FIRST BOOKS OF -.NATURAL HISTORY. 
 
 ELEMENTS OF GEOLOGY 
 
 PRP:PARED FOR THE USE OF 
 
 SCHOOLS AND COLLEGES, 
 
 ELLIOT, 
 
 FOURTH STREET. 
 
 1845. 
 
 W. S. W. RUSCHENBFTIGER, M.D. 
 
 I, LOW OF THE COLLEGE OF PHYSICIANS ; HOS. l| 
 UA MEDICAL SOCIETY; MEMBER OF THE 
 .\L SCIENCES OF iT: L, ETC , ETC. 
 
 MILNE EDWARDS AND ACHILLE COMTE, 
 
 PROFESSORS OF NATURAL HISTORY- IN THE COLLEGES 
 
 OF HENRI IV., AND CHARLEMAGNE. 
 
 : 
 
UNIVERSITY OF CALIFORNIA. 
 
 FROM THE LIBRARY OF 
 
 DR. JOSEPH LECONTE, 
 
 GIFT OF MRS. LECONTE. 
 No. 
 
 
 
Geology. 
 
RXJSCHENBERGER'S SERIES. 
 
 FIRST BOOKS OF NATURAL HISTORY, 
 
 ELEMENTS OF GEOLOGY: 
 
 PREPARED FOR THE USE OP 
 
 SCHOOLS AND COLLEGES, 
 
 BY 
 
 W. S. W. RUSCHENBERGER, M.D. 
 
 SURGEON IN THE U. S. NAVY ; FELLOW OF THE COLLEGE OF PHYSICIANS OF 
 
 PHILADELPHIA ; OF THE COLLEGE OF PHYSICIANS AND SURGEONS OF THE 
 
 UNIVERSITY OF THE STATE OF NEW YORK J HON. MEMBER OF THE 
 
 PHILADELPHIA MEDICAL SOCIETY J MEMBER OF THE ACADEMY 
 
 OF NATURAL SCIENCES OF PHILADELPHIA J CORRESPONDING 
 
 MEMBER OF THE AMERICAN INSTITUTE, ETC. ETC. 
 
 FROM THE TEXT OF 
 
 F. S. B E U D A N T, 
 
 .OYAL ACADEMY OF SCIENCES J INSPECTOR 
 OF STUDIES, ETC. 
 
 MILNE EDWARDS, AND ACHILLE COMTE, 
 
 OF THE ROYAL ACADEMY OF SCIENCES J INSPECTOR GENERAL 
 OF STUDIES, ETC. 
 
 WJCTH THREE HUNDRED E 
 
 PHILADELPHIA : 
 GRIGG & ELLIOT, 
 
 NO. 9 NORTH FOURTH STREET. 
 
 1846. 
 
Entered, according to the Act of Congress, in the year 1843, by 
 W. S. W. RUSCHENBERGER, M.D., 
 
 in the clerk's office of the District Court of the United States in and for the 
 Eastern District of Pennsylvania. 
 
 J. Fagan, btereotyper. 
 
 T. K. & P G^ Collins, Printers. 
 
 (4) 
 
PREFACE 
 
 THE eighth in the series of " First Books of Natural History," 
 comprises the Elements of Geology. 
 
 The volume has been compiled chiefly from the work of F. S. 
 Beudant, and that of Milne Edwards, and Achille Cornte. The 
 works of other writers have been consulted, and freely used ; 
 amongst them, Ansted, Lyell, Mantel, Murchison, Trimmer, Buck- 
 land, Bakewell, De la Beche, Lea, Parkinson, Phillips, Dana, 
 Percival, Charles T. Jackson, Henry D. Rogers, Morton, Conrad, 
 &c., &c. 
 
 The numerous illustrations, to the execution of which we par- 
 ticularly invite attention, were engraved by MR. G. THOMAS, of 
 Philadelphia. We believe better wood-cuts have never been 
 engraved in the United States for any work of the kind, and as a 
 sample of the art, they are creditable to our country. 
 
 The explanations and etymologies of technical words are given 
 as they occur, either in the text, or in foot-notes ; and in many, if 
 not in all cases, the pronunciation of these words has been indi- 
 cated by accents. An ample glossary, which will be found suffi- 
 ciently copious for the general reader, is also appended. When it 
 occurs, the Greek omega has been marked thus (d), and italics 
 have been substituted for Greek characters, because, it is presumed, 
 many who may use this volume are unacquainted with the dead 
 languages. 
 
 It is believed this small volume contains all that is requisite for 
 acquiring a knowledge of the Elements of Geology, except the 
 desire and consequent labour of the student, essential elements in 
 the acquisition of knowledge of every kind. Without labour, 
 knowledge cannot be obtained ; to reach the goal, the road must 
 be travelled, no matter how smooth and easy it may be made ; there 
 
 11 101308 (5) 
 
VI PREFACE. 
 
 is no royal path to learning. When the student is master of the 
 information contained in this book, he will be fully prepared for 
 reading, advantageously, voluminous treatises, and the various 
 geological reports and papers almost daily issuing from the press. 
 
 All knowledge is necessarily communicated from one person to 
 another, through the medium of words, or signs. When branches, 
 or parts of knowledge, or ideas, become familiar and common, the 
 words representing them cease to be difficult. Then the complaint 
 about " hard words" ceases. Few persons acquainted with the 
 instruments, complain that the words Thermometer, or Barometer, 
 are " hard ;" the first is familiar to all, even to those ignorant of its 
 construction and numerous practical uses. The names Quadrant 
 and Sextant are not " hard words" to the most unlettered seaman, 
 and we may remark, in passing, that the science of navigation 
 would not be rendered of more easy acquisition, if those instru- 
 ments were designated by the more familiar names of Bob and Bill. 
 The votary of music does not find the numerous terms, such as 
 clef, minim, semibreve, crotchet, or sonata, overture, aria, or 
 pianissimo, crescendo-, forte, &c., obstacles in acquiring a know- 
 ledge of the science. The same is true of all human sciences. 
 Each has its technicalities and significant names, which cannot be 
 changed without injury, or taken away without increasing the 
 difficulties of acquiring knowledge. 
 
 The names and terms employed in Natural History are very 
 numerous, but most of them are very significant and appropriate. 
 [t is true, some are of doubtful or remote meaning, and might have 
 been better. The fashion of naming natural objects after dis- 
 tinguished individuals, might be safely abandoned. All who are 
 so fortunate as to discover a new genus, or species, should carefully 
 select a name for it significant of some prominent quality or attri- 
 bute, so that the generic and specific names would be together 
 descriptive, as far as possible, of the object. 
 
 Hard names are no real obstacles to the acquisition of science, 
 and no benefit would arise by departing from systematic nomencla- 
 ture in elementary works. One great object of such works, is to 
 explain the meaning of the names and terms employed. Nursery, 
 or "baby talk," does not facilitate a child in learning to speak, or 
 in acquiring ideas ; nor would the study of geology be facilitated 
 
PREFACE. Vll 
 
 by analogous language. Probably Natural History has been made 
 less interesting in our country, and has been less beneficially 
 studied, in consequence of attempts to employ old words, already 
 appropriated to well-known things, to designate new objects. 
 
 The writer trusts the above remarks will be sufficient to meet 
 the objections of all those who cavil about " hard words." 
 
 Besides being in itself very interesting, forming as it were the 
 blossom and bloom of Natural History, a knowledge of zo'ology 
 and botany being necessary to the study and recognition of animals 
 and plants in the fossil state, Geology is practically useful in a 
 high degree. To agriculture, and many of the mechanic arts, it 
 is of great advantage, and it is not totally useless to any avocation 
 or pursuit. A competent knowledge of Geology better enables the 
 architect to select materials for buildings, as well as sites for their 
 erection ; the engineer learns from it where he may run a railroad 
 or canal with the greatest facility, and least cost; the miner is 
 guided in the pursuit of mineral wealth, metals, or coal, with 
 greater certainty of success when assisted by this noble science, 
 which is more unerring than witch-hazel or diving rod ; it facili- 
 tates the physician in the study of climate, and opens a wide field 
 to the divine for pointing out the wonders of the creation, and the 
 goodness of God. 
 
 Before its natural history was explored, at a cost of more than 
 two hundred thousand dollars, voted by the Legislature, vast sums 
 of money were spent in vainly hunting for coal-mines in the state 
 of New York. But after the geological surveyors reported that 
 no coal could ever be discovered in the districts they had examined 
 (because the several formations constituting the surface of these 
 districts were those which are naturally below the coal-bearing 
 series), these wasteful speculations were abandoned, although per- 
 sons unacquainted with Geology complained that, "not satisfied 
 with their inability to find coal themselves, the surveyors had 
 decided that no one else would ever be able to detect any, having 
 had the presumption to pass sentence of future sterility on the 
 whole land," But time will show there was no presumption or 
 guess, but the sentence of the geologists was a positive deduction 
 from their science a deduction that has saved thousands of 
 dollars to individuals, who would still seek for coal where it does 
 not exist, were it not for a knowledge of Geology. 
 
Vlll PREFACE. 
 
 In order to study Geology with greater facility and success, 
 schools should be supplied with drawings, representing the principal 
 facts in the science. Also, with some living shells, marine, flu- 
 viatile, and terrestrial ; specimens of coral, turf, and volcanic pro- 
 ducts, all distinctly labelled ; these, after being pointed out, should 
 be left accessible to the pupils. 
 
 To teach them the composition of the crust of the earth, there 
 should be drawings of the different stratifications, and collections 
 of fossils characteristic of the several formations, all distinctly 
 labelled. Where fossils cannot be obtained, casts representing 
 them will serve a good purpose. Specimens of the various crys- 
 talline and sedimentary rocks should form a part of the teacher's 
 apparatus. 
 
 To illustrate the various effects attributable to igneous and 
 aqueous causes, there should be some well-selected specimens, 
 distinctly labelled, of fossil-shells, encri'nites, of echini'deae, of 
 madrepores, &c., in order to compare them with those now existing. 
 Drawings on a large scale, of faults and crevices, of dykes and 
 injected rocks, of basaltic bosses and of erosions attributable to 
 water, should also belong to the school. During and after the 
 lesson referring to a particular part of the subject, these speci- 
 mens and drawings should be exhibited and explained to the pupils. 
 
 U. S. Naval Hospital, ? 
 New York, October 16th, 1845.3 
 
CONTENTS. 
 
 LESSON I. 
 
 GEOLOGY DEFINED. Form of the Earth. Its Surface. Internal heat. 
 Mineralogy denned. Definition of the terra Rock. Formations. 
 Strata. The origin of Strata. Vegetable Earth. Alluvium. Divi- 
 sion of the Formations. Plutonic formations. Neptunian or Strati- 
 fied Rocks. Order of Strata. Temple of Jupiter Serapis. Subsidence 
 and elevation of coasts p. 11 to 20. 
 
 LESSON II. 
 
 ORGANIC REMAINS. Fossils how produced. 
 
 FIRST GEOLOGICAL EPOCH. Primitive Rocks. Granite. Gneiss. Mica- 
 Schist. Argillaceous Schist 
 
 SECOND GEOLOGICAL EPOCH. Transition Formation. Cambrian System. 
 Silurian System. Trilobites and other Animal Remains. Devonian 
 System. Fossil Fishes. Fossils. Limits of the Transition Formation. 
 Strata changed in position by Geological Convulsions p. 21 to 36. 
 
 LESSON III. 
 
 THIRD GEOLOGICAL EPOCH. Secondary Formation. Carboniferous Forma- 
 tion. Old Red Sandstone. Fossils. Coal Formation. Fossils. 
 Extent of Coal Measures. 
 
 FOURTH GEOLOGICAL EPOCH. New Red Sandstone. Fossils. Triassic 
 System. Bunter Sandstein. Muschelkalk. Keuper. Ammonites. 
 Fossils. 
 
 FIFTH GEOLOGICAL EPOCH. Lias or Liassic System. Fossils. Ichthyo- 
 saurus. Pleisiosaurus. Pteroda'ctylus. Oolitic System. Fossils 
 p. 36 to 66. 
 
 LESSON IV. 
 
 SECONDARY FORMATION continued. 
 
 SIXTH GEOLOGICAL EPOCH. Cretaceous Formation. Lower Cretaceous Sys- 
 tem. Fossils. Wealden Deposit. Greensand. Gault. Fossils. 
 Upper Cretaceous System. Fossils. Extent of Cretaceous Formation. 
 Table of Formations p. 66 to 77. 
 
 LESSON V. 
 
 SEVENTH GEOLOGICAL EPOCH. Tertiary Formation. Eocene Beds. Paris 
 Basin. Fossils. Anoplotherium. Paleotherium. Miocene Beds. 
 Dinotherium Lignites. Pliocene Beds Fossils Bone caverns. 
 
 SUPERFICIAL DEPOSITS. Drift. Diluvium. Megatherium. Boulder For- 
 mation. Alluvium. Big Bone Lick. 
 
 EIGHTH GEOLOGICAL EPOCH. Modern Formation p. 77 to 96. 
 
 LESSON VI. 
 
 INFLUENCE OF INTERNAL AGENTS ON THE SURFACE OF THE EARTH. 
 EARTHQUAKES. Description of. Effects of. Changes of level produced 
 
 by. Upheaval and Subsidence. Constant level of Seas. Slow and 
 
 Progressive Subsidence. General Conclusion. 
 
X GEOLOGY. CONTENTS. 
 
 VOLCANIC PHENOMENA. Explosion. Eruption. Island of Saint George.- 
 Monte-Nuovo. Jorullo. Vesuvius. Definition of a Volcano. Sub- 
 marine Eruptions. Volcan of Unalaska. Crater of Elevation. For- 
 mation ef Craters. Effects of Upheaval. Form of Volcanic Islands. 
 Periods in the Formation of a Volcano. Interior of Craters. Kirauea. 
 Solfataras. Volcanic Ashes. Lava Currents. Characters of Lavas. 
 Dykes. Gaseous Volcanic Products. Eruption of Mud. Solid Pro- 
 ducts of Volcanoes. Trachyte. Obsidian. Compact Lavas. Porous 
 Lavas p. 96 to 122. 
 
 LESSON VII. 
 
 INFLUENCE OF EXTERNAL AGENTS ON THE SURFACE OF THE EARTH. Effects 
 of the Atmosphere. Degradation. Effects of Winds. Dunes. Ef- 
 fects of Lightning. 
 
 EFFECTS OF WATER. Dissolving Power. Softening Power. Denudation. 
 Erosion. Effects of weight of Water. Running Waters. Debacle 
 of Lakes. Mud-Torrents. Slope of Torrents and Rivers. Rolled 
 Flints. Transportation by Ice and Glaciers. Action of Waves. De- 
 posits formed by Water. Geysers. Structure of Sedimentary Deposits. 
 Talus. Effects of Transport or Drift. Effects of Oscillation in 
 Waters. Nature of Deposits from Water. Coral Reefs. Polyparia. 
 Peat-Bogs p. 122 to 144. 
 
 LESSON VIII. 
 
 EXPLANATION OF VARIOUS PHENOMENA. Consequences of Central Heat. 
 First effect of Cooling. Warm-Springs. Deposits referable to Sedi- 
 ment. Fresh Water Deposits. Fossils of. Marine Deposits. Fossils 
 of. Carbonaceous Deposits. 
 
 EFFECTS ATTRIBUTABLE TO UPHEAVAL AND SUBSIDENCE. Shell Deposits and 
 Raised Beaches. Submarine Forests. Tracks of Quadrupeds and 
 Birds. Dislocation of Strata. Faults. Crateriform arrangement of 
 Strata. Valleys of Elevation. Upheaval without Dislocation. Dis- 
 tortion of Strata. Origin of Valleys. Valleys from Dislocation from 
 Subsidence from Folding or Plaiting from Erosion or Denudation. 
 Origin of Caverns p. 144 to 166. 
 
 LESSON IX. 
 
 EXPLANATION OF VARIOUS PHENOMENA CONTINUED. Deposits attributable to 
 Volcanic Action. Lava. Basalt. Action of Basalt on Adjacent 
 Rocks. Dolomisation. Giants' Causeway. Trachytic Formation. 
 Trap Rocks. Porphyry. Granitic Rocks. Injection of Granite. 
 Metalliferous Veins.--Metamorphism.--Effects of Erosion--p. 166 to 181. 
 
 LESSON X. 
 
 CLASSIFICATION OF FORMATIONS. Different kinds of Stratification. Dip. 
 Strike. Conformable Stratification. Unconformable Stratification. 
 False Stratification. The form and habits of an Animal deducible 
 from a single bone. Relative ages of the principal catastrophes of the 
 Globe. Systems of Upheaval. Classification of. State of Europe at 
 different epochs of Formation. Deluge Geogeny p. 181 to 210. 
 
 GLOSSARY p. 211 to 235. 
 
OF THE 
 
 UNIVERSITY 
 
 ELEMENftlJF GEOLOGY. 
 
 LESSON I. 
 
 GEOLOGY DEFINED. Form of the Earth its Surface Internal 
 Heat Mineralogy defined Definition of the term Rock 
 Formations Strata The Origin of Strata Vegetable Earth 
 Mluvium Division of the Formations Plutonic Forma- 
 tions Neptunian or stratified Rocks Order of Strata Tem- 
 ple of Jupiter Serapis Subsidence and Elevation of Coasts. 
 
 1. GEO'LOGY (from the Greek, ge, the earth, and logos, dis- 
 course), or science of the earth, is that branch of Natural History 
 which treats of the physical constitution of our globe. 
 
 2. The earth, as is generally known, is in form of a ball, or 
 spheroid, slightly flattened at the poles, floating freely in space. 
 Its diameter is about 8000 miles, and its surface is irregular; here 
 it is studded with long chains of mountains, there hollowed by 
 deep depressions ; but these inequalities, however gigantic they 
 may appear, when compared with objects surrounding us, are in 
 reality very trifling, in comparison with the mass of the globe ; 
 they are proportionally much less than those we see on the skin 
 of the smoothest orange, and if represented on a ball three feet in 
 diameter, the highest mountains would be still so small as almost 
 to require a microscope to perceive them. 
 
 3. The deepest excavations of the surface of the globe are 
 covered by great masses of water which conceal them and prevent 
 their examination ; but there is reason to believe that the most pro- 
 found depressions do not much exceed three miles in depth, below 
 the surface of the sea, and we know by exact measurement that 
 the summit of the loftiest mountains is not six miles above the 
 same level. 
 
 Mont Blanc, the highest mountain in Europe, is 15,748 feet; Mont Perdu, 
 of the Pyrenees, is 11,168 feet; Peak of Teneriffe, 12,172 feet; in South 
 America, in the Cordillera of the Andes, there are still higher mountains ; 
 
 1. What is Geology ? 
 
 2. What is the form of the earth ? What is its size? What is the cha- 
 racter of its surface ? 
 
 3. What is the greatest depth of the sea ? What is the greatest height 
 of land above the level of the sea ? 
 
 (11) 
 
12 INTERNAL HEAT OF THE EARTH. 
 
 Chimborazo, 21,440 ; Illimani, 24,450 feet ; and Scrota, 25,000. The high- 
 est mountain in the world is in Asia, the Himalaya, which rises 26,862 feet 
 above the level of the sea. 
 
 4. The surface of the earth has not always possessed the same 
 configuration that it now presents ; it has been frequently upturned, 
 and there is even reason to believe that the entire globe was a 
 liquid mass, melted by heat, and that it gradually became solid as 
 it cooled. 
 
 5. Except at comparatively shallow depths, we cannot examine 
 the nature of the materials constituting our globe, not even by 
 descending into mines, excavated for the purpose of extracting the 
 wealth they contain ; for the deepest of these excavations do not 
 exceed 500 yards. But by calculations, it has been inferred that 
 the centre of the earth cannot be occupied, either by water, or by 
 vapour, but by matter as heavy as our heaviest metals, and so hot 
 that it is probably in a state of constant fusion. 
 
 6. A great number of facts concur in proving that the earth 
 possesses an internal heat (the remnant of its original heat), inde- 
 pendent of that which it receives from the sun. Its temperature 
 increases in proportion as we descend to considerable depths ; 
 there are some very deep mines in which the workmen can only 
 labour when naked, and wherever the water of a spring rises from 
 a great depth, its temperature is always very high. This increase 
 of temperature has even been measured, and it has been ascer- 
 tained that the heat of the earth increases about two degrees, Faren- 
 heit, for every 70 to 100 feet. In very deep cellars, where the 
 influence of the seasons is not felt, and where the temperature is 
 always the same, the thermometer, at Paris, stands at about 51 
 degrees, and at a depth of 200 feet below these cellars the heat is 
 about 55 degrees ; at a league below the surface, the temperature 
 must be above that of boiling water, and at a depth of less than 
 two leagues, it must be sufficient to melt tin. 
 
 7. It appears to be demonstrated, that the globe, at some remote 
 period, was in a state of incandescence, or liquefaction from heat, 
 and that it cooled by degrees ; but we must not conclude that this 
 cooling process has continued to the present time, and is still going 
 forward ; it has almost, if not entirely, ceased. From the earliest 
 records of history, to the present moment, the temperature of the 
 
 4. Has the surface of the earth always been the same in form and shape 
 as it now is ? Is it supposed that the globe has always been in its present 
 condition ? 
 
 5. What occupies the centre of the earth ? 
 
 6. Is the temperature of the earth the same at its centre as it is on the 
 surface ? What reasons lead us to the conclusion that the earth possesses 
 an internal heat? 
 
 7. Is it supposed that the earth is becoming cooler and cooler every day ? 
 How is the earth enabled to preserve its temperature ? 
 
STRATIFICATION. 13 
 
 globe has not sensibly changed, and by the calculations of the 
 learned, it is proved that the surface of the earth receives from the 
 sun during a year a quantity of heat equivalent to that which it 
 loses in the same space of time ; the internal heat of the earth no 
 longer influences the temperature of its surface, except in an in- 
 sensible degree, and to diminish this influence, which is almost 
 none at all, one-half, would require the lapse of 30,000 years. 
 
 8. Our knowledge of the central portion of the globe is limited 
 to what we have just said of its weight and temperature ; but the 
 solid crust, constituting its surface, has been better studied. 
 
 9. This crust is not formed of a single piece, but is composed 
 of a great number of various materials. The study of these vari- 
 ous substances, particularly, belongs to Mineralogy ; the study of 
 their mutual relations and the more or less important part they 
 play in the constitution of the globe, is the province of Geology. 
 
 10. In general we give the name of rocks to mineral substances, 
 which are united in great masses, and apply the term formations, 
 to diverse assemblages of rocks which appear to have been formed 
 under the same circumstances. 
 
 The word rock, as used by geologists, is applicable to all mineral masses, 
 whether hard or soft, and therefore includes in its meaning, sand, marble, 
 clay, granite, <fcc. 
 
 11. When we examine the sides of mountains, artificial exca- 
 vations, and various other localities favourable to geological studies, 
 we very soon perceive there are a great many different formations, 
 and these formations are in layers or stories reposing one above 
 the other, constituting strata: (plural of stratum, a Latin word, 
 meaning a bed, couch, or layer ; anything spread out or strewed 
 over a surface.) 
 
 12. We can be convinced of this by examining the cuts made 
 through hills for the passage of rail-roads and canals in various 
 parts of the United States. By comparing the different materials 
 composing the earth's crust, the geologist will soon be satisfied that 
 these different rocks, in a majority of instances, are not placed one 
 alongside the other, but cover each other, and form a series of 
 layers, of more or less thickness, comparable to the courses or 
 layers in a mass or wall of mason-work. Gypsum, or plaster of 
 paris, for example, rests upon a stratum of coarse limestone, for, 
 in digging wells in the neighbourhood of Paris, at different points, 
 the coarse limestone is always found below the plaster. This 
 
 8. What do we know relative to the centre of the earth ? 
 
 9. What is the crust of the earth ? Does it consist of one piece ? What 
 is mineralogy ? 
 
 10. What are rocks ? What are formations ? 
 
 11. What is meant by stratum ? 
 
 12. How are rocks placed relatively to each other? 
 
 2 
 
14 STRATIFICATION. 
 
 coarse limestone in its turn covers a stratum of plastic clay ; in 
 many places where the coarse limestone is not very thick, it has 
 been pierced through, and the plastic clay found beneath it. 
 
 13. But it is not necessary to dig wells in order to be certain of 
 the superposition of the different layers formed by these rocks ; it 
 is distinctly seen by examination of the declivities of certain hills, 
 or cuts made through them for the passage of roads, &c. ; for, 
 when the point of contact of two layers is exposed at one of these 
 localities, we may frequently distinguish, without difficulty, the 
 manner in which one of these layers is continued beneath the 
 other. 
 
 14. In other places nothing similar is seen ; the rocks show 
 no trace of stratification, but constitute compact masses, such as 
 granite. 
 
 To form an idea of the manner in which nature has produced 
 these immense earthy layers, we must study the phenomena which 
 are now taking place at different places on the surface of the 
 earth. 
 
 15. The action of rain, of the sun, of frost, and many other 
 causes are constantly tending to change the surface of rocks, even 
 those which are most compact, and to detach fragments from them ; 
 these fragments, more or less divided, are spread out over the sur- 
 face of the soil, mixed with the detri'tus* of plants and animals, 
 and constitute a kind of movable bed, more or less thin, which 
 covers the whole surface of the globe, and bears, commonly, the 
 name of vegetable earth, because it is in this bed that almost all 
 vegetables grow. The mineral substances which enter into its 
 composition are ordinarily sand, clay, or the debris, or remains of 
 calcareous rocks. 
 
 16. When currents of water pass over movable formations, such 
 as we have just mentioned, they take up a portion and convey to 
 a distance the detri'tus and debris of which they are composed. 
 In this way, when the heaped-up snows on the tops of mountains 
 melt under the influence of the summer's sun, or when abundant 
 rains fall on the same places, impetuous torrents descend towards 
 the plain, and carry with them earth and fragments of stones found 
 in their route, or which they tear up from their resting-places ; the 
 
 * DETRI'TUS. A geological term applied to deposits composed of various 
 substances which have been comminuted by attrition. The larger frag- 
 ments are usually termed debris ; those which are pulverized, as it were, 
 constitute detri'tus. Sand is the detri'tus of siliceous rocks. 
 
 13. What evidence have we of the superposition of strata? 
 
 14. Are all rocks stratified? 
 
 15. What are the common causes which tend to change the surface of 
 rocks ? What is detri'tus ? What is vegetable earth ? What is debris ? 
 
 16. How. do currents of water change the surface of the earth? 
 
DEPOSITION OF SOIL BY RIVERS. 15 
 
 result is that the water of these torrents is often turbid, and loaded 
 with mud, sand, flints, or even blocks of stone ; but when they 
 reach a flat country, or fall into a large basin, their course is much 
 less rapid, and the foreign materials they held in suspension are 
 gradually deposited ; the heaviest sink first, and, at length, these 
 materials line the bottom of the river with an earthy bed, whose 
 thickness is continually increasing. 
 
 17. The river Po, which is precipitated from a lofty chain of the 
 Alps, and traverses Lombardy, is a remarkable example of this 
 curious phenomenon. This river, and its principal tributaries, 
 have transported, in this way, so much earthy matter from the 
 mountains to the plain, that, since the Roman era, several large 
 lakes and extensive marshes, situated near Parma, Paisance, Cre- 
 mona, &c., have been filled up and become dry : the bed of these 
 rivers is also gradually filled up, so that they have several times 
 changed their course, and poured over the neighbouring plains. 
 It has been necessary to restrain them artificially, by building up 
 a long dyke on each bank ; this has put an end to these disastrous 
 inundations, but has not prevented the bottom of the river from 
 continuing to rise up ; every year it is therefore necessary also to raise 
 up the dykes, so that now these rivers flow in a sort of immense 
 aqueduct, and at certain places the surface of their waters is higher 
 than the roofs of the surrounding houses, as at Ferrara, for ex- 
 ample. 
 
 18. The river Rhone descends on the northern side of the Alps, 
 and passes the Valais too impetuously to deposit the mud and flints 
 with which it is abundantly freighted ; but, when it empties into 
 the lake of Geneva^ its course becomes so slow as to be almost 
 imperceptible, and its waters, which were at first turbid and muddy, 
 are limpid and transparent, when they escape from the opposite 
 side of this basin to pass through the town of Geneva : the result 
 is that the Rhone deposits in this basin all the matters which it 
 carried, and gradually raises up its bottom, constituting what is 
 termed lacustrine formation. This progressive elevation of the 
 soil is so marked at the eastern extremity of the |^.ke, that an an- 
 cient town called Port Valais, formerly situated on its margin, is 
 now found about a half a league from it ; about eight centuries 
 have been sufficient for the formation of the great earthy bank 
 which now separates this town from the lake, and the deposite 
 which gave rise to it continues to be made at the bottom of that 
 portion of the lake in its vicinity, and continually tends to raise it 
 up more and more, so that in time it may fill the whole of this 
 basin, and transform the lake into a plain which the Rhone will 
 pass through without spreading itself. In passing through Geneva, 
 
 17. Give an example of change produced by currents. 
 
 18. What has been the effect of the Rhone passing through the lake of 
 Geneva ? What is meant by lacustrine formation ? 
 
16 ALLUVIUM DELTAS. 
 
 this beautiful river, as we have already said, is clear and limpid ; 
 but a little beyond the town it receives new tributaries, such as the 
 Arve, which pour into it their muddy waters, and little by little it 
 is again loaded with sand and rnud, which it rolls on impetuously 
 to the sea ; but at its mouth, its course being slow, these foreign 
 materials, the debris of Mont Blanc, of the Alps, of Dauphiny, 
 and the central regions of France, are in their turn deposited, and 
 gradually elevate the soil they cover ; the result is new land which 
 advances more and more on the sea. 
 
 19. We give the name of alluvium (from the Latin, alluvio, an 
 inundation, or alluo, I wash) to formations caused in this way by 
 the deposite of materials carried by waters, and as these alluvial 
 formations, when deposited at the mouth of a river, often assume 
 the form of the Greek letter A delta, we designate the new-made 
 land, which in a manner encroaches on the domain of the sea, 
 under the name of delta. 
 
 20. The delta of the Rhone, to which we alluded above, and 
 that which is found at the mouth of the Po, are very inconsider- 
 able ; but, in certain parts of the globe, several are found of very 
 much greater geological importance. One of the most celebrated 
 is the Delta of the Nile, which, according to the calculations of 
 some authors, must have grown nearly half a league since the 
 time of Herodotus ; and according to the commonly received 
 opinion, its formation began at the foot of the rocks upon which- 
 were built the pyramids of Memphis ; but the deltas at the mouth 
 of the Mississippi, and the mouth of the Ganges, increase more 
 rapidly, and possess greater interest for the naturalist. 
 
 21. Other formations are also produced, so to speak, under our 
 eyes, by the deposite of materials which the waters of certain 
 springs hold in solution, and throw down when they reach the sur- 
 face of the earth. In different parts of France, near a spring 
 situated at the north of Clermont Ferrand, for instance, we see 
 examples on a small scale, and in many parts of Italy, enormous 
 masses of calcareous stone, known under the name of Travertin 
 (from the Italian, travertine], are formed. 
 
 22. We often behold issuing from the craters of volcanoes, a 
 burning, semi-liquid matter, which spreads over the surface of the 
 neighbouring country, and, on cooling, is converted into a hard 
 compact rock, called lava. Etna has furnished a great number of 
 irruptions of lava, one of which was six leagues in length, and, in 
 1783, Hecla, a volcano of Iceland, gave origin to a similar cur- 
 rent, which extended twenty leagues in length, arid twelve in 
 breadth. 
 
 19. What is alluvium ? What is a Delta ? 
 
 20. Mention some examples of Deltas. 
 . 21. What is Travertin ? 
 
 2ii, What is lava ? 
 
AQUEOUS AND PLUTONIC FORMATIONS. 17 
 
 23. These different phenomena partly explain to us the manner 
 in which the production of the different formations disseminated 
 on the surface of the globe, must have been effected, formations 
 whose origin date back from an epoch long anterior to that of the 
 creation of man. 
 
 24. In fact, the various formations constituting the common por- 
 tion of the globe differ, as we have already seen, very widely in 
 their nature, in their constitution, and in their mode of arrange- 
 ment. Now, these differences remind us of those which exist in 
 the modern formations above mentioned, and seem to indicate that, 
 in the ancient formations, some were produced in the midst of the 
 waters by the deposit of solid materials held in suspension or in 
 solution by this liquid, and others by the action of heat on earthy 
 materials susceptible of being melted, and of being afterwards 
 hardened by cooling. 
 
 25. Guided by these considerations, geologists have divided the 
 formations into two great classes ; namely, the sedimentary, or 
 stratified formations, and the massif or igneous formations. 
 On account of the presumed method of their production, they are 
 also designated under the names of Aqueous or Neptunian for- 
 mations, and Igneous or Plutonic formations. 
 
 ' 26. The plutonic formations have received this name because 
 they appear to be the product of the action of fire ; they are 
 generally of a dense crystalline structure, and ordinarily form very 
 immense masses ; they are not arranged in regularly superposed 
 beds, nor do they contain the remains of organized bodies. Some 
 of them are formed, as we see, by the action of volcanoes, and 
 others are very analogous to the latter; they contain not only 
 minerals peculiar to volcanic ejections, but sometimes also matters 
 that are produced by the furnaces of our laboratories and Work- 
 shops. They seem to have 'formed the primitive crust of the 
 globe; for we find them beneath the neptunian formations, but 
 they are also sometimes spread over the surface of the latter, or 
 betwixt the different beds or strata of which they are composed. 
 
 27. The aqueous or neptunian formations appear to have been 
 deposited by the waters ; in general their texture is coarse or com- 
 pact, rarely crystalline, and they are often composed of grains of 
 sand separate or agglutinated, of heterogenous fragments, or ma- 
 terial having the aspect of a kind of indurated mud ; they are also 
 frequently called stratified formations, and most of them are also 
 termed SEDIMENTARY FORMATIONS. It is in the midst of these for- 
 
 23. Are the various formations all of the same age ? 
 
 24. In what manner were the various formations produced ? 
 
 25. How are the formations divided ? 
 
 26. What is meant by plutonic formations ? How are they produced ? 
 
 27. How were the aqueous formations produced ? What are the charac- 
 ters of aqueous rocks ? 
 
 2* 
 
18 ORDER OF STRATA. 
 
 mations that we find the remains of the different organized bodies 
 by which the earth has been successively peopled. 
 
 28. These stratified formations were not all produced at once, 
 but successively, and under the influence of different circumstances ; 
 they constitute, as we have before said, distinct beds or strata, 
 and these strata lie one on top of the other, so that those of a more 
 ancient are found beneath those of a more recent formation. By 
 studying them carefully we shall also perceive that different points 
 on the surface of the earth have been successively, and at intervals, 
 left dry, and covered by the waters of the sea, or by fresh water, 
 the sediment from which constitutes these banks, and we see that 
 these banks themselves differ, not only in the nature and disposi- 
 tion of their constituting elements, but also in the nature of the 
 remains of the organic bodies buried in their substance. 
 
 29. We distinguish a great number of these stratified forma- 
 tions, and, as might be anticipated from their mode of production, 
 they are everywhere found in the same order of superposition ; 
 the formation which, in one locality, covers another formation, can 
 never be found in another place beneath the latter; it may be 
 entirely wanting, so as to leave the latter uncovered, or in contact 
 with a stratum, which in another place it covered ; but wherever 
 it exists, it must be on top of or superior to all formations, the pro- 
 duction of which dates back to a more remote epoch. 
 
 30. For example, we have stated that in -the vicinity of Paris, the 
 gypsum rests upon the coarse limestone, this upon the plastic clay, 
 and this plastic clay upon the chalk; in other localities we may 
 find new strata interposed between these various formations, or we 
 may find one of them entirely wanting ; for example, the plastic 
 clay being absent, the coarse limestone would be found resting 
 directly upon the chalk; but this coarse 'limestone, for the reason 
 alone that it is everywhere found resting upon the chalk, must have 
 been deposited after the chalk was formed, and consequently can 
 never be found below it. 
 
 31. It is also evident that when these solid beds are slowly 
 
 Sea. 
 
 Sedimentary Rocks. 
 Plutonic Rocks. 
 Fig. 1. 
 
 28. Were the stratified formations all produced at the same time ? Are 
 all the stratified rocks alike in character ? 
 
 29. Are the stratified formations always found in the same order of suc- 
 cession ? Are all the strata everywhere found ? 
 
 30. Give an example to show that the strata are always found in the sama 
 order of succession. 
 
 31. What is the position of sedimentary rocks ? 
 
MOVEMENTS OF STRATA. 19 
 
 deposited at the bottom of waters, they must have a nearly hori- 
 zontal position (Jig. 1), and that they must occupy the steepest 
 parts of the surface upon which they are formed, so that if the 
 surface presents considerable elevations, these may remain un- 
 covered, and show themselves above the level occupied by the 
 new formation (Jig. 2). Thus when we go from low plains 
 
 Fig. 2. 
 
 towards mountain chains, and ascend to their summits, we meet, 
 successively, formations more and more ancient as we rise. 
 
 32. Sometimes these stratified rocks preserve the horizontal 
 position they had in the beginning ; but at other times they become 
 more or less oblique in consequence of their partial depression or 
 sinking, or their unequal elevation. Frequently we see beds 
 which are abruptly raised up, so as to be almost perpendicular ; 
 and on the edges of the elevation produced by this overturning of 
 nature, we find other beds which are perfectly horizontal, and we 
 may conclude that the latter were formed subsequently to the ele- 
 vation of the former ; by studying these relations of position we 
 are enabled to determine the geological age of mountains. 
 
 33. These great movements of strata sometimes take place sud- 
 denly, and are accompanied by earthquakes ; but at other times 
 they are effected gradually and without any shock. It appears to 
 be well ascertained that since the time of the Romans, a portion 
 of the coast of Naples sank below the level of the sea, and was 
 subsequently raised up again above this level, without overturning 
 the monuments built on this movable soil. One may be satisfied 
 of this fact by visiting an ancient temple situated near Puzzuoli, 
 called the Temple of Jupiter Serapis ; this monument, of which 
 three columns remain standing erect, appears to have been built in 
 the third century, and was then very much frequented, on account 
 of its warm baths ; but at a subsequent epoch, supposed to be about 
 1488, the ground sank down, and the temple was covered by the 
 
 32. Do stratified rocks always preserve their original position ? What is 
 to be learned by studying the position of strata ? 
 
 33. How do these great movements of strata take place ? Give an in- 
 stance of the gradual movement of strata. 
 
20 
 
 ELEVATION OF COASTS. 
 
 Fig. 3. Temple of Serapis. 
 
 sea to a height of about six- 
 teen feet above the pavement. 
 Marine animals then establish- 
 ed themselves on a portion of 
 the submerged columns, and 
 mollusks of the genus Pholas 
 excavated innumerable holes 
 in the same way as they do 
 rocks now covered by the sea ; 
 but in the present day the state 
 of things is not the same, the 
 pavement of the temple is again 
 dry, and the traces of the pho- 
 lades we have just mentioned 
 are at a considerable height 
 above the level of the sea (Jig. 
 3). Now, these changes in the 
 relative -levels of the coast of 
 Puzzuoli, and the neighbour- 
 ing sea, cannot be attributed 
 to an alternate sinking and rise 
 of the waters, because move- 
 ments of this sort must have been accompanied by fearful inun- 
 dations along the shores of the Mediterranean, and we cannot ex- 
 plain this phenomenon except by supposing that the coast itself, 
 after sinking, was again gradually raised up. 
 
 34. At the present time Scandinavia and Chile exhibit an 
 analogous phenomenon. On the coasts of Sweden, for example, 
 we see certain rocks, which were formerly submerged, now above 
 water, and that the steep shore is gradually rising more and more 
 above the level of the sea. For a long time it was observed that 
 the sea abandoned certain parts of the coast, and that the depth of 
 water decreased in several ports of this region ; but these changes 
 of level have been ascertained in a more exact manner; more than 
 a century since, marks were made on different rocks on a line with 
 the surface of the water, to serve as points of comparison, and on 
 examining them from year to year, it was found that these marks 
 were successively higher and higher above the level of the sea. 
 In the gulf of Bothnia, this rise appeared to be four feet in a 
 century, but at other places less, and at some points on the coasts 
 of the Baltic, it was nothing, which proves that the change of level 
 does not depend on the subsidence of the sea. 
 
 We shall recur to the subject of stratification and the various 
 causes which influence it, after we have studied the characters of 
 the various formations. 
 
 34. What other instances prove the slow movement of strata ? 
 
ORGANIC REMAINS. 21 
 
 LESSON II. 
 
 ORGANIC REMAINS. Fossils How produced. 
 
 FIRST GEOLOGICAL EPOCH. Primitive Rocks Granite Gneiss 
 Mica- Schist Argillaceous- Schist. 
 
 SECOND GEOLOGICAL EPOCH. Transition Formation Cambrian 
 System Silurian System Trilobites and other animal 
 remains Devonian System Fossil Fishes Fossils Limits 
 of the Transition Formation Strata changed in Position by 
 geological Convulsions. 
 
 1. We find entombed in the different strata of the crust of the 
 globe a great quantity of the remains of organic bodies, which at 
 different epochs have lived on its surface. Those which exist in 
 the present formations, and which have been deposited since the 
 last great revolutions of the earth, generally preserve their primi- 
 tive composition ; but those which have been found in the more 
 ancient strata have be^i altered in their nature, and passed into 
 the fossil state; the gelatinous, fleshy, or ligneous portions, which 
 concurred in their formation, have in part disappeared, and have 
 been more or less replaced by stony particles. By the term fossil 
 (formed from the Latin, fodio, I dig) is meant any organic body, 
 or the traces of any organic body, whether animal or vegetable, 
 which has been buried in the earth by natural causes. 
 
 2. Tn general, it is the hard parts, those that are capable of long 
 resisting decomposition, which alone undergo this kind of altera- 
 tion ; such as bones, shells, and scales, for example. We never 
 find flesh, nor nails, nor soft fruits, nor other analogous bodies, in a 
 fossil state. Sometimes even these hard bodies disappear, and 
 leave merely traces of their existence in an impression or print in 
 the rock that enveloped them. 
 
 3. The organic remains which are found in the most superficial 
 and most recent strata of the crust of the earth, belong in part to 
 species which still exist; but most fossils are derived from ani- 
 mals or plants which have not existed since a period anterior to 
 
 1. In what respects do the organic remains found in the most ancient 
 formations differ from those found in the more modern strata ? What is 
 meant by the term fossil ? 
 
 2. What parts of organized bodies are found in the fossil state ? 
 
 3. Are the animals and plants found in the fossil state the same as those 
 now existing on the face of the earth ? Are all the varieties of fossils dis- 
 tributed through the divers strata without regard to the age of the forma- 
 tions ? 
 
22 REVOLUTIONS OF THE EARTH. 
 
 historic times, and the species of which are now totally extinct. 
 In general, they differ from species now living, more and more, in 
 proportion to the antiquity of the strata in which they are found, 
 and, in most of the strata of the earth's crust we find certain 
 species which are not met with either in more ancient or more 
 recent formations. 
 
 4. It is by comparing the fossils with each other, and by com- 
 bining this study with that of the order of superposition, in which 
 the different strata are found, and with their mode of formation, 
 that we have arrived at a knowledge of the earth at periods long 
 anterior to the creation of man, and are enabled to trace the his- 
 tory of the great revolutions which have successively disturbed 
 and changed its surface. 
 
 5. We learn by this study that the physical condition of the 
 surface of the earth, as well as that of the organized beings by 
 which this surface is inhabited, has undergone great and nume- 
 rous changes. Entire creations of animals and of plants have suc- 
 ceeded each other ; after having peopled the waters and inhabited 
 the land for ages, each in its turn has been destroyed by some 
 great catastrophe of nature, and given place to a new creation. 
 But the appearance of a new flora, or a new fauna, the destruction 
 of living beings, and the deposit of enormous beds of rocks, are 
 not the only phenomena which characterifb the great revolutions 
 of the earth. At different epochs, total overthrows, of which the 
 most fearful earthquakes and volcanic eruptions of our times can 
 give but a very feeble idea, have raised up the solid crust of the 
 globe, and produced lofty chains of mountains, whose elevation, 
 immense as it appears to us, was even still greater before the val- 
 leys and basins that separate them were gradually filled by new 
 deposits. 
 
 6. The great revolutions of the earth appear to have been sepa- 
 rated by long periods of tranquillity, during which animals and 
 plants multiplied on different parts of the globe's surface, and de- 
 posits of solid materials, borne by the waters or drawn from the 
 bosom of the earth, were heaped up, constituting beds of rocks of 
 greater or less thickness, and varying in their nature, in the sub- 
 stance of which were entombed the remains of contemporaneous 
 animals and plants. 
 
 7. The natural history of the globe is written in the very rocks 
 of which our planet is composed, and the study of these ancient 
 monuments of the power of the CREATOR teaches us what tran- 
 spired long before the existence of man on the earth. These fos- 
 
 4. By what means do we study the geological history of the earth? 
 
 5. What are the great facts taught by the study of geology ? 
 
 6. What seems to have occurred in the long intervals of tranquillity 
 between the great geological revolutions of the earth ? 
 
 7. Does geology teach us that the earth was always inhabited by man ? 
 
NATURAL REVOLUTIONS. 23 
 
 sils are truly the medals of creation, medals which are more im- 
 portant and incomparably more ancient than all those of Greece 
 and Rome, or the hieroglyphics of Egypt. 
 
 OF THE NATURAL REVOLUTIONS OF THE GLOBE. 
 
 8. The history of the globe, like that of nations, is divided into 
 a certain number of distinct periods., during each of which the 
 state of things changed but little, yet it resembles neither that 
 which preceded nor that which followed after it. 
 
 9. Geologists designate under the term formation, the assem- 
 blage of rocks which were produced during each one of these 
 periods comprised in the interval between two of these revolu- 
 tionary disturbances of the globe. 
 
 10. For example, they give the name of creta'ceous formation 
 (from the Latin, creta, chalk) to the assemblage of rocks which 
 were deposited or derived from the interior of the earth, during a 
 geological epoch, in a part of which chalk was deposited ; and 
 juras'sic formation is the name given to the assemblage of con- 
 temporaneous sedimentary rocks composing the most remarkable 
 strata of the mountains of Jura, &c. 
 
 Beginning with the most ancient, we will examine these several 
 formations in succession. 
 
 FIRST GEOLOGICAL EPOCH. 
 
 Primitive, Primary, Primordeal, or Unstratified Roclcs.* 
 
 11. Under the name of primitive, or primary rocks (from the 
 Latin, primus, first, before), we ordinarily designate the different 
 rocks which appear to have been formed before the creation of 
 plants and animals, the remains of which are found in less ancient 
 strata, and seem to be a foundation for rocks subsequently pro- 
 duced. 
 
 * Mr. Lyell proposes to designate this system of rocks by the term 
 Hypo'gene (from the Greek, vpo, under, and geinomai, I beget), because 
 they are found under other rocks. He objects to the words primary and 
 primitive, because these terms convey a notion as to the time, and age of 
 the formation, and might lead to the error of supposing that they were 
 formed before any other rocks were formed, but the term hypo' gene refers 
 exclusively to position. 
 
 &. How is geological history divided ? 
 9. What is meant by the term formation ? 
 
 10. What is meant by creta'ceous formation? What is meant by juras'- 
 sic formation ? 
 
 11. What is meant by primitive or primary rocks? 
 
24 FIRST GEOLOGICAL EPOCH. GRANITE. 
 
 12. As already stated, at its origin our globe must have been a 
 mass kept in a state of fusion by the action of heat, and its surface 
 became solid by slowly cooling. This first crust must have re- 
 mained for a long time in a soft or pasty condition, and at first its 
 temperature must have been too high to permit water to remain 
 on its surface without evaporating. It must have been split in 
 different directions by the contraction produced by cooling, and 
 then resembled the masses of ice which in our day cover the sur- 
 face of the polar seas ; that is, it presented a very unequal surface, 
 studded with immense fragments heaped up in all directions. In. 
 this first geological epoch were formed the massive rocks, such as 
 granite, which serves as the base of all other rocks, and is the 
 result of the solidification of mineral substances previously melted 
 by heat. The cooling of this first crust must have also caused 
 the precipitation of the least volatile matters diffused in the atmo- 
 sphere, just in the same manner as a cold body placed in a warm 
 moist air is quickly covered by a layer of condensed vapour ; and 
 from this cause came new changes in the configuration of the sur- 
 face of the globe, and the formation of new beds of a crystalline 
 texture. 
 
 13. The most ancient portion of the crust of the earth known 
 to geologists is composed chiefly of granite and some other un- 
 stratified rocks which appear to be also of igneous origin. 
 
 14. We give the name of granite to a rock, which is extremely 
 hard, having a rough fracture, which is composed of a confused 
 agglomeration of crystals formed of three distinct materials : some 
 of these crystals have a glassy appearance, and are ordinarily of 
 a grayish colour ; they are quartz, the same material of which 
 rock crystal is composed ; others, often large, opaque, and some- 
 times rose-coloured, sometimes green, sometimes white or yellow, 
 are formed of a mineral catted f eldspar ; and the third variety of 
 crystals, which are composed of mica, resemble small brilliant 
 spangles, sometimes black, and sometimes silvery white. Granite 
 then consists of quartz, feldspar, and mica. Certain varieties of 
 granite remain for centuries exposed to the inclemencies of the 
 weather without undergoing any alteration ; but other varieties are 
 speedily disintegrated by the action of the atmosphere, and are thus 
 reduced to a kind of grit or argilla'ceous earth. It presents no 
 trace of stratification, and possesses all the characters of a rock of 
 igneous origin. 
 
 12. What is supposed to have been the condition of the earth when first 
 formed? What was the condition of the crust of the earth when first 
 formed ? Was it smooth and regular ? 
 
 13. Of what is the most ancient portion of the crust of the earth com- 
 posed ? 
 
 14. What is granite? Of what minerals is it composed ? What is the 
 character of granite for durability ? 
 
GNEISS, MICA-SCHIST, &c. 25 
 
 15. Granite, which seems to form the first basis, the foundation 
 stone of the great geological edifice, remains uncovered at various 
 points on the surface of the earth, while in other places it is 
 covered by more or less numerous beds of more recent formations. 
 But all the granitic rocks now scattered over the surface of the 
 globe do not date from an antiquity so remote ; for, in different 
 recent epochs, mineral materials in a state of fusion have escaped 
 from the bosom of the earth, which spread over formations then 
 existing, and, on cooling, constituted immense masses of granite 
 similar to that first formed. 
 
 16. This rock is met with in different places in all parts of the 
 xvorld, and is employed in the construction of edifices of various 
 description. 
 
 17. The beds which are deposited on the first massive crust of 
 the globe are crystalline in structure, and this character is more 
 decided the more ancient they are ; they seem to have been ex- 
 posed to the action of a great heat, without possessing the charac- 
 ters of rocks of igneous origin. They consist principally of gneiss, 
 mica-schist, and argillaceous schist. 
 
 IS, Gneiss is a rock very analogous to granite as respects its 
 elementary constituents, but its structure is foliated and presents a 
 stratified arrangement ; it appears to have been formed under wa- 
 ter, and seems to be the most ancient of the sedimentary forma- 
 tions, because in certain places on the surface of the globe we find 
 it covered by all the other formations. We often see it naked ; it 
 forms vast systems of rocks in which it is often alternated with 
 mica-schist and other ancient rocks. It is used in building and 
 
 flagging. 
 19. Mi 
 
 19. Mica-schist is a lamellar rock composed of quartz ordinarily 
 grayish, and a great quantity of brilliant lamellae of mica arranged 
 in extended leaves or scales ; it commonly accompanies granite and 
 gneiss. 
 
 20. Argillaceous schist is in appearance an earthy rock, which 
 is easily divided into large laminae more or less thin, and was evi- 
 dently formed under water by the deposit of sediment. [Schist, 
 from the Greek schistos, slaty, easily split.] 
 
 We also find in these primitive strata compact limestone of great 
 hardness, and other rocks which more or less resemble the pre- 
 ceding. . 
 
 21. These different rocks, the origin of which dates from the 
 
 15. Is granite everywhere hid beneath the surface of the earth? Is all 
 granite supposed to be of the same age ? 
 
 16. Where is granite found ? To what uses is it applied ? 
 
 17. What kind of rocks are found overlying the granite? 
 
 18. What is gneiss ? How does it seem to have been formed? 
 
 19. What are the characters of mica-schist ? 
 20 What is argilla'ceous schist ? 
 
 3 
 
26 SECOND GEOLOGICAL EPOCH. 
 
 earliest period of geological history, constitute a great part of the 
 present surface of the globe, and are often found at great depths, 
 beneath less ancient formations. They present evident traces of 
 great overthrows, and the beds or layers which they form no longer 
 occupy the horizontal position they must have had in the begin- 
 ning, but are more or less inclined, twisted and fractured, as if at 
 various times they had been broken and their immense fragments 
 irregularly raised up. Those countries in which the primitive 
 rocks constitute the surface are knotted and mountainous, and we 
 find these same rocks in the most elevated points of the globe, 
 where they form the mass of most great mountain chains. 
 
 22. The central plane of France, comprising Auvergne, Limou- 
 sin, Vivarais, and Valais, is formed almost entirely of primitive 
 rocks, most of which are granitic. The same is true of a great 
 part of Brittany and Corsica, Scandinavia and Finknd, &c. ; these 
 ancient rocks also constitute a krge part of the Great Alps, of 
 which Mont Blanc is the highest point, the Eastern Alps from 
 Saint Gothard to Hungary, the Pyrenees, the chain of Erzge- 
 berge, in Saxony, the Grampian Hills of Scotland, the Oural 
 mountains, in Russia, the Alleghanies in the United States, and 
 the Andes in South America. 
 
 23. As we have already stated, we find no fossils in the sedi- 
 mentary formations of this geological period, and it is therefore 
 inferred that in this epoch no living beings existed on the surface 
 of the globe ; but it may have been otherwise, and the absence of 
 fossils in these strata depends on some cause, such as their destruc- 
 tion by heat, resulting from their vicinity to enormous masses of 
 igneous rocks, effused near to, or even over and above these non- 
 fossiliferous strata. 
 
 SECOND GEOLOGICAL EPOCH. 
 Transition Formation. 
 
 24. The stratified formations which rest on the primitive strata 
 just mentioned, present us with the first traces of the existence of 
 living beings on the surface of the globe, and constitute a particular 
 division, generally named the Transition Formation, but desig- 
 nated by Mr. Lyell as the Primary Fossiliferous Formation. The 
 most recent name given, however, to these formations, is palaeozoic 
 (formed from the Greek poluios, ancient, and zbon, an animal), be- 
 cause they contain ancient animal remains. 
 
 21. Are primitive rocks found only beneath the more recent formations? 
 
 22. In what countries do we find primitive rocks at the surface ? 
 
 23. What fossils are found in the primitive sedimentary rocks ? 
 
 24. In what formations are fossils first met with ? What is meant by 
 palaB'ozoic formation ? 
 
CAMBRIAN SYSTEM. 27 
 
 25. These formations closely resemble the preceding, and it is 
 often difficult to distinguish them, but they do not appear to nave 
 begun to form until the first had been disturbed by some great 
 geological convulsion ; for the strata of which they are composed 
 are not parallel to those of the rocks on which they rest, and they 
 differ from them by having fossils entombed in their substance. 
 They appear to have been formed by a slow and continuous 
 deposit of sand, mud, and other materials suspended in water, 
 and they consist chiefly of schists and calcareous rocks. The sea 
 seems then to have covered the greatest part of the known surface 
 of the globe, for we scarcely find a trace of terrestrial plants, and 
 immense depots of these strata, almost identical in character, are 
 met with in the most distant parts of the earth, as in Germany, 
 England, and America. 
 
 26. To judge by the fossils concealed in these formations, the 
 globe was then inhabited by a small number of plants, belonging, 
 for the most part, to the family of fucus, and by a multitude of 
 marine animals, the forms of which differed widely from those now 
 existing. It is also remarked that most of these animals belonged 
 to the inferior classes of the animal kingdom, and, until lately, it 
 was believed no vertebrate animal then existed ; but within a short 
 time it has been ascertained there were marine fishes, for remains 
 of them have been discovered in certain rocks whose formation 
 dates back to this remote epoch. (Fig. 20.) 
 
 27. The most ancient beds of the transition formation contain 
 very few fossils, while* other rocks of the same formation are rich 
 in these remains ; these differences, which correspond with other 
 peculiarities of stratification, have led geologists to divide this period 
 into three divisions, called the CAMBRIAN, SILURIAN, and DEVONIAN 
 Systems of rocks. 
 
