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CONTENTS C 
 
 SCIENCES 
 UBRARY 
 
 OF THE FIRST VOLUME. 
 
 DOMAIN I. SIDEROUS. p. I 
 
 Mode I. Siderite 2 
 
 II. Basalt 17 
 
 III. Basaltin 32 
 
 IV. Basalton 72 
 
 V. Porphyry 75 
 
 VI. Porphyrin 87 
 
 VII. Porphyron 88 
 
 VIII. Porphyroid ib. 
 
 IX. Amygdalite ; 89 
 
 X. Iron-stone 95 
 
 XI. Jasper 99 
 
 XII. Slate 105 
 
 XIII. Mica Slate 122 
 
 XIV. Sideromagnesian Rocks 126 
 
 XV. Siderous Intrite 132 
 
 XVL Siderous Glutenite 135 
 
 DOMAIN II. SILICEOUS. 143 
 
 Mode I. Quartz 146 
 
 II. Keralite 153 
 
 III. Felspar 157 
 
 IV. Felsite 16O 
 
 V. Granite 177 
 
 VI. Granitin 201 
 
 VII. Graniton 202 
 
 VIII. Granitel , 203 
 
 IX. Granitoid,,, .,. 209 
 
 VOL. x. d 
 
CONTENTS. 
 
 ModeX. Granitic Porphyroid p. 210 
 
 XI. Gneiss 211 
 
 XII. Pitch-stone 218 
 
 XIII. Siliceous Intrite 22O 
 
 XIV. Siliceous Glutenite 223 
 
 DOMAIN III. ABGILLACEOUS. 239 
 
 Model. Alum Rock 242 
 
 II. Clay Slate 249 
 
 III. Clay Rock 269 
 
 IV. Wacken 273 
 
 V. Smectite 275 
 
 VI. Iconite . 278 
 
 VII. Argillaceous Intrite 281 
 
 VIII. Argillaceous Glutenite.. 283 
 
 DOMAIN IV. TALCOUS. 293 
 
 Mode I. Talc 301 
 
 II. Talcous Slate 309 
 
 III. Micarel Slate 312 
 
 IV. Steatite 313 
 
 V. Ollite 327 
 
 VI. Serpentine 334 
 
 VII. Saussurite 354 
 
 VIII. Green Granitel 362 
 
 IX. Magnesian Limestone 363 
 
 X. Green Marble 366 
 
 XI. Magnesian Intrite 372 
 
 XII. Magnesian Glutenite 373 
 
 DOMAIN V. CALCAREOUS. 376 
 
 Mode I. Marble 330 
 
 II. Konite 427 
 
 HI. Limestone 441 
 
 IV. Alabastrite ., 458 
 
CONTENTS. U 
 
 ModeV. Lime-slate p. 467 
 
 VI. Coral Rock >... 473 
 
 VII. Marlite 475 
 
 VIII. Orsten 480 
 
 IX. Gypsum 482 
 
 X. Alabaster 498 
 
 XI. Chalk 504 
 
 XII. Tufa 509 
 
 XIII. Calcareous Intrite 519 
 
 XIV. Calcareous Glutenite 520 
 
 DOMAIN VI. CARBONACEOUS. 54O 
 
 Mode I. Graphite 544 
 
 II. Anthracite 552 
 
 III. Coal 563 
 
 IV. Lignite 583 
 
CORRECTIONS AND ADDITIONS. 
 
 VOL. I. 
 
 P. 21, Note. Compare Ferrara's accounts in Dom. XII. 
 85, Note. Verd d'oeillet may be the peculiar light sea 
 green of the grass, or leaves, of some pinks or car- 
 nations. 
 
 98, 1. 13. For Eisenthorn, read Eisenthon. 
 106, 1. 21. The analysis of Slate and Mica Slate, by Dau- 
 buisson, is in the Journ, de Ph. Juin 1809. 
 
 Silex 48, 6 
 
 Argil 23, 5 
 
 Magnesia 1, 6 
 
 Peroxyd of Iron 11, 3 
 
 Oxy dated Manganese 5 
 
 Potash 4, 7 
 
 Carbon 0, 3 
 
 Sulphur 0, 1 
 
 Water and Volatiles 7, 6 
 
 Loss 
 
 100. 
 
 This he compares with Klaprotfc's analysis of Mica, 
 which yielded, Silex 47, Argil 20, Oxyd of Iron 15, 
 of Manganese 2, Potash 15. 
 
 137. Col. Imrie (Tr. Wern. Soc. i. 454), says, the glutenite 
 near Stonehaven consists of pebbles of quartz and 
 porphyry, with some of jasper, hornblende, horn- 
 stone, cemented by a reddish brown ferruginous 
 clay, mixed with minute particles of quartz and 
 mica, but which only fills the intervals. At Oban 
 
lit CORRECTIONS AND ADDITIONS. 
 
 the cement appears a blackish grey indurated sand, 
 composed of argil, fine sand, black oxyd of iron, 
 and is slightly coherent. It is singular that this 
 glutenite is vertical on the E. and horizontal on 
 theW. 
 
 P. 155, Note. The Slack Forest Mountains form another 
 example. 
 
 167, Note. For ava, read lava. 
 
 374, Note. For Voyage, read Journey. 
 
 345, 1. 8. For Marbois, read Marbore. 
 
 VOL. II. 
 
 64. Compare the sites of Miagite in the Appendix. 
 
 100, 1. 2. For resemble to, read resemble. 
 
 221, 1. 2. For Roy. read Roz. that is, the Journ. de Ph. 
 by Roziere. 
 
 267. The following account of the fall of Rosenberg may 
 not be unacceptable. 
 
 " On the 2d September, 1806, at five in the evening, the 
 Knippenouhl Rock, which formed the summit of Mount Ro- 
 senberg, was on a sudden detached from its situation j and at 
 the same time part of the mountain, of several feet thick, on 
 the western side, and about 280 feet thick on the east side, 
 gave way, and fell into the valley which separates the lake of 
 Zug from that of Lauwertz. One part of the mountain fell 
 into the lake of Lauwertz, which caused such an agitation in 
 the waters of the lake, that they overthrew a number of 
 houses, chapels, mills, &c. along the southern shore. Up- 
 wards of one thousand persons were the victims of this cala- 
 mity. A society of thirteen travellers were on the road from 
 Arth to Schwitz : nine, who walked first, perished ; the other 
 four escaped. In this convulsion enormous pieces of rock 
 were carried through the air to prodigious distances. The 
 lake of Lauwertz has lost above a quarter of its extent. That 
 rich plain which was so beautiful, now presents a mountain 
 of near one hundred feet in height, a league and a half in 
 
CORRECTIONS AND ADDITIONS. 
 
 length, and as much in breadth. The villages of Goldau 
 and Rothen, consisting of one hundred and fifteen houses ; 
 that of Busingen, of one hundred and twenty-six ; and that 
 of Kuslock, have totally disappeared. Of Lauwertz, which 
 lost twenty- five houses, there remain ten buildings, all much 
 damaged. Twenty years since general Pfyffer predicted this 
 catastrophe, from the knowledge that he had of the nature of 
 the mountain. A professor of Schwitz said, that above Spiets- 
 fleu was a sea of water, which had undermined the rock for 
 several years, and that below there was a cavern of great 
 depth, where the waters were engulphed. The quantity of 
 water which has fallen during the preceding years has hastened 
 this catastrophe, and the rains of some weeks past have de- 
 cided it. On the 10th eight hundred persons were employed 
 in digging for the bodies of those who were destroyed by the 
 falling of the mountain at Schwitz. In forming a channel to 
 draw off the waters, between thirty and forty labourers were 
 swallowed up by a torrent of muddy water, which broke in 
 upon them suddenly."* 
 
 Besides the plates and description published at Paris, there 
 are three large views drawn and engraved by Wiebel, a Swiss 
 artist, which the author has seen. The effect is not that of a 
 fallen cliff, as in granitic mountains, but that of masses of 
 rock, detached and thrown down a gentle declivity, with such 
 impetus as to overwhelm every obstacle, and spread to an 
 amazing distance. 
 
 P. 306, 1. 5. For tufa, read tufo. 
 
 401, 1.16. For PRODUCTION, read PRODUCTIONS. 
 428, Marginal indication. For Former rocks, read Forms 
 rocks. 
 
 * Annual Reg. 1806, p, 448. 
 
PETRALOGY. 
 
 A TREATISE ON ROCKS. 
 
 INTRODUCTION. 
 
 1. Illustrations of the present Arrangement. 
 
 THE study of natural history has been divided by the most Division of 
 
 natural 
 esteemed authors, and by the general voice, into three King- history, 
 
 doms, the Animal, Vegetable, and Mineral. These have 
 again been subdivided into Classes, Orders, Genera, Species, 
 and Varieties. These terms may be considered as strictly pro- 
 per with regard to animals and vegetables ; but as their com- 
 mon meaning implies a vital or animated principle, their 
 application to the mineral kingdom, to which they have 
 passed rather by habitual use than after a due examination, 
 has become dubious ; and has given rise to many variations 
 and contradictions, and not a little obscurity. It is confessed 
 that human systems have but a very remote connexion with 
 the great operations of Nature, and are to be regarded as 
 mere artificial memories : hence in mineralogy some eminent Some terms 
 writers entirely reject Genera ; while others, with Dauben- 
 ton, say that there are no Species -, and Dolomieu has in vain 
 exhausted his acuteness and science to prove that real Species 
 exist in this department. With all his metaphysical prolixity 
 he has no disciples in this doctrine ; and the idea of a Species 
 remains dark, even to the most enlightened minds, because 
 it is false and unnatural, as in the other branches of natural 
 history a Species produces a similar progeny. 
 VOL. i. a 
 
INTRODUCTION. 
 
 Other Thus some writers have been contented to divide minerals 
 
 objections. .^ a^g^ Orders, and Genera -, while others, instead of 
 the last, have only Species. Some have Varieties ; and Wer- 
 ner, with a truly German want of taste, has added Sub-species 
 and Sub- varieties ; while, as the terms are merely arbitrary, 
 he might have chosen far mose classical words to express his 
 distinctions. 
 
 The cause of this embarrassment, as has often happened in 
 the progress of science, is owing to the pursuit -of a routine, 
 of a form, which has become antiquated ; while the dis- 
 coveries being wholly new, a new phraseology was indispen- 
 sable. Thus in natural history Linnseus having established 
 the received classification in botany and zoology, the same 
 terms were introduced into mineralogy, without the simple 
 reflection that the subjects were wholly distinct: for the 
 terms, indicating animal and vegetable life, could not without 
 manifest absurdity be applied to dead and inert matter. The 
 consequence was, that as the terms conveyed no idea, they 
 were used indifferently, and what was Class with one author 
 became Order with another j while the Genus of a third, as 
 has been already mentioned, became the Species of a fourth : 
 and a few of deeper sagacity began at last to doubt the pro- 
 priety of one or other of these appellations. 
 
 In fact the terms class, order, genus, and species, convey 
 real and vivid ideas of life. We say a class or an order of 
 men, a genus or species of animals, with complete perspicuity 
 and propriety. N6r is the transition to plants in the least 
 violent, as the word species in particular may be here used 
 with some classical authority. But when applied to minerals 
 they become wholly arbitrary, and convey none of these sub- 
 stantial ideas which belong to real knowledge, and which the 
 mind grasps, so to speak, as solid and tangible : for as the 
 characteristics are here of a totally different kind from those 
 of animal or vegetable life, they should be distinguished by 
 new and appropriate appellations. As we shall never describe 
 an animal from its texture, fracture, or other distinctions of 
 minerals, so it is equally absurd to describe these by attri- 
 
INTRODUCTION. 
 
 ill 
 
 butes which are peculiar to living substances. The terms 
 become wholly useless if they do not serve to distinguish and 
 discriminate ; and numerals, chemical marks, or any other 
 arbitrary symbols, would serve the purpose equally well. 
 
 The impropriety of the present phraseology is often ad- 
 mitted, while it is considered as bold and adventurous to 
 hazard a new series of appellations j but in literature, as in 
 war, he who shrinks from the path of danger will never attain 
 the wreath of praise. 
 
 In an attempt to establish a new nomenclature of arrange- New system, 
 ment, the first requisite is, that it be conformable to the 
 simplicity and harmony of nature ; and that it be free from 
 affectation, as even the novelty itself is apt to displease. For 
 this purpose it is necessary to revert to first principles, and 
 if possible to establish the edifice upon foundations univer- 
 sally admitted. Natural history, as already mentioned, has 
 been well and popularly divided into three Kingdoms, the 
 Animal, the Vegetable, and the Mineral. In the two former 
 the kingdom consists of living subjects, who of course may 
 be well considered as divided into Classes, Orders, Genera, 
 and Species ; but in the Mineral Kingdom the territory alone 
 constitutes the subject of discussion. It must therefore be 
 received as a fundamental truth or axiom, that the mineral 
 kingdom, being wholly inert, cannot admit distinctions which 
 belong to vital energy 5 and that an identity of appellations 
 cannot therefore be allowed, either in a grammatical or 
 philosophical view. But the very term Mineral Kingdom 
 may of itself lead to a new and more proper nomenclature : 
 for as a kingdom may be regarded as either vivified with 
 animal and vegetable life, or as an inert tract of country, 
 with certain geographical, chorographical, and topographical 
 divisions ; so the latter point of view can alone apply to mi- 
 neralogy, while the former belongs to zoology and botany. 
 
 This simple induction will, it is hoped, lead of itself to easy 
 and natural, though new denominations. For what is more 
 usual than the division of a kingdom into provinces, districts, 
 domains, &c. ? while, as it would not only be pedantic, but 
 
 a 2 
 
IV 
 
 Grand 
 provinces 
 
 INTRODUCTION. 
 
 inadequate to the subject, to carry this species of metaphor 
 too far, some lesser divisions must be borrowed from the 
 nature of the objects, as they present themselves to the 
 
 observer. 
 
 I would propose, therefore, in the present advanced state 
 of the science, that the mineral kingdom be considered as 
 divided into three provinces : 1. PETRALOGY, or the know- 
 ledge of rocks, or stones which occur in large masses. 
 
 2. LITHOLOOY, the knowledge of gems and small stones. 
 
 3. METALLO&Y, or the knowledge of metals. Each of these 
 branches is even at present so important, and offers such 
 numerous topics of disquisition and research, that in the 
 course of no long period a professor of each will appear in 
 universities ; and each might occupy the sole pursuit of an 
 author who is zealous to make discoveries, or to compose 
 complete and classical works. One of the chief causes of the 
 slow progress of the science is, that it is too wide for one 
 mind j and as zoology has been divided into ornithology, 
 ichthyology, entomology, &c. so mineralogy, to be duly stu- 
 died, should have grand subdivisions. 
 
 These provinces may again be viewed as divided into DO- 
 MAINS, corresponding with the Orders of some writers and 
 the Genera of others, as the Provinces supply what was called 
 Classes. This term DOMAIN is preferred to District, &c. as 
 it not only implies a subdivision of a province, but, in another 
 acceptation, a ruling or preponderating power, strictly appli- 
 cable in mineralogy, where it is often the preponderance, 
 and not the universality, which imparts the denomination. 
 Thus in the siliceous, calcareous, and other domains, it is only 
 understood that the denominating portion preponderates, 
 as few or no rocks are pure, and unmixed with other sub- 
 stances. 
 
 Petralogy, a province of mineralogy, may therefore be re- 
 garded as divided into Twelve Domains j of which the first 
 six, being distinguished by the substances themselves, may 
 Substantial, be called SUBSTANTIAL : while the remaining six, being distin- 
 guished by circumstances or accidences of various kinds, may 
 
 Domains. 
 
INTRODUCTION. 
 
 be called CIRCUMSTANTIAL, or ACCIDENTIAL j but this last 
 division is of little moment. 
 
 The first six domains of Petralogy comprise, 1. The Si- 
 derous Rocks, or those in which iron predominates, not in 
 the comparative quantity when analysed, but in the quality 
 and essential difference which it imparts. 2. The Siliceous, 
 denominated as usual from the quantity of silex. 3. The 
 Argillaceous. 4. The Magnesian : these two are ;again de- 
 nominated from predominance. 5. The Calcareous. 6. The 
 Carbonaceous. 
 
 The remaining six domains, derived from circumstances or Accidential. 
 accidences, are, 7- The Composite, or Aggregated Rocks, as 
 calcareous spar with schorl, quartz and garnets, felspar and 
 siderite or hornblende, &c. This domain has often been con- 
 founded with the granites, however alien from that descrip- 
 tion. 8. The Diamictonic, or rocks in which the substances 
 are so completely mingled, that it is difficult, even upon an 
 analysis, to pronounce which preponderates. 9. The Ano- 
 malous, or those which contradict the common order of 
 nature, and present unexpected and unusual combinations. 
 Some of these domains, though they afford few objects at 
 present, may, in the progress of the science, be greatly 
 enriched and enlarged ; and the utility of such divisions will 
 be more perceptible as the study advances towards perfection, 
 the greatest obscurity at present arising from the want of 
 necessary subdivisions. 
 
 The remaining three domains are generally admitted in 
 geological works, namely, 10. The Transilient Rocks, an 
 interesting series, in which one substance gradually passes 
 into another, as granite into porphyry, trap into wacken, 
 and the like. 11. The Decomposed Rocks, which gradually 
 decay into sand, clay, or productive soil. 12. The Volcanic, 
 which require no other description. 
 
 Having thus established the Domains, or Great Divisions, Modes t 
 of Petralogy, the smaller distinctions can be derived only 
 from the objects themselves, as we now arrive at what are 
 by most mineralogic authors denominated Species, though in 
 
INTRODUCTION. 
 
 their arbitrary and unnatural systems, as Dr. Townson has 
 observed, the Genera and Species are often confounded. 
 " Thus in the improved edition of Linnaeus, the characters 
 which constitute the Species in gypsum form Genera in the 
 carbonate of lime ; for the pulverulent, fibrous, spathous, 
 and compact kinds of gypsum form but so many Species, 
 whilst the pulverulent, fibrous, spathous, and compact kinds 
 of carbonate of lime form so many different Genera." 
 Now these very appearances, which constitute the arbitrary 
 Species and Genera of former authors, what would they be, 
 in the eyes of a philosopher or grammarian, except different 
 modifications, or modalities, of the same substance, and which 
 by a shorter term may be denominated Modes ? Hence the 
 term MODE, which is universally applicable and unobjection- 
 able, to distinguish such objects in mineralogy, is here ad- 
 mitted instead of Species f. 
 
 To put the propriety of this new appellation to the test, 
 examples may be produced of what are called Species by the 
 most celebrated mineralogic writers. Wallerius, among the 
 species of garnet, first mentions that of an undetermined 
 figure, composed of granular particles j and his next species 
 is of an undetermined figure, but laminar. What are these 
 but different modifications, or modes, of the same stone? 
 His ripe asbestns, consisting of fibres which may be sepa- 
 rated, forms one species ; while that of which the fibres can- 
 not be separated constitutes another. What are these but 
 different modifications of the same substance ? In the last 
 edition of Linnaeus by Gmelin, the term modes (modi) has 
 been applied to various appearances of petrification : but 
 what are sometimes called Genera, and sometimes Species (as 
 already observed from Dr. Townson), are, in strict language, 
 mere modifications of matter. If we pass to one of the most 
 exact of the French mineralogists, we shall find the sapphire 
 arranged as the tenth species of the siliceous, and the topaz 
 
 * Philosophy of Mineralogy, p. 173. 
 t E<8of implies modus, as well as species. 
 
INTRODUCTION. Vll 
 
 as the eleventh ; while in fact they merely differ in colour. 
 In the magnesian division, what are bole, fullers' earth, &c. 
 but different modifications of the same mixtures ? Mr. Kir- 
 wan presents no exact arrangement, but uses Classes, Fami- 
 lies, and Branches, in such a manner as greatly to perplex the 
 reader : but all his species and families are mere modifications, 
 and the simple division into modes would convey a far 
 clearer idea*. 
 
 The term Mode is therefore here adopted instead of what 
 are called Genera by some writers, and Species by others ; this 
 uncertainty, of itself, having demonstrated that there are 
 neither Genera nor Species in mineralogy. 
 
 But as it is now universally allowed by all mineralogists, Chemical, 
 however different their systems, that the whole science rests 
 upon chemistry alone, and that no certainty can be found ex- 
 cept by chemical analysis, the word Mode, as finally admitted 
 into the present system, must be chiefly understood to refer 
 to the CHEMICAL MODE OF COMBINATION, upon which the 
 nature of the substances, as is now allowed by the greatest 
 chemists, is yet more dependent, than even upon the ingre- 
 dients combined. It is the MODE OF COMBINATION which 
 distinguishes a diamond from carbon, and a sapphire from 
 argil combined with a little iron : the essence of a mineral 
 consisting not only in the constituent earths, but in the pe- 
 "iliar way in which the mixture is modified ; and this modal 
 influence also prevails in many artificial mixtures and com- 
 pounds f. In short, the pretended species of former authors 
 are merely different MODES OF COMBINATION. 
 
 * Dr. Thomson, in his valuable Chemistry, has preferred the families of 
 Werner, and discarded the old genera; iv. 247. Mr. Jameson tells us that 
 there is in fact only ONE species in mineralogy, namely the globe ; but even this 
 may be doubted till it shall have produced another at least, as round and as 
 wicked. 
 
 j* Tliis may be exemplified from the Arragon spar, in which the ingre- 
 dients are the same as in calcareous spar, yet it differs in many properties, not 
 from composition but from modification, the gangart of red clay or gypsum pro- 
 bably imparting a tincture of iron. 
 
viii 
 
 INTRODUCTION. 
 
 Structures. This, the most important part of the arrangement, being 
 thus borrowed from chemistry, which like a guardian angel 
 should always hover round and direct the labours of mine- 
 ralogy ; the other subdivisions only require a characteristic 
 clearness to assist the memory (the chief object in any system 
 of natural history), and an appropriation to the subject, so 
 as to satisfy the judgement and imagination. From the 
 earliest productions of Linnaeus to the present time, the 
 word STRUCTURE has been applied, with classical propriety, 
 to denote a most striking and characteristic distinction be- 
 tween mineral substances, whether on a great or on a small 
 scale. Linnaeus has observed that there are only three great 
 roads which can conduct the curious traveller through the 
 mineral kingdom ; that of Physics, or Natural Philosophy, 
 which treats of the obscure generation of stones ; that of 
 Natural History, which examines their evident structures ; 
 and that of Chemistry, which considers their analyses *. A 
 term thus strictly appropriated, and, as it were, consecrated 
 to the science, has therefore been selected for the next char 
 racteristic subdivision. 
 
 But as Werner and his disciples not only admit the various 
 earths, as so many Genera ; and their Modes, or the modifi- 
 cations of the mixtures, and even colours, as so many Spe- 
 cies , but also what are, with great penury and uncputhness 
 
 Aspects. 
 
 
 * <{ Via triplex tantum per Regnum Lapideum curiosos ducit : Physica qua 
 descendit per Lapidum obscuras Geneses. Naturalis quae excurrit per Lapidum 
 apricas Structures. Chemica quae adscendit per Lapidum destructivas Analyses ." 
 Linn. Min. aGmelin, p. 14. 
 
 In the* edition of his System, Holmise 1768, Linnaeus has the following 
 among the external characters : " The Structure, foliated, fissile, convergent, 
 in fragments." Werner says limestone is of a simple structure. Dr. Thomson, 
 in his valuable Chemistry, says that gneiss differs in its structure from granite ; 
 and that the structure of mica slate is thinly schistose. It is chiefly judged by 
 the fraeture; and is as applicable to small specimens, if well chosen, as to the 
 rocks themselves : it may be earthy, compact, columnar, large-grained, &c. &c. 
 In .classical Latin structura is not only applied to the largest edifices, but in very 
 minute senes ; as structura versuum, structura yerlorum. 
 
INTRODUCTION. IX 
 
 \ 
 
 of language, styled Sub-species, with still smaller divisions of 
 Varieties, and Sub-varieties; so there remains a necessity for 
 more minute discriminations in this new arrangement. In 
 his excellent and elaborate system of chemistry Dr. Thomson 
 seems to have hit upon the just and natural term, when he 
 uses the word ASPECT as a chief characteristic. " The parti- 
 cular characters, says he, are the following: 1. Aspect of 
 the surface 5 C Z. Aspect of the fracture ; 3. Aspect of the 
 distinct concretions - } 4. General aspect, &c." As therefore 
 the most important object in the study of minerals is to 
 distinguish them by their external characters, and especially 
 by those apparent to the eye, the aspect becomes of such 
 radical importance that it may with the greatest propriety 
 be admitted into the distinctive nomenclature. The verb 
 aspecto signifies to view with great attention or earnestness, 
 and affords a hint to the student that these subdivisions called 
 aspects require strict attention and discrimination. Thus, 
 while the Mode chiefly expresses the difference of chemical 
 composition, &c. and the Structure the grand characteristic, 
 the Aspect refers to more minute features. The term variety Varieties, &c, 
 is unobjectionable, as it is equally applicable to objects of ani- 
 mated orhiert matter j and diversity may be used to imply a 
 still greater difference than the variety presents. A very 
 faint shade of difference might, if necessary, be called a 
 lineament. 
 
 Having thus briefly explained the present system, the 
 result of the reflections and meditations of many years (for 
 it is well known that simplicity in a plan, or a machine, as 
 it is the most perfect quality, so it is the last which is dis- 
 covered), it may not be unnecessary to illustrate its necessity 
 and utility by some further observations. 
 
 The embarrassments of the former systems cannot be more 
 forcibly evinced than by the following discussion by Wer- 
 ner, in his important work on the External Characters of 
 Minerals. 
 
 " I shall here add some remarks upon the division or natu- Werner's 
 ral order of bo'dies in general, as wejl for example, as expja- difficulties. 
 
INTRODUCTION. 
 
 nation of this paragraph. When we wish to arrange a 
 system j or, which is the same thing, when we wish to deter- 
 mine the natural order of bodies ; we must first find a princi- 
 ple on which to ground that determination. But this prin- 
 ciple should be taken from the nature of the bodies, as being 
 the consequence of it j and since it is by that we determine 
 in what degree these bodies are similar or unlike, it should 
 show equally the principle of their difference. We perceive 
 in these bodies certain resemblances which are the foundation 
 of their differences, and as these several resemblances are 
 more or less allied or varied, so it is with the bodies which 
 produce them ; this then is the only principle on which we 
 can determine the class or order of these natural bodies. It 
 remains now to show where relations are found in natural 
 bodies 5 but here we find a difference between them, for they 
 are divided into two principal species, these relations in one 
 consisting in the conformation, and those of the other in the 
 composition; the first comprising animals and vegetables, 
 as the second embraces meteors and the mineral kingdom. 
 It is true that, as being natural bodies, they are at the same 
 time aggregated and composed j but the first are formed of 
 parts differing one from another, and which we cMl organs, 
 which constitute their relations ; the last, on the contrary, 
 are simple, or formed of similar parts, and consequently can 
 have no relationship in their aggregation. Now, as they 
 nevertheless really differ, that is to say, they have different 
 characters, we must endeavour to recover them in some man- 
 ner ; and, as I have already said, this can be only by their 
 composition. As a proof of which, when I have divided into 
 as small parts as possible, a substance of one of the first two 
 kingdoms, for example a plant, I cannot affirm that each 
 separate part is the same plant 5 because not any of these 
 parts have the same relationship as in their state of aggrega- 
 tion, that is to say, in their entire plant, and that it is this 
 total which forms this or that plant. It is then in this re- 
 union that we must show the character of this plant, since it 
 is destroyed by the division. On the contrary, I can divide 
 
INTRODUCTION. XI 
 
 any mineral whatever as I will ; the smallest particle that can 
 be obtained by mechanical instruments, will always be the 
 same mineral ; for each particle, be it ever so small, preserves 
 the same properties as would the whole in their collective 
 state. These qualities consequently are not confined to the 
 aggregate, since they do not cease with it. But if I destroy 
 the composition of a mineral, that is to say, if I reduce it to 
 its constituent parts, then each separate constituent part is 
 no longer the same mineral, because it has not the same pro- 
 perties as when in composition. When, for example, I de- 
 compose the glassy silver ore fglaserz sproede) in separating 
 the silver, the sulphur, and the arsenic -, or cinabar, in with- 
 drawing separately the mercury and the sulphur ; I cannot 
 then say of these constituent parts, that they are still the 
 mineral in the composition of which they formerly existed. 
 Thus there is no doubt that the relations of minerals consist 
 in their composition, since they cease with it. 
 
 " In the second place, the gradation of natural bodies into 
 one another (which is the most infallible sign of the natural 
 order), shows us that the different relations of the bodies of 
 the two former kingdoms consist in their aggregated state, by 
 means of which they pass as it were the one into the other ; 
 as likewise that the relations of bodies of the two latter 
 kingdoms, that is to say, minerals and meteors, are in their 
 composition, because it is only by reason of this composition 
 that they pass the one into the other : as, for example, in the 
 mineral kingdom, the glassy silver ore passes to another kind 
 (the brittle) j this to the red silver ore (Rothgultig) ; and 
 this again to the white silver ore (Weissgultige) ; according 
 as to the first is joined arsenic, to the second raw iron, and 
 to the third copper. In fine, we have a sufficient number of 
 examples of passages of the animal kingdom into the vegeta- 
 ble, and of the mineral kingdom into that of meteors j 
 whereas, with regard to the passage of the animal and ve- 
 getable kingdoms into the mineral, we have no proof: and 
 indeed, as we have before observed, that can never be, be- 
 cause in the first the natural order of relations follows their 
 
INTRODUCTION. 
 
 aggregation, while in the latter it follows their compo- 
 sition. 
 
 " But the following question may still be raised concern- 
 ing the order and system of minerals : ' As it is certain that 
 minerals, when their composition changes, are also changed 
 in their exterior, cannot we in this exterior find characters 
 to determine their natural order or sequence, as well as those 
 that are taken from their affinities of composition ?' Here 
 is the answer : We can, it is true, discover the different rela- 
 tions of composition in minerals by their different external 
 characters, when they are both determined beforehand j but 
 we cannot discover the order of these conformities, because 
 nature employs indifferently sometimes one character, some- 
 times another, to indicate the interior difference, that is to 
 say, the composition ; in the second place, because each ex-* 
 terior character sometimes arises from an essential difference, 
 at other times only from an accidental variety. The systems 
 of those who have inclined to arrange minerals by their 
 external characters, may already furnish proof of the incon- 
 veniences of this method, because we there see mineral 
 brought together which are essentially different -, and that 
 those of the same kind are separated by reason of some acci- 
 dental variety. Botanists and Zoologists have this advantage, 
 that in the objects of those sciences they find the conformities 
 of bodies by their exterior -, and that while they endeavour 
 to class them according to the aggregation of their external 
 parts (or organs), they describe also their external characters, 
 and in some measure accomplish these two objects at the 
 same time. The labour of mineralogists is quite different - 3 
 they must determine at once the composition of minerals by 
 their appearances under chemical operations, or otherwise 
 leave it to be determined by the chemists, and consequently 
 class them accordingly. They ought, on the other hand, to 
 seek after their exterior characters, in order to complete the 
 description from them. 
 
 " I shall also remark, in the first place, that mineralogists 
 hitherto seem to me to have been too much attached to the 
 
INTRODUCTION. Xlll 
 
 retention, in their systems, of the four gradual divisions of 
 the logicians, into classes, orders, genera, and species ; and 
 that, to a certain degree, they thereby do violence to nature. 
 I, nevertheless, believe that in this respect we may determine 
 something certain ; that is to say, how many degrees there 
 are in the division of minerals according to their constituent 
 parts : but as this is not the place to enlarge on this subject, 
 I shall reserve it for another occasion, since, in regard to the 
 subdivisions, it is always well to preserve those once intro- 
 duced. 
 
 f( I shall observe, in the second place, that mineralogists 
 are little agreed, and are even undecided, with regard to 
 what they call the species : if we would take this word in a 
 determined sense, in general, all minerals that essentially 
 differ from one another in the relations of their composition 
 form different species ; and all those that essentially assimilate 
 in these relations, should be considered as forming one sole 
 species. Moreover, all the separate pieces of one species are 
 individuals*, to which we substitute the word species, because 
 it is impossible to have at the same time the entire species 
 which comprises all the mineral individuals which may be 
 found buried under the earth, or upon its surface. In short, 
 all the minerals by which one species passes into another, 
 atid which accidentally differ in one or other of its charac- 
 ters, are varieties."-^ 
 
 The division into Genus and Species seems, as Werner here Species of 
 justly observes, to have been first conceived by the writers logicians. 
 
 * This word is a further proof of the absurdity of the classification ; for a 
 plant or an animal may be an individual, but a mineral may always be divided 
 ad infinitum. 
 
 f Werner, Traite* des Caracteres Exterieurs des Fossiles, trad, de Madame 
 Picardet, Paris, 1790, 8vo. p. 918. 
 
 The German terms used by Werner (see Principes de Mineralogie, par 
 Berthout et Struve, Paris an 3,) are Geschkchter for Genus ; Gattungen for 
 Species ; Arten for Sub-species. The first (see Schwan) means germs, species, 
 race, nay genders, nation. The second, sort, manner, species of animals. 
 The third, sort, species, race, nature, complexion, air, manner, custom, 
 fashion. 
 
INTRODUCTION. 
 
 on rhetoric and logic. The great Milton, in his Latin 
 treatise on logic*, has discussed this subject, chiefly on the 
 authority of Aristotle and Cicero: his examples are only 
 accidentally from living beings ; and he even appears embar- 
 rassed to distinguish between the species and individuals ; for 
 he argues that, as form is admitted by Aristotle as a discri- 
 mination of the species, and every man differs in form from 
 another, so every man must form a distinct species. He 
 adds, that the lawyers allow man to be a genus, while indi- 
 viduals constitute the species j but he observes, that Ovid 
 divides the genus ANIMAL into Jive species: Stars, Birds, Beasts, 
 Fishes, and Men. So Cicero divides virtue into four species : 
 Prudence, Justice, Fortitude, and Temperance. The pe- 
 dantry of this great poet is truly pisible 3 but thus it was 
 when logic was the art of talking nonsense according to a 
 fixed method. Yet it is from logic, as Werner and the other 
 German mineralogists allow, that the imaginary distinctions 
 of genus and species were admitted into mineralogy ! 
 
 Dolomieu being sensible that the whole process depended 
 upon ascertaining the species, which if once admitted, the 
 genera, &c. would follow of course, has employed much 
 metaphysical reasoning in his usual prolix, confused, and 
 digressive style, to ascertain an imaginary species in mine- 
 ralogy. He ought to have begun by informing his readers, 
 that he was only discussing the word species, as used in 
 modern natural history, where, in that of animated nature, it 
 has become a useful distinction. But the ancient and clas- 
 sical senses may be learned from the commonest dictionariesf. 
 
 * London, 1672, I2mo. cap. 27. 
 
 f As for example that of Ainsworsh. " SPECIES, d. f. (a SPECIO.) (l.) A 
 form, figure, fashion, or shape. (2.) A sight, or object presented to the sight. 
 (3.) A likeness, or representation. (4.) An outward show, or appearance. 
 (5.) Colour or pretence. (6.) A vision or sight, a spectre. (7.) An image, 
 picture, or statue. (8.) An example, a specimen or instance. (9.) The quality 
 or nature of a thing. (10.) Also a particular sort, a kind of things under a 
 general head. (11.) Sight or view, (l 2.) All kinds of spice, a drug. (13.) 
 Corn or fruit. (14.) A piece of money. (15.) A garment, or apparel. (16.) 
 
INTRODUCTION, XV 
 
 It is indeed not a little remarkable that, among the nume- Classical 
 rous senses in which the word species is used by the Roman 
 classics, there is little appearance of its modern sense in natural 
 history. Nay, even in the modern languages, all its deriva- 
 tions and collaterals may be equally said to be foreign to that 
 acceptation ; as for example in the English, special, specially, 
 specialty, specific, specifically, specificate, specification, specify, 
 specimen, specious, speciously. It therefore chiefly belongs, with 
 the greater part of the Linnean language, to a modern latinity 
 so barbarous, as even to confound genders and cases, and 
 many others of the commonest rules of grammar. 
 
 But to return to its use in modern mineralogy. In his 
 able criticism on Haiiy's Tableau Comparatif, the last fruit of 
 the researches of that eminent crystallogist, Lametherie has 
 shown that the supposed species can be ascertained by no means 
 but that of chemical analysis j and that the doctrine of the 
 integrant molecule has been abandoned by Haiiy himself*. 
 
 Any sort of meat. (17.) A controversy. (l.) Species et figura humana, Cic. 
 pro T. Rose. 22. Specie lepidS. mulier, Plant. Rud. 2, 4, 2. Proraissa barha 
 et capilli efferaverant specietn oris, Liv. 2, 23. (2.) Non tulit hanc speciem 
 furiata mente Choroebus, Virg. En. 2, 407. (3.) Speciem ac formam similem 
 gent ejus imago, Liter. 4, 49. (4.) Moveri falsa visione, et specie doloris, 
 Cic. Tuse. 2, 18. Praeter speciem alienae fungendae vicis suas opes firmavit, 
 Liv. (5.) } Seeuritas specie Llanda, reipsa repudianda, Cic. de Amic. 13. 
 (6.) Non prius hostem destitit insequi, quam species barbaree mulieris human! 
 amplior, victorem tendere ultra sermone Latino prohibuisset, Suet. Claud. 1. 
 Sibi quoque eandem speciem aliquot jam noctibus observari retulit, Id. ib. 37. 
 Species Homeri, Lucr. 1, 125. (7.) Ex sere species vetus, ap. Cic. Div. 1, 
 12. Est aurigae species Vertumnus, Prop. 4, 2, 35. (8.) Hanc speciem 
 Hbertatis esse, si omnibus, quod quisque vellet, legibus experiri liceret, Nep. 
 Timol. sub Jin. (9.) Liv. 35, 49. ( 10.) X Cum genere idem sit, fit aliud, quod 
 quadam parte et specie differat, Cic. de Inv. 1, 27. K In universum, Tac. 
 Germ. 5. (11.) Luna potest majus lumen convert ere nobis ad speciem, 
 Luc. 5, 704. (12.) Curabis ut specierum vis omne corpus inficiat, Pall. Octal- 
 tit. 14. (13.) Arcad. (14.) Litt. ex Macr. (15.) Capit. (16.) Lampr. 
 
 * L'analyse ne proure que le fer chromate est une espece, que parce qu'elle 
 y trouve constamment les me'mes principes. Done il n'y a que 1'analyse qui 
 determine les especes. Done toute substance, cristallise'e ou non, dont 1'analyse 
 
INTRODUCTION. 
 
 As It is therefore granted on all hands, that chemistry alone 
 can decide what is called the species, and that it depends chiefly 
 on the MODE OF COMBINATION, is it not more logical and 
 philosophical to adopt the only term which can express its 
 real nature ? 
 
 It is clear that Haiiy has abandoned his doctrine of species, 
 in which he had followed Dolomieu, who assumed the mole- 
 cule integrante of Delisle as the basis of a species*. Dolomieu 
 closes his elaborate essay on the subject with the following 
 strange definition of a species, in fact a mere ens rationis in 
 mineralogy. 
 
 " The mineralogic species is a being distinct from all 
 others by a particular constitution, and which receives from 
 that constitution every thing which should characterise it. 
 This being exists in the integrant molecule, is physically re- 
 presented by the homogenous masses which have been sub- 
 mitted to the laws of regular aggregation, and it holds under 
 its dependence all the beings which have a similar constitu- 
 tion, even when faults of conformation set them at a distance 
 from the physical representation of the species, or when 
 superfluities and contaminations make it wear a foreign 
 livery." A very curious and original specimen of a defini- 
 tion ! 
 
 Though Werner repeatedly allows that all mineralogical 
 arrangements must depend upon chemistry, as they can only 
 be formed on the quality and quantity, and mode of combi- 
 nation, of the constituent parts ; yet, with a not illaudable 
 predilection in favour of natural characters, he uses them 
 chiefly to decide the species; while the species is in fact 
 the most important and the most dependent upon chemical 
 
 retire constamment les mmes principes, est une espece. II n'est pas necessaire 
 de savoir si elle a uoe molecule. Mais 1'analyse seule est insuffisante, il faut 
 encore avoir egard aux caracteres exterieurs, et aux proprie'te's physiques ; comme 
 pour le spatte calcaire et I'arragonite, le ruthil et 1'oisanite. Journ. de Ph. 
 Juillet, 1809. 
 
 * See Tableau, p. ii. " J'ai prefers* V indication de la forme primitive a celle 
 de la molecule integranle," &c. 
 
 

 , ... 
 
 INTRODUCTION". XVU 
 
 <' 
 
 aid*. Hence have arisen the chief errors in his system, ably 
 exposed by Chenevix, who has shown that the different 
 species of Werner are often vague and indeterminate ; and 
 the order of his arrangement not seldom capricious and 
 imaginary, and far from being founded on his own principle 
 of chemical composition. The calcareous spars are united 
 under several groups, according to the acid which predomi- 
 nates. Those he has marked A, B, C, D, are truly German, 
 distinctions. Dr. Thomson has justly observed, that by his 
 use of groups and families, Werner is struggling against his 
 own system. 
 
 But the mode admitted in the place of the species, obviates 
 these difficulties. It presents a real chief distinction between 
 the species, that founded on chemical analysis, as it refers to 
 the mode of combination, the ruling principle in the difference 
 between one mineral and another, considered even in the 
 most abstracted point of view, and with regard to the purest 
 substances, as crystals, gems, &c. ; as even a variation in the 
 water of crystallisation sometimes distinguishes one mode 
 from another. But though what are admitted as distinct 
 modes, will perhaps always be found to differ in chemical 
 analysis j yet as the science does not admit of too much pre- 
 cision, while the substances themselves are always variable, 
 as partaking of a mutual nature, and only portions of that 
 vast mixture the shell of the globe j the mode may also more 
 laxly be understood to include some modifications of external 
 characters, under what is called aggregation in particular. 
 Thus the aggregated stones may become modes, as well as 
 the combined. But in passing to the Structure and Aspect, 
 the chemical characteristics may in general be considered as 
 abandoned, or exchanged for the physical or external. 
 
 This unavoidable uncertainty has been well illustrated by 
 the greatest of petralogists. 
 
 * Bergman, the father of the system, derives the species from chemistry. 
 See also Brochant, i. 47. Jameson, i. xxv. 
 
 VOL. I. b 
 
Saussure's One cannot too often repeat that there must be found in 
 
 v Jfc % 
 
 fvfprinTTr.Tinv- 
 
 INTRODUCTION. 
 
 ften repeat that 
 observations. the mineral wor]( ^ and that in efl f ect in it are found, all the 
 
 mixtures in all imaginable proportions, from which proceed 
 an infinite number of mixed and undetermined kinds. 
 
 " If in the kingdom of organised beings, where the spe- 
 cific forms are determined by the seeds, it is often difficult to 
 mark the limits of the species ; how much more so to ascer- 
 tain them in one where only the force of cohesion unites the 
 elements, whatever be their nature, and in whatever propor- 
 tion chance collects them. 
 
 " It is for this reason that in this work I have avoided 
 giving names to the stones I have written of, when I have 
 not been able to ascertain them by decided marks, which 
 could fix their place in the known system of the nomen- 
 clature. 
 
 " Those who collect, and the nomenclators properly so 
 called, do not like these doubtful sorts, which it is too diffi- 
 
 ~ 
 
 even reject them entirely, because they appear to reproach 
 
 the imperfection of their systems. For this reason one sees, 
 in the greatest number of cabinets, only the sorts whose cha- 
 racters are decidedly known. There nothing stops you, all 
 is conformable to received systems, and all have fixed names. 
 But when nature is studied by herself, when one proposes, 
 instead of finding cabinet specimens, to study minutely all 
 the productions of the mineral kingdom, and is at the same 
 time jealous of a certain degree of precision, one finds at 
 every step individuals which it may be said to be impossible to 
 arrange under known denominations. One may then mark 
 the bounds 5 one may determine how far each individual ap- 
 proaches to, or recedes from, such and such a species -, but 
 one cannot positively affirm the name of the one or other of 
 these species."* 
 
 * Saus&ure, ii. 606. 
 
 cult to arrange under the known genera. They neglect or 
 
 
 

 INTRODUCTION. XIX 
 
 2. Order of the distinctive Characters. 
 
 The present work may be said to have passed through 
 several editions, before its public appearance ; and the por- 
 tions newly modified, or finally rejected, with the detached 
 discussions, composed in order to consolidate the progress 
 and universal consistency of the plan, would form a moderate 
 volume. These precautions became necessary, as upon an 
 unknown coast the discoverer employs boats to sound the 
 bottom, before the ship can advance with safety. Among 
 numerous difficulties, which will be perceived in proportion 
 to the learning of the reader, the arrangement of the cha- 
 racters, and the choice of one or two of the new terms, were 
 not the least. They now stand as follow: Texture, Hard- Order 
 ness, Fracture, Fragments, Weight, Lustre, Transparency 5 proposed, 
 to which the colour is sometimes added, though the most 
 vague and insignificant of all the characteristics. 
 
 Murray, in his excellent System of Chemistry, has justly Objections to 
 observed that it is difficult to attach precise ideas to arbitrary ciphers, 
 numbers. Every reader must have observed, that he passes 
 without reflection the ciphers 1, 2, 3, &c. when applied to 
 Hardness, Specific Gravity, Lustre, or Transparency. It 
 therefore seemed more advantageous to employ terms derived 
 from the substances themselves, which, though only relative 
 and recollective, yet convey ideas more clear, and, so to 
 speak, more tangible than barren ciphers. In this, and other 
 instances, the reader not conversant with modern mineralogy 
 may perhaps be surprised at the neology : but he must be . Neology 
 informed that the science itself is entirely new; and that mdl5 P eilsal > le 
 there is no recent mineralogical work which does not abound 
 with new terms, not to be found in any dictionary, but which 
 are indispensably necessary, in order to delineate substances 
 and qualities which did not before fall within the range of 
 human intellect or language. The names which have been 
 added to botany and zoology, within half a century, might be 
 

 
 Hardness. 
 
 INTRODUCTION. 
 
 counted by hundreds ; and in the progress of mineralogy, ; 
 similar neology cannot be avoided. While s-ome recen 
 authors of mineralogy pollute the classical language of ou 
 fathers with an inundation of barbarous German words, de 
 rived from the vulgar dialects of illiterate miners, who c 
 course first observed the distinctions between mineral bodies 
 it became the more an object of ambition to treat this diffi 
 cult subject with such a degree of classical purity, as not ti 
 disgust the eye of taste, contemn the discussions of gram 
 mar, or vitiate the eternal tenor of our language. 
 
 New terms. The new terms chiefly required, were to designate tin 
 degrees of hardness and weight, which had been indicated b; 
 ciphers, even by authors who used epithets to express thi 
 other characters. As Chalk, Gypsum, Marble, Basalt, Fel 
 spar, Rock Crystal, and Corundon, form various stages o 
 hardness, at the distance of 200 or more in the commoi 
 tables, they have been chosen to express the relative hardnes 
 of other substances, by the following terms : Cretic, Gypsic 
 Marmoric, Basaltic, Felsparic, Crystalic, Corundic. In orde: 
 to diversify the form of the epithets, the weight has beei 
 designated by another Latin adjective termination, that ii 
 osus, which some grammarians affirm generally to denot< 
 weight or labour, as laboriosus, ponderosus, operosus, &c. anc 
 the last word has even been admitted into classical English 
 in the form operose. As Pumice, Coal, Granite, Siderite 
 and Barytes, form a scale of gradations in weight, they ar< 
 here selected to denote that quality, as being Pumicose, Car- 
 bonose, Granitose, Siderose, Barytose. 
 
 But the characters themselves, and their arrangement 
 require further explanations. The Texture and Hardness 
 occupy the first place, because adepts generally examine then: 
 first, by means of the lens and knife. Dr. Townson has 
 observed that these instruments should always be in th 
 pocket of a mineralogist. " With the latter, after a littli 
 practice, he will be able readily to find the hardness of mosJ 
 fossils j and the former will furnish him with very accurate 
 
 Weight. 
 
INTRODUCTION. XXI 
 
 knowledge of their texture, and be of particular use in 
 many of his geological speculations on their formations."* 
 
 This skilful author has arranged his characters in the fol- 
 lowing order: Texture, Fracture, Lustre, Hardness, Fra- 
 gility, Transparency, Fragments, Colour. It is hoped the 
 present arrangement will be found more justly progressive 
 
 and connected. But after having advanced several coerent Townson's 
 . , . , . , . J difficulties, 
 
 arguments against Werner s arrangement, in his tenth chap- 
 ter, which treats of Classification, Description, and Investi- 
 gation, he strangely introduces the following remark in his 
 ninth chapter, on the Exterior Characters of Minerals, which 
 hence appears to have been written after the tenth. " Though 
 I have made some objections, in my tenth chapter, to the 
 order of the characters in the descriptions, disapproving of 
 their beginning by their least characteristic qualities, as co- 
 lour and accidental shapes ; yet I perceive, were I to throw 
 these further backward, other inconveniences would be the 
 consequence. The characters belonging to each of the three 
 different states of cohesion, as solid, friable, and fluid, are 
 placed under their respective heads ; but the colours, being 
 common to all the three, are placed first." This is certainly 
 a specimen of careless composition. The supposed inconve- 
 niences ought to have been indicated, if they did not consist 
 in the labour, certainly not small, of altering or rewriting 
 a system already composed, in order to render it coherent and 
 uniform. But the forcible arguments, in his tenth chapter, 
 remain unconfutedj and the arrangement of Werner's cha- 
 racters has met with other able opponents. His extreme Werner's 
 attachment to the distinction of colours, from which he has incon S ruitie ' 
 even deduced many improper, not to say absurd, appellations 
 of mineral substances, has led him to place this vague cha- 
 racteristic in the first rank. The incongruity of the concate- 
 nation has been justly ridiculed in other respects. From the 
 Lustre he passes to the Fracture, and from the Fracture to 
 the Transparency 5 from the Coldness to the Weight, and 
 
 * Philosophy of Mineralogy, London, 1798, 8vo. p, 187. 
 

 
 XX11 INTRODUCTION. 
 
 from the Weight to the Smell. It would certainly have been 
 more natural and rational to have joined the Lustre with the 
 Colour, and the Weight with the Hardness. His idea of the 
 successive use of the senses, in the examination of any mine- 
 ral, is quite imaginary j as before an examination with a lens, 
 it may be weighed in the hand, or its hardness tried with a 
 knife, &c. j and it would be ridiculous to build a science 
 upon simple exertions of the will. Independently of this new 
 kind of pedantry, derived from German metaphysics, it is 
 not the consideration what senses are first impressed, that 
 should regulate the succession of characteristics ; but, on the 
 contrary, their own intrinsic importance. Hence the TEX- 
 TURE is here placed in the first rank, though totally omitted 
 by Werner, or confounded with the fracture, with which 
 indeed it is intimately allied : but two other celebrated mi- 
 neralogists, Wiedenman and Estner, have justly introduced 
 the texture as a characteristic of the most radical importance. 
 In many cases it may be judged by the eye, but. in most 
 requires a lens. The hardness, which follows, may be tried 
 by the knife or file ; instruments indispensable to the mine- 
 ralogist. The weight may, after some experience, be esti- 
 mated by the hand; but some of the disciples of Werner 
 have confounded this external character with the specific 
 gravity, which belongs to the chemical class of characters. 
 
 Mr. Kirwan has justly observed the inaccuracy of Werner 
 and his disciples, who have confounded the texture with the 
 fracture. The most minute account of the former, is that 
 by Dr. Townson above mentioned. 
 
 Townsonon " The Texture, Textura, 
 
 the texture. 
 
 " Is the internal structure or disposition of the matter of 
 which a mineral is composed*. 
 
 
 
 * " Mr. Werner says nothing on the texture of minerals; but, under the 
 article of fracture, gives many characters which belong not to the fracture but to 
 the texture ; so that the characters of texture and fracture, though very different, 
 are united under one head and confounded together. But in the works of 
 

 
 INTRODUCTION. 
 
 C Without any distinguishable parts, or the ap- 
 < pearance of being composed of smaller 
 C parts. Examples, Chalcedony, Flint, c. 
 
 \ When composed of very minute, almost invi- 
 
 ) sible, rough parts, as clay, marl, &c. 
 I 
 
 r 
 
 \ When composed of small shapeless grains, as 
 
 \ S ranu ^ atec ^ quartz, sandstone, &c. 
 
 f When composed of small spherical bodies, as 
 Globuliformis \ the pisolithus and oolithus. 
 Fibrous ( When composed of fibres. Examples, Fibrous 
 
 Compact 
 Compacta 
 
 Dicht 
 
 Erdig 
 
 Granular 
 p , 
 
 Korni 
 Globuliform 
 
 Ftbrosa 
 
 Faserig 
 Fine 
 Coarse 
 Long 
 Short 
 Straight 
 Crooked 
 
 < gypsum and amianthus. 
 ' The fibres may be 
 
 Parallel 
 
 Paralldis 
 
 Divergent 
 Stellated 
 
 Divergentibus 
 Stellatis 
 
 Fasciculated 
 
 Fasciculatis 
 
 Decussated 
 
 Decussatis. 
 
 Tenuibus 
 Crassis 
 Longis 
 Brevibus 
 Rectis 
 Curvatis 
 
 When composed of long, narrow, flattish la- 
 mellae. This differs from the fibrous by the 
 parts being broader. Examples, grey anti- 
 mony, manganese, zeolite, actynolite, &c. 
 This admits of the same variations as the 
 preceding. 
 
 When composed of smooth continued leaves or 
 plates, covering one another. Example, as 
 the spars. They may be 
 Straight, Rectis, as in most spars ; or 
 Crooked, Curvatis, as in Schiefer spar > or 
 Spherical, Spharicis, as the mica hemisphaerica 5 
 Undulating, Undulatis, as in talc 
 
 Messrs. Wiedenman and Estner, there is an article under which several cha- 
 racters of the texture are given. Some of these I have arranged under this 
 article; others, under that of structure or compound texture. In Mr. Werner's 
 ewn work on the outward characters, this article does not exist." 
 
 Radiated 
 Radiata 
 
 Lamellar 
 Lamellosa 
 

 xxiv 
 
 
 
 Hardness. 
 
 Werner's 
 account. 
 
 Slaty 
 Schistosa 
 
 Scaly 
 Squamosa 
 
 Sparry 
 Spathosa 
 
 INTRODUCTION. 
 
 Composed of thin layers or beds, as slates. 
 As the preceding was more peculiar to the 
 crystallised, so is this to the rupestrious fos- 
 sils. As this is rather a character of struc- 
 ture than texture, probably it might be 
 omitted here. 
 
 f Composed of a congeries of small scales. Pe- 
 1 culiar to the plumbago, according to Estner. 
 Composed of a congeries of irregular crystal- 
 line parts, like coarse salt, as the coarser 
 kinds of scaly or saline limestone, as that of 
 Sala in Sweden, some hornblende-schistus. 
 This belongs to the granulated of the Wer- 
 nerian school. 
 
 " In judging of the texture, attention must be paid, when 
 it is not of the compact kind, but of the fibrous or lamellar, 
 that it is inspected in a proper direction, which is that of its 
 parts j otherwise, when in the opposite direction, the fibrous 
 may appear granulated, and the lamellar radiated." 
 
 Dr. Townson says that the structure is a particular dispo- 
 sition of the texture, as Hornblende-slate may have a sparry 
 texture and schistose structure; some iron ores, an earthy 
 texture and columnar structure. Of the Structure he only 
 indicates four kinds : 
 
 Slaty, Testaceous, Concentric, Columnar. 
 The first is too general, the three others too rare, to be of 
 real utility in a general system ; and this confined use of the 
 word Structure would interfere with its general use in other 
 senses equally appropriate. 
 
 The HARDNESS, another grand characteristic, may be best 
 illustrated in Werner's own words, which will at the same 
 time serve to convey some practical admonitions to the 
 student. 
 
 " After the particular generical characters discovered by 
 the sight, in solid fossils, follow those which may be observed 
 by the feel, the first of which is hardness, forming the tenth 
 in the general system. 
 
 
 
 

 
 INTRODUCTION. XXT 
 
 *< Upon handling different fossils, we soon perceive (to 
 use a familiar expression) that some are softer than others. 
 For instance, a piece of gypsum is much softer to the feel 
 than a piece of quartz. This difference is better observed 
 when we make use of some instrument fit for the purpose*. 
 This is what is termed by mineralogists the investigation of 
 hardness ; and, with respect to this property, we shall divide 
 solid fossils into hard, semi-hard, soft, and very soft. 
 
 " A fossil is called hard which cannot be marked or 
 scratched by the knife, or rather which emits sparks, being 
 struck by the steel. This degree of hardness is to be found 
 only in fossils which are perfectly brittle (Sprode). Hard 
 fossils are also distinguished into those which are affected by 
 the file; those which are but in a small degree; and those 
 which are not in the least. To the last belong the diamond, 
 ruby, and emerald ; in the second may be placed the topaz, 
 rock-crystal, amethyst, flint, chalcedony, carnelian, &c. which 
 yield a little to the file 5 among those on which the file takes 
 effect, are white copper- ore, micaceous iron-ore, hematite, 
 most compact iron stones, red and brown tin crystals, most 
 shining grey cobalt ores (speis kobolt), arsenical and sul- 
 phureous pyrites, c. 
 
 " Semi-hard is applied to a solid fossil which does not emit 
 fire with steel, and which may be marked or scratched by the 
 knife. Of this nature are fahlers, red copper-ore, sparry 
 
 * " The instruments employed by mineralogists in this investigation are, the 
 'knife for semi-hard and soft fossils, the steel for those which are hard, and the 
 file, for fossils perfectly hard. The knife may also be used to judge of the 
 streak and ductility. In order to possess a complete mineralogical apparatus, it 
 will suffice to add to these instruments a magnifier, which will often be wanted 
 to determine the exterior form and fracture, and which may be well observed 
 with a single glass; 2. a small phial ofaquafortis, the use of which I shall dis- 
 close in the last chapter; 3. a loadstone, which for convenience may be so ma- 
 naged as to serve at the same time for a steel. If there be also added a blow- 
 pipe, in order to make essays speedily upon minerals with the assistance of fire, 
 we shall possess all to be desired. These articles may all be met with, well 
 made and adapted, at Mr. Schubert's, Mechanic to the Academy of Mines, 
 Freyberg." 
 

 XXVI 
 
 INTRODUCTION. 
 
 iron-ore, hard earthy lead-ore, most blendes, white shining 
 cobalt-ore, native arsenic, kupfernikel, limestone, most cal- 
 careous spars and guhrs, fluor spar, zeolite, basalt, and many 
 others. 
 
 " Soft solid fossils are those which are easily affected by 
 the knife, but receive no impression from the finger-nail. 
 Such are white silver-ore, vitreous silver-ore, most red silver- 
 ores, vitreous copper-ore, mountain blue-ore of copper, most 
 bog iron-ores (Rosen eisenstein), galena, compact lead-ore 
 (bkyschwelf) , white and green lead-ore, red phosphoric blende 
 (from Scharfenberg near Meissen), amber, heavy spar in bars 
 (Stangen spat), mica, asbestos, serpentine, &c. &c. 
 
 " Very soft is applied to all solid fossils which are not only 
 marked by the knife, but upon which the finger-nail makes 
 an impression. Of this kind are most solid cinnabars, cor- 
 neated metals, or native metallic muriats, micaceous bismuth- 
 ore, grey ore of antimony, most earthy cobalt-ores, cobalt 
 flowers, oxyd of native arsenic, realgar, native sulphur, mi- 
 neral pitch, most pit-coal, plaster-stone, glades marice, talc, 
 black lead, most kinds of manganese, steatite ( Speck stein), 
 amianthus, chalk, &c. &c. 
 
 " But these different degrees of hardness are so apt to ap- 
 proach each other, that we find each of them not only of 
 many varieties, but very frequently observe fossils bordering 
 upon two degrees of different hardness, which varying a little 
 from both, forms a medium between these two degrees. For 
 example, hard magnetic iron-stone and opal, have nearly the 
 same hardness with semi-hard kupfernikel and basalt ; semi- 
 hard copper pyrites and malachite approach the soft heavy 
 spar and white lead-ore in hardness ; soft red silver-ore and 
 amber approach the very soft cinnabar and native sulphur. 
 It becomes therefore a matter of importance to determine the 
 hardness of a fossil, to indicate not the principal degree of 
 hardness alone to which it belongs, but also its relation with 
 known fossils of the same degree, and to observe when a 
 fossil forms a medium between two degrees. Thus, for ex- 
 ample, we shall say that fahlers, or grey silver-ore, is semi- 
 
 

 INTRODUCTION. 
 
 hard, but softer than copper fahlers, and harder than copper 
 pyrites -, that amber is soft, and forms a medium between 
 soft and very soft fossils."* 
 
 Not to mention the FRACTURE, FRAGMENTS, LUSTRE, 
 and TRANSPARENCY, which are described in the common 
 terms of most systems of mineralogy, it may be necessary to 
 add a few words concerning the other remaining character- 
 istic, namely, the WEIGHT. In this, as already mentioned, Weight. 
 a relative scale is proposed, instead of ciphers, which seldom 
 supply prompt or immediate ideas, especially as the reader 
 generally forgets the tables prefixed. The total dismission of 
 ciphers serves, at the same time, to render the arrangement 
 more uniform and harmonious. The Weight has been, by 
 many of Werner's disciples, confounded with the Specific 
 Gravity, which requires an operation, and does not belong to 
 the external characters of Werner ; while the Weight, with 
 some experience, may be estimated, as he says, by the hand. 
 His epithets, however, are in this instance particularly indis- 
 tinct, being Very light, Light, Rather heavy, Heavy, Very 
 heavy. His scale is also too brief, five degrees being neces- 
 sary for the gems and rocks, and five more for the metals. 
 For while the specific gravity of platina is about 21, gold 19, 
 silver 10, copper 8, iron about 7, and tin little inferior, 
 barytes only exceeds 4 ; so that there is a wide transition from 
 the heaviest stones to the metals, but not so great to the ores. 
 To the metals, therefore, another scale should be adapted for 
 common use. It is hoped that the one here proposed will be v 
 
 found sufficient for the purposes of petralogy ; and it is, like 
 the other improvements, submitted to the discussions and 
 alterations of the intelligent in a science which is quite new 
 and daily progressive. 
 
 3. Remarks on Werners Geognosy, or System of Rocks. 
 
 From the sketch imparted by Daubuisson to Brochant, 
 and from Mr. Jameson's Geognosy, we are enabled to form an 
 
 * Werner, Ch. Ext. p. 272. 
 
xxviii INTRODUCTION. 
 
 idea of Mr. Werner's system concerning the formation of 
 such parts of this planet, as we can hope to observe, little 
 exceeding the three thousandth part of its semi-diameter. I 
 warmly subscribe to the sentiments of admiration which are 
 paid to Mr. Werner's superior talents in many branches of 
 mineralogy, a science infinitely indebted to his industry and 
 sagacity. I also acknowledge the truth of the apophthegm, 
 Natura fecit omnes judices, paucos artifices. But I regret, with 
 his most enlightened admirers, that the scene of his inquiry 
 has been too confined ; and that his view of the mountains 
 of Saxony has not been extended over the globe. After forty 
 Saussure's years of sedulous observation among the Alps, Saussure, who 
 difficulties. ^ e g an hi s labours with a view of forming a system, declares 
 that his hopes were frustrated ; and that he had met with 
 such unaccountable confusion that he could not venture to 
 propose a theory. Yet Saussure, to practical observations on 
 a far superior scene, added the advantages of learning, and 
 mathematical and meteorological science, which Mr. Werner 
 unhappily wants, and which would have corrected and greatly 
 improved his speculations. 
 
 After describing the general appearance of the surface of 
 the earth, and the effects of water, he proceeds to consider 
 the structure of rocks, in their minute parts, and in their 
 general fabric ; the latter chiefly consisting of the stratified 
 structure, and that with seams, in which last he includes 
 Formations, columnar basalt. His grand doctrine of formations next 
 appears. When the mass is uniform, as in granite, gneiss, 
 limestone, the formation is said to be simple ; but when dis- 
 similar masses occur, as of coal and basalt, it is called com- 
 pound. When the formations consist of several substances 
 always found together, though in regions of different compo- 
 sitions, they are all called independent formations j but 
 when only associated, they are called subordinate. The uni- 
 versal formations are found all over the globe -, but partial or 
 anomalous formations are confined to particular spots. De- 
 Other terms, tached portions on the summits of hills are called caps j but. 
 when a part appears only on one side of a mountain, it is 
 
 

 
 INTRODUCTION. 
 
 XXIX 
 
 said to form a shield. When the superior strata have the 
 same direction with the fundamental rock, they are said to 
 be conformable with it ; but when the direction is different, 
 they are called unconformable. Sometimes they are simply 
 unconformable, as differing only in direction j but when in 
 addition to this they pass over the terminations of the inferior 
 rock,, they are said to be unconformable and overlying. 
 Strata may also be strait, form a mantle around the inferior 
 rock, cover its extremities in the shape of a saddle ; or, 
 when concave, assume the form of a bason or a trough. 
 
 Considering Mr. Jameson's work as notes taken during 
 Mr. Werner's lectures, it may be assumed that this illustri- 
 ous mineralogist then proceeds to consider the succession of 
 the different formations. Those rocks which are always 
 found inferior, are called Primitive ; and have a crystalline Primitive, 
 appearance, intimating a chemical solution, when the water 
 stood very high over the surface of the earth. The next 
 class is called Transitive ; which, though chiefly of chemical Transitive, 
 composition, exhibits also mechanical sediments and petri- 
 factions. The third class consists of Stratified rocks, styled 
 by Werner Floetz, signifying that they are in flat or hori- 
 zontal layers or beds; a stratified rock implying that the 
 strata are of one and the same substance j while the Floetz, 
 or rocks in layers, often present beds of different substances. 
 But this distinction is not of such utility or importance as to 
 necessitate the introduction of a barbarous word ; and if 
 stratified be not precise, we may use stratiformed with Dau- 
 buisson. The Alluvial and Volcanic rocks form the last 
 divisions. 
 
 It is to be regretted that the examples and facts are not 
 sufficiently numerous, but even the primitive rocks seem all 
 to be regarded as stratified, except granite, which is assumed Granite, 
 as the universally radical rock. In the Alps, Saussure has ob- 
 served that the granite presents marks of stratification. 
 Gneiss is also found under primitive granite ; and Mont Rosa, 
 nearly equal in height to Mont Blanc, consists chiefly of 
 gneiss and other stratified rocks. After long and diligent 
 
 Floetz. 
 

 
 
 INTRODUCTION. 
 
 
 
 
 
 
 Dissolutions 
 and sediments, 
 
 
 
 Sequences. 
 Objections. 
 
 inquiry, the position that granite is the universally radical 
 rock, would appear to be rather an assumption founded on 
 theory, than a fact supported by proofs 5 for if we examine 
 the accounts of the substances found at the greatest depths, 
 in coal mines and other excavations, there is no appearance 
 of granite 5 and if lavas often arise from a vast depth, a fact 
 now admitted from the prodigious extent of the preceding 
 earthquakes and other phenomena, the chief substance is iron 
 mixed with clay 5 and the mineralogical appearances tend to 
 confirm the opinion of astronomers and natural philosophers, 
 that the nucleus of this planet consists of iron j which, even 
 when native, is seldom found unmixed with silex, so that if 
 any rock can be called fundamental, it must consist of such 
 a mixture. It is true, that granite itself presents such a 
 composition, as iron is found in the mica, and still more in 
 the siderite, which in the oldest granites often supplies its 
 place 5 and what is chiefly to be regretted, is the want of 
 positive proofs concerning the anteriority of granite. 
 
 Werner proceeds to explain the effects of the gradual and 
 slow diminution of the primeval waters, in producing chemi- 
 cal dissolutions from a great height, and afterwards gradual 
 sediments ; so that, according to his theory, the shell of this 
 globe, instead of presenting a ruinous and unaccountable 
 confusion, exhibits, when viewed on a large scale, a regu- 
 larity and harmony, such as are admired in the other works 
 of the great Creator. 
 
 Having thus briefly explained this celebrated theory, it 
 must be added that the rocks are divided into various forma- 
 tions, which often receive arbitrary and unexpected epithets. 
 Thus the series called the SLATE FORMATION, is so named 
 from the central member SLATE, rising to mica slate, and 
 passing from gneiss into granite ; while, on the other hand, 
 the descent ends in coal, sand, and clay. It must strike every 
 enlightened observer, that such a distribution, instead of 
 leading to a just and accurate knowledge of rocks, as they 
 occur in different parts of the world, would only form an 
 illustration of the Wernerian system , which may, in the 
 

 INTRODUCTION. XXXI 
 
 progress of discovery, be found, like preceding systems, to be 
 essentially erroneous. If a work of petralogy were there- 
 fore founded upon this theory, it must fell with it : and no 
 writer of judgement or industry would choose to risk his 
 labour upon such an unoertain foundation. Nay, if the 
 theory were invincible, the arrangement would still be im- 
 proper for a student of petralogy ; who must follow the best 
 mineralogical authors, and arrange substances according to 
 their chemical compositions, and other infallible rules arising 
 from the nature and appearance of the substances themselves, 
 whether they exist in nature or in cabinets. A general 
 treatise on rocks therefore cannot be founded on any theory 
 of their formation, however plausible ; as the opinions of the 
 author will be biassed by that theory, and he will be inclined, 
 like Buffon, to reject or pass in silence any substance which 
 interferes with his preconceptions. Thus jasper is totally 
 omitted by Werner, though it form a chain of mountains in 
 Siberia, of more than a thousand miles, extending even to 
 the islands between that region and America. A disciple of 
 Werner is therefore embarrassed when he sees specimens of 
 rocks, not disposed in a theoretical sequence; and, in his 
 vindication, boldly asserts that rocks can only be studied in 
 nature, where the formations indicate the series of substances. 
 But as this argument would be ridiculous if applied to litho- 
 logy, or the knowledge of small or precious stones, so it is 
 equally inapplicable to petralogy; the distinctions between 
 large stones being as certain, and still more useful to society. 
 The knowledge of small and precious stones has been accom- 
 panied and greatly assisted by the constant introduction of 
 new denominations, which at present amount to about two 
 hundred; while the rocks of Werner do not exceed sixty, 
 although the distinctions between the rocks be not only 
 more numerous, but more apparent than those between the 
 parasitical stones. If the systems of botany and zoology 
 were founded on progressive formations, it is evident that no 
 two authoi-s could agree upon the links of the chain ; and 
 such systems have accordingly been founded upon character- 
 
XXXll INTRODUCTION. 
 
 
 
 
 istics derived from their exterior forms ; while, in mineralogy, 
 the forms of the greater masses being casual and uncertain, 
 recourse must be had to chemical analysis, as well as to exte- 
 rior qualities. But, in the former, it is not so much the 
 substances forming the combination, as the mode or manner 
 of that combination, which constitutes the essential differ- 
 ence among the objects of mineralogical knowledge 5 for the 
 diamond is only a modification of coal, and the sapphire of 
 clay and iron rust. Hence, while the mode of the chemical 
 combination establishes the most essential difference, the 
 structure and the aspect constitute more minute distinctions. 
 It may also be observed, that Werner's method of distin- 
 guishing rocks, by their formations and positions, seems at 
 variance with his treatise on the external characters of mi- 
 nerals, in which the science is rightly founded on its only 
 firm foundations, those depending on the characteristics of 
 the substances, as considered in themselves. This object was 
 perhaps considered by Werner as already accomplished in that 
 treatise, and in his lectures on Oryctognosy, or the general 
 knowledge of minerals : but the rocks form a class so im- 
 portant and distinct, that they deserved a separate considera- 
 tion, before proceeding to the bold design of general geo- 
 gnosy or geology. Perhaps the experience and observations 
 of two centuries may still be wanted, before such a design 
 can be reasonably attempted ; and at present the Huttonian 
 system has as many admirers as the Wernerian, though 
 founded on principles totally opposite : but, in all events, it 
 was necessary to begin with an elementary work, containing 
 all the erudition already acquired on the subject, leading to 
 more clear and precise views, or exact distinctions, and a 
 Necessity of consequent increase of denominations, without which even 
 must be embarrassed ; for at present it is not even 
 agreed what object precisely constitutes granite, and what 
 object basalt. All theories, however, tend to the advance- 
 ment of science, by stimulating inquiry and discussion ; but 
 it is clear that the theories must be vague, and the contests 
 .alike fruitless and endless, till the parties shall have agreed 
 
INTRODUCTION. XXX111 
 
 upon the denominations and definitions. For what hope of 
 any reconcilement of opinions, or any clear knowledge, when 
 the French persist at this moment in regarding basalt as com- 
 pact lava; while Dolomieu, the greatest of their mineral- 
 ogists, and at the same time a practical and sedulous observer 
 of volcanoes, has loudly declared that the basalt of the an- 
 cients is never a volcanic product ? 
 
 Petralogy therefore, or the knowledge of rocks, must, like 
 the other branches of mineralogy, be studied in cabinets as 
 well as in nature 5 and in the substances themselves, not in 
 supposed theoretical positions : for if the student cannot dis- 
 tinguish a rock without these adventitious aids, which in the 
 great variety of nature will themselves often lead to false 
 conclusions, he may be pronounced as truly ignorant of the 
 subject, as he who cannot distinguish gems without being 
 informed of their countries, sites, and gangarts. And this 
 would be the more absurd as it is self-evident, as already ob- 
 served, that large substances must present more palpable and 
 more numerous distinguishing characteristics than the 
 minute. 
 
 It must also be considered that Werner, by founding the 
 knowledge of rocks on a system of geognosy, has been led by 
 juxta-positions, and other accidental circumstances, observed 
 in the confined scale of Saxony, to diminish rather than to 
 enlarge the number of denominations j the result of which 
 practice would evidently be to obstruct the progress of the 
 science 5 and, as he is not versed in erudition, his own deno- 
 minations are sometimes unclassical, and so vague, as to give 
 no positive idea ; of which examples may be found in his 
 flinty slate, his slate porphyry, and his white-stone. Indeed 
 his new denominations in lithology being often founded on 
 colour, have been sometimes rejected*. To institute new de- 
 nominations, it is evident that erudition is necessary j and 
 this leads me to observe, that the study of preceding works 
 
 * When he classes the gems as siliceous, instead of argillaceous, he confounds 
 them with the false gems (rock crystals, &c.), which are siliceous, 
 
 VOL. I. C 
 
XXXIV 
 
 INTRODUCTION, 
 
 on the subject is indispensable to a complete treatise on pe- 
 traloey, which should enable the student not only to know 
 the substance, but the denominations used by former mine- 
 Studies ralogists and travellers, and by historians, philosophers, and 
 requisite. p 0e t s ^ which will not only enlarge his ideas but give him 
 more accurate knowledge. And as few of the sciences can 
 be founded on personal observations, vita brevis, ars longa, 
 and the brevity of human life will not permit a petralogist to 
 pass forty years in the Alps with Saussure, thirty in Saxony 
 with Werner, &c. &c. he will of course acquire infinitely more 
 knowledge by the study of their works, than by any personal 
 observations 5 so that this science, like all others, results 
 from accumulated knowledge. 
 
 These observations shall be concluded with Werner's ar- 
 rangement of the rocks. 
 
 Primitive Rocks. 
 
 8 Porphyry. 
 
 9 Sienite. 
 
 10 Topaz Rock.* 
 
 11 Quartz Rock. 
 
 12 Primitive Flinty Slate. 
 
 13 Primitive Gypsum. 
 
 14 White-Stone. 
 
 Werner's 
 rocks. 
 
 CLASS I. 
 
 1 Granite. 
 
 2 Gneiss. 
 
 3 Mica Slate. 
 
 4 Clay Slate. 
 
 5 Primitive Limestone. 
 
 6 Primitive Trap. 
 
 7 Serpentine. 
 
 CLASS II. 
 
 1 Transitive Limestone. 
 
 2 Transitive Trap. 
 
 3 Grey Wacke. 
 
 Transitive Rocks. 
 
 4 Transitive Flinty Slate. 
 
 5 Transitive Gypsum. 
 
 CLASS III. Floetz or Stratiform Rocks. 
 
 1 Old Red Sandstone, or 
 
 first Sandstone Forma- 
 tion. 
 
 2 First, or oldest Floetz 
 
 Limestone. 
 
 3 First, or oldest Floetz 
 
 Gypsum. 
 
 4 Second, or variegated 
 
 Sandstone Formation. 
 
 5 Second Floetz Gypsum. 
 
INTRODUCTION. 
 
 XXXV 
 
 6 Second Floetz Limestone. 
 
 7 Third Floetz Sandstone. 
 
 8 Rock Salt Formation. 
 
 9 Chalk Formation. 
 
 10 Floetz Trap Formation. 
 
 CLASS IV. 
 
 1 Peat. 
 
 2 Sand and Gravel. 
 
 3 Loam. 
 
 4 Bog Iron Ore. 
 
 11 Independent Coal Form- 
 
 ation. 
 
 12 Newest Floetz Trap 
 
 Formation. 
 
 diluvial Rocks. 
 
 5 Nagelfluh. 
 
 6 Calc-tuff. 
 
 7 Calc-sinter. 
 
 1 Burnt Clay. 
 
 2 Porcelain Jasper. 
 
 3 Earth- Slag. 
 
 CLASS V. Volcanic Rocks. 
 Pseudo Volcanic Rocks. 
 
 4 Columnar Clay Ironstone. 
 
 5 Polier, or Polishing Slate. 
 
 True Volcanic Rocks. 
 
 1 Ejected Stones and Ashes. 
 
 2 Different Kinds of Lava. 
 
 3 The Matter of muddy 
 Eruptions. 
 
 4. Admission of Iron as an Earth. 
 
 The admission of iron, not as a metal, but as an earth, 
 may occasion some hesitation ; and a few preliminary obser- 
 vations become necessary. Many eminent mineralogists and Admitted by 
 geologists have led the way to this improvement, though 
 they have not formally introduced it into a system. It may 
 be preferable to adduce their testimonies in chronological 
 order. 
 
 Linneus has thus expressed himself, in his brief and em- Linneus. 
 phatic language : " I have sedulously enquired, during my 
 various travels, into the production of stones, and have 
 learned that it is effected by precipitation and crystallisation ; 
 and that earths are deposited, while quartz, felspar, and mica 
 rise up. The female earths are impregnated by the male 
 
XXXV 1 
 
 INTRODUCTION. 
 
 salts, whence a more noble progeny -, but many of the latter 
 are derived from Iron, a Proteus who changes according to 
 
 Influence of the disposition of each wife."* He thus insinuates his opi- 
 iron. m - on O f the wide influence of iron, a metal which belongs to 
 all ages and formations $ and whose power is prodigious and 
 perpetual, even in animal and vegetable life. Bergman has 
 indeed asserted a similar wide diffusion of gold, which has 
 escaped the more recent and precise tests of chemistry, and 
 is now rather regarded as imaginary j while the most nume- 
 rous and exact experiments more and more evince the uni- 
 versality of iron, which drops even from the atmosphere as 
 the chief ingredient of what are called meteoric stones, and 
 supplies volcanoes from the lowest abysses of the earth. Iron, 
 the grandest of the metals, is not only the most widely dif- 
 fused, but the most useful to mankind in all the stages of 
 society, and without it civilisation would be unknown ; as it 
 . furnishes the spade and the plough to the agricultor, tools to 
 the artisan, the compass to the mariner, armour and weapons 
 to the hero, and ink to the eternal theme of the author. 
 But waving these considerations, Linneus has thus sufficiently 
 expressed his opinion of its influence in the constitution of 
 rocks and stones. 
 
 Cronstedt. Cronstedt, who may be called the grandfather of modern 
 mineralogy, as Bergman is the father, had long ago a faint 
 discovery of this truth 3 for among his nine earths, several 
 of which have since been discarded, he reckons Garnet Earth, 
 which, as that substance is strongly impregnated with iron, 
 
 Bergman, can only be the aiderous earth here mentioned. Bergman 
 also, in his Sciagraphia, which laid the foundations of modern 
 mineralogy, especially reckons the ferruginous among the six 
 principal earths, as he includes the barytic. In his account 
 of carbonate of lime, he mentions that it is seldom free from 
 
 * Lithogenesiam studiose in itineribus quoesivi, dedicique earn absolvi Prse- 
 cipitatione et Crystallisatione ; atque Terras prosterni, sed Quartzum, Spatuni, 
 Micamque, exsurgere. Terras femineas dein impregnari a Salibus masculis, 
 indeque prognasci Nobiliores ; horum vero plurimos a Marte, Proteo magis 
 TOUtabili, pro indole cujuscunque conjugis. Linn, a Grnelin, p. 4, 
 
INTRODUCTION. XXXV'h 
 
 iron, which is found even in the most transparent, the calca- 
 reous spar of Iceland ; ee and it may be said in general that 
 all minerals contain that metal."* 
 
 To these eminent testimonies may be added Kirwan, who Kirwan. 
 has nearly approached to this division ; for, after describing 
 the simple earths, he proceeds as follows : 
 
 "" Calces of Iron. To these simple earths we must also 
 annex the consideration of calces of iron, as they almost 
 always accompany earthy or stony substances, are mixed or 
 combined with them, and are the source of many both of 
 their external appearances and internal properties. 
 
 " Calces of iron are formed of iron, combined with dif- 
 ferent proportions of pure air, and frequently of water also, 
 and fixed air. 
 
 " One hundred parts metallic iron are capable of taking 
 up 66 or 70 of pure air. When 100 parts iron contain but 
 40 of this air, the compound is still magnetic, "f 
 
 In another place, after observing that any earth which 
 forms less than one twentieth of a compound, is seldom of 
 any importance, he proceeds to state that calces of iron in- 
 fluence in some measure the properties of a compound, even 
 when they do not exceed one thirty- third part of the whole, 
 that is, three in the hundred - 3 and if they be themselves 
 magnetic, they communicate that property to compounds of 
 which they form above one tenthf . 
 
 In a later production, and with more ample information, 
 he presents the following remarks. ' ' The proportion of the 
 different materials contained in the chaotic fluid to each 
 other, may be supposed upon the whole nearly the same as 
 that which they at present bear to each other $ the siliceous 
 arth being by far the most copious -, next to that, the fer- 
 
 * Fr. tr. 1792, i. 170. ii. 378. 
 
 f- Min. i. 17. Calces were powders, now called oxyds. Thomson, i. 132. 
 
 1 Ib. p. 48. In his treatise on the Magnet (Mem. R. I. A. vi.), Mr. Kir- 
 wan says that iron abounds in all minerals, from 2 to 25, but at a medium 6. 
 This globe, he adds, is 4.5 heavier than water; and, p. 182, thinks the centre 
 iron; and afterwards calls it a great magnet, in which Hauy coincides. 
 
XXXV111 
 
 INTRODUCTION. 
 
 .ruginous; then the argillaceous and calcareous; lastly, the 
 magnesian, barytic, Scottish, and Jargonic, in the order in 
 which they are named j the metallic substances (except iron) 
 most sparingly." After such illustrious authors, it is scarcely 
 necessary to mention the similar ideas of Lametherie*. 
 Dolomieu. In his celebrated memoir on rocks, Dolomieu observes that 
 they are chiefly composed of four principal earths, to which 
 may be joined iron, or the earth which produces it : and he 
 adds that, in this memoir, " he never considers iron under 
 the relation of its metallic properties, but as a simple earth, 
 susceptible of the same kinds of combination as the other 
 elementary earths."f In his theory, Dolomieu supposes that 
 the precipitation of the principal earths took place in the fol- 
 lowing order : the siliceous, the argillaceous, the magnesian ; 
 contemporary with which two last, was that of the ferru- 
 ginous, or, as it is here denominated from the Greek, side- 
 rous ; and last of all the calcareous J. 
 
 In the continuation of this memoir he considers the .ag- 
 gregation of the five principal earths, estimated according to 
 its comparative force, to be in the following arrangement : 
 siliceous, argillaceous, ferruginous, calcareous, and magne- 
 sian. He remarks, as a singularity in the ferruginous earth, 
 that it often lends more hardness and solidity to masses 
 where it is simply mingled, than it can acquire when it is in 
 a state of purity. He afterwards proceeds to various observa- 
 tions on the force of adhesion of these five principal earths, 
 and gives a table to illustrate this quality. 
 
 Patrin Patrin, who often looks upon nature with an original and 
 
 inquisitive eye, has introduced many illustrations of the ne- 
 cessity of the siderous division. Among the primitive schisti 
 he enumerates " Ferruginous Slate. This slate is chiefly 
 composed of indurated clay, abundantly mixed with Oxyd of 
 Iron, either black or brown, but sometimes yellow or red, 
 
 * Theorie de la Terrc, Tome i. p. 435. Tome iv. p. 45, &c. 
 f Journ. de Physique, Tome 39, for 1791, p 374. 
 I Ib. 382. 
 
INTRODUCTION. 
 
 with a little quartz, and a considerable portion of mica. 
 This rock is one of the most common in the northern coun- 
 tries, where iron is singularly abundant. The eastern side of 
 the Ural mountains, for an extent of about five hundred 
 leagues, from north to south, is almost entirely composed of 
 it." He afterwards observes, that in Siberia many moun- 
 tains are composed of trap or basalt, (e containing masses or 
 veins of granite ; while the granitic mountains often contain 
 veins and masses of trap or hornblende."* This last obser- 
 vation may be universally extended $ and evinces that siderite, 
 and even trap or basaltin, is at least as ancient as granite, 
 which has hitherto been gratuitously admitted as the most 
 ancient of all the rocks. He also adds, that he has seen 
 large mountains of hornblende, or siderite, in the Altaian 
 chainf. 
 
 In treating of iron, Patrin observes that the veins or beds 
 of iron ore, are constantly parallel to the beds of the rock, 
 which in the primitive mountains are often vertical, and 
 seem from the first to have formed an integral part of the 
 mountain which contains them; whence Buffon has called 
 them primordial mines $ whilst the veins of other metals 
 almost always intersect these beds under different angles, 
 sometimes even at right angles, and evidently appear to have 
 been of a formation posterior to that of the rock. He pro- 
 ceeds to observe that the mountain of Blagodat, on the 
 eastern side of the chain of Ural, consists of thick beds of 
 iron, separated by others of slate and a kind of trap. In 
 that of Keskanar, in the same quarter, the celebrated mag- 
 nets are mixed with a quantity of greenish siderite in small 
 spots, and extremely resplendent when the stone is polished. 
 In the Altaian chain, vertical beds of an ochry slate alternate 
 with compact beds of black iron ore. The primordial beds 
 are chiefly composed of black iron ore, often magnetic 5 the 
 strongest magnets of Siberia being those which present la- 
 minar parts, sometimes of iron, sometimes of hornblende or 
 
 * Min. i. 120, 127. f Ib. 132. 
 
l INTRODUCTION. 
 
 serpentine. The nucleus of the earth, as he observes, must 
 be chiefly ferruginous, as is not only announced by the gene- 
 ral phenomena of magnetism, but by the observations and 
 experiments of Maskelyne and Cavendish, which show that 
 the specific weight doubles that of rock crystal*. 
 
 In his mineralogy, Patrin begins with a description of the 
 primitive rocks, which he introduces by that of the chief 
 substances of which they are composed, . namely, quartz, 
 felspar, mica, and schorl. This last term is generally used 
 by the French geologists for siderite or hornblende. ' ( Often," 
 says Patrin, " it forms considerable masses of rock, and 
 even entire mountains. When the schorl- rock presents a 
 distinct laminar texture, it is called hornblende ; when the 
 texture is of an earthy appearance, it is named Corneene" 
 This last word is often used by the French for basaltin. 
 Thus, in the opinion of this great observer, who has passed 
 many years in the mountains of Siberia, schorl or horn- 
 blende, composed of siderous earth, is as primitive as any of 
 the rocksf. 
 
 Magnetism. But while these great geologists admit the ferruginous or 
 siderous among the principal earths, they seem never to have 
 connected this idea with that of most writers on magnetism; 
 who, in order to explain that phenomenon, are forced to 
 admit that the nucleus of this our planet is a mass of iron : 
 and as, according to all theories, the substance which is 
 nearest the centre must be the most ancient, of course the 
 siderous earth must often partake of this antiquity; and in- 
 stead of ranking it, with Dolomieu, in the third or fourth 
 succession, it may be more properly classed in the first. In 
 the mica of granite, and often in the felspar, and even in the 
 quartz, a portion of iron is discoverable : and basalt, which 
 ^ contains a large portion of iron, is sometimes intermixed 
 
 * Min. v. 11, 4$, 241. The mountains of Selinga, he says, are chiefly of 
 hornschieffer and hornblende. 
 
 f Siderite and schorl shoot across quartz and felspar, so are more ancient : 
 so siderite and basalt intersect granite. 
 
INTRODUCTION. ill 
 
 with primeval granite*. In the other most ancient rocks, 
 particularly those of hornblende or siderite, iron also abounds; 
 as it does in jasper, common slate, trap, serpentine, and the 
 oldest sandstone. 
 
 It may be necessary, however, to introduce a distinction 
 between the Siderous Earth and metallic iron, which must 
 depend upon the proportion to be found in various substances. 
 As the alkaline earths, though they yield metals, will scarcely 
 by any mineralogist be classed among metallic substances 5 so 
 Siderous Earth, though it yield iron, may be admitted among 
 the other principal substances of that class. In fact, as the Dr. Davy'* 
 recent discoveries of Dr. Davy evince that the alkaline earths, di 8 " 68 - 
 that is the calcareous, magnesian, barytic, strontianic, are of 
 a metallic nature or yield peculiar metals, while he suspects 
 the other earths to be in the like predicament (as the sili- 
 ceous has since proved), it would be absurd to reject iron as 
 an earth, merely because it yields a metal. 
 
 It has already been seen that the presence of this earth, Power of iron, 
 even in a small quantity, is so powerful as greatly to affect 
 the compound ; and, by altering the quality of its mode, 
 even to change its substance and denomination. Among 
 many examples may be mentioned the hyalite of Dauphiny, 
 which only contains 10 of iron in 100, yet the form of the 
 crystals is that of the iron ore of Elba. Many mineral sub- 
 stances receive their denominations, not from the abundance, 
 but from the influence of particular earths ; for the greater 
 part of the argillaceous and talcous rocks contain two thirds 
 or three quarters of silexj so that if the abundance alone 
 were regarded, two of the chief denominations of the mi- 
 neral kingdom would be rejected. In many instances, the 
 energy of one ingredient has far more force than the abun- 
 dance of another. An able chemist, after discussing some Energy of 
 difficulties of this kind, thus proceeds : < < These circum- in re ients - 
 stances no doubt arise from the modes of chemical analysis 
 
 * The granite of the Hartz even affects the Magnet. Jam, Miu. Sc. Isles, 
 p. 65. 
 
lii INTRODUCTION. 
 
 being yet imperfect; and particularly from our being still 
 almost wholly ignorant of what determines the properties of 
 compounds so complicated as minerals generally are. All the 
 ingredients are not to be regarded as equally energetic, or as 
 in the same proportion contributing to the peculiar constitu- 
 tion of a compound ; and if one, which in its relation to 
 others is comparatively feeble in its action, be present in 
 large proportion, it leads to erroneous conclusions, when, in 
 determining composition, we attend merely to the relative 
 quantities of the principles, without attending to their rela- 
 tive energies. This has been generally hitherto done; and 
 among the earthy fossils, the predominating principle has 
 always been regarded as that which is present in largest pro- 
 portion, though the reverse is probably frequently just."* 
 
 5. Miscellaneous Observations. 
 
 This introduction shall be closed with some miscellaneous 
 remarks, which may not be found unuseful for the previous 
 consideration of the reader. 
 
 The science A grand cause, as elsewhere observed, of the slow progress 
 too extensive. Q m ineralogy, when compared with other parts of natural 
 history, is that it is too wide for the labours of one man ; 
 whence some important parts have remained uncultivated, 
 while others, often comparatively minute, have been discussed 
 with great care and anxiety, according to the peculiar studies 
 and inclinations of the several authors. The progress of 
 zoology and botany has been greatly assisted by the publica- 
 tion of detached works upon several divisions j and even the 
 mosses and lichens have been found sufficient for one man's 
 attention, in the brevity of human existence. Recent authors 
 
 * Murray's Chemistry, iii. 7. He had already said, p. 5, " each simple 
 earth giving its name to an Order, under which are arranged the fossils in 
 which it is predominant, or to which it gives a predominating character" And 
 so Bergman, the father of modern mineralogy, in the preface to his Sdagra- 
 phia, 1782 : "I have derived the genera from the dominant principle} and the 
 species from the diverse mixtures." 
 
INTRODUCTION. 
 
 upon these two kingdoms have hence been enabled to glean 
 
 the most interesting topics, and to form general compilations 
 
 of great merit and accuracy. For as vita brevis, ars longa, 
 
 was the axiom of Hippocrates, who compiled his classical pro- 
 
 ductions on medicine from cases preserved in the temples, so 
 
 in all the other sciences, the mere observations of one man ^ 
 
 will not constitute a science or a system. Saussure passed 
 
 forty years amongst the Alps ; and if the years consumed by 
 
 other travellers and authors, whose works have been used in 
 
 the present compilation, were computed, they might amount 
 
 to a thousand ; a period belonging to nature and science, 
 
 but not to man. Hence the utility of general systems or Utility of 
 
 compilations, which, by combining in one view the observa- com pi j ations. 
 
 tions of practical or scientific predecessors, not only by colla- 
 
 tion and elision render them more intelligible, but ascertain 
 
 the progress attained by any science 5 so that future diligence 
 
 may not be wasted in the investigation of subjects already 
 
 illustrated, but be directed to such parts as remain unculti- 
 
 vated and obscure. In this also, as in the other sciences, 
 
 more genius is required to build a system, than to make 
 
 observations. In the latter, Newton must yield to Herschel. 
 
 As the study of mineralogy commenced upon principles Petralogy dif- 
 afterwards found to be inadequate and erroneous; so, by a fersfrom 
 similar fatality, the study of rocks has been confounded with 
 what is called geology, or the doctrine of the constitution of 
 this globe, which rather belongs to natural philosophy. 
 Petralogy, like lithology, or metallogy, is a science which 
 must be studied by the geologist ; but a theory of the earth 
 may as well be studied in a pebble, as in a rock $ and the 
 neglected plains, as being nearer the centre of the earth, 
 must afford more topics than the lofty rocks and the moun- 
 tains. There is no reason, therefore, particularly to connect 
 petralogy with geology, or what some call geognosy : and it 
 would be alike absurd and useless if a rock could not be 
 classed, without a dissertation to determine its antiquity. 
 Nor can any reason be perceived why Werner should regard 
 
INTRODUCTION. 
 
 empirical characters as the chief in regard to the rocks, 
 while he justly considers them as the last and meanest in the 
 consideration of other mineral substances. Here, as in other 
 provinces of the mineral kingdom, there is no infallible 
 guide but Chemistry j upon which alone a rational and dura- 
 ble system can be founded. And if, as some few suppose, 
 chemical operations lead us to educts instead of products, 
 the difference remains the same, and the distinctions equally 
 clear. 
 
 Futility of Yet some ingenious men, who have made a tour of a few 
 little tours, j^^red miles, aspire to the study of geology, and speak of 
 their observations with all the pride of ignorance, and all the 
 vaunts of enterprise 5 while one simple perusal of Saussure's 
 work would teach them that they knew nothing. In the 
 momentary duration of human life, as man writes with his 
 hand on the table and his foot in the grave, infinitely more 
 knowledge must be acquired by the study of former authors, 
 than by trifling observations, which would probably not even 
 have been made if the fugitive traveller had previously studied 
 the subject, or had even once revisited the spot, as Ferrara 
 has observed of Dolomieu. While an author in his cabinet 
 studies the whole globe, and the collective labours of two 
 thousand years, these little journeys only impress him as 
 puerile excursions j and, in conversation, he regrets to find 
 the smallest tourists the greatest boasters. Da Costa has 
 illustrated this truth by a ludicrous story : Dr. Meara, having 
 the greatest respect for his own abilities, and regarding his 
 own discoveries with much admiration, was travelling on 
 Landsdown near Bath, when he observed a kind of chalk, of 
 quite a new species if not genus, being of a white colour, 
 remarkably pure, but above all very hot in the mouth -, and 
 in consequence he wrote a dissertation to prove that this 
 chalk alone was the long investigated cause of the heat of the 
 Bath waters. This celebrated discovery has passed into the 
 last edition of the valuable mineralogy of Wallerius, who 
 even quotes Da Costa as his authority for this new chalk, 
 
INTRODUCTION. Xv 
 
 though that patient writer had only mentioned it, to inform 
 his readers that it was unslacked lime, which had fallen from 
 a broken cart. 
 
 Such tourists, while they have themselves seen as little as Study of rocks, 
 they have read, are as loud as Dr. Meara in their assertions 
 that rocks can only be studied in nature j while, in fact, it is 
 as impossible to discern rocks from nature alone, as from 
 books alone. The one must assist the other. The vague- 
 ness of ideas in the works of Dolomieu and Faujas, and 
 many other observers, is such that nothing can be learned. 
 But how distinguish rocks, or acquire accurate knowledge, Necessity of 
 from works of which the authors cannot distinguish a granite 
 from a porphyry, &c. ? If, in zoology, a horse was called a 
 lion by one writer, a tiger by another, a leopard by a third, 
 and a panther by a fourth, what knowledge could be acquired ? 
 or if, in botany, the rose of one author was the lily of an- 
 other, while others styled it by a hundred different names ? 
 While Buffon and his disciples speak with contempt of nomen- 
 clature, they might as well tell us that in civil history the 
 actions of Pompey might be ascribed to Caesar, and those of 
 Anthony to Cleopatra, for of what consequence are names ? 
 Saussure, with his usual judgement, pursued a very different 
 course ; and the most laborious parts of his work are evi- 
 dently those in which he attempts to establish a precise 
 nomenclature. It may safely be asserted that the science can 
 have no foundation till a precise and rich nomenclature be 
 established j and that till then it will remain a chaos, and 
 not a world. 
 
 The student of rocks must therefore begin with a precise 
 nomenclature, as otherwise his observations cannot be of the 
 smallest utility. If he mean to pursue this study, he may 
 also find it more interesting to pass from this arid subject 
 to the beauties of crystallisation and the metals -, and thus 
 from great and general ideas descend to minute. The 
 student of zoology would scarcely begin with entomology. 
 But even among the authors of mineralogy there are ore and 
 dross : and who would believe that an hundred authors have 
 
l v j INTRODUCTION. 
 
 fallen into the grossest errors concerning ophite, &c. because 
 they neglected to consult the original passages ? 
 
 Apology for In the present work, it is hoped that the want of attention, 
 this work. c&r ^ Qr j^^ w ju no t be accused. The author has sedu- 
 lously employed the intervals of ten years in this production, 
 particularly three which he passed at Paris, where he had 
 constant opportunities of seeing the most opulent cabinets, 
 and of conversing with men eminent in the science, as 
 Patrin, Gillet Laumont, Daubuisson, and others ; not to men- 
 tion interviews with Haiiy, and with Werner during his short 
 stay in that capital. It was resumed at intervals of other 
 studies, the change of labour being itself an amusement. 
 He hopes the work may at least aspire to the humble praise 
 of utility, the chief aim of his labours : terar dum prosim. 
 In the preface to his grand treasure of ancient knowledge, 
 Pliny has observed that it is laudable to mention the authors 
 by whose works you profit. Not contented with exact refer- 
 ences, the author has often adduced the original passages, 
 not only for the sake of greater accuracy, but to save the 
 reader the trouble and expense of consulting many works, 
 which perhaps contain only a few pages on this particular 
 subject, which has hitherto been treated as a mere appendage 
 to mineralogy. There are also numerous extracts of great 
 value, from works in foreign languages, of which, from 
 their nature, the English reader can scarcely ever expect to 
 see complete translations. These extracts will, it is hoped, 
 from the variety of the style, throw some flowers over a sub- 
 ject proverbially barren 5 while the expressions of the ob- 
 servers themselves, in the sensations arising from grand phe- 
 nomena, sometimes enliven the subject with somewhat of a 
 dramatic interest. It must also be remembered, that mosaic 
 is even more difficult than painting, and of incomparably 
 longer duration. Some regard it as a maxim in literature, 
 that a book should be as complete in itself as possible ; and a 
 reference to a work, which he can neither procure nor read, 
 would cont rib ute little to the instruction of the learner. The 
 candid will likewise consider the entire novelty of the plan > 
 
INTRODUCTION. 
 
 which, while it required a minute attention to the congruity 
 of the parts, must also, like a new road, lead to mistakes 
 and deviations, perhaps more numerous than the author can 
 conceive ; and which, if pointed out with benevolence, he 
 will be ever ready to correct with gratitude. " Those who 
 have gone before us," says an ancient classic, " have done 
 much, but they have not finished j much labour still remains, 
 and much will remain ; nor will an occasion be wanting of 
 adding somewhat even to authors who shall be born after a 
 thousand ages."* 
 
 * Sane multum i!li egerunt, qui ante nos fuerunt, sed non peregerunt; 
 multum adhuc restat eperis, multumque restabit, nee ulli nato post mille 
 secula praccludetur occasio aliquid adjiciendi, SENECA. 
 
 xlvii 
 
SIDEGEA, SIDEROUS EARTH. 
 
 name sidegea, as not unusual iii 
 compounded words, is abbreviated from 
 two Greek terms, signifying iron and earth. 
 The reasons for the introduction of this 
 grand division, adopted in substance by 
 the most eminent geologists, have already 
 been given. Iron acts so important and 
 
 VOL. I. B 
 
DOMAIN I. SIDEROUS. 
 
 radical a part in the constitution of our 
 planet, that it deserves to be viewed under 
 various aspects, not only as a metal, but 
 as an earth, strongly impregnating most 
 of the others, and often exerting a pre- 
 dominating influence. For as, since the 
 recent discoveries, many earths have been 
 known to assume the form of metals, so 
 there can be no impropriety in considering 
 this universal metal under the form of an 
 earth. 
 
 When a substance contains more than 
 twenty-five parts in the hundred, or, in 
 other words, one quarter, of iron, it may 
 be worked as a metallic ore, and arranged 
 under that denomination. But in a smaller 
 quantity it will fall under the present divi- 
 sion, especially when intimately combined 
 with the other earths. It was by metallo- 
 gists considered as a calx, or latterly called 
 an oxyd. Mr. Kirwan*, who has rightly 
 added calces of iron to his description of 
 the earths, says, that they are formed of 
 that metal, combined with different pro- 
 
 * * Min.i. 17. 
 
00MAIN I. SIDEROUS. 
 
 portions of pure air, and frequently of water 
 also and fixed air, 
 
 " One hundred parts metallic iron are 
 capable of taking up 66 or 70 of pure ail 4 . 
 When 100 parts iron contain but 40 of this 
 air, the compound is still magnetic/' His 
 table of the fusibility of the simple earths 
 presents some curious experiments on the 
 mixture of calcined iron and rust of iron* 
 with other substances, which show the 
 power of this metal. Even when it only 
 amounts to four parts in the hundred, it 
 sensibly influences the compound. 
 
 Sidegea, or siderous earth, is so generally 
 diffused, that almost every mineral sub- 
 stance derives its colour from it, from a 
 pale blue to the deepest red* Animal sub- 
 stances contain it ; and it exists in the ve- 
 getable kingdom, even in plants apparently 
 supported merely by air and water. It 
 would appear that even the atmosphere 
 abounds with atoms of iron, whence per- 
 haps the meteoric stones. 
 
DOMAIN I. SIDEROUS. 
 
 MODE I. SIDERITE. 
 
 characters 6 Texture, generally crystalline, as in the saline 
 or primitive marbles ; the prisms sometimes in- 
 tersecting each other, so that it becomes difficult 
 to determine their figure*. The grains are 
 ^sometimes so small that it assumes a compact 
 appearance, in which case it passes into basalt. 
 
 Hardness, basaltic, sometimes only marmoric. 
 Fracture commonly foliated, sometimes radiated, 
 tough. Fragments rather sharp. 
 
 Weight, siderose : sometimes approaching the 
 barytose. 
 
 Lustre, splendent, shining, between vitreous 
 and pearly. Opake; the green sometimes trans- 
 lucent on the edges. 
 
 Colour generally black, sometimes of a green- 
 ish grey. 
 
 Siderite sometimes composes entire mountains a 
 but more commonly occurs disseminated, or 
 forming veins or nodules, in granite ; or beds in 
 gneiss. 
 
 This important substance, which is so widely 
 
 Hornblende, disseminated, is the hornblende of the German 
 
 miners; a barbarous term, which, like many 
 
 * The crystals of siderite are of an oblong quadrilateral form, 
 while those of mica are hexagonal. 
 
MODE I. SIDERITE. 
 
 others, had passed into the science before it be- 
 came classical*. 
 
 " Mountains of black hornblende exist in Si- sites. 
 beria, Renovantz, 32 : as the Tigereck, 4 Nev. 
 Nord. Beytr. 192; and others mentioned by 
 2 Herm. 271. Frequently mixed with quartz, 
 mica, or felspar, or shorl[ and either greenish or 
 black. Ibid. But it is more commonly fpund in 
 mighty strata, as in Saxony ; or still oftener as a 
 constituent part of other primeval rocks, as in 
 syenite and grunstein; sometimes in layers in 
 gneiss, or granular limestone, or argillite ; and 
 sometimes in horn porphyry. 2 Berg. Jour. 
 1788. 508. 1 Lenz. 325. 1 Emmerling, 325; 
 or in the gullies of granite. Herm. Ibid. Horn- 
 blende slate was observed among the primeval 
 rocks on the ascent of Mont Blanc, 7 Sauss. 
 241, 253, mixed with plumbago ; Ibid, and on 
 its summit, Ibid. 289." 
 
 " Strata of schistose hornblende occur some- 
 times in gneiss, as already mentioned. At Mil- 
 
 * Blend, in German, sometimes implies Hind, sometimes false 
 or deceitful ; but the name seems rather to have arisen from its 
 having the appearance of blende, an ore of zinc, which was also 
 called pseudo galena. Blend, or in modern German Hind, never 
 has the final e : and there would be no sense in Hind horn. But as 
 the substance much resembles black blende, and, when struck, often 
 crumples like horn, the etymology is very clear. A French writer 
 rightly translates it Blende de corne. Hornstein and Hornsilver are 
 translucent as horn. 
 
