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Full text of "Petralogy. A Treatise on Rocks: A Treatise on Rocks"

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k F Z-M- 1 ^ 2. Q.) 




HARVARD 
COLLEGE 
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CONTENTS 

op THE SECOND VOLUME. 



Domain VII. Coupoiits. p. 1 

Nozoel. SiderUe, with Garnet Bock 11 

II. Sidente, FeUpar J Graphite 12 

HI. Siderite, Unctuous Quarti, Pyntei ib. 

IV. Porphyry, with Chalcedonif ..•. 13 

V. Jasper, with Agate and Chalcedowf •• • ib. 

VI. Mica and Actwote ^ 14 

VIL Actinote, Sideriie, Mica «•. ib. 

VIII. Quartz, Siderite, Oxyd of Iron .«.•• ib. 

IX. Quartz, Schorl, and Limestone 15 

X. Quartz, Limestone, and Saussurite ib. 

XI. Felspar, Quartz, Garnets , ib. 

XII. Fel^ar, Quartz, TeOc 16 

XIII. Felspar, Fibrous Siderite ib. 

XIV. Felspar, Calcareous Spar < il^ 

XV. Jad, Schorl, Garnets 17 

XVI. Granite and Chalcedony «.. ib. 

XVH. Granite, wUh Schorl and Garnets 19 

XVIH. Granite and Limestone « 20 

XIX. Granite and Slate • ib. 

XX. Gneiss, with Blue Siderite 27 

XXI. Clay, Spathose Iron 28 

XXII. Serpentine, with Limestone ib. 

XXIII. Limestone, with Garnets 29 

XXIV. Limestone, with Steatite • 30 

XXV. Limestone,.wUkOlivme *„,, ib. 

XXVI. UmestaneywithActinote 32 

XXVII. Marble, with Asbestos 35 

TOL. II. b 



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XVIU 



•ONTBHTS* 



Komel. 

II. 

IIL 

IV. 

V. 

VL 

VII. 

VIII. 

IX. 

X. 

XL 

XII. 

XIII. 

XiV. 

XV. 

XVI. 

' XVII. 

XVIII. 

XIX, 

XX. 

XXI. 

XXII. 

XXIII. 

XXIV. 

XXV. 

XXVI. 

XXVII. 

XXVIII. 

XXIX. 



Nome I. 

II. 

III. 

IV. 



DoMAiir VIIL DiAMZCToiric, p. 9S 

Siderite, toiih Silex 30 

SiderUe^toUhMica 41 

Siderite, with Felspar 49 

Siderite, with Earthy Febpar ib. 

Ferrugimnu Quartz 43 

BasaUin, with Earthy Felspar 44 

Basaitm, with SidertU 45 

Bascdtin, with Silex 46 

Basaliin, with TVacken ib, 

Basaltinf with Steatite ...., 47 

State, with Silex ib. 

Slate, with Magnesia • 48 

Slate, with Lime , 49 

Quartz, with Iron ib. 

Quartz, ioith Basaltin 60 

Quartz, with Slate ; ib. 

Quartz, with Felspar ib. 

KeralUe, with Chlorite 51 

Schistose Keralite and Slate ib. 

Schistose Keralite and Limestone ib. 

SieaHte, with Argil 53 

OUite,with Silex ib. 

Serpentine, with Siderite 53 

Serpentine, with Basaltin ib. 

Limestone, with Argil ^ ib. 

Limestone, with Gypsum , 54 

Limestone, with Silex 55 

Gypsum, with Marl 56 

Gypsum, with Silex ., 57 

PoMAiv IX. Anomalous. 58 

Miagite « 63 

Niolite , : 74 

CorsiUte : 78 

Runite , , • 85 



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CONTBWTt. 



Nonse V, 
VI. 

vu. 
vni. 

IX 

XI. 

XII. 
XIIL 
XIV. 

XV. 

XVI. 

XVIL 

XVIII. 

XIX 

XX 

XXI. 

XXfl. 
XXUI. 



Nomel^ 
II. 

m. 

IV. 

V. 

VI. 

VII. 

vni. 

IX 

X 

XL 

XIL 

XIII. 

XIV. 



LasmHuRoek p. 88 

Granite, with Sappare •• «• 93 

Labrador Rock .•••• ib, 

KoUanite , ..,..,.. 98 

TopaxRock , 127 

Jacint Rock 129 

Beryl Rock* 130 

Garnet Rock .., ib. 

Short BocJr ,.,.. 132 

JctmoteRock ...« • • 133 

Marble of Majorca ..r.. «.... 134 

Marble of QvnpaHf^"** ib. 

Pimphorite ,.......-....^. ..<,.. ....••. 135 

Globular Rock , 136 

BaryiicRock 138 

Sadne Rocks m... 141 

BUiwtinous Rocks m*.. •.•...•••• 147 

Sulphuric Rocks 153 

Iron Hills ...., ^ 155 

Domain X Transilibnt. 163 

Siderite and Basalt • 166 

Basaltin and Basalt, or,Basalton ib. 

Basaliin, with Porphyry f 169 

Basaltin and Wacken •..,.....^... 170 

Wacken and Clay .., 172 

Jasper and Keralite .., » ib. 

Slate and Chlorite Slate 173 

Fslsite and BasaUin *. ib. 

Granite and Basalt 175 

Granite, with Gneiss,.,, ib. 

Granite and Granitic Porphyry 176 

Gneiss and Mica Slate ,,,, 189 

Steatite and Asbestos ib. 

Shale and Coal 191 

Farious , 192 



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•OVTBMTt. 

. .. DauunXL DBOOil^osfto. ' pw 9D9 

^oflie L Deeonqposed Battiltin • 835 

II. D.Porphyr^4.i*4.*4^ 838 

III. Jk Slate ..4 840 

IV. D. Quarts .,..4..44 ib. 

• V. D.K^ralite 241 

VI. D.Felipar »» ib. 

VII. D.GranUe < 848 

VIII. D. Gneiss. 847 

• IX. D. PUck'Stone....^ 148 

X. D. StmdsUme « ib. 

XI. Dtda^'sUUe « 849 

XII. D. Saussurde ^ ib. 

XM. D.Mitrhle , 850 

XIV. D.AUAasUr ib. 

Sffeets ^.Deeonpostitofi •.<••••••••«>•••••••••*• 853 

Domain Xlt. Volcanic. 86^ 

Nome I. Compact Lava ••••••••#•••«••••. .•••••••••••••••••••••f* 313 

II. Vesicular Lava ••••••^•.••••••••••••••••••••••••«.. 388 

III. Indurated Mud 373 

IV. Tttfo 378 

V. Pumice ••. 488 

VI. Obsidian 443 'j^ 

VH. Fokanic Inirite , 469 

VIII. Volcanic GUUenite 503 

IX. Substances ejected or changed 515 

General Remarks, and Examples of singular 

Volcanoes .,., 519 

FumoDols .......•• 545 

Veinstones ^ 561^ 

appendix 591 



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n>elu. 



PETRALOGY. 

A TREATISE ON BOCKS. 

INTR^iDVCTlON 
TO THE SECOND VOLUME. 

Having in the former volume comprised all the Domaind Ae^ikiitial 
which may be called Sufastaptial^ as depen^ng upon thft pre- 
dominant substance, under various modes of combination, it 
is now necessary to enter on another field, that of the Acci- 
dential Rocks, wluch 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 wall necesdary to adopt new denomi- New 
nations. Even the Domains now become what might he^ 
called Domink>ns in the juitural kingdom, as they no longer 
imply the preponderant or predominant substance, but grand 
^visions arising ih>m natural accidences, as the Volcanic and 
Decomposed Rocks. 

But while the term Domidn 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 
from the very essence of th^ subject discussed, the subdivi* 
sions themselves became, so to speak, accidential and arbi- 

* Plinj has ruOurt^ accidentia; Gcero accidentia for rti aUrihutm, Acd- 
deuce it here used in coDtndiitiAction to accident, which, in common Engruh, 
impCei • nonl etent m ineident, not tn Kcidentd c i it um tuiicc is mCure. 
Affirtw>ctfah«ig>iMt«ilcMi»lty,tni4»e«itipwttdliw^ 

TOL. IX. a 



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1 t|i IMTROAUCTION. 

traiy. The only idea that aMfe was to select tenns that^ 
^ might indicate 8ubdi#B^n8 of the Domains, and still, if pos- 
sible, pi^esenre some relation with chemistry, upon which the 
whole science of -minei^logy ultimately depends. In Egypt, 
• uniyenally known to have been the parent country of che- 
mistry, the small proTinces or idistiicts were distafiguishet by 
Nome. an appellation which, the Greeks have translated Nomxs^ 
from a word simply implyiq[g^ divisions. But the word may 
be said to have remained sacred to Egypt, not having been 
transferred to the provinces o£.'any other country. This 
w%pd had also, the advantage of subdivisions easy to the me- 
^^g^^l^ mory, .^i Hyponome and Micronome, implying greater and 
lesser subdivisions of the Nome. 
Su^ were the reasons for the preference of this arbitrary 
. term to any other arbitrary ternij 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 less objectionable $ at least, though the plan has 
been deeply reconsidered for many years^.none such has arisen 
to the author: but perhaps candid disquisition, and literary 
collision, may produce some mors, appropriate appellation^ 
Jxich he would be the first to adopt, having no view but the 
avancement of the science* Evea: in lithology and metal- 
logy, Nomes will be found preferable to the Grovgps or Fa- 
milies of the Wenerians, denominations chiefly belonging J|l 
animated nature ; and the clear metallic divisions of Tho^Pr 
son, Alloys, Sulphurets, Qxyds, and Salts, may well be styled 
Nomes f for the term being arbitrary there can be no ob* 
jection to its occasional introduction even under Domains 
which are substantial. 
Tmu some- Above all it must not be f<)|fgotten, that itf no sdenceiy 
except those that are mathematical, can the terms admit 
mathematical precision. In the other kingdoms of natural 
history it is well known that disputes frequently s^rise whe- 
ther a new object form a genus, a species, or a vwApty. 
How much more vague, therefor^ must be the^lai^age pf 
mineralogy, whieh doponds on tiie infinitfr aandiflffatifiyia of 



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mKcapOTtovi .- 

\\\f\ laiUiiiil lirtwli r<iAi|! Hw liiiill 1 urilih I 

globe? Iiii|pt«MdwithtMrideB,FMrtnliMf^^ ^ 

Um lot amfigenexit ■ thst whidi k tlw moBt-kli^ h&mme 
pretended |irecUioift wc«Jd in iftsdft be a ndiod error? Ibr 
aetore i» not regnbr, but flwe ,- end it beeoinei pert of tb^F 
p«ribelie4kf a tystem to partake ef tbet ftecdom. IVaex^ 
paot, tberefiore, matbematieal exacftesB^ or tnetapbyaicid 
acutenetti in tbe arrangement and i^mnenclateTe of nafeonl 
history^ would be foralgtt to tfte ynry natoro of Ae adenoa 
ita^f ; akkd tf-erirn the mtet preeisa and matbeinatfcal tenai 
could be fbundi they would be imjnroper in VBatmmkfgf, 
when the aebatancea themaelTea are InaocmatejjMH tbe 
diviaions are mutually interadngled, and graduMHto each 
other. In the SnbstanHal I>oniaina e^en compb^i^dca, aa 
granite> ftc. itft equally steple with aome aafaataneea regaided 
aa homogeDoaa; anA'amaiagdite, for eamide^ wID pteaent 
ae nmneroua Idgredienta. But ii» the Suhatawtiii Doaaaina 
the Modes are variations of the iame 8ah((ance, and natundly 
IM|»w each other^ while the Nomea are ooaspoiiiidi wholly 
diflbrent in themsdves^ and connect detached snbatanoea in 
an arrangement totally Atlnct In the fiirmercaae the 
tcniaB themselves may be regarded aa deBidlioha, i^riiich ia a 
gfeatadvaiitageinanfaclence; while the Nomas must, fkUi 
tiie very natm« of the aoliject* be conaiderad as. aibatimry 
divfsiona fbr the sake of memory. In Ahis point of view e 
agfstem ma^r be compared to a caUnet) and if each aubataace 
can find iis jpoper dmwer and place> the object of uftilliy and 
deamess are answered. But atiihe same time every system^ 
afven the Newtonian, has its anomdiea. 

InttuB, aa in the former part, it became a chief oloeot teW w e artrtwr fc 
J nc u B Bse the nomenclature* the poverty of which has loiig 
bean regretted by Saussore^ and other able authors. Buihn 
pwmn ta aoaae uaeftd obaervations.on this topks. ^'Henhaie 
begun with giving di£ferent names to things which have ap 
peered to theaa cleaily4lstinet ; and a^ the same time they 
favve teBsed ganaral iH^jbinimiliMPa for olgecta v^eh aaemed 
to tca^bk each other. Jnioog savages, and in dl new kn- 

a2 



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^ nrtKODoprioir. 

gaagtB, the names ate almott alfjjgrs genenl* thatk to say, 
^ Tague expressions for Directs of the same similitude, however 
distjuKt An oak, a beech, a linden, a yew, a pine, a fir» 
wilm'at first be called % tree; then the oak, the beech, the 
^^bideb, will all be called oaks, till they be distinguished from 
the others, which will be called pines. But parti(^Cdar nauM 
will only be found in as advanced state of society, after com- 
parisons and examinations; and the number has been always 
mcreased in proportion as nature is move studied and better 
known; and the more it is examined and compaied, the 
morMJmtOElant will be the proper names and peculiar deno- 
minilR^ . But when we are now presented with general 
term/vmi^ genera, it is to send us bdck 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 ; and we are never afraid 

Ojio augment the number of particular depomjtnations wheal 
^e wish to designatigrdifferent objects.*' 

This eloquent author was, however, too inimical to syst^s 

of nomenclature on the Linnaean plan; and his 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 

Bivyli j8 Haiiy, but even he has been obliged repeatedly to change 

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

^ second only species; in the third there are two orders; in ! 

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

■ ' • as already stated, he has changed the very foundation of hiii 

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 

* His trguioent that cryttali Nieable the Hiawcn of plant*, at a criterion of 
epedes, it not jwt, the ciTttah bebg often diil^t from the inbtUm, ^iMvtx 
in ItfMitone, bai^ftea in giamte, &c. S(C. * 



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INTRdDVCTIOm 

the ingeiuoiu crystaOogiBt Roni6 de Ltsk} and formed the 
foondation of the singular production of Dolomieu ^the 
liineralogical Specie8> in which he goes so &r as tol^pert 
that this qiedes can propagate itself; This nugatory propo^. 
qltion seeiBs merely to have been advanced, because ^ allows 
that without this quality no species in natural history can 
exist. Let it not be imagined that su^ observations, es* 
torted merely by the impulse of truth, are intended to violats 
the respect du» to those great writers in other departments 
of the 8ci«nce, which is sufficiently wide ibr the detdoDement 
'of rariotA talents^ and though the eagle requires j|Hhole 
province of rocks ibr his immediate dnnain, theie V^phk 
science ample space for invention and ability, withdnt eniAfy 
and without enrf* 



Jt is hoped that the nature of the several domains oon<- , ^ 

tiSied in this volume will be found to be ftuffidently illustrated 
by the observations at the head of these divisions. One of 
the most important, in every point of view, is the Vctamic, ^^^S!SS|* 
an object of ludicrous neglect and contempt to the German 
mineralogists, whose confined ideas have been the* more im- 
plicitly followed, because^ Genq^ are the Isthers of mo« 
€1 mineralogy. It will here be found to be treated with 
details, and it i^ hoped with the accuracy, which the sub- 
deserved, not only from its own importance, and contra- 
distinction from alitiieother domains, but on account of the ^ 
infinite contestations which have arisen on this topic among 
the most eminent writers in the sdenoe. ]>i£Sdent, however, Jf} 

of his own ideas, it gave t^ author singular satii&ction 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 
ixf our weekly journals*. 



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XNTEOX>OCTIO«» 

pr.Jdayjp^s ^' ^^ ^^ ooaduding lectnie^ Dr. Davy ttatedj that the 
emi^ii of kva from ▼olcanoes was one of tbQ princi|Ml 
ope^Pkona by which nature lupplied the waste tfTocksj aod 
the destruction of the land noticed in his former leeturee* 
The agency of volcanoes in the production of islands, ai¥l the ' 
increase of ^tinents, is more ext^nsive^ than those who 
reside at a distanceftmn their influence are disposed to admit 
Proofa of this may be traced in the islands and shores of the 
Mediteni|neui> in the continent of America* and in Asia^ 
and in othfr parts of the gbbe. Nearly the whole of Sicily^ 
andttstoouthem parts of Italy and Fruice, ofkr etidenos of 
thei^fAanic origin; and Rottie^ which has by ancient writers 
bMi proudly itftyled the " Eternal aty/' is buiit on the crater 
of an extinct volcano. The phenomena attending the erup- 
tion of volcanoes were described from Hamilton, Dolomfeiu " 
\, and others, who had been present during the 
iptions of Etna airit^^^^^^^* 

f^'The convulsam of the solid gnmnd, the lofty columns of 
I, smoke, and vapom*, the tremendous explosioiis, the 
tomnts of rain, and the thunder and lightning, which ao> 
company the eruption of hnra, all indicate tint the jgjimediate 
cane is tbe expansioii of stesm and hydrogen gas» which in* 
iaases. when in contact with the atmo8[diere. The doctrina 
of a centrsl fixe was unsupported 6y proof or analej^: did' 
such a fire atht its eifects must be felt at the surlhoe, evea 
if it had to pass through the most impeafiect ooDducters ist- 
heat. 
^ ^ To ascertain theicause whidi produced tlfa expansion o£ 

VQKmr, and the other phenomena of volcanoes, we must 
^JL examine the products of these august operatikmB of Natuial 

^ Chemistry. If we oh8erve.a firs.at a distance, and are^abla 

to collect its products, we may thence determine the nature 
of the substances which have been in a state of cooabustioii; 
The products of volcanoes are hydrogen gasi, vapour, and 
lava, of which lava is a compound of the earths, the alkalies,, 
and the oxyd of iron^— In his ftnaer lectures^ Dr. Steyy ob-> - 



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4etY«d> ttei lie had rtateitiie diaofyvwy of t^ 

Of tlie ggtliB umI the alkalies, —d that t be mrtria obUined 

firona tliem Wflpm a high degne inflanunaUe when 1% 

came in* contact with vaiorw*-Dr. Davy fiirther obeerredlt 

thai pceriCMis to the era|itki%of vclaaDA0, the lakn and 

apfiags in their ni^ghboiirtMM)mi>ere loiown to q^ 

diaai^pearcd; andaliUiefQlcanoeswtuehai^ia activity are in 

the neighbourliood of the Ma* «r of tayo kdsea*« Now if 

we atdmit that thiMeeMfaBexwt under (he nute^ iaa me* ^ 

tsdilc atate, the access of ;miter to them would yaoyn thg^ ^ 

oomftmsfioiL The oxyg«n would he ahsotbedj and 

menaexndttme of hydra^n gas*wo«]d he produced* wlj 

alwnys foond to follow the enipdon of flamei^ Thia 

plaatftion of the canse of vdoaoaea may be conwidqed aa a 

reamfyble infittenoe from the dieoovery of the sMtallic natnra 

of the earths^ and if we adiait the operation fd electrical 

i^eiiey intheglobe, weabaUhaveacaueeBiKwratiagby whidi f^ A 

the eavths may be veatored Uf theur metallic ferm. llmi tha 

process q|renonition and decay will be eowfantly balanriiig 

eaeh oilier, and nqtare be pfeserred in a st«te of etenad 

yoirth. Ite •Pp4M|^ ^ ^ Anrota Bctealia and th^ 

Aurora Anstralis, rtMer it probable that the pake are la 

two ^ffoent fltotes of electjri4||r> and that a eonatant dfpa* 

Jatlon oHketiic powar k taking pb^ 

^"ThfTilp FT Vt^ n-^-* -^1 ^Tp ^hw Irr firrn^fc Ft ITn i] 
aattl be was not indmed to admit that the proper and se* 
condar^icecks wcfethoa prodooed. Die ciyi^ th^ contain 
aioiM eiW i tfeainthos^caerftiqndinlava. Thefspwiaamte 
of Sir James Hall wUch had been thoi«ht to eataUish the 
voknase nstwe of basalt^ he oonaidared aa defeelive. la 
basalt,' honihlmde and Mspir aie distinct]^ annrti^^ 
thwfiBuadbasaKfc which had skwly coaled, thottgh it had th^ 
fi»m of basdtic prisma, iSd not contain honfalends «r Mspv 
in dJstinct" crystals* 




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* ' * * •» ' ' 

'' Mr. Watt liaERiqg Aued a large quantity of bank, in tto 
centre of the mass which was slowly ooded^he cryBtab of 
^ basalt were large 5 bat they grew less as th^iJ|>prDached tba 

%**-*^ surface, which was amorphotis and ritrified. 

' • ^ " The la}A emftted from volcanoes is speedily jdecompoied 

^ '-'i by the actaiiii of moisture and the atmosphere, and forms the 

most itertile soils. No countries are more producthre thask 
those in the vicinity of volcanoes, if below the line of per* 
tual snow. The volcanic island of Sanlorin, which wm 
L th^'/^rchipelago in one night, in the year 1770, is 
part covered with a hunirkmt vegetation, and no 
ccmntry in £urope is more productive than the Iowbf deoli* 
vitiesofEtiia. 
^>: *' The operations of nature are on a scale too extended to 

be measured by days or yean : they require ages to ]^l|oduoe 
their AiU effect What af^iears destructive and desolating at 
the Weal view, is found m a niore comprehensive eiaminatien 
to be attended with permanent advantage. The lava and the 
^ ' jBshes which burned Herculaneum and Pompeia, ^ve fiir- ' 

, nished abundant harvests for fifteen centuries. The evHs 
that nature inflicts are transient, but ^eAbenefits are of last* 
ing duration." ^ 

it is unnecessary to warn tli^ reader that this extract is not 
from the hand of the excellent author, and that of course it 
is only t^fteneral current of the ideas whidb deserves atten- 
tion. But as the Germans have too nmch restricted, or 
rather annihiated> the infloence of volcanoes, it seems here 
Spaceof to be rather too much enkiged : for if we suppose two hua* 
^^1^^^ dred existing volcanoes, and oompoia the medium of their 
i- agency at thirty mile^ each, the amount will be six thousand 

eqiiare mile^i or at the most equal to the island of Sicily, 
dbout seven thousand two hundred. But tiie extinct vcd- 
eanoes would probiabty n)ore than double this extent; and it 
seems certain that in the chaotic and ancient state of the 
globe, before the component substances had acquired tlMtf^ 



preamt solidity and temperature, numer9aa.volcanoes 
have existed, wipch have b^en' totally tidifpdic^f 



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guislied> wli3e in niodern times perfa§yp^ OB^tws reHeuMm 

mboUj new h«:v€ appeared, that of Jorallo> 'in New Spain, 

and that of GBkhmra, under the peak of Teneriife. The in* ^^ 

flaence of heat in the chaotic state of the world is well ex* Cfautie ^HLk' 

|4ttned by an able though anrnTOKNisairthor. ^ ^ 9 ^ 

'' Incessant andFinfinite motions must have existed in chaos, j|Ki 

from the universal operation of endless varieties of unsaCu^ ,- 

rated attractions and repfulBMSk In those w§m iQetoationB, ^ 

therefore, of unSCnsff ineermin^lecl and heterogenous par- .^ ^ 

tictes, quai^|iCJe9 j)£sessing everj order and degiae of affinify 
must Aave oome within their mutual spherss of attiactioB. 
Tike wodttr aflfinitips must have been overpowered by the 
stronger ; and thus, in the process of time, inunense quanti- ^ 
.ties^of uniform qoiescent and digested masses of matter must V ^jft 

hare been produced^ and in these formations do we trace the ^^ > ^' 

first moments of oi^ganised natune. In them we find the 
origin of earths, metals, acids, alkidp^ water, and atmospheric 
air. W . f 

<« Gomhitttion, or oxygenation, is the grand and principal 
chemical process by wiiich most, if not all, such compounds ^^ ^ 

are by the new system of chemistry known to be formed ; 
9ven water itsel( so fong suf^rosed to be a simple element, is ^ r 

now proved to be the combioation of hydrogen and oxygen ^ / Tl 

by combustion. Nature every where presents prooft of the 
agencyoffTOin*her primary combinations! •.'. g% 

*' As fire has been seen to be the fint process of nature in 
the formation of digested masses out of chaos, so is water 
found to be tho great organ of arrangmg these masses in the i^ 

next operation of n^fihp, in the foimatioo of the ^heres: f^% 

and here nay I not foa- one momeat jause, to.x>bserve how « \ 

admirably tUa reconciles the contending opiiiiQito of geok>« 
gbts as to winch of these a^nts has been empbyed by na» ^ 

tore? £aeh of these sects has {nodoced innumerable argu- 
ments, ionumerable documents and instances, to prove his 
theory; and, in truth, nature abounds in appearances, in^' 
mntt^^lf^ of tb^.agency b<Wi of fire and water. Ip the de« 
monstn^tiiyMbsijoteuBweiiiilgM 



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W^ great ]iu|poiqfii]^ii|^arei we b^old the one employed ia 
^ 'Qf , the indtddiia^ eombination of subetancetf the other in the 

f" A^ genermt arrangement of the whole. We behdd the of|ptradiO» 

* ^^P^M^ ^^7 opmions of theory, ajid the diveraity of appearancee ift 
"*}^m W j^ nature, cqflKcted and harmonizang with the trathe of mo'- 

I ^ '* Nor iqust it be forgotten that our ideas of a diaotic etate^ 



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seem to be confined lo this globe <mly, instead of being ei 

least extended to our solar system. An(^tft|re conceive, with 

La Place, that the jdanetary bodies wereTOmiediby the em^ 

j^ cretion of an aeriforyn fluid, emanating fiora the son, ^vi^uch 

derives its sfdendow from the Deity, U^ Ibuntai* of lif^t, 

human imagination can never conceive^he univeraal efler* 

^^ ,^. veseence and devdopement of various vapours and (gunea, 

'^0 "^^ whieh must have appeared in the primeval universe. Rit it 

,'*• ' this and other grand ideas the prince of modem philosoirfieti 

wili ever be found to ]|ad the wa3r> having thus esjuiesBad 

N^wtonTs hims^in his immort^^^RiMCiPiA. " The vapours whiok 

f » arise from the sun, the fixed starB,^and the ta^ of comets, 

' A ||liy fall by their gravity into the atmb^iheras of the planeta, 

; where they^ may be condensed and converted into water nai 

jgu huflid gases; and afterwards by a slow h^ gradnate infe9 

j^ Ifl^ saks, and sulphurs, add tinctures, and mire, and mud, an!^ 

^ day, and sand, and atones, and corals, and other earthy sub*> 

^' .**. stances."t I^d not this eagle of intuition thus foresee the 

pneumatic chemistry ? 

|- ^^ The important geological observations of Dr. Davy on the 

' «P subjecC of volcanoea also cacdte, and may authorise, some 

# other general remarks^ the theoa^^the earib, winch vfill 

not, it is bmd, be i<tf9 wfaoUy d|iM 

' if • Sketch oft New DenmittiBtian of Nttoie, London 1810, 8V0. 

f Vapom totem qui ex Mle, et tteUis fi^ et cawii com^fmm oriontiir, 

incideie patsuot per gmviutem toaiD, in atmotphaerBs pUDetaroi^ et ibi coq- 

MAditnnn, et cooTeni in aquam et spiritiu humidos : et iubinde, per calorem len- 

' P 1*1 ^rtum, in sales, et salphara, et tincturas, et linniiD, et lotnin, et argiHaro, et 

§ y^* '^ ticnam, et hpides, et coiaDa^ et substaDtiaf alias tenestres, pavUathn migiaie. 

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lliearic^TSoleiitniiUityof the«af^'a.fl^^ ^^' 

caiae a psodigioQs evaporalioo of tke yasatvtl waten, aa w^ j 

in the UiMpi a oonet: and ia tl^e geaefal cfaaoeof tU^ X 

iolar Bpttm iome esteem it not impoasible that a aatellite ^W^ 

may have sbnidc a pknet, and bave nunrged in il^'W havQ ^i^ ^ 

been diffused over it$ while the shock may hai« piedaoed 
the refmUements of Saussuie, which he seoaos to aM^ribe to am 
extenial cause*; m which he is foUowed by Doloawtt, who 

eomperes the 8ilrat»Q|»he globe 1o the shell i>f an fggvahat. j^ -« 

tered by a squeeze of the bai||||. Scnoe recent wrilen have m M 

alaoy am ether graaxA, adopted tbie same oinnion. ^F 

As thegefiitg. in thisyeasof Newton and La Place, strength* ^^ m 

ened by many discovJKs of pneumatic chemistry, the solar- ^ ^^ 

fire most have been a prime agent in the creation, as it is V jB| ^ 

still tke chief agent of {Mreaerration, generation, and life, it . ^^ J^ 

may well be coaesived» as nature always pfopoitions the 

power to the eflEect, tint the heat was at first viokat, and ^ ^ 

gradu^y diminished to the present temperatuie. HenoQ4lhe * 

kapressions of plants, which are now tiopacal, are found in #| 

cHmatae at present tenqienite'or frigid. The doctrine cM| V ^ 

eenind heat seems now to be universally abandoned, thougl^ |L ' 

if the nmcfeua of the earth consi^ of iron> according to te j 

writers on magnetism, or of varioos metals which pass into *^^ 

earths^ amnrrting to Dr. Davy, it is diiBcnlt to conceive that 
thens should not be a cMain heat peculiarly modified, as ^9, 

another modififatioh exists in aninml lilef. If we judge^ 



4 



• De Ijotf thott^ ft Genefaoy adaiowWdge* dMt he does not andenasd *' * 

uitflrpffcititfufcMrimi. Sn iMia ^S "' " If dittiiyiMi||it from ^ffkfnemmi, jaA * '-' ^' 

in one pMige calls it vn r^findemaU en mm q wto twv. 

f The nature and wM» of heat aod light are &r from being ascertained. .^ 

Sanssnre, $ aa 4^^r egaiJirthem as different lobatanoeiy and obaervea that die 
point of the MHhpated by the bkHF-pipe, though not of a paler blue than 
the veat, je^ ^Hv<^ ^ ''*l^ ^^ ednreit gold into vapoon, and yidd the 

grcateat heat aia&ble by ait. But the appearance of li^t muat depend on ^^ 

^ degree of dadatta, vhidk no lacaDa aeem to faavn been iatented to WjL - 

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however/^m the external coi^tution, the predominant 
central substances are iron and silex^ or the metal, of silex. 
For silex itself, as already explained, is frequentl}iai new pro- 
duction, found in the straw of graminous plants and the 
bark 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*. 
^[nn*9 Ferrara's abl^ account of the volcanoes of Sicily has also 
opened some new geological ideas. In one passage he thus 
expresses himself: '* The n|tural philosopher who has ex- 
plained the formation, that is, the condensation and con8oli-> 
dation, of the globe, and the inequities of its surfiice, as 
being produced by operations arising'%t>m an innate power 
in matter, from a power most generally diffused, from a 
power to which nifturet has put no limits of action upon 
the spot which we inhabit, but at the same time destined 
to bind all the parts of the univetse together, in order 
to form a well-regulated Whole ^ in a word, by gravita- 
Jion: it would seem that he approaches nearer the veri- 
litude of causes : he does not leave the earth in order to 
Kplain the facts which are found in it; he has not crofited 
extraordinary powers ; bu]^ has attributed all the phenomena 
to agencies which still operate, although upon another scale, 
but which would renew the same phenomena, if they were 
conducted under the same circumstances. From what I have 
said it may be understood that my opinion is with those who 
1*^ ^ ^ suppose that this globe was formed of materials which, being 

first difiused in a fluid, were thence deposited successively, 
. and which occasioned all the disorder which we observe on 

^ [^ the surfhoe by the einldng of some parts, while others remain 

^^V3p elevated in their original site and leveL Burnet, who not 

^ ' long since started this grand and perh^ ancient idea, has 

• See Bunm's Ctpe of Good Hope. Brdiltk, ii. iW^mj he eonfolted 

• for the diiiolQtion of nlex, which be wyi u effected bj water impregnated with 

oktic, aoda, and sulphur in a state of taponr. Kirwai^|||L 155, sajs, ozyd of 
, ** ^- 1 iron with nuaoeotmic salt yields a pak green glass, that is^tiliceous substance. 



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been fbUomd hyamny natural phSosoiAen Who bave given ^ 

it aU possible cxtcnabn, aff, fiwn physical truths and exacfrj <J^| 

observaticms, have conducted this theory to a degree o£ verity ^ 

simiUtude of which the others are not capable. I adopt it, M 

not only afe it appears to me the most consonant to the 

theorems of natural phUosophy^ but as I find it most proper f^ ^ 

to give the most natural and easy explanation of the &cU V-^ •** ^ ^ 

which we observe in Sicily, and which seem to add additional ^ m 

proofii to those observed iu other regions." * S . " 

Bouguer, and roan/ other naturalists, have observed, that SolMideBce. J^ 

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 depression of the poles, and many other cir- ^-^ 

cumstances well known in natural jrfukisophy, and replete a 

with innumerable vapours, and gasdf could only ac^ire iu 
present comparative soHdity by prodigious subsidences, arising 
from the gravitation of the solid and senifluid parts towaids 
the centre. TTie most prodigious of the subsidences must 
have been that which sunk two thirds of the globe to mak/^|. 
room for the present oceans^ sufficient recepj^es for the 
primeval waters, if the idea of this vast sub^l^ce can be ^ 
supported. Ferrara, arguing only on that subsidence which 
gave place to the Meditenanean, says that the mountains 
above R^pgio are veiy 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 fbllowiag passage likewise deserves observation : " Wheie 
the mountains are formed of soils in which the lavas are 
united with the calcareous masses, or, to explain myself more 
clearly, where a frontier of consolidated kva was filled from 
the bottom to the top with calcareous masses, the seiies of 
these heig^ta^ IS calcareous on the one side^ and vokanic on 



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rf|^ ^ file other. Such k tbe iiiiiQiiti|MiiM IIMM« tefmiBal^ la . 

KT *<|ie supMHit, upon wfakh ^tandir the Tillage of GsrlentuiL 

■rVp ^o suppose* with Dokmieu^ that the lava pressed through 

IPI; the Tale, whence^ risings hy the side, it arrived stt the top, 

I without haThig>paaBed to the other side* is to suppose an 

i order of thmgs which can^never have existed at the epoch 

\ Jl When the iava was fluid. In &ct* this division does not exist 

5^ when you proceed towuds the west* above Lentini, where 

^ the lavas cover all parts* that ib, th« volcanic stratum covers 

.^ft' an that extent. The same phen<Hnena are observable in the 

l|. ' mountains of Oanzaria* near Vizzini* and in some which are 

in the plain of Marineo* beyond LJeodia. In all these strati* 
; iM^ ftmn mountaina the position of the strata of similar niaftnals 

^ 4ft V 4 * corresponds fiom one mountain to another ; a drcuawtanoe 

im^' ^ ^ K, . which may be estimated^ the eye* where the breadth of the 

J^ Galleys is not too gresft. Thb circumstance demonstrates the 

j^m diaraoter of the revdlutions wliich have produced these in«* 

I ^ equalities.** * He afterwards proceeds to state the sinking of 

gi . ^1 '\\ ' i pi^ of a mountain in 1636* and the catastrophe fdilch 

• ^ W^ happened at Nieosia about 1750* when a fourth part of the 

^ eity* with tJIfcconvent and churches of the Oipucfains* sunk 

in one dafBb that nothing could be seen but the tops of 
the buildings* and of the trees; but the people eseaped by 
' .' . ' V, stepping out of the windows. In 1740 the town of Salemi 

suflfbred the same misfortune ; and in IT96 some lands sunk 
near S. Maria di Niscemi. He also states that the people of 
^ a piaoe* a few miles to the west of Catania* thirteen years ago . 

emikl only see the top of the cupola of the Benedictine mo- 
nastery cf that dty, the prospect having been impeded by 
^ the lava of 1669* but now the entire cupola is seen* the 

ML chalky soil under the lava having subsided f. 

1^ ^ Perhaps this doctrine of subsidence might of itself explain 

' ^ the inequafities and other phenomena of the earth's sur&ce* 

without having recourae to any concussion of a satellite or 
other body. ^ The smnmits of basalt* and the capa of lime- 



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iirfKoDvCYiofr. • 'X9 

«tfme> in Hie tpfAese, i}iglit perteps ^ otpkiiied in tids h; 

BMiailer^ and we are at least certaiii that the d^j^ exMa. 
fiat it is fiur horn the intenddii of this work to propoae'or 
support any theory; and these lemaxlts m||^ontf*'tM^ reminded 
as a ihw scattered hints which may intdHtlie reader. 

Phd> i%<wlial he calk a new theory ^m& earth, supposes PSn?is3fitan. 
a nudena surrounded with a fluid zone> whkh contuined the 
elements of the various substances 3 and he imagines the \ 

efltos and variations to hafe been veiy prompt and sudden, ^ ; ■ 

Diwing to the extreme rapidity of the rotation of the earth. "fy 

He sffguesibr a fbrmationwhoOy aqueous; but his chief new ^ 

fiiet seems to be a granitic mountain at Gana, in Austrian 
Lombardy, which is throughout full of cavities, a few incl&s 4k^^ 

distant from each other, and lined with crystals of quartz and -^ ^^ #!^P 

The chief features of De Luc's new system of jpiplogy De Lac's. f/ 

seem to be the following. He supposes that during the 
deluge the former continents disappeared; but this is dearly 
6stftrary to the Mosaic account of paradise, and the whole '■ 
scriptural narrative, lyhich represents the land as stable and 
unalterable^ That successive catastrophes' aibcted the beds 
of our continents, even while they were rising under the 
waters by chemical jiidpitations, being occasioned by caverns 
which formed undet.]pem. That valleys, lakes, abrupt pre- \j^- ^r% 
cipices, existed at the birth of our continents, in consequence 
of those catastrophes by which the beds were ndned. That 
stony masses and gravd, which aie scattered in such great 
quantities upon the continents, 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 lai^ 
blocks, caused by th» attrition of fragments, have been ex- 
pelled from the interior by expansive fluids, during the sub- ^ ^ , 7 
aidence of the beds, and dispersed at the same time at the ^ 
bottom of the sea. That the precipices towards^ the sea have 
not been produced by the sea itsdf, bat are oiigjuBid featuresp 

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&^ resulting from the rupture of the beds^ ftt the time of the 

vast subAjfence which sunk the former continents^ and pro- 
duced the new concavity of thi» ocean. 
These th^ries d^ be compared with the Wernerian and 

I Huttonian^ tod tlV»f Ferrara, founded^ as he says, on that 
J of Burnett The rocks having been hitherto considered as 

II * the chief province of the geologist, it is hoped tbesL* few eur^ 
'^\ ' ' sory remarks will not be found foreign to the puipo6e* But 

Petralqgy, as already obsen'ed, haa iitUe more connexion with 
' ^ffk Geology than its sister sciences Lithology or MetaHog}! 

%k ; and, like tbem, can only be regarded as an introduction. In 

which poiat of view these observatione may not be found 
unusefiit to the student. But it is time to return to the de* 
^^ J, script ion of the AccidotiHiil Douiaiiis, an accurate knowledge 
fSr of which may be regarded as peculiarly indispensable to any 

^ yteqy)f geology, such Aieories having so often confounded 

the iflk of human science. The more humble sage will 
t ^ perhaps be contented with the knowledge of the substances 

I ^gL "4(1^ themselves, and prefer what Gibbon caUs a LXAaMSD lonf- 

>«. ^Kr EANCB to any geokigical theory. 



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DOMAIN Vlt 

COMPOSITE. 



This division comprehends the rocks ^^^l^^ 
which consist of different substances blend- 
ed together, and for which no distinct de- 
nominations have been adopted. Many 
of them have been classed under vague 
names, particularly that of granite. 

Under the division of Aggregated Rocks, OflMia^ pin. 
Gmelin, in his edition of Linnaeus, has ar- 

VOL. ii. B 



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2 OOMAIV VII. C0MP08ITB. 

ranged granite, gneiss, porphyry, amygda- 
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 
Derivative Stones; the other rocks being 
considered under the simple substances. 
Th<SS^' Daubuisson supplied Brochant with a 
short account of rocks upon the plan of 
the Wernerian geology, or, as it is called, 
geognosy, not by the most fortunate 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 to 
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. 



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duit it is theoreticy and oonsttnct^ upon 
geological ideas of the antiquity aixl fonna-^ 
tiOiiii of tile fH^ral rocks; whidi the suo 
oesBlve and general observations of fntura 
ages may perhi^s demonstrate to be only 
local, or erroneous; and Prhicb^ «ren at 
present, are very fiir from being univer-* 
sally admitted. Nay^ if they proved to 
be infallible, or uncontrovertible by any 
ftiture £icts or arguments, still the plan of 
atrangement would be improper for a truly 
scientific work, the same substances being 
repeated as prin^itive, transitive, and se>* 
oondaiy, nay, sometimes of independent 
fonnations; while, in any science, all that 
is requited is the knowledge of the object 
collected into one strong pcnnt of view« 
Hie denominations are also, as in the in-» 
stance of porphyries, so lax and vague, thkt 
the very base and nature of the substance 
are confounded, and no accurate know^^ 
ledge can sdie. In any sdence, on the 
contrary, it is necessary that the objects 
be classed, and most precisely defined, be^ 
fore even a plausible system can be oon*^ 

B 2 



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teMiklft TIL OOMl^ITB* 

fttracted: the stones must n6t only bie 
hewn out of the quarry, but most accu^ 
rately squared, before the temple can foe 
erected. But true science and liieory are 
so completely opposite, that any attempt 
to blend them has always defeated itsr ob^ 
ject 

To Mr. Jameson we are gteatly indebted 
for a more ample account of the Wemerian 
theory of rocks, which he has illustrated 
with considerable care and attention, so bb 
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 Wemerian system, nor in 
the Huttonian ; though no science can be 
called complete withoiit enumerations of 
all its objects, and in the present instance 
one neglected rock might perhaps suffice 
to overtum a theory. The greatest mis^ 
fortune in the progress of human know- 
ledge has always been, that theories have 
be^D constructed before facts have been 
observed^ The theories are indeed useful^ * 



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BOMAIK TH. COlirOBlTt. 



as diej stimulate their admirers to the ob** 
oervation of (acts; and as Werner himself 
observed to the author at Paris, a theory 
is useful to eoncatenate fects, and render 
them more clear and pleasing to an audi<^ 
ence. Nor, with the modesty of a man of 
real genius, did he conclude his own theory 
to foe unobjectionable* 

The intention of this treatise is the accu* 'Jg'JJS*!' 
rate knowledge of rocks considered in them* 
selves. As a Zoologist or a Botanist does 
not pretend to discriminaite which plants 
or animals are of early or of later creation; 
and, in the other branches of mineralogy, 
it ifi neither the situation nor antiquity of 
the gem, or the metal, that is an ofc^ct of 
the science, but the nature and name of the 
substance itself. A Gemmologist would be 
ridiculed if he could not distinguish a blue 
diamond irom a sapphire, without a previ- 
ous acquaintance whether the object came 
iiom Golconda or Pegu; and a Metallogist 
must distinguish grey silver ore from anti- 
mony, without knowing either its formation 
or site. lo the same manner 9, knowledge 



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of rocks, arising fix>m local rations, must 
alwajs be regarded as Qmpjrical, and will 
often prove wholly efroneous. That gre^t 
observer, Sausaure, found, ki, the ampW 
scene of the Alps, that he was farther it^ 
moved from the formation of ^ th<B(»ry» 
after the sedulous labour of forty year^i 
than at the beginning ; that instead of aaj 
regular plan or order, he found perpetual 
contradictions, in the assemblage and oo» 
alescence of substances, that seemed to b« 
wholly remote and dissimilar. " Jt maj 
well be affirmed," sa^s he, *? that thwe in 
pothing certain i» the Alp3, but their V9r 
riety. . , , . SometiiQes the 9kMs are qalr 
caneous, s<MQietimes magpiesiaii' Tbeceo-r 
tres and highest summits are here of mawt 
ive granite, there of a c9iIcareous iiiicaslatea 
sometimes of magnesiaA stones, 9oimetin}^ 
of gneiss : if the beds be oooaideiedf hem 
they are yertical, there horiapntal; h«rQ 
their inclination followv the dope of tho 
mountain* there quite the contrary."* Wo 
ma^ add, from more recent obfcprvatigoai 
* fsaat. 



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poxAiir vn. oftMronxm. 



tlmffcl^satmiiiti of the Pyranea areof a 
rib^y and fetid marUe ; vhile the Andes 
aift chidSy oompaied of day » and pour out 
nven of mud. When we compare these . 
grand scenes with the litUe mountains or 
hiiis of Saxony, we must regret the peiw 
verseness of &te, which has confined Wer* 
ner to such an insignificant field of observa<» 
tion. Nor can the travels of his disciples 
affect the question^ for many have changed 
their sentiments, upon their visits to Au^ 
veigne, and other volcanic countrin; and 
observations of the great master alone merit 
confidence ; fi^r we all know, from Hogarth, 
bow Richardson could read Greek thitm^ 
his son. 

These introductory observations are not 
unnecessary in passing to new and grand 
divisicms of the rocks, which have been 
blended and confounded under several 
vague deoominations, but which are here 
separated into various great assemblages, 
£oic the sake of more clear detail, and more 
accurate knowledge. 

Under the important Mode of granite, 



Praunded 

gnuntM. 



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ooMAiii vn« coMrosnrB* 



it has already been explained tlwt felspar 
and quartz, united with sklerite or mM^ 
or with both, are indispensable attributea 
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 ccmsidered as altering 
the nature of the substance. 

But the name granite has, on the con-r 
trary, by Gmelin and many other writers, 
been extended to almost every aggregation 
that can be conceived. Such heteroge- 
neous aggregations are here arranged un* 
der the name of Composite Bocks ; whUe 
some, as that beautiful rock called the Coi^ 
sican granitel, are placed among the Anor 
malous, as departing from the usual rules 
observed by nature, 

The latter six great divisions of the rocks, 
^^riSS^ being derived, not from the nature of the 
mA$tance$ themselves, but from accidtnces 
, or cironm'fitances, may be called acci-? 
DENTiAL, or circumstantial; while the 
former divisions are substantial. The 
phemical Mode therefore^ so essential ii^ 



SOMtllltiBl 



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aOHAlK Til* eOXKMlTB* 



Hie sctbstaoitial rankB, hare becomes foreign 
to the object ; and the terms Stmcture and 
A^ect^ derived from the seSf-^tpparent na-- 
tvre of the stones themselves, would b^ 
come jet more improper, as by far the 
greater part of these rocks are even com* 
pounded of various domains, united in one 
mass. 

The term Domain has been retained, n^I 
not in its former acceptation, which may 
strictly imply the preponderance or pre^ 
dominance of a particular earth 6r 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 or preponderance, being of 
a secondary and subsidiary nature, and 
only a further recommendation of its pro^ 
priety. 

But the term Mode implying the clie^ 
mical mode of coinbination, which is evei) 



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10 moMMtm vn* c^mtobits* 

more essential than the nature and power 
of the substances combined, as appeaH 
from an infinite number of analyses, it can-* 
not be admitted into these new divisions* 
derived from accidentia!, and not firom sub* 
stantial, differences, as has been just men- 
tioned ; and the inferior terms being equally 
objectionable, the adoption of a new appeJU 
lation becomes indispensable. The word 
jfune. NoMB has been adopted, as short and con^ 
venient, and as applied by the Greek 
writers to the districts of Egypt, the first 
country where chemistry and mineralogy 
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 presents 
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 fruits 

* The word in all its leUlioiu Boems strictly Oieek« and is pro* 
babiy only a translation of a Coptic word, especially as Strabo ia« 
forms us that the Nomes were divided into Toparchies. 



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KOMx I. wwKMtm, WNTtt OAUonr mocK. | ] 

in a vase of crystal: but when a science 
kas assumed a new aspecl, like chemistry, 
or is wholly new> like mioeralQgy, 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 different parts of 
the same rode. Aftcnr these coosidemtictos, 
Ae proper arfaDgemeot of the Composite 
Rocks will not be attended with much 
difficulty. 



HOME I. SIDERITE, WITH GARNET ROCK. 

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 i but both are so equally bitlanced, 
that it would be improper to class them under 
either Mode. 



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IS DOMAIN VII. COMPOSITB. 

• ' '^ 

HTFONOMB I. 

Garnet, in a base of siderite. 

HTFONOMB II« 

Siderite, in a base of garnet 

Siderite, with garnet rock, from Scotland. 
The 3ame) fron) Sweden. 



NOME II. SIDERITE, FELSPAR, GRAPHITE; 

A little chain of rockfl, amidst the etema) 
snows of Mont Blanc, conusts of laminar black 
qr green svieriteit felspar* ^nd grp.phit;e, with 4 
little quartz and mica*, 



NOMEm. SIDERITE, UNCTUOUS QUART% 
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 t* 

» Sauss. |g74. t lb. 911. 



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OOIUIM Til. COMPOSITS. 19 



NOME IV. porphyry; WITH CHALCE- 
DONY. 

The green porphyry, in particnlar, sometimes 
appears spotted with chalcedony, so as to as- 
sume 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 
kU a prey to barbarians. 



NOlfE V. JASPER, WITH AGATE AN© 
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 
beautiiul polish, and is found at Monte Rufele, 
in the Volterranof. 

* In the noUe collection of Beaton^ at Pam, iStmt is a specimen 
jotned with pore timnsparent cparts^ which had probably passed as 
m Tetn throng the rock. 

t Gabbctto I^izareno* Bonia I7g2, 9 vok Sro. ii. f$9. 



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14 M^ujum ru. coBumtr* 



TSOKE YI MICA AND ACmrOTE. 

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



NOMEVn. ACTINOTfi, SIDERTTE, MICA. 

A composite rock of delphinite or actinot^ 
greenish siderite, felspar, and white mico^ all in. 
little grains or plates^. 



NOME VIII. QUARTZ, SIDERITE, OXY0 
OF IRON. 

A rock> composed of quartz^ siderite, roica» 
and cocyd of iron ; together with a tabular feU 
spar, which he calls aanidine^ a substance in silk j 
tufts, which he calls desmine, and another resem*> 
bling spi;iel, which he calls spinelan^ was dis- 
covered by Nose on the banks of the lake of 
Laach, near Andernach. See his mineralogy of 
the mountains ol the Rhine, quoted in the Jour^ 

• SbUS6. § 1293. 



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IVMIBt IXj s, mi. IS 

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



NOME IX. QUAKTZ, SCHORL, AND LIME- 
STONE. 

This composition appears in the infinite ya- 
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 npiagnesian 
rocks. 



NOME XI. FELSPAR, QUARTZ, GAENEIS. 

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



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iC bOUMW VII. COMfOSITB. 



NOME Xn. FEUSPAR, QUARTZ, TALC. 

This noble rock contains plates of splendid 
talC) varying in size from half an inch to many 
feet in diameter. It chiefly occurs in the Ura- 
lian mountains, whence talc has sometimes been 
cdled Muscovy glass. 



NOME XIU. FEUSPAR, nBROUS SIDERTTE. 

A rock in confused veins of felspar, white 
mica, and green fibrous siderite*. 



NOME XIV. FELSPAR, CAIXJAREOUS 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, andactinote; 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. 

• Sanai. § 1369. 



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DOMAIH rtf. COMFOBITB. 1/ 



NOME XV. JAD, SCHORL, GARNETS. 

A rode, which Sansaure calls a mixtuije of 
jad» sparry tchori, and massive garnet It takes 
a fine polish, and its large spots of red^ green, 
and yellour, form a beautiful effect*. 



NOMEXVL GRANITE AND CHALCEDONY. 

Chalcedony was chiefly found in amygdalites, . 
and by some supposed to be of volcanic origin. 
Saussuref discovered this curious and important 
rock near the city of Vienne, in Dauphiny. 
On examining the stones employed in building 
a peasant's cottage, he was astonished tp find 
that most of them were elegant chalcedonies, 
more or less translucent, and mingled with leaves 
of a beautiful yellow pyrites. Observing that 
granite adhered to many of these fragments, 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* 
▼doped in that substance. The most common 

• § 145. t § 1634. 

VOL. JI. C 



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lH oojiAiM VII. coHtouram 

colour of the chalcedony is ablubh grey; but it 
also appears of a yellowish white, and often co- 
vered with fermginoiis rust. Sometimes there 
are zones, concentric and in festoons, of a paler 
eolour. The fracture is Tarious, sometimes uni- 
forms sometitnes scaly, sometimes a little con- 
choidals and its hardness is such that the file 
cannpt touch it. It is coeval with the granite, 
for nodules of granite may be found in the chal- 
cedony, as well as the contrary. These granitic 
nodules contain veiy little mica, but abmidank 
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 six 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 plate, of 
a 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 fracture*. 

• ^ 8Mi9rare slforwaids iiisc<M^ewd abotWacK* of blial0oA|i^ ia 

the granites and gneiss of the plains, and particularly in* the ancient 
Bourbonnois. S«q lonie ?. p. xL 



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HOMB STII* «UM1XB» WI7B OAXNETt. J9 

In a sobseqnent journey Sanssnre also dis- 
covered gneiss^ its thin leayes alternating with 
thicker or thiimer leaves of cha^cedoajr, 

UYMNOlIB I. 

Chalcedony in granite. 

BTPONOMB II. 

Nodules of granite in chalcedony. 

JUicranome 1. Gneiss, altemadng with chaloe* 
dony. 



NOME xyn. oRAirrrs, with schorl 

AND GARMETS. 

A granite^ from Bamfshire^ Scotland^ of red 
felspar^ and bluish fat quartz in large grains^ 
broad plates of micard of a brilliant yellow, with 
black schorl in prisms of four lines in diameter. 
There are also patches of garnets. 



c 2 



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so HOMAIN V1I« C0ilP0ftITE» 



NOMEXVin. GRANrnSANDLrME-STONE: 

This mixture, Ii)^e most ofthe otherS) appean 
in the Alps. 

HTPOMOMB I. 

Granite, with lime-stone. 

Microname i. Gnebs, with lime*stone* 



NOME XIX. GRANITE AND SLATB. 

Slate, by some called argillaceoiis schistus, is 
sometimes found blended with granite, though 
in general it rather seems to form a distinct line; 
and It commonly rests on granite, as being of a 
vdMof more recent formation. The veins of granite 
that run through date have afforded matter of 
discussion to various theorists, who thence argue 
that the granite is of more recent formation, or 
at least that they are both coeval It has been 
affirmed by some, that what is called granite, 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 



gniiiteui 



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mnwiLs* 



HOM^XIX. OltANITB AVD llAtB. Si 

of qQite 8 new formation hsvebeen indicated bj 
Sanssure^. In describing the mountains which 
bonnd on the north- west tlie TvUey of Vahmine^ 
he mentions that he found a nonntain oocnposed 
of his rodie de corncy which is sometimes basalt* 
generaHy . ba^altin5 sometimes basanile, some^ 
times nagnesian basadtin^ here called Sanssurite; 
and sotDetimes a coarse slate, or argSaceous 
sefaistas, which seems hete to be the casef. 
f^ On observing this roche de come in the q>ots 
whare it coalesced with the granke^ I saw veins 
of different breadths filled with a granite, which 
was fonnM and moulded in their interior. Thi 
largest of these veins is about .^ree feet in 
fcrcfadth, cutting at H^ angles the planes of -the 
layers of the^ rock, which it traverses; imd the 
uncovered part abov^ the rest is about seven or 
eight teet in length. The, sides of this vein are 
regular and parallel. . The granite wh&h fills 
this vein is composed, Hte that of the mountajd 
to virhiph it adheres, of grey quartz, whitie fel- 
spar, atad brilliant grey ;inica. This granite 
presents Utde even slits or s^ams, rather' indi- 
cated than real, crossingf each otherMn different 
directions ; which seems the effect of a begin<> 

t The comeut ^ali$ ofWallerioi is hotablende slate) or slaty 
nderite. * 



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Bing rec686; and which show the teadettcy, 
commoa in this sort of stone^ to divfde itMlf into 
fragniouts of ev^n tiflM* 

*' Ahore and beneath this rein there are othen 
more tuutow^ one in parCicnlar^ whith is not 
above half an inch in brea d t h^ and is prolongedy 
like the former^ for a space of seven or eight 
fwt. Some of the little veins show that the 
beds of the ntcAe de came have siibsidedt or sunk 
unequally^ since the granite penetrated inboat; 
for ^ey seem to be suddenly intermpted> and to 
begin anew a little higher or a little lower. The 
broadest vein seems also to have yielded a little 
in some parts. 

^^ These veins of gramte^ which were then 
new to me, appear to throw light on the formal 
lion of that stone. For to any man a litUe 
rersed in mineralogy, it is almost demonstrable 
that this granite has been formed in these veins, 
by mere filtration of the waters* which, in de- 
scending from the mountain of granite, which 
hangs over these schistose rocks j brought down 
the elements of that moiiptain, wHioh they de^ 
posited and crystallised in these fissnies. When 
one finds the slits of a marble, or of a slate, filled 
with spar or quartz, one decides, without hesi- 
tation, that these foreign bodies, or parasitical, 
as Linnaeus calls them, have been bi»ugbt by 



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NOUS XIX. OXAXITB AMO iLATB. §3 



the wi te ifl , and crysUUiacd in these sKts. Since 
then the elements of granite are all papabla of 
hnmid orystaUisation, why, as the circumstances 
are the same, sbonid one hesitate to acknow* 
ledge, that it has been also dissolved and crys* 
tailised through the mediom of water? 

<* I thonght then that I had made a great step 
towards the knowledge of the fomatton of gnif* 
Aite, when I saw with so much cleamiess that 
nature eonld form it by the mere assistance ci 
water. My only regret was, that the proof of 
thii troth was concealed in the centre of the 
Alps, in a spot so little accessible to the greater 
part of the lovers of lithology. > 

<^ But I had, towards, the end of tlie same 
year, the pleasure of finding the phenomenon i» 
a place w^ frequented, and of ea^ access, 
fiiiee it is at the foot of the walls of the city of 
X^ons^ If, without the gate of the Bed Cross, 
you descend to the Saone, by a path which runs 
under Uie walls of the city, you will see on the 
right, a little beneath the fort of St. John, banks 
of sMid, the sides of which are open to the air. 
Under these sands are schistose rocks, composed 
of white -qaarte and brilliant mica, sometimes 
red, sometimes blackish. The layers are almost 
perpendicular to the horizon, for they form with 



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S4 - DOUAIM VII. COMVOim. 

it an angle of HO degrees .indioiog.towaida Ihe 
we»tf and ruoning from norAh to soixthi 

*^Theiie I found ayein.of granite 21 mchas 
in breadth^ and .uncorered for a length - of abont 
18 feeU. This!mn» of which the sides are pa* 
rallel, traverses the layers of schistose. roak^ un* 
der an angle of dO degrees, and forms with the 
horizon tan angle of .50 degrees, with, the same 
inclination as the layers. The granite which 
formSf this vein ha^ shrunk, like that of ValoT'* 
sine, with sbme rectilinear fissures, which cr«s8 
each other inregulariy. There are se^n in the 
same rockjother veins of granite, of a less oon- 
siderable size, the largest being parallel to that 
which I have described, while, the others ron^in 
^a obU^ue direction. 

. *' I observed similar veins in the schistose 
tack, at the foot of the wall of the city, and 
under, the path which accompanies that wallr 
One of theiri, about fourteen inches in breadth, 
is perpendicular to the horizon, like the layers 
of the rock. . It passes under the wall, and must 
enter into the city. . Near theSaone^ and within 
the city, is a quarry of. granite, which was 
wrought at the time I made my observationa. 

^' In fine, I made at ScAiur, in Auxois, an ob« 
servation ^analogous to the preceding, and which 



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eonfinns the same treth that granite niaj be 
formed in the water5 by the sarndtaaeoM orj^ 
tallisation of two or three kinds of stooe. The 
gnmite rook, on which this town is built, na« 
tiiraUy. dividies itself into large aaases, with 
plane or flat udes, and these masses are h^ie and 
there separated by oreyices of a eertain bwadth. 
I ficmnd in these cre?ices parcels of qnartz, &h 
spar, mid mica, mingled as in granite, but in 
far larger grains, there being bits of an almost 
tranaparent qaart2» two or three inches thick, 
traversed by leaves of mica so large that. they 
might be called talc, or Muscovy glass;, and 
the whde intermingled with large jneces of ned 
felspar, like that of the granite, and confusedly 
crystallised. It could not be doubted, on seeing 
these heaps of large crystals, that th^ are the 
produce of tl^ rain waters, which, passing 
-through tlie granite, have dissolved and carried 
down these different elements, and have depo- 
sited them in these wide crevices, wher^ they 
are crystallised, and h&ve formed n.ew stones of 
the same kind. The crystals of these new gra* 
nites are larger than those of the ancient, on 
acconnt of the repose which the waters enjoyed 
in the inside 6( these reservoirs." 
.. Such are the remarks of this, great observer, 
who proceeds to argue that granite was pri? 



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20 OOVAIV rtU OOMFOtlTB. 

ginallj formed in the anciettt ^eeaa that ooverel 
the earth ^ that it is disposed in b6d0 or* iajen^ 
tiHHigh sometimes very thick and difficult to 
discover^ e^eeiaUy as those of the lower monn^ 
tains are apt to split into fragments^ eithw rhom-* 
boidal, or at least with flat sides, which he 
ascribes chiefly to the mixture of argil in one of 
his pierres de come; and as he mentions that it 
is frequent 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, 
the most ancient ocean probably having con« 
tained no animated 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 nu 
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 wide 
fidd of observation, he simply accounts for by 
the subsidence, or shrinking, an accident oom* 
mon tcTclay; not to mention the greater soft- 
ness of the substance, which may more easily 
be worn down by the weather. Nor is it incon- 
ceivaUe, on the other hand, thi^ those, veins 



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«Mj be « MQiMt as tlteflkaMire gmitoi ikafc 
anbitamoe sMMtimes raraginto mtaural waUt, » 
in Cornwall : or, in tiie gfcat antiquity of die 
earth, the veins may han^e been fennad in a 
softer grenitic substance (more compact vdns 
and nodules being observable on a small scale), 
which afterwards wasted away, aad its place 
was supplied by the clay»siate» 

HYFONOMS 1. 

Granite in slate. 

Micromme 1. Slate in granite. 



NOME XX. GNEISS, WITH BLUE SIDE- 
RTTE. 

Near Breuil, Saussure observed a gneiss full 
of garnets, the surfiGice being incrustated with 
little crystals of a beautiful steel blue, oblong, 
irregular, opake, very brilliant, striated in the 
longest direction^ freouently 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 the^ are easily 
fusible under the blow-pipe into a shining black 
amel, attractable by the magnet, although the 



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2g DOWAfK rtU COMPOSITS. 



ori^nal ssbstaiice be not. He sdlcb, that aM 
these properties chamoterise some kinds of 
horhblmidet the only singularity of this being 
its blue and brilliant colour*. 



NOME XXI- CLAY, SPATHOSE IRON. 

A composite rock of clay^ spathose iron, and 
another sparf. 



NOME XXn. SERPENTINE, WITH LIME- 
STONE. 

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

Some of the noblest marbles, as the yerd- 
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^alcous Domain ; 
not to mention that the union is too intimate to 

• f ti74. t { 14<tf. 



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class them among the Componte Rock^* which 
are mostly only cohereat, the substances form- 
itig in distiiict aocieliciuk 

HTTOKOMB I. 

Dark green serpentine, with grey lime-stone, 
from the Pyrenees. 

Micramme 1. The sam^ with red calcareous 
spar, from the same. 



«» 



NOME XXm. IIME-STONE, WITH GAR. 
NETS. 

This cnrions mixture also chiefly occurs in 
the Pyrenees. 

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

BTPONOICB I. 

With amorphous garnet 

HTNNOia II. 

With crystallised. 



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50 DOMillf VIb G^MPOSITB. 



NOME XXIV. UME-STONE, WITH STEA- 
TITE. 

Tirey, one of the western isles of Scotland^ 
presents a white marble wtth jdlow spotsi, sop- 
posed to be steatite. 

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

BTFONOBfB I. 

Marbfe; with veins of steatite. 



HTFONOMB II. 



With spots. 



NOME XXV. LIME-STONE, WITH OLIVINE. 

Olivine, before chiefly observed in lava and 
basalt, is also found in the micaceous lime-stone 
of Mount Somma, of which Vesuvius may be 
regarded as only a portion. Breislak has, on 
this occasion, given some usc&l information 
concerning olivine and chrysolite*. 

• i. 150. 



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HOMx XXV* htmm^noHM, wijx ouvxns. 3I 

L The soft chrysolite, or asparagus-stone of OfiTmeaiid 
Werner, is a mere phophate of lime, analysed by 
Vau4|aeliQ, 

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 58, oxyd of iron 9. This is also 
the chrysolite analysed by Klaproth. 

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 specimens 
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 Somma; 
and it has been discovered in Siberia, and in the 
mountains of the Grisons. Melanite has also 
been found in the calcareous rocks of Somma. 
But the latter substance is only to be regarded 
as imbedded in the rock, and strictly belongs to 
gemmology. 



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' 4 ■ ■ ■ 



3jBi DOWAIM Vll. COMPOSITE. 



NOME XXVI. LIME-STONE, WITH ACTI- 
NOTE. 

Tfrey marble. The beautiful rose-coloured marble of Tirey 
not only contains large crystals of siderite, some^ 
times an inch and a half in length, of a black or 
very dark green colour, but numerous other 
crystals of a lighter green, which erery candid 
observer would allow to be the same substance^ 
with a slight diversity of colour. It seems now 
to be universally allowed by the most skilful 
mineralogists, that actinote is only a diversity of 
siderite, with a greater portion of magnesia, an 
earth which singularly affects the green colour. 
But this actinote must not be cojnfounded with 
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 he 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 bb Ttdiiemt cmparaH/, Buris, I8O9. 8to. Dolct 51, 55. 



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KOMB XXVU LIMB-STOMB^ WITH ACTINOTE. 33 

a substance resembling red garnets ; or perhaps 
they are only altered by the gangart^ and might 
be found upon analysis to correspond with those 
found in the lime-stone of the Pyrenees. Thus 
the singular appearance of the flint discovered 
at Menil Montant, near Paris, and which re- 
sembles pitch-stone, 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 temafkable that marbles similar to that 
of Tirey occur in Scandinavia. A northern mi- 
nendogist, Mr. Neergard, observes that there 
are, in all Sweden and Norway, only two quar- 
ries of marble which are wrought*. 

" That of Fagemich, in Sweden, is situate 
between the two little towns of Norkioping and 
Nykioping, and about thirty leagues from Stock- 
holm. It belongs at present to Mr. Eberstein 
of NorkiSping, and to Baron Unger, who pur- 
chased it from Count Gyllenberg for only 
200,000 francs, on account of its bad condition. 
This marble, which is white, with veins of green 
tsicy the fracture brilliant, began to be wrought 
aiboQt a hundred and fifty years ago, in the reign 

• Brard^ Trait£ des pierret, Paria I80|p, 8yo. ii; 444. 
VOL. II. D 



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S4 OOKAfM VII. cowfinsE. 

of Oiieen Christma. The apace wbera it is 
foiud is about 2000 &thoni8 in length, but its 
breadth is inconsiderable. They make of iiC 
tombstones^ slabs for tables^ vases for butfer» 
salt cellars, and mortars; and the sale of these 
differeot articles amounts auuiallj to abomt 
90,000 francs* There are magajdnes of it at 
Stockholm, at Gottenburg, at Gariskrona, and at 
Abo. The ttaauiu:tor|r employs about twen^ 
workmen, who rec^re each two lirres ten sons 
(about two shillings) daily; and its position is 
fine and well adapted for workiDg, as it is near 
tlie Baltic sea. 

<< The marUe^qoarry of Gfllefaeck^ in Nor* 
way, is seren leagues distant from CSiristiaoa $ 
but as the marble which it furniidies is saturated 
with a great fiumtity of pyrites, it generaDy be- 
comes decomposed in a few years; The great 
church of Frederick, at Copenhagen^ which is 
unfinished, is built with tins marble* I.l^ve 
often seen some pretty tablets of it, which coft« 
taiaed garnets^ and a green substance called ac- 
tinote." 

The Ticey marble seldom takes a fine polish. . 
PerhiqM by a mSl, or a steamhengine, and high 
friction with putty, this defiect might be reme* 
died. But granite itself seldom admits a perfect 
polish, owing, as in the Tirey marble, to the 



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mOMM XXViU MA&BLS, WITH AtBBtTOt. 35 

different hardness of. the ingredients. Besides^ 
onr artisans^ only accustomed to soft marble 
sddom possess the instruments necessary for 
hard substances; and a laudable change in the 
public taste can alone drixre them from their 
routine. 



KOUE XXVn. MARBLE, WlTH ASB^ISTOS. 

This uncdmmon mixture is found in the Py- 
renees, and» it is believed, in Sweden. 



^TPONOMB I. 

Marble, with asbestos. 

Micronome 1. Asbestos, in calcareous spar. 



D2 



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DOMAIN Vm. 

DIAMICrONIC. 



QCMffU 

olMtmtioai. 



These rocks, m 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 treatbe, like the Cryptogamia of the 
Botanists. Siderous earth, for example, 
may be found so intimately and equally 
eombined with the siliceous, that the rock 



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DOMAIN VIII. DIAMIOTOH^C. Sf 

cannot witli propriety be arranged under 
either, Tlie celebrated glazed rock, which 
Saussure observed near the monastery of 
St. Bernard, is of this description; and 
there is a specimen in the author's collec- 
Uoii. It has beeji caUed an intimate com- 
tanation of quartz and rorJie de come. 
n Most of the Derivative Rocks of Kirwan ^^^Jj""* 
pllong to tliis Domain. The name and 
idea he is said to have borrowed from 
Bergman. The aggregated stones of Kir- 
wan comprehend granite, gneiss, porphyry, 
amygdahte, sand-stone, and other sub- 
stances, visibly compounded of various 
piaterials; while his derivative stones he 
di^nguishes from aggregates by this, " that 
the associated ingredients are not visibly 
distinct, or at least require microscopes to 
render them sp/^ He adds, that a deriva^ 
tive stone may be denominated from the 
species {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 argiU 
laceous earths, form the most froqiueat 



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j)^ 90UAW VliU DIAMTCTOWie. 

combinations; while those of calcareous 
earth and magnesia are fer 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- 
ralogy, he has classed sand-stone, along 
with granite, among the aggregates. 

The appellation 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 affords almost the only example of a 
real derivative stone. And the intimate 
combinations of which Mr. Kirwan speaks 
are so far from 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 ap appendage 
to mineralogy, instead of forming a grand 
and distinct science, a rank to which its 
dignity and importance authorise it to 
aspire. 



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WOWt f. tlMtXTB> Wim ttLBX. 9§ 

The temi diamktmkj derived from 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 Domain, either from prepond* 
eiance or predominance. 

As this Domain depends especially upon 
the guidance of chemistry, it may be chosen 
to honour the names of the chief chemists, 
here arranged in chronological order, from 
the most ancient to the most modem 
times*. 



NOME L SIDERITE, WITH SILBX. 

[HsBViTE, from Hermes^ the supposed founder 
of chemistry, which certainly originated in 
Egypt] 

Of this kind is the celebrated rock abote 
mentioned, in which atoms of quartz are inti- 
«ietdy blended with atoms of siderite $ but in 

* A carioQS aoooont of the ancient chemitU, or alchcmitu, nuy 
be foond in the Rutoire de la Pkilosophie Htrmetique of Leoglel 
Onfraooy^ IMa, 174dj 3 vols. 12mo. 



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40 DOMAIK. Tin. OIAMICTOKf C. ' 

some portions, as usual in the ibOuite tariety of 
nature, the quartz will preponderate, and some- 
times the siderite. Saussuce's description is as 
follows: , . 

Giaxedrock. «« We now arrived at this singular rock, which 
formed the object of this excurrfon. Its supe- 
rior surface inclines to the east, under an angle 
of 43 degrees. It is this surface which is po- 
lished, and in so bright a manner, that it forms 
a perfect mirror. In some parts it is perfectly 
plane, so that tables might be cut from eight to 
ten feet in length, and of a proportional breadth; 
while 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 however the ground itself is white. This 
§tone is very hard, yielding abundant sparks 
under 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- 
doubtedly 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; those 

which are nearest the polished surface losing 



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VOMB II. 8IDSaiTB> WITH MICA. 4 1 

their colour under the bIow-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 * 
you will, of jasper, coloured by some particles 
of the black p/erre de come, which is found in 
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 common in crystals of quartz. 



NOME n. SIDERITE, WITH MICA. 

£D£MOCRiLiT£, from Democritus the philo- 
sopher, B. C. 480, who made many experiments 
on plants and minerals.] 

The particles of siderite are sometimes inti« 
roately blended with particles of mica. 



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4fi B^tUIir tilt. DtAMICTONlCt. 



NOME m. SIDERTTE, WITH FELSPAR- 

[FiBMiciTE> from Julius Firmicus, who floa* 
rished uDder Constantine 1. and firtt mentioiu 
michmdy* ^^ sdentiam alchemi4e^.*'] 

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



NOME IV. SIDERITE, WITH EARTHY 
FELSPAR. 

[Syn£8it£> from Synesius, one of those Greek 
philosophers, in £g7pt» who cultivated this 
science, A. D. 400.] 

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

* Matheteos iii. 15. Orotiut fint states, that Diocletian burnt 
the books of the Egyptians, 
t ill* 190* 



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MOMS T« VlftmUOlKdVt AITAA^Z. ' 48 

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



NOME V. FJERRUGINOUS QUARTZ. 

[ZoziMiTE^ from Zozimus, one of the chief 
Greek phiJosophers of Eg7pt» fv^ho wrote on al« 
chemy, A. D. 420.] 

Near Sallenche, Saussare observed a rock^ 
with protuberances^ of a lively red, like cinnai* 
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 the 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 drosSA 
on the surface of the stone ^ but when the co- 
louring part is intimately combined with this 
stone, it remains red and untouphed*. 

* Sauss. 1134. 



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44 DOMAIN VIII. DIAVICTONIC. 



NOME VI. BASALTIN, WITH EARTHY 
FELSPAR. 

[Gebrite, from Geber (Abou Moussa Gia- 
BER ben Haijam al 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 steel. In the fracture its grain appears 
a little scaly ; and if observed with a lens, it 
is found mixed with^duU grey parts. These 
parts, softer than the rest of the rock, become 
white when scraped with a knife, and are un- 
questionably ofpierre 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- 



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VOMS TIL BAti^VIV, WITS tUMMlTB. 45 

racter belongs to felspar, aod some kinds of pe« 
. trosilex; bnt as this rock has not the fractare of 
petrosilac, I think I ought to look upon it as 
the earth of nncrystallised felspar. Fragments 
of this rock are fonnd very plentifnlly spread bn 
this road. I had not time to ascend to the rocldi 
from which these fragments are detached^ but I 
do not doubt, but that these rocks are situated 
like those of /^/lerre de come, which I have de- 
scribed in the preceding paragraph. Since I 
have become acquainted with this rock, I have 
found rolled pebbles of it in the environs of Ge- 
nevas ^ true is it, that we find in proportion t^ 
what we know.*'* 



KOME vn. basalun, with sidbrtte. 

[Rhazite, from Bhazesy A. D. 900.} 

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

Basaltin, with siderite, from Saxony. 

The same^ from the Faroe Isles. 



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46 mouAin ruu Bumeroatc. 



NOME Vra. BASALTIN, WITH SILEX. 

[£b£nsinit£> from Eben Sina, or ATioetma^ 
A.Dtl020.] 

The siliceous part is generally felsite. Ba^ 
saltin sometimes passes into a more siliceous 
substance, which, in the north of Ireland^ is 
schistose^ and contains ammonites. It is supr 
posed to be a detritus of the basaltid> mixed 
with siliceous particles in the primeval waters. 



NOME IX. BASALTIN, WITH WACKEN. 

[Albehtxte, from Jlbertus Magnus, A« D. 
1220.] 

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. 



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aroms %, xi. 



NOME X. BASALTIN, WITH STEATITE. 

[Bacokitb, irom Moger Bacan^ &e grealest 
chemist of the middle ages; flourished A.D. 
1240.3 

This differs from Sanssorite^ or magnesian 
basaltiDy because the particles of steatite may 
be partly distingnished by the naked eye. If 
is found in the ide of MnHj and in some other 
countries. 

irVTONOMS p 

With steatite disseminated. 

BVFONOMB It. 

The sam^ with globules. 



NOME XI. SLATE, WITH SILEX. 

[Li;llit£^ from Raymond LuUy, AuD. 1300.] 

This kind has been described by Mr. Kir« 
wan*. Sometimes the quartz seems the most 

• i. 3Si. 



47 



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t 
48 DOMAIN Till. DIAMICTONIC. 

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



NOME XIT. SLATE, WITH MAGNESIA* 

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

This substance is commonly to be distin- 
guished by its unctuous or silky appearance. 
The magne^a sometimes assumes the form of 
small sqales^ 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 siderlte. 

HYPONOME I. 

Level. . 

BYPONOMB II. 

Undulated. 

• Kirwan i. 38«. 



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NoittK xin. kiv. 49 



NOME Xin. SLATE, WITH UME. 

[PA.Li88it£, from Bernard Palissj/y a potter 
of surprising genius and intuition, A. D* 1580^.] 

This mixture is found where the siate joins 
the lime-stone, either primitive or secondary. 

HTFONDMB I* 

Slate, containing lime. 

HTPONOMB !!• 

Lime-Stone, with particles of slate. 



NOME XIV. QUARTZ, WITH IRON. 

[Helmontite, from Helmonf, 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, puMitked by Faujaa in 4to. 
YOL. II. ft 



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VJO DOMAUf WUh ouwicvoHrc. 



NOME XV. QUARTZ, WITH BASALTIN. 

[ToERicsiLiTE, from Torrieettt^ A. D. 16^J] 

This is a scarce rock» and may rather be re- 
fierred to the mixture of siderite with qmrtz. 

NOME XVI. QUARTZ, WITH SLATE. 

[Glaub£RIT£, from Glauber, A. D. 1650,] 

A diamictonic rock, composed of quartz, im« 
pregnated with slate*. 

NOME XVn. QUARTZ, WITH FELSPAR. 

[Guj»Rien>2, from Otto von Guerick, A. D- 
1660.] 

Saussure has described a rock of this nature, 
the particles beiug so combined, that it could 
Q^ be said to beloog to either substance. 

• Sams. $ ig55. 



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llOIUft XTJIK XnL JUL. J; I 

NOMBXVnL KEEAUTE, WITH CHLORITE. 

[KuKKBi.iT£> ttotaKunkel, A. D« 1660.] 

' Tbk oombiiiatioo often fbitns the greda kera- 
lite» one of tile imi0t pleawng appearances af 
flvU rahstance. 



NOME XIX. SCHISTOSE KERAUTE AND 
SLATE. 

[Boy LITE, from Boyle^ A. D. 1660.] 

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



NOME XX. SCHISTOSE KERALTTE AND 
UME-STONE. 

[Becch£rit£, from Beccbtr, the great founder 
of modem chemistry, whose Physica Suhterranea 
appeared at Frankfort, 1669.] 

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

eS 



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5S DOUAW Tin. DlkUlCTOmiC 

NOME XXI. STEATITE, WITH ARGIL. 

[Stahlite, from Stahl, 1700.] 

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

NOME XXII. OLLTTE, WITH SILEX. 

[Pott A LITE, from Pott, 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, aad 
the lustre i^proaches that of graphite* 

• Gat St Aubyn^p. 118. 
t i. 376. 



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ivoMfts xxin. xtir. xxr. 5S 



NOME XXra. SERPENTINE, WITH SIDE- 
RITE. 

[Bi.ACOLiT£» from Black, 1760.] 

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



NOME XXIV. SERPENTINE, WITH BA- 
SALTIN. 

[Berghanite, from Bergmany 1780.] 

This substance is black, and the fracture 
spliBtery^ It might perhaps be classed among 
the Sideromagnesian Rocks. 



KOMEXXV. IIM&STONE, WITH ARGIL. 

[KiiAPROTHiT£> from Klaproth^ 1790.] 

This combination sometimes occurs in mar- 
bles; for example, in that of Campan in the 

* Bi^. nt lupn. 



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^ DOMAW TIUU JDUMICTOMiC. 

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

H7PONOMB u 

M^ronopt^ 1' Lime-stone, with argil. 



NOME XXVL UME-STONB, WITH GYP- 
SUM. 

[Lavoisite, from Lavoisier, 1790.] 

Paris. It is a small proportion pf lime, natu- 
rally-intermixed, which renders the plaister of 
Hari^3Q much superior to other manufactories 
gf (h^t substance. . 



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« 

MOMS xzm. tms-sTon, vtrm jilbx. 55 

RTPONOMB r. 

fttassive. 

BTPONOMB II. 

Schistoae. 

NOME XXVn. LIME-STONE, WITH SILEX. 

[BfBTHOLiTE, fiXMn BertkoUett 1800.] 

Concerning the calcareous stones Mr. Kirwau 
observes» that *' when mixed with siliceous par- 
ticles in considerable proportion, they effervesce 
with acids but slightly and slowly, and theif 
fracture tends to the conchoidal, but often also 
to the earthy ; of this we have a remarkable 
instance in Leske, s. 239. 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 natn j'e 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 
die particles of silex are in a smaller proportion, 
or not purely siliceous, the Ikne-stone presents 



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56 4>0MAIK niU OXAMICTOKie. 

a different appearance: thus the lime-stone, 
Leske^ s. 1769> seems as if passing into horn- 
stone^ and is of a yellowish grey colour. Lus- 
tre, 0. Transparency, 1. Fracture, fine, splin- 
tery. Fragments, 1. Hardness, 9. Sp. gr. | 
2,640* It effervesces briskly with acids, but | 
melts into a greenish grey compact enamel. I 

** Effervescence with acids is not therefore a 
sufficient proof that a stone will bum to lime : i 
thus the dark bluish-grey stone, Leske 0. 1229 ; 
whose lustre is 0; transparency, 0; fractur^ 
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. ^ 



JJOME XXVni. GYPSUM, WITH MARL. 

[Vauquelite, from Vauquelin, 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. 



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OOMAm Till. DIAIUCTOHIC. 57 

NOME XXK. GYPSUM, WITH SILEX. 

[Davite, from Dairy, 1810.] 

To this division belongs the noted marble of MwUeof 
Vulpino, analysed by Fleurieu de Bellevue*. It 
is of an uniform whitish grey, sometimes veined 
witba bluish grey. It forms no effervescence 
in the nitrous acid, though it baa the ei^terior 
aspect of a saline marble. When the powder is 
thrown on burning coals, 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, 
vases, or other works of that kind. Before the 
analysis it was regarded as a marble. 

HTFONOMB I. 

Uniform. 

HTPONOMB II. 

Veined. 

* Bnur^ u. 474. Patrln^ iii. 282. 



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DOMAIN IX.- 

ANOMALOUS. 



•bS^Stei. 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- 



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tmpaw^ being tiJaid, so to sp^akt w}(b 

japar^lazulife, efajrysolite, ami topas. 

> Those rodcs may \also be re^rded a9 
^nomaloBS Wifaich ate of very rare occuD* 
re nee, and foriDj as it were, another class 
of anomalies from tlie usual laws and order • 
of nature. Among tlie latter may lye men- 
tilted the hills of rock salt wiiich occur iu ^ 

Spain and Africa; and th^ bilk of iron, 
intermixed with quartz, to be found in 
Swediw and Laplahd. The few rocks in 
w^ch barytes is iocorpoiated may also be 
bxmexed to this Domain; mth Bitumiiious 
and Sulphuric BooIgSi vrhkh are far froni 
;coinmaii:. 

The; mtnerai kingdomi^ as alressdy mei^ 
ikmedj is liere r^Bided as divided inbo only 
three provinces^ Petralbgy, Lillioldgy, and 
Metaiogy: the. tlass of Salts and Com- cilKiSL 
bustibles being dirided bet^^eeh tl^e two 
ibrmer pmvinces. In Jbctf the terin rocdc 
«alt indicates the pravinae of tfhe only sak i 

.'which cto properly and strictly be reg^ided 
as a mineral; the others being found in. 



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xvaters, or deposited bj thein,orajppe»ii^ 
^is mere cfflonescences, or at the most in a 
gemmoAe form. And as the unportant and 
interesting study of Crystallography, or 
-Chrystallogy, originated from the observft- 
tion of the salts, they may be considered as 
* belonging to that department of Lithology* 
' ■' But the Combustibles stand in a differ* 

Cod. «ift predicament, fbr coal is, in many conn- 
tries, a very common and abundant sub- 
stance; is found in vast beds, like many 
other rocks ; and may be said to constitute 
entire faills^ as that of St. Gilles, near Li^. 
In this new point of view, therefore, coal 
has been ranked among the rocks; fand 
that division also includes the IntQmiiKms 
substances, which ouse from them, or may 
be found iti their recesses; while feunber 
and mellilite remain almost alone for the 
. nnnute investigations of the gemmologirt. 
In passing to the sulphuric substances ii 
must be observed, that a most comrnon 

Pyritoi. and general appearance of sulphur, in py^ 
xites^ is so interwoven with most df the 
xocks, that it forms an important feature 



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iQ petniiogy. Prom the Alpioe graoitet'td 
the lowest beds of coal, infinite are tbq 
rocks which contain pyrites* Henkel haa 
written a large and learned work on pyn 
rites ; and a complete investigation of them 
by the gigantic powers of mod»n che^ 
mistry, might perhaps decide the qoestioit 
so hmg agitated, whether the rocky dieU 
of this p]anet have been consolidated and 
expanded by internal heat» or merdy dei* 
posited by water. To conceive however 
that the inatter of this globe is wholly inert^ 
seems to be contrary to all the other laws 
of natur^» which abounds with various and 
prodigious kinds of motion and animation j 
and appears to be positively contradicted 
by the vast force and extent of earth*4 
quakes^ not to maation inferior {^eno^ 
mena. r 

However thi» be, pyrites £»rm an im* 
portent consideration in the knowledge of 
rocks* £v«A native stUphur may be said to 
constitute rocks at Sol&t^ira, and in Guar^ 
dalvupep aoct at St Vincent's, not to men* 



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^4| HOKJLUr UL AKOMALOIPt* 

til>B oiher volcanic tJsrritories.. It^to-ap^ 
pears disaeminated in some IkBe^^stoods, at 
kk S^siserland. and Sicily. ' The fine dry^a 
tal9 firom Conilla^ in Spain, are intermixed 
with calcareous spar, on a rock of Uuish 
ifidurated clay ; and they contribute tb tke 
elegant study of the Gemmblogist, * The 
MetaUo^st has also frequent oceasioDi to 
describe the sutphurets, or combinations 
with sulplmr^ fonncd by many idetals^ . If 
any objection should arise to thi^ahangiv 
ment^ the Saks and Combustibies may be 
thrown into a^pbndixes ; for the thetneis 
too oinfined to form a distinct province in 
the mineral kingdom, . . ' < 

From these considerations the rppk^ of 
common salt, with the bituniinous, sut^ 
phuric^ and m^allicy as thosb (^ iron, wp 
ranked among the Anomalous ; while those 
intermixed with pyrites are so trivial^ that 
k is scarcely necessary to distinguish tbeaii 
even from the common Mbde^ of the ^b^ 
stantial Domains. . :^ '^^ 

. Th&fiftt division oP Andmalims $oek% 



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WQMS 1. MIAOIVB. §$ 

a» already mentioned^ trill dtAtAy conmt 
of those that depart id theb structure from 
the common laws of nature. 



NOMEL MIA6ITE. 

This reel: is generaUy eoasidered as the inoflk 
beantifbl which has yet been discovered. In 
the mode it is a graaitel^ being a mixtare of 
white felspar and black siderite; whence it has 
by some been called Corsicaa franite, or Corsi- 
can granitel ; and by others, from some resem* 
blanoe to the eye, ocular granite, or, as it more 
prc^rly may be expressed from the Greek, 
ophthalmite. The stmctare however forms a DMcriptio& 
complete anomaly from that of granitel, as it 
codttsts of concentric but irregular circlies of 
white felspar and black siderite, disposed m 
lH!t>ad or narrow hnes, which are d^ned with 
the greatest precision*. Sometimes one oval 
spot of the siderite is sumwaded by an irregular 
oval of the felspar ; the base or ground of the 
whole being siderite and felspar irregularly voh 
termixed. In other spots the centre of siderite 
is surrounded by a light grey mixture of the two 

* There is no ladiatioti from tiie centre, ts in the plite ef 
Fatrin : that of Beuon it preferable. 



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64 DOUAlir IX. ANOMALOUS. 

Bubftaoces, bounded by a single Madeline about 
half a line io breadth^ followed by a brdader 
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 g£andules/as 
well as the largest, are those which preaient A 
narrow black line, like a hair, on one or botb 
sides of the black band. 
Site. This most singular and beautiful of all tiie 

rocks was, it is believed, first described by Bes-* 
son, a yenerable mineralogist, formerly Inspector 
General of the mines in France*, But Patrtir 
informs us that it was discorered by Barral, a 
French engineer employed in Corsica; being 
merely a large solitary block, found, by Besson 3 
account, beneath Olmetto: but as there are 
many places of that name in Corsica, the indi- 
oationis not distinct f. So imperfect was then 
the knowledge of rocks, that Besson supposes 
the siderite to be steatite. The felspar may- 
however be mingled, with quartz, as he and Pa^ 

* Journal de Physique, 1789. 

f Saussure says, § 1479, ^^at the ocular granitel of Corsica was 
discovered by Sionville; and Saussure intended to have described it, 
when he was prevented by Besson. 



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• 

trin suppose. In the base thefe are also speeka 
of pyrites, and perhaps a little yellow mica, aa 
Patrin mentioiis. 

The block found in Corsica was by the French 
noriiiefakftgists 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 discoveiy in Corsica^. This glacter 
a^ins 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 fiom the 
huts,. I gained the glacier of Mii^. This part 
of die glacier was then entirely free finom snow» 
and the ice was of an extraordinary purity ; the 
son from behind projected my shadow, which 
penetraling to a great depth in that firm and 
transparent medium, produced the most extra* 
ordinary eflfect in the world. No crevice op« 
poaed our progress ; while rivulets of clear livii^f 
water tan in transparent channels, which they 
had formed for themselves. 

^ This singular soil is covered with the most 

* StQMore's first Jmirney was published in 1786$ apd this cacur- 
sioo seems to have been perfonned in 1781. 
VOL* II. F 



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• 

beaatiful stones which I have ever beheUL Tkcr 
largest blocks, and there were some fc6m 90 W 
40 feet in diameter, were of a granikeUo, cons-* 
posed of white fekpar and black schori* in plates. 
These two kinds of stone were mingled m aU the 
proportions, and under all the fonns inumpoaUe* 
Upon one, were large parallel fiUets of tke 
purest white said black; on another^ nodulea <tf 
the most beautiful black, surrounded with con^ 
centric veins akemateljr white and black. Othen 
presented veins in zigzag, between parallel vdna^ 
Those which astonished me the naost by tkeur 
structure, were the stones which diq^hrpad pa- 
lallel layers, terminated by other layers which 
cut them at right-angles, without any iqypearance 
of rent or subsequent junction, the block iqpipear« 
ing compleiely nniformt. I greatly regrettaJ 
that these beautiful masses were not within tha 
reach of a manufSekCtory, where they might be 
sawn and cut, to make vases, and above all 
tables, which would be of the moat peiliBct 
beauty. For there is no marble which can ap«- 
proach to these stones in regard to the size of 
the veids, their extreme precision, and the bright- 

* The lan^n^ of thxt tiina for honiblfinde or sideritc r 
t So quartz sometamcs appean iQ day slate.*--?. 



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HOWS !• ICIAOITI. 



67 



nesB of the black and white which compose 
thbm. Besides, these stones are harder thao 
xnarMe^ and capable of the most lively polish* 

*^ The bases of the mountains, which enclose 
the glacier of the Miage cm the right and on the 
left, are all composed of rocks of this kind. As 
to their extcsrior lEirm, they appear almost e?ery 
whtie as assemblages of pyramidal large plates 
Teiy pointed; five, six, or even a greater nnm* 
ber <rf* these plates often leaning against each 
other, though separated by fissures whicKde* 
soend to the bottom. The pyramids are them* 
sdves 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 
whidti cut in the same direction many consecu- 
tive plates. The blodis, which are delnched 
firom the fitces of 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 
tbemsdves. 

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



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^8 DOMAIN IX* AKOMAtOUf. 

the bottom of the waters, horizontal beds, after^ 
wards raised up by a great revolution, and Iss&y 
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 in 
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. 

*^ Not being able to survey these ridges, I otr- 
served at least the wrecks with which the glii- 
cier is covered, and which come from these 
ridges, or their vicinity. Some of these frag- 
ments are of common granite, others of vein^ 

• Sauss. $ sgs, 893. In § 899, mentioniDg granular febpar rt* 
sembling granular quartz, but meltiqg under the blow-pqw, Sbuasm 
adds, that in the beautiful granitel of Miage the felspar is also ooa« 
fusedly crystallised, but its white and sparry plates are evident ^ 
whereas hcr« it is disguised in the form of a sandstone. 



Glacier of 
Laoteraar. 



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gvamte ; some of gneiss, others of granitel, or of 
a rock composed of felspar and homUendeJ 
We see the elements of this granitel sometimes 
min^^ed, sometimes separated in the forai of 
layers, some quite white, others quite bla^; 
these layers are here straight, there in zigzag, 
or interrupted by knots or kemeb; these acci* 
dents are generally the same, bat less marked, 
less beautiful, than at the foot of Mont Blanc, 
§ 893. The most remarkable rocks of this kind, 
that I saw on the glacier of Lauteraar, are those 
whi(^ enclose other fragments, whose layers cut 
at right^angles those of the stone or block which 
enclose them. I also obsenred roches de camt^ 
or schistose hornblendes, d different qualities ; 
and the fragments of that rock were coveted 
over with a yellow ochre, occasioned by the 
oxyd^tion of the iron enclosed in it. Many of 
these large blocks were sprinkled with rock 
crystfds, formed in the crevices which had occa- 
sioned the separation of the rock. These ciys* 
tals were frequently accompanied with a velvety- 
green earth, or with chlorite.'** 

In ^ 1572 he ha(} given an account of the 
pebbles of the river Isere, which rans by Greno^ 

• SauH. § 1Q95. 



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70 DO^ktn tic. AK^IIAIOUS. 

Me. Attioiig^ them Me the varMites of DniC} 
arid another varioiite, of laminar nderite, of a 
dull black inclining to green; spangled urith 
Crystals of felspar^ sometimes rhombotdal) some* 
times cifcttiar, with green dots of hornblende 
towards the cehtre, Sadssare obseires, that it 
somewhat approaches to the ocular granitel of 
Corsica, the crystallisation being only- mote 
confused. 

