MINERALOGY 
 
 d F THE 
 
 SCOTTISH ISLES; 
 
 WITH 
 
 MINERALOGICAL OBSERVATIONS 
 
 MADE IN A TOUR THROUGH DIFFERENT PARTS OF 
 
 THE MAINLAND OF SCOTLAND^ 
 
 AND 
 
 DISSERTATIONS 
 
 UPON 
 
 E A T AND KELP. 
 IN TWO VOLUMES, 
 
 Jllu Grated with Maps and Plates. 
 
 B Y 
 ROBERT JAMESON, 
 
 FELLOW OF THE ROYAL AND ANTIQJJARIAN SOCIETIES OF EDINBURGH, 
 
 LINlftEAN SOCIETY OF LONDON, PHYSICAL SOCIETY 
 
 OF JENA IN SAXONY, 5sV. 
 
 was, quam ingenlofiffliiias fiftioncs fcqiti praftat ; Nature 
 myfteria pctius indagare qiuvn divinarc. 
 
 BERG. De Form. Cryflallor. 
 
 VOL. I. 
 
 EDINBURGH: PRINTED BY c. STEWART & co. 
 
 TOR B. WHITE & SON, FLEET - STREET, LONDON; AND \V. CRE.ECIT, ErlNr 
 
 i 8 o o, 
 
EAR 
 
 SCIENCES 
 
TO 
 
 * EARTH 
 
 JOHN WALKER, DD. MD. 
 
 REGIUS PROFESSOR OF NATURAL HISTORY, 
 
 AND 
 
 KEEPER OF THE MUSEUM OF THE UNIVERSITY 
 OF EDINBURGH ; 
 
 THIS VOLUME, 
 
 OF THE 
 
 IS DEDICATED, 
 
 OF HIS MUCH OBLIGED PUPIL, 
 
 AND OBEDIENT 
 
 HUMBLE SERVANT, 
 
 THE AUTHOR. 
 
 SHERIFF-BRAE, LEITH> ") 
 20. JULY, l8oO. 
 
 105 
 
vi . PREFACE, 
 
 icencry; ict him recoiled*, that to indulge in fuch defcrip- 
 tions was incompatible with the defign of this work. I do not 
 defpife thofc ornaments ; and I hope that I have not been in- 
 .{enfible to the emotions which naturally arife from the retired 
 and finking fcenes which often bur ft upon me in the unfre- 
 quented tradls which my purfuits led me to explore : but I 
 have thought it foreign to my purpofe to obtrude thefe things, 
 upon the public. 
 
 Another refolution I had formed to myfelf, and which 
 partly indeed led me to choofe the form of a journal, was, to 
 ihun the faf cinating evil of fpeculation .and hypothefis, which 
 mars all faithful obfervation. It would ill fuit my talents to 
 venture upon deep fpeculation, were I inclined ; and perhaps 
 the ftate of mincralogical knowledge forbids it. It is a fitter 
 tafk for me to record faithfully what I have myfelf examined, 
 and to give a fair report of the materials which were collected, 
 than to expofe myfelf, by the form or arrangement of the worfc^ 
 to the danger of having the facls twifled and perverted by hy- 
 pothefis, the rage for which is as remarkable in this as in the 
 other fciences. 
 
 While, in mineralogical purfuits, there is much to interefl a 
 philefophical mind, the objed of true value is its application 
 
 to 
 
PREFACE. 
 
 to economical purpofes. I fear that the theories of the { 
 tion of the earth, interefting as they are, often miflefc 
 mind, and pervert the underftanding ; and thofe who yic 
 them, become fo involved in delufive fpeculations, fo bji; 
 fact and experience, that, like Archimedes, they find bii 
 thing wanting to raife worlds. 
 
 Of the utility of this fcience there can be no 
 more particularly when it is freed from the vague fup 
 tions of the theorift. It is a ground-work, without whijj 
 obfervations of the geologift, and the labours of the m; 
 will ever be uncertain, and of little utility. It is a fcif 
 the cultivation of which will raife a country to importance 
 exciting new fources of induflry, even in fituations 
 the labours of the hufbandman will be employed in 
 But, though I am well convinced that the importance of < 
 thing in mineralogy is in proportion to its accuracy, I w 
 not be underftood to reprefent thefe notes as a complete ac 
 of the mineralogy of the countries of which they treat I 
 them to the public as an imperfect outline. The mineralo 
 hiftory of a xjountry is to be accomplifhed only by fludyi 
 leifure all the varieties and difpofition of the flrata and 
 and the appearances of the mountains and valleys : an in 
 -gation which the utinoft care, in a rapid furvey, muft lea 
 
 b 2 i 
 
particulars imperfect, efpecially when the nuneralogiit is 
 xed with the difficulties of travelling among unfrequented 
 
 iave in this, as in a former work, feparated the particu- 
 
 :count of the ftrata and veins from that of the particular 
 \ as the com-mon method of conjoining them appears of- 
 
 > lead to confufioii, and can never be fufficiently correct. 
 
 Scribing the foflils, the method and nomenclature of the 
 jineralogifts has been followed. The chemical characters, 
 ; form even the foundation of many mineralogical fyftems^ 
 $ ieldom employed ; from a conviction that the chemical 
 i>f mineralogy^ notwithstanding the late improvements 
 i art of, analyfis, is ftill to be confidered as imperfecl. 
 ave only to obferve the contradictory refults obtained by 
 left chemiils in decompofing the fame foml, to be con- 
 
 d that the analyfis of the prefent day, although much im- 
 
 ,'d fince the time of Bergman, is ftill of no very great 
 
 ?ji mineralogy. 
 
 ;ie drawings of feenery, and the mineralogical plans, which 
 mpany this work, were executed by the elegant pencil of 
 friend Mr. Charles Bell. In the views of feenery, he has 
 [>ily exprefled the different characters which the rocks a- 
 je from the effects of the weather j a circumftance which 
 
 render? 
 
CONTENTS, 1 
 
 VOLUME 
 
 '. /. From Edinburgh, by Glajgow, to the Craig of 
 
 Page i 
 
 //. Defcription of the Fojfils mentioned in the pre- 
 ' Chapter. 
 
 III. Jin RAN. Size and Situation of the I/land. 
 Mountains, Surface, Effir. Brodick Bay, and its 
 ms ; comprehending Cory-gills, Glen-Cloy, Glen-Shir- 
 Hoatfield, and Glen-Rofa. 
 
 JV, Defcription of the Fojfils mentioned in the pre- 
 i Chapter. 
 
 ty. Cory, Cock of Arran, and Loch Ranzn, 
 VI. Defcription of th#> Fojfils mentie&ed in the pre- 
 
 Chapter* 
 
 44 
 67 
 
xil CONTENTS. 
 
 CHAP. VII. Glen-Catacol, Glen-Erf ay, Glen-Clachan, Shif- 
 kin^ Tory-Lin, Benin-Head^ Whiting Bay, Lamlajh Bay, 
 and Lamlaft I/land. - - Page 94 
 
 CHAP. VIII. Defcription of the FoJ/ils mentioned hi the 
 preceding Chapter. 1 1 6 
 
 OBSERVATIONS to be made for the farther Elucidation 
 
 of the Mincralogical Hiftory of Arran. 123 
 
 CHAP. IX. Outline of the Mineralogy of the I/land of 
 Bute ; with Obfervations upon the Formation of the Bed 
 of the Clyde, and an Account of the Route from Bute to 
 the I/land of Jura. 12^ 
 
 CHAP. X. Outline of the Mineralogy of the I/lands vf 
 
 IJla and Jura. - - 148 
 
 CHAP* XL Defcription of the FoJJils mentioned in the prc- 
 
 ceding Chapter. '.' * - 178 
 
 CHAP. XIL Voyage from Jura to the Slate I/lands of Sett 
 
 and Eafdale ; thence .to Oban and the I/land of Mull. 1 9 1 
 
 CHAP. XIII. .Outline of the Mineralogy of the Ijland G 
 Mull. - - : ' r. 
 
 CHAP. XIV. Defcription of the FoJ/ils mentioned in foe 
 
 preceding Chapter. *- - ^25 
 
 CHAP. XV. Obfervations on the Method of D if cover ing ' 
 Coal. &> g? *r 236 
 
 P ' - INTRO- 
 
INTRODUCTION, 
 
 CONTAINING 
 
 An AbftracJ of the Wernerian Account of the different Kinds of 
 Mountain Rocks ; with Geognojiic Obfervations on the Strata of 
 
 the Scottift Ifles, and fuch parts of the Mainland as are mention- 
 ed in this Work, 
 
 I mall frequently have occasion to mention ill this work 
 the divifion of rocks into Primary, Tranfition, and Stratified, it 
 may be ufeful to many to know the chara<5lers by which thefe 
 different rocks are diflinguiflied. I am the more anxious to do 
 this, as we have not, as yet, in any Englifh publication, an ac- 
 count of the divifion. To this I mall add a few geognoftic ob- 
 fcrvations upon the different rocks to be found in the Scottilh 
 
 C ifles, 
 
XIV INTRODUCTION. 
 
 ifles, and in thofe parts of the Mainland which are mentioned 
 in the following Outline. 
 
 According to the latefl obfervations, all the ftrata, of which 
 our globe is compofed, may be arranged under the follow- 
 ing clafTes : The Primary, (Urgeburge) j the Tranfition, 
 (Ubergangsgeburge) ; the Stratified, which comprehends what 
 are called the fecondary ftrata, (Flotzgeburge) ; and the Volca- 
 nic, Alluvial, (Aufgefchwemmte.) 
 
 I mall now mention the diftindlion between thefe different 
 kinds of ftrata ; and, fir ft, of the 
 
 Thefe ftrata are characflerifed by their never containing the 
 remains of animals or vegetables, nor alternating with fuch 
 ftrata as contain thefe relics. Humbold has alfo obferved that 
 the primitive ftrata in Europe are always inclined towards the 
 N. E., while the ftrata of the fecondary mountains dip towards 
 the S. E. 
 
 It is to the celebrated mineral ogift John Gottlob Lehman 
 
 that 
 
INTRODUCTION. XV 
 
 that we are indebted for the very important difcovery of the 
 divifion of mountains into primary and fecondary. Since he 
 wrote, fucceeding mineralogifts have confirmed the truth of 
 his obfervations, and have thus raifed geology, from a vague 
 and confufed ftate, to a high pitch of certainty and utility. A 
 few writers have tried to overturn this diftinclion, by averting 
 that it is fanciful ; yet thefe fpeculations, like all others not 
 founded on truth and accurate inveftigation, have funk into 
 deferved oblivion. 
 
 The primitive ftrata are the following : granite, gneifs, 
 micaceous fliiftus, ardefia, iienite, porphyry, primitive lime- 
 ftone, primitive greenftone, greenftone fhiflus, ferpentine, 
 quartz, pitchflone, and topaz rock. Granite is confidered 
 by Werner as the fundamental rock, or that upon which 
 all others are laid, and it is but very rarely that it alternates 
 with other rocks. It is difpofed in layers or ftrata, which 
 are often enormoufly thick, and frequently horizontal, and ex- 
 tend thus for many miles through a whole chain of moun- 
 tains. All the other primary ftrata alternate with each other, 
 but never with the tranfition or ftratified rocks. The green- 
 ftone, wacken, and pitchftone are the only exceptions ; the two 
 iirft being common to the three firft-mentioned formations, 
 but the pitchftone only to the primary, and ftratified, or flotz- 
 geburge. The 
 
 c 2 TRAN- 
 
XVJ INTRODUCTION. 
 
 TRANSITION, OR UBERGANGSGEBURGE 
 
 comprehend all thofe rocks, the lowermoft ftrata of which 
 contain few or no petrifactions ; in the higher they are more 
 abundant ; but only petrifactions, the originals of which no 
 longer exift. Thefe mountains alfo abound in metallic veins 
 and in grottos. Thofe of Antiparos, Crete, &c. are in this 
 kind of rock ; as are the Hartz metalliferous mountains, and 
 thofe of Derbyfhire. They feem to have been formed af- 
 ter the primitive, and earlier than the ftratifiecl (flotzgeburge) 
 rock. The flrata of this formation are the following ; gra- 
 wacken, grawacken flate, fandftone, fome fpecies of ardefia, 
 greenflone, niandelftone, limeilone, and Dr Reufs conjectures 
 that fome fpecies of fienite and porphyry * may belong to this 
 clafs of rocks. The 
 
 STRATIFIED (Flotzgeburge) 
 
 appear to have been formed after the tranfition rocks. They 
 confift of fandflone, limeftone, argillite, with numerous petri- 
 factions ; 
 
 * Mineralogifehe Geographic von Bohmen, ^ Band, $ 177, 
 
INTRODUCTION. XV11 
 
 factions ; alfo, bafalt, ihiftofe porphyry, pitchftone, greenftone, 
 wacken, and the various coal ftrata. 
 
 From the view of thefe three formations, we obferve that the 
 greenftone and wacken occur in every one of them, but the 
 bafalt is peculiar to the ftratified rocks. The 
 
 VOLCANIC 
 
 comprehends the various ftony fubftances altered by action ot 
 fire : thefe are, lava, pumice, vocanic afhes, and volcanic tuff. 
 The 
 
 ALLUVIAL 
 
 confifl of gravel, fand, clay, &c. and are the debris of the 
 other ftrata. 
 
 Having thus mentioned the divifion of the different rocks> 
 according to their relative antiquity, I fliall now make a few 
 general geognoftic obfervations on the rocks of the Scottish 
 ides, &c. I {hall firfl mention the 
 
 ERI- 
 
XVlll INTRODUCTION. 
 
 PRIMARY ROCKS. 
 
 GRANITE. This rock forms but a fmall portion of the Scot- 
 tifli ifles, it being found only in the ifk of Arran, and in the 
 low part of Mull called Rofs, and in the Shetland iflands. 
 Upon the Mainland, however, I obferved it forming moun- 
 tains in Sutherlandfhire, a confiderable part of the county of 
 Aberdeenfhire feems to be formed of it, and alfo the lofty 
 mountain of Cruachan upon the weft coaft. Granite veins are 
 pretty frequent in feveral of the iflands, as in Arran where 
 they traverfe the common granite, and in Coll, Tiree, Rona, 
 the Orkney and Shetland iflands, &c. where they traverfe mi- 
 caceous fhiftus, gneifs, or hornblende flate. Upon the main- 
 land, in the route from Bernera to Perth, the granite veins are 
 extremely common. 
 
 GNEISS. This rock I obferved in Coll, Tiree, Rafay, Rona, 
 in the Shetland iflands, and in feveral places upon the Main- 
 land of Scotland; in particular it forms the fummit of the 
 high mountain called Ben Lomond. It fometimes alternates 
 with micaceous fhiftus and hornblende rock, and it is traver- 
 fed by granite veins, as is the cafe in Coll, Rona, &c. 
 
 MICACEOUS SHISTVS-. This rock forms a portion of the ifles 
 
 of 
 
INTRODUCTION. Xix 
 
 of Arran, Bute, and Mull ; it is juft to be obferved in Coll, but 
 a very confiderable extent of the Shetland iflands are compofed 
 of it. In the Mainland it appears to extend through the whole 
 diftricl of Cowal, and to the extremity of the iflhmus of 
 Cantyre, and in all the country from Bernera to Dunkeld ; and 
 from Dunkeld to Loch Lomond by Inveraray, the micaceous 
 fhiftus is the prevalent rock. Upon the eaft coaft it is frequent 
 among the other primary ftrata. It alternates with fhiftofe 
 quartz in the ifland of Mull, and with hornblende and gneifs 
 in the ifland of Coll ; and it is to be obferved in feveral places 
 pafling to ardefia, and it is traverfed by granite veins, and has 
 pieces of granite enclofed in it. 
 
 Primitive argillaceous fhiftus. This rock occurs 
 in Arran, Bute, Ifla, Jura, Eafdale, and Seil. In Ifla there is a 
 fpecies of it which contains pieces of granite, which, however, 
 feem to have been formed at the fame time with the ardefia. 
 In Eafdale, Seil, Bute, and Arran, it it quarried for economical 
 purpofes ; but the flate of Eafdale is by far the befl.. 
 
 SIENITE. A rock nearly allied to fienite feems to form the 
 cralg of Ailfa ; it alfo forms part of the ifland of Arran, and 
 the lofty Cullin moutains in the ifland of Skye. 
 
XX INTRODUCTION. 
 
 PORPHYRY. I obferved fragments of porphyry among the 
 granite mountains in the ifland of Arran, which is probably of 
 primitive formation, and the porphyry, which forms fo con- 
 fiderable a part of the hill of Glamofcard in Skye, feems to 
 be of primitive formation. 
 
 PRIMITIVE LIMESTONE^ or MARBLE. This rock^ occurs in 
 vertical flrata at I-columb-kill, alfo in the ifland of Tirie, and 
 in feveral parts of the Mainland. I obferved it alternating 
 with primary rocks, particularly at Portfoy, where it is in 
 vertical ftrata and alternates with talcaceous ihiftus and fer- 
 pentine. 
 
 PRIMITIVE GREENSTONE. I have not met with this rock in 
 any part of Scotland excepting in the ifland of Iflay, yet I 
 think it very probable that a careful examination may difcover 
 it in many places. 
 
 SERPENTINE. There are no ftrata of this rock in the He- 
 brides, nor the Orkney iflands ; but in Shetland it forms ex- 
 tenlive hills, and there it feems evidently to be of primitive 
 formation. At the intere fling fpot, Portfoy, there are great 
 vertical ftrata of ferpentine alternating with marble, talcaceous, 
 and hornblende Ihiftus. 
 
INTRODtJCTION. 
 
 Z. In the iilands of Ifla and Jura there are mountains 
 of granular quartz, and it is there to be obferved alternating 
 with, and pafTmg into micaceous fhiftus. In the ifle of Coll 
 there are alfo confiderable rocks of granular quartz. In the ifl- 
 and of Tirie I obferved the rare appearance of a vein of gra- 
 nular quartz traverfing ftrata of micaceous fhiftus and horn- 
 blende Hate. In Caithnefs the mountain of Scaraban is com- 
 pofed of quartz ; and at Portfoy there is a hili which affords 
 ihiflofe quartz. In many places veins of quartz are to be ob- 
 ferved traverfing the primary ftrata, and in the ifland of Bute 
 there is a quartz vein which prefents appearances irreconcile- 
 able with the Plutonic theory. 
 
 NE. The only fpecies of this ftone which I have 
 ever feen, that may be confidered .as primary, is that upon the 
 hill of Glamofcard in the ifland of Skye. It there feems to al- 
 ternate with porphyry, but of this I am not as yet certain. In 
 the ifland of Arran there are appearances of pitchftone in the 
 form of veins traverfing the granite, but as all veins are of an 
 after formation to the rocks which they traverfe, this cannot 
 be reckoned equally old with the granite, or other primitive 
 rocks. 
 
XXU INTRODUCTION. 
 
 TRANSITION ROCKS, (Ubcrgangfgcburgc.) 
 
 GRAWACKEN. This is a rare rock in the diftricts through 
 which I paiTed. The only appearance I ever noticed was a 
 fmall portion lying on ardefia in the ifland of Seil. 
 
 GREENSTONE. The greenftone of the iiland of Mull appears 
 to belong to this formation, as it is found near to limeflone 
 that contains belemnites. 
 
 LIMESTONE. This fpecies is found in the iiland of Mull, 
 and contains in it cornu ammonis and belemnites ; hence I 
 reckon it to belong to the traniition rocks. 
 
 STRATIFIED ROCKS, (Flotegcburge.) 
 
 SANDSTONE. Of this I obferved two kinds, the filiceous 
 and argillaceous. 
 
 The filiceous does not frequently occur. The fandftone of 
 the ifland of Rume approaches nearly to this kind, and in the 
 Orkney iflands there are ftrata of filiceous fandftone that al- 
 ternate 
 
INTRODUCTION. XXlii 
 
 ternate with argillaceous fandftone. Argillaceous fandftone 
 forms the Cumbray iflands, the fouth extremities of Bute and 
 Arran ; and it alfo appears in the iflands of Seil, Mull, Eigg, 
 Skye, Rafay and Scalpa. Almofl the whole of the Orkney 
 iflands are compofed of argillaceous fandftone, but it forms a 
 very fmall portion of the Shetland iflands. It alfo fkirts the 
 eaft coaft of Scotland from the Pentland Firth to the fmall 
 fifhing town called Buckie ; and again this fandftone makes 
 its appearance near to Aberdeen, and continues along the more 
 all the way to the Frith of Forth. 
 
 LIMESTONE. In the ifland of Arran there are considerable 
 ftrata of limeftone which is covered by argillaceous fandftone ; 
 and in fome places the limeftone and fandftone alternate. In 
 the Orkneys limeftone is to be obferved covered by fandftone, 
 and even traverfed by veins of fandftone. 
 
 ARGILLITE with numerous fhells is found in the ifland of 
 Arran, and in the ifland of Eigg. 
 
 BASALT. This rock, which, as we have before obferved, is 
 peculiar to the Flotzgeburge, is found in almoft every part of 
 Scotland, either in ftrata, or in veins. I obferved it difpofed 
 in ftrata in the ifland of Seil, at Oban, in the iflands of Mull, 
 
 d 2 Eigg, 
 
liigg, Canna, and Skye ; and thefe ftrata either alternate with 
 argillaceous fandftone, wacken, or greenftone. Frequently alfb 
 veins of bafalt traverfe thefe ftrata. 
 
 BASALT VEINS. Thefe veins are extremely common in mofc 
 jf the Hebrides, but are rarely to be obferved in the Shetland 
 >r Orkney iflands. I obferved them traverfing granite, gneifs, 
 micaceous fhiftus, iienite, porphyry, hornblende ilate, fand- 
 ftone, and limeftone. In the ifland of Arran there are feveral 
 very remarkable veins which are partly formed of bafalt. 
 Thus in Glencloy there is a vein^ (traverfing clay porphy- 
 ry), which is compofed of bafalt in the middle, but, upon one 
 fide is fandftone breccia, and, on the other is hard filiceous 
 fandftone. At Tormore, upon the weft, fide of the ifland of 
 Arran, there are feveral other vei>y remarkable veins partly 
 formed of bafalt. 
 
 BASALT TUFF. I obferved this rock at Dumbarton caftle, 
 and in the iflands of Mull and Canna, where it always accom- 
 panies rocks of trap formation. In the ifland of Canna it is 
 remarkable for having pieces of wood inclofed., 
 
 . This curious foflil is found very frequently in 
 
 the 
 
INTRODUCTION. XXV 
 
 the ifland of Arran, but generally in the form of veins. Thefe 
 veins traverfe the common argillaceous fandftone, and are of- 
 ten of great magnitude, It is alfo difpofed in ftratified veins 
 along with other fubftances at Tormore in Arran. In the 
 ifland of Mull it feems to lie between fandftone and bafalt ; 
 but in Eigg it forms confiderable veins traverfing bafalt. This 
 foflil, which was before confidered as very rare, is thus fhewn 
 not to be fo uncommon ; and I have lately learned that it has 
 been obferved in veins traverfing fandftone in Morven, and ia 
 veins traverfing bafalt at Ardnamurchan. 
 
 GREENSTONE. The country between the primary ftrata at 
 Dunkeld, and the banks of the Frith of Forth prefents many 
 appearances of frotz greenftone ; and, in the fame tracl there is 
 alfo wacken of a fimilar formation. 
 
 COAL. In the ifland of Arran there is a flratum of blind 
 eoal inclofed in fandftone. In Mull, Eigg, Canna, Skye, it is 
 obferved always ftratified with bafalt or wacken. 
 
 VOL- 
 
XXVI INTRODUCTION. 
 
 VOLCANIC ROCKS* 
 
 have never been difcovered in Scotland. 
 
 ALLUVIAL. 
 
 Of thefe there are examples in the Highland vallies, where 
 the debris from the mountains are depofited in beds and cover- 
 ed by heath. The great banks of fand, and the immenfe beds 
 of peat which we find fometimes alternating with beds of clay 
 or fand, are of this kind. 
 
 MINE- 
 
 * Of the pfeudo- volcanic rocks, which are different fpecies of rocks that have 
 been expofed to accidental fire, we have inftances in Fifefliire. Upon the fhore 
 between Dyfart and Eafter Wemyfs I picked up feveral fine fpecimens of porcella- 
 nite, which feems to be the clay that accompanies the coal altered by fire, as mattes 
 of fcorise and charcoal ftill adhered to it. 
 
MINERALOGY 
 
 OP THE 
 
 SCOTTISH ISLES. 
 
 CHAPTER I. 
 
 From Edinburgh, by Glafgow^ to the Craig of Atlfa* 
 
 jLN travelling from Edinburgh to Glafgow, by the Living- 
 ftone road, the country continues, for a confiderable way, 
 pleafant and well cultivated ; but as we approach the Kirk of 
 Shotts the fcene is much altered. In place of inclofed fields, 
 exhibiting the operations of thriving agriculture, extenfive 
 mofs grounds appear, forming a ftriking contrafl to the cul- 
 tivated country through which we had juft patted. Happily, 
 
 A however, 
 
j FROM EDINBURGH TO AILSA. 
 
 however, thefe inofTes arc now viewed in a more favourable 
 light than heretofore : the brown burnt-like afpect of a peat 
 moor does not now flrike the mind with ideas of barenefs and 
 fterility ; as we know, from experience, that labour and a little 
 expence may foon convert them into luxuriant fields. A few 
 miles after pafling this defert, we come in fight of Glafgow ^ 
 but its low fituation, and the want of hills, render it, when 
 compared with Edinburgh, far lefa interefting as a picturefque 
 object. The nearer we approach the town the country im- 
 proves, and is conliderably diverfified with wood and culti- 
 vated fields. 
 
 The rocks which occur in this tract are all of fecondary 
 formation ; which is commonly the cafe where the country is 
 low and flat. As our journey was- rapid, I can only fay, in 
 general, that the ftrata are, fandflone, limeftone, bafalt, wac- 
 ken, mandelflein, coal, with its accompanying fhiftofe clay, 
 &c.. and iron-flone. 
 
 The fandftone is generally ufed for the purpofes of build- 
 ing j butj from different quarries it is more or lefs durable* 
 This fact leads us to remark, that chemical trials, combined 
 with correct mineralogical obfervations, might, in many in- 
 fiances, enable us to determine, with fome certainty, as to the 
 
 probable 
 
FROM EDINBURGH TO 
 
 probable durability of (tones employed in building. Indeed, 
 thofe who have been long in the habit of analyfiag and exa- 
 mining fuch ftones, can, even by their appearance, judge of 
 their probable durability * : a circumflance fufficient to encou- 
 rage us to purfue a mode of inveiligation which has hitherto 
 engaged little attention. The limefbone which occurs in this 
 diftri(5l varies confiderably in its appearance : but we had not 
 an opportunity of obferving it particularly. It is quarried in 
 feveral places to a coniiderable extent, and then burnt, and 
 ufed for manure, and for building. It is burnt for thefe pur- 
 pofes in the common draw-kiln, which is ill conftrucSled, as 
 there is not only a great wafte of heat, but, by expofure to all 
 the variations of the weather, the burning is rendered preca- 
 rious and uncertain. My father remedied thefe defects in a 
 kiln which he built eight years ago, and which he flill conti- 
 
 A 2 mies 
 
 * We have a curious inftance of this related of the late Mr Bayen ; A gen- 
 tleman who had paid much attention to the genera of marble and ferpentine. 
 Walking one day in the Place de la Revolution, at Paris, with his friend and col- 
 league Deyeux, he pointed out to him feveral of the marble pillars, which, he 
 faid, notwithftanding their prefent folid appearance, would decay in a fhort time, 
 and in the particular places he mentioned. Accordingly, a year had fcarcely elapfed 
 when his predi&ion was fulfilled : many of the pillars began to decay, and even 
 considerable hollows were quickly formed in fome of them drtnales de Chymtc* 
 
<f FROM EDINBURGH TO AILSA. 
 
 nues to ufe as economical, both with regard to time and fuel. 
 It differs from the common kiln by having the body or cylin- 
 drical part very deep, and covered with a dome, which is con- 
 necfled with a vent that has a damping plate, fo as to allow a 
 very advantageous management of the heat. Befides, it has 
 another very conliderable advantage over the common kilrt^ 
 that is, it can be eredled in a town without detriment to the 
 neighbourhood, as all the noxious matter is carried away by 
 means of the chimney f . 
 
 * 
 
 The country in the neighbourhood of Glafgow, as far as I 
 had an opportunity of examining, is compofed, ift, of bafalt, 
 
 which 
 
 f A vulgar prejudice has long prevailed, that the noxious matter of limeftone 
 is more dangerous than that of common coal ; and the many horrid ftories on re- 
 cord, of fudden deaths in the neighbourhood of lime-kilns, ftill continue the de- 
 lufion with the ignorant. The modern chemical difcoveries have fhown, that 
 common coal, bulk for bulk, furnimes more of the noxious matter (carbonic acid 
 and carbonated hydrogen) than limeftone : therefore, the noxious effects of the 
 common kiln does not depend on any peculiar malignity of the vapour which if- 
 fues from the flone, but upoa the conftruclion of the furnace. 
 
 The patriotic Count Rumford has lately propofed a new plan of a limc-ki!n> 
 which certainly deferves to be tried : To us it appears objectionable, not only 
 from the clofe attendance that the fires require, but alfo that a confiderable por- 
 tion of heat is loft by its being open at top, See Rurnfcrd's E/ays* 
 
TROM EDINBURGH TO AILSA. 5 
 
 which has fometimes in-lying cryflals of felfpar, bafaltic horn- 
 blende, augit, leucit, mica, and a few interfperfed parti- 
 cles of quartz ; 2. bafalt porphyry ; 3. grunftein ; 4. lime- 
 flone. The fhort time I could afford to fpend in Glafgow, and 
 my anxiety to get forward to the Iflands, prevented me from 
 examining the relation of the different flrata to each other ; 
 which, however, I the lefs regret, as that circumflance is but 
 flightly connected with my prefent object. 
 
 ProfefTor Faujas de St. Fond has given us a fhort account of 
 the mineralogy of the environs of Glafgow ; but his defcrip- 
 tions are unluckily obfcured by a rigid adherence to a theory 
 which has no foundation in nature. He confiders all the rocks 
 we have now mentioned, as lavas ; and thofe he denominates 
 bafaltic, porphyritic, and granitic lavas. I do not hefitate a 
 moment in faying, that, in my opinion, there is not in all Scot- 
 land the veflige of a volcano. I do not reft this afTertion upon 
 my own authority, (for that would be prefumptuous ;) but upon 
 that of Dr. Walker, who has examined more of the mineralogy 
 of Scotland than any man now living, and whofe collection of 
 Scotch foflils is the largeft that has ever been made. Befides, 
 it wars with every principle of fyftematic clarification, to ar- 
 range and denominate foflils from any theory we may adopt as 
 to their formation* 
 
 We 
 
6 FROM EDINBURGH TO AILSA. 
 
 We now purfued our journey from Glafgow to Greenock, 
 down the river Clyde : a voyage which prefents the traveller 
 with many fcenes of uncommon beauty. At Glafgow the ri- 
 ver is narrow, with low formal banks ; but as we approach 
 Dumbarton, the river becomes wider, the country more beau- 
 tiful, and the fcene is foon rendered interefling by the appear- 
 ance of the fingular rock of Dumbarton. From this the moun- 
 tains of Cowal extend, along the north fide of the river, to Rof- 
 neath ; forming a fine contrafl of Alpine wildnefs, with the 
 comparatively low green hills which reach to Greenock upon the 
 fouth fide of the river. Tlxe ftrata between Glafgow and Gree- 
 nock, upon the fouth bank of the river, are, fandflone, lime- 
 flone, bafalt, and wacken. Thofe of the north bank, to the 
 town of Dumbarton, continue to be nearly of fimilar rock ; 
 forming, in this rout, fome confiderable heights, particularly 
 about Frifky Hall, where the rocks have a fine terraced appear- 
 ance. Immediately below the houfe of Frifky, at the porter's 
 lodge, we obferved a final! quarry of wacken, which is now 
 celebrated as affording fine fpecimens of prehnite. The town 
 of Dumbarton is fituated in a plain of confiderable extent ; and 
 the rock upon which the caflle is built, rifes from it in a fimi- 
 lar manner with Arthur's Seat, near Edinburgh, but is much 
 more flriking, from the great flatnefs of the country. It is 
 compofed of black bafalt ; but, upon the fide facing the town, 
 
 we 
 
FROM EDINBURGH TO AILSA. 7 
 
 we obferved a bafalt tuffcovered by fandflone. ProfefTor St. Fond 
 remarks that this rock is formed of a black bafaltic lava ; but 
 upon the lower part, facing the town, there is to be obferved 
 a current of muddy lava, having, intermixed, fragments of ba- 
 falt, more or lefs altered. At different periods the rock of 
 Dumbarton has been of confiderable confequence, on account 
 of the flrong fortrefs which is built upon it. When Mary, 
 the unfortunate and lovely Queen of Scotland, was imprifoned 
 in England, and her kingdom wrefted from her, the folitary 
 rock of Dumbarton held out againft every attempt to take it j 
 and was the only place in the kingdom that dared to acknow- 
 kdge her authority. 
 
 If we glance over the country as it extends towards Lochlo- 
 mond, we obferve it rifing gradually until the profpecl: is 
 bounded by vaft mountains, marking, by their height and 
 ihape, a change in the nature of the flrata, and forming the 
 grand entrance into the Highlands upon this fide of Scotland. 
 If we examine the country more particularly, we find our con- 
 jecture right ; for at Lufs, upon the banks of this beautiful 
 loch, ftrata of micaceous fliiftus, and other primitive rocks, 
 make their appearance. Thefe flrata extend towards the Clyde,, 
 and form a confiderable part of its north bank, from Dumbar- 
 ton to Rofneath, a fmall village oppofhe to Greenock. 
 
 Greenock, 
 
8 FROM EDINBURGH TO AILSA. 
 
 Greenock, a populous and flourifhing town, is fituated upon 
 the fide of the river, at the bottom of hills of confiderable 
 height ; and remarkable for the quantity of rain which falls 
 during the year, which is faid to be more than in .any other 
 part of Scotland. The ftrata in the immediate vicinity of the 
 town are, bafalt, wacken, fandflone, limeftone : and in fome 
 places the fandflone is to be obferved traverfed with bafaltic 
 veins ; and the wacken, befides zeolite, contains a curious foml 
 nearly allied to leucit. 
 
 From Greenock our farther progrefs down the Clyde was 
 more interefting, from the grandeur and variety of the objects 
 which now occupied our attention. After pafling the Gouroch 
 lighthoufe, we obferved the beautiful ifland of Bute, with the 
 neighbouring and Cumbray ifles flretching acrofs the view ; 
 and, farther diflant, the wild mountains of Arran appeared 
 over the low part of Bute towering among the clouds. The 
 hills upon the oppofite bank of the river are flrikingly con- 
 trailed. Upon the Cowal more the country rifes into confi- 
 derable hills of micaceous fhiflus, which are partly heath-clad, 
 and join with the bare and flerile mountains that extend from 
 this more through Argylefhire. Upon the oppofite bank of the 
 river the country is much lower ; there are no deep hills upon 
 thefhore; and the (trata^ which are horizontal, are, red and 
 
 white 
 
FROM EDINBURGH TO AILSA. 
 
 white-coloured argillaceous fandftone, fandftone breccia, bafalt, 
 and frequently bafaltic veins traverfe both thefe flrata. The 
 breccia, as is often the cafe with this kind of rock when it oc- 
 curs upon the fea-fhore, forms beautifully wooded cliffs, which 
 extend to the fweetly-retired village of the Largs. Thefe fe- 
 condary flrata extend from the Largs to Saltcoats, and from 
 thence far through Ayrfhire ; while the primary rocks, on the 
 oppbfite bank of the river, appear to extend to the Mull of 
 Cantyre. In a few hours after pafling the Cumbray ifles, and 
 the majeflic ifland of Arran, we landed upon the great rock 
 which is called 
 
 THE CRAIG OF AILSA. 
 
 This flupendous rock is faid to be 400 feet high, and is 
 about two miles in circumference. It is fomewhat of a conical 
 fhape, and very precipitous on all fides : the only landing- 
 place being on the N. E. where there is a fmall beach, formed 
 by the fragments which have fallen from the neighbouring 
 rocks. It is much lower now than it was formerly ; as is 
 evinced, not only by the numerous fragments lying on the 
 beach, but alfo more fully by the nature of the bottom near 
 it, which, according to the moft accurate foundings, is gra- 
 velly to a considerable diflance. 
 
 B After 
 
jO FROM EDINBURGH TO AlLSA. 
 
 After having walked around part of it, and afcerided near to 
 the fummit, I was forced to return, as the captain of the veflel 
 was anxious to proceed to Arran. On this account, I was pre- 
 sented from examining it fo accurately as could have been 
 wifhed. This glance, however, was fufficient to fatisfy me as 
 to the general nature of the rock of which it was compofed. 
 
 The greater part feems to be formed of different fpecies of 
 very compact fienite ; which, particularly on the eail fide, pre- 
 fents imrnenfe groupes of columns, fimilar in appearance to 
 the bafaltic columns that occur fo often in different parts of 
 Scotland. In afcending towards the fuminit, and a little be- 
 low the folitary ruin of a cattle, I obferved two confiderable 
 bafaltic veins travelling the fienite, ' 
 
 CHAP. 
 
CHAP. II. 
 
 Defcription of the FOSSILS mentioned in the preceding Chapter. 
 
 PREHNITE FriJky-Hall. 
 
 SlLEX PREHNITES, Wem. JLtLB Z EOLITH^ Efthlier. 
 
 Dr. Walker. 
 
 It is either in flat mafTes, cellular, or botroidal, or partly af- 
 fuming a mammillary figure ; is generally radiated and com- 
 pofed of fmall prifmatic cryftals fometimes fo fmall, and fo 
 near to each other, as to aflume, in fome degree, a compact 
 texture, almoft resembling chalcedony. 
 
 Colour. Varies, from apple green, to yellowifh green, pale yel- 
 low, and white ; but, when affected by the weather, it ac- 
 quires an ochry, or opaque white colour. 
 
 Lujlre. The external luftre little gkncing* ; internal is pearly. 
 
 Tranfparency. It is femi-tranfparent ; but, when acted upon by 
 the weather, it becomes confiderably opaque, and much 
 refembles certain fpecies of fulphat of barytes. 
 
 Hardnefs. Gives fparks with fteel ; takes a pretty good polifh. 
 
 B 2 Frafturc. 
 
 * Wtnlg gtanzend. Germ. 
 
FROM EDINBURGH TO AILSA, 
 
 Fratfure. The fracture in the direction of the folise appears fo- 
 liated, but acrofs the radii approaches to the conchoidal. 
 
 Fufibillty. Dr. Hope melted it, and, by flow cooling, had again 
 a pretty regular cryflalline texture. 
 
 It is contained in a fpecies of wacken, which, by its degree 
 f induration, appears pamng to the ftate of bafalt. It is fre- 
 quently accompanied by calcareous fpar. Another fubftance is 
 often found with it, which is probably of the nature of zeolite. 
 
 It is formed of long prifmatic radii, which have the follow- 
 ing character. 
 
 Colour. White. 
 
 Luftre. Pearly. 
 
 Tran/parency. Nearly tranfparent. 
 
 Hardnefs. Difficultly fcratched with a knife. 
 
 OBSERVATIONS. 
 
 The Prehnite has received many denominations, by different 
 
 mineralogifts : thus it has been called green felfpar, apple-green 
 
 quartz, filiceous zeolith, cape-chryfolith, emerald, prafe, and 
 
 cryfoprafe: a ftriking proof of the imperfection of mine- 
 
 ralogical nomenclature. The juflly-celebrated Mr. Werner, to 
 
 whom 
 
FROM EDINBURGH TO AILSA. 
 
 whom we owe fo much of our moft accurate information, 
 names it Prehnite, after Colonel Prehn, a Dutch officer, who 
 found it at the Cape of Good Hope, and firffc brought it to Eu- 
 rope. Since its difcovery at the Cape of Good Hope, it has 
 alfo been found in Dauphine ; and Dr. Grofcke of Mittau firft 
 difcovered it at Frifky-Hall. This is not the only place in 
 Scotland where this beautiful foffil is found ; for I have ob- 
 ferved it m the caftle rock and Arthur's Seat at Edinburgh, 
 and we mail afterwards notice it in the ifland of Mull. 
 
 LEUCTT GreenocL 
 
 SARCITE, Dr. Townfon's Tracts in natural hiflory. BORAX 
 MARGODES, Lin. ? 
 
 This foflil is of a reddifh-brown colour, and generally cryftal- 
 lifed in the form of a 24 edron : it is alfo, in fome inflances, 
 amorphous, with an earthy fracture *.. 
 
 It has always occurred opaque, and of fuch a hardnefs as to 
 yield with difficulty to the knife. 
 
 With the blow-pipe it lofes its colour, and melts like felfpar. 
 