DOMAIN I. SIDEROUS. 
 
 tiz a stratum of it has been found over granulay 
 limestone. Voigt Prack. 33. In Lower Silesia 
 it has been found on syenite. 4 Berl. Beob. 
 349. Granite sometimes rests on it. 2 Berg. 
 Jour. 1790, 300. Voigt Mineral. Abhaudl. 25. 
 Hence there can be no doubt of its being a pri- 
 mitive stone. A mountain of it exists in Tran- 
 sylvania; 1 Bergb. 40. Nay, granite has been 
 found in it. 1 Berg. Jour. 1789, 171. It is fre- 
 quently mixed with mica, more rarely with 
 visible quartz : Emmerling*." 
 
 Patrin observed in Siberia many mountains 
 entirely composed of siderite, and containing 
 masses or veins of granite ; while reciprocally 
 the mountains of granite often present veins and 
 masses of siderite f. These accidents are parti- 
 cularly frequent in that part of the Altaian 
 mountains which approaches the river Irtish. 
 
 It also abounds in Bohemia, Saxony, Tyrol, 
 and many other countries, not to mention the 
 isles of Arran, Col, and Tirey; the district be- 
 tween Lochlomond and Dunkeld, and other parts 
 of the Highlands of Scotland ; and also near 
 Holyhead in Wales. 
 
 Saussure describes, 674, a strange mixture 
 of massive granite with a grey heavy rock, which 
 
 * Kirwan Geol. Ess. p. 181. 
 f Min. i. 127. 
 
MODE I. SIDERITE. 
 
 on the outside appeared of a rust-colour. This 
 is evidently a siderite, of which the iron is de- 
 composed. Fie justly observes, that both must 
 have crystallised together, and of course siderite 
 must be as ancient as granite*. 
 
 The rocks of siderite are by Werner classed 
 among the Primitive Traps, which he divides into 
 the common, the granular, and the schistose; 
 with two mixtures, siderite with felspar and with 
 mica. The admixtion of mica and pyrites is 
 by Daubuisson regarded as characteristic of the 
 primary traps. That of siderite and felspar Primitive trap, 
 constitutes the primitive grunstein of Werner, 
 including the common, the porphyritic, the 
 grunstein porphyry, the green porphyry of the 
 ancients, and grunstein slate ; which latter has, 
 according to Daubuisson, been called horn- 
 schiefer. Some of these primitive traps have 
 been arranged under the large and vague deno- 
 mination of corneennc, roche de corne, pierre de 
 Cornell by the French mineralogists; and even 
 by Saussure, who tells us, 1223, that when the 
 corneenne, or pierre de corne, has marks of crys- 
 tallisation, it assumes the name of hornblende. 
 But as the stones, confessedly called basalts by 
 
 * The summit of the Dome du Goute" consists of siderite in a 
 state of decomposition. Id. 1Q80. 
 f La pierre comic is petrosilex. 
 
DOMAIN I. SIDEROUS. 
 
 the ancients, often present marks of crystal- 
 lisation, being sideritic rocks or primitive traps, 
 they shall be considered /under that division. 
 Wad, in his account of the Egyptian minerals in 
 the Borgian Museum*, observes, that the ba- 
 Ancient basalt, saltic monuments of the ancients are referable 
 to two classes; 1. The primitive, consisting of 
 black hornblende, or siderite, which is some-* 
 times so mingled with veins of felspar, and often 
 with quartz and felspar, partly rude partly crys- 
 tallised, that it is in some examples difficult to 
 determine whether they should be placed among 
 the basalts, or syenites, of Werner. 2. This 
 class appears of more recent formation, and in 
 all respects agrees with the basalt of Werner, 
 except that it be more hard, owing to the inter- 
 spersion of minute particles of quartz, being 
 very similar to the stone with which the ancient 
 Roman ways were paved, and which is by some 
 called lava. Some of the ancient basalts there- 
 fore cannot be distinguished from siderites, as 
 the ancients were not conversant in the minute 
 discriminations of modern science : and some 
 monuments which they would have called ba- 
 salts, a modern mineralogist would rank among 
 the black granites. But as the ancients cannot 
 be our guides in mineralogy, a science to them 
 
 * Fossilia 5igyptiaca Musei Borgiani. Felitris, 1794, 4to. p. 7 
 
MODE I. S1DERITE. 
 
 utterly unknown, it is sufficient to say, that the 
 rocks which the acute Werner, and his disciples, 
 have classed under HORNBLENDE, here appear 
 under SIDERITE, and some of their TRAPS under 
 BASALT; while the trap of the Swedes, with a 
 fine grain, is here called BASALTIN. The dif- 
 ference indeed is rather in the transition ; the 
 chemical analysis of siderite and basalt being 
 nearly the same. 
 
 SIDERITE. BASALT. 
 
 Silex 37 Silex 50 
 
 Argil 22 Argil 15 
 
 Magnesia 16 Magnesia 2 
 
 Lime 2 Lime 8 
 
 Oxyd of iron ... 23 Iron 25 
 
 100 100 
 
 It scarcely needs to be observed, that in all 
 substances the proportion of ingredients varies 
 according to circumstances. 
 
 In general therefore where the substance has 
 a crystallised and silky appearance, it must be 
 classed among the siderites ; but when it wears 
 a dull or earthy aspect, it belongs to the basalts, 
 though in the latter shining crystals of siderite 
 may be interspersed. 
 
 When mica alone is found in a substance, it 
 cannot alter the denomination, for, as Mr. Kir- 
 wan has observed, there is scarcely a mineral in 
 
10 
 
 DOMAIN I. SIDEROUS. 
 
 which it may not be found. But the mixture of 
 siderite with felspar deserves a distinct appel- 
 
 Grunstein. lation. The term grunstein or green stone, used 
 by Werner, has been deservedly ridiculed, as 
 alike vague and barbarous. He borrowed it 
 from the Swedes, whose grunstein was really 
 green. It is further objectionable, as he extends 
 it to green porphyry, and other mixtures of 
 earthy trap or basaltin. As many new appel- 
 lations are wanted, to distinguish with brevity 
 and precision the different kinds of rocks, it is 
 
 Waiierite. proposed to call this mixture WALLERITE, in 
 honour of Wallerius, the great Swedish father 
 of mineralogy. The other kinds of grunstein 
 are arranged after basalt; as by their earthy 
 texture they differ greatly from the former : nor 
 can the black and green porphyry of the an- 
 cients, classed by Werner under this head, be 
 considered as having any other basis than com- 
 mon trap. 
 
 STRUCTURE I. COMMON SIDERITE. 
 
 Aspect 1. Uniform. Black siderite of Egypt. 
 This substance is more generally found mingled 
 with granite ; but scarabcei and other small sculp- 
 tures sometimes occur in it, and sometimes in that 
 ore of iron called hematites*. 
 
 * See Wad, p. 8 and 32. 
 
MODE I. SIDERITE. 
 
 Black siderite from Mount Sinai. Given to the 
 author by Roziere, a skilful mineralogist, who 
 accompanied the French expedition. 
 
 Compact siderite, from the isle of Col, Scot- 
 land. 
 
 The same, from the iron-mines of Sweden. 
 
 The same, of a brownish and grey colour, from 
 Finland. 
 
 Green siderite, from Sweden. 
 
 Saussure mentions, 1824, beautiful beds of 
 black siderite, in one of which an excavation had 
 been made to extract crystal. 
 
 Aspect 2. Mingled. Black siderite, with mi- 
 ca, from Egypt. 
 
 The same, with olivine, from Egypt. 
 
 The same, with gold and silver, or with elec- 
 trum, a natural mixture of these two metals, from 
 Kongsberg in Norway. 
 
 Green siderite, with garnets, from Sweden. 
 
 The same, intermixed with iron ore, from Salz- 
 burg. 
 
 The same, with hard clay, from Vesuvius. 
 
 The same, with pyrites, from Arindal in Nor- 
 way. 
 
 The same, from Salberg in Sweden. 
 
 The same, from the iron-mines of Dognaska, in 
 the Bannat of Hungary. 
 
DOMAIN I. SIDEROUS. 
 
 The detached crystals of siderite, and what is 
 called Labradore hornblende, or schillerspar, if 
 it be not another substance, are properly topics of 
 gemmology, or lithology, and not of petralogy, 
 as they never occur in the form of rocks. It may 
 be proper to observe, that siderite is called by 
 many French writers schorl en masse, and some- 
 times schorl spathique. 
 
 The real grunstein of the Swedes is a mixture 
 of siderite and mica, sometimes with particles of 
 quartz*. 
 
 Fine grained siderite, with mica, from Upland. 
 
 The same, large grained, with quartz, from 
 Smoland. 
 
 The same, with spots of steatite, from Taxas in 
 Smoland. 
 
 STRUCTURE II. SCHISTOSE SIDERITE. 
 
 This substance, the hornblende slate of the Ger- 
 mans, is often found in gneiss, as already men- 
 tioned; but it is often joined with compact si- 
 derite ; and, with a greater mixture of magnesia, 
 passes into chlorite slate : for between siderite, 
 chlorite, and actinote, there is a near connexion ; 
 whence Saussure argued that chlorite is merely 
 
 * Wall. i. 436. , Whence it appears that it was also called 
 Binda and Jernlinda : the Saxum ferreum of our author. 
 
MODE I. SIDERITE. 
 
 the earth of green hornblende. Compact and slaty 
 siderite also frequently occurs, in large masses, in 
 common slate, a kindred rock. 
 
 Aspect 1. Uniform. Schistose siderite, of a 
 beautiful silky texture, from Kongsberg in Nor- 
 way. 
 
 Schistose siderite, from Holy head. 
 
 The same, delicately waved, from Norway and 
 the Highlands of Scotland. 
 
 Aspect 2. Mingled. Schistose siderite, with 
 garnets, from Kongsberg. 
 
 The same, with native gold and silver, from 
 the same. 
 
 The same, with particles of quartz, from Saxony. 
 
 Schistose siderite in divergent rays, sometimes 
 of a fascicular sometimes of a starry form, from 
 the Alps, where it is often imbedded in granular 
 felspar. This rock will seldom admit of a polish, 
 otherwise it might rival the Miagite, the arborescent 
 granitel found in the ruins of Rome, and other 
 splendid and celebrated mixtures of felspar and 
 siderite, which are here classed amongst the ANO- 
 MALOUS ROCKS. 
 
 Saussure describes different kinds of schistose 
 siderite in the following terms : 
 
 " The schistus composed of hornblende and 
 
DOMAIN I. SIDEROUS. 
 
 felspar is very common upon the banks of 
 Isere, and this is not extraordinary, as there are 
 even entire mountains of it in Dauphiny, which I 
 have myself seen. The famous silver mine of 
 Challenches, into which I descended, is in a moun- 
 tain of this kind. The varieties of this rock are 
 extremely numerous ; we find it with leaves sin- 
 gularly distorted, or bent in zigzag. It sometimes 
 occurs with thick leaves, and at others as thin as 
 paper. In some varieties, the leaves of pure and 
 coloured hornblende, alternate with leaves of white 
 and pure felspar ; in others, these two substances 
 are almost confounded; in others, in short, the 
 leaves are interrupted either suddenly or by gra- 
 dations. There are also frequently found knots 
 or detached pieces of white felspar, confusedly 
 crystallised, and often mixed with quartzose parts. 
 It is 'curious to observe, when these knots are of 
 irregular shapes, the exactness with which the 
 schistose leaves follow all the convolutions of the 
 knots, and form a kind of fortifications around 
 them. 
 
 " The hornblende varies in its colour; some- 
 times black and brilliant, sometimes inclining to 
 green, at others brown or grey ; its form some- 
 times presents pretty regular crystals, especially 
 in schisti, whose leaves are straight ; and at other 
 times thin plates, almost as brilliant as mica. 
 
MODE I. SIDERITE. |5 
 
 without any appearance of a regular form. It is 
 likewise more or less fusible under the blow-pipe. 
 
 " The felspar also varies by its white colour 
 more or less pure, and inclining sometimes to 
 a green or rosy hue ; and by its form which, at 
 one time, presents pretty regular rhomboidal la- 
 minae, at others a crystallisation quite confused 
 in small granular masses, like statuary marble. 
 There is sometimes seen in the leaves, as in the 
 knots, a mixture of a little quartz. The felspar 
 which enters into the composition of this schistus 
 is commonly of that kind which I have termed 
 feldspath sec, or dry felspar ; I have however seen 
 but only one piece, of which the felspar was gras, 
 or unctuous." 1586, 
 
 He also mentions 
 
 2227. A green rock, which he would formerly 
 have called roche de corne, but must now refer to 
 the hornblende slate of Werner : and, 
 
 1971. A gneiss, composed of laminar siderite 
 and felspar, on the ascent of Mont Blanc. 
 
 2271. A slate of fine scales of mica and horn- 
 blende, sometimes in level plates, sometimes un- 
 dulated. It is of an olive-green colour, acts faintly 
 upon the magnet, and makes a hasty effervescence 
 with acids; a proof that it contains some cal- 
 careous particles. 
 
 2131. Near Macugnaga, brilliant hornblende 
 
DOMAIN 1. SIDEROUS. 
 
 slate, in large redoubled layers, so as to form 
 masses three or four inches in thickness, enchased 
 in dull white quartz. 
 
 J 822. Beautiful rocks of granular felspar, 
 with long irregular crystals of siderite, which 
 sometimes assume the form of sheaves or di- 
 verging rays. The base of granular felspar has 
 been mistaken for a sandstone. 
 
 2144. Sheaves of black hornblende, two or 
 three inches in diameter, forming a most beautiful 
 effect on a white gneiss. 
 
 164. Siderite, in the form of a sheaf, or rather 
 fan, on granular quartz, or rather felspar. 
 
 1954. Siderite mixed with calcareous parti- 
 cles, ramifying alternately with quartz. 
 
 STRUCTURE III. WALLERITE. 
 Wallerite. 
 
 This rock, as already mentioned, is one of the 
 primitive gruns terns of Werner, but is here re- 
 stricted to a mixture of crystalline siderite with 
 felspar ; the other primitive grunsteins being class- 
 ed after the basalts, to which they more strictly 
 belong. 
 
 Wallerite from Sweden, of black crystalline 
 siderite mixed with felspar. 
 
 The same, greenish black, from Snowdon in 
 Wales. 
 
 The same, from Mount Sinai. 
 
DOMAIN I. SIDEROUS. 17 
 
 MODE II. BASALT. 
 
 Texture coarse, generally mixed with grains Characters, 
 of quartz or felspar ; it has sometimes a crys- 
 talline appearance, hut the crystals are minute, 
 so that it appears earthy. 
 
 Hardness basaltic. Fracture rather even. 
 Fragments rather sharp. 
 
 Weight siderose. 
 
 Lustre shining. Opake. 
 
 Colour iron grey, sometimes greenish. 
 
 This celebrated substance is one of the traps, 
 or rather a grunstein> of the Swedes and Ger- 
 mans; and is by the Wernerian school con- 
 sidered as of three remote formations, the pri- Formations. 
 mitive, transitive; and stratiform, also called 
 Jloetz, or horizontal. 
 
 The basaltic monuments of the ancients are Basalt proper, 
 allowed by Dolomieu and Faujas, two chief 
 supporters of the Volcanic sj^stem, not to be of 
 a volcanic nature ; and of course the restriction 
 of the name to pretended compact lavas is not 
 only objectionable, but highly absurd, as trans- 
 ferring a well-known term to a substance widely 
 different. Compact lava is so uncommon a sub- 
 stance, that there was no specimen of it in the 
 great collection of prince Biscari, at Catania $ 
 
 VOL. i. c 
 
.DOMAIN 2. 
 
 while Gioeni and other writers on volcanoes 
 say, that very seldom a piece without pores can 
 be found, even of a few inches in diameter. A 
 specimen of compact lava in the British Museum 
 contains melted garnets ; and is of such an ap- 
 pearance that no eye can confound it with basalt, 
 even of the finest texture: yetFaujas, and other 
 late French writers, persist in restricting the 
 term basalt to a supposed lava, while they use 
 the term trap for the real basalt of the ancients ; 
 which, even by their own volcanic theory, is of 
 quite a different nature and origin*. 
 
 In his description of the Borgian monuments,. 
 as already mentioned, Wad found that those of 
 basalt might chiefly be referred to siderite or 
 hornblende : and it is remarkable that the word 
 basaltes, according to Pliny, signified iron in the 
 Ethiopic language, as sideros does in the Greek. 
 The basalts of the ancients are often siderites, 
 sometimes with veins or grains of felspar or 
 quartz ; sometimes with olivine : the only an- 
 tique specimen in which leucite occurs having, 
 as Wad observes, been sculptured at Rome. 
 
 Some small Egyptian monuments, however, 
 occur j n ji ne basalt, here called basaltin : to 
 
 * The name lasalt seems subject to a singular fatality of abuse, 
 the grave Wallerius having, with equal skill, degraded it to com- 
 mon schorl ' 
 
MODE II. BASALT. JO, 
 
 which last division the basalt or trap of the 
 moderns, and pretended lava of the French mi- 
 neralogists, properly belongs. For the basalt of 
 Agricola, the trap of Wallerius and Werner, a 
 substance abundant in the Faroe isles*, Sweden, 
 Scotland, Ireland, Saxony, Auvergne, Sicily, &c. 
 may also be traced among the Egyptian and 
 other ancient monuments ; and as Pliny informs 
 us that the name of iron-stone was given on 
 account of its colour and hardness, this appel- 
 lation must have been yet more applicable to 
 fine-grained trap than to siderite, which is of a 
 looser grain and softer cohesion. And while the 
 ancient denominations are so indistinct that they 
 have included green fluor, and the fine green 
 granite of Abyssinia, among the emeralds f, it is 
 easily conceivable that the term basalt was ex- 
 tended to two or three distinct rocks, of a colour 
 and hardness approaching to iron : but even the 
 basaltin, or fine-grained basalt of the ancients, is 
 frequently interspersed with minute grains of 
 quartz or felspar; and monuments of what we 
 would strictly call trap or basalt are compara- 
 tively rare. But as it is evident that the basalt 
 
 * In the north of Europe. This spelling distinguishes them 
 from Ferro, one of the Canaries. 
 
 t There seems little doubt that the pillars said to be of emerald 
 :re of this substance. 
 
 C 2 
 
DOMAIN I. SIDEROUS. 
 
 6f the ancients was more commonly of a coarse 
 grain, and often intermixed with quartz or fel- 
 spar, it has been thought proper, for the sake of 
 precision, to confine the term to that substance ; 
 while the name basal tin is applied to the fine- 
 grained basalt of the moderns, which frequently 
 assumes the columnar form, in which shape also 
 the former sometimes occurs. There is no doubt, 
 for example, that some of the whins of the Scot- 
 ish mineralogists, in which grains of quartz or 
 felspar are mixed with trap, strictly and properly 
 belong to the basalts of the ancients. 
 
 The dispute therefore concerning the Nep- 
 tunian or the Volcanic origin of this substance 
 must more aptly be considered as having no 
 concern with the proper BASALT of the ancients, 
 but with the modern basalt, here called basaltin. 
 The author of this work is not attached to any 
 theory, nor does he believe that the facts and 
 observations are yet sufficiently numerous to 
 afford even the semblance of a plausible conca- 
 tenation j but he may be allowed to observe, that 
 though volcanoes are often situated in basaltic 
 countries, as they of course abound with iron, of 
 itself inflammable, and yet more with sulphur, 
 and probably forming the great source of vol- 
 canic fires ; yet, as there is no proof of any vol- 
 cano, however vast and powerful, as Etna, or 
 
MODE II. BASALT. 
 
 some of those in the Andes, having in any anr 
 cient or modern eruption furnished basalt, either 
 in columns or in strata, it would seem an infal- 
 lible inference that this substance cannot be of 
 volcanic origin*. The wide extent also of this 
 substance, and the common situation of basaltic 
 columns on the summits of hills, strongly mili- 
 tate agains.t this idea. The same formation of 
 basaltic columns resting sometimes on amor- 
 phous basalt, sometimes on indurated clay tinged 
 with red ochre f of iron, is found to extend near 
 thirty miles into Ireland from the Giants' Causy, 
 and as far as the northern Faroe isles, a space 
 of more than six degrees, or three hundred 
 and sixty geographical miles ; and, it is worth 
 remarking, nearly in the same meridian. In 
 like manner the basalt of Saxony might be said 
 by a theorist to extend through Sweden, even to 
 Spitzbergen; and it is observable that all the 
 northern parts of Europe abound with iron ; 
 those of Asia are concealed by perpetual ice, 
 snow, and marshes; while those of America 
 
 * None of the numerous hills around Etna is capped with 
 basalt ; nor have the isles ejected by submarine volcanoes presented 
 that substance; so there is no proof of a subaqueous origin. The 
 .prisms on the shore around Etna are very rude, and unlike the 
 beauty and exactness of basaltic columns. 
 
 t Does the red colour indicate heat, as yellow ochre thus asr 
 /sumes that tinge ? 
 
DOMAIN I. 
 
 seem chiefly to present copper. The basaltic 
 columns of Germany, as is well known, are 
 chiefly situated on the tops of hills ; and, from 
 Landt's recent interesting description of the Fa- 
 roe isles, it appears that this phenomenon is 
 there equally common. A magnificent example 
 occurs in the isle of Osteroe. 
 
 " To the north of the village of Zellatrae there 
 B Faroe f ls a Dasa M c hill, which extends more than a 
 mile northwards: properly speaking, it forms 
 the bottom of two hills, which lie behind it, 
 namely Halgafieldstinden and Rodefieldstinden, 
 which are of considerable height, and about two 
 miles distant from each other. The basaltic hill 
 itself is about four hundred and twenty feet high, 
 and consists of strata of pentagonal and octa- 
 gonal basaltic columns, placed close to each 
 other in a perpendicular direction, and in such 
 a manner that the tops only of the farther co- 
 lumns are seen, while those in front exhibit their 
 whole form, but appear to be different in length. 
 These columns, which rest on a foundation of 
 trap about three hundred feet in height, are the 
 largest of the kind in the Faroe islands; for where 
 the rock has been freed from mould, these co- 
 lossal pillars may be seen with their lower ends 
 standing on another species of stone, and rising 
 to the height of above a hundred feet, all equal 
 
MODE "**. BASALT. 23 
 
 in size, being about six feet in diameter. Many 
 of these huge columns, which have fallen down, 
 are now lying at the bottom of the hill; one in 
 particular, sixty feet in length, has been thrown 
 across a deep gulley, with its ends resting on 
 each side, so as to form a bridge over it*." 
 
 It also appears from Dr. Richardson's recent 
 observations f, that the basalt in the north of 
 Ireland occurs on the tops of hills, at a great 
 distance, while the intervening space has been, 
 as it were, scooped out by some exterior agency, 
 with which we are at present totally unacquaint- 
 ed. But whether some comet has approached 
 the earth, or some small planet, like one of those 
 recently discovered, has fallen into it, and occa- 
 sioned appearances altogether inexplicable upon 
 our small scale of observation, most probably 
 may ever remain a matter of theory +: and in 
 natural, as well as in civil history, there are 
 many objects of which the best judges choose to 
 remain in what Mr. Gibbon emphatically calls 
 
 A LEARNED IGNORANCE. Nor ITlUSt it be for- 
 
 gotten, that masses of sandstone and limestone 
 
 * Landt, 39. 
 
 t Ph. Tr. 1803. 
 
 J Dolomieu, J. de Ph. 1 791, p. 385, thinks that an exterior 
 shock has broken the crust oi' the globe, and raised parts on others. 
 The like ideas may be inferred from the REFOULEMENT of Saussure 
 
DOMAIN I. SIDEROUS. 
 
 are, in like manner, found upon the summits of 
 hills, quite detached from the original beds to 
 which they would seem to belong by the identity 
 of their substance. From these remarks it must 
 appear to every impartial mind, that the pheno- 
 mena of basalt are on too vast a scale, and of an 
 appearance toTo uncommon, to be produced even 
 by a chain of volcanoes, of which the Andes 
 present most extensive examples; so that to 
 confine the appellation of basalt, with the French 
 mineralogists, exclusively to a pretended com- 
 pact lava, would be a mere assumption, alike 
 foreign to ancient erudition, and the precision of 
 modern science. 
 
 STRUCTURE I. AMORPHOUS BASALT*. 
 
 Egyptian. Basalt of a greyish black, with very small grains 
 of white quartz, and spots of iron ochre, from 
 
 Egyptf. 
 
 Basalt of a blueish grey, glimmering lustre, and 
 fasciculated fracture, from the same. 
 
 * It is always of a mingled aspect. 
 
 f It is only to be inferred that the Egyptian basalts do not belong 
 to the columnar. Ferber erroneously says, that Strabo mentions 
 the Ethiopic basalt as columnar. That author, lib. 17, describes a 
 pyramid, partly built of basalt, from the extreme mountains of 
 Abyssinia. 
 
MODE II. BASALT. 
 
 With a mixture of amorphous black siderite, 
 and minute grains of white quartz, from the same. 
 
 The same interspersed with transparent felspar, 
 which becomes greenish from the mixture, from 
 the same. 
 
 Greyish black basalt, interspersed with black 
 siderite, partly amorphous partly crystallised, and 
 with greyish white felspar. 
 
 The same, with black siderite, and small grains 
 of yellowish green olivine. 
 
 The same, with black siderite, partly amorphous 
 partly crystallised, olive-green olivine, and scat- 
 tered particles of black mica. 
 
 The same, superficially spotted with reddish 
 brown, probably from the decomposition of the 
 iron. 
 
 Greyish black basalt, interspersed with crystal- 
 lised siderite, with small crystals of olivine in 
 square prisms, of which some being decomposed, 
 the surface becomes porous, while the interior is 
 completely dense *. 
 
 Such is the catalogue of ancient basalts observed 
 by Wad in the Borgian museum, there not being 
 even one example of basaltin, though it certainly 
 occurs in small Egyptian monuments; and the 
 author saw at Paris the statues of a king and 
 
 * Such basalts have deceived the volcanists. 
 
DOMAIN I. S1DEROUS. 
 
 queen sitting, in one piece about nine inches in 
 height, the back and sides being covered with 
 hieroglyphics. He also saw in the same collection 
 small fragments of green basaltin, from Egypt. 
 
 Patrin gives the following list of ancient ba- 
 salts*. 
 
 oriental. " Oriental basalt of a blackish grey, of a fine 
 grain, mixed with white scales of felspar, and little 
 veins of quartz. This is the kind most commonly 
 observed in ancient monuments. 
 
 " Oriental black basalt. It is mixed with grains 
 of quartz, with small crystals of felspar, and with 
 spangles of mica ; these ingredients are not com- 
 bined as in granite, but interspersed in the black 
 base of trap. The Isis, which is in the court of 
 the Capitol, is of this stone. 
 
 " Oriental black basalt, radiated with veins of 
 red granite, in small grains. The two sphinxes, 
 which are at the foot of the great stair-case of the 
 Capitol, are of this basalt. 
 
 " Oriental black basalt, with green spots of si- 
 derite. It is called at Rome Egyptian stone, or 
 nephritic stone. 
 
 " Oriental green basalt. It is of the same base 
 as green porphyry : the only difference is, that the 
 
 * i. 127. The French authors rarely quote their authorities; but 
 Patrin has borrowed his examples from Ferber's Travels in Italy. 
 
MODE If. BASALT. 27 
 
 substance of felspar is equally interspersed in it, 
 and is not united in crystals. This base is homo- 
 geneous, very compact, and very hard. Fine 
 statues of it are seen in the Capitol, and in the 
 Villa Albani. 
 
 " Oriental green basalt, with white specks. It is 
 the same as the preceding, in which the felspar is 
 united in small crystals : it is named speckled ba- 
 salt, and is very rare. There are two pillars of it 
 at Rome, in the church of St. Pudentiana. 
 
 " Dolomieu says, that there is such a vast 
 number of Egyptian monuments in the Borgian 
 Museum at Veletri, that they are almost sufficient 
 to constitute the whole Egyptian Lithology : many 
 are formed of stones which have qualities attri- 
 buted to basalts ; not one is volcanic." 
 
 In passing to the modern basalts, it must be 
 premised that the trap of Wallerius, which he de- 
 scribes as being of an impalpably fine grain, 
 belongs solely to the basalt of the moderns, here 
 called basal tin from that circumstance. But the 
 basaltic granite of this venerable author * certainly 
 includes some of the basalts of the ancients ; as 
 that of an iron-colour, mixed with the ore of that 
 metal and quartz, which is found at Norberg, in 
 Westmania, His saxum fcrreum, composed of 
 
 i. 422. 
 
28 DOMAIN I. SIDEROUS. 
 
 various mixtures of siderite, mica, basalt, and 
 quartz, may also sometimes be referred to this 
 Mode*. 
 
 Basalt, with mica, from Upland in Sweden. 
 
 Green basalt, with black mica, and sometimes 
 a mixture of quartz, from Westmania, 
 
 The basaltin of Kirwan is merely crystallised 
 hornblende, or siderite ; but the basaltin of Baron 
 de Born is often the real basalt of the ancients, 
 whjle his basalt is here called basaltin. He men^ 
 tions that kind, mingled with green siderite and 
 olivine, from Bohemia; and that mingled with 
 brown mica, from the same country. In his 
 treatise on traps, Faujas confines himself to the 
 basaltins, or fine-grained basalts ; he mentions a 
 trap, sometimes black sometimes green, with grains 
 of semitransparent quartz, from Scotland and Pro- 
 vence, which may probably be classed among the 
 ancient basalts f. The pillars of grunstein, which 
 compose the innermost circle at Stonehenge, may 
 also belong to this division J. 
 
 * i. 437- 
 
 f* Launay, Essai sur les Roches, 64, mentions a mixture of trap 
 and felspar, from the isle of Bornholm, Denmark. 
 
 J Townson's Tracts ; whence may also be added the whin of 
 Salisbury Craigs, near Edinburgh, containing siderite and felspar. 
 
MODE II. BASALT, 
 
 STRUCTURE II. COLUMNAR. 
 
 The following passage of Strabo has beeri 
 thought to imply columnar basalt : 
 
 " We went to Philoe from Syene in a carriage^ 
 through a level plain, the space of a hundred sta- 
 dia. Along almost all the route were to be seen, 
 on both sides, in many places, as it were terms*, 
 of a hard, round, and polished stone, almost spheri- 
 cal, and of which mortars are commonly made, 
 placed upon a larger stone, and surmounted by 
 another. Some even lay apart ; the largest being 
 not less than twelve feet in diameter, and the 
 : others about half as large f." 
 
 Several authors have inferred from this passage 
 that Strabo means to speak of columnar basalt, 
 but he would rather seem to imply a work of art, 
 a magnificent avenue from Ethiopia into Egypt. 
 No basaltic columns have been observed twelve 
 feet in diameter ; and even if the passage be cor- 
 rupt, and twelve feet in height be intended, or 
 perhaps two feet in diameter, it would still remain 
 so obscure, that it would be adventurous to build 
 any solid argument upon such an uncertain found- 
 
 * The little hermetic columns at Athens, 
 t Strabo, lib. 17. 
 
DOMAIN I. SJDEROUS. 
 
 ation. It is singular that Denon, who has given 
 such a minute and interesting account of the isle 
 of Philoe, should have taken no notice of these 
 remarkable monuments. He speaks indeed of 
 large blocks of stone covered with hieroglyphics, 
 but mentions nothing but granite in that quarter ; 
 and basalt could scarcely have escaped the atten- 
 tion of a French traveller. 
 
 The columnar form is far more commonly as- 
 sumed by the basaltin, than by the real ancient ba- 
 salt : yet it is found even among other substances. 
 
 " Columns of porphyry are not rare; and, among 
 other places, are found near Dresden, several feet 
 in length, and not more than two inches in diame- 
 ter*. Columns of petrosilex compose a large 
 portion of a mountain near Conistone lake. Very 
 perfect quadrangular prisms of argillaceous schis- 
 tus are found near Llanurst Rubble slate as- 
 sumes the columnar form at Barmouth. The 
 limestone near Cyfartha, in Glamorganshire, is 
 divided into very regular acute rhomboidal prisms : 
 even the sandstone of the same district is not 
 unfrequently columnar; and one of the beds of 
 gypsum at Montmartre is distinctly divided into 
 pretty regular columns. Sandstone, clay, argil- 
 
 * Strange's granitic columns, near Verona, are jwrphyritic, with 
 a paste or basis. Spallanzani. 
 
MODE II. BASALT. 3J 
 
 laceous iron ore, and many other substances, be- 
 come prismatic by torrefaction ; and the prisms of 
 starch formed in drying, have often been consi- 
 dered as illustrative of basaltic formations*.'' 
 
 Among the numerous examples of columnar 
 basaltin, it is well known that they often oc- 
 cur of a coarser grain, and mixed with felspar 
 and siderite, thus strictly belonging to the basalt 
 of the ancients. The columns in the north of 
 Italy, supposed to be volcanic, seem chiefly to 
 consist of this substance. I do not however find 
 that the German mineralogists mention their grun- 
 stein, as occurring in a columnar form, though 
 Daubuisson has evinced that grunstein and basalt 
 are the same substance. The analysis of Dr. 
 Kennedy is as follows : 
 
 BASALT. GRUNSTEIN. 
 
 Silex 46 46 
 
 Argil . .... 16 19 
 
 Lime 9 8 
 
 Oxydofiron ... 16 17 
 Water and volatile matter 5 4 
 
 Soda 4 3% 
 
 Muriatic acid ... 1 1 
 
 Loss ...... 3 1| 
 
 100 100 
 
 * Watt, Ph. Tr. 1804. 
 
;<2 DOMAIN I. SIDEROUS. 
 
 It would indeed be a singularity that, while 
 basaltin occurs so often in a columnar form, a 
 substance composed of the same ingredients should 
 never assume that appearance. Yet perhaps the 
 columnar form of basaltin may itself be partly 
 owing to the impalpable fineness of the ingredients 
 allowing an exact scission, or crystallisation, which 
 coarser materials would not admit; as crystals 
 are generally composed of finer ingredients than 
 amorphous substances. 
 
 * 
 
 MODE III. BASALTIN. 
 
 Characters. Texture finely and almost impalpably granu- 
 lar, sometimes vesicular ; on a large scale strati- 
 fied, rising like successive steps, whence the 
 Swedish name trap. It sometimes presents dis- 
 tinct concretions, of a finer or of a coarser grain. 
 It seems to split in rhomboids, while the colum- 
 nar sometimes lapses into globular forms *. 
 
 Hardness basaltic, or between marble and fel- 
 spar, about 800 of the scale of Quist. Fracture 
 sometimes even, sometimes conchoidal. Frag- 
 ments amorphous > not very sharp. 
 
 Weight siderose. 
 
 * Mr. Watt, Ph. Tr. 1804, observes, that raelted basalt passes 
 into globules, before it assumes the compact texture. 
 
MODE Hi. BASALTS. 
 
 Lustre dull, except when mixed with siderite. 
 Opake. 
 
 Colour greyish black, greenish, rarely brown 
 Or reddish. 
 
 This is the basalt, or fine-grained trap, of the 
 moderns. Karsten has supposed that even the 
 finest basalt is a mixture of impalpable grains of 
 siderite and felspar, or quartz; which would in- 
 deed appear to be confirmed by the identity of 
 the chemical constituents. Faujas also argues 
 in favour of his volcanic theory of basalt, that 
 trap, which he allows not to be of a volcanic 
 nature, is merely a granite of a very fine grain. 
 This idea partly rose from the confused and lax 
 manner in which the term granite has been hi- 
 therto used ; and partly from his theory that 
 real basalt is always a lava. But in this way alf 
 the mixed rocks might be classed under granites $ 
 for there is scarcely a mixture which has not 
 been arranged under that head by some mi- 
 neralogist, as the reader may perceive from the 
 edition of Linnaeus by Gmelin. It is true that 
 a mixture of siderite felspar and quartz would 
 form a genuine granite, and that some of the 
 ; basalts of the ancients might be classed, as Wad 
 has observed, among the granitels : but where 
 the siderite so preponderates as to give a great 
 prevalence to its colour; and especially where 
 
 VOL. I. l D 
 
34; DOMAIN I. SIDEROUS. 
 
 the particles are earthy instead of being crystal- 
 lised, as in granite, where the silicious part super- 
 abounds ; a wide difference has always been al- 
 lowed. A variation of the same ingredients will 
 indeed ever form one of the chief distinctions in 
 mineralogy; for it must be repeated, that it is 
 not the ingredients, but the mode of their com- 
 bination, which forms the chief distinction : dia- 
 mond being akin to coal ; sapphire only con- 
 sisting of clay and rust ; and, among the argil- 
 laceous and magnesian rocks, silex is commonly 
 the predominating ingredient, but still the argil 
 and magnesia give the character and name. 
 
 But let us listen to the great master of petra- 
 logy on this interesting topic. 
 
 " ^ ca ^ t ra P> a roc k composed of small grains 
 of different qualities, confusedly crystallised, in- 
 closed in a cement, and sometimes also united 
 together without any distinct cement ; and with 
 no perceptible regular crystals, except rareljr 
 and accidentally. 
 
 " This definition connects traps with granites, 
 and porphyries ; but M. Dolomieu has made it 
 very evident that this approximation already 
 exists in nature. He observed at Rome, in the 
 masses of granite and porphyry selected and 
 worked by the ancients, as we observe it in ou| 
 Alps, and in the blocks that are detached from 
 
MODE III. BASALTItf. 5 
 
 them, varied transitions between these different 
 kinds. 
 
 " I think besides that, in the nomenclature of 
 mineralogy, it must be regarded as a principle, to 
 determine the kinds and species, from individuals 
 whose characters are the most striking ; and to 
 mark the transitions of doubtful and ill-defined 
 substances: for the principle established in bo- 
 tany, of considering as belonging to the same 
 species, individuals between which we observe 
 intermediate shades, cannot be admitted in mi- 
 neralogy, without reducing all known fossils to 
 one and a single species. Indeed there is none 
 that may not be departed from, to make the tour 
 of the whole chain of those which have already 
 been determined, by almost insensible shades; 
 and the more we shall study mineralogy, the 
 more this truth will become obvious, by the 
 number of varieties and shades that we shall 
 discover. 
 
 " I therefore say, that when two fossils pre- 
 sent remarkable differences, we must not refrain 
 from distinguishing them, and giving them dif- 
 ferent names, under the pretext that we have 
 found intermediate varieties which seem to con- 
 nect them, by appearing to belong equally to 
 the one and the other; without which, I repeat, 
 that we shall no longer distinguish genera nor 
 
 D 2 
 
56 DOMAIN I. 3IDEROU8. 
 
 species; there would be bitt one and the same 
 name for all the mineral kingdom. Thus I dis- 
 tinguish granite from porphyry, porphyry from 
 trap, this from petrosilex, roches de corne, and 
 argillolites, because the well-characterised indi- 
 viduals of these different kinds are evidently 
 distinct; and I do not embarrass myself because 
 there are transitions or intermediate varieties, 
 which I do not exactly know to which kind I 
 ought to refer. 
 
 " I have in this only to regret a deviation 
 from the acceptation that M. Dolomieu has 
 given to the name of trap, in the excellent work 
 he published, Journal de Physique, An 2. Part I. 
 page 257. He had given this name to the cor- 
 neus trapezius of Wallerius, which is a simple 
 stone of the genus corneennes, with a fine and 
 Compact fracture. But I have already observed 
 in another place, that the genus of simple cor- 
 neennes does not require this subdivision, whilst 
 the class of composites or rocks appears inca- 
 pable of avoiding it; and of them the cele- 
 brated Werner has even formed such a class, 
 where, under the head of trapp formazion, he 
 includes grunstein, the amygdaloide, the por- 
 phyrschiefer, and bazalt. 
 
 " I shall also observe, that the Swedes give 
 the name of trap, not only to a simple and com- 
 
MODE III. BASALT1N. 
 
 pact corneenne, but also to composite rocks, or 
 to rocks of which this corneenne forms the ce- 
 ment; it is the saxum trapezium^ Wall. Sp. 220. 
 We may also see the description that M. Nose 
 gives of 31 species of traps which he received 
 from Sweden, Bey tr age, p. 401. seq. M. de 
 Faujas, in his little treatise upon traps, equally 
 gives to this word a very wide acceptation; but 
 it does not seem conformable to the laws of a 
 good nomenclature, to give the same name to 
 substances which belong to different classes,, 
 
 " It is according to these principles that 
 I determined to confine the name of trap to 
 a composite rock, or to the rock of which 
 I have given a definition at the beginning of 
 this paragraph. 
 
 " 1946. The traps forming the cement of dif- 
 ferent variolites of the river Emme, vary in their 
 colours and nature. We see some of them grey, 
 others approaching to green, and others to a 
 violet colour ; they are more or less hard, some 
 containing only in their glands free calcareous 
 parts ; others contain in their paste some which 
 become friable after having remained in the ni- 
 trous acid. Even the cement which unites the 
 grains or small crystals of these traps is for the 
 most part clay, hardened into argillolite, more 
 or less ferruginous. The little grains, I speak 
 
38 DOMAIN 1. SIDEROUJ* 
 
 of those which compose the substance of traps, 
 and not of the large grains or glands which form 
 amygdaloids, these little grains, I say, are of 
 quartz, felspar, sometimes of hornblende, and of 
 that substance I have called granular chusite, 
 1944*." 
 
 volcanoes. According to the present classification, ge- 
 nuine basalt, that of the ancients, must be omit- 
 ted in the dispute between the Neptunists and 
 Volcanists, which only regards basaltin. The 
 common trap of the Swedes and Germans is 
 always a basaltin ; and when stratified is allowed 
 even by Faujas not to be volcanic. The contest 
 therefore chiefly relates to the columnar basaltin* 
 which the French mineralogists infer to be always 
 of a volcanic origin ; while, as already observed, 
 it seems rather to arise from a phenomenon still 
 more grand and rare. The great chain of vol- 
 canoes in the Andes is chiefly argillaceous, or 
 clay porphyry ; and their most dangerous ejec- 
 tions are torrents of mud. In New Spain, where 
 the mountains are chiefly of clay- slate, a vol- 
 
 * Sauss. vii. 203. For the chusite of Saussure, see his Journey 
 to the extinct volcanoes of Brisgaw, Journ. de Ph. 17Q4, p. 325. 
 
 See also his account of pierres de corne, Q5 : most of them may 
 be scratched by the nail. He says, 103, that trap is a compact 
 pierre de corne, which not being a production of fire, is very different 
 from basalt. In 1525, Saussure doubts if the basaltin of the 
 extinct volcano of Beaulieu be volcanic. 
 
MODE III. BASALTIC. 
 
 cano suddenly burst out in the vale of Jorullo, 
 1759; when, according to Humboldt, who saw 
 it in 1803, a basaltic cone appeared above 
 ground, of 1400 feet in height: but this cone 
 seems rather to have been developed than ele- 
 vated by the new volcano, as it could scarcely 
 be formed from fluid lava, which would be con- 
 tradictory to the common laws of hydrostatics. 
 The accounts of the volcanoes in the Andes are 
 far from being complete ; but there seems to be 
 little or no mention of basalt, and no hint of ba- 
 saltic columns ; which, if they were volcanic, 
 would be truly surprising in a chain which ex- 
 tends more than three thousand miles, and con- 
 tains about a hundred active volcanoes. 
 
 But as the presence of iron seems necessary 
 to volcanic inflammation, and the same metal 
 forms the ruling ingredient of basalt, it is no 
 wonder that this coincidence should have occa- 
 sioned a confusion of ideas. Around the grand 
 volcano of the isle of Bourbon, there are basaltic 
 rocks ; and where the basaltin contains sulphur, 
 it may be presumed to be a compact lava ; but 
 here are no ranges of those grand basaltic co- 
 lumns which distinguish Faroe, or Staffa. Jf we 
 return to Europe, the grand volcano of Etna has 
 probably been in a state of conflagration for 
 2500 years, and the circumference is computed 
 
40 DOMAIN I. S1DEROUS. 
 
 to extend to one hundred and thirty miles 5 yet, 
 among the numerous hills which surround this 
 sublime volcano, there is none capped with ba^ 
 saltic columns ; and its lavas, after such nu- 
 merous ejections, do not seem even accidentally 
 to have assumed those elegant and precise forms*. 
 Dolomieu, and other prejudiced Volcanists, have 
 indeed observed instances of the lava divided into 
 rude prisms; but where is the representation 
 of any Giants' Causey in Sicily ? Where the 
 base of Etna reaches the sea on the east the 
 shore is volcanic, or at least supposed to be so, 
 for the space of twenty-three miles ; and for the 
 first seven or eight miles after leaving Catania, 
 Spallanzani indeed observed some prisms, more 
 or less characterised ; but the two other thirds of 
 this shore, though equally consisting of lava, 
 only present irregular fissures. It is presumed 
 that even the former bear but a slight resem- 
 blance to the beautiful articulated columns of 
 Staffa, or the Giants' Causey, especially as 
 figured by Da Costa and Pictet. It is also to be 
 questioned whether these columns of Etna be 
 
 * Von Troll has observed, that basaltic columns are common in 
 Iceland ; but the people suppose their ranges the work of giants, 
 while, if they originated from the volcanoes, the circumstance 
 would strike the most common observer. They sometimes appear 
 among lava, sometimes among tufa ; that is, they are preexistent 
 to either. 
 
MODE III. BASALTIN. 4J 
 
 not composed of porous lava, as Dolomieu allows 
 that some are, while others, as he says, are com- 
 pact, because the water stops the internal effer- 
 vescence; and whether, if the observers had 
 seen the elegant articulated columns of the 
 north of Europe, they would not have rejected 
 the comparison*? But as Sicily may be said to 
 be in our possession, and the interesting work of 
 Dolomieu has not been translated into English, 
 it may not be irrelevant to present an extract, 
 that future observers may decide whether the 
 appearances be caused by the eruptions, or be 
 antecedent to them. 
 
 " As basaltic columns rarely appear in cabi- Basaitinof 
 nets, and it is more interesting to see them on 
 the spot, that their groups may be the better fol- 
 lowed, I shall point out those parts of Etna 
 where the most curious phenomena of this kind 
 may be observed. 
 
 " In the second of the Cyclopic isles, of 
 which the form is that of a Jong pyramid, 
 immense prismatic columns, perpendicular, ar- 
 ticulated, and for the most part hexagonal, ap- 
 pear; the diameter of which is from two to three 
 
 feet. 
 
 i 
 
 * I have seen, in the beautiful collection of M. Patrin, at Paris, 
 berils articulated in the same manner with basaltin : but no one 
 fcas supposed that berils are produced by fire. 
 
42 DOMAIN I. SIDEROUS. 
 
 " In the two other Cyclopic isles there arc 
 smaller columns, heaped upon each other, or 
 inclined in different directions. 
 
 " Upon the shore of la Trezza, near the pier, 
 there is a very curious group of little articulated 
 columns, which radiate from a common centre, 
 and form fasces singularly contorted; the arti- 
 culations are marked, but the vertebrae, so to 
 speak, do not separate. 
 
 " Upon the shore between the castle of laci 
 and la Trezza, there are many groups of ba- 
 saltic columns, piled in various ways. 
 
 " At the foot of the mountain of the castle of 
 laci, there are many groups of pyramidal diver- 
 gent columns. 
 
 " In the body of this mountain there are large 
 bowls, from two to four feet in diameter, like the 
 large balls of pyrites found in chalk, being 
 formed of pyramidal columns united by their 
 points in a common centre. 
 
 " In the mountains of la Trezza is found a 
 great number of prismatic columns, of different 
 forms and dimensions, many being displaced and 
 lying in the clay. 
 
 " At laci Reale, at the bottom of the cliffs on 
 the sea shore, are seen large prismatic columns, 
 subdivided into many smaller; while on the 
 shore there are many large prismatic columns 
 
\ 
 
 MODE III. BASALTIN. 43 
 
 rising from the sea, the tops forming a walk at 
 the bottom of the cliffs. 
 
 " In the mountain of la Motta, two leagues 
 from Catania, there are very large and long 
 prismatic columns, in a vertical position, formed 
 of the most compact lava, which rings like 
 bronze. 
 
 " In the mountain of Paterno there are large 
 columns, ill figured. 
 
 " In the mountains of Licodia, near the spring 
 called Capo del Acqua, there is a wall of large 
 prismatic columns. 
 
 " Under the little town of Bianca Villa there 
 are cliffs formed by prismatic columns. 
 
 " In going from Bianca Villa to Aderno you 
 often walk on the tops of columns, which form 
 regular pavements, resembling the ancient Ro- 
 man ways. Within the town of Aderno there 
 are also several basaltic causeys. 
 
 " Between Aderno and Bronte, on taking the 
 lower road which follows the course of the river, 
 you walk for more than two leagues on a pave- 
 ment formed by the tops of columns ; and on 
 the right are the most beautiful walls of pris- 
 matic basalt which I have ever seen, the co- 
 lumns being mostly vertical. There may also be 
 observed in many places fasces of prisms, pro- 
 jecting from the wall, like epaulements or demi- 
 
DOMAIN I. SIDEROUS. 
 
 bastions. The columns reunited by their sum- 
 mits, as into one head, enlarge according to their 
 length. 
 
 " Scattered prisms and walls of prismatic lavas 
 may also be found in many other places , form- 
 ing, as I have already mentioned, a kind of belt 
 around the skirts of Etna. Don Joseph Gioeni, 
 whom I have formerly celebrated, is occupied 
 with an elaborate description of the prismatic 
 lavas of the volcano -, and he will add prints 
 which can alone express the variety of their 
 forms, and the manner in which they are 
 grouped*/' 
 
 If these representations be exact, they would 
 certainly induce us to believe that prismatic 
 basaltin is the product of volcanic fires; and an 
 admirer of nature would willingly embrace a 
 new and important discovery, which would afford 
 greater variety to his views, and more striking 
 topics for his contemplation. With regard to 
 the British dominions, in particular, a volcano, 
 even extinct, might be regarded as a grand and 
 curious acquisition. The great number of vol- 
 
 * Dolomieu, Etna, p. 455. It must not however be forgotten 
 that, p. 1Q2, he allows that all these columns present small pores, 
 visible by a lens; nay, p. 180, he regards all lavas as compact which 
 contain spaces of some inches without pores. But he might say, 
 as compactness is owing to refrigeration, that, in the cold and moist 
 regions of the north, lavas are more compact. 
 
MODE III. BASALTIN. 45 
 
 canoes which exist, or have existed, in Iceland, 
 the southern skirts of which can alone he said to 
 be known to naturalists, might well authorise us 
 to believe that a chain of volcanoes may have 
 existed in a tract of country, or isles, between 
 the north of Ireland and Faroe, and which have 
 been submerged, the foundations being destroyed 
 by the violence of their own conflagVations, and 
 the fury of the Atlantic ocean. There are 
 indeed, according to Landt, evidences of a vi- 
 treous lava in one of the isles of Faroe; and my 
 intelligent friend Mr. Browne, who has pene- 
 trated so far into Africa, and has pervaded many 
 parts of Asia and Europe, was convinced that 
 he observed a wall of porous lava near Belfast; 
 but still there is no appearance of any craters. 
 Perhaps a disciple of Dolomieu, certainly a great 
 and respected name, " clarum et venerabile no- 
 men" would be contented with one enormous 
 volcano between the north of Ireland and Staffa, 
 and another among the Faroe isles; for the ex- 
 terior chain of the Hebudes is granitic, as are 
 most of the Shetland islands; while the Orkneys 
 consist of argillaceous sand-stone ; and none of 
 them can, on any theory, be said to present vol- 
 canic appearances. 
 
 However this be, as the genuine basalt, that of 
 
46 DOMAIN I. 61DEROUS. 
 
 the ancients, is allowed on all hands not to be 
 of a volcanic nature, the distinct name basaltin 
 becomes the more necessary, in order to discri- 
 minate a wholly different substance, the origin 
 of which is still liable to contestation. 
 
 Concerning basaltin, by many called compact 
 lava, further observations will be found in dis- 
 cussing the Volcanic Rocks. .The testimony of 
 , Daubuisson, concerning the volcanic origin of 
 
 this substance, is too remarkable to be omitted, 
 as in his able treatise on basalt he has strongly 
 enforced the contrary opinion, embraced while 
 he was at Freyberg, and enveloped in the vortex 
 of Werner. This change of his Neptunean ideas 
 occurred after his visit to Auvergne, a country 
 which presents many extinct volcanoes, as all 
 who have seen it or its products must confess ; 
 this curious fact being only denied by those who 
 are lost in the mist of prejudice, and who in fact 
 ruin their own system, by pushing it so far as to 
 maintain tenets palpably absurd, and contradic- 
 tory to the common sense of mankind; such as, 
 for example, that pumice itself is of an aqueous 
 origin ! The following abstract of Daubuisson's 
 remarks on Auvergne is given in the Journal de 
 Physique*. 
 
 * 1804. 
 
MODK III. BASALT1N. 
 
 " After having given a preliminary idea of 
 the topographical position of Auvergne, and the 
 mineralogical structure of this country, M. 
 Daubuisson has successively and in detail de- 
 scribed the volcanoes and basalts of the country 
 of Puy de Dome, Mont Dor*, and of Cantal, he 
 concludes his memoir by a general review of his 
 observations. We shall here give an extract 
 from this latter part. 
 
 " Auvergne (Departments of the Puy de Dome 
 and of Cantal) is in the middle of that great 
 slope, or inclined plane, whose bottom lies to- 
 wards the center of France, and which terminates 
 in the upland that directs the course of the 
 Rhone to the westward. The primitive soil (an- 
 terior to the volcanoes) is of granite, covered 
 in some places with a marly limestone. The 
 valleys excavated in this soil render the country 
 unequal, and give it a mountainous appearance, 
 although there are in fact only excrescences or 
 volcanic mountains, which rise above the genera! 
 plane of the slope, 
 
 " Nearly all this soil has been covered with 
 volcanic productions: they are of three kinds, 
 and their formation seems to date from three 
 distinct epochs. The most recent and least 
 
 * This is the proper spelling, derived from the river Dor, which, 
 joining the Dogne, forms the Dordogne. See Le Grand. 
 
 
4$ BOMAlN I. SIDEROUS, 
 
 numerous are currents of lava, which lead to 
 craters still existing; the second are masses or 
 tables of basalt, separated by rifts or valleys ^ 
 the third consists of mountains whose mass is a 
 kind of volcanic porphyry. 
 
 "1st. Lava in form of currents. There are in 
 Auvergne near a hundred conical, isolated moun- 
 tains, from 200 to 400 yards in height, formed 
 of heaps of scoriae, fragments of lava and of la- 
 pillo : their summit often presents a hollow in 
 the form of a cup or crater : they rest imme- 
 diately on granite. From the bottom of several 
 of them currents are observed to run of lava of a 
 basaltic nature, that is of a greyish black, with 
 a fine compact grain : this lava contains grains 
 and crystals of peridot (olivine), augite, felspar, 
 &c. The superficies is blistered and studded 
 with asperities, which sometimes attain and even 
 surpass a yard in height: the interior is more 
 compact, and less porous, as you arrive nearer 
 to the bottom. The currents are spread in the 
 adjacent plain ; they have sometimes reached 
 the bottom of certain valleys, and have followed 
 their Bourse for a distance of three or four 
 leagues ; in advancing progressively they always 
 incline to points lower and lower ; they follow 
 the inequalities of the soil; they separate, on 
 meeting with any obstructing eminences in their 
 
MODE III. BASALTIN. 49 
 
 passage. In fact, like the courses of fluid mat- 
 ter, they have been subservient to all the laws of 
 hydrodynamics. The history of these currents 
 of lava is complete, and there is nothing left to 
 the imagination to supply. We behold the ori- 
 fice from whence they issued, the course they 
 pursued, the country they occupy, &c. 
 
 " They flowed upon granite : their substance 
 then was either in or under that rock ; now these 
 lavas contain from 15 to 20 per cent, of iron; 
 the granite possesses scarcely any ; they do not 
 therefore consist of granite, fused and wrought 
 by volcanic agents: we must therefore, with 
 Dolomieu, seek under this rock, for the matter 
 which has yielded this substance ; but here we 
 can only form conjectures. The cause which 
 may have developed this subterranean fire, the 
 combustible matter which may have maintained 
 it, are entirely unknown to us. It is not coal, or 
 bituminous matter, for they are only found in 
 secondary regions, and never either in or under 
 granite: it does not consist in pyrites, because 
 pyrites, alone and enclosed in the bosom of the 
 earth, never decompose, and generate no heat. 
 As for the period when these lavas flowed, al- 
 though anterior to the history or tradition of 
 mankind, it is nevertheless very recent when 
 compared with those vast degradations which 
 
 VOL, i. E 
 
50 DOMAIN I. SIDEROUS. 
 
 the surface of the globe presents : it is posterior 
 to the entire excavation of the valleys, since it 
 occupies their bottoms. 
 
 " 2d. Basalts. The volcanic productions of 
 the second kind, are basalts, which, under the 
 form of sheets, tables, peaks, cover the elevated 
 parts of the ancient soil, or constitute the sum- 
 mit of some mountains and isolated eminences ; 
 they are also observed on almost all the skirts of 
 Mont Dor and Cantal ; they are evidently only 
 the remains and patches of different currents, 
 which have spread over the country; they pre- 
 sent the same mineralogical characters as the 
 basalts of other countries, Saxony, &c. ; they 
 contain the same substances ; they equally in- 
 cline to a prismatic division ; they cover without 
 distinction all kinds of rocks, and are never 
 covered by them, &c. 
 
 " A volcanic origin cannot be denied to these 
 basalts. The perfect resemblance between their 
 paste and that of some parts of currents of lava 
 which are found in the neighbourhood, and 
 which have come from a crater still existing, is 
 already a very strong presumption; but they 
 present other infallible marks of this origin. 
 1. In following step by step certain masses of 
 basalt which are near Mont Dor and Cantal, 
 and supplying by the imagination what has vi* 
 
MODE III. BASALTIN. 
 
 sibly been taken away, you arrive at the sides 
 of those two enormous volcanic mountains, and 
 you come to masses of scoriag or of blistered 
 rocks, where, beyond doubt, we are near the 
 source of the current ; all the basalts which have 
 been followed upwards, made part of that cur- 
 rent. 2. A great number of those large basaltic 
 platforms which cover isolated mountains, dis- 
 play on their surface blisters, spongy scoriae, or 
 drosses, like those which are observed on the 
 best preserved lavas ; nor can we refuse them a 
 simitar origin. Some others of these platforms 
 repose on volcanic ashes. 3. Some isolated 
 eminences present, it is true, summits of black 
 basalt, compact, prismatic, destitute of those un- 
 equivocal signs of the action of fire which are seen 
 elsewhere ; but the greatest part of them stands 
 by the side of those platforms with scoriated sur- 
 faces of which we have just spoken : they once 
 formed with them a continued whole, and have 
 evidently only been divided from them by the 
 excavation of the valleys and ravines which now 
 separate them. They cannot have had a differ- 
 ent origin ; the corrosive action of time and the 
 elements must have destroyed the scorified bark; 
 only the compact nucleus would remain, de- 
 prived of the marks of the action of fire, as are 
 the interior parts of the greater portion of lavas 
 
 E 2 
 
DOMAIN I. SIDEKOUS. 
 
 in currents. Thus all the basalts of Auvergnc 
 present proofs, either direct or indirect, of a vol- 
 canic origin; though the degradation of the 
 soil, the dismemberment that the currents have 
 suffered, no longer permit us to retrace the cra- 
 ter from whence they flowed, nor to see the 
 number, form, or extent, of the different cur- 
 rents: the only positive thing we can say in 
 regard to them is, that their existence is anterior 
 to the excavation of the valleys. 
 
 " 3. Porphyroid Masses. The third species 
 of volcanic productions of Auvergne is quite of 
 a peculiar nature ; they are grey stony masses, 
 of a porphyritic structure ; they form eight or 
 ten distinct mountains : the most considerable 
 are Cantal, whose diameter at the base may be 
 about nine or ten leagues, and 900 or 1000 yards 
 high, above its bottom ; the Mont Dor, whose 
 base is five or six leagues, and its height from 
 1000 to 1100 yards; the Puy de Dome, whose 
 base is half a league in diameter, and 600 yards 
 high : the other mountains are still less. The 
 two first are vast masses, torn and irregularly 
 cut by the action of the waters. The substance 
 of which they are all composed is grey, often 
 approaching to black, sometimes to green ; its 
 fracture dull and earthy, with coarser or finer 
 grains j it has little hardness, and easily decom- 
 
MODE III. BASALTIN. 53 
 
 poses ; its weight is about twice and a half 
 greater than that of water ; it melts easily under 
 the blowpipe into white amel*, and seems to be 
 composed of the same elements as felspar, but 
 confusedly united ; it contains a great quantity 
 of crystals of felspar, some acicular crystals of 
 hornblende, and even some spangles of mica. 
 The klingstein-porphyr of the Germans f, which 
 is found in considerable quantity at Mont Dor 
 and Cantal, seems s to be only a remarkable va- 
 riety. 
 
 " These porphyroid masses so nearly resemble 
 certain productions in the humid way, that it 
 required nothing less than their extraordinary 
 position, their situation in the midst of volcanoes, 
 some unequivocal marks of the action of fire, 
 their passage direct or indirect to basalt, and 
 above all the volcanic scoriae imbedded in their 
 mass, to prove that they are foreign and poste- 
 rior to the productions in the humid way, and 
 that they owe their existence to the volcanoes. 
 
 " Nothing positive can be said as to the man- 
 ner in which they have been produced, and 
 arrived at their present position. No where is 
 
 * See Johnson. Enamel is properly the application of the amel 
 to another substance. 
 
 f Klaproth procured 8 per cent, of soda from caat of Bohemia, 
 and Mr. Bergman 6 from that of Mont Dor. 
 
DOMAIN I. SIDEROUS. 
 
 there observed any crater from which they could 
 have issued, nor distinct currents by which they 
 might be traced to their origin. It might be 
 thought that they consist of melted granite, 
 wrought and ejected by volcanic agents. The 
 homogenity of their paste shows how complete 
 the fusion or igneous dissolution has been, and 
 scarcely permits one to believe that the number 
 of crystals of felspar which they contain, should 
 have pre-existed the fusion, and withstood it. 
 The form of these crystals, their laminar struc- 
 ture perfectly preserved, their transparency, 
 their facility of melting, their manner of being 
 in these vast masses, and in short their analogy 
 of composition with the paste which surrounds 
 them, leads one to believe that they were formed 
 during their igneous fluidity, by an approxi- 
 mation of their integrant parts, which were able 
 to obey the laws of their affinity. These por- 
 phyroids are the most ancient of all the volcanic 
 productions of Auvergne : they are covered with 
 basalt, and contain veins of -that substance. 
 
 " However different these productions may 
 be, however distant the various periods of their 
 formation, they do not seem the less united in a 
 certain degree, and form, in some sort, an identic 
 system. Cantal, Mont Dor, Puy de Dome, &c. 
 the most ancient of the volcanic masses, are in 
 

 MODE III. BASALTIN. 
 
 a direct line, running nearly from south to north. 
 Almost all the basalts of these regions, that may 
 be, in some manner, retraced to their origin, 
 seem to have taken their direction in this same 
 line. It is also in this direction, and among the 
 ancient products, that the greater part of the 
 craters have opened, whose vestiges are still 
 visible. When at two leagues to the westward 
 of Clermont, we see near sixty volcanic moun- 
 tains, ranged in a straight line, one can scarcely 
 believe it to be the effect of chance. A cause 
 has certainly existed which has produced this 
 effect : perhaps there was under-ground, and in 
 this direction, as it were a vein of matter which 
 contained the germ of volcanic fire, or which 
 was of a nature to maintain it ; the cause always 
 existing, its effect might have been renewed at 
 different periods." 
 
 These observations are no doubt cogent, and 
 worthy of the acknowledged ability of the au- 
 thor. But in the spirit of perfect candour when 
 treating a subject where it is difficult, after every 
 allowance for the weakness of the human mind, 
 even to suppose that prejudices should exist, 
 Broch ant's able abstract of the arguments for 
 and against the volcanic origin of basaltin, shall 
 here be subjoined, as the author thinks it a me- 
 ritorious service to the science, to lay before the 
 
56 DOMAIN I. SIDEROUS. 
 
 English reader interesting extracts from such 
 works in the foreign languages, as, from their 
 very nature, can scarcely be expected ever to be 
 known to him by translation. 
 
 statement " ^ nas a ! rea( ty ^ een sa ^ m ^ e Introduction, 
 p. 68, that mountains of secondary trap, and 
 chiefly the basalts, were looked upon by some 
 mineralogists as produced by volcanic fires, while 
 Mr. Werner, and almost all the learned men of 
 Germany, are of opinion, that they have been 
 formed, like other rocks, by the waters which 
 inundated the surface of the globe. 
 
 ce The former ground their opinion on the fol- 
 lowing reasons. 
 
 " 1. In the masses produced by volcanoes 
 which have burnt in our time, are found pris- 
 matic basalts, and other rocks which' resemble 
 trap, and which nevertheless bear no character 
 of fusion, and which only the locality and po- 
 sition indicate as volcanic. 
 
 " 2. It is an error to believe that all the 
 masses ejected by volcanoes must be vitrified 
 substances ; such are on the contrary very rare. 
 
 " 3. Neither is the black colour essential to 
 volcanic products : there are some grey, others 
 brown, and even white. 
 
 " 4. Many observations have proved, that the 
 fire of volcanoes is very inferior to that of our 
 
MODE III. BASALTMN. 57 
 
 furnaces; therefore it is not surprising that ba- 
 salts may be changed by an artificial fusion; and 
 it is no reason for believing that they have not 
 before undergone the action of volcanic fires. 
 
 " 5. Even supposing that volcanic fire pos- 
 sesses a great heat, it is known, by the beautiful 
 experiments, made in England by sir James Hall, 
 comparatively on the whinstone*, and on the 
 lavas of Vesuvius, that a contexture and aspect 
 may be given to a rocky mass, melted and cooled, 
 which shall have the characters of glass or stone, 
 according as the cooling is quicker or slower. 
 These experiments having been repeated on 
 several kinds of whinstone,*there has always been 
 obtained by a gentle cooling, a stony mass, com- 
 pact, dull, exactly similar to the whinstone em- 
 ployed ; and on the contrary, a vitreous mass 
 was obtained by a rapid cooling. The same 
 essays made on the substance of bottle glass, 
 gave the same results. 
 
 " We see then that the absence of scoriae and 
 vitrifications is not a reason for denying the vol- 
 canic origin of basalt; besides, it is a known 
 fact that burning volcanoes have produced it. 
 
 " * The whinstone of the English is generally a secondary trap ; 
 but among several specimens that 1 have seen given under that 
 4iame, some resembled basalt, others grunstein ; others in fine had 
 4he structure of amygdalite." 
 
58 DOMAIN I. SIDEROUS. 
 
 " 6. But without mentioning basalts, which 
 have so many volcanic characters, a great ana- 
 logy is found between secondary mandelstein 
 and porous lavas; between the clay of trap 
 mountains and the products of muddy eruptions; 
 between basaltic tufa and volcanic tufa; and 
 almost all minerals which are found scattered 
 in volcanic masses, are found in trap moun- 
 tains, &c. 
 
 " 7. The position of secondary traps, which 
 lie over all secondary rocks, while the hardness, 
 compactness, and other characters of many 
 among them, such as grunstein, basalt, and 
 others, are so different from those of the se- 
 condary rocks on which they lie. That kind 
 of dry ness to the feel which they present, and 
 which is characteristic of volcanic productions 
 in general, .all these approximations will not 
 permit us to acknowledge that basalts have had 
 the same origin as all secondary rocks. 
 
 " 8. It has been objected that in basaltic 
 countries basalt is found on almost all the sum- 
 mits, and that such would not be the case if 
 basalts were lavas: this might be true if these 
 lavas proceeded from a recent deposition ; but 
 on the contrary this deposit seems very ancient, 
 and has undergone many changes. M. Reuss 
 himself observed in Bohemia, that the basaltic 
 
MODE III. BASALTIN. 
 
 summits he there met with, seem to be the 
 remains of a vast bed of decayed basalt. 
 
 " 9. In sh >rt, the conical form of trap moun- 
 tains, and above all those of basalt, has the most 
 perfect resemblance to that^ of volcanic moun- 
 tains; and it is this resemblance which gave the 
 first idea of attributing - a volcanic origin to 
 basalt. 
 
 " The advocates for the formation by the hu- 
 mid way, or the Neptunists, on their part sup- 
 port their opinions by many observations, of 
 which these are the principal : 
 
 " 1. It is true basalts are found among pro- 
 ducts of burning volcanoes, but they are ex- 
 tremely rare, and modern eruptions have not 
 produced any. 
 
 " 2. Whatever origin may be attributed to 
 the division in prisms, tables, &c. it is not pecu- 
 liar to trap rocks: there are gypsums, marls, 
 sand-stones, which frequently offer this struc- 
 ture. Thus then this division in prisms, very 
 rare among real volcanic products, on the con- 
 trary exists in many stratified rocks. 
 
 " 3. Basalts often repose immediately on coal, 
 as at Meissner, near Cassel : now, if this basalt 
 was volcanic, it must necessarily have produced 
 the combustion of these beds of coal, 
 
 " 4. The remains of vegetables and animals, 
 
()0 DOMAIN I. SIDEROUS. 
 
 which are found in some trap rocks, could not 
 in like manner have resisted the volcanic heat 
 without being destroyed. 
 
 " It is the same with many minerals which 
 are very fusible, and which are there met with : 
 indeed, some are also found in volcanic rocks, 
 but these instances are rare, and cannot serve as 
 a basis to a general rule. 
 
 " 5. Cavities filled with water, such as en- 
 hydritic agates found near Vicenza, in Italy, in 
 secondary trap mountains, entirely destroy all 
 supposition of a volcanic origin*. 
 
 t( 6. There are not observed in trap rocks either 
 that black colour, or those indications of vitri- 
 faction, that are apparent, at least in certain por- 
 tions, of the products of burning volcanoes : real 
 craters have never been observed. All those 
 which have been cited were hollows, chasms 
 filled with water, so common in some moun- 
 tains. 
 
 " 7. Mandelstein has certainly some resem- 
 blance to porous lava; but there are mandel- 
 steins evidently not volcanic. Besides, the 
 cavities of the mandelstein of trap mountains 
 contain very different minerals, and which could 
 
 " * The Vulcanists answer that these agates have a latter origin 
 rom infiltration." 
 
MODE III. BASALTIN. 
 
 not have undergone the action of fire without 
 being changed*. 
 
 " 8. It is true, that according to the experi- 
 ments of sir James Hall, and some late ob- 
 servations made upon burning volcanoes, it is 
 known that rocky substances may, after fusion, 
 reassume their stony character; but when this 
 takes place in burning volcanoes, there are al- 
 ways found in the vicinity substances which 
 have not experienced this effect, and which on 
 the contrary are scorified or vitrified; which 
 denotes the action of fire. 
 
 " 9. In different countries, and especially in 
 Bohemia and the Vicentine, beds of basalt have 
 been observed, which alternate with grit, or stra- 
 tiform limestone : does not this reunion of these 
 two rocks prove that they have had the same 
 origin ? The Vulcanists, to make this agree with 
 their theory, are obliged to have recourse to 
 quite a forced supposition, according to which 
 there have been alternately volcanic eruptions 
 and submarine deposits; whereas this alternation 
 of beds of different rocks, of nearly contemporary 
 formation, has more than one example in moun- 
 tains. 
 
 " 10. There are many basaltic regions where 
 
 " * The same observation as in note upon article 5." 
 
DOMAIN I. SIDEROUS. 
 
 basalt is only found on summits, and it is evi- 
 dently perceived by the correspondence of the 
 beds, that all these summits were parts of one 
 and the same bed, which spread over all the 
 country : now, that is not the nature of volcanic 
 deposits ; they form currents, which take a cer- 
 tain direction, and no similar examples of such 
 vast deposits are known, but among rocks pro- 
 duced by water, and particularly among strati- 
 form rocks. 
 
 "11. Basalt has no appearance of fusion; 
 heated in a furnace it melts to glass. It is true, 
 that from Hall's experiments, a stony substance 
 has been obtained ; and that may very well hap- 
 pen, since nature produces it in burning vol- 
 canoes. But these cases are very rare, and Hall 
 has justly observed, that in his experiments this 
 appearance depended on the management of the 
 cooling : but it must then be supposed, that this 
 circumstance is always met with in the volcanic 
 eruptions, which are supposed to have produced 
 the mountains of trap. 
 
 " 12. The prismatic division of basalt has 
 been attributed to the water of the sea, which 
 they say then covered all the region upon which 
 these lavas have run: that is possible; but this 
 accelerated refrigeration should, according to 
 Hall's experiments, give the lavas a vitreous 
 
MODE HI. BASALTIN. 
 
 appearance; which is not the case even in por- 
 tions of the mass. 
 
 " 13. The conical form of basaltic mountains 
 proves nothing ; it is true, that such is the form 
 of volcanic mountains, but in general it is that 
 of all mountains whose sides are covered with 
 earthy substances. Melted substances, ashes, 
 give this form to volcanic mountains; and if 
 basaltic mountains assume also more particularly 
 this appearance, it is because their fragments 
 are quickly reduced to this earthy state, so that 
 they naturally form slopes on the sides of moun- 
 tains. 
 
 (l Moreover, the conical form of basaltic moun- 
 tains is not that of burnirTg volcanoes: the former 
 are cones, isolated one from another, nearly 
 equal in height; whereas volcanic mountains 
 are grand coniform elevations, whose slopes and 
 sides are loaded with little conical summits. 
 
 " One might extend much farther this chain 
 of motives on which both theories are founded, 
 but longer details would be here superfluous*; 
 
 " * It may be observed, that the points of division are often in 
 matters of fact j as the existence of scoriae, vitrifactions, that of 
 craters, &c. I do not pretend to discuss their legitimacy. 
 
 " Perhaps both parties may think that I have not done justice to 
 their arguments, and that I have overlooked some important ones. 
 I believe not : I endeavoured to reconcile them, at least the princi- 
 pal ; but I confess if any have escaped me, I should easily console 
 
64? DOMAIN I. SIDEROUS. 
 
 time may perhaps some day afford the definitive 
 solution of this great geological problem. Do- 
 lomieu occupied himself much upon if 5 and he 
 doubtless would have succeeded in uniting both 
 parties, if death had not overtaken him in the 
 midst of his labours. He adopted neither of the 
 two opinions : he was persuaded that both were 
 admissible, according to localities; because hav- 
 ing often seen in the products of the burning 
 volcanoes of Italy, rock entirely resembling ba- 
 salt, and even other primitive rocks, he had 
 found by long experience, that only the charac- 
 ters of locality would decide on the origin of 
 either. He had, according to this principle, 
 observed some basaltic countries, among others 
 Auvergne and the Vicentine, and he had re- 
 garded them as volcanic. I chiefly cite these 
 two examples, because I know that many cele- 
 brated German mineralogists are of a contrary 
 opinion*." 
 
 A yet later French mineralogist has thus ex- 
 pressed his sentiments upon this curious and 
 long- agitated subject. 
 
 myself, if I thought that would induce the advocates of the tvro 
 opinions to publish fresh memoirs, to undertake their own defence. 
 This great quarrel has been long hushed, and probably both parties 
 foave collected new observations." 
 * Brochant, ii. 6 12. 
 
MODE III. BASALTIN. 65 
 
 Cc We shall give a third opinion upon the ori- Brongniart's 
 gin of basalt, in a medium between the two pre- 
 ceding ones, and which appears to us the most 
 probable. The naturalists who profess it, as 
 Fortis,Dolomieu, Delrio, Spallanzani, think that 
 the discussion on basalt is often a dispute of 
 mere words : that if this name is given to those 
 stones whose characters we explained at the be- 
 ginning of this article; some are truly volcanic, 
 while others have entirely an aqueous origin; 
 that the basalts of Saxony, and those of Ethiopia, 
 certainly belong to this second division, and that 
 it is probable that those of Scotland and Ireland 
 also belong to it ; while those of Italy, and Au- 
 vergne, should be arranged in the first class to- 
 tally, or at least in part. 
 
 "Other naturalists, and particularly M-Patrin^ 
 imagine that basalts are the productions of the 
 muddy eruptions of submarine volcanoes 5 and 
 that the nature of the eruption, and the influence 
 of the water, have given to this lava those par- 
 ticular characters for which it is remarkable. 
 They believe that the latter influence prevented 
 the basaltic matter from calcining or burning 
 those substances on which it flowed. This hy- 
 pothesis, which seems one of the most probable, 
 if not applied without exception to all basalts, 
 explains well enough the alternation of beds of 
 
 VOL, i. F 
 
^ DOMAIN I. SIDEROUS. 
 
 prismatic basalt with beds of basalt, or stony 
 and earthy matter without order; that of these 
 same beds of basalt with sand-stone, with car- 
 bonate of lime, or with coal, which are not 
 altered by it; in short, the presence of fossil 
 shells in some basaltic beds. The causes which, 
 in this hypothesis, concurred in the formation of 
 prismatic basalt, no longer existing, we see why 
 basalt is no longer formed in those vast currents 
 of lava which in our days have issued from vol- 
 canoes. It seems that it is with basalt, as with 
 veins, crystallised beds, fossils properly so called, 
 &c. Nature in her present quiescent state no 
 longer forms any*." 
 
 The extent of these observations will be par- 
 doned, as there is not, in this science, a topic 
 more difficult or interesting : but we must now 
 return to a more immediate view of this cele- 
 brated substance. 
 
 STRUCTURE I. AMORPHOUS. 
 
 This rock, as already mentioned, is the trap of 
 the Swedes, who first recommended it to modern 
 notice ; while the basaltic columns of Saxony had 
 
 * Brongniart, i. 473. He had observed, p. 470,' that lava enter- 
 ing the sea becomes fixed on the surface, and does not assume a 
 columnar form, which rather proceeds from slow cooling. 
 
MODE III. EASALTlN. 67 
 
 been observed by Agricola, the restorer of mine- 
 ralogy in the sixteenth century. Whatever be 
 their origins, these two substances are identically 
 the same ; as the same results may be produced 
 either by the humid or the dry processes of che- 
 mistry. 
 
 Aspect 1. Uniform. The columnar basaltin 
 had, as already mentioned, attracted great atten- 
 tion by the beauty and regularity of its forms, as 
 early as the sixteenth century ; but trap, or stra- 
 tiformed basalt, may be called a discovery of the 
 Swedes. The hill of Kinnekulla, in Westrogothia, 
 was one of the first observed ; and also that of 
 Hunneberg, in the same province. 
 
 Black basaltin, from Kinnekulla and other parts 
 of Sweden. 
 
 Grey basaltin, from the same. 
 
 Greenish, from Norberg. 
 
 Reddish, from Sweden. 
 
 Black basaltin, with small needles or scales of 
 siderite, from Sweden. 
 
 Stratified basaltin, from Faroe, Stafta, the 
 Giants' Causey, &c. where it sometimes underlies 
 the columnar. 
 
 The same, from the castle hill of Edinburgh, 
 Dumbarton, and other parts of the south of Scot- 
 land. 
 
DOMAIN I. SIDEROTIS. 
 
 The same, from Andernach on the Rhine. 
 
 The same, from the Sierra Morena, or Black 
 Mountains, in Spain. 
 
 The same, from Toplitz in Bohemia. 
 
 Black basaltin, from Egypt. 
 
 Green, from the same. 
 
 Red basaltin, from Channelkirk in Scotland. 
 
 Brown, from the same. 
 
 Stratiformed basaltin, from Saxony. 
 
 The same, from Etna, Vesuvius, the isle of 
 Bourbon, New Spain, and other volcanic re- 
 gions*. 
 
 Aspect 2. Mingled. Basaltin, with nodules 
 of steatite, from the isle of Skey in Scotland, 
 Westrogothia, &c. 
 
 Black basaltin, with red zeolite, from Sweden. 
 
 The same, with white zeolite, from Staffa, Giants" 
 Causey, c. 
 
 The same, with many beautiful varieties of zeo- 
 lite, from the Faroe isles. 
 
 The same, with zeolite, from Etna, &e. 
 
 The same, with grains of pyrites, from Hunne- 
 berg in Sweden, Dauphiny, &c. 
 
 * Saussure mentions, 14Q7, a kind of basalt which may be 
 called laminar: and, 548, a singular roche de come, (basaltin?) 
 in thin leaves, with mica, quartz, and felspar. If compact, he 
 says, it would have formed a genuine porphyry. How > 
 
MODE III. BASALTIN. 
 
 The same, with nodules of calcareous spar, 
 from various parts. 
 
 The same, with red jasper, from Derbyshire. 
 
 Basaltin, passing in veins through granite, from 
 Norway. With inherent pitchstone, from the 
 Rhine. 
 
 Aspect 3. Basaltic Tufa. This substance has 
 been observed at Staffa, and in some other basaltic 
 countries. A considerable portion of Arthur's 
 seat, near Edinburgh, is composed of it. 
 
 Aspect 4. Basaltic Bricia. Bricia, with frag- 
 ments of granite, on a base of basaltin, either 
 black, grey, or green, from Westrogothia in Swe- 
 den, or from Dauphiny in France. 
 
 The same base, with fragments of quartz, from 
 the same. 
 
 The same, with fragments of limestone, from 
 the Alps of Dauphiny. 
 
 The same, with fragments of slate, from the 
 same, and from the mountain of Tarare, near 
 Lyons. 
 
 The same, with fragments of granite, slate, and 
 limestone, all mingled, from Tarare, and Dau- 
 phiny. 
 
 The same, with fragments of porphyry, from 
 the hill of Lesterelle in Provence. 
 
70 DOMAIN I. SIDEROUS. 
 
 Bricia of fragments of basal tin, joined by a 
 cement of quartz, intermixed with particles of 
 basal tin. Uncertain. 
 
 STRUCTURE II. COLUMNAR. 
 
 pasaitin of Aspect 1. Uniform. Basaltin, from Stolpen. 
 
 Stolpen. , 
 
 in Saxony. Remarkable as having attracted the 
 attention of Agricola, and other naturalists since 
 the sixteenth century. The little town of Stolpen 
 is built upon the side pf a basaltic hill, a few 
 miles to the east of Dresden. The lower part of 
 the hill consists of a granite, of white felspar, 
 grey quartz, and black mica, upon which the ba- 
 salt reposes, presenting the most beautiful and 
 regular columns observable in Germany*. They 
 have commonly six sides; but some have four, 
 five, seven, or eight; yet their length does not 
 seem to exceed fifteen or sixteen feet. The co- 
 lumns are vertical ; but on the south-east there is 
 a rock of stratified basalt, of that kind which ap- 
 pears in thin plates or tables. The basaltin of 
 Stolpen is black with a bluish cast, the grain being 
 impalpable, the fracture conchoidal, and the frag- 
 ments sharp. Its hardness, like that of siderite 
 and basalt, equals that of iron the hardest metal, 
 jbeing more than 800 of Quist's gradation. This 
 
 * Daub, sur les basaltes, 42. 
 
MODE III. BASALTIKT. f \ 
 
 basaltin often presents little cavities, lined with 
 chalcedony, and quartz crystals ; sometimes filled 
 with green steatite, calcareous spar, zeolite, or a 
 lithomarga, resembling semiopal. Small grains of 
 olivine also occur, and dots of siderite, or perhaps 
 augite. The pillars are used for many useful and 
 ornamental purposes of architecture ; an example 
 which might be followed in other basaltic coun- 
 tries, with a sacred regard however to the more 
 regular, grand, and conspicuous parts. 
 
 Columnar basaltin, from Italy, Sicily, Auvergne, 
 Hungary, Bohemia, Saxony, Lusatia, Thuringia, 
 Hessia, Goetingen, Nassau, in Germany; from 
 the isle of Bourbon, New Zealand, and other isles 
 in the South Sea, &c, &c. The columns are often 
 so small as to be chosen as specimens. 
 
 Aspect 2. Mingled. Columnar basaltin, min- 
 gled with zeolite, from many countries. 
 
 With nodules of steatite, calcareous spar, chal- 
 cedony, lithomarga, olivine, &c. from Stolpen, and 
 other places. 
 
DOMAIN I. SIDEROUS. 
 
 MODE IV. BASALTON. 
 
 characters. Texture coarse, and of a large grain, mixed 
 with quartz or felspar, but lax, and incapable of 
 the fine polish of basalt or basaltin. 
 
 Hardness marmoric. Fracture commonly 
 even. Fragments blunt and amorphous. 
 
 Weight sometimes siderose, generally grani- 
 tose. 
 
 Lustre glimmering. Opake. 
 
 Colour grey or greenish. 
 Name. As the Italian termination ino designates di- 
 minutives and substances of a finer nature, so 
 that in one is employed to discriminate those of 
 a coarse appearance or large grain. Hence the 
 name basaiton is adopted for another branch of 
 the basaltic family, that called grunstems by the 
 Germans, an appellation alike vague and bar- 
 barous, as are most of those terms derived from 
 the vulgar miners. The most important and 
 beautiful of the grunsteins, a mixture of crystal-? 
 lised siderite with felspar, has been already de- 
 scribed after siderite. By basalton are under- 
 frwSteki. stood the other kinds of grunstein, except the 
 porphyries; being a mixture of coarse basalt, 
 without the splendour or cohesion of that sub- 
 $tance, with either felspar or quartz. Even that 
 
MODE IV. BASALTON. 73 
 
 with a finer grain must still be regarded as a 
 coarse rock, as it does not admit the polish of 
 basalt or basaltin. The common whin-stones 
 of the north of England and of Scotland belong 
 to this class. It is unnecessary to indicate many 
 examples of so common a substance, which is 
 chiefly interesting from its intimate connexion 
 with basalt and basaltin, often passing either 
 into the one or the other of these substances. 
 
 Werner has considered grunstein as either 
 primitive or stratiform. The former has been 
 here described under the venerable name of 
 Wallerite; the latter, which commonly covers 
 the beds of basalt, is that about to be mentioned. 
 It would Appear that he has since added a trans- 
 itive gritfistein, distinguished by veins or grains 
 of quartz, in Voigtland called leberfdls, or li- 
 ver rock, being coloured with a reddish brown 
 oxyd of iron. This transitive grunstein occurs 
 in the Hartz, in Bohemia; and, according to 
 Mr. Jameson, in the upper part of Dumfries- 
 shire. The Wernerians regard grunstein as a 
 more chemical solution than basalt, though it 
 commonly rest upon the latter; while in general 
 the more chemical dissolutions are the lowest : 
 a circumstance which they endeavour to ex- 
 plain by supposing the superincumbent waters 
 fnore agitated at one period than at another, 
 
74 
 
 DOMAIN I. SIDEROUS. 
 
 Grunstein 
 slate. 
 
 STRUCTURE I. COMPACT BASALTON. 
 
 Compact basalton, from some of the interior 
 pillars of Stonehenge. 
 
 Basalton, or whin, from Salisbury Crags, near 
 Edinburgh. 
 
 The same, from the Malvern hills. 
 
 Basalton is common in the pavement of London. 
 
 STRUCTURE II. SLATY BASALTON. 
 
 This is the green-stone slate of the Germans, 
 being composed of siderite and compact felspar, 
 or felsite, which is sometimes more abundant than 
 the former. It is said to form mountains in 
 Sweden, and abounds near the mines of Adelfors, 
 being often metalliferous. If the felsite generally 
 exceed in quantity, it ought to be classed under 
 that rock. 
 
 KKnkstein. The porphyry slate, or clink-stone porphyry, of 
 Werner, basalte en table of the French, seems an 
 intimate mixture of iron and felsite, and is often 
 found in basaltic countries. It has been analysed 
 by Klaproth, who found eight parts of soda in a 
 hundred. How it came to be classed among the 
 basaltic family can scarcely be imagined, except 
 from its local situation, a circumstance too pre- 
 ponderant with Werner ; it being as often found 
 in the vicinity of basaltin, as lava with a base of 
 
MODE V. PORPHYRY. 
 
 felsite is in that of lava with a base of siderite. It 
 is surprising that the French mineralogists have 
 not adduced this circumstance in favour of the 
 volcanic origin of basal tin. Clink-stone however 
 lias no sort of relation to the family of basalts, as 
 the chemical analysis infallibly demonstrates ; for 
 it only contains 3 in the 100 of iron, while all the 
 other modes present more than 20. It is there- 
 fore here classed under Felsite, with which the 
 analysis strictly corresponds, except that there is 
 double the quantity of iron, which imparts the 
 black colour. 
 
 MODE V. PORPHYRY. 
 
 This rock belongs to the division here called Name. 
 Int rites, as consisting of crystals or grains im- 
 bedded in a base or paste, in contradistinction 
 to Granites formed by simple coherence, and to 
 Glutenites, (both also derived from the Latin), in 
 which the particles are cemented together by 
 the same or by a different substance, scarcely 
 visible, or at least not so abundant as in the 
 Intrites*. This last denomination, besides in- 
 stantly recalling to memory the nature of the 
 rock, would prevent the misapplication of the 
 
 * In like manner the Glandulites of Saussure are those stones 
 which include glands or kernels. 
 
 TTNTVFPRTTV 
 
76 -DOMAIN I. SIDEROUS. 
 
 classical term porphyry to many substances, 
 which have only a very faint and distant resem- 
 blance. 
 
 The term porphyry is therefore here restrict- 
 ed to its proper and peculiar sense of a base 
 sprinkled with crystals of felspar. The word in 
 the Greek implies a purple, or rather red stone ; 
 and in severe classical precision ought to be 
 confined to that colour, common among the 
 monuments of antiquity : but as denominations 
 derived from colour, the worst of all distinctions, 
 have been forced to be extended, the black, the 
 grey, the bluish, and even the green, having 
 the same base of trap or basaltin, must be in- 
 cluded. But the base being the sole ground of 
 the present classification, all the other kinds are 
 considered as Intrites, and reserved for separate 
 descriptions. 
 
 Base. It was long imagined that the base or ground 
 
 of porphyry consisted of jasper ; but this suppo- 
 sition has been finally rejected, and it has been 
 found to be trap, from its fusibility and other 
 chemical properties, and likewise from its exter- 
 nal attributes. Like basaltin, it presents crys- 
 tals of siderite, grains of quartz, and sometimes 
 glandules of chalcedony and of steatite, which 
 last perhaps forms the green matter in Swedish 
 porphyry. The crystals of felspar are generally 
 
MODE V. PORPHYRY. 77 
 
 rectangular, but sometimes oval or otherwise 
 irregular. When they are scarcely visible to 
 the naked eye, the substance is here called por- 
 phyrin ; and when they exceed an inch in size 
 the term porphyron may be applied. 
 
 Genuine porphyry abounds in many parts of 
 the world, and often forms entire mountains. 
 Like siderite it has been found to alternate with 
 gneiss, and it occurs in a columnar form. Among 
 the defects of orology, and even of the Wer- Werner's 
 nerian theory of formations, maybe chiefly par- 
 ticularised the classification of the porphyries, 
 vaguely so called, which are arranged under one 
 head, whether the base be keralite, felsite, pitch- 
 stone, or even serpentine, or indurated clay ; 
 while felspar, like mica, may be occasionally 
 found in most rocks, and these pretended por- 
 phyries ought all to be referred to their several 
 bases. The name has even been extended to 
 rocks with calcareous or other crystals : and as 
 strict definitions form the first foundation of every 
 science, no argument can more clearly evince 
 the necessity of new and abundant denomina- 
 tions of rocks, than this confusion of substances 
 of a nature wholly remote ; and so frequent and 
 important, that no geological work can be pro- 
 perly understood, except the author use much 
 circumlocution. For to extend the term por- 
 
DOMAIN I. SIDEROUS. 
 
 phyry to every substance in which small crystals 
 are imbedded, is as absurd as it would be to con- 
 found granular limestone with granular quartz; 
 or any other remote substances merely of similar 
 structure, or even aspect. 
 
 STRUCTURE I. PORPHYRY WITH LARGE CRYSTALS 
 OF FELSPAR. 
 
 Aspect 1. Red Porphyry. This kind is fre- 
 quent in ancient monuments. The crystals are 
 seldom so regular as those of the next structure. 
 It is sometimes interspersed -with globules of a 
 finer porphyry 3 or even of porphyrin. 
 
 Porphyry, from Egypt, or the ruins of Rome. 
 
 The same, from the Grampian Mountains in 
 Scotland. It chiefly occurs in Glenco*. 
 
 The same, from Corsica. 
 
 Aspect 2. Black. A fine column of this kind 
 is in the church of St. Prassede, at Rome. 
 
 Aspect 3. Green. This has sometimes been 
 called verd-antique, but the proper verd-antique 
 is a mixture of serpentine and white marble. The 
 green porphyry has also been erroneously supposed 
 
 * Which must not be confounded with Glen Cro, not far from 
 Inverary. 
 
MODE V. PORPHYRY. 
 
 to be one of the Ophites, or snake-stones of 
 Pliny. 
 
 Saussure, and innumerable others, misled me Ophite, 
 concerning the Ophites of Pliny. The passages are : 
 
 Pretiosissimi qu&dam [marmora] generis, sicut 
 Lacedcemonium viride, cunctisque h Harms. Sic et 
 Augustatm, ac delude Tiberianum, in JEgypto, 
 Augusti ac Tiberii primum principatu reperta. 
 Different iaque eorum est ab Ophite, cum sit illud 
 serpent him maculis simile ', unde et nomen accepit ; 
 quod h&c. maculas diverse modo colligunt ; Angus- 
 team undatim crispum in vertices; Tiberianum 
 sparsa, non convoluta, canitie. Nequc e.v Ophite 
 columnte nisi parvtf admodum inveniuntur. Duo 
 ejus genera, rnolle candidum, nigricans durum, 
 xxxvi. 7. edit. Brotier, Paris 1779, 12mo. 
 
 Again, c. 22, speaking of stones used for 
 making mortars. Potiorem ex alabastrite JEgyptw^ 
 vel ex Ophite albo. Est enirn hoc genus Ophitis, 
 ex quo vasa etiam et cados faciunt. 
 
 These passages may be thus interpreted : 
 
 " Some marbles are of a very precious kind, as 
 the green c-f Lacedemon, which is also more cheer- 
 ful than any of the others. So also the Augustean, 
 and afterwards the Tiberian, first discovered in 
 Egypt during the reigns of Augustus and Tiberius. 
 The difference between these marbles and ophite 
 consists in .this, that the latter resembles the spots 
 
SO DOMAIN I. SIDEROUJ. 
 
 of serpents, whence its name is derived ; whereat 
 the marbles display their spots in a different man- 
 ner, the Augustean being crisped into wavy tops, 
 while in the Tiberian the white is scattered, not 
 convolved. Nor can any columns be formed of 
 ophite, except of a very small size. There are 
 two kinds of it, the white being soft, the blackish 
 or grey hard." He then proceeds to state that 
 both were used to appease head-achs, and against 
 the wounds of serpents ; particularly a kind of 
 ophite named Tephria, because it was of the co- 
 lour of ashes ; and also called Memphites, from 
 the place where it was found, being of a gemmose 
 or sparkling appearance. 
 
 The other passage implies that " good mortars 
 may be made of Egyptian alabastrite, or of white 
 ophite, for this is a kind of ophite of which they 
 make even vases and larger vessels.'* 
 
 Lucan also has, 
 
 Quam parvis tinctus maculis Thebanus ophites. 
 <f Like Theban ophites tinged with small spots." 
 
 Pliny is not very accurate, and it is more pro- 
 bable that the ophite came from Thebes in Upper 
 Egypt, than from Memphis. It must however 
 have been wholly remote from green porphyry, 
 being probably the Thebaic stone, mentioned by 
 Theophrastus, of a dark colour sprinkled with 
 
MODE V. PORPHYRY. 81 
 
 golden (Jrops ; that is, as Wad explains, a dark 
 ollite interspersed with golden mica *. The white 
 was probably a spotted marble or alabaster, for 
 the ancients arranged stones by faint resemblances ; 
 but white ollite, or rather massive steatite, is not 
 unknown in Saxony and other countries. 
 
 Green porphyry occurs in large blocks near 
 Ostia, which, as Ferber observes, was the old har- 
 bour where the Egyptian ships unloaded |: but 
 all the other ships bound for Rome also arrived 
 there; nor do I find any mention of green por- 
 phyry in the memoir concerning Egyptian geo- 
 logy, which M. Roziere presented to me. This 
 porphyry contains crystals of siderite, and fre- 
 quently spots of chalcedony. Ferber observed Ferbert 
 
 observations. 
 
 the following varieties : 
 
 Dark green, with fair green spots ; common. 
 Dark green, with white spots. 
 Dark green, with black spots. 
 
 * Fossil. JEgypt. p. 57. This subject will be further illustrated 
 in treating of the Magnesian Rocks, and of the ancient marbles, 
 where it will be seen that the green porphyry was unknown till the 
 latter times of the Roman empire. In describing this substance, 
 Da Costa, p. 288, justly observes, that there are no Grecian nor 
 Roman relics of it ; and he concludes that very little was found even 
 in Egypt. It is now well known that it is not an Egyptian pro- 
 duct ; but vast masses remain near the port of Ostia, where it was 
 probably left on the irruptions of the barbarians in the fifth century, 
 when the arts were interrupted and abandoned. 
 
 f Travels in Italy, 225. 
 VOL. I. G 
 
DOMAIN I. S1DEKOUS. 
 
 Fair green, or yellowish green, with black spots. 
 
 He also mentions a dark green porphyry, ol 
 which the trap base sometimes passes into crystals 
 of siderite ; while the large white crystals of fel- 
 spar are so numerous, that it might be called a 
 white porphyry. 
 
 It is believed that green porphyry of this struc- 
 ture is found in Ireland, and in Cumberland, and 
 also in Norway. 
 
 The ancient was probably found in Thessaly, 
 as will appear in discussing, under one point of 
 view, the Ancient Marbles in Domain V. 
 ftatement Saussure mentions the following : 
 
 A porphyry with a base of greenish grey felsite, 
 with very small crystals of felspar, and some glo- 
 bules of lime ; the presence of the latter in so 
 hard a rock being regarded as singular. 1578. 
 
 A singular porphyry of a chocolate colour, with 
 crystals of blue felspar. 1448. 
 
 Not far from Frejus is a mountain of red por- 
 phyry, with some grains of quajctz. 1453. 
 
 At Esterelle, between Nice and Frejus, are 
 rocks of porphyry, the base being of the colour of 
 wine lees. 1436. 
 
 P DnrSc e e s f ^ e ^ so * ves ^ ie following account of the por* 
 phyries which he observed in pebbles, in the bed 
 of the river Durance, which has been long cele- 
 brated for its variolites. 
 
MODE V. PORPHYRY. 83 
 
 1539. B. " Green porphyry. The cement of 
 this porphyry approaches likewise to that of the 
 ophite *; its colour is however less beautiful : it 
 is a green which verges to the deep grey : it like- 
 wise assumes a surface less uniform and less soft 
 to the touch. In other respects its fracture and 
 hardness are the same, but it is a little more re- 
 fractory, and the glass it yields is less hard and 
 opake. The small fragments of this glass ars 
 however attracted by the magnet. 
 
 " The crystals of felspar which this porphyry 
 contains are, as in the ophite, lengthened oblique 
 angled prisms, of a white inclining a little to green; 
 of an unctuous and milky lustre ; their fracture is 
 more compact, and presents thicker laminae than. 
 common felspar. 
 
 1539. C. " Red porphyry. The cement of this 
 porphyry is of what I call primitive petrosilex. 
 In the rolled pebbles its surface is pretty uniform, 
 almost soft to the touch. It breaks into irregular 
 fragments in sharpish angles, almost opake on 
 their edges. Its fracture is scaly with very thin 
 scales, which, viewed by a microscope, appear 
 semi-transparent and whitish, whilst the base is 
 of a pretty deep wine red. 
 
 * By ophite, Saussure, like many others, erroneously understands 
 the green porphyry. 
 
84 DOMAIN I. SIJDEROUS. 
 
 " This cement is more than semi-hard, it easily 
 gives sparks under steel, and may nevertheless be 
 scratched by a knife, the streak being of a rose 
 colour. It melts with difficulty under the blow- 
 pipe into a semi-transparent glass, grey and full 
 of bubbles, mixed with some brown dots, which 
 are attractable by the magnet. 
 
 " The grains are of felspar, white, yellowish, 
 rarely crystallised with regularity, and of the unc- 
 tuous nature of the preceding. 
 
 1539- D. " Black porphyry. The paste of this 
 is of a fine deep black, approaching a little to 
 blue : its exterior surface is pretty uniform, and 
 almost soft to the touch. Its fracture delicately 
 scaly, as that of the preceding ; but its hardness 
 rather less, although it yields some sparks. It is 
 still more refractory ; the flame of the blow-pipe only 
 whitens and blunts it a little on the thinnest edges. 
 
 " The grains, of a greenish white, have no regu- 
 larity ; they are cemented in the black base of the 
 stone, in all sorts of forms. Their fracture is 
 most frequently scaly: there are however to be 
 seen some marks of the laminar texture of the 
 felspar, and it is also, as in the others, of the unc- 
 tuous kind. 
 
 1539- E. " Brown porphyry. Its cement is 
 brown, rough, and of an earthy aspect ; it is how- 
 ever pretty hard. The grains, seldom regular, are 
 
MODE V. PORPHYRY. 
 
 of an unctuous felspar, a little compact, and of a 
 greenish tint*. 
 
 1539- F. " Grey porphyry with a cement of 
 petrosilexj of a greenish grey, enclosing a number 
 of crystals of unctuous felspar of the same colour, 
 though a little whiter, some pyrites, and some 
 black ferruginous spots. 
 
 1539- G. " Schistose porphyry with a blackish 
 cement the colour of iron, with a scaly atid bril- 
 liant fracture, hard, containing crystals of dry 
 white felspar, opake, which bubbles and readily 
 melts under the blow-pipe, and other crystals of 
 hornblende, pretty hard, of a blackish green." 
 
 Add porphyry with black chalcedony, from 
 Chemnitz, in Saxony. (Linn, a Gmelin, 206.) 
 
 Aspect 4. Blue. Dark indigo blue porphyry, 
 with crystals of yellowish felspar, from the isle of 
 Rasay, Scotland. 
 
 'See Mr. Jameson's Mineralogy of the Scotish 
 Isles, ii. 117. He. says the base is betwixt clay 
 and hornstone, so it is only placed here to excite 
 further enquiry concerning so beautiful and un- 
 common a rock. 
 
 * Verd d'oeillet. The French of Swiss and German authors is 
 ften peculiar. 
 
CO DOMAIN 1, SIDEKOUS. 
 
 STRUCTURE II. WITH SMALLER CRYSTALS. 
 
 Aspect 1. Red. Of Egypt, the felspar being 
 frequently in white or in flesh-coloured prisms ** 
 
 The same, with white only, the porphyry of 
 Pliny. It is sometimes interspersed with masses 
 of a lighter or darker colour. 
 
 The same, from Corsica, from Lesterelle in 
 Provence, Scotland, Sec. 
 
 The same, with crystals of siderite, 
 
 Aspect 2. Brown. Of this Ferber mentions 
 two varieties; the liver brown with light green 
 spots, and the dark brown with spots half black 
 and half green; perhaps he means crystals of 
 black siderite and green felspar. 
 
 Dark brown porphyry, speckled with numerous 
 small crystals of felspar, and others of siderite 
 and quartz, with reddish and green nodules, from 
 Sweden, where it is manufactured and takes a 
 high polish. 
 
 Aspect 3. Black. Entirely resembling the red, 
 except in colour. Of this there are two large 
 columns in a church near the gate of St. Paul, at 
 Rome. 
 
 * Wad, 12. 
 
MODE VI. PORPHYRIN. 8J 
 
 Aspect 4. Green. Resembling the red. 
 
 The same, with crystals of s'iderite. 
 
 From Ferber's description it would seem that 
 the felspar is wanting, in which case it is a trap 
 or basal tin. 
 
 The same, with small crystals of felspar in 
 white spots, commonly irregular, and twisted like 
 worms; the Porfido verdejiorito*. 
 
 The red also occurs in Egyptian monuments, as 
 well as the black f. Green porphyry is also found 
 in Corsica and Norway. 
 
 MODE VI. PORPHYRIN. 
 
 This name has been adopted for porphy- 
 ritic substances, in which the crystals of fel- 
 spar are so small as almost to escape the eye, 
 or not be discoverable without a lens. But 
 somewhat of the regularity of true porphyry 
 must be observable, otherwise the substance 
 must be considered merely as a mingled basaltin. 
 On the other hand, the mixture of a few grains 
 of quartz may be admitted in a porphyrin ; but 
 
 * One kind so called is not a porphyry, but a waved mixture of 
 siderite and felspar, as if daubed with a brush. See Anomalous 
 Rocks. 
 
 t Wad, 12, 13. 
 
88 DOMAIN I. SIDEROUS. 
 
 if the base assume the granitic form, it must be 
 \ regarded as a granitic porphyry. 
 
 The Swedish porphyry, already mentioned, 
 approaches nearer to a porphyrin ; specimens 
 of which are common in most porphyritic re- 
 gions, forming the passage from basaltin to por- 
 phyry. 
 
 MODE VII. PORPHYRON. 
 
 When the crystals of felspar exceed an inch 
 in length, and are distant from each other, cir- 
 cumstances which occur in the large scale of 
 nature, the rock may be termed Porphyron. 
 The utility of these divisions will be more fully 
 understood, as the science becomes more and 
 more studied. 
 
 MODE VIII. PORPHYROID. 
 
 This denomination includes such substances 
 as approach the porphyritic structure. In a 
 strict derivation of the term porphyry, as al- 
 ready explained, the black and green kinds 
 could only be termed porphyroids; but as this 
 severity would too much violate common usage, 
 
MODE IX. AMYGDALITE. 
 
 the term porphyroid, as admitted into the side- 
 rous division, must be restricted to such rocks as 
 have a base of siderite, basalt, or basaltin, pre- 
 senting an appearance of porphyry. Some of 
 the primitive grunsteins of Werner fall under 
 this distribution. When the base is siderous, 
 but the square crystals are barytic or calcareous, 
 &c. this denomination may also be adopted*. 
 The mixtures called granitic porphyroids, &c. 
 are to be arranged under their proper domains. 
 
 MODE IX. AMYGDALITE. 
 
 Where the distinctive characters of a sub- 
 stance vary much, they are omitted, to avoid 
 unnecessary prolixity, especially as they may 
 be found in the common books of mineralogy ; 
 and rocks should be studied in themselves, as 
 well as in books, for the only use of any classi- 
 fication is to assist the memory. 
 
 This substance, the mandelstein, or almond- 
 stone of the Germans, has a base of coarse trap 
 or basal ton, in general black or brown, inter- 
 spersed with nodules or kernels of chalcedony, 
 agate, calcareous spar, zeolite, and green mag- Agates. 
 