The following detached obsenmtions of thb 
Wilful Petradogist^ may throw additional Kght on 
this subject He supposes, ^ 159> that lay^s 
in zigzag probably arise from crystallisBtion, is 
Aey do in alabasters : and § St27» he ment i o ns 
layers in zigsag, in a granular lime^stone, mixed 
with mica, included between other veins which 
am parallel. Such layers, he adds, are not only 
found io crystallised rock, but in date^ which 
preaents no appearance of crystallisation* 

The ocular appearance is also found in other 
rocks, and Faujas has formed a seriea of tbii 
kintt Saussure indicates, § 16 1» mica dales 
often containing nodules of quarts, which, when 
cut M:ross, appear like ey^. Sometimes ihey 
are as small as grains of millet; and others are 
two inches in diameter. 

An ocular serpentine is also found in Corsica. 



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fiee Bun!, p. 31, who smy9 tbat a Merpm^xnt » 
globules, the size of a nat^ some ribboned, some 
trith coneentnc sones^ forms mountains near 
Rmorbo. 

Mr. Strange published at Milan, in 1778, a» 
account of aooie cohminar hills in the north of 
Italy. They seem to be not of granite, as he 
fuppases, but baaakon. That of plate i?. fig. €u 
mnmbles Miagtte. 

A late firench witter, who does not seem to 

hava examiued the accounts o£ former iaK)uirers 

ifUi aorideaei whksh often happens to the liw^ly 

wiiteni of that nation), infiMrms us, that << only 

ant mats of this oMtgnificent stoue was found ou 

the ihore of Taran>, half a league iixm the sei^ 

m the gulf of Valinco, m Corsica. It might 

w^gb, when first discovered, about 80 pouuds) 

bat it was toon beat to pieces, and diopenied 

tato (he principal ci^uiets, so that there now 

ooiy enit of it small pieces, either poKsfaed or 

UBpoUrfitd. A beautiful Tuse, 16 inches in 

height, IS in the celebrated cabinet of M. Da* 

dite; Md his Majesty, the Emperor aasd Kiag^ 

has a aoufrbox cf this beautiful stone. The 

beauty of this rook, and the singular disposition 

if its occurs, eufiaged every possible research to 

discover the mountain, whence the mass might 

bave rolled ; but to this day they have been uu* 



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72 DoilAni^ rt; AvdMA£ou8. 

finocessfiiU no that the smallest pieces of thit 
stone are extremely dear/'* 

This is truly surprising $ and affords a further 
proofs if necessary, that the ingenious writers of 
France, with their clear heads and universal 
talents, never think it a duty, though it bet»* 
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 been 
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 tittle town of Cor* 
ihayeur, on the river Doire; a distance aumly 
not invincible for sledges or other coaveyancea: 
and any man of common enterprise might soon 
disperse these beautiful stones all over £urope. 
The fact is, that the passage of Saussupe had 
totally escaped notice ; and at present is only 
known to M. Sage, and ^ few other niineralo* 
gists, to whom it was indicated by the author. 
' It must not be forgotten that, in what^vejr 

* Bnwd, ii. S87. 



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directioii the Miagite be cat> the nodules appear 
^e same^ so that the globular form is complete. 
It is also observable that I^aet^ a writer of the ir- 
fenteenth century, has quoted a preceding au- 
thor, Imperati, to this effect : <^ I must not pass 
in silence a very remarkable kind of marble, and 
bitberto undescribed, if I am not deceived. It 
b brought fix>m an island in the gulf of Genoa, 
called Monte Cristo ; and its colour is a greenish 
white, bat 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 
sly led Leoparderzj being spotted, not striped, • 
with black, may also belong to this stone. If 
Saussure had been aware of these instances, he 
wonJd perhaps have argued that in his grand 
debacle these stones had been rolled from the 
pre-eminent height of Moat Blanc to the islands 
of Corsica and Monte Cristo, before the forma- 
tion of the Mediterranean Sea. 

* Lact De Geaunis ei Laindibus, l647i 8vo. p. l67- Imperati 
infaniifl us that, in hk time, all the stodcs used in architecture were 
ciQed marbles i while those employed in personal decoration were 
itykd gewu. 



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74 DOMAnr IX. itKOMAlAUS. 

HYPONOMB !• 

Ocular Miagite. 

Micronotne 1. With straight lines. 

Mkronomc 2. With zigzag. 

Micronome 3. Dendritia This is the beauti- 
ful stone only found in the ruins of Rome^ the Na*^ 
ie Bianco^ falsely called a g^nanite. 

NOME H. NIOLTTE. 

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* 
Dcicription. His general description is that the base or ground 
consists of compact felspar, or felsite, of a brown 
colour, marbled with red; 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 

• Paris, 1809, 8vo. ii. $45. 



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Horn tu ino&iVB. 75 

amny ifieciwieiis from Cotrica, said he found 
them at the foot of Monte Pertusato^ one of the 
dependencies of the chain of Niolo ; which» with 
Its yalJej, ha& been long since celebrated hy 
Doiomieu for the variety and beanty of its 
lithology. 

^^ The ground of this beautiful rock is of a deep 
brovm, with nuin^otts little spots of a yellowish 
red, which have a pretty effect. They peno* 
trate the whde thickness of this stone, and pro* 
babiy arise from theoxydation of the iron, which 
abofxnds 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 tol^ 
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 poN 
fectlj 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 by the base, as if formed when the latter 
was soft. 

^ But in this sort of explication we might fall 
into the saine error as Danbentoa, when he 
wished to apply this system of formation to the 
ocular granitel of Corsica \ which, like this nock, 
is only the result of a particular mode of crystal* 



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76 OOlfAIV OL0 AIIOM41.PU8. 

lisation^ of which numeroiis examples occur in 
the rocks and ston^, 

** To distinguish perfectly the interior organi- 
sation of these balls^ and discover the manner in 
which 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 lineamenta 
more clear and distinct. It is then evidently 
seen that the interior of these balls is solids com-* 
posed of compact felspar or felsite, of a white 
tinged with rose*colour, disposed in rays, or 
rather petals*; being flat imperfect crystals, ter* 
minating in sharp points, and diverging fix>m 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 V>f 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 



• Peiahtm means a thin plate; and was originally transferred 
from metals to the leares of flowen in hotany. 



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VOUB II. NIOLITS. 77 

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

•• There is another variety of this rock, with 
little giobnles 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 iar 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- 
mantes 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 the latter kind. 
As the flowers of the former bear no small re- 
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- 
pear, the name of Niolite may 4>e preferable ; 



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>J*S I>OBCAni IX. AVOMALOU6. 

especially as Niolo is celebrated for various 
beautiful stones*. 



, NOME ni. CORSIUTE. 

This beautiful rock being also from C9rsica, 
it was thought proper to propose a geographical 
name ; and an island so eminent in the history 
of the rocks, well deserves this distinction. 
Detcriptkm. 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; 
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 large maps of Bacler Dalbe, Corsica must be im- 
perfectly i^reseatedy for Niolo, ^d other names often mendoDed, 
are noC to be Ibttod. 



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UOHE lU. COtiSUiVDM. | f 

Hone are to be seen in tbeCapeUadi & L9ceiiao« 
at Florence.** 

Sasssnre, who discoyered pebbles of this rock saoam^a 
among tbo6e of the lake of Geneva (which io* 
chide many onrions snbetanced brought bj Um 
Blione» and its conftuent streams, often firoo^ 
inaccesiable parts of the Alps), and a&erwiurda 
fonnd it in its natire places, describes it as com* 
posed o/jad and a new substance which he calls 
smaragdite^ from smaragdus^ the I^atin name of 
the ^OEierald. He found it in the mountain of 
Musinet, near Tnrin, which also presents the cu* 
riotts semiopals, called hydrophanes: and whidi 
chiefly consists of serpentine, and other magne-» 
^an rocks. In another spot abo, among mag- 
nesan rocks^ he found the same substance ; but 
the smaragi£te was of a grey colour^. Tn Cor- sttes. 
sica it is found in detached masses, which en* 
camber the bed of the ri?ulet of the village of 
Stazzona, and which came from the mountain of 
Santo Piafcro di Rostino, not £Kr from OreBOu 
Hence it has also been called Ferde antico di 
Orezza. It is also found in large detached 
maases at Voltri, near Genoa; and a similar rock 
is found at Estrador^ in Stiria. The same com^ 



* Sbqm. % 1313, ladS. See hb acooimt of imangdite, § 1313. 
Hcdbienrct, that oriental jad is rely finifak. 



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g0 •OMAXir IX. ▲VOMALOVft* 

position is found at Serviere, above Briangon ^ 
but the diallage, or smaragdite, is black, yellow^ 
bronze, grey, or silver-grey*. In oth&t in- 
stances, the difdlage has a metallic splendour; 
and the author has a specimen, whioh he re« 
ceived from Faujas, of a rock composed of kt- 
pentine and fdspar, containing metallic diallage; 
and which was discovered by the Marquis de 
• Cubieres, in the ruins of Pompeia; so that 
scarcdy^ a beautiful rock can be said to have 
escaped the researches of the ancients : and the 
rains 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 Fa- 
trin's ingenious system of mineralogy. The 
amtnifdite. smaragdite, he observes, was formerly called 
mother of 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 tha 
green is its most usual and beautiful coloun 

^ Bold, u. 309. 



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WOMB m. coRsniTS. 81; 

Silex 50 

Argil 21 

' Magnesia ... 6 

Lime 13 

Oxyd of iron . . 5 50 
Oxyd of capper . 1 10 
Oxj^ofcbrome . 7 50 

104 10 
The increase of weight arises from the oxygen^ 
which has been absorbed by the metallic oxyds 
during the operation. 

. In his recent publication^ Haiiy places the mohgt. 
green diallage as a variety of the strakUtein 
of the Germans, while he regards the metal- 
loid diaDagej or that with metallic splendour, 
as the Schiller 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 3 by Werner, a compact felspar ; by j«t 
Haiiy, from its toughness, a tenacious felspar. 
The substance called jad, has been recently di- 

* Tableau eomparatify p. 46. 
VOL. II, G 



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t2 DOMAtV IS. AV01MLOV8. 

vided into two modes^ axinitc and lemenite; the 
former, as Haiiy has quite a different axinite (a 
Pri^me. crystal from Oisans), might be called pelekine, 
from the Greek term for a battle^aste* ; for it 
implies the green substaace wrought in that 
form, from New 2!ealaiid, and fron South Ame- 
rica, where, as described by Condamitie, it forms 
the real stone of the Amazons : a tribe idly so 
called on the Maranon, or rirer of Amazons, 
because the women upon one occasion defended 
themselves, while their husbands were absent in 
the chase. This substance has been analysed 
by Hoefner, who pretends to have found 38 of 
magnesia; but his authority is absolutely null: 
and this interesting substance remaihs a problem. 
The lemanite, which bears the same aspect, has 
been analysed by the younger Saus^re, 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 Klaprotb, contain 
no mi^nesia, but merely an unctuous argil. 
The lemanite receives its name from the lake 
Leman, commonly called that c^ Geneva, 

t Silez44> Lime 4, AigUSO^ Qzar^of ison 19,6, Soda 6,^96, (. 



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MOMS IH. COIStl.l9«« %3 

• The accoont of this ioterertiiig rook shall be 
Qloted by aa extract from Pa(rin« 

^^ Tbe beaotifttl rock which the Italiaos call 
Verde di C$rsicaj ib a nuxtare of the two pre* 
ceding substances, the smaragdite and the le- 
aBiamte jad ; io which the white and the spttiny 
appearance df the gneen, hare the most beaiiti* 
fill effect. This rock is found in the primitive 
9teotitio moiiiitains of Coraica. Some magoifi* 
oent tabids of it are seen in the chapel of Medi^ 
pis ; aad lately the Museum of Arte» at Paris, 
has several; which are of the greater beaaty, as 
tfcej asnre for a base to soipe mosaic pictures 
firoQi Flore^M^e, ^hich are master- pieces of an art 
vnkoown in France. With the natural c<^lo«rs 
erf* jaisper and agate» the art of the lapidary has 
beeti able to represent objects of nature with a 
correctnesB which seems to vie with paintaog 
itself. 

^ Three of these pictures (as th^ may justly 
be styled) are on a ba^e of one single slab of 
Vtrdt 4i CfitsicQy which displays a considerable 
border all round the nciosaie i the latter represent* 
faig taUes^ or trays, loaded with diifereBt vases. . 

^ Two of the pictuites seem to be at least S 
feet long, and 18 or 20 inches high. The Verde 
di Corsica, which constitutes their base, has not 
the least defect s the jad predominates, its Colour 

o 2 



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&4 DOMAIir IX. A1I0MAL0V8. 

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 beautifiil vdvetj 
grass 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 
green, and yet of the most beautiful semi-trans- 
parency, which has a more imposing effect than 
if perfectly transparent, by the yarieties wtrich 
its mixture 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 surfiice^ 
and in proportion to their depth in the smarag* 
dite, they assume, by imperceptible degrees, the 
beautiful green colour; which, added to dteir 
undulating and festooned form, and their dispo* 
sition in little masses near each otber^ makes 
them resemble in a singular manner the beautifiil 
foliage of trees, and, in other parts^ the waves of 
the. sea gently agitated.*^ 

• P^urin, Min. i. l63. 



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XOHB IT. 9VKITB. %g 



HTPONOMB I. 

White and green. 

HTFOHOMK II. 

With violet spots on the base. 

NOME IV. RUNTTE. 

This rock is of rare occarrence, and has often 
been found to serve as a gangart to the topaz. 
It is composed of felspar in large plates, inlaid 
with crystals of grey qnartz ; which, when cut 
transversely,, offer angular figures, of which the 
greater part have the form of the Arabic nnrne* 
ral 7; while the others are more or less regnlv> 
presenting a nide appearance of Hebrew chaf- 
racters*. The resemblan^ce of Rnnic letters is Ni 
far more exact, whence the rock is here called 
Rnnite. 

The graphic granitel of Anton is one of the 
most celebrated: the felspar being of a pale 
rose-coloary while the crystals of quarts are grey, 
smdly and infinitely multiplied. Brard regards 



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86 DOMAlir HL. ANOMALOUS. 

this as the most beautiful of all. It is fottiid 
' Sites. near Autun, in the department of the Saone and 
the Loire, and particularly at Marmagne. There 
is. also found, in the environs of Autun, 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 distant from each other. 
There are also some specks of bron2e*mica» 
which da not occur in that of Marmagne ; but 
It is capable of an equal polish. 
~ That of Scotland it of little importance, as the 
crystals^ of quartz are distant^ and not sufficiently 
apparent. It is found near Portsoy. 

T^at of Siberia appears in two distant sites: 
the Uralian mountains to the north of Ekaterin* 
burg^ ami in Daouria near the river Amur ; the 
felspar being of a yellowish, or reddish white^ 
laminar, and gtiatening*. It is charged with 
crystals of smoky quartz, which may be cou« 
pared to Rmiic letters.} and is accompanied with 

• Chatcyaui, derivol from the eye of the cat ; it hat Bcarcdy a 
conespoDding term in Engljih. Rafiitgeiit? 



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»0IO Vf. ftVMVtt. S7 

MMne specks of mica, aad large needles of black 
schorl. 

The worthy aad ingeaious Patrin sajs, that 
he himself discovered that of Daoaria, in the 
moantain Odon Tchelon, which furnished him 
with many topazes, and prisms of berjrl of an ex- 
traordinary size. He observes, that the qnartz 
rather forms carcases of crystals, imperfectly 
hexagonal, the most nsnal form of thatsnb-- 
stance : and he regards that of Scotland as of a 
different crystallisation, the felspar appearing to 
have been formed in rhomboidal prisms, whSia 
&e intervals have been filled with a qnartzose 
fluid, bearing no evidence of cryshdlisation. 

HTfONOMB I. 

With distinct crystals. 

HTFONOMB O. 

With ccmfiised. 



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88 DOtfAlH IS. AWOWULBVn. 



NOME V. LAZULTTE ROCK. 

. Of this magnificent and interesting object, a 
better account cannot be given than in the 
words of Patrin* 

Dttciiptioii. <' The Lapis lazuli, often simply called lapis, 
is a rock of a beautiful sapphire blue, generally 
mingled with veins and sppts ; 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 i in some 
parts are to be perceived, in the tissue of the 
substance, brilliant plates Uke those of horn* 
blende. 

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

Ultramarine. '^ A valuable colour for painting is prepared 
frpm 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 



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.9 



VMtB ▼• &ASVUTB &«CK* gQ 

iaestimable 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 
in very small quantities; that which furnishes 
the most is Great Biicbaria^ it is fhom thence 
that it was brought to Russia, where it was so 
p"ofuse2y used to ornament the marble palace, 
t^hich Catherine the Second built at Petersburg, 
for Orlof, her favourite. There are in this pa- 
lace some apartments entirely lined with laj^is. 
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 
in£>nned me that it was found in granite 3 that 
it did not run in veins or streaks, but was 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 

'liissaidtobefinuidnearKalabaiidBudiidh, in BiiclMria.<»P, 



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90 iKmAlir IX. AHOUAlMV. 

found of an almost entire blue; but that it 
extremely rare to discover pieces as large as one^ 
head, in which the blue should generally predo* 
minate over the white and the grey. As those 
blocks, which I had seen, appeared to nte rolled, 
I asked if they had been found in the beds of 
rivers ; and was informed they were taken finm 
. the quarry, and that they were rounded by their 
Inetion 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 from 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 
is>xactly similar to that of Bucharia. 

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



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vMia T. uisuLiTS weti. 



01 



qaaHty wts sold, in his time, mt SO d<rflar9 an 
innice, wbich is dearer than gold. 

f* Dnfitj-, of the Academy of Seiences, haB 
fimkl 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 
g^y and white kinds have not this effect. 

''In some mineralogical systems, lapis. was 
classed with eeolite; but a further knowledge of 
the nature o[ 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 

Carbonate of lime S8 

Sulphate of lime • . 6 

Oxyd of iron . . 3 

Water • . . . 2 



50 



50 



100.' 



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0t DOMAIN IX. ANOMALOUS. 

Sapphires of The lozuUte appears to have b^en the sapphire 

the ancieotB. 

of Pliny) which was spotted with gold ; and an* 
cient engraved gems have been found of this 
substance. Wad mentions two Egyptian monu- 
ments <^ this stone ; being little statues, an inch 
or two in height 
wero^i The lazulite of Werner, found at Varan in 
Austria, and in Salzia or Salzburg, is a diflferent 
substance, recently arranged with the blue felsite 
of Krieglach in Stiria. But Haiiy regards it as 
distinct*. The lazulite here described, is the 
lazur stein of Werner. 

HYPONOMB r. 

With deep blue lazulite. 

HTFONOME II. 

With whitish. 

• Haay Tableau, «26. 



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HOME Vl. eSAVITB WITH SAPPAKB. 



NOME VI. GRANITE WITH SAPPARE. 

This rock has only been racentiy observed* 
The sappare is in small spangles^ of a livdjK 
blue, being interspersed among the comoKm in-* 
gredients of granite. 

Saassure informs os^ that he first received this 
substance from the Duke of Gordon, among 
other Scotish minerals; who informed him, at 
the same time, that the Scotish name was sapt 
pare*. Werner (whose fondness for the woo£ 
of all nomenclatares, that derived from acci* 
dental colours, has been ably ridiculed by Mr. 
Chenevix)> has, forgetting bI\ dne respect to the 
great name of Saussnre, most needlessly changed 
this denomination for Kyanite, or blue stone \ 



NOMEVn. 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 south of Labrador, has scarcely 

• § 1901. 



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M IK»XAHI IX. AMOMALOOS. 

yet been observed in the parent rock^ which is 
only inferred to be a kind of granite. Another 
rock containing opaline felspar^ but of &r infe- 
rior beauty, has been recently observed in Nor- 
way. The felspar is conjoined with a very hard 
reddish substance, which has been mfferred by b^ 
quarts. 
^^'^njwear- j^ the Bee, a periodical pap», t>ikblishe4 at 
Edinburgh in 1798, by Dr, Anderson, there is a 
Cttvious account of precious stones l^ Dr< OttOh 
tie, physician to the corps of Noble Cadets at 
Petersburg, presenting some intere^tmg parties- 
Iters ooucerniug those fottnd in Siberia. A ew* 
respondent df Dr. Andeirson*s has added a letter 
concerning the first appearance of the Labrador 
stone; which^ being little known, shaH besots 
Joined. 

" The coast of Labrador is a cold inhospitaUe 
country, bordering upon Hudson's Bay; and 
was granted by George II. to a religious sect of 
people,, called the Moraviaftis, who sdlicHed and 
obtained it, in order to convert to their way of 
thinking the fbw 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 



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NOUS Til* lAMtLADOai ftOGK. 



whieb, if it had b^eo prol^erly iiMutaged» woald 
have pto?ed little worse than a silver mine; 
Some of the EbgUth settlers, walking along the 
borders q( the inland riversb observed particnbr 
stones of a sbiuiBg ot^diae colour ; these when 
slit, ov out in a mill and |^ished» diiqplayed all 
the variegated tints of coJonring that are to be 
aeea Uk the plumage of the peacock, pigeon, or 
BQoat delicate hainmiQg4>irdsL Some of these 
beaotifiil stones being sent as a present to their 
fficMb in Ei^land, soon attracted the notiee of 
the fevers of the fine prodttctiona of nature, who 
bought them up with avidity. From England 
the same desire spread all over Eurc^e^ aod 
every ooUector was unhappy till he coidd enrich 
bis coUection with speoiiaens of difibreat co^ 
loutSi wbich are no less than se^en, often mixed 
with varying tints attd shades. Some oi the 
hurger specimens have four distinct colours upon 
the same slab; but more generally each stone^ 
as-found in the lumpi has its own palrticular co^ 
lour, and whteh most commonly runs through 
the whdle. The light bhie and gold b the nmol 
common ; green mixed with yellow, is the next^ 
ike with a purple tinge^ not ao common; the 
fine dark blue and silver^ still Jess; and fine 
scarlet and purple> least of all. The largest spe^ 



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g6 DOMAIV IX. ANOMALOUS. 

cimenfi yet discovered are about three feet 
circumference; and all over one continued glc 
of colour. I have seen many blocks of it greatfy 
larger than the above, but they had only spots 
of colour here and there, thinly scattered. The 
first quantity that was exposed in Edinbmgb, 
was in the year 1790, in a ware*room on the 
south bridge, by one Shaw, from London, a 
native of Aberdeenshire, who, 1 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 usimI 
goodnests, 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 isome most brilliant 
specimens of Labrador spar ; particulariy one ai 
fine, extremely bright, and variegated colours ; 
one pretty large, of the scarce fire^colout 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 ston^ 
when analysed, is found to contain a portion id 
calcareous matter, and some particles of silver 



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VOirx Tli;' LABBA09X XOOK. 97 

nkktiii*^. 9ome pieces ,bear an exceeding high 
polish, but very 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 
hare 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 the money. 

'^ John Jeans, the Scotish fossilist, lately dis- 
covered a spar very similar and much resembling 
the Labrador, in the shire of Aberdeen; but it 
only 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 stnnge analyst! 
VOL. II. H 



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of ftbriUiia&t gdden Irae, with 8om» ^ery aoMiil 
aspotB Uke mica/'* 

HTfMfOMK I* 

Noble Labrador, or opaline felapar. 
Micrmtme 1. Norwegiw blue. 

KOMEVia. KOLLANXTE. 

DescriptioiL This rock, which, if not the first, ranks among 
the first in beauty, consists of round or oval peb- 
bles, or rather crystals, of various colours^ in a 
siliceous cement, sometimes approaching to trans-* 
parent quartz, at others itself a bricia of minute 
fragments or crystals. The most CQmmon co* 
lour of the pebbles is grey, followed by the 
brown, black, dark blue; the more beautiful, 
yellow and red; the rarest being the green. 
The cement is also of various colours, l>ora the 
transparent quartz to the opake red ; sometimes 
of a metallic yellow, perhaps from disseminated 
pyrites j 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 axe verf two ftnd valnablc. 



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arMQd particalar pebMea^ or in dtitioct ptrts, 
ansiBg finam the inflaence of the oxyd of iron* 

Thb is the cddmted pndding-stoiie of Eogw F^ddng^tHK. 
landj 80 much in request in fomgn coirotries; 
but this name commonly exciting a smUe among 
the illitenite, and the appeUation being since 
enlarged to a great onmber of ^ntenites, of a 
different natnre and origin^ fbiming entire chaiu 
of moiuitains (while this is confined to a veij 
small district in England^ and is found no where 
else in the world), it has been thought proper to 
distinguish it by the name of Kollanite ; derived 
from the Greek% denoting its appearance of 
being ce m e n ted together. 

The pebbles also, which are inlaid in this NoUtSaL 
beautifal substance^ sekkm belong to common 
flint; but to an intermediate kind, between flint 
and chalcedony, which, in the impcffeetion of 
the Mcience^ , has not yet been characterisad. 
KaiBten, in his catalogue of Leske's coHecnontt 
has mentioned^ among the minerals of Pdand^ 



* K^XAa c0fii«ii/.- it ts aho used tiy Diosooriilei, tnd dChn, fbr 
iron, which in the minenl kingdom fDrms an ahnott onivcnal 
^uien. See Collini tur Um Jigaiet, p. 156. 

In words firann ofee Gteek^ the ori^nd'asMf Eo^^lflh K if pefieiRd 
tDtbeLatifli md French C. 

t iL47l. 



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100 ooMAur tX4 AiroiUfiov«« 

Bme specimens of flinty chiefly yeUow orsfxitte^ 
which must greatly resemble to those m At 
KoUanite^ and wbicb^ as he obsenres; approach 
exceedingly near to chalcedony. Many may 
ako be said to be agatised; being disposed, like 
Bgtkief in concentric lines of different tints aad 
colours. It is indispensable that a new term be 
applied to this intermediate substance; and die 
dudite. Greek name of Chalite is proposed, from the 
word for flinty but which has not yet appeared in 
mineralogy^. 

To arrange these pebbles with common ffints, 
would only occasion a confusion of ideas. They 
belong to an intermediate substance, betweem 
fOmt and agate, which indeed Haiiy has ar« 
ranged together, under the name of QmriM 
agate. That flint which is found near Paris^ 
with the layers and beauty of an onyx, and that 
called menilite, might also be classed as different 
structures of this nobler kind of flint ; which, as 
ailex is from the Latin, might be sought, as before 
stated, in a higher source, the Greek, and de- 
nominated chalite. Like chalcedQny or agate. 



* XaXi^4 The Hebrew, it is said, is chalamish. Rei^cn 
Vened in that language, may cnosult Deut. Yili. Id.^ Pi. cxiTw •• 
If. Y. 28. JU. 7' £sek. ui. 9. 



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vnu. KMXAVjnr.' 101 

to«liif h ik^Mattketimn paases, aceovdmg to Mr. 
Kinrw> it is ioften aecidentalijr impregnated 
Yfith jasper. 

Tbese pebbles are often found detached, and ^^jj^ 
ofa particular beauty ; which, wanting however 
Ae* delicacy of some agates, resembles that of a 
rustic .girl when compared with the elegance of 
ki^ life. Some present circles and shades of 
Tarious : tints of brown, approaching to the 
Elgyptian pebbles; others, various concentric 
lines 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 
Us regular black bands upon a white ground. 
If we believe Dr. Woodward*, who made a yery 
larg>e collection. of English pebbles, fine agates 
huve been found near Gaddesden, in Hertford* 
shire> one of the boundaries of the pudding* 
stone ; where have also recently been discovered 
some fine flints with purple illinitions, like land« 
scapes, perhaps tinctured with manganesef. 
That industrious author informs us that the KoU 
lanite is common about Berkhamstead, in Hert^ 

• Nat. Hbt. ofED^iih fbMilt. 

f CoUini observes, p- 146, that agates are easily detached from 
the Tock, beeaose each is enveloped in iion ochre. This remark * 
applies 10 many kolhaitcs» 



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}03 DOMAIN 1«. AVOHA&^Vt. 

ford8hir;e> where it 10 called the hrtedmg^stmnt. 
^'^^ This is also the case at St Albans (which, witb 
its vicinity as far as Market Street on the north, 
may be regarded as the chosen district of the 
most beautiful Kollanite); the name arising' 
from the common idea that this stone breedij or 
produces successive pebbles. The breeding* 
stone rnust^ however, be distinguished from the 
mother-^tonCf of the same county ; which is an 
iron-stone, with pebbles of quarts, depoeited in 
layers above thecbalk; and sometimes approacht- 
ing the surface, renders whole fields barren* Dr« 
Woodward also says, that at Aldenham, near 
Watford, Hertfordshire, this substance, there 
called pudding-stone^ is very fnequent ; and some 
masses weigh near a ton ; nay, he mentions a 
mass of three tons, at Corner Hall, near Berk- 
hamstead ; and that labourers i^ut St Albans 
speak of masses of a similar size*. 
Sites. From personal inquiries and observations, it 

appears that the fairest pudding-stone is duefly 
found at the ancient and venerable town of St. 
Albans, where masses often ocour in the pave^ 
ment ; and its northern environs, as far as Mar« 
ket Street, where it also forms a great part of the 



• Sita «f little conseqaeace, or erroneouB, afipear tp be Tvm 
Waters, West Wycombe, the oonnty of Berk*, ke. 



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nil. KMJL4IIJ7S* 101 



l^avemejtt. The maionf of that titot, ftot o^ 
aenriBg its beauty and fiog«laritj> have often 
mixed k with commoo flintt as it ocdurs in the 
Beighbonring quarries, in the walls of the Ahkej 
Church and its pteclnctSi a&d ia those of the 
nunnery of ^pweU. The author even fimnd at 
the apot cidied Gorhamboiy filodk; a piec^ 
wlMch had £dIeD iiiom the fiomaa walls of 
VeroJaiii^ being flat» like a Roman brick, with 
Mine mortar adherent. Bat as a beaatifhl and 
vatnable, stone, it seems to hare been aidaiown 
till the aeventeemfli ooiturj. 

It is also said to hare been obserfed in the bed 
of theBiverLcSa^atLflton. . The ingenious Mr. 
Paddoson, whoie wotk on {>etrifaetionB is wcU 
knownsobtanres in aletter to the author, ^'tha* 
towatds Waie, in the sondi^^ast, and from 
Amet^dmrn to Kings liui^ey, on the so«A«-west» 
I have sought for it in vain; but between Hemel 
Hempstead andTring, I have seen large massesg 
whkdi IsnpposehaYebesndngapinthatneigh^ 
bonibood. The flint containing Alcyonia, 4o« 
eanes about Amersham s and soon after, I fa»* 
liere, rather mora to the norths commences ihe 
pudding^stoaa" In short, if we take a line from 
St Albans in the south, to Market Street in thtt 
north I and from Tring in the west, to Hatfield 
in the east; we riiall have an cfclong-square, of 



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104 BOHAIH IS. ANOMALOVf. 

about 90 miles R and W. and about 10 N. and 
S. which may be indicated as the peculiar dis* 
trict of the KoUanite, or precious pudding- 
stone/ 
sheOs. Shells, or strong and marked impressions, have 

been found in the very centre Of masses of Kol- 
lanite, which with its superihcumbence on 
chalk (where however it only fbrmS dietach^ 
masses^ like those of siliceous saod-ston^, or gra- 
nular quartz), have been regarded as proofs of 
its recent formation. 

On Barnard Heath, near St. Albans, along, 
with the inasses of pudding-stonie, 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 positioii 
would argue little, while the shells alone would 
evince it a secondary ' substance. They are 
conimotily sinall chamites ; and, it is believed, 
have never been discovered in this finest kinds.* 
Mr. Parkinson* has observed, that the numercms 
pebbles found in gravel-pits, &c. have seldoia 
been rolled -, but, on the contrary, their present 
forms are precisely those.which they at first de« 

* Otpoilt Renudnt, i. SS3* 



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VOIU TUI. &0UiUIIT8« 101 

Tived from the siliceous impregnation of serenl 
animals^ which existed in the prixnieval waters. 
He supposes that the pebbles were at first soft 
nodules of martial clay, or marl, often composed 
of laminae of different ccdours ; such, as he says, 
have been frequently found in the gravd-pits of 
Kagland, and in Jai^ heaps in various parts of 
Italy. Tbey are afterwards impregnated with ^^[2«ltf* 
siliceous juice, which may be of very recent 
origin; forsilex is soluble in water, as appears 
from the analysis of many medical waters of 
England, not to mention the fouptain of Gey- 
2er 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 rush, in 
particular, seeming to consist entirely of siler. 
In stacks of burnt hay, there are found porous 
stones, resembling frits of glass. From these 
examples it can scarcely be denied that silez 
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 



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10$ BOICAXM f«» ASOaiAMINft 

the prectae epoch of tiwir oreatioA; and thus n 
few shells might appear even in sabatancei Myledl 
primary* 
^i^nof That patient and oarrfal obierver, Saosswe^, 
hasestabikhed as an axioui, thai pebhies ori*- 
gmaRy so formed^ and not prodnoed by attritimi, 
may be distinguished by their concentric layers* 
or by a nodule* whose form corresponds with 
that of the stone : thus what he caUa petnsilex i 
eoarcey or with a rind, is a flint found in natural 
nodules, the rind being from six lines to an inch 
in thickness, of a grey dmost opake ; whilst the 
concentric kernel is of a fitwu-colour, and asmi* 
transparentf. 

With regard to roUed pebbles, the study of 
which he has particularly recommended* as per» 
haps more essentie^ to the theory of the earth 
than that of the rocks themselves, Saussure has 
remarked, and the observation has since been 
repeatedly confirmed, that the pebbles of the 
>ides among mountains are derived from the 
rocks of which these mountains consists but the 
pebbles of the large open plains seem as if 
dropped from the sky, no parent rocks appearing 
in ^ space of hundreds, and even of thousands 
of milesr];. It would seem, from many circum* 

• 5S0I. t §isW. H717. 



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ilaaoes^ Unt whife the primeval waters covered 
tbia^loke^Bo panicukr oceans nor seas odstedL 
H^ence tke currents of the chaotic ocean^ of &r 
aaore force and activity than we can at present 
conceive, have rolled these pebUes from im« 
BMoae disUnces, as pfoducts of Florida are by 
the gulf stream brought to Newfoundland, and 
even to Shetland and the Orkneys. De Lac has 
Ofaservedy that the stones scatt^ed over the con* 
tinentsform a principd gedogical monument) 
and any theory which passes this phenomenon 
in silence^ can deserve but little attention from 
the real natamlis^. So true it is that tbe plains 
are more difficult to illustrate than the moun- 
tains; and he who can explain the formation of 
a pebbky may explain the formadou of the 
globe. 

Doctor Kidd*8 obsecrations on the pebbles of 
England^ deserve particular notice on this occar 
smut* 

** The larger masses are in many parts of 
England called bowlder stones^ a name expressive 
of the cause of their rounded form : the term 
pebble, is in common language applied to those 
which are smaller than the foregoing, but too 
hf go to be used as gravel ; and these are very 

• Gcotogie^ 951. t VoL & appmcL S9. 



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t08 MtUklK IX. AtfOMALOUf. 

commonij employed for the purpMe of paviagf 
court-yards of Jiouses, and the streets of smatt 
towns. CoiomOD gravel is too familiar >to need 
any description. Pebbles of the smallest dimeK 
sioDs constitute coarse sand. 

" The gravel. immediatdy rouiid London ap-: 
pears to consist almost ^itirely of the black flint 
met with in the neighbouring cbalk strata : the 
pebbles are in general very uniformly worn, and 
have to a greater or less extent iost the charac- 
teristic black colour of the ftint, from which 
they are derived; hot sufficiently correspond 
with it to shew the identity of their natare. 

'^ The gravel round about Windsor imd Maid* 
enhead consists also> in a great measure, of tha* 
flint of the surrounding chalk-hills ; very msch 
discoloured, but not much worn. It appears9 
however, that that part of this gravel which is 
nearest the surface is not of the nature of ^t^ 
but in its texture resembles a highly indurated 
sand-stone : and it is observed that these pebbles 
are much larger than the flint pebbles; and, 
though cpnsiderably harder, are much more 
uniformly rounded. They have probably, thei» 
fore, been conveyed from a greater distanbfei 
and judging from their relative situation, fw 
they are found nearest the surface, they haive 
been deposited more recently than the flint It 



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m woiibi obsenring^ that pdbbles of this kind am 
met wilii in almost every part . of En^and. I 
liare coUected.theni from very diflEesent points 
alcmg the C(»ir8e of the North Road, both on tile 
eastern and western side of the island : from 
Nottingham, York, Durhani, Edinbnrgh, Lao- 
arkt Carlisle, Chester, Shrevrsbury, and Wor- 
cester i and have observed tbem in many other 
parte. 

'f The gravel met with immediately round 
Qz£>rd consists . principally of small siliceoos 
pebbles;. many of which are flinty mixed with 
worn fragments of fossil caicareoos shells, and 
bi^wh iron-stone; the pcesehce of all these 
substances, is accounted for by the nature of the 
Bnrconnding. country; the limestone of that dis* 
trict abounding with fossil shells, and many of 
the neighbouring hills consisting either of chalk 
containing flint, or of ferruginous sand cont&in^ 
ing brown coarse iron-stone." 

But it is time to return from the consideratwn 
of the pebbles, to that of the rock under view> 
which has also been called a pebble-stone by 
som^. authors. 

That there may be no suspicion of national 
prej.udtce, in the account of this singular rock 
(which jiot only surpasses most others in beauty 



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110 B9MAiir nu AweiiALmM. 

and vftriekft but aflbrds many tmportaat lemooB 
in gedogy), iv« shall traniUte the detcriptioii of 
Pktrin i who had not only inspected the ? idlest 
cabinets of Enrope, bat had resided for eight 
yeaTB in Hofisia and Siberia, which afford some 
of the most beautiful mineral sobstancea. 
MM <« The most celebrated pudding-stone, and 
whidi on account of its beauty obtains a {dace 
in all cabinets of mineralogy, is found in some 
riTers of Scotland, in small rolled masses, which 
are seldom more than five or six inches in diame- 
ter* It is generally known by the name of the 
pudding-stone, or pebble of England. 

*' It js formed by an assemUage of small siK* 
eeous stones, the interstices of which are filled 
by gravel and very fine quartsy sand. The whole 
is united by a siliceous ghiten, of an opake white 
colour, which is not easily perceptible without 
the* aid of a lens. 

** The pebbles which eompose this beautiful 
pudding-stone, are at meet of the size ctf a wal- 
jrat, and oflener of that of a bean or an alaMud. 
They are coloured with various tints, bwt with a 
remarkable singularity ; for these colours are dis- 
posed in concentric layers. It seenss then that 
these pebbles are little itnts^ which have beea 
formed such aa thqr are, but in another matrij 



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mn» moLhA^nmrn 111 

from whasce they have been detached hj the 
waters, and afterwards aggluttnaled bj a qaartaj 
fluid. 

** The coaeefitric layers which are observed in 
ilieir interior, seem to demonstrate that it is not 
to friction and rotting that they are indebted for 
tbeir round appearance^ It even appears that 
thdr primittre fofra has been no ways altered; 
for the interior layers are not only parallel 
among themselves^ but even always parallel to 
tiw surfiM^e of Aie stone, whatever may be its 
ahape. It is not uncommon to observe some 
which are triangular, of which the interior layws 
present sevevid triangles, one within the other, 
and always parallel to the surfiace of the stone. 
The most common cotonr of these layers, i$ 
yellow, red) white, and blntsh ; this latter tint 
is generally that of the surface of these Ntlle 
pebbles. 

^* There is a circumstance whidi seems to 
prove that these stones have not been tossed 
siMut by the waters for any long time; it is^ 
that they are stoost always observed mingled 
with fragments of flint, aU the angles of which 
Mesharp« 

*< With this pudding-stone are made boxrs^ 
trivhets, aUNl boautilul little Mba, which by the 



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llll DOVillM It. AMOMAftlMM. 

variety of tbekr colours^ and the vivacity ef th^r 
polish, are infinitely agreeable to the ejre,"* 

Brard s account is as followsf : " The pud^ 
ding-stone of EngUnd is composed of tittle peb* 
Ues round, oval, or elliptic, of the si^e ol an 
olive, brown, grey, or yellow, imbedded iu a 
cement of a grey, or of a chamois colour. 

<^ This pudding*8tone, which is highly estei^oi* 
ed in jewellery, is found in rolled. fragments in 
certain rivers in Scotland. 

*' Although the pebbles, and still less tl^ ce« 
nient of this pudding, be not of a very fine 
paste, it nevertheless takes almost beautiful po* 
lish. It is wrought in many works of decora- 
tion;, but is not fit for small jewellery, such as 
earrings, necklaces, &c. It is used with more 
advantage in making boxes,, socles, handles of 
kniyesj etuis, &C.'' 

He then proceeds to describe the pudding of 
Chantilly, which consists of fitr larger pebbles, 
of a deep yellow, bordered with a bluish blacky 
in a cement of quartzose sandstone. A finer 
kind is. found near Chartres, in the department 
of the Eure and Loire, composed of -very small 

• iii. 350. 

t TniUdctpi«/ktipneieiiiai»i.lSS* Pnul80St9T*b.8vo. 



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jiMiB Tin* KOLUkvnrv. lU 

broiKrn and black pebbles, united in a stlex of a 
yellowish white. The pudding of Rennes, which 
he subjoins, has been shown by Paitrin to be 
merely a spotted jasper. That of Chartres musk 
be also the same described by the acute Patrin^ 
as merely an oculated silex> a keralite, or hom- 
stein of the Germans. 

The pudding-stone of England, therefore, re* 
tains that singularity of composition, whibh hat 
diffused its name through all languages, and 
been admitted in all works of mineralogy, in an 
assumed contradistinction to bricia, which c6n« 
Msts of angular fragments. 

But the learned and sagacious Patrin is hiiti* 
self mistaken, when he says that the pudding* 
Btone is found in the rivers of Scotland. It is 
true that a rough pudding-stone, composed of 
rolled pebbles of granite, porphyry, clay*slate> 
quarts, trap, primitive liinestone, and other ori^ 
ginal substances, in a cement generally fermgn 
nous or argillaceous, accompanies, on both sides^ 
the Grampian chain of mountains, as it do^i 
that of the Alps. It sometimes, aa Faujas has 
observed, even contains green porphyry^ and 
green trap, and thus approaches to the famous 
universal bricia of Egypt But these Scotish 
rocks have only a slight resemblance to the pud- 

VOL. II. I 



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114 DOMAIN UU AttCW^UMil. 

4iag-s(oiie of England, as shall presently b^ 
shown. 

' B^irfi is also mistaken when he asserts that 
the paste is not fine i for, in the choicest ^peci* 
Ittensj it is of surprising fineness and delicacy. 
KoDanito It.would appear that this beautiful ^ooe is 
EngiaiML^ quite uukuown in other regions. WaUerius hv 
described it as a rodk^ composed of various flints, 
Mdd England is the only country he mentt(»0*; 
for those of Rehnes^ in Normandy, are, as Patrin 
has shown, only spotted jaspers. Gmelin, in 
^ the last edition of UnnseuSi has described p«d* 
ding-stone as consisting of firagmehts of petro» 
Mlex (homsfcgin) and quartz, cemented byjas- 
per4 He says that it is found in England^ and 
also upon the Rhine and in Bohetnia, assimmig 
Hn e]Kquisite p<dish, being variegated,, but the 
jaspev g^nerfdly of a brownish red -, bfad is osed 
fi>r,vases) and various Unds of oraaments^ His 
^teseriptiote nay apply to that of (he Rhine,, as 
(MMita^iiag ker&ds of reddish brown jasper, and 
iksA of Bohemia) but is quite foreign to tht 
&ig)ish pad<yng-stom« 

Mr% Kir waa^ disgusted with the vulgar name 
of puddi«i|;^stone^ derived froib the resenaUaQCt 

•k444. 



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of a CKniitiidft kind to ft ]riQflib-pilddmg^ cmh 

posed of ddUr Wilh raiftiDs and coriiitlifl*, Md 

t?hich befng strictly d«scripflive, has pacuM wUk 

all languages, i^ iiicUited to prefer the Ladfc 

farciKte of similar import*, but the Greek KoU 

lanite is preferable, the Latin having passed itto 

the ^i^matic /dff cif, whJdh ekes out the entei^ 

taimnent like the oM ^tnAnfarcmens, er pad«* 

din^. He <}iio(e9 the miners' joamal, pnUishod 

in Gentian, for a monniain of fareilite w pod*- 

dm^stone, in Siberia, near a rir ulet caUed Tulat, 

consisting of rounded fragments of jasper, cbat> 

cedonj, camelian, and beryl, in a qnarttsy ce** 

mentf. This be considers as primitive; but 

among the secondary rocks, <{uotes tbe MOte 

passage, only omittinfg the beryl, tvhieh indeed 

seems foreigti to such tf substance* Etenthts 

can scarcely rival the English puddirtg^stone in 

beaoty and variety ; and, if it consists of round^ 

ed or rolled fragments, must be of quite a diftr** 

ent nature, as shall presently be ecplahied. 

The errors of foreign writers, concerning this 
lingular and beautiful pfoduotion of Englind^ 

V 

* A small grail* onginally from Corinth* Imt mm chiefly inh 
ported from Cephalonia and Zanle, and which has been used for 
ceotunes in the English kitchen. The French have no puddings^ 
the boudin being a hog*s-pudding. 

+ GeoL£ss. 21«, 

I2 



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lie BOMAIM IX. xnOUAMAWB. 

vrill appear the less surprising when we consider 
the following descriptions just published by the 
learned Dr. Kidd, professor of phemistry in the 
University of Oxford^ in his account of what he 
calls pebble-stone*. 
^Mt . f« This term is applicable to a numerous class 
of rocks, &c. consisting of pebbles of various 
«2es and colours; which are irregularly con- 
nected together, either with or without fin inter- 
ibediate substance ; and it is presumed that the 
cemeaited particles are pdi>bles, or have acquire4 
their rounded form by atthtiouj from their uni- 
form smoothness. . > 
t* One of the most striking varieties of pebble^ 
stone yery commonly occurs scattered in larg? 
masses over the vale oif Berkshire ; it consists of 
nttid^KMis Qval pebbles, of reddish black flint, 
very much resembling raisins when swelled by . 
l>oiling, cemented together by means of indu- 
rated sand, of a brownish white colour. The 
whole appearance of the mass has give^ ri^e to 
the term plumb-pudding-stone, in this country i 
^nd the resemblance that gave rise to the term 
is so remarkable, that it cannot fail to strike the 
mind upon tlie first view. The term has been 
very generally adopted by foreign mineralogists ^ 

* Outlines of Minenlogy, I8O9. App. p. 81. 



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HOME Yin.' XdLLARm* 117 

wko, however, cominonlj call it simply fmddtng'^ 
«tone» or English pudding-stone fpauding^ of 
Brocfaant; poudding Anglais^ of- Haiiy). Fo-^ 
Feigners 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 npon the application of a sufficient 
degree of force, the fracture of the stone is car* 
Tied on indifferently through the pebbles as well 
9S the cement; in some instances the fracture 
takes place in such a manner as to leave some 
<^ 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 aogular fragments of pebbles. Both varieties, 
when the cement is sufficiently hard and com^ 
pac^ are capable of a very beautiful polish. 

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



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CfiiiB ib foiled fragtneats in the bed of the lEslce; 
near Rosdyn Castle: k consists of nomeron^ 
diflerently coloured particles, some resembling 
led jasper, very compactly aggregated withpul 
any intermediate substaace." 

This last may either be a spotted jasper, or a 
jasper brioia. 
Accomrames The coa^se pudditig-stone accompanies at iQ^ 
tervals the vast chalk stratum of England, whose 
tiodulating oqtline, from S. W. to N. £. may he 
e^mputed to about 600 miles. This coarse pudf* 
ding-stone consists of common flint pebbles, 
lomettmes united by an argillaceous cement 
sometimes by a ferruginous, at others by au 
arenadeous rendered coherent by oxyd of iron* 
The red gri^vel which affords such an el^ant 
contrast with verdure, and is well known for its 
binding or coherent quality, approaches nearly 
to the latter kind; and masses of such pudding- 
9tone are frequent in graveUpits, even in the 
n^ghbourhood of London* A large mass may 
be seen in the lane, which ascends from Kentish 
Town to Kenwood, to use the orthography of 
Lord Mans6eld, derived from its ken, or wide 
prospect. 

But the precious kind, whrch has acquired 
such celebrity all over Europe^ for its beauty, 



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variety, and pleasing accidents^ sot obpeimUil 
in any other rock, seems confined to the dtrtfMQt 
of Hertfofdshire above mentioned. 

If the term pudding-stone be restricted to 
what the Germans would call an aggiomeratei 
substance, it may ev^ be doubted whether it be 
properly applied in the present instance; for it 
is not only dear, as Patrin has remarkad, that 
the peUiles never have been rolled ; bnt, from an 
accurate and minute examination, that the whole 
is an instantaneous composition, a kind of di** 
turbed crystallisation, like granular quarts ; or» 
as in the stones called glandulites by Saossnrfib 
as containing nodules of a finer or coarser graia# 
It would seem that an intrusion of iron and day, 
or what is called jasper, has imparted tbis peci»« 
Kar appearance, as iron often inclines to the 
pisiform and fabiform. Or it may be that in a 
siliceous sediment the iron asserted its predMii« 
nance and affinities, to assume these singular aad 
beautiful forms*. But geologies might compoee 
whole treatises on this rock alope ; whidli may 
he as important towards a theory of the earth, 
as Saussure found the noted pudding-stone of the 

* On the influence of iron'in such formations, see Collini*s inge* 
nloos little work on the Agates of Oberstein. Manheim, 1776, 
12mo. p. IS6, seq. 



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ISMi DOIfAtll IX- AirOIIAL«UI. 

Alps, whose vertical position led to his theory iof 
refimlements. 

A shell of the cockle kind, as already men- 
tioned, 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. 

The varieties of this curious rock are almost in- 
finite; and it is diversified with almost every sbade^ 
of colour, except perhaps 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 
beautiful 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 informed, from undoubted authority, that the green 



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K01CB Tin. xatLAvm.- lif 

toKyceaknc zones of Bgatey while o^ers are 
spotted ID infinite variety ; and others^ though 
rarely^ are nnicoloured. The beautiful marble 
bricia of Aix seems of a sioiilar instantaneous 
formation, and approaches the nearest in point 
of variety, but is far inferior in tints and polish. 
Nor can a comparison be instituted with others 
the most beautiful amongst the rocks; such as 
blue and green granite, serpentine, miagite, 
niolite, 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 grey pebbles in a grey ce* " 
meat, 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. 

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



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I2S D01CAIV m. ▲iraiiAt.otft. 

ralfaer, as would seem» of miiiate sand, penetrated 
with siliceous liquor or pure quarts. 

S. Little dark grey nodules, in a lighter ce* 
ment, of a yellowish white. 

4. A fawn-eolour cement, in some places in- 
dining to white, in others tinged with red, and 
studded with chalite of bluish grey, pale brown, 
lead colour, all inclosed in black i^nes, 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 inches 
square, containing great varieties of brown and 
yellow chalite, often with zones' or tinges of 
lilac, purple, and a faint olive green. Many 
are spotted, with various tints, while others have 
numerous zones, like agate. The whole in a 
cement of coarse sand, of the same nature, agglu- 
tinated by transparent quartz, so that the sub* 
stances 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. 



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yoMB nil. K9i.LiaiiTs« |2f 

& A detached large pebble, with a small ad^ 
herent portion of the real kollanite, or precioua 
pudding-stone. This beautiful pebble, ivUch 
rivals or exceeds the'iinest jasp-agate, is encir*^ 
clad with a brown zone, followed by one of 
erittison, the middle of a fine variegated brown, 
simietiines inclining to yellow, bearing near the 
oeotre 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 
00 Hampstead Heath, and many other places. 
Thi^y are quite different from rolled pebbles, and 
are often of a flattened, sometimes a kidney 
form, like those in the koUanite. Their exterior 
appearance is of a brownish blaek, with little 
lineal indentations, as if encrusted. They are 
called by the lapidaries English pebbles, to dis* 
tiogaish them from what they o^H Scotish peb« 
bles, which ^re generally of an impure agate. 

7. Pebbles of various tints, but chiefly yellow 
and brown, in a whitish cement. The singu- 
larity c^ this specimen, which is about 6 inches 
by 3, is, that a little stream, as it were, of a light 
brown cement, and about an inch in breadlh, 
runs down the middle, bending by the side of a 
very large pebble. In this stream the pebbles 
are all parallel with its direction, as if conveyed 



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124 BOWAXN IX. ANOXAtOOC 

by it, while those on either side are in 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 in 
every conceivable form, in a granular transpa^ 
rent cement, which however inclining to pale 
red, affords not the strong contrast which a fawn* 
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 camelian, with the usual Mack 
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 large 
red nodule is split in various directions, yet the 
fragments perfectly preserve their position, the 
chief 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 cbamite, about a quarter of an inch in dia^t 
meter. 



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mouM Yiiu Koujkinxfi* 19$ 

* In this piece may also be observed a verjr 
large pebble, split ia two, but not displaced, the 
crack beiog filled by the cement, which is of a 
-doll 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 coiitatning small quartz 
crystals* A pebble, in the state of indurated 
day^ 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^an a straw-coloured cement. 

IS. Cement, half red, half yellow, with dark 
pdbbles. 

IS. 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 ruinoun 
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 



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1C6 DOMAIN IX. AHOllALmn. 

suudl lines ^ purple ; and one may be stjried 
agate, or chalcedony, being white delicately 
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 d6ve-colour. 

18. Brown, yellow, and red pebbles, m a g& 
ment of an ash grey, which only adfirits a dd 
earthy polish, while the pebbles are of grMt 
{brightness. 

19. Very small pebbles, of almost mrery Uh 
Jour, in a bright yellow cement Exquiiifely 
beautiitiL 

20# A pebble, about two and a half inched by 
one and a half, which is not only a pebUe bat 
a koUanite, as it contains distinct agatised pel^ 
bles*. 

When the origin^ sites of this stone are €9e- 
amined by persons of real skill, it is probAUe 
that a vast number of interesting varieties wiH 
be discovered. Meanwhile it is hoped the reefer 
will not blame some degree of prolixity coaoenh 

* Those only are described which are in the author*8 collectkxi. 
or which he has himself seen. The rare green probably co&taio* 
greeti pebbles In a yellow cement. 



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lag thit ttDgoIar substance, which has nor^r htta 
carafiilly examined, and concerning which M 
many errors have been propagated both at home 
and abroad. 



NOME IX. TOPAZ ROCK. 

This beautifol 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 primitire rocks we have 
now to describe, are less important than thosA 
we have already described, because they dceur 
less abundantly, and not so widdy exited. 
One of the most remarkable of these is the topax 
rooky which is not only remarkable on account 
of its cotistitQ^it parts, but also its structure* 
It is composed of quartz, topaz, schorl, and a 
small portion of tithomarge. The quarfce is fine 
granular ; the schorl thin prismatic ; the fopa^ 
Usually coarse and fine granular, and has com- 
iadonly 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- 



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128 DOMAIN IS* AVOMALOUf. 

evilar large granular masses, so that the topaz 
rock appears large graiiular 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 
scliorl and lithomarge, of the same colour as the 
topaz. 

** 2. Its stratification is uncommonly distinct 
'* S. Its geognostic position has not been hi^ 
iherto satisfadtorily ascertained. It appeatrs to 
lie on gneiss, and under clay ^late. 
• " 4. It is a very rare rock, having been hi- 
theito found only in one place in Germaoy, near 
the town of Auerbach, in the Saxon part of 
Yoigtland, where it forms a mountain mass at 
considerable extent, and is there known by the 
name of Schneckenstein. A rock, compoaed of 
topaz, beryl, quartz, and hthomai*ge, occurs m 
the mountain of Odontschdon, and in the neigh- 
bourhood of Mursinsk, in Siberia, which reseoH 
bles topaz rock, and is suspected to be the sanw 
' with that of Auerbach. The schorl-rock of 
Cornwall is probably very intimately connected 
with topaz rock/' * 

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

* Jameson 8 Min. ill. 141. 



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HOME Z. JACINT SOCK. ]£9 

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 ; but from the summit 
rises, like a tower, the topa^ rock, being about 
eighty feet in height, and three times as broad. 
But we are still to learn the composition of the 
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 
jacint, so that it may be called jacint rock f. 

• Among the ejections of Vesuviua there occurs what may be 
caHed Chiysolite rock« that gem even sometimes serving as a base ; * 
bat these fragments^ placed by Gmelin among the locks^ may per« 
hapa bf mere vein*stooes, or mtiy oeeur in small quantities. Pe^> 
haps rocks of Corindon may be discovered. It "was known to 
Woodvrard by the name of Telia Corivindum, and Neilo Coru 
tendum. 

t Sauas. § 1903. 



VOJU II. 



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ISO DOHAm IX. ANOMALOOfw 



NOME XL BERYL ROCK. 

. This WAS discoYered in France, near Limoges^ 
by le Uevre. It had been used in paYing the 
highway, and is seldom of a good colour, bemg 
generally €i£ a greyish white, thongh some s{ieci« 
mens offer a tint of green. It is howerer rather 
a vein-stone, though found in large masses, as it 
runs through the middle of a vein of quartz in a 
granitic region*. 



NOME Xn. GARNET ROCK. 

' The red garnet, of which this beautiful rock 
is chiefly composed, contains from 20 to 41 
parts of iron, according to analyses of Klaproth 
and Vauquelin. The green garnet is even some- 
times fused as an ore of iron. 

In his System of Mineralogy, Cronstedt re« 
gi^rded the garnet as entitled to a peculiar place 
in the rank of earths ; a singularity which woidd 
seem to show that he had a distant yidw of the 

• Fanjas, G«dlogie» Pum IBOQ, vol. ii. part i. p.' SOS. See parti* 
cttlariy Journal det Mines, ▼. 641. The analjw of VauqudyLft 
fbtiod the tame ingredients as in the emeiald. 



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

This curious rock seems unknown in any sys* 
ton of mineralogy, except Mr. Rirwan's, who 
says, ** Gamet'Tock of Karslen, found by hini 
near Winnebnrg : it consists of amorphous gaN 
net, in which trap, quartz, calcareous spar, and 
B very small quantity of blackish brown mica are 
foand."* 

But the garnet rock, recently discorered in 
Scotland, seems to consist of that matter minute 
ly interspersed among stderite and felspar, with 
Jargef or smaller globules, or imperfect crjrstab 
of garnet. In some parts it seems to approack 
to slaty siderite, penetrated with garnet ; as it is 
common for that schistus to contain garnets. 

The surface is brown from the decomposition 
of iron ; ,^d the garnets are of a ooarse texture^ 
and irregular form. 

STRTJCTtTItB L 

Amorphous garnet rock, containbg trap,, qoarts, 
calcareous spar, and mica, from Winnehui^g. 



• MiD.i. 368. TheScotbhmay betheiockwithgnuntofgamel 
hom Sweden^ Norvif, &c. JUim. I GmdiB, 8S3. The 8amm 
M^lanGrmiflAcmm, cWbrerii2'<iite« of Walkrifitk tanNtcMiftia 
Sweden. 

Kfi 



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\3i .BOHAIV IX. ANOKALOU0W 



STRUCTURB If. 



, Garnet rock, interspersed with siderite, felspar, 
and spangles of brown mica, from Portsoy in 
Scotland. 

: It seems essential to tliis rock that the garnet 
•jnatter should be dispersed throughout ; otherwise 
gigantic and common garnets are sometimes so 
jclodely mingled in mica slate, that the rock might 
•iail under this denomination. • 

The garnet trap of Saussure, §2258, of abrownisb 
:green colour, composed of a mixture of particles 
of steatite, fibrous hornblende, and mica, including 
<many little garnets of a dull red ? 



NOME Xin. SHORL ROCK. 

This rock is chiefly composed of the common 
black shorP, the black tourmaline of Hauy, 
which, according to Klaproth, contains 22 parts 
,of iron. It is common in granite, gneiss, and 
other primitive rocks; but is sometimes found to 
form a rock by itself, or mixed with quartz. It 

' * Hie word a original, and not derived from the town of Shofkor 
as appears from the term Shkl, used by the Cocniih minen in the 

same sense. 



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KOWB XIV. ACTIVOTS ftOCK. 133 

must not be confounded with the shorl en masse j 
of Saussure, and other French mineralogists, 
which is siderite. 

Shorl rock is not uncommon in Cornwall \ the 
substance being generally, if not always, in small 
crystals, sometimes disposed in tratisverse tadia-' 
tions. 

STRUCrURB I. BKTIRB. 

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

STRUCTURB If. 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. 

Sansfiure describes, § 2281, entire rocks com* 
posed of grey delphinite ; a kind of glassy acti« 
note. 

• Outlines, i. 235. 



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\ 

NOME XV. MARBLE OF MAJORCA. 

This rook is of a singular and anomalouB. 
structure^ as die Bhape of the spots, or concre- 
tions, resembles that of almonds. It is black, 
and white, and takes a very fine polish. The 
natives call it amandrudo* . It is found near 
Alaro^ in the island of Majorca. 

s 

NOME XVI. MARBLE OF CAMPAN. 

This marble, so well known in France, is 
found in the Pyrenees, not far from Bagneres. 
It is either red or green ; and both colours even 
occur in a small specimen ; but it is greatly con- 
taminated with argil, as before mentioned. It is 
rauked 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* Ramond observed another niarble in thafc 
vicinity, analogous to that of Campan, '* that 
is to say, with a white base, veined with red and 

* Laborde*8 Spain^ liL 448. 



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SOMB XTIK FROSMMBIXB. ]5^ 

green by steatitic clays ; it contains a nmnber of / 
conical nodales, 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. 

Ked guttular marble of Campan« 

BTPONOMB II. 

Green« 



NOME XVn. PHOSPHORITE. 

This rock is reported by some to form hills, 
and by others only thick strata, in the province 
9f Estremadura, in Spain. It is said somewhat 
to resemble curved laminar barytes ; and is of a 
yellowish white colour, often spotted with yel- 
loinsh grey. It is a combination of lime, and 
phosphoric acid, the latter amounting to S4. It 
is rather soft, and brittle, and translucent on tb^ 
edges. 

Brochant says that its site is at Logrosan near 

* Ramondj Voy. an Mont Fndn^ p. 99. 



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136 IKUIMV IX. AVOMALO0S. 

TnixiHo, in beds mingled with quarte, and in 
sQch abundance as to form a hill. It was known 
for a l^ng time to the inhabitants by its property 
of yielding a phosphoric light. In 1788, Proust 
first indicated its nature, in the Journal de Phy^ 
siqu^. 



NOME XVm. GLOBULAR ROCK. 

This anomaly was discovered by Saussur^, in 
a hill not far from Hyeres/ in the South of 
France. As his important work has never been 
translated, an 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, disposfed in concentric layers, and each of 
these layers formed by an assemblage of needles, 
converging towards thie 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; the smallest, two or three 

• Min. i. 58^. 



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MOMS ZVm. OLOMTLAB BOCK. 19 ^ 

inches : some are seen also of an elongated form ; 
but the layers are always concentric, and cooi- 
poaed of parts converging 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 
Ba>all, often intermix and arrange themselves in 
strange fbnnsj and nevertheless the whole is 
disposed in beds pretty regular, a little inclined, 
rising to the nort4i or north-east. 

" The spar which forms these balls, is of 
hoiiey*yeliow, 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 wbioh is essentially the same. 

** One cannot.but 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* 



menon.*'* 



• 5aiia8. 5 1478- 



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I3S « »eMAIir IX. AVOKALOOa. 



NOME XIX. BARVnC &OCK. 

Mr. Kirwan informs us, that Hoepfner disco- 
Tered a whole moiiDtain in Swisserland^ composed 
of quartz, barytas^ and. mica partly, cpmpou&ded 
with shorl. Mr. Kirwan ceiHh this kind of ba* 
rytes, baroselenite ; because it resembles Mlenitej 
or gypsum crystallised in pl^epL It is the planei 
kuninar, heavy spar of Werneft io which the 
most coqimon colours are white and red. Iq 
the curious rock here mentioned, the barytes 
was of a flesh red colour ; bnt i^ must not be 
forgotten ^that Hpepfuer's ohservatipxis ^md aoa^ 
lyses are not of the first authority ; and his ba*' 
rytes may be found to be a felspar. 

In the mineralogy of the department of the 
Loire, there is the following account of a singiular 
rock near Ambierle, a village near three les^ues 
N. W.ofRoanne*. 

<< There is there seen a rock, situated betweea 
two little valleys, on the eastern side of the bill. 
This rock, which separates these two valleys, is 
a disordered mass, composed of fluor and barytes, 
sometimes mixed, sometimes in separate and dis- 
tinct parts, but always in intimate contact, and 

* Journal des Mines, !▼. 127s by Passing^. 



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ttOMB xut. MAxme motm* 139 

trafrersed by some veins <^qoartz. The flaor ii 
of varioas coloars : green^ violet, and reddish { 
yielding oiiicb phosphwescence when thrown on 
hot iron, as well as a spathose acid gas, very aerid 
and corrosive, when it is heated with vitriolic 
acid. The barytes is white, with a slight tinge 
of red, very pure, and disposed in lai^ plates. 
It is sometimes crossed with veins of a beantiful 
pitch-stone, of a deep yeflow, a little transpa- 
rent, bat sometimes opake, and resembling yel<( 
low resin. 

<* The texture of this pitch-stone is rather 
loose, and it seldom strikes fire with steel ; bnt 
in its fracture it shows the conchoidal form, as / 

well a^ the convolved streaks of silex; while 
some, in a state of decomposition, leave a lilac 
coloured eailh, 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 
metal, 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* 
posited new layers of the same fluor, and of 
quartz of different colours, till the cavity, in 
which, the first crystals were formed, was filled 
up. This frequent mixture of different sub- 
stances forms veins in zigzags because they fol-* 



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140 nttMAIH IX* ANOMALOOl. 

lowed in their deposition the unequal angles of 
the cubes, which served them as a base. Some 
of tho^e flttors have shown indications of the ozy d 
of cobalt, others of manganese in stalagmites. 
Only one piece of flnor has been found travel^ 
by the same pitch-stone: there are also found, 
but rarely, small cavities which contain little 
crystals of fluor, barytes, and quartz. 

** It may be judged by the quantity of frag* 
ntients scattered around this rock,, and in the sur- 
rounding vineyards, that it has been of a far 
greater heigh t^ and that it has been injured and 
shattered from many causes, but especiallyi the 
cultivation of the neighbouring vineyards; there 
are even large open slits, which show that it has 
been shaken. It has even been attempted to 
mak^ milUstones with the barytes, of wbicii 
there are large masses, but the attempt did not 
succeed. All 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- 
senting. adherent mixtures of various kinds. 

'< The environs of this remarkable hill show, 
in the hollow roads, veins of barytes amidst flaor. 
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 



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ntmm %x. tAUUBmocmti 141 

supports and traTerses of doors and windows, re^ 
sisting the air a considerable time. It is to be 
.presumed that mines may be diacor«ed in this 
district, though nothing in that way has bee» 
attenapfed. Some cubic pyrites, yellow or black 
on the surface, give no strong hope iu that 
respect,** 

Some important rocks must now be cpnsider- 
ed> which are not only anomalous in their stittc* 
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. SAUNE ROCKS. 

The most remarkable of these exist in Spain 
and Africa. The latter saline hill can only b^ 
said to have been observed ; but tbo9e of Spain 
have been described by Bowles, in his natpral 
history of that country*. The first is in Spanish 
Navarre, between Caparoso and the river Ebro, 
in a chain of hills which extend from east to 
west. 

• See the French translation, hy Viscount Flavigny, Parh 1 776, 
Sto. p. 376, 406. 



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14j| mCUATH IX. . AMOKAXiKTS.' 

Of NaftfK. *' These hills/' says he, <' are composed of 
limestone mingled with gypsiun ; the chain ex* 
tending more than two leagues. In the most 
derated part is situated the village of Valtierra^ 
on a slope towards the middle of which is found 
a mine of rock-salt It may be abont 400 paces 
long, and 80 wide. The salt is contained in a 
space of about five feet elevation. 

^< i examined," he adds, '* with attention those 
beds of salt ; I compared them with tlie layers of 
eardh and gypsum in which it is imbedded ; I 
found the outside layei^ to be composed of gyp* 
sum; and immediately afterwards I met with 
two inches of white salt, 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 the mine, which is of gypsum^ 
undulated like the other layers. The layers of 
saline rock are of a dusky blue, those of salt are 
white. 

**This mine," adds Bowles, " is consider- 
ably elevated above the sea; for you ascend 
continually all the way from Bayonne." 

The second bill is far more memorable, and is 
even very extraordinary : it is that of Cardona, 
in Catalonia, l6 leagues to the N. W. of Barce- 
lona, and a few leagues from the Pynenees. 
Of Ctfdm. *^ The village of Cardona," says he, ** b sitiw 



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zJbeA at the feet of a rock of salt» which from the 
side of the river Cardonere, seems nearly murals 
Tbia rock is a block of massive salt, which rises 
from the earth aboat 4 or 500 feet, wi^ont cre^ 
vices, chasms, or layers: no gypsum is found 
Bear it. This block is about a league in dr« 
cumfefence i and its elevation is equal with that 
of the surrounding mountains^ as ks depth i« 
not kttown, it is imposlafale to say on i^at it 
pests. 

^* In genera], the salt from the top to the bot- 
tom is vrhite, though some parts are red ; some, 
is also fimnd of a iine blue. 

^ This prodigious mountain of salt, destitute 
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 ibimed bjr 
an evaporation of the sea ^ such a sdution might 
not satisfy every one." > 

The salt mines of England are well knovtrn^ 
but are not elevated above the ground. The 
same observatioti applies to the grand and cele- 
brated mine of Wieliczka, in that part of the 
former kingdom bf Poland called Galitz, once 
ceded to Austria. Smaller mines of salt are also 
found it Thorda, Bees, and Eperies, all in Hun^ 
^cy. 
But the most remarkable mines of salt^ after 



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144 



Of Pern. 



■ccoaot. 



tlriwe in Spain aQd Africa^ are in Peru; and 
Urns described by UUoa, who sajrs they are 
situated at the surprising height of 10 or IS/NM 
feet^ on the grand chain <^ the Andes. 

" The highest part of Peru/' say« UMoa, 
*< which seems to be a depot of .minerals, hss^ 
also mines of salt. It is found in hard Idoe^ 
and continuous like the rock. The exterior form 
of this salt strikes at first sight ; for it resembfet 
a stone of a dull violet colour, strewed with nj% 
of jasper. • 

** These mines of salt are found neariy all oter 
the country ; and what is most worthy of re* 
mark, is its extreme hardness, its colour, and 
that it should be in those mountains equaOy as 
high as those which yield silver or merairy> 
which is certainly extraordinary."* 
. Mr. Kirwan has treated this subject with his 
usual mineralogic erudition. 

" Many mountains, entirely consisting of salt^ 
have been discovered. The salt mountain of 
Cardona, in Valentia, is from 4 to 500 feet high, 
and about three miles in circumference. Bowks, 
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. 35S. 



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MOMB XX* 8AUWB BOOKS* 145 

S99; aiid«H>ther in the province of Astnchan, 
3 Buff. Mifa..8yo* p. 371 : tlie salt in this, how- 
ever, contains a mixture of foreign ingredients, 
tbe nature of which has not been accnrately de- 
termined. The salt of the mountain Jibbel 
HadiiFa is of a purplish colour, and bitter; bat 
whether the bitterness proceeds from glaober^ or 
nuiriated 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 bittern^ 
is easily 'mashed out. In the province oi Yak- 
outz, in Siberia, near the river Kaptindei, there 
is a mountain of salt 180 feet high, and 120 in 
length ; 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 thinks, has been 
the cause of destruction of many of them, and 
at this day promotes the decomposition of many 
that still exist; hence he derives the saliniferous, 
sandy plains of Siberia, 4 Nev. Nord. Betr, 167> 
174: bnt it more commonly, at least, proceeds 
from salt springs beneath the sand. See 1 Her- 
man Uber die Uralisck Erze Gebirge, 36.*** 

» Kirwan Gto\. Ess. 373. For the Salt Mountains of Persia* see 
Olearius. 

VOL. II. L 



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140 mamMm au Avamujm%^ 



itasiiBtiiat be fa r g o tteii tfcat a awiHtaiiii «€ 
aflh ha0 mcentfy ban dUcotveiecl oft the wcBtcrft 
aide of tb» nter M&sonri^ ht Hottii Aatcnca.. 

]i»tb»8dtauiiie8o££i^;iland, VictetodnevfeA 
a singHlfli tftnicter^ aomentluit Msemblt^f Aat: 
a£ basaltic celMDini Inthoieo£Pbbn4.«iiau« 
bur potygonat sttuctoce. bat afa» b6e» obfCTMd^ 
b«t was supposed to SHriw from bnrge gkboks 
compMBoi oa alt sidles by olbciau Furtbec cqi»* 
sidarationffoo rack-sah may be fcuod ia magr 
■liatridogical tieatitMo;. and aw scamnly Mqu> 
site in a wovk o£ tina nature**. 

HtBOaOBB u 

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



* l*h«ii«ftntiiGa»tiirf|iiDdligiM]ifiad(safic»in 

work. 



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voxst ujr« svtmaiattt aocKi. 147 



IfOME XXI. BTTCMINOUS HOCKS. 

Tlw^ ctoief bitaimiiQMO snlbefcafKes are neyMii^ 
«(f |i9nr ro^ QBt» 2^. §fmt and ttansparont ai 
wtiMsi ftetro^vfaiGhialewjfliiidaiidpwf^iriiwia 
U; ia jpfc noie hnpiire k becoiBM oMDec^ taft 
Of nMUal piAcb tbeve «« thiee diireraJtiM: 
MaRha, cf a broiraish cdoor and eaaldb^ coor 
Mnetion; Aypkall^ pure aad black;.mi tile 
dasttQ) or ndoeral Gaovtehoa. 

Al) tihe btemMDa bdong mom strM^ to the 
province of chemists, who now arraqgo thoaa 
afbr tte legctaUe whatancoiw from w1mI> Kke 
coaUthfji^aMmtaWd^wd. ^ 

Tkoj «re mMt common) jr foond in ^ proMr otncarti. 
mitar ^tlktt mmf^h and in ita moak wmX ^ 

SybovHi, Mhhrmh bw even 1>««[| obtervod in btflb 
fiC «MeedQ«7, It aMnttiiiw Also «p]M*r4 is 
•Hmt ^lAl tmT«»e tb»t Mrg^mAQ«oq» i^toi^t^ 

apwr m iMstkan, or tb« ti«»«lm fraiwleiii q£ 
Wetter. The «4>lMtt imwwts ui nmwrtl Toin^ 
UMlb««A««M:hoa. TtM^biefUlwMMqKreeluk 



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met being generally black, as at Sefeld» ia 
Tyrol. 

The grandest appearance of that natnre is at 
Baku, on the western side of the Caspian Sea ; 
whence it is supposed that this substance was 
brought to Constantiooi^Ie, where it formed ilie 
chirf ingredient of the «ioted compesi^n ciAed 
the Grreeian fire; which, burning with i nc r c aw rf 
intensity under water, became a most femidi^ 
ble instrument against an inimical fleet Fraft 
the description given by Hanway, it would «p* 
pear that the rock is limestone. His aocounfeef 
this singular phenomenon deserves to be here 
Mpeated. 
Nap^of ^ The earth round this place, for aboVe M« 
miles, has this surprising property, dia^ by 
trinug up two or three inches of the nu&ce, 
and applymg a live coal, the part whicAi itf m 
encovered immediately takes fire^ abnost I 
the coid touches the earth : the flame I 
soil hot, but does not consume it, nor 
what is near it with any degree of heat Aatf 
quantity of this earth carried to another plaoe^ 
does liot produce this effect. Not kNig sinoe^ 
eight horses were consumed by this fire, 
under a roof where the surface of the ground \ 
turned up, and by some accident took flame. 



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VOBB XSI. MTOMMtUrt' MCKS. ' 1 4C) 

«* If « oane or tsbe, ev«n of paper, be set 
abbuttwo inches in the gfoatid, confitied and 
dk>se wilh the earth betow, akid tfeie^top of H 
tottehed with a live ooal, and blo*«»a upo^, imw 
madiatelj a flame i«nia, withoad hurting either 
the cana or paper , provided the edges he covered 
with cd^ ; and this meAad they use for light in 
their faoQses> which have only the earth for the 
floor : three or four ai these lighted canes wiN 
b(»l water in a pot, and thus they dress their 
yiotnals. The flame may he extingoished in the 
same n^anner 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, Uke naptha, 
bat not very offensive. 

<* Lime is burnt to great perfection by means 
of thispheiiomenon; the flame commiwicafittg 
itself io any distance, where the earth is unco* 
verad to receive it The stones must be laid on 
one another, and in three days the liilie is com- 
pleted. Kear this place brimstone is dug, and 
naptha springs are found. 

f^The chief place for the bhK^k or dark grey 
naiMia, 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 



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i50 90mmK «b» niroiuaioim. 



m c%iteni wkh.it for lei^^Ks ^ogeHhstL When 
tbe w^afberis tlmdc^nd faacgrj «!» BpnidgB'lMl 
llp.^he^islMri; wid Aite tia{idm eAen takes <r 
Oft tlie^iiir&oe>of feiweifth^ «iAT«ta»in a1 
jolo .the «M hi :gpBat quaBtiiin^ to a 
wlmmtwitfeiMeu la casirivioalfaer die i 
A> *et bfiiil «p shore «iKb nor ttfarce ieet« m Ml^ 
inf 'Ovev^ this 'Oiljr eobsmce vahes m iH^omg a 
iCMiaisteBcy^ M iiy degrees ab&ctft «e dfoie the 
ilMll}th^the«pria^; sDraetimesitisiqaitotiloied, 
4MK144WI* iUtiocfcs $hat took w blaclc as friMh^, 
^«l the «|Mrii)g irinoh .is lOMted ift one.pi0De^ 
Suedes -out m atiotiier. Some of the springs 
«i4imA hwe net been faiig'Opeaed^ibvaiaaioiith 

*^ The people carry the mqUBoi, tnf tMnigk% 
ittle ^itHor iresenrans ^ thmwhag it ofFiGme ane to 
eetottiHii, Jeaviogmitlie (first rmsenmrilbeva^ 
iMT tJie thetfrier ptftt ^vilfa ^ich k is «aL^ 
it «iMies iirwi Aheiipniig. It is n iB|il i ' i wiuit telhe 
sfgMyhwi used noElly aiaoiigM rtbe f^ierar soft 
ftf <the JP^niaM, taoddther Kje^kbamig peopl^b 
as we use oil in lamps» <or ^to inl lAwir^iDlMlB^ 
htttutroevmuiaeMes^ dieagfeeable itttta They 
find it bwn best ^wNh « 4mdll aBUDtareof airibesr 
aB4hqy^^ttd4t in great ^hiitdmoc, evengr faaafy 
is well siippfied. They iheep it at m mmdl ^d» 
la&ce iwm ti^jr Jiwrif s^«iMa0teai«Meb» mder 



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Mcxs. m 



it is extremely sasceptible. 

^ ThiNe is.diOB white napAa on the peaim- 

«Bift«fiAq^cno,><tfaii«ichtUBBttx^^ 

hntiiM IB tmoA oidf m anatt qoaaiiiDes. Dit 

flmsMis^dnDk it both .n a QMdUl aadm medi** 

0«MW tet d^ iw8 w>t ifliwfeates d^^telcmaiiter* 

jMillir^it ii^siM;tei^gMdi[»rlte.«taae» as alio 

&F g fao i Jfl i i ofiibe faneatt» and in nreneraal <tMi^ 

andaorefamis^ toJkotktfieiaiAlhefetmiisaae 

Migr aidv€i:t« EKtQrnaHjr appKidU it risiof igreat 

use in scorbutic fwiost i^ootiw crampa, A;jc«9 ifaat 

itifliii»tbefNitAa4beiiait(«iwtedaa)7i; itfwne- 

imtas JMlantMMmly intoibe tioad^ wioso^H 

lar ^ 9^rt twae 4a ereMe igaaat pan« It has 

vbaitiiefmpartjiof spints nf Nnn€w to take oat 

{paaty^ipataanii^ nratanlans ; hat thei'eaMariijr 

»a ^liiMaa Am IhadiaaaaQ, frr k Aeams an afboB^ 

MUeKMlaw, Tiba^Miritis QMrtodiiata iMba 

as a iipMfe maitj ; aaid« beia^ iifWMiri jui a 

japan, is jiieaaoit Iheaaitift i i aad ihrtiay afrnqp" 

that has yet been found. Not far from hence 

are also springs of h^t m^Jb^r^ which boil up 

in the aame manner as the naptha, and very 

thick, bakig riayirgnaiial <#ith -a Miie -day ; 

but it 80<Hi clarifies. Bathing in this warm 

wateris foandto aitrngfyhm^md procure a good 



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15B stmmtktm nc ahoujo^v* ' 

appetite^ especially if a vmall qnantttjr 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 ooarse mail, 
mixed with sand, and effervescing with acids. 
There are many other wells in an adjoining pe- 
ninsula ; and the revenue arising from this an* 
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 qusmtities. The mineral tar of 
Cold>rook Dale is obtained from a sandstone: 
and William^ has observed many bitominona 
rocks in Scodand. Bituminous shale and inarl 
are not uncommon; but the whole Mbject re-» 
quires and deserves further illustration. 

• 

HYFONOME r. 

X^imestone with naptha, ^ with petrol. 



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vaan sxn. suuatmic mocKs. MB 

HYPONOMB IK 

Sandstone with mineral tar. 

HT70N0MB III., 

Mumia or asphalt, 'm the rock, from Persia. 
MkroMmel. Bituminous shale. 
JkGcMfwme 2. MarL 
" MkrcmmtS. limestone wiA caoatehou. 

NOME XXn. SULPHURIC ROCKS. 

The p}nritic rocks, as has been already ear* 
plained^ are generally arranged in the respectiye 
modes of the substances in whkh they are ibutid ; 
pyrites bmog, like rnica^ of almost uniyensld 
occurrence, and nowise considered as altering 
even the structure of the stone. 

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



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'^ Natural sulphur commouly occurs in masses, 
in gypsum, limestone, and marl. Near Artem» 
it occurs along with honey*stone and bituminous 
wood. 

** It is sometimes found in veins that traverse 
primitive rocks ; in veins t^ copper pyrites, that 
travaese goanile at Sehwartziw^ am Smibn* in 
Siberia, in the gold mines of Catherineburg, 
and in leadg^Uaoe mi&s in the Aitmuk suMin- 
tains. 

'^ It occurs also in netis iin limeiteDe, m Ire- 
land; in sandstone, at Budoshegy, in Transyl* 
vania^ Akong M«ft nei aMOganeie-Arew «t lE»p- 
nik; and with red orpiment, at Felsobanya. 

*^ Very lately, the celebrated and enterprising 
Prussian icavellec. Vim HumhoLlt» conflnmii- 
cated to the National Institute of France, a note» 
itt whfcoh he Bietfti#M his ham^-diiOMeiad^ in 
4h& ]piPo«moe totQmto^ -hatween Aimmi iaftd Hie* 

wnmntiin ftfiaioa slate; md^dsD gnefit^uasifilMS 
«f Bi4pbttr in fnwaiitw piii|dijry."* 

Porphyry "vnt&i sulphur. 

* *** Ammlcs -de Moseuin Nsriional, cahier 17/* Jameson Mia. 
ii.40. 



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158 



HYFONOMB II. 

Mica slate Wi£h the ^ame. 

HTPONOMB III. 

limestoDe with &u]|pbun 



vr. 

iSttndstow. 



^WME xxm. moTX mus. 

In Us xxinooft work ««f ipiiyBioal ge^gmfkf^ 
BocgflMa inKamfi us lliat 4here is 4bi vnoMtaiti 
asarTomm, m BoUoiia^ lentivefy oMunstittg df 
imsk^mt* in iLuko Lnpfamd, ftbe mMmtain •itf 
'GdUisaris oneiBDliire man of rich mnH»e, of m 
UftokoA Mae «ola«r, cxtenAing like an frregvlflnr 
urai tat more than la Jti]le» wad af a tiy dB i eai 
ifiMa S la 400 ^rtfaons. HetdMJiofanBft «8 tbtft 
(the two moBDtaiiis of £ienma)mna and of lou^ 
^soipara, in Bitea Lapiaad» only eeparatal %>f a 
-anall valley.^ «re entirely JcampMel ajf in(m<(0re. 
TfaiB iroii» as iie describes, is called virgin enr 
native iron; to distinguish it from what were 



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156 BOMAIH IX. AtfMIALaOl. 

called mineralised^ as being mixed with sof- 
phur*^ 

This father of modem mineralogy has moie 
minutely described the hill of Taberg^ in Smo- 
land, in the southern part of Sweden j 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 bard. Berg- 
man's description follows. 
Berirman's '^ Amoug the most singular mines of iroe, 
*TaWg? may be reckoned that of Taberg, in Smoland: 
it extends from the N. N. W. to the S. S. E. risiog 
gently on the northern side to a coasidefable 
height ; then sinks a Utile, and agaia rises^ fiimi- 
ing at last a very high crest, and t^minating m 
.an. abrupt cliff towards the river l^ii8arpa» 
above which its summit is elevated 480 feet tb 
the S. £. and on the other side of the river is a 
corresponding height ; to the £. and & W« these 
is a succession of heights, equally sepaialei 
..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 oivirons of Joik- 
koping and of Taberg, as fitr as the district ^ 

• Journal des Mines, No. l6, p. 58, 23. 



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noitt x^iii. isoir HRXi; 157 

Oesbo^ the soil is a movable sand. Near the 
cliff are large collections of ferruginous ore, 
without any intermixture of stones ; some being 
several feet thick. They are placed in horizon* 
tal layers, separated by strata of earth, 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* 
iDg the direction of the mountain ; 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): theycontaiif 
a blackish brown and shining ore, which yields 
thirty-two pounds and a half in the hundred 
weight. The common one 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 pre^nts, is well calculated to excite curio- 

• The Swedish t\\ is only two feet 



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]^ of the kinA fbat oatwe vSen te na"* 
Fktrini Patrin has observed oa thb dcecrtfriaoa^ Auk 
Taberg,. fur &cm h&ug aa irregvMt imss q€ < 



ison the contoaij a s&oamtlaii of amoet fegulM 
stractare; thearrMti>or«pn9htst>lMiwiglA«i« 
flmts pacaJtel to ite great vMx u is gpeMtattjr 
obserT^d in primitrffe movntaiiDS. 

Tht sum aMe aibserrer^ who i^assed maiijr 
jeaxs nk Sabeni^ thw proceeds : 

'« The miiieo of ijroD in ¥ems, whkh I obaerfed 
mSitertayin ib& Uial Bi0iimtattSj.hflare a singdbr 
lesonUaBce to* tfenae of Swednt. 

^ The tiKo prineipat onea are those of Blago^ 
dal aadofKeskanaF^botKupoQ the eastern sideof 
tbeUiaHaaefaaiii^ the fin* tfairt;, andtheethof 
fiAj» leagues to the north of Ekatataharg. 
BUigodat. ^ Bhqiodat^ bke Taberg, ia a monntaie about 
460 feet ia heigl^ in which the upright veutt 
nut fnoa noEth to souths as the ehain itael^ 

c< The sonttnit is afanoat enthreljr eoaeipoaed of 
ore» for an estent of tOO firiihoms in lengA aad 



• Ikay. 

in mineralogical langiuge, lamented by Saussure and many othe^ 
writers ; the expressions of vertictd bedt, or vertiaU layers, being 
highly objectiondds. 



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l«t 



100 m hmmikh. Tke T«iii% wUek •» Mreral 

hy tayvMof i€UBtii% »da kiad oiUwp^ vkkh 
aff» scwedy wo thicL 

^ The OTO k of llw Uflck Minpicikiiid, niMli 
affected by the magnet 1^ ityieUBfiOper eeabm 
affbidi mMt exctlkot iri&. 
Thtte Me aanaaUf extneled from thm 
1 1 vo> aidiioin of poimds^ or alMMit flfivett 
kaadiaeil tiiQiMnid quuKtsda of an. 

^* The monntain of Keskanar has a fimibr 
stractere; ifciafamow for the kNHbtmea it has 
ygodact d ; Ubcks of 40 pswwh veigkt of H 
have beea found, which notfU cany two hoo^ 
ixfsdiwoight; Iba anaK loadrtoMs bad in pro- 
pOftioB a aonicb greater sftreagtk^ ame Iwre 
beeiK aoeft whicb wodd canijF Iweaitj^fiRie tisMa 
tbete ownweiii^bt Thisn^swft is mndk wilk a 
G««»]ikraUe fnanltiy of greeaish hoanUbiide^ 
wUck is dispersed thro«igtk it m snatt neais aome 
fines in diameter^ aad whick is yerjr glisteaing 
when tbfi stone is poKsktd* 

** There are ako kadstones in fte moantain 
of fifaigodaiy and one of its sunuBits ia catirety 
cSHapoaed of theafe^ bi^ tkejr hwe a siugalar de- 
feck : \Bhen they are detached from the movBh 
tain, their poles midtifdy aad iatefmioi^ and 
they keeonte naeksB. 



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]0O s6MAiir IX. akoWaious; 

^* The same sammit offers another smgularity ; 
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, and 
which is entirdy covered with moimtain bhie 
and green. Since it has been in. my collectioa 
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 severe! 
places rich in iron-ore ; but it is not wrought, oa 
account of the distance. 

*^ In that part of those mountains which the 
river Ictish crosses, when it quits the lake ZaiEs- 
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 schistus, the thin 
layers of which are exactly perpendicular, and 
alternate 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 th$it 



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XKUt. ladir Hiuj. |$| 

.bmyilMed vemd of iro»»or&; and tkoogh 
thttjpK 9K ilmre iacomparaUy more frequent than 
^Bewbeie, they are* neverthdesa fi>nad in more 
tiimpCTate cooBtries, Striking examples are seen 
in the monntiun of Eisaiierts, in Stiria; and in 
tkat of Bk>» in the idand of Elba. 

«^ The monntain of EiMnerta is 3000 feet per- 
peadienlar; you there find almost every when 
abondaace of iron«ore^ especially at its summit : 
it is for the most part steel-ore; that is, car^ 
Inmate of iron> or spathose iron^ore; and it is 
weU ipMwn that this species of ore is never fimnd 
iNitiirTeins.'^ 

He then proceeds to state that the mine of 
Sto^ in the isle of Elba^ celebmted for this metal 
smce the time of Vii^iU may be said to be a 
mountain of iron. It now presents only disorders 
the rock which separated the arrects having been 
decomposed^ and seeming now to appear in the 
form of a white boIe« 

mrK>3ioiis I. MtmBM. 
Iron rock. 

BUfOVOUM n. UUMD. 

With quartz. 

* Bum Mm. V. IS. 
VOL. II. JC. 



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1^ DOMAIN UU AMMALMIt^ 

This sufcipect canwt be qinMA loliMMt tln^b# 
^erva^OD, that there a^ema a moat mailifefll ndn 
eatioii of JMiKix and BESfON, or in other words of 
% ffGSLt Creator, in die peculuir distritetkNEi of 
Ihis metal ia fte northern parts of £ilra|w;^ where 
He knew, to whom all timea are present^ Ifait it 
would be necessary for the m dust 17 of tne ioha- 
bi|Ant3. In like manner the increased iMdaim of 
th*far, or of the feMheiy down of aiiknali, can 
scarcely bo atuibutcd to climate or cliauce : neit to 
add another simpie observation^ tmt whkb dc«?9 
mt-seem to ham bera madp, namely/ tte superior 
size and strength of the female, wheaccmipareci 
^riththemate/sekly among the l^ds of prey; as 
lb was necessary that she should hodi pratect and 
Sied< her vefracious offtpsing. 




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../..,. .7 .1 



■-- :; '■'! r- 



■i-ci3u :^^v •' i- 







DOMAIN X. 
TRANSltlENT. 



XHIS idivuioQ ^incliuks the rocks Mrhidt 
a>ddei% pass firDm-bn^ to'ftiietb&r, «o tliat 
speckne^ats^y 80ii)i|tiii»9ft ev«t appear ia 
eabiiiett; 'irliIe4ltd'fialksiti«e'rodc8 coiiik 
monlj iocciir iikb ilo^^^^l JCalpeely risible 
progress > the 4«ria il^^ying, in Wemei't 
system, ti^iose* intenuedibte betHtreea the 
I^nailiT^axid^Seoondary. Thesuddenoest 

m8 



DMaetftM 



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\^ DOMAIN X. TBAV8ILIBRT. 

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

These rocks are extremelj inter^ting la 
the study of Geology; and the learned 
reader will observe* that this trerfllse feom 
a gradual introduction to tlm^ ^tihrmie 
science, or rather. 9tudjfrf^>r^ the 

German sense of t?ibognosy, ir! i 1^ 

of the shell of the earth, it can scared/ 
ever be supposed to arrive at the perfectioo 
of a science. ' ' • » 

Dkthietfrom Great care must be exerted not to con- 
found the rocks which are merely adhanent, 
or composite, with those that really grap 
duate into another. Saussure, in speakiot^ 
of a Russian travdler, says^ tbat lie wmlA 
have boldly asserted that a roasting gooia 
graduates into the spit. Thus some Uieo- 
rists have conceived that lime becomes 
flint, f>T flint graduates into lime, from the 
mere mixture of the pJEu*ticles near the line 
of their junction. The most proper and 
undoubted graduations occur only among 



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DOMAIN X. TRAHSILIBHT. 1$$ 

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 pasai 
into the real basalt of the ancients; but 
can naver become a basaltin interspersed 
with chrysolite or zeolite; and if the ha^ 
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. 



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IdQ ^oMAiv Xi TKAvmismrA 



NOME I. SIDERITE AND BASALT ♦ 

This transition may be observed in the Egyp- 
tian monuments, and is not nncommon in nature, 
trhen, in the German language, the masstte 
hornblende rock passes into grunstein; or, in 
okber words, becomes inter^rsed with small 
crystals of felspar; the common basalt of tbe 
ancientis. , 

Siderite with basalt, from Egypt 

Tbe 9ame» from Mount Sinai, 

The same, from the AIps« 



NOME n. BASALTIN AND BASALT, OR 
BASALTON. 

That is, in the German dialect. Basalt pasa- 
ing into Grun&tein. Daubuisson obseeved this 
Of Meifliier. transition, in great perfection, at Mount Mai^- 
ner, in Hessia, which rises like a colossus above 
the other heights of that country.f The mass is 
of shelly limestone; to\yards the top there are 

* The vague words with or and are used, because it cannot bo 
positively affirmed which graduates into the other. 
t Sur les basaltes de la Saxe^ p. 5Q, 



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yOMB II. BASALTni AMD BAIAUTf «t BA8ALTOV* t6f 

thin layers of sandstone and sand, followed by a 
bed of coaI> in some places not leas likan -88 
yafds in thickness. Immediately upon tins coal 
raposes a platform <<f basaltin> forming the terel 
on the snmmitywhioh is about nine miles in 
length and about three broad; The basakia 
exceeds a hundred yards in thickness. 