 It 
 
 * Dr. Hope has in his pofleflion a very fine fpecimen of this foflil, which he. 
 found at the Calton Hill. Dr. Townfon has figured it in his Trafts, 
 
j^ FROM EDINBURGH TO AILSA. 
 
 It is found in the cavities of wacken, and fometimes im- 
 bedded in calcareous fpar. 
 
 Abbe Huay remarks that this foflll is considered as a zeo- 
 lite *f ; and La Metherie, who had examined fpecimens of a fi- 
 milar foflil from the Calton-Hill at Edinburgh, remarks, " On 
 " trouve, au mont Calton-Hill, proche d'Edimbourg, un cri- 
 " ftal a vingt-quatre facettes trapezoidales, comme celui-ci 
 " II eft rougeatre, poreux, terne, comme de la brique. On 
 " croit qu'il doit entrer dans la zeolite leucitique J." Dr. 
 Townfon, in his lately-publifhed Traces in natural hiftory, 
 coniiders it as a new genus, and names it Sarcite : this, how- 
 ever, cannot be admitted, until the foflil {hall be regularly ana- 
 lyfed. Mr. Camara of Lifbpn, a moft intelligent mineralogift, 
 informed me, that he had frequently met with this foflil in 
 other countries, but always confidered it as nearly allied to 
 leucit. It appears, then, that it mould flill be reckoned of the 
 nature of leucit, until it mall be more particularly examined 
 in the way of chemical analyfis. 
 
 SIENITE- 
 
 Annales de Chyraie. 
 
 Th orie de la Tcrrc, torn, 2<fo, p. 
 
PROM EDINBURGH TO AILSA. Ij> 
 
 SIENITE Craig of Ailfa. 
 CALOMACHVS, Dr. Walker's ClafTes FofGlium. 
 
 So far as I can determine at prefent, this rock appears to be 
 a very compact fpecies of fienite, in which the felfpar is the 
 moft prevalent ingredient. Sometimes the felfpar feems pafling 
 to the ftate of earthy felfpar ; and then it forms a bafis in 
 which we obferve red or white-coloured cryftals of common 
 felfpar and hornblende, and particles of quartz ; thus forming 
 a fpecies of fienitic porphyry. 
 
A R R A N. 
 
 CHAP. III. 
 
 Size and Situation of the I/land. Cliff's , Mountains, Surface, 
 Brodick Bay, and its Environs ; comprehending Cory-Gills, Glen 
 Cloy, Gkn-Sbirreg, Goatfield, and Glen-Rofa. 
 
 JL HIS ifland -is about thirty-two miles long and twelve 
 broad ; fituated in the mouth of the Frith of Clyde, about 
 eight miles from Bute, and lixteen from Saltcoats in Ayrfhire. 
 Its fhape is irregular, but not fo much fo as many of the Weft- 
 ern Iflands which are expofed to the Atlantic Ocean. Here, the 
 vicinity of the Scottifh and Irifh fhores prevents any great de- 
 ftruc~lion of land ; as is evident from the lownefs of the cliffs 
 round the ifland, which have not the precipitous, rugged and 
 bold afpecl of many of the Weftern Iflands. 
 
 CLIFFS. The cliffs are feldom above two hundred feet high ; 
 are generally precipitous : having frequently, however, an in- 
 tervening 
 
THK 
 
 &LAX1) cw AKRAN; 
 
 i'cl For ai 
 
 MINKRAMMJY 
 
 '111, milt f/iirt/it h/iit/i/ 
 
A R R A N, 17 
 
 tervening bank between the cliff and die fea, formed by the 
 definition of the rocks, which are either of fandftone or mi- 
 caceous fhiflus. Confiderable fandy beaches frequently occur, 
 formed of the debris of granite, fandftone, and micaceous mi- 
 tus ; and fometimes we remark a confiderable extent of coafl 
 covered with enormous mafTes, which have been torn away by 
 torrents, or feparated from the neighbouring rocks by the vaft 
 expanfive power of froft. 
 
 MOUNTAINS. No regular ridge of mountains is to be ob- 
 ferved : thefe being either in the form of groups, as Goatfield 
 and the adjacent mountains, which prefent aftonimingly grand 
 peaked fummits ; or irregular, forming round-backed hills, as 
 thofe towards the fouth part of the ifland. 
 
 SURFACE. The land is In general very high, particularly to- 
 wards the north end, where the wonderful group compofed of 
 Goatfield, Caime-na-callich, &c. prefent mountains near 3000 
 feet high. Here Nature exhibits to the aftoniihed eye the mod 
 terrific and fublime fcenery ; to convey even a faint idea of 
 which would require an able pen. The fouthern parts are 
 lower ; and in place of the bare rocky appearance of the north, 
 we have heath-covered hills, and a considerable portion of cul- 
 tivated land. 
 
 Q The 
 
1 8 A R R A N. 
 
 The ifland is divided into two parifhes, Kilbride and Kil- 
 mory, belonging to three proprietors ; the Duke of Hamilton, 
 Marquis of Bute, and John Fullerton, Efq. of Kilmichael ; and 
 yields about 5000 1. of yearly rent. This indeed might be 
 much increafed, were proper methods of cultivation followed ; 
 and were long leafes and larger farms properly granted, more 
 happinefs, induftry and wealth would be the natural con- 
 fequence. 
 
 In defcribing the ifland particularly, I mall begin with 
 
 BRODICK BAY, fituated on the earl fide. This beautiful bay 
 is bounded, on the S. by the hills of Cory-gills ; on the W. by 
 the vales of Glencloy and Glenfliirreg, and, on the N. the tre- 
 mendous Goatfield forms a lofty boundary. It is of an irregular 
 fhape ; about five miles long, and four broad ; having about 
 five fathoms water, with good anchorage ground : but it is on- 
 ly in moderate weather that vefTels can ride in fafety. From 
 this bay paflage-boats go to Saltcoats, about fixteen or eighteen 
 miles diftant, which renders this the principal thorough-fare 
 in the ifland ; fo that the population is confiderable. Many vi- 
 fitors come from the mainland, during t}ie fummer months, 
 to enjoy the free air, and admire the wonderful fcenery of this 
 interefting ifland ; but the want of a good inn is much to be 
 
 regretted. 
 
A R R A N. . 19 
 
 regretted. On the north fide of the bay (lands Brodick Caftle, 
 an old ruinous building, inhabited occafionally during part of 
 the furnmer by the Duke of Hamilton. It is lituated upon 
 the fide of Goatfield, commanding a moil extenfive and de- 
 lightful profpe<5l ; and might eafily be made a beautiful feat. 
 About two miles diflant, in Glencloy, is fituated the pleafant 
 feat of the worthy and mofl hofpitable family of Fullerton, of 
 Kilmichael, who have now refided in the ifland upwards of 
 700 years. 
 
 Mineralogy. The mineral hiflory of this part of the ifland 
 is, in many refpedls, interefting ; not only on account of the 
 variety of foffils which it affords, but alfo in prefenting to us, 
 in a iliort fpace, a reprefentation of the flruclure and materials 
 of nearly the whole ifland. On this account I fhall be minute 
 in my defcription ; as I may have occafion to refer to this par- 
 ticular part, when defcribing the other quarters of the ifland. 
 
 The fouth fide of the bay is low immediately upon the more : 
 it however rifes gradually ; forming the hills in the neighbour- 
 hood of Cory-gills, and, towards the fea, cliffs of confiderable 
 height, almoft entirely compofed of fandflone *. This fand- 
 
 C 2 flone 
 
 :> M. de C. LafTone has obferved, that the furface of a fandftone, which had 
 
 the 
 
jo A R R A K. 
 
 itone is pretty compact, of a reddifh colour, much refembling 
 that found in Shetland ; and is here and there alternated with 
 flrata of breccia, compofecl of rounded fragments of quartz, 
 with fragments of fandflone, of various fizes and fhapes ; and 
 both thefe flrata run at an angle of from 10 to 15. In ma- 
 ny places there are very confiderable veins of bafalt, or what 
 have been called Whin-dykes f> crofting die fandftone in va- 
 rious 
 
 the year before been left uncovered, was invefted with a filiceous cruft, nearly as 
 hard as agate : the particles of which it was formed muft therefore have been 
 eonveyed and depofited by water. Mem. Par. 1774. Kiribati's Geological Ejjays t 
 p. 112. This is a proof of the folubility of filiceous earth in water : a facl: denied 
 by the Plutonifts. It is more demonflrably confirmed by the following faft, from 
 Mr. Kirwan's Geological Eflays, p. 140. ' About the year 1760, the Empeior 
 * of Germany being defirous to know the length of time neceffary to complete a 
 " petrifaction, obtained leave from the Sultan to take up and examine one of the 
 " timbers of Trajan's bridge over the Danube at Belgrade. It was found to have 
 < { been converted into agate to the depth only of half an inch ; the inner parts 
 " were {lightly petrified, and the central flill wood." 
 
 f The term Whinfton^ like many other popular denominations, does not 
 convey a diftinft idea of any particular genus of foffils ; but is ufed by the inha. 
 bitants of Scotland, and of the north of England, to exp refs thofe foflits which, 
 are of trap formation* Mineralogifts, in many inftances, appear to have ufed it 
 in a very vague manner : thus fome defcribe trap, others bafalt j and not unfre- 
 quently wacken, greenftone and indurated clay ha^ve been arranged under this 
 
 name, 
 
A R R A K 2 ! 
 
 rious directions. Some may be obferved rifmg from the fea, 
 and penetrating the fandflone. In other places, where the fu- 
 perincumbent fandftone has been completely carried away, 
 veins can be remarked running, with little variation in diame- 
 ter or direction, for nearly a mile. Thefe veins are not only 
 to be obferved upon the fea more, but can be traced running, 
 in various directions, and of different diameters, through the 
 fandftone and other rocks in the interior of the ifland, as we 
 lhall afterwards clearly demonftrate. In afcending the hill to- 
 wards Cory-gills, a very confiderable vein of dark leek-green 
 ^itchftone makes its appearance, running from the cliffs upon 
 the fhore, thro' the fandftone, to the Lamlam road, where we 
 foon lofe it among the fandftone in the neighbouring hills. 
 This vein is of various breadths ; in fome places, as at the 
 Lamlaih road, being about eight feet. It does not appear to 
 have altered the fandftone, where it is in contact with it ; but, 
 in fome parts of the vein, the pitchftone, as it approaches the 
 fandftone, lofes much of its luftre, and, in fracture and hard- 
 nefs, approaches to the nature of bafalt. 
 
 The 
 
 name. It is much to be wiflied that it could be entirely laid afide ; particularly 
 when we perceive that the great Werner has framed fatisfaftory characters for 
 thefe different rocks, 
 
22 A R R A K. 
 
 The appearence of pitchftone in the form of veins, and in 
 fecondary flrata, has not as yet been obferved by other mi- 
 neralogifts. Mr. Werner, from his own extenfive knowledge, 
 and the accumrmilated information of his numerous pupils, is 
 of opinion, that pitchftone is always difpofed in ftrata, and 
 entirely confined to primitive mountains. ^The late Abbe 
 Spallanzani defcribes feveral veins of pitchftone lava that he 
 obferved in the Euganean mountains ; but it is difficult to de- 
 termine with certainty whether this be the true pitchftone *. 
 
 Higher up, above the houfes of Cory-gills, I obferved 
 a /number of columns which are compofed of clay - por- 
 phyry. Thefe pillars are in various directions ; fome are 
 perpendicular to the horizon ; others more or lefs inclined ; 
 and I obferved, farther up, that they are quite horizontal. 
 They are in the form of four or fix-fided columns, from fix to 
 ten feet long, and two or three feet in diameter, having a whi- 
 tifh cruft from decompofition. They are not jointed ; nor is 
 there any appearance of balls, or what- the volcanifts call vol- 
 canic bombs. I endeavoured to difcover the pofition of the por- 
 phyry with regard to the fandftone, but could not detect them 
 in contacl with each other ; yet, from the nature of the rocks 
 
 all 
 
 * Spallanzani's Travels in the Two Sicilies, vol. 3^, p. 251, &c. 
 
A R R A N. 23 
 
 all around, I am inclined to believe that it refts on the fand- 
 flone. In defcending from this porphyry hill towards Lam- 
 lafli, the fandftone again makes its appearance, but is foon loft ; 
 being covered with a rock which is principally compofed of 
 dark -green coloured hornblende, with a little felfpar and 
 quartz, and anfwers nearly to the greenftone of the Germans. 
 This greenftone forms the fummits of feveral hills in the 
 neighbourhood, and may be remarked running towards the 
 fea, forming high cliffs. In one place I obferved a great 
 body of green-coloured pitchftone, which runs quite in an 
 oppolite direction to the vein I obferved crofling the Lam- 
 lafh road : in fhort, it appears to be ftratified, and to run 
 immediately below the greenftone. About twenty yards lower, 
 another mafs occurs, about ten or twelve feet thick; and 
 which, fo far as I could determine, appears to form a ftratum, 
 running between the fandftone and greenftone. I was inform- 
 ed that this mafs of pitchftone had been traced to the face of a 
 high cliff upon the fea-fhore, where it is faid to lie upon fand- 
 ftone, which alfo covers it ; and that it was there alfo fplit into 
 columns, like bafalt. 
 
 Having now mentioned the pofition of the veins and ftrata 
 upon the fouth fide j I lhall return to the fea-fhore, where we 
 
 obfervc 
 
34. A R R A N, 
 
 obferve the bay rifing towards the weft, forming the one fide 
 of Glencloy. 
 
 GLEN-CLOY. This glen is nearly three miles long, and half 
 a mile broad ; open towards the eaft, but bounded on the other 
 fides by high hills. At the top, or weft part, of the glen, the 
 hills are higheft, forming a very romantic groupe of rocks. 
 The north and fouth fides, which are of confiderable height, 
 become gradually lower as they approach the fea, where they 
 form part of Brodick Bay. The bottom of the glen rifes gently 
 from the fea, forming a fmall angle with the hills that bound 
 it. Immediately under the peat mofs, or heather, we difcover 
 boulder ftones, which form a thick bed, from three to thirty 
 feet thick ; and in other places they are collected together in 
 heaps, being thrown into this form by the force of water. 
 Thefe bowlder ftones are not of very confiderable fize, and va- 
 ry but little in that refpecl at the top or bottom of the glen ; 
 which mews that the greater part of them have not received 
 their rounded form by attrition in the water of the glen, but 
 are derived from decompofed breccia. They confift of granite, 
 porphyry, fienite, breccia and fandftone, which are all to be 
 obferved in the neighbouring hills. Through the glen runs 
 Glencloy burn, formed by the fpringa and rains from the 
 
 the 
 
A R R A N. 2 
 
 the hills : it is narrow, but, during violent ftorms, it overflows a 
 confiderable part of the glen, and has thus laid bare the rocks, 
 and fhows us, in a fatisfaclory manner, the nature of the fub- 
 jacent ftrata. The bottom of the glen is compofed of the com- 
 mon red-coloured argillaceous fandftone, and here and there 
 are ftrata of breccia ; and both are traverfed with veins of ba- 
 falt, which run in very various directions, and are from three 
 to twelve feet in breadth. Thefe veins, in their paflage thro' . 
 the ftrata, (to ufe the Huttonian language,) do not appear to 
 have occafioned in them any alteration with regard to hard- 
 nefs : on the contrary, we often find a fpecies of femindurated 
 clay interpofed between the fandftone and bafalt, thus form- 
 ing a ftratified vein. 
 
 Reufs, the celebrated German geologift, in his mineralogi- 
 cal hiftory of Bohemia, defcribes two ftratified veins which he 
 obferved in the Bunzlauer circle. As it is of importance to 
 turn the attention of the young mineralogift to thofe curious,, 
 and, I believe, rare, appearances, I will mortly mention the na- 
 ture of thofe veins obferved by Reufs. One of the veins tra- 
 verfes argillaceous fandftone, and is about a fathom wide ; its 
 fides are of common argillaceous ironftone, about five or fix 
 inches wide : to this fucceeds a layer of wacken-clay, about 
 half a foot wide ; then a thin layer of wacken, or rather a rock 
 
 D inter- 
 
26 A R R A N, 
 
 intermediate between wacken-clay and wacken ; laftly, the mid- 
 dle of the vein is bafalt. The other vein has argillaceous iron- 
 ftone for thefaalband or fides, but the middle is wacken clay. 
 The fandflone, as it comes in contact with the vein, is remark- 
 ably great-grained and iron-fhort *. 
 
 The hills on the north and fouth fides of the glen are of the 
 fame height ; and the pente of the hills appears to correfpond 
 pretty nearly with the elevation of the flrata. The hills on 
 the fouth fide are formed of fandilone and breccia, which, to- 
 wards the upper end, form very lofty precipices. Many veins 
 of bafalt traverfe the fandilone, and loofe nodules of brownifh- 
 black and black pitchflone lie fcattered about here and there. 
 On the north fide of the glen, near to Brodick wood, a confi- 
 derable body of dark leek-green coloured pitchftone makes its 
 appearance ; but it is fo much covered with grafs, that it is diffi- 
 cult to fay whether it forms a vein or a flratum. It is well wor- 
 thy the attention of thofe who may vifit Arran, to endeavour to 
 determine this point. In afcending the hills upon this fide, after 
 gaining a confiderable height, the fandftone difappears, when 
 
 a clay 
 
 ' Mineralogifche Geographic von Bohmen, von Franz Ambros Reufs, 
 vol. 2. 
 
A R R A N. 27 
 
 a clay-porphyry is to be obferved ; and upon the brow of the 
 hill, where the rains, &c. have broken down the porphyry, fe- 
 veral curious phenomena appear. In the firft place, I obferved 
 the porphyry in columns fimilar to thofe at Corygills : next, 
 the bafaltic veins running in different directions through it. 
 One great vein is to be obferved rifing from the neighbouring 
 fandflone, penetrating the clay-porphyry ; and, as it rifes up- 
 wards, getting a considerable curve, when it branches : one 
 branch rifes to the top of the hill ; the other runs but for a 
 ihort way into the porphyry, in the form of a wedge. Near 
 to the fame place a curious Jlratified vein makes its appearance, 
 running in an almoft oppofite direction to that we have 
 juft mentioned, and terminating in a wedge-like form. On 
 the upper fide it is formed of fandflone breccia ; the lower is 
 hard filiceous fandflone ; but the middle is bafalt. The wefl 
 or upper end of the glen is formed of fandflone pretty much 
 traverfed with veins of bafalt, which are more or lefs in- 
 clined, and of various diameters. Befides this fandflone, we 
 obferve lofty precipices of fienite, which form ftrata elevated 
 at an angle of about 30. This rock is not only very much 
 varied in the nature of its conflituent parts, but alfo in the de- 
 gree of intimacy of combination, which renders it very diffi- 
 cult to diflinguifh its different fpecies. It is alfo traverfed with 
 
 D 2 veins 
 
..S A R a A N. 
 
 veins of bafalt, but not fo much fo as the fandftone *. It- 
 forms the higher part of feveral of the hills betwixt the top of 
 this glen and the Shifkin, and is alt along traverfed with ba- 
 faltic reins. 
 
 It appears, from the defcription that has been now given* 
 that the fandftone forms by far the greateft part of the 
 glen ; the next in proportion is the porphyry, and laflly the 
 fienite, 
 
 The 
 
 *' Dr. Hutton, in his fpeculations upon the theory of the earth, remarks, 
 " k If it be by means of heat and fufion that ftrata have been confolidated, then, 
 " in proportion to the degree of confolidation they have undergone from their, 
 " original ftate, they fhould, cateris paribus, abound with more feparations in the 
 mafs. But the conclufi^m is found confiftent with appearances. A ftratum of 
 ''fandftone does not abound fo much with Gutters and veins as a fimilar ftratum 
 " of marble, or even a fimilar ftratum of fandftone that is more confolidated : 
 ** they are in general interfered with veins and cutters ; and in proportion as 
 " ftrata are deep in their perpendicular feftion, the veins are wide, and placed at 
 " greater diftances." This does not appear to be confiftent with the faft ; for it 
 is to be obferved, in Arran, that the fandftone contains more veins than the fienite, 
 which laft is harder than any fandftone in the ifland ; and we obferve that the.. 
 fienite contains a greater number of veins than the granite, although it be fofter 
 and lefs compact. 
 
A 31 R A N. 29, 
 
 The determination of the relative pofition of flrata and veins 
 is the great object of the geologift, and without it his labours 
 will be of comparatively little value. It is, no doubt, of im- 
 portance to know that a country is compofed of particular 
 kinds of rock : yet this will be very unfatisfactory, if we know 
 not whether thefe rocks be primary or fecondary, how they 
 lie with regard to each other, and, confequently, if they be fa- 
 vourable for the appearance of metallic veins, coal, &c. Ma- 
 ny travellers, as my friend M. Camara de Bethencourt has ob- 
 ferved f, fatisfy themfelves, in their geological obfervations, by 
 following a very fuperficial and abfurd mode of inveftigation. 
 Thus, fome are contented to fit in their carriage and view the 
 rocks as they pafs along ; others, with more apparent curiofity, 
 examine the debris at the bottom of the hills, and, by means 
 of their telefcopes, determine the nature of the higheft moun- 
 tain. It is plain that thefe practices muft be very detrimental 
 to the advancement of true geological knowledge : they are the 
 more fo, when we conlider, that the greateft labour and afli- 
 duity is often employed in vain to delineate the true geological 
 character of fome parts of a country. In the courfe of my li- 
 mited travels I have experienced the truth of this obfervation ; 
 for, after having fpent many days in endeavouring to deter- 
 mine 
 
 f Neues Bergmannifches Journal. B. i. 272, 
 
30 A R R A N. 
 
 mine the relative poiition of certain ftrata to each other, I have 
 been obliged to reft fatisfied with a general conclufion drawn 
 from the nature of the furrounding rocks. Thus, in Glencloy, 
 I could not difcover the porphyry and fandftone at their junc- 
 tion ; yet, if we confider that the porphyry, both here and at 
 Corygills, is found upon the fummit of 'fandftone hills, and 
 that, in this place, we obferve the fame bafaltic vein apparently 
 traverfing the fandftone and porphyry, we may prefume that 
 they are of the fame formation, and that the porphyry covers 
 the. fandftone. We have more certainty with regard to the iie- 
 nite, which appears to be of an origin anterior to the fand- 
 ftone ; as is pretty well {hewn from the appearance of a brec- 
 cia that lies upon its furface, which had been interpofed be- 
 tween it and the fandftone, before the caufes which formed the 
 glen had removed the fandftone. 
 
 GLENSHIRREG. This glen is of considerable extent, bounded 
 upon one hand by Glencloy, and on the other by Glenrofa. 
 The hills towards the W. are not fo rugged as thofe at the 
 top of Glencloy, and both the bottom and fides are formed of 
 the common fandftone, much traverfed with veins of bafalt ; 
 but towards the S. W. we obferve a clay -porphyry, which 
 forms part of the rocks higher up than the fandftone, and is, 
 in facl, part of the mafs we obferved before in Glencloy. 
 
 GOAT FIELD. 
 
A R R A K. 31 
 
 GOATFIELD. This mountain, according to ProfefTor Play fair, 
 is about 2945 feet above the level of the fea, and is reckoned 
 
 the nighefl in the ifland. It rifes pretty rapidly from the fouth 
 fide of Brodick Bay, until we arrive at the region where the mi- 
 caceous fhiftus difappears. At this height there is a kind of 
 irregular plain, from which the mountain rifes in the form of 
 an obtufe pyramid, and is very precipitous, being entirely 
 formed of granite. On the W. where it forms part of Glen- 
 rofa, it is extremely deep, which is owing in a great meafurc 
 to the want of micaceous fhiftus and fandftoue ; for, in general, 
 wherever thefe occur the declivity is lefs fudden.. On the eafl 
 fide the pente is more gradual ; marking, according to the fteep- 
 nefs, the prefence of granite, micaceous fhiftus, or fandflone. 
 It declines a little towards the N. but it rifes again, forming 
 one of the boundaries of the rude Glen-Sanicks : it alfo fopms- 
 the top of the bare, rugged and flerile Cory-Glen, and the top 
 of the, other two great hollows between the Cory-Glen and 
 Glen-Sanicks. 
 
 The lower part of Goatfield is compofed of the ufual red- 
 coloured fandftone, and is traverfed by veins of bafalt ; this 
 continues for feveral hundred feet up the mountain, when it at 
 laft difappears : the micaceous fhiftus rifes from under it, fe- 
 parated only by a ftratum of breccia, thus fhewing the relative 
 
 pofition 
 
0^ A R R A N. 
 
 pofition of the fandftone and micaceous miftus. The micace- 
 ous miftus continues until we arrive at the plain formerly 
 mentioned ; but the fide of the mountain, in fome places, is fo 
 covered with the debris of granite, micaceous miftus, &c. that 
 it is only by the appearance of the granite, in the neighbour- 
 hood of this plain, that we are aware of its exiftence, as the 
 afcent is hardly more fteep over the micaceous fhiftus than the 
 fandftone, which is not generally the cafe ; for we find, when 
 the ftrata are not covered with debris, that the fandftone is far 
 lefs fteep than the micaceous miftus, and this laft than granite. 
 Even in this way, we have a kind of general rule for judging 
 i)f the nature of mountainous ridges. If they be neaked, and 
 very precipitous, we may prefume that they are of granite ; 
 if they be lefs lofty, and not peaked, but ftill fomewhat ap- 
 proaching to the conical fhape, we may fuppofe them to be 
 compofed of micaceous fhiftus ; and, laftly, if we obferve thefe 
 fkirted by lower mountains, with a trifling pente, we may con- 
 clude that they are compofed of fandftone and limeftone. Al- 
 though thefe obfervations may hold true in general, yet they 
 will fometimes be found liable to confiderable variations : 
 thus we know that the fhape, and other appearances, of moun^ 
 tains compofed of fimilar rocks, are apt to be varied by feve- 
 ral circumftances, particularly by the horizontality or verti- 
 cality of the ftrata, their degree of compadnefs, and their 
 
 aptnefs 
 
A R R A N. 
 
 33 
 
 apthefs to be weathered. It would be an addition of fome 
 confequence, if we had a few general rules on this fubject. 
 SaufTure well remarks, " Les fignes qui peuvent donner 
 ; qualque indice de la nature des montagnes, a de grandes 
 " diftances, et au travers des plantes qui les couvrent, font en 
 " petit nombre, et meritent d'etre etudies et confacres par des 
 " termes propres." 
 
 The pyramidal part of the mountain has a very fterile and 
 wild afpeft ; being completely covered with loofe blocks of gra- 
 nite, and deftitute of all vegetation, excepting a few lichens, 
 which only add to its bleak appearance. Thefe blocks differ 
 very much in fize, fome being twenty feet long *, and gene- 
 rally of a quadrangular fhape ; and are fo heaped upon each 
 other, as to render the afcent very difficult. Having, however, 
 gained the fummit, we are well repaid for our labour by a moft 
 extenfive view of a wonderful diverfity of country. To the 
 
 E northward 
 
 * Dr. Walker has obferved immenfe folid mafles of granite in different parts 
 of the Highlands : but thefe are vaftly inferior to others that have been found in 
 other countries. About thirty miles from the Cape of Good Hope there is a 
 large mafs of granite, called the Pearl Diamond, which is about half a mile in 
 circumference, and 400 feet high. Ph'd. Tranf, 1778, p. 102, 
 
34 
 
 A R R A N. 
 
 northward we look down upon the peaked fummits and deep 
 glens in the neighbourhood of Goatfield, whofe arid and 
 reddifh appearance fuggefls to our minds the effects of a 
 dreadful conflagration. Beyond thefe, the iflhmus of Cantyre, 
 the ifland of Ifla, the lofty and dreary paps of Jura, the long 
 mountainous ridges of Argylefhire, and the far-diftant moun- 
 tains of Mull, which are faintly defcried, prefent a view rather 
 to be felt than defcribed. On the E. the well cultivated ifland 
 of Bute, the frith of Clyde, the Cumbray Iflands, backed with 
 the beautiful coafts of Renfrewfhire, form a mofl piclurefque 
 fcene. Towards the S. we have, below us, the lower part of 
 the ifland fpread out like a map, forming a fuigular appearance 
 of heath-covered mountains and cultivated glens : farther di- 
 tant, the charming coafts of Ayrfhire, the mores and moun- 
 tains of Galloway, aa far as the Mull, the ftupendous craig of 
 Ailfa, rifing from the bofom of the ocean, all delight the eye 
 and raviili the imagination. Laftly, on the W. the coaft of 
 Ireland,, from Fairhead to Belfaft Loch, concludes the amazing 
 view from this interefting height. 
 
 GLENROSA. This very finking glen, fituated upon the weft 
 
 ' 
 
 and fouth-weft fides of Goatfield, is about five miles long, and 
 half a mile broad, bounded by very high mountains. The 
 
 bottom. 
 
A R R A N. 35 
 
 bottom forms a confiderable angle with the fides, rifing gradu- 
 ally towards the upper, or north end, where it is formed part- 
 ly by the mountain called Keid-voe, and partly by Goatfield. 
 The mountains on the oppofite fides of the glen are of differ- 
 ent heights, (being far higher on the eafl than weft ;) but the 
 inclination of the oppofite flopes is the fame, being about 70. 
 At its entrance upon the fhore at Brodick Bay, it has Goatfield 
 on the north, and Glenfhirreg on the fouth. Oil the fouth 
 fide, the ftrata are common argillaceous fandftone, traverfed by 
 bafaltic veins ; but this continues only for a fliort way, as the 
 micaceous fhiftus foon makes its appearance. Upon the north 
 fide, a very little fandftone is to be obferved at the bottom of 
 the hill, the upper part being formed of micaceous fhiftus. 
 Amongft the debris of the micaceous fhiftus I obferved great 
 blocks of a rock, which is principally compofed of hornblende, 
 and now and then intermixed with quartz, and a fubftance that 
 appears to be the fame with the paliopetre of SaufTure. The 
 micaceous rocks upon both fides of the glen lie upon granite, 
 which foon prefents itfelf as we proceed up the glen, and 
 forms the mountains upon both fides to its further extre- 
 mity. This granite, which is fimilar to that of Goatfield, ap- 
 pears to be difperfed in great ftrata, that run N. and S. which 
 is nearly in the direction of the glen. If we view them from 
 
 E 2 the 
 
*6 A R R A K. 
 
 the bottom of the glen, they appear like great perpendicular 
 walls, which are fplit in many places into rhomboidal maiTes j 
 but if we clamber upwards for fome hundred feet, we at 
 length difcover the edges of the ftrata, extending for a great 
 way, and emerging here and there from above the loofe blocks 
 of granite, which have fallen from the mountains, or have 
 been formed by the fplitting of the banks themfelves. 
 
 It was long believed, by geologifls, that granite never occur- 
 red in ftrata, but merely formed great maffive mountains. This 
 has been mown to be erroneous by many later obfervers ; yet 
 La Metherie, in the laft edition of his Theorie de la Terre, 
 fpeaking of granite mountains, remarks, " Les mafTes ne font 
 " ni par banes, ni par couches, comme 1'ont pretendu de fa- 
 " vans naturaliftes. J'ai parcouru une grande quantite de ter- 
 " reins primitifs, et je n'y ai jamais vu de couches. Quelque- 
 " fois on appercoit des mafles affez confiderables de granites, 
 " ayant une figure prefque rhomboidale, fuperposes les uns 
 " fur les autres. Mais on ne fauroit regarder ces luperpoli- 
 " tions pour des couches, puifqu'elles n'ont rien de regulier, 
 " et que ces malTes, prefque rhomboidales, ne fe rencontrent 
 " que tres rarement. Le plus fouvent ces granites font fen- 
 " dues, en differens fens, Ces fifTures fe correfpondent 
 
 ** quelque- 
 
A R R A N. 37 
 
 " quelquefois j ce qu'on prendroit, au premier coup-d'ceil, 
 " pour des efpeces de couches ; mais un exameii plus appro- 
 " fondi en fait bientot reconnoitre la difference f." To thefe 
 obfervations we will oppofe that of feveral geologifts who have 
 obferved ftrata of granite, fimilar, I imagine, to thofe which 
 occur in Arran, in different parts of Europe. The late cele^- 
 brated M. Sauffure, whofe accuracy of obfervation is not to 
 be queftioned, difcovered granite difperfed in ftrata in many 
 parts of Europe ; as may be feen by confulting his moft inte- 
 refting and elegant volumes. Reufs, in his mineralogical geo- 
 graphy of Bohemia, has detailed minutely many fimilar ap- 
 pearances ; and my learned friend Dr. Mitchell informs me, 
 that the Reifenbergs, a chain of mountains which feparate Si- 
 lelia from Bohemia, are compofed of granite, for above fifty 
 miles, and in this long courfe it is invariably difpofed in ftrata 
 nearly horizontal J, 
 
 Upon the eaftfide of the glen feveral curious appearances are 
 to be obferved. Of thefe, the moft interefting are the bafaltic 
 
 veins, 
 
 f Tom. iv. p. 352. 
 
 J Mr. Kirwan, in his Geological Effays, refers to feveral other authors who 
 defcribe granite difpofed in ftrata* 
 
3$ A R R A N. 
 
 veins, which traverfe the granitical flrata, as they do the por- 
 phyry and fandflone *. The firft vein which I difcovered, be- 
 ing between three and four feet in diameter, is to be obferved 
 rifing through the granite, feveral hundred feet above the bot- 
 tom of the glen. Its lower part is hid by the heather, and loofe 
 blocks of granite, which cover the fides of the mountains. As 
 it rifes upwards it becomes gradually narrower, and at laft di- 
 vides into two branches, which run through the granite, con- 
 tracting and enlarging their diameter from a few inches to 
 more than two feet. The extremity of one of thefe branches 
 appears either to have been broken, or fo funk inwards as to 
 caufe one part of the branch to appear feparated from the other, 
 
 as is reprefented in the plate ; where A is the granite, B the ba- 
 i ^HA ' / 
 
 fait vein, C the branch having the appearance of being fepara- 
 ted from D by intervening granite J. In the body of the great 
 
 vein 
 
 * However commonly we obferve bafaltic veins traverfing the granite in this 
 ifland, yet it appears to be a rare occurrence in other countries. Reufs never ob- 
 ferved it in Bohemia ; and Sauflure, in a late communication to the Bibliotheque 
 Britannique, affures us that he never obferved any bafaltic rock among granite. 
 Bibl. Brit. vol. vii. 
 
 t Rocks which are difpofed in flrata prefent fimilar appearances with the 
 vein above defcribed, and of this we have a curious example in Saliflmry Craigs 
 near Edinburgh. This hill, which is entirely compofed of rocks of trap forma- 
 
 tion. 
 
A R R A K 39 
 
 vein there is immerfed a confiderable wedge-maped piece of gra- 
 nite, marked in the plate at E ; which has the ufual liardnefs, 
 colour, &c. of that fpecies of which Goatfield is formed* The 
 granite and bafalt are not intermixed at their junction ; no mat- 
 ter is interpofed ; and they are not altered in the leafl by being 
 in contact with each other. In the neighbourhood of this vein 
 were found fpecimens of rock cryflal in cavities of the granite ; 
 and fome of the cryflals were of confiderable fize, but generally 
 of a fmoke colour. I alfo picked up a fpecies of granite fimilar to 
 the pierre graphic which is found at Portfoy *; alfo a (lone much 
 
 refem- 
 .- 
 
 tion, affords fome fine views of its ftratification, in a lofty cliff that extends around 
 a confiderable part of it. Towards the north extremity of this cliff, the red-co- 
 loured fandftone, which lies below the bafaltic rock, is much waved in its courfe, 
 and, at one place, a part of the fandftone ftratum, appears detached and immerfed 
 in the bafaltic rock. The inclofed piece of fandftone is of great fize, ftill pre- 
 ferves its ftratified-like afpeft, only it is very hard. Dr. Hutton reckons it a ftrong 
 proof of the truth of his theory : but Mr. Deriabin, an intelligent mineral ogift, 
 who examined it along with me fome time ago, thinks, that the ftratum is not 
 broken, only that it finks behind the bafalt, as I have conjectured may be the cafe 
 with the vein above defcribed. Dr. Hope informs me that feveral fimilar ap- 
 pearances are to be obferved in the neighbourhood of Edinburgh. 
 
 * I found a fimilar rock among fome foffils fent me from Hudfon's Bay ; and, 
 by a late memoir of Patrin in the Bibliotheque Britannique, (vol. 8. p. 78.) 
 it proved alfo to be a produ&ion of Corfica,' 
 
4 o 
 
 A R R A N. 
 
 refembling the veined granite of M. SaufTure ; and likewife a 
 curious fpecies of granite, where the quartz, felfpar and mica 
 were diflributed in a radiated form, as is the cafe with many 
 zeolites. 
 
 Near to the fummit of Goatfield I picked up Several pieces 
 of rock, which is evidently the fame with the paliopetre of 
 SaufTure, which he found loofe near to the fummit of Mont 
 Blanc in Switzerland f. Lower down, but upon the fame 
 fide of the glen, many fragments of bafalt are to be obferved, 
 lying upon the fides of the mountains, mowing the prefence 
 of bafalt veins ; and at the Keid-voe a great vein is to be feen, 
 rifing perpendicularly through the granite. Nearly at the fame 
 place, I was much furprifed to find feveral columns of dark 
 leek-green coloured pitchflone lying amongft the debris of the 
 granite ; but, after confiderable labour, I was not able to dif- 
 cover its fituation. 
 
 Not far diflant from this, in afcending towards the fum- 
 mit of Goatfield, amongft the loofe blocks of granite which 
 cover its fides, I obferved a curious appearance. Upon 
 
 breaking 
 
 f Voyages dans les Alpes, torn. 70*6, p. 275. 
 
A R R A N. 41 
 
 breaking thefe rocks, with an expectation of difcovering rock 
 cryflal, I found in feveral of them mattes of compact granite, 
 of different fizes, either rounded or angular. Somewhat fimi- 
 lar appearances have been obferved by other mineralogifls : 
 thus Mr. Werner has in his pofleflion a mafs of granite which 
 contains pieces (gefchiebe) of gneifs * ; Mr. Rofter found be- 
 tween Ellbogen and Schlackenwalde, in Bohemia, a great- 
 grained granite f ; and Mr. SaufTure obferved a mafs of granite 
 which contained an oval piece of gneifs J. Mr. Werner rec- 
 kons his fpecimen a proof that the gneifs is of earlier forma- 
 tion than the granite ; in other words, that the pieces of gneifs 
 have been broken off a ftratum which was depofited before 
 the granite. Mr. SaufTure, however, is of an oppofite opinion : 
 he is inclined to believe that thefe pieces of granite or gneifs 
 have been formed fimultaneoufly ; and that they have, by fome 
 peculiar circumflance, affected a rounded form, which is not 
 manifefted in the other parts of the rock. This conjecture is 
 rendered more probable from the following fact : " I have of- 
 " ten ieen, fays he, in veined granite, rounded pieces of a far 
 
 F " finer 
 
 * Werner, Kurze Klaffification der verfchiedenen Gebirgsarten, 
 f Emmeiling Lehrbuch der Mineralogie. B. 3. 
 J Voyages dans les Alpes, 
 
4.2 A R R A N. 
 
 " finer grain, which neverthelefs had been formed fimultane- 
 " oufly, fince we obferved the continuity of the layers of the 
 " fine-grained, with that of die granite in great grain and 
 " thick layers." 
 
 The weft fide of the glen is formed in part by a granitical 
 mountain, named Ben-echleven, which prefents to us the great 
 flat fides of the granitical ftrata. Its top is covered with enor- 
 mous blocks of granite, which reft upon it in a moft fantaftical 
 manner. This mountain declines rapidly towards the N. E. 
 forming a tremendous hollow, named Cory-dain, whofe bot- 
 tom is far elevated above that of Glenrofa, but is lower than 
 the bottom of the next hollow, named the FeUn-hody, which 
 is raifed far above either, prefenting to the bewilder'd eye an 
 amazing fcene of ridged and peaked rocks of granite. In the 
 Cory-dain, the granite, at firft fight, appears to be ftratified ho^ 
 rizontally ; but an examination mews us that is owing to the 
 fplitting of the granite. Here alfo we obferve the granite di 
 integrating, in the form of fand, and, what is more rare, de- 
 compofing in the manner of fome fpecies of bafalt, that is, in 
 crufts *. SaufTure, fpeaking of this kind of decompofition, re- 
 marks ;. 
 
 * Granite decompofes in concentric layers Charpcntier Mineralogifche 
 Geographic <Jer Churfachfichen Lande. 31. 
 
