidi tfce latter is most oc^mnapfy fimiad in Ik^ 
•bape of tWck walls which icseaiUe vijas, and wU^ nbair 
themselves in this manner only on ^«y»ui»t of tfim fcavji^ 
cvpposed a greater reaistanoe to decQoapoaiitioa than thtt snr- 
rounding Koek with aiwill globides. 'Bus gQck> Sffor^ fAmmdt 
ing in felspai*, and of more bwapnogeaoija ^exjhirek 14, }ikia«ll 
felspar, subject to a species of Apontaneous deOTWpwatii^ja^ 
especially if iion, so prone, to o^dalj^au be ftmnd m jfo 
either united or an combinatioxi, in too great n f^^pvHim^ 
The walls of globular porphyry bax^e evei^ mfifp iseadlly be* 
(K>me exposedj when th^ bave chwaoed lo be.siirnHwde^ bf 
rocks of a greenish granulated porphyry, laf a-qnor^ fcwylini 
nature, and sintilar to those found at ObevstoUii in iht 
SsterellenKmntain; and in general inmpstcoimiUieayieldbgc 
porphyiy. 

No. 2. Spherical globules, two inches in diameterj thf 
smallest being of two inches wanting three lines^ Jyillg jji 
their gang, to which they closely adhere. 

This gang is compact felspar, speckled withanochr||pR^ of 
different shades, with sipall spots of a blackish brow^, ^o^ 
f^m be .considered, as well from its position as jMm its qior 
cial mode of formation^ as no other than a porphyroi^* |«4 
not a ja^io'id, for Ks parts are fusible under the blQw-|iipa. 
<)b8^rying the small red spots through a micrpscopej 4mi^ 
sees distinctly that they arje formed only by iimper{eet<cryq|al* 
lisations of a globular figure. The ground, of a btockisb 
brown, on which these ^liminutive globules, inanimperftejt 
state and of a reddish oolpur, f4>pear, has this tint friaia the 
iron* on Hs ojiydation, assiwing a bla<;kish colo^r^ whemi 
ifi the globules the o^cyd of the irpn is red; but a^l^ethiy 
there be a somewhat greater proportion of quarts^ pftrtjclsp 
in the small blackish spots than in tbose v^biflh mir^ mi^, it .is 



688 

a fut€tmtiktifaks ani die lineaaieotB txf a blaekkh tint im 

liankr in m oertaiQ degveeiliaii tiiofle ivtiich are red; this 10 

snaflt eviileat after the atone hm been tubmitted to a poltah, 

and is exposed to a fiiToiurable light The black fiarts aie 

Ibenaeen to iie i%h% salbttt^ and to exhibit^ notwitibstaad- 

ingthe vihole stone racelves a beautifal polish, a glossineflp |^ 

more lively and mors brilliant than the rest of it. 

The globules enclosed in this porphyry are of a flesh coloiir 
iRBryiBgin sliade, with radii divergis^ fnun the centre to the 
giroiB n ferepoe, traced by Unes of a oioie evident coloor than 
tliei'est of tiiegk>bale» and rather Uaekishj these lines kra^ 
disEte hook a kernd in the centre, of a uniform but more red 
eak»r tfam tiie rest of the f lobule. A braad drcidtt line, 
almoat white, «r but ^fedntly tinged iwth red> surrounds each * 
globule, and determines the circumference. But, in order to 
nbtnin all these results in the beat manner, on sawing the 
specimens care should be taken to divide each ball as neai4y 
as possible in the centre, so that the kernel may appear : the 
ImJIs thus cut take an exquisite polish^ which exhibits in a 
l^lflin manner the efl^ct cf this singular system of globular 
crystdlisation. 

No.S. A perfect^ spherical baU, accidentally separated &om 
the rock; it is three inches and six lines in diameter; a 
elfoie ft«e lines tMToad, and uniform in its breadth, surrounds 
^kt exterior of the ball, which is composed of a kind of ban) 
Mspar, analogous to that of the matrix, but of which tiie 
points, of a reddish colour, are very small All these present 
toaperfeot cxyataUisations in small compact divergent rays. 

A second ^rde, two lines and a half in breadth, of com* 
pact Mspar of a fown-coloured white, is enclosed within 
the sorteroal circle, and the rest of the ball is only an assem* 
Uage jof cryatab of compact felspar of a somewhat deeper 
liot» which dfareot to a common centre: I had this separated 
ball cut into two equal parts* 

No. 4« In a beautiftil specimen composed of three large 



% 



- ^ 



f 

•624 APPEvrnx. 

globules, very sound, and perfect in their gangait^ a singular 
accident is seen to have taken place, the discovery of which 
is owing to mere chance. Having caused this specimen to be 
cut, in order to be enabled to place it in my drawers, it was 
divided into two equal parts, and the operation exposed a 
globule two inches and three lines in diameter, a piece of 
which had at some former time been separated from it by a 
motion of the rock, but was again knitted to the stock in 
such a perfect manner that the joint was scarcely perceptible. 
This section of the globule forms a kind of crescent one inch 
seven lines in length, which is out of its place as if repubed 
from the circle, but in such manner that one might fancy 
it would assume its ancient disposition ; notwithstanding^ 
which, I must repeat, it is difficult to distinguish the points 
of connexion. 

This specimen, before it was cut^ was presented to me bj 
M. Rampasse. 

No. 5. An elongated oval globule, of great regularity in 
its colours ; in breadth one inch nine lines, in length fbor 
inches two lines : it is to be presumed this elongated fbnn is 
owing to the union of several globules at the period of their 

m 

crystallisation, which thus became confounded in one oval ; 
a line of red felspar fills the whole length of the greater 
diameter, and the crystals divei^ from this point, which 
serves as their common centre: this specimen, highly re- 
markable on account of its shape, has a kind of regularity in 
all its parts. 

To conclude, the lai^ blocks of a stone so singular and so 
hard as this, were they vtnnrked for the purpose of introduciiig 
them to the arts, whether in making of columns, tables, or 
, socles, would present pieces equally remarkable for the na* 
turc of the stone itself, as for variety, size, the colour* 
and form of the globules* which render it so much an otitject 
of curiosity. 



Afpimix* 025 



i 

No. VTI* Reineggs on tM Mineralogy of the Archie- 

pelago. 

• • • 

[Scdta di opuscoli interassanti/ Milan XiTJ, 8vo. trol. xxxii.*} 

» < 

The mountains of btrm are connected witlr tbose of Cb> 
niola and Stiria, of k tnoderate height, but rather predpilous; 
They entirely eonjtst of limestone; with a prddigfibufl quan^ 
tity of nummoUtes. • BtAtues haVel^een^fbrmedctf %;^' whic& 
the sheila prodoce the efibct of xAii^B 'ot the small'iMix. Hw 
strata are strangely varied, soM^fitties horizontal, sometimes 
vertical. They are mostly clothed with olives and vines. 

Further on is fonned a 'siliceous sandstone, which af^er- 
wards changes for white- Imestone, which contimies to the 
tt^hboi]i>h6bd of Ragusa. 

- The moulMins of Dalmatm are of the same kind, being 
mcistiy conipod'ed of a compact limestone, capable of polish. 
' ifear Oittaaro appears a kind of >gneis8 among the fissures 
of the limestone. Towards Scutari the mountains are gra* 
iiite. The Piisha presented to 'Mm some mfd&ls of iron, 
which he says may be as ancient as the time of Ljcurgus f- ' 

Hie cbsin of mounttdns of Eplnis Continues into Avdadia, 
liliere the smnimits are very hig^. ' 

• Most Of the isles, as Gefirionia 4ir etamplt, have a high 
mountain in the middle, which graduall) lovrers towards the 
sea. Biylo presents warm sulphureous waters. Some of the 
MDs of this isle are calcareous, others of a brown marly clay. 
There is also found a fine taleaoeoos earth. The subterranean 
fires^ mentioned by Tournefort, no longer exist ; but there 
are vestiges of volcanoes foivai^ the nordi, where the hills 
ttre granitic, with baealt attil vitrifications* Thcve is a hfll 



* Tbis paper being thoit) and little kbotro, h was thought proper to pre* 
att^e* it bere* 

. ^ Ihii it tnly aiagtiltf ^ ai aiiek neddi have alwaya Ibmed a dtMsiatian 
-la .-cabioett, and we eaa haidljenapect % minenlogiat of miatalui^ the metak 

VOL. II. 8 8 



of a land of pumioe» which is so hard as to form 

but of a very bad £ort^ and the -chief cause of the ^fd braad 

which is eat in all the Archipelago. 

Of Fbuxis^ though celebrated for its marble, the high hilla 
ai» of granite i but day-slate also appears in the Ticinity of 
the marble. 

. MinoBi is: cUeflyofgnnitA and basalt There are cunoita 
pf v<ta«M(6rgla0^ 4^omone to Anuteea ipfhe^ in breadth> m 
thegnuiite^whicl^isfflsointorspenedwilhb^t. Towanfe 
Jte'sowth A iorater appeal? fiM of volcquuc glass^ basah* and 
9mmj Jkinds of sUma iwUch. l^ive evidently 4nidergone tho 
•Qtienqffir&. Towards tb»pil9:( is deoi^riedgiamtiv and ihAi« 
is nq JMok; of lin^tonei . . ' ; . 
. ^o M oae of the nost beafit^fMl of tb^ Qr^ek isles^ «nd 
tile ^eopil^ -the most ai^iable av^ a^nteUiftei^t; lo.^torre^li 
are found many kinds of granite, Jaspeiv !«gpU#».. camelaani 
^uBrtZ|(«od oalcareoos spavr.* Tl^re ersi fJ^oi^mokueit nqpes 
of sliver f and irame volcanic ^^ppearanc^ L 3fii^ >» frmcivif 
Ibr41# eultttiiaof maatiicj i^uMJ ^ jpopulaj^ff^^y; OOTpiitfid at 
WEly^bousand. . .-v ;. 

f^ JiiMs of Mitilsma.five Aoa»etiBiBs w^oiily^jcospposed of 
pme Mhd white fnmioe^ wbil» others efe granitic^ fnd th^ 
l^tiMfeer pact ca)eamiU0« The nQuatBin oaUed Kasais wholly 
composed of firagments of .ba^^^ qut^iz, and ^ black sto^ 
wldch aoiKn. »' ti»p of tl^e OagflMWP united liy aoegient wtnch 
is hidf cakaaed. 