*' The gmnstein appears almost every wbene 
ahoFe the basalt, and in some placea has* the ap« 
peamnce of a beautiiul granite i the grains of 
siderite being black or green, laminar, and' as 
large as peas, while those of felspar ara ivhilkh. 
On the lower part of the platform, towards the 
wesft, there is a basalt in prisms ; the most black, 
the most compact, and the most homogenous, sis 
&r as can be jadged, that can well be observed* 
1 here arranged the sequence of a doaen specie 
jnens^ which presented a decrescent progresfsioo^ 
with regard to the size of the grain, from Ihe 
beautiful gmnstein to the compact basalt» of 
which I have spoken ; and to shun the obfeolion 
that the specimeia did not belong to the same 
continuous mass, I chose some in which the 
small gmined grunstein was in the midst of tba 
compact basalt; and they might be seen^ so to 
speak, melting into each other/' He then 
quotes the remarkable passage of Dolooneu in Ancient iMMtic 
these terms ; *' I have seen many statiats^ mor-* 



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tan, Moroi^lMtges, made of Mack dtonesi which 
have all the characters attributed to'the ancieiit 
basaltisi and whichhaTcpreserved that name ; and 
I can say; with positive certainty, that none of 
them is Tolcanic.'" Dolomien then proceeds to 
state that some of them are siderite, or massire 
hornblende ; but the most common are a kind of 
grajiite, in which the siderite so pr^ominates 
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 ; eape* 
cially as the felspar itself sometimes appears 
black, becatne 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 grunsteiQ. 

This passage of Basaltin into the real Banit 
of the ancients, is one of the most r^narkable 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 
' Eg3^tians did not prefer the close grained and 
uniform basaltin to their coarser basalt. Siderite 
is also found in Mount Sinai, and perhaps in the 
eastem chain between Egypt and the Red Sea; 



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WOMB MB. BM4SVIK WtfS. MflTHnTT. Mf 

hvat M the UicieDt antbofs are uMoimeM tbal 
the bwKilt^ctine frcMD Al>yttiiiia» it probak^ oo- 
CHrred under the appearance of coliunrat of tM 
snail a diameter to be eoiployed in arcbiteelttf 
or laoDttmeuts. It is to be .regretted. tbat the 
mouatains of Abyssinia have not been eaq^ed 
by any geologists as the transcendent beauty of 
the emerald-green granite alone might invite a 
research into that interesting region* 



NOME in. BASALTIN WTTH PORPHYRY. 

Basaltin being the base of porpbyry» it is nap 
tural to expect many example of this kind* 
Among others, near the village of Beaaison^ in 
the department of the Ii>iref there ocxur; after 
passing through fragments of graoite^ rocks k^ 
black trap^ surmounted by porphyfy of the tame 
base, the transilience being clear and palpab^* 
This porphyry is crowned by another porphyiy> 
c^ a brownish grey ; but in this the erystalu of 
felspar are long, and thinly scattered (a pw- 
phyron); while the others are white, and fte* 
quent. The black porphyry, and even the grey^ 
are harder Chan the trap. 

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



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1^ .. . mommm:%. «RAim.iBiiib 

kigUne^ in a fragmealidiich hat been poK»b#d« 
Tbe jMpbyry bM taken a fine polbh, while Hm 
basaltin remams doll. Tte poliib of the per* 
pbypy has brought to light litUe oryatab of 
•diori, *or stderite, whioh could scarcely he dis- 
Mwved in the Hide fragments*^ 



NOME IV. BASALTIN AND WACKEN. 

This transition has also been accurately traced 

1^ Werner bimsielC Speaking of the mountain 

werawt of Scheibenberg, he says, " I have seen there, 

account. , • . ^ » * ,i « 

m a sueoessiTe series of shades, the most perfbct 
traMitfon from clay to wacken, and from this to 
basalt (basakin) ; these three substances are the 
]|>rod'nce of the same formation ; that is to say, 
they are precipitates or sediments of the same 
di!0solation, which becoming more and more 
tfBiietf has deposited the clay, then the wacken, 
ahd lastly the basalt/'f This explanation de* 
pends upon Werner's theory, that th^ rocks 
were deposited by waters in diflferent states of agi- 
tation or of tranquillity. It may be added, that 
there i# much heat, or,, in strict terms, caloric, in 
water itself, which would otherwise be in a state 

' • Jomk. des Mines/ ir. 133. f Daub. Bis»lte8»58. 



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of ioe, ttot to mention tbe bwt def J ey od bgf 
QrystBlikation; «o that the agency of beat vmy 
he ccmcetved bb aifanitted even by tbt Nep* 
tamtam 

On the transition between Baiialtin and Ww« 
ken, the temaiks of DanbaUaoo may abo be 
adducecJU ** We havm already obseired that |mu 
salt has great i^onnexiona with the argillaoMUft 
rock called wacken. Let us reccdlebt tboM 
prisms, of which one of the extremities is a true 
basalt, while the other is an argillaceous sub- 
stance^ i^l^vbioipg t^e evid^t f/rqAvm of one 
e£fort; a circumstance which excludes every 
suspicion of aTolcanic origin. This argillaceous 
wacken cannot be considered as arising from 
an eruption of mud ; for between it and the ba- 
salt Jtbef el k a most Uariked tmnsition^ there not 
existing even a line between them.. Nor can it 
be skid that this wacken is a decoipposed )ava; 
lor at Scheibenberg, for example^ the waqken 
pas^s to common clay, which degenerates into 
sanc(, iind then into gravel; but a lava, when de- 
epmposed, '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. BasaHes, 73. 



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in 



DOVAIH X. TXANtfLIBHT. 



coinf>osition of the former* It must however in 
candour be added, that after his visit to Auvergne, 
where he was unexpectedly convinced of the v<J* 
canic nature of the products of that countiy*^ 
Daubuisson hesitated concerning even the ba- 
salts of Saxonjr, and hinted to the author that 
they might be volcanic, but, as resting on the 
summits of hills, of an antiquity altogether in^ 
conceivable. 



NOME V. WACKEN AND CLAY. 

This transition has been before described* 

NOME VL JASPER AND KERAUTE. 

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 papen in the Journal de Physique ; and here Dom. L 
ModeBaadtin. 



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voaiM Til. Alio Tin. 17t 



HTFOIVOMS f . 

Massive. 

HYPONOMB II. 

Schistose* 



NOME Vn. SLATE AND CHLORITE SLATE. 

_ ' ' ■ 

This is rather a scarce transition, the latter 

substance not being common. Slate also passes 

into mica slate; and sometimes into the massive 

substance described under the Mode Slate. 



NOME VOL FELSITE AND BASALTIN. 

Dolomieu, in his able memoir on petrosiJex or 
felsite, trap, and roche de corncj or magnesian 
basaltiri, observes that they are the chief bases of 
lavas ; and thus entered into his consideration, 
in fbrming a system of volcanic productions. 
He then speaks of the various transitions of his 
petrosilex or felsite*. 

• jQ9tfMl 4a PhTsiqii^ new tert««» toL i. p. 860. 



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'* Petrosilex, as I have already said, unites 
itself by gradual shades with all rocks, in whose 
composition some of the free earths enter,^or 
compound particles which may assist m the 
formation of the masses which it chiefly consti- 
tutes. Combined with pure quartz, in which it 
seems to dissolve, it gradually assumes all ttie 
characters of quartzose rocks ; by a progressiine 
augmentation of talcous earth, it proceeds to 
unijteitaelf to steatites and serpentines, foniuig 
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 cornt; 
fhe 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, leaire fskt greater uncertainty concern- 
ing the species in which they should be c/aawd, 
as the composition is scarcely ever the saq^ in 
all the parts of the same mass : one portion ^ha|l 
incline to trap, whil^ the other is affected t^the 
fire like petrosilex. The base of many porphy- 
ries is found in this intermediate situation; 19 
well as most of the ancient grey and green ba- 
salts which come from Egypt, when it happens 
that the fineness of thair paste no Imgertallows 



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the distinct grains of felspar and greenish horn* 
blende to be perceived^ which are still yisible in 
the gr^at^r number." 



NOME IX. GRANITE AND BASALT. 

. This sometimes occurs in the Egyptian mo« 
numents^ Jn Norway^ and other primitive 
countries^ ydns of basaltin occur in granite > 
but it is a mere coherence^ and ttiere is not the 
smallest trace of transition. 



liOMB X. GRANITE WITH GNEISS. 

This transition is one of tlie most common in 
priiftitive countries. 

Ked granite with red gneiss, from the Alps. 

Grey granite with grey gneiss^ from the 
same. 



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1^. BOMAlir X. SftAMIUaVT* 



NOME XI. GRANrrEANDORANinCPOIU 
PHYRY. 

This is also a very common rock. 

The passage from granite to granitic porpbyiy 
being one of the most remarkable and important, 
the fdlowing observations of Dolomieu will be 
Ibttnd to merit particular attention^. 

*' Daring the great coagulation, to which the 
primitive mountains owe their construction, it 
seems that there have been substances, of which 
the concurrence, or too great abundance, has 
impeded or prevented the jegular aggr^fttion, 
in giving the paste a tenacity, in some manner 
ikttening 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 
tbese earths, naturally unctuous, have prevented 
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 

* Jounal de Fliyiiqiie, neir teriei^ vol. L 1794, p. 193. 



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VOMS XI. <»A4MITft AKD OaiNITlC POBPHYRY. \^ 

the laroimir textQre of fdapar, causing i^ Io|«» 
without depriving the felspar of the faculty of 
asfunung the exterior forms of its mual crystal* 
lisation. This is perceived in those felspars* 
which constitute the large spots in green por* 
phyry, cidled serpentina antico ; and still more in 
the felspars, which mingled with green hom« 
blende form the granites called Egyptian greens. 
It frequently happens that their compact frac* 
ture no longer presents any indication of a lami- 
nar textoi-e, though they still affect the quadran- 
gular prismatic form, which belongs to their 
mode of crystallisation. 

^' Just as in the magma of mother- waters, re* 
duced to a stat^ of paste by evaporation, tHete 
are particles which, escaping from the viscidity 
of the medium in ,which they are engaged, ag* 
gr^fate and form crystals, which are found bu« 
ried in the mass: in the same manner, in these 
kin^ of magma of the great precipitation, it is 
rare that some isolated crystals are not found 
amcmg them ; and whioh have acquired so much 
more bulk and regularily, as they have had 
more facility of aggregation. They are distin«* 
guidied 6om 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; and 

VOL. II. N 



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17S 



BOMAIN X. TmANSILI£HT. 



^ which, in reality, only diflFer from granites by 
1^ this accident of aggregation*, 

<< The distinction established between granites 
and porphyries is proper for common use, it ii 
necessary for artists; nevertheless the litbolo^st 
could not admit it in a strict sense, without ex- 
posing himself to an error, which might lead him 
Onmitei. to mistake the identity of the origin of these two 
rocks, and the analogy of their composittoo* 
The celebrated naturalist (M. de Saussare), who 
has furnished us with a great and important 
truth, by proving, by a thousand excellent oIk 
servations, that the parts of granite are comiam* 
porajy, that they have all been formed in tike same 
element i and by the same cause ^ and that theprm- 
ciple of this formation is crystallisation ; but who 
has tliought he ought to make two separate 
genera of granites and porphyries, and who to 
distinguish them has said, in granite there is m 
• paste, which envelops the stony grains cftohick it 
is composed, while in porphyries, is seen a umfom 
base, or cement, in which the other stones are eth 
closed: this naturalist, I say, by the pn^resi 
of his researches, has soon himself found the in- 
sufficiency of these distinguishing characters, d 

* This can only apply to granitic poq>hynei: and tome odiq 
remarks must be pardoned, from the state of the scieocc at that 
period. 



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NOME Zl. ORANITB AVD OKANITIC POXFHTKT. I7d 

which I have long combated the precision. l*ri- - 
xnitive moniitains have often shown him, a§ well 
as myself, many rocks which have united the two 
modes of being, 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 surfaces, 
showed the texture attributed to porphyries, by 
distinct and isolated crystals, forming spots on a 
base apparently compact, and of a different 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 tha 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 eqpally on aoeoux^t of their scaly tissue that spany 
marbles, called saline, seem formed of large grains, adheriog toge- 
ther by jnxtaposition. They owe the appearance of it to a confused 
ciyttankatioD, which interlaces the spariy plates; and they lose this 
grannlar aspect, to assume that of a compact and uniform mass^ , 
when they are deprived of this commencement of regular aggre« 
gaticau" 

v9i 



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15 ififficiejitly abmidant not to be diTided by Hxc 
re^cQiinter of other small stones iviixed with i1^ 
ftQd for k? partp to form a kind of continuity of 
imi3Si in surrounding th^ other substaiicef, <^ 
which the grains ve easily isolated, may be con* 
sidered as the principal base of the rock> or as 
the ei^|ne9t which figglutinates the small stoi^ 
bodies, of a different nature, coQCurriug to th^ 
formation of the mass. Sucb are granites, wher? 
felspar alone often constitutes three-fourtbg^ 
sometimes four^fifths of the ipass ; and if an abs- 
traction of the sparry tissue is allowed, which 
4?pends on a rather mpre perfect a^gregationi 
}IQd of which it may be deprived without cbang* 
lug its nature, the granular appearance of the 
granite disappears, the felspar a^^me$tk€ aspect 
qfa cement in which the other stones are enclosed^ 
and the rock acquire the conformation of po^ 
phyry, without the transition of the one to the 
other requiring any other condition. Nature 
often, ^s if she would deqionstrate the identity of 
the two rocks, performs herself, in certain masses, 
this successive transformation of granite to por- 
phyry, by taking away and returning at inter* 
vols its laminar tissue to the felspar ; and she 
produces ma^s which, according to the exr 
pression of definitions, may be in part placed 
among granites, in part among the genus of por- 



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ptiyties. If in not even re^ttltit^! that the fetsfitcr 
should Mtir^ly Idse its texture; it is sttfflcient 
that it be ilk rery staall j^lttteft cbtlfusedly inteN 
mingled, and that it cotxtains other crystals of 
the same tiatnre, but larger and better marked, 
dmd a little distinct by theit oAont from the bas^ 
in i^htch they are dontained. Thus t]^ete i§ 
often obserml amotig the Egyptian monttment^, 
at ^ame, a rotfk whose bas6 is a itrijctni^ of fel- 
spar and black hornblende, both in small gtitlhs, 
although still very apparent} in this kind of 
granitose paste are contained tolerably regular 
large crystals of white or red felspar, which form 
spots on the base of the ro6k, and which give it 
the greater appearance of a porphyry ; as some- 
times the abundance of homblehde renders the 
paste which contains these crystals almost en- 
tirely black'*. The granites called the gtem of 
Egypt, composed of hornblende and felftpar, 
beeome similar to a porphyry, if the proportion 
of hornblende ever so little exceeds that of the 
felspar ; because then the crystals of the latter 
detach themselves from one another, and, by 
separating, form distinct white spots on the dulf 
green base of the rock. The uncertainty of the 

* Doldmieu by nc^ mefims ixceb in Ctemy compoiitkm, his sen* 
tences being very tedious and complex. His long notes, which only 
distract the ftttentioD> are here thrown into the text. 



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18^ DoMAiM iL nkjmjunt^ 

characters of this rock has always embarrassed 
systematic nomenclators, they have varied ia 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 
union oE 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 camiot 
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 



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NOMB XI. OBAKITB AMD 6EAMTIC rOKPHTlT. 189 

r^ck» they are formed by kinds of knots, or 
large kernels of a globular figure > the sub* 
stances appear, as it wefe, 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 thosci 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 quartz, or display smaller, and in 
less quantity. The argil predominates more in' 
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 first*. 

^^ More than three- fourths of the antique gra* 
nites of the monuments of Rome, are deprived 
of grains of quartz; among others, the beautiful 
reddish granite called Rosato, of which such im- 
mense coltimns 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 ^rhaps to gases ? 



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transparent fel8t>ar/ are nkistaken foe qjoarte^ in- 
asmuch as there is one direction in which tfieir 
vitiwoas fracture is exactiy like that of qaaitz ; 
but their fusibility easily distinguishes them, 
when brought to the proof of the blow«*pipe. 
pttrphyriM. ** By the inTorse of what we have said, tbe 
best characterised porphyries easily pass to the 
state of granite. It is enough that their baae 
shows a beginning of regular aggregation ; and 
there are few targe masses of red porphyry among 
the most perfect, in which spots are not observed^ 
often more than a foot in extent, where the grains 
of felspar multiply so^ as to touch each other; 
little crystals (^ black schorl are then seehin the 
midst of them, which have also profited by the 
local facility given to the aggregatioD,xor which 
perhaps has caused it by seizing the iron ; the 
presence of which, when it is free and oxyginated, 
90 &r as to assume the red colour, seenu to place 
an obstacle to the crystallisation. Thus also are 
the$e parts of granitic appearance discoloured : 
one would often believe that tiiose large grey 
gmnitose spots, which disfigure the purple oo- 
lour of the rock, proceeded from foreign sid»^ 
stances accidentally incorporated in the paste of 
tibe porphyry; if one did not discern on the 
margin of those spots, that the grains become 
gradually less distinct, and rea»«me the tissue 



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90MB XI. «1AKITB AMD OKARITtG rORPHTmT. 1S5 

of the bufe^ in which there is some appetraoce 
of a SDlntion of Oootiniiilgir, 

** There are {porphyries in which these spots, 
which difier by their coleur and texture from 
the base of the rock, are so multiplied that they 
resemble briciaB, and receive from them the epi* 
tbet of Porjidi hriciatu They appear formed of 
an infinity of similar pieces, which become 
united by a common cement. This kind of por^ 
phyry seems to me to depend on some accidents, 
which have disturbed the coagulation y which 
has been suspended and resumed at several 
times^ 

^' I mention, with equal confidence, the im* Mfmnmentior 

^ Rome, 

mense blocks of rocksof different natures, which 
decorate the city of Rome, or are found in its 
rains, as I would mention the mountains them« 
selves from which these rocks h^ve been extract* 
ed; because it itf sddom that nature herself ex« 
poses masses so large, and in such perfect pre- 
servation ^ and to obtain them thus, it has been 
neeessary to attack the heart itself of the moun* 
taias^ Columns of granite from 40 to £0 feet in 
Hevation, sarcophages hollowed in masses of 
porphyry to the extent of even 1000 cubic feet, 
present as muoh matter for observation as the face 
of a rock naturally exposed ; and they show the 
subrtances in a state of preservation which they 



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l$S DOMAIV X. TBAVflUXllT. 

cannot hare on the surface of mountains, wJiere 
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 measure to the comparisons 
that I have been able to make from the observa- 
tions furnished by the monuments bf Rome, 
with those which I collected in the mountains ; 
and I cannot too much advise all naturalists, 
who travel in Italj, to pu.rsue 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 I 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 sufiicient to take oif the kind of mask 
which covers them, and which depends on the 



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c<HOisi^ng sobstance, to behold with astonidi- 
ment that4his base judged to be uiiiform» is itself 
a stone composed of two distinct substances^ 
which do not even always require the power ol? 
the lens to be observable* Taking, for example, 
a small piece of the base of antique red por^ 
phyry, and with a blow»pipe directing the flame 
of a ti^er on it, it becomes brown by the first' 
blast of the fire ; and then are easily perceived 
the small black and white grains, intermingled 
like those of granite ; and continuing the heat- 
to 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 iS" 
fected liiem, and then their glasses ming^. 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 
th^. other, in the different masses that I have 
essayed, I have nevertheless found that it was 
the felspar which most often predominated in tl^ 
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. 



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|gg DOMAIN X. TAAimiLtBMf. 

presents in its base a superabundance of what he 
calls schorl ; that is^ the hornblende of the Ger- 
mans^ or siderite of the present work. In some 
porphyries^ called by the Roman artists Ubria- 
ganes, the felspar appears, as it were, mcdted 
into the base, so as only to present spots ct a 
different tint. It is now well known that the 
base of the porphyries is a trap, or basaltin ; and 
Dolomien has the merit of having perhaps first 
observed that it could not be a jasper, as it is 
easily fusible by the blow-pipe: but many of 
bis observations will, in the present advanced 
state of the science, be pronounced to be iti^ 
accurate* 

Granite and granitic porphyry, from Motint 
Sinai. 

The same, from the Alps. 

The same, from the Grampian mountains, in 
Scotland; 

In general the Scotish granites are veiy iite* 
gnlar,; and, in smalt fragments, often appear as 
granitels, consisting chiefly of felspar with little 
deaths or particles of mica, while the quartz is 
often rare and distant 



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jioHsa xu« 4VO XIII* 199 



NOME Xn. GNEISS AND MICA SLATE. 

Tlus is also a common tmnMtion in primitivt 
couiitries. 

Gneiss and mica slate, from the Alps, See. 



NOME Xni. STEATITE AND ASBESTOS. 

Steatite, in assuming a fibrous form, passes 
into, ^sjt^estos. *This transition is very uncom- 
mon. Saassure has described a rook of this 
kin4 J and Patrin has observed that it affords a 
reqotarkable example of the passage of one rock 
into another. 

^* This stone, which I received from M. Strove, 
is of a grey colour, sometimes inclining to jrek 
low, sometimes to green» It greatly resembles 
fksbestoss but tbe filaments are larger, softer, 
and more uqotuous to the touch ; while the 
fracture lengthwise presents long and large 
fibres, parallel among themselves, perpendicular 
to their ll>ases, and irregularly prismatic Some 
are straight, others a little bent; and they are 
sometimes three inches in length. Their lustre 
is little or none s and where it seems lively, and 



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190 ]>OMAlN Z. TRAK8IL1ENT. 

almost metallic, this eiSect is produced by a thin 
coating of talcj which covers the fibres of the 
stone, 

" The cross fracture is extremely unequal and 
splintry, with a mixture of spangles of a difier- 
ent substance. This stone is translucent on the 
edges, to the thickness of four lined, 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 ^ 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 interihediate kind be* 
tween talc, steatite, and asbestos. 

** The long fibres are intermingled with pris* 
matic columns, striated lengthwise, white, la- 
minar, very brilliant, but of which I do not 
know the nature. They are soft, translucent, 
and soluble in nitrous acid; but without effer^ 
vescence, and in length of time. They do not 
crackle under the blow-pipe; and on 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 ; the drop not exceeding the tenth part of 
a line. This stone is found at Weysler Stoude."* 

♦ Ssuss. 1915. 



I 



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NOME XIT. SRALB AMD COAL, l^l 



NOME XIV, SHALE AND COAL- 

The particles of shale sometiaies pass into 
coal, or the reverse. But this may rather be 
regarded as an adherence. Sometimes (he shale 
is marked with vegetable impressions^ which like^ 
wise pass into the poal* 

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 slate, it is 
far from being a recommendation in the kitchei^ 
or in the parlour. 

The passage of coal into bituminous shale, is 
the most interesting. The latter sometiipes 
bears the impressions of fish ; which never seem imprariaQi. 
to be observable oh 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, Schie/erthan 
o£ Werner, which generally accompanies coaI» 
and presents vegetable impressions, chiefly of 
gigantic ferns and reeds now only found betweeqi 
the tropics. This substance is commonly soft; 
but is sometimes so hard as to resemble basanite. 



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The clay-slate of that author, thanschiefer^ k 
our slate, simply so called by way of eminence, 
but a grand and primitive rocks while the other 
is understood to be of recent formation. 



QTroNoim 1. 
Uniform* 

HYP0NOM8 II. 

With impressions. 



The following transitions are upon a larger 
and more various scale ; but may be here snb* 
joined, in order to throw more ample illustration 
upon a curious and intricate topic. 

Saussure has minutely described a singular 
transition from granite to limeslate, which he 
observed not far from Courmayeur*. 

** Travelling through these pasturages, the 
eyes always fixed on the primitive chain, I saw 
below this chain beds similar to slates, and lean- 
ing against rocks of granite. As nothing in my 
mind is more interesting for theory, than the 
junction of mountains of different orders, I de- 
termined to examine this ; but a3 it was too late 



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TA«M)U9* 199 

in the day, I went to dteep at CoamnijfMr^ dis- 
tant frrai it two leag^oesy and retmntid on the 
morrow. 

^^ Quitting tha bottom oftbevaHey^ joo must 
ascend for neafly three quarters of je^n hour» to 
arrive where the schisti touch; the granite^ Thase 
schistic ^hich at a distance onty apfieared a Ain 
sur&ce> adhering against the foot of the moun- 
tain^ are a considerable mass of different layers. 
The substance which comi^oses the greater part 
of these layers is remarkabloj in that it ,brj!|kly 
effervesces with acids3 and yet very easily melts 
with the blow-pipe into a clear greesb transpajrent 
glass ; which runs and sinks on the t^be of glass 
tp which it has been fixed, . 

<* Its colour is blackish^ and its grain resem- 
bles that of a limestone^ I wished to jsee what, 
was the quantity of free absorbmt earth that this 
rock contained: I pulverised 100 gnans.^it, 
which I pounded for an hour in distilled j^Uf gar j 
this acid dissolved the half of it, and tho^e 50 
grains were found composed of 44 grains of lim^ 
and 6 of magnesia. The other 50 gnuns which 
had refused to dissolve in the vinegar, were 
placed in decoction in aqua r^s; being dis- 
solved assisted by heat, 17»47 grains of lime, 
S,25 of argil, and 1,42 of iron, were extracted 
irom it, there remained 27 grains and a half of 

VOL* II. o 



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]§4 DOMAIN 3^ >MA1I8ILIBMT. 

itidtsflOhlfe^ «ilic€ote wfOi. CJnitkig ti^ pn^ 
diMlts of '«h«B6 twa '^petM^g^^ 100 gfakift of Uifs 
schistus were foand to contain^ limo Sl,4J% 
Siieit: «7^ MftgtiMia «,«>, Argil 4,8«, Iron 
I,4?/Watf}fs ii»r/af«i tens 1^. . To«al I00,«0. 

^'Thel^n ^^tiiAft s^MMUfi are iatenniii^Iecf 
wttli laif«M^.ft t^ Mildsto«i#; b«it litAe cohe- 
reM> and 4frfkfcti tesOlv^ of Itself la a i«4iiteaaids 
found in ^antUy at Hk» Mt of ^b^se tame tajers. 
The weak ^latea^wftt^^'UiH^es thote gmins ot* 
8aiid> k of a caloareoud ^aMn^. 

« These layers wt flt1ft:tte beiit ; but tlieh' ge- 
neral pd^hikjKk, ti[ Miose' at least wrhioh are the 
tow«t» ifi ^ertioal) excepting by a few ^degreeg, 
in which they recline against Hkt moontain. 
There gmi be ^o ddubt on the positioti of the 
bed» of these flchifllif hetanse they are -exactly 
parallel • to t^e platee Of whiich they are com- 
posed.' 'ftat iHfitese layeps cHre cut here and there, 
and &V^ght angles, by clefts parallel to oae an- 
bther,* and which all bend ahfee, <!eseeB^g to 
the S. ^W. under an angle of about 50 degrees. 
Th^se clefts leare iMerrals between them ; here 
a foot/ there only a fbw hiches. When "^ey are 
t^^i^ved at a distance, 4t is impossible not to 
talbe them for divisions of the beds of the rock, 
lifo important is it in these researches to see the 
^jtct dose, and obiertre It in detail i for the in- 



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VABIOUt. 19^ 

terior stracture of the rocjc can alotie decide Be- 
tween sections w<iieh ^rofigui; right angles, whidh 
are those which denote the poMtioQ of the beds. 
I ha^e already mentioned what 1 ttiooght of the 
origin of the fUsures which thus cut the beds, 
and I fthall elsewhere refer to it again. 

*^ I have distinguished four yfety distinct shades 
in the transition of these scbisti to granites. 

*' Tfce first layers of schistus, where tome al- 
terat]<)n is observed, assume plates more wavj» 
brighter, more resembling mica ; but they have 
otherit^ise the same properties with the others. 

** The next are still more waved, plates of real 
mica are observed, and besides a mixture of 
quartz, 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 cfystallisati<m of the purest substance of 
the schistus ; for these crystals dissolve with ef- 
fervescence in acids, without leaving any percep- 
tible residue; and yet they very easily melt 
under the blow-pipe into a greenidh and trans- 
parent glass, which sinks on the point of the 
glass tube. 

'• The third shade ife a real quartz, mixed 
with a little mica, and which does not efferr 
vesce, 

o 2 



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196 DOMAIN X* T1AN8ILIENT. 

« 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 notmore than a 
foot : nevertheless, 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 which 
' form this transition. 

*< Following it round the mountain, I traced 
this junction of schisti to a considerable distance, 
by sounding every wh^re with a hanuner the 
bordering beds : I obiserved no particular difler- 
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, mn 
about 30 degrees more to the west 

" I observed also, in some places, vitridic 
effervescences which distilled, sometimes from 
the schistus^ sometimes from the granite itsdf." 



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VAAIOUi. 197 

In his interesting account of the extinct vol- 
cano of Beaulieu, in the south of France, he thus 
describes a singular stone, wl^ich was supposed 
to be transilient, or passing from limestone to 
flint. It probably rather belongs to the Diamic- 
tome -, but the remarks of Saussure lather plade 
it in this division. 

^^ The upper beds of that rock appear to me 
calcareous, compact 3 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 is 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. 
Itsfracture 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 pf 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 tp become 



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1^ DOMAIN 1^ TftAHSILlfiNT. 

fiiable or spotty; mA its edges then btepbie 
more translucent 

'« Rednoed to {Kywder» and digested in tbe 
Bitroos acid, it loses 45 hundredths of its weighty 
and the residaum, of a fine whifce» and truly tili- 
oeoQs, dissolves with effervescence in the tninteftl 
alkali. It is cold to the touch: its specific 
weight is S,d01. 

*' Under the blow-pipe it begins to orack a 
little, then it melts in boiling to a white sobria $ 
the fusibility of which expressed by a globule^ 
equal to 0^8, answers to 71 degrees <^ Wedge* 
wood's thermometer; bat the small fmgilieMs 
that have been digested in the aitrotts aoid# mce 
much more refractory, on account of their bein^ 
deprived of the cileareous earth, the principle 
of their fusibility. Globules of them caa only 
be formed equal to 0,04, corresponding with the 
14«6 degree of Wedge wood. 

" There are some small knots of flint scitteiiad 
in the interior of this stone; and its nrfaoe 
is frequently covered with pretty black denb- 
drites^ 

^* I have already observed, that natwaiirta 
have confounded the stones of this kind witJi 
petrosilex, dnd particularly with the petfasilex 
aquabilis of Wallerius. But its properties are 
too remarkable, and too different from those of 



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▼moot. tf9 

dM sMonteiy pMiwihK or konuMki of W«rftOT> 
not to fytm m sspMRtr ki mi\ 

^^ Besides, the effer?escence arising from ctl» 
GUiMUB Mtth^ scattered nnoBgtt the dcmefits, 
fu hi the sUieicalcej must he well dittinguWbeA 
iipMn that whieh avweft feon csteweow parM^ 
accidentally enidoted between the leaviss; or ia 
ihm veinB df fecandafy peteosUexy which havie a * 
reined ^r sohiatose form. 

*^ Yety near tbls» in the d^di^ ara foasd fn^ 
nenta of cianaiaBif compaet hamm^ney dkhtsr 
ka&stem of Werner^ foil of saa^faelb, and aboirt 
dl<tfi^sr^fcmws,oTttib6rciibtf ftroaobitea. Tbeaa 
are ako fheiiaeatly fbutid hi the lame atones ^ 

▼eitai of Gdinmoii flmt^f 

In another pasiagt^ § U07f oUr execttent an* 
thor describes the same sad^ftaace, and the rocks 
l¥bicfa aeeoeB|iaaied it As his work will pro« 
babljr mner be tranalatedy no apology needa be 
effered for insertii^ the paasiige^ though some* 
what long. ^OnbisronteipomAiz to Avignon^ 
be pescesrad abng the high road horiaodtal beda 
of a whitish Uasestone, which alternate wttfa 
beds of an earth of the same colour* These beds 

' • <c I tUnk lire matt refcir to tki» fBns» ihs stone knowa 9X 
Rome by the name of Selce de Madrid. Patiioi Gabinetto M'me- 
ralogico, t, i. p. iCl." 
t f im. 



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300 DOMAIN X. TftCMIILIBVT. 

of atone enckMe^ in theniiddle o£tbar. thioioimB, 
another stone in which are contained kerndt of 
flint. 

" Each of these beds, whose thkknesB varies 
from one inch to five or six, is therefore com* 
posed of three different substances: l.Whi*e 
stone; S. 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; itsiiao- 
ture presents a mixture of grains, more or lea 
small, shapeless, earthy, and without any Instie. 
It is rough to the touch, and stains the bands a 
little ; it is soft, but however less so than ckaflc 
It therefore differs. from this by being a fittfe 
more hard, and by a coarser grain. It diasobcs^ 
in acids with considerable efferyescence, and 
leav^ behind a small argillaceous sediment 

<^ The brown stone. No. 3» 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 aiigla 
and small scales are translucent ; its fracture ii 
compact with scales, being sometimes veiy 
small, sometimes pretty large. Its lustre is 
weak, a little shining; its streak is of a whitish 
grey ; its hardness rather i^ore than that of 



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▼Anouik 



miorhie, altiioag:h it jidds no spnks with stMb 
In the places where it borders OB the lAalkystcnei 
it melts into it by gradual shad^. Under the 
bioW'^pipe it is chaoged, though difficuldy^ into 
a beautiful white scoria* besprinkled with snudl 
bubbles ; the fusibility of which, expressed by a 
globule equal to OA answos to the 189 d^;ree 
of Wedgewood. 

^^ It efier^sces in the nitrous acid with many 
little bubbles; asid a small piece^ of the thick* 
ncss of a line^ after remaining in it tweaty^iofm 
hours, is fonnd to hare lost much of its hard* 
hess, especially at the surftce ; it even stains a 
little brownish^ and breaks between the fingers^ 
witiMOt however being reduced to powder. Its 
iimbility is then only 0,13, or 581 degrees of 
Wedgewood. 

.^< According to these characters, it is a kind 
of the stone which I have described in 15i4vby 
the namie o£ sHicicalce. 

<<The nodules (3) enclosed in that browB 
stcme, are <tf a fawn-colour, translucent, bardt 
their fracture perfectly concboidal, smooth in 
some parts, a little sc^y in others, having, in 
short, all the characters of true flint, or of the 
feuerstein of Werner. 

<« These nodules of flmt are scattered in the 
brown stone; yet diey more frequently occupy 



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Ihe upper ini lower ymrt of the 1M 4e tirif 
flOD^ flU l»e fovnd tbiif contignaiia^ on theooe 
iide to the wlHte ehalkj stone, and on the other 
to the flilioicalce* There ere ebo tcattared hert 
end tbeie^ in the body of the chelkj stooe^ Mmae 
mall flintty and some smaU silieiealceB, whi^h 
ate not fragmentt, hot pieced ftmned m the spots 
they occupy. 

^ These obsenrattoht and expemnenls appear 
to aae to prove that these intemediaie kindi we 
have sometimes represented as passages from one 
hind to another, or as limestones half aetaver- 
phosed into flint, are often oiJy mechanical 
mixtures of one kind with another* We her^ 
see that the calcareous earth has presenvd im 
this petrosilex all its solubility in ocids; and 
when we extract it from the mixture, what re- 
mains separated from the dissolvent, is still re- 
fractory like pore silex. 

^< I shall also draw an example firom thk SIOM 
ef the insufficiency of the externa) characters of 
a rode to determine its nature, and even only to 
decide whether it be simple or compounds In- 
dted in the silkieake, the calcareous parts are 
not combined with the siliceous, shice the nitrous 
acid extracts them with eflfervescence without 
destroying the aggregation ef the stone. They 
lire then only interposed between the siliceous 



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demente ; bow^er^ Ae wImU that, rortiltt Avmi ' 
it^ observed even with a strong magnifying glMi» 
appear»to beal>8olutely homogenous ; and ought 
conseqaently^ aooording to the rale of the litbD« 
logk:al ndmenclatufe, to ht considered as a sini'* 
]>le stone. 

** If then we owe gratitude to Mr. Werner^ for 
hmving gif en to the exterior cfaaracterf all the 
peiieiitMm of which, they were susceptible; we 
moat omit no means which may afford os lights 
upon tAe nature and composition of bodies, with 
wbieh oar sentes alone are incapable of fttmlsb- 
iagua. 

<< We frequently ftnd on the same road^ be« 
twaen Aix and Lambesc^ the same ffints en- ^ 

closed in chalky calcareous stone."* 

His account may also be subjoined of a sin- 
gular assemblage of heterogenous rocks^ which 
could not well be separated^ as the sudden tran- 
sitions form their chief curiorityi These he dis« 
covered on Mont Jovet^ between St. Vincent and u^^* Jj^ 
Verr^E, not far from the city of Aosta; being 
constant alternations of arrects or uprights dt 
steatite, basaltin, siderite, garnet rock, and oal« 
careous granitoid. 

Serpentine, with brilliant plates of green trans- 

* Sauss. 16S4. 



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0)4 OOUAin X« TJUVIl&UNT. 

parent talc, wxnetimes aadolated, at oiiiers 
fibrous or laminar. 

A lai^ rock of siderite, partly very haid, 
and yielding spaiics with steel ; partly laminar, 
and more tender. The hard part marUed with 
brown, from the decomposition of the iron. It 
is crystallised. 

A massive garnet rock, either in mass or c<mi* 
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 ; a remark 
that may be applied in many other instances^ 
and chmnists should often analjrse 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, quarts, 
and mica, alternates repeatedly at Mont Jovet 
with the other rocks; and Saussure observed 
another kind, consisting of rhomboidal calcareous 
spar of a fawn«coIour, of a pure white quartz, 
and white talc, in soft brilliant plates; a most 
beautiful and uncommon rockf. 



* Some fragments art of pure red« 
t Sauss. g65. 



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TASIOUS. 1105 

Among the transilient rocks may adso be cltss^ 
ed many which are imperfect in their structore, 
and so irregular in different portions, that they 
embarrass the scientific inquirer. 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 obserm^ 
tions may suffice. 

Great Britain and Ireland, in particular, often i^paftct and 
afibrd irregular and imperfect rocks. Even the^nSri^ 
granite of Scotland rarely presents tiie regular 
crystallisation observable in that of some other 
countries; consisting chiefly of felspar, with a 
little quartz^ and remote spang^ of mica. Dr. 
Townsoo, 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 Raglith, formed of grains of fel- 
spar and quartz, in an earthy base* 

* TowiuoD*s Tracto, p. l63» 168~ 188, kc. 



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f06 DOMAIN X. TftAtlSlLlENT. 

Malvern biUn. The mineralogy of the Makem hiils^ in Wor- 
cestershire, also presents several imperfect rocks, 
of the nature of granite, and chert, and wacken^ 
with mioa slate and schistose siderite. But this 
intelligent writer's own description will convey 
the clearest idea. He introduces it by the fet^- 
lowing observation, which indicates their proper 
place in this division: ^^ All these rocks fre- 
quently pa^x imperceptibly into each other; whence 
arise various strange mixtures^ and imperfectly 
characterised fossils/' 

^ These rocks are singularly blended together. 
Id some parts die granitoid rock, which contains 
scarce any mica, runs as it were in thick irregu- 
lar veins, or forms patches amongst the wacken 
and chert; and these likewise are similarly ei- 
twited amongst the granite, sometimes the 
one, sometimes the other, forming the principal 
mass. 

^ Ia walking over these hills, I collected the 
IbMowing specimens; none of which I iband 
any where to constitute a considerable portion 
of them, except the granitoid kind ; and this, 
tiiongh greatly varying in its nature, I found in 
considerable rocks on the summit of the ridge 
between Great Malvern and the Wrfl .House. 

" 1. Red granite, with scarce any silver mica, 
and a little hornblende* 



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VA&IOUt. 



t07 



«* t^Fat ^n&rte, 4n which a few particles of 
red felspar are imbedded. 

^ 3. Quartas and f^spar united in equal por^ 
tions^ rather in short stripes than in grains, with 
a few minute spangles of mica. The different 
eomponents being in veiy small qnantities, con- 
stiiute a body which^ at first sight, appears ho* 
iiiogenotis* 

- '* 4. Quartz and felspar, in such minute grains 
as to resemble a sand-stone. 

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

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

<^ 7- Two rtripes of the preceding granitoid 
mixture, separated by brownish mica. 

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

" 9. Red febpar, in irregular spots or blotches 
of the size of a large pea, and in smaller parti* 
cles, in greenish spatous hornblende. 



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4|Qg BOMAIH X. TlAyfllLISNT. 

*' 10, Black spatous hornblende, interspersed 
with small particles of red felspar, 

** IL Fine grained black spatous hornblende, 
interspersed with very few and very minute par- 
ticles of reddish felspar. 

*M2* A brown stone, and, to the naked eye, 
almof^t homogenous 5 but which is a mixture oi 
nearly equal portions of red felspar and black 
hornblende ; but both in very minute particles. 
^** 13. Black-^rey wacken. 

" 14* The same, with a spot of siskin green 
lapis nephriticusy or kind of jad. 

'V 15. A mixture of hornblende and the same 
lapis nephriticusj 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 chains the other 
parts of it I never examined."* 

• Tawiuon*s Tracts, p. 2l6. 



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^ '\%^^^?^OMAIN XL 



;:jTv^^ ^ 



DECOMPOSED, 



The decomposition of rocks forms a importance of 

, the iubjtct. 

striking feature m geology, as a great part 
of the productive soil, and many of the 
substances used in import^ant manufac- 
tories, may be considered as chiefly derived 
from this circumstance. Several of the 
most useful clays are reputed by some to 
be merely decompositions of felspar; the 

VOL. II- p ^ 



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2 to DOMAtV XI. OtCOMPOtBO. 

mixture of sand being a decomposition of 

LaM. quartz. Bergman found the loam near 

London^ to contain only 13 of argil ; the 

remaining 87 being a redisb O^Jgf^^JB^ 

MoQkL fine as flour. What is called 

sists chiefly of vegetable imd ftnii 
mains* The fall of leaves ia^ a 
creates a fine black mould. [. 
tn viaiiouis parta of Ikigl 
countries, the loam is of a red 
proceeds in what may be eaUed b^U or 
zones (for stratiat csai only be ntp ei; ft a|ioted 
on each other) for a great ^stmc^ Imt 
with various interraptions. This ted tiage 
can scarcely arise from the decompoted 
felspar of red primeval granite, as some 
have supposed ; for in that case the hardest 
nodules of the granite would probftbljrisCiD 
be found, as in the red saxid^toDe; Ibut 
may merely proceed from the adnuxtarp 
of red oxyd of iron, while in, other f pqts 
the black oxyd may predoqunate. Argil- 
laceous earth is found in the most primitive 
substances; and theory can fcarcelj be 
expected to determine whether the fisrtile 



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DOMAIN XX* DBCOMPOSKO* dl 

clay, which fcsins so prodigious and import* 
ant a portion of the surface of this globe, 
and furaigbes aliment to animals and ve* 
getafoles, arisen from a decomposition ef« 
foC^ted, during myriads of ages, by th« 
auperincumbent waters ; or by a mere de* 
position from the original mass ood eonsti-^ 
tution <^ the waters themselves. 
. On the decomposition of rocks, tJi« •!>- 
servations of a skilful chemist must bt 
particularly exact and interesting, for wh)ph 
reason .those of Mr. Kirwan are extracted ; 
more especially as they abound with ex- 
amples which are essential to the mature of 
the present work. It may also be pre* 
faced, that the decompoBed rocks have 
never hitherto been treated in any profess^ 
ed work of mineralogy, so that the novelty 
of the subject calls far every aid of illus* 
tration. 

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

p2 



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213 DOM AIM XI. OBCOMPOSBir. 

paration ouly of the integrant parts ; both 
often take place in the same substance. 
Causes. . « The Only causes of mere disintegratioii 
as yet known, are the vic Lii^i f fef ^^'>ftte. 
atmosphere; the absorption ftnd'>co]igelii- 
tion of water; the sudden diiafestion or 
contraction produced by tbe^ former, par- 
ticularly when extreme, catMbot but loosen 
the texture of most stony substances, and 
when aided by the absorption of water, 
strongly tend to separate them. The waiter 
thus received in their minutest rifiMl^'foeiog 
afterwards frozen, bursts theni with iacre« 
dible force, of which frequent instanoes 
occur in the northern countnes,.and in tbe 
more elevated mountains of the sdutkem, 
where the most sudden transitknis of heat 
and cold, and the highest degrees of the 
latter, frequently prevail; and hence the 
broken craggy state of thoir loftiest siuift* 
mit9*. 

*' The known external causes of decern- 



* Cranto has informed us that, in Greenland^ the rocks are often 
heard to burst with a noise like thunderv— P. 



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BOMAIHT XI. DECOMPOSBO. 219 

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 ; 
biit as to its nature and efiects, 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 wti, 
(relatively to their mass) they present a 
large sur&ce, 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 soipimr. 



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f 14 BOMATir Xi: DBCOK»Ofl«D. 

libsorbiDg oxygen, while it is thus convert- 
ed into vitriolic acid ; but moisture is also 
requisite. To this cause the decomposi- 
tion of such stones as contain pyrites is to 
be attributed; it seldonl ^acts, however, 
unless united to some metallic substance ; 
and hence its combinations vriiSti argA^ an« 
less assisted by heat, are not! sensibly de-^ 
composed, or only in a great lengdi of 
time. 
Oxyd ©f iron. « Calccs of iron, moderately oxygeoafeed^ 
are the most general cause of detomposi** 
tion, particularly when assisted :by a loose 
texture, and the other causes jc^ 4ii«ote<- 
gration ; these act by absorbing a greater 
proportion of oxygen and fixed air, but re^ 
quire also the assistance of mowtuns. - By 
this absorption they gradually' swell, and 
are disunited from the other coMtitn^A 
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 



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tnmktm xi. dboomimbd. ftlS 

oxygenated, become porple, red^ onibgBi 
and finally pale yellow ; the latter becomes 
at first blue, then purple, red, &c« 

" Iron in its perfect metallic state, or at 
least but slightly oxygenated, also decom-» 
poses water ; but if exposed to the air, it 
becomes ikrdier oxygenated ; and the com4 
pound into' which it enters gradually 
wiiiiexsj as Dr. Hig^ns observed, in irai* 
toting pouzzolana (on Cements, 124). 

^^ But stones, into whose composition 
calces > of iron highly oxygenated -seem to 
have originally entered, are very difficultly 
decomposed, as red jaspers, &c. as they 
already possess nearly as much as they can 
absorb* 

: " Manganese, when slightly 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, &c. ; it also frequently assists or pro* 
motes that effected by calces of iron. 

** Lime, from its attraction to fixed air, Lime,&c. 
and its solubility in water, must pr6mote, 



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216 OOMAIir XI. DECOMPOSfD. 

in favourable circumstances, the decom- 
position of stones, of which it forms a con- 
stituent part; to it the decomposition of 
felspars, and many zeoUtes, may in pfuft 
be attributed. i ' !I.^ .. 

" Argil, when its induration; does not ex- 
ceed 7 9 must, by the comaMoi irannHl ri- 
cissitudes of heat and |cold,' gradually be* 
come rifty, absorb, soften afid swellt and 
thus promote disintegratioA.-aiul decompo* 
sition. ; . 

^^ Bitumen is said to form tfaexement n\ 
some limestones, and probably of Kafiuox 
other species. Bowles found it so iai ra- 
rious parts of Spain, and Flnrl in Biivaria; 
and to its fusion and withering (pcobablv 
by attracting oxygen), he attributM 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 mark, 
marlites, some argillites, shales, &c. 

Mephitic air (the azote of the French) 



4i 



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noujiim xf* DBCoMPossxk SI 7 

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 proportion, 
aod those that contain animal remains, pro- 
bably most;, from this consideration we 
iBiay: derive some explanation of a very re- 
laarkablc' phenomenon, related by M. Do- 
l<UIiieu.36 Roz. 116. ^AU the houses of 
Malta are built of a fine grained limestone, limestmieof 
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 tnoulders into dust, the 
crust falls off, and other crusts are suc- 
cessively formed, until the whole stone is 



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218 JDOMAIV XI* DBOOMPfiOB. 

deistroyed. A single drop of sea water is 
sufficient to produce the germ of destruc- 
tion ; it forms a spot which gradually in-^ 
creases, and spreads like a cartes through 
the whole mass of the stone : nor does it 
stop there, but after some time> afects-all 
the neighbouring stones in the|wallJi ThA 
stones most subject to this maindbytixnitHMA 
that contain most magnesia ;; those t^kkiii 
are fine grained and of aclosete^torrernEiMrl 
most/ Short as this account ii(] it ^>p«in 
from it that the limestone 6i IfidlMt^bMi^ 
tains both calcareous earth . and magti«dai 
but most probably in a mild atvte ; ^nd 
the stone being of the looser )i;ind(. iii iCif 
the species which is known to contain most 
xnephitic air. M. Dolomieu shows, at the 
end of his tract on the Lipari Islands, that 
the atmosphere of Malta in some seasons, 
when a south wind blows, is remarkably 
fouled with mephitic air; and at other 
times, when a north wind blows, remaric« 
ably pure ; and hence; of all others, most 
fit for the generation of nitrous acid.— 
Again, sea water, besides common salt. 



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DOMAIH XI« DBGOMVOflBO. 



919 



contains a notable proportion of muriated 
magnesia, and a small proportion of selenite. 
From these data we may infer, that when 
this stone is wetted by sea water, the sele- 
nite is decomposed by 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 
mariatic 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, highly mephi- 
tised I 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 Uie 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 is 



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220 DOMAIN XT. D£COMPOtB0. 

destroyed. How the alkaline part of the 
bitre, 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 ditoapmeci kk-dtfffB 
and many stones ? I am m yeti inclined to 
think, that it is derived from. Htvt pntarefiic* 
tion of vegetable and ansniri siibatances ; 
and though nitrous acid fikiiied of .Oxygen 
and air, from putrefying substances, be 
found united not only to the absorbeat 
earths to which it is expo8€id» but. also to a 
fixed alkali; yet I should ratjmr suppose 
that the alkali is conveyed iiiito thqae eartiis 
by the putrid air, than new]yi fontf^edi ^nd 
the reason is, that tartarin, Rotwitlistaod- 
ing its fixity, is also found in soot; aod 
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 ApuHa ; yet Klaproth, in ana- 
lysing this nitrated earth, could find none: 



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DOMAIN XI. OBCOMPOtfED. j^l 

see Zimmerman's account of this native 
nitre. (36 Roy. Ill, 113, and 1 Klap.SlQ.) 
" So also when the calx of iron contain- 
ed in stones is but slightly oxygenated, it 
™ay> by reason of the close texture of the 
Atone, 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 
atmosphere. Thus iron inserted into a 
highly oxygenated solution of vitriol of 
iron, 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 
oxygen from calces of silver, antimony, &c* 



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S28 DOMAIN XL OXCOltfOSBD. 

in the beautiful experiments of Felletier, 
(12 An- Chym. 229, &c.) 

F«^;^^"« " Hence also, ferruginous stones near 
or upon the surface of the earth, beiDg 
more exposed to air and mmimt^iiWif^^ 
disruptive action (^ gro^Og Yi^fg^tsij^ 
whose roots pierce throu^ t^^ir^winviteirt 
rifls, and by swelling buryt tbwb M« oHm 
exposed and subject to. dl^OOinpOykieni 
Water carries down the le^ruginKHi^ parti* 
cles into the lower strata, mod fpriM t^ 
those illinitions and masses^i^ puiforQiitf* 
gillaceous iron ore, which Bu|Poq ^nd €rtbBi1 
have, without sufficient masom derived 
from decayed vegetables. 

^^ Basalt, when pure, s^ots^ly, remits cb* 
composition, or its surface alone bean asj 
marks of it; the argillaceofus, silioeom, Jwd 
calcareous ingredients, and part of the fer- 
ruginous, soon recombining and forming a 
hard crust, which invests and protects tbe 

wacken. remainder of the stone. But wackea is 
very eaffl^ly decomposed ; and hence ibe 
basalts or traps, into whose compoutiaD 



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wHiAwn. BusomtMim Sit 

it enters, yield easilj to the decompotio^ 
princi];^. Some gmnites* I maj. say most^ 
are in apprqpmte cvcnmstances not diffi* 
cultly decooapooed, the mica. and. fdapar 
are chiefly affected: the saaQenaybe abo 
wd of inbsft aapd?8twie8„pBrticiriaxly tfaxMe 
whose cemoit ia argiilaQeows: or ksmgmoan 
and oHtti J pozphynes andgoeiaws/^ 

From these intfxesting .obsenrations it ^JgJ^S! 
will appear, that the decoo^Misition of 
rooks is not only a cuiioos subject in itsd^ 
but of the greatest importance to the arts* 
particularly architecture and sculpture* 
Many noble edifices have soon become 
disfigured) because the archijtect. did not 
knoMT the easy decomponti<»a of the mate* 
rials. Thus at Trianon the pill^cs are al* 
ready decayed, because the aigillaceoua 
nature of the marble of Camiwn wiH not 
beat eacposuj^ in the open air, whi»e it soon 
exIoMates* At Oxford it has been obsKved 
that some. of the public buildiiigs are in-< 
juiedr because ^ builders had not studied 
the nature of the sto«ie„ wjuioh requires tv 

• Cnm'sGwIogikad Etafjm, p. 149— IM. 



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g24 *OMAtir Zf. OECOMPOSftIK 

be laid in its original position in the quarry, 
that the first compression may still exist, 
as otherwise it will imbibe the moisture, 
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 architects, as the duration 
of their works and reputation depends en- 
tirely on this branch of knowledge. It 
would appear that the ancients, who always 
mingled the useful with the ornamental, 
had particularly investigated this subject, 
even in very early times ; for the Egyptians, 
N in their eternal monuments, had already 
learned to prefer granite and porphyry, the 
two most durable substances in nature; 
and which have the additional advahtage 
that they afford no temptation for destruc- 
tion, because they cannot, like marble, 
be converted into lime : for some of the 
noblest monuments of Greece have been 
used for this purpose by the barbarous 
Turks; and a temple or statue of Diana 
has been turned into cement, for the volup- 



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pOUiM tU I^BCOMTOISB. 285 

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

It must not be forgotten that stones ap- ^^ 
pareqtly hard^ are sometimes more subject 
to decay than those of a scoter contexture. 
The pyramids of Egypt have suffered little 
degradation, though constracted with a soft 
cdlcareouis 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 coraUoid itk its structure, it was 
perhaps justly conceived that it would emit 
the moisture with the same ease as it was 
received, and hence be little subject to 

* Strabo says, that one of the pyiamids was more expensive, as 
the lover part was l>iuhivithbasah,itoin Ethiopia; a axcamstaacf 
which seems to have escaped the attention of tiaTellen, probably 
from the white crust which invests basalt. But some were covered 
with granite : see Dom. II. 

VOL. JI. H 



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ggg 6OMAIII XI. OECOMPOSEO. 

decomposition. The Conjecture, if such, 
was def tainly verified by the event. From 
this, and nunierous other es:ampleS) it may 
be inferred that the ancient architects ob« 
served, with a most scrutinising eye, the 
nature and the structure of the stone which 
they employed ; An important ciftumstance 
wliich b^ not met With due consideration 
among the tboderils. 

The sdme considerations are also of the 
greatest importance in private buildings, 
where stone is Abundant and in general re^ 
quest i and the product of any new quarry 
should be put trt several tests^ and Severely 
examined, before it be brought into n^e. 
The ejcaniple of the houses Of Mklta, above 
mentioned by Mr. Kirwdn, is a striking 
lesson of this kind; and some modem 
buildings in Scotland are morcf decayed 
than the ancient. If iron, clay, or even 
perhaps some niagnesian mixtures, be much 
intermingled, the stone is apt to become 
carious. But the magnesian rocks in ge^ 
neral are little subject to decay ; and ser- 
pentine, resisting moisture by its unctuous 



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hature^ forms some of the boldest summits 
and promontories. It was perhaps this 
consideration which induced the preference 
of ollite, or potstone, in the construction 
of the Duke of Argjle's noble mansion at 
Inverary. 

These observations c^ scarcely demand 
excuse, as being digressive, for the titihtj 
of any snli^ect is its most laudable quality : 
nisi utih est quodfadmm^ stuHa est gUmtu 
Bat to return to considerations niore iinme« 
diately <x>nnected with the nature o£ thia 
woric, ii must tiot be forgotten that the 
able illustrator of the Huttonian theory, 
has tmied tfie subject of deocnnpbied 
rooks> vhich may be said indeed ta form 
the irery ibtindation 6f that system, with 
his usual talents ; but not with that long 
and laborious discussion which was to have 
been expecti^ on a topic so important to 
his purpose. After describing the plain of 
Crau, at the mouth of the Rhone, a space 
of about 30 square leagues covered' with 
quartzose pebbles, and which Saussure ob- 
served to proceed from the decomposition 

q2 



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•bfervBtioBt. 



2glS noMkin XI. DKeanrotu^ 

of a vast stratum of puddmg-stone, which 
underlies the whole ; the intelUgent author 
thus proceeds. 

^* 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 aU over the 
world, and especially in some parts of Great 
Britain. The road to Exeter from Taun- 
ton Dean, between the latter and HonitoD, 
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- 
stone; and over the surface ofit large flints, 
in the form of gmvel, are very tibickly 
spread. There is no higher ground in the 
neighbourhood from which tliis gravel can 
be supposed to have come, nor any stream 
that can have carried it ; so that no expla- 
nation of it remains, but that it is fomied 
of the flints' contained in beds of limestone 
which are now worn away. 'The flints on 
the heath are precisely of the kind found in 



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OOMAKV XI. MCOMFOSBA, .829 

limestone; many of them are not much 
woniy and cannot have travelled far from 
the rock m which they were originally con- 
tained. It seems certain,, therefore, that 
they are the^e&m 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 calhies the greater probabiUty 
with it, that any other way of accounting 
for the fact in question, as the travelling 
of the gravel from hijgher grounds, or the 
iomiersion 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* 
menon. 

^^ 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- 



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230 JDOMAtM XU pXCOMPOfBa. 

minated over the surfkoe as thickly as ia the 
other instEDce^ and €aa be explained xmly 
OB the same supposition. 

" Again> iri the interior of England, be-* 
ginning from about Worcester and Bhrming^ 
ham, and proceeding north-east throu^ 
Warwickshire, Leicestershire, Nottingham^ 
shire, as far as the south of Yorkshire^ a 
particular species of highly indurated gra"- 
vel, formed of granulated quarte, is found 
every where in gneat abundance. Thn 
same gravel extends to the west and nortb^ 
wefet as far as A«hburn, in Derbyshire; 
and perhaps still farther to tlie north. The 
quantity of it about Binningham is very 
remarkable, as well as in many other places j 
and the phenomenon is the more surprising, 
that no rock of the ^ame 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 aiigma is explained, however, 



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1 

\ 



wbea it is pbsenredt that the basis of the 
l^hole tract just described is a refl s»nd* 
stone^ ofien containing in it a bard quartzy 
graved, perfectly similar to that which has 
just been xne&tioB^d* From the dissolu- 
tion of beds €^ thks siandstcme^ which for- 
merly coyered the present, there can be no 
doubt tfaait this guard 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 mqist have 
been worn away and decomposed, before 
such i^uantiiies of gravel as now exist in the 
soil could have been kt loose. 

^' I have said that a rock, capable of af- 
fording sudi 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-^ 
^ovG 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 



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S99I HOMAm XI. DBC0MP08BD. 

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, id its 
turn, have afforded the mateiials 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 Rigi, for instance, on the 



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DOIC4Iir HI. DBCOMTOMMI* ' 239 

dde of the lake of Lucerne, is entitely of 
podding-stone, and is 743 toises in height, 
measured from the level of the lake. Bj 
the descriptions given of it, as well as of 
othar hills of the same kind in Swisserland, 
we may, withqut 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 con- 
tain a suflicient proof that this hiU 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 
oiig^ially more extensive; and the adja- 
cent valleys and plains will serve, in some 
degree, to measure the quantity of them 
which time has destroyed.^'* 

• Pby&ir> 373. 



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f54 pouAiv m* pfApv»o«u>t 

The novelty of the topic» ia a professed 
Tvork of this natu^^ will be a sufficient 
apology for the length of these iatroductory 
observations : but it is now proper to pur* 
sue the plan proposed, by an arrangement 
of the chief decomposed rocks. 



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IIOMV X, D. MASMLTUU 83^ 



NOME L 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 
collection, has the following instances, among 
others, in the geographical series. 

aYPONOMS I. 

Basaltb. 

" 1525. Very fine splintery basalt, with half of oeniMuiy. 
decayed chrysolite disseminated, and exteriorly 
decomposed to yellowish brown day^ from Riet- 
stein. Saxony. 

" 153S. Basalt, in which the chrysdite is be* 
come very steatidcal through decay, firom the 
same place. 

" 1534. A piece of basalt with decayed chryso- 
Ike, wherein it is quite evident that the pores ori- 
^nate firom the decay of the latter, firom the same 
place. 

" 1577* A piece of basalt, mixed partly with 
small grained chrysolite, partly with felspar, which, 
as is very firequently the case in granite, is decom- 
posed to lithomarga; from Wachberg, beside 
Hartmansdorf. 



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236 l>OMAIV Zl. DBCOlfPOSID. 

" 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. Veiy 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 ao 
uniform, are smaller and larger promiscuously. 

" 1675. The same fossil, panetrated more uni* 
formly with the sulphur-yellow argillaceous maas^ 
which ^ves to the whole, in the opinion of maoj 
geologists, a volcanic appearance." 

HY70N0MB II. 

Amygdalite. f 



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1 



WOMB 1. D. BAf AI.TIV. $37 

'^ 305. Amygdaloid resemblii^ basalt, in whicb 
small groups of zeolite « occur, which in some 
places have totally lost their water of crystallisa- 
tion. 

** S06. Similar amygdaloid, out of which all 
the extraneous parts have decayed, therefore the 
whole has a perfectly porous appearance; from 
Ascherofen, in the Thuringian forest 

^' 307. A piece 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 
pumipe; from Upper Lusatia." 

As the opinion concerning the volcanic nature 
of baaaltm seems rather to g^in ground, it is not 
improbaUe that s<Nne of those substances are 
truly volcamc. 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 £urope may have be- 
come extinct As these appearances only affect 
small spots, prejudice on either Mde 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, tha^t 
pumice itself is commonly a Neptunian sub- 
stance? 



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Il3g 2)0llAIir sir »£QOMfO»ID« 



KOME n. D. PORPHYRY. 

In the same worjk^ K^rsten b^a given the fol- 
lowing examples : 

" 208. A piece of porphyry in whioh tbe fel- 
spar is indeed entirely^ but the basig oply slight* 
ly, decomposed ; from Norway. 

" 209. Porphyry in which the fekpar i$ partly 
actually decomposed, but partly appears barely 
without lustre^ tbe basis is beOi>me perfectly fri- 
able ; from the viciAity of Regeb$burg» 

" Rem. It is very frequently passed for 



tarras.'* 



The remarkable stone which compos(9s the 
Puy de DoiDe> where Pascal made hiis celebrated 
observations on tbe baroiaaeter; is a poipbyry, 
which seems to be decomposed by tolcanic h^t. 
According to the experiments of Saussure, tbe 
base is an earthy felspar, or felsite. 
jaijPKw Bat the most celebi^ated decdm{>06ed porphyry 
is the saxum metalliferUm of Baron de Boroj 
which seryes as a gangart to wxmy ri^h mines of 
gold and silver in Hungary; and ^ven to the 
noble opal, only found in that country. It is 
surprising that so many mistakes should ba?e 



metallifirum. 



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been made even by skilful mineralogists^ while 
he repeatedly informs us himself that it is a grey 
ar^laceous stoae, mistal^en by the miners for a 
sandstone, often containing crystals of felspar , 
and quartz, and sometimes schorl. But in gene- 
ral the fdspar 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; 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 metaUiferum might as well be Bomict. 
called Bonute^ in honour of thmt great mine^ 
ndc^ist 

HTPOMOMB I. 

Bomite, from various parts of Hungary. 

Mktdmnti i. "the same, with native gold in 
tfam plates aad disseminated, from the same. 

MicTonome 2. Hie same, with sylvanite^ from 
Nagyag in Transilvania. 

Micranome 3. The same, with fine dendritic 
gold, from Cremnitz in Hungary. 



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i 



^40 iK>iiAni xi; Di^onrosv* 

fiTrONOMB II. 

MicroTtome 1. The same, with noble opaf, 
from Czerwemza in Hungary. 

Micronome 2. The same, with black opal, from 
the same. 

Micronome S. The same, with milk opal, and 
many other kinds, from the same*, 

NOME in. 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^i it sometimes though rarely decompotes in 
granite, while the felspar remains entire. Mr. 
Kirwan has an article concerning earthy quartsr, 

* See TownaoQ*! Tiavdt in Honguy, for an ample aceomit of 
the opal mineSk 



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KOMB« V. AMD YI. j[4l 

in which one would expect examples of decom* 
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. KERALTTE. 

• Mr. Kirwan has observed, that when this sub^ 
stance begins to decompose it discovers the cha* 
racters both of an earth and of a stone. Kar- 
sten has the following articles. 

** S. 417* HornstonCy which in some parts is 
quite decomposed to clay, and from thence has 
acquired an earthy fracture. 

^' 493. A decomposed hornstone, which is 
there called indurated fullers' earth. From 
Mainungen." 



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 parti- 

• Min. i. 387. 
VOL. II. K 



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oolariy afiSficCed in decomposed granite} ta 
which article the reader is referred. 



HTPONOICB I* 

Felspar changed into kaolin. 

HYPONOMB II. 

Into clay. 

NOMEVn. D.GRANITE. 

The grandeur of this substance renders all its 
appearances interesting. The decomposition of 
granite may be considered on a large and on a 
small scale; in the former point of viewj the 
subject has been well illustrated by Ramond, 
Pyi€iieei. 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 wquld split into rhombs i 
but the forms cannot be called regular^ though 
the sidesj as Saussure has observed» are yeiy 
plane or flat^ intersecting, as if cut, all the 
component substances. According to Ramond, 

* Voyage an Mont Perda, p. SO, &c. It is to be regr e tted thai 
a ttyle ludicioiisly emphatic and important, sbould disfigure « work, 
otherwiae curious and intweitiog. 



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U^mm Til* O. QKAJU98* $49 

the final firagmeDt, in the maasive decwipositkiQ 
of granite» resf zi^>le8 a wedge*. One rock pt^ 
sents harder projecting veins, croMing in varioM 
directions ; while the softer parts are excavated: 
perhaps a type in miniature of the granite vein9 
observable on a larger scale, when the softer in- 
tervals may have l>een wasted, and their place, 
after many ages, supplied by schistus. 

This massive decomposition of granite often 
takes place on the summits of mountains. It is 
said that Ben Nevis, the highest moun|ain in 
Great Britain, affords interesting examples of this 
kind; but, to the disgrace of our mineralogy, 
that mountain remains without due ^camina^ 
tion. 

The high ridge of Sochondo, in Chinese Ta- 
tary, which gives source to the great rivers of 
Onon and Argoon, is said to present summits 
consisting of laige rocks, piled on each other in 
mccessive terraces. The mountains are proba^ 
bly granitic, like the celebrated Odon^Tchelan, 
m Daouria^ near the same river Onon, which 

* De Loc, Gedogiey 306, sap that granite aoqietimet decom- 
po0cs into cifcolar portions, the rhomhs having hecome spheroids. 
He 9KW pika of thev in die Giant Mountains of Silesia, which, at a 
dtiatance, xesemhled Dutch cheeses. 

In some granites the decomposed mica hecomcs chlorite ; hut it 
aecms too hold to assume thatall chlorite is decomposed mica. See 
Jtnim. d^ Mines, iv. 4S. 



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244 BOMAiM XI. t>mc0ttronp. 

presents in its opnlent bosom chrysolites, eme- 
ralds, and beryls ; and which is thns described 
by an able observer. 
odon-TcheioD. « 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 5 and it may be easily climbed on 
foot, as it is composed of granite tolerably friable, 
and which presents no precipices. This summit 
is 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. £. ; its extent in 
length being from 4 to 500 &thoms. It is upon 
the slope, which rises on the right in entering 
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 ging is on the very crest 
of the summit, at the extremity of the horse- 
shoe, it contains the beryls.'* * If this celebrated 

• Patrin, ii. 24. 



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Google 



VOKS Fir. O. OBANtTB. 24^ 

mountain had not been decoinposed> perhaps 
these precions mines 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, 
the 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. 



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d4& boMAnr XI. dbcomfoibb. 



ttTP6N0ME 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 de- 
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 hot quite so much decomposed; 
from the county of Glaz. 

HTPONOMB II. 

" 50. Granite^ in which the mica is decomposed 
into steatite, but the felspar very slightly; from. 
Siberia. 

''51, Granite with mica and felspar^ quite 4^ 
composed ; from the vicinity of Meissen. 

" 5S. Granite, with almost perfectly decom- 
posed mica, and felspar slighdy so; from Kip- 
hausen, in Thuringia. 

'^ 63. Granite with entirely decomposed mica, 
in which, on the other hand, the felspar still re- 
tains its perfect lustre; from the Altaischaa 
Mountains. 



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VMCB VUl* IX oirsiiB* 247 

/ 

** Rem. This is extremely rare, as the fekpar is 
by far the most subject to decay." 



NOME Vni. D. GNEISS. 

In this substance, as in granite, the felspar 
and the mica are chiejfly affected Xarsten gives^ 
tiie following examples : 

BYFONOlfB 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 Freyberg. 

'^ 97. Gneiss entirely decomposed, which is 
scarcely any longer distinguishable, except where 
the quartz still retains its appropriate structure; 
wkh an adhering compound of brown blende^ 
martial pyrites, and some galena; from Frey* 
berg.'' 

The last is properly a vein-stone ; and rqeks 
are generally decomposed when in contact with 
metallic ores. 



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24S DOMAIN XI. DBCOMVMBDw 



NOME IX. D. PrrCH-STONE. 

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 Africa 
and Asia, travellers have presumed that those 
prodigious extents of inert matter proceed from 
the decomposition of ranges of sandstone. This 
is perhaps the only decomposition which is de- 
structive .oC ^1 cultivation. It was natural for 
an Elector of Brandenburg, the lord of a sandy, 
region, to inquire why God had created sand ? 
While the vast and lofty chains of mountains, 
covered with perpetual snow, supply perpetual 
rivers, and perpetual fertility, to the most dis* 



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, K01IB8 XI. AND XII. 249 

tant regions ; those empires of sand present to 
human observation no symptom of utility, but, 
on the contrary, daily encroach on the fertile 
vales in their vicinity. 

Sandstone rock and sand, from the desarts of 
Africa. 

The same, from Arabia. 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 
date is particularly subject to decomposition. 



NOME Xn. D. SAUSSURITE. 

This magnesian basaltin, one of the pierres 
de come of Saussure, is not only liable to a su- 
perficial decomposition, forming a white crust; 
but, as it sometimes contains asbestos and ami- 



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%S0 POMAUf XI, DBGOMVOiSD. ^ 

anthusj may become fifty, and tha$ split by the 
l¥eather. 

Decayed Saussurite, from the Alps, 
' The same, with amianthus, from the Pyreneei. 



NOME Xm. D. MARBLE. 

Argillaceous marble, as already mentioned, is 
peculiarly subject to decomposition. * In the 
north of England^ black marble has been ob- 
served, accompanied with a soft grey substance 
called 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 decern* 
poses into dust. 



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WOMB XT* D. OOJIL* j|5| 



NOME XV. B. COAL. 



This substance, when in contact with what 
are called whin^dykes, those singular arrects or 
uprights which sotnetimes intersect whole mouii* 
taiDS, is often obsenred to be decomposed ; having 
lost its bitumen^ and wearing the appearance of 
being charred* The Neptnnists say, that the 
stone has absorbed the bitumen^ while the 
Plutonists affirm that the melted stone, ejected 
from beneath, has caused the bitumen to eya-' 
porate. 

Those imm^ise arrects are often argillaceous, 
but nMH^ generally of a basaltic nature. They 
are sometimes of prodigious extent ; one of them 
extending from Lothian through the estuary of 
the Forth into Fifesbire, a space of twelve or 
fifteen miles. It is observably that where they 
intersect the coal, the beds subside in this po« 
gition: 




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Sfi2 OOMAtV XI. D1C0UP08BD. 

ivhich 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 level 
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. E. to N. W. ; for such seems to be the 
common direction of chains of volcanoes, and 
of earthquakes ; as perhaps in the desiccatioB of 
this globe, and the contraction at the poles, mp* 
tures of different sizes took place in the shdl, 
which were afterwards filled with subterranean 
waters, and combustible materials ; while an ex- 
terior 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 work, a mere intro- 
ducJ;ion 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 ideas. 



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smcTs OF BBCOMPoaxTioir. 255 

boweveh should appear to savour of Tolcaiiumt 
let it be considered that we are on dangerous 
ground;^ for we now approach the volcsmic 
domain. ^ 



The decomposition and ruin of mountains 
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* 
serrations of the greatest of petralogists^ upon 
this singular and important topic. 

** Another fact, of which I discovered the^ Nttoreof 
solution by examining these granites close and 
attmitively, 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 section of a large layer of granite, ought 
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 
of all those that rest upon tliero, must in time 



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CMApreas them. But the external parts» harden- 
ed by contact with the air, are not susoeptibicf 
of the same compreaskm. Thaj must then se» 
parate> and thus form the exfoliations which are 
observable. 

'< This explanation acquires the highest degree 
of probability, when we see some of these large 
plates still adhering, above and below^ to tiie 
layers of which they were a part, and only se* 
parated in the middle, witere they form a kind 
of convex arch on the external side; and tbe 
identity of the substance^ as weU as the parallel 
direction of their veins with those of rocks firooD 
which they are separatedt demonstrate that they 
have formerly been united with theub'** 
Rapid. The decomposition of these prodigious worka 
of nature^ the Alps, is far more rapid and ia« 
cessant than might be supposed, increasing per- 
haps in proportion to their antiquity. The fi)l« 
lowing grand and striking observation of Saoff 
sure, will not fail to impress the reader with tfaia 
singular truth : ^' I do not exaggerate when I 
say that we did not pass an hour, without seemg 
or hearing large masses of rock precipitate tliem* 
selv^i with the sound of thunder, either from 
the sides of Mont Blanc, or the Aiguille Marbr^ 
or from the crest on which we stood.''t 

« Smiu. 174S. t i fUMf 



1 



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WffBCTt OF BBCOHVOtniOa. 955 

Of the rom of monntaiiM, one of the mortRniii orpiun, 

INT Pteoilrf 

ancient examples recorded is that which occa* 
sioned the melaDcholy fate of the town of Pitnn^ 
by the Swiss called Pleurs, in the county of 
Chiavenna ; a handsome and commercial town, 
which was averwhelmed by the fall of Mount 
Cont05 in 1618 ; when the inhabitants, in nnm* 
ber 2430^ were crushed or buried alive under the 
rains*. The manufacture of oUite, which yield* 
ed to the town a revenue of 60,000 ducats, is 
said by some to have led to this disaster ; the 
qnarries having been so improvidently conducted 
as to undermine the mountain. But other 
writen 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- 
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 omte. 
not only in all the kitchens here, but almost all 
Lombardy over, called Lavege; the stone feels 
oily and scaly, so that a scale sticks to one's 
finger that touches it, and is somewhat of the 

* Boorrit, GUciersriii. ISO. 



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256 ItOMAIH XI. ^COM»OtED« . 

natore of a slate ; there are but three mines of it 
known in thiese parts, one near Chayennes*, 
another in the Valtdine, and the third in the 
Grisons ; bat the first is much the best. They 
generally cut it in the mine round, of about a 
foot and a half diameter, and about a foot and « 
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 chisel, 
very easily draws forward the wheel out of the 
course of the water. They turn oiF first the 
outward coat of this stone, till it is exactiy 
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 the 
liquor within, that they are not insufierably hot, 
^ the bottom of this stone-pot, which is about 

* Chiavenna. 



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tvice sotbicl as a pot ofmetal, bums eatroiaie^ 
ly« It. never ^cracks, neither gives any sort of 
tMlB to the Kqtior drnt is >l>ofled m it ; but if it 
falls to the grband, it is very* brittle ; yen this is 
repaired by patching it up : ibr they j^iecetheif 
broken pots sq close^ though without aiiyce^^ 
menty by saving with iron* wire the bvoken par^ 
cab together, that in the holes which they pieree 
with the wire tbeneds not the least breach made* 
except that which the .wire both makes and fiUsj 
The passage ta this mine is very inconvenient j 
ibr.they most creep into it for near half a mile 
throvgh a rock, that is so hard that the passage 
is vot above three feet high; and so those thafe 
draw out ibe. stones, creep all along upon their 
bdly, having a (kindle ftsteaed in their forehead, 
aod^the stone laid on a sort of cushion made for 
it iQ>on their hips: the stones are commonly 
tw9/hoiidicd weighit. 

«« JBut having mentioned some falls of moun*' 
taina in those parts^, I cannot pass by the ex-* 
traordhuuy filte of the town of Pleurs, that wasr 
ftboBt a league from Chavennes, to the north ini 
tbe same bottom, but on a ground that is a little 
(none raised. The town was half the bigness of 



• BatlMr of frag^ments and afalanches; and the partial rtrin of 
[^itiavciinay m the 14th ceoturyy by the &U of a cliff : p» 7^* 

VOL. IX. S. 



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ChfTOanei; the immber ^ the idbtbitaiits wbs 
about two and tvipenty kuiidFed persons, but it 
wa$ much nMre nobly buik; for besides tiie 
great, palace of the FraDokeo, that cost some 
»iUioiis» (^re were: many other palaces that 
were baih; by several rich factors^ both of Ntifaui 
and the other parts of Italy, who liked «the 
Situation 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 all the indulgences that a vast weallh 
cOttUL furnish. By one of the palaces that was 
a 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, 
^nd yet it may compare with maqy palaces in 
Italy; and certainly house and gardens cmld 
not cost so litde as one huikdred thousand crowns* 
The voluptuousness of this place became veiy 
crying ; and Madame de Salis told me, that she 
had h^ard her mother often relate some passages 
of a protestant minister's sermons, that preacbed 
in a little churpfa, which those of that rel^un 
had there, and warned them often of the terrible 
judgments of God which were hanging over tbeir 
heads, and that he believed would suddenly 
break out upon them, Qn the 25th of August, 
1618, an inhabitant came and told them to be 



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BvnoTs or decomfositioii, flA9 

gone^ for hie saw the mountains cleaving; bnt 
he was laughed at for bis pains. He had a 
daughter, whom he persuaded to leave 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 whith 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 
person escaped* The fall of the mountain did 
so fill the channel of the river, that the first 
news those of Chavennes had of it, was by 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 o*f the Francken got 
^ome 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 

s 2, . 



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%^ BOMAIN XI. DBC0MP08B0. 

built fine houses^ and a great wealth appeared, 
of which no other visible account could be 
given but this> that they had found some of that 
treasure." 

Mr. Coxe, in his interesting description of 
Swisserlandy after a short account of this events 
adds the following observations : 

** I walked over the spot where PJeurs was 
built : parts of the ancient walls, and the ruins 
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 principal 
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. 



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1714. 



utBCTt M MO<Miroftxn(m« |9l 

and houses^ cover the spot where this unfortunate 
town was^oQce sitoated/' 

In 1714, a great part of the mountain Dia* ^^^ 
Weret 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 <)f this mountain fell in an instant, and 
covered more than a league of fertile Iand« Of 
140 huts there only remained 40; imd where 
the others stood, there is at present a bed of 
stones, about 30 yards in thickness. Four tor* 
rents were stopped, or changed their courses, 
audi now terminate in lakes. There perished 
«iD4er.the ruins of this mountain, eighteen per- 
sons, near one hundred cattle, with a great 
piiml>er of sheep, goats^ and swine. Those who 
saw this disaster, say that it happened in a mo* 
ment 3 and at the same time there rose whirling 
clouds of dust, which darkened the air like a 
sadden 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 fall, which lasted 
jfor twenty-four hours. Some pretended that fire 
.and smoke were seen i 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. 



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To this account of honeit Gr^qtier, Bt>urrit 
has added, as usual, some picturesque circuni-» 
stances. 

«« This rain hapjpened on the 2Sd oFSeptem* 
ber ; the weather was calm, the Ay dear; the 
eattle were fiie^ng peaceably under the shadow 
of these rocks; the gbats, sheep, and iaiiiba 
were plajing in the pasture. The shepherds 
and shepherdesses were diverting themseli^es 
with innocent games ; nothing happened to fore-^ 
warn them of tlieir terrible fate, whett th^ 
mountain suddenly fell, and buried under iti 
hiins shepherds, cattle, pasturages, and hvMi 
The fragments of the rocks, which extended fot 
two leslgues; the smoke, which covered 4he sky 
With thick darkness ; and the horrid noise, wh4cll 
the lieighbouring mountaitii!; increased by deep 
and repeated echoes; all seemed to announce 
total rtttn to the vicinity. The surprise, the 
terror, the lamentable outcries of men and qua«> 
firupeds, the disordered and tumultuous flight of 
bikyf^, spi^d the alanh to a distan66s and aH 
iBed from 'places tirhich -they could no longer 
kffoWyiwd Where they tcouW not hope for safety. 
•This «fetrible ruin desttoyed considerable woods, 
which served as ramparts against the avalanches 
^f sfiow, at ^r^seht so dreadful and destractive. 
The rivulets which came from the mountavi have 



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Mwnxnm o* SBcoHFesniQB. M9 

lost i\kit eoluM, dDd no lodger »ist; lo timi 
the pagttirageg are becimie dtatrts, wkicb mdjir 
remind the spectator of this snddAn rain/*^^* 

This author also infonns ns, that, at tfae.lifliA 
of the eai^thquake at li^on^ xbanjr mofihtaiififc 
were seen to shake in the Vallais, which has le* 
mained sabject to earthquakes since that period ; 
and the town of Brigue suffemd considerable da« 
mage. Bat in 1761, another moantain Ml; 
and the account of this disaster shall be given in 
the words of Saussnre; after piemising that this 
monntain was sitaated not far from Passy^ be* 
tween Sallenches and Servoa* 

*^ Near this summit was situated a tnountain; Mowfam nm 
which fell in 17^)9 with so dreadfd a noise^ and 
so thick and dark a dust, (hat many people he*- 
lieved that the world was at an end. Ithis black 
dust passed for smoke ^ eyes, distracted with 
fear, saw flames in the midst of the whirfmg 
smoke : and intelligence was received at Turifr, 
that a terrible volcano had burst forth in the 
midst of th^se lAOuntMus, so that the king sent 
a celebrated naturalist, VitaKano Donati, to Te« 
rify that report ' He came with great diligence, 
belbse the rocks had completely fallen, so that 

• Gtaootr, Olsc. de Stmt, Pkria, 1770> 4to. p. 138. 'Bcmrrit, 
ii* 9t». 



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SM BOMAIir ZU JDBaOlttOSSD. r 

be Mras witness of i part of.thftt ^v^ftt Htf 
gfcve the ting a memoir erf his ohservalions : and 
a brii^f aeoount ift cofitained in a letter to one of 
bis frietMls^ of whigh . I possess the original^ dated 
15tfa'October» 17^ 1> and of wb(ioh 8( translation 
follows: 

• ^ I left Turin on t*ie 16th July^ aiid only re- 
turned within these iew days. I was in the 
vidIey(Of Aosta ; aiid I was in hopes of beio^ in 
^^€Niice in September and October. But I was 
iMiQ^Ato turn back, and make a. tour of 250 
lealgpes in the .mountains, to observe the pre« 
tended new volcano, according to an order 
1 • * \which I received from, his majesty. I confess, 
t)a^ though: I doMbted the .truth .of the fact, 
nevertheless, hoping that I had deceived myself» 
] h!ij9*ried with extcQ^ie pleasure to observe, ao 
lextfai^rdinary ' a / phenomenon. Alfter having 
travelled fotir d^ysand two nights v^ithout halt- 
iag> I came in front of a mountain all covered 
wi^t]^ smoke; and from which wete incessantly 
detached,, by d^y and by night, large masses, of 
st^iKii With a ijioise perfectly like that of tbtfa«- 
der, or of a largie battery- of cannon ; but still 
fonder and more terrible. ; The feasants had all 
retired from the vicinity ; and did not dare to 
look at this ruin, .but at the distance of two 
miles, and even farther. All the neighbouring 



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BWBOtS OF OECOMPOSmOV. 3fi5 

fields were oorered with adurt much reaembling 
ashes; and in some spots this dust had been 
carried' by the winds to the distelnce of five 
Jteagues.' All said that they had seeir, at inter- 
vals, a /smbke which was red during the' day, 
and accompanied with flames at night. These 
observations led people to believe that it was a 
Tolcano. But I examined the pretended ashes, 
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, i)or fountainSf which 
I examined with care, present the least appear- 
ance of; sulphuric matter. Thus persuaded, I 
.enteredlinfo the smoke, dnd, though qinite 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^ lisaw that a' great 
part of the int>untain, 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 
bfeen subject to similar falls ;' at the end of which 
the large rock^ which fbll this year, had remain- 
ed without a support, and with a considerable 
projection. This rock was composed of hori- 



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265 »0M1IV XI. nBCOltfDSBOb 

sontal heia, of whi<^h the two lower were of 
filate^ or ratlier of fragile schistose stone^ and of 
little ooDsistency ; while the two heds beneath 
these were of a marUe, Kke that <tf Porto .Veiiere» 
but fall of rifts which croesed the beds. The 
fifth bed was wholly composed of slate> ia verii* 
cal leaves, entirely disunited ; and this bed form^ 
ed all the upper part of the fallen mountain. 
Upon the same level summit there were three 
lakes, of which the waters penetrated constandy 
by the fissures of the beds, separated them, and 
decomposed their supports. The snow^ which 
this year had fallen in Savoy in so great aba» 
dance as had never been seen in the memory of 
man, having increased the effort, all these wa* 
ters reunited produced the fall of three millions 
of cubic fathoips <^ rock ; a mass sufficient to 
form a large mountain. In the narrative which 
I have written of the fall of thii mountain, and 
which I sent to his miajesty, with a view of the 
mountain, I have given a more detailed account 
of the cause and effect of this ruin ; and I fere- 
told that it would cease in a short time, as has 
actually happened; so that thus I have extin- 
guished a volcano;" 

Saussure proceeds to inform us, that the ruins 
of this mountain are situated to the north-east 
of the village of Servoe. Besides the sandstooe 



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BFPKCT8 OF OBCOHPOSITIOST. 



267 



1906. 



already described*, Saussure observed rocks of 
grey marble, and fragments of slate. 

Such are some of the most remarkable exam- Ros^bei^ 
pies of this phenomenon. In 1806, the monn- 
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 Fans, 
with three plates, representing^ 1- the towa of 
Arth, the neighbouring country, and thepipfile 
of the ruin; 2, tbe sam'p 5?c^r in front, wittl the 
extent of the fall; 3. the lake and tower of 
Lawerts, with Roggiberg and Rosenbergf. 

* Dom. II. Modeouvb 

f DertUire relaiiontRi histe dhaslre, causipUr Tehcukment d^une 
pearlie du Roggiberg, et du Rasherg; de trente pages d*^tendue, 
accompagnie de irois gratn&ti, prupremttU terminier en noir, de 10 
pauces de Aaut, sur 15 de large, Chez VUlequin, march, destampes, 
grande cour du Tribunai, No. 20^ ^Jr. 

La premiere represente le heau bourg d'Arih, les campagnes qui 
tajifoisineni, e/. le prqfil du Feboulemeni: La teconde, Vimmense 
eaktfcdftiie, W triite toMettHi tturtepartie des ht^iant, de ia ^afUe 
fArtk^ ei tebouiemeni ^ deface. La iroieieme^ Uiaeei la low de 
Lawerts, le Roggiberg, et le Rosberg. 



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DOMAIN XII. 

VOLCANIC. 



Volca»oct 



The volcanic rocks may be said, with the 
Gennan mineralogists, to be of the most 
modem foraiation, as every new eruption 
of about one hundred and fifty volcanoes 
scattered over the face of the glol:](p, must 
produce new rocks of this description. 
That there are also volcanoes at the bottom 



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SOMAtll XU. VOLCANIC. 269 

of the sea, we know, from the ejection of 

new islands in the seas of Greece; and in 
the Atlantic near Iceland^ and the Azores. 
It niaj therefore be considered as a most 
rational conclnsion, that, as the ocean oc- 
cupies two-thirds of this globe, numerous 
volcanoes may exist at such depths, that 
their effects are wholly unperceivable- 
Dolomieu seems to have demonstrated that Depth of ftiA 
the matter, which supplies the prodigbus 
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- 



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270 DOUAIH XXI. VOtOAIIIO. 

bent masses of granite^ itself r^arded as 
the fundamental rock. 
Candour As it is foreign to the nature of this work 
to examine with much attention the the- 
ories 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 
thci 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 complete 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, 
for 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. 
Manyextioet Whcu wc cousidcr thc great number of 



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Yodcdiioef tbat are still actiTe on that third 
part of our planet which consists of land, 
is it not most rational to suppose that many 
may have beeoone extinct? Strabo informs 
us, that VesuYius had been a volcano at a 
remote period ; while its first eruption is 
commonly ascribed to the reign of Titus, 
near a century after the time of that author*. 
The volcanoes of Auvergne seem to have 
been relumed for a short peiiod, in the 
time of Sidonius ApoUinaris, whose cul^ 
mina can scarcely be applied eicept to the 
summits of mountains ; for the tops of 

* Lib. y. This remarkable passage may be thus translated: 

'* Here arises the mountain of Vesuviusy inhabited through all ito 
delirioua Adds, tke rammit alote excepted, which spfdads into a 
barren plain» displaying ashes ajnl deep carems fiuaned of burnt 
rock^ as the colour indicates, and abrasions by fire ; whence it may 
be co pj ectored ibal dkis flaountain was formerly in a state of eflk- 
iption and prtseatod fic^ craters^ iwhicK hecaiae extinguished 
when the materials were exhausted.** He proceeds to state, that 
Ale fiddi near Etna were equally fertile. The streeU of I^ercu* 
hvDeiim were ptv«d with lanu 

See also^ Strabo, lib. i. p. 158. edit Siebenkees, for a volcano^ 
locm extbct, near Methone, which ejected a hill near a mile in 
h^gJU, and rocks like tof^t^. 

Pindar deacribes Etna, which is unmentioned by Homer, a proof 
that his geographical knowledge did not extend as far as Sicily^, and 
duft the received interpitutioos are false. 



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272 DOMAIN XII. VOLCAHXC' 

boiises would be foreign to his emphaikiG 
and alarming description, i^uyergne alone 
has indeed convinced every Neptunist, who 
has visited that interesting countrj^ that 
volcanoes may become extinct ; and may, 
perhaps, again surprise the unbeliever witli 
an unexpected appearance. The wonder- 
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 Une of 
direction of the other volcanoes in that 
country ; whence it has been argued, that 
there is a chasm, at an amazing depth, 
filled with subterranean water and combus- 
tible materials. For the i^merican 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 observed from dig^g 
wells in the north of Italy, neat 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 oceaD> and influenced hy sea-water instead of subterranean 
lakes.' 



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mOUAtk XIU TOLOANIC f^ 

tt a certain crust, the water gushes 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 
to imagine that the immense mass which 
forms the nucleus, and which from its 
gravity would appear to be iron, presents 
a oniforra surface ; but may, on the con- 
trarjr, bear fissures deeper than the ocean, 
and asperities or precipices higher than 
mountains. Hence the grand observation 
of Saussure, his refaulements^^ may be con- 
stroed into a subsidence of the beds at one 
extremity, owing to irregularities on the 
8ur&ce of the nucleus, and which bf course 
devated them at the other extremity ; while 
the secondary rocks, the level or horizontal 
of Werner, finding the asperities already 

* " Exjuiner ea g^o^nl li let qooches presentent des. indices de 
•ooleftments, on de refoulements Tiolents, qui aient chang^ leur 
sttuMion primittre ; on ii» ^ contraire tdus^ et les redressementt 
^oka^ dci ooochei, peu^rcot t'expUquer par de limplet affiuMemenU*** 
f S314. 

VOL. II. T 



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(74 MMi4lir SIL TMMVIC. 

fitted^ of coune retein thoir mgulMr torm^ 
Ation. 

But if, with Dolomieu, we eonoeive that 
this planet qaIj presents a sheU sfNPead 
0vev a fluid c^eotre, it would be difficult to 
explain why this central lava should oulj 
burst forth in particular spots and direo- 
tiona ; for it might equally appear in every 
pcNTtioQ of the ^be. Theories, wfaidi 
eoly afford sublime speculatioiia on the 
mst varieties of nature^ asd the infinite 
power of the ineflable Creator, cannot be 
greatly blamed, even when they do tyot 
lead to tnoontestibleooiieli]ttions; and it is 
hoped that an infiuence arising from the 
pieoeding considenttions may be hajmrded ; 
namely, that vokanoes owe their origin tD 
fissures, more or less extensire, in the veiy 
nucleus of our planet; and that these fis- 
suies alwaya remaining, <he causes of erup- 
tion may be withdrawn or renewed. This 
theory might reconcile most of Ihe doc* 
trines on the subject, except the puerile 
ideas of those Wemerians who have never 
visited volcanic countries, and who impute 



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Bou^HM Xiu iro&Mua f7f 

these wonderfiil 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 cFer struck 
the most attentive and rigkl 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 n^ 
Beet on the daily cireumvoiution of this 
fdanet, it is impossible to fiad a greater 
miracle. In complicated scenes there moist 
be oomplicated causes ; but does mt tiatt 
gratid exhibition of volcanoes adae fima 
'aatuiW gunpowder?* 

* The oommoa sabterranMn noise of Cotopacsi, magr be heard at 
a distance of the space between Vesuvius and Dijon, in Burgundy^ 
tcBnrtwgtoHtimboMt; jilBaagacr^p^ itfi» icagiMMS^aiaii 
aame Tolciao has thiown stoues, of 8 or |) fiset in diaineav, so 4^ 
distance of 9 miles. 

W«mtt«daiiiBiMltt»lumiinDed<the4n«t4irtMitlfcii ofa^pot- 
caaoj and his pseudo-vokaiMes ane much beneath even that 9»m^ 
haying scarcely a &int resemblance of a volcano. 

AtxxffdiBg to Brecham, ii.^33» one eriqfti<m of fitna covered ft 
space of iBOfc^iaa KH leafinqiA ebeiMW wMi a bed «f vokanipvari 
IS feet thick. 