A R R A N. 43 
 
 marks : " Un autre fait, dont je trouvai la folution en exami- 
 " nant ces granites de pres et avec attention, c'eft celui de ces 
 ' exfoliations que j'avois obfervees dans la vallee fuperieure. 
 1 C'eft un fait connu de tous les mineralogiftes, que la plupart 
 " des pier res font plus tendres dans le fein des montagnes qu'a 
 ; leur exterieur, et qu'elles acquierent a l'air un degre de 
 " durete fenfible. II fuit de-la, que la partie exterieure, ou le 
 " bord de la tranche verticale d'une grande aflife de granite, 
 " doit fe durcir par le contact de 1'air, tandis que Tinterieur 
 *' de la meme aflife conferve un certain degre de mollefle. Et 
 " tant que les ailifes inferieures demeurent un peu molles, le 
 " poids enorme de toutes celles qui repofent fur elles doit a la 
 longue les comprimer. Mais les parties exterieures, durcies 
 par le contaft de Tair, ne font pas fufceptibles de la meme 
 compreflion. Elles doivent done s'en feparer, et former ainil 
 *' les exfoliations que Ton obferve *." 
 
 * Voyages dans les Alpes, torn, 6me, p. 318. 
 
A R R 4 N. 
 
 CHAP. IV. 
 
 Defcription of the FOSSILS mentioned in the preceding Chapter. 
 
 PITCHSTONE. 
 
 ARGILLA PICEA^ Werner. RETINITE, La Metherie. QPALVS 
 PICEVS, Gmelin. 
 
 PITCHSTONE from Lamlafh Road. 
 
 Colour. Dark leek-green. 
 
 Litftre. Internally it is glancing *, with a waxy luflre \\ is often 
 
 beautifully iridefcent, and this is particularly the cafe at the 
 
 thin edges of the fplinters. 
 Hardnefs* Gives a few feeble fparks with fteel, but is very 
 
 brittle. 
 
 *-Glanzend, Wachsglanz. 
 
A R R A N. 45 
 
 Trafture* More or lefs perfectly multiplied conchoidal, or 
 fplintery ; often flxiftofe ; and rarely preienu diflindl con- 
 cretions. 
 
 Fragments. Almoft always in the form of four-fided irregular 
 columns. 
 
 Tranfparency. Tranfmits a very little light at the edges. 
 
 Fujibility. At 23 of Wedgewood's fcale, it becomes black, is 
 much rent, and internally a little porous; at 55 it had 
 formed a porous enamel ; and at 70 Q it became perfectly 
 white, and the enamel was little porous, 
 
 It frequently contains a few cryftals of white felfpar, which 
 appear of the nature of adularia ; and I obferve interfperfed 
 grains, apparently of quartz. This fpecies is often intermixed 
 with one fimilar to that obferved at Brodick wood. 
 
 P j T c H s T O N E Erodick Wood. 
 
 Colour. Dark leek-green ; but the number of diftincl concre- 
 tions often give it a lighter hue. . 
 Lujlre. Little glancing *, with a greafy luftre J. 
 Tranfparency. Tranfmits a very little light at the edges. 
 
 Hardncfs* .. 
 
 * Wenig glanzend. . % Fett glanze. 
 
A R R A N. 
 
 Hardnefs. Gives a few {parks with fteeL 
 Fratfure. Uneven, conchoidal, and fometimes fplintery, 
 numerous diftinct concretions ; in the grofs is often flaty. 
 
 It fometimes contains cryftals of white felfpar and quartz, 
 cryftallifed in fix-fided pyramids. 
 
 / 
 
 It decompofes, by the aclion of the weather, in the form of a 
 white tegmen, which is often feparable into layers ; and, by the 
 decompofhion of the felfpar, it gets a cellular appearance, when 
 it requires an experienced eye to diflinguifh it from fome of the 
 productions of Lipari. It is alfo frequently traverfed with another 
 fpecies, which has a greater degree of luftre, and is more diffi- 
 cultly decompofable by the aclion of the weather ; fo that fpeci- 
 mens of this kind, when decompofing, prefent a flriped furface 
 of dark-green and white, the dark-green being the undecom- 
 poied ipecies. Gerhard, in his Mineral Syftem, mentions a fpe- 
 cies of gneifs, or granite, that contains obfidian, a ftone much 
 allied to pitchftone. Dn Townfbn, in his Travels through 
 Hungary, remarks, that this gneifs is a fpecies of obfidian, with 
 black and white layers, containing alfo, probably, a few cry- 
 ftals of adularia and fcales of mica. The ftone I have now de- 
 fcribed appears to be of the fame kind, and this is rendered 
 more probable from its fome.times containing felfpar. 
 
 BROWNISH- 
 
AURA 
 
 BROWNISH-BLACK PITCHSTONE South Side 
 
 Colour. Brownim-black. 
 
 Luftre. Little glancing, with waxy luftre* 
 
 Tranfparency. None. 
 
 Hardnefs. Gives a few fparks with fleet. 
 
 FraElure. Uneven, with a tendency to the conchoidal. 
 
 Fufibility. At 21 'it intumefced a little; its colour was 
 (lightly altered ; the furface glazed, and, internally, porousv 
 At 31, intumefced confiderably, and foftened. It had then, 
 externally, a brownifh glazed covering ; internally, colour 
 is grey, and very porous. At 65 it had intumefced very 
 much; forming an externally cavernous, yellowim-brown 
 coloured mafs. At ioe it became more compact. 
 
 There are generally a few cryftals of white felfpar difperfed 
 through it ; and it acquires, by the adion of the weather, a 
 flight brown tegmen, 
 
 Colour. Black. 
 
 ^ Little glancing, with a waxy luflre. 
 
A R R A K. 
 
 Tranfparency. None. 
 
 Hardnefs. Gives a few fparks with fteel. 
 
 Frafture. Straight, flaty ; and the flates appear to be formed 
 by the fuperpofitioii of fmall foliae. The plates are alfo 
 fometimes covered by a metallic yellow-coloured illinition. 
 
 Smell. When powdered, it emits a bituminous fmell ; which 
 renders it probable it may contain inflammable matter *. 
 
 It has generally a few cryftals of white felfpar difperfed, 
 and thefe by decompofition acquire a brown colour : fome- 
 times we alfo obferve a yellow-coloured, nearly transparent 
 fubftance accompanying the felfpar. 
 
 Thefe different kinds of black pitchflone appear to pafs into 
 bafalt. A curious* fpecimen of this kind occurred to me in 
 the neighbourhood of Kilmichael-Houfe, in Glencloy. One 
 part is common black pitchflone, but it gradually lofes its 
 luftre ; its fracture pafles from the conchoidal to the plain 
 fplintery ; then it gives a grey flreak, is not at all fragile, in 
 fhort, is a fair bafalt. 
 
 O B S E R- 
 
 * Mr. Kirwan has found feveral pitchflones to contain inflammable matter. 
 Kirnvari's Mineralogy. 
 
A R R A Is*. 
 
 OBSERVATIONS. 
 
 When pitchftone was firft difcovered, it was believed by mi- 
 ner alogifts to be the lapis obndianus of Pliny * : its refiny or 
 pitchy colour, however, fumciently diftinguifhed it from the 
 true obfidian, which was afterwards found in Hungary, Ice- 
 land, the South-Sea Iflands f, &c. It was firft difcovered in 
 Saxony ; but it has not till now been defciribed as a Britiih 
 foffil 
 
 From its great refemblance to certain volcanic productions, 
 it has occasioned a confiderable warfare between the Neptunian 
 and volcanic philofophers. The volcanifts refl their opinion 
 on the following facts, i . Pitchftone has been obferved to pafs 
 into obiidian ; a ftone which is found in the neighbourhood 
 of Mount Hecla in Iceland, and hence reckoned volcanic* 
 2. Pearlftone, which feems only a fpecies of pitchftone, is- 
 
 G found 
 
 * Baron Veltheim has endeavoured to fliew that the obfidian of Pliny corre. 
 fponds to feveral other (lones. 
 
 f Newes Bergmannifches Journal. B. i. 94. The whole of the Ifle of 
 Afcenfion, according to Fofter, is compofed of obfidian. 
 
found not only to inclofe balls of obfidian, but even to pafs, 
 on the one hand, to obfidian, and, on the other, to real pu- 
 mice *. Mr. Camara, who had examined the pitchftone of 
 Hungary, was co iviiiced, from its alternation with rocks 
 d^ - idedly Neptunian, that it could not claim a volcanic ori- 
 gin ; and he rendered his proof more complete, when he de- 
 monftrated, that the obfidian was converted into a porous 
 ipongy mafs by the blow-pipe, intimating that it had never 
 been expofed to the action of volcanic fire f . More lately, 
 Lampadius, profeflbr of chemiftry at Freyberg, has found, 
 that the pitchftone is affected by fire in the fame way as the 
 obfidian ; and has completely overthrown the volcanifts, by 
 the difcovery, that the true obfidian contains 2 Ib. 5 oz. of 
 water per cent. || 
 
 As the pitchftone which occurs in Arran is convertible into 
 a porous or fibrous mafs by the action of the fire, and forms 
 
 veins 
 
 * Efmark N. Bergmannifches Journal. Vol. 2. 
 f Bermannifches Journal, 1794. B. 2. $ 243-. 
 t Neues Bergmannifches Journal. B. I. 84. 
 
 [1 A whole pound weight of obfidian was diflilled in a porcelain retort, and 
 afforded 145 grains of pure water. 
 
A R R A N. 51 
 
 veins in fandflone, a volcanic formation cannot be attribu- 
 ted to it. 
 
 / . i 
 
 Fujibility of Pitc hjlone. Pitchftone has been found by mine- 
 
 ralogifls to poflefs fo very different degrees of fulibility, that it 
 leads me to enquire if they have all employed the true pitch- 
 ftone in their experiments. Mr. Morveau Guyton found the 
 pitchftone of Menil mountain, near Paris, to remain unaffected 
 at a very high degree of Wedgewood's fcale *. Mr. Kirwan, 
 who has made many experiments on their fufibility, found that 
 the mofl fufible formed an enamel at 1 30 of . Wedge wood ; 
 but in general were far more refractory, fome remaining un- 
 changed at 1 60 f. It is plain that thefe fofftls are quite di- 
 ftinc"l from the pitchftone of Arran : indeed, were they proved 
 to be the pitchftone of Werner, I would not hefitate to arrange 
 the Arran ftones as a new and diftindl genus. It is now 
 known, however, that feveral ftones, which formerly pafTed 
 for pitchftone, belong to the ferniopal. Dr. Mitchell informs 
 me that the infufible pitchftones of Hungary are femiopals ; 
 and Dolomieu remarks, that the pitchftones of the ifland of 
 
 G 2 Elbe, 
 
 * Journal Polytechnic. 
 
 t Elements of Mineralogy. Vol. i. p, 293, 294. 
 
54 A R R A N. 
 
 Elbe, Piedmont, and the wood which is converted into yellow 
 and white pitchftone from Hungary, are all very difficultly fu- 
 fible, and he therefore reckons them refiniform chalcedonies f, 
 (or, more properly, femi and wood opal.) It is not then im- 
 probable that the pitchflones, which Mr. Kirwan and Morveau 
 Guyton examined, were femiopals, or flones nearly allied to it. 
 
 The real pitchftone, according to Emmerling, is eaiily fufi- 
 ble J ; Dolomieu found the pitchflones of the Ifles Ponces and 
 of the Paduan mountains eafily fulible ; and, laftly, Meffrs. 
 Camara, Deriabin and Lampadius obferved a fimilar fuiibility. 
 Thefe facts agree with my trials on the Arran pitchftone, and 
 entitle me to reckon it the pitchftone of Werner. 
 
 BASALT. 
 
 BASALTES, Marmor. Agricol. BORAX BASAL*$S> Lin. 
 SALTES COLUMNARIS, Waller. ARGILLA BASALTS, Werner, 
 COMMON T&AP, Kirwan, 
 
 BASALT-*- 
 
 f Journal de Phyfique. Vol. 40. p. 215. 
 $ Lehrbuch der Mincralogie. B. i. J 264. 
 
it R A is. 
 
 BASALT South Side. <-.f Gkuch\\ 
 
 Colour. Black. 
 
 Luftre. A number of fhining particles difperfed through it, 
 
 which is probably hornblende *, 
 ^Tranfparency. None. 
 Hardncfs. Scarcely gives fire with fleel. 
 Frafture. Even earthy, but is very compact;. 
 By decompoiition acquires a brownifh-coloured tegmen. 
 
 BASALT, which forms a vein running in the porphyry 
 Head of Glencloy. 
 
 Colour. Lavender blue, intermixed with yellowifh green ; by 
 
 decompofition, red. 
 Lujire. None. 
 'Tranfparency* None. 
 Hardnefs. Yields pretty eafily to the knife. 
 
 Frafture. 
 
 * Hornblende having been found to contain charcoal, or probably carbone, 
 as a conftituent part, has been ingenioufly mentioned by Dr. Walker, as one 
 fa&, to fliew the tranfition from plumbago to hornblende, which he imagines he 
 has obferved in feveral other inftances. 
 
r i A R R A N, 
 
 FracJure. Rather uneven fine fplintery. 
 Fufibility. Melted at 103. 
 
 BASALT, which forms veins traverfmg the granite 
 Eajl Side of Glenrofa. 
 
 Colour. Greyifh, or black. 
 
 Lujire. A number of cryftals of hornblende, difperfed through 
 
 it, give it a flight degree of luftre. 
 Transparency. None. 
 Hardnefs. Gives a few fparks with fteel. 
 FracJure. Uneven earthy. 
 Gives a grey trace. 
 Fufibility. Melted at 58. This fufibility diftinguifhes it from 
 
 the fpecies of bafalt examined by Mr. Kirwan. He found 
 
 them fufible from 120 to 130; and the figurate trap, or 
 
 columnar trap, melted at 100. 
 It contains yellow-coloured olivin, and in greater quantity 
 
 than I have obferved in other fpecies. 
 
 In the former edition of this work, I conjectured that both 
 the pitchftone and bafalt might contain potafh. Since that pe- 
 riod, Dr. Kennedy has analyfed bafalt, wacken-porphyry and 
 greenftone, and thefe he finds to contain a fmall portion of 
 
 foda 
 
A R R A N. 55 
 
 foda and muriatic acid J. Dr. Mitchell, to whom I commu- 
 nicated Dr. Kennedy's experiments, has lately repeated them 
 upon the famous bafalt of Stolpen, but obtained a very diffe- 
 rent refult. Having detected a fmall portion of muriatic acid, 
 he then powdered a quantity of the ftone, and mixed it with 
 fulphuric acid ; then diftilled to drynefs, and lixiviated the folu- 
 tion : the folution was decompofed by the acetite of lead ; the fu- 
 pernatant liquor was then evaporated to drynefs, and the acetous 
 acid burned off. The refidue, which was pure alkali, afforded, 
 vrith nitrous acid, prifmatic nitre : a decifive proof of potafh. 
 
 S I E N I T E. 
 
 , Marmor. PrROPOEcrLus, Plin. et Al. 
 Dr. Walker's ClaiT. Foffil. GRANITES SIENITES, Gmelin. 
 Syft. Nat. 
 
 This rock we have remarked forming ftrata at the head of 
 Glencloy, and it occurs in many other parts of the ifland : I 
 mall now mention its external characters. To prevent repeti- 
 tion, I will fhortly detail the different fpecies, placing the in- 
 gredients in their order of proportion. 
 
 i. Felfpar; 
 
 * Tranfa&ions of the Royal Societj of Edinburgh, vol. 5th. 
 
A R R A N* 
 
 \n< 
 
 i. Fellpar; reddiili. 
 
 Hornblende ; green, and fometimes black. 
 Quartz ; white, and fometimes brown. 
 
 This fpecies is more or lefs compact, and is ibmetimea 
 fhiftofe. 
 
 a. Hornblende ; green* 
 Quartz. 
 Felfpar. 
 
 This aggregate, which is almoft entirely compofed of horn- 
 blende, has the following characters : 
 Colour. Dark leek-gren. 
 Luftre. A mimber of mining points difperfed through the 
 
 the mafs, owing to the hornblende. 
 Tranfparency. None. 
 
 Hardnefs. Gives fire with fleel, but not very plentifully. 
 Leaves a grey trace. It is difficultly diftinguiihable 
 from many fpecies of bafak, and is often intermixed with 
 patches of the firft fpecies* 
 
 3. Quartz. 
 Felfpar. 
 Hornblende. 
 
 This fpecies, oxving to the great proportion of quartz, has 
 much the appearance of a fandftone. 
 
 .}. Horn- 
 
A R R A J^ 2 
 
 4. Hornblende. 
 Quartz. 
 
 Felfpar ; greenifli-coloured. 
 
 The hornblende, in this compound, has fometimes a metal- 
 lic iuftre, approaching to the nature of fchiller fpar ; and 
 the felfpar is tinged green, owing to the difFufed matter of the 
 Jiornblende. 
 
 OBSERVATIONS. 
 
 The different fpecies of fienite were long confounded with 
 bafaltic and granitic rocks : a circumflance which was owing, 
 not only to the want of an appropriate name, but to the diffi- 
 culty of diftinguimiiig the gradations. Werner firfl named it 
 greenftone ; but he now calls it Sienite, from a conviction that 
 it was a fimilar flone which Pliny defcribed as being found at 
 Sienna in Upper Egypt. In antient times it was quarried in 
 great quantities at Sienna ; and from thence was brought to 
 Rome for the building of great public edifices, and for the ufe 
 of the flatuaries, who worked it into pyramids, obelilks, &c. 
 The famous Sarcophagus of Cheops, and Porsapey's Pillar at 
 Alexandria, are now known to be of fienite. 
 
 H 
 
5$ A R R A K. 
 
 As the difcovery of metallic veins is one of the great objects 
 of mineralogy, we think it not out of place to introduce, 
 among the general obfervations we may have occafion to make 
 during the courfe of the work, a fhort account of the different 
 veins of ore which have been obferved traverfing fimilar rocks 
 in other countries. In purfuance of this plan, we may re- 
 mark, that fienite, in fome places, is rich in metals : thus, 
 at Schauffenberg there are veins of filver and lead, and part 
 of the productive Altenberg mine-works are in fienite : we 
 believe that the veins of Strontian in Argylefhire run in a U 
 milar rock. 
 
 CLAY PORPHYRY Cory-Gills. 
 PORPHYRY, German. 
 
 Colour. Brownifh bafis j by decompofition, acquires a white 
 
 tegmen. 
 Lujlre. None. 
 'Tranfparency. None. 
 
 Hardnefs. Is difficultly fcraped with a knife. 
 Fra&ure. Splintery. 
 Smell. Strong earthy fmell, when breathed on. 
 
 FELSPAR 
 
AURA 
 
 FELSPAR Is of a brownifli colour; fometimes white and 
 cryftallized. 
 
 Is of various colours, white, yellow, or fmoke ; 
 of different fhapes, angular, rounded, or regularly cryftallized, 
 prefenting often fix-fided pyramids, which is a rare appearance 
 in porphyry : it is alfo fometimes difperfed through the bails 
 in the form of firings. 
 
 Po R P H y R Y Glencloy* 
 
 The bans of this porphyry differs, in general, but little from 
 that of Corygills : in particular inftances, however, we obferve 
 it nearly in the ftate of hornftone, and having the following 
 characters : 
 
 Colour. Grey. 
 
 Lujlre. None. 
 
 Tranfparency. A very flight degree at the edges, 
 
 Hardnefs. Gives a few fparks with fteel. 
 
 FraElure. Even. 
 
 SmelL A ftrong Imell, when breathed on. 
 
 H 2 The 
 
R R A 
 
 The cryftals of felfpar are much larger than in the clay- 
 porphyry ; and, befides, I obferved it to contain a foftifh Jub- 
 ilance, probably fteatitical. 
 
 The true porphyry was long confined by mineralogifls to a 
 particular flone which was fuppofed to have a jafpideous bafis * r 
 but Werner has extended its fignification much farther, and 
 now reckons eight different kinds. It would be ufeful here to 
 follow the Linnaean mode, by dividing them into diflindl ge- 
 nera ; and then the fpecies might be defcribed in fhort charac- 
 ters, as has been done in botany. This will probably be rec- 
 koned ufelefs labour by thofe who think that foflils are not 
 capable of fuch arrangement : we are well convinced, however r 
 that r in the prefent inflance, as well as in many other parts of 
 mineralogy, much good may be done by fuch attempts. 
 
 In modern times, porphyry has been principally ufed for 
 ornamental purpofes ; and, where compact, it has been found 
 to anfwer well for millflones. The Greeks and Romans ufed 
 it for the conftrudlion of their finefl edifices ; and the ftatuary 
 often cut it into burls, vafes, 6cc. of the mod exquilite work- 
 manfhip. 
 
 The 
 
A R R A N, 6l 
 
 The porphyry in this ifland, fo far as my experience goes, 
 does not afford any veins of ore ; yet in other countries it is 
 fometimes productive. Thus, in different parts of Germany, 
 a fpecies, fimilar to what we obferve in this ifland, has been 
 found to contain veins of tinilone, iron ore, manganefe, ga- 
 lena, and molybdsena. 
 
 SILICEOUS SHISTUS. 
 
 GEMEINER KIESELSCHIEFER, Wern. HORNFLINT. 
 
 Among the debris which covers the bottom of Glencloy, I 
 discovered fpecimens of a rock which feems to be filiceous fhi 
 tus ; but I could not difcover it injtttt. It prefents the follow-, 
 ing characters : 
 
 Colour. Grey, or greyifli black. 
 Luftre. None. 
 
 Tranfparency. Tranfmits extremely little light at the edgesv 
 Hardnefs. Gives fire plentifully with fteeL 
 Fraflure. In the grofs, flaty ; of the fingle plates, more or lefs 
 fine fplintery, inclining to the even. 
 
 It has difperfed through it grains of quartz, and very mi- 
 nute 
 
A R R A N, 
 
 mite particles of a fofter fubftance, whofe nature I could 
 not determine. 
 
 GRANITE. 
 
 GRANITES GENVIXUS, Lin. GRJNI ES DURUS, Cronfted. SAXVM 
 quartzo, fpato fcintillante et mica in diverfa proportions mixtis, 
 compofttum; Waller, Syft. Miner, vol. i. p. 407. 
 
 The granite of this ifland is, in general, pretty compact ; of 
 a whitim-brown colour, owing to the flight-brown tinge of the 
 felfpar. To defcribe all the varieties that occur might be ufe- 
 ful ; but that is more adapted for a fyflematic treatife of mine- 
 ralogy than an outline of this kind. I {hall only, therefore, 
 give a particular account of two fpecies ; the Great-grained, 
 or Common Species, and the Small-grained. 
 
 I. GREAT-GRAINED GRANITE. 
 
 This fpecies is not only remarkable by its forming a very 
 confiderable part of the folid materials of the ifland, but alfo 
 on account of the peculiarity of its compofition ; as it frequent- 
 ly contains three fpecies of felfpar, and the quartz is often cry- 
 ilallized. 
 
A R R A K. 
 
 ifl Species i FELSPAR Is of a white colour, with a flight ten- 
 dency to the brown; having the ufual luflre, tranfparency, 
 and hardnefs. 
 
 id Species^ ADULAHIA f 
 
 Colour. White. 
 
 Form. Either in amorphous mafTes, or cryftallized in hexa>- 
 haedral prifms, bevelled at both ends. 
 
 Liiflre. External, like that of cryftals not much polifhed ; in- 
 ternal, fame. 
 
 tranfparency. Sometimes objects can be feen pretty diftinclly 
 through the cryftals j but when they are a little decompofed, 
 opacity is produced. 
 
 Fr attar e. Plain foliated, and fometimes ftriated. 
 
 Hardnefs. Gives fire, plentifully with fleel. 
 
 Fufibility. At 1 00 the furface was formed into a. yellow-co- 
 loured enamel. 
 
 $d Species Is of a white colour, having nearly the ufual 
 hardnefs, fracture, &c. of the common felfpar ; differing prin- 
 cipally in the luftre, which is like that of polilhed metals, re- 
 fleding, in certain directions, a filver light. 
 
A R R A tf, 
 
 5 Is frequently colourlefs ; alfo greyifh, pale yellow, 
 pale, or dark brown, and fometimes nearly black, when it is 
 called Morion. 
 
 Is very often cryftallized ; and either in the form of hexan- 
 gular prifms, terminated by hexangular pyramids at one or 
 both ends, and the prifms are feamed acrofs. The cryftals are 
 fometimes found feveral inches long, and from two to three 
 inches diameter; of a pale brown, or rather fmoke colour. 
 Thefe lafl are much valued by the lapidaries. 
 
 MICA Is often black; fometimes golden yellow, tombac 
 brown, or green. It is generally in the form of irregular 
 plates ; and pretty frequently hexagonal plates occur, which, 
 being fuperimpofed upon each other, form a hexagonal figure 
 of fome magnitude. It is the mica lamelleuse hexagone of 
 Rome d'Ifle, (vol ii. p. 509.) and the hexagonal mica of the Abbe 
 Huay, (Miner, vol. v. p. 296.) 
 
 The confiituent parts of the granite are very various in their 
 proportion ; but, in general, the felfpar forms the moft confi- 
 <lerable part, then the quartz, and laftly the mica. 
 
 II. SMALL- 
 
R A N. 
 
 II. SMALL-GRAINED GRANITE 
 
 Is very compact, with an uneven fracture ; compofed of 
 felfpar and quartz, in nearly equal proportions, with very few 
 fcales of black mica. It is fubject to much variety; not only 
 on account of the fize of the particles, but alfo from their re- 
 lative proportion, their degree of compactnefs, &c. Some 
 varieties are fo compact, and have fuch a general appearance, 
 as eaiily to pafs for fandftone : but a careful examination of the 
 figure of the particles, the want of fubftramen or bafis, and, 
 laftly, its iituation in the earth, afford fufficiently diftinct 
 marks of difference. It is generally found in fiffures, which 
 traverfe the great-grained granite in all directions ; but it alfo 
 occurs in patches difperfed through it *. 
 
 BRECCIA. 
 
 I have already remarked that the common breccia, whicfe 
 runs among the fandftone, is formed of fragments of fand- 
 
 I ftone 
 
 * It has been obferved in the mountains of the Hartz, that granite affefts the 
 magnetic needle j but it is faid only in mafs, and in a perpendicular vein. Mr. 
 Deriabin, however, informs me, that this is not quite correft ; for he has ob< 
 ferved it to aft in detached pieces. 
 
66 A R R A tf, 
 
 [tone and quartz, immerfed in an arenaceous bafis. Another 
 fpecies occurs upon the fummit of the fienite hills, back from. 
 Glencloy. It has an arenaceous balls, approaching, in appear- 
 ance, to bafalt ; and containing rounded or angular mafles of 
 granite fimilar to that which forms Goatfield, micaceous ihiftu% 
 quartz, porphyry like that of Glencloy, bafalt, and palio- 
 petre. I was not able to difcover its real fituation ; but its 
 composition {hewed that it was probably interpofed between 
 the primary and fecondary flrata. The circumftance of its 
 containing granite, explained a phenomenon which long puz- 
 zled me the appearance of rounded mafTes of granite upon 
 the fummit of fever al high hills ; thefe evidently owing their, 
 origin to the decompoiing breccia, . 
 
A R R A N. 
 
 CHAP. V, 
 
 Cory ; Cock of Arran ; and Loch-Ranz>cu 
 
 iAAVING now given a pretty extended description of the 
 ftrata and foflils in the neighbourhood of Brodick Bay ; I 
 hall, in the next place, proceed to trace the flrata round to 
 Loch-Ranza, which is fituated upon the north-weft fide of 
 the ifland. 
 
 Trom Brodick Bay, the cliffs all around are low, and, for a 
 great way, compofed of the ufual red fandftone, which is 
 much traverfed by veins of bafalt, of various widths, and run- 
 ning in different directions. Coves occur in feveral places, 
 but none are of confiderable fize : frequently calcareous ftalac- 
 tites hang from their roofs. The action of the fea upon the 
 fandftone has given a fingular afpecT: to the whole fhore ; owing 
 
 I 2 tO 
 
68 A R R -A N. 
 
 to foft fandflone being warned away, while the more compact 
 and hard, which appears to have been formed in fifTures, is left 
 {landing in long ridges, or criflae. The fandflone, as it rifes 
 upwards, forms part of the lower region of Goatfield, in the 
 vicinity of the micaceoxis fhiflus, which it, in all probability, 
 covers. About a mile from the Cory, nearly one hundred feet 
 above the level of the fea, there is a flratum of limeflone, 
 about twelve feet thick, running at an angle of 20, and co- 
 vered with red-coloured argillaceous fandflone ; but, below:, 
 interpofed between the limeflone and fandftone, there is a 
 layer of a red fhiflofe clay. In this clay I obferved regular fe- 
 ries of fliells, depofited in layers, (all appearing of the fame 
 fpecies,) with their convex fides regularly downwards. The 
 flratum is fometimes flraight, but often waved and twifled. 
 It alfo frequently contains radiated calcareous cryflals, which 
 are of a reddifh colour, owing to the admixture of iron. In 
 a nfTure of the fandflone, above the limeflone, I obferved fla- 
 lactites of peat, of confiderable fize and confiflence, which ap- 
 pear to have been formed by the infiltration of the foluble peat- 
 matter through the fandflone. To the N. of this flratum there 
 is a confiderable ravine, which luckily afforded me an opportu- 
 nity of obferving the junction of the different ftrata. Here I 
 traced the common red-coloured argillaceous fandflone from 
 the more to a confiderable height, and, in fome places, ob- 
 ferved 
 
A R R A N. 69 
 
 ferved it intermixed with fragments of quartz ; thus forming 
 a kind of breccia. As we approach the primitive rocks, the 
 fandflone flrata become more elevated ; and, at length, I ob- 
 ferved it lying on a compact fhiftofe rock, which appeared to 
 be of the nature of micaceous fhiflus ; but it was fo much de- 
 coinpofed by the action of the weather, that I could not well de- 
 termine exactly as to its particular defignation. This micaceous 
 miftus ? continues but for a fhort way, when it is to be feen 
 lying on the granite, which rifes upwards, forming a very deep 
 afcent, which leads to the rugged and flerile-looking Coryglen. 
 This glen is very precipitous on all fides ; is broader than 
 any in the Goatfield groupe> but is comparatively fhorter : its. 
 bottom is higher than that of Glenrofa, but not fo much ele- 
 vated as that of the Cory-dam or Feun-hody. It is entirely 
 eompofed of granite ; whicll'is here fplit, as ufual, into im- 
 menfe blocks, that are piled in vaft tumuli upon the tops of the 
 furroundiiig mountains, or cover the fides and bottom of the 
 glen, as with ruin and defolation.. 
 
 Having returned again to the fea-fliore, I continued my 
 journey j and, as I approached the Cory, obferved a vein of 
 foft, red, fhiftofe fandflone, containing rounded pieces of ar- 
 gil running through the fandfhone N. E. and S. W. At the 
 Cory, where there are a few houfes, I obferved quarries of 
 
 fandftone v 
 
*j7O A R R A N, 
 
 iandftone, of a beautiful white colour, and of good confiftence 
 for building. Thefe quarries are now worked, by a company, 
 for the conftruction of the Crinan Canal. Here there is alfo a 
 ilratum of limeftone, about thirty feet thick, confiderably in- 
 clined to the horizon, running N. N. W. and divided into ftra- 
 tulse, as the ftratum formerly mentioned, with intervening 
 clay and {hells, but the clay is more or lefs indurated. From 
 this towards Weft Sanicks, the more is compofed of the com- 
 mon red-coloured fandftone, interfered here and there with 
 veins of bafalt ; but it is often fo covered with bowlder ftones 
 of different kinds, as to render travelling very difficult. The 
 rounded mafles of granite, fcattered up and down here, are of 
 a moft aftonifhing fize ; fome of them hundreds of tos weight. 
 Near to theSanicks, there is an immenfe ftratum of breccia, which 
 is compofed of rounded fragments of quartz, and micaceous 
 ihiftus, cemented by an arenaceous ground. The breccia is in 
 many places much broken. Immenfe mafles of it, many hund- 
 red tons weight, lying feparated from the ftratum only a few 
 feet, render it probable, that thefe mafles were difunited by 
 froft. In one place, I obferved, a confiderable fection of the 
 breccia, which I examined very carefully, in order to difco- 
 yer if the mafles of quartz, were comprefled and fmaller at 
 the lower than the upper part, but no difference could be ob- 
 . vcd, Very remarkable inftances of this kind have been ob- 
 ferved 
 
A R R A N. ~i 
 
 ferved in other countries; thus in Bergm. Erde-Befch. 182, 
 we are told that in the mountains of Quedilia? and Portfiasllet 
 in Norway, which confifl of an' argillaceous puddingftone, the 
 filiceous pebbles it contains, are obferved to be compreffed to the 
 thicknefs of the fourth of an inch, in the lower parts of the 
 mountains, but to increafe in fize and roundnefs in proportion 
 as their fituation is higher. Alfo in the Yivarois, the lowed 
 ftrata of primitive limeftone, have been found of the thicknefs 
 of one-tenth of an inch ; but in proportion to their elevation 
 in the mountain their thicknefs increafes, until at its fummit, 
 it arrives at thirty or forty feet. i. Soulavie, 178. Ferber 
 made the fame obfervation in England. 
 
 At a little di fiance from the more, is the entrance into 
 the deep South Glen-Sanicks, which is about four miles long, 
 running nearly E. and W., and bounded on both fides by lofty 
 mountains. As I obferved a confiderable flream of water 
 running through this glen, I determined to examine it, as it 
 was probable that the ftrata would be well expofed. Having 
 walked for upwards of a mile in the direction of the glen, 
 1 defcended into the ravine formed by the water, but found 1 
 ftill the ufual red-coloured argillaceous fandftone. As we con- 
 tinued clambring upwards, I obferved feveral veins of fulphat 
 o barytes, fome nearly four feet wide, travelling the fand- 
 
 ftone ; 
 
J2, A R R A N. 
 
 ftone ; and, by a little care, I obtained fpecimens pretty well 
 cryftallized. About a quarter of a mile further on, a very 
 compact arenaceous breccia (principally compofed of rounded 
 pieces of quartz, and a fpecies of bafalt, which has, interpofed, 
 grains of felfpar, and a yellow fubflance,) makes its appear- 
 ance ; and this extends to a confiderable diftance ; but it is at 
 length apparently interrupted by a flratum of hornblende 
 rock. This flratum of hornblende rock is only a few feet 
 wide ; and it appears to lie immediately on the granite. I have 
 to regret that I could not obtain more fatisfaclory views of the 
 junction of thefe ftrata, owing to the great covering of debris. 
 I am fomewhat confident, however, that the difpofhion of the 
 ftrata is pretty nearly as now ftated, viz. that in the lower 
 parts, and for a confiderable way upwards, is argillaceous fand- 
 ftone ; next, arenaceous breccia ; then a bed of hornblende rock ; 
 and, laflly, granite. The glen is now bounded by lofty granite 
 mountains : on the N. is the Caimes, with part of Caime-na- 
 caillich ; and, towards the S., Keich-na-hien and Goatfield 
 form boundaries awfully grand. Its fides are much furrowed 
 by the action of the rain : which circumflance, with the red 
 colour of the decompofing granite, the immenfe granitic blocks 
 which cover the fides and tops of the mountains, form alto- 
 gether a fleril and tremendous fcene. 
 
 In 
 
. 
 A R R A N, 73 
 
 \ 
 
 In lonely regions, here, retired 
 
 From little fcenes of Art, great Nature dwells 
 In awful folitude. 
 
 Here I obferved feveral veins of bafalt traverfing the gra- 
 nite ; and, in fome places, I could trace the perpendicular veins 
 from the top to the bottom of the mountains. At the top of 
 this glen, is the hollow called Cory-na-huave, which is bounded 
 by Caime-na-callich and Keid-voe. Its bottom is higher than 
 that of G len-Saiiicks ; and is entirely compofed of granite, 
 traveried with veins of bafalt, fome of which have a confi- 
 derable degree of curvature. 
 
 Having examined this glen as far as my time would permit, 
 I was again proceeding toward the fea-fhore, when , I thought 
 it might be interefling to examine the junction of the granite 
 and fliiflus in fome of the neighbouring glens. I therefore 
 changed my courfe, as foon as we came to the rock of breccia 
 which I have jufl defcribed ; and from this I crofTed over a hill 
 of fimilar rock to North Glen-Sanicks. Here we obferved a 
 ilream running through the glen, and in it I found the fhif- 
 tus in immediate contact with the granite. The miflus appear- 
 ed to be a very compact micaceous rock ; but the granite was 
 not intermixed with it at the junction, nor were there any veins 
 
 K to 
 
7-f 
 
 A R R A N 
 
 to be obierved fhoocing from the granite into the micaceous 
 rock. We now crofled over the hills into another glen, where 
 I obferved another junction of the granite and fhiftus, but it 
 prefented nothing remarkable. 
 
 I now returned again to the fhore, below the entrance of 
 South Glen-Sanicks ; fo that I might proceed regularly on my 
 tour through the ifland. After pafling the Sanicks burn, I 
 found the fandftone, breccia and bafaltic veins flill continuing ; 
 but the appearance of the mountains was much changed. The 
 peaked fummits, and almoft perpendicular, furrowed fides, 
 now difappeared : the mountains were cloathed with heather to 
 their fummits,^ which were more or lefs round-backed: inti- 
 mating an alteration in the materials of which they are compo- 
 fed ; which is really the cafe, as the granite had now difap- 
 peared, the fummits of the largeft hills being of micaceous 
 fhiflus, which, in fome places, alternated with talcaceous fhiflus. 
 I now wandered along a mile or two of fhore compofed of 
 fandftone ; when my attention was arrefted by the remains 
 of workings for coal, at a little diflance from the fea-mark 
 the Cock of Arran. This coal flratum, which is but of 
 fmall extent, runs in the fandftone, accompanied by the ufual 
 coal metals, as, argillaceous ironftone, fhiftofe clay containing 
 numerous vegetable impreflions, &c., and at the bottom of a 
 
 mountain 
 
A R R A ST. 75 
 
 mountain of micaceous fhiftus. It is fimilar to that which 
 is found at Kilkenny in Ireland, and is called blind-coal*. 
 I obferved two pits, about fifteen feet deep, which had been 
 dug in cutting the coal ftratum ; but, as the coal foon difap- 
 peared, the pits were left, and the falt-pans which had been 
 erected were rendered ufekfs. The fituation of this ftratum is 
 fuch, as to preclude all hopes of finding any confiderable quan- 
 tity of coal, although frefli fe&ions were made : for we inva- 
 variably find it to be the cafe, that wherever coal ftrata come 
 into the vicinity of high mountains, they then moil certainly 
 decreafe in breadth, and become bad, owing to the great ad- 
 mixture of earthy matter. Thus, many of the feams of coal 
 which have been found in France are trifling, and continue 
 but for a fhort way ; owing to their fituation, being found in 
 rallies that are bounded by granite, or other primary rocks f , 
 
 K 2 The 
 
 * Dr. Button conceives that this fpecies of coal prefents an irrefragable proof 
 of the truth of his theory. Here, fays he, is a coal having all the properties of 
 that which has been fubmitted to the aclion cf heat; the bitumen is feparated, 
 and charcoal remains. To the Neptunifts, this affords one of the ftrongefl ar- 
 guments againft the theory. The feparation of bituminous matter fhows a Want 
 of immenfe compreffion, which is the grand fundamental bafis of the hypothefis. 
 It is indeed this circumilance, principally, which diftinguifhes it from, the vol- 
 canic theory, and has led Mr. Kirwan to name it the Plutonic. 
 
 f Journal des Mines, 
 
76" A R R A N. 
 
 The great frequency of bafaltic veins is another caufe which 
 may render the coal, if it fhould again be deemed worthy of 
 attention, of an indifferent quality, and difficult to work. 
 