Near fittyrpa the iMghest sKHPntains vm of grv^i*^ Qap 
hillai^pearsiiplitiatwoMvesj ofwtfkhonei.wbkftiasqnh 
taled to the dIptawM of '«boatr;KM> pace^ to. alt jbiokenin 
.piMea. The iateraal fiswres of ^ihe aapuiiitaiB isve fiUad aitt^ 
a White MBi>iiatoj«e> like the ttarMe of Paw»> wMA peae^i^ 
llie ^mnile in emvy dnenMop^ ia vefais fton ^ne iq<Dh to Ijp 
paces in breadth. Here> and at Faroe, the marble is sepa*^ 
rated ftom the granite by a l^yer of green mk»-slate. The 
calcareous hills about Smyrna may often be distioguishfd 
ikiMBtlieigraBitiehybeiii^ttmrliBU^ aad yMdiag a boHow 
amtnd uader tiie ftet Bounaiiit-^ U» ftfaest part of Hm 



terrltoiy of Smynuij ptesente many ancient colniiini of ba^ 
adt and granite ; but in the mo^^ the Turks, fron supers 
stition^ coloor them green Or red. About live mike* fivfa 
^mjfma 10 a place caUed Neraphis, where there ar^ mines of 
lead which yield silter^ tbe hiUi beii^ traversed by reins of 



No. VUL AecouMt of 9ome Roch in the 9outk of 

Hindostanf. 

" In asoendit^ the Gfaats, I had an excellent opportunity of 
observing the strata^ where the rock had been cut away to 
Ibrm the road. The grand component part of these moun* 
tains is a granite, consisting of white fefepar and quivtz, with 
dark green mk»k in a small proportion to the other two in- 
gredients. llie particWe we aagu]lar> and of moderate sizei 
It seems to come near to the granitelb of the Jtaliaitf ( Wal- 
ler. Min. iL p. 49$)» and w afneaecelknt material Ibr buildings 
a» it is readily cleft by wedges, aind b at the aame timestit>ng 
and durable. Intermixed with this is another stone» in a 
state of decay, consbting of angular masses of various sizes, 
divided by fissures, so as to be separable with little difficulty. 
The sides of the fissures are tarnished, and covered by extra- 
neous matter. This is a stone commonly called a granite in 
decay, the mica being supposed to have been entirely decom- 
posed, and the felspar to be in the act of decomposition, and 
f o have assumed an arid powdery appearance, while the glassy 
quartz retains its natural consistence. That the strata in 
question ai'c in a state of decay, from the numerous fissures 
in them, I have no doubt 5 but there are other strata of simi- 
lar component parts common all over the lower Camatic, 
especially at Mahabdipura (the seven Pagodas], which are in 
the most perfect state of preservation, without the smallest 

* German miles? 

t PiMbB«cbsaan's Tnrels, 9f6k. 4w. 

S S S 



maik of dtcky, and fit for fdrming the most durable bidld* 
ings. Mr. Fichtel, who has been so kind as to kwk over my 
apedmens, and to assist me with his opinion concerning their 
nature, thinks that the stone of Mahabaiipura consists of a. 
mixture of arid and of fitt quarts j and although lie calk the 
atone of the Ghais granite, I have no doubt of its component 
parts being the same with those of the Mahidialipura stone. 

" Both these rocks appear to be stratified; but the strata 
are wonderfully broken and conftised. In some places they 
are almost horizontal, in cihsrs they are vertical, with all 
intermediate degrees of inclination. Sometimes the decaying 
stratum lies above the perfect, and at other times is covered 
by it I saw many strata not above three feet wide ; while 
in other masses of eight or ten feet high^ and many long, I 
oouM perceive no division. 

'' Immersed in both kinds I observed many nodules, as 
largo as the head, which were composed of a decaying sub« 
stance containing much green mica. In other places ther^ 
are lai^ veins, and beds, containing small rhomboklal masses, 
of what Mr. Ftehtdtakestobeacompositionof asmallpro- 
portioii of quartz with much iron.*' * 

Of the hills near Caoefy, 

m 

'' The strata on these hilb are various. I saw red granitic 
porphyry, and took specimens of a fine-grained gneiss, con- 
sistiog of pale red felspar, white quartz, and black mica« 
Tlie most common rock, however, is the hornblende slate 
with quartz, which I have before mentioned. When exposed 
to the air in large high masses, so as to prevent the water 
from lodging on it, the pieces decay into fragments of a 
rhomboidal form; but when exposed to the air on a level 
with the ground, so as to.be penetrated by the rain water, it 
divides into thin laminse, like common sch]stus.''f 

• VoL i. ^ ar, t Vc4. i. p« 5f . 



AfPSMDOL 629 

, '' The stones that are employed in buiUing the temples at 
Md^a^ are : 

'* 1. The granitic porphyry, or the granite which contains 
laige masses of red felspar in a small-grained mixture of grey 
quartz and black mica, which I described at Rdaut-gvri. Near 
Sqvanadurga there is an excellent quarry of this stone. 

" 3. A granite, consisting chiefly of black mica and red 
fpbpar. This may be procured of a very laige size. 

"3. The common grey granite of the country. 
' ^' I met also with, the two following stones ; 
1 " 1. A granite with large grains, black and white. This 
may be procured of great size. 

" 2. A most ornamental BggregBLted rock. The basis is 
green, of what nature I am uncertain; perhaps it may be a 
homstone. It contuns veins of white quartz, and concretions 
of red felspar. The whole takes an elegant polish, and may« 
in Mr. Kirwan's acceptation of the word, be considered as a 
porphyry. Near the surfece the rock is full of rents; but l^ 
digging deep, it is said laige masses may be procured. It 
seems to differ from the fine green stone which was feund in 
the palace at Seringapatam« only by containiiig felspar.** * 

Quarry of black stone, 

" This quarry is situated about half a mile east Amn the 
village t, and rises in a small ridge about half a mile long, 
100 yards wide, and from 520 to 50 feet in perpendicular 
height. This ridge runs nearly north and south, in the com- 
anon directkin of the strata of the countiy, and is surrounded 
on atl sides by the common grey granite, which, as usual, is 
penetrated in all directions by veins of quartz and felspar^ 
but neither of these enter the quarry. 

'^ This stone is called CanciMu, or bbck stone, by the na« 
tiircs, who give the same iq[^llati<m to the quartz imprcg* 
nated with iron, and to the brown hematites^ and in feet 

• VcO. i. p. ISS. t GMMidly. 



6S0 AtreiroiaL 

iAnej dl tun vtrj mudi into one mother, aaddiffsr diiifly in 
the various proportions of the same component puis ; but 
bave a certain general similitude easily defined, and are found 
in similar masses and strata. The blaok-stone of this place 
is an am<M7bous hornblende, containing minute but distinct 
rhomboidai lamellar concretions of besaltin*. I imagine 
that it is the same stone with that wiiidh by the ancients was 
called basaUei, and which was by them tometimes Ibnned 
into images, as it is now by the idolaters of India. 

" The surface of the ri^ is covered with large irregular 
masses, where they have been long exposed to the air in the 
natural process of decay, lose their angles first. When these 
masses hare thus become rounded, they decay in conoaatrie 
lamellse ; but where the rock itself is exposed to the air, it 
separates into plates of various thicknesses, nearly vertical, 
and running north and south. In the sound stone there is 
i/koi the smallest appearance of a slaty texture, and it splits 
with wedges in aO directions. The north end of the ridge is 
the lowest, and has on its surface the largest masses. It is 
there only that the natives have wrought it; they have 
always ccntenled themselves, with splitting detached blopks, 
and have never ventured on the solid rock, where much finer 
pieces might be procured than h^s eypr yet been obtained. 
The Baswa, or bull, at Turiva-Cary, is the finest piece that I 
have seen.^*t 

** ImBsediatdy north firpm the ▼illage b a qnany of Balla* 
fum, or potstpne, which is used by the natives for making 
smell vessds; and is so soft, t)iat pencils are formed of it le 
Write upon booki, which are made with doth blackened anJ 
^flbied with gum. Both the books and the neatness of th# 
writing are very in^iior to th^ simifcir ones of the peo^ of 
Ava» who, ia fieust, are much tether advanced in the aits 
than the fitiid«s oCthis country. This potstone separates 
into lai^e amorphous matoes, m^ covsrsd with a ernst in n 

• OfKirwui; ciyrtallised nderite. 
t VsLiLpiGi. 



decaying state.; and some of them are entirely penetrated 
with long slender needles of schorlnoeoufl actiiibte.*' ^ 

The hill on w&ich Mail-G0tay etanda coodrta of a kind of 
gneiss, but the description is very confiised: .also a granitel 
of black hornblende slate, mixed with white qnartz in such 
a manner that when broken longitudinally the quartz forms 
Tehis, when transversely spots, t 

'' The stratu OA the Ghats are mnoh qoveivd with tiiA 
soil, ao that it k hi a few places aaitf that iksf are to 
be seen. Having no oompass, I oootd Bot asoeftma tliaiv 
course J but liur as I coidcl juc^ fnm thi aim in a e^uatry 
so^hOly, they af^ieared to mii north and 800th» with a dqp to 
the east of about SO degrees. WheMPer it aqppean •n* the 
suHhce, the loek, akhough cnctremely hard m tough> ia tea 
atate of decagr ; and owing to tii^ deoay, Itt atntifled mtopa 
is very evident. The plates, indeed, of wMeh the strata con^ 
slat, are in general under a Ibot la thickness^ and an sub* 
divided into rhomboidal IhigmMits by fiasorea wbieh have % 
amooth surlhee. It is i»t>p0rly an aggregate atona, cwnpoaad 
of quarts impregnafted with homblende. Vtota thia last )t 
aequirea Ma great toughness. In- decay, die homblande in 
aome plates seems to waate ftstar than in others, and thoa 
leaves the stone cBvided into adaea, ^ich are akematdy 
))oraus and white. ' 1 am inclined to tMidr that all nioun* 
tains of a hornblende nature are less ru^ed than thosa of 
gianite, owli^ to their being more easily cisconipeaed by the 
aetioB of the air. This rook contains many smaU efystallisod 
j agtid c s, apparently of bran.** t 

• Voi.u.p;e9. fiu.H.|K;s. 

t Vd.i3Lp.t0l. 



