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HARVARD 
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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  ciitumtuiicc  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 


IWva 


tones  lax. 


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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  teWweartrtwrfc 
JncuBBse  the  nomenclature*  the  poverty  of  which  has  loiig 
bean  regretted  by  Saussore^  and  other  able  authors.  Buihn 
pwmnta  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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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 
aioiMeiWitfeainthos^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« 
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W  X  UriHOJMICTIOIk 

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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4 


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. 

"'^  jf^lig  |MttiwtONiV<MCjB0iil.j»n»p.4ft. 

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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.    SniMia^S"'"  If dittiiyiMi||it  from  ^ffkfnemmi,  jaA  *     '-'  ^' 

in  one  pMige  calls  it  vn  r^findemaU  en  mm  qwtotwv. 

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

Sanssnre,  $  aa4^^regaiJirthem  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. 


flBkmiliti 
'^xplaii 


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GooqIc 


^^ 


IVTXOOVOTIOM.  Xiit 


J?'^ 


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 


•  fetnf,  954.  t  Pfif,  97 1,  374. 


0 


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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- 


^       ^  •F«r.s;«. 


t  Feir.  078. 


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ft 


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 

*  SeetfaeOpaicofiSttki,ton.3uu.  lk£lnl790,4tD.p.SS^  ^ 

-  •    c  ^ 


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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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nouAxm  TIC.    e«i«f04lM. 


rf.marki« 


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. 


Digitized  by  LjOOQ IC 


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 


Digitized  by  LjOOQ IC 


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  breadth^  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  witeifl,  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  mentions 
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  cemented  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  fargotteii  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  incrcawrf 
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  niB|ili'iwiuit  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  gfaoiJfliiofiibe  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  Iheaaitiftii  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  tiydBieai 
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 
ygodactd;  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  defJeyod  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  ntpei;fta|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  vicLii^iffef ^^'>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  regretted  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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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  copjectored  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 


DigtfJra^oo^le 


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.  ^^ 


1 


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^0: 


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' 


• 


fO:"' 


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 


i 


-   313 


i^- 


.-^r 


«l| 


Basaltui. 


1? 


*    f 


J>* 


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914  dK  BOMJiv  xn.    roLCMmcm 


»# 


.# 


JMiK 


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; 


I^H'Tl^- 


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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. 


J' 


ni%  fix)m  Vesuvius.     'Rie  appearance  is  rather 
vitreous. 


s^ 


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  Ftfbefii^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 


u 


€ 


^ 


•  i.  S51. 


V 


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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. 
fcetettrlcfty,  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. 


I 


^ 


M 


•  i.  $51. 


'4'^^ 


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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  occjaiopBi 
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  neighbor 
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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Digjtized>i 


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 


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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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'"  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. 


k 


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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  0 
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^ 


n^ 


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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 


4  %■<.  ■ 

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^ 


Hn  a 


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  .  ^  ^ 


f 


^ 


?• 


m 


»t-r 


«'* 


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n 


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  traversed  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 


Digitized  by  CjOOQIC 


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 


DigrtizedbydOOglC 


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 


Digitized  by  VjOOQ IC 


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  emUmmi 
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  regrrtted  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^ 
oftenconfoiunded  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 
laaiwiaalinfl  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  ;   * 


Digitized  by  LjOOQ IC 


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  tawcaaod  by 
tbeniy  cqptMns  galena  witka  fittfetiidiaiad  pynJeay 
baryta,  fluor,  and  qmutM.  TUb.^ 
tbedithaod  ninth  hctar.  One 
veiha  of  :tii  and  joi  ntwr,  die.  haaiar  buts^tAmfffi 
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^^ 


Digitized  by  VjOOQ IC 


«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  ^otfAufty  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  Uctwe nl  miwi  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  Iteanteila 
to  «ii)oh  dqilh,  Ihls  gieaaite  is  m-.^'ptt^  ptMt 
ifqnfiosed  of  jrfatas^f  fcbtu^r;  waoai  or.hatJimi* 
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  iioUaliliwiiit^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  argHairiwwis 


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  isjepdrted 
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^^»"WW 


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 


Digitized  by  LjOOQ IC 


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. 


