| | GEOLOGICAL THEORY AND THE EVIDENCE BY WHICH IT IS SUPPORTED. | | CHAPTER I. | | THEORY OF GEOLOGISTS. | | Geology defined—Facts and Theories—Recent Progress of Geology—Stratification of Rocks—Aqueous Rocks; of Mechanical Origin—of Chemical Origin—of Organic Origin—Igneous Rocks, Plutonic and Volcanic—Metamorphic Rocks—Summary of the Rocks that compose the Crust of the Earth—Relative Order of Position—Internal Condition of the Globe—Movements of the Earth’s Crust—Subterranean Disturbing Force—Uplifting and Bending of Strata—Denudation and its Causes—Fossil Remains—their Value in Geological Theory, | 30 | | CHAPTER II. | | THEORY OF DENUDATION ILLUSTRATED BY FACTS. | | Principle of Reasoning common to all the Physical Sciences—This Principle applicable to Geology—Carbonic Acid an Agent of Denudation—Vast Quantity of Lime dissolved by the Waters of the Rhine and borne away to the German Ocean—Disintegration of Rocks by Frost—Professor Tyndall on the Matterhorn—Running Water—its Erosive Power—an active and unceasing Agent of Denudation—Mineral Sediment carried out to Sea by the Ganges and other great Rivers—Solid Rocks undermined and worn away—Falls of the Clyde at Lanark—Excavating Power of Rivers in Auvergne and Sicily—Falls of Niagara—Transporting Power of Running Water—Floods in Scotland—Inundation in the Valley of Bagnes in Switzerland, | 47 | | CHAPTER III. | | THEORY OF DENUDATION—FURTHER ILLUSTRATIONS. | | The Breakers of the Ocean—Caverns and Fairy Bridges of Kilkee—Italy and Sicily—The Shetland Islands—East and South Coast of Britain—Tracts of Land swallowed up by the Sea—Island of Heligoland—Northstrand—Tides and Currents—South Atlantic Current—Equatorial Current—The Gulf Stream—its Course described—Examples of its Power as an Agent of Transport, | 61 | | CHAPTER IV. | | THEORY OF DENUDATION—CONCLUDED. | | Glaciers—their Nature and Composition—their unceasing Motion—Powerful Agents of Denudation—Icebergs—their Number and Size—Erratic Blocks and loose Gravel spread out over Mountains, Plains, and Valleys, at the Bottom of the Sea—Characteristic Marks of moving Ice—Evidence of ancient Glacial Action—Illustrations from the Alps—from the Mountains of the Jura—Theory applied to Northern Europe—to Scotland, Wales, and Ireland—The Fact of Denudation established—Summary of the Evidence—This Fact the first Step in Geological Theory, | 71 | | CHAPTER V. | | STRATIFIED ROCKS OF MECHANICAL ORIGIN—THEORY DEVELOPED AND ILLUSTRATED. | | Formation of Stratified Rocks ascribed to the Agency of Natural Causes—This Theory supported by Facts—The Argument stated—Examples of Mechanical Rocks—Materials of which they are composed—Origin and History of these Materials traced out—Process of Deposition—Process of Consolidation—Instances of Consolidation by Pressure—Consolidation perfected by Natural Cements—Curious Illustrations—Consolidation of Sandstone in Cornwall—Arrangement of Strata explained by intermittent Action of the Agents of Denudation, | 87 | | CHAPTER VI. | | STRATIFIED ROCKS OF MECHANICAL ORIGIN—FURTHER ILLUSTRATIONS. | | Impossible to witness the Formation of Stratified Rocks in the Depths of the Ocean—On a small scale Examples are exhibited by Rivers and Lakes—Alluvial Plains—their extraordinary Fertility—Great Basin of the Nile—Experiments of the Royal Society—The Mississippi and the Orinoco—Some Rivers fill up their own Channels—Case of the River Po—Artificial Embankments—Large Tract of Alluvial Soil deposited by the Rhone in the Lake of Geneva—Deltas—The Delta of the Ganges and Brahmapootra—Delta of the Nile, | 100 | | CHAPTER VII. | | STRATIFIED ROCKS OF CHEMICAL ORIGIN. | | Chemical Agency employed in the Formation of Mechanical Rocks—But some Rocks produced almost exclusively by the Action of Chemical Laws—Difference between a Mixture and a Solution—a Saturated Solution—Stalactites and Stalagmites—Fantastic Columns in Limestone Caverns—The Grotto of Antiparos in the Grecian Archipelago—Wyer’s Cave in the Blue Mountains of America—Travertine Rock in Italy—Growth of Limestone in the Solfatara Lake near Tivoli—Incrustations of the Anio—Formation of Travertine at the Baths of San Filippo and San Vignone, | 109 | | CHAPTER VIII. | | STRATIFIED ROCKS OF ORGANIC ORIGIN—ILLUSTRATIONS FROM ANIMAL LIFE. | | Nature of Organic Rocks—Carbonate of Lime extracted from the Sea by the Intervention of minute Animalcules—Chalk Rock—its vast Extent—supposed to be of Organic Origin—A Stratum of the same kind now growing up on the Floor of the Atlantic Ocean—Coral Reefs and Islands—their general Appearance—their Geographical Distribution—their Organic Origin—Structure of the Zoophyte—Various Illustrations—Agency of the Zoophyte in the Construction of Coral Rock—How the sunken Reef is converted into an Island—and peopled with Plants and Animals—Difficulty proposed and considered—Hypothesis of Mr. Darwin—Coral Limestone in the solid Crust of the Earth, | 118 | | CHAPTER IX. | | STRATIFIED ROCKS OF ORGANIC ORIGIN—ILLUSTRATIONS FROM VEGETABLE LIFE. | | Origin of Coal—Evident Traces of Plants and Trees in Coal Mines—Coal made up of the same Elements as Wood—Beds of Coal found resting upon Clay in which are preserved the Roots of Trees—Insensible Transition from Wood to Coal—Forest-covered Swamps—Accumulations of Drift Wood in Lakes and Estuaries—Peat Bogs—Beds of Lignite—Seams of pure Coal with half Carbonized Trees, some lying prostrate, some standing erect—Summary of the Argument hitherto pursued—Objection to this Argument from the Omnipotence of God—Answer to the Objection, | 141 | | CHAPTER X. | | FOSSIL REMAINS—THE MUSEUM. | | Recapitulation—Scope of our Argument—Theory of Stratified Rocks the Framework of Geological Science—This Theory brings Geology into Contact with Revelation—The Line of Reasoning hitherto pursued confirmed by the Testimony of Fossil Remains—Meaning of the Word Fossil—Inexhaustible Abu
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