 * The green siderite, with crystals of calcareous spar, (Sauss. 
 \. 139, 4to.) may belong to this division. 
 
90 DOMAIN I. STDEROUS. 
 
 nesite, or magnesian earth mingled with iron*. 
 The agates afford valuable materials for manu- 
 facturers ; and the rock abounds in many coun- 
 tries, as at Oberstein on the Rhine, Kinnoul and 
 other places on the river Tay, in Scotland, 
 whence the English lapidaries have called the 
 latter agates Scotch pebbles f. In the north of 
 Italy the same rock presents chalcedonies, which 
 are sometimes enhydrous, or contain a drop of 
 water. In the Faroe isles the chalcedony com- 
 , monly assumes the stalactitic form ; and, as 
 Landt observes J, it has been found modelling 
 itself on straw or moss, whence it clearly appears 
 to have been deposited by water; either heated 
 by its own caloric (for if water contained no 
 principle of heat it would become ice), or by 
 subterraneous fires, as the fountain of Geyser in 
 Iceland deposits silicious concretions. 
 Formations. Werner considers Amygdalite as of two form- 
 ations ; the Transitive, the base of which he calls 
 wacken, an argillaceous rock, sometimes inclin- 
 ing to basaltin, which it generally accompanies, 
 and sometimes to iron-stone, a mixture of iron 
 
 * This may also be called a lole, a shorter word than lithomarga, 
 and expressive of the same substance, as appears from the analyses. 
 
 f This name seems also a distinction from the English pebbles 
 in pudding-stone, &c. some of which are as beautiful as agates. 
 P. 146. 
 
MODE IX. AMYGDAL1TE. C; [ 
 
 and clay, which is also the chief repository of 
 prehnite. The other formation belongs to his 
 Floetz, horizontal, or stratiform rocks ; and he 
 also describes the base of this as being wacken, 
 or rather decomposed grunstein, which, accord- 
 ing to his theory, generally lies under basaltin 
 and above clay. But Mr. Jameson, to whom 
 we are greatly indebted for an exposition of the 
 Wernerian system, omits amygdalite in his de- 
 scription of wacken ; and Brochant regards the 
 base of amygdalite as a decomposed siderite or 
 grunstein, and it certainly belongs to this do- 
 main. It is believed that olivine, though fre- 
 quent in basaltin, has never been observed in 
 amygdalite, in which the silicious parts assume 
 a different form. 
 
 Some French mineralogists have supposed Origin, 
 amygdalite to be of volcanic origin ; but Patritt, 
 though an ardent volcanist, has rejected this 
 idea, and arranges it after porphyry, as he ob- 
 serves that the base is sometimes siderite, some- 
 times trap. The cavities are also larger than 
 any found in lava; and though agates be so 
 named from the river Achates in Sicily (in the 
 south of that country, and at a great distance 
 from Etna), it appears not that agates have ever 
 been observed in any volcanic region. 
 
 Amygdalite, like basalt, often contains no* 
 
DOMAIN I. 5IDEROUS. 
 
 dules of common steatite, and small crystals of 
 siderite. As it only takes a very coarse polish, 
 the base is properly a basalton. 
 
 STRUCTURE I. AMYGDALITE WITH AGATES. 
 
 From Oberstein on the Rhine. 
 
 The same, with cubic zeolite. 
 
 The same, with veins of glassy chalcedony, ac- 
 companied with a band of the colouring matter, 
 which would form agate. 
 
 Brown amygdalite, from the same. 
 
 Amygdalite, with chalcedony, zeolite, &c. from 
 the Isle of Skey. 
 
 Faujas has given a good list of the products of 
 Kinnoui. Kinnoul, but ridiculously calls them lavas. He 
 mentions black basaltin joined to basal ton, the 
 latter presenting small crystals of felspar, so as to 
 assume a porphyritic appearance. The same com- 
 pact basaltin, in columns. Green basalt, very 
 firm and sonorous. Basalt with crystals of fel- 
 spar, and attracting the magnet. A square prism 
 of the same, with a carnelian on one of the sides. 
 The same, with globules of green earth, agate, and 
 calcareous spar, &c. 
 
 Moca. Beautiful agates, or what are called moca- 
 
 stones, also occur in a rivulet called May, which 
 falls into the Era near the house of Condie, in 
 
MODE IX. AMYGDALlTE. 
 
 Perthshire. Moca-stones are also said to be 
 found on the banks of the Tweed, being chalce- 
 dony mingled with green earth, bitumen, &c. in 
 the form of moss, and other appearances. They 
 receive their name from Moca, in Arabia ; that is, 
 like many other substances, not from their native 
 site, but from the mart where they were sold, 
 being brought to Moca from Cambaya in Hin- 
 dostan, which also transmits beautiful carnelians 
 and chalcedonies*. There are probably rocks of 
 amygdalite in that vicinity. It would appear 
 however that this rock is among the rarest pro- 
 ducts of nature, having seemingly been observed 
 only in the four countries above mentioned ; Hin- 
 dostan, Sicily, Scotland, and the neighbourhood 
 of Ober stein. 
 
 STRUCTURE II. AMYGDALITE WITH CALCAREOUS SPAR. 
 
 Of this the toad-stone of Derbyshire affords Toad-stone, 
 a well-known example. Patrin mentions another 
 
 * It is said that the fine carnelian is produced by art from no- 
 dules of a kind of chalcedonic flint, which are left in the heat of 
 horse-dung for many months. One of these flints I received from 
 my highly-respected friend Mr. Ferguson, whose noble collection of 
 minerals is known to all Europe. But, in the oriental phrase, his 
 lore of science, and generous spirit, surpass all the gems in his 
 cabinet. 
 
94 DOMAIN I, S1DEKQUS. 
 
 from Strelka, in Siberia, with crystals -of felspar 
 
 and globules of steatite, in a base of liver-coloured 
 
 VarioHte of trap. The variolite of the Drac, a torrent which 
 
 Drac. 
 
 throws itself into the I sere beneath Grenoble, also 
 belongs to this division. The base, according to 
 Patrin, is of trap, mingled with clay, or what the 
 German mineralogists would call a wacken, being 
 of a grey or violet colour, with spangles of felspar 
 and globules of calcareous spar; sometimes also 
 with globules of green steatite. In like manner the 
 toad-stone of Derbyshire is occasionally, though 
 rarely, of a light brown colour, with green spots. 
 Saussure regards the variolites as primitive rocks; 
 but Werner only classes them as either transitive 
 or stratiform. 
 
 Black amygdalite, or toad-stone, from Derby- 
 shire. 
 
 The same, with veins or nodules of red jasper. 
 
 Dark brown toad-stone, from the same. 
 
 Light brown, or fawn-coloured toad-stone, with 
 green globules, from the, same. 
 
 Variolite of the Drac, the Hartz, c. 
 
 The calcareous spar sometimes decomposes, 
 and leaves a false appearance of lava. 
 
MODE X. IRON-STONE. 
 
 STRUCTURE III. AMYGDALITE WITH OPEN PORES. 
 
 This substance abounds in the high upland of 
 Mexico, where it is of a reddish colour, and is the 
 tetzontli used in building. As that region abounds 
 with volcanoes, it is probably a lava. 
 
 MODE X. IRON-STONE. 
 
 Texture, compact, granular or earthy, some- characters, 
 times undulated. On the surface of English 
 hills composed of this substance, it often pre- 
 sents a singular ornamented appearance, as if 
 derived from pinnae, or some other long py- 
 ramidal shell, with transverse bars ; and is some- 
 times covered with yellow rust from the decom- 
 position of the iron. 
 
 Hardness, basaltic. Fragments, amorphous, 
 rather sharp. 
 
 Weight, siderose. 
 
 Lustre, dull, opake. 
 
 This substance forms many small chains of sues. 
 hills in England, as in Surry, &c. and in other 
 countries, yet has scarcely been identified in 
 books of mineralogy. Ferber, in his_ orycto- 
 graphy of Derbyshire, mentions iron-stone as 
 
BOMAIN 1. SIBEROUS* 
 
 composed of a bluish heavy clay, with an ap- 
 pearance of containing much iron ; he also men- 
 tions a brown kind, found in the coal-mines of 
 Stansby. This rock contains from 20 to 40 of 
 iron, and when rich in that metal is worked as 
 an ore ; being a Gemeiner Thoneisenstein of Wer- 
 ner, which contains about 40 parts of iron in the 
 100. But none are here intended to be included 
 which exceed 20 or 25. It is supposed gene- 
 rally to indicate coal; and if so, that mineral 
 may be expected in Surry. The clay-stone, or 
 argillaceous iron-ore, has commonly a brown or 
 red appearance; while this is grey or black, 
 and probably contains no more iron than basalt. 
 The name iron-stone is commonly used in Surry 
 and other counties ; but it probably is one of 
 the vague whins of the North. It is o.i the 
 gangart of prehnite*'. 
 
 STRUCTURE I. OMPACT. 
 
 Iron-stone, from Surry, Shropshire, &c. 
 
 The same, with prehnite, from Dunbarton, Sec. 
 
 * Mountains of iron-stone exist in the East, if we credit Arab, 
 Rights, vi. 23& of Dr. Scott's edit. 1811. 
 
MODE X. IRON-STONE. ,97 
 
 STRUCTURE II. COLUMNAR. 
 
 Mr. Sowerby possesses in his valuable museum 
 a curious example of this kind, being quadrangular 
 columns of iron-stone passing through slate. 
 
 STRUCTURE III. VARIEGATED. 
 
 This kind, with an appearance of shells, &c. 
 has been already mentioned. 
 
 The rock upon which the Capitol of Rome was 
 founded, is thus described by Breislak. 1. The 
 colour is brick red, but with spots of a deeper 
 tinge, and which are also of a larger grain. 2. Its 
 hardness surpasses that of tufa, but is inferior to 
 that of lava, being comparable with that of the 
 freestone used at Paris. 3. If large pieces be 
 broken off with the hammer, the fracture is even 
 conchoidal ; in small the fracture is unequal, small 
 grained, but never rough. 4. It acts on the mag- 
 netic needle at the distance of two or three lines. 
 5. It contains scales of mica, fragments of felspar, 
 and white globules of calcareous spar, with some 
 fragments of melanite. 6. Observed in the sun 
 with a good lens, the whole mass is found to be 
 crystallised. 
 
 If this rock be not a red basalt, it may pass 
 
 VOL. I. H 
 
98 DOMAIN I. SIDEROUS. 
 
 into the Mode of Iron-stone, as appears from its 
 action on the magnet. 
 
 The stone which serves as a gangart to the 
 quartz crystals called Bristol diamond, may also 
 be ranked in this division ; but it seems to be only 
 a vein-stone passing through limestone. Various 
 kinds of iron-stone, siliceous and argillaceous, 
 often occur in mines, but have not been found to 
 constitute rocks. 
 
 The following substance may also be added to 
 this division. 
 
 Iron clay of ct Tiv\n ^Ta-tr 
 Werner. lron cla j- 
 
 " Eiseathom. Werner. 
 
 " External Characters. 
 
 " Its colour is commonly brownish red, which 
 seldom approaches to blood red, but more often 
 to reddish brown. 
 
 " Occurs almost always vesicular, sometimes 
 with empty, sometimes with filled vesicles. 
 
 " Internally it is dull. 
 
 " Fracture fine, earthy, sometimes inclining to 
 conchoidal. 
 
 " Fragments indeterminately angular. 
 
 " Is soft, but sometimes passes into semi-hard. 
 
 " Is not particularly difficultly frangible. 
 
 " Not particularly heavy, in a middling degree. 
 
MODE XI. JASPER. 99 
 
 " Geognostic Situation. 
 
 " It belongs to the floetz-trap rocks, and con- 
 stitutes, like wacken, the basis of amygdaloid. 
 
 " Observations. 
 
 " It is distinguished from wacken by its colour, 
 and the greater proportion of iron which enters 
 irito its composition. 
 
 "2. The iron which it contains is very much 
 oxydised, whereas that in basalt is slightly oxyd- 
 ised."* 
 
 MODE XI. JASPER. 
 
 Texture, very fine grained and compact, some- Characters, 
 times rather earthy. 
 
 Hardness, crystallie, sometimes only felsparic. 
 Fracture, conchoidal. Fragments, angular sharp. 
 
 Weight, sometimes siderose, sometimes grani- 
 tose. 
 
 Lustre, glistening, rising to shining, but some- 
 times dull. Opake; sometimes translucent on 
 the edges, but it then passes to jaspagate. 
 
 The most frequent colour of jasper is the red, 
 which has been found to contain from 16 to 20 
 
 * From the additions to Mr. Jameson's Mineralogy, ii. 603. 
 
 ii 2 
 
100 DOMAIN I. SI1>EROUS. 
 
 of iron, and often attracts the magnet. It is 
 surprising that analyses have not been made of 
 a substance regarded as valuable. 
 
 Basanite* Basanite, or the Lydian stone, is by many 
 regarded as a black jasper, seemingly with rea- 
 son, for its geognostic relations in veins, &c. 
 resemble those of the other jaspers, and small 
 veins of quartz often traverse both kinds, 
 whitejasper. The existence of white jasper has recently 
 been granted; but even this colour does not 
 refuse the presence of abundant iron, as may be 
 observed in the white ore of iron called steel ore, 
 or the spary iron ore, which is found to contain 
 from 30 to 40 of iron, with more than 20 of 
 manganese. 
 
 The black being admitted, jasper maybe said 
 to present all colours, except blue, which seems 
 however to occur in New Spain, or at least a 
 green approaching nearly to blue. The sinople, 
 or red jasper of Hungary, sometimes contains 
 gold*; and is said by Born to hold 18 of iron. 
 When Mr. Kirwan argues against this, from 
 the comparative lightness, he forgets that many 
 ochres, and even ores of iron, are comparatively 
 light; nor is that metal itself of great specific 
 
 * The sinople of Heralds is green ! The earth of Sinope (see 
 Pliny) was red. 
 
MODE XT. JASPER. 101 
 
 gravity, being much inferior even to tin or 
 copper. 
 
 " Mountains of striped jasper occur in Siberia, sites, 
 and often with breccias, but without petrifac- 
 tions, per Herman. 1 Berg. Jour. 1791, p. 84 
 and 94; of red jasper, ibid. 88; and also of 
 green jasper, 2 Gmelin. 81. (French.) It often 
 forms thick strata in mountains of schistose mica 
 in the Apennines, Ferber, Italy, 109 ; and in 
 Siberia, 2 Herm. 281. In Saxony it is found 
 alternating with, and sometimes mixed with, 
 compact red iron-stone, 2 Berg. Jour. 1788. 
 485. 
 
 " In the south of France it occurs, reposing 
 on granite, and underlaying basalt, 3 Soulavie. 
 72. In the Altaischan Mountains it has never 
 been found in contact with granite, but it some- 
 times underlays argillite. 6 Nev. Nord. Beytr. 
 115."* 
 
 At Salisbury Crags, near Edinburgh, a curious 
 jasper, spotted with metallic iron, occurs under 
 the basalt. Saussure and Dolomieu have ob- 
 served that jasper is chiefly of an argillaceous 
 nature, more or less penetrated with oxyd of 
 iron. Patrin has given an interesting account 
 of the mountains of jasper in Siberia f, where he of Siberia. 
 
 * Kirwan, G. E- 177. t ii. 266. 
 
DOMAIN I. SIDEROUS. 
 
 conceives that what he calls petrosilex passes 
 into jasper, by the influence of the atmosphere ; 
 but in this he judges from the colours, and not 
 from the analysis. His primitive petrosilex, as 
 he declares, is felsite, while he places jasper, 
 which he calls primitive, after his secondary pe- 
 trosilex, which he expressly mentions is the 
 hornstein of Werner. There is therefore great 
 confusion in his context, as he derives a primary 
 rock from a secondary substance ; and his pe- 
 trosilex must be itself regarded as a dull and 
 imperfect jasper; nor is it inconceivable that 
 the surface may even attract more iron from the 
 atmosphere, where atoms of that substance con- 
 stantly float, as has appeared from many experi- 
 ments and inferences. The most beautiful jas- 
 pers of Siberia appear on the eastern side of the 
 southern part of the Uralian chain, particularly 
 the ribbon jasper, green and red, and that spot- 
 ted with pitchstone, or perhaps brown jasper. 
 Another beautiful kind presents, on a bright red 
 base, little undulating veins of olive green, ac- 
 companied by a white thread which follows all 
 the undulations. In Daouria, on the left bank 
 of the river Argun, one of the sources of the 
 Amur, there is a famous mountain composed of 
 green jasper; but, like the other kinds, it will 
 not rise in large pieces, but splits into smallfrag- 
 
MODE XI. JASPER. ]Q3 
 
 ments. He observes that jasper is generally 
 schistose. A late traveller has informed us that 
 mountains of jasper extend for perhaps more 
 than a thousand miles through the eastern part 
 of Siberia, including Gore Island, between that 
 country and North America. On the contrary 
 the grand chains of European mountains seldom 
 or never present this substance ; which is chiefly 
 found in Sicily, Bohemia, and Saxony. 
 
 It must be observed that many of the jaspers 
 rather belong to lithology or gemmology, being 
 only found in geods or small veins. Nor is it 
 intended to be affirmed that they all belong to 
 the siderous domain, though the black, the red, 
 and the green, which are found in the greatest 
 abundance, appear always to belong to that di- 
 vision ; and it may be observed that these co- 
 lours also occur in basaltin, like which also jas- 
 per occurs in columns at Dunbar, in Scotland. 
 
 STRUCTURE I. COMMON. 
 
 Aspect 1. Black jasper. It is doubtful whether 
 this substance, the basanite or Lydian stone of 
 Werner, form entire mountains, though Kirwan 
 seems rather to imply that it does: but the sili- 
 ceous schistus of Werner, which includes basanite, 
 is so vague an appellation as to convey no idea ; 
 
104 DOMAIN I. SIDEROU5. 
 
 and the application of the term has embarrassed 
 even the most skilful mineralogists. 
 
 Black jasper, from Prague. 
 
 The same, from Leipsic. 
 
 The same, from Hainchen, near Freyberg, in 
 Saxony. 
 
 The same, from the Pentland hills, near Edin- 
 burgh*. 
 
 Aspect 2. Red jasper, from Saxony. 
 
 The same, with granite adhering to both sides, 
 from the Spizleite, near Schneeberg. 
 
 Red jasper, or sinople, with grains of gold, 
 from Hungary. 
 
 The same, from Siberia, where it rises in moun- 
 tains |. 
 
 Aspect 3. Green jasper, from Daouria, where 
 it composes a mountain. 
 
 Aspect 4. Striped jasper. In green and red 
 stripes, from Siberia, where it forms a chain of 
 mountains. 
 
 * Brongniart, 1. 327, regards the siliceous schistus of Werner as 
 a schistose jasper. He might rather, with Faujas, have called it 
 black jasper, most jaspers being schistose. As iron forms the 
 dominant principle of jasper, and black is the most usual colour of 
 its compounds, it would be absurd to reject black jasper. 
 
 f German and Dutch travellers sometimes call red jasper coral. 
 
MODE XII. SLATE. 105 
 
 Brown jasper, it is believed, may also form 
 mountains or rocks ; but' the other kinds, as the 
 Egyptian, the jaspagate, &c. are only found in 
 small pieces, commonly globular. 
 
 STRUCTURE II. COLUMNAR. 
 
 This structure is very rare, and scarcely occurs 
 except at D unbar, in the south of Scotland, where 
 the interstices of the pillars are filled with sili- 
 ceous cement. 
 
 MODE XII. SLATE. 
 
 Texture, eminently schistose or slaty, com- Characters, 
 monly straight, sometimes curved or undulating, 
 of a very fine or impalpable grain. 
 
 Hardness, from marmoric to basaltic. Frag- 
 ments, sharp, splintery, sometimes rhomboidal. 
 
 Weight, granitose. 
 
 Lustre, sometimes dull, sometimes silky. 
 Opake. 
 
 The colour is most generally bluish, but some- 
 times greenish, or a purple red; also yellowish, 
 and sometimes with stripes or spots of a darker 
 colour. It is the thonschiefer, or clay-slate, of Names. 
 Werner, the argillaceous schistus of many English 
 
106 DOMAIN I. SIDEROUS. 
 
 and French mineralogists, being by all ranked as 
 a primitive rock. As it has been found to con- 
 tain from 14 to 20 of iron, it strictly belongs to 
 this domain, the clay being a very inferior con- 
 sideration. It has also a metallic appearance 
 and sound, very different from schistose clay or 
 clay-slate, strictly to be so denominated. The 
 simple term SLATE, besides the advantage of 
 being in general use, has been thought sufficient 
 to discriminate it by way of eminence. It ge- 
 nerally contains a portion of magnesia; and 
 when this is abundant, as appears to be indi- 
 cated in those kinds which have a very silky or 
 satiny appearance, it may be ranked among 
 the magnesian rocks. It often presents pyrites, 
 either in a cubic or dundritic form, sometimes 
 schorl, and even garnet and siderite. Actinote 
 also appears ; and a recent discovery chiastolite, 
 or hollow spar. Scales of mica often occur, as 
 in many other substances; nay it sometimes 
 passes into mica-slate : and Daubuisson has de- 
 monstrated, by an operose chemical analysis, 
 that they may be regarded as different modes of 
 the same ingredients. 
 
 It often forms entire mountains, but com- 
 monly only a part, alternating with gneiss and 
 mica-slate : nay, according to Kirwan and Pal- 
 las, both granite and gneiss often rest upon slate. 
 
MODE XII. SLATE. 
 
 107 
 
 Sometimes veins of granite are found to pass 
 through this substance, which must not be ac- 
 cepted as only appearing in the finer form used 
 for slates, but also in coarse and thick schisti, 
 and sometimes, though rarely, even massive. 
 
 It is doubtful whether the yellow argillaceous 
 schistus, which composes the famous mountain 
 of Potosi, belongs to this description ; as the Potosi. 
 argillaceous schistus, or the clay-slate of many 
 other countries, so remarkably metalliferous, 
 cannot be classed under this division; which 
 further evinces the utility, if not necessity, of a 
 far greater abundance of definitive denominations 
 in this new science. But Helms seems to con- 
 sider the Andes as chiefly composed of what 
 Kirvvan calls primeval blue argillite ; and he de- 
 scribes the yellow slate of Potosi as being ex- 
 tremely hard. If they contain from 10 to 20 of 
 iron, they belong to this division ; and as iron 
 commonly accompanies the richest ores, it is 
 probable that its presence is here indicated. 
 But Humboldt regards that amazing chain of 
 mountains as chiefly composed of what is called 
 argillaceous porphyry ; while those of New Spain 
 are of argillaceous schistus: roofing-slate, and 
 its correlatives, being regarded as rare. 
 
 There are valuable quarries of slate in Corn- Quarries, 
 wall, Wales, Westmoreland, and Scotland. A 
 
JOS DOMAIN I. SIDEROUS. 
 
 curious account of the manner of working those 
 of France, near Angers, may be found in the 
 Journal des Mines. 
 
 In his account of the primitive schisti, Patrin 
 has the following article*: 
 
 Slate of Ural. " Ferruginous schistus. This slate is mostly 
 composed of hardened clay, abundantly mingled 
 with an oxyd of iron, either black or brown, 
 sometimes red or yellow; a little quartz; and 
 much mica. This rock is one of the most com- 
 mon in the northern countries, where iron is 
 singularly abundant. The eastern part of the 
 Uralian chain of mountains, for an extent of 
 about 500 leagues from north to south, is almost 
 entirely composed of this rock." 
 
 The same able author gives the following ac- 
 count of the slate-mines at Charleville on the 
 Meuse, which he regards as primitive; and 
 afterwards of those of Angers, considered by 
 him as secondary. 
 
 " The slate-mines of Charleville are not ex- 
 plored by open quarries, like those of secondary 
 slate, but by subterranean galleries, because the 
 roof of the bed of slate is composed of banks 
 of quartzose schistus, very hard and very thick ; 
 and besides, the slate plunges very rapidly under 
 
 i, 120. 
 
MODE XII. SLATE. 109 
 
 this rock, which would render enormous clear- 
 ages necessary, and would expose the workmen 
 to great danger from falls of the rock. 
 
 " The principal slate-mine of this country is 
 that of Rimogne, four leagues to the west of 
 Charleville. It is in a hill, of which the centre 
 is primitive, but the skirts are in part covered 
 with beds containing shells. The mouth of the 
 mine is towards the summit ; the bed explored 
 inclines forty degrees to the horizon, so that to 
 advance four feet, you must descend about three 
 feet perpendicular. The workmen call this bed 
 the plate, on account of its form, which is flat 
 and thin, if the extent be considered. Its thick- 
 ness is nevertheless sixty feet ; but its length and 
 breadth are incomparably greater, and their li- 
 mits remain unknown. It has been pursued, by 
 a principal gallery, to the depth of 400 feet j 
 and they have driven many lateral galleries, 
 which are prolonged about two hundred feet, 
 on each side of the main gallery; where are , 
 placed, in succession, twenty-six ladders, for the 
 passage of the workmen, and the carriage of the 
 slate. 
 
 " But in this thickness of 60 feet, there are 
 only 40 of good slate : the remaining 20 of the 
 underpart are full of quartz, and unmanageable. 
 The rock, which forms the immediate roof of the 
 
]]() DOMAIN I. SIDEROUS. 
 
 slate bed, is a granular quartzose schistus, called 
 grit by the workmen ; while the other upper 
 beds are of a friable clay-slate, of an iron colour. 
 
 " This bed of slate is the most considerable 
 known in the country, and I doubt if any similar 
 be found elsewhere. The slate resembles that 
 of Angers, in its quality, and its deep blue co- 
 lour. 
 
 " That of the other quarries in the environs 
 of Charleville is subject to be mingled with py- 
 rites, and intersected in all directions by veins 
 of quartz, which are called cordons. The slates 
 of s6me mines are greenish, like those of certain 
 quarries in the Pyrenees. 
 
 * c In order to quarry these slates they cut out 
 blocks about 00 pounds in weight, which are 
 ealled^/tfz>. Every workman in his turn carries 
 them on his back to the very mouth of the pit, 
 mounting with infinite labour the twenty-six 
 ladders of the great gallery, or at least a part, ac- 
 cording to the depth of the bed. When brought 
 to the working place, these blocks are first split 
 into thick tables, which are called repartom ; 
 this operation is easy: the workman holds the 
 block between his legs, puts a chissel any where 
 to the side, and divides it with the blow of as 
 mallet. The repartom are treated in the same 
 way ; he only takes care when they become too 
 
MODE XII. SLATE. Ill 
 
 thin, to break them in two, by their breadth, in 
 order to prevent their fracture. These operations 
 must be performed soon after the blocks are 
 drawn from the quarry ; for if the stone has time 
 to dry, it would no longer be possible to split it. 
 
 " The engineer Vialet, who has given a me- 
 moir on this slate-mine, says he found a mean 
 of giving these slates double their natural hard- 
 ness, which was by baking them in a brick-kiln, 
 till they had assumed a red colour. In this case 
 they are not more brittle than before; but as 
 they acquire great hardness by this process, as 
 indeed any argillaceous substances will do, they 
 ought to be formed and pierced before they are 
 put into the oven. 
 
 " It is surprising that the slate of Rimogne 
 presents no vestige of marine bodies, while the 
 neighbouring lands are full of them ; but this 
 surprise will cease, when it is observed that na- 
 ture has formed the different portions at epochs, 
 and under circumstances, widely different."* 
 
 Nor is his account of the slate quarries of An- 
 gers less interesting, which he places among the 
 secondary, and regards as far more rare than the 
 primitive. 
 
 " France possesses many of these large beds 
 
 * Patrin Min, iii. ZW. 
 
DOMAIN I. S1DEROUS. 
 
 of slate, chiefly near Laferriere in Normandy, 
 and in the neighbourhood of Angers. The last 
 is the most important; it furnishes slate of the 
 most perfect quality; and its extent and pro- 
 digious thickness make it be regarded as in- 
 exhaustible. 
 
 " This bed extends for a space of two leagues, 
 from Avrille to Trelaze, passing under Angers, 
 where the Mayenne, which comes from the 
 north, cuts it at right angles. 
 
 " The town of Angers is not only covered but 
 built with slate, those blocks being employed in 
 masonry which are the least divisible. 
 
 " The quarries which are actually explored 
 are all in the same line, from west to east, as 
 well as the ancient pits; it being in this di- 
 rection that, by the exterior disposition of the 
 soil, the bed of slate presents itself nearest the 
 surface. Immediately under the vegetable earth 
 is found a brittle kind of slate, which, for four 
 or five feet in depth, splits into little fragments 
 of some inches, which have the form of a rhom- 
 boid, or a portion of that figure. 
 
 " A little lower is found what they call build- 
 ing stone, being a pretty firm slate, but scarcely 
 divisible into leaves. This is employed in the 
 construction of houses, after it has been suffi- 
 ciently hardened by^being dried in the open air. 
 
MODE XII. SLATE. 
 
 " At fourteen or fifteen feet from the surface 
 is found the good slate, which has been quarried 
 to the perpendicular depth of about 300 feet, 
 the remaining thickness being unknown. 
 
 " The operations are conducted by open quar- 
 ries, by successive foncees, trenches, of about 
 nine feet deep, gradually narrowed, in order to 
 preserve a slope sufficient to prevent lapses of 
 the rock ; so that a trench, four hundred feet in 
 width at the opening of the quarry, shall be re- 
 duced to nothing at the thirtieth foncce, that is 
 the depth of 270 feet. There is every reason to 
 presume that a far greater depth might be at- 
 tained, and with more advantage, as the lower 
 they have gone the more perfect is the slate. 
 They have only been stopped by the difficulties 
 presented by the method of quarrying hitherto 
 adopted, which appears not to have been the 
 best, in one respect particularly, which is, that 
 the quantity of slate diminishes as the quality 
 becomes better, so that in the total mass those 
 of a middling quality are far more numerous. 
 It would seem that the method of subterranean 
 galleries would prevent the inconveniencies bf 
 the present plan ; there would not at least be 
 lost and overwhelmed a prodigious quantity of 
 excellent slate. The slate-mines of Charleville 
 might serve as an example; where, in spite of 
 
 VOL. i. i 
 
H4 DOMAIN I. SIDEEOUS. 
 
 the disadvantageous situation of the bed, which 
 renders it more difficult to be worked than if it 
 were horizontal, the product amply repays the 
 undertakers, though the galleries be of great 
 length, and some even pass under the river 
 Meuse. Slate is far more valuable than coal ; 
 and yet all mines of the latter are explored by 
 pits and galleries, sometimes of immense depth : 
 those of Charleroi, in the Netherlands, are about 
 two thousand four hundred feet in perpendicular 
 depth j those of Whitehaven, in England, about 
 five thousand, while they extend more than half 
 a league under the sea. But works conducted 
 with skill overcome the difficulties which are 
 produced by these subterraneous excavations, 
 which are repaid with great profit, and no part 
 of the mineral treasure is lost. It would there- 
 fore be of great consequence to try if the method 
 of galleries could not be adopted at Angers. 
 
 " As to the interior structure of this great 
 mass of slate, it is divided by many veins of cal- 
 careous spar and quartz, about two feet thick, 
 by fifteen or sixteen in height ; they are parallel 
 amongst themselves, and proceed regularly from 
 west to east, in a situation which approaches 
 the vertical, as they only decline seventy de- 
 grees towards the south. These veins are met 
 at intervals by similar veins, whose directiom is 
 
MODE XII. SLA.TB. 115 
 
 the same ; and of which the inclination is also 
 seventy degrees, but in an opposite sense, so that 
 when they meet the former they either form 
 rhombs, or half rhombs, which Guettard com- 
 pares to the letter V; some being upright, while 
 others are reversed. 
 
 " All the layers or leaves of the slate have a 
 direction and inclination similar to those of the 
 first veins of quartz; that is to say, that they 
 rise seventy degrees towards the south, and dip 
 towards the north : and even when intersected 
 by veins which have an opposite inclination, 
 theirs is not changed. The whole mass is thus 
 divided into immense rhomboids, composed of 
 plates all parallel amongst themselves, and with 
 the two opposite faces of the rhomboid. 
 
 " The slate of Angers is extracted in blocks 
 of a fixed size, which are divided, as at Charle- 
 ville, into repartons and leaves. It is betwixt 
 these leaves that there are frequently found ves- 
 tiges of marine animals, and above all pyritous 
 impressions of pous-de-mer (the sea-louse, a little 
 univalve shell of the courie kind) ; of little che- 
 vrettes (shrimps or prawns); and a kind of crab, 
 of which the body is about a foot in breadth, 
 and fourteen or fifteen inches in length, the tail 
 having nine or ten rings. The shrimps are 
 sometimes so numerous, that Guettard counted 
 
116 
 
 DOMAIN I. SIDEROUS. 
 
 forty upon a slate of only one foot square. But 
 it must be observed that none of the above ani- 
 mals have similar representatives in living zoolo- 
 gy. But what appears most surprising in these 
 impressions, particularly with regard to the large 
 crabs, is, that the body, though there be no sign 
 of its being crushed, may be said to have no 
 thickness whatever. They are rather simple 
 engravings than bodies in relievo, the convexity 
 of these large crabs upon a thin leaf of slate not 
 exceeding the quarter, or even the tenth part, of 
 a line ; nor is it perceivable that the body of the 
 animal at all penetrates the thickness of the leaf 
 where it is adherent. And what still adds to 
 this wonder, is the nearly vertical situation in 
 which these impressions are found in the mine. 
 " A series of leaves of slate may be compared 
 to a set of books placed upon shelves ; and the 
 impressions of crabs and other animals, to en- 
 graved plates in the volumes. They do not, in 
 fact, occupy more thickness; and it is equally 
 difficult to conceive how the body of these ani- 
 mals, though otherwise perfectly defined, should 
 be reduced to a simple surface without thick- 
 ness : and how it should always be found in a 
 vertical situation, which cannot be ascribed to 
 any derangement in the bed itself, since it is 
 still horizontal, and occupies a space of many 
 
MODE XII. SLATE. 
 
 leagues. The difficulty of supplying such phe- 
 nomena has led some to imagine a plastic force 
 in nature, a power of modelling, in the mineral 
 kingdoms forms analogous to those of organised 
 bodies. 
 
 " These slates also often present beautiful py- 
 rites in the form of trees, more than a foot in 
 extent, which are regarded by Guettard as im- 
 pressions of tremellte. The pyrites is sometimes 
 in small grains, disseminated like a dust upon 
 the surface of the slates ; where may also be ob- 
 served many little stars of selenite. 
 
 " When the blocks have been drawn from the 
 quarry, if they be left exposed to the sun or to 
 the open air for some days, they lose what is 
 called the quarry-water, become hard and un- 
 tractable, so that they can only be employed in 
 building. Frost produces a singular effect on 
 these blocks : while frozen they may be divided 
 with more ease than before; but if thawed a 
 little quickly, they are no longer divisible. Yet 
 this quality may be restored by exposing them 
 once more to frost; but if the alternative be 
 often repeated, it becomes impossible to reduce 
 them to leaves. 
 
 " The secondary slate which is found in other 
 countries, offers nearly the same dispositions and 
 
118 DOMAIN I. SIDEEOU6. 
 
 phenomena as that of Angers. It is a substance 
 as rare in other countries as in France, there 
 being only one or two quarries in England, in 
 the county of Caernarvon. Switzerland presents 
 no slate, except in the valley of Sernst, in the 
 canton of Claris. 
 
 " Italy has only one slate-quarry, that of La- 
 vagna, in the state of Genoa, which furnishes a 
 slate of an excellent quality, and so impene- 
 trable to fluids, that it serves to line the cisterns 
 in which olive-oil is preserved. 
 
 " Germany presents many kinds of secondary 
 slate (clay-slate), containing impressions of rep- 
 tiles, fish, and other animals ; but these impres- 
 sions have a considerable relievo, aiid it is evi- 
 dent that the animal has existed. The most 
 remarkable of these slate-quarries are those of 
 Eisleben, in Saxony; of Ilmenau; of Mansfeld, 
 in Thurirjgia; and of Pappenheim, in Franconia, 
 I have often seen, in the mountains of Siberia, 
 beds of primitive slate, more or less considerable; 
 but they are mostly aluminous, and furnish the 
 kamennoie maslo, or rock butter, a fat yellowish 
 substance of a penetrating smell, being a mix- 
 ture of alum and fluid bitumen. But I have no 
 knowledge rhat in all this immense country there 
 ip one bed of secondary slate. Nor does Bowles, 
 
MODE XII. SLATE. 
 
 in his Natural History of Spain, indicate that 
 he has observed any in that kingdom*." 
 
 To these accounts may be subjoined a short 
 description of a remarkable quarry in Cornwall, 
 unknown to Patrin. 
 
 " Between Liskeard and the Tamar, on the 
 south-west, are some quarries of slate, which 
 supply the inhabitants of Plymouth with cover- 
 ing for their houses, and for the purpose of 
 exportation. Several quarries have also been 
 opened at other places ; but the best covering- 
 slate in Cornwall, or perhaps in England, is pro- 
 cured at Denyball, nearly two miles south of 
 Tintagel, in the north part of the county. The 
 whole quarry is about 300 yards long, 100 
 broad, and almost 40 fathoms in depth. The 
 slate-rock is disposed in strata, dipping to the 
 south-west, and preserving that inclination from 
 top to bottom. It is first met with at about 
 three feet below the surface of the ground, in a 
 loose, shattery state, with short and frequent 
 fissures ; the laminae of unequal thickness, but 
 not horizontal. Thus it continues to the depth 
 often or twelve fathoms, when a more firm and 
 useful stone is procured, the largest pieces of 
 which are used for flat pavements. This is called 
 
 * Patrin Min. iii, 307. / 
 
120 DOMAIN I. S1DEROUS. 
 
 the top-stone, and continues for ten fathoms; 
 after which the quality improves with the in.- 
 creasing depth, till, at the twenty-fourth fathom 
 from the surface, the workmen arrive at the 
 most superior kind, called the bottom-stone. 
 The colour is grey blue; and the texture is so 
 close, that it will sound like a piece of metal. 
 The masses are separated from the rock by 
 wedges, driven by sledges of iron, and contain 
 from five to fourteen superficial square feet of 
 stone, r^j 
 
 " As soon as this mass is freed by one man, 
 another stone-cutter, with a strong wide chisel 
 and mallet, is ready to cleave it to its proper 
 thinness, which is usually about one eighth of 
 an inch : the pieces are generally from a foot 
 square to two feet long, by one wide ; but the 
 flakes are sometimes large enough for tables 
 and tomb-stones*." 
 
 STRUCTURE I. COMMON. 
 
 Aspect 1. Ash grey slate, from Angers, in 
 France. 
 
 Bluish grey slate, from Westmorland. 
 Purple or reddish purple slate, from Anglesea. 
 The same, with pyrites, &c. 
 
 * Brayley's Beauties of England, ii. 32g. 
 
MODE XII. . SLATE. 
 
 Aspect 2. Killas, from Cornwall, many va- 
 rieties ; blue, grey, or whitish yellow. If it con- 
 tain only 6 of iron, it belongs to the argillaceous 
 or to the magnesian schisti. 
 
 STRUCTURE II. MASSIVE. 
 
 The same identic substance of which slate is 
 composed has been discovered in France, and 
 other countries, in a massive form, or stratified 
 with the seams at great distances, and incapable 
 of being split into thin plates, like common slate. 
 It may probably be often discovered in the vicinity 
 of slate-quarries. 
 
 The slate with impressions so frequently found 
 with coal, and called shale, is commonly of an 
 earthy texture, and belongs to clay-slate. 
 
 Saussure mentions slate in columns like basalt*. 
 He also enumerates the following : 
 
 598. Granite, joined with slate; the last being 
 composed of mica and pierre de corne. 
 
 1862. A slate, with mica, in leaves thinner 
 than paper, sometimes straight, sometimes undu- 
 lated. It is, according to Saussure, a mixture of 
 ferruginous clay and mica. 
 
 * i. p. 523, 4to. 
 
DOMAIN I. SIDEROUS. 
 
 On the passage of Simplon an inter- 
 mediate slate, between the mica and the common, 
 of a brilliant and undulated appearance, contain* 
 ing garnets. 
 
 MODE XIII. MICA SLATE. 
 
 Arrangement. It is difficult properly to arrange mica slate. 
 Though it contain a great quantity of quartz, it 
 has always been classed among the argillaceous 
 substances, as the mica is the chief character- 
 istic. Mica sometimes contains no magnesia; 
 but according to the analyses given by Haiiy, 
 the brown, grey, or black, which are the most 
 abundant and common in mica slate, contain a 
 greater portion of iron than of argil, the quan- 
 tity of potash being also considerable. Bergman 
 found 9 parts of iron in mica; Kirwan nearly 
 20 : even of the colourless kind Klaproth dis- 
 covered 15 in one sort, and 22 in another. 
 
 Connexions. Mica slate has also a natural connexion with 
 common slate, into which it often passes*. It 
 must also be observed that Saussure found in the 
 
 * Daubuisson's curious and elaborate analysis (Jour, de Ph. 
 180Q) proves, that the composition of mica slate and slate is identi- 
 cally the same. The mode forms the only difference. 
 
MODE XIII. MICA SLATE. 123 
 
 Alps rocks in which scales of iron supplied the 
 place of mica. In all events the black mica 
 must belong to the siderous division; while the 
 white mica, which might be called micarel, and 
 sometimes passes into steatite, ought to be classed 
 among the magnesian substances*. 
 
 Mica slate has a further affinity with the si- 
 derous substances, as, like siderite, it frequently 
 contains garnets. It is very metalliferous, many 
 of the mines of Norway and Sweden, and a part 
 of those of Saxony and Hungary, being situated 
 in this rock. 
 
 STRUCTURE I. REGULAR. 
 
 Mica slate of a jet black, with black quartz, 
 from Switzerland. 
 
 Grey mica slate from Scotland, where it abounds 
 in the Grampian Mountains and some of the isles; 
 not to mention innumerable other regions. 
 
 Grey mica slate, used for ovens (Stellstein), 
 from Sweden. Wall. i. 427. 
 
 * Kirwan has called the brownish black mica micarclle, be* 
 cause it contains no magnesia ! Klaproth found in it : 
 0063 argil 
 2Q5 silex 
 675 iron 
 
 1033 
 
124 DOMAIN I. SIDEROUS. 
 
 In very thin plates, and of an almost impal- 
 pable grain, from Scotland. 
 
 Brown mica slate, from the same countries. 
 The green and white need not be here specified. 
 
 STRUCTURE II. IRREGULAR. 
 
 if 
 
 The noted hornberg of the Swedes belongs to 
 this division, being a coarse mica slate irregularly 
 contorted. It is very metalliferous *. As it is a 
 celebrated rock with a barbarous appellation, it 
 may be called Linnite, in honour of Linnaeus, a 
 native of Sweden, who however contributed but 
 little to its mineralogy. 
 
 Linnite, from Sweden. 
 
 The same, from Norway. 
 
 STRUCTURE III. MINGLED. 
 
 When mica slate is mingled with garnets, it 
 constitutes the Murkstein, orNorka, of the Swedes, 
 and the latter name might be retained, if requisite; 
 but garnets form so common an adjunct of mica 
 slate, that the distinction seems unnecessary. 
 
 Mica slate, with garnets, from innumerable 
 countries. 
 
 * See Journal des Mmes > No. 88, p. 257. It is granular, black- 
 ish, with thick and short layers. 
 
MODE XIII. MICA SLATE. 
 
 The same, with v schorl, from the Grampians. 
 
 The same, with sappare, the kyanite of Wer- 
 ner, from the mainland of Shetland, and from 
 Aberdeenshire *. 
 
 The same, with various ores. 
 
 Saussure mentions the following varieties : 
 
 A rock of reddish mica slate, of which the 
 
 r~ 
 
 leaves, being often curved, present at intervals 
 quartz in the form of lentiles, but often some 
 inches in length, and one or two in thickness. 
 1366. 
 
 A remarkable mica slate, composed of thin 
 white and grey leaves, so as to appear on the 
 sides like a striped stuff; the grey part being 
 mica, and the white a very fine arenaceous quartz. 
 1474. 
 
 A gneiss, composed of jad and siderite ; his jad 
 being probably compact felspar. 1331. 
 
 A part of the chain of Mont Blanc consists of a 
 hard ferruginous quartz, mixed with mica. 847. 
 
 * Sappare is the ancient Scotish name, retained by Saussure, who 
 informs us that he first received the substance from the duke of 
 Gordon. Werner's alteration is alike useless and absurd, the ori- 
 ginal appellation implying its similarity to sapphire, for which it, 
 has sometimes been substituted by jewellers. 
 
DOMAIN I. SIDEROUS. 
 
 MODE XIV. SIDEROMAGNESIAN ROCKS. 
 
 These rocks are far from being uncommon 
 /among primitive mountains, being chiefly com- 
 posed of magnesia and oxyd of iron. In the 
 Chlorite and substance called chlorite by Werner, from its 
 green colour, the iron often exceeds forty parts 
 in the hundred ; and it is even used as an ore of 
 that metal. Of actinote*, by some called acty- 
 nolite, some kinds contain as much iron as is 
 found in siderite ; and it is in general considered 
 as only a different structure of that rock. Saus- 
 sure indeed regarded chlorite as only a kind of 
 earthy siderite; but as it contains a far greater 
 portion of magnesia than siderite, in which that 
 substance is scarcely recognisable, it seems more 
 proper to allot to these rocks an article apart : 
 and the chemical mode of combination is at least 
 very different. 
 
 To this Mode may also be added another 
 Some mixture of iron and magnesia, those serpentines 
 
 serpentines. <- 
 
 which contain so great a portion of iron as to 
 affect the magnet. Most of the siderous rocks 
 consist of iron and clay. The eisenkesel, that is 
 
 * From the Greek anriVOT'o;, radiated, so that the y is foreign to 
 the orthography. 
 
MODE XIV. SIDEROMAGNESIAtf ROCKS. 127 
 
 the iron-flint, of Werner, is merely a vein-stone, 
 and never appears in the shape of a rock; and 
 generally the silex in siderous substances is lost 
 in the argil. The sidero-caltite and ferri-calcite 
 of Kir wan have little connexion with the present 
 subject, the former being pearl-spar, the latter 
 only embracing a few lime-stones, which contain 
 from 10 to 20 of iron ; but as they easily decom- 
 pose, present no remarkable variety, and are 
 little interesting, it is unnecessary to distinguish 
 them, except as mere diversities of lime-stone. 
 Innumerable marbles are tinged with iron, from 
 which they chiefly derive their colours ; but it 
 would be a too nice and useless distinction to 
 compose an arrangement from this mere acci- 
 dence, which varies in different parts of the 
 same rock. There remain therefore only the 
 magnesian rocks to be specially considered in 
 their conjunction with iron, a metal with which 
 they have often a singular affinity. 
 
 STRUCTURE I. CHLORITE. 
 
 This substance is by Werner divided into four 
 kinds ; chlorite earth, common or compact chlo- 
 rite, foliated chlorite, and chlorite slate. It seems 
 unknown to Wallerius, who published his last 
 edition in 1772 ; but is the green talc of Born, 
 
128 DOMAIN I. S1DEROUS. 
 
 and the Samnterd of old German writers, perhaps 
 from its velvety appearance. To the Cornish 
 miners, as it often occurs with tin, it is also known 
 by the name of peach*. 
 
 The first Aspect, that of chlorite earth, can 
 scarcely be said to form a rock, chiefly occurring 
 in clay-slate, and probably forming the green no- 
 dules in basaltin. The second kind is perhaps 
 unknown, save as a vein-stone ; and what is called 
 the foliated is generally crystallised, being found 
 at St. Gothard with other crystals. The only 
 rock therefore of the kind is : 
 
 Aspect 1. Chlorite slate. Texture, finely gra- 
 nulated, sometimes regularly, sometimes irregu- 
 larly ; schistose, so that fragments sometimes as- 
 sume the form of a wedge. 
 
 Hardness, gypsic. Fracture, sometimes even, 
 or undulating, or scaly. Fragments, slaty, blunt, 
 except when mixed with quartz. 
 
 Weight, sometimes granitose, sometimes car- 
 bonose. 
 
 Lustre, glistening, somewhat resinous. Opake. 
 
 Chlorite slate, from Egypt. Wad, 23, a small 
 statue. 
 
 Chlorite slate, from Corsica, Norway, Sweden, 
 
 - 
 
 * It is the laldogea of Saussure, so called from Monte Baldo. 
 
 * 
 
MODE XIV. S1DEROMAGNESIAN ROCKS. ] 25) 
 
 Stiria, Tyrol, Scotland, &c. It is generally sprin- 
 kled with octaedral crystals of iron, and some- 
 times with garnets. The first are the most cha- 
 racteristic of this rock. 
 
 Chlorite slate, mixed with quartz. This kind 
 is commonly even schistose, but far more hard 
 than the former. 
 
 Saussure, 2264, expresses great surprise, 
 when, on receiving specimens of the chlorite slate 
 of Werner, he observed that there was scarcely 
 any chlorite in them ; and he adds, that the de- 
 nomination being quite deceitful, it ought to be 
 changed. 
 
 On the lofty summit called the Col du Geant, 
 Saussure found that the granite, like that which 
 is greatly elevated at Mont Blanc, can scarcely be 
 said to contain mica. Here its place was often 
 supplied by a small-grained chlorite*. 
 
 STRUCTURE II. ACTINOTE. 
 
 This substance also chiefly occurs in small por- 
 tions. It is the strahlstein of the Germans, and is 
 by Werner divided into the asbestoid, the com- 
 mon, and the glassy. Of these it is believed the Glass y 
 
 actmote. 
 
 * Sauss. 204. 
 VOL. I. K 
 
130 DOMAIN I. SIDEROUS. 
 
 last only appears in the form of rocks. Saussure, 
 who calls it delphinite, or green schorl of Dau- 
 phiny, describes a rock of this kind. He also 
 mentions smaller portions of a compact kind. 
 
 That the glassy actinote strictly belongs to the 
 siderous domain, will appear by the analysis of 
 Vauquelin; silex 37, argil 21, lime 15, oxyd of 
 iron 24, with a small portion of manganese*. 
 
 Texture, sometimes massive, but generally in 
 thin six-sided acicular crystals. 
 
 Hardness, between marmoric and basaltic. 
 Fracture, fibrous and radiated. Fragments, splin- 
 tery and very sharp. 
 
 Weight, siderose. 
 
 Lustre, shining and glassy; strongly translu- 
 cent. 
 
 Actinote, from Switzerland, where, as has been 
 mentioned, it forms entire rocks. 
 
 STRUCTURE III. SIDEROUS SERPENTINE. 
 
 Of this kind Humboldt discovered a curious 
 rock with magnetic power, forming the mountain 
 of Regelberg, in Germany; the south side attract- 
 
 * Lametherie observes, that the earthy smell shows an approxi- 
 mation to hornblende. Th. de la Terre, ii. 373. Is not schorl a 
 black actinote? 
 
 
MODE XIV. SfDEROMAGNESIAN ROCKS. J31 
 
 ing the north pole, and the northern side the south 
 pole. 
 
 Rocks of the same kind may probably be dis- 
 covered in other countries; at any rate many ser- 
 pentines are so replete with iron as to fall into 
 this division. 
 
 Saussure, 1342, gives a minute description of 
 what he calls granular serpentine. It is so much 
 impregnated with iron, that it belongs to the si- 
 deromagnesian rocks. 
 
 The mountain called Roth Horn is in a great 
 part composed of compact serpentine, semi-hard, 
 that is, of the hardness of marble. It is called 
 the Red Horn, because the serpentine, though 
 green within, is red on the surface, from the oxyd- 
 ation of the iron*. 
 
 * Sauss. 215?. 
 
I>OMA1N 1. SIDEHOUS. 
 
 MODE XV. SIDEROUS INTRITE. 
 
 intrites. The rocks here called INTRITES, because crys- 
 tals or particles are imbedded in a paste, are 
 distinguished from Glutenites, in which the par- 
 ticles coalesce together with little or no visible 
 cement. The former have by the Germans 
 been styled porphyries, from a similarity of 
 structure ; but the interspersiori of a few crys- 
 tals, especially of felspar or felsite, substances as 
 common as mica, can hardly even be said to 
 alter the nature of the rock ; and such sub- 
 stances ought in geology to be classed with 
 their parent base; for while all these kinds of 
 pretended porphyries are classed under one head 
 by Werner and his disciples, great confusion 
 arises from their totally different natures. 
 
 In the present work the intrites and glutenites 
 are classed under the several domains to which 
 they belong ; but as the bases are of different 
 kinds, it has been thought advisable to bring 
 them under one point of view, at the end of 
 each domain. As however the chief siderous 
 intrites are the genuine porphyries, the pre- 
 servation of that classical and universal name 
 will considerably restrict the present division. 
 
MODE XV. SIDEROUS INTRITE. 133 
 
 STRUCTURE I. VARIOLITES. 
 
 When the crystals, instead of being of an oblong 
 cubic form, as in porphyries, assume an oval, but 
 particularly a round shape, the rock may be aptly 
 styled a variolite, every denomination being use- 
 ful which saves circumlocution. 
 
 The stones called variolites of Durance, being Variolites of 
 
 Durance. 
 
 pebbles rolled down by that river in Dauphiny, 
 belong to this article*. The prominence of the 
 round crystals of felspar, having a faint resem- 
 blance to the pustules of the small-pox, has oc- 
 casioned this appellation. Patrin f has minutely 
 described the variolites of Durance, as being in his 
 eye the same with the ancient green porphyry, 
 being a corneenne, or basaltin, fusible into a black 
 amel attractable by the magnet. The spots, of a 
 finer green, or sometimes white, are often sur- 
 rounded with two zones of these colours. Saus- 
 sure, whose description is very minute, 1539, 
 regards the globules as composed of that kind of 
 felspar which, being of a greasy appearance, like 
 one of the kinds of quartz, is called unctuous fel- 
 
 * Faujas says that he found, near the village of Servieres, the 
 rocks which afford the variolites of Durance. For those of the 
 Drac, see Amygdalite. 
 
 t i. 147. 
 
DOMAIN I. SIDEROU8. 
 
 spar, or rather felsite ; for Werner has pronounced 
 that the felspar in the ancient porphyries is com- 
 pact. 
 
 The variolites of Turin are of a brownish grey, 
 qf a shining and unctuous appearance, with spots 
 of a lighter grey, and white starry crystals. The 
 variolite of Sesia is of a reddish grey, with spots 
 of a bright brick red. 
 
 Saussure mentions, 1289, a kind of soft vari- 
 olite, seemingly composed of green siderite, with 
 spots of white felspar, sometimes rhomboidal, 
 sometimes circular. 
 
 STRUCTURE II. IRON-STONE WITH IMBEDDED 
 CRYSTALS. 
 
 Iron-stone, with crystals of quartz, from the 
 Surry hills. 
 
 Saussure mentions, 1322, a red and green 
 porphyry, or rather intrite, mixed with felspar 
 and actinote; the base being of granular felspar. 
 
DOMAIN I. SIDEBOUS. 135 
 
 MODE XVI. SIDEROUS GLUTENITE. 
 
 In arranging these substances, two objects 
 are to be considered ; the nature of the frag- 
 ments or particles cemented, and that of the 
 cement itself. When they are both of one kind, 
 as a siliceous bricia*, or a pudding-stone with a 
 siliceous cement, there can arise no doubt con- 
 cerning their classification : but when, as often 
 happens, the fragments are of one kind, and the 
 cement of another, the domain may appear 
 doubtful. The more general method however 
 appears to have been, to denominate the sub- 
 stances from the cement, as being the pre- 
 dominating agent ; and this rule is particularly 
 applicable in the present instance, as oxyd of 
 iron forms the strongest of natural cements. 
 Bricias of basaltin or jasper are commonly ce- 
 mented by the same substance, and sometimes, 
 though rarely, by quartz ; but they may still be 
 referred to the predominating substance, the 
 
 * This word is strictly Italian ; Iricia, a crumb or small frag- 
 ment, with its derivatives Iricioletta, a little crumb, Iriciolmo, and 
 Iriciolo. Breccia b only a corruption. 
 
 The Italian architects and statuaries gave the first modem classical 
 names to rocks, as granite, granitone, granitino, &c. &c. 
 
I>OMAIN 1. S1DEROUS. 
 
 quartz being common, and of inferior consi- 
 deration. 
 
 The division of glutenites into bricias and 
 
 pudding- 
 
 stones. pudding-stones, the former consisting of angular 
 fragments, the latter of round or oval pebbles, 
 would not be unadvisable, were it in strict con- 
 formity with nature. But there are many rocks 
 of this kind ; as, for example, the celebrated 
 Egyptian bricia, in which the fragments are 
 partly round arid partly angular*; while the 
 term glutenite is liable to no such objections, 
 and the several structures identify the various 
 substances. 
 
 English The celebrated English pudding-stone, found 
 
 pudding-stone. 
 
 no where in the world but in Hertfordshire, ap- 
 pears to me to be rather an original rock, formed 
 in the manner of amygdalites, because the peb- 
 bles do not seem to have been rolled by water, 
 which would have worn off the substances in 
 various directions ; while, on the contrary, the 
 white, black, brown, or red circlets, are always 
 entire, and parallel with the surface, like those 
 of agates. Pebbles therefore, instead of being 
 united to form such rocks, may, in many cir- 
 cumstances, proceed from their decomposition ; 
 
 * So also the celebrated pudding-stone of England. See Ano- 
 malous Rocks. 
 
MODE XVI. SIDEEOUS GLUTENITE. 137 
 
 the circumjacent sand also arising from the de- 
 composition of the cement. 
 
 Mountains or regions of real glutenite often, 
 however, accompany the skirts of extensive 
 chains of mountains, as on the north-west and 
 south-east sides of the Grampian mountains in 
 Scotland, in which instance the cement is affirm- 
 ed by many travellers to be ferruginous, or some- 
 times argillaceous. The largeness or minuteness 
 of the pebbles or particles cannot be said to alter 
 the nature of the substance ; so that a fine sand- 
 stone is also a glutenite, if viewed by the mi- 
 croscope. They may be divided into two struc- 
 tures : the large-grained, comprising bricias and 
 pudding-stones ; and the small-grained, or sand- 
 stones. 
 
 STRUCTURE I. LARGE-GRAINED GLUTENITES. 
 
 Siderous glutenite, or pudding-stone, from Dun- 
 stafnage, in Scotland, where it forms romantic 
 rocks of a singularly abrupt appearance, in some 
 parts resembling walls. The kernels consist of 
 white quartz, with green or black trap, porphyries, 
 and basaltins. 
 
 Glutenite, from the south of the Grampians, 
 from Ayrshire, from Inglestone bridge, on the 
 road between Edinburgh and Lanark. But of 
 
138 DOMAIN I. S1DEROUS. 
 
 these the cement is often siliceous, as in those at 
 the foot of the Alps, observed by Saussure. The 
 siderous glutenites commonly originate from the 
 decomposition of siderous rocks, which also afford- 
 ed the cement. 
 
 Glutenite, consisting of fragments of granite, 
 cemented by trap. 
 
 Siderous glutenite, or pudding-stone of the most 
 modern formation. This is formed around can- 
 nons, pistols, and other instruments of iron, by 
 the sand of the sea. 
 
 Glutenite of small quartz pebbles, in a red fer- 
 ruginous cement, found in the coal-mines near 
 Bristol, &c. 
 
 Basaltic bricia, from Arthur's Seat, near Edin- 
 burgh. 
 
 Porphyritic bricia (Linn, a Gmelin, 247), from 
 Dalecarlia in Sweden, and Saxony. Calton-hill, 
 Edinburgh ? 
 
 STRUCTURE II. SMALL-GRAINED. 
 
 Aspect 1. The most remarkable of the side- 
 rous sand-stones, is that cekbrated by the German 
 geologists under the appellation, given by the 
 Rothetodt miners, of Rothe todt liegendes, or the red and 
 
 hegendes. 
 
 dead layer ', so called from its colour, and because 
 it is wholly unproductive, no minerals being found 
 
MODE XVI. SIDEROUS OLUTENITE. 139 
 
 in or under it. This singular rock has been termed 
 semiprototite by Mr. Kirwan, implying that it is 
 half primitive ; and he informs us that it is com- 
 monly found under coal, is micaceous, and con- 
 tains lumps of porphyry or granite. The grains 
 are generally quartz or keralite, the cement being 
 an irony clay, which imparts the colour. 
 
 But as the passage affords some curious Ger- 
 man learning on the subject, from books little 
 known in this country, it shall be presented entire. 
 
 " Semiprotolites (Rot he todt liegendesj. 
 
 " These stones I call by this name, as being 
 partly of primeval, and partly of subsequent, ori- 
 gin : they consist of pebbles, or of fragments, or 
 of sand of primeval origin, compacted and ce- 
 mented by an argillaceous, or calcareous, or sili- 
 ceous cement, of posterior origin; hence they 
 generally form the lowest stratum that separates 
 primeval rocks and secondary strata. From their 
 composition, they come under the denomination 
 either of farcilites, brecias, or sand-stones. Iii 
 some places this sand has been accumulated into 
 vast heaps, so as to form mountains 6 or 700 feet 
 high, and then compacted by an adventitious ce- 
 ment. Of this sort are the mountains of Hertz- 
 berg and Kaulberg, near Ilefeld, in which the 
 sand is cemented by a ferruginous cement, and 
 
]40 DOMAIN I, SIDEROUS. 
 
 contains fragments of porphyry, and also veins of 
 iron-stone, and manganese, and strata of coal, with 
 impressions of reeds, rushes, and other 'plants, 
 Lasius, 249 and 280. The red colour is evidently 
 from iron. 
 
 " The semiprotolite of Wartburg, near Eisenach, 
 contains rounded lumps of granite and schistose 
 mica : substances found in the neighbouring moun- 
 tains. The semiprotolite of Goldlauter consists 
 entirely of porphyry, as do the primeval moun- 
 tains of that district. That of Kiffhauserberg, in 
 Thuringia, contains rounded argillites from the 
 neighbouring mountains of the Hartz. Petrified 
 wood is found in this last, Voigt's Letters, 19, 
 20. According to Voigt, the semiprotolite found 
 under coal has a siliceous cement, and contains 
 few primitive stones; Lettres sur les Montagnes, 
 3 1 . Saussure made the same observation on those 
 which he found on the descent of Trient, which 
 interceded between the primary and secondary 
 mountains, 2 Sauss. 699- He even remarked 
 long before, that primeval and secondary rocks 
 were almost always separated by a sand-stone or 
 farcilite, 1 Sauss. 594. Where the secondary 
 strata are calcareous, the semiprotolite has a cal- 
 careous cement; see Lehm. 168. Semiprotolite 
 is always red, by reason of the ferruginous par- 
 ticles by which it is cemented; its diffusion or 
 
MODE XVI. SIDEROUS GLUTENITE. 141 
 
 expansion is unequal, being frequently horizontal 
 or even, but sometimes depressed, and in other 
 instances much elevated. Most of the super- 
 imposed strata partake of this inequality, and are 
 its natural consequences. Hence the protuber- 
 ances and depressions, otherwise called moulds, 
 observed in them ; Charp. Saxony, 371. It rests 
 on granite, Ibid. 370, 371."* 
 
 Mr. Jameson informs us that in the Hartz it 
 rests on grauwack, and extends nearly round the 
 whole of the country; nay, through Saxony, Hessia, 
 Bohemia, Silesia, and Franconia. The red sand- 
 stone of the north of England, which is micaceous, 
 and often regularly schistose, so as to form pave- 
 ments, &c. seems also to belong to this formation. 
 As the substance is widely spread and highly re- 
 markable, the barbarous denomination may be 
 exchanged for that of Lasite, in honour of Lasius, 
 the celebrated describer of the Hartz, who has 
 ably illustrated this substance. 
 
 Lasite, of various kinds, from Germany, of 
 which there is a series at the College des Mines, 
 in Paris, where it was shown to me by Daubuisson. 
 
 The same, from the north of England, &c. &c. 
 
 * Kirwan Geol. Essays, 25 6. 
 
14Q DOMAIN I. SIDEROUS. 
 
 Aspect 2. Ferruginous sand-stone, of a light 
 brown, with glandules and veins of a deeper 
 colour, from Mont Calvaire, near Paris, where it 
 is frequent in ferruginous sand, probably arising 
 from its decomposition. 
 
 A ferruginous sand-stone, mentioned by Mr. 
 Kirwan, afforded 19 parts of iron in the 100. 
 The Eisensanderz, or iron sand-stone of the Ger- 
 mans, is of this kind, and is sometimes worked as 
 an ore of iron. 
 
 In the Vosges mountains the summits are often 
 of ferruginous sand-stone, resting on granite*. 
 Dietrich, as already mentioned, thinks that red 
 sand-stone is as primitive as granite itself. 
 
 * Dietrich, Sivry, &c. Saussure says, 699, that the deadlyer 
 of the Germans, or rather deadlayer, is a pudding-stone. 
 
DOMAIN II. 
 
 SILICEOUS. 
 
 SILEX, SILICA, OR SILICEOUS EARTH. 
 
 THIS earth derives its name from the 
 silex, or flint, in which it abounds. Some 
 also denominate it quartzose earth, be- 
 cause it is perhaps more abundant in the 
 stone called quartz, which, when trans- 
 parent and crystallised, is styled rock crys- 
 tal. It so frequently occurs in the form 
 
144 
 
 DOMAIN II. SILICEOUS. 
 
 of sand, which covers a great part of the 
 globe, either alone or mixed with clay, that 
 late chemists infer that such sand arises not 
 only from the decomposition of rocks, but 
 is often a disturbed or hasty crystallisation 
 of silica*. This is further confirmed by the 
 circumstance that many primitive moun- 
 tains consist of granular quartz, of an arena- 
 ceous appearance, like agglutinated sand. 
 
 The stones now called siliceous, were 
 formerly denominated verifiable; because, 
 with an alkali, they may be melted into 
 glass; and the finest Venetian glass was 
 fabricated from quartz, by the Italians 
 called tarso-f. Silica, like the other sim- 
 ple earths, is a fine white powder; but the 
 particles have a harsh feel, like minute 
 sand. Alone it is scarcely fusible; but 
 when newly precipitated, is soluble in 1000 
 parts of water. 
 
 * The purity of this term may be doubted. Alumina is ridicu- 
 lous, being the plural of alumen. In the fabrication of new words 
 grammatical precision ought always to be studied. 
 
 f In the Phil. Trans. 1683, Dr. Lister says tar so is the quartzose 
 sand of which the fine Venetian glass was made. The same inge- 
 nious author there proposes, p. 739, Mineral Maps of Counties, as 
 he calls them. 
 
DOMAIN II. SILICEOUS. 145 
 
 Joined with iron, argil, and magnesia, it 
 constitutes the primitive and most import- 
 ant rocks, rising to the regions of perpetual 
 snow, and thus supplying unfailing aliment 
 to the great rivers that fertilise the earth. 
 When considered in these mountains, in 
 sand, and in clay, it may be pronounced 
 the most abundant of all the earths : and 
 if iron form the nucleus, the shell of this 
 planet may be said to consist chiefly of 
 silex. It is suspected that it is coeval 
 and intimately connected with iron ; as the 
 aerolites or meteoric stones, and the large 
 masses of native iron, discovered in Siberia 
 and South America, contain abundance of 
 silex mixed with some magnesia*. 
 
 Siliceous substances generally strike fire 
 with steel ; and flint or quartz yields a pe- 
 culiar odour, supposed by some to arise 
 from a subtile substance which chemistry 
 has not been able to discover. A strong- 
 phosphorescence is also produced by col- 
 
 * Chrysolite, a mixture of silex and magnesia, is always found in 
 native iron. The exclamation of Henkel is well known : 
 
 O silex! silex! quae te raatercula gessit? 
 VOL. I. L 
 
DOMAIN II. SILICEOUS. 
 
 lision, so that, during Alpine hurricanes, 
 the torrents, rolling large fragments of rock, 
 present a singular scene of confiscation. 
 
 MODE I. QUARTZ. 
 
 Distinctive Texture, compact, generally uniform, some- 
 times granular, rarely laminar, in which form 
 the lustre is generally dull. 
 
 Hardness, crystallic. Fracture, splintery, but 
 such as sometimes to resemble the conchoidal. 
 Fragments, very sharp. 
 
 Weight, granitose. 
 
 Lustre, glistening or shining, sometimes unc- 
 tuous. From transparent to opake. 
 
 Colour, generally white; sometimes brown, 
 grey, yellow, red, or black. 
 
 It sometimes composes entire mountains, and 
 abounds in those of granite, in which substance 
 it is seldom crystallised. 
 
 STRUCTURE I. COMPACT. 
 
 Aspect 1. Opake. A very common substance, 
 
 but the specimens of entire mountains are rare. 
 
 sites. Xhe mountain of Kultuck, on the south-west 
 
 end of the lake Baikal, 350 feet high, and 4800 
 
 long, and still broader, consists entirely of milk- 
 
MODE I. AUARTZ. 147 
 
 white quartz: per Laxman, 1 Chy. An. 1785, 
 265. Also Flinzberg, in Lusatia, almost entirely. 
 2 Berg. Jour. 1789, 1054. There is also an ex- 
 tensive narrow ridge of quartz, some miles long, 
 in Bavaria. 2 Berg. Jour. 1790, 529, &c. Hurl 
 Bavaria, 309. Monnet mentions a rock of quartz 
 60 feet high. 17 Roz. 163. Mountains of it also 
 occur in Thuringia. Voigt Prack. 69. and in Si- 
 lesia. Gerh. Beytr. 87. and in Saxony. 1 Berg. 
 Jour. 1788, 269. and in layers between gneiss 
 and slate mica. 2 Lenz. Also in Scotland. 2 
 Wms. 52. It is not metalliferous. Werner Kurse 
 Classif. 15. Petrol is often found in it. 1 Berg. 
 Jour. 1 79 1 , 91. The mountain of S wetlaia Gora, 
 among the Uralian, consists of round grains of 
 quartz, white and transparent, and of the size of 
 apea^ united without any cement. 2 Herm. 278*." 
 Mountains of quartz also occur in Scotland, 
 where, from the white substance, they sometimes 
 appear as if covered with snow. A hill of this 
 kind is seen near Cullen, which supplies glass- 
 works at Newcastle with quartz. The mountains 
 of Scuraben and Morven, in Caithness, are chiefly 
 constituted of this substance ; which also, accord- 
 ing to Mr. Jameson, occurs in great quantity in 
 the islands of Hay, Jura, and Coll. There are 
 also large rocks of quartz in Upper Lorn. Buf- 
 
 * Kirvvan Geol. Ess. 179. 
 
148 DOMAIN II. SILICEOUS. 
 
 fon says*, there is in ^uvergne, near Sal vert, a 
 vein of quartz 10,000 fathoms in length. 
 
 In the Uralian mountains it sometimes happens 
 that there is an entire mountain of quartz, another 
 of felspar, and a third of talc, thus presenting the 
 materials of granite on a very large scale. 
 
 Aspect 2. Semi-transparent. This sometimes 
 forms very extensive veins, but perhaps never con- 
 stitutes an entire hill or rock. 
 
 Aspect 3. Unctuous. This also appears in 
 veins, and generally accompanies metals. 
 
 STRUCTURE II. GRANULAR. 
 
 This kind often constitutes entire mountains in 
 Scotland, and other parts of the world. It has 
 sometimes been confounded with siliceous sand- 
 stone, but late writers have demonstrated that it 
 may be owing to a primitive but disturbed crystal- 
 lisation f. Nor is it inconsistent that where the 
 cement was deficient or interrupted, it should 
 appear among the most ancient substances in the 
 shape of mere sand. The grains, as already men- 
 tioned, are sometimes of the size of peas. 
 
 * Min. i. 100. 
 
 t Collate however the account of the Siliceous Sand-stones, 
 Mode XIV. Str. 2. 
 
MODE I. QUARTZ. 149 
 
 Grey granular quartz, from Balahulish, in Scot- 
 land. 
 
 The same, with veins of white semi-transparent 
 quartz, from Bunessan, Mull. 
 
 Saussure describes, 999, rocks of a beautiful 
 granular quartz, which rises in leaves of a rhom- 
 boidal form. It is very hard, and has the grain 
 and whiteness of statuary marble. 
 
 He also observes, 2235, that in primitive lime- 
 stone there are often veins of quartz, as there are 
 also veins of keralite or hornstein in compact lime- 
 stone. Query, if both the latter substances do 
 not contain more argil ? 
 
 Mr. Playfair observes that granular quartz is 
 common in Scotland, alternating with schisti, par- 
 ticularly on the north side of the harbour of Bala- 
 hulish, and on the sea-shore at Cullen. He also 
 shows that sand is a crystallisation ; and mentions 
 a siliceous grit with no cement*. 
 
 ,In Buckinghamshire, Wiltshire, and Dorset- 
 shire, where there are only sand and chalk, there 
 is found in the sand a prodigious number of large 
 blocks of granular quartz, which is used for paving 
 or building. The castle of Windsor, and the ter- 
 race, are built of this stone, probably from the 
 forest, or the neighbouring heaths, where there is 
 
 * Hutt. Theory, 27, 171, &c, 
 
150 DOMAIN II. SILICEOUS. 
 
 a great quantity; and Stonehenge is built of these 
 blocks. So blocks of granite are found in Bran- 
 denburg, Mecklenburg, and Pomerania*. 
 
 Mountains of granular quartz abound in Scot- 
 land ; and granitic mountains in Sweden. When 
 the continents were gradually emerging, and before 
 these large subsidences which form mediterranean 
 seas, it may easily be conceived that the plains 
 where such blocks, and gravel foreign to the sur- 
 rounding mountains, are always found, were co- 
 vered for ages by the waters of the ocean, which 
 rolled these blocks and gravel in the direction of 
 their currents. 
 
 In a late volume of the Philosophical Trans- 
 actions f, Bournon gives some observations on the 
 different modes of attraction, which influence the 
 formation of minerals. The attractions of aggre- 
 gation are either simple or crystalline. 
 
 " It sometimes happens (owing perhaps to a 
 more considerable degree of disturbance during 
 the process of attraction), that there are found 
 small irregular detached masses, often so minute 
 as to be scarcely perceptible ; at other times they 
 are of a larger size, and, as soon as formed, fall to 
 the bottom of the liquor, and unite together by a 
 
 * De Luc, Geologic. Paris 1809, 8vo. p. 332. 
 f 1804, p. 37. 
 
MODE I. QUAfcTZ. 
 
 simple mode of attraction, which may with great 
 propriety be called simple homogeneous attraction 
 of aggregation. Of this kind are, granulated 
 quartz, granulated carbonate of lime, &c. the dif- 
 ferent kinds of which substances differ from each 
 other only by the fineness or coarseness of their 
 grain." 
 
 Sometimes this takes place along with the crys- 
 talline, whence small crystals, &c. Sometimes 
 the molecules are precipitated in a detached but 
 confused manner, so as to form earthy or compact 
 substances. In aggregate stones there is the 
 attraction of aggregation, as in granite, sand- 
 stone, and others. 
 
 But long before, Mr. Kirwan* had made the 
 following observations : 
 
 " The first step in the process of crystallisation 
 is the formation of grains ; the second is the in- 
 crease in one dimension ; the third in two dimen- 
 sions ; and the fourth in three dimensions : the 
 grains themselves, however, to be visible, must 
 receive accretions in the three dimensions. If the 
 process be uninterrupted, no traces of distinction 
 will be perceived, and the whole will appear per- 
 fectly uniform ; but, if it be disturbed in the first 
 step, no crystallisation can take place ; if in the 
 
 Min. i. 21, edit. 
 
152 
 
 DOMAIN II. SILICEOUS. 
 
 second, the grains will appear distinct, small or 
 gross, coarse or fine, according to the nature of 
 the disturbance, whether by the interruption of the 
 process, or the accession of foreign matter ; this 
 latter generally produces coarse or rude grains, in 
 proportion to the quantity. 
 
 " If the disturbance only takes place in the 
 third stage, we shall have fibres or strias, as com- 
 plete surfaces cannot be formed ; the striae having 
 more extension in breadth than the fibres or fila- 
 ments, argue a smaller degree of disturbance than 
 the mere fibrous appearance. 
 
 " If, during the third stage, the strias be forced 
 into contact by the gradual dereliction of the fluid 
 that kept them suspended, they will form lamellas 
 in proportion as they are deserted, which will 
 either adhere to each other, and then fall con- 
 fusedly, being too heavy to be supported by the 
 menstruum, or, if supported, will be superimposed 
 on each other. 
 
 " But if the process of crystallisation be dis- 
 turbed only in the fourth stage, then the form and 
 shape only of the crystals will be more or less 
 altered. 
 
 " All these steps are noticed and described by 
 chemical writers; and particularly by the cele- 
 brated Rouelle, in the Memoirs of the Academy of 
 Paris on the crystallisation of salts." 
 
MODE II. KERALITE. 153 
 
 STRUCTURE III. LAMINAR. 
 
 This is generally dull, and approaches to the 
 next Mode, keralite, or rock-flint. The layers are 
 commonly thin, that is, from a quarter of an inch 
 to an inch. It forms a hill near Bamf. Saussure, 
 1483, has described a black schistose quartz, 
 which may be a siliceous schistus of the Ger- 
 mans. 
 
 The cellular, stalactitic, fibrous, and other struc- 
 tures, seem to occur only in small portions, and 
 rather belong to lithology or gemmology. 
 
 MODE II. KERALITE, OR ROCK-FLINT. 
 
 Texture, compact and uniform, but sometimes characters, 
 laminar. 
 
 Hardness, crystallic. Fracture, splintery, con- 
 choidal : the scaly fracture distinguishes it from 
 flint. Fragments, sharp. 
 
 Weight, granitose; sometimes, but rarely, car- 
 bonose. 
 
 Lustre, dull. Opake; but often translucent 
 on the edges. 
 
 Colour, grey, black, green, &c. 
 
 It composes entire mountains. 
 
 This rock is the hornstdn of the Germans, 
 
154 DOMAIN 11. SILICEOUS. 
 
 Petrosiiex. anc | thepetrosilev of their writers in Latin - 9 which 
 has of course been confounded with the petro- 
 silex of the Swedes and French, which is com- 
 pact felspar. To avoid this confusion the Greek 
 term keralite has been adopted, from Lametherie. 
 Keralite is not fusible by the blow-pipe, but 
 compact felspar generally is. It is also often 
 found impregnated with metals, while compact 
 felspar or felsite has perhaps never been observed 
 to attend metals. Felsite also presents the va- 
 rious colours of felspar; while keralite chiefly 
 passes from white, through grey, to black. It 
 may be regarded as an impure quartz, and 
 shares the sites and properties of that substance. 
 In England it is called chert, and often runs 
 in veins or layers through lime-stone, particu- 
 larly in Derbyshire. 
 
 STRUCTURE I. MASSIVE. 
 
 Aspect 1. Common. Bluish grey rock-flint, 
 sometimes mamellated, and approaching to chal- 
 cedony, from the lead-mines of Bretagne. This 
 is properly a vein-stone ; and Brongniart has ob- 
 served, i. 355, that such are hornsteim, though the 
 appearance be waxy, as they are infusible. Fel- 
 spar or felsite rarely appear as vein-stones. 
 
 Of a lighter grey, with blende and galena, from 
 the same. 
 
MODE II. KERALITE. 1J5 
 
 With different laminar shades of black, but not 
 with a laminar fracture, from Giromagny in the 
 Vosges mountains, France*. 
 
 Interspersed with native silver, from the famous 
 mountain of Schlangenberg, or Zmeof, in the south 
 of Siberia, which seems entirely to consist of rock- 
 flint, mixed with silver. 
 
 From the great oriental chain of mountains in 
 Siberia, where, according to Patrin, it underlays 
 the ribbon jasper. 
 
 With crystals of felspar it forms what Werner 
 styles horns tone porphyry, for which see the Si- 
 liceous Intrites. 
 
 Aspect 2. Unctuous. There is also an unc- 
 tuous keralite, like what is called fat quartz. It 
 is sometimes mistaken for felsite. 
 
 STRUCTURE II, LAMINAR. 
 
 Aspect 1. The siliceous schist us of Werner, a 
 term very vague, as there are so many schisti of a 
 siliceous nature, is by Mr. Kirwan and others re- 
 garded as a schistose hornstone. It is a primitive 
 rock, usually of a greyish black, intersected with 
 
 * In another work the author has said that, in the ancient 
 phraseology, forests and mountains were often confounded. Roeslin 
 de Sylva Pdsgovia (that is, an account of the mountains of Wasgaw, 
 or Vosges) is a modern example- 
 
156 DOMAIN II. SILICEOUS. 
 
 small veins of white quartz. Of this the basanite, 
 or Lydian stone of Werner, is accounted only a 
 diversity ; but many regard it as a black jasper, 
 and as all the jaspers are impregnated with iron, 
 it w r ould be truly surprising if there were no black 
 jasper. According to Mr. Jameson, the flinty 
 slate of Werner not only occurs in considerable 
 beds in primitive slate, but also, like quartz, forms 
 entire mountains. 
 
 It appears by the French writers to have been 
 sometimes confounded with a fine trap or basalt. 
 Latterly siliceous schistus has been understood to 
 present various colours; and when it occurs in 
 grauwacke slate, is regarded as a transitive rock. 
 The primitive is said to underlay the granite of 
 Mount Sorel, in Leicestershire. 
 
 chert. Aspect 2. The chert of the English* chiefly 
 
 occurs in layers in lime-stone, and sometimes con- 
 stitutes a mass of petrified shells. 
 
 Dark grey chert, with lime-stone, in layers, 
 from Derbyshire. 
 
 Reddish chert, with lime-stone, from France. 
 
 Brown chert, full of petrified shells, from Der- 
 byshire. 
 
 In bowls, with concentric layers, brown and 
 grey, from Vaucluse. Saussure, 1546. 
 
 * Chertz of some counties, which seems related to quartz. 
 
DOMAIN II. SILICEOUS, 157 
 
 MODE III. FELSPAR. 
 
 Texture, strait, foliated. Characters. 
 
 Hardness, of course felsparic. Fracture, la- 
 minar. Cross fracture, fine-grained, uneven, 
 approaching the splintery. Fragments, sharp, 
 rather rhomboidal. 
 
 Weight, granitose. 
 
 External lustre, shining ; of the cross fracture, 
 glimmering, glassy, sometimes pearly. Trans- 
 lucent. 
 
 Colour, many varieties of white, grey, green, 
 and red ; rarely blue or black. 
 
 It often composes mountains, especially when 
 interspersed with mica; and is the most abundant 
 substance in granite, where it often forms distinct 
 crystals *. 
 
 There are mountains and large strata of fel- 
 spar in the north of Scotland. 
 
 * It is sometimes classed with the Argillaceous, because some 
 kinds decompose into clay ; yet this effect probably arises from the 
 potash. But it forms the chief part of granite, which has never 
 been classed among argillaceous substances. 
 
 According to Lametherie, v. Q, felspar requires the most water 
 to crystallise, so must be the most ancient ; and is followed by horn- 
 blende, quartz, mica, magnesia, and the metals successively. But 
 the grey petrosilex of Vosges is a felsite. Ib. 352. 
 
158 DOMAIN II. SILICEOUS. 
 
 STRUCTURE I. COMMON. 
 
 Aspect 1. Common foliated. This rarely forms 
 entire mountains, but such have been discovered 
 in Siberia. When it forms mountains it is gene- 
 rally white. 
 
 Aspect 2. Granular. Ptocks of a fine white 
 granular felspar, resembling statuary marble or 
 dolomite. Sauss. 2144. 
 
 Aspect 3. Unctuous. Saussure, 1304, de- 
 scribes what he calls felthspath gras, or unctuous 
 felspar, as having a visage more oily and trans- 
 lucent than common felspar : the fracture rarely 
 laminar; and the plates, when perceivable, not 
 being level, but often convex, so that almost all 
 the fractures are generally conchoidal. It is harder, 
 and less fusible, than the common. 
 
 STRUCTURE II. MINGLED. 
 
 This division may justly comprise numerous 
 rocks and entire mountains, consisting of felspar 
 interspersed with a little mica or quartz, or a few 
 garnets ; the preponderance of the felspar being so 
 great that they cannot be considered as granitels. 
 
MODE III. FELSPAR, 
 
 159 
 
 Such rocks may be said to be always white, like 
 those consisting of felspar alone. 
 
 Felspar rock, with a few garnets, from a moun- 
 tain in the west of Scotland. 
 
 The same, lightly sprinkled with mica, from the 
 Alps. 
 
 The same, with a few grains of quartz, Petuntzc 
 of the Chinese, from Limoges, in France. The 
 fine porcelain of Sevre is composed of this sub- 
 stance, the quartz being carefully separated. The 
 same is also found in Cornwall, Saxony, China, 
 and many other countries. When the felspar is 
 decomposed into a white clay, it is called kaolin, 
 and is also necessary in the fabrication of porcelain. 
 
 The beautiful opalised kind of felspar, called 
 Labrador stone, is also a component part of rocks 
 in Finland and Norway, where it only reflects the 
 blue lustre ; both kinds, when viewed alone, with 
 the beautiful green felspar from Siberia, falsely 
 called the Amazon's stone (which was found near 
 the river of Amazons, in South America, and is a 
 jad), rather belong to gemmology, as they do not 
 constitute entire rocks. But the Labrador and 
 Norwegian rocks, considered as a compound, are 
 here classed in the Anomalous Domain. 
 
 Petuntze. 
 
 Kaolin. 
 
 Labrador, 
 
 Green of 
 Siberia. 
 
160 
 
 DOMAIN II. SILICEOUS, 
 
 Characters. 
 
 Palaiopetre. 
 
 Petrosilex of 
 Wallerius. 
 
 MODE IV. FELSITE, OR COMPACT 
 FELSPAR. 
 
 Texture, compact. 
 
 Hardness, felsparic. Fracture, minutely fo- 
 liated. Fragments, rather sharp, amorphous. 
 
 Weight, granitose. 
 
 Internal lustre, glimmering, or glistening. 
 Translucent, sometimes only on the edges. 
 
 Colours, various, as of felspar, which may also 
 distinguish it from keralite. Melts under the 
 blow-pipe. 
 
 It is doubtful if it form entire mountains; but 
 is an important rock, and among the most pri- 
 mitive. 
 
 It is the Palaiopetre of Saussure, who found it 
 near the summit of Mont Blanc ; and a speci- 
 men which he sent to Lametherie, and which I 
 have seen, is compact felspar, easily fusible by 
 the blow-pipe. 
 
 It is the petrosilex of Wallerius, and in conse- 
 quence of the Swedes and French; so that it 
 must be carefully distinguished from real petro- 
 silex, which literally implies the rock-flint of the 
 Germans, being a modification of quartz, and 
 not of felspar. The name felsite was very pro- 
 
MODE IV. FELSITE. 161 
 
 perly introduced by Mr. Kirwan ; as a distinc- 
 tion between it and keralite seems first to have 
 arisen from an accurate examination of the 
 beautiful blue granite, discovered near Krieglach 
 in Stiria, where it occupies the place of common 
 felspar. The distinction, which is thus recent, 
 forms an important step in the knowledge of 
 rocks. 
 
 Wallerius sent a specimen of his petrosilex to 
 France, which I saw in the possession of Haiiy, 
 being rose-coloured compact felspar, from Sal- 
 berg. Saussure mentions a grey felsite, explored 
 like slates near Martigny, in the valley of the 
 Rhone; and the celebrated cascade of Pisse 
 Vache falls from a rock of this kind*. His jad 
 is also now called compact felspar. Patrinf saw 
 in Siberia, near the celebrated silver-mine of 
 Zmeof, a mountain with singular natural forti- 
 fications, composed of felsite. They rise about 
 200 feet above the body of the mountain ; being 
 
 * 1046. Between Martigny and St. Maurice there is also a sin- 
 gular variety of rocks. Among them is a kind of petrosilex, grey, 
 hard, and sonorous, with a little transparency, which rises in thin 
 plates, perfectly flat and regular : hence it is used as a slate-quarry. 
 It is probably of the same nature with patrinite, or laminar felsite. 
 The rock of the famous cascade called Pisse Vache, seems of the 
 same kind, but approaching nearer to a feljad, greenish, and semi- 
 transparent. It melts like a felsite, but with greater difficulty. 
 
 f i. 134. 
 
 VOL. I. M 
 
DOMAIN 11. SILICEOUS. 
 
 on all sides as steep as a wall, and only pierced 
 with a few difficult openings. The summit forms 
 a platform, about 500 paces by 200, covered 
 with blocks and fragments of various kinds of 
 felsite, some laminar, others veined in zigzag. 
 Some have the triangular form of half a cube, 
 cut by its diagonal 5 and one large mass is com- 
 posed of angular fragments of felsite, in a paste 
 of the same substance, so as to constitute a bricia. 
 
 When Dolomieu wrote, the knowledge of 
 rocks was far from having attained even the pre- 
 sent degree of precision ; which is however so 
 far from being perfect, that perhaps another en- 
 lightened century may elapse, before all the 
 rocks shall have been discovered, analysed, and 
 examined, so as to be reduced to their proper 
 domains and modes. The following rock, with 
 a base of his petrosilex, which is felsite, probably 
 belongs to this division, though he mentions it 
 after the toad-stones and variolites*. 
 
 I must here mention some glandular stones 
 
 Corsica. 
 
 which I found in Corsica, chiefly in the valley 
 of Nidof, and which have petrosilex for a basej 
 none have appeared to me more curious nor 
 more instructive. The very fine paste, which 
 forms the ground of the mass, is of different 
 
 * Journ. de Phys. 1794, p. 260, note, 
 t Niolo? 
 
 
MODE IV. FELSITE. 
 
 colours, white, grey, red, or brown. The glo- 
 bules, whose growth may be traced from the 
 instant when, having a diameter of half a line, 
 they begin to be apparent, till they have acquired 
 an inch in size, are generally black, with an 
 aspect of horn, sometimes brpwn or red, but 
 always of a different colour from the base : they 
 are striated from the centre to the circumference, 
 and have almost always a small crystal of fel- 
 spar, or a grain of quartz, for a central point. 
 Sometimes the gland is not completely formed ; 
 its place is only marked by the circular spot 
 round the central grain. The greater part of 
 these glands adhere strongly to their base, per- 
 fectly incorporating with it : some, but not those 
 which are striated, may be detached, and leafe 
 their impressions. It seems to be a mixture of 
 steatite which favours their separation. These 
 globules, which are not always harder than the 
 paste which contains them, are affected by fire 
 like petrosilex; and only seem to differ from 
 their base by the kind of texture that a peculiar 
 aggregation has caused them to assume." 
 
 Dolomieu, following the observations of Saus- 
 stjre, 1079, has demonstrated*, that the petro- 
 silex of the Swedish and French authors is a 
 
 * Journal de Physique, new series, vol. i. p, 244. 
 M 2 
 
l()4i DOMAIN II. SILICEOUS. 
 
 compact felspar. It is sometimes of a greenish 
 hue, from a small quantity of steatite dissolved 
 in its paste ; and sometimes grey or black, from 
 a mixture of bitumen, as Dolomieu argues, from 
 its becoming white before it melts. Felspar often 
 passes into felsite, and the latter often contains 
 little scales or crystals of the former. 
 
 This ingenious, but prolix and discursive 
 T 7ei k sp n i! f author, distinguishes two kinds of felspar; that 
 which contains lime, and that which contains 
 magnesia. The latter is more hard and weighty, 
 and less fusible than the other; and as it ap- 
 proaches to the nature of jad, might, by a com- 
 plex term, alike useful for precision and the 
 Feijad. memory, be called feljad. Some granites present 
 both kinds, but felsite generally contains lime; 
 it is also found with crystals of schorl, plates of 
 siderite, or veins of quartz. 
 
 According to Dolomieu, felsite forms the base 
 of several porphyries found in the valley of 
 Niolo, in Corsica. One kind is green, and as 
 fine as chalcedony, sprinkled with an infinite 
 number of red dots, being little crystals of fel- 
 spar. A brown felsite porphyry, of a schistose 
 kind, is used for slates in the village of Pergine, 
 in the bishopric of Trent. 
 
 " The mountains of Tyrol, between Trent and 
 Bolsano, are almost entirely composed of por- 
 
MODE IV. FELSITE. 16*5 
 
 phyries, with a base of petrosilex of different 
 tints; and the little valley of Fierrozo, in which 
 flows the river Fersina, and at the entrance of 
 which is the village of Pergine, might be called 
 the valley of porphyries, from the infinite num- 
 ber of varieties which that rock there presents, 
 always preserving the same base. There are 
 grey, green, red, brown, black. There are some 
 similar to bricias, of a green cement with pieces 
 of other colours. The petrosilex in it gradually 
 passes to the granitic texture, and to th^ a 'tate of 
 schistose rock, without the beds changing their 
 direction."* 
 
 STRUCTURE I. COMMON. 
 
 Rose-coloured felsite, from Salberg, in Sweden. 
 This is interesting, as being the petrosilex of Wal- 
 lerius, which led to many errors of the Swedish 
 and French writers. He describes the following 
 kinds f. 
 
 A scaly grey petrosilex, from Salberg. 
 
 A scaly brown, from Garpenberg. 
 
 The red scaly petrosilex, from Dalecarlia. 
 
 The green scaly petrosilex, from the same. 
 
 The blackish scaly, from Dannemora. 
 
 He then describes several specimens of a waxy 
 
 * Ib. 247, note, t i. 280. 
 
1(56 DOMAIN II. SILICEOUS. 
 
 fracture ; and observes, that his petrosilex some- 
 times runs in layers in calcareous mountains ; so 
 that he has confounded the secondary horn stein 
 with the primitive felsite. When a stone passes 
 into jasper, it must properly belong to keralite or 
 rock-flint, which, like jasper, is infusible. 
 
 STRUCTURE II. LAMINAR. 
 
 This kind is observed by Saussure as already 
 menti^^d. It has been confounded by some with 
 keralite or hornstein. 
 
 Kiinstein. The clink-stone of Werner, sometimes ridicu- 
 lously called basalte en tables by the French mi- 
 neralogists, may properly be classed under this 
 division, as having no connexion with the basaltic 
 modes, which are characterised by the abundance 
 of iron, but most intimate relations with felspar, 
 as will appear from the following analyses by 
 Vauquelin and Klaproth : 
 
 FELSPAR. KLJNGSTEIN. 
 
 Silex . . 62,83 57,25 
 
 Argil . . 17,02 23,50 
 
 Lime . . 3,00 2,75 
 
 Potash . . 13,00 . Soda^ . . 8,10 
 
 Iron . . . 1,00 (sianganese 0,25) 3,&5 
 
 Loss . . 3,15 (water3) . 4,9 
 
 100 100 
 
MODE IV. FELSITE. 
 
 167' 
 
 The kliagstein porphyry of Werner, which he 
 also absurdly calls porphyry slate, is a schistose 
 felsite, with crystals .of felspar; as it happens in 
 many substances that an earthy and compact base 
 is spotted with crystals of the same substance, the 
 forms of some of the molecules having disposed 
 them to crystallise, while the others became sedi- 
 mental. The klingstein porphyry is generally black 
 or grey, but sometimes of a green, yellow, or 
 brown tinge, like the klingstein, which seems to 
 admit most of the colours of felsite ; but is of a 
 schistose texture, and contains little cavities, often 
 lined with quartz crystals, much resembling lava 
 with a basis of felsite. 
 
 As the French seem first to have observed this 
 rock, it may be called patrinite, in honour of Pa- 
 trin, an eminent French Geologist and Volcanist. 
 It sometimes contains zeolite, calcareous spar, and 
 crystals of siderite. Mr. Jameson has observed 
 that it is sometimes vesicular*, or full of little 
 cavities, " but not so much so as basalt." Part 
 of his description of patrinite may be transcribed. 
 " 2. It occurs sometimes in tables and columns ; 
 also in veins that traverse sand-stone and green- 
 stone, as in the island of Arran. 
 
 " 3. It resists the action of the weather very 
 
 Patrinite. 
 
 Jameson's 
 description. 
 
 * This epithet seems only applied to basalt, wacken, klingstein, 
 ava, pumice. 
 
168 DOMAIN n. SILICEOUS. 
 
 obstinately. After very long exposure it becomes 
 covered with a thin crust, which has usually a 
 greyish-white colour, but a reddish crust in iron- 
 shot varieties. 
 
 " 4. Like basalt it forms single conical hills ; 
 but they are not so regular, and are more marked 
 with cliffs and irregular rocky forms. 
 
 " 5. Excepting small traces of iron-pyrites, and 
 iron-sand, it contains no ores. 
 
 " 6. It appears from observations I have made 
 in the islands of Arran and Lamlash, in Dumfries- 
 shire, and on the porphyry-slate hills near Edin- 
 burgh and Haddington, that this rock passes, on 
 the one hand, into compact felspar and clay-stone, 
 and, on the other, into pitch-stone and basalt. 
 
 " 7. It occurs abundantly in the islands of Arran 
 and Lamlash, in the frith of Clyde ; also in smaller 
 quantities in the upper part of Dumfries-shire, 
 and in the county of Selkirk. Braid hills, and 
 part of the Pentland hills, near Edinburgh; the 
 Girleton hills afc Haddington, and, according to 
 my pupil Dr. Ogilvy, North Berwick Law, and 
 Traprain or Dumpender Law, in the same county, 
 are composed of this rock. I suspect that the 
 porphyry of Cumberland, which probably occurs 
 among transition mountains, is also porphyry- 
 slate. It occurs in great abundance in Bohemia ; 
 also, but in less quantity, in Lusatia; in the prin- 
 
MODE IV. FELSITE. 1(>9 
 
 cipality of Fulda ; in the Rhongebirge ; at Hohen- 
 tinel and Hogau, in Upper Suabia ; at Vicenza, 
 in the Euganean mountains ; on the Pic de Teyde, 
 in Teneriffe; and in great abundance in South 
 America, as I suspect that much of the porphyry 
 of Humboldt will prove to be porphyry-slate." 
 
 It may likewise be observed, from Brochant's 
 description, that patrinite sometimes occurs in glo- 
 bular masses, implanted in other rocks ; and also 
 sometimes assumes the prismatical form, in groups 
 of more or less regularity. 
 
 To these remarks may be added the curious 
 description by Klaproth, which accompanies his 
 analysis. 
 
 " The schistpse-porphyry is a species of stone, 
 which, notwithstanding that it so frequently occurs, 
 and even in masses forming entire mountains and 
 rocks, yet was doomed by a singular fate long to 
 continue to be disregarded, unknown, and con- 
 founded with other stones. 
 
 "The first denomination, under which it has 
 been admitted in oryctognostic treatises, is that of 
 hornschiefer (horn-slate). However, this name 
 does not exclusively belong to it ; for which reason 
 various authors denote by the same name several 
 different species of stones. This German deno- 
 mination seems to have been occasioned by the 
 Latin corneus fssilis of Walkrlus ; though it is 
 
170 DOMAIN II. SILICEOUS. 
 
 obvious from the description which he has given 
 of his corneusjissiliS) that he did not mean to sig- 
 nify by that name our schistose-porphyry, which, 
 as it seems, he did not know r but the hornblend- 
 schiefer (hornblende-slate of Kirwan). 
 
 " Other authors, as Born, Ferber, receive under 
 this name, sometimes different varieties of the 
 thonschkfer (argillaceous slate), and sometimes 
 glimmer schiefer (micaceous slate). 
 
 " The first oryctologist who has awakened the 
 attention of naturalists to the schistose-porphyry, 
 and given of it an accurate description, was Char- 
 pentier, in his Mineralogical Geography of the 
 Electoral Dominions of Saxony. At the same 
 time he gave to it exclusively the name of horn- 
 slate, in which he was followed by most of the Ger- 
 man mineralogists. But Werner thought other- 
 wise. He left this name at first to that species of 
 stone, which afterwards has been called kiesel- 
 chiefer (siliceous slate); and denominated that 
 which is the subject of the present essay schistose- 
 porphyry , in order to distinguish it as a peculiar 
 species of porphyry. In fact, it exhibits the mi- 
 neralogical character of porphyry : as it princi- 
 pally consists of an homogeneous, hard, siliceous 
 and argillaceous aggregate, in which, though but 
 sparingly, and singly, are interspersed small la- 
 of feldspar, besides minute grains of horn- 
 
MODE IV. FELSITE. Yf \ 
 
 blende; yet at the same time it is distinguished 
 from the common species of porphyry, by its gross 
 slaty fracture. But since to the principal mass 
 of this stone the name of Mingstein (sounding- 
 stone) has been given, because its larger plates, 
 when struck, give a sound almost metallic; it 
 seems that the name of klingstein porphyr (kling- 
 stone porphyry) would be more characteristic, and 
 more conformable to analogy. 
 
 " From this short historical account it may 
 sufficiently be seen, what great uncertainty and 
 want of accuracy has even of late prevailed in the 
 geological knowledge of the mountainous part of 
 the globe. For this reason the editor of the ma- 
 gazine for the Natural History of Swisserland has 
 highly merited the thanks of the public, for having 
 occasioned, by means of a prize question, that 
 this intricate subject has been investigated by two 
 learned mineralogists, Karsten and Voigt, and cor- 
 rectly explained in their two papers, crowned with 
 the prize : " On argillaceous schistus, horn-slate, 
 and on wake*." 
 
 " The klings tone-porphyry belongs to that divi- 
 sion of mountains which, by modern geologists, are 
 
 * ' ' Magazin fur die Naturkunde Helvetiens," by Dr. Hopfner. 
 Zurich, 1788. Vol. iii. page 168, seq. 
 
DOMAIN II. SILICBOT7S. 
 
 classed with the trap-mountains*. In Germany 
 it occurs chiefly in the middle mountains of Bohe- 
 mia, in Upper Lusatia, and in the district of Ful- 
 da. It does not form coherent ranges of moun- 
 tains, but always only detached masses of rocks 
 and insulated mountains, commonly on the side 
 of similar basaltic mountains. It belongs to the 
 most durable sax a, and resists the withering in an 
 eminent degree. Only on its surface some decay 
 takes place, by which it acquires a pale clayey 
 crust, -the smoothness of which renders the ascen- 
 sion on klingstone-porphyry mountains somewhat 
 unsafe. Some of these mountains, though but 
 sparingly covered with fertile soil, are nevertheless 
 well invested with plants and forest-trees ; as for 
 instance the Donnersberg, near Milleschau, and 
 the Schlossberg, near Toplitz. But most fre- 
 quently the klingstone-porphyry occurs in the 
 shape of cliffs, which are dentated in a grotesque 
 manner, from the unequal, mostly vertical, se- 
 
 * In the German trapp formation. This expression is now, 
 according to Emmerling, by the latest German mineralogists used 
 to signify all mountains constituted of grxinstein, amygdaloid, schis- 
 tose-porphyry, basaltes, and their subordinate species. All these 
 are called trapp-gelirge, since those saxa not only occur in moun- 
 tains of the same kind, but also very much agree in their geo- 
 gnostic relations ; so that evidently they are of the same formation. 
 Transl. 
 
MODE IV. FELSITE. 173 
 
 parations into large plates and ill-formed pillars. 
 Examples of such grotesque rocks, are the Biliner- 
 stein, near Belin, and the Engelhaus-berg, not far 
 from Carlsbad. 
 
 " To complete the history of this stone, I must 
 briefly notice an opinion which has of late been in 
 vogue, and even now seems to have its abettors. 
 I mean, that the klingstone-porphyry, as well as 
 the basalt, the amygdaloid (mandelstein), and 
 other trap mountains, have been considered as 
 volcanic productions, or lavas. It does not be- 
 long to the object of the present inquiry to repeat 
 and to examine what on both sides of the question 
 has been argued, and sometimes with violence 
 disputed. I shall only mention, that in the se- 
 veral attentive inspections with which I examined, 
 in the middle mountains of Bohemia, the sites of 
 basalt and klingstone-porphyry, I could not dis- 
 cover the least vestige of a crater, or other signs 
 of a volcanic nature ; no more than any other un- 
 prejudiced observer would have been able to find. 
 
 " To these short geognostic remarks I shall 
 now add the description of the external characters 
 of the mass, which chiefly constitutes the kling- 
 stone-porphyry. 
 
 " The colour of the klingstone is grey, now and 
 then a little inclining to the green. It occurs 
 only massive. It has a fine grain, an uneven, 
 
174 DOMAIN ii. SILICEOUS. 
 
 coarse-splintery, fracture, and bursts into thick 
 slaty fragments. The edges of its thin splintery 
 fragments are transparent. It is pretty hard, and 
 at the same time considerably tenacious. When 
 triturated, it yields a light grey powder. 
 " Its specific gravity is 2,575. 
 " The lamellae of a greyish white, strongly 
 splendent felspar, which are interspersed in its 
 smbstance, together with the very minute crystals 
 of a black hornblende, give to it the character of 
 porphyry."* 
 
 The result of the analysis is 
 
 " Silex 57,25 
 
 Alumine .... 23,50 
 
 Lime 2,75 
 
 Oxydofiron ... 3,25 
 Oxyd of manganese 0,25 
 
 Soda 8,10 
 
 Water 3 
 
 98,10 
 
 " The reflecting natural philosopher will know, 
 without my suggesting it, how to appreciate the 
 value of this discovery of the presence of soda, as 
 a constituent part, in a stone which occurs in 
 masses of the size of entire mountains. It opens 
 
 * Klaproth Anal. Essays, ii. 182. 
 
MODE IV. FELSITE. 
 
 175 
 
 to him a new view, and leads him a long step 
 farther in his geological inquiries. We now see 
 that there is no longer any occasion for the theory 
 hitherto prevailing, according to which it was ima- 
 gined necessary to consider all the soda, which in 
 nature occurs either in a free, that is uncombined, 
 or in the carbonated state, as an educt arising from 
 a decomposition of rock salt, or of sea salt, or of 
 that from saline springs, supposed to have been 
 carried on by nature, and to have taken place in 
 an unknown manner. 
 
 " The klingstone employed in the preceding ex- 
 periments was from the Donnersberg, near Mille* 
 schau, the highest of the middle mountains in 
 Bohemia. The whole mass of this majestic cone, 
 which is above two thousand five hundred feet 
 high, consists entirely of this stone. From its 
 summit the picturesque fields of Bohemia, extend- 
 ing for many miles around, present themselves to 
 the eye, collected as it were in a pleasing minia- 
 ture painting ; while at the same time, at a farther 
 distance on the eastern horizon, the Bohemian and 
 Silesian Giant-mountains, and on the west the 
 Franconian Fichtelgebirge (mountainous region), 
 are discovered. 
 
