BERKELEY 
 
 { LIBRARY \ 
 
 UNIVERSITY OF 
 CALIFORNIA 
 
 EARTH 
 
 SCIENCES 
 
 LIBRARY 
 
 Charles If^ii, Skinner 
 
 a. 0. Noun. 
 
IN MEMORIAL 
 Arthur Eaton 
 
T1IK 
 
 WONDERS OF GEOLOGY; 
 
 GIDEON ALGERNON MANTELL, LL.D. F.R.S. 
 
 IUTHOR OP 
 
 Silver Coin* of Edward the First, in ironitone.Page 67. 
 
 EDITED BY PROFESSOR SILLIMAN, 
 
 WITH AN INTRODUCTION. 
 
 IN TWO VOLUMES. 
 VOL. I. 
 
 FIRST AMERICAN, FROM THE THIRD LONDON EDITION. 
 
 A. H. MALTBY, NEWHAVEN, CONNECTICUT; 
 RELFE AND FLETCHER, LONDON. 
 
 1839. 
 
THE 
 
 WONDERS OF GEOLOGY; 
 
 GIDEON ALGERNON MANTELL, LL.D. F.R.S. 
 
 THE G: OLOOY OV THE SOUTH EAST OF ENGLAND, 
 ETC. ETC. 
 
 Silver Coin* of Edward the First, in ironttone.1'nu'' I'.". 
 
 " To tha natural philosopher there is no natural object unimportant 
 or trifling : from the least of nature's works he may learn the greatest 
 lessons." SIB J. F. W. HERSCHEL. 
 
 "We know not a millionth part of the wonders of this beautiful 
 world." LEIGH HUNT. 
 
 IN TWO VOLUMES. 
 VOL. I. 
 
 FIRST AMERICAN, FROM THE THIRD LONDON EDITION. 
 
 A. H. MALTBY, NEWHAVEN, CONNECTICUT; 
 RELFE AND FLETCHER, LONDON. 
 
 1839. 
 
ENTERED 
 According to the Act of Congress in the year 1839, 
 
 BY A. H. MALTBY, 
 In the Clerk's Office of the District of Connecticut. 
 
 LONDON : 
 RICHARD CLAY, PRINTER, BREAD STREET HILL. 
 
THE 
 
 WONDEES OF GEOLOGY ; 
 
 OR, 
 
 A FAMILIAR EXPOSITION 
 OF 
 
 GEOLOGICAL PHENOMENA ; 
 
 BEING THE SUBSTANCE OF A COURSE OF LECTURES 
 DELIVERED AT BRIGHTON. 
 
 BY 
 
 GIDEON ALGERNON MANTELL, LL.D. F.R.S. 
 
 FELLOW OP THE ROYAL COLLEGE OF SURGEONS; 
 
 CORNWALL I 
 
 F THE ACADEMIES OF NATURAL SCIENCES OF PHILADELPHIA; AND OF ARTS AN 
 SCIENCES OF CONNECTICUT; OF THE GEOLOGICAL SOCIETY OF PENNSYLVANIA; 
 
 OF THB PHILOSOPHICAL INSTITUTION OF BOSTON; 
 
 OF THE HISTORICAL SOCIETY OF QUEBEC; AND OF THE PHILOSOPHICAL 
 SOCIETIES OF YORK, NEWCASTLE, ETC. 
 
 " Horum conternplatio multiplicem habct usutn. Sunt instar nummoruni 
 mernorialium, quae de preteritis globi nostri fatis testantur, ubi omnia 
 silent monumcnta historica." BERGMAN. Med. de Syst. Fast. 
 
 IN TWO VOLUMES. 
 VOL. I. 
 
 FIRST AMERICAN, FROM THE THIRD LONDON EDITION. 
 
 A. H. MALTBY, NEWHAVEN, CONNECTICUT; 
 RELFE AND FLETCHER, LONDON. 
 
 1839. 
 
v.l 
 
 EARTH 
 
 SCIENCES 
 
 LIBRARY 
 
BENJAMIN SILLIMAN, ESQ. LL.D. M.D. 
 
 PROFESSOR OF CHEMISTRY AND OF MINERALOGY 
 IN YALE COLLEGE; 
 
 EDITOR OF THE AMERICAN JOURNAL OF SCIENCE ; 
 FOREIGN MEMBER OF THE GEOLOGICAL SOCIETY OF LONDON, 
 
 :&c. &c. 
 
 OF 
 
 THE WONDERS OF GEOLOGY" 
 
 IS DEDICATED, 
 IN TESTIMONY OF THE HIGH RESPECT, 
 
 AND AFFECTIONATE REGARD, 
 OF HIS MUCH OBLIGED FRIEND,' 
 
 THE AUTHOR. 
 
 CRESCENT LODGE, CLAPHAM COMMON, 
 
 SURREY, ENGLAND. 
 
 MAY 1, 1839. 
 
 690899 
 
PREFACE. 
 
 IN preparing the first edition of this Work for 
 the press, I was greatly assisted by the kindness 
 and zeal of my friend, G. F. Richardson, Esq.* 
 whose ability as a reporter enabled him to 
 furnish me with copious notes of the Lectures 
 which I delivered at Brighton, in an unsuc- 
 cessful attempt to establish a County Museum, 
 and Scientific Institution in that town. Those 
 notes were the ground-work of the unpretend- 
 ing volumes which, under the title of " THE 
 WONDERS OF GEOLOGY," have met with so 
 favourable a reception. 
 
 The former publication, consisting of two 
 thousand copies, having been disposed of in 
 the course of a few months, a new edition is 
 required, and I have therefore carefully revised 
 
 * Of the British Museum. 
 
viii PREFACE. 
 
 the Work, and made such corrections and 
 additions as the leisure moments which my 
 professional engagements have allowed me, 
 would permit. 
 
 The additional illustrations are both nume- 
 rous and important, and I trust will be found to 
 enhance the interest of these volumes, without 
 having materially increased their size or price. 
 
 My geological collection, consisting of up- 
 wards of twenty thousand specimens, from which 
 the subjects for the illustration of the Lectures 
 were selected, was, at the period of the former 
 editions, exhibited at Brighton by the Sussex 
 Literary Institution, as the " Mantelllan Mu- 
 seum" At that time I had every reason to 
 believe that my collection would be permanently 
 established in Sussex, and serve as the foun- 
 dation for a County Museum. In that expecta- 
 tion I have, however, been utterly disappointed ; 
 for although I would willingly have made any 
 pecuniary sacrifice, to accomplish what appeared 
 to me so desirable an object, yet after the 
 death of my noble and lamented friend, the 
 late Earl of Egremont, the munificent patron 
 of the Institution, the proposed measure was 
 abandoned, and even opposed by many of its 
 
PREFACE. 
 
 former supporters. T have therefore, in compli- 
 ance with the wishes of my scientific friends, 
 disposed of my entire collection to the Trustees 
 of the British Museum. 
 
 But although the main object of my labours 
 has thus been frustrated, and that collection, 
 which would have been of tenfold importance 
 if located in the district from whence it was 
 derived, and whose physical structure it was 
 designed to illustrate, is now broken up, and 
 will be dispersed through the cabinets of our 
 National Institution, yet the most interesting 
 specimens are so unique, and so strikingly dis- 
 tinct from any others hitherto obtained, that 
 they may be referred to with facility, when the 
 gallery of organic remains in the British Mu- 
 seum shall be finally arranged. 
 
 I avail myself of this means to record the 
 deep sense of obligation I feel to many ex- 
 cellent friends, for their strenuous and unre- 
 mitting exertions to prevent the dispersion of 
 my Museum, and establish it on a permanent 
 basis in my native county. And although their 
 efforts have proved unavailing, a time will 
 assuredly come, when their endeavours to pro- 
 mote a taste for scientific knowledge among 
 
x PREFACE. 
 
 the intelligent inhabitants of Sussex, and to 
 direct attention to the investigation of its 
 physical phenomena, will be properly appre- 
 ciated, and the failure of their attempt to 
 secure to the county a collection so rich in its 
 peculiar fossil and mineral productions, be re- 
 membered with regret. 
 
 Should Providence allot me life and health, I 
 purpose adding another volume to this Work, 
 under the title of " FIRST LESSONS, or an In- 
 troduction to THE WONDERS OF GEOLOGY ; " 
 being the substance of a series of Lectures, 
 designed for persons wholly unacquainted with 
 the nature of geological investigations. 
 
 G. A. M. 
 
 CRESCENT LODGE, CLAPHAM COMMON, 
 May 1, 1839. 
 
TABLE OF CONTENTS. 
 VOL. I. 
 
 LECTURE I. 
 
 Introductory remarks. 2. Importance of geology. 3. Nature of 
 geology. 4. Harmony between revelation and geology. 5. Extent 
 of geological epochs. 6. Object of the lectures. 7. Physical struc- 
 ture of the earth. 8. Geographical distribution of animals and 
 vegetables. 9. Temperature of the earth. 10. Nature of the crust of 
 the globe. 11. Composition of the rocks and strata. 12. Classification 
 of rocks. 13. Primary rocks. 14. Transition strata. 15. Secondary 
 strata. 16. Tertiary strata. 17. Alluvial deposits. 18. Geological 
 mutations. 19. Connexion of geology with astronomy. 20. Nebular 
 theory of the universe. 21. Different states of nebulae. 22. Formation 
 of the solar system. 23. Gaseous state of the earth. 24. Geology 
 illustrated by astronomy. 25. Meteorites. 26. Mrs. Somerville on 
 meteorites. 27. Origin of meteorites. 28. Existing geological 
 changes. 29. Effects of streams and rivers. 30. Delta of the Ganges 
 and Mississippi. 31. Formation of strata. 32. Rippled sand. 33. 
 Lewes levels. 34. Remains of man in modern alluvium. 35. Peat 
 bogs. 36. Conversion of peat into coal. 37. Subterranean forests. 
 38. Geological effects of the sea. 39. Bed of the ocean. 40. Currents 
 and their effects. 41. Incrusting springs. 42. Incrustations not 
 petrifactions. 43. Lake of Solfatara. 44. Marble of Tabreez. 45. 
 Stalactites and stalagmites. 46. Grotto of Antiparos. 47. Consoli- 
 dation of sand and loose materials. 48. Destruction of rocks by carbonic 
 acid. 49. Carbonic acid gas in caverns and wells. 50. Consolidation 
 of loose strata by iron. 51. Recent formation of marine limestone 
 in the Bermudas. 52. Fossil human skeletons of Guadaloupe. 53. 
 Impressions of human feet in sand-stone. 54. Isle of Ascension. 
 55. Drifted sand. 56. Sand-flood and recent limestones of Cornwall. 
 57. Silicious deposits. 58. The Geysers. 59. Hertfordshire con- 
 glomerate, or pudding-stone. 60. Effects of high temperature. 61. 
 Volcanic agency. 62. Expansion of rocks by heat. 63. Temple of 
 Jupiter Serapis. 64. Elevation of the coast of Chili. 65. Lifted sea 
 beach at Brighton. 66. Elevation of Scandinavia. 67. Retro- 
 spect p. l 
 
xii TABLE OF CONTENTS. 
 
 LECTURE II. 
 
 Introductory observations. 2. Extinction of animals. 3. Animals 
 extirpated by human agency. 4. The apteryx australis. 5. The dodo. 
 6. The Irish elk. 7. Epoch of terrestrial mammalia. 8. Character 
 of the ancient alluvial deposits. 9. Classification of mammalian re- 
 mains. 10. Comparative anatomy. 11. Adaptation of structure in 
 animals. 12. Osteological characters of the carnivora. 13. Structure 
 of the herbivora. 14. Structure of the rodentia, or gnawers. 15. 
 General inferences. 16. Fossil bones. 17. Fossil elephants, or mam- 
 moths. 18. Mammoth and rhinoceros in ice. 19. Teeth of recent, 
 and fossil elephants. 20. The mastodon. 21. Mastodons from the 
 Burmese empire. 22. The sivatherium. 23. The megatherium. 24. 
 The megalonyx. 25. The sloth. 26. Fossil hippopotamus, rhinoceros, 
 horse, &c. 27. The dinotherium. 28. Fossil carnivora in caverns. 
 29. Cave of Gaylenreuth. 30. Forster's Hohle. 31. Bone caverns in 
 England. Kirkdale cave. 32. Diseased bones of carnivora found 
 in caves. 33. Human bones, and works of art in caverns. 34. Osseous 
 breccia, or bone conglomerates. 35. The rock of Gibraltar. 36. Osseous 
 breccia of Australia. 37. Retrospect p. 113 
 
 LECTURE III. 
 
 I. Introductory remarks. 2. Substances composing the crust of the 
 globe. 3. Crystallization. 4. Stratification. 5. Inclined and vertical 
 strata. 6. Veins and faults. 7. Chronological arrangement of the 
 strata. 8. Tertiary formations. 9. Classification of the tertiary strata. 
 10. Fossil shells. 11. Mineralogical characters of the tertiary system. 
 12. Newer tertiary or pliocene deposits. 13. Crag of Norfolk and 
 Suffolk. 14. The Sub-Apennines. 15. Middle tertiary, or miocene 
 deposits. 16. Lower tertiary, or eocene deposits. 17. The Paris basin. 
 18. The London basin. 19. The Isle of Sheppey. 20. Fossil fruits of 
 the tertiary strata. 21. Upper marine, or Bagshot sand. 22. Artesian 
 wells. 23. The Hampshire or Isle of Wight basin. 24. Alum bay. 
 25. London clay of the Hampshire basin. 26. Fresh-water strata of the 
 Isle of Wight. 27. Organic remains of the Paris, London, and Hants 
 basins. 28. Fossil plants and zoophytes. 29. Tertiary marine and 
 fresh-water shells. 30. Nummulites, and other cephalopoda. 31. Crus- 
 tacea and fishes. 32. Fossil birds. 33. Fossil animals of Paris. 34. 
 Palaeotheria and anoplotheria. 35. Fossil quadrumana, or monkeys. 
 36. Tertiary strata of Aix, in Provence. 37. Fossil insects. 38. Lacus- 
 trine formation of (Eningen. 39. Fossil fishes of Monte Bolca. 40. 
 Tertiary volcanoes of France. 41. Extinct volcanoes of Auvergne. 
 
TABLE OF CONTENTS. xiif 
 
 42. The crater of Puy de Come. 43. Mont Dor. 44. Fresh-water lime- 
 stone and organic remains of Auvergne. 45. Summary of the geological 
 phenomena of Auvergne. 46. Erosion of valleys by water-currents. 
 47. Extinct volcanoes of the Rhine. 48. Brown coal formation. 49. 
 Other tertiary strata of Europe, North America, &c. 50. Altered ter- 
 tiary strata of the Andes. 51. Tertiary saliferous deposit. 52. Retro- 
 spect. 53. Concluding remarks p. 184 
 
 LECTURE IV. 
 
 Introductory remarks. 2. Secondary formations. 3. The chalk for- 
 mation. 4. Chalk and flint. 5. Flint nodules. 6. Organic remains 
 in flint. 7. Sulphuret of iron. 8. Maestricht beds. 9. St. Peter's 
 mountain. 10. Mossesaurus of Maestricht. 11. Lower group of the 
 chalk. 12. Organic remains of the chalk. 13. Fossil vegetables. 
 14. Fossil zoophytes. 15. Radiaria and crinoidea. 16. Echinites. 
 17. Shells of the chalk. 18. Cephalopoda. 19. The belemnite. 20. 
 The nautilus. 21. The ammonite, or cornu ammonis. 22. Turrilite, 
 hamite, &c. 23. Spirolinites. 24. Infusoria in flint. 25. Crustacea 
 of the chalk. 26. Fishes of the chalk sharks. 27. Fossil salmon, 
 or smelt. 28. Macropoma, and other fishes of the chalk. 29. Reptiles 
 of the chalk. 30. Review of the chalk formation. 31. Geology of the 
 south-east of England. 32. Geological phenomena between London 
 and Brighton. 33. The wealden. 34. Wealden of the Sussex coast. 
 35. Pounceford. 36. Sub-division, and extent of the wealden. 37. 
 Quarries of Tilgate forest. 38. Rippled sandstone. 39. Wealden of 
 the Isle of Wight. 40. Isle of Purbeck. 41. Petrified forest of the 
 Isle of Portland. 42. Modern submerged forest. 43. Fossils of the 
 wealden. 44. Fossil vegetables ferns. 45. Clathraria and endo- 
 genites. 46. Seed-vessels. 47. Fossil shells. 48. Sussex marble. 
 49. Fossil cypris. 50. Fishes. 51. Reptiles of Tilgate forest. 52. 
 Fossil turtles. 53. Fossil crocodiles. 54. The Swanage crocodile. 
 55. The plesiosaurus. 56. The megalosaurus. 57. The iguanodon. 
 58. The Maidstone iguanodon. 59. Size of the iguanodon. 60. The 
 hylaeosaurus. 61. Flying reptiles. 62. Fossil birds. 63. The country 
 of the iguanodon. 64. Sequence of geological changes. 65. Retro- 
 spect of geological mutations p. 287 
 
 APPENDIX. 
 
TABLE OF CONTENTS. 
 VOL. IT. 
 
 LECTURE V. 
 
 1. The zoological character of the chalk. 2. Zoological character of the 
 wealden. 3. Site of the country of the iguanodon. 4. Medial secon- 
 dary formations. 5. The oolite, or Jura limestone. 6. Tabular view 
 of the oolite and lias. 7. Geographical distribution of the oolite and 
 lias. 8. Stonesfleld slate. 9. Organic remains of the Stonesfield 
 slate. 10. Fossil opossum of Stonesfield. 11. Wealden and Stones- 
 field fossils. 12. Lithographic slates of Pappenheim, Solenhofen, 
 andMonheim. 13. Coal of the oolite. 14. Geographical distribution 
 of the lias. 15. Organic remains of the oolite and lias. 16. State of 
 fossilization. 17. Saliferous, or new red sandstone system. 18. Tabular 
 view of the saliferous system. 19. Geographical distribution of the 
 saliferous strata. 20. Cheltenham waters. 21. Rock-salt and brine- 
 springs. 22. Magnesian limestone, or zechstein. 23. Conglomerates 
 of the new red sandstone. 24. Organic remains of the saliferous 
 strata. 25. The spiriferae of the new red sandstone. 26. Impressions 
 of the feet of animals on sandstone. 27. Reptiles. 28. Turtles. 
 29. Fossil turtles. 30. Crocodiles. 31. The ichthyosaurus. 32. The 
 plesiosaurus. 33. Pterodactyles, or flying reptiles. 34. Fossil sala- 
 mander. 35. Fossil reptiles allied to the lizards. 36. Review of the 
 Age of reptiles. 37. Objections considered. 38. Concluding re- 
 marks P- 429 
 
 LECTURE VI. 
 
 1. Introductory remarks. 2. Organic and inorganic kingdoms. 3. Dis- 
 tinctive characters of animals and vegetables. 4. Nervous system, 
 and sensation. 5. Diversity of animal forms. 6. Ellis's discoveries. 
 7. Nature of sponge. 8. Cilia, or vibratile organs. 9. The hydra, or 
 fresh-water polype. 10. Zoophytal organization. 11. The food of 
 zoophytes. 12. Mode of increase and death. 13. Corals, or skeletons 
 of zoophytes. 14. Diversity of form and structure. 15. Geographical 
 distribution of the polyparia. 16. The flustra, or sea-mat. 17. The 
 
TABLE OF CONTEXTS. xv 
 
 vesicular corallines, or serttilariae. 18. The gorgonia, or sea-fan. 
 19. The red coral. 20. The tubipora, or organ-pipe coral. 21. Ma- 
 drepores. 22. The actinia, or sea-anemone. 23. Caryophyllia and 
 turbinoiia. 24. Fungia. 25. Astrea, pavonia, &c. 26. Meandrina 
 cerebrifovmis, or brain-coral. 27. Appearance of the living corals. 
 28. Coiai reel's. 29 Coral reef of Loo Choo. 30. Coral islands. 31. 
 Fossil zoophytes. 32. Zoophytes of the chalk. 33. Zoophytes of the 
 Shanklin sand. 34. Recent formation of chalk from corals. 35. Fossil 
 infusoria. 3t>. Corals of the oolite and lias. 37. Corals of the older 
 secondary formations. 38. Coralline marbles. 39. The crinoidea, or 
 lily-shaped animals. 40. Encrinites and Pentacrinites. 41. Struc- 
 ture of the crinoiuea. 42. The lily encrinite. 43. Pear encrinite of 
 Bradford. 44. Pentacrinites, actinocrinites, and other crinoidea. 45. 
 Derbyshire encrinital marble. 46. Geological distribution of the cri- 
 noidea. 47. Concluding remarks p. 505 
 
 LECTURE VIT. 
 
 Introductory remarks. 2. The carboniferous system. 3. The coal 
 measures. 4. Coal-field of Derbyshire. 5. Coalbrook dale. 6. Coal- 
 shales, and vegetable remains. 7. Carboniferous, or mountain lime- 
 stone. 8. Derbyshire lead mines. 9. Carboniferous system of 
 Devonshire. 10. The Devonian system, or old red sandstone. 11. 
 Geographical distribution of the carboniferous system. 12. Volcanic 
 rocks of the carboniferous system. 13. Trap-dikes of the carboni- 
 ferous sjstem. 14. Organic remains of the carboniferous system. 
 15. Organization of vegetables. 1C. Coniferous trees. 17. Climate 
 and seasons, indicated by fossil wood. 18. Vertical trees in carboni- 
 ferous strata. 19. Trunks of coniferae in Craigleith quarry. 20. 
 Microscopic examination of fossil trees. 21. Nature of coal. 22. 
 Mineral oil, naphtha, and petroleum. 23. Bitumen, amber, and 
 mellite. 24. The diamond. 25. Anthracite, cannel coal, and plum- 
 bago, or graphite. 26. Nature of petrifaction. 27. Artificial pe- 
 trifactions. 28. Different states of the fossilization of wood. 29. 
 Hazel-nuts filled with spar. 30. Silicification, or petrifaction by silex. 
 31. Plants in agates, &c. 32. Plants of the coal formation . 33. Fossil 
 mare's-tail, or equisetum. S4. Fossil ferns. 35. Sigillariae, or fossil 
 arborescent ferns. 36. Lepidodendron. 37. Fossil club-moss, or 
 lycopodites. 38. Stigmaria. 39. Seed-vessels in coal. 40. Coniferae. 
 41. Review of the carboniferous flora. 42. Formation of new coal- 
 measures. 43. Corals and crinoidea of the carboniferous system. 
 44. Shells of the carboniferous system. 45. Crustacea. 46. The 
 limulus, or king-crab. 47. Trilobites. 48. The eyes of the trilobite. 
 49. Insects of the coal formation. 50. Fishes of the carboniferous 
 and Devonian systems. 51. Retrospect the flora of the ancient 
 world P- 595. 
 
xvi TABLE OF CONTENTS. 
 
 LECTURE VIII. 
 
 Introductory remarks. 2. Silurian and Cambrian systems. 3. Silurian 
 system. 4. Cambrian, or slate system. 5. Structure of slate rocks. 
 6. Organic remains of the Silurian and Cambrian systems. 7. Meta- 
 morphic character of slate and greywacke. 8. Metamorphic or pri- 
 mary rocks. 9. Mica-schist and gneiss. 10. Unstratified metamorphic 
 rocks granite. 1 1 . Volcanic agency. 12. Vesuvius. 13. Eruptions 
 of Vesuvius. 14. Volcanic products of Vesuvius. 15. Mount Etna. 
 16. Phlegrean fields, and the Lipari isles. 17. Volcano of Kirauea 
 Hawaii. 18. Stewart's visit to Kirauea. 19. Earthquakes. 20. Vol- 
 canic island in the Mediterranean. 21. Volcano of Jorullo, in Mexico. 
 22. Organic remains buried beneath lava. 23. Ice preserved by in- 
 candescent lava. 24. Herculaneum and Pompeii. 25. Professor 
 Silliman on geological evidence. 26. Basalt or trap. 27 Staffa 
 Fingal's cave. 28. The Giants' Causeway. 29. Rocks altered by con- 
 tact with basalt. 30. Trap dikes and veins. 31. Strata altered by 
 contact with metamorphic rocks. 32. Granite veins. 33. Metamorphic 
 rocks. 34. Metalliferous veins. 35. Copper ore of New Brunswick. 
 36. The sapphire, ruby, and emerald. 37. Review of the Silurian 
 and Cambrian systems. 38. Review of the metamorphic rocks. 31*. 
 Organic remains (?) in the metamorphic rocks. 40. Relative age of 
 mountains. 41. Successive changes in the organic kingdoms. 42. 
 Successive development of the organic kingdoms. 43. Geological 
 effects of mechanical and chemical action. 44. Rocks composed of 
 organic remains. 45. General inferences. 46. Final causes. 47. 
 Geological theory of Leibnitz. 48. Astronomical relations of the solar 
 system. 49. Concluding remarks p. 692 
 
 APPENDIX. 
 
PROFESSOR SILLIMAN'S 
 REMARKS 
 
 INTRODUCTORY TO THE FIRST AMERICAN EDITION 
 OF 
 
 DR. MANTELL'S WONDERS OF GEOLOGY. 
 
 1. OBJECT OF THE SCIENCE. Geology* is the natural, 
 history of the earth. Its hills and mountains, its rivers, 
 lakes, seas, and oceans, its caverns and valleys, its fertile 
 plains and sterile deserts in a word, all that belongs to 
 physical geography, is included within its domain. Inci- 
 dentally, it takes notice of villages, towns, and cities, of 
 works of art, of agriculture and commerce, of the various 
 improvements of civilization, and of the races and families 
 of animated beings of both organic kingdoms, since they 
 are all influenced by geological causes, and affected, more 
 or less, by geological events, while they, in turn, afford 
 monumental evidence of the physical history of the globe. 
 The terrestrial surface sympathizes with the profound in- 
 terior, and its physiognomy is often changed by the operation 
 of internal causes ; just as the human face becomes fallen 
 and pale, or full and glowing, as it is affected either inju- 
 riously by internal disease, or cheered by the health of the 
 body. Every thing upon this earth is, therefore, more or 
 less concerned with geology, and this science, in turn, 
 
 * From 7, the earth, and Xo-yor, an account of. 
 b 
 
--. 
 
 reviews the principal* facts' 'and events (more especially 
 those of a physical nature) of which this planet is the 
 theatre. 
 
 But, the more appropriate object of geology is to ascer- 
 tain the structure of the earth, and to deduce from the 
 facts a legitimate theory. It includes a knowledge of the 
 masses of which our planet is composed the order of their 
 arrangement their mineral and organic contents the 
 proximate causes by which they were formed and depo- 
 sited, and those by which they are rendered liable to future 
 changes. 
 
 2. PRELIMINARY KNOWLEDGE. These considerations 
 necessarily involve a knowledge of physical laws. We 
 must be acquainted with the chemical constitution of 
 matter, with the combinations its elements are capable of 
 forming, with the liabilities of the compounds to form new 
 arrangements, and with the secret laws governing these 
 events. The mechanical laws must also be kept in view ; 
 the weight and pressure and moving power of both solids 
 and fluids, the varieties and force of attraction ; in a word, 
 the dynamics of our globe. Nor can it be considered 
 entirely apart from its planetary relations, as a member of 
 the solar system, and of the innumerable systems which 
 compose the stellar universe. Remotely then, but still dis- 
 tinctly and efficiently, the earth must be viewed in its 
 astronomical connexion, out of which grow important 
 analogies and elucidations. 
 
 Those subtile agents, unknown in their essence, but most 
 manifest and potent in their effects namely, heat, light, 
 electricity, and magnetism, either distinct, or combined in 
 various modifications, demand a faithful study, that we 
 may comprehend their manifold and unceasing effects in 
 the economy of the earth ; nor must the enveloping ocean 
 of aerial fluid, the atmosphere, in which their energy is so 
 yften displayed, be forgotten; both in its physical and 
 
chemical characters, it demands our attention. We must 
 also know the outlines of natural history, especially of the 
 mineral species, or at least, of those which are, or have 
 been, chiefly concerned in producing, by their extension or 
 aggregation, the mountains and continents, and the entire 
 planet, so far as it is cognizable by man. A competent 
 knowledge of mineralogy ought, therefore, to precede the 
 study of geology ; it is true, we may begin with a com- 
 paratively small number of the most important minerals, 
 as our increasing acquaintance with rocks will constantly 
 augment our familiarity witli mineral species. 
 
 In like manner, as mineralogy is indispensable to the 
 study of geology, so the other departments of natural 
 history are auxiliary to it, in a most important degree. 
 Animals and plants, either entire or dismembered, or in 
 fragments and ruins, are involved in almost all classes of 
 rocks, except the primary and the volcanic ; nor can we 
 assign the limit of organic matter even in these, for we 
 know not how far fire, by softening or fusion, may have 
 obliterated the organic remains that might once have been 
 blended with materials now exhibiting no vestige of plants 
 or animals. Although we may not be able to mark the 
 precise boundary beyond which organic beings do not 
 appear, it is certain that in all geological epochs, subse- 
 quent, at least, to that of the primary rocks, animals and 
 plants have existed in successive families ; they have been 
 created, have lived their day, and by the operation of 
 physical causes, have perished ; while new races have been 
 called into being, and in their turn have ceased to be, in 
 order to give room to other families, requiring, perhaps, a 
 different climate, and a new order of things. 
 
 Thus we travel onward in time, and upward in the order 
 of deposition, through races whose species are entirely ex- 
 tinct, until we arrive at the periods that approximate to our 
 own times, when first, similar beings to those that now 
 62 
 
inhabit the earth begin to appear, and finally to graduate 
 into those of the present day. Now it is obvious, that to 
 judge intelligently of extinct races of beings, once endowed 
 with animal or vegetable life, it is requisite to pass in 
 review the entire organic creation, both of ancient and mo- 
 dern date ; not only of the terrestrial animals that, in early 
 time, walked the earth, of the fishes or amphibia that swam 
 in its waters, of the birds, insects, and winged reptiles, that 
 soared in the air, and of plants that adorned its new-born 
 islands and emerging continents, and which, as well as the 
 animals, are now entombed in rocks and mountains ; but 
 we must be familiar, also, with the races which, at this 
 moment, fill the world with animation and beauty, for they 
 are our living standards of comparison. In short, we must 
 be well acquainted with both natural history and con^ra- 
 tive anatomy. 
 
 If such be the circle of sciences preliminary or auxiliary 
 to geology, it may well draw from us the desponding ex- 
 clamation, Who then is sufficient for these things? We 
 may perhaps reply, no unassisted individual ! Science is 
 formed by the joint labours of many minds. Different cul- 
 tivators bring in the rich tribute of the fields they have 
 tilled and reaped, and a master-mind disposes them in 
 order, and draws from them the requisite resources, to 
 construct a system, or at least, to furnish its most impor- 
 tant elements. 
 
 3. RANK AMONG THE SCIENCES. This very general 
 sketch of the relations which geology sustains to the colla- 
 teral sciences, is sufficient to evince its high importance, 
 and to vindicate its strong claims to our warm regard. 
 
 As a science, it is true, its date is modern;* but this is 
 
 * Mr. Lyell, in the historical introduction to his Principles of Geology, 
 lias, however, cited a number of early authors who have expressed just 
 views, and pointed out, at least to a certain extent, the proper course to 
 be pursued. 
 
also the case with all the physical sciences, among which 
 geology is a younger sister. Although it is rapidly 
 advancing, and is, therefore, not perfect, it is still a science ; 
 and in this sense, which of the phj^sical sciences is perfect? 
 A few hundred years will include the dates of most of them, 
 while all are still advancing, and will continue to advance. 
 In this respect geology is, therefore, not alone. Its ascer- 
 tained facts are numerous ; they are correctly observed and 
 reported ; they are skilfully classed, and a a sufficient num- 
 ber of general as well as particular conclusions has been 
 drawn from them to furnish the basis of a noble science. 
 Its boundaries are daily extending, and will be extended 
 without limit, by continued observations its evidence will 
 conjointly accumulate, and although its theoretical specu- 
 latwfcs may change, nothing can occur to subvert the grand 
 conclusion, that the earth has a regular structure, and that 
 its materials have been arranged under the operation of 
 general and immutable laws, the physical expression of 
 omniscient intelligence, and omnipotent sway, guided by 
 benevolent design, which becomes more and more apparent 
 and convincing with every new and successful research in 
 geology. 
 
 4. SOURCES OF ITS EVIDENCE. If the inquirer asks for 
 the source of geological evidence, it may be answered that 
 it is derived from diligent and careful examination of the 
 structure of the earth, and for this object our means are 
 more ample than might at first appear. 
 
 Every artificial excavation every well and cellar every 
 cut for a fort, common road, railway, or canal every 
 quarry every tunnel through a mountain and every 
 pit and gallery of a mine bored into the solid earth, 
 furnish means of investigating its interior. Still more 
 do the inland precipices, and the rocky promontories and 
 headlands along the rivers, lakes, seas, and oceans; 
 the naked mountain-sides ribbed with strata, that bound 
 
6 
 
 the defiles, gorges, and valleys ; the ruins accumulated at 
 the feet of lofty pinnacles and harriers, and those that have 
 been transported and scattered, far and wide, over the 
 earth; present us with striking features of the internal 
 structure of our planet. Most of all, do the inclined strata 
 push up their hard edges, in varied succession, and thus 
 faithfully disclose the form and substance of the deep in- 
 terior, as it exists many miles and leagues beneath the 
 observer's feet. 
 
 Volcanic eruptions elevate the foundations of the fathom- 
 less deep below, either in the form of ejected or molten 
 masses; or in rivers of ignited and fluid rocks, which 
 congeal on the surface of the ground, either inflated like 
 the scoriae of furnaces, or in solid forms, with no visible 
 impress of heat, and often containing very perfect^ and 
 beautiful minerals, conceived in the volcano; or dislodged 
 from still earlier beds, from a more profound igneous abyss, 
 and urged along by the irresistible current which often 
 ruptures the crust of the earth, and covers it with a fiery 
 deluge. In addition to the products of actual volcanoes 
 the ignigenous rocks, crystallized or deposited from fusion 
 both in the earliest and in many of the more modern 
 epochs injected among, and cutting across strata of almost 
 all descriptions and ages, and thus assimilated to known 
 products of internal fire; the proper rocky masses the 
 granites the sienites the porphyries the serpentines and 
 the traps, give authentic information of the unapproachable 
 gulf of fire whence they were projected. 
 
 The internal waters that gush cool from the fountains on 
 land or under the sea, or those that spout in boiling geysers 
 from the deep caverns where their imprisoned vapours 
 accumulate explosive force ; all these bring to the surface 
 the materials of the interior, and conspire with tornadoes 
 of gas, bursting from volcanoes and other vents, to reveal 
 the deep secrets of the earth. 
 
5. ITS POSITIVE UTILITY. Geology, in addition to its 
 inherent dignity, puts forth strong claims to regard on the 
 ground of positive utility. Every thing reposes upon the 
 mineral kingdom. This earth affords to man, directly or 
 indirectly, all the materials of his physical comfort all 
 those of national wealth, and all the means of civilization. 
 A mere savage, ignorant and brutal, and the creature of 
 appetite alone, can never rise from his degradation, until 
 he has learned to draw from the mineral kingdom the 
 instruments of arts and civilization, or, at least, to use the 
 aids that are thus obtained. The axe, the hoe, the plough, 
 the loom, are inseparable means and companions of his 
 advancement ; and even moral instruction is wasted upon 
 him, while he remains a brute. He cannot begin to prac- 
 tise Athe Christian virtues while he is sunk in ignorance, 
 for physical comforts as well as moral culture are indis- 
 pensable to his elevation. The most important of physical 
 instruments are derived, immediately or remotely, from the 
 mineral kingdom, for the vegetable world, equally with the 
 animal, rests upon this basis; whether we speak of the 
 cedar, the oak, the lichens, or the grasses, all equally 
 derive their support from the elements afforded by the 
 mineral world, which, in its widest sense, includes not 
 only the solid earth, but its waters, and all its fluids its 
 atmosphere, and all its gases. The vegetable kingdom 
 borrows from the mineral world oxygen, carbon, hydro- 
 gen ; and even nitrogen and all that are indispensable 
 to vegetable life are found in the waters and the atmo- 
 sphere, while other elements or compounds, adapted to 
 particular purposes, are derived from various mineral 
 sources ; the soil, for example, affords silica, to give 
 strength to the epidermis of grasses, bamboos, equi- 
 seta, &c. ; and potassa and soda, derived from decom- 
 posed felspar and from other minerals, pass by absorption 
 into the juices of plants. Even animal and vegetable 
 
8 
 
 manures form no exception, for their elements have a similar 
 origin, and consist almost entirely of the substances indis- 
 pensable to vegetable growth. While, therefore, we explore 
 this orb of fire and water, and solid rock, we shall gain the 
 most interesting knowledge, and much positive advantage. 
 Our beautiful planet is indeed worthy of our study ; it 
 was once our cradle it will soon be our grave : between 
 the dawn and the night of life, it is the scene of our busy 
 action, and from it we shall rise to another state of being. 
 
 6. DISCOVERY OF USEFUL, MINERALS. Geology discloses 
 to us the valuable minerals, such as are useful to society, 
 and teaches us where to expect them, and where research 
 would be vain. 
 
 Coal* Duly informed in this science,, we should never 
 look for coal in granite, nor among beds of sand and clay, 
 and in the wide intervening series, a large part of the 
 formations are excluded from the association with this most 
 important mineral. Do we find slates and shales, and 
 limestones, charged with bitumen, and burning on the fire, 
 this affords a presumption of some value, but it is not 
 decisive, as bitumen is associated with many minerals that 
 do not belong to coal formations. The impressions of 
 plants on the rocks, especially those charged with bitumen, 
 strengthen our presumption ; and should we find fragments 
 of coal scattered in the soil, or mingled with gravel and 
 sand, in the banks and water courses, and should we observe 
 dark masses of earth, (called by the miners coal blossoms,) 
 which, on close inspection, appear to contain fine coaly 
 matter, we may presume that beds of this combustible may 
 be near, and that it may be proper to dig or bore ; and 
 when, at last, we find the beds of coal, they will be regu- 
 larly arranged between roof and floor of rock, which is 
 commonly coal slate or shale. But it by no means follows 
 
 * The coal strata sometimes repose upon granite, (not in it,) as in 
 France, and near Richmond, Virginia. 
 
9 
 
 that beds of slate necessarily indicate coal : those of the 
 primary series would scarcely contain any combustible, 
 unless it were plumbago, or possibly a little anthracite. 
 The geological laws of coal are very strict, and a thorough 
 acquaintance with them is an effectual safeguard against 
 fruitless enterprises, productive only of expense and dis- 
 appointment. 
 
 Lignite. It is easy to mistake beds of lignite for coal : 
 lignite, when found in sufficient abundance, is a valuable 
 combustible, but it is not coal ; in burning it emits a sharp 
 and acrid odour, like the smoke of a wood fire, and is in fact 
 wood only altered by inhumation. It is mostly abundant 
 in the more recent geological formations, especially in ter- 
 tiary beds of sand, gravel, and clay, in which true coal is 
 never found. The trees that are buried in the more recent 
 alluvial or diluvial deposits are little altered, and are, for 
 the greater part, readily recognised as belonging to existing 
 species: but sometimes they are flattened by pressure, 
 altered in their texture,* and even partially carbonized. 
 
 Vegetable origin of coal. Coal is entirely of vege- 
 table origin : hundreds of species of plants have been 
 distinguished in the coal formation, but not one of 
 them is found at the present time living on the earth, 
 although many of the families do exist ; but their species 
 are generally of a diminutive size, in comparison with 
 those of the coal period ; and those modern ones that ap- 
 proach the ancient in magnitude, are found chiefly in 
 tropical climates. 
 
 Limestone and marbles. Limestone, including chalk 
 and marble, is a most useful substance. The ancient 
 Grecian temples give decisive proof of the durability of 
 marble ; and its beauty, even after the lapse of two or 
 three thousand years, and after innumerable aggressions 
 by the violence of war, or the depredations of antiquaries, 
 * Professor Carpenter, in the Am. Jour. vol. xxxv. No. 2. 
 
10 
 
 more destructive than the action of the elements, is not 
 entirely destroyed. Limestone is the most important in- 
 gredient in mortar, and is of great value in soils. But it 
 is not necessary to enlarge on a subject so generally under- 
 stood. It is sufficient to say, that in the selection of lime- 
 stone for architectural constructions, or to afford mortar or 
 a fertilizing ingredient for soils, geological skill will often 
 prove of great value ; and in cases of high responsibility, 
 such as those of grand public edifices, intended to endure 
 to distant ages, the united services of the geologist, the 
 quarry-man, and the stone-mason, may well be put in 
 requisition, for practical artists often acquire the skill to 
 judge very correctly of the value of materials. The ex- 
 perience of all antiquity proves this to be true. 
 
 Various rocks. The same view may be taken of granite 
 and sienite, and the slaty rocks of that family, of porphy- 
 ries, traps, and soapstones, of sandstones and pudding- 
 stones, or breccias. All these, and more, are employed 
 either in constructing the external walls, or in forming the 
 interior decorations of buildings, as well as in forts, docks, 
 bridges, quays, aqueducts, and roads, and it is of the 
 utmost importance that time and expense should not be 
 bestowed upon materials that are faulty or worthless ; for 
 sandstones, limestones, and even some kinds of granite 
 crumble down on exposure to the weather, and thus pro- 
 duce deformity and dilapidation, where every thing should 
 be solid and enduring. 
 
 Mode of detection. In general, this error may be 
 avoided by a careful observation of the effects of time and 
 the weather upon such masses of rocks as chance to be 
 prominent above the ground, and have therefore been (it 
 may be for ages) subjected to those atmospherical agencies, 
 which the finished edifice must, in its turn, encounter. 
 
 Instances of premature decay. Had these precautions 
 been observed, we need not at this moment see splendid 
 
11 
 
 aqueducts crumbling into ruins, before they are twenty 
 years old ; nor bricks splitting by the slacking of the lime, 
 that was burnt into quick lime, when the clay containing 
 it was baked, and thus ruining the walls of houses ; nor the 
 marble steps of a magnificent Grecian temple crumbling 
 at their edges and angles, because they are constructed of 
 feebly coherent dolomitic marble; nor the walls of the 
 grandest parliament house in the world painted with white 
 lead, to conceal the spots of iron rust developed by the 
 air upon a soft sandstone : such a building should have 
 been constructed of granite or white marble ; and happily 
 most of our cities are now able to present magnificent 
 edifices of these materials, upon which the storms and 
 floods of thirty centuries may beat in vain. 
 
 Gypsum. Plaster of Paris, (chemically, sulphate of 
 lime,) is of great value to the agriculturist, to the modeller, 
 and to the architect. One would think, that as it is used 
 by multitudes, it must be sufficiently known, and that a 
 little scientific knowledge would prevent the quarry-men 
 from throwing away as worthless, the pure crystallized 
 selenite,* and saving only the darker and coarser plaster. 
 Still, because this mineral is soft, every geologist is called 
 on to give his opinion upon various tender stones, supposed 
 to be plaster of Paris. The varieties of chlorite and 
 of chloritic slates, and of talc, soapstone, and steatitic 
 minerals, are most usually mistaken for plaster, and even 
 the limestones are sometimes confounded with it. In 
 the former instances, the labour of grinding is lost to 
 the farmer, as those minerals are not known to produce 
 any beneficial effect upon soils, but the case is not the 
 same with the latter, which may prove highly advan- 
 tageous, f A very moderate acquaintance with the charac- 
 ters of minerals would prevent these mistakes, so 
 
 As was done in the State of New York. 
 
 t As happened a few years since, at Genesco, State of New York. 
 
12 
 
 discouraging and injurious to rural industry ; and persons 
 unacquainted with mineralogj', should not incur the 
 hazard of time or property without first consulting those 
 who are qualified to judge. 
 
 Marls. Marls also are of great importance to agricul- 
 ture, and many barren tracts have been redeemed and 
 brought to fertility by a judicious use of these substances. 
 But as the earthy materials which bear the name of marl, 
 are often extremely similar in their aspect to clays, it is 
 important to distinguish them correctly, and this is done 
 by inspection, where there are visible fragments of shells, 
 and other animal remains. Usually, the calcareous matters 
 are so minutely divided and blended with the earthy 
 materials, that they cannot be detected by the eye, and we 
 must resort to chemical trials by acids or by fire. These 
 trials are easy r and decisive, and may save the practical 
 farmer from the double disappointment and vexation of 
 covering his land with that which is not only unprofitable, 
 but which may also be injurious to vegetable growth. 
 It may happen that a substance which is not marl may 
 prove useful, as when sand is mingled with clay, or clay 
 with sand; the former, to correct a soil too stiff and 
 tenacious, the latter, one that is too open and too little 
 retentive. It is, however, rare, that on a large scale 
 such mixtures can be made by art, without ruinous ex- 
 pense ; it may answer to prepare a soil for a garden, or 
 other grounds of limited extent, but in general, we can 
 only correct deficiencies; we cannot afford to make a 
 soil anew. 
 
 Metals. The researches for metals have ever interested 
 mankind in a high degree, and on no subject are they 
 more liable to error and imposition. 
 
 Iron. Happily, the most important metal is the most 
 abundant. But iron ores are not always known by the un- 
 instructed; some of the most valuable are not attracted by 
 
13 
 
 the magnet, until they have been heated in contact with 
 carbon or hydrogen ; while others are so completely dis- 
 guised, that they are not recognised at all by those ac- 
 quainted with the purified metal alone. This arises from 
 their combination with various substances, chiefly oxygen, 
 sulphur, acids, or arsenic, which, on account of the great 
 change they produce in the properties of metals, are called 
 mineralizers. Iron pyrites, an abundant mineral of little 
 value, is frequently mistaken for gold, because it is usually 
 yellow, and this, notwithstanding that it is hard and brittle, 
 while gold is soft and malleable. Yellow mica is gathered 
 for gold dust, and silvery mica and white arsenical iron are 
 taken for silver. 
 
 Calamine, the native oxide of zinc, and tin-stone, the 
 native oxide of tin, have no resemblance the former, to 
 any metal whatever, and the latter has none to tin, while 
 both might be rejected by an ignorant observer. The same 
 may be said of the sulphuret of silver, the grey sulphuret 
 of copper the chromate molybdate carbonate phos- 
 phate and sulphate of lead, and many more. Few 
 persons do, indeed, trust themselves to carry on great 
 works in mining, without previously consulting professional 
 men ; some are, however, so perverse, or blinded, as to 
 persist even against the best counsels, and they, of course, 
 pay the forfeit of their folly in disappointment, and some- 
 times in ruin. 
 
 Divining rod. Many more, however, yield themselves 
 both blind and willing dupes to the miserable delusions or 
 villany of the divining rod. Too often does it happen, 
 even now, that the professional man is consulted, not to 
 know whether the divining rod has any virtues, but to 
 ascertain how they may be best applied, to enrich the 
 credulous inquirer; and the geologist who can reply to 
 such persons with temper and kindness, does, indeed, no 
 more than his duty, although he might be pardoned for a 
 
14 
 
 sharp rebuke deserved certainly by the diviner, if not 
 by his convert. 
 
 Geological associations of metals. It is well known to 
 geologists, that metallic veins are rarely found in the most 
 recent formations and, with the exception of iron, and of 
 alluvial deposits of other metals, they rarely occur in 
 great abundance, until in the descending series we ap- 
 proach or pass the geological epoch of coal. In the 
 transition rocks, certain metals abound, while others fre- 
 quent the primary, and there is no rock so old that it may 
 not contain some of the metals. Sound scientific views of 
 the geological structure of a country will therefore serve 
 as an important guide in the research for metals, or in 
 lorming a conclusion as to the probable continuance, en- 
 largement, or cessation of metallic veins. 
 
 Decisions of science. The negative which science often 
 pronounces with entire confidence, may save many a san- 
 guine mind from delusion, and preserve for agriculture, and 
 the useful arts of life, the resources which might have been 
 lavished, in reckless profusion, upon vain and unproductive 
 mining operations. It is rare that metallic mines will 
 justify the abandonment of a useful calling, in the common 
 walks of life ; even where there is abundance of valuable 
 ore, few individuals can, alone, afford to encounter the 
 enormous expense of mining, and to wait its uncertain, 
 and it may be, distant and stinted returns. A good quarry 
 of soapstone, granite, gypsum, or sandstone, may be worth 
 more than a mine of gold, and such have actually been 
 the results in some signal cases in this country. To 
 these few instances of the importance of geological know- 
 ledge to the common interests of life, many more might 
 be added, but these are sufficient to illustrate our argument, 
 if, indeed, it be necessary to prove that he who acts with 
 consummate knowledge proceeds with safety walking in 
 the full and certain light of science j while he who adven- 
 
15 
 
 tures in the dark, has no right to expect anything but 
 disaster and ruin. 
 
 Geological surveys by public authority. That there is 
 some just appreciation of this subject among the people of 
 this country, is sufficiently evinced by the geological 
 surveys of many states and territories, either already ac- 
 complished, or in progress. About one half of the states 
 have, by public authority, instituted such surveys ; the 
 reports which have been published, evince industry, know- 
 ledge, and skill ; great progress has been made in develop- 
 ing the mineral resources of the country, and in amassing 
 stores of materials to serve for a future digested and syste- 
 matical account, both scientific and practical, of North 
 American geology; while, at the same time, excellent 
 schools are thus established, in which to form young 
 geologists by actual and responsible explorations among 
 mines and mountains. These good works will, we trust, 
 proceed, until our whole territory has been surveyed, 
 when some gifted individual will give us the grand result. 
 In a scientific relation, these researches are deeply inter- 
 esting, and we are in this way, as well as by personal 
 efforts, contributing our share of materials towards the 
 general stock of geological knowledge. 
 
 7. SOME FEATURES IN NoRTH AMERICAN GEOLOGY. 
 
 Perhaps no country is more favoured in the nature, abun- 
 dance, variety, and distribution of the most important 
 mineral treasures. The limits of these preliminary re- 
 marks must prevent even the most general summary of 
 our geological formations, or, at most, admit of nothing 
 more than a skeleton ; but the materials for information 
 are already abundant, and are yearly increasing, as may 
 be seen in the various public reports, in the transactions 
 of learned societies, and in the journals of science. 
 
 Of the primary and transition rocks, to which we may 
 add the coal formation and the early secondary, we have 
 
 
16 
 
 immense ranges, extending in a north-easterly and south- 
 westerly direction, through the continent, and comprising 
 most of the minerals and many of the fossils that are 
 found associated with such groups in the old world. 
 
 The Alleghanies, (including many mountains having local 
 names,) following the general bearing of N. E. and S.W., 
 and ranging between the Mississippi and the Atlantic, 
 form, with their branches and connected chains, the great 
 rain-shed of the countries east and west ; and rising to two, 
 three, four, and five thousand feet and more,* give direc- 
 tion to the streams and rivers, either to the Mississippi, 
 the Atlantic, or the great lakes and the St. Lawrence. 
 
 Rocky Mountains. In like manner, the far more stu- 
 pendous chains of the Rocky Mountains, whose loftiest 
 peaks are reported to be between three and five miles 
 high,f give a geological character to the regions east and 
 west, in which directions the waters flow to the Mississippi 
 and to the Pacific, while other contributions descend to the 
 Gulf of Mexico and to the Northern Ocean. It is to be 
 regretted, that in the United States proper, there are no 
 mountain ridges or solitary peaks that pierce the region 
 of perpetual snow. 
 
 Mount Washington. Mount Washington, of the White 
 Mountain group in New Hampshire, which approaches a 
 mile and a quarter in height, although in 44 of north lati- 
 tude, and on a continent whose average temperature is 
 many degrees below that of Europe, throws off its snowy 
 mantle only for a short season, in the months of July and 
 August, while it is clad in white during the remaining 
 months of the year. Even on the first day of September, 
 (1837,) as adventurers upon this Alpine mountain, \ we 
 
 * Professor Mitchell, University of Chapel Hill, states that the top of 
 Black Mountain, in North Carolina, is G47G feet above the level of the 
 ocean. See Am. Journal, vol. xxxv. No. 2. 
 
 t See Professor Renwick's Outlines of Geology.' 
 
 J 'See Am. Jour. Science, vol. xxxiv. p. 74. 
 
were, both on its flanks and summit, involved in a wintry 
 tempest of congealed vapour, formed into splendid groups 
 of feathery and branching crystals, unlike to the snows of 
 the lower regions ; the driving masses came in fitful gusts, 
 veiling in a white cloud all objects, far and near; but 
 breaking occasionally to admit a flood of solar light to 
 render visible this hoary pinnacle, and the deep gorges and 
 valleys of the neighbouring groups of mountains. The 
 mountains of Essex county, State of New York, between 
 Lake Champlain and the St. Lawrence, approach the 
 White Mountains in altitude, but no one of them is per- 
 manently snow-clad. 
 
 Mountains of central Europe. It is otherwise in Europe, 
 whose grand central group, of Mount Blanc, and the 
 various Alpine mountains, rise far into the region of per- 
 petual congelation ; and Mount Blanc would pierce that 
 region even at the equator. Thus is provided an eternal 
 storehouse of ice and snow, over whose wintry surface the 
 winds, rendered heavier by contact, glide into the valleys 
 and plains of the countries at their feet, and thus temper 
 even the warm climate of Italy, preventing the extreme 
 vicissitudes which we experience. 
 
 But these immense natural magazines have a still more 
 important relation to the irrigation of the vicinal countries. 
 The melting by the heat of summer, supplies copious 
 streams to feed the innumerable rivers that flow from these 
 grand fountains, to almost every part of continental Europe, 
 south of the Baltic. Thus, the effects of drought are, in a 
 great measure, prevented, while destructive mountain- 
 floods are of rare occurrence. From the absence of such 
 mountains, we have no permanent stores of ice and snow, 
 and, consequently, our rivers are liable to extreme varia- 
 tions of altitude and force. The Ohio, in midsummer, 
 sometimes leaves numerous fleets aground, while occa- 
 sional risings, from deluging rains, aided perhaps by the 
 
18 
 
 melting of the snows of vast regions, swell the river to an 
 immense flood, that spurns the barrier of the banks, lays 
 villages and cities under water, and, expanding into an 
 internal sea, rushes with wasting violence over the wide- 
 spread meadows and farms. For this reason, hydraulic 
 engineering is, in this country, attended with peculiar diffi- 
 culties, both on account of a deficiency and an excess of 
 water; the former rendering the works inoperative, and 
 the latter invading or sweeping them away. The future 
 civilized inhabitants of the countries near the Rocky Moun- 
 tains, (excepting, of course, the immense sandy deserts, 
 which, near the eastern slope, emulate the sterility of 
 Arabia and Zahara,) will enjoy advantages in many re- 
 spects similar to those of Piedmont, Switzerland, Germany, 
 and France ; and it is easy to predict, that peculiar struc- 
 tures, and a peculiar state of society, will be modelled upon 
 the sublime physical features of those truly Alpine regions. 
 From this, his native land, we have too much reason to 
 expect, that, despite of the efforts of the benevolent to 
 avert the impending doom } the red man of the forest, not 
 reclaimed to humanity, but abandoned to his fate, will 
 vanish before the prevailing arts and power, and the still 
 more prevailing seductions, of civilized life the extermi- 
 nated victim of cupidity and cruelty. 
 
 Influence of geological structure on society. It is per- 
 fectly apparent to geologists, that the scenery of a country 
 is not more exactly stamped by its geological formations, 
 than are the manners and employments of its inhabitants. 
 This argument, so beautifully displayed by Dr. Buckland,* 
 with respect to England, is capable of an equally satisfac- 
 tory application to this country. 
 
 New England. The bleak hills and long winters of New 
 England are unfavourable to the most extensive and profit- 
 able agricultural pursuits, while the extensive and deeply 
 * Bridge\vater Treatise. 
 
10 
 
 indented sea-coasts, abounding with harbours, headlands, 
 rivers, and inlets, naturally produce an impulse towards 
 the ocean, which, conspiring with the original adventurous 
 character of the population, sends them roving from the 
 arctic to the antarctic circle, till the wide world is laid 
 under contribution by their enterprise. Their numerous 
 streams and waterfalls furnish the cheapest means for 
 moving machinery, and thus manufactories spring up 
 wherever, in their expressive phraseology, there is water- 
 power ; and steam supplies local deficiencies of moving 
 force. Ingenuity, conspiring with a general system of 
 education, is excited, under such culture, to produce nume- 
 rous inventions, and hosts of young men seek their for- 
 tunes successively abroad, as mechanics seamen traders 
 instructors and politicians, who thus operate powerfully 
 and, we trust, beneficially on other communities. 
 
 Southern states. The immense tracts of rich alluvium 
 in the southern states the mildness of the climate the 
 coasts, less abounding with safe inlets, and often modified 
 by the action of the existing ocean, with a population not 
 originally commercial, give a decided impulse to agri- 
 culture, and a few great staples form the chief reliance 
 of the landholders. It is easy to see that this state of 
 things grows out of the recent secondary, the tertiary, and 
 the alluvial formations, which constitute the ocean-barrier, 
 from Staten Island to Florida, and from Florida to Texas, 
 extending inland toward the mountains. 
 
 Western states. In the west, the boundless fertile 
 prairies, and other tracts of productive soil, conspire with 
 remoteness from the ocean to indicate agriculture and 
 pasturage as the main employment of the inhabitants, while 
 exhaustless beds of coal, limestone, plaster of Paris, and 
 iron, and rich deposits of lead and copper, and salt foun- 
 tains, both numerous and copious, furnish means for a 
 manufacturing, as well as an agricultural population. 
 c2 
 
20 
 
 These pursuits occupy the greater number of the people, 
 while many find a profitable employment in navigating 
 those immense inland seas the great lakes and the vast 
 rivers, which run thousands of miles before they mingle 
 with the ocean. 
 
 What geologist fails to perceive that this state of things 
 is the result of the immense lower secondary and transition 
 formations which cover the western states, sustaining por- 
 tions of tertiary, and like all countries, alluvial depositions ? 
 While New England produces granite, marble, and other 
 building materials, of excellent quality, Pennsylvania, with 
 the western, and several of the southern and south-western 
 states, supplies inexhaustible magazines of coal, to prompt 
 and sustain the manufacturing interests of this wide coun- 
 try, and to aid its astonishing navigation by steam, already 
 of unexampled extent, on its internal waters, and destined, 
 at no distant day, to compete on the main ocean in ami- 
 cable rivalry with our parent country. 
 
 Geological treasures. Our coal formations, in richness 
 and extent, are unrivalled in the whole world ; our iron and 
 lead are in the greatest abundance and excellence ; Missouri 
 has mountains of pure oxide of iron, that have no compeers ; 
 and there is a fair prospect that copper will also abound in 
 the west. We have great deposits of limestone and marble, 
 of plaster of Paris, marl, and salt, and of building stones, of 
 almost every kind ; our soils are so various in quality, and 
 in geographical position, that almost every agricultural pro- 
 duction is obtained in abundance. It is obvious, then, 
 that we have all the physical elements of national and 
 individual prosperity, and that the blame will be our own, 
 if we do not follow them up by proper moral and intellec- 
 tual culture, which, alone, can render them sources of 
 public and private happiness. 
 
 Geological deficiencies upper secondary. Of the upper 
 secondary, below the chalk, and above the new red sand- 
 
'21 
 
 stone, lying higher than the coal, we have no well ascer- 
 tained strata : rocks of oolitic Structure we may have, but 
 it is not ascertained that we have the true oolite of 
 England and continental Europe, nor have we traced the 
 wealden nor the lias,* with their colossal animal wonders. 
 
 Equivalent of chalk. Chalk, properly speaking, appears 
 to be absent from the United States, but there is an equi- 
 valent to the chalk formation, containing similar fossils, 
 between the Delaware River and the shores of New Jersey, 
 as well as in various places in the south, and, as we are 
 recently assured, in Missouri.f 
 
 Absence of volcanoes. The principal deficiencies in the 
 geological formations of the United States, are in the 
 absence of active volcanoes, and of most of the members 
 of the upper secondary. However delightful active vol- 
 canoes, with their earthquakes and eruptions, may be to 
 speculative geologists, the sober, unscientific population, 
 may well rest quite contented without them, satisfied to 
 barter the sublime and terrific, for quiet and safety. Al- 
 though the soils formed from decomposed lava are often 
 amazingly fertile, and the vine flourishes on the flanks, and 
 at the feet of volcanic mountains of warm countries, these 
 influences are too local to be of much importance to agri- 
 culture. 
 
 Within the United States proper, including the states 
 and territories beyond the Mississippi, and east of the 
 Alleghany mountains, there is not, so far as we know, a 
 single active volcano, nor even an unequivocal crater of 
 one that is dormant. It remains yet to be decided, 
 whether in and beyond the Rocky Mountains, quite to the 
 shores of the Pacific Ocean, there are any active volcanoes 
 within our parallels of latitude. 
 
 * It is plain that the lias, so called ia the west, is not the lias of 
 England. 
 
 t See Dr. Morton's Synopsis of Organic Remains of the Green Sands of 
 the United States, 1 vol. 8vo. with plates. 
 
22 
 
 Both north and south of our limits, there are, on the 
 Pacific shores and the islands, numerous volcanoes, and it 
 would be strange indeed if there were none within our 
 extensive possessions on the same coasts. 
 
 Records of igneous action in the far West. However this 
 may be, there remains no doubt that the volcano has done 
 its work, on a great scale, among the Rocky Mountains, and 
 between them and the Pacific ; for all our travellers attest 
 the existence of immense regions covered with scoriae and 
 other decidedly igneous products, as if there had been 
 actual and vast eruptions within a period too short for 
 decomposition to have reduced these tumefied and semi- 
 vitrified masses to soil. 
 
 Trap and basalt. Regular formations of trap and of 
 basalt, with symmetrical columns, are common among and 
 beyond the Rocky Mountains, and the rocks of this igneous 
 family are frequent in many parts of the old United States. 
 They abound in New England, New Jersey, and the 
 Carolinas, and, as usual elsewhere, they protrude their 
 dykes among other rocks. We are not aware that they 
 have invaded tne coal, as in Europe ; but in New England, 
 and especially in New Hampshire, they often divide the 
 primary rocks, cutting even granite mountains from top to 
 bottom ; branching ,. rft, in many places, with numerous 
 veins, either dying away to extinction, or, perchance, re- 
 turning again to the main current after having cut off a 
 portion of the invaded rock. The White Mountains of 
 New Hampshire abound with such features. 
 
 Phenomena of a like nature are found in the mountains 
 of Essex, Lake Champlain, New York, and in many other 
 places ; and the primary rocks on the coasts of Massachu- 
 setts and Maine, as well as in the interior, are wonderfully 
 cut up, by invading veins and dykes of trap, basalt, and 
 porphyry, and even of granite itself. It appears, also, 
 that in the state of New York there are similar intrusions 
 

 23 
 
 into other rocks, including the primary, and not excepting 
 granite.* 
 
 Tertiary formations. Our tertiary formations are ex- 
 ceedingly extensive, and are rich in fossils, chiefly of the 
 earlier eras. They bound a large portion of the sea coasts 
 south of New England, quite to the Mexican Gulf, and up 
 the Mississippi and Missouri: these oceanic deposits are 
 found, also, extending hundreds of miles into the interior 
 from the coasts, where, as well as near the sea, they furnish, 
 in the calcareous marls, inexhaustible resources for agri- 
 culture. Even on the shores of New England, there are 
 marine tertiary deposits, as at Gay Head, in Martha's 
 Vineyard, and elsewhere in that vicinity, while there are, 
 in every part of the United States, innumerable inland 
 deposits of fresh water tertiary. 
 
 Boulders. In boulders and rocks of transport our 
 country abounds ; vast regions of older secondary, and of 
 transition, are occupied, more or less, by ruins of primary 
 rocks, some of them of vast size, while the primary 
 countries themselves, and the transition too, are marked 
 by their own disjecta membra. We are precluded by our 
 limits from discussing the causes of their transportation, 
 whether by floods, ice floes, or other motive powers. 
 
 It is almost unnecessary to remark, that pebbles, gravel, 
 and sand, are found, as in other countries, transported and 
 arranged, without doubt, by the action of water. 
 
 8. BEAUTY AND INTEREST OF GEOLOGY AS A SCIENCE. 
 In relation to the beauty and interest of geology as a 
 science, we can hardly trust ourselves to write, since, 
 within our prescribed limits, we have no room, as there is 
 little occasion to describe adequately that which our author 
 has, everywhere, treated with signal ability and interest. 
 It may, however, serve to engage the attention of those to 
 whom geology is a terra incognita, if we, in this place, 
 
 * See Professor Hall, in the Geological Reports for 1838. 
 
24 
 
 remark, that no field of science presents more gratifying, 
 astonishing, and (but for the evidence) incredible results. 
 Man has been but a few thousand years a tenant of this 
 world; nothing which we discover in the structure of the 
 earth, would lead us to infer that he existed at a period 
 more remote than that assigned to him by the Scriptures. 
 Had he been cotemporary with the animals and plants of 
 early geological periods, we should have found his remains 
 and his works entombed along with them. 
 
 Opinion of Berkeley. This argument forcibly impressed 
 the mind of Bishop Berkeley, a century ago, and the follow- 
 ing beautiful passage from his works is cited by Mr. Lyell.* 
 " To any one who considers that on digging into the earth, 
 such quantities of shells, and in some places, bones and 
 horns of animals, are found sound and entire, after having 
 lain there, in all probability, some thousands of years ; it 
 would seem probable that gems, medals, and implements 
 in metal or stone, might have lasted entire, buried under 
 ground forty or fifty thousand years, if the world had been 
 so old. How comes it then to pass that no remains are 
 found, no antiquities, of those numerous ages preceding the 
 scripture accounts of time ; that no fragments of buildings, 
 no public monuments, no intaglios, cameos, statues, basso- 
 relievos, medals, inscriptions, utensils, or artificial works of 
 any kind, are ever discovered, w r hich may bear testimony 
 to the existence of those mighty empires, those successions 
 of monarchs, heroes, and demi-gods, for so many thousand 
 years? Let us look forward, and suppose ten or twenty 
 thousand years to come, during which time we will sup- 
 pose that plagues, famine, wars, and earthquakes, shall 
 have made great havoc in the world, is it not highly 
 probable, that at the end of such a period, pillars, vases, 
 and statues, now in being, of granite, or porphyry, or 
 jasper, (stones of such hardness as we know them to have 
 * Principles, 5th Ed., vol. iii. p. 255. 
 
25 
 
 lasted two thousand years above ground, without any con- 
 siderable alteration,) would bear record of these and past 
 ages ? or that some of our current coins might then be 
 dug up, or old walls, and the foundations of buildings, 
 show themselves, as well as the shells and stones of the 
 primeval world, which are preserved down to our times."* 
 This remarkable passage proves that the great man from 
 whom it^ fell, saw the geological argument in a true light, 
 and felt its force to such a degree as to convince him of the 
 great antiquity of the earth, which he justly viewed as in 
 no way inconsistent with the comparatively recent origin 
 of man, or with the historical account of both events con- 
 tained in the Genesis. It is easy to understand how such 
 a mind would have been convinced, warmed, and excited 
 even to enthusiasm, by the discoveries that have burst 
 upon us during the last fifty years. 
 
 9. ORGANIC REMAINS. We descend from the alluvial 
 under our feet, through the strata, the lowest of which lies 
 upon the granite, or the early slates, and we are seldom with- 
 out the records of life, in ages long past, and those records 
 are drawn both from the animal and vegetable kingdom. 
 
 Ancient animals. Shells and molluscous and testaceous 
 animals are everywhere seen ; their forms, their casts, their 
 substance, are apparently preserved in stone, but really 
 converted, by the substitution of mineral matter, into true 
 fossils. Myriads on myriads of these things are found, not 
 merely in the visible, superficial strata, but in the heart of 
 the mountains, and at profound depths, forming an essen- 
 tial part of the solid framework of the globe. The animals 
 and plants are not accidental resemblances, but authentic 
 specimens of organic antiquity, inclosed in the strata and 
 mountains, as the materials, in mechanical or chemical 
 suspension in the waters, concreted around them. It was 
 impossible that they should be due to any sudden or acci- 
 
 * Alciphron, or the Minute Philosopher, vol. ii. pp. 84, 85. 1732. 
 
dental event ; the organic beings came into life as now 
 performed their parts as now, and were entombed in the 
 forming masses, which were, therefore, of more recent origin. 
 
 Fossil fishes. If we descend ;with Agassiz * from the 
 strata of newest formation, to those that lie near, or upon 
 the primary rocks, we are astonished and delighted to find 
 not only that crustaceous and molluscous animals, of various 
 kinds, have existed in the early ages, but that fishes have 
 also occupied the waters of almost all geological ages, since 
 life began ; and that among the earliest, even those that are 
 buried beneath the coal, there were races of great size, 
 power, and ferocity; formidable from their teeth and jaws, 
 which had, in some species, the structure of carnivorous 
 reptiles, and whose forked tails, with unequal flukes, en- 
 abled them quickly to turn over on their backs before 
 striking their prey. The fossil fishes, of particular genera 
 and species, are characteristic of particular geological form- 
 ations ; they extend geographically, far and wide, to distant 
 countries, so that certain species may, if found at all, be 
 expected in similar rocks in Europe, in America, in Asia, 
 and Africa, and they are of every size, from inches, and 
 fractions of an inch, to several feet. They occur either 
 solitary or in groups or in fragments or in immense 
 shoals, like those of Mount Bolca, near Verona, in Italy, 
 where there are more than one hundred species ; still not 
 a single fish of the strata that [precede the most recent ter- 
 tiary, is identical in species with any now existing in the 
 waters of the globe. 
 
 Fossil vegetables. Vegetables are found in nearly all 
 geological ages, and the labours of Count Sternberg, of M. 
 Adolphe Brongniart, and others, have proved that a pecu- 
 liar vegetation, adapted to the temperature, the degree of 
 moisture, and other circumstances of the earth's successive 
 surfaces, attended the different geological epochs. 
 
 * The great writer oil fossil ichthyology, of Neufchatel. 
 
27 
 
 Splendid and expensive works are now in the hands of 
 geologists, containing exact delineations of the fossil vege- 
 tables, so far as they have been ascertained. They are of 
 all dimensions, from minute confervae and lichens, to 
 gigantic trees; their structure, from mere fragments and 
 ruins, to perfect plants and trees, has been beautifully 
 displayed roots, trunks, branches and leaves, with the 
 most delicate ramifications of the skeletons of the latter; 
 in some rare cases, the more perishable organic fructifica- 
 tion has been made out, and the fruits themselves have 
 been identified. 
 
 Vegetation of the coal period. The most exuberant 
 vegetation appears to have been that of the coal period, 
 and its entombed treasures now supply the world with fuel, 
 especially in countries where the forests are exhausted, or 
 where economy of the modern vegetation, or preference for 
 the results of the ancient, decides the choice. 
 
 Varieties of the ancient fossil vegetation. The ancient 
 vegetation appears in many forms, as in that of lignite of 
 coal, and of silicious, calcareous, and ferruginous petrifac- 
 tions, still preserving the peculiar structure ; and this has 
 been made still more distinct and satisfactory, by cutting 
 slices of the petrified trunks, and grinding them down 
 until they become so thin as to be transparent, when the 
 microscope reveals the internal arrangement of the pores 
 and fibres, which characterises the family. Thus, it has 
 been made to appear that various species of coniferous trees 
 preceded the coal formation in the south of Scotland, and 
 the north of England, and that zamias, and other palm-like 
 trees, preceded the chalk in the south of England. No 
 species of the ancient world is identical with any one of 
 the modern, and, as has been already remarked, the early 
 vegetation implies, generally, a warm and moist climate, 
 and great fertility of production. 
 
 stquatic animals reptiles. Animals, almost exclu- 
 
sively marine, attest the great prevalence of the ocean in 
 the earlier geological periods, and it is not until we have 
 passed the coal in the ascending order, that we begin to 
 find reptiles of marine or of amphibious families, and 
 ultimately, still higher up, of terrestrial races. With 
 a similarity of type to the families of the present day, 
 both their genera and species are, however, without a 
 single perfect copy in modern times. Some were carni- 
 vorous, and swam in the shallow seas, estuaries, lagoons, 
 and bays, and preyed upon fishes, molluscous animals, and 
 each other; some lived on land, and were herbivorous; and 
 although a few species, the megalosaurus and iguanodon, 
 for example, were colossal in size, and terrible in form, it 
 is probable that the latter of these terrestrial saurians was 
 harmless and inoffensive, while the tooth of the megalo- 
 saurus would indicate a ferocious animal of prey, like the 
 marine saurians. Bones of many genera and species of 
 the reptile tribes, especially the saurians, have been found, 
 and of some individuals, entire, or nearly perfect 
 skeletons; among them, those of vast dimensions have 
 been discovered, inclosed in the solid rocks, along 
 with their petrified and half-digested food, and with their 
 coprolites. 
 
 Marsupial animals. If the reptiles formed the transition 
 from the marine animals upward the marsupials, as they 
 are called, were the link between the ancient reptiles and 
 terrestrial quadrupeds. The marsupials, of which the 
 opossum is an example, receive their young (which, 
 although born, are still only immature) into an exterior 
 pouch, or abdominal sack, and there nourish them at their 
 paps, until they are fitted to go abroad, and to encounter the 
 vicissitudes of their peculiar modes of life. These are the 
 only animals hitherto found below the chalk which ap- 
 proximate to the proper terrestrial character. Dr. Mantell 
 has, however, found the bones of birds, in the wealden 
 
29 
 
 beneath the chalk; and Prof. Hitchcock has discovered 
 numerous tracts of animals, believed to be those of birds, 
 and perhaps of reptiles, some of them of gigantic dimen- 
 sions, in the new red sandstone of the Connecticut River. 
 
 Fossils of the chalk and tertiary. The chalk follows, 
 with its immense and varied marine treasures ; and next 
 the lower tertiary, still marine, succeeded by the middle 
 tertiary, where proper and fully characterised terrestrial 
 animals are first found. Through the remaining beds of 
 tertiary, both marine and fresh water, we find molluscous 
 animals, fishes, reptiles, and vegetables, verging towards, 
 and even identical with those of our own times ; and occa- 
 sionally we discover also terrestrial animals, but still different 
 from the modern, until, at last, in the diluvium and allu- 
 vium, and the most recent sedimentary and concretionary 
 formations, we discern animals and plants still more and 
 more like those now living, and finally graduating into 
 perfect identity with existing races. 
 
 Man nowhere fossil. Man and his works appear only 
 in the last stages, associated with the remains of just such 
 beings as now exist, both in the animal and vegetable 
 world. The pages of our author will disclose the great 
 variety and extraordinary form, and, in many cases, colossal 
 dimensions, unrivalled at the present time, of some of the 
 ancient animals, the megatherium, sivatherium, dinothe- 
 rium, mastodon, elephant, hippopotamus, rhinoceros, the 
 cavern bear, tiger, and many others. In consequence of 
 the most recent discoveries of geology, we are hurried from 
 that which is stupendous and vast, to that which is incon- 
 ceivably minute. The extremes of creation meet in the 
 mineral kingdom. In the solid rocks are found both the 
 colossal reptiles, and the microscopic infusorial animalculae. 
 Ehrenberg has discovered that polishing slate is made up 
 of animalculae so minute, that forty-one thousand millions 
 of them are required to fill a cubic inch, in every grain of 
 
30 
 
 which there are one hundred and eighty-seven millions, 
 and their silicious shields are the cause of the well-known 
 effect of the tripoli, or rotten stone, in polishing steel, &c. 
 An analogous constitution has been discovered in flint, 
 opal, and bog-iron, and the deposits of our modern peat 
 bogs in this country, are filled with similar animalcules, 
 the figures of some of which have been given by Prof. 
 Baily, in the American Journal of Science, vol. xxxv. 
 p. 118. 
 
 10. GENERAL REMARKS. Such is an exceedingly gene- 
 ral and very imperfect sketch of the progressive creation 
 of animals and plants ; that have inhabited our world have 
 become extinct, and are, in countless myriads, entombed in 
 the rocky strata, and in the solid mountains. It is only on 
 the upper surface that we discover loose and scattered ruins, 
 either in the soil, or buried in the masses of gravel, sand, 
 and clay; ruins of rocks, and fragments of strata, along 
 with the relics of animals, trees, and other superficial de- 
 posits, such as we could in any reason attribute to the 
 catastrophe, or catastrophes, of rising and rushing water, 
 the deluges of geologists, or the deluge of the Scriptures; 
 the latter, almost alone, being admitted to the contempla- 
 tions of those who are uninstructed in our science. Now, 
 it is a matter of physical demonstration, that the earth 
 existed for many ages before man was called into being. 
 The whole course of geological investigation proves this 
 view to be the only one that ia consistent with the facts. 
 To be convinced of its truth, it is only necessary to become 
 thoroughly acquainted with the records of a progressive 
 creation and destruction which the earth contains, inscribed 
 on medals, more replete with historical truth, and more 
 worthy of confidence, than those that have been formed by 
 man ; as much more as nature exceeds in veracity the 
 erring or mendacious records of the human race. 
 
 11. CONSISTENCY OF GEOLOGY WITH THE SCRIPTURE 
 
31 
 
 HISTORY. Hardly two centuries have passed since the 
 astronomy of Galileo, Kepler, and Newton, was regarded 
 as inconsistent with the Scriptures, and therefore heretical; 
 and although the discrepancy of the literal meaning of the 
 Bible with the real truths of astronomy, is still as great as 
 ever, no one any longer hesitates to regard astronomy as 
 giving a just view of the stupendous mechanism of the 
 heavens ; all agree in understanding the language of the 
 Scriptures as being adapted to the appearances of the hea- 
 vens, of which alone mankind in general can form any 
 just conception, and with which alone the Scriptures are 
 concerned. The Bible being designed as a code of moral 
 instruction, as a revelation of a future life, and of the 
 sanctions that belong to that momentous subject, contains 
 no systems of science. Moral science, essentially con- 
 tained in the Scriptures, is not, even there, presented in a 
 regular form, as in human systems, but in modes more 
 happily adapted to the actual condition and capabilities of 
 mankind. 
 
 In relation to physics, the information contained in the 
 Bible is only incidental. God is declared to be the Creator 
 of the heavens and the earth, the physical universe, 
 and throughout the sacred volume, there are innumerable 
 allusions to, and illustrations of his character, as its Creator 
 and Governor, but there is not even the most general out- 
 line of any physical science ; the creation of the heavens 
 and the earth, of the sun and the moon, being disposed of 
 with extreme brevity, while the allusions to the geological 
 arrangements of this planet are only such as are connected 
 with the first appearance of its organized beings, and the 
 emergence of the land from the original ocean. 
 
 Instruction in the sciences was not the object of the 
 Scriptures : the physical creation was left by the Divine 
 Author for the delightful exercise of our faculties, an inex- 
 haustible source of mental and moral pleasure ; for appli- 
 
32 
 
 cation to use, to increase me power and the comforts of 
 man ; for the additional illustration of the character of God, 
 and also for an exhaustless fountain, whose streams mingle 
 harmoniously with those of divine revelation. 
 
 From the study of the physical creation, man has there- 
 fore drawn all the physical sciences, of which astronomy 
 is the most sublime and splendid, while geology yields, in 
 this respect, only to astronomy. Neither astronomy nor 
 geology is, however, taught in the Scriptures, but both 
 are contained in nature, and their astonishing truths have 
 been brought to light by human research. 
 
 While, as already remarked, astronomy is, in fact, incon- 
 sistent with the apparent movements in the heavens, and, 
 therefore, with the literal and popular phraseology of the 
 Scriptures, which allude to physical things as they appear, 
 and not as they are in reality, geology presents not even 
 a literal discrepancy, but, on the contrary, a substantial 
 agreement in its facts with the Scriptures : the latter de- 
 scribe a physical creation of mineral matter, and a succes- 
 sive creation of plants and animals, ending with man, while 
 geology, by irrefragable demonstrations,* which nothing but 
 a study of the earth could afford, proves this history to be 
 true. The Scriptures describe a universal deluge, and 
 geology proves that every part of the earth is marked by 
 the effect of such visitations, occurring at one time, or at 
 many times ; a repetition of local deluges, or a general 
 one, would produce similar results ; and although it may 
 be impossible to distinguish between the accumulated 
 effects of local overflows, and a general diluvial devasta- 
 tion, the surface of the earth abounds with diluvial ruins. 
 The Scriptures declare that there was a beginning, and 
 geology proves that there was a time when plants, and 
 animals, and man, did not exist ; both the Scriptures and 
 
 * See Dr. Buckland's Bridgewater Treatise, an admirable and per- 
 fectly conclusive moral and physical demonstration. 
 
 
geology arc silent as to the period when the fiat of the 
 Creator called our earth and the planetary systems into 
 being. It was, doubtless, in very remote antiquity, but the 
 beginning is known only to Him who has neither beginning 
 of years nor ending of days. 
 
 Having elsewhere discussed the question of the duration 
 of the days,* and of the creation, we shall not here reite- 
 rate those arguments, satisfied that the date of the begin- 
 ning is not recorded either in nature or in revelation, and 
 may extend back to any period, however long, which phy- 
 sical truth may demand. On the other hand, the moral 
 dispensations of God to our world, necessarily begin with 
 man, and the account of him which is contained in the 
 Bible is fully confirmed by his uniform character, as 
 exhibited by all tradition and history. While, therefore, 
 geology proves that our world existed for many ages before 
 man was created, and that his creation was only the last 
 act in the series, it perfectly concurs in the conclusion that 
 the human race cannot have been on the earth more than 
 a few thousand years. Where then is the discrepancy 
 between geology and the sacred history, and what is the 
 cause that this science fills many minds with alarm, and 
 not a few with hostility? As the result of no short or 
 superficial study, or light contemplation, we aver, with 
 perfect confidence, that the alarm is without cause the 
 hostility without justification ; and equally baseless are the 
 hopes of those who would draw from geology, weapons 
 with which to assail the Scriptures. This science, like 
 her elder sister, astronomy, is the ally, and not the enemy 
 of revealed truth. The consistency of geology with 
 the Scripture history, is susceptible of a perfect and 
 triumphant defence, but it is not found in the refinements 
 of exegesis, nor in the forced solution of a general deluge, 
 
 * Appendix to the second and third American editions of Bakewell's 
 Geology. 
 
 d 
 
34 
 
 entirely unsatisfactory, and indeed impossible, as a cause 
 of the regular formations of the earth, immensely 
 varied as they are, and exuberant in the relics of many 
 successive races of the animals and vegetables of past ages. 
 But this consistency is found in the regular induction from 
 facts, in the just understanding of time, and in its exten- 
 sion back beyond the creation of man, so far as to cover 
 the innumerable events that have certainly happened. 
 To this conclusion the religious world is fast approaching ; 
 its arrival at the goal of truth is as certain as the progress 
 of time, and the period is near at hand when the great 
 deductions of geology, like those of astronomy, will be 
 viewed as in perfect harmony with the Scriptures, and as 
 highly illustrative of the character of the great, glorious, 
 and beneficent Being, who in the beginning created the 
 heavens and the earth. The time has already come, when 
 those who claim to judge of the consistency of the Scrip- 
 tures with geology, must study this science, not superficially, 
 but profoundly ; for in no other way can they become 
 qualified to form a just opinion in the case. It is, indeed, 
 lamentable to observe the crude and absurd speculations 
 of some, who speak and write in a manner adapted only 
 to expose their own entire ignorance of the subject ; and 
 there are not wanting those, both at home and abroad, 
 whose arrogance and censoriousness are exhibited in a 
 manner equally uncandid and undignified ; while their 
 incredulity, manifested by a blind rejection of evidence 
 without examination, (a real infidelity,) would imply, that 
 the Author of nature has given a revelation inconsistent 
 with the work of his own hands. We regard with kind- 
 ness and forbearance those whose honest fears, tempered 
 by a spirit of candour, would be removed by an accurate 
 knowledge of geological facts, but geologists have a right 
 to claim that critics, whose decisions are made without 
 any adequate examination of the science, shall abstain from 
 
imputations on those who faithfully study and report th 
 actual structure of the earth, and who reason upon the 
 facts according to the soundest principles of logical and 
 philosophical induction. Geologists do not, in turn, invade 
 the domain of criticism, nor is there the least occasion to 
 do so ; for they receive language in its usual acceptation, 
 and as it is expounded hy those who are the hest qualified 
 to judge ; still, they assume the liberty to understand it in 
 consistency with the subject to which it is applied in 
 consistency with the truths of nature, which are as irre- 
 fragable as those of revelation, for they proceed from the 
 same Author, and are incapable of perversion. In the 
 beautiful language of Professor Sedgwick " No opinion 
 can be heretical but that which is not true. Truths can 
 never war against each other. We have nothing to fear 
 from the results of our inquiries, provided they be followed 
 in the laborious, but secure road of honest induction. In 
 tins way we may rest assured, we shall never arrive at 
 conclusions opposed to any truth, either physical or moral, 
 from whatever source this truth may be derived ; nay 
 rather that new discoveries will ever lend support and 
 illustration to things which are already known, by giving 
 a larger insight into the universal harmonies of nature."* 
 It is most unwise then to reject truth, for which science 
 is indeed but another name, and it is quite certain that 
 the friends of revelation, and the friends of science, may 
 walk harmoniously together, for they are cultivating only 
 different departments of the same great field ; the fruits 
 which they gather may be safely stored in the same 
 garner, and in all coming ages, will be wisely regarded as 
 treasures of inappreciable value. 
 
 12. NOTICE OF THIS WORK AND ITS AUTHOR. /We shall 
 conclude by an immediate reference to the work before us, 
 satis-lied if our remarks shall serve to draw attention to 
 * Address to the London Geological Society, Feb. 19, 1830. 
 
36 
 
 these beautiful and instructive lectures, and to their dis- 
 tinguished author. 
 
 Dr. Mantell's earlier publications, among which were 
 " Illustrations of the Geology of Sussex," 4to ; also a work 
 on the "Fossils of Tilgate Forest," 4to, and "The Geo- 
 logy of the South-east of England," 8vo ; all with nume- 
 rous plates and cuts, and many memoirs and tracts, appeared 
 when the author resided in his native town of Lewes, 
 seven miles from Brighton. By his great industry and 
 zeal, he redeemed from the cares of an extensive and 
 laborious medical practice, time to produce these fine works, 
 which rank with the very first on the science of geology, and 
 have raised the reputation of their author to a high standard. 
 Dr. Mantell, during his residence at Lewes, collected a 
 splendid, and in a great measure unique museum of organic 
 remains, the most remarkable of which were, the astonish- 
 ing bones and other reliquiae of his own region, discovered 
 entirely by himself, f 
 
 A few years since, he removed to Brighton, and there 
 established his museum in an appropriate mansion. It 
 soon became the nucleus for a Sussex Scientific and Literary 
 Institution, and in its rooms were held instructive and 
 entertaining conversaziones. On these occasions, and in 
 connexion with the museum, many interesting objects of 
 nature and art were exhibited and described by Dr. Man- 
 tell and his friends, to the fashionable and noble crowd 
 which revolve around the British court, during its tem- 
 porary pilgrimage to this favourite spot on the chalky 
 shores of Albion. J 
 
 Here Dr. Mantell yielded to the wishes of his friends 
 and the public, by giving occasional lectures on the 
 
 * la Sussex, Eugland; 50 miles from London. 
 
 t See American Journal of Science; vol. xxiii. p. 162; and Descriptive 
 Catalogue of the Mantellian Museum, 8vo. with plates. 
 I Fifty-five miles south-east of London, on the Channel coat>t. 
 
37 
 
 subjects which he had so successfully cultivated. Those 
 who had read his various works, in which science, genius, 
 and taste, were warmed by a noble, but disciplined and 
 sustained enthusiasm, were gratified to find that his powers 
 as a public speaker were commensurate with his high 
 attainments as an original investigator, and with his repu- 
 tation as a man of science, and of intellectual vigour. His 
 success in this character was fully equal to his previous 
 reputation. In consequence, he was called upon to give 
 a regular course of lectures on geology and the connected 
 sciences, aided by his magnificent museum, and by ample 
 illustrations from drawings. 
 