 28. The CAMBRIAN (from Cambria, in Wales) or SCHISTOSE SYS- 
 TEM. The Cambrian rocks are the lowest sedimentary deposits 
 known. They are composed essentially of schistose grauwackes, 
 which pass through all shades of solidity, lustre and colour ; on 
 one side they unite with the mica-schists and gneiss, and on the 
 other with the coarse grauwackes, with which they are found inter- 
 calated. These rocks contain slate rocks, conglomerates, dark 
 limestone, and fine-grained slates of various shades of purple, blue 
 and green. In the Cambrian rocks the organic remains consist of 
 a few fossil brachiopods, polypa'ria, or coral animals, &c. 
 
 25. How does the palaeozoic formation differ from the primitive rocks ? 
 In what manner were the palae'ozoic formations produced ? 
 
 26. At the period of the palae'ozoic formation, what description of organ- 
 ized beings lived on the earth ? 
 
 27. How is the transition or palae'ozoic formation divided ? 
 
 28. How is the Cambrian System of rocks characterized ? From what 
 is its name derived ? What is the geological position of the Cambrian 
 System ? 
 
28 
 
 SILURIAN SYSTEM FOSSILS. 
 
 29. The SIHJ'RIAN SYSTEM (from the Silures, or Siluri, the an- 
 cient Britons who inhabited the region where these strata are most 
 distinctly developed) is next above the Cambrian, It is subdi- 
 vided into the upper and lower Silurian strata. In its mineral 
 composition it so closely resembles that of the Cambrian that it is 
 often difficult to distinguish them. These strata are entirely of 
 marine origin,' and many of the beds (as the well-known Dudley 
 limestone) are composed of shells, corals, crinoidea, and those pe- 
 culiar crustaceans termed trilobiles (jig. 4), held together by a 
 calcareous cement. 
 
 30. The presence of these fossil animals is characteristic of the 
 Silurian and Devonian Systems of strata, because they are rarely 
 met with in other situations. They are found entombed in slate 
 and dark limestone. 
 
 Trilobitcs, from their extraordinary form and appearance, have, for more 
 than a hundred and fifty years, been objects of great interest to the natu- 
 ralist and of wonder to the general observer, and have long been provin- 
 cially termed Dudley insects or locusts. The most common examples con- 
 sist of a convex, oblong body, divided transversely into three principal 
 parts, and longitudinally into three lobes, by two deep, parallel furrows ; 
 from this last character, by which the family is recognised among natural- 
 ists, the name Trilobite (from the Latin trcs, three, and lobus, lobe) has been 
 derived. These fossils are the carapaces, or shells, of crustaceans, belonging 1 
 to an extinct family, which comprises many genera, and numerous species. 
 
 The class of crustaceans consists of two groups, namely : those with eyes 
 
 * Explanation of Fig. 4. 1 .-A'saphus Caudatus. 2. A'saphus Buchii. 
 3. Caly'mene Blumenbachii. 
 
 29. How is the Silurian System characterized ? How does it differ from 
 the Cambrian System ? What is the origin of its name ? What are tri- 
 lobites ? 
 
 30. Of what systems of rocks are trilobites characteristic ? 
 
FOSSIL REMAINS TRILOBITES. 
 
 29 
 
 supported on movable peduncles, as the crab and lobster, and those with 
 eyes fixed ; the extinct order of trilobites belongs to the last. 
 
 The Caly'mene Blumenbachii (Jig. 4, No. 3) is named after the celebrated 
 German naturalist Blumenbach ; the generic name, caly'mene (formed from 
 the Greek kekalumene, concealed) was devised to express the obscure nature 
 of this genus of trilobites. It is found expanded, with its under surface 
 attached to and blended with the limestone, or coiled up. The head is large, 
 convex, rounded in front, with a broad border, and divided into three lobes 
 by two longitudinal depressions. It has two compound eyes with numerous 
 facets, situated at the back of the head remote from each other. This spe- 
 cies is from one to four inches in length. MantelL 
 
 " It is a curious fact," says Mr. T. A. Conrad (Palaeontologist, State of 
 New York, 1838), " that, whilst the Caly'mene Blumenbachii ceased to 
 exist in New York after the final deposition of the Trenton series, it escaped 
 into remote seas and lived in the era of the Dudley limestone." 
 
 In another genus, A'saphus (from the Greek asaphes, obscure), the cara- 
 pace is wide and much depressed (Jig. 4, Nos. 1,2); the middle lobe distinct, 
 the cephalic portion rounded in front, and terminating posteriorly in a sharp 
 process on each side. The eyes are compound, and each contains four hun- 
 dred spherical lenses. Some kinds of A'saphus have remarkably long, 
 pointed, caudal appendages, or tails, (fig. 4, No. 1). Some American species 
 of this group are eighteen inches in length. Mantell. 
 
 31. Besides the trilobites, the remains of other animals are found 
 in the Cambrian and Silurian Systems. They mostly belong to 
 the division of brachiopod mollusks. Among those which are 
 regarded as characteristic of the Silurian System are the Orthis 
 orbicularis (fig. 5), Orthis testudinaria (Jig. 6) : the orthis is a 
 circular shell with a striated surface, and long, narrow hinge; 
 
 Fig. 5. Orthis orbicularis. Fig. 6. Orthis testudinaria. 
 
 the Orthoceras (Jig. 7), (from the Greek orthos, straight, and keras, 
 horn) ; the Lithuites (Jig. 8), of large dimensions ; the Productus 
 
 Fig. 7. Orthoceras conica. 
 
 Fig. 8. Lithuites giganteus. 
 
 31. Name some of the fossils found in the Cambrian and Silurian Sys. 
 terns. To what division of the animal kingdom do these fossils belong ? 
 
80 
 
 PRODUCTUS. SPIRIFER. TEREBRATULA. 
 
 (Jigs. 9, 10), (Latin, drawn out, dikted) ; or Leptena (from the 
 Greek leptos, slender). 
 
 Fig. 9. Productus depressus. 
 
 Fig. 10. Productus antiquatus. 
 
 " The genus Productus has received its name from a peculiarity observed 
 in several species where the dorsal valve, after having attained a certain 
 magnitude, bends suddenly at right-angles to its former direction, and is 
 then continued irregularly, sometimes being produced (extended) to a con- 
 siderable length. The whole shell is usually covered with striae and spines, 
 which in some species are numerous and very long, and which appear to 
 have been movable, doubtless serving a purpose in the animal economy." 
 Ansted. 
 
 32. The Spi'rifer (Jig. 11), (from the Latin spira, a wreath or 
 
 twisting, and fero, I bear), is a bra- 
 chiopod, closely resembling the tere- 
 . bratula in many important characters, 
 / but differing from it in the singular 
 ' spire of calcareous matter passing 
 across the interior of the shell, and 
 from which the name of the genus 
 is derived. The species are very 
 Fig.U.-Spirifer tngonahs. numerous? an d, next to terebratula, 
 
 are 'the most abundant of all brachiopod fossils. 
 
 33. The genus Terebru'tula (Jigs. 12, 13, 14), (from the Latin 
 
 terebro, I bore ; bored, alluding to the perforated 
 beak). Throughout the whole of the palsc'ozoic 
 
 Fig. 12. Terebra- 
 tula digona. 
 
 Fig. 13. Terebra- 
 tula octoplicata. 
 
 Fig. 14. Terebratula 
 navicula. 
 
 formation, certain species of terebra'tulse are found. This remark- 
 able genus, which has in the present day some representatives in 
 the existing seas, appears to have been created among the very first 
 of the inhabitants of the first formed ocean, and to have retained 
 
 32. What is the peculiarity of the Spi'rifer ? 
 
 33. What are terebratula} ? 
 
PENTAMERUS POLYPARIA. 
 
 its place longer than any other. From the incalculable antiquity 
 of their lineage, the terebratulae have been humorously styled the 
 Fossil aristocracy. 
 
 34. The genus Pentame'rus (Jigs. 15, 16, 17 from the Greek 
 pente, five, and meros, parts, or cells), contains four known species, 
 all of which belong to the Silurian rocks. In 
 this genus, the lesser valve is divided inter- 
 nally by two parallel walls, or septa, running 
 close together lengthwise along the shell, 
 forming three cells ; the other valve also has 
 a septum or wall, which is forked towards the 
 beak of the shell, and divides it into two cells ; 
 thus forming the five cells to which it is in- 
 debted for its generic name. The casts of 
 these shells (fig- 15), often have fissures, pro- 
 duced by the decomposition of the septa ; and occasionally these 
 cavities are occupied by calcareous spar. 
 
 Fig. 15. Cast of the 
 Pentamerus lavis. 
 
 Fig. 16. Pentame'rus Knightii. Fig. 17. Section of same Shell. 
 
 35. Of the polypa'ria or corals which existed when the Silurian 
 
 Fig. 18Cyathophyllum turbinatum. Fig. 19. Catenipora escharoides. 
 
 rocks were formed, representations of two genera are given. The 
 
 34. How is the genus pentame'rus characterized ? 
 
 35. Did corals exist in the Cambrian and Silurian rocks ? 
 
32 ORGANIC REMAINSDEVONIAN SYSTEM. 
 
 Cyatho'phyllum (Jig. 18), (from the Greek, kuathos, a cup, and 
 phullon, a flower). The abundance of corals of this genus in the 
 Silurian system proves that the seas of that epoch must have 
 teemed with these zo'ophytes. The Cate'nipora (Jig> 19), (from 
 
 the Latin, catena, a 
 chain, and porus, a 
 pore). The oval form 
 of the cells when united 
 laterally, and the flexu- 
 ous disposition of the 
 lamellae, give rise .in 
 transverse sections to 
 elegant catenated mark- 
 ings, from which ap- 
 pearance the fossil has 
 received the name of 
 chain-coral. The spe- 
 cies figured (Jig. 19), 
 is common in Silurian 
 limestone, and some- 
 times forms hemispher- 
 ical masses more than a 
 foot in diameter. 
 
 36. The organic re- 
 mains of the Cambrian 
 system differ from those 
 of the Silurian system 
 in being less developed ; 
 the genera and species 
 of mollusks and corals 
 found in both are alike. 
 
 37. The DEVONIAN 
 SYSTEM (so called be- 
 cause it is largely deve- 
 
 Fig. 20.* Fossil Fishes of the Devonian System, loped in Devonshire, 
 
 England) forms the su- 
 perior part of the preceding formation. It appears to be composed 
 
 * Explanation of Fig.2Q. 1. Pterichthys cornutus, seen from above 
 (Pterichthys, from the Greek, pteron, wing, and ichthos, fish : cornutus, La- 
 tin, horned. The horned wing fish). 2. Coccosteus oblongus. These 
 figures are restored with great accuracy from the best preserved specimens 
 hitherto discovered. The British species of fossil wing-fishes, of which 
 five or six are known, are all very small, varying in length from one to 
 eight or ten inches. But in the Devonian strata of Russia enormous spe- 
 cies occur ; the spines of some of them exceed a foot in length. See Man- 
 tell 1 s Medals of Creation. London, 1844. 
 
 36. How do the fossils found in the Cambrian rocks differ from those of 
 the Silurian System ? 
 
DEVONIAN SYSTEM. 
 
 33 
 
 at first of pudding-stone, with which it commences, and to pass to 
 sandstone, with which it alternates at different places. Then come 
 
 Fig. 21. Caryopliy'llia fastigia'ta. 
 
 Fig. 23. Calceola sandalina. 
 
 Fig. 22,Amplexus coralloi'des 
 
 sandstone-schists, more or less fine, different species of schist, lime- 
 stones, alternating with each other, in the midst of which are found 
 beds of anthracite. These va- 
 rious materials are differently 
 developed in different coun- 
 tries : in England the sand- 
 stones predominate. They 
 form the old red sandstone, 
 comprising strata of clay and 
 marl of different colours. In 
 other places the limestones 
 prevail with different clay- 
 slates, or chloritic schists, some- 
 times intercalated with schistose Fi S' M'Clyme'ma linea'ris. 
 quartz, as in Devonshire, and sometimes almost alone, as in Corn- 
 wall. 
 
 37. What is the origin of the term Devonian System ? What is its 
 geological position ? Of what rocks does it consist ? 
 
34 
 
 SLATE SYSTEMS OF ROCKS. 
 
 38. This system presents us with depots of the oldest com- 
 bustible materials known ; and we find in it ferns, ca'lamites, divers 
 species of plants, differing but little from the plants found in the 
 
 coal formation which 
 
 immediately follows. 
 We here find also a 
 great many pol'yps 
 more or less analogous 
 to the Caryophyllia 
 (fig. 21) ; Jimplexus 
 (fig. 22), by some re- 
 garded as polyps and 
 by others as chamber- 
 ed shells, which are 
 found nowhere beside. 
 
 Fig. 25. Megalodon cuculla'lus. - ~, ,. * 
 
 so nearly resembling 
 
 certain productus, appears to be characteristic of the Devonian 
 rocks ; and perhaps also the Clymenia Hnearis (Jig. 24), a cham- 
 bered shell with aventral siphon. Certain peculiar bivalves are 
 also found (Jig. 25); some brachiopods, and among others the 
 Terr ebra' tula porrecta (Jig. 26). 
 
 39. Slates, so" extensively used for roofs, are furnished from this 
 
 group of ancient rocks ; 
 and on many we find im- 
 pressions of trilobites. The 
 upper part of the transition 
 strata often contains car- 
 boniferous materials, some- 
 times disseminated among 
 the schists, and at others 
 constituting more or less ex- 
 tensive masses, w r hich are 
 
 generally composed of anthracite, though sometimes of bituminous 
 
 coal. 
 
 40. These three systems of rocks, namely the Cambrian, Silu- 
 rian and Devonian, which are not easily distinguished from each 
 other, are found in most countries of Europe, where their 
 assemblage constitutes the greater part of what is named the 
 transition or palaeozoic formation. They abound in Brittany : 
 there the anthraciti'ferous mass forms a stripe along the Loire, ex- 
 tending from Maine to Morbihan, as well as other depots in Sarthe 
 and Mayenne. These rocks are found through the whole chain 
 
 Fig. 26. Terrebra'tula porrecta. 
 
 38. What fossils are found in the Devonian System ? 
 
 39. What useful material is found in the Devonian System ? 
 
 40. What systems of rocks constitute the palaeozoic formation ? 
 is this formation met with ? 
 
 Where 
 
POSITIONS OF THE DIFFERENT STRATA. 35 
 
 of the Pyrenees, in the southern part of Cevennes, in the moun- 
 tains of Forez and Beaujolais, and in some parts of Vosges. They 
 form all the Hundsruck, Eiffel, and Ardennes and the southern 
 part of Belgium. They are met with in Hartz, in Saxony, and 
 different parts of Germany, Sweden, and Norway ; and they 
 abound in England as well as in the United States. They every- 
 where offer a matrix for anthracite. 
 
 41. Geologists are not agreed as to the natural limit between 
 these strata and those of a more recent order, generally designated 
 under the name of secondary formation ; but most authors con- 
 sider the period of transition to cease beneath the carboniferous 
 rocks and the coal measures. 
 
 42. While the different stratified rocks we have spoken of were 
 in progress of formation, there were effusions of granite and other 
 igneous rocks on their surface, and these geological convulsions 
 have produced in the strata elevations and changes of direction, so 
 that many of them are raised up and are very much inclined and 
 in some instances almost vertical. It was during one of these 
 revolutions that the mountains of Westmoreland and Cornwall, in 
 England, were suddenly elevated ; a part of those of Brittany, and 
 Bigorre, &c., in France, of the Hundsruck, Eiffel, and Hartz, in 
 Germany, and many other mountain chains. The superior transi- 
 tion strata, which were formed subsequently to this convulsion and 
 rested on the edge of strata thus upheaved, were in turn dislocated 
 and raised up, and according to the observations of a French geo- 
 logist, Elie de Beaumont, this elevation appears to have been ante- 
 rior to the formation of more recent rocks than those we have yet 
 mentioned, and to correspond with the eruption of masses of igne- 
 ous rocks of the mountains of Vosges, known under the name of 
 buttons of Alsace and Comte. The elevation of the hills of Bocage, 
 in Calvados and several mountain chains in England, Germany 
 and Poland appears to have occurred about the same time. 
 
 The following diagram (fig. 27), represents the several strata 
 we have described, in a horizontal position, one lying above the 
 other, and embraces the granite or plutonic rocks below, next the 
 aqueous or metamorphic rocks, and above the whole, the transition 
 formation, consisting of the Cambrian, Silurian and Devonian Sys- 
 tems of strata. 
 
 
 {Devonian Sys'em Fossils- 
 
 -Fishes. 
 
 
 Silurian System Fossils ' 
 
 Frilohi'es 
 
 rv_ 07 
 
 
 -Polyps. 
 
 Tig* <*/ 
 
 {Arzillaceous-chist. 
 
 
 
 Mica-schist. 
 
 
 
 Gneiss. 
 
 
 
 Granite Pluionic Rocks. 
 
 
 
 A B 
 
 
 41. How is the transition separated from the secondary formation? 
 
 42. What is supposed to have happened while the stratified rocks were 
 being formed ? 
 
36 THIRD GEOLOGICAL EPOCH. 
 
 If we suppose the strata to have been in this position at the time 
 of a geological convulsion, such as we have alluded to above, and 
 that the granite should force its way upwards at A or B, we should 
 find perhaps all the relations of the strata changed, presenting 
 something like the arrangement represented in the following figure. 
 
 Transition. Stratified. 
 
 Fig. 28. 
 
 The above figure represents the effect of the sudden rising up 
 of a mass of granite, bursting and breaking through all the strata 
 that were lying above it. Instead of a horizontal level surface, as 
 in fig. 27, we have a mountain of granite, from the lowest stratum, 
 overtopping all the more recent formations ; and the ends of the 
 several strata, where they were broken to give passage to the 
 granite, are brought up towards the earth's surface, represented by 
 the dotted line. In such a case as we here suppose, it would be 
 very difficult for one who had not studied the subject to determine 
 which stratum was first formed : it might seem to him that inas- 
 much as he finds the granite occupying the highest point, and the 
 transition rocks the lowest, that the granite is of the last or most 
 modern formation. 
 
 LESSON III. 
 
 THIRD GEOLOGICAL EPOCH. Secondary Formation Carbonife- 
 rous Formation Old Red Stone fossils Coal Formation 
 Fossils Extent of Coal Measures. 
 
 FOURTH GEOLOGICAL EPOCH. New Red Sandstone Fossils 
 Triassic System Bunter Sandstein Mushelkalk Keu'per 
 Ammonites Fossils. 
 
 FIFTH GEOLOGICAL EpocH.~-Zz's, or Lia'ssic System Fossils 
 I'chthyosau'rus Plei'siosau'rus Pteroda' ctylus O'olitic 
 System Fossils. 
 
 THIRD GEOLOGICAL EPOCH. 
 Secondary Formation Carboniferous Formation. 
 
 1. After the great revolutions which seem to have terminated 
 the ancient period commonly designated as the transition epoch, 
 
OLD RED SANDSTONE, &c. 87 
 
 the earth appears to have remained in a state of repose for a long 
 time, which permitted new generations of organized beings to mul- 
 tiply on its surface, and mineral substances, carried by the waters, 
 to be deposited in great layers, and to entomb in their substance 
 the solid remains of the exuviae of contemporaneous animals and 
 plants. 
 
 2. The first deposits which took place during this geological 
 epoch, constituted the strata of sandstone, conglomerate, (an assem- 
 blage of fragments of rocks and pebbles, cemented together by 
 other mineral matter,) clay, calcareous rocks, &c., and from their 
 union resulted the formation called by geologists the old red sand- 
 stone, on account of its antiquity and prevailing colour. But this 
 state of things was soon changed, and there was formed, slowly 
 and gradually, at the bottom of the waters, an immense stratum of 
 calcareous rocks, seven or eight hundred feet in thickness ; then 
 the sandy sediment alternated with these limestones, and above this 
 great formation, designated under the name of carboniferous (coal- 
 bearing) limestone, numerous strata of sandstone, schistose cky 
 and coal were accumulated. 
 
 3. The fossils of the old red stone are somewhat numerous, and 
 belong, for the most part, to marine animals, among which was a 
 fish of strange form, called cephalaspis, (from the Greek, kephale, 
 head, and aspis, shield or buckler,) because its head resembles a 
 kind of buckler (Jig. 29). 
 
 Fig. 29. Cephalaspis Lyellii. 
 
 The remains of the genus Cephalaspis (fig. 29) are found chiefly in the 
 upper beds of the old red sandstone of Scotland, but also in Herefordshire 
 and Wales. " In this genus, the head is very large in proportion to the 
 body, and occupies nearly one-third of the entire length of the animal ; its 
 outline is rounded and crescent-shaped, and the lateral horns slightly incline 
 towards each other, their points being nearer to one another than they are 
 to the round part of the snout. The middle of the head is elevated, and 
 the sides dilated, so as to overlap the body, and extend considerably behind 
 it; but perhaps the head only appears to extend so far, owing to accidents 
 of displacement since the death of the animal. The eyes are placed in the 
 middle of the shield, near to each other, and are directed straight upwards. 
 It is imagined that the pointed horns of the crescent may have been useful 
 
 1. What happened after the termination of the transition period of geo- 
 logical history ? 
 
 2. What were the first deposits after the transition period ? 
 
 3. What is the character of the fossils of the old red sandstone ? What 
 is the Cephalaspis ? 
 
 4 
 
CARBONIFEROUS LIMESTONE. 
 
 as defences when the fish was attacked by the powerful cephalopoda which 
 inhabited the ocean at the period of its existence." The head and body are 
 covered with scales, of peculiar and varied shapes. Ansted. 
 
 4. The carboniferous limestone, also called mountain limestone, 
 and metalliferous limestone, affords several varieties of black, 
 bluish grey, and variegated marbles, as well as ores of lead, cop- 
 per, zinc, &c. It contains a great number of organic remains, 
 such as divers polyparia cyathophylla (Jig. 18), madrepora, &c., 
 encrinites, which belong to the division of crinoidea (fig. 30). 
 
 It also contains the remains of a number of mollusks, as the 
 orthoceras lateralis (fig. 31) ; goniatites (fig. 32), which resem- 
 ble the nautilus ; bellerophons (fig. 33), which, with analogous 
 forms, are not chambered ; euomphalus (fig. 34) ; spirifers and 
 productus in great variety, especially (figs. 35, 36). 
 
 The Crinoidece, (from the Greek, krinon, a lily, and eidos, resemblance,) 
 a family belonging to the class of radiate animals, are remarkable for the 
 simplicity of their organization, and the peculiarly com. 
 plicated structure of their skeleton. The animal resem- 
 bled a true polyp or coral animalcule ; the body consisted 
 of a gelatinous tube, contracted at one extremity, by 
 which it was attached, and furnished at the opposite end 
 with a variable number of delicate contractile filaments 
 placed around the opening which represents the mouth. 
 
 The calcareous skeleton was formed within the tube, 
 and consisted of thousands of regularly-shaped pieces, 
 kept together by the tough membrane which enclosed 
 them during the life of the animal. 
 
 The family is divided into genera, according to the 
 form of the stems, or according to its general shape. 
 When the arms or stems are round, it is an Encrinite ; 
 Fig- 30 ^-Cyatho- t ' ie cyathocrinites (Jig. 30) takes its name from the 
 criniles planus. Greek i kuathos, a cup, and krinon, lily. 
 
 Many limestones are composed almost exclusively of 
 
 the remains of species of Crinoidea, as at Lockport, New York ; and various 
 genera of this family are found in Alabama, near Huntsville. 
 
 The Orthoceras^ or orthoccratite, (from the Greek, orthos, 
 straight, and keras, horn,) is straight, or slightly bent, cylin- 
 drical, slightly conical, many-chambered cell ; the chambers 
 are separated by plain septa, which are concave towards the 
 larger end, and pierced with a siphuncle. 
 
 Go'nialites (Jig. 32), (from the Greek, 
 gdnia, an angle,) is a genus of extinct 
 cephalopods, which inhabited a cham- 
 bered shell resembling that of the am- 
 monites. 
 
 Belle'rophon (Jig. 33), (from the Greek, 
 Bellerophontes, the name of a fabulous 
 hero,) a genus of cephalopods which in- 
 
 . Ortho- habited chambered shells similar to those 
 
 ceras lateralis. of the argonaut and nautilus. 
 
 Fig. 32.Go'nia. 
 tiles cvolutus. 
 
 4. What are the characters of the carboniferous limestone ? 
 
COAL FORMATION. 
 
 The Euomphalus (fig. 34), (from the Greek, U, properly, and omphalos 
 the navel,) was a gasteropod mollusk. The shell is 
 often exceedingly thick, and is divided irregularly into 
 a number of compartments or chambers, provided with 
 a solid tube running through them, entirely shutting 
 off that part of the shell in which the animal dwelt, 
 from the smaller and uninhabited portion. These 
 empty spaces served, no doubt, as floats, rendering the 
 whole mass of the shell and animal sufficiently light 
 to move easily in the water. Ansled. 
 
 Fig. 33.Belle'ro- 
 phon coslatus. 
 
 Fig. 34. Euom'pkalus penta'ngula'tus. 
 
 Fig. 35. Spi'rifer glaber. 
 
 Fig. 36. Productus Martini. 
 
 5. At the period of the Coal Formation, the earth appears to 
 have been occupied, in a great part, by a deep sea studded with 
 islands, covered by an abundant and luxuriant vegetation. The 
 then existing plants differed very much from those now living ; 
 hundreds of different species are known, but almost the whole of 
 them belonged to the class of vascular cryptoo-a'mia : they are 
 principally ferns, equisita'ceae, lycopodia'cere, that is, plants of a 
 very simple structure but of gigantic size. The tree-ferns, of 
 which existing species do not exceed 20 or 25 feet in height, even 
 in the torrid zone, and generally not more than 8 or 10 feet, then 
 grew, in localities far beyond the tropics, from 40 to 50 feet high ; 
 and other plants, whose representatives of the present time are 
 mere herbs, then rose to 60 feet in height. 
 
 6. In that period, there were also insects resembling weevils and 
 neuro'ptera of the present day ; scorpions, which differed from the 
 
 5. What was the condition of the earth at the period of the coal formation ? 
 
40 
 
 COAL FORMATION. 
 
 existing species in the number of their eyes ; fresh-water mollusks, 
 and very remarkable fishes, which, in certain respects, resembled 
 reptiles, and had their bodies covered by thick solid plates. 
 
 7. The debris of the plants of that period, accumulated in im- 
 mense masses and altered by time and other causes, were trans- 
 formed into the combustible material, which is so immensely 
 valuable, known under the name of coal. 
 
 8. The deposits of coal begin, in France, ordinarily with pud- 
 ding-stones formed of the debris of different rocks from the sur- 
 rounding country, often comprising gigantic blocks scarcely rounded. 
 Sometimes finer pudding-stones alternate with sandstone, which 
 always constitutes a chief part of the deposit. Very numerous va- 
 rieties of these sandstones, arising from the size of the grains of 
 quartz and the quantity of argilla'ceous matter entering into their 
 composition, are found ; they are frequently micaceous and schistose ; 
 they contain beds of clay -slate and bituminous schist, which are 
 sometimes very thick, but rarely calcareous strata. The masses 
 of coal are scattered throughout, but are always separated from the 
 sandstone by beds of slate ; these are at first nearly pure, then 
 mixed with the combustible, and finally are represented alone above 
 the deposit. 
 
 9. Besides the coal formed by the accumulation of the debris of 
 
 decomposed plants, the coal-measures con- 
 tain a great number of the remains of 
 plants which retain their organic charac- 
 ters : the stems and trunks of trees are 
 found in the sandstone ; the leaves have 
 left their imprints perfectly preserved in 
 the schists and clays which accompany 
 the coal. 
 
 10. The impressions of ferns are ex- 
 tremely numerous ; among them is the 
 Pecopteris (fig* 37), of which the leaflets, 
 but little detached from the pedicle, are 
 joined in a single leaf, deeply incised, in 
 which we recognise a principal nervure, 
 from which the secondary nervures arise 
 perpendicularly ; the Sphfcnopteris (Jig. 
 38), analogous to the preceding, but in 
 which the leaflets are more distinct, deeply 
 lobed, and have the nervures radiate al- 
 most from the base ; the Neuro'pteris 
 Fig.31. -Pecopteris aquilina.^g which a ls has the leaflets de- 
 
 6. What animals existed at that period ? 
 
 7. From what was coal formed ? 
 
 8. In what kind of rock is coal found ? 
 
 9. In what do we find impressions of plants ? 
 
COAL FORMATION. 
 
 41 
 
 tached, but entire and rounded, and the nervures arise very obliquely 
 from the middle nervure, and afterwards frequently divide ; and a 
 great number of other genera founded on the form of their leaflets 
 
 Fig. 3d. Sp/tanopleris Haninghausi. Fig. 39. Neuropteris Loshii. 
 
 and the arrangement of their nervures. We also find various other 
 plants, the families of which are uncertain, such as the Spheno- 
 phyllites (fig. 40), Jlnnula'ria, &c. (fig. 41), which are very 
 abundant in certain localities. 
 
 Fig. 40. Spheno'pJiyllum 
 dentatum. 
 
 Fig. 41. Annula'ria brevifolia. 
 
 11. True equisita appear to have existed in the coal-measures ; 
 but we are also led to place in the same family certain stems, 
 grooved lengthwise, with joints at intervals from which branches 
 sometimes spring (Jigs. 42, 43). These stems, called ca'lamites, 
 
 10. Name some of the genera of fossil plants found in coal-beds. 
 
 4* 
 
42 
 
 COAL FORMATION. 
 
 are often found, like all the rest of those of which we speak, con- 
 verted into argillaceous matter, which has become hard, or into car- 
 bonates of iron, but rarely into silicious matter. The external 
 vegetable tissue is frequently found to have passed into a carbonous 
 state. 
 
 Fig, 42._ Calami'tes suckovii. Fig. 43. Calami'tes cann&fo'rmis. 
 
 12. The Lycopodia'cex embrace various species of Lepidode'n- 
 drons (figs. 44, 45), of which entire trees have been sometimes 
 found, upwards of sixty feet in height. Their trunks present 
 rhomboidal projections, spirally arranged, which clearly exhibit 
 near the top cica'trices of leaves. 
 
 Fig. U.Lepidode'ndron crena'tum. Fig. te.Lepidode'ndron e'legans. 
 
 13. The Sigilla'nse (fig. 46) seem to range themselves next to 
 the Cyca'decD ; their stems, flattened by pressure, are channelled 
 lenothwise but not articulated, and the cica'trices are arranged in a 
 longitudinal series. The stems, called stigma'ria (Jig. 47), are, 
 
 ~~11. What genera belonging to the family of equisita'cere are found in 
 coal-beds ? 
 
 12. What fossil plants of the family of lycopodia'cesB are found m coal- 
 measures ? 
 
COAL FORMATION. 
 
 43 
 
 according to Ad. Brongniart, probably only the roots of plants, the 
 body of which is traversed by a ligneous axis surrounded by soft 
 fleshy parts. 
 
 Fig. 46.Sigilla'ria pachyde'rma. 
 
 Fig. 47. Stigma'ria Jicoi'des. 
 
 14. The co'nifers, which, from the consistence of their wood, 
 seem to have participated largely in the formation of carbonaceous 
 matter in different 
 
 strata, present us, in 
 the different coal- 
 measures, especially 
 in the upper beds, 
 species approxima- 
 ting to the arauca'ria 
 in their spirally-ar- 
 ranged sessile leaves. 
 M. Ad. Brongniart 
 refers the whole of 
 them to the genus 
 Walchia of M. Stern- 
 berg, of which two 
 species, with their 
 leaves and fruit, are 
 here figured, (Jig. 
 
 15. Animal re- 
 
 Fig. 48. -a Walchia Schlatheimii. 
 b Walchia Hypnoidcs. 
 
 mains are not very 
 common in coal-mea- 
 sures ; stih 1 some are found, and even in great numbers in certain 
 
 13. What are sigillariae ? What are stigmarise ? 
 
 14. What genus of conifers is found fossilized ? 
 
44 
 
 COAL FORMATION. 
 
 localities. From the calcareous beds, subordinate to these sand- 
 stones, in the environs of Edinburgh, Dr. Hibbert has collected the 
 remains of enormous sauroid fishes, the strong and longitudinally 
 striated teeth of which, as well as the whole osseous system, remind 
 
 Fig. 49. Lower Jaw of the Holopticus Hibberti. 
 
 us of the largest sized reptiles. Fig. 49 represents, very much 
 reduced, a portion of the lower jaw of one of these voracious crea- 
 tures, and fig. 50 a tooth of the natural size of another species. 
 The limestone in which they are found also 
 contains particular concretions (fig. 51) which 
 are considered to be the excrement of these 
 animals, and, on this account, called coprolites, 
 (from the Greek, kopros, dung, and lithos, 
 stone). The family of squalae was then 
 represented by the division of cestra' dons, 
 characterized by teeth 
 adapted for grinding, 
 (yz^.52); and by that 
 of the hybodons, with 
 conoidal but not tren- 
 chant teeth, the ena- 
 mel of which is plaited 
 on both surfaces (Jig. 
 53). The true sharks, 
 
 Fig. 50. Tooth of the w i t h teet h flattened 
 Megalichthys Hibberti. and trenchar>t on tne 
 
 edges, (Jig. 54), did not then exist, and did not appear until very 
 much later in the creta'ceous formation. 
 
 16. Other fishes are found in the coal-basins of the continent 
 of Europe, either in the bituminous schists, as at Sarrebruck and 
 at Antun, or in kidney-shaped masses of carbonate of iron, as at 
 Saint-Etienne. They belong to neighboring genera of sturgeons, 
 named by M. Agassiz palxoni'scus, (Jig. 56), and am'blipterus, 
 and seem to have lived in fresh water. 
 
 15. What animal remains are found in the coal-measures ? What are 
 coprolites ? 
 
 16. Are any other fishes found in coal-beds ? 
 
 Fig. 51. Coprolilf-s. 
 
COAL FORMATION. 45 
 
 17. Marine shells are rare in coal strata, and are only found in 
 the subordinate limestone of Belgium and England ; but at the 
 same time there were some species of unio and some small ento- 
 mostracans Avhich indicate at least an afflux of fresh water to the 
 sea at the points where these particular deposits were made. 
 
 Fig. 52. Tooth of Fig. 53. Tooth of Fig. 54. Tooth of 
 
 Ceslracion. Hybodon. true Shark. 
 
 18. EXTENT or THE COAL-MEASURES. It is evident that the 
 coal formation cannot be found except above the Cambrian, Silurian 
 and Devonian strata, which were formed anteriorly to, or about the 
 time of these deposites. If it existed before that period, it must 
 be necessarily concealed by aU the strata subsequently formed, and 
 searches have been extended below them at great expense for this 
 combustible. The consequence is, that the coal formation occupies a 
 small portion of the uncovered surface of the earth. Ah 1 the depo- 
 sites known in France do not occupy more than one two-hundredth 
 part of the superficies of the territory. England and Belgium are 
 comparatively richer, for in the first the surface of the coal forma- 
 tion is equal to one-twentieth of the whole kingdom, and in the 
 second to one tAventy-fourth. Ah 1 the other States of Europe are 
 much poorer, and some, Sweden, Norway, Russia, Italy and Greece, 
 are almost entirely without this valuable formation. Bohemia is 
 the richest part of Germany in coal, although it does not produce 
 largely. The northern part of the Spanish peninsula seems to 
 contain considerable deposites of coal, and to participate, in this 
 respect, in the wealth of Western Europe. 
 
 19. The coal-fields of the United States are numerous and ex- 
 tensive. Coal is found in Massachusetts, Rhode Island, Pennsyl- 
 vania, Maryland, Virginia, Ohio, Kentucky, Tennessee, Illinois, 
 Alabama, Mississippi, and Indiana ; in a word, the coal formation 
 in the United States is greater than in any country or kingdom on 
 the face of the earth, and embraces every variety hitherto disco- 
 vered. 
 
 20. The different layers, constituting the coal-measures, were 
 deposited horizontally at the bottom of the basins they occupy, but 
 they have not remained in this position ; at certain places they 
 
 17. What does the existence of the genus unio in the coal-beds indicate? 
 
 18. What is the relative geological position of the coal-measures? 
 
 19. In what parts of the United States do we find coal ? 
 
46 COAL FORMATION. 
 
 were raised up, and at others lowered down, so that they became 
 more or less oblique, and often seem to be, as it were, folded on 
 
 themselves ; it is also remarked that 
 frequently a certain extent of the mass 
 formed by these layers has been sepa- 
 rated from neighboring parts by a sort 
 of split or cleft, and elevated or de- 
 pressed to a different level ; conse- 
 Fig. 55. Fault. quently the beds of coal are suddenly 
 
 interrupted at these points, and are 
 
 found further on at a different height. These geological accidents 
 are designated by miners under the name of faults, (Jig. 55). 
 
 Speaking of the origin and nature of coal, Dr. Buckland remarks, " The 
 most early stage to which we can carry b<ick its origin, was among the 
 swamps and forests of the primeval earth, where it flourished in the form 
 of gigantic Ca'lamites, and stately Lepidode'ndra, and Sigilla'rice. From 
 their native bed, these plants were transported into some adjacent lake, or 
 estuary, or sea. . Here they floated on the waters, until they sank saturated 
 to the bottom, and being buried in the detritus of adjacent lands, became 
 transferred to a new estate among the members of the mineral kingdom. 
 A long interment followed, during which a course of chemical changes, and 
 new combinations of their vegetable elements, converted them to the mine- 
 ral condition of coal. By the elevating force of subterranean agency, 
 these beds of coal have been uplifted from beneath the waters, to a new 
 position in the hills and mountains, where they are accessible to the industry 
 of man. From this fourth stage, coal has been removed by the labours of 
 the mirier, assisted by the arts and sciences, that have co-operated to pro- 
 duce the steam-engine and the safety-lamp. Returned once more to the 
 light of day, and a second time committed to the waters, it has, by the aid 
 of navigation, been conveyed to the scene of its next and most considerable 
 change by fire ; a change during which it becomes subservient to the most 
 important wants and conveniences of man. In this seventh stage of its 
 long and eventful history, it seems, to the vulgar eye, to undergo annihila- 
 tion ; its elements are, indeed, released from the mineral combinations 
 which they have maintained for ages, but their apparent destruction is only 
 the commencement of new successions of change and of activity. Set free 
 from their long imprisonment, they return to their native atmosphere, from 
 which they were absorbed by the primeval vegetation of the earth. To- 
 morrow they may contribute to the substance of timber in the trees of our 
 existing forests ; and, having for a while resumed their place in the living 
 vegetable kingdom, may, ere long, be applied a second lime to the use and 
 benefit of man. And when decay or fire shall once more consign them to 
 the earth, or to the atmosphere, the same elements will enter on some fur- 
 ther department to their perpetual ministration in the economy of the ma- 
 terial world." 
 
 21. A part of this grand upturning of the coal formation has 
 not disturbed the more recent strata by which it may be covered, 
 and consequently it must have been effected at the close of the geo- 
 logical period whose history we have just studied. 
 
 20. How were the coal-measures deposited ? What is meant by a Fault ? 
 
 21. Has the disturbance of the coal strata affected the strata subsequently 
 deposited abcve them ? 
 
FOURTH GEOLOGICAL EPOCH. 47 
 
 FOURTH GEOLOGICAL EPOCH. 
 
 (Secondary Formation Continued.} 
 
 Saliferous Formation New Red Sandstone Po'ikilitic (variegated) group. 
 
 22. The rich vegetation which adorned the surface of the earth 
 during the coal period, seems to have been entirely destroyed or 
 converted into coal, by the geological convulsion which separated 
 this epoch from the succeeding period ; this convulsion was fol- 
 lowed by the formation of extensive deposits of more ancient rocks 
 and sandy matters, as well as by the effusion of different rocks of 
 igneous origin, such as porphyries. 
 
 23. These deposits, which are indicative of great movements 
 in the waters, constitute the formation designated by geologists under 
 the names of red conglomerate, new red sandstone, rothe-todte- 
 liegende,* &c. They frequently form layers six hundred feet in 
 thickness, and contain scarcely any remains of organized beings. 
 
 24. This lower new red sandstone, or penine formation of the 
 French, is very abundant in Thuringia. It contains very few 
 organic remains. Above this red sandstone we find, in some places, 
 bituminous schists, which are very remarkable, especially in Thu- 
 ringia, for the ores of copper they contain, which circumstance has 
 gained for them the name of kupfer-s chief er, that is, copper-slate. 
 They contain plants which appear to belong to the family of algae, 
 and a very small number of terrestrial plants, such as the co'nifers. 
 Higher in the series come the compact limestones, the zechstein 
 (mine-stone) of the Germans, separated into several layers by 
 marls ; then cellular and magnesian limestones, which are more or 
 Ises friable, and again, compact limestone and argilla'ceous matter. 
 Such is the assemblage of strata in Thuringia, and in different 
 parts of Germany ; but in England the whole series is replaced by 
 the magnesian limestone. 
 
 25. It was about this geological period that animals belonging 
 to the class of reptiles were created. In this formation we find 
 for the first time the remains of sau'rians, in the bituminous schist 
 and in the zechstein, and subsequently in the magnesian limestone 
 of England. These reptiles resemble the living genera of the 
 iguana and monitor. We also find fishes of the genera palxo- 
 ni'scus (Jig. 56 from the Greek, palaios, ancient, and oniskos, 
 
 * Rothe-todte-liegende German : red, dead, lier ; so named because it is 
 of a red colour, underlies the metalliferous strata, and is dead, or worthless, 
 as far as any metallic produce is concerned. 
 
 22. What became of the plants which flourished on the earth previous to 
 the time of the coal formation ? 
 
 23. What formation is next above the coal ? 
 
 24. What are the characters of the lower new red sandstone ? What is 
 kupfer-schiefer ? 
 
 25. What animals seem to belong to this fourth geological epoch ? 
 
48 
 
 PALJEONISCUS. PLATYSOMUS. 
 
 a kind of fish), and ambly'pterm, (from the Greek, amblus, obtuse, 
 and pteron, wing), similar to those of the coal-measures ; but they 
 are not found in any formation subsequent to that we are now con- 
 sidering. 
 
 The palaoni'scus is found in 
 the magnesian limestone of 
 England and the kupferzchiefer 
 of Germany. The head is of a 
 somewhat singular form, espe- 
 cially with regard to the ante- 
 rior portion of the face, which 
 forms a rounded projection 
 Fig. 5G.Pal<B<mi sous above and beforc the upper jaw? 
 
 occasioned hy the swelling out and prolongation of some of the bones of the 
 skull. The orbit of the eye is surrounded by a series of small narrow bones, 
 and the mouth is usually large, but the teeth so exceedingly small that it is 
 rarely possible to distinguish them. The jaws, however, are powerful, and 
 more especially the lower one, which is larger than the upper. Ansted. 
 
 The genus Platyso'mus 
 (.fig- 57), (from the Greek, 
 platus, flat, and soma, body,) 
 which is found in the same 
 strata, differs considerably 
 from the palaeoni'scus, as the 
 body is of a trapezoidal form, 
 is much raised, and nearly 
 as high as it is long, while 
 from the position of the 
 scales on the edge of the 
 
 back and on the belly, it ap- 
 Fig. 51.-Platyso mus. pearg to have becn fl i ten 4 
 
 r The head is large in proportion to the size of the body, the extremity of 
 the snout forms a slightly rounded projection, the mouth is small and nar- 
 row, the jaws are armed with small but very pointed teeth, the lower jaw 
 is shorter than the upper, and broader in proportion, and the operculum (or 
 bony scale covering the gills) is narrow and much elevated. The whole 
 body is covered with large scales. 
 
 One of the most remarkable peculiarities in the structure of this fish is, 
 that although the body is flat, short, and elevated, like that of the recent 
 flat-fish, the tail instead of being, as in the latter, much forked and equally 
 lobed arrangements which appear, in the present state of things, to be in- 
 dispensable retains in the Platyso'mus the hc'tcrocercal character, the upper 
 portion having the vertebral column continued into it, and being mucfi 
 longer and more powerful than the lower portion, which rather resembles a 
 small accessory fin. Ansted. 
 
 M. Agassiz classifies fishes according to the form of their scales. All 
 those fishes with angular scales regularly arranged and entirely covering 
 the skin, constitute the order of Ganoidcans (from the Greek, ganos, splen- 
 dour). The order of Placoideans (from the Greek, plax, a broad plate) con- 
 tains fishes whose skin is covered irregularly with plates of enamel, often 
 of considerable dimensions, but sometimes reduced to small points, like the 
 shagreen on the skin of the shark, and the prickly tubercles of the ray. 
 The order of Ct.enoideans (from the Greek, kteis, in the genitive ktcnos, a 
 comb) is characterized by horny or bony scales, jagged like the teeth of a 
 
TRIASSI(T SYSTEM. 49 
 
 comb on the outer edge. The perch, and many other existing genera, are 
 of this order, which contains but few fossil forms. The order of Cyclodi- 
 ans (from the Greek, kuklos, a circle) is characterized by having scales 
 which are smooth and simple at the margin, as in the herring, salmon, &c. 
 When the vertebral column is prolonged into the caudal fin, the tail is 
 he'terocercal ; when the vertebral column terminates where the tail is given 
 off, we have the homocercal tail, as in most of the recent fishes. 
 
 In this same formation we also find Spi'rifers (fig. 58), and 
 Productus (figs. 59, 00), and especially the Productus aculea'tus 
 (fig. 59), which, under the name of gry'phites aculedtm^ has 
 been regarded as characteristic of it in Germany ; and sometimes, 
 in consequence, the zechstein is called gryphitcnkalk, which, on 
 this account, has been confounded with the lias. Other mollusks, 
 as well as the remains of encri'nites, which seem to be the same as 
 those of the carboni'ferous limestone, are also found. 
 
 Fig. 58. Spi'rifer Fig. 59. Productus Fig. GO. Pro- 
 
 undula'tus. aculea'tus. ductus calvus. 
 
 26. Next in order is a layer, known as the sandstone of Vosges, 
 which lies either on the red sandstone or magnesian limestone ; 
 or, when these strata are wanting, on some other more ancient rock. 
 After the formation of the several portions of the crust of the globe 
 just mentioned, geological convulsions again occurred, and, as it 
 appears, the mountains of Vosges, the Black Forest, &c., were 
 elevated about the same time. After this movement, new deposits 
 were formed around the base of the hills, constituting the Trias 
 System of French and German geologists, so named because it is 
 composed of three kinds of rocks. 
 
 27. The TRIAS or TRIA'SSIC SYSTEM (or upper new red sand- 
 stone of the English) consists of: 
 
 1 . Bunter Sandstein, (gres bigarre of the French), a quartzose 
 sandy deposit, which usually forms the base of the system, both in 
 France and Germany. 
 
 2. Muschelkalk, (shell-chalk), a well-marked and highly fossili'- 
 ferous limestone, rarely absent in the continental series, but never 
 found in England. 
 
 3. Keuper, a singular group of sandy marls, of variegated 
 colours, frequently containing salt and gypsum, and remarkable 
 for numerous fossil vegetable remains. 
 
 28. The BUNTER SANDSTEIN, or Gres Bigarre, is a fine-grained, 
 
 26. What is the relative position of the Vosges sandstone ? 
 
 27. What is the trias, or tria'ssic system ? 
 
 5 
 
50 
 
 BUNTER SANDSTEIN. 
 
 . 61. Bird-tracks. 
 
 solid sandstone, sometimes white, but more frequently of a red, 
 blue, or greenish tint. The structure of the lower part is tolerably 
 close-grained, and sufficiently compact to form a good building 
 
 stone ; but the uppermost strata are 
 fissile and incoherent, and pass into 
 an earthy clay containing gypsum 
 (plaster of Paris). The intermedi- 
 ate portion is compact, like the 
 lower, but its structure is that of 
 a conglomerate, and is used for mak- 
 ing millstones. In many districts the 
 Bunter sandstein contains numerous 
 remains of fossil plants and marine 
 shells, but the latter are rare and con- 
 fined to particular localities. In this 
 series are found foot-prints, (fig. 61 ), 
 some of which evidently belonged to 
 birds, and others, according to the 
 opinion of certain naturalists, belonged 
 to marsupial mammals, or gigantic 
 batrachian reptiles. 
 
 29. The sandstones and marls of this part of the series are 
 spread over an extensive tract of land in western Europe, more 
 particularly in France, and in south-western and central Germany. 
 On the right bank of the Rhine, in Swabia, there are some dis- 
 tricts in which the bunter-sandstein rests immediately on the rothe- 
 todte-liegende, the lower new red sandstone (Vosges sandstone) 
 being absent, and no other representative of the magnesian lime- 
 stone taking its place. 
 
 30. The MUSCHELKALK (also called conchylian limestone, shell- 
 limestone) is a compact limestone of a grey or greenish-grey co- 
 lour, and commonly contains, in great abundance, the remains of 
 shells and fragments of radiated animals and fishes. Sometimes 
 the muschelkalk is a bituminous rock, and emits a fetid, disagreea- 
 ble odour when rubbed or struck with a hammer. 
 
 31. Among the characteristic shells are the tfmmoni'tes nodo'sus 
 (fig. 62) ; Ji'vi'mla socia'lis (fig. 63). Possido'nia minu'ta (fig. 
 64). In this stratum the Trigo'nia ( fig. 65) is first met with, and 
 species of it are found extending through various subsequently- 
 formed strata to the chalk. A great many Encri'nitcs are also 
 found, especially the species monilifo' rmis (fig- 66). 
 
 28. What is Bunter Sandstein ? What animal remains do we find in the 
 Bunter Sandstein ? 
 
 29. Where is the Bunter Sandstein met with? 
 
 30. What is Muschel-kalk ? 
 
 31. What shells are characteristic of the Muschel-kalk ? What are Am- 
 monites ? 
 
AMMONITES. 
 
 51 
 
 The Ammonites, (Jig. 62), or Co'rnua Ammonis so called from a sup- 
 posed resemblance to the horns engraven on the heads of Jupiter Ammon 
 are among the most common and well-known fossils. Local legends, 
 ascribing their origin to swarms 
 of snakes turned into stone by 
 the prayers of some patron saint, 
 are still extant in certain parts 
 of England, and perpetuated by 
 the name of snake-stones, by 
 which these fossils are provin- v 
 cially known. Several hundred 
 species have been described ; 
 they are divided into genera, 
 which are characterized by es- 
 sential modifications in the di- 
 rection of the spire, and the 
 inflections of the septa. 
 
 The shell of the ammonite is Fi QO. Ammonites nodosus. 
 
 generally thinner and more deli- 
 cate than that of the nautilus, (to which it bears considerable resemblance), 
 and in some species it resembles the flexible covering of the argonaut; pos- 
 sibly, in these species the animal, like the recent paper nautilus, may have 
 possessed a pair of arms terminating in broad membranous expansions, 
 which secreted the shell, and generally remained in contact with it; other- 
 wise it is difficult to explain how such delicate fabrics should have been 
 uninjured. 
 
 The living and extinct species of testaceous cephalopods, " are all con- 
 nected by one plan of organization ; each forming a link in the common 
 chain which unites the existing species with those that prevailed among the 
 earliest conditions of life upon our globe, and all attesting the identity of 
 the design that has effected so many similar ends, through such a variety 
 of instruments, the principle of whose construction is, in every species, fun- 
 damentally the same. 
 
 " Throughout the various living and extinct genera of these beings, the 
 use of the air-chambers and siphon of their shells, to adjust the specific 
 gravity of the animals in rising and sinking, appears to have been identical. 
 The addition of a new transverse plate within the coiled shell added a new 
 air-chamber, larger than the preceding one, to counterbalance the increase 
 of weight that attended the growth of the shell and body of these ani- 
 mals." Buckland. 
 
 The occurrence of the nautilus and its congeners among the earliest 
 traces of the animal kingdom, and their continuance throughout the im- 
 mense periods during which the family of ammonites was created, flour- 
 ished, and became extinct, and the existence of species of the same genus 
 at the present time, are facts too remarkable to have escaped notice. To 
 these facts Mrs. Howitt alludes in the following lines to the nautilus : 
 
 "Thou didst laugh at sun and breeze 
 In the new created seas; ' 
 Thou wast with the reptile broods 
 In the old sea solitudes, 
 Sailing in the new-made light, 
 With thecurled-up ammonite. 
 Thou surviv'dst the awful shock, 
 Which turn'd the ocean-bed to rock, 
 And changed its myriad living swarms. 
 To the marble's veined forms." 
 
 See Mantell's Medals of Creation. 
 
52 AVICULA. POSIDONIA TRIGONIA ENCRINITES. 
 
 The genus A'vicula (Jig. 63) belongs to the 
 division of bivalve shells, and the fossil species, 
 a great many of which are known, resemble the 
 pearl oyster (A'vicula Margaritifera). 
 
 The genus Posido'nia, (Jig. 64), (from 
 Greek, poseidon, Neptune), also belongs to 
 bivalves, and is found in the lower part of thu 
 carboni'ferous series. 
 
 the 
 the 
 
 Fig- 65. Trigo'nia vulga'ris. 
 
 The genus Trigonia,(Jig.65 from the Greek, trigonos, three-cornered), 
 belongs to the family of ostracea ; the only living species known inhabits 
 the seas of New Holland. 
 
 Fig. 66. Encri'nites monilifor'mis. 
 
 The Encri'iiites, (Jig. 66 from the Greek, kiinon, a lily), belong to the 
 family of Echi'noderms. The skeleton of this animal is said to consist 
 of not less than 26,000 separate pieces. The body of the lily-encrinite was 
 supported on a long and nearly cylindrical column, attached to a rock or 
 some hard substance at the bottom of the sea by an enlargement of its base. 
 This column was made up of a vast number of joints, through which was 
 an aperture, descending from the stomach of the animal to the base of the 
 column. 
 
 32. The KEU'PER (a German word) is the name given to 
 the uppermost division of the tria'ssic system, and is often ap- 
 plied to the upper part of the new red sandstone formation. This 
 
 32. What are the characters of the Keuper formation ? What organic 
 remains are found in the Keuper series ? 
 
KEUPER FORMATION. 
 
 53 
 
 group usually consists of a numerous series of mottled marls, of a 
 red, greenish grey, or blue colour, which pass into green marls, 
 black slaty clays, and fine-grained sandstones. Throughout the 
 series, common rock-salt and gypsum are abundant, but the 
 organic remains of animals are extremely rare. Of plants, how- 
 ever, a considerable number are preserved in some localities ; and 
 
 Fig: 67. Volt'zia hetcro'phylla. 
 
 these indicate a wide departure from the carboniferous period, and, 
 as well as the shells, seem to 
 possess more analogies with the 
 forms of life determined from the 
 fossils of the secondary period, than 
 with those common in palae'ozoic 
 rocks. Besides peculiar species 
 of ferns, the trias presents us with 
 fossil plants not previously met 
 with. In the sandstone are par- 
 ticular species of co'nifers which 
 constitute the genus Volt'zia, (fig. 
 67), and in the limestone, remains 
 of cyc'adese of the genus mantellia; 
 this last family is very abundant 
 in the Keuper, in which are found 
 the genus Nilso'nia, and the genus 
 PterophyUum,(Jig. 68). Several 
 species of large saurian reptiles 
 are also found in the trias group 
 of rocks. Fig.bS.PCe'rophyllumPkininge'rii. 
 
 5* 
 
54 LIAS, OR LIASSIC SYSTEM. 
 
 FIFTH GEOLOGICAL EPOCH. 
 
 Lias, or Lia'ssic System Jura'ssic Formation O'olilic System. 
 (Secondary Formation Continued.) 
 
 33. Up to this period of its geological history, we have seen the 
 earth was inhabited only by plants, some inferior animals, such as 
 zo'ophytes, mollusks and fishes, and lastly, by some reptiles. Dur- 
 ing the period at which we have now arrived, this state of things 
 changed, and there Avas created a new fauna composed of most 
 remarkable animals, characterized especially by a multitude of 
 reptiles, of strange form and gigantic size. 
 
 34. The formation of the LIAS so called from a barbarous pro- 
 vincial word, supposed to be a corruption of layers, and to allude 
 to the riband-like appearance of the rock when seen in section 
 the Lias consists of strata, in which an argilla'ceous character pre- 
 dominates throughout, but which are also remarkable for a quan- 
 tity of calcareous matter mingled with the clay, and forming 
 occasional bands of argilla'ceous limestone. A few beds of sand- 
 stone also alternate with the clay and marl, and are sometimes 
 mixed with the latter, forming a marly sandstone of a white or 
 greenish colour. 
 
 35. The inferior layers of the lia'ssic system are characterized, 
 according to M. Leymerie, by the presence of the Pecten lugdu- 
 ne'nsis (Jig- 69), and different species of echi'nidae of the division 
 diade'ma (fig. 70). 
 
 Fig. 69. Pe'cten lugdune'nsis. Fig. 70. Diade'ma seria'le. 
 