 " If we now reflect, that in this enormous mass 
 of rock, the soda constitutes nearly the twelfth 
 part of the whole, I hope it will not be thought an 
 
176 
 
 DOMAIN II. SILICEOUS. 
 
 exaggeration to say, that this mountain alone is ca- 
 pable of providing, for a long succession of years 
 to come, all Europe with sufficient soda; pre- 
 supposing, however, that expedients should be 
 devised to separate this alkali from the stone by a 
 cheap and profitable method*." 
 
 STRUCTURE III. EARTHY. 
 
 This is described by Saussure as of an earthy 
 or granular appearance, with long and irregular 
 crystals of black siderite, sometimes greenish. 
 The rock was mistaken for a sand-stone. He also 
 mentions, 1 1 36, a rock of a violet red, which he 
 conceives to consist of the earth of felspar not 
 crystallised. 
 
 Earthy klingstein-porphyry, from Mont Dor, 
 described by Daubuisson in his account of the 
 basalts of Auvergne. 
 
 The following varieties may also be added from 
 the former great petralogist : 
 
 Rocks of felsite, with veins which at first might 
 be taken for granite, but upon examination is 
 found to present only felspar and mica, and some- 
 times only felspar confusedly crystallised. Sauss. 
 1194. 
 
MODE V. GRANITE. 177 
 
 A rock of green and violet layers, being a kind 
 offelsite. Sauss. 1448. 
 
 What he calls a trap, with a paste of a greenish 
 grey felsite, and grains of quartz and felspar. 
 2043. 
 
 1558. The rotten-stone of England may be Rotten-stone* 
 regarded as a kind of tripoli, but is neither porous 
 nor of a slaty structure. He concludes that tri- 
 poli consists of a fine sand of felsite. 
 
 MODE V. GRANITE. 
 
 This important substance, which composes 
 the highest chains of mountains, and was used 
 by the Egyptians in the earliest monuments of 
 art, is chiefly composed of felspar and quartz, 
 which have been already described : a third sub- 
 stance is also indispensable in granite, namely, 
 either mica or siderite. And even when both 
 these latter are joined, the most exact mineral- 
 ogist or geologist could not refuse the strict ap- 
 pellation of granite, as different mixtures may 
 be found in no very remote parts of the same 
 rock. As some granites, instead of felspar, pre- 
 sent felsite, yet are universally admitted into this 
 class ; so the mica may pass into talc or steatite, 
 or siderite, as on the summit of Mont Blanc, and 
 VOL. T, N 
 
DOMAIN II. SILICEOUS. 
 
 the siderite into iron, without changing denomi- 
 nations. Crystals of schorl, or garnets, not to 
 mention the precious stones, may also appear in 
 genuine granite; but the real and severe deno- 
 mination can in no case be further extended. 
 When there are only two essential substances, 
 with a granitic appearance, as particularly 
 Granitei. quartz and felspar, the term granitel must be 
 admitted, with Saussure, Kirwan, and other ce- 
 lebrated geologists; though in Italy granitello 
 is used by artisans for a complete granite, com- 
 posed of very small grains, here called granitin; 
 as basaltin is a fine basalt, and porphyrin^ a fine 
 porphyry. 
 
 These observations become the more neces- 
 sary, as no substance has engaged more attention 
 in systems of geology, and no two authors seem 
 hitherto to be agreed in precise and formal 
 definitions of granitic substances : and in all 
 sciences it is well known that no question can 
 be settled, or even accurately discussed, without 
 the most precise definitions. Thus in the ques- 
 tion concerning the entrance of granitic veins 
 into primitive schisti, some deny that the granite 
 in these veins is of the same mixture with the 
 mass; and it certainly would considerably in- 
 fluence the discussion, if the mass be a complete 
 granite, and the veins only granitel. Nor in 
 
MODE V. GRANITE. 1 79 
 
 fact can there be any just science, if terms be 
 used in a lax acceptation; and it is far better 
 to err in the contrary extreme, which can only 
 be accomplished by increasing the number of 
 distinctions and denominations, as has been done 
 in gemmology. 
 
 As siderite has been shown to be among the Granite, with 
 
 sidente. 
 
 most primeval substances, and is found enclosed 
 in the crystallisation of the most ancient gra- 
 nites, so as to evince a priority of formation to 
 the quartz, or the felspar, which never appear 
 to be intercepted by the siderite; so it may be 
 assumed that a granite, consisting of felspar, 
 quartz, and siderite, with or without the addition 
 of mica, may be regarded as among the most 
 ancient, if not absolutely primary. Saussure 
 observes that there is no mica in the granite on 
 the summit of Mont Blanc, its place being sup- 
 plied by siderite ; and remarking the same dif- 
 ference to occur in the granite ejected from the 
 depths of the Italian volcanoes, he is led to the 
 reasonable conclusion, that this construction, 
 being found at the greatest heights and the 
 greatest depths, must be the most primordial. 
 It is also remarkable, that as the nucleus of the 
 earth is inferred by astronomers and natural phi- 
 losophers to consist of iron, which is seldom 
 found free from silex, so a great part of the sura- 
 
 N 2 
 
DOMAIN II. SILICEOUS. 
 
 mit of Mont Blanc consists of granitel*, or a 
 mixture of felspar and siderite ; and the base of 
 all lavas consists of one of these two substances. 
 Whether however we join the Huttonians, in 
 considering granite as the newest substance, the 
 last ejected from the bowels of the earth; or the 
 Wernerians, in regarding it as the most ancient, 
 being deposited from above, we must be allowed 
 to view a substance composed of felspar, quartz, 
 and siderite, as not only a complete and genuine 
 granite, but as perhaps the most noble denomi- 
 nation of that class. 
 
 As Mont Blanc is the most remarkable gra- 
 nitic mountain in the world, it may be instructive 
 to translate Saussure's curious and interesting 
 account of its summit. Of the rocks which that 
 great observer discovered near the summit of that 
 mountain, he gives the following description j 
 which shall be followed by that of the rocks 
 observed on the summit itselff . 
 
 * This, as Saussure especially mentions, 1Q94, was the syenite 
 of Werner at the time when he wrote, A. D. 1795; but Karsten 
 about the same period denned the syenite of Werner to consist of 
 quartz, siderite, and felspar. Jameson however regards syenite as 
 composed of felspar and hornblende; but Kirwan agrees with 
 Karsten. Daubuisson, who is commonly exact, says that syenite is 
 composed of felspar and siderite ; and that any quartz or mica is 
 accidental. 
 
 v f Saussure, 1999, supposes that the summit of Mont Blanc 
 was originally about two leagues under the surface of the earth. 
 
MODE V. GRANITE. 181 
 
 1987. " The naked rocks that we there meet Summit of 
 
 Mont Blanc. 
 
 with, and which form two kinds of arretes or 
 crests, of a black colour, and somewhat saliant, 
 which we clearly see from the banks of our lake 
 to the left of the highest summit of Mont Blanc, 
 are granites, here detached in scattered frag- 
 ments ; there, in solid rocks, divided by fissures 
 nearly vertical, whose direction is conformable to 
 that which generally predominates in these moun- 
 tains, that is, from the north-east to the south- 
 west, and which I consequently regard as layers. 
 
 " The felspar which enters into the compo- 
 sition of these rocks is white approaching to 
 grey, or green, or redish; it yields under the 
 blow-pipe a glass, from which we may obtain 
 globules of 0,6, transparent, colourless, but full 
 of bubbles. 
 
 " The felspar is here pure, there covered or 
 even mixed with a substance of a grey, inclining 
 to a sea-green, colour; without lustre, earthy, 
 soft; when scratched, whitish grey. This sub- 
 stance appears to be an earthy steatite; it is 
 difficult to obtain pieces of it free from felspar ; 
 those that I separated, melted under the blow- 
 pipe into a greenish glass, translucent, and of a 
 very unctuous aspect. They became discoloured 
 on the iron rod, and dissolved with effervescence. 
 
 " The whitish, semi-transparent quartz, which 
 
DOMAIN II. SILICEOUS. 
 
 enters into the composition of this granite, ap- 
 pears a little unctuous in its fracture 3 a frag- 
 ment, of the fifteenth of a line long by a thirtieth 
 in thickness, or of 0,067 by 0,033, fixed at the 
 extremity of a thin rod of iron, became perfectly 
 rounded in the flame of the blow-pipe, losing a 
 little of its transparency, which in this piece 
 appeared perfect, and some bubbles rose in its 
 interior. This quartz is therefore more fusible 
 than rock crystal, in the proportion of 0,035 to 
 0,014. 
 
 " These granites are frequently mingled with 
 hornblende, here blackish, there inclining to 
 green. 
 
 " There is also seen chlorite, often of a black- 
 ish green, sometimes in veins, sometimes in nests, 
 and even in pretty thick masses. It is soft, but 
 not friable; of a very fine grain, and its small 
 particles, viewed by the microscope, appear very 
 translucent thin plates, of a bright green ; but 
 they have not the regularity of those of St. 
 Gothard, which I have described in 1893. 
 This fossil, like hornblende, appears to retain in 
 these granites the place of mica, which does not 
 appear in it, except in very small and scarce 
 $pangles. 
 
 " Some of these granites appear curious, there 
 being small cavities of angular and irregular 
 
MODE V. GRANITE. ]$3 
 
 forms, full of a rust, or brown dust. In breaking 
 these granites, we find in their interior small 
 pyrites, brown and dull on the outside, but bril- 
 liant and of a very pale yellow within, and whose 
 fragments are attracted by the magnet. It is 
 from the decomposition of these pyrites, that the 
 cavities arise. My guides found fragments of 
 these granites, wherein were cubical pyrites from 
 three to four lines in thickness, whose fracture 
 is very brilliant, and of a very lively brassy yel- 
 low : these do not decompose in the air. 
 
 " We also find in these rocks quartz, with 
 veins and nests of delphinite, or green schorl of 
 Dauphiny (actinote) ; it is but confusedly crys- 
 tallised, but easily known by its puffing up un- 
 der the blow-pipe, and by the black and refrac-^ 
 tory scoria into which it is changed. 
 
 " In some parts these granites degenerate into 
 irregularly schistose rocks, composed of quartz 
 and felspar, without any mixture of mica, and 
 whose layers are separated and covered with 
 an argillaceous, nut-brown, ferruginous earth, 
 which melts into a black glass. 
 
 " These same rocks of granite contain a vein 
 of granitel almost entirely composed of laminar 
 black and brilliant hornblende, and of grey 
 translucent felspar, which assumes outwardly a 
 rusty colour. 
 
184 DOMAIN II. SILICEOUS. 
 
 " In short, my guides found also in these 
 same rocks a palaiopetre y or primitive petrosilex, 
 of a grey approaching a little to green, trans- 
 lucent at the thickness of a line, and even to 
 1, 2, scaly in its fracture, hard, interspersed in- 
 ternally with dots of a deep green, which are 
 scarcely visible but with a magnifying glass, and 
 which appear to be steatite ; and also some rare 
 dots of pyrites, which, in decomposing, stain of 
 a rusty colour the vicinity of the places they 
 occupy. This stone melts under the blow-pipe 
 into a white and bubbly glass, like that of the 
 felspar." 
 
 Our intelligent author thus describes the rocks 
 he observed on the summit itself of this cele- 
 brated mountain : 
 
 1990. " These rocks, situated nearly 2400 
 fathoms above the sea, are interesting by their 
 being the most elevated of our globe that have 
 been observed by naturalists. M. Bouguer and 
 de la Condamine ascended the Andes of Quito 
 to an equal height, and even some fathoms 
 higher than that of these rocks (2470 fathoms) : 
 they were not however acquainted with rocks; 
 but as they are said to have sent to France 
 chests full of specimens of the mountains, on 
 which their trigonometric operations had con- 
 ducted them, I could have much wished that 
 
MODE V. GRANITE. 1 $5 
 
 these specimens were examined by connoisseurs. 
 The late duke of Rochefoucault, a man equally 
 distinguished by his knowledge as by his virtues, 
 and who fell the innocent victim of the troubles 
 of a country for which he had made, and would 
 have yet made, the greatest sacrifices, was very 
 willing, at my entreaty, to make the most careful 
 researches after these specimens, either at the 
 King's garden, or at the Academy of Sciences, 
 of which he was a member ; but he was neither 
 able to discover them, nor any trace of what had 
 become of them. 
 
 " The scarcity of specimens of rocks situated 
 in similar heights, and the inferences we might 
 draw from their nature in different systems of 
 geology, induces me to give a detailed descrip- 
 tion of these. 
 
 " They are like those of 1987, granites in 
 mass, where hornblende and steatite hold the 
 place of mica, which is there extremely thinly 
 scattered; the sun and a magnifying glass are 
 necessary to enable us to perceive some white 
 and brilliant spangles; it is even doubtful if 
 these brilliant particles, which it is impossible to 
 detach, are really mica. 
 
 " Felspar forms the dominant part of these 
 granites; constituting about three fourths of 
 their mass. Their crystals, nearly parallelopi- 
 
DOMAIN II. SILICEOUS. 
 
 peds, vary as to size ; there are some which are 
 an inch long, by six lines broad. They are of 
 a dull white, slightly translucent, little brilliant, 
 of the kind I have called dry ; under the blow- 
 pipe they yield a transparent glass, but with 
 bubbles, from which may be formed globules of 
 0,81, and consequently fusible at the 70th de- 
 gree of Wedgewood. Upon the rod of sapparc 
 the bubbles dissipate, and there remains a trans- 
 parent milky glass, which sinks without pene- 
 trating or dissolving. These crystals of felspar 
 appear here and there greenish and dull, on 
 account of a slight coat of earthy steatite which 
 covers them. 
 
 <f The quartz, which forms a little less than 
 the fourth of the mass, As of a grey approaching 
 to violet colour; its fracture is uneven, brilliant 
 in some places, not scaly, but here and there 
 rather conchoidal, a little flat. Its fusibility is 
 nearly the same as that of the quartz of the gra- 
 nites of 198?. 
 
 " The hornblende, which forms in the mass 
 too small a portion to be estimated, is of a black 
 approaching to green ; it shows some tendency 
 to the laminar and brilliant form ; but it is more 
 often merely glimmering, and almost earthy; 
 fusible into a brilliant black glass, but porous in 
 its interior ; and which on the rod of sappare 
 
MODE V. GRANITE. 137 
 
 passes to the bottle green, through the brown; 
 afterwards loses its colour, and dissolves with 
 some effervescence, which proves there is a mix- 
 ture of magnesian earth. 
 
 " The earthy steatite, which also forms a very 
 inconsiderable part of the mass of these granites, 
 resembles that of 1987. 
 
 " All these granites have their natural divi- 
 sions covered with some coat, either green or 
 blackish. This is an earth like chlorite, of a 
 green almost black, and a little shining on its 
 external surface, but of a more bright green and 
 earthy in its fracture; soft, scratching with a 
 greenish grey streak ; at first turning brown un- 
 der the blow-pipe, then yielding a knob = 0,3, 
 or fusible at the 189th degree of Wedgewood. 
 This knob has a metallic aspect, somewhat un- 
 equal, and a little dull, like that of bars of melted 
 iron; and not only the knob, but all the parts 
 that the action of the flame renders brown, are 
 strongly attractable by the magnet. A small 
 fragment tried upon the rod of sappare, at first 
 infiltrates like ink between its fibres, then be- 
 comes of a dull brown, and at length entirely 
 discolours, but without any appearance of dis- 
 solution. 
 
 " The green coat which covers other pieces 
 of these granites in their spontaneous divisions, 
 
DOMAIN II. SILICEOUS. 
 
 is less dark, pretty shining, translucent, smooth 
 and even a little unctuous to the touch, soft, 
 easily scratched to grey, changing under the 
 blow-pipe into a translucent glass, which be- 
 comes transparent on the rod of sappare and 
 dissolves, but without effervescence. This coat 
 appears to be of the nature of steatite ; but I 
 have not been able to obtain pieces of it suf- 
 ficiently large to measure its degree of fusibility." 
 
 The rocks of the southern parts of this sum- 
 mit he thus describes, 1993 : 
 
 " 1. Granites perfectly similar to those before 
 mentioned, 1987. 
 
 " 2. Syenites or granitels, that is, rocks com- 
 posed of laminae of black hornblende and white 
 felspar, also laminar, but both in such small 
 parts, that we may as well give the name of 
 trap to these rocks, according to the definition 
 I have given in 1945. 
 
 " 3. A primitive petrosilex, or palaiopetre, of 
 a pearl grey, translucent to two thirds of a line, 
 with a scaly fracture in large and small scales, 
 sufficiently hard to yield bright sparks, but hav- 
 ing a grey streak when scratched by a sharp- 
 pointed steel. Under the blow-pipe we may 
 form globules of 0,45; which indicates the 
 fusibility of pig-iron, 126 or 130 of Wedge- 
 wood. It is a grey glass, semi-transparent, 
 
MODE V. GRANITE 189 
 
 bubbly, which on the rod of sappare gains in 
 transparence and sinks, but without penetrating 
 or dissolving, and even without entirely losing 
 its bubbles. 
 
 " This pala'iopetre contains veins of from one 
 to three lines in breadth, which cross at different 
 angles, and small nests of a deep leek-green horn- 
 blende, confusedly crystallised, or in plates rarely 
 straight, or in middling large fibres." 
 
 STRUCTURE I. OF A LARGE GRAIN. 
 
 Aspect 1. Felspar, quartz, and siderite, often 
 joined with mica. 
 
 Red granite of Egypt, from the quarries visited 
 by many travellers beyond Syene, whence it is 
 called Syenites, by Pliny, who specially mentions Syenites, 
 that the obelisks are composed of it ; while it is 
 universally admitted that they are a mere and ge- 
 nuine granite, often containing no siderite *. 
 
 * Both Agricola and Aldrovandi mention syenite: the latter 
 says, Fulgus qppellat hoc genus marmoris granitum rubrum cum 
 antea dieeretur pyrrhopoikilon ; the latter word being also used by 
 Pliny to denote the fiery red variegation of the felspar. 
 
 The celebrated Zoega also informs us positively that all the obe- 
 lisks are of the ancient Syenite, that is, as he adds, our red granite. 
 " Verum enimvero omnes obelisci in Europae civitatibus obvii, 
 ubi excipias unum Florentinum (e granite fusco), et maxima quo- 
 que pars eorum qui in /Egypto exstant, atque in Abyssinia ; faeti 
 
190 
 
 DOMAIN II. SILICEOUS. 
 
 The learned M. de Sacy, in his recent trans- 
 lation of Abd-allatif, or Abdolatiph*, who, about 
 A. D. 1210, wrote a curious account of Egypt, 
 uses the words elk est de, granit, de cette pierre 
 rouge, tiquetee, qui est d'une extreme durete. 
 
 It appears from the same work that some of 
 the pyramids were covered with granite, and even 
 with hieroglyphics ; which the Arabian author says 
 might fill a book of ten thousand pages. Gro- 
 bert, in his description of the pyramids, mentions 
 the fragments of that covering, as granite of rose- 
 coloured felspar, a little quartz, and black siderite, 
 like that of Elephantina, near Syene. This cover- 
 ing existed till at least the thirteenth century. 
 Curious authorities concerning the granitic column 
 called Pompey's, particularly that of Apthonius, 
 
 simte Syenite Japide, quern et pyrrhopwcilum vocat Plinius ; Itali 
 autem granito rosso, lithologi graniten ritlrutn." Zoega de Obeliscis 
 Romse 1797, folio, p. 140. 
 
 Petrini, on breaking some pieces, found that when there was 
 hornblende, it was always mixed with mica; as it is in the large 
 black spots. Ibid. 
 
 Granite seems first to be mentioned by a writer of the middle 
 ages, Vacca, whose description of Rome is published by Mont- 
 faucon in his Diarium Ifalicum. Vacca repeatedly mentions mar- 
 mor granitum JEthalios insulce, that is, " granite marble from the 
 isle of Elba," whence he supposed it came. The word granito is 
 probably as ancient as the restoration of the arts in Italy, in the 
 thirteenth century. 
 
 * Paris, 1810, 4to. p. 182. 
 
MODE V, GRANITE* 
 
 A. D. 400, may be found in the same work. It 
 belonged to the Serapeum, which was a noble 
 library, much reduced by Diocletian, when he 
 ordered the Egyptian works of alchemy to the 
 flames*. 
 
 The same, with large patches of siderite, in the 
 sphinxes of the museum at Paris. 
 
 The same, running in veins through grey gra- 
 nite. 
 
 Grey granite of Egypt, consisting of felspar, 
 quartz, and siderite : the psaronion of the ancients, 
 from its resembling the colours of a starling. 
 
 Black and white granite, consisting chiefly of 
 siderite with quartz, and a little felspar. 
 
 Dull green granite, of green siderite, with a 
 little quartz and felspar. 
 
 Yellowish granite, of granular quartz, yellowish 
 felspar, and greenish siderite, in large plates with 
 metallic lustre, from Zillerthal. 
 
 Red granite, of felspar, quartz, and hornblende, 
 from Peterhoff in Russia. 
 
 The same, from Mount Sorel in Leicestershire. 
 
 * Oros. vi. 15. Some theoretic French writers had inferred that 
 the Egyptians were negroes (in opposition to the mummies them- 
 selves), because they thought the Sphinx has negro features. Abd- 
 allatif, p. 179, tells us it was originally painted red, and the colour 
 was still fresh in his time ; nay Grobert, p. 32, observed a yellowish 
 tinge in parts not rubbed. 
 
192 
 
 DOMAIN II. 
 
 It also appears in masses on the road to Quarn- 
 don. 
 
 It is also found in Greece, Norway, Saxony, 
 the Hartz, Suabia, Stiria, Scotland, and many 
 other countries. 
 
 Aspect 2. Felspar, quartz, and mica. Red 
 granite of Egypt, without siderite, which, as Wad 
 justly observes, constituting all the obelisks, is the 
 real Syenites of Pliny. The mica is sometimes 
 greenish black, sometimes tombac brown, some- 
 times grey, sometimes black. 
 
 The same, variegated with grey felspar. 
 
 Grey granite, psaromon, of the same compo- 
 sition, from the same country. 
 
 Green granite. Of this I have only seen one 
 specimen, found by Roziere in the ruins of Om- 
 bos, in Upper Egypt. It is the most beautiful of 
 all the granites, the felspar being of the finest 
 emerald green, the mica silvery, and the quartz 
 transparent white*. 
 
 Blue granite, of white quartz, silvery mica, and 
 felsite of a sky blue, from Krieglach, in Stiria. 
 This granite, which is found in large masses in the 
 highway, only yields in beauty to the green of 
 
 * Besson, in his memoir on the granitel of Corsica ( J. de PA.) 
 mentions a granite of greyish quartz, and beautiful semi-transparent 
 green felspar. 
 
MODE V. GRANITE. 
 
 1.93 
 
 Egypt. Born says, that even the quartz is some- 
 times tinged with blue ; which may be the Prus- 
 siat of iron. 
 
 Red granite, with large mica, approaching to 
 talc, from Portsoy, Scotland. 
 
 The same, with crystals of schorl, from the 
 same place. 
 
 Red granite, joined with Tirey marble, from 
 the Isle of Tirey. 
 
 Rose-coloured granite, from the Lago Mag- 
 giore. 
 
 Brown, or Isabella colour, from the Vosges 
 mountains, France. 
 
 For the green of the Vosges, see Talcous rocks. 
 
 White granite, from the Alps, which are chiefly 
 composed of this substance. 
 
 Reddish granite, from the Carpathian moun- 
 tains. Born, i. 377. 
 
 Red granite, in which the felspar assumes a 
 round or oval form. This granite, found not far 
 from Petersburg, forms the basis of the statue of 
 Peter the Great. Patrin, i. 95*. 
 
 Pale yellow granite, from Greenland. 
 
 Granite, with pearl-coloured felspar, from 
 Austria. 
 
 Granite, with red felspar, and very long-grained 
 
 * Pini (Felspaths de Baveno, 177Q, 8vo. p. 41) mentions oval 
 crystals of felspar, like a cylinder on an oval base. 
 VOL. I. O 
 
DOMAIN II. SILICEOUS. 
 
 mica, which passes into siderite, from the cele- 
 brated quarry near Petersburg. Karsten Lesk. 
 Mus. 374. 
 
 Granite, with milk-white felspar, spotted with 
 red, from the same place. Ib. 
 
 Granite, with tombac brown mica, from Bo- 
 hemia. 
 
 Granite, with Labrador felspar, from Norway. 
 
 White granite, of w r hich the Escurial was built, 
 from Spain. 
 
 Violet granite, containing large crystals of vio- 
 let-coloured felspar, from the Isle of Elba. 
 
 Grey granite, from the Hartz. 
 
 White granite, from the Cevennes mountains. 
 
 Dark blue granite, from Brazil. 
 
 Black granite, with black felspar, from the Alps. 
 
 Grey granite, from Cornwall, the moorstone of 
 the country. It is white, with black and white 
 mica, large-grained, and takes a good polish. Da 
 Costa, whose book appeared 17,57, says, p. 273, 
 that it abounds with that kind of quartz which is 
 called felspar by the Germans. In the infancy of 
 the science the names of discrimination were very 
 few; and they will increase in proportion as it 
 advances*. 
 
 * In his Observations Mineralogiques sur les Vosges, Nancy, 
 1782, 8vo. Sivry informs us, p. 93, that, on a mountain near Giro- 
 magny, there occur Varieties of beautiful granites in detached blocks; 
 
MODE V. GRANITE. 
 
 The granites near the Hermitage, in Dau- 
 phiny, which yields the famous wine so called, 
 often present specks of a greenish black mica in 
 the very heart of the crystals of quartz; being 
 palpably the same mica which is interspersed 
 through the granite. Sauss. 1621. 
 
 A granite, which Saussure says is of a new 
 formation, crystallised in the crevices of mica 
 slate, mostly composed of felspar, partly also with 
 quartz and mica. 1267. 
 
 A granite, of which the quartz is of a lavender 
 blue, the felspar of a yellowish white, and the 
 mica, which is rare, of a dull leaden colour. 
 2144. 
 
 Granites with round crystals of felspar, like 
 that of Finland. 1195. 
 
 STRUCTURE II. OF A SMALL GRAUi'. 
 
 White granite, with black siderite, from Mount 
 Sinai. On this, according to tradition, the Laws 
 of Moses were engraved. 
 
 Red granite of Egypt, passing in a vein through 
 grey granite, with patches of siderite, brought by 
 Roziere from the quarries of Syene. 
 
 which, from the sharpness of their angles, and other symptoms, 
 seem even to have crystallised apart. These are, rose-colour with 
 green spots, black with white spots, green and white, grey with red 
 spots, brown with green veins. 
 
 o 2 
 
196 DOMAIN II. SILICEOUS. 
 
 Grey granite, of quartz felspar and sidente, 
 from Egypt. Wad. 
 
 Small or middling grained granite, with felspar 
 partly grey partly red, from Egypt. Wad. 
 
 Grey granite, from the same country, veined 
 with 'felspar partly grey partly red. Id. 
 
 Most of the kinds enumerated in the former 
 Structure may also be found in this. For the 
 smallest or very minute grained, see granitin. 
 
 Small grained white granite, with siderite, from 
 the summit of Mont Blanc. 
 
 White quartz, brown or reddish felspar, and 
 black siderite, from the Italian Alps. 
 
 The same, from the Isle of Elba. 
 
 Grey granite, with garnets, from Bohemia. 
 
 The same, from Norway and Scotland. 
 
 Grey granite, from Aleii9on. This is the com- 
 mon granite used at Paris. 
 
 Grey granite, with nodules of granitin, from 
 the Alps of Dauphiny. 
 
 Light grey granite, with red lines composed of 
 garnets, from Namiest in Moravia. 
 
 Grey granite, with veins of basal tin, from Nor- 
 w r ay. 
 
 Secondary granite, in thin layers, from the cave 
 fGribon, Isle of Mull 
 
MODE V, GRANITE. 197 
 
 STRUCTURE III. VEINED. 
 
 Saussure has described this rock with such 
 accuracy and precision, and has himself so distin- 
 guished it from gneiss, that it is surprising it 
 should since have been referred to the latter. In 
 gneiss the veins of mica run parallel through the 
 rock, which regularly splits in their direction. In 
 veined granite the seams of mica are irregular, 
 and terminate abruptly in various directions, being 
 met by the solid rock. 
 
 Saussure discusses, 1726, the differences be- 
 tween gneiss and his veined granite. In the latter 
 the elements are interlaced among each other; 
 while in gneiss there are fine leaves of pure mica, 
 which alternate with leaves composed of quartz 
 and felspar. 
 
 He mentions, 1799? an extent of more than 
 four leagues and a half of veined granite in hori- 
 zontal beds : and, 1 802, veined granite in double 
 zigzag, sometimes between other beds in right 
 lines, which proves, according to Saussure, that it 
 is the effect of crystallisation. That veined in zig- 
 zag is of a very fine kind, the quartz being scarcely 
 distinguishable, while the beautiful white veins 
 appear to be entirely composed of granular fel- 
 spar, resembling a small-grained marble. The 
 
 UNLVEKRTTV 
 
DOMAIN If. SILICEOUS. 
 
 mica is also in small spangles, some black, but 
 chiefly of a beautiful silver white. 
 
 STRUCTURE IV. MINGLED. 
 
 Some of this kind have already been incidentally 
 mentioned. Besides schorl and garnets, Saussure 
 observed chalcedony in granite, for which see the 
 Composite Rocks. Chlorite and actinote are not 
 uncommon in granite; and the talc sometimes 
 passes into steatite. Even calcareous spar has 
 been found in granite ; and, when decomposed, 
 porcelain earth, for which see the Decomposed 
 Rocks. Not to mention the metals ; primitive 
 gypsum, anthracite, gneiss, basalt, and other sub- 
 stances, also occur in granite. 
 
 Granite, in veins in schistus, Saussure, 599, 
 from Valorsine. He describes it as passing through 
 his roche de corne, which is generally a magnesian 
 basalt; the granite is of grey quartz, white fel- 
 spar, and grey mica, and is regarded by him as 
 formed by infiltration. 
 
 Granite, in veins in primitive slate, from Scot- 
 land. 
 
 Granite, with veins of granular quartz, from 
 Forez, France. 
 
 This account of one of the most important and 
 interesting rocks, shall be terminated by Zoega's 
 
MODE V. QRAN1TE. 
 
 ideas concerning the manner in which it was sculp- 
 tured by the ancients, as they may perhaps afford 
 useful hints to the modern artist"*. 
 
 " Some further observations occur -concerning 
 the Barberini obelisk, in the engraving of which 
 some instruments seem to have been used, of 
 which there is no vestige in the large obelisks; 
 for the straight lines, or those which form segments 
 of circles, are neither sharply cut, nor have they 
 an equal depth ; but the concave bottom is deeper 
 in the middle part, and fainter at each end, till 
 the lines gradually vanish. Nor do they terminate 
 precisely in the point assumed by the sculptor; 
 but the slender portion extends beyond the limits 
 of the figure. 
 
 " Hence it is clear that the furrows were not 
 made with a graver, nor with emery, rubbed as 
 usual with a blade in the form of a knife, but 
 with a kind of semicircular saw, to which emery 
 was subjected, and by alternate motions of that 
 instrument. But in the right lines only ; for where 
 they are curved the saw must also have been of 
 that shape. When however the figures, which 
 rise in the cavities, are more turgid, and each part 
 disfigured with some globosity, it is probable that 
 they were formed with a little auger or trepan, or 
 
 * For the original, see Appendix. 
 
00 DOMAIN II. SILICEOUS. 
 
 a kind of tube or hollow borer, by the assistance 
 of emery, although no vestige of such an instru- 
 ment appear, the surface of the figures having 
 been polished by friction. It was natural that 
 the artists should study to save time in this kind 
 of work, and effect by saws, tuctri, and friction, 
 what appears to have been accomplished in the 
 great obelisk by the chisel or graving tool, or 
 emery rubbed with a blade. 
 
 " 6. Our artists, when they wish to cut any 
 figure on granite, in the first place make a model 
 of a thin plate of iron, which being fastened to 
 the plane stone, they take another plate like a 
 short knife, and use it to cut a furrow, by the help 
 of emery, around the model first mentioned. The 
 furrow being thus impressed to a certain depth, 
 they take off the model, and begin to attack the 
 intermediate space with a sharp graver or chisel 
 called subbia. They then begin to form the figure, 
 with a little sharp hammer called pungetto ; and 
 afterwards soften it with a broader hammer called 
 martellino. This done, they polish it with lead 
 and emery ; and afterwards add the smaller linea- 
 ments, partly with a fine chisel, partly with the 
 blade in the form of a knife and emery. Lastly, 
 they polish the whole with the finest emery, called 
 spoltriglia. 
 
 " 7. Del Rosso thought he discovered marks 
 
MODE VI. GRANITIN. 201 
 
 of the auger in the obelisk of Heliopolis ; and 
 affirms, that without this instrument characters 
 could not be cut in a granitic rock. But he seems 
 to discuss a subject which he had not studied ; for 
 there could be no use for the common auger, also 
 called a trepan, in this stone, which is harder than 
 iron. But the other auger, which is a brass tube 
 contrived to act on emery, though a convenient 
 instrument, is yet unnecessary, and is only used 
 by our artists in forming deep furrows."* 
 
 MODE VI. GRANITIN. 
 
 When granite is composed of extremely mi- Description, 
 nute particles, it is not easily distinguished from 
 basalt, or rather from basalton, the grunstein of 
 Werner. But where particles of siderite, oY 
 even of basalt, which is an earthy siderite, are 
 mingled with particles both of quartz and felspar, 
 the substance is a granitin. When siderite is 
 mixed with felspar alone, it is basalton, or the 
 green-stone of Werner; the real basalt, or iron- 
 stone of the ancients, seeming properly to admit 
 of no mixture, except spangles of siderite. 
 
 Several ancient monuments, supposed to be 
 
 * Zoega de Obeliscis, p. 1 89, seq. 
 
DOMAIN II. SILICEOUS. 
 
 green basalt, are really of granitin with particles 
 of siderite, as micfa is never so much comminuted, 
 Granitin also often forms nodules, or veins, in 
 large or small grained granite, in almost every 
 country where that substance occurs ; but this 
 substance being rather of microscopic observa- 
 Green basalt, tion, the specimens are not common. Green 
 basalt, properly so called, should be homoge- 
 neous, or present only spangles of siderite ; but 
 may contain occasionally very minute particles 
 of quartz only. The Isis of the Capitol, Ferber, 
 231, is of granitin. 
 
 MODE VII. GRANITON. 
 
 When the crystals, especially those of felspar, 
 are extremely large, that is, from two to six 
 inches or more in length, the substance may 
 well be called a graniton. It is common in the 
 Alps, and other granitic mountains; and exam- 
 ples may be seen in the foot pavement of West- 
 minster bridge*. Graniton presents the com- 
 mon colours of granite, that is, white, grey, and 
 red. 
 
 * Mr. Smeaton says it came from Llanlivery, near Fovvey, in 
 Cornwall. 
 
MODE VIII. GRANITEL. 
 
 Graniton may also be denominated, from the 
 mica assuming the size of plates of talc. 
 
 Other aggregates, often confounded with gra- 
 nites, may be found in the division of Composite 
 Rocks. 
 
 MODE VIII. GRANITEL. 
 
 The mountains called primitive chiefly con- Definitions, 
 sist of four substances, blended in various mix- 
 tures, namely, felspar, quartz, siderite, and mica. 
 Without three of these substances the appel- 
 lations of granite become vague and improper \ 
 and have occasioned great confusion in orology, 
 or the description of mountains. Where only 
 two occur, the greatest of all geologists, Saus- 
 sure, has used the name granitel ; and his ap- 
 pellations, when not contradicted by necessary 
 distinctions arising from recent discovery, ought 
 always to be received with singular respect. 
 The term granitel is also confirmed and appro- 
 priated by the circumstance, that as the word 
 granite is now consecrated by universal and 
 perpetual usage, being derived from the Italian 
 granito, as presenting the appearance of grains 
 or kernels *; so a modification of granite ought, 
 
 * It has been ridiculously said^ that it is derived from the ge~ 
 ranites of Pliny ; which would only imply a stone shaped like a 
 
04) DOMAIN II. SILICEOUS. 
 
 in due analog jr, to receive its name from the 
 same language. 
 
 Granitel sometimes consists of as minute par- 
 ticles as granitin, so as to assume the appearance 
 of a coarse basalt. From this confusion, as 
 Wad observes, some of the Italians denote the 
 same substance granitello verde di Egitto, which 
 others call basalte verde. He describes two spe- 
 cimens*: " 1. Granite with very minute grains, 
 consisting of greyish white felspar, and siderite 
 of a dark green, in equal portions. 2. Granite 
 of a very small grain, composed of greyish white 
 felspar, and greyish black siderite, mixed with a 
 larger portion of olive-green siderite, which ren- 
 ders the rock green." 
 
 ^ r> Kirwan has justly observed, that the sim- 
 ple addition of mica to any stone, cannot alone 
 entitle it to be placed in the granitic division, as 
 mica does not form a grain, but attaches itself 
 indifferently to many sorts of stones ; for there 
 are micaceous limestones, micaceous sandstones, 
 micaceous serpentines, &c. &c. Mica must 
 therefore be totally excluded from the granitels; 
 and felspar with mica, or quartz with mica, can 
 
 crane's bill, geranium ! But Pliny says himself, xxxvii. 1 1, a gruis 
 collo geranites. See Laet, p. 170, for a print of a Geranites. For 
 the first appearance of the word granito, see a former note. 
 * Fossil JEgyp* ? 7- 
 
MODE VIII. GRANITEL. 205 
 
 only be properly classed with the simple rocks 
 of felspar or of quartz. There are therefore only 
 three genuine structures of granitel; namely, 
 1. Felspar with siderite. 2. Felspar and quartz.' 
 3. Quartz with siderite. 
 
 STRUCTURE I. WERNERITE, FELSPAR WITH SIDERITE. 
 
 The appellation has been derived from this Wernerite. 
 celebrated mineralogist, who well deserves to give 
 his name to one of the most important substances 
 in nature. It is also intended to compensate, * 
 
 while it calls to memory, his noted syenite, a term 
 so ill chosen as to have introduced confusion, in- 
 stead of illustration. The syenite of Werner, as 
 already mentioned, consists of felspar with side- 
 rite, that is, the former is more abundant; but 
 in basalton, or grunstein, the siderite predomi- 
 nates, and gives a black or greenish colour ; while 
 Wernerite is generally reddish. Yet the syenite 
 of Werner sometimes contains quartz and black 
 mica, which infallibly constitute a granite; and 
 the stone should, in that case, be said to pass into 
 granite. The appellation of Wernerite is here 
 strictly confined to a mere arid sole admixture of 
 felspar with a smaller portion of siderite ; and as 
 colours form the meanest of all distinctions, no 
 consideration is paid to that circumstance. 
 
206 DOMAIN II. SILICEOUS. 
 
 Wernerite of white felspar and black siderite, 
 from Mount Sinai. It sometimes passes into 
 granite; and is reported by tradition to be the 
 stone on which the commandments were en- 
 graven. 
 
 .Of red felspar and black siderite, from the 
 Alps. It is sometimes mixed with mica, o/schorl; 
 and if quartz were present, it would then consti- 
 tute a granite. 
 
 Of grey felspar and black siderite, from the 
 ejections of Vesuvius. These substances united, 
 or distinct, may be said to form all the lavas. It 
 is sometimes mixed with garnets or actinote. 
 
 Wernerite of grey felspar with black horn- 
 blende, forming a vein in granite, on the summit 
 of Mont Blanc. Saussure, 1 987. 
 
 Wernerite, from Muhr in Stiria. 
 
 Wernerite, in rolled pebbles, from the Lake of 
 Geneva. 
 
 Of brownish red felspar and black siderite, 
 from Leipzig. 
 
 Of reddish white felspar and black siderite, 
 from the Hartz. 
 
 STRUCTURE II. LEHMAN1TE, FELSPAR WITH QUARTZ. 
 
 This name is given to a primitive substance, 
 from the celebrated Lehman, who first pointed 
 
ttODE VIII. GRANITEL. 207 
 
 out the distinction between primitive and second- 
 ary mountains. 
 
 Lehmanite of felspar and quartz, from Corn- 
 wall. 
 
 The same of white quartz and red felspar, from 
 Scotland. 
 
 It is common in the Alps, and other chains of 
 mountains. 
 
 Lehmanite of a reddish white, from Sweden*. 
 
 Lehmanite, from Grimsel. It is also found in 
 Nassau and Siberia, and near Portsoy, in Scot- 
 land. Linnaeus, by Gmelin, 214. 
 
 Of a yellowish white, from Finland. 
 
 Da Costa says, p. 278, that part of Newry, 
 Ireland, is built of this stone, there called mountain 
 grit. Another part is of felspar and large green 
 mica. 
 
 STRUCTURE III. ENKELITE, QUARTZ WITH SIDE RITE. 
 
 The name is derived from Henkel, who may be Henkefit*. 
 ranked among the fathers of lithology. The al- 
 liances between quartz and siderite seem to be 
 rather uncommon, felspar having been commonly 
 mistaken for the former substance, 
 
 Henkelite, from Switzerland. 
 
 * Wall. i. 422. 
 
DOMAIN II. SILICEOUS. 
 
 In Switzerland it often contains garnets. , 
 
 The same, from Altenberg, in Saxony*. 
 
 The basaltic granite of Wallerius, from Suder- 
 mania. It is either black, yellowish, or greenish. 
 
 The same, of an iron colour, from Norberg, in 
 Sweden; but this seems rather to belong to the 
 siderous division. 
 
 Henkelite is also found in Bohemia, Saxony, 
 Tyrol, Stiria, &c. It is believed that the ancient 
 black and green granites, so called, often consist 
 of this substance f. 
 
 STRUCTURE IV. MINGLED. 
 
 The most usual parasitic stones of granitel are 
 schorl and garnets, both composed in a great part 
 of iron. 
 
 Wernerite, with garnets, from Vesuvius. 
 
 The same, with actinote, from the same. 
 
 Lehmanite, with steatite, from the Alps. 
 
 Henkelite, with garnets, from the Alps. 
 
 The same, with steatite, from the same. 
 
 The same, with schorl, from the same. 
 
 * Linn. 218. 
 
 f Launay, Essai sur 1'histoire natureile des Roches, Bruxelles 
 1786, 12mo. p. 41. 
 
DOMAIN II. SILICEOUS. 209 
 
 MODE IX. GRANITOID. 
 
 Many rocks, inaccurately classed among gra- 
 nites, are reserved for the Composite Domain. 
 Such alone as perfectly resemble granite, but 
 are of a very different modification, are here 
 styled granitoids; and this denomination pre- 
 sents three different structures. 
 
 STRUCTURE I. CALCAREOUS GRANITE. 
 
 In this rock lime-stone supplies the place of fel- 
 spar. This substance was first mentioned by 
 Kalm, as forming chains of mountains in Canada. 
 It was afterwards described by Saussure. Wer- 
 ner told me that he regarded it as a truly primi- 
 tive lime-stone. 
 
 Calcareous granite, from the mountains of Ca- 
 nada. 
 
 The same, from the vicinity of Mount Cenis. 
 But in the Alps it more commonly assumes the 
 form of gneiss, as at Roth Horn, Mont Cervin, &c. 
 
 Reddish calcareous granite, or primitive lime- 
 stone with quartz and mica, from Scotland*. 
 
 * The Journ. de Ph. 17Q1, mentions a calcareous granitoid, the 
 lime-stone or spar being in globules of an oval form, with crystallised 
 facetts, and compressed horizontally. 
 
 VOL. I. P 
 
DOMAIN II. SILICEOUS. 
 
 STRUCTURE II, ARGILLACEOUS. 
 
 This rock is more often the product of decom- 
 position, which changes the felspar into clay. 
 
 Argillaceous granite, with quartz, mica, and 
 martial clay, from Hungary and Sweden. 
 
 STRUCTURE III. TALCOUS. 
 
 From this division talc, and even steatite, must 
 be excluded, as being often mere modifications or 
 decompositions of mica. 
 
 Granitoid of felspar, quartz, and serpentine, 
 from Transylvania* 
 
 MODE X. GRANITIC PORPHYROID. 
 
 Description, In this substance, which is very frequent in 
 nature, some large or distinct crystals of felspar 
 are sprinkled on a base of granitin; and the 
 base being here assumed as the only ground of 
 classification of the substances vaguely called 
 porphyries, it must of course fall into this divi- 
 sion. The base may consist of quartz, felspar, 
 and siderite; or quartz, felspar, and mica; or 
 even any two of these substances. Some of the 
 
MODE XI. GNEISS. 
 
 porphyries of Saussure, $ 150, belong to this 
 class ; but granitic porphyroids are so abundant 
 in all primitive mountains, that it is scarcely- 
 necessary to select examples, being a mere va- 
 riation in the construction of granite or granitin. 
 
 Granitic porphyroid, from Mount Cenis. 
 
 The same, from Cornwall, Wales, Scotland, 
 the Vosges mountains in France, the Alps, 
 &c. &c. 
 
 Saussure, 155, gives some curious observa- 
 tions on the transitions from granite to granitic 
 porphyry. A great portion of Forez is of por- 
 phyry; while the adjacent portion of Auvergne 
 is granitic. 
 
 MODE XI. GNEISS. 
 
 When the materials of granite are disposed in Distinctions, 
 thin layers, or plates, the substance assumes the 
 name of Gneiss ; which consequently consists of 
 quartz, felspar, and mica. In his two first vo- 
 lumes, published before Werner had introduced 
 greater precision into the science, Saussure has 
 sometimes used the term veined granite, to ex- 
 press what is now denominated gneiss. But in 
 his latter volumes, as already explained, his 
 reined granite differs from gneiss, as presenting 
 
DOMAIN -II. SILICEOUS. 
 
 only short and irregular veins, terminating in 
 solid masses; while in gneiss the veins are uni- 
 form, and regularly divide the whole, as in slate, 
 or in other substances properly schistose Hence 
 gneiss has also been called schistose granite by 
 the French, and other writers. 
 
 In gneiss the mica is generally more abund^ 
 ant, as dividing the substance into regular plates. 
 Sometimes the place of mica is supplied by 
 siderite, which, as already explained with regard 
 to granite, cannot be regarded as altering the 
 denomination, but is only a proof of greater an- 
 tiquity. The siderite is also sometimes inter- 
 spersed in thick layers, or even beds. One of 
 the most interesting kinds of gneiss, is that with 
 Red. red felspar, sometimes of a wavy or undulated 
 structure, and which is also considered by some 
 as the most ancien . This, like other schistose 
 
 contorted, substances, is found contorted, or convoluted, in 
 fantastic forms; by some regarded as originating 
 from internal expansion or disturbance; while 
 others consider it as the mere effect of a parti- 
 cular crystallisation. 
 
 Primary. Geologists in general have considered granite 
 as the oldest substance, the fundamental rock 
 which supports all the others: the Huttonians 
 however regarding it, on the contrary, as the 
 newest substance, which, being elevated by ex- 
 
MODE xi. GNEISS: $ I 3 
 
 pansion, has broken the other stratifications. 
 However this he, it is certain that gneiss has, in 
 the grand example of the Alps, been found un- 
 der granite confessedly primitive; and they are 
 often found alternating with each other. The 
 lofty mountain of Rosa, which only yields in 
 height to Mont Blanc, instead of being com- 
 posed of arrects or uprights*, that is vertical 
 layers, or plates like the latter, presents, on 
 the contrary, horizontal beds of veined granite, 
 gneiss, and other schistose substances f. 
 
 Intermixed with gneiss are sometimes three 
 principal rocks, all regarded as primitive; lime- 
 stone, siderite either solid or schistose, and por- 
 phyry. But these substances equally appear 
 intermixed with granite, only alternating verti- 
 cally; while in gneiss they present horizontal 
 beds. In the old Egyptian monuments nothing 
 is more common than to find large masses of 
 siderite intermixed with the granite; and even 
 basaltin often penetrates that substance. The 
 Egyptian monuments of mica slate, described 
 by Wad, may perhaps more properly belong to 
 
 gneiss. 
 
 * In a new science new words must be admitted. Saussure, 
 and others, have long lamented the absurdity of vertical leds or 
 layers. Arrects or uprights would supply the deficiency. 
 
 f Sauss. 2138. 
 
214 DOMAIN II. SILICEOUS. 
 
 Primitive lime-stone likewise alternates with 
 granite, and has even been found to assume the 
 granitic forms. The alternation of porphyry 
 with granite is of general observation in all pri- 
 mitive mountains. 
 
 F metSlig in Gneiss also frequently contains garnets, acti- 
 note, magnetic iron, and pyrites. It is, after 
 clay-slate, the most metalliferous of all rocks. 
 The chief mines of Saxony, Bohemia, and Salz- 
 burg, are situate in this rock, which, though 
 very common on the Continent, is comparatively 
 rare in Great Britain and Ireland. 
 
 STRUCTURE I. TABULAR, OR IN THICK SCHISTOSE 
 FORMS. 
 
 This kind is commonly derived from granite, or 
 passes into that rock. 
 
 Tabular gneiss, from the Alps. 
 
 The same, from the isle of Leuis, in the exte- 
 rior chain of the Hebudes, Scotland. 
 
 STRUCTURE II. LAMINAR. 
 
 This is the common appearance of gneiss, and 
 may be divided into two Aspects. 
 
 Aspect 1. Plane or level. Gneiss, with red 
 felspar, from the Alps, Norway, Saxony. 
 
MODE XI. GNEISS. 
 
 Gneiss, with white felspar, from the same coun- 
 tries, Salzburg, Greece, &c. It is a common, and 
 seems a fundamental rock in the Brasils. Mr. 
 Jameson says, that it is found in the isles of Coll, 
 Tirey, and Rona; also in the Shetland isles, and 
 many parts of the main land of Scotland. 
 
 Aspect 2. Undulated. This is more uncommon 
 than the former. 
 
 Undulated red gneiss, from the Alps of Dau* 
 phiny. 
 
 The same, singularly contorted, from the same 
 site. This forms a remarkable diversity. 
 
 Red gneiss, from Norway. 
 
 Grey undulated gneiss, from the same countries. 
 
 STRUCTURE III. IRREGULAR. 
 
 In this kind the layers intersect each other irre T 
 gularly, in the form of wedges, &c. It differs 
 from the veined granite of Saussure, because the 
 divisions do not terminate in massy portions, but 
 are continued in oblique and irregular directions. 
 
 Red irregular gneiss, from the Alps, Norway, 
 &c. 
 
 Grey, from Brasil, and other countries. 
 
216 DOMAIN II. SILICEOUS. 
 
 STRUCTURE IV. COMPOSED OF TWO SUBSTANCES. 
 
 Interesting examples of this kind occur at the 
 mines of Salzburg, and particularly at those of 
 Macugnaga, near Mount Rosa, in the north of 
 Italy. This rock has always been called gneiss, 
 but is composed of thickish plates of quartz, with 
 thin seams of foliated mica, or rather steatite. 
 Gneiss also occurs composed only of felspar and 
 mica. As the first of these kinds has been chiefly 
 observed in Italy, I would propose to call it 
 Pi 11 ** 6 ? from Pini, an illustrious geologist, who 
 explored the southern Alps. The other may be 
 called Ferberite, an honour due to Ferber, whose 
 travels illustrate many parts of Italy, and the 
 south of Germany. 
 
 Aspect 1. Finite of quartz and steatite, from 
 Macugnaga, near Mount Rosa. 
 The same, from Salzburg. 
 
 Aspect 2. Ferberite, from the Alps, &c. 
 Gneiss also occurs of quartz and siderite, and 
 of felspar and siderite. 
 
MODE XT. GNEISS. 
 
 STRUCTURE V. MINGLED. 
 
 Grey gneiss, with garnets, from Bohemia. 
 
 The same, with actinote, from the same. 
 
 The same, with pyrites, from Bohemia. 
 
 The same, with different metals, from various 
 countries. 
 
 Finite, with gold pyrites and native gold, from 
 Macugnaga. 
 
 The same, with native gold, from Salzburg. 
 
 The following examples of various kinds may 
 be added, from Saussure : 
 
 A remarkable gneiss, of a bluish grey mica, in- 
 closing long grains of quartz and felspar, which 
 appear like sand, but are in fact crystals more or 
 less regular. 12Q1. 
 
 A gneiss, composed of irregular layers of white 
 granular quartz, and leaves of a substance inter- 
 mediate between slate and steatite. 2044, 
 
 A fine gneiss, composed of black mica, ap- 
 proaching in splendour to graphite, intermixed 
 with particles of felspar, and sprinkled with small 
 garnets. 1732. 
 
 A gneiss, composed of grey felsite and grey 
 mica. 1877. 
 
 A gneiss of foliaceous mica, with plates of 
 quartz, sometimes mixed with felspar, forms the 
 
DOMAIN II. SILICEOUS. 
 
 mountain which contains the copper mines of St. 
 George. 1201. 
 
 Werner has a large piece of massive granite, 
 inclosing rolled pebbles of gneiss. 2143. Saus- 
 sure gives, 661, examples of granite imbedded 
 in mica slate, or rather gneiss. 
 
 In the mountains on the south-east of the valley 
 of Chamouni, the inferior parts are gneiss, while 
 the summits are granite. 677. 
 
 Mount Rosa is wholly composed of veined gra- 
 nite, gneiss, and schistose rocks, from the base to 
 the highest summits. 2 1 38, 
 
 MODE XII. PITCH-STONE. 
 
 Characters. Texture, impalpably fine, resinous. 
 
 Hardness, basaltic, sometimes felsparic. Frac- 
 ture, conchoidal; if impure, splintery or coarse- 
 grained. Fragments, irregular and sharp. 
 
 Weight, carbonose. 
 
 Lustre, from glistening to splendent, resinous. 
 Somewhat translucent; but the black only on 
 the edges. 
 
 The colours are various shades of black, and 
 sometimes grey, brown, red, seldom green ; but 
 the tints are commonly pale, 
 sues. Pitch-stone forms entire mountains in Mis- 
 
MODE XII. PITCH-STONE. 
 
 nia ; and in other mountains of that country it 
 forms large strata, that alternate with porphyry*; 
 and as they contain abundance of quartz and 
 felspar, may be called pitchstone-porphyry, for 
 which see the Siliceous Intrites. 
 
 Pitch-stone is universally regarded as a pri- 
 mitive rock ; but it is also often found second- 
 ary, and constituting the substance of petrified 
 wood. In the island of Arran it forms large 
 veins in sand-stone; and it also occurs in Mull 
 and Eig. This curious and important substance 
 seems unknown to Wallerius ; but Gmelin, in 
 his edition of Linnaeus, has called it opalus piceus, 
 and mentioned many of its sites, as Iceland, the 
 isle of Elba, Auvergne, Transylvania, Hungary, 
 the Reisgeberg mountains in Germany, and New 
 Spain. It sometimes occurs in basalt. 
 
 STRUCTURE I. COMPACT. 
 
 Pitch-stone, from Meissen in Saxony, where it 
 was first observed. 
 
 The same, dark red, from Korbetz in Saxony. 
 
 The same, spotted with black, from Upper 
 Hungary. 
 
 The same, deep red, mingled with greenish 
 
 * Kirwan Geol. Es&. 180. 
 
DOMAIN II. SILICEOUS. 
 
 transparent opal, from Upper Hungary. Born 
 i. 213, 
 
 The same, of a clear blue, from Telkobanya in 
 Upper Hungary. 
 
 Green, from Meissen in Saxony. 
 
 Green pitch-stone, with adherent sand-stone, 
 from Arran. 
 
 The stalactitic kinds, and the petrified wood 
 from Hungary, cannot be said to constitute rocks. 
 
 STRUCTURE II. LAMINAR. 
 
 Laminar pitch-stone, in thin horizontal layers, 
 alternately white and violet, from Telkobanya. 
 
 A laminar kind was also discovered by Mr. 
 Jameson in the island of Arran. 
 
 MODE XIII. SILICEOUS INTRITE. 
 
 These rocks present crystals of felspar, some- 
 times quartz, or calcareous spar, in a siliceous 
 ground or base. The most remarkable kinds 
 are those called keralite or hornstein porphyry, 
 and pitch-stone porphyry. They are vaguely 
 classed under the general name porphyry by 
 German the German theorists, while the crystals are so 
 
 porphyries. 
 
 unimportant, that in geology they should be 
 
MODE X1IT. SILICEOUS INTRITE. 
 
 ranked immediately after the parent rock. The 
 primitive porphyries, according to Werner, are 
 those of hornstein and felsite ; to which may be 
 added granitic porphyroid, already described 
 after granite. If a jasper porphyry be found, it 
 must also be admitted. The classical porphyries 
 are unaccountably treated with great disregard, 
 being considered as primitive grunsteins; and 
 the real red porphyry seems as unaccountably 
 omitted. Secondary porphyry includes those 
 with bases of pitch-stone and of clay. The Ger- 
 mans have never been celebrated for clear ideas; 
 and it is truly painful to observe such an utter 
 confusion of important substances in elaborate 
 systems, while the most trifling objects are elu- 
 cidated with infinite patience and assiduity. 
 
 Turpe est difficiles habere nugas, 
 Stultus et labor ineptiamm. 
 
 STRUCTURE I. KKRAL1TE PORPHYRY. 
 
 The keralite is generally reddish or greenish. 
 It is sometimes said to form mountains in Siberia 
 and other countries. 
 
222 DOMAIN n. SILICEOUS. 
 
 STRUCTURE II. FELSITE PORPHYRY, 
 
 Saussure mentions a porphyry with a base of 
 earthy felspar. What is called klingstein por- 
 phyry, or porphyry slate, by Werner, is the most 
 common and at the same time the most remark- 
 able substance in this division. It has been al- 
 ready described under the Mode Felsite, 
 
 STRUCTURE III. PITCH-STONE PORPHYRY. 
 
 This has been chiefly observed in Auvergne, 
 where the base is generally a dark or bottle-green 
 pitch-stone, with lighter crystals of felspar. It 
 also occurs in the island of Arran. 
 
 In those parts of Auvergne which are truly 
 volcanic (a position to which the most rigid dis- 
 ciples of Werner, who have visited that region, 
 such as Buch and Daubuisson, among others, 
 have been converted), pitch-stone is often found 
 decomposed, and partly reduced to a brownish 
 mass, resembling ochre of iron, and probably 
 arising from the five parts of iron which it con- 
 tains. This substance will be more minutely de- 
 scribed in the division of Decomposed Rocks. 
 
DOMAIN II. SILICEOUS. 223 
 
 MODE XIV. SILICEOUS GLUTEN1TE. 
 
 This division will comprehend many import- Description, 
 ant substances of various structures, from the 
 celebrated Egyptian bricia, containing large 
 pebbles of jasper, granite, and porphyry, to the 
 siliceous sand-stone of Stonehenge. The glu- Origin, 
 tenites are of various formations ; and the pud- 
 ding-stone of England would rather seem, as 
 already mentioned, to be an original rock, the 
 pebbles or rather kernels having no appearance 
 of having been rolled in water. Patrin* has 
 expressed the same idea concerning those pud- Pudditig : stone 
 ding-stones which so much embarrassed Saus- 
 sure, as he found their beds in a vertical posi- 
 tion, while he argues that they could only have 
 been formed on a horizontal level. This curious 
 question might, as would seem, be easily decided 
 by examining if the kernels have been rolled, or 
 if, on the contrary, they retain their uniform 
 concentric tints, observable in the pudding-stone 
 of England, and well represented in the speci- 
 men which Patrin has engraved. But the same 
 Idea had arisen to me before I had seen Patrin's 
 
 * i. 164. 
 
DOMAIN II. SILICEOUS. 
 
 ingenious system of mineralogy. In like man- 
 ner rocks now universally admitted to consist of 
 granular quartz, or that substance crystallised 
 in the form of sand, were formerly supposed to 
 consist of sand agglutinated. Several primitive 
 rocks contain glands of the same substance, and 
 that great observer, Saussure, has called them 
 Glandulites, an useful denomination, when the 
 glands are of the same substance with the rock ; 
 while Amygdalites are those rocks which con- 
 tain kernels of quite a different nature. He 
 observes, that in such a rock a central point of 
 crystallisation may attract the circumjacent 
 matter into a round or oval form, perfectly de- 
 fined and distinct; while other parts of the sub- 
 stance, having no point of attraction, may co- 
 alesce into a mass. The agency of iron may 
 also be suspected, that metal, as appears from 
 its ores, often occurring in detached round and 
 oval forms of many sizes, and even a small pro- 
 portion having a great power*. 
 
 On the other hand, many kinds of pudding- 
 stone consist merely of rounded pebbles. Saus- 
 sure describes the Rigiberg, near the lake of 
 Lucerne, a mountain not less than 5800 feet in 
 
 * Buffon had on his estate a large and important mine, in which 
 the iron ore was solely in the form of peas. 
 
MODE XIV. SILICEOUS GLUTENITE. 
 
 height above the sea, and said to be eight leagues 
 in circumference, which consists entirely of roll- 
 ed pebbles, and among them some of pudding- 
 stone, probably original, disposed in regular 
 layers, and imbedded in a calcareous cement. 
 The pudding rocks around the great lake Baikal, 
 in the centre of Asia, present the same phe- 
 nomenon ; but it has not been observed whether 
 the fragments be of an original or derivative 
 rock. The derivative are supposed by theorists 
 to have proceeded from vast currents, flowing 
 from the primitive mountains, as on the dimi- 
 nution of the primitive waters these mountains 
 first appeared in the shape of islands, while the 
 remaining parts of continents required many 
 ages before they emerged from the ocean. It is 
 remarkable that this corresponds with the most 
 ancient ideas ; for the Argonauts are represented 
 as sailing from the Euxine Sea to the British 
 Ocean ; and Cesar describes Britain as an island 
 shared between land and water, the rivers being, 
 as in most countries newly inhabited, of enor- 
 mous size. 
 
 The siliceous sand- stones form another im- Sand-stones. 
 portant division of this mode. They may some- 
 times, as already mentioned, be confounded with 
 granular quartz, which must be regarded as a 
 primary crystallisation. The sand, which has 
 
 VOL. L, Q, 
 
226* DOMAIN II. SILICEOUS-. 
 
 also been found in micaceous schistus, and at a 
 vast depth in many mines, may be well regarded 
 as belonging to this formation ; for it is well 
 known, that if the crystallisation be much dis- 
 turbed, the substance will descend in small irre- 
 gular particles. 
 
 Siliceous sand-stones are far more uncommon 
 than the calcareous or argillaceous. The limits 
 of the chalk country in England are singularly 
 marked by large masses of siliceous sand-stone, 
 irregularly dispersed. Those of Stonehenge af- 
 ford remarkable examples of the size and nature 
 of those fragments, but the original rock has not 
 been discovered. Trap or basaltin often reposes 
 on siliceous sand-stone. 
 
 STRUCTURE I. LARGELY GRANULATED. 
 
 This division of course includes siliceous bricias 
 
 and pudding-stones. The most eminent and sin- 
 
 Bricia of gular of these occur in Egypt, in the celebrated 
 
 Egypt. & 
 
 universal bricia of the Valley of Cosseir, and in 
 the siliceous bricia of the same chain, in which 
 are imbedded those curious pebbles known by the 
 name of Egyptian jasper ; and which also some- 
 times contains agates. This last, from its colour * 
 .and decomposition, might perhaps be more pro- 
 perly classed among the Siderous Intrites; but 
 
MODE XIV. SILICEOUS GLUTENITE. 227 
 
 till a proper analysis be formed, it may as well 
 follow the universal bricia, to which it may be 
 regarded as a remarkable rival. Bricias, with red 
 jasper, also occur in France, Switzerland, and 
 other countries ; but the cement is friable, and 
 they seldom take a good polish. All these rocks 
 present both round and angular fragments, which 
 shows that the division into bricias and pudding- 
 stones cannot be accepted : a better division, when 
 properly ascertained, would be into original and 
 derivative glutenites. In a geological point of 
 view, the most remarkable pudding-stones, which 
 might more classically be called Kollanites, from 
 the Greek*, are those which border the chains of 
 primitive mountains, as already mentioned. The 
 English pudding-stone (for a particular account of 
 wjiich see the Anomalous Rocks) is unique ; and 
 beautiful specimens are highly valued in France, 
 and other countries. It is certainly an original 
 rock, arising from a peculiar crystallisation, being 
 composed of round and oval kernels of a red, yel- 
 low, brown, or grey tint, in a base consisting of 
 particles of the same, united by a siliceous cement. 
 A coarser kind also occurs, consisting of grey 
 pebbles in a far more abundant grey cement ; it 
 
 cement ; the more proper, as it also impliei iron, 
 often the chief agent. 
 
DOMAIN II. SILICEOUS. 
 
 seems harder than the pebbles themselves, which 
 . are apt to drop out entire, the circumference of 
 crystallisation having been as exactly denned by 
 the laws of attraction, as in the detached peas, or 
 little geods of iron, already mentioned. Patrin 
 supposes that they were formed separately, and 
 afterwards cemented by siliceous matter ; but as 
 many other crystals are easily detached from the 
 gangart, there seems to be no necessity for this 
 supposition. 
 
 Saussure, 1943, has treated the utility of the 
 Pebbles, study of pebbles. In the glens of high mountains 
 they are of the same stones with these mountains; 
 but in the plains, and the large adjoining valleys, 
 they are pf quite a different nature, and seem to 
 have been transported by some great revolution. 
 
 " It is an important observation for the theory 
 of the earth, that in the upper parts of valleys 
 surrounded with high mountains, no rolled pebbles 
 are found, which are foreign to the valley itself in 
 which they are met with ; those observed are never 
 other than spoils of the neighbouring mountains. 
 In the plains, on the contrary, and at the openings 
 of valleys which adjoin the plains, and even some 
 way up the sides of the mountains which border 
 on these plains, pebbles and blocks are found, 
 which might be said to have fallen from the hea- 
 
MODE XIV. SILICEOUS GLUTENITE. 
 
 vens, so different is their nature from every thing 
 found in the environs."* 
 
 The same able observer describes. 4 957, the Triumphal 
 
 arch. 
 
 triumphal arch of Augustus, at Aosta, as con- 
 structed of large squares of a singular kind of 
 pudding-stone, or large sand -stone, being an as- 
 semblage of fragments, mostly angular, of all sorts 
 of primitive rocks, quartzy, slaty, and micaceous, 
 the largest about the size of a hazel nut. The 
 cement he does not mention. Most of the ancient 
 edifices of Aosta and its environs are of this stone, 
 and the common people are persuaded that it is a 
 composition, as was also the first general belief 
 concerning granite; but Saussure observed the 
 rocks in the mountains on the north, above the 
 road to Yvree. 
 
 Aspect 1. Green universal bricia, from the old 
 Egyptian monuments. 
 
 The celebrated sarcophage, in the British Mu- 
 seum, is of this stone. As it chiefly consists of 
 green jasper, it may perhaps more properly be- 
 long to the Siderous Glutenites. 
 
 The same, from the Valley of Cosseir. 
 
 Aspect 2. The same, with rolled granite and 
 angular fragments of porphyry, from the same, 
 
 * Sauss. 717. 
 
230 DOMAIN II. SILICEOUS. 
 
 This is very rare, having been rejected by the an?- 
 cient artists. There are also other diversities. 
 
 Aspect 3. Egyptian kollanjte, or puddingr 
 stone, containing balls of brown jasper, and some- 
 times agates, with angular or round crystals of 
 unctuous quartz, in a brown ferruginous base, also 
 of an unctuous appearance, owing to the abund- 
 ance of that quartz which seems united with iron 
 in forming the cement, from the valley of Suez. 
 
 Aspect 4. The same, without the balls of jas- 
 per or agate, a fragment of the celebrated statue 
 of Memnon, in Upper Egypt. 
 
 Aspect 5. Jasper bricia, intermixed with other 
 stones, from Forez, in France. 
 The same, from Switzerland. 
 
 Aspect 6. Quartz bricia, consisting of frag- 
 ments of that substance joined by the same ce- 
 ment, from Smoland, in Sweden. 
 
 STRUCTURE II. SMALL-GRAINED. 
 
 Sand-stones. In the Mode of Glutenites it would be difficult, 
 as the celebrated Rome de Lisle has long ago 
 remarked, to fix a precise boundary between pud- 
 ding-stones and large-grained sand-stones. 
 
MODE XIV. SILICEOUS GLUTENITE. 
 
 Even the Egyptian kollanite above mentioned 
 might, without the balls of jasper and agate, be 
 considered as a large-grained sand-stone, singu- 
 larly formed of unctuous quartz. The large- 
 grained siliceous sand-stones are however far more 
 rare than those of a finer construction. It is not 
 unusual to find in them, as in other sand-stones, 
 nodules or veins of green earth or chlorite, a sub- 
 stance also common in sand ; and, like its parent 
 iron, more widely diffused than is commonly ima- 
 gined. 
 
 Mr. Kirwan's account of siliceous sand-stone is 
 too interesting to be omitted. 
 
 " This stone is generally reckoned among the 
 secondary; yet where no organic remains are found 
 in it, where it does not rest on any secondary 
 stone, where no secondary stone enters in its com- 
 position, I do not see why it may not be aggre- 
 gated to the primary. Sand, amongst the con- 
 vulsions occasioned by the volcanic eruptions 
 before the creation of animals, must have been 
 formed; and even independently of these, some 
 must have been deposited, during or after the 
 crystallisation of the various substances contained 
 in the elastic fluid. See 5th Sauss. 294. Mount 
 Jorat and the Coteau de Boissy, near Geneva, 
 1 Sauss. 246. 349, seem to be primeval ; so also 
 the sand-stone found in the island of Bornholm, 
 
DOMAIN II. SILICEOUS. 
 
 5 Berl. Beobacht. Also that mentioned in 2 
 Sauss. 763, which graduates into gneiss, must 
 also be primary, though it contains tumblers (cail- 
 lous route's). The sand-stone near Lischau, iij 
 the vicinity of Prague, graduates into horn-stone, 
 and even into granite. Mr. Rosier even thinks it 
 to have been originally a granite, whose felspar 
 was decomposed into clay, which then cemented 
 the quartzy grains; a most ingenious and pro- 
 bable conjecture. 1 Bergbau. 339 and 341. 
 
 " Most of the arenilitic mountains of Bohemia, 
 on both sides of the Elbe, appear to be primitive, 
 by Reuss's description. See Reuss, 96, &c. In 
 the east and north parts of Bohemia, many of 
 them are split, or form columns resembling ba- 
 salts. 2 Berg. Journ. 1792, 70. 
 
 " In Bohemia, sand-stones with an argillaceous 
 cement alternate with those whose cement is sili- 
 ceous. Reuss. In Kinneculla, the lowest stratum 
 incumbent on granite seems also to be primitive ; 
 over it the secondary strata repose, 29 Swed. 
 Abhand. C. 29- 5 Bergm. 126. 
 
 " In Brainsdorf, in Saxony, it passes into schis- 
 tose mica, and alternates with argillite. 2 Crell. 
 Beytr. 64. In Reigelsdorf it forms the funda- 
 mental rock on which semiprotolite immediately 
 lies, which is covered with other secondary strata. 
 2 Berg. Jour. 1790, 285. Near Oyben, and in 
 
MODE XIV. SILICEOUS GLUTENITE. 233 
 
 other tracts of Saxony, no petrifactions or conchy- 
 laceous impressions are found in it, though in that 
 of Perna, adjoining, they are found. Charp. 24 
 and 26 : it sometimes reposes on horn-slate. 
 Charp. 24. 
 
 " The mountain Steinthal, in the Vosges, of red 
 sand-stone, is considered, by Baron Diedrech, as 
 primeval. 2 Diedr. Gitts des Minerals, 209, 210. 
 The sand-stone mentioned in 6 Sauss. 81, which 
 alternates with primitive lime-stone, must also be 
 primitive."^ 
 
 Brongniart, in his Mineralogy, has adopted 
 rather a singular distribution of the gres, that is, 
 grit or sand-stone, and arranges it immediately 
 after quartz. He informs us, in a note, that he 
 only here describes the pure and homogeneous 
 sand-stone, composed solely of quartz ; the other 
 stones, commonly called sand-stones, being placed 
 among the rocks, where they will be described 
 under the name of psammites. The stone which 
 he defines is composed of very small grains of 
 quartz, " agglutinated by an invisible cement." 
 It has therefore the hardness and infusibility of 
 quartz in its grains; but its texture changes the 
 aspect of its fracture, This fracture, always gra- 
 nular, sometimes scaly and even shining, without 
 
 * Geol. Ess. 208. 
 
DOMAIN II. SILICEOUS. 
 
 ceasing to be granular, is sometimes level, some- 
 times conchoidal. When this grit is solid, it 
 strikes fire with steel ; when friable, its hardness 
 can only be judged by the ease with which it 
 scratches steel, and the hardest glass ; but it does 
 not scratch beryl. These characters suffice to 
 distinguish it from dolomite, granular sulphate of 
 barytes, emery, and some horn-stones, the only 
 substances to which it bears some resemblance. 
 
 He then enumerates several varieties: as, 1. 
 the grs lustrt of Haiiy, which betrays its granular 
 texture by its translucency. It forms beds at 
 Montmorency, near Paris, and arrects near Cher- 
 bourg. The very ingenious Gillet discovered that, 
 under a violent blow of the hammer, a regular 
 pyramid or wide cone is often extricated. 2. The 
 white sand-stone found to the south of Paris, and 
 often used for grindstones ; while that of Fontaine- 
 bleau, which is in Very thick horizontal beds, 
 serves to pave the streets of Paris. It is some- 
 times mixed with lime, which makes it effervesce ; 
 but this alteration is more rare than is commonly 
 conceived, and is only observed in the quarries 
 called Belle Croix and Nemours, where are also 
 found the curious crystals in which the quartzose 
 saiid assumes the calcareous form. 3. Ribbon- 
 grit, so called because various colours are dis- 
 played in straight lines or in zigzag : it is com- 
 
MODE XIV. SILICEOUS GLUTENITE. 
 
 mon in Thuringia and in Magdeburg. 4. Red 
 grit, which is of a coarse grain, and the particles 
 united by iron. This is the de <dlaver of the Ger- 
 mans, which it is ridiculous to class here, as it 
 totally differs from his introductory definition. 
 5. Flexible grit of Brazil. 6. Filtering-stone, full 
 of numerous and irregular pores, but seemingly 
 composed of quartz only. It is found in Saxony, 
 Bohemia, New Spain, and the Canaries : it is also 
 found in Spain, in Guipuscoa, where they make 
 statues with hollow heads, so that water being 
 poured it passes through the eyes, and the figures 
 seem to weep. 
 
 Such, he says, are the principal varieties afforded 
 by grit or sand-stone, considered as homogenous, 
 and not as a mingled rock; and he adds some 
 examples of sand-stones originally crystallised 
 with that texture : but when he includes the red 
 ferruginous sand-stone, he forgets that it some- 
 times contains fragments of porphyry and other 
 rocks ; and parts of the remainder of the article 
 refer to argillaceous and even calcareous sand- 
 stone. This stone therefore, which he places be- 
 tween quartz and flint, ought to have been classed 
 with the former under the usual denomination of 
 granular quartz. 
 
 Mr. Jameson has observed*, that there is a 
 
 * Geog. p. 39. 
 
DOMAIN II. SILICEOUS. 
 
 sand-stone cemented by quartz; so that a chemi- 
 cal and mechanical formation may occur in the 
 same rock. He mentions, in another work*, that 
 there is a vein at Lauterberg, in the Hartz, nine 
 fathoms wide, filled with quartz in the state of 
 sand. Pepits of copper are intermixed, and the 
 miners only use picks. It is crystallised, and not 
 the product of decomposition ; if permeated by a 
 siliceous juice, it would have been sand-stone. 
 Fine examples of siliceous sand-stone may be 
 found in Salisbury Craigs, near Edinburgh. 
 
 Aspect 1. Coarse siliceous sand-stone, from 
 Sweden, &c. 
 
 Aspect 2. Fine, from Stonehenge, &c. 
 
 The same, from Salisbury Craigs, near Edin- 
 burgh. 
 
 Elastic siliceous sand-stone, sometimes called 
 elastic quartz, from Brazil. 
 
 Siliceous sand-stone, like most other rocks, is 
 also found schistose and laminated. 
 
 Add the following varieties, from Saussure : 
 
 A remarkable sand-stone, composed of very 
 small grains of white quartz and felspar, with 
 little specks of greenish mica, which absorbs water 
 
 * Dumfriesshire, from Voigt, 
 
MODE XIV. SILICEOU3 GLUTENITE. 237 
 
 with avidity, becoming greenish and translucent, 
 so as to resemble a felsite or jad. 1242. 
 
 A sand-stone of a violet colour, common be- 
 tween Antibes and Frejus. It contains bits of 
 porphyry, and fragments of other sand-stones. 
 1462. 
 
 Siliceous sand-stone, which resembles gneiss, 
 and alternates with lime-stone and slate. 763. 
 
 Beds of a beautiful sand-stone, composed of 
 adherent grains of quartz. 1370. 
 
 A green sand-stone, of little fragments of quartz, 
 in a cement of felsite. 1539. 
 
 Sand is not only the produce of crystallisation, 
 but may even be produced artificially by an ope- 
 ration of that kind. 1375. 
 
 In 1751, a mountain between Sallenche and 
 Servoz fell down, with such a thick and horrible 
 dust, diffused to the distance of five leagues, that 
 people thought the end of the world was arrived. 
 It was undermined by a lake ; and vast masses of 
 stone fell down day and night with a noise like 
 thunder. Among the ruins of this mountain Saus- 
 sure found the following singular sand-stone : 
 
 " Fragments of a kind of greenish sand-stone, 
 externally spotted, very hard, and of a very fine 
 grain*. 
 
 * The bricia of Rosenberg, which fell in 1806, somewhat re- 
 
DOMAIN n. SILICEOUS. 
 
 " This sand-stone effervesces with aquafortis 5 
 very weakly; but the effervescence may be in- 
 creased, if the acid in which it is put is heated ; 
 but which does not deprive it either of its co- 
 herence or its hardness, for it strikes fire, even 
 after this proof. The grains of fine sand and mi- 
 ca, of which this sand-stone is composed, must 
 then be united by a quartzy or argillaceous glu- 
 ten, and the calcareous particles which produce 
 the slight effervescence that was observed, be in- 
 filtrated, and deposed as a foreign body in its ex- 
 ternal pores. 
 
 " I have seen in Italy antique works, which 
 were said to be basalt, but which appeared to me 
 of a kind of rock very similar to this, and conse- 
 quently very different from real volcanic basalts. 
 A statue of a child, that is shown in the gallery 
 of Florence under the name of Britannicus, and 
 which is said to be of basalt, is most likely of this 
 same kind of rock. I have had a piece of this 
 sand-stone worked ; and the kind of polish which 
 it has taken, perfectly resembles that of this sta- 
 tue."* 
 
 sembles the green bricia of Egypt, as I am informed by an ingenious 
 French traveller. 
 * Sauss. 493. 
 
DOMAIN III. 
 
 ARGILLACEOUS. 
 
 ARGIL. 
 
 J-HIS earth is obtained in the state of 
 greatest purity from alum, which is a mix- 
 ture of argil and sulphuric acid. If it con- 
 tain oxyd of iron, as is frequently the case, 
 it emits a particular smell, when breathed 
 upon, well known by the name of an 
 earthy smell. 
 
240 DOMAIN III. ARGILLACEOUS. 
 
 With heat it loses its water, and dimi- 
 nishes in bulk ; but a very violent heat 
 converts it into a white amel. When com- 
 bined with lime it easily enters into fusion. 
 
 Argil, also called Alumina by recent 
 chemists, is of great utility, as forming the 
 basis of many manufactures, such as brick, 
 porcelain, and earthenware. It constitutes 
 98 parts in the 100 of corindon; under 
 which division are now classed the most 
 perfect of the precious stones, after the 
 diamond, such as the sapphire, ruby, and 
 oriental topaz. It is hence not only one 
 of the most noble, but one of the most 
 useful of the earths ; loam or fertile soil 
 being a mixture of about 30 parts argil 
 with 70 of fine sand ; while mould chiefly 
 consists of animal and vegetable remains. 
 
 In the primitive rocks argil is an im- 
 portant feature, forming about a fifth part 
 of felspar, and a third of mica. The most 
 ancient slates abound in argil. It is often 
 so homogeneous that it cannot be regarded 
 as the waste of former mountains, but a 
 pure deposit of primeval waters. In the 
 
DOMAIN III. ARGILLACEOUS. 241 
 
 primitive schisti however there is still a 
 great reponderance of sand ; and the 
 glossy appearance may sometimes proceed 
 from decomposed mica. 
 
 The argillaceous rocks are mostly of a 
 simple and uniform appearance, and do 
 not admit the numerous modifications of 
 some other substances. This earth is chiefly 
 eminent in gemmology, where it consti- 
 tutes some of the most beautiful varieties. 
 The argillaceous rocks are never crystal- 
 lised, and present but small splendour in 
 their appearance*; hence they are very 
 seldom used in the ornamental arts, and 
 are chiefly important in a geological point 
 of view, where they often rank among the 
 most important primitive substances. Yet 
 even in this light they have not been 
 treated with the attention and minute in- 
 vestigation which have been bestowed upon 
 the Siliceous and Calcareous Divisions. 
 
 The essential part of the argillaceous 
 
 * Brongniart, i. 512, informs us, that as the argils never crystal- 
 lise, they afford no species. A further proof that this term is foreign 
 to mineralogy. 
 
 VOL. I. R 
 
DOMAIN HI. ARGILLACEOUS. 
 
 rocks being alum, it seems the most na- 
 tural progress to begin with those sub- 
 stances which chiefly supply commerce 
 with that earth. 
 
 MODE I. ALUM ROCK. 
 
 Of this there are two very different structures; 
 the alum rock of Tolfa, which yields what is 
 called the Roman alum, and the common alumi- 
 nous slate. 
 
 Alum of It has been said by some that the rock alum 
 of the middle ages derived its name from a town 
 in Syria, called Roch or Roque, Rocca ; but a 
 pilgrim having observed the same kind of rocks 
 near Civita Vecchia, the Pope founded the ce- 
 lebrated manufactory which supplied Europe 
 for some time*. The description of the latter 
 has been given by several mineralogic authors 
 under the class of salts ; but it may be interest- 
 ing to present the accurate account of Ferber, 
 who mentions, that the rocks which yield the 
 Roman alum constitute white, high, and argil- 
 laceous hills, of a compact structure, and with 
 
 * Wall. ii. p. 43. Alum is classed among the salts by chemical 
 writers, and is called sulphate of argil. 
 
MODE I. ALUM ROCK. 243 
 
 scarcely any visible horizontal beds ; but there 
 are some fissures filled with quartz, yielding 
 what are called Tolfa diamonds*. He after- 
 wards proceeds: 
 
 " The alum hills are very high, shining, white Toifa. 
 rocks, separated by a long valley, and large ex- 
 cavations, which are made in the following man- 
 ner. The workmen descend by ropes to the 
 steep rocks; thus suspended, they bore blasting- 
 holes, fill them with cartridges, free the rocks 
 which by former blastings are loosened, and 
 then are pulled up again. The firing of the 
 powder is done by dry branches and leaves, 
 which experience has taught them to throw 
 from on high to any place below. 
 
 " The alum rock is whitish grey, or chalk- 
 white ; extremely compact, and remarkably 
 hard. Scraped with a knife it yields an argil- 
 laceous powder, which does not ferment with 
 any acid, as it is penetrated by the vitriolic 
 acid, and composed of an argillaceous substance. 
 There are some bluish grey shivery pieces, which 
 are rejected as unfit, and probably are the re- 
 mains of the natural argillaceous stone, before it 
 was sufficiently imbibed and whitened by the 
 vitriolic acid. In some cracks appears a chalk- 
 
 * Italy, 206. 
 
J30MAIN III. ARGlLLACEpUS. 
 
 white ductile clay. Some pieces are bluish 
 grey, with white spots, produced hy the acid. 
 They much resemble the half-dissolved black 
 lava in Solfaterra t with white, garnet-like, 
 schorls ; with this difference, that in Solfaterra 
 the subterraneous acid worked upon lava, and 
 here upon an argillaceous bluish stone. The 
 acid seems in this place likewise to be produced 
 by subterraneous steams, which, penetrating the 
 argillaceous stones, changed them into alum 
 ore. I could not ascertain whether there be 
 near Tolfa ancient volcanoes ^ but I saw lava- 
 fragments in the wall under the boiling-pans, 
 and therefore they cannot be far distant. 
 
 " By all this it appears that the aluminous 
 rock at Tolfa is an indurated clay, having im- 
 bibed and been whitened by a vitriolic acid, and 
 contains some few calcareous particles, which, 
 in the alum manufactories, precipitate in the 
 wooden rills or troughs, under the form of sele- 
 nites. It is a compact and sound rock, neither 
 stratified nor shivery and slaty. Some nearly 
 perpendicular white-grey quartz veins, three or 
 four inches wide, cross it from top to bottom ; 
 and in some places appears in the midst of the 
 white rock a red mixture, as it were, of a colco- 
 thar vitrioli, or crocus martis, or spotted pieces, 
 which resemble red and white marbled soap. 
 
MODE I. ALUM ROCK. 245 
 
 " The blasted stones are calcined in furnaces, 
 which have an inverted conical form. They are 
 in the open fields close together, surrounded and 
 separated by a covering of turf and mould. The 
 upper diameter is about eight feet. They are 
 filled at the bottom with wood, and then heaped 
 with alum-stone, which appears above the fur- 
 naces as an accumulated cone, nine or ten feet 
 high, which is nearly answering to the 'epth of 
 the furnace. Then fire is set to the wood by a 
 square vent near the bottom, and the whole is 
 burnt down in about three hours' time ; which 
 is, as they told me, the requisite time for burn- 
 ing : after which the heated stones are carried 
 to the boiling-house, distant about one Italian 
 mile from the quarries. Here they are put into 
 large pits, or square wooden reservoirs, half sunk 
 into the ground; where they are steeped in a 
 convenient quantity of water, which, after suffi- 
 cient dissolution of the alum, is by troughs con- 
 veyed into the alum- house, and in large square 
 wooden settlers, that the dregs may settle at the 
 bottom. This done, the clear lixivium is poured 
 into brass pans, and, after sufficient boiling, con- 
 veyed into wooden coolers, on whose sides the 
 alum crystallises white and reddish. Before the 
 inspissated brine be conveyed into the cooler, 
 they stop it for some time in the troughs, in 
 
DOMAIN III. ARGILLACEOUS. 
 
 order to facilitate the precipitation of a reddish 
 selenite; and in the boiling they mix in the 
 liquor some lime and urine*. 
 
 " The supports of the pans are made of a grey 
 lava, with large white crystalline schorl-prisms, 
 whose quantity exceeds the mass of the ierru- 
 minating lava. It is found, as they told rne, in 
 large loose pieces, at nine or ten miles' distance 
 from Tolfa ; and it resembles much the lava of 
 a volcanic hill called St. Fiora, in Tuscany, 
 which I have seen, and shall describe in my fol- 
 lowing letters. 
 
 " The Tolfa alum-mines are said to have been 
 discovered in former times by a man, who, hav- 
 ing been long time a slave in Turkey, and worked 
 there in some alum works, guessed by the ilex 
 aquifolivm, common about Tolfa, that there 
 must be alum in the neighbourhood. But this 
 shrub is found in many places where no alum is 
 discovered." 
 
 It is evident from this account that the alum 
 rocks of Tolfa are very different from aluminous 
 slate, which shall be afterwards described. 
 
 * " If this be the case, the selenite is in no respect a substantial 
 part of the Tolfa alum -stone, as the author seems inclined to sup- 
 pose." Raspe the translator, whose language is far from pure. 
 
MODE I. ALUM ROCK. 247 
 
 STRUCTURE I. MASSIVE ALUM ROCK. 
 
 Texture, granular; on a large scale somewhat Characters, 
 stratified. 
 
 Hardness, gypsic. Fracture, earthy or uneven. 
 Fragments, amorphous, not sharp. 
 
 Weight, carbon ose. 
 
 Lustre, dull. Opake. 
 
 Colour, greyish white, greyish yellow, or yel- 
 lowish white. Bergman found it to contain about 
 43 of sulphur and other volatile matter; 35 argil ; 
 22 silex ; and some iron. 
 
 Mr. Kirwan says, that veins of this kind have 
 been discovered in Bretagne; but when he sup- 
 poses that the Roman alum also runs in veins, he 
 contradicts the ample account of Ferber, no in- 
 accurate observer, who formally and repeatedly 
 informs us that it is extracted from a rock consti- 
 tuting hills, and containing veins of quartz *. 
 
 STRUCTURE II. ALUMINOUS SLATE. 
 
 This substance abounds in many countries, characters, 
 Werner divides it into the common and the 
 glossy. 
 
 * The name Roman alum is now also given to the finest, 
 wherever fabricated. 
 
248 DOMAIN III. ARGILLACEOUS. 
 
 Texture, schistose. 
 
 Hardness, gypsic. Fracture, sometimes straight, 
 sometimes waved. Fragments, laminar. 
 
 Weight, from carbonose to granitose. 
 
 Lustre, glimmering ; the glossy kind glistening. 
 Opake. 
 
 Colour, greyish or bluish black. It is the black 
 slate celebrated by the vulgar for its medical pro- 
 perties. 
 
 Aspect 1. Common. This is generally used in 
 the British manufactories of alum. The finest 
 specimens are from an old coal-mine near Glas- 
 gow, in Scotland. 
 
 Alum slate, from the vicinity of Glasgow. 
 
 The same, with some small appearances of the 
 alum. 
 
 The same, more expanded or decomposed, with 
 beautiful fibres of alum, like amianthus. 
 
 The bituminous shale of Kirwan*, though he 
 ranks it with alum slate, seems to belong to a dif- 
 ferent mode. Pyrites sometimes decompose to 
 alum, vitriolic acid being formed by the oxydised 
 sulphur, which, by exposure to air and moisture, 
 slowly re-acts on the argil, and forms alum. 
 
 w 
 
 * II. 19. 
 
"MODE II. CLAY SLATE. 249 
 
 Aspect 2. Glossy. This, as already mention- 
 ed, has rather a metallic appearance, and is some- 
 times tarnished like peacock coal. In the north 
 of France it is sometimes found singularly hard 
 and compact. 
 
 Aspect 3. Alum earth. This is found com- 
 pact, and of a brownish black colour. 
 
 MODE II. CLAY SLATE. 
 
 This must not be confounded with the argil- Distinction* 
 laceous schistus of Kirwan, which is here called 
 slate, and assigned to the Siderous Domain ; 
 while clay slate is the schistose clay of Kirwan, 
 which he also calls shale, and which is often 
 found over coal, bearing vegetable impressions. 
 
 The argillaceous schistus, or argillite, of Kir- 
 wan, is the thonrchieffer of Werner ; while, by 
 too nice a distinction, his schieffertho?i, the slate 
 clay of Kirwan, is our clay slate. Brochant 
 terms it argile schisteuse. It is less hard and 
 weighty than siderous slate, adheres to the 
 tongue, and softens in water. But all their de- 
 scriptions chiefly refer to that kind which is 
 found in coal-mines ; while the most important 
 division is that which forms entire mountains, as 
 
50 DOMAIN III. ARGILLACEOUS. 
 
 among the Andes in South America, and in 
 many other metallic regions. This is in general 
 very far removed from siderous slate, which is 
 commonly quarried as valuable in architecture; 
 being less ferruginous, and far more coarsely 
 schistose, so as sometimes to be even confounded 
 with grauwack. The necessity of new denomi- 
 nations in mineralogy is also^apparent from this 
 example; for while we are told by Mr. Kirwan 
 that the Andes chiefly consist of primeval blue 
 argillite, one would expect an universal reposi- 
 tory of slates for architecture; while in fact none 
 such appear, and the substance is a coarse clay 
 slate, slightly impregnated with iron. In like 
 manner Mr. Jameson must mean the present 
 substance when he gives us the following in- 
 formation. 
 
 " Clay slate is one of the most metalliferous 
 of the primitive rocks. It contains many of the 
 venigenous formations that occur in the preced- 
 ing primitive rocks, as tin, lead, cobalt, and 
 silver. Very considerable metalliferous beds also 
 frequently occur, and these contain copper py- 
 rites, red copper ore, copper green, copper 
 azure, malachite, iron pyrites, magnetic pyrites, 
 glance cobalt, grey cobalt ore, arsenic pyrites, 
 blend and lead glance. Gold also occurs in this 
 formation, and it is said also cinnabar. 
 
MOI>E II. CLAY SLATE. 
 
 " It is a very widely-extended rock. In this 
 country it skirts the Highlands, from Lochlo- 
 mond, by Callender, Comrie, and Dunkeld ; in 
 the whole of that extensive district resting on, 
 and gradually passing into, mica slate : the same 
 appearances are to be observed in many other 
 quarters in Scotland. On the Continent of 
 Europe it has been traced through a great extent 
 of country : thus it occurs in Saxony, Bohemia, 
 Silesia, Franconia, Bavaria, the Alps of Swis- 
 serland, Austria, Hungary, and many other 
 parts in Europe. It occurs also in considerable 
 quantity in North America, as Pennsylvania ; 
 also in immense quantity in South America: 
 thus it is said that nearly the whole country 
 between Potosi and Lima is composed of it."* 
 
 It is self-evident that a wide distinction should 
 be made between this important and universally 
 diffused substance, and the siderous slate which 
 is used in architecture. 
 
 In his mineralogy, Mr. Kir wan seems to have 
 blended the primary and secondary argillaceous 
 schistus, when he mentions that it sometimes 
 bears impressions of vegetables and shells f; but 
 in his geological essays, which are valuable as 
 
 * Geognosy, 125. 
 
 f In the vale of Chamouni it is found impressed with am- 
 
 monites. 
 
252 
 
 DOMAIN III. ARGILLACEOUS. 
 
 Kirwan's 
 account. 
 
 Primitive. 
 
 they present a mass of information, compiled 
 with great labour from German authors little 
 known in this country, he has distinguished 
 them, by the divisions of his work, into primi- 
 tive and secondary rocks. His account of the 
 primitive clay slate is as follows: 
 
 " It forms whole mountains, Voigt Prack. 38. 
 But more commonly only partially enters into 
 them, as in Saxony, Charp. 175. Or entire 
 strata, as at Zillerthal, in Tyrol. Its mountains 
 are of gentle ascent. 
 
 " There is no doubt of its being often primi- 
 tive, for in Saxony it frequently alternates with 
 gneiss and schistose mica. 3 Helvet. Mag. 190. 
 1 Berg. Jour. 1792. 536. And with primitive 
 lime-stone. 8 Sauss. 144. And in Hanover gra- 
 nular lime-stone is found betwixt its layers. 
 1 Berg. Jour. 1791. 306. We have also seen 
 that both granite and gneiss often rest upon it. 
 Both Karsten, 3 Helvet. Mag. and Monnet, in 
 25 Roz. 85. sufficiently establish this distinction. 
 There are two sorts of it particularly to be 
 attended to, the harder and the sefter ; the 
 harder border upon, and often pass into, sili- 
 ceous schistus, or basanite, or hornblende slate. 
 The softer border upon, or pass into, trap, or 
 wacken, or rubble stone, or rubble slate, or co- 
 ticular slate, or indurated clay, and the harder 
 
MODE II. CLAY SLATE. 253 
 
 often graduate into the softer. 3 Nev. Nord. 
 Beytr. 169. Or border upon the muriatic. genus, 
 and pass into schistose chlorite, or schistose talc, 
 or gneiss, or schistose mica. It often contains 
 quartz, both in veins and betwixt its lamina. 
 Voigt Prack. 4L More rarely felspar, schorl, 
 garnets or hornblende, and granular lime-stone. 
 Berg. KaL 205, 206. The softer sorts are re- 
 markably metalliferous. Berg. Kal. Voigt Prack. 
 40. The famous mountains of Potosi consist of 
 it chiefly. 1 Berg. Jour. 1792. 545. In Saxony 
 it is found in primitive lime-stone. 2 Berg. Jour. 
 1792, 134; and often mixed with it, as in Leske, 
 G. 328. It is so much the more siliciferous as it 
 approaches more to granitic mountains. Lasius, 
 121. It passes into rubble stone. 2 Berg. Jour. 
 1788. 493. In the argillites of the Pyrenees no 
 organic remains are to be found. Descrip. Py- 
 ren. 27- Saussure found it in the snowy regions 
 of Mont Blanc. 7 Sauss. 256."* 
 
 Of the secondary argillite, or clay slate, Mr. 
 Kirwan gives the following description : 
 
 " There can be no doubt but argillite is fre- Secondary, 
 quently of secondary origin; Ferber acknow- 
 ledges it to be partly primeval, and partly se- 
 condary. 4 N. Act. Petropol. 289. Gruner 
 
 * Geol. Es3. 183. 
 
254 DOMAIN III. ARGILLACEOUS. 
 
 found ammonites in the argillite near Meyrin- 
 gen, in Swisserland. 3 Helv. Mag. 191. In a 
 specimen from Hessia, mytilites occur: see 
 Leske, G. 339. Voigt found a lime-stone, with 
 petrifactions, between strata of argillite. 1 Mi- 
 neral. Abhandl. 86, 87, 88. It often contains 
 piscine remains betwixt its lamina?. Lasius, 105. 
 Saussure found argillitic strata intermixed with 
 black marble. 1 Sauss. 401. In the Hartz, im- 
 pressions of reeds, rushes, and pectinites, are 
 found on it where it adjoins to rubble stone. 
 Lasius, 103. 105. Sometimes it hardens, and 
 grows more siliceous, from the bottom upwards. 
 Lasius, 105. Sometimes it is harder at greater 
 than lesser depths. Idem, 102. In the Hartz it 
 alternates with, and sometimes is intimately 
 mixed with, rubble stone. Lasius, 138. It also 
 passes into sand-stone. Idem, 105. At Kinne- 
 culla it alternates with aluminous slate and 
 marlite. 29 Schwed. Abhandl. 26."* 
 
 In the account of siderous slate it has been 
 observed that it contains from 10 to 20 of iron. 
 Dr. Townson has given an analysis of argilla- 
 ceous schistus, or clay slate, being argil 25, 
 silex 60, magnesia 9, iron 6, and some petro- 
 leum f. The last is accidental, and he perhaps 
 
 * Geol.Ess. 241. 
 
 t Philosophy of Mineralogy, p. 57. 
 
MODE II. CLAY SLATE. 5255 
 
 means shale incumbent on coal; but from 4 to 
 8 of iron may be considered as commonly be- 
 longing to clay slate, while the siderous or com- 
 mon slate, eminently so called, contains from 10 
 to 20. 
 
 Ferber's primitive slate is argillaceous, with 
 particles of mica, and crossed by veins of quartz, 
 which more rarely happens in the siderous 
 kind ; and it often appears in undulating strata. 
 He adds, that in the Vicentine and Veronese 
 territories it is regarded as the deepest rock, any 
 subjacent granite not having been discovered. 
 It contains as usual metallic veins, which often 
 run between it and the incumbent lime-stone*. 
 Patrin has little enlarged on clay slate, though 
 a rock of the first importance; but indulges his 
 imagination, that the vast beds of clay have 
 been produced by muddy eruptions of sub- 
 marine volcanoes. 
 
 The fine stone used for sharpening razors, Hone, 
 called a hone, is commonly a clay-slate, con- 
 taining, like the others, about 60 parts of fine 
 silex. It is often of the cameo kind, or disposed 
 in layers of different colours, the upper of a 
 whitish yellow, and the under of a reddish grey; 
 
 * Italy, 37- Da Costa, p. 165, says, the black slate of Claris, in 
 Swisserland, which rises in slabs, contains impressions of plants 
 and fish ; and is of course secondary. 
 
56 DOMAIN HI. ARGILLACEOUS. 
 
 the first being of a finer grain, while the latter 
 seems to graduate into the stone used for sharp- 
 ening scythes, and which, froni the coarser 
 grains of silex, becomes an argillaceous sand- 
 stone. Patrin informs us that hones are found 
 in the mountains of Jura, and the Vosges*; and 
 the substance was found on digging a well an 
 extreme depth, at Hampstead, near London. 
 Chinese Clay slate has seldom been used for orna- 
 
 cameos. 
 
 mental purposes ; but the Chinese, a most intel- 
 ligent and ingenious people, and amounting, by 
 the most moderate computation, to about two 
 hundred and thirty millions of souls, or one- third 
 of the human race, have rivalled the ancients in 
 converting to utility and ornament numerous 
 articles of the mineral kingdom; and, among 
 the rest, this substance has not escaped their 
 attention. 
 
 " The cameo slate of the Chinese is also a 
 primitive argillaceous schistus, of a very fine 
 paste, softer than the hone, and which presents 
 three, or even four, successive layers, very thin, 
 of different colours very- neatly divided, and 
 strongly adhering to each other. 
 
 " The Chinese artists have availed themselves 
 of the disposition of this stone. They form 
 
 \ 
 
 * i. 123. 
 
MODE II. CLAY SLATE. 257 
 
 basso-relievos or cameos of it, of most exquisite 
 workmanship, and sometimes of considerable 
 size. I saw a picture made of it in the Imperial 
 Cabinet of Petersburg, more than two feet in 
 length, representing a landscape, with figures of 
 men and animals. These objects were of three 
 different colours, white, green, and red; the 
 ground, of a coffee colour, made the fourth. 
 Beautiful specimens of the Chinese cameos are 
 found in several cabinets at Paris, and especially 
 in the collection belonging to the Council of 
 Mines."* 
 
 A fine piece of the same kind appears in the 
 grand collection of M. Dedree, brother-in-law of 
 Dolomieu. Some may also exist in England; 
 but although we carry on the chief trade with 
 China, there are not so many singular Chinese 
 articles in London as in Paris. The Chinese 
 musical balls, for example, are not known in 
 London. They are used by the Mandarins 
 when inclined to sleep, the mere heat of the 
 hand producing various sounds, like those of the 
 harp of Eolus. Faujas had one dissected, when 
 it was found to consist of minute wires of steel, 
 of various sizes, disposed according to some arti- 
 ficial rules. The first Parisian artists acknow- 
 
 * Patrin Min, i. 124. 
 VOL. I. S 
 
258 DOMAIN III. ARGU.LACEO.US. 
 
 ledged their inability to produce such a singular 
 machine. 
 
 Antique. Clay slate was also occasionally used in the 
 arts by the ancients, for Wad, in his catalogue 
 of the Borgian Museum, has mentioned a frag- 
 ment of a small statue of a bluish grey slate, the 
 surface being white from decomposition. There 
 are also heads of battle-axes, of a grey clay slate, 
 veined with a deeper colour, probably from some 
 island in the South Sea. 
 
 This substance is often, singularly contorted 
 in various fantastic forms, both on a large and 
 on a small scale, 
 
 Gmelin supposes that the softer clays arise 
 from the decomposition of the harder ; and he 
 says that rock clay is sometimes used in build- 
 ing*, Dr. Buchanan, in his travels in the south 
 of Himjostan, observed a kind of clay, which, 
 when dug up and dried, becomes as solid as 
 brick, whence he has ngt improperly called it 
 tatirite. later ite. 
 
 The materials concerning clay rock and clay 
 slate are unusually scanty, not only because 
 they are seldom used in the arts, but because 
 even geologists have paid far more attention to 
 the granitic and calcareous rocks than to the 
 
 * kinn. 137- 
 
MODE II. CLAY SLATE. 259 
 
 argillaceous, which are however of vast extent 
 and great importance. 
 
 The most authentic and scientific account of Andes. 
 the construction of that vast chain of mountains 
 the Andes, is contained in the travels of Helms, 
 a German mine-master, who was appointed to 
 introduce Born's method of amalgamation into 
 the Peruvian metallurgy. He remained in that 
 country from 1789 to 1793, and in 1798 pub- 
 lished his Journal, containing his daily observa- 
 tions made on the spot. In the English trans- 
 lation, or rather abridgement, the translator, 
 unaware of their consequence, has omitted many 
 important particulars; but enough remains to 
 show the construction of this magnificent and 
 singular chain, which astonished our author by 
 such abrupt irregularities, and such various al- 
 ternations of their component parts, as he had 
 never beheld in the mountains of Hungary, 
 Saxony, or the Pyrenees. In no country, he 
 adds, does a revolution of nature appear to have 
 been so general as in South America, and the 
 traces are every where discoverable. 
 
 After further premising that he travels from 
 Buenos Ayres to Lima, across the chief region 
 of the Andes, his scattered information on this 
 important topic shall be brought before the 
 reader in one point of view. 
 
 *f During the journey to Tucuman we found 
 
260 
 
 DOMAIN III. ARGILLACEOUS. 
 
 the mountains composed of primitive granite, 
 but as we proceeded, the granite became inter- 
 mixed with argillaceous slate of various colours ; 
 that however which chiefly predominates in the 
 Cordilleras is of a bluish cast, as far at least as 
 we had an opportunity of examining them. 
 Strata of lime-stone, and large masses of ferru- 
 ginous sand-stone, are in many places super- 
 incumbent on the argillaceous slate. We like- 
 wise found on the road coal, gypsum, and rock 
 salt; the last even on the summits of the most 
 elevated ridges." 
 
 In the bed of the river Rosario he likewise 
 observed blue clay slate ; and he was surprised 
 to find the highest snow-capt mountains, within 
 nine miles of Potosi, covered with a pretty thick 
 Stratum of granitic stones, rounded by the action 
 of water; while there is a continual descent to 
 Tucuman, where the granitic ridge ends: and 
 from Tucuman to Potosi it consists of simple 
 clay slate. 
 
 " The mountain Potosi, at whose foot the 
 city is built, resembles a sugar-loaf: it is almost 
 eighteen miles in circumference, and chiefly 
 composed of a yellow very firm argillaceous 
 slate, full of veins of ferruginous quartz, in 
 which silver ore, and sometimes brittle vitreous 
 ore, are found interspersed." 
 
 On his journey from Potosi to Lima, he found 
 
MODE II. CLAY SLATK. 
 
 at Alcacado clay slate, interspersed with masses 
 of granite ; and afterwards red sand-stone on the 
 clay slate. They afterwards alternate, and the 
 slate is covered with thin moss. 
 
 The rich city of La Paz is built at the bottom 
 of the highest part of the Andes, covered with 
 everlasting snow. In a fragment of the rock, 
 being a glutenite of yellow clay and rounded 
 flints, lumps of pure gold were found, weighing 
 from two to twenty pounds. Puno, which is 
 also one of the highest parts of the Andes, pre- 
 sents mountains of fine clay slate, abounding in 
 rich ores of gold and silver. 
 