 The WONDERS OF GEOLOGY contain the substance 
 of the lectures delivered by Dr. Mantell at Brighton. 
 The title is appropriate, but it would be great injustice to 
 consider this work as a mere collection of mirabilia. It 
 embraces, in truth, a regular system of geology, exhibiting 
 its leading facts, and clearly elucidating its philosophy, 
 which is the great object of the work. 
 
 The arrangement is from the modern to the most ancient, 
 or from the alluvial and diluvial, down through the ter- 
 tiary, secondary, and transition, to the primary rocks, and 
 all the igneous formations ; ending with the actual igni- 
 vomous mouths, as they appear in the existing volcanos. 
 
 Commencing with the human epoch, he proceeds 
 through the various formations which preceded the creation 
 of man ; and the several eras of the tertiary, the chalk, 
 the weald, the oolite and lias, the carboniferous strata, 
 and the primary rocks, are by turns the subject of instruc- 
 tive and eloquent comment. The work is illustrated with 
 much taste ; a frontispiece, by the celebrated British painter 
 Martin, gives a representation of the country of the Igua- 
 nodoii, representing the monsters of the ancient world attack- 
 ing and devouring each other ; two drawings of corals, by 
 Miss Mantell, form embellishments of first-rate beauty and 
 
38 
 
 interest ; and more than a hundred wood engravings, with 
 coloured sections of strata, maps, &c., bestow at once pic- 
 torial grace and scientific illustration on the volumes. A 
 work of this kind comprises a vast, an almost unlimited 
 field of inquiry, and requires in the writer who should do 
 justice to the subject, qualifications and powers of no 
 common character. 
 
 Thus much of the order ; now of the execution of the 
 WONDERS OF GEOLOGY. In point of science it is precise, 
 accurate, condensed, and cumulative in proof, conducting 
 the pupil forward by a series of steps, grateful in the pro- 
 gress, and conclusive in the result. The style is lucid and 
 elevated, while the figures render every thing intelligible, 
 even to the unscientific reader. The introduction which 
 precedes, and the retrospect which closes each lecture, 
 afford an admirable summary both of facts and doctrine, 
 and are distinguished by eloquent diction and comprehen- 
 sive views. As the greatest recommendation of Dr. 
 Mantell's work, we would remark, that it is an excellent 
 pioneer and conductor for the pupil attending a course of 
 lectures, and even for the private student, who has to work 
 his own way without a guide. In both these respects, it is 
 superior to any look with which we are acquainted, and we 
 are gratified in having it in our power to introduce it to the 
 American public under a form in which it can reach the 
 colleges, academies, and schools not to mention the studies 
 of literary men, and the parlours of families. It is a book 
 of delightful entertainment as well as of instruction, and 
 although less elaborate than the original works of investi- 
 gation of the same author, will find its way to many more 
 readers, and will, therefore, be even more extensively useful 
 than they have been. 
 
 The author modestly disclaims the merit of originality, 
 but the scientific world will not forget that his own original 
 investigations have been among the moat successful of the 
 
nge, and their results among the most brilliant obtained by 
 geoiogufe.* 
 
 The present work, like others of the same author, is dis- 
 tinguished by a reverend spirit towards the Author of 
 nature, who appears to be sometimes forgotten by those 
 who investigate his works, while Dr. Mantell's volumes 
 will leave a happy moral and religious impression upon the 
 minds of young persons. 
 
 It is an interesting fact that among the fine writers of 
 the present day, several of the geologists hold a very high 
 rank, and their works, although devoted to science, are also 
 an ornament to literature. Who can write better than 
 Sedgwick, Buckland, Lyell, Daubeney, Murchison, De La 
 Beche, Mantell, and many other geologists who might be 
 named ? 
 
 There is but one painful impression left on the mind, in 
 closing Dr. Mantell's volumes. He informs us that this is 
 his farewell to science, f as he must henceforth be solely 
 devoted to his arduous profession, and for this purpose he has 
 already left the classical fields of his own geological domain 
 Tilgate Forest and Brighton cliffs, and the South Downs of 
 Sussex to plant himself in a suburban village of the metro- 
 polis,]: as a practising surgeon and physician. We are thus 
 reminded of Blackstone's farewell to the Muses, when he 
 was about to enter the gloomy halls of the courts of law; 
 and still more forcibly, of the struggle of Garrick between 
 Comedy and Tragedy, as portrayed by the magic pencil of 
 Reynolds each rival sister wooing him with admitted and 
 almost prevailing attractions. In the present contest be- 
 tween medicine and science, each striving to appropriate 
 
 * The gold Wollaston medal of the .Geological Society of London 
 was awarded to Dr. Mantell for his discoveries in the Wealden of the 
 South-east of England. 
 
 t At least as a lecturer. 
 
 t Clapham Common, Surrey, three miles from London. 
 
40 
 
 to itself an honoured votary, we dare avow that our loyalty 
 is, at all hazards, engaged in favour of geology ; and we 
 cannot but express our deep regret, that a man who has 
 done honour to the British nation, and delighted the scien- 
 tific world hy his beautiful researches, should not be made 
 easy to pursue the bent of his own glowing and highly- 
 gifted mind, and thus to work onward in science until the 
 labour of life is done ! In conclusion we lament to add, that 
 from the death of the noble patron of the Sussex Institution, 
 the Earl of Egremont, and the supineness of some, and the 
 opposition of others of its members, Dr. Mantell has been 
 compelled to abandon the lowg-cherished hope of establish- 
 ing a county museum in his native province, and the 
 " Mantellian Museum " is now removed to the British 
 Museum ; Sussex, to the disgrace of its wealthy inhabitants, 
 being thus deprived for ever of that invaluable collection of 
 the natural records of its physical history. 
 
THE 
 
 WONDERS OF GEOLOGY. 
 LECTURE I. 
 
 . Introductory remarks. 2. Importance of geology. 3. Nature of 
 geology. 4. Harmony between revelation and geology. 5. Extent 
 of geological epochs. 6. Object of the lectures. 7. Physical struc- 
 ture of the earth. 8. Geographical distribution of animals and 
 vegetables. 9. Temperature of the earth. 10. Nature of the crust of 
 the globe. 11. Composition of the rocks and strata. 12. Classification 
 of rocks. 13. Primary rocks. 14. Transition strata. 15. Secondary 
 strata. 16. Tertiary strata. 17. Alluvial deposits. 18. Geological 
 mutations. 19. Connexion of geology with astronomy. 20. Nebular 
 theory of the universe. 21. Different states of nebulae. 22. Formation 
 of the solar system. 23. Gaseous state of the earth. 24. Geology 
 illustrated by astronomy. 25. Meteorites. 26. Mrs. Somerville on 
 meteorites. 27. Origin of meteorites. 28. Existing geological 
 changes. 29. Effects of streams and rivers. 30. Delta of the Ganges 
 and Mississippi. 31. Formation of strata. 32. Rippled sand. 33. 
 Lewes levels. 34. Remains of man in modern alluvium. 35. Peat 
 bogs. 36. Conversion of peat into coal. 37. Subterranean forests. 
 38. Geological effects of the sea. 39. Bed of the ocean. 40. Currents 
 and their effects. 41. Incrusting springs. 42. Incrustations not 
 petrifactions. 43. Lake of Solfatara. 44. Marble of Tabreez. 45. 
 Stalactites and stalagmites. 46. Grotto of Antiparos. 47. Consoli- 
 dation of sand and loose materials. 48. Destruction of rocks by carbonic 
 acid. 49. Carbonic acid gas in caverns and wells. 50. Consolidation 
 of loose strata by iron, 51. Recent formation of marine limestone 
 
THE WONDERS OF GEOLOGY. LECT. I. 
 
 in the Bermudas. 52. Fossil human skeletons of Guadaloupe. 53. 
 Impressions of human feet in sand-stone. 54. Isle of Ascension. 
 55. Drifted sand. 56. Sand-flood and recent limestones of Cornwall. 
 57. Silicious deposits. 58. The Geysers. 59. Hertfordshire con- 
 glomerate, or pudding-stone. 60. Effects of high temperature. 61. 
 Volcanic agency. 62. Expansion of rocks by heat. 63. Temple of 
 Jupiter Serapis. 64. Elevation of the coast of Chili. 65. Lifted sea 
 beach at Brighton. 66. Elevation of Scandinavia. 67. Retrospect. 
 
 1. INTRODUCTORY REMARKS. It has been ob- 
 served by a distinguished divine,* that in order to 
 obtain a proper sense of the interest and importance 
 of any science, and of the objects which it embraces, 
 nothing more is necessary than the intent and per- 
 severing study of them ; and that such is the con- 
 summate perfection of all the works of the Creator, 
 that every inquirer will discover a surpassing worth, 
 and grace, and dignity, in that especial department 
 of knowledge to which he may peculiarly devote 
 his attention. Whatever walk of philosophy he 
 may enter, that will appear to him the path which 
 is the most enriched by all that is fitted to captivate 
 the intellect, and to excite the imagination. Yet 
 before we can attain that elevation from which we 
 may look down upon and comprehend the mysteries 
 of the natural world, our way must be steep and 
 toilsome, and we must learn to read the records of 
 creation in a strange language. But when this 
 knowledge is once acquired it becomes a mighty 
 instrument of thought, enables us to link together 
 the phenomena of past and future times, and gives 
 
 * Professor Sedgwick. 
 
2, 3. NATURE OF GEOLOGY. 3 
 
 the mind a domination over many parts of the natural 
 world, by teaching it to comprehend the laws by 
 which the Creator has ordained that the actions of 
 material things shall be governed. 
 
 2. IMPORTANCE OF GEOLOGY. In the whole 
 circle of the sciences, there is perhaps none that 
 more strikingly illustrates the force and truth of 
 these remarks, than Geology ; none which offers to 
 its votaries rewards so rich, so wondrous and in- 
 exhaustible. In the shapeless pebble that we tread 
 upon, in the rude mass of rock or clay, the un- 
 instructed eye would in vain seek for novelty or 
 beauty ; like the adventurer in Eastern fable, the 
 inquirer finds the cavern closed to his entrance, and 
 the rock refusing to give up the treasures entombed 
 within its stony sepulchre, till the talisman is ob- 
 tained that can dissolve the enchantment, and 
 unfold the marvellous secrets which have so long 
 lain hidden. 
 
 3. NATURE OF GEOLOGY. To the mind which 
 is unacquainted with the nature and results of 
 geological inquiries, and which has been led to 
 believe that the globe we inhabit is in the state 
 in which it was first created, and that with the 
 exception of the effects of a general deluge, its 
 surface has undergone no material change, many 
 of the facts to be noticed in the course of these 
 lectures may appear almost incredible, and the in- 
 ferences deduced from their investigation be con- 
 sidered as the vagaries of the imagination rather 
 
 B2 
 
4 THE WONDERS OF GEOLOGY. LECT. I. 
 
 than the legitimate inferences of sound philosophy. 
 If, therefore, it be absolutely necessary, as it un- 
 questionably is, that in the pursuit of knowledge 
 of any kind, before even experience can be em- 
 ployed with advantage, we must dismiss from our 
 minds all prejudices, from whatsoever source they 
 may arise, this mental purification becomes the 
 more indispensable in a science like Geology, in 
 which we meet at the very threshold with facts so 
 novel and astounding; teaching us, that although 
 man and other living things be, as it were, but the 
 creation of yesterday, the earth has teemed with num- 
 berless forms of animal and vegetable life, myriads of 
 ages ere the existence of the human race. 
 
 Geology may be termed the physical history of 
 the earth, it comprehends the investigation of its 
 structure, and the characters and causes of the 
 various changes which have taken place in the 
 organic and inorganic kingdoms of nature. It has 
 been emphatically called, by one of our most emi- 
 nent philosophers, the sister science of Astronomy. 
 But, relating as it does to the history of the past, 
 and carrying us back, by the careful examination of 
 the relics of former ages, to periods so remote as to 
 startle all our preconceived opinions of the age of our 
 globe, the fate of its early cultivators has resembled 
 that of the immortal Galileo and the astronomers 
 of his time ; and for a similar reason, namely, the 
 supposed discrepancy between the discoveries and 
 inferences of science, and the Mosaic cosmogony. 
 
4. HARMONY WITH REVELATION. '> 
 
 4. HARMONY BETWEEN REVELATION AND GEO- 
 LOGY. There was a time when every geologist was 
 required to defend himself against imputations of 
 this kind, and I deeply regret to find that there still 
 exists in the minds of many well-meaning persons 
 a prejudice against the study of Geology, from a 
 mistaken apprehension, lest it should weaken our 
 belief in the revealed word of God ; for they assume 
 that a discrepancy must exist between the results of 
 geological inquiries and the Mosaic account of the 
 creation of the world. But, convinced as I am of 
 the utter impossibility that there ever can be any 
 collision between the purest piety and sound philo- 
 sophy, and that these prejudices have been created 
 and perpetuated by authors, who, falsely styling 
 themselves geologists, have mixed up their own 
 vague and erroneous notions with the history of the 
 earth as given by the inspired writer, attempting, 
 with the presumption of ignorance, to account for 
 that which lies beyond the reach of human investi- 
 gation, and to explain it by evidence equally 
 misapprehended and misapplied, I would most 
 unequivocally assert that a just view of the nature 
 and limits of geological science warrants no such 
 reproach. Abandoning all attempts to explain the 
 inexplicable, or to reconcile the irreconcilable, it 
 confines itself to its legitimate purpose of accumu- 
 lating and investigating facts, of pointing out 
 analogies, and indicating the inferences to which 
 they lead ; " this is far different from that pre- 
 
6 THE WONDERS OF GEOLOGY. LECT. I. 
 
 sumption which would fain prove the truth of 
 Scripture by physical evidence, or the weakness 
 that would found a system of natural philosophy 
 on the inspired record." Nothing is more un- 
 warrantable than attempts to identify theories in 
 science with particular interpretations of the sacred 
 text; and the caution of Lord Bacon, uttered a 
 century and a half before geology even had a name, 
 cannot be too often repeated. " Let no man," said 
 he, "upon a weak conceit of sobriety, or an ill- 
 applied moderation, think or maintain that a man 
 can search too far, or be too well studied in the 
 book of God's word, or the book of God's works 
 divinity or philosophy : but rather let men endeavour 
 an endless progress or proficiency in both ; only let 
 them beware that they apply both to charity and 
 not to arrogance to use and not to ostentation ; 
 and again, that they do not unwisely mingle or con- 
 found these learnings together." So deeply impressed 
 have I been with the necessity of strictly obeying 
 this admonition, that in all my written or oral dis- 
 cussions on geology I have, on this subject, in- 
 variably confined myself to a statement of the 
 opinions of several eminent philosophers and divines, 
 in the hope that the example of men, alike distin- 
 guished for their piety and learning, cultivating 
 with ardour this fascinating department of natural 
 science, and stating their conviction of its high 
 importance and beneficial influence upon the mind, 
 would be a sufficient and direct reply to the absurd 
 
5. EXTENT OP GEOLOGICAL PERIODS. 7 
 
 and unfounded charges brought against geology. 
 On the present occasion, I shall content myself with 
 the following extract from the sermons of the 
 present Bishop of London : " As we are not called 
 upon by Scripture to admit, so neither are we 
 required to deny the supposition, that the matter 
 without form, and void, out of ivhich this globe was 
 framed,' may have consisted of the wrecks and relics 
 of more ancient worlds, created and destroyed by 
 tJie same Almighty Power which called our world 
 into being, and will one day cause it to pass 
 away."* 
 
 Thus, while the Bible reveals to us the moral 
 history and destiny of our race, and instructs us that 
 man and the existing races of living things have 
 been placed but a few thousand years upon the 
 earth, the physical monuments of our globe bear 
 witness to the same truth ; and as astronomy un- 
 folds to us innumerable worlds, not spoken of in 
 the sacred record^ geology in like manner proves, 
 not by arguments drawn from analogy, but by 
 incontrovertible physical evidence, that there were 
 former conditions of our planet, separated from 
 each other by vast intervals of time, during which 
 this world was teeming with life, ere the creation of 
 man and the animals which are his cotemporaries. 
 
 5. EXTENT OF GEOLOGICAL EPOCHS. At the 
 first step we take in geological inquiries, we are 
 
 * Sermons, by Dr. Charles James Blomfield, Bishop of 
 London. 8vo. 1829. 
 
8 THE WONDERS OF GEOLOGY. LECT. I. 
 
 struck with the immense periods of time which the 
 phenomena presented to our view must have required 
 for their production, and the incessant changes which 
 appear to have been going on in the natural world : 
 but we must remember that time and change are 
 great only with reference to the faculties of the 
 beings which note them. The insect of a clay, 
 contrasting its ephemeral life with that of the 
 flowers on which it rests, would attribute an un- 
 changing permanence to the most evanescent of 
 vegetable forms ; while the flowers, the trees, and 
 the forests would ascribe an endless duration to the 
 soil on which they grow: and thus, uninstructed 
 man, comparing his transient earthly existence 
 with the solid framework of the world he inhabits, 
 deems the hills and mountains around him coeval 
 with the globe itself. But with the enlargement 
 and cultivation of his mental powers, man takes a 
 more just, comprehensive, and enlightened view of 
 the wonderful scheme of creation; and while in his 
 ignorance he imagined that the duration of the globe 
 was to be measured by his own brief span, and 
 arrogantly deemed himself alone the object of the 
 Almighty's care, and that all things were created 
 for his pleasures and necessities, he now becomes 
 conscious of his own dependence, and entertains more 
 correct ideas of the mercy, wisdom, and goodness 
 of the Creator. And while exercising his high pri- 
 vilege of being alone capable of contemplating and 
 understanding the wonders of the natural world, he 
 
6, 7. STRUCTURE OF THE EARTH. <) 
 
 learns that most important of all lessons to doubt 
 the evidence of his senses, until confirmed by cautious 
 and patient observation. 
 
 6. OBJECT OF THE LECTURES. With these in- 
 troductory remarks I proceed to the consideration 
 of the subjects selected for the present discourse. 
 And here I may observe, that, from the magnitude 
 and diversity of the objects embraced by geology, 
 it is scarcely possible to offer, in the space assigned 
 to a course of popular lectures, even an epitome 
 of the wonders which modern researches have 
 brought to light. This consideration therefore 
 must be my apology for the concise manner in 
 which many interesting facts may perhaps be noticed ; 
 and I would beg of you to consider that lectures of 
 this kind are intended to excite, rather than to 
 satisfy, a rational curiosity ; that they are designed 
 to promote a taste for philosophical pursuits, but 
 cannot supersede the necessity of study and of per- 
 sonal investigation. 
 
 7. PHYSICAL STRUCTURE OF THE EARTH. 
 The globe we inhabit may be described as a planetary 
 orb of a few thousand miles in circumference, and 
 of a spheroidal shape; its figure being such as a 
 body in a fluid state, and made to rotate on its 
 axis, would assume. Its mean density is five times 
 greater than that of water, the interior being double 
 that of the solid superficial crust : the internal 
 part of the earth, if cavernous, must therefore be 
 composed of very dense materials. Its surface is 
 
10 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. I. 
 
 computed to contain 190 millions of square miles, of 
 which three- fifths are covered by seas, and another 
 large proportion by vast bodies of fresh water, by polar 
 ice and eternal snows; so that taking into considera- 
 tion sterile tracts, morasses. &c., scarcely more than 
 one-fifth of the surface of the globe is fit for the 
 habitation of man and terrestrial animals.* The area 
 of the Pacific Ocean alone, is estimated as equal to 
 the entire surface of the dry land. The distribution 
 of the land is exceedingly irregular, the greater pro- 
 portion being situated in the northern hemisphere, 
 
 TAB. 1. THE EARTH AS SEEN FROM THE 
 
 as a reference to a terrestrial globe, or a map of the 
 world, will clearly demonstrate. 
 
 * Bakewell's Geology. f DC la Beche. 
 
8. DISTRIBUTION OF ANIMALS. 11 
 
 In a geological point of view, dry land may be 
 considered as so much of the crust of the earth as is 
 now above the level of the water, beneath which 
 it may again disappear. From accurate calculations 
 it is proved that the present land might be distri- 
 buted over the bed of the ocean, in such manner 
 that the surface of the globe would present an un- 
 interrupted sheet of water. Thus we perceive that 
 every imaginable distribution of land and water may 
 take place ; and consequently that every variety of 
 organic life may find at different periods suitable 
 abodes. 
 
 8. GEOGRAPHICAL DISTRIBUTION OF ANIMALS. 
 The investigation of the laws which govern the 
 geographical distribution of animals and vegetables 
 is highly interesting ; but as my limits compel me 
 to be brief, I must refer you to the third volume of 
 Mr. Lyell's " Principles of Geology," for more ample 
 details. It will be sufficient for our present purpose 
 to state, that although it might have been expected 
 that, all other circumstances being equal, the same 
 animals and plants would have been found in places 
 of like climate and temperature, this identity of dis- 
 tribution does not exist. When America was first 
 discovered, the indigenous quadrupeds were all dis- 
 similar to those of the old world. The elephant, 
 rhinoceros, hippopotamus, giraffe, camel, horse, 
 buffalo, lion, tiger, &c. were not met with on the 
 new continent; while the American species of mam- 
 malia, as the llama, jaguar, paca, coati, sloth, &c. 
 
12 THE WONDERS OF GEOLOGY. LECT. I. 
 
 were unknown in the olu. New Holland contains, 
 as is well known, a most singular assemblage of 
 mammalia, consisting of more than forty species 
 of marsupial animals, of which the kangaroo is a 
 familiar example. The islands of the Pacific Ocean 
 possess no quadrupeds, except hogs, dogs, rats, and 
 a few bats. 
 
 The distribution of vegetable life, although per- 
 haps more arbitrarily fixed by temperature and by 
 local influences than that of animals, presents many 
 anomalies. From numerous observations, however, 
 it appears that vegetable creation took place in 
 different centres, each having been the focus of a 
 peculiar genus or species ; for many plants have a 
 local existence, and vegetate naturally in one district 
 alone ; thus the cedar of Lebanon is indigenous on 
 that mountain, and does not grow spontaneously in 
 any other part of the world. It is also ascertained 
 that certain great divisions of the vegetable kingdom 
 are distributed over certain regions : we shall have 
 occasion to refer to this subject in the lecture de- 
 voted to the consideration of Fossil Botany. 
 
 9. TEMPERATURE OF THE EARTH. The tem- 
 perature of the surface of the globe depends on 
 the action of solar light and heat ; hence the 
 difference of the seasons, and climates of various 
 latitudes ; but there are many causes which modify 
 the distribution of the sun's influence, and produce 
 great local variations : under equal circumstances, 
 however, the temperature is found progressively to 
 
10. TEMPERATURE OF THE EARTH. 13 
 
 diminish from the equator to the poles. There is 
 also an internal source of heat, the cause of which 
 has not yet been determined, but is probably con- 
 nected with the original constitution of our planet. 
 It has been ascertained, by careful experiments, that 
 below the depth to which the solar heat can pene- 
 trate, there is an invariable increase of temperature, 
 amounting to 1 of Fahrenheit for every fifteen 
 yards : so that it is possible that at the depth of 100 
 miles beneath the surface of the earth, even the 
 least fusible mineral masses may be in a state of 
 incandescence. 
 
 10. NATURE OF THE CRUST OF THE GLOBE. 
 The greatest thickness of the superficial crust of the 
 globe, that is, of the mass of solid materials which 
 the ingenuity of man has been able to examine, 
 from the highest mountain peaks to the greatest 
 natural or artificial depths, is estimated at about 
 ten miles. As the earth is nearly eight thousand 
 miles in diameter, the entire series of strata hitherto 
 explored is, therefore, but very insignificant com- 
 pared with the magnitude of the globe ; bearing 
 about the same relative proportion, as the thick- 
 ness of this paper, to an artificial sphere a foot 
 in diameter ; the inequalities and crevices in -the 
 varnish of such an instrument would be equal 
 in proportionate size to the highest mountains 
 and deepest valleys. In the following diagram,* 
 
 From the Penny Cyclopaedia. 
 
14 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT I. 
 
 the relative proportions of the crust of the earth, 
 and the inequalities of its surface, as compared 
 with the mass of our planet, are attempted to be 
 shown.* 
 
 TAB. 2. DIAGRAM TO ILLUSTRATE THE PROPORTIONATE THICKNESS 
 OF THE CRUST OF THE EARTH. 
 
 The line from e to k represents a depth of 500 
 miles ; to the point i, a depth of 100 miles ; to the 
 line /, forty-five miles above the surface, the sup- 
 posed limit of the earth's atmosphere ; and the dark 
 line, a thickness of ten miles, the estimated depth 
 of the crust of the earth. The points d, e, /, <?, 
 indicate the altitude of the highest mountains in the 
 world ; ]* the depth of the sea is shown by the line 
 
 * To preserve as far as possible the language and spirit of 
 the original lectures, the references to the diagrams and speci- 
 mens are retained. The Author's collection is now removed 
 from Brighton, and deposited in the British Museum. 
 
 f The highest peak of the Alps, and of Europe, is Mont 
 Blanc, which is 15,660 feet above the level of the sea of the 
 Andes, Chimborazo, which is 21,425 feet and of the Hima- 
 layas, Dhwalagiri, estimated at 28,000 feet, being more than 
 five miles of perpendicular altitude. 
 
10. THE CRUST OF THE GLOBE. ]j 
 
 a, h, at the extremities of the arc. As a thickness 
 of 100 miles so far exceeds that of the whole of the 
 strata that are accessible to human observation, we 
 cannot doubt that disturbance of the earth's sur- 
 face, even to ten times the depth of those which 
 come within the scope of geological inquiry, may 
 take place, without in any sensible degree affecting 
 the entire mass of the globe,* If these facts be 
 duly considered, the mind will be prepared to receive 
 one of the most startling propositions in modern 
 geology namely, that the highest mountains have 
 once been the bed of the sea, and have been raised 
 to their present situations by subterranean agency, 
 some slowly, others suddenly, but all, geologically 
 speaking, at a comparatively recent period. 
 
 * Mr. Fairholme suggests the following ingenious method 
 to convey a general idea of the relative magnitude of the in- 
 equalities of the earth's surface. If we form a scale on the sand 
 of the sea-shore in the proportion of an inch to a mile, we shall 
 have a circle of 8000 inches, or 222 yards in diameter, which, 
 when marked out with small stakes, appears a very large area. 
 Placing ourselves upon any part of this circumference, we have 
 an opportunity of taking a jus{, though microscopic, view of the 
 surface. The highest mountains in the world would be repre- 
 sented by a little ridge five inches high ; the profound abyss of 
 the ocean by a groove of the same depth ; while the medium 
 inequality of sea and land would not exceed one inch. To form 
 an idea of smaller objects, we must examine an inch scale, 
 finely graduated, by the aid of a microscope, and we shall then 
 find that the tallest man would be about the 880th part of an 
 inch in height the size of the smallest animalcule observed in 
 fluids. 
 
16 THE WONDERS OF GEOLOGY. LECT. I. 
 
 11. COMPOSITION OF THE ROCKS AND STRATA. 
 The superficial crust of the globe is composed of 
 numerous layers and masses of earthy substances, 
 of which combinations of iron, lime, and silex, or 
 flint, constitute a large proportion ; the latter form- 
 ing forty-five per cent, of the whole. Those strata 
 which have been deposited the latest, bear evident 
 marks of mechanical origin, and are the water-worn 
 ruins of older rocks ; as we descend, materials of a 
 denser character appear, which also exhibit proofs 
 of having been subject to the action of water ; but 
 when we arrive at the lowermost in the scale, a 
 crystalline structure generally prevails ; and while 
 in the newer strata, trees, plants, shells, and other 
 remains of animals and vegetables are found in 
 profusion, in the most ancient rocks all traces of 
 organic forms are absent. 
 
 12. CLASSIFICATION OF ROCKS. In the infancy 
 of the science these remarkable facts gave rise to 
 an ingenious theory, which, however, from being 
 founded on insufficient data, has proved untenable. 
 Still it may be convenient to notice the hypothesis, 
 since the terms employed are still retained in the 
 nomenclature of geology. Agreeably to this 
 theory, the mineral masses of which the crust of 
 the earth is composed, are separated into three 
 groups. 
 
 13. PRIMARY ROCKS. 1st. The Primitive (now 
 called Primary) Rocks ; such as granite, sienite, 
 porphyry, &c. : these are of a crystalline structure, 
 
14,15. CLASSIFICATION OF STRATA. 17 
 
 and have evidently been reduced to their present 
 state by igneous agency. They are the lowermost 
 rocks, and constitute the foundation, on which all 
 the newer strata have been deposited ; they also 
 attain the highest elevations on the surface of the 
 globe. They were termed primitive, because it 
 was inferred, from the entire absence of organic 
 remains, that they had been formed before the crea- 
 tion of animals and vegetables ; but it is now ascer- 
 tained that granite and its associated rocks are of 
 various ages, and are sedimentary deposits altered 
 by exposure to a very high temperature. 
 
 14-. TRANSITION STRATA. 2d. The Transition 
 Strata. These are super-imposed on the primitive, 
 are more or less distinctly stratified, and contain 
 the fossilized remains of animals and plants. They 
 received the name of transition, because it was 
 assumed that they had been formed at a period 
 when the surface of the earth and the seas were 
 passing into a state fit for the reception of orga- 
 nized beings. Modern researches have, however, 
 shown that they are, like the primary rocks, strata 
 modified by the effects of heat under great pres- 
 sure. 
 
 15. SECONDARY STRATA. 3d. The Secondary. 
 These have clearly originated from the destruction 
 of the more ancient rocks, and have been deposited 
 in hollows or depressions, by the action of rivers 
 and seas. They abound in the mineralized remains 
 of animals and plants ; the most ancient inclosing 
 c 
 
18 THE WONDERS OF GEOLOGY. LECT, I 
 
 zoophytes and shells r the next in antiquity conr 
 taining, in addition, vegetable remains and fishes ; 
 those which succeed enveloping not only fishes, 
 shells, zoophytes, and plants, but also insects and 
 bones of enormous reptiles, of birds, and of one or 
 more genera of marsupial animals. The chalk is 
 the uppermost, or most recent of this class. As 
 the secondary rocks have manifestly been formed 
 by the agency of water, it is clear that they were 
 originally deposited in horizontal, or nearly hori- 
 zontal layers or strata, although by far the greater 
 portion has since been broken up, and now lies in 
 directions more or less inclined to the horizon, 
 
 For the convenience of study, this subdivision of 
 the rocks is still retained, as will hereafter be shown. 
 To the above groups modern geologists have added 
 a fourth class, the Tertiary. 
 
 16. TERTIARY STRATA. 4th. The Tertiary.* 
 These lie in hollows or basins of the chalk, and 
 other secondary rocks, and are formed of the de- 
 tritus of the more ancient beds. They abound in 
 shells, plants, zoophytes, Crustacea, fishes, &c. : and 
 in them, with but one exception, the bones of mam- 
 malia first appear. 
 
 17. ALLUVIAL DEPOSITS. Of a later formation 
 than the tertiary strata, are those accumulations of 
 water-worn materials, which are spread over the 
 surface of almost every country more or less abun- 
 
 * See Plate X. Fig. 3. 
 
18. GEOLOGICAL MUTATIONS. 19 
 
 dantly. These are termed alluvial deposits;* they 
 contain remains of the existing races of animals and 
 plants, associated with those of species that are no 
 longer to be met with on the face of the earth. 
 
 Even this slight examination of the strata affords 
 convincing proofs of a former condition of animated 
 nature, widely different from the present. We have 
 evidence of a succession of periods of unknown 
 duration, in which both the land and the sea teemed 
 with forms of existence that have successively dis- 
 appeared and given place to others ; and these again 
 to new races, approaching gradually more and more 
 nearly to those which now inhabit the earth, till at 
 length existing species make their appearance. 
 . 18, GEOLOGICAL MUTATIONS. From this view 
 of the physical structure of our planet we learn, at 
 least so far as the limited powers of man can pene- 
 trate into the history of the past, that the distribution 
 of land and water on its surface has. been under- 
 going perpetual mutation ; yet, that through a vast 
 period of time, the physical condition of the earth 
 has not materially differed from the present ; that 
 the dry land has been clothed with vegetation, and 
 tenanted by appropriate inhabitants ; and that the 
 sea and the bodies of fresh water have swarmed 
 with living forms ; that at a remote epoch, though 
 animal and vegetable life existed, the species were 
 
 The term diluvial is applied by some geologists to the most 
 ancient of these deposits ; and that of alluvial to the modern 
 accumulations only. 
 
 c2 
 
20 THE WONDERS OF GEOLOGY. LECT. I. 
 
 wholly different from any that now abound, and the 
 greater number of a nature fitted to live in a tem- 
 perature much higher, and more equally distributed, 
 than occurs in the present state of the earth ; and 
 lastly, that in the inferior, or most ancient beds, all 
 traces of mechanical action, and of animal and vege- 
 table organization, are absent ; or in other words, 
 have either never existed, or have been altogether 
 obliterated. Before entering upon that department 
 of the subject to which the term Geology is com- 
 monly restricted, it will facilitate our comprehension 
 of many of the appearances which the strata pre- 
 sent to our notice, if in this place we endeavour 
 to penetrate the mystery that veils the earliest 
 condition of the earth ; but this we shall in 
 vain attempt, if we restrict our examination to 
 the physical phenomena observable in our own 
 planet. 
 
 19. CONNEXION OF GEOLOGY WITH ASTRONOMY. 
 Here Geology leads to Astronomy, and teaches 
 us to look to the kindred spheres around us for the 
 elucidation of the early history of the globe ; and 
 to consider the earth but as an attendant satellite 
 on a vast central luminary. The solar system con- 
 sists of the sun, whose mass is made up of solid 
 matter, which is surrounded by a luminous atmo- 
 sphere, or nebulosity ; and of eleven small planets, 
 which revolve around it in various periods ; the 
 earth being the third in distance from the sun, and 
 in bulk, as compared with that body, of the size of 
 
J 19. STRUCTURE OF THE MOON. 21 
 
 a pea to that of a globe two feet in diameter : and 
 having a satellite, the moon, revolving round it. 
 
 TAB. 3. TELESCOPIC VIEW OF THE MOON. 
 
 Upon examining the moon with powerful tele- 
 scopes, we perceive that its surface is diversified by 
 hills and valleys ; that it is a congeries of moun- 
 tains, many of which are manifestly volcanic, the 
 lava currents being distinctly visible. We see in 
 fact a torn, crateriform, and disturbed surface, like 
 that which we may conceive would be presented by 
 our earth, were the pinnacles of the granite moun- 
 tains unabraded, and the valleys neither smoothed, 
 nor filled up by sedimentary deposits.* In Venus 
 * See Appendix A. 
 
22 THE WONDERS OF GEOLOGY. LECT. L 
 
 and Mercury the mountains appear to be enormous; 
 while in Jupiter and Saturn there are but slight 
 traces of any considerable elevations. 
 
 20. NEBULAR THEORY OF THE UNIVERSE. 
 Astronomy instructs us that in the original con- 
 dition of the solar system the sun was the nucleus 
 of a nebulosity, or luminous mass, which revolved 
 on its axis, and extended far beyond the orbits of all 
 the planets ; the planets as yet having no existence. 
 Its temperature gradually diminished, and becoming 
 contracted by cooling, the rotation increased in 
 rapidity, and zones of nebulosity were successively 
 thrown off, in consequence of the centrifugal force 
 overpowering the central attraction : the condensa- 
 tion of these separated masses constituted the planets 
 and satellites. But this view of the conversion of 
 gaseous matter into planetary bodies is not limited 
 to our own system ; it extends to the formation of 
 the innumerable suns and worlds which are dis- 
 tributed throughout the universe. The sublime 
 discoveries of modern astronomers have shown that 
 very part of the realms of space abounds in large 
 expansions of attenuated matter, termed nebulce, 
 which are irregularly reflective of light, of various 
 figures, and in different states of condensation, 
 from that of a diffused luminous mass, to suns and 
 planets like our own. It must be admitted that 
 this assertion appears astounding, and that it may 
 fairly be asked if man, the ephemeron of the mate- 
 rial world, can measure the vast epochs which 
 
20. NEBUtAR THEORY OF THE UNIVERSE. 2;> 
 
 mark the progressive development of suns and 
 systems ? The genius of Herschel has effected 
 this wonderful achievement, and explained the suc- 
 cessive changes by which suns and worlds are 
 formed, through the agency of the eternal and 
 unerring laws of the Almighty. By laborious and 
 unremitting observations, that illustrious philoso- 
 pher, and his highly gifted son, have demonstrated 
 the progress of nebular condensation, not indeed 
 from the appearances presented by a single nebula, 
 (for the process, probably, can only become sensible 
 through the lapse of hundreds, or thousands, of 
 years,) but by observations on the almost endless 
 series of related, contemporaneous objects in every 
 varied state of progression, from that of a cloud of 
 luminous vapour, to the most dense and mighty orbs 
 that appear in the firmament. As the naturalist in 
 the midst of a forest is unable by a glance to dis- 
 cover that the trees around him are in a state of 
 progressive change ; yet perceiving that there are 
 plants in different stages of growth, from the acorn 
 just bursting from the soil to the lofty oak that 
 stands the monarch of the woods, can readily, from 
 the succession of changes thus at once presented 
 to his view, ascertain the progression of vegetable 
 life, although extending over a period far beyond 
 his own brief existence : in like manner, the astro- 
 nomer, by surveying the varied condition of the 
 heavenly bodies around him, can, by careful induc- 
 tion, determine the nature of those changes, which, 
 
24 THE WONDERS OF GEOLOGY. Lzci. I. 
 
 as regards a single nebrla, the human mind might 
 otherwise be unable to ascertain.* Thus Herschel 
 has traced from nebular masses of absolute vague- 
 ness, to others which present form and structure, 
 the effects of the mysterious law which governs the 
 stupendous stellular phenomena that are constantly 
 taking place. 
 
 21. DIFFERENT STATES OF NEBULJE. Some of 
 
 Tab. 4. TELESCOPIC APPEARANCE OF VARIOUS NEBULAE. 
 
 the nebulce appear as mere clouds of attenuated 
 light others as if curdling into separate masses 
 
 * Sir John Herschel states, that the only change in a nebula 
 which he has yet observed, is in that of Orion. A small trans- 
 verse strip, which when he first figured that nebula was straight, 
 had become curved, and showed a knotty appearance, which it 
 did not before possess. Athenaum^ No. 565, p. 596. 
 
21. DIFFERENT STATES OF NEBULA. 25 
 
 while many seem assuming a spheroidal figure. 
 Others again present a dense central nucleus of 
 light surrounded by a luminous halo ; and a series 
 may thus be traced, from clusters of round bodies 
 with one or more increased points of condensation, 
 or of central illumination, to separate nebulae with 
 single nulcei, and with rings, to a central disk con- 
 stituting a nebular star and finally to an orb of 
 light with a halo like the sun ! 
 
 In the comets, those nebular bodies which belong 
 to our own and other systems, we have evidence 
 that even in the most diffused state of the luminous 
 
 Tab. 5. TELESCOPIC VIEW OF ENCKE'S COMET. 
 
 matter, the masses which it forms are subservient 
 to the laws of orbicular motion : of this fact an 
 
2ft THE WONDERS OF GEOLOGY. LECT.'I. 
 
 interesting proof is afforded by Encke's comet, that 
 mere wisp of vapour, which in a period but little 
 exceeding three years, revolves around the central 
 luminary of our system. 
 
 This beautiful theory of Herschel, and La Place, 
 explains by an easy and evident process the forma- 
 tion of planets and satellites, and accounts for the 
 uniform direction of their revolutions. And not 
 only is it believed that such is the law which 
 the Creator has established for the maintenance 
 and government of the universe, but it is satis- 
 factorily shown, upon mechanical principles, that 
 such nebulae must of necessity produce planetary 
 bodies. 
 
 22. FORMATION OF THE SOLAR SYSTEM. In 
 our own system, the sun is a planetary orb with 
 a luminous atmosphere, the central nucleus of a 
 once extensive nebulosity. During the conden- 
 sation of this nebula the planets \vere successively 
 thrown off; the most distant, as Herschel, being the 
 first or most ancient, followed by Saturn, Jupiter, 
 the four asteroids, Mars, the Earth, Venus, and 
 Mercury; the satellites, as distinct worlds, being 
 the most recent of the whole. It is inferred, that 
 in any given state of the rotating solar mass, the 
 outer portion or ring might have its centrifugal 
 force exactly balanced by gravity; but increased 
 rotation would throw off that ring, which might 
 sometimes retain its figure, of which we have a 
 beautiful example, in Saturn. This result, however, 
 
22. FORMATION OF THE SOLAR SYSTEM. 27 
 
 could not take place unless the annular band were 
 of uniform composition, which would rarely be the 
 
 Tab. 6. TELESCOPIC VIEW OP SATURN. 
 
 case ; hence the ring would most generally divide 
 into several portions, which might sometimes be of 
 nearly equal bulk, as in the asteroids; while in 
 others they might coalesce into one mass. The 
 solar nebulae, thus separated at various periods, and 
 constituting planets in a gaseous state, would neces- 
 sarily have a rotatory motion, and revolve in varying 
 orbits around the central nucleus ; and as refrige- 
 ration and consolidation proceeded, each might 
 project entire annuli or rings, and satellites, in like 
 manner as the sun had thrown off the planets them* 
 selves. 
 
 In addition to the appearances presented by the 
 nebulae of various states of attenuation and of 
 
28 . THE WONDERS OF GEOLOGY. LECT. I. 
 
 solidity, we have in the orbs of our own system 
 evidence of corresponding gradations of density* 
 The planets near to the sun are denser than those 
 which are more distant : thus Mercury, which is the 
 nearest, is the heaviest, being almost thrice as dense 
 as the earth ; while the density of Jupiter, which is 
 far removed, is not more than one-third that of our 
 planet; and Saturn, which, with the exception of 
 Herschel, is the remotest, is but little more than 
 one-eighth as dense ; and is supposed to be as light 
 as cork.* 
 
 But I must not pursue this sublime subject far- 
 ther; those who feel desirous of more ample in- 
 formation may consult a popular abstract of the 
 discoveries of modern astronomy, recently published, 
 under the title of " Views of the Architecture of the 
 Heavens." f 
 
 You will at once perceive that this theory can in 
 no wise affect the inference that the universe is the 
 work of an all-wise and omnipotent Creator. "Let 
 it be assumed that the point to which this hypothesis 
 guides us, is the ultimate boundary of physical 
 science that the nearest glimpse we can attain of 
 the material universe, displays it to us as occupied 
 by a boundless abyss of attenuated matter ; still we 
 are left to inquire how space became thus occupied 
 ' whence originated matter thus luminous ? And 
 
 * Introduction to Astronomy, by Sir J. F. W. Herschel. 
 f By Dr. Nichol, Professor of Practical Astronomy in the 
 University of Glasgow. 
 
23. GASEOUS STATE OF THE EARTH. 29 
 
 if we are able to establish by physical proofs, that 
 the first fact which the human mind can trace in the 
 history of the heavens is, that * there was light, we 
 are irresistibly led to the conclusion, that ere this 
 could take place, GOD SAID, Let there be light.' " * 
 
 This theory of the condensation of nebular matter 
 into suns and worlds, marvellous as it may appear, 
 will be found on due reflection to offer the only 
 rational explanation of the phenomena observable 
 in the sidereal heavens, and in our own globe ; and 
 its beautiful simplicity is in correspondence with the 
 unity of design so manifest throughout the works of 
 the Eternal. 
 
 23. GASEOUS STATE OF THE EARTH. Though 
 an unscientific inquirer may find it difficult to com- 
 prehend that our planet once existed in a gaseous 
 state, this difficulty will vanish upon considering the 
 nature of the changes that all the materials of 
 which the earth is composed must constantly un- 
 dergo. Water offers a familiar example of a sub- 
 stance existing on the surface of the globe, in the 
 separate states of rock, fluid, and vapour; for 
 water consolidated into ice is as much a rock as 
 granite or the adamant, and, as we shall hereafter 
 have occasion to remark, has the power of pre- 
 serving for an indefinite period the animals and 
 vegetables that may be therein imbedded. Yet, 
 upon an increase of temperature, the glaciers of 
 
 * Professor WhewelL 
 
30 xHE WONDERS OF GEOLOGY. LECT. I. 
 
 the Alps, and the icy pi inacles of the Arctic cir- 
 cles, disappear ; and, by a degree of heat still 
 higher, would be resolved into vapour; and by other 
 agencies might be separated into two invisible 
 gases oxygen and hydrogen. Metals may in like 
 manner be converted into gases ; and in the labo- 
 ratory of the chemist, all kinds of matter easily pass 
 through every grade of transmutation, from the 
 most dense arid compact to an aeriform state. We 
 cannot, therefore, refuse our assent to the conclu- 
 sion, that the entire mass of our globe might be 
 resolved into a permanently gaseous form, merely 
 by the dissolution of the existing combinations of 
 matter. 
 
 24-. GEOLOGY ILLUSTRATED BY ASTRONOMY. 
 From the light thus shed by modern Astronomy 
 upon many of the dark and mysterious pages of the 
 earth's physical history, we learn that the dynamical 
 changes which have taken place in our globe all 
 the wonderful transmutations of its crust revealed 
 to us by geological investigations may be referable 
 to the operation of the one, simple, and universal 
 law, by which the condensation of nebular masses 
 into worlds, through periods of time so immense as 
 to be beyond the power of human comprehension, 
 is governed. 
 
 The internal heat of the globe the evidence 
 afforded by fossil organic remains of a higher and 
 more equally diffused temperature of the surface in 
 an earlier state of the earth and the elevations 
 
$25. METEORITES. 31 
 
 and dislocations of its crust which have taken place, 
 and are still going on all refer to such an origin, 
 and to such a constitution of our planet, as that 
 contemplated by the nebular theory. The elevatory 
 process is not peculiar to the earth ; for, as we have 
 elsewhere remarked, Venus, Mercury, the Moon, 
 and perhaps the Sun itself, exhibit evidence of a 
 similar action.* In a philosophical point of view, 
 the present physical epoch of the earth '< is that of 
 the fluidity of water, which is the nebulous bed or 
 stratum last condensed, and which exerts mecha- 
 nical and chemical action upon the previously con- 
 solidated materials." f 
 
 25. METEORITES. Intimately connected with 
 this division of our subject, is the remarkable fact 
 of the fall of foreign bodies, called meteorites, or 
 meteoric stones, on our earth. The specimen before 
 me, for which I am indebted to my kind and distin- 
 guished friend, Professor Silliman, of Yale College, 
 Newhaven, Connecticut, is a fragment of the mass 
 which fell at Nanjenoy, in Maryland, in North 
 America, a few years since. The following descrip- 
 tion by an eye-witness of its descent, will serve to 
 illustrate the ordinary phenomena which attend the 
 appearance of these mysterious visitors. J 
 
 " On the 10th of February, between the hours of 
 
 * This subject is treated at large in Mr. De la Beche's 
 " Researches in Theoretical Geology." 
 t Dr. Nichol. 
 1 American Journal of Science. 
 
32 THE WONDERS OF GEOLOGY. LECT. I. 
 
 twelve and one o'clock, I heard an explosion, as I 
 supposed of a cannon, but somewhat sharper. I im- 
 mediately advanced with a quick step about twenty 
 paces, when my attention was arrested by a buzzing 
 noise, as if something was rushing over my head, 
 and in a few seconds I heard something fall. The 
 time which elapsed from my first hearing the report 
 to the falling, might have been fifteen seconds. I 
 then went with some of my servants to ascertain 
 where it had fallen, but did not at first succeed ; 
 however, in a short time the place was found by 
 my cook, who dug down to the stone, which was 
 discovered about two feet below the surface. It was 
 sensibly warm, and had a sulphurous smell : was of 
 an oblong shape, and weighed sixteen pounds and 
 seven ounces. It has a hard vitreous surface. I 
 have conversed with many persons, living over an 
 extent of perhaps fifty miles square : some heard 
 the explosion, while others noticed only the subse- 
 quent whizzing noise in the air ; all agree in stating 
 that the sound appeared directly over their heads. 
 The day was perfectly fine and clear. There was 
 but one report heard, and but one stone fell, to my 
 knowledge ; there was no peculiar smell in the air : 
 it fell within 250 yards of my house."* 
 
 ** An analysis of this meteorite gave the following results : 
 Oxide of Iron . . . .24. 
 
 Nickel . . . 1.25 
 
 Silica with earthy matter 3.46 
 Sulphur, a trace. 
 
 28JV 
 
26. METEORITES. 33 
 
 26. MRS. SOMERVILLE ON METEORITES. That 
 
 ornament and pride of her sex, Mrs. Somerville, has 
 the following interesting remarks on this subject : 
 " So numerous are the objects which meet our view 
 in the heavens, that we cannot imagine a part of 
 space where some light would not strike the eye : 
 innumerable stars thousands of double and mul- 
 tiple systems clusters in one blaze with their ten 
 thousands of stars and the nebulre amazing us by 
 the strangeness of their forms ; till at last, from the 
 imperfection of our senses, even these thin and airy 
 phantoms vanish in the distance. If such remote 
 bodies shone by reflected light, we should be un- 
 conscious of their existence ; each star must then 
 be a sun, and may be presumed to have its system 
 of planets, satellites, and comets, like our own ; and 
 for aught we know, myriads of bodies may be wan- 
 dering in space, unseen by us, of whose nature we 
 can form no idea, and still less of the part they 
 perform in the economy of the universe. Nor is 
 this an unwarranted presumption : many such do 
 come within the sphere of the earth's attraction, 
 are ignited by the velocity with which they pass 
 through the atmosphere, and are precipitated with 
 great violence to the earth. The fall of meteoric 
 stones is much more frequent than is generally 
 believed : hardly a year passes without some in- 
 stances occurring ; and if it be considered that only 
 a small part of the earth is inhabited, it may be 
 presumed that numbers fall into the ocean, or on 
 D 
 
34 THE WONDERS OF GEOLOGY. LECT. I. 
 
 the uninhabited parts o f the land, unseen by man. 
 They are sometimes of great magnitude : the volume 
 of several has exceeded that of the planet Ceres, 
 which is about seventy miles in diameter. One 
 which passed within twenty-five miles of us was 
 estimated to weigh about six hundred thousand tons, 
 and to move with a velocity of about twenty miles 
 in a second a fragment of it alone reached the 
 earth. The obliquity of the descent of meteorites, 
 the peculiar substances of which they are composed, 
 and the explosion attending their fall, show that 
 they are foreign to our planet. Luminous spots, 
 altogether independent of the phases, have been 
 seen on the dark parts of the moon ; these appear 
 to be the light arising from the eruption of vol- 
 canoes ; whence it has been supposed that meteorites 
 have been projected from the moon by the impetus 
 of volcanic eruption. If a stone were projected 
 from the moon in a vertical line with an initial 
 velocity of 10,992 feet in a second a velocity but 
 four times that of a ball when first discharged from 
 a cannon instead of falling back to the moon by 
 the attraction of gravity, it would come within the 
 sphere of the earth's attraction, and revolve around 
 it like a satellite. These bodies, impelled either by 
 the direction of the primitive impulse, or by the 
 disturbing action of the sun, might ultimately pene- 
 trate the earth's atmosphere and arrive at its surface. 
 But from whatever source meteoric stones may 
 come, it is highly probable that they have a common 
 
27. ORIGIN OF METEORITES. 35 
 
 origin, from the uniformity, we may almost say 
 identity, of their chemical composition."* 
 
 27. ORIGIN OF METEORITES. Von Hoff, in an 
 admirable essay on the origin of meteoric stones,-)- 
 observes, that although it is demonstrated mathe- 
 matically, that aerolites and masses of native iron 
 which fall from the air, may be derived from the 
 moon, yet the weight of evidence is in favour of 
 their being nebulous matter suddenly condensed, 
 and descending to this planet's surface when this 
 mysterious process takes place within the sphere of 
 the earth's attraction. These masses present a 
 general correspondence in their structure and ap- 
 pearance, having (with the exception of native iron) 
 a crystalline character internally, and externally a 
 black slaggy crust, as in this specimen from Nan- 
 jenoy. 
 
 Assuming then that our planet, when first called 
 into being by the fiat of the Creator, was a gaseous 
 mass " without form and void," and destined through 
 indefinite ages to undergo mutations which were 
 designed ultimately to prepare it for the abode of 
 the human race, we proceed to investigate the 
 causes and effects of those agencies by which its 
 surface is still modified. The consideration of what 
 Sir John Herschel so emphatically terms " that 
 mystery of mysteries," the successive appearance of 
 
 * Connexion of the Physical Sciences, p. 423. 4th Edition, 
 f A Translation of this Memoir appeared in Jameson's 
 Edinburgh New Philosophical Journal, July 1837. 
 D 2 
 
36 THE WONDERS OF GEOLOGY. LECT. I. 
 
 new forms of organic 'ife on our globe, will be 
 reserved for the concluding lecture. 
 
 28. EXISTING GEOLOGICAL CHANGES. In this 
 division of the subject, it will be my object to 
 explain in a clear and familiar manner some of those 
 physical changes which, unheeded or Unappreciated, 
 are taking place around us ; but which operating 
 on a large scale, and through a long period of time, 
 are capable of producing effects that materially 
 modify the earth's surface, and give rise to results 
 which, when viewed in the aggregate, fill the unin- 
 formed mind with astonishment, and cause it to 
 call up imaginary convulsions and catastrophes to 
 explain the result of some of the most simple ope- 
 rations of nature. As the mere lines that compose 
 the alphabet constitute, when placed in combination, 
 the mighty engine by which the master spirits of 
 our race enlighten and benefit mankind ; so natural 
 processes, in themselves apparently inadequate to 
 produce any important effects, become, by their com- 
 bined and continued operation, an irresistible power. 
 by which the dry land is converted into the bed of 
 the ocean, and the bed of the ocean into dry land ; 
 thus fulfilling that universal law of the Creator, 
 which subjects every particle of matter to incessant 
 change. 
 
 Before proceeding farther in this inquiry, I would 
 notice an opinion, so generally prevalent that it may 
 possibly be entertained by some present, namely, 
 that the phenomena which will come under our 
 
28. EXISTING GEOLOGICAL CHANGES. 37 
 
 consideration, have been produced by the deluge 
 recorded in Scripture. But whatever may have 
 been the modifications of the earth's surface pro- 
 duced by that catastrophe, they must on the present 
 occasion be wholly excluded from our considera- 
 tion, for the changes to which geological inquiries 
 relate are of a totally different character, and refer- 
 able to periods long antecedent to that miraculous 
 event. 
 
 I have now to direct your attention to those 
 natural operations which, when properly investi- 
 gated, will afford an easy explanation of facts of the 
 highest interest and importance ; will teach us how 
 this limestone has been formed of brittle shells, and 
 this marble filled with the coral to which it owes 
 its beautiful markings how wood has been changed 
 into stone, and plants and fishes have become in- 
 closed in the solid rock. I wish to explain to you that 
 the ground on which we stand was not always dry 
 land, but once constituted the bed of the sea that 
 the hills, now so smooth and rounded, and clothed 
 with beautiful verdure, have been formed in the 
 profound depths of the ocean, and may be regarded 
 as vast tumuli, in which the remains of beings that 
 lived and died in the early ages of the globe are en- 
 tombed j and that the weald of Kent and Sussex, 
 that rich and cultivated district which fills up the 
 area between the chalk hills of Sussex, Surrey, 
 Kent, and Hampshire, was once the delta of a river, 
 that flowed through a country which is now swept 
 
38 THE WONDERS OF GEOLOGY. LECT. I. 
 
 from the face of the earth a country more mar- 
 vellous than any that even romance or poetry has 
 ventured to portray. 
 
 29. EFFECTS OF STREAMS AND RIVERS. In 
 pursuance of this object I shall first take into con- 
 sideration the action of running water of streams, 
 and rivers. I need not dwell on those meteoro- 
 logical causes by which the descent of moisture on 
 the surface of the earth is regulated ; but shall 
 content myself with observing, that rivers are the 
 great natural outlets which convey the superfluous 
 moisture of the land into the grand reservoir, the 
 ocean. And so exactly is the balance of expenditure 
 and supply maintained, that all the rivers on the 
 face of the earth, though constantly pouring their 
 mighty floods into the ocean, do not affect its level 
 in the slightest perceptible degree ; we may there- 
 fore assume that the quantity of moisture evaporated 
 from the surface of the sea, is exactly equal to the 
 sum of all the water, in all the rivers in the world. 
 But although the body of fresh-water poured by the 
 rivers into the basin of the ocean is again displaced 
 by evaporation, yet there is an operation silently 
 and constantly going on, which becomes an agent of 
 perpetual change. The rivulets which issue from 
 the mountains are more or less charged with earthy 
 particles, worn from the rocks and strata over which 
 they flow: their united streams in their progress 
 towards the rivers become more and more loaded 
 with adventitious matter ; and as the power of 
 
$ 30. EFFECTS OF STREAMS AND RIVERS. 39 
 
 abrasion becomes greater, by the increase in the 
 quantity and density of the mass of water, a large 
 proportion of materials is mechanically or chemi- 
 cally suspended in the fluid, and carried into the 
 sea. If the current be feeble, much of the mud, 
 and the larger pebbles, will be thrown down in the 
 bed of the river hence the formation of the alluvial 
 plains in the valleys of the Arun, the Adur, the 
 Ouse, and Cuckmere, in this county.* But the 
 greater portion will be transported to the mouths 
 of the rivers, and there form those accumulations 
 of the fluviatile spoils of the land which constitute 
 deltas ; the finest particles, however, will be carried 
 far into the sea, and, transported by currents and 
 agitated by the waves, will at length be precipitated 
 into the profound and tranquil depths of the ocean. 
 But the waters convey not only the mud and water- 
 worn materials of the country over which they 
 flow: leaves, branches of trees, and other vegetable 
 matter and the remains of the animals that fall 
 into the streams, with shells and other exuviae, 
 human remains, and works of art, are also con- 
 stantly transported and imbedded in the mud, silt, 
 and sand of the delta, some of these remains being 
 occasionally drifted out to sea, and deposited in 
 its bed. 
 
 30. DELTAS OF THE GANGES, AND MISSISSIPPI. 
 The changes here contemplated, as they are going 
 
 * Sussex. 
 
40 THE WONDERS OF GEOLOGY. LECI. I. 
 
 on in our own island, may appear insignificant, and 
 incapable of producing any material effect on the 
 earth's surface ; but if we trace the results in 
 countries where these agents are now operating on 
 a larger scale, we shall at once perceive their im- 
 portance, and that time only is wanting, to form 
 accumulations of strata, equal in extent, and of 
 the same character with many of those ancient 
 deposits, which will hereafter come under our ob- 
 servation. 
 
 From experiments made with great care, it has 
 been ascertained that the quantity of solid matter 
 brought down by the Ganges and carried into the 
 sea annually, is equal to 6,368,077,440 tons : in 
 other words, to a mass of solid materials, equal in 
 size and weight to sixty times that of the great 
 pyramid of Egypt ; the base of that stupendous 
 structure covering eleven acres, and its perpendicular 
 height being 500 feet.* The Burrampooter, another 
 river in India, conveys annually as much earthy 
 matter into the sea as the Ganges. The waters of 
 the Indus, as the celebrated traveller, Captain Burns, 
 informed me, are alike loaded with earthy materials. 
 
 In the mighty rivers of America, the same effects 
 are observable; the quantities of trees brought down 
 by the Mississippi and imbedded in its deposits are 
 almost incredible, and the basin of the sea around 
 the embouchure of that river, is becoming shallower 
 
 * Lyell's Principles of Geology. 
 
30. DELTAS OF THE GANGES AND MISSISSIPPI. 41 
 
 every day, by the sole agency of the operations now 
 under consideration. In the sediments of these 
 rivers, the animals as well as the plants of the re- 
 spective countries are continually enveloped. It is 
 therefore evident, that should these deltas become 
 dry land, the naturalist could, by an examination of 
 the animal and vegetable remains imbedded in the 
 fluviatile sediments, readily determine the characters 
 of the fauna and flora of the countries through 
 which the rivers had flowed. We may here observe, 
 that in tropical regions, where animal life is pro- 
 fusely developed, and but little under the control of 
 man, the animal remains buried in deltas, are far 
 more abundant than in those of European countries, 
 which are thickly peopled, and in a high state of 
 civilization. The enterprising, but unfortunate 
 Lander informed me, just before he embarked on 
 his last fatal expedition to Africa, that many parts 
 of the Quorra, or Niger, so far as the eye could 
 reach, teemed with crocodiles and hippopotami ; and 
 so great was their number, that he was oftentimes 
 obliged to drag his boat on shore lest it should be 
 swamped by these animals. But it is unnecessary 
 for me to dwell longer on these operations ; it will 
 suffice to have shown, that by the simple effect of 
 running water, great destruction and modification 
 of the surface of the land are everywhere taking 
 place ; and at the same time, fluviatile deposits 
 are forming on an extensive scale, and enveloping 
 animal and vegetable remains. Thus, in the deltas 
 
42 THE WONDERS OF GEOLOGY. LECT. I. 
 
 of the rivers of this country, we find the bones and 
 antlers of the deer, horse, and other domesticated 
 animals, with the trunks and branches of trees and 
 plants of our island, river and land shells, human 
 bones, fragments of pottery and other works of 
 art : while in those of the Ganges and the Nile, the 
 remains of the animals and vegetables of India and 
 of Egypt are respectively entombed. 
 
 31. FORMATION OF STRATA. There is one 
 circumstance connected with these facts which it 
 will be necessary here to consider. The quantity 
 of water in streams and rivers varies considerably 
 at different periods of the year ; in the rainy season 
 the rivers are overflowing, and the waters remark- 
 ably turbid : the depositions, therefore, must be 
 much greater at those periods than in the summer 
 months, when the streams are feeble, and the rivers 
 shallow. In that part of the river affected by the 
 tides, there is also a constant flux and reflux of the 
 waters, and from these causes the depositions must, 
 to a certain degree, be periodical. Accordingly we 
 find them disposed in strata or layers, from the 
 partial consolidation of the surface of one bed of 
 mud, before the superincumbent layer was pre- 
 cipitated upon it. Thus wherever a fresh break 
 takes place in a bank of consolidated mud, in the 
 delta of the Nile, it is easy to trace the deposits of 
 each successive year, by means of the lighter earth 
 on the top of each. When a portion is taken into 
 the hand, it separates into layers ; and on closely 
 
32. RIPPLED SAND. 43 
 
 examining the edges of these, very delicate thin 
 lines are perceptible, showing a laminated structure, 
 like those observable in the coal-shales. Judging 
 from these layers, the annual deposits appear to 
 vary considerably, but the average thickness is little 
 more than a quarter of an inch.* 
 
 Where a river terminates in an extensive estuary, 
 the sea throws over the layer of mud brought down 
 by the river, a covering of sand : and frequently 
 these alternate with the greatest regularity, the re- 
 ceding of the tide allowing the fresh water to deposit 
 its mud, and the advance of the sea discharging sand 
 and marine exuvise over the surface. 
 
 32. RIPPLED SAND. And here we may notice 
 another phenomenon. Every one must have ob- 
 served, when walking by the banks of a river at low 
 water, or on the sands of the sea-shore, that when 
 the water has been agitated by the wind, the surface 
 of the mud, or sand, is undulated, or furrowed over 
 by the rippling of the waves, the marks presenting 
 various appearances, according to the force and di- 
 rection of the currents. Frequently too, the vermes 
 and molluscous animals mark the surface with 
 meandering lines, and ridges ; and these varied 
 markings on the sand are preserved, if a thin 
 layer of mud happen to be deposited over them 
 before the next advance of the waves. I shall have 
 
 * Letter to Professor Silliman from an American who visited 
 Egypt in 1834. 
 
44 THE WONDERS OF GEOLOGY. LECT. I. 
 
 occasion to refer to t'lese appearances hereafter. 
 We must also remark that there are certain kinds 
 of mollusca, or shell- fish, that can only live in fresh 
 water ; others that are confined to the sea ; while a 
 third class is restricted to the brackish waters of 
 estuaries. Accordingly, in the deposits under con- 
 sideration, the river and estuary species are abundant, 
 while the marine only occur as stragglers, and are 
 comparatively rare. Land plants, and those which 
 affect a marshy soil, as the equiseta, or mare's-tails, 
 reeds, rushes, &c. are likewise often accumulated in 
 such quantities as to form beds of peat. 
 
 33. LEWES LEVELS. It will serve to impress the 
 subject more forcibly upon our minds, if we refer to 
 some local example of fluviatile deposits : and from 
 its immediate vicinity to Brighton, I select the 
 valley of the Ouse, between Newhaven and Lewes, 
 which is one of several estuaries from whence the 
 sea has retired within the last eight or ten centuries. 
 This valley is bounded by an amphitheatre of chalk 
 hills, into which the river enters through a gorge of 
 the Downs on the north, and pursuing a tortuous 
 course, discharges its waters at Newhaven. This 
 alluvial plain is called Lewes Levels, and is here 
 and there flanked by headlands, and ancient cliffs ; 
 while a few insular mounds of chalk rise up through 
 the fluviatile depositions, which have been accumu- 
 lating during a long period of time. The following 
 diagram represents a section of the valley of the 
 Ouse, from east to west. 
 
33. LEWES LEVELS. 45 
 
 Here we have a depression (or basin, as it is 
 termed by geologists) of the chalk, partially filled 
 
 TAB. 7. VERTICAL SECTION OF LEWES LEVELS.* 
 
 up by layers of indurated mud or silt, the surface 
 of which is clothed with verdure; the bed of the 
 river (i.) is situated near the eastern chalk cliffs. 
 The deposits which repose on the chalk are as 
 follow : 
 
 1 . A bed of peat about five feet in thickness : 
 formed of decayed twigs and leaves of the hazel, 
 oak, birch, &c. inclosing trunks of large trees. 
 
 2. (A. A.) Blue clay, or indurated mud, con- 
 taining several species of fresh-water shells, like 
 those which now inhabit the river and ditches ; 
 with numerous indusice, or cases of the larvae 
 
 * A geological section represents the internal structure of the 
 earth on any given line, in a vertical direction ; and is either 
 (1) natural, as seen in cliffs, precipices, &c.; (2) artificial, as in 
 quarries, tunnels, and other excavations ; or (3) ideal, when 
 constructed from combinations of observations on the position 
 of strata in various localities. 
 
46 - THE WONDERS OF GEOLOGY. LECT. I. 
 
 of phryganecB, or cad' 1 is- worms. Bones of the 
 horse, and deer, also occur in the lower part of 
 this bed. 
 
 3. (B. B.) Clay, containing fresh- water shells, 
 with an intermixture of existing marine species, as 
 the common cockle, (cardium edule,) tellina, &c. 
 
 4. (c. c.) Blue clay, inclosing marine shells, viz. 
 cockles, muscles, &c. without any intermixture of 
 fluviatile species. In this bed a skull of the narwal, 
 or sea-unicorn (Monodon monoceros,) and of the 
 porpoise have been discovered. 
 
 From the nature of these deposits we learn that 
 this valley was once an arm of the sea, and that the 
 sequence of the physical changes which took place 
 was as follows : 
 
 First, There was a salt-water estuary, inhabited 
 by marine shell-fish of the same species as those 
 now existing in the British Channel ; and into which 
 cetacea occasionally entered. 
 
 Secondly, The inlet grew shallow, the water 
 brackish, and marine and fresh-water shells were 
 mingled in its blue argillaceous sediment. 
 
 Thirdly, The shoaling continued until fresh- 
 water so much predominated, that fluviatile shells, 
 and aquatic insects, could alone exist. 
 
 Fourthly, A peaty swamp, or morass was formed, 
 by the drifting of trees, and plants, from the forest 
 of Andreadswald, which formerly occupied the weald 
 of Sussex ; and terrestrial quadrupeds were occa- 
 sionally imbedded. 
 
34. REMAINS OF MAN IN ALLUVIUM. 47 
 
 Lastly, The soil being inundated by land floods 
 at distant intervals only, became a verdant marshy 
 plain.* 
 
 34% REMAINS OF MAN IN MODERN ALLUVIUM. 
 But the sediments in the river valleys of the 
 South Downs often contain not only the bones of 
 the deer, horse, boar, and other terrestrial animals, 
 but also human skeletons, which are sometimes 
 found inclosed in coffins of exceedingly rude work- 
 manship : together with canoes,-)- and other relics 
 
 * Geology of the South-east of England, p. 16. 
 
 t Ancient British Canoe. In 1835 a canoe was discovered at 
 the depth of several feet in a bed of silt, occupying an ancient 
 branch of the river Arun, at North Stoke, near Arundel. It 
 was presented, by my noble friend the late Earl of Egremont, 
 to the British Museum ; and is placed on the right hand of the 
 entrance of the court. This canoe is nearly thirty -five feet in 
 length, four and a half wide in the centre, three feet three inches 
 broad at one extremity, and two feet ten inches at the other ; and 
 is about two feet deep. It is formed of the single trunk of an oak, 
 which has been hollowed out and brought to its present shape 
 with great labour ; it is evidently the workmanship of a very 
 remote period, and in all probability was constructed by some of 
 the earliest inhabitants of our island, before the use of iron or 
 even brass was known : the original tree must have been fifteen 
 or sixteen feet in circumference. Three projections, left in the 
 interior of the boat, appear to have been designed for seats ; it 
 is manifest therefore that the persons who constructed this vessel 
 were unacquainted with the art of forming boards. This canoe 
 is so similar to some of those which were fabricated by the 
 aborigines of North America, when first visited by Europeans, 
 that we can have no hesitation in concluding that it was con- 
 structed in a similar manner ; namely, by charring such portions 
 of the tree as were to be removed, and scooping them out with 
 
48 THE WONDERS OF GEOLOGY. LKCT. I. 
 
 of the early inhabitants of our island. This human 
 skull, for which I am indebted to Warren Lee, Esq. 
 of Lewes, was dug up at a great depth in the blue 
 silt of Beeding Levels ; it was inclosed, together 
 with the other bones of the skeleton, in a coffin of 
 oak, which was evidently of high antiquity, being 
 formed of four rude planks, or rather squared trunks 
 of trees, held together by oaken pegs. The skull 
 is of a dark bluish-brown colour, like the bones of 
 the deer and horse of similar deposits ; an appear- 
 ance attributable to an impregnation of iron ; when 
 first dug up, blue phosphate of iron filled up the 
 interstices of the bones. The state of the teeth is 
 remarkable; they are worn down almost smooth, 
 although the individual must have been in the prime 
 of life ; a fact which seems to indicate that grain, 
 or some other hard substance, constituted a large 
 proportion of his customary food. 
 
 35. PEAT BOGS. Before proceeding to the next 
 subject, I will advert to those extensive accumula- 
 tions of vegetable matter called Peat Bogs. These 
 are morasses, covered with successive layers or beds 
 of mosses, reeds, equiseta, rushes, and other plants 
 that affect a marshy soil ; and in particular of a kind 
 of moss, the sphagnum palustre, which frequently 
 constitutes a large proportion of the entire mass. 
 
 stone instruments : no doubt this canoe belongs to the same 
 period as the flint and stone instruments called celts, which are 
 found in the tumuli on the South Downs ; it is now in the state 
 of peat or bog- wood. 
 
36. PEAT BOGS. 49 
 
 The beds of peat are annually augmented by the 
 peculiar mode of increase of the peat-moss, which 
 throws up a succession of shoots to the surface, 
 while the parent plants decay, and form a new layer 
 of the soil. 
 
 The peat bogs of Ireland are of great extent : 
 one of the mosses on the banks of the Shannon is 
 two or three miles in breadth, and fifty in length. 
 Mr. Lyell remarks, that the peat-mosses of the 
 North of Europe occupy the areas of the ancient 
 forests of oak and pine ; and that the fall of trees 
 from the effect of storms, or natural decay, by ob- 
 structing the draining of a district, and thus giving 
 rise to a marsh, is the origin of most of the peat 
 bogs ; mosses, and other marsh plants, spring up, 
 and soon overwhelm and bury the prostrate forests ; 
 hence the occurrence of trunks and branches of enor- 
 mous oaks, firs, &c. with their fruits. 
 
 De Luc states, that the sites of many of the ab- 
 original forests on the continent are now covered by 
 mosses and fens, and that many of these changes 
 are attributable to the destruction of the forests by 
 the Romans. A remarkable fact relating to peat 
 bogs must not be omitted ; namely, the occasional 
 occurrence of the bodies of men and animals, in a 
 high state of preservation, at a great depth. In 
 some instances the bodies are converted into a fatty 
 substance, resembling spermaceti, called adipocire. 
 
 36. CONVERSION OF PEAT INTO COAL.* A 
 
 * Dr. Jackson on the Geology of Maine. 
 E 
 
50 THE WONDERS OF GEOLOGY. LECT. I. 
 
 fact of great geological interest is the occurrence of 
 coal in peat bogs, since it proves that the conver- 
 sion of vegetable matter into a mineral, the origin 
 of which was formerly deemed questionable, takes 
 place, wherever circumstances are favourable for 
 the production of the bituminous fermentation. In 
 Limerick, in the district of Maine, one of the States 
 of North America, there are peat bogs of consider- 
 able extent, in which a substance exactly similar to 
 cannel coal is found at the depth of three or four 
 feet from the surface, amidst the remains of rotten 
 logs of wood, and beaver sticks : the peat is twenty 
 feet thick, and rests upon white sand. This coal 
 was discovered on digging a ditch to drain a por- 
 tion of the bog, for the purpose of obtaining peat 
 for manure. The substance is a true bituminous 
 coal, containing more bitumen than is found in any 
 other variety.* Polished sections of the compact 
 masses exhibit the peculiar structure of coniferous 
 trees, and prove that the coal was derived from a 
 species allied to the American fir. It has probably 
 been formed by the chemical changes supervening 
 upon fir-balsam, during its long immersion in the 
 
 * An analysis of 100 grains gave the following results : 
 
 Bitumen 72 
 
 Carbon 21 
 
 Oxide of iron .... 4 
 
 Silica 1 
 
 Oxide of Manganese . 2 
 
 100 
 
37,35. SUBTERRANEAN FORESTS. 51 
 
 humid peat ; the circumstances under which it was 
 placed being most favourable for that process to take 
 place, by which, as we shall show hereafter (see Lec- 
 ture VI.), vegetable matter is converted into coal. 
 
 37. SUBTERRANEAN FORESTS. Independently 
 of the trees immersed in peat bogs and morasses, 
 there are also found entire forests buried deeply in the 
 soil ; the trees having their roots, trunks, branches, 
 fruits, and even leaves, more or less perfectly pre- 
 served. Several accumulations of this kind have 
 been discovered on the coast of Sussex, occupying 
 low alluvial plains, that are still subject to periodical 
 inundations.* The trees are chiefly of the oak, 
 hazel, fir, birch, yew, willow, and ash ; in short, 
 almost every kind that is indigenous to this island 
 occasionally occurs. The trunks, branches, &c. are 
 dyed throughout of a deep ebony colour by iron ; 
 and the wood is firm and heavy, and sometimes 
 sufficiently sound for domestic use. In Yorkshire 
 it is employed in the construction of houses. The 
 specimens which I now place before you, for which 
 I am indebted to Professor Babbage, exhibit the 
 usual characters of such remains ; they are portions 
 of large trunks of yew, oak, and fir, from a peat 
 bog in Ireland. 
 
 38. GEOLOGICAL EFFECTS OF THE SEA. 
 While the mountains, valleys, and plains of the 
 interior of a country, are undergoing slow but per- 
 petual change by the combined effects of atmospheric 
 * See Illustrations of the Geology of Sussex, p. 288. 
 E2 
 
52 THE WONDERS OF GEOLOGY. LECT. I. 
 
 agency, and of running water, the coasts, and shores, 
 are exposed to destruction from the action of the 
 waves, and the encroachments of the sea. When 
 the land presents a high and rocky coast, the waves, 
 by their incessant action, undermine the cliffs, which 
 at length fall down, and cover the shore with their 
 ruins. The softer parts of the strata, as the chalk, 
 marl, clay, &c. are rapidly disintegrated and washed 
 away; while the more solid materials are broken, 
 and founded, by the continual agitation of the water, 
 and give rise to those accumulations of beach and 
 sand which skirt our sea-cliffs, and serve, in some 
 situations, to protect the land from further en- 
 croachments. But when the cliffs are entirely com- 
 posed of soft substances, their destruction is very 
 rapid, unless artificial means be employed for their 
 protection ; which, however, in many instances are 
 wholly ineffectual. 
 
 The encroachments of the ocean upon the land 
 effected by this operation, often give rise to sudden 
 and extensive inundations, and the destruction of 
 whole tracts of country. Along the Sussex coast the 
 inroads of the sea have been noticed in the earliest 
 historical records ; and the site of the ancient town 
 of Brighton has been entirely swept away, the sands, 
 and the waves, now occupying the spot where the 
 first settlers on these shores fixed their habitations.* 
 On low and sandy coasts, the waves drive the loose 
 and lighter materials towards the land ; and the 
 * See Geology of the South-East of England, p. 23. 
 
39. BED OP THE OCEAN. 53 
 
 drifted sand, becoming dry at the reflux of the tide, 
 is carried by the wind inland, and in some situ- 
 ations is accumulated in such_quantities as to form 
 ranges of hills, which in their progress overwhelm 
 fertile tracts, and engulf churches, and even entire 
 villages. These sand banks or downs, loose and 
 fluctuating as they are in their first stage of ad- 
 vancement, become, under certain circumstances, 
 fixed, and converted into solid stone a process to 
 which we shall presently advert. 
 
 39. BED OF THE OCEAN. But the production 
 of beach, gravel, and sand, on the shores, and the 
 drifting of sand inland, are effects far less important 
 than those which are going on in the profound 
 depths of the ocean. In the tranquil bed 6f the 
 sea, the finer materials, held in mechanical or chemi- 
 cal suspension by the waters, are precipitated and 
 deposited, enveloping and embedding their inha- 
 bitants, together with the remains of such animals 
 and vegetables of the land as may be floated down 
 by the streams and rivers. But, in the beautiful 
 language of Mrs. Hemans, 
 
 " The depths have more ! What wealth untold 
 
 Far down and shining through their stillness lies ! 
 They have the starry gems, the burning gold, 
 Won from a thousand royal argosies ! 
 
 " Yet more the depths have more ! Their waves have roll'd 
 
 Above the cities of a world gone by 
 Sand hath filled up the palaces of old, 
 Sea-weed o'ergrown the halls of revelry. 
 
>4 THE WONDERS OF GEOLOGY. LECT. I. 
 
 " To them the love of woma r hath gone down, 
 
 Dark flow their tides o'er manhood's noble head, 
 O'er youth's bright locks, and beauty's flowery crown." 
 
 Yes ! in these modern depositions, the remains of 
 man, and of his works, must of necessity be con- 
 tinually engulfed, together with those of the animals 
 which are his contemporaries. 
 
 Of the nature of the bed of the ocean, we can 
 of course know but little from actual observation. 
 Soundings, however, have thrown light upon the 
 deposits now forming in those depths, which are 
 accessible to this mode of investigation ; and thus 
 we learn, that in many parts immense accumulations 
 of the remains of testaceous animals, intermixed with 
 sand, gravel, and mud, are going on. Donati ascer- 
 tained the existence of a compact bed of shells, 100 
 feet in thickness, at the bottom of the Adriatic, 
 which in some parts was converted into marble. In 
 the British Channel, extensive banks of sand, im- 
 bedding the remains of shells, Crustacea, &c. are in 
 the progress of formation. This specimen, which was 
 dredged up a few miles from land, off Brighton, 
 is an aggregation of sand with recent marine shells, 
 oysters, muscles, limpets, cockles, &c. and minute 
 corallines ; and this example, from off the Isle of 
 Sheppey, consists entirely of cockles (Cardium 
 edule), held together by conglomerated sand. In 
 bays and creeks, bounded by granitic rocks, the 
 bottom is found to be composed of micaceous and 
 quartzose sand, consolidated into what may be 
 
40. CURRENTS, AND THEIR EFFECTS. 55 
 
 termed regenerated granite. Off Cape Frio, on the 
 Brazilian coast, solid masses of this kind were 
 formed in a few months, and in them were found 
 imbedded, dollars and other treasures from the 
 wreck of a vessel, to recover which an exploration 
 by the diving bell was undertaken. 
 
 40. CURRENTS, AND THEIR EFFECTS. The dis- 
 tribution over the bottom of the sea of the detritus 
 brought down by rivers and streams, and of the 
 materials worn away by the action of the waves on 
 the shores, is principally effected by the influence of 
 currents, which, from their regularity, permanency, 
 and extent, may be considered as the rivers of the 
 ocean. To this agency I can but briefly allude, and 
 shall restrict my remarks to the Gulf-stream, which 
 is the great current that transports the waters, and 
 the temperature of the tropical regions, into the 
 climates of the north. From the mouth of the 
 Red Sea a current about 50 leagues in breadth sets 
 continually towards the south west ; doubling the 
 Cape of Good Hope, it assumes a north-west direc- 
 tion, and in the parallel of St. Helena, its breadth 
 exceeds 1000 miles ; then taking a direction nearly 
 east, it meets in the parallel of 3 north, along the 
 northern coast of Africa, with a current from the 
 north ; entering the Gulf of Florida, they are re- 
 flected and form the Gulf-stream, which, passing 
 along the coast of North America, stretches across 
 the Atlantic to the British Isles. At the parallel of 
 38, nearly 1000 miles from the Straits of Bahama, 
 
56 THE WONDERS OF GEOLOGY. LECT. I. 
 
 the water of the stream is ten degrees warmer 
 than the air. The course of the Gulf-stream is so 
 fixed and regular, that nuts and plants from the 
 West Indies are annually drifted to the western 
 islands of Scotland. The mast of a man-of-war, 
 burnt at Jamaica, was driven ashore several months 
 afterwards on the Hebrides, "after performing a 
 voyage of more than 4000 miles under the direction 
 of a current which, in the midst of the ocean, main- 
 tains its course as steadily as a river upon the 
 land."* The quantity of detritus transported by 
 such a current must be immense, and we therefore 
 need not wonder at frequently finding the pro- 
 ductions of different climates associated together 
 in a fossil state. 
 
 41. INCRUSTING SPRINGS, &c. The phenomena 
 hitherto considered, are referable to the mechanical 
 action of water; and the effect has been that of 
 disintegration, and destruction, in the first instance ; 
 and in the second, of accumulations of sediments in 
 water-channels, and in the bed of the sea. We 
 must now refer to an operation of a totally different 
 character the power possessed by streams, as clear 
 and sparkling as poet ever feigned, or sung, of 
 consolidating loose materials, of converting porous 
 strata into solid stone, and of filling up their 
 own channels by the deposition of calcareous 
 matter. 
 
 That most fresh water holds a certain proportion 
 * Playfair's Works, edition 1822 ; vol. i. p. 414. 
 
41. INCRUSTING SPRINGS. 57 
 
 of carbonate of lime* in solution, is well known; 
 and also that changes of temperature, as well as 
 many other causes, will occasion the calcareous 
 earth to be in part or wholly precipitated. The 
 fur, as it is called, that lines a boiler which 
 has been long in use, affords a familiar illustration 
 of this fact. At the temperature of 60, lime is 
 soluble in 700 times its weight of water ; and if 
 to the solution a small portion of carbonic acid be 
 added, a carbonate of lime is formed, and pre- 
 cipitated in an insoluble state. If, however, the 
 carbonic acid be in such quantity as to supersaturate 
 the lime, it is again rendered soluble in water ; and 
 it is thus that carbonate of lime, held in solution by 
 an excess of fixed air, not in actual combination 
 with the lime, but contained in the water and acting 
 as a menstruum, is commonly found in all waters. 
 An absorption of carbonic acid, or a loss of that 
 portion which exists in excess, will therefore occasion 
 the calcareous earth to be set free, and precipitated 
 on any substances in the water, such as stones, sprigs, 
 and leaves of trees, &c. Some springs contain so 
 large a proportion of calcareous earth when they 
 first issue from the rocks, and so speedily throw it 
 down in their course, that advantage has been taken 
 of the circumstance to obtain incrustations of various 
 
 * Carbonate of lime consists of lime in combination with 
 carbonic acid gas, which is a most abundant natural product. 
 This gas is unrespirable, and when pure, will immediately suf- 
 focate an animal immersed in it. It extinguishes flame. 
 
58 THE WONDERS OF GEOLOGY. LECT. I. 
 
 objects, as leaves, brancnes, baskets, nests with eggs, 
 and even old wigs. The incrusting springs of Der- 
 byshire are celebrated for such productions. These 
 depositions are termed tufa, or travertine ; and in 
 Italy, and many other countries, they constitute 
 extensive beds of concretionary limestone, which 
 is often of a crystalline structure. The Cyclo- 
 pean walls and temples of Paestum, are formed of 
 this substance. At the baths of San Filippo, in 
 Tuscany, where the waters are highly charged with 
 tufa, this property is applied to a very ingenious 
 purpose. The stream is directed against moulds of 
 medallions, and other bas-reliefs, and very beautiful 
 casts are thus obtained ; of which we have an ex- 
 ample in this medallion, which bears the head of 
 Napoleon, and was presented to me by the Marquis 
 of Northampton. 
 
 42. INCRUSTATIONS NOT PETRIFACTIONS. As 
 specimens of this kind are commonly, but errone- 
 
 A 
 
 B 
 
 TAB. 8. INCRUSTATION. 
 A A A, Extremities of the twig unchanged; B B, the tufaceous crusl. 
 
 ously, termed petrifactions, I will briefly explain 
 their real nature. We have before us several 
 
42. INCRUSTATIONS NOT PETRIFACTIONS. 59 
 
 incrustations from various places : baskets of shells, 
 and nests with eggs, from Derbyshire ; a bird, from 
 Knaresborough, in Yorkshire ; and a twig, partially 
 incrusted, from Ireland. 
 
 I need scarcely observe, that on breaking such 
 specimens, we find the inclosed substances to have 
 undergone no change but that of decay, in a greater 
 or less degree. In this incrusted bird's nest, the 
 twigs of which it is composed, like the branch above 
 mentioned, are exposed in several places, and, as 
 you perceive, are not permeated by stony matter, 
 but are dry, and brittle. Now, a true petrifaction 
 is altogether of a different nature, the substance 
 being saturated throughout with mineral matter ; if 
 we break it, we find that every part of its structure 
 has undergone a change ; sometimes flint has filled 
 up the interstices, and upon slicing and polishing it, 
 the most delicate texture of the original may be de- 
 tected. Wood, for instance, which is so commonly 
 petrified by flint or chalcedony, may be cut so thin, 
 that with a powerful lens the ramifications of the 
 vessels and the structure of the tissues may be 
 seen, and from their form, and disposition, we may 
 determine the particular kind of tree to which the 
 specimen belonged, although it may have been cased 
 up in stone for ages. When bone is petrified, the 
 same phenomena are observable ; the most delicate 
 parts of the internal structure are preserved, and 
 all the cells are filled up with stone or spar, which 
 is oftentimes of a different colour from that of the 
 
60 THE WOXDERS OF GEOLOGY. LECT. I. 
 
 walls of the cells, and thus a natural anatomical pre- 
 paration, of great beauty and interest is formed. 
 
 43. LAKE OF THE SOLFATARA. The celebrated 
 lake of the Solfatara lies in the Campagna between 
 Rome and Tivoli, and is fed by a stream of thermal 
 water which flows into it from a neighbouring pool. 
 The water is of a high temperature, and is saturated 
 with carbonic acid gas, which, as the water cools, 
 is constantly escaping, and keeping up an ebullition 
 on the surface. The formation of travertine is so 
 rapid, that not only the vegetables and shell-fish 
 are surrounded and destroyed by the calcareous 
 deposition, but insects also are frequently incrusted. 
 In these beautiful specimens of travertine from 
 Solfatara, vegetable impressions are distinctly seen, 
 the cavities in the mass having been occasioned by 
 the decomposition of the vegetable matter.* The 
 stream that flows out of the lake fills a canal, which 
 is conspicuous at a distance, from the line of vapour 
 emanating from the water. 
 