 36. The middle layers, or the lias proper, are distinguished 
 especially by the presence of the Gry'phea arcudta, (fig. 71), and 
 the ammonite named after Dr. Buckland, (fig. 72), the spi'rifer of 
 
 33. What is remarked of the animals in the early geological periods ? 
 
 34. Of what is the Lias formation constituted ? 
 
 35. What animal remains characterize the inferior beds of the Lias ? 
 3G. How is the Lias proper characterized ? 
 
FOSSILS OF LIASSIC SYSTEM. 
 
 55 
 
 Walcot, (Jig. 73), the last of the race, the giant plagio'stoma, (Jig. 
 75), and the spinous plica tula, (Jig. 74). 
 
 Fig. 71. Gry'phea arena ta. 
 
 Fig. 72. Ammonites Buckla'ndii. 
 
 Fig.13. Spi'rifer Walcoti. 
 
 Fig.lt. Plica' tula Spino'sa. 
 
 Fig. 75. Plagio'stoma giga'nteum. 
 
 37. The superior part of the lias contains a great number of 
 belemnites, (Jigs. 76, 77), the ammonite named after Walcot, (fig. 
 78), and an a'vicula with unequal valves, (Jig. 79), &c. 
 
 
 Fig. 76. Bele'mnites pistillifo'rmis. 
 
 Fig. 77. Bele'mnites Sulca'tus. 
 
 37. What fossils belong to the upper part of the Lias ? 
 
56 
 
 FOSSILS OF LIASSIC SYSTEM. 
 
 . A'vicula in- 
 tBquiva'lvis. 
 
 Fig. 78. Ammonites Walcoti. 
 
 38. We also find in this group various species of Trigo'nia, 
 (fig. 80), which appear to have existed in all parts of the depo- 
 sit ; but the species, which perhaps furnish very important charac- 
 teristics, have not yet been studied sufficiently in relation to the 
 grouping. They extend through the o'olitic series to the chalk 
 formation. 
 
 Fig. SQ. 7rigo'Tiia clavella'ta. 
 
 39. We find too, in the lias for the first time, in ascending 
 through the crust of the earth, those singular saurians whose ske- 
 leton at the same time reminds us of lizards, crocodiles, fishes and 
 mammals ; their feet, which are in form of paddles, show they 
 were aquatic in their habits : such are the Ich'thyosau'rus, (fig> 
 81), some of which were twenty-five feet in length; the Plei'sio- 
 sau'rus, (fig. 82), some species of which are nearly fifteen feet 
 long. 
 
 38. Are any species of Trigo'nia characteristic of any part of the Lias ? 
 
 39. What is an Ich'thyosau'rus ? What is the lowest stratum in which it 
 is found ? What is the Plei'siosau'rus ? 
 
FOSSILS OF LIASSIC SYSTEM. 57 
 
 The I'CHTIIYOSAU'RUS (from the Greek ichthus, a fish, and sauros, a lizard 
 fish-lizard Jig. 81), must have resembled some huge fish, having an 
 exceedingly large head and very powerful tail. The spine consisted of 120 
 
 Fig. 81. I'chtliyosau'rus communis. 
 
 vertebrse or joints, besides those of the neck, which were united into a mass 
 of solid bone. The eye was an extremely powerful organ, " capable of 
 adapting itself," says Dr. Buckland, "to great changes of distance, and 
 great alterations in the amount of light in which it could be used ; giving 
 to its possessor the power of discerning a far-distant object, as well as one 
 near at hand, and of pursuing its prey in the darkness of night, or the dim 
 obscurity of the depths of the ocean, as well as in the day-time or on land." 
 This animal had a wrinkled skin, like the whale, without scales. 
 
 Fig. S2. Plei'siosau'rus dolichodeirus. 
 
 The PLEI'SIOSAU'RUS (from the Greek plesion, near, and sauros, a lizard or 
 reptile resembling a reptile -Jig. 82) may be described as exhibiting the 
 head of a lizard, attached to a neck whose length was three, or, in some 
 species, even more than four times that of the head. The body appended 
 to this head and neck was comparatively small and fish-like ; the extremities 
 were large paddles, and the tail like that of the crocodile. The neck con- 
 sisted of upwards of thirty vertebrae or joints, and was very long and flex- 
 ible. Ansted. 
 
 Fig. 83. Pteroda 'ctylus longiro'stris. 
 
 40. We also find, for the first time, in the lia'ssic group, the 
 pterodac'lylus (from the Greek pteron, wing, and daklulos, finger- 
 
58 JURASSIC OR OOLITIC SYSTEM. 
 
 fig. 83), a flying saurian, whose head and neck gave it the semblance 
 of a bird, and its tail was like that of a mammal, while its extremities 
 were analogous to those of a bat ; it was capable of walking and 
 flying, and, perhaps, of climbing steep rocks in pursuit of food. 
 
 41. With the remains of these singular animals are found, in the 
 lias of Lime-Regis, on the coast of Dorset, England, an immense 
 quantity of coprolites (from the Greek kopros, dung, and lithos, 
 stone), which probably belonged to them : sometimes their intes- 
 tines are found in their skeletons ; and we also find, in these, the 
 remains of fishes and other reptiles, clearly showing how the 
 aquatic species were nourished. The remains of insects are found 
 with those of the pteroda'ctyli at Solenhofen, in Franconia, also 
 showing what was the food of these animals. 
 
 42. Saurians resembling crocodiles were much less abundant in 
 this epoch, although we find, in the lias, remains which prove 
 their existence. The me'galosau'rus (from the Greek me gas, great, 
 and sauros, reptile) partook of the nature of the crocodile and 
 monitor, and must have been from fifty to sixty feet in length. 
 
 43. Ink-bags of considerable size (Jig. 84), ana- 
 logous to those of the cuttle-fish, are also found. In 
 the lias of Lime-Regis, the dorsal bones of the calmar 
 are also met, with other traces of this genus, as well 
 as of belemni'tes. The ink or se'pia, which may be 
 obtained from these fossils, is as good as that pre- 
 pared from the recent cuttle-fish, and has been used. 
 
 44. THE JURA/SSIC OR O'OLITIC SYSTEM. O'olite 
 (from the Greek don, an egg, and lithos, a stone), is a 
 granular variety of carbonate of lime, frequently called 
 roe-stone, from its resemblance to a fish-roe, or egg-bag. 
 The frequency of the occurrence of this particular 
 
 .. Ink- / i- ^ i i 
 
 bag. form of limestone in a great series of deposits, has 
 caused the name of o'olitic to be applied to the whole series. 
 
 45. The o'olitic or jura'ssic deposits (the Jura-kalk of German 
 geologists), are divided into several groups, which are distinguisha- 
 ble from each other by their relative position in the scale of eleva- 
 tion, but more particularly by the fossils found in them ; the re- 
 mains which are characteristic of the preceding groups, are not 
 met with in this. The o'olite is divided into the lower, middle, and 
 upper o'olites. 
 
 46. The lower o'olite, the first in the series of o'olitic deposits, 
 
 40. What is a Pteroda'ctylus ? Where is it found ? 
 
 41. What was, probably, the food of the Pteroda'ctylus ? 
 
 42. What was the Me'galosau'rus ? 
 
 43. What other fossil substances are found in lias ? 
 
 44. What is o'olite ? 
 
 45. How is the o'olitic system divided ? How are the divisions recognised ? 
 
 46. Of what does the lower o'olite consist? By what fossil is it charac- 
 terized ? 
 
FOSSILS OF THE OOLITE. 
 
 59 
 
 consists at first of layers of marl intermixed with sand, then layers 
 of ferru'ginous o'olites, and strata of compact limestone and clays, 
 more or less pure and fitted for the purposes of the fuller, and 
 hence named/w//ers' earth. The first of these marly deposits joins 
 with the marls of the lias, but is characterized by a new species of 
 gryphae'a (Jig. 85), which is not found in the preceding layers. 
 
 47. Above these deposits 
 are found fissile marls, lime- 
 stone, with ferru'ginous o'olite ; 
 to which succeed earthy de- 
 posits, the great o'olite, which 
 consists of a variable series of 
 coarse shelly limestone (lo- 
 cally called "rag"), alternat- 
 ing with beds of fine soft free- 
 stone, devoid of fossils, and 
 admirably adapted for building 
 purposes. Above these again 
 come marls, sands, clays, and 
 limestones, some of which are 
 full of shells. They are known 
 under the names of Bradford 
 day, Forest marble, and Corn- 
 brash. In spite of the num- 
 ber of fossils, often broken and 
 in the state of moulds, found 
 in this group, it is difficult to 
 designate those which are cer- 
 tainly characteristic of it. Fig. 85.Grypha'a cym'frium. 
 
 48. To the Gryphae'a cym'bium (Jig. 85), which is characteristic 
 of the first group of the o'olitic deposit, and forming, as it were, a 
 new geognostic horizon, we may add the O'strea acumina'ta (Jig. 86), 
 
 Fig. 87. Terelra'tula digo'na. 
 
 Fig. 86. O'strea acumina'ta. 
 
 47. What is found above the lower o'olite ? 
 
60 FOSSILS OF THE OOLITE. 
 
 which is found in the upper marls, or limestones sometimes met 
 with in their place : different species of Terebra'tula (Jigs. 88, 89), 
 
 Terebrat.globa'ta. FigSQ. Tereb. spino'sa. Fig.QQ. Ammonites Brongnia' rtii. 
 
 which seem to belong more particularly to the lower o'olite, as well 
 as a small globose species of ammonites (fig. 90). 
 
 49. In the limestones proper, different species of ammonites 
 (fig. 91) are found; various species of pleurotoma'ria (fig. 92), 
 
 Fig. 91. Ammonites stria' lulus. Fig. 92. Pleuroloma'ria cono'idea. 
 
 which seem to be characteristic, and a great number of shells of 
 divers kinds, are met with. Encrini'tes, frequently very nume- 
 rous, which are chiefly referred to the pyriform species, apiocri'- 
 nites, are sometimes found on the very spot where they lived, 
 attached to the solid materials forming the bottom of the sea of that 
 epoch, and covered by successive deposits of the earthy matter of 
 which it was constituted. 
 
 50. An important fact is connected with the marls and fissile 
 limestones which form the first of the o'olite system : the first, or 
 most ancient fossil mammals, were discovered in Stonefield slates. 
 
 48. What fossils are characteristic of the o'olite ? 
 
 49. What fossils are found in the limestone proper of the o'olite scries ? 
 
 50. What important fact is connected with the fissile limestone and marls 
 of the lower o'olite ? 
 
FOSSILS OF THE O'OLITE. 
 
 61 
 
 These small ani- 
 mals, the lower 
 jaw of one of 
 which is repre- 
 sented (fig. 93), 
 belong to the mar- 
 supials ; that is, 
 one of the most 
 imperfect orders 
 
 Of the Class. Fig.W.JawoftheDide'lph 
 
 Bones of large animals, thought 
 to belong to the order of ceta' 
 cea, are also found in the o'oli- 
 tic strata. 
 
 51. Con'ifers, which are but 
 rarely found beyond the shell- 
 limestones, are abundantly 
 met with in the o'olite series, 
 of particular genera (Jig. 94), 
 with Cyca'dete (Jig. 95) 
 ferns of different species, dif- 
 fering from all those met in 
 more ancient strata, and finally 
 a true equisetum (fig. 96). 
 
 \ Buckla'ndii (twice the natural size'). 
 
 Fig.95. Ptero 'pJiyllum Williamso'nis. 
 
 51. What fossil plants are found in the lower o'olite ? 
 6 
 
62 
 
 FOSSILS OF THE O'OLITE. 
 
 52. MIDDLE O'OLITE. This group, which is less complicated 
 than the preceding, at the lowest part consists of clay, called Oxford 
 clay, with layers of calcareous grit, and stratoid masses of lime- 
 stone. Above these are found sands, and limestones which are 
 more or less o'olitic, and often ferru'ginous. In this group we find 
 deposits of o'olitic iron, which had already appeared in the pre- 
 ceding series. It is very rich in fossils, particularly ammonites ; 
 and the Jinanchy'tes bicorda'tus (fig. 97) is very common. 
 
 Fig. 97. Ananchy'tes licorda'lus. 
 
 Ananchy'tes is a genus of the family of Echini'dese, or sea-urchins, some- 
 times vulgarly called sea-eggs. The family contains thirteen genera, which 
 are distinguished from each other by the form and size of the ambula'cra, 
 (alleys) the narrow longitudinal portions of the shell of the echinus or sea- 
 urchin, which are perforated with a number of small orifices, giving pas- 
 sage to tentacular suckers, and alternate with the broad tuberculate spine- 
 bearing portions (see Jig. 70) and also by the position of the vent, and of 
 the mouth. Figure 70, p. 54, exhibits the ambula'cra, between the tubercles 
 to which the spines are attached in living species. 
 
 53. What especially characterizes the Oxford clays is the pre- 
 sence, often in abundance, of a new species of Grypnae'a (Jig- 98), 
 
 Fig. 98. Gryplia'a dilata'ta. Fig. 99. 0' street Ma'rskii. Fig. 101, Tcrebra'tula impre'ssa. 
 
 the O'strea Ma'rshii (fig. 99), which already commenced in the 
 preceding group, a great number of different terebra'tula, among 
 
 52. Of what does the middle o'olite consist ? What fossils belong to it? 
 
 53. How are the Oxford clays especially characterized ? 
 
FOSSILS OF THE O'OLITE. 
 
 63 
 
 which we find in the upper part of the series, the Terebra'tula 
 Thurmanni (Jig. 100), and the Terebra'tula impressa (fig. 101). 
 The moulds of these shells are frequently silicious, and we find, 
 in the upper layers, beds of silicious balls of loose texture, some- 
 times enclosing silicious moulds of shells. 
 
 54. The upper group of the middle o'olite, called coral o'olite, 
 consists almost entirely of limestone ; it is divided into different 
 thick layers, which are distinguishable from each other by their 
 structure. The first or lowest layers are ordinarily compact, grey- 
 ish or yellowish, filled with polypa'ria or corals of a sac'charoid 
 structure, or those which have passed to the silicious state : this 
 constitutes the coral rag of English geologists. Some of the 
 succeeding layers are o'olitic, frequently of large irregular grains, 
 mingled with fragments of rolled shells ; others are compact, pass- 
 ing into chalk or even marl of greater or less solidity. 
 
 55. The numerous polypa'ria contained in this group present 
 to us caryophy'llia (fig. 21), a'strea, meandri'na, madrepores of a 
 great number of species, resembling more or less those of coral 
 reefs, and a great many other genera. Among the shells, ammo- 
 nites are less common ; but above the o'olite, where all the organic 
 remains are broken, the lowest layers contain a great quantity of 
 various shells, among which are neri'nea (figs. 102, 103). The 
 
 Fig. 102. Neri'nea Goodhallii. 
 
 Interior of the shell, showing the 
 
 plic& of its colum'nella. fig. 103. Neri'nea mosa. 
 
 superior strata contain a great quantity of astarles (figs. 104, 
 105), the most characteristic of which is the astarte minima. 
 
 54. What are the characters of the upper group of the middle o'olite ? 
 
 What is coral 
 
 rag 
 
 55. What genera of corals are found in the middle o'olitc ? What fossil 
 Shells do we find in this group ? 
 
64 
 
 FOSSILS OF THE O'OLITE. 
 
 Fig. 104. Astartemi'nima. Fig. 105. Astarte elegans. 
 
 Among other shells, we may cite the Dicefras arieti'na 
 
 106) ; and among the echi'noderms, the cida'ris corona'ta 
 (fig- 
 
 Fig. 106. Mould and shell of the Dice 'r as 
 arieti'na. 
 
 Fig. 101. Cida'ris 
 corona'ta. 
 
 56. UPPER O'OLITE. This group is divided into Kimmeridge 
 clay, and Portland o'olite. Kimmeridge clay, (so named because 
 it is well exhibited at Kimmeridge Bay, and near the village of 
 the same name, in the isle of Purbeck \, is of a blue, slaty, or grey- 
 ish yellow colour. Above this is the Portland stone, which, with 
 alternations of compact, marly, sandy or o'olitic limestones, termi- 
 nates the Jura'ssic or o'olitic system. 
 
 57. The organic remains which characterize this group are of 
 the genera ostrea, and ex'ogy'ra of particular species (figs. 108, 
 109), sometimes in great abundance. Witk a few ammonites, we 
 also find mya (fig. Ill), Pholadomy'a (fig. 110}, and Terebra'tula 
 (fig. 112), which are also equally characteristic. Certain beds 
 of this formation contain Paludi'nse, or Helices, consequently indi- 
 cating that streams of fresh water emptied into the seas of that 
 period. 
 
 56. How is the upper o'olite divided? What is Kimmeridge 
 What is found above the Kimmeridge clay ? 
 
 57. What fossils are characteristic of the upper o'olite ? 
 
FOSSILS OF THE O'OLITE. 
 
 65 
 
 Fig. 108. O'strea del 
 to'idea. 
 
 Fig. HQ.Pholadomy'a 
 a'cutico'sta. 
 
 Fig. IQ9.Ex'ogy'ra 
 vir'gula. 
 
 58. The lithographic stone of Solenhofen, in Bavaria, is referred 
 to the upper strata of the Jura'ssic system ; in it are found an im- 
 mense quantity of fossils, reptiles, particularly, pterodactyls, fishes, 
 insects, plants, &c. In some parts of upper o'olite are beds of a 
 highly bituminous shale (locally known as Kimmeridge coal); 'in 
 the latest calcareous beds of the Portland group are found cyca'dex 
 
 Fig. 112. Tere.bra'tula sella. 
 
 Fig. 113. Za'mia feneo'nis. 
 
 59. The o'olitic or Jura'ssic system of rocks is met with in Eng- 
 land and on the continent of Europe, but is not represented in 
 North America, where the transition from the new red sandstone 
 to the greensand and other rocks of the creta'ceous period is abrupt. 
 No rock answering to the Lias has yet been discovered in the 
 United States. 
 
 58. To what geological group does the lithographic stone of Solenhofen 
 belong ? What is Kimmeridge coal ? 
 
 59. In what part of the world is the o'olitic system of rocks found ? Is 
 it known in the United States ? 
 
 6* 
 
SIXTH GEOLOGICAL EPOCH. 
 
 LESSON IV. 
 
 SECONDARY FORMATION Continued. 
 
 SIXTH GEOLOGICAL EPOCH. Creta'ceous Formation Lower Cre- 
 ta'ceous System Fossils Wealden Deposit Greensand 
 Gault Fossils Upper Creta'ceous System Fossils Extent 
 of Creta'ceous Formation Table of Formations. 
 
 SIXTH GEOLOGICAL EPOCH. 
 
 CRETA'CEOUS FORMATION. 
 (Secondary Formation Continued.} 
 
 1. Next in order above the Jura'ssic system we find, in discord- 
 ant stratification, immense Creta'ceous deposits in a great many lo- 
 calities ; these deposits may be divided into several others, accord- 
 ing to the discordance of stratification observed in some of their 
 divisions. The Creta'ceous formation (from the Latin, cre/a, chalk) 
 may be divided into the upper and lower chalk. 
 
 2. The LOWER, or INFERIOR CRETA'CEOUS system : Neocomian 
 of the French ; the Shanklin, or Lower Green Sand of the Eng- 
 lish. The first deposits formed above the o'olite are composed of 
 marls, then a yellowish limestone, characterized by great numbers 
 of genus Spata'ngus (Jig. 114), with a multitude of the remains 
 of shells and polypa'na of different genera. This limestone is 
 sometimes in continuous layers of considerable thickness, some- 
 
 Fig. 114.- Spata'ngus Fig. 115. Exo'gy'ra Fig. 116. Lima 
 retusus. subplica'ta. elegans. 
 
 1. What is found next above the Jurassic formation? Why is it termed 
 Creta'ceous ? How is the creta'ceous group divided ? 
 
 2. How are the first deposits above the o'olite characterized ? What is 
 lumachella ? What is found next above the yellow limestone ? 
 
CRETACEOUS FORMATION. 67 
 
 times only in masses agglutinated to each other by mud and sand ; 
 sometimes it is entirely wanting. Above it are clays which con- 
 tain, often in great quantity, ex'ogy'ra (Jig' 115), and oysters, 
 among which is distinguished the great species, named Ostrea 
 Leymerii ; the Lima elegans (Jig- 116) is also found. Among 
 these clays are met large calcareous masses, a good deal flattened, 
 filled with the same fossil sheDs, presenting tumachdla* or conchi- 
 lians, which have been confounded with the Portland group, form- 
 ed by an accumulation of the ex'ogy'ra vi'rgula (fig. 109). Next 
 we have, at least in parts of France, sands and clays, sometimes 
 variegated in colours, among which are masses of iron ore, com- 
 monly o'olitic. The remains of shells seem to give place here to 
 ferruginous masses. 
 
 3. These last deposits seem to be wanting in other localities, in 
 which we find, instead, great layers of limestone, more or less 
 compact, sometimes white, sometimes coloured, which enclose 
 hippuri'tes,spheruli'tes,and even nummuli'tes, which have been long 
 regarded as belonging to the 
 
 tertiary formation. We also 
 find here a fossil which is 
 very characteristic ; it was at 
 first compared to the diceras 
 (Jig. 106), but is now call- 
 ed Chama ammonia (fig. 
 117). This species of shell, 
 which is often very abundant, 
 is always so imbedded in the 
 mass of rock, where it is dis- 
 tinguished by the sinuosities Fi S- H7- Cha'ma ammo'nia. 
 it forms, that it is very difficult to detach it entire. Various spe- 
 cies of ammonites, gigantic hamites, several species of Crio'ceratites 
 (fig. 118 from the Greek, Krios, 
 a ram, and Keras, horn) and belem- 
 nites. The trigo'nise, which are still 
 met with and continued to the green- 
 sand, present here new species (fig. 
 119), which seem to be characteris- 
 tic. 
 
 4. In the south of France and in 
 
 the Pyrenees the chalk formation Fig. us 
 
 * Lumachella an Italian word, formed from limacea, a snail, which is 
 derived from the Latin, Umax. The word is used to designate a mass 
 formed of the remains of snails, &c. with their nacre, united by gluten 
 It is also called conchilian marble. 
 
 3. Are sands and clays everywhere found above the yellowish limestone? 
 What fossils are found in these limestones of the creta'ccous group? 
 
68 
 
 CRETACEOUS FORMATION. 
 
 (View of Hinge.} 
 
 Fig. 119. Trigo'nia a'l&for'rnis. 
 
 possesses peculiar characters, both in relation to the organic re- 
 mains contained in it, as well as its mineralogical relations. We 
 there find a great many shells, very remarkable for their form and 
 peculiar structure, which are called hippuri'tes (figs. 120, 121), 
 ^wggrT^ and spheruli'tes (fie;. 122). Many 
 
 nummuli'tes (fig. 123), of which some 
 deposits are formed exclusively, are also 
 met with. It is not determined pre- 
 cisely to what part of the lower chalk 
 these deposits should be referred, but 
 
 Fig. 1 20. Hippuri't es lio'culata. Fig. 1 2 1 .Hippuri'tes orga'nisans. 
 
 4. How is the chalk formation characterized in the south of France ? 
 "What are Hippurites ? 
 
THE WEALDEN DEPOSIT. 
 
 they seem to represent a part of 
 the neocomian (or Shanklin) for- 
 mation. In the Pyrenees the lay- 
 ers are often of a deep colour, 
 and separated by argilla'ceous 
 schists, which seems to make 
 them a part of the transition for- 
 mation ; but, on the contrary, in 
 the north part of the ba-sin of 
 the Gironde, they belong to the 
 chalk. 
 
 5. The neocomian, which was 
 not at first distinguished from 
 other parts of the chalk forma- 
 tion, is now recognized in a 
 
 Fig. 1%2,Spkcruli teg ventricosi 
 Radiuli' te.-< lurbina'ta. 
 
 Fig. 123. Nummuli'tes from the chalk. 
 
 great part of France, Switzerland, and different parts of Germany, 
 Poland, and even to the Crimea. Here and there deposits of gyp- 
 sum of greater or less extent are met with, sometimes isolated, and 
 sometimes associated with crystalline rocks. 
 
 6. The WEALDEN DEPOSIT. We frequently meet in the first 
 deposits of the chalk formation the remains of organized bodies, 
 which appear to belong to paludi'nse, clearly showing there was 
 here and there an afflux of fresh water to those seas in which 
 these remains accumulated. We also find in the same situations 
 deposits of combustibles, which have always been known under 
 the name of lignite (from the Latin, lignum, wood), probably form- 
 ed from con'ifers (as dicoty'ledons did not then exist), which 
 were doubtlessly carried by rivers : such are those in the environs 
 of Orthez, in the department of Landes ; of Bellesta and of 
 Saint-Girons, in the department of Ariege ; of Irun, in Guipuscoa 
 (Spain), &c. But all these local deposits are nothing compared to 
 those which have long been described in England, in parts of the 
 counties of Kent, Surrey, and Sussex, under the name of wealds, 
 from which is derived the term wealden formation. 
 
 5. What is the Neocomian deposit ? What is its extent ? 
 
 6. What is meant by Wealden formation ? Why is it so called ? 
 
70 THE WEALDEN DEPOSIT. 
 
 7. This formation is composed of alternate layers of limestone, 
 sand, more or less ferru'ginous, and clay, the deposits of which are 
 sometimes extremely thick. There are .entire beds of limestone 
 composed of paludi'nre, constituting what' is named Purbeck lime- 
 stone. The lamina? of argilla'ceous matter are often covered by 
 cy'clades and anodo'ntse, and we find disseminated a great number 
 of small cypris. TJiere are many species of fresh water fishes, 
 the remains of fluviatile tortoises, mingled with marine and terres- 
 trial saurians, among which is the monstrous i'guanodon, which 
 must have been thirty feet in length, to judge from the size of its 
 
 bones. In this formation are 
 found also, in the dirt of the Isle 
 of Portland, the sili'cified stems 
 of cyca'dere (fig. 124), standing 
 erect in the midst of the earth, 
 of which the deposit consists ; 
 various species of conifers, equi- 
 sita'ceoe, and ferns are also met. 
 The remains of birds of the order 
 Fig. 124. Mante'Llia nidifo'rmis. of gra'lleas (waders)also exist, but 
 
 no mammals, although we have seen them in the marls of the 
 
 o'olite (Jigs. 81, 82). 
 
 8. It is believed that the clays in the environs of Boulogne, 
 which seem to be continuous with those of England on the south- 
 ern side of the Channel, may be referred to the wealden deposit, 
 as well as those of Forges and of Savigny in the country of Bray, 
 where paludine limestones like those of Purbeck have been found. 
 It is very certain, according to the observations of M. Leymerie, 
 these deposits are connected with those in the department of Aube, 
 and form part of the superior neocomian clays : if there are indi- 
 cations of fresh water deposits, they prove the connection between 
 the wealden formations and those of this epoch. 
 
 9. According to English geologists, the wealden formation is 
 below the neocomian, and is, consequently, older and not precisely 
 contemporaneous with it. 
 
 10. Above the neocomian and wealden formations there is a 
 group of deposits generally termed Green Sand, consisting of two 
 arena'ceous beds, with a parting of clay called gaidt. The green 
 sand formation receives its name from the prevalence of small 
 green particles of si'licate of iron distributed through the sand. It 
 is found in New Jersey. In England it is divided into lower green 
 sand, gault, and upper green sand. This group consists of white 
 
 7. What is Purbeck limestone ? 
 
 8. What is the extent of the Wealden formation ? 
 
 9. Which deposit lies above, the Neocomian or Wealden ? 
 
 10. What is found next above the Wealden and Neocomian ? From what 
 does green sand obtain its name ? How is it divided ? 
 
GREEN SAND. GAULT. 
 
 71 
 
 and yellowish sands, which are frequently ferruginous, containing 
 masses of limestone, clays, and sandstones of more or less com- 
 pactness : it also comprises the quadersandstein and plxmr-kalk 
 of German geologists. 
 
 11. Gault is a stiff clay of a blue colour, and the inferior por- 
 tion of it in England abounds in iron py'rites, while the upper part 
 contains green particles of the silicate of iron. Various nodules 
 and concretions are found throughout, which are sometimes fossili'- 
 ferous, but more frequently obscure and of doubtful origin. Gault 
 is a provincial term, used originally in the middle of England to 
 designate the brick-clay, which there belongs to the creta'ceous 
 system. 
 
 12. Above the green sand formation, the calcareous part be- 
 comes more abundant ; at first it is mixed with sandstone, and then, 
 little by little, becomes isolated, and now contains only green parti- 
 cles of si'licate of iron, which, from being at first very abundant, 
 gradually disappear : this is the chloritic chalk, which is some- 
 times friable, and at others solid. The green particles having 
 totally disappeared, the limestone is found alone, sometimes in form 
 of pure chalk, of more or less solidity, and occasionally becomes 
 very compact ; here we have argilla'ceous or arena'ceous limestone, 
 and finally sands, or nearly pure sandstone. From these result the 
 chalk marlj or representatives of it. 
 
 13. Organic remains 
 
 are 
 
 in 
 
 very abundant 
 these deposits, and in 
 species and even in ge- 
 nera are very distinct 
 from those of the preced- 
 ing formations. Immedi- 
 ately above the wealden 
 is a marly bed, charac- 
 terized by the presence 
 of a species of Ex'ogy' 
 ra (Jig> 125) five or 
 six inches in diameter, 
 not known in the neo- 
 comian. According to 
 M . Leymerie, the nu'- 
 cula pectina'ta (fig> 
 126) is a characteristic 
 shell of the gault or blue 
 
 Fig. 125. Ex'ogy'ra sinua'ta. 
 marl. Belonging to the green sand 
 
 11. What is gault ? What is the origin of the name ? 
 
 12. What succeeds the green sand formation ? What is chloritic chalk ? 
 What is chalk marl ? 
 
 13. What organic remains are found in these deposits ? 
 
72 
 
 FOSSILS. 
 
 formation generally, the characteristic shells are the inoce'ramus 
 conce'ntricus (fig. 127), the plica'tula placu'nea (Jig- 128), seve- 
 ral species of ammonites, and particularly the ammonites monile 
 (Jig- 129), which is quite characteristic. 
 
 Fig. 127. Jnoce ramus con- 
 ce'ntricus. 
 
 Fig. 126. JWcw/a pcctina'ta (.skell and mould). 
 
 Fig. l"Xi.Scnplii'tes 
 
 e'qualis. 
 
 Fig. 128. Plica'tula placu'nea. 
 
 14. We find in the chalk marl the bacilli' tes (fig. 130), and 
 turrili'tes (fig. 131), different species of the first of which are 
 found in the highest part of the chalk formation. To these may 
 be added the scaphi'tes (fig- 132), some particular species of 
 
 Fig. 129. Ammonites moniU. Fig.lZQ.Baculi'tes. 
 
 ammonites (figs. 133, 134), the Ex'ogy'ra columba (fig. 135), 
 the O'strea carina'ta (fig. 136), the terebra'tula octo'plica'ta (Jig. 
 137), which continue in "the chalk. 
 
 14. What animal remains are found in the chalk marl ? 
 
FOSSILS. 
 
 73 
 
 Fig. 134. Ammonites rotkomage'nsis: 
 
 Fig. 135. Ex'ogy'ra columba. Fig. 137. Tcrcbra'tula octo'plica 1 ta. 
 
 Nu'cula (from the Latin, nux, a nut) is an inequilateral bivalve shell; the 
 hinge is narrow, and has many teeth like those of a comb : several species 
 are known. 
 
 Scaphi'ics (from the Greek, scaphe, a boat) is an eliptical, many cham- 
 bered shell, somewhat resembling the ammonites. 
 
 Ba'culiles (from the Latin, ba'culum, a stick) is a multilocular, straight, 
 or slightly bent, and slightly conical shell ; the chambers are separated by 
 septa, pierced by a marginal siphuncle. 
 
 Turrili'tes is a spiral, turriculated, multilocurlar shell; the chambers are 
 separated by winding septa, which have the si'phuncle in their disks : the 
 aperture is round. This fossil must not be confounded with the Turrite'lla, 
 which is a univalve, found both recent and fossil. 
 
 15. The Upper Chalk Formation. In this we find chalk with 
 and without flints. The layers of flint are frequently almost the 
 only indications of stratification afforded by the mass. It is fre- 
 quently soft, and susceptible of solution or suspension, as in Spa- 
 nish whiting, which contains an immense quantity of microscopic 
 shells, belonging to the group of foraminifera. In some cases it 
 is arena'ceous, and sometimes very compact. Although often 
 white, we find it in some places coloured grey, yellow, red, &c. ; 
 
 15. How is the upper chalk formation characterized ? 
 7 
 
74 
 
 UPPER CHALK FORMATIONS. 
 
 sometimes it is o'olitic in character, and becomes almost crystalline, 
 even magnesian, and in localities remote from crystalline materials 
 which might affect it. The inferior part of this formation is fre- 
 quently soiled with clays chalk marl. Above it is more pure, 
 and contains a great many nodules of flint or silex. Though this 
 character is very common, it is wanting in a great many places. At 
 its upper part the chalk formation becomes very sandy, as in the 
 neighbourhood of Maestricht. 
 
 16. Excepting the ba'culites found at Maestricht, the remains 
 of cephalopods are not found in the upper creta'ceous formation ; 
 but belemni'tes (from the Greek, belem'non, a dart) of particular 
 species, such as Jig. 138, and many other organic remains not 
 
 Fig. 138. Belemni'tes mucrona'tus. 
 
 met with in the chalk marl, are found : among them are the pla- 
 gio'stoma spino'sum (fig. 139) ; the o'strea vesicitla'ris (fig. 140) ; 
 
 Fig. 139. Plagio'stoma spino'sum. Fig. 140. O'strea vesicula'ris. 
 
 the Ca'tylus Cuvieri (fig. 141), the structure of which is fibrous ; 
 the Terebra'tula Defra'ncii (fig. 142) ; the ana'nchytes ova'tus 
 (Jig. 143) ; the Spa'tangus cor-ari guinum (fig. 144). 
 
 Fig. 141. Ca'tylus Cuvieri. 
 
 Fig. 142. Terebra'tula 
 Defra'ncii. 
 
 16. What organic remains are found in the chalk formation ? 
 
UPPER CHALK FORMATIONS. 
 
 75 
 
 . 143. Ana'nchytes ova'tus. 
 
 Fig. 144. Spa'tangus cor.an guinum. 
 
 17. In the upper part of these deposits we find, among many 
 other fossils, an enormous saurian, called the Mosasaurus (from the 
 name of the river Meuse, and the Greek, sauros, lizard), originally 
 found on the banks of the Meuse, in the celebrated quarries of St. 
 Peter's Mount, near Maastricht (Jig. 145). Organic remains of a 
 Mosasaurus have been found in New Jersey. 
 
 Fig. 145. Head of the Mosasaurus of Maastricht. 
 
 " The Mosasaurus is a genus determined from a fossil discovered upwards 
 of sixty years ago, and which at that time was extremely puzzling to natu- 
 ralists. Its true place in the animal kingdom is now known to be among 
 the Lacertian Saurians; but the animal appears to have been perfectly ma- 
 rine in its habits. The head, the only part at first discovered, measured 
 
 7. Where is the Mosasaurus found ? From what is its name derived ? 
 
76 
 
 CRETACEOUS GROUP. 
 
 four feet in length, and is preserved in the museum at Paris. Other paits 
 have also been found from time to time in the Maastricht quarries, and some 
 fragments in the chalk of the south of England." Ansted. 
 
 The whole length of the animal was probably not less than twenty-four 
 feet, a magnitude which must be compared with that of the lizards of the 
 present day, and not with the crocodilians, whose structure is totally dif- 
 ferent. 
 
 18. We also find in the chalk formation ceta'ceous mammals, 
 which are classed among the lamantins and dolphins. 
 
 19. The CRETA'CEOUS GROUP prevails extensively in England 
 and on the continent of Europe. True white chalk exists not 
 only in England, but also in France, in Denmark, in Poland, in 
 central Russia, and in the Caucasus. Semicrystalline rocks of the 
 creta'ceous epoch also exist in the central plains of Asia Minor. 
 Beds of the creta'ceous period are found in New Jersey, and other 
 parts of the United States ; but they rest on the oldest secondary- 
 rocks, without the intervention of the o'olite. The formation is 
 extremely calcareous, in places chiefly arenaceous, but no true 
 chalk has yet been discovered in America ; nor has o'olite been 
 found. Fossils, apparently creta'ceous, have been recently obtained 
 from south-eastern India. 
 
 '" This brings us up to the close of the secondary formation. As 
 far as we have studied our subject, we find the earth's crust to con- 
 sist of a series of formations, as represented in the following dia- 
 gram (fig. 146). 
 
 Secondary . 
 
 Chalk with flints. 
 Chalk without flii 
 
 Chalk marl. 
 Green sands. 
 
 Wealden. 
 O'olitic System. 
 
 Cretaceous Systt 
 
 Liassic System. 
 
 Upper new red sandstone, orTriassic System. 
 
 Lower new red sandstone, or Permian System. 
 Carboniferous System. 
 
 Old red sandstone. 
 
 Transition. 
 
 Metamorphic. 
 Plutonic Rocks. 
 
 f Devonian System. 
 Silurian System. 
 
 ambrian System. 
 Argillaceous Schist. 
 Mica Schist. 
 
 Granite. 
 
 Fig. 146. 
 
 18. What mammals are found in the chalk formation ? 
 
 19. What is the extent of the creta'ceous group ? Has chalk been found 
 in the creta'ceous formation of the United States ? 
 
SEVENTH GEOLOGICAL EPOCH. 77 
 
 The study of the creta'ceous rocks brings us, as it were, to the 
 termination of that period in the history of the earth's structure to 
 which the character of antiquity belongs. In the succeeding 
 period, we shall find all the fossils are either resemblances or types 
 of existing organic creatures. 
 
 LESSON V. 
 
 SEVENTH GEOLOGICAL EPOCH. Tertiary Formation Eocene 
 beds Paris Basin Fossils Jlnoploihe'rium Paleothe'rium 
 Miocene beds Dinothe'rium Lignites Pliocene beds- 
 Fossils Bone Caverns. 
 
 SUPERFICIAL DEPOSITS. Drift Diluvium Megathe'rium 
 Boulder Formation Alluvium Big Bone Lick. 
 
 EIGHTH GEOLOGICAL EPOCH. Modern Formation. 
 
 SEVENTH GEOLOGICAL EPOCH. 
 TERTIARY FORMATION. 
 
 1. Ordinarily, geologists designate under the collective name of 
 SECONDARY FORMATION, the long series of systems of rocks, com- 
 mencing above the transition formation with old red sandstone and 
 coal (fig. 146), and terminating above with the chalk ; and they 
 give the name of TERTIARY FORMATION to those strata which are 
 more recent than the chalk, and consequently superior to it, but 
 still more ancient than the strata of the present or modern epoch. 
 
 2. During that period the seas were very much less extensive 
 than they were in the more remote geological ages, and conse- 
 quently the sedimentary deposits formed in those waters are of less 
 extent and more isolated. Moreover, their formation was effected 
 at different points of the globe, and at different periods, and to fol- 
 low their history in chronological order, it is necessary to subdivide 
 them into three groups. At the period contemporaneous with the 
 deposit of each one of these series of formations, there existed 
 particular species of organized creatures, mingled with other spe- 
 cies like the preceding or succeeding periods ; but the fauna of all 
 the divisions of this period possesses certain common characters, 
 and among the most remarkable of these is the existence of a 
 great number of mammals. 
 
 i 1. What is understood by secondary formation ? What is meant by ter- 
 tiary formation? 
 
 2. How did the seas of the tertiary epoch differ from those of more re- 
 mote geological ages ? What is the most remarkable characteristic of the 
 tertiary formation ? 
 
 7* 
 
78 TERTIARY FORMATION. 
 
 3. The Tertiary Formation is divided into the older, middle, and 
 newer tertiary groups, which have been conveniently designated 
 by Mr. Lyell under the names of Eocene, Miocene, and Pliocene. 
 
 The first, EOCENE (from the Greek, eos, dawn, and kainos, 
 recent), designates the older tertiary strata, in which there appears, 
 as it were, the first dawn of existing species. 
 
 The second, MIOCENE (from the Greek, melon, less, and kainos, 
 recent), is applied to the middle tertiary strata, because in them we 
 find more recent species than in the preceding group, but still 
 fewer recent than extinct species. 
 
 The third, PLIOCENE (from the Greek, pleibn, more, and kainos, 
 recent), is given to the newer tertiary beds, because there is always 
 a greater number of recent than of extinct species found in them. 
 
 4. The Eocene, or older tertiaries. The beds thus designated 
 are a very variable series, consisting, in England and Belgium, of 
 stiff clays alternating with sand, and resting on coarse sand and 
 gravel ; and, in Paris, of a number of limestones and marls, alter- 
 nating with gypsum and silicious strata. They are deposited in 
 basin-shaped depressions in the older rocks, and in England some 
 portion of them has been so greatly disturbed, that the beds are 
 actually vertical. 
 
 5. The older tertiaries of England are chiefly confined to three 
 masses, contained in trough-shaped basins, called respectively, the 
 
 . London, the Hampshire, and Isle of Wight basins ; a stiff clay 
 predominates in them, and, from being very abundant near Lon- 
 don, is known as the " London day''' The London clay often, 
 but not always, rests on a series of sandy and gravelly beds, in- 
 closing bands of potters' clay, to which the name of Plastic clay 
 has been given. 
 
 6. The greatest development of eocene strata in the United 
 States occurs in Virginia, North and South Carolina, Georgia, and 
 Alabama. In Virginia these beds consist of greenish sands, nearly 
 identical in appearance with a portion of the creta'ceous series, and 
 of the same mineral composition ; and a little further to the south 
 a continuous formation of white limestone ("Santee limestone") 
 occurs, which is of no great thickness, and which varies in hard- 
 ness, and is composed of comminuted shells, but so closely resem- 
 bling certain creta'ceous beds of the secondary period in New Jer- 
 sey, as to have been frequently mistaken for them. But this 
 resemblance does not extend to the fossil contents of the beds, 
 
 3. How is the tertiary period divided? What is meant by Eocene? 
 What by Miocene ? What by Pliocene ? 
 
 4. What are the characters of the Eocene beds ? How are they de- 
 posited ? 
 
 5. What are the chief localities of Eocene beds in England ? What is 
 London clay ? 
 
 6. In what parts of the United States do Eocene strata exist? 
 
TERTIARY FORMATION. PARIS BASIN. 79 
 
 which are in many instances analogous, or the same as those of 
 the eocene formations in other parts of the world. 
 
 7. The geological position of the city of Paris resembles that 
 of London, each being situated upon an extensive and important 
 group of tertiary strata, which occupies a depression or basin in 
 the underlying chalk. The nature of the two deposits is, how- 
 ever, totally different, the deposit being characterized in England 
 by great accumulations of argillaceous matter, which form the 
 London clay, while in the neighbourhood of Paris there is a varied 
 series of limestones and marls, alternating with important beds of 
 gypsum and silicious matter. 
 
 8. The depression in the chalk forming the celebrated Paris 
 basin so frequently named by geologists, which is filled up by these 
 strata, is nearly one hundred and eighty miles in its greatest length, 
 and about half that in breadth. The surface of the chalk is usually 
 covered by broken and rolled flints, often cemented by a silicious 
 sand into a kind of breccia; and these flints seem to mark the 
 action of the sea upon reefs of chalk before the commencement of 
 the tertiary epoch. 
 
 The order of stratification of the Paris basin is represented in 
 the following table. 
 
 8. Upper marine sands. 7. Upper fresh water sands. 
 
 W- y, ' 
 
 6. Green marls. 
 5. Gypsum. 
 
 i { Calcaire siliceux, or o ( Calcaire grossier, or 
 
 ' ( Fresh water limestone. ' I Marine limestone. 
 
 2. Plastic clay. 
 1. Chalk. 
 
 9. Above the chalk we find, first, deposits of plastic clay, so 
 called because varieties of it are well suited for the manufacture 
 of pottery. In the neighbourhood of Montereau on one side, be- 
 tween Houdan and Dreux on the other, it is remarkable for its 
 whiteness and purity, and is used in the fabrication of the finest 
 porcelain. Around Paris it is coloured and impure, and suitable 
 only for coarse pottery. These clays contain lignite, in which we 
 see, perhaps for the first time, mingled with numerous co'nifers, 
 phanero'gamous monocotyledons, true palms, and some dicotyle- 
 dons. Marine, as well as fresh water shells, are found in its upper 
 part. 
 
 7. In what respects does the geological position of Paris differ from that 
 of London. 
 
 8. What is the extent of the Paris basin ? 
 
 9. What lies next above the chalk in the Paris basin ? What are the 
 characters of plastic clay ? To what uses is it applied ? 
 
80 
 
 TERTIARY FORMATION PARIS BASIN. 
 
 10. Above the plastic clay 
 we find thick deposits of marine 
 limestones, more or less arena- 
 ceous in structure, the different 
 beds of which may be easily 
 distinguished by their characters. 
 These limestones contain a pro- 
 digious quantity of mil'liolites 
 (fig> 147) extremely small 
 
 Fig. 147. Mil'liolites (greatly mag- 
 
 nified). 
 
 shells the most of which do 
 not attain .03937 of an inch in 
 size, and yet they constitute a 
 great number of genera. These 
 serve, in a manner, as paste to 
 an immense number of shells 
 of different genera, which are 
 more analogous to creatures now 
 living than any we have hither- 
 to mentioned : three per cent, 
 of them are even identical with 
 species now existing in the 
 neighbouring seas. The cerithia 
 are here so abundant that the 
 formation is sometimes known 
 by the name of cerithia lime- 
 stone, although these same fos- 
 sils are found in many other de- 
 posits. There are certain spe- 
 cies which are characteristic, 
 that is, they are always found 
 wherever these deposits exist : 
 such, for example, is the Ceri'- 
 thium giga'nteum (fig* 148), 
 
 Fig. 148. Ceri'thium giga nteum 
 (very much reduced). 
 
 10. What lies above the plastic clay ? What are mil'liolites ? What 
 proportion of fossil shells found in eocene strata resemble living species ? 
 What is Cerithia limestone ? 
 
FOSSILS. PARIS BASIN. 
 
 sometimes twenty-seven inches in length, the extremity of which 
 is almost always worn or broken by the friction and knocks occa- 
 sioned by the movement of the animal. Among other shells, of 
 which there are a great many species, it is difficult to name any 
 which are absolutely characteristic ; among the most common are 
 the Turrite'lla imbrica- 
 ta'ria (Jig. 149); the 
 ampulla' ria acuta (fig- 
 150) ; the terebe'llum 
 fusifo'rme, (fig. 151) ; 
 the milra SCabra (fig- Fig. 149. Turrite'lla imbricata'ria. 
 
 152); the crassatella sulca'ta (Jig- 153); the car'dium porulo'sum 
 
 Fig. 15QAmpulla'ria 
 acuta. 
 
 Fig. 151. Terr die' Hum 
 fusifo'rme. 
 
 Fig. 152.Mitra 
 scabra. 
 
 (Jig. 154). With 
 
 these species are 
 
 found a great many 
 
 others, which have 
 
 been described and 
 
 figured in a great 
 
 many books on the Fig. 153.Crassate'lla sulca'ta. 
 
 environs of Paris ; there are species which are much more com- 
 
 Fig. 154. Car'dium porulo'sum. 
 
82 PARIS BASIN ANOPLOTHERIUM. 
 
 mon than those named, but some of them are not found every- 
 where, and others are seen first in the superior formations. 
 
 11. Above the marine limestone, or rather parallel with it, we 
 find what is named fresh-water or silicious limestone, so called be- 
 cause there is mingled in it a considerable quantity of silex, some- 
 times uniformly disseminated, and at others forming here and there 
 more or less voluminous masses (fig. 155), which constitute the mill- 
 
 Millstone. 
 
 Fig. 155. Fresh-water limestone, with masses of millstone without shells. 
 
 stone without shells, which is wrought into millstones. Fluviatile shells 
 are found in the lower parts of this bed, such as lymnea and planorbis. 
 12. The next group in the general series of Paris basin rocks 
 consists of white and green marls, with a considerable quantity of 
 gypsum, the latter being chiefly developed in the centre of the 
 basin. The upper parts both of the marine and fresh-water lime- 
 stone alternate occasionally with marls ; but the latter form, on the 
 whole, a distinct overlying group of fresh-water origin, and contain 
 land and fluviatile shells, fragments of wood, and great numbers 
 of the bones of fresh-water fishes, of crocodiles, and other reptiles, 
 of birds, and even of quadrupeds, the latter being usually isolated 
 and often entire. The gypsum beds having been extensively 
 quarried for the manufacture of "plaster of Paris" (obtained by 
 burning the gypsum), they have yielded a multitude of these 
 mammalian remains, which formed the base of the great dis- 
 coveries of Cuvier so that the investigation of them by that 
 anatomist may even be considered to have laid the foundation of 
 the science of Paleontology, so far as it is dependent on sound 
 principles of analogy. It is chiefly in the lower parts of the 
 gypsum that these extinct quadrupeds are found. Such, for ex- 
 ample, are the anoplo- 
 the'rium and palco- 
 thefriwn, pachyder- 
 matous animals, more 
 
 or less approaching to 
 the rhinoceros and ta- 
 
 pir, of which there 
 were several species. 
 The common anoplo- 
 Fig. 156. Skeleton of the Anoploihe'rium commune, the'rium (fig. 156 
 
 11. What is the position of the fresh- water limestone of the Paris basin ? 
 
 12. What is found next above the limestones of the Paris basins ? What 
 is plaster of Paris ? What fossils are found in the gypsum ? What is the 
 Anoplothe'rium ? 
 
PALEOTHERIUM. MIOCENE. 
 
 83 
 
 from the Greek, a, without, oplon, arm, and therioh, animal), was 
 of the size of an ass, of a heavy form, and with thick short legs 
 and a long tail ; some species had slender legs, and must have been 
 swift and active ; and others of the size of a hare, and even of a 
 guinea-pig, which were nevertheless adult. 
 
 13. The paleothe' rium (fig. 157 from the Greek, palaios, 
 ancient, and therion, a beast), was of the size of a horse, and form 
 of a tapir ; species of various size, both large and small, existed. 
 
 Fig. 157. Skeleton of the Paleothe'rium magnum. 
 
 14. Above the gypsum we find another more modern group, 
 consisting of two formations, one marine and the other fresh- water. 
 They are composed of marls, mica'ceous and quartzose sands, and 
 layers of flint. These beds of sand are often of great thickness, 
 and are at first coloured by oxide of iron, and then white and pure: 
 they frequently form masses of sandstone, sometimes without or- 
 ganic remains, or only rolled shells of the marine limestone ; some- 
 times, on the contrary, they contain the casts or impressions of 
 shells. On these sandstones repose new lacu'strine deposits, form- 
 ing sometimes shell millstone, filled with lymnese (fig. 158), 
 plano'rbis (fig. 159), and seeds ofchara, or gyro'gonites (jig. 160). 
 
 Fig. 158. Lymnea 
 longisca'ta. 
 
 Fig. 159. Plano'rbis 
 cuom'phalus. 
 
 Fig.lGQ.Chara medi- 
 cage'nula ? (greatly 
 magnified.) 
 
 15. The Miocene, or middle tertiary period. During- this 
 second part of the tertiary period both terrestrial and aquatic ani- 
 
 13. What is the Paleothe'rium ? 
 
 14. What lies above the gypsum ? 
 
84 MIOCENE, OR MIDDLE TERTIARY. 
 
 mals became more numerous, and more like those of our own 
 times ; then there existed a great number of mollusks, belonging to 
 species which still inhabit the seas of the present epoch. 
 
 16. In England the miocene tertiary is represented by a thin 
 and variable heap of gravelly strata, called the " crag formation," 
 which is divided into three parts. The lowest is called coralline 
 crag, because a great many coral remains are found in it ; the 
 next is the red crag, distinguished by its deep ferru'ginous stain ; 
 the uppermost is named Norwich, or mammali'ferous crag, which 
 is of more recent origin than the red crag, and contains bones of 
 large mammals, and occasionally fresh-water shells. 
 
 17. An extensive series of miocene beds occupies the whole 
 surface of both shores of the Chesapeake Bay, a hundred miles 
 north and south, and fifty miles wide. A similar series occurs in 
 Virginia. The lowest beds of the Chesapeake series are argilla'- 
 ceous, and the uppermost are sandy ; both series abound in fossils, 
 and when met on the side of a river they are sometimes found to 
 consist of little else than shells and the remains of zo'ophytes, often 
 in a high state of preservation. 
 
 18. The miocene tertiaries prevail extensively on the continent 
 of Europe ia, various river basins. They occupy a considerable 
 portion of the west of France, filling up the basins of the Loire 
 and Garonne ; they fill up also a great part of the valley of the 
 middle Rhine, and the whole of the great valley of Switzerland, 
 between the. Alps and the Jura chain ; and from Switzerland they 
 extend towards the north-east, following the course and partly fill- 
 ing up the valley of the Danube. From point to point they may 
 here be traced spreading out into extensive series near Vienna, and 
 in Styria, and occurring again in the plains of Hungary ; they are 
 also found in Poland and Russia ; they appear both in northern 
 and southern Italy, and on the shores and islands of the Mediterra- 
 nean. 
 
 19. The miocene beds of the basin of the Loire are chiefly de- 
 veloped near the city of Tours, and in the Touraine district, where 
 they consist for the most part of broken shells ; these beds, how- 
 ever, sometimes afford a building stone, the comminuted shells 
 being mixed with sand and gravel, and cemented by calcareous 
 matter. In Switzerland there is a series of tertiary sandstones of 
 the miocene period ; and between the lakes of Geneva and Lu- 
 
 15. What is remarked of the miocene period, as respects animals ? 
 
 16. How are the miocene beds represented in England ? What is coral- 
 line crag ? What is red crag ? What is Norwich crag ? 
 
 1 7. In what part of the United States do we find examples of miocene 
 beds? 
 
 18. Where do we find miocene beds in Europe ? 
 
 19. What is the nature of the miocene beds in Switzerland ? What is 
 molasse ? 
 
MIOCENE FOSSILS. 85 
 
 cerne these beds consist of a coarse conglomerate, called " nagel- 
 fluhe," passing into a finer sandstone (the "molasse" of French 
 geologists), which is usually soft and incoherent, but sometimes 
 sufficiently hard to be used as a building stone. Various beds of 
 lignite and marl are irregularly distributed through the molasse, 
 which are evidently of fresh-water origin. 
 
 20. The marine deposits of the miocene strata, although abound- 
 ing in shells, do not contain as great a number of species as the 
 marine limestone of the Paris basin; yet, eighteen per cent, of 
 these species are identical with those now Jiving in the neighbour- 
 ing seas. There is often the strongest analogy between these new 
 deposits and the lower limestones, with which they have been 
 confounded ; yet, if we do frequently observe a common aspect, 
 and often find the same shells in both, there is, nevertheless, es- 
 sential differences between them. In one case, we no longer find 
 species characteristic of the lower deposits ; there is no ceri'thium 
 giga'nteum, no car'dium porulo'sum, &c. : in the other, we find 
 new remains which we did not meet with before, such as the 
 Bala'nus cra'sus (Jig. 161), the Rostella'riapespelica'ni (Jig. 162), 
 the Pe'cten pleurone'ctes (Jig. 163), &c., which are never found in 
 the Paris basin, but exist in the subapennine formation. 
 
 Fig. 161. Bala'- Fig. 162. Rostella'ria Fig. 163. Pe'cten 
 
 mis crasus. pespelica'ni. pleurone'ctes. 
 
 21. The strata belonging to this period of the tertiary formation 
 contain divers species of paleothe'rium, but differing from those 
 found in the Paris gypsum. Here we also find several other species 
 of animals, which constitute genera, no trace of which is met with 
 in the preceding formation, and which totally disappear in the suc- 
 ceeding epoch. Here we find the remains of mastodons (from 
 the Greek, mastos, a nipple, and odous, tooth), animals analogous 
 
 20. What is the character of the fossils of these beds ? What proportion 
 of them resemble recent or living 1 species? 
 8 
 
86 
 
 MASTODON. DINOTHERIUM. 
 
 to the elephant, but whose teeth (Jig. 
 164) have crowns studded with conical 
 or nipple-like points, instead of being 
 flat. On the miocene beds we also 
 find the gigantic Dinotherium (from 
 the Greek, dinos, circular, and therion, 
 a beast), an animal resembling the tapir, 
 which is remarkable by having the 
 tusks turned downwards (fig- 165). 
 It was first found in Hesse, afterwards 
 
 Fig. 164. Tooth of a ma' sto- near Auch by M. Lartet, who sub- 
 don (reduced). sequently found in the same place the 
 
 bones of monkeys. 
 
 Remains of the rhi- 
 noceros, of the hippo- 
 
 po'tamus, and of the 
 
 castor are also found 
 
 in these deposits. 
 