 From this ftratum to the Cock, which is the mo ft northern 
 point of the ifland, the more is covered with immenfe mafles 
 of fandftone and breccia, w r hich have tumbled from the neigh- 
 bouring hills by the adlion of the weather. Ironftone is found 
 fcattered upon the more, and is probably connected with the 
 coal workings. The Cock is not, as I expecled, a headland, 
 but merely an enormous mafs of fandftone, lying loofe upon 
 the fhore, having a fancied refemblance to the head of the 
 cock. Here the cliffs are of confiderable height, compofed of 
 fandftone and breccia, traverfed with veins of bafalt of various 
 fizes. One of thefe veins is compofed of a reddifh brown-co- 
 loured bafalt, with, interfperfed, white-coloured, apparently 
 cryftallized fpecftein of Werner ; and the bafalt, where it is in 
 contact with the fandftone, is hard, and much refembles horn- 
 ftone. After leaving this, a ftriking appearance prefents itfelf 
 to our view, of the whole face of an immenfe ftratum of breccia, 
 which was {nattered to pieces, and rolled towards the fea, by an 
 intenfe froft fome years ago : the crafh of its fall was heard far 
 off. The fandftone upon this part of the coaft is alternated 
 layers of fhistofe clay ; and where the clay is wafhed 
 
 away 
 
A R R A K. 77 
 
 away, the fandstone lies expofed, having the appearance of a 
 regular pavement. If we examine it more nearly, we find the 
 fandstone strata fplit into two, four, or fix-fided irregular fi- 
 gures, and connected together by the clay, which gives it 
 an artificial afpect ; by the decomposition of the clay, the 
 pieces of fandstone are feparated, and lie fcattered on the 
 more, and are apt to be taken for the work of art. From 
 this to within a mile of Loch Ranza, the fandstone, as ufual, 
 forms the cliffs upon the more, and is backed by mountains 
 of micaceous fhistus, upon which it rests. Here, however, 
 the fandstone difappears, and the micaceous fhistus now forms 
 the cliffs, which become higher as we approach Ranza. At 
 the place where the fandstone difappears, there is a great 
 bafalt vein, about thirty feet wide, running in a rock inter- 
 mediate between ardefia and micaceous fhistus. As we ap-r 
 proach nearer to Loch Ranza, the fea has expofed feveral 
 other fimilar appearances, but far more distinct than the 
 first. Thefe veins are of various fizes ; fome are curved in 
 their direction ; one, in particular, is forked, or divided into 
 two branches, which run in very different directions through 
 the micaceous fhistus. A few hundred yards from the en- 
 trance of the Loch, the fea has formed an interefting fec- 
 tion of the ftrata, which demonftrates, in a Satisfactory man- 
 ner, the relative pofition.of the fandftone,- limeftone, and mi- 
 caceous, 
 
78 A fc R A N. 
 
 caceous miftus. The micaceous miftus which forms the 
 iliore, is inclined at an angle of 45 and dips to the S. E. ; 
 the fecondary ftrata, are inclined at an angle of 45, but dip 
 to the N. W. fo that the two kinds of ftrata meet together, 
 iimilar, as Hutton remarks, to the two fides of a lambda, or 
 the roof of a houfc. The fecondary ftrata are of red colour- 
 ed argillaceous fandftone, (which fometimes appears pamng 
 into breccia :) which alternates with limeftone. This lime- 
 ftone fometimes contains mafles of hornftone, a fact, fome- 
 what fimilar to the occurrence of flint in the chalk beds of 
 England. Sauffure remarks that hornftone is confined to the 
 fecondary limeftone, quartz being the fporadic matter which 
 he has obferved in primitive limeftone. Many other veins 
 may be obferved traverfing the micaceous fhiftus, before we 
 arrive at the entrance of Loch Ranza, but any detailed ac- 
 count of thefe would be but a repetition of what has been 
 already mentioned. 
 
 GLEN-RANZA. This glen is about two miles long, and half 
 a mile broad, running nearly north and fouth, bounded on 
 both fides by lofty round-backed mountains, that rife at a 
 very confiderable angle, and are nearly of the fame height 
 on both fides of the glen. The inclination of the oppofite 
 mountains is the fame, and the ftrata run at the fame angle. 
 
 The 
 
i 
 
./r.\cTjf>.v f>t 
 
 \ A .\'/i/ir/ \ft//i 
 
 I) Hrt.Ht/f/f I'fltl 
 
 
 B 11 /.//n, .\'/r/n .\'fmf'ft 
 
 n.i\.\:\ 
 
 Ji, 
 
A R R A N. 79 
 
 The bottom of the glen is but little elevated, and nearly le- 
 vel ; about one half is covered with a fait water loch, which 
 adds greatly to the beauty of this romantic fpot. The hills 
 are compofed of micaceous miftus, containing a greater or 
 lefler proportion of quartz and mica ; indurated chlorite is 
 alfo difperfed through it, and towards the mouth of the loch 
 there is a conliderable ftratum of ardeiia, or primitive argil- 
 laceous fhiftus, bounded by the ftrata of micaceous miftus. 
 
 GLEN-ES-NJ-BIRACH. From the top of Glen-Ranza, we en- 
 ter, by a narrow paffage, into a long deep glen, running near- 
 ly in the fame direction, called Glen-es-na-birach, bounded on 
 both fides, with mountains of compact micaceous miftus, 
 which lie upon the granite. The granite and miftus are often 
 intermixed at their junction, and fometimes fmall granite veins 
 are to be obferved ifTuing from the mailive granite, and tra~ 
 verfing the miftus. This latter appearance was confidered by 
 Dr Hutton, as a demonftration of the truth of his theory, with 
 regard to the formation of granite. I will not now make any 
 obfervations on this particular opinion, as I intend to consider 
 it fomewhat fully in a fubfequent part of the work. As we ad- 
 vance further up the glen, the micaceous miftus difappears, 
 when both fides are formed of granite, of the fame kind with that 
 of Goatfield. The bottom is alfo formed of granite, as is well 
 
 demon ftrated 
 
8o A R R A N. 
 
 dcmonftratcd by the ft ream, or burn, which has laid bare the 
 rocks through the whole extent of the glen ; it is indeed by 
 rivulets of this kind that we are often enabled to have a dif- 
 tinct view of the mineral ftruclure of highland countries. 
 From the further extremity of this glen, is the afcent to Caimc- 
 na-caillich, which is in feveral places rugged and difficult, from 
 the number of loofc blocks of granite fpreading all around. 
 Upon afcending, we firfl flop at the edge of what is called the 
 Garife-hodie : Here a wonderful and moft tremendous fcene 
 prc fonts itfelf to our view. An immcnfc hollow, many hund- 
 red feet deep, dreadfully rugged and broken, almoil entirely 
 furrounded with mountains, whofe ferrated fummits arc cover- 
 ed with immcnfe tumuli of granite, exhibits to us, in very le- 
 gible characters, the vaft operations of nature, in the forma- 
 tion and decompofition of our globe. What man, poiTefled of 
 rcafon, contemplating this awful fcene, could doubt of the ex- 
 iftence of that BEING, whofe power and wifdom are far be- 
 yond the reach of human comprehenfion ? If fuch a man exift, 
 vanity, not foundnefs of judgment, is the diftinguifhing fea- 
 ture of his character. Few, indeed, of thofe who deny, or 
 even doubt the cxiftciice of Deity, have ever beheld, far Icfs 
 lludied, the ftupendous and awful works of nature. It is not, 
 then, much to be wondered at, that the pride and arrogance, 
 which fo often characterifc the clofet philofopher, fhould find 
 
 their 
 
A R R A K. Si 
 
 their way to mix with their daring and impious fpeculaii 
 
 which have for their end the propagation of the worfl princi- 
 
 I 
 pies, the clifTolving of all the bonds, and deftroying the fwect- 
 
 eft endearments of human fociety. 
 
 Upon the edge of the hollow, I obferved feveral fragments 
 of porphyry, but I could not difcover any fixed rocks of it, 
 owing to the blocks of granite fcattcred all over the fides of 
 the mountains. In afcending from this, to Caime-na-callich, fc- 
 veral other appearances of porphyry, and alfo fragments of ba- 
 falt and pitchftone, prefcntcd themfelves. After considerable 
 fatigue I was fo fortunate as to difcover two veins of bafalt, 
 upon the fide of Caime-na-caillich looking into the Garife- 
 hodie ; and, between thefe, there appeared a perpendicular vein 
 of pitchftone, all running in the common granite. This pitch- 
 flone, is of a green colour, much refembling that from Bro- 
 dick wood. It forms a vein, about two feet wide, and, what 
 is remarkable, it is formed into two regular columns, from 
 two to twelve inches diameter, and having from three to fix 
 irregular fides *. I could not, however, difcover the fituation of 
 
 L the 
 
 f It would be worthy the attention of future travellers to determine whether 
 the bafalt be not included in the fame rein with the pitchftone, thus forming a 
 ftratified vein. 
 
J2 A * R A N, 
 
 the porphyry, although it was fcattered in fome places of the 
 mountains in confiderable quantities. Having gained the 
 
 9 
 
 i'ummit of this great mountain, which is nearly of an equal 
 height with Goatfield, I had a very grand view ; yet not fo 
 extenfive as that from Goatfield. 
 
 Its fummit has a moil fingular appearance, owing to its be- 
 ing covered with enormous piles of quadrangular maiTes of 
 granite, which reft upon each other in a moft fantaftic man- 
 ner, and have much the appearance of artificial tumuli. 
 Such appearances are by no means peculiar to Caime-na- 
 callich, for I have already remarked them upon the top 
 of fever al of the granite mountains in the ifland. Here we 
 can trace the granite in its various ftages of decompon- 
 tion, from the folid rock to the loofe fand ; in its begin- 
 ning difintegration it fplits into mafTes, having a greater or 
 lefler tendency to the quadrangular form; but thefe mafles 
 have flill a degree of connection amongfl themfelves, as is the 
 cafe upon the mountain top. The next flep is the enlarge^- 
 inent of the fiflures, by which the mafles are loofened from, 
 their connection, and tumble down from their elevated fitua- 
 tions, upon the fummits of the neighbouring mountains, or 
 are hurried with impetuous velocity down the mountain fide, 
 covering the bottom of the glens with thefe ftupendous ruins. - 
 
 Laflly 
 
A R R A N, 83 
 
 Lafcly, thefe detached mattes, by the action of the weather, are 
 completely difintegrated, forming a loofe fand, which is left 
 upon the tops or fides of the mountains, or is carried in great 
 quantities to the fea more by the torrents *. SaufTure, at fec- 
 
 L 2 tion 
 
 * Dr Hutton remarks, that the flony matter of this globe has been formed 
 "by the decay of a former world, whofe debris has been colle&ed by various means, 
 at the bottom of a former ocean. This part of the Huttonian theory differs but 
 little from that of Count Buffon, yet it is fo material for the general fupport of the 
 whole, that if it (hall be difproved, the folidity of the theory in general will be much 
 impaired. If we examine a few of the numerous fals on this fubject, we mail 
 find no proof of the debris being carried to the fathomlefs depths of the ocean ; on 
 the contrary, we will obferve it difpofed of in a very different way. Thus in 
 fome cafes, the loofe materials warned from the mountains, are obferved filling up 
 great hollows ; and in other inftances, rivers depofit their earthy matters, and 
 form extenfive plains, and not unoftcn the debris having reached the fea more, 
 is thrown back upon the fame or other mores. The following fails are in proof 
 of thefe remarks. The plains of Crau and Camarque, in lower Languedoc, were 
 formed by depofitions from the Rhone, and the plains of Lombardy from that of 
 the river Po ; the lands of Holland and the Delta of Egypt, feem alfo to -be 
 depofitions of the debris, brought to the fea more by great rivers. In Egypt, 
 the gathering of debris is very great, as is well authenticated by hiftoric evi- 
 dence : thus, we are told, that the town of Damietta, in lower Egypt, about the 
 year 1243, was upon the fea more, but is now about twelve miles from it: and 
 the town of Foc-ah which, three hundred years ago, was fituated at the mouth of 
 the Nile, is now fevn miles diftant. The country about the Baltic is alfo gradu- 
 ally 
 
84. A R R A N. 
 
 tion 604 of his Voyages dans les Alpes, remarks, that gra- 
 nite is difpofed in ftrata, but that they are not always to be 
 diftinguifhed, particularly in the granite of low countries 
 and plains. This he conceives to be owing to the granite 
 of low hills containing a great quantity of pierre de corne. 
 
 This 
 
 ally incroaching upon the fea. Linnaeus remarks that the fca ports of eafl and weft 
 Bothnia are every year decreafing, and becoming incapable of admitting veffels ; 
 the inhabitants of the ports are obliged to change their feats, and fometimes re- 
 move a quarter of a mile nearer the fea. On the eaflern fide of Gothland, near 
 Hoburg, the increafe of the continent for thefe laft ninety years, is about two or 
 three toifes annually. The inhabitants of weft Gothland remark that the fea de- 
 creafes every ten years four or five lines perpendicularly, which, amounts, to for- 
 ty or fifty lines in a century. According to this calculation, 6co years ago the fea 
 was 25 inches deeper than it is at prefent. In Arran we have alfo a ftriking 
 proof of the formation of land by the accumulation of debris. Innumerable other 
 inftances might be mentioned. But we will not cite more, but conclude this note 
 with the following ingenious obfervations from Mr Kirwan's Geological E flays. 
 f< Mariners were accuflomed, fays he, for fome centuries back, to difcover their 
 fituation by the kind of earth or fand brought up by their founding plummets, 
 a method which would prove fallacious, if the furface of the bottom did not con- 
 tinue invaiiably the fame. Fortis in his Travels through Dalmatia, p. 285, re- 
 lates that urns thrown into the Adriatic upwards of 1400 years, fo far from be- 
 iag covered by mud, were found in the fame fituation, as they could have been 
 fuppofed to have been the firft day of their fall ; therefore, notwithflanding many 
 jparticles of earth are, by rivers, conducted to the fea, yet none are conveyed to 
 
 any 
 
A R R A N. gj 
 
 This pierre de corne, he continues, contains a great proportion 
 of argillaceous earth ; and as mod ftones, which have this 
 earth as a coiiftituent part, and in confiderable proportion, 
 fplit into rhomboidal mafTes, fo he concludes that it is the 
 earth of the pierre de corne which is the caufe of the fplitting of 
 granite, thus forming the numerous mafTes which prevent us 
 from obferving the ftrata. This explanation, however inge- 
 nious, does not hold true with regard to the granite of this 
 ifland : no argillaceous ftone of that kind enters into its com- 
 pofition, yet ftill it fplits into very numerous rhomboidal 
 maffes. 
 
 GLEN-HALIMIDEL. Upon the eaft fide of Glen-Ranza there 
 is an opening leading to a glen, named Halimidel, which is 
 
 about 
 
 any diftance, but are either deposited at their mouths, or rejected by currents or 
 by tides j and the reafon is, becaufe the tide of flood, is always more impetuous 
 and forcible than the tide of ebb, the advancing waves being prefied forwards by 
 the countlefs number behind them ; whereas the retreating are preffed backward 
 by a far fmaller number, as muft be evident to an attentive fpe&ator ; and hence 
 it is, that all floating things caft into the fea, are at lad thrown on more, and not 
 conveyed into the mid regions of the fea, as they mould be, if the reciprocal 
 undulations of the tides were equally powerful." Kirwan's Geological EfTays >Xi 
 p. 440, 441 = 
 
S'6 A R R A N. 
 
 about two miles long, running W. N. W. and E. S. E. but 
 which foon changes its direction, running nearly in a line with 
 Es-na-birach. It is narrow at the bottom, but widens upwards, 
 owing to the inclination of the fides, which form an angle of 
 about 60 ; and the bottom alfo rifes, forming a confiderable 
 angle with the fides. It is compofed of various fpecies of mi- 
 caceous fhiftus and quartz. In feveral places bafalt veins may 
 be obferved traverfing the micaceous fhiftus, many hundred 
 feet above the level of the fea : even in the bottom of the glen, 
 where the burn has expofed the micaceous fhiftus, we obfervc 
 bafalt veins crofling it. Upon the eaft fide of the glen, feveral 
 hundred feet above the level of the fea, there are two quarries, 
 which were formerly worked for ardefia, but are now difconti-^ 
 nued. The ardefia is of various colours ; generally bluifh or 
 green, and is intermixed with white quartz ; the fiflures often 
 contain cryftals of aclynolite, and a fpecies of quartz penetra- 
 ted with actynolite, forming a ftone fomewhat refembling 
 prafe* 
 
A R R A N. 
 
 CHAP. VI. 
 
 * 
 
 Defer ipt ion of the FOSSILS mentioned in the preceding Chapter. 
 
 XIMESTQNE Cory. 
 
 Colour. Grey. 
 
 Lujlre. A very faint degree of luflre* 
 
 Transparency. None. 
 
 Hardnefs. Scrapes with a knife. 
 
 Smell. Emits a ftrong earthy fmell. 
 
 Frafture. Even, fine, fplintery, and very compact. 
 
 Fufibility. At 140 Wedgewood, no appearance of fufion. 
 
 Another fpecies is alfo found at the Cory; of a dark-brown 
 colour, minutely foliated, difficultly fcraped with a knife, and 
 wanting tranfparency. 
 
 1 LIME- 
 
88 A R R A N. 
 
 LIMESTONE near the Cock. 
 
 Colour. Brick red. 
 
 Liiftre, A flight degree of luftre from fome difperfed folias. 
 
 Tranfparency. None. 
 
 Hardnefs. Pretty difficultly fcraped with a knife. 
 
 Frafture. Generally foliated, paffing to the compadl earthy. 
 
 INDURATED LITHOMARGA? -found loofe on the Jhore between 
 Brodick Bay and the Cory. 
 
 Colour. Light blood-red. 
 
 Luftre. None. 
 
 Tranfparency. None. 
 
 Hardnefs. Yields to the knife with confiderable difficulty; 
 gives a pink flreak. 
 
 Frafture. Even, bordering upon fine fplintery Does not 
 
 {lain the finger ; feels dry j does not acquire a polifh by 
 friclion ; after immerfion in water for two days, no ap- 
 pearance of difintegration, 
 
 BASALT 
 
A R R A N. 
 
 BASALT -from a vciti near the Sanicks* 
 
 Colour. Greyifh green. 
 
 Luftre. None. 
 
 Traj2fpare?icy. None. 
 
 Fragments. Uneven earthy. 
 
 Hardnefs. Pretty eafily fcraped with the knife. 
 
 Fufibility. Melted at 58, 
 
 BLIND - COAL. 
 
 KOHLENELENDE, German. NATIVE MINERAL CARBON, Kirwan. 
 
 Colour. Black ; when frefli broken, reflects a golden yellow, 
 
 or violet colour. 
 
 Lujlre. That of metals not much polifhed. 
 Hardnefs. Yields rather with difficulty to the knife. 
 Fratture. Plain foliated. 
 
 Is not coated with illinitions, as that from Kilkenny in Ire- 
 land. It does not {tain the fingers. 
 
 Hardly burns until wholly ignited, when it confumes flow- 
 
 M ly, 
 
iy, \vith a light, lambent, blue flame, which continues for a 
 iliort time. According to Mr. Kirwan' s method, it contains, 
 in the 100 parts, 93 of carbon and 7 of aflies. 
 
 Mr. Kirwan, in the fecond volume of his Mineralogy, re"- 
 marks, that coals are not foluble in acids. I have obferved, 
 however, that the coal of Arran is rendered foluble in wa- 
 ter, by means of the nitrous acid, the carbonaceous bails ap- 
 pearing to be converted into an oxyd.. 
 
 This fubftance has been placed in various parts of the mine- 
 ral fyftem, as with black-lead, molybdama, manganefe, &c. ; 
 but the lat correct analyfes that have been made, mow it is 
 carbon nearly in a pure ilate. Mr. Kirwan, upon consideration 
 of its great purity, places it at the head of the coals, with the 
 name of Native Mineral Carbon. 
 
 ARDESI A. 
 
 ARGILLITE, Kirwan. PRIMITIVE ARGILLACEOUS SHISTVS, 
 DACHSCHIEFER, Emmerling* ARDESI A TEGVLARIS, Linn. 
 
 Colour. Greyifh blue, or greyifh green ; fometimes both co- 
 lours are intermixed in the fame fpecimen.. 
 
 LuJIre. 
 
A R R A N. 9 1 
 
 * Silky. 
 Tranfparency. None. 
 Fratture. Streight, flaty. 
 Fragments. Tabular. 
 
 Hardnefs. Yields pretty eaiily to the knife. 
 Streak. Grey. 
 
 Does not adhere to the tongue ; feels rather greafy, particu- 
 larly the green-coloured ; does not ftain the fingers. There 
 are often contained in the filTures, cryflals of glafTy ac- 
 tynolite. 
 
 MICACEOUS SHISTUS. 
 
 LEPIDOTES, Dr. Walker. SHISTOSE MICA, Kirwan. GLIMMER. 
 SCHIEFER, Werner. GNEISSUM MICACEUM, Gmelin. 
 
 The few obfervations I have to make on this genus of rock 
 fhould, in Uriel order, have been introduced in chapter fecond ; 
 but I wifhed previouily to examine a greater number of fpeci- 
 mens, fo as to be better able to give a general idea of the 
 whole. 
 
 It would be inconfiitent with the brevity of this outline to 
 
 M 2 defcribe 
 
2 A R R A N. 
 
 defcribe all the fpecies of this rock: I fhall therefore only 
 mention it in general. 
 
 MICA. The mica, in general, is of a grey, or black co- 
 lour; the fcales very fmall, and indeed often hardly diftin- 
 guifhable. 
 
 Is of a white colour ; is fometimes difpofed in lay 
 ers ; and, in fome fpecimens, has a granulated appearance. 
 
 TALKERDE, Werner; TALCITE^ Mr. Kirwan; LEPIS, Dr. 
 Walker. This fubftance occurs very frequently, indeed more 
 fo than the mica ; yet, as I am not well acquainted with the 
 names given to its admixture with other foflils, I Hill retain 
 the term Mica for the whole, in fpeaking in general. 
 
 Thefe three fub fiances are often conjoined, forming a fpe- 
 cies of flate ; in other examples we obferve only quartz and 
 mica conjoined, or quartz and talcite ; and, laftly, felfpar, in- 
 durated chlorite and hornblende add to its variety. In ge- 
 neral, the rock which thefe fubflances make is very com- 
 pact ; and often they are fo intimately combined, that it is 
 difficult to determine whether it be mica, talcite or chlo- 
 rite that is intermixed with the quartz. Frequently we fee 
 
 the 
 
A R R A N. 93 
 
 I 
 
 the quartz a~wanting, when the mica pafTes to the ilate of 
 ardeiia. 
 
 . Several kinds of this rock, particularly the quartzy, 
 have been ufed for the building of ovens and furnaces, on ac- 
 count of their great infufibility. No rock is more favourable 
 for metallic veins ; indeed, many of the richeft mining coun- 
 tries are formed of it : we may inflance the vaft mines of 
 Sweden, which are almoft entirely fituated in micaceous 
 fhiftus. 
 
 A R R A K 
 
A R R A N. 
 
 CHAP. VII. 
 
 Glen-Catacol, Glen-Erfay, Glen-Clachan, Shi/kin, Tory-Lin, Benin- 
 Head, Whiting Bay, Lamlajh Bay, Lamlafh I/land. 
 
 JL~1AVING glanced over the glens and flrata in the neigh- 
 bourhood of Loch-Ranza, I will now proceed around the ifland 
 by Glen-Catacol, which is about a mile and a half from Ranza. 
 The mores in this direction are bounded by cliffs, which are 
 neither very high nor rugged, but beautifully adorned with low 
 mrubs, giving a richnefs of appearance feldom obferved upon 
 the fhores of this ifland. The cliffs and mountains in the vi- 
 cinity are formed of micaceous fhiftus, of various degrees of 
 hardnefs, owing to its being more or lefs intermixed with 
 quartz. They are feparated from the fea by low beaches, of 
 confiderable extent, which, in forne places, are cultivated. The 
 entrance to the glen is bounded by lofty, precipitous moun- 
 tains 
 
A R R A N, 
 
 
 tains of micaceous mill us ; but this foou difappears, as the 
 glen changes its direction, running N. N. E. and S. S. W. .: 
 then the mountains are formed of granite llmiiar to that of 
 Goatfield. In feveral places of the glen fragments of bafalt oc- 
 cur ; demonftrating the prefence of veins traverfing the gra- 
 nite, as we have already obferved upon Caime-na-callich and 
 Glenrofa. Upon one fide of the glen we obferved a narrow 
 valley, into which we entered, but found that the granite was 
 fall the prevailing rock. At one place, indeed, I difcovered 
 great maifes of porphyry ; but I could not detect them in fitu. 
 It is probable, however, that it forms veins running in the 
 granite, as the quantity of debris is too fmall for fuppoiing the 
 exiftence of flrata. After a very fatiguing walk, . I reached the 
 top of the glen, when I obferved a confiderable plain, in 
 which is fituated a lake, about a mile long and half a mile 
 broad, which is named -Loch-Tan. It is bounded upon two 
 tides by lofty granite mountains ; but is open towards the 
 others ; one leading to Glen-Erfay, the other to Catacol. The 
 margin of this partakes much of the flerility of the furround- 
 ing fcenery : vegetation hardly mews its head : a few lichens 
 and tufts of heather are the only ornaments of which it can 
 boaft : 
 
 _______ A joylefs coafl. 
 Around a flormy lake, . 
 
 Yet 
 
56 A R R A N. 
 
 Yet here the grandeur and fublimity of the furrounding gra- 
 nite mountains, envoloped in clouds and mift, excited in my 
 mind a vaft variety of ideas ; for, 
 
 Surely there is a hidden power that reigns 
 'Mid the lone majefty of untam'd nature, 
 Controlling fober reafon. 
 
 Upon afcending the granite mountains on the eafl fide of the 
 loch, I obferved confiderable quantities of the debris of bafalt 
 upon the top of the mountains, mowing that the veins had 
 reached to the very fummit *. 
 
 I walked onward to Glen-Erfay, and, in my way, obferved 
 large blocks of a beautiful dark leek-green coloured pitchftone- 
 porphyry, remarkable not only for the number, but alfo for 
 the fize and beauty, of the cryflals of felfpar. I was not fo 
 fortunate as to find it forming a fixed rock in the neighbour- 
 ing granite mountains ; yet it is probable that future obfervers 
 may difcover it in veins, fimilar to that obferved on the fide of 
 
 Caime- 
 
 * SaulTure obferved fragments of greenftone upon the fummit of Mont Blanc j 
 very probably originating from a vein of greenftone which reached to the fummit 
 of this great mountain. Voyages dans les Alpes, torn. 7me, p. 280 288, 
 
A R R A 
 
 97 
 
 Caime-na-callich. Some mineralogifts will rather be inclined 
 to lufpect that it alternates with granite : as this is faid to be 
 the difpofition which it affects when among the granite moun- 
 tains of other countries. According to Charpenfcier j% who 
 made this obfervation, porphyry containing pitchflone alter- 
 nates with granite near MeifTen in Saxony. Dr. Mitchell, who 
 "was lately on the particular fpot described by Charpentier, in- 
 forms me, that he could not obferve any fuch alternation, and 
 therefore prefumes that the obfervation of Charpentier is erro- 
 neous. Having reached the lide of Glen-Erfay, I obferved it 
 taking its rife from the lower part of Caime-na-callich and 
 the neighbouring mountains, and running, in an irregular 
 .courfe, towards the fea. It is faid to be nine miles long, and 
 is reckoned the mofl extenfive glen in the ifland. Its fides 
 and bottom are formed of granite, which continues un- 
 til we come within a mile of the lower extremity of Loch- 
 Erfay, when flrata of micaceous and talcaceous fhiftus make 
 their appearance. Thefe ftrata continue to the entrance of the 
 glen on the fea-fhore ; and here they are covered and fucceeded 
 by red argillaceous fandflone andfandftone breccia. 
 
 4 Charpentier Mineralogifche von Churfachfen, 63. 
 
98 A R R A N. 
 
 As I had an opportunity, upon my former vifit to this ifland, 
 of walking along the more from Catacol to the entrance of 
 Glen-Erfay, I will now fliortly mention the nature of the rocks 
 that occur in this tract, and then continue the defcription oil- 
 wards to the other parts of the ifland. 
 
 From Catacol to Whitefarland, a farm belonging to Fuller- 
 ton of Kilmichael, the cliffs are low, compofed of micaceous 
 ihiftus, but defended from the action of the fea by intervening 
 fea-banks fimilar to thofe noticed between Catacol and Loch- 
 Ranza. Near to the farm of North Tundcrgay, I obferved a re- 
 markable vein of bafalt penetrating the micaceous fhiftus. The 
 micaceous fhiftus is much waved ; but, as it approaches the fide 
 of the vein, it lofes its mining glimmery appearance, breaks in- 
 to thick plates, and, where in immediate contact with the ba- 
 falt, it forms a compact kind of ardefia. The vein, as it rifcs 
 from the fea, is fairly croffed by a fpecies of micaceous fhiflus 
 approaching to breccia ; and here alfo the bafalt and micaceous 
 fhiftus are much jumbled together, and fome pieces of the vein 
 are apparently infulated in the micaceous fhiftus.. Here, then, 
 we have two facts ; the former, the apparent tranfition from 
 micaceous fhiftus to ardeiia ; the other, maffes of bafalt im- 
 merfed in. the micaceous fhiftus, in a fimilar manner to the ba- 
 falt I obferved embedded in the granite upon the eaft fide of 
 Glen-Rofa. At Whitefarland there is a considerable extent of 
 
 natural 
 
A R R A N. 99 
 
 
 
 natural wood, which adds greatly to the beauty of its appear- 
 ance, which is much heightened by the lofty granite mountains 
 that bound it on one hand, with the fea and long-extended 
 ifthmus of Cantyre on the other. From this to Imachar the 
 fame micaceous ftrata continue, forming beautiful cliffs and 
 coniiderable fea-beaches. At Imachar the micaceous fhiflus is 
 undulated, and traverfed with quartz, fo as to give the whole 
 a kind of maculated afpecl ; and it continues to form cliffs until 
 we come to the ftream which iffues from the entrance of Glen- 
 Irfa. Upon one fide of this flream I obferved primitive fhiflus, 
 but iipon the oppofite fide fandftone cliffs make their appearance. 
 Thefe cliffs have a confiderable beach interpofed between them 
 and the fea ; and the flrata of fandftone and fandftone breccia 
 are elevated at a greater angle than any I have obferved in the 
 other parts of the ifland. The retreat of the fea from thefe 
 cliffs is not only marked by the confiderable beach we have 
 juft mentioned, but alfo by the caves which are difperfed in 
 them. Thefe cliffs foon difappear, when porphyry is to be ob- 
 ferved ; but we can only trace it a little way, the covering 
 of grafs preventing any further examination. The country 
 is now low and flat, fo that we have an eafy walk to the houfe 
 of the Shifkin ; and the only rock I noticed was the red argil- 
 laceous fandftone, which I obferved in the bottom of feveral 
 burns : thus intimating that the whole ftrata over which I had 
 
 N 2 paffed, 
 
AURA N 
 
 palled, aita- leaving the porphyry, was fandilone. At the 
 Shifkin tlie land is low and flat. The mountains in the neigh- 
 bourhood have a different appearance from thofe about Loch- 
 Ranza -j. are lower ; their fides lefs precipitous ; in fhort, have 
 much of the general afpedl of thofe about Glencloy, all an- 
 nouncing a change in their competition. We have a good op- 
 portunity of determining the truth of this conjecture, in the 
 Clachen glen, which is but a fhort diftance from the Shifkin, 
 The fandflone flrata, which we have jufl mentioned as form- 
 ing the low country around the Shifkin, flretches up the glen 
 for a confiderable way. At one place, on the fouth fide, I ob- 
 ferved a confiderable flratum of limeflone, which is covered, 
 and even, in fome places, intermixed, with fandflone breccia ; 
 and, nearer the upper extremity of the glen, fhiflofe clay, 
 richly impregnated with iron, makes its appearance. As we 
 proceed upwards the glen becomes very deep ; and, upon the 
 north fide, confiderable rocks of clay-porphyry occur, appa- 
 rently covering the fandflone, as I conjectured may . be the 
 cafe at Glencloy and Corygills. As we approach flill nearer to 
 the upper extremity of the glen the fandflone difappears, when: 
 a fienite, fimilar to that at the head of Glencloy, is to be ob- 
 ferved, and, fo far as I could determine, rifes to the fummit 
 of the neighbouring hills, 
 
 About 
 
A R R A N, 1OI 
 
 About two miles N. \V. from the Shifkin, after pamng 
 through a moorifh flat, we come to Tormore, which is the 
 promontory of this plain. Here are cliffs of confiderable ex- 
 tent, which contain a range of extenfive caves, celebrated by 
 tradition as the reding place of Fingal, the father of our great 
 Oman, who, it is faid, ufed to retire here after the fatigues of 
 the chace. In the farther extremity of the greatefl, or what is 
 called the King's Cove, are a few fcratches, made by idle fi- 
 fhermen or fmugglers, which, by fome, have been referred to 
 the Fingalian age. 
 
 As the appearances at this promontory are very interesting, 
 I fhall make the defcription as diflincl; as poflible ; and, to be 
 regular, I fhall begin at the north-eafl end, or Machry Bay, 
 and fo on to Drumoodon point. The bay is of confiderable 
 extent ; and the fhore, all around to Irfa, is formed of fand- 
 flone. The bottom of the bay is a low fandy beach ; but, to- 
 wards Tormore, it rifes, forming cliffs, which are continued 
 all around to Rue-varey, or the columnar promontory, for the 
 fpace of about a mile and a half : and thefe cliffs are from forty 
 to one hundred feet high. Between the cliffs and the fea 
 there is a confiderable fandftone beach, which is remarkable for 
 the great variety and the number of veins that traverfe it, in 
 different directions : thefe, at firft fight, appear confufed ; but 
 
 a little. 
 
IO2 A R R A N, 
 
 a little attention iboii difcovers a beautiful and diflinct 
 difplay of a mofl curious difpofition of rock. As the pitch- 
 Hone veins are the principal objects of curiofity, I will defcribe 
 thefe firfl ; and, to make the detail accord with the engraved 
 plan, I will begin from the extremitv of the great pitchflone 
 vein as it rifes from the fea, ancl-ib trace it back to near Ma- 
 chry Bay. 
 
 The great vein of green-coloured pitchflone, D, as it rifes 
 from the fea, is feveral feet wide, has a confiderable inclina- 
 tion to the horizon, is (lightly bent in its courfe, and traverfes 
 the common red-coloured argillaceous fandflone. It has, for 
 fome yards, the character of a Jlratified vein ; that is, it con- 
 tains layers or flratulae of different fubflances depoiited in the 
 fame nfTure along with the pitchflone. Upon the fide of the 
 *ein next the fea, there is a layer, A, of a fubflance which appears 
 inclined at an angle of 60, dips in the fame direction with the 
 pitchflone D, and has a fimilar curve. It is not untike a com- 
 pact fandflone ; but it is probably of the fame nature with B 
 on the oppofite fide of the vein, only more altered by the ac- 
 tion of the weather and the fea. Upon the oppofite fide of the 
 pitchflone, we obferve a layer, B, which appears to be of the 
 nature of hornflone, or, rather, verging to quartz : it has a fi- 
 rnilar curve and dip with the pitchflone. Immediately befide it 
 
 there 
 
A R R A N. IO3 
 
 j 
 
 there is a thin layer of bafalt, C, which is decomposing in 
 balls ; and this, again, is boxinded by the common argillaceous 
 fandftone ftrata. The vein continues thus flratified for about 
 twenty yards, when the layers, A, B, C, appear to come nearly 
 horizontal, and foon they entirely difappear under the debris. 
 Further on, where the pitchftone is almoft free from the cover- 
 ing of debris, it appears to be bounded on both fides by the 
 common argillaceous fandftone ; yet this is doubtful, as there 
 may be finall portions of the other ftratula?, which the debris 
 prevents us from obferving. 
 
 At a little diftance from where the fandftone appears to form, 
 the fide of the great vein D, we obferve E, which is a vein of 
 r ock fimilar to that of B, is from fix to eight inches wide, and 
 is waved in its courfe. At fome diftance from this, there is a 
 vein of bafalt, P, about five feet wide, running nearly E. and 
 W. which is much the fame direction with the laft mentioned 
 vein. The next vein which we meet with is about thirty feet 
 feet wide ; runs N. W. and N. and N. E. and E. which is nearly 
 in an oppofite direction to the great vein., Upon one fide, there 
 is a layer, F, of a wax-coloured fubftance, intermediate between 
 hornftone and pitchftone ; next, is a layer, G, of high olive- 
 green coloured pitchftone, about two feet wide ; again, we 
 have a layer, H, about half a foot wide, of the fame pitchftone- 
 
 hornftone,. 
 
104 
 
 A R R A 
 
 hornftone as F; then, a layer of indurated clay, K; and, 
 after this, the whole vein is formed of bafalt, L. The 
 fandftone which bounds this vein, in place of being red, the 
 ufual colour, is partly a yellowifh-white colour. I endeavoured 
 to difcover its j unction with the great vein D, but without fuc- 
 cefs, owing to the great covering of debris : I obferved it, how- 
 ever, upon the oppofite fide of D, but at a diftance, entering 
 into the neighbouring fandftone cliffs. At a little diftance from 
 this, we meet with another remarkable vein : the fides, M, M, 
 are of bafalt * ; but the middle, L, is of breccia f. Still nearer 
 to Machry Bay, another curious vein is to be feen : it is about 
 eight feet wide ; the fides, P, P, are of fine white-coloured argil- 
 gillaceous fandftone J; next, are two layers, O, O, of bafalt ||, 
 
 which 
 
 * This bafalt does not differ from that from the fouth fide of Glencloy, 
 defcribed at page 53. 
 
 f This breccia is formed of varioufly-fhaped maffes of common and arena- 
 ceous quartz, and indurated clay, connected by a bafis which is only an agglu- 
 tination of fmaller particles of the fame kind. 
 
 t This fandftone only differs from the ilratified kind by its having a white 
 colour. 
 
 H This bafalt has a black colour j and 4ias, difperfed through it, cryftals of 
 .hornblende, calcareous fpar, aud iron pyrites : this laft, by decompofition, often 
 gives the whole a brown colour. 
 
A R R A N. IOJ 
 
 which decompofes in balls ; and the middle, N, is formed of a 
 rock which has cryflals of felfpar and rounded pieces of quartz, 
 immerfed in a bafis that feems one of the gradations from pitch- 
 done to hornflone. The laft vein, Q^, which I obferved run- 
 ning, in a crofs direction, to the great vein of pitchflone D, is 
 about ten feet wide, and entirely compofed of green-coloured . 
 pitchftone. 
 
 The great vein continues vifible for a little way after pafling 
 the vein Q, and is nearly of the fame diameter ; but, as we 
 approach very near to Machry Bay, it is not to be further tra- 
 ced, on account of the covering of debris. Near to its termi- 
 nation, however, I obferved the hornflone pitchflone fubflance 
 forming a layer upon one fide, and even, in fome places, 
 intermixed with it. 
 
 I have to regret that this interefting piece of mineralogy is 
 fo imperfectly detailed ; yet I trufl it will ferve to excite others, 
 better qualified, to give it a more particular examination. I 
 would particularly recommend an attention to the appearances 
 prefented by the junction and croffing of the veins ; which I 
 had not an opportunity of exploring, on account of the great 
 covering of debris : a hindrance which fome future aftion of 
 the fea may remove. 
 
 O The 
 
A R R A N. 
 
 The next objeft which claims our notice, is, the determina- 
 tion of the rektive pofition of the fandftone and porphyry. 
 The cliffs, befides the fandftone, of which they are principally 
 compofed, are, in fome places, varied by a clay-porphyry, very 
 fimilar to that of Glencloy ; with this difference, that the cry- 
 ftals, felfpar and quartz are larger. The porphyry, fo far as I 
 could determine, does not feem to lie on the fandftone, but 
 merely to fkirt it. Several bafalt veins are to be obferved tra- 
 veling it, in different directions. One vein, about feven feet 
 wide, runs through it in a perpendicular direction, and gra- 
 dually narrowing towards the top of the cliffs, when it is loft 
 among the fandftone that lies behind. Another runs more, in 
 a horizontal direction, and between the fandftone and clay- 
 porphyry. Another vein, which is nearer to Machry Bay than 
 the other two, is to be obferved running with porphyry on the 
 one fide, and fandftone on the other : it foon divides ; one 
 branch penetrating the porphyry, the other ^running between 
 the fandftone and porphyry. 
 
 To the \V. of the King's Cove, I obferved great mafles of 
 green-coloured pitchftone fcattered upon the more ; but I could 
 not difcover whether they belonged to the great vein D on the 
 other fide of the caves, or had been feparated from other veins 
 or ftrata. Upon the top of the cliffs, at the fame place, I ob- 
 ferved 
 
A R R A N, 
 
 107 
 
 ferved a variegated pitchftone, which was decompofed, in 
 fome fpecimens, almoft to a brownifh-white earthy powder, 
 cropping through the grafs j but I could not difcover whether 
 it formed a vein or ftratum. 
 
 From this to within a fhort diftance of the columnar promon- 
 tory of Drumoodon, the cliffs are of fandftone ; but, in fome pla- 
 ces, they appear covered with a porphyry : of this, however, I can- 
 not fay any thing fatisfactory. I obferved many bafaltic veins 
 traverfing this fandftone ; and, upon examining the connection 
 of the veins and ftrata, I found the bafalt and fandftone, at; 
 their junction, in feveral places, intermixed; and alfo the ba- 
 faltic veins, belides the angle they form with the horizon, had 
 a confiderable inclination of themfelves. 
 
 At a little diftance from the columnar promontory, I ob-- 
 ferved low, fhelving rocks of clay-porphyry, which extend be- 
 yond the point Rue- Varey on the one hand^ and ieem to be 
 connected with the porphyry on the other. The promontory 
 is a ftriking object ; is pretty high ; and cornpofed of red-co- 
 loured argillaceous fandftone, which is> covered by irregular 
 columns of a porphyry which, in fome places, has much refem- 
 blance to bafalt-porphyry, in others is evidently clay-porphyry. 
 This fact is a prefumptive proof that the conjecture I have 
 
 O a made*. 
 
io A R R A N. 
 
 made, with regard to the fituation of the porphyry of Glen- 
 cloy and Corygills, may be true. 
 