• • / 



532 APfSNDIX. 

No* IX* Letter of JUL Daubutsm^ on his intended 
treatise of Geognos^y to the auHitm** 

** Paris, le 20 Geimmft!, an 13. 



'' MOWSIBVS 



f 



'' Je BuiB bien fach6 de n^ pas m*^tre troave chez moi 
lorique tous j etez vena :- j*aurois vbulu avoir Flionneur do 
voiu aaluor avant voire dep^M. Mon traite de QkngaoM, 
d*a|ires leB principes de M. Werner, avanoe, mais kntementj 
Tu le peu de Cems qtie j*ai a ma dispoeition pour y travailler* 
Je Went de rediger definitivement deux longs cfaapitres presqo* 
entitooieDt de Geographie.phyaiqiie, et qui oertainment voua 
ioieresseront beaucoiip : Tun traite des infgalites de la aur* 
fiice du gk>be» notamment des montagoes, oa y traite asses 
en detail des diverses parties ' d'une chaine de montagnea, et 
des obaervatioDs A fiure sur chacune d*elles ; Tautre a princi- 
palement poor objet Tiu^tien erosive des eaux et de Vat* 
mospbere, sur 1^ surface du globe, et Ton y examine jusqu*i 
quel point cette action a pu« non produire, mais fa^onner leg 
inegtJitfe de cette surface. • Je suis dans ce mom^t ocoupi 
du cbapitre peat-£tre le plus interessant ; cehii qui traite de la 
•tnicture, de la stratification, de la superposition, des rocbes : 
aci riep n'est tbeorique, ce sont des fiiitc^ ce spnt les principes 
qui doiveot guider Tobservateur. Je ne puis dire avec pr^ 
cision A quelle epoque mon travail sera livr^ 4 i'ijnpreBsion» 
li*£taat pus maitre de disposer de won tems amformement 
a mes desirs. Lorsqu*il aura paru, je le reoommande 4 votra 
indulgence, et serois tr^s flatti 8*il pouroit avoir Tappro* 
bation d'un juge aussi iclair^ que vous. 

'' Paignez agr^er les assurances de ma consideration 
distingui^ 

« J. F, oaubuisson;* 



rf V <» ' 




"^ 



APPBNOIX« 533 

' No. X. Explanation of the direction (tnd incUAaiwn 

of Feins* 

[See the Plate] / 

» 

The position of metallic veioB is ascertained and described 
by three different angles; that of the direction, dip,, and 
incHntUion. 

The angle of direction^ or simply, the direction, \» ascer- 
tained hj observing the point of the compass, or d^ree of 
the horizon, it tends towards, as ^ B, Fig. 1. 

The dip is the angle which it makes with the plane of the 
horizon, as B ^ £, Fig. % . 

The inclinatioh is the angle which one of its sides makes 
with a vertical plane, as ^ 6 c. Fig. 3 ; where b c repre- 
ienti the transverse section of the vein, and a h that of the 
vertical plane. 

This is further illastrated by Fig. 4 } where J B repre- 
sents the perspective view of a metallic vein. C i> is the 
compate placed parafiel to the horizon, and £ f is the 
direction of the Vein. . 

The angle \F£ B is the dip, being the angle which the 
vein makes with the horizontal plane ; and the angle abc 
is the indinatioD, or the angle which the side of the vein 
makes with the vortical plane a b. 



634 



▲fFIWDIX. 



or thU Hist is that of Mont- 
martre, which however only oo- 
cure in (reods or nodnlosy vod 
grMdy ^dt m bwiitf to llie 
other Strocmra. 



No. XL Examfki of the appUcaiion of the present 
system to Litholagy and MeiaUogy. 

LTTHOLOGY. 

DOH. I. SIDEROUS. 

11. SIUCEOUS. 

III. ARGILLACEOUS. 

IV. TALCOUS. 
V. CALCAREOUS. 

VI. BARYnC 
Vn. STRONT1A17IC. 
. VW* ZIROQNIC 
IX. SALINE. 
X. COMBUSTIBLE. 



DOMAIN VIU. 



DOMAIN vn. 

STirONTTANIC. 

Mqdc I* Strontian^ or Car- 
bonate of Strontian. 

StruCTURbL Massive. 
Aspect 1. Entire. 

% With haiytei, gal^ 

Structure IL Ciysfallised. 
Vmietiei^ green, white*. 

MoPB II. Celesiine, or Sul- 
phate of Stronuan. 
Strijcture I. Fibrous. 
A^pedU Massive. 
2. Laminar. 
Varieiieaf of different colours. 
Structure II. Foliated. 
nL Radiated. 
IV. Compact. 

• Any ▼wy daguUr coloor would 
form a IXttnitif. 



ZIRCOtftC. 

Thi3 may be dlYided vki<i> 
two Modes, as there seema 
to be more sflex in the ja- 
eint than ia the sirooB) i»i 
at any lato the aaoda of 
combination is di/Scaent. «to 
they could aot b^ dMin- 
guished. 

MopB I, SGrcoa* 

STRucnmal. OloMhiL 

m. IavaiwMM<sra- 

talline fonns, which nmst be a^ 
scribtd. 

Mode IT. Jactnt, by the Fer- 
tianaeailed Yaoat. 

Structure I. In ronnd aiains. 

II. In various crspa- 
talline forms, which fenn aspeclii 
while the colours form vaiietiea. 



METALLOGY. 

DOM, L OOLD. 

n. PLATINA. 

ni. SILVER. 

IV. COPPER. 



APPtNOlX* 



635 



,DOM.v. iron; 

VI. TIN. 

Vil. LBAD. 

VIII. MERCURY. 

IX. ZINC. 

X. ANTIMONY. 

XI. ARSENIC. ' 

. XII. ms^UTH. 

XIII. COBALT. 

XIV. NICKEL. 
XV. MANGANESE. 

XVI. MOLYBDENA. 

XVn. TITAN •. 

XVIIi. CHROME. 

XIX, SCHI^ELE, 

XX. URANIUM, &C.&C. 

Dr. lliomMn observes that all 
metiili ^fe found in i5e firiioviiiff 
states: 1. Metallic, either alone 
fv^mbiiMifl. i. Corahmcdwitli 
salphar. 3. Oxyda, that is, united 
with omen. ^ Combiqe4 witi^ 
acids. Each order therefore, as 
be fdds, may be divided into the 
four f^Uowii^ Geofia. 

1, Allo^. 3. Qxydf. 

S. Snlphurets. 4. Sa{b. 

B^t HaUy has, oi^tbfcantnn, 
considered each metal as a ^e- 
Btts; aad Werner, an excellent 
jud^e of meta1!o{^ in particukir, 
ceosiders eaeh metal as a j^enns, 
and the vahons combip^tions as 
species. 

But m Mode ehiefiy implies 
the mode of chemical combina. 
tion. it is evident tfaat tliese pre- 
tended ceqeraand species, which 
me wholly vaeae as being derived 
mm as anaioay amrely imad- 
nary between inert and animated 
nature, are roost properly and 
p^uliarW Modes. THe An>et!te 
are equally applioable as iii Petra- 
lod^ and Litholo^. The Struc- 
ture isalsoap^firabic to the «om* 
pofitio* ia gepen^j as in strtLc- 

* Amther uim wisil <^ prefer- 
«ble. In the GrukHtan b ffme. 



tv^ MVftfPlMI it il lilmtktgtf tp. 
plied to very shmU objects •. 



METALLOGY. 

DOMAIN I. 

GOLD. 

Mode J. Pure, or rather en- 
tire, for it always contains 
sihtsr or copper, 

ftTRucvuRBl. Massive. 

JOiptnm^f 1. in rpcks; f . in 
pepttos, or detached masses found 
in clay or sand, &c. 

StkocturbII. DjiMonriMted 

in roclis, sands, &;c. 
Structure III. Crystallised. 

Atpect 1. In cubes, or other 
regohur fonos. 

Atpeet % Dendritic, like 
bimncbes^ leaves, £(c. 

Structure IV. Earthy, of % 
brovmish rod, like Spaniik 
smiff. 

MoDQ II. Electmm, ^ 
greatly alloyed witli silver. 

Strvgturs I., Conp^otr 

Dendritic. 

MoBB in. AHoyed with an- 
timony. 

MobeIV; Alloyed with tha 

Svlvanite of Kirwan, so callt 
eq from Transylvania, where 
it is found; the Tellurium 
of Klaproth : but Kirwan s 
appellation is received by 
V\ emer* 

• See U^, p. f 4 (4> «^Vt»#J Vmh!^). 
vhefe hf s^js |he if%tur«l knowiedfo 
of ttoaes Rftses from their •tractnre. 
the chiail^ilAoii mmI^is. 



6d6 



ATPEMDIX. 



Strocturb II. Onpfaic Gold. 

There are mtnT 'other alloys. 
Hie SnlpbareU of cold are veiy 
dottbtlbl, as Uinaybe iopanted 
byniechanical means. 

There are no Oxyds oor Sakk 



DOMAIN V. 

IRON. 

NOME I. ALLOYS. 
ModbI. Alloyed with Ni^el. 

II. Alloyed with lead, 
ore. 

VfOMBlL 8ULPHURET& 
MoDB III. Pyrites. 

StrdcturbI. Massive. 
Aipeet 1. Common. 
, S. Hepatic. 
Structurb II. Crystallised. 

MoDB IV. Ma^dctic Pyrites. 

NOME in. OXYDS. 

MoDB V. Magnetic Iron- 
stone. 

Structurb I. ComfMct 

IL Lammar. 

ni. Crystallved. 

IV. Iron Sand. 

ModbVI. Specular Iron Ore. 

Structurb I. Massive. 

II. Crystallised. 

UL Micaceons Iron 
. . Ore. 

MoDB VII. Red Iron-stone. 

Structurb I. Sealy. 

n. Red Ochre. 
ni. Compact. 



Structurs IV. Red 
tites. 



Modb VIIL Blown Iran* 
stone. 

Structurb I. Sealy. 

IL Ocfaraceooa. 

m. Compact. 

iV. Brown Hcim* 
tites. 

Modb IX. Spathose. 

Structurb I. AmoipbooB. 
n. CiystaUised. 

Modb X. Blaek Iran Ore. 

Structure L Compact. 

II; BfawkUeoM. 

tite. 

Modb XI. Cl^ Ore. 

Structure I. Roddle,«rRe4 
Onik. 