 "The Dinothe'rium is 
 the largest of the terres- 
 trial mammalia of whose 
 existence we have any 
 positive knowledge, but 
 as it is not a matter of 
 absolute certainty at pre- 
 sent of what nature its ex- 
 tremities may have been, 
 we are hardly in a condition to speak very decidedly of its general appearance 
 or habits. It is chiefly known by the' fragments of the head and teeth, 
 which exhibit a near approach, the former to the ceta'cean tribe, and the 
 latter to the tapir ; but there is a remarkable and very striking anomaly in 
 the existence of two large and heavy tusks placed at the extremity of the 
 lower jaw, and curved downwards like the tusks in the upper jaw of the 
 walrus. It is probable, from the size and position of these tusks, as well 
 as from the structure of the bones of the head, that the animal was aquatic 
 in its habits, living almost entirely in the water, and feeding on such succu- 
 lent plants as it could there obtain. 
 
 " The length of the Dinothe'rium is calculated to have been at least as 
 much as eighteen feet, and its proportions were, probably, very much the 
 same as those of the great American tapir. It was provided with a trunk, 
 which seems to have been short, but extremely large and powerful, and 
 capable of being employed to tear up the food which the tusks, acting' like 
 pick-axes, may have loosened." Ansted. 
 
 22. The miocene is very rich in combustible material ; to it 
 belong the lignites of Languedoc, of Provence, Switzerland, and 
 most of those of Germany as well as the masses of earthy com- 
 
 Fig. 1 65. Lower jaw and tusJc of 
 the Dinothe'rium giga'nteum. 
 
 21. What fossil animal remains are found in these beds ? What is the 
 Dinothe'rium ? 
 
LIGNITES. MOLASSE. 
 
 87 
 
 bustible in the neighbourhood of Cologne. All these Hgnites 
 appear to have been formed chiefly from con'ifers, the structure of 
 which (fig. 166) may be recognised in the mass of combustible 
 itself, or in the wood disseminated through various deposits. 
 C. 
 
 Fig. 166. Structure of the wood of con'ifers. 
 fl. Part of a transverse section of natural size. 
 
 b. Part of the same section seen under a microscope. 
 
 c. Longitudinal section, in the direction from B to C, also magnified. 
 
 d. Section in the direction from A to B. 
 
 23. But the tertiary sandstones of the miocene period (the mo- 
 lasse) also contain a great quantity of dicotyledonous plants, the 
 wood of which is here and there found disseminated, sometimes in 
 a silicious state, and clearly exhibiting the proper tissue or struc- 
 ture of this class of plants (fig. 167), particularly characterized 
 by the presence of large lono-i'tudinal vessels. We also find leaves, 
 C. 
 
 a. B. b. 
 
 Fig. 167. Structure of the wood of dicoty'ledons. 
 
 a. Part of a transverse section of natural size. 
 
 b. Part of the same section, seen under the microscope, showing the large 
 vessels. 
 
 c. Longitudinal section in the direction from A to B, showing the struc- 
 ture of the medullary rays, and that of a large vessel. 
 
 22. What is lignite ? From what family of plants were these lignites 
 probably formed ? How is this family of plants recognised ? 
 
 23. What description of plants exist in the tertiary sandstone of the 
 miocene period ? 
 
FOSSILS. 
 
 Fig. lG8.Leafofanun 
 determined elm. 
 
 the midst of 
 deposits of 
 
 often in great numbers, 
 in the clays which ac- 
 company the lignites, 
 in the characters of 
 which we distinctly re- 
 cognise existing dicoty'- 
 ledons, such as walnuts, 
 maples, elms, birches, 
 fec. (Jig*. 168, 109). 
 Even fruits are found 
 which re distinguish- 
 ed, often with difficulty, 
 from those now grow- 
 ing. 
 
 24. We also find in 
 {h[s f ormatiori5 eilher fo 
 
 Fig. 169. Complonia combustible -- 
 a'cutilo'ba. ^ j n those O f 
 
 Liblar near Cologne, or in the ar- 
 gilla'ceous or sandy matter of the 
 formation, the remains of monoco- 
 ty'ledonous plants : there is wood 
 presenting the structure of the 
 palms, that is, an assemblage of 
 woody fasciculi (bundles), longi- 
 tudinally arranged, without regard Fi 
 to regularity, in the middle of eel- 
 
 170. Structure of the icood 
 
 Fig. 171. Palmacites Lamanonis. 
 
 lular tissue, as seen (fg. 
 170). Leaves like the 
 representation (fig. 171) 
 are also met with. We 
 find, too, in the miocene 
 gypsum of the same na- 
 ture as that of the Paris 
 basin, which has led to 
 the supposition that they 
 were of the same epoch ; 
 but besides this section of 
 country being formed of 
 the "molasse," the or- 
 ganic remains are not of 
 the same species. 
 
 Towards the close of the 
 miocene, or second epoch of 
 
 24. How do we recognise the previous existence of iiioiiocoty'ledonous 
 plants from their fossil remains ? 
 
PLIOCENE. 89 
 
 the tertiary period, a new upheaval appears to have taken place in the 
 region of the Alps. A part of this complicated chain of mountains had 
 then long existed. Thus the Alps of Provence and of Dauphiny, which 
 belong to a system of which Mont-Viso is the most remarkable point, date 
 from the interval elapsed between the deposit of the inferior and upper lay- 
 ers of the creta'ceous system ; other portions of the Alpine region were 
 raised up at the same time as the Pyrenees, that is, after the creta'ceous 
 period ; for example, the neighbourhood of Castel-Gomberts, and in the 
 mountains which connect the Alps to the Jura, we perceive traces of an 
 upheaval contemporaneous with that of Corsica, which occurred after the 
 deposit of the eocene, or first period of the tertiary formation ; but the 
 greater part of this majestic barrier between Italy and the north seems to 
 have acquired its present configuration, and to have attained the immense 
 height we now observe, in more recent times. The chain of the western 
 Alps appears to have been upheaved after the deposit of the miocene or 
 second series of the tertiary ; and the chain extending from Valais towards 
 Austria appears to be of still more recent origin. 
 
 Dating from the geological convulsion which gave to the western Alps 
 their existing prominence, and at different points produced the elevation of 
 the " molasse," and other tertiary strata of the miocene period, as well as 
 those of more ancient epochs, Europe presented a great continental sjfcce ; 
 and during the period of tranquillity which followed this catastrophe, marine 
 deposits did not take place except on the shores or in gulfs not far from the 
 centre of this region, as in the subapennine hills, in some parts of Sicily, and 
 on a portion of the coast of England ; but sedimentary deposits occurred 
 in the basins or valleys of still existing rivers, and in some lakes of fresh 
 water which a more recent geological revolution has caused to disappear. 
 
 25. The Pliocene, or newer tertiary. In Europe the pliocene 
 is chiefly represented in south Italy, in the Morea, and in the isl- 
 ands of the eastern archipelago ; and important contemporaneous 
 beds exist in the valley of the lower Rhine, near Bonn, and a por- 
 tion of central France, as well as in southern Russia. 
 
 26. The pliocene beds are not all, however, of the same age, 
 and the beds so called must have been in the course of formation 
 for a very long period. Those of Italy admit of being subdivided 
 into two groups, the older of which is called the sub-apennine, and 
 attains a great thickness near Parma, exhibiting a considerable 
 number and variety of fossils. These beds consist for the most 
 part of greyish, brown, or blue marls, containing calcareous mat- 
 ter, and overlaid by thick sandy beds. The Sicilian beds are dis- 
 tinctly newer than these, and are equally extensive. Marls, with 
 occasional limestone, form the great mass of the materials of these 
 strata. Like the subapennines they are richly fossili'ferous, but 
 are chiefly characterized by their shells. A fresh-water bed of 
 the newer period is found at (Eningen, on the lake of Constance, 
 
 and contains numerous remains of fishes, and some fragments of 
 land animals. 
 
 27. From the eocene, or deposits of the Paris basin, there is a 
 
 25. In what parts of Europe are the pliocene beds represented ? 
 
 26. Are all pliocene beds of the same age? What is the character of the 
 Sicilian beds ? 
 
 8* 
 
90 
 
 FOSSILS. 
 
 progressive increase in the number or proportion of recent species 
 found : in the Paris basin three per cent, of the fossil shells are 
 analogous to the shells now .existing ; in the miocene, eighteen per 
 cent., and in the pliocene fifty per cent, of the fossil shells resem- 
 ble existing species. There is scarcely any analogy between the 
 shells of the Paris basin limestone and those of the subapennine 
 hills. Besides the Balanus crasus (Jig. 161), and the Rostella'- 
 ria pespelica'ni (Jig. 162), we may cite the Pleuro'toma rota'ta 
 (fig. 172), the Buc'cinum prisma'ticum (fig. 173), the Volu'ta 
 Lambe'rti (fig. 174), &c., and almost all the shells 01 the Mediter- 
 ranean. 
 
 Fig. 172. Pleura' toma Fig. 173. Buc'cinum 
 rota'ta. prisma'ticum. 
 
 Fig. n4Vplu'la 
 Lambe'rti. 
 
 Fig. I15.Murex 
 alveola'tus. 
 
 Fig. 176. Astarte Bas- 
 teroli. 
 
 Fig. m.Cy'prea 
 coccinelloides. 
 
 The deposits alluded to also contain masses of lignites, which arc advan- 
 tageously worked in different localities. Some offer regular layers of a sort 
 of compact coal (brown coal), accompanied by fresh- water shells, indicating 
 a tranquil deposit in lakes ; but the greatest number contain only irregular 
 masses of wood, some of which present the texture of the con'ifers. A 
 great number of leaves, analogous to those of existing dicoty'ledons, are 
 also found. 
 
 27. What proportion of fossils found in the eocene, miocene, and plio- 
 cene respectively, resemble species now living ? 
 
BONE CAVERNS. 91 
 
 28. The pliocene beds of the United States seem to belong 
 chiefly to a very modern period ; they exist to a great extent in 
 several localities. At the mouth of the Potomac, in Maryland, is 
 a series of clay beds, alternating occasionally with sand. All the 
 fossils found in these beds are identical with those species found 
 living on the neighbouring sea-coast, a positive indication of the 
 newness of these beds. Similar beds exist at Niagara and in 
 Kentucky, and in other parts of North America ; in all cases the 
 recent deposits are very striking. 
 
 29. While these lacu'strine deposits were tranquilly forming be- 
 neath the waters, the then uncovered surface of the earth was in- 
 habited by hyenas, cavern bears, hairy elephants, ma'stodons, rhi- 
 noceroses, hippopo'tami and other animals belonging to genera still 
 in existence, but the species of which are now lost ; they appear 
 to have been destroyed in the geological revolution which raised 
 up the principal chain of the Alps, and gave to these mountains 
 their present configuration, and its present shape to the European 
 continent. It is probable, too, that the same revolution destroyed 
 the multitude of animals whose bones are found at the bottom of 
 certain caverns or fissures in the rocks, where they are buried in a 
 sort of calcareous cement, ordinarily of a reddish colour. 
 
 30. BONE CAVERNS. The most ancient caverns, celebrated for 
 the remains of mammals which they contain, are those of Harz 
 and of Franconia ; but since Dr. Buckland has shown the pro- 
 priety of removing the mud, sands, rolled flints-, stala'gmites, &c., 
 which often cover the bone collections, these remains have been 
 found everywhere, even in places where they had not been pre- 
 viously supposed to exist. 
 
 31. Most of these caverns appear to have had one or more 
 lateral openings, affording easy entrance to the animals that fre- 
 quented them, as places of refuge, to devour their prey, and finally 
 they came to them to die. Here their bones accumulated through 
 a great many generations, and we now find them buried in a dark 
 earth, in or on which we recognise their dejections. Often we 
 find among the bones of a certain genus of animals other bones, 
 having upon them the print of teeth, showing they had been the 
 prey of the first. The greater number of these bones belong to 
 the bear tribe, two species of which were larger than any now 
 existing ; or to the hyena tribe, also larger than those now known. 
 Sometimes one, and sometimes the other of these genera predomi- 
 nates ; a species of wolf abounds in the bear caverns of Galenreuth 
 in Franconia : other carni'vora, of the genus dog, and those of the 
 genus cat, including species of cougars, are everywhere in small 
 
 28. In what parts of the United States do pliocene beds exist? 
 
 29. What kind of animals inhabited the land while theje-Ja&tt^gtcine de- 
 posits were being formed ? 
 
 30. What are bone caverns ? Jf r HE 
 
 31. What are the features of bone caverns? ' 81 Kj I y p D Q |TY 
 
92 
 
 SUPERFICIAL DEPOSITS. 
 
 numbers. The remains of rodents, of ruminants, also of large 
 pachyderms and of birds, which have been dragged as prey to 
 these resorts, are also found. 
 
 SUPERFICIAL DEPOSITS. 
 
 " The regularly stratified deposits, of whatever geological period they 
 may be, are in most parts of the world covered up, more or less, by a con- 
 siderable mass of heterogeneous material derived from the degradation of 
 the more ancient rocks. This mass is generally unstratified, and deposited 
 in irregular heaps, partially filling up valleys, covering low tracts of level 
 country, and sometimes even capping low hills, but almost always bearing 
 marks of having been transported from a distance over ranges of high 
 land, although not without some reference to the present physical features 
 of the country over which it has travelled. 
 
 "Occasionally the fragments which have been thus conveyed are of large 
 size and angular, and in this case they are called "boulders," or "erratic 
 blocks ;" but such masses have not generally travelled to any very con- 
 siderable distance from the parent rock. The transported fragments are 
 much more commonly of small size, and rounded, as if by mutual attrition, 
 at the bottom of the sea ; and in this state they have been often carried to 
 very great distances, and are found many hundred miles from the place 
 whence they seem to have been derived. They are then called ' gravel,' 
 and are riot unfrequently mingled with bones and fragments of bones of 
 large quadrupeds." Ansted. 
 
 32. These superficial deposits are termed DRIFT, and comprise 
 deposits of water-worn, transported materials, consisting of gravel, 
 boulders, sand, clay, &c. 
 
 33. Drift is divided into DILU'VIUM, or ancient drift, and ALLU'- 
 VIUM (from the Latin, alluo, I wash upon), or modern drift. 
 
 34. The DILU'VIUM 
 
 (formed from the Latin, 
 diluo, I wash away) co- 
 vers up the tertiary depo- 
 sits, and contains fossils 
 whose origin dates back 
 to a period not very long 
 antecedent to the present. 
 In fact the dilu'vium, to 
 a certain extent, unites 
 the tertiary with the re- 
 cent period. It contains 
 the bones of large mam- 
 mals, both of extinct and 
 recent genera and spe- 
 cies. Among them we 
 may perhaps place the 
 enormous megathe'rium 
 Fig. 178. Skeleton of the Megatherium. (fig- 178 from the 
 
 32. What is meant by drift ? 
 
 33. How is drift divided ? What is the difference between dilu'vium and 
 allu'vium ? 
 
MEGATHERIUM BOULDER FORMATION. 93 
 
 Greek, mcgas, great, and therion, beast), which was not less than 
 eighteen feet long and nine feet high. The skeleton is analogous 
 to that of animals of the order edentata. The thigh-bone in the 
 megathe'rium is nearly three times as great as the largest known 
 elephant ; the bones of the instep and those of the foot are of cor- 
 responding size, the heel-bone projects back nearly eighteen inches, 
 and the small bones of the foot advanced as much forwards. The 
 third toe is provided with a socket to receive a claw, the sheath of 
 which measures thirteen inches in circumference, and the core on 
 which the nail was attached is ten inches in length. The fore 
 limbs were well adapted for grasping the trunk or larger branches 
 of a tree. This animal was slow in its movements, and probably 
 fed on roots, which its teeth were admirably adapted for grinding. 
 
 35. To the diluvial drift are also referred the great collections 
 of bones of the Icy ocean, on the coasts of Siberia and on the 
 neighbouring islands : there a number of enormous animals, their 
 flesh preserved through thousands of years, lie buried in sands 
 consolidated by perpetual ice ; in the same situations have been 
 found stags and horses, the elephant and rhinoceros, covered with 
 hair, seemingly indicating that the species which then lived in 
 northern climates were enabled to bear, from being clothed in fur, 
 lower temperatures than those with naked skins which now inhabit 
 southern Asia and Africa. The tusks of these elephants of the 
 ancient world are sought for the ivory they afford, and compete, in 
 commerce, with those of modern elephants. 
 
 It is perhaps to the dilu'vium we must refer those immense masses of 
 rolled debris which contain gold, platina, and the diamond, in Brazil, in 
 Africa, in India, and in the Oural mountains, as well as the arena'ceous 
 veins of tin in Cornwall arid Mexico. 
 
 36. The BOULDER 'FORMATION, or ERRATIC BLOCK FORMATION, 
 also, is regarded as a part of the diluvial drift. A great part of 
 the plain of Switzerland is covered at intervals by fragments of 
 rock, measuring about a cubic yard, which strew the plain, and 
 dot the sides of the Alpine ravines, and rise on the opposite side 
 of the Jura range, even to an elevation of several thousand feet 
 above the sea. The most concentrated distribution of these blocks 
 seems to be near the town of Neuchatel, but similar masses are 
 also found on the summit of the Mont Saleve, behind Geneva. 
 It is very remarkable that a belt of fragmentary masses (not few 
 or small, but countless and gigantic), differing entirely in character 
 from the formation on which they rest, should be found lying on a 
 steep, almost precipitous slope of nearly bare or thinly -covered 
 rock. One of the blocks behind Neuchatel, eight hundred and 
 fifty feet above the lake, is of granite, and measures between fifty 
 
 34. What is the position of diluvial drift ? What is the megathe'rium ? 
 
 35. What other fossils are referred to the diluvial drift ? 
 
 36. What is the nature of the Boulder formation ? 
 
94 ALLUVIUM, OR MODERN DRIFT. 
 
 and sixty feet in length, by twenty feet broad, and forty feet high, 
 while between the Jura and the Alps blocks still larger are in 
 many places to be found one, out of a great number together in 
 the canton of Berne, measuring 01,000 cubic feet. 
 
 37. Erratic blocks and gravel cover the plain of central Europe 
 and the steppes of Russia. Almost the whole surface of North 
 America, as far as it has been examined, has been found covered 
 with gravel, pebbles, and boulders, varying greatly in thickness, 
 and obviously of the same origin as similar deposits in Europe ; 
 and a region which has been called the great Atlantic plain, ex- 
 tending between the Alleghany mountains and the Atlantic ocean, 
 together with the lower part of the great valley of the Missisippi, 
 appear to* be the districts where it conceals the underlying deposits 
 to the greatest depth. 
 
 On the borders of Lakes Erie and Ontario there are very de- 
 cided marks of the great drift which has elsewhere overspread 
 North America, and the boulder formation, containing marine 
 shells, extends into the valley of the St. Lawrence, as far down as 
 Quebec, and at a height of at least three hundred feet above the 
 sea-level. Below Gluebec there are large and far-transported boul- 
 ders in beds, both above and below these marine shells, and 
 wherever the contact of the drift with hard subjacent rocks is seen, 
 these rocks are smoothed and furrowed on the surface, as they are 
 in similar positions in northern Europe. 
 
 38. ALLU'VIUM, or MODERN DRIFT. In many parts of North 
 America the valleys are filled up to a depth of twenty or thirty 
 feet with unconsolidated beds of earth of various kinds, and the 
 heteroge'neous mass contains in it abundant remains of large 
 pachyde'rmatous animals, not now living in the country, but asso- 
 ciated with, and overlaid by other and similar beds, in which occur 
 the bones of buffaloes, that have within a fe\v years been driven 
 westward by the advancing steps of civilized man. These beds 
 all belong to the same geological period, or nearly so, and a descrip- 
 tion of one will be sufficient to give an accurate notion of a multi- 
 tude of similar bogs and soft meadows in many of the western 
 states. The most remarkable is that known as the " Big Bone 
 Lick" in Kentucky. 
 
 39. The Big Bone Lick occupies the bottom of a boggy valley, 
 kept wet by a number of salt springs, which rise over a surface of 
 several acres, and the substratum of the country is a fossili'ferous 
 limestone. At the Lick the valley is filled up to the depth of not 
 less .than thirty feet with beds of earth, the uppermost of which is 
 a yellow clay, apparently the soil brought down from the high 
 grounds by rains and land floods. In this yellow earth, along the 
 
 37. Where is the Boulder formation met with ? 
 
 38. What is allu'vium ? 
 
 39. What are the characters of the Big Bone Lick of Kentucky ? 
 
EIGHTH GEOLOGICAL EPOCH. 95 
 
 water-courses at various depths, the bones of buffaloes and other 
 modern animals are often found quite entire. Beneath the clay is 
 another layer of a different soil, bearing the appearance of having 
 been formerly the bottom of a marsh. It is more gravelly, darker 
 coloured, and softer than the other, and in it, or sometimes in a 
 stratum of compact blue clay alternating with it, there are found 
 innumerable bones of large mammals, chiefly ma'stodons, but in- 
 cluding also elephants, and extinct species of animals of the ox 
 and deer tribe. In other localities the ma'stodon bones are found 
 immediately below the surface in reclaimed marshes, and they are 
 sometimes extremely perfect, sometimes broken and water-worn. 
 The Big Bone Lick would appear to have been resorted to, not 
 only in modern times by the living races, but more anciently by 
 animals now extinct, for the salt, and perhaps the food produced 
 by the marsh. The buffalo and bison are frequently known to 
 perish entrapped in these licks and swamps, and it seems evident 
 that the ma'stodon and elephant of former times must, from their 
 huge size and unwieldy forms, have been at least equally exposed 
 to the same fate. Jlnsted, Rogers, fyc. 
 
 40. Up to the present time all geologists agree in saying that in 
 the formations of this period, as well as in the most ancient rocks, 
 neither human bones nor any vestige indicative of the existence of 
 man on the face of the earth has been found, and it is, for this rea- 
 son, probable that man had not yet been created at the time of the 
 destruction of these animals. 
 
 EIGHTH GEOLOGICAL EPOCH. 
 Modern Formation. 
 
 41. New formations are now being made, either by the effusion 
 of igneous matter from the bowels of the earth, or by sediment 
 from waters, and these formations, which are contemporaneous with 
 man, constitute the modern formation. 
 
 42. Since the last great catastrophe alluded to (the upheaval of 
 the Alps), there has been a general repose, which perhaps will be 
 disturbed one day by some new geological revolution ; by the up- 
 heaval of some great mountain chain, for example, and by the 
 great rush of waters which must follow such a convulsion, new 
 lands will rise from the bosom of the ocean, and probably enclose 
 remains of the bony frame of man and of animals now existing, 
 just as the ancient formations conceal the solid remains of creatures 
 which preceded us on the earth. Even now we have proof that 
 things must pass in the present time very nearly as they did in 
 
 40. Are human bones found in a fossil state, in the formations thus far 
 studied ? What is the inference from the fact ? 
 
 41. What is meant by modern formation? 
 
 42. Are human bones any where found in a fossil state ? 
 
96 MODERN FORMATION. 
 
 ages long gone by-, for in certain modern formations, which con- 
 tinue to be formed under our eyes, we find human skeletons im- 
 bedded in the substance of the rock, and already presenting the 
 characters of fossils of the tertiary period. One of the most re- 
 markable examples of this kind has been discovered in the island 
 of Guadaloupe. 
 
 Thus far we have presented a sketch of the earth's structure as 
 revealed to us by an examination of its crust, only in reference, 
 however, to the order of superposition of its formations, resulting 
 from great geological convulsions, and characterized by the remains 
 of animals found entombed in it. When we reflect on the incon- 
 ceivable length of time it has evidently required to effect all these 
 changes, and elevate one above another gigantic stories of various 
 rocks, the imagination is startled ; when we see entire creations of 
 plants and animals covering the surface of the earth, and inhabit- 
 ing the waters, disappear after a time, leaving a few mutilated re- 
 mains as the only trace of their existence, and give place to a new 
 flora and a new population of animated creatures, destined to un- 
 dergo in turn a similar fate, we are struck with astonishment, and 
 overcome by admiration of the power of the Creator 'of things so 
 grand and so beautiful. 
 
 LESSON VI. 
 
 INFLUENCE OF INTERNAL AGENTS ON THE SURFACE OF THE EARTH. 
 
 EARTHQUAKES Description Effects of Changes of level pro- 
 duced by Upheaval and Subsidence Constant level of seas 
 Slow and progressive Subsidence General conclusions. 
 
 VOLCANIC PHENOMENA. Explosion Eruption Island of Saint 
 George Monte-Nuovo Jorullo Vesuvius Definition of a 
 Volcano Submarine Eruptions Volcan of Unalaska Crater 
 of elevation Formation of Craters Effects of upheaval 
 Form of Volcanic Islands Periods in the formation of a 
 Volcano Interior of Craters Kirauea Solfataras Volcanic 
 fishes Lava Currents Characters of Lavas Dykes Gas- 
 eous Volcanic Products Eruption of Mud Solid products 
 of Volcanoes Trachyte Obsidian Compact Lavas Po- 
 rous Lavas, $c. 
 
 1. We have spoken of formations and of their relative order of 
 superposition, and occasionally alluded to the various causes which 
 affect them. From what we have said it might be inferred that 
 the several formations are so many concentric spheres, enveloping 
 
 1. Why is it that the surface of the globe is not entirely smooth, free 
 from mountains and valleys ? 
 
DESCRIPTION OF EARTHQUAKES. 97 
 
 a mass of fire ; and such in fact might have been the case had it 
 not been for certain disturbing forces which have fashioned the 
 mountains and valleys, and caused the dry land to be lifted up 
 above the waters. Had it not been for these disturbing forces, 
 phenomena analogous to volcanoes and earthquakes, the whole 
 globe would have remained under water, and man would not have 
 been called into existence. But having seen the general structure 
 of the interior of the earth, we will study the phenomena, the dis- 
 turbing forces which modify its surface, more particularly than we 
 have yet done. 
 
 These disturbing forces are either internal or external ; first, of 
 the INFLUENCE OF INTERNAL AGENTS ON THE SURFACE OF THE 
 EARTH. 
 
 It has been already stated (page 12) that the centre of our earth 
 is a mass of fire, to the influence of which many phenomena may 
 be referred. 
 
 EARTHQUAKES. 
 
 2. Description of Earthquakes. Every one has heard of the 
 terrible scourge which in a moment reduces the most flourishing 
 cities to a heap of ruins, and sometimes upturns the neighbouring 
 country. An earthquake is often preceded by rumbling, subterra- 
 neous sounds, which are frequently heard some time before the 
 catastrophe. Tremblings more or less violent are perceived during 
 a few minutes or seconds only, which in many instances are often 
 repeated with more or less rapidity and force ; in certain cases 
 they even continue, with irregular intervals, during several days, 
 or months, or even entire years. These movements of the earth 
 are of different kinds ; sometimes they consist of jerking horizon- 
 tal oscillations, occurring at irregular intervals, sometimes of verti- 
 cal shocks, that is, in rapid and successive rising and falling of the 
 soil ; at other times of various twisting movements. Frequently 
 all the various motions take place almost at the same moment, and 
 then nothing can escape destruction. 
 
 3. Sometimes an earthquake is circumscribed in narrow limits ; 
 that which happened on the 2d of February, 1828, in the island 
 of Ischia, was not felt either in the neighbouring islands or on the 
 continent. Frequently, too, it shakes an immense surface : for 
 example, the earthquake of the 17th June, 1826, in New Grenada, 
 was felt over many thousand square leagues. Sometimes it extends 
 enormous distances, as in the case of the famous earthquake of 
 Lisbon, which was felt in Lapland in one direction, and Martinique 
 in another ; and, transversely, from Greenland to Africa, where 
 
 2. What are earthquakes ? What is the nature of the motions produced 
 by earthquakes ? What is the duration of earthquakes ? 
 
 3. What are the limits of earthquakes ? 
 
 9 
 
EFFECTS OF EARTHQUAKES. 
 
 Morocco, Fez, and Mequinez were destroyed : ail Europe expe- 
 rienced its effects at the same moment. From the different histo- 
 ries of earthquakes, many examples of this kind of propagation 
 might be adduced, extending more or less widely. It may beeren 
 concluded, from statements of facts, that the shock extends accord- 
 ing to a great circle, more or less inclined to the equator, and per- 
 haps over an entire hemisphere. 
 
 4. Effects of Earthquakes. Earthquakes, when violent, not 
 only overturn entire cities, and the most solidly built edifices, but 
 they cause important modifications" in the ground itself. Those of 
 Calabria, in 1783, furnish examples, which are the more important 
 because the facts were observed by the most distinguished men of 
 the times, such as Vicenzio, physician to the king of Naples, Gri- 
 maldi, Hamilton, Dolomieu, &c., and also by a commission ap- 
 pointed by the royal academy of Naples. All was overturned in 
 this unhappy country ; the course of rivers was interrupted and 
 changed ; houses were raised above the level of the country, while 
 others, frequently at no great distance, were sunk down more or 
 less ; edifices of great solidity were split from top to bottom ; cer- 
 tain parts were raised above others, and the foundations pushed up 
 out of the ground. Every where the surface of the earth partly 
 opened, often in long crevices, some of which were one hundred 
 and fifty yards in breadth ; some of these were isolated, sometimes 
 bifurcated frequently exhibiting other fissures perpendicular to 
 their direction (Jig. 179); some were in form of rays diverging 
 from a centre, like a broken glass (fig. 180). Some opened at^ne 
 
 Fig. 179. Fig. 180. 
 
 Crevasses and fissures produced by earthquakes. 
 
 moment of the shock, and immediately closed again, grinding be- 
 twixt their parietes the habitations they swallowed up ; others in- 
 variably remained gaping after the commotion, or, commenced by 
 a first shock, were widened by succeeding shocks. In both cases 
 it was sometimes observed that the borders of the split were on 
 the same plane, or showed a more or less projecting swelling up 
 
 4. What are the effects of earthquakes? What is the character of fis- 
 sures produced by earthquakes ? 
 
UPHEAVAL AND SUBSIDENCE. 99 
 
 Q\ 181); sometimes one of the parts is elevated much higher 
 than the other (Jigs. 182, 183), showing that one must have been 
 raised while the other was sunk. 
 
 Fig. 181. Fig. 182. Fig. 183. 
 
 Changes of level produced by earthquakes. 
 
 Again it happens that a more or less considerable extent of surface is 
 suddenly sunk, carrying down plantations and habitations, leaving yawning 
 chasms, with vertical sides, eighty or a hundred yards in depth. In certain 
 cases an immense quantity of water springs from the bottom of these cavi- 
 ties, forming more or less extensive lakes, sometimes without apparent cur- 
 rent, and sometimes giving origin to impetuous torrents. In some instances, 
 on the contrary, rivulets were absorbed by the fissures in the earth, or swal- 
 lowed for a time, or forever. 
 
 But, besides the numerous cracks and divers chasms which intercept the 
 waters, furnishing new springs, and giving them a new channel, it also 
 happens that masses of rocks, falling across valleys, arrest the waters and 
 soon form lakes in the upper part. Now, these accumulated waters make 
 new passages, either by breaking through the sides of the valley, or by en- 
 larging some fissure in the mountain ; or, they degrade, cut down, the obsta- 
 cle which retained them, and soon overturn it entirely or in part Hence 
 arise those fearful outbreaks, those impetuous torrents rolling down enor- 
 mous masses of rock, the ravages of which are as disastrous as the earth- 
 quake itself, and which, excavating new channels, or widening and deep- 
 ening those that waters before pursued, mark their course by the debris 
 which they roll down and successively deposit. 
 
 When the principal effects of earthquakes took place on the continent 
 between Oppido and Soriano, the phenomena extended as far as Messina, 
 across the straits ; more than half the city was destroyed, and twenty-nine 
 hamlets or villages were swallowed up. The bottom of the sea was sunk, 
 and disturbed at various points ; the shore was rent, and the whole ground 
 along the port of Messina was inclined towards the sea, suddenly sinking 
 several yards ; the whole promontory which formed its entrance was swal- 
 lowed in a moment. 
 
 5. Upheaval and Subsidence. The earthquakes which occurred 
 on the coast of Chile in 1822, 1835, and 1837, have produced 
 effects not less remarkable. Different parts of the coast, from 
 Valdivia to Valparaiso, that is, an extent of more than two hundred 
 leagues, were evidently elevated above the waters, as well as many 
 neighbouring islands as far as those of Juan Fernandez ; the bot- 
 tom of the sea to a considerable extent participated in this phe- 
 nomena. On the coast, rocks which had been previously under 
 water were raised two or three yards above its level, with the mol- 
 
 5. Give some examples of upheaval and subsidence produced by earth- 
 quakes. 
 
100 UPHEAVAL AND SUBSIDENCE. 
 
 lusks which lived on their surface ; rivers emptying on the coast 
 became fordable where they had been navigable by small vessels ; 
 well-known anchorages were diminished in depth to a correspond- 
 ing extent, and at different points, shoals now oppose the passage 
 of vessels of large draught where they readily floated before. 
 
 Analogous circumstances occurred in India in 1819; a hill, fifty miles 
 long and sixteen broad, was raised up in the midst of a flat country, barring 
 the course of the Indus. Further to the south, on the contrary, but parallel 
 to the same direction, the country sank, carrying down the village and fort 
 of Sindre, which nevertheless remains standing, half submerged. The 
 eastern mouth of the river became more shallow in many places, and por- 
 tions of its bed which had been fordable suddenly ceased to be so. 
 
 The history of all times and of all places furnishes us with facts of exactly 
 the same nature. Everywhere we are told of fissures in the earth, of pro- 
 found chasms, in which cities and even entire countries are swallowed, from 
 which flow mephitic gases, enormous masses of water, sometimes cold, 
 sometimes hot, sometimes even flaming. Also of plains suddenly trans- 
 formed into mountains, of shoals raised in the midst of the ocean, of moun- 
 tains rent and overturned, of mountainous regions, of hundreds of leagues 
 of rocks all at once levelled and replaced by lakes. Of water-courses 
 changed, swallowed in chasms of the earth ; of lakes which dry up by 
 breaking through their bounds, or suddenly lost in subterraneous conduits, 
 instantaneously formed. In opposition, we also learn of enormous springs 
 producing new streams, suddenly rising through a fissure of a rock, without 
 any knowledge whence the waters come : of thermal springs which have 
 become instantaneously cold ; of others, on the contrary, appearing where 
 they did not exist before. All these phenomena are so many indications of 
 fissures in the earth, which afford new channels to waters which might 
 have circulated there before. 
 
 6. Relatively to the sea-coasts, these phenomena are often men- 
 tioned by authors in a peculiar manner ; rarely do we see it expli- 
 citly announced, there is an elevation ; but the event is stated in 
 other terms, referring the effect to the most moveable element. In 
 this way authors speak of the sea having retired more or less, leav- 
 ing its bed dry, either permanently or only for an instant : some- 
 times, on the contrary, they mention that the sea suddenly over- 
 flowed more or less elevated coasts. Geologists translate these 
 indications by the term oscillation^ if the phenomenon be mo- 
 mentary, and by the terms upheaval, or subsidence of coasts, if it 
 be permanent, because they refer these effects to the solid parts of 
 the globe, and not to the sea, the level of which does not vary. 
 Nevertheless it must be borne in mind that, if these transitory phe- 
 nomena may sometimes be attributed to oscillations of the earth, 
 they may also arise from a real impulse communicated to the 
 waters of the sea, and possibly partake of both causes. We 
 know, in fact, that during earthquakes the sea is sometimes vio- 
 lently agitated, that its waters, elevated to considerable heights, 
 occasionally make fearful irruptions on the land, advancing and 
 
 6. What is meant by oscillation ? What is meant by upheaval ? What 
 by subsidence ? 
 
CONSTANT LEVEL OF SEAS. 101 
 
 retiring again, carrying devastation over a greater or less extent. 
 These impetuous movements of advance and retreat, accompanied 
 by sudden dislocations caused by subterraneous commotions in the 
 solid crust of the globe, may occasion frightful havoc. The his- 
 tory of the Grecian archipelago, of the islands of Japan, and of a 
 multitude of places, is full of disasters produced by these catas- 
 trophes. 
 
 The various effects produced by earthquakes under our eyes, and those 
 cited in the most authentic narrations, tend to confirm what is transmitted 
 to us from the most remote times, although we might state the facts in other 
 terms. Who dares formally to contradict Pliny, relating, according to the 
 historians, that Sicily was separated from Italy by an earthquake ; that the 
 island Cy'prus was separated from Syria by the same means ; and that of 
 Eubre'a (Negropont) from Bosotia, &c. ? We would not even positively deny 
 the existence of the Atlantis, swallowed by the waters, according to Egyp- 
 tian tradition, in a dav and a night. Let us rather declare, that the assem- 
 blage of observations we have, evidently shows that immense upheavals and 
 subsidences have for a long time formed part of the mechanism of nature, in 
 bringing the surface of the earth to the configuration we -now observe. 
 
 7. Constant level of seas. We have just admitted the subsid- 
 ence and upheaval of coasts, and laid down the principle that the 
 level of seas is invariable : but this last assertion being contrary to 
 opinions commonly received by the world, it is necessary to sup- 
 port it by demonstration. The laws of hydrostatics teach us that 
 a mass of liquid cannot be permanently elevated or depressed at 
 one point of its surface, but that a level must be established after 
 oscillation, great or small, ceases. Hence it follows that the level 
 of the sea cannot be stationary at one point, without its being so 
 throughout, and that the waters cannot be elevated or depressed in 
 one spot, without similar changes being experienced at all points 
 of the same basin. Now we know thousands of localities where 
 the surface of the sea has not undergone the least variation since 
 the most remote historic times ; therefore the level has not changed, 
 and its constancy is the most positive fact we are aware of, be- 
 cause it has been subject to the proof of all ages. On the other 
 hand, if we could be led to suppose, like the inhabitants of Chile, 
 seeing the manifest change on their coast, that the sea has sub- 
 sided there, we must also conclude, with the inhabitants of Cali- 
 fornia, Peru, Brazil, &c., that in those places it underwent no 
 variation. It must also be admitted that the sea has risen at the 
 bottom of the Gulf of Arabia, as it has done, in different epochs, on 
 the coasts of Portugal, in the Straits of Messina, &c. All these 
 circumstances are incompatible with each other, and opposed to 
 the laws of hydrostatics ; and hence we conclude, that instead of 
 the immutability of the ground, which an error, analogous to the 
 idea of immobility of the globe, has created, we must admit immu- 
 
 7. Does the sea always maintain the same level ? What reasons lead to 
 the opinion that the level of seas is always the same? 
 9* 
 
102 SLOW AND PROGRESSIVE SUBSIDENCE. 
 
 lability of the seas, by acknowledging that the solid surface of our 
 planet is susceptible of elevations, depressions, and all kinds of 
 disturbances. 
 
 The slow upheaval of Sweden has already been noticed (p. 20). 
 
 8. Slow and progressive subsidence. There is no doubt that, 
 for four centuries past, the western coast of Greenland is continu- 
 ally sinking, through an extent of two hundred leagues north and 
 south ; ancient buildings, both on the low islands and on the con- 
 tinent, have been gradually submerged ; and it has been frequently 
 necessary to move various establishments built near the shore, 
 farther inland. Subsidence of certain islands in the South Seas has 
 been indicated ; but in those places, so rarely visited by geologists, 
 the facts are not yet clearly established. 
 
 9. General conclusion. It must now appear to be well estab- 
 lished, that earthquakes are capable of producing great modifica- 
 tions of the earth's surface, since, within our times, vast tracts of 
 country have been elevated sensibly above the level of the sea. It 
 is not less evident there is a slow power in operation, in virtue of 
 which, different parts of our continents may also be successively 
 raised ; and that it also produces gradual sinkings as well as sud- 
 den subsidences, which are doubtless correlative phenomena. 
 
 All these circumstances, however remarkable, are, nevertheless, 
 not very astonishing, when we reflect on the enormous dispropor- 
 tion which exists between the thickness of the solid crust of the 
 globe, and the mass of melted matter it envelopes. Is it surprising 
 that such a crust, a mere rind, relatively almost as thin as a coating 
 of gold-leaf on an orange, should be disturbed in every manner by 
 the least movement of the subjacent mass, particularly if we bear 
 in mind that similar movements doubtlessly have been taking 
 place ever since the first pellicle was consolidated on the surface, 
 and all the successive crusts must have been rent in every direc- 
 tion, and therefore their mass could not afford the resistance of a 
 continuous envelope ? 
 
 VOLCANIC PHENOMENA. 
 
 10. General notion Explosion Eruption. Volcanic pheno- 
 mena are closely connected with earthquakes; they are, in a 
 manner, the final results of them. When, by the shaking and ele- 
 vation of the ground, the terrestrial crust is deeply broken, a tem- 
 porary or permanent communication is established between the 
 interior and exterior of the globe, through which various kinds of 
 matter are disengaged from the bosom of the earth. Through the 
 crevices escape gases of different kinds, waters hot or cold, simple 
 
 8. Is there any evidence of the slow and gradual subsidence of land ? 
 
 9. Why is it believed that earthquakes modify the earth's surface ? 
 
 10. What are volcanic phenomena? Give some instances of volcanic 
 phenomena. 
 
VOLCANIC PHENOMENA. 103 
 
 or sulphurous, and loaded with mud, are the most simple transi- 
 tory results. But frequently there are, also, through the upheaved 
 and broken ground, amidst violent detonations, explosions which 
 eject, to a great distance, all the debris of the formation, as 
 happened at Saint-Michel, in the Azores, in 1522, where the 
 debris of two hills covered the whole city of Villa-Franca. It 
 most frequently happens, at the same time, that more or less con- 
 siderable eruptions of incandescent matters take place, consisting 
 of scoria?, pumice, &c., in a melted state, which are either projected 
 to a distance, or run on the slopes, or accumulate on the spot to a 
 greater or less height ; this has occurred in a great many localities. 
 
 Eruption of the island of Saint George. In tho month of May 1808, in 
 the island of Saint George, one of the Azores, the soil in the midst of culti- 
 vated fields after being upheaved opened at many points with a fearful noise. 
 It first formed a vast cavity, or crater, of 100,000 square yards, then a 
 smaller one at the distance of a league, and finally twelve or fifteen little 
 craters on the broken surface. An enormous quantity of scoriae and pumice 
 was projected to a distance, and the ground was covered a yard and a half 
 deep over an extent a league wide and four leagues long. For more than 
 three weeks afterwards currents of melted matter flowed from the principal 
 crater to the sea. 
 
 Monte-Nuovo. Monte-Nuovo, formed in 1538, at the bottom of the bay 
 of Baia, on the coast of Naples, is another example of a similar eruption. 
 Violent earthquakes had continued during two years : on the 27th and 28th 
 September they did not cease either day or night ; the plain found between 
 Lake Averne, Montc-Barbaro and the sea, was then upheaved, and various 
 cracks were evident, Sfc. (Pietro Giacomo di Toledo). Then a great extent 
 of ground was elevated, and suddenly assumed the form of a growing moun- 
 tain ; in the night of the same day this little mountain of earth opened with 
 a great noise, and vomited flames, as well as pumice, stones and cinders 
 (Porzio). The pumice came froifr the upheaval of the soil, which consists 
 of this material throughout Campa'riia ; and the stones and cinders came 
 from the eruption which occurred at the moment : we still see on the south 
 side of the mountain a ridge of scoriae, and on its summit the crater which 
 produced them. The eruption lasted seven days, and the matters projected 
 and ejected partly filled Lake Lucrin. From that time the most perfect 
 tranquillity has prevailed. 
 
 Jorullo. There was something analogous, but under peculiar circum- 
 stances, in what happened in Mechoacan, n<?ar the town of Ario, on the 
 29th September, 1759, after an earthquake of two months duration. In the 
 midst of a plain covered with sugar-cane and indigo, and traversed by two 
 rivulets, there formed in a single night, says M. Humboldt, a gibbosity 
 (bunching up) 160 yards high near the centre, covered by thousands of 
 small smoking cones, in the midst of which were raised up six great hil- 
 locks, arranged in one line (Jig. 1 84), in the direction of the volcanoes of 
 Colima and of Popocatapetl. The highest of these hillocks, called Jorullo, 
 was more than five hundred yards in height above the plain ; from its sides 
 escaped a great quantity of lavas. 
 
 Vesuvius. Something similar must have occurred in Vesuvius, for Strabo 
 describes the mountain so called by the ancients without in any way allud- 
 ing to the remarkable cone which now exists (fig. 185), and which he 
 would not have failed to mention. It is evident this cone did not then 
 exist ; but the crests which rise in semicircles on the north, forming what 
 is new called the sotnma, probably constituted part of a complete circle ; the 
 
104 
 
 VOLCANIC PHENOMENA. 
 
 Fig, 184. Volcan of Jorullo* 
 
 south half, which was much more arched, and separated from the other by 
 a diametrical split, only offers now a trace at the east, and an indication at 
 the west by the pumice tufa of Salvatore. The mountain, which is proba- 
 bly represented in fig. 186, teas, says Strabo, very fertile on its slopes; its 
 
 Fig. 185. View of Vesuvius 
 as it now is. 
 
 Fig. 186. Vesuvius in the lime 
 of Strabo. 
 
 summit was truncated, in a great part ignited, entirely sterile, of a burnt 
 aspect, exhibiting cavities filled with cracks and calcined stones ; from which 
 it may be conjectured that these places were formerly burning craters. All 
 leads to the belief that the cone, which alone bears the name of Vesuvius 
 now, all the products of which differ from the rocks of the sojnma, was not 
 formed till long afterwards, and probably at the time of the famous eruption 
 in the year 79, which cost the life of the Roman naturalist ; it then, with- 
 out doubt, formed a permanent conduit in the midst of the matters which 
 are raised in form of a dome, and which has been enveloped by subsequent 
 gcoriee. This catastrophe seems to have produced but little lava, but a hor- 
 rible upheaval, which precipitated a great part of the mountain into the sea 
 (Pliny the younger), and buried Herculaneum and Pompeii, not under tor- 
 rents of melted matter, as commonly said, but under avalanches of pumice 
 which previously existed on the slope of the mountain, for Vesuvius itself 
 has never produced an atom. If the whole south slope turned towards the 
 sea is now occupied by lava, it is evident that before the formation of the 
 permanent volcan it was covered with pumice tufa, traces of which are still 
 Been at different points, the same as now on the external slope of the somma, 
 and in all Campa'nia. 
 
 11. Definition of a Volcan. In those events, it often happens 
 that the rent, which has given rise to observed effects, fs obstructed 
 or closed at a considerable depth, and tranquillity is entirely re- 
 stored, as 'at Monte-nuevo. Under other circumstances, on the 
 
 11. What is a volcan, or volcano ? 
 
SUBMARINE ERUPTIONS. 105 
 
 contrary, the rent forms a permanent conduit at once, or after seve- 
 ral shocks in the same place. In this case there is sometimes 
 established a continuously active furnace, from which gaseous 
 matter in abundance is disengaged, or from which lava continu- 
 ously boils, and from which there is an incessant projection of 
 scoriae ; this has been the case at Stromboli from the remotest 
 antiquity. At other times the conduit is temporarily obstructed at 
 its upper part ; but the least effort is sufficient to remove the ob- 
 struction, or to produce a new opening in 
 the vicinity, through some fissure which 
 communicates with the principal conduit 
 (Jjg> 187). In all cases, the result is a 
 centre of easy communication between 
 the interior and exterior of the earth, and 
 it is this which is called a volcan or vol- _ Q/S^^^fe 
 
 cano. Fig.\81. Volcanic conduits. 
 
 This facility of communication is probably a preservative against the vi'o- 
 lence of earthquakes ; indeed it has been observed that, from the moment an 
 eruption takes place anywhere, the shocks which had been felt up to that 
 time, become fewer and weaker, and even cease altogether. The earthquake 
 of Caraccas, in 1812, terminated by the eruption of the volean of Saint- 
 Vincent, in the Antilles ; the eruption of Jorvllo, and that -of Montc-Nuevo, 
 terminated the earthquakes which desolated the surrounding countries. On 
 the contrary, when a volcano becomes inactive, it seems to announce earth- 
 quakes ; in 1797, when the volcan of Purace, near Popayan, had ceased to 
 emit flame and smoke, the valley of Quito was agitated by violent shocks. 
 Volcans, therefore, seem to be natural vents, designed by Providence to pre- 
 vent a complete destruction of the globe, and its inevitable rupture into frag- 
 ments, which, launched into space, might there describe new orbits. 
 
 12. Submarine eruptions. It is not only on land that volcanic 
 phenomena occur ; they also take place under the sea, as might 
 be naturally anticipated. In our own times, we have had formed in 
 this manner the island of Julia, in 1831, on the south-west of Sicily ; 
 Bogoslaw, in 1814, in the Aleutian Archipelago ; Sabrina, and 
 another one not named, in 1811, in the Azores, where, previously, 
 at different epochs, others were formed, according to the most 
 authentic histories. The same thing occurred, at different times, 
 around Iceland : and various accounts indicate that in the islands 
 of Sunda, the Philippines and Moluccas, throughout the Pacific, in 
 the Kuriles, Kamtschatka, &c., similar phenomena took place. 
 
 Volcan of Unalaska. One of the most striking examples is furnished by 
 the island, which arose in 1796, about ten leagues from the northern point 
 of Unalaska, one of the Aleutian islands. At first a column of smoke rose 
 above the surface of the sea ; then a black point appeared, the smmit of 
 which launched forth sheets of fire and stones with violence. This pheno- 
 menon continued for several months, during which the island grew succes- 
 sively in extent and height; later, srnoke only issued, which ceased altoge. 
 ther four years afterwards. Still the island continued to enlarge, and to rise 
 
 12. Do volcanic eruptions take place on land exclusively ? 
 
106 PHENOMENA OF SUBMARINE ERUPTIONS. 
 
 without any apparent ejection ; and, in 1806, it formed a cone which might 
 be seen from Unalaska, and upon it were four other smaller ones, on the 
 north-west side. 
 
 Santorin. The Mediterranean also furnishes a fine example of submarine 
 eruptions, in the midst of the space comprised between the islands of San- 
 torin, Teresia and Aspronisi (Jig. 193), which, according to the ancients, 
 appeared above the water several centuries before the Christian era, in con- 
 sequence of violent earthquakes. In this circuit, Hiera arose first, 186 years 
 before our era, which subsequently grew by little islets rising on its borders 
 in the years 19, 726, 1427 ; then, in the same way, Micra-Kamcni, in 1573, 
 and Nea-Kameni, in 1707, were formed ; and successively growing in 1709, 
 1711, 1712, &,c. No crater was formed in either of these islands, and we 
 only have there the appearance of volcanic matter in form of a dome, which 
 seems to have covered the orifice through which it escaped.- There was no 
 volcan there, according to the terms of our definition, but a tendency to form 
 one at some future time. The islands of Milo, Argentiera, Polino, Polican- 
 dro, Poros, &c., are formed of the same materials, and probably had the same 
 origin. 
 
 13. Wlmt passes in these phenomena. These submarine phe- 
 nomena are announced by incandescent matters ejected above 
 water ; by scoria? and pumice, which float on the surface ; by burn- 
 ing rocks, which appear in the midst of waves of vapour, and by 
 the boiling of the sea, the temperature of which becomes very 
 niuch increased. All these things occurred in our own times, at 
 Julia, at Sabrina, &c., and are such as authors mention in detail, in 
 all their accounts. Father Goree has given us a history of the 
 upheaval of Nea-Kameni, of Santorin, in 1707 ; and all the cir- 
 cumstances he relates agree with what Strabo, Pliny, Plutarch and 
 Justin tell us of the appearance of Hiera, in the midst of flames, 
 and a violent ebullition of the sea. 
 
 But the circumstances we have just spoken of are not always all present 
 at the same time. Sometimes no solid rock appears above water; this 
 was the case at Kamtschatka, in 1737, where jets of vapour, great ebul- 
 lition of the sea, and pumice-stones floating on the surface, were all that 
 was perceived ; but when the spot could be approached, there was found a 
 chaiu of submarine mountains, where there had been previously a depth of 
 more than a hundred fathoms. In certain cases there is not even a jet of 
 vapour, and the phenomenon is manifested by the heat of the water only ; 
 this happened in 1820, at the island of Banda, among the Moluccas, where 
 the bay, which was upwards of fifty fathoms deep, was filled by the tranquil 
 elevation of compact basa'ltic matter, probably pre-existing, which formed 
 an elevated promontory composed of large blocks piled one on the other ; 
 and its appearance was manifested by the heat of the water only. It also 
 seems, that after eruptions, there is often a peaceful and slow upheaval, as 
 in the island formed before Unalaska, and at Santorin, according to the 
 observations of M. Virlet. Indeed, between Micra-Kameni and the port of 
 Phira, where there is an abrupt submarine mountain, there was, at the be- 
 ginning of the present century, fifteen fathoms of water above the highest 
 part ; but there were only four fathoms in 1830, and little more than two in 
 1834. It is presumed a new island, that is, the summit of a new cone, 
 will appear in the gulf, and the appearance will, probably, be accompanied 
 by such phenomena as we mention. 
 
 13. What phenomena occur in submarine eruptions ? 
 
VOLCANIC PHENOMENA. CRATERS. 107 
 
 Let us add that islands which rise to the surface of seas do not always 
 remain. Many of them disappear after a longer or shorter period, either 
 by being washed down by the waves, as is supposed to have been the case 
 with the island of Julia, or by their mass sinking into an abyss formed be- 
 neath them ; the last circumstance doubtlessly happened to an island which 
 was elevated in 1719, near Saint-Michael (Azores), and disappeared in 
 1723, leaving in its place a depth of seventy fathoms. In the same region 
 there was an island in 1 633, where there is now a bottomless abyss. 
 
 14. Crater of upheaval, or elevation. The first effect of an 
 eruption is to burst, by its violence, the crust of the earth in the 
 direction which matters pent up in the interior have taken to 
 escape. The ground, no matter of what nature, is at first raised 
 to a more or less considerable extent, or arched like a bell, and 
 often cracked in every direction ; at once, the explosion occurring, 
 as if by the action of a formidable powder-blast, an opening is 
 made in the form of a funnel, through which often escape gaseous 
 and other matters which caused the event. It is to these initiatory 
 openings, which may be made anywhere, to which the name of 
 crater of elevation has been given, from the necessity of distin- 
 guishing them from all that may subsequently occur in the series 
 of volcanic phenomena. The hillock itself which is produced on 
 the soil, by the first effect, is called the cone of elevation, to distin- 
 guish it from analogous hillocks which are often formed also by 
 the accumulation of incoherent materials ejected from the volcano. 
 
 15. Character of these openings. What characterizes craters 
 of elevation, and enables us to recognise them in places where 
 there is no account of an eruption, is, the disposition or arrange- 
 ment of the upheaved strata, being very different from what is 
 everywhere else observed. These beds are here found inclined all 
 
 round the axis of the cone, as in the 
 section (fig. 188), rising more and 
 more from the base to the summit, 
 and presenting their abrupt escarp- 
 
 ment " T 1 * the interior of the 
 
 cavity. Monte-Nuovo is an exam- 
 ple in miniature : the mountain was formed by elevation, hollowed at 
 its summit by ejecting gases and incandescent matters ; and the 
 cavity, which can be examined now, has around it, at an inclination 
 of thirty degrees, strata of different formations, which in all the 
 rest of Campa'nia are horizontal. The semicircle of the somma 
 presents the same characters in the inclined tables of amphige'nic 
 porphyries, and analogous circumstances exist in many other 
 localities. 
 
 16. Another character, not less important, and especially useful 
 when the upheaved matters are not divided into beds, is furnished 
 
 14. What is a crater of elevation ? What is a cone of elevation ? 
 
 15. How are craters of elevation characterized ? 
 
108 
 
 VOLCANIC PHENOMENA. CRATERS. 
 
 us in great craters of elevation by the crevices or cracks which 
 extend from the margin of the escarpment to the external base of 
 the mountain, forming what are named barancos in the Canary 
 islands, where they are so remarkable. One of these barancos 
 (or ravines) much deeper than the others, extends from the foot of 
 the mountain to the bottom of the crater, as is shown in the follow- 
 ing view (Jig. 189). This last character is seen almost always in 
 
 Fig. 189. View of the Island of Palma. 
 
 the different localities produced by similar events, as well as in 
 most islands which have been upheaved in our times in the midst 
 of the ocean ; frequently there are many valleys of the same kind. 
 