 A considerable number of the edifices of both 
 ancient and modern Rome, are constructed of tra- 
 vertine, derived from the quarries of Ponte Luccano, 
 which have clearly originated from a lake of the 
 same kind. Paestum is also built of calcareous 
 tufa, derived from similar deposits. " The waters of 
 these lakes," says Sir Humphry Davy, " have their 
 rise at the foot of the Apennines, and hold in solu- 
 tion carbonic acid, which has dissolved a portion of 
 * See Appendix B. 
 
44. MARBLE OF TABREEZ. 61 
 
 the calcareous rocks through which it has passed ; 
 the carbonic acid is dissipated by the atmosphere, 
 and the marble, slowly precipitated, assumes a crys- 
 talline form, and produces coherent stones. The 
 acid originates in the action of volcanic fires on the 
 calcareous rocks of which the Apennines are com- 
 posed, and carbonic acid being thus evolved, rises 
 to the source of the springs derived from the action 
 of the atmosphere, gives them their impregnation, 
 and enables them to dissolve calcareous matter." 
 
 44. MARBLE OF TABREEZ. In Persia, a beau- 
 tiful transparent limestone, called Tabreez marble, 
 is formed by deposition from a celebrated spring 
 near Maragha, where the whole process of its 
 formation may be seen. In one part the water is 
 clear, in another dark, muddy, and stagnant ; in a 
 third it is very thick, and almost black ; while in 
 the last stage it is of a snowy whiteness. The 
 petrifying pools look like frozen water: a stone 
 thrown on them breaks the crust, and the water 
 exudes through the opening; and in some states 
 the process has proceeded so far as to admit of 
 walking on the surface of the lake. A section of 
 the stony mass resembles an accumulation of sheets 
 of paper, being finely laminated ; and such is the 
 tendency of this water to solidify, that the very 
 bubbles on its surface become hard, as if they had 
 been suddenly arrested, and metamorphosed into 
 stone.* 
 
 * Morier's Travels. 
 
62 THE WONDERS OF GEOLOGY. LECT. I. 
 
 45. STALACTITES, A^D STALAGMITES. By the 
 infiltration of water through limestone rocks, into 
 fissures and cavities, sparry concretions are produced 
 on the roofs, sides, and floors of caverns. The 
 concretionary masses which are dependent from 
 the roof like icicles, are called stalactites ; those 
 which form on the floor, from the droppings of 
 the water, are termed stalagmites; and when, as 
 frequently happens, the two unite, a singularly pic- 
 turesque effect is produced, the caves appearing 
 as if supported by pillars of the most extraordinary 
 beauty and variety.* Sometimes a linear fissure in 
 the roof, by the direction it gives to the dropping 
 of the lapidifying water, forms a transparent curtain 
 or partition. A remarkable instance of this kind 
 occurs in a cavern in North America, called Weyer's 
 Cave, which is situated in the limestone range of the 
 Blue Mountains.-)- There are also many caverns in 
 England, celebrated for the variety and beauty of 
 their sparry ornaments : those in Derbyshire are 
 well known. 
 
 46. GROTTO OF ANTIPAROS. The Grotto of 
 Antiparos in the Grecian Archipelago, not far from 
 Paros, is justly admired. The sides and roof of its 
 principal cavity are covered with immense in- 
 crustations of calcareous matter, which form either 
 stalactites, depending from above, or irregular pillars 
 rising from the floor. Several perfect columns 
 reaching to the ceiling have been formed, and others 
 * Appendix C. f Appendix D. 
 
46. GROTTO OF ANTIPAROS. (};j 
 
 are still in the course of formation, by the union of 
 the stalactite from above, with the stalagmite below. 
 These being composed of matter slowly deposited, 
 have assumed the most fantastic shapes ; while the 
 pure, white, and glittering spar, beautifully catches 
 and reflects the light of the torches of the visitors 
 to this subterranean palace, in a manner which 
 causes all astonishment to cease at the romantic 
 tales told of the place of its caves of diamonds, 
 and of its ruby walls; the simple truth, when de- 
 prived of all exaggeration, being sufficient to excite 
 admiration, and awe. Some of these concretions 
 form a thin curtain, which is perfectly trans- 
 parent. 
 
 The specimens which I have selected from my 
 collection, to illustrate these remarks, exhibit the 
 usual character of stalactitical concretions ; those 
 long stony icicles are from Portland ; and these 
 minute straws of spar, from an archway near the 
 Chain Pier, have been formed by the infiltration of 
 rain through the superincumbent bed of calcareous 
 rock. This mass of pebbles, held together by calc- 
 spar, is from the cliffs at Kemp Town ; and affords 
 a proof that in periods very remote, the same pro- 
 cess was in action along the Sussex shores. These 
 beautiful slabs of marble are portions of stalagmites, 
 from St. Michael's Cave, Gibraltar; and this large 
 conical mass, which has been cut through and 
 polished to show its structure, was dug up on the 
 summit of Alfriston-Hill, in Sussex, and must have 
 
64 THE WONDERS OF GEOLOGY. LECT. I. 
 
 been formed in some chalk cavern, of which no 
 traces now remain. 
 
 47. CONSOLIDATION OF SAND, AND LOOSE 
 MATERIALS. The changes effected by this pro- 
 cess in strata composed of loose materials, are of 
 still greater importance ; for by an infiltration of 
 crystallized carbonate of lime, sand is converted 
 into sand-stone, fragments of soft chalk are trans- 
 muted into a solid rock, as in the Coombe-rock of 
 Brighton, and accumulations of beach, and gravel, 
 into a hard conglomerate, as in this example of the 
 ancient shingle bed of the cliffs, at Rottingdean, 
 shells, into a building stone, as in this mass from 
 Florida, and broken corals, into limestone, as in 
 these specimens from Bermuda. By this agency, 
 the bones of animals become permeated with cal- 
 careous spar, and the medullary cavities lined with 
 crystals of carbonate of lime : and clay, which has 
 cracked by drying, has its fissures filled up, and be- 
 comes consolidated into those curious masses, called 
 septaria, which when polished, form the beautiful 
 slabs for which Weymouth is so celebrated. 
 
 48. DESTRUCTION OF ROCKS BY CARBONIC ACID 
 GAS. Although, in the instances cited above, water 
 by its combination with carbonic acid, occasions the 
 solidification of loose and porous beds of detritus, 
 yet the effect of this gas on certain rocks is that of 
 disintegration ; for by its solvent influence on the 
 felspar, granite itself is reduced to a friable state ; 
 the quartz and mica, which with felspar constitute 
 

 49. CARBONIC ACID GAS. 65 
 
 granite, being set at liberty. The disintegration of 
 granite, is a striking feature throughout extensive 
 districts in Auvergne, especially in the neighbour- 
 hood of Clermont. In the ancient shingle of the 
 cliffs at Kemp Town, near Brighton, blocks of 
 granite occur which may be crumbled to pieces 
 between the fingers. I have already shown you 
 masses of pebbles held together by calcareous spar, 
 from the same locality ; we have, therefore, exam- 
 ples in that ancient bed, both of the conservative 
 and disintegrating effects of carbonic acid cement- 
 ing the loose beach into solid blocks by calcareous 
 depositions ; and, when in a gaseous state, or com- 
 bined with water, dissolving the granite by its action 
 on the felspar. 
 
 49. CARBONIC ACID GAS IN CAVES AND WELLS. 
 The escape of carbonic acid through fissures, into 
 mines, wells, and caverns, is of frequent occurrence ; 
 and as the specific gravity of this gas is greater than 
 that of atmospheric air, it occupies the bottom of 
 these cavities, and its presence is seldom suspected 
 till shown by its deleterious effects ; it is called 
 choke-damp by miners. Fatal accidents often 
 happen to well-diggers and excavators from this 
 cause., 
 
 The Grotto del Cane, near Puzzuoli, four leagues 
 from Naples, has for centuries been celebrated on 
 account of the carbonic acid gas, containing in 
 combination much aqueous vapour, which is con- 
 stantly rising from fissures in the rock, and is con- 
 F 
 
66 THE WONDERS OF GEOLOGY. LECT. I. 
 
 densed by the coldness of the external atmosphere. 
 The floor of the cavern being lower than the en- 
 trance, the gas is spread over the bottom like a 
 pool of water, and the upper part is free from any 
 noxious vapour. The deleterious effects of the 
 carbonic acid is, therefore, not felt by any creature 
 whose organs of respiration are above the level of 
 this mephitic lake ; but if a dog, or other small 
 animal, enter the cave, it instantly falls senseless, 
 and would expire if not speedily removed : the 
 name of the cave is obviously derived from the ex- 
 periment being often made on dogs, for the amuse- 
 ment of visitors.* It is impossible to fire a pistol 
 at the bottom of the cavern ; for, although gun- 
 powder may be exploded even in carbonic acid by 
 the application of a heat sufficient to decompose 
 the nitre, and consequently to envelope the mass in 
 an atmosphere of oxygen gas, yet the influence of 
 a mere spark from steel produces too slight an 
 augmentation of temperature for this purpose.-)- 
 
 50. CONSOLIDATION OF LOOSE STRATA BY IRON. 
 Water charged with a large proportion of iron, 
 acts an important part in the consolidation of loose 
 materials, converting sand into iron-stone, and beach 
 or shingle into a ferruginous conglomerate. At 
 Clapham Common, and other places in the vicinity 
 of London, a very compact breccia occurs in 
 large blocks, being composed of chalk-flints, more 
 or less broken, and rolled, cemented together by 
 
 * See Sandys' Travels. f Daubeny on Volcanoes. 
 
50. CONSOLIDATION OF LOOSE STRATA BY IRON. G7 
 
 an infiltration of iron. In this example of a 
 horse-shoe firmly impacted in a mass of pebbles 
 and sand, from the sea-beach at Eastbourn, the 
 cement which binds the mass is derived from the 
 iron. Nails are frequently found in the centre of 
 a nodule of hard sandstone formed by this process ; 
 the nail having supplied the water with the mate- 
 rial by which the surrounding sand has become 
 changed into stone. I have here a cannon ball 
 imbedded in the centre of a nodule of iron-stone, 
 in which are several oyster shells : this specimen 
 was dredged up off the Sussex coast, and has evi- 
 dently been consolidated by the solution of iron 
 afforded by the partial oxidation of the cannon ball. 
 In this very interesting mass of breccia,* which has 
 been produced by a like process, are two silver 
 pennies of Edward I. This curious specimen, for 
 which I am indebted to George Grantham, Esq. of 
 Barcombe Place, Sussex, was obtained from a Dutch 
 vessel, which was stranded off Hastings a century 
 ago ; it is a conglomerate of glass beads, knives, 
 
 * This specimen was dug up at a depth of ten feet in the bed 
 of the river Dove, in Derbyshire ; and the coins are presumed 
 to be part of the treasures contained in the military chest of the 
 Earl of Lancaster, which was lost in crossing the river in the 
 dark ; the guards being alarmed by a sudden panic, and the 
 chest with all its contents thrown into the Dove. The Earl of 
 Lancaster was beheaded in March 1322 : the specimen was 
 discovered about six years since ; more than five centuries have, 
 therefore, elapsed since its submersion. See the Vignette of the 
 Title-page, vol. i. 
 
 F2 
 
68 THE WONDERS OF GEOLOGY. LECT. I. 
 
 and sand; the cementing material having been 
 derived from the oxidation of the blades. In 
 the bed of the Thames, large masses of a ferru- 
 ginous conglomerate are occasionally found, in 
 which Roman coins, and fragments of pottery, are 
 imbedded ; the stone being formed of sand and clay 
 impregnated and consolidated by ferruginous infil- 
 tration. 
 
 These specimens of oxide of iron were dug up in a 
 marshy soil, near Bolney, in Sussex, and are of the 
 same nature as the substance called bog-iron ore, 
 which so frequently occurs in peat. The ebony 
 colour of the woods from Ireland, which we have 
 already examined, has been derived from an im- 
 pregnation of iron. Specimens of bog-iron are not 
 uncommon in the superficial loam and gravel of 
 the south-east of England. 
 
 The consolidation of sand and other loose mate- 
 rials by these agencies, is taking place everywhere ; 
 on the shores of the Mediterranean ; on the coasts 
 of the West India Islands, and of the Isle of Ascen- 
 sion ; and on the borders of the United States ; thus 
 the remains of man, at Guadaloupe of turtles, 
 in the Isle of Ascension of recent shells, and 
 bones of ruminants, at Nice of ancient pottery in 
 Greece and of animal and vegetable substances. 
 in our own country, have become imbedded and 
 preserved. 
 
 I now proceed to notice a few instances of these 
 interesting and important operations, by which 
 
51. MARINE LIMESTONE. 69 
 
 much of the solid crust of the globe is continually 
 being renewed. 
 
 51. RECENT FORMATION OF MARINE LIMESTONE 
 IN THE BERMUDAS. The valuable series of speci- 
 mens before me (presented by W. D. Saull, Esq.) 
 is from the Bermuda Islands, and affords examples 
 of this class of deposits in different states of con- 
 solidation. The sea which surrounds the Bermudas 
 abounds in corals and shells ; and from the action 
 of the waves on the reefs, and on the dead shells, 
 the water becomes loaded with calcareous matter. 
 Much of this detritus is, no doubt, carried down to 
 the profound depths of the ocean, and there en- 
 velopes the remains of animals and vegetables, thus 
 forming new strata for the use of future ages ; but 
 a great proportion is borne by the waves towards 
 the shores, and deposited in the state of fine sand. 
 This sand is drifted inland by the winds, and be- 
 comes more or less consolidated by the percolation 
 of water, and the infiltration of crystallized car- 
 bonate of lime ; a fine white calcareous stone is thus 
 formed, which in some localities is sufficiently com- 
 pact for building. Imbedded in this limestone are 
 numerous shells and corals, of the species which 
 inhabit the neighbouring seas : in some instances 
 the large mottled trochus, so well known to col- 
 lectors both in its natural and polished state, with 
 all its colours preserved, is imbedded in a pure, 
 white limestone ; in many specimens the colours 
 are faded, and the shells very much in the state of 
 
70 THE WONDERS OF GEOLOGY. LECT. I. 
 
 those found in the tertiary strata at Grignon in 
 others the shelly matter is wanting, but the hard 
 limestone retains the forms and markings of the 
 originals. The corals are imbedded in a similar 
 manner ; and masses occur in the limestone so like 
 the fossil corals of the oolite of this country, that it 
 requires an experienced eye to detect their real 
 nature. 
 
 In a suite of specimens, showing the transition 
 from loose sand to a solid rock, we have 
 
 1. Broken shells and corals, retaining their colours. 
 
 2. Similar materials, more comminuted and com- 
 pletely bleached. 
 
 3. An aggregation of fine sand, broken shells, 
 and corals. 
 
 4. Coarse friable limestone, resembling soft chalk, 
 and composed of comminuted corals, &c. 
 
 5. Hard limestone, of similar materials. 
 
 6. Compact limestone, enveloping shells and peb- 
 bles. 
 
 7. A fine indurated limestone, so hard as to be 
 with difficulty broken by the hammer, inclosing 
 a few shells, and corals : this stone is employed 
 for building. 
 
 Mr. Lyell has described a fresh-water limestone, 
 containing recent shells and aquatic plants, which 
 is in the progress of formation in the lakes of For- 
 farshire, in Scotland.* In the specimens before us, 
 which were collected by Mr. Lyell, are various 
 * Geological Transactions, vol. i. p. 73, new series 
 
52. FOSSIL HUMAN SKELETONS. 71 
 
 species of fresh-water shells, and masses of that 
 common lacustrine plant, the Ckara medicaginula, 
 beautifully preserved ; even the minute seed-vessels 
 of the chara are found converted into stone, in pre- 
 cisely the same manner as those which occur in the 
 ancient fresh-water tertiary limestones. Here then 
 is an example of the formation of a modern lacus- 
 trine rock ; while, in the deposits at Bermuda, we 
 have proof that the sea is, at this time, producing 
 effects analogous to those which have given rise to 
 many of the ancient secondary strata. 
 
 52. FOSSIL HUMAN SKELETONS OF GUADALOUPE. 
 
 Similar formations are in progress along the shores 
 of the whole West Indian Archipelago ; and in St. 
 Domingo they have greatly extended the plain of 
 Cayes, where accumulations of conglomerates occur, 
 and in which, at the depth of twenty feet, fragments 
 of ancient pottery have been discovered. 
 
 A B 
 
 TAB. 9. PLAN OF THE CLIFFS AT GUADALOUPE. 
 
 A, Ancitnt rocks; B, recent limestone, in which human skeletons are 
 found imbedded. 
 
 On the north-east coast of the main land of Gua- 
 
72 THE WONDERS OF GEOLOGY. LECT. I. 
 
 daloupe, a bed of recent limestone forms a sloping 
 bank, or glacis, from the steep cliffs of the island 
 to the sea, and is nearly all submerged at high 
 tides. This modern rock is composed of conso- 
 lidated sand, and comminuted shells and corals, of 
 species now inhabiting the adjacent seas. Land 
 shells, fragments of pottery, stone arrow-heads, 
 carved stone and wooden ornaments, and human 
 skeletons, are found therein imbedded. This being 
 the only known undoubted instance of the occur- 
 rence of human bones in solid limestone, has excited 
 great attention ; and the fact, simple and self-evi- 
 dent as is its history, has been made the foundation 
 of many vague and absurd hypotheses. 
 
 In most instances the bones are dispersed ; but a 
 large slab of rock, in which a considerable portion of 
 the skeleton of a female is imbedded, is preserved 
 in the British Museum, and has been described by 
 Mr. Konig, in a highly interesting memoir in the 
 Philosophical Transactions, of 1814. 
 
 The annexed representation (TAB. 10.) will serve 
 to convey an idea of this celebrated relic, which 
 was detached from the rock at the Mole, near 
 Point-a-Pitre. 
 
 - In this specimen the skull is wanting, but the 
 spinal column, many of the ribs, the bones of the 
 left arm and hand, of the pelvis, and of the thighs 
 and legs, remain. The bones still contain some 
 animal matter, and the whole of their phosphate 
 of lime. It is remarkable, that the fragments 
 
52. 
 
 FOSSIL HUMAN SKELETONS. 
 
 73 
 
 of the skull of this very specimen have recently 
 been purchased for the museum at South Carolina, 
 
 TAB. 10. FOSSIL HUMAN SKELETON, FROM GUADALOUPE. 
 In the British Museum; size of the original, 4 feet 2 inches by 2 feet. 
 
 of a French naturalist, who brought them from 
 Guadaloupe ; and they have been described by Pro- 
 fessor Moultrie, of the Medical College of that 
 State. These relics consist of portions of the 
 temporal, parietal, frontal, sphenoidal, and inferior 
 maxillary bones, of the right side of the skull. An 
 entire skeleton was also discovered in the usual 
 position of burial ; another, which was in a softer 
 sandstone, was in a sitting posture. The bodies, 
 
74 THE WONDERS OF GEOLOGY. LECT. I. 
 
 thus differently situated, may have belonged to 
 distinct tribes. General Ernouf, who carefully 
 investigated this interesting deposit, conjectured 
 that the presence of the bones might be explained 
 by the circumstance of a battle, and the massacre 
 of a tribe of Gallibis by the Caribs, having taken 
 place near this spot, about 120 years ago, and the 
 bodies of the slain been interred on the shore; 
 the skeletons having subsequently been covered by 
 sand-drift, which has been converted into lime- 
 stone. Dr. Moultrie, however, from a rigorous 
 examination, and comparison of the bones of the 
 skull in his possession, is of opinion, that the 
 specimen in the British Museum did not belong 
 to an individual of the Carib, but to one of the 
 Peruvian race, or of a tribe possessing a similar 
 craniological development. 
 
 In another skeleton from Guadaloupe, now in 
 the museum of the Jar din des Plantes, and repre- 
 sented in the last edition of Cuvier's Theorie de la 
 Terre, the figure is bent, the spine forms an arc, 
 and the thighs are drawn up as if the individual 
 were in a sitting posture ; a portion of the upper 
 jaw, and the left half of the lower, with several 
 teeth, nearly the whole of one side of the trunk 
 and pelvis, and a considerable portion of the upper 
 and lower left extremities, are preserved (TAB. 11). 
 The stone is a travertine (page 58), and incloses 
 terrestrial and marine shells ; it is evident that the 
 former have be,en drifted by streams from the in- 
 
53. 
 
 IMPRESSIONS OF HUMAN FEET. 
 
 terior, and the latter deposited by the ocean. In 
 the bed from which this block was extracted, were 
 found teeth of the caiman (a species of crocodile), 
 
 TAB. 11. HUMAN SKELETON FROM GUADALOUPE. 
 In the Museum at Paris. 
 
 stone hatchets, and a piece of wood, having rudely 
 sculptured on one side a mask, and on the other 
 the figure of an enormous frog : it is of guaiacum, 
 but has become extremely hard, and as black 
 as jet. 
 
 53. IMPRESSIONS OF HUMAN FEET IN SAND- 
 STONE. In connexion with the occurrence of 
 human bones in limestone, I will here notice a 
 discovery of the highest interest, but which has not, 
 
76 THE WONDERS OF GEOLOGY. LECT. I. 
 
 as yet, excited among scientific observers the atten- 
 tion which its importance demands. I allude to the 
 fact announced in the American Journal of Science, 
 (vol. v. for 1822,) of impressions of human feet in 
 sandstone, discovered many years ago in a quarry 
 at St. Louis, on the western bank of the Mississippi. 
 
 TAB. 12. IMPRESSIONS OF HUMAN FEET IN SANDSTONE. 
 
 The above figure is an exact copy of the original 
 drawing, and exhibits the impressions of the soles 
 of two corresponding human feet, placed at a short 
 distance from each other, as of an individual standing 
 upright, in an easy position. The prints are de- 
 scribed as presenting the perfect impress of the feet 
 and toes, exhibiting the form of the muscles, and 
 the flexures of the skin, as if an accurate cast had 
 been taken in a soft substance. They were at first 
 supposed to have been cut in the stone by the native 
 
54. ISLE OF ASCENSION. 77 
 
 Indians, but a little reflection sufficed to show that 
 they were beyond the efforts of those rude children 
 of nature ; since they evinced a skill, and fidelity of 
 execution, which even my distinguished friend, Sir 
 Francis Chantrey, could not have surpassed. No 
 doubt exists in my mind, that these are the actual 
 prints of human feet in soft sand, which was quickly 
 converted into solid rock by the infiltration of cal- 
 careous matter, in the manner already described. 
 The length of each foot is ten inches and a half, the 
 spread of the toes four inches, indicating the usual 
 stature; and the nature of the impression shows 
 that the feet were unconfined by shoes or sandals. 
 This phenomenon, unique of its kind, is fraught 
 with so much importance, that I have requested 
 Professor Silliman to ascertain the nature of the 
 sandstone, and the period of its formation. Here- 
 after I shall have to direct your attention to im- 
 pressions of another kind, in rocks of immense 
 geological antiquity. 
 
 54?. ISLE OF ASCENSION. This island, which is 
 a volcanic cone in the midst of the Atlantic, appears 
 to have been a dome of trachytic rocks, subse- 
 quently affording vent to lava currents ; and its 
 shores are bounded by a conglomerate formed of 
 sand with comminuted shells, corals, echini, and frag- 
 ments of lava. In the suite of specimens before us 
 are portions of this conglomerate in various states 
 of consolidation. They are composed of corals, 
 which still retain their colour ; of shells, more or 
 
78 THE WONDERS OF GEOLOGY. LECT. 1. 
 
 less broken ; and of ^and of similar materials ; 
 they also contain pebbles of trachytic and glassy 
 lava. The shores of this island are a favourite 
 resort of turtles, which repair thither in immense 
 numbers, and deposit their eggs in the loose sand : 
 the rapid conversion of the coarse, calcareous banks 
 into solid stone, occasions the frequent imbedding, 
 and preservation of the eggs ; and there are speci- 
 mens in the cabinet of the Geological Society, in 
 which the bones of young turtles, just on the point 
 of being hatched, are well preserved.* The con- 
 glomerate of the Isle of Ascension is, as you may 
 observe, principally composed of corals. Here we 
 have another example of a rock formed of the calca- 
 reous skeletons of those wonderful forms of organic 
 existence. It is not my intention in this place to 
 dwell on the geological changes produced by recent 
 zoophytes, in the formation of coral reefs, &c., as 
 the examination of the recent, and fossil corals, will 
 form the subject of a subsequent lecture. 
 
 55. DRIFTED SAND. We have already briefly 
 alluded to the encroachments on the land by the 
 drifting of sand-banks, thrown up beyond the reach 
 of the tide, and driven by the winds inland ; thus 
 effecting the desolation of whole regions by their 
 slow, but certain progress. Egypt instantly presents 
 herself to the imagination, with her stupendous 
 pyramids, the sepulchres of a mighty race of mon- 
 archs, and the wonder of the world her temples, 
 * See LyelFs Principles of Geology, 5th edit. vol. iii. p. 269. 
 
55. DRIFTED SAND. 79 
 
 and palaces, once so splendid and massive, as to 
 bid defiance to the ravages of time her plains, 
 and valleys, formerly teeming with abundance, and 
 supporting a numerous population now stripped 
 of her ancient glories, her fairest regions depopu- 
 lated, and converted into arid wastes, her cities 
 overwhelmed, and prostrate in the dust and the 
 colossal monuments of her kings, and the temples 
 of her gods, half buried beneath the sands of the 
 Desert ! The drifting of the sands of the Lybian 
 desert by the westerly winds, observes M. De Luc, 
 has left no lands capable of cultivation on those 
 parts of the western bank of the Nile which are not 
 sheltered by mountains ; while in Upper Egypt, 
 whole districts are covered by moveable sands, and 
 here and there may be seen the summits of temples, 
 and the ruins of cities which they have overwhelmed. 
 " Nothing can be more melancholy," says Denon, 
 " than to walk over villages swallowed up by the 
 sand of the Desert, to trample under foot their 
 roofs and minarets, and to reflect that yonder were 
 cultivated fields, that there. grew trees, that here 
 were the dwellings of men, and that all have now 
 vanished. The sands of the Desert were in ancient 
 times remote from Egypt ; and the Oases which 
 still appear in the midst of this sterile region, are 
 the remains of fertile soils which formerly extended 
 to the Nile."* 
 
 * See an Essay, on the Moving Sands of Africa, in Professor 
 Jamieson's Translation of Cuvier's Theory of the Earth, p. 375. 
 
 Mr. 
 
80 THE WONDERS OF GEOLOGY. LECT. I. 
 
 56. SAND-FLOOD, A.-TD RECENT LIMESTONE OF 
 CORNWALL. On many parts of the shores of Scot- 
 land, sand-floods have converted tracts of great 
 fertility into barren wastes : and on the northern 
 coast of Cornwall an extensive district has been 
 covered by drifted sand, which has become con- 
 solidated by the percolation of water holding iron in 
 solution, and in some places forms ranges of low 
 mounds, and hills, forty feet high. This sandstone 
 offers a striking and most interesting example of 
 recent formation, and has been described by Dr. 
 Paris, in a memoir which I do not hesitate to cha- 
 racterize as one of the most graphic, and instructive 
 geological essays on modern deposits, that has ap- 
 peared in this country.* The sand has evidently 
 been drifted from the sea by hurricanes, probably at 
 a very remote period ; it is first seen in a slight, but 
 increasing state of aggregation, on several parts of 
 the shore in the Bay of St. Ives. Around the pro- 
 montory of New Kaye, the sandstone occurs in 
 various states of induration, from that of a friable 
 aggregate, to a stone so compact, as to be broken 
 
 Mr. Wilkinson, in a late highly interesting work, questions the 
 correctness of these inferences, as to the extent of the sand- 
 floods, and asserts, that at the present time the alluvial soil 
 on the increase, the deposits from the inundations of the Nile 
 more than counterbalancing the inroads of the sands ; and that 
 the land now capable of cultivation in the valley of Egypt is 
 greater than at the time of the Pharaohs. Manners and Customs 
 of the Ancient Egyptians, vol. i. pp. 218 222. 
 * Appendix E. 
 
57. SILICIOUS DEPOSITIONS. 81 
 
 with difficulty by the hammer ; and which is used 
 in the construction of churches and houses. Upon 
 examining the stone with a lens, it appears to be 
 principally made up of comminuted shells ; and it 
 is worthy of remark, that the shelly particles are 
 frequently found to be spherical, from the previous 
 operation of water, and some portions of the rock 
 closely resemble the ancient limestone called oolite, 
 which will hereafter come under our notice. The 
 rocks upon which the sandstone reposes are clay, 
 slate, and slaty limestone ; and the water effecting 
 their decomposition may have thus obtained the 
 iron, alumina, and other mineral matters by which 
 the loose sand has been converted into sand- 
 stone. 
 
 The infiltration of water thus impregnated, Dr. 
 Paris observes, is a common and extensive cause of 
 lapidificatiori : at Pendean cove, granitic sand is 
 gradually hardening into breccia, by this process ; 
 and in the island of St. Mary, is becoming indu- 
 rated by the slow action of water impregnated with 
 iron. 
 
 57. SILICIOUS DEPOSITIONS. Silicious earth, 
 or the earth of flint, is another abundant mineral, 
 and constitutes so large a proportion of the rocks 
 and strata, that it is computed to form, either in a 
 pure or combined state, nearly one-half of the 
 solid crust of the globe. The flints from our 
 cliffs, the boulders and gravel on our shores, and 
 the pebbles of agate, quartz, and chalcedony, are 
 
82 THE WONDERS OF GEOLOGY. LECT. i. 
 
 well-known examples of the usual varieties of 
 silex.* 
 
 I scarcely need observe, that this nodule of flint, 
 obtained from a neighbouring chalk quarry, has 
 once been in a soft or fluid state ; for here we per- 
 ceive impressions of shells, and of the spines of an 
 echinus deeply imprinted on its surface.-)- We have 
 already seen that water impregnated with carbonic 
 acid gas is capable of holding lime in solution ; and 
 that travertine, limestone, and other calcareous 
 deposits, have originated from this agency ; and 
 although, even in the present advanced state of 
 chemical knowledge, we are unacquainted with the 
 
 * Here I would digress for a few moments, to notice an 
 opinion which is so generally prevalent, that I may be permitted 
 to assume, that even some of my readers may not be prepared 
 at once to answer the question, Do stones grow ? The farmer 
 who annually ploughs the same land, and every year observes a 
 fresh CROP of stones, would probably answer in the affirmative ; 
 and the general observer, who had for successive years noticed 
 his gardens and plantations strewed with stones, notwithstanding 
 their almost daily removal, might entertain the same opinion. 
 A moment's reflection, however, will serve to show, that it is 
 impossible stones can be said to grow, in the proper acceptation 
 of the term. Organic bodies grow, because they are provided 
 with vessels by which they are capable of taking up and assimi- 
 lating particles of matter, and converting them into their own 
 substance ; but an inorganic body can only increase in bulk by 
 the addition of extraneous matter to its outer surface ; hence 
 stones may be incrusted, or they may become conglomerated 
 together, but they cannot grow. 
 
 f Vide " Thoughts on a Pebble ; or, a First Lesson in Geo- 
 logy." Fifth edition; 1837. 
 
53. THE GEYSERS. 83 
 
 process by which any large proportion of flint can 
 be held in solution by water, yet we have unques- 
 tionable proofs, that the solution of silicious earth 
 has been effected by natural processes, on a very 
 extensive scale. At the present moment, Nature, 
 in her secret laboratories, is still carrying on a 
 modification of the same process ; and of this fact 
 we have a remarkable instance in the Geysers of 
 Iceland, and in the springs of Carlsbad, in Bohemia. 
 Professor Silliman remarks, that " the sulphuret of 
 silicon, which is the base of silex, is very soluble, 
 and that silicious earth itself is taken up by fixed 
 alkalies, and by fluoric acid ; and that these agencies, 
 like most of those which are chemical, are rendered 
 more active by heat." A high temperature there- 
 fore appears necessary to enable water to dissolve 
 a large proportion of silex, &c. ; hence, we find that 
 the thermal springs of volcanic regions are the 
 principal agents by which silicious depositions and 
 incrustations, are at present produced. 
 
 58. THE GEYSERS. The Geysers, or boiling 
 fountains, of Iceland, have long been celebrated for 
 possessing this property in an extraordinary degree ; 
 holding a large proportion of silex in solution, and 
 depositing it, when cooling, on vegetables and other 
 substances, in a manner similar to that in which 
 carbonate of lime is precipitated by the incrusting 
 springs of which we have already spoken. Iceland 
 may be considered as a mass of volcanic matter ; 
 the only substances not of volcanic origin in the 
 
84 THE WONDERS OF GEOLOGY. LECT. I. 
 
 whole island, being beds of surturbrand, or bitu- 
 minous wood, in which occur leaves, trunks, and 
 branches of trees, with clay and ferruginous earth. 
 These strata support alternating beds of basalt, 
 tufa, and lava, which form the summit of the hill in 
 which the vegetable remains occur. The Geysers, 
 of which there are a considerable number, are 
 springs, or rather intermittent fountains of hot 
 water, which issue from crevices in the lava. A 
 fountain of boiling water, accompanied with a great 
 evolution of vapour, first appears, and is ejected to a 
 considerable height ; a volume of steam succeeds, 
 and is thrown up with great force, and a terrific 
 noise like that produced by the escape of steam 
 from the boiler of an engine. This operation con- 
 tinues sometimes for more than an hour ; an interval 
 of repose of uncertain duration succeeds, after which 
 the same phenomena are repeated. If stones are 
 thrown into the mouth of the cavity, from which 
 the fountain has issued, they are ejected with vio- 
 lence, after a short interval, and again jets of boiling 
 water, vapour, and steam appear in succession. 
 The eruptions of the " great Geyser," witnessed by 
 Sir G. S. Mackenzie,* were preceded by a sound like 
 the distant discharge of heavy ordnance, and the 
 ground shook sensibly ; the sound was rapidly re- 
 peated, when the water in the basin, after heaving 
 several times, suddenly rose in a large column, 
 
 * Travels in Iceland, in the summer of the year 1810, by 
 Sir George Steuart Mackenzie, Bart. 
 
58. 
 
 THE GEYSERS. 
 
 85 
 
 accompanied by clouds of steam, to the height of 
 ten or twelve feet. The column seemed to burst, 
 and sinking down, produced a wave, which caused 
 the water to overflow the basin. A succession of 
 
 TAB. 13. PLAN OF THE GEYSERS. 
 
 eighteen or twenty jets now took place, some of 
 which rose to a height of fifty or sixty feet. After 
 the last eruption, which was the most violent, the 
 
86 THE WONDERS OF GEOLOGY. LECT. I. 
 
 water suddenly left the basin, and sunk into the 
 pipe in the centre to a depth of ten feet. After a 
 few hours the eruption was repeated ; the jets some- 
 times attaining ninety feet in altitude. The basin 
 of the " great Geyser" is an irregular oval, about 
 fifty-six feet by forty- six, formed of a mound of 
 silicious depositions about seven feet high ; the pipe 
 through which the water is ejected being sixteen 
 feet in diameter at the opening, but contracting to 
 ten feet lower down ; its perpendicular depth is 
 estimated at sixty feet. Sir G. S. Mackenzie has 
 proposed an ingenious explanation of these pheno- 
 mena, which the diagram in the preceding page will 
 serve to illustrate. It is supposed that the water 
 from the surface percolates through crevices (Tab. 
 13, a) into a cavity in the rock (>), and heated 
 steam, produced by volcanic agency, rises through 
 fissures in the lava (cc). The steam becomes in 
 part condensed, and the water filling the lower part 
 of the cavity (d) is raised to a boiling temperature, 
 while steam under high pressure occupies the upper 
 part of the chasm. The expansive force of the 
 steam becomes gradually augmented, till at length 
 the water is driven up the fissure or pipe (e), and a 
 boiling fountain with an escape of vapour is pro- 
 duced, which continues playing till all the water 
 in the reservoir is expended, and the steam itself 
 escapes with great violence till the supply is ex- 
 hausted.* 
 
 * Travels in Iceland, p. 229. 
 
58. THE GEYSERS. 87 
 
 The silicious concretions formed by these springs 
 cover an extent of four leagues ; these are speci- 
 mens of the more friable varieties, presented me by 
 Professor Babbage. M. Eugene Robert, who has 
 recently visited Iceland, states that this curious 
 formation may be seen, passing by insensible grada- 
 tions, from a loose friable state, the result of a rapid 
 deposition, to the most compact and transparent 
 masses, in which impressions of the leaves of the 
 birch-tree, and portions of the stems, are distinctly 
 perceptible, presenting the appearance of the aga- 
 tized woods of the West Indies. Rushes, and vari- 
 ous kinds of mosses converted into a white silicious 
 rock, in which the minutest fibres are preserved, 
 also occur ; but on the margin of the Geysers, from 
 the splashing of the water, the depositions resemble 
 large cauliflowers ; and on breaking these masses, 
 vegetable impressions are often discovered. Nume- 
 rous thermal springs occupy the valley in the interior 
 of the island, in the midst of which the Geysers are 
 situated. It is evident that these waters arise from 
 deep crevices, in which they have been heated by 
 volcanic fires. The rivers proceeding from the 
 springs often resemble milk in appearance, owing 
 to the argillaceous bole which they take up in their 
 passage among the silicious concretions : such are 
 the white rivers of Olassai. Mount Hecla, like all 
 the mountains of Iceland, is entirely covered with 
 snow, and no smoke appears on its summit. Accu- 
 mulations of rolled masses of obsidian and pumice- 
 
88 THE WONDERS OF GEOLOGY. LECT. I. 
 
 stone form a layer on the flanks of the mountain, 
 thirty feet thick ; stems and branches of the birch- 
 tree occur in the midst of this bed ; they are the 
 remains of the ancient forests of the island, which 
 the volcanic eruptions have entirely extirpated.* 
 
 This modern silicious formation is a fact of great 
 interest and importance. It tells us in language 
 that cannot be mistaken, that the most insoluble 
 and refractory substances may be reduced to a 
 liquid state, and again become consolidated, and 
 assume other modifications, merely by the agency 
 of thermal waters ; hence the envelopement of the 
 delicate corals, shells, &c. which are so abundant in 
 flint nodules, is readily explained. 
 
 59. HERTFORDSHIRE CONGLOMERATE, OR PUD.- 
 DING-STONE. We have before us a collection of 
 conglomerates formed by carbonate of lime; in 
 other words, aggregations of pebbles, sand, shells, 
 and corals, which are cemented together by calca- 
 reous spar and by ferruginous solutions : but this 
 specimen is an example of a mass of rounded flint 
 pebbles, imbedded in a silicious paste, forming the 
 well-known substance called Hertfordshire pudding- 
 stone, which was formerly in much request ; for the 
 cement, being as hard and solid as the pebbles them- 
 selves, the stones admit of being cut and polished 
 by the lapidary into a great diversity of ornaments. 
 The formation of this rock must have been effected 
 by a stream of silicious matter flowing into a bed 
 * Bulletin de la Societe Geologique de France. 
 
60. EFFECTS OF HIGH TEMPERATURE. 89 
 
 of gravel, and converting some portions of the loose 
 pebbles into a solid mass, while those parts which 
 the liquid flint did not reach remained in the state 
 of loose water- worn materials. It is not my inten- 
 tion in this lecture to dwell on the silicification * of 
 the remains of animals and plants ; it will suffice to 
 remark, that in the silicified woods from the West 
 Indies the most minute vegetable structure may be 
 detected, although the specimens will strike fire 
 with steel. 
 
 60. EFFECTS OF HIGH TEMPERATURE. The 
 phenomena presented to our notice in this investiga- 
 tion of the Geysers of Iceland, lead to the conside- 
 ration of another agent in the transmutations that 
 take place in the crust of the globe. It must be 
 obvious to every intelligent mind, that beds of un- 
 connected and porous materials can have acquired 
 hardness and solidity only by one of the following 
 processes, namely : 1st, by matter dissolved in a 
 fluid, and afterwards deposited among the porous 
 masses in the manner just described ; or, 2dly, by 
 the reduction of the materials by heat into a state 
 of softness or fusion, and their subsequent conver- 
 sion, by cooling, into a solid mass.-)- Fire or to 
 speak more correctly, a high temperature, however 
 induced, whether by electro-magnetic influence, or 
 proceeding from central or medial sources of heat 
 and water, are therefore the great agents by which 
 the mineral masses composing the crust of our 
 * Petrifaction by flint. f Playfair. 
 
90 THE WONDERS OF GEOLOGY. LECT. I. 
 
 planet have been and are still being modified. We 
 have already seen how vast are the changes which 
 result from the effects of water ; we must now take 
 a rapid survey of the influence which caloric is 
 capable of exerting ; an influence far more universal 
 and varied than we may at first be prepared to ex- 
 pect. The expansive power which heat exerts on 
 most substances, and its conversion of the most 
 solid and durable bodies, first into a fluid, and lastly 
 into a gaseous state, are phenomena so familiar as 
 to require no lengthened comment. But the effects 
 of heat are found to vary according to the circum- 
 stances under which bodies are submitted to its 
 operation, and hence the changes induced by high 
 temperature beneath great pressure, are totally 
 different from those effected by fire on the surface, 
 under the ordinary weight of the atmosphere. A 
 familiar example will serve to illustrate my meaning. 
 Chalk consists of lime combined with carbonic acid ; 
 and as for agricultural, and other economical pur- 
 poses, it is desirable to have the lime in its pure 
 state, the chalk, or limestone, is exposed to a great 
 heat, in kilns erected in the open air, until all the 
 carbonic acid gas is dissipated, and the stone is said 
 to be burnt into quick-lime. In the specimens before 
 us, the same substance is seen in the state both of 
 chalk and lime. It may readily be conceived, that if 
 this operation were conducted beneath such a degree 
 of pressure as would prevent the escape of the gas, 
 the formation of quick-lime would not take place ; 
 
60. EFFECTS OF HIGH TEMPERATURE. 91 
 
 the chalk would be fused, and the carbonic acid, 
 released from its present relation with the calcareous 
 particles, would enter into other combinations, and 
 the mass when cooled, be wholly different from the 
 product of the lime-kilns, formed by the same 
 agency in the open air. Experiments have proved 
 that this opinion is correct. Sir James Hall exposed 
 pounded chalk to intense heat, under great pressure, 
 and it was fused, not into lime, but into crystalline 
 marble : even the shells inclosed in the chalk under- 
 went the same transmutation, yet preserved their 
 forms. That analogous changes have been effected 
 by natural operations we have abundant proof; but 
 in this stage of our inquiry it is only necessary to 
 remark, that where ancient streams of lava have 
 traversed chalk, the latter invariably possesses a 
 crystalline structure. We shall hereafter find, in 
 accordance with the beautiful and philosophical 
 theory of Dr. Hutton, that all the strata have been 
 more or less modified by heat, acting under great 
 pressure and at various depths; and that the present 
 position and direction of the materials composing 
 the crust of the globe, have been produced by the 
 same cause.* The Huttonian theory, indeed, offers 
 a most satisfactory explanation of a great proportion 
 of geological phenomena, enabling us to solve many 
 of the most difficult problems in the science ; and 
 it is but an act of justice to the memory of an 
 
 * See Playfair's Illustrations of the Huttonian Theory, 
 vol. i. p. 33, et seg. Edin. 1822. 
 
92 THE WONDERS OF GEOLOGY. LECT. I. 
 
 illustrious philosopher, and of his able illustrator, 
 Professor Play fair, to state that this theory, cor- 
 rected and elucidated by the light which modern 
 discoveries have shed upon the physical history of 
 our planet, is that embraced by the most distin- 
 guished modern geologists. 
 
 61. VOLCANIC AGENCY. Of the activity and 
 power of the agent to which these remarks more 
 immediately refer, the currents of melted rocks, 
 called lavas, ejected through crevices and fissures 
 of the earth, accompanied with evolutions of heat 
 and vapour, afford the most striking proofs ; and 
 the volcano, with its frequent concomitant the 
 earthquake, have in all ages excited the astonish- 
 ment and curiosity of mankind. It would be 
 foreign to the design of this discourse, to enter 
 at large upon the nature and causes of volcanic 
 action. Dr. Daubeny,* Mr. Scrope,f and others, 
 have published highly interesting treatises on the 
 subject ; and Mr. Lyell has given an admirable 
 sketch of volcanic phenomena. J I will only advert 
 to the increased temperature of the earth in pro- 
 portion as we descend from the surface towards 
 the interior, and the profound depths from which 
 thermal waters take their rise, as tending to support 
 the opinion, that volcanic eruptions are occasioned 
 by electro-chemical changes, which are constantly 
 
 * Daubeny' s Lectures on Volcanoes, 1826. 
 f Scrope's Considerations on Volcanoes, 1825. 
 J Principles of Geology, vol. ii. 
 
62, 63. EFFECTS OF HEAT. 93 
 
 going on in the interior of the globe. We shall 
 hereafter have occasion to demonstrate that dislo- 
 cations of the strata, with elevations of the bottom 
 of the ocean, and eruptions of melted mineral 
 matter, have taken place from the earliest geolo- 
 gical periods within the scope of our inquiries. 1 
 
 62. EXPANSION OF ROCKS BY HEAT. The ex- 
 pansive power of caloric, even in ordinary circum- 
 stances, is very considerable, as is shown by the 
 instrument called a pyrometer, which illustrates a 
 fact continually presented to our notice, namely, 
 the expansion of a bar of metal by heat, and its 
 contraction, by cooling, into its original dimensions. 
 The expansion of solid bodies by heat, when effected 
 on a large scale, gives rise to many interesting 
 phenomena. The careful experiments made by 
 Colonel Totten, on the expansion of granite, marble, 
 and ether rocks, by variations of temperature, have 
 shown that the mere expansion, or contraction, of 
 extensive beds of these materials, will account for 
 the elevation and subsidence of considerable tracts 
 of country, and explain many analogous pheno- 
 mena.* 
 
 63. TEMPLE OF JUPITER SERAPIS. One of the 
 most interesting examples of local elevation and 
 subsidence, apparently resulting from this cause, is 
 that afforded by the celebrated remains of the 
 temple of Jupiter Serapis, at Puzzuoli ; and which 
 Mr. Lyell, by selecting as the subject of the frontis- 
 
 * American Journal of Science, vol. xxii. 
 
94 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. 
 
 piece of his invaluable work, has for ever associated 
 with the Principles of Geology. 
 
 TAB. 14. TEMPLE OF JUPITER SERAPIS, 
 (From Mr. LyelCs Principles of Geology.) 
 
 These ruins are situated on the shore of the Bay 
 of Baiae, and consist of the remains of a large 
 building of a quadrangular form, seventy feet in 
 diameter ; the roof of which was supported by 
 twenty-four granite columns, and twenty-two of 
 marble, each formed of a single stone. Many of 
 the pillars are broken and strewed about the pave- 
 ment, but three remain standing nearly erect, and 
 
63. TEMPLE OF JUPITER SERAPIS. 95 
 
 on these are inscriptions, not traced by the Greeks 
 or Romans, but by some of the simplest forms of 
 animal existence, which have here left enduring 
 records of the physical changes that have taken place 
 on these shores, since man erected the temple in 
 honour of his gods. The tallest column is forty-two 
 feet in height ; its surface is smooth and uninjured 
 to an elevation of about twelve feet from the pede- 
 stal, where a band of perforations made by a species 
 of marine boring muscle (Modiolalithophaga) com- 
 mences, and extends to the height of nine feet, 
 above which all traces of their ravages disappear.* 
 The perforations, many of which still contain shells, 
 are of a pear shape, and are so numerous and deep 
 as to prove unquestionably that the pillars were 
 immersed in sea-water, at the very time when the 
 base and lower portions were protected by rubbish 
 and tufa ; and that the upper parts projected above 
 the waters, and consequently were placed beyond 
 the reach of the lithodomi.^ The platform of the 
 temple is now about one foot below high-water 
 mark ; and the sea, which is only forty yards dis- 
 tant, penetrates the intervening soil. The upper 
 part of the band of perforations is therefore at least 
 twenty-three feet above the level of the sea ; and 
 yet it is evident that the columns were once plunged 
 in salt water for a long period. It is equally clear 
 that they have since been elevated to a height of 
 
 * See Appendix F. 
 
 t Lithodomi, from lithos, stone, and demOf to build- 
 
96 THE WONDERS OF GEOLOGY. LECT. I. 
 
 twenty-three feet, still maintaining their erect posi- 
 tion, amid the extraordinary changes which they 
 have undergone, and incontrovertibly proving that 
 the relative level of the land and sea, on that part 
 of the coast, has changed more than once since the 
 Christian era ; each movement, both of subsidence 
 and elevation, having exceeded twenty feet.* Yet 
 there, at the present moment, are the remains of 
 that temple 
 
 " Whose lonely columns stand sublime, 1 
 
 Flinging their shadows from on high, 
 Like dials, which the wizard Time 
 Had raised to count his ages by ! " f 
 
 Professor Babbage attributes the tranquil eleva- 
 tion and depression of the temple, to the contraction 
 and expansion of the strata on which it was built. 
 The sources of volcanic action in the surrounding 
 country are very numerous, and a hot spring still 
 exists on the land-side of the ruins. The change of 
 level is therefore easily accounted for, by supposing 
 the temple to have been built on the surface when 
 the rocks were expanded by the effects of a high 
 temperature, and that they subsequently contracted 
 by slow refrigeration. When this contraction had 
 reached a certain point, a fresh accession of heat 
 from the neighbouring volcano increased the tem- 
 perature of the strata; which again expanded and 
 raised the ruins to their present level. J 
 
 * Principles of Geology, vol. ii. p. 268. 
 f Moore. J Appendix G. 
 
63. TEMPLE OF JUPITER SERAPIS. 97 
 
 Mr. Babbage carries out these views to explain 
 the elevation of continents and mountain ranges, 
 assuming the following facts as the basis of his 
 theory : 
 
 1st. As we descend below the surface of the 
 earth, the temperature increases. 
 
 2dly. Solid rocks expand by being heated, but 
 clay and some other substances contract. 
 
 3dly. Rocks and strata of dissimilar characters 
 present a corresponding difference as conductors of 
 caloric. 
 
 4thly. The radiation of heat from the earth varies 
 in different parts of its surface ; according as it is 
 covered by forests, mountains, deserts, or water. 
 
 5thly. Existing atmospheric agents, and other 
 causes, are constantly changing the condition of the 
 surface of the globe. 
 
 Thus wherever a sea or lake is filled up by the 
 wearing down of the adjacent lands, new beds are 
 formed, conducting heat much less quickly than the 
 water ; while the radiation from the surface of the 
 new land will also be different. Hence, any source 
 of caloric, whether partial or central, which pre- 
 viously existed below that sea, must increase the 
 temperature of the strata underneath to a mucli 
 higher degree' than before, because they are now 
 protected by a bad conductor;* and their expansion 
 
 * Sir John Herschel observes, that this process is precisely 
 similar to that by which a great coat, in a wintry day, increases 
 the feeling of warmth ; the flow of heat outwards being ob- 
 H 
 
98 THE WONDERS OF GEOLOGY. LECT I. 
 
 must therefore elevate the newly-formed deposits 
 above their former level; thus the bottom of an 
 ocean may become a continent. The whole ex- 
 pansion, however, resulting from the altered cir- 
 cumstances, may not take place until long after the 
 filling up of the sea; in which case its conversion 
 into dry land will result partly from the accumu- 
 lation of detritus, and partly from the elevation of 
 the bottom. As the heat now penetrates the newly- 
 formed strata, a different action may be induced ; 
 the beds of clay or sand may become consolidated, 
 and instead of expanding, may contract. In this 
 case, either large depressions will occur within the 
 limits of the new continent, or after another in- 
 terval, the new land may again subside, and form a 
 shallow sea. This sea may be again filled up by a 
 repetition of the same processes as before; and 
 thus alternations of marine and fresh-water deposits 
 may occur, having interposed between them the 
 productions of the dry land.* 
 
 To review the physical changes which are still 
 taking place around the Bay of Naples would prove 
 highly interesting, but my limits will only permit 
 me to observe, that whole mountains have been 
 elevated on the one hand, and temples and palaces 
 have sunk beneath the sea on the other. In our 
 
 structed, and the surface of congelation removed to a distance 
 from the body, by the heat thereby accumulated beneath the 
 new covering. 
 
 * Proceedings of the Geological Society, March 1834. 
 
64. ELEVATION OF THE COAST OF CHILI. yQ 
 
 sister island we have evidence of former changes 
 of a like nature, and which are alluded to by our 
 inimitable lyric poet, in the following beautiful 
 lines : 
 
 On Lough Neagh's banks as the fisherman strays, 
 
 When the clear cold eve's declining, 
 He sees the round towers of other days, 
 
 In the wave beneath him shining ! 
 
 Thus shall memory often, in dreams sublime, 
 Catch a glimpse of the days that are over ; 
 
 Thus, sighing, look through the waves of time 
 For the long faded glories they cover ! 
 
 64. ELEVATION OF THE COAST OF CHILI. One 
 of the most remarkable modern instances of the 
 elevation of an extensive tract of country, is that 
 recorded by Mrs. Maria Graham,* as having been 
 produced by the memorable earthquake which 
 visited Chili in 1822, and continued at short in- 
 tervals till the end of 1823. The shocks were felt 
 through a space of 1,200 miles, from north to south. 
 At Valparaiso, on the morning of the 20th of 
 November, it appeared that the whole line of coast 
 had been raised above its level ; an old wreck of a 
 ship, which could not previously be approached, 
 was now accessible from the land; and beds of 
 scallops were brought to light, which were not 
 before known to exist. " When I went to examine 
 the coast," says Mrs. Graham, " although it was 
 high- water, I found the ancient bed of the sea laid 
 * Now Mrs. Calcott. 
 H2 
 
100 THE WONDERS OF GEOLOGY. LECT. I. 
 
 bare and dry, with oysters, muscles, and other 
 shells, adhering to the rocks on which they grew : 
 the fish being all dead, and exhaling the most of- 
 fensive effluvia. It appeared to me, that there was 
 every reason to believe the coast had been raised 
 by earthquakes at former periods, in a similar 
 manner; for there were several lines of beach, 
 consisting of shingle mixed with shells, extending 
 in parallel lines to the shore, to the height of fifty 
 feet above the sea." * Part of the coast thus 
 elevated consists of granite ; and subsequent ob- 
 servations have proved that the whole of the country 
 was raised, from the foot of the Andes to far out 
 at sea; the supposed area over which the elevatory 
 movements extended, being about 100,000 square 
 miles ; a space equal in extent to half the kingdom 
 of France, Mrs. Somerville mentions, that a further 
 elevation to a considerable extent has also taken 
 place along the Chilian coast, in consequence of 
 the violent earthquake of 1835. 
 
 65. LIFTED SEA BEACH AT BRIGHTON. Ex- 
 amples of such changes occur in almost every part 
 of the world ; and there is perhaps no considerable 
 extent of country which does not afford some proof 
 that similar physical mutations have taken place in 
 modern times. And although I cannot point out 
 to you a temple of Serapis on our shores, yet within 
 a few hundred yards of Brighton, there is un- 
 questionable evidence that the relative level of land 
 * Geological Transactions, vol. i. second series. 
 
65. LIFTED SEA BEACH AT BRIGHTON. 10l' 
 
 and sea, has undergone great changes within, to 
 speak geologically, a comparatively recent period. 
 The upper part of the cliffs, extending from the 
 commencement of the low range by Shoreham, 
 to Rottingdean, is composed of chalk with rubble, 
 flints slightly rolled, and clay and loam ; the whole 
 being clearly an accumulation of water-worn mate- 
 rials, deposited in an estuary or bay of the sea. 
 The base of the cliffs, to the height of a few feet, 
 is composed of the solid chalk, which may be seen 
 at low water extending far out to sea, and is covered 
 here and there by shingle and sand. Between the 
 chalk and the superincumbent mass just described, 
 is a bed of shingle, composed of rolled chalk, flints, 
 pebbles, and sand, with boulders of granite, por- 
 phyry, and other rocks, not now met with on those 
 shores; in fact, an ancient sea beach, formed at 
 some remote epoch, in like manner as the present 
 bed of shingle, which skirts the base of the cliffs, 
 is in the progress of formation. Among the pebbles 
 of this ancient beach, are rolled masses of chalk 
 and limestone, which are full of perforations made 
 by boring shells ; here are several specimens, which 
 are similar to those made in the chalk-rock by 
 the recent pholades and mytili. As I shall have 
 occasion to revert to these cliffs in the next lecture, 
 this brief description will suffice for our present 
 purpose. 
 
 The following diagram represents a natural ver- 
 tical section of the cliffs, as seen in those parts 
 
102 THfi V^dNlJEAS OF GEOLOGY. LECT. I. 
 
 where the inroads of the sea have extended to the 
 chalk strata, and the face of the ancient cliff is 
 
 The Sea. 
 
 TAB. 15. ELEVATED BEACH AT BRIGHTON, EAST OF KEMP TOWN. 
 A, Elephant bed; B, ancient bed of shingle ; C, the chalk. 
 
 exposed, the new deposits being shown in profile ; 
 these consist of the following beds : 
 
 1. (A) Chalk, rubble, loam, &c., obscurely 
 stratified; this deposit, from its containing teeth 
 and bones of elephants, is called the Elephant- 
 bed; it constitutes the upper three-fourths of the 
 cliffs. 
 
 2. (B) Shingle, or sea beach and sand, many 
 feet above high-water mark. This ancient shingle, 
 which from the inroads of the sea extends in the 
 cliffs beyond Kemp Town but a short distance 
 inland, is constantly found beneath the loam and 
 clay, several hundred yards from the shore in the 
 western part of Brighton. In a well lately dug in 
 the Western road, the shingle bed was reached at 
 the depth of fifty-four feet. 
 
65. LIFTED SEA BEACH AT BRIGHTON. 103 
 
 3. (c) The undisturbed chalk, which forms a 
 sloping cliff, inland, or behind the beds (A) and (B), 
 passes under the ancient sea beach, and appears as 
 a terrace at the foot of the present cliffs.* 
 
 These appearances demonstrate the following 
 sequence of changes in the relative level of the 
 land and sea on the Sussex shores : 
 
 First. The chalk terrace on which the ancient 
 shingle rests, was on a level with the sea for a long 
 period ; and the beach was formed, like the modern 
 beach, by the action of the waves on the then ex- 
 isting cliffs. The rolled/condition of the materials, 
 and the borings of the lit/wdomi, prove a change of 
 level as decidedly as do the perforations in the 
 columns of the temple of Serapis. 
 
 Secondly. The whole line of coast, with the 
 shingle (B), was submerged to such a depth, as to 
 admit the deposition of the strata (A) above them. 
 
 Lastly. The cliffs were raised to their present 
 elevation, and at this period the formation of the 
 existing sea beach commenced. 
 
 The elevation of the sea-shore with beds of marine 
 shells, already alluded to as having been produced 
 by earthquakes on the Chilian coast, has here then 
 a parallel. A phenomenon of a like nature, but of 
 a far more ancient period, is observable at Castle 
 Hill, near Newhaven, about eight miles east of 
 Brighton, where is seen immediately beneath the 
 
 * See Geology of the South- East of England, p. 30 ; and 
 Fossils of the South Downs, p. 277. 
 
104 THE WONDERS OF GEOLOGY. LECT. I. 
 
 turf, a regular sea beach with beds of oyster-shells, 
 many feet in thickqess, lying on the summit of the 
 chalk cliffs, 150 feet above the level of the sea. 
 Near Bromley, in Kent, and at Reading, in Berk- 
 shire, similar accumulations of beach and oyster- 
 shells are to be found. Elevated shingles, of 
 comparatively recent epochs, occur on the shores 
 of the Frith of Forth, and also along the western 
 coasts of England, as Mr. Murchison has satis- 
 factorily demonstrated. 
 
 66. ELEVATION OF SCANDINAVIA. Having 
 thus adduced a few striking proofs of the mutations 
 which the land has undergone in past times, we are 
 led to enquire Is this change still going on ? Is 
 the alternate subsidence and elevation of the land 
 the effect of a law of nature, established from the 
 existence of the present condition of our planet, 
 and destined to continue in action while its physical 
 constitution remains the same ? We shall hereafter 
 find, that this law has been in constant action from 
 the earliest periods of the earth's history, of which 
 her physical monuments afford any indications; and 
 I now proceed to adduce an instance in which the 
 elevation of a whole country is actually taking 
 place, unheeded by the busy multitude, and known 
 only by the researches of the natural philosopher. 
 I allude to Scandinavia, which, it is ascertained, is 
 slowly and visibly rising, from Frederickshall, in 
 Sweden, to Abo, in Finland, and even, perhaps, as 
 far as St. Petersburgh ; while the adjacent coast of 
 
66. ELEVATION OF SCANDINAVIA. 105 
 
 Greenland is suffering a gradual depression. The 
 state, therefore, is one of oscillation, the waters 
 appearing to sink at Torneo, and to retain their 
 former level at Copenhagen. The opinion that 
 Sweden is in this state of change, is no new idea ; 
 it was long since noticed by Celsius,* and other 
 Swedish philosophers. Mr. Lyell has twice visited 
 Scandinavia within the last few years, with the view 
 of determining this interesting question ; and has 
 fully convinced himself that certain parts of Sweden 
 are undergoing a gradual rise, to the amount of 
 two or three feet in a century ; while other parts, 
 farther to the south, appear to have experienced no 
 movement.-} 1 He visited some parts of the shores 
 of the Bothnian Gulf, between Stockholm and Gefle, 
 and of the western coasts of Sweden, districts par- 
 ticularly alluded to by Celsius. He examined the 
 marks cut by the Swedish pilots, under the direc- 
 tion of the Swedish Academy of Sciences, in 1820, 
 and found the level of the Baltic, in calm weather, 
 to be several inches lower than the marks, and 
 several feet below those made seventy or a hundred 
 years ago. Similar results were obtained on the 
 side of the ocean, and in both districts the testi- 
 mony of the inhabitants agreed with that of their 
 ancestors, recorded by Celsius. On the shores of 
 the Northern Sea, there are banks of recent shells, 
 
 Illustrations of the Huttonian Theory, p. 436, edit 1822. 
 t Philosophical Transactions. Principles of Geology, Fifth 
 Edition, vol. ii. p. 286. 
 
106 THE WONDERS OF GEOLOGY. LECT. I. 
 
 at various heights, from 10 to 200 feet, and on the 
 side of the Bothnian Gulf, between Stockholm and 
 Gefle, deposits containing fossil shells of the species 
 which now inhabit the brackish waters of that sea. 
 These occur at various elevations, from one to a 
 hundred feet, and sometimes extend fifty miles 
 inland. The shells are partly marine and partly 
 fluviatile ; the marine species are identical with 
 those now living in the ocean, but are dwarfish in 
 size, and never attain the average dimensions of 
 those which live in water sufficiently salt to enable 
 them to reach their full development. The speci- 
 mens before you were collected by Mr. Lyell at 
 Uddevalla, in Sweden, from the summit of cliffs 
 twenty feet above the level of the sea ; they consist 
 of recent marine species, such as inhabit the neigh- 
 bouring waters. 
 
 Of the reality of these changes in the relative 
 level of the land and of the Northern ocean, there 
 cannot exist a doubt ; but the mind is so accus- 
 tomed to associate the idea of stability with the 
 land, and of mutability with the sea, that it may 
 be necessary to offer a few additional remarks on 
 these highly interesting facts. As it is the property 
 of all fluids to find their own level, it is obvious 
 that if the level of the sea be elevated or depressed 
 in any one part, that elevation or depression must 
 influence the whole surface of the ocean, and the 
 level therefore cannot be affected by local causes. 
 But movements of the land may take place, and 
 
66. ELEVATION OF SCANDINAVIA. 107 
 
 the effect extend over whole countries, as in South 
 America, or along lines of coast, as in Sussex, 
 or be confined to a single island, or even to the 
 broken columns of a temple, as at Puzzuoli.* But 
 while the land is rising in the more northern lati- 
 tudes, it appears to be sinking on the shores of the 
 Mediterranean. Breislak mentions -f- that numerous 
 remains of buildings are to be seen in the Gulf of 
 Baiae ; ten columns of granite, at the foot of Monte 
 Nuovo, are nearly covered by the sea, as are the 
 ruins of a palace built by Tiberius in the island of 
 Caprea. Thus, while the level of the sea is becoming 
 lower in the north, it is rising in the Mediterranean ; 
 and as all the parts of the ocean communicate, the 
 sea cannot permanently rise in one part and sink 
 in another, but must rise and fall equally to main- 
 tain its level ; we must therefore consider it as 
 demonstrated, that these changes have proceeded 
 from the elevation and depression of the land. If 
 we bear in mind the insignificance of the masses 
 affected by these operations, as contrasted with the 
 earth itself (see page 14), we may readily conceive 
 that as fissures and inequalities are produced in the 
 varnish of an artificial globe by heat and cold, in 
 like manner the elevation of mountain chains, the 
 rending of extensive tracts of country, and the sub- 
 sidence of whole continents, may be occasioned by 
 
 See Playfair's admirable comments on this geological 
 problem. Illustrations, p. 433. 
 t Playfair. 
 
108 THE WONDERS OF GEOLOGY. LECT. I. 
 
 the expansion and contraction of the materials of 
 which our planet is constructed. 
 
 67. RETROSPECT. In this imperfect sketch of 
 the geological phenomena, which a superficial ex- 
 amination of the surface of the globe presents to 
 our notice, I have doubtless dwelt on several sub- 
 jects which are familiar to many of my auditors. 
 But, as one of our ablest geologists* has remarked, 
 " the teacher of Geology must suppose himself 
 called on to answer questions both concerning the 
 facts of the science and the inferences to be deduced 
 therefrom ; and his instructions will be so much the 
 more successful as he takes these questions in the 
 most natural order of their occurrence, and answers 
 them most completely and satisfactorily. In doing 
 this he is not at liberty to neglect even elementary 
 truths, for if these were passed over in compliment 
 to such as have made progress in the science, those 
 for whose advantage he is especially interested, 
 would be called to the unreasonable task of labour- 
 ing without instruments, and of theorizing without 
 intelligible data." 
 
 From the vast field of inquiry over which our 
 observations have extended, it may be useful to 
 offer a brief summary of the leading principles that 
 have been enunciated, and the facts on which they 
 are founded. By the most profound and sublime 
 investigations of which the human mind is capable, 
 we learn that our earth is one of myriads of 
 * Professor Phillips. 
 
67. RETROSPECT. 109 
 
 spherical bodies, revolving round certain luminaries ; 
 and that these bodies occur in every variety of con- 
 dition, from that of a diffuse luminous vapour, to 
 opaque solid globes like our own. All the mate- 
 rials of which the earth is composed may exist 
 either in a solid, fluid, or gaseous state ; and simply 
 by a change of temperature, or by electro-chemical 
 agency, every substance may undergo a transition 
 from one state to the other. Water existing as ice, 
 fluid, or vapour, and separable into two invisible 
 gases, offers a familiar example of a body constantly 
 exhibiting these changes ; and mercury, of a metal 
 which, although generally fluid, or melted, becomes, 
 when exposed to a very low temperature, a solid 
 mass like silver. The relative position of land and 
 water, and the inequalities on the surface of the 
 earth, are subject to constant changes, which are 
 regulated by certain fixed laws. The principal 
 causes of the degradation of the land are atmo- 
 spheric agencies, variations of temperature, and the 
 action of running water, by which the disintegrated 
 materials of the land are carried into the bed of the 
 ocean. The mud, sand, and other detritus thus 
 produced, are consolidated by certain chemical 
 changes which are in constant activity, both on the 
 land and in the depths of the ocean, and new rocks 
 are thus in the progress of formation. But the 
 conjoint effect of these disintegrating agencies is 
 unremitting destruction of the land ; and were there 
 no conservative process, the whole of the dry land 
 
110 THE WONDERS OF GEOLOGY. LECT. I. 
 
 would disappear, and the earth be covered by one 
 vast sheet of water. The globe, however, possesses 
 an internal source of heat, and whether this heat 
 exist as a central nucleus of high temperature, or as- 
 medial foci, whether it be dependent on the assumed 
 original nebulous state of the earth, or produced 
 by electro-magnetic forces acting on the mineral 
 substances contained in the interior of our planet, 
 does not affect the present inquiry. This internal 
 heat, however produced, must occasion constant 
 changes in the relative level of the land and water ; 
 elevating whole continents, converting the bed of 
 the sea into dryland, and submerging the dry 
 land into the abyss of the ocean. The volcano and 
 the earthquake are the effects of its paroxysmal 
 energies, the quiet and insensible elevation of the 
 land, of its slow but certain operation. By this 
 antagonist power the accumulation of the spoils of 
 the land, which the rivers, waves, and currents 
 have carried into the bed of the ocean, are again 
 brought to the surface, and form the elements of 
 new islands and continents ; and by the organic 
 remains discovered in these strata, we trace the 
 nature of the countries from whence these spoils 
 were derived. In the deltas and estuaries of modern 
 times, in the detritus accumulating in the beds of 
 the ocean, in the recent tracts of limestone form- 
 ing on the sea-shores, beneath the cooled lava 
 currents erupted from existing volcanoes, the re- 
 mains of man and of his works, and of the animals 
 
67. RETROSPECT. HI 
 
 and plants which are his contemporaries, are found 
 imbedded. 
 
 The dynamical effects of elevation appear to be 
 referable to three great divisions: 1. The gradual 
 raising up of ridges through large spaces of the 
 earth's- crust, and the consequent production of 
 longitudinal fissures and lines of volcanic vent. 
 2. The long continued protrusion and eruption of 
 igneous rocks along such lines of vent ; and 3. Local 
 and partial eruptions and protrusions, producing 
 valleys of elevation, dislocations of the strata, and 
 other phenomena that terminate in ordinary volcanic 
 action.* 
 
 Such are the deductions derived from the phe- 
 nomena which have been submitted to our exami- 
 nation. 
 
 To the mind previously uninstructed in geological 
 science, I am ready to acknowledge that to attribute 
 mutability to the rocks and the mountains, must 
 appear as startling and incredible, as did the astro- 
 nomical doctrines of Galileo to the people of his 
 time. But the intelligent observer, whose atten- 
 tion has been directed to the facts laid before him 
 even in this brief survey, cannot, I conceive, refuse 
 his assent to the inferences thus cautiously obtained. 
 As we proceed in our investigation, we shall find 
 that from the earliest period of the earth's physical 
 history, its surface has been subject to incessant 
 fluctuation ; and as the land has been the theatre 
 * Proceedings of the Geological Society, vol. ii. p. 67. 
 
112 THE WONDERS OF GEOLOGY. LECT. I. 
 
 of perpetual mutation, that element, which has 
 hitherto been considered as the type of mutability, 
 can alone be regarded as having undergone no 
 change. This idea is finely embodied by Lord 
 Byron in the following sublime apostrophe to the 
 Ocean, with which I will conclude this discourse. 
 
 " Thy shores are empires, changed in all save thee 
 Assyria, Greece, Rome, Carthage, what are they ? 
 Thy waters wasted them while they were free, 
 And many a tyrant since ; their shores obey 
 The stranger, slave, or savage ; their decay 
 Has dried up realms to deserts : not so thou, 
 Unchangeable, save to thy wild waves' play 
 Time writes no wrinkle on thine azure brow 
 Such as Creation's dawn beheld, thou rollest now .'" 
 
LECTURE II. 
 
 1. Introductory observations. 2. Extinction of animals. 3. Animals 
 extirpated by human agency. 4. The apteryx australis. 5. The dodo. 
 6. The Irish elk. 7. Epoch of terrestrial mammalia. 8. Character 
 of the ancient alluvial deposits. 9. Classification of mammalian re- 
 mains. 10. Comparative anatomy. 11. Adaptation of structure in 
 animals. 12. Osteological characters of the carnivora. 13. Structure 
 of the hcrbivora. 14. Structure of the rodentia, or gnawers. 15. 
 General inferences. 1C. Fossil bones. 17. Fossil elephants, or mam- 
 moths. 18. Mammoth and rhinoceros in ice. 19. Teeth of recent, 
 and fossil elephants. 20. The mastodon. 21. Mastodons from the 
 Burmese empire. 22.. The sivatherium. 23. The megatherium. 24. 
 The megalonyx. 25. The sloth. 26. Fossil hippopotamus, rhinoceros, 
 horse, &c. 27. The dinotherium. 28. Fossil carnivora in caverns. 
 29. Cave of Gaylenreuth. 30. Forster's Hohle. 31. Bone caverns in 
 England. Kirkdale cave. 32. Diseased bones of carnivora found 
 in caves. 33. Human bones, and works of art in caverns. 34. Osseous 
 breccia, or bone conglomerates. 35. The rock of Gibraltar. 36. Osseous 
 breccia of Australia. 37. Retrospect. 
 
 1. INTRODUCTORY OBSERVATIONS. In the pre- 
 vious lecture we took a comprehensive view of 
 the actual physical condition of the surface of our 
 planet, and of the nature and results of the prin- 
 cipal agents by which the land is disintegrated and 
 renewed. We found in the modern fluviatile and 
 marine deposits, that the remains of man, of works 
 of art, and of the existing races of animals, were 
 preserved. In every step of our progress, the grand 
 law of nature, alternate decay and renovation, was 
 exemplified in striking characters whether in the 
 
114 THE WONDERS OF GEOLOGY. Leer. II. 
 
 regions of eternal snow, or in torrid climes in the 
 rocks and mountains, or in the verdant plains by 
 the agency of heat, or by the effect of cold of 
 drought, or of moisture of steam, or of vapour 
 by the abrasion of torrents and rivers by inunda- 
 tions of the ocean or by volcanic eruptions still 
 the work of destruction, in every varying character, 
 was apparent. And on the other hand we perceived 
 that amidst all these processes of decay and deso- 
 lation, perpetual renovation was at the same time 
 going on, and that Nature was repairing her ruins, 
 and accumulating fresh materials for new islands 
 and continents ; and that innumerable living in- 
 struments were employed to consolidate, and build 
 up the rocky fabric of the earth ; and that even the 
 most terrific of physical phenomena, the earthquake, 
 and the volcano, were but salutary provisions of the 
 Supreme Cause, by which the harmony and integrity 
 of our planet were maintained and perpetuated. 
 The occurrence of human skeletons in modern 
 limestone of coins and works of art in recent 
 breccia and the preservation of the bones of ex- 
 isting species of animals, and of the leaves and 
 branches of vegetables, in the various deposits that 
 are in progress, incontestably prove that enduring 
 memorials of the present state of animated nature 
 will be transmitted to future ages. When the beds 
 of the existing seas shall be elevated above the 
 waters, and covered with woods and forests when 
 the deltas of our rivers shall be converted into 
 
2. EXTINCTION OF ANIMALS. 115 
 
 fertile tracts, and become the sites of towns and 
 cities we cannot doubt that in the materials, ex- 
 tracted for their edifices, the then existing races of 
 mankind will discover indelible records of the phy- 
 sical history of our times, long after all traces of 
 those^ stupendous works, upon which we vainly 
 attempt to confer immortality, shall have disap- 
 peared. But we must now proceed, and pass from 
 the ephemeral productions of man, to the enduring 
 monuments of nature from the coins of brass and 
 silver, to the imperishable medals on which the past 
 events of the globe are inscribed from the moulder- 
 ing ruins of temples and palaces, to the examination 
 of the mighty relics, which the ancient revolutions 
 of the earth have entombed. 
 
 2. EXTINCTION OF ANIMALS. Before entering 
 upon the consideration of the geological phenomena, 
 which belong to the period immediately antecedent 
 to the present, it will be necessary to notice one of 
 the most remarkable facts which geological inves- 
 tigations have established, namely, the entire ob- 
 literation of certain genera of animals and plants. 
 The fluctuating state of the earth's surface, with 
 which our previous inquiries have made us familiar, 
 will have prepared us for the disappearance of some 
 species of animals ; and here another law of the 
 Creator is manifest. Certain races of living beings, 
 suitable to peculiar conditions of the earth, appear 
 to have been created ; and when those states became 
 no longer favourable for the continuance of such 
 i 2 
 
HG THE WONDERS OF GEOLOGY. LECT. II. 
 
 types of organization, according to the natural laws 
 by which the conditions of their existence were 
 determined, the races disappeared, and were pro- 
 bably succeeded by new forms. 
 
 The extinction of whole genera of animals and 
 plants has no doubt depended on many causes- In 
 the earlier ages, the changes of temperature, and the 
 rapid mutations of land and water, were probably 
 the principal agents of destruction ; but since man 
 became the lord of the creation, his necessities and 
 caprice have occasioned the extirpation of whole 
 tribes of animals, whose relics are found in the 
 superficial strata, with those of species concerning 
 which both history and tradition are silent. 
 
 In this country the beaver, wolf, hyena, bear, &c. 
 are examples of species which, although extinct in 
 Great Britain, still exist elsewhere; while the mam- 
 moth, and the Irish elk, whose remains occur in 
 our alluvial deposits, are both extinct ; the latter 
 was unquestionably extirpated by the early inha- 
 bitants of these islands. The obliteration of certain 
 forms of organization, is therefore clearly dependent 
 on a law in the economy of nature which is still 
 in active operation ; and I shall proceed to notice 
 the connecting links between the actually existing 
 species, and those which are blotted out from the 
 face of the earth. 
 
 3. ANIMALS EXTIRPATED BY HUMAN AGENCY. 
 That the extinction of many of the existing races 
 of animals must soon take place, from the immense 
 
4. APTERYX AUSTRALIS. 117 
 
 destruction occasioned by man, cannot admit of 
 doubt. In those which supply fur, a remarkable 
 proof of this inference is cited in a late number of 
 the American Journal of Science. " Immediately 
 after South Georgia was explored by Captain Cook, 
 in 1771, the Americans commenced carrying seal- 
 skins from thence to China, where they obtained 
 most exorbitant prices. One million two hundred 
 thousand skins have been taken from that island 
 alone, since that period ; and nearly an equal number 
 from the Island of Desolation ! The numbers of the 
 fur-seals killed in the South Shetland Isles (S. lat. 
 63,) in 1821 and 1822, amounted to three hundred 
 and twenty thousand. This valuable animal is now 
 almost extinct in all these islands." From the most 
 authentic statements it appears certain that the fur 
 trade must henceforward decline, since the advanced 
 state of geographical science shows that no new 
 countries remain to be explored. In North America 
 the animals are slowly decreasing from the perse- 
 vering efforts, and the indiscriminate slaughter, 
 practised by the hunters, and by the appropriation 
 to the use of man, of those forests and rivers which 
 once afforded them food and protection. They 
 recede with the aborigines before the tide of civi- 
 lization. 
 
 4. THE AFTERYX AUSTRALIS. An extra- 
 ordinary bird, a native of New Zealand, of which 
 but few living individuals are known to naturalists, 
 appears to be on the point of extinction ; it is the 
 
118 THE WONDERS OF GEOLOGY. LECT. II. 
 
 Apteryx Australia, so called from being destitute of 
 wings. The only known specimen was figured and 
 described by Dr. Shaw, and is now in the collection 
 of Lord Stanley. It has lately been examined by 
 
 TAB. 16. APTERYX ACSTRALIS. 
 
 Mr. Yarrell, by whom the characters of the skeleton 
 have been correctly ascertained. This bird is of a 
 greyish brown colour, and has neither wings nor 
 tail. The beak is slightly curved, and the nasal 
 apertures, instead of opening at the base, as in birds 
 in general, and especially in those of a similar con- 
 formation of beak, which is adapted for respiration 
 while immersed in mud or water, is placed at the 
 apex. The eyes are very small. The feathers are 
 long and loose, like those of the emu, but each 
 plume has only a single shaft.* 
 
 Since the former edition of this work, three or four dead 
 specimens of the apteryx have been brought from New Zealand 
 to this country. Mr. Gould states that it is a very rare bird, 
 and that its nocturnal habits render it difficult to be obtained. 
 Its skin is in much request among the New Zealand chiefs, to 
 
5. THE DODO. 119 
 
 5. THE DODO (Didus ineptus). A remarkable 
 instance of the extirpation of a peculiar type of 
 organization is afforded by the dodo, which has 
 been annihilated, and become a denizen of the fossil 
 kingdom, almost before our eyes. The dodo was 
 a bird of the gallinaceous tribe, larger than a 
 turkey, which abounded in the Mauritius and ad- 
 jacent islands, when those countries were first 
 
 TAB. 17. THE DODO. 
 
 colonized by the Dutch, about two centuries ago. 
 This bird formed the principal food of the in- 
 habitants, but it was found to be incapable of do- 
 mestication, and its numbers therefore soon became 
 
 ornament their war dresses. Captain Syraonds also mentions 
 the apteryx as frequenting Cloudy Bay, and affording excellent 
 sport to the hunters, to whom it is of great value, on account 
 of its feathers, which are held in high estimation among the 
 natives. 
 
120 THE WONDERS OF GEOLOGY. LECT. II. 
 
 sensibly diminished. Scuffed specimens were pre- 
 served in the museums of Europe, and paintings 
 of the living animal are still extant in the Ash- 
 molean Museum at Oxford, and in the British 
 Museum. But the dodo is now extinct it is 
 no longer to be found in the isles where it once 
 flourished ; and even all the stuffed specimens are 
 destroyed. The only relics that remain, are the 
 head and foot of an individual in the Ashmolean, 
 and the leg of another in the British Museum. To 
 render this illustration complete, the bones of the 
 dodo have been found in a tufaceous deposit, be- 
 neath a bed of lava, in the Isle of France ; so that 
 if the remains of the recent bird already alluded to, 
 had not been preserved, these fossil relics would 
 have constituted the only proof that such a creature 
 had ever existed on our planet. 
 
 6. THE IRISH ELK, or CERVUS MEGACEROS. 
 (elk with great antlers.) The shell marls of Ireland 
 also afford evidence of the existence of an animal, 
 which, like the dodo, was once cotemporaneous 
 with the human species, but is now altogether 
 extinct, the last individual of the race having, in 
 all probability, been destroyed by man. Its re- 
 mains commonly occur in the beds of marl beneath 
 the peat-bogs, which are apparently, like those of 
 Scotland, the sites of ancient lakes. In Curragh, 
 immense quantities of the bones of the elk lie within 
 a small space, as if the animals had assembled in a 
 herd : the skeletons appear to be entire, and the 
 
6. THE IRISH ELK. 121 
 
 nose is elevated, the antlers being thrown back on 
 the shoulders, as if the creatures had sunk in a 
 morass, and been suffocated. Remains of the elk 
 occur also in marl and gravel, in many parts of Eng- 
 land, France, Germany, and Italy. This enormous 
 ruminant very far exceeded in magnitude any living 
 species. The skeleton is upwards of ten feet high 
 from the ground to the highest point of the antlers, 
 which are palmated, and are from ten to fourteen 
 feet from one extremity to the other. The museum 
 of the late eminent anatomist, Joshua Brookes, 
 which, to the disgrace of the government of this 
 country, was suffered to be dispersed, contained a 
 magnificent pair, measuring eleven feet in expanse, 
 which are now in my collection. Skulls have been 
 found without horns, and these probably belonged 
 to females. The average weight of the skull and 
 antlers is computed at three quarters of a hundred- 
 weight ; they are generally in a fine state of preser- 
 vation, of a dark brown colour, with here and there 
 a bluish incrustation of phosphate of iron, like those 
 of the deer from Lewes Levels. The elk shed its 
 horns, and probably, like existing species, annually. 
 Professor Jameson, Mr. Weaver, and others, have 
 clearly proved that this majestic creature was coeval 
 with man. A skull was discovered in Germany, 
 associated with urns and stone hatchets ; and in 
 the county of Cork, a human body was exhumed 
 from a wet and marshy soil, beneath a bed of peat 
 eleven feet thick; the body was in good preser- 
 
122 THE WONDERS OF GEOLOGY. LECT. II. 
 
 ration, and enveloped m a deer skin covered with 
 hair, which there is every reason to conclude was 
 that of the elk. A rib of the elk has also been 
 found, in which there is a perforation, that evidently 
 had been formed by a pointed instrument while the 
 animal was alive, for there is an effusion of callus 
 or new bony matter, which could only have resulted 
 from something remaining in the wound for a con- 
 siderable period ; such an effect, indeed, as would 
 be produced by the head of an arrow or spear.* 
 There is, therefore, presumptive evidence that the 
 race was extirpated by the hunter-tribes who first 
 took possession of these islands. 
 
 Beds of gravel and sand, containing recent marine 
 shells and bones of the Irish elk, have been ob- 
 served by Dr. Scouler in the vicinity of Dublin, at 
 an elevation of two hundred feet above the level of 
 the sea. It is therefore manifest that this extinct 
 quadruped, although found in peat-bogs and mo- 
 rasses at a comparatively recent period, must have 
 been an inhabitant of Ireland antecedently to some 
 of the last changes in the relative position of the 
 land and water. The discovery of a vast number 
 of skeletons of the elk in the small area of the Isle 
 of Man, seems to indicate a great alteration in 
 the extent of land and sea ; for it is difficult to 
 conceive that such herds of this gigantic race could 
 exist in so limited a district ; and it is therefore 
 probable that the island was separated from the 
 * Jameson's Cuvier. 
 
7,8. EPOCH OF GIGANTIC MAMMALIA. 123 
 
 main land at no remote geological period, by subsi- 
 dences commensurate with the elevation of which 
 Ireland affords such decisive evidence.* 
 
 In the remarkable examples just cited, we have 
 an interesting transition from the recent to the lost 
 types of animal existence. 1st, Species extinct in 
 the British islands, but still living in other coun- 
 tries. 2dly, Animals which have been entirely 
 destroyed within the last few centuries. Lastly, 
 Species that were blotted out from the face of the 
 earth by the early races of mankind. 
 
 7. EPOCH OF TERRESTRIAL MAMMALIA. We 
 
 must now advance another step in the history of 
 the past, and proceed from the consideration of 
 what is known, to that which is unknown ; the sub- 
 sequent divisions of this discourse will be restricted 
 to the geological phenomena of the period imme- 
 diately antecedent to the present ; a period in which 
 the earth appears to have teemed with enormous 
 mammalia, and with which but few species of the 
 existing races were associated. Thus while the 
 present may be termed the modern or human 
 epoch, that which forms the immediate subject of 
 our investigation may be designated the epoch of 
 gigantic mammalia* 
 
 8. CHARACTER OF THE ANCIENT ALLUVIAL 
 DEPOSITS. " When the traveller," says Cuvier, 
 " passes over those fertile plains, where the peaceful 
 
 * Address of Charles Lyell, Esq. President of the Geological 
 Society of London, 1837. 
 
124 THE WONDERS OF GEOLOGY. LECT. II. 
 
 waters preserve, by their regular courses, an abun- 
 dant vegetation, and the soil of which is crowded by 
 an extensive population, and enriched by flourishing 
 cities, which are never disturbed but by the ravages 
 of war, or the oppression of despotism, he is not 
 inclined to believe that nature has also had her 
 intestine wars, and that the surface of the globe has 
 been overthrown by various revolutions and cata- 
 strophes. But his opinions change as he penetrates 
 into that soil at present so peaceful ; or as he ascends 
 the hills which bound the plains. His ideas expand, 
 as it were, with the prospect; and so soon as he 
 as-cends the more elevated chains, or follows the beds 
 of those torrents which descend from their summits, 
 he begins to comprehend the extent and grandeur 
 of those physical events of ages long past. Or if 
 he examine the quarries on the sides of the hills, or 
 the cliffs which form the boundaries of the ocean, 
 he there sees, in the displacement and contortion of 
 the strata, and in the layers of water-worn materials, 
 teeming with the remains of animals and plants, 
 proofs that those tranquil plains, those smooth un- 
 broken downs, have once been at the bottom of the 
 deep, and have been lifted up from the bosom of 
 the waters; and everywhere he will find evidence 
 that the sea and the" land have continually changed 
 their place." 
 