T 8 



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1176 



ttOMAIN XII. ¥OtCAiri«l 



The existence of such chasms being once 
admitted, it would be easy to account why 
basalt always appears in volcanic coun- 
tries ; since, even on the supposition of the 
French mineralogists, particularly Patrin, 
these chasms must have supplied volcanic 
materials, under the primeval waters, or 
what may be called a state of chaos ; for 
Patrin supposes that basaltin, compact or 
columnar, but especially the latter, may 
be the produce of submarine volcanoes, 
the matter being suddenly 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 German 
mountains was a volcanic remain of incon- 
ceivable antiquity. Iteuss also concluded 
Btfdtie that the basaltic summits of Bohenfia were 
jonly fragments of a mass, which had once 
clothed a prodigious territory. In like 
planner, caps of mountains sometimes pie*> 
sent masses of sandstone, or limestone, 



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90MA1M XII. TOLCAVIC. t7| 

while none exist in the adjacent countrji 
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 
efibrts 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 been 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 
foe nothing, in the eternity of Him, with 



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tTi noukin XII. voLCAMxe. 

whom a thousand ages are but as one in- 
stant. 
Effect! of In general, the effect of fire only is con-* 
sidered in volcanoes ; but the curious rol- 
cano of mud in Sicily, and the muddy 
Eruptions of the Andes, should excite more 
attention to the agency of water. If wc 
conceive the volcanic chasms, containing, 
as already mentioned, reservoirs of water, 
as well as of inflammable substances, to 
be in the nucleus of the globe ; and that 
ttucleus to consist of iron, mingled at least 
superficially with its usual attendant si lex, 
the ferruginous nature of lava am easily be 
explained, as arising from an abrasion of 
ibe nucleus by the water. For, passing 
Che minuter appearances^ which only excite 
enriosity, and are exceptions, not rules; 
inrnvodoia. all lavas may be said to consist of iron and 
silex J the most commcm being the black, 
of melted siderite; while the others, i^ a 
grey colour, have a base of silex in the 
T^itpw. fatm of felsite. But felspar is a name of 
far too general acceptatioii ; and may pro^ 
bablyi in the pfogress of mineralogy, be 



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diirided ioto six or more denomiiiatioiis, to 
be detennined by ftitiire analyses : for its 
extent and importance are prodigious, con* 
atituting two<>thirds of granitie mountainsi 
and appearing in many other forms, which 
seem to indicate a substantial difference in 
the siliceous rocks^ now included under the 
vague name of felspar. 

These introductory obsenraticHiB hare !«««. 
thus conducted us to the more immediate 
obfcct of this work : the consideration of 
the lavas themselves. 

The existence of compact lava, forms <^<«pm^^^ 
oae of the most curious questions between 
the Yolcaiusts and the Neptunists. In 
strict impartiality, the observations of Mn 
Kirwan, the chief defender of the Nep- 
tunian system, shall be admitted at full 
length, more especially as they may lead 
to very important observations. 

^ By compact lava, volcanic writers de« '•'iSj^^ 
note an earthy substance, which, after 
having been fused, but not vitrified, be* 
4M)mes, on cooling, compact, close^ and 
tolid. 



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f9Q mouAin XIX. vo&oAm«» 

** Whether this degree of solidity is 
as totally to exclude that evidently pocoBS 
and cavernous structure, which cellular 
lava presents, is not perfectly agreed 
upon. 

^ Those who are guided by observafciott 
on moderp and undisputed volcanic tor** 
rents, allow that no lava absolutely conif^ 
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 whicb, 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,' 3 Bergm.. p. SOL 
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 cf 
common marble slabs, they never exhibit 
an uninterrupted surface. This last inen* 
tioned philosopher, indeed, having unfor« 
tunately wished to comprehend, in his de* 
finition of compact lava, stony masseSf not 



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BCniAXV XIT. TOLCAKMU fSt 

fiumd in modem and undisputed beds of 
laTEy but in supposed ancient currents, 
found himself much embarrassed : ^ there 
ift^^ says he, ^ such uncertainty in the cha«t 
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 iq many instances mis« 
led by Dolomieu, yet acknowledges that 
lava, so compact as to be totally destitute 
o£ pores, is not to be found. Litholog. 
Vesuv. p. 85^-. 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 thq 
porous being found of modem date:};. 
Galeani, in his catalogue of the lavas of 
yeauviusy drawn up in 1772, hardly me{i« 

• Isles Ponw, 171. 

t (It is 157 ; but not expK88ly.^P.) 

I Ponce0, 174. 



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XIL TftltlAlfflfr 



tioAf any eompact Iavfts« Grioeiu, in 
ciltalogue, entirely omits this di$tinctim ; 
and M. Doloanieu acknowledges that Dok 
a single specimen of compact lava is to be 
found in the cabinet of Prince Biscan. 

^ Tbose, on the other hand, who, guided 
by system, bestow the name of lava on 
stony masses which they suppose to have 
anciently flowed, either from real still sab- 
sisting, or imaginary ancient extinctt v6^ 
eanoesy find eompact lava entirely destitute 
of pores, very scarce indeed in the sup* 
posed currents fhxn modem, but in greai 
plenty in those which they ascribe to their 
fictitious volcanoes now extinct, as well as 
m the very bowels of those volcanoes. 

^ Gioeni after telling us, from Dolomieu^ 
that c<»npact lava occupies the centre oi 
&e beds of lava, and porous lava the uppes 
part, acknowledges that this gradation sdU 
^m takes place : • few, however,' says he^ 
^ are the visible currents of lava on Vesu- 
vius, in which we meet this gradation/ It 
seems lie should rather have said, none; 
for, some lines after, he tells tts> ^ that mo- 



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dem Toicanoes have lost the power of proN 

ducing anj^/ The detached masses that 

paas for compact lava, he acknoi^ledges to 

have been ejected in their 8<did fcmn^ bjr 

the explosive power of the volcano; and 

consequently they aore not real lavas, but 

rather natoral stones, torn from the sidet 

of the mountain^. M. Dolomieu tdls ns^ 

that compact lavas are stones, which, aftei 

having been melted, reassume their natural 

atate and appearance, without an j change . 

in their external or internal properties, or 

scarce anj change:}:; and that some are 

perfectly compact (that is, destitute dT. 

pores) ; namely, those that are buried un« 

der, not other lavas, but under an entire 

and immense volcanp^; he therefore gives 

up the idea of finding these, not otdyin 

tlie beds of modern, but even in those of 

extinct ancient Tolcanoes. Hence he tdls 

ps, that they are mucii more common in 



f IilM.Taa««f.4r- 

t Ibid. 6U 

I Dei piodotti Tdcan. p. l6s. Pdnocs, 170, 5eo« 

) Ibid. ]79« 



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fS4 BOMAIV Xir. « TOLCAVie* 

extinct rokanoes ; aiid that in Etna they 
do not constitute the one thousandth part 
of the whole ; whereas, in Vivarois and 
Auvergne, they form whole mountaios. 
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 thesuperincumbent ^veight^ 
are more compact than common porous 
lava, and these, comparatively to the for-- 
mer, may be called compact ; but scarcely 
more than a few square 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 contrafy, the remarks of another N^ituniit^ Dm* 
buisson, in Dom. I.— P.) 



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BOM Am Xll. VO&CAVUS; 



^ Their fracture, earthy, or fine splii^ 
tery, more rarely foliated, and presents 
small internal pores, if of sufficient size^ 
Iq some part of their substance. 

^^ Hardness, from 7 to 9* Specific gr»< 
vity, 2,75 to 3,88. 

^* Much circumspection is requisite, in 
framing a description of compact lava, from 
a view (^ the specimens brought to usfirom. 
Yolcanic 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 lavas, we 
should attend to the following circum^ 
stances: 

** 1st. That the heat of most volcanoes 
(I exclude those that for the most part 
produce only vitrified substances) seldom 
reaches 100 degrees of Wedgewood ; 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 



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HI it tfaej did not attain diat degree; 90 or 
06 degrees maj then be aisumed as tiie 
average heat of meet voicanoes* 

^^ 2d. In this heat, many stones of the 
argillaceous genus, as traps, faoraiilendesy 
and argillites, undergo a change; for they 
alter their colour, become porous, assume 
a poroelam grain, and consequently beg^ 
to vitrify, as I have found on repeated 
trials ; but they never flow in this heat,n<» 
ocmsequ^itlyfonnalava; bntlMtameniviil 
flow in this heat, and even in one nrach 
inferior, and be deoomposed. If, there* 
fore, the argillaceous stones be mixed wkh^ 
uid drenched in bitumen, they will be 
softened by it, and flow with it ; and wbeie 
the air, erupting both from them and the 
decomposing bitumen, has most liberty to 
escape, it will tumify, burst throegjh the 
liquid mass, and form cellular lava; bnt 
where it is more compressed, less of it will 
be disengaged, and the lava will be com<* 
pact, and resemUe in some degree ^ on- 
ginal stone of which it is formed. 

^ 3d. Stones of the si&)eous gnus cm* 



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ifergo no change ia this be$A^ not evea 
schoris or fehpan; and faeace, ^lough m^ 
SQoerBed in die fiery torrent, they cannot 
ifith proprtet J be called lavas ; as they aie 
not eren softened by (he mixtive of faicvh 
meoy as stones of the argillaceous gettOB 
«je. 

^ Between silioeoos and argiUaoeous 
stones there are many gradations, and v^ 
liouf mixturea, which must occasion cov* 
responding varieties in die effects whidi 
heat, and varioos other ciimimstaoces, may 
produce* It is sufficient here to artablisli 
die principles on which most of them may 
be explained. Ck>mpact iaras abound la 
faetcBogenous substances, which have eitbcr 
not been Ansed, or only partially iused, or 
fcorched, or decomposed by heat, as fel- 
apar, isdiorls, garnets, zeolites, &c. Every 
volcano has aome that are peculiar to it* 
Thus the hnras €i Vesuvius abound in thai 
called wHite garnet, and which I call V^ 
suvian ; thoee of Etna abound in fdspa?!, 
&c« 

^ Henoe we must exdude ft»m the nak 



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'%8$' I90I14DI XIU TOLCAIflC. 

.of laVaSy all stoDes wbich do not appear, 
-either from their external characters or 
local circumstances, ever to have been 
softened by heat; and consequently all 
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. Thus M. Dolomieii, Lipari 85, 
xeckoDS among volcanic stones one, in the 
interior of which he distinctly perceived a 
leaf of sea-weed. Few indeed are the 
stones contained in his catalogue, whidi 
can be deemed really volcanic : and p. 70, 
of the same treatise, he tells us, that the 
lava which burst from the sides of Etna, in 
t669» had for its basis a granite, no way 
altered ; but when he expressly treats of 
the products of Etna, he tells us, L'Etna 
.paroit n' avoir jamais traiti le 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 
liad an opportunity of viewing volcanic 



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to detect them ; a libertgr v4upb» \ am pfurr, 
suaded, his candour and love of truth will 
readily induce him to excuse. 
' ^ Ail reai ^yaa, «xx^ept those of tW T»-. 
teeoNHL kind^ aflbot tiie Magnetic aeedli^ 
isokystha iron the^ contaia. be nmdn oxffr. 
gffanaterf, aa ifc <]fitai ab ysi tiboao of a md 
eoikrai ; bat evan theae asa fnsqueatly, m^ 
mtttic^ by K^on of the ackoida (mJtiodieA 
m them. 

^The <oam|mieoi lagnAimtB of farat 
$po miooa, laccondmg to >^iiaiture o£ the 
eng^Hal atones, find 4he acGidcnto thqy 
meet with in Ae liqai^ stfite. M. Diet* 
lo^iien found ^em to coiitaiia ^m 4Q to 
60 per cent 4)f silex, ftom l^toS of majh 
IM«t» fratn ;5 te 1 of Bme, and ^ntm 6 to 
ftfiofiron. iBpaoes, 184.^^ 

These reflections are certainly cogent, 
and vorfliy of the sagacjous audiof, who 
lias iBBdewd gnat slices tfi Ae «cjj^w3g : 



J VOL. II. U 



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^90 DOMAIN XIL VOLCANIC. 

nor must we, in the modern spirit of in- 
gratitude, nor even of 

Th* unwilling gratitude of base mankind, 

ibrget the state of mineralogy at the time 
he wrote, because superior illuminalion 
has since been thrown on many topics. 

J^. On the other side, the works of Dolotnieu 
on the Lipari Islands, on those called 
Ponces, near the Gulf of Naples, and on 

ooioi^ the volcanic productions of Etna, were 
written before he had attained much expe- 
rience in lithology. This truth lamentably 
appears from the latter production, where 
two or three passages demonstrate that he 
did not even know what granite is*; yet 
we are told thlit exact nomenclature, and 
the predse knowledge of particular stones, 
are not necessary in geology ; which is as 



imccimte. 



; * In p. SOI 9 he tells us that the 2r<|itf of granite^ godsIsIs of i 
sive felspar : and p. 257, he mistook a mixture of schorl, felspar, 
and chrysolite, fi>r A granite. Bqual errors may be ^yoad in many 
books of geology ; a study which totally depends on a previous 
acquaintance with petralogy and lithology. Dolomieo was a miU- 
tayy man, who at an advanced age entered on this difficult study. 



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DOMAIN XII. VOLCANIC. fiQl 

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 labprions study, and eren the most 
nice discrimination of Uthologic character^ 
istics, is indispensable ; otherwise the key* 
stone iliay 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 tedjoms, prolix, and 
ill-digested, like all his writings, are the 
best and most scieqtific of his prodifctions. 
But, on the other hand, our celebrated ' 
.minenilpgist is certainly mistaken, when he 
asserts that siliceous s^or^ undergo np 
changp in tilie heat of volcanoes ; for the 
white or giey l^yas, with a base of felspar, 
ai:e ^mong t^e 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 the mottled or 

u 2 



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£9^' DOMAlH ZII. TOLCAMld.' 

dotted ^ppearancfe of thk Mh is such SS 
tfeVer occurs in any natdral rofck.' THe 
qn£^ntity of ffotasJi recently distebi^eted iri 
fels{j^f, sufficifihiiy ifcfcodtits ft)t itsfiiiiWJL: 
tity. Nor, so f& ks Uife J)fenlsal bf fac^t 
#otki bn ili^ ^'nbject ckh c^dufei to «il 
Opitilbii, a ihh jib'wct bf vblttlWi; heki to 
be coinptited tto^ k fb# bk»iii|iiB ; wHil^ 
ii i^ sbmetimb^, bn ille bbhh^ij^', deMbdi 
krdblb to be verjr iiiterisfc. 
co»^i.» it is triliy ^inguldr that, iti ihb ivdh of i 
scleBce so much ati^^hfcfed hhidi dife tiiti^ 
of t)bloiiiieu» spbclmeiis of febtajSact Ikt4 
lib not abbuii'd in bvei^ babinet; khd tHdt 
' Ihe subject his liot been cb!lil)lefel5r in^fc- 
tigatied; but attention hM bbeii diVeHeii 
to cry^tallogrtiptiy; whi'di hiajr be caltteA 
the entoiiiology 6f the Itefefeteei \^ttfe tfife 
Oddest bbjbcti bf m^ift 'krt ik^ec^SSdi. 
hbXoihiet |>ositiveljr a)lb4s t^at wMt <ft 
calls i^e baMtic ikA^m; xUm^VA^fi^^ 
tie bn ttie easWm 'sidfe tX Etii^ fefe fc5ftt 
i)bsed'bf ilavA, "ofWtMiWb^&t'^im' 
'|)^bt mbiteld £U« not eiWpt ^kom si:A^% 
%^tle tt)und {ibTe^, easily ViteiV^i'alAb Witb 



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DOMAIN XII. VOLCANIC. 



q^pofjtlje mgst cofnp^ct si:^bstaiices ^n ^a^ 

J^UupJ^^Qel]^^ fiven in 

Jtjic pi^f^/i^l^j^ces, ,858 ^Ms, the mai^l^^ 

«?^??i«»- l?H^tf?^t %^fl,^^^^^ 

wT^:.bteai(j^l fc^fms pf^ba^^^ltic column? 
.j^ye, .flp a ,^r^t ^yev^j^w, been compare^ 
^with Ijjp^fi^ifl^ ^^J???g ^PP the desicca^ 
tiop of . stajch, ^nd some argillaceous sub- 
^t^Q^. ]3i^t,|:^e co^pari^on is in fact <^f 
the^naost capfle^s kind, and arises frpm ^ 
djsji^nt .resemblance, ^8 if a trunk of a tr^ 
^^ere compar^ with a/Coriathi^n colpi^n. 
^e.^ccupte ejre of Pictet has observed, 
^ap4 J he .h^ ^ engraved . a most distinctivje 
9l|^^cteri9tic pf the columns pf the Giaqts 
causey, unobserved by all writers on the 
subject; which is, that the joints of the 
columns are not only inserted in each other 

• Etna, p. 192. 



»*J2 



Bafldticco> 

Inimis com- 

pftredwitb 

hfi. 



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H-^^Mi^i 



294 DOMAIN XII. VOLCANIC. 

by hemispherical protubierances and con- 
cavities, but that the comers of one joint 
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 Paiis^ 
and has engraved in his mineralogy, speci- 
mens of Siberian emerald, with similar pro- 
tuberances and concavities; the former 
sometimes admitting of being detached 
when it assumes the form of an irregular 
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 frac- 
tures are covered with a fluid of an unctu- 
ous appearance, and penetrating smell, 
which evaporated quicker than a drop of 
. ether :''-f- but exposure to the air for a few 

• Da Costa, howeverj had observed and engraved the same ap- 
pearances, in 1757. See his Fossils, p. 256, and the plate. 

t Min. ii. 33. From this and other circumstances, detailed in 
various parts of his work, Patrin argues for a kind of mineral life. 
He might have rather said that God fills all space. 

Mens agttat molem> et magno se corpore miscet. 



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BOM AIM XII. VCULCAWIC. • g^ 

hours, rendered them quite hard. It might 
hence appear, that to carry the chemical 
analysis of mineral substances to the great- 
est perfection, means should be contrived 
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. This simple attention 
might perhaps lead to very curious and 
important discoveries; which might gra- 
dually conduct us to rival nature herself in 
the combination of the most precious mi-- 
nerals. 

To return, as the crystallisation of eme- 
ralds has never been denied, so it would 
appear that the yet more curious and re- 
fined articulations of basaltin cannot be 
ascribed to any other cause. The colunms 
of sandstone, and other substances, and it 
is suspected even the columnar, lava of 
Etna and other volcanoes, cannot be com- 
pared with this consummate, and, so to 
speak, artificial architecture ; for nature is 
the art of God- A prejudiced eye would 
■find identity; but if no such fprnas be 



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A||5 ii«rAiii*Kii. *Y«iontie. 

observdble iittfae coiunmar isras, oratiood] 
^argument would 'arise that the baaaltxceci- 
himDsr hare a' differeht biigifi. Sueh^is' the 
^nalhile of lithblogy, tfaat'a ^eiry ' miiluie dtf- 
ferebce semetimds c<te0tilitities^'a*mde'dis- 
tinctioiY ; anad WertiCF'S sjatetai cf efttienridtl 
charaeters • rtets - bn^ Hide « tints* and-'sliadGSy 
ior Airliieh ' his saga^^ily fband^^ expr^sflioBs; 
^xHnle'Bsany of tiiem kcre beem-^knovn be- 
fore by experienced minen/wfao ielt'tmd 
^knew'wiiat'they coratd not'ctpress; as-u 
sliepberd'caitoot imilart'the^ksidirledge'^ 
which he can discern any one sheep atsra^g 
a thdosannl^ a triTialcurciBnstaiulermpas- 
tural Oduntries. 
c^rvnjof The final ofHnion of Dcdetaiiba^ in^ wliic^ 
he is? joined by Spallanzani, ^ho vwtdd tlfee 
rolcdnic regions of ^ Italy with • grtat< eare, 
tboogh" not perhaps w<]th asufficibat ex^ 
rienee in h^olc^y^^t^as that balsidtin may 
be produced either^in the hmtkidrwayry dr 
by volcamc fire. In suhnrarine! volchnoes, 
if weligten to the French tnineralogists^ it 
might be ejected by heat, and ctystalltiN^ 
in a more compact ilnd beduti&il &nn 



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AMt«lIc «T«*«MI«C. 



^tlmn it 4Msum)88 wkea it only eauteis <lJia 
.eonfiaes vof t the i sea. It aWajs «eem )to 
'faftvfe anotbtt - sii^laxity, wfakh muat ^not 
\he ifoigotten, munelj, :an arid land tcfaead 
-appcaj^tnce, laddiqg it with rthe >stoiiQB 
calted «by • the iltiiiam piWn (tmniii ^vdufe 
.other substenees iadeseiibaMj heloog ip 
^mdiat is) called thb&livk^g roek. 

In.t^«qpisik>o,itlierafore»:^f liieigreataat 
Bnneralegistg^ twe are only aMthoiaaed to 
consider as .covfmct >la\ias > those *(v^iidi 
•have Tevy small ipQ>res; for vdksasiclba- 
-«&ltin, though admitted by^DokimieikiaMl 
SpaUaaaaoi, is: exposed to all the fteQqp«tts 
of Nqstune and his followers. Maiees and 
«)hinins of -baaadtisi, ifaeought 7rom vwcU 
known lavas of whatever antiquity, would 
alone ioim a barrio against their attacks. 
lA sincti examiiBatkNii^f thesttfipofiedcJ^ 
skltic columns bfEtna, lirhere Its vast lavas 
.enter* the-sea^ ndghtiako j£ad.<to sGme.ooB- 
elusions, whether the opinion of those phi- 
losophers be jua^t, who argue that basakin 
is always a volcanic product, its compact- 
ness arisingirom its formation under the pri* 



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f!gi DOMAIN Xlf. VOLCANIC. 

meval iviater^ like most otker rocks, at a 
period when the power of erystallisa(ioii 
was more vigorous, as appears from all the 
other primitive substances; and nothing 
can be more rational than to infer that vd* 
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*. 
Fenrnm's Fcrrara, the intelligent professor of nit- 
tural philosophy in the university of Ca- 
tania, has just published a learned work on 
the volcanoes of Sicily, and the adjacent 
isles-f*. This treatise is certainly important 

* * In his grand and surprising course of lectures, 1811, Dr. Davy 

' is said to have produced an artificial volcano, being a hillock of clay 
CDelonag a mii^re of potassium, inm, and lime: on penriBg water» 
smoke, flame, and lava, issued from the crater. The earths, he con* 
ceives, may exist in a metallic state in the centre of the globe, and, 
combined widi water, may become earths, and suppty new oor- 
tinents. 

f / Campi Flegrei delta Sicilia, e delle isole che le sono intorno ; 
o Discrizione Puica e Mineralogica di queste Isole. DelV mhaie 
Francesco Ferrara, Professoreprinuuio di Finca nella Regia UnU 
versiia di Catania, DoUore di Filotojia e Medicina, e Socio di varie 
Academie. Messina, dalta Stamperia delt Armata Briiannica. 



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DOMAIN &II. TOLCAWie. $%§ 

in tbe history of mineralogy, as it seatDS to 
decide some pcnnts which were before 
doubtful^ and throws fresh light on many ctf 
the most interesting topics of the science. 
After a long and patient investigation of 
all the lavas in Sicily, and the neighbour- 
ing isles, he has opposed the opinions of 
Dolomieu; whom Ue justly regards a^ a 
cursory visitor, who would have retracted 
many of his remarks, if he had simply 
twice visited the same objects, the firiit 
ideas being often corrected 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 emeiged from ttie primeval 
ocean. But he is at the same tune as de- 
cided in his opinion, that all basaltic co- 
lumns are the product of primeval sub- 
marine volcanoes. This position he does 

1810, 4to. ^^ The Burning Fields of Sicily and the rarrounding 
isles, or a Physical and Minendogical Description of these Islands, 
by Abb^ F. Fernra, princt|)al Professor of Natural Philosophy in 
the Boyal Unirersi^ of Catania, Doctor of Philosophy and Medi- 
cine, and Member of several literary Societies. Messina, from the 
press of the British Army, 1810." pp. 424. 



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(WUWfalogJHls, l)nt /to have a4opted fso^ 
d)is .QiffU lObiiervation. Fqr this iiii^peD<^ 
.wbioh itp ^okoe maj seepi ar^iiti^j, ^^^ 
«KreQiT«9ioo»fy> is founds on m i9du|^(^. 
-We »^t itbat cuweftfjj ,of ilava, perfi^df^jr 
.ideotic .with^that. of the histprical .aiid la^ 
4igQ3» rate .'found :^v^eda and.Qf^ eyea 
;jdteraAting, with products, i|niy«rsa|lj si^ 
lowed to have I been d^pp^ted .bjr.the pq- 
.«iQval wat^^, such as thji^k jbecls. pf 4^alk 
.Mtd'tinoestoQe, :99i9«tioieS;<^mpact> »Q9IQ- 
.ttnes ^ooobitic. 
"c^g^ By bis apcpiwt, and the . n^Q^b^gictl 
map .whk;h acpompa^es his yrq^k, the 
.whole of Sicily appeajrs tp.l)e iO^l^^ai^i^s, 
.except lihe .xMuyp^iiis , pf .P€;|9ro, in . ^ 
■4aorth-Qa6t . corner, ■, whiqh , coQ^§t , pf.ff^ 
-granite, ofton eQy^f4<wi|:h..aiJbed,.of,)M9M^ 
.ctoae. Initbat quarter, j;)^^ a bijipdjxyi 
mines were formerly wrought, producing 
abundance of silver, copper, and lead. 
-The limestone .ofJSicily is ,oJ&^, in t^e form 
of what he calls Cretan by whidi he does 
not seem precisely to undei^ta^d ohalk; 



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ht Ireland, «hd wludi M^ aTsd hteH 
called cfa^: Itf tithUi pki^ fte)« dref (^ 
ikhst^e la^ef* bf TtiJraW^i #laclfc cteca^lttW 
sily, ijy Msr accounfv ptiss^ Mki ^ h^tm-i 
tiful agates and jaspers, for which SiCSly H 
famous ; ai It a for ifi Siii^lar' ih^e^s, 
s^knlhglj^ dfii^cted By flie tbkftttic f fti^Qiii^: 
Hie chklk lie r^rd§ di iKe hetse Hf fiCAS 
iisdP, Vliieh h& bonsiders as Bei6g «fltif«^y 
« H>leknic in^s <^ a likHdf^ mks iM ^if^i 
ctiii^ ejebted bf the pfbdigidii§ e^b^ai «f 
ihterdal i^riitehtatien, i^ich ^ihd^ i^ fim 
aiibn faaii a^lilted SibU j AM Ihii ttdjtt§eif 
i^Ieii knd toa^t bf Italy; %M wHc& fiiUfif 
^iBt, ki he ih^r^i dt il di^ alMost kn 
ediicdVkbl^* I%e VIHie^tiM ^ th« iftt^4 
sity of volcanic heat, he regards as A^st^ 
ak^^aSSa^ b& e&^tiiiiSt^d^, Mi&g «ome. 
^ites gi^^ iMf^iSiiie^ ]ftd%i«!W!; «hd tti« 
quantity of liquid lava may be esteemed a 
standftffd l>f the eeti^^ «f tbe firei His 
*(fe^tifiiafe?>rV61cdJilfc'^VbdWcte ii «l« fe^m 



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'SOU DOMAIN ZII. VOLCAVIC. 

c^ that of F^ujas, being extremely simple 
and confined; and he confirais the idea 
which I have long since advanced, that all 
lavas consist of siderite and fdsite. Hie 
former, with Saussure and other writers, he 
calls pietre cameCy being a comem of AYal- 
lerius*. 

The study of extinct volcanoes he con- 
siders as, perhaps, more interesting to the 
naturaUst, than that of the active^*. 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 products of submarine volca* 
noes ; and his account of their origin may 
more accurately be expressed in his own 
words. 
Origin of . ^* As a perfect dissolution is necessary in 
order to form perfect crystals, so a perfect 

• p. 291, 343. 173. 

f " Lo studio dei volcani ardenti non essere il solo che |M)6SIl per- 
inioiiaie la scicnza; che quetlo d^li estinti \^ a oerti rigoardi, pi a 
fecondo di lumi, e non meno del primo degno deir attenzione^ e 
ddia premuia del Nttucaliita«*' XhVc. FreL p. iv. 



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DOMAIW'XII. TOLCUVSe. 308 

fluidity ift required in stony substances^ 
that in their consolidation, after their dis- 
solution by fire, they may assume the forms 
to whibh they have a natural tendency. 
It cannot be denied that many modem 
lavas have all the fluidity of which they are 
capable : what circumstance then has per* 
mitted the ancient* lavas sometimes to as- 
sume the form of prisms, which is entirely 
denied to the modem ? 

^' A lava which rises from the bottom of 
the sea, must be consoUdated 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 frotn beneath, 
must break the. upper surface, and occat ' 
tion the lava to accumulate on itself. The 
aides^ however, remaining always consoli* 

* By this woid he always undentands, aa he CKplains himself • 
the primeval submarine volcanoes. 

Hie sopposes, p. t$Q, that the locks aie lendeifd fldid fay elastife 
wKponn, tapori ebuiicii andijrom their resemblance to rivers, ar% 
Uke them, called iavine or lave. Does he refer to the Sicilian 
4ial«et i In pure Italian^ lfi»at$ is to wash» or water. ^ 



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dstedr aid kngtb the mass appears abave^ 
ike waters; ami the entev which naaa- 
flboive Aie iravesy cemrewaqatiny yndib IrW 
soonse «f tbe; file, which caa»at be imir^ 
dated, mny thus; conktiMHS! it» explnkHia* 
In thn- raamoer wcf e ifecraed, ev^ci iitfMv 
timed^ mMy iska in the GieeKm arefaipe^ 
laga ; aiid in this maMneF »aat hard imtm 
fbmied the Eolian iska^ and otlicr voicauie 
rocks around Sicily. FkMuttj, when theei^ 
Aagmtion ceased, the lavta w^iidb formed 
the gveat masa upon the bottom of the sea, 
while it was smrfoimded an all sidet with a 
ti»ck arrect of the same matter (now eold 
and a very bad condnctor of the internal 
iire) which ooght to asMune the tempe» 
ratare cf the water), now enclosed, both 
foenenth and above, with the same lava, re* 
mains in the intenial golf, in the inoii 
perfect fluidity that it can reoeivis ilbm im, 
to which it has been so long exposed, and 
in a condition to suffer all the activity of 
the subterranean Aimace* It i^ very piD- 
foable that the lava in this recipleat, having 
the necessary tioie, ipacet attd toHiquiUkjr^ 



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0OVAIV XII.- VOfiOKVIC. 505 

cbqIs dowlj, aDdcoiiddiiseauiidei>tib6>fbfiQf 
to which jtotnature tends*.. For^irhat is 
ecystaUkatibii but the efiect oiififiiiiiilar in^ 
dinatimi dife the more simple, mmilar^ andKi 
attemated particles of.ioatter? It appears 
4o me tiien that this tendency, being faci- ^^^' 
li£iiled.b}r the circumstances here indicated^ / *. 
esf^ains tiie formation of prismatic lavas^ \r ^' 
wtibofttt^ODnfoondiog them with the pn> ^ 

ij|Mxi'Ci7staUisalk>n."t 

M§&.aD I example,. he >inentions the rock 
t£Motla^which/wi6h those. of the Cydopb 
fai-Jh&SL aiao engraved, in. .the rude manner _^ 

aoir.pcactised in Sicily. He observes that^ ^*^L^^ 



* '* AliP9te«BmbiiiatioD, upon » ray small scak, may bare pnv 
dofed the &w prisms which are found in the upper .parts of Etna, 
aAdlDtewiie io'die'Eolian Isles, not to mention Vesuvius." 

QaxjunmiMtM thown.that schiitoae svbstaiioes^ when m^ed by 
die vokai^c bott, will reassyme the same form. But what does he 
eoncOTe li> be the natural tendency of t)asaltin ? The forms he de- 
scnbes, are not onl^ the (M-ismatic with articulations, but that of 
^bfUi iritiicooeentnc layers; and others, in which the. pnsms con- 
ttaet and noeet in the centre, like the balls of p^ites found in chalk. 
'Ki'Mi'iroD often assumes the prismatic and globular (brms, and 
iiilfi^bn liditled and conoentiic, be oi^t to have referred the 
wfaok to that metal, so predominant in siderite, which forms tht 
bair«rdiQe kras. 

VOL. n. * X 






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m Xtt. YO&CAJVM^ 



\ 



in this and okb^f iBBtanoes, the centm aione 
is ia.the prismatic forms, vfaidb are somo- 
4niiies €(m(iA enclosed in amorpkous lava, 
^ identically^ t^e same with the coIumiiSi 
•om^tfHies in tui^. and sometimes eyc& ia 
/^ ^ole^dic glass. But he seems never to 
)iave sesn or ohaeffirtti the remai Hstble artk- 
eulatioBfi, not only ooavex and eoncvv^ 
^ Jbaii strengthened by pix^oting angles and 
recipients, which Miete. iiist iiotioed aad 
engraved by £>a Gosta, aufi aftervarda .by 
INotet;, in their repieseiitationaof the^^ts' 
causey. TfaisstrikingcharQcterislac, adiielk 
4^ *^ " #eems unaeeouatably ta have escu^Msii most 
f^ *• '^ writers, can scarcely be ascribed to mere 
desiccaticm ; but seeas rather to wwbI the 
process by >¥lwQh nature produces regular 
rook crystals, in the vast cavttna of the 
Alpsiof eno]:mQU^ size, apd weig^g^many 
tons. 
coimniis o# Other basaltic columns occur in Sicily 
at Yvmm. where the CQlmans anei Moxir 
lated and a foot in diameter, but only a 
few feet high, curiously arraggpd QU a 
curved basis ; and they gradually become 



V 



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'tS 






OOMAIlr Xtl. VOLCXttlC. 



itregulaf, and pass into the amdr][^ou9 
lava. At the Motta, already mentioned, 
they ate about two feet ih diam^tei'j partly 
rerticai partly inclined. At the bottom of 
the colonade the peaszmts made an apeiv 
tuTC) "^etet on introduci&g ihe ht^^ htki 
was petceived, and the hand fimelted of sni* 
phnr. Abore are great masses of sand^ 
red drosses, and pttazdlatia ; and he infers 
tiiat the prisms alto in Hfi centre^ of the 
Yolbanic mass. It fiffiay be said indeed^ 
that beat thus enclosed becomes inextin-* 
gttidhable; and he mentiMis that, two years 
AigKy, the lava of 1669 being perforated at 
Gtitatti&, flauMs issu^ ; And wHhin these 
eight yeten it yielded, after nan, smoke 
And gMM hettt. This lava is about two 
kuodved fe«t in depth, aiki two miles in 
bfeaddi, atid had ran about fifteen miles. 
Other bas^tic cohimus appear near Bronte, 
CM the west df Etna, which gave a title to 
the glorieos" Nelsoil. They htt ih beau- 
^dl hexagonal groups, which disappear in 
the incumbent chalk or earthy limestone. 
Some not only project ftom one centre, 

xs 



30f 



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30^ DOMAIN. XII. VOLCANIC* 

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 
ion its east side beautiful columns of prime- 
val lava, disposed in the form of an organ^ 
like the Organ Rock dear 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 bluii^ volcanic 
^lass. * 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 tuf&, 
l(« . 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 ihave 
add^d, marks the same influence of iron*. 
iaJl%™iiSluc. Our learned author totally denies, even 

. * p. 95, 1X6, 123, 135, 137. 



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^ # 



DOMAIN Xlf. VOLCANIC. * , 309 

in opposition to his friend Spallanzani, that 
the modem 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 equaU 
\y observed in those 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- M. 
cano, but to the ancient volcanoes under 
the ocean ; and that modem 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 Etem, and some small ones in the 
clefts beneath, must, from their singularity, 
be ascribed to an accident, which can never 
establish a genei;al system: and I am of 
opinion that to the same accident may be 
ascribed the two or four prisms, whieli 




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^ 






310 IKMf4I9 3(11. VOI.OAVIC4 

90016 naturalists have found in other 
dem lavas ; and the great differ^ace ougbt 
to be remembered between these seanxi 
trifles^ and the vast masses of prisms, groups 
of columns, and fascicular assemUages^ of 
vrhich even the fragments tend to regqlac 
divisions, which constitute their cfaanu>f 
teristic quality/'* 
liven the amorphous lava of the piime* 
)jw Tal period is very compact, sprinkled with 
filiform crystals of felspar, and some of 
siderite, with grains of chrysolite. That 
of Cape Passaro takes a beautiM polish. 
^^ The prismatic lavas are very hard and 
compact, and always of a dull ashy cdbur, 
or a bluish black ; and I have never oh* 
^rved any pores in prismatic hv9tJ^^ 
Among these primeval products is also 
found black or blue obsidian, somethnea 
in fragments, sometimes in tables in thfi 
slits of the lava, and sometimes, ooneave, 

* p. 144. He had before said, p. 1 12, ** In generale posso dire 
Ghf h bve pxisniatlcke,. le lun faisahiD*, i baaiUi, dieMOO intotBO 
alia base dell* lS,ya$, appacteQ^ppo 4g^ Aumcmi yqIiC^ji^ e V/f^K 
mai alle erozione moderne di c^uesto volcano." 

t Pi 174 




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V 



m 



JMM«1V XII. TO&OMMa 9H /, <* 

-♦ 

w enveloping faatU^ of larmi > Frdgm^ts 

are also found partly glass ahd partly lava^ 

the former appearidg ia delieate Teiiia. ^ 

While tbe lara is decoinp<>96d into blacik 1^ 

ferruginous earth, the obiidian passes iilt<^ 

a light ashy substaHcei Thd b«bblrai and 

cavities ^re fM of calcal-eoos 9pkt^ while jf ^ 

otfaetiy though rai^y^ present cooftliied i^ 

bry&taAl of whif^ and f<taitfatispat6iit 

In fiite^ dui' labodotis and nrteiligeAt 
Aitbor cimeiiided that '' those Nepfciroisrta, 
trho deny the voloamc drighi eif the basdltie . "^ 

colamiis of Sieity, must ne\^ have di^ ^^ 

served thetii, else they nnght imve seipn 
them surrounded with amorphous lava of ■, a 

the same identic paste, and often con tin u* 7 

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. ^^ 



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3 111 l>OMAlir XII. TOLOAiMlC. 

, If the observations on this curious 

/■ 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. 

^N f The account of the Folcanic substances 

vt will extend to considerable lengtibu-^JSbd 

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 Ibeen objects 
:^^ of repeated disputes and contestations 

i amoijyg the mineralogists and geologists. 

, •> 

'^ 



4' 



• 







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VOMB I. COBfFACT LAVA. 



NOME I. COMPACT LAVA. 

The Tciignc substances are of such Taribus 
kinds, "1^$tTvxeir arrang^tnent becomes gaore 
difficult. ]^7 far the most important substance 
is the lava, which must be considered chiefly as 
it* is compact or. porous, the former requiring 
l^hioular atteig^. In Karsten's catalogue 
tbeie are only Imvbits of lava; and as Buffon 
bad.pfepidices against certain; rocks which con- 
tradicted his system, so Werner seems absolutely 
t^j^nt his eyes upon the gt^andeur and import- 
«q|| of volcanic productions. Hence they are 
tre^ed with great neglect, and may be said to 
be excluded from German cabinets; whilie, to 
the impartial observer, they convey sublime ideas 
of the wonderful power of nature. 

'As the opinion that basahin is at least some- 
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, k very often contains grains^ or even no* 
dales, of olivine, or what has been ^aUed chry- 
solite; and zeolite forms likewise a common 
parasitic substs^nce. Neither of these, it would 
appear, is found in siderite, or in the basalt oft 



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Basaltui. 



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nts ; whose most common admixtures me 
and felspar, and in some porphyries , 
^halcedony. Thi» observation^ if exact, wooU j 
seem of itself to indicate a different origio/ Sor 1 
if boialtiti were mecelj the moi^-^iril^ And 
compact appearance of the sideroM ifeHiMM% 
bombleiide, utd grunBteui, as asserted hf flia 
Werneriani!^ it seena dificult to imagiae #hgr ili 
yMraaitfs.shodd thM toteUjr dUfer. ChtTsoSla 
or divme als9 oocara In the iwiiian of watim 
■ron^ and other stones sasd t# I&to fiiH« imm 
the atmosphere! and which are well kM«i M 
appear in the form of fiery nopetaocs^ andtobeie 
ether palpable oiaclcs of ftiscow by heat*. 
-Utttngement In this dtrbion^ the tenne BTfx»»oKiJ|b .^ 
•^ incROKOiis, imfdyiog greater asd smelter fib* '^ 

^yf^ff^ divisions of the Nome, will becense still mtmA 



Beeessary, and More strictly applieayc^ 
though the subfectS' rceemUe each elbav l^f 
are wideiy difiereat m a geological poiat of 
view. The want of suck dmniwiaalinei baa 
obliged the wriiera on yolcanic |>eodiicli to fr 
lide then into new and uaasaal < 
and qMcies; m mdatioa of the dtfaer 
of ndnmiagy, where these teras beaf qwia* 

* IVdiapt ia a kcftlad ttatetke ingDetU 0^5 combtiM widi iH 
X \ Ax, and the potash arapoiatei k> that felspar and nufpnm wff 
^ jjhfffiifleolMfle; 



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different interpretation* Hepqe Ht^ geoerti^ 
Dolomieu are^ 1. Compact lava. 2. Porous la^iC 
S, Scoriae, &c. &c. j while the genera of Wer- 
ner are Flint, Qay, limcj &C4 Here, on the 
contrary, basaltin remains a mo4e among the 
siderow substances, being only a different qom* 
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-t 
stances of quite distinct natures, but all altered 
by fire. 

HYPONOMB I. VOLCANIC BASALTIN. 

^j; Volcanic basahin from Etna, Vesuvius, the isle 
of Bourbon, &c. 

The same, with rfivine, from the isle of Bourl 
The same, with zeolite, from Etna. 

Mkronome 1. The same, with various sub- 
stances involved in the vofcanic torrent. 

Mkronome 2. The same, with fragments of 
ejected rock. 

Mkronome 3. Compact kvB^ ^ith melted gar- 



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DOteAIN XII. VOLCAVIC. 



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ni% fix)m Vesuvius. 'Rie appearance is rather 
vitreous. 



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HTPONOMB'II. POROUS BASALTIN. 

The three very compact homogenous .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. • 

*' These lavas are commonly of a blaqk colour^- 
more or less deep, seldom grey or brown: their 
Iftcture is imperfectly conchoidal, their contexture 
very compact ; they are harder, but more brittle 
than trai>, rather sonorous, very heavy ; they melt, 
IKler the blow-pipe, into black scoriae ; Ihey 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, 185, 




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V 



NOMB I. COMPACT LAVA. 31?. 



I 



f. 



^^ It is seldom tiiat they are homogenous ; they 
are, on the contrary, almost always interspersed 
with different minerals ; those /which have been 
mo0 remarked are felspar, augite, hornblende, 
gamft, leudte, olivine, and mica."* 

Recently Breislak, certainly an intelligent writer, ' y 

mentions many kinds qf compact lava, without ^ 

any notice concerning their rarity or singularity f. Jt^^ 
Ferbar, an unprejudiced judge, likewise gives aperbcrtidcai. 
calalogqe of compact lavas, amounting to fifteei^ 
kinds. He especially says that the common black ^^ ' ^ 

lava, which covers^p^suvius on every side, is 
porous on the surface, spongy, and light, and 
therefore employed in vaulted roofs; but at a 
g^neater depth it is extremely compact, and then 
Itoed in foundations, and in paving the streetsj;^ 
Yet .he compares it with slags ; and speaks of it$ f^ 
being mixed with a reddish iron ochre, like the 
rocks ynder the basaltin in the north of Irelandj^ 
and ^Qlbe Faroe isles. But Ferber possibly 
means ^ny 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. 626. 

t Voyage dans la Campanie^ Paris, 1801, 8vo. 

t Letten on Italy, p. 1S4. 




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316 Domum xn. voLCAvte. 

tf^'Hf^ i^« •^/u'e ^MBtferaUe labcmr and ttur 

^^ ' .^ jeempiofe* to arrive at the true ooapict 

jtt^aiaa be remembered that F tfb ef i i ^A 
f*. 2.,^ a^ a volcfiiic j>roduetion, io wiacb k \% 

:<vi;a by afanost every writer, Gmnia or 

2t^ wha has visited volcanic comitntt. A» 

Werner's plan never to decide on sabrtneo 

Vv. .*^^cH», which be has not seen widi his ova 

.:s it is nuch to be r^etted ttrnt he dM M 

^ \'ewvius, if he could dot attain tte m^tttie 

cjie^of Etna. 

Wfade the French writers are oftfti lo fi^ 

' i(OMliBfiiv!(mrof volcanoes, that with te Miry 

« .. 4Mk or vesicular stone is a la;va: ani AlC^- 

^^ iMMv on the other hasid, deny even dMteinil 

r^ nwake ti> be vofcanic; both sides itfjai^tkr 

jfMi caase by pushing it to a^ absu^enw; 1 
^■vr be sati^ctory to know the ideas ^^M^t 
^k» h at least i^gkrded as an unpi^jiidHPvT^ 
Inides the black homogenoos lava, dmett^ 
WMd, hb other compact sorts are bhdt ^ 
Incites, with felspar, with aMerite, viVEtdirp^ 
Ir; with vesuvian, with obsidian. He dik^ 

• Sau^Lirc, i. 1S8, 4to. has obsenred, that comjptetkfiii^ 
^m^ ukI found only in the interior of ^ catraoL S^iboFenn 
p m%t *' h parte baisa dei torrenti ^ fixmata dl Jairs piooat» 



if 








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xoME^ 1* coimkor ul^jl 



919 



kinds of giey eonifiaot ImTa, itith dderite, augpte) 
felspar ; and red compact \asv^ with ieucite and 
febpar. But by his immediofit' traasitiea to the 
iqrib^ the sand, and tie powders, he wouid rather 
lasia \j iHm tern compact^ to iiiqply a vague dis^ 
tbdHi fioQOEi the hose subrtances^ thim a strict 
appticalicm of the word: and this, amoog^a lte)«h 
sand instances, may show the necessity of anst^i^ 
bmgoage, and (he sMst predse defi«ki0ii& m miJ!^ 



M 



Saigaft used to indicate ftmdiffevMttei^ ophiimior 

tftp and oampMt lava. KTtop k^soift^aiidttiaj^ 
haetTKldied by a kntfie^ whieb bn^lava loses ed^^ 
8. Trap attracts iron, but lava is a magpet. 3. 
laehctricHy, lava acts like glass. 4. There is no 
<£b4i^iatra|vbutitis common in lava. 5. Trap 
ia i^l«Ma beeoines a ttraaspaiMt i^aas^ but kfva 
renums opake. These (fistanctions will no^ how^ 
9v«r| ht admitted by the Neptuni^ts. In Bran- . 
gMn^Vipwiimi, iMHViMCi Iwa akwaya presents a 
fgfwi^ BQUNyiMbat erystaUised^ in which it dSuers 
froBi tnqp^. If basaltic columns be found on 
JEtm^ tbenr origin oiay stiU lem^ dubious ; iatj 
•ecQRliD^ to Gioem, Ae radical parts of that 
mmptaiQ are basalt, which is only concealed by 



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518 MtCfMAlV %n. VOLCAKtC. 

1 "v ^1^ durrfiu^e; irldte cdtlsiderabie labour and dtne 

^ * mtfst be employed to arrive at the true compaet 
lava*. 

It mudt also be remembered that Ferber i^^|itfdg 

I I:)a6altin as a volcanic production, in which he is 

i foSowed by almodt every writer, Gemaan or 

French, who had visited volcanic coontries. Ad 

7 "^1^ ^^ ^^ Werner's plan nev^ to decide on substances 

^JjL ' ' or negbtks, wfai^h he has not seen wiHi his own 

' f^ eyes, it is much to be regretted that ha <3&i Mt 

4 ^ iisit Vesuvius, if he could not attain t&e majestic 

scenes of Etna. « 

%t^ Wh^ the Freiieh writers are often so prcj»* 

^ ^ced infevsour of volcMoes^ tluu: with theoi evety 

% < ^ > *> Made or vericular stone is a la^a; and the Ger- 

j - ' ^ Biai^s, on the oAer hand, deny ewA obsidian und 

I- / "^ "^ ptimice to be vokanic ; both sides ittjurbig tlicir 

^Jb^ ^ij^ ^^^^ ^^^ ^y pushing it to soi absoM exoess; it 

tt^ '^ ^^B?^ "^y '^^ satisftictdry to know the ideas di feriDef^ 

I'i.^ 'W wl^katleasti^g^efdedasMiif^)^)^ 

.^ ..^ Besides the black homogenods lava, anm^ veath 

tioned, his other compact sorts are bfack wiA 

fcucites, with felspar, with sMerite, with chryso^ 

Rte, with vesuvian, with obsidian. Ifc adds fbof 






■Li* 



;^;f * Saussure, i. 1S8> 4to. has obseired^ that compaot kva U Teiy 

.^^^ nK> and found onljr in the interior of the cornnt. So idio Fenan^ 

'* ^, p* 301, "la parte bana dei torread ^ fiacmata di ]av:» pki o r^^^ 

compatta." 






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xoME 1* coimkor sj^jl 



919 



I cf grey ebvup&ct laTft, yiith dderite, augite^ 
fidspar; and red compact l|^.with leucite and 
iebpar* Bui by fais immeda^ tnoisitiea to the 
lapiUh tbB sand, and tie pimdeHB, he wouid rather 
mam ¥y tba term compact, to iiiqply a vague dis^ 
tbdHB fcom the 2tHMe substtiMes^ than a strict 
application of the word: aiid this, aiaiociga.tto«h^ 
sand instances, may show the necessity of anstewb^' 
langoage, and &€ usst precise dafiMtiow m m^ 



\ 



An^ usad ta indicate ^wdiffeiieMeff bet^^ 
oampaatlana. KTfap it^soift,andmay 
h0 saiaftdied.by a knifie^ whi^ bn^lava loses edge. 
8. Trap attracts iron, but lava is a magnet 3. 
fce te t trlcfty, lava acts like glass, 4. There is no 
oGbraieiatrap^butitis common in lava. 5« Trap 
m M faraMa beeomet a ttraaBpaiMt |^as0> but lava 
remains opake. These distinctions will no^ how- 
ever, l» admitted by the Neptonists. In Brcm- 
Bpiarfttproicn, aompaei Ifum aliwayapresests a 
gnii^ mnewhat erystattised, in which it differs 
from trap^ If basaltic columns be found on 
JE)tn% tbenr ori^gln owy stiU remaia dubioaa ; iat^ 
Mcofding to Gioem, Ae radicri parts of that 
VKmntain are basalt, which is only concealed by 



ion of 



Opinion 4 
Fiigas. 



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S20 



AOMAIH XII. VOLCiailC. 

the lava3*. But F4wrrara seems to have decided 
this inquiry. 

Porous basaltiii^ with olivine^ from Etna. 

The same, with leucite, from Vesuvius. 

The same, with.augite, t^e pyroxene of Hiafijr ; 
which contains about 15 of iron, and 
mere, modification of siderite. 



•? Micranome 1. Grey compact lain. 

All lavas, as already mentioned, with a few 
fling exceptions of mere curiosity,: may be ckssed 
in two divisions: those with a. base of sidoita^ 
fmd those with abase of felsite. The grey kvM 



% 




•^x, 



s 

^ 



• P. 52. Chrysolite^ or olivinef is oomxnon in natiTt i 
in lava, ib. 217. Gallitzin (Rec. des Noms, Bninsw. 1801, 4lo.) 
mendoDs an iron ore articulated like basalt> mine de fer en ^mtef 
mrtieulh, eomme ie Imalie, Biochant ittt a ted hemitite of umi km. 
prbms, from the Fichtelberg near Bareuth.' 

The pretended basaltin of Wales^ observed by Strange and othcn^ 
at Cader Idris, is^ according to recent and more accunte obsenrcn,- 
a coane grimstein or batahony in mde obkmg fragments o ccjai o p Bi 
by fissures. Appearances ihore volcanic mty be traced in the nof^ 
of Ireland ; where the red earth resembles pUKzolana; die kr9g of 
Kirwan> found near Belfast, is very p&rotu ; and the mmUen seems to 
some^to ash-grey lava with hornblende. Dehic, Geol. 273, ex^ 
presses hb belief in the extinct volcanoes of,C<rmfuiy» and sqft that 
sections of lava may be observed turned to a. central point, and 
forming clrcEr^ of bills aroiind an empty space, the focus having 
sunk and tlLSApp^rcii. He calls these volcanic crowns; and the 
centre is oftcti a iak^ 



i 



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MOMfe I. COMPACT LATA. 3^| 

often belong to the latter divkion ; but are sotne* 
times so intermingled with siderite, that they ap^ 
pear delicately dotted or punctuated. Vesuvius 
presents lava of this kind, which, in spite of \he 
interspersion of mica, receives an admirable 
polish. 

Faujas, in his general classification of volcanic 
products, has denominated this kind Imvcs feld- 
spaihiques; and mentions one which is black, yet 
melts under the blow-pipe into a white amel. 
Some, on tfaie contrary, belong to the white com« 
pact lavas, about to be described*. 

. The grey sorts are, " Felsite lava, of a cleai Oiwtawar 
grey, sometimes bluish, sometimes rather greenish, 
or white a little inclined to red, of a fitie 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 diffisrent 
from that of the base of the lava, 

* In his ideaSj trap resembles felsite ; but he forgets that iron| 
always a most predominant and characteristic substance^ is wanting 
in felsite. 

His classification of volcanic snbetanoes was first published in the 
Annalet du Museum i and latterly> with great variations^ in his 
Geologic, tome ii. The extracts here given arc generally from the 
former^ which is more ample and instrtuitive, on some topics, thai^ 
his last revision. 

VOL. II. T 



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52S ftOMAXll XII* VO&CAiriO. 

'^ Felsite lava of a grey white, fine paste, scaly, 
. and of a shining reflecticm, and satiny, of an ana* 
logons nature to the preceding in respect to its 
eomposition ; but diffisrs in as much as the acti(» 
of volcaiuc fire has impressed on the paste a cha* 
racter of fusion similar to that of pumice, vhilie 
ike granular fragments of felspar, whiter and of a 
more diaphanous nature, which are unmeised in 
the massive felspar, have more resisted the actkm 
of fire, and remain neariy untouched. 

*^ Felsite lava of a deep IsakeUa colour, with 
grains of white diaphanous fekpar, and a numbef 
of small specks of black mica, wbdcb have re- 
mained untouched m the midst of the striated 
base, ratiier porous^ and passed into the state of 
pumice. Thb felsite lava has relations witii titt 
precedkig ; but its contexture is more rou^ and 
its pores closer ; its aspect has an appearance of 
pitchstooe; which obtained it, fix)m Dolomieu, 
the name of redrnfum^ Java. 

*^ Grey felsite kva, with a multitude ef SMall 
globules more or less round, and inherent in the 
base, of a substance analogous to that of felspar, 
of a deeper colour than the paste which contains 
th^n, and in which they have been primitively 
formed : their contexture is closer and rather 
vitreous. Thi^ lava, which is hard^ and suscep* 
tible of being polished, appears spotted^ and pre* 



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senta rerj saM Imeamento of bkck mka; 
scraikehes glass, and mdtto luvier tb& bkw*pipe 
into a greyisb wUte wndL. 

^ F^aite tma, giey, ukl sometiines^of a wfaitiili 
grey, aoMJogous tQ the foregomg,. niA^ \km Affiev- 
^loe that, ia tki]»y the paste,, whiek also cocloaeii 
aaNua Kneaaaeate of black aMP% id laoaer aaA leaa 
adfaaitat, and that the «pliipfiral giobiilte ane ntudk 
karger, aod el afehpar a littib "ntEacMia, hot ver];^ 
caoaqpact Tbe;^ casmtst be hette cooipartid thaa 
toJaf^epcas* SoiaespeckasBaaiefiiiiad^ wheia 
the base which contains them being in part da- 
atea;^,. tfafif^obuks hnte vesiate^ Md 6ff» aalhnt 
paobuJbaFaiiQffi irilicb ham a Mm appaanmce of • 
arbacalar ccjfstals. Time coatain iit^ar iatenor, 
as wellaa oa Iteir sarfiict^ Momm partialis of fA^ 
spar, whiter tfaan the ^bular paste wUKbeoatains 
IlieBi; theia are alsa sone specks of bkck mica* 
it ia profaaUe that these gbibalaa mi^ pass into a 
kind of obsidian called lucks saphir^ yihea a nolent 
heat produces vitrification/' 

As the baae of this hma coasista ef febpar or 
ftkite, it is oftaa vary coaapaet In dascnibing 
an immense current, which descends from the an- 
cient crater of Etna towards Maseafi, Dolomieu 
says that it lies under vesicular lava, and is of a 
very fine grain, and conchoidal fracture, likeipearQ- 

y 2 



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324 BOMAiir xiir volcanic; 

sileXy that is felske^. There are some white spoto 
of undissolved felspar, and some specks of siderite, 
which occasionally appear rusty and 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 locoes silicSes also belong to this kind, being as 
compact as porcelain, with spangles of black micay 
while sometimes there are long fibres, as in melted 
glassf* 

Breislak says that the grey lava, whidi issued 
from Vesuvius in the noted eruption of 1794, 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* 

Micranome 2. White compact lava. 

This land is uncommon, and must arise finom 

* Dolomiea Etna, £40. See afterwards Breislak't aocooal oC tlw. 
eruption of Vesuvius, 1794. 
t Ponces, 104. 



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HOMB I. COMPACT LATA. 325 

pure melted felsite.' Dolomieu specially observes 
that the tint is original, and not derived fron\ sul- 
phurous vapours*. Even earthy la.vas 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. 



HYFONOMB III. FOBPHYRITIC 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 the follow- 
ing account^;. 

^^ I denominate all those lavas porphyritic^ 
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 spedes is most common : it in itself con- 
stitutes more than half of the compact lavas of 

• Etna, 161. 

t P6nces, p. 71, and 109. 

i Dolomieu, 212. 



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326 BOVAIV XII. rOLCAMie. 

Etna; it may even be said that porphyry is the 
essential base of aisiost all the laraa of that vol* 
cano; ttrt it cWciy diaimcterises the production 
of Etna, and <tiBtiagui8bes it fron other volcanoes^ 
where in general porphyries are mofe raxe. 

" 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 varices, the accidents of the 
fractures, which, according to their directkm, 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 found in some antique porphyries. 

" The base, or ground of all these poiphyritic 
lavas resembles those simple lavas ' described in 
the first species : some, however, are more sub- 
ject to be inflated, and have a more vitreous grain ; 
besides the felspar is never altered in its form, or 
organisation, only sometimes it is a Uttle 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 



i 



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NOMB U COMPACT JbAVA* Sfi7 

blacky while the felspar whitens ; it then acquires 
the property of strongly acting on the magnet. 

^^ Most porphyritic 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 Etila is 
of a greyish black with white spots, the bdse 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 
rocks. 

In one of his porphyritic lavas he observed 
crystals of specular iroQ ; and as he also observed 
this metal in the same state in the dipss of Monte 
Rosso, he concludes that it is formed by sub- 
limation**. 



Etoa, ; 



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328 DOMAIN XII. Volcanic. 



NOME n. 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. 
Anaiyss. From the lava which contains leucite, Vau- 
quelin derived silex 53, argil 18, lime 2, oxyd of 
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 the attempts to ex.- 
^^ plore the source of this phenomenon, ttie sum- 

ttommit of mit of a mountain so interesting to curiosity and 
even to science. But the best account is that of 
Spallanzani, at oncfe a natural philosopher and 
a mineralogist, and who has sprinkled his de- 
scription with some learned anecdotes of the his« 



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NOME II. VB8ICTJLAK LATA. Q^^ 

toiy of this celebrated mountain. Its length 
and minuteness will only render it the more ac- 
ceptable to the intelligent reader, especially as 
they niay 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, left the Grotta delle Capre^ which had 
afforded us a welcome asylum ; though our bed 
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 
exttasive 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, 



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S90 i>OlfAIN XII. VOLCAiriC. 

those ia \(^hich the Gr&tta delle Capre is hol» 
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 bi 
night Faint gleams of a whitish light wew 
succeeded by the ruddy hues of Aurora; and 
soon after the sun rose above the horizon^ turbid 
at first and dinuned 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 lofly 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 
DroflMs. the Chevalier Gioeni^. These were visible in a 
coating of black scoriae, at first thin, but which 
became gradually thicker as I approached the 
summit of the mountain, till it composed a stra* 
tum of several palms in thickness. Over these 
scoria) I was obliged to proceed, not without 
considerable difficulty and fatigue, as my leg at 

* *' His account of this proption was printed at Catama, in 1787* 
There is likewhe a French translation at the end of the Catalog 
RaisonnS of M. Dolomieu.** An English translation of this ungo- 
lar account is afterwaida hoe given. 



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NOMC II. VSSICVLAft LATA. 53] 

every step saok deep mto it. * The figure of these 
icori«e, the smallest of which are about a line, 
or somewhat |ess, in diameter, is veiy irregalan 
Krteraally thejr have the appearance of scoriae 
of iron; and when broken, are found full oif 
small caFities, which are almost all spherical, or 
nearly of that figure. They are therefore light 
and friable, two qualities which are almost 
always inseparable ikom scoriae. This great 
namber <^ cavities is an evident pro<^ 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 it» 
in sooriaceoQs particles, to various heights and 
distances, aocordiug to the respective weights of 
those particles. The most attentive eye cannot 
discover in them the smallest shorl ; either be- 
cause these stones have been perfectly fused, 
and with the lava passed into homogenous con- 
tistenoe, 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 sufieped no injury 
from the fire. When these scorim are pulverised, ^ 
they become extremely Mack; but retain the 
dryness and scabrous contexture which they had 
when entire. They abound in iron, and in con* 



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53S DOMAIN XII. VOLCAHIC. 

sequence the dust produced by pul7erising them; 
copiously adheres to the point of the magnetised 
knife j and a small piece of these scoriae wfll 
put the magnetic needle in motion at the dis* 
tance of two lines. 
BftDaofiava. ^' In the midst of this immense quantity of 
scorise, 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 were originally particles of lava gected 
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 



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KOMI II. TISICVLAR UlTK, SS3 

arose 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 and admire 
the secrets of this stupendous volcano. The sun 
likewise shining in all his splendour, seemed to 
promise that this day should crown my wishes. 
But experience taught me that the two miles 
and a half I had yet 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 i^Taof i78T. 
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 i the 



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I 



934 noMAjm xia» tolgasicu 

greatask beings w far as I was able to- obaenre^ 
about et^Meeu feet» and the least six. Its 
course is down the west side of tke aaouiitnii; 
aDid> like the other lava which flowed ia July 
n%7, it issued inmediateljr from the great crster 
of Etna. The whole niunber of the enqrtioiia ^ 
tkia moaataia of which we have aay recevd^ 
before and after the Christiaoi »ra^ k thkty;<>iie ; 
£raptioittiTomaad ten only, aa wc are imfbrmed hj Giociu^ in* 
chidiDg tbaa of which he has. given an accom^ 
have issued immedialiety Iroaa the highest drater. 
Thai which i observed may bo the eierentb, 
unless it should rather he conssteed as the saaM 
with that described bf the Sadliao iisliiniKst» 
fsioee the iattrTal between Augvst and October 
is a Tcry Acrt inlenwission ef rest for a vokaao. 
The eanse of the rarity of the emptiona which 
issue inmediately fifom the crater, compared 
with those which disgorge from the sides, seems 
easily to be assigned. The centre of this rot* 
ca»Q is pffobaUy at a great depth, and perhaps 
im ^ level with the sea. It ia therefore mmch 
more easy fiur the auitter lM}uified by the fire, 
pMt IA efenresceBce by the elastic Buids, and 
impelled oo erery side frenn the centre ta the 
circasifereace, to feree ita wajr tlieoi^h one of 
the sides of the monntaia where it ittds least 
resistaQce».aadtherelbrmactti?reat^ tbmitobe 



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HOMB IK TES1CIJZ.A& LAVA. 535 

thrown up, notwithstanding the resietance of 
gravity, from the bottom to so great a height as 
the highest crater c^ Etna. It is evideDt, there- 
fore, that the effervescence in the eruptions of 
the months of July and October 17^7, was ex- 
tijemely Tiola^t. The torrent of th^ month of 
Octdtier is; every where covered with sceiiao, 
which reaemble those ejected in the nsonth of 
Julj in their black colour, hut differ from them 
in the gieat adhesion they havie to the lava, in 
their cgcterior Tttieoua appearance, their greater 
weight, aad their hardness, which is so great 
thai they give sparks with steel almost as plen* 
iihiiy as flints. * These diflereiice% however, 
are to be attributed only to accidental combina* 
tioBs of the same substance ; the constituent 
principles of the scorise of tiiis lava not being 
different from those of the detached scorias 
BMntkmed above. Both likewise contain the 
same felspar lameUs^. 

<« '^rttts new current was however Tery difi- Difficnitietof 
€^, and eveit dangeteus^ in the passage. In 
some phees the scorisd profeeted in prominent 
aaig^es m4 points^ and in others, smrii in hollows, 
o« irteep decIivilieB ; in some, from their fragSity 
and smoothness, they resemUsd fthi» plates of 
ie«^ nA in otheia they presented vertical and 
fimrp piojefitiow. In addition to these ^f&* 



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336 DOMAIN XIU VOLCAMrC. 

culties, my guides informed me I should hare 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 fire* 
quently done at other times, how much may be 
effected in cflfficulties 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 suf» 
fers himself to be surprised by a panic fear, will 
be induced cowardly to desist from the enters 
prize he might have completed. In several 
places, it is true, the scoriae broke tinder mjr 
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 guides had like- 
wise, from its extreme heat, proved highly dis* 
agreeable ; yet at length I surmounted all these 
obstacles and reached the oppbsite 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 red- 
ness i and on applying the end of the staff which 



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NOME IK TBilCULAK LATA. 357 

I had ased as a support in this difficult jonraey^ 
to one of these, it presently smoked, and imme- 
diately after took fire. It v^as therefore indubi* 
table that this heap of ejected lava still contained 
ivithin it the active remains of fire, whicli y ere # 

more mfinifest there than in other places, W»^ 
cause those matters were there JUpUected in 
greater quantities. "^ 

^^ I had yet to encounter other obstacles. I had Cone of Etna. 
to pass that tract which may properly be called 
the cone of Etna, and which, in a right line, is 
about a mile or somewhat more in length. This 
was extremely steep, and not less rugged, from 
the accumulated scoriae which had been heaped "■:/ 

upon it in the last eruption, the pieces of which 
were neither connected together, nor attached 
' to t||[$'ground; so that frequently when I stepped 
up^on ope 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 scorias 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 



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338 DOMAIN XII. TOLCAinC. 

found the only method to avoid this inconve- 
nience and continne my journey, was to step 
only on those large pieces of scoriae which^'on 
account of their weight, remained firm ^ but the 
• ^S^^ ^f ^^^ ^^y ^^ ^^^^ more than doubled^ 

b^he circuitous windings it was nectary to 
make to fio^^uch pieces of scorisB as, from their 
large size/' ^re capable of affording a staUe 
support I employed three hours in passing, or 
^ rather dragging myself to the top of the moon* 

tain, partly from being unable to proceed in a 
right line, and partly from the steepness of the 
declivity, which obliged me to climb wilb my 
hands and feet, sweating and breathless, and 
under the necessity of stopping at intervals to 
rest, and recover my strength. How much did 
I then envy the good fortune of those who^had 
visited Etna before the irruption of 17879 when^ 
as my guides assured me, the jouaey was far 
less difficult and laborious! 

'* I was not more than a hundred and fifty 
paces distant from the vertex of the cone, and 
already beheld close to me, in aU their majesty, 
the two columns of smoke. Anxious to reach 
the borders of the stupendous gulf, I summoned 
the little strength I had remaining to make a 
last effort, when an unforeseen obstacle lor a 
moment cruelly retarded the completion of my 



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NOMB II. VESICULAR LATA* " 339 

ardent wisl^s. The vdcatiic craters, which are 
stiU bomii^ more or less, are usually surrounded 
with hot sulphureous acid steams^ which issue ^ 

from ibeir sides and rise in the air. From these ;^ 

the saonnit of Etna is not exempt; but the 
kiigest of them rose to the west, and I ww*oa 
tbe south-east side. Here likewise four or fire 
itoans of ssmoke arose from a ^rt somewhat 
lower, and through these it was necessary to 
pass; since on one side was a dreadful preci- 
pice and on tbe other so steep a dedivity, that 
I and my companion, from weakness and fatigue, 
irete miable to ascend it; end it was with the 
utmost difficulty that our two guides mad^ their 
way up it, notwithstanding they were so much 
accustomed to such laborious expeditions. We 
coBlhroed our journey, therefore, through the 
midst of the ?apours ; but, though we ran as fast 
as the ground and bur strength would permit, the 
Bulpfaureous rteams with which they were load** 
ed were extremely oSensire and prejudicial to 
reqmatiou, aiid afieeted me in particular so 
much, that for same moments I was deprived of 
Mise; and found, by eixperience, how danger^ 
ous aa undertaking it is to risit volcanic regions 
inferted by such vapours. 

^ Having passed this place, and recovered by Cntcr. 
degrees my former presence of mind, in less than 

z 2 



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y . r. 

54Q ^ DOUXVK XII. TOLCAHie* 

an honr I arrived at the utmost summit of l^a, 
"^ and began to discover the edges of the crat^ ^ 
H when our guides, who had preceded me at some 

dktanee, turned back> and hastening towards 
me, 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 ^ding my labours 
and fat;jigue 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 perceiy^ 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 hs^l undergone in my jour* 
ney. I viewed with astonishment the configu* 
ration of the borders, the internal sides, the form 
of its immense cavern, its bottom, aji apertwe 
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 shall 
now proceed to give some description of it, 
though it will pnly be possible to present the 
reader with a very feeble image, as the sight 



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v' ^^ 







AK £ATA; 


J4l ' 



. aloii^ can enable him to fiirm ideas at all ade- 
qui^e to objects so grand and astonishing. 

*• Tlie upper edges of the crater^ to judge by 
the ejre, are about a mile and a half in circuit, 
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 enojrmous 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 south«east, on which side I was,. they 
are almost perpendicular. Notwithstanding this 
irregularity, however, they, form a kind of fun- 
nel, large at the toj^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 
first 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 



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*>.< 






34s OOMAIK XII. TOLCAinC. 

place where I stood, a circular apertnre^^afl 
visible, apparently about five poles in diameker, 
from which issued 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, firom the 
action of a light wind, and, when it had risen 
higher, dilated into an extended but thin vo- 
lume. This smoke was white> and being im- 
pelled to the side opposite to that in which I 
was, did not prevent my^seeing within the aper« 
ture; in which I can afiii^m I very distinctly 
perceived a liquid ignited matter, which conti- 
nually 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 gul£ 

^' 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 



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•4? 



noum II. VBsicvLAa lava. 343 



I had d^ached from the edges of the crater, 

bounding down the side, in a few moments fell 

on the bottom, and those which enterecl into the 

aperture, and struck the liquid lava, produced a 

found similar to that they would have occasion* 

ed had they fallen into a thick tenacious paste. 

Every stone I thus threw, struck against and 

loosaied others in its passage, which fell with it, 

and in like manner struck and detached others 

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 from 

that I have before described. The bottom can* 

not therefore be considered only a thin crust; 

nuce, were it not thick and s<did, it must have 

been broken by stones so heavy falling from so 

great a height 

'^ To satisfy one emotion of curiosity, is fre* 
q^ientiy to excite another. I had at first ap* 
proached this volcano with a kind of superstitious 
awe. The histories of every age, the relations 
of traveller, the universal voice of Europe, had 
all contrUmted to inspire those who should ad- 
venture to vi^t it with dread : but as at this 
time it seemed to have laid aside its terrors, and 
was in a state of perfect calmness and tranquil- 
lity, I was encouraged to become more familiar, 



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r 



344 J»OMAIN XII. ▼QZ.CAMXe. 



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 
than the others ; and I therefore conceived that 
this might serve me as a ladder to descend to 
the bottom, where I might have added to the 
observations I 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 ^bout 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 pestilen- 
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 un- 
expected eruptions. 



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NOHB II. TB8XCULAR LAV4. ' 345 

<^ We have seea above that there wbr9' two Second enter, 
columns of smoke arising from Etna. It is 4:0 
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 it 
the second, from which ascends a lesser column 
of smoke. The second crater is smaller by 
about the one*balf than-Slhat I have already de* 
scribed; and the one is separatied 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, on accomit of the numerous 
and thick streams of smoke by which it was 
surrounded. This, however, was no great dis» 
i^pointment, after having seen and examined 
the principal crater, which is that whence several ^ ^ 
currents of iava. had issued in 1787. I ought 
certainly to consider myself as extremely for* 
tunate, in bemg able to gratify my curiosity with 
80 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 



y 



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346 DOMAIN ZXI. yOLCANia 

which tK^ey had a clear and undisturbed view of 
th^ internal parts of that immense gulf. After 
my return to Catania, the Chevalier Gioeni like- 
wise declared to me that in his different excur* 
aioAs to that mountain he bad never had a good 
fortune siniilar 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 whea they had 
arrived at the foot of the cone, where they had 
proposed to begin their operations, they were 
obliged to return back, from the obstacles they 
met with, which, to say the truth, are commonly 
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 
Mnge along the sides. The winds likewise fre« 
> quently blow with such violence, that persons 
can scarcely keep their feet, not td 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 th6 streams of sulphureous vapour which 
rise on the sides, and the thick clouds of sul- 
phureous smoke w|iich burst forth from the 



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NOtfB II. TB8ICULAK LAVA. 34/ 

mouth of the volcano, even when not in a state 
of a^tation. 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, 
hov^ever, 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 the atmosphere not incommodious, the ther> 
mometer standing at seven degrees above the 
freezing point (48* of Fahrenheit), and the wind 
&vouring my design, by driving the smoke of 
the crater from nse, 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 
might 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 



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348 DOMAIM ZII. VOLCAVIC* 

* ^' comparison will show the great changes whichf 
have takeo place in this volcano withiq %e 
space of twenty years ; that is, from the^ime 
RiedcseL when It was visited by Baron Riedesel in I767» 
to that of my journey in 1788. At the time 
when that traveller made his observations, the 
crater was enlarged towards the east, with an 
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 y pro* 
bably because he had not seen it, having been, 
as I imagine, prevented by the quantity of 
smoke which he tells ns continually ascended 
from it. 

" It is worthy of notice, however, that at that 
time there was not at the bottom of the crater 
the hard, flat surface I have described ; since the 
stones thrown into it did not return the smallest 
sound* Within the gulf itself was beard 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 Jl>egin 
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 



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^\ KOMB It. TB81CULAK hktk. 349 

., the liquid iSva of Etna, either at the time when 
BafoD Riedesel visited the crater, or v^hen I ^ 

' observed it in a state of slight commotion withiu 
the gulf, it must immediately.^ have swelled in 
every part, beating violently against the si^^^es of 

,^ the caverns in which it was imprisoned, tfauK^*^ 

^red among the deep cavities, .and, 'bursting 

forth through the sides, have poured out a river 

1^ of fire ; or should, its violence have been thei^ 
resisted, it would have rushed up within thi» 
crater, until it overflowed its brink, and deluged 
the sides of the mountain with its torrents. 

'* Sir William Hamilton, on the 26th of Octo- 
ber, 1769> ari^ed 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 
lower parts of the crater, being prevented by 
the. great quantity of smoke which^ssued 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 
until it ended in a point; and that this funnel 
was incrusted over with salt and sulphur. The 
crater was two miles and ahalf in circumference* 
** From the time, therefore of the journey of 
Baron Riedesel to that of Sir William Hatniiton, 



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3^0 , DOIMiK XII. VOLCANIC. 

the crater must have undergone gr^at changes 
in its structure; since if the stones that were 
thrown into it gave no indications to the ear 
that they struck, against any solid body^ it is 
manifest that there must then have^been an 
)aKyss as well as a funnel; and as the funael 
terminated in a point when it was observed b^ 
Sir William Hamilton, it is evident that the flal 
bottom I have described, and which was about 
two thirds of a mile in circuit, did not then 
exist 

<< The internal sides of the crater. Sir William 
tdls us, were covered with a crust of salt and 
sulphur; but he does not specifj^the nature of 
the former; and though the presence of the lat- 
ter is not improbable, he might have been led 
into a mistake by the yellow colour, and have 
taken the muriate of anmioniac (sal ammoniac) 
tor sulphur, as I did before I examined it. Sir 
William has not told us that he 'made any 
examination at all ; and it is probable that he 
judged only from the appearance it presented to 
his eye. 

^^ He observes, lastly, that the crater was two 
miles and a half in circumference ; an estimate 
which may be made to agree with mine by ne« 
glecting the partition which separates the greater 
crater from the less> and considering them both 



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> 



tfOUB II. TBSICUURULATA. 



xX;f;LATA. 351 ^ 



SB one. The sum of the two circumferences^ 
according to the estimate I have given^ woqU 
then greatly difier from the measure of Sir Wil- 
liam Hamilton. Nothing likewi^ c^n be more. 
probable^ than that among the various changes 
&mt have happened to Etna, this partition/bjr 
which the grieat crater is divided into tjK> parts, 
has been produced. 

" Omitting the observations of Mr. Brydone, 
that ^^ thetreniendous gulf of Etna, so celebrated 
in all ages, has been looked upon as the terror 
both of Uiis and another liiei that it inspires 
such awe and horror, that it is not surprising 
that it has been considered as the place of (he 
damned;*' and other similar philosophical re* 
flections which he has employed ; and confining 
ourselves to what he actually saw on tne 29th 
of M^r, l!N[0, we learn from him that ^< the 
crattr was Iten a circle of about three miles and 
a half in circumference; that it went shelving 
down on each side, and formed a regular hoi* 
low> fike a vast amphitheatre ; and that a great 
moDth opened near the centre*. 

'^ From the time of the journey of Sir William 
Hamiltoii therefore, to that of the visit of Bry* 
done, that is to say, within the short space of a 

« Bfyaotie*ti:buithmsli$i^v4Miata,vd.i >9^> 1«6. 



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year^ various changes bad happened to this vol- 
qano, by the enlargement of its crater> aad a 
spacious ape^ure formed in its bottom. 
Borch. « Count Borch appears to have wished to cx-t 
^f ceed the three other travellers in brevity, rela^ 

tive to this subject; since he only tells us tiiat 
he arri^ at the mountain on the I6th of De- 
cember 1776, and that the crater of Etoa is 
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- 
i^tance not noticed by others, ^Sir William Ha- 
milton even affirming that the summit of the 
mquntain is single; whence we may coadade 
that one of these summits has. been produced 
since the time of the journey of Brydooc^ in 
1770. 

<' On comparing the above-cited QJ^rvations, 
made within the space of twenty*cMie yeaqib we 
may perceive how many changes have taken 
place in Etna during that interval; and aa 
within that time the mountain has suffered only 
two violent convulsions, in the eruptions of 1781 
and 1787, it is evident that even in the state of 
apparent inaction, it still internally exerts its 
force. 
o^ffOie. « To these observations it may likewise not 
be without utility to add those of M. D'Orville. 



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p/t 




I 



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354 • ooiiiav xix» tolganic. 

volcano. . It is an uiiiexting>tti$Ised: forge, vrhicfa 
in proportion to the violence of tb^ Bre, to the 
nature of the fossil maS;ter oh which' it msts, lAsd 
of the elasUc flntds v^hich.nxge and set it m mo- 
tion, produces, destroy^; and re-prodttoes irarioiis 
forms. The usual and ikUmral figure jof (he s«ii<- 
mit of a volcanic mountain, is tbutof oA inverts 
ed concave cone within, andjohe soRd and erect 
without; and such 9; coofiguratidn^ ineountried 
whieh ak*e bo longer in ra state of oonfli^atioo, 
is one of tiie most certain.ihdicaiioiis'orthe exn 
istenrca of an ancient volcanoL Thistoone^ baww 
ever, is liable to very great changes; 'according 
to the greater or less fury of the volcano, and the 
quantity, and quality of the matters ejected; Its 
internal part, fromntore than. one cause, is ex«> 
pos^cto. Qoittinnal vtdlence: and change. The 
prodigious cavities of the mountain niake it 
almost appear suspended in the air* It may 
easily therefore give way^ and fall io^ especidly 
on the violent impulse of new matters, which etb* 
deavour to force a passage through, the upper- 
part s in, consequence of which the inveftedrcone 
may, according to circumstances^ ipr9S6ttit the 
appearance of an aperture, or whif^KMol^ or ci 
gulf. Should the liquid lava pass tfaroa^ th^ 
aperture, and continue there some time, its 
superficies by the contect of the cold air losing 



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NOMB II. ITBSIGVLAR LAVA. SSS 

its heat gradually, would congeal and form a 
crust or solid plane ; and should the fluid lara' 
beneath, afterwards act forcibly on this crust, it 
might burst it, or make a passage where it found 
least resistance ;. in which case the melted lara* 
would occupy that aperture. Should then the 
crust, instead of ascending in a single body, be 
forced up in small fragments, these cooled in the 
air, wouFdiaU down in immense quantities Within 
the crater; and, firom the effect of the laws> 
of gravity; must accumulate in the figm^e of a 
cone. These theoretical conjectures, if they do 
not perfectly explain, may at least enable us to 
conceire the nature of the causes, which have 
produced the difference of appearance observed 
at different times in the crater of Etna. 

<< It is much to be regretted that we have no Oumge^. 
history of Etna; wViich, did we possess it, must 
greatly contribute to elucidate the theory of 
volcanoes, and the causes of the various changes 
which have taken place at different times, in the 
summit of this mountain. That suOh changes, 
have happened, is evident from the few but va- 
luable notices concerning^ 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, stiabo. &c, 

2 A S 



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9A6 domain XII, rOLCANIC. 

though he was not himself an ocular witness, 
but relied on the information of others, who had 
visited £tna» and from whom he received the 
account, * That the summit was a level plain of 
about twenty stadia in circumference, surround- 
ed by 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. 

Hcinbo. ** 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 obiervation agreed with that of D'OrvHIe, mentioned 
above. I find likewise that similar mounta have flometimes been 
thrown up within the crater of VesuTius. See De BoMif hi^ria di 
varii incemUi del VesuvioJ* 

t " In Etnse vertlce hiatus duo sunt, ciateres nominal!, per quos 
eniciatos erumpit vapor. Cap. xi. 



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NOICB II. inSieVLAR LAVA. ^7 

tlm>wn ham a sitng. The extreme vidence of 

the wind, and tbe exhaling fiimes, prevented 

Ikun fiom approaoliing the upper crater. The 

lower he found to be formed like an immense 

pity and surrounded with a plain of no great 

extent^ which was so hot that he could not bear 

Ins 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 

Gataoia, from a monk, who, he assures us, was 

a man deserving credit, and well acquainted 

with S]K:h subjects. He informed him that this 

crater was situated on the highest part of the 

summit of Etna; that it was about three miles 

in circumference; formed like a funnel; and 

tiiat 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 

nndisturbed, he had observed it without danger 

or difficulty. 

^ In tfaetime of Fazello, however, who visited FneOo. 
Etna after Cardinal Bembo, there were no longer 
two craters, but only one ; the circumference of 



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rnlttdBk^'^sl^inhnM.UBiWn^ It had 

the umml (offm<of:tte Aiiindl,>eintte^ fice and 
thick flookike;. but ati!iqterKab>iiva8: oahn, .and 
migbttbe approached; at whcch^limcB asobter* 
nmeoua.ndise w&9 beard, ahd' a; saand like that 
of the bdiling of an imflneoae ^dron od avast 
£re. These, obaeryationfi were made by him ia 
1541, and 1544 ; in both which ye«r» the orater 
appeiirs to iiave beein single*. . 

'f These hw catatiobs .appebi; to me sufficisnt 
iosho^w 'wbat cfa|ki\geB h^iie >takeir place in *the 
saminit of £taiL,i j;datJne;:tD -the. niunber, the 
form, :Wd 'th^ t^igm of iU ccatens^^acoocding to, 
the dkf&fOfit ;6Sbott 'af:ito>cboflagratioii6 at;di& 
ferept Mme$* B«t then^ ifi ;ltlDevito aoKKdiar 
alt^r^ttioniWhijeh'jshbUldnof^bq piumd^ummticed, 
4[€ScribeAby tw^^ writerswlio thedisc}«rte:QhEierved 
4t^ J^^^eljl^ i»nd! BofeUi; d hman.lthe ifaiiing in 
afi(({jl; abfOfpttoB of «lie exf^em&aimunitiof jLtoa 
jfiri^iQ, ite cr^teL Thej(fofwec oifirthe aboi^ 
fipfenf^otibdamhors irefotes t^t inihi^ timeitbm 
Af^e^ in.lhe Inonth iof ttie.craUer^ia Uttie faitH 
4^]«|0dj aa levery: did?, ivluch ibnde^ lAe vei^n 
of the mountain; and which, in a tenSUebhip^ 
^Crtix fell inte^ and Was Ibitried in tbe ^f» thus 



• Fazcl,5ic. 



. 1- 



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jufrnm-n. VBBiooirUi lava. 55g 

etilafghig «hei ^ifMeir, axi^d diminishiiig the^^i^bt 
of the tnoiintain. THis hill itself bad been pro* 
doced by a fomer eruption in 1444*. 

^ Iiiiike nia;on^r9 BoreUijnforois us that in 
the conflagration of 1^699 the snntinnt' of Etna^ 
^Hiieh ras6 like sL tower to a great heigbl! above 
the pBift Whi^h is levels was swallowed up in the 
<fe*p giilff. 

^^ I have already said, that when I visited 
£tna, its summit was divided into two points, or 
littik fountains, one of which rose a quarter of 
a mile above the other. I should not be sur<» 
prised were I to hear that in some new and 
fiferd^ eraption, the highest of these had fidlen 
in, "andthe two cratet^ became one of much 
larger dmiensifohs. We know that> the summit 
ofVeimvins has sometimes faltett down iii the 
same manner; nor does it appear difficult to 
assign ^the cause. ' It seems to admit of no doubt 
tha<^the highest patts of-Etna, and other nionn* 
taiAs which vomit fire frotii thdr stfnimits, hare 
theit fettndations on ^e sidel of the crater; 
which ^tend to an imnfense depth* In any 
violeBt earthquake therefore, or inipetuoud shock 
of the lava endeaivburing to force a passage, it 
may easily be imagined that those foundation^ 

• Ubi sup. Borelli Hist. Inc. Mtom, 1669^ 4to. 
f Ubi sup. 



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9§D • ' OOMAIN Xf I. VOX.CU.KIC 

mutt.be tiora up and br<dp8ii,awa]r, and the sboi- 
mit 0^ the volcano fall andibe Iqsjt in the guUL 

*' These .dilapidations have not, however^ from 
timie tmineniorial, produced • any sensible dimi- 
nution of the height of the suinniit of Etna ; 
since the loisses occa^oned by some enipfcioMs 
are repajr^ by others which follow. This may 
be inferred from a phenomenon usually ioaepap 
rabie fr<im the summit of Etna» though^ by rare 
accident, not observably lat tbus time of my jour* 
pey ; I mean the ice apd snQiv with which it is 
covered. Had any con^d^rftble deqrea^of the 
height of the mountain ta(ken<pIa^oe, in eonae- 
quence of the smnmit repeatedly faUiiigin, in 
lee and maw. former ag^ the ice and snow wpuld not cer- 
tainly, :in:a diduite so mild, have cont^oied to 
envelop the top of the mountain as they now.do, 
even during the heats of summer. But this con- 
tinual residence of the snow and ice jO|i.£tna 
b^ been celebrated by all antiquity; fqr. near 
observation was not neces^ry to ascertain this 
phenomenon, since it is distipctly appairent at 
the distance of a hundred ,miles. Adscendit ca 
regie (says Fazello, speaking of the upper r^g^n 
0f Etne) passMummiUia fere xiiy gtue per hyemem 
iota nivibtis obsita extremisqtle fr^oribus riget : 
per astatem quoque nulla sui parte nee cavitie nee 
gelu caret: quod equidem admirationC; 4ignum 



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•eooanti. 



€$$; cwn vertef tncmdia prnpe sempUermtJu^i 
fioMmarum etudatiime inter. niaes ipsas .pariat^ 
ermtriat, ae cantinuet * Tins negion extends 
nearly twelve miles; and, even. in sunlnner, ii 
almost perpetually covered with snow, and ex- 
tremely cold ; which is the more wonderfnl as 
the summit coutinuaJly produces, nourishes, and 
pours forth flames amid the ice and snow with 
ivhich it is enveloped/ * 

** Solinus and Siltus Italicus give the saikie de* Aadent 
scription. The former says, Mirum est quod in 
ilia ferventis natura peroicacia mixtas ignibus 
(JStna) nioes profert : et licet vastis exundet in* 
cendiis^ aprica canitie perpetuo brumalem detinet 
faciem^. « Etna, in a wonderful manner, ex- 
hibits snows mixed with fires; and retains every 
appearance of the severest winter amid her vast 
conflagrations/ 

<' Siitus Italicus has the following lines : 

' Summo cana jugo cohibet (mirabile dictu) 
Yicinam flammu glaciem, sternoque rigoie 
Aidentes boneot aoopuli ; itat vertice cebt 
CoUis hyemsy calidaque nlyem tegit atra favillaf.* 

' Where baming Etna, towering, threats the skies, 
'Mid flames and ice the lofty rocks arise; 
The file amid etemal winter gkws» 
And the warm ashes hide the hoary snows.* 

• Cap. xi. * t Lib* w. 



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1J5S ^noMAnr xit. Tovtktne.' 

AMittnced^'haver^qiipted^spoet^ I will chetm 
Dthero; 'datidianmndi^iiHbr^ at it i^scflhaiiJl 
Ijitetfixtent thnfa poetry heitemikit'es^reas trarii^ 
and notrfiction. 

, ' Sed quamvis nimio fervens exuhecet aesUi, 
* ' Scit nivibus servare fidem : pariterque favillis 
' , ;2>iifatotC^lad^;'tMidflfccarav(i(poris, 
- AccaDD defeaM gelu« fa«a(M^ iideU 
Lambit contiguas innoxia Bamma pruioaa*.' 

. ' Amid ^e^fiies aQQVdutetrs^««aow, 

And ffogt .rciains where .^urning ayhw j^bw j 
O'er ice cterDal sweep th' inactive flames^ 
And' winter, spite of fire, the region claims.* 

. ^^ Thu5 th^, XMiB poet; but. tbe Gfeek )m 
givea us a piiOture of Etna rDWchi more -i^blljr 
coloureds repr^ntiog it not looly w the eternal 
abode^ of snows^ but as the columa of heiMiept'to 
express its astonishing height 

Ni^os^a-' A<rva if aver Bg 



' ' Snowy Etna, nurse of endless frott, 
"The mighty prop of heaven.' 

It is to be remarked that Fipfdar Uvedl:five ban- 
dred years befone^theXDbristiim^ra. 

• Claud, de Rapt. Pro. 
t Find. Pyth. Od. i. 



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:<* I tBow mtorn fcom Ibis digreBSion, tuFlildl, smoke. 
.thov^ iiot inAeed v^ty shorty appetas to nHe 
perfisotly* i^ppiropiriate toi l£e: sufojeDt;. rad ^o- 
ceed to fBsiraiii iny iiak^rat£?e. I shattifiivt^pwk 
bkiefljT 6f a phenom^iioft relative to the «m6)ce 
which arises from the crater of Btna^ and ^bieh 
was seen differoidy by Mr. Brfdone^ Gonnt 
Borciiy. andmyBelf. Mr. Biydone t^ls vsr^tbat 
^^ from many places of the crater iisue volames 
of sulphmnedus smbke^ivhEck being much boaivier 
fthan the circumambienUi air^ instead of) rising in 
ity .as fimoke generally does, imoiediateiy 0Xk its 
Jetting out of' the crater,. ^rcJis do^n ^the aide of 
ibe-moontfllialike-a torrent, tvHicoming tothat 
'part .Q£.)thii} ainldspherd ;bf itbe same «peoific 
gravity with itself, it shoot&liff horizonibaUy, and 
4bnxfe';a la^ge tssick hi the air, according to the 
•di]3eQtio4(of:the i^nd." . 

. . ^^QmAeHSBbinryf th^iannfie wbeii 'seen by 
'Count! ftiteb,,fht (the ictt^rvafeiwhen the air was 
^ipv "aitoseii^tperiilBndiciilarly, to a gneat height, 
^aa|d:afteE#aiHls'ieU,'like: white fleeces, on the top 
^ofitlldxniohntaiD. I shall : not prcssume' to d<mbt 
ittbtose:^tw6i£utts, though i oteenr^ neither of 
•them. The^ two colonmi? of smoke whtch I "saw, 
'thon^betyt somewhat frohiftbe pei*pi^)dicniar 
%ctiie ) wiikd,' asetnded -with the ttsual : ptmfarpti- 



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564 BOM AtN XU. TOftCAKIC. 

tilde .of ordinary smoke (a certain proof that it 
was ooasiderably lighter than die ambient air), 
and, when 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 diffeirent at different times, but also 
from the diversity of the smoke, which may be 
sometimes lighter and sometimes heavier than 
.the air that surroiinds 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 
that 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- 
vellers I have before cited, were likewise difi^rent. 
Sir WilUam Hamilton tells us, that the thinness 
of that fluid occasioned a difficulty oi respira- 
tion; and Count Borch appears to haveexpe- 
rienoed a still greater inconvenience of that kind, 
since he says, *' The rarity of the air on this 
mountain is extremely sensible, and ahnost ren- 
ders that fluid unfit for respiration." On the 
<iontraryi Baron Riedesel felt no such effect^ as 



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NOHt II. ▼SSlCin.Aft LATA. jj^ 

far at least as we can judge from his own wofds* 
^^ I did not perceive, as several travellers have 
asserted, that the air here is so thinf 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 
no 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 
curiosity, we went round and examined different 
parts of the edges of the crater. The same is 
affirmed by Borelli : JEque bene respiratio in 
cacumine JEtna ahsolvilur^ ac in locis subjectis 
campesiribtis. — * 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 



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hi^travelaamong the Alps.; TheobseriwtioQihe 
haft made; appeab to-me to.expHuB.the caose of- 
these diffteeot.ateoants', rdafive.to the effisct of 
the aif , oa> ihe top , of Etoa. Whfla the het^bfr 
abo?6 /the live! of the sea was two timosftod 
fonr Jiundred andi fifty poles^ or-nariy such^ 
which, he found to be that of Mont 'Hanc^ every 
individual felt mdrei or less inconrenieQce from 
% the rarefaction of the air>. as happened to him^ 
self and nineteen persons who accompanied him^ 
when ,in August • 1787 he ascended that moon* 
tain. : But when the elevation was much'leB% a& 
for example nineteeti hundred pdes^ some of 
these< persons felt no difficulty, among whom 
was thjanaturatiat; though he confesses that fe 
began to dcperience inconvenienoe. as faeascend<4 
ed higher. We have not indeed any oertai^ 
obsevvalions relative to the exact height of Etna^ 
as is sufficiently proved by the different esti- 
mates given by diflBenent natursdists; Signor 
Dangios, however, astronomer at Malta, in the 
year 1787> measured the height of this moun** 
tain, by a geometridal methbd, and the pubUc 
atoioasly expects the! results, which will sabV 
factorify solve this important problem. In thai 
meaivtin;!^, from c^mparingthemeasm^s Utherta 
^pigned, Jih$ «levatton of EtiiajEtboretbe levd^ 



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oi the sea is probably samewhafc less than. n\m<A 
teen hundfed pole^. Hence we understasuft 
why respkatJon, in many persons^ is not incooi^^ 
modedi whiles the contrary . happens to otheisy 
SHH^rding to thedifferentvatrengtli; and hdodt ofi 
bodyof diffetent kidwidaols; 

'' After havbig^ tot two< jbciurB^ jndoigied xaji Vi^ from 
ay«b with' i yfcw of (he intaoior* of .the cratery 
l^at iv XQ tbe dontemplattoa of a spectacle 
wbi^h io ite kind/ and in the. present, agey is 
without a paralJel.in ;tbe voridi I turned themr 
to anothe/ispeae, which js lifaewise. unequaliadi 
ht (he multiplicil^^itbe beauty, aodithe vacietyf 
of the ohjectsc it ppesente. In. faot, there isi: 
pi^rhaps, no ele¥9ft^ region oik the whole gbbe 
which offersy at.ode.yiew> so ample an ^Ltontio^ 
sea jBipd land as the smonyt of £tna»' The firah 
of the stthliide objects which ij^ presents;^ k the 
immiense mass of its, own colossal body. Wheot 
in the conntry. below it» near CataDia> we raise 
Qur eyes to this sofvereign q£ the mountains>^ we 
certainly 3tirT^ it with admiration^ as it. rises 
ijaige^wally, and lifts its lofty head abore the 
doud^; aiidrwith:a.«kind:of geometric.glancejwe 
eslumte its height fiwn thie^,bQae.to.thejiuiinttt(! 