Structurb n. Cohnmar. 

UL Lentiealar.. 

IV. Jasper Ore. 

For common Clay Iroo-ftoae, 
tee Petralogy. * 

Structure V. Ea^ Stone. 
VI. 



Mode XII. Bog Iron Oie. 

Atped 1. Morass Ore. 
S. .Swanp Ore. 
S. Meadow Ore. 

NOME IV. SALTS. 

Mode XIII. Carbonate of 
Iron. 

Mode XIV. Phosphate of 
Iron. 

Structure I. Compact. 

n. Native 
Bhie. 

m. Witti 



4 



APPBNDIX. 



637 



liloDE XV. Aneniate of 
Iron. 

Structure!. Crystallised. 
II. With Copper. 

MooB XVI. Green Iron 
Earth. 

Aapeckl. Friable. 

S. Coherent. 

HiiB may be compared with 
the PeCndogy, in regard to tiie 
Structures and Aspects. The 

Knera of Thomson have not 
en admitted by other writers 
who arrange all the species hi 
■accession, without dividing them 
into aenera. Bat as these huge 
divisions of Hiomson seem very 
nsefal, they might be retained 
under the name of Komes, or 
■nhsidiary districts. 

In Lithology Dr. Thomson not 
havhiff admitted Orders or Ge- 
nera, but only Funiiies and Spe- 
cies, no coofasaon could arne; 
and the Modes beh>ng to tiie 
mixtures of the same substance, 
as Strontian is one Mode, ana 
Celestme is another; that is, the 
Species of Werner become 
Modes, while his Subspecies be- 
come Structures. 

In Kke manner if we take Iron 
the first Species, Native Iron is a 
Mode, or ^Pecial chemical com- 
iytnation. The second Species, 
Iran Pyrites, is another Mode 
with four Structures, Compact, 
Radiated, CeDuUv. and Capil- 
lary ; the Hepatic being au As- 
pect The fourth Species, Ma^c- 
netic Iron-stone, is also a chemi- 
cal Mode of preat importance ; 
whereas in fouowing Dr. Thorn- 
soli's arrangement it is merely a 
Stracture, while there is not only 



nothii^pafticnlar in its exterior 
Structure, but its Aspects, the 
Compact, Laminar, and Crystal- 
lised, are real Structures. Tlie 
fifth Species is Specular Iron 
Ore, which becoming a Structure 
instead of a Mode, the terms 
Massive and Crystallised, which 
belona to Structure, become 
mere Dive rsities. In the others. 
Amorphous, Crvstallised. Com- 
pactfColumnar, Pisiform, Kartiiy, 
Decome Aspects instead of Struc 
tures. 

It is therefore necessary m the 
Metals, as in the Eartfis, that 
each new Species or different 
combination, for example, widi 
Gurbon, Arsenic, &c. or with dif- 
ferent modifications of various 
Earths, should be called a Mode, 
as in the other provinces that 
word supplies the term Spi'cies, 
and implies in itself a new mode 
of chemical combination ; and in 
this vray only can the term Struc- 
ture revert to its origuial destina- 
tion. 

The classical word Nome, de- 
rived from Egypt, the parent 
country of ^emistry, may be 
found Tery appropriate, as al- 
ready expnined. 

Toe dignity and Importance of 
the Metals also reqmre a multi- 
plication, instead ofa diminution, 
of the higher terms in the nomen- 
clatnr^*^ Nor must it be forgot- 
ten that the very nature of the 
sulnect, in which the substances 
and their qualities are of them- 
selves various and vague, would 
render any attempt at mathema- 
tical precision rather pedantic 
than usetul or distinct (vbt quali- 
ties, like the substmces tlieoH 
selves, often nasshig into each 
other); and that every system, 
even the Newtonian^ has in ano- 



!/ 



3 






"\ 





^h. 




7.eiit»chlle lo.QcUtttt l).Muiel<t 

a.GiiitMinr uJh^ipiritr u.ttattaUU 




,1- ^ 




'^ 



<0 '^ 



f^MilaJ ai AiAit iinra A-utt. itu, *i 






«l 



INDEX. 



If 



ACTiNOTB Rock . . • ii. 15S 

Actiiiote, Siderite, Mica . 14 
Ahbttter, 

Characten of . . . i. 496 

Sites 499 

Jameson's obsemtions 500 
Brard*s account t>f Gyp* 

8008 ib. 

Monainentiof . . • 501 

Anydrons .... 503 

Observation . , . , 503 

Alabaster Dec ii. 251 

Alam Rock, 

Name of .... \ L 24C 

Ferber^ account . « ib. 

Massive ; . . . ^ .247 

Characters of ib. 

AlaminoQs Slate, 

Characters of ib. 

Common . • . 248 

Sites of • . ib. 

Glossy^. . . . 249 

Alom earth . • ib. 
Alabastrite, 

Ancient 458 

With Stalactite and Sta- 
lagmite, the Sinter of 

the Getwns ... ib. 

Pliny's accomit of 459 

Modem 461 

OfVoitem 462 

The Dnya alabaster ib. 

Varieties and sites of 463 

FiorHo t>f the Italians 466 

AmyrdaKte' 89 

Formatioasof ... 90 

Origin 91 

Witbagates ... 92 

With calcareous spar 93 

With open pores . . 95 

nBomalons . . . . • ii. 58 

Oenend observations ib. 
Salts and combostibles 59 

Coal ...... 60 

Pyrites . • • . . ib. 

How ranked . • « 62 

Anthracite i. 552 

Bom's accomit of • 553 

OftheA^pt ... 554 



Brongniarfs accomit Of i, 555 

Friaue 55B 

Scaly ib. 

Schistose .... ib. 

Globohir .... ib. 

Kilkenny coal ... ib. 

Swansea coal ... ib. 

Anthracite . . • 561 

Compact ... ib. 

Lammar ... ib. 

Kirwanite .... ib. 

From Kilkenny . 562 

From Swansea • ib. 
Argil, 

How obtained • . • 239 

When combined . . 240 

Homogenoos . . • lb. 
Eminent in gemmology ' 241 

Argillaceoos Olutenite 283 

Largei^rained . . 284 

flSaossure's description ib. 

Bricia of Scotland 290 

Granwack .... 291 

Bersrmamte . • • . ib* 

Smwl-grained ... ib. 
Jameson^ distinctions, &C. 29!2 

Argillaceous sandstone 294 

WfietBtone, Sec • . 295 

Gmelin^iarrangement 296 

Sanssmv's observations ib. 
Aig:illaceoos Intrite, 

£xtcnt and importance. 281 

With crystals of felspar 282 

Clay porphyry ... lb. 
With vanous crystals 



Barytic RdA ...» ii 138 
Baroselemte of Kirwan ib. 
Accomit of a singolar 
rock near Ambierle ib. 

Basalt, • 

Characters of . . • I. If 
Formatiom .... lb. 

Proper ib. 

Of the ancients . . 13 

Fme, termed Basahin ifar. 
In variousplacn. , 19 

DistingaisDSd ISraiii M* 



640 



INPIX. 



tepar 



saltin . • • 
Observation on 
Extent of . . 
Of Faroe . ., . 
Of dabiooK ori}(in 
Amorphoas . . 
Sites of . . 
Anci4>nt oriental 
i olumnar . . 
Analysis. . 
Otiservation on 
Basaltin witb Earthy F 
Gebrite, whyralled , 
Sanssiire's description of 
a diamiclonic rock 
BasaUin,* .' . 
Characfersof • . . 
Tolcanbes' • • . • 
Of Etna . • . . . 
Of A'nverfpue . . • 
Brocbant's statement on 
Bronentari*s idea of • 
., Amorphoui . ., • . 
Uniform .' . . 
Minrled • . . 
Basaltic tnfa . . 
■ Brecia . . 
Colninnar, 

ITni^orm • • • 

Mingled . . . 

Basattin witti Siderite . ^ 

Rhazitp.Mrhy called • 

Basaltin Vvitii «(i1ex . . 

Ebensinite, why called 

Basaltin wifh Wacken 

Albci'tite, why called 
Basaltin with Steatite 
Baconif p, why called . . 
. How different ^om 
Saussnrite . . , 
' Witb steatite disseou- 
nated 
With <?]obales • 
BasaUin and Basalt, or Ba- 
ialtnn' ". . . ... . 

■ Of Meisn'^r .... 

Danbnisson's ac- 
ronntof • . 
Ancient banalt . • . 
Not volcanic . . 
Diff-rrnt nppcarancet of 
Observation . . . 
Easa^^in with Porphyry . 
Fxaihi»1es'of • . , 
Separnfioii of, how 
irtark*»d' 1 . . . 
B^taltin and Warken . ^ 
Werner's account 
Oboenralion on • 



i. to 
ib. 

vs 

93 
ib. 
ib. 

S9 

31 

' 58 

ii. 44 

ib. 

ib. 

L St 
98 

' 41 
47 
56 
65 
66 

er 

68 
69 
ib. 

70 

li.45 
ib. 

46 

ih. 

46 
ib. 
47 
ib. 

ib. 

ib. 
ib. 

166 
ib. 

167 
ib. 
168 
ib. 
ib. 
169 
169 

ib. 
170 
ib. , 
ib.l 



Obserrations on Dao* 

bnisson's opinion . I7f 
Basal ton, 

Characten of . . • L 7t 

Name ib. 

Gninstein • • • . ib. 

Werner's opinion . • 73 

Compact 74 

Slaty ib. 

KIink3tein not allied to 

basalts ».-••• 75 

Bergart '••.... i. SU 

Beryl Rock li. 130 

i^ituminous Rocks . , . 147 
Bitnnichs ' more pro- 
perly belong to che- 
mistry ..... ib. 
Mostly found in 

gan)!:arts . , ib. 

Werner's doubts ib. 

In Scotland ' , . . ib. 
Farther illnstrations of, 

necessaiy ' • . .' ib* 
Limestone with 
naptha or with 

petrol ... ib. 
Sandstone inth mi- 

neral tar . • tS^ 

Mnmia or asphalt ib. 

[ Bfti'minoQSsbale ib. 

Marl . . • ib. 

Limestone with 

caoiitchoa • . ib. 



Calcareous Evtib, 

How produced . • I. St6 
Characters and proper- 
ties of .... . < ib. 
Limestone produced 
by d^cdmpoation of 

miiriiSeshdls . • 378 
. Davy's experiments on ' 

lime ib. 