 Having pafTed Rue-Varey, which is the mod weftern point 
 of Arran, we came to the farm of Drumoodon, which is fitua- 
 ted upon the fea-iliore, with a confiderable fandy beach before 
 it, and, behind, the fandflone cliffs are ftill continued. Here 
 we find, refling upon the fandflone, a curious fpecies of rock, 
 having a tendency to fplit into columns ; but of which I cannot 
 give a determinate opinion, as I do not find any defcription, in 
 the mineralogical works I have confulted, that correfponds with 
 it. I have marked it, in the fliort defcription that is detailed 
 in the following chapter, as intermediate between bafalt and 
 fandftone, Thefe cliffs become gradually lower, and at length 
 difappear, being fucceeded by an extenfive beach covered with 
 fragments of the neighbouring rocks. After pafling this beach, 
 which forms one fide of the plain of the Shifkin, confiderable 
 cliffs now rife before us, which are formed of clay-porphyry of 
 confiderable height, but much fplit by the adlion of the wea- 
 ther, which gives an indiflincl idea of Gratification, fimilar to 
 the granite obferved in the Cory-Dain, at the head of Glen- 
 Rofa. Thefe cliffs contain feveral caves, but none of them are 
 of any confiderable fize ; and the fhore is covered with great 
 
 .maffes. 
 
A R 11 A N. 
 
 mafTes, which have been feparated from the cliffs by the ac- 
 tion of the fea and weather. Thefe mafTes have a peculiarity 
 of form, which characterifes the rock from which they have 
 been feparated. This remark may appear fanciful ; but feve- 
 ral circumflances lead me to imagine, that one, accuflomed to 
 obferve with attention the debris upon the fea-coafts, &c. may 
 often guefs as to the peculiar nature of the rocks themfelves, 
 by obferving the fhape of the fragments. The whole more, to 
 Tory-Lin, appears to be compofed of clay-porphyry, and in 
 foine places fandftone is to be obferved, and both are traverf- 
 ed with veins of bafalt. I picked up fragments of dark leek- 
 green-coloured pitchflone, in different places, among the debris 
 of the neighbouring rocks ; but had not leifure to determine 
 its fituation. From the Shifkin to Tory-Lin,there is a to- 
 lerable road ; which is a rarity in this ifland, and extreme- 
 ly agreeable to the traveller, after having fcrambled around 
 the more from Brodick Bay. The .land now becomes lower, 
 and has more of the rural appearance of the Lowlands of 
 Scotland : agriculture is followed with fome fpirit, and even 
 many of the fea-beaches are cultivated. 
 
 Tory-lin confifts of a few houfes, pleafantly fituated in a 
 hollow, at a little diftance from the fea fhore, and furrounded 
 
 with 
 
. 
 
 110 A R R A N. 
 
 with fandftone hills. In the burn which runs by the hoxifes, 
 I obferved veins of bafalt traverfing the fandftone in different 
 directions, and amongfl the bowlder ftones which cover its 
 bottom, fragments of a light blackifh green-coloured pitch- 
 flone prefented themfelves, (bowing the exiftence of veins or 
 flrata of that foflil in the neighbourhood. Upon the fhore a 
 curious fpecies of porphyry, (different from waeken-porphyry,) 
 makes its appearance, and feems to be traverfed with veins of 
 common bafalt, which are here of very great fize. 
 
 On my fecond vifit to Arran, I walked a-crofs from Tory- 
 Lin to Lamlafh harbour, which gave me an opportunity of 
 obferving a part of the iflands, with which I was before un- 
 acquainted. I will therefore ihortly mention what occurred 
 in that route ; before proceeding to mention the very few ob- 
 iervations I made on the fouthern part of the ifland. After 
 leaving Tory-Lin, we afcend for fome time over the ufual 
 red-coloured argillaceous fandftone, it at length difappears, and 
 the higher grounds are formed of porphyry. This porphyry 
 continues until we come to the farm of Achariach, when red- 
 coloured argillaceous fandftone is to be obferved in the bot- 
 tom of a burn, and is apparently travefed by a vein of white- 
 coloured fandftone. As we proceed onwards, we afcend fome 
 high grounds, where the porphyry again appears, and it now 
 
 continues 
 
ARRAN. HI 
 
 continues all the way to the hills upon the fide of Lamlafh 
 bay. Thefe hills are compofed of white-coloured fandftone 
 at the top, but lower down of common red-coloured fandftone. 
 
 The more from Tory-Lin to the Benin-Head, the mod fouth- 
 ern part of the ifland, is principally compofed of fandftone, 
 traverfed with veins of bafalt, which are fometlmes of great 
 fize, and run in a great variety of directions. The hills back 
 from the fhore appear to be entirely compofed of porphyry*, 
 but are not of any great height. The whole country to the 
 
 Benin-head is confiderably cultivated, and is here and there 
 diverfified with fmall villages, which give to the whole a pic- 
 
 turefque feature, which we have feldom an opportunity of ob- 
 ferving in this ifland. At the Benin-head, the cliffs are of 
 coniiderable height, and are compofed of fandftone, porphyry, 
 and bafalt. The porphyry and bafalt have a tendency to the 
 columnar form, and both are traverfed by bafalt veins, which 
 are often of a great fize. 
 
 From this to Whiting Bay, the cliffs are low, formed of 
 fandftone, and traverfed with bafalt veins, which run in a 
 
 great ' 
 
 * I find in my notes, that fienite is marked as one of the rocks of this part of 
 the country. I am now fomewhat doubtful of that fad, and will therefore leave it 
 as an objeft for future enquiry. 
 
AURA N.. 
 
 great \ ariety of directions. The hills, however, up from the 
 ihore,. now change their appearance, prefenting broad, bare> 
 perpendicular faces, fimilar to thofe which occur in all bafaltk 
 countries ; and upon examination, we find them to be com- 
 pofed of various fpecies of bafalt,* lying upon a red-colour- 
 ed fandftone, which is intermixed with grunerde, and a grey 
 thiftofe clay. This bafalt is often columnar, and the perpen- 
 dicular crags, being fcattered in various directions, and often 
 riling in 'groupes above each other, have a pleafing effecl:. 
 Near to Whiting bay, there are confiderable rocks of green- 
 ftone of nearly the fame fpecies with that found near Cory- 
 gills ; it is not in any confiderable quantity, and appears to 
 
 i 
 be the rarefl rock in the ifland. 
 
 At Whiting bay, the clifFs difappear, and are not to be ob- 
 ferved until we come to the entrance of Lamlam bay; in 
 their place we have an extenfive beach, bounded by gradu- 
 ally rifing. fandftone hills> much traverfed with bafaltic veins. 
 When the tide ebbs, the bottom of the bay exhibits a moft a- 
 ili^iifhing collection of bafaltic veins, which have been laid 
 
 bare 
 
 * v Stucke, a German chemift, on breaking a certain cellular bafalt, found the 
 cells to contain water. He analyfed 20 ounces of this watet, and found it to 
 contain fourteen and a half grains of filex. Stuck Unterfuch. 119, Ktfwan t Geo- 
 Ifigical Eflays, p. 
 
A R R. A N. j j ,j 
 
 bare 'by the action of the fea ; here they are to be feen run- 
 ning in every direction, meeting and crofTmg each other in a 
 nioft curious manner ; in fhort, this is one of the befh parts of 
 the ifland for obferving the various crofTmgs, &c. of thefe fingu- 
 lar appearances *. At the entrance of the bay of Lamlam, the 
 fandflone forms coniiderable cliffs, which continue a fhort way of 
 confiderable height, but are gradually lower as we approach the 
 village of Lamlam, where there is an extenflve flat beach. Thefe 
 cliffs are alfo traverfed with veins of bafalt, and in fome places 
 a few hundred yards from the more, I obferved many detach- 
 ed maffes of green pitchftone, indicating its exiftence in the 
 neighbourhood. 
 
 Lamlam bay, which is the befl harbour in the ifland, and 
 one of the beft in the Firth of Clyde, is of a femi-circular 
 fhape, and is formed in part by Holy ifland or the ifland of 
 Lamlam, which lies acrofs it, leaving two entrances, one from 
 the north, the other from the fouth, which laft is always pre- 
 
 P. ferred 
 
 * It will be fomewhat difficult to explain the appearance of fo many veins in 
 fo fmall a fpace of ground as Whiting bay, according to the Wernerian Theory. 
 For furely had all thefe been at one time open fiffures, the fandftone would not at. 
 the fame time have fupported itfelf. Sauflure, imagines, that this objection 
 be removed, by fuppofing, that thefe fifTur.es were formed fucccffively* 
 
II^. A R R A W, 
 
 fcrred by mariners. It is bounded upon the Arran fide by 
 hills of red and white fandftone, traverfed by bafaltic veins. 
 Upon the eaft fide of the bay, attempts have been made to 
 xlifcover coal, but without fuccefs. 
 
 Lamlafh or Holy ifland, is about three miles long, and half 
 a mile broad, precipitous on the eafl, alfo confiderably abrupt 
 on the weft fide, but the north and fouth ends are low. It is 
 compofed of red-coloured fandftone, which is in fome places 
 formed into fmall caves; one is celebrated for being the refi- 
 dence of the holy difciple of St. Columba, St. Mool-jos^ 
 or the fervant of Jefus. This fandftone is covered in ma- 
 ny places with a fpecies of bafalt, very fimilar to that 
 near Whiting bay, -and with difficulty diftinguifhable from 
 fandftone. I have been very much -at a lofs with regard to 
 the particular denomination to be given to this rock ; and I 
 muft ftill remain in doubt f. It forms in many places regular 
 columns, generally fix-fided, which rife range above range, giv- 
 ing a faint idea of the ftupendous icenery of St.afFa or Bo-fhe- 
 
 la, 
 
 T SauiYure mentions a bafalt much refembling fandftone, having . a prifmatic 
 rhomboidal form, and containing hornblende cryftals. Obfervations fur les 
 
 lines du Brifgau Journal de Phyfique, An Deuxieme, p. 329. Nay, 
 
 even fandftojie has been found columnar : thus the columnar boulaflein, fourul 
 In Iceland, is a fandflone. Eggert Olaf&er. Reife durch Iceland, 
 
A R R A N. lie 
 
 ' 
 
 la. Upon the weft fide, the columns are of greater fize than 
 upon the eafl, and the fame matter appears to form the fum- 
 mit of the ifland, which is reckoned about feven hundred feet 
 high. Upon the fouth-eaft part of the ifland, I obferved a 
 rock principally formed of cryftals of hornblende, which is 
 in fome places traverfed by bafalt veins *, and alfo ftratified 
 with the common fandftone ; and towards the fouth-weft ex- 
 tremity, bafalt veins are feen traverfing the fandftone* 
 
 P 2 
 
 * This bafait has a very great fpecific gravity, owing to its being abundant ii* 
 iron> 
 
A R R A N. 
 
 CHAP. VIII. 
 
 Dcfcription of the Foffils^ occurring in the preceding Chapter. 
 
 PITCHSTONE F rom Tormore. 
 
 JL HE following feries of foflils affords us a curious exam- 
 ple of the gradations, which we often obferve between the 
 different kinds of rock. Thefe gradations were either over- 
 looked, or but vaguely underftood, until the time of Werner, 
 who by the beautiful difcovery he made in thus tracing the 
 fteps of nature, attracted the attention of mineralogifts. An e- 
 minent mineralogift of our own country, has made great pro- 
 grefs in this interefting enquiry, and it is to be hoped, he 
 will foon gratify us with the refult of his labours. 
 
 N? 
 
A R R A N. 
 
 No. I. 
 ^/row the great vein D, 
 
 Colour. Brownifh. 
 
 LuJIre. Little glancing, and greafy. 
 
 'Tranfparency. None. 
 
 Frafture. Uneven, approaching the fplintery, 
 
 Hardnefs. Gives a few fparks with fteel. 
 
 Quartz, and a reddifh fubftance like garnet is difperfed 
 through it. 
 
 N II. 
 PITCHSTONE pajffing to Homjlone. 
 
 Colour. Light wax yellow, yellowifh green, weak reddifh 
 
 brown. 
 
 Lujlre. None. 
 Tranfparency. None. 
 
 Frafture. Even, fplintery, fometimes uneven. 
 Hardnefs. Hardly touched by the knife. 
 Smell. Gives a ftrong earthy fmell when breathed on. 
 Fufibillty. At 55? was covered with a flight enamel 5 at 69? 
 
 became 
 
)l8 A RR AN, 
 
 t 
 
 became white, {lightly foftened, and was then fomewhat po- 
 rous. A fragment from a fix-fided' column foftened at 81, and 
 at 1 1 8 a compact brown vitreous mafs was formed, which 
 had interfpeffed white grains. 
 
 By decompofition it acquires a white, and in fome varieties 
 a brick-red colour. It has difperfed through it cryflallifed 
 and amorphous quartz, chalcedony, a very few cryflals of white 
 felfpar, calcareous fpar, and alfo minute dark leek-green-co- 
 loured cryflals, probably pitchflone. 
 
 N III. 
 
 Foffil which appears pretty nearly of the nature of Horn/lone^ or 
 rather verging a little to Quartz -from thejlratulum B. 
 
 Colour. Pale blackifh brown ; or, dark grey, approaching to 
 
 black. 
 
 Lujlre. Very little glancing. 
 Tranfparency. A very flight degree at the edges.. 
 Fratfure. More or lefs fine fplintery, and very compact. 
 Hardnefs. Gives fire plentifully with fleeL 
 
 Pieces of quartz are difperfed through it, as in the former j 
 and a few cryftals of felfpar now and then occur. 
 
A R R A N. 1 19 
 
 N IV. 
 
 Foffil Jlill more nearly approaching to Quartz, which is intermixed 
 with the green pitch/lone of the great vein D. 
 
 This fpecies of rock differs little in colour from the prece- 
 ding ; but has more luftre and tranfparency, and is a little 
 harder. It acquires a white crufl by the action, of .the weather, 
 
 It has alfo, interfperfed, cryflals of quartz. 
 
 
 
 -OBSERVATIONS. 
 
 Thefe different gradations are all to be obferved in the fame 
 vein, and appear to graduate 0r pafs into each other. Thus, 
 the firfl, or brownifh-coloured pitchflone, by its little luflre, 
 feems verging to the fecond ; and, in reality, we often obferve, 
 in'the^fame fpecimens, the one pafTmg into the other. The 
 pitchftone-hornftone fubflance, N II. as its name implies, has 
 partly the character of the pitchflone, and partly that of horn- 
 ftone. The degree of fufibility intimates that it is fenfibly dif- 
 ferent from the pitchflone, yet not fufficiently refractory for 
 hornftone. Klaproth found a fubftance of this kind fufible ; 
 and Mr. Kirwan mentions a greenifh-white hornftone, from 
 -Lorraine, which, from its. being fufible, feems analagous to this. 
 
 We 
 
I2O A R R A N. 
 
 We are fometimes fo lucky as to find fpecimens where the 
 iecond pafles into the third j and often we obferve the third 
 pafling to the fourth. 
 
 Thefe four kinds of rock, then, prefent to us a complete 
 gradation from pitchftone to hornftone ; and we have a few 
 fteps towards quartz. In other countries, we have accounts 
 of nearly fimilar appearances ; and thefe I may fhortly men- 
 tion, as they will add frefh intereft to the detail we have now 
 given. Reufs informs us, that he obferved pitchftone pafling, 
 by various ftages, to hornftone, at Garfeback, near Meiflen *. 
 Efthner remarks, that the Saxon pitchftone pafles fometimes to 
 hornftone "f. and Mr. Kirwan, in his Elements of Mineralogy, 
 obferves that it pafles to hornftone. 
 
 CLAY PORPHYRY, vuben pafmg to born/lone Tormorc. 
 
 Colour. Greyifh. 
 Lnjire* None, 
 
 I'ran- 
 
 * Sammlung Naturhiftorifcher Aufsatze, &c. von Franz. Ambros Reuls, 
 362. 
 
 f Efthner, Mineralogie, JB. ii, 445. 
 
A R R A N. 121 
 
 franfpartncy. A little at the edges. 
 FraSfure. Even, pafling to the fine fplintery. 
 Hardnefs. Gives a few fparks with fleel. 
 
 
 
 It contains, immerfed in the bails, cryflals of common, red 
 felfpar, and white felfpar approaching adularia. The cryflals 
 are of confiderable fize ; and this is one of the principal di- 
 ftinclions between this fpecies and fome of thofe found in 
 Glencloy. It decompofes, in the form of a brick-red cruft, fi- 
 milar to fome of the flones which are intermediate between 
 pitchflone and hornflone. 
 
 In other fpecimens, the porphyry, as it comes in contacl: 
 with the veins of bafalt, has a bafe coniiderably refembling it ; 
 and at the columnar promontory of Drumodoon, the fpeci- 
 mens often cannot be diflinguifhed from what is called trap- 
 porphyry. 
 
 A fubflance intermediate between fandjlone and wacken, having a 
 tendency to the columnar form Farm of Drumoodon. 
 
 Colour. Yellowifh, 
 Lujlre. None, 
 
 Tran- 
 
122 A R R A N 
 
 Tranfparency. None. It feels much like a fandftone. 
 
 Frafturc. Even earthy, with the appearance of rounded con- 
 cretions. 
 
 Hardnefs. Gives a few fparks with fteel : but it contains con- 
 fufed fragments of quartz, which may have been the caufe 
 of this. Emits a flrong earthy fmell, when breathed upon *. 
 
 Fttjibiltty. Melted at 79* 
 
 OBSER- 
 
 * Lampadius has difcovered that hornblende contains charcoal diffufed thro* 
 it ; and Mr. Kirwan has down that fome fpecies of pitchftone contain it. It ia 
 conjectured that it may exift in other foffils, and caufe the peculiar earthy fmell 
 which we perceive by breathing upon them. 
 
OBSERVATIONS TO BE MADE, 
 
 FOR THE FARTHER ELUCIDATION OF THE 
 
 MINERALOGICAL HISTORT OF ARRAN. 
 
 VEINS. 
 
 I. JL O examine the bafalt, wacken, and pitchftone veins, 
 (which occur in fo many parts of the ifland,) with a view to 
 difcover if they be Jlratified. "We fhould defcribe accurately 
 the difpofition of the ftratulse of fuch veins, as it will enable us 
 to determine their relative antiquity : thus, according to Wer- 
 ner, the parts nearefl the fides of a vein are the moft antient, 
 thofe in the middle the moft modern, and the intermediate of 
 a middle age. 
 
 II. In the examination of veins, it will be of confe- 
 quence to obferve how they crofs each other ; which, Mr. 
 
 Werner 
 
124 A R R A N. 
 
 Werner remarks, will enable us to determine tlieir rela- 
 tive antiquity : thus, if two veins crofs each other, the 
 moil modern is that which croiTes the other ; and, of two 
 veins, the one which interrupts or flops the other is the 
 mofl antient. 
 
 III. To examine carefully the country in the vicinity of 
 veins, fo as to determine if there be any beds of a matter fi- 
 milar to that which fills the veins. It follows, from Mr* 
 Werner's theory, that we mould generally obferve fuch ap- 
 pearances. 
 
 IV. To examine if the fides of the veins be more or lefs 
 hard; where in contacl with the granite, micaceous fhiftus, 
 porphyry, fienite, or fandflone. 
 
 V. To examine the bafalt, and other veins, with a view 
 to obferve whether they contain petrifactions, or even wood 
 unaltered j alfo, if they contain boulder flones. 
 
 STRATA. 
 
A & X' A ft. 12? 
 
 STRATA. 
 
 VI. To determine the direction and inclination of all 
 the flrata throughout the ifland ; fo as to know whether 
 they have much the fame general arrangement, and if they 
 are frequently fituated in a fimilar manner with the flrata at 
 the mouth of Loch-Ranza. 
 
 VII. To examine particularly the flrata of fienite ; fo as to 
 difcover its connection with the granite, porphyry and mi-* 
 caceous fhiflus. 
 
 VIII. In examining the great glens, as Glen-Rofa, Sa* 
 nicks, &c. it will be of confequence to examine very particu- 
 larly as to the difpofition of the granite in flrata ; thus either to 
 confirm or refute the obfervations on the flratification of the 
 granite, 
 
 IX. To difcover whether the porphyry, which is ob- 
 ferved among the granite mountains, be difpofed in veins 
 or flEata,. 
 
 X. To 
 
1 2(5 
 
 X. To endeavour to difcover the fituation of the horn- 
 blende and paliopetre which is obferved in blocks at the en- 
 trance of Glen-Rofa. 
 
 XI. In traverfing the hills of micaceous fhiftus, to be care- 
 ful in obferving if any rocks of trap formation occur in 
 
 Jlrata. 
 
 XII. To determine the pofition of the breccia, with regard 
 to the other rocks, at the head of Glencloy; and alfo, to 
 examine, more particularly, the extent and pofition of the brec- 
 cia of South Glen-Sanicks. 
 
 XIII. To examine very particularly the appearance of the 
 granite, at its junction with the micaceous fhiftus and ardefia, 
 in different parts of the ifland. In this invefligation it will be 
 necefTary to obferve, i. If the ihiftus, where in immediate con- 
 tact with the -granite, be not harder than it is at a diftance, 
 2. If veins of granite are to be obferved flretching from the 
 granite, and traverfing the fhiftus. 3. If the granite veins have 
 the fame grain with that of the granite of the neighbouring 
 ^mountains. 4. If the granite and fhiftus be irregularly inter- 
 mixed at their jun&ion, 5. If the granite and fhiftus ever 
 
 alternate 
 
A R R A N 
 
 alternate with each other. This Werner confiders as a rare ap- 
 pearance. I have not obferved it in Arran. 6. If the mica- 
 ceous fhiflus, where it covers the granite, can be obferved 
 gradually changing its character, and at laft, where in junc- 
 tion with the granite, not diflinguifhable from it : a fact 
 which has been obferved in other countries, and demon- 
 flrative of the granite and fhiftus being formed nearly at the 
 fame time. 
 
 BUTE. 
 
BUTE. 
 
 CHAP. IX. 
 
 Outline of the MINERALOGY of the I/land of Burs; with Obf cr- 
 eations upon the Formation of the Bed of the CLYDE, and an 
 Account of the Route from Burs to the I/land of JURA. 
 
 A HIS ifland is about eighteen miles long ; and the broadeft 
 part, extending from eaft to weft, is five miles. It is feven 
 miles diftant from the ifland of Arran ; but is feparated from 
 the diftridl of Cowal by a channel which is only about half 
 a mile broad, and, in fome places, fixteen fathoms deep. To- 
 wards the north end it rifes into hills of confiderable height ; 
 but thefe are neither fumciently high nor extenfive to afford 
 fcenes fo fublime as thofe which charadlerife the moun- 
 tains of Arran. The fbuthern part of the ifland is, in general, 
 (excepting at its mofl fouthern extremity,) low, well cultivated, 
 and, in feveral places, beautifully ornamented with wood, par- 
 ticularly 
 
U T E, 
 
 I2 9 
 
 ticularly near to Mount-Stewart, the charming feat of the 
 Marquis of Bute. Although this ifland be deftitute of fine 
 mountainous fcenery ; yet, the extenfive cultivation, and the 
 general appearance of buftle and life, form a ftriking contraft 
 to the lone waftes of the ifland of Arran. 
 
 Rothefay, the only town in the ifland, is pleafantly fituated 
 upon the fhore of a confiderable bay of the fame name. It is 
 principally fupported by the herring fimery, and a very confi- 
 derable cotton manufactory. 
 
 The ifland feems to be traverfed by three irregular vallies, 
 which run from eaft to weft. One crofles the ifland at the 
 town of Rothefay ; the fecond at Kaimes Caftle, in the north"; 
 and the other at Cil-Chattan, in the fouthern part of the 
 ifland. 
 
 The mineralogy of this ifland, fo far as I examined it, does 
 not appear to be particularly interefting : but a clofer invefti- 
 gation may difcover many things which efcaped my notice ; 
 as I examined it in very unfavourable weather, and, befides, 
 had the misfortune to lofe the fpecimens I had collected. 
 
BUTE. 
 
 The whole of the iiland to the north of Rothefay is compu- 
 ted of primitive rock, which rifes into confiderable hills about 
 Kaiines Caflle, the feat of Lord Bannatyne. This half of the 
 ifland is pretty nearly fiirrounded by the neighbouring land of 
 Cowal, fo that the fea can have little power over its fliores, 
 which are indeed very low \ but the narrow channel, as I have 
 already remarked, is very deep. The flrata, in general, are, 
 micaceous fhiflus, ardefia, and fhiftofe talc j and they alter- 
 nate, and pafs into each other. Sometimes we alfo obferve 
 chlorite ; which is either maflive, or forms a fpecies of flate ; 
 and not unoften I remarked quartz, more or lefs penetrated 
 with the chlorite, forming a dark-green-coloured {tone, fimilar 
 to that I found in Arran* In feveral places confiderable veins 
 of quartz are feeji, traverfing the flrata in different directions ; 
 and fometirnes they exhibit curious phenomena. I obferved 
 upon the fea-fhore, about a mile and a half fouth of Kilmi- 
 chael ferry, a vein of quartz which deferves to be particularly 
 noticed. As it rifes from die fea, it is very narrow; but it 
 ibon becomes wider, and then divides into feveral confidera- 
 ble branches, which traverfe the flrata in different directions. 
 One of thefe branches prefents an appearance fimilar to that 
 obferved in Glenrofa, in the ifland of Arran, and defcribed at 
 pages 38, 39. This branch, having traverfed the flrata for feveral 
 feet, is interrupted by a mafs of micaceous fhiflus ; but it a- 
 
 gain 
 
., BUTE* 
 
 gain appears at a little diflance, and {till in its former direction. 
 MafTes of micaceous fhiftus are alfo to be obferved in the 
 midfl of the quartz vein. The appearance of a mafs of mica- 
 ceous (hiflus, which is a fufible flone when compared with 
 quartz, in the midft of a quartz vein, muft be confidered as 
 decifive againfl the theory of Dr. Hutton : for it is impoflible 
 to fuppofe that it mould remain unaltered in a heat capable of 
 melting quartz, or keeping it in a foft ftate. 
 
 The bafaltic veins, which occur fo often in Arran, are alfo 
 pretty common in this ifland, and are found from two to 
 ten feet wide, traverfing the primitive flrata in various di- 
 rections ; and I even noticed them upon the top of the high- 
 eft hills. 
 
 % 
 
 Near to Lord Bannatyne's caftle there are feveral Hate quar- 
 ries, which have been worked for fome time, and are ftill con- 
 tinued. Thefe flates, however, are not fo much ufed as thofe 
 from Eafdale, which are, even here, preferred for economical 
 purpofes. In fome parts of Germany, as at Ruhla *, they em- 
 ploy a compact micaceous fhiflus for the roofing of houfes ; 
 
 R 2 and 
 
 * Voight Mineral Reifert durch das Herzogth. Weimar. Th. 2. Se. 24. 
 
BUTE. 
 
 and it is preferred to fame kinds of ardefia, from its great du- 
 rability. Probably fome fpecies of micaceous fhiftus, equally 
 ufeful with that ufed in Germany, may be found among the 
 hills in the northern parts of the ifland. Mr. May, the cham- 
 berlain of Bute, informed me, that trials had been made for 
 lead in the northern parts of the ifland, but without fuccefs. 
 This I reckon no fatisfadlory proof that lead is not to be found 
 in the ifland ; as, in all probability, the perfons, employed to 
 inake the trials, were but little verfed in the bufinefs. 
 
 The north fide of Rothefay bay is entirely compofed of pri- 
 mitive rock, fo is alfo the north lide of Scalpa bay, which is 
 fituated upon the weft fide of the ifland, and nearly oppofite to 
 Rothefay ; but the fouth fides of thefe bays are compofed of 
 red argillaceous fandftone, and fandftone breccia. The junc- 
 tion of thefe primary and fecondary ftrata, is therefore to be 
 looked for in thefe bays. 
 
 The country between Rothefay and Cil-Chattan bay ; which 
 is the loweft, moft beautiful, and beft cultivated part of the 
 ifland ; is compofed of ftrata of red argillaceous fandftone, and 
 fandftone breccia, alternating with each other, and both are 
 traverfed with bafaltic veins. Upon the fhores, on both fides 
 of this part of the ifland, there are inland cliffs, fimilar to thofe 
 
 near 
 
BUTE. 
 
 near the north end of Arran, and in feveral places we remark- 
 ed banks of coral and fea {hells *, confiderably above the high 
 water mark. Thefe appearances, as well as thofe that occur 
 in Arran, are proofs of the land gaining on the fea. 
 
 From Cil-chattan bay, to the fouthern extremity of the ifland 
 called Gurroch-head, the face of the country is much altered ; 
 it now becomes nearly as high as in the north end, rifing into 
 irregular hills with abrupt perpendicular crags, that are al- 
 moft characleriftic of a bafaltic country. From the little op- 
 portunity I had of obferving this part of the ifland, I can only 
 fay in general that it is compofed of argillaceous fandftone,. 
 ftratified with bafalt, and traverfed by bafaltic veins. The 
 bafalt is fometimes columnar, and frequently contains much 
 hornblende. I was told that lime had been found in this part 
 of the ifland* 
 
 GENERAL 
 
 * Thefe banks are ufuallymade of the MUlepora polymorpha,. of which there 
 are many curious varieties. 
 
BUTE. 
 
 GENERAL OBSERVATIONS ON THE CLYDE. 
 
 Having now finifhed the outline of the mineralogy of the 
 iflands in the Clyde, I fhall make a few obfervations upon the 
 mode which nature appears to have followed in the forma- 
 tion of the bed of the river, the rocks and iflands. 
 
 The appearance of iflands in any quarter of the globe, na- 
 turally fuggefts to the mind, the idea of fome powerful agent 
 which has coiivulfed and broken the folid land, and formed 
 it into detached mafles. This opinion is not fanciful, for ap- 
 pearances, in many countries, fhow us, that the greater num- 
 ber of iflands have been formerly joined together, and mufl 
 have coiifthuted part of the adjacent continent. Thus, if we 
 examine the rocks upon the oppofite fides of the Clyde,, we 
 fhall find a great fimilarity in their nature, i. At Campbel- 
 town, which is only a few miles from the extremity of the 
 ifthmus of Cantyre, we obferve a fmall portion of fecondary 
 ftrata, which correfponds to that upon the oppofite coafl of 
 Ayrfhire. 2. The rocks upon the north and fouth ends of the 
 ifland of Arran correfpond exactly with the ftrata upon the 
 north and fouth fides of the Clyde. 3. The north end of 
 Bute is compofed of a fimilar rock with that of Cowal, and 
 
 the 
 
BUTE, 
 
 the fouthcrn extremity is compofed of the fame rock with the 
 Cumbray iilands, and thefe are of the fame rock with that of the 
 Largs, which is on the fouth bank of the river. Thefe fatfls 
 would fecm to indicate, that the oppofite banks of the Clyde 
 were at one time joined together, forming a very conflderabb 
 extent of folid land. If this be admitted, (and there feems 
 little doubt of its truth,) we muft now endeavour to difco- 
 ver what means were employed to break down the land. 
 
 Philofophers in their fpeculations on this fubjecl, have ge- 
 nerally mentioned two agents, which they imagine have 
 produced thefe ftriking and awful phenomena ; thefe are the 
 waves of the ocean, and earthquakes. The firft opinion 
 has been ftrenuoufly contended for by the late Dr. Hut- 
 ton, who affirms, that all bays, peninfulas, iflands, &c. have 
 been formed by the long continued action of the waves 
 of the ocean. This fpeculation at firfl fight feems very plau- 
 iible, but a more attentive confideration difcovers to us a very 
 exaggerated account of a comparatively partial operation ; and 
 this is indeed pretty evident from the following facts. The 
 channel between Italy and Sicily, is nearly the fame to day, as in 
 the time of the Romans. The ifthmus of Corinth has not been 
 vifibly altered for upwards of 2000 years. Scylla, of which 
 Homer has given a corre<5l defcription, is now nearly in the 
 
 fame 
 
136 
 
 BUTE, 
 
 fame flate as when he wrote *. The ruins of Beritta, the 
 favourite feat of Auguftus, are ftill to be obferved in their ori- 
 ginal fituation, upon the bank of the fea, and fo fituated, as 
 to be out of the reach of the waves f. Ancona built by the 
 Syracufians, is ftill by the fea fhore -f. Here, then, we have 
 inftances of the land refifting the powerful waves of the Medi- 
 terranean for upwards of three thoufand years. 
 
 Dr. Hutton who was aware of fome of thefe facts, remarks, 
 that " Our land is wafted by the fea ; and there is alfo a na- 
 " tural progrefs to be obferved, which naturally takes place 
 '* on this occafion ; for the coaft is found varioufly indented, 
 " that is to fay, more or lefs, according as the land is expofed 
 " to this wafting and wearing operation of the fea, and accor- 
 " ding as the wafted land is compofed of parts refifting, with 
 " different degrees of power, the deftroying caufe. The land, 
 " thus being worn and wafted away, forms here and there 
 " peninfulas, which are the more durable portions of that 
 " which had been deftroyed around ; and thefe remaining 
 u portions are ftill connected with the mainland, of which 
 " they at prefent form a part. 
 
 " But 
 
 * Spallanzani's travclls through Sicily, vol. 4. p. 172. 
 
 J Maundrell's travells from Aleppo to Jerufalem in 1669, 8tc. 
 
 t Maundrell, ibid. 
 
BUT*. 137 
 
 " But thole promontories and peninfulas are gradually de- 
 
 " tached from the mainland, in thus forming iflands, which 
 
 " are but little removed from the land. An example of this 
 
 " we have in Anglefey, which is but one degree removed from 
 
 " the ftate of being a promontory. Thefe iflands again, in 
 
 " being fubdivided, are converted into barren rocks ; which 
 
 " point out to us the courfe in which the loft or wafted land 
 
 " upon the coaft had formerly exifted. 
 
 " To be fatisfied of this, let us but look upon the weftern 
 *' coaft of Scotland, from the iflands of St Kilda to Galloway, 
 " on the one fide, and to Shetland on the other ; in this tradl, 
 *' we have every teftimony for the truth of the doctrine that 
 * c is confiftent with the nature of the fubjedl. The progref 
 '" of things is too flow to admit of any evidence drawn imme- 
 " diately from obfervation ; but every other proof is at hand ; 
 " every appearance correfponds with the theory ; and of every 
 " ftep in the progrefs, from a continent of high land, to the 
 " point of a rock funk below the furface of the fea, abundant 
 " examples may be found. We do not fee the beginning and 
 " ending of any one ifland, or piece of country ; becaufe the 
 " operation is only accomplifhed in the courfe of time, and the 
 " experience of man is only in the prefent moment. But man 
 * 4 has fcience and reafon, in order to underftand what has aU 
 
 .S " ready 
 
1^8 BUTE. 
 
 " ready been from what appears ; and we have but to open 
 " our eyes and fee all the ftages of the operation, although not 
 " in one individual object. Now, where the nature of things 
 " will not admit of having all and every flep of the progrefs 
 " to be perceived in one object, an indefinite progreflion in 
 " the various ftates of different objects, fhowiiig the feries or 
 " gradation from a continent to a rock, muft form a proof in 
 " which no deficiency will be found *" 
 
 This is very probably a correct delineation of the mode 
 which nature follows in altering the land, in fome few in- 
 flances ; but it cannot be general, as it would give an age to the 
 world quite inconfiflent with the Hebrew chronology; we 
 muft therefore confider it as untenable. It may be reckoned 
 tmphilofophical thus to fhelter ourfelves under the cover of 
 what has been, by fome, conlidered a traditional tale; when 
 facts and reafoning mould decide the truth of the argument. 
 I am by no means of this opinion^ and however unfafhionable 
 it may appear, I am firmly perfuaded, that any chain of reafon- 
 ing, that does not coincide with that chronology, is falfe. As 
 I have now proved the iiifufnciency of this theory, I might 
 proceed to confider the other ; yet to prevent the fceptica}, 
 from theufe of any undue argument, I will endeavour to mow, 
 that allowing Dr. Hutton's obfervations to be correct, they wiH 
 
 be 
 
 *> Theory of the Earth, vol, id. p. 265* 
 
BUTE. 
 
 be found quite infulHcient to explain the breaking of the land 
 of the Clyde, &c. From the account I have already given of 
 the nature of the ftrata upon both fides of the Clyde, it is evi- 
 dent, that the ocean, in its fuppofed action, has broken down 
 the hard primary ftrata, in preference to the fofter fecondary 
 ftrata ; a fact which ftrongly indicates the agency of fome 
 other power than the fea. Thus we find a confiderable por- 
 tion of the primary ftrata carried away from the north end of 
 
 / 
 
 Arran, and Bute, while the fecondary and fofter ftrata at the 
 oppofite ends of thefe inands, with the fandftone ifles the Cum- 
 brays, (land in the middle of the Firth, defying the rage of 
 the waves. Further, if we look at the map, we will find that 
 all the arms of the fea which are connected with the Clyde, 
 in place of being fituated in the fecondary ftrata, upon the 
 fouth bank of the river, are only in the north fide traverfing 
 a mountanious country which is entirely compofed of hard 
 primitive rock. The great depth of thefe lochs or arms of 
 the fea is very decifive againft Dr. Hutton's explanation. 
 Loch Fyne, at its upper extremity, nearly oppofite to Inveraray, 
 is about 60 fathoms deep : Loch Strevin, a fmall arm of the 
 Clyde, almoft inclofed at its entrance by the ifland of Bute, is 
 yet 38 fathoms deep : Loch Goyle, fituated further up the 
 Clyde, is, at its upper extremity, where it is not a mile broad, 
 about 37 fathoms deep : and Loch Long, near its head, is 28 
 
 S 2 fathoms 
 
t . BUTE 
 
 tatlioms deep. Thefe lochs are far removed from any viol- 
 ent aclion of the fea, or of currents ; fo that it is impoffible 
 that they could have been formed as Dr. Hutton conjectures, 
 allowing millions of ages for the purpofe. 
 
 The other opinion which we have mentioned, viz. " that the 
 land has been often fubmerged and broken by earthquakes," 
 ieems to afford us a lefs improbable explanation of the prefent 
 itate of the Clyde, than that advanced by Dr. Hutton. The fre- 
 quent occurrence of earthquakes, in the different quarters of the 
 globe, affords us numerous inflances of the fubmergence and 
 breaking of the land : yet we are acquainted with none fo ex- 
 tenfive as that of the Clyde. This, however, is of little impor- 
 tance ; as .it is not improbable, that thefe cataftrophes were 
 more frequent at a former period, than now. It would extend 
 thefe obfervations to a great length, were I to enter into a de- 
 tail of all the effects of earthquakes ; I mall therefore only fe- 
 lecl: a few facls as illuftrative of the prefent opinion. In 1692, 
 when the town of Port-Royal, in Jamaica, was deflroyed by 
 a dreadful earthquake, vafl maffes of land were funk far be- 
 neath the level of the fea, and mountains of confiderable ex- 
 tent funk down, leaving In their place extenfive lakes. In 
 1693, the ifland of Forca difappeared, being fwallowed up by 
 the ocean during a tremenduous earthquake. In 1678, there 
 
 was 
 
B U T 2. 
 
 was a great inundation in Gafcony, caufed by the finking of 
 a part of the Pyrenees : the mountains having difplaced the 
 waters, which exift in the cavities that are contained in the 
 bowels of the earth. In the late moft awful earthquakes that 
 have ravaged Peru, large mountains have been divided into 
 two parts and feparated ; others funk down, when large and 
 often bituminous lakes hare rifen in their place ; and laftly in 
 the earthquakes that devaluated Calabria, there are inflances of 
 mountains finking into the bowels of the earth *. 
 
 Thefe facts entitle us to conclude, that at fome former pe- 
 riod, this country was convulfed by great earthquakes, when 
 the beds of the Clyde, and its numerous lochs were formed, by 
 the fubmergence of the folid land : at the fame time Arran, 
 Bute, &c. received their infular form, being part of the land 
 that had efcaped the power of the earthquakes. Thefe iflands, as 
 well as the lands on both fides of the river, have, no doubt, 
 fince that period, experienced fome alteration from the long 
 continued action of the weather and the waves of the ocean. 
 
 Route 
 
 * The earthquake that was felt in Canada, in 1663, overwhelmed a chain of 
 mountains more than three hundred miles long. Clavigero r s hiftory of Mexico, p, 
 3Zi.- Kirwan's Geological EiTays, p. 500, 
 
I4'2 FROM BUTE TO }URA. 
 
 Route from the IJland of BUTE to the I/land of J 
 
 In travelling from the ifland of Bute to the Weftern Ifles, 
 we have the choice of different tracks, as may be feen from the 
 map. That which we purfued, although not the mofl conve- 
 nient, was yet interefling, as it allowed us to glance at a confi- 
 derable extent of highland country. 
 