 Remarks on the formation of craters. We have mentioned explosion as 
 determining, definitely, the formation of the crate'riform cavity at the sum- 
 mit of the upheaved mass ; however, it is not probable that this circum- 
 stance, which is applicable to Monte-Nuovo, the island of St. George, &c., 
 is constantly seen in all cases; it seems to be even totally inadmissible in 
 certain craters of vast extent known to exist in a number of places. But 
 this explosion is not even necessary. In fact it is easy to conceive that 
 
 after a fracture, as in fig. 190, 
 which is a correlative result of ele- 
 vation, it may happen that all the 
 erect, eolumri-like masses, and all 
 the elongated points between the 
 rents, might be tumbled down at the 
 same moment, or by a subsequent 
 action. Hence results an open cavi- 
 ty (fig. 191), the margin of which 
 is formed by all the debris, and the 
 depth is in proportion to the sum of 
 the voids or spaces formed by the 
 fractures. On the other hand, it is 
 clear that elevation is produced by 
 some matter, liquid or gaseous, 
 which pushes the crust of the earth 
 
 and forces it to swell upwards ; now, 
 if it happen that this matter should 
 find exit at some other point, or re- 
 tire again into the bowels of the 
 earth, the upheaved part being left 
 without support may sink into the 
 abyss left beneath it, and conse- 
 quently cause an immense vacuity 
 in the midst of the gibbosity or 
 Fig. 191. hillock, then merely forming a mass 
 
 16. How are craters of elevation distinguished when the upheaved mat- 
 ters are not divided into beds ? 
 
VOLCANIC PHENOMENA. CRATERS. 
 
 109 
 
 hollow in the centre, and cracked on the margin. This must have taken 
 place in many cases, and notably in the mass of Etna, (fig. 192), the east- 
 ern slope of which presents a vast excavation, called Val del Bove, which is 
 bounded by high ridges, cracked at various points. 
 
 Lava of 1822. - 
 
 Terminal cone. 
 ValdeBove. 
 
 LavaoflGGO. 
 
 C.VTANEA. 
 
 Islands of Cyclops. 
 
 
 Fig. 192. Plan of Etna and its environs, according to the relievo of 
 M. Elie de Beaumont. 
 
 This comment need not be regarded as a simple theoretic speculation ; 
 there are many examples of similar excavations, independent of the effects 
 produced by earthquakes. At the summit of Mount Etna there is one of 
 1300 feet in depth, which dates from 1832, and many others which were 
 produced at the end of the last or beginning of the present century. Fre- 
 quently lakes are formed on a sudden, sometimes of boiling water, by the 
 sinking of the land consequent on volcanic eruptions, as in 1835, near the 
 ancient Cesarea in Cappadocia ; in 1820, in St. Michael's (Azores), &c. It 
 has also happened that high volcanic mountains have at once sunk, their 
 place being at once filled by deep lakes, as the volcano of Papadayann in 
 Java, in 1772, which carried away with it forty villages built on its sides : 
 as also, in 1638, the peak of the Moluccas, which could be perceived twelve 
 leagues at sea. We know that the summit of Carguarai'zo which rivalled 
 Chimborazo in height, crumbled in 1698, and the same occurred to Capac- 
 TJrcu, also situated on the plane of Quito, a short time before the arrival of 
 the Spaniards in America. Many other facts of a similar kind could be 
 adduced in support of the theory advanced. 
 
 17. Effects subsequent to elevation. The crate'riform cavities 
 we have spoken of sometimes remain tKe same as when first pro- 
 duced ; often, however, various volcanic phenomena subsequently 
 occur at different times and in various ways. In this manner it 
 was that the cone of Vesuvius (Jig. 185) was formed in 79 in the 
 ancient crater of the Somina (p. 104) ; that the peak of Teneriffe 
 is found in a circle, the vertical walls of which rise from 600 to 
 1200 feet; that the volcan of Taal, in Luzon, one of the Philip- 
 pine islarids, is in the centre of a basin filled with water, and sur- 
 
 17. Do craters of elevation always remain the same as when first pro- 
 duced ? Give some examples of the secondary effects of eruptions. 
 10 
 
110 
 
 VOLCANIC ISLANDS. 
 
 rounded by elevated rocks, having a single opening only for 
 entrance &c. 
 
 Islands which have been elevated in the midst of the sea frequently 
 exhibit phenomena of the same kind. Thus the islands of Santorin, The- 
 resia, Aspronisi, (Jig. 193), which were elevated long before the Christian 
 era, present the appearance of a vast crater of elevation : their slopes are 
 gentle (Jig. 193) externally, but abrupt, on the contrary, towards the centre 
 
 Theresia. 
 
 Santorin. 
 
 Fig. 193. Section of Santorin and adjacent islands. 
 
 of the circle of which they form the margin. The ground is composed of 
 various strata, inclined outwardly, among which are limestone and argilla'- 
 ceous schist. In the middle of the circle, the depth of which is considera- 
 ble on the borders, all the subsequent volcanic phenomena were produced, 
 and here the three summits of cones successively appeared, which consti- 
 tute three modern islands, and are still preparing new eruptions. 
 
 Something similar is seen in the Gulf of Bengal, on the Island of Barren, 
 discovered in 1787. It is a vast circle (Jig. 194) formed of high moun- 
 tains, into which the sea penetrates by a single opening, and has a volcan 
 in the centre which was in full activity at the time of the discovery. 
 
 Fig. 194. View of the Island of Barren in the Gulf of Bengal 
 
 18. 'Similarity of configuration in Volcanic Islands. Different 
 volcanic islands which have been formed under our eyes, as it were, 
 in the midst of the ocean, are entirely analogous to those we have 
 mentioned. The island of Sabrina, at the moment of its appear- 
 ance, presented a crater which opened to the south, (jigs. 195, 196), 
 and terminated by an opening, through which issued a current of 
 boiling water: according to the accounts, the island of Julia must 
 have been somewhat analogous ; and the history given by Captain 
 Thayer, reported by Poeppig, shows such to have been the case. 
 On the 6th September, 1835, to the north of New Zealand, this 
 navigator almost witnessed a submarine eruption, which presented 
 
 18. How do volcanic islands differ from each other in form ? 
 
VOLCANIC ISLANDS. 
 
 Ill 
 
 Fig. 195. Fig. 196. 
 
 Appearance and form of certain volcanic islands. 
 
 an annular rock, almost on a level with the surface of the sea, in 
 the midst of which was a lagune having a single outlet, and in 
 which the water was burning. Now, these islands appear to be 
 nothing more than points of domes upheaved, like those in the 
 gulf of Santorin, either instantaneously or slowly, and having the 
 summit broken, like Monte-Nuovo. These are true craters of 
 elevation or of explosion, as we would call them ; and as such 
 they may consist of solid rocks, or of various tufas, or even of 
 scoriae accumulated on their borders. The archipelago of the 
 Azores, which have so often witnessed rising from the sea similar 
 islands, which time has destroyed, presents us one which seems to 
 have escaped destruction, to exhibit to us how all those were 
 formed which have disappeared. This is the rock of Porto de 
 Ilhco, which presents a vast circle, into which vessels enter for 
 shelter; its sides rise 400 feet and are composed of volcanic tufa. 
 
 19. These phenomena explain to us the origin of a great many 
 islands found in the ocean (Jig- 197), both by the analogy of their 
 form to those we have named, and their nature. Some are in the 
 form of a horse-shoe, having a more -, ^^ 
 
 or less expanded opening, which //- O"S 
 gives access to the middle of the 
 deep basin they enclose, and in the 
 centre of which isolated volcanic 
 hillocks are occasionally found. Fig. 197. Disposition of certain 
 Others are entirely circular, having islands in the South Seas 
 some of the points of the circle more or less broken, or groups of 
 small islands arranged in a circle, which are more or less promi- 
 nent above the water. 
 
 20. Different periods of the formation of a volcan. We may 
 often distinguish in the mass of a volcanic mountain, several dif- 
 
 o 
 
 19. How do volcanic phenomena explain the origin of certain islands ? 
 

 112 VOLCANIC PHENOMENA. 
 
 ferent parts, each of which corresponds to a particular mode of 
 formation. The first gibbosity or hill is, in general, the effect of 
 elevation of the pre-existing soil, which may be of any kind or 
 nature. Afterwards, sooner or later a fissure is formed, which 
 produces either a crater of elevation or a dome of pasty matter, 
 as at Jorullo, clearly detached from the first hillock; and, as a last 
 result, in the midst of one or the other a permanent chimney is 
 formed. Often the formation of the terminal cone then commences, 
 by the scoriaceous matters raised by the melted lava filling the 
 primitive conduit, which overflows the margin of the aperture, or 
 it is ejected into the air, from which it falls again around the centre 
 of eruption, accumulating in cones with a maximum slope of from 
 30 to 35. These loose scoriae melt on the side towards the inte- 
 rior of the chimney, which they narrow more and more by the suc- 
 cessive cornice-like projections they form, and in this way conceal 
 the true diameter of the crater. 
 
 21. It is rare that these three kinds of formations are all found 
 in the same volcano ; but we always find the gibbosity produced by 
 elevation, and one or the other of the secondary domes. At Tene- 
 riffe there is a broken dome Avhich was upheaved in the middle of 
 a crater of elevation. At Vesuvius, from the constant solidity of 
 the base, and other circumstances, we may infer the existence of a 
 central nucleus, produced in the same way as a dome, in the year 
 79, afterwards enveloped in loose materials, and bearing on its 
 summit a true cone of scoriae. At Etna (fig. 198) we clearly 
 
 Fig. 198. View and profile of Etna, and the surrounding country, r- 
 
 distinguish the primitive hill or gibbosity, showing sheets or 
 coats of ancient upheaved lavas, on the middle of the slightly- 
 arched surface, which all this part of the island presents ; it is 
 terminated by an almost level surface, the Piano del Lago, in 
 the midst of which rises the terminal cone of scoriae, regularly cir- 
 cumscribed on all sides, and clearly separated from the base on 
 which it was formed. On the slopes are small cones of eruption, 
 formed here and there, at different times, which have since contri- 
 buted to the swelling up of the whole of the surrounding land. 
 
 22. It is clear, that the cones of scoriae constructed in the man- 
 ner just mentioned, at the bottom of volcanic gulfs, cannot be very 
 solid ; they often change their form at every eruption. Sometimes 
 the edifice rises more and more ; sometimes, on the contrary, it 
 
 20. Are volcans always characterized by the .same kind of formations ? 
 
 21. Do we always find in one volcano all the kinds of formation ? What 
 one is always found ? 
 
 22. What are the characters of cones of scorice found at the bottom of 
 volcanic gulfs ? 
 
INTERIOR OF CRATERS. 
 
 crumbles into more or less considerable shreds, and hence cones 
 are deeply broken in all manners of shape. Sometimes the whole 
 mass is swallowed at once in the abyss it covered, and is recon- 
 structed by subsequent eruptions. This took place in the terminal 
 cone of Etna, which has several times disappeared entirely Cleaving 
 an immense aperture, without parapet, in the midst of a little plain 
 which crowned the original gibbosity or hill. At Vesuvius only 
 the upper part of the cone has ever been modified. 
 
 23. Interior of craters. Contrary to the expectation of all those 
 who visit volcanoes, the interior of craters seldom possesses much 
 that is worthy of observation. After great eruptions, during which 
 they cannot be approached, these cavities (which are of conical 
 form, and have a more or less extensive diameter at the top, with a 
 bottom apparently formed of a sheet of consolidated lava, which 
 covers the principal chimney) ordinarily present for observation 
 merely jets of sulphurous vapours, escaping here and there from 
 fissures in the soil, from interstices in blocks of crumbled scoriae, or 
 a greater or less number of small cones raised up in different 
 places. Occasionally we see one or more gulfs, sometimes filled 
 with vapours which escape continually, and sometimes revealing 
 the incandescent lava in the depth ; sometimes silent and dark, 
 inspiring with terror, but without possessing the least interest for 
 observation. In long intervals of crises, traces of volcanic action 
 often entirely disappear ; in certain instances even the sides of 
 the crater become covered by vegetation, as is related of Vesuvius 
 before the eruption of 1631. 
 
 24. There are, however, some observations worthy attention. 
 The crater of Stromboli, which has been in continuous activity from 
 the most ancient times, still presents phenomena identical with 
 those recorded by Spallanzani, in 1788. It is constantly full of 
 melted lava, which alternately rises and sinks in the cavity. Having 
 reached to twenty-five or thirty feet of the edge, this lava swells, 
 is covered with large vesicles or blisters, which speedily burst with 
 a noise, permitting the escape of an enormous quantity of gas, and 
 projecting scoriaceous matters on all sides. It immediately sinks, 
 after an explosion, then rises again, to produce the same effects, 
 which are in this way repeated at regular intervals of some mi- 
 nutes. 
 
 25. If the lava of Stromboli were less fluid, it is conceived, that 
 having reached to its highest point, it would there stop, assume an 
 arched form, and become consolidated into a more or less elevated 
 cone ; and then, if an explosion occurred at a certain instant, a new 
 conical crater would be found in the middle of the old one. This 
 
 23. What is found in the interior of craters ? 
 
 24. What is remarked of the crater of Stromboli ? 
 
 25. What would probably be observed, if the lava of Stromboli were less 
 fluid than it is ? 
 
 10* 
 
114 
 
 INTERIOR OF CRATERS. 
 
 explains what frequently takes place in volcanoes, and, for exam- 
 ple, at Vesuvius (fig. 199), where domes have been raised which 
 remained for a long time, and were subsequently broken, giving 
 passage to lavas, and finally sank into abysses left beneath them. 
 Certain, craters, having a widely extended bottom, often contain 
 hills of considerable height, which have had an origin such as we 
 have described ; either the lava is arrested at a certain height, in 
 
 Fig. 199. Adventitious Crater > in the middle of Vesuvius, in 1829. 
 
 form of a cap, or swelled up at different points, or elevations took 
 place in different matters which had filled the cavity. 
 
 26. Sometimes, in place of lava, there is found at the bottom of 
 craters boiling sulphur, as was seen at Vulcano, and, on a larger 
 scale, at the volcan of Taal, in the island of Luzon, and at that of 
 Azufral, to the north of Quito, in the Andes ; hills, and even 
 domes of sulphur, are also mentioned, as M. Boussingault observed 
 at the volcan of Pasto. 
 
 A crater now often mentioned by voyagers is that of Kirauea, on the island 
 of Hawaii, one of the Sandwich group. This vast cavity is three and a 
 half miles long and two and a half wide, and over a thousand feet deep : 
 Captain Wilkes, in his narrative of the United States Exploring Expedition, 
 states that " the city of New York might be placed within it, and when at 
 its bottom would be hardly noticed. A black ledge surrounds it at the depth 
 of 660 feet, and thence to the bottom is 384 feet. The bottom looks in the 
 
 26. Is anything found at the bottom of craters besides lava ? 
 
VOLCANIC PHENOMENA. SOLFATARAS. 115 
 
 daytime like a heap of smouldering ruins. The descent to the ledge appears 
 to the sight a short and easy task, but it takes an hour to accomplish. 
 
 "All the usual ideas of volcanic craters are dissipated upon seeing this. 
 Tiierc is no elevated cone, no igneous matter or rocks ejected beyond the 
 rim. The banks appear as if built of massive blocks, which are in places 
 clothed with ferns, nourished by the issuing vapours. 
 
 "What is wonderful in the day, becomes ten times more so at night. 
 The immense pool of cherry-red liquid lava, in a state of violent ebullition, 
 illuminates the whole expanse, and flows in all directions like water, while 
 an illuminated cloud hangs over it like a vast canopy." 
 
 27. Solfata'ras. There are a great many craters which for a 
 long time have not given exit to any lava, and are reduced to dis- 
 engaging, in greater or less abundance, sulphurous gas, which 
 escapes by a multitude of fissures in the soil, and often accompa- 
 nied by aqueous vapour. Hence the name of Solfata'ra has been 
 given to those places where these phenomena are more or less 
 developed. Thefe are some craters which seem to have been 
 always in this state. Such, for example, is the Solfata'ra of Pouz- 
 zouli, in the kingdom of Naples, which is a vast crater of eleva- 
 tion, at the bottom of which are found broken volcanic rocks, daily 
 decomposed by the vapours. This solfata'ra is of the highest anti- 
 quity, and appears never to have presented other phenomena than 
 those now observed. When in repose, volcanic craters become 
 more or less active solfata'ras. 
 
 28. It is not uncommon to find one or more lakes, frequently of 
 great depth, at the bottom of craters and solfata'ras. The waters 
 they contain are sometimes quite pure, but they are often .charged 
 with various salts, or sulphurous or sulphuric acid, as was seen 
 in the volcan of Teschem, in the island of Java, prior to 1817, 
 the year when this mountain was entirely destroyed by the action 
 of gas. 
 
 29. Commencement of eruptions. Continuous emissions of gas 
 or scoriaceous matter from certain volcans, must not be confounded 
 with eruptions, which are sudden events, fortunately transitory, 
 often bringing desolation over an entire country. When an erup- 
 tion is about to take place it is ordinarily preceded by earthquakes, 
 after which it suddenly occurs with more or less noise. If a volcan 
 already exist in the country, an eruption begins by pouring out 
 abundant fumes, composed of various gases and aqueous vapour, 
 then pulverulent matter called volcanic ashes, the quantity of which 
 is sometimes immense ; then follow directly, when they do not 
 appear from the beginning, fragments of red-hot porous stones, 
 called rapilli or lapilli and pouzzolani, more or less considerable 
 blocks of solid matter, which are sometimes ejected to great dis- 
 
 27. What are Solfata'ras ? 
 
 28. What is the character of the water of lakes found in craters ? 
 
 29. How is the commencement of eruptions characterized I What are 
 volcanic ashes ? What is rapilli ? What are volcanic bombs ? What is 
 tu'fa ? 
 
116 VOLCANIC PHENOMENA. ERUPTIONS. 
 
 tances ; and lastly, portions of melted matter torn from the lava 
 filling the crater, and becoming rounded by their motion through 
 the air, form what are called volcanic bombs. From all this we 
 have, amidst violent detonations, immense bundles or masses of 
 various matters projected to great heights, lighted by reflection from 
 the melted lava, part of which fall at greater or less distances, ac- 
 cording to their weight and the force with which they are impelled. 
 Ashes, rapilli, or pomice then produce in the vicinity of the volcan, 
 sometimes even at a distance, considerable deposits, which becoming 
 solid by their weight and by water, form what is termed volcanic 
 tufa,pumice tufa, and various conglomerates. 
 
 The vapours and ashes ejected from volcanoes sometimes form enormous 
 clouds, frequently dense enough to intercept the light of day, and shroud 
 the whole neighbourhood in darkness. These clouds, driven by the wind, 
 are sometimes carried to the distance of twenty, fifty, and even two hun- 
 dred leagues. This happened in 1812, when the ashes of Saint Vincent, in 
 the Antilles, were carried to Barbadoes, and so darkened the air that persons 
 could not see their way. The ashes of Vesuvius were carried in 1794 to 
 the end of Calabria; and it was found even in Procopus, that during the 
 eruption of 452 they were conveyed as far as Constantinople. 
 
 What occurs at the bottom of seas during eruptions is not seen ; but it is 
 clear that the ejection of earthy matters, rapilli, and pumice, are not less 
 abundant, because we find at these times on the surface enormous quanti- 
 ties of them, and in land upheaved, there are seen distinctly deposits of 
 volcanic tufa, pumice tufa, and conglomerates, precisely like those formed 
 on land. 
 
 30. Appearance of melted matters. The phenomena mentioned 
 are sometimes the only effects of an eruption ; but most generally 
 they are only the precursors or sequents of the expulsion of melted 
 matter, which soon appears under different forms. Sometimes 
 these matters, most frequently in mass, rise in cones or domes 
 above the very orifice from which they issued, sometimes entire, 
 sometimes vertically perforated in the centre, sometimes suscep- 
 tible of being pushed further out. This happened at Jorullo, and 
 again and again in the gulf of Santorin, and the same must occur 
 in a great many other localities. 
 
 31. Under other circumstances, the crater first formed at the 
 summit of a volcan is completely filled with melted matters ; these 
 soon break a passage at a greater or less depth, pouring out tor- 
 rents, which furrow the side of the mountain, and run to the 
 plain, where they spread more or less. 
 
 32. Form of currents. If fissures or cracks of eruption be 
 formed at the foot of a volcano in a flat country, the lava escaping 
 from it at once forms broad horizontal sheets in the middle of the 
 plain. This occurred in Iceland in 1783; crevasses formed in the 
 plain at the foot of Skaptar-Jokul, a high volcanic mountain of the 
 
 30. What is the form of melted matters ejected from volcanoes ? 
 
 31. How are lava-currents formed? 
 
 32. What is the form of lava-currents ? 
 
VOLCANIC PHENOMENA. LAVA-CURRENTS. 117 
 
 country, and an immense volume of melted matter escaped from 
 them. This immediately spread over the soil, covering eighty 
 square leagues, filling up all depressions, and forming a vast lake 
 of fire of considerable depth. 
 
 33. But this is not always the case ; the current often forms on 
 more or less inclined slopes, and the lava forms true currents on 
 their surface, of greater or less length, a part of which adheres to 
 the land in consequence of cooling, and in evidence of its passage. 
 After its exit from the bosom of the earth, the melted matter soon 
 cools an the outside, solidifies, wrinkling and cracking in every 
 direction, and thus acquires a crust, ordinarily porous, the thickness 
 of which becomes more or less considerable. This crust prevents 
 the liquid or paste it envelopes from spreading, and confines the 
 current to a certain thickness ; also, from its slight faculty of con- 
 ducting heat it prevents the interior lava from cooling, which, from 
 this cause, goes on very slowly. Lavas have in fact remained 
 liquid or pasty, and preserved a high temperature for a very con- 
 siderable time ; some are cited as still running on very gentle 
 slopes, ten years after their ejection, and others which gave off 
 vapour twenty-six years after their exit from the bosorn of the earth. 
 
 34. If after the external cooling the volcanic spring continues 
 to furnish melted lava, the current takes place in a kind of con- 
 solidated sack which is formed ; a sack which then strives, as it 
 were, in all directions, is broken and mended successively ; this 
 causes the twisting and various irregularities in the current of 
 lava. When the source is stopped, the matter which escaped from 
 it does not continue to flow the less in the sack enclosing it, but the 
 latter successively flattens, and the middle is effaced, leaving a 
 more or less elevated roll or ridge on the margins. This is first 
 seen at the upper part of the current, then successively to a point 
 where the liquid matter, becoming 
 
 more and more viscid, has not suffi- 
 cient force to drag after it the solid 
 parts formed, to break or push them 
 forwards. The lava then stops at 
 the bottom of the sack, terminating fig. 2QQ. Lava-current arrested 
 in a club-like mass (Jig. 200). The ^ on a sl P e - 
 
 form, direction, and extent of these lava-currents vary according 
 to circumstances, such as the degree of inclination of the mountain 
 sides, and the nature of the lava itself. Some volcanic products 
 are so pasty they cannot run, but remain over the aperture, as 
 occurs with certain trachytes, which then form more or less elevated 
 domes. Others, such as various obsidians, which seem to cool 
 and harden quickly, are sometimes arrested in form of great tears, 
 
 33. Do lava currents cool rapidly under all circumstances ? 
 
 34. Is the form, direction, and extent of lava-currents always the same ? 
 
118 VEINS OF LAVA, OR DYKES. 
 
 even on steep slopes, as at Teneriffe. On the contrary, stony lavas 
 which cool slowly and long remain fluid, are not arrested except 
 on a horizontal plain. 
 
 35. Various characters of the same lava. From what has been 
 stated, it is certain that lavas cannot accumulate to a great thick- 
 ness, or spread in sheets, except on a horizontal plain. The struc- 
 ture of lava depends, in a degree, on its external arrangement. The 
 vein, which is behind -the current, on a veiy steep slope, is, in parts, 
 thin, scoriaceous, corded, and always very porous. On less steep 
 slopes, the surface of pieces is more united, the pores are smaller ; 
 on descents, at an angle of from three to five degrees, the dislocated 
 parts are in plates of greater or less thickness, the structure of 
 which presents a certain uniformity, and the centre is sometimes a 
 little more compact, if the thickness is sufficient. In great flows, 
 causing great accumulations on plains, where the depressions are 
 filled up, all the inferior part becomes a compact, and, more or 
 less, crystalline mass, which is porphyritic, because then it cools 
 slowly and tranquilly ; in this case it is frequently divided, through 
 its whole height, into columnar masses, generally normal on the 
 cooling surfaces, and porous at the upper part only ; this is seen 
 at Vesuvius and Etna, where the lava is very thick, and at Iceland 
 in the immense deposit formed by the eruption of 1783. 
 
 36. Veins of Lava, or Dykes. It frequently happens, that in 
 volcanic eruptions there is formed, on the sides of the mountain, 
 crevices of greater or less breadth, through which the lava comes 
 to the surface of the soil. These cracks are remarked for a long 
 time after their formation, either from remaining partly open, or 
 from the rapilli with which they are filled, leaving a kind of ditch, 
 which may be readily followed. They may be also recognised by 
 the partial and crate'riform excavations of these debris, which all 
 have the same line of direction ; sometimes they are distinguished 
 by rolls of scoria on the edges, which escaped while the lava was 
 boiling in the interior; they also exhibit conduits of lava, which 
 unite to each other the different cones of eruption formed on their 
 line of direction. It cannot be doubted that these cracks remain 
 partly filled with the lava to which they gave passage, giving rise 
 to veins, or dykes. Sometimes the lava flows above the crack or 
 fissure, forming sheets on the surface. Sometimes a coat or bed 
 of lava is found in evident communication with a dyke, which, 
 after having passed up through all the lower deposits, stops in- the 
 middle of it (Jig. 201) ; and it is not rare to find several beds of 
 lava lying one above the other, each one corresponding with a par- 
 ticular dyke (fig. 202), to which, no doubt, it owes its origin ; the 
 
 35. Are the characters of lava always the same ? 
 
 36. What are dykes ? Are all dykes precisely the same in character ? 
 
GASEOUS VOLCANIC PRODUCTS. 119 
 
 most recent of these dykes or veins being the one which has passed 
 up through all the inferior beds or tables, to form the upper one. 
 
 Fig. 201. Fig. 202. 
 
 Sheets, or tables of Lava, with their corresponding Dykes. 
 
 37. The matter that constitutes dykes is rarely porous, except 
 sometimes on the sides towards the rock encasing it ; it is fre- 
 quently even of a finer grain than the table or bed in which the 
 dyke terminates ; its mass is sometimes divided into prisms per- 
 pendicular to the sides of the fissure, which were the cooling sur- 
 faces. This matter generally re- 
 
 sists atmospheric influences, and 
 it frequently happens that the 
 surrounding rock being degraded, 
 carried away by external agents, f 
 the dyke remains projecting on 
 
 the side of the escarpment (jig- 
 
 203), or even rising out of the Fig-. 203. Dyke brought into view by 
 earth like a wall. destruction of surrounding rocks. 
 
 38. Gaseous volcanic products. Volcanic phenomena are ac- 
 companied by the production of great quantities of various gases, 
 some permanent, others condensable or soluble. These products 
 consist for the most part of watery vapour ; but they are found to 
 contain also various acids, and other matters sublimated from the 
 volcano. Most of these gases are fatal when breathed. 
 
 Gases, always at a high temperature and mixed with the vapour of water, 
 act powerfully on the solid surrounding- matters ; they disaggregate and 
 decompose them in all ways, reduce them to powder, to mud, and form new 
 compounds of every kind. This happens in all solfata'ras, where it is often 
 necessary to be cautioned against falling into masses of muddy matter, 
 which is sometimes very hot. But nothing is comparable in this respect to 
 the volcans of Java; the acid and aqueous vapours which are there in great 
 abundance, destroy the rocks and form a paste of them, which speedily 
 becomes incapable of resisting the explosive action of the interior. These 
 fearful eruptions take place, not of lava as in ordinary volcanoes, but of 
 enormous masses of boiling water, charged with sulphuric acid and thick 
 mud, which destroy everything in their way, and cover the whole country 
 with a sulphurous slime the matter of which is called buah. This happened 
 in 1822, on the eruption of Gallung-Gung, which, with earthquakes and 
 horrible noises, was considerably sunk, truncated at the summit, and entirely 
 overturned. Torrents of hot sulphurous water and mud issued from rents 
 
 37. What is the character of the matter constituting dykes ? By what 
 means are dykes sometimes naturally brought into view ? 
 
 38. What are the characters of the gaseous products of volcanoes? How 
 do gases affect surrounding solids ? Do volcanoes ever eject mud 1 In 
 what condition is lava when gases are disengaged from it ? 
 
120 SOLID VOLCANIC PRODUCTS. 
 
 in the side of the mountain ; and many inhabitants were swept away in the 
 waters, or buried under deposits of mud, during the 8th and 12th days of 
 October. 
 
 Muddy eruptions of Quito. The volcans of Peru, which like those of Java 
 have rarely produced lavas, vomit from their sides torrents of mud called 
 rwoya, sometimes sulphurous like the luah of Java, at others carboni'ferous. 
 This happened in 1698, when the volcan of Carguarai'zo crumbled, covering 
 more than 2500 square miles with mud ; and in 1797, when the village Pel- 
 lile'o, near Rio-Bamba, was buried under a mass of black mud, &c. What 
 especially characterizes the eruptions in Peru, and makes them very strange, 
 is that the muddy waters which spring from the bosom of the earth, are 
 filled witli small fishes, species of which live in the neighbouring lakes; and 
 the quantity of them has been sometimes so great as to excite epidemic dis- 
 eases by their putrefaction. 
 
 Gases disengaged from Lavas. It can be readily conceived that gases 
 and matters of various kinds may be disengaged from the bowels of the 
 earth, through fissures communicating with its surface ; but what is most 
 remarkable, they are also disengaged from lavas, although on leaving the 
 volcano they have no properties in common. As long as the lava is fluid 
 and at a high temperature nothing escapes from it, but the moment it begins 
 to harden, and consequently to cool, gases are disengaged in more or less 
 quantity. Streams, matters which filled the lowest levels, then constantly 
 emit the vapour of water, hydrochloric acid, sal ammoniac, which are de- 
 posited on the snrface, to say nothing of realgar, iron, &c., which are some- 
 times sublimed in the fissures or cracks. Consequently the lava itself must 
 contain these matters, which remain engaged in it, we know not how, while 
 the mass is fluid or pasty, and which are disengaged just in proportion as 
 it solidifies and cools, and in a manner which leaves no after-trace. It is 
 supposed that all these matters give to porous lavas, the power of preserving 
 their fluidity for a much longer time than similar substances artificially 
 prepared. 
 
 39. Solid products of Volcanoes. All the solid substances which 
 volcanoes produce in great abundance, belong to the group of si'li- 
 cates, generally anhy'drous si'licates, and particularly to that divi- 
 sion of those confounded under the name of feldspar. These are 
 generally compound rocks, and substances more or less mixed, the 
 principal base of which it is difficult to separate, and therefore 
 they cannot be accurately classified : we are forced to resort to 
 artificial divisions. 
 
 1st. 7'rdc/n/te (from the Greek trachus, rough) is a rock often 
 rough to the touch, as its name indicates, composed of albite or 
 rya'colite, sometimes compact, of a ceroid or vitreo-resinous, and 
 occasionally earthy lustre, sometimes crystalline, the mass being 
 finely porous, containing crystals of the same substances, and often 
 also hornblende and black mica. 
 
 Albite (from the Latin, o/feus, white), a mineral so called from its colour, 
 which contains si'lica, alu'mina, and soda. A lamellar variety is found at 
 Chesterfield, Mass., called Cleavelandite, in honour of Professor Cleaveland. 
 
 Rya'colite (from the Greek, ruax, a stream, and lithos, stone), is a glassy 
 mineral, of a greyish-yellow to white colour, or colourless. Besides si'lica, 
 alu'mina, and soda, rya'colite contains potash. 
 
 39. What are the general characters of the solid products of volcanoes ? 
 What is tra'chyte ? 
 
SOLID VOLCANIC PRODUCTS. 121 
 
 Hornblende (from the German), a kind of dark or black variety of mine- 
 ral, belonging to the same group as tre'molite, acti'nolite, asbe'stus, &c. 
 
 Mi'ca (from the Latin, mico, I shine), is a mineral generally found in 
 thin, elastic laminae, soft, smooth, and of various colours and degrees of 
 transparency. It is one of the constituents of granite and its associate 
 rocks. 
 
 40. 2d. Obsi'dian (from the Greek, opsis, view, or after Obsi- 
 dius, who first found it in Ethiopia}, is a homogeneous, vitreous 
 substance of various colours. By me ancients it was used in. 
 place of glass, and is also called volcanic glass. It consists of si'li- 
 ca, alu'mina, with a little potash and oxide of iron. 
 
 This substance is produced abundantly in the islands of Lipari 
 and Teneriffe, the volcans of the Andes, and wherever volcanic 
 apertures open in tra'chyte. 
 
 41. 3d. Compact lava. A substance with a compact base of a 
 deep colour, most frequently formed of labradorite, containing crys- 
 tals of the same substance, or of the feldspa'thic group in general, 
 which in the mass presents a more or less distinct porphyritic struc- 
 ture. Crystals of py'roxene, of am'phibole, black mica and peri- 
 dote are also occasionally found. 
 
 La'bradorite Labrador spar. A beautiful variety of opalescent feldspar 
 from the coast of Labrador : it exhibits brilliant and mutable tints of blue, 
 red, green and yellow, and is susceptible of a good polish. It is cut into 
 small slabs, and employed in ornamental jewelry. It is a si'licate of alu'- 
 mina, lime, and soda, with traces of oxide of iron. 
 
 Py'roxene (from the Greek, pur, fire, and zenos, stranger). The augite, 
 supposed to have pre-existed in the volcanic minerals containing it, and riot 
 to have been formed by fire. 
 
 Am'phibole (from the Greek, amphibolos, equivocal). A name applied by 
 some mineralogists to hornblende, because it may be mistaken for augite. 
 
 Peridote, or Chrysolite (from the Greek, chrusos^ gold, and lithos, stone), 
 from its colour. The topaz of the ancients. 
 
 These substances constitute the centre of thick currents, the in- 
 ferior part of the mass formed in excavations or hollows ; they are 
 often divided into prismatic columns. 
 
 42. 4th. Porous, or scoria'ceous lava. A substance of the 
 same nature as the preceding, but rarely having crystals embedded 
 in it, and its structure is porous, or cellular. These lavas consti- 
 tute the upper parts of thick layers, and envelope lava currents 
 and streams which rest on the surface of the ground. 
 
 43. 5th. PoKzzolani, volcanic tufa. Masses of small scoria'- 
 ceous fragments, or rapilli, accumulated around volcans, or earthy 
 substances, which contain them in greater or less quantity. Pu- 
 mice-tufas are formed of fragments of pumice, and trdchytic con- 
 glomerates of fragments of tra'chyte, unite'd by crystalline or earthy 
 cement. 
 
 40. What is obsi'dian ? 41. What is compact lava? 
 
 42. What is scoria'ceous lava ? 43. What is volcanic tufa ? 
 
 11 
 
122 EFFECTS OF WATER. 
 
 44. 6th. To these may be added scoriee in tears, irregular 
 stala'ctites scattered on the surface of volcanoes, and volcanic 
 bombs, which are sometimes found at considerable distances. 
 
 45. Volcanoes furnish annually but a small quantity of materials 
 to the solid crust of the globe, and the upheavals they cause pro- 
 duce very slight change in the elevation of countries where their 
 action is manifest. Nevertheless, if we remember that a great 
 number have been in action since the time of history, and observa- 
 tion shows that a great many more were previously in action, we 
 are led to the conclusion that volcanic substances are important, 
 and their presence must have occasioned great modifications on 
 the surface of our planet. 
 
 LESSON VII. 
 
 INFLUENCE OF EXTERNAL AGENTS ON THE SURFACE OF THE EARTH. 
 Effects of the Atmosphere Degradation Effects of Winds 
 Dunes Effects of Lightning. 
 
 EFFECTS OF WATER. Dissolving power Softening power 
 Denudation Erosion Effects of weight of Water Punning 
 Waters Debacle of Lakes Mud-torrents Slope of Torrents 
 and Rivers Rolled Flints Transportation by Ice and Gla- 
 ciers Action of Waves Deposits formed by Water Geysers 
 Structure of sedimentary Deposits 7a'lus Effects of 
 Transport or Drift Effects of oscillation in Waters Nature 
 of Deposits from Water Coral Reefs Polypa'ria Peat- 
 bogs. 
 
 1. Atmospheric Effects. Variations of temperature, the air, 
 winds, dryness, and moisture, act very perceptibly on most mine- 
 ral substances ; there is not a rock on the surface of the earth which 
 does not present an appearance, externally, totally differing from 
 what is seen internally, when it is broken. This is everywhere 
 seen in escarpments formed by making roads, in mountainous 
 countries, where it is necessary to cut through rocks ; the exterior 
 is discoloured, and more or less extensively disaggregated, corn- 
 pared with the freshly-exposed interior. These effects are not 
 solely produced by a great lapse of time ; a few years are sufficient 
 for them to be shown, not only on the surface, but to considerable 
 depths : these effects are seen in ancient quarries of marble, or of 
 
 44. What other solids are produced by volcanoes ? 
 
 45. What influence do volcanoes exert, on the elevation of countries ? 
 
 1. How are the effects of the atmosphere on rocks manifested? How 
 does frost act on rocks ? Is a very long period of time necessary for the 
 atmosphere to produce its effects on rocks ? 
 
ATMOSPHERIC EFFECTS. 123 
 
 certain granites, and in dressed stone. The effect is more rapid 
 and perceptible, in proportion to the susceptibility of the substance 
 to imbibe moisture, and to dry again ; alternations which produce 
 a very rapid disaggregation, when frequently repeated, as is gene- 
 rally the case in mountains. The substances which degrade most 
 easily, are those of a granular structure, either earthy or crystalline ; 
 those of a foliated structure ; or compact masses, fractured and 
 split on the surface, such as are often seen in mountains. Frost, 
 when it attacks water absorbed by a body, is also a powerful cause 
 of destruction, because the expansion consequent upon it produces 
 a multitude of cracks in all directions. As long as the cold con- 
 tinues, its parts are held together by ice as by a cement ; but when 
 a thaw comes, the. whole falls in scales, grains, or dust. 
 
 Mountains cannot be visited without meeting' evident traces of degrada- 
 tion of this kind. In limestone escarpments (Jig. 204), we see parts of loose 
 
 Fig. 204. Fig. 205. 
 
 Daily effects of degradation in mountains. 
 
 texture, more or less hollowed out, and the more solid banks remain. Hence 
 the falling of the latter, which are successively detached in more or less 
 voluminous blocks. In high mountains (fig. 205), often formed of in- 
 clined strata, which present their cuts or planes to the slope, we observe the 
 most marked degradations ; parts are constantly detached, particularly at 
 times of most sensible atmospheric variations; at the instant of thaw, enor- 
 mous avalanches of stones occur, and roll down the sides with astonishing 
 rapidity, sweeping everything in their course ; sometimes great blocks, and 
 considerable portions of the mountain fall with tremendous noise. Hence 
 the enormous debris which accumulate at the base, sometimes covering a 
 great extent 
 
 2. Degradations attributable to these effects. The degradation 
 which many rocks present is generally attributed to atmospheric 
 influences, lo g continued. Almost all rocks, in fact, are more or 
 less deeply changed, and are in a state of much less solid aggrega- 
 tion, much less homogeneous, on the surface, than they are inter- 
 nally. In almost all quarries, it is necessary to remove a great mass 
 of matter, before obtaining blocks which are homogeneous, solid, 
 free from cracks, and possessed of the bright colours which are 
 ordinarily sought; this is especially the case with marble, and 
 generally, also, with compact limestone. Certain granites are so 
 deeply disintegrated, that the whole surface of the soil presents a 
 
 2. What is meant by degradation of rocks ? What are rocking stones ? 
 
124 
 
 ACTION OF WINDS. DUNES. 
 
 mass of gravel in rounded hills, gullied by the rain in all directions. 
 Frequently we find these granites on the surface of the soil, in 
 great rounded blocks, piled up one on the other (Jig. 206), in the 
 strangest manner, sometimes in unstable equilibrium, and suscep- 
 
 Fig. 206. Degradation of granite as seen in different places. 
 
 tible of oscillating from the slightest effort ; these are termed rock- 
 ing stones, in some localities. 
 
 In mountains where the granite is easily decomposed, we often remark 
 that the mass, more or less cut, is in a sort of horizontal stories, divided by 
 vertical fissures, so as to present a kind of agglomeration of irregular paral- 
 le'llipipeds. It is supposed that, in consequence of atmospheric influences, 
 these angular blocks are altered on their faces and angles ; that the disag- 
 gregated parts are successively detached, producing rounded masses, piled 
 on each other like cheeses, as we now see, sometimes, isolated on the surface 
 of the soil. 
 
 3. Action of winds dunes. Although winds act but very 
 feebly on solid mineral masses, they exert an important influence 
 on deposits of fine movable sands. We know that in the deserts 
 of Africa and Arabia, the winds raise immense clouds of burning 
 sands, conveying them from place to place, and suddenly produc- 
 ing vast hills, sometimes quite high, which a new gale again de- 
 stroys. All sandy sea-coasts are exposed to similar effects ; the 
 least gale sets the sands in motion, and produces, on the previously 
 uniform surface, a multitude of wrinkles or ridges, parallel to each 
 other, separated by a greater or less interval, and each presenting 
 a gentle slope towards the wind, and a more abrupt declivity on the 
 opposite side, as represented (fig. 207); the next gust of wind sets 
 all these ridges in motion, and each one is soon found to occupy the 
 space which separated it from the preceding ridge. This pheno- 
 menon of dunes, or downs, is seen in miniature on the sea-beaches ; 
 and they sometimes invade immense tracts on adjacent planes. 
 These hills, placed one behind the other, in a direction perpendicu- 
 lar to that of the prevailing winds, are constantly in motion, and 
 constantly advance towards the interior of the land ; the wind from 
 
 3. What are dunes ? How are they formed? What is meant by talus ? 
 At what rate do dunes advance ? 
 
EFFECTS OF WATER. 125 
 
 seaward drives the sand from the foot of the hillock (fig. 207, a), 
 to its summit (6), whence it falls in the line /;, c, forming at this 
 point a falling talus, always more abrupt than the first or rising 
 
 Fig. 207. Fig. 208. 
 
 Progress of dunes, or moving sands. 
 
 ta'lus. The result of this is a single hillock, a b c, taken sepa- 
 rately (fig. "ZOS), which grows behind, if new sands be furnished 
 in front, or it is displaced, if the same sands are continually re- 
 moved. Now, the wind acting on all these hillocks at the same 
 time, the mass formed by them is found to have moved a certain 
 di-stance inland, in a short time, while new heaps are formed in 
 front, at the expense of the sands freshly washed up from the sea. 
 It is calculated that dunes advance, in this way, twenty or thirty 
 yards a year; so that it is evident there must have been a time when 
 they were far from the places they have invaded. A great many 
 localities are known, which have been submerged by these seas of 
 sand. 
 
 4. Lightning sometimes produces remarkable effects ; in a great 
 many places and on various rocks, traces of fusion by thunderbolts 
 in high mountains have been observed. According to the observa- 
 tions of Friedler, when lightning penetrates sand, it often forms 
 narrow, irregular canals to a great depth, the sides of which are 
 consolidated by the fusion of quartz itself; and there are instances 
 where considerable portions of rocks have been turned round, torn 
 from their places and hurled to great distances by lightning. 
 
 5. Effects of Water. Water plays a very important part in the 
 changes which are taking place on the surface of the globe ; some- 
 times by its dissolving power, but more frequently by its softening 
 action, its weight, and especially by the motion that may be com- 
 municated to it, and by the transporting power resulting from its 
 rapidity. The extent and importance of modifications from this 
 agent ought to be understood. 
 
 6. Dissolving power. Water exerts a chemical action an some 
 substances which it dissolves, either directly or by means of the 
 carbonic acid it may contain. It acts directly on some salts which 
 it meets here and there, or on some deposits of sulphate of lime, 
 which it corrodes in various ways. When more or less charged 
 with carbonic acid it acts on calcareous rocks, either under ground 
 or where they crop out on the surface ; or in high mountains at the 
 time snows are melting. In this case, the water generally pos- 
 sesses itself of the carbonic acid contained in the air, in greater 
 
 4. What are the effects of lightning on rocks ? 
 
 5 By what properties does water produce its effects on rocks ? 
 
 6. What effects result from the dissolving power of water ? 
 
126 EFFECTS OF WATER. 
 
 quantity than at other times, in consequence of its low temperature ; 
 and running over calcareous masses, it forms furrows which gra- 
 dually deepen, and sometimes cause very considerable falls of rock. 
 These slow effects of water are particularly remarked in the Alps 
 and Pyrenees, where the snows remain a part of the year, and 
 melt by degrees in the fine season. 
 
 7. Softening power. Water, by penetrating argilla'ceous beds, 
 sometimes softens them so much, that they cannot remain on the 
 slopes they occupied, and fall from their own weight ; this is the 
 cause of many falls or slides in sedimentary formations. One of 
 the most remarkable catastrophes of this kind happened in 1806 
 at Ruffiberg or Rossberg in Switzerland, after a very rainy sea- 
 son. The argillaceous matters which cemented the rolled flints 
 forming the mountain becoming softened, a mass of more than 
 50,000,000 of cubic yards was suddenly detached, and precipitated 
 into the valley, forming in it hills sixty yards high, and burying 
 several villages under masses of mud and flints. We often see, 
 on a small scale, thick beds of rock gently slide to the bottom of 
 valleys, on softened argilla'ceous beds which supported them, and 
 tranquilly displace plantations and even the inhabitants on them, 
 without the proprietors perceiving it at the first moment. 
 
 8. Waters which filter through rocks to argilla'ceous layers 
 which may arrest them, and on the plane of which they are 
 directed to the surface, sometimes soften these substances also, 
 carrying away parts successively, and especially sands that may- 
 rest on them, laying bare in this way underlying beds : this is 
 termed denudation. There results from this, at the point where 
 the water breaks forth from the declivity of hills, mo're or less ex- 
 tensive voids, which leave the solid superposed masses without 
 support, which are then dislocated in different ways (fig- 209) and 
 
 Fig. 209. Fig. 210 
 
 Escarpments produced by the action of water. 
 
 soon overthrown. This is frequently seen in certain escarpments, 
 at the base of which are found argilo-arena'ceous layers which con- 
 duct the springs externally. 
 
 7. What are the effects of the softening power of water on rocks ? 
 
 8. What is meant by denudation ? 
 
EFFECTS OF WATER. FALLS OF NIAGARA. 127 
 
 9. Erosion. Something analogous happens when waters, which 
 washing the foot of a mountain, meet there with substances that 
 they can easily soften or disaggregate. These substances being 
 destroyed, the upper parts of the soil are soon undermined, and 
 more or less considerable falls occur. This takes place on sea- 
 coasts, on the shores of lakes or rivers where more or less elevated 
 escarpments are formed, and more and more degraded. The 
 same thing happens sometimes at the foot of cascades which fall 
 over rocky peaks (Jig. 210), forming alternately calcareous and 
 argilla'ceous deposits ; the latter are disaggregated, and borne away 
 little by little by the waters which exude on the parietes or jet 
 forth after the fall, and other layers being undermined must fall 
 sooner or later from their own weight. In this case the cascade 
 cuts deep into the soil, and the same being successively repeated, 
 necessarily forms a gorge or bed the whole length of the rivulet, 
 which deepens more and more. It is in this way that the falls of 
 Niagara, by which the waters of lake Erie are precipitated into 
 those of lake Ontario, have sensibly receded since the discovery 
 by Europeans, and probably have excavated the deep bed through 
 which they afterwards escape. 
 
 " The waters, after cutting through strata of limestone, about fifty feet 
 thick in the rapids, descend perpendicularly at the falls (of Niagara) over 
 another mass of limestone about ninety feet thick, beneath which lie soft 
 shales of equal thickness, continually undermined by the action of the spray, 
 driven violently by gusts of wind against the base of the precipice. In, 
 consequence of this disintegration, portions of the incumbent rock are left 
 unsupported, and tumble down from time to time, so that the cataract is 
 made to recede southwards. The sudden descent of huge rocky fragments 
 of the undermined limestone at the Horse-Shoe Fall, in 1828, and another 
 at the American Fall, in 1818, are said* to have shaken the adjacent country 
 like an earthquake. According to the statement of our guide in 1841, 
 Samuel Hooker, an indentation of about forty feet has been produced in the 
 middle ledge of limestone at the lesser fall, since the year 1815, so that it 
 has begun to assume the shape of a crescent, while within the same period 
 the Horse-shoe Fall has been altered so as less to deserve its name. Goat- 
 Island has lost several acres in area in the last four years (prior to 1841) ; 
 and I have no doubt that this waste neither is, nor has been, a mere temporary 
 accident, since I found that the same recession was in progress in various 
 other waterfalls which I visited with Mr. Hall, in the state of New York. 
 Some of these intersect the same rocks as the Niagara for example the 
 Genesee at Rochester ; others are cutting their way through newer forma- 
 tions Allan's creek, below Le Roy, or the Genesee at its upper falls at 
 Portage. Mr. Bakewell calculated that, in the forty years preceding 1830, 
 the Niagara had been going back at the rate of about a yard annually ; but 
 I conceive that one foot per year would be a much more probable conjecture, 
 in which case 35,000 years would have been required for the retreat of the 
 falls from the escarpment of Queenston to their present site, if we could 
 assume that the retrograde movement had been uniform throughout. This, 
 however, could not have been the case, as at every step in the process of 
 excavation, the height of the precipice, the hardness of the materials at its 
 
 9. What is meant by erosion ? What are the effects of erosion ? 
 
128 ACTION OF RUNNING WATERS. 
 
 base, and the quantity of fallen matter to be removed, must have varied. 
 At some points it may have receded much faster than at present, at others 
 much slower ; and it would be scarcely possible to decide whether its ave- 
 rage progress has been more or less rapid than now." LyelVs Travels in 
 North America. 
 
 10. Effects of weight. Water acting by its own weight like 
 other bodies, evidently often contributes to such land-falls as we 
 mention, and also exerts a powerful action on the dykes and bar- 
 riers which retain it. We see the unhappy effects of inundations, 
 to which certain countries are subject from their vicinity to rivers, 
 lakes, or seas, retained by natural or artificial dykes. 
 
 11. Action of running waters. To the softening action and 
 weight of waters is often added a new power, from the motion 
 they acquire by running over steep descents. This force is some- 
 times prodigious. The effects are seen after storms which pass 
 over moveable substances, in the deep ravines found to have been 
 excavated. These effects are in proportion to the mass of water, 
 and the rapidity of its motion on a particular point. When a hur- 
 ricane or violent storm bursts on a mountain, the soil is often found, 
 unless it consist of living rock, removed and gullied to great depths. 
 The numerous fissures on the surface of rocks facilitate the action 
 of waters, and a considerable mass of fragments is soon detached, 
 which increase more and more the destructive power of the current. 
 Then blocks of every size are loosened, torn from the mountain 
 and transported to great distances, multiplying the effects ten or 
 even a hundred fold, in proportion to their mass and rapidity of 
 motion. Hence we have great ravines on slopes that were pre- 
 viously unbroken, and an immense accumulation of debris at the 
 foot of the mountain, and especially where the soil or the swiftness 
 of the stream abated. Torrents swollen by circumstances of this 
 kind, or by the sudden melting of snows, also produce frightful 
 ravages; they sweep everything in their way, even the living rock, 
 which they soon attack forcibly by the fragments and blocks they 
 swiftly urge along. Nothing is more terrible than this kind of 
 water-course, and to form an exact idea of the effects one must see 
 a gorge through which it has passed, sometimes rolling along rocks 
 measuring ten or fifteen cubic yards. 
 
 12. Debacle of Lakes. Lakes which sometimes form in valleys^ 
 by avalanches or falls of land, constituting a barrier which retains 
 them, are most fearful in their debacle (sudden escape of their 
 waters from breaking of their barrier), in consequence of an enor- 
 mous mass of water rushing forth in a few seconds. Scarcely does 
 a flow begin through a few rents, before the first opening rapidly 
 enlarges, and in an instant the whole dyke is carried away. An 
 
 10. Does the weight of water contribute to its effects ? 
 
 11. What are the effects of running waters ? 
 
 12. What is meant by debacle ? What are the effects of debacle ? 
 
SLOPES OF TORRENTS AND RIVERS. 129 
 
 enormous volume of water is then precipitated with extreme vio- 
 lence, and nothing can withstand the combined effects of its mass 
 and rapidity. All is overturned, and the most solid rocks, if they 
 project, in the'least, across the direction of the current, are instantly 
 torn away, broken, and transported to great distances. The clear- 
 ing is so complete, at the origin of the current, and in the narrow 
 passages where the slope is rapid, that the exposed rock seems to 
 have been cut by the hand of man. 
 
 13. Mud-torrents, from one cause or another, are also formed, 
 which are not less terrible in their ravages. It sometimes happens, 
 as in Ireland, that turf-beds placed on a slight declivity, after being 
 swelled, more or less arched by retaining rain-water beneath them, 
 cannot resist the first heavy shower, and are set in motion. They 
 run then, in spite of the consistence of the mud, and the gentleness 
 of the descent, with prodigious rapidity, and sweep everything 
 they meet. Under other circumstances, the rain-waters soak in 
 loose, argilla'ceons substances, accumulate in the* midst of them, 
 and, at a certain moment, the dykes of the reservoir give way, and 
 a torrent of thick mud, filled with fragments of rock and even blocks, 
 suspended in the viscid mass, is formed, and rushes with fearful 
 rapidity, overturning everything, and cutting deep ravines. 
 
 14. Slopes of torrents and rivers. The disastrous effects of 
 torrents are in proportion to the descent on which they move ; but 
 it does not necessarily follow that their bed must have a very con- 
 siderable inclination. The most rapid torrents, forming a continu- 
 ous bed and carrying rocks a half-yard in diameter, have a descent 
 of only one or two degrees, and many rivers flow very swiftly on 
 a much less slope a descent of from three to four minutes 
 (sixty to a degree) is about the limit for navigable rivers. 
 
 15. Rolled flints, or pebbles. In the ravages produced, by 
 water-currents, the debris torn from mountains are transported to a 
 greater or less distance, accordingly as the inclination of the soil 
 permits the current to maintain its force for more or less conside- 
 rable distances ; but in proportion as the slopes diminish, the swift- 
 ness decreases, and the larger blocks successively remain behind, 
 at the bottom of the valley, and then those of smaller size, and suc- 
 cessively the sand and mud, which are often carried enormous dis- 
 tances. In this rolling of different substances, the blocks and frag- 
 ments sinking during their transportation, rubbing against each 
 other and against the soil, gradually lose their prominences and 
 angles, and in the end become completely rounded, forming what 
 are termed rolled flints, which may be more or less voluminous. 
 
 1 3. How are mud-torrents formed ? What are their effects ? 
 
 14. Upon what do the effects of torrents depend ? What is the rate of the 
 slope of beds of rivers that are navigable? 
 
 15. How are rolled flints and pebbles produced? W j 
 What is sand ? ^ 
 
 v OF THE 
 
 UNIVERSITY 
 
130 TRANSPORTATION BY ICE AND GLACIERS. 
 
 All the lower part of torrents, where the soil is sufficiently flattened, 
 or the enkrgement of the valley permits the waters to expand, 
 diminishing their depth, and consequently their rapidity, is gene- 
 rally found covered with these flints, which are sometimes accumu- 
 lated in immense quantities, and through which, in its ordinary 
 course, the stream meanders in different ways, in a bed it forms 
 and often changes. Rivers and lakes into which torrents empty, 
 and where they consequently lose their swiftness, are often loaded 
 with these flints ; and this is the cause of the constant elevation of 
 the bed of the river Po (see page 15). Gravel and -saw/, which 
 are merely small flints, the mud which results from their friction, 
 and the earthy particles removed, are always transported far, either 
 immediately into lakes, or seas, or rivers, which deposit them on 
 their banks, and especially at their mouths, which they more or 
 less obstruct. 
 
 16. Rolled flints, or pebbles, are also formed by the action of the 
 waves on fallen 'rocks. In this way, on the coasts of France and 
 England, the silex, or flints of the chnlk, are rounded, by being 
 rubbed against each other, and constitute considerable banks of 
 pebbles or shingle. Something similar must have taken place at 
 points now far inland, where we find blocks round and smooth, at 
 a short distance from rocks from which they were evidently de- 
 tached. 
 
 17. Transportation by ice and glaciers. On the shores of 
 northern seas, the ice envelopes blocks and masses of rock, which, 
 at the breaking up, are floated away on ice-cakes in all directions, 
 and deposited here and there, wherever they may ground, or fall 
 to the bottom of the sea. In this way, in Canada, Greenland, and 
 on the coasts of Nova Zembla, &c., very voluminous blocks are 
 transported from one place to another, and often to very conside- 
 rabFe distances from the point of departure. There is no doubt 
 that many small debris, embedded in the ice, are transported in the 
 same way, and form adventitious deposits of more or less extent. 
 