Calcareous tntrite . ' . • 519 

Porphyritic '. • , ib. 

Marble of Nonette . ib. 

Calcareotas Olote'nite . 590 

Lar^e-grained . . ib. 

Sm^nlar bricia of . 5S1 

The ^asleflfih a bricia 58S 

A trican bricia • • ib. 

Antique ..... 5t4 

Viol«»t 5f5 

Modern ..'.•• ib. 

' Bricia 6f Italy . . . ib. 

OrSpain ... ib. 

' OfFVaace . . 5?6 

Bridie d*Aleppe « Sftr 



itrDix« 



641 



BridaofAix . . . i 5«8 

OfEyf^Uen . . ib. 

Other bricias . . • 589 

Common of Sansmire ib. 

Small-ii^Tained . . • 5S0 

Sites of ... ib. 

OfFontaineblean 531 

Jameson's observatioiis 532 

Qmuiium .... 534 

Sanssiire^ observations 

OB tlM sandstone of 

Foors 585 

Sandstone of Vauclose 587 

Of -reeent formation ib. 

Other sandstones . • 538 

Sites 4 ib. 

Carbon •••••. 540 
How converted into 

carbonic acid . . ^ 541 

In the diamond . • 542 

Chalk - 504 

Characters of . , • ib. 

Sitesof ib. 

JamesonTs accoont of 505 

Shells in 506 

Indm^ted .... 507 

Crude ..... ib. 

Usesof 506 

Eggs ...... ib. 

Stmctores and«aspects 

of^varions . • . 509 

Clay, Spathose Iron ii. {8 

Chiy Rock, 

Characters .... i. 969 
The thonstem of Wer- 
ner X ib. 

Dolomien's description ib. 
Impregnated with iron 

isjasper .... 270 

Fremiently m coal and 

other nunes . . • 271 

Sitesof ..... ib. 

InSwissertend . , 272 

Porcelain day ... ib. 

Boles ...... ib. 

Almagra » . . . . 273 

day Shte, 

Distinction . . • « 249 

Jameson's account of 250 

Widely extended . • 251 
Distinction to be ob* 

served lb*. 

Kirwan's accomit of . 252 

Primitive .... ib. 

Secondanr .... 253 

Townsotfs Analysis . 254 

Hone a ^ . . . . 255 

Cameos of the Chinese 256 

Chmese musical balls 257 

VOL, II. 



Antique i. 258 

Laterite .^ « « • • ib. 

Helras*s account . • 259 

' Primitive . . . « 263 

Characters of . ib. 

Sites ib. 

Sfcondary . ^ . . 966 

Unifonn ... ib. 

Variety . • ib. 

With impressions 267 

Sites ... ib. 

Variety . • ib. 

Black chalk . « . • ib. 

Hone . 4^. . . . ib. 

Clay Slate Dec. . •. . . ii. 249 

t./0ai ........ 1. oos 

Sites ib. 

Ancient use of • . . ib. 

Soils 565 

Patrin'sremaria . . 567 

Structure .... ,569 

Metals, &c. in . . . ' ib. 

.Werner's arraogement 570 

Black ...... ^71 

Slate- . .• ^ . . / ib. 

Cannel 67t 

FoKated or Laminar . 573 

Coarse ...-.•• ib. 

Brown ib. 

Earthy ..... 574 

Alum earth . . • «. ib. 

Common brown . V' ib. 

Moor 575 

Observation ... ib. 

Soils ib. 

Brongniart's account of 576 
SlijM or dykes in . • 577 
Mmes of England 578 
Seldom of the same qua- 
lity 579 

Iridescent .... 580 

Common . . • 581 

Laminar or foliated ib. 

Cannel .... ib. 

Columnar ... ib. 
CoalDeow ...... ii. 251 

Composite, 

General obaervatlons i 

OmeUn's plan- ... ib. 

Werner's theorv . . s 
Remarks on Danbuis- 

son'spbn .... 5 

SansMre's, and others', 

remarks .... 6 

Pretended granites . ib. 

Cohil Rock i. 473 

Origin of ib. 

Site 474 

Corsilite, 

Description of . . • • ii. 78 

S T 



64£ 



IVDBX. 



Saii88are*8 jreipavks • ii. 79 

Sites ib. 

Smaragpdite • • • 80 

Analysis of • • 81 

Dbcompos^d Rocks • • 309 

Loaio ««•••• 210^. 

Mould ib. 

Limestone of Malta • 217' 

Kirwan's account • • 2S1 

Femunnous rocks • 222 

Basalf ib. 

Wacken • • * • • ib. 
Decomposition of im- 
portance to the arts 223 
Roman Pliaros . . ib. 
Pbyfiufs observations 228 
Decomposed Qasaltin • * 2S5 
OfGermaiiy • • • ib. 
AmygpaUte . • 2S6 
Volcanic natnre of . 297 
Effects of decomposi- 
tion ...«,. 253 
Katnrepf «, .. • • ib. 
Rapid decomposition 254 
Rmn of Piura or Fleiin 255 

-Dialla^ 81 

./Diamictonic. 

General observations 36 

,. ' Derivative rocks • • 37 

Obs^initioat • • • 38 

From the Gneek • • 39 



Fblsitb,- 

Charactersof ... i. 160 

Palaiopetre of Sanssnre ib. 

Pctrosilex of WaUerins ib. 

OfKirwan . . • • ib. 

Varieties of • . • . 161 

OfCorsica . • • . 162 
Petrosilex, compactfel- 

spar • 163 

Two kinds of felspar 164 

Fe\iad. ...... ib. 

, Forms the base of se- 
veral porphyries • ib. 

Varieties ib. 

Common 165 

Sites of • • • ib. 

Lammar • , • • • 166 

Khnsstein of Werner ib. 

Analyses ... ib. 

KUnestein porphyry 

schistose .... ' 167 

Patrinite described . ib. 

Klaproth's account • 169 

Klingstone porphyry 

cbttsed with trap . 171 



Described • 
Not considered 

volcanic . • 
External Charac- 

lenB . • . • 
Analysis . • . 
Soda of Donnen- 

_ _^, bei^ . . . 

Earthy 

' Varieties . . • 

Febite and Basaltin . . 

Dolomien's account ot 
Felspar, 

Characters of • • • 

Common • • . • 
Foliated p . • 
Granular • . • 
Unctuous • • . 

Mingled 

Petuntze of the Qiiiiese 

When termed Kaolin 

Onalised termed La- 
brador stone . • • 

Green of Siberia . • 
Felspar, Calcareous Spar 
Felspar, Fibrous Siderite 
Felspar, Quartz, Garaets 
Felspar, Quartz, Talc • 
Felspar Dec. , . . • 

Changed into kaolin • 

Into clay • • 

Ferruginous Quartz • . 

Zozimite, why called 

Sanssure*s observations 



I I7f 

173 

ib. 

174 

175 

176 

ib. 

ii. 173 

174 

L 157 
158 
ib. 
lb. 
ib. 
ib. 
159 
ib. 

ib. 
ib. 
iLl6 
ib. 
15 
16 
241 



ib. 
43 
Qk 
iU 



130 



Garnet Rock • • • • 
Klaproth's and Vanqae- 

lin*s analyses . . • 
Cronstedt's opinion • 
Unknown except to 
Kirvnin • . . • 
OfScotiand. . • . 
Amorphous . • 
Witii siderite, fel- 
spar, and mica 
Geostrome , , * • • 
Globular Rock, 

Saus^ure*s. account of iL 136 
Gneiss, 

Distinctions of . . • L 211 



ib. 
ib. 

131 
ib. 
ib. 

132 
i. 542 



With red felspar . 
Primary .,....» 
With umestone, side- 
rite, and porpnyiy 
Fertile in roetala • 
Tabular, 

Sites of • . • 



Sites of . 



212 
ib. 

213 
214 

ib. 

ib. 



IITDBZ* 



64S. 



ptaneorLml 

Sites of 
Undolated . 
Sites 6f 

Sites of . • • 
Of two snbstances 
Gneiss, with Bloe Siderite 
Gneiss and Mica Slate 
Gneiss Dec. • . • • • 
Examples of • • 
Gnnite, 

Composition of 
When tenned-granitel 
With siderite . . 
Of Mont Blanc 
Of the summit 
Of .the rocks . 
Of the sonthem 
parts . • • 
Ofalan^gnun . 
The syenites of Pliny 
Varieties of • . 
Witii ielspar, quartz, 
and mica • • • 
Varieties of • 
Ofa small pain • 
Varieties of • 
Veined .... 
Bfin^led • . • • 
Anaent scnlptnre of 
Qfanite and Basalt . • 
Gnmite and Chalcedqny 
Granite with Gneiss 
Granite andGruitic Por> 



•^1 



JomieiA obserya- 
tionson . • . 
Granites • • • • 

Porphjriiea • • • 
Monuments of Rome 
Sitesof .... 

Gtaoite and limestone 
Granite with Sappare 
Gianite with Schorl and 
Garnets ....... 

Granite and Slate « . 
Saosrare's renarks 

Further ohsemh 
tioyos • • 
Gianite Dec ... 
OfBenNeris , . 
OfSochondo • « 
OfOdonTdidaa 
Kaofti . . .. . 

In Auvaiipie • • 
Eaou nples of • • 
Granitlu,. . . 

Described • • . 
Green .... 



i.fl4 

ib. 

215 

ib. 

ib. 
216 
U. 27 
189 
247 
ib. 

i. 177 
178 
179 
180 
181 
184 

188 
189 
ib. 
190 

192 

ib. 

195 

ib. 

197 

198 

199 

ii. 175 

17 

175 

176 

ib. 

178 
184 
185 
188 
20 
9S 

19 
20 
21 

25 
241 
24S 
ib. 
244 
245 

ib. 
246 

I 201 
202 



Granitoid i. 209 

Calcareous granite • ib. 

Argillaceous • . 210 

Taicoui ib. 

Graniton ...... 202 

Grmitic Porphyroid, 

Described .... 210 

Sites of ..... • 211 

Green Granitel, 

Egyptian .... 962 

French manufiictoir of S6S 

In England and Ireund ib. 
Gtanitel, 

Definitions of ... 203 
Kirwan^ obserrations 

on mica • . . . . 904 

Wemerite .... ib. 