 In almost every part of the world, beneath the 
 modern alluvial soil, the nature and character of 
 which were described in the former lecture, exten- 
 
9. CLASSIFICATION OF MAMMALIAN REMAINS. 125 
 
 sive beds of gravel, clay, and loam, are found spread 
 over the plains, or on the flanks of the mountain 
 chains, or on the crests of ranges of low elevation ; 
 and in these accumulations of water-worn mate- 
 rials, are immense quantities of the bones of large 
 mammalia.* These remains belong principally to 
 animals related to the elephant, as the mammoth, 
 mastodon, &c., and to various species of hippopo- 
 tamus, rhinoceros, horse, ox, deer, and many of 
 extinct genera ; while in caverns and fissures of 
 rocks filled with calcareous breccia, the skeletons 
 of tigers, boars, hyenas, and other carnivorous ani- 
 mals, are imbedded. Fossil bones of this kind 
 exist, in such abundance, all over Europe, Asia, 
 and America, that it is impossible to enumerate 
 the localities ; they are found alike in the tropical 
 plains of India, and in the frozen regions of Siberia ; 
 while there is no considerable district of Great 
 Britain in which some traces of these remains do 
 not occur. 
 
 9. CLASSIFICATION OF MAMMALIAN REMAINS. 
 Dr. Buckland considers these remains as refer- 
 able to four divisions. 
 
 First. Land animals, drifted into estuaries or seas, 
 and associated with marine shells, such as those 
 found in the Sub-Apennine formations ; in the beds 
 of gravel, sand, &c. provincially termed crag, in 
 
 * The term diluvium is commonly applied to these ancient 
 alluvial beds ; they are the newer pliocene in the classification 
 of Mr. Lyell, as we shall hereafter explain. 
 
126 THE WONDERS OF GEOLOGY. LECT. II. 
 
 Norfolk and Suffolk ; loam and chalk conglomerate 
 in Brighton cliffs ; and in clay off Harwich and 
 Herne Bay, and on the coast of Western Sussex. 
 
 Secondly. Terrestrial quadrupeds, imbedded with 
 fresh-water shells ; in strata that have been formed 
 during the same epoch as the above, at the bottom 
 of fresh-water lakes ; such are the fossil bones of 
 the lacustrine marls of the Val d' Arno. 
 
 Thirdly. Similar remains in superficial detritus, 
 spread over the surface of rocks of all ages ; as in 
 beds of gravel near London ; Petteridge Common, 
 Surrey ; near Eastbourn, Sussex, &c. 
 
 Fourthly. Osseous remains of carnivorous and 
 herbivorous animals in caverns and fissures of rocks 
 which formed part of the dry land, during the later 
 period of the same epoch. The caverns of Gaylen- 
 reuth, Kirkdale, &c. are examples. 
 
 Lastly. The relics in the osseous breccias that 
 occur in fissures of limestone on the shores of the 
 Mediterranean, in the Ionian Isles, in the rock of 
 Gibraltar, at Plymouth, and in the Mendip hills.* 
 
 Before I direct your attention to the fossils before 
 us, which have been collected from the alluvial de- 
 posits under examination, and from various local- 
 ities, it will be necessary to review the leading 
 principles of that science which explains the struc- 
 ture of animal existence. Thus while in our pre- 
 ceding investigations we referred to Astronomy to 
 dissipate the obscurity which shrouded the earliest 
 * Dr. Buckland's Bridgwater Essay, p. 94. 
 
10. COMPARATIVE ANATOMY. 127 
 
 history of our planet, we are now led to that impor- 
 tant department of natural knowledge, Comparative 
 Anatomy, to enable us to restore the lost forms of 
 animal existence. I shall therefore explain the 
 mode of induction employed by the scientific ob- 
 server, in his investigation of the fossil remains of 
 animals, by which he is enabled to ascertain the 
 structure and habits of those creatures which have 
 long since disappeared from the face of the 
 earth. 
 
 10. COMPARATIVE ANATOMY. To a person 
 uninstructed in this science, the specimens before 
 us would appear a confused medley of bones and 
 of osseous fragments, impacted in solid stone ; and 
 the only knowledge he could derive from their ex- 
 amination would be the fact, that the stone was 
 once in the state of sand or mud, in which, while 
 soft, the bones had become imbedded. But in vain 
 would he seek for further information from these 
 precious historical monuments of Nature ; to him 
 they would appear as unintelligible as were the 
 hieroglyphics of Egypt, before Young and Cham- 
 pollion explained their mysterious import. It is 
 only by an acquaintance with the structure of the 
 living forms around us, and by acquiring an inti- 
 mate knowledge of their osseous frame-work or 
 skeleton, that we can hope to decipher the hand- 
 writing on the rock, obtain a clue to guide us 
 through the labyrinth of fossil anatomy, and con- 
 duct to those interesting results, which the genius 
 
128 THE WONDERS OF GEOLOGY. LECT. II. 
 
 of the immortal Cuvier first taught us how to 
 acquire. And here it will be necessary to enter 
 upon the consideration of those beautiful principles 
 of the co-relation of structure in organized beings, 
 which were first announced by that illustrious phi- 
 losopher. 
 
 11. ADAPTATION OF STRUCTURE IN ANIMALS. 
 The organs of every animal, observes M. Cuvier, 
 may be considered as forming a machine, the parts 
 of which are mutually dependent on each other, 
 and exquisitely adapted for the functions they are 
 destined to perform ; and such is the intimate rela- 
 tion of the several organs, that any variation in one 
 part, is constantly accompanied by a corresponding 
 modification in another. This mutual adaptation 
 of the several parts of the animal fabric is a law of 
 organic structure, which, like every other induction 
 of physical truth, has only been established by 
 patient and laborious investigation. It is by the 
 knowledge of this law that we are enabled to re- 
 assemble, as it were, the scattered remains of the 
 beings of a former state of the globe, to determine 
 their place in the scale of animated nature, and 
 to reason on their structure, habits, and economy, 
 with as much clearness and certainty, as if they 
 were still living and before us. I will demonstrate 
 this proposition by a few examples. Of all the solid 
 parts of the animal structure the most obviously 
 mechanical are the jaws and teeth ; and as we know 
 in each instance the operations they are intended to 
 
12. OSTEOLOGICAL CHARACTER OF CARNIVORA. 129 
 
 perform, they afford the most simple and striking 
 illustration of the principles above enunciated. 
 
 TAB. 18. SKULL OF THE BENGAL TIGER. 
 
 12. OSTEOLOGICAL CHARACTERS OF THE CAR- 
 NIVORA. If we examine the jaws of the skulls 
 before us, those of a Bengal tiger, and of a cat, we 
 perceive that there are cutting teeth in front, 
 sharp fangs on the sides, and molar, bruising, or 
 crushing teeth, in the back part. The molar rise 
 into sharp lanciform points, and over-lap each other 
 in the upper and lower jaw, like the edges of a pair 
 of shears ; and the teeth are externally covered 
 with a thick crust of enamel. This is evidently 
 an apparatus for tearing and cutting flesh, or for 
 cracking bones ; but is not suited for grinding the 
 stalks or seeds of vegetables. The jaws fit together 
 by a transverse process, which moves in a corre- 
 sponding depression in the skull, like a hinge 
 (Tab. 18) ; they open and shut like shears, but 
 admit of no grinding motion ; this, then, is such an 
 articulation as is adapted for a carnivorous animal ; 
 and every part of this instrument is admirably 
 fitted for its office. 
 
 K 
 
130 THE WONDERS OF GEOLOGY. LECT. II. 
 
 But all these inimitable adjustments would be 
 lost, were there not levers and muscles to work the 
 
 TAB. 19. SKULL OF A WILD CAT. 
 (Felis Canadensis.) 
 
 jaws, were not each portion of the animal frame 
 adapted to all the other parts, and were not the 
 instincts and appetites of the animal such as are 
 calculated to give to this apparatus its appropriate, 
 movements. Let us reverse the order of the argu- 
 ment, let us assume that the stomach of an animal 
 be so organized as to be fitted for the digestion of 
 flesh only, and that flesh recent, we should find 
 that its jaws would be so constructed as to fit them 
 for devouring live prey, the claws for seizing and 
 tearing it, the teeth for cutting and dividing it, 
 the whole system of its powers of motion for pur- 
 suing and overtaking it, the organs of sense for 
 discovering it at a distance, and the brain endowed 
 with the instinct necessary for teaching the animal 
 how to conceal itself, and lay snares for its victims. 
 
13. STRUCTURE OF THE HERBIVORA. 131 
 
 Such are the general relations of the structure of 
 carnivorous animals, and which every being of this 
 class must indispensably combine in its constitution, 
 or its race cannot exist. But subordinate to these 
 principles, are others connected with the nature 
 and habits of the prey upon which the animal is 
 intended to subsist, and thence result modifications 
 of the details in the forms which arise from the 
 general conditions. Thus, in order that the animal 
 may have the power requisite to carry off its prey, 
 there must be a certain degree of vigour in the 
 muscles which elevate the head ; and thence results 
 a determinate form in the vertebrae or bones from 
 which these muscles originate, and in the back of 
 the head in which they are inserted. That the 
 paws may be able to seize their prey, there must be 
 a certain degree of mobility in the toes, and of 
 strength in the claws, and a corresponding form in 
 all the bones and muscles of the foot. It is un- 
 necessary to extend these remarks, for it will easily 
 be seen that similar conclusions may be drawn with 
 regard to all the other parts of the animal.* In 
 the tiger and the cat we have a familiar illustration 
 of what has been advanced. 
 
 13. STRUCTURE OF THE HERBIVORA. In 
 animals which are destined to live on vegetables we 
 have the same mutual relations ; the sharp fangs of 
 the teeth are wanting, the enamel is not all placed 
 
 * Consult Cuvier's " Theorie de la Terre ;" " Le9ons d' Ana- 
 tomic Comparative ;" " Ossemens Fossiles;" &c. 
 K 2 
 
132 THE WONDERS OF GEOLOGY. LECT. II. 
 
 on the top of the teeth as in the carnivora, but 
 arranged in deep vertical layers, alternating with 
 bony matter; and this arrangement, in all states 
 of the teeth, secures a rough grinding surface, as in 
 the horse and the elephant. The flat molar teeth 
 
 TAB. 20. SKULL OF THJS HORSE. 
 
 are not formed for cutting, but for mastication, 
 and the jaws are loosely articulated together so as 
 to allow of a grinding movement : had the socket 
 and corresponding part of the jaw been the same 
 as in the tiger, the tooth could not have performed 
 its office. Again, I might proceed in the argu- 
 ment, and show the adaptation of the muscles of 
 the head to the apparatus here described; and 
 beginning with the jaw, review the whole animal 
 frame, and demonstrate how all its parts are alike 
 wonderfully constructed and fitted together, to 
 perform the functions necessary for the being to 
 which it belongs. 
 
14. 
 
 STRUCTURE OF THE RODENTIA. 
 
 133 
 
 14. STRUCTURE OF THE RODENTIA, OR GNAW- 
 ERS. In the jaws of an intermediate order of 
 animals, we find new modifications of the same 
 
 TAB. 21. SKULI AND TEETH OF RODENTIA, on GNAWERS. 
 
 Fig. 1. Molar teeth of the upper jaw of a Florida rat (Arvicola Floridana) 
 magnified; seen obliquely. Fig. 2. Left side of the lower jaw, of the 
 natural size. Fig. 3. Skull of the squirrel. 
 
 apparatus. Thus the rodentia, or gnawers, have 
 long sharp cutting teeth, like nippers ; it is by these 
 that the rat can very speedily gnaw a hole through 
 a board, and the squirrel in a nut, in consequence 
 of their exquisite adaptation for these operations. 
 In the skull of the squirrel (Tab. 21, fig. 3) the 
 
134 THE WONDERS OF GEOLOGY. LECT. II. 
 
 front teeth are of enormous size, as compared with 
 the molar, and they lock together in such manner 
 as to render a grinding movement impossible ; a 
 new adjustment has, therefore, been supplied, the 
 lower jaw is so adapted as to work in the skull 
 neither in a transverse nor in a rotatory direction, 
 but lengthwise, like the action of a carpenter using 
 his plane, the teeth moving backwards and forwards, 
 as may be observed in the rabbit while eating its 
 food. The enamel of the molar teeth (see Tab. 21, 
 fig. 1) is placed vertically and transverse to the 
 jaw, so as to form an admirable grinding surface. 
 But this is not the only variation of structure ob- 
 servable in the teeth of these animals. The incisors 
 being implements of constant use, are renewed by 
 continual growth, and there is a special provision 
 for their support in a bent socket. The enamel is 
 unequally distributed round the tooth, being very 
 thin behind and thick in front, by which means the 
 cutting edges are always preserved; for by the very 
 act of gnawing, the hinder part of the incisor wears 
 away quicker than the fore part, and thus a sharp 
 inclined edge, like that of an adze or chisel, is 
 maintained, and which is the very form required 
 in the economy of the animal. The skull of the 
 common rabbit or hare will exemplify these re- 
 marks. 
 
 15. GENERAL INFERENCES. These are but a 
 few examples of those admirable adaptations of 
 means to ends which are observable throughout 
 
15. GENERAL INFERENCES. 135 
 
 the various classes of organized beings : but the 
 limits of a single lecture will not allow me to be 
 more diffuse, and I trust it is unnecessary to offer 
 further remarks, to show that the conclusions of 
 geologists, as to the ancient inhabitants of our 
 globe, are not vague assumptions, as those unac- 
 quainted with the science might suppose, but the 
 legitimate deductions of laborious and patient in- 
 vestigations. A few teeth and bones sometimes 
 but a single relic of this kind are the elements 
 by which the comparative anatomist is enabled, 
 not only to restore the forms of creatures now 
 banished from the face of the earth, but also to 
 ascertain their habits and economy, and even arrive 
 at positive conclusions respecting the nature of the 
 country of which they were once the inhabitants. 
 If we find the remains of animals which lived on 
 vegetables, it follows that there must have been 
 vegetables for their subsistence, and a condition of 
 nature calculated for the growth of vegetable pro- 
 ductions; a soil fitted for their existence, and a 
 country diversified by hills, valleys, and plains, 
 with streams and rivers to carry off its superfluous 
 waters. The same laws, under certain modifica- 
 tions, apply to other classes of beings. In birds, the 
 form of the feet is modified according to the habits 
 of the different orders. In the parrot, (Tab. 22, 
 fig. 3,) the claws are adapted to climb trees and 
 perch on the branches; but in the eagle they are 
 widely different, for its talons are constructed to 
 
136 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. II. 
 
 lacerate and tear its prey, (Fig. 4.) The feet of 
 aquatic birds are formed like a paddle or oar, to 
 
 TAB. 22. DIFFERENT FORMS OF FEET IN BIRHS. 
 
 Fig. 1. Foot of the heron ; Fig. 2. Of the ostrich ; Fig. 3. Of the parrot; 
 Fig. 4. Of the eagle ; Fig. 5. Of the pelican. 
 
 enable them to make their way through the water 
 (Fig. 5) ; those of birds that frequent marshes have 
 a great expansion, like a tripod, that they may move 
 over the unstable surface of the morass (Fig. 1); 
 while in species destined to inhabit sandy deserts, as 
 the ostrich (Fig. 2), the feet present a corresponding 
 change of structure. 
 
 We perceive, therefore, that every vertebrated 
 animal has a solid and durable skeleton, or osseous 
 
16. FOSSIL BONES. 137 
 
 support, formed upon one general plan, but modified 
 in almost endless variety, in the relative magnitude, 
 situation, and aspect of the different parts, so as to 
 adapt itself to the various habits and functions of 
 the diversified forms of animal life. In short, that 
 the Author of nature has by these changes varied 
 the same general fabric in innumerable ways ; be- 
 stowed upon it a thousand different instincts and 
 passions ; adapted it to every element and climate ; 
 and to every possible variety of food and mode of 
 existence. 
 
 From a knowledge of these principles of the co- 
 relation of the different parts of every organized 
 being, which I have thus attempted to explain, we 
 may understand how the scientific observer can 
 reconstruct the entire animal fabric: and we are 
 now prepared to enter upon that department of 
 geology called Palaeontology , or the science which 
 relates to the fossil remains of the beings which 
 inhabited our planet in former ages. 
 
 16. FOSSIL BONES. As the bones are the least 
 perishable parts of the animal structure, they be- 
 come the most frequent, and often the only indica- 
 tions of the zoological characters of the more ancient 
 epochs. Occasionally very delicate parts, such as 
 the tunic of the eye, the membranes of the stomach, 
 and the wings of insects, are preserved in a fossil 
 state, examples of which we shall hereafter adduce. 
 In the older rocks, the bones are generally mineral- 
 ized, and no longer possess the white and glossy 
 
138 THE WONDERS OF GEOLOGY. LECT. II. 
 
 appearance of the recent skeleton ; but those which 
 occur in the superficial gravel, and in caverns, are 
 commonly of a porous and earthy character, like 
 bones that have lost a portion of their animal 
 matter by being buried in a dry and loose soil. 
 
 The animals whose fossil remains I now proceed 
 to describe, may be separated into two classes the 
 HERBIVORA, whose bones occur in the gravel and 
 marl, and the CARNIVORA, which are found in 
 fissures and caverns. 
 
 17. FOSSIL ELEPHANTS, Or MAMMOTHS.* 1 will 
 
 first notice the fossil remains of the animals of the 
 elephantine family, which occur in great abun- 
 dance, and are very generally distributed. In the 
 earlier ages, these colossal bones were supposed to 
 belong to gigantic races of mankind, and hence 
 the tradition of giants possessed by every country 
 in Europe : nor need we smile at the ignorance and 
 credulity of our ancestors, for, not many years since, 
 a fossil tooth of an elephant, which was discovered 
 in digging a well in Brighton, was supposed to be a 
 petrified cauliflower ! In Russia, and more parti- 
 cularly in Siberia, the fossil bones of elephants are 
 found throughout all the low lands, and in the sandy 
 plains, but not in the elevated primary chain of 
 hills, stretching from the borders of Europe to 
 the nearest extreme point of America, and south 
 and north from the base of the mountains of 
 central Asia, to the shores of the Arctic sea. 
 * From the Arabic behemoth, signifying elephant. 
 
IS. FOSSIL ELEPHANTS, OR MAMMOTHS. 139 
 
 Within this space, which is almost equal in extent 
 to the whole of Europe, fossil ivory is everywhere 
 to be found; and the tusks are so numerous, and 
 well preserved, especially in Northern Russia, that 
 thousands are annually collected, and form a lucra- 
 tive article of commerce. In Siberia alone, the 
 remains of a greater number of elephants have been 
 discovered, than are supposed to exist at the pre- 
 sent time all over the world. In a low island in 
 the Frozen Sea (72 north latitude) bones of mam- 
 moths are seen imbedded ; and they also abound in 
 an iceberg on the north-west angle of the American 
 continent, near to Behring's Straits. The tur- 
 quoises of Simone are composed of mammoths' 
 bones impregnated with some metallic oxide. 
 
 18. MAMMOTH AND RHINOCEROS IMBEDDED IN 
 ICE. But the most remarkable fact relating to 
 these remains, is the preservation, not merely of 
 the bones, but of entire animals, with their flesh 
 and skin, in ice-bergs and frozen gravel ! In 1774-, 
 near Vilhoui, the carcase of a rhinoceros was taken 
 from the frozen sand, where it must have been 
 concealed for ages, the soil of that region being 
 always frozen to within a few inches of the surface. 
 The carcase was a complete natural mummy, part 
 of the skin being still covered with long hairs, and 
 forming a warmer covering than that of the African 
 rhinoceros. The discovery of a mammoth, under 
 similar circumstances, is yet more interesting. It 
 appears, that towards the close of the last century, 
 
140 THE WONDERS OF GEOLOGY. LECT. II. 
 
 a Tungusiari fisherman observed in a cliff of ice and 
 gravel, on the banks of the river Lena, a shapeless 
 mass, the nature of which he was unable to deter- 
 mine. In the course of the next year it was more 
 visible, and on the third a large tusk was seen 
 projecting from the ice-cliff, and at length became 
 detached. On the fifth year, an early thaw set in, 
 and the entire carcase of a mammoth was exposed, 
 and at length fell upon the ground. It was twelve 
 feet high, and about sixteen feet in length; the 
 tusks were nine feet long. The flesh was in such a 
 state of preservation, that it was devoured as it lay 
 by wolves and bears, and the hunters fed their dogs 
 with the remains. The skin was covered with hair 
 consisting of black bristles, thicker than horsehair, 
 and fifteen inches in length ; of wool of a reddish 
 brown, and hair of a fawn colour ; and with a mane 
 on the neck. Upwards of SOlbs. of hair were col- 
 lected ; specimens of which may be seen in the 
 Hunterian museum, of the College of Surgeons. 
 The ear remained dry and shrivelled ; the brain and 
 even the capsule of the eye were preserved ! the 
 bones and part of the integuments, and a consider- 
 able quantity of the hair, are in the Museum of 
 Natural History at St. Petersburgh. The accom- 
 panying sketch (Tab. 23) represents the skeleton 
 in its present state. 
 
 The occurrence of large mammalia, in latitudes 
 where but few forms of animal life can now possibly 
 find the means of subsistence, is a fact of so much 
 
f 19. MAMMOTH IMBEDDED IN ICE. 141 
 
 interest, that I must indulge in a few additional 
 remarks. The existing elephants belong to two 
 species, namely, the African, which occurs as far 
 south as the Cape of Good Hope, and the Asiatic, 
 
 TAB. 23. MAMMOTH FOUND IMBEDDED IN FROZEN GRAVEL IN 
 
 SIBERIA. 
 (Twelve feet high, and sixteen feet long.) 
 
 which is limited to 31 north latitude. They are 
 distinguished by certain characters ; but those which 
 more especially relate to our present inquiry, are 
 the peculiarities of the teeth. 
 
 19. TEETH OF RECENT, AND FOSSIL ELEPHANTS. 
 The teeth of animals are formed of three distinct 
 substances, which are variously disposed in different 
 orders, according to the habits and economy of the 
 species ; a fact to which I alluded when treating of 
 the anatomical character of those of the rodentia, &c. 
 The nucleus of the tooth is composed of a bony 
 matter, consisting almost entirely of phosphate of 
 
142 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. II. 
 
 lime, with albumen, and gluten ; it is called ivory. 
 This central portion of the tooth is covered by the 
 enamel, a substance which is still more dense, and 
 of a fibrous structure, and so hard as to strike fire 
 with steel. In human teeth, the enamel covers the 
 whole external surface, and the ivory forms the 
 internal part. In herbivorous animals the enamel 
 and ivory are intermixed ; and there is in some 
 genera, a third substance called crusta petrosa, 
 
 TAB. 24. TEETH OF RECENT AND FOSSIL ELEPHANTS. 
 
 Fig, 1 . Fossil tooth of an elephant from Brighton cliff, partially water-worn. 
 Fig. 2. Crown of a tooth of the African elephant. Fig. 3. Grinding 
 surface of a tooth of the mammoth, or fossil elephant. Fig. 4. Grinding 
 surface of the Asiatic elephant. 
 
 which is a kind of yellowish, opaque ivory. These 
 three substances enter into the composition of the 
 
19. TEETH OP ELEPHANTS. 143 
 
 teeth of the elephant, and their intermixture is 
 apparent on the masticating surfaces ; they are dif- 
 ferently disposed in the two species. In the African 
 elephant (Tab. 24, fig. 2,) the worn surface of the 
 molar teeth presents a series of lozenge-shaped lines 
 of enamel, having the ivory on the inner margin 
 of the ridges, and being surrounded by the crusta 
 petrosa. In the Asiatic species (fig. 4) the enamel 
 forms narrow transverse bands ; and the tooth of 
 the mammoth, or fossil elephant, (figs. 1 and 3,) has 
 an analogous, but somewhat different distribution. 
 It is obvious that the structure here exhibited, is 
 fitted for the grinding of vegetables ; for the three 
 substances, being of different degrees of hardness, 
 produce by their unequal wearing, a constant rough 
 surface for trituration.* The elephant has but four 
 teeth in each jaw ; the deficiency of prehensile 
 teeth being supplied by that wonderful organ, the 
 trunk. The teeth found in a fossil state, appear to 
 be distinct from either of the recent species ; but 
 they are more nearly related to the Indian or Asia- 
 tic, than to the African, as you may observe by 
 these specimens from Siberia, India, North Ame- 
 rica, and the cliffs on the Sussex coast. In some 
 examples the teeth are water- worn, but most com- 
 monly very perfect, and exhibit but few marks of 
 attrition. From a careful review of the characters 
 of the fossil elephant, or mammoth of Siberia, 
 
 * See Dr. Roget's Bridgwater Treatise, for a lucid and inte- 
 resting Essay on the teeth of various animals. 
 
144 THE WONDERS OF GEOLOGY. LECT. II. 
 
 Cuvier determined th^t the species was now ex- 
 tinct; that the structure of the teeth, configuration 
 of the skull, and the hairy and woolly skin, proved 
 that it was adapted to live in a colder climate than 
 that in which the Asiatic species could exist ; and 
 he inferred that the animals originally inhabited the 
 countries where their remains are now found im- 
 bedded ; and that the preservation of the carcases 
 in ice, showed that the change in the temperature 
 of the climate was sudden, and has since remained 
 unaltered. 
 
 Mr. Lyell offers an ingenious solution of this 
 difficult problem. He supposes that a large region 
 of central Asia, perhaps the southern half of Siberia, 
 may have enjoyed a climate mild enough to have 
 admitted of the existence of the extinct elephants, 
 for vegetation may be found in lat. 40 and 50 
 north ; and from the physical geography of the 
 country, that the whole tract from the mountains 
 to the sea may have been upraised like Sweden, 
 and the refrigeration of the north-east of Asia, 
 and its present physical condition, have been the 
 result. 
 
 My limits will not permit me to dwell at length 
 on other discoveries of fossil elephants, but I will 
 notice a few instances in our own country. On the 
 coasts of Norfolk and Suffolk, so many teeth of 
 elephants have been collected, that the late Mr. 
 Woodward (author of " The Geology of Norfolk ") 
 calculated that they must have belonged to above 
 
19. TEETH OF ELEPHANTS. 145 
 
 500 individuals. At Walton, in Essex, and at 
 Herne Bay, bones and tusks have also been found. 
 But by far the most extraordinary collection of the 
 remains of British fossil elephants that I ever beheld, 
 is in the possession of Mr. Gibson, of Bow, near 
 London; it comprises skulls, tusks, and teeth, from 
 the sucking animal to the adult, in a remarkable 
 state of preservation ; the whole of which were 
 discovered in Essex. In the highly interesting 
 museum of W. D. Saull, Esq. of London, many fine 
 elephantine remains are also preserved. On the 
 western coast of Sussex, and in the neighbourhood 
 of Arundel, Patcham, and Brighton, teeth and 
 bones of elephants have at different times been ex- 
 humed. At Brighton the teeth are found in a 
 deposit of water-worn materials, consisting of loam, 
 chalk, and broken flints, resting on a bed of shingle 
 covering the chalk.* In the conglomerate, of 
 which I have already spoken, (Tab. 15, p. 101,) as 
 well as in the superincumbent deposit, the teeth 
 of elephants, with bones and teeth of a species of 
 deer, horse, and whale, occur, and are associated 
 with marine shells. When these remains were 
 imbedded, this part of the English coast must have 
 joined the opposite shores of France, and have 
 formed the boundary of a bay or estuary, of a 
 country inhabited by large mammalia; for similar 
 fossils are found in a deposit of a like character, 
 along the French coast. 
 
 * See Geology of the South-East of England, p. 32. 
 
146 THE WONDERS OF GEOLOGY. LECT. II. 
 
 20. THE MASTODON. In various parts of North 
 America, there are marshy tracts abounding in salt 
 or brackish waters, which are frequented by deer, 
 and other animals ; a circumstance from which they 
 have acquired the American name of Lick. In 
 these morasses vast quantities of bones of gigantic 
 terrestrial animals have been discovered. The 
 spot most celebrated for these remains in Kentucky, 
 is called Big-bone Lick, and is situated to the 
 south-east of the Ohio, in the midst of a group of 
 low hills, and is traversed by a small stream of 
 brackish water. The bottom consists of a black 
 
 TAB. 25. TOOTH OF THE GREAT MASTODON, FROM THE BANKS OF 
 
 THE HUDSON; WEIGHT 4lbs.* 
 (From Professor Sllliman of Yale College.) 
 
 fetid mud, intermingled with sand, and vegetable 
 
 matter ; and in this bog, bones of great magnitude 
 
 * The drawing is one-third of the diameter of the original. 
 
20. THE MASTODON. 147 
 
 occur in profusion. Some of them are referable 
 to the fossil elephant, but others, as you may 
 observe from the specimens before us, must have 
 belonged to a creature not less gigantic, but with 
 very different characters. 
 
 These teeth are composed of ivory and enamel . 
 only, and the enamel, which is very thick, is spread 
 over the crown of the tooth, which, when unworn, '//. 
 is divided into several transverse tubercles, or 
 processes, each of which is subdivided into two 
 obtuse points ; from this character of the teeth 
 the name of MASTODON (from two Greek words, 
 signifying mammillary teeth,) has been given to 
 the animal to whom they belonged. These teeth 
 have no relation to those of the carnivora ; for 
 although they have an external investment of 
 enamel like those of the tiger, yet they are desti- 
 tute of the longitudinal, serrated, cutting edge ; 
 and in those which are worn, the protuberances 
 become truncated into a lozenge form. The struc- 
 ture is similar to that of the hog and the hippopo- 
 tamus, and is fitted for the bruising and mastication 
 of crude vegetables, roots, and aquatic plants. 
 The bones and teeth of the mastodon have been 
 found throughout the plains of North America, 
 from north of Lake Erie to as far south as Charles- 
 ton, in South Carolina; they have been also dis- 
 covered on the Continent, and in the Crag of 
 Norfolk, in England. Here are examples from 
 the banks of the Ohio, of the Hudson, and from 
 L 2 
 
148 THE WONDERS OF GEOLOGY. LECT. II. 
 
 Big-bone Lick, presented to me by Professor Silli- 
 man : this is an example of a young perfect tooth ; 
 and this of a very old animal, for the grinding surface 
 is almost worn flat by use. These remains are found 
 at moderate depths, with no marks of detrition ; 
 it is therefore evident that the animals must have 
 lived and died in the country where their relics are 
 entombed. The skeletons of the great mastodon 
 found in the bogs of Louisiana are in a vertical 
 position, as if they had sunk in the mire ; and one 
 discovered in New Jersey, forty miles to the south 
 of New York, was bedded in black earth, in the 
 same position, the head being on a level with the 
 surface of the soil. There is an entire skeleton 
 of the mastodon in the museum of Mr. Peale, in 
 Philadelphia, which is fifteen feet long and eleven 
 feet high ; and by this specimen it has been ascer- 
 tained that the great mastodon, or animal of the 
 Ohio, as it has been called, was not unlike the 
 elephant, but somewhat longer and thicker. It 
 had a trunk or proboscis, tusks, and four molar 
 teeth in each jaw, and no incisors. Frdm the nature 
 of its food, as shown by the structure of the teeth, 
 it must have frequented marshy tracts, but it was 
 undoubtedly a terrestrial animal. In the midst of 
 a collection of these bones imbedded in mud, a 
 mass of small branches, grass, and leaves, in a 
 half bruised state, was discovered, and a species 
 of reed, common in Virginia ; the whole appeared 
 to have been enveloped in a sack, probably the 
 
21. MASTODONS OF NORTH AMERICA. 149 
 
 stomach of the animal. In another instance, traces 
 of the trunk or proboscis were observed. The 
 tusks are composed of ivory, and vary in their 
 curvature. The bones of this colossal quadruped 
 are found remarkably fresh and well preserved ; 
 they are generally impregnated with iron, and have 
 evidently been buried in the earth for ages. No 
 living instance of this creature is on record, and no 
 doubt can exist that its race has long been extinct. 
 The Indians believe that men of similar proportions 
 were coeval with the mastodon, and that the Great 
 Spirit destroyed both with his thunder.* There 
 are several species, some of which have been found 
 in North America only, and others in Europe. 
 That eminent philosopher Baron Humboldt dis- 
 covered a tooth of the mastodon near the volcano 
 of Imbaburra, at an elevation of 1,200 fathoms. 
 A very fine skull, with teeth, of the great mastodon, 
 from Big-bone Lick, has lately been placed in the 
 British Museum, and is well worthy your notice 
 when visiting that magnificent collection. This 
 specimen, which was purchased for 150 guineas, 
 consists of the cranium with two perfect grinders, 
 and the sockets of the other two. The length of 
 the skull, from the occiput to the sockets for the 
 tusks, is 36 inches. 
 
 21. MASTODONS FOUND IN THE BURMESE EM- 
 PIRE. I now request your attention to the remains 
 
 * Cuvier. See an admirable English Epitome of Cuvier's 
 Fossil Animals, by Edward Pidgeon, Esq. 1 vol. Svo, 1833. 
 
 
150 THE WONDERS OF GEOLOGY. LECT. II. 
 
 of a species of mastodon which, from the structure 
 of the teeth, fills up, as it were, the interval that 
 separates the mastodon from the elephant ; it 
 
 TAB. 26. FOSSIL TEETH OP THE ELEPHANT AND MASTODON. 
 (One-sixth the diameter of the originals.') 
 
 Fig. 1. Tooth of the fossil Elephant from Big-bone-lick. Fig. 2. Tooth of 
 the Mastodon elephantoides from near Ava. 
 
 has been named by Mr. Clift, the Mastodon ele~ 
 phantoides* (Tab. 26, fig. 2). The teeth, which, 
 together with the fossil bones and wood before us, 
 I owe to the liberality of Mr. Craufurd, present 
 characters very peculiar ; for while their structure 
 is similar to that of the great mastodon, the 
 ridges in which the crown of the teeth is dis- 
 posed, resemble those of the elephant; and the 
 worn surface of the teeth would bear an analogy 
 with that of the grinders of the African elephant. 
 These teeth, together with bones and teeth of the 
 
 * Geological Transactions, vol. ii. new series. 
 
21. MASTODONS IN THE BURMESE EMPIRE. 151 
 
 hippopotamus, rhinoceros, horse, tapir, ox, antelope, 
 hog, gavial, fresh-water turtle, &c. and silicified 
 wood, are part of an extensive collection formed 
 about ten years since by Mr. Craufurd, on his mis- 
 sion to Ava. In descending the river Irawaddi, his 
 steam-boat, owing to the shallowness of the water, 
 ran aground, between Prome and Ava, about 20 
 north latitude, near some petroleum wells, where 
 the bank of the river presents a cliff 80 feet high ; 
 and on the strand were observed masses of petrified 
 wood, and vast quantities of bones. The adjacent 
 country is formed of low, sterile sand-hills, inter- 
 sected by ravines, with beds of gravel, which are 
 here and there cemented into a conglomerate by 
 iron and carbonate of lime, by the process which 
 was explained in the former lecture (p. 64?). Scat- 
 tered over the surface, in some instances lying 
 loose in the sand, and in others half buried, were 
 masses of silicified wood, and fragments of bones, 
 which had become exposed, from the removal of 
 the sand by the winds and rains. The bones, as 
 you may perceive in these incrusted specimens, 
 were more or less invested with a hard crust, which 
 appears to be a mere local concretion, from the 
 consolidation of loose sand by ferruginous and 
 calcareous infiltrations. The natives who assisted 
 Mr. Craufurd's party in collecting these remains, 
 believed that they were the bones of giants who 
 had warred against Vishnu, by whom they had been 
 destroyed. On these interesting discoveries, Dr. 
 
152 THE WONDERS OF GEOLOGY. LECT. II. 
 
 Buckland* calls attention to the remarkable fact, 
 that in the twelve chests full of osseous remains, 
 not a fragment belongs to the elephant, tiger, or 
 hyena, which abound in India ; while evidence is 
 afforded that the extinct mastodon must once have 
 swarmed in the districts bordering on the Irawaddi. 
 22. THE SIVATHERIUM.-)- The flanks of a range 
 of hills belonging to the Sub-Himalaja mountains, 
 between the river Sutlej and the Ganges, are 
 covered by beds of concretionary sandstone, con- 
 glomerate, and loam, bearing a close analogy to 
 those of Ava. These hills, which are called the 
 Sivalik, (from Siva, an Indian deity,) rise to an 
 altitude of from one to three thousand feet above 
 the level of the sea. In these deposits occur im- 
 mense quantities of fossil teeth and bones of the 
 elephant, mastodon, hippopotamus, rhinoceros, elk, 
 ox, horse, deer ; and of several carnivorous animals, 
 crocodiles, gavials, and fresh-water turtles ; with 
 fluviatile shells, and remains of fishes ; an extinct 
 species of monkey r , and of the camel have also been 
 found. These interesting discoveries were made by 
 Captain Proby Cautley, of the Bengal artillery, and 
 Dr. Falconer, who, with an energy and perseverance 
 beyond all praise, have followed out their researches, 
 and transmitted magnificent collections of these re- 
 mains to England. The valuable specimens in my 
 
 * See a Memoir on the Bones from Ava, by Dr. Buckland. 
 Geol. Trans, vol. ii. New Series, 
 f From Siva, an Indian deity, and therion, wild animal. 
 
23. THE S1VATHERIUM. 153 
 
 museum were, with great liberality, sent to me by 
 Captain Cautley; among them you may observe 
 bones and teeth of the same species of mastodon as 
 that which has been found at Ava ; with bones of 
 the horse, rhinoceros, hippopotamus, gavial, and a 
 fine sk'ull of the fossil elephant, with four teeth 
 perfect and in place. But the labours of these 
 naturalists have been yet more richly rewarded by 
 the discovery of the skull, and other parts of the 
 skeleton, of a creature hitherto unknown ; one that 
 forms, as it were, a link between the ruminants and 
 the large pachydermata. From the skull, which is 
 remarkably well preserved, it is ascertained that 
 the animal had four horns, and was furnished with 
 a proboscis ; that it was larger than a rhinoceros, 
 and combined the horns of a ruminant, with the 
 characters of the pachydermata ; the discoverers 
 have named it Sivatkerium. This animal, when 
 living, must have resembled an immense antelope, 
 or gnu ; with a short and thick head, an elevated 
 cranium, crested with two pairs of horns ; the front 
 pair were small, and the hinder large, and set quite 
 behind, as in the aurochs. With the face and 
 figure of the rhinoceros, it must have had small 
 lateral eyes, great lips, and a nasal proboscis ; these 
 inferences have been deduced from certain anato- 
 mical characters exhibited by the fossil bones, but 
 upon which I cannot enlarge. 
 
 23. THE MEGATHERIUM. (Mega, great, and 
 therion, wild beast.) The Pampas, those immense 
 
154 THE WONDERS OF GEOLOGY. LECT. II. 
 
 plains of South America, on the south bank of the 
 river Saladillo, which present a sea of waving grass 
 for 900 miles, are principally composed of alluvial 
 loam and sand, containing fresh-water with marine 
 shells, and were once, like Lewes Levels, a gulf, or 
 arm of the sea. In these alluvial deposits, enormous 
 bones have been frequently discovered. Towards 
 the close of the last century, an almost entire ske- 
 leton of a gigantic animal was dug up, at the depth 
 of 100 feet, in a bed of clay, on the banks of the river 
 Luxor, about four leagues W.S.W. of Buenos Ayres. 
 This skeleton was sent, in 1789, to the museum at 
 Madrid, where it now remains. It is described and 
 figured by Cuvier, under the name of the megathe- 
 rium. In 1832, Sir Woodbine Parish, with con- 
 siderable labour and expense, collected many parts 
 of the skeleton of a similar creature from the Salado ; 
 and actually diverted for a time the river from its 
 course, that he might disinter these precious relics, 
 which he has since deposited in the Hunterian 
 Museum of the Royal College of Surgeons. But, 
 before I enter upon a description of these fossils, it 
 will be requisite to notice the remains of an animal 
 of analogous structure, which has been discovered 
 in the saltpetre caves of Virginia and Kentucky, 
 and which, from the size of the unguical or claw- 
 bones, has been named the megalonyx. 
 
 24. THE MEGALONYX.* I have placed upon the 
 
 * Mega, great ; onyx, claw. See a " Description of the 
 Fossil Bones of the Megalonyx," in Dr. Harlan's Medical and 
 Physical Researches. 
 
24. THE MEGALONYX. 155 
 
 table, models of all the bones which are now pre- 
 served in the museum of Philadelphia, for which I 
 am indebted to an eminent physician and geologist 
 of that city, Dr. S. G. Morton, the author of the 
 most valuable treatise that has appeared on the 
 fossils of the United States.* The late American 
 President, Jefferson, who first described these re- 
 mains, inferred, from the form and magnitude of 
 the claw-bone, that the original was a carnivorous 
 animal of colossal proportions. But Cuvier, by his 
 profound knowledge of the principles of anatomy, 
 determined, from certain characters of the articu- 
 lating surfaces,f that the animal was related to the 
 bradypus, or sloth. I will endeavour briefly to 
 explain to you the mode by which this induction 
 was obtained. The paws or feet, both of the canine 
 and feline tribes, are armed with claws ; in the for- 
 mer, the nails are thick and coarse as in the clog, 
 wolf, &c. and fitted to bear the friction and pressure 
 incident to a long chase ; while in the cat tribe, on 
 the contrary, they are curved and sharp, which 
 qualities are preserved by a peculiar mechanism. 
 The last bone which supports the claw is placed 
 laterally to the penultimate bone, and is so joined 
 to it that an elastic ligament draws it back, and 
 raises the sharp extremity of the claw upwards; 
 
 * Synopsis of the Fossils of the Cretaceous Group of the 
 United States, by S. G. Morton, M.D. &c. 
 
 f That surface of the bone which forms a joint with another 
 bone. 
 
156 THE WONDERS OF GEOLOGY. LECT. II. 
 
 and the nearer extremity of the farthest bone 
 presses the ground in the ordinary running of the 
 animal, while the claw is retracted into a sheath : 
 but when the creature makes a spring and strikes, 
 the claws are uncased by the action of the flexors 
 or bending tendons. In the Bengal tiger, the claws 
 are so sharp and strong, and the arms so powerful, 
 that they have been known to fracture the skull of 
 a man, by a single touch in the act of leaping over 
 him.* A cat affords a familiar illustration of this 
 peculiarity of structure; when pleased, its claws are 
 retracted, and when angry they are thrown out. 
 In the claw of the megalonyx there is no such lateral 
 provision for its retraction, and the point could not 
 have been raised vertically, as in the cat, so as to 
 have permitted it to touch the ground without 
 injury. The articulating surface is double, that is, 
 there is a ridge or spine in the middle, and it must, 
 therefore, have moved like a hinge. 
 
 25. THE SLOTH. There is among recent ani- 
 mals an order called tardigrada, from their feeble 
 power of progression these are the paresseux, or 
 sloths ; which have long toes, and large nails, of a 
 construction similar to those of the fossil. Their 
 nails are folded up, but in a very different manner 
 from those of the cat ; they only enable the animal 
 to walk, in the same way as if our fingers were 
 folded under the palms of the hands. This is a 
 
 * Sir C. Bell. 
 
25. THE SLOTH. 157 
 
 specimen of the bradypus (slow-footed) tridactylus^ 
 (three-toed) from South America, and which is 
 also called the ai, from its peculiar cry. The arms 
 are double the length of the legs, and, from the 
 construction of the limbs, the animal, when it walks, 
 or rather crawls on the ground, is obliged to drag 
 itself along on its elbows. But these creatures are 
 destined to inhabit trees ; their proper element is 
 on the branches, and they can pass from bough to 
 bough, and from tree to tree, with a rapidity which 
 soon enables them to lose themselves in the depths 
 of the forests. They live on the leaves and the 
 young shoots, and unless disturbed, never quit a 
 tree till they have stripped off every leaf. To avoid 
 the labour of a descent, they drop to the ground, 
 previously coiling themselves into a round ball, in 
 which state, while attached to the branch, they may 
 be taken alive. Thus the habits and economy of 
 the sloth point out the necessity for a peculiarity 
 of structure in its nails. The monkey leaps and 
 swings himself from tree to tree, and catches at will 
 the branches or the trunk ; but the sloths do not 
 grasp ; their claws are mere hooks to hang by, and 
 their great strength is in their arms. They never 
 unfix one set of hooks until they have caught a 
 secure hold with the other, thus hanging by their 
 arms and legs, while their bodies are pendant ; and 
 they sleep in the same position. In the bones of 
 the arm of the megalonyx, we find a close analogy 
 with those of the sloths. The humerus, or arm- 
 
158 THE WONDERS OF GEOLOGY. LECT. II. 
 
 bone, has a long internal condyle for the origin of 
 very large muscles to move the enormous claws ; 
 and there is a foramen or opening for the passage 
 of nerves and blood-vessels, to protect them from 
 the pressure to which they would be exposed from 
 the powerful muscular action ; while the radius is 
 so constructed as to allow of a rotatory motion of 
 the arm. With the bones of this animal were 
 found masses of osseous polygonal scales, like 
 mosaic work ; and it is supposed that the original 
 was covered with an armour resembling that of the 
 armadillo. 
 
 I now proceed to the consideration of the mega- 
 therium. This creature was about seven feet high, 
 and nine feet long, and therefore larger than the 
 largest rhinoceros; but this comparison by no means 
 conveys a proper idea of its bulk, since its propor- 
 tions are perfectly colossal, the thigh-bone being 
 three times as large as that of the elephant, and the 
 pelvis or haunch-bone, twice the breadth. It pos- 
 sessed no incisor teeth, and the molars or grinders 
 are seven inches long, of a prismatic form, and, like 
 those of the elephant, composed of ivory, enamel, and 
 crusta petrosa, or cement. They are so formed, that 
 the crown of the teeth always presents two cutting, 
 wedge-shaped, salient angles. As in an adze a plate 
 of steel is placed between two of iron so as to pro- 
 ject in a line, in like manner these teeth have in the 
 centre, a cylinder of ivory, which is protected by a 
 plate of enamel, and has an external coating of 
 
25. THE MEGATHERIUM. 159 
 
 crusta petrosa ; these teeth are, therefore, admirably 
 adapted for cutting and bruising vegetable matter. 
 The entire fore-foot is about a yard in length, and 
 the claws are set obliquely to the ground, like those 
 of the mole ; a position which would render them 
 digging instruments of great power. The pelvis 
 measures five feet in width, and the sacral aperture 
 of the spinal marrow is one foot in circumference ! 
 This enormous size was suitable to the habits of an 
 animal requiring to maintain an upright posture 
 for a considerable time, and to employ its fore-feet 
 in digging. As Dr. Buckland has fully elucidated 
 the structure and habits of this enormous being of 
 the ancient world, and his work is, or ought to be, 
 in every library, I will not dwell on other impor- 
 tant peculiarities in its osteology, but content myself 
 with stating, that the megalonyx and megatherium, 
 were intermediate between the sloths, armadillos, 
 and ant-eaters. The megatherium, with the head 
 and shoulders of the sloth, combined in its legs and 
 feet an admixture of the characters of the armadillo 
 and ant-eater. Both the megalonyx and mega- 
 therium were herbivorous, but they were not 
 capable of climbing, even had there been trees 
 that could have supported their enormous weight : 
 their food, like that of the armadillos, must have 
 consisted of roots and stems of succulent vege- 
 tables, which the peculiar structure of their feet 
 enabled them to dig up with facility. Like their 
 recent types, they are limited in their geographical 
 
160 THE WONDERS OF GEOLOGY. LECT. II. 
 
 distribution to nearly trie same regions of the new 
 world.* 
 
 The skeleton of another colossal quadruped has 
 very recently been discovered near Buenos Ayres, 
 and will shortly be placed in the Hunterian Mu- 
 seum, through the liberality of Sir Woodbine 
 Parish, The original was of the size of an ox, and 
 covered, like the armadillo, by an armour, formed 
 of polygonal scales. From the fluted structure of 
 the teeth, this animal has been named glyptodon, 
 by Professor Owen. 
 
 26. FOSSIL HIPPOPOTAMUS, RHINOCEROS, HORSE, 
 
 &c. With the fossil remains of the mammoth, ele- 
 phant, and other large mammalia, the teeth and 
 bones of several species of hippopotamus, horse, 
 elk, ox, and auroch, are very commonly associated. 
 In the Vale of Arno, in Italy, immense quantities of 
 the teeth and bones of hippopotami are found. On 
 the table before us are specimens from that locality ; 
 as well as molars and incisors of a young animal 
 from Huntingdonshire, presented by Mr. Saull ; and 
 tusks, teeth, and bones, dug up in alluvial marl, at 
 Southbourn, in Sussex. Bones of this animal also 
 occur in alluvial deposits near Rome ; and here are 
 examples, collected by the Marquis of Northampton. 
 Among the objects sent me by Captain Cautley, 
 from India, are several fine portions of jaws, with 
 teeth, belonging to a hippopotamus (H. Sivaliensis.) 
 Several extinct species of hippopotamus have been 
 * See Dr. Buckland's Bridgewater Essay. 
 

 26. FOSSIL HIPPOPOTAMUS. 161 
 
 determined by Baron Cuvier, one of which was not 
 more than half the size of the common species. 
 The bones and teeth of the rhinoceros are con- 
 stantly associated with those of the fossil elephant ; 
 and in this country they occur in superficial gravel 
 and loam : these examples of teeth were discovered 
 in a bed of gravel, on Petteridge common, in Surrey. 
 But the most extraordinary and interesting fact, 
 relating to the fossil rhinoceros, is the discovery of 
 the entire carcass, with the skin, in frozen sand, on 
 the banks of the Wilaji, in Siberia. The head was 
 extremely large, and sustained two very long horns ; 
 it had no incisors ; the body was covered with 
 brown hair, particularly on the limbs ; and the 
 general form of the animal was lower and more 
 compact than the living species. 
 
 The teeth and bones of one or more species of 
 horse, occur very constantly with those of the large 
 extinct pachydermata ; in these examples of the con- 
 glomerated shingle from Brighton cliffs, the coffin, 
 pastern, and cannon bones, as they are termed, 
 are imbedded ; in some instances the cavities of the 
 long bones are filled with crystallized carbonate of 
 lime. 
 
 In addition to the animals we have already 
 noticed, the deposits now under examination con- 
 tain many lost species of ruminants, and of other 
 orders of mammalia. The fossil remains of an 
 animal resembling the musk-ox were found with 
 elephants' bones in Siberia; an extinct species of 
 M 
 
162 THE WONDERS OF GEOLOGY. LECT. II. 
 
 fallow-deer in Scania ; of roe-buck and reindeer in 
 France ; and of gigantic oxen, aurochs,* deer, &c. in 
 our own country. It is worthy of remark, that the 
 fossil pachydermata, such as the elephant, rhino- 
 ceros, &c. belong to genera which inhabit torrid 
 climes, while the ruminants are of those which at 
 the present time are natives of northern latitudes. 
 
 
 TAB. 27. THE DINOTHERIUM. 
 
 27. THE DINOTHERIUM. f I shall conclude my 
 remarks on the large mammalia with the description 
 of a gigantic creature of a very peculiar character, 
 whose bones occur with those of the mastodon, 
 elephant, and other animals which we have already 
 
 * The auroch is a species of wild bull or buffalo, distinct 
 from the common ox. The horns of the fossil ox are some- 
 times of enormous size : Mr. Parkinson had a pair in which 
 the length of each horn was 2 feet 7 inches. 
 
 f Dinos, terrible ; therion, a wild beast. 
 
{ j-7 THE DINOTHERIUM. 163 
 
 examined, as well as with the remains found in 
 more ancient deposits. In various parts of the 
 south of France large molar teeth, resembling in 
 their form and structure the teeth of tapirs, have 
 occasionally been found ; they are described by 
 Cuvier under the name of the " Gigantic Tapir." 
 Models of the principal specimens deposited in the 
 Museum at Paris, have been presented to me by 
 Baron Cuvier, together with others which I shall 
 place before you on a future occasion. Subsequent 
 discoveries in Bavaria, Austria, and particularly at 
 Eppelsheirn, about twelve leagues south of Mayence, 
 have made us acquainted with the form and struc- 
 ture of the original, which appears to have been 
 one of the largest of lacustrine animals, the skeletons 
 showing that some individuals were eighteen feet in 
 length I The scapula, or shoulder-blade, was like 
 that of the mole, and the fore leg must therefore 
 have been adapted for digging up the earth. The 
 most extraordinary deviation from ordinary types 
 consists, however, in the curved tusks, which are 
 fixed in the lower jaw in a downward direction, as 
 those of the walrus are in the upper ; the lower 
 jaw is four feet in length. From the structure of 
 the anterior portion of the cranium, and the dis- 
 position of the nasal fossae, it is certain that the 
 creature had a proboscis ; besides, it possesses no 
 incisor teeth with which to seize its food, and the 
 jaws do not even close together in front. The 
 tusks were probably weapons of defence, like 
 M2 
 
164 THE WONDERS OF GEOLOGY. LECT. II. 
 
 those of the 'elephant. This drawing, (Tab. 27,) 
 from a restoration by M. Kaup, an eminent German 
 naturalist, represents the supposed form of the ori- 
 ginal creature. It would appear that the dino- 
 therium was nearly related to the hippopotamus, 
 forming a link between the cetacea and pachyder- 
 mata, or large terrestrial mammalia ; and that it 
 was an herbivorous aquatic animal, inhabiting lakes 
 and marshes. 
 
 28. FOSSIL CARNIVORA IN CAVERNS. We 
 
 have passed in review the extinct population of a 
 remote period of our globe, those enormous pachy- 
 dermata, the mastodons and mammoths, that lie 
 buried in the alluvial and superficial strata. We 
 now arrive at the consideration of phenomena not 
 less interesting the occurrence of immense num- 
 bers of skeletons of carnivorous animals in fissures 
 and caverns. In the former discourse I alluded to 
 the cavities which abound in certain rocks of lime- 
 stone, and described the process by which their 
 roofs, floors, and walls were coated with sparry 
 incrustations, and ornamented with stalactites and 
 stalagmites (p. 62). Some of these caverns appear 
 to have been occasioned by the destruction of the 
 softer portions of the rock by subterranean streams ; 
 others are so extensive, and present such decided 
 marks of angular fracture, as to leave no doubt that 
 they have been produced by the shocks of earth- 
 quakes. The occasional occurrence of the bones 
 of animals in such cavities might reasonably be 
 
29. 
 
 FOSSIL CARNIVORA IN CAVERNS. 
 
 165 
 
 expected. Those that admitted of easy access from 
 without, might be frequented by species whose 
 habits lead them to retire into dark and secret 
 recesses ; while others, as kids, deer, &c. might fall 
 into open fissures, and their bones thus become 
 enveloped and preserved in calcareous incrusta- 
 tions. But the immense quantities of only one 
 or two species of carnivora that are found in some 
 caverns, show that these have been for a long period 
 the dens of extinct species of bears, wolves, tigers, 
 hyenas, and other carnivorous tribes. - 
 
 
 TAB. 28. VEKTICAL SECTION OP THE CAVE OP GAYLENREUTH. 
 
 29. CAVE OF GAYLENREUTH. For many cen- 
 turies, certain caverns in Germany have been cele- 
 brated for their osseous treasures, particularly those 
 
166 THE WONDERS OF GEOLOGY. LECT. II. 
 
 in Franconia : the most remarkable is that of 
 Gaylenreuth, which lies to the north-west of the 
 village, on the left bank of the river Wiesent. The 
 entrance, which is about seven feet high, is in the 
 face of a perpendicular rock, and leads to a series 
 of chambers from fifteen to twenty feet high, and 
 several hundred feet in extent, terminated by a 
 deep chasm, which, however, has not escaped the 
 ravages of visitors. This cavern is perfectly dark, 
 and the icicles, or pillars of stalactite, reflected by 
 the torches which it is necessary to use, present a 
 highly picturesque and striking effect. The floor 
 is literally paved with bones and fossil teeth; and 
 the pillars and corbels of stalactite also contain 
 osseous remains. Loose animal earth abounding in 
 bones, forms in some parts a layer ten feet in thick- 
 ness. A graphic description of this cave was 
 published by M. Esper, more than sixty years ago ; 
 at that period, some of the innermost recesses 
 contained waggon loads of bones and teeth ; some 
 imbedded in the rock, and others in the loose earth. 
 The bones in general are scattered and broken, but 
 not rolled ; they are lighter and less solid than 
 recent bones, and are often incrusted with stalac- 
 tite. Through the kindness of Lord Cole, and Sir 
 Philip de M. Grey Egerton, I am able to illustrate 
 these remarks by an extensive suite of osseous 
 remains, exhumed from the deepest recess in the 
 cavern, and collected a short time since by these 
 distinguished geologists. But the most interesting 
 
29. CAVE OF GAYLENREUTH. 107 
 
 specimen in my possession is a remarkably perfect 
 skull of a bear, which belonged to my late friend 
 Mr. Parkinson, the author of that delightful work, 
 " The Organic Remains of a Former World." A 
 comparison of this relic with the skull of the polar 
 bear, shows that it must have belonged to a species 
 of ursus.* Cuvier, who enjoyed the opportunity 
 of examining a very large collection of bones 
 from Gaylenreuth, was enabled to determine that 
 at least three-fourths of the osseous contents of the 
 caverns belonged to some species of bear ; and the 
 remaining portion to hyenas, tigers, wolves, foxes, 
 gluttons, weasels, and other small carnivora. By 
 the bones which were referable to the bear, he 
 established three extinct species of that genus ; 
 the largest of these has-a more prominent forehead 
 than any living species, and is called the Ursus 
 spelceus, or bear of the caverns, and it is to this 
 species the skull I have just mentioned belongs ; the 
 other has a flatter forehead, and has been named 
 Ursus arctoidaus. The hyena was allied to the 
 spotted hyena of the Cape, but differed in the 
 form of its teeth and head. Bones of the elephant 
 and rhinoceros are also said to have been dis- 
 covered, together with those of existing animals, 
 
 * Their Royal Highnesses the Princes George of Cumberland 
 and Cambridge, when inspecting my collection a few years 
 since, at Lewes, pointed out this skull to me as resembling 
 some fossils that had been exhumed from a fissure in limestone, 
 in the kingdom of Hanover. 
 
168 THE WONDERS OF GEOLOGY. LECT. II. 
 
 and fragments of sepulchral urns of high anti- 
 quity. 
 
 30. FORSTER'S HOHLE. Another cavern in this 
 part of Germany is mentioned by Dr. Buckland, as 
 one of the most remarkable for the beauty of its 
 incrustations. It is called Forster's Hohle, and varies 
 in height from ten to thirty feet ; its greatest width 
 is about ten yards. In the side vaults or recesses, 
 which descend, at an angle of about forty-five 
 degrees, into the main chamber, the stalagmite has 
 formed the appearance of cascades of pure alabaster, 
 the waves of which seem to be rushing out at the 
 bottom, to pour themselves into the stagnant lake 
 of the same substance which covers the floor. The 
 rocky roof has been corroded into deep cavities, 
 which are separated by partitions of every con- 
 ceivable form and tenuity, giving it the appearance 
 of the richly fretted gothic roof of a chapel, with 
 pendent corbels. Beautiful stalactites depending 
 from these projections, reach almost to the floor, 
 and contribute by their delicacy and transparency 
 to throw additional richness over the scene. 
 
 It is certainly, as M. Cuvier remarks, a most 
 extraordinary fact, that caves, spread over an extent 
 of two hundred leagues, should have the same 
 osseous contents. The relative proportions of the 
 different species are computed to be as follow : 
 three-fourths belong to bears two-thirds of the 
 remainder to hyenas and a small number to the 
 tiger or lion, and to the wolf or dog ; rolled pebbles 
 
31. BONE CAVERNS IN ENGLAND. 169 
 
 of a greyish blue marble are the only extraneous 
 materials found with the bones. Let me here call 
 your attention to the singular association of species 
 which some of these caves present; their recent 
 types being widely separated. Thus in one cavern, 
 animals allied to the spotted hyena of the Cape of 
 Good Hope, are collocated with the remains of 
 others related to the glutton, which inhabits Lap- 
 land; and in another, bones of the rhinoceros are 
 associated with those of the reindeer. Numerous 
 caves containing osseous remains are scattered over 
 the continents of Europe and America ; and even 
 in Australia, fossil bones belonging to animals of 
 different genera, but in a similar state of preserva- 
 tion, are found in caverns. 
 
 31. BONE CAVERNS IN ENGLAND KIRKDALE 
 CAVE. In England caverns containing bones of 
 bears, and other carnivora, in every respect analo- 
 gous to those of Germany which we have just 
 described, have been discovered and explored. 
 Dr, Buckland, in his valuable work, the Reliquice 
 Diluviance, has noticed several of the most impor- 
 tant assemblages of this kind. The cave of Kirk- 
 dale, now so well known in consequence of the 
 highly interesting disquisition on its contents by my 
 distinguished friend, is one of the most celebrated. 
 In the summer of 1821, a cave was discovered near 
 Kirkdale, about twenty-five miles NN.E. of York, 
 in a bank about sixty feet above the level of a small 
 valley, and near a public road. Some workmen 
 
170 THE WONDERS OF GEOLOGY. LECT. II. 
 
 who were quarrying stone, cut across the narrow 
 mouth of a chasm, which had been choked up with 
 rubbish, and overgrown with grass and bushes; 
 and which from this cause, as well as from its 
 inaccessible situation, had hitherto escaped obser- 
 vation, the entrance being so small that it was only 
 possible for a person to enter in a bent position. 
 
 P 
 
 4 feet. 
 TAB. 29. SECTION OP THE ENTRANCE OP THE CAVE OP KIRKDALE.* 
 
 A. Mud covering the floor of the cave to the depth of one foot, and con- 
 
 cealing the bones. 
 
 B. Stalagmite incrusting some of the bones, and formed before the mud 
 
 was introduced. 
 
 C. C. Stalagmite formed over the mud. 
 
 D. Insulated stalagmite on the surface of the mud. 
 
 E. E. Stalactites dependent from the roof. 
 
 The passage is exceedingly irregular in its dimen- 
 sions, varying from two to seven feet in breadth, 
 and from two to fourteen feet in height; its greatest 
 length is 245 feet. It divides into several smaller 
 
 * From Dr. Buckland's Reliq. Diluv. 
 
31. KIRKDALE CAVE. 171 
 
 passages, which have not yet been explored, as 
 they are nearly closed by stalactital concretions ; 
 these cavities occur where the roof is intersected 
 by fissures, which are continued for a few feet, but 
 are gradually lost in the superincumbent limestone, 
 and are thickly lined with stalactites. The true 
 floor was only seen near the entrance, for in the 
 interior the whole was covered with a bed of har- 
 dened mud or clay, about a foot in average thickness. 
 The surface was perfectly smooth and level when 
 the cave was first opened, except where stalagmites 
 had formed upon it by infiltration from the roof. 
 Where stalactitic matter incrusted the sides, it also 
 extended over the bottom like a thin coat of ice ; 
 and therefore must have been formed since the mud 
 was introduced. This mud or clay was filled with 
 fragments of bones belonging to a great variety of 
 animals ; and some of the bones exhibited marks of 
 having been gnawed. From many corroborative 
 circumstances these appearances are, with much 
 probability, supposed to have been occasioned by 
 hyenas. The bones thus preyed upon belong to 
 the tiger, bear, wolf, fox, weasel, elephant, rhino- 
 ceros, hippopotamus, horse, ox, and deer. Bones 
 of a species of hare or rabbit, water-rat, and mouse, 
 with fragments of the skeletons of ravens, pigeons, 
 larks, and ducks, were also imbedded with these 
 remains. 
 
 From these facts it is inferred that the cave 
 was inhabited by hyenas for a considerable period, 
 
172 THE WONDERS OF GEOLOGY. LECT. II. 
 
 that many of the remains found there were of 
 species which had been carried in, and devoured 
 by those animals, and that in some instances the 
 
 TAB. 30. THE LEFT SIDE op THE LOWER JAW op A HYENA, FROM 
 
 KlRKDALE CAVE. 
 
 hyenas preyed upon each other. Portions of ele- 
 phants' bones seem to show that occasionally the 
 large mammalia also served as food ; but it is 
 probable that many of the smaller animals were 
 drifted in by currents, or fell into the chasm, 
 through fissures now closed up by stalactitical in- 
 crustations. 
 
 KENT'S CAVE, near Torquay, which is nearly 
 600 feet in length, has yielded immense quantities 
 of bones of carnivora ; and in the Isle of Portland, 
 at Plymouth, and in the Mendip Hills, similar 
 accumulations have been found. In the south-east 
 of England but one instance is known ; a fissure in 
 the sand-rock at Boughton Quarries, near Maid- 
 stone, contained the jaw and bones of a hyena, 
 
32. DISEASED BONES OF CARNIVORA IN CAVES. 173 
 
 which are now in the museum at Oxford. This 
 fact proves the existence of the same condition of 
 animated nature in this part of our island, as in the 
 districts previously mentioned. Very recently a 
 cave has been discovered near Plymouth, in which 
 bones of hyenas were found in abundance, associated 
 with those of the elephant, rhinoceros, horse, &c. 
 
 From what has been stated, we learn that our 
 wastes and forests were once inhabited by extinct 
 carnivora, belonging to genera whose recent species 
 are almost entirely restricted to southern climates ; 
 that these lived and died for successive gene- 
 rations, and were the prey or the destroyers of each 
 other; that the hyenas, according to their peculiar 
 habits, dragged into their dens the creatures which 
 they killed or found dead, and devoured them at 
 their leisure ; that subsequently the races were 
 annihilated, and were succeeded by animals of a 
 character altogether different. 
 
 32. DISEASED BONES OF CARNIVORA FOUND IN 
 CAVES. Among the bones found in the caves of 
 Germany are many in a condition which must have 
 resulted from accident or disease. In some there 
 has been a formation of new bony matter to repair 
 fractures; in others there is anchylosis, or adhesion 
 of the joints from inflammation : while in some the 
 effects of caries, or decay of the bones, the result of 
 tedious and painful diseases, are apparent. Others 
 have a light and spongy character, and are very 
 fragile, which must have arisen from a want of 
 
174 THE WONDERS OF GEOLOGY. LECT. II, 
 
 energy in the nutritive system, in consequence of 
 a scrofulous affection.* 
 
 33. HUMAN BONES, AND WORKS OF ART, ix 
 CAVERNS. ^Bones of man, and fragments of ancient 
 pottery, have been found in caves, both in France 
 and Germany ; a circumstance perfectly natural, 
 since we are well aware that mankind, in a rude 
 state, have been in the habit of living in caves, and 
 traces of their having inhabited recesses, which 
 had previously been the retreat of wild animals, 
 were therefore to be expected. But as bones of 
 extinct animals occurred with them, it was rashly 
 assumed that they were coeval with each other ; 
 more accurate observations have, however, shown 
 that the human remains were introduced at a sub- 
 sequent period. We have historical proof that the 
 early inhabitants of Europe often resided, or sought 
 shelter in caves. Thus Florus records, that Caesar 
 ordered the inhabitants of Aquitania to be inclosed 
 in the caverns to which they had retired. Many 
 tribes of the Celtic race occupied these subterranean 
 retreats, not only as a refuge in time of war, but 
 also for shelter from cold ; as magazines for their 
 corn, and for the produce of the chase ; and as 
 places of concealment for the animals which they 
 had domesticated. The bones of such of these 
 people as perished, or were buried in these caverns, 
 
 * Professor Walther, on the antiquity of diseases of bones ; 
 see Professor Jameson's Cuvier's Theory of the Earth. Edin. 
 1827. 
 
34. OSSEOUS BRECCIA, OR BONE CONGLOMERATE. 175 
 
 would become blended with the mud, gravel, arid 
 debris of the animals already entombed ; and a 
 stalagmitical paste would in some places be formed 
 by the infiltration of water, as at Bize, and would 
 thus cement the whole into solid aggregates. We 
 should therefore expect to find masses of stone, 
 containing bones of the bear, and other extinct 
 species, associated with human bones, fragments of 
 pottery, terrestrial shells, and bones of animals of 
 modern times. Such are the contents of numerous 
 caves, and the above explanation points out the 
 mode in which such accumulations have taken 
 place.* 
 
 34. OSSEOUS BRECCIA, OR BONE CONGLOME- 
 RATE. The facts we have next to examine are 
 even more extraordinary than those which have 
 already been described ; for the osseous remains 
 which now claim our attention are not imbedded 
 in gravel or clay, or collected together in caves, but 
 are found in fissures of limestone, extending over 
 an area of many hundred leagues, and occurring in 
 rocks and islands, very remote from each other. 
 The limestone presents but little variety, the sub- 
 stance in which the bones are enveloped is every- 
 where the same, and the fossil remains belong, 
 with but few local exceptions, to similar species of 
 animals. The rocks are split in every direction, 
 and the fissures filled with what geologists term 
 an osseous or bone-breccia ; that is, bones, and 
 * Memoir by M. Desnoyer. 
 
176 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. II. 
 
 fragments of bones, held together by a calcareous 
 cement or paste, in the same manner as the con- 
 glomerated shingle of Kemp-Town ; or, to exem- 
 plify its nature by a still more familiar illustration, 
 the mixture of mortar, pebbles, &c. employed in 
 masonry, and called concrete. This cement is of 
 a reddish brown, very much resembling common 
 brick ; and the bones are beautifully white, having 
 in many instances their cavities lined with spar, 
 as in these specimens from Gibraltar. In some 
 examples the bones have undergone but little 
 change ; in others, the cells of the cancellated 
 structure, are filled with calcareous matter, as you 
 may observe in this specimen from Cerigo, (pre- 
 sented to me by Lady Mantell,) which is cut and 
 polished, to show the internal structure of the bones. 
 
 TAB. 31. TOOTH OF A RUMINANT IN OSSEOUS BRECCIA, FROM 
 GIBRALTAR, 
 
 This tooth of a species of ruminant (Tab. 31) frc 
 
35. THE ROCK OF GIBRALTAR. 177 
 
 Gibraltar, resembles in its general appearance the 
 teeth found in the Coombe-rock of the Brighton 
 cliffs. But the stone to which it is attached is 
 more compact, and partakes of the character of 
 marble ; it is of a dull red colour, mottled with 
 white, and is susceptible of a good polish. This 
 osseous breccia occurs on the northern shores of 
 the Mediterranean ; in the rock of Gibraltar ; at 
 Cette, Nice, and Antibes ; in Dalmatia, and in the 
 isles of Cerigo, Corsica, &c. ; and in Sicily, Sardi- 
 nia, and many parts of Germany. Each of these 
 localities present highly interesting examples of the 
 subject of our present inquiry. 
 
 35. THE ROCK OF GIBRALTAR. The rock of 
 Gibraltar, so well known from its historical and 
 political importance, affords an admirable illustra- 
 tion of the phenomena under review ; and, for the 
 sake of brevity, I shall chiefly confine my observa- 
 tions to that celebrated spot. Gibraltar is situated 
 on the Spanish side of the Mediterranean, being 
 united to the main land by a narrow isthmus, which 
 is about three-fourths of a mile broad, eight or ten 
 feet above the level of the sea, and formed of con- 
 solidated sand. The rock stands on the western 
 extremity of the area in which the osseous breccia 
 occurs, and its greatest altitude is about 1,350 feet. 
 It is in great part composed of a compact, bluish- 
 grey marble, which, like most extensive limestone 
 masses, is cavernous. The principal cavern, called 
 St. Michael's, contains stalagmites and stalactites, 
 
178 THE WONDERS OF GEOLOGY. LECT. II. 
 
 which when polished are of great beauty. In the 
 fissures intersecting the rock, as well as in some of 
 the caves, a calcareous concretion, of a reddish- 
 brown colour, occurs, which in some parts is a mere 
 earthy mass, but in others is highly indurated. The 
 bones are commonly in a broken state, and but 
 seldom water- worn ; and the fragments of limestone, 
 with which the fissures abound, are also angular, 
 and have evidently, like the bones, fallen into the 
 crevices at different periods, and been gradually 
 incrusted and conglomerated by calcareous infil- 
 trations. Snails and other land shells often occur 
 impacted in the solid breccia ; they belong to the 
 existing species of the country. As the concretion 
 is still in progress of formation, masses may be found 
 with terrestrial shells unmixed with bones. The 
 cementing material is very similar in the different 
 localities where the breccia has been observed ; 
 namely, at Cette, Nice, Antibes ; in Dalmatia and 
 Sardinia. The animal remains of the breccia are 
 referable to several species, some of which are 
 recent and others extinct, of deer, antelope, rabbit, 
 rat, mouse, &c. Bones of birds and of lizards have 
 been discovered at Cette ; and of lemmings,* and 
 of the lagomys,"\ which now only exists in Siberia : 
 it is but rarely that traces of carnivora are observed. 
 No one can fail to be struck with surprise at the 
 
 * Lemming, or Lapland marmot. 
 
 f Signifying rat-hare. A genus of animals which forms a 
 link between the hare and the rat. 
 
3. OSSEOUS BRECCIA OF AUSTRALIA. 179 
 
 occurrence of these isolated, yet analogous pheno- 
 mena, which surround the great basin of the Medi- 
 terranean rocks of a uniform character, fissured and 
 broken, their rents filled up with similar materials, 
 and with the remains of the same species of animals. 
 The occurrence of species, either extinct, or no 
 longer inhabiting the same latitudes (as the lago- 
 mys), refers the period of the existence of these 
 animals to the epoch of the mammoths and masto- 
 dons ; and the absence of marine remains, and of 
 the usual abrading effects of water, show that the 
 breccia was formed on dry land, and not beneath 
 the sea. 
 
 The rational explanation of these facts appears 
 to be that which assumes the original union of these 
 -distant rocks and islands into a continent, or large 
 island, which, like Calabria, was subject to repeated 
 visitations of earthquakes ; and that the animals 
 which inhabited the country fell into the fissures 
 thus produced, and were preserved by the calca- 
 reous infiltrations that were constantly in progress. 
 Subsequent convulsions severed the country into 
 rocks and insular masses, of which catastrophe the 
 osseous conglomerates are the physical and only 
 record. 
 
 36. OSSEOUS BRECCIA OF AUSTRALIA. Caves 
 and fissures, filled with osseous breccia, in the same 
 manner with those I have described, have also been 
 discovered in New Holland, to the westward of 
 Sydney, near the banks of the Macquarrie river ; 
 N 2 
 
180 THE WONDERS OF GEOLOGY. LECT. II. 
 
 and it is not a little remarkable, that even the red 
 ochreous colour of the European conglomerates 
 prevails ; the bones, however, belong to animals 
 wholly distinct from any hitherto noticed in the 
 preceding examples. Some of them are of living, 
 others of extinct species, but all of them are refer- 
 able to marsupial animals, as the kangaroo^ wombat, 
 dasyuruS) &c. A portion of a large bone, found 
 in a cave, is said to resemble the leg-bone of the 
 hippopotamus, but this requires confirmation ; it is, 
 however, a subject worthy of attention, since the 
 kangaroo is the largest animal now known in those 
 regions. The fact that all the fossil animals of 
 Australia hitherto discovered, are marsupial, that 
 is, belong to the mammalia which carry their young 
 in a pouch a type of organization which is the 
 peculiar feature of the existing races of the coun- 
 try is also of great interest ; for it proves that the 
 present zoological character of those regions has 
 prevailed from a very remote period. 
 
 37. RETROSPECT. I must now bring to a close 
 this examination of the ancient superficial deposits 
 those accumulations of alluvial matter, which 
 taken as a whole, are referable to a far more 
 early period than those which strictly belong to the 
 modern or human epoch. And as in the former 
 discourse I found it necessary to dwell on the dis- 
 coveries of astronomy, to elucidate some of the 
 physical changes of our planet ; in the present I 
 have summoned comparative anatomy to our aid, 
 
37. RETROSPECT. 181 
 
 and have endeavoured to point out the mode of 
 induction pursued by the palaeontologist, in his 
 inquiries into the fossil remains of animal organiz- 
 ation, by which he is enabled to call forth from 
 their rocky sepulchres, the beings of past ages, and 
 like the fabled sorcerer, give form and animation to 
 the inhabitants of the tomb. 
 
 From the facts that have been presented to us in 
 the course of this lecture, we arrive at the following 
 important inferences : 
 
 First that the extinction of certain forms of 
 animal existence is a law, which is not only in ope- 
 ration at the present moment, but has extended 
 throughout the period comprehended in our present 
 researches ; and we have traced its influence from 
 the partial extirpation of certain existing species, to 
 the entire annihilation of many species and genera 
 that once were contemporary with man ; as well as 
 to those which are known to have lived, and become 
 extinct, prior to the creation of our race. 
 
 Secondly that while in the modern marine and 
 fluviatile accumulations, the remains of existing 
 species of animals, and of man and his works, are 
 entombed, in the ancient deposits of water-worn 
 materials, those of larger mammalia alone are im- 
 bedded. 
 
 Thirdly that the animal remains principally 
 belong to extinct pachydermata, related to the 
 elephant, hippopotamus, sloth, horse, deer, and 
 other ruminants ; and that these had for their 
 
182 THE WONDERS OF GEOLOGY. LECT. II. 
 
 contemporaries, bears, hyenas, tigers, and other 
 carnivora of species now extinct. 
 
 Fourthly that there was therefore a period im- 
 mediately preceding the existence of man, when 
 the earth teemed with large herbivorous animals, 
 which roamed through the primeval forests unmo- 
 lested, save by beasts of prey. Numerous species 
 and entire genera have been swept away from the 
 face of the earth, some by sudden revolutions, 
 others by a gradual extinction, while many have 
 been exterminated by man. 
 
 Lastly that these various strata, whether formed 
 in the beds of lakes or rivers, in estuaries, or in the 
 depths of the ocean, have been elevated above the 
 level of the sea, and now constitute fertile coun- 
 tries, supporting the busy population of the human 
 race. 
 
 I have thus endeavoured to interpret one page of 
 the ancient physical history of our planet, and to 
 explain the records of one epoch in geological 
 chronology. We have entered upon the confines of 
 the past, and already we find ourselves surrounded 
 by an innumerable population of unknown types of 
 being, not as dim and shadowy phantoms of the 
 imagination, but in all the reality of form and 
 structure, and bearing the impress of the mighty 
 changes of which they constitute the imperishable 
 memorials. We have again witnessed the effects of 
 the continual mutations of the land and water, 
 
37. RETROSPECT. 183 
 
 have seen that our present plains and valleys were 
 submerged beneath the ocean, at a period when 
 large mammalia, apparently unrestricted by existing 
 limits of climate, were inhabitants of regions which 
 are now no more and we have obtained additional 
 proof that 
 
 New worlds are still emerging from the deep, 
 The old descending in their turn to rise ! 
 
 Even in this early stage of our progress, we have 
 conclusive evidence of the extinction of whole tribes 
 of animals, equally admirable in their adaptation to 
 the conditions in which they were placed, as the 
 races which now exist. And delightful it is to 
 the geologist, to find that this fact, which but a few 
 years since was received with hesitation by most, 
 and condemned and rejected by many, is now ad- 
 duced by the moralist and the divine, as affording 
 new proofs of the wisdom and overruling providence 
 of the Eternal. Reflecting on these phenomena, 
 the mind recalls the impressive exclamation of the 
 poet 
 
 My heart is awed within me, when I think 
 Of the great miracle which still goes on 
 In silence round me the perpetual work 
 Of THY creation, finished, yet renewed 
 For ever ! 
 
LECTURE III. 
 
 1. Introductory remarks. 2. Substances composing the crust of the 
 globe. 3. Crystallisation. 4. Stratification. 5. Inclined and vertical 
 strata. 6. Veins and faults. 7. Chronological arrangement of the 
 strata. 8. Tertiary formations. 9. Classification of the tertiary strata. 
 10. Fossil shells. 11. Mineralogical characters of the tertiary system. 
 12. Newer tertiary or pliocene deposits. 13. Crag of Norfolk and 
 Suffolk. 14. The Sub-Apennines. 15. Middle tertiary, or miocene 
 deposits. 16. Lower tertiary, or eocene deposits. 17. The Paris basin. 
 18. The London basin. 19. The Isle of Sheppey. 20. Fossil fruits of 
 the tertiary strata. 21. Upper marine, or Bagshot sand. 22. Artesian 
 wells. 23. The Hampshire or Isle of Wight basin. 24. Alum bay. 
 25 London clay of the Hampshire basin. 26. Fresh-water strata of the 
 Isle of Wight. 27. Organic remains of the Paris, London, and Hants 
 basins. 28. Fossil plants and zoophytes. 29. Tertiary marine and 
 fresh-water shells. 30. Nummulites, and other cephalopoda. 31. Crus- 
 tacea and fishes. 32. Fossil birds. 33. Fossil animals of Paris. 34. 
 Palaeotheria and anoplotheria. 35. Fossil quadrumana, or monkeys. 
 36. Tertiary strata of Aix, in Provence. 37. Fossil insects. 38. Lacus- 
 trine formation of GEningen. 39. Fossil fishes of Monte Bolca. 40. 
 Tertiary volcanoes of France. 41. Extinct volcanoes of Auvergne. 
 42. The crater of Puy de Come. 43. Mont Dor. 44. Fresh-water lime- 
 stone and organic remains of Auvergne. 45. Summary of the geological 
 phenomena of Auvergne. 46. Erosion of valleys by water-currents. 
 47. Extinct volcanoes of the Rhine. 48. Brown coal formation. 49. 
 Other tertiary strata of Europe, North America, &c. 50. Altered ter- 
 tiary strata of the Andes. 51. Tertiary saliferous deposit. 52. Retro- 
 spect. 53. Concluding remarks. 
 
 1. INTRODUCTORY REMARKS. It is my object 
 in these Lectures to present a general view of the 
 philosophy of Geology, rather than enter at length 
 on the nature and distribution of the materials of 
 which the crust of our globe is composed ; and to 
 render the details of geological phenomena subser- 
 
J 1. INTRODUCTORY REMARKS. 185 
 
 vient to an explanation of the laws which the 
 Divine Author of all things has established for the 
 renovation, maintenance, and government of the 
 organic and inorganic kingdoms of Nature. Based 
 as Geology is upon observations of the various 
 physical changes which are now taking place, and 
 on investigations of the natural records of those 
 changes, in periods antecdent to all human history 
 and tradition, the rocks and mountains are the 
 alphabet, the book of Nature the volume, by which 
 the student of this interesting department of science 
 can best learn its important lessons. But to those 
 who cannot examine Nature in her secret recesses, 
 or accompany an experienced teacher to the valleys, 
 or the mountain-tops, lectures illustrated by speci- 
 mens and drawings, afford, perhaps, the best sub- 
 stitute for the more efficient and delightful mode of 
 instruction. 
 
 That we may obtain a clear and comprehensive 
 view of the vast field of inquiry that lies open before 
 us, artificial classifications are necessary in this, as in 
 other departments of science ; and without assuming 
 that the arrangement in which the various deposits 
 are grouped by geologists, will not, in the progress 
 of discovery, require considerable modification, it 
 will be necessary, as an introduction to the subjects 
 hereafter to be discussed, to place before you a 
 tabular view of the formations in their presumed 
 chronological order. At the same time it is necessary 
 to bear in mind, that all classifications of this kind 
 
186 THE WONDERS OF GEOLOGY. LECT. III. 
 
 must necessarily involve arbitrary distinctions, and 
 that very possibly it will hereafter be found that 
 we may in some instances have classed as general, 
 what may prove to be merely local phenomena ; and 
 have grouped together deposits, which farther in- 
 vestigations may show to be distinct, and separated 
 from each other by vast periods of time. This con- 
 sideration will not, however, affect those leading 
 principles of modern Geology, which it is my pre- 
 sent endeavour to render familiar to the intelligent 
 but unscientific inquirer. 
 
 We will now take a general view of the nature of 
 the mineral substances which enter into the compo- 
 sition of the crust of our globe, and briefly notice 
 the laws which regulate the deposition of detritus in 
 the beds of lakes and rivers, and in the depths of the 
 ocean. But, as I have already remarked, it is not my 
 intention to enter on these departments of Geology 
 in detail ; the works of Bakewell,* Lyell,f Phillips, J 
 
 * " Introduction to Geology," by Robert Bakewell, Esq. 
 1 vol. 8vo. 5th edition. This excellent volume should be the 
 first book in the library of the geological student. 
 
 f " The Principles of Geology," by Charles Lyell, Esq. 
 F.R.S. 4 vols. 12mo. One of the most interesting works in 
 the English language. " Elements of Geology." 1 vol. By 
 the same author. 1838. 
 
 J " A Guide to Geology," by John Phillips, Esq. RR.S. 
 1 vol. 12mo. The article on Geology, in the Encyclopedia 
 Metropolitana, by the same excellent writer, is in my opinion 
 the best scientific epitome of modern Geology that has yet 
 appeared. " A Treatise on Geology," in 2 vols. foolscap 8vo. 
 by the same author. 1839. A work of great merit. 
 
2. CRUST OF THE GLOBE. 187 
 
 De la Beche,* Burr,-)- and others, afford all the 
 information on these subjects which the student can 
 require. 
 
 2. SUBSTANCES COMPOSING THE CRUST OF THE 
 GLOBE. Every substance .is composed of atoms of 
 inconceivable minuteness, held together by a prin- 
 ciple termed attraction or cohesion, and which is 
 probably a modification of that influence, which, 
 as it exists under other conditions in inorganic 
 substances, is called electricity, galvanism, or mag- 
 netism ; and in organized beings, nervous influence. 
 As the different stages of solidity, fluidity, or vapour, 
 in which every material body may exist, have been 
 exemplified in the former lectures, we need only 
 remark, that there are about sixteen substances, 
 which in the present state of chemical knowledge 
 are considered simple in themselves, and which, 
 in their various combinations, constitute by far 
 the largest amount of the gaseous, liquid, solid, 
 organic, and inorganic matter of the earth. Of 
 these, eight are non-metallic ; viz. oxygen, hydrogen, 
 nitrogen, carbon, sulphur, chlorine, fluorine, and 
 phosphorus. There are also six metallic bases 
 of alkalies and earths, namely, silicium, alumine, 
 
 * " A Geological Manual," by H. T. De la Beche, Esq. 
 F.R.S. An admirable work of reference. " Researches in 
 Theoretical Geology." A volume of considerable interest, 
 affording a condensed and perspicuous view of the theories of 
 modern geologists. 
 
 f " Elements of Practical Geology," by Frederick Burr, Esq. 
 1 vol. foolscap 8vo. 
 
188 THE WONDERS OF GEOLOGY. LECT. Ill- 
 
 potassium, sodium., magnesium, and calcium ; and 
 two, the oxides of which are neither earths nor 
 alkalies, namely, iron and manganese. The re- 
 maining metallic substances, copper, lead, zinc, 
 arsenic, silver, gold, &c. are comparatively unim- 
 portant in a geological point of view. 
 
 The common sedimentary rocks are in a great 
 measure composed either of lime, silex, or argilla- 
 ceous earth; and they possess, what in rninera- 
 logical language is called, a cleavage, or peculiar 
 fracture, which is distinct in each. Thus, if I take 
 a flint and break it at random, you perceive that it 
 presents a glassy or conchoidal fracture, a sharp 
 cutting edge; and subdivide it as I may, it still 
 retains the same character : but if I break a piece 
 of chalk, the edge is not sharp or cutting, but blunt 
 and dull, exhibiting what is called in mineralogy an 
 earthy fracture. Again, if I shiver to pieces with 
 my hammer this calcareous spar, every fragment 
 presents, more or less distinctly, a rhomboidal form ; 
 so true is the remark, that we cannot break a stone 
 but in one of nature's joinings. 
 