 18. Glaciers, that is, beds of ice occupying the high valleys of 
 lofty mountain chains, are also very remarkable means of trans- 
 portation. Various circumstances (their great weight chiefly) 
 keep these deposits in constant, though very slow motion, from 
 half an inch to an inch an hour, descending along the slopes on 
 \vhich they rest ; now, the surface of these glaciers is found to be 
 covered with fragments and blocks which have fallen from the 
 surrounding mountains, and the whole is conveyed from the upper 
 to the lower part ; and blocks, often of enormous size, are carried 
 
 16. Are rolled flints, or pebbles, produced by running water exclusively? 
 What is shingle ? 
 
 17. How are rocks transported by ice ? 
 
 18. What are glaciers? At what rate do they move? What are 
 moraines ? 
 
ACTION OF THE WAVES AND OF TIDES. 131 
 
 without friction to considerable distances from their place of origin. 
 These debris, from several causes, always accumulate on the late- 
 ral parts of the glacier, against the side of the valley, and fre- 
 quently in the middle also, from other valleys emptying laterally 
 into it, from which result long, slender hills, designated under the 
 term moraines. All these debris, having reached the inferior ex- 
 tremity of the glacier, tumble into the valley on its slope, and form 
 at its foot other moraines often of considerable height. If, after 
 having increased for a certain time in consequence of a series of 
 cold summers, the glacier diminishes again by a succession of 
 warm, prolonged summers, the moraines of different kinds, aban- 
 doned by the ice, are left on the soil ; some form dykes, of more 
 or less height, at the bottom and across the valley, and others long 
 lines on the flanks of the valley, at a greater or less elevation. 
 
 19. It must be borne in mind that the slopes on which glaciers 
 move are always much greater than those of rivers, and that they 
 never descend at an angle of less than three degrees. This must 
 also be the minimum slope of masses of debris resting on the sides 
 of the valley, in consequence of the rapid melting of the glacier. 
 Thus we have a means of distinguishing the remains of lateral 
 moraines from deposits which may have been made by water-cur- 
 rents, the slopes of which are very much less. 
 
 2i). Striae, channels, polishing of rocks. Among the effects 
 produced by the motion of a glacier loaded with debris, and moving 
 slowly over the exposed face of a rock, is a rubbing, wearing, and 
 polishing of the surface which is passed over. The angles of the 
 rocks passed over are rounded ; deep undulating grooves, nearly 
 parallel and longitudinal, are cut in the surface, and the polished 
 surface of the rock passed over is scratched with fine striae, even 
 when it is of the hardest quartz. These effects are well known 
 to be produced by modern glaciers. 
 
 21. Action of (he waves ami of fides. Waves exert an enor- 
 mous power, particularly where rocks are abrupt and directly ex- 
 posed to the open sea. The shock is sometimes so great that the 
 earth trembles beneath the feet; great blocks of stone are torn 
 up and carried far inland, pushed up against the inclination of 
 the shore, sometimes thrown up vertically on projecting points, 
 where they afterwards roll about like small pebbles : heavy banks 
 of sand and of shingle are often removed, and entire countries 
 have been in a moment destroyed. 
 
 Chronology and tradition of maritime countries furnish numerous in- 
 stances of successive changes, of instantaneous disasters which have oc- 
 curred in a great many localities. Immense ones have taken place, and 
 every day new ones occur on low, sandy coasts, bordering the sea, in many 
 
 19. What is the least slope or angle at which glaciers move ? 
 
 20. What effects are produced on rocks by the movement of glaciers 
 loaded with debris ? 
 
 21. What is the effect of the action of waves ? 
 
132 ACTION OF THE WAVES AND OF TIDES. 
 
 parts of the world : we have famous examples from the mouths of the Scheld 
 to the canal of Jutland, where the Bies-Bosch, the Harlem sea, the Zuyder- 
 Zee, the Dollart, have been produced in the extraordinary irruptions of the 
 ocean ; where numerous changes have taken place in the islands, from the 
 Texel to the mouths of the Elbe, in the windings of Lymfiord, or on the 
 coasts of the Cattegat and of the Baltic : immense cuts, bays, and deep 
 gulfs are formed during tempests, and these are still daily forming by the 
 ordinary action of the waves, which sometimes carry away banks of sand, 
 and sometimes destroy the dykes they had already formed. 
 
 22. The action of waves is not confined to moveable soils, but 
 takes place on the most solid rocks ; and hence those daily modi- 
 fications in the enormous precipices found on the coasts of France, 
 England, and almost all parts of the world. The more abrupt the 
 coast, the more it is exposed to denudation from the waves, because 
 directly breaking them, the shock is felt in all its force. On flat 
 coasts, on the contrary, the wave meeting with no obstacle, ad- 
 vances as long as its force lasts, and until its rapidity is sensibly- 
 lost ; and it carries up in sand and pebbles much more than it 
 destroys, even on the most moveable soils. The natural disposi- 
 tion of solid beds is sometimes opposed, and at others favourable 
 to the action of waves; it is opposed when the beds, being uniform 
 and homogeneous, incline towards the sea ; because the return of 
 the wave along the slope or ta'lus diminishes the action of the suc- 
 ceeding wave, the remaining force of which is spent in merely 
 ascending the plane: the waters are spattered only by the crevices 
 and fissures that may exist in the rock. But the same is not the 
 case when the soil presents an escarpment to the action of the 
 waters (figs. 211, 212): the lower parts, continually attacked by 
 
 Fig. 211. Fig. 212. 
 
 Action of waves on abrupt rocks. 
 
 reiterated shocks of waves, which nothing contributes to diminish, 
 are degraded and excavated successively, and with a rapidity in 
 proportion to the facility with which the substance is disaggregated ; 
 the upper beds being soon undermined, are not long in being pre- 
 cipitated into the sea. In this way considerable portions of coast 
 have been overturned at different times, promontories have disap- 
 
 22. Are all coasts equally subject to the action of waves. What circum- 
 stances diminish the effects of the action of waves ? 
 
ACTION OF THE WAVES AND OF TIDES. 133 
 
 peared, and others have been cut off and separated from the main 
 land. These effects are more rapid in places where a deep sea 
 swallows up the detached blocks, or i^ those where the force of the 
 waves is sufficiently powerful to break up the debris, and wear 
 them one against the other and successively remove them, so that 
 the foot of the escarpment always remains bare. 
 
 23. When masses of debris falling from precipices are not im- 
 mediately removed, a natural rampart is formed against the action 
 of the waves, which break before 
 
 reaching the foot of the escarp- 
 ment (Jig- 213); then it is only 
 in a long time that the debris are 
 worn, rounded, and carried away 
 little by little, depending on the 
 solidity of the rocks of which 
 they are formed. These natural 
 ramparts are imitated as much as 
 possible by piling rocks before 
 the ta'lus we wish to preserve on Fig. 213. Accumulation of debris 
 sea-coasts or river banks. opposing the action of waves. 
 
 24. To the action of waves must be attributed certain excava- 
 tions frequently found, on a level with the sea, in calcareous preci- 
 pices, as well, perhaps, as the arches of greater or less height 
 which traverse certain promontories. Nevertheless, this action 
 does not immediately produce great results, except on matters 
 easily disaggregated, such as chalk, clay, and arena'ceous sub- 
 stances, and it is infinitely slow on more compact and harder sub- 
 stances : in fact, there are points where no effect whatever has 
 been produced within historic times. The erosive power of water 
 does not explain all these facts, nor even the impetuous force of 
 waves ; the soils on which this power is exerted are cracked in all 
 directions, either by previous action, or at the moment of earth- 
 quakes, accompanied by violent agitations of the sea, and it is 
 then they yield to the combined forces to which they are exposed. 
 By this means we can account for isolated rocks, for islands in the 
 vicinity of continents, for those great gaps through which the sea 
 finds passage, for those groups of split rocks which form shoals in 
 the midst of the sea, and for all those severings so common and 
 varied on the coasts of France and England, in numerous islands 
 that extend towards the North Sea, and in a great many localities 
 (Jigs. 214, 215). 
 
 25. Deposits of detritus formed by wafers. Although waters 
 continually degrade certain parts of the globe, they create in a 
 measure new deposits proportioned to those they remove. Tor- 
 
 23. What circumstance protects coasts from the action of waves ? 
 
 24. What effects are attributable to the action of waves ? 
 
 25. How are deposits formed from water ? 
 
 12 
 
134 ACTION OF THE WAVES AND OF TIDES. 
 
 . 214. Fig. 215. 
 
 Examples of rocks eroded and shaped by waters. 
 
 rents, after having torn away blocks and fragments of rocks, re- 
 duced them to rolled flints or pebbles, and carried them to a greater 
 or less distance, deposit them, in proportion as the swiftness of the 
 waters diminishes, in the inferior parts of valleys they run through, 
 or at their confluence with rivers, or in lakes. Hence the masses 
 of debris, sometimes immense, the coarse parts of which are ce- 
 mented by the mud, they deposit at the same time. 
 
 26. Great rivers, running through valleys of little inclination, 
 generally leave behind the coarser parts they have received, and 
 only bear forward those whose weight is in relation to their force ; 
 but as their slope diminishes more and more, becoming almost in- 
 sensible towards the end of their course, they deposit the matters 
 they carry, and in this way generally elevate their bed; and 
 finally they even bar up their passage, and divide into several 
 branches, each of which cuts its way through sands. Rivers have 
 in this manner covered flat countries through which they pass 
 with sand to a considerable depth and extent. In great freshets 
 these sands are often taken up again, transported from one point to 
 another, forming islands in the middle of the river, or alluvions on 
 one of its banks, while the other is hollowed out. In rivers, lakes, 
 or seas, these deposits become most remarkable. There, if the 
 current is not rapid enough to carry the debris to a distance, in 
 spite of the opposition of tranquil waters, or if the waves have not 
 sufficient force to remove the sands and mud which have been 
 deposited; they form deltas at the mouths of certain rivers (see 
 page 16). 
 
 27. The sea itself, which in so many places has made breaches 
 in the main land, in others, heaves up and accumulates enormous 
 quantities of pebbles, formed by the trituration of rocks fallen from 
 precipices, or masses of sand and mud produced by the waves, or 
 
 26. What are the effects of deposits from rivers ? 
 
 27. What are the effects of deposits from the sea ? 
 
ACTION OF THE WAVES AND OF THE TIDES. 135 
 
 brought down by rivers. In this way banks and beaches, of greater 
 or less extent, are formed on coasts, the finer parts of which, car- 
 ried inland by the wind, form dunes (see page 125). There are 
 many places where, accumulations of this kind are daily formed, 
 and many points of coast have been invaded by deposits from the 
 sea from remotest times : sometimes, by a single irruption, entire 
 kingdoms have been covered by sand, and fertile countries changed 
 to arid plains, either in extraordinary tides, or in tempests, or by 
 the sudden displacement of waters consequent on earthquakes. 
 Low countries, exposed to these alluvions, daily grow at the .ex- 
 pense of the waters, and, at certain points, this growth has been 
 estimated at several yards a year. Bays and ports have been filled 
 up in this way ; buildings and towns, formerly situated on the sea- 
 shore, are now far from it ; lakes have been transformed into 
 marshes, marshes into solid land, and islands joined to the main by 
 sands deposited around them. The sea, in some instances, contri- 
 butes to the growth of deltas. 
 
 28. Torrents and rivers transport not only mineral debris, but 
 also organic remains, immense masses of plants, detached from 
 ravines, or by falls. Here and there great masses of materials are 
 formed, especially in rivers which are bordered by immense forests. 
 Great deposits of debris of this kind are formed in the Mississippi 
 and its tributaries ; they there form immense rafts of trunks of trees, 
 interlaced, which are stopped here and there by the sands, and 
 finally are buried under the enormous alluvions daily deposited. 
 The mass of plants that the river carries is so considerable, that it 
 has been estimated at several thousands of cubic yards per hour. 
 
 29. Currents of the sea also often transport immense masses of 
 various vegetables, marine plants, and organic debris of every kind, 
 and from all climates, which are here and there deposited in the 
 bays these currents meet in their course. This is especially the 
 case as regards the great Atlantic current, the Gulf Stream, the 
 strongest and most considerable of all, which extends along the 
 coast of North America to the icy regions, where the polar currents 
 accumulate these debris with those of other parts of the world. 
 
 We cannot doubt, on reflecting on the quantity of debris borne by the 
 waters, that Jakes which receive rivers are filled up, little by little, by the 
 matters daily brought into them ; this is evident, in some places, where 
 marshes and considerable alluvions are thus formed. The same must be true 
 of the bottom of the sea, where all waters finally come ; it is easy to con- 
 ceive there must be daily formed considerable dq>osits of all the substances 
 which are carried there, as well as of those washed away by the waves, and 
 of all the remains of animals which perish in this vast abyss. 
 
 30. Deposits of substances held in solution. Waters degrade 
 
 28. Are all the materials, transported by waters, of a mineral origin ? How 
 are the rafts in the Mississippi formed ? 
 
 29. What effects are due to currents of the sea ? 
 
136 DEPOSITS OF SUBSTANCES HELD IN SOLUTION. 
 
 and carry away different substances ; some they also dissolve, and 
 afterwards deposit them, by evaporation, in form of solid sediments, 
 which are sometimes more or Jess crystalline. To the infiltration 
 of these waters, for example, is due all kinds of stala'ctites (from 
 the Greek stalasso, I drop), which form in various subterraneous 
 cavities, and especially large in caverns found in calcareous coun- 
 tries. Certain waters are rich in dissolved materials, and suffi- 
 ciently abundant to give rise to extensive deposits on the surface 
 of the earth. Those particularly, which, by carbonic acid, hold 
 a great quantity of carbonate of lime in solution, and which, from 
 abundant or numerous springs, give origin to rivulets and even 
 lakes, at the bottom of which is daily formed what is called traver- 
 tin or calcareous tufa. These waters are met almost everywhere, 
 in calcareous regions. Scattered over a flat country, or on the slope 
 of a valley, these waters incrust the plants growing there, and, 
 from these agglomerated and superposed incrustations are formed 
 considerable rocks, the mass of which is consolidated by waters 
 which percolate the interstices they meet, and render the whole 
 solid and uniform. When these waters flow over slopes free from 
 vegetation, they deposit thin and successive layers, following the 
 undulations, the whole forming compact masses which daily grow 
 in thickness. In lakes into which waters of this kind flow, hori- 
 zontal beds of solid calcareous matter are formed, which are often 
 filled with fluviatile, and even terrestrial shells, daily brought 
 into it. 
 
 31. Sands washed up by waves, either in fresh-water lakes or 
 seas, are daily consolidated by waters more or less charged with 
 carbonate of lime. Examples of this kind are seen in the sands 
 of lake Superior, in those of the gulf of Messina, at several points 
 on the coasts of England, of the West-India islands, chiefly at 
 Guadaloupe, New Holland, &c. These arena'ceous substances 
 often become sufficiently solid for building purposes. 
 
 32. Sili'cious deposits. A great many mineral waters, particu- 
 larly those which are warm or hot, contain, besides carbonate of 
 lime, a certain quantity of silex (from the Greek chalis, a pebble) ; 
 on this account many calcareous tu'fas are more or less silicious. 
 But there are springs in which the silex is sufficiently abundant to 
 form considerable deposits of hydrated sili'cious deposits, some- 
 limes nearly pure, and sometimes mingled with other substances. 
 The tu'fas of the geyser in Iceland are deposited for nearly a 
 quarter of a league round the spring, three-quarters of a yard thick. 
 One of these geysers (a word which according to some means 
 spouting, and furious, according to others) spout? up every half 
 
 30. How do waters form deposits from matter held in solution 1 What 
 are stala'ctites? 
 
 31. By what means are sands consolidated? 
 
 32. How are sili'cious deposits formed ? What is a geyser ? 
 
STRUCTURE OF SEDIMENTARY DEPOSITS. 137 
 
 hour a column of boiling water, eighteen feet in diameter and one 
 hundred and fifty feet high. Analogous springs of hot water exist 
 in the Rocky mountains, and in India, as well as in Saint Michael's 
 (Azores), where the sili'cious deposits are found in thin beds, alter- 
 nating with argilla'ceous substances which the same waters bring 
 from the interior of the earth. Organic remains, particularly vege- 
 table, are found in all, some of which have passed into the sili'cious 
 slate, while others have disappeared, leaving only their impressions 
 behind. 
 
 33. Structure of sedimentary deposits. Effects of land-falls. 
 If we examine deposits of de'tritus, formed at the foot of mountains 
 by the daily destruction of its rocks, it will be seen their slopes 
 are very variable, the greatest not exceeding an angle of forty-five 
 degrees, and the least being seldom less than twenty degrees ; the 
 variations between these limits are found to be in relation to the 
 size, the form of the fragments, and circumstances of the fall, 
 rather than to the nature of the substances themselves. Hence it 
 is, if, at different successive fallings, there are variations in the form 
 of the fragments and in the circumstances of the fall, there will be 
 an accumulation of deposits, the slopes of which will be succes- 
 sively less, and which, in ravines ^ 
 
 excavated by water, will have 
 nearly the arrrangement repre- ^ 
 sented, a, b, c, d, e, (fig. 210), | 
 where each additional deposit is II 
 thicker at its base than at the 
 upper part. It is evident the 
 same thing may take place in 
 stagnant waters ; whence it fol- 
 lows that from the fall of a river _. ~ ir 
 into a lake with steep banks, a ** 216.- 7W. from fatting. 
 
 very considerable ta'lus may be formed, and from different acces- 
 sions or growths, which bring materials of different form and size, 
 deposits similar to those just mentioned may be produced. 
 
 34. Effects of transport. If in some places, even under water, 
 beds may be deposited at an inclination of from twenty to forty-five 
 degrees, it must not be inferred that the same is true of extensive 
 deposits, where running waters, if unimpeded, may force the debris 
 in every direction. Here the inclination of the ta'lus is much less ; 
 they never attain even the minimum angle of slopes farmed of 
 fallen matter, and never reach even ten or twelve degrees, only in 
 exceptional cases of very rapid torrents, or rather of true cascades, 
 at the place where they fall into a transverse valley, and where 
 there is as much matter tumbled down as transported. The beds 
 of the most rapid rivers are much less inclined, and the successive 
 
 33. What is the structure of deposits from land-falls ? 
 
 34. Is the angle or slope of a ta'lus always the same ? 
 
 12* 
 
138 
 
 EFFECTS OF TRANSPORT. 
 
 deposits are for the most part nearly horizontal. Gravel and sand 
 which the waves wash upon coasts, are also deposited at very 
 small angles, and slopes of ten degrees are exceptions, even in 
 localities exposed to the strongest billows ; most frequently they 
 are much less, and nearly horizontal. 
 
 35. It frequently happens, during the drift or transportation of 
 matters by currents, and by freshets in rivers, when the bottom is 
 disturbed, that effects analogous to those of sea-winds on dunes 
 are produced. Ridges are formed across the current ; various mat- 
 ters, pushed over these initial hillocks, accumulate behind them, 
 forming a ta'lus of successive fallings, which impart the structure 
 represented in fig. 217. If the river change its course, the undu- 
 lated surface of the first deposit is soon levelled, and quiet deposits 
 are formed above (Jig- 218), from which the preceding may be 
 distinguished by the particular structure attributable to the circum- 
 stances of its formation. 
 
 Fig. 217. Fig. 218. 
 
 Structure produced by the transportation of materials. 
 
 These effects, resulting from a mixture of rapid and tranquil 
 deposits (that is, deposits formed from rapid currents and tranquil 
 waters), are very clearly seen in alluvions on river banks, and par- 
 ticularly in deltas, which terminate their course when the waters 
 have excavated some ravine near by. We then perceive that the 
 mass of the deposit is formed of horizontal layers, having a surface 
 more or less undulated (Jig. 219), which are distinguished from 
 
 
 Fig. 219. Structure of alluvions in rivers. 
 
 each other by the size of the component parts, by the colour, by 
 the structure produced by rapid accumulation, either by pushing 
 forward the matters in the direction of the ordinary current, as in 
 the deposits a and , or in a different direction, as in the deposit c, 
 which indicate counter-currents formed at one time or another. 
 Often there are particular masses, d, formed here and there, which 
 ordinarily consist of coarser gravel, or of different organic debris. 
 
 35. What effects result from transportation or drift ? 
 
EFFECTS OF OSCILLATORY MOTION. 139 
 
 36. Effects of oscillatory motion. Great masses of water, sub- 
 ject, like the sea, to undulalory motion, present another order of 
 facts ; not only are suspended substances deposited there in hori- 
 zontal beds, as a more weighty fluid would do, but the slightest 
 agitation does not permit any material particle to be solidly fixed 
 on planes of the least inclination, but tends, on the contrary, to de- 
 stroy all inequalities of the bottom. It is impossible to ascertain 
 positively these effects at the bottom of the sea ; but the immense 
 number of soundings, taken in all parts of the ocean by navigators, 
 show that all moving bottoms have very slight inclination ; that 
 slopes, at an angle of half a degree, are rare, and that all above this 
 are exceptions : hence it follows, that in great masses of water, 
 beds formed by successive deposits must be entirely horizontal. 
 This fact is most clearly exhibited in certain lakes, which have 
 been entirely or in part dried up, where alternations of beds, of 
 every kind, are seen to be perfectly horizontal ; lakes Superior and 
 Huron furnish examples of this kind. 
 
 3^. This disposition of various matters deposited from water, 
 bed by bed, at the bottom of rivers, lakes, marshes, is termed strati- 
 fication ; the deposits themselves are said to be stratified. This 
 circumstance eminently distinguishes deposits formed by water, 
 from those produced by igneous fusion, which are most frequently 
 massive, or irregularly divided. 
 
 38. Nature of deposits organic remains. Beds of alluvium 
 are formed of rolled flints, gravel, and sand, as well as of various 
 kinds of mud, analogous to matter called clay or argil. They 
 are more or less consolidated, as much by their own weight, 
 as by waters charged with carbonate of lime, or various matters 
 which may penetrate them. In lakes, we see calca'reous and ar- 
 gilla'ceous marls, which have the property of hardening in the air, 
 as has been observed in certain half-dried lakes in Scotland, in 
 modern building-stone found in Hungary, and in lakes Superior 
 and Huron. Similar formations doubtlessly occur in the sea, as 
 waters are sufficiently calci'ferous to consolidate the sands thrown 
 on its coasts ; and the nature of upheaved deposits, in many places, 
 leave no uncertainty in this respect. 
 
 These deposits are frequently filled- with remains of all the organized 
 creatures now living 1 on the surface of the globe. In river alluvium we find 
 remains of fluviatile shells that still live in the same localities, or land shells, 
 such as various snails, brought thither by rivulets ; there are branches and 
 trunks of trees, masses of plants, more or less changed, sometimes partly 
 bitumenized, bones of terrestrial or aquatic animals, rarely human bones, 
 but frequently the remains of art, such as fragments of brick and pottery, 
 &c. 
 
 36. What is the position of strata formed under the influence of undula- 
 tory motion of water? 
 
 37. What is meant by stratification ? 
 
 38. Of what do beds of alluvium consist ? 
 
140 CORAL REEFS. 
 
 Alluvions formed by the sea are very similar ; they contain marine debris 
 of every kind, sometimes alone and sometimes mingled with fluviatile and 
 terrestrial debris, brought into it by rivers. Debris of* human industry, an. 
 chors, boats, &c., are frequent, and even man's remains exist ; not only in 
 cemeteries of villages that have been overwhelmed by sands, but also among 
 the debris cast up by the sea, as at Guadaloupe, where human bones are 
 found in a sand consolidated by a calca'reous tu'fa, and mingled with debris 
 of human art. In deltas formed partly of fresh water and partly by the sea, 
 we find alternate layers, the one filled with marine debris, and the others by 
 those of fresh water; but, under other circumstances, all these remains are 
 found indiscriminately mingled. 
 
 Argilla'ceous, marly, or calca'reous deposits, in lakes, contain the remains 
 of fluviatile and terrestrial mollusks, similar to those now existing in the 
 same regions. Remains of fishes and mammals are also occasionally found. 
 There is no doubt deposits formed in the sea also contain remains of 
 the numerous animals that daily perish. We learn from soundings that the 
 bottom of the sea, in many places, is covered by shells, broken or entire, 
 fragments of madrepore, echinidae, &c., sometimes mingled with sand, 
 sometimes by themselves, constituting considerable banks in progress of 
 formation and consolidation. 
 
 39. Coral reefs. Formations of stony polypa'ria, agglomerated 
 with each other, often of great extent, are thus named ; in inter- 
 tropical regions they constitute a great number of islands, on a level 
 with the sea, or submarine banks, the mass of which rises more 
 and more. It is scarcely twenty years since it was supposed that 
 the little animals \vhich form these deposits, by a calcareous exu- 
 dation, had the faculty of living at great depths in the ocean ; it 
 was thought they began their dwelling, and gradually augmented 
 the mass, until it formed immense mountains, the summits of 
 which constituted the reefs, and that they gave origin to most of 
 the large islands formed in those regions. These microscopic 
 creatures, it was said, tended thus to fill up the ocean, and were 
 preparing prodigious changes on the surface of the globe. But all 
 this exaggeration has disappeared, the observations of MM. Q,uoi 
 and Gaimard having shown, that the species which contribute most 
 to the formation of reefs,^uch as caryophy'llisc (Jig. 220), mean- 
 dri'nse (Jig. 221), and particularly the as'lrcsc (fig. 222), which 
 sometimes cover immense spaces, and various madrepores (Jig- 
 223), cannot exist except at moderate depths, and ten or twelve 
 yards below the surface no trace of them is to be found. It is, 
 then, on pre-existing rocks, already elevated under w r ater, often 
 very steep on the sides, as soundings show, that these animals 
 begin to build ; and from this they afterwards accumulate their 
 solid product to the level of the sea, where their last generations 
 perish. They cannot, then, fill up the ocean ; but the incrusta- 
 tions they form are not the less important, since they are sometimes 
 ten or twelve yards thick, extending over immense spaces, and 
 these are found in a great many places in all seas comprehended 
 
 39. In what parts of the world do we find coral reefs ? How are they 
 formed ? At what depths do polypa'ria live ? 
 
CORAL REEFS. 
 
 Ill 
 
 Fig. 220. Caryophy'llia fastigiata. 
 
 Fig. 223. Madrcpo'ra murica'la. 
 
 Fig. 221. Meandri'na labyri'nthica. 
 
 Fig. 222. Astrea viridis. 
 
 between the tropics. They crown most submarine mountains, and 
 cover thousands of square leagues, distributed among thousands of 
 islands and reefs. 
 
 40. These sa'xigenous polypa'ria, attached to every kind of 
 rock, surround most large islands with their products, forming 
 around them a kind of rampart, separated frequently by deep 
 water. In other instances they form islets, detached or grouped in 
 different ways, and they are, when there are breakers, the more 
 dangerous, because they are not seen before being cast upon them, 
 and because the depth of water is so great as not to afford anchorage. 
 It is these deposits which render navigation so difficult in certain 
 parts of the South Sea, and cause so many deplorable losses by 
 shipwreck. Some of the forms assumed by these deposits at the 
 surface of the sea are particularly remarkable, and are not yet 
 entirely explained ; sometimes these reefs are completely annular 
 
 40. What is the form of coral islands ? 
 
142 
 
 CORAL ISLANDS. 
 
 Fig. 224. Coral island in the Pacific Ocean. 
 
 (fig. 224), with a lake in the centre, enclosed on all sides ; some- 
 times they form broken circles, having- one or more openings 
 through which the centre may be reached ; again, they are in 
 groups of islands, arranged in a circle, and frequently there are 
 several in a series. In these internal seas the water is often very 
 deep but sometimes very shallow, and an immense number of 
 polypa'ria are developed, which sooner or later fill up the space. 
 It appears evident that these circular reefs are the edges of different 
 upheaved craters, upon which the polyps have established them- 
 selves ; this is inferred from the volcanic nature of most islands in 
 the Pacific, and from the manner in \vhich submarine eruptions 
 sometimes take place. Nevertheless, this explanation is not re- 
 ceived as satisfactory in respect to many reefs of the kind, and 
 particularly those which constitute -the Maldives and Lakadives, 
 groups in the Indian Ocean. The great number of circular groups 
 found in certain localities, and the immense expanse which we 
 must suppose craters of elevation to have in other places, are facts 
 urged in objection to the explanation. 
 
 Around cor.il reefs, as well as in the lakes they enclose, soft and white 
 mud of a calcareous nature, analogous to chalk, has been observed, which 
 has sometimes been referred to the disintegration of madrepores, and some- 
 times to dejections of worm's which pierce the polypa'ria, or to those of 
 fishes which feed on them. In many places in the South Seas this mud 
 seems to constitute considerable deposits. 
 
 41. When a reef has reached the level of the water, the sea 
 often covers it with debris of every kind, on which vegetation is 
 afterwards developed. Most low islands in the Pacific have been 
 produced in this way, all of which rest on masses of polypa'ria. 
 A great many other* islands have sprung up on their coasts in the 
 
 me way ; and there are many which will sooner or later grow 
 
 same 
 
 41. How are coral islands formed ? 
 
PEAT, OR TURF BOG. 143 
 
 up in the same manner, for now, at low tide, we may walk over 
 reefs extending half a league from the shore. But one very im- 
 portant circumstance is, that in many places we find precisely simi- 
 lar deposits, composed of the same species of madrepores, in the 
 interior of land at an elevation of from 200 to 300 ya-rds ; this is 
 seen at Timor, where the deposits are ten or twelve yards thick ; 
 at New Holland, Van Diemen's Land, at the Marian Islands, 
 Sandwich Islands, &c., where they rest on argilla'ceous schist, 
 sandstone, limestone, volcanic products, &c. ;. in the Isle of France 
 a similar bank, four yards thick, is found placed between two cur- 
 rents of lava. The existence of these deposits in such situations 
 evidently indicates that all these islands have been upheaved from 
 the bosom of the waters, and often at several different periods, for 
 we often find banks of coral at different levels. 
 
 42. Peat, or Turf Bog. There are daily formed, in different 
 excavations of Jihe surface, in valleys of gentle slope, in low and 
 marshy situations, deposits of vegetable matter, the decomposition 
 of which furnishes a combustible called turf or peat, and the 
 mass bears the name of peat-bog. These deposits are formed 
 only under particular circumstances : they are seen only in places 
 where stagnant waters constantly exist, and only in shallow depths ; 
 the presence of light is necessary to secure vegetation, to which 
 peat chiefly owes its origin. 
 
 The production of peat, to which all aquatic plants contribute, is princi- 
 pally owing, however, to those which are always submerged, and which 
 multiply rapidly; their debris form the principal paste that envelopes all the 
 others, and probably contributes to their decomposition. A number of ter- 
 restrial plants also, brought to these bogs by brooks, contribute to the forma- 
 tion. Frequently large trees are found buried in the mass, particularly in 
 the lower parts, where they accumulate on sands and clays which form the 
 bottom. Often they are seen broken and fallen near the root, which is found 
 attached to the bottom of the bog. In some instances these debris are very 
 numerous, and seem to indicate that entire forests must have been buried 
 on the spot where they grew, before the formation of peat. The plants found 
 in these situations all belong to existing species ; they are resinous trees, 
 oaks, birch, &c. Remains of mammals are often found in peat.-bogs, such as 
 the bones of oxen, the horns of deer, tusks of wild-boars, &c. 
 
 43. Peat-bogs rest on every variety of soil, sometimes even on 
 crystalline rocks ; most generally, however, they overlie deposits 
 of sand or clay, and sometimes the rolled flints of the country. 
 There are places where accumulated debris of plants form but a 
 single mass, of greater or less thickness", more compact and blacker 
 at the lower part than in subsequently formed parts of it ; there 
 are other places where the different beds are separated by sedi- 
 mentary deposits of alluvium. These are formed of sands, clays, 
 calca'reous or argilla'ceous marls, often containing fresh-water shells 
 in great quantity. Sometimes the surface of the deposit remains 
 
 42. What are peat-bogs ? Of what do they consist? 
 
 43. On what do peat-bogs rest ? 
 
144 CONSEQUENCES OF CENTRAL HEAT. 
 
 covered by water, and at others it is covered by a luxuriant vege- 
 tation. 
 
 44. Peat-bogs are numerous in different parts of the world ; 
 they occupy basins or depressions in the soil at different elevations, 
 even in the Alps. One-tenth of the whole surface of Ireland is 
 said to be covered by peat-bog. In the Great Dismal Swamp of 
 Virginia and North Carolina, there is a deposit of peat from ten to 
 fifteen feet in thickness. 
 
 LESSON VIII. 
 
 EXPLANATION OF VARIOUS PHENOMENA. Consequences of Central 
 Heat First effect of cooling Warm Springs Deposits 
 referable to Sediment Fresh-water Deposits Fossils of Ma- 
 rine Deposits Fossils of Carbona'ceous Deposits. 
 
 EFFECTS ATTRIBUTABLE TO UPHEAVAL AND SUBSIDENCE. Shell 
 Deposits and raised Beaches Submarine Forests Tracks of 
 Quadrupeds and Birds Dislocation of Strata Faults Cra- 
 te 1 riform arrangement of Strata Valleys of Elevation Up- 
 heaval without Dislocation Distortion of Strata Origin of 
 Valleys Valleys from Dislocation, from Subsidence, from 
 Folding or Plaiting, from Erosion or Denudation Origin 
 of Caverns. 
 
 Having established the fact of a central heat capable of keeping- every, 
 thing in a state of fusion, at a short distance beneath the surface we inhabit; 
 having shown the actual effects of earthquakes and of volcanic action ; 
 having pointed out those which waters produce, both by denudation, or de- 
 gradation, and the formation of new deposits, it is natural to attempt, by 
 reference to these effects, the explanation of all geological phenomena which 
 have occurred on the surface of the globe from the first moment of its exist- 
 encc. The causes now in action are the same as those which have acted 
 through all time; but doubtlessly they were more energetic at certain epochs 
 than present observation shows. 
 
 ' 1. CONSEQUENCES OF CENTRAL HEAT. The complete fluidity 
 of the globe gave rise to its ellipsoidal form : the heat so long pre- 
 served, and still existing beneath the cooled pellicle or crust, has 
 produced, and is now producing a great number of phenomena. 
 The temperature of the surface is nearly stationary, and has not 
 varied since the period of records, and will not probably change. 
 But before reaching this state, which probably required thousands 
 
 44. Where are peat-bogs found ? 
 
 1 . What influence is central heat supposed to exercise over the form of 
 the globe ? Had the central heat any influence on climate ? How do you 
 account for the fossils of tropical plants and animals being found in northern 
 regions ? 
 
CONSEQUENCES OF CENTRAL HEAT. 
 
 145 
 
 of years, the surface of the earth must have passed through every 
 degree of heat, from the state of fusion in which the centre still is 
 to its present degree of cold ; consequently, there was a time when 
 the temperature of the earth was such as to do away with differences 
 of climate, or an atmosphere of vapour, which, hy overcoming radia- 
 tion, diminished the rigour of winter. Then vegetation, and life 
 generally, could be as equally maintained in all latitudes as in a 
 hot-house. From this it follows, that plants and animals now found 
 only between^the tropics could then live anywhere, even under the 
 poles, which were not then encumbered in ice. It is therefore not 
 astonishing that we should find the remains of these various creatures 
 buried nearly on the spot where they lived, in countries which are 
 now the coldest in the world, and in which it would be impossible 
 for them to live at the present time. 
 
 There is in England, on the island of Portland, and at several places on 
 the continent, intercalated in other deposits, a bed of black matter, called 
 dirt-bed, and small argilla'ceous beds, in which, among a great many vege- 
 table remains, bedded and scattered, are various plants in their place of 
 growth (fig. 225), the roots "of which extend into the fissures of the calca- 
 reous soil beneath. There- 
 fore, there must have been a 
 vegetable soil, on which all 
 the plants now buried in the 
 earth then grew. But all 
 the species found in this bed 
 belong to genera, such 
 cycas and zamia, which 
 now live only in the tropics, 
 and the remains of animals Fi S- ^.Portland dirt-led. 
 
 also belonged to the same zone ; consequently the mean temperature at the 
 time of this formation was very different from what it is now in England. 
 
 Most of the coal deposits of Europe lead to a similar conclusion. Entire 
 trees with their roots, many of them still erect, are found, as in the mine of 
 Treuil, near St. Etienne (Jig. 226), in the mines of Anzin (North) in Eng- 
 land, in Scotland, &.C., which seem to indicate, as in peat-bogs, plants that 
 grew very near the places where they are now found. It is evident from 
 the perfect preservation of the most delicate parts of plants, the manner in 
 which the leaves are extended on schists, that these remains could not have 
 been carried far. All the remains of plants found in these deposits belong 
 to the equisita'ceae, lofty ferns, to the lycopodea'ceae, &c., and cannot be 
 compared with those now existing in the tropics; consequently, the climate 
 of Europe must have been then very different from what it is at present. 
 
 We find, in the latitudes of Europe, certain beds containing the remains 
 of intertropieal plants, but we also find above them considerable deposits in 
 which are dicotyle'donous plants of the present time. The formation of the 
 Inst deposits, then, must have taken place long after the first; and it is pro- 
 bable that between the epochs, a period of time elapsed, sufficient for cooling 
 the surface of our planet. 
 
 Madrepores of reefs, which now do not exist beyond the tropics, then evi- 
 dently extended to the polar circle. In fact, the limestones of different 
 periods contain a great number, and frequently show that reefs existed corn- 
 parable to those of our days. Facts show that the limits of these banks of 
 zo'ophytes have retrograded, from the period of the deposit of the oldest 
 13 
 
146 
 
 CONSEQUENCES OF CENTRAL HEAT. 
 
 Fig, 226. Vertical stems in the mine of Treuil, St. Elie.nnc. 
 
 limestones to that of the chalk, after which they suddenly retired to their 
 present limits ; in other words, the climate of Europe has grown successively 
 colder. 
 
 First effect of cooling. The idea of complete fusion, and of cooling, which 
 the observation of the phenomena forcibly leads us to admit, also leads us to 
 conceive what must have taken place on the first consolidation of the globe's 
 surface. The first solid pellicle formed underwent, from cooling, more or 
 less contraction, and on this account must have broken in all directions, 
 from the action of the melted matter it covered, swimming in pieces on its 
 surface, and uniting anew more or less irregularly, to be again broken. But 
 assuming greater consistence, and pressing more and more on the liquid 
 part, this must have gushed up through the rents, then more rare, and formed 
 above the crust projecting ridges, of more or less extent, which increased in 
 height in proportion as the resistance of the. crust became greater, and 
 caused stronger and stronger reaction. Hence the first rugosities, the first 
 ridges formed on the surface of the globe, which possibly afforded the first 
 hold for the action of water, the precipitation of which took place, without 
 doubt, long before the temperature of the teirostrial crust had descended to 
 212 of Fahrenheit's thermometer, in consequence of the pressure exerted 
 by the vapour then diffused in the air. From that moment waves produced 
 debris, and arena'ceous matters, and sediments began to form. Probably 
 the water, at a high temperature, charged with the principles disengaged 
 from the solidified masses, like lava of the present time, attacked the stony 
 matters, disintegrated and dissolved them, and subsequently formed chemical 
 deposits, or consolidated the debris. In fact, we find deposit? formed of 
 fragments, of rolled flints and of sands, in the most ancient layers yet exa- 
 mined, and before meeting with organic remains. 
 
 All the solid layers formed beneath the first pellicle, like it, being sub- 
 jetted to the law" of contraction from cooling, must have been filled with 
 cracks in all directions ; therefore the whole terrestrial crust, thus formed, 
 could not have been as solid as might be at first imagined : it could not 
 
WARM SPRINGS. 147 
 
 resist, so successfully as might be thought, the internal actions, which, meet- 
 ing no obstacle in the sedimentary deposits subsequently formed, must have 
 dislocated them in all ways. In fact, there is no deposit on the surface of 
 the globe, either sedimentary or crystalline, which is not found to be cracked 
 in all directions ; even on the upper surface, most rocks are broken in small 
 fragments, to a considerable depth. 
 
 While the crust of the earth was gradually cooling, things must have 
 passed nearly as we have stated ; but, after the temperature hud become 
 stationary, as it is now, it could not' have been the same : the superficial 
 pellicle docs not contract, because it does not grow sensibly cooler. Never- 
 theless, the interior mass is still cooling more and more, although with ex- 
 treme slowness*, and consequently diminishing in volume ; now, the fluid 
 part tending to drag with it that which covers it, and which becomes suc- 
 cessively too large, this must contract on itself, and ridge the surface by dis- 
 locations through its whole thickness. This may take place tranquilly, for 
 some time ; but, at certain moments, the effect cannot fail to take place 
 quickly, and hence the sudden catastrophes experienced on the earth's sur- 
 face. 
 
 All observations, in accordance with geometrical considerations, show 
 that these ridges and these dislocations arc formed according to the great 
 circle of the sphere, and extend over the half of its circumference. 
 
 2. Warm springs. The different degrees of temperature of 
 warm springs are referable to the central heat, which is communi- 
 cated through fissures of greater or less profundity. The waters 
 come to the surface with the temperature of the point whence 
 they started, and, it is known, that at the depth of about 3280 
 yards, they boil. Now it may be readily conceived how, during 
 earthquakes, new hot springs may appear in a country, and how 
 those that existed there may be lost ; in the first instance, all that is 
 required is a fissure, to establish a communication between the 
 surface and a proper depth ; and, for the second, that the existing 
 communication should be interrupted. 
 
 We may easily conceive, also, that before the earth had reached its pre- 
 sent degree of cooling, hot springs must have been infinitely more numerous 
 than they are at present. When, instead of one-thirtieth of a degree, centi- 
 grade per yard, the temperature increased one-third of a degree, that is, ten 
 times more rapidly than at present, and when water boiled at a depth of 325 
 yards, it is clear, there must have been a great many springs at a tempera- 
 ture of 212 Fahrenheit, or of boiling water, and that fumarolles, now rare, 
 were then common. Consequently, the condition of the atmosphere was then 
 very different from what it is now ; thick fogs must have spread over the 
 surface of the earth, in the absence of the sun, and hence radialion towards 
 the celestial space, at present an important cause of refrigeration, must then 
 have been nothing. Winter was consequently less rigorous ; and this ex- 
 plains, too, how so many plants and animals, which cannot now exist in 
 northern climates, could then live in them as between the tropics, and pre- 
 cisely as southern plants now live on northern coasts and islands which are 
 constantly shrouded in thick fogs. The whole earth, tempered by these 
 
 * According to Fourier, a decrease of internal heat of not more than one 
 degree in thirty yards, would require 30,000 years. 
 
 2. How is the temperature of hot springs accounted for ? At what depth 
 do spring waters boil ? 
 
148 DEPOSITS REFERABLE TO SEDIMENT. 
 
 abundant vapours, could then support the same organic creatures ; here we 
 have the reason why mineral beds, of a determined age, differ less in the 
 organic remains they contain, wherever found, than existing creatures of 
 different zones. 
 
 DEPOSITS REFERABLE TO SEDIMENT. 
 
 3. Rolled flints, sand, and mud, are formed by the action of 
 running water and of waves ; and, being transported by these 
 waters, they accumulate in lakes,* in seas, at the mouths of rivers, 
 and on coasts. Whenever we find these kinds of matter accumu- 
 lated in more or less considerable deposits in the interior of coun- 
 tries, we have a right to conclude that there existed somewhere, far 
 or near, high mountains, from which these matters were detached ; 
 water-courses, which carried them ; undulating waters, which 
 heaped them up on their shores, and often lakes and seas, that 
 received them. By the greater or less abundance and size of the 
 rolled flints, we can judge of the mass and force of the waters that 
 transported them; and their nature, and various course or track, 
 ought to lead to the point of their origin, if circumstances have not 
 destroyed the traces left by currents in their course. 
 
 As in the present day we see deposits of shells formed in lakes and seas, 
 we infer that the numerous beds of the same kind we find at all heights, 
 even on the summits of the loftiest mountains, were necessarily formed 
 under water ; the nature of the organic remains enables us to determine 
 whether they were deposited under fresh or salt water, on coasts or in depths 
 of the sea; their mixture, their alternation, indicate mouths of rivers, alter- 
 nations of salt and fresh water, &c. 
 
 4. Deposits from fresh water. These deposits are easily re- 
 cognised from me organic remains they contain being comparable 
 to different genera, sometimes even to different species of animals 
 now living in our lakes and rivers. These are especially remains, 
 impressions, or moulds of shells, like those of the genus limne'a 
 (Jig- 227), planor'bis (Jig. 228), paludi'na (fig. 229), mela'nia 
 \fig. 230), and of land shells of the genus helix. These are all 
 
 Fig. 227. Limne'a Fig. 228.- Piano' rbis Fig. 229. Paludi'na Fig. 230. Mela'- 
 
 longisca'ta. euom'phalus. lenta. niainqnina'ta. 
 
 3. How are rolled flints formed ? What does the presence of a deposit 
 of rolled flints in a country indicate ? What is inferred from their size and 
 quantity ? 
 
MARINE DEPOSITS. 
 
 149 
 
 univalve, unilocular shells. The bivalve shells of fresh-water de- 
 posits, more rare than the preceding, are like mussels u'nio (fig. 
 231), anodo'nta (Jig- 232), cy'clas (Jig. 233), and cyre'na (Jig. 
 234). The entire absence of every species of polypa'ria (figs. 
 
 Fig. 231 U'nio Fig. 232. Anodo'nta Fig. 233. Cy'clas 
 littora' Us. cordieri. obo'vata. 
 
 Fig. 234. Cyre'na 
 trigo'nula. 
 
 235, 236, 237239), and echini'deae (figs. 238240, 241), is an 
 
 important characteristic of fresh-water deposits, which are very 
 common in different parts of the" world. 
 
 5. Marine deposits. These are distinguished by the analogy 
 of the organic remains they contain (figs. 235 to 250) to the' debris 
 
 Fig. M5.Encri'nites 
 monilifo' rmis. 
 
 Fig. <236.j9'piocri'nites 
 rotu'ndus. 
 
 Fig. 237. Cy ' athocri 'nitea 
 planus. 
 
 4. How are fresh-water deposits recognised ? Which are most numerous, 
 univalve or bivalve shells, in fresh-water deposits ? What does the absence 
 of polypa'ria indicate? 
 
 5. How are marine deposits distinguished ? What fossils are character- 
 istic of marine deposits ? 
 
 13* 
 
150 
 
 MARINE DEPOSITS. 
 
 of different animals now living in the seas. Polypa'ria. more or 
 less analogous to those which form coral reefs (figs. 220 to 223 
 p. 141), are highly characteristic; encri'nites (jigs. 235 to 237), 
 
 Fig: 238. Cida'ris corona'ta. Fig. 239 .Different joints of Encri'nites. 
 
 or the remains of their joints (fig. 239) the echini'dese (figs. 
 338 to 241). Not one of these organic bodies is found in fresh 
 water 
 
 Fig. 240. Qnanchytes ovatus 
 from the Parisian chalk"). 
 
 Fig. 'Hl.Spata'vgus ambula'crum 
 (from the chalk of the Pyrenees}. 
 
 Among the marine univalves there are 
 some which are more or less analogous to 
 those of fresh water, mentioned (p. 148), 
 although they are thicker, and more gene- 
 rally covered with tubercles (fig. 242). 
 But, setting aside those on which at first 
 sight there might be some doubt, there are 
 many others which are sufficiently charac- 
 teristic : these are shells whose aperture is 
 terminated by a canal of greater or less 
 length, and belong either to the genus ceri'- 
 thium (fig. 243), of which a small number 
 
 F lg .M.-Tur bo costa'nus. Q{ S* J 
 
 genera mu'rex (fig. 244), volu'ta (fig. 245), &c. ; they are all 
 marine, and abound in calcareous deposits. 
 
MARINE DEPOSITS. 
 
 151 
 
 Fig. 243. Ceri'thium 
 muta'bile. 
 
 Fig. <244.Mu'rex 
 alveola' tus. 
 
 athle' ta. 
 
 Marine bivalve shells generally differ very much from those 
 found in fresh water ; some resemble oysters, and others are almost 
 entirely like them ; a great many are furnished with ribs, or striae, 
 or rugosities (figs. 24(5, 247), and possess, in a word, many cha- 
 racteristics entirely different from those found in the genera we 
 have just mentioned. 
 
 Fig %46.C!iama 
 folia' cea. 
 
 Fig. 247, re'nerica'rdia Mff.<i48.Jfau'tilus 
 
 imbrica'ta. trunca'tus (front the Lias). 
 
 Chambered shells are found only in seas, such as the nautilus 
 (.fig- 248) more or less like numerous species of ammonites (Jig. 
 249), no analogue of which is now living, but with which certain 
 terrestrial strata are filled. 
 
 These deposits are generally formed very slowly, by the accumulation of 
 shells left by dead mollusks as fast as they perish, and not by sudden catas- 
 trophes, which would have heaped them up alive in greater or less numbers. 
 
152 CARBONACEOUS DEPOSITS. 
 
 Fig. 250. Sc'rpula, on the inside of a 
 Fig. 249. jfrnwionz'tes cate'na. Ca'rdium porulo'sum. 
 
 This is proved by the fact that frequently on the inside of shells we find 
 parasitic animals, that attach themselves to bodies of all kinds (Jig. 250), 
 and which could not attach themselves here, in the interior of the shell, if 
 the mollusk had not been previously destroyed. Often the very shell of 
 the parasite is covered by others, showing that the first had long existed in 
 the sea. The shells of bivalves are frequently found separated, showing 
 the animal must have died before they were buried. And there are shells 
 which are pierced by Irthopha'gi, as well as the flints and fragments of 
 limestone which accompany them, leading to the same conclusion. There 
 are of course some exceptions, but these are commonly due to local circum- 
 stances. 
 
 Generally, these shelly deposits are on the spot where the animals lived. 
 In fact, they contain a great number of uninjured shells, the most delicate 
 appendages of which are in a state of perfect preservation ; a circumstance 
 not reconcilable with the idea of transportation by currents, which would 
 have broken the whole and rounded the fragments. Even in decomposition, 
 the finest parts have left their impressions on the substances enveloping them. 
 
 By means of the debris alluded to, we may always recognize marine 
 deposits. 
 
 6. Carbona'ceous deposits. It is undeniable, that the carbo- 
 na'ceous deposits found in different strata of the earth, were pro- 
 duced there by the accumulation of the remains of plants ; this is 
 proved by the numerous and clearly characterized remains of 
 stems and leaves met with, either in the combustible mass or in 
 the earthy matter containing it. On this point all are of one opinion; 
 but all do not agree as to the manner of accumulation of these re- 
 mains. Some geologists suppose that all carbona'ceous deposits 
 result from the sinking of great rafts of divers plants, transported 
 by great rivers, by maritime currents, and sunk in different places; 
 others think, on the contrary, that most of these deposits were 
 formed, in place, in the same manner as peat-bogs, in depressions 
 of the surface to which rivulets daily brought debris from the sur- 
 rounding vegetation. 
 
 6. From what are carbona'ceous deposits derived? How are carbona' 
 ceous deposits formed ? 
 
CARBONACEOUS DEPOSITS. 153 
 
 Opposed to the idea of floating rafts is, the enormous thickness they must 
 have attained, to have produced beds of coal such as are known, between 
 two layers of arena'ceous matter. In fact, taking into consideration the 
 specific weight of wood, the amount of carbon it contains relatively to that 
 of carbona'eeous deposits, we find that the latter can only be twenty-two 
 hundreds, or even seven hundreds (according to the kind of plants), of 
 the primitive volume of the matters which gave origin to them. Besides, 
 estimating the numerous voids left by the irregular interlacing of these 
 debris in a raft, we know that coal, for example, which is formed of the 
 lightest plants, as the equisita'ceee, ferns, &c., cannot be, in the bed, more 
 than thirty-nve thousands of the thickness of the rail that formed it : that 
 is, a coal-bed of from one or two to thirty yards thick, would require the 
 rafts to have been twenty-eight or fifty-seven, to eight hundred and fifty- 
 seven yards in thickness, which evidently exceeds the limits of probability,, 
 and in most seas would be impossible. 
 
 The idea of the formation being analogous to that of peat-bogs does not 
 present this difficulty, arid only requires lime for the accumulation of the 
 necessary organic materials. In the present state of things, this time would 
 be very considerable; for, according to the calculation of M. de Beaumont, 
 on the quantity of carbon annually produced by our forests, not much more 
 than six-tenths of in inch in thickness of coal would be formed, in carbo- 
 na'ceous deposits, in the period of a century. But everything, leads to the 
 belief, that at a mean temperature of 71 (Fahrenheit), when the atmosphere 
 was filled with vapour, and vegetation, in the genera of plants that then 
 grew in our country, was infinitely more vigorous than at present : we are 
 also led to believe that at the epoch of these formations, when the earth had 
 not yet cooled to its present temperature, a great deal of carbonic acid 
 issued from its interior, and the appropriation of the carbon by plants was 
 then more rapid. It is not only for the formation of coal that a long period 
 of time is required ; all sedimentary and calcareous deposits formed only of 
 shells, which acquire much greater thickness than carbona'ceous deposits, 
 have certainly required many centuries to reach this point. 
 
 The hypothesis which assimilates deposits of coal to peat-bogs, is fortified 
 by the different characters they present; such are, not only the trees found 
 erect with their roots, and the remarkable preservation of the leaves in 
 schists, but the deposition in isolated basins, of greater or less extent, seems 
 to indicate swarnps and marshy places formed in depressions of the surface 
 of the soil. These deposits are often surrounded on all sides by rocks of an 
 anterior formation, which form the parietes of the cavity where they took 
 place ; frequently, we also find that a certain number of small basins, inde- 
 pendent of each other, forming part of a more extensive basin of a species 
 of lake filled with contemporaneous arena'ceous matters, on the surface of 
 which there would be formed as many masses of combustible. There are 
 some, too, that extend through the length of certain ancient valleys, and are 
 contained in them. All these circumstances are observable in the deposits 
 of the centre and south of France ; but in the north of France, in Belgium, 
 in England, and in Scotland, it is different. There, the beds of combustible 
 seem to extend over great spaces ; and the assemblage of facts, as well as 
 the immediate superposition of marine limestone, found in all these countries, 
 leads us to suppose that these deposits, now dislocated and separated by seas, 
 have once formed part of the same whole. It was not in swamps or in 
 closed lakes they were formed, but in a vast sea, the receptacle of all the 
 debris of the vegetation of its coasts and islands, that they must have taken 
 place, and in which 'undulatory motion stratified these materials as well as 
 all other sedimentary deposits. 
 
 Certain deposits of lignite were evidently formed in the same manner as 
 coal ; but there are others which constitute irregular masses of wood thrown 
 
154 UPHEAVAL AND SUBSIDENCE. 
 
 pell-mell, more or less bituminous and preserving their tissue, found acci- 
 dentally buried in the midst of sedimentary deposits, and which probably 
 had a similar origin to those transported by great rivers, which are deposited 
 in lakes or conveyed to the middle of seas. 
 
 Remains of shells are rare in deposits of coal, properly so called. There 
 is no trace of them in any of the deposits of the centre of France ; and it 
 is only in the great formation comprising the north of France, Belgium, 
 and England, that some examples are met: marine shells are found in the 
 environs of Liege and of Namur, in Derbyshire, &c. Fresh-water shells, 
 similar to u'nio and anodo'nta, are found in the same place. In most depo- 
 sits of lignite, in which the structure of the wood has generally disappeared, 
 we find, on the contrary, a great number of fluviatile shells, which proves, 
 that the formation of these deposits took place in fresh-water lakes. 
 
 EFFECTS ATTRIBUTABLE TO UPHEAVAL AND SUBSIDENCE. 
 
 7. At whatever height we may find fluviatile deposits on the 
 surface of the globe, there is nothing to excite astonishment; for 
 we readily conceive that lakes could have existed at all heights on 
 continents, and that after their waters flowed away their deposits 
 remained dry on the soil. But we find also marine deposits at all 
 heights, in very extensive beds, and at first sight it is not so easy to 
 account for them. It is evident that such deposits could have been 
 formed only under waters of the sea ; and, as they are now found 
 thousands of yards above the present level of the ocean, we must 
 admit one of two things; either that the water was elevated above 
 these points for a sufficiently long time to form thick beds there, 
 or that these deposits were raised up from the bottom of the sea to 
 the height we now find them. Nothing in the phenomena of the 
 present time warrants a belief, that the sea, which has not changed 
 its level within the time of history, could have been so elevated, 
 long enough to form considerable deposits. The universal deluge 
 of the Holy Scriptures was a catastrophe of short duration, and 
 therefore could not have produced the immense deposits referred 
 to, which, everything leads us to believe, were formed slowly. 
 Besides, this catastrophe is comparatively of modern date, and 
 must be referred to the last modification of the surface ; now, all 
 the deposits of shells of which we speak were, long anterior, and 
 were independent of facts belonging to the history of the human 
 race. Nothing informs us what became of the excess of water (a 
 greater or less volume than now exists) above the present level, 
 without having recourse to divine interference, which must have 
 been frequent in ancient times, to cause 'these waters to appear or 
 disappear a great many times, and even suspend the' action of the 
 laws of equilibrium. In fact, very often deposits of shells, seen 
 here and there at a great height, are not found on corresponding 
 summits, and are represented on the contrary with all their charac- 
 ters, thousands of yards lower down ; hence we must suppose the 
 
 7. How is the presence of marine shells in deposits, at great heights 
 above the present level of the sea, accounted for ? 
 