Lehmanite . • • 206 

Henkelite . • • • 207 

Graphite 544 

Brongniartf s account of 546 

laminar ..... ib* 

Granular .... ib. 

OfBorrodala . • . 549 

OfCfaamooni ... 550 

Maisive 551 

laminar ib. 

Green Marble, 

Green, characteristic of 

magiiesui .... 96S 

Also called serpentine ib. 
Verde antico, 

Laconianoftiieai^ 

dents ... ib. 

Pliiq^s rarietics . 367 

Tbebaicus . • ib. 

\fkde antico, Brard^ 

account of . . . 268 

Notabrida . . ib. 

Columns of . . ib. 

Spartan .... * ib. 

Other antigae marbles 570 

Marble of Polaeven 271 

Of Campan • . tb« 

Marbred'Ecosse . . 372 

Marble of Anglesey . ib* 

Gypsum, 

Chanictenof • . • 482 

Primitive .... 484 

Patrin*s opinion . . 465 

Geognostic relations of 486 

Colourof .... 48r 
Sare^ description of 

Montmartre . • . 488 

Bones in 492 

Basaltic selemte . . 49^ 

Primitive .... ib. 

Striped 485 

Crystallised, beloiMi to 

fitinlogy . .T. m 

2 T 2 



) 



644 



IMOBX;, 



* OmoUMi • i. 4l9T 

Grey 496 

GypBom with Marl • • ii. 56 

Vattqiielite..wliy called ib. 

Oypsmn widi Silex . • 57 

Davite, whr called • ib. 

Marble of Yulpino • ib. 

Uni&rm . • • . ib. 

Veined • . • iK 



Igomitb, 

Whence the name L fTB 

Klaproth's analyw . ib. 
BiloiteinoflheQennans ib. 

TVanaparent ... i79 

Opake ....•• ib. 

ladnrated Mod .... it Sr5 



American volcanoct • 
Melted snow of Etna 
Eruption of MacafailMi 

Iron Hiu& . • 

Sites 

• Ber^nuu/s acconnt of 

Taberg 

Patrin's renuurfcs 
jon. • • • • 
Patritf 8 farther obser- 
▼ttiooB • • • • • 
Account of Blago- 
dat • • • • 
Account of Kefrr 



ib. 

sr5 

ST6 

156 

ib. 

156 

158 

ib. 

ib. 

159 
161 
ib. 

i. 95 
96 

9r 

ib. 

98 

99 

it U9 

Jad, the pada of the Ita> 
itam .••..•• i. 347 
Wh^r not deeeribed in 

tins work ... ib. 
Analyna of not aatia- 

factory • • • . ib. 
Conican £|[een, the fel- 

rite otf Werner . . ib. 
Seems nearly the same 
with the ioottite of 
the Chinese ... ib. 

OUIed iemanite • . ib. 
Werner*!! nephrite . 348 
Various kinds of, not 

analysed .... ib. 
Felipath compact ja» 
digi of receut French 



• Entire, iron rock . . 
MizedyWithqaarts • 

Uon Stone, 

Charactenof • . • 
Compact . • . • 
Columnar • • • • 
Varieifated . • • . 
External characters of 
Geotnoatic ritnation 

Jactnti&ck . 



WritCIV • • k • 

Not suffidenily known 
' to be systematised 
Kastner's analjrsis 
Reasons for givini^ an 
account of 

Jad 

Jad, Schorl^ Garnets 

Jasper, 

Characters of 



White . . 
Smople . • 
Sites of . • 
OfSiberia . 
Extent . . • 
Common. 

Bhick • 

Red 

Green . 

Striped . 
Columnar 
Jasper, with Agate 

Chalcedonv • 
Jasper and iCeralite 
Masritre . . 
Sdustose 



and 



i. S4S 

549 
ib. 

ib. 
iL 81 

ir 

t 99 
100 
ib. 
ib. 
101 
ib. 
ib. 

103 
104 

ib. 

ib. 
106 

IL 15 
17» 
17S 
ib. 






Kbralite, 

Chamctenof • • 

Hbnistein • • . 

Petrosilex . . . 

Chert .... 

Massive .... 

Common. • • 

Sites of*. 

UnctDous. 

Tiaminar . • 

Siliceoos'SCliiBtna 
Chert . . , 
Varieties • . 
Keralite with Chlorite 

Kunkelite, why called 
Keralite I>ec. 
Kollanite .. .. 
Description* 
PnddingHStone of En- 

Nobleflmt ! I ! 

ChaUte 

Obsermtioo : . . 
Detached pebbles 
Breeding stone 
Sites • • . . < 
Mr. Parkinson^ obeer- 

Tations .... 
Shells in . . . 
Silex often recent 
Origin of pebblee 



1.153 

ib. 

154 

ib. 

ib. 

ib. 

155 

ib. 

ib. 

ib. 

156 

ib. 
S.51 

ib. 

HI 



99 

ib. 
100 
ib. 
101 

lot 

ib. 

105 
104 
105 
106 



INOIX. 



645 



De Ld^s obflerrationf ii. IC/T 

I>r. Kidd*t obserratioii ib. 

Fatrin'B accomit . . 110 

BFaitPs account . . 119 

Other sites of ... ib. 

Common puddinff-«toDe lis 

Peculiar toEttjMand 114 

Kirwan's fiffcilue . . 115 

Kidd's account . . 116 

Accompanies chalk . 118 

Obsenration ... 119 

Shells in .*••... 190 

Varieties of .... ISl 
Jionite, 

Distinctions of • • i. 4S7 

Name 499 

Characten • . • • ib. 

OfCaen 490 

Petworth marble, igno- 

rantly called Purbeck ib. 

Pnrbeck 431 

Portland ib. 

^OdledbyDaCosta 

Alkaline sandstone 489 
Pierre de faille, moellon 

oftfaeFVench • . 488 

Other kinds of . • • ib. 

Pyramids of E^pt . ib. 
The lapis troicns of the 

ancients .... 434 

Bgjpii/ak and other . ib. 

Brongfoiarf s account of ib. 
.Entire, 

FinMrained • • 440 

Sites of • • ib. 

-Coarse . • • . ib. 

Sites of . • ib. 

ConcMtic, 

With nummnlites 441 



lei- 



Labkador Rock . 
First appearance 

ACCOOKOf . . 

Moble, or opaline 

spar • • . • 
Norwegian bhie 
lava Compact . . 
Basaldn . . . 
Arrai^pement 
Volcanic basaltin 

lUth various snb- 
stancea . . . 
With frannents of 
(gected rock . 
Comnact lava with 

melted garnets . • 
Porous bualtin • • 
Brocfaant's account of 
J'erber's ideas • . . 



ii. 93 
94 
ib. 

96 
ib. 
815 
ib. 
814 
815 

ib. 

ih. 

ib. 

816 
ib. 

Sir 



Opinion of Fln^ • ii. 519 

Sites 590 

Omj compact 

uva ^ . • • ib. 

Grey lairas of FacQas 591 

Dolomieif s description 593 

Breislak's account • 594 

White compact lava ib. 

Brown .... 595 

' Porph^jrritic-lava • • ib. 

Dolonrieo's account of • ib. 

Lavas, remarks on 597 

Lava Vesieubo- .... 598 

■ Of siderite .... 371 

Sites of ib. 

Wittleucite . . 579 

Sites of . . ib. 

Withseolite . . ib. 

With olivine . • STS 

Withfelsite .... ib. 

Felsite faiva with sid^ 

nte ...... ib. 

With mica . • ib. 

LamJiteRock .... as 

Description .... ib. 

Uitnunarine ... ib. 

Sites ib. 

PatrinTs account . . 89 
Klaprotlf s analysis • 91 
Sapphire of {he an- 
cients .... 99 
Werner's lasnlite . • ib. 

Lemanite as 

lignite ....... i. 593 

German Beigart . . 584 

B r ongn i a r t 's account of ib. 

Jet 585 

Friable 587 

Fibrous ..... ib. 

Earthy ..... 590 
Limestone, 

Wbence-the term car- 
bonate of Hme . . 441 
Geologic rdations -of 449 
ConvcMved .... 4iS 
Saussure's remarks 
■ on .... ib. 
Chertorkeralitein . 445 
Mural precipices of . ib. 
Granalar, pnmitive • s 445 
Barely metalliferous but 
in Siberia and South 
America .... 447 
Remarks on .... ib. 
Formations of ... ib. 
Seldom pure ... ib. 
Granular, 

Common . . • ib. 
Chinese ^tablets a 

sparry ... ib. 



646 



IKOIX. 



Micaceooi . „ i 449 

Cfaaracten of ib. 

CoQchitic . . • . 451 

Shells in ... 452 
Observatiom on 
Ptitufpc or 

oceanic . ib. 
Zoopfaytic, 

Pisofite 456 

Sinapite . • • • . ib. 

If ore abundant than 

pisolite • • . 4St 

limestone with Anil • • iL 53 

Kl^MTothite, wtav called ib. 

AfarbleofGunpan ib. 

.LimetUmewithari^il ib. 

limestoiie .with Garnets . t9 

WiDi amorphous eainet ib. 

WiHi ci^talliaed . ib. 

limestone with Gypsum 54 

Layoisitei why called ib. 

Massive • • • 55 

Schistose • • • ib. 

limestone with Olivine . 50 

Ohyine and chrysolite 31 

limestone with Silex . . 55 

Bertholite. why called ib. 

Kirwan's obsemitions ib. 

limestone witii Steatite . 30 

Marble, with veins of 

steatite ib. 

With spots . . ib. 
lime-slate ...,.•• i. 467 

. Distinsnished ... ib. 
The eueareuB fimiU§ of 

WaUerins .... ib. 

Alternation of . . • ib. 

Gpolipe ib. 

OfMontCenis • • 468 
Micaceous . • • • ib. 
Common • • • • 471 
Quanr of, at Stones- 
field • • • . • ib* 



llAOif 98IA1I Glotenite, 
Larre-gnined . . • 
Steatitic briciaof 
Corsica . • • 
Small-ctained • « « 
Magneaianintritey 

Serpentine porphyiy 
near Florence • • 
Rocks of, described by 
Saussure . • • • 



Account of 
Tenant's analysis of • 
Dolomite dCKiibed • 



573 

ib. 
37S 



97t 

3r$ 

369 
564 

IK 



VarioQS fonnaof i 565 
Often contains tre* 

molite ... ib. 
Marble, 

Characters of • . • 58D 
Why by chemists called 

carbonate of fime • ib. 