 3. CRYSTALLIZATION. Crystallization may be 
 defined a methodical arrangement of the particles 
 of matter according to fixed laws. For instance 
 there are nearly 500 varieties of crystallized car- 
 bonate of lime, each crystal being composed of 
 millions of atoms of the same compound substances, 
 and having one invariable primary form that of 
 a rhomboid. Mechanical division is incapable of 
 
4. STRATIFICATION. 189 
 
 altering this arrangement ; break them as we may, 
 we can only separate them into a rhomboidal figure ; 
 nor can this condition be altered except by chemical 
 decomposition. If we pursue our investigations 
 yet farther, analysis shows that every atom of these 
 crystals consists of quicklime and carbonic acid, 
 which are each made up of innumerable molecules. 
 " Lime and carbonic acid are also themselves com- 
 pounds, lime being composed of a metal called 
 calcium and oxygen ; and carbonic acid, of carbon 
 and oxygen. Thus these ultimate particles of cal- 
 cium, carbon, and oxygen, form the indivisible atoms 
 into which all the secondary crystals of lime may be 
 reduced."* 
 
 4. STRATIFICATION. As our previous investi- 
 gations have shown that the disintegration and 
 solution of the most refractory, and apparently in- 
 destructible substances, by the conjoined effects of 
 mechanical and chemical agency, are constantly in 
 progress, we can at once proceed to the consi- 
 deration of the manner in which the spoils of the 
 ancient lands and seas have been accumulated, and 
 converted into the rocks and strata of existing 
 islands and continents. I have already adverted 
 to the formation of beach and sand, and the depo- 
 sition of mud and clay in layers or strata, and their 
 subsequent consolidation into rocks. And here let 
 me remind you, that strata are the successive layerg 
 or accumulations of detritus, spread over each 
 * Dr. Bucklaud's Bridgwater Essay. 
 
190 THE WONDERS OF GEOLOGY. LECT. III. 
 
 other, in such manner as to allow of the partial 
 consolidation of one bed, before it is covered by a 
 deposition of the materials of another ; and a rock 
 is said to be stratified, when it presents the appear- 
 ance of such divisions. The chalk cliffs, and the 
 sandstone quarries in the south-east of England, 
 afford excellent illustrations of this structure. The 
 original direction of these layers must have been 
 more or less horizontal, for this obvious reason, 
 that in their fluid, or semi-fluid state, they would 
 find their own level, and spread over the surface of 
 the basin into which they flowed ; and although 
 they might partake of the inequalities of the depres- 
 sion in which they were deposited, yet this cause 
 would not affect their general distribution. The 
 strata when accumulated in very thin layers, re- 
 sembling the seams formed by the leaves of a closed 
 book, are termed lamince ; and this character very 
 commonly prevails in fluviatile or river deposits: 
 thus the shales, clays, and sandstones, of Tilgate 
 Forest are laminated, and often bear the impress 
 of the waters which have meandered over them 
 (see pages 4-2, 43). The contemporaneous beds 
 formed in the same oceanic basin, however they 
 may maintain a general character over very exten- 
 sive areas, must nevertheless vary considerably. At 
 the present moment, the rivers flowing from different 
 latitudes into our existing seas, must necessarily be 
 producing in the same marine basin accumulations 
 of a very dissimilar character ; and the geographical 
 
$ 5. INCLINED AND VERTICAL STRATA. 191 
 
 distribution of the detritus, must be still more 
 affected by the agency of those powerful currents, 
 to which allusion has already been made (page 55). 
 Bearing in mind these elements of variation in the 
 depositions that may contemporaneously take place 
 within the same oceanic basin, we shall be prepared 
 to find similar discrepancies in the contents of the 
 beds of the ancient seas. 
 
 5. INCLINED AND VERTICAL STRATA. But 
 although the strata, whether accumulated in banks 
 or ridges, or deposited in basins or depressions, 
 have originally been consolidated in horizontal 
 layers, yet this arrangement has frequently been 
 disturbed by expansive forces from below, and the 
 strata have been broken up, and thrown into every 
 direction, from a slight degree of inclination, to a 
 vertical position. The sections before us, (Plates 
 7, 8, 9, 10,) to which I shall hereafter have occasion 
 to refer, exhibit strata in various states of dis- 
 placement. 
 
 Although it is my wish to abstain as much as 
 posible from technical language, yet as it cannot in 
 all cases be avoided without much circumlocution, 
 it will be convenient in this place to explain a few 
 scientific terms which are commonly employed. 
 Thus, parallel layers or strata, piled, as it were, 
 horizontally upon each other, as or, i, c, c?, in the 
 following diagram (and in the Section near Devizes, 
 Plate 9, No. II.) are said to be conformable ; but 
 when strata are superimposed on others which lie 
 
192 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. III. 
 
 in a different direction, as the series a, b, c, d, on the 
 beds e,f,g,h, (or in the natural section, Plate 9, 
 No. III.) as if a set of horizontal volumes were 
 
 
 h h 
 
 TAB. 32. STRATIFICATION. 
 
 placed flat on the inclined edges of another series 
 of books, they are, in geological language, in an 
 unconformable position. 
 
 6. VEINS AND FAULTS. But not only have the 
 strata suffered change of position from the disturb- 
 ing causes which we have shown are still in actual 
 operation ; they have also been rent and broken up, 
 and exhibit cracks or fissures, which in rocks near 
 the surface are sometimes filled, as we have already 
 noticed, with bones, pebbles, and stalactitical con- 
 cretions (page 178) ; and in those of more ancient 
 epochs, with eruptions of melted matter, and veins of 
 metalliferous ores. The term fault is applied to those 
 fractures and displacements of the strata which are 
 
7. VEINS AND FAULTS. 193 
 
 accompanied with the subsidence of one part of a 
 mass and the elevation of another. This is exem- 
 plified in the section of the carboniferous strata, 
 (Tab. 32, e,f, g> h,) where the layers, or seams of 
 coal, have been shifted to a higher level, although 
 both sides of the rock remain in apposition ; f marks 
 the line of fault, Stratification, in fact, may be 
 compared with the operation of erecting a building ; 
 strata of clay being comparable to beds of mortar, 
 those of harder rocks to layers of brick ; while the 
 fissures, veins, and faults are analogous to the cracks, 
 sinkings, and displacements produced by the settling 
 of different portions of the whole edifice. 
 
 7. CHRONOLOGICAL ARRANGEMENT OF THE 
 STRATA. In the ancient alluvial beds of gravel, 
 sand, and marl, containing the remains of gigantic 
 mammalia, which formed the principal subject of 
 the last lecture, but few indications of stratification 
 occur ; those deposits, for the most part, bearing 
 the character of materials transported by the sea 
 or by river currents, or accumulated in estu- 
 aries, and thrown up in bays and creeks by the 
 waves, rather than that of tranquil depositions. 
 The formations which succeed, we shall find com- 
 posed of regularly stratified rocks, but interspersed 
 here and there with alluvial debris. The plan of 
 the strata before you (Plate 7) is intended to pre- 
 sent a general view of the various systems of rocks, 
 from the most recent to the most ancient. For 
 more detailed explanations and sections, reference 
 o 
 
194 THE WONDERS OF GEOLOGY. LECT. III. 
 
 may be made to the works already noticed ; and 
 particularly to the admirable systematic diagram 
 of the formations, by that veteran geologist, IVlr. 
 Webster, which forms the frontispiece of Dr. Buck- 
 land's Bridgewater Essay. 
 
 It will here be necessary to premise, that there 
 are three elements of classification applicable to 
 stratified rocks; namely, 1st, their mineral struc- 
 ture ; 2dly, their order of superposition ; and 3dly, 
 the nature of the organic remains which they con- 
 tain : the following arrangement is in accordance 
 with these principles.* 
 
 CHRONOLOGICAL ARRANGEMENT OF THE 
 STRATA. 
 
 Commencing with the uppermost or newest Deposits. 
 
 FOSSILIFEROUS STRATA. 
 
 I. MODERN AND ANCIENT ALLUVIUM. Comprising the modern 
 and ancient superficial deposits, described in the previous 
 lectures. The modern are characterised by the remains of 
 man and contemporaneous animals and plants ; the ancient, 
 by an immense proportion of large mammalia and carnivora, 
 of species and genera, both recent and extinct. 
 
 II. THE TERTIARY SYSTEM. An extensive series, comprising 
 groups of marine and lacustrine deposits, characterised by 
 the remains of animals and vegetables, the greater portion 
 of which are extinct. Volcanoes of great extent were in 
 activity during this epoch. 
 
 * See Professor Sedgwick's Synopsis of the English Series of Stratified 
 Rocks inferior to the old Red Sandstone. Proceedings of the Geological 
 Society, vol ii. p. 76. 
 
7. ARRANGEMENT OF THE STRATA. IQj 
 
 SECONDARY FORMATIONS. 
 
 III. THE CHALK, or CRETACEOUS SYSTEM. A marine forma- 
 tion, comprising beds of limestone, sandstone, marl, and 
 clays, abounding in remains of zoophytes, mollusca, cephalo- 
 poda, echinodermata, fishes, &c. ; drifted wood, and marine 
 plants ; with crocodiles, turtles, and extinct reptiles. 
 
 IV. THE WEALDEN. Comprising the weald clay, the strata of 
 Tilgate Forest, and of Hastings, and the limestones and 
 clays of Purbeck. A freshwater formation, evidently the 
 delta of some ancient river ; characterised by an abundance 
 of the remains of enormous and peculiar reptiles, namely, 
 the iguanodon, hylaeosaurus, megalosaurus, plesiosaurus, 
 crocodile, &c. ; of terrestrial plants, freshwater mollusca, 
 and birds. 
 
 V. THE OOLITE A marine formation of vast extent, consist- 
 ing of limestones and clays, abounding in marine shells, 
 corals, fishes, and reptiles, both terrestrial and marine. 
 Land plants of peculiar species, and the remains of two or 
 more genera of MAMMALIA. 
 
 VI. THE LIAS. A series of clays, shales, and limestones, with 
 marine shells, cephalopoda, crinoidea, and fishes. Reptiles, 
 particularly of two extinct genera, the plesiosaurus and 
 ichthyosaurus, in immense numbers. Drifted wood and 
 plants. 
 
 VII. THE SALIFEROUS, or NEW RED SANDSTONE SYSTEM. 
 Comprising marls, sandstones, and conglomerates, fre- 
 quently of a red colour, with shells, corals, and plants ; 
 fishes and reptiles. This series forms the grand depository 
 of rock- salt 
 
 VIII. THE CARBONIFEROUS, or COAL SYSTEM. Shales, iron- 
 stones, millstone grit, freshwater limestone, and immense 
 beds of coal. This system is characterised by innumerable 
 remains of land and aquatic plants, of a tropical character, 
 and belonging to extinct species and genera; with fishes, 
 reptiles, and insects. 
 
 o2 
 
196 THE WONDERS OF GEOLOGY. LECT. III. 
 
 IX. THE OLD RED SANDSTONE SYSTEM.* Consisting of various 
 strata of conglomerate, sandstone, marl, and limestone ; the 
 prevailing colour of a chocolate red ; contains shells, corals, 
 and fishes, many of which are peculiar. 
 
 X. THE SILURIAN SYSTEM. Composed of marine limestones, 
 shales, sandstones, and calcareous flags ; abounding in 
 shells, many of new forms ; and swarming with corals, 
 crinoidea, and trilobites. 
 
 XI. THE CAMBRIAN, or GRAUWACKE SYSTEM. Consists prin- 
 cipally of a largely developed series of slate rocks and con- 
 glomerates, containing shells and corals. 
 
 METAMORPHIC ROCKS. 
 Destitute of Organic Remains. 
 
 Stratified. 
 
 XII. THE MICA SCHIST. Sedimentary rocks, altered by high 
 temperature ; mica slate, quartz rock, crystalline limestone, 
 gneiss, and hornblende schist, &c., exhibiting no traces of 
 organic remains. 
 
 XIII. THE GNEISS SYSTEM. Formed of gneiss, sienite, and 
 quartz rock, alternating with clay slate, mica schist, &c. 
 
 Unstratified. 
 
 XIV. GRANITE. In amorphous masses and veins ; porphyry, 
 serpentine, trap, &c. 
 
 The proportionate thickness of the rocks hitherto 
 examined in England is estimated as follows ;( but 
 
 * Fide " Geology of the Silurian Region," 2 vols. 4to. with 
 numerous plates and map, by Roderick Impey Murchison, Esq. 
 V.P.G.S. The most splendid and important work on British 
 Geology that has yet appeared. 
 
 f Professor Phillips. 
 
8. TERTIARY FORMATIONS. 197 
 
 the statement must be viewed only as an approxi- 
 mative calculation. 
 
 Tertiary system .... 2,000 feet. 
 
 Cretaceous 1,100 
 
 Oolitic and lias 2,500 
 
 Saliferous 2,000 
 
 Carboniferous 10,000 
 
 Old red sandstone .... 9,000* 
 
 Primary rocks 20,000 
 
 I have represented in this diagram (Plate 7) in- 
 trusions of the ancient melted rocks, as serpentine, 
 porphyry, trap, and granite, into the sedimentary 
 strata ; and metalliferous and granitic veins in the 
 granite, to which I shall hereafter have occasion 
 to refer. At present it will only be necessary to 
 mention, that the leading features of this arrange- 
 ment may be recognised in every considerable extent 
 of country throughout the world ; but the sub- 
 divisions are more local, and cannot be generally 
 maintained, for reasons which must be sufficiently 
 obvious, after what has already been advanced. 
 From this general view of the physical records of 
 the mutations which the crust of our globe has 
 undergone, we learn how numerous and important 
 are the phenomena comprised within the sphere of 
 geological inquiry, and how vain is the attempt to 
 offer more than an epitome of its wonders in the 
 brief space allotted to a popular course of lectures. 
 
 8. TERTIARY FORMATIONS. We now enter 
 * Mr. Murchison. 
 
198 THE WONDERS OF GEOLOGY. LECT. III. 
 
 upon the consideration of the tertiary formations, 
 those deposits of the seas, rivers, and lakes, which 
 are referable to the period immediately antecedent 
 to the existence of the mammoth and mastodon, 
 and subsequent to the deposition and consolidation 
 of the chalk. The discoveries of MM. Cuvier and 
 Brongniart, about twenty years since, in the imme- 
 diate vicinity of Paris, first directed the attention 
 of geologists to the important series of strata which 
 is now distinguished by the name of tertiary (see 
 p. 18). The animals whose fossil bones abound in 
 the gypsum quarries of Montmartre, and belong to 
 extinct genera of mammalia, were by the genius of 
 Cuvier, again, as it were, called into existence, and 
 the philosophers of Europe saw with astonishment, 
 whole tribes of unknown and extraordinary types 
 of being, disinterred from rocks and mountains, 
 which had hitherto been considered as possessing 
 no scientific interest. Analogous strata, some of a 
 marine, and others of a lacustrine or fluviatile cha- 
 racter, have since been discovered in numerous 
 localities in the continents of Europe and America, 
 forming a series so extensive, and requiring such a 
 lapse of time for its production, that the chalk, 
 hitherto considered as comparatively modern, is 
 carried back to a period of immense geological an- 
 tiquity. The tertiary system may be said to con- 
 stitute a series of formations which link together 
 the present and the past ; for while the most ancient 
 contain organic remains related to those of the 
 
9. CLASSIFICATION OF THE TERTIARY STRATA. 199 
 
 secondary formations, the most recent insensibly 
 glide into the modern deposits, and contain remains 
 of many existing species of animals and plant?, 
 associated with forms that are now blotted out for 
 ever. Mr. Lyell has adopted a classification of the 
 tertiary strata, founded on the proportion of recent 
 species of animals which they contain ; and as shells 
 occur in many of the strata in great abundance, 
 and in an excellent state of preservation, those types 
 of animal organization have been selected for the 
 distinctive characters of the subdivisions into which, 
 for the convenience of study, he separates these 
 deposits. In the present state of our knowledge, 
 this arrangement is of great utility, but it appears 
 probable that it may require considerable modifica- 
 tion, or, perhaps, hereafter be altogether abandoned 
 with the progress of geological research ; for it 
 cannot be doubted, that strata in which no recent 
 species have yet been found, may yield them to 
 more accurate and extended observations. 
 
 9. CLASSIFICATION OF THE TERTIARY STRATA. 
 According to this classification the tertiary system 
 forms four principal groups, each of which is cha- 
 racterised by the relative proportion of recent and 
 extinct species of shells which it contains ; and a 
 nomenclature has been adopted to denote the cha- 
 racters upon which the arrangement is founded. 
 These divisions are as follow : 
 
 1. THE PLIOCENE (signifying more new or 
 recent). Tertiary strata, in which the shells are for 
 
200 THE WONDERS OF GEOLOGY. LJECT. III. 
 
 the most part recent, with about ten per cent, of 
 extinct species ; these beds are subdivided into the 
 newer and older pliocene. 
 
 2. THE MIOCENE (denoting less recent). Con- 
 taining a small proportion, about twenty per cent., 
 of recent species of shells. 
 
 3. EOCENE (signifying the dawn of recent, in 
 allusion to the first appearance of recent species). 
 Containing very few recent species, perhaps not 
 more than three or four per cent. 
 
 The marine are associated with a like number of 
 freshwater formations, and the general characters 
 of the tertiary system are alternations of marine 
 with lacustrine strata. The districts occupied by 
 these beds in Europe, are exceedingly variable in 
 extent, as Mr. Lyell has shown in a very ingenious 
 map of the tertiary seas ;* and it appears certain, 
 that during the epoch of their formation, there were 
 areas which were alternately the sites of freshwater 
 lakes and .inland seas, and that these changes were 
 dependent on oscillations in the relative level of the 
 land and water. 
 
 10. FOSSIL SHELLS. The geological evidence 
 afforded by the remains of animals and plants has 
 already been fully exemplified; but our remarks 
 have hitherto in a great measure been confined to 
 the fossilized skeletons of terrestrial quadrupeds ; 
 the shells of mollusca, however, from their dura- 
 bility, often escape obliteration under circumstances 
 * Mr. LyelPs Principles of Geology, vol. i. p. 214. 
 
10. FOSSIL SHELLS. 201 
 
 in which all traces of the higher orders of animals 
 are lost. In loose sandy strata, they occur in a high 
 degree of perfection ; in mud and clay, in a fragile 
 state ; in some instances they are silicified ; and 
 many limestones are wholly composed of their re- 
 mains, cemented together by calcareous matter. 
 Molluscous animals* are divided into mollusca, 
 properly so called, which are covered with a shell, 
 as snails, periwinkles, &c. ; and conc/[ifera,-\- having 
 a shell with two valves, as the oyster, scallop, &c. 
 The former are of a higher organization than the 
 latter, having eyes, and a distinct nervous system ; 
 the latter have neither eyes nor head, and are there- 
 fore called acephala.~^ Some genera of mollusca 
 are herbivorous, living exclusively on vegetables ; 
 others are carnivorous ; and many have a retractile 
 proboscis, furnished with a rasp, by which they can 
 perforate wood, shells, stone, and other substances. 
 The shells of the carnivorous testacea are also 
 generally provided with a channelled or grooved 
 beak for the reception of the fleshy syphon by which 
 the sea water is conveyed to the respiratory organs 
 (Tab. 38. Fig. 3, 4, 5); while the herbivorous have 
 the opening of the shell entire (Tab. 39, Fig. 3, 
 5, 6, 7). Some tribes are exclusively marine, 
 others live only in fresh-water, while many are re- 
 stricted to the brackish waters of estuaries. Their 
 geographical distribution is alike various : certain 
 
 v * Soft-bodied animals. f Shell-bearing animals. 
 
 J Having no head. 
 
202 THE WONDERS OF GEOLOGY. LECT. III. 
 
 forms (the cephalopoda) inhabit deep waters only, 
 and are provided with an apparatus by which they 
 can rise to the surface ; while others are littoral, 
 that is, live only in the shallows along the sea 
 shores ; many exist in quiet, others in turbulent 
 waters ; some are gregarious, like the oyster, while 
 others occur singly or in small groups. All these 
 varieties of condition are more or less strongly 
 impressed on their shelly coverings, which may 
 be considered as their external skeletons ; and the 
 experienced conchologist is enabled by the pecu- 
 liar characters of the shell, at once, to determine 
 the economy and habits of the animal, and con- 
 sequently the physical conditions in which it was 
 placed.* In this point of view, fossil shells become 
 objects of the highest importance to the geologist, 
 since they are frequently the only records of the 
 former condition of our planet. But I must return 
 from this digression, and proceed to the consider- 
 ation of the phenomena presented by the several 
 groups of the tertiary formations. 
 
 11. MlNERALOGICAL CHARACTERS OF THE TER- 
 TIARY SYSTEM. The predominating characters of 
 the tertiary system, as I have already mentioned, are 
 alternations of marine beds with those of lacustrine 
 and freshwater origin. A large proportion of the 
 strata is arenaceous, having intervening clays and 
 marls. Shingles, the remains of ancient sea- 
 
 * See an interesting paper on Shells, by Mr. Gray, of the 
 British Museum. Philosophical Transactions. 
 
11. CHARACTERS OF THE TERTIARY SYSTEM. 203 
 
 beaches, abound in some localities, and form either 
 a conglomerate or puddingstone, as that of Hert- 
 fordshire (page 88) ; or a ferruginous breccia, as at 
 Castle Hill, near Newhaven, on the Sussex coast. 
 The ruins of the chalk are everywhere recognisable 
 in the beds of water-worn flints, which contain shells 
 and zoophytes peculiar to the cretaceous system. 
 Large boulders of sandstone are of frequent occur- 
 rence, and may, perhaps, be referred to the newest 
 beds of the series. In the vicinity of Brighton, 
 blocks of ferruginous breccia are scattered over the 
 surface of the Downs, and masses of quartzose sand- 
 stone, of a saccharine structure, are seen at Falmer, 
 and in Stanmer Park : a remarkable rock of this 
 kind formerly existed in Goldstone Bottom, near 
 Brighton, but is now destroyed. In most of the 
 gravel beds around London there are numerous 
 blocks of silicious breccia and conglomerate, of 
 which there are many of considerable magnitude 
 on the grounds of John Allnutt, Esq. of Clapham 
 Common. In some of the tertiary formations, 
 limestone predominates, and alternates with sands 
 and marls of great variety and brilliancy of colour ; 
 beds of gypsum, and silicious nodules closely re- 
 sembling the flints of the chalk, also occur. Such 
 are the general features of this system of deposits, 
 which I shall now examine more in detail. 
 
 The distribution of the tertiary strata over 
 Europe, appears to be in areas more or less well 
 defined ; in our own island, there are the basins of 
 
204 THE WONDERS OF GEOLOGY. LECT. III. 
 
 London and Hampshire, and the remains of other 
 beds in Yorkshire, and in Norfolk and Suffolk. In 
 France, the metropolis is situated within the con- 
 fines of a tertiary basin ; and in the south and north 
 of that country, extensive tracts are formed of these 
 deposits ; in Auvergne, where they are associated 
 with ancient volcanic eruptions, they constitute a 
 district of unrivalled geological interest. In the 
 Sub- Apennines, they are largely developed ; and 
 in other parts of Sicily and Italy they insensibly 
 pass into vast beds, which are still in progress of 
 formation. 
 
 12. NEWER TERTIARY, OR PLIOCENE DEPOSITS. 
 From the large proportion of recent species of 
 shells which occur in some of the pliocene strata, 
 the beds have the appearance of a modern aggre- 
 gate, as the extensive and beautiful collection from 
 Palermo, before us (for which I am indebted to the 
 kindness of the Marquis of Northampton, P.R.S.) 
 well displays. A low range of hills, rising to an 
 elevation of about 200 feet above the level of the 
 Mediterranean, immediately behind Palermo, is in 
 a great measure constituted of coarse limestone, 
 formed of friable shells, which are frequently in 
 an admirable state of preservation ; white and 
 brittle in general, but in some examples preserving 
 their markings and natural polish. The elegant 
 and picturesque manner in which they are occa- 
 sionally grouped together, renders them objects of 
 great beauty and interest. These shells, with but 
 
12. NEWER TERTIARY DEPOSITS. 205 
 
 very few exceptions, belong to species still living 
 in the adjacent seas; a proof that when the lime- 
 stone was formed, the same condition of the basin 
 of the Mediterranean existed as at present, and 
 continued uninfluenced by the elevation of this 
 portion of its ancient bed. In other parts of Sicily, 
 limestone, blue marl, with shelly calcareous breccia, 
 and gypseous clay, intermingled with volcanic pro- 
 ducts, occur. The Val di Noto is particularly 
 mentioned by Mr. Lyell, as presenting a remark- 
 able assemblage of deposits ; * and I will quote 
 his lucid and highly graphic description. " The 
 rising grounds of the Val di Noto are separated 
 from the cone of Etna, and the marine strata on 
 which it rests, by the plain of Catania, which is 
 elevated above the level of the sea, and watered by 
 the Simeto. The traveller passing from Catania 
 to Syracuse, by way of Sortina and the valley of 
 Pentalica, may observe many deep sections of these 
 modern formations, which rise into hills from one 
 to two thousand feet in height, entirely composed 
 of sedimentary strata, with recent shells ; these are 
 associated with volcanic rocks. Tlie whole series 
 of strata, exclusively of the volcanic products, 
 is divisible into three principal groups. 1. The 
 uppermost, compact limestone in laminated strata, 
 with recent shells ; total thickness, from 700 to 
 800 feet. 2. Calcareous sandstone, with schistose 
 limestone. 3. Laminated marls and blue clays." 
 * Principles of Geology, vol. iii. p. 388. 
 
206 THE WONDERS OF GEOLOGY. LECT. III. 
 
 The above groups contain shells and zoophytes of 
 the same species as those from Palermo which I 
 have just noticed. The large scallop or pecten 
 (Pecten jacobceus), which at the present day is pro- 
 fusely strewn on the Sicilian shores, is also beau- 
 tifully preserved, and abundant in the compact 
 limestone. Leaves of plants and stems of reeds, 
 are of common occurrence. 
 
 13. CRAG OF NORFOLK AND SUFFOLK. On the 
 eastern coasts of Essex, Norfolk, and Suffolk, beds 
 of sand and gravel, abounding in shells and corals, 
 are superposed on the blue clay lying on the chalk, 
 and are distinguished by the name of Crag, a 
 provincial term signifying gravel. The late Mr. 
 Parkinson first described these strata, and in the 
 "Organic Remains of a Former World,"* figured 
 a shell which was formerly in much request among 
 collectors, the Essex reversed whelk (Fusus con- 
 trarius), in which the spiral convolutions pass from 
 right to left, instead of in the opposite and ordinary 
 direction. Here are several beautiful examples of 
 this fossil, collected by Sir Woodbine Parish ; they 
 all have the deep ferruginous colour which so com- 
 monly prevails in the fossils of the Crag. The 
 Crag first appears at Walton Nase, in Essex, and 
 constitutes the upper part of the cliffs on both sides 
 of Hanwell, varying from a few feet to thirty or 
 forty in thickness. It extends inland along the 
 Suffolk 'and Norfolk coast, forming a tract of at 
 * Vol. iii. pi. 6. fig. 5. 
 
IS. CRAG OF NORFOLK AND SUFFOLK. 207 
 
 least forty miles in length ; near Ipswich it is 
 spread over a considerable area, and abounds in 
 shells and other marine exuviae. The fossils which 
 I now place before you are from collections made 
 by the late Mrs. E. Cobbold, of Holywell Park, 
 near Ipswich ; Sir Woodbine Parish ; the late 
 Samuel Woodward, Esq.;* and Edward Charles- 
 worth, Esq., whose recent investigations have 
 thrown much light on the zoological characters of 
 these deposits. The Crag is divided into two 
 groups ; the lowermost, or coralline Crag, which 
 is composed of loose sand, and abounds in corals, 
 sponges, and shells, in so perfect a state as to 
 indicate that they lived and died on the spot where 
 their remains are entombed. This series is upwards 
 of fifty feet in thickness, and rests upon a layer of 
 blue clay, which will hereafter be noticed. The 
 uppermost, or Red Crag, so called from its deep 
 ferruginous colour, consists of sand with shells 
 which are generally broken and water-worn ; the 
 Norfolk Crag appears to be principally composed 
 of these upper beds. The fossils of the Crag are 
 extremely numerous ; they consist of several hun- 
 dred species of marine shells, some of extinct, but 
 the greater part of species now existing in the 
 German Ocean ; of corals, sponges, and more than a 
 hundred species of microscopic foraminifera ; with 
 teeth and scales of fishes. The collection of Crag 
 shells on the table was some years since examined 
 * Author of " Outlines of the GEOLOGY of NORFOLK." 
 
208 THE WONDERS OF GEOLOGY. LECT. III. 
 
 by Mr. Lyell, and M. Deshayes, a distinguished 
 French naturalist, by whom more than half the 
 species were considered to be of extinct forms; 
 and the remainder identical with species which now 
 inhabit the German Ocean.* 
 
 14. THE SUB-APENNINES. The Apennines, 
 that chain of hills which extends through the 
 Italian peninsula, are flanked, both on the side of 
 the Adriatic and the Mediterranean, by the Sub- 
 Apennines, a low range composed of tertiary marls, 
 sands, and conglomerates, abounding in marine 
 shells of those species and genera which prove that 
 some of the strata were cotemporaneous with the 
 Crag, and that others are referable to a more an- 
 cient epoch. These beds have resulted from the 
 waste of the secondary rocks, which form the 
 Apennines, and were dry land before those strata 
 were deposited. -j- 
 
 15. MIDDLE TERTIARY, OR MIOCENE DEPOSITS. 
 In the classification of Mr. Lyell, the term Mio- 
 cene designates those tertiary beds in which recent 
 species of shells occur, but in a much less pro- 
 portion than in the preceding division ; seldom 
 amounting to one-fifth of the whole. As there 
 are no good types of this group in Great Britain, 
 I shall merely observe, that marine and fresh-water 
 
 * Principles of Geology, vol. iv. p. 71. 
 
 f Brocchi, an eminent Italian naturalist, published many 
 years since a valuable work on the fossil shells of the Sub- 
 Apennines. 
 
16. LOWER TERTIARY, OR EOCENE DEPOSITS. 209 
 
 deposits possessing the characters here defined 
 occur near Bordeaux and Montpellier ; and in 
 Piedmont, Styria, Hungary, and other parts of the 
 European continent ; but in many instances the 
 strata seem to merge into one or other term of 
 the series. I proceed therefore to the consideration 
 of the Eocene, or those tertiary strata which are 
 of the highest antiquity, and are found deposited 
 in basins or depressions of the chalk, where that 
 formation constitutes the fundamental rock of the 
 country. Every step of our progress will now be 
 replete with the deepest interest, and new and 
 singular forms of being will appear before us. I 
 shall pass rapidly over the stratigraphical character 
 of these rocks, that our attention may be more fully 
 directed to the extraordinary organic remains which 
 they inclose. 
 
 16. LOWER TERTIARY, OR EOCENE DEPOSITS. 
 I propose, in the first place, to describe the geo- 
 graphical distribution and general characters of a 
 few principal groups of the older tertiary strata; 
 secondly, to investigate the nature of the more 
 remarkable fossil animals and plants ; and lastly, to 
 survey those regions of central France, of the Rhine, 
 and of South America, which have been the scenes 
 of active volcanoes during the tertiary epoch. 
 
 It may be regarded as a singular coincidence, 
 
 that the capitals of Great Britain and France are 
 
 located on strata of the same geological epoch. 
 
 Paris is situated on a vast alternation of marine 
 
 p 
 
210 THE WONDERS OF GEOLOGY. LECT. III. 
 
 and fresh-water beds, lying in a depression of the 
 chalk ; the latter forming the boundary of the area 
 in which the city is placed. London is built on 
 clays, sands, and shingles, also filling up a basin of 
 the chalk, which skirts the area of the tertiary strata 
 o"n the south, but is open to the sea on the east. In 
 Hampshire, a series of contemporaneous lacustrine 
 
 TAB. S3. TERTIARY BASINS OF PARIS, LONDON, AND HANTS. 
 (From Mr. Webster's Map in the Geological Transactions.) 
 
 deposits, with interspersions of marine remains, in 
 like manner rest upon the chalk, and constitute the 
 basin of the Isle of Wight. The relative situation 
 and comparative extent of these three groups are 
 shown in the map (Tab. 33), reduced from that 
 
17. THE PARIS BASIN. 211 
 
 which accompanied Mr. Webster's first announce- 
 ment of the characters of the British tertiary for- 
 mations; and this section, by Mr. Lyell (Tab. 34-), 
 from Hertfordshire across the British Channel, to 
 Sens in France, explains the position of the London 
 and Paris basins, and the underlying secondary 
 formations. 
 
 Valley of Bray. PARIS. 
 
 3 3 
 
 TAB. 34. SECTION FROM HERTS, TO SENS, IN FRANCE. 
 
 (From Ly ell's Elements of Geology.) 
 
 1. Chalk. 2. Green sand. 3. Wealden. 
 
 The shaded sites of London and Paris indicate the tertiary deposits. 
 
 17. THE PARIS BASIN. The Paris basin is 
 from east to west about 100 miles in extent, and 
 180 from north-east to south-west; the total thick- 
 ness of the beds, or, to use other terms, the depths 
 passed through to reach the chalk, varying from one 
 to several hundred feet. 
 
 The strata, commencing with the lowermost, or 
 most ancient, present the following characters : 
 
 1. The lowermost. Chalk flints, broken, and par- 
 tially rolled, sometimes conglomerated into ferru- 
 ginous breccia. A layer of this kind is very 
 common on the South Downs, immediately under 
 the turf. 
 
 2. Plastic clay, and sand. Clay and sand, with 
 fresh-water shells, drifted wood, lignite, leaves, and 
 
212 THE WONDERS OF GEOLOGY. LECT. III. 
 
 fruits ; intercalated with limestone containing ma- 
 rine shells. 
 
 3. Silicious limestone, fresh-water and terrestrial 
 shells and plants, and marine limestone, or Calcaire 
 grassier, a coarse compact limestone, passing into 
 calcareous sand, and abounding in marine shells. 
 These beds often alternate, and are considered by 
 M. Constant Prevost to be contemporaneous for- 
 mations ; the marine strata having been formed in 
 those parts of the basin which were open to the 
 sea ; and the fresh-water limestone, by mineral 
 waters poured into the bay from the south ; the 
 continent being situated then, as now, to the south, 
 and the ocean to the north. Partial layers of 
 milliolite limestone,* almost entirely composed of 
 microscopic chambered shells, occur in this part 
 of the basin. 
 
 4. Gypseous marls, and limestones, with bones of 
 animals, and fresh-water shells of fluviatile origin. 
 These are supposed to have been discharged by a 
 river which flowed into the gulf; the gypsum being 
 precipitated from water holding sulphate of lime 
 in solution, in the same manner as the travertine 
 or calcareous tufa, of which we have already spoken 
 (page 56.) 
 
 5. Upper marine formation, consisting of marls, 
 micaceous and quartzose sand, with beds of sand- 
 stone abounding in marine shells. 
 
 * So called from its inclosing immense quantities of a minute 
 shell, named Milliolite. 
 
 
} 18. THE LONDON BASIN. 213 
 
 6. Upper fresh-water marls, with interstratified 
 layers of flint, containing seed-vessels of aquatic 
 plants ( Charce), and animal and vegetable remains. 
 These beds are attributed to lakes or marshes, 
 which existed after the marine sands had filled up 
 the basin. 
 
 From this rapid sketch, we perceive that the strata 
 which occupy the Paris basin, have been produced 
 by a succession of changes that readily admits of 
 explanation by the principles so ably enforced by 
 Hutton, Playfair, and Lyell, and explained in the 
 previous lecture. Here we have an ancient gulf of 
 the chalk, which was open to the sea on one side, 
 while on the other it was supplied by rivers charged 
 with the spoils of the country through which they 
 flowed, and carrying down the remains of animals 
 and plants, with land and river shells ; and there 
 were occasional introductions of mineral waters. 
 Changes in the relative level of the land and sea 
 took place, and thus admitted of new accumulations 
 upon the previous deposits ; lastly, the country was 
 elevated to its present altitude above the sea. Muta- 
 tions of this kind, as we have already seen, are in 
 progress at the present moment, and afford a satis- 
 factory elucidation of these interesting phenomena. 
 I reserve my remarks on the fossils of the Paris basin 
 to the next section, and pass to the examination of 
 the analogous beds in our own island. 
 
 18. THE LONDON BASIN. The tertiary strata 
 on which the metropolis of England is situated are 
 
214 THE WONDERS OF GEOLOGY. LECT. III. 
 
 spread over a considerable area, which is bounded 
 on the south by the North Downs ; extends on the 
 west beyond High-elm hill, in Berkshire ; and on 
 the north-west is flanked by the Chalk hills of 
 Wiltshire, Berkshire, Oxfordshire, Buckingham- 
 shire, and Hertfordshire. On the east it is open to 
 the sea ; the Isle of Sheppey, situated in the mouth 
 of the Thames, being an outlier of the same deposit.* 
 It spreads over Essex, a considerable part of Suf- 
 folk, Epping and Hainault forests, the whole of 
 Middlesex, and a portion of Bucks. In the imme- 
 diate vicinity of the metropolis, a stiff clay of a 
 bluish-black colour, abounding in marine remains, 
 constitutes the great mass of the materials which 
 fill up this ancient gulf of the ocean. Immediately 
 upon the chalk, however, there occur thick beds of 
 sand and clay, called Plastic clay (from its analogy 
 to the Argile Plastique of the Paris basin), in which 
 fresh-water shells, plants, and drifted wood, have 
 been found in some localities. In other instances, 
 layers of green sand lie upon the chalk, which at 
 Reading contain immense quantities of oyster- 
 shells: a similar accumulation of shells has been 
 observed at Headley, in Surrey, a few miles from 
 Reigate, by Mr. Peter Martin, jun. of that town. 
 At Bromley, in Kent, there is a bed of oyster-shells 
 with pebbles of chalk-flints, which are cemented 
 together by a calcareous deposit into a remarkable 
 
 * See Mr. Webster's paner in the Geological Transactions ; 
 and Conybeare and Phillips' s Geology of England and Wales, 
 
5 IS. THE LONDON BASIN. 215 
 
 conglomerate, in much request for grottoes and 
 ornamental rock-work. The London clay is found 
 immediately beneath the gravel which so generally 
 forms the sub-soil of the metropolis ; it is of great 
 extent, and varies from 300 to 600 feet in thickness. 
 This clay forms a dark, tough soil, and has occa- 
 sional intermixtures of green and ferruginous sand, 
 and variegated clays. It abounds in spheroidal 
 nodules of indurated argillaceous limestone, in- 
 ternally filled by veins of calcareous spar, or sul- 
 phate of barytes, disposed in a radiating manner 
 from the centre of the nodule to the circumference. 
 From the appearance of partitions which this cha- 
 racter confers, these concretions are commonly 
 known by the name of Septaria : shells and other 
 organic remains frequently form the nucleus of 
 these nodules, which are used in prodigious quan- 
 tities for cement. The specimens on the table are 
 from Highgate and Bognor ; two from the latter 
 locality, presented to me by Dr. Hall, contain 
 beautiful examples of an extinct species of nautilus. 
 The septaria are commonly disposed in horizontal 
 lines, and lie at unequal distances from each other. 
 Brilliant sulphuret of iron abounds in the clay, 
 and is sjeen in this septarium, as well as in many of 
 the organic remains. Crystallized sulphate of lime, 
 or selenite, is also common in these as in other ar- 
 gillaceous strata. The cuttings through Highgate 
 Hill, to form the archway ; the excavations in the 
 Jlegent's Park; and more recently the tunnels 
 
216 THE WONDERS OF GEOLOGY. LECT. III. 
 
 carried through a part of the same ridge of clay 
 at Primrose Hill, in the line of the Birmingham 
 railroad ; and the explorations, by wells, over the 
 whole area around London, have brought to light 
 such prodigious quantities of organic remains, that 
 the fossils of this deposit are almost universally 
 known. The admirable work of the late Mr. 
 Sowerby, called early attention to these testaceous 
 remains, the first plate in his Mineral Conchology 
 being devoted to the " Nautili of the London Basin." 
 Immense numbers of marine shells of extinct spe- 
 cies ; crabs, lobsters, and other Crustacea ; teeth 
 of sharks, and remains of many genera of fishes ; 
 bones of crocodiles and turtles; leaves, fruits, stems 
 of plants, and rolled trunks of trees, perforated by 
 boring shells, occur throughout these strata, but 
 are located in greater abundance in some spots than 
 in others. The clay and gravel pits at Woolwich, 
 on the banks of the Thames, abound in univalve 
 shells ; and at Plumstead, Bexley, and other places, 
 marine bivalve shells occur in clay, and in indurated 
 argillaceous limestone. 
 
 19. THE ISLE OF SHEFPEY. The Isle of Sheppey 
 is entirely composed of the London clay, and the 
 thickness of the beds is upwards of 550 feet. It has 
 long been celebrated for its organic remains ; and 
 I may observe, that the discovery of seed-vessels 
 and stems of plants in pyritous clay, in a visit which 
 I made to Queenborough, when a youth, tended to 
 confirm my early taste for geological researches. 
 
20. FOSSIL FRUITS OF THE TERTIARY STRATA. 217 
 
 The cliffs on the north of the island are about 
 200 feet high, and consist of clay, abounding in 
 septaria, which are washed out of the cliffs by the 
 action of the sea, and are collected for cement. 
 The organic remains are, however, unfortunately 
 so strongly impregnated with pyrites, that the col- 
 lector often finds the choicest fossil fruits in his 
 cabinet, like the fabled apples of the Dead Sea, one 
 moment perfect and brilliant, and the next decom- 
 posed and changed to dust, leaving only an efflo- 
 rescent sulphate of iron. The same species of 
 animal and vegetable remains that are found in 
 the blue clay of the metropolis, abound in profusion 
 in the Isle of Sheppey. 
 
 20. FOSSIL FRUITS OF THE TERTIARY STRATA. 
 
 Seed-vessels, and stems and branches of trees, of a 
 tropical character, probably drifted by currents into 
 the gulf of the London basin, occur in such abun- 
 dance and variety, that the existence of a group of 
 spice islands seems necessary to account for so vast 
 an accumulation of vegetable productions. The 
 seed-vessels found at Sheppey are referable to 
 several hundred species ; some are related to the 
 cardamom, date, areca, cocoa; and one species of 
 berry bears much resemblance to the fruit of the 
 coffee. The wood found in the Sheppey clay is 
 generally of a dark colour, with the ligneous fibres 
 and circles of growth well developed ; it is often 
 veined with brilliant pyrites, and the fissures and 
 cavities are frequently filled with that mineral. It 
 
218 THE WONDERS OF GEOLOGY. LECT. III. 
 
 is rarely that any considerable mass of wood is 
 found free from the ravages of a species of teredo, 
 resembling the recent teredo navalis, or borer, which 
 inhabits the seas of the West India islands. The 
 tubular shells sometimes remain, but their cavities, 
 as well as the perforations in the wood, are filled 
 with pyrites, indurated clay, argillaceous limestone, 
 or calcareous spar ; and specimens, when cut and 
 polished, exhibit interesting sections of the mean- 
 dering grooves of the teredines. In this specimen, 
 from the banks of the canal in the Regent's Park, 
 the grain of the wood, with the shells, and their 
 excavations, are beautifully displayed. 
 
 21. UPPER MARINE, or BAGSHOT SAND. At 
 Highgate and Hampstead, Purbright and Frimley 
 Heaths, in Surrey, and on Bagshot Heath, extensive 
 beds of sand occur, with but few traces of organic 
 remains ; those hitherto observed are principally 
 x;asts of marine shells. In cutting through the 
 summit of Goldworth hill, four miles north of Guild- 
 ford, on the line of the London and Southampton 
 railway, teeth and other remains of several genera 
 of fishes have lately been discovered ; the teeth of 
 sharks, and the palates of rays, are the most nume- 
 rous. One large tooth of a saw-fish, affords the 
 first well-authenticated example of the genus pris- 
 tris, in a fossil state, in England ; and there have 
 also been found teeth of several new genera of 
 cartilaginous fishes^ related to psammodus.* The 
 . * Proceedings of the Geological Society, vol. ii. p. 687. 
 
122. ARTESIAN WELLS. 219 
 
 boulders and masses of sandstone, which are abun- 
 dant in some of the chalk valleys and on the flanks 
 of the Downs, are called Sarsden- stone, or Druid 
 sandstone, from being the principal material em- 
 ployed in the construction of Stonehenge, and other 
 Druidical monuments ; they are supposed to have 
 been derived from the sand-beds, which overlie the 
 London clay in the places above named ; they may, 
 however, have belonged to the sands which lie be- 
 tween the clay and chalk. The wastes and unpro- 
 ductive heaths around the metropolis, are sites of 
 these arenaceous deposits, which also form the sub- 
 soil of that charming and picturesque spot, Hamp- 
 stead Heath. The gravel and shingle, associated 
 with the sands, have unquestionably been derived 
 from the ruins of the chalk formation. 
 
 22. ARTESIAN WELLS. As from the alternation 
 of porous, arenaceous strata, with stiff or impervious 
 JDeds of clay, the artificial perennial fountains, called 
 Artesian wells, are of frequent occurrence in the 
 vicinity of the metropolis, I will in this place offer 
 a few remarks on the phenomena of springs. The 
 descent of moisture from the atmosphere upon 
 j;he earth, and its escape into the basin of the 
 ocean, by the agency of streams and rivers, were 
 noticed in the first lecture. The rain falling on a 
 gravelly or porous soil, will, of course, descend 
 through it, till its progress is arrested by a clayey or 
 impervious stratum, which will thus form a natural 
 tank or reservoir, collect the water, and a subter- 
 
220 THE WONDERS OF GEOLOGY. LECT. III. 
 
 ranean pool or canal will be the result, according 
 to the direction and configuration of the upper 
 surface of the clay. This state of things will con- 
 tinue, till, by an increased supply, the water rises 
 above the level of the basin, or channel, and over- 
 flowing, escapes, either through the porous strata, 
 or by fissures in the solid rocks, to another level. 
 If the course of the waters be subterranean, the 
 softer beds are worn away, and chasms or caverns 
 are thus formed, hence rivers and streams, of great 
 extent, occur in many of our mines ; but if the water 
 finds its way to the surface, a spring bursts forth. 
 This is the nature of all springs, except those w r hich 
 arise from great depths, and probably originate 
 from the condensation of steam, evolved through 
 fissures by volcanic agency j such are the thermal 
 waters of many countries. Streams impregnated 
 with the mineral substances contained in the strata 
 through which they flow, are called mineral waters. 
 Those in the tertiary strata near Epsom, contain 
 sulphate of magnesia, whence the name of Epsom 
 salt, given to this substance wherever it occurs. 
 But strata which are pervious, frequently alternate 
 with others which are not so ; or may form a basin, 
 the area of which is partially filled with clay, through 
 which water cannot pass : in such a case, it is ob- 
 vious that the bed of sand beneath the clay, fed by 
 the rain which descends on the uncovered margin 
 of the basin, must form a reservoir, and the water 
 gradually accumulate beneath the central plateau 
 
22. ARTESIAN WELLS. 221 
 
 of clay, through which it cannot escape. If this 
 bed of clay be penetrated, either by natural or arti- 
 ficial means, the water must necessarily rise to the 
 surface, and may be even thrown up in a jet to an 
 altitude which will depend on the level of the fluid 
 in the subterranean reservoir ; such is the pheno- 
 menon observable in the Artesian wells around 
 London. Argillaceous strata are generally found 
 to be dry within ; and the blue clay confines the 
 water contained in the sands beneath ; the engineer 
 perforates the clay, introduces tubes, and taps the 
 natural tank ; by this method, the perennial foun- 
 tains of Tooting, Hammersmith, Fulham, &c. have 
 been obtained.* The wells sunk into the London 
 
 3 LONDON. 
 
 a b d c b d c 
 
 TAB. 35. PLAN OF THE ARTESIAN WELLS NEAR LONDON. 
 1. The London clay. 2. Plastic clay and sand. 3. The chalk. 
 
 clay (Tab. 35, 1, d, d,) yield no water; but the 
 sandy strata alternating with the clays, afford a 
 supply, the quantity and quality of which depend on 
 the nature of the rock. The borings, which reach 
 
 * Consult Dr. Buckland's Bridgewater Essay, p. 561 ; and 
 an admirable Essay on Artesian Wells, in that excellent scien- 
 tific periodical, the Mining Journal, conducted by H. English, 
 Esq., F.G.S. 
 
222 THE WONDERS OF GEOLOGY. LECT. III. 
 
 the sands of the plastic clay (Tab. 35, 2, c, c t ) fur- 
 nish good soft-water ; and the wells that extend 
 to the chalk (Tab. 35, 3, a, b, b,) afford an abun- 
 dant supply, which often rises to the surface in 
 a perennial fountain, for the chalk rests on an im- 
 pervious bed of marl and clay. Of the practical 
 utility of geological knowledge, even in the common 
 operation of sinking a well, I once had a striking 
 proof. A gentleman residing in Sussex, on the 
 borders of the Forest Ridge, who had seen with 
 admiration the perpetual springs in the environs of 
 the metropolis, determined to form one in his grounds 
 
 at Park. Accordingly, a person conversant 
 
 with the construction of the Artesian wells around 
 London was employed, and the necessary apparatus 
 obtained : but the engineer, being wholly ignorant 
 of the nature of the strata, carried his operations to 
 a great depth, through the beds of the wealden 
 sand of which the district is composed, and, of 
 course, without success, as the least geological 
 knowledge of the strata of the country would have 
 foretold. The undertaking, after considerable 
 labour and expense, was abandoned. 
 
 23. THE HAMPSHIRE, OR ISLE OF WIGHT BASIN. 
 The London basin presents but little analogy to 
 the alternate marine and freshwater deposits of that 
 of Paris ; but in Hampshire and the Isle of Wight, 
 there is an extensive suite of tertiary strata, com- 
 posed of clays, sands, and limestones, containing 
 freshwater, with intercalations of marine remains. 
 
24. ALUM BAY. 22,'J 
 
 This group extends over a considerable district. 
 On the east, a small outlier of the lower beds 
 appears at Castle Hill, near Newhaven, in Sussex ;* 
 but to the westward of Brighton, beyond Wor- 
 thing, the London clay rises to the surface, and 
 forms the sub-soil between the Downs and the 
 sea-shore. The inland boundary stretches by Chi- 
 chester, Emsworth, and Southampton, to Dorches- 
 ter ; and the clay is spread over the whole area of 
 the New Forest and the Trough of Poole, being 
 flanked by the chalk on the north, north-east, and 
 north-west, and open to the sea on the south. The 
 Isle of Wight, although now separated from the 
 main land, is a disrupted mass of the formations of 
 the south-east of England ; the chalk basin having 
 been broken up, and the chalk and the superim- 
 posed sands, clays, and gravel, in some instances, 
 thrown into a vertical position. A remarkable and 
 well-known instance of this phenomenon occurs at 
 Alum Bay, so called from the alum, formerly ex- 
 tracted from the decomposing pyrites, with which 
 the clay abounds. 
 
 24. ALUM BAY. This sketch (Tab. 36) conveys 
 a general outline of the bay ; o, represents the ver- 
 tical chalk ; b, b, the corresponding tertiary strata, 
 consisting of sands and clays of an infinite variety of 
 colour, and containing abundance of shells. Advan- 
 tage is taken of the diversified tints of the sands to 
 represent, in glass vessels, landscapes of the island, 
 * Geology of the South-East of England, p. 53. 
 
221 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. III. 
 
 which are sold to visitors. The appearance of Alum 
 Bay is thus graphically described by Mr. Webster, 
 whose able memoir on the strata above the English 
 chalk, formed a new era in British Geology, and 
 raised our tertiary series to an importance equal to 
 
 TAB. 36. ALUM BAY, ISLE OF WIGHT. 
 a, vertical strata of chalk, b, b, vertical tertiary strata. 
 
 that of the Paris basin. " The clays and sands of 
 Alum Bay afford one of the most interesting natural 
 sections imaginable. They exhibit the actual state of 
 the strata immediately above the chalk, before anv 
 change took place in the position of the latter. For, 
 although the beds of which they are composed are 
 quite vertical, yet from the nature and variety of 
 their composition, and the regularity and number of 
 their alternations, no one who views them can doubt 
 
25. LONDON CLAY OF THE HAMPSHIRE BASIN. 22"> 
 
 that they have suffered no change, except that of 
 having been moved with the chalk from a horizontal 
 to a vertical position. These sands and clays pre- 
 sent every variety of colour of green, yellow, red, 
 crimson, ferruginous, white, black, and brown." 
 Beds of pipe-clay also occur ; some of which con- 
 tain layers of wood-coal, with branches and leaves. 
 The coal burns with difficulty, and emits a strong 
 sulphureous smell ; masses are constantly drifted 
 by the sea and thrown on the shore near Brighton, 
 where this substance was formerly used as fuel by 
 the poorer inhabitants.* 
 
 25. LONDON CLAY OF THE HAMPSHIRE BASIN. 
 The London clay extends over the greater portion 
 of the area of the Hampshire basin, its peculiar 
 fossils abounding in many localities. Castle Hill, 
 near Newhaven, which has been already mentioned, 
 is a series of sands, marls, and clays, with beds of 
 oyster-shells and of shingle that occupy the upper 
 part of the hill, and rest upon the chalk which forms 
 the lowermost fifty feet of the cliff. The sub- 
 sulphate of alumine,-^ a mineral substance peculiar 
 
 this locality, occurs in the ochraceous clay which 
 is in immediate contact with the chalk. Selenite, 
 or crystallized gypsum, abounds in the gypseous 
 marls; a layer of surturbrand, or wood-coal, a 
 few inches thick, contains impressions of land- 
 
 * See Geology of the South Downs, p. 261. 
 t British Mineralogy, Tab. 499. Geology of the South- 
 East of England, p. 56. 
 
 Q 
 
226 THE WONDERS OF GEOLOGY. LECT. III. 
 
 plants ;* and the argillaceous beds contain marine 
 and fresh-water shells in such abundance, that some 
 of them are mere masses of compressed shells, held 
 together by argillaceous earth. The oysters are con- 
 solidated into coarse stone, and where pebbles enter 
 into the composition of this concrete, a close resem- 
 blance is presented to the Bromley oyster conglo- 
 merate (p. 214). Teeth of sharks have been collected 
 in these strata. At Chimting Castle, near Seaford, 
 on the eastern escarpment of the valley of the Ouse, 
 olive-green sand, and a ferruginous conglomerate 
 of chalk-flints, lie upon the chalk, thus determining 
 the original extension of the tertiary beds along 
 the Sussex coast.-)- Westward from Brighton, the 
 London clay is perceived near Worthing, emerging 
 from beneath those newer deposits which, as we 
 have already seen, contain remains of elephants. 
 At Bognor, an arenaceous limestone, full of the 
 usual shells of the Calcaire grassier and London 
 clay,J constitutes a group of low rocks, which in 
 another century will probably have entirely dis- 
 appeared. The beauty and variety of the shells, 
 particularly of the nautili, and of the perforated 
 fossil wood, render these organic remains objects 
 of great attraction. In the blue clay at Bracklesham 
 Bay, and at Stubbington, on the western coast of 
 Sussex, fossil shells may be obtained at low- water 
 
 * Fossils of the South Downs, PI. viii. figs. 1, 2, 3, 4. 
 f Geology of the South-East of England, p. 62. 
 J Fossils of the South Downs, p. 271. 
 
} 26. FRESH- WATER STRATA OF THE ISLE OF WIGHT. 227 
 
 in profusion; and Hordwell Cliff, in Hampshire, 
 has so long been celebrated for similar productions, 
 that its elegant shells are seen in almost every col- 
 lection of organic remains. In all these localities 
 the shells are of the same genera and species with 
 those of the contemporaneous deposits of France. 
 
 26. FRESH-WATER STRATA OF THE ISLE OF 
 WIGHT. The great peculiarity and interest of the 
 Isle of Wight basin, as compared with that of 
 London, consists in the existence of strata con- 
 taining almost exclusively fresh-water shells and 
 remains of the same kind of animals as those which 
 occur in the vicinity of Paris. Mr. Webster arranged 
 the tertiary beds of Hampshire, in the following 
 manner: 1st. Lowermost; Plastic clay and sand. 
 2d. London clay. 3d. Fresh- water deposits, 
 sandy calcareous marls, with immense quantities of 
 fresh- water shells. 4th. Clay and marl, abounding 
 in marine shells ; very generally of different species 
 from those of the London clay. 5th. Upper fresh- 
 water deposit; yellowish white marl, and calcareous 
 limestone, employed for building ; nearly sixty feet 
 in thickness, and almost one entire mass of fresh- 
 water shells. 
 
 Subsequent observations have shown that the 
 above subdivisions have been made from too partial 
 a view of the phenomena, and that the entire suite 
 of deposits must be regarded as a fresh-water for- 
 mation, into which there have been occasional 
 irruptions of the sea. 
 
 Q2 
 
228 THE WONDERS OF GEOLOGY. LECT. III. 
 
 The above series is well developed at Headon 
 Hill, where the fresh-water strata, which succeed 
 those of Alum Bay, lie in a nearly horizontal 
 
 Headon Hill. Alum Bay. 
 
 1 2 
 
 TAB. 37. SECTION OF HEADON HILL AND ALUM BAT. 
 
 Fig. 1. The horizontal fresh-water beds of Headon Hill. 2. Vertical 
 tertiary strata of Alum Bay. 3. Almost vertical beds of chalk. 
 
 direction. At Binstead, near Calbourne, and 
 Morley, quarries have been opened in the fresh- 
 water limestone ; and bones and teeth of Anoplo- 
 therict, Palceotheria, of the Chiropotamus an animal 
 allied to the Peccari, and of a species of Moschus, 
 have been discovered. 
 
 27. ORGANIC REMAINS OF THE PARIS, LONDON, 
 AND HANTS BASINS. So numerous are the relics 
 of the inhabitants of the ancient land and water 
 entombed in the strata which we have thus cur- 
 sorily surveyed, that I can only attempt a brief 
 description of the organic remains. To condense 
 my remarks as much as possible, I shall select the 
 fossils of the Paris basin as the types of the zoology 
 of the older tertiary epoch, and include notices of 
 such species as, occurring in British and other 
 localities, may be requisite for the illustration of 
 the subject. 
 
28. FOSSIL PLANTS AND ZOOPHYTES. 221) 
 
 28. FOSSIL PLANTS AND ZOOPHYTES. Fossil 
 
 wood occurs in vast abundance, particularly in the 
 state of large trunks and branches, which appear 
 to have been drifted, and are full of perforations 
 inclosing shells of boring mollusca. Bognor rocks, 
 the clay around London, of the Isle of Sheppey, c. 
 abound in specimens of this kind. The wood is 
 dicotyledonous, that is, like the oak, ash, &c. ; its 
 mode of increase was by annular circles of growth, 
 as will be explained in the lecture on Fossil Botany. 
 Leaves and stems of palms have been found in the 
 Paris basin, and in the Isle of Sheppey, &c.; and a 
 trunk of a tree related to the palm, nearly four feet 
 in diameter, at Soissons. Fruits belonging to trees 
 allied to the areca, pine, fir, cocoa-tree, &c. have 
 been discovered in several localities. Accumula- 
 tions of vegetable matter, in the state of lignite or 
 brown coal, occur at Bovey Tracey in Devonshire, 
 and in various parts of France, the Netherlands, &c. 
 Amber, and a substance which has been called 
 Highgate resin, are occasionally imbedded in these 
 deposits. 
 
 ZOOPHYTES. Polyparia, or corals, occur in 
 some of the marine strata, but they are not very 
 numerous ; several species of turbinolia, caryo- 
 phyllia, fungia, and other corals, are figured and 
 described by authors. I have a few specimens 
 from Grignon. The modern tertiary (those of 
 Palermo) abound in various kinds of flustra and 
 spongia. 
 
230 THE WONDERS OF GEOLOGY. LECT. III. 
 
 29. MARINE AND FRESH-WATER SHELLS OF 
 THE TERTIARY STRATA. So numerous are the 
 shells of the tertiary epoch, already determined by 
 naturalists, that they exceed one-half of the known 
 living species, amounting to nearly three thousand. 
 We have already seen that some of the strata are 
 almost entirely composed of these remains in a 
 broken and compressed state : at Newhaven, in 
 Sussex, many seams in the argillaceous beds wholly 
 consist of shell-dust. In other localities the shells 
 occur in the most perfect state; and Grignon, a 
 few leagues from Paris, has long been celebrated 
 for its beautiful fossils, hundreds of species of 
 shells peculiar to the older tertiary strata having 
 been collected in one spot alone : these belong to 
 the Calcaire grassier, and many of the species occur 
 in the London and Hampshire basins, and Bognor 
 rocks. I have selected a few specimens, from those 
 in my possession, to convey an idea of their usual 
 characters and appearance. (Tab. 38.) 
 
 Although, in mentioning the names of these 
 shells, I do not expect that any but the scientific 
 inquirer will endeavour to fix them on the memory, 
 yet it is useful to point out to you the characters 
 which prevail in these tertiary beds ; for, as I have 
 already stated, certain fossils are peculiar to certain 
 strata, and the experienced geologist can often, at a 
 glance, determine the relative antiquity of a deposit 
 by an examination of a few species of shells. The 
 whole of these forms must be familiar to you, 
 
29. 
 
 SHELLS OF THE TERTIARY STRATA. 
 
 231 
 
 because they belong to genera which have species 
 still living in our present seas. The Cyprtea, or 
 cowry (tig. 1), and the Anci/la, or olive, (fig. 2), 
 
 TAB. 38. MARINE SHELLS OF THE PARIS BASIN. 
 
 ?. 1. Cyprsea inflata. 2. Ancilla canalifera. 3. Fusus uniplicatus. 
 4. Cerithium laraellosum. 5. Pleurotoma dentata. 6. Lucina sulcata. 
 7. Ampullaria sigaretina. 8. Pectunculus angusti-costatus. 
 
 are well-known types. The Cerithium (fig. 4) 
 belongs to a genus which is most abundant in the 
 sands of the Paris basin, and is remarkable for the 
 
THE WONDERS OF GEOLOGY. 
 
 LECT. III. 
 
 elegance, number, and variety of the species, which 
 exceed by three times those of their living ana- 
 logues. The Cerithium giganteum attains a con- 
 siderable magnitude. Some masses of the Bognor 
 rock are almost wholly composed of a species of 
 Pectunculus. The Ampullaria (Tab. 38, fig. 7) 
 abounds at Grignon, and is commonly in a beau- 
 tiful state of freshness. You will recollect that in 
 most of the carnivorous species the aperture of the 
 shell is channelled. (Tab. 38, figs. 2, 3, 4, 5.) 
 1 2 
 
 TAB. 39. FRESH-WATER SHELLS OF THE PARIS BASIN. 
 
 Figs. 1, 2. Bulimus conicus. 3,4. Cyclostoraa mumia. 5. Lymnea 
 
 effilea. 6, 7, 8. Planorbis. 
 
 FRESH-WATER TERTIARY SHELLS. It has al- 
 ready been observed, that the shells of the mollusca 
 
 
30. NUMMUL1TES. 233 
 
 which inhabit fresh water, possess characters by 
 which they may be distinguished from the marine 
 species. This small selection from the fresh-water 
 beds of Paris will serve to elucidate my observa- 
 tions. The general appearance of these shells will 
 bring to your recollection the species which inhabit 
 our ponds and rivers ; particularly the large thiu 
 snail (lymnea, fig. 5) and the discoidal shells {plan- 
 orbis, figs. 6, 7, 8) ; while figs. 3 and 4> (cyclostoma) 
 resemble a species often found on the banks of 
 lakes. At Headon Hill, and at Binstead in the 
 Isle of Wight, the clay and limestone are filled 
 with the remains of several species of planorbis 
 and lymnea. 
 
 30. NUMMULITES, AND OTHER CEPHALOPODA. 
 
 Several species of nautilus abound in the tertiary 
 strata ; those inclosed in the septaria, or indurated 
 argillaceous nodules, of the London clay at High- 
 gate, Sheppey, and Bognor, possess considerable 
 beauty, and admit of being cut in sections, which 
 admirably display the internal structure of the 
 original. I shall, however, defer an explanation of 
 their mechanism to the subsequent lecture, when 
 analogous fossil genera will come under our notice. 
 My observations will now be restricted to an in- 
 teresting division of the Cephalopoda (as those 
 mollusca are termed whose head is surrounded by 
 the organs of motion, or feet), called Foraminifera, 
 which comprehends many genera, and several hun- 
 dred species, the greater part being microscopic, 
 
234 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT.III. 
 
 and analogous to the recent forms which inhabit 
 the Mediterranean. These bodies are entirely 
 distinct from the testaceous habitations of snails, 
 periwinkles, &c. : they are, in truth, not an ex- 
 ternal, but an internal apparatus; and it is sup- 
 posed, that, in addition to their having served as 
 a point of attachment and support to the soft 
 body of the animal, they acted as a buoy, which 
 could be made heavier or lighter at pleasure, and 
 by which the animal was enabled either to sink 
 
 TAB. 40. NUMMULITES, FROM THE GREAT PYRAMID OF EGYPT. 
 (Collected by Dr. George Hall, of Brighton.) 
 
 Fig. 1. Transverse section of a Nummulite. 2, 3. Nummulites, with the 
 external plate partially removed. 
 
 or swim. The fossil called Nummulite (from its 
 resemblance to a coin) affords a beautiful illus- 
 
30. NUMMULITES OF THE PYRAMIDS. 235 
 
 tration of the structure of these bodies. It is 
 of a lenticular, discoidal form, and varies in size 
 from a mere point to an inch and a half in diameter. 
 The outer surface is generally smooth, and marked 
 with fine undulating lines- On splitting the shell 
 transversely, it is found to consist of several coils, 
 which are divided into a great many cells or cham- 
 bers by oblique partitions (Tab. 40, fig. 1), appa- 
 rently having no communication with each other, 
 but which the animal, probably, had the power of 
 filling with fluid, or air, through foramina or pores ; 
 whence the name of the order. To Dr. George 
 Hall (physician to the Sussex Hospital), I am in- 
 debted for the specimens exhibiting this structure, 
 which I now place before you (Tab* 40) ; they are 
 from the limestone formed of nummulites, held 
 together by calcareous cement, which constitutes 
 the foundation rock of the Great Pyramid of Egypt, 
 and of which that structure is in part composed. 
 Strabo alludes to the nummulites of the pyramids, 
 under the supposition that they are lentils which 
 had been scattered about by the workmen, and 
 become converted into stone.* This polished, sili- 
 cious pebble, presented me by the Marquess of 
 Northampton, is also from Egypt; the markings 
 on the surface are sections of the inclosed shells. 
 The uummulite is one of the most widely diffused 
 of fossil shells, its remains forming whole chains of 
 
 * See Wilkinson's Manners and Customs of the Ancient 
 Egyptians, vol. ii. p. 371. 
 
236 THE WONDERS OF GEOLOGY. LECT. III. 
 
 calcareous hills : it is not confined to the tertiary, 
 but occurs also in the secondary formations, and 
 constitutes immense beds in the Alps and Pyrenees. 
 The blue clay at Bracklesham and at Stubbington, 
 and the calcareous sandstone of Emsworth and 
 Bognor, in Sussex, abound in nummulites. In 
 North America, the limestone which occurs near 
 Suggsville, and forms a range of hills about 300 
 feet in height, is entirely composed of one species 
 of nummulite. This limestone is porous, and con- 
 tains spheroidal cavities formed by the decompo- 
 sition of the organic remains.* 
 
 31. CRUSTACEA AND FISHES. Crabs and lob- 
 sters, of species related to the recent, several of 
 which are described by MM. Brongniart and Des- 
 marest, in their beautiful work on Fossil Crustacea, 
 have been found in the clay of Highgate, and in 
 the Isle of Sheppey. The external configuration of 
 the shell or crustaceous covering of these animals 
 being in conformity to the viscera which they in- 
 close and are intended to protect, the naturalist is 
 able, by au accurate acquaintance with the charac- 
 ters of the living species, to point out the relation 
 or difference of the fossil, even though the cara- 
 pace or buckler alone remains ; and the size and 
 situation of the heart, stomach, &c. may thus be 
 readily determined. This remarkably fine crab 
 
 * Nummulites Mantellii of Dr. Morton. See Synopsis of the 
 Organic Remains of the Cretaceous Group of North America. 
 8vo, with numerous plates. Philadelphia. 
 
32. FOSSIL CRAB. 237 
 
 (Tab. 41) is from Malta; it shows the state of 
 
 perfection in which fossil Crustacea are sometimes 
 discovered. 
 
 TAB. 41. FOSSIL CRAB, FROM MALTA.* 
 (Cancer Macrochelus.) 
 
 Seven or eight species of fishes, of extinct genera, 
 have been found in the Paris basin alone. The 
 teeth of several kinds of sharks (lamnd) occur everv 
 where, and are known by the name of " birds' bills." 
 In the clay of Sheppey and London, beautiful fossil 
 fishes have been found, the scales possessing a 
 metallic lustre, from an impregnation of sulphuret 
 of iron. But I must pass cursorily over these re- 
 mains, as well as those of crocodiles, turtles, and 
 tortoises, which are imbedded in these deposits. 
 
 32. FOSSIL BIRDS. In the gypseous building- 
 stone of Montmartre, M. Cuvier found many bones 
 which possessed characters peculiar to those of 
 * One half the size of the original. 
 
238 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. III. 
 
 birds ; and after much research he was enabled to 
 determine several fossil species, related to the peli- 
 can, sea-lark, curlew, woodcock, buzzard, owl, and 
 quail. In some examples there are indications of 
 the feathers, and even of the air-tubes. Sometimes 
 the skeleton is wanting, and a pellicle of a dark 
 brown substance alone points out the configuration 
 of the original (Tab. 42). 
 
 Not only are the skeletons and feathers of birds 
 found in the tertiary strata, but even the eggs of 
 
 TAB. 42. FOSSIL BIRD, FROM MONTMARTRE. 
 
 aquatic species occur in the lacustrine limestone of 
 Auvergne. I have already noticed that eggs of 
 
33. FOSSIL ANIMALS OF PARIS. 239 
 
 turtles are daily in the course of fossilization on the 
 shores of the Isle of Ascension. 
 
 33. FOSSIL ANIMALS OF PARIS. We have 
 next to consider the fossil remains of the mammalia 
 whose skeletons were entombed in the mud of the 
 waters which formerly occupied the area of Paris, 
 and which the genius of Cuvier has again, as it were, 
 called into existence. The forms of these extinct 
 creatures are now as familiar to us as our domestic 
 animals, and even the names of palaotheria and 
 anoplotheria are almost become household words. 
 The gypsum quarries which are spread over the 
 flanks of Montmartre have long been known to afford 
 fossil bones ; but, although specimens occasionally 
 attracted the notice of the naturalists of Paris, and 
 collections were formed, yet no one appears to have 
 suspected the mine of wonders which the rocks con- 
 tained, till the curiosity of Cuvier was awakened by 
 the inspection of a large collection of these bones, 
 after he had successfully applied the laws of com- 
 parative anatomy to the investigation of the fossil 
 elephants and mammoths. He had previously paid 
 little or no attention to the partial accounts of fossil 
 bones found in the vicinity of Paris, although in 
 1768, Guettard had figured and described many 
 bones and teeth. Cuvier now, however, perceived 
 that a new world was open to his researches, and he 
 soon, by zeal and energy, obtained an extensive coU 
 lection, and found himself (to use his own expres- 
 sion) in a charnel-house, surrounded by a confused 
 
240 THE WONDERS OF GEOLOGY. LECT. III. 
 
 mass of broken skeletons of a great variety of ani- 
 mals. To arrange each fragment in its proper 
 place, and to restore order to these heaps of ruins, 
 seemed at first a hopeless task ; but a knowledge of 
 the immutable laws by which the organization of 
 animal existence is governed, soon enabled him to 
 assign to each bone, and even fragment of bone, its 
 proper place in the skeleton ; and the forms of beings 
 hitherto unseen by mortal eye arose before him* 
 " I cannot," says this illustrious philosopher, in all 
 the enthusiasm of successful genius, " express mv 
 delight on finding how the application of one prin- 
 ciple was instantly followed by the most trium- 
 phant results. The essential character of a tooth, 
 and its relation to the skull, being determined, im- 
 mediately all the other elements of the fabric fell 
 into their places ; and the vertebrae, ribs, bones of 
 the legs, thighs, and feet, seemed to arrange them- 
 selves even without my bidding, and precisely in 
 the manner which I had predicted." The prin- 
 ciples of comparative anatomy enunciated in the 
 second lecture will have prepared you for this re- 
 sult ; and I therefore need not dwell on the appli- 
 cation of the laws of co-relation of structure by 
 which the animals of the Paris basin have been 
 restored. This group of figures, (Tab. 4-3) from 
 Cuvier's restorations, is indeed a splendid triumph 
 of Palaeontology. 
 
 The examination of the fossil teeth at once showed 
 that the animals were herbivorous, the enamel and 
 
 
33. 
 
 FOSSIL ANIMALS OF PARIS. 
 
 241 
 
 ivory being disposed in the manner already ex- 
 plained (page 132); the crown of the tooth is com- 
 posed of two or three simple crescents, as in certain 
 
 TAB. 43. ANIMALS OF THE TERTIARY EPOCH. 
 
 Fig. 1. Anoplotherium gracile. 2. Palaeotherium magnum. 3. P. minus. 
 4. Anoplotherium commune. 
 
 pachydermata ; thus differing from the ruminants, 
 which have double crescents, and each four lines of 
 enamel. Following out the inquiry, Cuvier at length 
 established that the great proportion of bones and 
 teeth belonged to two extinct genera of pachyder- 
 mata, which bear an affinity to the tapir, rhinoceros, 
 and hippopotamus. Almost every one is familiar 
 with the form and habits of the two last animals ; 
 but the tapir is not so well known. Of this genus 
 there are several living species, all natives of tropi- 
 cal climes. The Malay tapir (a stuffed specimen 
 of which is placed on the lobby of the British 
 
242 THE WONDERS OF GEOLOGY. LECT. III. 
 
 Museum,) sometimes attains eight feet in length, 
 and six in circumference. It has a flexible pro- 
 boscis, a few inches long ; its general appearance 
 is heavy and massive, resembling that of the hog. 
 The eyes are small, the ears roundish ; the skin is 
 thick and firm, and covered with stout hair; the 
 tail short. It inhabits the banks of lakes and rivers, 
 and has been observed to walk under water, but 
 never to swim.* 
 
 34. PALJEOTHERIA, AND ANOPLOTHERIA. 
 These fossil animals are divided into the genera 
 palseotherium (ancient wild beast] ; and anoplo- 
 therium (unarmed wild beast), so named from the 
 absence of canine teeth. I will now describe the 
 species here figured. 
 
 PALJEOTHERIUM MAGNUM, fig. 2. This animal 
 was of the size of a horse, but more thick and 
 clumsy ; it had a massive head, and short extremi- 
 ties. It was like a large tapir, but with differences 
 in the teeth, and a toe less on the fore feet. It must 
 have been from four to five feet in height, which 
 is about equal to that of the rhinoceros of Java. 
 From the conformation of the nasal bones, no doubt 
 can exist of its having been furnished with a short 
 proboscis, or trunk. 
 
 PAL^OTHERIUM MINUS, fig. 3. Of the size of 
 the roebuck. This creature had light and slender 
 limbs, with the general configuration of the tapir. 
 
 ANOPLOTHERIUM GRACILE, fig. 1. This animal, 
 * Griffiths' Animal Kingdom, vol. iii. p. 434. 
 
34. PAL^EOTHERIA AND ANOPLOTHERIA. 243 
 
 to which Cuvier gave the narae of gracile, from 
 its elegant proportions, was of the size and form of 
 a gazelle, and must have lived after the manner of 
 the deer and antelopes. 
 
 ANOPLOTHERIUM COMMUNE, fig. 4 ; was of the 
 height of a wild boar, but of a more elongated 
 form, and had a long and thick tail like a kangaroo, 
 the feet having two large toes like the ruminants. 
 It seems probable that it could swim with facility, 
 and frequented the lakes, in the beds of which its 
 bones were deposited. 
 
 More than fifty genera of extinct mammalia have 
 been discovered in the older tertiary, and their cha- 
 racters determined by Baron Cuvier. Some are 
 related to the animals we have just described ; as 
 the anthracotherium, (so named from the discovery 
 of its remains in the anthracite, or lignite of Cadi- 
 bona,) which held an intermediate place between 
 the hog and hippopotamus. Six or seven species 
 of carnivora, an opossum, a squirrel, dormouse, &c. 
 have also been found in the Paris basin. 
 
 In the miocene strata of Touraine and of Darm- 
 stadt, there is an intermixture of the remains of the 
 above extinct mammalia with those of the mastodon, 
 and of genera which still exist. Mr. Murchison has 
 discovered in Bavaria, bones of the palseotherium, 
 anoplotherium, anthracotherium, mastodon, rhino- 
 ceros, hippopotamus, ox, horse, bear, &c. in lacus- 
 trine deposits, associated with fresh-water and land 
 shells. 
 
 R 2 
 
244 THE WONDERS OF GEOLOGY. LECT. III. 
 35. FOSSIL QUADRUMANA OR MONKEYS. At 
 
 Sausan, in the department of Gers, are tertiary 
 strata, abounding in remains of the rhinoceros, 
 horse, palaeotherium, anoplotherium, and other 
 mammalia. M. Lastel has discovered a jaw of a 
 monkey, which, from its proportions, must have be- 
 longed to an animal about three feet in height. The 
 molar teeth in the specimen are worn, and very 
 closely resemble those of a man of middle age, 
 reduced to half their natural size. Another fossil 
 monkey has been found in the Sub-Himalaya hills 
 near the Sutlej, by Captain Cautly, associated with 
 remains of mastodons, elephants, crocodiles, turtles, 
 &c. This specimen is the right half of the upper 
 jaw, to which a portion of the orbit of the eye re- 
 mains attached, and this alone is sufficient to enable 
 an anatomist to determine the nature of the ori- 
 ginal, the orbits of the quadrumana being peculiar. 
 Without entering upon details uninteresting to the 
 general inquirer, it may be stated that evidence is 
 thus afforded of the existence of a gigantic species 
 of monkey, contemporaneously with the pachy- 
 dermata whose fossil remains occur in the Sub- 
 Himalayas. The important fact is therefore now 
 established, that animals of that type of organization 
 which most nearly resembles the human, existed in 
 the ancient tertiary epochs.* 
 
 * THE QUADRUMANA. These animals come nearest to man 
 in the form and proportion of their skeleton, and of their sepa- 
 rate bones ; in the general disposition of their muscular system, 
 
 
36. TERTIARY STRATA OF AIX, IN PROVENCE. 245 
 
 36. TERTIARY STRATA OF AIX, IN PROVENCE. 
 (See PI. 9, section iii.) A group of tertiary strata, 
 remarkable as well for their mineralogical character 
 as for the organic remains which they contain, 
 occurs near Aix, a town in Provence, which is situ- 
 ated upon a thick deposit of tertiary conglomerate. 
 The series on the northern side of the valley con- 
 sists of 1. Tertiary breccia, (see PI. 9, fig. 3,) 
 lying unconformably on the secondary rocks of 
 oolite and green sand, which are nearly vertical. 
 2. Marl, with fishes and insects. 3. Gypsum and 
 gypseous marls, with fishes and insects ; leaves of 
 
 and its adaptation for a semi-erect position of the body ; in 
 their great cerebral organization, the perfection and equable 
 development of their senses ; their intellectual capacity, and 
 complicated instincts. These most elevated of all inferior 
 animals are fitted to select, obtain, and digest the succulent 
 ripe fruits of trees, and are destined to inhabit the rich and 
 shady forests of tropical climates. They leave to the squirrels 
 and the sloths the buds and leaves ; to the ponderous elephant 
 and rhinoceros the branches and the stems ; and to the beavers, 
 and other rodentia, the dark bark of the trees. Their delicate 
 organization is adapted only for the richest products of the 
 vegetable kingdom ; and the soft and nutritious quality of their 
 food is suitable to the broad enamelled crowns of their molar 
 teeth, which are studded with rounded tubercles : their stomach 
 is simple. With a high cerebral and muscular development, 
 corresponding with their elevated rank in the scale of beings, 
 and the position of their food, they are the most agile and sportive 
 of all mammalia ; and they are provided with prehensile organs 
 at every point ; their teeth, tail, feet, and hands assist in their 
 agile movements, and in their boundings from branch to branch, 
 and from tree to tree. Dr. Grant's Lectures on Comparative 
 Anatomy* 
 
246 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. III. 
 
 palms, and other plants ; fresh-water univalve and 
 bivalve shells, particularly a species of cyclas in 
 great abundance. The cyclas inhabits lakes and 
 marshes, and therefore positively denotes the lacus- 
 trine character of the deposits. 4. Fresh-water 
 limestone. To the south, extending towards Tou- 
 lon, are lacustrine strata of red marl, with compact 
 limestone inclosing shells, gyrogonites, &c. Still 
 farther to the south, beds of grey fresh-water lime- 
 stone appear ; and at Fuveau, (see the section, 
 PI. 9, fig. 3,) a series of blue limestone, shale, and 
 coal, which is extensively worked. Fresh-water 
 
 TAB. 44. FOSSIL FISH, FROM Aix. 
 
 (Smerdis minutus.) 
 (Drawn by Miss Jane Allnutt.) 
 
 shells, seed vessels of charce, and other vegetable 
 remains, occur in abundance in the coal-beds and 
 intermediate layers of shale. The section employed 
 
37. FOSSIL INSECTS. 247 
 
 to illustrate this description is copied from a rough 
 sketch made by Mr. Lyell on the spot, when he first 
 visited this interesting locality ; and which I greatly 
 value on that account. 
 
 The marls, as you may perceive, in this extensive 
 suite of specimens, collected by Messrs. Lyell and 
 Murchison, (whose admirable Memoir* on these 
 strata is of high interest,) are very finely laminated, 
 and contain insects and fishes in a remarkable state 
 of preservation. The fishes are very numerous; 
 one small species in particular (smerdis minutus^ 
 Tab. 44-,) is found grouped together in every va- 
 riety of form and position. 
 
 37. FOSSIL INSECTS. But the fossil insects are 
 the most extraordinary relics, appearing as fresh as 
 if enveloped but yesterday. This beautiful example, 
 presented to me by Mrs. Murchison, shows the ex- 
 quisite preservation of these delicate objects. A 
 few of the most interesting forms are here delineated 
 on a slightly enlarged scale, from the plate accom- 
 panying the paper to which I have referred. -f 
 
 All the insects belong to existing genera, and 
 only one species is aquatic. J The anterior tarsi 
 are generally obscure, or distorted; but in some 
 specimens the claws are visible, and the sculp- 
 ture, and even a degree of local colouring are 
 
 * On the Freshwater Formation of Aix, in Provence, by 
 C. Lyell, and R. I. Murchison, Esqrs. 
 
 t Jameson's Edinburgh Journal, for 1829. PI. VI. 
 \ Principles of Geology, vol. iii. p. 211. 
 
248 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. III. 
 
 preserved. The nerves of the wings in the diptera, 
 and even the pubescence on the head, are distinctly 
 seen. Several of the beetles have the wings ex- 
 
 TAB. 45. FOSSIL INSECTS FROM Aix, IN PROVENCE. 
 
 Fig. 1. Tettigonia spumaria. 2. Mycetophila, imbedded while in the 
 act of walking ; the articulations of the body distended by pressure. 
 3. Lathrobium. 4. Allied to Penthetria holosericea. The hinder legs 
 are broken off, and one of them is reversed, so that the tarsi nearly 
 touch the thigh ; the palpi are long and perfect ; the antennce remark- 
 ably distinct. 5. Liparus, resembling L. punctatus. 
 
 tended beyond the elytra) as if they had fallen into 
 the water while on the wing, and had made an 
 effort to escape by flight. M. Marcel de Serres 
 has enumerated nearly seventy genera of insects, 
 
37. FOSSIL INSECTS. 249 
 
 and a few arac/mides, or spiders. The most curious 
 fact is, that some of the insects are identical with 
 species which now inhabit Provence. It seems pro- 
 bable that these insects were brought together from 
 different localities by floods, and mountain streams ; 
 yet, as Mr. Curtis observes, all of them might have 
 inhabited moist and shady forests. The laminated 
 marls contain also the coverings of a fresh-water 
 Crustacea, called cypris, which swarms in our pools 
 and stagnant waters, and must be familiar to all 
 who have seen the exhibition of the oxy-hydrogen 
 microscope ; living specimens being commonly 
 shown, and appearing somewhat like the head and 
 feet of a flea protruding from an oval case or 
 shield, and swimming by means of their fine cilia, 
 which resemble pencils of hair. These Crustacea 
 shed their cases, some of which are silicious and 
 others calcareous, annually, and the surface of the 
 mud spread over the bottoms of lakes is often 
 strewed with their relics. The marls of Aix, as 
 well as of many other fresh-water formations, abound 
 in fossil cyprides, which sometimes constitute entire 
 seams or laminae, that alternate with the marl. The 
 seed-vessels of the chara, a common plant in our 
 ditches and ponds, also occur in profusion ; they 
 were formerly supposed to be shells, and from their 
 peculiar structure received the name of gyrogonites, 
 which they still bear, although their real nature 
 has long since been ascertained.* In conclusion, 
 
 See an Essay on the fresh-water marls of Scotland, by 
 Mr. Lyell. 
 
250 THE WONDERS OF GEOLOGY. LECT. III. 
 
 Mr. Lyell observes, " that this tertiary series differs 
 essentially from that of the London and Paris 
 basins. The great development of regular beds 
 of blue limestone and shale, the quality and ap- 
 pearance of the coal, and the thickness of the 
 compact grey, brown, and black argillaceous lime- 
 stones and sandstones, give them the aspect of the 
 most ancient of our secondary rocks ; and it is 
 only by the peculiar species of fluviatile and lacus- 
 trine shells, the seed-vessels of the charse, c. that 
 the comparatively recent date of the whole group 
 is demonstrated." 
 
 38. LACUSTRINE FORMATION OF (ENINGEN. 
 Among the tertiary lacustrine formations on the 
 continent, there is one so much celebrated for its 
 organic remains, that I will offer a few remarks on its 
 peculiar characters. CEningen, near Constance, has 
 for centuries been known to contain fossil remains 
 of great beauty and interest. A short, but graphic, 
 memoir by Mr. Murchison,* presents in a few pages 
 the history of this ancient lake. The Rhine, in 
 its course from Constance to Schaffhausen, flows 
 through a depression of the tertiary marine forma- 
 tion, known by the name of Molasse, which forms 
 hills on both sides of the river, of from 700 to 900 
 feet in height. In a depression or basin of this 
 molasse, is a series of strata composed of marls, 
 and cream-coloured, fine-grained, fetid limestone, 
 with laminated white marl-stone, forming a total 
 
 * On a fossil Fox found at CEningen, by R. I. Murchison, 
 Esq., Pres. G.S. &c. Geological Transactions, 1832. 
 
39. FOSSIL FISHES OF MONTE BOLCA. 251 
 
 thickness of thirty or forty feet. In the marl-stone, 
 leaves and stems of plants, insects, shells, Crustacea, 
 fishes, turtles, a large aquatic salamander, birds, and 
 a perfect skeleton of a fox, have been discovered. 
 The fox was obtained by Mr. Murchison, for whom 
 I developed it, and removed the stone so as to 
 expose the entire skeleton : this extraordinary fossil, 
 which does not differ in its osteology from the recent 
 species, is figured and described in the Geological 
 Transactions for 1832. A tortoise, 'three feet in 
 length, with the head, neck, tail, and three of the 
 paws, well preserved, has since been discovered. 
 Mr. Murchison concludes that these fresh- water de- 
 posits are the contents of a lake, belonging to the 
 newer pliocene epoch, but that the period of their 
 formation must have long preceded the present 
 condition of the country, the Rhine having subse- 
 quently worn a channel through them to the depth 
 of several hundred feet. 
 