SHELL DEPOSITS. RAISED BEACHES. 155 
 
 waters were considerably elevated on the first of these points, and 
 remained low on the other, which is absurd, or we must admit that 
 the same animals could live in one place, near the surface of the 
 water, and in another, at immense depths, which is contrary to all 
 observation. Therefore, the only reasonable supposition left is, that 
 of upheaval; an idea supported at least on positive events which 
 have taken place in our own times, and which are, doubtlessly, not 
 the only ones which have been manifest on the surface of the 
 globe. If an upheaving force could suddenly elevate 200 leagues 
 of the coast of Chile (page 99), spreading as far as the islands of 
 Juan Fernandez; if the same effect were slowly produced in all 
 the gulf of Bothnia, in Sweden, and in Finland, over a surface of 
 not less extent, we may comprehend how vast countries might have 
 been elevated anywhere. The enormous liquified mass forming 
 the interior of the globe, oscillating from side to side beneath its 
 thin crust, could emboss it in every direction, and nothing more 
 would be required to raise continents out of the sea, and vary the 
 slight relief in all manners. And let not such effects excite alarm 
 because they appear gigantic; we judge them to be so because 
 we compare them with our feeble powers, for they are nothing 
 compared to the globe itself. What are the 25,660 feet in the 
 height of Himalaya, the highest mountain in -the world, and the 
 24,580 feet depth, the deepest soundings in the midst of the sea, 
 compared with the 19,685,500 feet, measured by the mean radius 
 of the earth ? And notwithstanding such eminences or depths, the 
 sum of which is less than .5000 of an inch to the yard, are rarities 
 on our planet, whose inequalities are not even comparable to the 
 unperceivable irregularities which are formed in our manufactories 
 on moulded glass or metals, which nevertheless pass unnoticed. 
 If to these reflections we add our knowledge of the immense force 
 often exerted, from the interior towards the exterior, none of these 
 phenomena will astonish us. . 
 
 8. Shell deposits, and upheaved or raised beaches. Parts of 
 soil upheaved above the level of the sea, are characterized, on the 
 surface of exposed rocks, by the presence of various shells, that 
 live, ordinarily, attached on a level with the water, such as barna- 
 cles, mussels, &c. ; or by that of some small -deposits of shells, 
 identical with those daily formed at the bottom of neighbouring 
 seas. Now, on examining the hills near the coast of Chile, there 
 has been found on the plateaux (which succeed each other in ter- 
 races, the sides of which are parallel to the present shores), shells 
 similar to those, that have been left dry in our day, and which are 
 . still attached to rocks, as well as shelly deposits, which contain the 
 same organic remains as those now forming in the Pacific Ocean. 
 Is it not most probable that these deposits are indications of suc- 
 cessive upheavals, similar to those which have recently taken place? 
 
 8. How are raised beaches accounted for ? 
 
156 EVIDENCE OF SUBSIDENCE. 
 
 This inference is sustained by observations made on the coast of 
 Peru, near Lima, in the island of San Lorenzo, where, thirty yards 
 above the level of the sea, deposits have been found which contain 
 woven osier, portions of cotton thread, &c., clearly showing that the 
 deposits in question were formed since the existence of man in 
 those countries; as the level of seas has not changed since history 
 began, it is only by upheaval they could be brought to light. 
 
 That the coast of Sweden has been uplifted slowly, has been established 
 by the most exact observations. In digging a canal near Stockholm, in the 
 midst of beds of sand, clay, and marl, filled with shells similar to those that 
 now live in the Baltic, there were found the remains of very ancient ves- 
 sels ; all this country, which must have been, at some period, under water, 
 and in which some ships were wrecked, has been upheaved since the pre- 
 sence of man ; the level of the ocean being invariable. It is therefore evi- 
 dent that the shelly deposit of Uddewalla, in which organic remains of the 
 Baltic are found, seventy yards above the level of the sea, and in which M. 
 Brongniart found balani attached to rocks, as they are on the present coast, 
 is a fact of elevation. Similar deposits and evidence of elevation are met in 
 other parts of the world. The upheaval and subsidence of the temple of 
 Serapis has been already mentioned (page 19). 
 
 In thus admitting that very extensive deposits, formed of shells that are 
 now living in the sea, have been evidently upheaved to greater or less heights, 
 is it not therefore exceedingly probable that the same is true of all the rest ? 
 Why should this not be true in regard to the neighbourhood of London and 
 Paris; to that of the plains of Gascony, Austria, Hungary, Poland, &,c. ? 
 All the shells found in those places are not similar to those in the pre- 
 sent seas; but there exists a considerable quantity of them, and moreover, 
 their preservation is so perfect, in many places, that they seem to have been 
 recently buried. If we admit the fact of elevation, for these deposits, can 
 we refuse it to the chalk that everywhere envelopes them, forming not only 
 the Jura, but a great part of the calcareous mountains of France ; or to any 
 shell-deposits, the organic debris of which bear witness to their marine 
 origin ? 
 
 9. Subsidence of various deposits. Upheaval has been shown ; 
 subsidence is not less demonstrable. At many points, on the coasts 
 of France and England, may be seen, at low tide, very extensive 
 deposits of plants, similar to those now living in those countries, 
 and which appear to have grown on the spot where they are found, 
 for the roots are seen attached to the soil. These deposits rest on 
 earthy matter, covered with leaves, heaped upon each other, or 
 sunk in a peat-like substance. In these places have been found 
 birch-trees, chestnuts, oaks, and fir-trees, sometimes scarcely 
 altered, species of deer, similar to those met in peat-bogs; the 
 whole covered by argillaceous deposits, which contain fresh-water 
 shells. These submarine forests, as they are called, could have 
 grown only on a soil more or less elevated above the sea ; and as 
 they are now found beneath it, and are not uncovered, except in 
 unusually low tides, the earth must have sunk, after the period of 
 regetation. The dirt-bed of Portland (fig. 225, p. 145) shows the 
 
 9. What are submarine forests ? How is the subsidence of deposits 
 proved ? 
 
SUBSIDENCE OF VARIOUS DEPOSITS. 
 
 157 
 
 existence of a vegetable earth or mould, of a soil nearly dry, resting 
 on marine deposits. This bed has been covered by a very thick 
 deposit of lacus'trine limestone, and the whole passes under the 
 green sand which precedes the chalk, and which is of marine for- 
 mation. It is clear, therefore, that there was in those places a cer- 
 tain upheaval of the inferior marine limestone,' on which terrestrial 
 plants grew ; that subsequently a lake, or a deep estuary, \vas 
 formed, in which beds of limestone, sand, andclay, were deposited, 
 filled with fluviatile shells, the entire mass being sometimes from 
 200 to 500 yards in thickness. A subsequent upheaval must have 
 lifted the whole to its present level. 
 
 Around the Paris basin, the deposit of marine limestone, worked for build- 
 ing stone, must have been at first uplifted, at various points, above the sea, 
 to be covered by a fresh- water lake in which lacustrine deposits were formed, 
 and among them the plaster of Paris ; subsequently, it must have been sunk 
 beneath the sea, to be covered by a marine formation, and again uplifted, to 
 be covered by a second fresh- water formation. 
 
 Fig. 251. Impressions of feet of quadrupeds. 
 
 Hundreds of facts of this kind might be cited ; but we will only notice tho 
 impressions of feet and tracks of certain quadrvpeds (Jig. 251) found at Hess- 
 
 berg, near Hildburghausen, in Saxony, 
 on the faces of certain beds of sand- 
 stone, and the impressions of the feet 
 of various birds, found in the valley of 
 the Connecticut, in the United States, in the 
 same deposits (fig. 252). These impres- 
 sions show that the soil was in a degree 
 soft, although partly dry, which is proved 
 by the ridges it presents, and that it was 
 out of water; the sedimentary bed on 
 which these animals walked, is now co- 
 vered by another, which is moulded on 
 these tracks, and afterwards by considera- 
 ble deposits of the same matter which could 
 be formed only under water; it follows, 
 therefore, that the soil, first uplifted enough 
 to enable terrestrial animals to walk on it, 
 was subsequently sunk to receive all those 
 sedimentary deposits, and afterwards was 
 Fig. 252. Bird tracks. again upheaved to its present position. 
 
 14 
 
158 CHANGE OF POSITION OF STRATA. 
 
 CHANGE OF POSITION AND DISLOCATION OF STRATA ATTRIBUTABLE 
 TO UPHEAVAL. 
 
 10. It has been already stated that sand and shells are deposited, 
 under water, in horizontal beds. Indeed, we frequently find them 
 in this position on the surface, even over extensive spaces, and we 
 then find flattened pebbles, valves of oysters, and othershells, lying 
 flat, and turrieulated shells lying on one side ; and everything eon- 
 firming the idea of a slow formation, by the weight of these sub- 
 stances. But it sometimes happens that we see deposits, more or 
 less inclined in certain parts of their extent, raised .up almost to a 
 vertical position, and sometimes entirely overturned ; they stilJ 
 preserve, however, all the characters which show they were at first 
 horizontal, for the debris of shells and pebbles they contain are still 
 found arranged parallelly to the planes of the beds. Besides, there 
 
 are deposits which contain ge'odes 
 of agate, in which are found sta- 
 Ja'cthes with the axis more or less 
 _ inclined (fig. 253), which is di- 
 lectly opposite to the manner of 
 production of these substances. 
 - Consequently, these deposits could 
 Fig. 253. Fig. 254. no t have been formed in the posi- 
 
 tion we find them, for, on the one hand, the debris of shells and 
 pebbles would have rolled over to be surely balanced, or fallen to 
 the foot of the ta'his ; on the other, the stalac'tites would have formed 
 in a vertical position. This last observation, particularly, shows 
 that the beds were at first horizontal (Jig. 254), and that their posi- 
 tion has been changed subsequently to their formation ; this is one 
 of the great geological phenomena we seek to explain. 
 
 The effects of earthquakes, and those of volcanic phenomena, will serve as 
 points of comparison in our inquiry. On one hand, the crevices produced 
 in the soil at the time, t a greater or less depth, can only be the effect of 
 upheaval ; for the separation of parts does not result here from drying-, nor 
 from cooling, which would produce a retreating of the whole mass. It is 
 remarked, in the neighbourhood of cracks, that the soil is no longer on the 
 same plane as the rest of the country; that it is moie or Jess arched, and 
 often one part is more elevated than another. Now, if the soil haye been 
 uplifted, it must follow that the internal beds have been distrbed in their 
 position ; consequently, when in a formation of horizontal strata, a crack is 
 made in a straight line (fig. 255), the beds must be inclined on both sides 
 throiagh their length, like the two slopes of a roof. When several divergent 
 cracS are formed (.256),the beds ought to incline symmetrically around 
 the axis of elevation. 
 
 Now, if we find all inclined beds in one or the other of these positions, 
 we have a right to conclude they have been uplifted by the same causes. 
 11. Faults. When a crack is made, it often happens that one 
 
 10. What proves that the position of strata has been changed by up. 
 heaval? 
 
FAULTS. 
 
 159 
 
 Fig-, 255, 
 
 of the parts of the soil is more elevated than the other, no matter 
 whether the crack remains open or not. These effects are often 
 observed, ad it is presumed they are all produced by the same 
 cause, namely, upheaval. The beds are then inclined in opposite 
 directions (Jig- 257), and one of the 
 parts is more elevated than that which 
 is adjacent ; the junction is sometimes 
 distinguished by subterraneous work, 
 either subsequently filled with gravel, 
 or a slight fissure, or at least by a 
 surface of separation, the planes of 
 
 which are smooth, and sometimes polished or striated vertically, 
 showing a close crack and a rubbing of one part on the other. 
 This arrangement has been called fault (from the German fall, an 
 accident, /a//, or sinking), because one part is lower than the other; 
 faults are observed in every kind of soil, and present crests or 
 ridges extending over great spaces, nearly in a straight line, some- 
 times broken here and there, but the different parts preserve the 
 same direction. 
 
 12. Besides showing themselves on the surface, faults are also 
 perceived under ground, by the disturbance they have caused in 
 beds or veins worked for the benefit of the arts. It is thus, for 
 example, in coal measures, the 
 same bed of coal a, 6, c (Jig- 258), 
 is found so much deranged in its 
 position, that the miner, after 
 having worked on a part of its 
 direction, from d to c, for instance, 
 finds it suddenly end, and would Fig- 258. Bed dislocated by faults. 
 f\l once abandon all his labours, had not experience taught him that, 
 by following the fault, he will find the deposit either above or 
 below the point where it abruptly terminated. Sometimes there 
 results from these disturbances serious mistakes for speculators; 
 
 11. What is meant by a fault? How are faults produced ? 
 
 12. Do faults always show themselves on the surface ? 
 
160 
 
 CRATERIFORM DISPOSITION, 
 
 observing various outcrops on the surface of the ground, , b, c, d 
 (Jig. 259), they have inferred the existence of as many different 
 
 fig. 259. Dislocation, causing a single bed to appear as several. 
 
 beds, and consequently great wealth, when, in reality, it was only 
 one and the same bed dislocated and raised up to different levels 
 by successive faults. 
 
 13. Crate'riform disposition. The known formation of Monte- 
 Nuovo, in explaining to us the uplifting of the beds seen in its 
 crate'riform cavity, leads us to attribute also to upheavals, the 
 epochs of which are unknown, the structure of several other hil- 
 locks of the same country, such as those of the solfata'ra of Puz- 
 zuoli, of Camboldi, of Astroni, &c., where the strata are all raised 
 towards the axis of the excavation found in the centre. In these 
 hillocks, the bottom of the cavity, particularly at Astroni (Jig. 260), 
 presents the point of a tra'chytic dome, which doubtlessly caused 
 the elevation of the surrounding beds of pumice tu'fa. These 
 crater hillocks at once explain all those of the Champs-Phlegreens, 
 which are full at the top, but all the strata of which are raised 
 around the axis (fig. 261) ; probably there would be found at their 
 
 Fig. 260. Cr a le'r if orm disposition, with Fig. 261. Hillock with strata 
 a tra'chytic hillock in the centre. raised toicards the summit. 
 
 base some point of a cone which had not been uplifted with suffi- 
 cient force to crack the summit. When strata 
 are inclined in opposite directions (Jig. 261), 
 like the two sides of a roof, they form what is 
 termed an anteclinal axis ; but when they dip 
 Fig. 262. , oppositely, it is termed a synclinal axis (fig. 262). 
 Similar circumstances are observed in many places, on a greater 
 scale. At Cantal and Monte-Dore, basa'ltic and tra'chytic beds, 
 which could only have been deposited on a horizontal plane, are 
 found raised up around one or more centres, leaving towards their 
 
 point of convergence a crate'riform. 
 basin of more or less extent, or 
 rising around a more or less pro- 
 
 ^ ^ jecting tra'chytic dome (fig. 263), 
 
 elevated around a Me the Peak of Teneriffe, above 
 tra'chytic dome. the escarpments surrounding it. 
 
 13. What is meant by an anteclinal axis ? What is a synclinal axis ? 
 
VALLEYS OF ELEVATION. 
 
 161 
 
 Granitic masses are found under similar circumstances, in the 
 midst of which rise hillocks of basa'lt or scoriae, which doubtlessly 
 followed the first explosion, as at Monte-Nuovo and the island of 
 St. George. 
 
 14. Calcareous countries are not more exempt from these acci- 
 dents than others; only the crate'riform cavities, in place of being 
 nearly circular, are more frequently elliptical, sometimes very 
 much elongated, as seen in the Jura mountains. In general, the 
 length is produced, like cracks, extending to a great distance, and 
 forming along its direction elongated hillocks, in a line with each 
 other, offering here and there more projecting summits. These 
 summits are most frequently rent, and present what are termed 
 dosed valleys, and valleys of elevation (Jig. 264), which are in 
 fact craters of elevation. 
 
 Fig. 264. Plan of a crater of elevation in calcareous countries. 
 
 15. Ruptures of calcareous mountains do not always present the 
 crate'riform uniformity just indicated, but vary much, in this re- 
 spect. One side of the rupture sometimes remains low, while the 
 other is elevated, as represented (Jig. 265). Sometimes the supe- 
 rior beds seem to have retired horizontally, and the inferior strata 
 are arched up between the fractured extremities, as seen (fig. 266). 
 
 Fig. 265. Fig. 266. 
 
 Craters of elevation in calcareous formations. 
 
 Often, among the upheaved beds, some are found which are easily 
 disintegrated, and their projection soon tumbles, inducing the fall 
 of solid strata ; from this we have ridges of rock parallel to each 
 other, separated by little valleys, in which the rain-water flows, and 
 they become covered by vegetation ; in this case the general ridge 
 of the mountain is as represented (fig. 267). Sometimes the 
 summit only presents a mass of calcareous blocks piled one on the 
 other, but arranged in line, as if the work of a mason. Again, 
 
 14. What are valleys of elevation ? What is the peculiarity of crate'ri- 
 fbrm cavities in calcareous countries ? 
 
 15. Are the crate'riform cavities, in calcareous countries, always uniform 
 in configuration ? 
 
162 
 
 UPHEAVAL WITHOUT DISLOCATION. 
 
 when two parallel upheavals take place (fig* 268), it sometimes 
 happens that one portion (a) of the formation is cut off, and then 
 
 Fig. 267. Fig. 268. 
 
 Various disjwsitions of craters of elevation in calcareous formations. 
 
 forms the culminating point of the whole mass, giving the appear- 
 ance of a repetition of certain strata in the same deposit. The 
 central part of the uplifted mass is formed of matters sometimes 
 analogous to those that essentially constitute the formation, and 
 sometimes totally different. 
 
 16. Upheaval and distortion without dislocation. The uplift- 
 ing of strata is often accompanied by ruptures, but frequently there 
 is no apparent dislocation. We have already noticed the isolated 
 mounts or hillocks on the Champs-Phlegreens (Jig. 261), and the 
 same is also seen, for greater or less lengths, which then have 
 more or less projecting sides, or anleclinal lines, formed by the 
 uplifted strata on either side, like the dip of a roof; these effects 
 are similar to those produced by crevices ; but acting on strata of 
 a certain degree of flexibility, like the matters placed in the centres 
 of the preceding figures. The Jura mountains present a number 
 of instances of this ; we often see there different parallel ridges of 
 this kind, clearly marked on the simplest maps, which leave be- 
 tween them valleys of greater or less breadth, on the two slopes of 
 which the beds are uplifted. The result is great undulations in 
 the strata, remarked especially in escarpments, produced by diffe- 
 rent ruptures, which cut the ridges in a great many places. These 
 
 Fig. 269. Distortions of the Jura. Valleys from plaiting. 
 
 , 16. Is upheaval always attended by rupture of strata? 
 clinal lines? How are undulations in strata produced ? 
 
 What are ante- 
 
PLAITING OF SCHISTOSE STRATA, 
 
 163 
 
 undulations on a grand scale, represented Jig. 269, are not inter- 
 rupted except by crate'riform ruptures of summits, previously 
 spoken of. 
 
 17. Plaiting or folding of schistose strata. Distortions are 
 also observed under other circumstances, in which it seems that 
 beds of a degree of flexibility, or in a pasty condition, have been 
 compressed by two opposing forces, rather than uplifted. Certain 
 facts observed in matter of the structure of schist, naturally lead to 
 this idea. It often happens that the laminse of these deposits, instead 
 of continuing on the same plane, horizontal or inclined, are all found 
 very much contorted without ceasing to be parallel, or folded on 
 themselves into a more or less acute zig-zag (Jig. 2^0). The sup- 
 position as to the mode in which this plaiting has been effected, has 
 been verified by experiments made by Sir James Hall. 
 
 Fig. 270. Contortion of schists. 
 
 Fig. 271. Contortion of coal. 
 
 Entirely similar circumstances occur in coal measures ; all the strata of 
 these deposits, both argilla'ceous and combustible, are found plaited, and 
 often at acute angles (Jig. 271) : this is especially remarkable in the coal 
 measures near Mons, in Belgium. 
 
 Now, how did these compressions take place ? In a degree, an explana- 
 tion is required for each locality; but we know that in a deposit of inclined 
 strata, the mass of which is pushed from below upwards, the superior part 
 presses with all its weight on the inferior, and the beds of the latter, being 
 placed between two opposing forces, may fold on themselves, if they are 
 sufficiently flexible. On the other hand, as matters in a state of fusion arc 
 often injected with great force into sedimentary deposits, it is conceived that 
 from this results the lateral compression which produces the same effects. 
 
 18. Origin of Valleys. If. mountains are only the result of dis- 
 locations which have taken place on the surface of the globe, by 
 the force of internal agents, there would be no difficulty in account- 
 ing for valleys. The first idea of the origin of valleys was based 
 on excavation by the erosive action of water ; but then mountains 
 having been previously formed, it is clear that water Avould always 
 follow the natural slope of the soil, and only excavate in that direc- 
 
 17. How is the folding in schistose strata accounted for? 
 
 18. How are valleys produced? What is meant by valleys of disloca- 
 tion ? 
 
Ifi4 ORIGIN OF VALLEYS. 
 
 tion ; when arrested by any obstacle, or in a basin, it would of 
 preference cut through deposits of sand and gravel. We see the 
 contrary of this natural action : valleys do not generally follow the 
 real slope of the soil ; it is not by the lowest part of basins that 
 waters are generally turned, nor through moveable formations that 
 they make a passage. Rivers, in place of having excavated their 
 beds, as was thought, are simply directed by the canals they found 
 already made. Now it is not difficult to go back to the origin of 
 these canals ; they are evidently the result of upheavals, which 
 have embossed or ridged the soil, until then horizontal. It is clear 
 the inflexible beds must have been broken, and consequently a 
 number of cracks were formed, as in the transverse section (jig. 
 272). The cracks became valleys, placed in different relations to 
 
 Fig. 272. Production of valleys by dislocation. 
 
 each other according to circumstances of upheaval: parallel if the 
 action, taking place in a certain direction, extended a sufficient 
 length ; divergent, if the action occurred at one point, as in certain 
 massive mountains ; often perpendicular to the direction of uplifted 
 chains, as the secondary cracks manifested during earthquakes 
 (fig. 255), which occurs especially when the internal action forces 
 crystalline matter through the principal crack. It may be easily 
 conceived that crevices would remain more open in solid matters 
 than in arena'ceous deposits, the falling of which would tend to 
 fill the vacancy ; and this is the reason why rivers seem to shun 
 moveable formations, which they could easily excavate if they had 
 not found a bed ready prepared in another direction. 
 
 19. It must not be concluded, however, that water has no agency 
 in the configuration of valleys. On the contrary, we must believe 
 that when a country has been suddenly rent, causing the accumu- 
 lated waters to flow all at once, that torrents of frightful power 
 were produced, tearing away and removing all parts fractured by 
 upheaval, and they thus modified the passages offered to them. 
 It is probable, also, that certain valleys, which pass through a 
 moveable formation, little disposed to fracture, have been produced 
 exclusively by water. Valleys referable to this origin are very 
 different in character from the first : they follow the natural line 
 of slope ; they change their course on meeting masses which offer 
 resistance, and turn round them to remain constantly in the movea- 
 ble deposits. Such are the valleys which cut through the great 
 deposits of rolled flints found at the foot of the oriental Alps. 
 
 19. How are valleys of erosion produced ? 
 
ORIGIN OF CAVERNS. 165 
 
 Many great rivers have themselves 
 
 cut their beds in the ancient allu'- 
 
 vium (fig. 273), very different from 
 
 that now forming; the Seine, at Pa- _ 
 
 ris, excavated its bed in a deposit t- 
 
 of rolled flints very unlike ths gravel Fig. ^73. Vuthy o/ erosion in a 
 
 it now deposits. moveable formation. 
 
 20. Valleys from disruption, are those which have been pro- 
 duced by cracks of every size, sometimes colossal, during the up- 
 heavals that have brought the land to its present configuration of 
 surface. They generally present abrupt escarpments, in which 
 are seen the section of the fractured strata, the projecting angles 
 on one side often corresponding with the retreating angles of the 
 other. The circles which frequently terminate them above, or 
 those that divide them in their length, are so many craters of ele- 
 vation, most of which are clearly characterized either by the up- 
 lifted strata or the barrancos they present. 
 
 21. Valleys of subsidence are also spoken of, but it does not 
 appear there are any arising purely from this cause. Subsidence 
 is frequently correlative to upheaval ; and valleys as well as craters 
 of elevation may exhibit the effects of bqth, which must have taken, 
 place especially in the circles found along their line, and at their 
 superior extremity. 
 
 22. Valleys from folding or plaiting are produced by two 
 neighbouring upheavals, causing the elevation of strata, and leaving 
 a space between, the slopes of which being formed by their planes ; 
 this is seen in the high parts of the Jura (fig. 269.) Many rivers 
 flow in valleys resulting from two opposite uptiltings of the soil. 
 
 23. Valleys of erosion or denudation are produced in loose 
 formations like ravines, made by rain-storms, the waters of which 
 carry off the materials constituting the soil. 
 
 24. The origin of caverns is one of the phenomena attributed 
 to the action of water ; but, although we find on a level with the 
 sea some caverns of slight depth, which may have arisen from the 
 repeated action of waves, it is difficult to believe that great caves, 
 which are sometimes many leagues in extent, have been produced 
 solely by the action of the waters running through them. The 
 action of water on compact limestone, in which caves are princi- 
 pally found, is so slight, that it has been supposed the open spaces 
 now found, were at one time filled by masses of salt, which the 
 waters had subsequently dissolved and carried away. 
 
 It is presumed, however, that the first origin of caverns is due to cracks, 
 produced in the interior of the soil, which have been afterwards modified by 
 
 20. What are valleys of disruption? 
 
 21. What are valleys of subsidence? 
 
 22. How are valleys from folding produced ? 
 
 23. How are valleys of denudation formed in loose strata? 
 
 24. How is the origin of caverns accounted for ? 
 
166 VOLCANIC CONES AND LAVA CURRENTS. 
 
 different causes. We know, in fact, that during earthquakes, rivers as well 
 as lakes suddenly disappear under ground, sometimes temporarily and 
 sometimes continuously ; it is conceived that the water flows through internal 
 cracks, similar to those produced on the surface, which form canals for its 
 passage. The phenomenon is sometimes coincident with the appearance 
 of some abundant spring in a more or less distant place ; but it often hap. 
 pens also that the water nowhere re-appears, and we must conclude that it 
 runs directly into the sea. All these circumstances explain the disappear- 
 ance of certain rivers, which are swallowed by the earth after a superficial 
 course of more or less extent, as well as the sudden appearance of springs 
 gushing from the side of a rock. They point to the existence of subterra- 
 neous canals, and lead us to think that, dried up by a more or less consider- 
 able upheaval, these canals may have formed the now empty caverns found 
 at all heights, as well as those, the bottom of which are still occupied by a 
 stream of water fed from lakes or rivers on the surface. 
 
 Still, if the real origin of most of these subterraneous cavities be not 
 doubtful, it must be admitted that subsequently important changes took place 
 in the general form and condition of their parietes ; the rounded form, wear 
 and polish of surfaces, grooves, different excoriations, and in all positions, 
 even on the upper part of the vault, an erosive action of which water alone 
 is incapable. It has been thought this liquid might have been charged with 
 carbonic acid gas, which is frequently disengaged from the earth through 
 fissures formed in it, particularly at the time of earthquakes, and that the 
 subsequent effects were owing to its dissolving power. 
 
 LESSON IX. 
 
 EXPLANATION OF VARIOUS PHENOMENA CONTINUED. Deposits 
 attributable to Volcanic Action Lava Basa'lt Action of 
 Basalt on Adjacent Rocks Dolomisation Giants Causeway 
 Tra'chytic Formation Trap Rocks Porphyry Granitic 
 Rocks Injection of Granite Metalliferous Veins Meta- 
 mo'rphism Effects of Erosion. 
 
 I. Volcanic cones and lava currents. When we find conical 
 hilJs isolated, or arranged several together on a line, and covered 
 with scoriae, sometimes having crate'riform cavities at 
 the summit, surrounded by rapilli, we may be certain 
 they are volcanic cones, however ignorant we may be 
 of the epoch of their activity. If on mountain sides, 
 whatever may be their nature, we see long, straight 
 masses., terminated below in a club, hollow in the mid- 
 dle, and thinning out above in a pellicle of dislocated 
 scoriae (fig. 274), their origin cannot be doubtful, 
 although every other trace of volcanic action may 
 have disappeared. These long, straight masses are 
 lava currents. If we find these matters in pebbles, in 
 Jf^ more or less extensive tables, compact below, porous, 
 
 ' cellular, or scoriaceous above, with a nearly uniform 
 
 1. By what features are extinct volcanoes recognised ? 
 
BASA'LTIC DEPOSITS OF DIFFERENT KINDS. 167 
 
 surface, we may conclude they were accumulated on a horizontal 
 soil, or that in a more or less liquid state they flowed into a depres- 
 sion. They are evidently deposits which have issued from the 
 bosom of the earth in a state of fusion. It is by observations of 
 this kind we are enabled to recognise extinct volcanoes, in relation 
 to which the history of the most remote times is entirely mute. 
 
 2. Some of these currents resemble what is called basalt, that 
 is, black rocks with a compact base of la'bradorite, containing 
 black pyroxene, and almost always magnetic oxide of iron. Very 
 frequently there is found in it more or less voluminous nodules of 
 peridote, and sometimes crystals of feldspar, which give it a por- 
 phyritic structure. These currents ordinarily form thick deposits, 
 frequently divided into prismatic columns, sometimes in large 
 irregular pieces, all indicative of slow cooling. "The palisades" on 
 the North River are examples of basa'ltic columns. 
 
 3. Basa'ltic deposits of different kinds. If basa'lt is found 
 in well-ascertained currents, traceable to craters, entirely similar 
 matter is found in very different positions. There is a great deal 
 of it that forms extensive tables of considerable thickness, consti- 
 tuting vast plateaux ; or heaped-up fragments on different moun- 
 tains, at the same level, the heaps corresponding, and seem to be- 
 long one to the other like parts of the same whole, showing a 
 vast dislocated table. Basa'lt also forms isolated masses, hillocks 
 in the midst of planes, sometimes very distant from every 
 other formation of the same kind. It is found in seams, sometimes 
 enclosed in the soil that conceals it, sometimes rising here and 
 there like a wall, or presenting various hillocks on the same line 
 of direction. 
 
 All these dispositions of basa'ltic deposits, as well as currents or streams, 
 are sometimes found together in the same country. In some countries, on 
 the contrary ,'there is no trace whatever of volcanic cones or of currents. 
 In all cases, however, the rock possesses the general characters of basa'it, 
 and seems to rest indifferently on every kind of formation, even on vegeta- 
 ble earth. 
 
 4. Tabular basa'lt brings to 
 mind the great tables of Iceland, 
 especially those of the eruption 
 of 1783 ; they possess all the 
 characters of lava that has been 
 arrested on horizontal planes, or 
 filled depressions. The lower part 
 is compact, crystalline, and most 
 frequently divided into vertical 
 prismatic columns (fig- 275) ; 
 
 and the upper part is porous, eel- Figt w&.Ifebtvm <tf priimatie 
 lular, sco'riform, irregularly di- porous basa'lt. 
 
 2. What is basa'lt ? What does it contain ? What is its form ? 
 
 3. Where is basa'lt found, and under what circumstances ? 
 
168 BASA'LTIC HILLOCKS, OR BOSSES. 
 
 vided, and terminating on a plain horizontal surface. When the 
 mass is composed of several stories, the separations are sometimes 
 formed by thin beds of rapilli, and most generally they are dis- 
 tinguished by alternations of compact and porous matter, which 
 characterizes each particular effusion. 
 
 5. These characters leave no doubt as to the igneous origin of 
 these deposits ; but there are still others. When we can penetrate 
 
 beneath basa'ltic tables, as in cases 
 where they rest on moveable forma- 
 tions, we almost always find the in- 
 ferior part of the mass presents a 
 multitude of appendages (fig. 276), 
 which penetrate into the soil, indi- 
 cating a liquid matter that has been 
 moulded in rents or crevices. The 
 earth on which the mass rests is 
 often found calcined through a great- 
 er or less thickness, and the debris 
 Fig. 276. Appendages of basa'lt of plants it contains are carbonised. 
 in subjacent rocks. On the other hand, there is often 
 
 found on the surface of basa'ltic tables points of scorification, par- 
 ticular elevations, and even crate'riform depressions, towards which 
 the melted matter seems to have retired at a certain moment before 
 solidifying. 
 
 6. Basa'ltic hillocks, or bosses, are of different kinds ; some 
 seem to be the remnants of an extensive table which had been 
 partly destroyed ; in this case the principal mass of the bosse be- 
 longs to one or another species of soil, and the summit only is 
 basa'ltic. In others, on the contrary, the whole hillock is formed 
 of basa'lt, and the base is lost in masses of sand and debris, which 
 prevent us from seeing what is beneath ; some others are attached 
 to veins or seams. The composition of these hillocks, like that of 
 tabular basalt, varies. 
 
 7. Basa'llic veins, or seams. Basa'lt is frequently found in 
 veins. Most frequently the mass of the seam or vein is compact, 
 or irregularly cracked, but it is often divided into prisms, perpen- 
 dicular to the parietes of the crevice, which then become the 
 cooling surfaces (fig. 277). The matters in these seams are rarely 
 scorified, but some instances are met in Vivarais and Auvergne. 
 Most frequently basa'ltic veins are prolonged to the surface of the 
 soil, where they present their out-crop ; but it frequently happens, 
 also, they terminate above in pointed masses (fig. 278), sometimes 
 bifurcated, which are lost in the rocks through which they pass. 
 
 4. What are the characters of tabular basa'lt ? 
 
 5. What is the origin of basa'lt ? 
 
 6. What are the characters of bosses of basa'lt ? 
 
 7. What are the characters of basa'ltic veins ? 
 
BASA'LTIC HILLOCKS, OR BOSSES. 
 
 169 
 
 277. View of prismatic Fig. 278. Basaltic seams of 
 
 basa'lt. Villeneuve-de-Berg. 
 
 This circumstance positively indicates that the basa'lt was not in- 
 troduced from above, and that it could only have been injected 
 from the interior towards the exterior of the earth. Sometimes 
 the vein glides betwixt two strata, which it follows to a greater or 
 less extent ; or, in ramifying, it launches a part of its mass into 
 the interval, and ends by terminating there in a corner, whence it 
 spreads into all the little fissures of the rock. 
 
 8. Along the course of basa'ltic 
 veins, the out-crops of which are 
 seen on the surface of the soil, 
 various isolated hillocks are fre- 
 quently observed (fig. 279), seve- 
 ral together at various distances 
 apart, which appear to be nothing 
 more than partial ejections, like 
 the cones formed along the same 
 crack in modern volcanic erup- 
 tions. Most often they are almost 
 
 entirely composed of scoriae, but Fig. 27 '9. Hillocks on the course of 
 
 some are found which consist of a vein. 
 
 pure basa'lt. Sometimes, instead of hillocks, there are effusions 
 
 of tables of more or less thickness (Jig. 280), which are also 
 
 found along the course of a 
 
 vein. All these circumstances 
 
 tend to explain the formation 
 
 of isolated hillocks, as well as 
 
 the series of hillocks in line, Fi ?' 2 80.-F terminating in table. 
 
 found in a great many localities where the internal vein has found 
 
 here and there an outlet. 
 
 9. diction of basa'lt on adjacent rocks. The calcination of 
 clays, and the carbonisation of vegetable debris lying beneath ba- 
 sa'lt, have been mentioned ; granite traversed by veins of it is very 
 much altered, portions of rocks which have been enveloped in 
 
 8. Mow are isolated hillocks of basa'lt accounted for ? 
 
 IS 
 
170 
 
 ACTION OF BASA'LT ON ADJACENT ROCKS. 
 
 basa'lt are often melted on the surface, quartz and feldspar are 
 cracked, sometimes enveloped or penetrated by vitreous matter. 
 Marls, earthy limestones in contact with basa'lt, or pierced by its 
 veins, and especially fragments of matter drawn into the basa'ltic 
 mass, are converted into compact limestone, sometimes approach- 
 ing the saccharo'id state. These limestones also become magne- 
 sian, and are converted into true dolomites, distinguished from the 
 rest of the enveloping mass by their slow effervescence. Dolomi- 
 sa'tion seems to be due to the presence of igneous products. When 
 basa'ltic veins pass through carbona'ceous deposits, the clays are 
 calcined, the coal is deprived of its bitu'men, and assumes a baccil- 
 lar (berry-like) structure. 
 
 Basa'ltic deposits, in tables, hillocks, or veins, are more abundant on the 
 surface of the globe than all the lavas in ascertained currents, which is, 
 doubtlessly, owing to their mode of ejection. Basa'lts are found in France, 
 on the borders of the Rhine, in Saxony, Bohemia, &c. Iceland contains a 
 great quantity, and the same rocks predominate in the West Indies, at St. 
 Helena, &c., and in almost all the islands of the South Seas. 
 
 Basa'ltic formations are noticed wherever they occur, in consequence of 
 the tendency of the principal rocks to divide into long prisms, the varied 
 arrangements of which have often excited the admiration of the curious. 
 Here all the prisms converge at the summit of a hillock ; there they form 
 magnificent colonnades of the most picturesque appearance; in another 
 place all the columns, broken at the same level, present a pavement com- 
 posed of pieces regularly joined, extending over a greater or less space, and 
 sometimes formed into an amphitheatre, one above the other. The gran- 
 deur, the imposing appearance of these pavements, have obtained for them 
 the name of Giants 1 Causeway. 
 
 The Giants' Causeway in Ireland is famous ; but a similar structure 
 exists in France. Sometimes there are excavations in the middle of ba- 
 sa'ltic masses, or trappean rocks, which resemble them most, some of them 
 forming very remarkable grottoes. The most celebrated is Fingal's cave, 
 
 in the island of Staffa, 
 which is formed in the 
 midst of trap, divided 
 into prismatic columns 
 with the utmost regu- 
 larity, and into which 
 the sea continually beats. 
 Others exist in the ba- 
 sa'lt, properly so called ; 
 there is a famous one 
 on the banks of the 
 Rhine, between Troves 
 " and Coblcntz, near Ber- 
 trich-Baden (Jig. 281), 
 the columns of which 
 are composed of rounded 
 pieces, which has caused 
 Fig. 281.7 Cheese-grotto, at Bertrich-Baden. tnem to be compared to 
 piles of cheeses, whence the name of cheese-grotto, common in the country. 
 
 9. What influence does basa'lt exert over adjacent rocks ? What is 
 meant by dolomisation ? Give some instances of basa'ltic formation, 
 
TRACHYTIC FORMATION. 171 
 
 10. The Tra'chytic formation is very extensive. It presents 
 itself not only in conical hillocks, running in narrow bands, but 
 also in pi led-up tables on the surface; tra'chyte constitutes great 
 mountains, most frequently united in very extended groups, which 
 form very high masses, ordinarily the highest in the country, 
 covered with asperities ; their sides are broken into valleys and 
 deep ravines, with steep escarpments, and with all the circum- 
 stances of lofty chains. The tra'chytic formation is in strong 
 contrast with the igneous rocks we have heretofore studied, al- 
 though close inspection would show them to bear various relations 
 with deposits of basa'lt or lava. 
 
 11. The rocks which constitute the tra'chytic formation are ex- 
 tremely varied. Most of these substances, as their name indicates, 
 are rough to the touch, because they are most generally finely 
 porous, sometimes cavernous, scoria'ceous, pumice-like ; but there 
 are some that are perfectly compact, and present the porphyri'tic 
 structure, frequently with tints of grey, red, brown, or black, on 
 which are white crystals of albi'te and of rya'colite. There are 
 some, more or less earthy, ordinarily of clear tints, called domi'te, 
 because the Puy de Dome is composed of it. The base of all 
 these rocks, which is inattackable by acids, is albi'tic or ryacoli'tic, 
 formed of a multitude of microscopic crystals mingled together, 
 the whole constituting a mass which is more or less compact. The 
 disseminated substances are albi'te, in crystals of greater or less 
 size, rya'colite, black mica, amphibole hornblende, but rarely py'- 
 roxene augi'te. Gluartz in crystals-, and chalcedony in small nodules 
 are also found in it sometimes, and especially in a certain very 
 cavernous species, hitherto found only in Hungary, the cement of 
 which also contains many small striated balls of sphe'rolite (from 
 the Greek spheira, a sphere, and lithas, a stone). 
 
 12. The name pho'nolite (from the Greek photic, a sound, and 
 lithos, a stone) has been given to rocks more or less analogous to 
 tra'chyte, but differing from it in this, that their base is attackable 
 by acids, leaving a residue of rya'colite. These rocks are most 
 often compact, greyish or greenish, sometimes porphyroid, but in 
 which disseminated substances are rare. They are frequently 
 divided into plates or leaves of variable thickness, and in certain 
 cases the whole mass is divided into prismatic columns, which are 
 more frequently divergent and contorted than vertical. Pho'no- 
 lites have been sometimes confounded with certain porphyroidal 
 varieties of tra'chyte, which possess nearly the same appearance, 
 but not the same solubility. 
 
 13. Some tra'chytic formations contain considerable deposits of 
 
 10. Under what forms do we find the tra'chytic formation ? 
 
 11. What are the characters of those rocks which constitute the tra'- 
 chytic formation ? What is domite ? 
 
 12. What is phonolite ? What are its characters ? 
 33. Do all tra'chytic formations contain obsidian ? 
 
172 DIORITE, TRAP ROCKS, &c. 
 
 obsidian and of pe'rlite, with ail their gradations to pumice. Their 
 abundance and character vary according to locality ; they prepon- 
 derate in some countries, while in others scarce a trace of them is 
 to be seen. 
 
 14. Di'orite, trap rocks, amyg'dalo'id, fyc. There is nothing 
 more analogous to basa'lt than certain black rocks, some of which, 
 according to the numerous gradations they present in deposits in 
 which the elements are distinct, must be mixtures of albi'te and of 
 amphibole, and others are of an unknown, or at least doubtful 
 nature. The first are designated in France under the name of 
 di'orite, and in Germany they are known as grunstein. The 
 others have long borne the appellation of trap (from the Swedish, 
 trappa, a stair), the nature of w^hich it is still impossible to deter- 
 mine definitely. These rocks bear some relation, as much by 
 their position in certain localities as by their mineralogical charac- 
 ter, to certain substances called amy^dalo'ids, in consequence of 
 the nodules of various matters they contain, which are known in 
 England as loadstone, and whinstone, the nature of which is often 
 not better known. 
 
 15. For a long time these rocks were supposed to be of aqueous 
 origin ; but it is now ascertained that they are from igneous 
 causes. 
 
 16. At first, in spite of the absence of scoria'ceous matters, 
 these rocks, and especially those named trap, present all the 
 features of basaltic deposits ; they are found in isolated hillocks, 
 or in tables of greater or less extent ; their mass is often divided 
 into prismatic columns, which possess precisely the same appear- 
 ance as basaltic colonnades, giants' causeways, and all the forms 
 of basa'lt. On the other hand, these substances are frequently 
 found in veins ; and it is remarked that these veins or seams ter- 
 minate above in a pointed mass 
 (a, Jig. 282), or in their course send 
 off small ramifications (6) into the 
 rocks through which they pass 
 small masses (c), sometimes isolated, 
 sometimes communicating with the 
 principal mass by a thin seam. The 
 enclosing rocks are sometimes occa- 
 
 Fig.282.-Veins of trap -Iceland. siona]]y perforated by small ramifi- 
 cations, and even to the finest fissures. These circumstances evi- 
 dently show these are not cracks filled from above, and can be 
 regarded only as injections from the interior, thrown with sufficient 
 force to penetrate the smallest fissures, to detach and carry away 
 fragments of rock sometimes found in their substance, as at d. 
 
 17. All these circumstances are exactly the same as those seen 
 
 14. What is di'orite ? What is trap ? 
 
 15. What is the origin of di'orite and trap ? 
 
 16. What are the characters of trap ? In what form is trap met with ? 
 
SERPENTINE PORPHYRIES. 173 
 
 in basa'lt. It is the same with beds, in appearance regular, 
 seen between sedimentary layers ; observation shows they are 
 only ramifications of veins. This is clearly seen at Trotternish, 
 in the isle of Sky (Jig. 283), where a great seam of trap commu- 
 nicates with a bed of similar matter, which is itself divided further 
 on into three branches. Hence it is evident the intercalation of 
 
 Fig, 283. Injection of trap into sedimentary rocks. Isle of Sky. . 
 
 tra'ppean rocks in arena'ceous beds is the result of an injection, 
 which followed the separation of the beds of the sedimentary de- 
 posit to a greater or less distance, as in the case of the basa'lts of 
 Villeneuve-de-Berg (fig. 278). 
 
 18. Ser'pentine and Didllage ; different porphyries. Magne- 
 sian rocks, called ser'pentine, often accompany trap and di'orite ; 
 they very frequently form seams or veins of themselves. Ser'- 
 pentines and eu'photides are often injected in all manners into cal- 
 careous deposits belonging to the jura'ssic period. Sometimes 
 they form veins, sometimes thick strata ; they often present brec- 
 cias of every species which constitute the marbles called verd 
 anti'que, verd d* Egypte, &c. The limestones mingled with these 
 rocks are all in the saccharoid state, and furnish the most beautiful 
 statuary marble and the most brilliant breccias; yet, if we ex- 
 amine them carefully, we find they belong entirely to the compact, 
 and more or less earthy limestones, the surrounding deposits of 
 which they are evidently a continuation. The schistose clays and 
 sandstone, which alternate with the last, are found converted in 
 the others into jaspers of different varieties. 
 
 The appearance of pyroxenic rocks, mela'phyries (porphyries, the con- 
 stituents of which are united by a black cement), and other porphyries 
 which belong to them, is productive of circumstances of the same kind ; 
 M. de Buch long since pointed them out in the Tyrol, and subsequently in 
 upper Lombardy. They are also found all along the Alps, arid are repre- 
 sented in the same direction in Provence in the midst of the mountains of 
 Esterel : all is upturned in the neighbourhood of these rocks, which, in 
 " coming to day," have upheaved around them calcareous deposits of dif- 
 ferent formations, dislocating, and placing them in the most abnormal posi- 
 tions. Wherever they are in contact with these porphyries, and to a con- 
 siderable distance beyond, limestones are transformed into dolomite, and in 
 such a manner that the same deposits are of simple limestone in some part?, 
 and of dolomite injected into those which are near to rocks of crystalliza- 
 tion. What is most remarkable is, that the few organic remains met in 
 
 17. How does trap resemble basa'lt 1 
 
 18. What is serpentine 1 What is verd antique 1 
 
 15* 
 
174 
 
 GRANITIC ROCKS. 
 
 these modified limestones, even the shells of rnollusks or madrepores, are 
 found changed into magnesia ; this clearly proves that an action subsequent 
 to the formation of the deposit has produced dolomisa'tion, for no shell or 
 madrepore exists which naturally contains magnesia, either in the living or 
 fossil state, where the deposit has undergone no modification. 
 
 Feldspathic porphyries are often so characterized that there can be no 
 doubt of their igneous origin. Not only are they found in veins in the 
 midst of rocks, but they act like trachytes, in passing through split 
 rocks, the fragments of which they glue together to form conglomerates ; 
 they often unite themselves in the most intimate manner to arena'ceous de- 
 posits which harden in their vicinity. 
 
 19. Granitic rocks. There can be no doubt as to the igneous 
 nature of the preceding rocks, from the manner in which they are 
 injected into all kinds of deposits, and from the modifications they 
 produce in the substances they pass through or upheave. The 
 same is true of all granitic rocks, that is of granite properly so 
 called, of syenites, which resemble them more or less in appear- 
 ance, and pass into them in all manners, of certain gneiss rocks, 
 which belong immediately to one or the other, &c. In short, it is 
 inferred from a great mass of observations, collected first in Eng- 
 land by Dr. Macculloch, afterwards verified by other geologists, 
 that the granites, which are massive rocks, and therefore distinct 
 from aqueous deposits, which are ordinarily stratified, act, on their 
 appearance, exactly like the traps, diorites, and porphyries. 
 
 20. In the valley of Glen-Tilt, in Scotland, granite is found 
 injected into calcareous deposits, which alternate with argilla'ceous 
 schists (Jig> 284), into which it sometimes forces separate masses 
 () ; fragments of limestone (6) are also found enveloped in the 
 granite itself. In other places vertical veins traverse the rock 
 (Jig> 285), sometimes entirely, sometimes terminating in pointed 
 
 Fig. 284 
 
 Fig. 285. 
 
 Injection of granite into different rocks. 
 
 19. What is the origin of granitic rocks? What rocks are included 
 under the name of granitic rocks ? 
 ' 20. What circumstances prove the igneous origin of granitic rocks ? 
 
METALLIFEROUS LODES, VEINS, MASSES. 173 
 
 masses, like the dio rites and basa'lts, which also shows that the 
 matter came from below upwards, and that it was driven with 
 great force. These facts do not present themselves in a particular 
 locality only, but are observed in all parts of the world. 
 
 The state of pasty fusion in which the granites were, is indicated by the 
 manner in which these rocks are enveloped in certain sedimentary deposits, 
 or effused on the different soils they pass through. In the coal-measures 
 of La Pleau, to the south-west of Ussel, a portion of the formation has been 
 enveloped by porphyroid granites, which are found above and below. ' The 
 coal is there hard, as on all the plateau, and the deposit is very irregular. 
 In a great many localities, we find granite superposed on all sedimentary 
 deposits from schists, and the most ancient rocks, to those of the jura'ssic 
 period. There are different places in the Alps, where one may touch at the 
 same time, superposed rocks of crystallization and the subjacent sedimentary 
 deposit. 
 
 The action of granitic rocks on those through which they pass is the 
 same as that of the preceding rocks ; compact, o'olitic, and earthy lime- 
 stones are converted into saccharoid limestones, from which organic re- 
 mains have most frequently disappeared ; they assume bright colours of 
 every kind, green, red, black, &c., and, in contact with mica, are filled with 
 garnets and various other crystalline substances. They are often converted 
 into dolomites, which are nowhere more abundant than in formations of 
 granite and sometimes into gypsum, as proved by the out-croppings of this 
 substance in certain parts of the Alps. Clays, and various arena'ceous sub- 
 stances are transformed into jasper, and finally assume the characters of 
 mica'ceous or talcose schist, and gneiss. Simple sandstones of sedimentary 
 formations, on the approach of granite, are converted into beds of granular 
 quartz. It sometimes happens that modified schistose sandstones still pre- 
 serve their arena'ceous structure, although they may have become very 
 solid ; even the mica-schists to which they pass contain here and there thin 
 strata of sandy quartz, interposed between laminae of mica, which seems to 
 announce the remains of ancient modified sandstone. 
 
 Granitic rocks, referred to different ages, are very abundant on the sur- 
 face of the globe ; being found sometimes in very lofty mountain chains, 
 and sometimes forming rounded hills disintegrated on the surface, and cover- 
 ing considerable extents of country. 
 
 21. Metalliferous lodes, veins, masses. The dolomisa'tion 
 and the sulphatisa'tion of limestones, the presence of various sub- 
 stances in adjacent rocks, are not the only facts referable to the 
 passage of igneous rocks from the bosom of the earth. It also 
 happens that, on the contact of the new with the ancient rock, the 
 deposits are filled with different metallic minerals, either dissemi- 
 nated or injected into fissures, and between beds, or accumulated 
 in small masses, sometimes united by slender threads. This has 
 been remarked by M. Dufrenoy in regard to iron ores in the Py- 
 renees, which are found either in limestone, or placed between 
 sedimentary deposits and the granite which upheaved the solid 
 mass. 
 
 It is evident, lodes or seams of ores are related to igneous action. As to 
 those which are deposited in veins, it is to be remarked, we have never had 
 occasion to follow them to a sufficient depth to ascertain whether they ter- 
 
 21. How are metalli'ferous veins produced ? 
 
176 METALLIFEROUS LODES, VEINS, MASSES. 
 
 minate abruptly, and consequently whether they fill cracks opened from the 
 surface towards the interior ; but they are known to terminate in pointed 
 masses upwards, as at Joachimstal in Bohemia, and in many other places, 
 in small veins which have been worked. This circumstance leads us to 
 think that metalli'ferous veins have been produced by an injection from the 
 interior towards the surface, in the same way as the stony veins we have 
 mentioned. Besides, veins of this sort are strongly united to the others : 
 thus, at Pontgibaud, the same veins are sometimes granitic and sometimes 
 metalli'ferous ; in many other places metalli'ferous veins accompany por- 
 phyritic veins, and even veins of basa'lt, as in Bohemia, and the two sub- 
 stances mutually penetrate each other, sometimes one and sometimes the 
 other being above. On the other hand, we very frequently find in the same 
 localities stony and metalli'ferous veins running parallel to each other, 
 sometimes crossing in different ways, one throwing the other aside, and 
 thus mutually producing more or less marked faults. Sometimes the stony 
 displace the metalli'ferous veins ; sometimes, on the contrary, the latter 
 turn aside the others : in everything they act exactly alike, and it is impos- 
 sible not to refer them to the same origin. It is also remarked that veins 
 generally follow great lines of dislocation of the crust of the earth. 
 
 We find in metalli'ferous veins the influence of those which pass through 
 or accompany them, and which deposit, to a certain extent, substances not 
 previously observed. The influence of the rock passed through is seen in 
 metalli'ferous veins, as well as in those of trap; and it has been long known to 
 miners, that a poor vein in a determined bed at once becomes rich by pass- 
 ing into another, and the contrary : hence, the sudden success and unfore- 
 seen reverses in mining operations. 
 
 22. Metalli'ferous masses being in 
 general but accumulations of small veins 
 running in all directions (fig. 286), or 
 an abundant dissemination in the midst 
 
 of a stony substance of the kind attri- 
 Metalli'ferous b ute( J to t ^ e act i on o f fl re> ^ j s clear 
 
 these deposits are produced in the same 
 
 way as those just mentioned. These masses, the principal of 
 which present us with ores of tin, copper py'rite's, and magnetic 
 iron, are chiefly composed of granites, porphyries, various mag- 
 nesian rocks, in which the ores are found. The metalli'ferous 
 mass of Zinwald, in Bohemia, is a particular granite enclosed in 
 a porphyry; that of Altemberg, in Saxony, is a ' porphyritic mass 
 enclosed in gneiss. The celebrated mass of magnetic iron of 
 Taberg, in Sweden, is a mass of diorite enclosed in gneiss ; that 
 of Cogne, in Piedmont, is a mass of serpentine driven into the 
 calci'ferous mica'ceous schist. 
 
 23. Metalli'ferous lodes in regular beds, are merely veins which 
 have followed the stratification, as we observed in traps (fig. 283), 
 or deposits which were formed in contact with sedimentary beas 
 and the fused matters that upheaved them. But we must not con- 
 found the masses and veins, just mentioned, with certain deposits 
 of o'olitic iron ores found in sedimentary formations. Among the 
 
 22. Of what do metalli'ferous masses usually consist ? 
 
 23. What is meant by the term lode ? 
 
METAMORPHISM. 177 
 
 latter, some form beds of more or less 
 extent in the midst of calcareous forma- 
 tions, others fill wide apertures of little 
 depth, from above, which sometimes 
 communicate with caverns (fig 287) ; p . 2 87.-. 
 but these facts are of a different order f rom t ] le exterior. 
 from those just described. 
 
 24. Metamorphism. From all the facts we have cited (which 
 might be vastly augmented in number by reference to details in 
 many localities), we must conclude that crystalline rocks, which 
 are all formed of si'licates, extensively varied and mixed with each 
 other, have been produced by the action of fire ; that at different 
 epochs they have dislocated, uplifted, or overturned the sediment- 
 ary deposits, modifying the mass in all manners and it is to these 
 great phenomena that are due all the seeming disorder observed 
 on the surface of the globe, as well as all the successive changes, 
 the traces of which may be perceived at every step. 
 