 Passing through Cuzco he arrives at Carretas. 
 " The base of argillaceous slate is covered with 
 an alluvial superstratum, which consists of marl, 
 gypsum, lime-stone, sand, a large quantity of 
 rock salt, and of fragments of porphyry, &c. 
 in which pure silver and rich silver ores* occur 
 in abundance. There are few instances in 
 Europe of such mountains so generally abound- 
 ing with the precious metals, or their ores, as in 
 this quarter of the globe. The whole ridge ap- 
 pears to be full of alluvial veins of heavy silver 
 ores, in which pieces of pure silver, solid cop- 
 per, and lead ore, occur,, intermixed with a 
 great quantity of white silver ore, and capillary 
 virgin silver. Thirty-six miles before we reach 
 
DOMAIN III. ARGILLACEOUS. 
 
 Guancavelica, behind Parcos, lie mountains of 
 weather-beaten argillaceous slate, mixed with 
 sand. The sections of these mountains consist 
 entirely of separate, more or less sharp-pointed, 
 pyramids of a flesh-coloured sand-stone. 
 
 " The ridge of mountains covered with snow, 
 over which the road to the Pacific Ocean passes, 
 consists of simple sand-stone, through which 
 metallic veins, in some places with quartz or 
 felspar, in others with steatite and schorl, &c. 
 openly appear. On the contrary, the chain of 
 mountains to the north of Guamanga and Guan- 
 cavelica is said to consist, to the extent of one 
 hundred miles, of simple lime-stone, and equally 
 abounds with metallic ores, especially in the 
 province of Tarrna." 
 
 " Behind Guancavelica the mountains gra- 
 dually become composed of less various mate- 
 rials, and at last consist only of simple sand- 
 stone, with layers of marl, lime-stone, and spar, 
 or of simple lime-stone ; they continue however 
 equally rich in gold, silver, quicksilver, rock- 
 salt, &c." 
 
 It further appears from the original work that 
 the clay slate, which chiefly composes this mag- 
 nificent chain of mountains, is of various beauti- 
 ful colours ; blue, dark red, flesh colour, grey, 
 and yellow. 
 
MODE II. CLAY SLATE. 
 
 In chemical analysis it has sometimes hap- 
 pened that the chemist has ably performed his 
 task, but has mistaken the name of the sub- 
 stance. In like manner it was here necessary 
 to identify the rock, before proceeding to its 
 description. It has before been observed that it 
 may be divided into two kinds, which at the 
 same time vary considerably in their structure, 
 namely, primitive and secondary. 
 
 STRUCTURE I. PRIMITIVE CLAY SLATE. 
 
 Texture, schistose, sometimes in thin layers, Characters. 
 but more generally they arc thick and coarse; 
 fine-grained, sometimes almost impalpable. 
 
 Hardness, marmoric, sometimes gypsic. Frac- 
 ture, slaty, sometimes approaching to earthy. 
 Fragments, amorphous, tabular, with sharp angles. 
 
 Weight, carbonose to granitose. 
 
 Lustre, sometimes dull, often silky. Opake. 
 
 The colour is most usually grey, of various 
 tints ; but it may also be found of a straw yellow, 
 and various hues of red. It sometimes presents 
 streaks of a bluish white, or is mottled with va- 
 rious illinitions. 
 
 Yellow clay slate, from Potosi. 
 Grey, from the Andes, Saxony, Scotland, and 
 other metallic countries. 
 
264 DOMAIN III. ARGILLACEOUS. 
 
 Pale blue, with cubic pyrites, from Yorkshire. 
 
 The same, with dendritic pyrites. 
 
 The same, singularly convolved, from the Alps 
 of Dauphiny, and many other regions. 
 
 Thick clay slate, intersected in all directions 
 with veins of quartz, from Scotland. 
 
 The same, with calcareous spar, from Durham. 
 
 The same, with veins of quartz containing eme- 
 ralds, from the celebrated emerald -mines at Muzo, 
 in the Viceroyalty of New Grenada. It does not 
 appear that Peru ever produced any emeralds. 
 
 Massive clay slate, or perhaps rather clay rock, 
 from "Ronneburg. 
 
 Clay slate, in rhomboidal fragments, from Dit- 
 terbach. 
 
 Thick clay slate, with a coarse-grained earthy 
 fracture, from Upper Lusatia. 
 
 Green clay slate, with calcareous spar, from 
 Shneeberg. 
 
 The same, with cinnabar, from Idra. 
 
 Clay slate, with yellow blend, from Transyl- 
 / vania. 
 
 From the Specimens of clay slate, collected on the river 
 
 Ganges. 
 
 Ganges, and its vicinity, by Colonel Hard wick, 
 on his journey to Siranagur. 
 
 Clay slate, from the rocks about Ghinouly. 
 
 The same, of a silky appearance, and seemingly 
 
MODE II. CLAY SLATE. 2(5,5 
 
 much mingled with magnesia, from the rocks near 
 Siranagur. It is of an ash grey colour, and finely 
 undulated. 
 
 Greenish micaceous clay slate, from Coadwara. 
 
 Purple clay slate, veined with dull green, from 
 -the rock of Bedeyl. 
 
 Lilac-coloured clay slate, which alternates with 
 laminated smectite, in the hills near Adwaanee. 
 The strata are inclined 45. 
 
 Brown clay slate, found in thick strata near 
 Hurdwar. 
 
 Clay slate, in thin layers of different colours, 
 from Bedeyl. 
 
 Purple clay slate, from high mountains near 
 Siranagur. 
 
 Micaceous clay slate, of a bluish grey, from 
 Ansore. 
 
 Clay slate bricia, intersected with quartz veins, 
 in a cement of clay slate tufa, from Bedeyl. 
 
 Clay slate, intersected with quartz in all direc- 
 tions, from the same. 
 
 Clay slate, of a brownish red, and various other 
 colours, from Ansore. 
 
 Brown clay slate, in bowlders, found in the bed 
 of the Alecnundra, near Siranagur*. 
 
 * These specimens were presented by Colonel Hardwick to the 
 author. 
 
66* DOMAIN III. ARGILLACEOUS. 
 
 European. To the European may be added, 
 
 Micaceous clay slate, from Mont Blanc. 
 
 Clay slate, mingled with chlorite, from Mont 
 Blanc. 
 
 Purple clay slate, with spots of quartz and 
 mica, and thin layers of talcous schistus, from the 
 same. 
 
 Soft grey clay slate, from the same. 
 
 Grey clay slate, sometimes spotted with decom- 
 posed pyrites, from the summit of Snowdon, 
 where it rests in beds nearly horizontal, on arrects 
 or uprights of schistose keralite. 
 
 A remarkable clay slate, of a yellowish brown, 
 with long streaks, so as to have the appearance of 
 oak board, with some knots of a deeper brown, 
 and others white. It is mingled with a little 
 quartz and mica. Sauss. 1482. 
 
 STRUCTURE II. SECONDARY. 
 
 This either occurs uniform, or with impressions 
 of vegetables, or sometimes of shells. 
 
 Aspect 1. Uniform. Thick slaty shale, from 
 Derbyshire. 
 
 Shale, from numerous coal-mines. 
 Variety. Bituminous shale, from the same. 
 
MODE II. CLAY SLATE. 267 
 
 Aspect 2. With impressions. Shale, with the 
 impression of the skeleton of a fish in a lighter 
 colour, from Hessia. 
 
 Shale, with the impression of an ammonite, 
 from Chamouni. 
 
 The same, with impressions of various vege- 
 tables, chiefly gigantic ferns, from various coal- 
 mines. 
 
 Variety. Bituminous shale, with various im- 
 pressions. 
 
 There are two substances often found in clay 
 slate, and considered as of a kindred nature, but 
 they never appear in the form of rocks. 1. Black .Black chalk, 
 chalk, so called because it is used in drawing, 
 and which, according to Weigleb, contains 1 1 of 
 carbon. 2. Hone, which is as proper and so- Hone, 
 norous a name as novaculite, or whet-slate. Some 
 clay slates and sand-stones form the coarser whet- 
 stones, used by cutlers. The finest hones are 
 said to be- brought from Turkey, but they are also 
 said to be found in the neighbourhood of Namur, 
 in Flanders. Brochant says that it is also found 
 in Bohemia, in Saxony (Seifensdorf, near Frey- 
 berg), in Siberia, in Stiria: lastly, at Lauenstein, 
 in the Margraviate of Bareith, where it is wrought. 
 It often seems to form the passage to indurated 
 talc, and is sometimes covered with efflorescences 
 
DOMAIN III. ARGILLACEOUS. 
 
 of sulphate of magnesia, which has led to a be- 
 lief that talc is one of its constituent parts ; as 
 Werner also suspects, from its unctuous feel, and 
 being often of a greenish tint. It not unusually 
 presents two layers ; the upper of a pale greenish 
 yellow, and the under of a blackish brown. The 
 fracture is often scaly, which is seldom observed 
 in other schistose substances ; but that of Bareuth 
 sometimes presents a slaty fracture, partly ap- 
 proaching to the conchoidal, and partly to the 
 earthy. Hone seems nearly related to a highly 
 indurated fullers' earth, and is said by some to 
 decompose into tripoli*. 
 
 * Saussure says, 15p4, that the common touch-stone is com- 
 posed of little white grains of quartz and felspar, enveloped in 
 ferruginous clay. The hard black nodules, which are found in 
 slate, likewise afford very good touch-stones. The little hard grains 
 form a kind of file, which seizes on the substance of the metal, 
 while the black gluten displays the colour. And as acids do not 
 affect the stone, the trace may easily be tried by the nitrous acid, or 
 by the aqua regia. 
 
MODE III. CLAY ROCK. 
 
 MODE III. CLAY ROCK. 
 
 Texture, of a fine earthy grain. Characters. 
 
 Hardness, marmoric, sometimes gypsic. Frac- 
 ture, generally even, sometimes flatly conchoidal. 
 If slaty, it approaches to clay slate. Fragments, 
 amorphous, rather blunt. 
 
 Weight, granitose. 
 
 Lustre, dull. Opake. 
 
 This is the thonstein of Werner, which forms 
 large rocks, and is the base of his clay por- 
 phyry, which will be described among the Ar- 
 gillaceous Intrites. 
 
 In some countries, such as the Salses of Mo- 
 dena, in the Crimea, and near Girgenti in Sicily, 
 hills and masses of indurated clay are produced 
 by a singular cause, the eruption of what are 
 called muddy volcanoes. Dolomieu has mi- 
 nutely described that of Macaluba, near Gir- Macaluba, 
 genti. A circular mountain, about 150 feet in 
 height, is terminated by a plain somewhat con* 
 vex, and about half a mile in circumference, 
 which is surmounted by a great number of trun- 
 cated cones, with little craters like funnels. 
 The soil on which they rest is a grey dry floor, 
 which covers a wide and immense gulf of mud. 
 
270 DOMAIN III. ARGILLACEOUS. 
 
 There arises every instant, from the bottom of 
 the funnels, a wet greyish clay, with a convex 
 surface. This bladder, bursting with some noise, 
 throws beyond the crater the clay, which runs 
 like lava down the sides of the little hills ; the 
 intermission between the petty explosions being 
 between two and three minutes. This hill has 
 also more important fermentations, in which it 
 affects to imitate a volcano ; little earthquakes 
 are perceivable at the distance of two or three 
 miles, and there are serious eruptions, which 
 sometimes elevate a sheaf of liquid clay to the 
 height of 200 feet ; the explosions being repeated 
 three or four times in the twenty-four hours, 
 and accompanied with a fetid sulphurous odour. 
 This singular volcanello has been described by 
 Strabo and Solinus ; and the others present the 
 same phenomena. Patrin says that the clay is 
 of a greyish blue, and that Spallanzani has found 
 in it the same elements as in basaltin. Dolo- 
 mieu has also observed that the clay hills, which 
 cover the surrounding country, are the produce 
 of those eternal ejections mentioned by Solinus*. 
 When clay rock is strongly impregnated with 
 iron it passes into jasper. The more common 
 colours are grey and red, and it is sometimes 
 
 * Dolotnieu, Lipari, 153. Patrin Min. v. 24Q. 
 
MODE III. CLAV ROCK. 271 
 
 spotted or striped. Mr. Jameson, in his Mi- 
 neralogy, has promised a more particular ac- 
 count of thonstein ; which he has not however 
 accomplished in his Geognosy, where he only 
 informs us that the Pentland hills, near Edin- 
 burgh, present examples. Dr. Babington, in 
 his catalogue, mentions clay porphyry from the 
 vicinity of Edinburgh ; but gives no examples 
 of the clay rock, which seems however to form 
 a great part of that vast chain of mountains the 
 Andes. In Chili entire mountains are com- 
 posed of brown or black clay rock. 
 
 This substance frequently occurs in coal and 
 other mines, where it receives avast variety of 
 provincial names, according to the fancy of the 
 miners. In coal-mines it is commonly a shale, 
 and alternates with beds of sand-stone, which 
 also in such circumstances receives fanciful de- 
 nominations*. 
 
 Clay rock, from Saxony. 
 
 The same, from the Andes.. 
 
 The same, from Pentland hills. 
 
 * What is called the clay-bed of the Leadhills, in Scotland, 
 varies from the softness of tough clay, to the hardness of striking 
 fire with steel ; in the language of miners, from mell and wedge to 
 Hasting : and this too at a depth from forty to fifty fathoms. 
 
 Near Lesmahago, Lanarkshire, is a lead-mine in clay slate : the 
 metal being in a vein of sulphate of barytes, five feet wide. G. L- 
 
DOMAIN III. ARGILLACEOUS. 
 
 Saussure, 1944, describes a kind of clay rock 
 found among the pebbles of the two rivers called 
 Emme, in Swisserland. This substance having 
 hitherto little engaged the attention of mineral- 
 ogists or geologists, all the accounts are very 
 imperfect, 
 porcelain Porcelain clay sometimes constitutes rocks; 
 
 clay. 
 
 but it is merely a decomposed felspar, which 
 may be found in the Domain entitled Decom- 
 posed Rocks. Potters' clay seems only to occur 
 in separate strata ; when of a greyish white, it 
 is called pipe-clay. The clay of which the 
 famous Egyptian vases have been formed for 
 many thousand years, is, according to Roziere, 
 of a marly nature, and is found near Coptos in 
 the Thebaid. It approaches to the fawn co- 
 lour, and is of a porous and light consistence. 
 Porous vases which, by evaporation, impart 
 great coolness to water, are also made in Spanish 
 America, where the ladies are even fond of eat- 
 ing the fragments*. Molina, in his interesting 
 account of Chili, has described several valuable 
 clays, of which there is one which long retains a 
 sweet smell. 
 Boies. The Lemnian, Armenian, and other boles, 
 
 * Da Costa, p. 20, says it is a bole useful in acidities, and as a 
 dentifrice. 
 
MODE IV. WACKEN. 273 
 
 formerly celebrated as absorbents, and which 
 are now supplanted by magnesia, are merely 
 fine clays, which contain a small portion of 
 magnesian earth. Hence they somewhat ap- 
 proach in their nature to the fullers' earth of 
 Berkshire, and Ryegate in Surry*. 
 
 The earth called almagra, which is used to 
 impart a red colour, and an unctuous feel, to 
 Spanish snuff, is found at Almazaran, near Car- 
 thagena, in Spain, and seems a fine ferruginous 
 clay, perhaps with a mixture of magnesia. 
 
 MODE IV. WACKEN. 
 
 Texture, sometimes compact, sometimes vesi- Characters, 
 cular. When the vesicles are filled with para- 
 sitic stones, it is called amygdalite ; but as the 
 base of the latter is more frequently a trap or 
 basaltin, it has been classed after that substance. 
 
 Hardness, marmoric, sometimes gypsic. Frac- 
 ture, commonly even, sometimes approaching 
 the flat conchoidal. Fragments, amorphous, 
 rather blunt. 
 
 Weight, granitose. 
 
 * Bergman has put Hampshire, in which he is followed by all 
 the foreign mineralogists ; but there is no fullers' earth in Hamp- 
 shire. 
 
 VOL. I. T 
 
DOMAIN III. ARGILLACEOUS. 
 
 Lustre, dull, sometimes faintly glimmering. 
 Opake. 
 
 The usual colour is grey, sometimes approach- 
 ing to black. It may also be brownish, from 
 iron ochre. Wacken sometimes contains mica, 
 but this mixture cannot be regarded as charac-* 
 teristic, as appears from the amygdalites. 
 
 Wacken is ranked by the German mineral- 
 ogists as intermediate between basalt and clay. 
 Like basalt it sometimes presents siderite, but 
 never contains augite or olivine. It is regarded 
 as secondary, because petrified wood has been 
 found in it : but such arguments are sometimes 
 fallacious, for the detritus of a primitive rock 
 may again consolidate, as in the case of granite, 
 and it is easily conceivable that it may thus en- 
 velope substances foreign to its original form- 
 ation. 
 
 Wacken is often a corn&enne, or roche de corne, 
 of the French mineralogists. The grauwack of 
 the Germans is a very different substance, which 
 will be described among the Argillaceous Glu- 
 tenites. 
 
 Wacken, from Saxony, &c 
 
MODE V. SMECTITE. 275 
 
 MODE V. SMECTITE. 
 
 This substance is commonly called fullers' 
 earth ; but as the latter word would here seem 
 rather a solecism, it may be preferable to adopt 
 the Greek denomination. 
 
 Texture, earthy, sometimes with a very fine Characters, 
 grain. 
 
 Hardness, cretic. Fracture, uneven, some- 
 times large conchoidal. Fragments, amorphous 
 and blunt. 
 
 Weight, carbonose. 
 
 Lustre, dull. Opake. 
 
 The colour has often a greenish tinge, which 
 may arise from a very small portion of mag- 
 nesia; but as this scarcely amounts to 1 in 100, 
 there is no reason for classing it among the 
 Magnesian Rocks; especially as in that from the 
 island of Cimolus, which is superior even to the cimoiite. 
 English, Klaproth could discover no magnesia, 
 the unctuous feel arising from the mere purity 
 of the clay*. In general fullers' earth would Fullers' earth, 
 rather be judged of a light brown colour. The 
 
 * Da Costa has observed that great fineness of the grain will 
 ften impart an unctuous feel. 
 
 T 2 
 
DOMAIN III. ARGILLACEOUS. 
 
 coarser sort at Ryegate, which contains crystals 
 of barytes, is of a reddish brown, and is not used 
 in commerce. 
 
 The analysis by Bergman bears that the 
 fullers' earth comes from Hampshire, a mistake 
 followed by a hundred mineralogic writers; and 
 it was probably from Reading, in Berkshire, for 
 in the vicinity of that town there are remarkable 
 quarries, which lie under beds of sea sand, 
 mingled with numerous shells of oysters. It is 
 also found near Woburn, in Bedfordshire, and 
 Ryegate, in Surry. 
 
 Da Costa informs us, that fullers' earth is dug 
 at Wavendon, near Woburn, in Bedfordshire. 
 For about six yards there are layers of reddish 
 sand, then a thin stratum of sand-stone, then 
 sand again for seven or eight yards; after which 
 fullers' earth appears for about eight feet, fol- 
 lowed by sand-stone and sand. At Ryegate 
 and Nutfield, in Surry, the strata are similar; 
 but at Detling, near Maidstone, in Kent, it un- 
 derlies a sandy loam, mixed with a great variety 
 of shells. It is prevented from being exported 
 by a special act of parliament*. 
 
 Near Reading oyster-shells are found at the 
 bottom of a high hill, a hundred feet below the 
 
 * Nat. Hist, of Fossils, 1757, 4to. p. 69. 
 
MODE V. SMECTITE. 77 
 
 surface. They lie on chalk, covered with sea 
 sand, which still retains its brackish flavour. 
 Above that is fullers' earth, nearly eleven feet in 
 depth, and then chalk, and different kinds of 
 clay ; then a common sort of sand : and so on 
 to the surface, which is gravel. 
 
 It does not effervesce with acids, nor is it dif- 
 fusible in water, in which it does not froth like 
 soap, as some have asserted. It is used in what 
 is called the fulling of broad cloth, an operation 
 which consists in extracting the grease. 
 
 Abroad, it has been found in Saxony, Alsace, 
 and Sweden, always forming beds of more or 
 less thickness. In England it commonly ap- 
 pears between beds of sand-stone. 
 
 The earth brought from Cimolus, which is 
 described by Pliny as used in medicine and in 
 bleaching, has again been discovered, by Mr. 
 Hawkins. It is mingled with small particles of 
 quartz; but this circumstance does not prove it 
 to be a decomposed granite, as an accidental 
 mixture of silex occurs in many substances. 
 
 Fullers' earth, from Reading, in Berkshire. 
 
 The same, with incumbent sea sand and 
 oyster- shells. 
 
 The same, from Ryegate, in Surry. 
 
 The same, of a coarser kind and darker co- 
 lour, with imbedded crystals of yellow barytes. 
 
78 DOMAIN III. ARGILLACEOUS. 
 
 Mr. Sowerby has a large regular crystal of this 
 kind, equal in beauty to a topaz. 
 
 Smectite, from Cimolus, one of the islands of 
 the Grecian archipelago. 
 
 MODE VI. ICONITE. 
 
 This substance is only known by the little 
 images brought from China, whence the name 
 is imposed. From its unctuous appearance it 
 was long imagined to belong to the Magnesian 
 Domain, till Klaproth's analysis assigned it to 
 the Argillaceous. It contains, silex, 62; argil, 
 24; lime, 1; water, 10; a combination which 
 nearly corresponds with the smectite of Cimo- 
 lus. The abundance of water seems, in this and 
 some other substances, to impart an unctuous 
 appearance; but the refinements in modern 
 chemistry may perhaps discover something par- 
 ticular in the composition of this water*. 
 
 The Germans denominated this substance 
 
 BiWstein. bildstem, that is, image-stone, which Klaproth 
 
 lias translated agalmatolite, while he might have 
 
 used the far shorter term here adopted. It must 
 
 * The analysis approaches that of chalcedony, which has also an 
 unctuous appearance, perhaps from the admixture of argil. 
 
MODE VI. ICONITB. 
 
 also be premised, that sometimes the red or 
 flesh-coloured stone, more rarely used for the 
 same purposes by the Chinese, really belongs to 
 the magnesian kind. 
 
 Klaproth mentions two kinds of iconite, the 
 transparent and the opake; the former unex- 
 pectedly presenting a third more argil, and only 
 half the water of the latter. 
 
 STRUCTURE I. TRANSPARENT. 
 
 Klaproth describes this sort as being of an olive 
 or asparagus green, verging through various tints 
 to a greenish blue. The interior aspect is very 
 glittering, and of a greasy lustre; the fracture 
 scaly. 
 
 STRUCTURE II. OPAKE. 
 
 This, according to Klaproth, is reddish white, 
 flesh red, and with variously-coloured veins ; the 
 fracture is less distinctly scaly ; the lustre dull, 
 opake, but somewhat translucent on the edges. 
 
 Werner has rightly added to the colours of the 
 bildstein the greenish grey, of different degrees 
 of intensity, the yellowish passing into yellowish 
 grey mingled with green, and into pale yellowish 
 brown. The greyish white seems to be one of 
 the most common tints of this substance. 
 
 IF r> o T m^sr 
 
DOMAIN III. ARGILLACEOUS. 
 
 Du Halde, in his description of China, men- 
 tions that the district of Tay-tong-fu, belonging 
 Yu-she. to Shan-si, furnishes the most beautiful Yu-she, 
 which that author, in the confused mineralogy of 
 the time, calls a kind of white jasper. He adds, 
 that it resembles agate, is transparent, and some- 
 times appears spotted. 
 
 Goez, who travelled to Tibet in 1602, in de- 
 scribing Yarkand, the capital of the kingdom of 
 Kasgar, in Little Bucharia, mentions, that a com- 
 modity, particularly acceptable in China, was a 
 kind of marble or jasper, found in Kasgar*. 
 " The king of Katay buys it at a great price ; and 
 what he leaves, the merchants sell to others at 
 exceeding great rates. Of it they make vessels, 
 ornaments for garments, and girdles, with other 
 toys, whereon they engrave leaves, flowers, and 
 other figures. The Chinese call it Tushe-\. There 
 are two kinds; one more precious, like thick 
 flints, which are found by diving in the river 
 Kotan, not far from the City Royal: the other 
 meaner sort is digged out of quarries, and sawed 
 into slabs above two ells in breadth. The hill 
 where they are dug, called Konsanghi Kasho, 
 
 * Green's Voyages, iv. 645. 
 
 f In the original Tusce, a mistake, no doubt, for Yu-she, the 
 word used by Du Halde. There seems great reason to infer, that 
 the pocula murkina of the ancients were of this substance. 
 
MODE VII. ARGILLACEOUS INTRITE. 81 
 
 or the stony mountain, is twenty stages from the 
 same city. This marble is so hard, that they 
 must soften it with fire to get it out of the quarry. 
 The king farms it every year to some merchant, 
 who carries provisions for the workmen for that 
 space of time." 
 
 This precious substance, if we judge from its 
 hardness, cannot be the present article; but is 
 probably that beautiful jad (though perhaps fu- 
 ture discoveries may impose a different name), 
 which is brought from Tibet and China in the 
 form of small basins, sword-handles, c. It some- 
 what resembles chalcedony, but is far more pond- 
 erous. The chemical analysis and proper classi- 
 fication of this singular substance remain among 
 the desiderata of mineralogy, though specimens be 
 not uncommon in various great collections. 
 
 MODE VII. ARGILLACEOUS INTRITE. 
 
 The argillaceous intrites and glutenites are of 
 prodigious extent and importance. The chief 
 intrite, commonly called clay porphyry, as con- 
 sisting of crystals of felspar in a base of clay, is 
 sometimes a principal material in vast chains of 
 mountains. The argillaceous glutenites, called 
 
DOMAIN III. ARGILLACEOUS. 
 
 grauwack, sand-stone, &c. form extensive re- 
 gions of the earth. 
 
 * 
 
 STRUCTURE I. ARGILLACEOUS INTRITE, WITH CRYSTALS 
 OF FELSPAR. 
 
 This substance forms large mountains in Lower 
 Hungary, and sometimes contains chalcedonies, 
 carnelians, amethysts, or zeolite *. According to 
 Werner it is either primary or secondary; the 
 latter containing branches and roots, and even en- 
 tire trees, petrified ; as, for example, near Chem- 
 nitz in Saxony. The primitive argillaceous por- 
 phyry has commonly a red base, but differing 
 much in hardness from genuine porphyry. 
 
 This intrite forms a considerable portion of the 
 Andes, and of the metallic mountains of New 
 Spain. The saxum metalliferum of Baron Born 
 is also a clay porphyry, but is justly classed 
 among the Decomposed Rocks. Great confusion 
 has arisen, as has already been observed, from 
 arranging the porphyries in one family ; while they 
 ought to be classed as intrites, according to their 
 various bases. 
 
 Clay porphyry, from the metallic mountains of 
 New Spain. 
 
 * Kirwan Geol. Ess, 206, 207. 
 
MODE VIII. ARGILLACEOUS GLUTENITE. 283 
 
 The same, from Lower Hungary. 
 
 The same, from Pentland hills, near Edinburgh. 
 
 The same, with petrified wood, from Saxony. 
 
 STRUCTURE II. WITH VARIOUS CRYSTALS. 
 
 Argillaceous intrites are also found with inlaid 
 crystals of quartz, calcareous spar, zeolite, and 
 other substances. 
 
 MODE VIII. ARGILLACEOUS GLUTENITE. 
 
 There is scarcely any bricia which belongs to 
 this Domain. Born indeed mentions a clay 
 bricia, consisting of fragments of his metallic 
 rock, joined by an argillaceous cement*. Frag- 
 ments of clay slate are also found united by a 
 spongy argillaceous tufa, an evident decompo- 
 sition of the substance by water. But these in- 
 stances are rare, and of little moment. 
 
 That kind of glutenite called pudding-stone 
 also falls rarely under this Domain, the cement 
 being commonly siderous or siliceous. 
 
 The argillaceous glutenites may as usual be 
 divided into the large and small grained. Even 
 the grauwack of the Germans, the most gene- 
 
 * Raab, i. 414. 
 
^84 DOMAIN III. ARGILLACEOUS. 
 
 rally diffused of this kind, may rather pretend to 
 the latter denomination, as where the pebbles 
 are large, they are commonly interspersed at 
 considerable distances. 
 
 STRUCTURE I. LARGE-GRAINED ARGILLACEOUS GLU- 
 TENITE. 
 
 inanects. The most remarkable rock of this kind is that 
 described by Saussure, who discovered it unex- 
 pectedly in a vertical situation, in the Alps of 
 Vaiorsine. In 1776, and afterwards in 1784, he 
 visited the mountain of Balme, which gives source 
 to the river Arve, and made the following curious 
 observations, which chiefly contributed to lead to 
 his system of refoulemcnts or subversions, an idea 
 which unhappily he does not explain at full length, 
 but implying that the rocks now found vertical 
 were formed in a horizontal position, and were 
 afterwards elevated by some cause operating in a 
 contrary direction from beneath or above *. 
 
 " The base of this mountain is a genuine grey 
 granite, with grains of a middling size, and of a 
 structure nothing remarkable. But above these 
 granites are found schistose rocks of quartz, mica, 
 and felspar ; an intermediate kind of rock between 
 
 * The French of the Swiss writers in general is impure, and 
 sometimes requires a particular dictionary, as they think in Swiss or 
 German. 
 
MODE VIII. ARGILLACEOUS GLUTENITE. 285 
 
 veined granite and common mica slate. Their 
 beds run from north to south, as does the valley 
 of Valorsine, and form an angle of 60 degrees 
 with the horizon, leaning to the west, against the 
 valley. These rocks are continued in the same 
 situation for more than half an hour's walk ; they 
 are lost sight of under the verdure which covers a 
 small plain, situated in the midst of woods, and 
 which is called le plan des Ceblancs. 
 
 " From thence, ascending obliquely on the south 
 side, great blocks of grey schistus, or of a violet 
 red, are found, sometimes even of a decided violet 
 colour, which contain a great quantity of foreign 
 pebbles, some angular, others rounded, and of 
 different sizes, from a grain of sand to the size of 
 the head. I was desirous of seeing these pud- 
 ding-stones in their native place. I went straight 
 up, to get to it ; but there, how was I surprised 
 to find their beds vertical ! 
 
 " This surprise will easily be conceived, when 
 it is considered that it is impossible that these 
 pudding-stones could have been formed in this 
 position. 
 
 " That particles of the greatest tenuity, sus- 
 pended in a liquid, may be agglutinated among 
 themselves, arid form vertical beds, is what we 
 easily conceive, and of which we have proof in 
 the instances of alabaster, agates, and even in 
 
86 DOMAIN III. ARGILLACEOUS. 
 
 artificial crystallisations : but that a ready-formed 
 stone, as large as the head, should stop in the 
 middle of a vertical wall, and have waited there, 
 till small particles of stone should come and sur- 
 round it, cement it, and fix it in that place, is a 
 supposition at once absurd and impossible. It 
 must then be considered as a thing demonstrated, 
 that these pudding-stones have been formed in a 
 horizontal position, or nearly so, and elevated 
 after their induration. What is the cause that 
 has elevated them? It is what, as yet, we are 
 ignorant of; but it is already one step, and that 
 an important one, to have found, among the pro- 
 digious quantity of vertical beds which are met 
 with in our Alps, some, which we are very cer- 
 tain have been formed in a horizontal position. 
 
 " Even the nature of the substance which en- 
 velopes the pebbles of these pudding-stones, ren- 
 ders this fact more curious, and more decisive. 
 For if it was a misshaped and coarse paste, it 
 might be thought that these pebbles, and the paste 
 which cements them, were thrown pell-mell into 
 some vertical crevices, where the liquid part hard- 
 ened by drying. But on the contrary, the tissue 
 of this paste is of admirable regularity and fine- 
 ness ; it is a schistus, whose elementary laminae 
 are extremely thin, mixed with mica, and perfectly 
 parallel to the planes which divide the beds of the 
 
MODE VIII. ARGILLACEOUS GLUTENlTE. 287 
 
 stone. Those beds themselves are very regular, 
 well connected, and of different thickness, from 
 half an inch to several feet. Those which are thin 
 contain few, and sometimes no foreign pebbles ; 
 and some alternations are observed of thin beds 
 without pebbles, and thick ones which contain 
 them. The colour of the base of this schistus 
 varies considerably; it is grey, greenish, most 
 often violet, or reddish ; some is also found 
 marbled with these different colours. These beds 
 are in a direction from north to south, exactly like 
 those of granitoid rocks, which are under them ; 
 but the inclination of the schistus in much greater, 
 its beds are often nearly vertical ; and when they 
 are not, they rise some degrees on the same side as 
 the rocks I have just mentioned, that is, towards 
 the west. 
 
 " The pebbles buried in this schistus are, as I 
 have said, of different sizes, from a grain of sand 
 to six or seven inches diameter ; they all belong 
 to that class of rocks which I call primitive ; yet 
 I have not observed massive granite ; only laminar 
 granite, laminar rocks, blended with quartz and 
 mica; even fragments of pure quartz, but posi- 
 tively no schistus purely argillaceous, nor any 
 lime-stone ; nothing which effervesces with aqua- 
 fortis, and even the paste which contains these 
 stones does not. Their form differs; some are 
 
88 DOMAIN in. ARGILLACEOUS. 
 
 rounded, and have evidently lost their angles by 
 friction ; others have all their angles sharp ; some 
 even have that rhomboidal form that those kind of 
 rocks so often affect. In those parts of the rock 
 where these pebbles are imbedded in great quan- 
 tities, the elements of the schistus have not had 
 room to arrange themselves, and form parallel 
 laminae ; but every where, where the stones leave 
 between them sensible intervals, the laminae re- 
 appear, and are constantly parallel, both with one 
 another and with the planes which divide the beds. 
 " The mass of these schistose pudding-stones 
 constitutes a thickness of near 100 fathoms in the 
 mountain, reckoning from east to west across the 
 beds ; and I traced it in the direction of its length, 
 for more than a league : it cannot be traced far- 
 ther, because the beds hide themselves, and are- 
 buried under the earth. 
 
 " Above these pudding-stones, to the south, 
 slate is found, of which the beds are rather less 
 inclined, and the direction a little different ; they 
 tend some degrees more to the east, like those of 
 Col de Balme, but they lean to the same side, as 
 thos,e among the beds of pudding-stones, which 
 are not quite vertical : they lie towards the west. 
 " In continuing to ascend, thin beds of sand- 
 stone are found above the slates, which have the 
 same situation and inclination with these last. 
 
MOI>E VIII. ARGILLACEOUS GLUTENITE. 39 
 
 On these sand-stones are other slates ; then thin 
 layers of bluish calcareous rocks, mixed with 
 mica; then the same stone with very little mica; 
 and then again the same in thicker beds without 
 any mixture of mica. 
 
 " Then the same succession recommences : first 
 sand-stone, mixed with mica and quartz ; on these 
 lime-stones, in thin layers, mixed with mica and 
 quartz; then the same, in thin layers, almost 
 without any mica ; and lastly the same, in thicker 
 layers, entirely exempt from mica. 
 
 " Here the vegetable earth almost entirely co- 
 vers the summits of the layers; only here and 
 there, two or three feet above the grass-plats, 
 eminences of calcareous layers, nearly vertical, 
 are perceived. These eminences, arranged in pa- 
 rallel lines, as if they had been so placed by art, 
 afford an appearance altogether singular. 
 
 " From thence to the highest limit of Col de 
 Balme, you walk entirely on summits of slate, 
 nearly vertical, which sometimes degenerate into 
 laminar sand-stone, mixed with mica; and such 
 is the nature of the peak, on which is placed the 
 high stone ; bearing on one side the arms of Sa- 
 voy, and on the other those of Valais, with the 
 date of 1738. These latter layers turn more di- 
 rectly from north to south, and approach nearer 
 to the vertical position, than the slates, which are 
 
 VOL. r. u 
 
DOMAItf HI. ARGILLACEOUS. 
 
 above the pudding-stones ; but their inclination it 
 always towards the west. 
 
 " The entire mass of this mountain, elevated 
 1181 fathoms above the sea, has then been raised 
 by the same revolution, that is, this revolution 
 has given a vertical position to the whole mass oi 
 these beds, originally formed in a horizontal one, 
 For all these layers having very nearly the same 
 position as those pudding-stones, they being im- 
 bedded in the midst of the mountain, and having 
 undoubtedly undergone this change, it is impos- 
 sible not to believe that the position of all the 
 parts of the mountain has originally been the 
 same, and that this position has experienced ths 
 same change by the same cause."* 
 
 Such is the account given by this great observer 
 of the most remarkable argillaceous glutenite 
 which has yet been discovered ; and it is worthy 
 observation, that this instance, among many 
 others, shows the error of the division, proposed 
 by some, of bricias and pudding-stones ; for here 
 both angular fragments and round pebbles are 
 found in the same mass. 
 
 A great part of the north of Scotland, and 
 almost the whole of the Orkneys, consist of an 
 . argillaceous sand-stone, with interspersed masse* 
 
 * San?*, vol. iii- 138. S^o. 
 
MODE VIII. ARGILLACEOUS GLUTENITE. 291 
 
 of bricia, consisting of granite and other primitive 
 rocks. But this bricia seems to be united by a 
 siliceous cement : if the fragments be sometimes 
 joined by the argillaceous sand-stone, it may be 
 classed under this division. 
 
 The substance called grauwack by the Germans Grauwack. 
 sometimes contains large fragments of clay slate, 
 and large pebbles of quartz ; but as its grain in 
 general is rather that of a sand-stone, it will be 
 considered under the next structure. The Ger^ 
 man name is not only barbarous in itself, but im- 
 plies grey wacken ; while wacken is a rock essen- 
 tially different. Mr. Kir wan says that it is the 
 grts-gris, or grey sand-stone, of the French, a 
 name very applicable ; and it seems also to be the 
 grison of some French topographers. The latter 
 appellation might be adopted as at once express^ 
 ive and sonorous; but as other important rocks 
 have received appellations from the illustrious 
 founders of mineralogy, the term Bergmanite may 
 perhaps be preferable. 
 
 STRUCTURE II. SMALL-GRAINED ARGILLACEOUS GLU- 
 TENITE. 
 
 The most celebrated rock of this denomination orison, or 
 
 . u Bergmanite. 
 
 is the Grison, or Bergmanite, just mentioned, 
 being composed of grains of sand, various in size, 
 sometimes even kernels of quartz; which, with 
 
 u 2 
 
DOMAIN 111. ARGILLACEOUS. 
 
 occasional bits of hard clay slate, and sometimes 
 of schistose keralite, are imbedded in an argilla- 
 ceous cement, of the nature of common grey clay 
 slate. When the particles are very fine, it as- 
 sumes the slaty structure, and forms the grauwack 
 slate of the Germans. It is the chief of Werner's 
 transitive rocks, nearly approaching to the primi- 
 tive; while at the same time it sometimes con- 
 tains shells, and other petrifactions of the se- 
 condary. 
 
 This important rock was formerly considered 
 as being almost peculiar to the Hartz, where il 
 contains the richest mines ; but as the science has 
 advanced, it has been observed in many othei 
 countries. The slaty grison, or Bergmanite, haf- 
 been confounded with a clay slate; and we arc 
 obliged to Mr. Jameson for the following dis- 
 tinctions : 1. It is commonly of a bluish, ash, or 
 smoke grey, and rarely presents the greenish or 
 light yellowish grey colour of primitive clay slate. 
 2. Its lustre is sometimes glimmering from specks 
 of mica, but it never shows the silky lustre of clay 
 slate. 3. It never presents siderite nor garnets. 
 4. It alternates with massive grauwack. But i? 
 not the chief distinction its aspect of a sand-stone, 
 which has led to the trivial French name of gr&s- 
 gris, and the English rubble-stone, which may 
 imply that it was formed of rubbed fragments, or 
 
MODE mi. ARGILLACEOUS GLlfTENITE. 
 
 of the rubbish of other rocks ? The fracture is 
 also different; and three specimens of various 
 fineness, which I received from Daubuisson at 
 Paris, could never be confounded with clay slate. 
 
 " This rock is uncommonly productive of me- 
 tals, not only in beds but also in veins, which 
 latter are frequently of great magnitude. Thus 
 almost the whole of the mines in the Hartz are 
 situated in greywack. These mines afford prin- 
 cipally argentiferous lead-glance, which is usually 
 accompanied with blend, fahl ore, black silver 
 ore, and copper pyrites. A more particular ex- 
 amination discloses several distinct venigenous 
 formations that traverse the mountains of the 
 Hartz. The greywack of the Saxon Erzgebirge, 
 of the Rhine at Rheinbreidenbach, Andernach, 
 &c., of Leogang in Salzburg, is rich in ores, par- 
 ticularly those of lead and copper. At Voros- 
 patak and Facebay, in Transylvania, the greywack 
 is traversed by numerous small veins of gold. 
 
 " The whole of the important lead-glance form- 
 ation of Leadhills and Wanlockhead is situated in 
 greywack. 
 
 u It was for a long time supposed that this rock 
 was peculiar to the Hartz, where it occurs in great 
 quantity : later investigations however have shown, 
 that it is widely and abundantly distributed. Be- 
 sides the Hartz, it occurs also in the Electorate 
 
294 DOMAIN III. ARGILLACEOUS. 
 
 of Saxony, on the Rhine, as at Ehrenbreitstein 
 and Oppenheim, Bohemia, Silesia, Moravia, Salz- 
 burg, Switzerland, Pyrenees, Transylvania, Tus- 
 cany, France, and Portugal ; nearly all the moun- 
 tains in Scotland, that lie to the north of the Frith 
 of Forth, are principally composed of this rock : 
 and many, if not the whole, of the mountains in 
 Cumberland appear to be of the same nature."* 
 Argillaceous Another remarkable rock, belonging to this di- 
 
 sand-stone. 
 
 vision, is the argillaceous sand-stone, which com- 
 poses the Orkneys, and part of the north of Scot- 
 land. It is commonly of a brown colour, and 
 more or less indurated by iron, whence it some- 
 times decomposes in fantastic forms. The south- 
 eastern part of the Mainland of Shetland also con- 
 sists of this sand-stone, which has unexpectedly 
 been found to be metalliferous. A copper mine 
 was opened near Sandlodge, the upper rock being 
 sand-stone, while, at the depth of 150 feet, was 
 found a rock of keralite, traversed by many veins 
 of brown quartz. The copper was imbedded in 
 an iron ore, in veins between the sand-stone and 
 the keralite. " The iron ores here found are, 
 1. Dark-brown, fibrous, and mamellated hema- 
 tites. 2. Columnar bog-iron ore. 3. Micaceous 
 
 * Jameson, Geognosy 151. In his Dumfries, p. Q2, he says 
 the craigs near that town consist of fragments of syenite and grau- 
 wack, the bricia being cemented by ferruginous clay. 
 
MODE Till. ARGILLACEOUS GLUTENITE. 
 
 iron ore. 4. Iron ochre, of a brown colour. 5. 
 Stalactitic iron ore, colour dark brown. 6. Earthy 
 matter, much charged with iron, seemingly arising 
 from the debris of other ores. The copper ores 
 are, 1. Friable and amorphous carbonate of cop- 
 per, colour rich green. 52. Beautiful carbonate of 
 an emerald green, crystallised in capillary fibres 
 of a silky lustre, diverging in radii from a centre : 
 this species is found imbedded in iron ore. 3. 
 Sulphuret of copper, disseminated through felspar 
 in some places, and in others, in great masses, in 
 iron ore. The rich carbonates were found near 
 the bottom of the mine."* 
 
 This sand-stone also often occurs in a schistose 
 form, when it is called sand-stone flag. 
 
 The Wernerians have confounded the sand- 
 stones, as they have the porphyries, while they 
 ought to be carefully distinguished according to 
 the nature of the cement. The whet-stones and Whet-stone, 
 
 c. 
 
 filtering-stones are often argillaceous glutenites, 
 as is the important division Cos of Wallerius, Lin- 
 naeus, and other writers in Latin. Some whet- 
 stones are curiously spotted, commonly with dark 
 specks on a light ground f. According to Wal- 
 
 * Dr. Trail's Mineralogy of Shetland, in Neil's Tour, p. 170. 
 
 t Da Costa, 120, &c. mentions the whet-stone of Derbyshire 
 as of a lax texture, easily pervaded by water, as most clays are. 
 The grind-stone of Gateshead, Durham, also possesses this quality. 
 
296 DOMAIN III. ARGILLACEOUS. 
 
 lerius, the filtering-stone from the Canary Islands,, 
 and New Spain, consists of angular particles of 
 quartz, united without any cement ; but the pure 
 siliceous sand-stone seems the most uncommon. 
 
 Gmelin, in the last edition of Linnaeus, has 
 included Cos among the Lapides arenarii, which 
 he rightly arranges in three divisions, with a sili- 
 ceous, calcareous, and argillaceous cement. Of 
 the latter he particularises that of Fahlun, in Swe- 
 den, where it forms the bottom of the copper- 
 mine ; and that found in many countries, where it 
 is used for slates. The sand-stone of Derbyshire 
 is chiefly argillaceous, as is probably the flag-stone 
 of Oxfordshire. To this class also generally be- 
 longs the sand-stone found in coal-mines, which 
 sometimes bears vegetable impressions. Some 
 sand-stones present layers of variegated colours, 
 the cement being probably argillaceous, tinctured 
 with iron in various proportions *. 
 Saussure mentions the following : 
 Argillaceous sand-stone, in vertical beds, or 
 arrects, which he says cannot be the effect of a 
 
 * Mr. Jameson says (Dumf. 166) that the cliffs of Hawthorn- 
 den are of red sand-stone : argillaceous or siderous ? The same 
 question may be applied to the chain of mountains behind our set- 
 tlements in Notasia, or New Holland, which have been found im- 
 passable. Voy. de Peron, Paris 1808, i. 3Q3. From the sea to that 
 chain the radical rock is siliceous sand-stone. 
 
MODE Vni. ARGILLACEOUS GI.UTENITE. 297 
 
 simple subsidence, but implies a " refoukment en 
 sens contraire, which has broken and raised beds 
 originally horizontal." ] 166. 
 
 A fine argillaceous sand-stone, speckled with 
 mica. 1442. 
 
 The beautiful pierre de Moravie seems of this 
 kind : it is white, with purple lines *. 
 
 * Gallitzen, Recueil des Norm des Mineraux, Brunswick 1801, 
 4to. Bom mentions a sand-stone of Siberia, containing nodules of 
 malachite. In Thuringia a sand-stone is found which is worked as 
 an ore of copper; and it also contains silver, cobalt, and lead, 
 Brongn. ii. 224. 
 
DOMAIN IV. 
 TALCOUS. 
 
 MAGNESIA. 
 
 THIS earth seems first to have been dis- 
 covered, or at least sold as a remedy, by 
 an ecclesiastic at Rome about the begin- 
 ning of the eighteenth century. Under 
 the name of magnesia alba, it was proposed 
 as a universal medicine, while it could do 
 little more than supply the place of the 
 
DOMAIN IV. TALCOUS, 
 
 Lemnian earth, and other boles. As Theo- 
 phrastus, however, in describing the stone 
 called magnetes, says it may be turned on 
 a lathe, and has a silvery appearance, Dr. 
 Kidd agrees with Hill, that the ancient 
 Greeks called the load-stone heraclea, but 
 the more modern magueies; and Pliny's 
 description of the stone brought from Mag- 
 nesia, in Asia, seems to belong to a talcous 
 substance*. 
 
 Hoffman, Black, and Bergman, contri- 
 buted to establish the difference between 
 magnesia and lime. It seems originally to 
 have been prepared from nitre; but sea- 
 water contains the sulphate of magnesia, 
 a salt composed of this earth and sulphuric 
 acid; and which is also found in many 
 springs, particularly at Epsom, whence it 
 was called Epsom salt. 
 
 Magnesian or talcous earth is infusible 
 in the strongest heat. It does not form 
 
 * Kidd, i. 91. It is singular that the modern Italians have also 
 a calamita lianca, or white magnet, which is described as fibrous, 
 and probably belongs to the same description. Ferber, Italy 88, 
 says it is a white hardened bolus, striated like asbestos. 
 
300 
 
 DOMAIN IV. TALCOUS' 
 
 phosphorets, like the three other alkaline 
 earths, lime, barytes, and strontia. 
 
 In talc it sometimes amounts to one half 
 of the composition; but in the other sub- 
 stances, such as steatites and serpentines, 
 it is only from twenty to forty; but its 
 power is so great as sensibly to alter the 
 appearance and qualities of the stone. The 
 chrysolite or peridot of the French, con- 
 taining about one half magnesia, belongs to 
 this division; and is remarkable as the only 
 magnesian gem. 
 
 The deserts of Siberia are annually co- 
 vered with efflorescences of Epsom salt, so 
 as in the short summer to resemble snow. 
 The talcous rocks in general present a dis- 
 criminating character in their unctuous 
 appearance; they have however, in some 
 cases, been confounded with the argilla- 
 ceous, which occasionally assume the soft- 
 ness and silky lustre of the magnesian. 
 The presence of magnesia is often indi- 
 cated by a green colour. 
 
MODE I. TALC. 30 1 
 
 MODE I. TALC. 
 
 Of this beautiful substance, considered as a Distinctions, 
 rock, there are two principal structures : the 
 COMMON talc, which occurs in translucent Common, 
 leaves, sometimes as large as four or five feet in 
 diameter, and which chiefly comes from the 
 Uralian mountains of Russia, whence it is called 
 Muscovy talc; and what may be called MASS- 
 IVE talc, consisting of minute scales, irregularly 
 '-agglomerated, as in the substance called the 
 chalk of Briancon, which, from its farinaceous 
 decomposition, and other circumstances, cannot 
 justly be regarded as a soft steatite, but must 
 belong, on the contrary, to this division. It 
 must at the same time be remarked, that the 
 deficiencies of all our mineralogic systems, con- 
 cerning so common a substance as talc, are not 
 a little surprising. The grave and profound 
 Walleri us justly confines the appellation of talc 
 to the two substances above mentioned ; but the 
 science has continued to suffer by the confusion 
 of two very distinct branches, petralogy and 
 lithology, every minute substance found in a 
 vein, or parasitic, disturbing the attention from 
 the grand features of nature. The magnesian 
 
502 DOMAIN IV. TALCOUS. 
 
 rocks, in particular, have never been described 
 with that attention which their curiosity and 
 importance authorise. 
 
 STRUCTURE I. COMMON TALC. 
 
 Characters. Texture, finely foliated, and of a glassy appear* 
 ance ; level, undulated, or involved. 
 
 Hardness, cretic. Fracture, slaty. Fragments, 
 amorphous, rather sharp, but the corners easily 
 crumble into white powder. 
 
 Weight, pumicose. 
 
 Lustre, shining. Translucent, semi-transparent, 
 sometimes transparent. 
 
 The colour is commonly a silvery grey, but 
 often also light brown ; and specimens of this co- 
 lour are found, though very rarely, with beautiful 
 metallic veins, or illinitions. It is also found of 
 various beautiful tints of green, sometimes change* 
 able, being reflected as it were through a white 
 surface. 
 
 sites. It abounds in the Uralian mountains; and it 
 
 appears, from the accounts of Gmelin and Pallas, 
 that it sometimes may be said to form whole 
 mountains, while a mountain of quartz appears on 
 one hand, and a mountain of felspar on the other, 
 so as to present elements of granite on a vast 
 scale. Fine talc is also found in the mountains 
 
MODE I. TALC. 303 
 
 of Tyrol, whence it Was brought to Venice, and 
 when exported from that mart assumed the name 
 of Venetian talc. When calcined into an impal- Venetian talc. 
 |>able white powder, it was found a far more inno- 
 cent paint for the ladies than bismuth, formerly 
 used, but which is apt to become black, from the 
 approach of sulphureous, and some other fumes, 
 or even perfumes. An accident of this kind, ope- 
 rating hysterically, as not unusual with the sex, 
 may have occasioned the invincible aversion from 
 perfumes entertained by the Roman females. But ' 
 as white is now rarely used, calcined talc is mixed 
 with carmine, to form an elegant rouge ; which is 
 laid on with a bit of cotton wool, and rubbed off 
 with as much ease as hair powder. 
 
 Molina's able account of Chili affords the fol- of Chiu. 
 lowing information : 
 
 " Muscovy glass is there found in the greatest 
 perfection, not only for its colour, but for the size 
 of the pieces which may be obtained. It is gene- 
 rally used for glazing, and artificial flowers. The 
 plates of this mineral, which are used for windows, 
 and which are here much esteemed, because they 
 are pliable, and less fragile than glass, are often a 
 foot in length ; and I am convinced they might be 
 obtained two feet, if a little more care was taken 
 in the quarrying. This substance is as white and 
 transparent as the best glass ; and it has a quality 
 
304 DOMAIN IV. TALCOUS. 
 
 which seems peculiar to it, that of preventing pas- 
 sengers from seeing those within the apartments, 
 while these perfectly discern objects without. A 
 second kind of this glass is less esteemed, which, 
 though found in plates of a foot square, is spotted 
 with yellow, red, green, and blue; and conse- 
 quently is not used as the former. It might be 
 called mica variegata."* 
 
 In the Swiss Alps a beautiful talc is found, of a 
 changeable green, on silvery white, with thin leaves 
 forming contorted masses, adhering to a magne- 
 sian rock. Talc also occurs in leaves of various 
 sizes, from half an inch to six or twelve inches, 
 in granitic rocks, where it supplies the place of 
 mica. When not larger than mica, it is here 
 called micarel, genuine mica being ranked among 
 the siderous substances. Mr. Kirwan has given 
 the name of talcite to a parasitic substance, in 
 the form of small scales, loose, or slightly co- 
 herent, 
 chalk of The gradation of the involved or contorted talc 
 
 Jinati^on. 
 
 of Swisserland, to the chalk of Brian^on, or of 
 Dauphiny, is sufficiently apparent. The latter is 
 used by the French tailors in marking the shapes 
 on broad cloth, whence the name of chalk has 
 
 * Molina, Stor. Nat. del Chili, p. 77- The French translation 
 is very inaccurate. 
 
MODE I. TALC. 305 
 
 been improperly bestowed. The gold and silver 
 mica of many writers seem rather to be talcous or 
 micarel ; as the large brown talc sometimes verges 
 to a golden colour, and it is suspected that no 
 iron is found in either. 
 
 The Muscovy talc has been used instead of 
 glass for windows and lanterns, especially on 
 board of ships, where it is not subject to be broken 
 by the firing of cannon*. It was formerly con- 
 founded with laminar selenite ; and both were 
 called glades Maries, or the ice of the Virgin 
 Mary ; as the latter is still called by the labourers 
 at Montmartre pierre de Jesus, because it served 
 as a glass before little prints of the Saints. 
 
 Aspect 1. Large foliated talc. White, from 
 the Uralian mountains. 
 
 Greenish, from Tyrol. 
 
 Brown, from the Uralian mountains. 
 
 The same, with metallic lines, red, green, and 
 blue, perhaps from the vicinity of copper-mines. 
 
 Aspect 2. Undulated. Of various tints, from 
 same countries. 
 
 * It is the mica memlranacea of Wallerius, which he says was 
 brought from Archangel. 
 
 VOL. I. X 
 
306 DOMAIN IV. TALCOUS. 
 
 Aspect 3. Involved or contorted. White, from 
 St. Gothard. 
 
 Of a silvery white, and light green, from the 
 same. 
 
 Aspect 4. Mingled. Foliated talc, in small 
 plates, forming, with felspar and quartz, a very 
 large-grained granite. 
 
 STRUCTURE II. MASSIVE. 
 
 Massive talc, from the Alps of Dauphiny, com* 
 monly called chalk of Brian^on ; as vulgar appel- 
 lations are never precise, a soft steatite is some- 
 times sold under that name : but the French tailors 
 are not to be so deceived, and the genuine craie 
 de Brian$on may be had from them, leaving on 
 broad cloth a farinaceous illinition. It must how- 
 ever at the same time be observed, that when a 
 soft steatite is mingled with micarel, the impres- 
 ilojq will be somewhat similar to that of the chalk 
 of Dauphiny. Nay, micarel itself has been found 
 to decompose into -steatite*. 
 
 The rock of soft scaly steatite, of a sea-green 
 colour, discovered by Saussure in the Roth-horn, 
 
 * Gmelin, Linn. 69, describes the Creta Brianzonica as m\nu-- 
 fissime lamcllosiim; the soft steatite particulis impalpalililus. 
 
MODE i. TALC. 307 
 
 2157, appears to belong to this division. It is 
 mingled with grains of white felspar, and cal- 
 careous particles, which effervesce with acids* 
 It is so soft as to be almost friable, and splits 
 into level horizontal layers : this curious rock re- 
 poses on serpentine, and is surmounted by a mi- 
 caceous lime-slate, strongly impregnated with si- 
 derous earth. 
 
 Dr. Babington has the following varieties*: 
 " Composed of broad, shining, flexible folia, 
 closely compacted, and of a greenish w r hite co- 
 lour (Venetian talc), from Zillerthal in the Tyrol. 
 " This, from being of a white colour when re- 
 
 ' O 
 
 duced to powder, and leaving a beautiful polish 
 on the skin, has long been employed as a cos- 
 metic. Mr. Hepfner found it to contain mag- 
 nesia 44, silex 50, alumine 6. 
 
 " The same, on the surface of semi-transparent 
 felspar, of a pale reddish white colour, and shining 
 fracture, from the same place. 
 
 " A polished slab of the same, of a pale green 
 colour, and intermixed with shining silvery lami- 
 nae, from Scotland. 
 
 " Of a slaty texture, and greenish white colour 
 (schistose talc), from Bareuth. 
 
 * Cat. St. Aubyn, 38. 
 
308 DOMAIN IV. TALCOUS. 
 
 " The same, of a duller colour, and somewhat 
 more compacted, from Hungary. 
 
 " In thin undulating laminae, of a dark greenish 
 grey colour, from Fahlun, in Sweden. 
 
 " The same, more indurated, and of a shining 
 yellowish grey colour, from Zillerthal in the Tyrol. 
 
 " The same, of a divergingly striated texture, 
 and dark grey colour, from Scotland. 
 
 " Composed of small compacted scales (talcite) 
 of a white colour and silvery lustre, enclosing pris- 
 matic crystals of green quartz, from Dauphiny." 
 
 Karsten, in his catalogue of Leske's museum, 
 has the following : 
 
 " Perfectly apple green, mutably reflecting sil- 
 very white, talc, from the Venetian states. 
 
 " Talc, reflecting from the apple green, slightly 
 into yellowish, from the same place. 
 
 " Massive talc, of coarse and small granular dis- 
 tinct concretions ; and the same, indurated, which 
 is mixed with a large quantity of emery, from 
 Ochsenkopf, at Schwarzenburg, in the Erzgebirge. 
 " A fragment of a talc nodule, the fracture of 
 which is very slaty, from Tyrol." 
 
MODE II. TALCOUS SLATE. 309 
 
 MODE II. TALCOUS SLATE. 
 
 Texture, nearly resembling that of massive Characters, 
 talc, but easily divides into undulated fragments, 
 of a quarter or half an inch in thickness, the feel 
 being extremely unctuous, as that of soft steatite 
 or soap-rock. 
 
 Hardness, cretic. Fracture, foliated. Frag- 
 ments, amorphous, blunt, and soft. 
 
 Weight, carbonose. 
 
 Lustre, glimmering. Faintly translucent on 
 the edges. 
 
 The colour is changeable, greenish or reddish, 
 mingled with silvery white. It is found in the 
 Swiss Alps, in Scotland near Portsoy, and in 
 many other primitive regions. Being of recent 
 observation, it is little known in books of mine- 
 ralogy. It may perhaps be the laminar steatite 
 of Wallerius, which he describes as of a grey 
 colour, and found at Norberg, Salberg, and Gar- 
 penberg in Sweden. 
 
 To this Mode may also be referred the follow- Taicous slates 
 
 * of Saussure. 
 
 ing rocks, described by Saussure : 
 
 " The asbestiform steatite rested on a stone, 
 which Mr. Struve says had received from Wer- 
 ner the name of chlorite slate. But the speci- 
 
510 DOMAIN JV. TAJ.COUS. 
 
 mens before me are evidently of a composite 
 rock. 
 
 " We there see schistose parts of a greenish 
 grey, sparkling, which have the form of small 
 scales of chlorite; but these parts are very re- 
 fractory, and do not yield the glass of chlorite, 
 They do not form the tenth part of the mass of 
 this rock, in which parts of real steatite, of a 
 greenish white, predominate, soft, translucent, 
 and perfectly characterised. 
 
 <c We besides find in this stone parts crystal- 
 lised in little straight plates, rhomboidal, nearly 
 rectangular, of a greenish grey, extremely bril- 
 liant, almost of a metallic lustre, a little harder 
 than steatite in mass, but with a grey streak. 
 These plates lay on one another, and form in the 
 stone glistening spots of an irregular form, three 
 or four lines in diameter, and one or two in 
 thickness. Viewed with a microscope, the sepa- 
 rated plates appear transparent and colourless - 9 
 but their reduplication renders them scarcely 
 translucent in mass. Under the blow-pipe they 
 show themselves very refractory ; they become 
 opake, and covered only on their edges with a 
 dark and brilliant amel. I cannot consider them 
 but as a species Qirayonnant, strahlsfem, of Wer- 
 ner, much like that of 1437* though with some 
 differences, 
 
MODE II. TALCOUS SLATE. 
 
 " As then this schistus results from the assem- 
 blage of diffeiji6nt stories, all of the talcous class, 
 I call it composite magnesian schistus. 
 
 " 1917. The collection that Mr. Struve sent 
 to me contains a stone, with a label, which sig- 
 nifies that Mr. Werner had named it an indis- 
 tinct variety of chlorite slate. Perhaps in this 
 instance, as in the former, Mr. Werner assigned 
 the name from specimens different from what I 
 received. In fact these are still farther removed 
 from chlorite. 
 
 " The rock before me, and of which I possess 
 two large pieces, is of a black inclining to green. 
 Its fracture is laminar, with plates often undu- 
 lated, very thin, separable into very fine flakes, 
 the direction of which varies in different parts of 
 the same piece. This fracture is indifferently 
 bright, and of a lustre inclining to the unctuous, 
 as well as its touch. It is translucent on its 
 edges, to the thickness of half a line; the very 
 fine laminae appear white and colourless : but 
 those which are thicker, when looked through, 
 appear of a beautiful leek green. 
 
 " This stone is soft, and may be scratched 
 even with the nail ; the streak being of a whitish 
 grey, but little brilliant. Moistened by the 
 breath, it exhales a strong earthy smell. Its 
 specific weight is 2,905. 
 
312 DOMAIN IV. TALCOUS. 
 
 " Exposed to the blow-pipe, this stone melts 
 with difficulty into a greenish grey glass, semi- 
 transparent, which forms a globule, of the tenth 
 of a line at most. 
 
 " It has therefore no resemblance with chlo- 
 rite, and, being obliged to give it a name, I have 
 called it laminar magnesian schistus. 
 
 " We find enclosed in this stone some clusters 
 of crystals of the rayonnant, or strahlstein, which 
 I have described in the preceding paragraph; 
 and some detached crystals of octahedral iron. 
 It is found at Weysler Stoude, in the valley of 
 Urseren." 
 
 MODE III. MICAREL SLATE. 
 
 Distinctions. This has commonly been confounded with 
 mica slate, and uas the same general appear- 
 ance ; the spangles having however sometimes 
 more of the silver lustre, and in other examples 
 more of the unctuous cast of talc, than is ob- 
 servable in mica slate, where the magnesia is 
 strongly impregnated with iron. It has also 
 the usual adjuncts of talc, and seldom contains 
 garnet, or the other siderous substances, that are 
 found in mica slate. In decomposition, it some- 
 times forms plates or illinitions of steatite be* 
 
MODE IV. STEATITE. 313 
 
 tween plates of quartz. It abounds in all the 
 primitive countries, but has not yet been distin- 
 guished from mica slate. 
 
 Aspect 1. Micarel slate, from the bed of the 
 Ganges, near Sirinagur. 
 The same, from the Alps. 
 The same, from Scotland. 
 
 Aspect 2. Dendritic, from Spain, 
 
 MODE IV. STEATITE. 
 
 This substance so much resembles fine soap, 
 that in Cornwall, where it abounds, it is com- 
 monly called soap-rock. 
 
 Texture, compact, finely granular, and unc- Characters. 
 tuous. 
 
 Hardness, cretic. Fracture, sometimes un- 
 even, sometimes conchoidal. Fragments, amor- 
 phous, blunt. 
 
 Weight, carbonose. 
 
 Lustre, dull, unctuous, sometimes glimmer- 
 ing, with particles of micarel. Translucent on 
 the edges. 
 
 The most common colour is white, sometimes 
 delicately streaked with red, so as perfectly to 
 
BOMAIN IV. TAX.COUS. 
 
 resemble marbled soap. It also occurs greyish, 
 greenish, and more rarely yellowish, and is some- 
 times dendritic, or spotted*. 
 
 Klaproth has analysed the steatite of Corn- 
 wall, of which he gives the following account: 
 of the The steatites of Cornwall (talcum smectis* 
 
 Lizard, 
 
 Linn.) occur at the Cape Lizard, in serpentine 
 mountains, which it cuts through in small, per- 
 pendicular, or rake veins. The finest sort of it 
 is white, with bluish or reddish spots, resembling 
 marble. When fresh from the mine it is so soft 
 that, like soap, it may be abraded with the 
 knife. It is used in making porcelain. The 
 working of these mines is carried on by the 
 House of the porcelain-manufacture at Wor- 
 cester, which pays <20. sterling for the ton of 
 20 cwt., because the bringing it out to the day 
 is extremely uncertain and dangerous, the ser- 
 pentine rock breaking in so frequently. There 
 also occurs in these mines another sort of it, less 
 fine, and having spots of iron ochre; as well as 
 a third, brown-red variety, mingled with green. 
 Not far from thence, at Euan minor, also in ser- 
 pentine, there is found both a grey-white and a 
 light slate-blue soap-rock, or steatite, and also 
 
 * The dendritic occurs in Saxony, and near Kildrummy, Scot- 
 land. 
 
MODE IY. ST-EATITE. 
 
 a whitish steatite, crossed by calcareous spar, 
 which gives it a smooth shining fracture. 
 
 " It was the first, finest sort of steatites, that 
 was the subject of the following analysis." 
 
 The result is, silex 48, magnesia 20, argil 14, 
 oxyd of iron 1, water 15*. 
 
 Da Costa has given more particular inform 
 ation concerning the soap-rock of Cornwall. 
 
 " The soap-earth, or steatites, is found in a 
 sandy creek, not much above a mile to the north- 
 west of the Lizard point : the sand is very 
 smooth and pleasant, of a mixed colour, light 
 and blue, and when the tide is out, affords many 
 turning and winding passages betwixt the rocks, 
 also blue, and the vast masses of cliff, which the 
 violence of the sea has separated from their mo- 
 ther land, and from each other. There are also 
 two grots, one called Kynas hole, into which 
 those sandy walks lead; but in them nothing 
 remarkable is to be found, not even marine 
 plants, it being altogether too often washed by 
 the tides on the surface of these rocks. There is 
 sprinkled here and there a smooth, fat, and seem- 
 ingly unctuous kind of incrustation, in colour 
 and feeling much like to the natural appearance 
 of bees'- wax, or tallow, and much of the same 
 
 * Aual. Ess. i. 462. 
 
3 16 DOMAIN IV. TALCOUS. 
 
 nature with the white part of the soapy rock ;, 
 but whether it exudes from the crevices of the 
 rocks, several of which have little chinks (filled 
 with this heterogenous matter), capable of emit- 
 ting what they contain, or whether this sub- 
 stance is first washed off by the sea from those 
 veins, and is again returned by the force of the 
 waves, till it incrusts the rocks, time and further 
 inquiries only can determine."* 
 
 " Most of the stones within reach of the sea 
 are covered with an adventitious and most beau- 
 tiful enamel ; red, white, green, yellow, in thin 
 lucid scales, sometimes riding on one another in 
 different crusts. In the eastern part of this 
 cove, as the Cornish people call it, or creek, the 
 substance of the rocks, and the sides of the cliff, 
 are more gritty, and being soft, crumbling, and 
 of a reddish colour, mixed with veins of white, 
 like marble ; and the purest, and most beautiful, 
 lying in veins like metals. It is here more par- 
 ticularly called the soapy rock; as, by its 
 unctuousness, smoothness, and variegations, it 
 greatly resembles the finest kind of soap. 
 
 " The veins of steatites are of different 
 breadths; some run under the sea, some to near 
 the top of the cliff, and some through the cliff 
 
 * Da Costa, 37- 
 
MODE IV. STEATITE. 317 
 
 up into the country, and seem in their course to 
 cross the tin loads. 
 
 " Nearer the Lizard than the soap rock is 
 another cove called Pintrith, which affords a 
 greyish impure steatites, spotted with black. 
 
 " The new soap rock, lately discovered, is at 
 Gew Grez, or Grez cove, in the tenement of 
 Kynas, in Mullion parish : it is about three 
 miles from Mullion town, and about a mile from 
 the old soap rock, or cove, which lies farther 
 southward. The entrance into the creek or 
 cove is very steep, craggy, and horrid : on the 
 right hand (in descending into the creek) the 
 hills are crested with naked rocks, or cairns, as 
 the Cornish people call them : the sides have 
 also many, but they are small. About half way 
 down the cove, a very small current of water 
 traverses it, in a very serpentine manner, and 
 discharges itself near the load, or principal vein 
 of the steatites. On the right hand, as you de- 
 scend the cove, it grows more craggy and much 
 narrower ; and a few yards lower, on the same 
 side, lies the main vein or load of steatites. The 
 various sorts are all blended together in spots, 
 sometimes in greater quantities in one place 
 than in another. In the white and red veined 
 steatites, pieces of a compact, hard, slightly pel- 
 lucid, sparry substance, are frequently found: 
 
3J8 J50MAIN IV. TALCOU3. 
 
 the main vein, or load, is about eight feet over $ 
 it does not consist purely of the steatites, but 
 also holds quantities of rubble, or fragments of 
 a hard, smooth, dusky, greenish, and red co- 
 loured talcy-like fissile stone, called by the in- 
 habitants a variegated killas, Some small pieces 
 of white spar are also met with, but rarely. 
 About two hundred paces higher, on the left 
 hand, I found a soft and very greasy straw- 
 coloured steatites : in the sides of the country, 
 that is, of the solid strata which enclose the 
 vein, and intermixed with it, lay a reddish brown 
 steatites, but the straw-coloured kind was in the 
 greatest quantity: further down, near the level 
 of the sea, the steatites load has been more regu* 
 larly traced, and makes a course of about four-* 
 teen inches wide between regular sides : the left 
 hand side of the cove is quite perpendicular, 
 and consists of a hard black stone, seemingly 
 divided into strata by small horizontal fissures, 
 placed at great distances from each other* The 
 other sides of the cove are more open and rugged, 
 the sea beats strongly into the creek, which at 
 low water has a small sandy beach/'* 
 
 Of this substance there are two very distinct 
 structures ; the soft, already mentioned, and the 
 
 * Da Costa, 37. 
 
MODE IV. STEATITt. 
 
 hard. To the last the following interesting ob- 
 servations of Patrin chiefly refer ; and they are 
 the more freely extracted, because his works, 
 like those of Saussure, though of the greatest 
 importance to the science, have never been 
 translated, and remain new to the mere English 
 reader. 
 
 " There is often so little difference between 
 ollite and steatite, that Saussure* who was so 
 well acquainted with rocks, sometimes uses 
 these two denominations in speaking of the 
 same substance; or, at least, he calls steatite ste ;$f t e e ? nd 
 the substance which forms the base or the paste 
 of ollite. The greatest, or the only difference 
 which, in fact, exists between them is, that 
 steatite is a more simple and more homogenous 
 compound, and that it is also more unctuous, 
 than ollite. 
 
 < It may be said, that steatite is to the ol* 
 lites what corncenne is to porphyries. It is a 
 paste which contains crystals, or, at least, dis- 
 tinct particles, of mica, talc, sometimes of as- 
 bestos or amianthus ; as the base of porphyries 
 contains crystals of felspar, schorl, and grains of 
 quartz. Steatite is even observed, as that of the 
 summit of Roth-horn, near Mount Rosa, which 
 contains grains of felspar; and this mixture also 
 forms ollite. 
 
320 DOMAIN IV. TALCOUS. 
 
 " A steatite is found in Corsica, which is 
 solid, of an even tissue, of a uniform olive-green 
 colour, semi-transparent and unctuous: it is 
 what the Germans call nephritic stone, on ac- 
 count of its resemblance to the jad of the river 
 of Amazons, which has that name by excel- 
 lence. This steatite is, with a slight difference 
 of colour, exactly like the lard-stone of China. 
 
 " Saussure gives the description of a steatite 
 of St. Gothard, which he calls asbestiform steat- 
 ite : it is very interesting, because it shows the 
 transition of one stone to another. 
 
 " It is of a grey, approaching to yellow or 
 green, and it much resembles asbestos, but its 
 fibres are much larger, softer, and more unc- 
 tuous. Its longitudinal fracture shows large 
 fibres, parallel to one another, irregularly pris- 
 matic, as much as three inches long: their lus- 
 tre middling, sometimes bright; but it is owing 
 to a bed of talc, which covers the fibres of the 
 stone. 
 
 " Its transverse fracture is uneven, splintery: 
 translucent on its edges: soft, and scratches with 
 the nail. The small fragments melt by the 
 blow-pipe into a black globule. 
 
 " It is then evidently, Saussure says, a species 
 intermediate between talc, steatite, and asbestos- 
 
 " Rome de Flsle mentions a greenish steatite 
 
MODE IV. STEATITE. 
 
 of Corsica, crystallised in hexagonal plates, 
 placed horizontally; and which are only, he 
 says, distinguishable from mica as they are 
 duller, and are oily and unctuous. 
 
 " I have similar crystals, which are found in- 
 laid in topazes and emeralds of Siberia; and as 
 I perceive the insensible transitions from pure 
 mica to this unctuous mica, I look upon this 
 last as a simple modification, or perhaps the 
 commencement of the decomposition of the real 
 mica. 
 
 " Saussure has observed on Mount Cervin, 
 near Mount Rosa, a steatite which he has called 
 specular. It terminates the last rock before the 
 snow. He has given it that name because its 
 surface is as smooth as a mirror, and as polished 
 as this species of rock admits. Its colour is a 
 very dark bottle-green; its fracture irregularly 
 schistose ; it is soft, and is easily scratched with 
 grey streak*. 
 
 " Saussure has elsewhere seen, and particu- 
 arly near the convent of Mount St. Bernard, a 
 arge rock of a quartzy nature, whose entire 
 urface is polished so as one may see one's self 
 n it, as in a looking-glass. He justly regards 
 this phenomenon as an effect of crystallisation. 
 
 * See Sams. 2258. 
 VOL. I. Y 
 
BOMAIN IV. TALCOUS. 
 
 t " I have found in the lead-mine yielding silver 
 of Kadainsk, in Daouria, near the river Amur, a 
 steatite of a very remarkable variety. Although 
 of a tolerable firmness, it is so unctuous, that in 
 drawing the finger along its surface, it gives it 
 the same gloss as it would to a piece of soap. 
 It is of a perfectly homogenous tissue, although 
 composed of very distinct alternate layers, from 
 half a line to a line in thickness, of which some 
 are of a beautiful milk white, and the others of 
 an ochre yellow. These layers, although con- 
 torted, are parallel among themselves ; and as it 
 generally presents segments of concentric cir- 
 cles, the stone has the appearance of petrified 
 wood. 
 
 " I had brought away two specimens, and I 
 wished to wash one of them ; but it was scarcely 
 wet before it broke into little fragments, the size 
 of a pea, all the fractures of which were per- 
 fectly conchoidal, and the angles very sharp. 
 The mark of the layers has almost entirely dis- 
 appeared in these fragments, which have as- 
 sumed a uniform tint, between white and yellow. 
 The thinnest fragments are translucent on the 
 edges."* 
 
 This stone must resemble the circular talc 
 described and figured by Wallerius. 
 
 * Patrin Min. i. 1Q5. 
 
MODE IV. STEATITE. 
 
 The softer steatite chiefly occurs in veins in 
 serpentine, and in nodules in basaltin* and 
 Saussurite : but the harder forms rocky masses, 
 else the substance could not have appeared with 
 propriety in the present treatise. The rock of 
 hard steatite, described by Saussure, may serve 
 as an example: he discovered it on his journey 
 between Nice and Genoa, on the sea-shore, of 
 the height of 15 or 20 feet. The exterior surface 
 is shining: here reddish, there of a silvery hue, 
 and rather soft to the toucli. 
 
 " It splits in irregular fragments, rather ap- 
 proaching to the rhomboidal. Its fracture is 
 schistose, irregular, and otherwise very like its 
 exterior surface: it gives a grey streak- is soft, 
 and rather heavy ; odour earthy ; easily melts 
 into a grey glass, which sinks on the support; 
 it has no effect on the magnet. 
 
 <c The rock composed of this stone is divided 
 by veins of spar and quartz ; and this last con- 
 tains, in places, pieces of green hornblende. 
 
 " Some parts of this rock are of a bright deep- 
 brown violet colour. The fracture presents schis- 
 tose laminae, irregular, small, and often con- 
 choidal ; the streak is of a reddish grey ; like 
 
 * Fine specimens of this kind are brought from the isle of Rach- 
 lin, on the north of Ireland, celebrated as the retreat of Robert I. 
 king of Scotland from the English power. 
 
 Y 2 
 
324 DOMAIN IV. TALCOUS. 
 
 the other, it is soft, rather heavy, and very fusi- 
 ble, but its glass is black, while that of the other 
 is grey ; it is doubtless a superabundance of iron 
 which gives these pieces their red colour, and 
 causes their glass to be black ; but this iron is 
 under the form of oxyd, or what was called calx ; 
 for neither does this stone affect the magnet. 
 
 " This rock is succeeded by another, smaller, 
 and of the same nature, on which stands a little 
 chapel, dedicated to St. Andrew, which has given 
 it the name of Scoglio di St. Andrea. 
 
 " This rock stretches along the sea; it is 
 afterwards covered by a granular serpentine, 
 similar to that of La Garde, 1342, which, like 
 that, splits in small polyhedral fragments, irre- 
 gular, the faces coloured by ferruginous irides- 
 cences, and which falls like it in decomposition. 
 This same stone is still seen in the ascent beyond 
 Peggi."* 
 
 
 STRUCTURE I. SOFT STEATITE. 
 
 White soap-rock, from Cornwall. 
 
 The same, mottled with red or blue, from the 
 same country. 
 
 The same, rather harder, from Portsoy, in Scot- 
 land. 
 
 Sauss. 1357- 
 
 
MODE IV. STEATITE. 325 
 
 The same, with elegant variegations of red. 
 
 The same, greenish, in serpentine. 
 
 White steatite, with black dendrites, from Sax- 
 Ony. 
 
 Karsten mentions a massive steatite, which is 
 found in extensive strata at Thierschein; but he 
 does not distinguish between the soft and the hard 
 kinds *. 
 
 " Steatite, crystallised in hexahedral prisms of a 
 middling size, terminated by six planes, the edges 
 formed by the meeting of the lateral and acumi- 
 nating planes, truncated, but in other respects cir- 
 cumstanced as usual, in massive steatite, from 
 the same pi ace. "f 
 
 Soft steatite, called Spanish chalk, but probably 
 from the Alps of Dauphiny. 
 
 Soft steatite, from New Caledonia, where the 
 savages mix it with their food. This custom is 
 also known to the savages on the Orinoco; nor 
 is it unknown in the German country of Lusatia. 
 The Arabs are said to use it in their baths instead 
 of soap, and it is also used as fullers' earth. 
 
 Steatite, in basalt, from Skey, and other western 
 isles of Scotland. 
 
 
 * Leske, 131. f Ibid. 
 
DOMAIN IV. TALGOUS. 
 
 STRUCTURE II. HARD STEATITE. 
 
 Distinctions. $ o f t steatite may be scratched with the nail ; 
 but when the coherence is such that this substance 
 does not yield to the knife of copper, or even 
 sometimes of steel, it must assume the name of 
 hard steatite ; the hardness extending from the 
 gypsic to the marrnoric, and even to the basaltic. 
 It must here be premised that the little Chinese 
 idols, formerly supposed to be of indurated steat- 
 ite, are now known by chemical analysis to belong 
 entirely to the Argillaceous Domain; a proof,. 
 among many others, of the insufficiency of exter- 
 nal characters, and that mineralogy can derive no 
 certain light, except from the lamp of chemistry. 
 
 Aspect 1. Compact. Hard steatite, approach- 
 ing to serpentine, of a dark green colour, with 
 chlorite, from Silesia. 
 
 Of a pale green, with black lines, from the Alps 
 6f Dauphiny. 
 
 The early writers sometimes confound the hard 
 steatite with ollite. 
 
 Aspect 2. Laminar. The plates are com- 
 monly curvedj and occasionally have a fibrous 
 fracture. It is translucent on the edges, and 
 
MODE V. OLLITE. 327 
 
 sometimes entirely. Mr. Kirwan calls it foliated, 
 or striated steatite ; and says that it is generally 
 found in independent amorphous masses, some- 
 times investing or intersecting serpentine. 
 
 " Leek green, inclining to olive green, curved 
 foliated steatite, from Norway. * 
 
 " Mountain green, partially sprinkled with 
 black, foliated steatite, from Z6bliz."| 
 
 MODE V. OLLITE. 
 
 Texture, earthy, rather schistose. Characters. 
 
 Hardness, cretic or gypsic. Fracture, un- 
 even, somewhat slaty. Fragments, amorphous, 
 blunt, often laminar. 
 
 Weight, carbonose, sometimes granitose. 
 
 Lustre, dull, sometimes glimmering, unctuous. 
 Opake; if translucent on the edges it approaches 
 to hard steatite. 
 
 The colour is often greenish grey, or blackish 
 green; sometimes yellowish, or reddish. It is 
 often spotted, like a snake, whence the ophites 
 of the ancients, which certainly belonged to this 
 kind, and not to the green porphyries, as has 
 hitherto been supposed by a long train of mi- 
 neralogists, copying each other. It differs from 
 
 * Leske, 131. f Ib. 
 
DOMAIN tv. TALCO^S. 
 
 serpentine, by the grain being finer and fatter; 
 and is more easily cut with a knife. 
 That of Chiavenna has been analysed by 
 Weigleb, who found, magnesia 38, silex 38, 
 argil 6, iron 15. Who would suppose, after this 
 analysis, that Werner should place this sub- 
 stance among the argillaceous, with an equal 
 contempt for chemical principles, which can 
 alone afford any solid foundation for the science, 
 as when he places (he corindon gems among 
 the siliceous, though they do not contain one 
 atom of silex ! The paternal love of his own 
 system must be violent indeed, when it leads to 
 such contempt of every principle on which the 
 science has been founded. 
 
 This substance has commonly been called 
 lapis ollaris, which"has been translated pot-stone, 
 from the use to which it has been applied, even 
 Ancient. f rom remote antiquity, Pliny mentioning that 
 the stone of the isle of Siphnus, in the Grecian 
 Archipelago, and the greenish stone of Como, 
 in Italy, were both used in his time to make 
 vessels for cooking food. Wad, in his account 
 of the Borgian museum, mentions several Egyp- 
 tian monuments of ollite, chiefly small statues. 
 The varieties are : 
 
 Ollite, of a blackish green, with grass green 
 spots. 
 
MODE V. OLLITE. 329 
 
 Ollite, of a yellowish green. 
 
 Of an olive green, with larger and smaller 
 veins of a greyish black, spots of a liver brown, 
 and small specks of an Isabella yellow. 
 
 Of an olive green, with grass-green spots. 
 
 Semi-transparent, of an emerald green, with 
 irregular oblong spots of an ochre yellow. This 
 would rather seem to be a hard steatite. 
 
 Of a greenish grey, with a cast of blue. 
 
 Of a yellowish grey, verging on Isabella co- 
 lour. 
 
 Of a foliated structure, resembling, as he adds, 
 the laminar steatite of Karsten. 
 
 Two other relics are of a brownish black, and 
 a greenish black ; in a third, mingled with a few 
 grass-green spots. 
 
 The learned author has added the following 
 observations : 
 
 " To this class, which affords so many Egyp- Thebaic 
 
 J &%/ r stone. 
 
 tian remains in the Borgian museum, belongs 
 the Thebaic stone of the ancients, which con- 
 stituted large portions of mountains, the quar- 
 ries being mentioned by Theophrastus. Pliny 
 has observed that it was black, or of a dark co- 
 lour, and marked with golden spots *. He 
 also observes that it yielded a juice, whence 
 
 * xxxvi. 8, 22. 
 
330 DOMAIN JV. TALCQUS. 
 
 it must have been soft, and was used for mor- 
 tars, as, from its natural benignity, it seemed 
 peculiarly fitted for pounding medicines. If we 
 compare these indications with any Egyptian 
 stone, we shall find they agree with this only, 
 the colour being frequently black or dark, and 
 sometimes spotted with golden mica, of a soft 
 nature, and used for mortars, one of the remains 
 being of that description." 
 
 It has already been mentioned in theclescrip- 
 tion of green porphyry, that the Theban ophite 
 of Lucan, and the dark ophite of Pliny, were 
 spotted ollites, which in fact bear far more re- 
 semblance to the skin of a snake than green por- 
 phyry, to which the appellation has been care- 
 lessly transferred. 
 
 ?hite Boot, physician to the emperor Rodolph II. 
 
 1576 1612, published a treatise on precious 
 stones, certainly very able and acute for that 
 period, for he was the first who, in treating of 
 the diamond (lib. ii. c. 1. p. 11?. edit. 1636. 
 8vo.), remarked that it belongs to the inflam- 
 mable substances ; an idea also, upon quite dif- 
 ferent and original grounds, adopted by the 
 greaj: Newton. This author, after quoting Di- 
 oscorides and Pliny, observes that the ophite is 
 a grey stone, found at Zoblitz, and used in 
 making pots or vases, and the reputation of its 
 
MODE V. OLLITE. 33 J 
 
 medical qualities continued to his day. The 
 ollites of Zoblitz in Saxony are still well known. 
 Laet, in his treatise on Gems, 1647, 8vo. 
 p. 168, rather confuses the question, as usual 
 with commentators, but quotes Gesner, who 
 seems the fountain of the error, that ophite is a 
 green marble, or porphyry, owing to his merely 
 reading one sentence of Pliny, without adding 
 the subsequent context. Laet says, that he re- 
 ceived from Crusius a fragment upon which he 
 had written, " A fragment of the cup of Ed- Ophite of 
 
 Edward IV. 
 
 ward IV. King of England, formed of the stone 
 called ophites, useful against poison, the gift of 
 H. Morgan, 1.581." This fragment was of a dull 
 green colour, very little translucent, sprinkled 
 with crystalline spots of a bright green, and 
 pretty conspicuous if held before the light. This 
 may have been a serpentine, or ollite, with hex- 
 agonal spots of green mica, or steatite. The 
 erroneous application of the term ophite by the 
 greatest mineralogists, for more than a century, 
 will excuse even a repeated confutation. 
 
 The ollite of Como, which is still in use, is of sites. 
 a foliated texture, and greenish grey colour. 
 That of Saxony, used for tea-caddies, milk-pots, 
 and several other purposes, is of a greenish grey, 
 with irregular veins and spots of black. The 
 noble house of Inverary, the seat of the duke of 
 
DOMAIN IV. TALCOUS. 
 
 Argyle, is constructed with a dark ollite, of which 
 there are quarries in the neighbourhood; and 
 which has likewise been formed into punch-bowls 
 and vases. It is also said that the cathedral of 
 Bergen, in Norway, is built of ollite. 
 
 In the middle ages, Chiavenna had supplanted 
 Como in this article of commerce, the quarries 
 of ollite being at Pleurs, a town about two miles 
 to the north-east; but the excavations were con- 
 ducted with such little care, that in 1618 the 
 hill fell down, and buried the city, with the 
 greater part of the inhabitants*. Near Oletza, 
 in Corsica, ollite is found of a bright olive green, 
 and is worked by the lath like the others. Ro- 
 ziere, in his interesting memoir on the valley of 
 Cosseir, in Egypt, mentions that the Arabs make 
 little vases of an ollite, which they find in that 
 country. The celebrated calumet f, or pipe of 
 peace, of the American savages, is of a greenish 
 grey ollite, with reddish veins and spots, and is 
 cut with the knife into a not inelegant form, 
 with a second cavity adapted to receive a long 
 reed, which serves for what is called the stem. 
 On the west of the Missouri the savages are said 
 to use a red serpentine for -the same purpose. 
 
 \See the affecting detail of this event in Burnet's travels, 
 f So called from the French chalumcau. 
 
MODE V. OLLITE. 333 
 
 % 
 
 Nor is the culinary use of ollite unknown among 
 these rude tribes. 
 
 Greenish grey ollite, spotted with golden mi- 
 ca, from Egypt. 
 
 The same, spotted with green scales, from the 
 same. 
 
 The same, spotted with black, from the same. 
 
 These varieties belong to the real ophites of 
 the ancients. 
 
 Greenish grey ollite, with black veins and 
 spots, from Zoblitz, in Saxony. 
 
 Yellowish, from the same. 
 
 Light grey, from the same. 
 
 The same, from Como. 
 
 Yellow and green ollite, from Finland. 
 
 Karsten has the following specimens : 
 
 " Greenish white, reflecting changeably into 
 silvery white, pot-stone, from Ochsenkopf. 
 
 cc Greenish grey, spotted with reddish, pot- 
 stone, from the same place. 
 
 " Very thin slaty pot-stone, with inlaying 
 garnets, from Tyrol. 
 
 " Thin and curved slaty pot-stone, mixed 
 with quartz, from the same place. 
 
 " Very thick and curved slaty pot-stone, from 
 Ochsenkopf." 
 
 These examples are rather singular, and the 
 
334 DOMAIN IV. TALCOUS. 
 
 first may possibly be the white ophite of 
 Pliny*. 
 
 Ollite, in rude pots, &c. from the extreme 
 northern regions of America. 
 
 The same, formed into the heads of calumets, 
 or pipes of peace, from North America. 
 
 MODE VI. SERPENTINE. 
 
 Characters. Texture, small-grained, compact. 
 
 Hardness, marmoric. Fracture, rather un- 
 even, sometimes scaly, sometimes flatly con- 
 choidal. Fragments, amorphous, rather blunt. 
 
 Weight, granitose, sometimes siderose. 
 
 Lustre, dull, sometimes rather glimmering. 
 Opake; often faintly translucent on the edges. 
 
 The colours of this noble rock are surprisingly 
 rich and various. They are thus enumerated 
 by Mr. Jameson: 
 
 ce Its principal colour is green, of which it 
 presents the following varieties : leek, qil, and 
 olive green ; from oil green it passes into moun- 
 tain green, and greenish grey ; from leek green 
 
 * Saussure says, 1724, that near Zumloch, on the river Egina, 
 there is a quarry of ollite, the stone being composed of whitish 
 translucent talc, grey mica, little pyrites of a golden yellow, some- 
 times iridescent, and a little lime. 
 
MODE VI. SERPENTINE. 335 
 
 it passes into greenish black; from greenish 
 black it passes into blackish green; sometimes 
 it occurs yellow, and rarely yellowish brown: 
 further, red, of which it presents the following 
 varieties ; blood red, brownish red, peach-blos- 
 som red, and scarlet red. 
 
 <e The peach-blossom, and scarlet red colour, 
 are the rarest. 
 
 " The colour is seldom uniform ; there are 
 generally several colours together, and these are 
 arranged in striped, dotted, and clouded deline- 
 ations." 
 
 It is a primitive rock, and appears to be stra- Primitive, 
 tified, but, like granite, very indistinctly. It is 
 an important geological observation, that some 
 rocks, particularly the calcareous, assume the 
 appearance of being stratified, by incipient de- 
 composition, as Ramond remarked in the Py- 
 renees. But may not even this circumstance 
 be considered as a proof of original stratification, 
 merely rendered more apparent by the decay of 
 the softer parts; as, if there were no original 
 joints for the humidity to enter, the decompo- 
 sition would only occasion irregular crevices? 
 
 Werner and his disciples have observed near 
 connexions between the formations of trap or 
 basaltin and serpentine. When the former con- 
 tains an excess of magnesia, it becomes a re- 
 
336* DOMAIN IV. TALCOUS. 
 
 markable pierre de come of Saussure, here called 
 Saussurite, in honour of that great observer. 
 
 Patrin is perhaps the only professed writer on 
 mineralogy who has enlivened his subject by 
 variety of illustration ; and as his work will pro- 
 bably never appear in the English language, his 
 descriptions, which often contain anecdotes de- 
 rived from his own extensive travels, are given 
 with the less hesitation. 
 Patrin's " Serpentine owes its name to its colour : it 
 
 account. 
 
 is generally green, often spotted with white, 
 yellowish, brown, and sometimes reddish marks, 
 which gives it some resemblance to the skin of 
 serpents. Its green colour is owing to iron, 
 which is abundant in it, and but little oxygi- 
 nated*. 
 
 " It is generally opake ; but some of its parts 
 are occasionally semi-transparent. Though not 
 very hard, it receives a fine polish, which has an 
 unctuous appearance, like jad. 
 
 " Serpentine is a primitive rock; the forma- 
 tion has been a little posterior to that of massive 
 granite, for it is very rare to find them united. 
 It has been contemporary with that of micaceous 
 and calcareous schisti, with which it is some- 
 times seen confounded, whether in the same or 
 
 * This seems rather doubtful. 
 
MODE VI. SERPENTINE. 
 
 in distinct beds, but which alternate, and are 
 reciprocally overlaid, the one on the other. 
 
 " Serpentine is rather more abundant in na- 
 ture than traps and corniennes ; and much more 
 so than porphyries. 
 
 u It is generally found in amorphous masses, 
 like porphyries, and seldom in distinct beds. 
 It forms chains of hills or mountains, but little 
 elevated, at the foot of great granitic chains : it 
 is very rare to find it in very lofty mountains, 
 and still more rare to see it form beds (arrects) 
 approaching a vertical position, a position so 
 common to micaceous schisti. 
 
 cc In regard to the little elevation at which 
 serpentine is generally found, there is an excep- 
 tion, perhaps unique and very remarkable, in 
 Mount Rosa, where there are summits which Mount Rosa. 
 surround the central part of that mountain, 
 which are composed of serpentine, although 
 their elevation is from 100 to 1700 fathoms, and 
 upwards ; and what is also very remarkable, is, 
 that the beds of this rock are there in a position 
 most often horizontal. But even this position, 
 and the presence of serpentine at this great ele- 
 vation, are owing to the same cause, which I 
 shall explain in treating of geology ; for this 
 mountain, become famous since the travels of 
 Saussure to that region, and which is one of the 
 
 VOL. i. z 
 
338 DOMAIN IV. TALCOUS. 
 
 most extraordinary existing, is also one of those 
 which will throw the greatest light on the mys- 
 tery of the formation of primitive mountains. 
 
 " Europe is that part of the terrestrial globe 
 in which most serpentine is found ; the whole 
 front of the Alps, which looks towards Italy, 
 offers it almost every where, although these 
 mountains show but very little of it towards 
 Swisserlarid. 
 
 " It extends throughout Italy, where it is 
 called gabbro. One of the finest is that of the 
 hills of Improneta, near Florence : it contains a 
 good deal of that green, semi-transparent, and 
 satiny substance, which Saussure has called 
 smaragdite, on account of its fine colour of eme- 
 rald green. 
 
 " France has some mountains of serpentine, 
 especially in Limousin. 
 
 " The finest serpentines of Spain are from 
 Sierra-Nevada, two leagues from Grenada : they 
 have a green base, filled with glistening plates, 
 of a yellowish colour. Superb columns have 
 been made from it, which decorate the churches 
 and palaces of Madrid. 
 
 <c It is almost entirely wanting in northern 
 Asia, with the exception of the eastern part of 
 the Ural mountains, which separate Siberia 
 from Europe. There are some hills which, at 
 
MODE VI. SERPENTINE. 339 
 
 great intervals, accompany their base, following 
 their direction from north to south. There are 
 even some detached branches, which appeal- 
 near Tobolsk, which is not far from those moun- 
 tains. 
 
 " But from thence to the river Amur, that is 
 to say, in a space of about a thousand leagues, 
 scarcely any vestiges are found, in the great 
 chains of Altai, Sayannes, and in the mountains 
 of Daouria. 
 
 " The serpentines most known are those of 
 Sahlberg, in Sweden, and of Zeoblitz, in Saxony, 
 from which vases are turned of every kind, which 
 are spread over Europe *. 
 
 <c The serpentine of Bareith is filled with gar- 
 nets of an irregular form, generally of the size of 
 a pea: they are sprinkled in an equal manner 
 in the mass, and when the stone is polished it 
 presents a very agreeable mixture of spots, of a 
 fine red on a green base. Trinkets and other 
 ornaments are made of it. 
 
 " Saussure has observed several serpentines, in 
 rolled blocks, on the shores of the lake of Ge- 
 neva : they are remarkable by their specific gra- 
 vity, which is greater than that of all other ser- 
 pentines. He saw some soft, and some hard. 
 
 * It is commonly an ollite. 
 Z 2 
 
340 DOMAIN IV. TALCOUS. 
 
 The softest is foliated, and its specific weight 
 exceeds 3000, which is the weight of oriental 
 jad. It is this softest variety which the best 
 resists the action of fire. 
 
 (f Some of the blocks found in the valley of 
 Chamouni present a green serpentine, marbled 
 with white, like the serpentine of Saxony ; others, 
 - a green serpentine also, but mixed with shining 
 plates of green talc, threads of asbestos, and of 
 brilliant and golden amianthus, with laminar 
 crystals in the form of flattened parallelepipeds. 
 These crystals have neither the hardness of 
 schorl, nor the characteristics of hornblende; 
 they melt into a white amel, while hornblende 
 always gives a black glass. The plates of green 
 talc are infusible; and the serpentine which 
 constitutes the base of the stone melts, in bub- 
 bling and emitting little sparks. 
 
 " These fragments proceed from some hills, or 
 considerable masses, which have been destroyed 
 by time. Saussure saw, near Chiavenna, in the 
 country of the Grisons, entire mountains of ser- 
 pentine and ollite, which were only heaps of in- 
 coherent blocks. 
 
 " The summit of the mountain of Garda, near 
 Genoa, is composed of a serpentine, which Saus- 
 sure has called granular : it is of a deep grey 
 green, with unequal fracture, dull, earthy, af- 
 
MODE VI. SERPENTINE. 34 \ 
 
 fording an argillaceous smell, and melting under 
 the blow-pipe into a black glass. Its exterior 
 is covered with a coat of rust. 
 
 " The observation of the characters of this 
 rock is important, as it shows the transition of 
 serpentines to corneennes. It is absolutely mid- 
 way between these two sorts of rocks. 
 
 cc The beds of this serpentine alternate in the 
 mountain with beds of calcareous, quartzy, and 
 micaceous schistus ; and with beds of primitive 
 slate. 
 
 " The mountain called Roth Horn, or Red Roth Horn - 
 Horn, and which faces Mount Rosa, towards 
 Italy, is elevated 1506 fathoms: it is composed 
 of compact serpentine, divided into irregular 
 masses of an immense size. The surface of this 
 serpentine becomes red by the action of the 
 atmosphere, which oxyginates the iron it con- 
 tains to the highest degree. It is this colour, 
 and the elongated form of this mountain, which 
 have procured it the name of the Red Horn. 
 
 c< This serpentine is covered by a steatite, of 
 a sea-green colour, mixed with carbonate of 
 lime, and grains of felspar. On this steatite 
 beds of calcareous micaceous schistus repose, in 
 which the mica contained is more than one half. 
 These schisti are again covered by serpentine : 
 all the beds are nearly horizontal, a little raised 
 
342 DOMAIN IV. TALCOUS. 
 
 towards Mount Rosa. Geologists will perceive 
 the importance of this observation. 
 
 " Mount' Cervin, another mountain near 
 Mount Rosa, is an inaccessible obelisk, of a tri- 
 angular form, which is elevated to the prodigious 
 height of 2309 fathoms above the sea, according 
 to the trigonometrical measurement, taken with 
 the greatest exactness, by Saussure. It is com- 
 posed of three distinct masses, piled the one on 
 the other. 
 
 " That which forms the summit is of a yellow 
 Isabella colour. It is composed of serpentine, 
 mixed with micaceous schistus, calcareous, and 
 quartzy. Saussure has thus judged of its con- 
 struction from other neighbouring summits, 
 which he has visited, and which present exactly 
 the same colour. 
 
 " The mass which is under this is of a grey 
 colour, and formed of gneiss and quartzy mica- 
 ceous schistus. Saussure saw some of its frag- 
 ments. 
 
 " The third exactly resembles the first ; and 
 Saussure found that it is also of serpentine, al- 
 ternating with calcareous micaceous schistus. 
 
 " The base of the pyramid is of serpentine, 
 but of a confused structure. 
 
 <c I repeat, that mountains of serpentine are 
 seldom of a great elevation; and that those 
 
MODE VI. SERPENTINE. 343 
 
 about Mount Rosa are owing to a peculiar and 
 local circumstance. 
 
 " One of the most remarkable hills of serpen- Magnetic 
 
 Dill* 
 
 tine, on account of the phenomena which it pre- 
 sents, is that observed by Humboldt, in 1793, in 
 the chain of mountains which separates the mar- 
 graviate of Bareith from the Upper Palatinate. 
 
 " This hill is only elevated fifty fathoms above 
 the neighbouring plains: it extends in length 
 from east to west, its skirts consequently are to 
 the north and south. 
 
 " The rocks which crown its summit are of a 
 very pure serpentine, which, by its colour and 
 foliated fracture, approaches schistose chlorite. 
 It is divided into tolerably distinct beds, and re- 
 poses on a veined granite, mixed with horn- 
 blende. 
 
 " Humboldt having brought his compass near 
 these rocks of serpentine, saw with surprise, that 
 the north pole flew round quickly to the south. 
 He farther observed, that the rocks of the north 
 declivity, and those of the southern, have their 
 poles directly contrary. In the former are only 
 found south poles, and in the latter north poles. 
 The eastern and western extremities of the hill 
 are in a state of indifference, and do not mani- 
 fest any action on the magnetic needle, though 
 otherwise the rock affords the same appearance. 
 
344 DOMAIN IV. TALCOUS. 
 
 " In the magnetic parts of this hill certain 
 rocks are also observed, which have no action, 
 by the side of similar rocks, which have a very 
 strong one. Some affect the needle at the dis- 
 tance of 22 feet. 
 
 " Thi^ mountain not only exerts its action on 
 the magnetic needle in its whole mass, like some 
 other mountains, but it is manifest in even very 
 small pieces. Humboldt has observed, that frag- 
 ments, scarcely visible, are briskly moved, upon 
 presenting to them, one after the other, the poles 
 of the weakest magnet: and it is remarkable, 
 that a substance possessing such a decided po- 
 larity, has not the least attraction on iron not 
 magnetised. 
 
 " Humboldt convinced himself that this ser- 
 pentine does not contain an atom of magnetic 
 iron ; all which it contains, and which colours 
 it, is in the state of oxyd. It is for naturalists 
 to explain the cause of so remarkable a pheno- 
 menon. 
 
 cc The specific gravity of this serpentine is 
 much less than that of others; it only extends 
 from 1 900 to 2000, while the ordinary weight 
 of this rock is 2700, and even reaches, as Saus- 
 sure has observed, tcr 3000, in certain varieties 
 which he found in the vicinity of the lake of 
 Geneva, 
 
MODE VI. SERPENTINE. 
 
 345 
 
 " M. Chenevix, the chemist, who has em- 
 ployed himself in a succession of analyses of 
 magnesian rocks, found that serpentine and ol- 
 lite are composed of the same elements; and 
 that, according to a medial sum of many ana- 
 lyses, they contain, silex 28, argil 23, magnesia 
 34, oxyd of iron 4, water 11."* 
 
 The name, serpentine seems to have been de- 
 rived from the Italians, who however applied it 
 in differently to several substances; as black 
 porphyry was called serpentino nero, and the 
 green porphyry serpentino antico^. The name, 
 which was vague at first, was afterwards con- 
 fined to this magnesian rock, to which it is most 
 strictly applicable, from the variegation and 
 unctuous appearance of the colours. 
 
 Ferber has minutely described several of the 
 Italian serpentines, particularly that of Impru- 
 neta, near Florence. The colours are white, 
 red, black, yellow, and green ; sometimes uni- 
 form, sometimes intermingled. It is often inter- 
 sected by small veins of asbestos, and sprinkled 
 with an unctuous micarel, of a greenish silvery 
 
 * Patrin Min. i. 177. 
 
 t Wall. i. 432. It is singular that this truly learned author 
 should have followed the common error concerning the ophites of 
 Pliny. 
 
 Name. 
 
 Italian. 
 
346 
 
 DOMAIN IV. TALCOUS. 
 
 Useful in 
 the arts. 
 
 Nephritic 
 stone. 
 
 hue, of a square form, and not hexagonal, like 
 mica. There are also perpendicular veins, from 
 six to twelve inches in breadth, containing the 
 following substances: 1. Farinaceous steatite, 
 or soap earth, white and green. 2. Chalk of 
 Brianon. 3. Fibrous steatite, passing to as- 
 bestos. 4. Asbestos. 5. White and green ami- 
 anthus. As he wrote in 1772, in the mere dawn 
 of genuine mineralogy, his names are modified 
 by his descriptions. 
 
 As serpentine, like ollite, resists fire, it would 
 be found of far more utility in domestic and pub- 
 lic monuments than marble; yet its use has 
 been unaccountably neglected, both in ancient 
 and modern times. The beautiful serpentines 
 of Portsoy, the singular white- veined marbles of 
 Durness, and the most elegant of all the marbles, 
 that of Tirey, with the fine green serpentine 
 marble of Anglesea, might supply the British 
 empire with decorations far exceeding the fa- 
 shionable imports from Italy, the insipid marbles 
 of Carrara and Sienna, especially at a period 
 when we should only enrich our enemies. 
 