 Having examined Bute as much as circumflances would per- 
 mit, we croffed the Kyles to a fmall houfe called the Kerry, fi- 
 tuated in the diftrict of Cowal. In cromng, we perceived, at a 
 diftance, feveral boats, filled with men drefTed in black, flowly 
 rowing up the found. So unexpected an appearance did not 
 fail to attract our attention ; and we were told that it was a fune- 
 ral proceflion to a burying-place in the adjacent mountains of 
 Cowal. Sxirely we could have hardly witnefTed a more flrik- 
 ing fcene. Mortality is at all times awful ; but it was here 
 prefented to us in a mofl impremve manner. The wild and 
 lofty mountains riling from the fides of the channel ; the ak 
 mofl perfect flillnefs of the water, which could be faintly heard 
 dying away along the more ; the univerfal filence, not even 
 diflurbed by the fcream of fea-fowl feemed as if nature was 
 
 unwilling 
 
FROM BUTE TO JURA. 
 
 unwilling to difturb the performance of the laft and melan- 
 choly fervices to the dead. 
 
 At the Kerry, the more is adorned with fweetly-rifing natu- 
 ral wood ; fo that we left it with regret, to traverfe a country 
 where grey, rugged mountains, and brown heaths, are the on- 
 ly objects to which our attention could be directed. Having 
 walked for about five miles through a dreary mountainous 
 country, principally compofed of micaceous fhiftus, interfperr 
 fed with chlorite, and traverfed with quartz veins ; we came 
 to the next ferry-place, which is fituated upon the banks of 
 Loch-Fyne, We crofTed from this to Eaft Tarbet, a diftance 
 of about nine miles ; and obferved the mountains on both 
 fides of the loch, all the way to Loch-Gilp Head ; having the 
 fame general appearance, and being probably compofed of 
 fimilar rocks with CowaL 
 
 Eafl Tarbet is fituated upon the narrowefl part of the penin- 
 fula of Cantyre ; for it is here only about two miles to the fea 
 on the weft fide, which is called Weft Tarbet. There is a tole- 
 rable road from the eaft to the weft fide ; which is of fome ufe, 
 as this is not only the principal thorough-fare to the iflands of 
 Ifla and Jura, but boats coming from the Weftern Iflands have 
 their; cargoes unloaded here, and then are drawn acrofs the 
 
144 FROM BUTE TO JURA. 
 
 ifthmus, in preference to the circuitous and dangerous voyage 
 by the Mull of Cantyre. It was once propofed to cut acrofs this 
 narrow neck of land ; but the bad ground at WeftTarbet inclined 
 the canal company rather to cut a canal from Crinan to Loch- 
 Gilp Head, through a more confiderable track of ground, but 
 reckoned more favourable for {hipping. The canal is now far 
 advanced ; but it is very probable that its utility will by no 
 means coincide with the fanguine expectations that have been 
 raifed, by the company, and the country in general. 
 
 The country, about Eaft Tarbet, is bleak and rugged. The 
 hills rife to a confiderable height ; and are compofed of mica- 
 ceous fhiftus in the lower part, but gneifs is to be obferved to- 
 wards the fummit, and now and then indurated chlorite is 
 found among the debris. Weft Tarbet prefents a more pleafing 
 fcene, from the natural wood that grows there with confidera- 
 ble exuberance. 
 
 From Eaft Tarbet I now continued my journey towards the 
 ifland of Jura, along the banks of Loch-Fyne, which is adorned 
 with natural wood, giving a rich and picturefque effect to the 
 high cliffs that rife above the road. The ftrata are, in general, 
 micaceous fhiftus, in fome places alternating with confiderable 
 of hornblende rock, and traverfed by bafaltic veins : and 
 
 I was 
 
FROM BUTE TO JURA. 145 
 
 I was told that confiderable limeftone quarries were opened a- 
 inong the neighbouring hills, and confequently muft be primi- 
 tive limeftone. In many places we obferved perfons cutting 
 down the wood, for the purpofe of making charcoal for the ufe 
 of the iron forge near Oban. This is to be regretted ; for, in a 
 morttime, the whole wood will be deftroyed, and the country 
 deprived of one of its greatefl ornaments ; and merely for the 
 fupply of the working of an iron furnace, that probably might 
 be carried on equally well by a carefully-carbonized peat. 
 
 Having walked for feveral miles along the bank of the loch, 
 we now changed our courfe, and croffed through a long, dreary 
 moor, and over hills, when we defcended to the plain at the head 
 of Loch-Kilifled, The rocks are, all the way, of micaceous fhif- 
 tus, which is, in many places, quite disintegrated, the loofe mica 
 forming banks feveral feet thick. This mka, if free from iron, 
 might be of confiderable value ; as we find Mr. Wedgewood ufing 
 the fine white mica of Cornwall for the manufacture of porce- 
 lain and his very .ufeful pyrometers J. It is therefore worthy 
 the attention of the proprietors to examine the neighbouring 
 country, where probably confiderable quarries of colourlefs 
 
 T mica 
 
 4: Journal dcs Mines, No. 3. p. 119, 
 
146 FROM BUTE TO JURA. 
 
 mica might be found. At the head of Loch-Kilifled I obferved 
 a confiderable ftratum of blue-coloured, granularly-foliated 
 limeflone, ftratified with micaceous mifhis. The micaceous 
 fhiftus is here- frequently mixed with felfpar, forming a fpecies 
 of gneifs difficultly diflinguifhable from fandflone. 
 
 After leaving this plain, we had a difficult afcent for a confi- 
 derable way, but the tedioufnefs of the track was a little relieved 
 by the natural wood through which We pafTed ; tliis, alfo, fooii 
 difappeared, when brown mofTes, and grey, bleak hills, were 
 again characteriftic of the country. Having walked for feveral 
 miks through this dreary and defert fpot, we were fuddenly 
 flopped upon the brow of a hill, from which we had a view of 
 the grey, fteril mountains of the mainland, rifing into various 
 rugged forms, and intermixed with lochs, thus preferring a 
 wild and defolate feene. Soon afterwards, we came in fight of 
 t&e rugged iftand of Jura, the ifland of Ifla, and, farther diflanr, 
 the mountains of Mull. Thefe we viewed with much pleafure, 
 as they were foon to be objects of our particular attention. 
 We now dtefeendfed from the mountains to the fea-fhore ; where 
 we obferved' an Id, gloomy, rainou& building, called Caflle 
 Sweki, fituated in a wretched-looking country. Even the few 
 inhabitants we faw, had fomething fo melancholy and deprefTed 
 in their appearance ; their miferable huts were in fuch unifon 
 
 with 
 
FROM BUTE TO JURA, 147 
 
 with the fcenery as to occafion in us an unufual lownefs of 
 fpirits. We haflened, therefore, from this fpot, and crofTed a 
 fmall ferry, and then walked about three miles to the more op- 
 polite the ifland of Jura. The ilrata, all the way from Kilifled 
 to this place, feem to be principally micaceous fhiflus, fre- 
 quently pamng to talcaceous fhiftus. 
 
 We here were fortunate in getting a boat, in which we pafTed 
 to the ifland of Jura. 
 
 We now examined a part of this ifland, and then crofled to 
 Ifla, where we remained a few days ; and again returned to 
 Jura, previous to our voyage to the Slate Iflands. As it would 
 be irregular, and little fatisfadlory, to detail the obfervations in 
 the exact order in which they were made, I prefer nril giving 
 an account of Ifla, and then of Jura. 
 
 T a ISLA 
 
2SLA AND JURA. 
 
 CHAP. X. 
 
 Abftraft of the. Mineralogy of the I/lands ISLA and JURA, 
 
 I SLA. 
 
 JL HIS ifland is thirty-two miles long, and, in fome places, 
 nearly as broad. It is the mofl foxithern of the JEbudse, or 
 Hebrides ; and its name is traditionally derived from Ilia, the 
 daughter of one of the kings of Lochlin, or Norway, who was 
 buried in the parifh of Kildalton. Dr. Campbell, in his Politi- 
 cal Survey of Great Britain, remarks that it is the Epidium In- 
 fula of Ptolemy ; and he imagines (erroneoufly, however) that 
 it is denominated Ifla, or The Ifle, as being the feat of govern- 
 ment when the Weftern Iflcs were ruled by the princes 
 of the liles. 
 
 It 
 
It approaches fomewhat to a fquare fhape, and iu much in- 
 terfected by the fea, in particular by two confiderable lochs, 
 one on the weft fide, called Loch Graynard, the other upon the 
 fouthern extremity, called Loch-in-daal. It is bounded upon 
 the N. E, by the rugged and fteril iiland of Jura ; on the E. by 
 the ifthmus of Cantyre ; towards the S. it is feparated only 
 about 20 miles from Ireland ; but on the W. it is expofed 
 to all the violence of the Atlantic Ocean* 
 
 The cliffs around the coafls of the ifland are, in foine places, 
 of confiderable height, particularly at Macarthur's Head, where 
 they rife with great grandeur and magnificence. The mores 
 are often covered with immenfe mafles which have fallen from 
 the neighbouring cliffs ; but, in other quarters, the cliffs difap- 
 pear, when we have fhores bounded by confiderable fundy 
 beaches. Beds of cailloux roules, or boulder flones, are to be 
 obferved upon the more, but placed a confiderable diftance 
 above high-water mark ; and in the fpace of ground between 
 the two lochs juft mentioned, there is an extenfive links, or 
 down, where we find, under the thin covering of grafs, fand, 
 boulder flones, and fhells. Thefe appearances, which are proofs 
 of the retiring of the fea from the land, are to be feen in many 
 parts of the Weftern Iflands. 
 
 Thii 
 
I S L A. 
 
 This ifland, when compared with many of the Hebrides, is 
 low ; none of the hills being above 1 700 feet above the level of 
 the fea. The low grounds are pretty flat, often well flickered ; 
 and, through the exertions of the prefent proprietor, Walter 
 Campbell, Efq, of Shawfield, improvements are carried on with 
 fpirit : the mofs lands are daily rendered arable : thus beautify- 
 ing the ifland, and rendering it the moil productive of the He- 
 brides, its yearly rent being now about 10,000 1. * 
 
 MINERALOGY. To render the few obfervations I have to 
 make on the mineralogy of this ifland diftincl and fatisfactory, 
 I will firft defcribe that fpecies of rock which forms the inte- 
 rior, with its accompanying veins, and then trace the other 
 ilrata around the coafls of the ifland. 
 
 Mining Field. The interior, or middle part of the ifland, 
 from its containing a great number of metallic veins, and be- 
 ing the feat of all the workings, may be called the Mining Field. 
 
 It 
 
 * On the forfeiture of the Macdonalds, Ifla, Jura and the lands of Muck- 
 rain were given to Campbell of Calder, upon condition that he would pay 500 1. 
 of yearly feu- duty out of Ifla. Campbell, about fifty years ago, fold thefe lands 
 to the Shawfield family for 12,000 1. which is now their yearly rent : a moft flrik- 
 ing examp'e of what may be done by fpirited improvements. 
 
I S L A. 
 
 '5* 
 
 It is entirely compofed of blue-coloured limeftone, which is 
 fuppofed to occupy about thirty-iix fquare miles ; extending in 
 diftance (fo far as I could obferve) to the fea-fhore $ neither does 
 it rife to any conliderable height, for other rocks generally take 
 its place when it rifes to a few feet above the level of the fea. 
 The limeftone ftrata dip towards the S. \V. Numerous fymp- 
 toms of galena occur in this limeftone, and feveral veins have 
 been worked with confiderable advantage. The principal feat 
 of thefe workings feems to have been in the neighbourhood of 
 Garthsnefs, which is fituated about the middle of the limeftone 
 diftricl. At this place there are die remains of a lead vein, 
 which runs S. E. and N. W. and dips towards the S. Betides 
 the galena, there alfo occurred, in the working, rich copper 
 pyrites ; and it is faid that, at one time, fpecimens of fulphu- 
 rated manganefe had been difcovered. At Glafgow-beg there 
 is another vein of galena, running E. S. E. and W..N. W. ; but 
 it is traverfed by a baiakic vein, which runs nearly S. S. W. and 
 N. N. E. At a little diftance fouthward from this, we obferve 
 an opeacaft vein, which runs E, and W. and dips to the S. : 
 it is alfo croffed by a bafaltic vein, as that at Glafgow-beg : the 
 
 ba&ltic vein is about nine feet tfide, and has thrown the lead 
 
 
 
 vein about three feet from its original direction. There are 
 many other mineral appearances beiides thefe now mentioned ; 
 but.it would extend thefe notes to6 far to fpecify more of them. 
 
 Many 
 
I ' 3 !> A. 
 
 Many other bafaltic veins are alfo to be feen : fome traverfe the 
 metallic veins ; others crofs each other : in fliort, a plan of 
 this mining field would reprefent a limeilone diflrict divided 
 into a number of angular and fquare fragments. 
 
 The bafaltic veins are of various fizes, from one to twelve 
 feet in width. Many of them run parallel to each other ; fome 
 run in a crofs direction, marking, according to the manner in 
 xvhich they interfect, their relative antiquity f ; and not unof- 
 teii thefe veins fland up like artificial walls, owing to the 
 limeftone being more eafily acted upon by the weather, and 
 being confequently firft carried away. 
 
 Befides the galena, confiderable quantities of copper pyrites 
 have been found, but the quantity too fmall to be of any xonfe- 
 queiice. Alfo, upon the fouth fide of the limeftone diftrict, 
 near to LofTit hill, iron ore has been quarried ; but its fituation 
 is not yet well afcertained ; and I am afraid, from the accounts 
 I have heard, that it will be trifling. The workings in thefe 
 veins have never afforded fluor ipar ; they produce only ba- 
 rytes and calcareous fpar. Fluor fpar is a rare production in 
 
 Scotland; 
 
 ;~ Werner Neue Theorie von der Entstehung der Gangc. 
 
I S L A, 
 
 '53 
 
 Scotland : I have only obferved it twice ; once in Shetland, as 
 will be mentioned afterwards ; and in a vein among the gra- 
 nite mountains of Aberdeenfhire. 
 
 Before concluding this fhort defcription of the mining field, 
 I mall mention two remarkable facts, which feem well authen- 
 ticated. 
 
 i. Silver. It is ^confidently affirmed that a lump of ca- 
 pillary filver, weighing fixteen ounces, was found with the 
 galena, in the vein at Garthsnefs. This is an iiiterefling 
 fact ; and, ihould the veins be again opened, will prove a frefli 
 incentive to carry on the working with fpirit, as it is not impro- 
 bable that veins of filver may be found. We know that fcarcely 
 three years have elapfed fince native -raver was difcovered in 
 Great Britain, and it is of confequence to obferve, that it occur- 
 red in a fituation fomewhat analogous to that in Ifla, the filver 
 forming a firing, branching from the fide of a vein of galena ^, 
 
 2. >uickfilver. A quantity of this valuable metal was difcovered 
 'in a peat mofs fome years ago ; and Dr Rotheram informs me that 
 it is now in the pofTefuon of Mr Campbell. Some flight fearch has 
 
 U been 
 
 f It was at Hurland, in Cornwall, where this filver was difcovered. 
 
154 i s L A. 
 
 been made to difcover its fituation, but without fuccefs. This muft 
 not, however, be confidered as a proof that no veins exift ; for, to 
 determine this, it will require a more regular mode of invefti- 
 gation than has yet been purfued. Farther, the following fadls 
 {how that limeftone rocks are not unfavourable to the produc- 
 tion of quickfilver : i. It is found in globules, in white lime- 
 ftone, at Marfala, in Sicily ; (Mineralogie Sic'dienne, par Borch, 
 Turin 1780.) 2. Behind Guancavelica, in South America, the 
 ardefia pafles into limeftone, which is rich Jin filver and mercu- 
 ry; (Helm Tagebuch reifen durch Peru^ p. 431.) In the mine- 
 ralogical colleclion at Paris there are fpecimens of limeftone, 
 brought from the neighbourhood of Grenoble, which contain 
 quickfilver *. 
 
 Obfervations. The mineral treafures of this iiland, from 
 their being iituated fo near the furface, muft have early attrac- 
 ted the notice of the inhabitants ; particularly as the Norwe- 
 gians, the former mailers of the ifland, were early celebrated 
 as miners. We do not, however, find any mention of thefe 
 mines, until the time of Boethius J, who wrote 300 years ago ; 
 
 but 
 
 * Journal des Mines de la Republique Francoife, No. I. p. 77. 
 % Boethius Sector. Reg. Defcript, - 
 
I S L A. 
 
 but even at that period they feem to have been of much conli- 
 deration, for he remarks, " cum frumenti ferax, turn metallo- 
 rum dives." Since that period they have paffed through many 
 hands ; but do not appear, in any of them, to have been con- 
 dueled with all the judgement necefTary for fo difficult and im- 
 portant a bufinefs. It is a matter of much regret that thefe mi- 
 neral appearances, as well as many others, equally interefling, in 
 different parts of Scotland, have not been profecuted with more 
 advantage. Many circumflances have contributed to this want 
 ef fuccefs ; but, we apprehend, the principal one is to be found 
 in the ignorance of the generality of miners, who are too often 
 men of little education, and obftinately wedded to their own 
 foolifh practices. Even in Cornwall, where the mining bufi- 
 nefs mould be beft underftood, we obferve them often working 
 in an expensive manner. In Scotland particularly, wanderers 
 from other countries, not regularly bred in the principles and 
 practice of mining, have often impofed upon landed proprie- 
 tors, by holding out to them flattering profpects of great 
 gain, and have thus thrown a temporary obflacle in the way of 
 improvement. It is to be hoped that the increafing tafte for 
 chemical and mineralogical fludies will enable proprietors to 
 treat fuch pernicious pretenders with that contempt they fo 
 juftly deferve. 
 
 U 2 Having 
 
IJJ I S L A, 
 
 
 
 Having defcribed the mining field, I ihall now proceed to 
 mine the rocks around the mores of the liland ; and to do 
 this with regularity, will begin at Portaskeg, a finall harbour 
 iituated upon the found of Ifla. Here the cliffs are low, and 
 compofed of compacl micaceous miftus ; which paffes either 
 to Ardefia, or Gneifs ; and in all thefe gradations, are to 
 be obferved, rounded or irregular fhaped pieces of granite. 
 This granite, which is compofed of red-coloured felfpar, and 
 white quartz, and fometimes iron pyrites, cannot be faid to be 
 connected by a pafte in the manner of a breccia, as the gra- 
 nitic mafTes and fhiftus pafs into each other, mowing that they 
 have been formed at the fame time. Ferber *, who has ob- 
 ferved limilar appearances in the mountains of Ruma, agrees 
 with Pallas j~, in fuppofing that gneifs, micaceous fhiilus, and 
 ardefia> are formed from the detritus of granite mountains ; 
 and upon this theory, he explains the appearances we are now 
 confidering. He conjectures, that the groifer particles of gra- 
 nite, having undergone a little alteration, are agglutinated in 
 the form of granite, and inclofed by an aggregation of the 
 fmaller parts, which . become argillificd, forming the ardefia, 
 This explanation is untenable, and unneceflary, when we con- 
 
 fider 
 
 * New Tranfa&ions of the Imperial Academy of Peterlburg, vol. n. 
 
 / 
 
 f Obferyations fur les Montagnes, 410. Peterfburgh, 
 
I S L A, 
 
 fkler that after the greater part of the granite was precipitated, 
 flill a fmall quantity might remain, which would be depofi- 
 ted along with the ardefia, and form thin ftrata inclofed in 
 it J, or irregular fhaped difperfed pieces, as in the cafe at Port- 
 afkeg. 
 
 From Portafkeg the coafl becomes gradually higher as we 
 approach Macarthur's-head, and is formed for a confiderable 
 way of rocks iimilar to thofe I have juft mentioned, which 
 the fea has in fome places * hollowed out into considerable 
 caves. As we approach nearer to this great head-land, the 
 cliffs become much higher, and the micaceous fhiflus, &c. dif- 
 appears ; a granulated quartz taking its place *. Immediately 
 upon the more, I obferved a large bafaltic vein traverfing the 
 granulated quartz, rifing up through it like an immenfe wall, 
 
 and 
 
 j Karften 3 Helvet. Mag. and Monnet 25 J. Phyfique, 85. 
 
 * Mr Mills, in his account of fome ftrata in Ireland and Scotland, detailed in 
 the Philosophical tranfa&ions of the Royal Society of London, for 1790, has given 
 a defcription of Ifla. As it differs confiderably from the observations I am now 
 
 to detail, it will be neceflary as I proceed, to contraft our obfervations ; fo that 
 
 i 
 
 future travellers, may be enabled to judge, who is in the right. Speaking of 
 this part of the iflaud, he fays, '* that it is compofed of chert, which extends to 
 Macarthur's-head, 
 
IjS I S L A. 
 
 and extending along the more to a confiderable diftance ; in 
 fome places forming a powerful barrier between the fea and 
 a few cottages, which are built at the bottom of the cliffs. 
 Having reached the head-land, I obferved the cliffs rifing to a 
 great height, and compofed of ftrata of arenaceous quartz, ele- 
 vated at an angle of 45 ; and the rocks being tinged of a red 
 colour, give a very wild character to the fcene. This arena- 
 ceous quartz extends to a confiderable diftance ; but is at length 
 interrupted by a rock, which has much the appearance of a 
 breccia, being compofed of varidufly fhaped pieces, (and fome 
 of great fize) of the granulated quartz, connected by finaller 
 particles of the fame quartz ; which has intermixed mica, and 
 talc *. Frequently the whole has a red colour, which is owing 
 cither to the decompofition of the mica, or fulphuret of iron, 
 which is fornetimes difperfed through it. As we wandered a- 
 long the fhore, I obferved this breccia interrupted by a vertical 
 flratum of micaceous fhiftus : upon one fide of the flratum, 
 is the breccia ; on the other, is the diftindl granulated quartz. 
 I would recommend this appearance to the particular atten- 
 tion 
 
 * Dr Townfbn in his travels among the Carpathian Alps, obferved great ftra- 
 ta of granulated quartz, (what he caLs primitive fandflonfci ^ing upon granite, 
 and he obferved it in all the ftates From fine granulated quartz to that of breccia, 
 as in the cafe with the rock of Ifla, Travels through Hungary, 4to. 
 
I S L A. 159 
 
 tion of future travellers, for I muft confefs, I was fo fatigued 
 when I reached this fpot, that I could not give it that attention 
 it undoubtedly deferves. The granulated quartz now forms 
 cliffs along the fhore, until we come to a fmall bay, where 
 flrata of micaceous fhiftus appear ; and here the hills rife to a 
 confiderable height, being compofed of micaceous fhiftus upon 
 the lower part, and towards the fummit, probably of gra- 
 nulated quartz. We now crofTed over fome higher grounds 
 until we reached Ben-vinkie, which is faid to be the higheft 
 hill in the ifland, although it is not more than 1 700 feet a- 
 bove the level of the fea. The lower region of this hill is 
 compofed of micaceous fhiftus ; but as we go upwards, gra- 
 nulated quartz makes its appearance ^ and upon the fouth- 
 weft fide, which is very deep, a great vein of bafalt reaches 
 very nearly to the fummit. The country becomes lower af- 
 ter pafTmg this hill, and is pleafantly diverfified with fmall ir- 
 regular hills, that are intermixed with natural wood. The 
 cliffs upon the fhore are not very high, but are much broken 
 by the a&ion of the fea, which has formed many detached 
 rocks ; and thefe, having a grey colour, prefent a flriking pic- 
 ture of fterility. Along with the micaceous fhiflus, we have 
 now ftrata of ardefia, chlorite-flate, hornblende rock * ; and 
 
 thefe 
 
 * Thefe Mr Mill includes under the name of Hornftont . 
 
i6o i s i, A. 
 
 o 
 
 thefe continue to Loch-Kuneftle, a fmall harbour on the coaft. 
 At this harbour, we obferved a low hill called Knock Kuneftlc, 
 which is compofed of ardefia, chlorite-flate, &c. in its lower 
 part ; but upon the fummit, decompofing greenftone makes 
 its appearance. ! could not determine whether it forms a 
 flratum or a vein ; but obferved, that when in a ftate of de- 
 compofition, it affected the "compafs at the diflance of four 
 feet. From this to Lugwillan, the coaft and country conti- 
 nue rugged, and compofed of the fame rocks as thofe which 
 extend from Macarthur's-head to Loch-Kuneflle. This little 
 village, unluckily for the traveller, is extremely wretched ; pre- 
 fenting a fad picture, if not of poverty, yet of dirtinefs and 
 iloth. It would certainly be much for the advantage of the 
 proprietors, as well as conducive to the comfort of the pea- 
 fantry, if commodious houfes were built, and ftridl regulations 
 with regard to cleanlinefs enjoined. I mention with pleafure, 
 that Mr Campbell, has already in part begun this meritorious 
 plan, and it is not to be doubted that he will foon feel the ad- 
 vantages of it. 
 
 After leaving Lugwillan, we met with a .fmall harbour 
 named Leodamis, or Lowdinas bay, which affords fhelter to 
 fmall veffels ; but like other harbours upon this coaft, it is 
 dangerous from the number of funk rocks, which extend to a 
 confiderable diftance. The rocks in this neighbourhood are com- 
 pofed 
 
I S L A, l6l 
 
 pofed of micaceous fhiflus, which by its decompofition forms a 
 fine white fand, that covers the more ; and at the upper extre- 
 mity of the harbour, I obferved feveral pieces of melanteria, 
 or black chalk, which feemed to have been detached from 
 ftrata that probably alternate with the micaceous fhiflus. We 
 
 r 
 
 now walked for ten miles, through a level country, to Loch- 
 laggan, a finuofity upon the fide of Loch-in-daal. The rocks 
 in this tract, are compofed of micaceous fhiflus, and the ge- 
 neral appearance of the country, to the extremity of the ifland, 
 where it is terminated by the lofty Mull of Kinhouth, announce 
 a fimilarity of competition. From Loch-in-daal to the village of 
 Bowmore, we pafTed thro' a level country, formed principally 
 of micaceous fhiftus *, which appears, in fome places, to alter- 
 nate with greenflone. This lafl mentioned foflil, as alfo wac- 
 ken, have been obferved, in other countries, in a fimilar fitua- 
 tion ; but bafalt, as Dr Mitchell informs me, is peculiar to the 
 fiotzgeburge, or flratified mountains. We are, therefore, to 
 confider the obfervations of the celebrated Charpentier f and 
 
 X Faujas 
 
 * Mr Mills remarks, that the whole extent to Kenhoath-head, and fooa 
 to Bowmore, is hornftone. 
 
 
 I 
 
 J 4 Helvet, Mag. 445. 546. Jbid. 3. 236. Charpentier, 8x, 187. 
 
 I 
 
162 I S L A. 
 
 I>aujas St. Fond f, who aflert that bafalt flrata occur in pri- 
 mitive mountains, as indicating only greenftone or wacken. 
 The village of Bowmore, which is the principal one in the 
 ifland, is pleasantly fituated upon the banks of the loch., 
 and is the centre of all the bufmefs in the country. From 
 this to Kiliru the roads lead through a flat country, part 
 of which feems to have been gained from the fea. Near Kiliru 
 rs the feat of Mr. Campbell, which is pleafantly fituated at the 
 laead of the loch, but is much expofed, from the want of plant- 
 ing. From Kiliru to the point of Runs, the ifland is in gene- 
 ral low, excepting about the Runs, where it rifes into hills, of 
 which Bentarvil is the higheft. Being difappointed in examin- 
 ing that part of the ifland, we crofled from Kiliru to Kilchomam 
 The country, in this direction, is low, interfperfed with fmali 
 lochs, and in fome places well cultivated ; and micaceous 
 fhiflus, traverfed with quartz veins, is the only rock that oc- 
 curs. Near to Kilchoman, I obferved an old, ruinous, gloomy 
 building, which was once the feat of the turbulent Macdonald, 
 prince of the Ifles, but is now peacefully inhabited by the mi- 
 nifler of the parifli. From Kilchoman to the fea-coaft, the 
 country is low ; and the rocks, which extend along the fhore, 
 continue to form low, broken cliffs of micaceous fhiflus, alter- 
 nating 
 
 f Faujas fur le Trap, p, 86. 
 
I S L A. 163 
 
 ternating with fand banks, until we come to Saneg-more. Here 
 the cliffs rife to a confiderable height : and, being much expofed 
 to the ocean, are broken into many fantaftic forms, pre- 
 fenting a grand and romantic piece of fcenery. Knowing, 
 from Mr. Pennant *, that there was a fine cave in thefe cliffs, 
 we wifhed to examine it. Accordingly, having procured guides, 
 through the goodnefs of Mr. Campbell of Sanicks, we de- 
 Icended a fteep precipice to its entrance, when we found our- 
 felves furrounded by lofty, rugged precipices, which towered 
 far above us. The grandeur of the fcene was much heightened 
 by the turbulence of the fea, which came rolling in flowly, 
 but with .awful rnajefly, darning among the rocks, with a noife 
 that refounded on all fides like the difcharge of artillery. Hav- 
 ing entered the cave, we found it pretty extenfive, but damp 
 and black, owing to the water falling from above. At a little 
 <liflance, the guides directed us into a narrow opening on one 
 fide, into which we fcrambled with forne difficulty, but found 
 -only a dark, dreary cavity, of little extent. As we walked on- 
 wards, the cave became larger; but we were foon flopped by a 
 pool of water, which appeared to be pretty deep. The guides 
 .crofTed through it, and walked to the further extremity of the 
 cave ; and the effecT: produced by the retiring of the lights, 
 
 X 2 
 
 * Voyage to the Hebrides, 
 
164 * S L A. 
 
 h 
 
 was not the leaft interefting part of this fcene. Formerly, when 
 the cave was dry, the gentlemen of the country ufed to illumi- 
 nate this wild grotto, and collecT: all the beauty of the iile to 
 dance to the bagpipe. 
 
 We now left the cave ; and, in our afcent,. obferved feveral ba- 
 faltic veins traverfing the micaceous fhiftus. From this to the 
 mouth of Loch-Grynard, is an alternation of fandy beaches and 
 low cliffs of micaceous {hiflus and ardefia, in fome places tra- 
 verfed with bafaltic veins, of various fizes, from a few feet to 
 nearly forty feet wide. Thefe appearances are fo numerous, 
 that I could not pombly afford time to examine them all mi- 
 nutely ; fo that it will not be furprifing that after travellers fliould 
 find, in fome places, flrata inftead of veins. Loch-Grynard is 
 of confiderable extent ; is ufually bounded by fandy banks, 
 but fometimes low rocks of micaceous fhiflus appear 5 and 
 at its head are the links or downs we have already men- 
 tioned, which extend nearly to Loch-in-daal. From this loch 
 to the great caves which are fituated upon the north-wefl 
 part of the ifland, the more is, as ufual, an alternation of 
 low, rugged cliffs of micaceous fhiftus and fandy beaches ; but, 
 as we come nearer to the caves, the cliffs are much higher, and, 
 in place of micaceous fhiftus, we have rugged precipices 
 of granular quartz. We defcended a path made in thefe 
 
 cliffs, 
 
I S L A. 165 
 
 cliffs, which brought us among rocks terribly broken by the 
 lea ; and after walking a few hundred feet, the caves prefented 
 themfelves with much dignity. The height of the rocks in 
 which they are fituated ; the wild and rugged grandeur of the 
 neighbouring hills ; the folitude of the place ; all add frefh in- 
 tereft to this ftriking fcene. The great cave, or what is called, 
 in the Erfe language, Ea-maur, is about thirty-three yards wide 
 at its entrance, and from fix to eight yards high : as we go in- 
 wards, the roof becomes higher, but it foon again contracts in 
 all its dimenfions ; and about 150 yards from its entrance, it is 
 fo narrow and low, as to prevent any one from getting farther. 
 It is fituated in granular quartz, as is the cafe with the other 
 fmaller caves. The celebrated SaufTure has lately published a 
 feries of experiments upon the temperature of caves, in which 
 he obtained fome curious refults. I repeated them carefully 
 in the great cave, but did not find a difference of more than 
 8 of Fahrenheit between the temperature of the cave and 
 that of the made. 
 
 At a little diftance from the caves, I obferved the granular 
 quartz covering a fpecies of miftofe talc, and, alfo, a fpecies of 
 marl, in the neighbourhood of the granular quartz and micaceous 
 ihiftus : but I had not an opportunity of examining their relative 
 
 pofhioru 
 
 * Mr Mills remarks that the caves are in rocks of chert. 
 
l66 1 U R A. 
 
 pofition. From this we crofled a very fatiguing moor to Portas- 
 keg : the rocks, all the way, are of granular quartz, (extending 
 even to the fummit of the higheft hills,) excepting a few pla- 
 ces iTpon the fea more, where micaceous fhiflus appears. 
 
 JURA. 
 
 THIS ifland is about 32 miles long, and 6 broad; but at 
 Tarbet it is nearly divided, being only a mile and a half broad. 
 It is bounded on the E. by Knapdale and Cantire ; on the S. 
 by the ifland of Ifla ; upon the W. by Colonfay, Oranfay, Mull, 
 &c. ; and towards the N. the Slate iflands. It is in general 
 very mountainous, particularly upon the S. W. extremity, 
 where are fituated the high hills called the Paps of Jura. None 
 of the Hebrides prefent fuch a mafs of rugged barrennefs. The 
 hills are often grey and bare ; and the fcanty portions of the 
 lower ground which are cultivated, feem ill managed. The 
 more upon the eafl fide is in general low ; but upon the weft it 
 xifes frequently to a great height, and is broken into many ftri- 
 g forms; particularly we obferve extenfive caves, which afford 
 
 fhelter 
 
i6 7 
 
 flicker to the deer and goats that browze among the neighbour- 
 
 ing rocks. 
 
 The mineralogy of this iiland, as far as I ex- 
 amined it, is but little interefting, as it does not differ mate- 
 rially from that of the fhores of Ifla. I mall not omit, how- 
 ever, to give a fhort account of it, as its mineralogy has not 
 engaged the attention of any writer. 
 
 Immediately below Ardfm, the feat of the hofpitable Archi- 
 bald Campbell, Efq. I obferved flrata of granular quartz, incli- 
 ned at an angle of 45 j yet they are not regularly fo, for I 
 obferved them inclined at different angles in other parts of the 
 ifland. This rock forms the coaft of the ifland all along the 
 found of Ifla, and, as far as I could obferve, it appears to exr- 
 tend along the whole weft coaft. The cliffs are, in fome plai- 
 ces, of confiderable height ; and the great mafles which are 
 feparated from them have,, in general^ a tendency to the pyra^- 
 midal fhape. This is another fact, fimilar to what I obferved 
 in Arran, mowing that particular rocks break in fuch a manner 
 as to be characleriftic of their peculiar nature. Thefe quartzy 
 mafles, by further decompofition, fall into fmall cryftalline 
 grains, which cover the more, in fome places, to a confiderable 
 
 extent ; 
 
l63 JURA. 
 
 extent ; and form a fand, which is afTuredly among the pure ft 
 that nature affords. It has been ufed with much fuccefs in the 
 making of fine glafs ; and I have little hefitation in faying, 
 that it is worthy of being more generally known as an article 
 for glafs-making : indeed it might alfo be advantageoufly ufed 
 for the making of fmalt, and different kinds of porcelain, in 
 the place of powdered quartz, or flint. 
 
 Many bafaltic veins are to be feen traverfing thefe quartzy 
 flrata, which extend along the found of Ifla and the weft coaft 
 of the ifland : and it is curious to obferve the manner in which 
 thefe two rocks decompofe ; for upon this circumftance de- 
 pends the varied appearance of the rocky fcenery on the 
 weft coaft of Jura. Sometimes the bafalt decays firft, leav- 
 ing only the empty fpace which the vein had formerly filled ; 
 and this afterwards is much enlarged by the decaying of the 
 quartz : thus forming caves fuch as are reprefented in the 
 plate. In other inftances, the granular quartz decays firft; 
 and either falls away from the fide of the bafaltic vein, or 
 is warned away by the fea : thus leaving the bafaltic rocks 
 extending acrofs the beach like immenfe walls. Thefe great 
 maffes of bafalt are often broken into various fhapes ; but 
 
 the 
 
JURA, 
 
 the moft ftriking .appearances are formed by the central part 
 of the vein decaying firft, which leave magnificent arches : 
 but the engravings of this coafl will convey a more lively idea 
 of the character of thefe rocks, and the general appearance of 
 the fcenery, than any defcription. 
 
 There are many caves upon this coail, and fome of them of 
 vafl lize ; but my time did not allow me to vifit the mofl re- 
 markable. In wandering among the rocks, I obferved feveral 
 banks of coral fand ; which I was happy at obferving, as it will 
 be of great ufe to this iiland, heretofore deflitute of all kinds 
 of calcareous matter, and abounding with much improvable 
 peat mofs. 
 
 PAPS of JURA. Thefe mountains, which are the mofl ele- 
 vated in the ifland, are diftinguifhed by different names. The 
 three moft remarkable are, Beinn-a-chaolois, or, the Mountain 
 of the Sound ; Beinn-iheunta, or, the Hallowed Mountain ; 
 and Beinn-an-oir, or, the Mountain of Gold. The laft moun- 
 tain is the higlieft ; being about 2600 feet above the level of 
 the fea ; and is, like the others, fomewhat of a conical fhape. 
 
 We clambered to the fummit of one of thefe hills, but 
 found the afcent very fteep, and fatiguing, from the number of 
 fmall loofe ftones that cover its fides : but our fatigues were 
 
 Y foon 
 
j;o JURA. 
 
 ibon forgot in the immenfity and variety of the profpecl now" 
 before us. Immediately below was the rugged fcene of the 
 grey, florm-beaten rocks of Jura, interfperfed with numerous 
 lakes ; conveying, as Mr Gilpin remarks, the idea of complete 
 flerility. To the S. the ifland of Ifla feemed fpread under our 
 feet ; and, farther diflant, appeared the coaft of Ireland. To 
 the W. we obferved the fmall ifles of Gigha and Cara, thq 
 ifthmus of Canty re, and the lofty red-coloured granite moun- 
 tains of Arran, forming a (hiking contrafl to the fombre hue 
 of the mountains of Caiityre ; and, flill at a great diflance, our 
 view was bounded by the diflant county of Ayrfhire. On the 
 N. E. we obferved the wild alpine ridges of Argylefhire, ex- 
 tending all the way to Ben-Lomond. To the W. the Hebri- 
 des appear, fcattered through the ocean : the ifles of Colonfay 
 and Oranfay are in our immediate neighbourhood j farther dif- 
 taiit, is the mountainous ifland of Mull, the celebrated I-colm- 
 kill, with the adjacent ifles ; and the long-extended ifles of Coll 
 and Tirie appear like a haze in the horizon. 
 
 Thefe mountains are principally compofed of ftrata of a gra- 
 nular quartz, elevated at an angle of 45, and dipping to the 
 fouth-weft. From the fummit of the hill, the ftrata appear to 
 run in different directions ; fome curved, and others nearly 
 horizontal : thefe appearances, however, are probably more 
 
 owing 
 
JURA, X yi 
 
 owing to the fituation from which I viewed them, and the 
 ends of the ftrata being worn down by the rain, &c. than to 
 any alteration in their dip or direction. The fragments of 
 rock which cover the fides and tops of thefe mountains, are 
 broken into fmall angular fragments ; which, obferved at a dif- 
 tance, and even with a telefcope, would Ihow us, that they are 
 formed of a rock very different from granite ; as the latter 
 almoft always decompofes in large rhomboidal malTes. 
 
 I frequently obferved mafles of this granular rock; which, 
 from its containing felfpar and mica, is to be confidered as a 
 true granite. This facT:, will be reckoned, by certain geolo* 
 gifts, as decifive againft the opinion of Mr Werner ; who af- 
 firms, that granite is the oldeil rock, and confequently, that 
 tipon which the others reft. It cannot be denied, that there 
 are feveral facts, detailed by the moft intelligent geologifts, 
 which fhow, that granite is fometimes of a cotemperaneous 
 formation with ardefia *, micaceous ihiftus f, and gneifs ; 
 yet they are fo rare, that I can only conclude from them, as I 
 liave before mentioned, that after the greater part of the gra- 
 
 Y 2 nite 
 
 * Reufs Mineralogifche Geographic von Bohmen, B. 2. 
 f Journal de Phyfique. New feries, vol. I. 
 t Emmerling's Mineralogie, B. 3. 
 
172 JURA, 
 
 nite had been precipitated, ftill a fmall portion remained in fo- 
 lution ; and was afterwards depofited along with the gneifs, or 
 other primary rocks. The opinion of Mr Werner, on the 
 other hand, is fupported by fo vaft a mafs of evidence, as bears 
 down all oppofition. Thus, according to Sauflure, the granite 
 of the Alps, excepting in one or two inftances, is always co- 
 vered with other flrata ; itfelf forming the interior, and often 
 the highefl parts of the mountains, The fame obfervation has 
 been made by Baron Born, and Efmark in the mountains, of 
 Hungary and Wallachia ; by PalalFo, La Peyroufe, and Car- 
 bonieres in the Pyrenees ; by Reufs in the mountains of Bo- 
 hemia ; Lazius in thofe of the Hartz ; by Patrin, Herman, Pal- 
 las in the vaft extended empire of Ruflia j by the French 
 mineralogifls in all the granite mountains of France ; alfo in 
 the granite mountains of the Weft Indies, and in the few 
 which have been examined in England f and Scotland. 
 