• The height of Etna is generally estimated at 11,000 feet abore 
the sea. Ferrara seems to estimate it at little more than 9^X)0; 
1610 /ef« (p. 141). 0OH»iitinteaQtlieFrttich'/ot>ef-^R . 



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96s ixmAtir xn. tolcakic 

but we only see it in profile. Very different is 
the appearance it presents, viewed frona its 
towering top, when the whole of its enormoos 
bulk is subjected to the eye. The first part, and 
the nearest the observer, is the upper r^on, 
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 
xone, 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. Lartly, 
the eye contemplates with admiration the lower 
region, which, from its violent heat, may claim 
the appellation of the torrid zone; the most 



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11/' TB8I0U£Aft LATA. 36^ 

of the three, adorned with elegant 
wiUaft aod castles, yerdaikt hills, and flowery 
£kMh Mid terminated by the extensive coast; 
where, to the south, stands the beantifol city of 
CtlMiia, to which the waves of the neighbouring 
flea serve as a mirror. 

** Bat not only do we discover, from this 
astoniridng elevation, the entire massy body of 
MoQBt EUia; but the whole of the island of 
ftoily, with all its noble cities, lofty hills, exten- 
sife plains, and meandering rivers. In the in<» 
Afltioct distance we perceive Malta ; but have a 
dear view of the environs of Messina, and the 
greater part of Calabria; while Lipari, the 
fiiniiiig Volcano, the blazing Stromboli, and the^ 
other Eolian iides, appear immediately under our 
faet» and seem as ifi on stooping down, we might 
tooeh them with the finger. 

*« Another object, no less superb and majestic, 
the far-stretching surface of the jiubjacent 
, which surrounded me, and led my eye to an 
distance, till it seemed gradually to 
aiingle with the heavens. 

^ Seated in the midst of this theatre of the 
wonders of nature, I felt an indescribable plea- 
iufe from the multiplicity and beauty of the ob- 
jects I surveyed ; and a kind of internal satis- 
frctioh and exultation of heart The sun was 
VOL. IX. * » 



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370 mocASir Kir. T6ijaa«& 

idhrftiicing to the iDeridim, unobBCiH-ed bf tint 
imaUe9t cioud, and RteunKir^i therwonetec 
$feood ID tiie t&atik degree above the freeaisg 
point. I was therefore io that temperatiine 
which 16 moBt friendly to man ; and the reined 
air I breathed, as if it had been enlareiyTilaiy 
oommnnicated a vigour and agility to my Imbs, 
and an actirity and life to nty iiktas^ which ap» 
peared to be of a celestial Bature." 
CftTeiiii. The corrents of lava sometima oontain ca^nem 
oi a very conadeFafale extaait. In Icebad thejr 
afibrd recestes &nr the flocks of shQep^. Dclo* 
mieu has descrSied a very remaifcaUe one in an 
island near Sicily; and \fe also fband swie in 
^he proxijtnity of Etna, sometimes 40 feet m 
height and M in breaJ^^ the walb and lauh 
'^ being m regular as if they wem vcris of aitf. 

They are nuinerous; and scme^ as he asserki^ 
many leagwes hi leagtfi. His eSplaJoation is^ 
that the surfhce of the lava forming a crust, is 
./- sometimes tf rested by impediments, while the 

under current continues to flow; so that upon 
its complete elapse, the space nemains void* 
Thus bridges, of sctne miles of breadth or length, 
are found on the Missouri, in North Aranrica: 

• Von TroU Voy. d'Islandc, Parb, 1781, the best edition revised 
j^ by die attthor. 

t Li|Muri.-^taa4 S9I. 



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the floalKig tnees being atopped by wme obite* 
^cle. Similar caverns in Iceland, especially near . 
Hecla, are described by Vo» Ttwi. 

The vesicular lava, like the eocapact* mtkj be 
divided into two principal kinds: those with a 
hue of siderite, and those witb a base of feUte, 

HYFONOME I. OP SIDEBI1*B. 

This is the most common of all the lavas, and 
covers the sides and skirts of every volcano*. 
The colour is black or grey, derived from the 
melted sijlerite. The vesicles are generally romid; 
the larger, of two or three lines in diameter, being 
interspersed with many^smalkr poi^a. It is often 
spotted with whke spa^les. of felspar; and the 
vesicles sometimes contaia crystals of the same ^ 

substance, and^ sometimes of zeolite. Those of 
Vesuvius, oi^ itself an extinct volcanoi, laid of 
the extinct volcanoes of Italy in a more northeni 
direction^ often contain leaoite, a white stone cry$«- 
taUised like a garnet This last may he said to 
form the base of some lavas, oooaparativeiy more 
abundant in cabuiets tiitn in satocef. 

Homogenous vesicukir lava^ ikom Etna, Vt$m^ 

• 

* Saussure, $ 178^ concludes that his roche dfi cvne forms the 
base <)raa the Uadt Ibvm. 

t Dol. Etna, 441, says that pyrites are fiumfi4 in^eaomppsed lara, -/ 
in the humid way, ))f the union of th^ iron with the aulphur. 

2 b2 



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^^2 DOMAIN XII. VOLCAHIC. 

vius, the Isle of Bourbon, the Puy-de-Domc, 
&c. 

The same, with spangles of felspar. 

Vesicular lava of a violet colour," from tiic extinct 
volcanoes of Provence : see Saussure, § 1 485, 1 495. 

The other kinds are sufficiently remarkable to 
form regular subdivisions. 

Micronome 1. With Leucite. 
Lava, with unimpaired leucite, from Vesuvius. 
The same, from Albano near Rome. 
The same, with decomposed leucite, from tbe 
same places*. 

Micronome 2. With Oolite. 

Black vesicular lava, with fibrous zeolite. 

According to Dolomieu, this is sometimes co- 
^ Xunmar. 

'^ A porous black lava, the pore^[i>eiog exactly 
round, and one or two lines in diameter; distant 
from each other more than six lines, and some- 
^ times one or two inches ; the interior of the spne* 

rical cavities being blue, while they conunooly 
c6ntaiil zeolite and calcareous spar. This lava i^ 
crystallised in prismatic columns, more or less 
regular, in the mountains of Trezza and of thf 
castle of Jaci."t Is not this an original rock? 

J •See Volcanic Intrites. . 

f t Etna^ 303. Jaci is the Ad of Fcrranu 



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HOMB in. INDUBATBJO 1III0. 37.S 

IP 

Mieroname 3. With Olivine, or Volcanic 
.Chrysolite. 

These lavas are remarkable, as the same sub- 
stance is found in basalt, and in the native iron of 
Siberia and South America. 



HTFONOMS II. VESICULAR LAVA WTTH A BA8B OF 
FBLSITB. 

In this kind the vesicles are generally elongated, 
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. 

, Micronome 1. Felsite lava, with crystals of 
siderite. > 



Micronome 2. The same, with mica. 



NOMEHI. INDURATED MUD, 



\ 



The American volcanoes chiefly devolve tor^ 
rents of mud, which seems to be strongly im- 
pregnated with iron. Torrents of this kind have 
also been said to occur in the eruptions of Etna, 



TOlCMKMI. 



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974 



MMW Xtl. VOLOAMKb 



and erf n of Vesuvius- Yet no writer has nen- 
tioned with precisiorf what form this tDod as- 
sumes after desiccation. Brocbant indeed^ who 
has borrowed his arrangement of the T^^lcanic 
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 still 
more striking, vast numbers of fish, so as some- 
times to infect the air with putrefaction. These 
fish appear to be little injured, and are the same 
with those found in the rivulets at the bottom of 
the volcanoes, being ^pimelodes silurus^ 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 4eery sources ; facts 
which tend to confirm the theory of volcanoes 
above hinted. , ^ 

^ate^ writes spectdtty mention that the muddy 
eruptions become fertile clay, and are very pro- 
ductive ; while tvito can never be regarded as a 
productive soil. If the muddy eruptions be 

* Thii is Ae Italian and classical oxthogpnipfaj. Ti^a awy he 
Keaerved tot depositions merely aqueous. 



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MMiigljr impr^Dafted witii iroQ^ they might, on 
Patrin's theory, become basaltin ; or, if mingled 
with felspar, a clay porphyry. But thig curious 
avhfed muat remain for future investigation^. 

It was supposed that Etna* during the enip- Often melted 
tioD of 175^9 had poured out a torrent of mud; 
Vttt Ferrara has shown that it was only snow and 
ice/melted by the lara ; and he gives a singular 
iastanoe of the lava having attacked a mass of 
ice, which it partially mdted, and -left only a 
|Mle in the midst, which stood for ^me time like 
a superb palace of crystal, y iloa also mentions 
% torrent of melted snow, which issued from the 
volcano of Cargaraso in South Americaf. The 
water volcano, as it is called, of Goatimala pro- 
bably ejects mud ; and Ferrara regards Maca- 
kiba as bdonging \c that system of volcanic 

* Mr. J«iMion« (Oeo9». 353»Nolai,) my the mud of the Aioe* 
rican volcanoes is called Kalh fay the Spaniards^ aoA Muya by the 
Indians. For this, and s^e other parts of his Note, he has ad- 
uoced no antnori^ \ and niey seen borrowed^ as ns^aly frooi somo 
iBMCwate Gennan writer. Hs adds^ that this mod is of « blackish 
brown colotur, earthy, and not very c^erent. There are traces of 
glassy felspar ; but none of sulphur or^^tes. Some kinds are med 
as fiiel, and emit a strong heat, without ilaanc. Klaproth^s analytu, 
fay tlus Kxxmot, yielded chiefly silex and ngiU with eaibonic aoid» 
bydsogen gaa» amonia, ooal, limey oxyd of iron, and natron. I can- 
not find it in Klaproth*s works. 

t Ferrara, l65. Ulloa, i. 267^ falsely quoted b^rdinaire as a 
volcano of mud. 



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376 OOM AUI XU* VOLCMrXQ. 

he«t wbiph influences Sicily and the neig hb o r 
ing isle8*« 

His account of the remarkable eraptioB of 
tUs muddy Tol<;ano in 1777 is subjoined^ as pre-. 
senting new and singular circumstances. 
Kniption of «< Sometimes tbis phenomenon appears -with 
immense force. The inhabitants of the neigh* 
bourhood still remember with terror the eruptioa 
of 1 777, one of the most violent yet known. Qa 
the 29th of September were first heard dreadfal 
bellowings all around, while the earth shook to 
the distance of some miles ; and from the midsi. 
of the plain, 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 siz^si^which darted 
violently and vertioally within the body of the 
column. This terrible exployon lasted half aa 
hour, when it became quiet ^ but, after a few 
minutes, resumed its force, and with these inter- 
mittences continued ^1 the day, but the smoke 
lasted all the night. During the time of this 
phenomenon, a pungent odour of sulphuratedv 
hydrogen ga& was felt at a great distance, to the 

^ •P.43. 



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WOMB III. IHDVBATKB MUD. 977 

earprifie of the inhabitants^ who did not dare to 
approach this spot on account of the horrible 
iK»ses. But many came the following day, and 
found that the new great orifice had ejectA 
several streams of liquid chalk (creta)^ which 
had covered with 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 smdl 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 HypQubmes : 1. Entire ; S. Mingled 
with various substances. 

* Ferr. 45. The name Macahiba U Arabic, signifying the place 
of spilUng or ovtriurning. This phenomenon ia mentioned by 
Solinus ; nay Plato, in his Phoedo, mentions the torrelit or spring of 
JTiud in Sicily. ^ 



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978 POUMtW XtL yfOLCkVUS. 



NOME IV. TUFO. 
* 

CompontioD. This may be regarded as the foarth and lasi 
of the great volcanic ejections. It it chiefljr 
oomposed of rolcanic sand and powders, or 
what are absurdly called ashes, of pulverised 
lava, dross, and pBmice. When it consists of 
ferruginous clay it is properly caJied puxzolana ; 
when of pumice in a recent state, ra/Mf or 
■ilapUh. For as earths are no longer distingnisb* 
6d from stones, the difference of cohesion not 
altering the nature of the substance, so tufo^ 
may be regarded as of various indoratioBk 
These remarks, however, naturally lead to two 
grand divisions } the hard tufo, which is used 
as stone; and the soft, or incoherent tufts 
which is also called puzzolana, tarras, kc 
Trfo^ Troil has observed, that the greater part of tiie 
Icelandic mountains consist of tofo; and Heda 
often ^cts brown and black pmnice, 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 



Iceland. 



* Italian writers alwa;^ pat t^9. It mig^t be a not mnsefd 
^ dbtiiiction, as already itated, to confine ttffa to tbe'ealcareooi tt^ 

^ other depositions merely aquatic. 



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powden. 



base of the motrntain may conmst of date i and 
the red puzzolana of the Italians may be merely 
that substance affected by fire. 

It is well known that, during the grand erupk ^f>^^ 
tions of volGaooes, the sun is often bid, for entire 
days, with thick colomns and clouds of com* 
mhmted substances, called ashes by modern 
Wfitmi; while the ancients, with their usual dis-> 
oenmient, tised the word powder*. On t&eir 
fall, these powders become coherent and in- 
dorated, 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; ^e city Pompeia baring been over- 
whefasied with a hail of pumice, while Hercu* 
laneum was buried under a shower of powders; 
awl in the theatre, constructed without a roof as 
iMial among the ancients, a piece was found 
impressed with the breasts of a woman, who had 
perilled; a circomstance which evinces the 
tetmky of the snbstance. The hills of the isle 
of Ponza often present a white argillaceous tufo, 
^Uremdy soft, being chiefly composed of com« . 
minnted pumicef. Breislak observed in Ischia, 
IhBs of a fine white tufo, sometimes stratified } 

* Jww/nAif gU dUi pubere, papuiosjiHe subUa no» itmdL 
Seneca Qoest. nat. 1. 8. &c &c. 
f I>olomiea4 pDfices» tl8. 



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3gO DOMAUr XII. VOLCAKIC. 

and it Sometimes assumes the i^pearaoce of 
^ pisolite. 

A chief part of Dolomieu bas asserted, that tufo forms nioe 
ToioDoeB. ^^^^^ ^^ Mount Etna, and ite filial hilbj bat 

Ferrara, a more competent observer, wiU aot 
allow that one-half is of this substance. The 
recent eruptions of this grand and perpetual 
volcano have, however, been chiefly remarkable 
for those ejections of drosses, powders, and sand, 
^f ^ which form tufo, as the reader will observe froQ 

the following accounts of Gioeoi and Fenran^ 
yet untranslated ; and who, being skilful mioe- 
talogists, deserve more confidence than commoa 
travellers and narrators. Som^ 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. 
Remaiiua^ in Gioeui's accouut of the eruptiop of Etna, in 
July 1787> is introduced by the following re- 
marks of Dolomieu, and letter of the French 
Consul at Messina. 
Doimni^t ** While ou the point of closing the enumera- 
tion imd 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 June^ 



lite eniptioDs. 



account. 



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1 



HOMt IT* TV»0. 981 

and were the foreranners of an eruption) which 
manifested the greatest activity about the middle 
of July: the eruption was remarkable on acr 
count of the immense quantity of ashes, sand^ 
and light pulverulent scoriae, which issued from 
its crater*. They cbvered the mountain, were 
expanded over a part of Sicily, and carried even 
as far as Malta. 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 
magnet : the sand was mingled with small and 
somewhat transparent crystals, of irregular 
figure, which, seen through the microscope, 
appeared to be a porous vitrification ; this s^nd 
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 numerous products of scorification announce very 
considerable effervescence, and are constantly attended with a gpeat 
diseng^igement of elastic fluids. Hence the column of smoke and 
flame rose to an immense height f. and the atmosphere was infected 
tvith th* odour of lolphar.*' 



. \ 



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f 

obierrationa P have gifcii io this eatak^^ue. I 
cannot therefore temiiaate thia work BMMe pro- 
perly, in my ofHiiion, than with an extract Croat 
a letter of M. L'AUeo;ieQt» French Gxmii fd 
Messina, in which some cmioqs (details wiH be 
fiHind ; and a traadiation, by myself, of the nar* 
lativf of the Chevalier Don Joseph Gioeoi, pnb- 
liflhed in Italian, at Catania, in Sqpitember 17B7. 



'^ Extract rf the Letter of IL VAtLZM%9% 
French £1om$uI at Meetku^ adiramd i9 
tie Commander Dohmku^. 

Letterof the " Precisely six years and two months nad 
elapsed since the last external symptom of fer- 
mentation exhibited by Etna, when, towards the 
close of the month of Jnne, the cloud of smoke 
with which its summit is commonly crowned, 
was observed to increase in size ; this smoke oc- 
casionally assnmed 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 fbr two 

* He was a Knight-commailder of ihe Older of 



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IKMII IV. TVPOk 



dafti il«;ciipted a space on the dope of tw# 
nilm; becaaie» oa coolin^^ grey and shiaii^l 
awl (or a tioie all oeased; 

<« Ib tbe night between tbe 9th aod 10tfa» 'am 
aarora borealis ,was diatingvbbed, which wa» 
Tisihle Ibr llie space of half aa bour^ vni ivas 
tepeatedi it was laiigel/ spread aod cav»*e|t tbe 
whole ho^on from Monte Rosso as &r a$ Nota: 
lis colour was that of light, but soiaewhat deeper, 
and lis direction being the saoii as that of the^ 
eraption which it preceded, many conceived H 
to he connected with it, and even £M«told that it 
woaU happen. 

^< I0 effect, on the ISth, a black and diick 
loaake was i^ain seen on the summit, wbi6h pro* 
gcefisif^y increased, and fire was ^ot forth 
more frequently and in greater abundance 1 butj 
in tbe mormng of the 16th, though tbe glare of 
the Mia and the thickness of the smoke prevent^ 
ed part of the active fire, whidsi issued from the 
mouth of the volcano, from being seen, the ex* 
treme heat of the atmosphere^ the noise firom 
the moofitaio, and tbe sabterranean explosions 
which shook the whole of its base, annoninced 
the violence of the eruption being at its acme ; 
stiU this was not the' case until tbe next daf« 
and at ten at night it presented a most terribk;^ 
{not, at the same timi^ a most iAteresting iq>ec« 






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384 OOlCAtH Xlf. VOtCANlC. 

tBcle : a column of 6re, of astonishing vg 
was seen to rise from the mouthy the he^^ 4f 
which was estimated atabont five hundred tonesf 
^ St the same time a strong lateral corrMt of laya 

4 was discovered running in a south-west diredicHi^ 

and which leaving the base of the column, i 
ed alright atigle with it» the lines nearly < 
in length. ^ 

** The column itself presented in the cokmn 
gi ^it displayed th^ greatest variety : the in^med 
f- part> abounding in a prodigious quantify of 

water and sand, was occasionally mingled with 
a chiar* oscuro, which at every instant thTeateci!-» 
ed the flame with extinction, but whidi ulti- 
^ mately tended only to increase its vivact^ (Itod 

on these <^casions was it that the eruption was 
distinctly visible at Messina), and the dark and 
caliginous part above, throughout its whole ex- 
tent, was illuminated by flashes of fire^ electrical 
aigrettes, and evulsions of igoited stones; so that 
what with thie^explosions of the crater, and the 
incessant subterranean rumbling, a strong svm* 
^ litude was afforded to the ear of a distant 
# * tempest. 

^* This spectacle was prq^nted daring two i 
successive days; on the 19th, all seemed ap« 
peased. It is not with Etna as with Vesuvius; | 
for no one presumes to approach this mountaiii 



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IIQI» IT. TVfOt. * ji85 

when in a rttte of fermentation^ and only after* 
severai days of tcanquillity dares even the ob- 
aerrer venture on his researches. 

V All that can at present be said is, that the 
great current of lava which flowed from on^ of 
the sides of the crater^ ran the space of four 
leagues, alfcemately threatening the town 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 oiJaciy destroyed almost all the crops. 

** The following are the results of the obser- 
vations of those who, after the termination of 
tlie last eruption, visited Etna: 1^ The summit 
of Etna is inaccessible from, the vast quantity of 
lava, and of black and friable puitice (drosses), 
with which it is entirdy covered, smd which yet 
retain an intolerable heat; 3^ 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 ; S^ The 
matter of the eruption is of two kinds only, 
saline, and earthy ; 4^. By analysis the saline 

VOL. !!• a c 



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9^ 90Ukl9 xiu roLCkvic. 

mittter is faond to ooiuiist of sal ammoniaci in 
white and yeUowidi crystals^ and in a toleraUj 
pure state; and many compounds of sal ammo* 
nriac, mingled with very fine ToleaDiic sand, 
whieh has prerenHed this salt from assomiDg its 
natural form and colour : the earthy matter is 
compounded) in various proportiiMiSy of eaiih) 
clay, iron, and lime/^ 



" Translation, by DolomieUy of tke Narrative 
of the Cheoalief Don Joseph Gioent, 
Member of various Academies, and an In- 
habitant of the first Region of Etna. 

" loterdum^e atiam prorompit ad Mhen niibein« 
Turbine fumantem piceo, et candente fevlllL 

ViRQ* L iii. JEn. 

Qi^^eni^i '< From the year 1781, the epoch of the last 
account, ^f ||p|iQ|| ^f Qina^ that mountain continiied per« 
fectly inactive; rarely did smoke ascend from 
its crater^ and even during the earthqaake» 
which destroyed Messina and part of Caiabria» 
the vents of this volcano seemed to be closed, 
i^t • << About the middle of the last m^nth of June 
1797f I inhabited a country-houte in the middle 
veg^on of the mountain, and duly reosiarkecl a 



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Monriv. TOM.' ^ . 909 

smcAoe urUolr, lAButng ftom the crater, fetti oa 
tbeeone, and covered the maimit of the y^ 
cano; Ic^servedoccastonaUy^^hirtngthe^lgh^ 
thi^ this smoke towards the centre wai» of the 
oofoor of fire; it gradually augmented to the 
S4feh of June, when, by rising in a Tertioal co* 
hann, it foretold a speedy eruption. 

*^ Flames were visible on the evenitigiiof the 
same iday, and continued to be so untai the night 
of«he«7th. 

^^ On the 28th, at eight in the morning*, an Thibkiiiioke. 
iaimedse column of smoke was seen issuing 
from the crater, of white, black, and red colours, 
which, aftter attaining a considerable elevation, 
was unable to sustaici its weight, and, as if com^* 
pressed, assumed the form of a pine ; after this, 
it sent^rtba horizontal line, forming an angle 
of 80 degrees with the column in a vertical post* 
tion, and taking a direction towards the south* 



^ This specif <^ thiek and opake elimd) 
formed by the smok^^ after travernng a part of 
SiO]ly,exflnided forty miles out to -seas itshowf 
ered over the whcJe space it covered a quantity 
of light scorise and ashes; while this^was pass- or draM««ia 
ing, fresh melumes of thick smoke rose from tite 
cratier, took at a certain; elevation the same di* 
rection along the horizon, and frimished the cloud 
<^ 2c2 



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with the volcanic matters it incesasantly show* 
ered down. This cloud continued thus supplied 
until the night of the SOth, when it wholly dis* 
appeared*. 

f< In the morning of the SOth, Catania and 
the neighbourhood were covered with a small 
layer of extremely fine powders. 

<' The flames and smoke continued during the 
night ; and the smoke, extending from the sum- 
mit towards the west, indicated the direction of 
an eruption of lava ; the volcano continued io 
this state without any remarkable aItei)gtion^ other 
than occasional subterranean shocks* 

<* On the 8th of July, at two in the afi^moon, 
the smoke increased, rising in white and opake 
globular clouds, which rapidly succeeded each 
•other; by these clouds the mountain was cover- 
ed, and the atmos^ere 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 und%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- 
njliked that the smoke had fonned a beod towards the south, as, 
on leaving the crater, it passed over TrtfagUetto 9M Zafwritna, and 
tlMDce, directing its coune by the woods of Jaci, it nadied Uie ica 
above Santa Tecla" . 



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3 



HOME IV. TUPO. 389 

while the smoke in the west and north-east was 
furrowed' by continnal flashes of lightning of I4i»twn««. 
various colours; this smoke so much resembled 
a' cloud laden with hail, that every body con- 
ceived it to forebode a violent storm ; the cloud * 
remained in this state the space of four hours, 
when it was utterly dissipated by the violence of 
the wind ; the flames continued three days and 
nights without intermission. 

" On the 12th and 13th, neither flame nor 
smoke were visible proceeding from the crater ; 
and on the ftight of the ISth, three quarters of 
an hour after nine, a weak auror&borealis was Aaron 

borealif* 

distinguished, beginning towards the west, and 
extending eastward, passing noi^h of Etna; this 
illumination ceased about eleven o'clock, bi^t 
re-appeared, in the same position asj^efore, at* 
one in the morning : it then *hibited radii, ap- 
parently diverging from a centre behind the 
mountain, and at intervals shone with more 
• splendour than atrothers ; it continued thus visi- 
ble the space of an hour. 

^^ On the following days the flames increased, siiotl^ 
the subterranean roarings were loud, and the 
concussions so violent as to shake the houses $ 
deeming my!Self therefore no longer safe so near 
the summit, I remored to Catania. 

'^ In the night of the 17th, and throughout a<nidt of nnd. 



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390 SOMAIK XII. VOI.GAVIC. 

the 18th, the subterranean noise, was almost un- 
interrupted; at five in the evenings clouds of 
white smoke» streaked with black, sprang forth 
in rapid succession, the one cloud driving for- 
"^ ward the other ; they covered the mountain and 
spread over Catania, excluding the light of day 
during eight hours ; the clouds showered down, 
1^ almost perpetually, a rain of very shining black 

sand; the atmosphere at first was loaded with 
vapours of a reddish yellow colour, which were 
perceptible the space of an hour, and diffused 
on all sides a smelt of sulphur, thM continued 
for several hq|irs« 

<< While these vapours infected the atmosphere 

the thermometer of Reaumur rose from 241 ^o 

*^T (7iT to 83^ of Fahrenheit) ; which proves 

•that the ti^mperature of tjtie air was increased by 

the heat of the satfd. 

*< In the course of the first three hours this 
rain of ashes formed a bed two thirds of a line in 
thickness; in the five succeeding hours, the 
quantity that fell was the third of a line. 
^ggj^^ *^ 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 onoe^ or at separate inter* 



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Fals, aind shot forth an abiuidaiice of ignited 
stooies ; part of which felling back into the 
cimter^ seemed to augment the violence of the 
flame, while the other part rolled to a consider* 
able distance down the flanks (rftbe cone. 

'^ The anoke^ acoumnlated at a considerable 
kright, was mingled with flmnes, which cast a 
light on objects similar to a weak moon^light ; it 
occupied a great horizontal ertent, abo^e which 
rose the three colamos of fire. Another column 
of very dense smoke was noticed^ proceeding at 
intervals ^om a vent in front of the withers ; it 
concealed for some instants the centre of explo- 
aon^ and> extending towards the' souths united 
with die odier smoke, which, forming an arch 
several miles in length, served as a conductor to 
the deotrtc fires ; its extremity was frequently 
farrowed by lightnii^. 

^ The height of this polumn of fire, which CofamBorsre. 
omtinued from eleven o'clock till midnight, seen 
from Catania, was estimated at half that of the 
monnlain. 

** After the eruption had lasted five hours; 
the mountain was enveloped in the deepest dark- 
nesfiy except the crater, which still emitted 
fla&es to the same height as the day before; 
besides die first, three other currrtats of Uva 
seemed to be ejected i one towards the east* nd 



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two tovi^rds the somb, and all in divergaext radii 
from the crater; but observing them afterwaidi 
with a good telescope^ I perceived that the three 
supposed currents of lava were no other tfaaa 
masses of scorias heaped together during the^ 
eruption, which continued to burn on the flanks 
of the cone, and which became eictinct at four 
in the morning. 
^ ** A second eruption seemed to announce it* 

self on the following day, when, at noon, an 
immense number of whirling clouds of white 
smoke issued from the crater, spread themselves 
from 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 terminated in flashes of lightning, similar 
to those of the day before, rather more pale, and 
which issued from the more elevated globes. I 
afterwards understood, that in the second and 
third region, some aqueous clouds uniting with 
the smoke, a very vielept rain fdl mingled with 
volcanic "Hnatters, differing in a small degree 
from the first; in the space of an hoQr> the 
whole was dissipated, and the mouniaia was 
clean 

*< The ordinary flames continued during ihe 
night of thte 20th of July ; they somewhat in- 
creased at two iu the moming> and even assumed 



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^ 



the form of a colamn; bat the fenmitfttion 
diminishing, they resumed their former appear*^ 
ance in abont half an hour's time^ and preserved 
tbe sameduring two or three days, subsequent 
to which tbe mountain resumed its pristine traiii* 
quillity. 

^^ It is evidently visible that, on this eruptiont 
the extent of the crater was diminished towards 

4 

the south, and increased towards tbe west. 

*' From the testimony of individuals worthy Site tiiinmm. 
of credit, I learn that, on the 18th of July, 
blocks of dross, weighing a pouild and a half, 
ejected from the crater, fell in the valley oiBue^ 
that is to say, five miles and a third part of a 
mile fnHD the spot; others likewise were ihrowa 
to differa[it distances, in all directions round 
about the crater, diminishing in size in proper^ 
tiOD to the distance. '*" 

*^ At La Cava Secca, six miles from the crater, 
some fell the size of a pigeon Vegg ; at twelve 
miles ^from it, fragment| of dross blended with 
sand formed a bed more than three ihches in 
thickness. During the rain of which I have 
spoken, the whole of the middle region of Etna 
was enveloped in darkness; but chiefly in the 
eaailem part, where the greatest quantity fell. 

** The inhabitants of Zafarana vfefe unabl^ tp 
see each other at the distance of two feet; and» 



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5^ OOMAIV XII. voi.C4iric. 

when tro flames began to appear^ they wwe en- 
Tdoped in vapours of intolerable heat; theyima^ 
gined the mountain was sinking into the abyss 
fiom which it sprang: part of the inhabitants 
abandoned the yiUage, and consternation waa 
nniversal; the volcanic matter retained. a heat 
which it communicated to the atmosphere^ and 
the air. was loaded with reddish vapour ; the rain 
that £^ ruined the vinejrards and treea of the 
middle region, the latter in many parts having 
nothing but the trunk left standing. 

^ From Bronte we had information tha^ du- 
ring the night of the 18th of July, a current of 
lava from the crater surrounded a wood in the 
neighbourhood of the town ; ;tnd from its having 
made a progress of several miles in very little 
time, it caused there the greatest alarm. 

*^ Feeling a desire of examining on the spot 
the effects of this eruption, the more ejrtraordi- 
nary from its having proceeded from the summit^ 
and not occasioned an}^ opening in the flanks of 
the fountain, I repaired in the beginning of 
9nii^ August to Bronte : this town, situated north- 
west of the crater, stands at the distance of six 
miles fronn it, in a direct line ; within the inter- 
val are several volcanic mountains, and currents 
<tf lava which have traversed and laid waste a 
thick wood of fir^ whose deep roots were fixed 






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in ancient lava, decomposed and convmed into 
earth*. After passing those arid spots, I ascend- 
ed a hill, from which I clearly distinguished two 
new currents of lava: the first had flowed ^^"y^^ 
V. N. w. of the crater over the flanks of the 
cone, between the two territories of Bronte and 
Aderno ; I was assured that the breadth of this 
atream was a. mile, audits length three miles ; it 
was formed on the I6th and 17th^of July, and 
on the 18th the rate of its progress had so mucfti 
diminished that it ceased to .advance more than 
a few fathoms. I was unable to approach it, on 
account of the steepness of the rocks by which 
it was Mrrouuded. The second stream, whidi 
took the directicup n. w. by k.> was, dt its is* 
suing from the crater, half a mile in breadth ; it 
apread afterwards so as to become a mile broad, 
and descending rather in kn oblique line down 
the rapid slope of this part of the cone, divided 
into different currents, ii^jlh left bietween them 

* '* I was obliged to'^nveiae the current of lara, m0^ by the 
erapdon of 1766» the most receotVf aoj which tAk this direction ; 
I saw several streams of lava which had croased others, and which 
aflbrded me evident proo6 of the ftllacy of d» eonchmoos of those 
who ledc to estimate the period of the fonnanon o^he beds of kva 
fkoBI the^hangs they have imde^me. Some ]a||s, of earlier date 
than others, still resist the weather, and present a vitreous and un- ^ 

altered surfiuae, while the lavas of later date already beg^n to be 
covcicd'with ve^Biatioa.'' 

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395 DOMAIN tU. Y6LCAKlCr 

Tariou^ eminences they met in their course; 
these streams united to form but two branches, 
after having flowed over a space of four miies in 
a very short period of time, in the night of 
the 18th. 

^* Nearly the whole surface of this lava was 
covered with smoke, which issued from crevices 
in the mass, and which increased in quantity in 
proportion to its proximity to the crater; much 
smoke likewise arose from the crater itself. At 
two in the morning, the thermometer of Reau- 
mur stood at 191 (<5^44 of Fahrenheit*). 

'^ On reaching the extremity of one of the* 
branches of lava recently ejected, I found it still 
continue hot, and the heat yas more sensible 
as I advanced upon it. The thickness of this 
stream did not es;0eed sixteen feet. Placing the 
thermometer upon the drosses on the surface, 
the mercury rose to 28 (82\- of Fahrenheit), 
and had the guide aIlo\^d us to advance farther, 
the heat would have been still greater^. I 
brougtft away ispme o^ the fight drosses and 

* " Before I leachod the lava, I made an experiment with the 
neW atmospiherjipl electrometer of M. de Saussiire ; ihe air» not* 
withstanding"! ngftd my arm ^ith the instrament as \a^ as pot- 
4 Mble, exhibited no indications of electricity." 

t " The divergency of the balls of the electrometer, with whieh 
I here made some experiments, did not exceed the fkactimof a line; 

V 

f ^ *^ Digitized by GoOQIc 



IT. 



mu 



i|eavy lsnra> of which the wiiole of this current 
seemed to be composed. 

^' Learning for certains that there was not on 
the north of Etna any ne^ current of lava, I trod 
back my steps towards Mco20^/. I re-asoQoded 
the mountain on the 11th of August, and bent 
my way directly towards the crater, to examine 
the changes which an explosion so yiol^it must 
necessarily have effected : smoke rose from the 
crater in great abundance, and to a considerable 
height; but, driven by the wind towards the 
east, it was no prevention to my plan. 

^ From the very walls of Nicolosi I noticed 
Ant the- earth was covered with small fragments 
of light dross, wbich became larger in proper* 
lion as I approached the sununit ; I found they 
had covered the whole space denominated the 
plain del Lago^ in such nulnner that the former 
soil could no longer be distinguished ; the time 
of my departure on the ^^rsion was half past 
Dioe in the morning, and the thermometer stood 
i^T (^^i of FahreBDheit). ^ 

and it disappeared at three feet distance from the lava. To ascertain 
correctly whether or not there really was any«^fierence in the state 
of dcctricity» I several times got upon and descendec^from the lava, 
«Xhd fband not die slightest divergency of die balls on removing to % 
distance of forty paces ; the sligiht electricity in the lava was of a posi- 
tiTQ%iiid» as I convinced mysdf by means of a stick of Spanbh wax.** 



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Google 



898 



OOMAnr XII. TOLOAVIO. 



^ Ott tracking the Philosoplier^ Towrif^ o^ 
guide measured the height of tbe bed oiAroma^ 
•nd finind it three feet^ but^ at the fool of ibe 
cone^ two miles distant from the crater id a rigltt 
li»e» J computed the itratittn of drMea to im 
twelve feet in thickness. 

^M ib^nd a mmiber of insoUfted round UogIq^ 
which bad been thrown out from tiie wlcaM 
towards the w. s. w., and in the same directioa 
Another I >9aw a Current of iava, still inflamed and smok* 
^^"'^^^ ing, ivhich was descending from the crateiv aad 
at its origin wasaboal half a mile m bieadlb $ it 
aAiMniirards swelled to a breadth of thrte mUes, 
and extended two miles in length ; thebeig^of 
die current, at its sides, was from twehe io m» 
teetf ieet, but in the middle twice car eiea fear 
times ag much; the current continoed to recdrvi 
fresh matter from the crater, as was indicated iy 
the slow motion of the drosses with wfaiefc ill 
surface was covered, and the flames wUch pra» 
ceeded from the occasionally cloven suifitce, and 
which, notwithstanding the daj-ligbt, were vi»- 
ble; we at the same time perceived that tbe 
progress, in a forward direction of tbe current; 
was arrested. 
Cone. *^ The portion of the cone we hadttf passi^ui 

• Probably bniU i9bm the En^eior Hadnia twin vkM 
Etwu— P. .. 



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m 



999 



k^ 



Oider^ reaeh the crater» being eotered with 
this lava, we were oonsequently obliged to ad* 
▼atice over it, following oar guide, who picked 
Ins steps, choosing those drosses to tread upon 
which were the least friable ; but our labour waA 
vain, since, on reaching the looked^for term of 
oar journey, so great a quantity of smdce issued 
as entirely to fill the month of the crater, and 
prohibit all approach. 

^* The guide, who had paid a visit to the same 
spot some days before, informed me that he per* 
ceiyed a. considerable increase in the fermenta^ * 
tion of the mountain ; and what he stated was 
confirmed by a smoke, which ascended nrom 1^ 
number of the chasms of Monte Rossa^ although 
this mountain is at a distance of three miles firom 
the crater. 

^< Before I quitted the lava, I placed the ther« 
mometer on a piece of heavy dross, about the 
middle of the current; the mercury, in two mi« 
nutes, rose to 2i\: {72i Fahrenheit*). 

* " The difficulty of the situation did notadmit of my iD«klO| 
experiments with the electrometer; but on examining this instru- 
ment, at the distance of a mile from the crater, I found the diver- 
gency of the balls extended to three lines and a ftaction; thisl^en. 
lH«^p«d to be owing to a elovd.'vrhich waa patting perpendicularly 
over my head ; when the foot of the electiometer touched the earth, 
the electricity disappeared ; and repeating afterwards the experiment 
I finmd the divergency did not exceed one tine." ^ 



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^^ ADD tMUMtB XII. TOLCXVIC. 

** Directing now my steps towards thft part 
of the cone which fronts the south, I found there 
Mother small current which bad not, like the 
i«st, proceeded from the crater, but which, on 
the 18th of July, formed an opening for itself, 
half a mile below the crater ; this eruption had 
fiurmed a small mountain of a conic form, with a 
lateral opening, through which the current Sow* 
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 occasionally concealed the firet 
Irpm tne gre^t crater. 

<* This partial eruption was not visible fitmi 
Catttnia, on . account of the interposition of 
Monte Rosso, immediately between the summit 
of Etna and that city, 

*VThe appearance of these two small streams 
is 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, and rem%k* 
ed their figure to be a pretty regular oval ; their 
larger diameter was five, and their smaller three 



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mourn lY. rroto. j|0| * 



feet ; I fonnd a mnilar block projected th6 di^ 
tanoe of three miles, its diameter one Way was 
eight, the other four Feet ; its prodigioos weight 
had occasioned it to bary itself almost entirely 
ID the drosses^ and its smface alone was visible. 
*^ Pieces of such great bulk are not numerous ; 
but it is impossible to calculate the immense 
qnantitj of light and heayj drosses, which, at 
various elevations, cover the cone itself, atodthe 
country fw 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 ^ould form a solid mass, i j}clud- 
ing interstices between the parted streiams, of 
6^18,661^6 cubic feet. 



« PRODUCTION OF THE ERUPTIONS OF THE 
MONTH OF JULY, 1787- 

<* I have minutely examined' the productions 
of this eruption, which may be reduced to the 
following varieties. 

^' No. I. The first rain of volcanic matter, at DroMeiaiid 
first sight, appeared to consist of a yellowish ^^W^ 
puzaolana, such as is found near the craters of 
volcanoes, after their having been long extinct ; 
it is. composed of pieces from the si^e of dice l 

VOL. IT. *^ ,. 2 D 



# 



^ • 4, 



3 



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|0g 0OKAIK Lftif. . iFoiXMtie. 

down to tM 9i tliAiiiiett. powdnid Md is a 
pcMOW la^a, lights tQodeo a«} Miw&«bat re^ 
femblui^ aa lucgjilliicf oos aubsteooe* ik^ich is 
MtriAg?uttothetQii^; sopae^oCtbagnuos ajpe 
lUHd lava» heavy, felTttgU¥>Ufc and iQ round 
particls^ Neariy tmlf of this fint miciiaiii rain 
eomuited of Teiy fine powdewa tbtte> seen 
throagb a joioroscopei appear to be conposecL 
1, of cryrttals of black schorl*, which paitiaUy 
rettin their prismfttic shape, and ara partial! j 
eaten by rust; 3* vitreoas grains of similar 
* SQboil ; 3. grains of lava whieh ht^fCimidergpne 

alteratiqni apd are reddened or wihttmfld hy var 
poi^r; 4« crystals of felspar, detached^ and al- 
though somewhat decomposed, preserving their 
rhomboidal form; 5. other crystals of felspar 
adhering to lava, changed and covered with 
fiBtrina externally, but internally untouched ; 6. 
fragmente of lava with small crystals, similar to 
the arsenical ruby; 7- others incmsted with 
flowers of sulphur ; 8. vitrifactiona of no regular 
figure, porous vitriiactions, and a species of 
black glass or obsidian, transparent at the ^ges 
and of «a dark green colour, 
n ^< The matter here analysed was coilected on 

the snows of the crater at Trifbglietto. 

.4 * 8choriwaithtnanMBtfariid«ite.of honJ»lwdfc-iP, 



» 



# 



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HOMB IT. TJFBO. 401 

*• No. II. Heavy droises of neafTy wot oval 
shape^ and weighing from six to eight andnmd 
pounds; siich were projected the distance of- 
fottr miles firom the crater ; ^ superficially they 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 conliutis crystals of white fdisptt conftisedly 
dispersed^ and some volcanic chrysolites. The 
crystals of felspar preserve their transparency^ 
and are merely a little glazed, while the chryso- 
litei^ have undergone a species of fusion, which 
has combined their grains, and rendered dieir 
surface convex. 

** These dirosses are found round the crater, 
especially ftoni the southern to the eastern side, 
as well as in the valley of Bue. 

*^ No. IIL Light whitish drosses, similar to 
the cavernous pumice-stone of Lipari ; they have 
the same fibrous texture and prdonged pores ; 
some little light drosses,, of a black colour, ad- 
here to this pumice, which separately floats on 
the-water, but which when^ atfaclied to the black 
drosses, is carried by their gravity to the bottom : 
this is the first instance known of Etna having 
produced a inmilar substance. 

« Found on the W. S. W. torrent of lava, near 
the crater. 

Sd8 



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404 BOMjan xtu vdLCitiric. 

** No. IV. Light drosses in separate. pieces; 
the largest are ten inches long, one in width, 
and two in breadth ; from this size they dimi- 
nish to that of a pigeon's-egg; their pores are 
rounded, glossy, vitrified, and of a pitch black; 
some of them seem to be damp a^ soot; seen 
through a magnifying-glass; they appear a real 
vitrifaction, porous, and of a greenjish colour. 

'^ These drosses are found at a greater distance 
from the crater than the former; some even as 
far from it as six miles. 
Smd. ** Not.V. A very fine and shining sand, which, 

seea through a microscope, is found to be com- 
posed of grains of volcanic chrysolites, trans- 
parent, and of a golden green, and greenish 
colour. Among the sand also are fragments of 
transparent quartz, and laminated felspar. 

*^ Sand of this description fell at Catania, on 
the 18th of July. 

** No. VI. Light sapd, formed of small grains 
and filaments of a glossy vitrifaction, analogous 
to the dro;sses No. IV. 

" 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 July ; it is mingled with fragments of 
the drosses before noticed. 

" No. VII. Puzzolana composed half of crys* 



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tals of black schorl, which hare 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 
M^ith 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. E. by S. to the S. W. 
wherever the watery cloud mixed with the smoke 
which contained it was carried, and firom which 
it was precipitated by the rain. 

" No. VIII. Pieces of lava tolerably compact, Pebbies oi 
of an oval or wedge-shaped form, from two or ^ 
three to^welve inches in length, and from one to 
six inches in thickness ; the surface vitrified, and 
exhibiting small pores ; their interior similar to 
that of No. II. They resemble pebbles rounded 
by water, and are remarkable among the drosses. 



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406 



DOMAIN XU. VOLCANIC. 

amid which they are found, on account of their 

singular shape. 

« They ace collected on the cone of Etna, 
lying among light drosses. 

« No. IX. Other pieces of the same fonn, 
but more comif>act : the surface of these is more 
smooth, and is sprinkled with white spots, which 
seem produced by the vitrjfaction 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 ra 
length, composed 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, diviaiblc in 
parts, with a vitreous incrustation : one portion 
exactly resembling lava, which elicits sparb 
when struck with steel ; the laminsB arc distin* 
guished one from the other by their different 
colours, the result of a calcination which has 
acted differently on the various component mat- 
ters j in it mica and felspar are found in an nn^ 



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moun XT. vuvo. 407 

altered state. la one <^ ike hMtat tarevtyBiah ^ 

of prismatic schorl ; and in all the cavities is a 
white fibrous radiating tnatMr, ^ieh I conceire 
to he asbestos in a ohaniged condition, owing to 
the action of fire. 

** It is foond on the cmtent of lara^ at the foot 
oftliecone. 

^' No. XII. A grey lava with earthy grains^ Lm* 
which, notwithstanding, yields sparks with steel; 
its base is composed of a great number olpoiikts 
and laminae of fdspar, with some crystals of 
black Tftreons Itnd pristafllic schorl, and a few 
grains (^greenish chrysolite; this lava, on being 
moistened, jridds a smell like clay^ as also do 
•he two following lavas. - ^ 

«< It "fs a t'esult of the lee^r eruption towards 
the south. 

^ No. Xm. Compact lava ishowing a vitreous 
fracture, the base of which consists of small 
shining points^ resembling talc, mingled with 
diminutive laiAeUsB of white felspar, and some 
chrysolites of a duH green colour : this specimen 
was apparently fissile. 

^ This proceeds from the same eruption. 

•* No. XIV. A lava of a dark grey colour, of 
the same species as the foregoing; it is of 
mooghcr grain, and the talc still preserving its 



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408 DOMAIN XII. VOLCAMIC. 

lustre has become agglutioated, and.compreiaed 
by a kind of calcination. 

^^ Its origin similar to the last. 

^< No. XV. A black lava with a base of felspar 
and chrjsolitei to which fire has imparted dif- 
ferent colours ; it comprehends rhomboidal crya-. 
tals of felspar, and crystals of vitreous schori 
and mica. 

^' From the eruption of the west-south-west 

** No?. XVI. Lava in beds of different sub- 
stances : one of them is compact, very hard, of^ 
fine grain, with laminas of felspar; the other has 
regular pores, with laminas of felspar which 
cross each other, and vitrified grains of a green* 
ish hue and semi-transparent; this lava, on 
being moistened, yields a strong smell like 
clay. 

<< It is a product of the same eruption as the 
lava of the preceding article. 
. ** No. XVII. A compact and very hard lava, 
with a vitreous fracture ; its black base contains 
small laminae of felspar, with a few crystab of 
vitreous schorl. 

^' From the same current of lava as the pre- 
ceding. 

V Not XVIII. A very hard and compact lava, 
black, and sprinkled with points varying in sife^ 



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MOItB IT. TQffO. 4P9 

formed by a black shining glass, which still re* 
tains the fignre of the crystals of schorl contain- 
ed in the base, which was oh the point of fusing 
into a state of hoiliogenous glass. 

*^ From the same eruption. 

••. No. XIX. A dark grey lava of a rugged 
fracture, the base of which contains similar 
scales of talc as No. XIII. and No. XIV. with 
same laminae of felspar faintly apparent. 
' '^^ Found in large oval masses ejected by the 
volcano. 

** No. XX. A porous lava, of similar nature 
to the preceding, with a stratum of vitrifaction, 
mingled with laminae of mica, radiantly disposed. 
From the same. 

« No. XXI. A species of stalactite, or con- 
cretion, found under the preceding lavas ; it pre- 
sents three varieties: 

*^ 1. With a friable base, and laminae appa- 
rently of mica. 

•* 2. With a coating of silvery talc. 

^* 9. With a coating two lines in thickness, 
' consisting of a white powder, which is salt of 
Sedlitz, deprived of its water of crystallisa- 
tion. 

" No. XXII. An incrustation of selenite, of a 
mingled white and red colour^ in thin strata. 



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410 VOMAm KlU TMOMnC. 

feRniog a ooftting of two lines in tbtdoiessy on 
vhioh are smail gnoot of a similar nature*. 

'^ Found in the fissares of the w. s. w. cor* 
rent of lava. 

<^ No. XXIII. Deliquesoent sea-salt with a 
martial basis, which flows from those light drosses 
which are of a reddidn jellow colour. 

<< From the same fissures. 

<'No. XXIV. Martial vitriol adhering to 
many of ^e preceding drosses, now of a lively 
red, now of a greenish yellow, and now of other 
edoun: these drosses ranain yet partially co* 
vered with the selenite of No. XXII. 

** From the same spots as the last : in the 
eruption of this w» s. w. current it was very 
abandant 

^ No. XXV. Martial sal ammeoiac, subli- 
mated in very thin needles, two or three lines in 
length, and adherent to a light cellular lava of a 
reddish yellow colour: on examining these 
needles with a microscope, small articulttdens 
are clearly distinguished, composed of octaedra, 
placed one on the other. 

* " These incrustations of selenite are found in veiy great abuM 
dance in the two new currents of lava ^ they evinoe the prompt 
activity and powerful effect of the sulphuric acid on the calcareooi 
molecules of lava, especially when assisted by heat.** 



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JVOIIB IT. 7UF0. 4tl 

'< From the same fissures. 

** No. XXVI, A bard lava, the base of which 
contains many small laminae of felspar and 
grains of volcanic chrysolite, coloured by fire, 
and some pretty large dusters of the same kind 
of chrysolite. 

** From tile current of Java which flowed to- 
wards Bronte. 

** No- XXV IL A hard> grey, and dullish lava, 
with abundance of laminsB of felspar, of greater 
size 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 specimens of lava I have de- 
scribed, show UK the nature of the various kinds 
of primitive stone, which constitute the base of 
Etna) they demonstrate also that the rocks, 
which enter into the composition of these erup* 
tions of lava, undergo little change fl-om fire ; 
and that, in the last eruption, the granitoid schist 
had been chiefly attacked*. 

^ *' From the indications of the Commander Dolomieu> who has 
dkcoveced in the Neptunian momitains (or those of Peloro) all the 
pfini^vefocka found in the various lavas evolved from Etna, I har9 
royaelf made a large collection of them -, these I have also compared 



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412 DOVAIir XII. TOLCAVIC 

^^ From the few historical memoirs which speak 
of the eraptions of Etna, we find that those which 
EraptiofB from have issued from the crater are comparatively 
far less numerous than those which broke for 
themselves new orifices through the sides of the 
mountain.^ 

*< The epoch of the first stream of lava that 
issued from the crater, which history has pre- 
served^ is that noticed by Julius Obsequens, whose 
testimony is corroborated by Orosius, to have 
happened in the year 2SI7 from the building of 
Rome. 

** The second is described by Fazelliy an ocu- 
lar witness, by Pkiloteus, and Sehaggio ,- it oc- 
curred in the year 1^36. 

** The third happened in 1607> and is de- 
scribed by Carrera and Guarneru 

'^ Massa speaks of the fourth, in the year 
1688. 

** Father Amico mentions the fifth, sixth, se- 
venth, and eighth, in the years 1727, 1782, 1785, 
and 1747. 

" And finally the Canon Recupero speaks of 
the ninth, which occurred in the year 1755." 



with the different species of lava, ajvl suppose myself capable of 
pointing oat, with the specimens in my hand, the different species 
to which they helong.*' 



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M6UM lY. tfitc. 413 

The intelligent Ferrara has given a chrono^ iccSS?Sf tht 
logy of the eruptions of Etna ; but has only de- «roptiOT» iw^ 
scribed those of 1800 and 1809 in the following 
words : 

•* 1800. In February, the mountain ejected 
smoke^ with those powders falsdy called volcanic 
cinders and ashes. During the night of the syth, 
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 
cohimns 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 tremendous 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 bit the 4th of March ; the eruption of 
inflamed masses was more copious, and the 
soHthem wind carried the dust even to Mildzzo. 
The inhabitants of the places in that direction, 
but more near the volcano, were greatly incom- 
moded with this dreadful shower. At Malvagna, 



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414 DOICAUI XII. YOLCANIC. 

fifteen mileB from the cratm*. the iky suddenly 
danrkened, and the people were obliged to light 
candlesj tbougb it waot^ an hour and a half to 
sunset, as neither business nor pleasure could be 
followed amidst the thick darkn^s* It seemed 
as if the darkest hour of the ni^ had fallen at 
once ; and the inhabitants neither knew where 
to flee, nor what was the cause, as thej only 
heard a rustling murmur. This uncertainty con* 
tinned for twenty •fire minutes ; after which be- 
gan a rain of black drosses, the largest of which 
were nine ounces in weight* But at Mojo and 
Roccella they were of thirteen ounces ; and many 
in the fields received wounds iu the^ head and 
arms* These drosses., had so nrach heated -the 
atmosphere^ that a copious .&U of raaHwater, 
which^accompaaied them» ¥ras quite hot. 

<« The eruption was. often rq^eated in the £al^ 
lowing months ; and the grandeuof the scea/^wm 
increased by frequent forked lightuiogs, which 
broke forth in the midst of the black smoke, 
having commonly one line peipendicular to the 
axis of the cone of the crater, while at ^tbe other 
extremity auotber rose at right ai^les> and was 
lost amidst the smoke and the flames* • . This long 
eruption ended in July j having formedion all 
the upper part of the mountain a stratum of 
natany feet of light drosses, into which form the 



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HOMB IT. TOItK 41^ 

Infft iHid beea reduced by the kitense faeat and 
fermeatattiMi^ 

** 1802« An eniptioa from a new aperture, a 
Utile under the crater, in the great vaU^y of 
Mme^ accompanied with horrid thunders and 
ttemendoua bellowings of the mountai^i. It 
oeaaod in a few days^ Imt the lava ran twelve 
9lik3. 

<« 1809. After the volcano had, in 1805 and 
1S06». ejected flames and copions smoke, at un- 
equal intervals, during which some undulating 
sbakes wem observable, chiefly in the slurts, 
ani -after a perfect calm in 1 807f during wbieh 
I oAeui descended to the bottom of the crater, 
aad'ta spots brfore inaccessible; in 1808; the 
fimquenti eruptions of flame >retamedy the most 
copious beiag always preoededrby prodigmus 
blowings. 'of the mouhtaki, and sabteMbeoot 
tbander^ not without some shocks sensibfy* felt 
even at Cataniat These having continued tH| 
M^Burch 1809» on liie STth day of that months 
after the rise of immense perpendicidar cdumns 
of smoke, was opened a new orifice a little^under 
the crater towards the n. w., fiom whicfa issued 
a river of fuUginQus sntoke, in the fontt.of emnri* 
mous balls^ with a slow ihotion, a» they were futt 
of powders and sand, which weie snatcbeAirir 
the wind and carried enm to.MesflitttL AAsm^ 



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416 1X>MAI« XII. VOLCANIC. 

wardSf ia a line, which from the third or o{]fen 
region of the mountain passed the woody region 
till it reached the cultivated lands of Castiglione 
and Linguagrossa, many new orifices were open- 
ed. One was at six miles distance from the firsts 
and the others at unequal distances; while 
throughout all the space many fissure 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 fell in iron sleei^ rashing and 
dashing against each other, produced a clam^Mir 
which filled the neighbourhood with dismay; 
on the 28th, at the approach of night, were 
ejected torrents of lava, whilst the mountain 
suffered the most violent convulsions, and re- 
sounded with horrible bellowings, which were 
heard even as far as Catania* The thunders a£ 
these apertures were pretty frequent, and were 
repeated progressively firom one to the other, till 
they reached the crater. The ei'uption couti^ 
nued for the remaining days of March, and the 
beginning of April, when the lava ceased; after 
having covered a space of eight miles in lengthy 
and ibur hundred and fifiky feet in breadth. 
Around the two chief orifices, in which the fire^ 
seemed at last concentrated, were formed two 



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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 and vapours would have 
opened new apertures, struggang as it were to 
get loose; While on the same spots long fissures « 
appeared, occasioned by the sinking of the 
ground. But the circle 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 undulation 
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 may be arranged under 
the following divisions: ^ 



VOL, II. S £ 



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4l4 aoiuiir Xiu TOLCAHie. , 

HTPONOMB I. HARD T0FO. 

This has often the appearance of a grey argil- 
laceous stone, and is used for building in various 
part^ of Italy. It is generally grey and porous, 
and sometimes Contains small leucites, wheace 
this kind is called partridge-eyed tufo*. It may 
alpo embrace fra^ente of granite; but when 
these are numerous, and joined with fragments of 
marble a^d other substances, it assumes the name 
of pepcrinoy which ^ a volcanic brida, or giu^ 
tenite. 

Micrcfumf I, Of Clay^ Sand, Powder^ Pur 
foiqe, Sfc. 

This is t^e miost usual form of tufo ; but tly 
olay seems to ^ chi^y inserted by the infiltiu* 
tion of the .paters from superior soils and euff* 
nenoes. ^ 

Tufb, frt>in Horculaqeum, Pompda, Icelfnd^ 
^c. &c. 

Hai^ tufoy fix>m Mont Anis and PoIi|p4c, JI91 
^ Auvergne, where it b used for4>uJi)dk^. 

• PBtrin, y. S98. The isle VeDtotiene (Dd. PoBoes» 41) ooi^ 
* sisU almost entixdy of a volcanic tufoy a soft stone with an aIg^- 

laceous base, includiog fiagmeDts of lava^ slag?, pumice^ See. 



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The same, with bitumen and chalcedony, from 
Clermont. 

Micronome 2. OfDros^ and pulverised Lam. 

This, in the course of ages, assumes consider- 
able hardness, while it shews its origin by its 
black colour, arising from the drosses or scoria; 
the latter are sometimes red from calcinatioq, 
whence seems to arise the name of Monte Rosso, 
ejected by Etna in the terrible eruption of 1669'; 
but the surface at least is chiefly incoherent. This 
tufo in particular sometimes affects the magnetic 
needle. Black tufo sometimes resembles wacken. 

A tjifo of fragments of lava, drosses, sand, 
augite, and conchitic limestone, in a paste of 
marl. Ferrara, p. 67. 

Micronome 3. With fragments of Granite^ or 
other substances. 

When these are numerous and closely set, the 
stone becomes a volcanic glutenite ; but they are 
sometimes rare and remote. 

A tufo of lava and limestone, from Cape Pas- 
saro and the rocks of the Cyclops, Sicily** 

• Few. 181. 



S£3 



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480 DOM Aiir xn. tolcaitic. 

BTFONOlfB II. SOFT TUFO. 

This is either found in an incoherent fonziy or 
easily crumbles into small iragments. Wheo ft 
chiefly consists of comminuted pumice it is called^ 
in its recent state, lapillo 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 scorise, or 
dross, in which case it is called black puzzolana ^ 
and at Naples a rapillo; now constituting, ac- 
cording to Dolomieu, almost all the mountains 
around Etna, with nine-tenths of that mountain 
itself*. ... 

The proper puzzolana, also called Trass or 
Tarras, which is used to consolidate buildings 
under ^ater, 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 
volcanoes. 

* Dolomiea, Etna, 3S3i 328. Volcanic Boona, like thosr of • 
tmithy, or more porous, form all the oonic mountains aioaod Etna, 
and peiiiaps nine-tenllis of its mass. At Naples tli^ are called 
rapilh. (Dol. Etna, p. 388.) They are of the nature of kva i 
while puzzolana is burnt clay. Ferrara, a superior judge, denies 
the extent of ihe tufos, and says they do not form one half of Etnai 
p. 336. 



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4j)l 



Microname 1. White Ttifo.^ 

This consists, as already mentioned, of comini* 
nuted pumiqe, and often presents larger fragments 
of that stone. It may, from the various influence 
of the waters, be indurated in some parts, and iii^ 
coherent in others. ' 

Micraname 2. Black and fed Tufo. 

Tufo, of comminuted black dross, firom 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 j^an^ 
jexplained ; but ferruginous tufos in general may 
be applied ti the same purposes. The tarras 
found near the Rhine is of the same nature and 
quality ; and is supposed, by impartial authors, to 
be of volcanic origm. A more candid and equita* 
\>le judge cannot be invoked than the patient and 
experimental Saussure, who not only allows thp 
mountain of Chenevari, and some others in the 
south of France, to be of volcanic origin ; but 
has also published m interesting accouHt of his 



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^%fg DOliAftr XII. VOLCANIC. 

journey to the extinct volcanoes in the Brisgaw, 
being in the Black Forekt adjacent to the Rhiiie*. 
Puziolana forms a remarkable feature of several 
extinct volcano^ ; but Mr. Kirwan, who has an 
inconceivable aversion for thpse grand phenomena, 
often passes 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 espe- 
cially to a maritime people, are more car^ully 
composed than those of any other writer^ and de« 
serve transcription. 

KirwMrt *'PUZZOIANA. 

fccomit. 

" 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, 32. 

" 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. 
^' f* Its internal lustre, 0. Its transparency, 0. 

"Its fracture uneven, or earthy, and porous; 
commonly filled with particles of pumic^ quartz^ 
icoriae, 8cc. ' 

' ^' Hardness,' 3. Very britde. Sp. gr. from 

• J^nua 4e iPhysique. New Series, vol« i. 



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ByS^Oy wHch k that of tbQ Uack; td 9,78J;> ranly 
£;8. . Has an eartib^ ^meU. : 

'^ It is fiot difiusible in cDld water ; but id boijU 
ing irater it gradually d^pteites a fine earth. 1\ 
does not eff«Srvesce ifrith abidb*. . 

^^ Heated, it assumes a darker colour, aoil 
tesily melts ihto a blafck, sUg j or, with borax^ 
into a yellowish greeaglassi ' 

^^ It is magnetic before it is heatbd^ but oM 
after; Thb is the hiost remarkable of its prd^ 
pertfes. 

^' By Mr. Bergnian's an^ysis, it codtciins from 
55 to 60 pet cent of sUei, 19 tb 20 of drgil; 6 dk 
6 of lime, and from 15 to SO bf ircm. 3 fieigm^ 
p. 194. \ 

'^ Widen biixed with a bm911 proportion of lime 
it '^Yiicldy hardens, land thid induration takes pladb 
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, subdlly divided, add iiispefsed ^tou^ the 
whole mass, and thus offeiing a large surfiice, 
: qliickly decomposes the water with which it ib 
liiixed when made into mortar, dnd forms 4 h&rd 
subst&nce analogous to the s{)ecula:r iron Aire ; ad 
it does in the iron tubes, in which water is de^ 
cbmpdscd, in Mr. LavbiSife¥'& tad Dr. Priefetley's' 
exper&nents; tdr id these the iron'BveUs add ia;^ 



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^24 JMMAIlt XIL- TOLCMie. 

creases in bulk, Mem. Par. 1781, p. 1877 : and so 
does puzzolana when formed into mortar, Hig^ns 
on Cements, 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^^us particles ; yet, in time^ even cold 
water may pervade it, and produce hardness ; and 
hence lavas become hardei>^when moistened, as 
M. Dblomieu has observed, Pcmces, 417. If 
the mortar be long exposed to 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, over which lava has flowed, is fir6<(tently 
converted into puzzolana. Ponces, 338. But voU 
canic scorise never aflford it ; ibid ; either becau^ 
they are much caldned, or retain siilphur, or its 
add.'* 

" TRASS OR TARRAS. 

^^ I couple this with puzzolana, on account of 
their aimilarity to each other, and Qot because I 
look upon it as qoqstantly, and necessarily, a vol-> 
canic production. On the contrary, I believe it 
to be generally the prodqct of pseudo^volcanoes, 
or es^rpal fires, 

. ^^ It is fpund in many places, but priacipally 
n6$rAp(]lerJ^B^ib, in (he vicinity of the i^^ also 



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VeMB IT. T090. 425 

Dear Frankfort, Cologne, Piritb, &:c. and ti^ere 
called tuffstem. ^ ^' 

" Its colour is grey, brown, or yellowish. 

" Its surface rou^ and porous. 

" Its lustre and transparency, 0,. 

" Its fracture, commonly earthy, rarely lamel- ^ 

kr; it contains fragments ^resembling pumice 
(4ough not real pomke, Voigt I\ilda, 221) ; also 
fragments of argillite and basaltm (siderite) ; often 
bfiadies of trees half cleared, and impressions of ' - ^ 
leaves, 2 Nose, 182. Mica, mm ore, and other 
heterogeneities, are more frequent in it than in 
pozrolana, S Bergm. 196. 

" Il^liardness from i to 7* ^ 

^^ Feels dry and harsh. Scarcely efiervei^cet 
w{tfa adkls. 

^^ It is not diffusible 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 
surfiBtce, to which no streams of water have had 
access. Sometimes in columnar masses of a grey, 
or Isabella yellow colour, son^ round and some 
quadrangular, standing close to each other, and 
forming internally one common mass. 3 Serl. 
Beob. 199. 

** According to Mr. Bergman, it consists of 



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1m * DOMAIK XIU VOLCAVIC. 

Marly the same principles as piizzoiana, only the 
calcareous seems mbr^ plentiful in this. 

'^ Artificial tanras, or J)uzzolaiia, ii made by 
burning clays or slates that iaboand in inm, and 
then grinding them to a fine powder."* 
OdxfkfnL . A red substance is fi>lind in the north of Ireland, 
particularly m Lord Antrim's Deer-park, near 
Glenarne, which has a burnt s^peiirancey and 
much reseihbles the puzzolana of the extinct vol* 
taiioes of France. It might perhaps be applied 
V> ivchitectural purposes. Fmijas, who rendoned 
a»service to his country \n discovering' the pu22o- 
lanas of Vivarais, givei the foUd^ibg observa- 
tionsf* " ^ 

V9tM of : f ^ Puz^oladas are an object df the first htillty in 
hydraulic constructions. We cannot build wi)li 
solidity in the sea, without using ibSs volcanic pro- 
duction, by inixihg it with two portions of lime to 
one of this natural cement, of which a well-uiiited 
mortar b formed. Vitruvius has^ in ids architec- 
tiAe,. devoted a diapter to the origin df tthis sub- 
itaAce^ and the ptoperty it possesses of hardening 
very soon in sea-water, as well as finesh, when it 
has oeen amalganSated with strong lime; it then 

* Klrwan, Min. i. 411. 
' * t Annales du Museum . It is truly surprising that he has omitted 
this important article in his large Classification of Volcanic Sub* 
Irtanc^, GeoUgie, tome ii. p. 401—^8. 



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NOMB IV. TUtO. 42^ 

perfectly resists the corrosive actioD of marine 
salt 

" There are in Vivarais, Velay^ as well as in 
Auvergne, as good mines of puzzolana as those 
of Italy ; and yet we, sii]\ use the puzzolana of the 
environs of Naplesi; which shows. tt^at much timf 
i jiece^3ary to change the ci^topis of qotf n, evew » 

ia the inost simple, thing?/, ../ , ; : 1 

^^ The trass of thie environs of AndenpacH w 
&iSi^ bank of rthe Rbixiey i§ a kind oip\izzo\9m 
feffmed of small fragments of ft)}f^iQie,t and S0»w^ 
species of lavas^ more of lesa.aU^red and ag^^- 
tinated in the manner of volcaj&ic.tnfos'*. Trasfe 
is tem^pbrted by water as far ab Dort, to he ire^ 
duced to powder in stamping m^ worlced by ths 
wind. Trass, ttfm pulveHsed^ cinoufiUes thrdO^h-. > 

oiit£Lelland ; and is uised.widi thi^ greatest. stM> 
cesa £)f all conshructiobs in mdsooiy, in a coudtrjr 
where water is ever^ where found in di^;ing the 
earth: the Dubch also supply Eiigland widk 
trass." : 

* '< I have ^fftten the dcKription oC the qtmrie* of tam tn U|e 
^t number of Annala du Museum, vol. ^" > 



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^<K DOMAUr Xlf. TOLOimiC* 



NOMEV. PUMJCE. 

F«nMrnd(s. This rabsUoce deserres to be ranged among 
the rocks, as in th^ isle of Dpari, whence U is 
^ ' chiefly brought into commerce, it appears in the 
form of large currents^. Pomice also abounds 
HI the smaller volcanoes of the isles of Santarin 
and Vulcanox and, according to Troil, Hecia 
presents vast ifoantities of brown and black 
pumice. The velcanols of Temate, and other 
Molucca isles, also eject such prodigious qaaii«* 
titles of this substance that the ocean appears 
ooivered for many leagues. 

ttkAfhStfu.' Different lavas niay. become )iumice by some 
pecolmr modification o£ the volcanic agents. 
Felspar in particular has been detected passing 
into pumice: and according to the degrees oi 
lieat and o&er circumstances, it may be ipore or 
less porous and lightf. That which only pre- 
sents small cavities may be termed porous; 
while the more last may be styled vesicular. 

* Fatrin, t. S89, from Dolomieu't Lipari. 

t Fenaxa, p. 304i, mentions a laige specimen geded b]f Etna ia 
1808, of which one half was lava, or melted 8iderite« the other 
pumice or melted felspar. See also his account of the punuQes of 
Xipari, p.S15» 



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nom T* FvmoB. * 48§ 



In his visit to the little isle of Iipari» which* 
though only sizmiles in length andfourin breadth^ 
is singularly interesting from the pumices, and 
great variety of volcanic glasses of all kinds 
and colours* which it contains, Sfj^allanzani has 
minutely described this substance ; and the spot 
whence it is exported to all parts of Europe, as * 

it is. useful in many of the arts. On such ocoa* 
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 
bc^t 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,CuBpoBiaMo. 
till I approached Campo Bianco (the White 
Field), distant three miles fix>m the haven of 
Lipari, and so called because it is a lofty and 
extensive mountain, composed entirely of white 
pumices. Wheh seen at a distance; it excjtes 
the idea that it is covered with snow fix>m the 
summit to the foot Almost all the pumices 
that are employed for various purposes in 
Europe, are brought from this immense minei 
and Italian, French, and other vessds continual^- 
ly repair hither to take in cargoes of this com** 
modity : the captain of the ship which had 
brbught me to Lipari, had sailed from Marseilles 



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4S0 DOlCAIir XII. VOLCMflC. 

to carry back a freight of this merchandise. I 
^ Was not, however/ actuated merely by those 
motives of curioatyi that might induce any tra^ 
veller to visit this remarkable mountain ; I pro- 
posed to examine it with the eye of a philoso- 
pher and a naturalist 
OiiciiL <« 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 chemists and naturalists botft 
ancient and modern. It may, in fact, be af- 
firmed that it has given rise to as many hypo^ 
theses and extravagant suppositibos, as tUe 
question formerly so itkncM agitated relatWe *ito . 
thenature of the yelloW and grey amber. ' With- 
out noticing the more absurd of tbese^ I' shaB 
only mention that'Pott, Bergman, and Demeste 
imagined that pumices were amianthuses decom- 
posed by fire ; Wallerius, that they were coal 
or schistus calcined; Sage, that they were sco- 
rified maris ; and lastly, the Commendator DJ- 
lomieu, that they were granites rendered tume- 
fied and fibrous by the action of the fire and 
Bfiriform substances. 

- ^^ The most effectual method to investigate the 
truth in so*" obscure a question, appeared to me 
to make the most accurate and mitmte observa- 
tions on the sj^ot; to collect and atteoM^^y 



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noMB V. pumcB. 451 

caLamtne the pumices most swtable to this pur- 
pose, and to make further experiments on them 
after my return to Pavia^ ^hich practice I iik^* 
wise obsenred with respect to the other volcanic 
products. 

'* Cignpo Bianco is a mountain that rises al« Mountain of 

iNunicc* 

most perpendicularly from the sea, and which 
seen at a distance appears to be about a quarter 
of a mile in height, and above half a mile in 
breadth. No plants grow on it, except a few 
which bear no fruit, 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 havS 
been formed by the rains, whidh easily coirpde 
and excavate a substance so soft and yielding as 
pumice. The sea at the foot of it has likewise 
occasioned great devastations, by means^ of 
which we discovered a large vein of horizontal 
lava, on which the last waves die away when 
the sea becomes calm. The formation of this 
lava was, therefore, prior to the vast accumula- 
tion of pumices which rest upon it 

^ On attentiv^y viewing this prodigious mass tn bedi. 
of pumice, we soon perceive that it is not one 
aolid whole, and forming only one solid single 
piece ; but that it is an aggregation of numerous 
beds or strata of pumices, successively placed on 



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4ft| OOMAIll XII. TOl^CAVIC. 

each other; whieh beds are distinguishable b/ 
their colour^ and in many places project from 
the mountain. Th|y are almost all disposed 
horizontally, and their position is not dissimilar 
to the stratifications so frequently met witb in 
. calcareous mountains. Each bed of pumice 
does not form a distinct whole, which xmght 
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 ajggregate 
of balls of pumice united together, but witbout 
adhesion* It is hence evident that the pumices 
were thrown out by the volcano in a state of 
fttsioD, and took a globose form in the air, which 
theji preserved at the time of their sudden con- 
gelation. We find many such eruptions of pa* 
mices in the Phlegrean Fields ; as, for example, 
that which overwhelmed and buried the unfor- 
tunate town of Pompeii. The excava^ons wbich 
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 difl^nt 
beds or strata. . 

^^ A great quantity of these Liparesepumice8> 
of a globular form, are first met with on the 
shore near Campo Bianco ; but as I doubted 



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whether the action of the wav^ might mft con«' 
cur to pfoduce the roundness of their, figure, I 
rather chose to 'make my ol>ienration8 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 pumiee^ approaching, sotaae more some 
^le8s> to the globular form ; and of difierent sizes^^ oioboiar. 
some not being larger than nuts^ and others a: 
foot or morc^ in diameter, with innumerable sizes 
between these extremes. Though, the ground 
colour of tbem all is white^ in some it inclines 
to yellow, and in others to grey. They swim in 
watery 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 tran^renti 
and their texture in all of them, when viewed 
through the lens, appears vitreous; but this 
texture has diversities, which it will be proper to 
specify. 

** Some of these pumices !are so compact that comptct 
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 appear an irregular accumu- 
lation of sm^l flakes of ice; their compactness, 

VOL. II. 2 F 



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494* DOMAIW Xtt. TOLCAVIC. 

however, does ^t preveht their swimming on 
the water. 

Vwwm. ^^ Others are fnll of pores and vacaities of a 
hrg^r size, nsually of a round figure ; arid their 
texture is formed by filaments and streaks, in 
genetal parallel to eacbodier, of a shining ^Iver 
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 
different globes of pumice, but frequently in the 
same i it is therefore indubitable that these dif- 
ferences Uft not intrinsical and essential to the 
nature of pumices ; but accidental, and arising 
from the aotion of aeriform fluids, which dilating 
them in many places, when they were in a state 
of fusion^ halve, produced that midtitude of pqresi 
and those filaments and subtile streaks that de- 
note a separation, of thje parts; whereas the 
odier puQiices, which have not been actiM on by 
these gases, have presferved that compactness 
which results from the force of aggregatton. 

Fnctm. *' The fractures of the eompaet 'pumices are, 
in some places, shaded with a blaclaah but at 
the same time shining tinge ; wfaidi> when care- 
fully examined, is found to be caused by a 
greater, though still a very flight, degree of ?i- 



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HOMB T. rumoB. 48tf 

trificatton of the pumiee itsell^ either because 
the fire has there acted with somewhat more 
force^ or because the parts were there more 
easily vitrifiable. 

*' The pumices hitherto described^ form one 
of the species which the Liparese sell to foreign 
traders. 

'^ None of these^ so &r as can be discerned hj 
the eye, or even with the assistance of the Iens» 
contain any extraneous bodies ; but were we too 
hastily to conclude that they really do not, we 
should commit an error, as their vitrification by 
artificial means will prove. When kept in the 
fnrtiace. daring an honr, they become only more fiffecta'orbeaL 
fri&ble and of a reddish yellow colour ; but when 
continued in the same heat for a longer time, 
they, condense into a vitreous and semitrans* 
parent mass, within which appear a number of 
small white felspar crystals^that were not visi- 
ble in the pumice, b^aiiro they were of the 
same colour. These lilones, however, are not 
seen in every pumice thus fused ; either because 
it did not contain them, or beqause they have 
melted into one homogenous mass with the pu- 
mice. This is one of the many important cases 
in which we are able, by the means of common 
fire, to discover the composition of volcanic 

S F 8 



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4dO DOMAIH Xtl, TOLCAVIC. 

products, which Rad at first beea 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 ^f 
Lipari, whose assistance was particularly useful 
to ineji as they lived by digging pumice, and 
were well acquainted with every part of the 
mountain, and the different kinds of pumices it 
contaiped^ It is impossible to describe the dif- 
ficulties I met with in these excursions* We 
frequently passed along the edges of the deep 
ditches made by the rain-water, at the hazard, 
V in case of a false step, of falling into them, and 

not easily getting out again ; or the still greater 
danger of precipitdtitag into the sea. The daz« 
zling whiteness of the piftnice, equal to that of 
snow, increased my fears; for I made my ex* 
cursions in .the day time, when the sun shoqe, 
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. 



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that the person who walks on 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 greatest dangersy 
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 
mountain 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 manqer composed of pu- 
mice, I extended my researcnes 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 Vtnctie*. 
a branch of commerce at Lipari, and are applied 
to various purposes. One of these has already 



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458 BOJf AIM XII. TOLGAVIO. 

been sufficiently described : I shall only add, 
that it is found in consideraUe quantities in 
Campo Bianco ; but solely in detached pieces, 
and not forming currents or veins; whence it is 
evident that it has been ejected from the volcanoi 
end has not flowed 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 
sparks with ^teel, and is so light that some pieces 
of it will float oh the water. It is formed by 
agglomeration of pumiceous buU>les, which are, 
as it were, conglutinated togetheri and incline 
more or less to an oblong figure. To defaul 
their various sizes would be useless prolixity. I 
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* 
fneter^ though the 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 i^ white, and 
has some transparency ; but in others is doll, 
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 



. * 



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my dewripfiitin .to be MS fkMt m^ explicit «r 
possible. Jiik>hfi$ boe^ a|neadji!.Mu4» that maay 
lavas, aod.ialb^ vokaoic tMrpdactjons, on re* 
f uaioD> become cellular. Tfx "H^ply tbis . |to i the 
pumice iiiiq»^tioQ, would he an error. A lava» 
which hay uiidkrgpne this ch»oge by the.. action 
of elastic ga$Q3» ^ontiQues to form otie whole» 
though initqrrjipted by Jhese muli^plied pores. 
The pnooice of which I now speak j^ princi^- 
pally foraied.by #n accumulation of $m(tft. vitre- 
ous vesicles,, which attached themselvte tp each 
other whiJe.>they ^ere yet soft from the; action of 
the fire;. and which, from their globose fig!iire» 
not adhering except in. a: few points^t have left 
many vacuities,very viieibLe in the fractnrQ of the 
pieces. The labourers who dig ^hese pmiM^es^ 
after they have shaped them into paraUe|o.pipeds, 
taike them on their backs and ca;rry thAi down 
to the shore, where they pile them up \^ large 
heaps, to be ready for s^e when opportunity 
shall o£Eer. We are not ^ imagine, hftwever^ 
that this species of pumice ,is to be found in 
every part of the mountain: the ||K>rkmen, .to 
find what they call the vein of it, are obliged to 
ifiake great excavations, and jQrequently without 
iruece^ss which^^ they told me, in this case, as 
in fishhig for coral, often depends on chance. 
When they^have fouQd the vein, they dig it, fol- 

'I 



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440 Douktm xn. tolcavic 

towing its direction ; in which laborious em- 
plojmeht anombier of men are occupied for 
whole weeks, the vein being sometimes a Iihd* 
dred and fifty, two hundred, or even three bmi* 
dred'feet long) and large in proportioa* These 
reins are called Feraglionu ^ have es^amined 
them, -and satisfied mysdf that the accounts I 
received were true. Pumice-dost, and large 
heaps of the first species of ptamice, with.some 
scattered vitrifications, usually cover these veins, 
which, when viewed with the attentive eye of 
^ the nsituralisti'give reason to believe that they 
are long tracts of putaiice, which once flowed in 
comnts, a liquid state. Theif bubbles, irequentiy length- 
ened in the direction of the vein, seem likewise 
t6^^rove the same^ 

• *^ M. Dolomieu, who first suggested that many 
pumicef have flowed in currents like lavas, ob« 
served that at Campo Biapco the lighter pumiees 
lie above the heavier i^in the same manner as in 
the common current^.of lava, the porous lavas 
occupy the highest place. I have certainly ob« 
served this ifisposition ; but sometimes it proves 
fallacious : for if the excavation be continned 
below the vein which forms the second spefliA 
of pumice, we frequently agaii| find masses of 
extremely light and pulverulent pumice. 
*' The first action of the fire of ^fae fumaoe 






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thickens the sides of the vitreous vestoles, of the 
second species^ and dimmisbes 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 plentifdllyiiKith steeL 

" The third species is likewise an object of Anottokind. 
traffic with: the natives of the^island, who dig it 
HI the same places where they find the secorid ; 
and, in like miaoner, shape it mto paralldopi-^ 
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 (hat are 
contiguous. Here the elastic gases, investing 
the pumiceous substance in several pointi^, have 
expanded it in every part into tumours and 
cavities, nearly as we see in raised^nd baked 
paste. It is worthy remark, that frequently 
wnan 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 



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444 DOIttfK Jin. . ¥QftOMlIC. 

are iH ladre or kes Titrified ; but ma^y of tbe 
third yhowso signs^f vitrificatiotiy. are esttea^j 
friable, and of a pale red colour. 

^* This pumice^ though destitate of aiijr fibrous 
teztore^ is specifically li^^iter than water. To 
obtain it, large pieces of wtu4^ pumice, of the 
first species, in which it is eii^feloped, mast be 
removed; and it commonly lies in long tracts, 
in the. direction of which its Tesicles are some^ 
times lengthened, which may induce us to sus- 
pect that this likewise, when it was liquid, 
filmed small currents. It contains no extra- 
neous bodies. 

<^ In the furnace it condenses into an obscure 
mass of glass, alosost opake^ but Utde porous, 
and sufficiently hard to give sparks with steel. 

*^ These are the three kinds of pumice which 
the people of Lipari dig for sale. Tbe first is 
employed in polishing different substances ; and 
the other two are used in the construction of 
arched vaults, and the comers of buildings.'' 

From these descriptions the following arrange- 
*" ment naturally arises. 

HYPONOMB f. POROUS PUMICE. 

From Lipari. It sometimes presents small 
crystals of felspar. 
Porous pumice, from Hecla, 



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HYPONOMB n. V^ICULAR P^MtOBk 

From Dpari, Santorin, Hecla, Temate, &c. 

Microname 1. Fibrous Jhlsite. 

This kind of pumice, described by Dolomieu, 
assumes the form of distinct elongated fibres, and 
sometimes occurs with minute crystals of felspar. 

NOME VI. OBSIDIAN. 

This division will include alt 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 puiM 
Castagna is wholly composed ot glass and amels. 
It forms a proniontory which extends 800 fa- 
thoms into the sea^ and which is more than 3000 
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- 

* S«e JohosQQ^ as before mentioned : enamel b properly the ap* 
pUotion of the OMsi to anotfier wlwtincf . 



Iip«i 



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'444 JXniAtir XII. : TOLCAHIC. 

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 water. 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 the 
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 
i Europe. 
Frwice. ". Faujas only found obsidian in one place in 

France ; at CheiBivari 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. 
u^taA. " The volcanoes 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 Galinaxzo, regarded by Cay* 



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ISOMK VI. OBSIMAV. 



44« 



his as the obsidian of the ancients^ is a ?oleanie 
amel of the province of Quito. 

** The volcano of the isle of Bourbon presents 
very remarkable vitreous ejections: they are fila- 
ments of a flexible and yellowish glass> two or 
three feet in lengthy sprinkled at intervals with 
small globules. These threads of glass showed 
themselves in the eruptions of the 14th of May 
J766, 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 Okhotsk, in the gulf of Kamschatka, 
there is a volcanic hill called Marikan, formed 
of a white sand entirely vitreous -, and in which 
are found dispersed, globules of glass and vol- 
canic amel. This very remm-kable sand ap«* 
pears at first view to be shelly ;^ for it is all com- 
posed of white fragments, resembling mother of 
pearU convex on one side and concave on the 
^ther. 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 



Bovboo. 



MtrfluuL 



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^5 ^omum Xtl. TOLOAHIC. 

in mittiatiire, what basaltic balk, are on a kge 
scale. These litUe gldboles are cffpskBp bottk 
coats which form them are perfiectly tmnqMreirti 
«' Thei^ are two other varieties, of globules ia 
the ^ime smd, entirely different fsofn these; 
they are less regulariy spherical, and haw tome 
flat fiaces: their texture is perfectly-solid* md 
Qompact, and their fracture vitreous. 
% '« Some are of a white and transparent glass, 
which seems fr^e from bubbles:, their ase does 
not exceed that of a hazel^nut^ 

<< The others are opake, and formed cf an 
amel mottled with red and black veins ; thew 
are as large as a small egg. . Being afcltkutdn in 
1785, I received from Mr. Benaiog, fonncdjr 
commandant of Okhotsk, a^considanUe number 
of these globules, ivitb a sample of the saoi 
which contains them« V 

" To judge by ariUogy, it might be said tfcat 
basaldc balb were, from the beginniag, fonoMd 
by layers, as they now appear; for thelaiaiiiar 
texture of the globulus of Okhotsk, seems m n6 
wise owing to any kind of alteration : their dm 
coats ccmtinue, to the centre, <rf a perfectly paK 
gl^ss/'* 

• Patrin, V. 292. Fcrrara, p. Sll, 212, may abo be coasM 
for the obsidians of Lipari. He obserres, p. 2Qg, that they are 0^ 
\ infinite variety, and all IbnDed of febpar melted man inteoaehetf. 



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J 



% % 



HOMB ru OlSIDIAII. 449 

The Piedra de Galmazzo^ above mentioned lu^eMtone. 
by M. Patrin^ is a kind of obsidian founds in 
Qoito and Peru; and is so called^ because in 
blackness it resembles the raven. Ifrfseems to 
have been sometimes polished, and Hised' for 
mirrors y but must not be confounded with the 
stone of the Incas, found in the f<^ale tombs^ 
and used for the same purpose; the latter hiring 
a c6mpact pyrites, or mapcasite of the Arab&ns^ 
and other early writers on mineralogy* 

In* his account of the island of LipanV after Ofaisesdr 

lipan* 

having mentioned . several kinds of volcanic 
giaast as the pmniceous, reticulated^ and capil-^ 
lar^, Spallanzani thus proceeds, having apolo*^ 
g^sed for the prdixtty of his description as indis* 
pensiUbly necessatyior the jsake ofaccfuraoy^i in 
discussions merely scientific:^ .: / 

*' 4. The glasses of «he Monte -deUa €aMagna^ simiiaiimi't 

ACCOQOt* 

which we have hitherto considered, are diose 

that have a texture tik>re or less porous; we- Will 

now proceed to those 6( a compactstructure, of 

which kind is the fourth species, which may be . I 

said to compose nearly one hdif of the mcuntaim 

This glass, if viewed superficially, and^M it is 

foimd on the spot, has rather the appearance of 

a red earth than a glass, occasioned by a red 

earthy coating that invests the glasi» dit^posed 



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# 4 



448 AowAxii xn. roLCAMte. 

ttiider it in immenae plates; which doveriog, 
thoiigh in many places it but feebly adheres to 
]t» since it may be removed by simply washiDg 
with wafe|r, in others is so closely united that 
it forms ^he last rind or outermost part of the 
glas8> which indoces me to beliere that it is a 
superficial decomposition of it Beneath this 
earthy coating the glass appears, which is ex* 
%emely perfect, and as if it had just come oat 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 
dive colour, and transparent when in 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 known, when broken, have liieir fractures 
striated, waving, and curved. In this glass some 
of the fractures are .the same; but in general 
they are conchoids, like those of flints. Its con- 
^ r^ sistence is not perfectly homogenous, as it con- 

tains many felspathose points. Its aspect is not 
lively and brilliant, like that of glass^ hot some- 
what unctuous and dull ; from all these <iQalities, 
this produqt appearj^ to be more properly aa 
enamel than a glass; unless we are willing to 



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MOMK VZ. 



OBSIDIAN. 



m^ 



consider it as oue of those volcanic bod|e9 which 
constitute the middle substance between enamels 
and glasses. 

^' In my description of the glaSjpes of Lipari, 
I have observed that several of them aVe'wter-^ 
sected with veins or earthy leaves, by means of 
which they are easily divided into plates. The 
same is observable in the,pre8ent 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 frpm the common mass of tits gla^, large 
plates five feet long, three broad, and two in 
thickness. ^ To the surface of each plate was at-» 
tached a coating of barcl earthy matter, which 
still more confirmed me in the opinion I have 
already given, that this matter had; resisted fu* 
sion^-SLfkd, 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 aome portion of (bis 

VOL. II. 2 o 



Vemdar. 



Jf 



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esLtth, which with dfficuhy fu8ed» thongfa the 
glasd wii» inflfttedy and changed into a finothy 
enamel. 

^ This glass slightly cuts the factitions giass; 
and if the cutting angle of one piece is driven 
irith force along the rarfece of another, it pro- 
duces a white and impalpahle powder. 
25j^ <« 5. This species of glass completely deserves 
\hat appellations since it is not only the most 
perfect of all tiie rolcanle glasses of the Eolian 
isles, but does not in tlie least reject yield to 
what is called the Iceland agate, or the pietra di 
galtna^zo 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 Imvcs are white 
and transparent : the opacity and bladttiess may 
be said to be in the direct ratio of the tiiickness. 
This glafis» which is extremdy compact^ is free 
from aeriform bubbles, and from every kind of 
heterogenousness. It is somewhat harder than 
the fourth species, and therefore cuts factitious 
glass more easily, and gives more sparfer with 
steel. Its edges are sharp and cutting. 

^^ M. Faojas, having obtained tome ^lecimens 
of the best glass of lipari, has made some ob- 
servations on it proper to be given here. He 
ateits'that this speoies is the same with that^of 



.^ 



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moMM yn. omiihav. 451 

Iceland} butfaeKoiarkB»howev«r9th&titdiflfer8 
from it in the polish, which appeared ^o him 
more unctuous and less vitreous, besides that in 
the fractures it had not that waving, striated, 
ioaly appearance, which is proper to the masses 
of true glass. 

^ It must be remembered, however, that the 
specimens of M. Faufas were none of the best: 
the pieces, at least, which I collected, took so 
exquisite a polish and lostne, that I do not be* 
lieve any kind of artificial glass ever received 
one more beautiful and brilliant. This glass, p^'^^ 
beakles, when in the mass, being opake, became 
a true mirrors atid I therefore find no difficulty 
in t)«lieving that the ancient Peruvians used a 
aimUar kind of glass, cut and polished, for mir- 
rors*. This glass likewise could not be broken 
wMmwI exhibiting the undulating scales, lightly 
fCnated, which tt^ French vulcanist aifirms he 
could not find in his specimens. While I now 
w«f|^ I have before me a piece with a recent 
Asetiife, in which these waves are circular and 4 
oonctmricaU occupying an area of two inches ^ 

mmd a hal^ the common centre of which is the 
tilat' Deceived the Wow: they resemble in 
ttanner those waves which a stone pro- 



2 o a*^ 

• « 



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*^*' 



452 AOHAIII XII. TOLeAVlC. 

duces round it when it falhi perpeAdicuUrly into 
a standing water. 

TVuMpmncy. <' I cannot omit another remark. M. Fanjas 
says, that the edges 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, so much inferior as this naturalist 
seems to suppose. A scale three lines and a 
half in thickness being presented to the Aameci 
a candle, afforded, in part, a passage to the light; 
and another, two lines thick, being interposed 
between 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. I have en* 
tered into these minute details the better to show 
the perfect quality of this glass. 
Coioor. «< The opacity of this glass in the mass pro- 
ceeds from a very subtile, and perhaps bitnmi- 

y ' nous substance, incorporated with the vitreous 

matter, and rendering it dark like acloud. The 

I glass loses this substance if it be left for somte 

hours re^melted in the crucible^ and it then be- 
comes white.'* 
«^ Bergman observed that the Islandic glass, 



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when ei^posed to the fire, inelte with diffictilty, 
without the addition of some other substance as 
a flux. In this it differs from the present of Li- 
parij 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 with on the Monte della 
Castagna. It is found only in a few places, 
scattered in large but solitary masses; nor can 
I pretend to say whether these are remains of , 
currents, or whether they were thrown out l)y 
the burning gulfs. 