 Serpentine, like the other magnesian rocks, 
 impressed the ancients not irrationally with an 
 idea of medical qualities. Internally they would 
 act as absorbents; but the nephritic stone was 
 
MODE VI. SERPENTINE. 
 
 supposed, when only worn, to cure diseases of 
 the reins, or the lumbago*. This nephritic 
 stone is often found in flat pebbles on the shores 
 of the sacred island Hyona, among the Hebudes 
 of Scotland. It approaches to what is called 
 jad, the giada of the Italians, and is also found Jad. 
 in the island itself, adjacent to fine white mar- 
 ble. As jad however has never been yet ob- 
 served to constitute a rock, but, according to 
 the imperfect observations, has only been found 
 in rivers in schistose fragments, whence it would 
 seem only to form thin layers, it has not been 
 admitted into the present work. It must also 
 be observed, that the analyses hitherto given of 
 this substance are not satisfactory. The jad, 
 which forms the base of the composite rock 
 called the Corsican green, has been pronounced 
 by Werner to be a felsite, or compact felspar ; 
 and if the analysis of the younger Saussure be 
 trusted, it contains no magnesia. It may seem 
 to be nearly the same substance with the iconite 
 of the Chinese, only in a far higher state of in- 
 duration. This substance has also, by some 
 writers, been called lemanite, from the Lacus 
 Lemanus, or Leman Lake, now called the Lake 
 
 * According to others, the stone, or gravel j in which sense it is 
 used by modern physicians. See Johnson. 
 
348 DOMAIN IV. TALCOUS. 
 
 of Geneva, upon whose shores it was found by 
 Saussure. 
 
 Werner and his disciples have continued the 
 ancient name of nephrite to jad, which they 
 class among the magnesian rocks ; and they di- 
 vide it into two sub-species ; the oriental, which 
 is brought from China and the East*, and what 
 they call beilstein, or axe-stone, because it is 
 brought in the form of axes from South Ame- 
 rica, whence it might strictly be called occi- 
 dental. It is to be regretted that no able che- 
 mist, no Klaproth nor Vauquelin, has analysed 
 the various kinds of jad, though a stone of cele- 
 brated beauty and utility ; and it remains un- 
 certain, whether it ought to be referred to the 
 magnesian, the argillaceous, or whether it may 
 , not even be an unctuous keralite, resembling 
 unctuous quartz. It may perhaps even be of 
 various kinds and compositions, afterwards to 
 be distinguished by new appellations. Recent 
 French writers have called it felspath compact 
 jadien-\ y which, they add, is the jad of the lapi- 
 
 * Wad, p. 23, mentions different monuments of nephrite, among 
 which one of a leek green, which, he adds, is giada, and is marked 
 with Persepolitan characters. Roziere brought from Egypt a frag- 
 ment of red granite, marked with the same letters, from a monu- 
 ment which, if I remember right, he discovered in the Desert of Suez. 
 
 f Brard, 166. 
 
MODE VI. SERPENTINE. 
 
 daries, and the nephrite of the Germans ; only 
 different from other compact felspar by its tena- 
 city, weight, and unctuous appearance, while it 
 melts under the blow-pipe like other felspars. 
 The able and ingenious Haiiy has added the 
 lemanite, or white jad, as an appendix to fel- 
 spar, under the name offelspath tcnace ; while 
 he ranks jad, the nephrite of Werner, among the 
 substances whose characters are not sufficiently 
 known to find a place in the system. He re- 
 gards the axe-stone as totally different from the 
 oriental jad, of which he gives two analyses, one 
 by the younger Saussure, who found iron, man- 
 ganese, soda, pot- ash, &c. &c. and has acquired 
 little reputation as a chemist. Karsten, in his 
 tables of mineralogy, Berlin 1808, has given 
 another, by Kastner, which is probably authen- 
 tic, and deserves repetition ; silex 50, magnesia 
 31, argil 10, water 3, oxyd of iron 5, with a tint 
 of chrome. 
 
 Mineralogists having in general supposed that 
 jad or nephrite occurs in veins or layers in ser- 
 pentine rocks, it was proper some account should 
 be given of so remarkable a substance. For the 
 same reason, it may be proper here to mention 
 asbestos and amianthus, almost constant in the Asbestos. 
 midst of serpentine, but which cannot be regarded 
 as forming rocks. The 1 ate ingenious Dr. Walker, 
 
350 DOMAIN IV. TALCOUS. 
 
 professor of mineralogy in the University of 
 Edinburgh, who repeatedly visited the Western 
 Isles of Scotland, is said to have asserted, that 
 the little isle of Bernera, which terminates the 
 exterior chain of the Hebudes, is composed of 
 amianthus, or, as he more probably intended, a 
 mixture of asbestos and amianthus. Lord Sea- 
 forth, the excellent proprietor of these remote 
 regions, and himself a mineralogist, when con- 
 sulted by the author, answered, that so singular 
 a circumstance was unknown to him, though it 
 could scarcely have escaped his information. 
 The finest amianthus occurs in Corsica, forming 
 beautiful white silky threads, of two feet or more 
 in length ; and it is so abundant, that Dolomieu 
 used it instead of flax to pack his minerals. 
 There is also a mountain in the Uralian chain 
 which is called the Silky Mountain, as in the fis- 
 sures of a Saussurite or magnesian basaltin there 
 is found an amianthus, which at first appears 
 compact and hard, but when exposed to the air 
 for some months, it swells, and becomes a fine 
 down, as flexible as cotton*. But even this can 
 scarcely be said to form a constituent part of 
 the mountain, and amianthus on a smaller scale 
 is frequent in rocks of this description -, so that 
 
 * Patrin, i. 216. 
 
MODE VI. SERPENTINE. 351 
 
 it must continue to be regarded as a parasitic 
 substance : and if even a rock or hill consisting 
 solely of asbestos and amianthus were discover- 
 ed, it must be classed among the anomalous, as 
 being contrary to the usual course of nature. 
 
 Having thus discussed the chief parasitic sub- 
 stances which are found in serpentine, it is pro- 
 per to return to the immediate consideration of 
 that celebrated rock. 
 
 Werner and his disciples divide it into two of 
 their barbarous sub-species, under the epithets 
 Common and Noble; the latter being trans- se ,entine. 
 parent, and chiefly found in Silesia. It is gene- 
 rally of a dark leek green, and of an unctuous 
 visage. Mr. Jameson says that in Italy it is 
 called nephrite, with which it might perhaps be 
 classed. But when Brochant supposes that the 
 verde antico, and other green marbles well known 
 in Italy, belong to the noble serpentine, he for- 
 gets that they are all opake, while the latter is 
 translucent. When he quotes Estner, who con- 
 founds the verde antico and ophite with green 
 porphyry, the confusion is infinite; for the verde 
 antico is a marble, which will presently be de- 
 scribed ; and the ophites, as already shown, is a 
 mere error, echoed by mineralogists for a cen- 
 tury and a half, while the ophites of Pliny is an 
 ollite. The noble serpentine of Werner, which 
 
352 DOMAIN IV. TALCOUS. 
 
 is found in small masses or disseminated, seems 
 rather to belong to lithology or gemmology. 
 
 STRUCTURE I. ENTIRE. 
 
 Black serpentine, from Egypt. 
 
 Brownish serpentine, from the same. These 
 are small statues, described by Wad. 
 
 Serpentine, with white spots, from Cecina, near 
 Volterra, Tuscany. 
 
 Black, from Monte Ferrato-di-Prato, call Nero- 
 di-Prato. 
 
 Green, from the same, Verde-di-Prato. 
 
 Gabbro, or serpentine of various colours, from 
 Impruneta, seven miles south from Florence. 
 
 Green serpentine, with yellow spots, from the 
 Sierra Nevada, in Spain. 
 
 Serpentine, shaded with various tints of green, 
 from the Pyrenees*. 
 
 Deep green magnetic serpentine, from Bareuth. 
 
 Green serpentine, marbled with white, from the 
 Vale of Chamouni. 
 
 Serpentines, from Corsica and Italy. 
 
 * The erroneous ophite of Palassou, whose work on the Pyre- 
 nees has great merit. See his prolix dissertation on this pretended 
 ophite, Journ. des Mines, v. 31. He is however nearer the truth 
 than Gesner, and his successors, who supposed ophite to be green 
 porphyry. 
 
MODS VI. SERPENTINE. 
 
 Brown serpentine, spotted with red, from the 
 Lizard point. 
 
 Dark green serpentine, from the same : perhaps 
 the name of the cape is derived from the colour. 
 
 Serpentine, of various colours, from Portsoy. 
 
 Yellowish serpentine, from Zoblitz, in Saxony. 
 
 Black serpentine, spotted with red, from the 
 same. 
 
 Green serpentine, in pebbles, from the Lake of 
 Geneva. 
 
 Granular serpentine, from the Alps. 
 
 Serpentine, from the mountain of Cervin, 
 
 STRUCTURE II. MINGLED. 
 
 With mica, from the Lizard point, Sec. 
 
 With veins of steatite, from Cornwall, Portsoy. 
 
 With aabestos, from the same. 
 
 With amianthus, from Zoblitz. 
 
 With foliated steatite, amianthus, and garnets, 
 from the same. 
 
 With garnets, from Bohemia. 
 
 With asbestos and calcareous spar, from Pratou 
 
 With spangles of satiny diallage, the smaragdite 
 of Saussure, from Impruneta. 
 
 With metallic diallage, from Saxony. 
 
 With the same and epidote, from Queyras, near 
 Bnanon. 
 
 VOL. i. 2 A 
 
 I 
 
354 DOMAIN IV. TALCOUS. 
 
 'Saussure presents some uncommon examples : 
 
 Serpentine, with spots approaching to crystal- 
 lisation : may not this be the stone mentioned by 
 Pliny as gemmose? 107- 
 
 Laminar serpentine, of a yellowish grey, with 
 striated surfaces, and translucent on the edges. 
 2253. 
 
 He also describes, 1434, another granular ser- 
 pentine, with an earthy fracture. 
 
 Mount Cervin rises to a prodigious height, un- 
 der the form of a triangular obelisk of bare rock, 
 which seems hewn with a chisel : the appearance 
 is alike singular and magnificent. Saussure, 
 2220, gives a curious account of this surprising 
 mountain of serpentine. 
 
 MODE VII. SAUSSURITE. 
 
 Characters. Texture, fine-grained, compact. 
 
 Hardness, basaltic. Fracture, generally even 
 and earthy, sometimes scaly. Fragments, amor- 
 phous, rather blunt. 
 
 Weight, granitose. 
 
 Lustre, dull, sometimes rather glimmering, 
 from particles of siderite. Opake. 
 
 Colour, black or dark grey, sometimes faintly 
 
MODE VII. SAUSSURITB. 355 
 
 verging towards the green, from an excess of 
 magnesia. 
 
 This stone may be regarded as intermediate 
 between basaltin and serpentine, and might be 
 called magnesian basaltin ; but as it is the most 
 remarkable pier re dc corns of Saussure, it has 
 been thought proper to give the name of that 
 great observer to this important rock. 
 
 The pierre de corne* or corneenne, is a vague 
 appellation, still retained by the French mine- 
 ralogists. It sometimes implies a trap, some- 
 times a wacken, sometimes an earthy siderite ; 
 and sometimes more appropriately the present 
 rock. Saussure has observed, 1225, that when 
 the corneenne appears crystallised, it assumes 
 the name of hornblende. He has given, 725, 
 an analysis of his pierre de corne, and observes, 
 that the chief difference between it and basalt 
 is the mixture of magnesia. In Kennedy's ac- 
 curate analysis of basalt there is no trace of 
 magnesia ; but in the Saussurite there ought to 
 be more than 6 in the 100. The decomposition 
 of the iron often forms a kind of bark around 
 this stone, whence it has been called by some 
 authors pierre-a-ecorce. 
 
 Dolomieu, in his celebrated memoir on felsite 
 and trap, which precedes his distribution of vol- 
 canic products, observes, that the cavities in 
 
 2 A 2 
 
DOMAIN IV. TALCOtfS. 
 
 trap are commonly filled with calcareous spar; 
 while those of his rocke-de-carne, or Saussurite, 
 besides calcareous spar, often present a green 
 with steatite, steatite extremely ferruginous*. This feature, 
 with the occurrence of amianthus, and other 
 modes of talc, confirms the magnesian propen- 
 sity of this rock ; and as these green nodules 
 are also frequent in amygdalite, it is to be sus- 
 pected that the latter, to the base of which va- 
 rious denominations have been assigned, may, 
 when duly analysed, be found to belong to this 
 division. 
 
 Dolomieu also considers the chlorite slate of 
 Werner, which often presents octahedral crystals 
 of iron, as intermediate, between the roche dc 
 come and the talcs ; while the former graduates? 
 from trap to serpentine. 
 
 " In Tuscany there are frequent examples of 
 these passages of rochc de come to serpentine. 
 At Pietra Mala, on the ridge of the Apennines, 
 to the right of the road from Bologna to Flo- 
 rence, there is a mountain which presents all 
 the kinds of gradations between serpentine and 
 roche de corne, and the passage of the earthy 
 grain of this to the scaly texture of hornblende, 
 or corneus spathosus. This roche de corne, of a 
 
 * Journal de Physique, 17Q4, p. 258. 
 
MODE VII. SAUSSURITE. 357 
 
 black base, marked with white and green spots, 
 has been taken for a lava by many naturalists, 
 among others by Mr. Ferber."* 
 
 That the cornienne is a term which ought to 
 be dismissed from mineralogy, will sufficiently 
 appear from the following description, by Brong- 
 niart, a very industrious and exact mineralogist. 
 
 " Corn&nne^ is a rock very difficult to deter- 
 mine, and still more difficult to confine to pre- 
 cise limits. On one side it approaches very 
 near to wacken, and on the other to argillaceous 
 schistus : it has besides numerous relations with 
 basalt, and even with amphibolc, or hornblende. 
 
 " This rock is generally compact and solid ; 
 its fracture is dull, rather even, but irregular; it 
 yields by breathing on it a very sensible argil- 
 laceous odour; it is generally difficult to break, 
 causing the hammer to rebound, and presenting 
 a kind of tenacity, which throws it at a distance 
 from wacken, and approaches basalt. It often 
 
 * Journal de Physique, 1794, p. 258. 
 
 " f Corneus. Wall. This genus contains the greater part of our 
 tmphibole hornblendes. Corne'enne rock, Haiiyj omitting the va- 
 rieties 2, 3, and 4 vulgarly pierre de come. 
 
 <( This species must not be confounded with the hornstein of the 
 German mineralogists: it has been seen that this was a silex. 
 Corneenne must also be distinguished from the roche de corne of 
 Saussure, which seems to be a trap rock, in the acceptation that we 
 give to that word, according to Mr. Werner." 
 
358 DOMAIN IV. TALCOUS. 
 
 possesses sufficient tenacity not to be scratched 
 by the copper knife, which, on the contrary, 
 leaves its mark. It is even difficult sometimes 
 to be scratched with iron. 
 
 " Corneenne is easily melted into a black 
 bright amel, and this character distinguishes it 
 from schistus, when it possesses the texture of it, 
 and from schistose jasper, when it approaches it 
 by its hardness : it almost always acts upon the 
 magnetic needle. 
 
 " Most mineralogists look upon this rock as 
 an intimate and invisible mixture of amphibole* 
 and clay. 
 
 cc We shall establish the following varieties in 
 this species : 
 
 <c 1. Compact Corneenne. It is solid, com- 
 pact, difficult to break ; its fracture is uneven, 
 passing to the conchoidal. 
 
 " I will give, as an example of this variety, 
 the brown paste, approaching to the violet, of 
 the amygdaloids of Drac. Dolomieu considered 
 it as a corneenne well characterised. The paste 
 of the amygdaloids of Derbyshire, called toad- 
 stone, should be equally placed with it, and that 
 of the agates of Oberstein, &c. 
 
 * An absurd name for hornblende or siderite, signifying forsooth 
 emliguous, while there is no substance less ambiguous. P. 
 
MODE VII. SAI7SSUEITE. 359 
 
 " 2. Trap Cornfenne*. This variety is hard; 
 it wears iron, but does not sparkle ; it is com- 
 pact ; its grain is consequently fine, close, and 
 absolutely dull. This is what distinguishes trap 
 from basalt; the latter always showing in its 
 fracture a grain rather crystalline. It breaks in 
 parallelepipeds : its fracture is sometimes con- 
 choidal. Its most general colour is black, but 
 there is some, bluish, greenish, and reddish. 
 (Wall.) 
 
 " The trap here mentioned is an homogenous 
 rock. It is easily distinguished by its charac- 
 ters from the trapose rocks. 
 . u This rock is very common in several parts 
 of Sweden. 
 
 <c 3. Lydian Corneenne^. This corn&enne is 
 black, dull, compact ; it is softer than the trap, 
 or cornienne, and has not the parallelopided frac- 
 ture : it is, on the contrary, perfectly compact, 
 and sometimes rather schistose : it is scratched 
 not only by iron, but also by copper, when the 
 angle or edge of a piece of copper is applied; 
 but when this rock is rubbed with the flat or 
 
 
 
 " * Corneus trapezius. Wall. Trap is a Swedish word, which 
 means stairs. This name has been giveivto this corneenne, because 
 the mountains which it forms present a kind of steps or seats in 
 their declivities." (Wall.) 
 
 ** f Corneus trapezius. Lapis Lydms" (Wall.) 
 
3(50 UOMAIN IV. TALCOUSi 
 
 rounded part of a copper instrument, it receives 
 the mark of the metal. It is by these characters 
 that it is distinguished from the blackest and 
 most compact argillaceous schisti; they being 
 always scratched by copper^ and never receiving 
 any mark from it, however applied; besides, 
 schisti do not melt like corn&enne. 
 
 " It is on the property, which the Lydian 
 corneenne possesses, of receiving the mark of cer- 
 tain metals, that the use that is made of this 
 Stone, to judge by sight of the quality of gold, 
 is founded. It is vulgarly called touch-stone*. 
 It has also the name of Lydian, because the 
 ancients gave that name to touch-stone; but it 
 no longer comes from Lydia. Those at present 
 used come from Bohemia, Saxony, and Silesia. 
 I dare not however affirm that the touch- stones 
 of those countries are all related to this variety 
 of corn&enne. It is even probable that the 
 greater part among them are basalts. 
 
 <( The Lydian cornfemie, of which we are here 
 treating, is that used as a touch-stone among 
 
 (f * Touch-stones, and the manner of using them, will be spoken 
 of more in detail in treating of the uses of gold. It is probable that 
 different kinds of stones are used as touch-stones, schistus, schistose 
 jaspers, and perhaps even basalts. Wallerius thought he distin- 
 guished three kinds of touch-stones, which he referred to three kinds 
 of rocks, basalt, schistus, and corntenne" 
 
MOJDE VJI. SAUSSURIXJE. 
 
 the goldsmiths and assayers of Paris. I have 
 seen no other sort among them. It is so much 
 the better, as it is blacker, and more compact. 
 It is certainly , properly speaking, neither a ba- 
 salt nor a schistose jasper. It is said to come 
 from Germany, by the way of Nuremberg : but 
 those who sell them know nothing more of it. 
 
 " Corneenne belongs either to primitive or 
 transitive earths. It never contains organised 
 fossile bodies. Sometimes it forms thick beds, 
 sometimes it presents itself in masses, in which 
 the stratification is not perceptible. It consti- 
 tutes in this instance the base of certain amyg- 
 daloids, or glandular rocks."* 
 
 Brochant is equally perplexed. The corne- 
 enne y he says, is sometimes siliceous schistus, 
 sometimes Lydian stone, sometimes the clay- 
 slate of Werner, hornblende slate, wacken, trap. 
 An appellation so vague ought to be finally dis- 
 missed. The other pierres de corne of the French 
 will be found in their proper divisions ; but as 
 that analysed by Saussure himself contained 
 magnesia, which rarely occurs in the stones 
 above mentioned, it is proper to confine his 
 illustrious name to the present division, which 
 has scarcely attracted the notice of-mineralo- 
 
 * Brongniart, i. 560, 
 
DOMAIN IV. TALCOUS. 
 
 gists. Mr. Kirwan has indeed observed, that 
 serpentine is sometimes intimately mixed with 
 hornblende, or trap, in which case it is black. 
 It may in that case be regarded as a transition 
 from serpentine to Saussurite; and the connec- 
 tion between trap and serpentine has been al- 
 ready observed by Werner. 
 
 Saussurite, in rolled pebbles, from the lake of 
 Geneva. 
 
 The same, from the Alps. 
 
 Saussurite, with nodules of steatite, from the 
 western isles of Scotland. 
 
 With veins of amianthus, from the Pyrenees. 
 
 This substance is common in Saussurite, and 
 evinces its magnesian nature. 
 
 MODE VIII. GREEN GRANITEL. 
 
 A genuine green granite, found among the 
 ancient monuments of Egypt, has already been 
 described in the account of that rock ; but that 
 beautiful substance is so extremely rare, that it 
 cannot interfere with the present object. The 
 Egyptian is composed of quartz, mica, and an 
 emerald green felspar; while the green granitel 
 here implied seems a mixture of felspar and si- 
 derite with steatite, the magnesia having even 
 
MODE IX. MAGNESIAS LIMESTONE. 
 
 penetrated the felspar, and imparted its usual 
 green colour, whence it has received its common 
 appellation. 
 
 It is found in the Vosges mountains in France, 
 and there is a manufactory at Paris, where it is 
 cut into tables, vases, chimney-pieces, and other 
 articles of decoration. 
 
 The fracture has the soft unctuous appear- 
 ance of a magnesian rock, and the obscure green 
 colour is a further characteristic of that class of 
 stones, so that there seems little doubt but it 
 must belong to this Domain. 
 
 Similar granitels are found, it is believed, in 
 Westmoreland, and in Ireland. Occasionally 
 some crystals of the felspar are large and regu- 
 lar, when it assumes the form of a porphyry. 
 
 MODE IX. MAGNESIAN LIMESTONE. 
 
 Many limestones are so much impregnated 
 with magnesia, that their qualities become al- 
 tered, and they are injurious to vegetation. 
 According to Dr. Kidd, the limestone of parts 
 of Derbyshire, Nottinghamshire, and Yorkshire, 
 is of this kind; and at Matlock the limestone 
 of the rocks on the side of the river where the 
 houses are built is magnesian; on the other 
 
DOMAIN IV. TALCOUS. 
 
 pure. Mr. Tennant has analysed the stone em- 
 ployed in two remarkable ancient buildings. 
 
 " STONE OF YORK 
 MINSTER. 
 
 Carbonic acid . 47,00 
 
 Lime 33,24 
 
 Magnesia . . . 19,36 
 Iron and clay . 0,40 
 
 100,00 
 
 " STONE OF WESTMIN- 
 STER HALL.. 
 
 Carbonic acid . 47,16 
 
 Lime 33,48 
 
 Magnesia . . . 17,76 
 Iron and clay . 1,60 
 
 100,00" 
 
 But the most remarkable stone of this kind is 
 Dolomite. Dolomite, resembling a primitive granular lime- 
 stone, but which, according to many analyses, 
 contains not less than 45 of magnesia, in the 
 form of carbonate. This stone received its name 
 from Dolomieu, who observed it among the 
 remains of ancient sculpture at Rome; arid after- 
 wards discovered it in the mountains of Tyrol. 
 It has been classed among the primitive mar- 
 bles; but the essential difference is, that the in- 
 fluence of the magnesia prevents its effervescence 
 with acids, unless previously pulverised, when 
 the calcareous particles are affected by the ex- 
 posure. It is also sometimes phosphorescent 
 when scraped in the dark, and elastic in thin 
 plates. It sometimes contains veins of green 
 mica, like the primitive marble called Cipolino. 
 In appearance it differs but little from granular 
 
MODE IX. MAGNESIAN LIMESTONE. 
 
 limestone. The Apollo of Belvidere, and some 
 other beautiful statues, are said to be formed of 
 Dolomite. 
 
 Dolomite forms arrects, or uprights, extend- 
 ing from the base to the summit of the Alps of 
 Tyrol ; whence it has become a proverb in the 
 country, that no mountain exists without a hat 
 of limestone*. It is sometimes in large masses, 
 sometimes in thin layers, alternating with foli- 
 aceous mica. Saussure, 1929, observes, that 
 most of the primitive limestones of St. Gothard 
 are Dolomites ; and they often contain the para- 
 sitic substance called tremolite. 
 
 STRUCTURE I. MAGNESIAN LIMESTONE. 
 
 From the North of England, and various other 
 countries. 
 
 STRUCTURE II. DOLOMITE. 
 
 Aspect 1. Entire. From the ruins of Rome. 
 From the Alps of Tyrol. 
 
 Aspect 2. Mingled. From St. Gothard, with 
 tremolite. 
 The same, elastic, with foliaceous mica. 
 
 * Patrin, ii. 309, 
 
DOMAIN IV. TALCOUS, 
 
 MODE X. GREEN MARBLE. 
 
 In most rocks the green colour betrays the 
 presence of magnesia, whence it becomes an 
 emphatic epithet. In the magnesian limestone 
 this effect is not observable, because the minute 
 talcous particles are intimately combined with 
 the calcareous ; but where they are aggregated 
 apart, as in the green granitel and green marble, 
 the colour becomes characteristic. The latter 
 is also called sometimes serpentine marble, be- 
 cause in fact the green parts belong to the rock 
 called serpentine, while the white are purely 
 calcareous. These marbles have never been 
 classed with glutenites, being neither bricias nor 
 pudding-stones, but an irregular and original 
 compound of serpentine and marble, in which 
 the former is preponderant. 
 
 The most celebrated rock of this description 
 is that called the verde-antico, or ancient green, 
 in which a green serpentine with dark spots, 
 seemingly rather argillaceous, is interspersed 
 with a pure white marble. This is the Laconian 
 marble of the ancients, of which there were 
 quarries near Mount Taygetus; and Pliny has 
 rightly characterised it as more cheerful than, 
 
MODE X. GREEN MARBLE. 
 
 any other. But the whole passage again de- 
 serves attention : " Some marbles are esteemed 
 VERY PRECIOUS, as the Lacedemonian green, 
 more cheerful than all the rest. So ALSO the 
 Augustean, and afterwards the Tiberian, first 
 discovered in Egypt in the reigns of Augustus 
 and Tiberius. The difference between them and 
 ophites is, that the latter is spotted like a ser- 
 pent, whence it received the name; while the 
 others present spots of a different form, the 
 Augustean being crisped into wavy spots, while 
 in the Tiberian the white (canities) is scattered, 
 not convolved." 
 
 Such is this celebrated passage, which has led 
 to many errors in mineralogy, as it has been 
 conceived that the ophites was green porphyry, 
 and that the other kinds were green ; whereas it 
 is clear from the subsequent part of Pliny's de- 
 scription, that the ophites was grey or whitish, 
 being a spotted ollite, and when the spots, were 
 of golden mica it became the most esteemed 
 Lapis Thebaicus of the ancients. In like man- 
 ner the " sic, so the Augustean," only implies 
 that both were esteemed very precious, like the 
 Laconian, but not that they were of a green 
 colour*. 
 
 * For the ancient testimonies concerning the green marble of 
 Laconia, the reader is referred to the learned work of Blasius Gary- 
 
368 DOMAIN ir. TALCOUS. 
 
 A recent French author gives the following 
 account of the verde-antico; but he is certainly 
 mistaken when he regards it as a bricia. 
 
 " The verde-antico should be considered as a 
 kind of bricia, the paste of which is a mixture of 
 talc and limestone, and the fragments, of a 
 greenish black, are owing to serpentine more or 
 less pure. This marble is an aggregate of white 
 marble and green serpentine, reduced to angular 
 pieces, or blended in its paste, and giving to it a 
 green colour, more or less deep. 
 
 " The verde-antico marble of the finest quality 
 is that of which the paste is of a grass green* 
 and the black spots are of serpentine, of that 
 sort called noble serpentine. It should also be 
 sprinkled with white spots, which renders it 
 more gay than when they are wanting. 
 
 " This marble is much esteemed in commerce, 
 but lar^e pieces of a fine quality are seldom 
 found. Nevertheless there are four beautiful 
 columns in the Hall of Laocoon, in the Napo- 
 leon Museum ; but there are much finer ones at 
 Parma. 
 
 " It was known by the ancients under the 
 name of Spartanu?n, or Lacedtemonium ; and we 
 
 ophilus (Biagio Garofalo) De Marmorilus Antiquis. Traj. 1743, 
 4to. Some extracts may be found in the Appendix. See also the 
 account of the ancient marbles in Domain V. 
 
MODE X. GREEN MARBLE. 369 
 
 are informed it was dug in the environs of Thes- 
 salonica, in Macedonia, which at present forms 
 part of European Turkey*. 
 
 " This verde-antico, properly so called, must 
 not be confounded with the marbles known by 
 the names of vert~de-mer, or vert-d'Egypte. The 
 real verde-antico is a bricia, and never is mingled 
 with red spots, while those just mentioned are 
 veined marbles, mixed with a dull red substance 
 which gives them a brownish hue, not very 
 agreeable. Besides, it is one of those marbles 
 which decompose in the open air."f 
 
 This decomposition is rather a proof that the 
 darkest parts are of an argillaceous nature. Dr. 
 Kidd regards the genuine verde-antico, which 
 must be carefully distinguished from ancient 
 green porphyry, and from mere serpentine, as 
 " an irregular breccia, consisting of fragments 
 of dark grey compact limestone, black argilla- 
 ceous schistus, and white granular marble, im- 
 bedded in a species of serpentine, which here 
 and there is of a uniformly green colour, and a 
 considerable degree of transparency, very closely 
 resembling j ad, or compact talc. 
 
 ce The fragments of white marble are very sin- 
 gularly fringed, as it were, with a green sub- 
 
 * A gross mistake, antf glaring inconsistency, 
 t Brard, 333. 
 
 VOL. i. SB 
 
370 DOMAIN IV. TALCOUS. 
 
 stance, which, proceeding in the form of close 
 parallel fibres from every part of the edge, pene- 
 trates into each fragment to the extent of about 
 the tenth of an inch. 
 
 " This appearance is of difficult explanation; 
 because it seems that the penetration, being so 
 regular, and accommodated to the outline of the 
 fragment, must have taken place subsequently 
 to the formation of the breccia." 
 
 It is certain that different specimens of this 
 substance have great variations, as probably 
 they are from different quarries. In some the 
 pieces of clay-slate easily detach themselves 
 from the mass ; but in the finest fragments the 
 whole is so intimately blended together, and the 
 general appearance so different from that of a 
 bricia, that no artist nor antiquary has ever ap- 
 plied this name to the Spartan green. Parts of 
 the new quarry in the Isle of Anglesea perfectly 
 resemble the verde-antico ; but no one has sup- 
 posed that beautiful stone to be a bricia. The 
 polzevera of Genoa is in like manner a green 
 serpentine, with veins of white marble, but is 
 never classed among the bricias. 
 
 others, There is another ancient and very rare mar- 
 Antique. 
 
 ble, of a deep green, with little distant red and/ 
 
 black spots, and fragments of entrochi changed 
 into white marble. Another rare kind is called 
 
MODE X. GREEN MARBLE, 
 
 leek marble, being of a bright green, shaded 
 with a blackish green, so as to form long veins, 
 with a fracture in splinters like that of wood. 
 There is a table of it at the Hotel de la Mon- 
 noie, at Paris*. 
 
 Of modern green marbles, the polzevera, al- Modem. 
 
 Polzevera. 
 
 ready mentioned, is so called from a mountain 
 on the north of Genoa. This marble often pre- 
 sents red calcareous parts f, like that of Angle- 
 sea; but in the latter the red, and even the 
 white, seem so intimately combined with mag- 
 nesian particles, that they do not effervesce with 
 the nitrous acid, while in the verde-antico the 
 effervescence of the white parts is very strong. 
 The polzevera is common in ancient chimney- 
 pieces, both in France and England, for exam- 
 ple, in the British Museum. There is also a 
 green and white marble, found at Suza, in Pied- 
 mont. 
 
 The green marble of Campan, and other dis- ofCampan, 
 tricts of the Pyrenees, also consists of limestone 
 mixed with talc; but the structure is so singu- 
 lar, that it is classed among the Anomalous 
 Rocks. The Isle of Elba also presents a white 
 marble, veined with dark green; but the green 
 marbles of Florence seem strictly to belong to 
 
 * Brard, 335. 
 
 f* So our author, but the red seem serpentine. 
 
 2 B 2 
 
 
DOMAIN IV. TALCOUS. 
 
 serpentine, as probably does the bisachino of 
 Sicily. A green marble, resembling the verde- 
 anticoy is also found at Grenada, in Spain. 
 
 What is called at Paris marbre (TEcosse is a 
 serpentine, from Portsoy. But one of the most 
 beautiful green marbles yet discovered is that of 
 of Angiesea. Anglesea, which sometimes resembles the verde- 
 antico; in other parts is interlaced with rose- 
 coloured veins; and in others variegated with 
 red and green of dissimilar intensity. It would 
 appear, as already mentioned, that even the cal- 
 careous parts are much impregnated with mag- 
 nesia, or, in other words, are Dolomite. This 
 marble was long since described by Da Costa, 
 and latterly by Coquebert. 
 
 MODE XI. MAGNESIAN INTRITE. 
 
 i 
 
 Serpentine The chief rocks of this description hithert 
 observed, are what have been called pot-stone 
 and serpentine porphyries, the latter being found 
 near Florence. The base is of the usual colours 
 of these two substances, interspersed with larger 
 or smaller crystals of felspar. 
 
 Magnesian intrites also exist with crystals of 
 quartz, or calcareous spar. 
 
 To this Mode may be referred the following 
 rocks, described by Saussnre : 
 
MODE XII. MAGNESIAN GLUTENITE. 373. 
 
 A steatitic rock, with crystals of rose-co- 
 loured felspar. 154. 
 
 He describes, 1437, what he calls a serpen- 
 tine porphyry, but really an intrite with small 
 crystals of actinote. 
 
 A hard green serpentine, with spangles of a 
 brighter green, semi-transparent, and resembling 
 wax; being seemingly a secretion, or confused 
 crystallisation, of the purest parts of the stone. 
 May not the same remark be applied to porphy- 
 ries, &c. ? 959. 
 
 Steatite, crystallised in ollite, the crystals be- 
 ing laminar, and of a grey inclining to green. 
 1851. 
 
 MODE XII. MAGNESIAN GLUTENITE. 
 
 This Mode presents, as usual, two Structures, 
 the large and the small grained. 
 
 STRUCTURE I. LARGE-GRAINED. 
 
 A late ingenious writer gives the following ac- 
 count of two curious magnesian bricias, the latter 
 however being more strictly a pudding-stone. 
 
 " 1. Steatitic bricia of Corsica. This Hricia, 
 the steatitic base of which is of a reddish white, 
 contains fragments of the same substance, which 
 
 
374 DOMAIN IV. TALCOUS. 
 
 are angular, in general small, some of which are 
 of a blood red, and others of a grass green. This 
 k beautiful rock, which resembles in its paste the 
 rock called lard-stone, used by the Chinese, was 
 discovered by M. Rampasse in Corsica, in the 
 department of Golo. I could have wished to have 
 given it a more exact locality, on account that it 
 would be highly interesting to work this beautiful 
 steatitic bricia : but M. Rampasse constantly re- 
 fused it. 
 
 " 2. Steatitic bricia of Monte Nero. The 
 steatitic bricia of Monte Nero is found in the lit- 
 tle torrent of Orsara, in Liguria. Instead of a 
 base wholly talcous, like the preceding, it consists 
 of a calcareous base of a cherry red, with a gra- 
 nular and scaly fracture, and only its spots are 
 owing partly to pebbles of serpentine of a pista- 
 chio green, and partly to some globules of laminar 
 diallage. It sometimes happens that the spots of 
 serpentine are surrounded with white rings, which 
 farther relieves the richness of this beautiful bri- 
 cia, which was discovered by M. Viviani, a learned 
 mineralogist*. It is to be regretted that its site 
 is not yet known, it being only found in detached 
 masses, in the torrent of Orsara. "f 
 
 Mr. Kirwan mentions among the bricias the 
 
 " * Viviani, Voyage in the Apennines of Liguria, p. 16." 
 t Brard, 482. 
 
MODE XII. MAGNESIAN GLUTENITE. 375 
 
 telgsten of Cronstedt, consisting of indurated 
 steatite, mixed with micarel, or felspar, or schorl, 
 or tourmaline ; but this is rather a mingled mag- 
 nesian rock, as is the serpentine, interspersed with 
 quartz, mica, limestone, or garnets. 
 
 Some authors, as already stated, regard the 
 
 verde-antico as a bricia. 
 
 a: jpppp 
 
 STRUCTURE II. SMALL-GRAINED. 
 
 These have scarcely been observed *. 
 
 * Perhaps the rag-stone of Da Costa, p. 173, is of this kind, 
 being of a greenish grey, and of a talcous appearance. It is used as 
 a hone to give a fine edge. 
 
DOMAIN V, 
 
 CALCAREOUS, 
 
 
 CALCAREOUS EARTH. 
 
 THIS important substance is produced 
 by burning limestone, marble, or chalk; 
 and is commonly known by the name of 
 lime. The purest is yielded by calcareous 
 spar, or some white marbles. 
 
 Its taste is hot and acrid ; and it is inca- 
 pable of fusion, even by the burning-glass. 
 
DOMAIN V. CALCAREOUS. 377 
 
 It may however be fused when joined with 
 silex or clay. 
 
 Limestone is composed of lime and car- 
 bonic acid. Heat separates the latter, and 
 the lime is left pure. This acid is a spe- 
 cies of gas, formerly called fixed air, and 
 discovered by Dr. Black in 1756; an event 
 which formed a revolution in the history 
 of chemistry. Atmospheric air is composed 
 of about seventy-four parts in the hundred 
 of nitrogen, and twenty-six of oxygen: 
 but the latter varies; and there is com- 
 monly one in the hundred of carbonic acid 
 gas. Hence lime exposed to the air ab- 
 sorbs the carbonic acid, and may again 
 become a carbonate, or limestone. 
 
 In architecture, mortar is composed of 
 quick lime and sand; and when mixed 
 with a proportion of iron, or manganese, it 
 becomes extremely hard, even under water. 
 
 When combined with sulphuric acid, the 
 calcareous earth forms gypsum, or selenite, 
 which being burnt produces what is called 
 plaister of Paris. The alabaster of the mo- 
 derns commonly belongs to the same com- 
 
378 DOMAIN V. CALCAREOUS. 
 
 bination ; while that of the ancients is often 
 -a stalagmite, or secretion of common lime- 
 stone. With fluoric acid, calcareous earth 
 becomes fluor, or fluate of lime. 
 
 The greater proportion of limestone is 
 produced by the decomposition of marine 
 shells ; but the more ancient, which is crys- 
 tallised, and presents no trace of such re- 
 mains, is called primitive, being supposed 
 as ancient as any of the rocks. It is in 
 general easily distinguished from the other 
 substances by the nitrous acid, formerly 
 called aqua-fortis, which excites efferve- 
 scence; but when mixed with magnesia, or 
 much silex, this effect is slowly procured. 
 Nor do gypsum nor fluor effervesce. 
 
 To these observations, which are chiefly 
 extracted from Kirwan, Thomson, and Pa- 
 trin, it may be added that, in 1808, Mr. 
 Davy reduced lime to a metal, which had 
 the colour and lustre of silver, and burnt 
 with an intense white light into quick lime. 
 
 In some works of mineralogy the first 
 three Modes of this Domain, and even the 
 three succeeding, have been arranged as 
 
DOMAIN V. CALCAREOUS, 
 
 mere sub-species, or varieties of limestone. 
 Strict chemical analysis may probably dis- 
 cover a different proportion of ingredients, 
 as, for examples, more water of crystallisa- 
 tion in marble, and more or less silex or 
 argil ; and there is at any rate a difference 
 in the mode of combination. But the chief 
 use of any system being to assist the me- 
 mory, even the strict precision of terms 
 becomes mere pedantry, if it be not sub- 
 servient to this main object. Too large 
 masses of colour, or too small, will render 
 the picture equally inelegant and obscure. 
 
380 DOMAIN V. CALCAREOUS. 
 
 MODE I. MARBLE. 
 
 Characters. Texture, large or small grained, generally in. 
 distinct concretions ; sometimes so fine grained 
 as to appear compact, and only distinguishable 
 by its glimmering lustre : admitting a fine polish. 
 
 Hardness, of course marmoric. Fracture, fo- 
 liated. Fragments, amorphous, blunt. 
 
 Weight, granitose. 
 
 Lustre, from glimmering to shining; between 
 pearly and vitreous. Somewhat translucent, but 
 the black only on the edges. 
 
 It chiefly consists of about 50 lime, and 40 
 carbonic acid ; whence it is called by chemists 
 a carbonate of lime. 
 
 The most common colours are white and 
 black -, but the others are so numerous, that they 
 may be best observed in the subsequent enume- 
 rations of various kinds of marble. 
 
 For the geognostic relations of this celebrated 
 rock, the reader is referred to Mode III., where, 
 in treating common limestone, a wider field of 
 observation may be opened. 
 
 Mineralogists have sometimes regarded those 
 marbles as primitive which present what they 
 call a granular fracture, of a shining or saline 
 
MODE I. MARBLE. 581 
 
 appearance; while those witjj a dull earthy frac- 
 ture were regarded as secondary. But Brard 
 has well observed, that a true white saline sta- 
 tuary marble, presenting every character of the 
 primitive, may be of very recent formation, as 
 appears from the constant depositions of the 
 waters of St. Philip, in Tuscany, and of several 
 other regions. Marbles of an earthy fracture 
 have been found even among those esteemed the 
 most primitive of the Alps. 
 
 Marble is distinguished from limestone by 
 superior weight, and by superior hardness and 
 compactness, so that it assumes a brighter po- 
 lish. But many of the alabasters will scratch 
 marble, being of course of a still harder nature. 
 
 While the Egyptians often employed the eter- Use in 
 
 OJ r architecture. 
 
 nal granite, the Greek and Roman architects, 
 who required greater roundness and softness 
 of forms, chiefly used marble, as more easily 
 wrought, and likewise more abundant in their 
 countries. Nor does its duration seem much 
 inferior to that of granite, or porphyry, when 
 sufficiently pure and unmixed with argil; for 
 not to mention the beautiful statues (which are 
 often under shelter), ancient temples have suf- 
 fered more from the hand of bigotry or bar- 
 barism than from the lapse of time. Marble is 
 however exposed to accidents which could not 
 
382 DOMAIN V. CALCAREOUS. 
 
 affect granite, or gorphyry. A singular exam- 
 T s e mpL f P^ e occurs in the ruins of the temple of Serapis, 
 on the delicious coast of Baias, where three 
 large columns of Cipoline marble are pierced 
 by pholades, a kind of sea snail, which penetrate 
 deep holes into limestone, whence they are ex- 
 tracted, and called sea-dates, being a luxury of 
 the Italian repast*. These perforations extend 
 to not less than sixteen feet above the level of 
 the sea ; whence some have argued that the lat- 
 ter has subsided, while others suppose that the 
 land has been raised by earthquakes. A more 
 probable and easy solution would be, that these 
 columns have belonged to some more ancient 
 edifice, which may have been ruined by an 
 earthquake, and fallen into the sea ; or the ship 
 which conveyed them may have been wrecked ; 
 or, in fine, the pillars left partly within the sea 
 mark for a certain space of time. For in this 
 very temple, the Pentelican marble of Attica, 
 and the African bricia, occur; and it is well 
 known, from many examples, that the Romans 
 transported obelisks and columns from many 
 countries, to adorn Italy. 
 
 Primitive. The celebrated Buffon had advanced an opi- 
 nion, that all calcareous rocks were mere re- 
 
 * Breislak, ii. 163. 
 
MODE I. MARBLE. 
 
 mains and depositions of shell-fish, and other 
 marine animals. The first who combated this 
 opinion was Palassou, in his celebrated essay on 
 the mineralogy of the Pyrenees, published in 
 1781 ; but which, through the excess of admi- 
 ration for Buffon, fell into oblivion. The opi- 
 nion was however soon after revived and con- 
 firmed by that illustrious observer Saussure, 
 especially in the latter part of his journeys among 
 the Alps. Patrin says that he has frequently 
 himself observed, in the immense mountainous 
 chains of Northern Asia, from the Uralian to 
 the river Amur, for an extent of more than 1000 
 leagues, beds of marble, which it was impossible 
 to suppose for a moment to have been posterior 
 to the other beds of primitive rock, in which 
 they were enchased. He also regards the chains 
 of calcareous hills, mingled with clay-slate and 
 serpentine, which appear at the bottom of the 
 Alps, and other lofty mountains, often in layers 
 contorted in the strangest forms, but still un- 
 broken, as being caused by the tumescence of 
 the granite, while these depositions were still of 
 a soft consistence. 
 
 " Where the thickest calcareous beds subsided 
 in themselves, they formed homogenous masses, 
 without any divisions, or at least there are only 
 accidental fissures. These marbles are granular, 
 
 I 
 
384 DOMAIN V. CALCAREOUS. 
 
 and palpably crystallised in all their parts ; they 
 are generally of a single colour, white, grey, 
 red, or black, and without any mixture of fo- 
 reign substances, except a small quantity ol 
 silex, which is intimately combined, and whose 
 presence is only found by dissolving them in an 
 acid. I have tried some of the purest specimens 
 in this manner ; I always obtained a quartzy 
 sediment; the quartz at times is so abundant^ 
 that these marbles yield sparks against steel. 
 
 <c It is these large masses of homogenous mar- 
 bles which furnish the fine white statuary kinds, 
 such as those of Paros and Carrara : they are 
 never in any very elevated situation. 
 
 " Those which are found interplaced between 
 schistose layers, or mixed with beds of serpen- 
 tine, yield the marbles called Cipolhie, which 
 present long veins parallel to each other, and 
 undulated in various directions. These may be 
 met with in the neighbourhood of the summits 
 of mountains. 
 
 <c I have no need to mention that these mar- 
 bles never contain any vestige of shells, nor other 
 marine productions, as their formation is much 
 anterior to the existence of all organised bodies. 
 
 " Some are found which contain garnets, oc- 
 taecfral iron, and even pyrites, the same as pri- 
 mitive schisti. Rome de ITsle says, that in, the 
 
MODE I. MARBLE. 385 
 
 finest white Carrara marble he has seen blackish 
 spots and veins, produced by a multitude of very 
 small crystals of octaedral iron, affecting the 
 magnet, exactly like those which are found in 
 the ollites of Corsica. 
 
 " Ramorid, in the interesting description which 
 he gives of the peak of Eres-Lids, near Barege, 
 says, that on the summit of that mountain cal- 
 careous beds are observed, which constitute a 
 greenish-white primitive marble, entirely sprin- 
 kled with small duodecagon garnets, round, 
 opake, of the size of the head of a pin. Another 
 variety presents garnet in large irregular crys- 
 tals. These beds of marble alternate with beds 
 of rocks which are indubitably primitive. 
 
 " I have already observed, that calcareous bri- 
 cias are nothing .else than the primitive marbles 
 themselves, the beds of which have been over- 
 turned, while they were still in a soft state."* 
 
 It is equally probable that the calcareous and 
 argillaceous rocks may, in a soft state, have sub- 
 sided from the granite, which had previously 
 crystallised in arrects of great steepness. 
 
 The subject of marbles is almost infinite, as no Arrangement, 
 mineral substance affords such innumerable di- 
 versities, or has so much attracted the attention 
 - 
 
 * Patrin, ii. 304. 
 VOL. I. 2 C 
 
DOMAIN V. CALCAREOUS. 
 
 of mankind. In a scientific point of view, sub- 
 servient tpjthe general plan of this treatise, they 
 may be divided into four principal structures; the 
 Granular; the Compact; the Conchitic, or that 
 containing shells; and the Zoophytic, or that 
 with madrepores, &c. ; beginning with those 
 found in ancient monuments, and ending with 
 the more modern ; the colours being merely re- 
 garded as varieties: though some, from their 
 rarity and singularity, as, for example, the white 
 venular marble of Durness, and lumachellas of 
 Bleyberg and of Castracan, or Castravan, in Sy- 
 ria, falsely ascribed to Astracan, ought rather to 
 form diversities. The bricias, and some others, 
 will of course be described among the Calcareous 
 Glutenites*. 
 
 * The division of marbles by a scale of colours, proposed by 
 Daubenton, has been found alike useless and impracticable. Be- 
 sides the six divisions here adopted, of Granular, Compact, Con- 
 chitic, Zoophytic ; with Serpentine marbles, and Glutenites, there 
 might be the following subdivisions, or aspects : 
 
 Urn-coloured, white, black, red, &c. 
 
 Straight-veined. 
 
 Mazy, with irregular short veins. 
 
 Mixed, equal spots of various colours. 
 
 Spotted, large spots. 
 
 Speckled, middling spots. 
 
 Dotted, small spots. 
 
 Ocular, like eyes, occhiato. 
 
 Streaked, long spots, &c. &c. 
 
MODE I. MARBLE. 387 
 
 STRUCTURE I. GRANULAR. 
 
 In general the ancient and finest marbles belong 
 ) this description; though an ancient white or 
 rey, called palombino by the Italians, and that of 
 
 roconnesus, not to mention a few others, are of 
 fine earthy grain, almost compact. 
 
 The first attention is due to the Egyptian mo- Egyptian, 
 numents, as from that country the arts passed 
 into Greece, and subsequently into Europe. The 
 marble statues and fragments described by Wad 
 are very small, from 10 to 20 inches in height, 
 and present the following colours; milk-white, 
 the same with venular silver-white mica, greyish 
 white, passing to blue, and yellowish white. The 
 chief Egyptian monuments are in granite and 
 basalt. 
 
 But in the Museum at Paris, and other princely 
 collections, there are many Egyptian statues, and 
 other monuments, in the rosso antico, the ancient Rosso an tico, 
 red, the peculiar marble of Upper Egypt, or of 
 Ethiopia, for the cataracts were anciently reputed 
 to divide these countries ; and Syene was esteemed 
 the last town of Egypt, on the very confines of 
 Ethiopia. 
 
 It seems evident, though it has escaped all the 
 critics, antiquaries, and mineralogists, that the 
 superb rosso antico, which, in the grand statues 
 
 2 c -2 
 
DOMAIN V. CALCAREOUS. 
 
 of Agnppa (formerly in the Pantheon), the Anti- 
 nous, Indian Bacchus, and other exquisite remains, 
 surpasses in beauty all the other marbles, is the 
 celebrated Augusteum and Tiberianum of Pliny. 
 
 1. It is allowed that this marble was from 
 Egypt ; and, even in the time of Pliny, was care- 
 fully distinguished from porphyry, which came 
 from the same country. 
 
 2. It was natural to give the imperial name to 
 the imperial colour, which was red, as is known to 
 every classical reader, and the very name of por- 
 phyry evinces. Our purple is the purpura vio- 
 lacea, or violet purple of the ancients. 
 
 3. The other colours were celebrated before. 
 The black was called Lucullean, from Lucullus, 
 as Pliny says. The green of Laconia, the yellow 
 of Numidia, were all well known : and red was 
 the only new colour of marble. Boot supposes 
 that the Augusteum was ciiiereum 7 of an ash grey, 
 because it is ranked with ophite : but several well- 
 known Greek and Italian marbles uere of this 
 very common colour. 
 
 4. The rosso antico alone presents the singu- 
 larity mentioned by Pliny, and which he conveys, 
 as usual, in the most chosen and emphatic Ian- 
 
 Tiber ianum SPA us A non cojivoluta CA- 
 For the ancient red is often sprinkled 
 
 * Edit. Brotier. Som erroneously omit the non. 
 
MODE I. MARBLE. 389 
 
 all over with white dots, like hoar frost. The 
 Augusteum undatim crispum in vertices is the 
 rosso fiorito of the Italians, with little tufts or 
 flowers of white. 
 
 5. Because the other stones, mistaken for the 
 Tiberian and Augustean marbles, are now known 
 not to be Egyptian, just as the green porphyry, or 
 pretended ophite, is not Egyptian. 
 
 The rosso antico therefore is rightly styled 
 Egyptian*. Brard describes this beautiful mar- 
 ble as of a deep blood red, with little distant 
 black or white veins, and often sprinkled with lit- 
 tle white dots. Such is the Egyptian Antinous ; 
 but two ancient seats used in the baths, and the 
 bust of an Indian Bacchus, are free from the 
 veins, though the dots be always visible. The 
 celebrated statue of Agrippa, son-in-law of Au- 
 gustus, in the Grimani palace at Venice, is of this 
 imperial marble, intended perhaps as a special 
 compliment')'. 
 
 The rosso annulate is red, with round white 
 spots ; the seme santo, red, with little triangular 
 
 * Imperati, and Wallerius, i. 134, say the rosso antico was from 
 Upper Egypt. As Syene was on the borders of Ethiopia, it is also 
 called Ethiopicus. (See A pp.) 
 
 t A good engraving is given in Dr. Pococke's Travels in the 
 East, vol. ii. 
 
390 DOMAIN V. CALCAREOUS. 
 
 spots. One of these may be the Claudianum*, 
 if it be not another name for the Tiberian. Gor- 
 dian's villa had fifty Carystean columns (green) ; 
 fifty Claudian (red ?) ; fifty Synnadian (white, 
 spotted with bright red, porto santo-\}; fifty Nu- 
 midian (yellow). 
 
 of Paros. j n passing to the Grecian first occurs the white 
 marble of Paros, sometimes called lychnites by 
 the ancients, because the quarries were explored 
 by lamp-light. A transparent kind, called phen- 
 gites by Pliny, was also found in Cappadocia, and 
 is said by Chardin to occur in Persia. Domitian 
 is reported by Suetonius to have formed galleries of 
 a kind of stone that reflected the figures of persons 
 behind him, corruptly called phengites, while it was 
 probably a fine black marble. 
 
 The Parian marble was employed by the most 
 ancient Greek sculptors, about the fortieth Olym- 
 
 * Hist. Aug. 676. 
 
 f Perhaps thejiore de persico, or peach blossom j but travellers 
 may observe the original quarries in Natolia. 
 
 The rosso antico, when unpolished, is of a dark dull appearance, 
 which obscures its difference from ophite. But as, in treating of 
 metals, Pliny begins with gold and silver ; and in gems, the dia- 
 mond and the emerald ; so in marbles he begins with the most 
 precious, as he says, the Laconian green, the Egyptian (red), and 
 ophite. Any relation of colours or qualities is not in view, but 
 only the value. 
 
MODE I. MARBLE. 
 
 391 
 
 piad; but being of a yellowish tint and coarse 
 grain, it was afterwards supplanted by the marble 
 of Luna, in Etruria, as afterwards by that of Car- 
 rara, in the same vicinity. 
 
 In the great museum at Paris, the Venus de 
 Medici, Diana hunting, Venus leaving the bath, 
 the colossal Minerva, the Juno of the Capitol, the 
 Ariana called Cleopatra, and several others, are 
 of Parian marble. The celebrated Parian tables 
 at Oxford, which have illustrated many points of 
 ancient chronology, are also inscribed upon the 
 same stone. 
 
 Pentelican marble, from the vicinity of Athens*, 
 is white, like the former, but with a finer and more 
 compact grain. It sometimes presents blackish 
 veins from a siderous mixture, and sometimes 
 green veins of the talcous kind, so that it is at 
 Rome called statuary Cipoline. 
 
 Most of the noble monuments of ancient Athens 
 are constructed with this marble ; and several sta- 
 tues are extant, as in the Museum of Paris, a 
 Bacchus in repose, a Jason, a Paris, a tripod of 
 Apollo, &c. &c. f 
 
 The vague name of Greek marble has been 
 
 * Concerning the mines of Attica see Xenophon de Vectigalibus. 
 
 t Brard, 324. Petrini says, ii. p. ix, that the Pentelican, with 
 mica, has grains of chalcedony, as the Carrara has rock crystal : 
 probably. from a mixture of argil. 
 
 Pentelican. 
 
 Greek, 
 so called. 
 
3$3 DOMAIN V. CALCAREOUS. 
 
 given to a fine-grained and hard kind, of a snowy 
 whiteness. It was from several islands in the 
 Archipelago, as Scio, Samos, &c. In the Parisian 
 Museum, which derives its name from the Em- 
 peror Napoleon, there are an Adonis, a Bacchus, 
 the philosopher Zeno. The Fawn is supposed by 
 Brard to be of the marble called Coralian by 
 Pliny, because found near the river Coralus, in 
 Asia Minor, and which, in whiteness and grain, 
 resembled ivory. Some assert that the finest sta- 
 tue in the world, the Apollo of Belvidere, is formed 
 of what is called the Greek marble; but most 
 mineralogists infer it to be marble of Luna. 
 Translucent. At Venice, and in different towns of Lombardy, 
 are columns and altars of a singular marble, so 
 translucent, that the light of "a candle is visible 
 through pretty thick masses. This is perhaps the 
 Cappadocian phengites. 
 
 Elastic. Tables of ancient elastic marble occur in the 
 palace Borghese at Rome. It has been recently 
 asserted that this quality may be imparted by a 
 certain modification of heat, which loosens the 
 structure, so that the calcareous scales move in 
 certain directions. 
 
 Irffta/"' White marble of Luni (the ancient Luna), or 
 Carrara, on the shores of Tuscany. Though 
 these two places be nearly adjacent, yet some 
 assert that the marble of Luni is finer than that of 
 
MODE I. MARBLE. 
 
 Carrara, and free from the grey veins that some- 
 times appear in the latter. The Antinous of the 
 Capitol is said to be of marble of Luni. That of 
 Carrara, as just mentioned, often presents grey 
 veins, so that it is difficult to procure blocks of an 
 uniform white. It has been much used for chim- 
 ney-pieces in England ; and is often mingled with 
 the yellow and dull purplish bricia of Sienna : but 
 the quarries are said to have been opened at least 
 as early as the time of Julius Caesar. The Car- 
 rara marble has sometimes greenish talcous veins, 
 like the cipolino, and sometimes crystals of iron. 
 But the most beautiful specimens are those which 
 contain, in little cavities, rock crystals of the 
 purest water, called in Italy diamonds of Car- 
 rara. 
 
 White marble of mount Hymettus, in Attica; OfHymettns. 
 rather inclining to grey : but it was the first fo- 
 reign marble introduced at Rome, where this mo- 
 derate magnificence was thought so extraordinary, 
 that Crassus the orator was exposed to the sar- 
 casms of Marcus Brutus, because he had adorned 
 his house with six columns, twelve feet high, of 
 Hymettian marble. Such were the chief white 
 marbles employed by the ancients. 
 
 The ancient black is so intense that, when 
 placed beside those of Dinan and Namur, it makes 
 them appear grey. Some pedestals and busts of 
 
394 DOMAIN V. CALCAREOUS. 
 
 this marble still exist, but this kind is of extreme 
 rarity*. Perhaps age may have rendered the co- 
 lour more intense. Black marble may sometimes 
 serve as a touchstone ; but the test of nitrous acid 
 cannot be applied. Monuments of black marble 
 may be revived by anointing them with oil. 
 
 The ancient green marbles have already been 
 partly described among the Magnesian Rocks. 
 The Appendix may be also consulted. 
 
 Ancient marble, in long regular veins of white 
 and grey. 
 
 Ancient marble, of reddish white, w ith spots of 
 a slate blue, disposed in festoons. 
 
 Ancient marble, of a deep red, with numerous 
 grey and white veins, supposed to be from Africa. 
 Yellow. The ancient yellow, of thrdfe kinds, uniform ; 
 resembling the yolks of eggs ; and with black or 
 deep yellow rings, whence it is called ring marble. 
 Its place is imperfectly supplied with the yellow 
 marble of Sienna. The ancient was from Numi- 
 dia, in Africa, as appears from many classical 
 writers j". 
 
 * It is supposed to be from Tenarus, in Laconia, and entirely 
 dissolves in the nitrons acid. Petrini Gab Naz. i. 143. 
 
 f See the Appendix ; and Gibbon, vii. 201. For it came from 
 Mount Maurasius, or Aurasius, the citadel and garden of Numidia, 
 near Lambesa, once a Roman city of 40,000 souls. Si tin, which 
 yields the turquin marble, is in the same quarter. 
 
MODE I. MARBLE. 
 
 Other ancient marbles will appear among the 
 Calcareous Glutenites. To enumerate modern 
 marbles would be infinite, but the more remark- 
 able of each country shall be selected, giving the 
 usual and due preference to our own. 
 
 ENGLAND. Some of the most beautiful will 
 be found among the Conchitic, or shell kind. The 
 black marble of Derbyshire. Intense black mar- 
 ble, with distant white spots, Somersetshire. The 
 Cottam marble, found near Bristol, has black 
 dendritic delineations. Brown marble, variously 
 veined, from Devonshire. This is the marble 
 from Plymouth and Torbay, mentioned by Da 
 Costa, as of a fine deep black, beautifully varie- 
 gated with irregular veins of red, yellow, and 
 white. Much was brought to London, and worked 
 into chimney-pieces, tables, &c. He also de- 
 scribes a marble of a dull yellow, with many dots, 
 streaks, and spots of black, as found at Yeovil, 
 in Somersetshire ; and elegant tables of it may be 
 seen in that county, though it is not capable of a 
 fine polish *. The green and red marbles of Angle- 
 sea have already appeared in the Talcous Domain'}*. 
 
 * Fossils, p. 221, 2l6. The Devonshire marble is mostly dull, 
 of a grey or a pale red, with spots of a deeper colour. It often con- 
 tains madrepores. The black kinds, with red arid yellow invo- 
 lutions, are the most elegant. 
 
 ^ Da Costa, p. 220, in speaking of the green marbles variegated 
 
396 DOMAIN V. CALCAREOUS. 
 
 SCOTLAND. White statuary marble of As- 
 synt. White marble, with long veins of a differ- 
 ent tint, from Durness. Red and white marble 
 of Boyne. The beautiful rose-coloured marble of 
 Tirey, mingled with siderite, c. is reserved for 
 the Composite Rocks. The same isle presents a 
 beatftiful white marble, with veins of nephrite. 
 Numerous other marbles might be explored in the 
 Highlands of Scotland ; and a French author is 
 singularly unjust when he says that the British 
 
 with white, mentions the Egyptian, which he rather supposes to 
 be the Tiberian and Augustean (though no green marble be found 
 in Egypt) j then a second, which is the polzavera ; and a third the 
 green of Susa ; and a fourth from Sweden. He then adds, " These 
 are the chief varieties of this marble, which, besides the places 
 already mentioned, is found in several parts of Europe; in the 
 northern part of the island of Anglesea, in Wales, in the parish of 
 Llan Fairyng Hornuy; and in Inis Molroniad, or the Island of 
 Sea Calves, there are rocks of this kind of marble with veins of fine 
 asbestos ; and a quarry of the same marble is dug near Kemlyn, and 
 another at Monachty, in the same island. 
 
 " Woodw. Cat. A. X. b. 3, exhibits a dusky green marble, 
 veined with white, which he found in the way between Ambleside 
 and Penrith, in Cumberland, where it is in considerable quantity : 
 it probably is of the same species." 
 
 So ancient is the knowledge of the beautiful Anglesea marble, 
 which has been regarded as a recent discovery. In the Journal des 
 Mines* is an extract from Pennant's Tour in Wales concerning 
 this marble ; which is also said to be found in the Skerries, a little 
 isle near Anglesea. 
 
 * No. 16, p. 75. 
 
MODE I. MARBLE* 397 
 
 Isles are poor in marbles *. It is only the fashion- 
 able rage after foreign kinds, joined with an old 
 routine of commerce, blindly followed by the ma- 
 nufacturers, which prevent vast treasures of this 
 decoration from being discovered in Great Britain 
 and Ireland ; particularly in Wales, and the High* 
 lands of Scotland. 
 
 IRELAND. Near the celebrated lake of Kil- 
 larney are found white and red, and black and 
 white marbles. Indolence and ignorance have 
 prevented further research. The fine black mar* 
 ble of Kilkenny is conchitic; but the north of 
 Ireland yields a brown marble, and one of a pal 
 white, like earthenware f. 
 
 Having begun with these northern regions, it 
 may be proper to continue in the same climate, 
 that the comparative view may become mora 
 distinct. 
 
 NORWAY. The marble of Gillebeck, which 
 resembles that of Tirey, will be described among 
 the Composite Rocks. Even the Danes show a 
 more patriotic taste than Britons, for it has been 
 employed in constructing the church of Frederic 
 
 * Brard, 442. Some of the Assynt marbles promise well, but 
 due quarries are not yet sufficiently deep to expect the finest kinds. 
 Those of Italy have been worked for 1500 years. Adits might be 
 found advantageous. 
 
 t Da Costa, p. 210, says a grey marble, with white spots, from 
 the county of Cork, was much used in Ireland. 
 
398 DOMAIN V. CALCAREOUS. 
 
 at Copenhagen. Many other Norwegian marbles 
 are faintly described by Pontoppidan and Fabri- 
 cius ; but there is no encouragement for the ex- 
 ploration. 
 
 DENMARK. The Danish islands present some 
 coarse marbles, but none has attracted particular 
 notice. 
 
 SWEDEN. This country has evinced its good 
 sense and patriotism in establishing considerable 
 manufactures of porphyry and ollite ; but marble 
 seems rare and of little value. 
 
 RUSSIA and SIBERIA.- On this subject there 
 cannot be a better guide than Patrin, who resided 
 many years in these regions. 
 
 " In Siberia, the Ural mountains furnish the 
 finest and most variegated marbles. The greater 
 part are taken from the neighbourhood of Ekater- 
 inburg, where they are wrought, and from thence 
 transported into Russia, and particularly to Pe- 
 tersburg. The late empress caused an immense 
 palace to be built there, for Orlof her favourite, 
 which is entirely coated with these fine marbles, 
 both inside and out. It is situated on the bank 
 of the Neva, and is one of the chief ornaments of 
 that capital. This empress built the church of 
 Isac with the same marbles, on a vast space, near 
 the statue of Peter the Great. This church was 
 not finished in 1787. I there saw columns, of 
 
 
MODE I. MARBLE. 399 
 
 very large dimensions, which seemed to me to be 
 of a single block, of a white and bluish marble, in 
 large veins : only this kind of marble was used in 
 this church. The palace of Orlof has many va- 
 rieties, which are distributed in compartments. 
 
 " I saw no white statuary marble in the Ural 
 mountains; but in that part of the Altaian moun- 
 tains which is traversed by the river Irtish, I in 
 two places saw enormous rocks of marble, per- 
 fectly white and pure, from which large blocks 
 might be hewn. The only use made of it is to 
 convert it into lime, for the service of the for- 
 tresses situated along the Irtish."* 
 
 o 
 
 The celebrated grotto of Kungur is by some 
 said to be in a coarse white marble, by others in 
 alabaster. The village of Kurigur is near the 
 skirts of the Uralian chain, on the confines of 
 Europe and Asia, about fifty miles to the S. S. E. 
 of the city of Perm, in the government of the 
 same name. It is said to be six wersts, or about 
 a league, in length, and half as much in breadth. 
 There are several openings in the roof, so that 
 there is a subterraneous meadow with grass and 
 flowers, a little lake, a rivulet rising from a de- 
 tached rock, which, like another springing from a 
 pool, soon loses itself underground ; with natural 
 
 * 
 
 . 8. 
 
400 DOMAIN V. CALCAREOUS. 
 
 stairs; an image of St. Nicholas, and crosses 
 erected by the Russians. Gmelin, who occupied 
 five or six hours in visiting a part of this remark- 
 able grotto, adds, that it is not after all so singular 
 as that of Bauman in the Hartz, and as the Neble 
 Loch, or Misty Hole, in the Duchy of Wirtem- 
 berg*. 
 
 On descending to the more southern kingdoms, 
 we find the Turks occupied in converting the no- 
 blest monuments of Greece into lime ; instead of 
 exploring the ancient quarries of the islands, 
 among which Anti-Paros displays its celebrated 
 grottos in the purest white marble, with rich sta- 
 lactites and stalagmites of the same beautiful 
 substance ; and said to be as saline as that called 
 primitive. The beautiful green of Laconia is alike 
 unknown to these barbarians. 
 
 GERMANY. White marble of Ratisbon. That 
 of Hildesheim approaches to ivory ; and the same 
 place likewise furnishes an ash grey. Wolfenbutel, 
 greyish white. Osnabruck, fine black. Oster- 
 gyllen, spotted, white, yellow, and deep grey. 
 Between Leipsic and Bareuth there is a quarry of 
 chesnut and liver- colour, with veins of deeper 
 tints. Ash grey, with black ramifications, from 
 Goslar. Green, veined with yellow, probably a 
 
 * See his Journey to Siberia, in the Hist. Gen. des Voyag 
 torn. 24, 4to. p. 128, where there is a ground plan. 
 
MODE I. MARBLE. 
 
 401 
 
 serpentine, from Salzburg. Red, from Ratisbon, 
 Bohemia, and Trent. Straw yellow, with black 
 dendrites, from Hessia. It is only formed into 
 little pictures ; and, like the Florentine, is a marlite 
 abounding in argil. 
 
 SWISSERLAND. -In general dull violet, spotted 
 or veined with black. There are some of a bluish 
 grey, resembling what is called the blue turquin, 
 which comes from Africa, and is spotted with 
 siderite, and the blue marble of Narbonne ; both 
 of which however should be called grey, for no 
 blue marble has hitherto been discovered, that 
 colour being almost peculiar to the precious 
 stones ; but it appears in alabaster, a blue trans- 
 lucent kind of which is found near Nottingham *. 
 
 FRANCE. The most singular is perhaps the 
 blue of Narbonne, described by Patrin as of a 
 deep blue, spotted with bright grey. Brard says 
 that it is white, mingled with bluish grey, and is 
 in the highest esteem, being sometimes improperly 
 called marble of Languedoc. Of the beautiful 
 red marble, which forms many chimney-pieces at 
 Chantilly, often spotted with a deeper colour, and 
 
 imetimes with white spar, I cannot discover the 
 
 ! 
 
 * The mountain of Cramont, near Mont Blanc, is composed of 
 a coarse marble, of that kind which the Italians call cipolino; the 
 base being large-grained, and confusedly crystallised, of a slate 
 blue, with white veins and spangles of mica. Sauss. 915. 
 VOL. I. 2 D 
 
402 DOMAIN V. CALCAREOUS. 
 
 site, if it be not the griotte of Canne, not far from 
 Narbonne*, which is a deep red, spotted with 
 white, or the Serrancolin, which is of a fair red, 
 mingled with yellow and grey, and is dug near the 
 river Neste, which joins the Garonne. Patrin 
 says, that fine large blocks of Serrancolin have 
 been raised for the decoration of the royal palaces 
 of France. The Pyrenees furnish many marbles, 
 as the green and red of Campan; and, among 
 others mentioned by Palassou, the pure primitive 
 white of Loubie, the grey of Barege, the red of 
 Serrancolin already mentioned^ with those of Scix, 
 mingled with argil and talc, like the Campan. 
 Red, with yellow spots, from Poitou. Pale red 
 ' and yellow, from Tournus, which decorates many 
 churches at Lyons. Grey, veined with white and 
 golden yellow, from Bourbon-Lancy. Red, with 
 white veins, from Caen in Normandy. That of 
 Marquise, near Boulogne, with large yellow spots 
 and red veins. Many of the Flemish marbles are 
 black, veined with white ; the others chiefly be- 
 long to the Conchitic or Zoophytic divisions. 
 
 * So says Patrin ; but I can only find one Cannes, near Antibes. 
 Brongniart says Cosne, in the department of Allier. Marbles, like 
 jewels, being common objects of commerce, many frauds are prac- 
 tised, and many errors in consequence arise. But an eastern marble, 
 probably the Synnadic, is compared, by Tournefort, with the red 
 and white cf Cosne in Languedoc. 
 

 MODE I. MARBLE. 
 
 403 
 
 To these may be added the following, indicated 
 by Brard. Spotted with red, white, grey, and 
 yellow, from the vicinity of Mont Dauphin, in the 
 Upper Alps. White, rose, and green, mingled 
 with garnets, needles of lepidote, and shining 
 spangles of iron ; this beautiful marble, of a saline 
 grain, is found at St. Maurice, in the Val God- 
 mar, but it belongs to the Composite Rocks. St. 
 Maurice likewise furnishes cipoline. Deep violet, 
 spotted with yellow, from Narbonne. Bariol6 9 or 
 streaked with various colours, white, red, and yel- 
 low, from the mouths of the Rhone, much esteem- 
 ed, being called marble of St. Bawne, and reputed 
 equal to Spanish brocatdlo. White, veined with 
 grey, from the department of Mont Blanc, vory 
 hard, being combined with silex. Grey and white, 
 spotted with red, from Liege. Of a light coffee 
 colour, with white, grey, and red veins, from Bou- 
 logne. Of Antin, white, with veins of a fiery red. 
 Lilac, from the Pyrenees. Black of Dinan, bitu- 
 minous : it is sometimes powdered with white 
 spots. Black, or rather grey, of Namur, much 
 used in Holland*. Isabella colour, with trans- 
 parent spots of deep brown, from Mont Rouge, 
 
 * Where it is called llaeuwc stein, or blue stone. Hill, perhaps, 
 thought Namur a town in Africa; for he gravely affirms this to be 
 the Numidian mafble of the ancients, -which is literally toto ccelo 
 frrart. 
 
 2 D 2 
 
404 DOMAIN V. CALCAREOUS. 
 
 near Paris. Yellow, with black dendrites, from 
 Rouen. Of St. Maximin, department of Var, 
 much esteemed in commerce, and called portor, 
 or the gold-bearer, because in that of the best 
 quality it is black, veined with golden yellow*. 
 White, from Civrai, reputed too hard by the mar- 
 ble-cutters, while this is in fact a perfection of 
 marble. 
 
 Many curious marbles are also found in the 
 isle of Corsica, now subject to France, as the cipo- 
 line of Corte ; and the isle of Elba has immense 
 quarries of white, veined with blackish green, and 
 also the cipoline. 
 
 The French make great use of marble, in tables 
 of all kinds, &c. &c. ; to which practice may in 
 part be owing the infrequency of conflagrations, 
 and no insurance company could derive the least 
 advantage in that country. 
 
 SPAIN. The milk-white of Cordova. Near 
 Filabres there is a mountain, about a league in 
 circuit, and 2000 feet in height, which is one en- 
 tire block of the purest white marble, and capable 
 of the highest polish. This singular mass is about 
 three leagues from Almeria, in Grenada. The 
 famous palace of the Alhambra, at Grenada, is 
 partly constructed from the white marble rocks, 
 
 * Da Costa, p. 203, says it was much used in England, 
 
MODE I. MARBLE. 
 
 405 
 
 around the town of Molina, in New Castile. In 
 the neighbourhood of Grenada, white saline mar- 
 ble, slightly tinged with red. Similar, but of a 
 finer grain, from Badajos in Estremadura. White, 
 with large grey spots, from La Mancha*. Grey, 
 from Toledo. Grey, veined and spotted with 
 white. Black, with grey and white, from Moron, 
 La Mancha, and Biscay; which last also furnishes 
 a black, veined with ochre red. Violet, elegantly 
 spotted with bright yellow, from Tortosa : this is 
 the celebrated brocatello of Spain. Dull red, 
 veined and spotted with a lively red and shining 
 white, resembling grio tte -)*. Of a dull violet, like 
 wine lees, with little orange spots, from Valencia. 
 Flesh-coloured, veined with white, from Santiago ; 
 and there is also an entire mountain of this kind 
 near Antiquera. Fawn-colour, powdered with 
 grey, Cortegana. Dull red, with black capillary 
 veins, Valencia. Near Morviedro there is a hill 
 of black marble, veined with white, which gradu- 
 ally passes into a yellow, blue, and red bricia, at 
 the summit. Red, yellow, and white, of Molina. 
 Red, veined -with grey, from Guipuscoa. The 
 
 * The French call such a marble Tigrf, ifc should be Leopard^. 
 The tiger is barred, the leopard spotted. 
 
 f Griottc seems originally to imply a large deep red cherry. The 
 round dark spots might occasion the name. 
 
406 DOMAIN V. CALCAREOUS, 
 
 Others are Conchitic and Zoophytic marbles and 
 bricks. 
 
 PORTUGAL. The mountains of Arrabeda fur- 
 nish some esteemed marbles. That of Troncao is 
 a pale yellow, with grey veins, and sometimes con- 
 tains shells. 
 
 ITALY. The chain of the Apennines being 
 chiefly calcareous, and Italy the seat of numerous 
 ancient monuments, and the parent of modern 
 sculpture and architecture, it is no wonder that 
 the Italian marbles have been highly celebrated. 
 White marble of Padua, Pisa, Pilli, and Biancone, 
 all used in architecture in the north of Italy. The 
 cathedral of Milan is built with a white saline 
 marble, veined with grey, from Mergozzo*. Black 
 marble of Bergamo, of the most pure and intense 
 tint, and finest polish, whence the Italians call it 
 parago?ie. Black of Como,. employed in the ca- 
 thedral of Sienna. Deep black, with pure white 
 veins. Polveroso, or powdered marble of Pistoia, 
 sprinkled with little dots, so as to appear dusty. 
 White, with large black spots, from Lago Mag- 
 giore, used in the decorations of most of the 
 
 * The primitive marble, white, with some veins of grey, and of 
 which the cathedral of Milan is constructed, leaves in the nitrous 
 acid white quartzy sand, with some pyrites and greeuioh siderhe, 
 Sauss. 1/71. 
 
MODE I. MARBLE. 407 
 
 churches of the Milanese. The green of Florence 
 belongs to the magnesian, as does the verde-di- 
 Prado, so called from the little town of Prado, 
 but; as others say, from Corsica*. Slate blue, 
 veined with brown, from Margorre. Of Brema, 
 yellow, with white spots. Light red, spotted with 
 white, from the Veronese. Bluish grey, or what 
 is called blue, of Rosso f. White, with little spots, 
 and dots of blood red, from Luni. The yellow of 
 Sienna is one of those called brocatelli, or em- 
 broidered, the colour resembling the yolk of an 
 egg, in large irregular spots, surrounded with 
 veins of a dull purple. The commerce with Li- 
 vorno, strangely corrupted by our seamen into 
 Leghorn, has rendered this marble very common 
 in England. It is certainly beautiful, but far in- 
 ferior to the green of Anglesea, or the rose, spot- 
 ted with green, from Tirey. Yellow, veined with 
 black, also from the neighbourhood of Sienna J. 
 The curious marble of Florence, stained with re- 
 semblances of ruins, &c. and which, with the den- 
 dritic, might be styled pictorial, being framed like 
 
 * What is called the Egyptian green, is a polzevera from the 
 vicinity of Genoa. It is so called because it resembles the verd 
 tmtique, which was supposed to come from Egypt. See Da Costa, 
 p. 200. Patrin says it is from Carrara. 
 
 f The pauonazzo should be i\ purple, or dark blue. 
 
 % At a place about nine miles distant, called Mont Arrenti, at 
 the head of the vale of Rosia. 
 
408 DOMAIN V. CALCAREOUS. 
 
 pictures, properly belongs to the marlites. Orange, 
 or bright red inclining to yellow, like the gem 
 called jacint, from Verona; but as it sometimes 
 presents ammonites, it rather belongs to the Con- 
 chitic : the tomb of Petrarca, at Arquoi, recently 
 engraved by Faujas, is of this marble. A duller 
 red was used by the Romans in building the vast 
 amphitheatre of Verona. Six leagues from Ve- 
 rona Faujas observed a singular kind, which he 
 calls bone-marble, being of the same red paste, 
 with a greenish shade, and presenting large white 
 spots, which are petrified bones ; but he has not 
 explained to what animal they belong. Large 
 columns of this singular marble have been ex- 
 tracted *. 
 
 Sicily. The chief marble of Sicily is red, with long 
 
 stripes, like ribbons, white, rose-coloured, and 
 sometimes greenish, which at intervals revolve, 
 forming pretty acute angles. This singular mar- 
 ble is of the highest value f . Bisachino not only 
 presents a milk white, but an apple green, which 
 takes the finest polish, probably a serpentine. 
 Trapani possesses a red, with deeper spots ; and 
 another red, spotted with green ; not to mention 
 
 * Brard, 418. 
 
 f It is a heavy ferruginous kind, whence our ma.rble-cutters call 
 it Sicilian jasper. It is perhaps from Giuliano, in the south- west 
 of Sicily, a spot famous for products of this kind. 
 
MODE I. MARBLE. 
 
 409 
 
 grey, spotted with several colours, and one com- 
 posed of spots red and yellow. Castro Nuovo, 
 yellow, spotted with red. Taormina, red, spotted 
 with black, or a deeper red ; yellow, spotted with 
 white and black ; and a yet more singular, green- 
 ish, with bright brown spots; and a lilac, with 
 w r avy reflections. Termini, greenish, veined with 
 white, and dotted with red. Near Sciacca ap- 
 pears a bright green, waved with deeper green 
 and yellow. In the river Niso are found frag- 
 ments of red, spotted with a white semi-trans- 
 parent substance, like chalcedony. 
 
 As marble so much abounds in Europe, there 
 was no occasion to import it from the other con- 
 tinents, and their products of this kind remain of 
 course little known. In ASIA Dr. Shaw men- 
 tions a dendritic marble of Mount Sinai, which 
 has been confounded with the pictorial marble of 
 Florence, as appears from Wallerius. Persia con- 
 tains many marbles, mentioned by Chardin, parti- 
 cularly the translucent white. The kingdom of 
 Siam, and China, also present edifices of beautiful 
 white marble. Hindostan does not appear rich 
 in this production. Some of the statues and mo- 
 numents are rather of a coarse limestone than a 
 marble. 
 
 The AFRICAN marbles were among the most 
 celebrated of antiquity, when the northern part of 
 
 Asiatic. 
 
 African. 
 
410 DOMAIN V. CALCAREOUS. 
 
 that continent was possessed by the Egyptians, 
 Carthaginians, and various Greek colonies, and 
 afterwards ruled for many centuries by the Ro- 
 mans. As the intercourse with Italy remained 
 frequent till the seventh or eighth century, there 
 is the less occasion for wonder that the tradition 
 of the Roman artists should have preserved the 
 distinctions of some African marbles ; and as they 
 are not numerous, it will be more satisfactory to 
 consider them all in one point of view. 
 
 What is called the ancient red, already de- 
 scribed. This is dotted or pondered with white; 
 but there is another kind with white spots. 
 
 The dark red, with small triangular white spots, 
 must also be classed among the African ; and the 
 red, with spots like flames. Similar marbles are 
 called./fonYz, among which is a white or grey, with 
 purple flames*. 
 
 > iimidfon. The ancient yellow, according to Boot and Wai- 
 terms, and many ancient authorities, was from 
 Numidia; as was the grey with yellow spots. 
 Pliny, who informs us that ships were built for 
 the sole purpose of importing marbles t, mentions 
 the Numidian and Synnadic as being variegated 
 by art, with inserted fragments. He reproaches 
 
 the bad taste of those who altered the natural 
 \ 
 
 * For the African bricia see the Glutenites. 
 f xxxvi. 1. 
 
MODE I. 
 
 appearance of marble, by insertions added to the 
 natural spots, so as to represent animals and oth< T 
 objects*; whence the Numidian was diversified 
 with artificial eggs, and the Synnadic with rich 
 crimson spots, instead of the dull red furnished 
 by nature 'f. In another passage he says that 
 Lepidus first used Numidian marble in his house, 
 even his threshold being paved with it; whence 
 he incurred public reproach for the new luxury . 
 Four years after, Lucullus brought a marble to 
 Rome, which was called Lucullean, being black, 
 and found in an island of the Nile. But luxury 
 assumed a far wider career, "for ages after the 
 time of Pliny ; and many marbles unknown to 
 that illustrious author must have been imported 
 from Africa, and other countries. 
 
 * xxxv. i. 
 
 f This precious marble was brought from the very centre of Asia 
 Minor, Sinnada, or Synnada, being a town in the greater Phrygia. 
 Strabo says, lib. xii. " Sinada is a town of no great size, before 
 i which is a plain of about sixty stadia, planted with olive trees. 
 Further on is the village of Docimia, and the quarries of Sjjnadic 
 stone ; for so the Romans call it, but the natives Docimite. At first 
 only small pieces were extracted ; now, on account of the prodigious 
 luxury of the Romans, immense and entire columns are hewn out, 
 the stone approaching nearly to the alalastrites in variety. Many 
 loads of this kind are carried down to the sea; and columns and 
 tables of admirable size and beauty are exported to Rome." 
 
 See the Appendix, for a fuller account of the Synnadic, African, 
 fcnd other ancient marbles. 
 xxxvi. 6. 
 
41 C DOMAIN V. CALCAREOUS. 
 
 A singular marble is still known to be found at 
 Sitifi, in the north of Africa, being the proper tur- 
 quin, because, like the turquois, it is supposed to 
 be brought from a country subject to the Turks *. 
 It is of a bluish grey, or slate colour, with spots 
 of siderite or hornblende ; and seems to be one of 
 the most primitive. 
 
 American. The common marbles abound in AMERICA ; and 
 the conchitic is found at the height of 12,000 feet 
 in the Andes. The following observations are 
 from Molina's admirable essay on the natural 
 history of Chili. 
 
 " The calcareous stones which this country fur- 
 nishes, are limestones, marbles, calcareous spar, 
 and gypsum. Among the limestones some are 
 found very compact, and of all the colours ; as 
 are the coarse-grained, while the common lime- 
 stone is white, bluish, and grey. The marbles of 
 a single colour hitherto discovered are, white sta- 
 tuary marble, black, greenish, yellow, and grey. 
 Two mountains, the one in the Cordelera of Co- 
 piapo, and the other in the marshes of Maule, en- 
 tirely consist of marble in zones of several colours ; 
 but in such strata as surround the mountains, 
 from their base to the summit, with a symmetry 
 that seems an artifice of nature. The variegated 
 
 * Some say turquin, turchino, is derived from the blue colour of 
 the turquois. 
 

 MODE I. MARBLE. 413 
 
 marbles ate, the grey, with white, yellow, and 
 blue veins ; green, speckled with black ; and yel- 
 low, with black, brown, and green irregular spots. 
 This last, the quarry of which is at San-Fernando, 
 the capital of the province of Colchagua, is in 
 great esteem, because it is easily wrought, and 
 hardens in the air. All the marbles of Chili are 
 generally of a good quality, and all take a good 
 polish. Persons who have had occasion to ex- 
 amine the lower Andes, have assured me that 
 those mountains abound in marbles of different 
 qualities, and nearly of all colours ; but the ac- 
 counts I have received are too superficial to en- 
 able me to give exact descriptions of them. In 
 the plains near the city of Coquimbo, a white shell 
 marble has been found, somewhat granular, three 
 or four feet under the vegetable earth. The shells 
 in this marble are more or less entire, and give it 
 all the appearance of a real lumachdla. The bed 
 of this marble extends in length and breadth more 
 than three miles ; its thickness, generally about 
 two feet, varies, and depends on the number of 
 the beds, which are sometimes five, sometimes 
 eight. These beds are almost always divided by 
 very thin layers of sand. This stone increases in 
 hardness in proportion to its depth. The first 
 beds only present a coarse friable stone, of no use 
 but to make lime: the following, although com- 
 
4J4 DOMAIN V. CALCAREOUS. 
 
 pact, easily yield to the iron instruments used to 
 cut it, and raise it from the quarry; but in build- 
 ing acquire a sufficient hardness to resist any im- 
 pression of the air or water."* 
 
 Many curious marbles are also found in New 
 Spain, and in North America. The chief quar- 
 ries in the territories of the United States are at 
 Stockbridge, and Lanesborough, Massachusetts; 
 sundry places " in Vermont and Pennsylvania ; 
 Amenia, in New York ; and in Virginia : some 
 of which fully equal the finest specimens from 
 Europe f . At Marble Town, near Hudson river, 
 are quarries of fine black marble, spotted with 
 white shells. 
 
 STRUCTURE II. COMPACT. 
 
 This division has scarcely been observed by 
 mineralogists, except in a few instances. Accord- 
 ing to Werner's system, it must chiefly belong to 
 the transitive, and the floetz or horizontal rocks. 
 Some few examples have been already mentioned 
 of very compact ancient marbles, with a fine frac- 
 ture like the argillaceous substances, such as the 
 palombmo, and that which resembles ivory. That! 
 called Greek, and the ancient black and yellow, 
 also approach to this division. 
 
 Molina, St. Nat. p. 77. 
 
 Spafford's General Geography, Hudson 1809, 8vo. p. 1QO. 
 
 
MODE 
 
 MARBLE. 
 
 415 
 
 Many of the marbles used in the Egyptian mo- 
 numents appear to be of this description, and 
 Wad has divided them into two kinds, the densum, 
 and the lamellosum granular e. Of the former 
 are snow white, and yellowish white, reddish and 
 yellowish grey, and Isabella yellow, passing to 
 yellowish brown*. lie adds that the lapis Troicus, 
 of which, according to Strabo, the pyramids were 
 chiefly built, must belong to this sort, as Niebuhr 
 says they are constructed of limestone full of por- 
 pites, or nummulites, drawn from the mountains 
 called Mokattam, but anciently Mans Troicus. 
 But, according to many specimens and recent ob- 
 servations, the pyramids are built of a beautiful 
 fine limestone, which often contains shells. M. 
 Eicziere, an excellent judg^, in the abstract of 
 Egyptian mineralogy, which he presented to me, 
 'egards the two long chains of mountains, which 
 confine on either side the long valley called Egypt, 
 as being both of a calcareous nature, the sand- 
 stone only beginning about twenty leagues from 
 the cataracts, a little above the town of Esneh. 
 The celebrated tombs excavated at Thebes must 
 of course be in limestone. 
 
 Among the modern marbles, the most compact 
 are those referable to the marlites, as being corn- 
 
 * The African red is often compact. 
 
 Ancient. 
 
 Modern. 
 
DOMAIN V. CALCAREOUS. 
 
 Lined with a considerable quantity of argil. The 
 others have seldom attracted especial observation ; 
 and the division indeed cannot be regarded as of 
 much importance, as even in geology the granular 
 marbles cannot always be regarded as primitive, 
 nor the earthy as secondary. 
 
 Most of the compact marbles also contain shells, 
 so that they belong to the next subdivision. 
 
 STRUCTURE III. CONCHITIC. 
 
 Of Bieyberg. The most beautiful and celebrated of this kind 
 is a recent discovery, being found at Bieyberg in 
 Carinthia, where it appeared in a bed of common 
 limestone, above a vein of lead. It is unfortu- 
 nately brittle, so that pieces of a large size cannot 
 be obtained. It is a grey marble, or fine lime- 
 stone, reflecting the red, green, and blue tints of 
 the opal, and almost with equal fire. These ex- 
 quisite colours arise from the laminar naker, or 
 what is commonly called mother-of-pearl, of a 
 kind of nautilus, of which fragments are imbedded 
 in this splendid substance ; their lustre being pro- 
 bably heightened by the fine reflections of iron, 
 observable in that of Elba, for veins of elegant 
 pyrites are not unusual in this stone. 
 
 The name of Lumachella, which in Italian sim- 
 ply implies snail or shell marble, now begins to 
 
 
MODE I. MARBLE. 417 
 
 be confined to this, and the following elegant 
 kind. 
 
 Among the numerous marbles discovered in the Lumacheiia. 
 ruins of Rome, is said to be the beautiful luma- 
 chella, ridiculously styled of Astracan, a name 
 which has embarrassed Patrin, who discovered 
 none such in the regions around that city, so cele- 
 brated in the Orlando Furioso, and the romances 
 of the middle ages. If he had looked into Ferber 
 or Born, he would have seen that it is a mere cor- 
 ruption, owing to the omission of one letter, the 
 Italian being Castracana, not Astracana. One 
 kind, according to Born, is called castracana della 
 castcllina. This is of a yellowish white, spotted 
 with little grey dots *. 
 
 The finest lumachella, reputed ancient, is of a 
 deep brown colour, and contains a number of 
 shells, which form little circles, or semicircles, of 
 a bright golden colour, or orange yellow, which 
 appear with the greater lustre from the contrast of 
 the base. This may be regarded as the most sin- 
 gular of all the marbles. Ferber also mentions 
 the following varieties : 
 
 This Castracan is the Castravan of Woodward and Da Costa : 
 the Khesroan of d'Anville. The mountains of Castravan extend 
 behind Tripoli in Syria. See Pococke, ii. 92 ; and Maundrel's 
 ""ravels. They are also famous for a raarlite slate, with impression* 
 f fish and sea-stars : Mode VII. 
 
 VOL. I. 2 E 
 
418 DOMAIN V. CALCAREOUS. 
 
 Greyish brown, with white transparent veins, 
 like agate. 
 
 The same, with rose-coloured stripes. 
 
 Brownish yellow, with small black shells. 
 
 With regard to the inferior kinds of conchitic 
 marble, they seem to have been little regarded by 
 the ancients. The masters of the world, whether 
 seated at Rome or Constantinople, continued for 
 ten or twelve centuries their preference of the 
 Phrygian, with crimson or lilac flowers ; the im- 
 perial red of Africa ; the green of Laconia ; and 
 the yellow of Nurnidia. Among the capital co- 
 lours, a blue alone was wanting; but it is also 
 unknown to us, and perhaps to nature, lazulite, 
 the sole rock of that colour, being only found in 
 detached masses ; a circumstance as unaccountable 
 as that there should be only one shrub with a blue 
 flower, and that in our climate confined to the hot- 
 house. 
 
 The artists and dealers at Rome, sometimes 
 with a view of distinction, and sometimes to in- 
 crease the price, may apply the name of antique 
 as jewellers do that of oriental, merely to the 
 more precious kinds. Such perhaps may be that 
 marble reputed ancient, and commonly styled at 
 f rnorto di Rome Panno di morto, or the funereal pall. It is 
 of the deepest black, sprinkled with white shells 
 like snails, each an inch or more in length, at 
 
MODE I. MARBLE. 419 
 
 distant and rather regular intervals. It is very 
 scarce, and deservedly in high esteem. The an- 
 cient occhio di pavone, or peacock's tail, is by 
 some called a conchitic marble, the shells forming 
 large circular and semicircular spots, red, white, 
 and yellow*. 
 
 In the modern kingdoms of Europe, as inferior 
 in taste as in power to the Romans, many kinds of 
 conchitic marble have been introduced into archi- 
 tecture. The pillars of the venerable cathedral English, 
 of Durham, a monument of the eleventh century, 
 are constructed of a black marble with white 
 shells, but both of a dull lustre, the quarries of 
 which are still known to exist at no great distance. 
 Of the black shell marble there are also tombs in 
 the abbey of Melrose, probably from the same 
 quarry with those of Durham. The marble of the 
 north of Scotland is chiefly primitive. 
 
 A fine black marble, with white shells, is found 
 near Bristol, where it is used for chimney-pieces. 
 A similar, it is believed, occurs in Derbyshire. 
 
 ' * Da Costa, p. 213, says the peacock's eye is a beautiful marble, 
 of a bright cinnabar colour, with spots and veins of milk white 
 spar : many of the spots form circles about the size of a sixpence, 
 filled with a red ground ; and which, from an imaginary resem- 
 blance, have conferred the name. It takes a high polish, but is 
 generally much cracked or flawed. It must not be confounded 
 with the pavonazzo, or purple. 
 
 2 E 2 
 
420 DOMAIN v. CALCAREOUS. 
 
 Purbeck boasts a marble, of whicbr the shells form 
 grey, blue, and white circles. 
 
 But the marble chiefly used in our ancient ca- 
 thedrals and churches, was that of Petworth in 
 Sussex, which is thus described by Woodward : 
 Petworth. Marble, from Petworth, Sussex. The ground 
 grey, with a cast of green. Tis very thick set in 
 all parts of it with shells, chiefly turbinated. 
 Some of them seem to be of that sort of river shell 
 that Dr. Lister, Hist. Cochlear. Angl. p. 133, 
 calls cochlea maxima , fusca sive nigricans, fas- 
 data. Several of the shells are filled with a 
 white spar, which variegates and adds to the 
 beauty of the stone. That spar was cast in the 
 shell before this was reposited in the mass of 
 marble, as is demonstrable from a view of this and 
 other like masses. Conf. Nat. Hist, of the Earth, 
 part IV. consect 2, p. 181, et seqq. second Edit. 
 This is of about the hardness of the white Ge- 
 noese marble. 
 
 " The slender round scapi of the pillars of the 
 Abbey Church in Westminster, and of the Temple 
 Church, are of this sort of marble. So likewise 
 are those of the Cathedral Church of Salisbury, 
 as I remember ; and my Lord Pembroke assures 
 me positively they are. Some persons that are 
 less skilful in these matters, fancy these scapi, 
 
MODE I. MARBLE. 421 
 
 that occur in most of the larger Gothick buildings 
 of England, are artificial ; and will have it, that 
 they are a kind of fusil marble, cast in cylindrick 
 moulds. Any one, who shall confer the grain of 
 the marble of those pillars, the spar, and the 
 shells in it, with those of this marble got in Sus- 
 sex, will soon discern how little ground there is 
 for this opinion: and yet it has prevailed very 
 generally. I met with several instances of it as I 
 travelled through England ; and had frequent op- 
 portunities of showing those who asserted these 
 pillars to be factitious, stone of the very same sort 
 with that they were composed of, in the neighbour- 
 ing quarries. Camden* had entertained the same 
 notion of those vast stones of Stone-Henge ; but 
 is fully refuted by Inigo Jones^" J 
 
 Da Costa mentions a black coralic marble, 
 from Wales, with madrepores an inch or two in 
 length, like half a crown when cut across. It is, 
 he says, very beautiful, and the tomb of Sir Tho- 
 mas Gresham, in the church of Great St. Helen's, 
 is formed of it. He confounds it with the Kil- 
 kenny marble, which he says is much used in Lon- 
 
 " * In his Britannia, p. 95. 
 *' t Stone-Henge restored, p. 33." 
 
 % Woodward's English Fossils, i. 20. The marble of Bethersden 
 in Kent was also noted. 
 
422 DOMAIN V. CALCAREOUS. 
 
 don, and which contains white sparry casts of 
 shells, both turbinated and bivalve*. 
 
 The Derbyshire marble, of a pale ash colour, 
 full of entrochi, was much used in London for 
 tables and chimney-pieces f. 
 
 Good marble is found in the side of Bowfell, in 
 the West Hiding of Yorkshire, being grey, with 
 entrochites : it is manufactured at Kendal, and is 
 in great demand at Manchester and Liverpool. 
 Bowfell is one of the highest mountains in En- 
 gland, and sends waters into both seas. It is 
 about thirty miles in circuit^. 
 
 French. France abounds in conchitic marbles. The 
 red of Givet, containing entrochi, rather belongs 
 to the Zoophytic structure. The department of 
 Aube shows a grey marble, almost formed of little 
 shells, and some large ammonites. Red, with 
 white circles, being transverse sections of shells, 
 from the neighbourhood of Brest. The white spots 
 in the beautiful red griottc sometimes wear a shelly 
 aspect . The greyish brown of Langres. Deep 
 
 * That supposed from Wales is in fact the same with that of 
 Durham, as appears from Gresham's tomb. 
 
 f Da Costa, p. 232, &c. 
 
 J Parkinson, Organic Remains, vol. ii. 
 
 Brard says that the red spots on the griotte are shells, of which 
 the outline is marked in black, p. 369 : this is from the department 
 of Herault. 
 
MODE I. MARBLE. 
 
 black, with white belemnites, from Narbonne. 
 The black marbles of Flanders. The pearl grey 
 of Nonette in Auvergne, in which the screw-shells 
 are changed into silex, but easily polished. 
 
 In Italy, some churches of Lucca, Pisa, and 
 Florence, are decorated with a brick red marble, 
 containing white ammonites. The modern ochio 
 di pavone, or peacock's tail, presents round spots, 
 whitish, bluish, or red, being shells cut across. 
 There is also a very pale yellow, with small shells, 
 changed into white transparent spar. 
 
 Spain offers the conchitic marble of Grenada Spain, 
 and Cordova, of a deep red with white shells; and 
 that of Biscay, of a deep black, with shells of a 
 splendid white. The pale yellow of Portugal, as 
 already mentioned, presents marine bodies. 
 
 The marbles of Swisserland, Germany, and the Germany, &c. 
 northern regions, often belong to this description ; 
 but if there were not some striking singularity, it 
 would be unnecessary to enter much into the spe- 
 cification. Those of Basel have astroites and 
 coralites ; of Brunswick, Franconia, &c. belem- 
 nites, ammonites, and cochlites ; of Sweden, ortho- 
 ceratites. 
 
424 DOMAIN V. CALCAREOUS. 
 
 STRUCTURE IV. ZOOPHYT1C. 
 
 Of this the ancients appear to have made no 
 use, though it sometimes presents varieties at once 
 uncommon and beautiful. A fine kind, easily had 
 of the marble-cutters at Paris, is of a chocolate 
 brown, with white madrepores of all sizes and 
 descriptions, beautifully variegated with grey and 
 OfCaen. re & This is the celebrated marble of Caen, in 
 Normandy, which may be called the madrepore 
 marble by way of eminence, and of which beauti- 
 ful tables and other ornaments abound in that 
 capital ; even those of the traiteur, in the garden 
 of the Tuilleries, being of exquisite elegance and 
 variety. 
 
 " The marble of Caen is of a dull red, and it 
 has large veins or branches of a grey or white co- 
 lour, which are solely composed of madrepores, 
 distinctly perceptible, either in the form of stars, 
 or that of diverging branches. This is then by 
 excellence a madrepore marble. N 
 
 " Its quarries are in the neighbourhood of Caen, 
 and although it be rather coarse and common, it 
 is much used at Paris, either for the tops of com- 
 modes, or for chimney-pieces, &c. There are 
 tables of it in most of the coffee-houses of Paris; 
 and it is known in commerce by the name of Caen 
 
MODE I. MARBLE. 425 
 
 marble. It somewhat resembles that of Lan- 
 guedoc; but is more cloudy, and less lively in its 
 colour, and does not take near so fine a polish."* 
 Another singular zoophytic marble occurs in 
 France, the ground being a wine red, with spots 
 of dull white and green; the latter being itself 
 calcareous, which is far from common. It is in- 
 terspersed with fragments of madrepores, and 
 other zoophytes, of a delicate bright red. It is 
 probably from the south of France. 
 
 The deep red marble of Givet, with light veins 
 or spots, contains white fragments of entrochi. 
 That of Charlemont is veined with white and red, 
 with white spots of madrepore. 
 
 The beautiful marble of Languedoc, or St. stBaume. 
 Baume, is of a fiery red, mingled with white and 
 grey, disposed in convolved zones. Some say that 
 the white and grey parts are formed by madre- 
 pores. The eight columns which decorate the 
 new triumphal arch, in the Carrousel at Paris, 
 are of this marble, which is one of the finest of 
 France. 
 
 The grey marble of Mons contains entrochi. 
 It is properly an orsten, as on friction it yields a 
 nauseous smell. The department of Calais fur- 
 
 * Brard, 362. That of Canne, here alluded to, is a griotte of a 
 deep red, spotted with white, according to Patrin. 
 
426 
 
 DOMAIN V. CALCAREOUS. 
 
 nishes a deep red marble, with grey spots, of 
 zoophytic remains. The marble of St. Anne, in 
 the neighbourhood of Namur, on a deep grey 
 base, presents white zoophytic spots : that of Thi- 
 laire is similar ; and that of Leff is pale red, with 
 white fragments of madrepores. 
 
 The starry marble of Italy is light grey or white, 
 and seems to be entirely composed of zoophytic 
 fragments. 
 
 Swiss. At Roche, a league beyond Aigle, is a quarry 
 
 of a handsome marble, veined with red, white, 
 grey, and black. It is polished on the spot, and 
 is much used at Geneva, and the Pays de Vaud ; 
 nor is it unknown even at Lyons. Polished tables 
 of this marble present beautiful madrepores, and 
 some shells, chiefly pectenites; but they have 
 assumed the nature and grain of the marble, and 
 the shell seldom or never appears in its original 
 form *. 
 
 * Sauss. 1092. 
 
MODE II. KONITE. 427 
 
 MODE II. KONITE. 
 
 There is a stone universally employed in Distinction, 
 architecture, and which may be regarded as 
 intermediate between marble and limestone. 
 It appears to have been the freestone of the Freestone, 
 middle ages, called ashler when only roughly 
 hewn ; and is also the freestone of Woodward, 
 and many other writers of mineralogy. Mr. 
 Parkinson has recently confirmed the justice of 
 this appellation, by informing us that " free- 
 stone is a compact limestone, of an earthy frac- 
 ture." 
 
 Yet many late writers have inaccurately ap- 
 plied the term freestone to a very different sub- 
 stance, using it as synonymous with sandstone* 
 chiefly indeed with a calcareous cement; though 
 it has also been extended to the argillaceous, 
 and even to the siliceous. The reason given for 
 the name is, that such a stone may be worked 
 in any direction ; nay, Doctor Kidd informs us 
 " that sandstones which yield readily to the 
 chisel, and hence called siliceous freestones, are 
 used in masonry." If the term were thus ex- 
 tended, it might also be applied to granite, which 
 is used in many countries for the commonest 
 
BOMAIN V. CALCAREOUS. 
 
 habitations. Even calcareous sandstone can 
 scarcely be called a freestone, as it often re- 
 quires to be placed in the original direction of 
 its layers in the quarry, else it will moulder in 
 the air; which is also the case with some lime- 
 stones employed in the public buildings at Ox- 
 ford, and which therefore can scarcely be called 
 freestones. 
 
 The freemasons of the middle ages, who ap- 
 pear to have been the successors of the Knights 
 Templars, from their allusions to the temple, 
 the military tinge of their mysterious rites* 
 which formerly excited the jealousy and revenge 
 of monarchs, and other circumstances,- appear 
 to have applied the name freestone from a yet 
 more delicate and appropriate circumstance* 
 namely, that it might be wrought into orna- 
 ments of the most minute description, such as 
 are observable in the cathedrals and other public 
 buildings, not to mention the crosses, tombs, and 
 other monuments, of the middle ages, which 
 could never be imitated in any sandstone. The 
 little fleurets, and other miniatures, which we 
 admire in the tombs and buildings of that period, 
 are sculptured on a stone of the finest grain, 
 and at the same time of a softness most easily 
 obedient to the chisel; qualities which, if found 
 in any sandstone, it would soon moulder, and 
 
MODE Ilk KONITE. 
 
 the labours of the sculptor would scarcely sur- 
 vive his own century*. 
 
 The original acceptation of the term being Name, 
 thus lost, it has of course become vague, and 
 ought, as in many other instances in the pro- 
 gress of mineralogy, to be exchanged for an- 
 other, strictly appropriated, and which cannot 
 be abused. As this rock may be regarded as 
 the noblest of the common limestones, and 
 though Greek etymons have become universal iit 
 the science, yet the Greek words representing 
 limestone and silex have not hitherto been ad- 
 mitted, the appellation of Konite is proposed 
 from Kova, which is used repeatedly for lime by 
 Theophrastus, especially in the last chapter of 
 his book on stones |. 
 