 Having mentioned the different kinds of rock which form 
 the coaft and hills, from Ardfin, along the fouth and weft 
 parts of the ifland. We will now proceed along the eaftern 
 
 more 
 
 f In the great mine in Cornwall, called the Cooks Kitchen, I have been told, 
 that the granite has been found above the ardefia (or killas). I have not as yet 
 had it accurately confirmed. 
 
JURA. 173 
 
 Ihore, from the fame place. Upon the more, at a little dif- 
 tance from Ardfin, ftrata of micaceous fhiftus, alternating 
 with rocks intermediate between talcaceous fhiflus and ar- 
 deiia, appear, and continue forming low cliffs along the Ihore 
 to the harbour of the fmall ifles *. Thefe rocks are fome- 
 times very compact, and have a tendency to break into irre- 
 gular columns ; fo that in fome points of view, they are not 
 unlike columnar bafalt : we alfo obferved bafaltic veins tra- 
 verftng them in many places. From this the country gradu- 
 ally rifes as we approach the high hills, the paps of Jura ; and 
 in fome places, as upon the road leading from Ardfin to Small 
 Ifles, chlorite-flate is to be obferved alternating with the other 
 rocks. This chlorite-flate, fometimes paffes to hornblende 
 rock, by a mixture of green hornblende j and it fometimes 
 contains calcareous fpar, and cryftals of yellowim-green adty- 
 nolite difperfed ; but this latter is a rare appearance. Not 
 unoften I obferved the chlorite penetrating the quartz, form- 
 ing a dark green coloured flone ; and here I was fo fortu- 
 nate as to difcover that rare foflil, the cryflalized chlorite, of 
 which a particular defcription is given in the following chap- 
 ter. If we ftill continue our courfe towards the high hills, we 
 
 at 
 
 * About a mile diftant from Ardfin, we landed upon a fmall low ifland, which 
 is compofed in general of a coarfe taleaceous fhiftus j and between the ftrata we 
 obferved layers of beautiful hornflone, 
 
i;4 JURA, 
 
 at length find the granular quartz^ rifing from under the 
 micaceous fhiftus, at an angle of 45, and from this, the whole 
 country to the fummit of the mountains is formed of the 
 fame rock. 
 
 "We would naturally conclude, from finding the quartz 
 ftrata lowermofl, that it had been depofited before the micace- 
 ous fhiftus ; this is only true in part, as we fometimes obferve 
 the micaceous fhiftus patting to granular quartz, at a great di 
 tance from the junction f . 
 
 As far as my experience goes, mountains of granular quartz 
 are to be confidered as rare occurrences in Scotland : in Caith- 
 nefs, I obferved quartz mountains, as will afterwards be men- 
 tioned : and Mr Williams tells us of quartz mountains in Rofs- 
 fhire * : but thefe are the only inftances I am acquainted 
 with* It is even an unfrequent rock in other countries ; in 
 the Carpathian Alps, Dr. Townfon informs us, he obferved 
 what he calls primitive fandftone lying upon granite j and Mr 
 Deriabin, to whom I mowed the Jura rock, afTures me that it is 
 
 fimilar 
 
 -fyln Brainfdorf, in Saxony,granular quartz lias been obferved pafling into mica- 
 ceous fhiftus. 2 Crell. Beytr, 64. 
 
 * WSliams's Mineral Kingdom, vol. a.-p. 52.' 
 
J U R A, , i 
 
 fimilar to that which forms fo great a portion of tlicfe moun- 
 tains. 
 
 As the difcovery of limeftone would be of much fervice in 
 the agricultural operations of this ifland, we were anxious to af- 
 certain if any fuch flrata exifted between the Small Ifles and the 
 Sound of Ifla. To determine this, we examined not only the 
 fhores, but the ravines upon the fides of the hills, yet without 
 fuccefs. This failure in our refearches does by 110 means imply 
 that limeftone do^s not exift in this diftrict, particularly when 
 we recollect that thefe rocks are not unfavourable to it. We 
 have many inftances of limeftone being found in micaceous 
 fhiftus, in different parts of Scotland, as at Dalmally, near Blair 
 in Athol, &c. J It may even occur in granular quartz ; as 
 Efcher has obferved limeftone among granular quartz in the 
 valley of Reufs. Townfon upon the granulated quartz (pri- 
 mitive fandftone) of the Carpathian Alps, 
 
 The harbour of the Small Ifles is rendered pretty fafe by 
 
 three 
 
 $ Werner has obferved limeftone alternating with micaceous fhiftus and arde- 
 fia, in Saxony : fo has Charpentier, and that in great ftrata. Werner, Kurze 
 Claffific, 14. Charpent. 55, 56, 57, 174, 201, 400, 
 
Ij6 3 U R A. 
 
 three or four fmall iflands, that defend it from the violence of 
 the fea. It will admit veflels of feveral hundred tons ; yet, as the 
 ifland and the neighbouring country are but thinly inhabited, 
 few vefTels are to be feen enlivening this folitary fcene. The coun- 
 try in the neighbourhood rifes gradually as it approaches the Paps 
 of Jura, which here prefent a magnificent and ftriking mountain- 
 ous fcene. The ftrata, from the more to the vicinity of the Paps 
 of Jura, are compofed of micaceous fhiftus ; excepting at one 
 place, about half a mile north from Mr Macnicol's houfe, 
 where we obferved a ftratum of ardefia tegularis (roof (late) 
 cropping through the heath. This ftratum, which appears to 
 be of conliderable breadth, is bounded by the micaceous fhif- 
 tus ; and, near the junction, the micaceous fhiftus contains cu- 
 bical cryftals of iron pyrites *. 
 
 i 
 From the Small Ifles to Luggan, the ftrata of micaceous 
 
 fhiftus ftill continue, often very compact, and frequently 
 traverfed by bafaltic veins. At Tarbet, which is the nar- 
 roweft part of the ifland, the land immediately upon the fhore 
 ii low ; and the eye is refrefhed by the appearance of a beau- 
 tiful 
 
 * May not the .prefence of cubical pyrites, in micaceous fhiflus, be indica- 
 tive of the vicinity of ardefia tegularis ? 
 
JURA, 177 
 
 tiful green flat, at the bottom of the grey hills which bound 
 the more. From, this to Kenawochrach, the northern extremi- 
 ty of the iflancl, micaceous miftus appears to be the general 
 rock, but it is fometimes alternated with ardefia tegularis. At 
 one place the ardelia has been quarried ; and, from what we 
 could learn, there can be little doubt that, with well-directed 
 experience, the working may become of confequence. 
 
ISLA AND JURA. 
 
 CHAP. XL 
 
 Defcription of the FOSSILS mentioned in the preceding Chapter. 
 
 GRANULAR QUARTZ. 
 
 Dr Walker's ClafTes Foflilium. PRIMITIVE SAND- 
 STONED Mr Kirwan's Geological EiTays, p. 208. ^uAnrz^ 
 Ibid. p. 179. 
 
 This rock, which we have fo often obferved in the iflands 
 of Ifla and Jura, is defcribed by Dr Walker under the name of 
 Cyamea Jurae ; and, more lately, Mr Kirwan, in his Geologi- 
 cal EfTays, defcribes iimilar rocks under the names of Arenace- 
 ous Quartz and Primitive Sandflone. There are many fpecies 
 of this rock in thefe iflands ; but I will only mention three of 
 the moft remarkable, 
 
 i. COM- 
 
ISLA AND JURA, 179 
 
 1. COMPACT. 
 
 Colour. White, or grey. 
 Lujlre. Little glancing. 
 
 Tranfparency. Tranfmits light at the edges ; but when 
 the fpecimen is thin, the light pafTes through the 
 whole. 
 
 Hardncfs. Strikes fire with fteel. 
 FraEture. Even, coarfe fplintery, and. frequently mif- 
 
 tofe in the grofs. 
 
 Intermixed with quartz, (which is fo compact as to render 
 the granular character difficultly obfervable,) I always ob- 
 ferved a number of white fpecks, which are either felipar or 
 mica, or both, ufually in a flate of decompofition. . Sometimes 
 veins of compact quartz are to be obferved traverfing this. 
 Ipecies. 
 
 2. MICACEOUS. This fpecies is compofed of quartz, and a 
 fmall portion of mica. The mica is always in fmall fcales, and 
 is either yellow, brown, or white. Often the mica is fo abun- 
 dant, that we have a true micaceous fhiflus. , 
 
 3. GRANITIC.. In this fpecies, the granular appearance is 
 more evident : and, intermixed with the quartz, are numerous 
 cryftals of red and white felfpar, of various fizes, from a pin* 
 
 Z 2 headi 
 
l8o ISLA AND JURA. 
 
 head to half an inch ; and a few fcales of mica alfo, now and 
 -then, occur. Not unoften cubical cryftals of iron pyrites are 
 intermixed with the other ingredients, and, by their decompo- 
 fition, caufe the ilone to acquire a brown colour, or to difinte- 
 grate altogether. This fpecies, therefore, is to be reckoned an 
 approximation to the granite, from which it differs but in the 
 proportion of felfpar and quartz. 
 
 MICACEOUS SHISTUS. 
 
 This rock occurs in Ida and Jura, and is confiderably 
 varied in its appearance. The quartz is of various co- 
 iours, as black, blue, or white ; and is generally granular. 
 The jnica is alfo of different colours, as black, brown, 
 greenifh, or white : the fcales are, in general, fmall ; the largeft 
 are thofe in the rocks in the ftrata that extend to the north end 
 of Jura. The micaceous fhiftus at Lag in Jura, at a diftance, 
 is not unlike bafalt ; but a nearer examination difcovers a com- 
 pound of black and dark-blue coloured quartz, with fmall fcales 
 of black mica very clofely compacted together. It often alfo 
 contains iron pyrites, which, by its decompofition, forms a num- 
 ber of ruft-coloured fpots. Sometimes cryftals of felfpar occur 
 when it pafles to gneifs ; or the quantity of quartzy particles 
 tncreafe when it paffes to the ftate of arenaceous quartz. 
 
 ARDESIA. 
 
JSLA AND JURA* 
 
 ARDESIA, 
 
 Colour. Bluifh or blackifh grey. 
 
 Lujlre. Silky. This iilky glofs, Mr Kirwan remarks, inti- 
 mates magnefia. 
 
 Tranfparency. None. 
 
 Frafture. Streight, flaty ; the laminae are undulated upon the 
 furface. 
 
 Hardnefs. Eafily fcraped with a knife : but this degree -of 
 foftnefs is probably owing to the influence of the weather, 
 as the fpecimen now defcribed was taken from the furface of 
 the flratum. 
 
 Streak. Grey. 
 
 Smell. Emits a flrong earthy fmell when breathed on. 
 
 Cubical cryflals of iron pyrites are difperfed through it ; and 
 thefe, by the efcape of the fulphur, are converted into brown 
 iron ore. It is worthy of remark, that the pyrites which occurs 
 in the primary ftrata is much lefs liable to decompofition than 
 that which we find in the fecondary ; and farther, that altho* 
 we find pyrites very abundant in the primary ftrata, yet the 
 combinations of the fulphuric acid with earths are rarely to be 
 
 obferved, 
 
JSLA AND JURA. 
 
 obferved *. Mr Kirwan, in the fecond volume of his Mine- 
 ralogy, explains to us the difference between thofe pyrites that 
 efflorefce and decompofe quickly, and the others which decom- 
 pofe more flowly. He remarks, that thofe pyrites which efflo- 
 refce fpontaneoufly, contain iron in a metallic ftate ; but the 
 others which decompofe more flowly, and by the feparation of 
 their fulphur, have the iron in the ftate of an oxyd, 
 
 CHLORITE SHISTUS. 
 
 CHLORITE, Kirwan's Mineralogy. ARGILLA CHLQRITES 
 SHISTOSUS, Werner. 
 
 Colour. Dark-green. 
 
 Internal Lujlre. Little glancing. 
 
 T'ranfparcncy. None. 
 
 Frafture. Slaty ; lamellae pretty eafily feparable. 
 
 Hardnefs. Yields eafily to the knife. 
 
 Streak. 
 
 * Gypfum has been difcovered mixed with mica in Mount St. Gothard ; 44 
 J. de Phyfique. Pallas has obferved gypfum affociated with felfpar in Siberia ; 
 5 Nord. Beytrage. Sulphat of Barytes has been obferved in gneifs in the moun- 
 tains of Savoy, as mentioned by Weoner. Thefe are the few inftances that are 
 known* 
 
ISLA AND JURA. 
 
 Streak. Green. 
 
 SmelL Has a ftrong earthy fmell, when breathed on. 
 
 Frequently grains and layers of quartz are to be obferved 
 mixed with the chlorite ; and fometimes the quartz is penetra- 
 ted with it, forming a foml not unlike prafe. Iron py- 
 rites are fometimes intermixed with the chlorite, and, by their 
 decompoiition, colour the rock brown. Cryftals of green horn- 
 blende are alfo to be obferved intermixed with the chlorite ; and 
 according to the quantity of hornblende, the rock palTes more 
 or lefs to the ftate of hornblende rock, 
 
 FOLIATED CHLORITE. 
 
 BLATTRIGER CHLORITE? Werner, Efthner's Mineralogie, Em- 
 
 merling's Mineralogie. 
 
 The colour is that of the common chlorite. 
 
 Ic is found not only mafuve, but alfo difperfed, and cryftal- 
 
 lized. 
 The cryftals are in the form of a double conical pyramid, 
 
 with truncated apices ; and are to be obferved alfo in the 
 
 form of a cylinder, with a cone or conical pyramid upon 
 
 each extremity. 
 
 The 
 
1SLA AND JURA. 
 
 The crvflals are fmall. with little luftre on the outfide. but flrong; 
 
 j 
 
 glancing f internally. 
 
 Ltiflre. Intermediate between the greafy and mother of pearl. 
 
 Fratfure. Foliated ; but moil commonly curved foliated. 
 
 Tranfpare?icy. Semi-diaphanous ; or fuch as to permit light to 
 pafs thro', but fo little that objects cannot be diftinguimed. 
 
 Hardnefs. Not eafily fcratched with the nail, yet yielding eafily 
 to the knife. 
 
 Fragments. Tabular ; feels a little fatty ; and is not remarka- 
 bly heavy. 
 
 It is found inverting white-coloured quartz, but more com- 
 monly well cryflallized in cavities of the quartz. I have only 
 obferved it in the ifland of Jura, among the ftrata of chlorite 
 fhiftus, upon the road from Ardfin to the harbour of the Small- 
 Ifles. According to Emmerling, it is a very rare foflil ; as it 
 has been obferved in one other place only, that is, upon the 
 mountain of St. Gothard, in Switzerland, where it is accom- 
 panied by cryflals of adularia, reddifli-brown fchorl, and rock 
 cryftal. 
 
 HORN. 
 
 f Stark glanzend- 
 
1SLA 'AND JURA. 185 
 
 HORNSTONE. 
 
 ACHATES PJSTROSILEX, Lin. SILEX CORNEUS, Wern. Nico- 
 , Dr Walker. CHERT, Angl. 
 
 Colour. Pale brown ; in fome parts green, when intermixed 
 
 with the magnelian rock in which it lies. 
 Lujlre. None. 
 
 Tranfparency. Tranfmits a little light at the edges. 
 FraEture. Fine fplintery. 
 Hardnefs. Strikes fire plentifully with fleeL. 
 
 Where it is in contact with the magnefiaiV rock, it is much 
 intermixed with it, has a green colour, and at length fairly 
 pafles into the talcaceous fhiftus of which the ifland is formed. 
 Sometimes we find veins of cryftallized calcareous fpar traver- 
 fmg it, 
 
 A a TAL- 
 
1SLA AND JURA. 
 
 TALCACEOUS SHISTUS. 
 
 LAPIS OLLARIS, Waller. TALCUM OLLARIS, Lin. TALC SCHEI- 
 FER^ VERHARTXTER TALC, Germanor. TALCUM PROPRIUM 
 OLLARI, Werner. 
 
 Colour. Dark-greenim black, or yellow. 
 
 Lujlre. Nearly as fhining as filk. 
 
 Tranfparency. Sometimes tranfmits a little light at the edges j 
 
 in other fpecimens, when it paffes to ardelia, it is opaque. 
 Frafture. Shiflofe. 
 Hardnefs. Yields to the knife eafily ; but, as it pafTes to the 
 
 ilate of argillite, becomes harder. 
 Streak. Grey. 
 
 This rock is. to be obferved pafling, upon the one hand, to 
 the chlorite flate, and, on the other, to ardefia. It is found in 
 different parts of the iflands of Ifla and Jura, as has been men- 
 jtioned in the preceding chapter* 
 
 XIME- 
 
ISLA AND JURA. 187 
 
 Colour. Dark blue. 
 
 Lujlre. Very weak, principally from, a few {liming particles 
 
 difperfed through it. 
 'Tranfparency. None. 
 Fratturc. Even, fine fplintery. 
 Hardnefs. Yields with fome difficulty to the knife. 
 Streak, Grey. 
 
 It forms the central part of the ifland of Ifla, and contains 
 no petrifactions ; which renders it probable that it is of 
 primitive formation. It may be objected to this, that all pri- 
 mitive limeflones have a fcaly or granular grain. We cannot 
 doubt that, in general, this obfervation is perfectly correct ; 
 but it feems liable to exceptions : as Mr Kirwan, in his Geolo- 
 gical EfTays, mentions, upon the authority of the Helvetic Ma- 
 gazine, that the mountains of Wetterhorn, Wellhorn and 
 Burghorn are formed of primitive limeftone having a fplin- 
 tery fracture j and I fhall afterwards mention primitive lime- 
 ftone, or marble, with a fplintery fracture, as occurring in the 
 Hebrides-, Mr Kir wan further mentions, that, as fome traces 
 
 A as of 
 
ISLA AND JURA. 
 
 of muriatic acid are to be found in fecondary limeftone, and 
 none in the primary, this may ferve as a good teft for diftin- 
 guifliing them. I have not, however, made any experiment, 
 with this view, upon the Ifla limeftone. 
 
 COMPACT MARL STONE MARL. 
 
 VERHARTETER MERGED Germanor. CALCAREUS MARGA INDU- 
 
 RAT A, Werner. 
 
 Colour. Yellow, or yellowifh white. 
 
 Ltiftre. None. 
 
 Tranfparency. None ; but, when much penetrated with ulice- 
 
 ous matter, tranfmits a little light at the edges. 
 Frafture. Fine fplintery. 
 tfardnefs. Yields with difficulty to the knife ; and, when 
 
 penetrated with filiceous particles, fcarcely yields to the 
 
 knife. 
 Is flowly acled upon by acids, and feels heavy. 
 
 It is ufed for the purpofes of agriculture, but it requires feve-- 
 ral years before it falls, 
 
 MELAN- 
 
 
JSLA AND JURA. 189 
 
 MELANTERIA, Pliny BLACK CHALK. 
 SHISTUS fcrlptura atra^ ater inquinans^ Linn. AJLGILLA NIGRI- 
 c^, Werner. SHISTUS NIGRICA, Waller. MELANTERIA^ Dr 
 Walker. 
 
 Colour. Bluifh black. 
 
 Lujlre. Longitudinal fracture extremely little glancing, and 
 
 the crofs fracture none. 
 Fraffure. Longitudinal fracture, curved flaty ; but the crofs, 
 
 fine earthy. 
 Streak. Little glancing. Colours black, but without the lu- 
 
 tre of plumbago. 
 Hardnefs. Pretty eafily fcratched with a knife. 
 
 This foflil occurs often in the neighbourhood of aluminous 
 fliiftus ; and is always found, difpofed in beds, in the primitive 
 mountains, particularly in ardeiia. As it writes upon paper, 
 and has a bluim-black colour, it has often deceived the unin- 
 formed, who have imagined they have difcovered black lead : 
 the difference of luflre, and other characters, however, fufE- 
 ciently diftinguim them, It has alfo been taken for coal, or 
 reckoned a proof of the vicinity of coal firata. Thus, Dr 
 
 Reuis, 
 
190 ISLA AND JURA. 
 
 Reufs y, in travelling through Bohemia, tells us, that he ob- 
 ferved a {haft funk fcveral fathoms through ardefia, and, upon 
 enquiry, he found it was in fearch of coal. This coal, how- 
 ever, upon examination, he found to be a fpecies of aluminous 
 Hate, v.ery nearly refembling black chalk. This mould ferve 
 as a flrong caution againft making trials, without having nrft 
 examined carefully the rocks which we think indicate the pre- 
 fence of coal ; and farther, whenever any coal-like fubftance 
 (which was the cafe here) is obferved only among primitive 
 rocks, it mould excite a ftill ftronger doubt, when we recollecl: 
 that coal has never yet been detected, nor probably ever will, 
 in any quantity, in primitive mountains- 
 
 Miner alogifche Geographic von Boehmen, Zweiter band, j 202% 
 
C H A P. 
 
 Voyage from JURA to the Slate IJlands of SEIL and E AS DALE ; 
 thence to OBAN and the IJland of MULL. 
 
 JLJ.AVING found it very inconvenient to examine the weft 
 and northern parts of Jura, Mr Macnicol, the minifter of the 
 iiland, (to whofe kindnefs we were much indebted,) procured 
 a boat, and we failed from the harbour of the Small Ifles to 
 the ifland of Sell, a diftance of about 30 miles. As the weather 
 was charming, we kept clofe along the more of Jura, which 
 gave us an opportunity of landing upon different parts of the 
 iiland. Having reached the northern extremity, the wind in- 
 creafed a little ; foon after, we heard the great whirlpool, the 
 Coryvrekan, raging, in the fovind between Jura and the iiland 
 jof Scarba, 
 
 We 
 
Ip2 3 E I L. 
 
 We now pafTed the rugged ifland of Scarba, which is appa- 
 rently compofed of micaceous fhifhis traverfed by bafaltic 
 veins ; next, the ifland of Luing, faid to afford much ardeiia ; 
 foon after, the fmall ifle of Balinahuia, where there is an exten- 
 five quarry of ardefia ; and, at fome diftance, we obferved the 
 ifland of Garveloch, where there is a considerable quarry of 
 fhiftofe marble*, firfl difcovered, many years ago, by Dr Walker. 
 After much oppofition from an extremely violent tide, we at 
 length landed upon the ifland of 
 
 S E I L. 
 
 THIS ifland, about 3 miles long, and 2 miles broad, is feparated 
 from the ifland of Eafdale by a ftrait a few hundred feet broad, 
 and from the mainland by a narrow pafs over which a bridge has 
 been thrown. The ifland is in general flat, yet not without hills, 
 from the highefl of which we have a pleafant view, of the ma- 
 ny 
 
 * This marble rifes in flags of a confiderable fize, Tome 3 feet by 2, and even 
 4 feet by 3 ; takes a good polifli j and is of a white or grey coloury and is fome* 
 times clouded \ and has a fine grain* 
 
S E I L. 193 
 
 ny fmall ifles fcattered over the ocean, with the diftant moun- 
 tains of Mull and Jura. 
 
 The greater part of the iiland is compofed of rocks of primi- 
 tive formation, and thefe are 'micaceous miftus and ardeiia. 
 Bafaltic veins are alfo very frequent, traverfing both kinds of 
 ftrata ; and, where the flratified matter is wafhed away, or has 
 fallen down by decompofition, the perpendicular veins appear 
 often like bafaltic crags, and, at firfl fight, may be taken for 
 ftrata. Confiderable veins of quartz are alfo to be obferved 
 traveriing the primary ftrata upon the fouth and eaft mores of 
 the ifland ; and, near to the fouthern extremity, I obferved a 
 vein of quartz which contained a quantity of iron pyrites, but 
 apparently too fmall to be of any importance. 
 
 Befides thefe primary ftrata, I obferved, upon feveral parts 
 of the ifland, fmall portions of the tranfition (uebergangsge- 
 t>urge) and fiotz rocks (flotzgeburge). Near to Mr Campbell's 
 houfe, I obferved the ardeiia covered by grauwacken, and both 
 apparently traverfed with the fame bafalt vein j which leads 
 us to fuppofe that they were formed at the fame time ; and, in 
 fupport of this, I may mention, that German mineralogifts 
 have obferved thefe rocks to alternate *. Upon the fide of the 
 
 B b ifland 
 
 * Eijimerling, Band. 3. 105, 
 
i 94 E A S D A t Ev 
 
 iiland oppofite to Eafdale, we have an appearance of flotz ilra- 
 ta. Immediately upon the fhore, I obferved red -coloured 
 argillaceous fandflone, flratified with fandflone breccia and 
 bafalt, and' the whole traverfed with bafaltic veins. There are 
 alfb quarries of ardefia tegularis in fome parts of the ifland. 
 But the principal attention of the proprietors is turned to the 
 ifland of Eafdale, where the (late has hitherto been found in 
 great quantity. 
 
 1-AS-D ALE. 
 
 THIS ifland is about half a mile long, and of the fame breadtK^ 
 and is celebrated for its having afforded the befl and greateft 
 quantity of ardefia tegularis, of any part, of equal extent, in 
 Great Britain. A very connderable portion of the ifland is 
 compofed of ardefia tegularis, and this is traverfed by bafalt 
 veins. The ardefia, where in contact with the bafalt^ is ufelefs, 
 being fhivery, and breaking into fmall pieces, unfit for the 
 making of flates : it is alfo equally bad, where veins of quartz 
 r limeflone occur. 
 
 The 
 
E A S D A L Ev 1-95 
 
 The iiland is now cut very low, excepting a fmall portion at 
 the fouth end ; and levels hav been made out to the fea, to 
 carry off the rain water. As the greater part of the ifland is 
 now upon a level with the fea, it is plain that the raifing of 
 Hates muft be abandoned, or continue to be worked at a con- 
 fiderable expence by means of machinery ; which would pro- 
 bably be a bad plan, when we confider the extent and excel- 
 lence of the rival quarries at Ballyhulim J. The mofl judici- 
 ous arrangement would certainly be, to open more extenfive 
 quarries in the neighbouring iftes of Luing and Seil, where, in 
 all probability, after the ground is properly cleared, good flates 
 may be foundo 
 
 The ardefia in this ifland was firft quarried about one hun- 
 dred years ago ; but was for a long time of little importance, as 
 fandftone flag and tiles were generally ufed for roofing houfes. 
 As the ufe of flates became more prevalent, the quarries were 
 enlarged ; and the prefent managers having obtained a very fa- 
 vourable leafe, thefe quarries have been wrought to fo great an 
 extent, that 5,000,000 flates are annually fhipped from this 
 ifland. The number of workmen is at prefent about 300 ; and 
 
 B b 2 they 
 
 J The quarries at Ballyhulifti employ about 200 men ; and the flates r.;* 
 font to Leith, Clyde, England, Ireland, and America. 
 
196 o B A N. 
 
 they are divided into quarriers and day labourers. The quar- 
 riers are paid annually at a certain rate for every thoufand 
 flates : from lod. to ijd. I believe, as their work has been at- 
 tended with more or lefs difficulty. The day labourers are 
 employed at the company's expence in opening new quarries, 
 and have from lod. to is. a day. 
 
 O B A N. 
 
 AS the weather continued very pleafant, we preferred going 
 to Oban by fea, in place of the circuitous rout by land. 
 Having procured a boat, we left Seil, with a fine breeze ; our 
 voyage was agreeable, with fcenery often ftriking ; on one 
 hand, was the lofty coaft of Mull, extending from Loch Bay 
 to Crogan, all apparently bafaltic 5 on the other, the mainland 
 rifing into fmall hills, alfo with a bafaltic afpect. Having 
 patted the ifle of Kerrera, which lies acrofs the bay of Oban ; 
 in a fhort time afterwards, we landed at the village. The bay 
 of Oban is of a femicircular form ; is from 12 to 14 fathom 
 , with good anchoring ground, and will contain 500 fail 
 
 of 
 
O B A N. 197 
 
 of merchant mips. The village is pleafantly fituated at the 
 upper part of the bay, a flation excelleiitly adapted for the 
 fifhing. The decline of this branch of trade, has indeed been 
 unfavourable to the rife of Oban ; but it is, notwithftanding, 
 the mofl confiderable village on this part of the coaft, con- 
 taining about 586 inhabitants. It is to the exertions of the 
 two brothers, the MefTrs. Stevenfons, who fettled here in 1 778, 
 that Oban is chiefly indebted for its prefent flourifhing con- 
 dition. 
 
 As we were anxious to proceed on our journey through the 
 iflaiids, well knowing the variable flate of the weather in thefe 
 highland countries ; we took but a glance of the rocks in the 
 neighbourhood of Oban. The flrata immediate] y upon the 
 fhore, on both fides of the town, are formed of dark blue co- 
 loured argillaceous fhiftus ; immediately above this, I obferved 
 in fome places bafalt, or bafalt porphyry. As we approach 
 Dunolly caftle, which forms the extreme point of land upon 
 one fide of the bay, vafl rocks of breccia appear ; and thefe 
 continue all the way to Dunftaffnage caftle *. Both thefe caf- 
 
 tles 
 
 * At Boregonium, which is a few miles from Dunflaffnage, there are, accor- 
 ding to Dr. Garnet, undoubted volcanic appearances, Dr Walker informs me ? 
 that the pumice, which Dr. Garnet mentions, is the fcoriae from the iron fur-, 
 naces, which were worked at that place by our anceflors, 
 
O B A Nv 
 
 ties arc built upon rocks of breccia, which is compofed of va- 
 rioufly fhaped pieces of granite, micaceous fhiftus, and fand- 
 ftone, connected by an arenaceous breccia. Upon different 
 parts of the coaft, and in the interior of the country, this breccia 
 feems to lye upon a red coloured argillaceous fandftone. From 
 Oban, the country becomes gradually higher as we approach 
 the great mountain of Cruachan ; and the ftrata alfo change. 
 If we walk by the Inveraray road, we obferve wacken, and 
 fometimes bafalt covering the fandftone ; and in many places 
 great rounded mafTes of granite, which formerly conftituted 
 part of the breccia, are to be feen fcattered about. Thefe 
 fandftone and bafalt ftrata, probably continue until ardefia 
 and micaceous fliiftus, which form the lower region of 
 Cruachan, make their appearance ; and this is fucceeded by 
 the granite, which rifes through it, and continues to the top 
 of the mountain *. 
 
 Mr. St. Fond has given us a chapter upon the lithology of 
 Oban, in his travels through Scotland ; but he has here, as 
 ufual, intermixed his theoretical fpeculations with the defcrip- 
 tions of th ftrata. He denominates the blue argillaceous 
 
 fhiftus 
 
 * I owe this information, with regard t-o Cruachan, te my friend Mr. Cad- 
 dell. 
 
VOYAGE TO MULL* 199 
 
 4-hiftus of Oban, a limeftone ; this, he fays, is an aquatic pro- 
 duction ; but the bafalt, he imagines to have been fuperindu- 
 ced in a melted ftate under water, which prevented the lime- 
 {lone from being altered ; and further, he defcribes the breccia 
 as a volcanic matter, which has been thrown up in a fimilar 
 mariner with thofe volcanic erruptions " in which water heat- 
 " ed to the higheft degree of ebullition, enters into concourfe 
 " with fire, and the different elaflic emanations generated by 
 " fubterraneous combuftion." I muft confefs my inability 
 to comprehend this explanation ; at any rate, it is now ufe- 
 lefs to attempt fupporting this part of the volcanic theory, as 
 it has been demonftrably refuted by Mr Kirwan, in his paper 
 on bafalt, 
 
 VOYAGE ro MULL. 
 
 HAVING arranged every thing for the continuance of our 
 journey, we fet fail for the ifland of Mull, which is about 15 
 miles from Oban. In our way, pafTed near to the ifle of Ker- 
 rera, of which Faujas gives the following account. " A part 
 " of this ifland is volcanic $ on the. coaft fronting Mull, there 
 
 " are 
 
2JOO VOYAGE TO MULL. 
 
 " are collections of compact lavas in mafTes, and in large cur- 
 
 " rents. This bafaltic lava appears fometimes in the form of 
 
 " prifms, which are not very regular ; at leait in the places I 
 
 " had an opportunity of examining. I alfo found fome rocks 
 
 " of micaceous fhiftus of a whitifh colour, and others which 
 
 " were greenim, with a porous texture. Thefe fhiftus, or 
 
 * gneifs, are compofed of quartz, fteatites, and fmall fcales of 
 
 " mica. 
 
 " Near the rock of micaceous fhiftus, there is found com- 
 " mon flate of a deep grey colour, approaching to black ; the 
 " beds of which are almoft even with the ground ; quar- 
 " ries might eafily be opened here with great advantage to 
 " the country. They would even become an object of com- 
 " merce. Among the flate, there are found fome brilliant 
 " pyrites, the cryftallizations of which are cubical J." 
 
 We next paffed the ifland of Lifmore, which is about nine 
 miles long, but very narrow : it is according to Williams, com- 
 pofed entirely of limeflone, .traverfed with bafaltic veins. Dr. 
 Mitchell fuppofes that the limeflone belongs to the tranfition 
 
 rocks. 
 , 
 
 $ Travels through Scotland, &c. 
 
VOYAGE TO MULL* 201 
 
 rocks (uebergangsgeburge). From the greater part of the ifl- 
 and being formed of limeftone, at the fame time well fhelter- 
 ed, it is rendered one of the mod productive fpots in the 
 Highlands. After a fhort voyage, we came clofe in with the 
 coafl of Mull, but on account of the tide, we were obliged to 
 pull along the more for fome miles, which gave me an oppor- 
 tunity of examining the more-, until we landed on the coafl: 
 below Achinacraig. 
 
 . 
 
 G c MULL. 
 
MULL, 
 
 CHAP. XIII. 
 
 Outline of the MINERALOGY of the I/land of MULL. 
 
 i 
 
 A HIS ifland is about 22 miles long, and 16 miles broad. It 
 is reckoned by fome writers to be the Maleos of Ptolemy * j 
 and Cambden is of opinion, that it is the Mille of Pliny J. On 
 the north, it is bounded by Ardnamurchan ; on the eafl, by the 
 rugged flerile looking mountains of Morven, and the ifle of 
 Lifmore ; to the fouth, are the ifles Jura, Scarba, and Slate ifles ; 
 and on the weft ? I-kolmkill, Staffa, Coll, and Tiree. 
 
 The coafl of this ifland is much diverlified in its appearance ; 
 in many places we obferve a great extent of fleep and bold 
 
 rocky 
 
 * Campbell's Political Survey, vol. I. p. 599. 
 t Britannia, p. 848, 
 
ft fj t L. 203 
 
 rocky ihore's, forming tremendous precipices ; particularly 
 upon the fourth flrore rieatf Loch Buy. Often the fhores are 
 low, but ftill rocky and dangerous ; fekloin is there any fandy 
 beach, the coafl being generally covered by the immenfe maf- 
 fes that have fallen from the neighbouring cliffs. It is low, 
 however, towards the S. W. extremity which is called the 
 parifh of Rofs. 
 
 The ifland is very mountainous, and fome of the mountains 
 rife to a confiderable height ; particularly Ben-More, which is 
 reckoned the Jiigheft in the ifland. It is much interfecled 
 upon the weft fide, where there are two confiderable lochs or 
 arms of the fta, called Loch Skriddan, and the other Loch- 
 na-gaul, 
 
 Acnriacraig, where we landed from Oban } 
 is fituated at a little diftance from the fea fhore, with fbme 
 confiderable flats near it ; and thefe being cultivated, and in 
 fome places wooded, enliven the fcene confiderably. The 
 rocks are in general bafalt and wacken, which are in many 
 places traverfed with bafaltic veins. The occurence of veins 
 of bafalt croflmg a fimilar rock, feems to be very rare ; as I 
 am well informed, that foreign mineralogifls, have never ob- 
 ferved fuch appearances. Mr Faujas St. Fond, in defcribing 
 
 C c a this 
 
2O4 MULL. 
 
 this part of the ifland, feems to have been much flruck with 
 one of thefe veins, which he compares to a circus ; and has 
 given a long detail of the way in which it may have been 
 formed. This was all very unnecefTary, as this vein does not 
 differ from many others to be obferved in the ifland ; and the 
 idea which Mr St. Fond raifes of its magnificence, is far 
 flretched it is trifling when compared with the grand ap- 
 pearances upon the coafls of Ida and Jura. As we advance 
 towards Loch Speleve, the cliffs upon the more do not increafe 
 much in height ; but there are land cliffs behind them con- 
 fiderably higher. The rocks are almoft entirely of bafalt and 
 wacken, all the way to the loch, as alfo the hills in the neigh- 
 bourhood. About half a mile from Achnacraig, I obferved 
 a ftratum of blue coloured limeftone, covered with calcareous 
 fandftone ; but thefe flrata are vifible only for about 80 feet, 
 when they are loft under the bafalt. This limeftone contains 
 in it belemnites, and is therefore to be reckoned with the 
 tranfition rocks ; and is what Mr Kirwan confiders as the moil 
 ancient of the fecondary ftrata *. 
 
 As there is a good road, along the ftiore of the ifland, from 
 Achnacraig to Tobermory, we preferred it to coafting by fea. 
 
 Having 
 
 * Geological EfTays, p. .226. 
 
MULL, 205 
 
 Having left Achnacraig, we parTed, for about a mile, through 
 little wooded glens, which are extremely pleafant, particularly 
 in a country where wood is truly a rarity. The ftrata ftill 
 continued bafaltic, excepting at one place where I obferved a 
 flratum of blue-coloured limeflone cropping thro' the foil. As 
 we journeyed along the fhore at the bottom of the high hills 
 which bound it, I judged it necefTary to examine fome of 
 them to their fummits ; that I might obtain more diftincl in- 
 formation of their nature, and have an opportunity of furvey- 
 ing the neighbouring country. The day being fine, we began 
 to afcend a high hill, about two miles from Achnacraig. The 
 afcent was very fteep, until we reached an extenfive plain feve- 
 ral hundred feet above the level of the fea. The ftrata, to this 
 height, were bafalt and greenftone, and both frequently tra- 
 verfed with bafaltic veins. The greenftone, even at a con.fi- 
 xierable diftance, has a fingular fcorified-like afpecl, from the- 
 felfpar having decayed, and the remaining hornblende, ref ena- 
 bling a dark green, or bla*-cki(li cellular mafs, not unlike the fco- 
 ria of an iron furnace. The plain was covered, to its whole ex- 
 tent, with loofe ftones of an iron-brown colour. Hardly a 
 trace of vegetation could be feen ; and the deep filence of this 
 defert was disturbed only by the rufhmg of the cold piercing 
 wind acrofs the mountain. The loofe mafTes of rock jufl 
 mentioned, I found to be of breccia, which is compofed of va- 
 
 rioufly 
 
206 M U L L. 
 
 rioufly fhaped mafTes of quartz, earthy felipar, hornilofle, and 
 granite, connected by a bafalt or wacken ? bails J. It is proba- 
 bly of the nature of bafalt tuff; which, according to German 
 mineralogifls, is a rock with a bafalt or wacken bafis, having, 
 immerfed, fragments of other rocks, as granite, quartz, &c. 
 We now walked towards the fummit of the mountain, which 
 we reached, after having paffed over a fucceflion of fmaller 
 plains, or platforms, feparated from each other by fteep bafakic 
 craigs. The fummit is compofed entirely of bafalt, which con- 
 tains much hornblende ; and this rock has the property of re- 
 verfing the compafs at a considerable diftanee, and even in de- 
 tached pieces. From this elevated ntuation we had a fine view 
 of the ifland, Towards Tobermory the mountains appear to- 
 become gradually lower ; but, upon the weft fide, a tremen- 
 dous groupe of varioufly-fhaped mountains appears before us, 
 and among them Ben-more rifes with much dignity. The 
 glens, which we obferved run from the mountain, are of great 
 depth, very fteep, and apparently compofed of ftrata of ba- 
 falt and greenftone. Thefe ftrata, however, run in a direction 
 contrary to that of the vallies, which intimate that the land 
 
 has 
 
 t I am oMiged to marie this doubtful, as I unlodbily loft the fpecimens, 
 which would have enabled rae r to determine the nature of the 
 
MULL. 
 
 207 
 
 has funk down, as we have already explained in our fpecula- 
 tions upon the formation of the bed of the Clyde. We now de~ 
 fcended from the mountain, but by a different route from that 
 which we followed in afcending ; and although it was 
 fatiguing and difficult, it afforded us an opportunity of obferv- 
 ing the bafalt and greenftone alternating with each other, and 
 elevated nearly to an angle of 45. 
 
 We now continued our journey along the Tobermory road, 
 with hills upon one hand, but in a fhort time the land on the 
 other became low, ftretching out towards the found of Mull, 
 to a point on which is fituated Duart Caftle. The hills, as alfo 
 the hills near the more, are ftill bafaltic ; but we were informed 
 that there is, at the caftle, a great ftratum of limeftone, which 
 affords cornua ammonis and {hells. As we approached Achna- 
 crofh, we obferved, upon the more, ftrata of argillaceous fand- 
 ftone, with interfperfed bituminous and coaly matter, as is 
 ufually the cafe with fandftone in coal countries ; and, at a lit- 
 tle diftance, a rock, which feems to be analogous to greenftone, 
 of which a particular defcription is , given in the following 
 chapter. 
 