^* It happens to this glass as to- the difi*erent 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 very 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 Fekpan. ' 
is more common than to find felspars in lavas, 
and scunetimes even in enamels and glasses; of 
which we have frequent examples in this work, 
as well as in the accounts of other writers : but 



S- ^ 



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454 Dfmkim %%u ¥oi,cAiii6. 

these felftptrs are always inserted im^^iatdjr 
into these substances without any intervening 
body* Here, howeve;*, the case ia different i 
every felspar is sorroanded wiUi a rind or coat- 
ing, which, when it is extracted entire from 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^ div€isted of its coat- 
ing, but forming one body with it These glo- 
bules are very numerous, and sometimes by their 
€U>nflttence form groups ; and they are very di»* 
tiuctly visible, on account of the black ctlour of 
the enamel. 
Coating. <* The manner in which this coating waa 
formed around the fekpars, I conceive to be a^^ 
follows: when the enamel was fluid, and ^(^ 
closed the felspars, it acted as a flux to their 
external parts, and combined with them; and 
j&Qpi this combination was the rind or coating 
produced, while the internal part of the fekpa» 
had only undergone a semifusion^ becatioe it was 
not in immediate contact with the enasnd. 
Thcire can be little doubt but that the febpans 
likewise existed in the perfect glass; but the 
heat probably being more active in that than in 
- the enamel, they were completely dissolved, and 
the entire mass reduced to one similar consist- 






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V0«« VI* OftBUPIAJH. 0^ 

ence. Afi a proof of this coqjecture the furoaca 
produced a complete homogeneity of parts la the 
enamel containing these e|;traneous globules. 

*^ 6. When treating of the rocks of the casde 
of Lipari» I said they were formed of a cinereous 
lava of a fe^ar base^ which in many places has 
passed into glass* I likewise remarked that the 
lava, afi well as the large pieces of glass, was 
filled with globules apparently not dissimilar to 
the base« At the beginning of the Monte della 
Castagnaji 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* howeveri 
iias a more fine and shining grain, and its frac* 
ture is exactly such as we observe in glass, yet 
in beauty it is little inferior to the fifth kind( 
and if whiteness, or more properly the want 
of colour, is particularly valuable in volcanic 
glasses (sinoe those which have this quality ^re 
extremdy rare), this certainly has cons]dera.ble 
idaim to our attention : not that it is entirely 
colourless, 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 13 jj^ 
filled form the most pleasing and conspicuous 



Current of 



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f 

456 BOHAtV Xlt. VOLCANIC. 

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 gr^n and 
lustre ; yet, from their uniformity of colour; they 
are less beautiful than 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 surfaces 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. 
Orism. (c But disregarding the beauty which deligiits 
the eye, let us proceed to objects that attract 
and interest the curiosity of the philosophical 
inquirer. We shall find that the cinereous bo- 
^ i^. dies included in this glass are only points of lava 

f^ with a felspar base s and on examining in va<^ 



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♦ 



«« 



KOMB Tt. OB8IDIAK. 457 

nous places the current of this glass, we shall ;^ . 

perceive that it is a continuation of the same ^ 

lava with the felspar base, of which these orbi- w 

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 fbat we find small particles of lava scattered 

through the latter; because it has not undergone W 

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 filament^ 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* 
bides abound, but they are earthy and pulveris- 
able ; every one is detached in its 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 oif 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- S 



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* 

468 DOMilir XI|. TOLCANie. 

^ . servatioQ* which I think to be of some imp^t* 

• ^ ance, relative to the glasses I here ^mit. Several 

|f^ of them have, even in their internal parts, &• 

' snres frequently an inch in breadth, and lliree 

inches in length. These are not entirely vacui- 
/ Fifaunenta. ties, but are frequently crossed by smalt 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 

glass, 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, found in similar fissures in the 
third species of glass. 

, '^ 8. The eighth and last kind of the vitrifi* 
cations of the Monte della Castagna may be 
^ denominated an enamel, that has the colour sod 
unctnooi. lustre of asphaltumy of a scaly grain^ a very 
small degree of transparency in the points of 
the fractures^ and of considerable vreight aod 
compactness, though it is extremely friable. It 
is found in solitary masses^ not very namerous, 
and the broken pieces have the properCy of 
assuming a globose form. Some of these gkbes 
« resemble those found by M. Dq^omiea in the 
island of Ponza. I havebeen favoured with two 



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M 



MOMB VI. OMIOU|r« 45^ 

gf the ktter by the Abke Fortis; butlfind that, ^ 

excepting their gfobose figure^ they diflfer in ^ - ''^ 

every respect from those of which I now speak. '^'^ 

The globes of Ponza are composed of leaves ^ 

orer leaves of an imperfect enamel, do not give 

q>adrks with steel, and contain felspars and mU f . 

pa i whereas those of the Monte della Castagna 

rarely include a few felspars, give sparks with 

steel, have a vitreous appearance, and are 90t 

composed of plates or leaves* . 

** Some pieces of this enamel, broken ^^pd de^ ' ^ 

tached from the masses, are in one part true ^^ 

enamel, and in another Iava% The latter gives a 
few sparks with steel, has a grain approaching 
to earthy, and, as far as I could discover, has for 
its base a soft horn-stone, from which conse- * 
quently the enamel likewise derives its origin. ^ ^ 

^^ These are the principal vitrifications I oh* 
served in my excursions to the Monte della Cas- j^ , 
tagna. Some I have omitted to notice, since, 
some trifling differences excepted, they are es* 
sentially the same with those described. It is 
proper, however, to remark, that more than one 
of them exhibits manifest signs of having once 
flowed down the sides of the mountain, in the Currents. 
thick threads and vitreous filaments they con- 
tain, similar to those we see, on a lesser scale, V 
in glass fused in oiir ^maces, when it comes 



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Googfe 



'" 460 DOHAIN Xlt« VOLGAMIC. 

^ A*^ into contact with the cold air^ as it flows down 

'^'^ . an inclined plane. 

^ *Sm[c?* " Every one "of these eight kinds of glasses 
and enamels may be completely remelted in the 
fnrnace. When speaking of the compact glass 
/ ,:; of the rock of the castle of Lipari^ I remarked 

its extraordinary inflation in the furnace, aod 
said that this tumefaction usually accompanies 
a refusion, in our fires, of solid glasses and vol- 
^ canic enamels. I then had in view those of the 

Monte delta Castagna, five of which, thoagh 
compact and solid, in the furnace swdled high 
above the edges ; notwithstanding that, before 
their refusion, they only filled athirdpartof it." 
These ample descriptions may serve to show 
the precise nature of volcanic glasses, which 
^ >*, ^ome have confounded with the aqueous pro- 

ductions. 

The obsidians, or volcanic glasses, aadame/^ 
may be arranged in the following order. 

HYPONOMS I. VITRKOUS. 

Binnitiei. This can scarcely be distinguished from glass. 
The general colour is black, whence it fonns ex- 
cellent mirrors for landscapes : it sometimes pre- 
^ sents white spots, which are decayed crystals of 
felspar, whence the base^ 8l^)posed to be a vitri- 



%: 



'V 



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■ ■ • ■* f. 

NOM* TI. fMIDIAV. 461 < 

fied trap or basaltiiL The white fibrous veins 
sometiines observable seem also to be of febpar, ^ W 

"which when heated assumes 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 sometimes foiind 
colourless, like crystal. Dolomieu mentions a 
yellow vitreous lava, with black mica and white 
quartz, somewhat resembling pitch-stone, and W « 

'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 beautiful obsidian, in wluch a spangled light 
plays upon a brown base, with an effect resem- 
bling aventurine. 

Mkronome 1. Entire. Common black ob- 
sidian, firom Iceland, commonly called Icelandic 
agate. 

The same, firom Peru, pie4ra dc Galinazzo. 

Bluish obsidian, firom Iceland^ Teneriffe, &c. 

Yellowish, firom Lipari. ^ 

Crystalline, firom Iceland. ^;^^ 

Refulgent, firom New Spain. 

* Dolomiea Ponces, 93, Etna, 509- 



.1 



^ 



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''' 4^ DOMMVXft TOliCAItlG. 



mrroMoifX n. poaPHrminc* 

This kind, spotted with decayed crystals of feU 
ipar, 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 nAier frits than melted. 

*' Obsidian of a very sharp fracture, with a 
number of little round and oblong globules of a 
dull white substance, which resembles amel, and 
which may proceed from a granular ielspai*, 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 fusible; for the glass wluch 
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 this volcanic ^ass 
are seen in which the same white substance^ in- 
stead of being disseminated in the mass, is dis-- 
y posed in small layers, very thin, of the thickness 
of ''half a line or a line at most, which alteraate 
with layers of glass, very black and shining, of 
four, five, or six lines in thickness. This beauti- 



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1-- . 



ftil ^aa6 was distovered at lipari by Spalkm-' '^ 



• 



" Black volcanic glass, rather poroai, enamellad 
with reticular lines of white felspar, which everj 
where penetrate it, and crcM each other in differ- 
, ent directions : the black part is mdted^ the Ca- 
spar is only a frit 

'' On the summit of Mont Meisner, in Hessia, f 

are found isolated blocks, of a large bulk, of this ^ 

stooy substance, whose base is incontestadi)ly vitri- * 
fied; while the felspar has undergone but a slight 
alteration. There is nothing extraordinary in tius 
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 
owei its origin to a porpfayritic rock, whose base 
should be a trap, or a paste of felspar io mass; 
while the reticular felspar of the volcanic glass of 
Mont Meisner seems to differ in its origin, and to 
hft ve had a base diffierettt frdm porphyries. 

'^ The disposition of this felspar, interwoven 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 carefuQy examined them, and I per- 



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464^ 



DOMAIN Xa. YOLCAMtC. 



' ceived their analogy. These last are c<mi|ioeed 
of a white filaceous felspar, which intersects saM 
black aod shining crystals of tourmaline." 

HYFONOBIB III. Wnp WHrTB JIBBO08 VBINS. 

i This kind*is also found in the Italian yolcanoes, 

but the most beautiful is from New Spain. 

i 

^^ ^ HTFOKOMB IV. CAPUXART; 

Li- 
lt appears, from Dolomieu's account of Etna, 

that this kind -sometimes a|||)ears in the large ve- 

■: sides of vitreous lava : but that of the Isle oC;. 

Bourbon, above described, is sli^arly curious. * 

HYPONOMB V. GRANUUUU^ 

"^ Patrin, as above quoted, has described a luUof 

vitreous sand. 

There yet remain two important distinctMis <^ 
vitreous lava. 

> HTPONOMB VI. RBSINOUS. 

-^ ' These have somewhat the appearance of jntcb- 

stone, and Icelandic obsidian sometimes assumes 
, this visage*. They are by many, not improp^ly, 
classed in the next divisicHi. 

4, * The untianslatable Lmdn/acks is more 

- ■ ■ ♦.. 



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i 



VOHB n. GBitMAMV 4g5 

The imnwkable isle of P^ntrilaria, tetweea 
Bitaky sad Africa (the aeoiait Cossura, of which 
thfcre are cmm\ produces a biatk obsidiaa of m 
onctuous an aspect that Ferrara compares H to tba 
liitiniien of Chaldea. It is perfectly opalee, evM 
in t^ this edges; and ba3 numerousirrystals and 
quadrilateral plates of felspar in perfect preserva* 
tkaiy except thatit has a dry aspect, and is stunned 
in Mrae parts. The pieces more free from fekpar 
axe extremely hard, with a ebncfaoidal and often a 
atriated fracture Uke o^omMHi |^s. When mb^ 
they yield a powerfrd aaieU of burnt hair*. 



r 



HWONOHB VU. TOLqAMC AlOi^. 



Faujas, te his classificatlofi of volcanic pro-i>««|CTi|^by 
ducts, ha3 so amply treated iMs curious subject, 
that his account deserves to be translated, for the 
benefit of the English readerf. 

^ When compact lavas, either prismatic or 
amorphous, are fused in a crucible in the furnace 

• jhff. 96#; Q^ortdkcQi^hmmih WouI4 ^ ocpiew An 

f Afmales du Museum : but much altered and greatly enlarged in 
Ae second Tohnne of hts Essai de Geoipgie, Parts^ ISQ^, 8vo. At 
fim tliere were seven, bat now twehre, r.lmicb iojiidiei^tiily clMMn 
and tfoogpl from trifling ^ecu and circiunttances ; wbik tome 
important July tances are onUtied, But there are many novelties, 
and ingenious observations, as usual, in the works of Faujas. 

Tile fHmcr efidoa k pielcntd, fbr the ttasM already ataigpcd. 
VOL. II. . v2 H 



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466 DOMAtV XII. TOLCAHIC. 

of a gla88*house, without the addition of aayflux 
or dissolveot, a fine and shining glass, of the most 
beautiful Uaek, is obtained in a few hours. When 
it is in a mass, this glass is very optice; but in 
breakii^; and reducing it into thin pktes, it is 
found to be%ansparent, but a little coloured by a 
fuliginous substance. 

^' If the substance submitted to tfak experiment 
is derived from a tn^>, the glass . is then of a 
greenish colour, and is much more faranspareot on 
the edges. It may even l^e refined by the assist- 
ance of soda, so as to form a fine bottle glass; 
which does not happen when basaltic lava is used 
instead of trap; for, in the latter iostanoe, the 
substance cannot 1^ blown but with ^culty, and 
;. without success : and the glass is neiflfer good nor 

transparent I know the contrary has been as- 
serted in a work on chemistry ; but experiments 
that I made in the presence <rf well-informed men, 
in 1784; in the glass-house of Sevres, near Meu- 
don, and of which I have preserved the minutes, 
demonstrate that basaltic lava used alone, can in 
no instance make bottles : that it is neither im- 
proved by soda nor potash, but other substances 
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 prodacticMis> pio- 






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IKIMS TI. OB8XDIAN. 46? 

dueed by subterranean fires, this difierence only 
relates to a greater opacity, and a more unctuous 
and resinous aspect which amels possess ; while 
the glasses, of whatever colour, have a brighter 
lustre^ are more crystalline, and seetik better 
melted. ♦ ^ 

'^ Real pitchstones, whatever may be their co- 
lour and their vitreous appearance, must not be 
confounded with glasses and amels: they are 
foreign to thAA4|| 

^^ 1. Grey amel, wijtfa shades of a grey white, Aneb. 
rather greenish, with a fracture rather stony than 
vitreous. Its coritexture, and the vesicles seen in 
its paste, leave no doubt of its bemg a volcanic 
amel. In observing it with a lens, crystals of fel- 
spar, whith characterise its porphyritic origin, are » 
even perceived. This variety comes from Ascen- 
sion Island, where it was collected by M. de * 
Berth, an able mineralogist, who has some fine 
collections of lavas from 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 
resintform lava. Its grain, its fracture, its semi- 
vitreous paste, all indicate its being an amel ; and 
the drystals of felspar, distinguished on polishe4 
faces, announce that this amel owes its origin to 

•-S H S - * ' 



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46ft oomahi m. vdiieAMte. 

^ pDipbyry with a base df Mspar. It is fottad at 
LifMdri. 

^' 3. RedMidi grey ttnel^ opdce, with a fitony 
Iractdi^, haying some t^tioii ta what the Get* 
man mfneralogi^ call porzdlan jMpis ; but it la 
incontestably an amel, sbce the greater part of tha 
T^cfaaens found at LIpaH am perforated with 
|>6r^, and in some parte ^^Mfied; whcMtts jas^ 
pefs are infasible. 
' '^ 4. A bluish grey amel, witli|§i^^^dmiiDg frac^ 

taVe and aa hoBifogenoufl paste. 

'' 5. A greeai^ amel^ opake, shiniD^ <tutam 
(yitreouswidi cirystals of white felspar. ^^^hMi tiiese 
amels eire eat and poMshe^, the crystate are better 
observed, la this class I place the viti^eous amft4 
of Piiy Gryou, in Auvergne, formed in a tel^ 
current cowred with lavas. M. de hi OMte^ 
proiessof of the central school of Pay de Dom^ 
first pointed out this aiiiel. 

'^ 6. An olive-green atnel, of an hoaM^emma 
paste, and with a fracture of pitchstone, of Moata 
Galda in the Vicentin. 

^^ 7. An ameli of a hoindg6noas ptoste, PnA 
pitchstone fracture, of a paie black, wiA vary fitie 
and undulai»)g stones of a smoky grey, from Aaem* 
aion Island. 

^* 8. Vitrebas amel, of a ccNid Uadt or obsidiaii, 
fracture -irregularly oMichoidal. I ^vte Sbei 




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oCobiidiiui Id l^iack volcanic g^asfles*, whMever 
vt^ay be their opacity aad their brilliancy^ more or 
lefis upctupus, or their paste mora or less vitreoua^ 
pjDinded that thdr tianaparency is vwifale qn theit 
^i^ea in the thinnest fractures of these glasses. 
nrhe preceding number forms the tr^nsittoii of * 

black aoiel to the ob6i4ian of the Asoension Island, 
4^ Tenerifffe, at Stronaboli, Vulcano, &o." 



NOME Vn. VOLCAOTC INTRTTB. 

This denomination, as in the other divisionsj^ 
includes those subst^pces which, oi^ ^ ba^e^ pie- i 
sent crystals of yaripus q^ures s and whi9l) haye 
thcaace . often been yaguely styled porp^yrie^^ 
Real porphyritic laya h^ already b^n consi- 
<)^redt under the Nome Compact Laya^ being 
one of the most common appearances of thatj 
kindf and scarcely distinguishable from i^nuine 
porphyry, with a base of basaltin and crystab of 
febpf^r. 

T\^ Wpst; reipafjsiable and lingular volcanic 
iatrite is that with leucite^ a crystal resembling withieadte. 
a white gamet| and at first so named, which 
seems peculiar to the layas of Vesuvius, and of 

^ Obsidian may be of several colours, as already mentiancC 



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470 V DOMAIir XII. TOLCAKXC. 

extinct volcanoes in the Campania of Rome. 
Breislak, an eminent mineralogist, bas miootely 
"^ ^ discussed the lencite, in his interesting travels in 
those parts of Italy : and as the natare of bis 
work rather precludes anj hope of its beiog 
Bi«iiWL*k4^ translated, his accounts of the summit of Vesii- 
• Venfnii. y\j^ and of the noted eruption of 1794^ which 
are more scientific than any other descriptioDs, 
shall be here given ; after premising that Vesa- 
i 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. 
%' ** The present cone of Vesuvius is truncated, 
so 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 



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XOKB YIU VOLCitlilC IMTBITB. '^^'^ 

of its mouth; but occasionally it is much eii^ 
cumbered^ and sometime totally -clogged*, hx 
17^^» the bottom of the fiinnel rose so cohside^i^ f 

ably that it presented a vast plain, onlyl 23 fe^t ' ' 
beneath the brim ; and in the midst, of this pluin 
was another cone, from 80.to 90 feet b^h; with 
^ 9maU crater from whicb the eruptioais pm^ 
eeeded. I ; * 

'^ Braccini has left us a curious descripiion of state of enter,. 
the state of the crater of Vesu?jus, after a long 
sta^ of rest, and before the> grand ^rnpi^dn of 
1631. The whole of it, or^t least its greater 
part, had become accessible. Having himself de« 
Bceoded into the crater, he says he found* it co^ ^ 
Tered with plants and trees, and that a road 
down it was practicably for the space of a mile ^ 
that at this depth a very deep cayeipi was seen, 
which having passed, the way was again open 
for two miles, by a very ste^p, but at the same 
time very safe road, owing to the trees growing 
near to each other. At length a large plain 
presented itsejf, 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 otherifrise than by a very rapid 
slope nearly three miles in length, must, assur* 



i*- 



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47S 99MA1M miU TOLGUMTIB* 

edUy^ have been ikMch braeatsb the levd of^tke 

aea^ Had the gmttoes then bete wished* vhst 

< » AuhI of komritfdge mif^t aot fauve beea ao 

^^pfm^ '* When the volcamo it at rest, irapoon art 
men to ari^e frcnxi the cauldron's briai, or fioK 
the interior of its fiid^ which ire veiy peicepti^ 
ble. It would be difficult to conceive it MjtoiUs 
that thi^f should proceed fronk the intemd fur- 
nace $ that they shodld^ by tortuoas.and bidUaa 
tondaite, penetrate from such It profound depth 
to the suADiit of the cqne : for aU oonfiiied rfr- 
pour seeks for liberation by the shortest rosd ; 
and, OMwe^uebtiy^ . were these derived from a 
aource so low^ they wonld issue fcoai the bottom 
pf the cauldron, which presents ibemaa easier 
pQ3Sage with a samQer mass'of matter to tra* 

• *' If the angle of decent, during t^c^istance of the three miJes, 
Was 60* fVofcn vertical, et 3S» fmm an horizontal line, the perpendi- 
miliar depth, by a pkin trigon«»netiioal pfobkni, mil be fomd to 
have been 79S0 feet ; if, however, the steepness of the decUTLty be 
reduced to form an angle of no more than 2S|*, the perpendiculat 
depth will yet have been 6060 feet ; and, as the height of YenivitB, 
. «bcording to oar author (tome ii. p. 43}» is tmlf 39SS Boglidi Jbet, 
allowii^ the statement of the length of the descent to the pUio, a 
^ suted by Braccini, to have been correct, viz. three English miles, 

or 5280 yards, that plain must have been at least 2000 feet below the 
level of the sea, even with a slope o^idesc^M of ototy SBi*; but ill 
slope of 30* be ollowtd, it will have been 4000 English leei bolow 
the level of the sea ! Traksl." 



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I 



verse. It is therefofd iprobtiUe ikM thede fulnes 
are the prodaotioii of fiubiiai«K)es» io the oeigb* ^ 

bourhoed &f the brim of the cwter, in a stAte of ^ t^. 

decompofiitKin. *. 

^« ^Wben ^e aiotttb. of Veiurite is obsenre^y||^ *^ 
from any tjiatauee^ and during the prevalence of 
moif tore in the atmospheae» a mass of Ta|K»w ^ < 

seemt^o rise fr^m it w^h mingles with the f 
clouds. £nti!kly distinct from any volcanio , 

c^use, these are only the hnmid vapours inihe air» Vj 

attraqted by the conical shape of the t&o^Amm^ ' 
and imprisoned in the vast loavity of tbe oatil^ 
dron. Vapours which spring from, or are 4ii^ 
fused over a plain, are dissipated by the air and 
winds; b«A when endosedt' they are much less 
readily cli^persed. 

^^ The western po>tion of Somma mnst be odn* somnn. ^^ 
sidemd as connected with the cone of Vesnviss^ ^^ r 

by a hill of smaller eminence^ denominated 
M$nt€ Cantanmis On which is tbe hermitage del * 

Salvatore. This. hill is intersected by three val-* TaOeys* ^" n 
leys that deserve to tie exainmed with attention^ 
on acconnt of the quantity of primitive sub- ^ * 

stances which the volcano has thrown thither^ ^ 4r 
during old eruptions. The northern valley is ^' 

that termed La Fossa di Pharaojie near the plain, • * 

and Vallone deUa Vetrana in its more elevated « 

part, where the current of lava flowed in 1785. 



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474 DOMAIir Xlf. TOLCAVie. 

This vale, hollowed by rains, is the only interval 

between Mount Somma and Mount Cantaroni. 

South of this vale are tVfO others nearly parallel, 

the first called Rio Cupo; the second Fossa 

jf' mfj£rrandef which taking a direction from esst to 

west, merges in the plain of Saint Joiio. Its 

northern side, nearly^ perpendicular, rises to a 

^ considerable height above the valley^ an^bdng 

composed only of lapillo*, pumice, and other 

"^ substances of an inadhesive ifuality, is subject 

^ frequently to crumble- and fail in lai^ge quantities. 

Along the whole extent of the southern side, at 



.*» •* ^ 



* 



its upper part, is seen an ancient carreot of lava, 
which at first sight appears to be several strata 
f"^ of lava im]^»sed one on the other, but which a 

Vv little attention shows is but one current, in 

which horizontal chasms have been occasioned 
by refirigeration, . and into which the wind has 
^nce introduced a slight quantity of v^table 
earth. This lava is hard and compact; it con- 



4H 






* " This is the denomination g^ven to fragnaents of fninkt^ the 

laigest of which aie from six to ei^t millimeten (a quarter to a third 

of an inch) in thickness. It is of this lapillo, satnqrted with hme- 

|ft Mf ^*^ter and wdl beaten^ that the floors and terraees i^th^^ioam are 

? made at Naples. It is spread in a uniform manner about five or six 

inches deep^ and by beating is reduced to the thickness of two to 

I twro and a half inches. It then becomes a body of suffideat solidity 

to be unpenrioos to water^ and so hard as to bear being hewn like 

tulb.'* 









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HOMB Til. TOLCAVICnmilTB. 4?^ 

tmiiis bat few fragments of aagite or pyroxeo^ 

mmA seems to be an assemblage of leucites, tha kadtou 

siiperficial crystalline lustre of which, having 

been impaired by decomposition, makes it re* 

sembte yariolite in its exterior. Many detache^. ' . ' ' 

masses of this current have fallen to the bottom 

of the Talley. Each fall' of matter brings down 

cmicareous stones, mica, mixtures of felspar, and 

idocrases. The lava of 1767> which threatened 

the villages of L# Barra and Saint Jorio, dis? 

charged itself into this valley, which it filled t% 

a certain height, and afterwards flowed, spvead* 

jBg itself, to the plain. As it is.«Jiff«ady covered --^ ji 

by the cnimblings from the flank, in order to 

OLamine it the inquirer must repair.lo the plain 

of Samt Jorio, in the neighbourhood of the cha« t 

pel of Saint Vito. Its grain is cr3rstallised but * *^ 

fine, and oftentimes so close and compact as to . -' 

be nearly equal to petro-silex. It contains ipany 

small crystals of pyroxene, and fragments of 

lencite, which is rarely found in its perfect form 

of crystallisation • « . • 

'' The lavaofLaScala passes beneath the gar- ^2Jf ' . 
den oMa Fa^orita. It is of ^jie colour of ashes, 
whitish, and of a crystallised grain. It coiitains 
many crystals of pyroxene, few of leucite, and « ^ 

small pieces of felspar, in groups in its cavities. ^ * f 

This lava, wbere it is hewn on the aea«shore near 

I 




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476 OOMAni XlU TOLQAVIO. 

La Cavalkria, is worthy of aMenticm« Under a 
tiAifonn 6ei^' Irom 15 to 90 feet in thicknctt, ths 

iBstni«i. lava is found divided into ftrata of from three U 
four feet: these diTisions are formed by paraM 
and horizoatal lines, and where these asp dug 
down to, the lava is found to have separated itielf 
spontaneously into beds. Below theat are large 

P>wu* J^risms, commonljr hexagonal, which are dtsfeioed 
with great eas^i in some places these prisms, 
instead of the Jower are fonncUpi the m|q>erpart 
of the cuncnt.* Some of these large pmois I 
hav^ seen, the summit of which was parted into 

i'^ '.-i^ a number otdyll pufisms. These observations 
sufficiently demonstrate that the reoessienof the 
matter of tke lava, when in the act of osoliag, 
is the sole cause of the form, whether even ot 
prismatic, which it assumes ; and that this cause 
is capable of giving to lava the appearance of 

^^ s|«atificatioa. This phenomenon may aflbid 

'jf ground for reflection to those geologists who fo 
f*- strongly insist on the fact of horizontal a# ver- 
tical beds of granite, as affording a proof of 
deposits being first made in a floid, and after- 
wards diverted ftfim itheir pristiner p9ln|ptm. I 
am far from inclining as yet to adopt any ge- 
ological ftystem whatever; for, in mjn opinion, 
- we have not hitherto collected a sufleient num- 
ber iof fiftcte to produce one that will bear the 



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mt of i^Mon. I mei^ely gvn nf observatioMt ik 

itrilili ike reflectiiym the^ luggul^^OeotogisIt I 

are not yet of one ofimon reflpectnig the strnH^ 

fioatum of gmxA^y atoiMMgh k andean to be ^ ^ 

deaii^ demonstrated by the ob9erva(;i«nB of Sai^filr 

mte. AdMtting, however^ the truth of the pio-» t *"' 

}A&Skp Mlid veasom vmy thence be deduded fot 

believing that the circamstance is more indebted 

for its eaoBStence te a state ef aqaeons than to 4r 

oneof igneom^ftejjj^^: facie, however, isa^ovu' 

rent of havd and coaBpoct hrra, whioh mo|ft 

assuredly has undergcme a state of igneous 

fluidity, and to which reAllfmitiaa has gi wn an 

horizontal stratificaition. It may be objected, « 

tiiat granite jfamnschaans of imflftensemoantaiaii^ || ^ « 

and that this is bat a small current, searcely a ^ ^ 

tern yards thkk; but the phaxunenoB is the c^^ 

same: the difierence between great and little, 

howorer matemsd with us, hefaig nothing wyth 

nature, *%|*to 

^ "1^ eemeimdracy to a boedlic conforma- iNl'^^ m 
tion, wUeh is noticed ieitlK lava of iASJMia, is "^'' 
ebserred agaia m tiie tteigUKMicinig emrent ef 

Calastso. This, after ]iassing through a defile of cdaftro. ^ 

below Valklonga, spreads to a broad front 4ni \^ ^ 

leaching the sea. What most deserves obs«rva«- ^ ^ 
tkm in the kva here, are the small oryBtaKsationa «^ 

it presents, ^iok seem to be.the olivine ^Weo^ 



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479 ^ ^ nlKAiv xn. toloavio* 

- * ' * 

^A J r ner. It is> moreover, of a deeper iM^ouf than 

Jjk^ the lavaiioi|^j^ala» more porous, and like ttnl 

cotttaiDs many crystals of aogite^ and {ragmenU 
^ oC 6itpan ^n an excursion to the gulf of Sa- 

i .terno, the sn^ o£ its shore, and more especial/y 
* that ^ the coast of Amalfi, presetted similar 

crystn in abundance, as Wi^.as augites, both 
substances indigenous of this country, wbither 
^ itjs unlikely tb^ should have been transported 

; fr^mi^ Vesuvius. A. rock :of a similar kind also 

may. possibly . have supplied that rdcaiio irith 
theioi on one of its eruptions, 
lata of it«. <« Next to this lavtt' is found that of the emp- 
i'i$ tioftofl794. Of the different eruptioQsof'Ve- 

N . |t mvisLs this is the most recent, and was "oue of 

,^i>y, the most considerable. Having ftad occasioii 
to observe it myself, and trace it with atteatioB, 
it possibly will not be displeasing to my.*reader8 
that I should present them with a descriptioD of 
f jifk ^ it in this tdace 



•tr 



ijg^ ^ it m this {dace. 

ll^grfl €€ Vesuvius had continued tranquil iS^ long 

I 



time. ' On the ISth June, 1794, towards deven 

in the evening, a very violent shock of an eardi* 

quake was frit, which induced many of the tn« 

* ^'_ habitants of Naples to leave their houses for the 

"^^ night. The tranquillity of the mountain did 

not however appear to be; disturbed eitfeir oa 

^^ the.lSth, i4tli, or.Uith,.nor.did it exhibit anj 






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NOMB TIT. TOLCA«IC IW4fKl4. 47d 



♦f*** 



'^. 



symptom of an approaching ernption ; but, t(v 

wards nine in the evening of the fcMNtay, many 

sjmsptoms were manifested; The honses aboift 

the mountain experienced violent 4|ock9jFiiiAk shociu. 

gradually increased in forces a very powerAiji » 

one was felt at ten o'clock in Ni^es and its.eift- 

^rons. At tHis instant, on the westernliase of 

tfie cone, at the spot called La Pedamentina, and 

tnmi the midst of ancient torrents, a new mouth ^ 

disgorged a stre^ of lava. This opening^ ms istaeofkTt. , 

237^ feet in length, and SdTih breadth. Scarcely 

had the stream of lava begun to flow, fa^ore 

four conical hills, each tetving its small crater 

{0i third alone excepted, which had two dilAhot i^'0^ 

moiitfii), arose out of the stream itself. From f;*^ / 

these different mouths stones were darted into 

the air with great noise, and in a state so highly 

igaited that they resembled real flames ; the ex« 

plosions indeed were so quickly repeated that 

they seemed but one, and formed a continued . ^tfk% 

sheeMof fire in the air, which received no other • *! * ^ ^- 

interruption than what was occasioned fiy the 

inferiority of the force of some of the ejections. - | -9 

They sometimes vomited substances, I may say, 

in a fluid state, for they expanded in the air like . , 

a soft paste, so that one niay imagine they wer6 

ritlyntp part of the runnmg lava, or i^asses of i^^- 

olcL%(va ftts*d and prqj:ected. Some of these . ^ ^ 



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AW 19911 AW Xih TOLOAirie* 

'l||^^f iuHs were contigvcmB one to tbe otber^ «itt 

aeems as if Ibe force by which they were p^ 
dnoed had met with obstmcikm to the Asgorge' 
miMA<f£ the ttibstanoeB at one poitit, and conse* 
qaently effected aeirerai issues in the same Une. 
The lata flowed in one body fi>r some tioie, and 
at hUerrals flashes of Kght arose fixwi Ae sar&tt 
<tf it, prodficed by jets of h3rdrog«Miis gai^ wbiA 
disengaged itself from tbe lava preeiaely in die 
saoie manner as the gases expanded flpom die 
Direction. * mrfiace of a flnid. Its first direfciion was towaidi 
Portici and Besimif €0 that the infaabiiaatt of 
Torre del Greco ahwdy hewaiied 4he &te of 
the^laeighboncs, and began their thankigivil^ 
to the Afaaighly for their escape. Collecftlto*- 
gether in the chareh, they were stii Biagiiig 
hymns of joy, and expressing their gralitade^ 
when a voice annoanced to then the fttal eem 
of their adtered destiny. The «tMam <tf laia, on 
flowing down a declivi^ it met in itsna^Ti dif 
Tided itself into three branches ; one b^nig la* 
wards Sta Maria de Pngliano tr a v erse d aspaee 
of d06S feet; another, dR>eetn>g ita oomrse to* 
wards Resina, flowed to the dtatanoe cf 5111 
feet; while the remainder of the stiienm,61iiag 
into tine valley of Malomo, flowed towards la & 
Torre. On reaching the chapel of Ba||||oit < 
formed a branch towards %he aouthNeast, niifib ] 



•• N 



♦* 



i ' 



« 

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% 



NOMk VIK VOLCAMie IMMItb. 4g] 



tetmitiated ih the tettitoty €il Antallo Tiron^j 
after hftvingf ran the length of 14i90 feet; tii^ 
residue of the laya^ ptihiuitig ite couroe, iowed 
upon Torre^ presenting a frotit from twi^eid 
fifteen hutidr^ fe^t in brendth, and filling s^toj^ 
deep rayin^s« 

<^ On readbltig the fii^t hoaxed of the tomiDestrwTMn 
the stream divided^ adcoi^ing 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 fir^; accidents which bear rela^ 
tion to the.site of the manufactories^ the thick- 
neMk of their walls, and the manner in which tftey 
were assailed by the lara. Had not the mass of 
the stream suffered a diminution, from the differ^ 
ent divergencies noticed, not a single housed 
wonld have been left {Standing in Torre del 
Greco. The lava, after a serpentine eoufsf^ 
through the towni at length reached the sea-< « 

shore« The contact with the water diminished 
the speed of its course : still the current flowed 
into the sea in a body 1127 feet in breadth, and 
advanced into it a distance of 36S feet. Its en« Entrance into 
trance into the sea was not marked by any sin- 
gular phenomenon ; it began to issue from the 
volcano at ten at night, and reached the sea« 
shore, by four in the morning; continuing a 

VOL. II. 2 I, 



••^^•/. 



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48S Mtomkiw XII. voLPAwie«> 

very slovr progreasive aioreinetit into tbe 
throughout tbe whole of the IjSth, aud. the ftd* 
lowing night. It was conceived that the sodden 
caoling of the lava in tbe sea would have pro- 
duced a basaltic construction; but it became 
firm without assuming any regular form, an 
effect which possibly is to be ascribed to the 
heap of drosses with which it aboiuided*. 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 1 111 ; and 
at a medium, without risk of any great enror> it 
may be computed to have been 725 feet lm>ad. 
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 itsnean 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 1^869^627 cubic fathoms. 
CmruiiioBt. 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 cxplanationi of Ferian air better. P. 



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Ctmi.ali and aoeoBppiattied bjr a hollow nmsoj 
similar to tbat occasioned by a river falling into 
a sabterranean cavern. The lava at the time of 
its being disgorged, from the impetuQQS and un* 
intermpted qianner 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 
iBOtion ceased, and was succeeded by distinct 
and repeated shocks. The fluid mass, diminished 
in quantity, now pressed lei^ 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 pf which are succeeded by rumbling sounds 
which gradually die away. 
' f' 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 
pearer view of this great operation of nature^ 

3 xS 



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and to Ipfofe the truth of tbe opiftion geueuMy 

received, that gMUt ^raptions are accompaniei 

sjwmig^of hy extrftofdiftaiy ph^ontena in the sea. A 

more grattd spectacle there coald not be. On 

one of those serene and brilliant nighty known 

only in the delightfnl climate of Naples, a taa^ 

jestic stream of fife, 11,868 feet in length and 

1488 in breadth, was seen at the foot of Ve^u- 

Tins. 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 

tnoon, the shining silvery light oTwhich was en« 

feebled and obscured* The sea agidn 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 the summits of the houses^ 

the ruins of the buildings, the nvise of the falling 

palaces and houses^ the rumbling of ttie volcano^ 



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HOMB ru. VOLCAHIC INTI^ITS. .49^ 

jthese werQ the principal iocideots of tlii$ hoiv 
riblf yet sublime sceo^^ The ruin^ qf lfompm»p 
buried beneath heaps of drofi3e3 and powdera» 
did not certainly present a spectacle near 9« 
striking. To these objects, so powerftiHy cal- 
culated to fix the seii3ef» was added another 
which forcibly touched the heart; this was » 
doleful group of fifteen thousand persouSf ber 
waOing the destruction of their city and prop 
pert7> who bad had but a moment's notice to 
flee» and abandon their homes for eyer; and 
were reduced to become wanderers, and dfr 
pendent on the worid for refqge. 
'* About dawn the summit of Vesuvms ceased ^^ ^ 

powoen* 

to be visible ; it was covered with a thick cioud, 
frequently furrowed with lightning. This cloud 
gradually spread itselff 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 
^ght of the fire of the volcano* The sun, as it 
appeared above the horison, presented a still 
more dismal piciture. From the abundance of 
ashes in the air it seemed more pale than during 
tht 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 clear, while 



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486 nOHklV %lt. VOLCANIC. 

the light at Naples was fainter than twilight ; 
and with Pliny the younger one might have 
said ^ /am dies alibi, ilUc nox omnihis nigrier 
densiargue.** 

seacaiBu « During this mournful night the air was per- 
fectly nnagitated, and the sea calm : it was not 
disturbed even in the slightest degree^ at least in 
the gulf of Naples. The slightest action of the 
volcano on it would have been perceirtible 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. 

A»II*f " 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 430uth, and descfended to the spot 
called Cognolo; there it fortunately found the 
valley of Sorienta^ 65 feet wide, 121 deep, and 
16<7 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 



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VOUB Til. VOLCAKIC IHTRITB. 487 

three branches ; one proceeded towards Bo8CO» 
amrther 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 i^eed with 
which it flowed must have been considerable; 
and a portion of its mass preserving its first im« 
pttlse, naturally fell in this stnall stream, in which 
were four mouths in the shape of an inverted 
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 suffi« 
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 I 



i 



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^^^ Aod wlml powerful exertion of strength snurt 
bure l^eea required to break thraqgh the moon^ 
^itt ia these two opposite directions ! The hfv^ 
ngUfttfd b^ the expansion of elastic fluidsi made 
its fiiist effort to liberate itself on the eastern 
^ank, and fouqd a passage ; but the resstancs 
it met witii from the mountain^ no doabt occar 
si<HMd its reflux^ or rebound, against the opposite 
ftank. The western current, taking its departure 
from a more eleyated mouth, more quickly ter« 
minated ite course; but the cauldron chieflj 
emptied itself by the eaatern <^dniiig. The iara 
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 i^ompressed by the total mass, 
whioh was already greatly diminished. 

A^^ <( On the morning of the I6th the lava oessad 
to flow over the virestern side, and the mouth of 
the volcano began to resmne 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 distioguisbed 
im Vesuvius, which was wholly inaccessible. In 
this state it c<Hitinued four days, during which 
many shocks of earthquakes were felt, and loud 
^^i^ daps, of thunder were heard. Thunders raged 
in every part of the adjacent country, and the 



V 



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1ltQU% VW TOLCAVIC UiniTB. J^Q 

^Mbtt of ligfatping by which they were acc<mi«> 
paoiedi at intervals for an instant, allowed a iriew 
of the moutM^n, throngh the darkness in which 
it was involved by the rain of powders. This Dvkmm. 
darkness was so prodigiously great»thatat Caserta 
{ind other places, ten or twelve miles firom Vem^ 
vwi it was impossible to walk the streets at 
ai|d*day without torches, and that circumstance 
was renewed which is rdated by Pliny on the 
occasion of the eruption in the time of Titus^ 
^^Jaeu nmU^t variaqw lumna^ sdoebofit obscuri^ 
fsiem.'' 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 
fbfierent in different places, according to the di* 
rection of the wind ; it is however computed, on 
the base of observations at different places* that 
fourtemi inches and siK lines in depth fell on an 
firea, the radius of which is three miles, the sum^ 
mit of Vesuvius being the centre. 
^' It would be erroneous to conclude that all RnmortiM 

enter* 

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 belpw. A rain 
of ashes, when continued for any length of time, 
is very injurious to vegetation. Lands which^ 
a few days b^ore, presented the most smiling 



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fertile. 



490 BOMAm sii. voceAvic« 

aspect^ and were enriched with every kind of 
fruit, assumed a similar appearance to what 
would have been occasioned by the sharpest 
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 suc- 
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 emp* 
tion, they form a pa^te which, coUecied on ve- 
getables in great abundance, destroys by its 
weight their more tender organs, and bends 
down their branches, which either sink or break 
under the weight, according to the nature of 
their fibres. They moreover form, especiaJlyon 
leaves and fruit, a crust which absorbs a greater 
degree of caloric than them, and retains it a 
longer time, thus preventrag the transpiration 
of the plant, and destroying its economy. 
Termoito « J merely use the word ashes to accommo* 

UDproper. ^ 

date m3r8elf 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 the 



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KOMB ril. VOLCANIC IKTRITE. 491 

future to distingaish it by the name of volcanic Volcanic 
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. AH are 
not alikcj some being of large and others of 
smaller size. The grains are often of a dark 
grey colourj inclining to black; sometimes^ and 
especially on the last days they fell, they ^ere 
of a brighter ash-*colour. It is constantly ob- 
served that, when the yolcanic 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 lull 
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 ov^r fire effuse a perceptible 
smell of sulphur; others, lixiviated, yield a mu- 
riate of soda or ammoniac, or the sulphate of 
iron ; and often two or even the whole of these 
salts are produced from the same sand. The 



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m 



StiteoT 
fttmotphere. 



Barometer. 



Bncfa't 
accounts 



OOMAIM %1U VOLCANIC. 

earthy matters which predominate ar^ argil aod 
ulex. 

<* It might be imagined that the pheoomem 
pf this eruptioDy and especially those wbicb took 
place from the evening of the 15tb to the iOtb, 
would have a considerable influence on the at- 
mosphere of Naples, yet the meteorological ob- 
servations, communicated to me by the astrono- 
mer Cassellii prove that the barometer bsd ex- 
perienced no material alteration. Casselli made 
use of an English barometer, divided into iochei 
and hundredth parts. F^rom the Uth of June 
to the 15th it maintained iteelf between 29ySi 
and 29,58. On the 16th and I7th it was sta- 
tionary at 29,60. The 18th it varied from 29,5$ 
to 29,62. The 1 9th from 29,^ it rose to 29J$t 
The SOth it stood at 29,46. The 31st between 
29i^ dnd 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 Lametheri?, wbo 
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 ?» under the title of Camideratiom $w 
k barometre, in which I found the following 
passage, which to me seemed curious : * Vesn- 



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' NoMfe nt. TOLCAKie tirtiin. 4^0 

TiQfi ia 1794 iteuied as if about to engulf all na« 
lure s 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 atmosphere ; vivid lightnings flash- 
ed in everydireotion, and the atmosphere denoted 
an abundance of negative electricity, never ob- 
served during the reign of tranquillity ; torrents 
of rafn committed dreadful ravages on the fruits 
of the industry of man; and every meteorologi-^ 
cal instrument underwent the greatest alteration, 
the baromdter alone excepted; this, like the sage 
among woridlings, 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 imaginable variation of 
this instrument/ 

" At length the rain of volcanic sand having 
ceased on the 20th^ and that which was spread 
through the atmosphere being dispersed, Vesuvius 
again became apparent; but its appearance with 



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494 OOSIAXN XII. rOLCAKIC. 

Fin Of the reason occasioned surprise, for its snmmit had 
fallen iii| and its mouth was oonsiderably en- 
larged. 

^Mv « Considerable eruptions evolved from it of an 
entirely diflferent nature to those by which tliey 
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 thenuselves. When the sun 
shone on them their irregular e^es were of a 
whitish colour. In the J>ody of the clood were 
discerned substances of a greater specific gra« 
vity, which fell down again, unable to continue 
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 voiu" 
minous clouds,. continually fed and renewed by 
those which issued from the crater; and wlach 
rose to a height continually increasing till it 
exceeded that even of the mountain itself. These 
clouds were composed of fragments of ancient 

ordroiwt Java, and the rubbish of drosses and volcuiic 

•nd sand. 

sand, projected into the air by the force of the 
explosion ; and as one eruption scarcely waited 



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HOMB VII. VOLC4NIC IMTKITE. 495 

another, the immense quantities o( stones, which 
struck against each other in the air ; those which 
fell back into the cauldron, and those which from 
a prodigious he^ht fell on the external walls of 
the volcano, produced a most frightful uproar. 

'^ Such was the state of the volcano to the^ 
5th 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 raios 
sant, and mostly so violent that it laid waste the 
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 
^vith 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, 
and 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 world. For the space of a fortnight its 
unfortunate inhabitants were in a state of un* 
certainty respecting their fate, and were repeat- 
edly forced to abandon and flee from their dwell- 
ings, in the very dead of night, to preserve their 



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^^ DOMAIV ZIl. TOLCAlTlC. 

lives. The at>pe«rMiee of the (unalkst ctotid 
occasidtied getietal <:eti8ternalioD« 
Mcphitic M Kor did the seriei of oabifiities which ac- 
compailied this fatal eruption tenniiiate hete. 
la different parts around the mountain, povrer^ 
All murtheronii vapours, of a mephrtic nature, 
were eichakd. These manifested themselves, 
not onl J in the greater part of the cellars of the 
houses of t'ortici and Re&nna,btit spread through 
the oountty) carrying desolation in their traioi 
and destroying all the trees, which then were in 
the finest state of vegetation. They showed 
themselves in the different roads cut to ascend 
Vesuyhls, and occasioned theie the death of a 
nnmber of animals, and even of some men. It 
was certainly a most aflfficting scene to heboid 
vast extents of ground in the highest state of 
culture, which fortunately had escaped 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. 
fSdp^t^ '* ^ ^^^y extraordinary phenomendn, 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, ^md causes even 
the roots of other plants and trees to perish in i 



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NOMH rtl. VOLCANIC tlTTItlTi. 497 

few days, ft neither injnres the olive nor the 
pear-tree, which, in the midst of the general de- 
struction, constantly retain their verdure and 
strength. This is a fact confirmed by all farm- 
ers, and which I have many times verified my* 
self. 

** On examining this mephitic gas by the or<« Ou, 
dinary means, I found it to be composed of car- 
bonic acid gas, azotic gas, and a portion of sul- 
phuric acid, as is sh'ewn 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 carbonic acid to the vegetable reign being 
known. 

«* The colour of the lava of 1794 is a darkish tavaofir^i 
grey, its hardness such as to yield sparks with 
steel, its grain coarse and earthy, its fracture ir- 
regular, its porousness various, for in some parts 
it is so compact as to resemble petrosilex in its 
grain i on moistening it, even by breathing, or 
on being wetted, it exhales an earthy smell: 
finally, it powerfully answers the magnet. Sel* 
dom is mica found in thi« lava in laminas, but 
often in groups and small united masses; on 
these occasions it presents the same phenomena 
as in the lara of Granatello. The lava is rich in 
augite, which is frequently seen crystallised in 

VOL. ji. 2 K 



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itB cvf iiie99 m^ often tjUo iii|temi«eA wilbmoa* 
Near tbe 4>ri6oep «f tbe voIqaq^ 4el4M;lMi ory*-* 
UiU of augiiie are ^und. in «b«odMO« ; tb^ be* 
Umg to tbQse dros«e# «•<) fioroivi lar«» wlH«bibo 
violence 9f tbe frtpoiu«» ia th» vioimty of die 
mouths^ has decomposed without affecting tb# 
Mgite/' 

From the description of this cetebimled vol* 
cano it i§ npw proper to paas to ita moat pecu* 
tiar production. 

BYPOVOME U LKVA WITH UCrCTTS. 

This aboyud9 in the nei^boiurhood of Yesu* 
vius, particularly in the more andent eruptions ; 
ofTmp^ and the streets of Pompeia, built when i^ wl* 
cano waj» e^^tinct, were found to be paved with 
this Uyj9^ Breislak employs a chapter in the dis« 
cnssion of leucite, wluch is common in tfao an- 
cient lavM of tb« territory of Naples and Borne*. 
There is «a iQunense quanti^ of lendtes in the 
Altaic. mountMMi of Albaqop Tivoliy Caprarola, Viterho^ 
Aqnapeodeotet Civita Castdlana, and Borgfietto* 
Tb^ Q^ ocQur in compact lava, sometinies in 
the vesicular, v4 evap in tho drosi^ which dt* 
Qouipoaiwft leav«» the crystals separata. Tb^av^ 
fouwl v» th« QaJicAreou9 roclw of 3oiH»a^ vrbid» 

^ Voyage dans la Campanie, tome fl. 



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Soitt'ttJi YOLtAHUi HttiilTE. 4^ 

fliaj h^ tegit^^ a£( fragments of a prkuhftt 
rock, ejecMd without having undergone the actietl 
of Tolcaoic fin^*. Leacites are often conjoined tfith 
febpffir and aogite ; and, like topaz, ttte earth of 
leucite may oectir uncrystalliied. 

HYTOfJOMB IT. LaVa WITH CAL^ARlftOt^S SfAR. 

Accordu^g to Ferrara, odcareooa spar abounds vemnts 
hx the ancient or rather primeval lavas of Sieily^ 
Though the doctripe of infiltration begins to yidd 
to that of contemporaneous sublimation by beat| 
yet his arguments in favour of the former bapre 
great weight; for when he afterwards menticms 
the zeolites found in the same basaltins^ and the 
analcimes of Haiiy, (which he proposes to call cj^ 
clopitiSf because they were first found in the rocks 
of the Cyclops^ and appeared about the middle of 
last century in the cabinets of Prince Biteari^ tod 
of tbe Benedictine monastery,) he observes, thftt 
'^ this substance has not only mfikrated and ciys- infiurated. 
talised in the most interior recesses oi Ibes^ enor^ 
moas masses of the hard lava^ bat in a g|eat 
quanlit)r in the slits> and in the middle of the mad, 
which forms a stratum above all these lavas; a 
convincing proof that its origin ia posterior to the 
liquid state of the lava, and foreign to that sub* 

SKfi 



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300 PouAiu xu. voi*cAirie 

ataooe*/' That even ^e hardest metak and 
other substances have pores of extreme minute- 
ness, undiscernable by the best microscopes^ is a 
^eil koQwn fact in natural history ; and ^ses may 
penetrate where the purest water may beexdiided. 
^^ Calcareous spars, or crystalised carbonate of 
lime, is the most abundant substance in these an- 
cient iavas. It is sometimes confusedly crystal- 
ised like stalactites, and like them '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 
moyntain of Carlintini ; and behind Tjentini, 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- 

• Fm. 134. 



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KOMI Til. irOLOANiC tNTRITB. JjQl 

ratnids of three sides, joined at the centre, with 
diverging rays ; their bases forming the surface of 
the circumference, but they are often covered with 
a spherical layer of- the same substance, conAisedly 
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 fans when 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, the inner surface being only crys- 
taHsed in what was formerly called the dogs^tobtb 
spar, but now the metastatic of that diligent crys- 
talographer Haiiy. Under the same form these 
spars line the cavities of the beautiful tufo 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 coverd 
these famous rocks. 

^* This substance is still more frequent in tb% othns. 



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/tnvjtie^ of a bdrd Md oMipacft lava, in the nei^- 
()0Urmg mountitin^ of Trexsa, on tbo hiU of CiMi, 
ini ia tlie BoighbcHirbood of Paterno, dbposed io 
beautiful starry crystala, formed of apkodkf pj- 
ramidal plate3> more or le»s transparent, united m 
tb^ oeatr^ ; diverging QOQietiaiea with aggregtfad 
rayf . pome^njee with distinct, aud of various 
k^gtb; sometifne^ they are fascicular. Bat the 
i:alcareoti9 spar airamea a vast number of foms, 
of H'hieb it is capable. In the heaviest and most 
compact lava^ of tlie rock of M otta, tbe cavities 
concealed in the mass, and which wpre formed 
wbiie the paate waa in a kind of ferment, are lined 
wHh tbe 9ame nub^tance, covered with many mir 
m\e ^obulee> but not visibly ciysta&ed ; tad I 
have ibiind it in the same form in the lava on the 
bi^ summit of the mountam of S. V^naera. 

^^ This calcareous spar may be said to be always 
irhite ; but the iron proceeding from the decom* 
position of lavas^ often tinges it with vmoos co« 
loursy from blood-red to deep brown. I ha^e 
found some at Favarotta^. near the lake of Palici, 
which could not be distinguished, except by the 
chemical test 

'^ At no great distance from the moufttidn of Pa-r 
temo, there is a vast heap of large masses of lava, 
containing crystals of felspar, where there are 
aema cavita^s filled with calcareoua apar in bright 



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fMtf lltmidd of tiMqual lengtb, tmited in fts^ 
^wMi diverging tB,j$; but the cbief Angularity i$, 
tiMt dl Che mase is Inll of petrol, which also fills 
mmxj ef the eanties. Oi^ breakiag this htra the 
cH r«is out, which^ though of a bhtek colour, is 
so mibtile as toapproach naphtha, with a pungent 
fldadl, which it soon loses- in the air. There seems 
no reason to doubt that this petrol has been pro«^ 
cbieed by infiltration *.'' 



NOME Tin. VOLCANIC GLUTENTTE. 

This denomiaatioa inclades, as usuad^ wliat 
are called bricias aod pttddiDg-<stones, bewlg, 
fragments of different rocks joined by lava or 
tolb. The jHperkw of the Italians is a volcanic 
briciai the oe«ient being a grey ptimaeeons 
t^b^ in whicb are concreted fragments of gr»- 
iiite,i £dsite, marble, gypsum, with crystids of 
siderite and mica. In tbe extinct volcano of 
Beaulien^ tbfee leagues to die N* W« of Aix in 
Provence^ Saussnre observed a singular pud- 
ding-stone, composed of fragments of vesicular 

•' Ferrary 171). 



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SQ4f pOMAUt XIU VftfLCAlEXO. 

lava^ mingled with others of a violet cdoor^tid 
bits of white limestone^. Doiomieu deseribei 
Biieias. a siUceous lava, which is a bricia of ^Ucoms^ 
substances and pumice* Ij(i another pi^ssi^ he 
seems to doubt whether Etna eyer had aoy erup- 
tions, of mud, so common in the continental voW 
canos of Italy, and which, according to bim^ 
have formed stones of an argillaceous base caUed 
peperino ; nor are there any bricias called tufo, 
formed in the water by volcanic ejections f. He 
however describes a glutenite 6£ fmgosents of 
compact lava, black clay rock, and spsLihose 
iron ore, cemented by a clay with red and white 
veins. What is called leucite lava is a glutenite 
of those crystals, cemented by tufo or compact 
lava. 

Tufo it&elf may be regarded as a glutenite or 
volcanic sandstone ; but in this instance forms 
so important a feature of volcanic eraption^ 
that it has been considered apart: so that the 
present division must only be understood to com* 
prise what are called large*grained glutenites, 
though in some instances tufo may pass into 
bricia. In his classification of volcanic sob- 
stances Faujas has joined them together; but 
his account shall be transcribed, as it presents 

• § 1529. 

t Ponces, 108, £ui» 354. Biit ooiopare Ferranu 



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HOME. VUI« TALCJJIIC C9CimMIT£« SOS 

some iiwIracttTe remarks and mterestitig singu^ 
larities : and the extreme minuteness of the de* 
8€ri|HaoDS wUt serve fuHy to instnict the reader 
in the natore' of these complex substances, the 
mingled, prodocta of fire and water*. 

« Division 1*, Bricias, whose formation is Caujojpeiij 

rwgas. 

owing to lavas, which in their state of fiuiditif^ 
have embraced other kinds of lavas^ whether com-^ 
pact or porous J scorified^ vitreous, or other ston^ 
substances reduced into fragments. When ihe 
substances thus i^tbedded present kernels more or 
less, angular qf a certain size, and the lava which 
unites them is hard and solid, they may be called 
volcanic bricias^ If , an the contrary, the frag- 
ments are very small, and the paste which sur- 
rounds them is friable, soft, and rather earthy 
than stony, tlse name tufo is more applicable. 

^^ 1. Volcanic bricia, formed of angular and From fiie. 
round fragments of black compact lava^ of black 
lava rather porous, and some grains of white fel- 
spar» strongly united by a very hard granular 
. lavaj of a reddish colour. 

^^ 2. Bricia, formed of angular fragments of 
black lava> hard, with small pores, united in a, 

* This is also from the Annalet du Museum. In the Geologie, 
origtoally delivered » a coune of lectaroj it is much abridged. 



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f0§ wmuaw mn» v«i»omm5* 

fiM paste of niiish Uvm wUdi had a teadncf 
to pMB to the stale of pmmoe. 

*^ 9. Bficia»flunilar in aspeet to the piwedhqf, 
bnt ^ttierent from it m as nraoii m tkf^lmgmmU 
of black lara, instead of being ]ioroii% am io the 
state of semi-yitreoQS drosses, of a very bright 
Mack. The gtey paste which imites this bricia^ 
and gives it a strong consistence, is composeif 
of fine particles, but ralbar scafjr, verjr nearly 
allied to hard pnmice. ^ 

•^ 4. Bricia, ibrmed of anguCar /mgments of 
Mack porous hira, of some smaff grains of white 
fehpar, opake. Mended in a paste of grey pn- 
aiice with small pores. 

^ S. Bricia, with angular fragments of white 
csdeareous stone, grey and sometimes reddish, of 
tbe nature of marble, capable of recemng a po- 
lish, wery where and tn everj diiYctioa enclosed 
in a grey lava, hard, spnnkled with ftagnients 
and crystals of whHe felspar, diaphaaoas and 
shattered, of Mack hornblende, with some grains 
of pjrroxene of a grass green, and wrA some 
spaugles of silvery mica : this last fs iband In it 
in a yery small quantity. This bricia is bard 
jEfnough to be sawed nnd pofished : H strongly 
attracts tbe magnet* 

'' .& Brioia,, Vbtb large fragniaala d white 



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WOMB Vlll. r^LCAmO OftUTftNITB. ff^ 

iiMiTble» of yeUowiBh marble with s fine sftlioe 
grainy which takes the poHrii ; of grey stone of 
a vtrjr fine pasted which cannot be scratched by 
sisd, bat wfaieh nevertheless effenresces briskly 
with nikroDB acid : it seems to be silieeo-calca* 
recMs. The differeot fragments of these stones 
are imbedded in a grey iava, rather earthy, but 
solidy mixed with many black pyroxenecf, divided 
into very small fragments. 

*^ 7. Bricia, with fragments of white and gr^ 
nmible> and some kereds formed of a mixtore 
of clear felspar, and a black An bstance which has 
some resemblance to hornblende. Conglome- 
rated nodules of black mica are also fbnnd in it 
The several foreign bodies are imbedded in a 
grey lava, which contains in great abundance 
small fragments of p3nroxene5 of a brilliant black 
in appearance, but which, observed with a lens 
in a strong light, are found to be green : some 
strongly marked crystals of that substance are 
even distingubhed, which are diaphanous and 
^ a grass green, and some spangles of silvery 
mica. 

'< 8. Bricia, with large nodules of volcanic 
chrysdiite, of a greenish and yellowish coloor, 
mixed with large fragments of porous lava, and 
of faiack compact lava almost scorified, cemented 



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5()|g OeiCAIN XII. TOLCAMIC. 

by a grey lava, which itself contains a nnniber 
of sandy grains of black lava* 

'* 9. Bricia of a yellowish base^ with verj 
large fragments of a black compact basaltic 
lava, iiUed with vitreons grains of chiysqfite t^m 
yellowish green, and a number of smafler ftag* 
jnduts of black lava with small pores, 9ome of 
"which are vitrified. The yellowish and rather 
earthy lava, which cements this bricia, contains 
some grains of black pyroxene, which seem to 
have been melted ; and of flaky felspar, changed 
and of a dirty white. 

" Division 2. BriciaSy or volcanic tufott/orm^ 
ed by the concurrence of fire and water, carried 
to the highest degree of temperature : the rooter 
introducing itself by some subterranean communis 
cations into the burning centre ofvolcanos, haspro' 
duced results and particular combinations^ which 
partake of the contrary properties of those two 
elements. 
i^om^ « ]^ 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 red, irregalar 
pieces of hard grey marl, reddish in many parts, 



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NOMS VIII. TOLCAVIC ^LVTINITI. <50B 

and of sQOie geods with a crast of brown hema^ 
tite, which seem to be the result of the iofiltra- 
tiocHB of a marl, which is found in pieces in this 
bricia, and which is strongly impregnated with 
iron. 

** 2. Bricia, formed of. fragments of brown 
porph/ry^ and of porph/rjf with a red base^ with 
paxallelopiped crystals of white fdspar, frag- 
ments oi white marble^ surrounded in their points 
of contact with black lineaments, which seem 
to be the resuH 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 black melted pyroxene, is so amalgamated, by 
the assistance of calcareous infiltrations, with 
the other parts of the bricia, that the whc^e 
forms a subsUnce capable of being polished. ' 

Division 3. BriciaSy or volcanic tufoSj formed 
by Sections of substances reduced to pieces^ to 
grains^ or to powdery sometimes carried to a dis'^ 
tance by explosicjis and by the winds^ afterwards 
uniting, whether they fall into the ssa, or are de^ 
posited in places where the rain water consolidates 
them, as at Pompeia, and elsfewhere. 

** 1. Volcanic tufo, which owes its origin to From water. 
slioMT^rs of black and grey pumice, divided into 



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01^ obiuiv fau roLCAVfc. 

ftmgaytwta the aze of an oKve, and ooMrtUBes of 
a nut, adhering by the poinii of contact the 
matter which nnikes them not being distil^^aish- 
able. This tofo is exceeding light, bnt not of a 
strong consistence. 

** 8. Tufo, wiiose base is a pumice ledaced 
into so fine a powder that it has the appeanuce 
of an argillaceous substance : this unites a imm* 
ber of veiy small grains of pumice, dryer, harsher 
to the feel, and much less altered, and very dis- 
tinct pieces of porous lara, although parti/ dn* 
eoloored. This tufo forms one of tlie vmeuei 
of tnos ^ Pleyt, in the emiiuos of Andemadi. 
What I hare said of it in a distinct UMnoir may 
be consolted, in whidi I have described the 8e« 
veral considerable quarries^ of these tarrsfisesy 
which are wrought to be converted into ceuient 
See Aimales dx Mu$eumy vol. i. p. 15. 

" 3. Tufo, formed of a mixture of pamice in 
powder or in grains, angular fragments of Mack 
compact basaltic lava, and small scaly fragments 
of a grey schistus, rather shining, not volcanic, 
which has been cast up with the other sab- 
stances; It is in this variety of tufo, which has 
much more solidity than the preceding, and 
which has formed beds and masses more than 
fifty feet thick, that there are sooietimes found 
cylindrical pieces of real charcoal^ as soimd and 



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MOMB TIU. TOLCAXIC OUnSHtTE. AH 

veB ptCMrmd w if thejr hMilatdj been pre* 
pand. Sae wtet I have 0aul of this carioiifl 
ymmtf of trass of the enrirooB of Anderatcky 
¥oL i. p. S4, of the Anmiles du Museum. SpaU 
laoBani fenad a similar charcoal in a tufo of the 
iileofLipari* Sea also fd. iii. p. 11^ of Spal- 
hmjanrg Fayage to Sicily . 

'* Of the particular configuration peculiar to 
some ti{fos. 

^ JVote>~Ifcarast be obeerwd, that nnder some 
ftwowMtances tafef» partionlarij those vrfiioh 
oare their or^a to the concmrrenoe of fire and 
water^ have undergone a recession which ha^ 
given them a prismatic form. I have seen simi- ^l£^ 
hroaeaj b«t in small qaantitiefl^ in the extinct 
volcanos of Habischwald, near Hesse CasseK 
The most remarkable of this kind are these of 
Campanis^ near the town of St. Agatiuh also 
between Mounts Sarchia and Viiolan^, near a 
place caUed La VarretteUa: but the largest and 
the best formed are those which are f(wnd on the 
road to Venafro^ near the bridge of Calvi and 
tlM tavern of TorriceUa. 

^ Chalcedonic substances are sometimes found ciaUcecioty, 
in tnfos, which seem to be the result of a second- 
ary formatioiiy anch a^ those <rf Fomt^dn^Ckattau^ 



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m OOMAni XIX. VOLCAMiC. 

and of some otha* parts of Anvergne, where fine 
lentils of chalcedony, and chalced<»ic ciyslal- 
lised quartz, are found* The perlstein ofSattcla 
Flora, on the confines of Tuscan jr, is an aoalo* 
gons 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* MuUer observed this substance formed 
in 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 seme substances of the organised kingdonij 
which are accidentally found in tufos. 
^»«»j^^ «c 1^ The fossil tusks of the elephant have 
been found in tufo in the neighbourhood of 
Kome. 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 MuDer md l» him, 
'* I have infinite obligationt to naiwal history, U dunm ny lut 
moments, and the weight qf ninety-Jive years, my present age, does 
not weaken its power. One has always fresh enjoyments, one Bves 
without rqnva^h, and ono does not die, buifaUi mloop .^ 



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VOUB Till. VOLCANIC GLUTINITS. SlS. 

sent k 10 M. Baffbn : 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 in 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 Lacepede, who inserted it in the 
Journal de Physique^ vol. 54, page 444. 

'* 3* In digging some years since, in a tufo of 
Moot 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. Difierent kinds of shells are found, as Sheib. 
well univalve as bivalve, in some tufos j and these 
shells are scarcely altered. 

" The valley of Ronca, so well described by 
Fortis, and which he justly calls volcanico-ma^ 
rine, 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 different places of Vesuvius. Some con- 

VOL. II. 2 L 



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t]4 »OIUilt XtU VdMAMtC 

tain marine rabstances^ and he has one in vhich 
18 distinguithed a madrepore, common in the sea 
of Naples ; it is the retepora spongites of LiimeiUj 
the poms anguinus ci Imperati* 

<^ In the mi^ificent gardens of the Elector 
of Hesse Cassel, at Waissenstein, in the nudttof 
a volcanic soil, is found a sandy tnfo> filled with 
beautifttl shells of different kinds ; among which 
I observed the Venus islandica of Lamarcki and 
the area pilosa of Linneus. 

^' I possess in my collection, a shell of tbege- 
nns cone, in a very hard volcanic tufo, which 
has filled its interior, found on the sea shore at 
St. Croix, in Teneriffe; jt was given to me by 
M. Bailly, onQ of the mineralogists in the ex* 
pedition of Capt* Baudin. 
Ugoite. << 5. 1 have already mentioned wood changed 

to coal, which is" found at a great depth in the 
tufo, of the environs of Andemach, and in that 
of Lipara. 
. pianta. *• 6. I ought ttot to pass in silence, the tnfo 

of Rochesauve, in Vivarais, of which the beds 
seem to alternate with other fbssile beds of a 
light marl, which contains leaves of trees and 
plants^ whose fibres are in the most beautifnl 
presermtion, but whose parenchyme is black 
and carbonised. I have a numerous collection 
of those plants, which I gathered on the spot: I 



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MOMB IX, fPIMTAllflSS SIBOTSD OR CBANOBD. JU 

JAtend ihofdy Co make them public^ by hsmg 
tlieiii engraved, and to give the explanatioas of 
those which have reiatiotu with known species.^ 

arpOKOftfB I. VOLCANIC BaiCIA» 

The various kinds are already mentioned. 

Micronome 1. Peperino. 

From the environs of Vesuvius, &c,* 

Microrumie 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 td 
firaon, but in many instances, exploded by the 
vapours, without being visibly affected by heat. 
Whole masses of rock, nay mountains, are also 
fiMibd changed by the action of the subterranean 
vapours, as the celebrated Puy-de-Dome, which, Pmy-dt-Dame^ 
according to Saussure § 728, 729, is a porphyry 
with a base of earthy felspar; and be found one 
of the same kind in the Valorsine. Mont Dor 

* Monit Nmotfo near Naples, considto of tndunled powder^ p«i» 
Kiioe* *ad fra(;iaeQti of Itva intcrmingjed* Comuag a pepenoo* 

2l2 



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Ptraatic 



SlQ. fiDMAiv XXL rmMonci 

also piMentfl.graiiitty evidently afiectod by iMt, 
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 vapoorst* 

HYPONOMB I. UMB8T0NX. 

%is substance deserves the first place, as that 
ejected by Vesuvius is not only more fiequent i& 
cabinets than any other exploded rock, but con- 
tains several remarkable parasitic stones; such as 
1. The Fesuvian 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 would seem that the latter is, how- 
ever, the same with the olivine of Werner, also 
called volcanic chrysolite X. 2. The sommite of 

* It is surprUing that the French writers oontinne to ipeU ^ Or u 
if it were the golden mountain, while Le Grand (Voytse dAu- 
fctgne ii. 66.) has demonstrated, that the name was taken fiom ^ 
river Dor, which, with the Dogne, forms the Doydogne. 

t The lava decomposes into clay, or rather the aigil displays it- 
atlf $ whence the environs of volcanos are very fertile. 

} Because the olivine is found in hasalt, the Wenevians reject 
it from the volcanic substances, while it is in fact the commoa vol- 
canic chrysolite, as Breblak has shewn. Gioeni^ p. 217> obsem^ 
that many scoriae of Vesuvius and Etna contain a ydlowish subttanc? 
like glass, pprfectly nsembltng that in the native iron of Sibds. 



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Kccrstinfi, the nephi&ne oi Haiiy, of a whilte. or 
greentth grey, found in the ejected rocks of Monnt 
Sonuna, which may be styled the parent of Vesu- 
vius. Leucite is also found in the calcareous rocks 
of Somma, accorc&ig to Breislak : but the pyroxene 
of Haiiy, the at^te 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 Sonuna. 
Kirwan has strangely confounded the volcanic 
jacint, or vesuvian of Werner, with leucite or white 
garnet* 

Limestone with sommite, from Mcmte Somma. 

HVFONOlfB II. 6RANITB. 

In tills 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, oh the 
confines of Tuscany and the Papal territories. If 

• la the laogmge of jewdkn stumed, corrtiponduig with the 
French e<0fui/. 



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sift VDMAIW Ktl* TOMMWb 

the ejected granite contains garnets, they arecoiD- 
iDonly vitrified 

Saussure obs^red^ § 730, tbe effects (tf vitri- 
fication on granites in the lime-kilns of CfauDouni. 
Those that have suffered the least heat^ arekoonTi 
by the dull white appearance, and cracks pf ths 
quarts and febpar, and by the glossy golden 
lustre of the mica. In a greatar deg^ of heat, 
the mica and felspar appear melted, but without 
derangement In the greatest heat, the mica is 
melted into large round bubbles, while tbe felspar 
looks like ^a$s with microscopic bubUes; and 
the quartz is only of a . dull white, without any 
af^iearanceof fusion. 

HTPONOMB III. MIGA-SLATB. 

This sometimes accompanies ejected grambos. 

HTFONOMB IV. 8LATK. 

This substance is chiefly conspicuous among 
the ejections of Hecla. 

BVFONOMX T* BA8ALT0N. 
HYrOKOlfB VI. PORPHTRT. 

These two kindred rocks are frequent in vol- 
eanic oountriea ; and abound among the <gecticms 
of New Spain, and other volcanic regioos. 



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NOME IX. msMrjoms bjxctbo oa chanobo* 519 

HYPONOMB VII. SAMIMTONS. 

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 would be among the most 
common. 



This arraaganeiit of vcrfcaaic substaocea beiog^ 
from its nature, rath^ jejune, it may be proper 
Bomewfaat to diversify it by a few general remarksi 
and some examples of singular volcanoes, chiefly 
from Patrin and other foreign authors, whose 
works have not been translated. It migtit have 
been tfaou|^ unpardonable to have passed, with 
irreverent brevity, some of the grandest features 
of notune ; especially as the recent progress of 
mineralogy has thrown new li^t on many topics ; 
and the ignorance of the ancient accounts has 
been dispelled 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 ; otherwise 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 owi 



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5S0 »OaiAX» XIL TMOAHie. 

abysses. He introduces thb new system by tbe 
theory of thi^ great astanoMpier and geometricbn 
Laplaoey that this earth, and the other planetary 
bodieSy have been formed by the concretion of an 
aeriformjluidj which emanated/ram the mm. The 
account, given by Dolomieu, of the singular per- 
petual volcano of Stromboli, furnishes our inge- 
nious author with his chief arguments in fiivour of 
this hypothesis. 
stfomboB. ^^ The volcano of Stromboli is one of the most 
curious and important in the illustration of vol- 
canic phenomena. It is in one of tbe isles o{ 
Eolusy on the north of Sicily; and Dolomieu's 
description is very interesting. This volcano was 
already noted in thedays of Pliny ; and its erup- 
ticms, from time immemwialy arise every dg^t 
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 m 
the north-west 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 quantity fell back into the 
crater; while others rolled even to the sea. Each 



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^13 



BOMAItr XII, VOLCAMIC* SH 

eKploskm was accompanied wiHi a burst of red 
famfe • • . . The stones ejected are of a lively 
red, and sparkle, having the eflfect of artificial 
fireworks/ 

" I must here remark that these sparkling 
masses with the effect of fireworks, announce that 
their base is comBustible. 

** Having visited the mountain cm the following 
day, Dolomieu thus continues his description. 

^ From a littie summit, you have a view of the 
H^amed 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 eruptioti. They 
are thus tossed till tiiey are broken and reduced to 
cinders (coarse powder). But the volcano always 
affords a new supply ; and is inea^haustibk 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 



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SSUi. oowam XII. TOvtMiP^' 

8ir. There are times when the eraptions are more 
precipitate and violent : and the stones, describiiig 
more divergent rays, are thrown into tlie sea at a 
' considerable distance. In general the inftunma- 
tion is more considerable in the winter tiian m the 
summer ; and more on the approach, and dming 
the rage, of storn^s, than in calm weather/* 

'' The author afterwards adds, that ^ Stromboli 
is the only known volcano which has such fiequeot 
eruptions. The fermentation of the others in- 
creases progressively, but here the erupticHi is coo* 
i^tant .... and it would seem that it aiisea from 
air or inflammable vapours, which suddenly tbdie 
and explode, expelling the stones which impede 
the vent"t 

Patrin proceeds to argue, on his system, 1. 
That the eruptions of Stromboli arise from a cause 
always reproduced, otherwise it would have beoi 
exhausted. 2. That the stony masses are instsn* 
taneously formed, by the contact of the air; as 
lAagic alone could always supply a like numbcar d 
stones, and still preserve the precise form of the 
crater. 3. That the focus is of litde dq>th, as 
there are no commotions nor subterranean noisesi 
and the stones diverge; for a cannon scatters 
grape-shot in proportion to its shortness. 4. That 

• Lipftii, U9. t F^trin, Mia. v. »g« 



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BOMAfv ani. ^otokwoi |fgf 

the electric fluid is a principal agent la volcano^^ 
because the eruptions are more frequent and vio- 
lent in winter, and in stormy weather. He am* 
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 violent 
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 ideor 
rivals Stromboli in singularity, a gerbe or sheaf 
arising, like what is called a jChinese tree in arti- 
ficial fireworks, and resembling tumuHuoiis waves 
of fire, darted to the height of more than a hun- 
dred and twenty feet, and dashing against each 
otiier with a sanguine light, visible even at noon- 
day. The summit presents glassy drosses ; 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 giveo 
the following account of these phenomena. 

• BoTf » Vfiy. 1S04, 3 vob. %vo. ii. SSI. 



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5S4 m>aui» xiu vobOAvte. 

itan. ^* Th6 island ol Therm, afterwards St hm, 
and now Santorin, was sumamed by the GhMWH 
KafUHif that is to say, burnt : and so in fiict the 
SOU is. * There is a traditbn/ says Pliny, B>. S. 
cap. 87, * that it rose out of the sea, at a very re- 
.mote but unknown period/ This tradition is rea- 
dered probable, by the known events, which have 
since taken place near it. 

^' This island with that of Mik>, of which we 
have spoken, and that of Paros, so famous for its 
marble, foims a triangle, the sides of which are 
about fifteen leagues each. I suspect that there 
is a considerable central fire amoi^ them, of which 
the volcano of Milo might have formedy 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 afiected in the great conmiotions of Saotoria. 
I found my suspicion of this central fire on a vast 
Bant idol, number ofsmaii burnt islands^ as they are caOed 
on the chart of that sea, which are scattered in the 
midst of the three principal islands, and of which 
several had not appeared till within the eigjitaenth 
century. Almost all of them are near Milo, where 
there is less depth of water. I should ima^ 
that these small islands are simply the productions 
of the central fire* The sea, on the contrary, k 



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r&ry. deep towards. Santorin, where it coTers the 
mountain, whenee proceed inceasant eniptiona. 
Tliere is no ground for anchoring near it» as is 
mentioned by M. de Bomare, vol. xv, page 1S8 
of his Dictionary. 

*^ Whatever on the surface of this sea-covered 
mountain be the quantity of matter which has 
bsued from it, when the fires once set in motion 
in the void at its base within become active, they 
rise violendy 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, are always 
the p<Hnts most strongly attacked ; there it must 
and does in fact give way, as is the case with a 
vic^cano on land opening for the first time. And 
when eruptions take place in a submarine volcano, 
the maases already settied are always affected I^ 
them, and partiy open, and their surfaces either 
^n by the addition and adhesion of new ejections, 
or lose by some of their parts smking 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 Fatiier Gor^e^ who was an eye- 
witness of it ; and of his narrative I will give an 



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58fi aOMAIV XII. TOftCAMIC 

ibfttract, after I have taken notice of lite ci^ 
known eruptioiu which were prior to it 

^' They are all interesting to a laudable curiosi- 
ty, and proper to throw light on this operatioo of 
nature; but as the circumstances of this grand 
phenomenon are nearly always alike, I shall do 
little more than date the former eruptions, rea^v^- 
ing for the account of the last tiie most reaMuic<* 
able particulars which generally attended the 
eruptions, 
oteft. « In the fourth year of the ISith Olympiad, 
that is to say, in the year 236 before Christ the 
island 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 been 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 tb^ 
island, called Thia, at two stadia, or two hundred 
and fifty paces, from Hiera. 

^' These three eruptions are recorded by Pliny, 
in the place before cited ; by Strabo, lib. I ; and 
by Seneca, in his Naturales QuaesUones, lib. 6, 
cap. SI. 



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^ lo the year 7i6^ the yrieano, t&er lodeiA 
c^ectioos of ashes and red-hot rocks, disgorged a 
gmeat qua&tity of lava, vhicb joined Thia to 
Hiera. 

*^ In 1457| this island was still £uther in- 
creasedy attended by the same circumstances. 
This events and the date of it, are attested by an 
inscription on a marble stone erected near the gate 
i)i Fort Scams, in Santorin.* 

^^ A sixth eruption, in 1570, produced a new 
ialand : it is calted the little Kamenoi. 

^' In 1650, the agitations of the volcano lasted 
almost a twdvemcoith. Its greatest convulsions 
wefe at the beginning, from its opening on the 
84th of September to the 9th of October. The 
sea rose to the heij^t of forty-five feet, and that to 
aach a distance, that s<Hne galleys of the Grand 
Seignor*s were wrecked in the port of Candia, 
though it is mcMre than eighty miles from Santorin« 
Smyrna and Constantinople were incommoded 
with the ashes which rushed out of the sea in 
wfaMwiDds of flange. All the particulars of this 
erupticm are to be found in Kircher, a contempo- 
rary author, after the account of the preceding. 

'^ This inexhaustible volcano again opened in ^P^ 
1707. The Little Kamenoi was increased, and is 
sow more than three leagues in circumference. 

^* Most of these eruptions, and all the circmn- 



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-Sf^H POMAM XII. T01.CAK16. 

Manoes atteDding the last maitkmed, are repotted 
ID the third volume of the Memoirs of die Aca- 
demy of inscriptioiis, and in those of the Academy 
of Sciences^ of the year I7O8.* 
Of i76r. <^ The eruption of 1767 took place between tiie 
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 to oc« 
casion a dread of its swallowing up all the islands 
thereabout. A thick black smc^e darkened the 
air, and infected it with so strmg a stench of sul- 
phur, that many persons and aiumals were siiffb^ 
oated by it Black ashes, resembling gunpowder; 
fell all round. Torrents of flame, issuing from 
the sea, and waving on it to the height 6f several 
feet, lifted at intervals tiiis hcMrriUe scene. The 
fri^tful mixture of diflferent sounds, produced by 
all tiiie elements in fury, froK every heart wttb a 
dread of the horrors which every instant m%ht be 
the result of their conflict 

^^ At length, after a labour often or twelve days. 
Nature paused, and the effect of her agiti^on was 
discovered in a new island, which had rken near 
the Little KamenoL There was no time lost in 



* An aUttict of these remarkable pheaomeoa diaD pcceen% be 
given.— P. ^ 



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xM>iiAiir III. toteAwte^ 539 

^faig to examine it Many parts of it Were 9t^ 
burning. It was a dhapeless mass of baked siib- 
stancesy amalgamated by a lava, which^ Father 
Gor6e says, appeared to the eye like the crumb ctf 
fine bread. Bat 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 
theif! formidable appearance. The syniptoms ap^ 
peared even to spread wider and to tiireat^ worse. 
The boiling sea several times changed colours 
flames, following one another without intermissioii^ 
issued as from a vast furnace, but accompanied 
with ashes and pumice. Thefrightfol- ncise of 
subterranean thunders was heard. It seemed as 
if enormous rocks, darting from the bottoms of the 
abys6| beat against the vaults above it, and were 
akemately repelled and thrown up again ? the re^ 
petition of their blows was distinctly heard. Some 
of them, making or finding a passage, were seen 
flyii^ up red-hot into the air, and again falling 
into the sea whence they had just been ejected. 
Masses were produced, held together Ah* .some 
days, and then disappeated^ In tUb gemeni dk^ 
or^r large portions of tiie Littie Kamenoi were 
swallowed up. Afoanwhile the labour of the vol- 
cano took a larger surface, its ejections became 

VOL. II. S M 



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^50 DOUAIM %iU YOteAHlC* 

prodigiously abundanty axid a new inland was seeti 
finnning. By aueopssive additioiis^ ontioued foe 
near four months, it .made a juoetioi} with tfask 
produced in June.' It was named the Black 
Island, from the colour of its soiL It is nearly 
twice as large as th« Little Kamenoi, and is sepa^ 
rated from it by a very narrow strait The vol* 
caoo continued cr^tii^ alarm till the end of May 
in tlm following year; irequentiy shakikigtheeardi 
and 600, and causing frightful noiseii. It even 
opmed again, but cmly.for a moment, on the 15th 
of A{ml> and threw out a multitude of laige burn* 
ing rocks, which fell at the distance of two mtleap 

^' It is therefore proved by nine eruf^ns re- 
corded in history, that thene eiusls a maritisM 
volcano at. Santorip* These eruptions ha;ve hap* 
pcned in the space of twenty-one cei^uries."* 

But of the noted eruptions, (tf 1707, a more mi* 
mte and isatifii&iCtory account had before appeared 
m another work. 
SraptiooB of ^^ Acrotcri is an island frunous in natural his* 
tory, and is situated in latitude 36^ ncHth, loBg^ 
tudeS6^east; itseernKtobetccmq^sedof pumiofr^ 
stoni^ encrusted with a sur&ce of fertile earth, 
and the ancients represent it as risinj^ in a viident 
earthquake, omt of the sea. Four othor islaoda 



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OOHAtH XIU TOIiCAffIC* 531 

bad ibe same origm, and yet the sea is here of 
soch a depth as to be unfathomable by any sound*- 
iDg-lhie. These arose at dUTerent times ; the first 
long before the commencement of the Christian 
asTB, another in the first century, a third in the 
e^thy and a fourth in 157S. Another island 
arose in the year 1707 and 1708, between this 
island and Chreat Cammem. The reader will not 
be dtsfdeased at seeing here a particular account 
of this extraordinary phenomenon. 

'' On the 23d of May 1707, after an earth- 
quake that happened the night before, the last 
mentioned island was discovered early in the mom* 
\a% by some seamen, who, taking it for a wrecl^ 
rowed immediately toward it ; but finding rocks 
and earth instead of the remains of a ship, hasted 
back, and spread the news of what they had seen 
b Santorini. How great soever the apprehen* 
sioos of the inhabitants were at the first sight, 
ttieir surprise soon abated; and in a few days, 
seeing no appearance of fire or smoke, some of 
them ventured to land on the new island. Their 
curiosity led them firom rock to rock, where they 
found a kind of white stone that cut like breads 
which it nearly resembled in its form, colour, and 
consistence. They also found many oysters stick- 
ing to the rocks ; but while they were employed 
in gathering them, the island moved and shook 

S h8 




Google 



553 BOSIAIN XIU TOUSAlriO. 

under tbrir fiset, upon which they ran with pred-^ 
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 
. fixHn the island, which, having continued £3ur 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 waa 
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 l6th of July the smoke first appeared^ 
not indeed firom the island, but firom a ridge of 
black stones which suddenly rose about sixty paces 
firom it, where the depth of the sea was nn&thom^ 
able. Thus there were two separate islands, one 
called the fFhitCj and the other the Black Island^ 
firom their different appearances. This thick 
smoke was of a whitbh 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 Idth and SOtii of 



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OOMAZN X|I. TOLCANIC. 53'3 

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 fast; large rocks 
daily springing up, which sometimes added to its 
length, aiMl 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; 
and the sea was then covered with a scurf 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 istreets 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 Santprini, 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 31st of July, the sea smoked and bub- 
bled in two difierent places near the island, where 
the water formed a perfect circle, and looked like 
oil when ready to boil. This continued above a 
month^ during which many fish were fouqd dead 



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534 DOMAHf XII. YOLCAMXC. 

on the shore of Santorini. The following ni^t a 
dull hollow noise was heard, like the distant re- 
port of several cannon, which was instantly fed- 
lowed by flames of fire shooting up to a great 
height in the air, where they suddenly disappearecL 
The next day, the same hollow sound was several 
times heard, and succeeded by a blackish smoke, 
which, notwithstanding a fresh gale blew at that 
time, rose up in the form of a column to a prodi- 
gious height, and would probably in the night have 
appeared as if on fire. 

" On the 7th of August the noise was difierent; 
it resembled that of large stones thrown all lea- 
ther into a deep well. This noise having lasted 
some days, was succeeded by another mudi louder, 
so nearly resembling thunder as hardly to be db- 
tinguished from three or four real clc^ that hap- 
pened at the same time. 

" On the 21st, the fire and smoke very consi- 
derably diminished; but the next morning they 
broke out with greater ftiry 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 manner. At night, 
our author viewing with a telescope a large fur- 
nace upon the highest part of the island, disco- 
vered sixty smaller openings or frumels, all emit- 
ting a very bright flame ; and be imagined there 



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Doukim XII. ToLCANio* 535 

might be as many more on the other side of the 
great volcano* On the S3d of August, in the 
momingy the island was much higher tha^ the day 
before, and its breadth was increased by a chain 
of rocks sprung up in the night a^ost &fty feet 
above the water. The sea was also again covered 
^ith reddish froth, which always aj^peared when 
the island received any considerable additions, and 
occasioned an intolerable stench, till it was dis* 
persed by the wind and the motion of the waves. 

^' On the 5th of September, the fire opened an* 
other vent at the extremity of the Biack Island^ 
from which it issued for several days, during 
which but little was discharged from the large fur* 
nace : and from this new passage the astonished 
spectators bdield the fire dart up three several 
times to a vast height, resembling so many prodi* 
gious sky-rockets of a glowing lively red. The 
following night the subterraneous fire made a ter- 
rible noise, and immediately after a thousand 
sheaves of fire blew up into the air, where, break- 
ing and dispersing, they fell like a shower of stars 
upon the island, which appeared all in a blaze, 
presenting to the amazed spectators at once a 
most dr^ful and beautiful illumination. To 
these natural fireworks succeeded a kind of meteor, ^ 

which for some time hung over the castle of Scaro, 
which is seated on a high rock in the island of 



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5S6 2K>1IAXII XII. TOLeAHlO. 

Slintorini, a meteor not unlike a fiery sword, and 
which served to increase the consternation of the 
inhabitants. 

'' On the 9th of September, the fVhite and 
Biack Islands united, after which the western end 
of the island daily increased. There were now. 
only four openings that emitted flames, which 
issued forth with great impetuosity, som^unes at* 
. tended with noise like that of a large organ-jHpe^ 
and sometimes like the howling of wild-beasts. On 
the 12th, the subterraneous noise became much 
augmented, having never been so frequent or so 
dreadful as on that and the following day. Thd 
bursts of this subterranean thunder, lU^e a general 
discharge of the artillery of an army, were re* 
peated ten ' or twelve times within twenty-four 
hours ; and immediately after each clap, the lar^ 
furnace threw up huge red-hot stones, which fell 
into the sea at a great distance. These claps 
were always followed by a thick smoke, which 
spread clouds of ashes over the sea, and titie 
neighbouring islands. 

^^ On the 18th of September, an eur^uake 
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. Tlie claps were also more terrible than 
9ver, and in the midst of a thick smoke that aph 



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OOIIAIM XU. VOI.eAliIO. 537 

peared like a mountain, were seen 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 several 
times covered with these fiery stones, which, being 
thinly crusted over with sulphur, gave a.bri^t 
light, and continued burning till that was con^ 
3umed. 

^' On the Slst, after a dreadful clap of subter- 
raneous 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 rocks 
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 afiter. 
But on the 25th, the fire broke out again with 
still greater fury, and among the claps was one so 
terrible, that the churches of Santorini were soon 
filled with crowds of people, expecting every mo- 
-nient 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, 1708, the 



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538 



DOMAIN XII. ▼OtCAKlC. 

large furnace, without one day's intennisMOiiy 
threw out stones and flames at least ooce or twioe^ 
but generally five or six times, a day. 

" On the 10th of February, in the morning, a 
pnetty strong earthquake was felt at Santorini, 
which the inhabitants considered as a prelude to 
greater commotions in the burning island; nor 
were they deceived; for soon after the fire and 
smoke issued in prodigious quantities, the claps 
like thunder were redoubled, and nothing appear- 
ed but objects of horror and confusion; rocks of 
an amazing size were raised up to a great height 
above the water, and the sea raged and bcnled to 
such a degree that it occasioned great consterna- 
tion. The subterraneous bellowings were heard 
without intermission, and sometimes in less than a 
quarter of an hour there were six or seven erup- 
tions firom the large furnace. The noise of the 
repeated claps, the quantity of huge stones that 
flew about on every side, the houses tottering to 
their 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. 

*^ The 15th of April was rendered remarkable 
by the number and violence of the bellowings and 
eruptions ; by one of which near a hundred lai^ 



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DOMAIN XII. VOtCAiriO. 539 

Stones were thrown up all together into the air, 
and fell again into the sea at about two miles 
distance. From this time to the 23d of May, 
which 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 lithof July, 1709, our author, ac- 
companied by the Romish Bishop of Santorini, 
and some other ecclesiastics, hired a boat to take 
a near view of the island. They made directly 
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 they 
directed their course toward a part of the island at 
the farthest distance from the large furnace. The 
fires, which still continued to bum, and the boil- » 
ing of the sea, obliged them to take a great com* 
pass, and yet they felt the air about them very 
hot and sultry. Having encompassed the island, 
and surveyed it carefully from an adjacent one, 
they judged it to be two hundred feet above the 
sea, about a mile broad, and five miles in circum* 
ference ; but not being thoroughly satisfied, they 
resolved to attempt to land, and accordingly 



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540 DOMAIN XII. VOLCAKIC. 

rowed toward that part of the island where they 
perceived neither fire nor smoke ; but when tbey 
got within a hundred yards of it, the great furnace 
discharged itself with its usual fury, and the wind 
blew upon them a thick smoke and a shower o£ 
ashes, which obliged them to quit their design. 
Having retired a little, they let down a plummet, 
with a line ninety-five fathoms long, but it was' 
too short to reach the bottomr On their return 
to Santorini, they observed that the heat of the 
water had melted most of the pitch from their 
boat, which was therefore grown very leaky. 

** From this time imtil the 15th of August^ 
when our author left Santorini, the fire, smoke, 
and 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- 
creased, but that the fire and subterraneous noises 
were much abated; and as the travellers who 
have since 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 unquestionably true ; and indeed, thia 
is not the only instance, in modem times, of 
islands risen from the bottom of the sea; we have 
an account of one such in the PhiloscphiaU 
Transactions^ ml v. page 197, near the Azores, 



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thus taised by subterraneous fires. In the yeaf 
1720. 

" This happened in the beginning of Decembef, 
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 varioud 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, of 
foreign to our common notions of things, than to 
see 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 



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543 i>oiiAiv XII. iroLCAVic 

pent io a narrow passage, are able to raise up u 
mass of earth as large as an island ; but that this 
should be done in so regular and exact a manner, 
that the water of the sea should not be able ta 
penetrate and extinguish these fires; and after 
having been extinguished, that the mass of eartb 
slu)uld not fall down, or sink i^^ with its own 
weight, but still remain in a manner suspended 
over the great arch below ! This b what to me 
seems more surprising than any thidg that has 
been related of Mount Etna, Vesuvius, or any 
other volcano/* 
l7tnnber of Ordinaire estimates the number of volcanoes on 
this globe, in actual activity, at one hundred aad 
eighty-nine ; of which ninety-nine are on conti- 
nents, and ninety in islands. But if we reflect on 
the vast portions of the earth which are still un- 
explored, particularly the interior of Afiraca, and 
of Notasia, it will not be thou^t rash, if the whole 
be estimated at two hundred and fifty ; though in 
strict argument this niunber should be dimimshed, 
and not enlargeijl. 
Etttnct Nor will the candid inquirer reject the suppo- 
sition of a vast number of volcanoes now extinct. 
Vesuvius itself has repeatedly been in this sitaa- 

• Pajrne't Gtogr. Eaclncti, p. 95S. 



^olcaiioes. 



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ooiMkw XII. vojbCAma 549 

tion, as not only appears fcom the testiinooy of 
Strabo before adduced, but from others. For 
Diodonis Skulus^ who flourisl;ied at the be^nning 
of the rei^ of Tiberius, says Vesuvius emitted 
fire in the time of Hercules ; and he adds, that io 
fact it retained many vestiges of conflagration*. 
Vitruvius had before asserted that the eruptions of 
Vesuvius were mentioned in history, and that 
pumice, there found, 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 parts 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 crater, 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.v. 21. fLib. ii. 6. 

t Acad. Nap. apud Ord. 937.' 