 Konite being merely a compact limestone, of Characters, 
 an earthy fracture, sometimes coarse and some- 
 times finer, for its other characters those of lime- 
 stone may be consulted. There is sometimes a 
 slight admixture of silex, often of argil, rarely of 
 magnesia, which however has been found by 
 chemical analysis in some kinds, as those em- 
 ployed in Westminster Abbey and the Cathedral 
 
 * Calcareous sandstone of course leaves much sand in the nitrous 
 acid ', while konite produces none, or, in some kinds, a very small 
 quantity. 
 
 t It might also be called Oikite, from its use in building. T/ravoc, 
 another term for lime, has been oddly applied to titan t a metal. 
 
430 
 
 DOMAIN V. CALCAREOUS. 
 
 of York; and that fine earth must of course im- 
 
 - 
 
 part some of its usual qualities, of unctuous soft- 
 ness and durability*. By some little research it 
 might probably be discovered from what quar- 
 ries the stone used in our cathedrals, and other 
 ancient buildings, was procured. One kind was 
 Of Caen, even brought from Caen in Normandy, merely, 
 as would seem, because it was known to the 
 Norman conquerors. It is said to appear in the 
 posts and lintels of the castle at Rochester, and 
 in many other places; but the name of Caen 
 stone is often erroneously applied, as for instance 
 in the abbey of St. Alban's; while we know, 
 from authentic records, that the stone chiefly 
 Tottenhoe. employed was from the quarries of Tottenhoe, 
 in Bedfordshire. Not contented with the ma- 
 jestic appearance of konite, or genuine free- 
 stone, on whose soft tinge of brownish white the 
 eye reposes with more pleasure than on the glit- 
 tering splendour of marble, our ancestors in- 
 creased the magnificence with single or grouped 
 pillars of Petworth marble, drawn from quarries 
 now unknown, near the town of that name in 
 Sussex. This marble is often ignorantly called 
 Purbeck, while it is totally different both in co- 
 lours and composition. The structure of the 
 
 * See the Mode Magnesian Limestone, Domain IV. 
 
MODE II. KONITE. 43 1 
 
 Petworth marble is even singular, as the shells, 
 which are very small, seem changed as it were 
 into drops of spar and marble; and the prevail- 
 ing tints are a faint green and reddish brown ; 
 while in the Purbeck the tints are a bluish grey 
 or ash, and a dull yellow or fawn colour; and 
 the shells are marked by little black lines. These 
 pillars of Petworth marble adorn the cathedrals 
 of Canterbury and Salisbury, the Abbey Church 
 of Westminster, and that of St. A 1 ban's ; not to 
 mention the Temple church, and Great St. He- 
 len's, in London ; and probably many others 
 might be noted. The contrast of this beautiful 
 marble with the konite of the rest of the edifice 
 must have been striking and magnificent; but 
 at present all is equally covered with a white or 
 yellowish wash, so as to recall the memory of 
 the whited sepulchre, applied in scripture to a 
 hypocrite; while the walls ought only to be 
 cleaned, and the pillars polished anew, as in 
 some sacred edifices of the Continent. 
 
 At present the most remarkable konite used Portland 
 in the southern parts of England is that of Port- 
 land, which is thus described by Dr. Wood- 
 ward: 
 
 " Stone out of the great quarry of Portland, 
 of a pale or whitish colour, composed of nu- 
 merous small roundish grains, not unlike the 
 
432 DOMAIN V. CALCAREOUS. 
 
 smaller ova of fishes. They split in the cutting 
 of the stone ; so that it is capable of being 
 brought to a surface, very smooth and equal. 
 Besides, this and all like sorts of stone that are 
 composed of granules, will cut and rive in any 
 direction: as well in a perpendicular, or in a 
 diagonal, as horizontally and parallel to the site 
 of the strata. 'Tis for this reason that they have 
 obtained the name of freestone. Then these 
 bear the injuries of the weather equally and in- 
 differently in all positions : whereas all the stone 
 that is slaty, with a texture long, and parallel to 
 the site of the stratum, will split only length- 
 ways, or horizontally; and if placed in any 
 other position, 'tis apt to give way, start, and 
 burst, when any considerable weight is laid- 
 upon it. Which inconvenience the Portland 
 stone being not liable to, cutting freely, and 
 being of a colour very good and agreeable, 'tis 
 made use of for the better buildings and works 
 about London."* 
 
 Da Costa calls the Portland stone an alkaline 
 sandstone; and, with equal error, adds that 
 sandstones have obtained the name of freestones 
 because they were cut in any direction. He 
 subjoins some account of the Surry stone of 
 
 * Woodward's English Fossils, 1729, i. 17* 
 
MODE II. KONITB. 
 
 Ryegate, and Godstone; which last is said to 
 have received its name because it was often used 
 in churches. They seem by his account to be 
 coarse sandstones with mica, now chiefly used 
 for ovens and hearths, and the like purposes. 
 
 Konite is by the French called pierre de tallle 9 other kinds. 
 moellon, &c. The Italian maciggo seems an 
 argillaceous limestone with a little mica ; while 
 the travertine used in the ancient and modern 
 edifices of Rome strictly belongs to the cal- 
 careous tufas, under which it will be described. 
 The building stone chiefly used at Edinburgh, 
 especially in the beautiful new city, is from the 
 quarry of Craigleith, and is said to be an argil- 
 laceous limestone, perhaps sandstone, with black- 
 ish veins. The ancient Romans, whose buildings 
 are alike distinguished by magnificence and du- 
 rability, chiefly, like their successors, employed 
 
 the travertino, which abounds on the banks of 
 
 t 
 
 the river Anio, and is reproduced by its depo- 
 sitions. To the lasting nature of this stone, and 
 of the mortar mixed with puzzolana, which also 
 abounds in the neighbourhood, that is, to cir- 
 cumstances merely accidental, may the preserva- 
 tion of the common sewers, and other works of 
 surprising antiquity, be ascribed. But the use 
 of konite in building ascends even to the earliest pyramids. 
 ages, the pyramids of Egypt being constructed 
 VOL. i r 2 F 
 
434? DOMAIN V. CALCAREOUS. 
 
 with this material ; which, as already mentioned, 
 seems the lapis Troicus of the ancients. The 
 Egyptian konite, which forms a whole chain of 
 mountains, extending from Cairo and the front 
 of the pyramids, far to the south, is sometimes 
 Simple, and sometimes contains shells, chiefly 
 nummulites, which, when cut across, resemble 
 grains of wheat or barley; whence the fable of 
 the ancients, that the workmen employed re- 
 ceived such vast quantities of grain, that much 
 of it was left and petrified. Some of the most 
 ancient edifices of Persia, Greece, and Italy, 
 are also built with konite; but the ruins of Poes- 
 tum, and the temple of Agrigentum, are of cal- 
 careous tufa. 
 
 In general, writers on mineralogy, while they 
 are often occupied with laborious trifles, seem 
 strangers to the chief object, which is the utility 
 of the substances. Brongniart, the director of 
 the porcelain manufacture at Sevres, and accus- 
 tomed to consider objects as adapted to the pur- 
 poses of human life and manners, has sometimes 
 deviated into utility; and his account of the 
 konite thus becomes interesting. 
 Brongniart's This substance is the chaux carbonatfc 
 
 account. 
 
 grossiere of Haiiy, and is commonly called pierrc 
 a bdtir, pierre de taille, and moellon. The tex- 
 ture is often loose, and the grain coarse. 
 
MODE II. KONITE. 435 
 
 is easily cut with any sharp instrument, but 
 does not receive any polish. The fracture 
 is granular and dull; as are also the colours, 
 which are white, grey, and Isabella yellow. 
 The kinds differ greatly in the fineness of their 
 grain, in colours, and duration ; but these dif- 
 ferences only influence their use for distinct 
 purposes, and do not depend upon their original 
 positions. 
 
 " Some have a very fine grain, and a whitish 
 colour; but have little hardness, and cannot be 
 employed except in sculpture. Such are the 
 stone of Tonnerre, in the department of Yonne; 
 and one of those quarried at Nanterre, near 
 Paris; not to mention other examples. 
 
 " Others have a coarser grain, while their 
 colour is yellowish ; and they are tender and 
 friable. Such are the stone of Conflans Ste. Ho- 
 norine, near Paris, of which the beds are some- 
 times two yards in thickness ; and that of St. 
 Leu and Trossy, in the department of Oise; the 
 beds of the latter being only a yard thick. 
 
 " In fine, others, though of a very loose tex- 
 ture, and of a very coarse and visible grain, 
 although even composed of calcareous sand and 
 agglutinated fragments of shells, &c. possess 
 nevertheless great hardness and solidity; such 
 as the stone of Saillancourt, near Pontoise, the 
 
 2 F 2 
 
436 DOMAIN V. CALCAREOUS. 
 
 beds of which are so thick that the quarry seems 
 cut into one mass. It is reserved for bridges 
 and highways*. 
 
 " This rock seems exclusively to belong to 
 the depositions of coarse sediment, which are 
 far from the primitive mountains, and which 
 approach the alluvial territory. Although it 
 present beds of great thickness and extent, it 
 never forms mountains, but only round hills, of 
 which the skirts sometimes display pretty high 
 precipices. It forms the base of many plains, 
 such as in France the plains to the south of 
 Paris, those in the neighbourhood of Caen, and 
 others. 
 
 " The beds of this rock are very distinct, 
 being horizontal, rarely inclined, never convo- 
 luted nor bent, and commonly divided by clay, 
 marl, or sand. There are sometimes seen, be- 
 tween them, infiltrated geods of quartz and cal- 
 careous spar, as at Neuilly, near Paris ; or thin 
 layers of keralite or flint, interspersed with 
 shells, as at St. Cloud and Sevres. 
 
 " These beds vary much in thickness ; and it 
 may be observed, that they are thicker in the 
 soft kinds than in the hard. The latter is often 
 in such thin layers that it is used in some coun- 
 
 * One stone in the parapet of the celebrated bridge of Neuilly is 
 thirty-four feet in length. P. 
 
 
MODE II. KONITE. 437 
 
 tries, as in the Cote d'Or, near Dijon, instead of 
 slates, to cover the houses ; and these flat stones 
 have received the absurd name of lava. This 
 limestone is often an impure mixture of calcareous 
 sand and fragments of shells ; and sometimes con- 
 tains entire shells, which are generally of the kind 
 called Littoraly because they are found near the 
 shores of the sea*. The limestone of the neigh- 
 bourhood of Paris is full of great numbers of 
 these shells, called cerites, or screws, which are 
 sometimes so abundant, that the stone seems 
 entirely formed of them. There is found at 
 Weissenau, near Mentz, a bed of limestone, 
 which is entirely composed of little limnes^, of 
 the size of a grain of millet seed. 
 
 " There are neither veins nor beds of metals 
 in this limestone, which only contains oxyd of 
 iron, either argillaceous or calcareous, in beds or 
 in heaps; it is also said that carbonate of zinc 
 has been found in it; but of this there is no 
 proof. Coal is never found in this kind of lime- 
 stone ; even silex is rare; and sulphurets of iron 
 are excluded. 
 
 * It may be observed in the catacombs under the city of Paris, 
 that the shells form layers between the beds, like flint in chalk : so 
 that the depositions must have been at successive periods. P. 
 
 f The Linnaean name is wanting. 
 
438 DOMAIN V. CALCAREOUS. 
 
 " But if the differences between the compact 
 and this kind are of little consequence, the geo- 
 logical differences are numerous and important. 
 
 " This limestone is employed in architecture ; 
 the solidity of some of its varieties, and the ease 
 with which it is wrought, giving it great advan- 
 tages. It is called pierre de faille when it is in 
 large masses, and moellon when they do not ex- 
 ceed four cubic feet. 
 
 " It is unequally dispersed, being rare in 
 England, and common in France, especially in 
 the environs of Paris, chiefly to the south of that 
 city, from Sevres to Gentilly. Its beds, which 
 are horizontal, extensive, thick, and continuous, 
 are situated between chalk, which it covers, as 
 may be observed at Meudon, and gypsum, 
 which covers it in some parts. It is separated 
 from the chalk by a bed of bluish potters' clay. 
 To different parts of its beds distinct names have 
 been applied, according to their quality, and 
 the uses for which they are destined. That 
 which is of a fine grain and compact texture is 
 called pierre de liais*: it may be cut in sharp 
 squares, and resists the weather; the thickness 
 of its beds seldom exceeds eight inches. The 
 
 * In the eommon dictionaries, liais, and pierre de taille, are 
 translated freestone. Sandstone is gres. 
 
MODE II. KONITS. 
 
 pierre de rocke is as hard as the liais> but porous 
 and full of shells; thickness of the beds about 
 two feet. The lambourde is a tender stone with 
 a coarse grain ; the beds being about three feet. 
 These three qualities, and others which we omit, 
 are often found in the same quarry. 
 
 " The quarries which furnish the best build- 
 ing stone used at Paris, are those of St. Norn in 
 the park of Versailles; La Chaussee, near St. 
 Germain en Lay e; Poissy; Nanterre; the three 
 last yielding stones almost as beautiful as the 
 liais $ of Saillancourt, near Pontoise; of Con- 
 flans Ste. Honorine; this quarry yields the finest 
 tender stones, sometimes seven or eight feet in 
 thickness; of St. Nicolas, near Senlis, which is 
 a liais ; of St. Leu and Trossy, department of 
 Oise, which is a soft stone". 
 
 " The soft kinds are sawed dry, the saw hav- 
 ing teeth as that used for timber. The hard 
 kinds are divided by a saw without teeth, by 
 the means of water and pounded sandstone. 
 But that they may not decompose in the air, 
 they must be placed according to their original 
 beds, for very few will last in the opposite po- 
 sition. Several porous and tender kinds are sub- 
 ject to split by frost. The weight varies accord- 
 ing to their quality; thus the hard stone of 
 
440 DOMAIN V. CALCAREOUS. 
 
 Meudon is to the tender stone of St. Leu as 24 
 to 17- This stone being generally impure yields 
 a bad lime."* 
 
 This important rock may be divided into two 
 structures; the simple or entire, and that min- 
 gled with shells, or the Conchitic. No example 
 of the Zoophytic seems to occur in this kind of 
 limestone, which is of recent formation. 
 
 STRUCTURE I. ENTIRE. 
 
 Aspect 1. Fine-grained, From Egypt. 
 From Caen, Tonnerre, and Nanterre, France. 
 From Tottenhoe, Bedfordshire. 
 From Portland. 
 
 Aspect 2. Coarse. This is often found in the 
 same quarries. 
 
 From Saillancourt, near Pontoise, in France. 
 
 From Portland. 
 
 From Scotland. 
 
 Yellow, from Lyons, the chief building stone 
 there used. 
 
 * Brongniart, i. 204. 
 
MODE III. LIMESTONE. 441 
 
 STRUCTURE II. CONCHITIC. 
 
 Aspect 1. With nummulites, from Egypt. 
 
 With ceriteSj from Paris. 
 
 With various shells, from the vicinity of Bath. 
 
 The pierre de tattle used at Marseilles is a con- 
 chitic limestone, of which the quarries are at Cape 
 Couronne *. 
 
 MODE III. LIMESTONE. 
 
 The characters of this rock will be given in 
 some distinct Structures. The combination, as 
 of the former Modes, is chiefly lime and car- 
 bonic acid, about 40 of the latter to 50 of the 
 former; whence the term carbonates of lime. Carbonates of 
 But the Modes differ in minute particulars, as 
 already mentioned. 
 
 This useful rock abounds in most countries. 
 It is generally burnt to make lime and mortar; 
 but is also employed in building, and sometimes 
 in making roads, though the siliceous substances 
 be more durable and proper for the latter pur- 
 >ose. 
 
 * Sauss. 1517. 
 
442 DOMAIN V. CALCAREOUS. 
 
 ^ * s ^ en ^ u ^ ^ marme shells, and lies super- 
 incumbent upon slate or sandstone : some have 
 even confounded compact limestone with sand- 
 stone. Patrin has observed that the calcareous 
 deposition was more abundant on the summit of 
 mountains than on their sides, because the slopes 
 scarcely received, on a hundred fathoms of sur- 
 face, the same quantity with ten fathoms of the 
 level summit*. Hence the latter is sometimes 
 insulated and separated from that of the plains, 
 because the thin beds on the sides of the moun- 
 tains were worn down by the waters; and as the 
 summits of the mountains attract clouds, so un- 
 der the primeval waters they must have attracted 
 the various substances contained in them. 
 
 The calcareous chain of the Pyrenees is far 
 higher than the granitic, containing marine 
 shells, and sometimes assuming the combination 
 called orsten, or swine-stone, a sort of coarse 
 fetid marble. Such is the summit of Mont 
 Perdu, a calcareous colossus, about twenty miles 
 in length, and four or five miles in breadth, with 
 an elevation of 10,500 feet above the level of 
 the sea. 
 
 Bridas. Sometimes the calcareous beds on the steep 
 slopes have rolled down, and the broken frag^ 
 
 * Min. iii. 16. 
 
MODE III. LIMESTONE. 443 
 
 Hients have afterwards been united into bricias, 
 which are very common in this kind of rock. 
 
 In a softer state these beds have been con- Contorted. 
 volved, in various contrasted forms. " Saussure 
 cites many examples of these heaps of calcareous 
 beds, which are contorted in such a manner as 
 evidently to show that they have been bent by 
 the effect of the force which parts of the same 
 beds, in a higher situation, have exerted against 
 them. 
 
 " Among others, he observed this effect in 
 three different places, on the borders of the lake 
 of Lucerne. The one near the mouth of the 
 Reuss : * The bent beds/ says he, ' are of a grey 
 compact limestone > they rise from the lake in 
 a vertical position ; they then bend towards the 
 south-west, and on that side become concave. 
 To the north-east, on the side of their convexity, 
 a hollow presents itself. 
 
 ' On closely examining these beds, they are 
 found to be very much broken, and appear to 
 have been so in the act of bending, and even by 
 the force that bent them.' 
 
 " The second place is half a league to the 
 northward of the preceding, likewise on the bor- 
 der of the lake, of Lucerne, on which Saussure 
 sailed : it is a mountain called Axenberg. c From 
 the summit to the foot of this calcareous moun- 
 
444 DOMAIN V. CALCAREOUS. 
 
 tain beds are observed in the form of an S, com* 
 pressed, or of which the bendings are very 
 strongly marked. These S's are often repeated, 
 sometimes in contrary directions, and masses of 
 rocks are found between them, whose stratifi- 
 cations are not distinct. When these contorted 
 beds are closely observed, it is found that they 
 are often broken in the strong curvatures ; and 
 this proves that they were not formed in that 
 . position/ 
 
 cc The third place is opposite the preceding, 
 on the other side of the lake : c It is a mountain 
 in which the beds, which are nearly horizontal 
 below, turn up above and form a C, whose con- 
 cavity looks to the N. N.E. : on the left, or to 
 the S. S.W. of the C, there is a large hollow; 
 and what is most remarkable is, that the beds 
 which adjoin the lower branch of the C extend 
 themselves to a great distance, forming a moun- 
 tain with regular and horizontal beds.' 
 
 " From these facts Saussure concludes that 
 these dislocations of beds are produced by a re- 
 foulement, or repressure, which has folded them 
 over each other."* 
 
 Calcareous rocks seem to be comparatively 
 rare in Africa, and even in Asia. As layers of 
 
 Patrin iii. 
 
 
MODE III. LIMESTONE. 445 
 
 flint are found in chalk, so layers of chert, or ke- 
 ralite, appear in limestone ; while Lydian stone, 
 and siliceous schistus, sometimes intersect the 
 primitive calcareous rock. 
 
 Limestone often presents mural precipices, as 
 in the Pyrenees, and sometimes in forms ap- 
 proaching the artificial, as in the circus, towers, 
 and cylinder of Marbois. The picturesque ap- 
 pearances of Chedder cliffs are on a smaller 
 scale. In the chain of Jura, and in the Py- 
 renees, calcareous mountains have been ob- 
 served, with exterior arrects of 40 or 45 degrees, 
 while the interior become more and more verti- 
 cal. Palassou and Pasumot, in their descrip- 
 tions of the Pyrenees, have observed a mountain 
 of limestone, formed of oval and circular concen- 
 tric layers, which present a most singular ap- 
 pearance. On a smaller scale, as in pisolites 
 and sinapites, limestone often affects the orbi- 
 cular form. 
 
 Saussure informs us, 347, that the chain of 
 Jura is calcareous, with the exception of some 
 few spots, covered with calcareous sandstone. 
 In 1937 he remarks contorted beds of compact 
 limestone, which he says of course must be sedi- 
 mental, not crystallised, and must have been 
 deranged by a refoulement* Nor has the re- 
 
446 DOMAIN V. CALCAREOUS. 
 
 rnarkable intermixture of compact limestone 
 with granular, escaped this great observer*. 
 
 The singular rock which contains pholades, 
 or sea-dates, is a blackish argillaceous limestone, 
 rather of a soft consistence f. 
 
 Primitive. That granular limestone is primitive has been 
 long allowed. Among many other remarkable 
 mountains of this stone, the stupendous heights 
 of Finster Aar Horn, Yungfrau Horn, and 
 Shreck Horn, or the Peak of Horror, in Swisses 
 land, deserve especial commemoration. Saus- 
 sure has long since observed, that it often pre- 
 sents lofty spires, like granite; and being a 
 manifest deposition, must evince that granite 
 is so likewise, It appears between layers of 
 mica slate and gneiss, as schistose siderite; and 
 alternates with common slate. Primitive lime- 
 stone is commonly white, dark iron grey, or red- 
 dish brown, and is not always granular, being 
 sometimes compact. It sometimes supplies the 
 place of quartz in mica slate, and sometimes of 
 felspar in granitoid, and a rock of the gneiss 
 
 * Sauss. 2226. 
 
 t Id. J356. On the coast of Aunis, near Rochelle, little oysters 
 called gryphites are forced into the mud by the sea. The whole 
 ^oon becomes a hard stone, and is called the shell-stone of Aunis. 
 Mem. Acad. de Rochelle, tome iii. 
 
 . 
 
MODE III. LIMESTONE. 447 
 
 structure. It is rarely metalliferous, but in Si- 
 beria it presents rich mines of copper, and in 
 South America veins of gold and silver. It is 
 remarkable, that in limestone the shells retain 
 their original form, while in clay slate they are 
 compressed ; a circumstance ascribed to the 
 great subsidence of the latter. Caverns are sel- 
 dom found except in limestone, the rock being 
 commonly eroded by a stream of water. 
 
 The Wernerians regard limestone as of three Formations, 
 formations; the primary, the transitive, and the 
 floetz, flat or horizontal. The second often 
 contains coralites and madrepores; but Faujas 
 showed a madrepore in Carrara marble, which 
 is esteemed primitive. 
 
 Limestone seldom or never occurs pure, there 
 being generally a small admixture of argil, 
 sometimes of silex, sometimes of iron. When 
 there is manganese it forms a more tenacious 
 mortar. 
 
 STRUCTURE I. GRANULAR. 
 
 Aspect 1. Common. The characters mostly 
 Correspond with those of marble ; but the mode 
 of combination must vary, as it is not capable of 
 so fine a polish. 
 
 The colours are white, grey, black, reddish, and 
 
448 DOMAIN. V. CALCAREOUS. 
 
 yellowish. A green tint may be suspected to in- 
 dicate magnesia. 
 
 Granular limestone often belongs to the noble 
 kinds or marbles; it is also often found more 
 soft, light, and coarse, when it falls into this di- 
 vision. 
 
 Grey granular limestone, with calcareous spar, 
 from Lusatia. 
 
 The same, mixed with slate, from Saxony. 
 
 Reddish brown granular limestone, with slate, 
 from the same. 
 
 White granular limestone, from Stiria. 
 
 White sparry limestone, in thin shining span- 
 tablets? ^ es ? fr m China. " There are brought from 
 China," says Born, " tablets of an oblong square 
 form, often marked with Chinese letters ; of a dull 
 polish, and sold as artificial, under the name of 
 rice stones, being regarded as composed of rice 
 reduced to a paste; but the external characters 
 and chemical analysis demonstrate that it is only 
 a sparry limestone, cut in these forms." A like 
 fabulous idea concerning rice has been entertained 
 with regard to iconite. 
 
 Argillaceous limestone, which naturally splits 
 into lentiles, convex on both sides, which might 
 seem to be a bricia were not the paste absolutely 
 homogenous. Sauss. 1377. 
 
MODE III. LIMESTONE. 449 
 
 A limestone, containing large shells full of 
 sand. Sauss. 284. 
 
 Aspect 2. Micaceous. Primitive granular lime- 
 stone is often interspersed with mica, and some- 
 times with orbicular crystals of quartz. It has 
 already been observed, that the mere mixture of 
 mica can never be understood to alter the deno- 
 mination of the stone. 
 
 Micaceous limestone, from the Alps. 
 
 The same, from the Grampian mountains, in 
 Scotland. 
 
 The substance called Cipoline marble is often- 
 so coarse as rather to belong to this division. 
 
 Limestone, with nodules of "mica and of sand, 
 from the Pyrenees. 
 
 A micaceous limestone, in which the mica is so 
 abundant that the calcareous mixture is scarcely 
 distinguishable. Sauss. 1 8 1 J . I 
 
 STRUCTURE II. COMPACT. 
 
 Texture, compact, generally massive and earthy, Characters, 
 sometimes schistose. 
 
 Hardness, from the gypsic to the marmoric. 
 Fracture, fine scaly, sometimes large and flat 
 :onchoidal, sometimes uneven. Fragments, arnor- 
 }hous, rather sharp. 
 
 VOL. i. 2 G ' 
 
4,30 DOMAIN V. CALCAREOUS. 
 
 Lustre, dull. Opake ; but often translucent on 
 the edges. 
 
 The most common colour is grey, of various 
 tints, and yellow of different shades. It is often 
 veined and spotted in various forms. 
 
 Primitive compact limestone, from the Alps. 
 The same, from the Grampian mountains, Scot- 
 land. 
 
 Primitive limestone, with garnets, from the Py- 
 renees. 
 
 Grey compact limestone, intersected with gra- 
 nular, from the Alps. 
 
 Black compact limestone, intersected with chert, 
 from Derbyshire. 
 
 The same, with spots of bitumen. The black 
 colour often arises from the bitumen, as appears 
 from the stones becoming white when calcined. 
 
 Limestone, of a dull white colour, from Port 
 Rush, in the north of Ireland. This stone, which 
 has sometimes been called chalk, supports the 
 celebrated basaltic columns around the Giants* 
 Causey. It abounds with fossile remains, and no- 
 dules of dark flint: for the depth of sixty feet 
 under the basaltin it is impregnated in a singular 
 manner with small particles, mostly oval, of the 
 basaltin; and, from the mixture of colour, is vul- 
 garly called mulatto stone. A most singular ge- 
 ological fact. 
 
MODE III. LIMESTONE. 451 
 
 Mr. Kirwan mentions a sky-blue limestone, 
 from Aberthaw, in Glamorganshire. But this, 
 like the blue marble of Narbonne, or the blue tur- 
 quin, appears to be only grey. Dr. Kidd de- 
 scribes it as light blue, or grey ; and says, that it 
 is common in Somersetshire, and that it only 
 occurs in the form of shingle, or large pebbles, on 
 the sea shore at Aberthaw. This colour seems to 
 indicate a mixture of iron ; and such limestones, 
 when calcined, become of a buff colour, and fur- 
 nish a harder mortar than any other. 
 
 STRUCTURE III. CONCHITIC. 
 
 Many of this description belong to the noble 
 division, or marbles, not to mention the konites ; 
 but many also are of a soft and coarse nature, 
 whence they fall under this Structure. The lime- 
 stone containing shells is generally grey, but some- 
 times dull white, or brown. Sometimes even 
 bones are found in limestone, and in marble ; and 
 Faujas, as already stated, has recently observed a 
 remarkable example near Verona, where a fine 
 black marble, containing petrified bones, is worked 
 into large columns. Karsten, as quoted by Gme- 
 lin, has also mentioned a limestone, containing 
 bones, which is found at Erfurt; but the piece* 
 seem to be small and detached. 
 
 2 G2 
 
452 DOMAIN V. CALCAREOUS. 
 
 shells. To enumerate all the shells contained in lime- 
 stone would be infinite ; nor have such as occur 
 in rocks been hitherto carefully distinguished from 
 such as are found detached and scattered. It will 
 be sufficient for the present purpose to mention 
 such as are generally inherent in large masses of 
 limestone, konite, or marble ; thus forming, as it 
 were, a constituent part of these rocks. This 
 subject will be further illustrated by the plates. 
 
 It has been observed as unaccountable, that 
 the shells of those fish which are called Pelasgic 
 or Oceanic, as inhabiting the unfathomable depths 
 of the ocean, are often found at the greatest ele- 
 vations ; while those which approach the less pro- 
 found depths, and even the shores, are rather 
 found on the skirts and lower hills. If this ob- 
 servation be exact, the explication seems very 
 difficult, except perhaps that, under the chaotic 
 waters, the proper purity and temperature to sup- 
 port animal life could only be found at such ele* 
 yations. 
 
 The shell venerated as the most ancient, and 
 unknown in modern conchology, is that called 
 the Cornu Ammonis, or horn of Jupiter Ammon, 
 from the twisted horn, a symbol of power in the 
 images of that deity. In the middle ages they 
 were supposed to be petrified serpents, and some- 
 times fraud has cut out heads, being esteemed 
 
 
MODE III. LIMESTONE, 453 
 
 pious memorials of the miracles of saints. If they 
 at all exist at present, they are said to be found 
 microscopic in the Adriatic sea; but a contorted 
 species of nautilus has often been confounded 
 with Cornu Ammonis. The petrified are styled 
 Ammonites, the Greek termination in this and 
 the other shells marking their stony nature. Am- 
 monites occur of all sizes, from half an inch in 
 diameter, as those which form the singular Dor- 
 chester marble, to six feet, or the size of a coach- 
 wheel, as some have been found immersed and 
 converted into chalk at Margate. 
 
 The nummulites, or porpites, occur in the lime- 
 stone of Egypt and of France, being thin shells, 
 or rather movable opercules or covers to protect 
 some shell-fish. Belemnites*, another embarrass- 
 ing form, are generally found detached. Entro- 
 chites, or joints of the sea-star, are very common. 
 The encrinites, other joints, resemble lilies. 
 
 To proceed to the UNIVALVE shells : nautilites 
 abound in many limestones and marbles; and 
 sometimes retaining their original lustre, impart 
 
 * Perhaps these may be spines of a large pelasgian sea-urchin. 
 The porpite has at last been observed alive in the South Sea. See 
 the curious plates to the voyage of Peron, Paris 1808, 4 to. ; where 
 the rich and interesting delineations of the zoophytes and mollusks 
 are very new and striking. 
 
454 DOMAIN V. CALCAREOUS. 
 
 singular beauty to the opaline marble of Ca- 
 rinthia. 
 
 Lituite. 
 
 Orthoceratite. 
 
 Conite. 
 
 Buccinite (Trumpet). 
 
 Bullite or Globosite. 
 
 Turbinite (Screw-shell). 
 
 Dentalite. 
 
 Patellite. 
 
 Cochlite (sea-snail). 
 Among the BIVALVES : 
 
 Solenite (Razor-sheath). 
 
 Tellinite (Limpet). 
 
 Dionite (Venus) Dione. 
 
 Aphrodite and Hysterolite. 
 
 Chamite (Clam). 
 
 Pectenite (Scallop). 
 
 Ostracite (Oyster). 
 
 Anomite (Gryphite). 
 
 Mytelite (Muscle. Mya,)- 
 
 Pinnite (Naker). 
 
 The chief MULTIVALVE shell observed in a 
 state of petrifaction is Lepadite, or Balanite. 
 
 Several crabs, &c. are discovered apart : and a 
 beautiful little tortoise in flint was found by my 
 friend Mr. Knight, upon his estate of Milton, in 
 
MODE III. LIMB3TONE. 455 
 
 Cambridgeshire, being, it is believed, an unique 
 example. 
 
 Echinites singularly abound in the chalk-pits of 
 England, with cockles, &c. ; but they are easily 
 separated, and of course foreign to the present 
 purpose. 
 
 Limestone, with ammonites, from Dorsetshire. 
 
 With belemnites, Thuringia. They may per- 
 haps have been mistaken for bones. 
 
 With orthoceratites, Erfurt. 
 
 With nautilites, Upper Austria. 
 
 With strombites, Jena. 
 
 With cochlites, Norway. 
 
 With chamites, Mont Martre. 
 
 With gryphites, Alsace. 
 
 Numerous other examples might be added, 
 i 
 
 STRUCTURE IV. ZOOPHYTIC. 
 
 Zoophytes, including the mollusks, also abound 
 in common limestone. They are of many varie- 
 ties; as the turbinated, the porpite, the fungite, 
 the astroite, &c. Among them may also be 
 classed the milleporite, the celleporite, the entro- 
 chite, either in many or single joints, and of several 
 varieties, the gorgonite, the coralite, and the en- 
 crinite. The trochite is a word used by some for 
 single joints of the entrochite, which can scarcely 
 
456 
 
 DOMAIN V. CALCAREOUS. 
 
 be distinguished from those of the encrinite, rarely 
 marked by the lily at the summit. 
 
 Limestone, with nummulites, from Egypt. 
 
 With entrochites, Derbyshire. . 
 
 With madreporites, from Gothland. 
 
 Numerous other examples may be added, from 
 all countries ; exclusive of the mere calcareous 
 petrifactions, which are found slightly adherent 
 or apart. 
 
 STRUCTURE V. PISOLITE. 
 
 This kind is so called from its appearance, 
 resembling conglomerated peas; and is chiefly 
 brought from Carlsbad in Bohemia, where it con- 
 stitutes a large bed. It is of a yellowish white ; 
 and the imaginary peas are in elegant concentric 
 layers of white and brown, formed around a grain 
 of sand, like pearls in the shell. Cronstedt has 
 with some propriety ranked it among the sinters 
 or depositions, 
 
 STRUCTURE VI. SINAFITE. 
 
 In this the orbicular accretions are smaller 
 than in the former; the structure quite distinct, 
 and more compact. The name is derived from 
 mustard seed. Some call it meconite, from the 
 seed of the poppy; while others use the term 
 
MODE III. LIMESTONE. 457 
 
 oolite, from the eggs or roe of fish : but as this ap- 
 pellation might imply that the grains equal the 
 eggs of birds, it is ambiguous ; not to add that, 
 as the substance was really supposed to be the 
 petrified roes of fish, whence the English roe- 
 stone, it is better to dismiss a term leading to erro- 
 neous ideas. The analogy between pisolite and 
 sinapite is also preferable, both being derived from 
 the vegetable kingdom. 
 
 This substance is far more abundant than piso- 
 lite. According to Gmelin, it is frequent in the 
 stratified mountains of Gothland, Saxony, Thu- 
 ringia, Brunswick, France, Swisserland; forming 
 ample and often repeated strata, of a dull grey or 
 brown colour ; and sometimes, though rarely, pre- 
 senting animal remains. 
 
 The Ketton stone of Rutlandshire is a fine ex- 
 ample of this kind of rock. 
 
 Sinapite, from Iceland. 
 
 The same, from Ketton. 
 
 The same, of a still finer grain, from Bath. 
 
 The same, from the various countries mentioned 
 by Gmelin, where, as it forms vast beds, it cannot 
 be classed among the depositions. 
 
 

 458 DOMAIN V. CALCAREOUS. 
 
 MODE IV. ALABASTRITE. 
 
 Ancient. The substances called alabastrum and ala- 
 bastrites by the ancients, are well known to be 
 merely calcareous, as they effervesce with ni- 
 trous acid ; whereas the moderns have applied 
 the name of alabaster to quite a distinct sub- 
 stance, impregnated with the sulphuric acid, so 
 that the nitrous can produce no effect. 
 
 The classical writers of antiquity more fre- 
 quently use the word alabastrites than ala- 
 bastrum; and it seems therefore far more proper 
 to retain the former name for the ancient ala- 
 baster, than to apply it with some writers to the 
 modern. In general it is distinguished by its 
 yellow colour, especially mentioned by Pliny; 
 and often by brown stripes, arising from suc- 
 cessive depositions, with some resemblance of 
 the layers of the onyx, whence the onyx tables 
 and pavements of the ancients. For alabastrite 
 is acknowledged to be a mere deposition front 
 superincumbent rocks of marble ; and, with sta- 
 lactite and stalagmite, forms the sinter of the 
 Germans; while alabaster is an original rock, 
 and is even found primitive in the Alps. 
 
 Of^this remarkable substance, so well known 
 
MODE IV. ALABASTRITE. 
 
 in Roman luxury, Pliny gives the following ac- 
 count. " Our ancestors thought that onyx was 
 only produced in the mountains of Arabia, and 
 in no other region; but Sudines adds Carmania*. 
 At first only drinking vessels were made of it ; 
 but afterwards the feet of beds, and even seats. 
 Cornelius Nepos says that it was reputed a great 
 wonder when P. Lentulus Spinter displayed am- 
 phorae of onyx as large as Chian casks; yet five 
 years after he saw columns thirty* two feet in 
 length. But from more refinement in the choice 
 of this stone, four columns of a middling size, 
 placed by Cornelius Balbus in his theatre, were 
 esteemed monuments of surprising grandeur. 
 We have seen more than thirty in the dining- 
 hall which Callistus, well known by his power 
 among the freemen of the emperor Claudius, 
 had erected at great expense, 
 
 K" Some have called this stone alabastrite ; and 
 f it little pots or boxes for ointments are formed, 
 as in them it is supposed to be less liable to cor- 
 rupt f. When calcined it is also used for plas- 
 
 * So Brotier's edition : some read Germany. 
 f Hence the name, which implies what cannot be taken hold 
 of; because, as commonly supposed, these little pots had no han- 
 dles. But may it not imply the slippery smoothness of the pot or 
 of the stone ? 
 
 Nardi parvus onyx. HOR. 
 
460 
 
 DOMAIN V. CALCAREOUS. 
 
 ter. It is produced towards Thebes in Egypt, 
 and near Damascus in Syria; but this last is 
 white, and little esteemed. The best is from 
 Carmania, the next from India, and a valuable 
 sort is also found in Syria and Asia Minor. 
 The worst, and without any splendour, is that 
 of Cappadocia. They are chiefly approved 
 when of a honey yellow, with orbicular clouds, 
 and little translucent. It is esteemed of little 
 value when of a horn colour, or white, or of a 
 glassy appearance."* 
 
 Pliny then mentions that the Lygdine marble 
 
 Alalastrum seems to have been more generally used in later 
 times : cum alabastris unguenti, says the author of the work ascribed 
 to Petronius Arbiter ; and who has deceived all the critics, for he 
 surely flourished about the time of Elagabalus ; and his keen satire 
 is directed against the manners, and not Nero, or any particular 
 person. The learned reader may consider the list of presents, 
 p. 211, edit. 1669, and may compare many other passages with the. 
 Historic? August Scriptores, which form the best introduction to 
 this strange work. See also the arguments in the preface of Ha- 
 drianides, or Hadrian de Valois, which indicates a verse taken from 
 Statius, and refers this satire to the age of Gallienus. The castella 
 for villas, used by this author, is first introduced in that sense by 
 Apuleius. 
 
 Alalastrum is also put absolutely, by other writers, for a lox of 
 alalaster, commonly used to contain ointment. That poured on 
 the feet of Jesus was in " a box of alabaster." John xii. 3, and 
 other evangelists. It was a sacrifice of her toilette by Mary Mag- 
 dalen. 
 
 * xxxvi. 12. 
 

 
 MODE JV. ALABASTKITE. 4l6l 
 
 of Paros was next in esteem for preserving oint- 
 ments ; and it is probable that this name did not 
 extend, as is supposed, to the marble of Paros in 
 general, but was confined to stalactitic portions 
 found in certain cavities. Though this sub- 
 stance be merely an infiltration from surround- 
 ing rocks, yet it sometimes fills immense caverns, 
 so that tables may be seen in Italy, and some 
 even in England, of eight feet by four; being 
 entire slabs of the most beautifully veined ala- 
 bastrite, commonly called by the artists oriental 
 alabaster. The veins seem to be chiefly of a 
 ferruginous nature. When iron is absent the 
 substance may remain of the purest white; as 
 the grand and singular depositions in the well- 
 known grotto of Anti-Paros, one of the wonders 
 of the world. But this pure white kind, being 
 of a very soft and fragile nature, was. little 
 esteemed by the solid taste of the ancients; and 
 is seldom used even by modern artists, except 
 in minute and trifling ornaments. The yellow 
 and vekied kinds, on the contrary, are hardened 
 by the presence of iron, so as to scratch marble, 
 which may also be done by portions of the 
 white, as the softness rather arises from the lax- 
 ity of the grain, probably from the want of com- 
 pression. 
 
 In modem times alabastrite, equal to the an- 
 
'^ DOMAIN V. CALCAREOUS. 
 
 cient, with brown veins, has been found in smalt 
 pieces at Mont Martre, near Paris; but those of 
 Spain are in rocky masses, and of great beauty. 
 It is said that the territory of Volterra, in Tus- 
 cany, affords no less than twenty remarkable 
 varieties*. 
 
 r Voiterra. Those most esteemed are the agate-alabas- 
 ters, to which this name is given, on account of 
 their fineness; and the onyx-alabasters, which 
 present clear and distinct layers, of different co- 
 lours, all of them undulated and festooned, with 
 saliant and re-entering angles, like the zones 
 of fortification-agates, and of which the whole 
 forms a figure nearly circular. The formation 
 of these zones is owing to a play of crystal- 
 lisation, like that of agates ; and in like manner 
 they are always found exactly parallel among 
 themselves, whatever may be the irregularity 
 of their course. A perpetual circulation takes 
 place in the interior of the alabaster, while it is 
 still in its native site, which arranges the various 
 particles of which it is composed, according to 
 laws determined by their mutual affinities. 
 
 " The onyx-alabaster is sometimes formed in 
 sheets on a horizontal plane; and then these 
 
 * Patrin, iii. 110. In the catalogue of Davila, ii. 98, it ii 
 observed that the ancient alabasters were probably from Spain, a 
 the same sorts abound there. 
 
v MODE iy. ALABASTRITE. 4(53 
 
 layers, instead of forming re-entering courses, 
 describe straight lines, or slightly undulated ; 
 and as these layers are of lively marked colours, 
 such as the white and Ted, cameos may be made 
 of them, as they are of onyx-agates. 
 
 " The onyx- alabaster of Sienna is of the ut- 
 most beauty : it presents layers of three bright 
 and distinct colours; yellow, red, which is opake, 
 and white, which is very transparent. 
 
 " The other alabasters of Italy, which are 
 most valuable, are the agate-alabaster of Sienna, 
 which is nearly transparent, and of a fine uni- 
 form yellow. 
 
 " The alabaster of Montanto, in Tuscany, 
 which is yellow, semi-transparent, with undu- 
 lated white veins. 
 
 " The alabaster called Pecorino, which is 
 transparent, of a uniform fawn colour, or min- 
 gled with brown veins. 
 
 " The isle of Malta also furnishes various ala- 
 basters, and particularly one of the colour of 
 wax, like the agate- alabaster of Sienna ; its paste 
 is of the greatest fineness, and of a beautiful 
 semi-transparency. In the Museum of Arts is 
 seen a statue of Minerva, nearly as large as life, 
 of a similar alabaster, which is much admired. 
 
 " The name of oriental alabaster is given to 
 that which adds to a fine paste lively and distinct 
 
464 DOMAIN V. CALCAREOUS. 
 
 colours, and a hardness which renders it suscep- 
 tible of a fine polish. In general, the denomi- 
 nation of oriental stone implies less the native 
 place of the stone, than its intrinsic value ; thus 
 
 tin Italy and France alabasters are found which 
 * 
 deserve the epithet of oriental. 
 
 " The celebrated sculptor Puget discovered 
 near Marseilles an alabaster, so transparent, that 
 the eye could penetrate into the interior of the 
 substance; and, to the depth of two fingers, 
 trace the beautiful tints with which it was co- 
 loured. 
 
 " Guettard says that the waters of Aix, in 
 Provence, form a deep-brown alabaster, mingled 
 with whitish zones, which make it resemble 
 the oriental kind. This alabaster is found in 
 an ancient conduit, built by the Romans, which 
 brings the water from a spring about half a 
 league from the town. 
 
 " This aqueduct was entirely filled by this 
 beautiful alabaster, which presented distinct 
 layers, of about a line in thickness. They were 
 found by the lens to be composed of a great 
 number of very thin plates; and the whole 
 formed a solid compact mass, hard enough to 
 take the finest polish. 
 
 " At Montmartre, and in the other hills of 
 plaster-stone in the environs of Paris, and espe- 
 
MODE IV. ALABASTRITE. 
 
 cially at Lagny, a substance is found, which at 
 first view resembles a fine oriental alabaster: 
 brown zones of different tints, on a lighter base, 
 are in like manner observed in it ; they are un- 
 dulated, and parallel to one another, and pro- 
 duce a most pleasing effect. But this pretty 
 stone is only a stalactitic gypsum, which takes 
 but a slight polish, and much less brilliant than 
 that of real calcareous alabaster*." 
 
 Yellow clouded alabastrite, from the ruins of 
 Rome. 
 
 Veined alabastrite, the onyx of the ancients, 
 from the same. 
 
 A noble column, about twenty-four feet in 
 height, was found near the Appian way, and 
 placed in the library of the Vatican; perhaps 
 the same which is now in the Museum at Paris. 
 
 Veined alabastrite, white, with reddish yellow 
 veins, from Andalusia, Spain. 
 
 Veined alabastrite, from different parts of 
 Spain. 
 
 With mazy veins, light yellow and brown, 
 from Malaga. This has furnished many deco- 
 rations for the palace at Madrid. 
 
 Mazy alabastrite, of a deep brown, with lighter 
 veins, from Sagena, in Sicily, 
 
 * Patrin, ib. 
 VOL. I. 2 H 
 
466 'DOMAIN v. CALCAREOUS. 
 
 With veins of a lively red, mingled with yel- 
 low ones more or less deep, from Montreal, in 
 Sicily. 
 
 With yellow and black veins, from Mount 
 Pellegrino, in the same country. 
 
 Yellow, veined with white; and another, with 
 black, brown, and white mazes, from Malta. 
 
 There is also a kind of alabastrite which the 
 Fiorito. Italians call fiorito, implying that it is marked 
 with irregular spots, faintly resembling flowers. 
 Two columns of this kind, very rich in colours, 
 which however he does not specify, are placed, 
 according to Brard, in the Napoleon Museum 
 at Paris. They were discovered, in 1780, in 
 the ruins of Gabium, four leagues from Rome. 
 It is probably with this kind of alabastrite that 
 Strabo compares the Synnadic marble, when he 
 says it is variegated like alabastrite ; but perhaps 
 he means its light aerial appearance, whence 
 fche poet of St. Sophia compares it to roses sprin- 
 kled on white air. 
 
 For the common or modern alabaster, the 
 reader is referred to Mode X,, which follows 
 Gypsum. 
 
MODE V. LIME-SLATE. 
 
 MODE V. LIME-SLATE. 
 
 The marbles, konites, limestones, and alabas- Distinction, 
 trites, are so important in many points of view, 
 that though this kind chiefly differ in the struc- 
 ture from limestone, it was thought advisable to 
 give it a distinct division, especially as the mode 
 of combination is really different, for, not to men- 
 tion the micaceous kind, it is more abundant irj 
 argil than the massive limestone. Lime-slate is 
 the calcareusfissilis of Wallerius; but the foliated 
 limestone of Werner is so called only from the 
 fracture. 
 
 Lime-slate sometimes presents alternate layers 
 of different colours; such as white and reddish, 
 and white and greenish; both of which are 
 found at Dannemora, in Sweden. It sometimes 
 alternates with keralite or chert, sometimes with 
 clay-slate, sometimes with marl-slate. Some 
 singular marbles, of which the veins are quite 
 detached, a,nd uniform, probably belong to this 
 division. The cipolin also sometimes, though 
 rarely, appears in level layers, divided by foli- 
 aceous mica*. 
 
 * The whole isle of Garbolach, Hebudes, is said to be composed 
 f lime-slate, or what is called marllejlag. 
 
 2 H 2 
 
468 DOMAIN V. CALCAREOUS. 
 
 Saussure observed many mountains in the 
 Alps chiefly composed of what he calls mica- 
 ceous limestone, often alternating with mica 
 slate. The following observations occur in his 
 description of Mont Cenis, celebrated for the 
 passage into Italy. 
 
 " Soon after is observed the micaceous schis- 
 tu>s, which really forms the body of the moun- 
 tain, but which is also found in some places 
 covered with tufas. These schisti contain cal- 
 careous earth, with a granular and brilliant 
 aspect, such as it assumes in primitive moun- 
 tains: it is even in such quantity that these 
 schisti strongly effervesce with the nitrous acid; 
 and become friable, after having remained some 
 time in it. 
 
 " It will be seen hereafter that calcareous earth 
 and mica are found at Mont Cenis, mingled in 
 all proportions ; from limestones nearly pure, in 
 which only a few plates of mica are observable, 
 to the micaceous rock, which contains little or 
 no free 'calcareous earth, and in which quartz 
 supplies the place occupied by the limestone in 
 the former. There is nevertheless this remark- 
 able circumstance in the schisti of Mont Cenis, 
 that those which are calcareous are seldom found 
 free from quartz, as is proved by the sparks that 
 may be almost always obtained from it by steel $ 
 
Mt>DE V. LIME- SLATE. 
 
 and in like manner quartzose micaceous schistus 
 is seldom found which does not 4 yield some bub- 
 bles in acids, and which, reduced to powder, 
 does not lose some of its weight in distilled 
 vinegar. 
 
 " These micaceous calcareous schisti are not 
 common. Those authors who have written sys- 
 tems of mineralogy have not known them, or at 
 least have neither classed them, nor given them 
 names in their works. I have described, in the 
 second volume of these travels, 996, those 
 which I discovered in the valley of Aosta in 
 1778; but in them the free calcareous part is 
 never predominant, it forms at most but the 
 fourth part of the rock. Those of Mont Cenis 
 differ also in the colour of the mica, which is of 
 an iron grey, or verging to blue, while that of 
 the valley of Aosta is white or yellowish. 
 
 "The first rocks of this kind, which are met 
 with above Lans-le-Bourg, have very thin and 
 very fragile plates: they rise to the E. S.E., un- 
 der an angle of twenty degrees; higher, after 
 having crossed a little bridge, the same schisti 
 are found in an opposite position, or rising to 
 the west. But this position is accidental ; it 
 may be said that in general they rise to the 
 E. S,E,, following the slope of the mountain."* 
 
 * Sauss. J234. 
 
470 DOMAIN V. CALCAREOUS. 
 
 other sites. This micaceous lime-slate was afterwards ob- 
 served by our Excellent author at the little St. 
 Bernard ; and at the Roth-Horn and Mont Cer- 
 vin, two mountains near the celebrated Rosa, 
 chiefly composed of serpentine. 
 
 The subsequent detached observations lilay 
 also be added from the same treasure of oro- 
 logical knowledge. 
 
 Near Morges the mountains are all calcareous* 
 with undulated veins mixed with mica, forming 
 a firie cipolino. The roofs of the houses are co- 
 vered with thin plates of the same stone. 
 
 A bed of primitive lime-slate, between beds of 
 gneiss. It is six feet in thickness; and the 
 layers, of about half an inch, are tinged by 
 some infiltrated green matter. 
 
 A lime-slate, analysed, which is incumbent on 
 granite. 
 
 Roche Michel, near Mont Cenis, is composed 
 of a mixture of calcareous mica slate and green- 
 ish talc, the latter being predominant*. 
 
 Aspect 1. Micaceous lime-slate . From Mont 
 Cenis. From M. Cervin, and other parts of the 
 Alps. 
 
 The same, from Canada, North America. 
 
 A micaceous lime-slate, the limestone being 
 
 * Sauss. Q50, 2225, 8?2, 1262. 
 
MODE V. LIME-SLATE. 471 
 
 granular and brilliant, as it appears in primitive 
 mountains. Sauss. 1234. 
 
 Aspect 2. Common lime-slate. From Gib- 
 raltar. 
 
 In layers of different colours, from Sweden. 
 
 With chert, from Derbyshire. 
 
 A fine lime-slate, of a bluish grey, the leaves 
 being very thin and inseparable. Sauss. 2047. 
 
 A lime-slate, with quartz and mica, near Ville 
 Neuve, on the river Doire. Ib. 955. 
 
 Dr. Kidd has given the following interesting 
 account of a quarry of this kind of stone, if he has 
 not mistaken calcareous sandstone for limestone, 
 a mistake which riot unfrequently occurs. He 
 calls the substance calcareous slate, or flag-stone ; 
 while the latter name is commonly applied to a 
 schistose sandstone, either calcareous or argil- 
 laceous. The limestone of Pappenheim, in Ger- 
 many, rises from the quarry in thick tables, serving 
 at once for pavements, gravestones, or similar 
 purposes, and certainly belongs to this kind, as 
 must the following, if Dr. Kidd's description be 
 exact. 
 
 " There is a very extensive quarry at Stones- Quarry of 
 
 J Stonesfield. 
 
 field, near Woodstock, the limestone of which has 
 the property of being easily separated into la- 
 minae by mechanical means, or even by the action 
 
472 DOMAIN V. CALCAREOUS. 
 
 of the atmosphere. The manner in which the 
 effect is produced in the latter instance may be 
 understood by a reference to what was said re- 
 specting that superficial disintegration which takes 
 place occasionally in calcareous free-stone. 
 
 " This variety of limestone is employed very 
 generally for the purpose of covering the roofs of 
 houses ; whence it has been called lapis tegularis. 
 The property of being thus easily separated into 
 laminae depends partly upon the proportion of 
 clay contained in it (for this property is in general 
 more remarkable in proportion to the quantity of 
 clay contained), and partly upon the nature of its 
 original deposition; for the stone of some parts of 
 the quarry contains a considerable quantity of 
 minute shells, resembling millet seeds; and it 
 seems worth observation, as connected with the 
 schistose property of the stone, that the depo- 
 sition of shells is more abundant on the surface 
 than in the substance of the laminae. 
 
 " In some instances a singular arborescent ap- 
 pearance is observable on the contiguous surfaces 
 of adjoining laminae : the colour of this is for the 
 most part black; and, from some experiments 
 that were made for the purpose of ascertaining its 
 nature, appeared to be principally manganese. 
 The same appearance is observable in some varie- 
 ties of Florentine marble. Sometimes the colour 
 
MODE VI. CORAL ROCK. 4/3 
 
 is only superficial ; at others it penetrates far into 
 the substance of the stone. The explanation of 
 the appearance is not obvious; but perhaps some 
 liquid, holding the colouring matter in solution, 
 originally insinuated itself into the clefts by which 
 the laminae are separated from each other, and 
 deposited this, particle by particle ; by something 
 like that continuous attraction, if the term is 
 allowable, which takes place in the freezing of 
 moisture on a pane of glass." * 
 
 MODE VI. CORAL ROCK. 
 
 The texture resembles clustered corals, or 
 madrepores, cemented by limestone j-. 
 
 This substance has not yet been mentioned in Origin, 
 books of mineralogy, though large islands and 
 vast shoals in the South Sea, particularly on the 
 east of Australasia, are wholly composed of it, 
 according to the accounts of navigators. Coral 
 
 * Vol. i. p. 31. See also Da Costa, p. 144, who adds, that a 
 similar slate is found near Bath. The white flag common in the 
 north of England he ranks among the alkaline calcareous sand- 
 stones : it is spangled with mica, sometimes very prettily, especially 
 that with little needles, lying in a diagonal form. 
 
 f The characters of limestone apply to many of the rocks in this 
 domain, and are therefore not repeated. The characters are als 
 Sometimes implicated in the descriptions. 
 
474 DOMAIN V. CALCAREOUS. 
 
 itself is now known to be the gradual structure of 
 minute insects, which thus surpass all the powers 
 of man ; for the locust can spread more destruc* 
 tion than an Attila, a Timur, or any other 
 conqueror : and a beneficent monarch can only 
 found a city; while insects almost invisible found 
 islands, and even continents, the scenes of future 
 glory and misery to mankind. 
 
 Whether these insects produce the matter of 
 coral, or imbibe it from the waters of the ocean, 
 these islands rise from a surprising depth, and, 
 when they surpass the waves, begin to produce 
 lichens and mosses; which, decaying and rot- 
 ting, afford a soil for other small vegetables, till 
 by degrees reeds, shrubs, and trees, begin to 
 decorate the new creation. The calcareous soil 
 being fertile, these islands will in the course of 
 centuries invite colonies, whose future mineral- 
 ogists may perhaps be embarrassed to account 
 for their native rocks; which may at once con- 
 fer benefits on agriculture and on architecture, 
 for zoophytic marble will not be wanting for 
 the construction of their edifices. 
 
 Rocks of a somewhat similar nature abound 
 near Sutherland, on the eastern coast of England; 
 and near Peterhoff, at the further extremity of 
 the Gulf of Finland. This singular limestone 
 seems composed of tubes of madrepore or coral, 
 
MODE VII. MARLIT*. 475 
 
 often with open intervals; and at Sutherland is 
 the common building-stone. 
 
 Coral rock, from Australasia. 
 
 Madrepore rock, from Sutherland and Pe- 
 terhoff. 
 
 MODE VII. MARLITE. 
 
 The combination of this substance is the same Description, 
 with that of marl, the calcareous earth being 
 mixed with a considerable proportion of argil. 
 Some marbles, which contain from 15, to 30 or 
 more of argil, are properly marlites $ and they 
 are apt to decompose in the open air. Such is 
 the green Campan of the Pyrenees, which also 
 contains a considerable proportion of magnesia. 
 Several of the Russian marbles also contain clay, 
 but mixed with a still larger proportion of silex. 
 
 The celebrated pictorial marble of Florence, 
 which imitates ruins, and sometimes trees, is 
 properly a marlite. 
 
 " This marble presents angular figures of a Marble of 
 yellowish brown, on a base of a lighter tint, and 
 which passes, in diminishing, to a whitish grey. 
 
 " Seen at a certain distance, slabs of this 
 stone resemble drawings done in bistre. One is 
 amused to observe in it kinds of ruins : there, it 
 
476 DOMAIN V. CALCAREOUS, 
 
 is a Gothic castle half destroyed, here it presents 
 ruined walls ; in another place old bastions ; and 
 what still adds to the delusion is, that in these 
 sorts of natural paintings there exists a kind of 
 aerial perspective, which is very sensibly per- 
 ceived. The lower part, or what forms the first 
 plane, has a warm and bold tone ; the second 
 follows it, and weakens as it increases its dis- 
 tance ; the third becomes still fainter, while the 
 upper part, agreeing with the first, presents in 
 the distance a whitish zone, which terminates 
 the horizon, then blends itself more and more as 
 it rises, and at length reaches the top, where it 
 sometimes forms as it were clouds. 
 
 " But approach close to it, all vanishes im- 
 mediately, and those pretended figures, which 
 at a distance seemed so well drawn, are converted 
 into irregular spots, which present nothing to 
 the eye. 
 
 " This play of nature is owing to ferruginous 
 infiltrations in the fissures of this marble, which 
 otherwise is of a dull fracture, and very argil- 
 laceous; whence it is never used in architecture; 
 they merely make slabs of it, which are framed 
 like little pictures, and which are much esteemed 
 in commerce when of certain dimensions. It 
 sometimes occurs that the same slab is sawed in 
 two, and the parts are set together in the same 
 
MODE VII. MARLITE. 
 
 477 
 
 frame, so as to appear but as one piece; and the 
 drawings on the right and left bear a resem- 
 blance, which still farther helps the illusion. 
 There are some, who, to out-do nature, put 
 painted figures at the bottom of these pictures; 
 but this is an exuberance of the wonderful, 
 which finishes by spoiling all."* 
 
 Of marlite there are two structures, the mass- 
 ive and the schistose. 
 
 STRUCTURE I. MASSIVE. 
 
 Aspect 1. Argillaceous marble. Green and 
 red of Campan ; but which, from their structure, 
 rather belong, at least in part, to the Anomalous 
 Rocks. 
 
 The reddish of Ingermania, c. 
 
 Aspect 2. Pictorial marble. This is said to 
 be massive, though it would rather appear to be 
 schistose. The marble of Cottam probably be- 
 longs to this division. 
 
 * Brard,415. The marble of Oker in the Hartz is white, with 
 regular veins -of black clay slate; and may be classed in this divi- 
 sion. Jour, des Mines, No. 23, p. 73. 
 
 The marlite of Shropshire, called dye-earth, more than 100 
 yards thick, contains small bivalves, and what are called the Dud- 
 ley fossils, the entomolithus paradoxus of Townson. See his Tracts, 
 p. 16$, 177- 
 
478 DOMAIN V. CALCAREOUS. 
 
 STRUCTURE II. SCHISTOSE. 
 
 Substances in this state generally present a 
 finer grain than when they occur massive. Marl- 
 slate sometimes presents delicate concentric cir- 
 cles, and other delineations, of a light brown upon 
 yellowish grey, its usual colours. 
 
 Im of fish. " 8 But ft * s st *^ more remarkable, as being the ge- 
 neral repository in which are found the remains 
 and impressions of decayed fish. In this case it 
 is commonly penetrated with bitumen, probably 
 derived from the decomposition of their bodies, as 
 chemists now infer that substance to proceed ex- 
 clusively from the animal or vegetable kingdoms, 
 Da Costa mentions that of Mount Lebanon, near 
 Tripoli di Soria (of Syria), in the province of 
 Castravan*. 
 
 The slate, with impressions of fish, from Eisle- 
 ben, Ilmenau, Mansfeld, &c. were formerly ce- 
 lebrated, and the animals are often delicately 
 delineated, as it were, in cupreous pyrites. At 
 present those of Mount Bolca, in the Veronese 
 territory, have attracted more attention ; and the 
 proprietor has filled a whole chamber in the mu- 
 seum of the Garden of Plants with these singular 
 
 * P. 170. This is the Khesroanof D'Anville, and the Castracaa 
 of the Italians, whence the celebrated iumachella. 
 
MODE VII. MARLITE. 479 
 
 remains. The mud and poisonous vapour, per- 
 haps of a volcanic origin, seem to have surprised 
 and destroyed these animals almost instantane- 
 ously, for most appear to struggle, and one is in 
 the act of swallowing another. 
 
 Saussure has described similar quarries near 
 Aix, towards Lambesc, in the south of France, 
 which also present impressions of leaves of palm- 
 trees. The same great observer has added an 
 account of that of Oeningen, near the lake of 
 Constance, which first presents a thin layer of soft 
 micaceous sandstone, cemented by clay and lime ; 
 another of coarse marl and marl-slate, followed 
 by lime-slate, alternating with layers of clay. At 
 the depth of nine or ten feet appears the rock, 
 which contains the impressions ; and which is, as 
 usual, a bituminous marlite. The fish are accom- 
 panied with several insects, and leaves of trees, 
 some of which belong to warmer climates; but 
 far from being so extraordinary as those of Mount 
 Bolca, which, not to mention more recent dis- 
 co veries, presented at the time when Sajussure 
 wrote, 1795, 
 
 27 kinds of fish of the European seas. 
 
 39 ... of the Asiatic. 
 3 ... of the African. 
 18 ... of South America. 
 
480 DOMAIN V. CALCAREOUS. 
 
 1 1 kinds of fish of North America. 
 7 ... of fresh water of the differ- 
 ent parts of the world. 
 In all 105. 
 
 MODE VIII. ORSTEN. 
 
 Name, Some of the Swedish appellations ought to be 
 
 Swedish. 
 
 venerated, as that country has produced such 
 able writers in natural history, and particularly 
 in mineralogy; of which science Wallerius, 
 Cronstedt, and Bergman, must be esteemed as 
 the chief founders. The substance now under 
 view has by some of our mineralogists been 
 called swinesLone> and by the Germans and 
 French less politely stinkstein y andpierrepuajite; 
 but as the Swedish name has more brevity, and 
 does not impress a disagreeable idea, it deserves 
 to be substituted. 
 
 Description. Orsten is merely a limestone, which, some- 
 times from a mixture of bitumen, sometimes 
 from yet unknown causes, yields a fetid smell, 
 when worked in the quarry, or in the marble 
 yards, or even when rubbed with any hard sub- 
 stance. In a geological point of view, it has 
 assumed higher consequence, since it was dis- 
 
 
MODE VIII. ORSTEST* 4S 1 
 
 covered by Ramond to form the summit of Mont 
 Perdu, the highest of the Pyrenees. It is gene- 
 rally of a black colour; but some specimens 
 from Derbyshire are even white, or at least 
 whitish grey. The other tints are chiefly va- 
 rious greys, with brown and Isabella yellow. 
 
 Mr. Kirwan says that the smell is urinous or 
 alliacious; and that it abounds in the county of 
 Gal way, in Ireland, where, as fuel is scarce, it is 
 often employed to heat the rooms, and remains 
 hot for many hours. In the neighbourhood of 
 Vesuvius it is found laminar, alternately white 
 and yellow. It often produces excellent lime. 
 
 A grey Flemish marble, now much used at 
 Paris, belongs to this kind, and leaves a very 
 fetid smell in the manufactories. That of the 
 summit of Mont Perdu is a black marble, im- 
 pregnated with shells and sand. Ammonites 
 and camerines, gryphites, pectenites, with mad- 
 repores, and other zoophytic remains, enter into 
 the composition of the singular calcareous chain 
 of the Pyrenees. 
 
 Black orsten, from the summit of Mont Perdu. 
 
 Grey, with zoophytic remains, from Flanders. 
 
 In yellow and white plates, from Vesuvius. 
 
 Greyish white, from Derbyshire. 
 
 VOL. I. 
 
482 DOMAIN V. CALCAREOUS. 
 
 MODE IX. GYPSUM. 
 
 Characters. Texture, coarse-grained and loose, commonly 
 with a saline or crystalline appearance. 
 
 Hardness, of course gypsic. Fracture, un- 
 even. Fragments, amorphous, blunt. 
 
 Weight, granitose, sometimes only carbonose. 
 
 Lustre, glimmering. Opake. 
 
 The colour of that of Montmartre is a yellow- 
 ish brown ; but it is also found of various tints 
 of grey : and is sometimes so compact as to 
 resemble coarse limestone. 
 
 As gypsum and alabaster consist of the same 
 peculiar ingredients, though they vary in the 
 mode of combination, it may be proper to begin 
 by considering them on a large scale, and in 
 one point of view. 
 
 In the language of modern chemistry, gypsum 
 and alabaster are sulphates of lime; the sul- 
 phuric acid forming about half of their compo- 
 sition, as the carbonic does in the other cal- 
 careous rocks: hence the gypsous substances 
 do not effervesce with nitrous acid, like the va- 
 rious descriptions of limestone*. 
 
 * Fluor very rarely forms rocks ; but with Phosphorite may be 
 found in the Anomalous division. 
 
MODE IX. GYPSUJVf. 483 
 
 The distinction between gypsum and alabas- 
 ter may be regarded as more wide than that be- 
 tween limestone and marble, though chemical 
 writers arrange alabaster as merely a compact 
 gypsum ; but the artist, and the antiquary, and 
 even the common observer, consider alabaster as 
 a distinct substance. 
 
 As limestone may be called a coarse marble, 
 and when calcined forms lime, so gypsum may 
 be regarded as a coarse alabaster, which when 
 calcined forms what is called plaster of Paris, 
 because the best is made of the gypsum of 
 Montmartre, in the neighbourhood of that city; 
 and the alabaster of the moderns, or compact 
 sulphate of lime, has, like marble, been em- 
 ployed by the sculptor and the architect, being 
 of a fine grain, and of a whiteness which has 
 become proverbial. The tombs of the middle 
 ages are sometimes of alabaster, yet more gene- 
 rally, it is believed, of alabastrite; but this has 
 seldom been examined; for while every parish 
 has its antiquaries, we have few mineralogists. 
 
 Some kinds of gypsum and alabaster, as the 
 earthy and fibrous, with the crystallised, called 
 selenite or moon-stone, as it somewhat resembles 
 the gleam of the moon in water, are founcf in 
 veins and nodules, and belong to lithology. In 
 literary composition, as in painting, the eye 
 
484 DOMAIN V. CALCAREOUS. 
 
 should repose on large masses or divisions ; while 
 minute and broken lights only distract the at- 
 tention and the memory. The gypsous rocks 
 may safely be reduced to two kinds, the coarse 
 and the compact. 
 
 Primitive. It was long conceived that gypsum was of 
 the most recent formation, till a rock of this 
 kind, undoubtedly primitive, was discovered by 
 Saussure in the Alps. Dolomieu indeed ex- 
 presses his wonder, that gypsum has not been 
 more frequently formed from primitive marble, 
 as the sulphuric acid might easily be produced 
 from the decomposition of pyrites. But the re- 
 marks of Saussure must not be omitted. 
 
 " In regard to gypsum, it is found at St. 
 Gothard, either below Ayrol, as I have said, 
 1805, or in the Val-Canaria. It is in mass, of 
 a fine and brilliant grain; it does not effervesce 
 with acids, and consequently is free from all 
 calcareous mixture. 
 
 " But what is more rare, is to find gypsum 
 in a schistose form, and mixed with thin layers 
 of mica: this contains some calcareous parts j 
 it slightly effervesces. 
 
 " I do not think that this gypsous schistus is 
 a primitive rock, like the calcareous micaceous- 
 schistus ; I believe it to be of modern origin, 
 and that it originated by deposition in hollows, 
 
MODE IX. GYPSUM. 485 
 
 aince the formation of the secondary mountains. 
 The specimens which I possess are of a nature 
 to justify this idea; their texture is not homo- 
 genous ; the mica does not appear to have been 
 united to the gypsum by a simultaneous crystal- 
 lisation : it is in plates nearly incoherent, which 
 separate thin layers of an argillaceous sediment. 
 This mica then seems to have been brought 
 down and deposited by the waters, rather than 
 crystallised in them. Nevertheless, as I have 
 not observed it in its native site, I dare not be 
 too decided in this opinion." * 
 
 This gypsum was observed by Saussure in 
 passing from Bellinzona to St. Gothard ; but we 
 are told by Brochant and Jameson that the pri- 
 mitive gypsum was discovered near Bellinzona; 
 and they add, that it is in layers between beds of 
 mica slate ; and Jameson says, along with lime- 
 stone and hornblende slate. I know not their 
 authority for this assertion; but the objections 
 of Saussure seemed to Patrin so powerful, that 
 he virtually denies the existence of primitive 
 gypsum, by asserting that it is wholly tertiary. 
 The mixture indeed of mica is of little conse- 
 quence, as it is found in the most recent sand- 
 Atones ; and even that of felspar, as observed by 
 
 * 1931. 
 
486 DOMAIN V. CALCAREOUS. 
 
 Pallas in Siberia, would not now be regarded as 
 of much importance. The pretended porphy- 
 ries of Werner should, as already mentioned, be 
 simply referred to their bases ; for felspar, like 
 mica, being found in every description of rock, 
 <jan no longer be understood to alter the deno- 
 mination. 
 
 This gypsum, supposed primitive, has a schis- 
 tose structure, and approaches to selenite in 
 purity. A pure selenite, dividing at right an- 
 gles, was discovered by Gillet-Laumont, on the 
 left bank of the Doron, above Moutiers, Mont 
 Blanc ; and in the same neighbourhood a fine 
 alabaster, and a red gypsum. This beautiful 
 snow-white alabaster easily splits in cubes, and 
 is of a peculiar texture ; it sometimes presents 
 acicular crystals of selenite, with brown spots, 
 which this excellent mineralogist suspects to be 
 ferriferous carbonate of lime*; but he did not 
 express his idea that it was of primitive forma- 
 tion. 
 
 Gcognostic But these are minute exceptions ; and in ge- 
 neral gypsum and alabaster must be classed 
 among the Floetz, the planiform, or horizontal 
 rocks of Werner. Sulphate of lime is commonly 
 
 * % Chaux carlonatee jaune y fcrrifere, as marked in the catalogue 
 which he gave me of several rock specimens. The precise site i 
 Salins, near Moutiers, Mont Blanc. 
 
MODE IX. GYPSUM. 437 
 
 a simple rock, like limestone, and sometimes 
 occurs in large masses and beds ; but sometimes 
 in layers, alternating with orsten, clay, or sand- 
 stone. It sometimes contains crystals of quartz, 
 and in rare instances arragonite and boracite. 
 It also sometimes presents native sulphur; and 
 often appears in the neighbourhood of rock salt. 
 It seldom attains a great height, but forms little 
 precipices, which, when of the purer kind, are 
 distinguished by their white lustre. Hollows, 
 like funnels, are sometimes formed in gypsum, 
 which Saussure, 1238, ascribes to the rain water, 
 which, attacking a soft part, remains, and, gra- 
 dually increasing, melts the surrounding circle. 
 
 Gypsum is generally of a whitish yellow, or 
 yellowish brown cast; but it also occurs of an 
 ash grey colour, in which case, as Saussure has 
 observed, it can only be distinguished from lime- 
 stone by the nitrous acid producing no effect. 
 
 One of the most remarkable gypsous hills in Montmartre. 
 Europe is that of Montmartre, near Paris, not 
 only from its producing the plaster best known 
 in commerce, but from its peculiar constructure, 
 and the singular animal remains which have 
 there been discovered. It is thus described by 
 the venerable M. Sage, whose chemical mistakes 
 may be forgiven, in the consideration of the 
 great services he has rendered to mineralogy, 
 
4SS DOMAIN V. CALCAREOUS. 
 
 particularly by the formation of a noble cabinet, 
 now the public property. The respect due to 
 his excellent heart, and polite manners, is in- 
 creased by the regret for his misfortunes, during 
 a revolution which at length destroyed itself, by 
 ruining even the natural and eternal aristocracy 
 of talents; so that the members having, as it 
 were, extinguished the eyes, were of course re- 
 duced to darkness and perdition. 
 
 " The hill of Montmartre is elevated about 
 forty fathoms above the level of the Seine. The 
 summit is covered with vegetable earth, under 
 which is a bed of sand, mixed with rolled flints. 
 This is seated on layers of marl, of different 
 colours and thickness: this marl precedes and 
 accompanies horizontal beds of gypsum. 
 
 " The quarries of Montmartre may be consi- 
 dered as divided into three successive large beds, 
 or masses. 
 
 " The first, called haute-masse by the work- 
 men, is often more than fifty feet thick; it pre- 
 sents beds placed one on the other, without any 
 sensible interruption, although separated : they 
 are seated on a bed of bluish argil, spotted, about 
 twelve feet thick. This argil is intermixed with 
 marl. 
 
 " The second part is called pierre franche. 
 This gypsous mass, which is nearly fourteen 
 
MODE IX. GYPSUM. 489 
 
 feet thick, is disposed in contiguous layers, re- 
 posing on marl. 
 
 " The third part, called basse-carrilre, pre- 
 sents a gypsous mass of about fourteen feet, 
 divided into six heds, separated from one another 
 by layers of marl. This last part is in the plain, 
 and is incumbent on limestone. 
 
 " I shall riot undertake to account for the 
 formation of the gypsous hill of Montmartre, as 
 well as those which are contiguous, and form a 
 chain of eight or ten leagues, in a northern di- 
 rection. Among the naturalists who have writ- 
 ten on the quarries of Montmartre, M. Pralon, 
 and the Chevalier de Lamanon, have, among 
 others, given excellent lithological descriptions 
 of this place. The latter affirms, that in this 
 part of the Isle of France there was a lake of 
 gypsous water, which gave birth to these quar- 
 ries. 
 
 " The gypsous hills of Montmartre, Belle- 
 ville, Pantin, and all those of this part of the Isle 
 of France, are incumbent on quarries of lime- 
 stone; the gypsous mass only extending to the 
 level of the soil. The shelly and argillaceous 
 rock which is found on the summit of the hill of 
 Montmartre contains white shells, brittle, of the 
 class of chamites, and screw-shells : these shells 
 e analogous to those which are found in the 
 
 1 
 
DOMAIN V. CALCAREOUS. 
 
 river Marne, and in the rivulet of the Gobelins, 
 as is observed by Lamanon. 
 
 "Infiltrations of black martial earth* often 
 , form very elegant dendrites, on white limestone, 
 mixed with argil. The dissolution of the lime- 
 stone, infiltrating between the clefts of the gyp- 
 sous masses, forms stalagmites composed of un- 
 dulating layers, often distinct by their shades of 
 brown, yellow, and white. These alabasters vie 
 in beauty with the best of this kinds but hitherto 
 they have only been found in thin pieces, often 
 several feet in length. The limestone which in- 
 filtrates into the gypsous masses, is the cause 
 that they almost all effervesce with acids ; ex- 
 cept the plaster-stone with a coarse grain, the 
 crystals of selenite, and those known by the 
 name of gn 'guards, a term bestowed on selenite 
 when it forms regular layers. When these 
 masses are broken with the hammer, they emit 
 a strong odour of decomposed liver of sulphur. 
 
 " The marl forms beds and masses, more or 
 less considerable, in the plaster- quarry of Mont- 
 martre: argil is also found in it in considerable 
 quantity, and in different states: one is tena- 
 cious and ductile; the other exfoliates in drying, 
 and sticks closely to the tongue when tasted. 
 
 * Rather manganese. 
 
MODE IX. GYPSUM. 4$ 1 
 
 " Heavy spar* is found in the marl at Mont- 
 martre : it is more abundant in the hill of Belle- 
 ville, where it is met with in misshapen masses, 
 greyish, flattened and rounded, at ten or twelve 
 feet from the surface of the earth. 
 
 <* The trunk of a tree agatised, which I found 
 at Montmartre in 1778, serves to support my 
 theory on the agatisation of vegetable sub- 
 stances. See page 168, vol. ii. of my Chemical 
 analysis of the three kingdoms. This agatised 
 trunk of a tree was thirty feet long, and nine 
 inches in diameter; it was rather compressed, 
 lying horizontally from north to south, and was 
 at least 100 feet from the summit of the hill, be- 
 tween the two lowest beds of gypsum, of which 
 the interior part was crystallised. The inter- 
 stices of this agatised wood are ornamented with 
 little regular rock crystals, of various colours. 
 A part of this wood is brown and compact : this 
 colour is owing to iron and oil, principles of the 
 woody substance. I have inquired, since then, 
 if any agatised wood had been found at Mont- 
 martre, and I was assured that it had not. 
 
 " The shelly sandstone which is found at 
 Montmartre, seems of the same date with the 
 agatised wood : this sandstone contains white 
 
 * Strontian. 
 
492 DOMAIN^V. CALCAREOUS. 
 
 calcareous muscles and clams. For the most 
 part, it only presents the impression of these 
 shells. In regard to the sand and flint, which 
 are found in the upper layers of the hill of 
 Montmartre, they have no peculiar character, 
 and do not appear to differ from those found on 
 the sides of rivers ; but in the masses of gypsum 
 is found whitish silex, striped, and formed in 
 this quarry, like the masses of shelly sandstone. 
 " In the hill of Belleville, two feet from the soil, 
 are found black flints, in beds formed in irregu- 
 lar heaps; they lie in a kind of marl, which 
 reposes on a bed of gypsum of ten or twelve 
 feet, the layers, which are of different thickness, 
 being intermixed with marl : this layer of gyp- 
 sum lies on a considerable bed of green argil, 
 under which the gypsum is again found*. 
 Bones. <c The bones which are discovered in the 
 gypsum, have undergone no other alteration 
 than that effected by time: the greater part 
 have a yellowish tinge. M. de Joubert has ob- 
 served, that these bones are always surrounded 
 with a kind of marl, which he regards as being 
 produced by the decomposition of the soft parts 
 of animals. In the cabinet of that naturalist 
 
 * This green clay corresponds with that of the river Marne. 
 which is green. It contains iron. See Vauquelin's analysis. 
 
MODE IX. GYPSUM. 
 
 there are icthyolites; the impression of the fish 
 being compressed, as in schistus : nor are the 
 fish solid, as in limestone. 
 
 " M. d'Arcet possesses an ornitholite, or pe- 
 trified bird, which he found, in 1781, twenty 
 fathoms below the summit of Montmartre *. 
 
 " It has not yet been decided to what species 
 of animals the bones found in gypsum belong. 
 If these bones are neither agatised, nor pene- 
 trated with gypsum, it is because the absorbent 
 earth, which forms their base, is found to be 
 combined with phosphoric acid, and a fat sub- 
 stance j-j consequently the selenitic water has 
 not been able to decompose these bones. 
 
 " The brown hepaltic iron ore, solid, in an 
 irregular mass, which is found dispersed in some 
 places in the hill of Montmartre, seems to be 
 the product of decomposed pyrites. 
 
 " The calcareous and gypsous Iudi 9 in a 
 spheroidal mass, flattened, called by the work- 
 men miches de quatorze sous, are found to the 
 east of Montmartre, near Clignancourt, in a bed 
 of marl, from twelve to fifteen feet below the 
 summit of the hill. Among the ludi of this 
 kind, which are in the cabinet of the royal 
 School of Mines, there is a spheroidal mass, 
 
 * It seems to be a water-rail. 
 
 \ The acidum pingue is a favourite teet of M. Sagc> 
 
494 DOMAIN V. CALCAREOUS. 
 
 flat, of two feet diameter, and seven inches 
 thick; all the exterior crust is calcareous, gra- 
 nular, greyish, and a little argillaceous : it is an 
 inch and a half thick. The interior of this Indus 
 is filled with gypsous prisms, greyish, penta- 
 gonal and hexagonal, with interstices between 
 them. These prisms are two or three inches in 
 height, and one in diameter; their surface is 
 strewed with small brilliant crystals. 
 
 " The farinaceous gypsum, or white gypsous 
 earth, is sometimes found in the form ofguhr^ 
 but the crystalline gypsum forms considerable 
 beds : they are often intermixed with grignards* 
 or crystals of selenite, forming continued layers. 
 Lenticular selenite is found in the marl : these 
 crystals, grouped in different ways, have been 
 precipitated from the aqueous fluid which held 
 them in solution; the marl, which has after* 
 wards settled, has encrusted, surrounded, and 
 protected them. They are found in great quan- 
 tities at the foot of Montmartre, towards Mou- 
 ceaux. 
 
 " Basaltic selenite, or in hexahedral prisms, 
 with trihedral summits, alternate, with a curved 
 surface, is found in the marl, near the summit 
 of the hill of Belleville. 
 
 " Prismatic decahedral selenite, produced by 
 the elongated octahedron, truncated near its 
 
MODE IX. GYPSUM. 495 
 
 basis, is very scarce at Montmartre; but is 
 common in the hill of St. Germain-en-Laye, 
 where it is found in grouped crystals, spread in 
 a red veined clay, which precedes the beds of 
 limestone, found towards the summit of the hill. 
 
 " At Montmartre I also found striped sele- 
 nite, in small layers of two or three lines in 
 thickness." * 
 
 One of the most singular discoveries made at 
 Montmartre was a horse-shoe, partly corroded 
 by age ; but more than the half remains with 
 the holes very distinct. It is said to have been 
 found at a great depth in the solid mass, and 
 had most probably dropped into a reft, after- 
 wards filled by stalactitic matter, a common ap- 
 pearance in gypsous regions. 
 
 Fossiie bones did not attract so much curi* 
 osity when they were carelessly examined, and 
 supposed to belong to known animals. But the 
 singular discovery in South America of the en- 
 tire skeleton of an animal larger than the ele- 
 phant, and of quite a different genus, and now 
 totally extinct f, led to more minute investi- 
 gations and comparisons, till it was at length 
 
 Sage, Supplement a la Description Methodique du Cabinet 
 de 1'Ecole Royale des Mines. Paris 1787, 8vo. p. 124. 
 
 f See the print, Faujas, Essai de geologie, from the large plates 
 engraved by order of the King of Spain, 
 
DOMAIN V. CALCAREOUS. 
 
 discovered by microscopic eyes, that even the 
 insects found in amber are not of the European 
 kinds, but belong to distant regions. In the 
 comparative anatomy of fossile bones, the cele- 
 brated Cuvier greatly distinguished himself, and 
 by patience and research has nearly completed 
 three skeletons of those found at Montmartre. 
 For they belong to three kinds of animals, of the 
 same genus, but of very different stature ; one 
 only attaining the size of a hare, the second of 
 a hog, while the third reaches the size of the 
 horse. Those animals approached the nature of 
 the rhinoceros, the hog, and the American ta- 
 pir, but were more nearly allied to the latter. 
 Being herbivorous, as appears from the teeth, 
 easily distinguishable from those of carnivorous 
 animals, their bones seem to have been rolled 
 down by the river to the spot where they are 
 now found. 
 
 shells. It might be imagined, that there is a kind of 
 artful malice, if the expression may be pardoned, 
 in the bosom of the goddess Nature, which 
 allows human theory to sport for some time, 
 and then brings out her stores for its destruction. 
 It was long conceived, that fossile shells were 
 confined to limestone, and fossile bones to gyp- 
 sum, till very lately most of the sea-shells, found 
 in the highest state of preservation in a bed of 
 
MODE IX. GYPSUM. 497 
 
 sand at Grignon, about four leagues beyond 
 Versailles, have also been discovered in the gyp- 
 sum of Montmartre. Most of the shells found 
 at Grignon, some of which retain their most de- 
 licate spines, and even their colours, are known 
 now to belong to the South Sea, a portion of the 
 Grand Ocean falsely called the Pacific; and 
 but few to the Atlantic, or even the Mediter- 
 ranean. 
 
 The various beautiful kinds of selenite, or 
 crystallised gypsum, found at Montmartre, be- 
 long to lithology. The curious kind called ve- 
 getable selenite, from its resemblance to vegeta- 
 tion, seems confined to Derbyshire. 
 
 
 
 Aspect 1. Common gypsum, from Montmartre. 
 
 The same, with selenite, often elegantly inter- 
 spersed with farinaceous gypsum. 
 
 The same, with blue variegated clay. 
 
 The same, in small layers of marl, &c. forming, 
 as it were, a Montmartre in miniature. 
 
 The same, with imbedded ossilites, or bones of 
 quadrupeds and birds. 
 
 The same, with various sea-shells ; a recent and 
 curious discovery. Brongniart says that some of 
 the marl beds contain cardites, venerites or dion- 
 ites, tellenites, cerites or screws (turbinites), and 
 
 VOL. i. 2 K* 
 
4Q8 DOMAIN V. CALCAREOUS. 
 
 even bones of fish, and trunks of the palm-tree. 
 Small pieces of iron-stone also appear, particu- 
 larly on that side where the gypsum once bore a 
 prismatic form, now destroyed by the progress of 
 the quarriers, and which probably arose from the 
 influence of that metal. 
 
 Aspect 2. Grey gypsum, from Mount Cenis* 
 The same, from Germany. 
 
 MODE X. ALABASTER. 
 
 Characters. Texture, compact, generally saline, but fine- 
 grained ; sometimes fibrous, even in large masses. 
 
 Hardness, gypsic. Fracture, even, sometimes 
 scaly. Fragments, amorphous, rather blunt. 
 
 Weight, oarbonose, sometimes granitose. 
 
 Lustre, glimmering. Sometimes translucent, 
 even in pretty thick pieces ; often only on the 
 edges. 
 
 The colour is generally of the purest white, 
 sometimes slightly veined with grey : but when 
 stalactitic, it may be veined with yellow and 
 brown, by ferruginous infiltrations. In small 
 veins it may assume a rose colour, as at the Old 
 Passage, near Bristol, where it is however too 
 
MODE x. ALABASTER. 499 
 
 soft to be polished. It may also, like that near 
 Nottingham, appear blue when held between 
 the eye and the light. 
 
 It is now proper to pass to the consideration 
 of that fine compact gypsum called alabaster. 
 This substance, like alabastrite, is regarded as 
 being a sinter , or deposition; but from gypsous 
 rocks. Hence it is commonly found in small 
 layers, and being rather soft, is used for little 
 statues and ornaments. Yet Gmelin, who has 
 ranked it under gypsum, assures us that it forms 
 entire mountains, or at least very large strata, in 
 Thuringia and Siberia*; but he probably con- 
 founds it with alabastrite, the ancient or cal- 
 careous alabaster. If, as Mr. Kirwan asserts, 
 even mountains of gypsum are foundf, alabaster 
 may fill prodigious caverns. While Werner and 
 his disciples are perhaps too minute in lithology 
 and metallogy, they are in petralogy far too 
 theoretic and general : but if gypsum be found, 
 as they assert, in rocks distinguishable by their 
 white colour, they must belong to alabaster. 
 In fact, what has been styled primitive gypsum, 
 particularly the cubic of Salins, Mont Blanc, is 
 the purest alabaster; and naturalists ought to 
 attend to common distinctions, and the purposes 
 
 * Linn. 118. 
 
 t Geological Essays, 238. 
 
 2 K2 
 
500 DOMAIN V. CALCAREOUS. 
 
 of art and utility, else the sapphire and the ruby 
 might be confounded with corindon. It may 
 seem particularly doubtful whether the kind 
 called anydrous by the French mineralogists, 
 because it contains no water of crystallisation, 
 can properly be regarded as a sinter, or depo- 
 sition from other beds \ particularly that of Vul- 
 pino, which contains silex, and has been quar- 
 ried for many ages. If gypsous alabaster form 
 beds, which alternate with orsten and limestone, 
 it cannot be regarded as the mere production of 
 other rocks. 
 
 Mr. Jameson, who deserves to be mentioned 
 ivith respect, upon account of his assiduous ser- 
 vices to mineralogy, in treating compact gyp- 
 sum, observes, that " it occurs almost always 
 ash grey, passing into smoke grey, also yellow- 
 ish grey;" and closes thus, " It is employed in 
 architecture and sculpture, under the name ala- 
 baster." Nothing surely can be more contra- 
 dictory to the common sense of mankind, except 
 Mr. Werner's new and elegant appellation of 
 White-stone, thus introduced to his audience by 
 a German Professor, " White-stone is always 
 grey." The ingenious and intelligent Brard, 
 though a mere youth, gives a more rational ac- 
 count. 
 amount " Gypsous alabaster does not effervesce in 
 
MODE X, ALABASTER. 501 
 
 nitrous acid; it loses its transparency, its lustre, 
 and solidity, when exposed to fire; that is to 
 say, that it changes into plaster. 
 
 " It is so soft as to be marked with the nail, 
 and yet it takes a pretty fine polish ; but it is 
 true that the least friction will destroy it. 
 
 " It is never decked with lively colours; 
 milk-white is its colour by excellence. 
 
 " Its transparency is sensible, even through 
 thick plates. 
 
 " In short, its fracture or internal aspect va- 
 ries much ; sometimes it presents a crystalline 
 and bright tissue, sometimes only a laminar con- 
 texture, or at other times only a dull and com- 
 pact surface. 
 
 " As gypsous alabaster is much oftener white 
 than calcareous alabaster, it is to that kind that 
 the old proverb should be applied of white as 
 alabaster."* 
 
 He informs us that the statues of the superb Monuments. 
 mausoleum of the Constable Lesdiguieres, in the 
 cathedral of Gap, are of gypsous alabaster, from 
 Boscadon, near Embrun, in the department of 
 the Upper Alps. It is probable that those in 
 the English cathedrals, generally executed by 
 foreign artists, are of Italian alabaster. The 
 
 P. 468. 
 
502 DOMAIN V. CALCAREOUS. 
 
 alabaster of the department of Mont Blanc, of 
 the most beautiful white, sometimes veined with 
 grey, and receiving an exquisite polish, is much 
 employed at Grenoble, the Gratianopolis of an- 
 tiquity, and the chosen seat of Venus and 
 Apollo. 
 
 Anydrous. The alabaster called anydrous is of several 
 colours, white, rose, grey, and even blue, which 
 is called celestine, a name now strictly belong- 
 ing to a kind of strontian. The white anydrous 
 kind is also found at Vizil, near Grenoble; and 
 was used by the Romans, as appears from the 
 beautiful mile stone, or rather column, at Thin, 
 on the banks of the Rhone, which is six feet 
 high, and erected in the time of Aurelian*. 
 
 Anydrous alabaster, mixed with a considera- 
 ble quantity of silex, forms the bardiglio of the 
 Italians, found near Vulpino, fifteen leagues 
 from Milan, and employed in making columns, 
 tables, and vases. It properly belongs to the 
 Diamictonic Domain, where it is more particu- 
 larly described. 
 
 White alabaster, from Derbyshire. 
 
 With a blue transparency, from Notting- 
 ham. 
 
 White alabaster, from the lower Pyrenees. 
 
 * Ib. 473. 
 
MODE X. ALABASTER. 503 
 
 Yellowish white alabaster, from Lagny, about 
 twenty miles from Paris, where it is used for 
 columns and vases. It is translucent, and full of 
 little cracks, which however do not affect its 
 solidity. 
 
 Bright grey alabaster, with green and yel- 
 lowish spots, from the river Niso, in Sicily; 
 which affords many curious marbles, and other 
 substances. 
 
 Gypsous alabaster, waved with red and deep 
 yellow; from Taormina, in Sicily; another re- 
 markable spot for a variety of marbles and ser- 
 pentines, some of which were known to the 
 ancients. 
 
 Translucent alabaster, of a bright yellow 
 waved with white; from the isle of Gozzo, near 
 Malta. 
 
 Travellers seldom observe whether a substance 
 be found in such abundance, as to be useful to 
 the arts. Hence even celebrated cabinets are, 
 in the present confusion of the science, filled 
 with specimens from little fragments, or boul- 
 ders, and vein-stones, which merely please the 
 eye, and lead to no solid purpose of utility or 
 science. A final and perpetual division into li- 
 thology and petralogy, would obviate this among 
 many other inconveniences. 
 
 Anydrous alabaster, from G;enoble. 
 
504 ' DOMAIN V. CALCAREOUS. 
 
 MODE XL CHALK. 
 
 Characters. Texture earthy, rather fine, on a large scale 
 generally stratified, with interposed layers of 
 detached flints at regular intervals. The flint is 
 sometimes schistose and continuous, as in the 
 neighbourhood of Margate, and the North Fore- 
 land. 
 
 Hardness, of course, cretic. Fracture, even, 
 earthy. Fragments amorphous, blunt. 
 
 Weight, pumicose. 
 
 Lustre, dull. Opake. 
 
 The colour is a dull white, proverbially known, 
 but, wanting the brightness of alabaster, has 
 never been used to celebrate the charms of 
 beauty. From the decomposition of the balls 
 of iron pyrites, which it often contains, it may 
 in parts assume a yellowish or greyish tint. 
 Sites. Chalk not only forms rocky cliffs, of a most 
 regular, bright, and imposing aspect; but may 
 be said to constitute whole regions. A large 
 portion of the south of England, and the north 
 of France, consists of chalk ; which, in Hamp- 
 shire and Kent, is often covered with the hop ; 
 and in Champagne affords a light vivacity to the 
 vine. It also appears in the flat islands of Den- 
 
MODE XI. CHALK. 505 
 
 mark ; while, in other countries, it must rather 
 be regarded as a rare production. This extent 
 of chalk in a N. E. direction, and its absence in 
 the other parts of the world, is a most grand 
 and singular geological fact, which does not 
 seem to have invited deserved attention. 
 
 Mr. Jameson's account is so concise and 
 exact, that its insertion will please the reader. 
 
 " 1. This appears to be one of the newest of Jameson'* 
 
 account. 
 
 the floetz formations, and is nearly the last link 
 of the great limestone series. 
 
 " 2. It is very simple; for it contains, besides 
 chalk, only a small portion of flint. The flint 
 occurs in tuberous shaped masses, or in the 
 form of petrifactions imbedded in the chalk ; 
 and sometimes it forms thin beds, which are 
 more or less continuous, and alternate with 
 thicker beds of chalk. It contains but few pe- 
 trifactions, and these are principally echinites, 
 ostracites, and belemnites. 
 
 " 3. It is more or less distinctly stratified. 
 Like all new formations, it contains but few 
 metalliferous fossils. All that have been hitherto 
 found, are iron pyrites in small balls, and small 
 portions of iron ochre. 
 
 " 4. Very few observations have been hitherto 
 made, with the view of ascertaining its relative 
 antiquity. Its occurrence on the sea-coast, and 
 
506 DOMAIN V. CALCAREOUS, 
 
 its earthy aspect, point out the lateness of its 
 formation. 
 
 " 5. It occurs only in low situations, and most 
 frequently on sea-coasts, where it forms con- 
 siderable cliffs ; but when it occurs in inland 
 situations, it rises into hills of considerable 
 height. 
 
 " 6. In England, it extends through Wilt- 
 shire, Hampshire, Surry, Middlesex, Essex, and 
 Kent; and appears on the opposite coast of 
 France, and stretches through the Netherlands. 
 In the Baltic, it occurs in the islands of Zealand, 
 Moen, Rugen, Wollin, and Saltholm ; and it ex- 
 tends from Saltholm to the Swedish province 
 Schonen. According to Dr. Steffens, the chalk 
 at Stevens-klint in Zealand, and that of Moen, 
 rests upon an aggregate of nautilites, serpulites, 
 chamites, and corallites." 
 
 To the petrifactions may be added vast de- 
 composed ammonites, as at Margate, pectenites, 
 large pinnites, as at Meudon, near Paris, the 
 glossolites or glossopetrse, called petrified pa- 
 lates, often of a In-ight brown and great beauty * ; 
 with what are called Judaic stones, seemingly 
 spines of a large sea-urchin, dionites, &c. It 
 has been remarked that the petrifactions in chalk 
 
 * See Woodward and P. Tr. No. 232. 
 
MODE XI. CHALK. 507 
 
 seem more ancient than those in many lime- 
 stones ; and Brongniart has observed that they 
 are chiefly pelasgian. The shells are often 
 changed into flint, particularly the echinites. 
 Sometimes unaccountably the shell retains its 
 original appearance, and even lustre when 
 broken; while the interior is a mass of solid 
 flint, which has also been found to pass through 
 the shell without affecting its texture, which 
 could not have happened if the flint had been in 
 a state of fusion from. heat. 
 
 Patrin informs us, from ButTon, that a chalk 
 region is also found in Poland ; but he adds par- 
 ticularly in the territory of Sadki, where it is 
 only found above an iron mine, with beds of 
 other substances. This may perhaps be a soft 
 white limestone, like that sometimes used at 
 Lyons, and which has also been employed in 
 building the famous bridge of St. Esprit over the 
 Rhone. Some regard this last as a highly in- 
 durated chalk, which may be cut with a common indurated, 
 saw, and becomes, like most other stones, more 
 solid by exposure to the air, 'losing what the 
 quarriers call the rock water. 
 
 There is, on the other hand, a kind of chalk, 
 which may be regarded as crude and imperfect, 
 often consisting merely of comminuted shells; 
 
508 DOMAIN V. CALCAREOUS. 
 
 and such are the falunes of Touraine, and other 
 parts of France. 
 
 Uses. Its use, as a manure, seems to have been long 
 
 known; and the numerous chalk-pits in Eng- 
 land, sometimes of vast extent, have been dug 
 for this and other purposes. When cleared by 
 water from foreign particles, it is allowed again 
 to condense, and sold under the name of whiten- 
 ing. Spanish white is merely refined in this 
 manner ; and the name is arbitrary, as it is manu- 
 factured in the north of France. Spanish white 
 not having the poisonous qualities of white-lead, 
 there is room to regret that it is not brought into 
 more general use. Such are, it is believed, the 
 chief consumptions of chalk ; the use of which 
 is rather condemned at the alehouse > but it is 
 also sold at the shops for many domestic pur- 
 poses. In Woodward's time, the British seamen 
 Chalk eggs, generally carried chalk eggs from Kent, being 
 echinites, supposed to contain the purest kind. 
 They were used to correct sickness, diarrhoea, 
 and other disorders of the stomach, arising from 
 salted or gross food ; and the absorbent powers 
 would be approved by the modern physician, 
 especially if chalk contain 11 of magnesia, as 
 asserted by Bouillon Lagrange ; but other che- 
 mists have only found about 60 of lime, and 40 
 
MODE XII. TUFA. 50Q 
 
 of carbonic acid*. The chalk-stones which ap- 
 pear at the joints of gouty persons, and greatly 
 resemble that substance, are now said only to 
 consist of uric acid and soda. 
 
 The structures and aspects of chalk, are rather 
 various in minute parts, than in general masses 5 
 so that an excess of precision in this respect 
 might, as sometimes happens, only introduce 
 erroneous ideas. 
 
 Chalk, with various shells ; from many parts 
 of England, France, and Denmark. 
 
 The same, with the shells in flint. 
 
 The same, with balls of pyrites divergingly 
 radiated. 
 
 MODE XII. TUFA. 
 
 The name of calcareous tufa, is most justly Description. 
 applied to a light and porous rock, gradually 
 formed and daily increasing by the depositions 
 of springs and streams much impregnated with 
 stony matter. It is, of course, the newest of all 
 the mineral productions ; and often contains 
 
 * Da Costa, p. 77, says that chalk, called creta, from Crete, 
 where it is found, as it is, among other places, in the archbishopric 
 of Cologne, is used for the heartburn and diarrhoea. It is also 
 employed in manures, to cleanse metals, and in baking sugars. 
 
510 DOMAIN v. CALCAREOUS. 
 
 moss, grass, and other vegetables. The forma- 
 tion in many instances is so rapid, that it is ap- 
 vr y modern, plied to the purposes of art. Nests of birds, 
 and other small objects, are subjected to the 
 stream ; and, when covered by the deposition, 
 are said to be petrified ; an erroneous idea, for 
 they are merely clothed with tufa. Such is the 
 tufa common on the banks of the Tees, and 
 other rivers in the north of England. By its 
 lightness it is well calculated for vaults and roofs 
 in buildings, where the use of wood would be 
 dangerous; and, by its open intervals, admits 
 the mortar, so as to form as it were one coherent 
 mass ; and it was used by the ancients in many 
 constructions. The Pharos, at Dover, is chiefly 
 built of tufa, from the north of England*. 
 
 But as the Italians first used the word tufo, 
 and seem more generally to have applied it to 
 volcanic accretions, there is no impropriety in 
 extending it, as is often done, to many loose 
 and porous stones, evidently of recent forma- 
 Conchitic. tion. Thus the shelly tufa of Gmelin, consist- 
 ing of broken fragments of shells, with sand and 
 gravel, loosely joined by a calcareous cement, 
 might perhaps be more properly classed here 
 
 * This tufa seeming to join substances together, was exhibited by 
 the surgeons in. the fracture of boaes, and called osteecolla. 
 
JfclODE Xn. TUFA. 5U 
 
 than among the glutenites. Of this stone the 
 celebrated temple of Jupiter Otympius at Agri- 
 gentum, or Girgenti, in the south of Sicily, was 
 constructed, as appears from the ruins. The 
 coarse limestone of Saillancourt, used in build- 
 ing the beautiful bridge at Neuilly near Paris, 
 also approaches to this kind. 
 
 The Travertine, with which the church of St. 
 Peter, at Rome, is constructed, is also a tufa, 
 daily formed in the waters of the Anio, now 
 called the Tiverone. 
 
 A fine calcareous tufa is also formed in an- ofaqueduct*. 
 cient aqueducts, in like manner as we see it 
 every day in our tea-kettles. The ingenious 
 Brard says, " Being in Languedoc, towards the 
 middle of June, 1807, 1 visited the great Roman 
 aqueduct, known by the name of Pont du Card: 
 I ascended into the gallery which terminates this 
 bold monument, and in which, anciently, the 
 water ran which was conducted from Uzes to 
 Nismes : I observed that the sides and bottom of 
 this canal are encrusted with coarse tufa, 18 
 inches thick. In like manner also, and what 
 has happened under the eyes of the Parisians, 
 m when in new modelling the garden of the senate, 
 there was found, in digging the soil, canals; 
 which are said to be as ancient as the time of 
 Queen Blanche, and which brought the water 
 
DOMAIN V. CALCAREOUS. 
 
 from Arcueil to Paris; and these canals werft 
 entirely filled with the same sediment which 
 that water deposes, even now, on the surface 
 of all bodies on which it remains a certain 
 
 Some establish a distinction between tufa and 
 sinter ; that the former is deposited in the open 
 day, while the latter is formed under ground. 
 But this seems arbitrary ; and depositions of the 
 purest alabaster, or alabastrite, may be equally 
 formed in the open air, as at the Baths of St. 
 
 st.Feiippe. Philip, in Tuscany, where they appear equal to 
 the most beautiful marbles, being received in 
 moulds with the heads of Roman Emperors, and 
 other objects. This ingenious manufacture was 
 established by Mons. Vegni. But such objects 
 belong to lithology ; and the name of tufa will 
 ever imply a coarse stone used in architecture. 
 
 Travertine. Of this kind, by far the most celebrated is the 
 travertino, already mentioned; as it has been 
 employed, both in ancient and modern times, in 
 the construction of the most magnificent edi- 
 fices of the most magnificent city in the worldf . 
 Hence a more particular account will be found 
 
 * Brard, 466. 
 
 f For example, the Coliseo or Flavian amphitheatre. Petrini, 
 i. 138, says the Travertino is of a sweet yellowish white, and 
 hardens by time. 
 
MODE XII. TUFA. /J13 
 
 interesting, and shall be given in the words of a 
 skilful observer. 
 
 " The Anio or Tiverone, which descends from 
 the Apennines of Vicovaro and Subiaco, to the 
 east of Rome, before reaching the plain where it 
 unites with the Tiber, crosses Tivoli ; a place 
 equally known to the learned and the artist, by 
 its ancient monuments and its beautiful views* 
 which have employed the pencils of the greatest 
 masters. All the land through which the Anio 
 passes in Tivoli, whether near the great cascade 
 or the smaller ones, is filled with masses of a 
 calcareous stone, produced by the deposition of 
 its waters. Sometimes a piece of rush or reed, or 
 other vegetable matter, is the first point to which 
 the calcareous earth begins to attach itself. It 
 generally deposes in concentric layers, and has 
 the hardness and fibrous tissue of alabaster. 
 These layers are nevertheless separated by a bed 
 of calcareous earth, friable, yellowish, and very 
 fine. At the foot of the mountain of Tivoli, 
 where the Anio enters the plain, which extends 
 to Rome, are the quarries of travertine. This 
 calcareous rock is disposed in horizontal beds : 
 its colour is yellowish white, its grain earthy, 
 fracture uneven, and its hardness far surpasses 
 that of those calcareous masses produced by the 
 Anio, in the neighbourhood of Tivoli. Cavities, 
 
 YOL. i. 2 i. 
 