 39. FOSSIL FISHES OF MONTE BOLCA. I will 
 here notice another interesting assemblage of ter- 
 tiary strata the celebrated ichthyolite quarries of 
 Monte Bolca and then proceed to the consider- 
 ation of the effects of volcanic action during the 
 geological epochs embraced in this discourse. 
 Monte Bolca is situated on the borders of the 
 Veronese territory, about fifty miles NN.W. of the 
 lagunes of Venice, and forms part of a range of hills 
 of moderate elevation ; volcanic deposits abound in 
 the neighbouring Vicentin, and the summit of the 
 
252 THE WONDERS OF GEOLOGY. LECT. III. 
 
 hill is capped with basalt.* It is principally com- 
 posed of argillaceous and calcareous strata, with 
 beds of a cream-coloured fissile limestone, which 
 readily separates into laminae of moderate thickness, 
 and abounds in fishes in the most beautiful state of 
 preservation. They are all compressed flat, but the 
 scales, bones, and fins remain ; their colour is a 
 deep brown, thus admirably contrasting with the 
 limestone in which they are imbedded. Several 
 hundred distinct species are supposed to be con- 
 tained in these quarries, and thousands of specimens 
 have been collected ; according to M. Agassiz, all 
 the species, though related to the recent, are extinct. 
 From the immense quantities which occur in so 
 limited an area, it seems probable that the limestone 
 in which they are imbedded was erupted into the 
 ocean in a fluid state by volcanic agency ; and that 
 the fishes were thus suffocated, and surrounded by 
 the calcareous mass. Nor is this hypothesis without 
 support, for on the appearance of a volcanic island 
 in the Mediterranean, a few years since, hundreds 
 of dead fishes were seen putrid and floating in the 
 waters ; and it cannot be doubted that shoals of 
 fishes might at the same time have been enveloped 
 in the volcanic matter at the bottom of the sea, and 
 become compressed and preserved ; when the mud 
 which envelopes them is consolidated, and the bed 
 of the Mediterranean elevated above the waters, 
 
 * Organic Remains of a Former World, vol. iii. p. 247. 
 
40. TERTIARY VOLCANOES OF FRANCE. 253 
 
 these fishes may resemble the ichthyolites of Monte 
 Bolca.* 
 
 40. TERTIARY VOLCANOES OF FRANCE. In the 
 former lecture I alluded to volcanic action as being 
 still in activity, and as having taken place in more 
 ancient periods ; and we have abundant proof that 
 during the immense lapse of time comprehended 
 between the earliest and the latest of the tertiary 
 formations, the internal fires of our globe were not 
 dormant. I have already had occasion to observe, 
 how rarely the former geographical relations of a 
 country are preserved, and that although we may 
 be able to pronounce with certainty that this spot 
 was once dry land, that there flowed a river, 
 that here is the bed of an ancient sea yet we can 
 seldom ascribe limits to the one, or trace the boun- 
 daries of the other. But there is one remarkable 
 exception a district, where the most important 
 and striking geological mutations have taken place, 
 and yet the area of those changes still preserves its 
 ancient physical geography that district is Au- 
 vergne, a province in central France. 
 
 Nearly a century since, two French academicians, 
 MM. Guettard and Malesherbes, on their return 
 from an exploration of Vesuvius, arrived at Monte- 
 limart, a small town on the left banks of the Rhone, 
 where Faujas St. Fond, a distinguished naturalist, 
 was sojourning. These savans were struck with 
 
 * See Lecture VIII. 
 
254 THE WONDERS OF GEOLOGY. LECT. III. 
 
 the pavements of the streets, which were formed of 
 shore joints of basaltic columns, placed perpendicu- 
 larly in the ground ; and upon inquiry they found, 
 that the stones were brought from the neighbouring 
 mountains of the Vivarais. This information induced 
 them to survey the country ; and upon arriving at 
 Clermont, a town with about 30,000 inhabitants, 
 the capital of Auvergne, they were satisfied that the 
 whole region was of volcanic origin ; for in the 
 vicinity of the town they discovered currents of 
 lava, black and rugged as those of Italy, descending 
 uninterruptedly from some conical hills of scoriae, 
 which still preserved the form of craters. " To 
 those who now visit central France, and see on 
 all sides the most unequivocal marks of volcanic 
 agency the numerous hills formed entirely of 
 loose cinders, and porous and diversified as if just 
 thrown from a furnace, surrounded by plains of 
 black rugged lava, on which even the lichen almost 
 refuses to vegetate, it appears scarcely credible, 
 that previous to the last half century, no one had 
 thought of attributing these marks of desolation to 
 the only powers in nature capable of producing 
 them. This, however, is perfectly natural, and 
 not without examples. The inhabitants of Hercu- 
 laneum and Pompeii built their houses with the 
 lava of Vesuvius, ploughed up its scoriae and ashes, 
 and ascended its crater, without dreaming of their 
 neighbourhood to a volcano which was to give the 
 first proof of its energies by burying them beneath 
 
41. EXTINCT VOLCANOES OF AUVERGNE. 255 
 
 its eruptions, The Catanians regarded as a fable 
 all mention of the former activity of Etna, when, 
 in 1669, half their town was overwhelmed by its 
 lava currents."* 
 
 41. EXTINCT VOLCANOES OF AUVERGNE. The 
 country which is the site of the extinct volcanoes to 
 which I am about to call your attention, may be 
 described as a vast plain, situated in the department 
 of the Limagne d'Auvergne : it is so remarkable 
 for its fertility, that it is called the Garden of 
 France ; a quality attributable to the detritus of 
 volcanic rocks, which enters into the composition 
 of the soil. It is inclosed on the east and west by 
 two parallel ranges of gneiss and granite. Its 
 average breadth is twenty miles, its length between 
 forty and fifty, and its altitude about 1,200 feet 
 above the level of the sea. The surface of this 
 plain is formed of alluvial deposits, composed of 
 granitic and basaltic pebbles, and boulders, reposing 
 on a substratum of limestone. Hills, of various 
 elevations, composed of calcareous rocks, are scat- 
 tered over the plain; and the river Allier flows 
 through the district, over beds of limestone or sand- 
 stone, except where it has excavated a channel to 
 
 Geology of Central France, by G. Poulett Scrope, Esq. 
 F.R.S., 1827. Mr. Bakewell was the first English geologist 
 who directed attention to this remarkable district; (Travels in 
 the Tarentaise, by Robert Bakewell, Esq. 2 vols. 8vo. 1823 ;) 
 subsequently Dr. Daubeny, Messrs. Scrope, Lyell, and Mur- 
 chison, have severally published highly interesting treatises on 
 the subject. 
 
256 THE WONDERS OF GEOLOGY. LECT. III. 
 
 the foundation-rock of granite. The hills composed 
 of calcareous alluvial deposits are the remains of a 
 series of beds, which once constituted an ancient 
 plain, at a higher elevation than the present. Many 
 are surmounted by a crest or capping of basalt, to 
 which their preservation is probably attributable ; 
 others have escaped destruction from being pro- 
 tected by horizontal layers of a durable limestone, 
 which I shall presently describe. We have, then, 
 as the ground plan of the district, an extensive 
 plain, chequered with low hills of fresh- water 
 limestone, which are capped with compact lava 
 (Plate VIII. figs. in. iv.) ; the boundaries of the 
 plain being formed of ranges of primary rocks, 
 3,000 feet in altitude. To the westward the lime- 
 stone disappears, and a plateau of granite rises 
 to a height of about 1,600 feet above the valley 
 of Clermont, being 3,000 feet above the level of 
 the sea. This supports a chain of volcanic cones 
 and dome - shaped mountains, about seventy in 
 number, varying in altitude from 500 to 1,000 feet 
 from above their bases, and forming an irregular 
 range nearly twenty miles in length, and two in 
 breadth. The highest point of this range is the 
 Puy de Dome, which is 4,000 feet above the 
 level of the sea (Plate VIII. fig. u. 4), and is com- 
 posed entirely of volcanic matter ; it possesses a 
 regular crater, 300 feet deep, and nearly 1,000 
 feet in circumference. Many of these cones retain 
 the form of well-defined craters, and their lava 
 
42. CRATER OF PUY DE COME. 257 
 
 currents may be traced as readily as those of 
 Vesuvius. 
 
 42. CRATER OF PUY DE COME. One of the 
 most remarkable cones is the Puy de Come, which 
 rises from the plain to the height of 900 feet ; 
 its sides are covered with trees, and its summits 
 present two distinct craters, one of which is 250 
 feet in depth. A stream of lava may be seen to have 
 issued out from the base of the mountain, which at 
 a short distance, from having been obstructed by a 
 mass of granite, has separated into two branches ; 
 these can be traced along the granitic platforms, and 
 down the side of a hill into an adjacent valley, where 
 they have dispossessed a river of its bed, and con- 
 strained it to work out a fresh channel between the 
 lava and the granite of the opposite bank. Another 
 cone rises to the height of 1,000 feet above the 
 plain, having a crater nearly 600 feet in vertical 
 depth, and a lava current, which first falls down a 
 steep declivity, and then rolls over the plain in 
 hilly waves of black and scorified rocks. In one 
 part of this volcanic group is a circular system of 
 cones, apparently the produce of several rapidly 
 succeeding eruptions. " The extraordinary cha- 
 racter of this scene impresses it for ever on the 
 memory ; for there is, perhaps, no spot, even among 
 the PhlegraBan fields of Italy, which more strikingly 
 displays the characters of volcanic desolation. Al- 
 though the cones are partially covered with wood 
 and herbage, yet the sides of many are still naked ; 
 s 
 
258 THE WONDERS OF GEOLOGY. LECT. III. 
 
 and the interior of their broken craters, rugged, 
 black, and scorified, as well as the rocky floods of 
 lava with which they have loaded the plain, have a 
 freshness of aspect, such as the products of fire 
 alone could have so long preserved, and offer a 
 striking picture of the operation of this element in 
 all its most terrible energy."* A description of 
 the accompanying sketches-)- will serve to illustrate 
 these remarks. 
 
 Plate VIII. fig. in. The environs of Clermont. 
 The town is seen on the plain or basin, which has 
 been excavated by diluvial agency, since the de- 
 position of the strata which form the surrounding 
 hills. In front is a basaltic peak (coloured green), 
 crowned by the Castle of Montrognon ; and beyond 
 are basaltic platforms on hills of limestone. In 
 the distance is the primary escarpment, forming 
 part of the boundary of the volcanic district. 
 
 Plate VIII. fig. ii. Part of the southern volcanic 
 chain of Puys, exhibiting the broken craters of 
 Chaumont; from the bases of several, lava currents 
 are seen to have issued. No. 1, Montchal ; 2, 
 Puys de Montgy ; 3, Monjughat ; 4, Mont Dome 
 in the distance. 
 
 Plate VIII. fig. iv. represents hills of secondary 
 Jura limestone, capped by basalt (coloured green). 
 These crests are the terminations of lava currents, 
 
 * Scrope's Geology of Central France, 
 j- The delineations are reduced from the elaborate and beau- 
 tiful drawings of Mr. Scrope. 
 
43. MONT DOR. 259 
 
 that once extended over the whole area, covering 
 a platform of primary rocks, and flowing on to the 
 secondary strata, which, in this part of Ardeche, 
 constitute an elevated limestone district. 
 
 This region affords a striking illustration of 
 the erosion of the surface of a country by alluvial 
 action. The thickness of the volcanic mass is be- 
 tween 300 and 400 feet; it is composed of two 
 distinct beds of basalt, separated by a layer of 
 scoriae and volcanic fragments. Many portions, 
 both of the upper and lower beds, are made up of 
 well-defined, vertical, polygonal columns. The 
 streams of lava to which these plateaux belong, 
 have been traced for more than thirty miles ; they 
 rise in a narrow ridge across the primitive heights, 
 and then spread over, and lie conformably upon, 
 the secondary formations. The limestone beneath 
 the basalt is, in some places, covered with vegetable 
 soil, containing a common species of terrestrial 
 shell ( Cyclostoma elegans). The nearly horizontal 
 disposition of the basalt, its columnar structure, 
 artd position on the limestone, into which it has 
 injected veins and dikes, render it, as Mr. Scrope 
 observes, very analogous to the ancient volcanic 
 rocks of Ireland, which will be described in a future 
 lecture. 
 
 43. MONT DOR. Before entering upon the de- 
 scription of the organic remains found in the rocks 
 and strata we have thus hastily surveyed, it will 
 be necessary to notice another system of extinct 
 s2 
 
260 THE WONDERS OF GEOLOGY. LECT. III. 
 
 volcanoes, situated in the same province, and con- 
 nected with the Puy de Dome. While in the dis- 
 trict I have just described, the primitive soil is 
 only partially obscured by the volcanic products, in 
 Mont Dor, the granitic foundation is covered over 
 an area of many miles in extent, and the erupted 
 masses attain a considerable elevation. Mont Dor 
 is a mountainous tract, the highest portion of which 
 is about 6,000 feet in altitude. It consists of a 
 group of seven or eight rocky summits, which form 
 a zone a mile in diameter, the whole consisting 
 of a succession of beds of volcanic origin. It is 
 deeply channelled by two principal valleys, and 
 furrowed by many minor water-courses, all origi- 
 nating near the central eminence, and diverging 
 towards every point of the horizon. The beds of 
 which this group is composed, consist of scoriae, 
 pumice-stone, trachyte, and basalt ; these rocks 
 dip off from the central axis, and lie parallel 
 to the sloping flanks of the mountain, as is the 
 case in Etna, the Peak of Teneriffe, and all other 
 insulated volcanic mountains (see the section of a 
 volcano, Plate VIII. fig. 1). There is no crater, 
 all vestiges having been destroyed since the ex- 
 tinction of its fires ; but streams of lava may be 
 traced in elevated peaks, over a gorge which oc- 
 cupies the very heart of the mountain, and they 
 extend to a distance of many miles. A remarkable 
 natural section, worn by a cascade, at a short dis- 
 tance from the baths of Mont Dor, exhibits the 
 
44. FRESH- WATER LIMESTONE. 261 
 
 general structure of the beds (PI. VIII. fig. 5). 
 They consist in a descending series of 1. Porphy- 
 ritic trachyte ; a volcanic rock, 160 feet tn thick- 
 ness. 2. Arenaceous tufa. 3. Columnar basalt. 
 4. Breccia, made up of volcanic fragments, cemented 
 together by tufa. 5. Thick beds of basalt. 6. 
 White ferruginous tufa, enveloping fragments of 
 granite, basalt, &c. This bed is traversed by veins 
 of the overlying basalt. 
 
 I may add, that the volcanic vents of central 
 France are evidently of very different ages ; some 
 being of immense antiquity, while others must be 
 of comparatively recent origin, for they have ex- 
 ploded through the older beds of basalt. 
 
 44. FRESH-WATER LIMESTONE, AND ORGANIC 
 REMAINS OF AuvERGNE. The volcanic rocks of 
 this district present alternations of limestone, 
 abounding in fresh-water shells and other animal 
 remains ; with basalt, scoriae, and other igneous 
 productions, based on a foundation of granite. 
 These beds are arranged in the following order, 
 beginning with the lowest or most ancient : 
 
 1st. Clay, sand, and breccia, without organic 
 remains. 
 
 2d. Limestone and calcareous marl, in strata 
 nearly horizontal ; about 900 feet thick. These are 
 entirely of fresh-water origin, and abound in shells 
 of the genera potamides, helix, planorbis, and lym- 
 nea, which are known to inhabit lakes and rivers. 
 Some of the beds contain bitumen ; others are 
 
262 THE WONDERS OF GEOLOGY. LECT. III. 
 
 entirely made up of the cases of the caddis-worm 
 (Indusia tubulata), cemented together by calcareo- 
 silicious matter. This specimen, which was in the 
 cabinet of Faujas St. Fond, displays the characters 
 of this remarkable concrete : it consists of the tubes 
 or cases of the larva of a species of phryganea ; 
 similar remains have been mentioned as occurring 
 in abundance in the alluvial silt of Lewes Levels 
 (page 45). The tubes are formed by the adhesion 
 of shells to the outer surface of the silken case 
 secreted by the insect ; these cases are abandoned 
 by the animal when its metamorphosis is completed, 
 and groups of them may be seen in ditches or lakes. 
 In the fossil they have been cemented by calcareous 
 infiltration into a stone, so hard as to be employed 
 for building. The attached shells are so minute, 
 that more than a hundred are affixed to one tube, 
 and the space of a cubic inch often includes ten or 
 twelve tubes. If, says Mr. Scrope, we consider 
 that repeated strata, of five or six feet in thickness, 
 almost entirely composed of these tubes, once ex- 
 tended over the whole plain of the Limagne, occu- 
 pying a surface of many hundred square miles, we 
 may have some idea of the countless myriads of 
 minute beings which lived and died within the 
 bosom of that ancient lake. In the limestone, 
 associated with land and fresh-water shells, and 
 remains of vegetables, are bones of the palaeothe- 
 rium, anoplotherium, lagomys, martin, dog, rat, 
 tortoise, crocodile, serpent, and birds, and in which 
 
44. LIMESTONE OF AUVERGNE. 2G3 
 
 the lava currents that have flowed over them have 
 produced but little change. This series comprises 
 also beds of gypseous and laminated marls, with 
 intercalations of silicious limestone, containing im- 
 pressions of lake and river shells. In some loca- 
 lities, the fresh-water limestone has an intermixture 
 of volcanic matter, presenting all the characters of 
 a sediment slowly and tranquilly deposited in a 
 lake, into which ashes, and fragments of rocks and 
 scoria?, were projected by a neighbouring volcano ; 
 while there are beds which appear to have been 
 formed by a violent intrusion of volcanic matter. 
 
 3d. Immense beds of volcanic production, con- 
 sisting of basalt, scoriae, &c. now existing in sheets 
 of lava, either spread over the tabular masses of 
 fresh-water limestone, or appearing as crests on the 
 summits of the lower hills. (Plate VIII. fig. 3.) 
 
 4th. Sand and diluvial gravel, containing bones 
 of the mastodon, elephant, hippopotamus, rhino- 
 ceros, tapir, horse, boar, felis, hyena, bear, dog, 
 beaver, hare, &c. ; with these are associated lignite, 
 and other vegetable remains. Some of the beds of 
 limestone abound in seed-vessels of the chara ; 
 and the laminated clays contain fishes, and leaves, 
 stems, &c. of reeds and other plants. 
 
 There are several in crusting springs in Auvergne, 
 largely impregnated with carbonic acid, which pour 
 out immense quantities of calcareous tufa ; these 
 burst through the primary rocks, which form the 
 base of the whole territory, and cover the volcanic 
 
261 THE WONDERS OF GEOLOGY. LECT. III. 
 
 focus whence these mineral waters, in all probability, 
 originate. Thermal springs are also very numerous 
 throughout this district. 
 
 45. SUMMARY OF THE GEOLOGICAL PHENO- 
 MENA OF AUVERGNE. In the calcareous and sili- 
 cious limestones of Auvergne, and their associated 
 laminated marls, gypsum, lignite, and conglomerate, 
 we have a general analogy with the older fresh- 
 water tertiary formations of Paris and the Isle of 
 Wight ; the shells and plants being similar, and the 
 quadrupeds of the same genera. And if we suppose 
 the Paris basin to have been elevated during the 
 active state of neighbouring volcanoes, and that 
 successive streams of lava had flowed over its 
 sedimentary deposits, we should have a series of 
 phenomena resembling those of Auvergne, with the 
 exception that the presence of marine remains would 
 denote that the basin had been filled with salt water. 
 The facts submitted to our notice appear to establish 
 the following sequence of physical events. 
 
 1st. The elevation, after the deposition of the 
 secondary limestone, of the whole area of the pri- 
 mary rocks which form the foundation of central 
 France. 
 
 2dly. A period of tranquillity, during which fresh- 
 water lakes occupied the irregular hollows of the 
 district ; the neighbouring country being inhabited 
 by palseotheria, anoplotheria, and other extinct 
 mammalia, whose bones, together with the then 
 existing vegetation, and the shells of the lacustrine 
 
45. GEOLOGICAL PHENOMENA OF AUVERGNE. 265 
 
 mollusca, were enveloped in the tranquil depositions 
 going on in the lacustrine basins. 
 
 Sdly. Another elevation of the district ; a new 
 system of lakes was established, the country became 
 clothed with forests, and inhabited by large deer, 
 oxen, rhinoceroses, and hyenas, whose skeletons 
 were imbedded in the sediments of the waters. 
 
 4thly. The volcanoes became active ; explosions 
 took place through hundreds of vents ; trachyte and 
 basalt were ejected, and in some places pierced the 
 fresh-water deposits, while in others they overspread 
 them with sheets of lava. Vegetation still flourished, 
 and the remains of plants were entombed in the 
 volcanic products. 
 
 5thly. Another period of tranquillity the rivers, 
 and other water-courses, dammed up, or deranged 
 by the lava currents, formed new channels, and ac- 
 cumulated beds of gravel, sand, and clay. Gigantic 
 deer and oxen still inhabited the district, having 
 for contemporaries hyenas and other carnivora. 
 Volcanic eruptions succeeded, and continued till a 
 comparatively recent period. 
 
 Lastly. Floods and rivers of later date, which 
 now constitute the drainage of the country, began 
 to wear away channels through the beds of lava and 
 limestone to the granite rock beneath, intersected 
 the country with valleys and ravines, and spread 
 over the ancient beds the modern alluvial soil.* 
 
 * This account of the volcanic district of Auvergne, is an 
 abstract of the interesting Essays of Messrs. Bakewell, Scrope, 
 
266 THE WONDERS OF GEOLOGY. LECT. III. 
 
 46. EROSION OF VALLEYS BY WATER-CURRENTS. 
 There is perhaps no district which exhibits in 
 more striking characters the erosive power of run- 
 ning water, than Auvergne. In many places the 
 basalt is columnar, like that of Staffa, and the Giants' 
 Causeway ; and one range, on the banks of the 
 Ardeche, forms a majestic colonnade 150 feet in 
 height, extending a mile and a half along the valley 
 which has been channelled out by the stream that 
 flows at its base. Mr. Scrope's description of this 
 process is highly graphic. " The bed of the Ardeche 
 is strewed with basaltic boulders, pebbles, and sand, 
 originating from the destruction of the columnar 
 ranges. In some of the volcanic cones the beds 
 of basalt may be traced issuing from the crater and 
 following the inequalities of the valley, just as a 
 stream of lava would flow down the same course at 
 the present time. Yet these ancient currents have 
 since been corroded by rivers which have worn 
 through a mass of rock 150 feet in height, and 
 formed a channel even in the granite rocks beneath, 
 since the lava first flowed into the valley. In an- 
 other spot, a bed of basalt 160 feet high, has been 
 cut through by a mountain stream, and very beau- 
 tiful columnar masses are displayed. The vast ex- 
 cavations effected by the erosive power of water 
 along the valleys which feed the Ardeche, since 
 
 Lyell, Murchison, Dr. Daubeny, Dr. Hibbert, MM. Croiset, 
 Jobert, Robert, and Bertrand-Roux. Mr. Scrope's work cannot 
 be perused, even by the general reader, without deep interest. 
 
47. EXTINCT VOLCANOES OF THE RHINE. 267 
 
 their invasion by lava currents, prove that even the 
 most recent of these volcanic eruptions belong to 
 an era incalculably remote." 
 
 4-7. EXTINCT VOLCANOES OF THE RHINE. 
 I have dwelt so long on the Phlegraean fields of 
 Auvergne, that but a brief space can be afforded 
 to another group of tertiary volcanoes. Every one 
 who has ascended the Rhine, will remember where 
 
 " The castled crag of Drachenfels 
 Frowns o'er the wide and winding Rhine," 
 
 forming one of the Siebengebirge, or Seven Moun- 
 tains, whose majestic and graceful forms suddenly 
 
 TAB. 46. THE DRACHENFELS. 
 (Drawn by Miss Jane Allnutt.) 
 
 burst on the sight, rising from the level plains on 
 the right bank of the river, to an altitude of nearly 
 
268 THE WONDERS OF GEOLOGY. LECT. III. 
 
 1,500 feet. These picturesque objects belong to 
 a group of extinct volcanoes ; while, on the opposite 
 side of the river, the Eifel, with its crater covered 
 with scoriae and cinders, and lava currents still dis- 
 tinctly visible, attest the wide area over which those 
 ancient fires once extended. Unlike the district 
 we have just noticed, the foundation rock of the 
 country is an ancient sedimentary deposit, called 
 greywacke, consisting of coarse red sandstone and 
 slate of a peculiar character, which we shall describe 
 hereafter, thrown into a highly inclined position. 
 Through these beds the volcanic eruptions, con- 
 sisting of trachyte, basalt, and other modifications 
 of trap rocks and scoriae, have forced their way. 
 The basalt is black, very compact, and breaks into 
 sharp fragments ; it is frequently columnar, and 
 the separate hexagonal pillars are made use of for 
 posts and paving, in the adjacent towns. Such, 
 says Mr. Homer (whose interesting memoir* has 
 furnished the materials for this imperfect sketch), 
 is the profusion of basaltic pillars, that the walls 
 of the town of Linz are wholly built of these mate- 
 rials, placed on their sides, with the ends projecting 
 outwards. The streets are paved with the smaller 
 columns set on end, thus forming a miniature re- 
 presentation of the Giants' Causeway; and the same 
 volcanic product forms a large proportion of the 
 walls of Bonn and Cologne. The greywacke is 
 
 * On the Geology of the Environs of Bonn, by Leonard 
 Homer, Esq. F.R.S. Geological Transactions, vol. iv. 1836. 
 
48. BROWN COAL FORMATION. 269 
 
 covered by a series of tertiary deposits, consisting 
 of sand, sandstone, clay, and lignite, constituting 
 what is termed a brown coal formation. On these 
 strata an extensive layer of gravel is superposed, 
 over which is spread a loosely coherent, sandy loam, 
 provincially termed loess, which contains recent 
 species of terrestrial and fresh-water shells, and 
 forms the subsoil of the vast plains in which Bonn 
 and Coblentz are situated, extending as far as the 
 falls of Schaifhausen. 
 
 4-8. BROWN COAL FORMATION. As the usual 
 condition in which bituminized vegetable matter 
 occurs in the tertiary formations, is well exemplified 
 in the brown coal, or lignite, of the Rhine, it will 
 be instructive to examine the characters of this 
 deposit somewhat in detail; for we shall thereby 
 obtain data which will prepare us for the investi- 
 gation of the ancient carboniferous system. This 
 formation, which is spread over a great extent of 
 country on both sides of the Rhine, consists of 
 clay, sand, sandstone, conglomerates, clay and iron- 
 stone, and lignite, or bituminized wood of various 
 qualities, disposed in distinct beds, and intermixed 
 with argillaceous matter. The breadth of the 
 ridge of low hills formed by this assemblage of 
 strata on the left bank of the Rhine, is from three 
 to five miles, its elevation varying from 50 to 
 200 feet. 
 
 The lignite occurs in the following states: 
 1. A black earthy and pulverulent substance. 2. Con- 
 
270 THE WONDERS OF GEOLOGY. LECT. III. 
 
 cretionary masses, with leaves and fragments of 
 wood. 3. Wood in various degrees of bitumini- 
 zation, and of shades of colour, from a light-brown 
 to jet-black. 4. Very finely laminated masses of 
 bituminous matter and clay, of a dark chocolate 
 colour, and separating into elastic flakes, as thin as 
 paper, whence its name papierkohle. These speci- 
 mens, collected by Sir P. M. de Grey Egerton, Bart, 
 exhibit the peculiar character of the substance, 
 which is so highly bituminous as to burn with a 
 bright flame. The wood is generally in inconsider- 
 able fragments ; but stems of large trees, somewhat 
 compressed, occasionally occur ; in some instances 
 the trees are imbedded in an upright position, with 
 the roots attached and the stems passing through 
 several beds of lignite. In many examples the wood 
 is so little changed, that, like the timber of our 
 peat-bogs, it is employed in building ; in others it 
 is highly pyritous, or in other words, is impregnated 
 with sulphuret of iron, like the fossil vegetables 
 of Sheppey. Mr. Homer states, as the result of his 
 investigations, that there were extensive fresh- water 
 lakes, in the sediments of which trees and plants, 
 drifted by land-floods, were engulfed ; and that vol- 
 canic eruptions were simultaneously going on, in 
 the same manner as in the modern submarine 
 volcanoes. There is a great fault, or dislocation, 
 of the brown coal formation, which may be attri- 
 buted to a powerful and sudden volcanic explosion, 
 that probably occasioned the elevation of the 
 
48. BROWN COAL FORMATION. 271 
 
 Siebengebirge, and raised up that portion of the 
 coal-beds which reposes on the flanks of those 
 peaks. The gravel covering the lignite, must have 
 been strewed over the plain previously to this ele- 
 vation, for it is found on both sides of the river at 
 a great height, and not in the intermediate plain. 
 These inductions are so evident as to require no 
 comment. 
 
 The ancient alluvium, the loess, very much re- 
 sembles a bed of loam which occurs in some parts 
 of Lewes Levels, and incloses fresh-water and land 
 shells of many existing species ; it rarely contains 
 bones of quadrupeds ; a few remains of the horse 
 and mammoth have however been discovered.* 
 From the extensive distribution of this deposit, and 
 its occurrence at various elevations, in some in- 
 stances on the flanks of mountains 1,200 feet above 
 the level of the sea, at others spread out over the 
 gravel of the vast plain of the Rhine, it is inferred, 
 that although the loess has been deposited since 
 the existing system of the hills and valleys of the 
 country, yet that changes must have taken place in 
 the physical geography of the district, subsequent 
 to its original formation ; and there is reason to 
 conclude, that since the deposition of this fluviatile 
 loam all the land between Switzerland and Holland 
 has suffered a subsidence, and a subsequent eleva- 
 tion, to the amount of many hundred feet.f 
 
 * Principles of Geology, vol. iv. p. 33. 
 
 f Ibid. ; read with particular attention, pp. 36 and 37. 
 
272 THE WONDERS OF GEOLOGY. LECT. III. 
 
 49. OTHER TERTIARY STRATA OF EUROPE, 
 NORTH AMERICA, &c. It has already been men- 
 tioned that strata, referable to the period compre- 
 hended between the newest secondary formations 
 and the human epoch, occur throughout Europe, 
 presenting in some instances well-defined groups, 
 with marked boundaries ; in others, vast areas, over 
 which these deposits are irregularly spread. The 
 geographical relations of the tertiary strata to the 
 existing lands and seas, is an interesting subject of 
 inquiry, but one on which my limits forbid me to 
 enter. I may however observe, that Europe must 
 have possessed many of its most striking physical 
 characters at the commencement of the eocene 
 period ; and that its present configuration has been 
 produced by the conjoint effect of successive muta- 
 tions in the relative level of land and water, during 
 the deposition of the marine and fresh- water strata, 
 reviewed in this discourse. In India, formations of 
 a like nature have been observed in the Burmese 
 empire, in the Sub-Himalaya mountains, and in the 
 Caribari hills ; and among the remains of various 
 quadrupeds a new species of anthracotherium, one 
 of the genera discovered in the tertiary strata of 
 France, has been found. 
 
 In North America the researches of Dr. Morton, 
 Professor Vanuxem, and other observers, have 
 shown that in the territories of the United Slates 
 tertiary deposits extend over a great part of Mary- 
 land, along the coast of New York and New 
 
50. TERTIARY STRATA OF THE ANDES. 273 
 
 England, and occur in New Jersey, Delaware, Long 
 Island, &c. The tertiary beds of Maryland consist 
 of limestone, clay, sand, and gravel, and abound 
 in the usual types of European tertiary marine 
 shells. 1 have placed before you an extensive 
 collection from the United States, for which I am 
 indebted to the kindness of Dr. Morton, Mr. Conrad, 
 Professor Silliraan, Dr. Harlan, and other American 
 savans ; and you will observe how striking is the 
 general analogy between these shells and those of 
 the Paris and London basins. The turritella^ vene- 
 ricardia, fusus, ancilla, &c. are identical with the 
 European species ; but some of the types are alto- 
 gether new. 
 
 50. ALTERED TERTIARY STRATA OF THE ANDES. 
 But striking as are the proofs already adduced 
 of elevation, and other effects of volcanic agency 
 during the tertiary period, these sink into com- 
 parative insignificance when contrasted with the 
 enormous changes which have taken place in the 
 great mountain chains of South America during 
 the same geological epoch. From the researches of 
 an eminent naturalist and highly intelligent ob- 
 server, Mr. Charles Darwin, we learn that an 
 extensive tertiary system, analogous to that of 
 Europe, skirts both flanks of the primary rocks 
 which form the southern chain of the Andes, the 
 latter having suffered a certain degree of elevation 
 before the deposition of the former. These strata 
 are of great thickness and extent, and separable 
 
274 THE WONDERS OF GEOLOGY. LECT. III. 
 
 into two groups ; the lowermost beds, like those of 
 Auvergne, repeatedly alternate with lavas, and thus 
 denote the commencement of the eruptions of the 
 ancient craters. Over these are accumulations of 
 porphyritic pebbles, covered, at elevations of many 
 hundred feet, by beds of shells of recent species ; 
 and the sides of the mountains appear like a suc- 
 cession of sea-beaches, which have been slowly and 
 tranquilly lifted up. The altered character of the 
 tertiary deposits within the influence of the igneous 
 products, the transmutation of accumulations of 
 loose pebbles into solid, compact rocks, and the 
 occurrence of metalliferous veins in strata of com- 
 paratively modern formation, are facts so powerfully 
 exemplifying the geological principles enunciated 
 in the former lectures, that although this discourse 
 has extended to a great length, I cannot omit Mr. 
 Darwin's spirited and graphic description of these 
 phenomena, as originally communicated in a letter 
 to Professor Henslow, of Cambridge, dated Valpa- 
 raiso, March 1835. 
 
 " You will have heard of the dreadful earthquake of the 20th 
 February. I wish some of the geologists, who think the earth- 
 quakes of these times are trifling, could see how the solid rocks 
 are shivered. In the town there is not one house habitable ; 
 the ruins remind me of the drawings of the desolated eastern 
 cities. We were at Valdivia at the time, and felt the shock very 
 severely. The sensation was like that of skating over very thin 
 ice, that is, distinct undulations were perceptible. The whole 
 scene of Conception and Talesana is one of the most interesting 
 spectacles we have beheld since we left England. I was much 
 pleased at Chiloe by finding a thick bed of recent oyster-shells 
 
50. TERTIARY STRATA OF THE ANDES. 273 
 
 capping the tertiary plain, out of which grew large forest trees. 
 I can prove that both sides of the Andes have risen in this 
 recent period to a considerable height. Here the shells were 
 350 feet above the sea. On the bare sides of the Cordilleras 
 complicated dykes and wedges of variously coloured rocks are 
 seen traversing, in every possible form and shape, the same for- 
 mation, and thus proving by their intersections a succession of 
 violences. The stratification in all the mountains is beautifully 
 distinct, and owing to a variety of colouring can be seen at 
 great distances. Porphyritic conglomerates, resting on granite, 
 form the principal masses. I cannot imagine any part of the 
 world presenting a more extraordinary scene of the breaking up 
 of the crust of the globe than these central peaks of the Andes. 
 The strata in the highest pinnacles are almost universally in- 
 clined at an angle from 70 to 80. I cannot tell you how much 
 I enjoyed some of the views ; it is alone worth coming from 
 England to feel at once such intense delight. At an elevation 
 of from ten to twelve thousand feet there is a transparency in the 
 air, and a confusion of distances, and a stillness, which give the 
 sensation of being in another world. The most important and 
 most developed formation in Chili is the porphyritic concrete. 
 From a great number of sections I find it to be a true coarse 
 conglomerate or breccia, which passes by every step in slow 
 gradation to a fine clay-stone porphyry ; the pebbles and cement 
 becoming porphyritic, till at last all is blended in one compact rock. 
 The porphyries are excessively abundant in this chain, and at 
 least four-fifths of them, I am sure, have been thus produced from 
 sedimentary beds in situ. The Uspellata range is geologicallly 
 although only six or seven thousand feet high, a continuation of 
 the grand eastern chain. It has its nucleus of granite, consist- 
 ing of beds of various crystalline rocks, (which I have no doubt 
 are subaqueous lavas,) alternating with sandstone, conglome- 
 rates, and white aluminous beds, like decomposed felspar, 
 with many other curious varieties of sedimentary deposits. In 
 an escarpment of compact greenish sandstone, / found a small 
 wood of petrified trees in a vertical position, or rather the strata 
 were inclined about 20 or 30 to one point of the trees, and 70 to 
 T2 
 
276 THE WONDERS OF GEOLOGY. LECT. III. 
 
 the other ; that is, before the tilt, they were truly vertical. The 
 sandstone consists of many horizontal layers. Eleven of the 
 trees are perfectly silicified, and resemble the dicotyledonous 
 wood which I found at Chiloe and Conception ; the others, from 
 thirty to forty in number, I only know to be trees from the 
 analogy of form and position ; they consist of snow-white 
 columns of coarsely crystallized carbonate of lime. The largest 
 trunk is seven feet in circumference. They are all close toge- 
 ther, within one hundred yards, and about the same level ; no 
 where else could I find any. It cannot be doubted that the 
 layers of fine sandstone have quietly been deposited between a 
 clump of trees, which were fixed by their roots. The sandstone 
 rests on lava ; is covered by a great bed, apparently about one 
 thousand feet thick, of black augite lava ; and over this there are at 
 least five grand alternations of such rocks, and aqueous sedimentary 
 deposits, amounting in thickness to several thousand feet. Accord- 
 ing to my view of these phenomena, the granite, which forms 
 peaks of a height probably of 14,000 feet, has been fluid in the 
 tertiary epoch ; strata of that period have been altered by its 
 heat, and are traversed by dykes from the mass, and are now 
 inclined at high angles, and form regular or complicated anti- 
 clinal lines. To complete the climax, these same sedimentary strata 
 and lavas are traversed by very numerous true metallic veins of 
 iron, copper, arsenic, silver, and gold, and these can be traced to 
 the underlying granite. A gold mine has been worked close to the 
 clump of silicified trees !" 
 
 51. TERTIARY SALIFEROUS DEPOSIT. Not only 
 coal, but even extensive beds of rock salt occur in 
 the tertiary system. The celebrated salt mines of 
 Gallicia, of which M. Bou6* has given an inte- 
 resting description, belong to this epoch. The 
 deposit is nearly 3000 yards long, 1066 broad, and 
 280 yards deep. The upper part of the mine 
 
 * Journal de Geologic. 
 
52. RETROSPECT. 277 
 
 consists of green salt, with nodules of gypsum in 
 marl. The salt contains in some places lignite, 
 bituminous wood, and shells. In the lower division 
 are beds of arenaceous marls, with lignite, impres- 
 sions of plants, and veins of salt ; coarse sandstone, 
 with vegetable remains ; aluminous and gypseous 
 shale, and indurated calcareous marl, with sulphur, 
 salt, and gypsum. 
 
 52. RETROSPECT. So numerous and varied have 
 been the phenomena presented to our notice, that 
 a comprehensive retrospect is necessary, in order 
 that we may obtain a correct idea of the important 
 and highly interesting deductions resulting from 
 this general survey of the tertiary formations. 
 
 In the pliocene, or newer tertiary, which also 
 embraces the mammalian epoch of the last lecture, 
 the fossil remains in the alluvial deposits afford in- 
 contestible proof that the mammoth, mastodon, hip- 
 popotamus, dinotherium, and other colossal animals 
 of extinct species and genera, together with birds, 
 reptiles, and enormous carnivora, inhabited such 
 districts of our continents as were then dry land ; 
 while the older tertiary, or eocene, incloses the bones 
 of land animals, principally of a lacustrine character, 
 which approximate to certain races that now exist 
 in the torrid zone, but belong to extinct genera, 
 that preceded the mammoth and the mastodon. 
 The seas and lakes of that remote epoch occupied 
 areas which are now above the waters ; and rocks 
 and mountains, hills and valleys, streams and rivers, 
 
278 THE WONDERS OF GEOLOGY. LECT. III. 
 
 diversified the surface of countries which are now 
 destroyed or entirely changed ; and whose past ex- 
 istence is revealed by the spoils which the streams 
 and rivers have accumulated in the ancient lakes 
 and deltas. The ocean abounded in mollusca, crus- 
 tacea, and fishes, a large proportion of which is 
 referable to extinct species. Crocodiles, turtles, 
 birds, and insects, were contemporary with the 
 palaeotherium, and anthracotherium ; and animal 
 organization, however varied in certain types, pre- 
 sented the same general outline as in modern 
 times ; the extinction of species and genera being 
 then, as now, in constant activity. The vegetable 
 world also contained the same great divisions ; there 
 were forests of oak, elm, and beech ; of firs, pines, 
 and other coniferous trees; palms, tree-ferns, and 
 the principal groups of modern floras ; while the 
 water, both salt and fresh, teemed with the few 
 and simple forms of vegetable structure peculiar 
 to that element. The state of the inorganic world 
 is not less manifest : the abrasion of the land by 
 streams and rivers, the destruction of the sea- 
 shores by the waves, and the formation of beach 
 and shingle, the desolation inflicted by volcanic 
 eruptions, all these operations were then, as now, 
 in constant action. The bed of an ancient sea, con- 
 taining myriads of the remains of fishes, Crustacea, 
 and shells, now forms the site of the capital of 
 Great Britain ; and accumulations of tropical fruits 
 and plants, drifted by ancient currents from other 
 
,;2. RETROSPECT. 279 
 
 climes, constitute islands in the estuary of the 
 Thames ; while the sediments of lakes and gulfs, 
 teeming with the skeletons of .beings which are 
 blotted out from the face of the earth, compose the 
 soil of the metropolis of France. 
 
 Although the changes in the relative level of the 
 land and sea during this epoch were numerous and 
 extensive, yet one region still preserves traces of 
 its original physical geography ; and although the 
 earthquake has rent its mountains to their very 
 centre though hundreds of volcanoes have again 
 and again spread desolation over the land and 
 inundations and mountain torrents have excavated 
 valleys, and chequered the plains with ravines and 
 water-courses yet the grand primeval features of 
 that country remain ; and we can trace the boun- 
 daries of its ancient lakes, and the succession of 
 changes it has undergone from the first outbreak of 
 its volcanoes, to the commencement of the present 
 state of repose. The lowermost lacustrine deposits 
 in Auvergne, which are spread over the foundation 
 rock of granite unmixed with igneous productions, 
 mark the period antecedent to the volcanic era ; 
 while the intrusions of lava and scoriae in the super- 
 incumbent strata, denote the first eruptions of Mont 
 Dome. The succeeding period of tranquillity is 
 recorded in characters alike intelligible. The slow 
 deposition of calcareous mud the incrustation of 
 successive generations of aquatic insects, Crustacea, 
 and mollusca, and we may even add of infusoria 
 
280 THE WONDERS OF GEOLOGY. LECT. III. 
 
 the imbedding of the bones of mammalia, birds, and 
 reptiles the accumulation of lignite and other vege- 
 table matter are data from which we may restore 
 the ancient country of Central France. 
 
 It was a region encircled by a chain of granite 
 mountains, watered by numerous streams and rivu- 
 letSj and possessing lakes of vast extent. Its soil 
 was covered with luxuriant vegetation, and peopled 
 by palseotheria, anoplotheria, and other terrestrial 
 mammalia ; the crocodile and turtle found shelter 
 in its marshes and rivers ; aquatic birds frequented 
 its fens, and sported over the surface of its lakes ; 
 while myriads of insects swarmed in the air, and 
 passed through their wonderful metamorphoses in 
 the waters. In a neighbouring region,* herds of 
 ruminants and other herbivora, of species and 
 genera now no more, with birds and reptiles, were 
 the undisturbed occupants of a country abounding 
 in palms and tree-ferns, and having rivers and lakes, 
 with gulfs which teemed with the inhabitants of the 
 sea; and to this district the fiery torrents of the 
 volcano did not extend. But to return to Auvergne 
 a change came over the scene violent eruptions 
 burst forth from craters long silent the whole 
 country was laid desolate its living population 
 was swept away all was one vast waste, and steri- 
 lity succeeded to the former luxuriance of life and 
 beauty. Ages rolled by the mists of the mountains 
 and the rains, produced new springs, torrents, and 
 * The Paris basin is about 220 miles from Auvergne. 
 
 . 
 
52. RETROSPECT. 281 
 
 rivers a fertile soil gradually accumulated over 
 the cooled lava currents and the beds of scoriae, 
 to which the sediments of the ancient lakes, borne 
 down by the streams, largely contributed. Another 
 vegetation sprang up the mammoth and mastodon, 
 with enormous deer and oxen, now quietly browsed 
 in the verdant plains other changes succeeded 
 those colossal forms of life in their turn passed 
 away, and at length the earlier races of mankind 
 took possession of a country, which had once more 
 become a scene of fertility and repose. 
 
 To those who have favoured me with their atten- 
 tion through these discourses, it cannot be necessary 
 to insist that the changes in organic and inanimate 
 nature, which I have thus rapidly portrayed, are 
 supported by proofs so incontrovertible, and traced 
 in language so intelligible, as to constitute a body 
 of evidence with which no human testimony can 
 compete. It is true that the time required for this 
 succession of events must have extended over an 
 immense period; but, as I have before remarked, 
 time and change are great only in relation to the 
 beings which note them, and every step we take in 
 geology shows the folly and presumption of attempt- 
 ing to measure the operations of nature by our own 
 brief span. " There are no minds," says Mr. Scrope, 
 " that would for one moment doubt that the God of 
 Nature has existed from all eternity ; but there are 
 many who would reject as preposterous, the idea 
 of tracing back the history of His works a million 
 
282 THE WONDERS OF GEOLOGY. LKCT. III. 
 
 of years. Yet what is a million, or a million of 
 millions of years, when compared to eternity ? " * 
 
 Germany presents us with an interesting series 
 of analogous changes, effected in a later era. The 
 outburst of the now extinct volcanoes of the Rhine, 
 the accumulation of fluviatile silt over the plains, 
 and the subsequent elevation of the whole country, 
 show that these physical mutations were not con- 
 fined to a single region or period. 
 
 In the Andes, the enormous disruptions and 
 elevations of the most ancient as well as modern 
 deposits, teach us, that through a long lapse of 
 ages, the volcanic fires of South America have acted 
 with intense energy; and yet more, that the melting 
 and transmutation of loose materials into compact 
 rocks, the conversion of incoherent strata into solid 
 stone, and even the sublimation of gold and other 
 metals into fissures and veins, are phenomena which 
 have taken place since our seas were peopled by 
 mollusca of existing species. The importance of 
 these extraordinary and interesting facts will be 
 rendered more obvious in a subsequent lecture. 
 
 53. CONCLUDING REMARKS. In conclusion, it 
 will be useful to inquire, even though some repe- 
 tition may be incurred, what are the legitimate 
 inferences from the facts that have been placed 
 before us, as to the condition of the earth and its 
 inhabitants during the tertiary epoch? Was there, 
 as some have supposed, an essential difference in 
 * Geology of Central France. 
 
53. CONCLUDING REMARKS. 283 
 
 the constitution of the earth? was its surface more 
 covered with lakes and marshes than now? and 
 did animal life more abound in those types, which 
 are suitable to a lacustrine condition? or have 
 such conclusions been drawn from a partial view of 
 the phenomena, and do the facts only warrant the 
 inference that certain regions which are now dry 
 land were in ancient times occupied by vast lakes, 
 and that there may have existed contemporaneously 
 as great an extent of dry land as at present, in areas 
 now buried beneath the ocean ? In the fossilized 
 remains of the tertiary population of the land and 
 waters, we find all the grand types of the existing 
 animal creation terrestrial, lacustrine, and marine 
 mammalia herbivora, carnivora, birds of every 
 order, and of numerous species and genera rep- 
 tiles, fishes, Crustacea, insects, zoophytes, and even 
 those living atoms, the infusoria* in short, all the 
 leading divisions, and even sub-divisions of animal 
 existence. In the vegetable world, as I have already 
 remarked, the same general analogy is maintained. 
 And as all these varied forms of being required 
 physical conditions suitable to their respective or- 
 ganizations, we have at once conclusive evidence 
 that the general constitution of the earth, during 
 the tertiary epoch, could not have essentially differed 
 from the present. Dry land and water, continents 
 
 * In tertiary strata the remains of beings of which thousands 
 of millions would occupy but a cubic inch have been discovered. 
 They will be described hereafter. 
 
284 THE WONDERS OF GEOLOGY. LECT. III. 
 
 and islands, existed then, as now, their geogra- 
 phical distribution may have varied, the tem- 
 perature in certain latitudes may have been much 
 higher, countries may have existed in areas now 
 covered by water, and marshes and fens have pre- 
 vailed in regions now arid and waste ; but the same 
 agents of destruction and of renovation were then, 
 as now, in constant activity. It is true that immense 
 numbers of large mammalia lie buried in regions 
 where it is utterly impossible such creatures could 
 now find subsistence, and in latitudes whose climates 
 are unsuitable to such forms of organization. But 
 some of these apparent anomalies may be explained 
 by the fact, that the alluvial beds in which these 
 remains occur cannot have been the sites of the dry 
 land on which these lost beings existed; they are 
 the sediments of ancient lakes the deltas of former 
 rivers the estuaries of seas they are formed of 
 the detritus of the land transported from a distance. 
 If the Gulf-stream annually strews the shores of the 
 Hebrides with the fruits of torrid climes, the currents 
 of the ancient seas must have produced analogous 
 results; and in our attempt to interpret past changes, 
 it must not be forgotten that they have most pro- 
 bably been produced by causes similar to those 
 which are still in action. I do not question the 
 assumption that the countries containing these fossil 
 remains may have enjoyed a milder climate during 
 the tertiary epoch than at present ; or that in still 
 more ancient periods there may not have prevailed 
 
53. CONCLUDING REMARKS. 285 
 
 all over the world a much higher temperature than 
 now, dependent on the internal condition of our 
 planet. But it appears to me that the variation of 
 climate which a change in the distribution of the 
 land and water would occasion, as suggested by 
 Mr. Lyell,* and a difference in the radiation of 
 heat from internal sources, as explained by Sir 
 J. Herschel and Mr. Babbage (page 97), may ac- 
 count for the phenomena which our examination of 
 the tertiary formation has revealed. 
 
 The occurrence of groups of animals of the same 
 families, in certain districts, is in strict conformity 
 with the distribution of living species, in regions 
 not under the control of man. Thus when ancient 
 France presented a system of lakes, animals fitted 
 for such physical conditions found there the means 
 of subsistence when the vast plains and forests of 
 America were adapted for colossal mammalia, there 
 the mastodon and the mammoth obtained food and 
 shelter and when the former continent of Europe 
 swarmed with herbivora, the carnivorous tribes, as 
 the lion and the tiger, the bear and the hyena, ob- 
 tained the support which their habits and economy 
 required. 
 
 One striking feature in the events that have 
 passed in review before us, is the immense scale on 
 which the extinction of species and genera has been 
 effected : but it must be remembered that our 
 observations have extended over a period of vast 
 * Principles of Geology, vol. i. chap. vii. 
 
286 THE WONDERS OF GEOLOGY. LECT. III. 
 
 duration, and that we therefore have seen the 
 aggregate effects of a law, which even before our 
 eyes is producing great and important modifications 
 in the system of animated nature. 
 
 Thus the tertiary epoch displays to us a state of 
 the globe replete with life and happiness : the phy- 
 sical constitution of the earth's surface being then, 
 as now, admirably adapted to the habits and economy 
 of the beings it was designed to support. In the 
 most ancient periods, forms of life prevailed which 
 gradually became extinct, and were succeeded by 
 others which in their turn also passed away ; and 
 if we trace the varying types of being from the 
 earliest ages, we perceive a gradual approach to 
 the present condition of organic existence ; the 
 grand line of separation between the present and 
 the past being the creation of the human race. 
 From that period, in proportion as man has ex- 
 tended his dominion over the earth, many races of 
 animals have been either exterminated, or modified 
 by his caprices or necessities ; and it cannot be 
 doubted, that in the lapse of a few thousand years, 
 a total change will have been effected by human 
 agency alone, in the geographical distribution and 
 in the relative numerical proportion of the existing 
 genera and species. 
 
LECTURE IV. 
 
 1. Introductory remarks. 2. Secondary formations. 3. The chalk for- 
 mation. 4. Chalk and flint. 5. Flint nodules. 6. Organic remains 
 in flint. 7. Sulphuret of iron. 8. Maastricht beds. 9. St. Peters 
 mountain. 10. Mosaesaurus of Maastricht. 11. Lower group of the 
 chalk. 12. Organic remains of the chalk. 13. Fossil vegetables. 
 14. Fossil zoophytes. 15. Radiaria and crinoidea. 16. Echinites. 
 17. Shells of the chalk. 18. Cephalopoda. 19. The belemnite. 20. 
 The nautilus. 21. The ammonite, or cornu ammonis. 22. Turrilite, 
 hamite, &c. 23. Spirolinites. 24. Infusoria in flint. 25. Crustacea 
 of the chalk. 26. Fishes of the chalk sharks. 27. Fossil salmon, 
 or smelt. 28. Macropoma, and other fishes of the chalk. 29. Reptiles 
 of the chalk. 30. Review of the chalk formation. 31. Geology of the 
 south-east of England. 32. Geological phenomena between London 
 and Brighton. 33. The wealden. 34. Wealden of the Sussex coast. 
 35. Pounceford. 36. Sub-division, and extent of the wealden. 37. 
 Quarries of Tilgate forest. 38. Rippled sandstone. 39. Wealden of 
 the Isle of Wight. 40. Isle of Purbeck. 41. Petrified forest of the 
 Isle of Portland. 42. Modern submerged forest. 43. Fossils of the 
 wealden. 44. Fossil vegetables ferns. 45. Clathraria and endo- 
 genites. 46. Seed-vessels. 47. Fossil shells. 48. Sussex marble. 
 49. Fossil cypris. 50. Fishes. 51. Reptiles of Tilgate forest. 52. 
 Fossil turtles. 53. Fossil crocodiles. 54. The Swanage crocodile. 
 55. The plesiosaurus. 56. The megalosaurus. 57. The iguanodon. 
 58. The Maidstone iguanodon. 59. Size of the iguanodon. 60. The 
 hylaeosaurus. 61. Flying reptiles. 62. Fossil birds. 63. The country 
 of the iguanodon. 64. Sequence of geological changes. 65. Retro- 
 spect of geological mutations. 
 
 1. INTRODUCTORY REMARKS. The knowledge we 
 have acquired from our investigation of the pheno- 
 mena described in the previous lectures, will mate- 
 rially facilitate our geological progress, by enabling 
 
288 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 us to comprehend the former effects of those 
 agencies, by which the surface of the earth has 
 been renovated and maintained. 
 
 The elevation of the beds of seas and rivers, and 
 their conversion into fertile countries the submer- 
 gence of islands and continents beneath the waters 
 of the ocean the rapid formation of conglomerates 
 from shells and corals on the sea shore the accu- 
 mulation of beach and gravel, and the inhumation 
 of animals and vegetables the slow deposition of 
 sediment by lakes and rivers the imbedding of in- 
 numerable generations of insects, and the formation 
 of limestone from their almost invisible skeletons 
 the construction of solid stone out of fragments of 
 bones, and rocks, shivered by earthquakes the 
 engulfing, in estuaries and inland seas, of land 
 animals, birds, and reptiles the consolidation of 
 both organic and inorganic substances into rock, 
 by the infiltration of flint and lime by thermal 
 waters the transmutation of submerged forests 
 into coal and lignite the destructive and conser- 
 vative effects of volcanic eruptions the conversion 
 of sand, gravel, and clay, into homogeneous masses 
 by heat, and even the production of metalliferous 
 veins of gold and silver all these phenomena have 
 passed in review before us, although our inquiries 
 have extended through periods which, however vast 
 and remote in relation to the records of our race, 
 are but brief and modern in the physical history of 
 the earth. 
 
2. SECONDARY FORMATIONS. 289 
 
 The geological events previously described, al- 
 though forming a connected series, may be divided 
 into periods, each of which is marked by certain 
 zoological characters ; namely, 1st. The modern, or 
 human epoch; 2d. the elephantine, characterised by 
 the preponderance of large pachydermata ; 3d. the 
 palcBotherian, in which animals allied to the tapir 
 prevailed, and Europe presented a system of gulfs 
 and lakes. 
 
 2. SECONDARY FORMATIONS. I hasten to the 
 consideration of another and antecedent geological 
 epoch, that which comprehends the Secondary 
 Formations. Hitherto our attention has been prin- 
 cipally directed to deposits confined within com- 
 paratively limited areas, as the basins of lakes, 
 gulfs, estuaries, and inland seas ; and accumulations 
 of drifted materials produced by the action of 
 torrents, rivers, and inundations. We have now 
 arrived on the shores of that ocean, of whose 
 spoils the existing islands and continents are prin- 
 cipally composed ; the fathomless depths of the 
 ancient seas are spread before us, and the myriads 
 of beings which sported in their waters, and lived 
 and died in those profound abysses, remain, like 
 the mummies of ancient Egypt, the silent yet elo- 
 quent teachers of their own eventful history. 
 
 A reference to the Tabular Arrangement of the 
 
 Strata (Plate VII. and page 194) will show that 
 
 the secondary formations constitute nine principal 
 
 subdivisions, forming four natural groups, viz. 
 
 u 
 
290 THE WONDERS OP GEOLOGY. LECT. IV. 
 
 the cretaceous, oolitic, saliferous, and carboniferous 
 systems, each containing littoral, marine, and 
 oceanic deposits; sandstones having been formed 
 amidst the agitated waters of the sea shores, clays 
 in tranquil bays and gulfs, and limestones in deep 
 water. I purpose, in the present discourse, to ex- 
 plain the geological characters of the first two of 
 the series, namely, the CHALK and the WEALDEN,* 
 The former is composed of rocks that have been 
 accumulated in the depths of a sea of great extent ; 
 the latter, of the sediments of a vast delta; the 
 one affording a striking illustration of the nature of 
 oceanic, and the other of fluviatile deposits. 
 
 In the diagram (Plate VII.) the wealden (3*) is 
 represented as an intercalation between the chalk 
 and the oolite (3, 4), because it is of limited ex- 
 tent, and where absent, as in the midland counties of 
 England and on the continent, the chalk lies upon 
 the oolite, as will be shown in the next lecture. As 
 both the chalk and the wealden are fully developed 
 in the south-east of England, the phenomena about 
 to be described may be examined with but little 
 inconvenience; and an extensive collection of the 
 peculiar fossils of these formations may be seen in 
 my museum. "j- 
 
 * The term Weald is derived from the German Wald, a wood 
 or forest. The Weald of Sussex was formerly an impenetrable 
 forest, called Anderida by the Romans, and Andredswald by 
 the Saxons. 
 
 f Now in the British Museum. See Descriptive Catalogue 
 of the Mantellian Museum, 8vo. fifth edition. 
 
3. THE CHALK FORMATION. 291 
 
 3. THE CHALK FORMATION. The pure white 
 limestone, called chalk, is known to every one ; but 
 in the nomenclature of geology, the name is applied 
 to a group of deposits very dissimilar in their litho- 
 logical composition, but agreeing in the nature of 
 the organic remains which they contain, and evi- 
 dently referable to the same geological epoch. The 
 series essentially consists of green and ferruginous 
 sands, clays, marls, and grey and white limestones, 
 abounding in marine remains. With this expla- 
 nation it will be convenient to employ the term in 
 its extended sense. The chalk formation comprises 
 the following subdivisions : 
 
 1. Upper chalk, with flints ... 1 Craie blanche of the 
 
 2. Lower chalk, without flints . . ) French geologists. 
 
 3. Chalk marl Craie tufeau. 
 
 4. Firestone, malm-rock, upper green ) ^^ ^ 
 
 sand, or glauconite . . . . ) 
 
 5. Gait, or Folkstone marl .... 
 
 6. Shanklin, or lower green sand . . Glauconie sableuse. 
 
 The chalk is generally white, but in some countries 
 is of a deep red, and in others of a yellow colour ; 
 nodules and veins of flint occur in the upper, 
 but seldom in the lower chalk. The marl is an 
 argillaceous limestone, which generally prevails 
 beneath the white chalk ; it sometimes contains a 
 large intermixture of green sand, and then is called 
 firestone, or glauconite. The gait is a stiff, blue or 
 black clay, abounding in shells, which frequently 
 possess a pearly lustre. The Shanklin, or lower 
 green sand, is a triple alternation of sands and sand- 
 u2 
 
292 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 stone with clays ; beds of chert and fuller's earth 
 are also found in some localities. 
 
 On the continent, the series of deposits here 
 enumerated is largely developed, and taken as a 
 whole, the chalk formation may be described as 
 extending over a great part of the British Islands, 
 Northern France, Germany, Denmark, Sweden, 
 European and Asiatic Russia, and of the United 
 States of North America. Over this vast extent, 
 the organic remains present certain general cha- 
 racters, sufficiently obvious to determine the nature 
 of the formation. Whether imbedded in pure white 
 limestone, coarse sandstone, blue clay, loose sand, 
 or compact rock, the fossils consist of the same 
 species of shells, corals, sponges, echinites, belem- 
 nites, ammonites, and other marine exuviae ; fishes, 
 reptiles, wood, and plants. The strata are boldly 
 displayed along the Hampshire, Sussex, and Kentish 
 coasts ; the precipitous headland of Beachy Head, 
 and the cliffs at Dover are well known ; these 
 natural sections exhibit the manner in which the 
 beds have been disrupted, and thrown into various 
 inclined positions (see PL 9, fig. 1). At Devizes, in 
 Wiltshire, the strata lie nearly horizontal, and in the 
 following order : 1. White chalk. 2. Glauconite. 
 3. Gait 4-. Shanklin Sands (see PL 9, fig. 2). 
 
 4-. CHALK AND FLINT.* The white chalk is 
 
 * See The 'Fossils of the South Downs, or, Illustrations 
 the Geology of Sussex, 1 vol. 4to. with 42 plates. Geology of 
 the South-East of England, 1 vol. 8vo. Dr. Fitton's Memoirs 
 
5. FLINT NODULES. 293 
 
 composed of lime and carbonic acid, and may have 
 been precipitated from water holding lime in solu- 
 tion, from which an excess of carbonic acid was 
 expelled. But a large proportion of the purest 
 chalk appears to be in great part, if not wholly, 
 composed of the remains of corals and shells, and 
 in some quarries whole layers are formed of the 
 ossicula of star-fish and other radiaria, with micro- 
 scopic species of polyparia and shells.* The nodules 
 and veins of flint which occur in the chalk, show that 
 water holding silex in solution must have been very 
 abundant during the cretaceous period. The power 
 possessed by thermal waters of dissolving silicious 
 earth, depositing flint, and occasioning the silieifi- 
 cation of vegetable substances, is strikingly exem- 
 plified in the Geysers of Iceland, as I have already 
 explained (p. 83). The perfect fluidity of the silex 
 before consolidation, is shown by the sharp impres- 
 sions which the flints bear of shells and other marine 
 bodies ; and upon breaking the nodules, zoophytes, 
 related to sponges and alcyonia, with other organic 
 remains, are found enveloped ; the silicious matter 
 having so penetrated the delicate structure of the 
 originals, that polished sections display the most 
 minute organization of the inclosed bodies. 
 
 5. FLINT NODULES. Flints, or silicious nodules, 
 
 on the Shanklin, or Green Sands, in which many of the fossils 
 are beautifully delineated; Geological Transactions, vol. iv. 
 New Series. 
 
 * Mr. Lonsdale. 
 
294 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 occur in the chalk in horizontal rows, which present 
 some degree of regularity, but are placed at unequal 
 distances from each other. This arrangement has 
 probably arisen from the chalk and flint having 
 been held in suspension or solution in the same 
 fluid, and precipitated into the basin of the ocean : 
 when consolidation took place, the silicious molecules 
 separated from the cretaceous, on the well-known 
 principles of chemical affinity ; the sponges and 
 other zoophytes acting as nuclei or centres, around 
 which the silicious matter coagulated. This pro- 
 cess receives illustration from the fact, that when 
 different substances in a state of extreme division 
 are mixed together, they have a tendency to sepa- 
 rate, and re-arrange themselves in masses more 
 nearly homogeneous ; thus in the materials pre- 
 pared in the potteries, a separation of pounded flint 
 from aluminous earth takes place, and silicious con- 
 cretions are formed, if the mixture be not constantly 
 agitated. The marked stratification of the chalk 
 shows that it was deposited periodically ; and it is 
 not unusual to find veins of flint running through 
 and filling up crevices in the strata beneath ; an 
 appearance that can only be attributed to the lower 
 beds having been consolidated, and subsequently 
 fissured, before the superincumbent stratum was 
 precipitated. 
 
 6. ORGANIC REMAINS IN FLINT. The organic 
 remains which usually occur in the chalk are also 
 found in the flints; but certain fossils prevail far 
 
7. SULPHURET OF IRON. 295 
 
 more abundantly than others ; a circumstance in 
 all probability attributable to the constituent sub- 
 stance of the original having been favourable to 
 the process of silicification. The softer zoophytes, 
 as the alcyonia, spongiae, &c. absolutely swarm in 
 the flints ; and infusoria are equally abundant. 
 Fishes are occasionally found enveloped in a flint 
 nodule ; and their minute scales have been detected 
 by Mr. Reade with the aid of the microscope, in 
 almost every fragment of flint. Wood which has 
 been perforated by lithodomi, and silicified, is not 
 scarce ; and conferva? and fuci are sometimes found 
 floating, as it were, in the liquid silex. Bones of 
 reptiles and fishes are often, impacted in a mass of 
 flint, but in no instance that I have observed has 
 the silex permeated the osseous structure. When 
 corals, echini, shells, &c. are imbedded, the sub- 
 stance of the fossils is calcareous, not silicious ; 
 they appear to be simply enveloped by a silicious 
 paste, which had not the power of penetrating the 
 interstices, nor of producing any chemical change. 
 
 7. SULPHURET OF IRON. Iron pyrites is the 
 only metalliferous ore that occurs abundantly in the 
 chalk of England. The large nodular masses that 
 are found on the Downs and in the ploughed fields, 
 are commonly termed thunderbolts. This mineral 
 sometimes forms groups of octahedral crystals 
 of great elegance and regularity, and frequently 
 occupies the cavities of shells and echini ; terebra- 
 tulee and pectens also occasionally occur in masses 
 
296 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 of this substance. The bones and scales of the 
 fishes are invariably coloured with a ferruginous 
 stain, arising from a curious chemical process ; sul- 
 phuretted hydrogen was evolved during the putre- 
 faction of the animal substance, but the sulphur 
 entering into combination with the iron contained 
 in the surrounding water, sulphuret of iron was 
 formed, and hence the fossil fishes derived the rich 
 colour which so beautifully contrasts with the white 
 chalk in which they are imbedded. 
 
 8. MAESTRICHT BEDS. I have described the 
 usual lithological characters of the cretaceous strata, 
 arid if our observations were restricted to these de- 
 posits as they occur in England, the difference 
 between the uppermost secondary formation and 
 the superimposed tertiary would be most striking, 
 both as regards the nature of the rocks and their 
 organic remains. But, as I shall hereafter explain, 
 the white chalk of England appears to have been 
 formed in the profound depths of the sea, for we 
 have rarely any intermixture of terrestrial or littoral 
 productions ; even pebbles are of unfrequent occur- 
 rence. At Castle Hill, near Newhaven (p. 223), 
 and at Alum Bay, in the Isle of Wight (p. 224), 
 the cerithia (Tab. 38, fig. 4), turritella, and other 
 tertiary shells, abound in the sand and clay spread 
 over the surface of the chalk, in which no similar 
 shells can be detected. On the continent, how- 
 ever, there exist deposits which form, as it were, a 
 link between the tertiary and the secondary. In 
 
9. ST. PETER'S MOUNTAIN, NEAR MAESTRICHT. 297 
 
 the valley of the Meuse there is a fine series of 
 strata, the uppermost of which contains many 
 genera of shells that are plentiful in the tertiary, 
 and passing imperceptibly into limestone with cre- 
 taceous fossils and flint nodules, is finally lost in 
 the chalk. At Gosau, in the Eastern Alps, beds 
 occur which appear to belong to the same interme- 
 diate era ; and in the United States, the researches 
 of Dr. Morton have proved the existence of analo- 
 gous deposits. 
 
 9. ST. PETER'S MOUNTAIN, NEAR MAESTRICHT. 
 The quarries of St. Peter's Mountain have long 
 been celebrated for their remarkable fossils ; but 
 the true geological characters of the strata were 
 first determined by Dr. Fitton. St. Peter's Moun- 
 tain, in which the quarries are situated, is a cape 
 or headland between the Meuse and the Jaar, and 
 forms the extremity of a range of hills which bounds 
 the western side of the valley of the Meuse. The 
 mountain commences at the distance of a mile 
 south of Maestricht, and extends in a direction 
 towards Liege for about three leagues ; it presents 
 an almost perpendicular escarpment* towards the 
 river. A section of the hills affords the following 
 succession of strata : 
 
 1. Lowermost : white chalk, with layers of flint 
 nodules. 
 
 2. Chalk very hard and gritty. 
 
 3. Calcareous freestone of a yellow fawn colour, 
 abounding in fossils. Numerous layers of flint 
 
298 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 occur throughout the entire series, and present the 
 usual characters of the silicious nodules of the 
 chalk formation. The Maestricht freestone is so 
 extremely soft in the quarry, that it may easily be 
 cut with a knife, but it becomes harder and of a 
 lighter colour by exposure to the air.* The beds 
 of limestone have a total thickness of about 500 
 feet. Excavations have for centuries been carried 
 on in the strata of freestone, and from the immense 
 quantities of stone removed, extensive caverns and 
 galleries now traverse the heart of the mountain. -j- 
 Shells, corals, Crustacea, teeth of fishes, and other 
 marine remains, occur in profusion ; with wood 
 perforated by lithodomi, and the bones of a large 
 and very remarkable reptile. 
 
 10. THE MOS^ESAURUS ; OR FOSSIL REPTILE OF 
 MAESTRICHT. The bones and teeth of an un- 
 known animal which were occasionally found in 
 the limestone, had long since directed the attention 
 of naturalists to the quarries of St. Peter's Moun- 
 tain. In 1770 M. Hoffmann, who was forming a 
 collection of organic remains, had the good fortune 
 
 * The avidity of collectors has induced the quarrymen to 
 practise an ingenious fraud upon strangers : teeth and bones of 
 the horse, boar, &c. are carefully imbedded in blocks of the 
 limestone while it is soft ; and when the stone becomes hard, 
 the specimens are offered for sale as genuine fossils from the 
 quarries. The deception may be detected by immersing the 
 specimens in water. 
 
 f See Hist. Nat. de la Montagne de St. Pierre, by Faujas 
 St Fond, 1 vol. 4to. with splendid engravings. 
 
10. THE MOS^SAURUS. 299 
 
 to discover a specimen, which has conferred addi- 
 tional interest on this locality : some workmen, on 
 blasting the rock in one of the caverns of the 
 
 TAB. 47. REMAINS OF THE MOSJESAURUS. 
 
 Discovered at Maestricht, by M. Hoffmann, in 1770; now in the 
 Museum at Paris. 
 
 (Four and a half feet by two and a half.) 
 
 interior of the mountain, perceived, to their asto- 
 nishment, the jaws of an enormous animal attached 
 to the roof of the chasm. The discovery was 
 immediately made known to M. Hoffmann, who 
 repaired to the spot, and for weeks presided over 
 the arduous task of separating from the rock the 
 mass of stone containing the remains. His labours 
 were at length repaid by the successful extrication 
 
300 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 of the specimen, which he conveyed in triumph to 
 his house. Unfortunately, the canon of the cathe- 
 dral, which stands on the mountain, claimed the 
 fossil in right of being lord of the manor, and suc- 
 ceeded, by a most unjust and expensive law-suit, in 
 obtaining this precious relic (Tab. 47). It remained 
 in his possession for years, and Hoffmann died with- 
 out regaining his treasure, or receiving any com- 
 pensation. The French Revolution broke out, and 
 the armies of the Republic advanced to the gates 
 of Maestricht ; the town was bombarded, but by 
 desire of the committee of savans, who accompanied 
 the French troops, the artillery was not allowed 
 to play on that part of the city in which the cele- 
 brated fossil was known to be contained. In the 
 meanwhile the canon, shrewdly suspecting why 
 such peculiar favour was shown to his residence, 
 concealed the specimen in a secret vault ; but when 
 the city was taken, the French authorities compelled 
 him to give up his ill-gotten prize, which was im- 
 mediately transmitted to the Jardin des Plantes, at 
 Paris, where it still forms one of the most striking 
 objects in that magnificent collection. It is but 
 just to add, that the relatives of Hoffmann were 
 rewarded by the French commissioners. The model 
 of this specimen in my museum was presented to 
 me by Baron Cuvier ; it consists of the jaws, teeth, 
 palate-bone, vertebrae, and os guadratum, a bone 
 possessed by some reptiles, and in which the audi- 
 tory cells are contained. There are portions of jaws 
 
11. LOWER GROUP OF THE CHALK FORMATION. 301 
 
 with teeth of the mosaesaurus in the British Museum. 
 The original was a reptile, holding an intermediate 
 place between the monitor and iguana, about twenty- 
 five feet long, and furnished with a tail of such 
 construction as must have rendered it a powerful 
 oar, enabling the animal to stem the waves of the 
 ocean, of which Cuvier supposes it to have been an 
 inhabitant. The vertebrae before you belong to the 
 mosaesaurus, and were discovered in a chalk quarry 
 near Lewes.* A remarkable specimen was found 
 a short time since in the chalk of Kemp-town ; it 
 is a vertebra of the tail, partially invested with 
 flint, which has consolidated around it without ob- 
 scuring its essential characters. These teeth, from 
 North America, collected by Dr. Morton, appear 
 to belong to the same species as those from Maes- 
 tricht, and additional proof is thus afforded of the 
 original extension of the ocean of the chalk over 
 the area now occupied by the Atlantic. 
 
 11. LOWER GROUP OF THE CHALK FORMATION. 
 The lower division of the chalk formation com- 
 prises the marl, glauconite, gait, and Shanklin sands 
 (see page 291); and these deposits are constant in 
 their character and position in the south-east of 
 England. Near Southbourn, on the Sussex coast, 
 the marl, gait, and Shanklin sand, may be seen rising 
 in succession on the north of the South Downs; while 
 on the coast of Kent, the same group emerges from 
 beneath the chalk on the south side of the North 
 * Geology of the South-East of England, p. 146. 
 
302 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 Downs (see Plate IX. fig. 1). The relative position 
 of these beds is well displayed at Copt Point, near 
 Folkstone ; the gait constitutes the immediate face 
 of the cliff, and reposes on the. Shanklin sand, which 
 forms the base (Tab. 48). Eastware Bay is cele- 
 brated for the abundance of gait fossils, which are 
 constantly being washed out of the marl by the 
 
 Folkstone Hill. 
 
 TAB. 48. SECTION AT EASTWARE BAY, NEAR FOLKSTONE. 
 
 1. The chalk. 2. Marl and glauconite. 3. Gait. 4. Shanklin sand. 
 
 (By Dr. Fitton.) 
 
 action of the sea. The series may be traced with 
 more or less distinctness around the denudation of 
 the wealden, encircling the fresh-water strata. The 
 lowermost member, the Shanklin sand, rises into 
 more importance towards the west, and in Surrey, 
 Hampshire, and western Sussex, forms a line of 
 bold hills, which run parallel with the chalk downs, 
 and rival them in altitude; a valley of gait generally 
 intervenes between the sand and chalk, as at Rei- 
 gate (Plate IX. i.) The Shanklin sand is subdivided 
 
12. ORGANIC REMAINS OF THE CHALK. 303 
 
 into three groups. The uppermost, which is almost 
 100 feet in thickness, consists of red, green, white, 
 grey, and yellow sand, with concretions of chert 
 and chalcedony, which, in the Blackdown hills of 
 Devonshire, contain immense numbers of silicified 
 shells. The beds of the second group have a large 
 admixture of clay and oxide of iron, and are so 
 retentive, that pools of water are numerous in the 
 tracts they occupy, and springs burst forth at their 
 junction with the superincumbent sand. The lower- 
 most division abounds in green and grey sands, and 
 contains numerous concretionary masses and beds 
 of the grey arenaceous limestone, well known as 
 the " Kentish rag." At Shanklin Chine, in the Isle 
 of Wight, these beds form the most characteristic 
 feature of that picturesque spot, from whence the 
 name of the strata is derived. In the north-east of 
 Ireland, the Shanklin sand constitutes an important 
 feature. On the continent it is found accompanying 
 the upper members of the chalk formation, and is 
 well displayed in Saxony, and along the Alps and 
 the Carpathian mountains. In North America, 
 arenaceous strata appear to be the equivalent of the 
 chalk of Europe, for they abound in the usual 
 cretaceous fossils, as ammonites, nautili, hamites, 
 scaphites, belemnites, echinites, &c. 
 
 12. ORGANIC REMAINS OF THE CHALK. The 
 fossils of the chalk are very numerous, and com- 
 prise all the usual forms of marine animals, with the 
 exception of cetacea. Particular genera and species 
 
,304 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 appear, however, to be restricted to certain sub- 
 divisions of the formation. Thus in the white chalk, 
 there are many species of shells that do not occur 
 in the other divisions of the group. The marl and 
 gait are also characterised by peculiar forms, and 
 the Shanklin sands abound in shells and zoophytes, 
 that are wanting in the other cretaceous beds. The 
 genera and species of the mollusca must therefore 
 have varied during the period of the deposition of 
 the chalk ; some kinds prevailed at the commence- 
 ment of the formation, and became extinct at a 
 subsequent epoch ; while other forms appear for 
 the first time. Some localities are also found to 
 abound in species which do not occur in others ; 
 these shells must therefore have been spread over 
 limited areas ; in other words, the inhabitants of 
 the chalk ocean had geographical limits assigned 
 them, as is the case with the existing species. 
 
 The mode of preservation varies in the different 
 beds. The shells, stony polyparia, and radiaria of 
 the white chalk, are generally transmuted into car- 
 bonate of lime having a spathose structure, doubtless 
 the result of high temperature, acting under great 
 pressure (see page 91). Their cavities are frequently 
 filled with chalk, flint, or sulphuret of iron ; in 
 many instances they are hollow,' or lined with crys- 
 tals of carbonate of lime. The softer zoophytes 
 are silicified, and there is scarcely a flint nodule in 
 which their remains may not be traced. The bones 
 of reptiles and fishes, and the coverings of Crustacea, 
 
12. ORGANIC REMAINS OF THE CHALK. 305 
 
 are in a friable state, and stained with sulphuret of 
 iron. The teeth and scales of the fishes present a 
 high polish, and are coloured by a ferruginous im- 
 pregnation. Wood occurs in the state of lignite, 
 and in brown friable masses, which quickly decom- 
 pose upon exposure to the air, but when enveloped 
 in flint, the structure is well preserved ; like the 
 fossil wood of the tertiary, it has evidently been 
 drifted, and is perforated by teredines ; the fissures 
 are often filled with glittering pyrites. 
 
 In the Gait, the nacreous covering of the shells is 
 commonly preserved, and the ammonites and nautili 
 of Folkstone rival in beauty the shells of the London 
 clay, and, like them .are subject to decomposition. 
 The Green-sand fossils are generally silicified, and 
 the whetstone pits of Devonshire are celebrated for 
 the variety and chalcedonic state of the shells in 
 which the sandstone abounds. 
 
 The organic remains of the chalk formation al- 
 ready known, amount to many hundred species of 
 shells, corals, radiaria, &c. The most distinctive 
 zoological character, is the abundance of belemnites, 
 echinites, and ammonites : the latter are the shells 
 of an extinct race of cephalopoda, which appear 
 for the first time in the chalk, no traces of their 
 remains having been discovered in the tertiary 
 formations. My collection, consisting of many 
 thousand fossils from the chalk formations of Eng- 
 land and America, displays the usual genera and 
 species, together with many that are exceedingly 
 
306 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 rare. I will illustrate this subject by a selection of 
 a few specimens from each class. 
 
 13. FOSSIL VEGETABLES. The flora of the chalk, 
 as I have already remarked, offers but little variety. 
 Fuci, or sea-weeds, occur in some localities in great 
 abundance. There is one species of Fucus (Fucoides 
 Targionii, Tab. 49,) that abounds in the malm rock 
 
 TAB. 49. FOSSIL FUCUS IN MALM ROCK, FROM BIGXOR PARK. 
 
 (Fueoides Targionii.) 
 
 of Western Sussex, particularly at Bignor, the seat 
 of my friend John Hawkins, Esq. F.R. S., where 
 almost every fragment of the rock is marked with its 
 meandering forms. Confervce occasionally are seen 
 in the flints. Plants allied to Zostera occur in the 
 chalk of the Isle d'Aix, and drifted wood abounds 
 in the line of junction between the gait and green 
 sand. In the quarry of Kentish rag, of Mr.W. H. 
 Bensted, of Maidstone, there have been discovered 
 
14. 
 
 ZOOPHYTES OF THE CHALK. 
 
 307 
 
 fir-cones, large masses of perforated wood, and the 
 stem of a plant allied to the yucca. I reserve a 
 more particular description of these remains for the 
 lecture on fossil botany. 
 
 14-. FOSSIL ZOOPHYTES. I have already men- 
 tioned how numerous are the softer zoophytes in 
 
 TAB. 50. CORALS OF THE CHALK. 
 
 Fig. 1 . External surface of Turbinolia Konigi from the gait : the fossil is 
 attached to the marl by the disk, the base lying uppermost and ex- 
 posed. 2. The disk, or iipper surface of Turbinolia Konigi, imbedded in 
 gait. 3. Caryophyllia centralis from the chalk near Lewes. 4. Fungia 
 in limestone, from Maestricht. 5. Gorgonia, from Maestricht. 
 
 the flints. In the white chalk stony corals are 
 found but rarely, while the Maestricht beds contain 
 them in great abundance. A small caryopliyllia 
 
308 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 (Tab. 50, fig. 3) is not unusual in the English white 
 chalk, and a species of turbinolia (Tab. 50, fig. 1, 2) 
 occurs in the gait. I have several unique speci- 
 mens of other genera ; but the absence of the large 
 madrepores and stony corals is a remarkable fact, 
 and accords with the evidence derived from other 
 sources, to prove that we are examining the pro- 
 found abyss of an ocean ; for the economy of the 
 living corals fits them to live only in waters of mode- 
 rate depth. It would be tedious to repeat to you 
 the names which naturalists have assigned to the 
 zoophytes of the chalk ; let it suffice to observe, 
 that the more delicate forms, as flustra, millepora, 
 cellepora, spongia, alcyonium, &c. are very abun- 
 dant, particularly in some localities of the Shanklin 
 sand ; for instance, the quarries at Faringdon, in 
 Berkshire, which literally swarm with polyparia. 
 The nature of these fossils will be explained in a 
 future lecture. There is a zoophyte, well known 
 to collectors of Sussex pebbles by the name of 
 petrified sea-anemone, from its supposed resemblance 
 to the living actinia (PL 6, fig. 8) ; but the original 
 of this fossil was a very different creature. From 
 an extensive suite of specimens, I have ascertained 
 that it was of a subglobular form, with a central 
 opening, from which numerous tubes radiated ; and 
 these are oftentimes exquisitely preserved in flint. 
 The external surface frequently exhibits the remains 
 of crucial spines, similar to those possessed by the 
 recent alcyonia. 
 
15. RADIARIA, CRINOIDEA, &c. 309 
 
 15. RADIARIA, CRINOIDEA, &c. The crinoidea, 
 or lily-shaped animals, are but sparingly distributed 
 in the chalk a circumstance, as you will hereafter 
 
 TAB. 51. MARSUPITE FROM THE CHALK. 
 
 (Restored from specimens pretented me by the Rev. H. Hoper, and 
 G. A. Coombe, Esq. of Arundel.) 
 
 find, strikingly contrasting with the zoological cha- 
 racters of the older secondary formations. Stems 
 of encrinites occur in the chalk and gait ; and there 
 is a small species of apiocrinite, which is peculiar to 
 this formation.* The most remarkable fossil of this 
 class is the marsupite, which I have thus named 
 from its resemblance, when closed, to a purse. The 
 marsupite (Tab. 51) was a molluscous animal, of a 
 * Geology of the South- East of England, p. 111. 
 
310 THE WONDERS OF GEOLOGY. LECT. IV- 
 
 sub-ovate form, having the mouth, which was sur- 
 rounded by arms, or tentacula, in the centre. The 
 skeleton was composed of crustaceous, hexagonal 
 plates, and the arms, which are subdivided into 
 numerous branches, were formed of ossicula, or 
 little bones ; the whole was invested with a mus- 
 cular tissue, or membrane. When floating, the 
 creature could spread out the tentacula like a net, 
 and by closing them, seize its prey and convey it 
 to the mouth. This figure (Tab. 51) is restored 
 from specimens which separately exhibit the parts 
 here represented. 
 
 Asterice, or star-fishy are occasionally found in 
 great perfection in the chalk ; my friend, the Rev. 
 Thomas Cooke, has discovered several remarkably 
 fine impressions in flint, on the South Downs, near 
 Brighton. The whetstone of Devonshire affords 
 similar remains. 
 
 16. ECHINITES. Those remarkable animals, the 
 echini, or sea-urchins, are too well known to re- 
 quire minute description. Their spherical shell, 
 or skeleton, is made up of polygonal plates, closely 
 fitted to each other ; and the surface is divided 
 vertically, by bands like the meridians of a globe, 
 having rows of double perforations. The shell is 
 studded over with papillae, which vary in size, in 
 the different species, from mere granular points to 
 large well-defined tubercles. To these papillae, 
 spines are attached, which also present great variety 
 of figure and decoration. These are the instruments 
 
ECHINITES. 
 
 311 
 
 of motion, and, as on the death of the animal, the 
 tendons by which the spines were fixed to the shell 
 decompose, the extreme rarity of fossil specimens, 
 with these processes in their natural position, is 
 readily explained. The echini, both recent and 
 
 TAB. 52. ECHINITES AKD SPINES FROM THE CHALK. 
 
 Fig. 1. Cidaris diadema. 2, 4, 9. Spines of cidares. 3. Nucleolites. 
 5. Ananchytes cretosus. 6. Tubercle of a cidaris. 7. Spatangus cor- 
 marinum. 8. Spines and portion of the shell of a cidaris in flint. 
 
 fossil, differ greatly in form and structure ; they 
 are arranged into numerous sub-genera, for the 
 convenience of study, but I can notice only a few 
 of the usual varieties. 
 
 The helmet-shaped echinites (fig. 5) are ex- 
 tremely abundant, and in some localities occur in 
 
312 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 shoals, and in every gradation from the young to 
 the adult state. Silicious casts of echini, formed 
 by the decomposition and removal of the shell from 
 the flint with which they were filled, are common 
 in gravel and on ploughed lands. The cordiform 
 variety (fig. 7) is very abundant, and gives rise to 
 the heart-shaped flints of our gravel-pits. The 
 elliptical species (fig. 3) is common in the green 
 sand. The hemispherical echini are beautifully 
 embossed with papillae : a small species (fig. 1) is 
 not uncommon in the chalk and flints of Kent; 
 the larger varieties possess tubercles, surrounded by 
 elegant margins (fig. 6), and are otherwise richly 
 ornamented. Some spines are slender, and covered 
 with asperities (fig. 2); others almost smooth (fig. 9), 
 and club-shaped (fig. 4); it is seldom that the 
 spines are found imbedded in contact with the 
 shell (fig. 8). 
 
 17. SHELLS OF THE CHALK. The bivalve shells, 
 or conchifera of the chalk, are very numerous ; of 
 one genus alone (terebratula) above fifty species 
 are enumerated. Oysters, scallops, areas, tellens, 
 and other familiar marine shells abound, but the 
 species differ from the recent. With these known 
 genera are many which, so far as our present know- 
 ledge of the inhabitants of the deep extends, are 
 extinct. Two or three species of cirrus, or trochus, 
 are not unusual in the white chalk ; but the simple 
 univalves are few ; and the only specimen of a large 
 simple spiral univalve with which I am acquainted 
 
17. 
 