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544 DOMAIW XII. TOLCASie. ' 

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. 



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APPENDAGE TO THE VOLCANJC. 
FUMAVOLS, 

OR 

PSEUDO-VOLCANOES. 



▼01. ir. £ N 



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«47 



Products of 
FoMnroit. ^ 



FUMAVOLS. 



XHESE trifling igQitioiis of coal-pits are treat* 
ed by the Wernerians with an importance truly 
ludicrous. Their chief products seem to be in* 
dorated clay» and^ according to seme^ tripolt. 
Slates may also be turned to slags; and what is 
called porcelain jasper, pifobably an iron stone 
affiaeted by the heat, also appears in the yicinity 
of ^hose ignited spots, particularly near Dysert OyNrt 
in Fifeshire, where a coal-mine has continued in 
a state of deflagration^ at least since the time of 
Buchaoao, 156Q; for he minutely describes the 
$pot in one of his poems. Nay, according to 
Mr. Kirwan, who quotes the Memoirs of the 
Academy of Scienees fbr IWlt the mountain of 
Cransac has continued burning nnce the year 
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 



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54S APPBVDAOB TO TVS VOLCAVK. 

long to monntains whicb» like that of Chioiere^ 
DOW called Goranto in Natolia, emit flame and 
smoke, without any other ejection; than to lit- 
tle ignited spots, which^ like one of the Italian 
bles, might be called volcanellos. But a more 
Nine, proper name for these ignited hills and spots 
would he/umarols, already admitted into French 
from the Italian, as their chief mark is their 
smoking in rainy weather. Yet asjumarol has 
been used in a very oon^ned acceptation^ some 
may prefer fumavols^ from their smoke, and di- 
' aiihutive resemblance of a volcana 

Among other causes, of these ignition^nMy be 
joentioned saline ballast and rubbikh of ships, 
which have formed a fumavol not a little destruc- 
tive, near Sunderlaiid in the north of England. 
Pallas mentions a mountain in Siberia which 
continued to bum for a long, period, the ori- 
ginal cause being a pine struck with lightaiiig'j 
which communicated the flame to the rest of the 
fonest, and to the suifaceof the ground. 

M. Morand, in a curious memoir on thespon* 
taneous inflammation of coal-mines, has de^rib- 
ed the singular fumavols or pseudo-volcanoes of 
Rovergue, a district of the former Guienne,, ly- 
ing on the south of Auvergne *. The moantain 

•Mem. dlerac.dc8Scl781> p. ](^. The style i$ embatiassea 
amlobKurev 



acdNmt 



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FUKAVOLS. d49 

df Cransac 19 mentioned in charters^ as boming 
in tbe year 1400; and has been noted in se^raL 
works of geography. The smoke may som^ 
times be seen at the distance of a league ; and at 
night, especially during rain or snow> the flame 
appear^ red, yelldw, or blue. 

M. Morand has given a curious list of the sub« 
stances affected by fire, being chiefly indurated 
clay, or porcelain jaspar; slate of a. brick red, 
often with impressions of veg^bles lasi^ psual in 
coal-mines ; dross frbm oxyds of iron ;.s the dead 
rock of thb Germans, or red sand^stpne; slate 
reduced to impalpable powder; a kind of tufo 
compiMed of powder and sand ; besides 8ulptuir> 
alnm, and ammoniac. ' 

. His acQDunt of the hill of Fontaynes, where 
thtf coal-mines took Are about the year 1763, iti 
curious, and may give the reader a complete 
idea' of a fumavol or tdcanello in its greatest ac» 
tivity. 

<< The hill of Fontayncf, situated near Ca- Hm of Fob- 
Imac, is surmounted by two adjacent houses, 
fbrming the hamlet of Fonta3mes, in the parifh of 
Albin; the lower house belongs to MurateU, 
and the upper to a person named Capelle^ pro* 
prietor of the mountam. The fire having de- 
stroyed his plantation of cbesnuts^ and his coal* 
mine, which was of the first quality; now threat* 



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556 * APPIMOAOS TO THS. TOLCAHIC 

ens Mi h<mse* ; and occupies a mirfiioe <if etiA 
with a slope towaidt the north or north-west) its 
extent may he hi length from east to ilhmt, 
about 65 fkthoms, and in breadth^ firom wnA M 
iottth^ 50 fiithoms. 

<« AU the surface on the side towards ¥mik 
taynes» fariously colonreds but morh partica- 
lariy ^th red^ visibly burnt* no longer regolaiiy 
ftltowing the slope of the mouitam» b entirely 
broken, deranged, furrowed in deAs, in cievieee, 
In trenebes or a kind of small ravines, which aa« 
nounce an interior and pretty de^ eonvnlsiowi 
and, by iw appearance, it migjht be supposed to 
have been lately shaken and otertumed: In 
some places it is hollowed into |^ in oIlMfaH 
is KAed up in smeU emineticeB or little hflk, 
Ibrmed, some of masses of laiige ctnden, and 9i 
ashes, the remains of sabstiRiMB whieh fcafu 
escaped calcinatioa : others e€ Atones, aomistisMi 
in large detached pieces. The variegated oo* 



dates ifoin the fcaot of 1763U bdbfe which the grwitecy who 1 
Sudalia and fiouqui^ only ivorked small coal (ot the fiiiges» eanted 
idl the proprietor's minn to be shut xxp, and woold only alhnr the la- 
hahhantaorthao^uncrf, tpfimikhtheinidhwawahaiiiiwal ifcay 
vaated 1*001 the miae of Fdtfitqma. Iliaaaid, thililiamifiteahk 
nvmber of purchasers not allowing time to raise the aauU coaly the 
inhabitanU taking none but the 1ai;gi: blocks for their use» the vnaD 
eeiA fcmeatdl and todk ira." 



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miiATOLt. 'jyi 

lows of thai fragmeute beloog to those. whuAi 
mn kaown to be the remit of calciiietiov» imw 
w leBB acting mi earths and argiUaceoiu or 
eelMtose rocks^ espeeially of a fernigiaovs na^ 
tare. This dry and disordered surfape p«Qie|its> 
partioidariy towards the eastern side, against 
which the waoke is oftenest driven, the most qof- 
equivocal characters of the completest sterilifyt 
no kind of plant being to.be ISKind thei^ not 
tM leaet verdure. 

^ (3o¥eFed twdvo years ago> as well as afldie p^^f^M^. 
•eighbonring qnarter, with magnificent chesnot 
walks of the first qnality, a second resource fer 
<he conntry after coal^ there remaitts no longer 
any trace of these trees,' except on the lower 
borders of die mountain, eyen in the part which 
is inflamed ; wliere is perceived^ nearly opposite 
Capelle^s house^ a single stump^ still adhering to 
B portion of die trunk dl^ovegrbund. This stump 
and the trunk, hoHowed and mined by the sub- 
terranean heat» are, actudly, only a mishapen 
masSy which, seen from the house^ is distin- 
grrithed by its coal-black colottr> and the smoke 
winch issues from it, as irom a rent spouting 
ifom the earth. 

^ From all points of the surface of this moun- 
taiu, eren from those where ndther crevice nor 
dislocation is perceived^ through asbetf, earths» 



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Mffwankn «o TBI ▼oLeime. 

ffaMiM, which Mm lifted iqp, gato:of tODlce 
mMe or liM dense escape, m from mider the es* 
tingvisbed aadmoking remains of a great coo- 
flegcakion. Thb smoke, accosding to the mm^ 
dispemss by spreading itsdtf over all the sufime^ 
or, in.ca^ weather, rises in clouds asoro Hhml 
MO feefehigh, and is then sometimes ^eeea at a 
great disiaace. 

<^ A just idea may be formed of the bnming 
mass, and of the degree of heat of the bunmig 
wnfi^ of Fontaynes, at the timje that I waa Hiere, 
by the fi^Uowing obseiTation. I .was. tmraffiogr 
towards Albi^, copijog frop VjilenoufCifJar 
Comadsi on my arrival at .Mootm^t^ three 
hours from Fontaynes, I had observed ttiia 
amokes and my guide, from the phM)e we had 
just left, telliQg me he was.no Ipi^er certaui of 
the way, I perceived it, and he songht it; I 
made him observe the smoke of the hill of Fon^ 
taynes, wh^e he had never been, and with 
which he was not m the least acquainted. 

<< In short, another circumstance sensiU^ 
strikes the throat, the smelling, and Ae 9fm^ 
it is the moist and earthy vapour at times sensi- 
bly sulphureous, at some places even suffocate 
ing; the disagreeableness of which is sometimes 
perceived, even on approaching the vicinity of 
Fontaynes. 



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^* Id order tDfumisb myself with an exact and 
CMi^iitte picture of all the parts of this pheno* 
mcaoDi wlMoh had drawn me thither, the eir- 
ci^airtances I hare jast rdated were the only 
OQas, to which i confined my first inspeotion. For 
thitf parpoae* I remained for some time at the 
place wheie I arrived coming from Albin; it 
was directly on the crest of the monntain^ above 
ito ioflained part^ bordering even on the brink of 
thgisoil where its degradation is at present marie* 
ed» Wbatthere most astonished me was» three 
kinds of Inminoos globes (I describe them as Fire. 
they appeared to me), at differ^t distances from 
one another^ in the lower part of the mountain* 
nearly of the same size as the moon appears 
when at the fall, of a bright red, or snch as the 
fine in a forge appears, at the farther end of a 
sntttby when seen from a clear and distant place. 

<^ I did not know what it was 9 I nererthelesa 
attentively observed these brilliant points, which 
I was demred to consider. Do yon see the fire? 
said ti^. 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 



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^54 A^PSHDAOB TO TM TOLCAKIG. 

quiet paisage of a bright and livrfyflame^ ilM* 
teredfrom the wind. The edgi^^ or em Um mi 
coat of these fannehi, reddened by the fire, w mt 
to be blended in colonr witii the flame, ftf wbieh 
they served as conduits, and which was not aft 
first, perceptible, produced that effect«f Kght of 
which I hare endeavoured to describe fhe first 
appearance. When the stones or wood wMdi 
had been thrown towards these burning niotitlw!^ 
reached them, then their coate, breaking aiMi 
felliog into the flame, agitated the fire, causing 
ejections of a reddish hue, to a heig^bt and Wm 
volume proportioned to the derangemmt eaused 
in the furnace ; exactly as it' occurs^ on a somJI 
scale, in the furnace of a bfodcsmith, when ht 
stirs the fire. 

^ If the pieces of the trunks of trees, UkroWii 
on these funnels, were not carried fnto-the tre, 
with the crust of the apertures, they would in* 
stantiy be seen to take fire, or be immediateljr 
reduced to charcoal. 

^ In other places, towards the top of the hBi 
where I stood, and more within my view, the fire 
likewise appeared in all its force, but under a d&F^ 
ferent aspect, and otherwise varied and repeated. 

^^ Generally the tarace is distinguished by a 
light, accompanied by a flame, fluttering from 
time to time on the surface, from a prodijgious 



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awls; - SU 

iiiittiber of little ccevieee, rMher iddenttd, WWch 
eKWnd, in aserpentitie direclioD, to a greater or 
1^8 distanoe. These Kttle crefkes are Uiemselves 
diMitigmshed b}r a contlanc tremUing, peroepti^ 
Me on their edges; the playiag of the flames 
joined to the contimial derangement of the edged 
of the cretices^ which falia in a fine powder m 
the interior of the cleftiS» giving them a partiev* 
iar motion^ whkh cannot be beNer eompared 
than to a kind of twinkling. 

'^ In other parts the fire^ oeaAned m a kind of 
open ravines which are very nnmerovs, strogglet 
agflinst 4he wind, when it blows in the dtiec^ 
tiMi of those trenches ; and forms, to the si|^t» 
a Teal stream of flame. 

^By sounding the earth with my cane, to 
araM those places which were too hot, and re* 
gi#atifig my steps by the wind, so that the smoke 
and snffocating exhalations of hot, humid, and 
salpbnreons vaporn^ were driven before me, I 
had the satisfaction of approaching and examine 
hag at my ease^ among others, a very large cre- 
vice, which, at that time, happened to be bnm« 
mg ; its winding, broad, and elongated mouth, 
was as if ena^melled on its exterior edge% by vola- 
tiiieations of different colonrs, and of the greatest 
ddicacy, which from time to timefdi into thefire. 

^* On the kind of ashe$ which formed the soil 



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tffiS AFPBItOAQk TO TM TOLCAVia 

adf^riniilg thig raviae of fire, sotee* nteHttces 
collected in toler^y large heaps, bofled itp, \Mf^ 
ing the appearance of a briUiant melallisatiott; 
e^feared like that kind of copper called rosette. 
Howrrer difficult the access to those places 
where I ranarked these frothy scorificati<m8» I 
contrived, with my cane, to get by a little at a 
tingie, from the hottest parts, some fine pieces 
to bring them within reach^ and to take them 
away when perfectly cooled. 

** The direction of the wind, th^i^correspoiid-' 
ing with the aperture of this mi^ifieent preci* 
pice, was very fiivouraUe to enabte die ^re to 
exaiplne the extent of the gulf. The ezteraal 
air, agitated by the wind, penetrated into % sa« 
per^cially acting on the flame, and by directifig 
it like a wave, to the other extremity of the bum^ 
Ing ravine, where it became turbirient, and roai^ 
ing, even in the interior*, afibfded the fiu;iltty of 
observing a de^p and void ^pace, a superb fife, 
gf ntle and quiet in one part, undulating in aor 
other, presenting only a bright red, such as is 
perceivable in a glass-house. 

^' The idea which suggested itself at the sight 

* ^' Which hiought to my recollection, what is said by the inha- 
Utants in the nei^bourfaood of the plain of Dysert Moor, in Scot- 
land ; they pretend that, at certain times, they hear muroiaringi 
and whistlings in the holes and caverns* Art d^esfpioiter Us mnn 
ie ekarbon, p. 36/* 



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_J 



of thk object) of divermfying it, of changiiig the 
action of the fire, by throwing different things 
into the precipice^ which sometimes seemed lost 
in an*instant> afforded a kind of amusetnent, not 
unworthy a naturalist Stones thrown bonnd«> 
ing into this farnaoe, prodnced flaming eruptkmt 
with spaiiding^ even with a detonation^ and ere*' 
ated as it were little tempests^ which ga?e 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 posBiUe to approach these fornaces with 
safety^ and without danger throw in large masses 
of any substance whatever, so as suddenly to 
ccMnpress 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; tt 

* *<That related by M. Vabb^ Marie, probably had no other caine 
than the detachment of a considerable part of the earth within. M. 
lAureDt, cuivfte of Albin, informed me^ thai in September last, thit 
jnottntaia in the night had made a considerable eKploeion. The 
noise which accompanied it, was like that of a cannon, the ground 
of the vicinity, to a considerable distance, was next morning found 
covered with stones thrown up by this eruption ; the quantity wai 
observed, and was estimated at 200 cart loads. The surface of the 
hill also showed by its alteration, the conflict within ; all which waa 
caused by a current of water, which had been injudiciously intro- 
duced, with a view to extingwsh the bunung of the mountain**' 



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J|gg APPBHOAOI «• 9IM VOLCAMIC. 

vMBmrtome^ aiidezdtadmy oiiritnlp«ifl|l 
pmnUk Itmny wallberappoMdtthttldidmitr 
oo«£»e nyself to this idle insptctioiii m tmvanr 
iog wilb an ttocertain step this smokii^ and 
boraUig surface, which often obliged me to torn 
iwik one part to another; in walking on thi» 
demolition of substances, to admire, as near «• 
possible, the different apertures of fire, wbi^ 1 
was accuitonied to distinguish ; I fuUy perceivedl 
that those confused remains^ deserved a separaNi 
and detailed examination : their diffefent tints of 
white, ydbw, yellowish, yiolet, greeaisb* or 
other colours that they hare iic<|aiied aocoiding 
to their nature, according to the duration or de^ 
gvee of the fire, made them already raasariEaUe^ 
^ They are all either calcareous^ or fiftrifiablas 
the greater part resemble baked hrick% tome are 
whitened, calcined, reduced to lime» and art 
changed into a kind of red pumioe, or bear other 
marks of scorification in different degrees, some- 
times with mixtures of stones more or less altered, 
M yeined tufos, formed of ashes, and la/dU^ 
agglutinated together. Several of these stones^ 
and in great numbers, are visibly and abundantly, 
either impregnated, or incrusted with salts and 
sulphurs. Here stones of different sises, corer 
thick beds of ashes, reduced by the strength and 
duration of the fire, Jo an impalpable powders 



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still bmpkii^ ia. cfrteap placej^. These aBbeSf if 
they may be called so, heaped sometimes in 
sii^ciog hoUawBf foi^xi very daogerous spots; a 
sti^k oMiy be thrust ioto them with the greatest 
MKie i io going over them» one may sick to one s 
knees : I myself found, thati besides the great 
heat which is ccmcentrated in them, it was no 
litde trouble to get out of them. 

<* The liveliness with which the fire shows \t* 
self^ towards the east and the south of the hill, 
where the trees split at SO fathoms' distance, does 
not permit much detailed observation^ otherwise 
than as relates, either to the fiery spectacle of ar 
considerable surface of earth, or to the aspect of 
a confuaed and extraordinary subversion. One 
cannot approach every spot one would wish. In 
some, at the bottom of the burning part, the heat^ 
is sufierable ; the neighbouring inhaJbitants roast 
thdr chesnuts in it; eyen rsd>b}t6 like to burrow 
in it» and, although the season when I was there 
was extremely hot, I have seen some of those 
animals driven from places coutigoous to the 
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 



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560 AFFBNOAGt 90 TBI TOLCAMIC 

heat which is felt through the boots, becomet in- 
supportable. 

*^ One is then obliged every moment to more 
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 
that the heat of the fire will not allow tl^ tra- 
Teller with impunity to pick up calcined stones, 
or other substances, which he may think worth 
examination. 

^< This burning heat of the hill of Fontajnes, 

seems to gain towards the east and south ; on the 

opposite side where the fire recedes, grass grows; 

' and com and rye are sown within four or fiye 

lathoms c^the conflagration/' 



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SUPPLEMENT. 



VEINSTONES. 



TOA II. S o 



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VEINSTONES. 



XHESE stones have, in cabinets, been often* 
confounded with rocks, from which they should in 
general be careftilly distinguished. They are call* Nwaa. 
ed veinstones, because they are found in the veins, 
either metallic or barren^ which traverse many 
mountains. 

The reader who desires complete information 
concerning those veins, one of the most important 
topics in the science, is referred to the elaborate 
work of Werner*; A few general ideas will be 
sufficient for the present design. 

Most mountains consist of stratified rocks, by Wemei^ 
the Germans cxSAit^ jimtze ^ and the beds are 
often intersected, almost at right angles, by what 
iEure called wins^ of more or less length, depth, aiid 
thickness; sometimes metallic, and sometimes of 
a rocky suibst^uice ; but dissimilar from other parts 
of the mountain. 0{^pel, formerly president of 

^ Kottvelie Theorie de la ibrmation dts F^ons. Tndiute par 

%0% 



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554 tUPPttXEKT. 

the Council of Mbes in Saxony, hfts mfenned us 
that the mere fissures of rocks are commoDly wry 
narrow; while a vein, on the contrary, may be of 
prodigious extent, and is always filled with a sub- 
stance different from that of the mountBin. He 
was the first, according to Werner, who estBfa&h- 
ed the essential difference between veios and 
JUstze^ or beds, which may be metallic and con- 
fain a heterogenous substance, yet must not be 
called veins, as they follow the direction of. the 
other strata. 
Arndi. Many primitive-mountains tam&t of whae b&ve 
been called, with great impropriety, vertical strata 
or beds ; while the latter words of ^[lemselves im- 
ply a horizontal position. The terms orrecte or 
ijf rights bave been here proposed and adopted, 
in order to obviate a solecism long regrrt t ed by 
writers on mineralogy. Such mountains consist- 
ing of arrects, are often intersected by veins, which 
cut these arrects in an opposite direction. 

Origiiu It seems a probable opinion that many y^ns of 
great extent may have been produced l^ the de- 
siccation of the globe, after the retneat of the 
primeval waters; while others. may be owing to 
the subsidence of parts of mountains resting qd 

Estwt an irregular nucleus. At Uspallata, in the Andes 
of Chilis there is a veb of silv^, wfaicfa has beeo 
traced to the enormous lengtii of 90 ndles ; Imtby 



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nuoiy hu been iup)pMed to eitnU 
840 gdograpfaidd miles^ ThegrBiMlYeiiii& always* 
nine feet in thickneis ; but on both aides mimerooft 
veins branch off, which may be said to penetrate 
in all directions a chain of mountains 80 miles in 
hreailik*. From this. sorprising example, an idea 
umy be formed of the extent of aoine teins^ which 
haiFC xmttiiuied to be richly productive after the 
laboors of many centuries. 

In oondnctmg tiieiir subterranean operations^ 
the aofeem use a Idhd of compass, divided into 
twice' twelve hours} 12 and IS. beiag k. and s« 
while f6 taod 6 are s* and w*t This is. used* to 
eatimabe the direction of tiba vein; while. its. mc/^ 
wr<ioi« is measured, by Idle pbmmeL Thed^is^ 
oftenconfoi u nded with the idcUnatkm, but seems 
Hmne prictpeiiy to imply the ^eaeral dedinetion, 
taktain^liie line or direction of therein, thaniAie 
lateral indipation or obliquity. Thus if & book 
be held obliquely, the. back will show the direct 
tion <rf the vein^ which is sddom strictly horizontal; 
but dips at one extremity, while at the other it is 
nfieot;^ or> in the language of miners, banets aut^ 
m rises i».tke. day.. Theiridth^xftfae back shows 

• MoUna, :^ Nat. deKMi. 

f Invented by the Gcnnans, ilie firthen of modem ounenlogy. 
llie flihwiniBet in tfaeHam were d]ioov9redA«i>«o6i« Thow 
«fSny9«l9aHamaaBcr,ebo«tA..p. liSO. 



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m 



Ihe tUokness. of the vem; wtiile Mk ades waak 
tb&dediDatkiD finom.ihe vartkBl thnn^ the 90 
iiof^etB to tbe hocuKXL But a Utde skefeefa and 
axfdlBaation, ghen kiAm appendix^ witt cKpiu 
diis sabject better than any veiiMi deaaiftiuL 
i 'Tbe:reck which ooven the ^oh, is cdled the 
roof^ and tiie bottom b oailed^ tUe sait. Ttmf 
an aim called the hanger and the iodgien' Xke 
Jlnglish miners also usatlie word i^mk, to dooole 
the judjaation : and tkk x)dny to deoolB Ihe.per- 
pendienlar, whik the p^ wmiaf^wedmiBilm ho- 
TeOataL' The veiosfeanea axe JOoietiBm caUmi 
nidersi andthaGeiriiianwQnlibtAi&JBelBteriftr 
anvity.Qceinpty^qpaBetf 

\ i Ilie vem JAsKJkf oo^esac^s.^iiridiL tiieisfxik,. Ink is 
aepaiated from itdJLbotii sides by ifehaft^anjcailkid 
the f AUumif , whiefa^ Uiev^alla, ctrntmiiae »■» 
idk: and often by ithe iiktSy m. Oenaiit Jert^i 
iKhkh am small layers of eiarthy iiiatery:oamaMoiy 
asgillaoBOtiS) lying' bei:«atootfie saibaadi okI the 
)tiek« . in. the i^dns. liiieBQBelvEft tiie oreaaaa ac- 
ebtspadied iiitlstii€ir.g^iiritof qaarta, faorylei, 
CtYiUct. tiakateoua: spaiv' fritJ'^ j^Efaenal aitt xalaat ceaMfMr, 
vhich B {toviei£d.Mnis>ibiB of^flrapditkMial ear- 
tent, so as to appear like chambers^ studded all 
oye|r with ^rte^^^^ or.g|X)up^ of ti^utift4 ^ 



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m 

oeedi all UHit i^eat of oraenttd mMgas&teoxBy and 
Mcm ite: cfaoseoi afaodw of .the fiuries of llie miBej 
n noe<iKhoee existeiioe ^vas axiciccitly cradtted ia 
ail mioenl conakrica* - . . 

Hme cavities are.<ABD found where the Tern is 
noBt poirerfiil, and the sidn tare covered witin dei» 
poailiant af rariouB periods,, whence Werner ad^ 
doaes.them la aupportof his theory, that the ^aina 
mre ODboe empty, and -vere filled iroiii abdve; 
«apadaUy as tfaeer crystali aie eovered oo liiat tide 
laitb lit^ ei^fntals td pyiites, iMgpetic iron, and 
§Bleaa, ivhitib, by his dcletrine, may faavedniiiBd 
from ajt>6ir^ This fe-oppDaad bj the tkieoiry of 
IMra^ jiUdio ibr ^arty. ^earf MperintaiMied the Tteim^idcML 
aiMi^f the Uiettia, Imd fvhb affims that ktetettic 
aeioB aia^tefaied. bjr the: iQkniintatlonn aod.exaltak 
tioi o€ ^apaairs, ^vfha^' we iatfai caH #iiea; aad 
wfakhiopeteq^aa it ana hriUiul of iiidiil ijte iiite^ 
rior of the earth, pferpalinily decotai^oai^ and 
laa i w i aal in fl iwaiofal hiiimailrni* Haamukk^er- 
]mfii \aM iaAlroed. ^wl, dibug^- the gnsbaraod* 
teaii faiiefdli^^.'^diey aaae onageaied, &s^ in dial&i 
laij^'bgF tiK'jailperior coid^ andthealet fidk ibtii 
^kfpniStaon^ Vaiaa sometifaaea qraaa aach other aa 
cUfareht d]MctjDD9T aaid: it aaen)^ idear Ithatlillo^ 

• See his curious work on the Int^iox of MoujitauiSj a foWo 
iK/hiiai tianilgied inio French, by feic^ r i ; * 



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56S 



wfanii eitwiKtcPOM the dktn TOBUche ttni 
OMidefii; tim nciett tima^ bQHi:faDdbn liy a 
later sabgidcnoe of the louiitiki. Wnner in- 
ionns us, that in the wkaag^htiktjatiMeeyberg 
there are two kinds of veinSy of veiy difinmktfe^ 
•cnptiQDS. One kind contiflta of .tiboae irinckim 
called northern and sdnthfim, that la^^tiiqr^ ^^^m 
£Dom nine to tiuoee hours,. aixordap^.to.lfaftflnMrf 
oompaaSy or between tiie north-west adDidthafmrtb* 
^aat .They yidd .galena, black biaBd^-ff^rilie^ 
either coppery, arsenical^ or ofmmmnfiStfuatlMt 
and brown tpar. The aeoond kind ^ ywios, 
alwaya traveiaing the.fifat,)andnerer t a w ca a od by 
tbeniy cqptMns galena witka fittfet iidia ia d pynJeay 
baryta, fluor, and qmutM. TUb.^ 
tbedithaod ninth hctar. One 
veiha of :tii and joi ntwr, die. haaiar but s^tAm ff fi 
tiwreraed by the letter. Thedir^ciia»aethajial 
ia chiofty between six and niaa hoii»);wbilt.Aat (tf 
Ihelaatiisbefewieen nine and three;.. i.' 

Li 4 nore immediate. oonaideiataM of Ihajm^ 
theaaaBlfas, it mi^ be obaerifed that Ihef kmm 
aMftrtimigifr neither. shirts nor «albaadi^>bai pans 
lato-the rock itsd^wjUidim tiMit€wei»;tite 
aomewhat decompoaad. Wener aay%ftbflt«thia 
particnlairly happens wikm rmti, kiadad wlb 
qiiartz and hornblende,^ occur ip a qiiartsy 9MH1; 
and flometiiaes only in gmnmJm jm^m^^ 




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«r bjr Ibo bottg of day. The ove passbig. into 
dK ofaniav^tkinieky smelimes ftr a fewindiaj 
amer mom fiHor a ysrd, is always in a Icftdy ot 
aupcfikiiaL finmiii in diffinront intning disttiets of 
Romany, aaMral nlfer ores are wrong^ in A§ 
cboooBposed gneass of ^ rock adjacent to tba 
aalkandsof.tfae mine; and at Kgngsberg in Noi^ 
maty^ native ^her appear in goaus^ mica-staMi > 
and. hornblende. Copper^ gikt^oa^ &ikI even libi 
iOiBfltanes astome tbe sasie JB{qpeBrafaee# -t\ <>' ^>> 
'•r fiametfanas iragBsmits ctf.die rode have dropped 
itto <i» -WBO^ and been enveiopedr in its snUniaicei 
PaiiiWiliiwji seems to elode a great iSfficnfty, ttid 
rtiailsiiappgarance of masses of' miaemi, by M 
WmmA tilled jmAesor pockets^ wfaicfa ha^e beeis 
MirtfiiitaM/ disoreered at' detadied ktA wide isi^ 
iaiMs, in the solid bo<]^ of the rdck. : ^r: n *; 
juiil^vat not be coooeMtd that all Wins kiie^*ttie^ siMfviiiiw 
taUifiDraas.^ Many, on the contrary, disappovif 
<rf the mnwr, and are found ' to consist 
' of stene. Wetner mehlitos vehisof ^ra* 
poppfayryj Umestone, basialt^' wackiEb,' and 
k;^ Ho«dds, that in some parts of Ste^ 
^ fiEnihd of small-gfi^^ned granite, m a roclt 
^JMicar^hite; imd'thBte reias w traversed: 'and 
fl waaiful, by^v^ds of sily^^ vytdeh prov^ tha^llMi 

&ioth^dis«ietf 



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$70 



fqpipiir.y«att of ^ otf Au ft y and of trtp^ or:! 
<V«ii»«f vackeo ms paitktiilaily-^fi«qti«nt n^te 
iBBtelfie aouBMuos a£ amttmjj;. tUtyutMroae ai 
Ihe otittr metaHic wio*, and vvrofi eoone of t 
taaamniemiakmBtiaa. Vtias d ffomamtp^ 
fear ndur BautMi. ibatfaDBBoanlHM (tf8ckBBe> 
te^ and HartansleB) tlMtearevrioa of da|r<itaia 
in tbe PymiBBB, DdkaBMl obaenfod^natftriiai 
▼•tear thBj^ofOiBBtvirliaCiBaaUrja.faedaffntait^ 
*'*'*** itbautnipe jnchai tiiok, qM^oaed Uc twe n l m i wi be* 



Off trap, which wwc thniiartoPB 
CiMN4»a» of li^oeataoe. <« W««iMerveri.thBtliie 
iaferior hed ofittap diiappeMed, tenHBMlhigJM 
«ii« f<Mto of a imlge,^ ao that DsigHDalBiliftati- 
pud*' rtposefd: te the UmertanK We ate ah^ 
foortd llMltttetlat^ckoampeMtratdl hf tfanadi 
<rfig»ititcf unhibbiiippehrjoa it» ««(fiite,\ai:itea^ 
Bag form ; and the. gramte' ab^ > faaswi»«idw «wi 
of iKidttles, heil% k {dl these drcaiattnjbea^fiftdy 
Mb^)e9t'to,the rock, which supports ot omIomi 
it» fiwmiacr *a^ it « icMitiiraoJBa bbdy^ oMllfaBe 
mrW(»Y TtiaaoB to Mieve that it aever Itea n teil a 
to «ii)oh dqilh, Ihls gieaaite is m-.^'ptt^ ptMt 
ifqnfiosed of jrfatas^f fcbtu^r; waoai or. h a tJimi * 
49^ willk cr}rstalfl isf4rta«k?8eha4.- SIBb Bdesaad 
Ibojqiaarte ene ^nly aeaMenKl^ uSTtM mm-^im 
tP!)f^iD0eired,«aQlibel' . pbea6B)sn«oi&/vie i peraoaeA 
WMny 'tB9k mofe of ^somte, dbontioa ■■ nth ii 



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Google 



$7\ 

It ufipiaa^ ismn the ooAcfauooD, that the Bicd* 
Mif^ tbe d^i ^jeot of tbese obswadons^ b .«» 
tiiielyisDait'Qaed ni primitbe XDcks^ in diskbctand 
€fliiti|imiwi.bcd% fir pr<qpiBrly tepecta, indiiwi "fautt 
6& l0«6O^>; tfae,«iiperior bed]^ imiMdiately eowr^ 

aib«¥e (Wiotbt: tat imQieroil9 mltacnaliiig beds^my 
anecte of liamtone, trap, iiod smefimes of . gnat 
nifaii I3»diqpoBil»ii of tiie ti$p is mnarkaSle^ 
•tit ofin JoSkcti^ lietureen tiro leul i»ed& of lioitii 

BJWl^fat iippeigMice> Tfat^gtV^iite «f ti&^^iqw 
nor beds or arrects presents many features^- aa m 
wmi ^^^ cfao4;«id.^jL i io Uali li w iiit ^iaBtiofiatoy 
aiUMKMltdmKJb(tf>bi^n[«bft^i«^^ 
$MNL^*^dte-.O0r«M} mb'if it-Mi Ijeen depiosilad 

« a$c^ of gmpdtOr mofotei ofi qiuBpfK,' ^L^ah) 
Mldililul;»«u% jhiffrfe.^^ boaai doiseraU l»y fit& 
iltayilloltodyl]|teiIi^U a eh^jsUltb: Tha^ 9if ^ 
%4ilaiK5rllit^liaacboin^ti^^ aad kti QbafMada» 
9Wiit^f«iricfiailiia^^Bbbodrii^ ilTUBiyania 
ladM^iriqr U^gelaM: ifreguM ijri^pu micmkmt^ / 



* Joafiila^]|lhMitrlv»t5t.76u 



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578 



•tSQce ^ino remarlml by Ddomieu, wha 9aj^ thait 
such granites differ from those of the mountaiM^ 
«3 tiie ^caii^ are lai^, the subrtancM less kiier<^ 
woven and coher^at^ while each has a greater ten^ 
Aeocy to r^;utar aryatallisation, Bot, on tbif 
other hand, Cbairpentier observed,' hi venous ptifet 
of Saxony, veins of granite in iiiouiitBiQ8;o€ gDO^^ 
the granite consisting of white quarts in very i 
gpains, mica in fine particles, while:the febpar 
SG8it:eIy disdngniahiBtble from the qvaric*l 
SM* 1^ ^^H^ or (fykes found m coed nniei^ mtf 

idso be dassed ankmg the vems of stane; Tb^y 
ohkflSy consisty OB abeady meotkmbii .of* bataltift 
and basalton, day^rod^i and a r g H airiwwis 



Bat the denondnation of viAatttboes faaa^ 
siore strictly confined to ihe subatiuMea ftMfcd M> 
metidttc vems> which, from their omfiiteiwMM% 
perhqB nn»e properly bclmg tp lililology^w 
only a few observations are here ofiered, byiM^ 
of suppleihemlr to a tcssEtiso oQiodDB; w ^ttej 
oAen perplex the kanier, and aometihies eton tiM 
ad^ by comfaiQBtions vrfaich do not ocdwli 
iMwiinlain inasses> A-short^accoukoftfaMavenh 
atones, g^ven b^ an honest practical odnar, tatf 
AMMBtby naft be unaoQsi^^ ""Whafcltidl 



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ifi a compound nuneml concretion of mioiireo^ 
lours, appearances, and degrees of hardness, and 
BOt unfrequently of various colours in the same 
mass, thou^ white often prevails. This com* 
pounded stony ooninnfcion is called by mmers a 
rider, perimpa from its riding the veiu, ac sepa^ 
ratkigit loogkudiQaliy into two or more di^isioilii 
This mineial stone is hard and heavy, sooietimM 
compact and solid, but frequently cracked and 
cavernous, rising in irregular and mishapen masses, 
aodigenetfally exceeding hard* A ridio* fine^uent- 
ly cpntaiiis a variety of different substances -or 
spedes, aswellas different colours^inthesamemasg^ 
Mish\88<spar, quartz, fragments of the' rocks near 
the vem,,' sometimes pyrites/ and often ore in graini 
ttad^flewers^andsometinies difieient ores, as lead, 
copper, ter.ffi the same maA, and all these atrm^ 
)y coagulatedoor ^^oncmted together by a whitish or 
a brownish^white substance, resemUnIg quartz and 
Cigate, . whidi seems to have enveloped the several 
articles in the compositioik when the whole was in 
a fluid state. I call this veinstone, as 1 tfamk the 
term should be the most intelligtble to naturaliati, 
St being always found in vems, upon tlie sup»- 
ileie& of them, and. in fragments and masses lyii^ 
abolit upon die ftce of the ground, which bne 
slidden, or been forced off, the superficies of veins. 
But the veinstone dot« not always contain so great 



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5r4 



a stakty in its ctmpmitkm. It is oflni jnronjr 
Hfiiitey and appears like a qnartzy conereticm of n 
poronSyCr rttb^ a cavernoas textote; and tiie isk* 
sida of tba caverns, tinonf^ small, freqaeidiy oon^ 
taios a brcmniiA £Qrrugim)us soft soil of a saai^ 
a|>pearasice; aod sometimes tbe inttdea of tliead 
smilcaipeniaanBfiiidy lided wkh great nuaben 
itf pointed or prismotical crjstalsy geoecaMy ex^^ 
aaediag baaatifiil, and sparkling like dknxnida^ 
Bnt all the irdosfames, or ridefs, aie not white nor 
Mtfaitiab. In many places tk^y are of a brown, or 
a>raddirii-brown, and scFeral other cokMuis; hot 
thfi wfakifih colour most ccnnnuMily preraiU^ 
Steong wide yekis often contain alarge rib of tide 
TcinstOQe betwixt the sides, several feet thidc; but 
ittall degrees of thickness, from a few indies up 
tp several feet, I have 'seen stnmg boUi v^b carry 
sodi a rib or body oi this stone as to appeser in n 
ridge above tfaesurfeceof tfaegroundagrtatw^y 
tbe.sapeirfides of the native rock being withered, 
and wasted away from bodi sides of it.''* 

This de8(xiption dearly applies to quartz: audi 
be afitorwarda proceeds to nation that the chief 
spars, found in mmeral veins, are tiie cakareoua 
aod oaukrtqpar, since calkd barytea. The soft 
auneral iaoib fennd in veins, are a wfait^ or idil^ 

•WUIsnvMia.Kaia.usS4. 



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575 



bofo; ftf^doaetaoasfemi^Mwiclay; iritkcfOxx 
kfaids and colouvs^ especially that called gur by Ow. 
tfae Germans, of n^arious tktts oi brown, and tt^ 
eemblk^ v^PP^ ^^ BCMmdtimeA Spamsh snafii 
Tbit peach of the Cornish naBecs, chlorke, or 
^paen b(^y is also frequefift 

From the aeeount which WiUitfns gives of tkt Bider. 
riSeTy in.tiie very imperfect niiiicra(ogical language 
of that period, it would appear that he naeans M 
iadieate a vein of feirtiginoiis qutfts, generally 
found to Acc<»npasiy metajljc cnres. By 'fail d^ 
MfipiacHd it ia Tery Fotigb and irregular, and fen 
of little cavities, Containing a ferruginous poivder 
Uk» fiimff. The whitest parts have some resem^ 
blaoce to what is called a bur'Stone^ chiefly used 
ibr fliU^tone% their kregular surface serving the 
]p«nrpo6e of trituratiofi : but the rider gm^tdly 
contains heterogenous snbstanoes, as ores, pyrites, 
•par, luor, &c.* It seems o£ten to appnDach 
keralite, or the hornstein of the Germans, whi^ 
IMKaetiknte even forins mountains, replete with 
aftvar and other ores. 

It would seem that the cavities eoBfeaining druses 
of BOMdl oystals, chi^y occur m the pmrer pov^ 
laiM of Ihe nick ; and his accou&t of tins beantifel 
kind ^ vebstones merits transcription* 

•WflLLaiV. 



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57fi 



LodM. . ^'Most of the nttoeral spani/«ro frfytuwUly 
found shot into ptismaticaly cubic ImagODay^ ip* 
othor figures. ISiese \figured ccystak o/e 
jraUy transparent^ and very bewtifiil. It ia a | 
curiouty to bjebcM the iitfide of same of the l«r0^ 
cavities in which they, are formed* These opea 
T jcdjrorns are frequeiitly met wkh in hard mineral 
veinsy and they are generally called by mioem 
lochs^ or loch holes. 

*. '' The miners know nothii^ of ^leae cavenMHtf 
jfscuities until tbey Strite into tbeou as Ih^ all- 
yance in working ; and they are of vJnr^mjijfrtcifc. 
^ions, from the bi^ess <^ a nut, up to .rocwi 
enough for three or four men to turn thetnselvei ia 
them. .J 

^^ The magnitude of these caverns is geHqrnBy 
in some proportion to the capact^ of the veiaa ip 
which they are found; and the insides <^ them 
iinequently exhibit all the rariety, beauty, mi 
splendour of the most curious grbtto-wock. \ . 
.. ^' There is commonly a hard concreteA stw^ 
crust, called.iilru^e, adhering to the inside of Om 
cavity; out of which, as out of a rool^ ao iuui^ 
merable multitude of short pristtiatirad tryatula 
are shot, which sparkle like a tlKXtiWud.'diftinniKip 
with the candle, or when broi^t .up to .t|K^ aiitL 
Between these clusters of mock diamonds, and 
sticking to tiiem pramiscaoasly, there are oftm 



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tft1HfT01tB9. ,577 

ore, pjAttBy and spar, shot also into prismaticaly 
cubic, and oAer 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- 
thnes most magnificently adorned with the tnost 
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 
e^ttrs of polished gold, of the rainbow, and oi 
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 an<tglari£ii]iL hilt when there is less' or more 
of yellow copper ore, or of the pyrites in them ; 
as tiiese ores are found to produce, in luurd 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 GaBoiray. 

^^'These mineral loughs^- or caverns, are the 
great source of materials for grotto work; and the 
specim^ coUected from the mines are generally 
ttie most sfa^wy dazzfing article m the whole ar- 
raa|;eiiient of the splendid grotto/'* 



VOL. II. S P 



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Wimuif 



Ftom tiie plab dMaib of this fagnert mner, it 
also a{^>eftrs that tbd rider often ariaes Hke a vnH 
Uk the middle of the veini the ore besigfouod cm 
either side; while sometimes, on the coDtrary, 
the ore is. in the middle, aud tfae rider on each 
aide; or, to use the ttuning language, the hanger 
«nd leger, the hariging or upper side, and the 
kadtJig or low^ side ; for the hade, shpe, or mdi- 
nation of the rw is. chiefly estimated by miners 
from the low^ side, while the dirtctUm is by them 
called the bearing of the vein. The back of tiie 
yeb is also called the basset. What the Germans 
call the best^^ b described by Williaflis at a tfaiii 
seam of clay, by the miners called a steeking. 
He baa observed two rich veins of kad-otc, oa 
1^ w}es of a rider Of whiostone or basalt Some 
veins have little or no rider, but only <»e and 
spar*. . . 

Another sUbstanoe, not uncomnion in ffm, is 
1^ diamictdnic oombinatidn ti s3ei( and iron; for 
there are few mines in which iron does not ieodm* 
pany tiie oi^ metafe. 

This s9€i3( mu9t» /acc(irdio^ to tho doctrine of 
Wero^t, be ofiten of jeceot formatlta* But atfr^ 
la«titea of i^ex may'bis jmd to b6 daily formed \sk 
the deepest gallery^ oCiji^jfiiiiMs of Ci^Ha^ tad 

• lb. SQ9, M^ SOI;^ asi, 377, S79r 



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rSiHflTOICBS. S79 

are reooArkable, when they have attained several 
iocb^.of length, by then* extreme flexibility, while 
calca^^us stalactites are broken with the slightest 
eflrort*i In hils account of his own cabinet, Trebra 
ma^tiwHis that, in 1782, a peasant dig^g his gar* 
4^a }n the village of Seppenrode;, dependent oh 
tbe bbhopriq of Munster, found a grey flint, about 
nine inches in length by four in foreadtii, having 
nothing particular in its exterior appearance; but 
having broke it for his tinder-box, he found within 
Ik cyli&dr ji^al cavity, containing twenty little piecef 
of silver, which appeared to have been tied with a 
thread) of which. some vestiges were apparent 
The cavity was exactly moulded on this little pil* 
pf coins, and the inside was black ; but the most 
eurprising.cb'cumstance is, that the most ancient 
of tbe^ ccnns are only of the sixteenth century. 
Trebia's cabinet contained a piece of this ilint; 
tod one of the cioins presented to him by Prince 
Gallitsan, with an authentic certificate of the cir«- 
cmostances above-mentioQedf . Mr, Kirwan haa 
another example of coins found in flint:}:. 
In his ]ngd woifc on the interior of mountains^ 

* Joum. des Mitm, No. id^ p. 76* 

t IWd. p. 75. 

{ Geol. Ess. 447« where he hriefly quotes Schneider, Top. Mln. 
lUjfor 126 sUver coins foQod in fiinto at GriDoc in Denmark, and 
an iioa nail at Potidnu 

SpS 



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$80 



Stl»»Lftll«]lt. 



Trebra had before stated a ftct more applicabkM 
the present subject, and observed by himself in thi 
sojne called Dreyweiber, in the district of Marien* 
berg. In 1777, on enlarging and opening that 
mine, which had been under water for' two hun- 
dred years, four standard posts were found, fomn* 
ing part of the fabric of an ancient pit. The 
lower ends of these posts were buried in a new 
.vein,' consbting of barytes, of a flesh colour, and 
of green fluor. Moreover, the extremities of these 
pieces of wood were covered with a black and 
brown ferru^ous matter, contsioing much vitre- 
ous silver ore, and native silver in extremdy thin 
kaves*. From these and oth^ examples; it may 
be inferred that substances, reputed the most 
primeval, are in foct daily produoid by nature; 
and that the same Fowec which has impressed 
auch wonderfol and perpetual motioo on the 'pla- 
netary bodies, also ammatwij so to speak, their 
interior; where to .suppose absolute death and ia- 
lertion, would be to.ccmtradict idl the other pheoa- 
mena. 
AgeofTeiB. According to Werner, the most ancieiit wins 
present felspar, schorl, topaz, and beryl. Those 
which yield grey and green mica, are also very 
ancient; while the calcareous stones appear more 

* Jour, des Minob t. aWw 



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vsntttrosxB.* S8\. 

modem ; appetite and some fluors being the oldest 
of this description. Barytes seems one of the 
newest substances which appear in veins. Quartz^ 
if not the most ancient, appears to be of aU ages ; 
while wacken and basalt seem to be recent. Trebra 
has observed, that certain gangarts <seem 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 gangarts of chalcedony and jasper, which are 
seldom found in granite and gneiss. In argilla^^ 
ceous mountains the prevailing gangart is calca* 
reous spar^ while barj^tes 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 
chief gangarts are quartz, trap, fluor; the libck 
hemg almost universally what was called petro* 
4ulex, more probably homstein than febite. The 
direction of the vdns is very various ; and thoae 
that are north and south somietimes have their 
mcUnationio the east, sometimes to the west"'* 
Among. veinstones must also be reckoned bridas^ 
-composed of fragments of the mass of the veirn^ 

• See the tabk^ Joam. det Mines, it. f^l. 



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ind alleged by Werner, among liis argumtets, 
that the veins were filled from above. Such js a 
bricia, consisting of little fragments of faarytes in 
, a cement of bluish grey fiuor. But he particular* 
ly instances the celebrated bricia of agate^ found 
at Schlotwitz near Kunersdorff. This ra^kar 
Agate bridiu and beautiful stone consists of large and small 
fragments of a fine ribon agate, which forms a 
powerful vein in that spot; the fiBgments being 
joined by a cement of amethyst and qtsurta. In 
the polished specimens there are fragments, of 
which the parts correspond so exactly;, that it is 
evident that they must have dropped from the 
same portion of the vein* 

Among singular veinstones oEiay also be classed 
pebbks. pebbles. Werner mentions that a vdn of pebbles 
of gneiss, fourteen inches. in thickness, was foilnd 
at the depih of 180 fittboms. In Hessia, a vein 
of cobalt, almost vertic^ was traversed by aik^ 
ether vein consisting almost entirely of simd and 
gravel. At Chilanches in Dauphiny, several 
-veins are e&tErely filled with rolled pebbles. But 
one of the most remarkable exampleB is jep drted 
by M. Duhamel, m his Subterranean Gdometrf • 
Tlie principal vein of the mine of lead contBining 
^ silver, at Hudgoat in Lower ftittany, ' is accom- 
panied, as well on the roof as on the sole, with 
ten or twdve feet in ihidcne^ of rolled stones m 



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pebbles, of various sizes, eifiier round or oblong; 
the greatest number being of qnsrtz^ like those 
found on the shores of the sea, and in the beds of 
rivers ; while the intervals are filled with a white 
earth, sometimes ochry. The works are 500 feet 
under the mountain, and the inclination of the % 
vein is from 60 to 70 degrees* Duhamel adds, 
that the disposition of the vein admits no doubl 
that it has been fbrmod after the bcmks of pebbles, 
which ^erve it as walls : and that it may be in* 
ferred that the two banks of pebbles were at first 
united, and ^dterwards rent and filled witli this 
vein. But may it not be simply a pudding-stone, 
of which the cement is decomposed, a common 
eCTect of metallic veins* ? Nor is it wholly incon* 
ceivable that the vast receptacle of subterranean 
waters, known to exist in many parts of the glob^ 
may contain extensive beds of pebbles, which 
may be forced into any cavities by the prodigious 
power of earthquakes, or other phenomena, occa* 
sioned by the extreme force of steam, vapours, 
and gases. 

Among the most remarkable veinstones must 
also be classed petrifactions, which have unez<' 

• Daub. Theorie de Werner^ 83. Near Gieenock in Scotland, 
ore is found in pudAng-ttone. WSl. L 368. 



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584 svtvLsiiBinv 

pedsedly h^ea found at gireat depthsl - Bera 
assutes us that petrified plorpites (a kind of mol* 
lusk), h^ve been repeatedly found in a mine oi 
Hungary; iat the depth of 89 fittbcHos, or 534 feet. 
Fichtel has also observed, in bis work on the Car* 
pathian mountiunfi, that in the mines of Hungary 
has' beto found a fun^te as large as a nut^ the pa^ 
rallel leaves containing a little ball enchased in 
the iirterior,the subfttance hrapg now spatfaose iron, 
of a deep brown; and it rests on crystaUised 
qqartZ) covering the decomposed porphyry, called 
^axum metaUiferum by Bora, and iMsre styled 
boraitei in honour of tfant g^^at minoraloi^ 
There was^ also found a bivalve shell, (tf the sise of 
a filbert, likewise placed on quartz and boinile. 
yi^ two valves were separated- firom each other, 
but entire. Fichtel adds, tiiat he has in his pM- 
session a cochlite, or sea-snail, found in a vein of 
gold in Transilvania^. Might not even tbeap 
relics arise from subterranean waters? 
OecompMed Finally, among veinstones may also be dMsed 
ihose decomposed rocks, generally occnccuigin 
the proximity of metallic veins, and which having 
a more immediate relation to the present work, 
must be treated with scnne detail. 

• Wener, Tbfiod^ d(h SSa 



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VBivtsoma.* 5%S 

< Werner has infonned us ttrnt, in namy vmtis, 
the rock oo both sides, or, in the miners' Ijan* 
guage, the roof and the soUy the hanger and the 
kger, 13 altered and decomposed. This accident 
diiefly takes place ia mountains of granitel, gneiss^ 
mica slate^ ,comfnon slate, and porphyry. But 
this decomposition seldom extends to more thaa 
pne of the con^tuent element;s of the rock ; for 
t)ie quartz remains entire; while conunonly the 
l^spar, dten the mica, and very <^n the horn* 
l^eode, are (|ecayed ; the potash of the one, and 
the iron, of the others, beiog very liable to decom* 
pppitipn^. This alteration smnetimes extends a 
cxmsiderdUe way, even a fathom; and k not 
always upparaot plong the vein, but chiefly m 
ibose parts where the mineral abounds with sul- 
fj^viT. In U^ pursuit of a barren vein, when this 
decomposition begins to appear,, it may be con* 
ehKled that ore is not far distant 
. . This change Werner ascribes to acids in the 
di68o)ulion that formed the vein; and supposes 
that the felspar is changed into kaolin, or white 
day^ by the carbonic acid ; and he ^ves examples 
of gneiss and granite thus decomposed. He also 
supposes that the sulphuric acid may aflfect the 
mica and hornblende, and convert them into that 
green bole or lithomargg, which was ori^nally 



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586 tomBiiBNT. 

cAlled gneiss by the Saxon miners/ before the 
term was transferred to the entire rock now so 
denominated. 

liaubuisson, in his able translation of Werner's 
work on Veins, has given two remarkable exam-- 
pies of the decomposition of granite, which may 
best be explained in his own words*. 

^^ Near Bautzen, in Lusatia, in a hoUow way, 
there is a cut made into a granitic soil, which is a 
mere assemblage of balls of granite, mostly a 
ftitiiom in diameter; while the interstices are of a 
granite, decomposed to such a degree that the 
^ot resembles a gravel-pit The balls are cover* 
ed wil^ envelopes, consisting of many layers <^ 
^nite, also falling into decay. I observed one 
ball which had thirteen of these envelopes, each 
nearly an inch in thickness, and the more decom* 
posed as they were distant from the kernel. A 
ball detached frOm the mountain, having split in 
the middle, afforded me an opportunity of observ- 
ing the nature and structure of that kernel, which 
consists of a fair solid granite, of a hardness and 
freshness of colour, demonstrating that it has sof* 
finred no alteration ; nor does it present any fis- 
sure, nor any lineament of a structure in conccn-. 

• Thcmrle, US. 



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„^ 



trie liters* Fbr these cireamtaBces I diall that 
accoant The granitic rock being divided mta 
ttwuses by horizontal and vertical '£snires> asmoik 
granite are^ the decomposition ariaing from 1^ 
atmosphere would first afint the an^s and aides, 
and reduce them into that land of gmtel of irfaidi 
we haTe spoken^ wittle the mstsses of conof sor 
svLtoe the htm of balls* The deeompositaoo^ 
afterwards penettutbg gradually into their intoiioi; 
would successively relax the tissue, and thna^fisriti 
concentric layers ; while the kmioBt part wdtild 
continue to preserve its solidity, thus forming the 
Icemel. One of the effects of the decoaapoBitkm 
hcis been the oxydation of the iron in the iUspar^ 
Whence the red colour of the gravel, ef the eoa^ 
centric layers, and all the decayed parts; whiles 
in the kernel, the felspar is of a very fresh bluidi 
white. This oxydation of iron, by Hbs codmiQii 
influence of 1^ atmosphere, is the cause of seirenal 
atppearances in rocks, particnlariy the sandslbones^ 
in oae of the. bails, which was on the surfiieeof 
the earth, the upper hemisphere of lag/ers was eii«* 
tirely wanting, the fresh aiki solid kernel beiof 
displayed ; while beneatii it was enveloped by tbe 
lower hemis^ere of decomposed ia^ers, tlK nppar 
havii^ been carried away by the winds, nins» 
tad other meteoric influences. I report Itts ftct 



087 



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388 mmLKmtwv. 

88 leading to the remark, that altfiou^ certaia 
masses^ peaks^ rocks, &c. which we see bare,, 
always present a very hard substance, seeming to 
defy all decomposition ; it is neverAeless subject 
to the destructive power of time, or more strictly 
speaking, of the elemaits; but in proporticm as 
the particles of that surface are thus decomposed, 
they are washed away, so that we have always 
under our eyes the solid part, not yet affected by 
decomposition. 

. *' The seccmd example which I shall state, ap- 
pears at the Seiffenwerk of Steinbach, near Johan- 
georgenstadt in Saxony. When I was there, and 
in front of a mountain of granite, of which the 
sur&ce 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 of 
quartz had the same coloiir and the same form as 
in the granite of the neighbourhood, and were dis- 
posed in the same manner, but in a felspar com* 
pletely decomposed. Ttiis decomposition peoe* 
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 fiuhomft ; 
and I am persuaded that in many places what ia 
r^aided as gravel, produced by alluvion and 
transference, is only decomposed granite in it* 



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■ „ii»^l^^»"W W 



Timtromib S89 

tnigiDal situatioQ; and that iindor this pretaoded 
gravel would be fimnd the solid rock* 

*^ I shall not here eolarg^ on the destructiire 
power of the elements, but reserve the subject for 
another wQvk; where I sbedl show, by a series of 
&cts, its cQDsequences in gramies, sandstonesi 
basaltSy and- almost all ,the rocks« I shall shoqr 
tiiat acting constantly, and without interruption^ 
during a long series of ages, it must have pro- 
duced very great effects on the solid crust of our 
l^be ; and has strongly concurred in fieidhioning 
the inequalities, now observed on its surface. I 
shall with regret be obliged to combat the opinion 
€>f Dcdomiai; the vivacity of whose imag^iation 
could not bear the slow and uniform progress, 
which experience shows to be that of nature. He 
4nid he could not believe that a rivulet should 
l»ve scooped out large valleys : but I must ob- 
serve that nature has time entirely at her dispod- 
tioii; and that a finite efiect, produced an infinite 
imiri>er of times, is an effect infinitely great" 

It is hoped that these observations vnll be suf* 
fident to direct the student of nature in his atten* 
tkm to veinstones, which, whether in mountains 
or m cabinets, have often been confounded with 
neks. In the latter, particularly, they have some* 
times led sunendogjists, and even geolo^bts^ to 



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lacmmf^ 



^m 



inexafit and erroneous infeienoes. But, in ftr 
rapid advances of the sdenoe, the lamp of obaer- 
▼«lioot?ill soon dispel any obscurity; and wheo 
fietcts shall become suffidently munerous^ it is to 
be hopod that soma future Newton may arise, to 
dispel the darkness and confusioQ which stffi 
prevail in many parts of the nmieral kingdoBL 




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APPENDIX. 




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f 



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APPENDIX. 



No. I. On the ancient Manner ofcaroing Granite* 

Z0B6A9 p. 189; «t seq. 
[See die translation. Vol. I. p. 199.] 

ReLIjQUUM est dioere de Barberino obdisca 

Nempe ad eum scalpendum instrumenta quedam adhibita 
▼identur quorum in magnis Obeliscis nullum deprehenditur 
vestigium. Que enim lines sunt recte^ vel ad circuli seg- 
mentum curratse, non acut6 incis» sunt^ neque profundi* 
tatem habent equalem : sed ftindus ooncavus eaty ipsi sulci in 
medid 8n& parte proftindicwes^ ad extremitates sensim ex* 
tenuantur> donee peuktim evanescant Nee desinunt puncto 
definito in eoloco> qui terminus est rei quam representandam 
sibl sumserat sculptor, sed exilior pars procurrit extra 'limites 
iigurae. 

Unde clarum fit ejusmodi sulcos non factos esse stylo nee 
smyride lamind cultriformi subacti, sed serra aliqu4 lunat&, 
cui subjieiebatur smyris, et altemo motu inddebantur sulci. 
Sed in rectis lineis; ubi vero curvs essent, serri etiam opus 
erat curvd. Quoniam vero figurs incavita te eminentes tuigi- 
diores sunt, et singulae part^ aliqua defbrmantur globositate, 
probabile fit eas teretro vel tubo fbrmatas esse smyridis sub- 
sidio, licet ejus instrumenti vestigia non appareant, figurarum 
superfide f ricando escpolita 

Universim in hiigus dassis operibus tempus lucrifkcere 
studuerunt artifices ; et serris, tuctris, atque fiictione efficere^ 

VOL. IT. 2 Q 



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594 AFrivmau 

que in magnis obdiicu cieIo fiMta videotnr, «d myride 
laminK luljecta 

6. Nostrates ubi gnuoito figunmn aliqiiam incidere vokatA, 
primo loco exemplar ejus fociunt, A ferri landnft subtili, qak 
super piano saxo applicalo ac velnt agglutuiata« aasompta 
altra lamina, brevi coltio aimili, ea atuntur ad sukom dn- 
^niii^pi ; ope smyridia circa exemplar supradictum. Solco 
autem ad certam profonditatem impreaso, exemplar anferunfc, 
et spatiummilco definitom^ acuto scalpzo (kMriq) coimninuere 
in^piiiilt. Dein maUeolp mucvonato (^wgotoj fooHBre 
aggrediuntur figuram • . • . quam postea malleoto latkne 
fimarteUmoJ molliorem reddunt et Ittviorem. Quo fiKsto amy- 
ride plumbo fubact& lanrigant. Dcia exiliara fineameata par- 
tim scalpro coebTe a^iiciunt, partim lamini cultiifonni et 

,, imiftida* Poetvemo veto omnia expoUunt flByride fpiantifr" 
aima quam ^ottngUa Tooant 

7. I>clBoB90v«at]giadepfAeiKiiiia'«MinCNMliacoIb^ 
, pcriitano; nequeeiAehoQinitrumeiitodMne^^ 

in aam grankico contendil : led loqui Tidetor de n lU 
inteUeclL Nam ipommunja itr^ri (tentraa id. q. tmpem/^ 
nnllus uauB sk in <o lapide, cum ftsfo at ipse durior. 
Alteram vero tereiron, quod ^tt&tit est «n«ttf,8mjrideciBcuiiia» 
gend» diNitinatur, licet oommodum instrumentuai, tamen 
minimi est neceiaarium nee nisi in pKipfiiodii cxcamtioiiibai 
eo uti Solent nostrates. 



No. n. Illustrations of the ancient Jlfarb/es. 

Whitx. Parian, also called Lj/cknites and Lfgdis. 

Pymettian. , 

Premunt coluraBW vltims iscifpf 

Sor. 



* 

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PefUelican. 

MylauUm. 

Proc(mnetum. Tomb of Mausolos. Fitruv, 

ThoMtan, 

Coralitm from the river Coralius in Phrygia ; also called 
8angarioD> from the river Sangarus ; resembling ivory. 

Phoenician, Tyrian, or Sidonian, from Libanns; used in 
tbe Temple of Solomon. Josephta. 

Arabian. Dipdorus says, that in weight and whiteness it 
esoeeded the -Parian. 

L$Hfkm» gr^h whUe (Palombina) s abo dark grey. 

Conchiiei, white with shells. 

Black. From Tanana in Lacoi^ia. 

" Qoidve doamt prodmt PhrpgiiB iamn eohimniiiy 
Taenare uve tuis, sive Caryste tuu." 

TOnilL 

** Quod non Ttenarib 6aan$ est loSii iiilta oolnmnH." 

Pnptft* 

The green was from Mount Taygetus. The Crocian was 
probably white, as statues were formed of it. 

Lydian^ (Basanite.)* 

Gbbev. Of Blount Taygetus in Lacania, which extendi 
through that country to Arcadia ; (herde aaticoj 



** JUic Tti^eti vjrent i 

Mart. 

** £t qiod vinn£ finite kvit Eafotas." 

^ Heic dam Leconam 

Sea ▼iient.'* 

* The etone of Alabendt in Guie, black bclining to pmplei wip OMlted. 
•nd wed for gbw (Pl>oy)f ^ ^^"^ not be e marble. 

S q3 



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596 APPENDIX. 

•* Heic et Amydni cmtam de moote Lyeoigi 
Quod virer 9 et mollei imttatur rupibai beHMt." 

Id. 

** Herbotis que vernant i 

" Post caute Laconom 

MannorU habosi nditns intenrirrt ordo." 

Td, 

Procopius de AEd. compares it to emerald. 
In a noted passage, Sidonius thus describes the duef 
bles of antiquity : 

" Hie Upis est de q;iiisiqiie locby daof qniaqiie eiAonB, 
MthiopuSf Phrygios, Pariw, Poeoiu, Laoed«Don, 
PuiporeiiSy viridisy maculoraa, elmroiity et aUNM." 

African red, Phrygian spotted, Lacoman green, Parian 
white, Poenus like ivory. 

Carystian, green, veined and sp5tted, also called Euboean. 
As it was spotted, it is probably the verd antique sanguine, of 
a deep sea-green with little red and black spots. It was 
most probably a serpentine, for amianthus was fbond in it, as 
is clear from a passage of Plutarch. 

" In some countries we see lakes and whole riven, and not 
a few fountains and springs of hot waters, have sometimes 
failed and been entirely lost 5 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 else run hard by. And so of ipetal mines, 
some have been quite exhausted, as the sflver 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 cold water, as the poet JEtch^Uu tells us, 

* Taking hi$ moord a ti^ Euboean hUtie,' 

*^ *Tid not long since the quarry of Carpitui has ceased to 



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APFBN0IX. 597 

yield a certun soft stone, which was wont to be drawn into a 
fine thread} lor I suppose some here have seen towels, net** 
w<Mk, and quoi& woven of that thread which could not be 
burnt; but when they were soiled with using, people flung 
them into the fire, and took them thence white and clean, 
the fire only purifying them. But aill 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 quany."* 

Atraaan, from Atiax, a town on the river Peneus, not fax 
from the celebrated vale of Tempe, in Thessaly, whence it 
was aJsQ called Theualxum, 

The ancients included all the rocks used in sculpture or 
architecture under the name of marbles ; but the verde aniicoy 
which is really a serpentine marble, is mentioned by so many 
ancient writers as the most cheerful of all, with veins of a 
grassy, appearance winding in a spiral manner, and present- 
ing white parts when polished, that no reasonable doubt can 
be entertained of its being the TjMxmian sort. 

F&ul Silentiarius, in the sixth century, wrote a poem, in 
which he describes the decorations of the fiimous church of 
St Sophia, then erected by the Emperor Justinian at Con« 
stantinople. The subject led him to a minute description of 
the most celebrated ancient marbles ^ and that of the Atra- 
cian, contained in six lines, may be thus literally translated. 
'^ Whatever the Atracian land produces in the plains, not in ^ 
the high mountains as the other rocks, in some parts of a 
light green not far from the colour of the emerald, in others 
proceeding to a deep and fidl green. There is also something 
like snow added to a black splendour 5 all which concur to 
form one beautiful whole." From other passages of ancient 
writers, it appears that this stone is described in the mass, as 
bdng of a leek green) whereas the Laconian Is mentioned as 

* Piatuth*s M<)nl TreatiBes, iv. 54. Toornefiirt, Tnveb, i. 176, men* • 
tioDs amiaDthua from Cuysiiu, u being now an inferior kind, imposed on thtt 
ignorant aa plumose alum 



% 

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h6\hg of the cdotir of tender beHM or ghjA TMte ducripb 
tiotis can scarcely be more justly applied than to wtaot Int 
been c^led green porphyry, the erroneotls ophiiei of many 
modern authors, the ba^^e being of a leek green, while the 
crystals of felspar approach the emerald colour; and It is 
bften spotted with white and black chalcedony, and in othet 
instances with white felspar and black siderite. This bettiCi* 
ful stone seems to have been discovered ader the empire waa 
transferred to Constantinople; for it escaped the andeDl 
classics, and continues to be celebrated from the time of 
Justinian, and that of Basilius the Macedonian, to thet of 
Eustathhis in the eleventh century, who mentions it, in the 
k)ve story of Ismene, as quite distinct fi*om the Lacotdaa. It 
has been generally supposed to be from Egypt ; bat is net 
specified in any of the recent descriptions as being Ibuod 
in that country, where the red porphyry is not ancommon^ 
and is found in pebbles in the universal brieia. The great 
inasses found at the harbour of Ostia, only prove that it waa 
brought by sea to that sole port of Rome*. 

Red. The Rosso Antico, The andents seem aometimei 
to have confounded red marble with porphyry, whidi wai 
quarried in the Thebaid. But statues show tliat red marble 
was also found in Egypt, or the adjoining coui^tries; and it 
is highly probable, if not demonstrable, as already explained^ 
^*t that the Augusteum and tiberianum of Pliny alluded to ttiis 
red, purpureus, or imperial colour. One Idnd of tlie Hoaao 
antico is fiorito^ that is the Augustean ; another all dotted 
over, the Tiberian. The colossal statue of Agrippa, formerly 
in the Pantheon, now in the Grimani palace at Venice, if erf 
Rosso antico. 

YxLLOw. The PhtnU^^an. Paul Sil. says yellow and gold 
(LAimachella Castracana?) and found in Mount Maurausis 

• Wad has one Egyptian relic of wbtthecalli green poiphjfiy, a sctrabenas 
hnt it is of hornatone. 



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(iMaufasiitt ct Attfftdltis). It was ako fbmid ipdtt^d With red 
and white fJfncanofiorito. Rezziato.J* 

** Sola Qitet AatU Nomadum decisa flaetaUis 
Purpura." 

Sua, 



S99 



** Heic Nomadum luctiit iaVchtia liKA.'* 



^ Nomadum lapii addimr istii^ 
Antiquam menthna ebor." 

Precisely the GiaUo aniko. 



U 



Sid,Jp6lL 



Bluish Gkbt or TusaviN. This, as well as the pure 
white, was found at LmuL Straho. (Bigio.J 

Variegated. Phrygian from Synnada, the PhrygiuM tapis 
of the classics ; white, with red veins and spots. 



' ubi narmore picto 

Candida puipureo djstingiiitiir area gyn).** 



** Puipoia aoUy eavo Flirygfae quod Syniiados antio, 
Ipae craeatavit maculis lacencibuft Atjk" 

SImL 

The spots either rose colour or deep red (Fiore di PetiicOy 
Gpolazzo, CotoneUo, Porta tanUtf.) 

* Tbe Gialh Anmdaio ot rii^ed marble may be alluded to bj Hby^ igtxr. 1. 
\thtt% Ite sp^a of egg (igUKs bring anificiany iiuerted. 

What is called African Brlcia is quite coumon even in Xagknd, and b 
qmrried at Saravezia in Tuicanj, pneaefiiing kige piecea ti hnrnn^ feddith, 
and white, on a black ground. There it no ancient authority for itt being 
African. One kind, however, resembling the Fvort di PersUoy Biard, 348, 
rightly conceives to be from the same quanries, that is, Synnadic or Phrygian. 

t Spedmens of two inches of coone vary much. linger pieces would 
better detenntne the kinds. dnHaf like OvMfoi in gemsi sooMtkaes Only 
implies a beautiful marble. 



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600 AF»IU>IX. 

AiWMikM with gdden qwU (Mipeatiiie with Bic^ Ooeki^ 
dipanHmefJ 

C&rinthian, JUnm, yellow with spots. (CaneUof Peifaaps 
Giallo e nero.J 

Ckian, black or dark with. spots. (Pavonazzo? OcMo di 
permeeTJ 

Jud^Bon, flame colour (Darataf) 

ToMffmenum, variegated. That of Taormina in Sicily (Red 
spotted with black, or a deq»er red) or veioed ^th white> 
BrocatelloneJ. A1so> greenish with red spots. 

Gibbon, tiL 190, describes fixHn Paul Silentiarius the fol- 
lowing marbles of St. Sophia. 

Garystian, pale with iron veins. Phrygian. 

<3arian from Jassus, veined white and red. 

Lydian, pale with a red flower (a JioritoJ African, of a 
gold or 8affix>n colour. Celtic^ black with white veins. 
(Nero € bianco*.J 

What marble appears in the ruins of Pailmyta^ 



Some further illustrations may also be offered, concerning 
the ancient petnJogy of Egypt. 

Plato, in Tinuto, describes an Egyptian stone as composed 
*" of red, yellow, white, and black. It is the noted granite of 
Egypt, says Garof. p. 4% Red felspar, yellow or white 
quarts, black siderite. 

The pforonion, 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. Pausan. Eliac. 518. 

Eusebius, lib. viii. p. 420, mentions that Christians were 
condemned to labour in the quarries of porphyry in the 

* The black and white Celtic tmy be gimite. The Itfit speculum 
be talc. 



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** 



>PPSM1>1Z« 501 

Thebais. Paul SiL aays it was broug(ifc down the Nik in 
laige veaeels. 

Some have inferred tlie woid 6aral^ to be of Hebrew origin, 
as in that language hanalt or barxaU implies iron, Bellon, 
IL £^. sajs he saw a pyramid of basalt as hard as iron. 

Ptolemy, iv. 5, says that the eastern part of E^^pt, on the 
Arabian golf, was possessed by the Arabs ; and amcmg them 
were the quarries of k^ Tmcus, alabastrine, porphyry, 
black st4me (basalt), and of basanite. Herodotus, also, ii. 8, 
mentions the quarries in the Arabian chain. The town of 
AlakastTcn was so called from its alabasteri and Porphyrio 
from its porphyry. See Garof. 32, 



Ko. UL 1%e value at Heme of Specimens of ancient 
Stones*. 

Falore di Marmi, AktbastH, Pietre teneree dure, ragguag* 
haio alpalmo cvhico Romano, . 

Marmi e pietre tenere* 

Sc. btj. 

IManno bianco di Carrara, ilpalmo ,, 70 

Greco „ 96 

nero di Carrara 52 ,^ 

antico, detto Tulgarmente di para- 
gone 8 „ 

giallodi Siena 2 50 

detto Porta Santa, antico 5 „ 

detto fior de persico antico • 14 ^^ 

detto Settebase semplice antico ^. 2 „ 

a rose antico 4 8 „ 

giallo antico.. •• , 7 ^^ 

in masisa gran<le » 8 „ 

• Pctnni Gabioelto del CoUegio Nazareoo, torn. ii. App. Tavola xi. The 
Roman piJm b about nme jncbes. The tatdo (which contunt one hundred 
bqjocaj U about 48. 6d. 



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«4 



602 Mravmx. 

* 

Manno verde aniico di bella qualiti ...« m. i5 ^ 

m^naBBagraade.... «•«. 90 „ 

rofieo antko « 4«...«...«...*.«*4«»«*»....« 19 «^ 

in massa grande, moUo raro** »• 5t4 ## 

Affricaoo ^ 4 — i 50 

dpdKno « «••••••—•»••••••• ,^ 00 

bianco e noro antico.« •••.•••«.«.«^ • 30 ,^ 

delle codte di Francia...-.*.* ««.«.*.,^»..« 8 ^» 

Ketmvolgannente delta MaliiiodiPolceresra^ ^ S SO 

vcrde Pratcf.. „ 3 >> 

Porto Venere con madcliieglaU&«...« 2 50 

Breccia corallinaantica ••••.- 5 „ 

di Saravezza 2 50 

di Franda...., ...*, >... „ 50 

/ilabaiiri. 

Ahbastro Orientale *. , 20 ^ 

e pecordla antico ^30 „ 

diS. Felicitaosia Monte CirceUo ^ 4 „ 

di Polombara e di Civita Vecchia ^^ 2 50 

di Montanto , 3 ^^ 

d'Orte bianco ^ ^^ 5q 

biondo del fbsso deUa Penna 25 „ 

Pietre Dure. 

Cranito roAso delle Guglie ^ ^, 50 

in massa grande.* 3 ^^ 

Egiziano nero con macchie bianche roasigne 3 „ 
bidnco e nero antico^ volgannente detto deila 

Colonna del Signore g ,, 

in massa grande ^ 12 „ 

porfiritico^ detto porfido rosso 8 „ 

in massa grande ^. 12 „ 

praaino, detto porfido Terde......^ ».. 8 „ 

in massa grande^ raro 15 ^ 



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Apmion. 608 

Se. bij. 

Gnokitovoiftto •«••••••*«••••*•«•••••«••*••• ^•••••ff*«MftM 6 $$ 

•teatitko, detto Tolgamente Gramloiiey 

bianeoeTtfrde....* • • 6 „ ^ 

Grtnit^ki« » 50 

Basalte nero d*£gitto » * ^. 10 ,« 

Orientale Ten^... r — ^'* » 

Verde di Mtani^ volgariDente detto Serpeittino antico 3 ,% 

Bieteitt d'figittodi fondo Yenfioo.**** •••••• ••• 8 «» 

I soprammentovati prezzi si aumentano, non solo in pro- 
porzione della mole, ma anche della bellezza della pietra o 
manno. Cosi, per esempio, il manno detto Porta Santa se 
abbia colorito piu acceso ; il verde antico se sia de maechie 
bianche e di verde pienoben rUevate ; e il granito porfiritico se 
sia di color di porpora vivo^ con grani di felspato bianco rom- 
boidale j avranno sempre pregio maggiore. 

No. IV. Account of the Hill of St. Gilles, 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 left, with the coal passing under it) firom Genette : as 
in.the plate here reduced, Dom. VI. 

The height of the hill is 3200 feet ; and it contains sixty- . 
one beds of coal, separated by other beds. Many of these beds 
of coal and intermediate substances are composed of smaller 
beds ; and, without doubt, the lowest beds of coal have not 
be^n discovered. 

The beds of the chief bill form a concave curve ; but after 
passing under the Meuse, they become horizontal under the 
little hill on the left They afterwards risei, and become 
almost vertical. 

On the other side, or right hand of the print, they are bent 
like chevrons 5 while the intermediate beds assume the like 
form. 



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$04 APPBUPiX. 

f The beds are intersected by three great dykes, called /oiUef 

in Flandersj crawu in France, iprungi or le^ in' Germany. 

The first, on the r^t of the chief hill, is thin towards the 
, summit, but thickens 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 hiD. 
Some are 420 feet thick at the depth of the lowest beds ; but 
probably they thicken still more as they aj^pniach the radicsd 
rock. 

All the beds of coal, vfhich 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. 

Tlie mass of these dykes is chiefly of rock*; others of 
sandstone, of agaz (that is, a ferruginous sandstone) j or of 
earth, with here and there broken coaL 

Beds of the Hill of St. Gilles, which continue for wore 
than a league. 

1. From the surface to the first bed of coal, 21 feet, (The 

Liege foot is 10 inches French.) 
Thickness of this bed of coal 15 inches. 

2. Intermediate bed 42 feet. 

* Second bed of coal 1 f. 7i* 

Divided into two by earth nearly an inch thick. 

3. Intermediate 84 f 

Tliird bed divided into two, 4 f. 3 i. 

4. Intermediate 49 f 
Fourth bed 1 f. 7 i. 

5. Intermediate 42 f 

Fifth bed*! f. 3 i. In three layers. 

6. Intermediate 56/. 
Sixth bed 7 i. 

• Such if the raguc bngiia^ of Gcnttt^' 



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APPBHDnE. (05 



7- tiUermediaie 56/ of aw. 
Sereothbed^f. 3L 

8. Intermediaie^lf. 

£ighth bed 2 f. 2 L In three layers. 

9. IfUermediaU98f. 

Ninth bed 1 f. 3 L In three kyers. 
la LUermediaie 35/. ' 

Tenth bed If. 
11. IiUermediaUmf. 

Eleventh bed S£3L 
19. bUermediate 9Zf: 

Twdfthbedl£3L 

13. Jbtiermediaie 21 f. 

Thirteenth bed 1 £ 7 i* In three hyen. 

14. Intermediate 9Sf. 

Fourteenth bed 4 £ In two layers. 

15. BUermediate. 

Fifteenth vein 3 f. 3 i. In two layers. 

16. IntermedMeSef. 

Sixteenth bed 3 f. In three liters. 

17. Intermediate 42 f. 

Seventeenth bed 3 f. In two layers. 

18. Intermediate 91 f. 

Sixteenth bed 1 £ 3 L Tn two layers. 

19. Intermedwie97f. 

Nineteenth bed 5 f. 6 i. In two layers. 

20. Intermediaie42f. 

Twentieth bed 3 f. In two layers. 
91. Intermediate 9Bf. 

Twenty-first bed 9 f. 3 i. In two layers. 
99. /Mteniiedtale 49/ 

Twenty-second bed 4 f. In two layers. 

93. Ja/emiediale 98/ 

Twenty-thbd bed 1 £ 7 i- In three layen. 

94. /alerwediole 49/ 

Twenty-iburth bed 1 £ 9 L In two layers. 



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25. Intermediate ^f. 
TwQDty-iifth bed 1 f. 2 L III two ! 

26. Intermediaie84f. 

Twenty-sixth bed 3 £. 3 i. Jn two l^tii* 

27. IntermedkUe'M^f. 
Twenty-seventh bed 2 £ 3 i 

28. Intermediate 42/. 
Twenty-eighth bed 2 f. 3 L ""• 

29. Intermediate 98 f. 
Twenty-ninth bid 5 f. 7 i. 

3a Intermediate ^Af. 

Thirtieth bed 3 f. In two layen* 

31. Intermediate 49 f. 

Thirty-first bed 2f. 3 1 la tbrpe byvi. 

32. Intermediate 94 f. 
Thirty-second bed 3 £ I» two layim. 

33. Intermediate 70 f. 

Thirty-third bed 4 £ 7 L latwolayvn. 

34. Intermediate 4^ f. 

Thirty.fburth bed 1 £ 3*1 In tbree byeijk 

35. Intermediate 70 f. 
Thirty-fifth bed 3 £ 7 i* 

36. Intermediate 91 f. 
Thirty-sixth bed 3 £ 

37. Intermediate 3Sf. 
TMrty-5lventhbed2£7i. $0 two kfcis. 

38. Intermediate 98 f. 
Thirty-eighth bed 1 £ Ift two ]»ye«f . 

39. Intermediate 14/ 

Thirty-math bed )l£ 5 L U two lagmip. 

40. Intermediate 49 f. 
Fortieth bed 7 i. 

41. Intermediate 56f. 

Forty-ant bed 2£ 3 i. Iatvo%W|. 

42. Intermediate 42 f. 
Forty-ieeoDdbed4£Si. la two }«f«ii. 



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AFVWBiX. ^ fiOT 



43. Intermediate 49 f. 

Forty-thini bed l^ L ^ 

44. IntermedkaUejf. 
Foity*terthbeddfl 

46. bhtemediaU 4%f. 

Forty-fifth bed «f. Intwokym. 

46. IntermediaU 21/. 

Forty-sixth bed 4 f. In two layers. 

47. Mtfmediate 106/ 
Foffty«M¥eiith bed 2 f. In two kyeis. 

48. Intermediate 70 f* 
Forty-eighth bed 7 L 

49. Intermediate 7 f - 
Forty.ninthbedlf.3!. 

pa Intermediate 7^ f. 

i^ftiethbed4|L 
51. Intermediate 7/ 

Kfty-first bed 1 f. 3 L 
i%. Intermediate ^Sf. 

FUty-seoond bed 3 f. In two layen. 
93. Intermediate %Af. 

Fifty-third bed 3 £ In two layciB. 

54. Intermediate 70 f. 
Fifty-fourth bed 3 f. 3 L 

55. Intermediate 56 f. 
Fifty-fifth bed 3 f. 3 L 

56. Intermediate 84/ 
Fifty-sixth bed If. 7 i. 

57. Intermediate 4!Z0f. 

Fifty-seyenth bed 2 f. 7 L In two hyers. 

58. Intertnediate 105/ 
Fifty-eighth bed 1 £ 

59. Intermediate 126/ 

Fifty-ninth bed 3 f. 3 i. In two feyeil. 

60. Intermediate 154/ 
IM^iethbedl£8i. 



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S08 APPEITDIX. 

61. Inipviediate 196 f. 

Sixty^^first bed 3 f. 8 L In jbi70 layers. 

All the intennediate beds are of argiUaoeous or calcareous 

ston6. These substances also often i^f^iear in the thidaieas 

^ of the coal beds. Sometiines these beds are dbided into two 

or three layers by houage, or black clay, and by geamtrax, a 

kind of aypelite *• 

This enormous mass of coal seems to form a continuaticm 
of those of Huy, Namur, Anzin^ Mons, Tonmi^^ Valen- 
ciennes. ^ 



No, V, Strata at Portsoy, Scotland. 

[From Mr. Jamesons Mineralogy of the Scotkh Islands, vol. ii. 
p. 270, seqq.] 

'' We now continued journeying along by the sea-shore, 
that we might have a better opportunity of discovering any 
interesting appearances which were to be observed. The 
clifi continue to Sandside to be composed of nearly vertical 
strata of talcaceous and micaceous schist u§ j but upon the 
south side of Sandside I observed a considerable stratum of 
steel-grey, foliated limestone, which Hcs upon an ardesia, or 
primitive argillaceous schistus, and this ardesia 3pp<?ar& to be 
covered by a breccia. As the sea covered the greater part of 
this rock of breccia, I could not deferrhiae with certainty its 
position with regard to the limestone. After passing this 
stratum of limestone, which, we were informetl^ 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 Pbrtsoy ; and in 

* AmpeKte, Brongn. i. 561, is ilamloous slate tod black diatk. P. 



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609 



thit ntentl cbsenred 8tnte of talcBceoos^ mamooB, and 
homfaleBde schistus, akii^ating with each other*^ We now 
walked to the t€fwn, which we fawad to be irregular and 
dirty. 

<*• As the rocka upon the sea-shore near to this tfvwn are 
¥017 interesting^ we agreed to stay aday or two, and esamine 
them particularly. I waa the more anxious to do this^ as 
they have long attracted the attration of mineralogists) but 
their particular gtognostic chanicteis have never been de^ 
tailed in any publication. After having examined these rocks^ 
the IbllQwing is the result of the observations whic& I made. 

'' About a quarter of a mile from Portsoy; at the place to 
which I had traced the strata in coming into the towtt> the 
talcaoepus schistus appeared in vertical strata i and nearly at 
the same place I dbserved a stratum of white marble, which 
ia marked £> in the plan at the end of thisi volume. It is 
about twelve feet wkle, and runs south-west and north-east^ 
which is in the same direction with the bounding 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 Jhis stratum succeeds a vertical stratum of 
micaceous schistusf, 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 contact with the next stratuin> 
which is serpentine J. The stratum of serpentine, marked G> 
which succeeds to the talcaceous schistus, is of great widths 
andj like the other strata, is nearly vertical, and runs in a 

- « • Thit mafble it njiite, or ckmdtd with iteel grey } but it It bqcIi wH^i 
with scmkt of talc.'* 

*< f The talcaceous schistus, which alternates with these strata, has some- 
times so much the appearance of compact micaceous schistus, that it cannot be 
distingwsbed from it: and as it approaches the marble, it b to be observed 
mkud with it, aod passing into it." * 

** X This serpentine is of various shades of olive and blackish green. Its 
fracture, which is either uneven, coarse splintery, or even fine splinteiy, presents 
caziaiy-greeti scales. It is intermiied with various fossils, as asbestus, indurated 
steatites, talcite of Wiilerius, calcareous spar, and inm pyrites.** 

VOL. II. 2 R 



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610 




tod thb, with its gieoa ooloar, gMt tt a 
TWs ilmftnm u boudiiL ^ ft stntun off t 
Hj which is afanost ^itiMy oompoeed of qourts* ivineitii 
InoaatacCwitbthtMfpBntinBi batasi 
iHiitimi, wkkik h nwUt, it hM man of tlie i 
mctar>aiidii alio tnvond by vaiaa of quarts. Thai 
of marUe, I, it front 16 to 90 *et wMa$ 
fa«t it of a had qodity, and wW not i 
purpott. It htt^ i nup cta td la k» pitcai of qpnrtt and ial« 
caoeouB tddttut. lb thitttiatomtiioGoedtathiiitlnliimof 
foaita) and thU again is bounded fay a thin aintnn of tal* 
etoeoot soliirtot^ K. Both these atala an only n fttr ftet 
wide, and are sQooeedtd by a stfatnm of maibie^ I^ neaiiir of 
the sane width with the fDnner stntum, L IbthisnaiUe 
tooeeedsa gteat ttratma ctf setpentia^ M, ^Met k citim 
tame natort with the ttratnm we hate bciiio 
Thit tUatum is boonded by hombkadi lodLtt N^ 
Itanntthe rockt that tnrround the haiboor of Vo&auf, and 
ocmtiAuet beymd it towatds a bay, the name of whkh I da 
not leooilecA ). it is travened in several ptoees by lalas of 
grtnke, wUoh ran in diftfeot dixectiont, and vary In biatdlh 
from one to eight ornine feel. At a little ^slaaoe torn the 
tide of the bay I have just menticMtcd* anoHKr atatmn of 
ttrpentlne, mtrked O, mtioes its i^ipearaneei andtakagtin 
aoooeeds the hornblende ioek> P, whkh it timwned fay leint 
of granite (. 

<' We now walked along the shore by the bottom of thii 
btyi and upon its opposite side, in the plaoe of the 

* Qolte die wwnt in xhit dtecch. 

*' t The hornblende rock U geneaStf 9A3mott, urf faui 
of bfown miee intermfaced with h.** 

« X The eegpentine, ee it eppioseheB die h n w I ikii J B wdit ^wuf t P» <n M! f 
inteittbced with It, end at l(wt u not to be dbdqgnishAd ftom H.* 

<« ( Betwixt PortMgrhubourtiid the bi7fdieerfedwille»biiKl 4 
deteimioehowltUty, widireipeaiediBoAcrTMla} aodntlhsven 
eetteditiathephiu** > 



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jawmmvu §11 

roek, iktam mk niggei dift of wiflieeoin adilrtiui* 
which 18. Id some places alternated with quartz, and m othen 
t g aym a d by 'o oiwi de r i hlB granite iwinw The micaieaMs ach!a- ^ 
tm wmitfiineB eontaiiM gametaj and the gnnite, whieh^ia 
gwatigtainad, firequantlir conlatiiB ctyatala af achmi and 
iBiea» and flenutiniea k haa tiia appcanuioe ttaafc ia called 
fimtt gMfhiqufi. Sipdi a|ipean to nae the disfpoutloii aari na* 
tvffe of the strata upon the ahore at Povtacjr*. 

** Aa the gaognostiQ duoraotero of the aerpantlae at tWa 
plaot areioAeiestijig, i tfhall here naantion ^ farthe informatfta^ 
of mj raadaia, a ter IhqtB, whiqh show that ppctty nespiy 
similar appearances have been observed in other countries. 
Zobtenberg, in Lower SUesia, consists entirely of serpentine, 
in whicli some hon)blen<ie is fo^nd, an^ its strata are peatly 
ireiticalt- In the Miner's Ka|endar for 17d(^> Kohl^r in- 
fbnns UB t^t fierppntinis ai^d priqiitivp liioestone (meol^c) 
are neairly allied ip thqir j^ognostic charactfsrs, an4 tl^t 
soipetin^es |hey are disp^isect in strata which alternate. We 
are also informed that serpentine rests apon gneiss, an! even 
alternates with it t, and also with quartzy talcaceous schistus §• 

'' The appeaianoe of the veins of granite traversing horn* 
bltnde lockaad Bucaceous acUatoa, is by no means unomi^ 
mon in Scotland 5 and in other countries similar appearancea 
have been very often .observed. The pimiFe gft^ique has 
been observed in Siberia to form the sides of veins where the 
topaz is found || ; but at Sebritz it is disposed in beds with 
the comipon granite^} and in the Uvsdian mountains Her* 
•anan observed it mixed with the common granite * ^, Patrin, 
who found it in'Siberia witti the topaz, ooi^eetures that it 

** • Some travellen are of opinion that the •eipen^ii^ and maihle fynk ^r^t 
fdm, mther dias ?eniaA stnta." 
H^ 4 Seri. BMbacht. SftS." 

** t'Qwuaatiw Uinm^yimkfi ^m^fwihs wa ilniwutniiiii LMi4i/» 

<« § N. Nofd. fi^ti^«. 149." 

|| Jpyr. de Ph^iqae, Ano. )79l. 

^ N. jBergmaniuMi9> Journal, B. 9. 443. 

— Hennas Minera1o{gf ichf Beachreibung det UiakischeBOibiiigf*. B. 1. 144- 

S B 2 



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r 



gljl AFFBKD1X. 

may generally be considered as indicative of the presenbe of 
these gems. 

*^ Having thus examined the strata upon the shore, 1 
walked into the country for about two miks^ but could ob- 
serve no trace of the serpentine, or marble, or talcaoeoqa 
schistus \ but in several places I observed the hornblende rock. 
I Qscended a hill a few hundred feet hig^$ upon the »de of 
it were masses of hornblende rock and gneiss scattered about, 
but towards the summit it was entirely composed of sdiistose 
quartz. This is a rare rock in Scotland^ nor has it been 
observed but in a veiy few places upon the Continent*'* 











ii 


i 








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O 


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2; 


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No. VI. Further iUmtratiom of Miagite and NioUte: 

[Translated from Faujas, Essai de Geologie, Ftjis I80g, 
tome IL p. 679O 



ORBICULAR GRANITE OF CORSICA; 
Discovay qfthe Sue qfthu Stone. 

In 1785 was discovered in Corsica, on a small ejninftncfi 
with a level summit in the plain of Taravo, an it?<qiM'*H and 
rounded, but at the same time unparalleled block of lare aad 
extraordinary granite with globular crystaUisataons, which 
deeply excited the curiosity of naturalists. 

If, on the one hand, this discovery was interesting, to mi- 
netalogists; on the other, geologists readily comprehended 



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APPENDIX. 613 

that an insulated block of stone, the oi^ganisation of which 

possessed a character so forcibly pronounced and so dififerent 

to that of other rocks^ might, if the spot where it was found 

were discovered, point out the distance it had traversed from 

its native place to that whither it was removed in the shape ^ 

of a rounded block. 

Messieurs de Sionville, Barral, Dolomieu, and other natu- 
ralists ^iter them, made long and vain researches to discover 
the orbicular granite in its original situation. The search 
for it seemed to be abandoned, and specimens of the first 
block, djEpersed in cabinets, became every day more and 
more rare; and when any pieces of it were exposed to sale, 
they obtained very considerable prices. 

lit the month of May 1809, that is to say, twenty-four 
years afterwards, M. Mathieu, a captain of artillery resident 
in Cobka, distinguished alike for his military tidents and 
hk taste for the study of nature, while traversing the steep 
granitic mountain by the side of .the village of Sainte Ijucie, 
'seven leagues distant from the spot where the first block was 
found, observed attentively a saliant mass of rock, entirely 
covered with Jichens and moss, which concealed its external 
character ; but the interior texture of the stone being acci- 
dentally displayed by a break in it, M. Mathieu was agreeably 
surprised to find that the whole mass consisted of orbicular 
granite, similar in composition, colour, and mode of forma*' 
tion, to the orbicular granite w£ich had so long and fruit- 
lessly been sought: other masses, contiguous one to the 
Qther, and in a similar manner covered with lichens and old 
moss, occasioning a presumption that they might be of like 
natiffe, M. Mathieu tried them .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 Roccanerra, that this dis- 
covery was made. 

A& the point the most essential to geology here is 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 



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fSl4 ATBEnOlX. 

ifBB ft)rtiied> it k neeessai^^ fully to ellicidlite tBii BAattcf, tb 
know that the mauntaia of Samte Lmcie is g^ntrftUy oon^ 
paued of a greyish granite^ con^ting of qwttt, §ehfp^g and 
mkskj and that it has an eletation of abbut 600 feet *« 
Let vm suppoBe the obserter to b^ plac^ on th!b suriunit of 

the mountain^ where blocks and masses of grey granite hm 
barei soihe df them saliaut aUd afi^ted in a slight d^prdt by 
timei^ froln this point he is presumed to take his dtfnimir^ 
As if he would deseed by the side of the mountain which ap* 
InrentJy slopes towards the village of Sainie Ltwie, 

His way thto lies over the Same kiiid of grtinitic r6ck Untfl 
160 Ibet belpw the sUtntnit whence he departed, meaBiiriB|^ 
perpendicularly ; in the rock he passes over th^re is nothli^ 
but qiiarts, l^spai*, and tnica Withoht hornblende. Wften 
kt this distance bdow the summit he WiH notioe a dilmge ia 
the rock, which insensibly passes t6 the state o£ bottMiodt 
rock of rather a greenish black c6tottT» mausdi mMi moA 
whit* fblspar> compact, but in A slight degtee gcanMilatod^ 
and somewhat sukiikur to totique black and ^rtute grabita of 
a fine graita. 