* 

Digitized  by  VjOOQ IC 


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 


% 

Digitized  by  LjOOQ IC 


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. 


Digitized  by  VjOOQ IC 


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. 


Digitized  by  LjOOQ IC 


«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. 


Digitized  by  VjOOQ IC 


$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^' 


Digitized  by  VjOOQ IC 


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. 


Digitized  by  LjOOQ IC 


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. 


Digitized  by  LjOOQ IC 


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^  inupctatd  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  hnwIikiiJB  wdit^wuft  P»<nM!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 
tgaymad  by 'ooiwiderihlB  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 


Digitized  by  CjOOQIC 


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 

\A 

to 

O 

» 

«- 

-= 

s 

2; 

0  fc 

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  *« 
0  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  yoMtlun 
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  inrtruLiifa 
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  owoly  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>  Rampasse  discovered  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  jiiWIii  imiiiB  tht 
detail  giveoofit,  oa  ajpapnnt  <if  ite  unnwifnyuiig  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  iftamntrntHmt^ 
aspaciidiy  if  irouj  90  piwa  to  oxsKbliDaw  bo  ixMid  in  it. 
either  uoitfid  or  in  oDmbinatiant  in  tPO  giaae  n  nwiKrtion. 
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  ganwnl  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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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 


Digitized  by  VjOOQ IC 


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     porphyry 
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      .... 
Maawerianpropen- 

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  obserfatien 

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  . 


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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 


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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. 


1.  The  Natdral  History  of  the  Mineral  Kingdom,  icla- 
tive  to  the  Strata  of  Coal,  Mineral  Veins  and  the  prevailing  Stiau 
of  the  Globe.  By  John  Williams,  F.  S.  S.  A.  Mineral  Survey- 
or. The  Second  Edition,  with  an  Appendix  containing  a  more  ex- 
tended View  of  Mineralogy  and  Geology.  By  James  Millar, 
M-  D.  F.  S.  A.  S.  and  Lecturer  on  Natural  History  and  Chemis- 
try, Edinburgh.  In  two  thick  Volumes  Octavo,  illustrated  with 
Engravings,  price  24s.  in  boards. 

2.  The  IJhilosopht  of  Minbraloot.  By  Robbrt  Town- 
ion,  LL.D.  F.R.S.  Edin.  &c.  Author  of  Travels  throu^ 
Hungary.    In  Octavo,  with  Engravings,  7*.  boards. 

3.  Pbtrificata  Dbrbibnsia^  or  Figures  and  Descriptions 
of  Petrifactions  collected  in  Derbyshire.  By  William  Martin, 
F.  L.  S  Corresponding  Member  of  the  Literary  and  Philosophical 
Society  of  Manchester,  and  Honorary  Member  of  the  Geological 
Society  of  London.  In  one  Volume  quarto,  with  fifty-two  coloured 
Engravings.  2i  12«.  6d.  in  boards. 


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^56  WORKS   ON  MIVBRALOOT. 

4.  OuTLiKBS  of  an  Attempt  to  establish  a  Knowledge  of  Ex- 
traneous Fossijbs  on  Scientific  Principles.  By  William  Mar- 
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 
(h)m  the  Primitive  Crystals  to  their  Amorphous  States.  By 
Jambs  Sowerbt.  No.  1  to  68.  royal  8vo.  13/.  5s,  Od.  To  be  con- 
tinued in  Numbers  published  every  other  month,  price  5^.  each. 

7.  By  the  same  Author,  Exotic  Mineralogy,  or  Coloured 
Figures  of  Foreign  Minerab,  as  a  Supplement  to  British  Mineralogy. 
Nos.  1,  2,  3.  I5i.  To  be  continued  every  odier  month  inFtve-shil- 
ling  Numbers. 


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