GeojipDostic relations of ib. 

Duration of .... 581 

Of the temple of Serapis 58f 

Of Paros and Carrara 384 

Gpotine • • . « • ib. 
Cuanular, 

Egyptian, Rosso 
antico . . • 
Described • 

Rosso annnlato . ib. 

8«mesanto • • ib. 
Of various' colooiB 

(see also note) 590 
Farian .... ib. 
Statues of • 59i 
Pentelican • . 3k. 
Monninents and 
statues of . ib. 
Greek (so called) ib. 
Statues of . 5» 
Transluoent • • ib. 
Elastic .... lb. 
Of mount Hymettns ib. 
Ancient black . ib. 
Varieties of ancient 594 
Modem . • • 595 
Of Eiudand . ib. 
Scotland . . 395 
Ireland • . 597 
Norway . • ib. 
Denmark • 598 
Sweden • . ib. 
Russia and Si- 
beria . • ib. 
Germany 400 
Swissertiind . 401 
France • • ib. 
Spain ... 404 
Fortucal . . 406 
Italy . . • ib. 
Sicily . • • 406 
Asiatic . . 409 
African . • ib. 
Numidian 410 
American 411 
Compact ..... 414 
Ancient. • • . 415 
Modem ... ib. 
Some conchitic • 416 
Copchitic . . • • ib. 
LnrnacheBa . . ib. 
Varieties of . ib. 
Fttmodinorto • 418 



IHOBX 



647 



Ocdiio di pavone L 419 

Zoophvtic .... 434 

OrCiben ... ib. 

Other Bites of . 425 

Ofltaly ... 496 

OfSwiBseriand • ib. 

Uvble of Campan . . ii. 134 

Why noked amongst 

anomalous rocks • ih. 

Kedguttular • . • 1S5 

Green ib. 

Marble of Migorca . • 134 

Marble Dec 250 

Marlite , • L 475 

Description of • • ib. 

Marble of Florence • ib. 

Massive 477 

Ai^^iUaceons marble ib. 

Pictorial ... ib. 

Schistose 478 

Impressions of fish 

in ib. 

Of Mont Bolea • • ib. 

Other qoarries of • 479 

With impressions • ib. 

In different parts of 

the world . . ib. 

Miagite ..*... ii,6S 

jDescription of ... ib. 

Site 64 

Saussore's accoont . 65 

Ocular 74 

With straight lines ib. 

With zigzag • • ib. 

Mica and Actinote • . • 14 
Mica Slate, 

Arrangement of • • i. IfS 

Connexions . • . • ib. 

Rcgi^ar 123 

Irregular ..... 124 

^ Mingled ib. 

Micarel Slate, * 

Distinctions . • • • 312 

NlOUTB ii. 74 

Obsidian ...... 443 

In France .... 444 

Iceland .... ib. 

Bourbon .... 445 

IhehiUofMaiikan ib. 
Piadim de GalinaBBo, or 

vaTen-stone . • . 417 
Spalhmnni'sacconnt of 

the Ohttses of lipaii ibw 

FIfamientB • • . . 458 

Unctuous • • . . ib. 

Conrentsof • • . • 459 



Vitreans .... ii. 460 

Entire .... 461 

Porphyritic • • . • 462 
With white fibrous 

Teins ... 464 

Capillary . '. . ib. 

Granular ... ib. 

Resinous • • • ib. 

Variety of . . . • 467 

Offite, 

Cliaracters of • . • L 397 

Ophite of the ancients lb« 
Or Chiavenna, analysed 

byWeigleb . . . 328 

Anloqoityof • » . ih, 

Varieties of . • . • ib. 
Thebaic stone of the 

ancients .... 329 

Theban ophite of Lucan 330 

Dark ophite of Plmy ib. 

Ophite of Boot . . ib. 

OfLaet. ... 331 

Sites of ib. 

Omte with Silex ... 1152 

Pottalite, why caUed ib. 
OfBten, 

The Swedish name, pre- 
ferred i. 480 

Description of • . ib. 

Used as fuel ... 481 
Difierent kinds and 

sites of .... ib. 

Phosphoritb .... ii. 135 

Pisolite •...•.• i. 456 

Pitcb^tone, 

Character of . . • 218 

Compact .... 219 

Lammar .... 220 

Pftch^tone Dec. • . . ii. 2i8 

Porphyry, 

Name i. 75 

Base 76 

Wemerls ib. 

With large crystals of 

^d' 78 

Black .... ib. 

Green .... ib. 

Not the ophite of 

Pliny ... 79 

Ferber's varieties of 81 

Sanssure's statement on 82 

Blue 85 

With smaller crystals. 

Red ... 7; 86 

Sites of ... ib. 

Brown • • • • ib. 

Black .... ib. 



64^ 



IHDfiX. 



Grc^H 

Porphyry %fjth.Cbalcedony 
Porphyry Dec, . . . • 
Puy de Dome . . . 
. Sax1^n inejtalUfenim 

Bornite 

"With native gold 
Wi^h 9vWiinite • 
With (Teiidntic gold 
With noble o^ 
. &c. . • . 
Porphyrin .... 
Forphyroid • • • 
Porphyron . . . 
pumice .... 
Chie^y.febpor . 
Of Upari . . . 
Of Campo Bianco 
Orjgin of . . . 
Moontain of. , 
In beds . . . 
Globular . . • 
Compact . « . 
Poroos. . . . 
Fracture of . . 
Effects of heat on 
Varieties of , . 
Current . . . 
Another kind of 
Porous . . . 
Vesicular . . 
Fibrogs felsite 



i. 87 
ii. 13 

298 

ib. 

ib. 

239 

ib. 

ib. 

ib. 



240 
i. 87 

88 

ib. 
L 428 

ib. 
429 

ib. 
430 
431 

ib. 
4St} 

ib. 
434 

ib. 
4S3 
437 
440 
441 
442 
443 

ib. 



Quartz, 

Characters of . . . i. 146 

Compact opake . . ib. 

Swiitraqsparent . 148 

Uqctnons ... ib. 

' Qraqnlar ib. 

liiminar 15S 

Other strQctores of . ib. 

Quartz with Qas^ltin • . ii. 50 

Torricellite, why called ib. 

Quarts with Felspar • . ib. 

Gnericite, wny calted ib. 

Quartz with Iron ... 49 

HebnonUte, why called ib. 

Quartz, Limestone, and 8aus- 

snrite 15 

Quartz, Schorl, and Lime- 

^stone ib. 

Quartz, Siderite, Ozyd of 

Iron ....... 14 

Quartz with Slate .... 50 

Gbiuberite, why called ib. 



RUHITE, 

Descriptioo .... U»'95 

Name ib« 

Sites 86 

With distinct crystals 87 



1^ 
142 
14S 

144 
ib. 

146 
ib. 

ib. 

ib. 

246 



Saline Rocks .... 

Bowles's account of • 
Salt mines, sites of . 
Of Peru, UUotfs 
account of 
Kirwan's account . . 
Mountain- of salt in 
North America . . 
Other salt mines . • 
Entire, Bine, red, 
and white . . 
Mixed witii 
gypsum . 
Sandstone Dec. . . . 

Sites of ...... 

Saussurite, 

Characters of . . . i. 354 
Between basaltin and 
serpentine • . . 
Pierre de come of Saw- 
sure 

Roche de come with 
steatite •. . . . 
Magnesian propen- 
sity of . . . 
Passing* to serpen- 
tine .... 
Of a black base la- 
va of Ferberand 
others . . . 
Com^enne cBfficult to 
determine ... 
Compact -• . . 
Trap .... 
Lydian .... 
Vulgarly called 
touchstone . 
Primitive or tran- 
sitive .... 
Of Brociiant uncer- 

. lain 

Sanssurite Dec. . . . ii. 

Decayed .... 
Schistose Keialite andlime- 

. stone 

Becchfirite, why called 
Scfaistose Kerahte and Slata 

Boylite 

Scrpenone, 

Characters of . . • i 
Of Mount Rosa . • 
Italian gabbro • . • 



555 
ib. 
956 

ib. 
ib. 

ssr 

ib. 
SS8 

ib. 

sa> 

iK 

ib. 
f49 
S50 

51 
ib. 
ib. 
ib. 

984 

5S7 



IHDBX. 



649 



OfRotfiHoni • • • 
Of Mount CeiTHi. . 
Magnetic hill of . . 
unmboldtf obser- 



Chenevix's analysis of 
Nephritic .... 
Asbestos and ani- 
anthiis almost 
constant in 
Amianthiis, obser- 
vations on 
Wemei's common' and 

noble 

Italian nephrite . • 
Biochants yerde antioo 

not correctly • . 
The noble of Werner 
rather belongs to li- 
thology or genamo- 

^OfJ « 4 • • • 

Kntire ...'.. 

Mingled . • . • • 
Serpentine with Baaaltin 

Bei]|r">anite, why called 
Seipentme i¥ith limestone 

Dark green» with grey 
limestone .... 

The same, nith red cal- 
careoasspor • • 
Serpentine with Siderite 

Blacolite, why calfed 
Shale and Coal . . . 

Impressions • . • 

Undbnn • • • • 

With impressions . 
Shells in MaAle • . . 
Short Rock • . • • 

Entire 

Mingled .... 
SklegeaTSiderooB Earth 

Its muvenality • • 

Clharactenof . • 
Siderite, 

Charactenof . . 

Hornblende of the Ger- 



t S41 

MS 
94S 

344 

343 
346 



PrimitiTe trap • 

Ancient boMit • 

Analysis . . . 

Common . . • 

Uniform • 

Mingled 

Schistose. • • 

umiQinn 

Mh^ed . 



Siderite and Basalt • 
Sites .... 



ib. 

350 

351 
ib. 

ib. 



3Sf 
ib. 
353 

n. 53 
ib. 

ts 

29 



ib. 

53 

ib. 

191 

ib. 

19« 

ib. 

459 

132 

331 

ib. 

Ll. 

3 

4 



1. 



ib. 

ib. 

7 

8 

9 

10 

ib. 

11 

It 

13 

ib. 

16 

165 

ib. 



Siderite wifli Earthy Fdapar ii. 
Synesite, why called 




df 

ib. 
ib. 
ib. 
ib. 