As the obterver advances over this differing ^ttce fat wiH 
begin to perceive the first attempts at globular crystalliaation 
in the solid rook 5 shortly aftei^ he will discovei' a ptwttjf 
huge mass, harder than the knothef rock^ Which lisei to a 
oertaiii height, but at its base Adheres to th6 bornUeade 
rook below. Tliis first Mock presents globtiks of differtnt 
sizes, the spherical form of which is hdvanc^ to a moke pw* 
feet and regular btatc than in the crystAllisationi previoutff 
noticed. 

Filially, at but little distance fh>m thb fitst miss 6f gfeba* 



* TfaeM inMhM^lv^ detiatt I h«v« frooft M. Mithieu bhtaMlfi whoii I laA 
ihe flhuntt of «eelag at I^tfi■, dn hit itaj to HoRind, whither he w«» piiig^ 
Older of the roinitter. He was kind enough to comnranicMc to mc the y o Mtlu n 
of the mottiitain otSainte LucUf to dnw a sketch of it, and to mark the pWca 
where the globular gratdte ia situate ; and at his request it if, and nith hia pcr- 
nissioD, that 1 publish thii A«&mnt, to stfft u a supplemfedl fo wfast I bift 
ifcid of tfat Gfbituhr grabite 6f the pbin of Ttmv». 



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APfpsmmb 015. 

kr ffasntB, nHhun are fimnd of oimOar iiatitf6» mom or kai 

teliant, but the number of tbem k not great. M. Mafthiea 

imagines them to be a species of kemela much more sdid 

than the hornblende rock ifhich gate them birth *, and thai 

thlf> not being of a composition equally hard* has been unable 

in an equal degree to resist the action of the weather, and * 

oonsequentlj, becoming gradually deoon^osed in part» haa 

left the orlncular granite bare. 

The space oocujued by these rfngnlar productions, at least 
such of them as are exposed to sight, including that filled by 
the hornblende rock, is about a hundred yards ) after whidi 
the ordinary granite reappears. 

M, Mathieu, not content with simply affording me in* 
•tmotive informatkm respecting the discoNrery he had madc« 
was so kind and liberal as to enrich n^ collection with a 
aeries of beautiful specimens of all the varieties of oibioultt 
granite he had collected on the mountain of Sainte Lucie. 

I here annex a short descriptioa of those which appeared 
to me the most interesting. 

Na 1. A specimen, the thickness of wlddi is one inch and 
three lines, diameter four IndMs, of orbicufer granite, re* 
aembling as well in composition, shade of colour, and hard* 
fiess, as in the form of its globules, that of Taravo, possessing 
alao like that some small brilliant pohits of a substance 
mppsrently metallic, and of a silveiy white colour, which 
a&oU the magnet, and belongs to the ctess of magnetic 
pyrkes. This substance takes a beautifiil polish j grains of 
this description are not numerous, but distinctly sprinkled 
4n the mass, as well as in the globules themselves of this 
granite. In evety respect, in shoit, it seems a similar species 
to that of the vaUey of Twpooo; but M. Ibthieu informed 
me that this beautiful variety is not fineqnent 9 it eadsts, how* 

r, in Us original s&te, which suffices. 



No. 9. Oriileidir gimite, the oomposltloa of iriiidi li 
theaasK wkktbatof the gratute of the plain of Ttraoo, but 



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the giobnles of whkli, of much gnster size^ ttne almost tm» 
tirely white, owing to the predominance of the Mspur of 
that colour, and the ahnost total absence of hornblende, of 
which only very slight traces can be distinguished. White 
^obules> like those on the black ground spotted with white, * 
* of whteh this granite b composed, produce an effisct as !«• 

markaUe ai it is extraordinary. The arts Blight reap gnat 
advantage from it in the formation of certain monumental 
which would be the mcwe attractive of notice as the Greeks 
and Romans, so solicitous of employing the most corioua 
granites, never knew this species.. As, according to M. Mia-» 
thieu, the largest blocks are of this variety, they would con- 
sequently furnish the most considerable maases ; in order to 
transport them, all that would be required is the making ft 
road practicable for carriages, from Mount Sainte LAide to 
' the Gulf of Vaknco. 

Somelaminse of mica, of a bright brown, are seen in sma^ 
patches, in certain parts of this granite. 

Na 3. Another variety, remarkable on account of the 
ground of the stebe, Mrhich is of much deeper colour, owh^ 
to the greater iEibundanoe of hornblende, and to its partklea 
being more divided, and more equally mixed with the grano* 
lated febpar, which has received a tint from it of greenish 
blade, that gives the stone, which b hard and receives a veiy 
beautiful polish, rather a gmve appearance. The giobuks in 
general are of inferior size, and dbtinctly marked, and tka 
lightly greenbh tint which shades their white drdes hKmon 
nites with the ground c^ the stone. 

Na 4. I know not whether or not we ought to consider as 
a fourth variety that in which the globules are of equal siaa 
with those in the preceding, but in which the ground b dif- 
ferent; being more rich in febpar than in hornblende, and 
speckled with white and black in a very dbtinct manner 
and without being mixed, so that the white spedcs predoaoi- 
nadi^, the ground, fiur from being so handi as in Che pre* 



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GediDg, ii Ibety; ivfaflt infixed leaders this flpednMi atift 
more pleasing, the globules, being tinged widi an exti«mety, 
lights bat evident shade of blacky have acquired by the aux-% 
tme a bluish appearance, highly grateful to the eye. ^ 

No. 5. Finally, one of the most remarkable' varieties of the. 
<nrfaiealBr granite discovered by M. Blathieu, and at the same 
time the most dearly distinct as a variety, is that which, on 
nearly a Mack and equal ground, resulting from a uniform 
fluxture of vrhite felspar and Made hornblende in partides, is 
distinguished by its globules having in general the first cirde 
white. Ab black is the dominant colour in this singular 
Yariety of orbicular granite, the white ciides which succeed^, 
and are idtemated with black, participate of this tint, and 
are, as it were, veikd with black : they are, however, very 
distinct, owing to their contrasting with the other circles, 
which are of the deepest black. This variety, which takes a 
polish equally beautiful with the other specimens, and is 
equally luurd, is found in tolerably large masses. It is ad- 
mirably adapted for urns, and other vases of a grave aspect. 

Such are the principal varieties of the orbicuknr granite, 
for the discovery of which we are indebted to M. Mathieu* 
I harre thought right to give these details at length, the fas- 
ter to ddineate a rock of which nature has been so little pro* 
digaL I reserve all the focts, that I may resume them when, 
if I am aUe, 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 fW>m which the block of 
TaroDo was torn, an exact datum will be afforded of a veiy 
singular geological feust 



GLOBULAR PORPHYRY OF CORSICA j 

Ls ditpodtiimin large veini. 
(t was reserved for M. Matbif^u to find on its natal spot* 



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(It A»99MBt%. 

mat oilf tteovUottlir gmt&m, but ibogkilMar F"V^» 
mo of Um flMwt bcattUAil stoiiM knovmto aaiiieniiQgiMB. 

I haA hetagt hmtd flrauk BL Diqieynl:, cfataf «igiaBerdbi 
poHM «f ckatmitt Ifi ConlOA, a very good natanliit, tbst M. 
Mathieu, a captain of artillery, had disooiviered laige xnassei 
of gisbldar iMTpbyiry on thalr lite. AL Dupeyiat vat so 
good o«ieti as to ^ir« ma a handsoina vpeehaea of tfas^toaa 
ft«m M. Matliieu{ Imt I was yet wtthout the neeantfy op 
ftnnatlon nMiMctiAg tba tpOt where it was tiuiid» to be abb 
to apiak of it with eertaiaty, «ifhaa IL MathieQ, imder csden 
to join thg aroiy in HoUaod^ caaoe to Plim, when I had the 
Iiiea»ura of seeli^ him, and receiving soDie veiy in rtru L ii fa 
detaikj aoeoai|ianied by pkna and drawings and a aeris of 
very fine spedmens of all the varieties of globular pofphyiy, 
apith whtdi be waA so obli^ng ai to enrich my ooOectioii- 

My book wag wholly printed, but the pab/ioetian wat do* 
layed by the eogravicigs not being jot catiiely oompkted} 
this delay allovred of my inserting the pttsent aoooiuitt as 
wen ae that I have previoinly given of oibicolar gnnita; the 
learned among naturalists vrili be the better pleased with BK 
for producing it, as the basis of the acooont is dsrived lirom 
M. Mathiea himMtf. 

It is fit however that I should observe^ before I ppooeed 
Anther, that a specimen of globular porplqny, neaiiy twenty 
years back, vras added to thecoUeetion of the beantiiiii cabi- 
net of natural history in the Ha^l de Momude at F^iric* 
Ibrmed by M* Sage* founder of the flnt School of Mines, a 
ticket to which states that it came from Cfmlma^ m Oonkaj 
but whether this single specimen whoUf escaped the nodoe 
of miDeralogists ; whether it was r^rded o woly em a snt 
of solid geod, formed acddentally in the composition which 
serves it as a gang, this species of stone was no looger 
spoken of, and no specimeiks of it were found in other cs- 
binets. 

In the n^onth of January, 1906, M. Rampaase, a veterso 
officer of Corsican light in&ntry, &voured me with informs- 
tion from Bastia that^ in a mineralogical excursion Into tiie 



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iMunUhto of gnmhe in aeatch oTcfrbliMlir gnsu/te. In whkii 
aeaidi ht wae uiiBttdo^nM, h^ h&d in some nMtfure been in^ 
drataified by tht dac6ter]r, on the flanic of a mountain co^ 
veredl with wood, between Monte PerttMito and the ynSkj 
Mndi leads to Santa Maria la Stella, of '< a block of stone^ 
Ibtur ftet and a half in length by tht>eein breadth, which was 
eutak in the eai*th^ and displayed on one of its sides globular 
bodies remarkable for their disposition and colour.*** M. 
Rampasse added, tiiat he was unable to sunder more than 
«bout eighty pounds weight from the stone, and that he con«> 
aidered it a proper appendage to the orbicular granite. Some 
time a^er M« Rampasse came to Paris, and the specimens of 
^obuliir porphyry which he brought with him stron^y ex* 
oited the attenticm oi naturalists 

II watf not tiien generally known^ and I myself was at that 
time ignorant^ that M. Mathieu had discovered, twehe month! 
before, orbicular porphyry on its natiire lite, not only in 
large masses* but in a Idnd of veins, very thick and of oonsi^^ 
dbrable extent, and that he had already sent to I^uris two 
metnoirs on the occasion, aoocMnpanied by plans and charts^ 
the one intended for piresentation to the Institute of France^ 
the other addrcesed to M* Viakrt^teint-Morys, who rssides 
oB Me of luB estates at HoiidamviUe, in the neighbourhood' 
ofClermenti in the department of the Oise ( this latter was 
abo accompanied by several specimens of the stoae» which^ 
With the memdr> were contained in a case that had not yet 
been opened, and which M. de Saint Morys was requested bf 
M. Mathieui on his passing through Paris, to deliver into my 
hands. Frbm this memoir I propose to designate the site oi 
the gkrt^ukr porphyry found by M. Mathieu, in a different 
apOt from that in which M> Ram p asse discov er ed his insulated 
block partly buried in the earth. 

'* The territory on whidi the globular porphyry is found,*' 
saye M. Mathieu» in a memoir sent to M. Viidart^Seiint-Mory^, 

• Sm t)ie lettef of M. lUmtittte, intettdi Tome vB, pa^ 470, of ike 
Atiho^ du Muit^m ^BUhire NatMntti. 



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^30 APPBKms. 

And which- 1 have at this time before me, ^ is bounded cm the 
aouth by the BuMsagia, and on the north by the Marzoliao; it 
oompnaes the (fisdrictof Ozani, and that of Girolala, which 
collectively have an extent cS about eig^ht leagnes and a half 
square. The aspect of the country iB extremely nigged and 
wild, especially in the district of Girolatar: nothing is seen 
but steep and arid mountains, the most elevated of which 
foftu a line from east to west ; these are accompanied by other 
small chains less lofty, resembling teats, which become gra- 
dually of less height as they advance in amphitheatrical dis- 
position to the sea, when they tenninate in almost inaccessible 
olifi. The whole of this mountainous district is composed of 
porphyrous rocks of di&rent species, varying from each other 
in colour, in the disposition of their constituent parts> in 
degree of hardness^ and the different state of oxydation of 
the iron which generally predominates in them. 

'' These rocksT are furrowed by long and large vems, some 
of them more than sixteen feet in thickness, and of consider- 
able extent, ' As these consist of a porphyry of greater hsrd- 
ness than that which forms their bed, and which has under- 
gone a change from time, they resemble large walls raised by 
the hand of man. Many of these veins have gbbuks in 
them,' varying in Mze and intensity of colour; and as these 
kinds of walls are sometimes very wide apart, they present 
distinctions and a great variety in their form, and the dispo- 
sition and shade of the colour of their globules. The vein of 
the village Curzo is greyish; in this the globules are verj 
huge and of a somewhat rosy colour; while at GiroUua 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 laiger than peas. The largest glo* 
bules are found on two peaks of a sugar-loaf form : these 
show themselves distinctly, and contrast perfectly with the 
ground, of the porphyry; they -are three inches in diameter, 
and most commonly four. 

" At I<a Bocca Vignola the whole sur&ce of the soil is co- 
vered with small balls in a state of decomposition; at Ia 



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ktmmx. 621 

hocca Gtdcfia Che ftkpar, har^ and of a deeper coldur tkaA 
any Mrhere else, contains globules of a paler hue ; there also 
are Ibund most beautiful geods of a substance much more 
indurated, which seem as if agatised, and are of a reddish 
brown colour j at Fomaci the same kind of geods, but of a 
iriolet tint: these last are very bulky, some of them being 
more than a fi)ot and a half in diameter. 

'* At Elba, on the sea-shore, globules are found detached 
from their matrices, forming a sort of insulated balls. It 
appears that the action of the waves has been suffidently 
forcible to beat down, break, and wear away, blocks of the 
porphyry $ but that the gk>bules being much more hard, have 
more strongly resisted degradation, and been cast on shore. 

" To conclude : this vast extent is entirely composed of 
pori^yrous rocks, intersected by numerous veins in the form 
of walls^ in which the globular system is every where rnani* 
fested i and this wide field for observation well deserves the 
attention of skilful mineralogists, who could not £adl of • 

DP^kjyig numerous discoveries.'* 

It now remains I should give a detail of the different 
specimens of orbicular porphyry, presented to me by M. 
Mathieu. 

No. 1. Porphyry of an Isabella colour, with a very light 
ahade of the rose, the globules spherical, very small and ra- 
diant, some of them encircled 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 folspar, 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 feom the oxydation of the iron it contains^ as from other 
causes. The laigest globules of this porphyry are but four 
Ikies in diameter, the smallest in general three. When thrs 
Stone 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. ^ 



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§11 4rfn»» 

TMnnrifltyirf fptytwr wJ^mtM ji i W Iii i m i i iB tht 
detail giveoofit, oa ajpapnnt <if ite u nnw if ny uiig y*| 
the porpbyry with Iwipp f lobotei wkMi we m^ aham H 
mantion i or, room proparty apeakiffg^ tkia ia Um md^ idcK 
iiiBiiditofwtkicbtbalatlar k umi aaiNEioplr fiamrf m tht 
•hfqM of thick walls wbidi v«M»bia vmm, ami wliah ekom 
themselves in th» mannar only OH aiOiMUlt <if thdr hara^ 
MMQiad a flvaater rosiMaiiipa to daconiparftiaai thwi tha sar* 
voondingfqck with iipaU globules. Tbiamek^wmiabaMl* 
iiig in fclspoTj and of mm homsgpmfm tMtvre, i^ lib d 
felspar, sulgect to a spapias pf qpontanwii if t a mntrntHmt^ 
aspaciidiy if irouj 90 piwa to oxsKbliDaw bo ixMid in it. 
either uoitfid or in oDmbinatiant in tPO giaae n nwiKrti o n . 
The w«Ib of flobuiar poq%ry have «fen iwva aeadiljr be- 
OMPf exposed^ when tb^ hava ^hanoad i» baamonmM by 
rocks of.a grsenisb gimulatad porphyiy, of n mon^ fanrfir 
nature, and similar to thoae fcund at OhaoMnf in tka 
^ Sstoralle otoantain ; and in ganw nl inioM^tovBiUicayiayiiig 

porphyry. 

No. 2. Spherical globules^ two inches in 4iafl9»tfir, tlis 
smallest being of two inches wanting three lines, lyillg fal 
their gang, to which tliey closely adhere. 

l%ia gaz« ia compact feiipar, apeoklad witfcM ocfary jKri of 
different shadei^ with anwU ipotn of nblaafcisb kpown^ i«d 
pan be conridered, as wall from its poaitinn m fiam jia apf»< 
oial xi)od« of formation^ aa no other than a 
not a ja»potd« for ita parte are foibla under tlio | 
Observing tha anall red appts threugli n mifwaaap^ opia 
sees distinctly that tbgy are fonnad on^r by irayaiiial iialnl 
Usatione of » gbbiilar figure. The grannd^ of n UacUib 
brown« on which tbeee dinunutiva gk)biiiaei in an kinniiiii.l 
etate and of a reddish oolour^ appear, bee tUi tint Ivoan tki 
bron, on its oxydation, fwenwiflg a blaokiab aajovr, 
bx the globuks the ovyd of tha iron is mdj kvl 
there be a somewhat greater piopoptiM of quavtay fwCldia 
in the smaU blackish spots thw in tfeo«aaAia)iaaeiftd»Jlii 



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m iMi tlMt tteipola aM the liMsnttilP of a U«ckki 
harder m a eortiCii dcgne than tkote whkh are red; tbie i^ 
moft evident alUr the itoiie has been eubiaitted to a polish^ 
and is axpaaed ta « ft(voiiralde lif^ The Uaek parts afe 
thaa aaoi ta bealishtljr aaiiaat, and to axbibit, notwitbstWMlp 
kigtha whda ftoae recaiveB a bcautlftil pdiAb, a gloarilMe 
iMtfa livdf end eaoca hffilUaat tbaa the rest of it. 

The gldiaks eiicloeed in this poqdQpry are of a flash c^ 
irafyiog in shade, with radB diverging from the eentie to tba 
tfocusiiarenea, traaad by Hnaa of a noee evident coloiir than 
tte vast of the globuk. and rather Uaekish^ these Hnes irra* 
date from a kemd in the centre, of a unifiNrm but more red 
colonr than the rest of the globule. A brood eircular Hnsi 
ahnoat white, or bat feintly tinged with red, sorroiuids eadi 
globule, and determines the drcumference. But, in order to 
obtain all thaM results in the heat manner, on sawing the 
specimens care should be taken to divide each ball as nearly 
as possible in the centre, so that the kernel may ai^>ear : the 
balls thus cut take an exquisite polish, which exhibits in a 
plain manner the eftct of this singular system of globular 
crystdliAtioa. 

No.3. A peifiectfyspharioai ball> aeddentally separated fhmi 
tlia rock) it is three indies and six lines in diameter; a 
diele five lines broad, and unilbrm in its breadth, surrounds 
Hm eaOeiiar of the faaO, which is composed of a kindofhaid 
Mspay> amdogous to that of the matrix, but of which die 
points, of a reddish colour, are very smalL All these present 
iMparieet crystalliBaHons in small compact diveigent n^e. 

A second oinde, two lines and a hidf in breadth, of com* 
pact M^ar of a lawn-cokmred white, is cnekssed within 
the aifeemal drde, and the rest of the ball is oidy an assem* 
biaga of crystab of compact febpar of a somewhat deeper 
tiat, which dinot to a eommon centre: I had this sapamtcd 
taJl cut into two equal parts. 

No. 4L In a beautiful specimen composed of three large 



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/GooqIc 



6S4 Af rs«uii^. 

globules, very sound, iind perfect in their gipgnt, a singv^ar 
accident is seen to have taken place, the disoovery of which 
is owing to mere chance. Having caused this specimen to be 
cut, in order to be enabled to place it in my dhnawere^ it was 
divided into two equal parts; and the operation expoeed m 
globule two inches and three lines in diameter, a piece oC 
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 peroeptlbl& 
This section of the globule forms a kind of crescent one inch 
seven lines in length, which is out of its place as if repulsed 
from the circle, but in such manner that one might bakcjL 
it would assume its ancient disposition; notwithstandiog; 
which, I must repeat, it b difficult to distinguish the points 
of connexion. 

This specimen, before it was cut, was presented to me by 
M. Rampasse. 

No. 5. An elongated oval globule, of groat reguknty ia 
its colours} in breadth one inch nine liDes, in length tour 
inches two lines : it is to b^ pri^^um^d this elongated form is 
owing to the union of several globules at the period of their 
crystaililsationy which thus became confounded in one oval ; 
a line of red felspar fills the whole length of the git^to^ 
diameter, and the crystals diverge from thb point, whicZi 
serves as their common centre, thb apedmen, h%hly re- 
markable on account of its shnpe, h^ a klud of r^^ularity in 
all its parts. 

To conclude, the large blocks of a atone so singular and m^ 
hard as this, were they worked far the purpose of introducing 
them to the arts, whether in mukim^ of columns^ tables, or 
socles, would present pieces equally rt^tn^irkable for the na- 
ture of the stone itself, as for variety, size, the coknir* 
and form of the globules^ which render it so much an ol^iect 
of curiosity. 



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M9nmmxs 625 



No. Vn, Reinegg$ on the Mineralogy of the Archu 
pelago. 

[Scelta di opuscoli inteFessanti. Milan 1777, 8^0. vol. zxxu. *] 

The mountains of Istria are connected with those of Car- 
niola and Stiria, of a moderate height, hut rather precipitous* 
They entirely consist of limestone, with a prodigious quan- 
tity of nummulites. Statues have been formed of it, in which 
the 8helIfl*produce the effect of marks of the small-pox. The 
strata are strangely varied, sometimes horizontal, sometimes 
vertical. They are mostly clothed with olives and vines. 

Further on is formed a siliceous sandstone, which after- 
wards changes for white limestone, which continues to the 
neighbourhood of Ragusa. 

The mountains of Dalmatia are of the same kind, being 
sxiostly composed of a compact limestone, capable of polish. 

Near Cattaro appears a kind of gneiss among the fissures 
of the limestone. Towards Scutari the mountains are gra- 
nite. The P&sha presented to him some medals of iron^ 
^hich he says may be as ancient as the time of Lycurgus f. 

The chain of mountains of Epirus continues into AAsdiaj 
where the summits are very high. 

Most of the isles, as Cefalonia for example, have a high 
mountain in the middle, which gradually lowers towards the 
sea. Mylo presents warm sulphureous waters. Some of the 
hills of this isle are calcareous, others of a brown marly clay. 
There is also found a fine talcaceous earth. The subterranean 
fires, mentioned by Toumefort, no longer exist ; but there 
are vestiges of volcanoes towards the north, where the hills 
are granitic, with basalt and vitrifications. There is a hill 

* Thif paper being ihort, and little known. It wai thongbt proper to pre> 
terte it here. 

f Thia ia tmly aingnlar, aa auch ncdala hafe alwaya Ibimed a datidefatiiin 
M cabioeta, and we can haitUy iuapect a mincralogiat of miatakit^ the SMtal. 

VOL. II, 2 S 



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G26 Amvo»* 

of a kind of pamice, which is so hard as to fonn miDsioncSy 
but of a very bad sort, and the chief cause of tlie bad bread 
which is eat in all the Archipelago. 

Of ParoB, though celebrated for its marble, the high hlDs 
are of granite ; but day-slate also appears in the vlciiiitj of 
the marble. 

Miconi is chiefly of granite andbaaalt There are cunents 
of volcanic glass, from one to fourteen inches in breadth, in 
the granite, which is also interspened with basalt. Towards 
the south a crater appears full of volcanic glass, basalt, and 
many kinds of stone which have evidently undergone the 
actionoffire. Towards the port is decayed granite, and ther^ 
IS no mark of limestone* 

Scio is one of the most beautiful of the Greek isles, and 
the people the most amiable and intelligent. In the toriento 
are found many kinds of granite, ja^wr, s^pate, cameiiaD, 
quartz, and oakareoos qpar. There are also ancient nnnes 
of silver i and some volcanic appearances. Scio is &moiia 
for the culture of mastic; and the popularion is eomputed at 
sixty thousand. 

The hilb of Mitilene aie sometimes wholly compoeed of 
pure and white pumice, while others are granitic, and the 
great(srpart<:ak2aieous. The mountain called Kara is wholly 
composed of fragments of basaitf quartz, and a black stom 
which aeeflss a trap of the Qermans united by a cement wUcfa 
isbalfcakined. 

Near Sosyiiaa the highest mountMns are of granite. One 
hiU appears split in two halves^ of which one, wlodi iasepn^ 
rated to the distance of about 300 paces* is all broken in 
pieces* The iotemal fissures <^ the mountain Bte filled with 
awhilelimeBtone, like the maihle of Faroa, which peaatntes 
the gntayte in every du«ction, in vems ftom one inch to 1 W 
paces in breadth. Here, and at PtoM, the marble is sepa- 
rated from the granite by a layer of green mica-skte. The 
, calcareous hills about Smyrna may often be distinguished 

from the granitic by being cavemoiia, and yielding a Ik^Iow 
sound under the flset Bonmafattt, the idrest part of the 



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territory of Snqrrna^ presents many ancient colunlind of h» 
salt and granite ; but in the nio$qu€9s tbe TTurks, froA supers 
•dtion^ colour them green or ted. About five miles* fi^om 
Smyrna is a place called Nemphis^ where there are mines of 
lead which yield silrer, the hills being travened by reins of 
gneiss. 



No. VIIL Mcount of same Roch in the soiuth ef 
Hindostan f . 

*' In ascen^Bng tbe GhatSj I had an excellent opportunity of 
observing the strati^ where tbe rock had been cut away ta 
fcrm the road. The grand component part of these moun* 
tains is a granite^ consisting of white ielspar and quartz^ with 
dark green mkia in a small proportion to the other two in* 
gredients. The particles are angular, and of moderate size. 
It seems to come neir to the granite^ of the Italians (Wal- 
ler. BAin. iL p. 493)> luad is an excellent material fbr buUdingj 
as it is readily cleft by wedges, and is at the same time strong 
and durable. Intermixed with this is another stone^ in a 
state of decay, consisting 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 beinjg supposed to have been entirely decom- 
posed, and the felspar to be in the act of decomposition, and 
to have assumed aft arid powdery appearaiice, while the glassy 
quartz retains its natural consistence. Tbat the strata in 
question are in a state of decay, from the numerous fissures 
in them, I have no doubt j but there are other strata of simi- 
lar component parts common all over the lower Carnatic, 
especially at Mahahalipura (the seven Pagodas), which are in 
1^ most perfect state of preservation, without the smallest 

* German miles? 

t I)|MiB«Gli)nnn'tTrirtbyafolt.4t^ 

Ss2 



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628 APPENDIX* 

mark of decay, and fit for fonmng the most durable bund* 
ings. Mr. Fichtel> who has been so kind as to look over my 
specimens, and to assist me with his opinion concerning their 
nature, thinks that the stone of Mahabalipura ccmsists of a 
mixture of arid and of fak quartz j and although he calls the 
stone of the Ghati granite, I have no doubt of its component 
parts being the same with those of the Mahabalipura stone. 

" Both these rocks appear to be stratified ; but the strata 
, are wonderfully broken and confused. In some places they 

are almost horizontal, in others they are vertical, vrith 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 5 while 
In other masses of eight or ten feet high, and many long, I 
could perceive no division. 

'' Immersed in both kinds I observed many nodules, at 
large as the head, which were composed of a decaying sub* 
stance containing much green mica. In other places there 
are large veins, and beds, containing smaH rhomboidal masses, 
of what Mr. Fkhtel takes to be a composition of a small pro- 
portion of quarts with much iron.*' * 

Oftheh^UtmearCaoenf. 

*' The strata on these hills are various. I saw red granitic, 
porphyry, and took specimens of a fine-grained gneiss, con- 
sisting of pale red felspar> white quartz, and bbck mic^ 
The most common voflk, however, is the hornblende slate 
with <piartz, which I have before mentioned. When exposed 
to the air in laige high masses, so as to prevent the water 
from lodgfaag on it, the pieoes decay into fragments of a 
ihomboidal form; but when exposed to the air on a level 
with the ground, so as to be penetitfted by the rain water, it 
divides into thin lamine, Uke common acfaistus.*'t 

• YglLp.ir. fVAtp.**. 



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Appiiffoix. 629 

^* The stones that are employed in building the t^nples at 
Magadi are : 

'' 1. The granitic porphyry, or the granite which contains 
lai^ masses of red felspar in a small-grained mixture of grey 
Quartz and black mlca> which I described at Rdma-giri, Near 
Saoanddurga there is an excellent guarry of this stone. 

"2, A granite, consisting chiefly of black mica and red 
felspar. This may be procured of a Tery large size. 

*' 3. The common grey granite of the country. 

'^ I met also with the two following stones : ^ 

*' 1. A granite with large grains, black and white. This 
may be procured of great size. 

" S. A most ornamental ag^;regated rock. The basis is 
green» of what nature I am uncertain -, perhaps it may be a 
hornstone. It contains 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 fuU of rents; but by 
digging deep, it is said large masses may be procured. It 
seems to differ fix>m the fine green stone which was found in 
the palace at Seringapatam, only by containing felspar.*' * 

Quarry of black itone* 

*' This quarry is situated about half a mile east tom the 
TiBagef, and rises in a small ridge about half a mile long, 
100 yards wide, and from SO to 50 feet in perpendicular 
height. Hiis ridge runs nearly north and south, in the oom« 
mon cBrection of the strata of the country, and is surrounded 
on all sides by the common grey granite, which, as usual, ia 
penetrated in all ^brections by veins of quartz and felspar; 
but neither of these enter the quarry. 

'' This stone is called CaricuUu, or black stone, by the na- 
tives, who give the same appellation to the quartz impreg^ 
Dated with iron, and to the brown hematitesi and in feet 

•VoLLp.ia8. fCiMnillj. 



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630 AFPXITDnL 

tb^ all run very much inte one another, ftiid £iler chkflf ia 
the various proportions of the same component parts ; bat 
have a' certain general similitude easily defined, and are fomid 
In sinular masses and strata. The black-stone of this pinoe 
is an amorphous hornblende, containing minute but distinct 
rhomboidal lamellar concretions of basaltin*. I imagine 
that it b the same stone with that which by the ancients was 
called basaltes, Bnd which was by them sometimes formed 
into images, as it is now by the idolaters of India. 

" The surface of the ridge is covered with huge irregular 
masses, where they have been long exposed to the air in the 
natural process of decay, lose their angles first. When these 
masses have thus become rounded, they decay in concentric 
lamellse ; but where the rock itself b exposed to the air, it 
separates into plates of various thicknesses, nearly vertical, 
and running north and south. In the sound stone there ts 
i!iot the smallest appearance of a slaty texture, and it spliC^ 
with wedges in all directions, llie north txxA jof the rid^ is 
the lowest, and has on its surface the largest masses. It is 
there only that the natives have wrought it; they bate 
always contented themselves with splitting detadied blocks, 
and have never ventured on the solid rock, where much finer 
pieces might be procured than has ever yet been obtained. 
The Baswa, or bull, at Turiva-Cary, b the finest piece that I 
have seen."t 

''Immediately north from the village b a quany of Balls- 
pum, or potstone, which b used by the natives for miking 
small vesseb; and b so soft, that pencils are formed of it to 
#rite upon books, which are made with eloth blackened and 
stiffened with gum. Both the books and |he neatness of the 
writing are very inferior to the similar ones of the people of 
4va, who, in fact, are much fhrtber advanced in the arts 
than the Wndui of thb country. Thb potstone separates 
Into br^e amorphous masses, each covered with a crust in m 

• OfKirwtn; oiystallised nderitc. 
t Vol.i).p.ei. 



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Afrxiipii;^ 631 

decopng state ; and some of them are entirely penetrated 
with long slender needles of schorlacebus actinote.'* * 

The hill on whieh Mail-Cotay stands consists of a kind of 
gneiss, but the description is very confused : also a granitel 
of black hornblende slate, mixed with white quartz in such 
a manner that when broken longitudinally the quartz forms 
veins, when transversely spots, f 

^* The strata on the Chats are nnieh covered with the 
«oil^ so that it is in a few plaoes only that they are to 
be seen. Having no ecMmpess, I could not ascertain their 
course ; but fo as I could judge from the sun in a country ^ 
so hilly, they appeared to run north and souths with a dip to 
the east of about 30 d^rees. . Wherever it appears on thm 
sor&ce, the rock, although extremefy hard or tough, is in a 
state of decay ; and owing to this decay, its stratified nature 
is very evident. The plates^ indeed, of which the strata con- 
sist^ are in general under a foot in thickness^ and ar^ sub- 
divided into rhomboidal fragments by fissures which have a 
smooth surface. It is properly an i^gregate stone, composed 
of quartc impregnated with hornblende. Fhmi this last It 
aequires its great toughness. In decay, the hornblende hi 
some plates seems to waste foster tham ii^others, and thus 
leaves the stone divided into zoneM, which are alternately 
porous and white. I am inclined to think that all moun- 
taSms of a hornblende nature are less nigged than those of 
granite, owing to their being more easUy decomposed by the 
action of the air. This rock contains many small ciystallised 
particles^ apparently of iron.'* X 

• Vol. iL p. 69. t Vol ii. p. 7S. 

t Vol. m. p. 301. 



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632 APPENDIX. 

No. IX. Letter of M. Daubuissorij on Ms intended 
ireaiise of Geognosy ^ to the author. 

*' Paris, le 20 Genniml. an 13. 

'' M0N8IQUB> 

'' Je suis bien facbe de ne pas in*^tre trouve cbex mot 
loTsque V0U8 y etez venu : j'aurois voulu avoir rhonneur de 
Tous saluer avant voire depart. Mon traite de G^ognoaie, 
d'apres les principes de M. Werner, avance, mais lentemen^ 
vu ie peu de terns que j*ai a ma disposition pour y travailier. 
Je viens de rediger d^finitiVement deux longs chapitres presqo* 
enti^rement de Geqgraphie physique, et qui oertaininent vouf 
interesseront beaucoup : Fun traite des in^alit^ de la sur* 
£m» du globe, potamment des montagnes, on y traite aises 
en detail des diverses parties d*une chaine de monti^nes, et 
des observations i hire sur chacune d*elJes : Tautre a princi* 
palement pour objet Taction Erosive des eaux et de Vat* 
nospbere, sur la surface du globe, et Von y examine jusqa*4 
quel point cette action a pu, non produire, mais fagomur kt 
ii^egalitis de cette sur&ce. Je suis dans ce moment ocoupi 
du cbapitre peut-^tre le plus interessant; &luiqui tndtedela 
structure, de la stratification, de la superposition, des roehes : 
ici rien n'est th^orique, ce sont des fisuts, ce sont ks prindpes 
qui doivent guider Tobservateu'r. Je ne puis dire avec pee* 
cision 4 quelle epoque mon travail sera livpi 4 rimpreasion^ 
n*^tant pas maitre de disposer de mon tema cooformement 
a mes desirs. Lorsqu'il aura paru, je le recommande 4 votie 
indulgence, et serob tr^ fiattft s*il pouroit avoir Tappro* 
bation d*un juge aussi ^clair^ que vous. 

^' Daignez agreer les assurances de ma conaidentkm 
di8tingui> 

"J. F. DAUBUISSON.** 



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N4-1 



fi^.t 



^S 





Fig 4. 




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APPENDIX. 633 

I 

No. X. EoBphnatim of the direction oiid mcUnation 
of reins. 

[See the Plate.] 

The position of metallic veins is ascertained and described 
by three diflferent angles; that of the direction, dip, and 
inclination. ,, 

The angle isf direction, or simply, the direction, is j^aa^* 
tained by obsexVing the point of the compass; or degree of 
the horizon, it tendt towards, bs A B, Fig. 1. ^"' 

The dip is the angle which it makes with the plane of the 
horizon, 93 B A E, Fig. 9. 

The inclination is the angle which one of its sides makei 
with a vertical plane, as a b c. Fig. 3 5 where b c repre- 
sents the transverse section of the vein, and a b that of the 
vertical plane. 

This is iidtlier illustrated by Fig. 4 ^ where A B repre- 
sents the perspective view of a metallic vein. C D is the 
compass placed parallel to the horizon, and £ F is the 
direction of the vein. 

The angle F£ B is the dip, being the angle which the 
Tein makes with the horizontal plane ; and the angle abc 
is the inclination, or the angle which the side of the vein 
makes with the vertical plane a 6. 



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e94 



ArrBvoiSL 



No. XL EjMumpUi of the oppUcaHom nf ihe praent 
tysttm to lAthologjf and MetaUogy. 



LTTHOLOGY. 


M. L 


SIDEROUa. 


II. 


SIUCEOUS. 


III. 


ARGILLACEOUS. 


IV. 


TAIjCOUS. 


V. 


CALCAR|:OUS. 


VL 


BAtlYTIC. 


VII. 


STRONTIANIC. 


VIII. 


ZIRCONIC. 


IX. 


SALINE. 


X. 


COMBUSTIBLE. 



DOMAIN VIL 

STRONTIANIC. 

Mode I. Strontlan, or Car- 
bonate of Strontian. 

Strdcturb I. Masnre. 
Aspect 1. Entire. 

f . Witii baiytes, gal^ 

StroctureIL CiystaOised. 
Varieties^ green, white*. 

Mods II. Celestine^ or Sul- 
phate of Strontian. 
StrccturbI. Fibrous. 
Aiped 1. Maanve. 
2. Laminar. 
VariiHeBf of different colonn. 
Structure II. Foliated, 
m. Radiated. 
IV. Compact' 

• Any verj ilagaUr eolovr woold 
form • Divenity, 



Of this bat is that of Mont- 
martre, whicli however oidy oc- 
curs in geods or nodoka, and 
greatly yielda in beauty to the 
other Stmctnrea. 



DOMAIN VUI. 

ZIRCONIC 

Thk iDRj be divided into 
two Modes, as there seems 
to be more silez in the ja- 
eint than in the zireon ; and 
at aoj iBiB the aiode of 
oombiiiat]oaiftdiflneat,eiae 
thejr could not be ^Mn* 
guiflhed. 

Mom I. Zkoom* 

STKucmivL GMMkr. 

n. la vanoRB em- 
talline forms, which most be oe- 
acHfoed. 

ModeII. Jacint, by the Per- 
aaana called Yiacnt 

Structurb I. In roond giaina. 

II. In vaiiaoa ciya- 
talline forms, which form aspects, 
while the coloan form varieties. 



METALLOGY. 

DOM. L GOLD. 

n. PIATENA. 

in. SILVER. 

IV. COPPER. 



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AFFBWOIX. 



«S5 



DOM.V. 


IRON. 


VI. 


TIN. 


VII. 


LEAD. 


vin. 


MERCURY. 


IX. 


ZINC. 


X. 


ANTIMONY. 


XI. 


ARSENIC. 


XII. 


BISMUTH. 


XIII. 


COBALT. 


XIV. 


NICKEL. 


XV. 


MANGANESE. 


XVI. 


MOLYBDENA. 


XVII. 


TITAN •. 


XVIII. 


CHROME. 


XIX. 


SCHEELE. 


XX. 


URANIUM, &C.&C. 



Dr. Thomaon observes that all 
nietab are found m llie (bllowing 
states: 1. Metallic, eitlier alone 
ir oombinecL 3. Combined with 
sulphur. 3. Oxyds, that is, united 
withoxysen. 4 Combined with 
acids, '^ch order therefore, as 
he adds, may be divided into the 
four foQowii^ Ctenera. 

1. Alloys. 3, Oxyds. 

2. Sulphurets. 4. Saits. 

But Haiiy has, onthecontraiy, 
considered each metal as a gle- 
ans; and Werner, an excellent 
judge of nietallofi^ in particular, 
considers each metal as a /ifenns, 
and the vanoos combinations as 
species. 

But as Mode chiefly implies 
ftke mode of chemical combina- 
tion, it is evident that these pre- 
tended aeneraand species, wnich 
are wholly vaffue as being derived 
niein an anaJesy merely imas;!- 
nary between inert and animated 
nature, are most properly and 
pecnliarW Modes. The Aspects 
are eqaaHy applicable as in Petra- 
logyand Lithology. The Struc- 
ture is also applicable to the com- 
poMtioB «i geveral; as in tintO' 



f Aaother ntme tntaU be prefer- 
able. Id the Greek Mtan is /ime. 



Hon wrftsmm it k elasskUly ap- 
plied to very small objects*. 



METALLOGY. 

DOMAIN I. 

GOLD. 

NOMSL ALLOr$. 
MoDB I. Pure, or rather en- 
tire, for it ^ways contains 
silver or copper. 

StructurbI. Massive. 

DiDer$Uim, ll m focks; 2. in 
pepitot, or detached masses found 
m clay or sand, &c. 

Strocturb II. Dissaminated 
in rocks, sands, &c. 

Structure III. Crystallised. 

An)ect 1. Ip cubes, or other 
regular forms. 

Atpect 2. Dendritic, like 
braachesi leaves, Sec 

Structure IV. Earthy, of ^ 
brownish red, like spanisb 
snuC 

Mods II. Electrum, pr 
greatly alloyed with silver. 

StrvctvrbI. Coflipaet 
Dendritic. 

Mode III. Alloyed with aa- 
timony. 

Mode IV. Alloyed with tka 

Sylvanite of Kirwan, so call- 
ed from Transylvania, where 
it is found; the Tellurium 
of Klaproth : but Kirwan s 
appellation is received by 
neroer* 

• Sre Liea. p. U (*s slreeily naoted). 
where be sejs ihe e^ural knowledge 
of fttooee ansps from their etmctttref 
tbe cbeMlQiU firem eMlytii. 



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€36 



APPENDIX, 



Stkuctdrb L ProblemiUc 
Gold. 

Structure IL Ontphic Geld, 

Hiere are many 'other alloys. 
The Snlphorets of cold are very 
donbtfhf, as itmaylie aeparatea 
by mechanical means. 

There are no Oxyds nor Salts. 



DOMAIN V. 

IRON. 

NOME L ALLOYS. 

ModbL Alloyed withNickel. 

II. AUoved with lead, 
ice. 

NOMMn. SULPHURET8. 

Mode III. Pyrites. 

Strcctdre I. Massive. 
AgpectU CommoD. 
t. Hepatic. 
Structure II. Crystallised. 

Mods IV. Magnetic Pyrites. 

NOME in. OXYDS. 

Mode V. Magnetic Iron- 

stone. 

8T|iuoturbI. Compact. 

II. Lammar. 

UI. Crystallised. * 

IV. Iron Sand. 

Mode VI. Specular Iron Ore. 

Structure!. Massive. 

n. Crystallised. 

m. Micaceous Iron 
Ore. ' 

Mode VII. Red Iron-stone. 

STRUcnTRsI. Scaly. 

n. RedOdire. 
ni. Compact 



Structure IV. Red HeoM- 
tites. 

Mode VIII. Brown Iron« 
stone. 

Structure I. Scaly. 

IL Ochivoeoas. 
in. Compact. 
IV. BrownHema- 

tites. 

Mode IX. Spathose. 

Structure I. Amorplww. " 
II. Crystallised. 

Mode X. Black Iron Ore. 

Structure I. Compact. 

n. Black Uefli». 
tite. 

Mode XL Clay Ore. 

Structure I. Rnddk, or Rod 
CbOk. 

Structure n. Columnar. 

m. Lenticolar. 

IV. JasperOre. 

For common Clay Iron-atone, 
see Petralogy. 

Structure V. Eagle Stooe. 

VI, 



Mode XII. Bog Inm Ore. 

Atped 1. Morns Ore. 

2. Swamp Ore. 

3. Meadow Ore. 

NOME IT. SALTS. 

Mode XIII. Carbonate of 

Iron. 

Mode XIV. Phosphate of 
Iron. 

Structure L Compact. 
n. Native] 




m. With 



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APPEHDIX. 



6S7 



MoDB XV. Arseniate of 
Iron. 

$i;rdcturb I. CiTitallued. 
II. With Copper. 

MooE XVI. Green Iron 
Earth. 

Aapeei 1. Friable. 
2. Coherent. 

Thit may be compared with 
the Petralogy, in ref^d to tlie 
Stractures and Aspects. The 
xenera of Thomson have not 
Deen admitted by other writers, 
who arrange all the species in 
a accession, without diTidiiig them 
into i^enera. Bot as these krge 
divisions of lliomson seem very 
uaefhl, they might be retamed 
under the name of Nomes, or 
•ubsidiary districts. 

In litbology Dr. Thomson not 
havinff admitted Orders or Ge- 
nera, imt only FYmulies and Spe- 
cies, no confusion could an^; 
and the Modes belong to the 
soixtures of the same suhetonce. 
as Strontlan is one Mode, ana 
Celestine is another; that is, the 
Species of Werner become 
Modes, while hia Subspecies be- 
come Structures. 

In like manner if we take Iron 
the first Species, Native Iron is a 
Mode, or special diemical com- 
bmation. The second Speciea, 
Iron Pyrites, is another Mode 
with four Stmctores, Compact 
Radiated, CeUdar. and dapiU 
lary ; the Hepatic being an As- 
pect The fmirth Speaes, Mag- 
netic Iron-stone, is abo a chemi- 
cal Mode of mat importance; 
whereas m foOowmg Dr. Thom- 
son's arrangement it is merriy a 
Stmctorey nrhile there is not only 



nothing particular in its exterior 
Structure, but its Aspects, the 
Compact, Lammar, and Crystal- 
Used, are real Structures. The 
fifth Species is Specular Iron 
Ore, which becoming a Stractnrt 
instead of a Mode, the terms 
Massive and Crystulised, which 
belons to Structure, become 
mere Diversities. In the others, 
Aroorphoos, Crystallised, Com- 
pact,Colnmnar, Pisiform, Earthy, 
become Aspects instead of Struc- 
tures. 

It is therefore necessary m the 
Metals, as in the Earths, that 
each new Speciea or different 
combination, for example, with 
Carbon, Anenic, he, or with dif- 
ferent modificatioqs of various 
Earths, should be called a Mode, 
as in the other provinces that 
word supplies the term Species^ 
and irapues in itself a new mode 
of chemical combination; and in 
this way only can the term Stmc- 
tnre revert to its ori|^i»l destina- 
tion. 

The classical word Nome, de« 
riyed from Egypt the parent 
country of Cheinistry, may be 
found very appropriate, at al- 
ready explained. 

The (Unity and hnportance of 
the Metato ako reqou^ a mnlti- 
pUcation, instead ofa diminufioQ, 
of the hi^er terms in the nome*. 
chitnre. Nor must it be forgot- 
ten that the very nature otthe 
subject^ which the substances 
and their quaUties are of them- 
selves various and varne, would 
render any attempt af mathema- 
tical precision rather pedantic 
than useful or distinct (the quali- 
ties, like tlie substances ttiem- 
selves, often passing into each 
other); and that every system, 
even the Newtoimi^ hai in ano- 



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Digitized by LjOOQ IC 



INDEX. 



AcTiMOTB Roek . . . ii. 13S 

Actinote, Siderite, Mica . 14 
Alabaster, 

Characters of . . . i. 498 

Sites 499 

Jameson's observations 500 
Branf s account of Gyp- 

soos ib. 

MonamentBof ... 501 

Anydrous .... 502 

Observation ... 503 

Alabaster Dec ii. 251 

AIomRock, 

Name of i. 24C 

Ferber's acconnt . • ib. 

Massive S47 

Characters of . ib. 
Alaminoos Slate, 

Characters of • ib. 

Common . • • 248 

Sites of . . ib. 

Glossy .... S49 

Alom earth . • ib. 
Alabastrite, 

Ancient 458 

With Stalactite and Sta- 
lagmite, the Sinter of 

the Gennans ... ib. 

Pliny's account of . 459 

Mociem 461 

OfVortcrra ... 462 

The onyx alabaster ib. 

Varieties and sites of 463 

Fiorito of the Italians 466 

Amyirdalite 89 

Formations of ... 90 

Origin ..... 91 

Withagates ... 92 

With calcareons spar 93 

With open pores . . 95 

.Aannialous ii. 58 

General observations ib. 

Saltsrandcombostiblet 59 

Coal 60 

Pyrites ib. 

How ranked ... 69 

Anthracite ..... i. 552 

Bonf s account of • 553 

Of the Alps ... 554 



Bronsniarf s accoont of i. 55S 

Friable ...'.. 556 

Scaly ib. 

Schistose .... ib. 

Globular .... ib. 

^ Kilkenny coal ... lb. 

Swansea coal ... ib. 

Anthracite ... 561 

Compact ... ib. 

Laminar ... ib. 

Kirwanite .... ib. 

From Kilkenny . 562 

From Swansea . ib. 

Argil, 

How obtained . . • 239 

When combined . • 240 

Homogenoas ... ib* 
Eminent in gemmology 241 

Argillaceous Glatenite 283 

Large-gramed . . 284 

Maussore's description ib. 

Bricia of Scothmd . 290 

Granwack .... 291 

Bergmanite .... ib« 
Snu^grained ... . ib. 
Jameson's distinctions, &c. 29S 

Argillaceous sandstone 294 

Whetstone, 5cc. • . 295 

Gmelin's arrangement 296 

Sanssore's observations ib. 

Aigillaceoos Intrite, 

Extent and importance 281 

With crystals of felspar 2di 

Clay porphyry ... ib. 

With vanous crystals 283 



Barttic Rock . . . • ii. 138 



Baroselenite of Kirwao 
Account of a singular 
rock near Ambierle 
Basalt, 

Characters of . • . 
Formationt .... 

Proper 

Oftheanciedla . . 
Fine, termed Basaltin 
In various places . • 
Distingais&ed from Ba- 



ib. 

lb. 

. ir 
ib. 
ib. 
la 
ib. 
19 



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640 



INDEX. 



saltin 190 

Obserration on • ib. 

Extent of .... Si 

Of Faroe *« 

Of dnbioos origin . . 93 

Amorphous .... ib. 

Sites of. ... ib. 

Ancient oriental . . Sti 

Colnmnar .... 29 

Analysis ... 31 

Observation on . 32 

Basaltin with Earthy Felspar ii. 44 

Gebrite, why railed . ib. 

Saossure's description of 

a diamictonic rock ib. 

Baaaltin, 

Characters of . . . i. 32 

Volcanoes • . . • 38 

OfEtna 41 

Of AuT^rgfne ... 47 

Brochant's statement on 56 

Brongniarf 's idea of . 65 

Amolrohous .... 66 

uniform ... 67 

Minrled ... 68 

Basaltic tola . . 69 

Breda ... ib. 

Colntnnar, 

Uniform ... 70 

Mingled ... 71 

Basaltin ^th Siderite . . ii. 45 

Rbazite, why called . ib. 

Basaltin with Silex . . 46 

Ebensinite. why called ib. 

Basaltin with Wacken 46 

Albertite, why called ib. 

Basaltin with Steatite . 47 

Baconite, wfav called . . ib. 

How dmerent from 

Sanssnrite ... ib. 
With steatite dissemi- 
nated ib. 
WithiPlobnles . ib. 
Basaltin and Basalt, or Ba- 

salton 166 

OfMeisneT .... ib. 
Dauboisson's ac- 
count of • . 167 
Ancient basalt ... ib. 
Not volcanic . . 168 
Different appearances of ib. 
Observation ... ib. 
Basaltin with Porphyry . 169 
Examples of ... 169 
Separation of, how 
marked • . • . ib. 
Basaltin and Wacken . . 170 
Wenier's account • ib. 
Obaervation on . ib. 



Observations on Dao- 

bnisson's opinion . ttt 
Basalton, 

Characters of . . • i. 7t 

Name ib. 

Grunstein .... ib. 

Werner's opinion . . 73 

Compact 74 

Slaty ib. 

Klmkstein not allied to 

* basalts 75 

Bt'rjpirt ..,.-- ^ L 5431 

Bfiryl Rot'k iL 130 

B]tiiininr>Tia R^jckA ^ , . 147 
Bitiimeii» more pro- 
perly b^^loi.ig' to che^ 

iiiLitry * , . . > ib. 
Mostly found in 

i^iTiirts . . ib. 

Wpitt^t'i doubts ib. 

In Scotland - « . ib. 
Fwrther iHuttrationt of^ 

neccsi^fy . . * ib. 
LJjneAtone wJtb 
naptJia or with 

p*-trtil , , , ib« 
Sandiione with mi- 

tif ral ia,r , . 15S 

MiimU or Qspltslt ib. 

BitiimitK)a3i)]aU ib. 

Mar] ... lb. 
limeitoiie witb 

owatclioa . ib. 



CAtriRioos EarlJi^ 

How profluced . . i. 376 
Characters and proper- 
ties of , « . , . ib. 
Limestone produced 

by decomposition of 

niarine Alidli * < STS 

Davy*s expmmetiU on 

lime . , , . . ib. 

Calenreoiis Intrile , . . 519 

Porpljyritie . , , ib. 

Marl>le of Nonette . ib. 

CaWremi^ Glnteaite . 5K> 

Larg-e-ifrained * * ib. 

Siiiiinlar brim of , Ufl 

The N^glefliih a bhcta 59 

AtricaDbricta - . ib. 

Antique , . • • « 504 

Viotet . , . . ^ 519 

Modem lb. 

Bfida of Italy ^ ^ , ib, 

OfSpsiin ... ih^ 

Of France , - 596 

Uvcche d'Alepp* . 9ff 



Digitized by LjOOQ IC 



IWDBX. 



641 



Biieiaof Aix ... i. 538 

OfEysKera . . ib. 

Other briciw ... 5S9 

CommoD of SaoMore ib. 

Small-gnined . . . 5S0 

Sites of ... ib. 

OfFoDtMBebleaii 531 

Jameson'^ obserratioiu 533 

Qindnim .... 534 
Sauniire'ft obeenrations 

on tiie sBndstone of . 

Vkmn 535 

Sandstone of Yaaclnse SST 

Of recent fbimation ib. 

Other sandstones . . 53& 

Sites ib. 

Carbon ...... 540 

How converted into 

earbonic acid . . 541 

In tlie dianiond . . 543 

Gbalk 504 

Chaiacten of . . • ib. 

Sites of ib. 

Jameson's accoont of 505 

Shells in 506 

Indurated .... 50r 

Crude ..... ib. 

Uses of 506 

Eggs ib. 

Stractnres and aspects 

of, Tarions ... 509 

Chiy, Spafhose Iron . . ii. 38 

Clay Rock, 

Characters .... L 869 
The thonstein of Wer- 
ner • ib. 

Dolonden's (teicrlption ib. 
Imprei^ated with iron 

isjaq>er .... 370 
Freqnentljr in coal and 

otnernnnes ... 371 

Sites of ib. 

In Swisseriand . . 273 

. Porcehdn clay ... ib. . 

Boles ...... ib.' 

Almaata ..... 373 

pay Slate, 

Bistinctioit .... 349 
Jameson's account of 290 
Widely extended . . 351 
Distinction to be ob- 
served ..... ib. 
Bjrwatfs account of . 253 
PrimltiTe .... ib. 
Secondanr .... 253 
TowDBon^ Analysis . 254 

Hone a • 255 

Cameos of the Climese t56 

ChuMse nmsiod balls 357 

VOL. II. 



Antique f . 358 

Laterite . . • . . ib. 

Helms'^ account . . 359 

Primitive .... 263 

Chancters of ib. 

Sites ib. 

Secondly .... 266 

Uniform . . . ib. 

Variety . . ib. 

With impressions 267 

Sites ... ib. 

Variety . . ib. 

Black ehalk. ... ib. 

Hone ib. 

Clay Stete Dec il. 349 

Coal i. 563 

Sitea ib. 

Ancient use of . . • ib. 

Soils 566 

Patrin's remaiks . . 567 

Structure .... 569 

Metals, &c. in . . . ' ib. 

Werner's amuwement 570 

Black 571 

Slate ...... ib. 

Cannel 572 

Perflated or Laminar . 573 

Coarse ib. 

Brown ib. 

Earthy ..... 574 

Alum earth .... ibu 

Common brown . . ib. 

Moor • ^75 

Observation ... ib. 

Soils ib. 

Brong^art's accoont of 57^ 

Slips or dykes in . . 577 

Mniesof Enifland . 578 
Seldom of the same qua- 

, lity 579 

Iridescent .... 580 

Common .' . . 561 

Laminar or fblii^d ib. 

Cannel .... . ib. 

Connnnar ... ib. 

Coal Dee. ^ . . ... il 251 
Composite, 

General ebnrrations i 

Gmelin'splan •• . . ib. 

Werner's theorr . . % 
Remarks on Daobnis- 

son'splan .... S 
Saussure's, and otiiers*, 

remarks .... 6 

Pretended granites . ib. 

Coral Rock i. 478 

Origin of ib. 

Sites 474 

CorsUita, 

Description of . . • ii. TV 

2 T 



\ 



Digitized by LjOOQ IC 



648 



MiPBK- 



Smasiire*B remarioi 
Sitet 

Smaragr^ite • • 
Anuymof . 

DicoMPOSBD Rocks . 



Mould 

Limestone of MalU • 

Kirwan'8 account . « 

Ferrucinous rocks 

Banlt 

Wacken 

Decomposition of im- 
portance to the arts 

Roman Pfaaroi . . 

Playfair's observations 
]>eoomppeed Basaltin 

OfOermany . . • 
Amygdialite • . 

Yolpanic nature of . 

Effects of decomposi- 
tion 

Nature of . . • . 

Rapid decomposition 

Rom of Piura or Pienrs 

Diallage 

Diamietonic. 

General observations 

Derivative rocks . . 

Observations . • . 

From the €h*eek . . 



1. 79 
ib. 
80 
81 



209 

no 

ib. 

«17 
til 

fn 

ib. 
ib. 

223 
ib. 
228 
235 
ib. 
236 

«sr 

253 
ib. 
254 

255 

81 

36 

sr 

38 

39 



Fblsitk, 

Characters of ... i. 160 

Palaiopetreof Saussure ib. 

PetroMlex of WaUerios ib. 

OfKirwan .... ib. 

Varieties of • . • . 161 

OfCorsica .... 162 

Petrostlexi compact fel- 
spar 163 

Two kinds of febpar 164 

FeQad ib. 

Forms the base of se- 
veral porphyries . ib. 

Varieties ib. 

Common 165 

Sites of • . • ib. 

- Laminar 166 

KUoffstein of Werner ib. 

Analyses ... ib. 

Klinffstein porphyry 

schistose .... 167 

Patrinite described . ib. 

Klaproth's account . 169 

Klnigstone porphyiy 

ctassed with trap . 171 



Described . . t. 171 
Not considered 

volcanic . • ITS 
External CSianc- 

tere . . . • ib. 

Analysis ... 174 
Soda of Doueis- 

beiK • . • 175 

Earthy 176 

Varieties • . • ib. 
FelsiteandBasaltiB . . iL 175 

Dolomien's accooot of 174 
Febpar, 

Characten ot . . . i. ij7 

Conunon . • . • 138 

Foliated ... ib. 

Gmnnlar ... ib. 

Unctuous • • . ib. 

Minted . . . • • ib. 

Petimtae of the Oiineae 159 

When tensed KaoUii ib. 

OpaliRd termed La- 

Diadorstoae • • . ib. 

Green of Siberia . . ib. 

Felspar, Calcareous Spar iL 16 

Felspar, Fibrous Siderite ib. 

Felspar, Quartz, Ganeto 15 

FeUpar, Quartz, "Mc 16 

Felspar Dec« .... 941 

Cfaang:ed into kaotaa • t4l 

Into day • . ib. 

Ferraeinoos QuartK . « 43 

Zosimite, why called lb. 

Saussoie*sobierTatioaa jb. 



GABMBTRock . . 
Klaproth'sandVi 
tin's analyses . 
Cronstedts opinioBi . 
Unknown except to 

Kir¥^an .... 

Of Scotland. . . . 

Amorphous . « 

With siderite, fi^ 

spar, and mica 

Oeostrome 

Globular Rock, 

SansBure*s accooBt of 
Gneiss, 

Dwtinctions of . . . 
With red fi^spar . . 
Prinu 
With 



rite, and pornlijry . 
Fertile in metals . , 
Tabular, 

Sites of • . • , 



130 

ibw 
ib. 

131 
ib. 
ib. 

I3t 
i.5«t 

ii. 13S 

i. Sll 
Sit 

ib. 

«1S 
S14 



Sites of 



Digitized by LjOOQ IC 



tNOtX» 



643 



MmeorLeifel 

Sites of . 

Undulated . . 

Sites of . 

Irremlar, 

Sites of. . . . 
Of two sabstances 
Oneiss, witii Bine Siderite 
Gneiss and Mica Slate . 
Gneiss Dec ..... 
Examples of . • . 
Granite, 

Composition of . • 

When termed granitel 

Withsidente . . • 

OfMontBlaiH: . 

Ofthesommit • 

Of the rocks . . 

Of the sontbeni 

parts • • • . 

Ofahuf^grain . . 

The syenites 6f Pliny 

Varieties of . . 

With felspar, qoarta, 

and mica .... 

Varieties of . . 

Of a small crain • • 

Varieties of . . 

Veined 

Mingled 

Ancient senlpture of 
Gnmite and Basalt . . • 
Granite and Clialeedony • 
Granite with Gneiss . . 
Granite and Granitic Por- 

Dolomien's observa- 
tions on .... 
Granites ..... 
Porphyries « • . • 
Monuments of Rome 
Sitesof ..... 
Granite and limestone • 
Granite with Sappare 
Granite with Schorl and 

Garnets 

Granite and Sbite . . . 
Saossnre^s remarks . 
Further observa- 



Granitel>ec« . • , 
Of Ben Nevis . . 
OfSochoDdo • . 
OfOdonTchelon 



InAuvaigne 
Examples of 
Gtanitm, ' 

Described . 
Green . . 



i.214 
ib. 

ib. 

ib. 
216 
ii. £7 
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 
242 
24S 
ib. 

244 
245 
ib. 
246 

I 201 
202 



Granitoid ....•• L 209 

Calcareous granite . ib. 

Arffiihiceoas ... 210 

TaTcoos ib. 

Graniton 202 

Granitio Porpbyroid, 

Described .... 210 

Sitesof 211 

Green Granitel, 

Kgyptian .... 562 

French mannftctonr of 363 

In England and Ireumd ib» 

GraniteL 

Demiitionsof . • . 208 
Kirwan's observations 

on mica ..... 204 

Wemerite .... ib. 

Lehnuunte . . . $06 

Henkelite .... 207 

Graphite 544 

Brongniarf s account of 546 

Laminar ib* 

Granular .... ib. 

OfBorrodale ... 549 

OfChamonni ... 550 

Massive 551 

Laminar ib. 

Green Marble, 

Green, characteristic of 

magnesia .... 366 

Also called serpentine ib. 
Verde antico, 

Laconianoftbean- 

dents "... ib. 

Pluiy's varieties . 367 

Lapis Thebaicus . . ib« 

Verde antico, Brard*s 

account of . . . 268 

Notabricia . . ib. 

Columns of « . . ib. 

Spartan .... ib. 

Other antique marbles 370 

Marble of Polzevera 271 

OfCampan • . ib< 

Marbre d'Eoosse . . 372 

Marble of Anglesey . ib. 

Gypsum, 

Charactenof ... 482 

Primitive .... 484 

Patrm's opinion . . 485 

Geognostic relations of 486 

Colour of .... 487 
Sage's description of 

Montmartre ... 488 

Bones in 492 

Basaltic selenite . . 494 

Primitive .... ib. 

Striped 495 

Crystallised, belongs to 

bUiology .... 407 

2 T 2 



Digitized by VjOOQ IC 



644 



INDSX. 



Cbnmioa « ^ # . • I. 49t 

Grey ...... 498 

Offpanm with Marl i. 56 

Vaaqvelite^ why calM ib. 

ClypsQm with SileK * • 57 

Davite, wby cilM . lb. 

Marble •fVulfHiM . ib. 

Umforai ... ib. 

Vdned • • • H^. 



Icoiirrs, 

Whence the oame . L fTB 
Klaproth'8 anal^^ . ib. 

BilmehioftfaeGennili ib. 
Transpareat . • . S79 
Opake • • . . . ib. 

ladorated Mud .... & 579 
American Tolcanoea . ib. 

Melted snow of Etna 575 

Ernptlon of Macaloba 376 
iNDHiAt ...... 155 

Sites ib. 

Bergman's account of 
Tiberg .... 156 
Patrin's remarks 
on i « . • 158 
Patrin*s farther obser- 
vations • . « • • 
Aceoont of Btetfo- 

dat .... 

Account of Ke9- 

konar • . . 

Entire, iron rock . • 

Mixed, with quartc • 

Ii#n Stone, 

Characters of . • . 
Compact • • . • 
Columnar .... 
Vanegated .... 
External characters of 
Geognostic situation 
Jacintltock ..... 
jMl, the gimdft of the Ite- 



Wh^ not described in 

tittsworiL • . . 
Analysis of not m^ 

fiustory • . . . , 
Coisican jrreen, the fel^ 

dteof wemer . • 
Seems neariy the same 

with' the konlte o( 

tlie Chinese . . . 
Called lemanite . . 
Werner's nephrite 
Various lands of, not 

analysed .... 
Felipnth compact >h 

dicn of ve€tutf>eich 



ib. 

ib. 

159 
161 
ib. 

i. 95 
96 
97 
ib. 
98 
99 
iL 129 

L347 

lb. 

ib. 

ib. 



ib. 
ib. 
348 

ib. 



wniOTV . • • • !• 90 
Not sufficiently known 

to be systematlied 540 

Kastner'sanalsMfe ibw 

Reasons for pvinf an 

account of . . . ih. 

Jad ••'•..••« B. 81 

Jad, Schori, Gwaets . . If 

Jasper^ 

Cliar%rt«nh of ... L 99 

Ba^ianile « . . . • 100 

Whito ..... ib. 

SkiDpic ..... ib. 

Sites of 101 

or Siberia .... ib. 

Extent ..... ib. 

Black . . . • 105 

Red .... 10ft 

Green . ^ . . ib. 

.Striped . * ■ . ib. 

Columnar .... 105 
Jflfipcr, with A^ie and 

ChalcedtJUT , . . • S. 15 

Jxfper and Koraffto . • 17f 

aiBiiBi>p . . ♦ . . 175 

^chiffMC . H, + . ib. 



Kbralite, 
Characters of 

Homstein . . 

PetrosBex . . 

Chert . . . 

Massive . . . 

Common « 
Mtesof 
Unctuous 



Sflk:ennasddstns 
x>iieiT 

Varieriea . 
Keralite with CbkMfte 

Kunkelite, w^ called 

Keralite Dec. . . . , 

Kollanite > . ^ i 

Description 

Pudfhm(wetOBe of EM* 

Noble ffint • 
Chalite « . . 
Observation 
Detached pebble 
Breeding stone 
Site* .... 
Mr. Parkmsoif^ obMN 

vations . • • 
Shells in . . • , 
SQex often recent 
Origin of pebbles 



L15S 
lb. 
154 
ib. 
ib. 
lb. 
155 
ib. 
ib. 
ib. 
156 
ib. 

iL5( 



ib. 
101 
lOf 
ib. 

105 

lOi 



Digitized by LjOOQ IC 



ivon. 



645 



DeljM^ftbKniitNtt 


D. lor 




ib. 


Fdtiin's aocoimt . . 


110 


BmnTs acconnt . . 


119 


Other sites of • . . 


ib. 


Peciilmrt«S^&iid 


lis 

114 


JCkirvtHHrvHBViinC • 


115 


Kidifs accooat .» 


116 




* 118 


ObservatioB • • • 


119 


SheUsin ..... 


1«0 


Varieties of . • « • 


l«l 


Koiiite, 




DistinctioiM of • . 


i. 4«7 


Name ..... 


499 


Chandcn .... 


ib. 


OfCeien 


4d0 


Fefewortli marlrie, igso- 




rantlycaltodParbeck 


ib. 


Porbeck 


431 


Portiand 


ib. 


Called by Da OMta 




Aikaiifsand^tone 


492 


Pierre de tiitte, noelloD 


4SS 


Other kindf of . . . 


ib. 


^?b!i^ troiGMl^tfie 


ib. 


anckirtt .... 


434 


Egyptiaiifl^otiNr . 


ib. 


BnmgamtB acoovit of 


ib. 


Entire, . 




nnMiaaied . . 


440 


^t««f . . 


ib. 


Coarse • • • • 


ib. 


Sitesof . . 


ib. 


CODChitiC, 






441 


IiAB&A2>OR ftock « • • 


ii. 93 


AccoStaf VT .' 


94 
ib. 


Kobl6» or dvidine fel- 




spar 


96 


Norwegian Uae . . 


ib. 


lAvaComoact .... 


313 


Basalt 


ib. 


Artanrencnt- . . . 


314 


Volcame faaMdtki 


315 


With Tsnotts aiib- 




stancea . . • 


ib. 


With ftameiiU of 
^jectednik . 


ib. 


Comnk lava with 


ib. 


Porous buriAm . . 


314 


Brocfaaat^ •eooimt of 


ib, 


Ferbar^Mteas * • . 


317 



OpioiooofnHQas . ii. 319 

Sites ...... 390 

Grey oempact 

lava ... ib. 

^ Grey lavas of FiHJas 321 

Dolowieif s description 3S3 

Breislak'iB accaimt • 394 

White compact lava ib. 

Brown .... 325 

. Porpb^^tic Jani . . ib. 

Dolomieo's account of ib. 

iMvm, MBiapka 09 327 

Lava Vesicnlv . • • • 328 

Qffiderite ...» 971 

Sitesof ib. 

WithlenciCa . . 372 

Sites of . . ib. 

Withaeolite . . iH. 

WitfadMM . • 373 

Withfeh&te. ... ib. 

^elsite lava with sid»- 

rite ib. 

With mica • • ib. 

LaniliteRpck .... 88 

DesciiptioB . • . « ' ib. 

Ultrassarine .... ib. 

Sites ib. 

PatrinTsaecoant . • 89 

Klaproti'tttMlysas . 91 
Sapphire of tna an> 

cients .... 92 

Werner's hunllte . « ib. 

Lemanite 82 

ligmte ....... i. 683 

Gennan Beifart . . 584 

Biongaiarrsaccouitof ib. 

Jet 585 

Friable . . . . • 587 

Fibrous ..... ib. 

Earthy 590 

limestonCf 

Whence the tern car* 

boaaleoflina . . 441 

Geologic- relations af 442 

Convolved .... 443 
Sau8siire*8 remarks 

OS ... • lb. 

Ch^ or kcralite in • 445 

Moral pracifiqea of . ib. 

Gnmnlar, pmnitke . 446 
Rarely mehiliiftirsiM bnt 
• in Siberia and Smuk 

America .... 447 

Remarks on ...» ib. 

FomaAioosal' • • • ib. 

Seldom pose ... ib. 
Grannlar, 

Common ... ib. 
Ueia^a 

« • « lb. 



Digitized by LjOOQ IC 



646 



tXDBX. 



Micaceous . . i. 449 
Compact, 

Characters of . ib. 

CoDchitic .... 451 

Shells in ... 453 
ObsenratioDS on 
Pelas^c or 

oceanic ib. 
Zoophytic, 

Pisolite 456 

Sinapite ib. 

More abundant than 

pisolite ... 457 

Limestone with Arvil . . ii. 53 

Klaprothite, why called ib. 

Marble of Campan ib. 

Limestone with argil ib. 

Limestone with Garnets . 29 

With amorphous garnet ib. 

With crystallised . ib. 

Limestone with Gypsnm , 54 

Lavoisite, why called ib. 

Massive ... 55 

Schistose ... ib. 

Limestone with Olivine . 30 

Olivine and chrysolite 31 

Limestone witli Silex . . 55 

Bertholite, why called ib. 

Kirwan's observations ib. 

Limestone witii Steatite • 30 

Marble, with veins of 

steatite ib. 

With spots . . ib. 

Lime-slate . . * . • . i. ^Sf 

DisUngDished ... ib. 
The ec2caracs>lMiU« of 

WaUerius .... ib. 

Alternation of ... ib. 

Cipoline ib. 

OfMontCenis . . 468 
Micaceous .... ib. 
Common .... 471 
Qnarnr of, at Stones- 
field ib. 



Magnesian Glotenite, 
Laige-greined . . . 
Steatitic bridaof 
Corsica . • . 
SmaU-ffrained . • • 
Magnesianlntrite, 

serpentine porph y r y 
near Florence . . 
Rocks of, described by 
Saossnre .... 
Mlgnesian Limestone, 
Account of .... 
TeflauTs analysis of . 
Dolomite detciibed . 



373 

ibi 
3fh 



sn 

373 

363 
364 
ib. 



Various Ibnns of i 
Often contains tre- 
molite . . . 
Marble, 

Characters of . • . 
Why by cbemists caUcd 

carbonate of lime . 
Geognostic relatioas of 
Duration of .... 
Of the temple of Sempn 
Of Faros and Carraim 

Cipoline 

Grannhu-, 

Egyptian, Ro»o 
antico • . . 
Described • 
Rosso ammlalo • 
Semesanto . . 
Of various colours 
/ (see also note) 
Parian .... 
Sutuesof . 
PenteKcan . . 
Monuments and 
statues of . 
Greek (so called; 
Stataesof . 
Tianslnce&t . . 
Elastic .... 
Of mount Hymettaa 
Ancient Mack 
Varieties of andeot 
Modem . . • 
Of Euland . 
SootfaAd . . 
Irehmd . . 
Norway • • 
Denmark 
Sweden • . 
Russia and Si- 
beria . . 
GejuuuQF 
owisBeraBia • 
France . . 
Spain . . . 
Fortngal . • 
ItalyT . . 
SicOy . . . 
Asiatic . . 
Afirican • • 



ABwricn 
Compact .... 

Ancient. • . 

Modem . . 

Some< 
Conchitic 



Varieties of , 
PMmo di iDort* . 



363 

ib. 
380 

ib. 

ib. 
381 

384 

ib. 

387 
389 

ib. 

ib. 

390 
ib. 
391 
ib. 

lb. 
ib. 
39t 
ib. 

ib. 

ib. 

ib. 
394 
596 

ib. 
396 
997 

ib. 
398 

ib. 

ib. 
400 
401 

ib. 
404 
406 

ib. 
408 
409 

ib. 
410 
41t 
414 
415 

ib. 
416 

ib. 

ib. 

ib. 
418 



Digitized by LjOOQ IC 



IMOBX. 



647 



Oediio di pavone i. 419 

4Eoophytic .... 494 

OrCaen ... ib. 

Other Bites of . 425 

Ofltaly ... 426 

OfSwiBserhuDd . ib. 

Marble of Campan . . ii. 134 

Why ranked amongst 

anomalous rocks . ib. 

Kedg;uttuJar ... 1S5 

Green ib. 

Marble of Minorca . . 134 

Marble Dec S!50 

Mariite i. 475 

Description of • . ib. 

Marble of Florence . ib. 

Massive 477 

Argillaceous marble ib. 

Pictorial ... ib. 

Schistose 478 

Impressions of fish 

in ib. 

OfMontBolea . . ib. 

Other qoarries of . 479 

With impressions ib. 

In different parts of 

the world . • ib. 

Miarite iL 63 

Description of ... ib. 

Site ...... 64 

Saussore's account . 65 

Ocular 74 

With straii^t lines ib. 

Withzigzaji; . • ib. 

Mica and Actinote ... 14 
Mica Slate, 

Arrangement <^ . . i. ItS 

Connexions .... ib. 

Regular 133 

Irregular 124 

Miniled ib. 

Micarel Shite, 

Distinctions .... 31f 

NiOLiTE ii. 74 

Obsidian 443 

InFrance .... 444 

Icefaind .... ib. 

BomrboD .... 445 

TbehUlofMarikan ib. 
Piedra de Galinasm, or 

raven^tone ... 447 
Spallancani's account of 

the Glasses of lipari ib. 

Flkments .... 458 

Unctnons ■ . . . . ib. 

Currents of . • • . 459 



▼itfeotts .... ii. 460 


Entire .... 


461 


Porphyritie .... 
With white fibrous 


46« 


veins . . . 


464 


Capillary ... 


ib. 


Granular . . . 


ib. 


Resinous . . . 


ib. 


Variety of .... 


467 


OUite, 




Characters of . . . 


i. 3«7 


Ophite of the ancients 
Of Chiavenna, analysed 


ib. 




byWeigleb . . . 


388 


Antiquity of . . . 


ib. 


Varieties of .... 


ib. 


Thebaic stone of the 




ancients .... 


339 


Theban ophite of Ltican 


330 


Dark ophite of PUny 


ib. 


Ophite of Boot . . 


ib. 


OfLaet. . . . 


331 


Sitesdf 


ib. 


OUite with Silex . . . 


U. 52 


Pottalite, why called 


ib. 


Oisten, 




The Swedish name, pre- 




ferred 


i. 480 


Description of . . 


ib. 


Usedasfoel . . . 


481 


Different kinds and 




sites of .... 


ib. 


Phosphorite .... ii. 135 


Pisolite L 456 


Pitch^tone, 




Qiaracterof . . . 


918 


Compact *. . . . 


«19 


Lammar .... 


»0 


Pitch-stone Dec. . . . i 


1348 


Pornhyry, 

Name 


L75 


Base ...... 


76 


Werner's 


ib. 


With large crystals of 




'*' 


78 


Black .... 


ib. 


Green .... 


ib. 


Not the ophite of 




Pliny . . . 


79 


Ferber^ varieties of 


81 


Saossare's statement on 


82 


Blue 


85 


Witii smaller crystals, 




Red .... . 


86 


Sitesof . . . 


ib. 


Brown .... 


ib. 


Black .... 


ib. 



Digitized by VjOOQ IC 



64S 



IVOEX. 



Green .... i. 87 

Porphyry with Chalcedooy ii. IS 

Porphyry Dec «S8 

Puy de Dome . . • ib. 

Saxmn metallifenua ib. 

Bomite 239 

'With native gold ib. 

With syWanite . ib. 
With Jendritic gold ib. 
With noble o^ 

&c . . . . • iMO 

Pon^yriD i. 87 

Porphyroid '88 

Porpliyrop . . • • . ib. 
Pumice ...... ii. 438 

Chiedy feUpar ^ . . ib. 

OfUpari 439 

Of Cmnpo Biimco . ib. 

Origin of 430 

Mountain of ... 451 

In beds ib. 

Globular . , . . . 4S3 

Compact ib. 

Porous ..... 434 

Fractare of ib. 

Effects of heat on . 435 

Varieties of ... . 437 

Current ' 440 

Another kind of . . 441 

Porous ...... 442 

Vesicular .... 443 

Fibroq^ felsite . ib. 



Characters of . . • 

Confpact opake • . 

^niitiransparant • 

Unctuous . • . 

Gfanplar 



Other structures of . 
Q«arU with Bamltiq . . 

Tomcemte,^hy oOM 
Quartz with Felspar . » 

Guericite, why c^led 
Qvartz with Iron . . . 

Helmontite, why called 
Qqartz» limestone* and Saos- 

surite 

Qaartz, Schorl, aad lime- 
stone , 

QuartE, Siderite. Oayd of 

Iron 

QoarU with Slate . . • 

C^anbeiite, why called 



i. 146 
ib. 
148 
ib. 
ib. 
159 
ib. 

ii.50 
ib. 
ib. 
ib. 
49 
ib. 

15 

ib. 

14 
50 
ib. 



RviriTB, 

Description .... fi.8$ 

Name ib. 

Sites 86 

With distinct crysdOs 87 



Saline Rocks .... 
Bowles's aecoont of . 
Salt mines, sites of . 
Of Peru, Ullort 
account of 
Kirwan% account • . 
Moimtain of aalt in 

Nortli America . . 
Other salt mines . . 
Entire, Bine, red, 
andnhite . . 
Mixed widi 
gypsum , 
Sandstone Dec. . ,- . 
Sites of . . t . . 
Saussorite, 

Charactenof . . . 
Between basaltin and 

serpentine ... 
Pierre de come ofSana- 

sure 

Roche de corse wHh 
steatite .... 
Ma aw e ria npropen- 

sttyof . . . 
Pusoig to serpen- 
tine .... 
Ofa black base la- 
vaofFerberand 
otfaert . . . 
Com^enne difficnlt to 
determine . . . 
Compact . . . 
Trap .... 
Lydmn .... 
Vulgarly caHed 
touchstone . 
PrhnitiYe or 
sitive . ; 
OfBrochant 
tain . . 
Saotturite Dec. 

DecaycMl .... 
SehistosaKeralite and U1B6- 

stone 

Beeoherite, why called 
Sdustose KereOte aad SkrtB 



SerpenL, 

Cbartcten of . 
Of Mount Ron 
Italian gabbio . 



141 
14f 
14S 

14« 
ib. 

146 
lb. 

ib. 

ib. 
S48 
949 

i.354 

S55 

ib. 

956 

ib. 

ib. 

997 

ill. 

959 
ib. 

960 

ib. 

ib. 
ii.949 

tso 

51 
ib. 
ib. 
ib. 

1994 

99r 

991 



Digitized by LjOOQ IC 



IVOBX. 



6*9 



Of Roth Honi • • • 
OfnoimtCenrui 
Bfagpetic ImU of . ^ 
Umnboldt'ti obser- 
fatioBsoii • . 
Cbenevix's uudym of 
Nephritic . • . • 
Asbestos aiid aaii- 
ttithiis almost 
constant in 
AmJanthQS, obaer* 
▼atioDSOo 
Werners common and 
noble • . . . . 
Italian nephrite . • 
Brocbant 8 verde antico 

not correctly • • 
The noble ctf Werner 
rather belongs to li- 
tholofy or genuno- 

logy 

FnHre 

Mingled 

Serpentine with Baiallin 

Berigniaaite, why called 
Scrpentme with Limestone 
Dark green,>rith grey 
limestone .... 
The same, ^ ith red cal- 
careous spar . . 
Serpentine with Sideite 
BhcolJte, why called 
Sbnle and Coal . . • 
Impressions • • • 
Uniform • « . • 
With impressions . 
Sliells in Ma8>le . . . 
Short Rock .... 

Entire 

Mingled • • . • 

Sidegea, SMenmsJEarth 

Its universality . • 

Chanctenof . • 

Siderite, 

Characters of • . 
HomMende of the Ger^ 

mans. ... 
Primitive tTn> • 
AncieDtbasHt # 
Analysis . . . 

Uniform • 

Mingled • 

Sdnstote • • 

Uniform • 

Mingled . 

Wallerite . • 

SMerite and Basalt . 

Sites . . • • 



i 341 

S4« 
849 

344 

345 
346 

ib. 

350 

351 
ib. 

ib. 



35f 
ib. 

3&S 
i.53 



29 

ib. 

53 

ib. 

191 

ib. 

19« 

ib. 

i. 452 

ii. 132 

331 

ib. 

i. 1. 

3 

4 



ib. 

ib. 

7 

8 

9 

10 

ib. 

11 

It 

13 

ib. 

16 

ii. 165 

ib. 



Siderite with Earthy Pds|Mff fi. 4t 
Syneaite, why called ib. 

Sidente with Febpar . . 
Firmidte, why^ealled 
Graostein of Werner 
Siderite, Felapar, Qraphito 
Siderite with Mica . . 
Democrite, why called 
Siderite with Silex . • 
Hermite, why called . 
Saussore's descrmtion of 
the glazed rock 
Siderite, Unctuoos Quarti, 

Pyrites 

Siderons Glntenite, . 

Ctossed i 

Pudding-stones , . 
Lance-grained . • • 
Bricia oasaltic • • . 
Porphyritic • • 
SmaU-greined . . . 
Semiprotolites • . • 

Lasite 

Ferroginoiis sand-stone 
Siderons Intrite^ 

Intrites distingnished 
from glntenites 

Classed 

Variohtes .... 
Iron-«tone with imbed- 
ded crystab . • • 
Sideromagnesiau Rocks, 
Serpentines .... 

Chlorite 

Chlorite Slate . . . 
Chaiactersof . • 

Sites 

Saussore's o b serf ati en 

Actinote 

Glassy * • • . 

Characters of • 

Serpentine sideroBS • 

Granular « • • 

Compact • . • 

Silex, or Sihceons Earth • 

Siliceoos Gbitenite, 

DescriptioB of . • • 

Origin 

PmWitig slope and brldn 
Sandstone .... 
Largely giiMihUed . 
Orinial and derivative 
Kouanitea • . • • 

Pebbles 

Green .... 
With rolled 



ib. 
ib. 
ib. 

a 

41 
ib. 
39 
ib. 

40 

IS 

135 
136 
I3r 
138 
ib. 
ib. 
139 
141 
14t 



131 
ib. 

133 

134 

126 

i2r 

128 

ib. 

ib. 
129 

ib. 
130 

ib. 

ib. 
131 

ib. 

tm 

fits 
ib. 

226 

227- 

ib. 



Egyptian 
Tnesame 
Jasper bricia 



229 
ib. 
230 
ib. 
ib. 



Digitized by LjOOQ IC 



650 



IHDCX. 



Quartz . • • . i. 390 

SmaU-grained .... ib. 

Knrwan's accoont SSI 

Coane .... 9S6 

Fine ih. 

Saassure's varietiet of ib. 
SUiceooB Intrite, 

Gennan porphyries . 2^ 

Keralite potpbyry . 231 

FeUite 2«2 

Pitcb-stone .... ib. 

Sinapite 456 

Slate. 

Chaiactenof . . • 105' 

Names ib. 

Potoai 107 

Quazriesof .... * ib. 

Mines 106 

Qnarries of Angers . ill 

Ofltaly 118 

Of Germany ... ib. 

Other sites of ... ib. 

Quarry of in Cornwall 119 

Common ..... liO 

Varieties of . . ifi 

Massive ib. 

Slate and Chlorite Slate . ii. 179 

Slate with Lime .... 49 

PaUssite, why called ib. 

Slate witii Magnesia . • 48 

Valentinite, why called ib. 

Slate with Silex .... 47 

Lullite, why called . ib. 

Slate Dec S40 

Smectite, 

CaUed fallcrB* earth . i. 275 

Characters of ... ib. 

Bemnan's mistake . f76 
Da Costa's information 

on ' ib. 

Use of 277 

From CimolBs ... ib. 

Mingled with quartz ib. 

Siteaof ..... ib. 
Steatite, 

Characters of ... 313 

Klaprotfa's account of 314 

Analysis of • • 315 

Da Costa's accoont of 

soap earth or . . ib. 

nurther accoont 316 

Two distinct stmctnres 

of. 318 

Patrin's account of . 319 

WithoUite . . ib. 
OfSanasure. 

Asbestitorm . • 320 

Specular ... 321 

Kock .... 923 



Soft . . . 

Sites of . 

OfLeske . 

Hard . . . 

Compact 

Laminar 

Steatite with Argil 

8taUite» why called 
Steatite and Asl>estos . 
Sanssure's account of; 
rock of . . . 
Substances ejected 
changed by volcanoes 
Limestone . . . 
Parasitic stones in 
Granite . . 
Mica slate 
Slate . . . 
Basalton . . 
. Porphyry 
Sana-sione . 
Sulphuric Rocks 

Jameson's account of 
Porphyry widi sulphur 
^ Mica slate with sulphor 
Limestone with solpfanr 



i 924 
3S» 
lb. 
92d 
ib. 
ib. 

ii. 5S 
ib. 
189 

ib. 

615 
516 
ib. 
517 
518 
ib. 
ib. 
ib. 
ib. 
153 
154 
ib. 
155 
ib. 
ib. 



Talc. 

Distinctions .... L 301 
Common ..... 302 
Venetian .... 305 

OfCfaiU ib. 

Qialk of Brian^oo 304 

Muscovy 305 

Laige foliated . ib. 

Unduhited . . iK 

Involved • . . 306 
Mingled ... ib. 

Massive ib. 

Varieties . . • 307 
Talcous Earthy or Magoflria 288 
Talcous Slate, 

Characters .... 309 
Of SansMnre, described ib. 

TopazRock ii. 127 

Transilient Rocks, 

Distinct fmA tnmii. 

live 163 

Interesting in the study 

ofgeology ... 164 

Tu& . .?\ ... 1.509 

Description of .... ib. 

Veiy modem . . . 510 

Conchitic .... ib. 

Temple of Jupiter O- 

5tl 
512 



lympius, of . 
Orst.Felippe . 



Digitized by LjOOQ IC 



INDBX. 



651 



TraTertiiio # • . i. 51f 
Breisiak's account 

of 513 

PoroDS 518 

Conchitic .... ib. 

Tabalar 519 

7iifo ii. 378 

Composition of . . ib. 

A chief part of volcanoes 380 

Tanas, or pozzolana 4S1 

Pnzzolana .... 4^ 

Trass, or tarras . . 424 

Uses of pozzolana . 426 



Volcanic, 

Volcanoes nnmeroos . S68 

Depth of fuel ... 269 

Many extinct . . . 270 

Chasms 272 

Effects of water . . 278 
Compact lava ... 279 
Kirwan's opinion . . ib. 
Other opinions . . 290 
Compact lava dubious 292 
Basaltic columns com- 
pared with lava 293 
Origin of basaltin . . 296 
Ferrara's system . • 298 
Bubmarine volcanoes 299 
Extinct volcanoes . 302 
Origin of basaltin . ib. 



Vol< 



No modern lava ptia- 
matic iL 



Patrin's theory • • 
Volcano of Stromboli 
Volcano in the Isle 
Bourbon . • . . 
Submarine volcanoes 
Volcano in the Isle of 

Thera 

Submarine volcanoes 
Island of Therasia 
Of Automate 
OfThia . . • 
Eruption of 1767 • . 
Volcanic Qhitenite . . 
Peperino of the Italians 

Bncias 

Catalogue of^ by 

Fanias • . . 

Volcanic Bricta . • 

Peperino . • • 

Leucite lava . . 

Volcanic Intiite . . . 

With leucite . . . 



306 

519 
ib. 
520 

523 
ib. 

524 
525 
526 

ib. 

ib. 
528 
503 

ib. 
504 

505 
515 

ib. 

ib. 
469 

ib. 



Wajckbr i. 273 

Between basalt and chiy 274 
Often a com^enne . ib. 

Wacken and ctaiy . . . ii. 172 



Digitized by LjOOQ IC 



Digitized by LjOOQ IC 



ess 



PLATES IN VOL. L 

Tub vigpoette in the title page is aa ideal view of mountaiiM 
mmd FQcks. The eagle> the chief inhabitant of such r^ons^ 
18 introduced to animate the scene. If allegory be wished, it 
may appear in the dispersion of clouds of obscurity — but 
that the eagle eye of some ftitare Newton will be required^ 
to explain the laws of nature in this difficult province. 

Dom. L Siderous. Grand cavern of 8ta£^ from Pen« 

nant ••; • p. 1 

IL Siliceous. Mont Blanc, from the vale of Cha* 

mouny, chiefly from Sauflsure 1411 

III. AigUlaoeoos. The Andes, near Qvatto, which 

city appears on the upland plain. Hie 
highest mountain on the right, intersected 
with clouds, is Chimborazo. The next, 
a vokano, is Cotopacsi 5 that on the left 
of the plate is l\uiguragua. From Bou- 
gtter*s Rgwre de la Terre, Paris 1749, 4to. 239 

IV. Talcous. AfcNint Rosa, from Saussure 998 

V. Galeareous. Tlie l^rrenees, with the summit 

of Mont Perdu, and Cylinder of Marbor^. 
This view is talUD from the vale of Estaub^ , 
to the north of Bareges. Fh>m Ramond's 

Voyage au Mont Perdu •..., 376 

Vt. Carbonaceous. The coal hill of St. Gflles, near 
Lisge, fimn Lam. T9u dk ia 2Wa See 
. the Appendix *»*.,.«.o#,..*«...«*.M««««r. 540 

FINALS, AT THE BOTTOM OF THE PAGES. 

I. Oiemical instruments, portable fiimace, blow-pipe, 
&c. •..«.•••....•••••.•• • End of Introduction. 



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g54 PLATB8 AHD FINALS. 

2. An Aretia, from Haller^ one of the plants wbidl 
Saussure found at the greatest height of vegeta- 
tion on Mont Blanc ••,>....•• p. 14f 

3* Siktte Acaulis, another plant in a similar situatioa .. S75 

4. Lichen Fwjvraceus, often found on high rocks. 

Hofiman, tab. ix. fig. 2 5S9 

$. Ltc/joi Konc^tt^^ also often alpine. Hoffinan....£nd of toL 



PLATES IN VOL. IL 

Title. An altar of rocks, inscribed in the ancient GredL 
dieracter, " To the Gods Creators." 

Dom. VIL Mount Caucasus, fitHn Pallas p. 1 

VUL Allegorical 36 

IX. Glacier of Bliage, from Saussuie 58 

X. Carpathian mountains, from Townson*s Tra- 

vels in Hungary •••..... •••••^•••••••••.^•••M* 163 

XI. A granitic mountain &lling, by decompo- 
sition, imaginary • 209 

XII. Vesuvius during the eruption of 17 94. From 

Sir W. Hamilton 368 

FINALS. 

1. An Alpine lichen, from Hofiman 1G2 

2. Liclten a^eratus. HofiBman, zliL 1 590 

Mathematical j^te of Veins 633 

Two pbtes of Shells... .« EndofvoL 



Printed hj S. HamiltOD, Wejbridge. 



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655 



THE FOLLOWING 

WORKS ON MINERALOGY 

▲RB PUBLISHED BT 

WHITE, COCHRANE, & CO. 

HORACE'S HEAD, FLEET-STREET. 



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of the Globe. By John Williams, F. S. S. A. Mineral Survey- 
or. The Second Edition, with an Appendix containing a more ex- 
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3. Pbtrificata Dbrbibnsia^ or Figures and Descriptions 
of Petrifactions collected in Derbyshire. By William Martin, 
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^56 WORKS ON MIVBRALOOT. 

4. OuTLiKBS of an Attempt to establish a Knowledge of Ex- 
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tin, F.L.S. &c. In Octavo, 8*. in boards. 

5. Specimens of British Minerals, selected from the Cabi- 
net of Philip Rasuleigh, Esq. of MenabiQy, F.R.S. and F.A.S- 
With general Descriptions of each Article. In two parts qnaito* 
with coloured Engraving, price Four Guineas in boards. 

6. British Mineralogy, in Cdoured Figures with Descriptioiis 
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tinued in Numbers published every other month, price 5^. each. 

7. By the same Author, Exotic Mineralogy, or Coloured 
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