DOMAIN V. CALCAREOUS. 
 
 where the calcareous substance has assumed a 
 sparry grain, and stalactitic forms, are common 
 in travertine. Sometimes these cavities have 
 been since filled by a calcareous stalactite, 
 whiter, of a finer grain and harder. This is the 
 origin of those white spots; the regularity of 
 which, has caused them to be mistaken for ma^ 
 rine bodies enveloped in its paste. Travertine 
 contains no remains of marine substances ; but 
 sometimes it affords fragments of vegetables. 
 
 " It is not doubted but travertine owes its 
 origin to the depositions of the Anio ; deposi- 
 tions which, in the plain, may have formed a 
 more solid and compact rock; because its cur- 
 rent was less rapid, and perhaps its waters more 
 stagnant in several places. Not far from the 
 quarry of travertine is the Solfatara, so called 
 on account of the great heat of its waters, which 
 abound in sulphuric hydrogen gas, and form a 
 considerable sediment of calcareous matter. A 
 Cardinal d'Este caused the canal to be dug; 
 which conveys the waters of the lake to the 
 Anio. The calcareous depositions are there so 
 abundant, that, if every three years it was not 
 cleaned out, it would be closed up, notwith- 
 standing its breadth and depth. The water 
 which runs in the canal, on meeting with bits of 
 rush or other bodies, covers them with a white 
 
MODE XII. TUFA. 515 
 
 calcareous crust, two or three lines in thickness. 
 These incrustations are known by the name of 
 Comfits of Tivoli*. Before this passage was 
 opened, the overflowings, to which the lake is 
 subject, were often so considerable that the water 
 spread over the neighbouring grounds, and 
 formed on their surface a stony crust. The 
 water of the lake so charged with calcareous 
 earth, uniting with those of the Anio, in the 
 floods which their union must produce, have 
 themselves contributed to the formation of tra- 
 vertine. I do not think that the Anio alone 
 would have been capable of forming the quan- 
 tity which is found of that rock. 
 
 " Independent of the immense quarries work- 
 ed by the ancients, there are besides others of 
 such vast extent, that they may supply the de- 
 mands for many ages. 
 
 * " Dr. Vegni had established there a manufacture of bas-reliefs, 
 analogous to that which he possesses in Tuscany, near the Baths of 
 St. Philip. The ingenious method by which he forces the water to 
 form the bas-reliefs in a short time, which by the exactness of the 
 design and the hardness of the stone, are not inferior to the originals, 
 is sufficiently known by the relations of most modern travellers in 
 Italy. 
 
 " I shall only add, that the colour, grain, and hardness of the 
 stone formed by the waters of the Solfatara of Tivoli, as well as the 
 neighbourhood of Rome, which furnishes so many beautiful models, 
 and skilful artists, give this manufacture a decided advantage over 
 that of Tuscany." 
 
 2 I, 2 
 
DOMAIN V. CALCAREOUS. 
 
 " The lake of Solfatara seems to have greatly 
 assisted in the formation of this rock. Its water, 
 charged with much gaz, explains by that qua- 
 lity the great number of hollows which travertine 
 presents. It proves that when the rock harden- 
 ed, a gaz has at the same time escaped in several 
 places, which has prevented the approximation 
 of its parts which were still soft. As often as 
 the interior of a mass of rocks presents cavities, 
 without any indication of foreign substances, 
 which might have opposed the union of its parts, 
 I conceive their origin may be attributed to the 
 escape of gaz, at the moment when the sub- 
 stance was passing from a state of softness to 
 solidity, by cooling or drying. 
 
 " From what I have just shown, it follows that 
 travertine, or rock of Tibur or of Tivoli*, is a 
 carbonate of lime, formed by the depositions of 
 the Anio and the Solfatara of Tivoli. The 
 Roman artists give the name of travertine only 
 to the stone taken from the quarry, situated at 
 the foot of the mountain of Tivoli. The litho- 
 logists, less slaves to locality, bestow it on all 
 calcareous rocks which possess the grain, tissue, 
 and formation analogous to that of the traver- 
 tine of Tivoli. If the ancient and modern 
 
 * Tilurtinum of the ancients. 
 
MODE XII. TUFA, 517 
 
 Romans have employed this stone in the most 
 noble structures, they have but followed the ex^ 
 amples of other people before them. The tem- 
 ples of Pestum, the most ancient monuments 
 that are known after the pyramids of Egypt, 
 were built with a travertine, formed by the de- 
 position of waters which still exist in that dis- 
 trict. This stone, when long exposed to the 
 air, acquires a considerable degree of hardness ; 
 its colour assumes a reddish tinge, pleasing to 
 the eye, and which in no small degree contri- 
 butes to bestow on monuments of antiquity that 
 majestic character which is so striking. Buch 
 justly observes, c that the temples of ancient, 
 the churches and palaces of modern, Rome, 
 would infinitely have lost of their grandeur and 
 majesty, if the bold genius which erected them 
 had not met with such a material as travertine. 
 They would have lost much of their solidity, if 
 the formation of tufa had not given rise to the 
 discovery of puzzolana.' The chance which 
 collects in its vicinity the materials most fit for 
 architecture, travertine, and puzzolana, was not 
 a little happy for Rome. The mortar or cement, 
 which results from a mixture in just proportion 
 of that ferruginous volcanic earth with lime, so 
 much surpasses in hardness all other known 
 
DOMAIN V. CALCAREOUS. 
 
 cements, that the exportation of puzzolana, by 
 the Tiber and the Port of Ostia, is become a 
 little branch of trade."* 
 
 From the preceding observations, it might 
 be understood that there are at least three dif- 
 ferent structures of the calcareous tufa : the 
 porous, or that of the travertine ; the shelly, like 
 that of the ruins of the temple of Jupiter; and 
 the tubular, like that of Germany, and the north 
 of England. 
 
 STRUCTURE I. POROUS. 
 
 Travertine, from the ruins of Rome. 
 The same, from the quarries near Tivoli. 
 
 STRUCTURE II. CONCHIT1C. 
 
 From the ruins of Agrigentum or Girgenti. It 
 is found in many other places, but has excited 
 little attention, being probably regarded as a 
 coarse limestone ; while its lax composition refers 
 it to this mode, though Wallerius would perhaps 
 have called it a-tufaceous limestone. 
 
 * Breislak, ii. 26 1. At Bionnay there are houses built of a cal- 
 careous tufa, containing fragments of lime-spar, limestone, and 
 slate; the base being of a lively brick red colour, and strongly effer- 
 vescent with acids. Sauss. 752. 
 
MODE XIII. CALCAREOUS INTRITE. 
 STRUCTURE III. TUBULAR. 
 
 From the tower, or ancient pharos, at Dover 
 Castle. 
 
 The same, from the banks of the Tees, and 
 other rivers in the north of England. 
 
 The same, encrustrating various objects, as 
 birds' nests, plants, leaves, c. 
 
 MODE XIII. CALCAREOUS INTRITE. 
 
 This mode is rare, and of little consequence, 
 especially as the stones are not remarkable for 
 beauty, and seldom used in the arts. 
 
 The most singular, is what Werner would call Porphyiitic. 
 a limestone porphyry ; being a compact lime- 
 stone of a reddish white colour, sprinkled with 
 minute crystals of white felspar. It was disco- 
 vered by Gillet Laumont, in the mountain called 
 Bonhomme, in the Alps. 
 
 Another calcareous intrite is a fine grained Marble of 
 
 Nonette. 
 
 limestone, with angular spots of calcareous spar, 
 something resembling a porphyry. It is of a 
 yellowish white colour ; and bears the name of 
 marble of Nonette, from a place situate at the 
 confluence of the rivers Alagnon and Allier, in 
 the department of Puy-de-Dome. There is also 
 
DOMAIN V. CALCAREOUS. 
 
 a conchitic marble found near the same place ; 
 but the former being more easily worked, is 
 preferred for chimney-pieces and other objects, 
 according to the information given me by M. 
 1-ucas, a most obliging and intelligent youth, 
 who has published some useful works on mine- 
 ralogy. The father has the care of the collection 
 of the Jar din des plantes ; and by his respectable 
 character, and gentle manners, prevented many 
 outrages that were offered to that sacred deposit, 
 during the times of anarchy. 
 
 MODE XIV. CALCAREOUS GLUTENITE, 
 
 This mode presents many important objects, 
 as the celebrated bricias and kollanites in mar- 
 ble, with the calcareous sandstones, used for 
 various purposes of construction. It falls, as 
 usual, under two divisions, the large grained and 
 the small. 
 
 STRUCTURE I. LARGE GRAINED. 
 
 Bricias of limestone are common at the bottom 
 of many calcareous hills, but attract little atten- 
 tion ; except in colour arid grain, they belong to 
 that noble mode called marble, A singular kind, 
 
MODE XIV. CALCAREOUS GLUTENITE. 
 
 described by Saussure, may suffice. He observed 
 it at the Col de la Seigne, near the mountain 
 of Bonhomme. 
 
 " On this road we find a quantity of fragments sfliguia 
 of a very singular calcareous bricia ; and conti- 
 nuing to ascend, we leave on the right, above the 
 path, the rocks from which these fragments are 
 detached. The same bricias are again found in 
 the same situation, on the opposite slope of the 
 Col de la Seigne, and in the White Alley : but I 
 shall describe them here, that I may not return to 
 them. The paste of these bricias is sometimes 
 white, sometimes grey ; and the fragments which 
 it contains, are some white, some grey, others 
 brownish red, and almost always of a different 
 colour from the paste which unites them. They 
 are all of a calcareous nature, at least such were 
 all those that I could see ; and it is remarkable 
 that they have all a lenticular form very much 
 flattened, and that they are all placed in the 
 direction of the plates of the rock : one would 
 say, on seeing them, that they had all been com- 
 pressed and bruised in the same direction. This 
 same stone is mixed with mica, especially in the 
 interstices of the layers, and between the frag- 
 ments and the paste which unites them ; but no 
 mica is observed in the fragments themselves. 
 
DOMAIN V. CALCAREOUS. 
 
 Infiltrations of quartz are also found in these bri- 
 cias. This rock is cut by frequent fissures, per- 
 pendicular to the planes of the beds. It is palpa- 
 bly seen, that these clefts have been formed by the 
 unequal subsidence of the beds, and not by a 
 spontaneous retreat : for the pieces, or foreign 
 fragments, are all divided, and distinctly cut by 
 these fissures ; while in the natural divisions of the 
 beds, these same fragments are entire, and pro- 
 jecting from the surface. The nodules of quartz, 
 and the several crystals which schisti contain, 
 present the same phenomenon ; and the same con- 
 sequence may be drawn from it ; they are divided 
 in the clefts, and whole in the separations of the 
 layers. 
 
 " Although these flattened fragments, as I have 
 said, afford, at first sight, the idea of compression, 
 yet I cannot admit it; no other vestige of this 
 compression being observable : I should rather 
 imagine that these fragments have belonged to 
 very thin layers, which have been rounded under 
 the waters, by rolling and friction ; that afterwards, 
 when they have been successively carried down 
 and lodged by the waters, they have taken the 
 horizontal position that their weight imposed on 
 them ; and that afterwards the elements of the 
 calcareous stone which forms the base of the 
 
MODE XIV. CALCAREOUS GLUTBNITE. 
 
 bricia, and which was deposited at the same time, 
 or alternately with them, have enclosed and kept 
 them in that position."* 
 
 The nagelfluh of the Swiss is a bricia, with a 
 calcareous cement; the fragments seem to be 
 commonly siliceous ; but Mr. Jameson says that a 
 kind, wholly calcareous, is found in Bavaria ; it is 
 incapable of polish. 
 
 It is singular that no bricia can be clearly and 
 positively assigned to the times of ancient art. 
 ferber informs us, that the Italians apply the 
 word bricia to any marble, which has spots that 
 are clear and distinct ; while it ought to be con- 
 fined to real bricias, consisting of fragments joined 
 by a calcareous cement. 
 
 The bricia which seems to have the best claim African bricia, 
 to antiquity, is that called the African, which, on 
 a black ground, presents large fragments of a 
 whitish grey, of a deep red, or of a dull purple. 
 Of this marble there is a large column in the 
 Napoleon museum; but the name of African 
 seems to have been bestowed merely on account of 
 its black ground ; for it is not mentioned by any 
 ancient author, and, if known to antiquity, was 
 probably Grecian ; perhaps the Chian, with spots 
 of many colours on a black ground. As the walls 
 
 841, 
 

 524 DOMAFN 1 V. CALCAREOUS. 
 
 of their city were built with this marble, the ques- 
 tion might perhaps still be settled by a learned 
 traveller. When they showed them in a boasting 
 manner to Cicero, his dry sarcasm, on their great 
 pride and small domain, was, " I should have ad- 
 mired them more, if they had been built of tra- 
 vertine." After all, this marble may perhaps be 
 Italian ; for Ferber informs us that the same kind 
 is still found at Seravezza, on the opposite side of 
 the mountain to Carrara, which is also called 
 Africano, and employed instead of the antique*. 
 The names, imposed by the ignorant and interest- 
 ed dealers and artists, deserve no credit ; and an 
 intelligent traveller must study the marbles in the 
 undoubted remains of antiquity, beginning with 
 those which continued in general estimation and 
 use for many centuries, as the Laconian, the 
 Phrygian, the Numidian, and the imperial or 
 Egyptian. 
 
 No other bricia appears in Ferber's catalogue of 
 Antique, the ancient marbles of Rome ; but some others 
 are styled antique, probably only on account of 
 their beauty. Such are the rose bricia, which, on 
 a base of bright red, is enriched with little spots, 
 rose and black, with larger ones of a beautiful 
 
 * Da Costa, p. 21 1, positively informs us that the black marble 
 vvith red and white spots, is Italian, though called African. 
 
 
MODE XIV. CALCAREOUS GLUTENITE. 
 
 white ; that called arlequzno, which on a pale yel- 
 low, presents many fragments of various colours, 
 resembling the beautiful bricia of Aix, but with 
 more splendour; the chocolate brown, with little 
 angular fragments of white ; and the white with 
 red fragments. What is called the grand antique, 
 is composed of large fragments of black in a white 
 cement*. The French apply the name, violet, to Violet. 
 a bricia, which, on a ground of pale brown, pre- 
 sents fragments of lilac and of white. One of the 
 violet bricias, described by Brard, is of a yellowish 
 green ; and presents white, green, violet, red, and 
 orange spots : but our author does not seem care- 
 fully to distinguish between Italian bricias, which 
 are often merely spotted, and the real bricias, 
 which are composed of fragments. 
 
 Among the bricias of modern Italy, may be Modem. 
 mentioned what the French also call violet-bricia, 
 being merely of a reddish brown, with white veins; 
 that of Brentonico with large yellow, grey, and Italy. 
 rose spots ; that of Bergamo, of black and grey in 
 a greenish cement ; and that of Alcamo, in Sicily, 
 of a bright grey with rose spots. The territories 
 of Verona and Trent yield a beautiful bricia of 
 pale red, crimson, and bluish fragments in a red 
 cement. Spain boasts the bricia of Riela, in Ar- Spain. 
 
 * Brard, 340. 
 
DOMAIN T. CALCAREOUS. 
 
 ragon, of a reddish yellow with fragments of 
 black ; and those of Valencia, of a pale yellow. 
 That of Old Castile is much employed at Paris, 
 being of a bright red, dotted with yellow and 
 black, and enclosing fragments of a pale yellow, 
 brick red, deep brown, and blackish grey*. They 
 are rather round, so that it might be called a 
 pudding-stone, if this division were natural; for 
 in the original and beautiful pudding-stone of 
 England, whose name has passed into all lan- 
 guages, the small pebbles are often angular, 
 which, with many other instances, shows the divi- 
 sion is unnecessary. 
 
 No bricia worth mention, seems hitherto to 
 have been discovered in the British dominions. 
 France. France presents a beautiful marble of this de- 
 scription, very common at Paris. The ground is, 
 in some pieces, of a pale brownish red, in others 
 of a straw colour ; and is itself chiefly composed 
 of very small fragments of the same colours with 
 the larger, which are of all shapes, and from half 
 an inch to two or three inches in size. These 
 spots are generally of a light brown, or straw 
 colour, and are interspersed with other fragments 
 of a slate blue and pale red, with others of a light 
 
 * The celebrated Irocatello, or cloth of gold of Catalonia, is by 
 some regarded as a bricia. 
 
MODE XIV. CALCAREOUS GLUTENITE. 527 
 
 grey and dull white : a striking singularity is, that 
 the large brown spots have sometimes red edges, 
 and an oval or triangular spot of light grey will 
 have a red spot of the same shape in the centre ; 
 so that the very fragments would seem to be of 
 original crystallisation, which has been modified, 
 or rather disturbed, by some violent cause, at a 
 particular period of its progress. This singular 
 marble might, with the English kollanite, form 
 a cabinet of study for the geologist; for the 
 appearance of both is utterly irreconcileable with 
 received opinions. As sand is now allowed to be 
 often a product of original crystallisation, so peb- 
 bles, which are only a larger sand, must in the 
 kollanite, and may in this calcareous rock, be of 
 original formation, and afterwards agglutinated 
 by a resumed progress of the process. 
 
 This singular bricia is at Paris called brlche 
 cVAleppe, as if it came from Aleppo in Syria ; but 
 M. Brongniart informs us that this is a corrup- 
 tion, and that it should be called d'Alet, from a 
 place about a league from Aix ; yet he describes 
 it as red, black, and grey, which must be quite a 
 different sort. Brard, who has treated the French 
 marbles with great care, says, that the bricia 
 sometimes called of Aleppo, and sometimes of 
 Alet, by the marble-cutters of Paris, is the antique 
 violet bricia, which has been already mentioned ; 
 
528 bOMAIN V. CALCAREOUS. 
 
 but none of his descriptions in the least correspond 
 with that under view* ; and it is with regret that 
 on this and many other occasions, the praise of 
 accuracy, though it ought to form the chief ambi- 
 tion of such a work, must be withheld. It is also 
 surprising that he did not learn, from Brongniart, 
 that the bricia of Aix, which he compares with 
 the Arleguino, must be the same with that of Alet 
 in the vicinity of that town. His description of 
 Of Aix. the bricia of Aix, in fact, corresponds with the 
 present, as presenting grey, brown, and red spots, 
 on a yellowish base. The same remark may ex- 
 tend to his bricia of Marseilles, which is reddish, 
 with white, grey, and brown fragments ; and which, 
 he adds, is much used and highly esteemed at 
 Paris ; where it is unaccountably called bricia of 
 Memphis. It is surprising that Saussure, who 
 has described Aix and its vicinity, has not indi- 
 cated this singular marble, which was so worthy 
 of his attention in every point of view. 
 Of Eygiiers. Another singular French marble is the pudding- 
 stone of Eygliers above Mont Dauphin, on the 
 right bank of the river Guyl. This is composed 
 * of pebbles chiefly white, grey, and yellow, joined 
 by a reddish cement, and receives the finest polish. 
 Beautiful tables of this marble may be seen at 
 
 * P. 341. 
 
MODE XIV. CALCAREOUS GLUTENITE. 529 
 
 Grenoble; and inspection must verify whether the 
 pebbles have been rounded by friction, or the 
 whole be an original rock of a particular crystal- 
 lisation. 
 
 Another marble, called a violet bricia by the 
 French, comes from Seix and other places in the 
 department of Arriege, which is particularly rich 
 in beautiful marbles. It is a coarse brown, spot- 
 ted with lilac and white. That of St. Romaine, in 
 the department of Cote d'Or, so styled from the 
 excellent wines of Burgundy, is of a brick red 
 with angular fragments of yellow. Doulers, in 
 the department of the North, presents a bricia of 
 many fragments, ash colour, white, and reddish. 
 That styled of the Pyrenees, is of a brownish red, 
 with black, grey, and red fragments, and has con- 
 siderable reputation. 
 
 Of the common kind, Saussure has observed 
 the following examples : 
 
 The mountain near Vevey is composed of coarse 
 pudding-stone, the rounded flints being united by 
 sand, and this sand by a calcareous gluten, which, 
 in the rents and intervals of the beds, assumes the 
 form of spar. 
 
 The pudding-stone of which Mount Rigi is 
 composed, consists chiefly of red clay pebbles, so 
 soft as to be affected by rain water, and united by 
 a calcareous gluten. 
 
 VOL. i. 2 M 
 
530 DOMAIN V. CALCAREOUS. 
 
 A pudding-stone of fragments of black horn- 
 stein in a gluten of clay, iron, and lime*. 
 
 The chief specimens have been already indi- 
 cated. 
 
 STRUCTURE II. SMALL GRAINED. 
 
 Calcareous sandstones are regarded as common. 
 That of Fontainebleau, which is commonly rec- 
 koned calcareous, does not, by Brongniart's ac- 
 count, always effervesce with the nitrous acid ; 
 but only that of two quarries, Bellecroix and Ne- 
 mours, in which the curious crystals are found. 
 The others afford siliceous sandstone. 
 
 The sandstones which present zones of different 
 colours, and dendritic delineations, seem to be 
 chiefly argillaceous, the clay cement being im- 
 pregnated with iron. Calcareous sandstone often 
 alternates with limestone, and is ascribed by many 
 Sites. to the same formation. It is the most common of 
 all the sandstones, and forms long chains of hills, 
 from Osnabruck down to Hessia, and along the 
 Rhine. It also constitutes the base of the Can- 
 ton of Berne, and rises into considerable moun- 
 tains in the south of France, particularly that of 
 Caume, on the north of Toulon, which consists 
 
 * 1099, i94i, 1*39. 
 
MODE XIV. CALCAREOUS GLUTENITE. 531 
 
 of alternate beds of limestone and calcareous 
 sandstone*. 
 
 According to Patrin, the sandstone of Fontaine- Of Fontaine- 
 
 bleau. 
 
 bleau is always a calcareous glutenite ; but when 
 he praises its utility at Paris, where it is employed 
 in paving the streets, he forgets that it wears out 
 in three years ; while granite might be had from 
 Cherbourg, which would last thirty. This cele- 
 brated sandstone sometimes forms regular beds, 
 and sometimes only appears in blocks, dispersed 
 in heaps of pure quartzy sand, upon which the 
 gluten does not seem to have acted. For Rom& 
 de Lisle has long since remarked, that such sand 
 is often a pure homogenous production of nature, 
 which must not be confounded with those pro- 
 ceeding from decomposition!. The formation of 
 this stone seems illustrated by the noted crystals, 
 which, though composed of quartzose sand, as- 
 sume the rhomboidal form of calcareous spar; 
 and some even present crystals of a beautiful yel- 
 low spar, quite transparent. Perhaps it was in a 
 different quarry, that Lassone made the singular 
 remark, that the new surface, at the end of some 
 
 * Patrin, iii. 324. He seems singular in his opinion that the 
 building stone used at Paris is a calcareous sandstone, while aJl 
 others regard it as a konite. See Brongniart, art. Moellon t i. 204. 
 It is the chaux carlonatte grossiere of Hauy. 
 
 f ii. 63. 
 
 2 M <2 
 
IJbMAIN V. CALCAREOUS. 
 
 months, was covered with a glassy crust of a sili- 
 ceous nature, arising from some lapideous juice, 
 which remains, as before observed, among the 
 secrets of nature ; because stones have never been 
 analysed in their original state. 
 
 Even Mr. Kirwan has little enlarged upon the 
 calcareous sandstones. Mr. Jameson has, as 
 usual, employed much labour in illustrating the 
 different formations ; but he has not drawn a pre- 
 cise line of distinction between the different kinds ; 
 as it is probable, however, that his third forma- 
 tion is chiefly a calcareous glutenite, the fallowing 
 curious observations well deserve a place here. 
 la columns. " No rock presents a greater variety of exter- 
 nal appearance than this sandstone. Its valleys 
 are deep, rocky, and romantic ; its hills conical, 
 steep, and cliffy ; and it often presents grand co- 
 lossal pillars and masses, which, from their num- 
 ber and variety of their shape, form most striking 
 rocky scenes. These hills, pillars, and masses, 
 often reach a considerable height ; but their sum- 
 mits are all nearly on the same level. One of the 
 most striking appearances of this kind is at Aders- 
 bach, in Bohemia. There we observe numberless 
 cones, pyramids, and pillars, sometimes isolated, 
 sometimes joined together, and from two to three 
 hundred feet high, spreading over a considerable 
 tract of country. In other places, caverns or 
 
MODE XIV. CALCAREOUS GLUTENITE. 533 
 
 grottos appear, from which there issue many 
 streams, that give rise to waterfalls, and thus in- 
 crease the beauty of this striking scene. These 
 caverns are wide at the mouth, but become very 
 narrow towards their further extremity, and are 
 generally very short. This form shows that they 
 owe their existence to external agents, particularly 
 water. A more near examination discovers that 
 the seams of the strata of the different isolated 
 masses correspond to each other ; which renders 
 it probable that all these cones, pyramids, and 
 pillars, have been formerly united; and that the 
 perpendicular rents or fissure^ have given rise to 
 this disunion, which has been afterwards increased 
 by the action of the air, and by the water carrying 
 away the softer or more loosely aggregated parts 
 of the sandstone, and leaving the harder parts in 
 these various forms. A similar appearance of 
 sandstone occurs near Tunis, and, from its striking 
 resemblance to ruins, is described as the remains 
 of a great city, by some travellers who saw it at a 
 distance. In the land of the Namaquas, in 
 southern Africa, and on the banks of the Wolga, 
 there are similar appearances."* This glutenite 
 may, however, be argillaceous. 
 
 * Geognosy, l6l. Soulavie, tome i. gives a print of square cal- 
 careous columns at Ruons, on the river Ardeche. 
 
DOMAIN V. CALCAREOUS. 
 
 In his edition of Linnaeus, Gmelin has produced 
 various minute substances, while he ought to have 
 begun this genus with his sixteenth species, as the 
 most important, being the Quadrum, celebrated as 
 he says in architecture*, The venerable Wal^ 
 lerius has with more judgement, as usual, de- 
 scribed the quadrum; so called, as he says, be- 
 cause it often rises in square forms. He esta- 
 blishes its calcareous nature ; and says that it is 
 of great use in architecture. He mentions the 
 white, the yellow, the grey, and the red, the latter 
 being from Shropshire. Pott, Vogel, and others, 
 at first supposed this stone to be merely cal- 
 careous, and even the sand may in fact be cal- 
 careous; but in general, upon leaving a small 
 fragment in the nitrous acid, the quartzy sand will 
 become visible or tangible. A useful observa^ 
 tion is, that the nearer to the sea it is quarried, 
 the less it will withstand the weather ; as any 
 saline particles attract the humidity, which during 
 frost expands and splits the stone. In like manner 
 if konite be accidentally moistened with sea-water, 
 }t will be subject to decay. 
 
 In the passage of Fours, near the mountain of 
 
 * He ranks it among the calcareous, though by his description it 
 must be argillaceous. The cement is, however, sometimes of marl, 
 or a mixture of lime and clay. 
 
MODE XIV. CALCAREOUS GLUTENITE. 535 
 
 Bonhomme, Saussure observed a remarkable sand- 
 stone, which he thus describes : 
 
 " All the beds of sandstone observed on this Of Fours, 
 mountain do not contain rolled pebbles; there 
 being irregular alternations of beds of pure sand- 
 stone, and beds mixed with pebbles. The most 
 elevated contain none. The highest of those 
 which contain any, is a continued bed of a foot in 
 thickness, and which rises 30 degrees to the 
 N. W. 
 
 " Some of these beds, filled with pebbles, pre- 
 sent a very remarkable singularity : on their ex- 
 ternal surface exposed to the air, is observed a 
 kind of network formed of black and saliant veins, 
 two or three inches above the surfa.ce of the rock ; 
 the meshes of this net are sometimes irregular; 
 but for the most part they are oblique-angled 
 quadrilaterals, whose sides are eight or ten inches 
 long. As these rocks have all a tendency to split 
 in rhomboids, it seems that there have been for- 
 merly clefts, which divided the beds in parts of 
 this form ; and that these clefts have been filled 
 by sand, which has been cemented by a fer- 
 ruginous juice : this solid gluten, has made these 
 parts harder than the rest of the rock; and when 
 the injuries of the air have attacked the surface of 
 these beds, the meshes of the net have remained 
 protuberant. 
 
536 DOMAIN V. CALCAREOUS, 
 
 " The rounded pebbles, which have been long 
 exposed to the air, have also outwardly assumed a 
 blackish ferruginous tint ; but those which are still 
 enclosed in the beds of sandstone have, like that, 
 a yellowish colour. I found none in it which 
 were not of a primitive nature ; and the most part 
 were of a very hard grey or reddish felspar, and 
 confusedly crystallised. They are then stones 
 which do not naturally possess a rounded form, 
 and which consequently only receive that they 
 have here, by rolling and the friction of the 
 waters. 
 
 " All these sandstones effervesce with acids 
 but the ferruginous parts of the net much less 
 than the base itself. In like manner, if the sand- 
 stones which contain pebbles, and those which do 
 not, are compared, in the former will be found 
 more calcareous gluten, their coherence being 
 much more diminished by acids. On the very 
 summit of the mountain these sandstones are co- 
 vered by a grey shining slate, which exfoliates in 
 the air ; and descending from this same summit, 
 on the N. E., on the opposite side to the passage 
 of Fours, beds of sandstone will be observed ex- 
 actly similar, and which there divide of themselves 
 in small parallelepiped fragments."* 
 
MODE XIV. CALCAREOUS GLUTENITE. 537 
 
 Saussure also gives numerous other examples of 
 calcareous sandstones. 
 
 Near Vaucluse, 1545, are beds of sandstone, OfVauciuse. 
 composed of angular and round fragments of 
 transparent white quartz, and of yellowish or 
 greenish steatite, semitransparent, in a calcareous 
 gluten. 
 
 A sandstone, 1564, of a red wine colour, in- 
 clining to violet, very fine, and spangled with cal- 
 careous spar. It makes a warm effervescence 
 with the nitrous acid, leaving a sand of white 
 quartz, and some grains of felspar. 
 
 A sandstone, 1487, composed of grains of 
 quartz, and a kind of red ochre, in a calcareous 
 cement. 
 
 The sandstone of Voisy, 304, consists of 
 quartzy sand, mingled with a little clay, and 
 small specks of mica, all united by a calcareous 
 gluten, which sometimes assumes the form of 
 spar in the interstices of the beds. 
 
 " I have seen myself," says this accurate f Recent 
 
 formation. 
 
 author, 305, " on the shores of the Mediter- 
 ranean, near Messina, and the noted Gulph of 
 Charybdis, sands which are moveable, when the 
 waves heap them on the shore ; but which, by 
 means of a calcareous juice which the sea infil- 
 trates at that spot, harden gradually, so as to serve 
 
DOMAIN V. CALCAREOUS. 
 
 for mill-stones. This fact is well known at 
 Messina ; and stones are incessantly taken from 
 the shore, without their being exhausted or the 
 spot being lowered. The waves throw fresii sand 
 intOithe vacancies; and, in a few years, this sand 
 becomes so agglutinated, that the stones of new 
 formation cannot be distinguished from the an- 
 cient." 
 
 - In 583, Saussure mentions rocks consisting of 
 alternate layers of limestone and calcareous sand- 
 stone, in the mountain of Buet. In the same 
 mountain there is a pudding-stone, composed of 
 fragments of grey and reddish quartz, reddish 
 felspar, and little yellow pyrites, united by a cal- 
 careous cement. 
 
 The molasse of Geneva is a sandstone with a 
 calcareous cement, and a mixture of clay ; it is 
 soft and impure. That of Lausanne is one of the 
 hardest and best : it is of a beautiful grey inclin- 
 ing to blue with a calcareous gluten. The moun- 
 tain of Voirons, two leagues from Geneva, chiefly 
 consists of calcareous sandstone*. 
 
 Calcareous sandstone, from Fontainebleau, 
 
 The same, from Livonia. 
 
 The same, from Gothland, Sweden. 
 
 * Sauss. 61, 1100, 273. 
 
MODE XIV. CALCAREOUS GLUTENITE. 
 
 The same, from Swisserland. 
 \ The same, with limestone, from the south of 
 France, and various countries. 
 
 The same, in red and white layers, from Nor- 
 way. 
 
 The same, of a brownish red with silvery mica, 
 from Metz. That city is chiefly built with this 
 stone. 
 
 639 
 
DOMAIN VI. 
 
 CARBONACEOUS. 
 
 CARBON. 
 
 Name, 
 
 THE name Carbon is not the most happy, 
 as it arises from charcoal, an artificial sub- 
 stance, while carbon is now well known to 
 be an original element, which exists in the 
 purest state in the diamond, and enters 
 into the composition of siderite, perhaps 
 
DOMAIN VI. CARBONACEOUS. 541 
 
 the most ancient of all the rocks. Char- 
 coal is now regarded as a mixture of car- 
 bon and hydrogen. By combustion it is carbonic acid, 
 converted into carbonic acid gas, formerly 
 called fixed air, or aerial acid; whence 
 some writers have used the epithet aerated 
 lime, barytes, &c. for what are now called 
 carbonates of lime, barytes, and the like. 
 The discovery of this new air by Dr. Black, 
 led to wonderful improvements and a total 
 renovation of chemistry, which in its pre- 
 sent form has been called pneumatic, from* 
 its spiritual foundations. It is indeed re- 
 markable, that the profoundest study, and 
 the most patient experiments, should con- 
 duct us from matter to spirit ; and thence 
 by a natural gradation of thought, to that 
 ineffable spirit, the Creator of the uni- 
 verse. 
 
 The carbonic acid gas, more briefly call- 
 ed carbonic acid, forms a constituent part 
 of the atmosphere, in the proportion of 
 about 1, in the ]00, while the remainder 
 consists of about 77 of nitrogen and 22 of 
 oxygen gas. Combined with the earths, it 
 
542 DOMAIN VI. CARBONACEOUS. 
 
 forms carbonates : and that widely extend- 
 ed substance called limestone, which is 
 often primeval, is a carbonate of lime. 
 
 Carbon itself not only appears in the 
 purest state in the diamond ; but forms 
 the preponderant part, sometimes even 90 
 in 100 of the substances now under view, 
 and which have therefore been called car- 
 bonaceous. They not only enter into the 
 composition of rocks, and some even of the 
 primitive, but form rocks themselves, as 
 coal has been found in masses of 80 or 90 
 feet in thickness. The trivial name of sea- 
 coal, arising from its importation at Lon- 
 don, might therefore well be exchanged for 
 that of rock-coal, as we say rock-salt. 
 Some might, perhaps, prefer the German 
 Bergarts. appellation of bergarts, implying sub- 
 stances of whatever kind which enter into 
 the composition of mountains ; or the 
 Geostromes. Greek geostromes, proposed by Patrin, to 
 denote the strata of the earth. But as the 
 conchitic beds of limestone, sometimes 
 more recent than coal itself, though often 
 itn thin strata, universally assume the name 
 
DOMAIN VI. CARBONACEOUS. 54S 
 
 of rocks, any refined discrimination would 
 appear unnecessary. It has already been 
 more than once observed that the division 
 of mineralogy into three quite distinct and 
 separate provinces, METALLOGY, LITHO- 
 LOGY, and TETRALOGY, would be of the 
 utmost importance to the progress, illustra- 
 tion, and utility of the science ; each of 
 them being amply sufficient for the life and 
 labours of one man ; and, in this case, the 
 subjects under view could not be allotted 
 to any other grand division. 
 
 
544 DOMAIN TI. CARBONACEOUS. 
 
 MODE I. GRAPHITE. 
 
 Characters. Texture, fine grained, but sometimes coarse, 
 schistose. 
 
 Hardness, cretic. Fracture scaly foliated, some- 
 times slaty and uneven, sometimes rather con- 
 choidal. Fragments amorphous, rather sharp. 
 
 Weight, carbonose. 
 
 Lustre, metallic. Opake. 
 
 Colour, somewhat leaden, which occasioned 
 the vulgar, but very improper, name of black 
 lead. 
 
 When pure, it usually contains about 90 parts 
 oxyd of carbon, with 10 of iron ; but the foreign 
 kinds are often contaminated with large mixtures 
 of argil and silex, which renders them unfit for 
 the usual purposes of writing and drawing. 
 Sites. The best is that found at Borrodale, in Cum- 
 
 berland ; a mine which has long supplied the 
 world with this valuable article ; but the French 
 have lately succeeded in the fabric of an arti- 
 ficial kind. Graphite has also been recently 
 detected in the southern parts of Scotland, with 
 a singular kind of coal, called columnar, because 
 it appears like little basaltic prisms, 
 
MODE I. GRAPHITE. 545 
 
 It is sometimes of a scaly appearance, which 
 Werner has arranged as a subdivision. 
 
 In the perusal of books of mineralogy, every 
 judicious reader must have remarked that, ac- 
 cording to the various dispositions of the authors, 
 they are fertile and satisfactory on some topics, 
 and barren on others : whence the great utility 
 of compilation, whose office, from the days of 
 Aristotle and the first dawn of science, has been 
 to collect, and arrange for the universal benefit, 
 facts and observations, which became more va- 
 luable from being concentrated. The prince of 
 the Roman poets compares this practice to that 
 of the bee, who prepares her elegant edifice and 
 useful honey from various flowers, some of which 
 only perfume the desert air. This work has, 
 therefore, without hesitation or apology, adopted 
 interesting descriptions from former writers, 
 whether domestic or foreign, but especially the 
 latter; for many excellent works are published 
 which will not bear complete translation, but of 
 which detached portions are highly satisfactory 
 and interesting. Such is the elementary treatise 
 on mineralogy by the ingenious Brongniart, di- 
 rector of the celebrated manufacture of porcelain 
 at Sevres, whose accounts of graphite and an- 
 thracite (which will follow in its proper place), 
 
 VOL. i. 2 N 
 
546 DOMAIN VI. CARBONACEOUS. 
 
 are the most ample and satisfactory which have 
 yet appeared. 
 Brongniart's " Graphite is of a grey almost black, with a 
 
 account. . . ' 
 
 metallic lustre; it is sort, smooth, and even unc- 
 tuous to the feel ; its fracture granular ; it leaves 
 distinct marks on paper, clear, and of a bluish 
 black ; it even leaves marks on vitreous surfaces, 
 such as earthen-ware : its marks are grey, while 
 those of sulphuretic molybdena, which much re- 
 sembles it, are greenish. 
 
 " Its specific gravity is from 2,08 to 2,26. It 
 consumes and volatilises under the blow-pipe, 
 by a continued heat. Nitre renders its combus- 
 tion quicker and more sensible. 
 
 " Slightly rubbed on resin, it does not com- 
 municate any electricity to it, while it leaves a 
 kind of metallic coat. 
 
 " This substance, according to the experi- 
 ments of Mess. Berthollet and Monge, is com- 
 posed of iron and carbon, in the proportion of 
 0,90 of carbon and 0,09 of iron. The iron is in 
 too small a quantity to rank graphite among the 
 iron ores. 
 
 " 1. Laminar Graphite. It is found in la- 
 mellae, or rhomboidal, or hexagonal spangles ; it 
 is of a tin- white. 
 
 " %. Granular Graphite. It is in mishaped 
 
MODE I. GRAPHITI. 54? 
 
 masses, or compact lumps, with a granular frac- 
 ture, the grains more or less fine. 
 
 " Graphite seems to belong exclusively to pri- 
 mitive regions : sometimes it enters into the com- 
 position of the rocks which form those regions; 
 sometimes it is found in masses, or in consider- 
 able layers. It is likewise met with in beds of 
 argillaceous schistus. 
 
 " It is found : in France, in the department 
 of Arriege, in large compact masses ; in the de- 
 partment of Mont Blanc ; in that of Sture, near 
 Vinay, above the baths ; in the mountain of 
 Lubacco, and in that of Gogni d'Orgial, in small 
 veins in granite. In the valley of Pellis, district 
 of Pignerol, department of the Po, in veins of a 
 yard in thickness, in granitic rock (Bonvoisin). 
 In Spain, near Sahun, district of Benabarra, in 
 the mountains of Arragon (Parraga), and near 
 Casalla and Ronda in the kingdom of Grenada. 
 In Bavaria : in Norway near Arindal ; this is the 
 laminar variety. In England, at Borrodale, two 
 miles from Keswick in Cumberland, this is the 
 most celebrated graphite mine ; pencils of an 
 excellent quality are made of it, and recommend- 
 able, as being at once firm and soft. The bed of 
 graphite is in a rather high mountain, between, 
 layers of a slaty schistus, crossed with veins of 
 
 2 N 2 
 
548 DOMAIN VI. CARBONACEOUS. 
 
 quartz; the bed or vein which it contains, is 
 nearly three yards thick ; the graphite is there 
 found in large masses, but of different degrees of 
 quality ; what is not good, is thrown away. 
 
 " Pencils, which are enclosed in cylinders of 
 wood, are made of graphite. In France they 
 are called mine de plomb, or capuchines. The 
 pieces of graphite are sawn in very thin quadran- 
 gular sticks, which are put in a groove made in 
 one of the halves of the wooden cylinder, which 
 is to form the envelope of this fragile pencil. 
 
 cc The dust of the graphite, mixed with gum, 
 forms pencils of an inferior quality. 
 
 " This same dust serves to lay over iron, and 
 especially cast iron, to keep them from rust; 
 mixed with grease, it is used very efficaciously 
 to diminish the frictions in wheel engines. 
 
 " Also, mixed with argil, at Passau in Ger- 
 many, they make crucibles of it, which resist 
 extremely well sudden transitions of temperature, 
 and which are used by smelters. 
 
 " Laminar graphite is often formed artificially 
 in the flaws of cast iron, and in the cavities of 
 furnaces where iron is used. M. Fabroni af- 
 firms that it is also sometimes formed in the 
 humid way; and cites, on this occasion, the pits 
 dug in the territory of Naples : an acidulous 
 
MODE I. GRAPHITE. 
 
 water is collected in them, at the bottom of 
 which, graphite is gathered every six months."* 
 
 Our ingenious author is mistaken, when he 
 says the graphite of Cumberland is found be- 
 tween layers of a kind of slate, traversed by veins 
 of quartz. Several specimens of the rock are 
 now before me. 
 
 1. Nodules of graphite in the rock itself; Graphite of 
 
 Borrodale. 
 
 which appears decomposed, and in some parts 
 tinged with oxyd of iron, arising from the par- 
 tial decomposition of the graphite. The stone 
 easily yields to the knife, and is of a bluish grey 
 colour mottled with white. It has an unctuous 
 steatitic appearance, and seems to be a decayed 
 serpentine. 
 
 2. The same rock, at a further distance from 
 the mineral, and undecomposed. This seems a 
 Saussurite, or magnesian basaltin. It is of a 
 deep grey colour with dots of light brown, which 
 may be a decomposed felspar; and is mixed 
 with large patches, which approach the nature 
 of indurated steatite, of a light greenish grey, 
 mottled like the decomposed substance which 
 contains the nodules. It is, upon the whole, a 
 magnesian rock, of a particular description, 
 with a stong argillaceous smell, in this and other 
 
 * Brongn. ii. 53. 
 
550 DOMAIN VI. CARBONACEOUS. 
 
 characters approaching to some serpentines; 
 for that peculiar odour does not arise from the 
 argil, as commonly supposed, but from the iron 
 contained in the argil, and therefore expires from 
 many rocks not argillaceous. It is worth obser- 
 vation, that serpentine has never been observed 
 to contain any metal except iron, and its rela- 
 tives pyrites and garnet ; so that it is not sur- 
 prising that it should contain graphite, or car- 
 buret of iron. Perhaps the superiority of the 
 English kind may be owing to this circumstance, 
 the unctuous nature of the rock imparting that 
 quality to the mineral ; as common flint becomes 
 menilite, from the unctuous and magnesian marl 
 in which it is deposited. 
 
 Another rock is found at Borrodale, I know 
 not if in contact with the former, but it appears 
 somewhat allied from the structure and nodules. 
 This seems to be a magnesian felsite, of a dark 
 grey colour, dotted with little reddish crystals, 
 and with greenish nodules. It is well known 
 that the British rocks are often anomalous, or 
 transilient, and can scarcely be reduced to pre- 
 cise denominations, till the science shall have 
 made a far greater progress than it has at 
 present. 
 
 of chamouni. Saussure discovered graphite, which, with the 
 writers of that time, he calls plombagine, on 
 
MODE I. GRAPHITE. 
 
 schistose quartz, among the Alpine fragments in 
 the valley of Chamouni -, but upon reaching the 
 rocks, it only formed a kind of gneiss, being thin 
 plates of graphite interposed between layers of 
 quartz, thus assuming as it were the place of 
 foliated mica. 
 
 STRUCTURE I. MASSIVE. 
 
 Aspect 1. Fine. From Borrodale, near Kes- 
 wick, in Cumberland. 
 
 The same, in nodules in the rock already de- 
 scribed. 
 
 The same, as found with columnar coal, from 
 Scotland. 
 
 The same, from the north of Italy, France, &c. 
 
 Aspect 2. Coarse. This is commonly mixed 
 with silex, argil, and other impurities. 
 
 From various parts of France and Germany. 
 
 STRUCTURE II. LAMINAR. 
 
 With laminar quartz, from the valley of Cha- 
 mouni. 
 
 From Arindal, in Norway. 
 
 Laminar graphite, interposed at certain inter- 
 vals in gneiss, from Greipon, in the Alps. Com- 
 municated by Gillet Laumont. 
 
552 
 
 DOMAIN VI. CARBONACEOUS. 
 
 MODE II. ANTHRACITE. 
 
 Character!. Texture, schistose and incoherent. 
 
 Hardness, cretic. Fracture, slaty. Frag- 
 ments, amorphous, rather sharp. 
 
 "Weight, carbonose. 
 
 Lustre, sometimes dull, but generally glisten- 
 ing and even metallic. Opake. 
 
 The colour is often a dark black, but some- 
 times has a metallic reflection, which is particu- 
 larly conspicuous in that elegant kind called 
 Kilkenny coal ^ and which might with much 
 Kirwanite. propriety be called Kirwanite, in honour of the 
 great Irish mineralogist, who first introduced it 
 to scientific attention. The French continue, 
 most unaccountably, to confound it with canel 
 coal, which is quite a different substance*. 
 
 Anthracite seems to have been first observed 
 by Dolomieu; but Born, in his elegant cata- 
 logue of Miss Raab's collection of minerals, has 
 classed it under graphite, which he calls plom- 
 lagine, or carburet of iron, in the following 
 
 * In order to obviate this error, the author, among many other 
 British substances, placed specimens of Kilkenny coal in the 
 museum of the Jardin des Plantes, and another great collection at 
 Paris. 
 
MODE II. ANTHRACITE. 553 
 
 terms. It must not at the same time be for- 
 gotten, that Pliny uses the word anthracites, in 
 a very different sense, for a gem which has the 
 effulgence of burning coal. 
 
 " Coaly Plombagine. Anthracolite. 
 
 cc This kind of plombagine has recently been Bom's 
 discovered at Schemniz, in Hungary, which dif- 
 fers from the known plombagine, as being very 
 light, compact, brittle, of a shining and con- 
 choidal fracture, and without soiling the fingers 
 is easily broken. It has but very little iron in 
 its mixture, and therefore when calcined under 
 a muffle, slowly dissipates, and loses 90 parts of 
 its weight. According to the analysis, lately 
 made at Schemniz, in Hungary, in 100 parts 
 there are 90 of carbon, 5 of argil, 3 of iron, and 
 2 of silex. 
 
 cc It seems to have some affinity with the in- 
 combustible pit-coal, described by M. de Mor- 
 veau in the new Memoirs of the Academy of 
 Dijon. Prem. Semest. 1783, page 7686. 
 
 " Mr. Struve has just given the description 
 and analysis of a fossil, which, with the excep- 
 tion of the colour, still more agrees with this 
 variety of plombagine. He calls it also coaly 
 plombagine. See Journal de Physique, 1790, 
 January, p. 55. 
 
 " Black compact coaly plombagine, with 
 
554 DOMAIN VI. CARBONACEOUS. 
 
 a shining fracture ; of Pacherstolln at Schemniz, 
 in Hungary. 
 
 " It adheres to a blue argil, greyish, mixed 
 with pyrites. The vein, in which it is found, is 
 filled with this argil, which is only a decomposi- 
 tion of the metalliferous rock. It is in this argil 
 that different sized pieces of this coaly plomba- 
 gine are found, which for the most part have a 
 cylindrical form. They even seem to be com- 
 posed of concentric layers round a kernel ; in 
 short, this plombagine nearly resembles wood, 
 and to all appearance has a vegetable origin." 
 
 Estner also agrees in the wood-like appear- 
 Of the Alps, ance of this anthracite. Among other rocks 
 presented to me by Gillet Laumont, are different 
 specimens of anthracite, which he says is also 
 called houille s^che, or dry coal. There is parti- 
 cularly a specimen of that mentioned by Dolo- 
 mieu, as belonging to primitive regions, and 
 containing no traces of vegetables, from little 
 St. Bernard, in going to the fort in the Alps. 
 This is accompanied by the following specimen 
 and note : " Vegetable impressions, which I first 
 discovered in 1803, serving as a roof to the same 
 anthracite, or dry coal, the wall or under-rock 
 being also a schistus. I had one very fine, with 
 little ramified plants, and another with reeds. 
 A little impression is on this specimen 5 but the 
 
 
 
MODE II. ANTHRACITE. 55,5 
 
 finest are in the cabinet of the Council of Mines." 
 Another specimen of anthracite is from Allues, 
 Mont Blanc ; and a third, which is slaty, is from 
 Regny, near St. Simphorien de Laie, on the road 
 fr n Roarme to Lyons. 
 
 The best account of anthracite, as already 
 mentioned, is that given by Brongniart, which 
 shall therefore be translated. 
 
 " Anthracite so much resembles coal, at first Brongniart's 
 
 . r . . r account. 
 
 sight, that for a long time it was taken for a 
 variety of that combustible mineral. Neverthe- 
 less, artisans who used it had remarked, that it 
 burnt with great difficulty, and did not produce 
 either that white flame, or black smoke, or 
 that bituminous odour which arises from coal; 
 therefore it was called, incombustible pit-coal. 
 
 " Anthracite is of a black less opake than 
 coal ; its colour approaches nearer by its bright- 
 ness, to the metallic black ; it is also more fri- 
 able ; it is rough to the touch, and easily stains 
 the fingers; it leaves a black mark on paper, 
 which, if examined with attention, seems of a 
 dull black. These characters serve to distin- 
 guish it from graphite, which leaves a bright 
 mark, and is unctuous to the feel. 
 
 " The texture of anthracite, sometimes schis- 
 tose, sometimes compact, at others granular, is 
 too various to serve as a characteristic. Its spe- 
 
556 DOMAIN VI. CARBONACEOUS. 
 
 cific gravity, which is 1,8, is inferior to that of 
 graphite, in the proportion of 9 to 14 ; and ex- 
 ceeds that of coal, as 9 to 7. 
 
 " This mineral is decidedly opake, it easily 
 allows the electric spark to pass, is hard to bum, 
 and in its combustion never produces but one 
 substance, which is carbonic acid. 
 
 " The matter essential to its composition, is 
 mixed carbon ; or perhaps combined sometimes 
 with silex and iron, sometimes with argil and 
 silex in very different proportions, according to 
 analysed specimens. 
 
 " 1 . Friable Anthracite. It is in mass, gra- 
 nular, not schistose, greatly soiling the fingers, 
 and easily crumbles. 
 
 " 2. Scaly Anthracite. It divides into large 
 solid scales, the surface of which is unequal, un- 
 dulated, and shining ; it soils the fingers less 
 than the preceding. 
 
 " These two varieties are found at the villages 
 of Arrache and Macot, in the neighbourhood of 
 Pesey, department of Mont Blanc. 
 
 " 3. Schistose Anthracite. (Haiiy.) It di- 
 vides into laminae, with an uneven and undulat^ 
 ing surface. 
 
 " 4. Globular Anthracite. (Haiiy.) It is 
 found in small globular masses, in crystallised 
 carbonate of lime, at Kongsberg in Norway, 
 
MODE II. ANTHRACITE. 557 
 
 " Anthracite is often found in primitive re- 
 gions, which is a remarkable circumstance in a 
 combustible which seems so nearly allied to coal. 
 It generally is found in mica-slate, and even 
 gneiss; it is sometimes in beds, sometimes in 
 veins. Its layers are often winding and con- 
 torted, like those of the rocks with which it 
 alternates. 
 
 c( Dolomieu saw anthracite in veins, in the 
 porphy ritic mountains near Chapelle, department 
 of Saone and Loire. In the Tarentaise of Savoy, 
 it contains 0,72 of carbon, 0,13 of silex, 0,03 
 of argil, 0,03 of iron, and 0,08 of water. Primi- 
 tive anthracite is found in Piedmont, at the foot 
 of little St. Bernard. In the department of 
 Isere, in lumps or heaps, in the midst of a pud- 
 ding-stone, composed of primitive rock, and 
 without any vestige of organised bodies. At 
 Musy, near Clayte, in the former Charolais. 
 At St. Simphorien de Laie, in the environs of 
 Roanne. At Diablerets, in Valais. 
 
 " M. Ramond has mentioned an interesting 
 variety, which he found at the bottom of the 
 valley of Heas, the upland of Troumose, depart- 
 ment of Upper Pyrenees, in the midst of mica- 
 slate. This anthracite disposed in veins, only 
 contains carbon, mixed with a small quantity of 
 silex and argil, there not being any iron. This 
 
558 DOMAIN VI. CARBONACEOUS. 
 
 circumstance fully distinguishes anthracite from 
 graphite. 
 
 " M. Fleuriau de Bellevue has found anthra- 
 cite crystallised in regular hexaedral plates, on 
 a granitoid, which is found in isolated blocks on 
 the quays of Saardam, in Holland*. It is 
 thought these rocks have been brought from 
 Norway. This anthracite, according to M. 
 Vauquelin, only contains carbon, silex, and 
 argil. 
 
 " Anthracite is also mentioned in the neigh- 
 bourhood of Schemnitz, in Hungary, in a vein. 
 At Kongsberg, in Norway, it is mingled with 
 native silver. In Spain, in the port of Pajares, 
 which separates the kingdom of Leon from the 
 principality of the Asturias, it reposes on a clay- 
 slate; and, according to M. Proust, contains 
 0,93 of carbon, and 0,07 of sand, argil, and iron. 
 It is used in painting, the same as lamp-black. 
 (D. B. Canga-Arguelles.) 
 
 " Anthracite is not exclusively found in pri- 
 mitive regions. M. Hericart-Thury has shown 
 that that which is found in the department of 
 
 * In the curious collection of rocks formed by the venerable 
 Besson, formerly director-general of the mines of France, the author 
 was surprised to find numerous specimens from Zealand ; and the 
 possessor has even adduced them as such in his printed works. 
 They were from ballast thrown on the quays of Zealand. The 
 quays of London furnish many curious rocks. 
 
MODE IR ANTHRACITE. 559 
 
 Isere, near Allemont, towards the summit of the 
 mountain of Challanches, at an elevation of 2563 
 yards, is secondary. It lies between two beds 
 of black schistus, covered with impressions of 
 vegetables; it contains no bituminous matter, 
 and has 0,97 of carbon, so that it is nearly pure 
 carbon. That of Rousses, opposite the same 
 mountain, and that of Venose, near the village 
 of Oysans in the same valley, are also of se- 
 condary formation. The anthracite of Lisch- 
 witz, near Gera in Saxony, is in layers of 
 clay-slate, covered with vegetable impressions. 
 (Roemer.) 
 
 " The anthracite which contains no indication 
 of vegetable coal, is wholly incombustible ; that 
 which contains any, may burn, if two- thirds of 
 charcoal be added to it. (Hericart-Thury.)"* 
 
 Brochant observes, that if anthracite be held 
 a long time on fire, moving it often, it consumes 
 slowly without any flame; but only encircled 
 with a little glory, or irradiation, like red iron 
 and diamond. During this operation it loses 
 about two-thirds of its weight, and the residue is 
 of a blackish grey, which announces that the 
 combustion is imperfect. 
 
 * Brongn. U. 5$. 
 
560 DOMAIN VI. CARBONACEOUS. 
 
 It is worthy of remark, that as anthracite 
 has been found in a primitive glutenite or pud- 
 ding-stone, so the usual gangart of diamonds, 
 both in Hindostan and Brazil, is a ferruginous 
 pudding-stone. The author has had the satis- 
 faction of seeing one of the Deccan in the gan- 
 gart, the pebbles being an unctuous quartz ap- 
 proaching to chalcedony, as in the singular 
 sandstone of Egypt ; but some seemed impreg- 
 nated with iron, so as to bear some appearance 
 of imperfect light brown jasper. A little frag- 
 ment seemed to be siderous slate. 
 
 Anthracite is by Mr. Kirwan called native 
 mineral carbon. He observes, that the kind 
 found at Lischwitz, in extensive strata, and that 
 of Strido in Tuscany, are among the most pure. 
 Kilkenny coal. He rightly classes the Kilkenny coal as an An- 
 thracite ; and, by his analysis, it must be one of 
 the purest, as it contains no less than 97 of car- 
 bon. But it seems of a different structure from 
 the anthracite found on the continent, having a 
 far more compact appearance, with a metallic 
 lustre at once more bright and steady ; nor is it 
 so brittle, nor so ready to stain the fingers. 
 What is called the culm of Wales by Mr. Kir- 
 wan, and which he regards as a variety of this 
 Swansea coal, species, is probably the Swansea coal, of which 
 
MODE II. ANTHRACITE. 
 
 some kinds have a singular and highly metallic 
 lustre, approaching even to some iron ores of 
 Elba. 
 
 STRUCTURE I. ANTHRACITE. 
 
 Aspect 1. Compact. From Alliers, Mont 
 Blanc. 
 
 From little St. Bernard, accompanied by fine 
 slate with vegetable impressions. 
 
 Aspect 2. Laminar. From Regny, near St. 
 Simphorien. Other sites of both kinds are above 
 mentioned ; that of Kongsberg, in Norway, mixed 
 with native silver, being among the most interest- 
 ing. 
 
 STRUCTURE II. KIRWANITE. 
 
 The chief differences of this structure have been 
 already mentioned. Mr. Kirwan observes, that 
 when fresh broken it frequently appears of a vio- 
 let colour. Its lustre he estimates at 4, or metal- 
 lic ; while that of anthracite is from 3 to 4 ap- 
 proaching metallic. The fracture is foliated, but 
 the course of the plates variously, confusedly di- 
 rected, as in some kinds of common coal. Its 
 fragments are often coated with whitish illinitions ; 
 
 VOL. i. 2 o 
 
562 DOMAIN VI. CARBONACEOUS. 
 
 it will not burn till wholly ignited, and then slowly 
 consumes without caking or emitting flame or 
 smoke. The ashes are reddish and few. 
 
 Our learned author unaccountably omits the 
 nature of the rock and gangart; nor does he re- 
 pair the deficiency in his geological essays. 
 
 Aspect 1. Kirwanitefrom Kilkenny. 
 The same, with the gangart and specimens of 
 the incumbent rocks. 
 
 Aspect 2. The Swansea kind also burns very 
 slow, without flame, and yields a strong and lasting 
 mass of heat, with a glowing colour. Swansea is 
 in the county of Glamorgan, South Wales, in a 
 more southern latitude than Kilkenny. 
 
 Kirwanite from Swansea. 
 
MODE III. COAL. 
 
 MODE III. COAL. 
 
 This useful substance, which may be said to sites, 
 form the gold mines of England, is not only par- 
 ticularly abundant in the British dominions, but 
 widely diffused over many parts of the world. 
 The Netherlands and France seem to follow 
 Great Britain in this mineral wealth ; but it also 
 appears in the north of Italy, and various parts 
 of Germany, as Silesia and Hessia*. It has been 
 used in the north of China from time immemo- 
 rial, and is not unknown in Japan. Its discovery 
 in Australasia would add little to the advantages 
 of a new country abounding in wood. Con- 
 cerning the coal of Africa, nothing seems to be 
 reported. In the territory of the United States 
 of America, coal is said to abound on both sides 
 of the James river, but particularly in Virginia, 
 and towards the Ohio. In the isle of Cape Bre- 
 ton there is an extensive bed of coal, which is 
 chiefly used for ballast. 
 
 Coal appears to have been anciently known, Ancient use. 
 
 * There is a mine of excellent coal in limestone, in the hill 
 of St. Gingoulph, near Geneva, pronounced, as Saussure observes, 
 324, St. Gingo, probably the source of a ludicrous oath in 
 England, because the first reformers were educated at Geneva. 
 
 2 O 2 
 
DOMAIN VI. CARBONACEOUS. 
 
 not only in China, but in other countries. So- 
 linus * evidently indicates the use of coal, when, 
 mentioning the medical waters at Bath, he says 
 they are dedicated to Minerva, " in whose temple 
 the perpetual fire does not leave embers, but 
 is changed into rocky lumps." This pretended 
 miracle was the natural progress of a coal fire, 
 caked into hard cinders, instead of the soft em- 
 bers of wood. The abundance of coal in the 
 neighbourhood of Bath also favours this suppo- 
 sition. Nay, Theophrastus mentions that the 
 smiths of Greece sometimes used a black stone 
 for their fires, which must have been coal f. In 
 England it seems to have been in common use in 
 the twelfth century ; but still more early in 
 Flanders. 
 
 Coal forms prodigious strata, generally rather 
 descending than rising ; but the hill of St. Gilles, 
 near Liege, may be said to be chiefly composed 
 of coal, of which there are not less than 50 or 
 60 strata. The deepest mines known, are said 
 to be those of the country of Namur, some of 
 
 * Cap. 25. 
 
 *f He says it was found in Liguria, as was amber, and also in 
 Elis j and he speaks of its use as common among the smiths. For 
 that of Liguria, see Mode iv. Gagas whence the name of jet, as 
 first found there, was near Chimera, probably a pseudovolcano, 
 arising from inflamed coal. 
 
MODE III. COAL. 565 
 
 which descend two thousand four hundred feet, 
 or about half a mile. The semidiameter of the 
 globe is about 3500 miles ; so that our know- 
 ledge, comparatively, would only extend to the 
 outward texture of the paper, of a common 
 globe three feet in diameter. 
 
 Mr. Kirwan has, with his usual accumulated Soils. 
 reading, discussed the various soils in which coal 
 appears; but an enumeration of the different 
 beds of clay and stone, would little interest the 
 general reader, while the scientific may consult 
 his work*. "The beds which immediately co- 
 ver coal, and are thence called its roof, are shale, 
 (a kind of clay-slate,) and argillaceous sand- 
 stone. Both contain impressions of vegetables, 
 generally such gigantic ferns and reeds as at pre- 
 sent astonish the traveller in the tropical regions. 
 The strata on which coal reposes, which are 
 thence called floor, sole, or pavement, are some- 
 times shale, or indurated clay; but more fre- 
 quently sandstone; and often the red ferrugi- 
 nous kind, which is esteemed most ancient. The 
 shells are chiefly those of rivers, and seldom those 
 of the sea. It is now well known, from the ex- 
 periments of Mr. Hatchet, that this substance is 
 of vegetable origin ; and it is a singularity, but 
 upon which no general theory can be con- 
 
 * Geol. Ess. p. 290. 
 
566 DOMAIN VI. CARBONACEOUS. 
 
 structed, that the chief beds of coal occur near 
 the mouths of great rivers, and in a kind of pro- 
 portion to their relative size. Thus the immense 
 Rhine, which seems, like many other powerful 
 streams, to have more than once altered its estu- 
 ary, has in its vicinity rocks of coal at least 80 
 feet in thickness; while more moderate strata 
 are found near the Rhone, the Clyde, the Forth, 
 the Tyne, the Severn. In some instances the 
 form of the coat district is that of an isosceles 
 triangle, the vertex being towards the sea. In 
 savage countries, darkened with immense fo- 
 rests, and where wood is only a superfluous 
 weed, the quantity of trees overturned by age, 
 tempests, and inundations, exceeds all imagina- 
 tion. On the Missouri, there is said to be a 
 bridge, not less than three miles in length, form- 
 ed by successive trunks of trees, which have been 
 stopped in their progress ; and the soil near its 
 mouth may be said to be formed of alternate 
 strata of timber and mud, which may probably 
 become coal and shale, for the use of nations to 
 be born, after a period of many thousand years, 
 and who, perhaps, may faintly trace in their 
 annals some memory of a celebrated ancient na- 
 tion called Britons. 
 
 But this is merely an excursion of theory, and 
 the origin of coal is far from being precisely 
 ascertained. It occurs in such places, and with 
 
MODE III. COAL. 
 
 such circumstances, as, like the other works of 
 nature, seem calculated to confound the faint 
 light and puny pride of human reason. 
 
 Patrin, with his usual ingenuity, enumerates Patrin's re- 
 some of the most striking features, which accom- 
 pany this important formation. 
 
 (f Many similar circumstances every where 
 accompany beds of coal. 
 
 " 1. It is known that this deposit must have 
 been made in still water, and that it has been found 
 on the sides of the soil which has served it for 
 base. In general, beds of coal have their extre* 
 mities even with the ground, they descend ob- 
 liquely ; they assume in their depth nearly a 
 horizontal position, afterwards to ascend on the 
 opposite side ; so that by taking away, in idea, 
 all the soil which covers them, they will be found 
 to have nearly the form of a boat : it has been 
 remarked also, that they are thicker at their 
 depth than at their ends. 
 
 " This disposition is manifest in a great num- 
 ber of mines, and especially in the vast coal 
 mines in the neighbourhood of Liege. 
 
 " 2. A bed of coal is never single : at White- 
 haven in England there are 20, one above an- 
 other; at Liege there are reckoned 60 *$ three 
 
 * At Gilmerton, near Edinburgh, there is the same number. 
 Williams, i. 41. 
 
558 DOMAIN VI. CARBONACEOUS. 
 
 or four are most commonly found, and in general 
 of nearly an equal thickness. 
 
 " 5. Each bed of coal is separated from the 
 others by several rocky strata, which are nearly 
 the same in all coal mines. 
 
 " Those which form the roof and the wall, 
 are always of a schistose argillaceous substance, 
 a kind of friable schistus, almost always sulphure- 
 ous : afterwards follow strata of micaceous sand- 
 stone, which seem derived, at least in part, from 
 the detritus of the primitive mountains of the 
 neighbourhood. 
 
 " These strata of sandstone are often separated 
 by small schistose layers, which contain some 
 symptoms of coal ; they are both often repeated 
 between two beds of coal. 
 
 " It is a general observation, and almost with- 
 out exception, that the schistose layers, and 
 especially those which serve as a roof to the 
 coal, bear impressions of vegetables, particularly 
 capillaria, ferns and reeds, for the most part ex- 
 otic. This circumstance has led several natural- 
 ists to think, that coal itself is composed of the 
 remains of vegetables ; but this opinion appears 
 to me to present great difficulties *."f 
 
 * " One of the facts, which is most opposite to it, is the obser- 
 vation made at Santa-Fe-de-Bogota, by the naturalist le Blond, who 
 
 f Patrin, Min, v. 317. 
 
MODE III. COAL. 5() 
 
 Some select observations concerning coal may 
 be added from various authors. 
 
 By Mr. Kirwan's experiments coal commonly 
 consists of about 60 carbon and 40 bitumen*. 
 
 Though coal has never been found crystallised, structure, 
 it seems to split into regular cubes; and another 
 singularity in its structure has recently been ob- 
 served, that between the layers of a bright bitu- 
 minous appearance there are thin plates of a 
 velvety lustre, bearing a strict resemblance to 
 charcoal. Coal sometimes contains in little ca- 
 vities, crystals of calcareous spar, perhaps infil- 
 trated from incumbent limestone. These crys- 
 tals, towards their summits, present little black 
 zones, arising from the coaly impregnation. Ga- M 5 
 lena, or sulphate of lead, is also found in the coal 
 of Buckinghamshire. Pyrites are common in 
 most kinds of coal ; and, perhaps, the beautiful 
 iridescent illinitions, which in some rare in- 
 
 informs us that beds of coal are there found at an elevation of 13,200 
 feet perpendicular. When the ocean reached such a height, there 
 would be above its level but a small number of islands scattered 
 over the face of the globe ; and it is not any how seen, how the 
 small quantity of vegetables, which had been accidentally brought 
 from these summits of mountains, into this immense ocean, could 
 have formed the thinnest bed of coal, or even of simple turf." Is not 
 this coal of Santa-Fe anthracite ? 
 
 * Bitumen long retains its properties. That found on the bricks 
 of Babylon, where it was used as a mortar or cement, still burns, as 
 Mr. Parkinson observed, with a strong bituminous scent. 
 
570 DOMAIN VI. CARBONACEOUS. 
 
 stances equal all the colours of the richest gems, 
 may arise from the iron and sulphur, as they 
 greatly resemble those of the beautiful ores of 
 Elba. 
 
 Oxyd of copper has also been found in coal 
 at Schemnitz in Saxony ; cinnabar in that of 
 Jdria; native silver in that of Hessia; nay, gold 
 decorates the coal of Reichenstein in Silesia. It 
 is also said that antimony is found in that of the 
 isle called Bras d'or, near Cape Breton in Ame- 
 rica*. 
 
 Werner's ar Werner has arranged one species of coal un- 
 rangement. ^ er fa s g enus graphite, namely the glance coal ; 
 which he again subdivides into the conchoidal 
 and the slaty. Glance, applied in the German 
 sense to some ores* and a kind of coal, implies 
 that they have a peculiar bright lustre j and his 
 glance coal with the colour of tempered steel, or 
 a bright variable blue, and which burns without 
 flame or smell, is the same with that found at 
 Swansea, here arranged as a structure of anthra- 
 cite; for it has neither the appearance nor chemi- 
 cal character of graphite. The slaty glance coal 
 of Werner, the kohlenblend, or coalbletid of other 
 German mineralogists, is the anthracite. To such 
 inconsistencies have the forced and unnatural 
 
 * Brongniart, ii. 10. 
 
MODE III. COAL. 571 
 
 application of genus and species, to inert mat- 
 ter, reduced even the ablest authors. 
 
 Of common coal, Werner numbers two spe- 
 cies, the black, and the brown. 
 
 The black coal contains six subspecies; 1. Black coal. 
 Pitch coal ; <2. Columnar coal ; 3. Slaty coal ; 
 4. Cannel coal ; 5. Foliated coal ; and 6. Coarse 
 coal. The first is jet which belongs to lithology ; 
 the second which burns without flame or smell, 
 is an anthracite, as Voigt allows, and is merely 
 a rare variety. But from the want of judgement 
 in distinguishing between the grand and import- 
 ant substances, and those which are merely tri- 
 fling and rare varieties, sometimes only excep- 
 tions or excrescences, the very arrangement of 
 mineralogic systems is often the source of unne- 
 cessary embarrassment; the separation of the 
 pretended species being sometimes radical and 
 essential, and often of the most trifling and am- 
 biguous nature ; nay, sometimes as ridiculous as 
 if the species of trees were to be estimated by the 
 mosses which grow upon them, the fantastic forms 
 occasioned by accident, or the cavities hollowed 
 by the hand of time. 
 
 The third subspecies, which in this barbarous 
 system follows jet, a rare and precious substance, 
 and columnar coal which is confined to one 
 hill, the Meissner in Hessia, is that called slate 
 
572 DOMAIN VI. CARBONACEOUS. 
 
 coal y which is that substance universally known 
 by the sole name of COAL, which is diffused in 
 vast exuberance through half the globe, and 
 supplies nations with necessary fuel and opulent 
 manufactures ! This instance of want of judge- 
 ment may be added to numerous others already 
 observed by Mr. Chenevix *. 
 
 The fourth subspecies of Werner is cannel coal, 
 so called from the enunciation of the word candle, 
 in Scotland and the north of England, because 
 its flame is clear and pure, like that of a candle. 
 By many French writers, and even by Brochant 
 and Brongniart, it has been strangely confounded 
 with Kilkenny coal, which being an anthracite 
 emits no flame ; a clear distinction, indicated by 
 the simplest chemistry of nature. It is not only 
 found in several coal mines of the north of En- 
 gland, but in those of Gilmerton near Edinburgh. 
 When very pure, it is made into various little 
 vessels, snuff- boxes, and ink-holders. The Ro- 
 man writers mention jet, as a chief mineral pro- 
 duct of Britain, and some suppose that the can- 
 nel coal is intended, but it would rather appear 
 to be the real jet found on the eastern coasts, 
 particularly that of Norfolk, and which, as the 
 substance is merely bituminous wood, may either 
 
 * See his Critique on the Wernerian system, in the Annettes d? 
 CMmie, 180Q. 
 
MODE III. COAL. 573 
 
 proceed from parts of the submarine forest, re- 
 cently observed on the coast of Lincolnshire : 
 or, as it is very light, may be brought by the 
 sea from a great distance. 
 
 The fifth subspecies, Defoliated or laminar, is 
 found in the Electorate of Saxony, and in Sile- 
 sia; but it may certainly be observed in almost 
 every coal pit, as in fact almost all coal may be 
 said to be slaty ; nay, Werner has arranged it 
 himself under that subdivision. The last, and 
 very important subspecies, is coarse coal, which, 
 forsooth, has been found in the coal works near 
 Dresden ! It is too well known to many of my 
 readers, and rather too abundant on the London 
 wharfs. By such sagacious subdivisions, an im- 
 pure gold must be regarded as a different metal. 
 
 It may, perhaps, be satisfactory to complete 
 this brief view of Werner's coal, which, like the 
 magical mirror of Dr. Dee, formed of cannel 
 coal, represents spirits and species of all kinds 
 and dimensions, with some account of his other 
 division, that of brown coal, which contains five Brown coal. 
 subspecies. 1. Bituminous wood; 2. Earth coal; 
 3. Alum earth; 4. Common brown coal; and 
 5. Moor coal. 
 
 The first is an important and widely diffused 
 substance which may be said to form rocks, or 
 
574 DOMAIN VI. CARBONACEOUS. 
 
 rather mountain masses, by the Germans called 
 Bergarts i for as rocks may be formed of shells 
 and other animal substances, so they may be 
 constituted of the venerable remains of primeval 
 vegetation. This kind is the Bovey coal of En- 
 gland ; and in the Prussian amber mines is found 
 with adhering amber. It is the Surturbrand 
 of Iceland where it abounds ; and is diffused 
 through many parts of Germany, France, 
 Russia, Siberia, and other grand regions of the 
 world. 
 
 The second subspecies, earth coal, is sometimes 
 found with the former, being merely bituminous 
 wood more decomposed. The third, or alum 
 earth is certainly a most capricious alteration, 
 as he had formerly and properly arranged it 
 among the argils, and it ought in lithology to 
 stand at the very head of that class. It may 
 have been used as a fuel, as orsten is in Ireland; 
 and, perhaps, Mr. Werner may, in his annual 
 almanack of classification, arrange that lime- 
 stone among the coals. The fourth subspecies, 
 common brown coal, is, by Mr. Jameson's own 
 account, the same with the first or bituminous 
 wood, being found at Bovey, and in Prussia, 
 with amber; so that it can hardly be called a 
 variety, certainly not a diversity. The t y?/?A, or 
 
MODE III. COAL. ,575 
 
 last subspecies y that of Moor coal, is again a mere 
 variety of bituminous wood, but more brittle, as 
 it is mingled with reeds. 
 
 The author must confess, that when he had 
 perused Werner's account of the coals, his ideas 
 of the subject were far more confused than ever 
 they were before ; so that he seemed with great 
 study to have learned ignorance. This effect must 
 necessarily arise, when subjects of the utmost 
 importance, and of the most trifling minuteness, 
 are presented to the mental eye, as of equal mag- 
 nitude. By the unhappy microscope of external 
 characters, an insect may appear like an ele- 
 phant; while common sense and chemistry can 
 alone present the objects as they really are. It 
 is the chief, if not the only, use of systems in 
 natural history, to assist the memory ; and for 
 this purpose, that the faculty may not be strained 
 and overpowered, it is the office of a judicious 
 arrangement, to present the chief objects in the 
 fore-ground, while the others are marked at gra- 
 dual distances, that the mental eye may repose, 
 as upon a landscape, painted by a master artist. 
 
 But to return to a more immediate view of the 
 subject. It is not a little remarkable that dif- 
 ferent qualities of coal are found in different 
 strata of dissimilar rocks, thus confirming an 
 observation already made, that the quality of 
 
576 DOMAIN VI. CARBONACEOUS. 
 
 mineral substances is often influenced by their 
 gangarts. Mr. Kirwan has observed, and lie 
 has illustrated the observation by many ex- 
 amples, that the soils containing coal are chiefly 
 clay and sandstone, often both together; which 
 are followed*by the rarer instances of coal found 
 tinder trap or basaltin, which may also assume 
 the form of amygdalite; or, by the coarseness of 
 the particles, become a basalton or grunstein. 
 Thick beds of coal have also been found amid 
 the strata of limestone. As the theme is of great 
 importance to national and individual wealth 
 and prosperity, it may be proper to subjoin the 
 brief general view by Brongniart. 
 
 " The coal regions follow in general the same 
 order of composition. L Psammites (micaceous 
 and ferruginous sandstone, with a cement gene- 
 rally of argil,) often large grained: they are not 
 only composed of quartz and mica, but of frag- 
 ments of all kinds of rocks, particularly of fel- 
 spar. 2. Argillaceous and micaceous schisti > 
 presenting on their plates impressions of fishes 
 and vegetables, which generally belong to the 
 families of ferns and grasses. 3. Beds of marl, 
 carbonated lime, or indurated clay. 4. A kind 
 of secondary argillaceous porphyry, which con- 
 tains branches, roots, and even entire petrified 
 trees. 5. Argillaceous iron ore. 6. Rolled 
 
MODE III. COAL. 577 
 
 pebbles enveloped in ferruginous sand." * He 
 afterwards observes, that the limestone which 
 contains coal, often becomes black from inhala- 
 tions of the bitumen, while the inherent shells 
 are of a white colour. 
 
 A remarkable circumstance in coal mines is sups or dykes, 
 the frequent occurrence of what our miners call 
 slips or dykes, while the French call them crelns 
 or failles, consisting of indurated clay, basaltin, 
 called whin in Scotland, and sometimes of sand- 
 stone. These are sometimes of great extent, and 
 a whin-dyke is said to pass across the estuary of 
 the Forth, from East Lothian to Fife, a distance 
 of 10 or 12 miles. These slips intersect the 
 strata of coal, almost at right angles; and ge-- 
 nerally derange them, in regard to elevation, the 
 stratum of coal being higher and lower on the 
 different sides of this interruption. It seems a 
 general observation that the strata always sink, 
 on what may be called the back of the slip, 
 which seems to indicate that the matter was 
 ejected from beneath, and that the consequent 
 cavity had occasioned the subsidence on that 
 side. These slips sometimes contain fragments 
 of coal f. They appear in the section of the 
 
 4 
 
 Min. ii. 6. 
 
 f Near the slips the quality of the coal changes ; it sometimes 
 becomes iridescent j still nearer it splits and is friable 5 then be- 
 
 YOL. I. 2 P 
 
578 
 
 DOMAIN VI, CARBONACEOUS. 
 
 noted hill of St. Gilles, near Liege. Gennete 
 has inferred that there are in this hill not less 
 than 61 beds of coal which are salient, or in the 
 mining language rise to the day, at distinct dis- 
 tances, but only 23 are worked. The coal 
 mines of Anzin, near Valenciennes, described 
 by Daubuisson, present singular large zigzags 
 which seem to defy all theory, except the prodi- 
 gious power of steam, arising from internal fires 
 and waters, and acting while the beds were yet 
 soft. 
 Coal mines of The limits and nature of this work do not per- 
 
 England. 
 
 mit a description of the important coal mines, 
 even of England. Those of Newcastle are the 
 most celebrated, as they have supplied the capi- 
 tal for many ages. The land which covers these 
 mineral treasures, is often fertile, and lies on an 
 argillaceous sandstone, which forms excellent 
 grindstones, not only common in England, but 
 exported to other countries. Even the roads are 
 grand monuments of human industry, the tra- 
 veller being astonished to see large carts loaded 
 with coal, proceeding without horses or guides, 
 on wheels adapted to wooden ways defended 
 with iron. The coal mines of Whitehaven, on 
 the western coast, are the more remarkable, as 
 
 comes dull, earthy, and, as it were, identified with the slip. J. de* 
 Mines, No. 13, p, $9. 
 
MODE III. COAL. 
 
 they are continued for a space of more than 1200 
 yards, or two thirds of a mile under the sea ; a 
 situation like that of a mine in Cornwall, where 
 the raging waves are heard over head, most ter- 
 rible to the imagination. The most celebrated 
 coal mines of France are those of St. Etienne, in 
 the department of the Loire, which have been 
 worked for many centuries. Those of Flanders 
 are also of ancient reputation: and, perhaps, 
 our attention to this valuable substance was, 
 like many other useful improvements, derived 
 from our commerce with the Flemings *. 
 
 Even in the same bed the coal is seldom of the 
 same quality, or homogenous ; so that many of 
 the German subdivisions would, in the case of 
 any other substance, be regarded as mere varie- 
 ties. Such is the fibrous coal of Estner, which 
 was brought from Newcastle -, the ribbon coal 
 oflrvin on the western coast of Scotland ; the 
 parrot coal, said by some to be so called from its 
 iridescence, while others suppose that it received 
 its name from the crackling noise it makes when 
 first kindled. It is surprising that Werner has 
 not arranged the earthy coal, called smut or 
 culm, as a distinct subspecies. It has been ob- 
 
 * According to Buffon, Min. i. 478, 4to. the deepest coal mines 
 are those of Namur, 2,400 feet. 
 
 '2 P 2 
 
580 DOMAIN VI. CARBONACEOUS. 
 
 served, that where the coal approaches the slip, 
 it has lost its bitumen, whence it is argued, that 
 the slip rose heated from beneath ; while others 
 only infer, that the bitumen has been absorbed 
 by the humid rock. In confirmation of the for- 
 mer opinion, it is added, that in the north of 
 Ireland the layers of flint become red and light 
 when they approach the whindyke; and speci- 
 mens which I have seen, certainly bore every 
 mark of having been affected by great heat, 
 iridescent. The iridescence of coal often penetrates a large 
 mass, and appears in almost every direction. In 
 the peacock coal of Wales or Somersetshire, this 
 iridescence often assumes a strong resemblance 
 of what are called the eyes in a peacock's tail*. 
 In that of the valley of Llangolen, the iridescence 
 consists of steel-purple, crimson, green, yellow^ 
 and blue, disposed in zones. But by far the 
 most beautiful of this kind, is a coal found in 
 small portions, near Valenciennes, in which 
 crimson, green, blue, and yellow, perfectly opa- 
 lise or interchange; so that the substance has 
 more splendour than even the noble opal. The 
 exquisite vivacity of the tints can only be equal- 
 led by some of the celebrated iron ores of Elba; 
 
 * Mr. Parkinson, Org. Rem. vol. i., informs us that peacock 
 coal is found in Somersetshire at a considerable depth, the surface 
 being mingled with fossil shells, and vestiges of fern. 
 
MODE III. COAL. 53 1 
 
 and probably, on a chemical analysis, these 
 kinds of coal would be found to yield a small 
 portion of iron and sulphur. 
 
 The structure of coal, as already mentioned, 
 may be regarded as universally schistose: and it 
 is believed that even the columnar may be con- 
 sidered on a large scale, in the same point of 
 view, that is, the columns are horizontal, and 
 piled like billets of wood on each other. The 
 small columnar kind found in Scotland, consists 
 of little columns, about half an inch in diame- 
 ter, and a few inches in length, united in a com- 
 mon base *. Its form seems to arise from the 
 ferruginous gangart, which envelopes, as in a 
 sheath, the little columns of coal; and it is like- 
 wise said to occur in a form merely schistose. 
 It is in fact so minute as rather to belong to li- 
 thology. The chief variations of coal can there- 
 fore only be classed as aspects. 
 
 Aspect 1. Common coal. This substance is 
 only observable when it presents some remarkable 
 diversities, is accompanied with singular accidents, 
 or is brought from new regions. 
 
 * Mr. Jameson, Dumf. 1(50, says it is found about four miles 
 from New Cumnock, Ayrshire, along with graphite, which is also 
 sometimes columnar. 
 
582 DOMAIN VI. CARBONACEOUS. 
 
 Coal from Australasia. 
 The same from China. 
 The same from Cape Breton. 
 Ribbon coal, from Irvine, Scotland. 
 Peacock coal, from Wales, or Somersetshire. 
 Opaline coal, from Valenciennes. 
 Coal with calcareous spar, from Derbyshire. 
 With lead, from Buckinghamshire. 
 With foliated pyrites, and white veins of calca- 
 reous spar, from Derbyshire, &c. 
 With antimony, from North America. 
 With cinnabar, from Idria. 
 With copper ore, from Saxony. 
 With native silver, from Hessia. 
 
 With gold, from Silesia. 
 
 t 
 
 Aspect 2. Laminar or Foliated. 
 From Saxony and Silesia. 
 From the mines of Wodensbury, or Winsbury, 
 in Staffordshire. It is commonly of inferior quality. 
 
 Aspect 3. Cannel coal. This occurs in more 
 thick and compact layers, and the fracture is some- 
 times even, sometimes large and flat conchoidal. 
 
 Cannel coal, from Lancashire and Shropshire. 
 
 The same, from Gilmerton and Muirkirk, in 
 Scotland. 
 
MODE IV. LIGNITE. 
 
 Aspect 4. Columnar coal. 
 
 As the German kind belongs to anthracite, so 
 it is probable that the Scotish is of the same de- 
 scription ; the latter, however, presents the velvety 
 appearance of the charcoal plates in common coal ; 
 but is so deeply impregnated with oxyd of iron, 
 that it is partly of a brown, partly of a metallic 
 lustre ; which may not only be the cause that it 
 does not flame, but is probably the original source 
 of its columnar form, which iron often affects ; and 
 as the power and predominance of that metal are 
 very great, it often manifests its presence, by in- 
 ducing almost any other substance to assume its 
 tendencies. 
 
 MODE IV. LIGNITE. 
 
 This name has been assigned, with great pro- Name, 
 priety, by Brongniart to the substance which 
 Werner has called brown coal, with his usual at- 
 tachment to colours, which of all denominations 
 are the most vague and illusory. Some who 
 prefer Greek etymons might call it xylite, de- 
 rived, in like manner, from wood; but the Latin 
 language is equally classical with the Greek, and 
 
DOMAIN VI. CARBONACEOUS. 
 
 is of general use in the definitions of natural his- 
 tory ; so that there seems no reason for its ex- 
 clusion, while on the contrary its admission af- 
 fords a pleasing variety. 
 
 The account of lignite, given by Brongniart, 
 is so complete, clear, and satisfactory, that it 
 shall be translated with a few subjoined observa- 
 tions ; after premising that one of his varieties, 
 namely jet, rather belongs to lithology in every 
 sense, as it is found in small pieces, and only ap- 
 plied to minute purposes of use or decoration. 
 
 The others are found in large beds or masses, 
 by the Germans called bergarts ; and though 
 many rocks are composed of shells, corals, ma- 
 drepores, and other animal remains, the reader 
 might be startled at the idea of a rock composed 
 of wood. Yet rock-salt, which will be treated 
 among the Anomalous, perhaps affords an idea 
 little less incongruous ; and too great precision 
 would lead to neology, which ought always to 
 be avoided, except in cases of indispensable ne- 
 cessity. Rocks of pumice or of obsidian, or even 
 of topaz, are ideas equally new to the generality 
 of readers, yet they exist in nature, which must 
 be followed, and not controlled. 
 
 " The combustible minerals which belong to 
 this species, are characterised by the odour, and 
 the products of their combustion. The odour 
 
MODE IV. LIGNITE. 585 
 
 they spread in burning, is pungent, often fetid, 
 and has no analogy with that of coal or bitu- 
 mens. They burn with a clear flame, without 
 bubbling or caking like coal, or running like so- 
 lid bitumens. They leave powdery ashes like 
 those of wood, but often in greater quantity, 
 more ferruginous, and more earthy : they seem 
 to contain a little potash *. These combusti- 
 bles give an acid by distillation, which coal does 
 not. 
 
 " Lignites vary in colour from deep and 
 shining black, to an earthy brown : the texture 
 of the greater part of the varieties indicates their 
 origin, and gives rise to their name. The woody 
 tissue is often observed, though sometimes it has 
 wholly disappeared. The fracture of lignite is 
 compact, often resiniform and conchoidal, or 
 shining and straight. 
 
 " The external characters of the varieties of 
 the species differ too much among themselves, 
 to allow them to be farther generalised. 
 
 " 1. Lignite jet ^. It is hard, solid, compact, 
 and capable of receiving a very bright polish ; 
 it is opake and of a pure black ; its fracture is 
 undulated, and sometimes shining like that of 
 
 " * M. Mojon found about 3 in 100 in the ashes of the bitu- 
 minous wood of Castelnuovo. 
 
 " f J et > Hau}' Peckkohle, piciform coaL Brock." 
 
DOMAIN VI. CARBONACEOUS. 
 
 pitch. Its specific gravity is 1,259. It is said 
 to be sometimes lighter than water*. 
 
 " This variety is found in layers of little thick- 
 ness, in marly, schistose, calcareous, or sandy 
 beds. The organic tissue of wood is sometimes 
 observed in it. 
 
 " This lignite is found in France; in Pro- 
 vence; at Belestat, in the Pyrenees; in the de- 
 partment of the Audef, near the village of Bains, 
 six leagues to the south of Carcassone ; this 
 sometimes contains amber; and near Quilian, 
 in the same department, in the communes of 
 Ste. Colombe, Peyrat and Bastide ; it is at the 
 depth of 10 or 12 yards, in oblique layers, be- 
 tween beds of sandstone; but these layers are 
 neither pure nor continuous. Jet, proper to be 
 worked, is found in masses, the weight of which 
 seldom exceeds 50 pounds. These mines have 
 been wrought for a long time, and have pro- 
 duced a considerable quantity of jet, which is 
 cut and polished in the same country. 
 
 cc In Germany, near Wittemberg in Saxony ; 
 it is also there wrought and polished. Very 
 fine jet has been found in Spain, in Galicia, and 
 
 " * I doubt if real jet be ever lighter than water. This property 
 seems rather to belong to the next variety." 
 
 f An account of the manufacture of jet, in the department of the 
 Aude, may be found in the Jour, des Mines, No. 4, p. 35. P- 
 
MODE IV. LIGNITE. 
 
 in the Asturias. In short, it is mentioned as oc- 
 curring in Iceland, in the western part of that 
 isle. 
 
 " Of this combustible, ornaments are made, 
 particularly mourning trinkets. Jet is polished 
 with water, on a wheel of sandstone, worked ho- 
 rizontally. Jet, mingled with pyrites, is generally 
 rejected. 
 
 " 2. Friable lignite*. This variety is found 
 in extensive and thick beds ; it is of a bright 
 black, but less bright than the preceding kind ; 
 what above all distinguishes it, is its great fria- 
 bility ; its surface is always cracked, and its mass- 
 es are divided, with the greatest facility, into a 
 number of cubic pieces, a character which lig- 
 nite jet does not present. In some instances, 
 the tissue of vegetables, which have formed it, 
 is observable. 
 
 " Friable lignite is more abundant, and con- 
 sequently more useful than the two first varieties. 
 It is found in horizontal beds, often thick and 
 extensive, but is never found in such large mass- 
 es as coal, with which it has very improperly 
 been confounded. It not only differs by its pro- 
 perties, but it also differs in its locality. It is 
 found in masses of sand, which often fill calca- 
 
 " * Moorkohle, mud coal. Broch." 
 
DOMAIN VI. CARBONACEOUS. 
 
 reous valleys, or which lean against the hills 
 which skirt them. It is also found, but more 
 rarely, in argillaceous marl. 
 
 " This combustible is common enough in the 
 south of France, particularly in the department 
 of Vaucluse. I have found it under the 
 stances I have just mentioned, at Piolin, near 
 Orange. 
 
 (t It is found in very large mass, at Ruette, 
 department of the Forests. 
 
 <e It easily burns, but emits a very disagree- 
 able odour. It can only be used in manufac- 
 tures, and to burn lime. Smiths cannot use it 
 in their forges. 
 
 " 3. Fibrous lignite *. Its colour varies from 
 a clear blackish brown to a clove brown. It 
 has a perfect woody form and texture, conse- 
 quently its longitudinal fracture is fibrous, and 
 in its transverse fracture are perceived the annual 
 circles of the wood. 
 
 " It is easier to break than wood ; under the 
 knife it assumes a kind of lustre. 
 
 cc This lignite is sometimes found in consider- 
 able masses. 
 
 " It is found in France, in the neighbourhood 
 of Paris, near St. Germain, in the isle of Chatou, 
 
 " * Gemeiner-lituminoses-holz, common bituminous wood. 
 Wern." 
 
MODE IV. LIGNITE. 589 
 
 which seems to be entirely formed of it; and 
 near Vitry, on the banks of the Seine, there is 
 a thick bed of trunks of trees well preserved 
 (Gillet Laumont). In the department of Arriege, 
 the clefts, of this lignite are penetrated with 
 sparry carbonate of lime. In Liguria, near Cas- 
 tel-Nuovo, at the mouth of the Magra, it is in 
 thick and very extensive beds. In Hessia, near 
 the mountain of Ahlberg, the layer is two yards 
 thick. In Steinberg, near Munden in Hanover, 
 it forms two layers, one 10 yards, and the other 
 six, which are separated by a bed of rock from 
 12 to 14 inches thick. In England, at Bovey 
 near Exeter, there are 17 thick beds, which are 
 at a depth of about 66 feet, under sand, and in 
 potters clay. In Iceland it is very abundant, 
 and is called surtitrbrand ; the trunks which 
 form these heaps are very distinct, and seem 
 merely to have been compressed. 
 
 " But this lignite is still more common in little 
 detached masses ; sometimes it accompanies the 
 preceding varieties ; sometimes it is found alone, 
 in small layers, in the midst of beds of argil or 
 of sand. It is met with almost every where, and 
 is used as fuel in those places where it is abun- 
 dant. 
 
 " This vegetable, rather than mineral com- 
 bustible, being scarcely decomposed, would not 
 
DOMAIN VI. CARBONACEOUS. 
 
 deserve to form a variety in the systems of mine- 
 rals, if it did not pass by imperceptible degrees 
 to the varieties which precede it, and to that 
 which follows. Its history, in strict language, 
 more properly belonging to geology, than to 
 mineralogy. 
 
 " Earthy lignite*. This substance is black, 
 or of a blackish brown, mingled with a reddish 
 cast. Its fracture and aspect earthy, fine grain- 
 ed, rather soft, even friable, smooth to the feel, 
 and becomes bright by scraping. It is nearly 
 as light as water. It burns, emitting a disa- 
 greeable smell. 
 
 <c It not only often contains remains of vege- 
 tables, but sometimes itself presents the texture 
 of wood, without ever possessing either the co- 
 lour or brightness, or the hardness of the pre- 
 ceding varieties. 
 
 " Earthy lignite, burns sufficiently free to be 
 used as fuel ; it gives a gentle and equal heat, 
 but exhales an odour generally unpleasant, but 
 sometimes rather agreeable. 
 
 " It is found sometimes in the midst of secon- 
 
 ' * Biluminose hoherde, earthy bituminous wood. Broch. 
 Vulgarly earth of Cologne, and sometimes, but improperly Umler. 
 Umber, properly so called, which comes from Italy, or the East, 
 containing nothing that is combustible, cannot belong to this spe- 
 cies," 
 
MODE IV. LIGNITE. 
 
 591 
 
 dary earths in the neighbourhood of coal mines; 
 sometimes, and even most often, in alluvial land. 
 " We shall mention, as an authentic example 
 of this variety, the earthy lignite of the environs 
 of Cologne, known in trade by the name of earth 
 of Cologne, as it is wrought at a little distance 
 from that city, near the villages of Bruhl and 
 Liblar. This lignite forms very extensive beds 
 of eight or ten yards in thickness, which are si- 
 tuated under considerable elevations. It is im- 
 mediately covered with a bed, more or less thick, 
 of rolled pebbles of quartz and jasper, as large 
 as eggs, and reposes on a bed of white argil, of 
 an unknown thickness. The bed of lignite is 
 homogenous \ but fossil vegetables are found in 
 it, very well preserved. They are, 1. Trunks 
 of trees, lying one on the other, without any 
 order, the wood being black or reddish, generally 
 compressed : they easily exfoliate, by drying in 
 the open air. Some belong to trees of the dico- 
 tyledon kind, others are fragments of palm-trees. 
 Among these, M. Coquebert-Montbret has found 
 some which are full of small round pyritic bodies, 
 resembling grains of small shot *. This wood 
 
 " M. Heimhaa remarked in the lignite of Kalten-nordheim, in 
 Thuringia, small elongated spherical substances, resembling a pod 
 of two partitions. M. Blumenbach supposes them to be unilocuknr 
 bivalve capsules. (Journal des Mines, No. 105.)" 
 
DOMAIN VI. CARBONACEOUS. 
 
 burns very well, and even with a kind of flame. 
 2. Woody fruits, the size of a nut, and which 
 have been known to be those of a species of the 
 palm tree (areca). The lignite of Cologne con- 
 tains about 0,20 of ashes, rather alcaline and 
 ferruginous (Ant. L. Brongniart.) Its uses are 
 various ; it is worked in open air with a simple 
 spade ; but the more easily to transport it, it is 
 wetted, and moulded in vases, which give it the 
 form of a truncated cone. 
 
 " It is used as fuel in the environs of Cologne. 
 It burns slowly but easily, and without flame, 
 like tinder, giving a lively heat, and leaving very 
 fine ashes. These ashes being considered as a 
 very good manure, to obtain them a part of 
 this lignite is burnt on the spot where it is 
 wrought. 
 
 " Earth of Cologne is more especially used 
 for painting in distemper, and even in oil co- 
 lours. The Dutch use it to adulterate their 
 snuff; when it is not mixed in too great a quan- 
 tity it gives the snuff a fineness and softness, 
 which is much esteemed, and cannot be in the 
 least injurious. (Faujas.) 
 
 " This lignite is also said to be found in Hessia, 
 Bohemia, Saxony, Iceland, &c. (Brochant) j but 
 as there has been a confusion between this com- 
 bustible and the variety of ochre, called umber* 
 
MODE IV. LIGNITE. 
 
 we cannot be positive that these local indica- 
 tions have really any relation to earthy lignite. 
 
 " It may have been observed, from what has 
 been just said on the situations peculiar to some 
 varieties of lignites, that this fossil combustible 
 belongs to soils of the most recent formation, 
 since it is only found in accretions of sand or 
 argil. It is almost never met with under rocky 
 beds, except in coarse carbonated lime, and un- 
 der basalt. In the mountain of Ringe Kuhle in 
 Hessia, several thick layers of lignite are ob- 
 served, lying on a sandstone, and separated by 
 layers of potter's clay and sand (Mohs). On 
 the sea shore, near Calais, fragments of lignite 
 have been picked up, which were penetrated 
 with crystals of quartz, very limpid, and disposed 
 in spheres. 
 
 " Lignite then is of a very different formation 
 from that of coal ; and M. Voigt thinks that 
 there is no transition between those two com- 
 bustibles. 
 
 " The air which circulates where lignite is 
 wrought is generally bad*." 
 
 In his Essay on Geology, Faujas has given an of Cologne, 
 accurate and ingenious account of the prodi- 
 gious mass of lignite near Cologne,which extends 
 
 * Brongn. ii. 30. 
 VOL. I, 2 Q 
 
DOMAIN VI. CARBONACEOUS. 
 
 for many leagues, and is covered with a bed of 
 pebbles from 12 to 20 feet in thickness, while the 
 lignite itself exceeds 50 feet*. Our ingenious 
 observer says that the trunks of trees, which 
 are often found, are always deprived of their 
 branches; whence he argues, that they have 
 been conveyed by the ocean. Besides the nuts, 
 which now belong to Hindostan, the Moluccas, 
 and China, masses of a kind of gum or frankin- 
 cense are found, which when burnt perfume the 
 huts of the peasants f . 
 
 Masses of a similar kind have been foand in 
 many quarters of the department of the Aisne ; 
 one of the most remarkable being that near 
 Beaurieux, where a pit sunk to the depth of 65 
 feet, ended in a subterranean marsh, full of sand 
 and water, which soon filled the pit J. In that 
 of Villers- en- Prayer, at the depth of 17 or 18 
 
 * i. 410. 
 
 f There is in Prussia a mine of amber, 98 feet deep, and the am- 
 ber is found between two salbands of lignite, and sometimes adhe- 
 rent. Jour, de Phys. tome xxxix, p. 365. At Vorospatac, in 
 Transylvania, a lignite is found with leaves of gold. Journ. dos 
 Mines, No. 23, p. 83. 
 
 J In Mount Meisner, Hessia, there is a very thick bed of fossil 
 turf, with trunks, branches, and roots of trees, reposing on lime- 
 stone, and covered with basalt. De Luc, Geol. 339, thinks that 
 such hills had sunk under water, and were again elevated. At 
 Schemnitz there is a vein of lignite at the depth of 360 yards. Journ. 
 <les Mines, iv. 807. 
 
MODE IV. LIGNITE. 59-5 
 
 feet, a lignite was found much impregnated with 
 pyrites, as are most others of the Aisne. In this 
 bed of decomposed wood, which is about three 
 feet six inches in thickness, are found pieces of 
 fossile wood, partly carbonised; some bones of 
 animals, seemingly of wild kine; amber in round 
 or angular fragments, some quite transparent 
 and sometimes imbedded in pyrites. Such vene- 
 rable relics must not be confounded with peat, 
 which commonly proceeds from the decompo- 
 sition of graminous and other small vegetables, 
 though trunks, hazel nuts, &c. be occasionally 
 found. Faujas supposes with Patrin, that coal 
 itself may often consist of wood brought by the 
 sea, and deposited in recesses at considerable 
 elevations, when the globe was studded with pri- 
 meval islands. The numerous sea plants, mo- 
 lusks, and oily carcases of so many fish that 
 daily perish, also contribute, in his opinion, to 
 this product 5 but this theory has many diffi- 
 culties. 
 
 Professor Hollman of Gottingen, published in 
 1784 an account, which had before appeared in 
 the Philosophical Transactions, vol. 51, of some 
 hills or mountains, as he calls them, near the 
 city of Munden, and in that point of land which 
 is washed at their junction by the rivers Werra 
 and Fulda; one is about 1150 feet in height, 
 
596* DOMAIN VI. CARBONACEOUS. 
 
 and they may be said almost to consist of fos- 
 sile wood. Another near Altendorf, on the bor- 
 ders of Hessia, about 1800 feet in height, pre- 
 v sents vast quantities of fossile wood, under a stra- 
 tum of stone, not less than from 80 to 140 yards 
 in thickness *. 
 
 Bovey coal. One of the most remarkable lignites is the Bo- 
 vey coal of England, already mentioned. Dr. 
 Kidd observes, that it is attended with a kind of 
 porcelain clay, derived from the waste of the 
 adjoining granite hills, subsiding into this heath, 
 which is a natural basin f . The sandy quartz, 
 and fragments of felspar, correspond with those 
 of the adjacent granite. This lignite often rises 
 in the form of trees, but is often compressed in 
 straight flat pieces, three or four feet in length, 
 which are called board-coal, from a natural re- 
 ' semblance; an observation which may also be 
 
 * Parkinson, Org. Rem. vol. i. He supposes that petrified wood 
 passes through a bituminous fermentation, after which it is saturated 
 with water full of siliceous particles. See also ii. 285, where he 
 adds, that animal matter, by long residence in water, was first con- 
 verted into the adipocere of Fourcroy, resembling spermaceti. This 
 ingenious writer has also observed, i. 364, the presence and in- 
 fluence of bituminous matter in the semi-opal, and other stones of a 
 waxy lustre ; so it may enter into the opal. But as Klaproth only 
 found inflammable matter, may not the carbon, which forms a large 
 proportion of bitumen, here exert its power? 
 
 * Outlines, i. 166. 
 
 -. 
 
MODE IV. LIGNITE. 5 
 
 extended to the surturbrand of Iceland. Mr. 
 Hatchet has, with his usual acuteness and ability, 
 examined many similar substances, as the wood 
 of the submarine forest, off Sutton, on the coast 
 of Lincolnshire, which he found yielded kali, and 
 had no character of coal. An analysis of 200 
 grains of Bovey coal yielded water 60, thick 
 brown oily bitumen 21, charcoal 90, mixed 
 gaz 29. 
 
 The presence of the substances, called by the Origin, 
 chemists extract, resin, and, fibre, are esteemed 
 to evince the original vegetable character, how- 
 ever it may be transmuted or disguised. The ex- 
 cellent experiments of Mr. Hatchet, demonstrate 
 that the extract is the first principle that disap- 
 pears, next the resin, and lastly thejibre. When 
 every mark of organisation has thus disappeared, 
 the substance becomes compact, and the con- 
 choidal fragments resemble pitch*. In this 
 new condition it is called coal, to which the lig- 
 nite of Bovey nearly approximates. In the 
 strata of this substance, Mr. Hatchet also ob- 
 served small masses approaching to the nature of 
 the lignite of Cologne, and which he called re- 
 sinasphaltum, or resinasphalt,as it contains about 
 55 of resin, and 41 of asphalt. 
 
 s Ib. ii. 42. 
 
DOMAIN VI. CARBONACEOUS. 
 
 STRUCTURE I. FIBROUS. 
 
 Aspect 1. Entire. Bovey coal. 
 
 Surturbrand, from Iceland. 
 
 Fibrous lignite, from France, Liguria, c. 
 
 Aspect 2. Mingled. Bovey coal, with resinas- 
 phalt. 
 
 Lignite, with ambe'r, from Prussia. 
 
 STRUCTURE II. FRIABLE. 
 
 From the south of France. 
 
 STRUCTURE III. EARTHY. 
 
 Aspect 1. Entire. Umber or earth of Co- 
 logne. 
 
 Aspect 2. Mingled. The same, with nuts re- 
 sembling the areqa. 
 
 With a gum which burns like frankincense. 
 
 Having thus described the ESSENTIAL ROCKS, 
 or those which receive their divisions and deno- 
 minations from preponderant or from predomi- 
 nant substances, whence they might also be 
 
MODE IV. LIGNITE. 
 
 called SUBSTANTIAL ; it now remains to attempt 
 a clear classification and description of the AC- 
 CIDENTIAL, or those which must necessarily be 
 arranged according to attendant accidents and 
 circumstances. 
 
 END OF THE FIRST VOLUME. 
 
 99 
 
 Primed by S. Hamilton, Weybridg*. 
 
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MONTH 
 
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