 SHELLS OF THE CHALK. 
 
 313 
 
 is a species of dolium, figured by Sowerby.* The 
 Maastricht beds, as I have before remarked, offer 
 many exceptions to the usual fossils of the chalk. 
 A large volute ( V. Faujasii) is found in the flint 
 
 TAB. 53. SHELLS OF THE CHALK. 
 
 Fig. 1. Inoceramus concentricus. 2. Turrilites costatus. 3. Inoceramus 
 sulcatus. 4. Inoceramus Lamarckii. 5. Belemnites Listen. 6. Ha- 
 mites. 7. Ammonites Mantellii. 8. Plagiostoma spinosum. 9. Am- 
 monites Sussexiensiu. 
 
 nodules of St. Peter's Mountain, with baculites, am- 
 monites, and other characteristic chalk fossils. In 
 the marl at Ramsey, near Lewes, I have discovered a 
 * Mineral Conchology, vol. v. Tab. 426. 
 
314 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 few genera of simple univalves not previously known 
 in the chalk. The sub-globular terebratulae, both 
 the common and the striated varieties, are very 
 abundant. Another bivalve equally numerous is an 
 elegant shell, having one valve covered with long 
 spines (Tab. 53, fig. 8), the Plagiostoma spinosum,* 
 a characteristic species of this formation. A bivalve 
 having a fibrous structure, (Inoceramus, Tab. 53, 
 fig. 4,) very brittle, with a crenulated hinge of a 
 peculiar construction, presents numerous species ; 
 some of which are small and delicately striated, and 
 others two feet in diameter, and deeply furrowed. 
 The substance of these shells closely resembles in 
 structure that of the recent pinnce ; from their 
 fragility, fragments are very common in chalk, flint, 
 and even in pyrites. The Gait contains two species 
 of this genus, which appear to be restricted to this 
 division of the chalk, and have been found in almost 
 every locality ; they are the Inoceramus concentricus 
 (Tab. 53, fig. 1,) and I. sulcatus (Tab. 53, fig. 3) ; 
 a hybrid occurs in the Folkstone beds, partaking of 
 the characters of both. I have discovered a species 
 of spherulite (S. Morfoni) in the chalk near Lewes, 
 in Sussex ; but hippurites, so common in the cre- 
 taceous strata of the continent, have not been 
 noticed. 
 
 * Plagiostoma. Viscount D'Archiac informs me that the 
 shells of this genus are true spondyli, and that the triangular 
 vacancy in the lower valve is occasioned by the loss of that por- 
 tion of the hinge which characterises the recent spondylus. 
 
18. CEPHALOPODA, AND CHAMBERED SHELLS. 315 
 
 The shells of the green sand amount to many 
 hundred species : those of the whetstone pits of 
 Blackdown, in Devonshire, are changed either into 
 silex, jasper, or chalcedony.* 
 
 18. CEPHALOPODA, AND CHAMBERED SHELLS. 
 The most peculiar and striking feature of the organic 
 remains of the chalk, as contrasted with those of the 
 tertiary and modern deposits, is the vast preponder- 
 ance of multilocular cephalopoda. In the tertiary, 
 and in the existing tropical seas, one genus (the 
 nautilus) occurs abundantly. The beauty, elegant 
 form, and remarkable internal structure of the 
 recent shell, have rendered it in all ages an object 
 of admiration ; yet an accurate knowledge of the 
 nature and structure of the animal to which it 
 belonged has but recently been obtained. Dr. 
 Buckland has given a lucid account both of the 
 recent and fossil cephalopoda ; -f- my remarks. on 
 this subject will therefore be very concise. 
 
 The sepia, or cuttle-fish of our seas, is of an 
 oblong form, composed of a jelly-like substance, 
 covered with a tough skin ; the mouth, which is 
 central, is furnished with horny mandibles, much 
 resembling the beak of a parrot. The animal has 
 two large eyes, and eight arms, studded with rows 
 of little cups, or suckers, which are powerful instru- 
 ments both of locomotion and prehension. The 
 
 * Dr. Fitton's Memoir on the Shanklin sands contains repre- 
 sentations of the usual shells and zoophytes of those strata, 
 t Bridgewater Essay, p. 333, et seg. 
 
316 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 soft body of the sepia is supported by a skeleton 
 formed of a single bone of very extraordinary struc- 
 ture ; when dried and reduced to powder it is the 
 substance called pounce. The cuttle-fish has the 
 power of secreting a dark-coloured fluid, or ink, 
 which it ejects when pursued, and by thus rendering 
 the water turbid, escapes from its enemies. This 
 fluid is contained in a bag, and forms, when pro- 
 perly prepared, the sepia colour employed in the 
 arts, and enters into the composition of Indian ink. 
 This brief sketch of the natural history of the 
 cuttle-fish, will enable us to understand the habits 
 and economy of the beings whose fossil remains I 
 am about to describe. 
 
 19. THE BELEMNITE. One of the most common 
 fossils of the chalk is an elongated conical stone, of 
 a crystalline, radiated structure, and generally of a 
 brown colour, called belemnite. The pits in Sussex, 
 Kent, Norfolk, and indeed every locality of the 
 chalk, contain these bodies ; and some limestones on 
 the continent are almost wholly composed of them. 
 The belemnite presents considerable variety of form, 
 but in every species the structure consists of a 
 spathose radiated substance, terminating in a point, 
 (Tab. 54, fig. 2,) and having at the opposite and 
 largest end a conical cavity, in which was situated 
 a shell of like form, divided into septa or chambers, 
 as seen in the drawing (Tab. 54, fig. 1) : this shell 
 is commonly wanting in the specimens found in the 
 chalk. Dr. Buckland has admirably explained the 
 
20. 
 
 THE NAUTILUS. 
 
 317 
 
 nature of the belemnite, and given the solution of a 
 problem which had long been attempted in vain. 
 The belemnite is the bone of a creature allied to 
 the cuttle-fish, and in this representation (Tab. 54, 
 fig. 1,) its situation in the body of the animal, and 
 connexion with the ink-bag, are so clearly shown, 
 
 TAB. 54. BELEMNITE AND NAUTILUS. 
 
 Fig. 1. Section of a restored Belemno-sepia, from Dr. Buckland ; a, the 
 ink-bag; b, the belemnite. 2. Belemnites Listeri. 3. Section of the 
 shell, with the animal, of the recent nautilus, from Professor Owen's 
 Memoir ; a, the animal in the outer chamber. 
 
 as to require no further comment. The belemnite 
 sometimes occurs with the laminated, external, 
 horny sheath, the conical, chambered shell, the 
 ink-bag, and the fibro-calcareous bone, in their 
 natural position ; the inspissated contents of the 
 bag, the fossil sepia, has actually been employed as 
 a pigment by one of our most eminent artists. 
 
 20. THE NAUTILUS. The shell of the nautilus 
 consists internally of a series of chambers, which 
 
318 THE WONDERS OF GEOLOGY. LECT. IV 
 
 are pierced through the middle by a siphunculus 
 or tube, which extends to the remotest cell. The 
 animal is of the nature of the sepia, and occupies 
 the outer receptacle of the shell ; it maintains a 
 connexion with the inner chambers by means of a 
 membranous tube which lines the siphuncle. The 
 chambers are internal air-cells, and the creature has 
 the power of filling the siphuncle only, with a fluid 
 secreted for the purpose, and of exhausting it ; the 
 difference thus effected in the specific gravity of the 
 animal and its shell enables the nautilus to sink or 
 swim at pleasure. If, therefore, you imagine a 
 cuttle-fish placed in the outer chamber of a nau- 
 tilus, with its arms extended, and having a tube 
 connected with the siphunculus, but neither ink-bag 
 nor bone, these being unnecessary to an animal 
 having the protection and mechanism of a cham- 
 bered shell, you will have a tolerably correct idea 
 of the recent nautilus. The nautilus is essentially 
 a ground-dwelling animal, feeding on the marine 
 plants which grow at the bottom of the sea. ** Rum- 
 phius states that it creeps with the shell above, and 
 that by means of its tentacula it can make quick 
 progress along the ground."* 
 
 21. THE AMMONITE, OR CORNU AMMONIS. 
 
 The fossils called ammonites, like the belemnites, 
 also first appear in the secondary formations ; or 
 more properly, no traces of their remains have been 
 found in the tertiary deposits. The ammonite, so 
 * Dr. Buckland's Essay. 
 
21. THE AMMONITE, OR CORNU AMMONIS. 319 
 
 called from its supposed resemblance to the horn of 
 Jupiter Ammon, is a fossil chambered shell, coiled 
 up in the form of a disk, bearing a close analogy to 
 the nautilus, but differing in the situation of the 
 siphuriculus, and in the septa by which the interior 
 is divided. In the nautilus these partitions are 
 entire, and their section presents a series of simple 
 curves, (Tab. 54, fig. 3 ;) but in the ammonite they 
 possess every variety of sinuosity, and the external 
 surface of the casts of the ammonites commonly 
 exhibits markings resembling the outlines of deeply 
 fringed foliage; the shell is also generally decorated 
 with flutings, ribs, or tubercles. The siphuncle, or 
 syphon, which in the nautilus is central, is placed 
 at the back of the ammonite. I have placed before 
 you specimens from the Gait of Folkstone, in which 
 the shell remains, from Watchett, with the internal 
 nacreous coat only, while in this common species 
 from \\hitby the shell is altogether wanting, the 
 specimen being a cast of the interior, formed of 
 argillaceous iron-stone, a state in which these fossils 
 are frequently found. In some examples, the shells 
 and partitions of the chambers having decomposed, 
 casts of the cells have been formed, which fit 
 into each other, and admit of being put together, 
 so as to show the entire shape of the ammonite. 
 Nautili also occur in this state ; and in a spe- 
 cimen, for which I am indebted to Miss Pearson, 
 of Clapham, the series is complete from the com- 
 mencement to the outer cell. Nearly three hundred 
 
320 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 kinds of ammonites are known in the secondary 
 formations, certain forms being restricted to par- 
 ticular rocks. Thus, for example, the chalk marl of 
 Sussex abounds in two species, (Tab. 53, figs. 7, 9,) 
 which either are very rare, or do not occur in the 
 white chalk above, or in the gait below; and in 
 every locality of the marl in England, and on the 
 continent, these species are found. But I must 
 again refer you to Dr. Buckland's Bridgewater 
 Essay for much important and interesting informa- 
 tion on these subjects. I will add but one remark ; 
 the membranous tube of the siphuncle sometimes 
 occurs in a fossil state; as may be seen in this 
 ammonite from the chalk-marl near Lewes, which 
 retains a large portion of the siphuncle ; the black 
 substance of these tubes has been analysed, and 
 found to consist of animal membrane, permeated 
 by carbonate of lime. Dr. Prout is of opinion that 
 the black colour has originated from decomposition ; 
 the oxygen and hydrogen of the animal membrane 
 having escaped, and carbon been evolved, as happens 
 when vegetable matter is converted into coal, under 
 the process of mineralization. The lime has taken 
 the place of the oxygen and hydrogen, which ex- 
 isted in the pipe before decomposition.* 
 
 Ammonites vary in size from a few lines to twelve 
 
 or fourteen feet in circumference ; at low water on 
 
 those parts of the Sussex coast where the chalk 
 
 forms the base of the shore, enormous specimens 
 
 * Bridgewater Essay, p. 352. 
 
23. TURRILITES. 321 
 
 are often seen imbedded. In some limestone dis- 
 tricts, the marble is almost wholly composed of 
 ammonites, as in this polished slab from Somerset- 
 shire, which is adorned with most beautiful and 
 varied sections of the inclosed shells. 
 
 22. TURRILITE, HAMITE, &c. Baculitcs, turri- 
 lites, hamites, and other genera of nmltilocular 
 shells, abound in the chalk marl, gait, and Shanklin 
 sand. The turrilite (Tab. 53, fig. 2), may be de- 
 scribed as an ammonite twisted in a spiral, instead 
 of a discoidal form : and the hamite (Tab. 53, fig. 6), 
 as a similar structure in the shape of a hook, coiled 
 up at the smaller extremity. These shells some- 
 times attain a large size ; the turrilite before you, 
 which is the finest example known, would if perfect 
 exceed two feet in length ; it possesses traces of 
 the siphuncle. Hamites of gigantic proportions 
 have been found in the Shanklin sand of Kent, by 
 Mr. Hills, the intelligent and indefatigable curator 
 of the Chichester Museum. The first specimens of 
 turrilites, hamites, and scaphites, from the British 
 strata, were discovered in my early researches, in 
 Hamsey marl-pits, near Lewes.* The scaphite is 
 of a boat-like form ; but I must forbear entering 
 on its description, as well as on that of many other 
 multilocular shells, hundreds of which are micro- 
 scopic, and sometimes form entire layers in the 
 chalk. 
 
 23. SPIROLINITES. There is however one genus 
 * Sowerby's Mineral Conchology, vol. i. Tab. 18. 
 
 y 
 
 
322 
 
 THE WOJJDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 which I cannot pass over without remark ; it is 
 called, from the disposition of its chambers, the 
 spirolinite, and resembles the common nautilus 
 spirula, the crozier-shell of collectors, except that 
 the coils, which in the recent shell are separate, 
 are in this fossil in close apposition. Several species 
 
 TAB. 55. SPIROLINITES IN FLINT. 
 (By the Marquit of Northampton, P.R.S.) 
 
 Fig. 1. Spirolinites Lyellii. Fig. 2. S. Murchisom. 
 
 previously unknown in the chalk, were discovered 
 by the Marquis of Northampton, P.R.S. some years 
 since, in the pebbles on the Brighton shores ; and 
 
23. 
 
 SPIROLINITES. 
 
 323 
 
 in flints from the chalk at Kemp-town, and other 
 places : these minute but most interesting objects 
 having escaped the notice of less accurate and in- 
 telligent observers. My son also has collected 
 
 
 TAB. 56. SPIROLINITES IN FLINTS. 
 (By the Marquis of Northampton, P.R.S. $c.) 
 
 Fig. 1. Spirolinites Stokesii. 2. S. Mantellii. 3. S. Lyellii. 
 4. S. Comptoni. 
 
 several specimens from the chalk and flints near 
 Chichester. I have great pleasure in laying before 
 you enlarged drawings, by his lordship, of four 
 
 Y2 
 
324 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 species ; the smaller figures indicate the size of the 
 originals.* 
 
 24. INFUSORIA IN FLINT. Among the almost 
 endless diversity of forms in which those atoms of 
 
 * Note on the Sussex spirolinites, by the Marquis of North- 
 ampton : 
 
 " I willingly comply with your desire to communicate a short 
 note on the Sussex spirolinites, one species of which you have 
 been pleased to distinguish by my name. I have found these fossils 
 in flint at Brighton, Kemp-town, Rottingdean, Lewes, Hastings, 
 Steyning, Chichester, West Stoke, and in the Isle of Wight ; 
 and one specimen in France. I have discovered about two 
 hundred of these minute chambered shells in flint, but only two 
 in chalk. Some of the microscopic bodies extricated from the 
 chalk by Mr. Lonsdale, I am inclined to think are spirolinites, 
 but others are foraminifera. I have seen, as I believe, minute 
 nummulites in the Sussex flint. The spirolinites which I have 
 collected constitute four distinct species. 1. The one to which 
 you have been pleased to give the appellation of S. Comptoni. 
 2. Spirolinites Lyellii, distinguished by the horizontal chambers, 
 one above the other, in the coiled portion. 3. S. Stokesii, which 
 I name after our friend Charles Stokes, Esq. ; and this name 
 has the further advantage of pointing out the locality, West 
 Stoke, near Chichester, from which I obtained this unique 
 specimen, and where other spirolinites abound. The fourth 
 vou must allow me to designate S. MantelliL The distinctive 
 characters of these species are too obvious to require detailed 
 description. The transverse chambers in S. Lyellii (Tab. 55, 
 fig. 1, and Tab. 56, fig. 3,) are a striking peculiarity of structure ; 
 in the specimen from France (Tab. 55, fig. 1), there appear 
 indications of a siphuncle in the straight prolongation. I am 
 inclined to believe that there are other species in my collection, 
 but the irregularity in the fractured sections of these minute 
 chambered shells, renders it difficult to arrive at accurate con- 
 clusions on this point. 
 
 " Castle Ashby, January 1, 1838." " NORTHAMPTON." 
 
24. INFUSORIA IN FLINT. 325 
 
 animal existence, the infusoria (so called because 
 numerous species abound in vegetable infusions) 
 appear, many, like the cypris of which we have 
 already spoken, possess shields or coverings, some 
 of which are ferruginous, others calcareous, and 
 many silicious ; the yellow film seen on the surface 
 of stagnant water is made up of these animals. 
 The infusoria belong to many distinct families, some 
 having a complex organization, with a nervous, 
 muscular, and circulating system, and digestive 
 organs highly developed. As I shall revert to this 
 subject in another lecture, I now only wish to call 
 your attention to the remarkable fact, that the sili- 
 cious cases, or skeletons, of this class of beings, 
 have been discovered in a fossil state ; and that 
 some deposits, for instance the tripoli of Bilin in 
 Bohemia, consist almost entirely of the silicified 
 remains of infusoria, of a species so minute, that a 
 cubic inch of stone, weighing 220 grains, contains 
 upwards of 41 thousand millions of these skeletons.* 
 The distinguished naturalist, Ehrenberg, to whom 
 we are indebted for this wonderful discovery, has 
 also detected the remains of these animalculae in 
 chalk-flints, semi-opal, and other silicious substances; 
 and the Rev. I. B. Reade, of Peckham,f has observed 
 in the flints of Surrey, shields of gaillonella, a form 
 of infusorial animal well known to microscopic 
 
 * See a translation of Ehrenberg's Observations on these 
 discoveries, in Taylor's Scientific Memoirs, Part III. 
 f Appendix H. 
 
320 THE WONDFRS OF GEOLOGY. LECT. IV. 
 
 observers. I shall hereafter place before you repre- 
 sentations of several of these objects ; it is sufficient 
 for the present to have stated the fact, that entire 
 masses of flint are composed of the fossilized remains 
 of beings, as wonderful in their structure and or- 
 ganization, as any of the colossal forms of animal 
 existence.* Some kinds of opal appear to have 
 been formed of the dissolved silicious skeletons of 
 these animalcules, and the more durable forms are 
 seen preserved in it like insects in amber. -j- 
 
 25. CRUSTACEA OF THE CHALK. Species of 
 several genera of Crustacea have been obtained from 
 the Sussex chalk; in some examples I have suc- 
 ceeded in removing the surrounding stone, and 
 exposing the filiform antennae, the abdominal seg- 
 ments, and the tails of astacida. In the gait, the 
 Crustacea hitherto discovered belong to very small 
 species. I have obtained from Ringmer, near 
 Lewes, specimens which, in the opinion of Dr. Leach, 
 are extinct forms, related to Indian genera. In the 
 Speeton clay of Yorkshire, Professor Phillips has 
 discovered several beautiful species of astacus.J 
 The Shanklin sands of Kent and Dorsetshire have 
 
 * The vegetable kingdom presents us with forms equally 
 minute. The red colour occasionally observable in the snow 
 at Baffin's Bay, is occasioned by a species of fungus (urcdo 
 nivalis), a full grown individual of which is but l-1600th of an 
 inch in diameter ; each square inch of the snow is therefore 
 covered by two millions five hundred thousand fungi. Batter. 
 
 t LyelFs Elements of Geology. 
 
 J Astacus, cray-fish. 
 
26. CRUSTACEA OP THE CHALK. 327 
 
 yielded a few crustacean remains. In the limestone 
 of St. Peter's Mountain, claws of a small kind of 
 crab are frequently discovered (Tab. 57), but no 
 
 TAB. 57. CLAWS OP A CRAB IN LIMESTOXE, FROM MAESTRICHT. 
 (Pagurui Faujatii.J 
 
 other vestiges of the animal. Faujas St. Fond, and 
 Latreille, have very ingeniously explained this fact, 
 by showing that the claws belonged to a parasitical 
 species, which like the common hermit-crab of our 
 seas, had the body covered by a delicate membrane, 
 the claws alone having a shelly casej hence the 
 latter would be found in a fossil state, while of the 
 other parts of the animal no traces would remain. 
 
 26. FISHES OF THE CHALK SHARKS. The 
 fossil fishes of the chalk were known only by the 
 teeth, which abound in almost every quarry, until 
 my researches in the chalk-pits around Lewes 
 
328 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 brought to light the extraordinary specimens before 
 you, and showed how such delicate remains could 
 be developed. The teeth for the most part belong 
 to fishes allied to the shark; a family which in the 
 ancient, as in the modern seas, appears to have 
 been confined by no geographical limits. Professor 
 Agassiz, by whose genius and perseverance this de- 
 partment of palaeontology has been so successfully 
 elucidated, has proposed a classification of fishes, 
 founded upon the peculiar structure of the scales 
 an arrangement of great utility to the geologist, 
 since the mutilated state in which ichthyolites so 
 frequently occur, render futile the attempt to place 
 them in the existing orders and genera.* 
 
 The teeth of sharks, particularly those of the 
 genus lamna (Tab. 58, figs. 2,4), are very common 
 in the chalk, and occur occasionally in the flint; 
 they possess a high polish, are in an excellent state 
 of preservation, and are always single, arising from 
 the cartilaginous nature of the jaws of the original. 
 These examples of the recent shark show the number 
 and variety of the teeth in an individual ; by the 
 decomposition of the jaw the teeth would be sepa- 
 rated and drifted by the water, and therefore, in a 
 fossil state, seldom exhibit any traces of their ori- 
 ginal position. It may, however, happen, that jaws 
 with teeth will hereafter be discovered, for vertebrae, 
 fin-bones, and even the shagreen skin of sharks, are 
 preserved in some specimens in my collection. The 
 * See Appendix I. ; and Dr. Buckland's Essay, p. 268. 
 
20. FISHES OF THE CHALK. 329 
 
 broad rugous teeth (fig. 6) are sometimes found in 
 groups of twenty or thirty ; they belong to a fish 
 allied to the shark, in which the mouth was covered 
 
 TAB. 58. TEETH OF FISHES ALLIED TO THE SHARK, FROM THE 
 SUSSEX CHALK. 
 
 Fig. 1. Notidanus microdon. 2. Lamna Mantellii. 3. Galeus pristo- 
 dontus. 4. Lamna appendiculata. 5. Ptychodus altior. 6. Ptychodus 
 decurrens. 
 
 with these bony processes, like a tessellated pave- 
 ment. The spines, fin-bones, or rays of fishes, also 
 occur in the chalk ; and I have one splendid spe- 
 cimen, in which even the tendinous expansion of 
 
330 THE WONDERS OF GEOLOGY. LECT. IV- 
 
 the muscle that moved the fin-bone is preserved.* 
 Some of those in .my cabinet belong to the same 
 genus as the dog-fish of our coast (spinax acan- 
 thias), which has a curved spine in front of the 
 dorsal fin ; I place before you a recent and fossil 
 spine, to show their analogy. The mandible, or 
 
 TAE. 59. MANDIBLE OF A SPECIES OF CHIMERA, FROM THE CHALK 
 NEAR LEWES. 
 
 (One-half the natural size.) 
 
 jaw-bone, of a very curious fish (the chimera) was 
 one of my earliest discoveries in Hamsey marl-pit, 
 and I have since found examples in the chalk of 
 Lewes ; other species have been discovered in the 
 green sand of Kent, by Mr. Bensted, and in the 
 Kimmeridge clay, by Sir Philip Egerton.-f- 
 
 The remains of large fishes, belonging to that 
 division called by Agassiz, sauroid, from their com- 
 
 * Fossils of the South Downs, Tab. xxxix. 
 
 f The nature of these curious relics remained unknown, till 
 Dr. Buckland ascertained that they are the mandibles of several 
 extinct species of chimera. 
 
27. FOSSIL SALMON, OR SMELT. 331 
 
 bining in their structure certain characters of rep- 
 tiles, have been found in the chalk and green sand 
 of Sussex and Kent. They consist of large, conical, 
 striated teeth, bearing a resemblance to those of 
 crocodiles, with which they were formerly con- 
 founded. I have several from the white chalk near 
 Lewes ; Mr. Bensted has discovered others in the 
 Kentish rag, and Mr. Rose, in the gait of Cam- 
 bridge. 
 
 27. FOSSIL SALMON, OR SMELT. But the most 
 remarkable ichthyolites of the chalk, are the fishes 
 belonging to the salmon family (salmonidce), and 
 closely related to the smelt (osmerus). Many years 
 since, I succeeded in extricating from the chalk the 
 extraordinary specimen before you.* 
 
 The length of the fish is nine inches, and it 
 stands nearly six inches in relief; the back is still 
 attached to the chalk, and the dorsal fin is exposed. 
 There are other examples of the same species in my 
 cabinet, which are almost equally perfect. These 
 ichthyolites were obtained from the quarries in the 
 immediate vicinity of Lewes, during my residence 
 in that town. It is clear that the chalk must have 
 surrounded the fishes while they were alive and in 
 actual progression, and by suddenly consolidating, 
 preserved their forms unaltered ; for the body is 
 round and uncompressed, the mouth open, and the 
 
 * A beautiful lithograph of this fossil, by Mr. Pollard, 
 forms the frontispiece of the Catalogue of the ManteUian 
 Museum. 
 
332 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 fins and gills are expanded. Even to those whose 
 curiosity has not previously been awakened to geo- 
 logical inquiries, the examination of these petrified 
 inhabitants of the ocean cannot fail to excite deep 
 interest ; and I have seen the man of fashion, as 
 well as the philosopher, gaze in mute astonishment 
 on these " relics of a former world." 
 
 28. MACROPOMA, AND OTHER FISHES. I have 
 already mentioned that the capsule of the eye re- 
 mains in many specimens ; this is particularly the 
 case with those fishes (beryx} which have some re- 
 semblance to the dory (Tabs. 63, 64). In a sauroid 
 fish, named macropoma by M. Agassiz, the mem- 
 branes of the stomach are invariably preserved ; 
 this fish (Tab. 61), independently of the fact just 
 stated, is extremely remarkable in its organization. 
 The operculum of the gills is very large, and the 
 scales are studded with hollow tubes. In many 
 recent fishes, there is a row of tubular scales, 
 forming what is called the lateral line, through 
 which flows a fluid that lubricates the surface of 
 the body; in the macropoma, every scale appears 
 to have possessed such a mechanism. 
 
 Many of the most interesting chalk ichthyolites 
 in my museum are figured by M. Agassiz, in his 
 important and splendid work " Recherches sur 
 les Poissons Fossiles" I now place before you 
 restored figures of seven species ; for comparative 
 anatomy enables us not only to reconstruct the 
 colossal mammalia, and the palaeotheria, but also to 
 
28. 
 
 FOSSIL FISHES FROM LEWES. 
 
 333 
 
 TAB. 60. Fig. 1. OSMEROIDES MANTELLII. Length 12 inches. From 
 
 Lewes Chalk-pits. 
 Fig. 2. ACROGNATHUS Boops. Natural size. Unique. From Lewes. 
 
334 
 
 THE WONDERS OF GEOLOGY. LECT. IV 
 
 TAB. 61. Fig. 1. AULOLEPIS TYPUS. Length 6 inches. Unique. From 
 Clayton Chalk-pit. Fig. 2. MACROPOMA MANTELLII. Length 24 
 inches. From the chalk quarries near Lewes. 
 
28. 
 
 FOSSIL FISH FROM LEWES. 
 
 335 
 
 TAB. 62. DEB.CETIS ELONGATUS. Length 16 inches. From Lewes. 
 
 This species occurs abundantly in the chalk at Preston, near Brighton. 
 The outline represents the skeleton, from a specimen in my museum ; 
 the only instance in which the skull remains. 
 
336 
 
 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 TAB. 63. BERYX RADIANS. Length 7 inches. From the chalk-marl, 
 near Lewes. 
 
 This species is generally found in the chalk-marl : specimens have been 
 collected at Clayton, Steyning, and Arundel, in Sussex. 
 
23. 
 
 FOSSIL FISH FROM LEWES. 
 
 337 
 
 TAB. 64. BERYX LEWESIEXSIS. Length 12 inches. From Lewes 
 chalk-quarries. 
 
 This is the most abundant of the Sussex ichthyolites ; and is called 
 Johnny Dory by the workmen. Detached scales are very frequent in the 
 chalk of the South Downs, and also in that of Kent and Surrey. Some 
 line specimens of this species have recently been found in the chalk of 
 Chatham and Maidstone. 
 
338 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 restore, with all the lineaments of life, the fishes 
 which lived and died in the seas of the ancient 
 world. These restorations have been drawn with 
 great care by an eminent artist, M. Dinkel, of 
 Munich. 
 
 The fossil fishes discovered in the South Downs 
 amount to upwards of forty species ; and there are 
 several undescribed from the chalk of Kent, in the 
 splendid collections of ichthyolites of Viscount Cole 
 and Sir P. M. Egerton, Bart. 
 
 In the other sub-divisions of this formation, both 
 in England and elsewhere, the remains of fishes 
 occur. The slates of Glaris, in Switzerland, have 
 long been celebrated for their ichthyolites, and 
 by these fossils M. Agassiz was enabled to de- 
 termine that those strata belong to the chalk ; 
 although the schist in which they are imbedded, 
 as may be seen in this fine suite of specimens 
 (collected and presented to me by the distin- 
 guished geologists above named), is a compact 
 bituminous slate, scarcely to be distinguished from 
 some of the most ancient of the transition series ; 
 a character which is attributable to the effects 
 of high temperature, as will hereafter be ex- 
 plained. 
 
 In concluding this cursory review of the fossil 
 fishes of the chalk, it must be remarked that all 
 these ichthyolites are of extinct forms; and that 
 none of the species, and even but few of the genera, 
 occur in more recent deposits j a result in perfect 
 
29. REPTILES OF THE CHALK. 339 
 
 accordance with that derived from the examination 
 of the zoophytes and mollusca.* 
 
 29. REPTILES. The remains of reptiles hitherto 
 observed in the chalk are but few ; the most im- 
 portant is the Moscesaurus ffoffmanni, of which 
 I spoke when describing the Maestricht deposits. 
 The occurrence of the vertebrae of a reptile be- 
 longing to the same genus, if not species, in the 
 Lewes chalk, and of similar teeth and bones in 
 the equivalents of this formation in North America, 
 are facts of great interest. Through the kindness 
 of Mr. Charlesworth, I have inspected portions of 
 a large jaw with teeth from the Norfolk chalk, 
 which bear a resemblance to those of the mosae- 
 saurus; but the symmetrical, conical form of the 
 teeth, and other characters, show that they belong 
 either to an unknown reptile, or to a sauroid fish. 
 Bones of turtles are found in the white chalk of 
 Sussex, and abundantly in the limestone of St. 
 Peter's Mountain, and in the slate of Glaris ; they 
 belong to marine species. I have a mandible of a 
 turtle from the Lewes chalk, which is figured by 
 Dr. Buckland ; f and a femur from Kent, dis- 
 covered by Mr. Bensted. Teeth of crocodiles, 
 from the chalk of Meudon, are mentioned by 
 Cuvier ; and very recently a specimen containing 
 the vertebral column, ribs, and pelvis of a small 
 lizard, in a beautiful state of preservation, was 
 
 * See Appendix K. 
 
 t Bridgevvater Essay, Plate 44, fig. 3. 
 
 z2 
 
340 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 found in a chalk-pit near Chatham, and is in the 
 possession of Sir P. M. Egerton. 
 
 30. REVIEW OF THE CHALK FORMATION. The 
 characters of the chalk formation, as shown by 
 these investigations, are those of a vast oceanic 
 basin, filled with the debris thrown down by its 
 waters, and which enveloped the remains of its in- 
 habitants ; arenaceous beds prevailing in the lower- 
 most argillaceous in the middle and cretaceous 
 in the upper division of the series. Intrusions of 
 thermal streams appear to have been abundant at 
 certain periods ; and the proofs are incontrovertible, 
 that throughout the entire epoch of its formation, 
 its waters swarmed with living beings of the various 
 orders of marine existence; all, or almost all, the 
 species being now extinct. The fuel show that it 
 possessed a marine vegetation ; and the drifted 
 wood, fir-cones, stems, and leaves, that its shores 
 were bounded by dry land clothed with forests ; 
 the fossil reptiles also aiford additional confirmation 
 of this inference. 
 
 31. GEOLOGY OF THE SOUTH-EAST OF ENG- 
 LAND. From this survey of the marine formation 
 of the chalk, we turn to the remarkable fluviatile 
 deposits, of which the basin of the cretaceous ocean, 
 in the south-east of England, was composed ; in 
 other countries, as I shall again have occasion to 
 remark, that basin was formed of the oolite and 
 other marine strata. It will now be necessarv to 
 offer a few observations on the geology of the 
 
31. GEOLOGY OF THE SOUTH-EAST OF ENGLAND. 341 
 
 district in which the beds of the wealden are so 
 largely developed. 
 
 The strata of the south-east of England con- 
 stitute three principal groups. The first consists 
 of the tertiary sands, clays, and gravel, described 
 in the previous lecture, which occupy depressions 
 of the chalk. The second is the chalk, (including 
 under this term the white chalk, gait, and green 
 sands,) which forms the most striking feature in 
 the physical geography of the country. The upper 
 division of the cretaceous formation constitutes the 
 South Downs, which from the bold promontory of 
 Beachy-head, traverse the county of Sussex from 
 east to west, and pass by Hampshire into Surrey. 
 From Godalming the chalk hills extend by Godstone 
 into Kent, where the range is called the North 
 Downs, and terminate in the cliffs of Dover. The 
 lowermost member of the chalk, the Shanklin sand, 
 appears as a chain of hills of very irregular elevation, 
 which skirts the escarpments of the chalk downs, 
 the gait constituting a valley between them. The 
 third group is spread over the area between the 
 North and South Downs ; the most elevated masses 
 forming a range called the Forest-ridge, which 
 traverses the district in a direction nearly east and 
 west, and is composed of alternations of sandstone, 
 sands, shales, and clays, with a deep valley on each 
 Hank, called the weald; hence the geological de- 
 signation of the whole series. From the central 
 ridge of the wealden, which varies in height from 
 
 
342 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 400 to 800 feet, the strata diverge on each side 
 towards the Downs, forming an anticlinal axis y and 
 finally disappear beneath the lowermost beds of the 
 chalk. ( Vide the section, PL 9, fig. 1.) There are 
 conclusive proofs that the wealden strata were ori- 
 ginally covered by the chalk, and that their present 
 position and appearance are attributable to changes 
 which have taken place subsequently to the creta- 
 ceous epoch ; the wealden having been lifted up 
 and forced through the chalk, and thus effected the 
 partial destruction of that formation.* 
 
 32. GEOLOGICAL PHENOMENA BETWEEN LON- 
 DON AND BRIGHTON. The direct roads from 
 London to Brighton pass over the whole series of 
 deposits comprised in the above sketch, as well as 
 those described in the first lecture. Proceeding 
 from the Thames, the observer successively tra- 
 verses the modern silt of the river the ancient 
 alluvium, containing remains of elephants and other 
 large mammalia and if he proceed by Reigate, his 
 road, at Clapham and Tooting, lies over beds of clay 
 and gravel, which are part of the ancient shores 
 of the London basin. At Suttoii he ascends the 
 chalk hills of Surrey, and travels along elevated 
 masses of the ancient ocean-bed just described. 
 Arriving at the precipitous southern escarpment 
 of the North Downs, a magnificent landscape, dis- 
 playing the physical structure of the weald, and 
 its varied and picturesque scenery, suddenly bursts 
 
 * See Geology of the South-East of England, chap. xi. 
 
32. GEOLOGICAL PHENOMENA NEAR REIGATE. 343 
 
 upon his view. At his feet lies the deep valley of 
 gait in which Reigate is situated, and immediately 
 beyond the town appears the elevated ridge of 
 Shanklin sand, which stretching towards the west, 
 attains at Leith-hill an altitude of one thousand feet; 
 and to the east forms a line of sand-hills, by God- 
 stone and Sevenoaks, through Kent, to the sea-shore. 
 The Forest-ridge occupies the middle region, ex- 
 tending westward towards Horsham, and eastward 
 to Crowborough-hill, its greatest altitude, and from 
 thence to Hastings, having on each flank the wealds 
 of Kent and Sussex ; while in the remote distance, 
 the unbroken and undulated summits of the South 
 Downs appear like masses of grey clouds on the 
 verge of the horizon. 
 
 Pursuing his route, the observer passes through 
 Reigate, along the valley of gait, (see Plate 9, Sec- 
 tion I. 2,) and over the Shanklin sands of Cockshut- 
 hill, (3,) and arrives at the commencement of the 
 wealden.* The weald clay, (4,) containing beds of 
 fresh-water limestone, appears at Horley common ; 
 and while in the commencement of his journey the 
 roads were made of broken chalk- flints, and at Rei- 
 gate of cherty sandstone, the material here chiefly 
 employed is the bluish-grey calcareous rock of the 
 weald. At Crawley, (5,) sand and sandstone appear, 
 and the road is composed of grit and stone, con- 
 taining fluviatile shells, bones and plants. Crossing 
 
 * The reader will be able to follow this route by referring to 
 the section, PL 9, fig. 1. 
 
344 THE WONDERS OP GEOLOGY. LECT. IV. 
 
 Tilgate Forest and Handcross, over a succession 
 of elevated ridges of sandstone, and through clay 
 valleys, produced by alternations in the strata, he 
 descends from the sandstone ridge at Bolney, near 
 Cuckfield, and again journeys along a district of 
 weald clay with fresh-water limestone (4-, on the left). 
 Shanklin sand, like that of Reigate, reappears at 
 Hickstead (3, on the left), and is succeeded by a 
 tract of gait (2, on the left) ; and finally, entering a 
 vale of chalk-marl, he reaches a defile in the South 
 Downs, through which the road winds its way to 
 Brighton ; the traveller having in the course of his 
 journey passed from one chalk range to the other, 
 and traversed the ancient delta of the wealden. 
 
 33. THE WEALDEN. The tertiary basin of 
 London afforded an illustration of the process by 
 which materials are accumulated and organic re- 
 mains imbedded, in an inland sea, that of Paris, 
 of marine and fresh-water sediments, deposited in 
 a gulf open to the sea on the one side, and fed by 
 rivers and thermal springs on the other, the lacus- 
 trine formations of Auvergne, of the gradual pre- 
 cipitation of strata in the tranquil waters of lakes, 
 the chalk, of the operations which have taken place 
 in the profound abyss of an ocean, while the 
 series of deposits to which the term wealden is 
 applied, presents the most striking example of an 
 ancient fluviatile formation hitherto discovered. 
 Yet strange as it may appear, although the wealden 
 strata are spread over the whole area between the 
 
33. THE WEALDEN. 345 
 
 North and South Downs, a tract of country tra- 
 versed daily by hundreds of intelligent persons from 
 the metropolis, their peculiar characters were en- 
 tirely unknown fifteen years ago ;* the whole group 
 being supposed by geologists to belong to a series 
 of marine clays and sands below the chalk. -j- 
 
 Before entering upon the description of these 
 strata, I would remind you of what has been stated 
 in a previous lecture, of the effects of rivers, and 
 the nature of modern fluviatile deposits (pp. 39, 40). 
 We found the deltas of rivers to consist of clay (or 
 indurated mud), alternating with beds of sand and 
 sandstone (or consolidated sand), and containing 
 leaves, branches, and trunks of trees, fresh-water 
 shells, works of art, bones of man, and of land 
 
 * " Until the appearance of Dr. Mantell's works on the 
 Geology of Sussex, the peculiar relations of the sandstones 
 and clays of the interior of Kent, Sussex, and Hampshire, were 
 entirely misunderstood. No one supposed that these immense 
 strata were altogether of a peculiar type, and interpolated amid 
 the rest of the marine formations, as a local fresh- water deposit, 
 of which only very faint traces can be perceived in other parts of 
 England." Professor Phillips, Ency. Met. p. 631. Art. Geology. 
 
 11 It was not until the appearance of Dr. Mantell's Illus- 
 trations of the Geology of Sussex, in 1822, that the full value 
 of the evidence which this district affords was made to appear. 
 In that work the author clearly showed that the extraordinary 
 remains which he had discovered in the beds of Tilgate Forest 
 must have originated in a lake, or estuary, and have been the 
 produce of a climate much warmer than that which is now en- 
 joyed in England." Dr. Fitton's Geology of Hastings, p. 14. 
 
 f See Conybeare and Phillips' Outlines of the Geology of 
 England and Wales, pp. 140, 155. 
 
346 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 animals, more or less rolled, with boulders formed 
 of fragments of rocks, transported by torrents from 
 the hills, or washed out of the banks by the 
 streams. Let us now suppose that by agencies 
 already explained, a river has disappeared, that the 
 sea also has changed its place, and that the bed and 
 the delta of the river have become dry land ; that 
 towns and villages have been built upon the con- 
 solidated delta, and that its surface is either clothed 
 with woods and forests, or under cultivation. If 
 sections of the strata were exposed, either by 
 natural or artificial means, and the bones of men 
 and animals, with works of art, and remains of 
 plants and shells, were visible in the clay or sand- 
 stone, such appearances would excite in us no 
 surprise, because we are acquainted with the pro- 
 cesses by which such accumulations are formed. 
 Should an inhabitant of the new country express 
 his wonder how brittle shells, delicate leaves, and 
 bones, had become imbedded in the solid rock, 
 and if when we stated the manner in which those 
 changes had been effected, he should not only refuse 
 his assent, but insist that the shells, leaves, and 
 bones, were merely accidental forms of the stone, 
 should we not feel astonished at his ignorance' and 
 prejudice? yet not a century since, and such an 
 opinion almost universally prevailed, and is even 
 still entertained by many ! * And farther, if our 
 
 * "At Hawkhurst, in the weald of Kent, these stones (Sussex 
 marble) abound. They consist of several laminae, between 
 
34. WEALDEN OF THE SUSSEX COAST. 347 
 
 assumed personage admitted that the remains in 
 question were fossil animals and vegetables, but 
 asserted that they had been entombed in the strata 
 by a general deluge which had softened the crust 
 of the earth, and engulfed in the sediment of its 
 waters the remains of animated nature, should we 
 not reply, that as such a catastrophe must inevitably 
 have mingled together the remains of animals and 
 vegetables, whether of the land, the rivers, or the 
 seas the regular stratification of the materials 
 composing the delta, and the exclusive occurrence 
 of land and fresh- water productions, were fatal 
 to such a supposition, and afforded conclusive evi- 
 dence of the correctness of our explanation of the 
 phenomena ? by such a train of reasoning the 
 fluviatile nature of the wealden has been deter- 
 mined. 
 
 34. WEALDEN OF THE SUSSEX COAST. From 
 the distribution of the wealden over the south-east 
 of England, instructive sections have been formed 
 by the action of the sea along the coast, between 
 Beachy Head and Dover. From the stupendous 
 cliffs of Beachy Head the chalk extends towards 
 Southbourn, where beds of gait, giauconite, marl, 
 
 which grow shells, or rather half-shells, having the appearance 
 of periwinkles of different magnitudes, according to the time of 
 their growth. These stones naturally grow in the earth, and 
 the shells upon them, and are another certain proof that shells 
 are generated in the earth, as well as in the sea, and that there is 
 no necessary connexion between a shell and an animal." (! !) 
 Natural History of England, p. 193, vol. i. 1759. 
 
348 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 and Shanklin-sand, successively emerge, forming 
 the base of the shore, and abounding in their cha- 
 racteristic marine fossils. Passing over Pevensey 
 Levels, the boundary of which, on the sea-side, is 
 obscured by modern shingle, we arrive at Bexhill 
 and Bulverhithe, and find the cliffs composed of 
 finely laminated sandstone and clays ; and those 
 of St. Leonard, of similar strata, more extensively 
 developed : sands and clays separated into very 
 thin laminae, alternate with conglomerates, indu- 
 rated sand-rock, and a fine sandstone, of great 
 compactness, called grit. At Hastings, sand and 
 clay, with interspersions of lignite, laminated shale, 
 grit, and sandstone, constitute a long line of high 
 cliifs.* The general resemblance of these strata 
 to fluviatile accumulations is most striking ; the 
 laminated structure of the clay and shales, the 
 constant intermixture of minute portions of lignite, 
 the absence of pebbles and shingle, and the alter- 
 nations of mud and sand, are lithological characters 
 constantly observable in river deposits. To the 
 west of Hastings a fine mass of the strata, com- 
 prising several layers of the calciferous grit, alter- 
 nating with friable sandstone, was formerly exposed 
 on the sea shore, having at a very remote period 
 
 * See an excellent little volume on these cliffs, " A Guide to 
 the Geology of Hastings," by W. H. Fitton, Esq. M.D. F.R.S. &c. 
 "The Geology of the South-east of England" contains a map, 
 sections, and full details of the geological structure of this in- 
 teresting district. 
 
35. 
 
 VALE OF POUNCEFORD. 
 
 349 
 
 been separated from the adjacent cliff. The action 
 of the waves had bleached the projecting layers of 
 grit, from which circumstance the mass obtained 
 the name of " White rock.'' The late improvements 
 
 TAB. 65. WHITE BOCK, HASTINGS. 
 (Drawn by Miss Jane Allnutt ) 
 
 a, Inland cliff of laminated sandstone and clay ; b, Cliff to the east of 
 Hastings. The White rock is marked by the flag on its summit ; it is 
 composed of calciferous grit. 
 
 at St. Leonard's have removed all traces of this 
 outlying portion of the Hastings beds.* The nature 
 of the organic remains with which the strata abound 
 will be considered hereafter. 
 
 35. POUNCEFORD. In the interior of the country, 
 
 the quarries opened along the ridges formed by the 
 
 compact grit, afford various instructive sections; and 
 
 the valleys, eroded by the streams, expose the shales 
 
 * Geology of the South-East of England, p. 194. 
 
350 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 and laminated clays. Pounceford, on the estate of 
 Lord Ashburnham, on the road to Burwash, in 
 Sussex, presents several highly interesting sections 
 of the argillaceous beds and limestones. Descend- 
 ing through a defile in the sandstones, we arrive at 
 the bottom of a glen, along which a rapid stream, 
 that bursts out from between the clay-partings, 
 rushes to a distant and lower valley. On each side 
 openings are made, to arrive at a greyish blue lime- 
 stone abounding in shells, which is employed on the 
 roads, and is also converted into lime for agricultural 
 purposes. Where the stone lies deep, shafts are 
 sunk from the surface, and after the extraction of 
 the limestone, they are deserted and filled up. This 
 
 TAB. GG K CLAY WITH SHELLS, FROM POUNCEFORD, SUSSEX. 
 a, Melanopsis attenuata; b, Cyclas media; c, Cyclas membranacea. 
 
 spot is highly interesting and picturesque ; incrust- 
 ing springs issue from the limestone beds, and de- 
 posit tufa on the mosses, equiseta, and land-shells : 
 
35. TILGATE FOREST. 351 
 
 thousands of fossil shells are strewn over the clay 
 and shale ; and stems of plants, scales of fishes, 
 teeth of crocodiles, and other remains, are seen 
 imbedded in the stone; while the banks, where 
 newly exposed, exhibit numberless laminae and 
 alternations of shale, clay, and layers of testaceous 
 remains.* In a visit to this place with my friend 
 Mr. Lyell, in 1831, many new species of shells were 
 found in the bed of the stream, having been washed 
 out of the banks of clay ; and we collected teeth of 
 crocodiles, and bones of fresh-water turtles, and of 
 other reptiles. Several species of cyclas (a fresh- 
 water bivalve shell), and a spiral univalve, were 
 abundant in the clay (Tab. 66) ; and a muscle, 
 (named Mytilus Lyellii, to commemorate our ex- 
 cursion, Tab. 77, fig. 8,) also a fluviatile species, 
 was found in a mass of shale that had fallen into the 
 rivulet. 
 
 As the grit, or calciferous sandstone of the 
 wealden, forms an excellent road-material, the 
 quarries along the principal lines leading from the 
 metropolis to the south-eastern coast, are very nume- 
 rous ; and those spread over the area of Tilgate 
 and St. Leonard's Forests have been extensively 
 worked since the increased communication between 
 London and Brighton. This district may be de- 
 scribed as bounded on the west by the London 
 roads leading through Horsham, and on the east 
 
 * See Fossils of Tilgate Forest, p. 47. Geology of the South- 
 East of England, p. 22. 
 
352 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 by those which pass by Linfield, and Cuckfield; the 
 Crawley road, as previously mentioned, traversing 
 Tilgate Forest. These localities, particularly that 
 of Tilgate, have acquired much celebrity for their 
 organic remains, from having been the principal 
 sources whence" the specimens figured in my first 
 work on the " Fossils of Tilgate Forest,"* were 
 derived ; but every quarry throughout the Forest- 
 range, from Loxwood in western Sussex, to Has- 
 tings, will be found to yield the peculiar fossils of 
 the wealden more or less abundantly. 
 
 36. SUBDIVISION AND EXTENT OF THE WEALDEN. 
 The wealden may be divided into several groups, 
 each characterised by the nature of the strata, and 
 the prevalence of certain kinds of fossils; but 
 throughout the whole series, the fluviatile character 
 of the formation is maintained : in the lowermost 
 part of the series only are there any intrusions of 
 a marine or estuary nature. Although it is not 
 within the scope of these lectures to enter upon 
 minute details of stratification, it will be necessary, 
 for the elucidation of the subject, to point out the 
 principal subdivisions of this extensive system of 
 fresh-water deposits. -j- 
 
 1. WEALD CLAY (the uppermost or latest deposit}. Stiff blue 
 clay, with septaria, argillaceous ironstone, and beds of shelly 
 limestone, called Sussex or Petworth marble. (See the sec- 
 tion PL 9, fig. I. 4.) 
 
 * See Fossils of Tilgate Forest, p. 51. 
 
 f Geology of the South-East of England, p. 182. 
 
36. SUBDIVISIONS OF THE WEALDEN. ,].",;} 
 
 2. HASTINGS BEDS. Sand and sandstones, with calciferous grit, 
 or Tilgate- stone, alternating with clays and limestones. 
 
 o. ASHBURNHAM BEDS. Clays, shales, and bluish-grey lime- 
 stones and sandstones. 
 
 4. PURBECK BEDS Clays, sandstones, and shelly limestone, 
 called Purbeck marble. Limestone, with layers of vegetable 
 mould, and trunks of trees in a vertical position the petri- 
 fied Forest of Portland. 
 
 Such is the assemblage of deposits which the 
 term wealden, first employed in this acceptation by 
 Mr. Martin,* is intended to denote. Clays, and 
 limestone almost wholly composed of fresh-water 
 snail-shells, occupy the uppermost place in the 
 series ; sand and sandstones, with shales and lignite, 
 prevail in the middle ; while in the lowermost, 
 argillaceous beds, with shelly marbles or limestones, 
 again appear ; and, buried beneath the whole, is a 
 petrified forest, in which the trees are still standing, 
 and the vegetable mould undisturbed ! The upper 
 clay-beds and marbles form the deep valleys or 
 wealds of Kent and Sussex the middle series con- 
 stitutes the forest-ridge. The Purbeck are ob- 
 scurely seen in some of the deepest valleys of 
 eastern Sussex; they emerge on the Dorsetshire 
 coast, form the island or peninsula whose name they 
 bear, and surmount the northern brow of the Isle 
 of Portland. At the back of the Isle of Wight, 
 the wealden beds appear beneath the Shanklin 
 sands ; and their characteristic fossils are conti- 
 nually washed up on the shore at Brook-point* 
 
 * Martin's Geology of Western Sussex. 
 A A 
 
354 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 Dr. Fitton* has traced the wealden beds, or rather 
 the lowermost division, the Purbeck, in the vale of 
 Wardour, which is a valley of denudation, in the 
 south of Wiltshire, like that of the South-east of 
 England, on a small scale. In this valley the vari- 
 ous members of the chalk occur in their regular 
 order of superposition, resting on clay and Purbeck 
 limestone, and having the Portland stone beneath. -f- 
 In France, on the coast of the Lower Boulonnais, 
 and in the valley of Bray near Beauvais, strata of 
 a like character are observable ; the Sussex marble 
 (lumachelle-a-paludines}) and a fern peculiar to the 
 wealden, have been discovered by M. Graves of 
 Beauvais, to whom I am indebted for specimens. 
 It is probable that the wealden may have extended 
 over a still larger area, for the same fossil plant 
 (lonchopteris Mantellii, Tab. 73) has been found in 
 strata beneath the green-sand, in Sweden, by Pro- 
 fessor Nillson, who informed me that several of 
 the fossil plants from Tilgate Forest were analo- 
 gous to specimens he had collected in the little 
 island of Bornholm, off the Danish coast. Without 
 implicitly relying upon these observations, the 
 wealden may be considered as covering an area 
 200 miles in length from west to east, and 220 
 miles from north-west to south-east ; an extent but 
 little exceeding the delta of the Ganges or of the 
 
 Consult Dr. Fitton's Memoir " On the Beds below the 
 Chalk;" Geological Transactions, 1837. 
 f Ibid. p. 424. 
 
37. QUARRIES OF TILGATE FOREST. 355 
 
 Mississippi, and surpassed by that of the Quorra, 
 which forms a surface of 25,000 square miles, being 
 equal to the half of England. The total thickness 
 of the wealden deposits averages about 2000 feet.* 
 37. QUARRIES OF TILGATE FOREST. The quar- 
 ries of Tilgate Forest, where the calciferous grit is 
 worked, present the following series of strata : 
 
 1. Uppermost. Loam or clay from one, to five or six feet in 
 depth. Destitute of fossils. 
 
 2. Sandstone friable, of various shades of fawn, yellow, and 
 ferruginous colour ; in laminae, or thin layers, occasionally 
 containing organic remains and pebbles, eight feet thick. 
 
 3. Calciferous grit, or Tilgale stone a very fine sandstone, 
 formed of sand cemented together by calcareous spar ; it 
 occurs in large masses of a concretional form, imbedded in 
 soft sandstone. This grit has evidently been formed of 
 loose sand, by the percolation of water charged with calca- 
 reous matter ; it abounds in bones and teeth of reptiles ; 
 stems and leaves of plants ; shells, &c. 
 
 4. Sandstone, with concretionary masses of grit and conglo- 
 merate formed of rolled pebbles of sandstone, jasper, 
 quartz, indurated clay, bones and teeth of reptiles, and of 
 fishes ; rolled masses of the grit and sandstone are found in 
 this conglomerate; the organic remains which it contains 
 are generally much water-worn. 
 
 5. Blue clay and marl depth unknown. 
 
 Such is the usual character of the strata exposed 
 
 in the quarries around Bolney, Cuckfield, Linfield, 
 
 &c. Near Horsham the fawn-coloured sandstone 
 
 is more compact, and possesses a slaty structure. 
 
 The thin slates are used for roofing, and the thicker 
 
 beds afford good paving-stone ; their surfaces are 
 
 * Dr. Fitton. 
 
 A A 2 
 
35f> THE WONDERS OF GEOLOGY. LECT. IV. 
 
 sometimes deeply furrowed by ripple-marks an ap- 
 pearance on which I will offer a few observations. 
 
 38. RIPPLE-MARKS ON SANDSTONE. The fur- 
 rowed sandstone and grit which are used for paving 
 in Horsham, Crawley, and other towns and villages 
 on the Forest-ridge and Tilgate Forest, must have 
 attracted the attention of most persons who have 
 travelled from Brighton to London. The surface 
 of these slabs is similar to what may be observed 
 on the sand along the sea-shore at low water r 
 when the ripple from the receding waves has been 
 well marked ; the appearance has arisen from a 
 similar cause (see p. 43). In many instances the 
 stone is so rough as to be employed in stable-yards, 
 where an uneven surface is required to prevent the 
 feet of animals from slipping in passing over. It 
 sometimes happens that when a large area of a 
 quarry is cleared from the soil which covers it, a 
 most interesting appearance is presented, the whole 
 surface being rippled over like the strand on the 
 sea-shore ; and the spectator is struck with the con- 
 viction that he is standing on the sands of some 
 ancient delta or estuary, which are now turned into 
 stone. Sometimes the furrows are deep, showing 
 that the water was much agitated, and the ripple 
 strong ; in other instances the undulations are 
 gentle, and intersected by cross ripples, proving a 
 change in the direction of the waves. Some slabs 
 are covered by slightly elevated, longitudinal ridges 
 of sand, made up of gentle risings, disposed in a 
 
38. RIPPLE-MARKS OX SANDSTONE. 3J7 
 
 crescent-like manner ; these have been produced 
 by the rills which flow back into the sea, or river, 
 at low water. In other examples, the surface is 
 marked by angular ridges irregularly crossing each 
 other, like the fissures in septaria ; these have obvi- 
 ously been caused by deposition into crevices pro- 
 duced in sand or mud by desiccation. A considerable 
 portion of stone, the smooth, as well as the furrowed 
 surfaces, is covered with small, subcylindrical mark- 
 ings, which are the trails formed by some species 
 of vermes, or mollusca ; but I have searched in 
 vain for the foot-marks of the reptiles whose bones 
 are so abundant in the sandstone. The frequent 
 occurrence of impressions of the feet of animals in 
 the rippled sandstone of other formations, renders 
 it probable that sooner or later the tracks of the 
 iguanodon and of the hylaeosaurus will be discovered 
 on the Tilgate sandstone. The deepest furrows have 
 generally a slight coating of bluish clay, charged 
 with minute portions of lignite, and other vegetable 
 matter ; an appearance which has been occasioned 
 by the streams from the shore that have flowed over 
 and coated the rippled sand. The furrowed sand- 
 stone presents an interesting example of the perfect 
 similarity of a natural process in periods separated 
 from each other by an immense interval of time.* 
 
 * For a particular account of the Wealden strata in the 
 south-east of England, see " Geology of the South-East of 
 England ;" and the " Fossils of Tilgate Forest" For their 
 nature and distribution in Wilts, &c. see Dr. Fitton's Memoir. 
 
358 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 39. WEALDEN OF THE ISLE OF WIGHT. De- 
 posits partaking of the characters of those I have 
 described, appear at the back of the Isle of Wight, 
 and form the lowermost strata throughout the 
 southern half of the island. Clay, identical with 
 the weald clay, and containing Sussex marble, may 
 be seen at Sandover bay, within a few hundred 
 yards of the chalk, and extending into Red-cliff; 
 and also at the junction, on the east of Fresh-water 
 bay, where the clay abounds in the minute shields 
 
 Shalcomb Down. 
 
 Compton Grange. 
 Brook-point. a s 
 
 TAB. 67. SECTION PKOM BROOK-POINT TO SHALCOMB DOWN, 
 ISLE OF WIGHT.* 
 
 1, 1, Hastings sand, a, Lignite and fossil trunks of trees. 2. Weald clay. 
 3. Shanklin sand. 4. Gait. 5. Chalk marl. 6. Chalk. 
 
 of cyprides. At Brook-point, the cliffs, which are 
 about thirty feet high, are formed of clay, with 
 inferior beds of soft sandstone ; they contain lignite, 
 and vegetable remains strongly impregnated with 
 pyrites. Trunks of trees, of a coaly blackness, are 
 seen imbedded in the clay of the cliff, (Tab. 67, ,) 
 and scattered on the shore. In many of the stems 
 Dr. Fitton. Geological Transactions, vol. iv. PI. 10. 
 
40. ISLE OF PURBECK. 359 
 
 the ligneous structure is beautifully preserved, and 
 veined with pyrites other portions resemble jet. 
 The strand at low water is seen to be formed of 
 these fossils ; and upon removing the sea-weeds 
 which grow on the shore, the petrified trees occur 
 imbedded in masses of clay, which have become 
 indurated, and are now in the state of an argilla- 
 ceous rock : the stems are from one to two feet in 
 diameter, and eight or ten feet long. The knotty 
 bark and ligneous fibre are very distinct.* Bones 
 of the iguanodon and other gigantic reptiles are 
 frequently found on the shore at Sandover-bay and 
 Brook-point, being washed out of the beds of the 
 wealden, which there form part of the basin of the 
 British Channel. 
 
 40. ISLE OF PURBECK. The wealden beds are 
 next seen in the Isle of Purbeck, which lies on the 
 Dorsetshire coast, and is of an irregular oval form, 
 being twelve miles in length, and seven in breadth. 
 On the eastern promontory, vertical strata of chalk 
 occur, and beds of clay, sandstone, and limestone 
 lie under the displaced chalk ; towards the southern 
 extremity of the island, the Portland limestone 
 appears.-f- 
 
 Purbeck has long been celebrated for its quar- 
 ries, which have been worked from time imme- 
 morial, and particularly during the middle ages, the 
 
 * From Mr. Webster's interesting account of the Geology of 
 the Isle of Wight. 
 
 f Conybeare and Phillips. 
 
360 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 compact varieties of limestone, which bear a good 
 polish, having, under the name of Purbeck marble, 
 been in great request for the religious edifices of 
 that period ; and there is scarcely a cathedral, or 
 ancient church in the kingdom, that is not orna- 
 mented with columns, pavements, or sepulchral 
 monuments, constructed of this material. The 
 Purbeck limestone abounds in organic remains ; 
 and the marble is a congeries of small fresh-water 
 snail-shells (paludina), intermixed with the minute 
 crustaceous coverings of a species of cypris. How 
 interesting is the reflection, that the beautiful cluster- 
 columns, the richest ornaments of Chichester cathe- 
 dral, are entirely composed of the shelly coverings 
 of snails and Crustacea which lived in the river of a 
 country inhabited by extinct colossal reptiles ! 
 
 TAB. 68. SECTION IN ONE OF THE COVES ON THE WEST OF THE 
 ISLE OF PURBECK. 
 
 a, Chalk; b, Chalk-marl; c, Firestone; d, Gait; e, Shanklin sand; 
 /, Purbeck beds ; g, Portland stone. 
 
 The vertical position into which so considerable 
 a portion of the strata has been thrown, gives rise 
 to interesting sections in the coves on the western 
 
41. PETRIFIED FOREST OF THE ISLE OF PORTLAND. 361 
 
 side of the island ; and, in the precipitous cliffs of 
 those basins, the chalk, weald, Purbeck, and Port- 
 land strata, although vertical, may be seen in their 
 regular order of succession, as is shown in this 
 diagram (Tab. 68). No fewer than nine sections 
 of the beds between the chalk and Portland stone 
 (the upper division of the oolite, of which I shall 
 speak in the next lecture) are visible within the 
 space of five miles, in the small bays by which the 
 coast is indented.* 
 
 41. PETRIFIED FOREST OF THE ISLE OF PORT- 
 LAND. The island, or peninsula, of Portland is a 
 bold headland, off Weymouth, about four miles and 
 a half in length, and two in breadth, and is united 
 to the main land by the Chesil beach. It presents a 
 precipitous escarpment on the north, and declining 
 towards the south, appears, on approaching it from 
 the Dorchester coast, like an inclined plane, rising 
 abruptly from the ocean. The southern extremity 
 is flanked by low calcareous cliffs, which, from the 
 constant action of the sea, are worn into hollows 
 and caverns. The base of the island is formed of 
 a blue clay (Kimmeridge clay), surmounted by 
 thick beds of the oolitic limestone, known as the 
 Portland stone, and which is extensively quarried 
 on the northern brow of the island. 
 
 On this oolitic limestone are fresh-water strata 
 (the lowermost beds of the wealden formation), 
 
 * Dr. Fitton, p. 215. See Conybeare and Phillips' Geology 
 of England, p. 159. 
 
362 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 which are characterised by phenomena of the 
 highest interest. Mr. Webster, in his admirable 
 geological memoir on the Isle of Wight, first di- 
 rected attention to these remarkable deposits. Upon 
 
 Vegetable soil. 
 
 Freshwater lime- 
 stone. 
 
 Clay. 
 
 Freshwater lime- 
 stone. 
 
 DIRT-BED, with 
 fossil trees and 
 Mantellte. 
 
 Freshwater lime- 
 stone. 
 
 DIRT-BED, with 
 
 Mantellite. 
 
 Portland oolite; 
 a marine lime- 
 stone. 
 
 Base of the 
 
 quarry. 
 
 
 Total thickness about thirty feet. 
 
 TAB. 69. SECTIOX OF A QUARRY IN THE ISLE OF PORTLAND. 
 (From Dr. Fitton's Memoir on the Strata below the Chalk.) 
 
 the upper layer of marine limestone (Tab. 69, 8), 
 which abounds in ammonites, trigoniae, and other 
 characteristic shells of the oolite, is a fresh-water 
 limesto ne, covered by a layer of bituminous earth, 
 
41. ISLE OF PORTLAND PETRIFIED FOREST. 363 
 
 or vegetable mould (4), which (as you may perceive 
 from these specimens, collected a few years since,) 
 is of a dark brown colour, contains a large propor- 
 tion of earthy lignite, and, like the modern soil on 
 the surface of the island, many water-worn stones. 
 This layer is termed the dirt-bed by the workmen ; 
 and in and upon it are trunks and branches of coni- 
 ferous trees, and plants allied to the recent cycas 
 and zamia. Many of the trees, as well as the plants, 
 are still erect, as if petrified while growing undis- 
 turbed in their native forests, having their roots in 
 the soil, and their trunks extending into the upper 
 limestone (see Tab. 69, 4). As the Portland stone 
 lies beneath these strata, which are not much used 
 for economical purposes, the fossil trees are re- 
 moved, and thrown by as rubbish. On my visit to 
 the island in the summer of 1832, the surface of a 
 large area of the dirt-bed was cleared, preparatory 
 to its removal, and a most striking phenomenon was 
 presented to my view. The floor of the quarry 
 was literally strewn with fossil wood ; and I saw 
 before me a petrified, tropical forest, the trees 
 and the plants, like the inhabitants of the city in 
 Arabian story, being converted into stone, yet still 
 maintaining the places which they occupied when 
 alive I Some of the trunks were surrounded by 
 a conical mound of calcareous matter, which had 
 evidently once been earth, and had accumulated 
 around the bases and roots of the trees. The stems 
 were generally three or four feet high, their summits 
 
361 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 being jagged and splintered, as if they had been 
 torn and wrenched off by a hurricane, an appear- 
 ance which many trees in this neighbourhood, after 
 the late storm, strikingly resembled. Some of the 
 trunks were two feet in diameter ; and the united 
 fragments of one tree measured upwards of thirty 
 feet in length ; in other specimens, branches were 
 attached to the stem. In the dirt-bed, there were 
 many trunks lying prostrate, and fragments of 
 branches. The fossil plants are called Cycadeoidea 
 by Dr. Buckland, from their analogy to the recent 
 cycas and zamia;* but M. Adolphe Brongniart 
 has established a new genus for their reception, 
 which he has named Mantellia. The plants oc- 
 curred in the intervals between the trees ; and the 
 dirt-bed was so little consolidated, that I dug up 
 with a spade, as from a parterre, several specimens 
 that were standing on the very spot in which they 
 grew, having, like the columns of Puzzuoli (Tab. 
 14), preserved their erect position amidst all the 
 revolutions which had subsequently taken place, 
 and beneath the accumulated spoils of number- 
 less ages. The trees and plants are completely 
 petrified by silex, or flint : you perceive that 
 
 * These plants are so common in green-houses, that their 
 forms must be well known. In the conservatories of the Coli- 
 seum, in the Regent's Park, are fine examples of the dracaena, 
 yucca, cycas, and several species of palms, allied to the fossil 
 plants of Tilgate Forest. The magnificent collection of palms 
 of the Messrs. Loddige, of Hackney, is alluded to in my work 
 on the Fossils of Tilgate Forest. 
 
41. 
 
 ISLE OF PORTLAND-PETRIFIED FOREST. 
 
 3G5 
 
 sparks are emitted upon striking a piece of steel 
 with this fragment of what was once a delicate 
 plant; the common forms of the fossil cycadece, 
 
 
 TAB. 70. SILICIFIED TRUNK OK MANTELLIA NIDIFORMIS. 
 
 (Cycadites megalophyllus, Dr.Buckland.*) 
 
 One-fourth the natural size. 
 
 a, Central mass of cellular tissue ; b, Circle of radiating woody plates ; 
 c, Circle of cellular tissue ; d, The case, or false bark. 
 
 {Mantellia nidiformis of Brongniart, Tab. 70), are 
 
 called crows nests by the quarry-men. Our limits 
 
 will not admit of a more extended notice of these 
 
 * Dr. Buckland's Bridgewater Essay, PI. 60. 
 
366 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 extraordinary phenomena, and I refer you to the 
 memoirs of Mr. Webster, Dr. Fitton, and Dr. Buck- 
 land. From what has been stated, it is evident, 
 that after the marine strata forming the base of the 
 Isle of Portland were deposited at the bottom of a 
 deep sea, and had become consolidated, the bed of 
 that ocean was elevated above the level of the 
 waters, became dry land, and covered with forests. 
 How long this new country existed, cannot be 
 ascertained ; but that it flourished for a considerable 
 period is certain, from the number and magnitude 
 of the trees of the petrified forest. In the Isle of 
 Purbeck, traces of the dirt-bed, with the trunks of 
 trees, are seen beneath the fresh-water limestones 
 
 TAB. 71. SECTION OF THE CLIFF EAST OF LULWORTH COVE.* 
 
 1, Purbeck calcareous slate; 2, Dirt-bed, with trunks of trees; 3, Marine 
 limestone of Portland. 
 
 of the weald ; a proof, that before the deposition 
 of the Purbeck marble could have taken place, the 
 
 * Dr. Buckland. 
 
} 42. MODERN SUBMERGED FOREST. 367 
 
 petrified forest must have sunk to the depth of many 
 hundred feet. A highly interesting section occurs 
 on the east of Lulworth Cove (Tab. 71). It pre- 
 sents a portion of the dirt-bed, with petrified trunks 
 of coniferous trees, standing in the black mould in 
 which they grew (2), interposed between the fresh- 
 water Purbeck slate above (1), and the marine Port- 
 land limestone below (3) ; the whole of the strata 
 being in an inclined position.* 
 
 42. MODERN SUBMERGED FOREST. An inter- 
 esting modern example of the subsidence of a con- 
 siderable tract of country clothed with forests, the 
 trees remaining erect, although submerged beneath 
 a river which still flows over them, is described by 
 a late American writer, and will serve to illustrate 
 the preceding remarks. The whole district, from 
 the Rocky Mountains on the east and the Pacific 
 Ocean on the west, and from Queen Charlotte's 
 Island on the north to California on the south, 
 presents one vast tract of volcanic formation. 
 Basalt, both columnar and in amorphous masses, 
 veins and dykes, every where occurs, and craters of 
 extinct volcanoes are still visible. Elevations and 
 dislocations of the strata have taken place on an im- 
 mense scale ; and successive beds of basalt, amyg- 
 daloidal trap, and breccia, prove the alternation of 
 igneous action and periods of repose. Within a few 
 miles of the cascades of the river Columbia, and 
 extending upwards of twenty miles, trees are seen 
 * Bridgewater Essay, vol. ii. p. 97. 
 
368 THE WONDERS OF GEOLOGY. LECT, IV' 
 
 standing in their natural position, in a depth of 
 water from twenty to thirty feet. The trees reach 
 to high, or fresh-water mark, which is fifteen feet 
 above the lowest level of the tide ; but they do not 
 project beyond the freshet rise, above which their 
 tops are decayed and gone. In many places the 
 trees are so numerous, that u we had to pick our 
 way with the canoe, as through a forest. The water 
 of the river was so clear, that the position of the 
 trees could be distinctly seen down to their spreading 
 roots, and they are standing as in their natural state 
 before the country had become submerged. Their 
 undisturbed position proves that the subsidence must 
 have taken place in a tranquil mariner." * 
 
 43. FOSSILS OF THE WEALDEN. The organic 
 remains of the wealden consist of leaves, stems and 
 branches of plants of a tropical character ; bones of 
 enormous reptiles of extinct genera, of crocodiles, 
 turtles, flying reptiles, and birds ; of fishes of several 
 genera and species; and fluviatile shells and crus- 
 tacea. The bones are, for the most part, broken 
 and rolled, as if they had been transported from a 
 distance. They are strongly impregnated with iron, 
 and are commonly of a dark-brown colour ; their 
 cavities are frequently filled with white crystallized 
 carbonate of lime. The bones in the loose sand 
 and sandstone are often porous and friable ; those 
 in the Tilgate grit are heavy, brittle, and well 
 
 * Journal of an Exploring Tour beyond the Rocky Moun- 
 tains," by the Rev. Samuel Parker, A. M. New York. 1838. 
 
44. FOSSIL VEGETABLES OF THE WEALDEN. 369 
 
 preserved ; in fractured portions imbedded in the 
 limestone, the interstices are filled with calcareous 
 spar, and the cancellated structure of the bones is 
 often permeated by the same substance. The fossil 
 vegetables occur bituminized, and in the state of 
 casts of sandstone ; the stems and branches are 
 sometimes silicified ; carbonized leaves and twigs 
 are abundant in some of the strata. The shells in 
 the clays have undergone but little change, and in 
 many examples, the epidermis still remains ; in the 
 limestone, the substance of the shell is converted 
 into spathose carbonate of lime. With these general 
 remarks, I pass on to the enumeration of the prin- 
 cipal organic remains. 
 
 44?. FOSSIL VEGETABLES FERNS. From the 
 abundance of the carbonaceous remains of vege- 
 tables in many of the laminated shales and clays 
 of the wealden, and the occurrence of lignite, or 
 brown-coal, in masses and layers, which sometimes 
 alternate with beds of stone abounding in fresh- 
 water bivalves, a striking analogy is presented to 
 some of the divisions of the coal measures ; and 
 many years since, this resemblance gave rise to a 
 search for coal at Bexhill, which, of course, proved 
 abortive.* But notwithstanding the prevalence of 
 vegetable matter in the strata, specimens exhibiting 
 the nature of the original plants, in any tolerable 
 degree of preservation, are rare ; and, although my 
 
 * Geology of the South-East of England, p. xviii. Fossils 
 of the South Downs, p. 35. 
 
 B B 
 
370 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 researches have been unremitting, I have obtained 
 but few fossil plants that will admit of satisfactory 
 conclusions as to their original structure. I shall 
 restrict my present remarks to a brief account of 
 the principal varieties, and the circumstances under 
 which they occur. 
 
 Entire layers of the calciferous grit of Tilgate 
 Forest are so full of minute portions of carbonaceous 
 
 TAB. 72. SPHENOPTERIS MANTELLU. TII.GATE TOHEST. 
 (A fossil fern peculiar to the wealden.) 
 
 matter,* as to acquire a dark mottled colour ; and 
 upon examining the imbedded particles, they appear 
 
 * Fossils of Tilgate Forest, Plate 3, fig. 6. 
 
44. 
 
 FOSSIL FERNS OF THE WEALDEN. 
 
 371 
 
 to be the detritus of plants ground to pieces by 
 agitation in sand and water. Specimens in my 
 possession, show that they have been principally 
 derived from two elegant extinct species of ferns, 
 which are peculiar to the wealden. The one is cha- 
 racterised by its slender and minutely divided leaflets 
 (Sphenopteris Mantellii Tab. 72) ; the other by 
 the distribution of the nervures of the leaves (Lon- 
 chopteris Mantellii Tab. 73). This plant has also 
 been found in the valley of Bray by M. Graves of 
 
 TAB 73. PINNA OF LONCHOPTERIS MANTELLII : TILGATE FOREST. 
 (A fossil fern, peculiar to the wealden.) 
 
 Beauvais, in the lower Boulonnais in France, and 
 in Sweden, in strata supposed to be of the same 
 epoch as the wealden. 
 
 These ferns probably did not exceed a few 
 
 feet in height ; I have a stem of the sphenopteris 
 
 which must have belonged to a plant five or 
 
 six feet high. Several other species are associated 
 
 B B 2 
 
372 
 
 THE WONDERS QF GEOLOGY. 
 
 LECT. IV. 
 
 with these remains j but the two plants above 
 named constitute by far the greatest proportion of 
 the fossil vegetables of Tilgate Forest. My cabinet 
 
 TAB. 74. PINNA OF A FERN IN FRUCTIFICATION; IN SANDSTONE; 
 FROM TILGATE FOREST. 
 
 Fig. 1. Natural size. 2. Three leaflets magnified. 
 
 contains a remarkable specimen, in which the parts 
 of fructification are beautifully preserved in a sili- 
 cified state (Tab. 74). Leaves of cycadece, and 
 seed-vessels of restiacece, occur in the ironstone of 
 Heathfield in Sussex ; they are supposed to be of 
 the same species as specimens from Bornholm. 
 Among the plants from Heathfield are impressions 
 which bear a close resemblance to those of the foliage 
 of the cypress ; while others appear to be refer- 
 able to fuci. The stalks of a species of mare's-tail 
 
45. CLATHRARIA AND ENDOGENITES. 373 
 
 (Equiselum Lyellii*) abound in the blue limestone 
 of Pounceford. 
 
 4-5. CLATHRARIA AND ENDOGENITES. The 
 stems of two plants, very distinct from each other, 
 are the only vegetables of any considerable mag- 
 nitude that occur throughout the wealden of the 
 south-east of England. I have not detected the 
 slightest trace of wood like that of the forest of 
 Portland, nor observed any indications of drifted 
 and perforated masses similar to those which are so 
 common in the sands and clays of the chalk, and 
 other formations. 
 
 In my former publication on the fossils of Tilgate 
 Forest, I described the plants which I now place 
 before you. The first species consists of stems, 
 with numerous tubular cavities lined with quartz 
 crystals, and presenting a structure decidedly ana- 
 logous to the cacti, or euphorbiae ; they have an ex- 
 ternal coating of carbonaceous matter, and, on the 
 removal of this coaly crust, the outer surface has 
 a remarkably eroded appearance. The stems vary 
 from a few inches to two feet in circumference ; I 
 have seen fragments which, when united, gave a 
 length of five feet. There are no indications of 
 branches, but many of the specimens taper at each 
 end, and are of a clavated form, as in some species 
 of cactus. Dr. Fitton describes an assemblage of 
 these stems, which he observed before their removal, 
 imbedded in clay, in a cliff to the east of the white- 
 * Geology of the South-East of England, p. 245. 
 
374 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 rock at Hastings : they were lying with their largest 
 diameter in a horizontal position, and consisted of 
 a silicious stem or nucleus, coated by lignite, which 
 not only invested the stem, but also extended 
 beyond each extremity. The stems, when cut and 
 polished, exhibit the monocotyledonous* structure; 
 Count Sternberg considers them as related to the 
 palms. This fossil vegetable, from the characters 
 above specified, has been named Endogenites erosa. 
 
 TAB. 75. PORTION OF THE STEM OF CLATHRARIA LYJSLLII: 
 TILGATE FOREST. 
 
 (One-fourth the natural size.) 
 
 The other plant (Clathraria^ Lyellii) bears an 
 analogy to the yucca, and dracaena, or dragon-blood 
 
 * Dr. Fitton has given beautiful engravings of these fossils 
 in the Memoir already cited, Plates XIX. and XX. 
 
 f Clathraria, from clathrum, latticed or cross-barred ; in 
 allusion, to the markings on the surface. 
 
45. 
 
 FOSSIL FRUITS OF THE WEALDEN. 
 
 375 
 
 plant. Stems, with the markings of the bases of 
 the leaves, point out the relation of this vegetable 
 to the arborescent ferns,* while its internal structure 
 is essentially different. This interesting specimen 
 
 TAB. 76. FRUITS AND CONES OF THE WEA.LDEN, 
 
 Fig. 1 . Seed-vessel of Clathraria Lyellii. 2. Cone from the Isle of Purbeck. 
 3. Cone from Kent. 4. Cone from Pippingford. f 
 
 (Tab. 75, p. 374) exhibits an internal axis, sur- 
 rounded by a false bark, the surface of which is 
 
 * The reader may form an idea of the height and proportions 
 of these elegant trees, by inspecting a specimen of tree-fern, 
 forty-five feet high, from Bengal (alsophila brunoniana), on the 
 staircase of the British Museum. 
 
 t Figs. 2, 3, 4, are reduced one-half from Dr. Fitton's Me- 
 moir, PI. XXII. 
 
376 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 scored with the markings derived from the attach- 
 ment of the leaf- stalks. The clathraria has only 
 been found in the quarries of Tilgate Forest ; I 
 have fragments of stems indicating a large size. 
 
 46. SEED-VESSELS. Not only are the stems and 
 leaves of plants and trees preserved in the wealden 
 beds, but even very delicate seed-vessels are some- 
 times found in the grit and sandstone. A small 
 oval carpolithe (Tab. 76, fig. 1) is the most common. 
 M. Adolphe Brongniart considers it probable, that 
 this may belong to the Clathraria Lyellii* The 
 seed-vessels of coniferous trees also occur. These 
 drawings (Tab. 76, figs. 2, 3, 4) are from specimens 
 belonging to Dr. Fitton, who has figured and de- 
 scribed them in the memoir to which I have before 
 referred ; I particularly claim your attention to 
 fig. 4, which is half the size of the original ; this 
 beautiful cone was found imbedded in grit, in a 
 quarry on Ashdown Forest, on the estate of Henry 
 Shirley, Esq., and is remarkable for the double 
 prominences on the scales. 
 
 47. FOSSIL SHELLS. The shells of the wealden, 
 a series of the principal species of which I have 
 placed before you (Tab.77), belong to but few genera ; 
 and although whole tracts of country are composed of 
 their remains, and many of the limestones are mere 
 conglomerates of shells, yet the species are not 
 numerous ; a character perfectly agreeing with that 
 which prevails among the existing genera of our 
 
 See Geology of the South-East of England, p. 246. 
 
47. 
 
 FOSSIL SHELLS OF THE WEALDEX. 
 
 377 
 
 rivers. The bivalve shells chiefly consist of muscles 
 (referable to a genus called unio by conchologists), 
 the casts of which are abundant in some of the sand- 
 stones ; and several species of cyclas,* that occur in 
 
 < .8 "^^ 9 
 
 TAB. 77. SHELLS AND CRUSTACEA OP THE WEALDEN. 
 
 Fig. 1. Paludina Sussexiensis, from a slab of Sussex marble. 2. Mela- 
 nopsis attenuata. 3. Neritina Fittoni, natural size, and magnified. 
 4. Cyclas. 5. Psammobia tellinoides. 6, Unio Waited, with other 
 shells. 7, 9. Cypris granulosus, highly magnified. 8. Mytilus Lyellii. 
 
 myriads in the shales and clays, and resemble tertiary 
 
 shells in their state of preservation. The shales of 
 
 Pounceford are very like the clays of Castle Hill, 
 
 * A genus of lacustrine, or fresh- water bivalves. 
 
378 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 Newhaven, in respect to the layers of shelly remains 
 which occur between the strata. The grey lime- 
 stones are almost wholly composed of cyclades, im- 
 bedded in argillaceo-calcareous cement, in which 
 univalves are of rare occurrence. 
 
 The calciferous grit near Hastings is full of 
 cyclades ; but the shells are decomposed, and the 
 casts or impressions of the interior alone remain. 
 In the argillaceous septaria of the weald clay, casts 
 of small univalves, also destitute of their shells, 
 abound. In Langton-green quarry, near Tunbridge- 
 wells, layers of argillaceous rock inclose impressions 
 of numerous shells ; and among others a remarkable 
 species of unio (Tab. 77? fig. 6). This spiral uni- 
 valve, melanopsis attenuate* (Tab. 66, and 77, fig. 2), 
 belongs to a freshwater genus ; it occurs in the 
 shale at Pounceford, in a beautiful state of preser- 
 vation. This minute and elegant shell (Tab. 77, 
 fig. 3), is dispersed among small snail-shells in the 
 grit of Tilgate Forest ; I have named it neritina 
 Fittoni, in honour of Dr. Fitton, whose able inves- 
 tigations have so fully elucidated the geological 
 character and relations of the deposits below the 
 chalk. 
 
 48. SUSSEX, OR PETWORTH MARBLE. The 
 weald-clay throughout its whole extent contains 
 beds of limestone made up of a few species of 
 the univalve, called paludina (Tab. 77, fig. 1), a 
 fresh-water snail, common in rivers and lakes. The 
 shells are sometimes decomposed, and their casts 
 
48. SUSSEX MARBLE. 379 
 
 alone remain, the interstices being filled up with 
 indurated marl, or calcareous concretions. In the 
 
 TAB. 78. POLISHED SLAB op SUSSEX MARBLE. 
 (Composed of paludince and cyprides.) 
 
 coarser varieties are cavities left by the decompo- 
 sition of the shells ; in the compact masses the 
 shells are transmuted into calcareous spar, and the 
 whole has been permeated by a crystalline calca- 
 reous infiltration, of various shades of grey, blue, 
 and ochre, interspersed with pure white ; polished 
 slabs display innumerable sections of the inclosed 
 shells, and rival in interest and beauty many foreign 
 marbles. In these specimens you perceive the 
 
380 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 shells in relief on one side, and sections of the 
 inclosed remains on the opposite polished surface ;* 
 very few bivalves occur in this limestone, which, 
 from its abundance in Sussex, is commonly known 
 by the name of Sussex marble. The Petworth marble, 
 and Bethersden stone of Kent, are extensions of the 
 same beds. In western Sussex, a beautiful marble 
 mottled with green, blue, and grey, occasionally 
 occurs ; it is composed of large bivalves (unio), 
 interspersed with a few univalves and fragments of 
 bones of reptiles. The Purbeck marble, already 
 described, only differs from that of Sussex in the 
 size of the shells ; the paludinas in that limestone 
 being of a very small species. 
 
 49. FOSSIL CYPRIS, I have stated that the weal- 
 den marbles are principally composed of fresh-water 
 shells ; but other animal remains enter into their 
 composition, and which, although so minute as to 
 elude common observation, possess a high degree 
 of interest. It has been mentioned that certain 
 crustaceous animals (cypris\ abundant in fresh- 
 water, having their bodies protected by shells or 
 cases which they shed annually, occur in a fossil 
 state in the tertiary lacustrine deposits (page 249) ; 
 and I referred to the exhibition of the oxy-hydrogen 
 microscope in illustration of the forms of the living 
 species. The shields of various kinds of these 
 microscopic creatures abound in the wealden clay,-f- 
 
 * Geology of the South-East of England, p. 184 ; ibid. p. 254. 
 f Dr. Fitton's Memoir, PI. XXI. figs. 1, 2, 3, 4. 
 
50. FISHES OF THE WEALDEN. 381 
 
 septaria, and limestones, and entirely fill up the 
 cavities and interstices between the shells in some 
 varieties of Sussex marble. In these specimens of 
 shale from near Lewes, of septaria from Barcombe, 
 and of marble from Laughton, by the aid of a lens, 
 hundreds of the cases or shields of cyprides may be 
 detected. Dr. Fitton, who has investigated the 
 nature of these minute relics with his accustomed 
 acumen, has discriminated several species. These 
 enlarged drawings, from his illustrations, represent 
 a variety in which the shells are studded with 
 tubercles (Tab. 77, figs. 7, 9)* The natural size of 
 these objects does not, as you observe in the 
 specimens, exceed that of a pin's head, yet in cer- 
 tain formations, entire layers of stone are composed 
 of their consolidated remains, and they constitute 
 a large proportion of the mass of many beds of 
 Sussex marble. 
 