Siderite, Felspar, Graphite 1% 

Siderite with Mica . . 41 

Democrite. why called tb. 

Siderite with fittlez . . 30 

Hennile, why called . ib. 

SauMore's description of 

the riased rock 40 

Siderite, Unctuous Qnarts, 

I^tes IS 

Saderoos Glotenite^ 

Chssed i. 135 

Podding-sloneo • • 136 

Large-grsined . . . IST 

BriSa basaltic ... 138 

Porphyritio • • ib. 

Small-grained ... lb. 

Semiprotolites . . . 139 

Lssite 141 

Ferrnginoos sand-stone 14t 
Sideroos-Intrite, 

Intrites distingnished 

from glntenites • 131 

Chttsed ib. 

VarioUtes .... 133 
Iron-stone with imbed- 
ded crystals ... 134 
Sideronmgnesiau Rodu, 

Serpentines .... If6 

Chlorite ^ . . . . 1$7 

Chlorite Skte ... vm 

Chanctersof . . ib. 

Sites • • . • . ib* 

Sanssore*s observation 1S9 

Actinote . . . • • ib. 

Glassy . •. ^ . 130 

Characters of . ib. 

Serpentine sideroos . ib. 

Qranolar ... 131 

C!ompact .. • • ib. 

Sflex, or Sittceons Earth . 148 

Sihceoos^Glntenite, 

Description or . . • SIS 

Origin ib. 

PufUliag«loMandbricia ib. 

Sandstone .... SS5 

Largely giamilated . fflS 

Oriimal and derifiliTe 997 

Koiianitea> . • •• . ib. 

Pebbles 

Green .... 

With roiled gnnite ib. 

Egyptian ... tJO 

Tnesame ... ib. 

Jasperbrida • • ib. 



t 



^0 



niDBX* 



Smafi-fpnaiiied 

Kirwan's account 
CooiM 
Fine . 
Saoisore's varietiei of 

8ificeoiui lotrite, 

Gefman potphyiies 
Keralite porplnrTy 
Febite . ... 
PKcb^tone • . • 

flinapite • • • • . 

Slate, 

Quuractenof • • 
Names .... 
Potosi • . . * • 
Qoarriesof • . . 
Mines • • • . • 
Quarries of Ancers 
Ofltaly .... 
OfGennany . • 
Other sites of • . 
Quarry of in Com^fall 
Common • • • • 
Varieties of . 
Massive • • • • 

Slate and Ctdorite Slate 

Slate witii lime . . . 
Palissite, why called 

Slate witfi Magnesia 

Valentinite, why called 

Slate with Silex . . . 
Lallite, why called 

Slate Dec. .... 

Smectite, 

Called fallen* earth 
Characters of . • 
Ben»nan*s mutake . 
Da Costa's information 

on 
Use of 
From Cimoloa 



Mingled with qnarta 
Sit^of .... 



of 



Steatite, 

Quuracters of 
Klaproth's accovnt of 

Analysis of . 
Da Costa's aocooit 
soap earth or • 

Iwther acconnt 
Two distinct stnictnres 

of 

Patrin's account of 

With oUite . 
OfSanssnre. 

Asbestiroim . 

Specular • • 

Kock • • • 



u. 



I. 



900 


Soft j 


I. 324 


ib. 


Sites of ... . 


325 


831 


OfLeske .... 


ib. 


236 


Haid 


926 


ib. 


Compact . . . 


ib. 


ib. 


Laminar . . • 


ib. 




Steatite with ArgU . . 


ii.52 


2f0 


StahKte, why called . 


ib. 


Ml 

ftSt 


Steatite and Asbestos . • 
Sanssure's account of a 


189 


ib. 


rock of .... 


iW 


456 


Substances qected or 






changed by volcanoes • 


515 


105 


limestone .... 


516 


ib. 


Parasitic stones in 


ib. 


107 


Granite 


517 


ib. 


Blica slate' .... 


518 


106 


Slate ...... 


ib. 


111 


Basalton 


ib. 


118 
ib. 


Porpliyry .... 
Sand-stone 


ib. 
ib. 


ib. 


Sulphuric Rocks . . • 


153 
154 


119 


Jameson's account of 


130 
121 


POTphvry with sulphur 
Mica slate with sulphur 


ib. 

155 


ib. 


limestone with sulphur 


ib. 


173 


Sandstone . • • • 


ib. 


49 






ib. 






48 
ib. 


TAtC. 

Distinctions • • . 


L301 


47 


Common 


302 


ib. 


Venetian .... 


305 


240 


OfChili 


ib. 


275 


Chalk of Brian^on 
Muscovy ..... 


304 
305 


ib. 


liuve foliated . 
Undidated . • 


ib. 


976 


ib. 




Involved .. . • 


306 


ib. 


Mingled . . • 


ib. 


277 


Massive 


ib. 


ib. 


Varieties . . . 


307 


ib. 


Talcoos Earth, or Magnesia 


288 


ib. 


Talcous Slate, 






Cliaracters .... 


309 


313 


OfSanssnre, described 


ib. 


314 


TopacRock i 


iLl27 


315 


Transilient Rocks, 

Distinct firam transit 




ib. 


live 


163 


316 


Interesting in the study 






ofgeology . . . 


164 


318 


Tnfii . . , . . . . 


1.509 


319 


Description of .... 


Ib. 


ib. 


Vcnry modem . • . 


510 




Condiitic .... 


ib. 


320 


Temple of Jnpiter 0» 




321 
323 


lympiua|Of ... 
OrSt.Fdippe • . • 


511 
512 



IHOIZ. 



651 



• • • U 51S 

Breidak's acconnt 

of 513 

Poroiu 518 

Concliitic • • . • ib. 

Tabular 519 

Tafo ii. 378 

Compoation of • . ib. 

A chief part of Tolcanoes 380 

TuY«8, or punolaoa 4AI 

Puzzolana • • • • 489 

Trass, or tarras • • 4S4 

Uses of pouolami 406 



VOLGAlflCy 

Volcanoes namerous . S68 

Depth of fbel ... fG9 

Many extmct . . • 270 

Chasms 27S 

Effects of water . . 278 
Compact la?a • • . 279 
Kirwan's opinion . . ib. 
Other opimons . . 290 
Compact kn^ dnbions 292 
Basaltic columns com- 
pared with hva 299 
Origin of basaltin . . 296 
Fenara's system . • 298 
Submatine ▼olcanoes 299 
Extinct Tolcanoes 302 
Origin of bMltiD . ib. 



No modem hfm pii^ 

matic iL 306 

Volcanoes 

Singniar • • • ... 519 

Patiin's theory . • ib. 

Volcano of Stromboll 520 
Volcano in the Isle 

Boorbon • . • • 523 

Submarine volcanoes ib« 
Volcano in the Isle of 

Thera 524 

Submarine volcanoes 525 

Island of Themria 526 

Of Automate . ib. 

OfThia ... ib. 

Eruption of 1767 . • 528 

Volcanic Glntenite • . 503 

Peperino of the Itifians ib. 

Bricias 504 

Catalogue of, by 

Fkuias • • . 505 

Volcanic firida • • 515 

Pepmno • • . ib. 

Lendtelava • . ib. 

Volcanic Intrite ... 469 

Witiileucite • • • ib. 



Wackbw i. 273 

Between basiatand day 274 

Often a com^enne ib. 

iWackenandday • • • iL 172 



n 



• ■ 



653 



PLATES IN VOL. L 

The vignette in the title page is an ideal yiew of mountains 
and rocks. The eagle> the chief inhabitant of such regions, 
is introduced to animate the scene. If allegory be wished, it 
may appear in the dispersion of clouds of obscurity — but 
that the eagle eye cS some fiiture Newton will be required, 
to explain the laws c^ nature in this difficult^province. 

Dom. L Siderous. Grand cavern of Stafla, from Pen- 

* n^t •••• •• • • p. 1 

II. Siliceous. Mont Blanc, from the vale of Cha« 

mouny, chiefly from Saussure 149 

III. Aigillaceous. The Andes, near (Quito, which 

city appears on the upland plain. Hie 
highest mountain on the right, intersected 
with clouds, is Chimborazo. The next, 
a volcano, is Cotopacsi j that on the left 
of the plate is T^mguragua. Froin Bou- 
gner's Figtare de la Terre, ¥mB 1749, 4to. 239 

IV. Talcous. Mount Rosa, from Saussure 298" 

V. Calcareous. The I^renees, with the sunmiit 

of Mont Perdu, and Cylinder of Biiarbore. 
This view is taken from the vale of Estaub^, 
to the north of Bareges, From Ramond's 

Voyage au Mont Perdu 37^ 

VI. Gaibonaoeous. The coal hill of St. Gilles, near 
liege, from Lam. Th. de la Terre. See 
the Appendix •••.•••..» • •••»• 540 

FINAU, AT THE BOTTOM OF THE PAGES. 

1. Chemical instruments, portable furnace, blow-pipe, 
&c f»ft«ft*t«f»t...«t.tt.£nd of Introduction. 



554 ELATES km FINALS. 

% An Jretia, from Haller^ one of the plants which 
SauBSore found at the greatest height of vegeta- 
tion on Mont Blanc p. 142 

3* Silate Aeandis, another plant in a similar situation •. S75 

4. Idchm Ftafia-aceus, often found on high rocks. 

Hoffiaaan> tab. ix. fig. 2 539 

5. IicA«» Ffonditf^ also often alpine. Hoffinan—.£ndof voL 



PIATES IN VOL. n. 



Title. An altar of rocks^ inscribed in the ancient Greek 
character, '' To the Gods Creators." 

Dom. VIL Mount Caucasus, from P^Jlas • p. 1 

Vni. Alh^rical •• 36 

IX. Glacier of Miage, from Saussure 58 

X. Carpathian mountains, from Townson's Tra- 

^ veis in Hungary •#•■■•».»—»»—.>——.— — »»> loS 
XI. A granitic mountain fiJling, by decompo- 
sition, imaginaiy .••• • 809 

XII. V^sutIus during the eruption of 1794. From 
Sir W. Hamilton • 



»• iOf 



1. An Alpine lichen, from Hoffman • 10t 

2. Lichen capercUui, Hoffman, zlil. 1 • 590 

Mathematical plate of Veins ..• • «.. (i33 

Two plates of l^dls • » End of vol. 



fkiDted by S. H«BuItoii, Wc7bri4ge. 



1