 From this to Arros die mores are low, but the hills rife to a 
 confiderable height j and both are formed of bafalt, greenftone, 
 
 and 
 
and wacken, which I fomctimes obferved traverfed with bafal- 
 tic veins. The bafalt, but more particularly the wacken, con- 
 tains zeolite, which is either compact, fibrous, or cryftallized. 
 I regretted extremely that I had not an opportunity of examin- 
 ing this part of the country more particularly, as there can be 
 ao doubt but that it would afford much curious information 
 with regard to the rocks of trap formation. I have however 
 to offer as an apology, (if fuch a thing is becoming,) that, in 
 travelling over all that track of country, we were envelopped 
 in thick clouds and pouring rain ; fo that the few obfervations 
 as to the nature of the hills, were made by examining the de- 
 bris in the ravines, or were now and then amfled by the par- 
 tial difperfion of the clouds. I may now alfo remark, that, 
 in travelling thefe countries with a view to the particular ex- 
 amination of their mineralogy, it will be abfolutely necefTary 
 for the traveller to carry along with him a tent, and other con- 
 veniences, fo that he may encamp among the mountains, and 
 examine them leifurely, and with that fcrupulous accuracy 
 which the importance of the fubject requires. 
 
 At Arros there is a fmall colonade of bafalt, upon which 
 there are ftill the remains of an old caftle, once inhabited by 
 Macdonald prince of the Ifles. In the bed of the river of Arros, 
 (a fmall flream of water which comes from the neighbouring 
 
 bafaltic 
 
f.1 U L L, 
 
 209 
 
 bafaltic hills,) I obferved numerous blocks of granite, fimilar to 
 v thofe upon the hill near Achnacraig. Thefe blocks feem to be 
 derived from a bafalt tuff fimilar to that obferved near Achna- 
 craig ; and it is probable that fuch a rock may be difcovered in 
 the neighbouring hills. It will be an object worthy the atten- 
 tion of future travellers, to afcertain, whether this bafalt tuff-? 
 merely covers the bafalt, as has been obferved by Reufs in the 
 mountains of Bohemia, or alternates, as is the cafe with the 
 bafalt tuff in the ifle of Canna, and in other parts of Scotland. 
 It matters not in which of thefe fituations it be found : it is 
 flill to be confidered as a fecondary rock, and, like thefe, te 
 have been deposited from an aqueous fluid. Probably fome 
 may think that thefe maffes have been feparated from the de~ 
 compofing bafalt itfelf, as it fometimes contains pieces of gra^ 
 nite. This, however, is an appearance fo rarely to be obferved 
 in this ifland, that I can hardly imagine the granite blocks to 
 'be derived from that fource. 
 
 'ProfefTor St. Fond has fpeculated upon this fubjedl, as he obfer- 
 ved fimilar appearances in different parts of the ifland. For the in- . 
 formation of my readers, I will extract the following paffage from 
 Jiis Travels. " Thefe lumps of granite (fays he) may have been 
 ** ejected from granite quarries, which perhaps exifled at great 
 
 D d " depths 
 
2 IO MULL* 
 
 " depths under thefe ancient volcanoes, by the cxplofions which 
 " took place at that epoch, when extenfive corabuftions waited 
 " thefe countries, and formed groups of iflands, which ieem 
 " to have the fame origin. 
 
 " It is, betides, within the verge of pombility, that thofe 
 " parts of the mountains where they are now found were not, 
 " at that period, elevated fummits, but rather formed part of 
 " the bottom of the fea, and that thefe granite blocks w r ere 
 " rolled from a diftance by the currents. It is poflible that 
 " circumftances of fubterraneous explolion, equally terrible 
 *' with thofe which formed the ifle of Santorini in the Archi- 
 " pelago, or Montenove in Italy, may have raifed up the bot- 
 " torn of the fea into volcanic peaks ; or, if it fhould appear 
 " more plaufible to fome, we may refer to a period when 
 " mountains ftill higher were covered by the fea : a fadl, which 
 " cannot be doubted, fince marine bodies are found in great 
 " abundance in beds of limeftone, or clay, fituated on the Alps 
 " or Appenines, at a height three or four times greater." 
 
 At Arros, we changed our route ; and in place of going on 
 to Tobermory, we took our courfe acrofs the ifland to Luggan 
 Ulva. The road, which is but indifferent, leads us among 
 Mis of no considerable height, to the plain of Knock, litu- 
 
 ated 
 
MULL, 2U 
 
 ated at the head of Loch-na-gaul. The hills are compofed 
 of ftrata, of bafalt, and wacken ; which are fometimes traverfed 
 with bafaltic veins. The loch, which is of conliderable ex- 
 tent, is bounded upon one fide by the mountain of Ben-more, 
 with other neighbouring hills, that extend towards the fea 
 more, forming lofty crags, not unlike thofe of Salifbury Hill 
 near Edinburgh ; on the oppofite fide, are the hills that bound 
 the road which leads towards Luggan Ulva. Ben-more, which 
 is the highefl mountain in the ifland, is of confiderable mag- 
 nitude ; and Mr St. Fond remarks that it has much the ap- 
 pearance of the famous volcanic mountain Vesuvius. We 
 did not afcend this mountain, fo that I cannot give any ac- 
 count of the rocks of which it is compofed ; but I have 
 had the opportunity of examining fpecimens brought from 
 it by Mr. Caddel. It would feem from thefe, that it 
 does not differ from the other parts of the ifland which 
 I have already defcribed, being compofed of bafalt and 
 greeiiflone ; even to its very fummit. This agrees pretty 
 nearly with the obfervations of Mr. St. Fond, who tells 
 us, that it is compofed of lava ; that is bafalt. We purfued 
 our journey along the oppofite fide of the loch, which led us 
 to Luggan Ulva ; I found little variety of rock ; the bafalt 
 and wacken flrata traverfed with bafaltic veins, flill continu- 
 
 D d 2 ing 
 
fI2 MULL. 
 
 ing. The wacken, however, affords many beautiful fpeci- 
 cimens of zeolite, and alfo a rarer foflil, the prehnite. 
 
 Nearly oppofite to Luggan Ulva, lies the iinall iiland of Ul- 
 va, which is evidently compofed of the fame rocks ; and far- 
 ther diflant, is the ifle of Geometra, which is alfo bafaltic. 
 
 As foon as the weather, which had been for fome time tern- 
 peftuous, became moderate, we crofTed at die mouth of Loch- 
 na-gaul, and landed immediately under the high cliffs, which 
 we had feen from the head of the loch. We now walked a- 
 long a confiderable extent of fhore, which is bounded by lofty 
 crags, compofed of bafalt and wacken flrata, and both tra- 
 verfed by bafaltic veins, which run in very different direc- 
 tions. Immediately upon the fhore, I obferved flrata of argil- 
 laceous fandftone, and fandflone breccia ; and we were told, 
 that both coal and lead had been difcovered in feveral places 
 in the neighbourhood. About 200 feet above the level of the 
 fea, on the tract which takes us acrofs the mountains to Loch 
 Skriddan, our attention was arrefled by the appearance of a 
 curious fpecies of breccia. It is compofed of fragments of 
 quartz, micaceous fhiflus, compact limeflone containing flint, 
 and the whole cemented by an arenaceous bafis ; fometimes 
 it has a calcareous bafis, when it has a yellow colour, owing 
 
 to 
 
MULL, 
 
 to a decomposition of the limeflone. Below the breccia we 
 obferved a compact micaceous fhiftus. In going higher up, 
 we had a more diftin<l view of the ftratiiicadon ; which is as 
 follows : i. Micaceous miftus. 2. Breccia covering the mica- 
 ceous fhiftus. 3. Sandftone, more or lefs of the nature of brec- 
 cia, covering the breccia. 4. And higher up the mountain, 
 appeared the bafalt ; but we could not determine correctly its 
 iituation with regard to the ftrata juft mentioned. The ap- 
 pearance of micaceous miftus in a bafaltic country, is a iingu- 
 lar phenomenon, well deferving the attention of future travel- 
 lers. 
 
 From this, we continued our journey in the direction of 
 the great Bourg head, (a lofty promontory at the entrance of 
 Loch-fkriddan,) over which we crofTed, and defcended to the 
 fhore of Lochleven or Skriddan. The ftrata in this, tract 
 are ftill bafalt and wacken ; and both are traverfed with 
 bafalt or wacken veins ; and contain much zeolite. I acci- 
 dentally difcovered a piece of black pitchftone porphyry, fimi* 
 lar to that which is found in Glencloy, in the ifland of Arran. 
 This Loch, which is pretty extenfive, is bounded on both fides 
 by bafaltic hills ; and at its upper extremity, there is a grand 
 groupe of bafaltic hills that congregate nearly to the oppofite 
 lide of the ifland, about Loch Spelve. We crofTed the loch 
 
 near 
 
MULL. 
 
 near its month, and walked along the more, which is low and 
 bafaltic, until we approach Artown, when it juts out into a 
 promontory, which prefents feveral very beautiful ranges of 
 bafaltic columns. Upon the N. E. fide of the promontory, we 
 obferved, immediately upon the more, a flratum of coal, which 
 has for its roof a mafs of imperfectly fhaped bafaltic pillars ; 
 and its floor is alfo bafalt. The flratum is about 1 2 inches 
 thick ; and fometimes interpofed between it and the bafalt 
 there is a thin layer of blaes (fhiftofe clay), which is mixed 
 with the coal, and deteriorates its quality. We could only ob- 
 ferve the ftratum running for a fhort way, as the fea has 
 thrown up debris along the bottom of the rocks, where the 
 coal is iituated : yet we were told, that it is to be feen crop- 
 ping out upon other parts of the coaft. As the country is low 
 in the neighbourhood of the coal ; it is certainly worthy the 
 attention of the proprietors, to endeavour by trials fkilfully 
 conducted, to know how far this flratum extends ; and whe- 
 ther other flrata exifl near to it. It has been objected to this, 
 that if any trials mould be made, it would merely fatisfy cu- 
 riofity, without the probability of fuccefs ; as it is imagined 
 that bafaltic rocks are very unfavourable to coal. We cannot 
 deny the fact, that coal is feldom fo regular under bafalt, as un- 
 der fandftone ; yet, in a country where the beft part of the 
 year is wafted in the operations of cutting and drying peat, 
 
 there 
 
MULL. 2 I C 
 
 ihr 
 
 there can be no doubt, that the difcovery of a bed of coal, 
 (although it mould not be fo extenfi ve as thofe in the fand- 
 ftone countries), would be of the higheft importance. 
 
 We are further encouraged to make regular trials, when we 
 know that in other parts, confiderable beds of coal have been 
 found among fimilar rocks. Thus at Borrowftounnefs, accor- 
 ding to Mr. Williams, we find thick flrata of bafalt interpofed 
 between beds of coal, which are worked to a great extent : and 
 in the Bathgate hills, coal and bafalt alternate with each 
 other *. In Bohemia, according to Reufs, coals inlaid in ba- 
 falt are worked f ; in the Faroe iflands, coal is found in ftra- 
 ta among bafalt : at MenTen, in Heffia, a bed of coal from 6 
 to go feet, is found covered with bafalt, to the height of 600 
 
 Mr Mills, in the paper which I have already mentioned, 
 when defcribing Ifla and Jura, gives an account of a remark- 
 able appearance near Artown, which unluckily I had not an 
 opportunity of viewing. As it will.be interesting for future 
 
 travellers 
 
 * Williams's Mineral Kingdom, vol. I. p. 70.. 
 
 f Mineralogifche Geographic von Boehmen.. 
 
 J Haidinger Gebergsarten. ." 
 
 Ij'Bergm. Joum. 1792, 319, andKirwan Geological. Effays,.p. 311. . 
 
2l6 MULL. 
 
 travellers, 1 fhall here infert his defcription, and make a few 
 obfervations on it. " About a quarter of a mile from the 
 " fpot where the bearings were taken, is a deep glen, running 
 " N.ME, to the fea. It is about 30 yards in length, and 20 in 
 " breadth. The ftrata are difpofed in the following manner : 
 * c The uppermoftis 10 yards of lava, with horizontal divifions, 
 " and vertical joints, taking the form of rude pillars. Under 
 
 " this, is a horizontal bed of perfectly vitrified fubftance, 
 J " which appears to have been a fliale, and is from i to 2 inches 
 " in thicknefs. Beneath this, is about three yards of filiceous 
 " gravelly concrete ; below which, are horizontal beds of in- 
 " durated marie of various thicknefs, from 6 to 12 inches. 
 " The whole of thefe beds taken together, are about four 
 <c yards ; and there is a large fiffure in them, on the weft fide of 
 " the glen. Laftly, are 10 yards of rude lava, containing fpecks 
 " of quartz, and mica unaltered ; pieces, apparently of gra- 
 " nite ; and in fome, nodules of calcined chert. The whole is 
 " incumbent on regular bafah pillars of various dimenfions, 
 " from 1 8 to 6 inches in diameter, varying in their number of 
 " fides ; fome having 5, fome 6, others 7, &c." This gentle- 
 man, by denominating his foffils upon -theoretical principles, 
 .has thrown a confiderable degree of obfcurity over his def- 
 cription. To me, the following appears to be the true ac- 
 count ; 
 
 Lava 
 
MULL* 
 
 217 
 
 Lava. This is probably bafalt : for he appears to ufe this 
 term in different parts of his memoir, as expreflive of all 
 kinds of bafalt. 
 
 Vitrified fubftance* This is certainly the fame with the black 
 pitchflone which we have already obferved upon the 
 oppofite fide of Loch Skriddan ; and which we were 
 told had been found near Bunefan and at Bennenoch. 
 
 Siliceous gravelly concrete* Probably a coarfe fandflone ? 
 If this fuppofition be correct, it is another example of 
 pitchflone being contained between fandftone and a rock 
 of trapp formation, fimilar to that I fufpedled in the ifl- 
 and of Arran, 
 
 Indurated marie. This is probably the fame with the lime- 
 flone, which contains flint upon the coaft between Loch- 
 na-gaul, and Loch-Skriddan. 
 
 Calcined chert. This is likely hornflone ; which, however, 
 is a rare occurence in bafalt. Emmerling. R 3. 187. 
 
 We now left Artown, and walked on to Bunefan ; the coun- 
 try flill continued to be formed of bafalt, containing many 
 
 E e beautiful 
 
2lS MULL. 
 
 beautiful fpecimens of zeolite pafling to chalcedony, and alfo 
 prehnite. Near to this place, there is a little river which marks 
 the termination of the fecondary, and the beginning of the 
 primary flrata. Upon the eaft bank, I obferved the bafalt ; 
 but upon the weft, the ftrata are of micaceous ihiftus. I en- 
 deavoured, as far as my fliort time would allow me, to difco- 
 cover the junction of the ftrata, but was not fo fortunate as to 
 obferve them in actual contact : yet, I think it not improbable, 
 that the bafalt lies upon the micaceous fhiftus. This fuppo- 
 iition, may to fome appear to invalidate the obfervation I have 
 made in a former part of the work, viz, that bafalt is never 
 found among primary ftrata. This is by no means the cafe ; 
 for here, the bafalt forms a great extent of country ; and in 
 fome places, as at Artown, it contains coal ; fo that, although 
 it lies on micaceous ihiftus, without any intervening breccia, 
 it cannot be conlidered as primitive. It appears to me a good 
 mode of afcertaining whether a rock be primary or fecondary, 
 to examine whether it alternates with ftrata decidedly primi- 
 tive ; and whether, at its junction with the primary ftrata, it 
 feems to be in part intermixed, and partly afTuming the na- 
 ture of thefe ftrata ; thus intimating that they have been de- 
 -pofited at the fame time. 
 
Jtt U L 
 
 219 
 
 The micaceous fhiftus extends quite acrofs this part of the 
 ifland ; and continues for about a mile after we leave Bunefan, 
 in going to the fouthern extremity of the ifland. In this extent 
 it is fomewhat varied in its appearance, being more or lefs com- 
 pact, fometimes containing garnets, and traverfed with bafaltic 
 veins. In other places, as upon the iide of Loch-Artineg, I ob- 
 ferved it alternating with ftrata of quartz, from one to three 
 feet thick, and which broke into thin layers. 
 
 To the micaceous fliiflus fucceeds beautiful red granite,, 
 which continues to the extremity of the ifland, forming low, 
 round-fhaped hills. This part of the ifland, which is called 
 Rofs, is low, interfered with fmall lakes, and diverfified with 
 natural wood. The mores are low, but rugged and broken ; 
 and in fome places we obferved large empty fiflures, which ap- 
 pear to have been formerly filled, either with an earthy matter, 
 as bafalt, or with a metallic ore. The granite appears to be 
 difpofed in beds, as we have already mentioned to be the cafe 
 in Arran. Dr Walker, many years ago, obferved this difpofi- 
 tion of the granite, not only in Mull, but in many other parts 
 of Scotland ; which is a further and decifive proof of the fal- 
 lacy of La Metherie's obfervations. The granite fometimes 
 fplits into rhombs, and what is more uncommon, into columns, 
 not unlike bafalt. This appearance of columnar granite is, 
 
 E e 2 I 
 
220 MULL. 
 
 I believe, rather a rare occurrence ; at lead I do not find it 
 mentioned but by Reufs, who difcovered beds of granite fplit 
 into columns, not unlike bafalt *. In many places I obferved 
 bafaltic veins traverfing the granite ; and thefe are of various 
 fizes, and run in very different directions. Upon the fide of 
 Loch-Artineg I obferved a rein running through the granite, 
 vifible for nearly a mile, and often branching out in different 
 directions. Sometimes I obferved pieces of granite included in 
 the bafalt veins ; and in one inftance I obferved the granite, 
 which bounds the fide of the vein, mixed with the bafalt. 
 
 The fouth fide of Rofs continues to be formed of granite 
 and micaceous fhiflus, until we come upon a line with Bunefan, 
 when the bafaltic rock commences. From this to Loch-Buy 
 the country and coaft are principally formed of bafalt and 
 wacken, excepting at Gribun, where fandftone and limeftone 
 are to be obferved, and at Carfeg, where there are confiderable 
 appearances of limeftone. The rocks upon this coaft, in fome 
 places, rife to a moft tremendous height, particularly at Inni- 
 more, where we obferve many ranges of bafaltic columns 
 
 towering 
 
 * Mineralogifche Geographic von Boehmen, Erfter band, 120. I think 
 .:. Sauffure, f jrae\vhere in his Travels, mentions a fimilar appearance. 
 
MULL. 221 
 
 towering above each other with vafl magnificence. This flu- 
 pendous fcene is rendered doubly interefling when its rocks are 
 obfcured by a tempefl : the darning of the furious ocean be- 
 low, and the fall of vail cafcades from the rugged fummits, 
 feen dimly thro' the clouds, prefent a fcene of uncommon 
 fublimity. 
 
 There are feveral appearances of coal upon this coaft, but 
 the mod remarkable is that upon the hill called Beinan-ini. 
 This hill is compofed of horizontal flrata of bafalt and wacken, 
 which alternate, and rife to the top of the hill like great natu- 
 ral terraces. The coal appears in the bed of a rivulet upon the 
 fide of the mountain ; is about three feet thick, and is imme- 
 diately covered by bafalt. It is one of the greatefl flrata of 
 coal that has yet been difcovered in the Weftern Iflands, and 
 confequently is worthy of particular attention. Several trials 
 have been made with a view to the working of it ; but of a na- 
 ture fo trifling, that they can deferve notice only as mowing 
 how little the importance of the fubjedl has been underflood. 
 Sir David Murray of Stanhope, fo far as we can learn, was 
 the firft gentleman who feems to have been aware of its confe- 
 quence ; for, about the beginning of the lafl century, he pur- 
 chafed this hill folely on account of the coal which it contains. 
 He propofed to open the flratum in a very exteniive manner, 
 
 and 
 
222 MULL. 
 
 and to work it until he mould be fatisfied whether it was prac- 
 ticable to continue it to advantage. This fchcme was unfortu- 
 nately frtiflrated by a failure in his affairs, which made him 
 flop working a fliort time after he had begun. Since that 
 period, the property has come into the pofTeffion of Sir James 
 Riddell of Ardnamurchan, who feemed inclined to continue 
 the work of his predecefTor ; but the bufinefs appears to have 
 been committed to peffons who were fatisfied with making 
 very fuperficial and unfatisfaclory trials. This is much to be 
 regretted, when we confider, that the eftablimment of coal- 
 works, in fo centrical a fpot of the Hebrides, would not only 
 be a great comfort to the inhabitants of the iilands, where peat 
 is fcanty, and not to be procured without difficulty, but wouM 
 make all the operations of the farmer to go on with new life, 
 and would, in every way, contribute much to the improve- 
 ment of the Weftern Iflands. It is therefore worthy of the 
 public fpirit of the highland proprietors, to form a general 
 fubfcription, fo as to enable them to determine the queftion, 
 whether the coal of Mull can be worked fo as to be advanta- 
 geous to the inhabitants of the weft coaft of Scotland and the 
 Hebrides. 
 
 Having fpent a few days in Rofs, which gave us an oppor- 
 tunity of examining I-cdum-kiBy we walked again to Locii- 
 
 Skriddan, 
 
M V L &. 223 
 
 Skriddan, where we took a boat, and rowed along the lofty 
 coafl to Luggan-Ulva. In ovir way we pafled the fniall ifland 
 of Inch-Kenneth, remarkable not for its variety of foflils, as it 
 is compofed of red-coloured fandftone and limeftone ? but for 
 the interefting account which Dr Johnfon has given of the 
 happy family of Sir Allan Maclean. 
 
 We now walked from Luggan-Ulva to Torloifk, the feat of 
 the late worthy Mr Maclean. The more is rugged ; but the 
 country is in feveral places confiderably cultivated, particularly 
 near Torloifk. The rocks, all the way, are of bafalt and wac- 
 ken ; and both contain beautiful fpecimens of zeolite, which 
 are generally fibrous, and fometimes appear patting to chalce- 
 dony. I obferved, in fome places, a red-coloured wacken al- 
 ternating with the bafalt. I alfo remarked blocks of granite 
 fimilar to that we obferved at Arros. 
 
 From Torloifk to the northern extremity of the ifland, the 
 fame bafaltic rock continues ; and, fo far as I could judge, 
 the whole of the coafl towards Tobermory is of the fame 
 nature, 
 
224 MULL* 
 
 GENERAL OBSERVATION. From this rapid and imperfedt 
 outline, it appears, that a great portion of this ifland is com- 
 pofed of rocks of trap formation, and that they even form 
 many of the high hills. The primary ftrata, upon the other 
 hand, form a very fmall part ; being confined (as far as my 
 experience goes) to the parim of Rofs, and the fmall patch 
 upon the fhore between Luggan-Ulva and Loch-Skriddan. 
 
 MULL. 
 
CHAP. XIV. 
 Dcfcription of the FOSSILS mentioned in the preceding Chapter. 
 
 JlT may appear unneceflary again to introduce an account 
 of the ardeiia tegularis, as I have defcribed it in Arran and 
 Jura. The defcription which now follows, however, is tHat 
 of one of the moil celebrated flates in Britain, and therefore 
 it fhould not be omitted. 
 
 ARDESIA TEGULARIS-; from Eafdale, 
 
 
 
 Colour. Dark blue. 
 Ijiflre. Little mining.. 
 Tranfparency. None. 
 Frafture. Perfectly llaty. 
 
 "F f . Fragments. 
 
226 MULL. 
 
 Fragments. Tabular. 
 
 Hardnefs. Yields pretty eafily to the knife. 
 Streak. Of a lighter colour than the flate itfelf ; and the pow- 
 der does not feel^greafy. 
 Adhefion. Does not adhere to the tongue. 
 Smell. Pretty ftrong earthy fmell when breathed on. 
 
 This fpecies differs from that of Bute, in containing lefs 
 magnefla, and being more durable. It frequently atfo con- 
 tains cubical cryftals of pyrites, and thefe long refift decom- 
 pofition. 
 
 GRAUWACKE, German IJland of Bell 
 RUBBLE STONE, Kirwan's Mineralogy^ 
 
 This fpecies is compofed of fragments of ardefia and quartz, 
 with fcales of mica, or talc, connected by a reddifh argilla- 
 ceous matter. This genus of rock was for fome time imagi- 
 ned to be peculiar to the Hartz (the great mining country be- 
 longing -to the Elector of Hanover), but later inveftigators 
 have obferved it in other parts of the continent of Europe. 
 We have much information concerning it in Lazius's obfer- 
 vations upon the Hartz. 
 
 LIME- 
 
MULL. 127 
 
 LIMESTONE Acbnacraig. 
 
 Colour. Dark blue. 
 
 Lujlre. A degree of luftre owing to difperfed foliae. , 
 
 Tranfparency. None. 
 
 Hardnefs. Difficultly fcraped with the knife. 
 
 Fratfure, Earthy ; fometimes approaching fplintery. 
 
 Has pyrites difperfed thro' it ; and fometimes I difcovered: 
 it to contain Bclemnites. By decompofition it acquires a yel- 
 lowifh colour, and this is much aided by the prefence of the 
 iron pyrites. 
 
 GREENSTONE \AcbnacroJb\ 
 
 Colour* Whitifh, from the great proportion of felfpar I 
 
 Lujlre. None. 
 
 Tranfparency. None. 
 
 Hardnefs. Gives fire pretty freely with fteel, 
 
 Erasure. Earthy. 
 
 Ef.a-; This 
 
liS M U L I.. 
 
 This rock appears to confifl principally of a whitifli -coloured 
 matter, which is probably of the nature of compact felfpar j 
 and, intermixed with it, I difcovered final! portions of a green- 
 coloured fubftance refembling hornblende, with a few inter- 
 fperfed cryflals of common felfpar and iron pyrites. It ac- 
 quires a browniih-white tegmen by decompofition. 
 
 GREENSTONE-/&7/ near Achnacralg. 
 GRUNSTEIN, German. SAXUM FERREUM, Waller. SAXUM 
 
 Linn. 
 
 The greenflone found upon this hill is compofed ufually of 
 equal portions of white-coloured felfpar and dark-green horn- 
 blende. I alfo obferved fpecirnens where the hornblende 
 forms the greater part of the ftone, and the felfpar im- 
 bedded in it as a bafis. In others, the felfpar and hornblende 
 are fo intimately combined together, that it is only by the 
 decomposition of the ftone that we difcover its compound 
 nature. 
 
 HORN- 
 
M U L T. 
 
 HORNSTONE Hill near Achnacralg. 
 
 Colour. Brown. 
 
 Ltiftre. None, 
 
 Tranfparency. Tranfmits a little light at the edges. 
 
 Frafture. Fine fplintery. 
 
 Hardnefs. Gives fparks freely with fleel. 
 
 By decompofition it takes a cream colour, and an earthy 
 fracture ; and, in this ftate, the diffufed particles of quartz are 
 rendered more diflinct, from their longer refitting the influ- 
 ence of the weather. 
 
 EARTHY FELSPAR. 
 
 CONTINUOUS FELSPAR, Angl. FELSPAR EN MASSE, Dolomieu, 
 PETROSILEX, Journ. de Phyf. New Series, vol i. La Mether. 
 Theorie de la Terre, 
 
 - 
 Colour. Brick red. 
 
 Lujlre. None. 
 Frafture. Earthy. 
 
 Trans- 
 
MULL, 
 
 Tranfparency. None. 
 
 Hardnefs. Give fparks freely with fteel. 
 
 Dolomieu, in a paper published in the Journal de Phy- 
 fique *, endeavours to prove that this foflil is diflindl from 
 felfpar, and, after a long chain of obfervation, he concludes 
 by naming it Petroiilex. La Metherie, who feems of the 
 fame opinion, denominates the true hornflone of the Ger- 
 mans Keratite, and agrees with Dolomieu in applying the term 
 Petroiilex to this foflil J. I am, however, fkill inclined to think, 
 that it will be more correct to ufe the terms hornflone and pe- 
 trofilex in the iigniiication as adopted by Werner ; and that the 
 petrofilex of Dolomieu is to be confidered as a fpecies of felfpar ; 
 or, if it be truly diftincT: from every other foflil, that it mould 
 be diflinguifhed by a name that has no reference to one already 
 in ufe. Dolomieu always refers it to the rocks of primary for- 
 mation ; yet this is not quite correct ; for Reufs f mentions a 
 fpecies of porphyry, with a bans of earthy felfpar, refting on 
 fandflone. 
 
 LIME- 
 
 * Vol. i. New Series, 
 
 J Theorie de la Terre, torn. ii. p. 173* 
 
 f Reufs, Aufz,atze, 388. Miner aloglfclie von Eoehmen, B. ii. 124. 
 
MULL. 231 
 
 LIMESTONE between Locb-na-gaul and Loch-Skrtddan< 
 
 Colour. Yellowifh. 
 Lnftre. None. 
 Tranfparency. None. 
 Fraffurc. Fine fplintery. 
 
 Hardnefs. Scarcely yields to the knife, and fometimes flrikes 
 fire with flint. 
 
 Contains, fometimes, cryflallized rhomboidal calcareous 
 fpar ; alfo difperfed particles of quartz ; which are frequently 
 fo plentifully intermixed, as to increafe the hardnefs very much. 
 But the moil remarkable intermixed fubftance is flint and 
 hornflone. 
 
 The flint has the following characters : 
 
 Colour. Greyifh black. 
 Lujlre. Like that of common flint. 
 
 Tranfparency. Tranfmits light pretty freely, but objects 
 cannot be difcerned, 
 
U 
 
 Fraflure. Conchoidal ; fometimes multiplied conchoi- 
 
 ckl. 
 Hardnefs. Gives fparks plentifully with Heel. 
 
 It lias immerfed in it particles of quartz fimilar to tliofe 
 we obferve in the limeftone ; and alfo intermixed is the horn- 
 itonc, which has the following characters i 
 
 Colour. Light blue. 
 
 Lnjlre. None. 
 
 Tranjfoarency. Allows light to pafs at the edges. 
 
 Fra&ttrc. Nearly even. 
 
 Hardnefs. Gives a few fparks with ftecl. 
 
 ' 
 It has alfo, interfperfed, calcareous fpar and quartz, By 
 
 action of the weather, it becomes opaque and white ; and the 
 quartz and calcareous fpar falling out, caufes the hornftone 
 to have a cellular appearance. Not unoften we obferve the 
 hornftone pafTing to flint, and vice ver/a. 
 
 Dr Walker, in his mineralogical lectures, informs us, that, 
 although he has travelled over a confiderable extent of Scot- 
 land, he has feldom obferved any appearance of flint. This 
 warrants us to conclude that it is a rare production in Scot- 
 
 land. 
 
MULL. 233 
 
 land. Similar limeftone rocks, containing flint, occur in the 
 north of Ireland, in Switzerland J, and my friend Mr Deria- 
 bin informs me that he obferved a rock refembling that of 
 Mull in Tranfylvania. 
 
 GRANITE/;* Rofs, in Mull 
 
 This granite, which forms the coaft of Rofs, in Mull, is 
 compofed of beautiful flefh-coloured felfpar, white quartz, 
 and black mica. Sometimes the granite is very fmall- 
 grained, with a great proportion of black mica, which 
 gives it a blackifh colour ; or we obferve it where the fel- 
 fpar is in the greateft proportion, when it has a fine uni- 
 form red colour. Rarely we obferve whitifh-coloured cry- 
 ftals of felfpar, and fteatites ; which laft, according to the 
 obfervations of Werner, is formed by the decompofition of 
 the mica. 
 
 G g BASALT 
 
 $ Helv. Mag. n6. 
 
234 MULL. 
 
 BASALT Torloiftt Luggan-Ulva, &c. 
 
 Colour. Black. 
 
 Luftre. Slight degree, from a number of very minute, min- 
 ing particles. 
 
 FraEture; Even, pamng to conchoidal. 
 Hardnefs. Gives a few fparks with fleel. 
 Streak. Grey. 
 
 The weather feems to have very little efFecl upon it, ex- 
 cepting when it contains iron pyrites. It frequently con- 
 tains zeolite, which is generally radiated ; and is fometimes 
 to be obferved pamng, by imperceptible gradations, to fine 
 milk-coloured chalcedony. As the late Mr Pelletier of Paris 
 has mown that zeolite contains potafh, and as it here pafles 
 to chalcedony, it is not improbable that fome fpecies of chal- 
 cedony may afford alkali. 
 
 WACKEN, 
 
MULL, 235 
 
 WACKEN, highly impregnated with Iron Tortoift. 
 
 Colour. Tile or copper red. 
 
 Isuftre and 'Tranfparency. None. 
 
 Frafture. Even. 
 
 Hardnefs* Yields with considerable difficulty to the 
 
 Is very heavy, and emits an earthy fmell when breathed. 
 upon. I obferved it palling into common wacken* 
 
 G g a ON 
 
O N COAL. 
 
 CHAP. XV, 
 
 Method of dif cover ing COAL. 
 
 JL\.FTER the defcripuon which I have given of the different 
 appearances of coal in the ifland of Mull, I intended to have 
 added a fhort account of the method to be followed in difco- 
 vering coal ftrata or veins ; but I found that this would be 
 more diftinct if detailed in a feparate chapter. I fhall now, 
 therefore, ftate the obfervations. 
 
 If a certain extent of country is fuppofed to contain coal, 
 we fhould begin our examination by determining the extent 
 of the primary ftrata ; which will confiderably abridge our la- 
 bour, as thefe ftrata never contain coal, 
 
 1 "We 
 
ON COAL. 237 
 
 We fhould next examine the nature, direction, dip, and rela- 
 tive extent of the different fecondary flrata ; which will give 
 us an opportunity of difcovering any appearances that indicate 
 the prefence of coal. Thefe particular places are to be exa- 
 mined with the mofl fcrupulous accuracy ; and the coal ftrata 
 to be fought for by digging, or boring, according to the na- 
 ture of circumftances. 
 
 Such is the general mode of proceeding in thefe refearches. 
 I mall now mention, particularly, the rocks which are indica- 
 tive of coal ; then the method of determining whether coal 
 flrata do exift in a certain fituation firft, as determined by 
 the appearance of fragments of coal, and, fecondly, by boring, 
 where no actual appearance of coal is difcovered. 
 
 The principal rocks, < which are mentioned by mineralogifts 
 as indicative of coal, are the following : 
 
 i. White argillaceous fandflone. If this fandilone has, in- 
 terfperfed, bituminous or carbonaceous matter, it is reckoned 
 a good fymptom of the vicinity of coal. 
 
 2. If 
 
238 ON COAL. 
 
 2. If bituminous male, fhiftofe clay and argillaceous iron- 
 ilone are obferved, it is a further, and a very favourable fymp>- 
 torn of coal. 
 
 3. If fandilone and limeftone alternate, and be accompanied 
 with bituminous male, it is reckoned favourable for coal. 
 
 4. Sometimes where fandflone and bafalt alternate, coal has 
 been found. 
 
 5. Mr Kirwan remarks that there is great probability of 
 finding coal in the neighbourhood of mountains of argillace- 
 ous porphyry f . 
 
 6. Although coal has never been obferved alternating with 
 primary ftrata, yet it has fometimes been found in their im- 
 mediate vicinity ; and coal has even been obferved lying on 
 granite. I believe, however, that fuch coal flrata are gene- 
 rally trifling. 
 
 Having 
 
 f Geological Eflays, p, 347. 
 
ON COAL, 239 
 
 Having, from an accurate inveftigation, difcovered fucli 
 ftrata as render the prefence of coal probable ; we mufl next 
 endeavour to difcover its actual exiflence. To do this, we 
 mufl examine the beds and banks of rivulets, where, if fmall 
 pieces of coal appear, we may be pretty certain that coal flrata 
 exift near at hand. Ditches are to be examined ; for, in form- 
 ing them, it is often necefTary to cut thro' the thin covering of 
 gravel and fand which conceals the crop from our view. We 
 fometimes obferve a footy-like matter fpread on the ground : 
 this is formed from the decompolition of coal, and is therefore 
 a good fymptom of its vicinity. Not unfrequently we obferve 
 mafTes of coal, or bituminous wood, immerfed in the breccia 
 which is obferved in coal countries : but this is often a falla- 
 cious appearance ; for, upon cutting thro' the breccia, we find 
 that the fubjacent rocks contain no coal ; fo that the pieces of 
 coal or wood, which the breccia contains, are to be confidered 
 as merely accidental. 
 
 After having obferved any of the above-mentioned appear- 
 ances ; our next endeavour is to obferve the crop, or the out- 
 burfl, of the ftrata. This is a matter of much difficulty ; and 
 requires particular attention to the difpofition of the fragments 
 of coal, &c. If they be found upon the banks or bed of a ri- 
 vulet, 
 
340 ON COAL* 
 
 vulet, we muft fearch from one extremity of the ravine to the 
 other, to difcover the crop of the ftratum. If the foot-like 
 matter is obferved, it will be necefTary to remark whether it 
 lies upon a declivity or a plain ; as inattention to thefe circum- 
 ilances has often been the caufe of great difappointment and 
 expence to the coal-miner in overfhooting the ftratum, that is, 
 cutting beyond its real fituation. Upon a declivity, we know 
 that the decomposing and loofe matter of a crop will naturally 
 fpread downwards, in proportion to the fleepnefs of the ground. 
 On this account, wherever appearances of coal occur upon a 
 declivity, we mufl trace the debris upwards ; when we mall 
 find it increafe in depth towards the crop, and the coal is lefs 
 and lefs decompofed as we approach nearer to it. On the 
 other hand, where the footy matter occurs upon a plain, we 
 always find it thicker, and far lefs fpread, than upon a decli- 
 vity ; and, what is of confequence, it often fpreads in a direc- 
 
 
 
 tion contrary to the rife of the ftrata. If we are fo lucky as to 
 obferve the crop, we now endeavour to detecl: the ftratum ; 
 which we do, either by digging towards its dip, or by follow- 
 ing the fragments of coal until we have the ftratum fairly 
 under our eye. 
 
 It 
 
ON COAL. 241 
 
 / 
 
 It often happens, however, that a country may be, in ge- 
 neral, very favourable for coal, yet no pieces of coal or footy 
 matter are to be obferved, owing to the coal flrata lying deep : 
 in fuch cafes a good deal of difcernment is necefTary to deter- 
 mine the particular places where the trials are to be made. As 
 it would be very expenfive, in fuch cafes, to dig down until 
 we mould meet with the coal, the common practice is to bore 
 the ground j by which, at a fmall expence, we can know the 
 magnitude and nature of the flrata, to a great depth. 
 
 In fearching for coal, by boring, our firft object is, to deter- 
 mine the point to which the flrata rife ; as it is this which en- 
 ables us to determine at what place we mall begin to bore. 
 The plan, at the end of this chapter, will fufficiently explain 
 the mode of proceeding in this operation. Suppofe A B C D 
 to reprefent a tract of country which is fufpected to contain 
 coal, and where the rife of the flrata is towards A. We there 
 make the firfl perforation, which will pafs thro' the flrata 
 4, 3, 2, i, to the depth of ten or twelve fathoms. If no coal 
 occurs among thefe flrata, it is better to make a new perfora- 
 tion, than to fink deeper. We therefore proceed onwards 
 to B, where we fufpedl that the flratum 5 is ten or twelve 
 fathoms deep. We here bore through the flrata, 8, 7, 6, to 5 ; 
 
 H h and, 
 
Q K O A L. 
 
 :md, as no coal occurs,, we do. not bore deeper, but proceed to 
 ;he point C, where we make a perforation through the ftrata 
 n, 10, 9, to 8. By being ftill unfuccefsful, we proceed on- 
 wards to D, where the ftratum 1 1 will be about ten or twelve 
 fathoms deep, and here we find coal at 12. By this practice,, 
 it is plain that that no ftratum of coal can efcape notice, as the 
 laft perforation always reaches down to the ftratum which was 
 neareft to the furface in the former bore. 
 
 Having difcovered the breadth of the flratum, either by dig- 
 ging, when it is near the furface, or by boring, when it is co- 
 vered by a great load of other ftrata ; our next concern is, to de- 
 termine whether it be of fufficient importance to be w r orked. 
 If it is not more than 15 inches in breadth, even altho' pretty 
 near the furface, it is not worth working ; but if it be two 
 feet, or two feet and a half wide, and of good quality, it can 
 he worked in moft fituations with advantage. . 
 
 * 
 
 The quality of the coal is afcertained from the following 
 
 circumftances : 
 
 i. Its general appearance : whether it be more or lefs mixed 
 with ftoney matter j or if there be laminae of bituminous fliale 
 
 or 
 
ON COAL* 
 
 243 
 
 ndftone, dividing it into ftratuta ; or i it contains much 
 pyrites or fulphuret of iron. 
 
 2. To theie may be added the teft of chemical analyfis, 
 by which we afcertain the proportion-of carbon, bitumena nd 
 aihes. 
 
 
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