 50. FISHES. Detached bones, teeth, and rays 
 of fishes of the shark family, and of species allied 
 to the large river-pikes of South America, are very 
 abundant ; but rarely any united portions of the 
 skeleton, or scaly covering, are preserved ; a cir- 
 cumstance arising from the peculiar nature of 
 the wealden deposits. Strong, thick, enamelled, 
 lozenge-shaped scales, possessing a high polish, and 
 having two processes of attachment, are very abun- 
 dant in the sandstones, grits, and clays throughout 
 the wealden. In St. Leonard's and Tilgate Forests, 
 the conglomerate contains immense numbers, asso- 
 
382 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 elated with small hemispherical teeth, called by 
 the workmen fishes' -eyes. These scales and teeth 
 belong to two species of lepidotus, or bony-pike, of 
 which genus a recent species inhabits the rivers or 
 South America. It is rarely that any considerable 
 
 TAB. 79. RESTORED OUTLINE op THE LEPIDOTUS, OF THE WEALDEX. 
 (By M. Agassiz.) 
 
 number of the scales remain attached to each other 
 in their natural position ; but I have a few speci- 
 mens in wliich large portions of the scaly covering 
 retain their original character. These fishes must 
 have attained a large size. In a specimen presented 
 to me by Robert Trotter, Esq. F.G.S. of Borde Hill, 
 near Cuckfield, a considerable mass of the united 
 scales is beautifully preserved ; it is twelve inches 
 wide, and belongs to that part of the body where 
 the caudal fin commences ; the fish must therefore 
 have been ten or twelve feet long, and three feet 
 wide. Tricuspid teeth finely striated, and fin-bones 
 of five or six species of genera belonging to the 
 shark family, are of frequent occurrence. The 
 
31. REPTILES OF TILGATE FOREST. 3SIJ 
 
 fishes of the wealdeu are entirely distinct from those 
 of the chalk.* 
 
 51. REPTILES OF TILGATE FOREST. It will 
 doubtless excite your surprise to learn that the 
 whole of the enormous bones, and teeth, I have 
 placed on the table, are those of reptiles,f and that 
 not a vestige of any of the mammalia occurs in the 
 wealden. Even these teeth, which so strikingly 
 resemble the incisors of the rhinoceros, and these 
 bones of the feet and toes, so similar in their con- 
 struction and magnitude to those of the hippopo- 
 tamus, all belong to oviparous quadrupeds ! Many 
 of the specimens before you can be referred to 
 certain extinct forms of saurians, or lizards ; but 
 others are yet undetermined, in consequence of my 
 want of leisure, and distance from any extensive 
 collection of comparative anatomy. The deter- 
 mination of the fossil bones of the wealden is indeed 
 no easy task ; for while in many marine deposits, 
 considerable portions of the skeletons, or even the 
 entire forms, are often discovered ; in the wealden, 
 with the exception of but three or four examples, 
 
 * The following fishes of the wealden, in my museum, have 
 been named by M. Agassiz. Pycnodus microdon, Lepidotus 
 Fittoni, L. Mantellii, Hybodus grossiconus, H. marginalis, 
 H. polyprion. A small species, Lepidotus minor, occurs in the 
 Furbeck limestone. 
 
 f This lecture was illustrated by several hundred specimens 
 of bones and teeth of reptiles from the wealden ; many of such 
 enormous size, that the assemblage resembled an accumulation 
 of the disjointed skeletons of gigantic elephants or mastodons. 
 
384 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 every bone, tooth, and scale, has been found apart 
 from each other ; and as if to render the task still 
 more perplexing, the relics of several different spe- 
 cies are scattered, as it were, at random through 
 the rocks. Every specimen, as I have before re- 
 marked, bears evidence of having been transported 
 from a distance ; it would seem as if the limbs and 
 carcases of the animals were floated down the stream, 
 and rolled backwards and forwards by the tides, and 
 the bones broken, before they became imbedded in 
 the mud of the delta. To collect these scattered 
 fragments, and extricate them from the solid rock ; 
 to reunite them into a whole, and assign to each 
 skeleton of the respective animals, the bones which 
 once belonged to it, yet not to confound the dif- 
 ferent species together such is the labour which 
 the comparative anatomist has to perform, who un- 
 dertakes to investigate the structure of the wealden 
 reptiles. I reserve for the next lecture some ob- 
 servations on the economy and habits of the reptile 
 tribes, and will now describe the fossil relics before 
 us. 
 
 52. FOSSIL TURTLES. The bones and plates of 
 turtles are very common in the Purbeck limestone, 
 and in the grit, sandstone, and shale of Tilgate 
 Forest. They are referable to two or more fresh- 
 water, and one marine species ; the former appear 
 to be analogous to an emys, or fresh- water turtle, 
 described by Cuvier,* as occurring in the Jura 
 * Oss. Foss. Tom. V. p. 232. 
 
33. FOSSIL CROCODILES. 385 
 
 limestone at Soleure. It is a very flat species, and 
 probably attained two feet in length. The ribs of 
 a trionyx (which is also a fresh-water turtle), have 
 been discovered in the shale of Pounceford, and 
 grit of Tilgate Forest ; the external surface of the 
 ribs or dorsal plates is shagreened all over, as is 
 usual in these turtles, which have no shelly covering, 
 but only a thick, tough skin, or integument; the 
 recent species inhabit the Nile and Euphrates.* 
 
 53. FOSSIL CROCODILES. The skeletons of the 
 crocodiles, alligators, and gavials, those well-known 
 reptiles of Egypt, India, and America, possess 
 characters which render their fossil bones easily 
 recognisable by the comparative anatomist. The 
 
 TAB. 80. TOOTH OF CROCODILE IMBEDDED IN SANDSTONE ; FROM 
 TILGATE FOREST. 
 
 peculiar structure of the teeth, as you may observe 
 
 in this specimen (Tab. 80), affords certain indications 
 
 * Geology of the South-East of England, p. 255. 
 
 c c 
 
386 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 of the original animal. The teeth of the crocodile 
 are very numerous ; they are of a conical form 
 (Plate III. fig. 10), and consist of a succession of 
 cones, like a series of thimbles, of various sizes, 
 fitted into each other ; they are striated externally, 
 and have a prominent lateral ridge ; as the outer 
 tooth wears away, a new one is ready to supply its 
 place ; the teeth of the old crocodile are therefore as 
 fresh as those of the young animal but just escaped 
 from its shell. The interior of the teeth is never 
 completely filled up ; hence, at whatever age a tooth 
 may be removed, there is found, either in the socket, 
 or in the cavity of the tooth itself, a new germ, in 
 a greater or less state of advancement, ready to 
 occupy the place of the old one, when the latter 
 shall be removed; and this succession is often re- 
 peated. In the fossil before us (Tab. 80), the 
 internal structure is well displayed, in consequence 
 of the removal of a portion of the external surface 
 of the old tooth. Detached bones of several spe- 
 cies of crocodiles are scattered through the Tilgate 
 strata. From the difference observable in the form 
 of the teeth, they appear referable to two kinds 
 the one belonging to that division of crocodiles, 
 with long slender muzzles, named gavial ; the 
 other to a species of crocodile, properly so called,* 
 and resembling a fossil species found at Caen. 
 Among the hundreds of teeth and bones of cro- 
 codiles collected in the wealden, no portions of the 
 * Geology of the South-East of England, p. 26. 
 
 
54. SWANAGE CROCODILE. 387 
 
 jaws, or any united parts of the skeleton, have been 
 observed ; but in the Purbeck beds a specimen has 
 recently been discovered that affords an interesting 
 illustration of the osteology of one of the Tilgate 
 species. 
 
 4 3 
 
 TAB. 81. SECTION AT SWANAGE BAY. 
 
 1. Chalk. 2. Chalk marl. 3. Hastings beds. 4. Purbeck limestone. 
 5. Portland stone. 
 
 54. THE SWANAGE CROCODILE (Plate I.) Swan- 
 age, or Swanwich, is a little town on the east of the 
 Isle of Purbeck, the inhabitants of which carry on 
 a brisk trade in the exportation of stone from the 
 numerous quarries in the vicinity, there being a 
 fine bay and good anchorage for vessels. The town 
 stands at the mouth of the bay, about six miles 
 E.S.E. of Corfe Castle. The section (Tab. 81), 
 exposed by the coast, explains the geological struc- 
 ture of the country, and presents the following 
 series of strata: First, beds above the chalk; 
 secondly, chalk; thirdly, Hastings beds; fourthly, 
 the Purbeck limestone ; and lastly, the Portland 
 stone, which occupies the lowermost place in the 
 series. I need not, in this place, dwell on the 
 
 * Dr. Fitton. Geological Transactions, vol. iv. PI. X. c. 
 cc 2 
 
388 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 dislocations of these rocks, and the causes by which 
 they have been disturbed and thrown into their 
 present position. In the summer of 1837, the 
 workmen employed in a quarry, in the immediate 
 vicinity of Swanage, had occasion to split asunder 
 a large slab of the Purbeck limestone, when, to their 
 great astonishment, they perceived many bones and 
 teeth on the surfaces they had just exposed. As 
 this was no ordinary occurrence, for although scales 
 of fishes, shells, &c. were frequently observed in 
 the stone, bones had never before been noticed, 
 both slabs were carefully preserved by the pro- 
 prietor of the quarry ; and fortunately my intel- 
 ligent friend, Robert Trotter, Esq. happening to 
 visit Swanage a short time afterwards, heard of the 
 discovery, and with that liberality and ardour for 
 the advancement of science for which he is distin- 
 guished, obtained the specimens, and presented 
 them to me. I have cleared away the stone, so far 
 as the brittle state of the bones will permit without 
 injury, and they are now rendered two as interesting 
 groups of crocodilian remains as have been dis- 
 covered in this country. 
 
 In these specimens a considerable portion of the 
 left side of the lower jaw (PL I. fig. 1), with two teeth 
 attached, is preserved ; many teeth are scattered 
 over the stone, and numerous dermal (PL I. figs. 3, 3), 
 or skin-bones, which are readily distinguished, not 
 only by their form, but also by their deeply pitted 
 surface. The pelvis (PL I. figs. 6, 7, 7, 9) is nearly 
 
55,56,57. DISCOVERY OF THE IGUANODON. 389 
 
 entire, and there are many bones of the spine 
 (PI. I. figs. 2, 2), (caudal, and dorsal vertebra, and 
 chevron-bones, PI. I. fig. 5), ribs (PL I. figs. 4, 4), 
 and some of the long bones of the extremities. 
 
 55. THE PLESIOSAURUS. Several bones, and 
 vertebrae of the neck and back of the extraordinary 
 extinct reptile, called plesiosaurus,* whose remains 
 are found in such prodigious numbers in the lias, 
 occur in the calciferous sandstone of Tilgate Forest, 
 and prove that this animal was an inhabitant of the 
 sea into which the river of the wealden flowed. 
 
 56. THE MEGALOSAURUS.-J- The fissile limestone 
 of Stonesfield, of which I shall speak in the next 
 lecture, has long been celebrated for the teeth and 
 bones of a gigantic reptile, to which Dr. Buckland 
 has given the name of megalosaurus. Vertebrae, 
 bones, and teeth of this animal have been found in 
 the Tilgate grit, and in the clays and sandstones of 
 the wealden, associated with the remains of turtles, 
 crocodiles, and the still more colossal oviparous 
 quadruped the iguanodon, which I now proceed to 
 notice. 
 
 57. THE IGUANODON (Plates II. and III). It is 
 several years since the discovery of a mutilated 
 fragment of a tooth led me to suspect the existence 
 of a gigantic herbivorous animal in the strata of 
 Tilgate Forest, which subsequent researches con- 
 
 * Plesiosaurus, akin to a lizard ; this reptile will be described 
 in the fifth lecture. 
 
 f Megalosaurus, great lizard. 
 
390 THE WONDERS OF GEOLOGY. LECT. IV- 
 
 firmed.* This is the fragment : it is part of the 
 crown of a tooth, resembling in its prismatic form 
 the incisor of one of the herbivorous mammalia, 
 worn by use. The enamel is thick in front and 
 thin behind, and by this disposition a sharp cutting 
 edge is maintained in every stage. Here, then, is 
 a character, which if we bear in mind the principles 
 of comparative anatomy enforced in the second 
 lecture, (page 132,) will afford us certain indica- 
 tions as to the nature of the animal to which it 
 belonged. The structure of the tooth, and its 
 worn surface, prove that it is referable to a species 
 that fed on vegetables ; the absence of a fang, and 
 the appearance of the base, not broken, but indented, 
 show that the shank has been absorbed from the 
 pressure of a new tooth, which has grown up and 
 supplanted the old one; a process too familiar to 
 require explanation. *|- 
 
 In the teeth before us we trace every gradation 
 of this change, from the perfect form (Tab. 82, 
 fig. 2, and PL III. fig. 3), the partially worn speci- 
 mens (Tab. 82, figs. 4, 5, and PL III. figs. 6, 7), to 
 
 * " On the teeth of the iguanodon, a newly-discovered fossil 
 herbivorous reptile, from the strata of Tilgate Forest." Philos. 
 Trans. 1825. 
 
 f It cannot be requisite to notice the vulgar error that the 
 first teeth in children have no fangs ; it may however elucidate 
 the remarks in the text, if the reader be reminded that the ab- 
 sence of fangs in the teeth shed in childhood, results from the 
 absorption of the fang of the old teeth, occasioned by the pres- 
 sure of those which are to supply their place. 
 
TEETH OF THE IGUANODON. 
 
 391 
 
 the mere stump (figs. 1, 3), in which the crown is 
 worn flat, and the absorption of the fang complete. 
 
 TAB. 82. TEETH OP THE IGTTANODON, FROM TILGATE FOREST. 
 
 Figs. 1, 3. Tooth worn flat, and the fang absorbed. 2. Tooth of a young 
 animal. 4. Outer, and 5, inner, surface of a tooth of an adult. 6. Late- 
 ral view of the serrated edge of fig. 5, magnified, a, The surface worn 
 by mastication, c, The indentation produced by pressure of the new 
 tooth. 
 
 The teeth, when perfect, are of a prismatic form, 
 and remarkable for the prominent ridges which ex- 
 tend down the front, and the serrated lateral margins 
 of the crown (Tab. 82, fig. 6, the serrated edge 
 
392 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 magnified). By a powerful microscopic examination, 
 the ivory in the teeth of the iguanodon is found to 
 be composed of close-set tubes, radiating in a wavy 
 course from the cavity of the pulp of the tooth, to 
 the superficies, each tube being also minutely un- 
 dulated ; and this structure is distinctly seen on the 
 surface in some examples.* 
 
 But although by this mode of induction the 
 grand division of the animal kingdom to which 
 the original belonged was ascertained, a rigid com- 
 parison of the teeth with those of recent species 
 was necessary, to arrive at more satisfactory results. 
 In a fossil state, no teeth at all analogous had been 
 noticed ; and after a fruitless research through the 
 collections of comparative anatomy in London, I 
 found, in the jaws of a recent iguana, f the type 
 for which I had so long sought in vain. The 
 iguanas are land lizards, natives of many parts of 
 America and the West Indies, and are rarely met 
 with north or south of the tropics. They are from 
 three to five feet in length, and feed on insects and 
 vegetables, climbing trees, and chipping off the 
 tender shoots. They nestle in the hollows of rocks, 
 and deposit their eggs, which are like those of 
 turtles, in the sands or banks of rivers. The iguana 
 is furnished with a row of very small, closely-set, 
 pointed teeth, with serrated edges, which have no 
 
 * Professor Owen, " On the structure of Teeth," &c. 
 t Prepared by Mr. Stutchbury, the intelligent curator of the 
 Bristol Institution. 
 
57. TEETH OF THE IGUANODON. 393 
 
 distinct alveoli or sockets, but are attached at the 
 base, and by the outer surfaces of the fangs, to 
 the jaw, the alveolar process forming an external 
 parapet ; there is no internal bony covering. The 
 new teeth do not, as in the crocodile, spring up in 
 the centre of the cavities of the old, and rise through 
 them, but proceed from near the inner part of their 
 base, and by pressure, occasion an absorption of a 
 portion of the fangs of the old teeth, which they 
 ultimately displace, by destroying their adhesion to 
 the dentary bone. The teeth of the iguana closely 
 resemble the perfect fossil tooth, Tab. 48, fig. 2, 
 and Plate III. fig. 3, except in size ; those of the 
 recent animal scarcely exceeding in magnitude the 
 teeth of the common mouse. But in the iguana 
 the teeth never present a worn surface ; they are 
 broken or chipped off by use, but not ground 
 smooth as in the herbivora. The reason is obvious; 
 none of the existing reptiles are furnished with 
 cheeks or moveable coverings to their jaws, and 
 therefore cannot perform mastication ; their food or 
 prey is seized by the teeth and tongue, and swallowed 
 whole. But apart from this discrepancy, the teeth 
 and mode of dentition of the fossil animal are so 
 perfectly analogous to those of the iguana, that I 
 have named the original the IGUANODON, signifying 
 an animal having teeth like the iguana. In the 
 course of the last summer I discovered in sandstone, 
 in a quarry in Tilgate Forest, a portion of the lower 
 jaw of the iguanodon, that confirms the inferences 
 
394 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 which many years since I ventured to deduce from 
 the structure of the teeth alone. 
 
 From the gigantic size of the fossil teeth, as 
 compared with the recent, I was led to conclude 
 that many of the colossal bones, collected from 
 time to time, in Tilgate Forest, belonged to the 
 same kind of animal. By comparing the bones 
 with the skeleton of the iguana, (presented to 
 me by Baron Cuvier,) I succeeded in deter- 
 mining many parts of the skeleton ; and at length 
 was enabled to restore, as it were, the form of 
 the iguanodon, and ascertain its proportions ; the 
 correctness of my deductions was shortly to be 
 put to the test, by a discovery in a neighbouring 
 county. 
 
 58. THE MAIDSTONE IGUANODON. (Plate II.) 
 In May, ISS-i, some workmen employed in a 
 stone-quarry, in the occupation of Mr. W. H. Ben- 
 sted, of Maidstone, observed in a mass of rock 
 which they had blasted, several portions of what 
 they supposed to be petrified wood ; they pre- 
 served the largest piece for the inspection of 
 Mr. Bensted, who at once perceived that it was 
 a portion of bone belonging to some gigantic 
 animal. He therefore gave directions that every 
 fragment should be collected, and after much la- 
 bour and research, succeeded in obtaining those 
 pieces, which are now united, and form a specimen 
 of the highest interest ; he also cleared away part 
 of the surrounding stone, so as to expose many of 
 
58. THE MAIDSTONE IGUANODON. 395 
 
 the bones, which I have since completely developed 
 and joined together.* 
 
 The specimen consists of a considerable number 
 of the bones, composing the inferior portion of the 
 skeleton of an iguanodon, which, when living, must 
 have been upwards of 60 feet in length. The bones 
 are imbedded in the stone in a very confused man- 
 ner, few of them being in their natural order of 
 juxta-position, and all more or less flattened and 
 distorted. The following are well displayed; and 
 there are many fragments of others, which are too 
 imperfect to admit of being determined. 
 
 Two thigJi-bones, each 33 inches long.f Plate II. figs. 1, 2. 
 One leg-bone (tibia), 30 inches long. Plate II. fig. 3. 
 Metatarsal and phalangeal bones of the hind feet ; these much 
 
 resemble the corresponding bones of the hippopotamus. 
 
 Plate II. figs. 4, 4, 4. . 
 Two claw-bones (unguical phalanges), which were covered by the 
 
 nail or claw ; these correspond with the unguical bones of 
 
 the land tortoise. Plate II. fig. 5 ; III. 2. 
 Two finger, or metacarpal bones of the fore-feet, each 14 inches 
 
 in length. Plate II. fig. 6. 
 
 A radius, or bone of the fore-arm. Plate II. fig. 7. 
 Several dorsal and caudal vertebra (bones of the spine and tail). 
 
 Plate II. figs. 8, 8, 8. 
 
 * Appendix L. 
 
 f The thigh-bone, or femur of the iguanodon is very re- 
 markable (Plate III. fig. 11) ; it has a large trochanter (a) 
 opposite to the head of the bone, and a process (b) on the inner 
 side for the attachment of powerful adductor muscles ; the front 
 of the lower extremity is deeply grooved (d) anteriorly, as in 
 the toad ; the shaft of the bone is subquadrangular. 
 
396 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 Fragments of several ribs. Plate II. figs. 9, 9, 9. 
 
 Two clavicles, or collar-bones, each 28 inches in length, resem- 
 bling the bone figured Plate IV. figs. 1, 2, Geology of the 
 South-East of England. These bones are of a very singular 
 form, and differ essentially from any known clavicle, yet it 
 seems impossible to assign them to any other place in the 
 skeleton. Plate II. figs. 10, 10. 
 
 Two large flat hatchet-shaped bones, which appear to belong to 
 the pelvis, and are probably the ossa ilia. PI. II. figs. 11, 11. 
 
 A cJievr on-lone, or one of the inferior spinous processes of a 
 vertebra of the tail. PI. II. fig. 12. 
 
 A portion of a tooth, and the impression of another. The pre- 
 servation of these teeth is most fortunate, as the identity of 
 the animal with the iguanodon of Tilgate Forest is thereby 
 completely established. 
 
 The geological position of this specimen forms an 
 exception to what has been previously remarked of 
 the fossils of the wealden ; for while the bones in 
 the latter are found associated with terrestrial and 
 fluviatile remains only, the Maidstone specimen is 
 imbedded in a marine deposit. This discrepancy, 
 however, in no wise affects the arguments previously 
 advanced, as to the fluviatile origin of the strata of 
 the wealden ; it merely shows that part of the delta 
 had subsided, and was covered by the chalk ocean, 
 whilst the country of the iguanodon was still in ex- 
 istence, and the body of an iguanodon was drifted 
 out to sea, and became imbedded in the sand ; in 
 like manner, as at the present day, bones of land 
 quadrupeds may not only be engulfed in deltas, but 
 also in the deposits of the adjacent ocean. 
 
 This specimen possesses a high interest, because 
 it proves that the separate bones found in the strata 
 
58. THE MAIDSTONE IGUANODON. 39J 
 
 of Tilgate Forest, and which I had assigned to the 
 iguanodon, solely from analogy, have been correctly 
 appropriated ; and we obtain also a knowledge of 
 many interesting facts relating to the structure and 
 economy of the original. Thus as the iguana lives 
 chiefly upon vegetables, it is furnished with long 
 slender feet, by which it is enabled to climb trees 
 with facility, in search of food ; but no tree could 
 have borne the weight of the colossal iguanodon, 
 its movements must have been confined to the land 
 and water, and it is evident that its enormous bulk 
 must have required limbs of great strength. Ac- 
 cordingly we find, that the hind feet, as in the 
 hippopotamus, rhinoceros, and other large mam- 
 malia, were composed of strong, short, massy bones, 
 furnished with claws, not hooked as in the iguana, 
 but compressed as in the land tortoises ; thus form- 
 ing a powerful support for the enormous leg and 
 thigh. But the bones of the hands, or fore feet, 
 are analogous to those of the iguana, long, slender, 
 flexible, and armed with curved claws (PI. III. 
 fig. 1), the exact counterpart of the nail-bones of 
 the recent animal; thus furnishing prehensile in- 
 struments fitted to seize the palms, arborescent ferns, 
 and dragon-blood plants, which probably consti- 
 tuted the food of the original. Here we have 
 another interesting example of that admirable adap- 
 tation of structure to the necessities and conditions 
 of every form of existence, which is alike manifest, 
 whether our investigations be directed to the beings 
 
398 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 around us, or to the organization of those which 
 have long since passed away. 
 
 The stone in which the bones are imbedded is of 
 that hard variety of the grey, arenaceous limestone, 
 called Kentish rag, which is much employed in 
 various parts of Kent, and in the west of Sussex, 
 for building, and for repairing the roads. This 
 rag belongs to the Shanklin sands, and abounds in 
 the marine shells which are characteristic of that 
 division of the chalk formation. In the quarry in 
 which the remains of the iguanodon were found, 
 Mr. Bensted has also discovered fossil wood per- 
 forated by lithodomi, or boring shells ; impressions 
 of leaves, stems of trees, ammonites) nautili, &c. ; 
 large conical striated teeth, which are referable to 
 some species of sauroid fishes ; scales and teeth of 
 several other kinds of fishes, and among these, 
 a jaw or mandible of that singular genus, the 
 chimera. 
 
 59. SIZE OF THE IGUANODON. Gigantic as must 
 have been the animal discovered by Mr. Bensted, 
 there are in my collection many bones which indi- 
 cate proportions yet more colossal. A thigh bone 
 (PI. III. fig. 11), from the west of Sussex, (pre- 
 sented to me by J. Napper, Esq.) is 3 feet 8 inches 
 long, and 35 inches round, at the largest extremity 
 (c) ; and the shaft of another femur is 24 inches in 
 circumference ! The following is the result of a 
 careful comparison of some of the fossil bones, with 
 the corresponding ones of the iguana, with the view 
 
5 59. SIZE OF THE IGUANODON. 399 
 
 of ascertaining the probable average size of the 
 original animal (vide Geol. of the South-East of 
 England, p. 315); we should, however, bear in 
 mind, that some individuals must have far exceeded 
 this estimate, and, if they bore the proportions of 
 the recent iguana, have been upwards of 100 feet 
 in length ! 
 
 Length of the iguanodon from the snout to the ) 
 
 tip of the tail P feet 
 
 of the head 4$ 
 
 of the body 13 
 
 of the tail 52 
 
 Height from the ground to the top of the head 9 
 
 Circumference of the body 14 
 
 Length of the thigh and leg 8 
 
 Circumference of the thigh 7& ,, 
 
 Length of the hind foot from the heel to thei 
 point of the long toe f 
 
 Of course this calculation is offered but as an 
 approximation ; we cannot, however, for a moment 
 doubt, that an animal possessing a body requiring 
 thigh bones eight inches in diameter to support it, 
 must have been of prodigious magnitude ; such 
 bones, if covered with muscles and integuments, 
 would form limbs upwards of seven feet in circum- 
 ference I 
 
 The vertebrae, or bones of the spine, are generally 
 found detached and mutilated ; but I have one spe- 
 cimen in which the first six (caudal) vertebrae of 
 the tail are admirably preserved, and lie imbedded 
 in a block of stone in their natural position (PI. III. 
 
400 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 fig. 8). The bodies of these bones are slightly con- 
 cave at both extremities ; the spinous processes (a), 
 which are almost perfect, are 15 inches high. There 
 are three chevron bones (6, b), or inferior spinous 
 processes, lying beneath the vertebrae. The width, 
 or rather height, of the tail to which these bones 
 belonged, must have been at least 27 inches, and 
 its entire length about 22 feet. 
 
 I will notice one other remarkable feature in 
 the structure of the iguanodon. The iguanas are 
 distinguished among the lizards by their exuberant 
 dermal appendages ; some have serrated processes 
 or spines on the back, as in this specimen from 
 Barbadoes, presented to me by R. I. Murchison, 
 Esq., late President of the Geological Society; 
 and others on the tail ; while many have warts and 
 horny protuberances on the head and snout. The 
 extraordinary relic before you, is the FOSSIL HORN 
 of the iguanodon (Plate III. fig. 5), from Tilgate 
 Forest.* It is composed of bone, and bears marks 
 on its surface of the integument with which it was 
 invested ; it is four inches high ; the base, which is 
 of an irregular elliptical form, is 3.2 inches by 2.1. 
 In this additional analogy between the iguanodon 
 and the iguana, we perceive another instance of 
 that law of co-relation of form of which our re- 
 searches have afforded so many examples. 
 
 The fossil plants with which the remains of the 
 
 * See Geology of the South-East of England, p. 312. 
 Plate III. fig. 5. 
 
60. THE HYL/EOSAURUS. 401 
 
 iguanodon are associated, were furnished with tough, 
 thick stems, like those of the palms, tree-ferns, 
 yucca, &c. These probably constituted the food of 
 the original ; and the peculiar structure of its teeth 
 was evidently required, and admirably adapted, for 
 the mastication of such vegetable productions. 
 
 60. THE HYL/EOSAURUS ( Wealden lizard, PI. IV.) 
 In the summer of 1832, 1 discovered, in the lime- 
 stone of Tilgate Forest, the remains of a reptile, not 
 less extraordinary than the iguanodon, and which I 
 have named hylceosaurus, to denote its relation to 
 the wealden formation. A block of calciferous grit 
 had been broken up by the quarrymen, and a great 
 part of it thrown upon the road, as it was not sup- 
 posed to contain any thing interesting. Accidentally 
 visiting the quarry, I noticed indications of bones 
 in several pieces of stone on the road-side, and 
 therefore directed that the remaining portions should 
 be collected, and sent to my residence. Having 
 cemented the fragments together, and chiselled off 
 the hard grit in which the bones were wholly im- 
 bedded, and to which they are still attached, I 
 succeeded, after much labour, in displaying a con- 
 siderable portion of the skeleton of a reptile, which 
 blends the osteology of the crocodile with that of the 
 lizard. The vertebrae of the neck (PL IV. 1), 
 several of the back (PL IV. 2), many ribs (PL IV. 3), 
 and the bones of the sternum (PL IV. 6), or chest, 
 remain ; there are also dermal, or skin-bones, which, 
 in animals of this family, support the large scales. 
 D D 
 
402 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 But the most extraordinary parts, are many enor- 
 mous^ angular, spinous bones (PI. IV. 4, 5), which 
 lie in the direction of the vertebral column, and 
 evidently extended like a serrated fringe along the 
 back of the animal. Many of the existing lizards, 
 particularly the cyclura, have remarkable appen- 
 dages of this kind. This figure, from Dr. Harlan's 
 valuable work, shows how largely these curious 
 processes are developed in some species.* 
 
 TAB. 83. CYCLURA CARINATA. 
 (A recent lizard, allied to the iguana. Dr. Jfarlan.) 
 
 The length of the hylasosaurus was probably 
 about twenty-five feet. In the same block of stone 
 were masses of vegetable remains, with seed-vessels, 
 and stems of Clathraria Lyellii.^ I have lately 
 obtained many bones of this extraordinary creature 
 from a bed of clay near Crawley ; and also a most 
 interesting specimen of the vertebral column, com- 
 
 * Medical and Physical Researches, by R. Harlaii, M.D., 
 F.G.S., 8vo. Philadelphia, 1835. 
 
 f Geology of the South-East of England, p. 316, PL V. is 
 an excellent lithograph of this specimen, by Mr. Pollard, of 
 West- street, Brighton. 
 
 
61, G2. FOSSIL BIRDS. 403 
 
 prising nearly thirty vertebrae of the tail and back, 
 with many dermal and spinous bones, ribs, &c. ex- 
 hibiting very peculiar osteological characters. The 
 teeth of the hylseosaurus are unknown ; but in the 
 quarries where the bones of that reptile were dis- 
 covered, I have found teeth of a very peculiar form 
 (PI. III. fig. 4), which appear to have belonged to 
 a reptile, and are entirely distinct from those of the 
 megalosaurus, iguanodon, crocodile, and plesiosau- 
 rus, whose remains occur in the Tilgate strata. 
 
 61. FLYING REPTILES, or PTERODACTYLES. 
 The remains of thin and slender bones, evidently 
 belonging to animals capable of flight, were among 
 my earliest discoveries in the strata of Tilgate 
 Forest. Some of these bones appear to be refer- 
 able to those singular extinct creatures called ptero- 
 dactyles, or wing-toed reptiles, which had a beak 
 like a bird, a long neck, and a wing sustained prin- 
 cipally on an elongated toe. It is sufficient in this 
 place, merely to notice the occurrence of these re- 
 mains in the wealden ; the subject will be resumed 
 in the succeeding lecture. 
 
 62. FOSSIL BIRDS. In describing the fossil 
 remains of the animals of the older tertiary epoch, 
 it was stated that several recent genera of birds 
 were contemporaneous with the palaeotheria (page 
 231); but that no traces of this class of animated 
 nature had been found in the chalk, or in strata of 
 an earlier date. The discovery of the undoubted 
 remains of birds in the grit of Tilgate Forest, 
 
 DD 2 
 
404 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 became, therefore, a fact of great interest and im- 
 portance in the physical history of the globe. After 
 selecting the bones which appeared to belong to 
 pterodactyles, several remained which bore so 
 striking a resemblance to those of waders, that I 
 ventured to describe them as such in my work on 
 the Fossils of Tilgate Forest ; and this opinion was 
 corroborated by Baron Cuvier, to whom I showed 
 the specimens on his last visit to England. Sub- 
 sequently, I have obtained the inferior portion of 
 a leg-bone (tarso-metatarsal), in which the oval 
 cicatrix, or articulation for the hind toe, is distinctly 
 visible, and proves unquestionably that the bone 
 belonged to some kind of wader, perhaps a heron ; 
 the position of the hind toe in birds, varying in 
 accordance with the habits and economy of the 
 respective orders (page 136). These are the most 
 ancient remains of birds that have hitherto been 
 discovered.* 
 
 63. THE COUNTRY OF THE IGUANODON. By 
 this survey of the strata and organic remains of the 
 wealden, we have acquired data from which, by the 
 principles of induction, already explained (page 347), 
 we may obtain secure conclusions as to the nature 
 of the country from whence those spoils were de- 
 rived, of the animals by which it was inhabited, 
 and of the vegetables that covered its surface. 
 
 * See a Memoir " On the Bones of Birds discovered in the 
 Strata of Tilgate Forest," by the author: Geological Trans- 
 actions, 1838. 
 
63. COUNTRY OF THE IGUANODON. 405 
 
 That country must have been diversified by hill and 
 dale, by streams and torrents, the tributaries of its 
 mighty river. Arborescent ferns, palms, and yuccas, 
 constituted its groves and forests ; delicate ferns and 
 grasses, the vegetable clothing of its soil; and in 
 its marshes, equiseta, and plants of a like nature, 
 prevailed. It was peopled by enormous reptiles, 
 among which the colossal iguanodon and the mega- 
 losaurus were the chief. Crocodiles and turtles, 
 flying reptiles and birds, frequented its fens and 
 rivers, and deposited their eggs on the banks and 
 shoals; and its waters teemed with lizards, fishes, 
 and mollusca. But there is no evidence that Man 
 ever set his foot upon that wondrous soil, or that 
 any of the animals which are his contemporaries 
 found there a habitation : on the contrary, not only 
 is evidence of their existence altogether wanting, but 
 from numberless observations made in every part of 
 the globe, there are conclusive reasons to infer, that 
 man and the existing races of animals were not 
 created, till myriads of years after the destruction of 
 the iguanodon country a country, which language 
 can but feebly portray, but which the magic pencil 
 of a Martin, by the aid of geological research, has 
 rescued from the oblivion of the past, and placed 
 before us in all the hues of nature, with its appalling 
 dragon-forms, its forests of palms and tree-ferns, and 
 the luxuriant vegetation of a tropical clime.* 
 
 * See the Frontispiece ; an engraving on steel, from an 
 original painting by John Martin, Esq., K.L. 
 
406 THE WONDERS OF GEOLOGY. LECT. IV. 
 
 64. SEQUENCE OF GEOLOGICAL CHANGES. Let 
 us now review the sequence of those stupendous 
 changes, of which our examination of the geolo- 
 gical phenomena of the south-east of England has 
 afforded such incontrovertible evidence. From the 
 facts brought before us, we learn that at a period 
 incalculably remote, there existed in the northern 
 hemisphere an extensive island or continent, pos- 
 sessing a climate of such a temperature, that its 
 surface was clothed with coniferous trees, arbores- 
 cent ferns, and plants allied to the cycas and zamia; 
 and that the ocean which washed its shores was 
 inhabited by turtles and reptiles of extinct genera. 
 This island and its forests suffered a partial subsi- 
 dence, which was effected in such manner that many 
 of the trees, although torn and rent, still retained 
 their erect position ; and the zamise, and a consi- 
 derable layer of the vegetable mould in which they 
 grew, remained undisturbed. In this state an inun- 
 dation of fresh-water covered the once flourishing 
 forest, and deposited upon the soil and around the 
 trees a calcareous mud, which gradually consoli- 
 dated into fine limestone ; water, holding flint in 
 solution, percolated through the mass, and silicified 
 the now submerged trees and plants. A further 
 depression took place a body of fresh water, 
 brought down by land -floods and rivers, over- 
 whelmed the petrified forest, and heaped upon it 
 accumulations of debris, which their parent streams 
 had washed away from the rocks over which they 
 
64. GEOLOGICAL CHANGES. 407 
 
 had flowed. The country traversed by the rivers, 
 like that of the submerged forest, enjoyed a tropical 
 climate ; it was clothed with palms, arborescent 
 ferns, and plants allied to the yucca and the dra- 
 caena, and tenanted by enormous reptiles, croco- 
 diles, and land and fresh-water turtles ; and in its 
 waters were various kinds of fishes, mollusca, and 
 aquatic plants. The bones and teeth of the reptiles 
 the remains of the turtles the teeth and scales 
 of fishes the shells of the snails and muscles 
 the stems, leaves, and even seed-vessels, of the 
 trees, were carried down by the stream, and de- 
 posited in the mud of the delta, beneath which 
 the petrified forest was now buried. This state 
 continued for a long period : another change took 
 place ; the country and its inhabitants were swept 
 away, and the delta, and the strata on which it 
 reposed, were submerged to a great depth, and 
 formed part of the bottom of a profound ocean, 
 whose waters teemed with myriads of zoophytes, 
 shells, and fishes, of species that are now no more. 
 Thermal waters, holding calcareous and silicious 
 matter in solution, were poured into its basin, and, 
 in its tranquil depths, layers of flint and chalk were 
 deposited. And so rapidly were these changes 
 effected, that fishes, while in the act of swimming, 
 were arrested in their progress, and became suddenly 
 enveloped in a bed of rock. This epoch was of 
 considerable duration : at length elevatory move- 
 ments began to take place, the bottom of the deep 
 
408 THE WONDERS OF GEOLOGY. LECT. iv. 
 
 was slowly up-heaved, and as the elevation con- 
 tinued, the depositions which had formed in the 
 basin of the ocean, and had become consolidated, 
 were broken up, and as they approached the surface 
 were acted upon by the waves. The chalk strata 
 now began to suffer degradation and destruction, 
 and the delta of the country of the iguanodon 
 emerged above the waters ; and finally, even the 
 ancient petrified forest was brought to view, and 
 became dry land. At length some masses rose to 
 an elevation of a few hundred feet above the level 
 of the sea, and formed a group of islands ; but, in 
 the depressions of the strata beneath the waters, 
 deposits went on, from the waste of the cliffs on 
 the sea-shores. Large mammalia now inhabited 
 such portions of the former ocean-bed as were 
 clothed with vegetation, and as they died their 
 skeletons were enveloped in the accumulations of 
 mud and gravel which were forming in the bays 
 and estuaries. This era also passed away the 
 elevation continued other portions of the bed of 
 the chalk-ocean became dry land and at length 
 also those newer strata, iri which the remains of 
 the mammoth and the elk, the last tenants of the 
 country, were entombed. The oak, elm, ash, and 
 other trees of modern Europe, sprang up where 
 the palms and tree-ferns once flourished ; the deer, 
 boar, and horse, ranged where the mighty reptiles 
 once ruled sole monarchs of the country; and 
 lastly, man appeared, and took possession of the 
 
65. RETROSPECT OF GEOLOGICAL MUTATIONS. 400 
 
 soil. At the present time, a city* stands on the 
 deposits which contain the remains of the elephant 
 and the elk ; the huntsman courses, and the shep- 
 herd tends his flocks, on the elevated and rounded 
 masses of the bottom of the ancient chalk-ocean ;-|- 
 the farmer reaps his harvests upon the cultivated 
 soil of the delta of the iguanodon ; J and the archi- 
 tect seeks, beneath the petrified forest, for the 
 materials with which to construct his edifices. 
 
 65. RETROSPECT OF GEOLOGICAL MUTATIONS. 
 Such is a plain enunciation of the results of our 
 investigations ; but I will embody these inductions 
 in a more impressive form, by employing the meta- 
 phor of an Arabian writer, and imagining some 
 higher intelligence from another sphere, to describe 
 the physical mutations of which he may be supposed 
 to have taken cognizance, from the period when the 
 forests of Portland were flourishing, to the present 
 time. Countless ages ere man was created, he might 
 say, I visited these regions of the earth, and beheld 
 a beautiful country of vast extent, diversified by 
 hill and dale, with its rivulets, streams, and mighty 
 rivers, flowing through fertile plains. Groves of 
 palms and ferns, and forests of coniferous trees, 
 clothed its surface ; and I saw monsters of the 
 reptile tribe, so huge that nothing among the ex- 
 isting races can compare with them, basking on the 
 banks of its rivers and roaming through its forests ; 
 
 * Brighton. f The South Downs. 
 
 The wealds of Kent and Sussex. 
 
410 THE WONDFUS OF GEOLOGY. LECT. IV. 
 
 while, in its fens and marshes, were sporting thou- 
 sands of crocodiles and turtles. Winged reptiles of 
 strange forms shared with birds the dominion of the 
 air, and the waters teemed with fishes, shells, and 
 Crustacea. And after the lapse of many ages I 
 again visited the earth ; and the country, with its 
 innumerable dragon-forms, and its tropical forests, 
 all had disappeared, and an ocean had usurped their 
 place. And its waters teemed with nautili, ammo- 
 nites, and other cephalopoda, of races now extinct; 
 and innumerable fishes and marine reptiles. And 
 thousands of centuries rolled by, and I returned, 
 and, lo ! the ocean was gone, and dry land had 
 again appeared, and it was covered with groves and 
 forests; but these were wholly different in character 
 from those of the vanished country of the iguanodon. 
 And I beheld, quietly browsing, herds of deer of 
 enormous size, and groups of elephants, mastodons, 
 and other herbivorous animals of colossal magni- 
 tude. And I saw in its rivers and marshes the 
 hippopotamus, tapir, and rhinoceros; and I heard 
 the roar of the lion and the tiger, and the yell of 
 the hyena and the bear. And another epoch passed 
 away, and I came again to the scene of my former 
 contemplations ; and all the mighty forms which I 
 had left had disappeared, the face of the country no 
 longer presented the same aspect ; it was broken 
 into islands, and the bottom of the sea had become 
 dry land, and what before was dry land had sunk 
 beneath the waves. Herds of deer were still to 
 
66. RETROSPECT OF GEOLOGICAL MUTATIONS. 41 1 
 
 be seen on the plains, with swine, and horses, and 
 oxen ; and wolves in the woods and forests. And 
 I beheld human beings, clad in the skins of animals, 
 and armed with clubs and spears ; and they had 
 formed themselves habitations in caves, constructed 
 huts for shelter, inclosed pastures for cattle, and 
 were endeavouring to cultivate the soil. And a 
 thousand years elapsed, and I revisited the country, 
 and a village had been built upon the sea-shore, and 
 its inhabitants supported themselves by fishing ; 
 and they had erected a temple on the neighbouring 
 hill, and dedicated it to their patron saint. And 
 the adjacent country was studded with towns and 
 villages ; and the downs were covered with flocks, 
 and the valleys with herds, and the corn-fields 
 and pastures were in a high state of cultivation, 
 denoting an industrious and peaceful community. 
 And lastly, after an interval of many centuries, 1 
 arrived once more, and the village was swept away, 
 and its site covered by the waves ; but in the 
 valley and on the hills above the cliffs a beautiful 
 city appeared ; with its palaces, its temples, and its 
 thousand edifices, and its streets teeming with a 
 busy population in the highest state of civilization ; 
 the resort of the nobles of the land, the residence 
 of the monarch of a mighty empire. And I 
 perceived many of its intelligent inhabitants ga- 
 thering together the vestiges of the beings which 
 had lived and died, and whose very forms were 
 now obliterated from the face of the earth, and 
 
412 
 
 THE WONDERS OF GEOLOGY. 
 
 LECT. IV. 
 
 endeavouring, by these natural memorials, to trace 
 the succession of those events of which I had been 
 the witness, and which had preceded the history of 
 their race.* 
 
 * The concluding portion of these remarks refers to the 
 changes that have taken place on the Sussex coast, during the 
 historical era. Before the Conquest, the greater part of the little 
 fishing town of Brighthelmston (BrigJithelms-toivn], or Brighton, 
 was situated below the cliffs, on a terrace of beach and sand, now 
 covered by the waves. The Church, dedicated to St Nicholas, 
 the patron saint of fishermen, was placed on an eminence, that 
 it might serve as a land-mark. The inroads of the sea led to 
 the erection of buildings on the high ground, and its progressive 
 encroachment gradually diminished the area of the ancient town, 
 till at length a sudden inundation, but little more than a century 
 ago, swept away the houses, fortifications, and inclosures, that 
 remained. The sea has, therefore, only resumed its former 
 position at the base of the cliffs ; the site of the old town having 
 been an ancient bed of shingle, abandoned for ages by the ocean, 
 perhaps contemporaneously with the retreat of its waters from 
 the valley of the Ouse. Should the advancement of the sea be 
 still progressive, Lewes Levels may again become an estuary, 
 and the town of the Cliff, and the hamlet of Landport, regain 
 the characters from which their names were derived. See page 45. 
 
 Illustrations of the Geology of Sussex, page 292. Geology 
 of the South-East of England, page 23. Dallaway's Western 
 Sussex, Vol. I. page 55. 
 
APPENDIX. 
 
 A. Page 21. THE SURFACE OF THE MOON. The moon 
 is the only planetary body placed sufficiently near us, to 
 have the inequalities of its surface rendered distinctly visible 
 with the telescope. Attendant on the earth, and having 
 nearly the same density, we may reasonably infer that the 
 mineral substances of which it is composed do not differ 
 essentially from those on the surface of our own planet. 
 Astronomers now generally admit that the moon is sur- 
 rounded by a very clear atmosphere, but which is so low 
 that it scarcely occasions a sensible refraction of the rays 
 of light when it passes over the fixed stars. Many of the 
 dark parts of the moon, particularly the part called mare 
 crisium, appear to be covered with a fluid, which may pro- 
 bably be more transparent and less dense than water, as 
 the form of the rocks and craters are seen beneath it, but 
 not so distinctly as in the lighter parts of the moon's sur- 
 face. To examine the moon with a reference to its exter- 
 nal structure, the defining power of the telescope should be 
 of the first quality, sufficient to show the projections of the 
 outer illuminated limb as distinctly as they appear when 
 the moon is passing over the disk of the sun during a solar 
 eclipse. With such a telescope, and a sufficient degree of 
 light and of magnifying power, almost every part of the 
 moon's surface appears to be volcanic, containing craters of 
 enormous magnitude and vast depth : the shelving rocks, 
 and the different internal ridges within them, mark the 
 stations at which the lava has stood and formed a floor 
 during different eruptions ; while the cones in some of the 
 craters resemble those formed within modern volcanoes. 
 The largest mountain on the southern limb of the moon, 
 like the largest volcanic cone on the earth, Chimborazo, 
 
414 APPENDIX. 
 
 has no deep crater on its summit. There are indeed the 
 outlines of the crater, but it is nearly filled up ; while from 
 the foot of this lunar mountain diverging streams of lava 
 seem to flow in different directions, to the distance of six 
 hundred miles. The longest known current of modern 
 lava on the earth is in Iceland ; it extends sixty miles ; but 
 the volcanoes in that island bear no proportion to those of 
 the moon in magnitude. Mr. Bakewell. 
 
 B. Page 60. THE LAKE OF THE SOLFATARA. Its tem- 
 perature was, in the winter, in the warmest parts, above 
 80 deg. of Fahrenheit, and it appears to be pretty constant; 
 for I have found it to differ a few degrees only, in January, 
 March, May, and the beginning of June ; being nearly 
 twenty degrees above the mean temperature of the atmo- 
 sphere, it must therefore be supplied with heat from a sub- 
 terraneous source. Kircher lias detailed in his Mundm 
 Subterraneus various wonders respecting this lake, most of 
 which are unfounded, such as that it is unfathomable, that 
 it has at the bottom the heat of boiling water, and that 
 floating islands rise from the gulf. It must certainly be very 
 difficult, or even impossible to fathom a source which rises 
 with so much violence from a subterraneous excavation ; 
 and at a time when chemistry had made small progress, it 
 was easy to mistake the disengagement of carbonic acid 
 for an actual ebullition. The floating islands are real, but 
 neither the Jesuit nor any of the writers who have since 
 described this lake, have had a correct idea of their origin, 
 which is exceedingly curious. The high temperature of 
 this water, and the quantity of carbonic acid that it con- 
 tains, render it peculiarly fitted to afford a pabulum or 
 nourishment to vegetable life ; the banks of travertine 
 are every where covered with reeds, lichens, confervas, and 
 various kinds of aquatic vegetables. At the same time 
 that the process of vegetable life is going on, the crystalli- 
 zation of the calcareous matter, which is every where 
 deposited in consequence of the escape of carbonic acid, 
 likewise proceeds, and gives a constant milkiness to what 
 from its tint would otherwise be a blue fluid. So rapid is 
 the vegetation, owing to the decomposition of the carbonic 
 
 
APPENDIX. 415 
 
 acid, that even in winter masses of confervae and lichens, 
 mixed with deposited travertine, are constantly detached 
 hy the currents of water from the hank, and float down the 
 stream, which being a considerable river, is never without 
 many of these small islands on its surface. They are some- 
 times only a few inches in size, and composed merely of 
 dark green confervae, or purple or yellow lichens ; but, 
 occasionally, are even several feet in diameter, and con- 
 tain seeds and various species of common water-plants, 
 which are usually more or less incrusted with marble. 
 There is, I believe, no place in the world where there is a 
 more striking example of the opposition or contrast of the 
 laws of animate and inanimate nature, of the forces of 
 inorganic chemical affinity, and those of the powers of life. 
 Vegetables, in such a temperature, and every where sur- 
 rounded by food, are produced with a wonderful rapidity ; 
 but the crystallizations are formed with equal quickness, 
 and are no sooner produced than they are destroyed toge- 
 ther. Notwithstanding the sulphureous exhalations from 
 the lake, the quantity of vegetable matter generated there, 
 and its heat, make it the resort of an infinite variety of 
 insect tribes ; and, even in the coldest days in winter, 
 numbers of flies may be observed on the vegetables sur- 
 rounding its banks, or on its floating islands. Their larvae 
 may also be seen there, sometimes incrusted and entirely 
 destroyed by calcareous matter, as well as the insects them- 
 selves, and various species of shell-fish that are found 
 amongst the vegetables which grow and are destroyed in 
 the travertine on its banks. Snipes, ducks, and other 
 water-birds, often visit these lakes, probably attracted by 
 the temperature and the quantity of food in which they 
 abound ; but they usually confine themselves to the banks, 
 as the carbonic acid disengaged from the surface would be 
 fatal to them, if they ventured to swim upon it when tran- 
 quil. In May 18 , I fixed a stick on a mass of travertine 
 covered by the water, and examined it in the beginning of 
 the April" following, for the purpose of determining the 
 nature of the depositions. The water was lower at this 
 time ; yet I had some difficulty, by means of a sharp- 
 pointed hammer, in breaking the mass which adhered to 
 the bottom of the stick ; it was several inches in thickness. 
 The upper part was a mixture of light tufa and leaves of 
 
416 APPENDIX. 
 
 confervas ; below this was a darker and more compact 
 travertine, containing black and decomposed masses of 
 confervse ; in the inferior part, the travertine was more 
 solid, and of a grey colour, but with cavities which I have 
 no doubt were produced by the decomposition of vegetable 
 matter. I have passed many hours, I may say days, in 
 studying the phenomena of this wonderful lake ; it has 
 brought trains of thought into my mind connected with 
 the early changes of our globe ; and I have sometimes 
 reasoned from the forms of plants and animals preserved 
 in marble in this thermal source, to the grander depositions 
 in the secondary rocks, where the zoophytes or coral insects 
 have worked upon a grand scale, and where palms and 
 vegetables, now unknown, are preserved with the remains 
 of crocodiles, turtles, and gigantic extinct saurian animals, 
 which appear to have belonged to a period when the whole 
 globe possessed a much higher temperature. I have like- 
 wise often been led, from the remarkable phenomena 
 surrounding me in that spot, to compare the works of man 
 with those of nature. The baths, erected there nearly 
 twenty centuries ago, present only heaps of ruins, and 
 even the bricks of which they were built, though hardened 
 by fire, are crumbled into dust ; whilst the masses of tra- 
 vertine around, though formed by a variable source from 
 the most perishable materials, have hardened by time, and 
 the most perfect remains of the greatest ruins in the eternal 
 city, such as the triumphal arches and the Colosseum, owe 
 their duration to this source. 
 
 How marvellous are those laws by which the humblest 
 types of organic existence are preserved, though born 
 amidst the sources of their destruction, and by which a 
 species of immortality is given to generations floating, as it 
 were, like evanescent bubbles on a stream raised from the 
 deepest caverns of the earth, and instantly losing what 
 may be called its spirit in the atmosphere. Sir Humphrey 
 Davys Last Days of a Philosopher. 
 
 C. Page 62. CAVERNS. One of the most common 
 appearances in limestone caverns, is the formation of 
 what are called stalactites, from a Greek word signifying 
 
APPENDIX. 417 
 
 distillation, or dropping. To explain these, a brief de- 
 scription of the mode of their production will be necessary. 
 Whenever water filters through a limestone rock, it dissolves 
 a portion of it ; and on reaching any opening, such as a 
 cavern, either at its sides or roof, it forms a drop, the 
 moisture of which is soon evaporated by the air, leaving a 
 small circular plate of calcareous matter ; another drop 
 succeeds in the same place, and adds, from the same cause, 
 a fresh coat of incrustation. In time, these successive 
 additions produce a long, irregular, conical projection from 
 the roof, which is continually being increased by the fresh 
 accession of water loaded with calcareous or chalky matter, 
 which it deposits on ; the outside of the stalactite already 
 formed, and trickling down, adds to its length by subsiding 
 to the point, and being dried up as before ; precisely in 
 the same manner as during frosty weather, icicles, which 
 are stalactites of ice, or frozen water, are formed on the 
 edges of the eaves of a roof. When the supply of water 
 holding lime in solution is too rapid to allow of its evapo- 
 ration at the bottom of the stalactite, it drops to the floor 
 of the cave, and drying up gradually, forms, in like manner, 
 a stalactite rising upwards from the ground, instead of 
 hanging from the roof; these are called, for the sake of 
 distinction, stalagmites. 
 
 It frequently happens, where these processes are unin- 
 terrupted, that a stalactite hanging from the roof, and a 
 stalagmite formed immediately under it from the super- 
 abundant water, increase till they unite, and thus consti- 
 tute a natural pillar, apparently supporting the roof of the 
 grotto; it is to the grotesque forms assumed by stalactites, 
 and these natural columns, that caverns owe the interesting 
 appearances, described in such glowing colours by those 
 who witness them for the first time. Saturday Magazine, 
 No. 42. 
 
 D. Page 62. WEYER'S CAVE. This cave is situated in 
 a ridge of limestone hills, running parallel to the Blue 
 mountains. A narrow and rugged fissure leads to a large 
 cavern, where the most grotesque figures, formed by the 
 percolation of water through beds of limestone, present 
 E E 
 
418 APPENDIX. 
 
 themselves, while the eye, glancing onward, watches the 
 dim and distant glimmers of the lights of the guides some 
 in the recess below, and others in the galleries above. 
 Passing from these recesses, the passage conducts to a 
 flight of steps that leads into a large cavern of irregular 
 form, and of great beauty. Its dimensions are about thirty 
 feet by fifty. Here the incrustations hang just like a sheet 
 of water that has been frozen as it fell ; there they rise into 
 a beautiful stalactitic pillar, and yonder compose an ele- 
 vated seat, surrounded by sparry pinnacles. Beyond this 
 room is another, more irregular, but more beautiful. Be- 
 sides having sparry ornaments in common with the others, 
 overhead is a roof of the most admirable and singular 
 formation. It is entirely covered with stalactites, which 
 are suspended from it like inverted pinnacles. They are 
 of the finest material, and are most beautifully shaped and 
 embossed. In another apartment, an immense sheet of 
 transparent stalactite extends from the roof to the floor, 
 which, when struck, emits deep and mellow sounds, like 
 those of a muffled drum. Farther on is another vaulted 
 chamber, which is one hundred feet long, thirty-six wide, 
 and twenty-six high. Its walls are filled with grotesque 
 concretions. The effect of the lights placed by the guides 
 at various elevations, and leaving hidden more than they 
 reveal, is extremely fine. At the extremity of another range 
 of apartments, a magnificent hall, two hundred and fifty feet 
 long, and thirty-three feet high, suddenly appears. Here 
 is a splendid sheet of rock-work, running up the centre of 
 the room, and giving it the aspect of two separate and noble 
 galleries ; this partition rises twenty feet above the floor, 
 and leaves the fine span of the arched roof untouched. 
 There is here a beautiful concretion, which has the form 
 and drapery of a gigantic statue ; and the whole place is 
 filled with stalagmitical masses of the most varied and 
 grotesque character. The fine perspective of this room, 
 four times the length of an ordinary church, and the 
 amazing vaulted roof spreading overhead, without any 
 support of pillar or column, produces a most striking effect. 
 In another apartment, which has an altitude of fifty feet, 
 there is at one end an elevated recess, ornamented with a 
 group of pendant stalactites of unusual size, and singular 
 beauty. They are as large as the pipes of a full-sized 
 
APPENDIX. 419 
 
 organ, and ranged with great regularity ; when struck, 
 they emit mellow sounds of various keys, not unlike the 
 tones of musical glasses. Other cavities, profusely studded 
 with sparry incrustations, extend through the limestone 
 rock. The length of this extraordinary group of caverns 
 is not less than one thousand six hundred feet. Abridged 
 from " A Narrative of the Visit to the American Churches" 
 by Drs. Reed and Matheson. 
 
 E. Page 80. RECENT FORMATION OF SANDSTONE, 
 " A sandstone occurs in various parts of the northern 
 coast of Cornwall, which affords a most instructive ex- 
 ample of a recent formation ; since we here actually detect 
 Nature at work in converting calcareous sand into stone. 
 A very considerable portion of the northern coast of 
 Cornwall is covered with a calcareous sand, consisting 
 of minute particles of comminuted shells, which, in some 
 places, has* accumulated in quantities so great, as to 
 have formed hills of from forty to sixty feet in elevation. 
 In digging into these sand hills, or upon the occasional 
 removal of some part of them by the winds, the remains 
 of houses may be seen : and in some places, when the 
 churchyards have been overwhelmed, a great number of 
 human bones may be found. The sand is supposed to 
 have been originally brought from the sea by hurricanes, 
 probably at a remote period. At the present moment, the 
 progress of its incursion is arrested by the growth of the 
 arundo arenacea. The sand first appears in a slight but 
 increasing state of aggregation on several parts of the shore 
 in the Bay of St. Ives; but, on approaching the Gwythian 
 river, it becomes more extensive and indurated. On the 
 shore opposite Godrevy Island, an immense mass of it 
 occurs, of more than a hundred feet in length, and from 
 ten to twenty in depth, containing entire shells and frag- 
 ments of clay-slate ; it is singular that the whole mass 
 assumes a striking appearance of stratification. In some 
 places, it appears that attempts have been made to separate 
 it, probably for the purpose of building, for several old 
 houses in Gwythian are built of it. The rocks in the 
 vicinity of this recent formation in the Bay of St. Ives, are 
 E E 2 
 
420 APPENDIX. 
 
 greenstone and clay slate, alternating with each other. 
 The clay slate is in a state of rapid decomposition, in con- 
 sequence of which large masses of the hornblende rock 
 have fallen in various directions, and given a singular cha- 
 racter of picturesque rudeness to the scene. This is 
 remarkable in the rocks which constitute Godrevy Island. 
 It is around the promontory of New Kaye, that the most 
 extensive formation of sandstone takes place. Here it 
 may be seen in different stages of induration, from a state 
 in which it is too friable to be detached from the rock upon 
 which it reposes, to a hardness so considerable that it 
 requires a very violent blow from a sledge to break it. 
 Buildings are here constructed of it ; the church of Cran- 
 stock is entirely built with it ; and it is also employed for 
 various articles of domestic and agricultural uses. The 
 geologist who has previously examined the celebrated spe- 
 cimen from Guadaloupe, will be struck with the great 
 analogy which it bears to this formation. Suspecting 
 that masses might be found containing human bones, 
 if a diligent search were made in the vicinity of those 
 cemeteries which have been overwhelmed, I made some 
 investigations in those spots, but, I regret to add, without 
 success. The rocks upon which the sandstone reposes, are 
 alternations of clay slate, and slaty limestone. The in- 
 clination of the beds is SS.W., and at an angle of 40. 
 Upon a plane formed by the edges of these strata, lies a 
 horizontal bed of rounded pebbles, cemented together by 
 the sandstone which is deposited immediately above them, 
 forming a bed of from ten to twelve feet in thickness, and 
 containing fragments of slate, and entire shells; and exhi- 
 biting the same appearance of stratification as that noticed 
 in St. Ives Bay. Above this sandstone lie immense heaps 
 of drifted sand. But it is on the western side of the pro- 
 montory of New Kaye, in Fishel Bay, that the geologist 
 will be most struck with this formation ; for here no other 
 rock is in sight. The cliffs, which are high, and extend 
 for several miles, are entirely composed of it ; they are 
 occasionally intersected by veins and dykes of breccia. 
 In the cavities, calcareous stalactites of rude appearance, 
 opaque, and of a grey colour, hang suspended. The beach 
 is covered with disjointed fragments, which have been 
 detached from the cliffs above, many of which weigh two 
 
APPENDIX. 421 
 
 or three tons." From the Transactions of the Royal Geo- 
 logical Society of Cornwall, by Dr. Paris. 
 
 F. Page 95. LITHODOMI, or BORING MOLLUSCA; which 
 have the power of perforating rocks. Every one who has 
 walked by the sea-side must have observed the blocks and 
 masses of the chalk rocks full of perforations ; and if his 
 curiosity have induced him to examine these with attention, 
 he will have perceived that though many of the 6avities 
 are empty, some of them contain the shelly remains of the 
 animals which once inhabited them. The power possessed 
 by creatures so delicate, and with such fragile coverings, 
 of excavating the solid rock, has naturally excited much 
 speculation as to the mode by which the perforations are 
 effected ; and it is now generally admitted, that it is not 
 by mechanical power only that the feeble inhabitants of 
 the boring shells are able to form themselves a secure 
 asylum in the rock, but by the secretion of a liquid which 
 acts chemically on the stone, softens it, and renders it 
 capable of being removed with facility. In a late volume 
 of the Philosophical Transactions, there is an interesting 
 paper on the economy of molluscous animals, by Mr. Gray, 
 which throws much light on the subject. It appears that, 
 although teredines, pholades, and other boring shells, are 
 covered with short spines and striae, by means of which 
 they were supposed capable of rasping stones, yet other 
 mollusca which inhabit stony cavities are perfectly smooth. 
 On the shore, near Kemptown, a pholas, which has a 
 rasping apparatus, and a venus, wholly destitute of a rugous 
 surface, may be seen in cavities of the chalk. Shells 
 of this kind have not been observed to bore into any other 
 substances (wood excepted) than shells, marl, chalk, lime- 
 stone, and sandstone, consolidated by calcareous cement. 
 Granite appears to resist all the dissolving powers of the 
 mollusca. Thus, in the Plymouth Breakwater, in which 
 limestone and granite are employed and placed side by 
 side, the patella, or limpets, form their r.ounded holes in 
 the former, while they do not in the slightest degree alter 
 the surface of the latter, except by clearing off from it any 
 adherent calcareous substance. 
 
422 APPENDIX. 
 
 G. Page 96. OBSERVATIONS ON THE TEMPLE OF SERAPIS, 
 AT PUZZUOLI, NEAR NAPLES; in a Letter to W.H.Fitton, 
 M.D., from Charles Babbage, Esq. This paper com- 
 mences with a general description of the present state of 
 the Temple of Serapis, and gives the measurement of the 
 three marble columns which remain standing, and which, 
 from the height of eleven feet to that of nineteen, are per- 
 forated on all sides by the modiola lithophaga (of Lamarck) ; 
 the shells of that animal remaining in the holes formed by 
 them in the columns. A description follows of the present 
 state of twenty-seven portions of columns, and other frag- 
 ments of marble, and also of the several incrustations 
 formed on the walls and columns of the temple. 
 
 From these and other data, Mr. Babbage concludes : 
 
 1. That the temple was originally built at, or nearly at 
 the level of the sea, for the convenience of sea-baths, as 
 well as for the use of the hot spring which still exists on 
 the land side of the temple. 
 
 2. That, at a subsequent period, the ground on which 
 the temple stood, subsided slowly and gradually ; the salt 
 water, entering through a channel which connected the 
 temple with the sea, or by infiltration through the sand, 
 mixed itself with the water of the hot spring containing 
 carbonate of lime, and formed a lake of brackish water in 
 the area of the temple, which, as the land subsided, became 
 deeper, and formed a dark incrustation. 
 
 The proofs are, that sea-water alone does not produce a 
 similar incrustation ; and that the water of the hot spring 
 alone produces an incrustation of a different kind; also, 
 that serpulse are found adhering to this dark incrustation ; 
 and that there are lines of water-level at various heights 
 from 2.9 feet to 4.6 feet. 
 
 3. The area of the temple was now filled up to the height 
 of about seven feet with ashes, tufa, or sand, which stopped 
 up the channel by which sea-water had been admitted. 
 The waters of the hot spring thus confined, converted the 
 area of the temple into a lake, from which an incrustation 
 of carbonate of lime was deposited on the columns and walls. 
 The proofs are, that the lower boundary of this incrustation 
 is irregular ; whilst the upper is a line of water-level, and 
 that there are many such lines at different heights; that 
 salt water has not been found to produce a similar incrus- 
 
APPENDIX. 423 
 
 tation ; that the water of the Piscina Mirabile, which is 
 distant from the sea, but in this immediate neighbourhood, 
 produces, according to an examination by Dr. Faraday, a 
 deposit almost precisely similar ; that no remains of ser- 
 pulae, or other marine animals, are found adhering to it. 
 
 4. The temple continuing to subside, its area was again 
 partially filled with solid materials ; and at this period was 
 subjected to a violent incursion of the sea. The hot- water 
 lake was filled up, and a new bottom produced, entirely 
 covering the former, and concealing also the incrustation 
 of carbonate of lime. 
 
 The proofs are, that the remaining walls of the temple 
 are highest on the inland side, and decrease in height 
 towards the sea-side, where they are lowest ; that the 
 lower boundary of the space perforated by the marine 
 lithophagi is, on different columns, at different distances 
 beneath the uppermost, or water-level line; that several 
 fragments of columns are perforated at the ends. 
 
 5. The land continuing to subside, the accumulations 
 at the bottom of the temple were submerged, and modiolae 
 attaching themselves to the columns and fragments of 
 marble, pierced them in all directions. The subsidence 
 continued until the pavement of the temple was at least 
 nineteen feet below the level of the sea. 
 
 The proofs are derived from the condition of the columns 
 and fragments. 
 
 6. The ground on which the temple stood, appears now 
 to have been stationary for some time, but it then began to 
 rise. A fresh deposition of tufa, or of sand, was lodged, 
 for the third time, within its area, leaving only the upper 
 part of three large columns visible above it. 
 
 Whether this took place before or subsequently to the 
 rise of the temple to its present level, does not appear ; but 
 the pavement of the area is at present level with the waters 
 of the Mediterranean. 
 
 The author then states several facts, which prove that 
 considerable alterations in the relative level of the land 
 and sea have taken place in the immediate vicinity. An 
 ancient sea-beach exists near Monte Nuovo, two feet above 
 the present beach of the Mediterranean. The broken 
 columns of the Temples of the Nymphs and of Neptune, 
 remain at present standing in the sea. A line of perfora- 
 
424 
 
 APPENDIX. 
 
 tions of modiolae, and other indications of a water-level 
 four feet above the present sea, are observable on the sixth 
 pier of the bridge of Caligula ; and again on the twelfth 
 pier, at the height of ten feet. A line of perforations by 
 modiolae is visible in a cliff opposite the island of Nisida, 
 thirty-two feet above the present level of the Mediter- 
 ranean. Abstract of the Proceedings of the Geological 
 Society ; March, 1834. 
 
 H. Page 325. Mr. Reade's recent observations on 
 fossil infusoria are embodied in Lecture VI. See also 
 Appendix N and O. 
 
 I. Page 328. AGASSIZ'S CLASSIFICATION OF FISHES. 
 
 TAB. 84. SCALES OF THE FOUR ORDERS OF FISHES, AS DETERMIKED 
 BY M. AGASSIZ. 
 
 1. Scale of a Ganoid order of Lepidotus. 
 
 2. Placoid order of Ray. 
 
 3. ,, Cycloid order of Salmon. 
 
 4. Ctenoid order of Beryx. 
 
APPENDIX. 425 
 
 K. Page 339. A TABULAR ARRANGEMENT OF THE FOSSIL 
 FISHES OF THE CHALK FORMATION OF THE SOUTH-EAST OF 
 ENGLAND, COLLECTED BY GIDEON MANTELL, LL.D. F.R.S. ; 
 IN THE MANTELLIAN MUSEUM AT BRIGHTON.* 
 
 (From " Recherches sur les Poissons Fossiles" by M. Agassiz.) 
 
 " Tout le monde sait que le Musfee de M. le Dr. Mantell & Brighton est une collection 
 classique pour la craie, et la formation Veldienne. Les soins minutieux que M. Mantell 
 a donnes tlepuit bicn des annees 4 ces fossiles, les ont rendus plus parlaits que tons 
 ceux des autres musfees ; car souvent il est parvenu ft les detacher entierement de la 
 roche dans laquelle ils se trouvaient; ou du moins a les produire en relief, en dfetachant 
 toutes les matieres solides qui recouvraient les parties les mieux conservees de 
 l'anhnal." 
 
 ORDER I. The Placoidians, (from 7rXa, a broad plate.) 
 The skin, covered irregularly with enamelled plates, some- 
 times of a large size, but frequently in the form of small 
 points, as in the shagreen on the skin of sharks, and the 
 tubercles on the integuments of rays. Tab. 84, fig. 2. 
 
 PTTCHODUS latissimus. Mantell's South Down Fossils. Tab. xxxii. fig. 19. 
 Agassiz, Poiss. Foss. Vol. iii. tab. 25. 
 
 polygyrus. Ibid. Tab. xxxii. figs. 23, 24. 
 
 mammillaris. Ibid. Tab. xxxii. figs. 18, 20, 25, 29, 
 
 decurrens. Tab. 58, fig. 6, page 329. 
 
 altior. South Down Fossils. Tab. xxxii. figs. 17, 21, 27. 
 
 Teeth, and perhaps vertebrae, of the above species, and a 
 few examples of their dorsal defences, (Ichthyodorulites of 
 Dr. Buckland,) are the only remains hitherto discovered. 
 (Agass. Poiss. Foss. Vol. iii. tab. 10*, 10V) The teeth 
 were referred to fishes of the genus Diodon, by previous 
 authors, and the defences were called radii, or fin-bones of 
 balistes, and siluri. 
 
 Teeth of a new species of PtycJiodus have been dis- 
 covered in the sand of New Jersey, United States, by Dr. 
 Morton. (Mortons Synopsis, PI. 18, fig. 1, 2.) I have 
 named it Ptychodus Mortoni. 
 
 PTYCHODUS, spec, undetermined. Dorsal defences, and a beautiful ex- 
 ample of a fin, are represented in the Fossils of the South 
 Downs. Tab. xxxiv. fig. 8. Tab.xxxix.andTab.xl. fig.3. 
 
 GAL-EVSpristodontus. Tab. 58, fig. 3. South Down Fossils. Tab. xxxii. 
 figs. 12 to 16. Agass. Poiss. Foss. Vol. iii. tab. xxvi. 
 fig. 14. 
 
 NOTIDANUS microdon. Tab. 58, fig. 1, page 329. Agass. Tab. xxxii. 
 fig. 22. 
 
 LAMNA appendiculata. Tab. 58. fig. 4, page 329. Agass. Tab. xxxii. 
 figs. 2, 3, 5, 6. 9. 
 
 acuminata. Agass. Tab. xxxii. fig. 1. 
 
 * Now in the British Museum. 
 
426 APPENDIX. 
 
 LAMNA Mantellii. Tab. 58, fig. 2, page 329. Agass. Tab. xxxii. figs. 4, 
 7, 8, 10. 
 
 crassissima. Not figured. 
 
 ODONTAPSIS raphiodon. Not figured. 
 
 SPIN AX major. Agass. Poiss. Foss. Vol. iii. tab. 10, figs. 8, 14. 
 PSAMMODUS asper. Poiss. Foss. Vol. iii. tab. 10, figs. 1, 3. 
 ACRODUS transversus. Poiss. Foss. Vol. iii. tab. 10, figs. 4, 5. 
 GYRODUS angustus. Poiss. Foss. Vol. ii. tab. 66a, figs. 14, 15. 
 
 The above order of fishes is represented by five genera, 
 of which one, containing twelve species, is extinct. The 
 fishes of the genera Ptychodus. Galeus, and Lamna, are 
 very widely distributed. 
 
 ORDER II. The Ganoidians, (yavos, splendour, from 
 the brilliant surface of their enamel.) These are charac- 
 terised by angular scales, formed of horny or bony plates, 
 protected by a thick layer of enamel. Tab. 84, fig. 1. 
 
 MACROPOMA Mantellii. Tab. 61, page 334. Length 24 inches. South 
 Down Fossils. Tab. xxxvii. and xxxviii. Agass. 
 Poiss. Foss. Vol. v. tab. 60b, fig. 2. 
 
 Coprolites of : South Down Fossils. Tab. ix. 
 
 figs. 5, 11. Agass. Poiss. Foss. Vol. ii. tab. 65. 
 
 The Macropoma is perhaps the most remarkable of all 
 the fossil fishes ; in most examples the membranes of the 
 stomach are preserved. 
 
 SpHffiRODUS mammillarts. Not figured. From Clayton chalk-pit. 
 DERCETIS elongatus. Tab. 62, page 335. Length 16 inches. South Down 
 
 Fossils. Tab. xxxiv.figs. 10, 11. Tab.xl. fig. 2. Agass. 
 
 Poiss. Foss. Vol. ii. tab. 66a, figs. 1 to 8. 
 
 The above order comprehends three extinct genera, with 
 three species. Another species of Dercetis has been found 
 in the chalk of Westphalia. 
 
 ORDER III. The Cteno'idians, (KTCIS, a comb.) The 
 scales of this order are pectinated on their posterior margin, 
 like the teeth of a comb, and are composed of laminae of 
 horn or bone, but have no enamel. Tab. 84, fig. 4. 
 
 BERYX Lewesiensis. (B. ornatus of Agassiz.; Tab. 64, page 337. Length 
 
 12 inches. South Down Fossils. Tab. xxxiv. fig. 6. 
 
 Tab. xxxv. Tab. xxxvi. Agass. Poiss. Foss. Vol. iv. 
 
 tab. 14a. 
 radians. Tab. 63, page 336. Length 7 inches. History of the 
 
 County of Sussex. Vol. ii. Part ii. p. 15 ; fig. 22. Agass. 
 
 Poiss. Foss. Vol. iv. tab. 14b, fig.'7. , 
 microcephalus. Agass. Poiss. Foss. Vol. iv. tab. 4c, figs. 7 to 9. 
 
APPENDIX. 127 
 
 There are other species of Beryx in the chalk of Bohemia 
 and Westphalia ; and genera nearly related to Beryx, in 
 the schist of Glaris. In England this order contains but 
 three species of a genus, of which we know but one living 
 species. 
 
 ORDER IV. The Cydoidiam, (KVK\OS, a circle.) The 
 scales smooth, with a simple margin, composed of laminae 
 of horn or bone without enamel. Tab. 84, fig. 3. 
 
 OSMEROIDES Mantellii. (Salmo ? Lewesiensis of Mantell.) Tab. 60, 
 page 333. Length 12 inches. South Down Fossils. 
 Tab. xxx. fig. 12. Tab. xxxiv. fig. 3. Tab. xl. fig. 1. 
 Agass. Poiss. Foss. Vol. v. tab. 60o. 
 
 To the above species belong the remarkable uncompressed 
 specimens in my Museum. 
 
 OSMEROIDES Lewesiensis. Agass. Poiss. Foss. Vol. v. tab. 60 C . (Salmo? 
 Lewesiensis of Mantell.) This species is more elon- 
 gated than 0. Mantellii, and the number of rays in 
 the dorsal fin is greater. 
 
 granulatus. History of Lewes. Vol. i. plate xxix. fig. 13. 
 
 The bones of the head, with the jaws and teeth, have 
 alone been discovered. Agass. Poiss. Foss. 
 
 ENCHODUS halocyon. South Down Fossils. Tab. xxxiii. figs. 2, 3, 4. 
 Tab. xliv. figs. 1, 2. Agass. Poiss. Foss. Vol. v. tab. 25. 
 figs. 11 to 6. 
 
 SAUROCEPHALUS lanciformis. (Harlan.) South Down Fossils. Tab. 
 xxxiii. figs. 7, G. Trans. Geol. Soc. of Pennsylvania, 
 Vol. i. p. 83. Agass. Poiss. Foss. Vol. v. tab. 25, figs. 
 21 to 2y. 
 
 SAURODON Leanus. (Hays.) Trans. American Philos. Society, vol. for 
 1830, plate 16. Agass. Poiss. Foss. Vol. v. tab. 25, 
 figs. 17 to 20. 
 
 HYPSODON Lewesiensis. South Down Fossils. Tab. xxxiii. fig. 8. Tab. 
 xlii. figs. 1 to 5. Agass. Poiss. Foss. Vol. v. tab. 25. 
 
 From the resemblance of the teeth of this fish, to those 
 of reptiles, it was supposed that the original belonged to 
 an extinct genus of saurians; but in 1833, a considerable 
 portion of the head, with the maxilla?, many vertebrae, &c., 
 were discovered in a block of chalk, near Lewes, and the 
 true characters of this remarkable ichthyolite determined. 
 
 *#* The following fishes have been named by M. Agassiz, 
 since the above table was constructed. 
 
 ACROGNATHXJS boop*. Tab. GO, page 333. Natural size. Agass. Poiss. 
 Foss. Vol. iii. tab. 60a, figs. 1, 4. An unique specimen 
 from Southerham quarry, near Lewes. 
 
428 APPENDIX. 
 
 AULOI.EPIS typus. Tab. 61, page 334. Length 6 inches. An unique 
 specimen, from Clayton chalk-pit, Sussex. One 
 nearly perfect example has alone been found. Poiss. 
 Foss. Vol. iii. tab. 60, figs. 5, 8. 
 
 BELONOSTOMUS cinctus. Agass. Poiss. Foss. Vol. ii. tab. 66a, figs. 10 to 13. 
 
 CHIMERA Agassizii. Agass. Poiss. Foss. Vol. iii. pi. 40, figs. 3, 5. (De- 
 termined by Dr. Buckland.) The beaks or mandibles 
 have alone been discovered. 
 
 Mantellii. Tab. 59, page 330. Agass. Poiss. Foss. Vol. iii. 
 
 pi. 40, figs. 1, 2. Two mandibles were found, many 
 years since, in a block of chalk, near Lewes. This 
 species also occurs in the Shanklin sand of Kent. A 
 beak has been found by Mr. W. H. Bensted in the 
 iguanodon quarry, near Maidstone. 
 
 TETRAPTERUS minor. Lewes. Agass. Poiss. Foss. Vol. iii. tab. 60, 
 figs. 1, 4. 
 
 CATCRUS similis. Agass. Poiss. Foss. Vol. ii. tab. 66a, fig. 9. 
 
 ACROTEMNUS faba. Poiss. Foss. Vol. ii. tab. 66a, figs. 16, 18. 
 
 L. Page 395. MAIDSTONE IGUANODON. This specimen 
 was purchased of Mr. Bensted in its broken state, and 
 presented to Dr. Mantell by the following gentlemen of 
 Brighton, the proposition originating with the two whose 
 names stand first on the list, viz. Horace Smith, Moses 
 Ricardo, Thomas Attree, George Basevi, Thomas Bodley, 
 R. Heaviside, E. Lindo, J. J. Masquerier, W. Tenant, and 
 T. Sarel, Esqrs.; Drs. Hall and Price; Revds. J. S. M. 
 Anderson, Thomas Rooper, H. M. Wagner; and Sir 
 Richard Hunter. 
 
 END OF VOL. I. 
 
 RICHARD CLAY, PRINTER, BREAD STREET HILL. 
 
DESCRIPTION OF THE FRONTISPIECE. 
 
 The Country of the Iguanodon, restored from the Geological Discoveries of 
 the Author. By JOHN MARTIN, Esq. K.L. 
 
 The mode of induction by which the geologist and comparative 
 anatomist are enabled to ascertain the form and structure of animals 
 and plants which no longer exist on the face of the earth, and even the 
 nature of the countries which they inhabited, are explained in the fol- 
 lowing pages. The researches of the Author in the wealden formation 
 (p. 344) of the south-east of England, furnished the materials from which 
 the eminent painter of "BELSHAZZAR'S FEAST," composed the striking 
 picture that forms so splendid an embellishment to this Work. 
 
 The data upon which the restorations are founded are described in the 
 Fourth Lecture (see p. 404). The picture represents a country clothed 
 with a tropical vegetation, peopled by reptiles of colossal magnitude, and 
 traversed by a river, which is seen to empty itself into the sea, in the 
 distance. Oolitic rocks (p. 361) form the heights and cliffs with which the 
 landscape is diversified. The vegetation consists of the trees and plants 
 whose fossil remains have been discovered in Tilgate Forest (p. 369) ; 
 namely, palms, arborescent ferns, clathrariae, and coniferous tree ; while 
 the lesser plants, as the cycadeae, (p. 365) and ferns (pp. 369371), are 
 distributed over the foreground. 
 
 The reptiles comprise the iguanodon (p. 389), hylaeosaurus (p. 401), 
 megalosaurus (p. 389), crocodiles (p. 385), and turtles (p. 384). An 
 iguanodon attacked by a megalosaurus and crocodile, constitutes the 
 principal group ; in the middle distance an iguanodon and hylaeosaurus 
 are preparing for an encounter; a solitary pterodactyle, or flying 
 reptile (p. 403), with its wings partly expanded, forms a conspicuous 
 object in the foreground ; while turtles are seen crawling on the banks of 
 the river. Ammonites and other shells of the Portland oolite, which is 
 the foundation rock of the country, are strewn on the shore. Wading 
 birds allied to the heron (p. 403), should have been introduced to render 
 the fauna of the iguanodon country complete. 
 
 The vigour and beauty of this successful conception of the distinguished 
 artist are equalled by the fidelity of its details. 
 
FOSSIL CROCODILE DISCOVERED AT SWANAGE 
 
DESCRIPTION OF PLATE I. 
 
 Remains of a Fossil Crocodile discovered at Swanage, by ROBERT 
 TROTTER, Esq. F.G.S. of Borda Hill, near Cuckfield. 
 
 Described pp. 387-389. 
 
 1. The left side of the lower jaw, with two teeth remaining in their 
 natural position: fig. 10, PI. III. represents one of these teeth 
 on a larger scale. 
 
 2, 2. Detached vertebrae of the back and tail, showing the transverse 
 
 and dorsal processes. 
 
 3, 3. Dermal, or skin bones : in the living animal these are disposed 
 
 in parallel rows along the spinal column, like a ridge of roof- 
 tiles, and are designed to support the large scales. 
 
 4, 4. Ribs, more or less broken. 
 
 5. Two chevron bones : these are inferior spinous processes articu- 
 lated to the vertebrae of the tail. In a specimen of caudal ver- 
 tebrae of the iguanodon, (PI. III. fig. 8, 6.) three processes of this 
 kind, but differing in form from those before us, are seen lying 
 beneath the vertebras. 
 6, 7, 8. Bones of the pelvis. 
 
 6. One of the bones of the pelvis, detached; the corresponding 
 
 bone is seen near the following. 
 
 7. 7. The bones of the ischium. 
 
 8. The remaining bones of the pelvis, attached to each other in 
 
 their natural position. 
 
 Numerous scales and teeth of a fresh -water fish, (lepidotus minor,) 
 peculiar to the Purbeck strata, are imbedded in the stone. 
 
1GUANOPON DISCOVERED NEAR MAIDSTONE 
 t; FtfJ-. l Sut. 
 
DESCRIPTION OF PLATE II. 
 
 The Remains of the Iguanodon discovered by Mr. W. H. Bensted, in a 
 Quarry of Kentish Rag, near Maidstonc. 
 
 Described pp. 394397. 
 
 1, 2. The right and left thigh-bone, or femur. 
 
 3. A leg-bone, or tibia. 
 
 4, 4, 4. Bones of the toes (metatarsal and phalangeal) of the hind feet. 
 5, 5. Two unguical, or claw-bones of the hind-foot. 
 
 6. Two metacarpal, or finger bones of the fore-foot. 
 
 7. One of the bones (radius) of the fore-arm. 
 
 8' 8, 8. Vertebrae of the back and tail : in the upper part of the specimen 
 
 a series of eight vertebrae remains. 
 9, 9, 9. Ribs : some nearly entire, others broken. 
 
 10, 10. Two clavicles, or collar-bones. 
 
 11, 11. Two bones of the pelvis (ossa ilia). 
 
 12. A chevron-bone, or inferior spinous process of the tail. 
 
III 
 
 REMAINS OF REPTILES FROM TILGATE FGRFST. 
 
DESCRIPTION OF PLATE III. 
 
 Remains of Reptiles from the strata of Tilgate Forest. 
 
 1 . One of the claw-bones of the fore-foot of the iguanodon. See p. 397. 
 
 2. One of the claw-bones of the hind-foot of the Maidstone iguanodon. 
 
 See p. 397. 
 
 3. Perfect tooth of the iguanodon, one-third the natural size. See p. 390. 
 
 4. Inner surface of a tooth of an unknown reptile. See p. 403. 
 
 5. Horn of the iguanodon. See p. 400. 
 
 6. Tooth of the iguanodon ; the crown slightly worn by use, and the 
 
 fang absorbed from pressure of the new tooth ; half the natural 
 size. See p. 390. 
 
 7. Tooth of the iguanodon, much worn ; the serrated edges being entirely 
 
 obliterated ; half the natural size. This is the individual specimen 
 which M. Cuvier mistook for an incisor tooth of the rhinoceros, 
 until a series of specimens was obtained, showing a gradual 
 transition from the perfect to the worn tooth. 
 
 8. Six vertebrae of the tail of an iguanodon, articulated to each other, 
 
 having their spinous (a) and transverse processes remaining; and 
 three chevron-bones (b b) imbedded in the stone near the vertebras. 
 From Cuckfield, by R. Trotter, Esq. See p. 399. 
 
 9. Tooth of the megalosaurus, one-third the natural size. 9*. Magnified 
 
 view of the serrated edge ot the tooth. See p. 389. 
 
 10. Tooth of the Swanage crocodile. See p. 388. 
 
 11. The right femur, or thigh-bone, of an iguanodon, imbedded in lime- 
 
 stone ; from Tilgate Forest (pp. 395398). The original was 
 3 feet 8 inches in length, a, the large process (trochanter major), on 
 the upper and outer part of the bone ; b, the inner process (tro- 
 chanter minor), for the attachment of adductor muscles, by which 
 the limbs were drawn towards each other ; c, the inner condyle ; 
 d, the groove in front of the condyles, for the passage of a tendon 
 to be inserted into the leg-bone. 
 
DESCRIPTION OF PLATE IV. 
 
 Remains of the Hylceosaurus, discovered in Tilgate Forest. 
 
 Described pp. 401,402. 
 (Size of the original specimen, four and a half feet in length.) 
 
 This plate represents the extraordinary and highly interesting fossil 
 discovered in Tilgate Forest, by the Author, in the summer of 1832. The 
 specimen exhibits the anterior or upper portion of the skeleton of an 
 extinct reptile, the hyl&osaurus, or fossil lizard of the weald. 
 
 1. Vertebrae of the neck, or cervical. 
 
 2. Vertebrae of the back, or dorsal. 
 
 3. Ribs, for the most part perfect, and but little removed from their 
 
 articulation with the vertebrae. 
 4, 4. Angular or spinous processes. 
 
 5. Three very large spinous or angular processes ; each 15 inches in 
 length. 
 
 6, 6. Two coracoid bones (belonging to the chest). 
 
 7, 7. The two omoplates, or scapulae. 
 
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