 When we see earthy or compact limestones become crystalline on the 
 approach of these different kinds of rocks to fill with various substances 
 they do not contain at certain distances to be charged with magnesia in 
 cracking in all parts, and to disintegrate with more or less facility ; when 
 schistose clays and arena'ceous substances are converted into different 
 jaspers, and become charged with mica and am'phibole, and assume the 
 characters of gneiss, of mica'ceous or talcose schist ; finally, when sand- 
 stones are transformed into beds of solid quartz, can we be surprised that 
 most modern geologists have adopted the idea of complete changes effected 
 in a great number of sedimentary deposits, and that they resort to this 
 metamorphism, long since perceived by Hutton, Playfair, and Dr. Macul- 
 loch, to explain a multitude of facts, observed especially in deposits anciently 
 designated under the names of primitive and transition formations ? The 
 facts appear so extraordinary, that we may be led to suppose a little ex- 
 aggeration : but we must reject evidence to deny that there are saccharoid 
 limestones, dolomites, mica-schists, gneiss, granular quartz, &c., which are 
 the result of a change produced in earthy or compact limestones, clays, 
 sands, &c. of sedimentary formation : is it then so ridiculous to suppose 
 that such has been their origin in all cases? 
 
 These ideas, now more striking, because they are expressed by a proper 
 word, are nevertheless not absolutely new; all works on geology are actually 
 full of them, and the facts are not less remarkable from being expressed in 
 other terms. There is no description of a country, going back to the time 
 of Saussure, whose works are still remarkable for their fidelity of details, 
 in which are not seen numerous passages of different arena'ceous deposits 
 to rocks of crystallization, of schistose grauwackes to talcose schists, to 
 mica'ceous schists, and from these to gneiss, or the passage of sandstone to 
 different kinds of granite and porphyries on which they rest, &c. Is not 
 the fact of the modifications, now described under the term of metamor- 
 phism, here clearly indicated to which time has added only more details 
 and greater precision ? 
 
 It is certain that in departing from schistose grauwackes, for example, 
 and going towards some mountain or islet of crystallization, we find these 
 
 24. What is meant by metamorphisrn ? Of what do crystalline rocks 
 consist ? 
 
17S METAMORPHISM. 
 
 substances themselves become more crystalline in character, and sometimes, 
 without losing 1 the organic remains they contain, become filled with new 
 minerals ; in Brittany these schists are filled with andalu'site, sometimes 
 staurotides, near all granitic deposits. Elsewhere, as in Vosges, in the 
 mountains of Var, we see them pass to mica-schist ; and the latter to gneiss, 
 which, itself, insensibly becomes granite. Now, as if the intimate union 
 observed were not sufficient, these mica-shists, then the gneiss itself, contain 
 carburetted schist, or even graphite, veins of anthracite, which remind us of 
 the deposits which are found further in the schists of grauwackes, and suffi- 
 ciently marked to determine the pursuit of coal. 
 
 It is, then, evident that all the rocks we have cited, no matter how they 
 may differ, are only modifications, mere metamorphoses of one or all ; and, 
 as it is in approaching granitic rocks, evidently produced by igneous action, 
 that these metamorphoses become more and more marked, jt is clear that it 
 is to the influence of the latter that they are due. The same influence is 
 manifest on the sandstones of different ages, at various points where they 
 are in immediate contact with granite : the modifications are such that the 
 special name, arkose, has been applied to them. They then pass through 
 all shades to granite, and become filled with different substances that they 
 do not contain elsewhere. 
 
 Near porphyritic ejections, schists frequently present modifications of an- 
 other kind. Here the most earthy, and the most evidently sedimentary parts, 
 pass by degrees to compact substances, more and more fcldspathic, preserv- 
 ing more or less of their schistose character, and finally end by containing 
 crystals of feldspar ; elsewhere these same matters pass to solid clays, con- 
 taining veins of limestone, then nodules of the same substance, which as- 
 sume all the characters of amygdaloids, losing, only little by little, their 
 schistose structure. 
 
 The same phenomena are remarked between diverse sandstones and por- 
 phyries that intersect them. The arena'ceous matter gradually hardens, 
 becomes more compact, and finally unites with the porphyry in such a 
 manner that it is not easy to determine where one begins or the other ends. 
 
 All these facts pertain really, with the exception of some details, to ancient 
 geology ; and it is only the manner of explaining them that has changed. 
 Everything conspiring to demonstrate that crystalline substances have been 
 produced by the action of fire, and forced through sedimentary deposits, we 
 now understand that the latter have been modified, or metamorphosed in 
 different ways by their influence, in a degree corresponding to their proxi- 
 mity : the effects entirely cease only at greater or less distances. 
 
 It is conceived that one part of these metamorphoses of sedimentary forma- 
 tions arises from the simple action of heat without new fusion, but sufficient 
 to modify the texture of masses, and even to unite elements in other propor- 
 tions, as happens when transparent glass is submitted to a temperature in. 
 sufficient to melt it, in which, nevertheless, a new crystallization takes place. 
 But this idea is not sufficient of itself; we must conceive another action, 
 which we are not yet able to explain or account for, in virtue of which par- 
 ticular substances have been borne, or developed, in the midst of rocks found 
 in the neighbourhood of divers upturnings, of which the globe is the theatre. 
 We readily conceive of the introduction of sulphuric ac;d, which is frequently 
 formed in volcanoes ; but we do not understand that of magnesia and diffe- 
 rent species of si'licates, and, as respects them, all is still purely hypothetical. 
 We may compare these facts to ctmenta'tion, by means of which iron is 
 converted into steel ; a phenomenon which is manifested not only in contact 
 with carbona'ceous matter, but extends far into the ferru'ginous mass, and 
 even takes place at a distance, according to the experiments of M. Laurent, 
 who has shown that carbona'ceous matter may penetrate iron even through 
 
EFFECTS ATTRIBUTABLE TO EROSION. 179 
 
 porcelain tubes. We also know, from experiment, and many effects ob- 
 served in manufactories, that the peroxide of iron, the oxides of chrome, &c., 
 are vola'tilized, and penetrate the substance of bodies that envelope them. 
 The experiments of M. Gaudin, with a blow-pipe on a de'tonating mixture, 
 show that silex, magnesia, and lime, are also volatile oxides ; the first after 
 fusion, the others before being melted. These facts evidently lead to an ex- 
 planation of all the phenomena of metamorphism, arid the intrusion of 
 foreign substances into sedimentary deposits, either in veins or in a state of 
 dissemination. 
 
 EFFECTS ATTRIBUTABLE TO EROSION. 
 
 We have seen that waters act by the carbonic acid they contain ; by their 
 Weight; by their dissolving power; by their transporting power; by their 
 shock, as in waves of the sea, and thus denude continents. We have also 
 pointed out, that in arena' ceous formations, valleys are produced by erosion, 
 precisely as ravines are formed in sandy soils, by the action of rain-water. 
 Hence we may infer that, in every revolution that movements of the soil 
 must have necessarily determined, the waters, thrown forcibly sometimes on 
 one side and sometimes on the other, must, as in our time during earth- 
 quakes, have ravaged, divided, and modified pre-existing deposits in various 
 ways. Many circumstances may be explained by erosion of waters, and the 
 denudations it occasions. 
 
 25. At first, when we see more or less numerous hillocks of 
 sedimentary matter in a country (Jig. 288), whose summits are 
 
 Fig. 288. Hills produced by denudation. 
 
 nearly on the same level, and whose strata correspond with each 
 other, we are naturally led to consider them as evidence of great 
 removals effected by the waters, at certain epochs, the relative 
 dates of which remain to be ascertained. In this way we explain, 
 according to appearance, all the sections which the sandstones pre- 
 sent on the eastern slope of Vosges ; that remarkable assemblage 
 of peaks of every form seen at Aldersbach, in Bohemia ; the nu- 
 merous hills that cover Ross-shire, in Scotland ; the gypseous hills 
 in the neighbourhood of Paris, all composed of the same beds 
 placed at the same height ; and the division of the basa'ltic tables 
 that crown the hills, in certain localities, as well as the rupture of 
 certain lava-floods that had barricaded valleys, &c., &c. 
 
 Valleys which intersect moveable formations are evidently produced in the 
 same way; and there is no doubt that most of those existing in solid forma- 
 tions, have been modified by erosion of water after the rupture which gave 
 origin to them. In this way we may explain the smoothing of all their 
 parietes, in a great many localities, and the widening of their upper parts. 
 The great lakes sometimes found at the extremity of valleys, as on the two 
 slopes of the Alp.-;, in Switzerland and Piedmont, may be attributed to the 
 afflux of waters which rushed through them, at the period of some great ca- 
 tastrophe, and emptied with violence on the plain in which they terminated. 
 
 25. What forms of surface are attributable to erosion and denudation ? 
 
180 
 
 EFFECTS ATTRIBUTABLE TO EROSION. 
 
 Many other facts are explained by the power of erosion and transport by 
 water. When, by studying faults in the interior of mines, we clearly see 
 that the beds no longer correspond, and that a part of the formation must 
 have been uplifted (Jig. 289) ; then, if the soil, a, i, c, is level on the surface, 
 
 Fig. 289. 
 
 Fig. 290. 
 
 we naturally ask what has become of the beds d and /, which ought to have 
 formed a hillock between b and c. It is clear these beds must have been 
 removed, which we may conceive was only by a posterior action of waters, 
 which carried away the debris, and perhaps spread them over the surface. 
 In the same way, when we see a vein form a projection, a dyke on the sur- 
 face of the soil (Jig. 203, page 119), we conceive that it could not have 
 formed in this manner, and that the uncovered part, must have been once 
 encased just as that is which is now covered ; the surrounding formation 
 has been uplifted then afterwards, at least along the whole actual height of 
 the projection. Something similar necessarily took place at points where 
 veins crop out on the surface, or are covered by moveable soil (fig. 290) ; it 
 is not probable that melted matter injected in the crack would be immedi- 
 ately arrested at the surface of the earth, and it is presumable that the soil 
 has been removed and subsequently covered by various clearings. We are 
 thus led to understand how so many basa'ltic masses now offer no trace of 
 scoria'ceous matter, neither in themselves nor in their vicinity. These im- 
 perfectly aggregated debris have been subsequently carried away by the 
 action of water, and perhaps it is the same with the scoria'ceous matter 
 which must have accompanied the appearance of trap. 
 
 The prodigious power exerted by waves, and the effects they have pro- 
 duced in our times, lead us to think, also, that all the rocks formed around 
 islands and reefs at a short distance from coasts, or the often fanciful groups 
 in the midst of the sea, are also the remnants of some great division caused 
 by water, as much in removable matters, easily disintegrated, as in masses 
 broken by earthquakes and different movements of the soil, and certain 
 parts of which have been afterwards removed, either by repeated shocks of 
 waves or sudden debacles. In this way we may explain the numerous 
 accidents in rocks which bound coasts, or are isolated in the midst of the 
 ocean, as in the sinkings of the chalk of Etretat (fig. 291), and the sec- 
 tions of porphyritic or granitic rocks in the Shetland islands (fig. 292). It 
 is conceived that straits, more or less extended, may have been formed 
 by the two combined actions of currents of water and rupture which the 
 soil might have undergone, by upheaval or subsidence, at determined 
 epochs. 
 
 From these observations, we see that many effects may be attributed to 
 the action of water which cannot be in any other way explained. We may 
 see denudations in the rnidst of mountains and valleys, recognise the ancient 
 sinkings which bordered seas at different ages, and hence appreciate their 
 limits, as well as all other circumstances connected with them. Reference 
 to the immediate action of water should be always carefully restricted to the 
 moveable or loose matters found on the surface of the globe ; for when 
 solid matters are in question, which water attacks too slowly, we are led to 
 
CLASSIFICATION OF FORMATIONS. 
 
 181 
 
 Fig-. 291. Fig. 292. 
 
 Examples of rocks cut and fashioned by water. 
 
 think that currents and waves cannot act effectively until the soil has been 
 previously prepared by the fissures or deteriorations caused in rocks by 
 movements of the earth. 
 
 We must not confound with divisions produced by water certain accidents 
 which may result from shrinking produced by metamorphism. This pro- 
 bably takes place in dolomites, which follow compact limestone in a great 
 many places, as in the Tyrol and in Cevennes. Masses of these matters 
 are frequently split and slashed in all directions on the surface, particularly 
 on the summits of mountains or on plateaux, very nearly in the same way 
 that calcareous deposits are cut by water. Now, the change from a simple 
 to a double carbonate, specifically heavier, requires contraction in masses 
 submitted to dolomisa'tion ; therefore, the latter must be split and cracked 
 in all directions, and the denudations they present are consequences of 
 these effects. 
 
 LESSON X. 
 
 Classification of Formations Different kinds of Stratification 
 Dip Strike Conformable Stratification Unconformable 
 Stratification False Stratification The form and habits of 
 an Minimal deducible from a single bone Relative ages of the 
 principal catastrophes of the Globe Systems of Upheaval 
 Classification of State of Europe at different epochs of forma- 
 tion Deluge Geogeny. 
 
 Classification of Formations. 
 
 1. As already mentioned, the several formations are divided into 
 two ciasses, namely : 
 
 1st. Massive, or igneous formations, which are produced by the 
 
 1. How are the several formations divided ? 
 10 
 
 What are the divisions ? 
 
182 CLASSIFICATION OF FORMATIONS. 
 
 action of fire, and are not stratified. The terms primitive and 
 transition have been applied to these formations, but, as they are 
 inexact, they are going out of use. 
 
 2d. Sedimentary formations, which are deposited by the action 
 of water, and are stratified. 
 
 2. MASSIVE, or IGNEOUS FORMATIONS escaped from the earth in 
 a state of fusion, and became solid by cooling, but without being 
 stratified. They are divided into two classes : 1st, those crystal- 
 line rocks which are not traceable to the crater of any volcano now 
 recognisable, such as granite, trachyte, &c. ; 2d, massive rocks of 
 a slightly crystalline structure, traceable to volcanoes, such as 
 modern and ancient lavas, and basa'ltic formations. 
 
 3. SEDIMENTARY FORMATIONS are arranged according to their 
 relative antiquity : they are divided into groups, composed of those 
 which appear to have been formed either at the same epoch or 
 during a geological period, during which the general condition of 
 the earth appears to have undergone no important change. These 
 formations are commonly divided into five groups, namely: 
 
 4. First. Primary stratified rocks, in which neither organic 
 remains, nor fragments of the most ancient rocks are found ; this 
 group includes gneiss, mica-schist, quartz,, transition limestone, 
 and argilla'ceous schist. 
 
 5. Second. The transition formations, which rest on the pri- 
 mary stratified rocks, and contain fossils of plants or animals, but 
 which appear to have been deposited prior to the creation of the 
 most perfect beings of either kingdom, and only contain the remains 
 of aquatic animals, which are all very different from those of our 
 times, such as tri'lobites (fig. 4, page 28). This group includes 
 fossili'ferous schists, transition limestones, &c. 
 
 6. Third. The secondary formations were deposited at periods 
 less remote than the transition, and consequently rest on beds of 
 the latter, or on .primary rocks ; but they go back to a time when 
 the state of the globe was very different from its present condition ; 
 very few mammals then existed ; ammonites are among the most 
 characteristic fossils of the secondary formation : 
 
 The secondary formations are subdivided into, 
 
 1st. The carboniferous, which includes old red sandstone, mountain lime- 
 stone, and coal : 
 
 2d. The sali'ferous, embracing new red sandstone muschelkalk, and 
 variegated marls, forming the tria'ssic system : 
 
 2. What are the divisions of the igneous formations ? 
 
 3. How are sedimentary formations arranged ? How are they divided ? 
 
 4. How are primary stratified rocks characterized ? What rocks are 
 included in this group? 
 
 5. On what do the transition formations rest ? How are they charac- 
 terized ? 
 
 6. On what do the secondary formations rest ? What are the most cha- 
 racteristic fossils of the secondary formations ? How are they subdivided ? 
 What are the divisions ? 
 
MEANS OF DISTINGUISHING FORMATIONS. 183 
 
 3d. The jura'ssic, embracing the lia'ssic, the o'olitc, and wealden groups : 
 4th. The creta'ceous, embracing the lower greensand, gault, upper green- 
 sand, chalk marl, chalk without, and chalk with flints. 
 
 7. Fourth. The tertiary formations, which, being more re- 
 cent, covered all the preceding formations ; they date from a period 
 when animals and plants belonging to all the great classes existed, 
 but still anterior to the creation of man : 
 
 The tertiaries are suhdix'ided into three groups ; 
 
 1st. The older tertiary or eocene, which embraces the London clay, bag- 
 shot sand, and Paris Basin. 
 
 2d. The middle tertiary, or miocene, which embraces the Coralline crag, 
 Red crag, the Molasse of Switzerland, &c. 
 
 3d. The newer tertiary, or Pliocene, which embraces Norwich crag, the 
 sub-Apennine beds, the Brown coal of Germany, &c., as well as the super- 
 ficial deposits, called Pleistocene, consisting of diluvium and alluvium. 
 
 8. Fifth. The modern formations, which are contemporaneous 
 with the existence of man on the earth, ;md are still being formed. 
 
 The subdivisions embrace : 
 
 1st. Peat-bogs, formed by the accumulation of the debris of certain plants. 
 
 2d. Coral formations, from the multiplication of polypa'ria as seen in the 
 coral islands of the Pacific. 
 
 3d. Concretionary formations, formed by calcareous and other matters, 
 found in solution in the waters of certain springs, &c. ; as travertin, stala'c- 
 tites, stala'gmites, &c. 
 
 4th. Formations from transport or drift ; as fluviatile, terrestrial, or marine 
 alluvions, dunes, &c. 
 
 5th. Humus, or vegetable earth, formed directly by the disintegration of 
 other formations, and their mixture with the products of decomposition of 
 plants and animals, spread in a layer of more or less thickness, on almost 
 every point of the surface of the earth. 
 
 9. All these deposits are superposed one on the other, in a con- 
 stant order; and if it were possible to make a sufficient section in 
 a part of the globe where they all exist together, we should find a 
 succession of twenty-seven stories, or layers, distinguishable by 
 their different characters. But each of the great deposits is divided 
 and subdivided into various layers, more or less distinct, composed 
 most frequently of arena'ceous substances, clay and limestone, of 
 different degrees of consistence, and in beds of varying thickness. 
 The assemblage of their alternate beds often forms successive layers, 
 several hundred yards thick. 
 
 10. It is evident, that if such sections existed in the crust of the 
 earth, we could see all the beds, and easily distinguish their rela- 
 
 7. From what period do the tertiary formations date ? What are the 
 divisions of the tertiaries ? 
 
 8. From what period do the modern formations date ? What formations 
 are embraced in the divisions of the modern formations ? How is humus 
 formed ? 
 
 9. What is the arrangement of the several deposits composing the crust 
 of the earth ? 
 
 10. Why is it difficult to distinguish the relative ages of deposits? 
 
184 RELATIVE AGES OF DEPOSITS. 
 
 live ages by their number in the order of succession ; the deepest 
 being the most ancient, and that forming the surface being the most 
 modern. It would then be sufficient, in sections of different depths 
 which would be found elsewhere, to count from above downwards, 
 to know always where we were, and even the variations that a 
 determinate bed might undergo in different places would offer no 
 difficulty to observation. But such is not the case ; the numerous 
 escarpments we meet, always present us with but a very small 
 portion of the series, sometimes in one part of its thickness, and 
 sometimes in another ; we never see the entire series ; and it is 
 only by combining the observations made in different places, that 
 we have been able to establish what we now know, at the same 
 time we discovered the particular circumstances of formation of 
 each deposit. 
 
 In consequence of the divisions of the whole, it is conceived, it might be- 
 come very difficult to distinguish them, and that in presence of an escarp- 
 ment one might frequently be unable, at first sight, to decide on the point in 
 the series to which it ought to be referred. Indeed, different beds of the 
 same nature which succeed each other in the series, are often very analogous, 
 the limestones of one story more or less resembling those of another ; and 
 the same is true of different deposits of sandstone and clay. It also happens 
 that the same deposit varies at different points : here it is a compact, and 
 there, an earthy limestone ; in another place the same limestone is found 
 mixed with sands, and, further on, it is nearly pure sand, &c. The injection 
 of crystalline matter adds to the embarrassment, by the modifications it 
 causes in the texture, and even in the nature of everything in its vicinity. 
 It is also conceived, that the fewer the beds superposed in the same place, 
 the greater the difficulties, and they are at a maximum when we meet an 
 isolated deposit, without knowing on what it rests, and not being able to 
 perceive anything it covers : this occurs in a great many countries. It 
 often happens, too, that one or more beds are entirely wanting in one locali- 
 ty, and then the deposits which should naturally separate them, being im- 
 mediately superposed, exposes the observer to attribute to the succeeding 
 beds an age very different from that which really belongs to them. 
 
 1 1 . To obviate this difficulty, we have observations on the con- 
 tinuity of beds, some of which we can follow from points where 
 they present certain characters, to others where they offer different 
 characters; from points where they are entirely isolated, to others 
 where we can see on what they rest, and what covers them, &c. 
 
 We have also observations on stratification and inclination of different 
 beds towards one point or the other, which enable us to infer that such a 
 species of deposit passes below or above another, found isolated or at a dis- 
 tance. Fragments and rolled flints may evidently indicate the priority of 
 deposits which contain them, to those from which they came, and thus fur- 
 nish a good means of distinction, when they are sufficiently characterized. 
 And the nature of organic remains has now become a very decided aid in 
 distinguishing different formations. 
 
 12. Different kinds of stratification. There are two kinds of 
 
 11. How are we enabled to judge of the relative ages of deposits ? 
 
 12. How many kinds of stratification are described ? What is observed 
 in inclined stratification ? 
 
DIFFERENT KINDS OF STRATIFICATION. 185 
 
 stratification : one horizontal (which is the natural stratification), 
 according to which all transported matters are deposited under 
 water ; the other more or less inclined, resulting from upheavals 
 which have taken place at different epochs. In the latter we dis- 
 tinguish the degree of inclination, or dip, which may be vertical, 
 and the point of the horizon towards which the beds dip. The 
 last part of the observation determines the direction of the crests of 
 the strata, or, as we say, the strike or direction of the strata, which 
 is always at right angles to the dip or direction of the inclination, 
 and which also indicates the direction of the movement by which 
 the effect was produced. But the first observation of horizontal, or 
 inclined strata, is not always sufficient ; it is frequently necessary 
 to distinguish the relative stratification of different deposits, which 
 is reduced to the concordance, or the discordance which may exist 
 between them. 
 
 13. The dip of strata is the point of the compass towards which 
 they slope, while the angle they form with the plane of the horizon 
 is called the angle of dip. The term dip refers to the inclination 
 of a stratum, and the term strike is used to express its direction. 
 Thus, strata may dip to the north at an angle of forty-five degrees ; 
 in this case, the strike, or line of bearing, must necessarily be east 
 and west, because the strike is always at right angles with the dip. 
 " Dip and strike may be aptly illustrated by a row of houses run- 
 ning east and west, the long ridge of the roof representing the 
 strike of the stratum of slates, which dip on one side to the north, 
 and on the other to the south." The angle formed by the roof 
 with the plane of the horizon would be the angle of dip. 
 
 14. Conformable stratification. When all the strata of a forma- 
 tion are parallel to each other, that is, when there is a concordance 
 between them, whatever may be their general position, horizontal 
 or inclined, convex or concave, they are said to be conformable 
 (Jigs. 293 to 296). 
 
 Fig-. 293. Fig-. 294. Fig-. 295. Fig-. 296. 
 
 Different, kinds of conformable stratification. 
 
 15. Unconformable stratification. When the strata of a forma- 
 tion are not parallel to each other, when there is a discordance 
 between them, as where horizontal strata come in contact with 
 
 13. What is meant by the dip of strata? What is the angle of dip? 
 What is meant by the term strike ? 
 
 14. What is meant by conformable stratification ? 
 
 15. What is meant by unconformable stratification ? Is it always of the 
 same character ? 
 
 16* 
 
186 
 
 UNCONFORMABLE STRATIFICATION. 
 
 inclined beds (Jig. 297), or where the relative inclination of beds 
 is different, as at a and b (Jig. 298), they are said to be uncon- 
 forrnable. Where a superior deposit, whether stratified or not, 
 rests on a section of the beds of an inferior deposit (Jig. 299), there 
 is a peculiar kind of unconformable stratification, sometimes called 
 transgressive stratification. There is another kind of unconform- 
 able stratification, where the beds are parallel ; this occurs where 
 a horizontal deposit, after having been furrowed in different ways 
 by water, is again entirely covered by a deposit of the same nature 
 which fills up all the excavations (Jig. 300). In this case the 
 strata are unconformable where they join end to end with beds on 
 the slope of ancient valleys. 
 
 Fig. 297. Fig. 298. 
 
 Fig. 299. 
 
 b 
 Fig. 300. 
 
 Examples of unconformable stratification. 
 
 16. To ascertain the relations in the stratification of two deposits, 
 it is necessary to pay great attention to the particular structure of 
 the beds, which in certain cases may lead us into error. For ex- 
 ample, seeing that the divisions of the bed , (fig. 301), dip to- 
 wards the left of the figure, we must not conclude that the strati- 
 fication is unconformable with the bed b ; this appearance results 
 altogether from the structure which the bed a owes to its rapid 
 formation under particular circumstances. (See page 138.) 
 Fig. 301. Fig. 302. 
 
 Examples of doubtful stratification. 
 
 17. Schistose substances often present many difficulties, in this 
 respect, because their divisions run in every direction, and some- 
 times the least apparent is the real stratification. For instance, we 
 might suppose, the deposit a, (fig* 302), rested conformably on the 
 deposit b, and that the mass c is an unconformable stratification, from 
 regarding the finest divisions of the schist as indicative of the stra- 
 
 16. What is meant by doubtful stratification? 
 
 17. What is false stratification? 
 
FALSE STRATIFICATION. 187 
 
 tification. But we might also consider the deposit a as unconform- 
 able, and the deposit' c as conformable, from regarding the parallel 
 joints., i to &, as those of stratification ; and it is also possible to 
 view both a and c as unconformable relatively to 6, by considering 
 the other joints as those of the strata. It may be often difficult to 
 decide ; nevertheless, in general, the schistose division is frequently 
 a structure which has perhaps a certain crystallization of mica'- 
 ceous matter ; and it is this character, therefore, among others, that 
 we must ordinarily select. Now, the joints of dislocation, for one 
 or the other division must have been thus produced, are splits 
 united arid well marked, often a little open, which are ordinarily 
 prolonged into several consecutive deposits, ,/ 
 while the joints of stratification are more un- jlU 
 dulated and more adherent. The most irregu- /// 
 lar undulations of true strata are often tra- 
 versed throughout by the schistose structure 
 (fig. 303), without alteration. This circum- 
 stance evidently shows that this structure is 
 an effect posterior to the contortion of beds, 
 and may be attributed to a metamorphism 
 more modern than their derangement. The 
 extraordinary divisions just mentioned, are Fig.3Q3. 
 
 sometimes termed false stratification. 
 
 18. Organic remains, which are very numerous in most sedi- 
 mentary deposits, also furnish a means of recognising strata. 
 There are some which are peculiar to certain deposits, and are 
 not found elsewhere, and which are therefore distinguished as 
 geo gnostic horizons. Thus, the Silurian or Devonian formations 
 are clearly recognised by the presence of the remains of a cer- 
 tain family of crusta'ceans, named trilobites (fig. 4, p. 28). The 
 Gry'phca arcua'ta (fig. 71, p. 55), is found in the has, and 
 only in it : the ex'ogy'ra vir'gula (fig. 109, p. 65), belongs to 
 the upper part of ,the jura'ssic formation ; baculites (fig. 130), and 
 turrili'tes (fig. 131, p. 72), begin and end in the creta'ceous period. 
 
 19. Although the remains of mollusks and small animals are 
 found entire, and therefore easily recognised, those of large mam- 
 mals, &c., often exist only in fragments ; and, without the neces- 
 sary knowledge, the family, genus, or species, could not be dis- 
 covered. But those well acquainted with comparative anatomy, 
 and the laws which govern in the organization of animals, can 
 deduce the form, and even the habits of an animal, often from a 
 single bone. 
 
 " Every organized being may be considered as an entire and perfect sys- 
 
 18. How do organic remains assist us in distinguishing the relative age 
 of strata ? 
 
 19. How is it that a portion of the fossil remains of an animal enable us 
 to recognise its class ? 
 
188 AN ANIMAL MAY BE KNOWN FROM ONE OF ITS BONES. 
 
 tern, of which all the different parts mutually correspond, and concur in the 
 same definitive action by a reciprocal re-action. No one part can undergo 
 a change without a corresponding change taking place in all the others ; and, 
 consequently, each part taken separately, indicates and gives the key to a 
 knowledge of all the rest. 
 
 " Thus, if the stomach of an animal is so organized as only to digest fresh 
 animal food, its jaws must also be so contrived as to devour such prey ; its 
 claws, to seize and tear it ; its teeth, to cut and divide it ; the whole struc- 
 ture of its locomotive organs, to pursue and obtain it ; its organs of sense, to 
 perceive it from afar ; and nature must have even placed in its brain the 
 necessary instinct to enable it to conceal itself, and to bring its victim within 
 its toils. Such will be the general conditions of a carni'vorous animal ; they 
 must inevitably be brought together in every species intended to be carni'- 
 vorous, for its race could not subsist without them ; but under these general 
 conditions there exist also special ones, relating to the size, the habits, and 
 the haunts of the prey, on which the animal is to exist; and from each one 
 of these special conditions there result certain modifications, in detail, of the 
 form re-quired by the general conditions ; so that not merely the class, but 
 the order, the genus, and even the species, will be found expressed by, and 
 deducible from, the structure of each part. 
 
 " In order, for example, that the jaws may be enabled to seize the prey, 
 there must be a certain shaped prominence for its articulation ; a certain 
 relation between the position of the resistance and that of the power, with 
 respect to that of the fulcrum ; a certain magnitude of the muscle that works 
 the jaw, requiring corresponding dimensions of the pit in which that muscle 
 is received, and of the convexity of the arch of bone beneath which it passes, 
 while this arch must also possess a certain amount of stiength, to enable it to 
 bear the strain of another muscle. 
 
 "That the animal may be enabled to carry off its prey, a certain degree 
 of strength is necessary in the muscles which support the head ; whence 
 results a peculiar structure in the vertebrae to which these muscles are at- 
 tached, and in the back of the skiill where they are inserted. 
 
 " That the teeth may be adapted to tear flesh, they must be sharp ; and 
 they must be more or less so, exactly according as they are likely to have 
 more or less flesh to tear, while their bases must be strong in proportion to 
 the quantity of bone, and the magnitude of the bones they have to break. 
 Every one of these circumstances will have its effect on the development of 
 all the parts which assist in moving the jaw. 
 
 " That the claws may be able to seize the prey, there must be a certain 
 amount of flexibility in the toes, and of strength in the nails ; and this 
 requires a peculiar form of the bones, and a corresponding distribution of the 
 muscles and tendons ; the fore-arm must possess a certain facility in turning ; 
 whence also result certain forms of the bones of which it is made up; and 
 these bones of the fore-arm, articulating to the humerus, cannot undergo 
 change without corresponding changes taking place in this latter bone. The 
 bones of the shoulder also require to have a certain degree of strength, when 
 the anterior extremities are to be used in seizing prey ; in this way again 
 other special forms become involved. The proper and free play of all these 
 parts requires certain proportions in all the muscles concerned in the mo- 
 tions of the fore-leg, and the impression of the muscles so proportioned will 
 determine still more definitely the structure of the bones. 
 
 " It is easy to perceive that similar conclusions might be drawn as to the 
 structure of the posterior extremities, which contribute to the rapidity of the 
 general movement of the body ; or of the vertebrae, which influence the 
 facility of those movements ; and also as to the structure of the bones of the 
 face, in their relation to the degree of development of the external senses. In 
 
RELATIVE AGES OF THE GLOBE'S CATASTROPHES. 189 
 
 a word, the structure of a tooth involves that of the socket in the shoulder- 
 bone, and of the nails, just as to use a mathematical, but very apt illustra- 
 tion the equation to a curve involves all the properties of the curve ; and 
 as the curve may be drawn when we know the root of the equation, so in 
 comparative anatomy, by making each property separately the base of in- 
 vestigations, one may deduce all the other properties. Thus the shoulder 
 bone, the articulation of the jaw, the thigh-bone, or any other bone, taken 
 separately, gives the structure of the tooth, or, conversely, from the tooth, 
 a knowledge of these peculiarities may be derived ; so that, taking any one 
 bone, he who is familiar with the laws of the animal economy, may repro- 
 duce the whole animal." Ansted. 
 RELATIVE AGES OF THE PRINCIPAL CATASTROPHES OF THE GLOBE. 
 
 From observations, it would seem that the dry land must have appeared 
 in successive portions, to cause on the surface all the variations of nature, 
 form, humidity, and dryness, the combination of which should procure for 
 man all the happiness designed for him by the Creator. The study of the 
 successive appearances of land is now one of the most beautiful points of 
 view in which geology can be presented ; we are indebted to M. Elie de 
 Beaumont for pointing out the course to follow, to establish the chronological 
 order of the principal catastrophes which happened in Europe, and around 
 which all facts of the same nature may be grouped. 
 
 As soon as we perceive some part of inclined sedimentary beds, we may 
 decide that they have been displaced from their ordinary position by up- 
 heaval. The period of this accident remains at first undetermined ; but if, 
 at the base of more or less elevated projections which these beds produce, we 
 find other sediments deposited in horizontal strata, 
 resting against the preceding (Jig. 304), it be- 
 comes evident that the upheaval of the first took 
 place after the formation of the second, which are 
 still found as they were when deposited from p- ^Q^ 
 
 water. We now have a term of comparison, and, 
 
 if we succeed in recognising the relative age of the horizontal deposit, we 
 also have an epoch of the catastrophe, relatively determined, which pro- 
 duced the uptilting of the other. These differences of stratification are 
 everywhere seen on the sides of mountains, and we then see that the several 
 sedimentary deposits, a, 6, c, are not all in the same position. In certain 
 places the stratum a, for example, is uptilted, and the stratum b is horizon- 
 tal ; in another, a and b are both uptilted, and c is horizontal ; in a third, a, 
 6, and c, are uptilted together, and another stratum, d, rests upon them. We 
 must infer, from these observations, that a first upheaval took place after the 
 formation of a, and before that of b; a second took place between the strata 
 6 and c, a third between c and d, &.C., and so on, chronologically, as far as 
 they have been observed. 
 
 Systems of upheaval. If the inclined position of sedimentary strata reveals 
 to us the existence of upheavals, the strike or direction of these beds, which 
 is nothing but the line produced by their swelling upwards or the crest or 
 ridge resulting from their rupture, shows us the course followed by the phe- 
 nomenon. Hence it follows we may take one fact for the other, as the basis 
 of observation, and that the different directions (strikes) of mountain chains, 
 are also indications of the different kinds of upheaval. In fact, it has been 
 long and perfectly established, on one hand, that the inclination of strata is 
 intimately connected with the direction of chains, excepting the perturba- 
 tions which result from crossings ; on the other hand, we now know that 
 the phenomenon of uptilting of a determinate number of beds extends as far 
 as the chain itself. It has also been ascertained, at least for Europe, that 
 parallel chains correspond, in general, in the epoch of upheaval ; that is, m 
 
190 SYSTEMS OF UPHEAVAL. 
 
 these chajns, strata of the same age are found every where uptilted, and that 
 the succeeding ones are horizontal. It follows from this circumstance that 
 an upheaval does not take place purely on a mathematical line, but on a 
 band of formations more or less wide, on which it is manifested by several 
 parallel ridges. The same line does not continue always from one end to 
 the other, but we find here and there high and low parts, and those which 
 are concealed by subsequent deposits ; therefore, it is the common line of 
 all the elevated ridges which must be taken for the general direction or 
 strike (The word strike is formed from the German streichen, to stretch, 
 to extend). 
 
 20. The assemblage of directions on the same line, and paral- 
 lel directions, form what is called a system of upheaval, which is 
 synonymous with the expressions, system of fractures, system of 
 uptilted tfeds, and even system of mountains, although in a more 
 restricted sense than in geography. To designate the different 
 systems, the names of places in which each system is particularly 
 developed have been borrowed ; we say, system of the Pyrenees, 
 system of the Western Alps, &c. 
 
 The great catastrophes which have successively opcurred on the surface 
 of the globe appear to have always taken place suddenly. At greater or less 
 distances from places where the stratification is unconformable, we often find 
 the same deposits in conformable stratification, and even joined to each 
 other by a gradual passage ; hence, it follows that deposition has not been 
 suspended, but the movement of the soil has been local over a more or less 
 considerable space of the terrestrial surface, and the interval during which 
 it took place must have been extremely short. This is clearly seen, for 
 example, at the period of the system of the Rhine, in which the vosgean 
 sandstone is found upheaved, without the bunter sandstein having partici- 
 pated in the action ; and, nevertheless, at a short distance the two arena'- 
 ccous deposits, where their stratification is conformable, are so joined to 
 each other, that it cannot be determined where one begins or the other ends. 
 The same is the case with the creta'ceous formations ; if their different 
 deposits are dislocated in a certain direction, they are conformable for great 
 extents, and they then pass from one to the other in such a manner that 
 they were for a long time confounded as a single formation. 
 
 Submerged and uncovered formations. Sedimentary beds found resting 
 horizontally on the sides of mountains, show that the sea beat against 
 escarpments by deposits upheaved in an anterior epoch ; hence the expres- 
 sion of the sea of this or that formation, as the creta'ceous sea, the jura'ssic 
 sea, &c., which indicate the waters beneath which each of these sedi. 
 mentary deposits was formed. When a deposit is wanting in a certain 
 extent of formation, we shonld infer the formation was then above the sea 
 of the epoch, and formed there a more or less elevated island or continent ; 
 thus, at the lime when the Parisian limestone was formed, a great part of 
 France, and indeed of Europe, must have been dry, as we scarcely see 
 traces of these deposits anywhere except in the neighbourhood of Paris or 
 Bordeaux. But it also happens that the deposits which we must regard 
 as having been dry at a certain time, were afterwards covered by marine 
 sediment, more modern than the preceding ; and hence we must conclude 
 that, although uncovered prior to the anterior formation, they must have 
 afterwards sunk to receive new deposits : such sinkings make certain catas- 
 trophes particularly remarkable. 
 
 20. What is meant by "system of upheaval"? What is meant by cre- 
 ta'ceous sea? How are the several systems of upheaval classed ? 
 
EPOCHS OF EUROPEAN FORMATIONS. 101 
 
 The several systems of upheaval have been classed according to their 
 direction, and the epochs in which they occurred. The following table 
 exhibits the supposed epochs of the European upheavals. 
 
 1st, Lpheaval, or system of Hnndsruck, between the cambrian and silurian formations. 
 
 2d, or system of Ballons, between the silurian and coal formations. 
 
 3d, or system of the North of England, between the coal and penine formations. 
 
 4th, or system of Hainault, between the penine and vosgean formations. 
 
 5th, or system of the Rhine, between the vosgean and trias formations. 
 
 6th, or system of Thuringerwald, between the trias and jnra'ssic formations. 
 
 7th, or system of Cote-d'Or, between the jura'ssic and greensand formations. 
 
 8th, or system of Mont-Viso, between the two creta'ceous formations. 
 
 9th, ' or system of the Pyrenees, between the upper chalk and Parisian limestone " 
 10th, ' or system of Corsica, between the Parisian limestone and molasse formations, 
 llth, ' or system of the Western Alps, bet. the mnlasse and siibapennine formations. 
 12th, ' or system of the principal Alps, bet. the subapennine and diluvium. 
 13lh, ' or system of Tenare, between the diluvium and perhaps some modern alluvions. 
 
 Since in Europe the different great chains of the same direction, which 
 are found on the same line or on parallel lines, belong to the same epoch of 
 upheaval, there is room to suppose, as nothing indicates limits to the phe- 
 nomena which gave rise to them, that the same effects were continued far 
 beyond the countries whose geological structure is known ; hence it follows, 
 that wherever we find parallelism in the chains, we should be led to believe 
 also that the formations were contemporaneous. It is at least interesting to 
 examine, under this point of view, the principal chains we are acquainted 
 with. 
 
 The direction of the Pyrenees extends from the Alleghanies, in North 
 America, to the peninsula of India, through the Carpathian mountains, a 
 part of Caucasus, the mountains of Persia, from Erivan to the Persian Gulf, 
 and through the Ghauts, which determine the position of the coast of Mala- 
 bar. To the south of this line of direction several parallel ridges are also 
 represented : those which go from Cape Ortegal, in Asturias, to Cape Creux, 
 in Catalonia; the small chain of Granada, which ends in Cape de Gatte ; 
 the mountains which bound the desert of Sahara on the north, cutting the 
 direction of Atlas ; finally, the Apennines, the Julian Alps, the mountains 
 of Croatia, of Romelia, and those of the Morea. 
 
 The system of Ballons, so near to that of the Pyrenees, appears to be 
 represented also in the Alleghanies : it is to be observed on the coast of 
 Brittany, and will no doubt be found in several of the groups just mentioned, 
 when careful study enables us to distinguish it from the neighbouring 
 system. 
 
 The direction of the Western Alps is remarked from the empire of Mo- 
 rocco to Nova Zembla, passing through the eastern coast of Spain, the south 
 of France, and a great part of the peninsula of Scandinavia. It is recognised 
 in the Cordillera of Brazil, from Cape St. Roque to Montevideo. Parallel to 
 this direction the same system is seen in the kingdom of Tunis, in Sicily, 
 the point of Italy, and in Asia Minor. All the shore of the ancient conti- 
 nent, from North Cape, in Lapland, to Cape Blanco, in Africa, is parallel to 
 the direction of this system. 
 
 The principal Alps form part of a system of direction of great extent. 
 From the chains of Spain and those of Atlas, in the northern part of Africa, 
 we find parallel chains which extend to theChina sea. On this line of direction 
 we find, starting from Sicily and Italy, the chains of Olympus, in Greece, 
 the Balkan, Taurus, the central chain of Caucasus, crowned by Elbrouz, 
 between the Black and Caspian seas, the long series of mountains which 
 extend through Persia and Cabool, comprehending Paropamisus, Hindou- 
 koh, &c. ; finally, Himalaya, the highest mountain in the world. 
 
 STATE OF EUROPE AT DIFFERENT EPOCHS OF FORMATION. 
 
 From what has been stated, we are led to infer that the surface 
 
192 SILURIAN AND DEVONIAN EPOCHS. 
 
 of the globe, so often disturbed, must have presented great varia- 
 tions in the relative extent of land and sea, and successively passed 
 through many different shapes, to reach its present state. But, 
 even in Europe, the only part of the world in relation to which 
 positive information has been obtained, it is very difficult to say 
 what may have been its condition in the most ancient epochs. 
 The reason of this is, that having for a long time confounded, under 
 the name of transition formation, deposits of very different epochs, 
 we are not now able to distinguish, with sufficient clearness 
 throughout, the limits of different formations comprised in- it. Nor 
 do w r e know, and this is a great obstacle to tracing the continents 
 of the ancient world, what parts were successively sunk at each 
 catastrophe, and the extent of which we can only know from induc- 
 tion. It was not until after the appearance of the jura'ssic forma- 
 tion, the limits of which are clearly marked, that we are able to 
 distinguish, with precision, the shape and extent of lands in the 
 midst of seas in which these deposits were formed. 
 
 By the term epoch of this or that formation, we understand the 
 period of time during "which the formation was produced beneath 
 the sea, around the upheaved deposits of the preceding epoch. 
 For example, the jura'ssic epoch indicates the time during which 
 the deposits of the Jura were formed in the seas where the 
 upheaved deposits of the trias and all that preceded were traced. 
 The term, sea of such an epoch, as jura'ssic sea, creta'ceous sea, 
 &c., is often used in the same sense. 
 
 Silurian and Devonian epoch. At the time when the Silurian 
 and Devonian systems were formed in the midst of seas, it is evi- 
 dent there were different portions of land in Europe uncovered, 
 which resulted as much from the upheaval of the Hundsruck as 
 from previous catastrophes : we have seen those of considerable 
 extent which entirely escaped these deposits, and which, in conse- 
 quence, must have been raised above the waters in which they were 
 formed. In France, there was at least one island, of the Cambrian 
 formation, near the gulf of St. Malo, on a part of Brittany and of Nor- 
 mandy; the great granitic plateau, w r hich comprises Limousin, Au- 
 vergne, &c., where the upheaval of the Hundsruck was manifest by 
 the direction of certain uptilted beds of gneiss, and by the anfracluosi- 
 ties in which the coal formation was subsequently deposited, must 
 have been, at that time, above water, and, perhaps joined, at the 
 south, to the ancient group which preceded the Pyrenees. The 
 mountains of Maures also existed, and, perhaps, a part of the 
 formations comprised between Toulon and Inspruck, in a south- 
 west and north-east direction. Some parts of the 'centre of Vosges, 
 and of the Black Forest, Eiffel, the Hundsruck, where the first 
 upheaval is clearly indicated, and Ardennes, were necessarily 
 above water, as well as the county of Nassau, the Hartz, all the 
 centre of Germany, including Saxony, Bohemia, and Moravia. 
 The same i? true of Scandinavia, and a part of the British islands. 
 
COAL EPOCH. 193 
 
 From this moment lands were covered with vegetation, in arbo- 
 rescent ferns, equisita'cese, &c., sufficiently abundant to form the 
 masses of anthracite found in the Devonian formation. The seas 
 were then inhabited by trilobites, orthoce'ratites, orthis, productus, 
 different kinds of terebra'tula and several species of polypa'ria, 
 of the same genus as those found in madreporic reefs, which, as 
 well as the tree-ferns, indicate a climate analogous to that of the 
 present tropics. All these circumstances show that heat was not, 
 in that epoch, distributed over the surface of the globe as it now is. 
 Without doubt, the increase of temperature, from the surface to the 
 interior, was more rapid ; all springs were warm ; and, according 
 to M. Elie de Beaumont, the fogs, which were the result, hinder- 
 ing radiation, in the absence of the sun, everywhere tempered the 
 rigour of winter, and thereby augmented the mean temperature 
 of the seasons. 
 
 Coal epoch. The upheaval of the Ballons, in bringing " to day" 
 the Silurian and Devonian deposits, no doubt, increased the extent 
 of lands, and more or less changed their configuration. Vegeta- 
 tion must have been prodigiously developed, at that time, and over 
 vast surfaces ; which is proved by the enormous mass of coal 
 formed, and the manner in which the deposits are piled up. On 
 one hand, the carboni'ferous limestone, and the different marine 
 beds found in the midst of the sandstone of the coal formation itself, 
 seem to indicate at first a deep sea, and perhaps afterwards an 
 immense maritime marsh, which extended from Ardennes and the 
 Hartz to the ancient mountains of the British islands. On the 
 other hand, the numerous coal basins known to exist in the surface 
 of France and central Germany, clearly show there were extensive 
 lands on which marshes were found, here and there, in which were 
 formed, just as pcat-bogs are in our times, all the coal deposits 
 we have discovered. 
 
 The ancient and uncovered formations, which constitute Brittany 
 and the central plateau of France, clearly indicate high land, on 
 which are found the lakes of Bayeux, duimper, Laval, and Vouvant, 
 placed perhaps in the anfractuosities caused by upheaval of the 
 ballons ; then those of Buro-undy, Limousin, Auvergne, Forez, &c., 
 situated on a direction parallel to the elevation of the Hundsruck. 
 This land, the limits of which cannot be fixed, extended at least to 
 a peninsula towards Strasburg. 
 
 To the east of this land, and perhaps united to it, there is another, 
 which was evidently uncovered, because there is nothing of the 
 penine formation deposited on it. The latter probably extended 
 over the space no\v occupied by Inspruck, Milan, Briancon, 
 Genes, Nice, Toulon, and to the island of Corsica. Towards Toulon 
 are the marshes in which was formed the coal now found in that 
 part of France. 
 
 Lands also evidently existed over the space occupied by Bohe- 
 
 17 
 
194 COAL EPOCH. 
 
 mia and Saxony, with several coal lakes on their surface ; the coal 
 deposits of Moravia and Galicia seem to show their extension 
 towards those countries. There was one island, at least, between 
 Cologne and Francfort, presenting in its southern part the great 
 coal basin of the country of Treves, and uniting, at the north, with 
 the ancient formation of the Hartz. Dry land also existed in the 
 peninsula of Scandinavia, where nothing has been deposited since 
 the Silurian formations ; but it seems to have been sterile, and 
 without swamps, for it affords no trace of coal. 
 
 We are entirely ignorant of what existed where the great cities 
 now stand; but the absence of carboniferous limestone, out of Bel- 
 gium and England, may lead us to think that a great portion of 
 western Europe w.as then uncovered, and perhaps presented coal^ 
 lakes which subsequent catastrophes have sunk beneath the seas. 
 
 A part of the land just mentioned has always remained unco- 
 vered to the present time, or has been even upheaved more and 
 more by various subsequent catastrophes, as Brittany and the cen- 
 tral plateau of France. At certain points, in fact, coal deposits 
 have been pushed upwards to a great height, as the plateau of 
 Santa Fe de Bogota, and in the Cordillera of Huarochiri, where 
 some are found from 2700 to 4000 yards above the sea. In other 
 places, on the contrary, it is evident the formations have sunk, to 
 be covered by more modem deposits, through which the coal is 
 sought in the depth, as at Anzin, under the chalk, in Vosges, under 
 the red sandstone, in Cevennes, under the jura'ssic limestone, &c., 
 and, in general, on the borders of new formations exposed by sub- 
 sequent catastrophes. Without doubt, there is some deeply-buried, 
 and for ever lost to us, either under different sediments, or under 
 water, as at Whitehaven, in England, where the mine extends 
 more than a quarter of a league from the shore, and a hundred 
 yards beneath the bottom of the sea. 
 
 The vegetation of this epoch, favoured, no doubt, by the insular 
 form of the land, as it now is in all islands, consisted of lycopodia'- 
 ceas, equisita'cese, ferns, &c., of arborescent species, the analogues 
 of which nre no longer found except within the tropics, with com-, 
 fers resembling the araucaria. The mass of coal was formed of 
 their debris, with cellular cryptoga'mia, which then grew under 
 water, as now, in peat-marshes, and under a still more favourable 
 temperature for their development. 
 
 The seas of this epoch had lost their tri'lobites ; but contained, 
 in great abundance, spi'rifers, productus, orthoceras of particular 
 species, different ce'phalopods, analogous to the nautilus and argo- 
 naut, and various other shells. The encri'nites were so extensively 
 multiplied that their debris constitute, almost of themselves, certain 
 varieties of Flemish and Belgian marble. Sauroid fishes, of great 
 size, and of especially vigorous organization, then existed ; and 
 the family of sharks, still feeble, presented cestra'cions and hybo- 
 dons (Jigs. 52, 53, p. 45). 
 
THE PENEAN AND VOSGEAN EPOCHS. 195 
 
 The fresh waters which fed the coal marshes contained, as it 
 appears, few conchi'ferous mollusks ; the debris, which are rarely 
 found, resemble anodonta and unio'. Fishes were numerous, in 
 some localities ; they belonged to the. genera palioni'scus (fig* 56, 
 p. 48), and ambly'pterus, living, without doubt, in the rivulets 
 which meandered at the bottom of abrupt fractures of the ancient 
 formation. 
 
 Penine epoch. The disturbance caused by the upheaval of 
 the north of England, appears to have exerted more influence on 
 the surface, of the then uncovered lands, than on their extent and 
 form. Only the bottom of the sea, where the coal-beds of Eng- 
 land and Belgium were formed, was elevated in part to escape, 
 like all France, to the penine formation. On the other hand, 
 a small corner of the south-west of Vosges must have sunk 
 under water, to receive the red sandstones which there cover 
 the coal formation. Further, in Mansfield the presence of the 
 penine formation, which is there developed on a great scale with 
 its shell-limestones, demonstrate the submersion of the country 
 beneath sea-water. It was also beneath the sea, in the county of 
 York, that magnesian limestone was deposited, which there repre- 
 sents the whole formation of this epoch. 
 
 Very little is known of the terrestrial flora of that time, for we 
 find little, save the algae in the bitu'minous schists of Mansfield, 
 and some sili'cified trunks of co'nifers in the sandstone. Deposits 
 of coal suddenly ceased to form, and it seems from that time there 
 were neither ponds nor rivulets on the lands ; nevertheless, there 
 were still divers fishes of the genus palioni'scus, which lived per- 
 haps as well in salt as in fresh water. The land was for the first 
 time inhabited by saurian reptiles resembling the iguana and moni- 
 tor, the remains of which are found in the cuprous schists. The 
 seas beneath which all these deposits were formed, contained the 
 same genera, often the same species of mollusks and radiata as 
 those in which the carboni'ferous deposits were formed. 
 
 Vosgean epoch. The system of Hainault, in dislocating the 
 coal formation and ridging the surface of the land, had little in- 
 fluence on its form. In the Vosges some of the points where the 
 red sandstone was deposited were elevated, around Saint-Die, 
 Schelestadt, Montbelliard, and escaped the succeeding formations ; 
 while all the rest of the chain, which had escaped the deposits of 
 the red sandstone, and consequently found elevated at this epoch, 
 must have been sunk now to receive the vosgean sandstone : the 
 same has taken place in the Black Forest. 
 
 Such was the state of things in this modification, that animals 
 could not have lived on this part of the earth, and that plants, if 
 any then existed on the surrounding soil, could not have been car- 
 ried under the waters except in very small numbers. 
 
 The trias epoch. After the system of the Rhine, subsequent to 
 
196 THE TRIAS AND JURASSIC EPOCHS. 
 
 which the vosgean sandstone was upheaved, Vpsges and the Black 
 Forest underwent a little change in shape ; but other lands in 
 Europe have undergone scarcely any modification. We observe 
 only a secondary elevation of the central plateau of France by the 
 porphyroid granites of Lozere, by the hills which edge the coal 
 formation from Fins to Mauriac. Subsidences occurred, on the 
 other hand, in Bourbonnais and Rouergue, as well as in lands be- 
 tween Toulon and Mice. Vegetation then underwent great modifi- 
 cations ; the ferns and equisita'cerc of great height had considera- 
 bly diminished, and coni'fers, on the contrary, became more 
 numerous : plants analogous to za'mia, and perhaps to cy'cas 
 (Jigs. 305, 306),- then formed an important part of the flora of 
 Europe, being a prelude to the immense development they took in 
 the succeeding epoch. 
 
 Fig. 305. Za'mia pungens. Fig. 30fi. Cy'cas revoluta. 
 
 In this epoch new saurians appeared, and traces of birds, which 
 had not appeared in preceding epochs, are recognised. It was at this 
 period also that those creatures existed, whatever they were, whose 
 tracks are found imprinted on bunter sandstein, freshly lifted above 
 water. Mr. Owen, who considers them enormous batrachians, 
 supposes them to have been of the form represented (Jig. 307). 
 
 The jum'ssic epoch. At the time of the elevation of Thurin- 
 gerwald the tria'ssic formation, which had just been deposited 
 beneath the sea, was upheaved at different points; some patches 
 of banter sandstein were added around the central plateau of 
 France, between Moulins and La Chatre, between Brives and 
 Tulle, in the environs of Rodez, of Saint-Affrique and of Lodeve. 
 
THE JURA'SSIC EPOCH. 197 
 
 Fig. 307. Labyrinthodon pachygnatus. (Owen.) 
 
 The island of Var was increased from these sandstones and con- 
 ch ylian limestone ; the Vosges and Black Forest were also con- 
 siderably augmented, the one to the west, in Lorraine, the other to 
 the east, extending into Germany, and uniting various islands 
 which had been separate till then. The same was the case with 
 different islets which already marked the place of the British 
 islands, and were then united to a continuous land by tria'ssic depo- 
 sits upheaved between them, and with them. But at the same 
 time that the new lands were raised above water, there were great 
 subsidences in those which previously existed. The land which 
 extended from Cherbourg to Perpignan, was then divided towards 
 Poictiers, forming a strait, now occupied by the jura'ssic deposits ; 
 it was variously divided on its borders, and almost cut again towards 
 Rodcz. That which extended from Nice towards Inspruck was 
 entirely sunk, to receive the new deposit which covers it. If per- 
 chance there existed, at the period of the coal, some portions of 
 land where Paris, London, &c., now are, everything leads to the 
 belief that they then disappeared, for the jura'ssic formation 
 appears to be prolonged everywhere beneath the soil which serves 
 them as a base. 
 
 All the data on the state of western Europe, at the period of 
 which we speak, are furnished by the presence and disposition of 
 the jura'ssic deposits. Developed on a vast scale, and upheaved 
 later from the bosom of the waters, they clearly show what was 
 then the configuration of the lands around which they were formed 
 under the sea. 
 
 The ocean of the jura'ssic epoch also had its peculiar characters. 
 It was inhabited by saurians, eminently swimmers, the ich'thyo- 
 sau'rus and plei'siosau'rus, whose paws, in form of paddles, remind 
 us of those of the chelonians of the present day ; these voracious 
 animals, all aquatic, took the place of the sauroid fishes of the car- 
 boni'ferous group, which had now disappeared. At the same 
 period lived those flying saurians, called pteroda'ctyls, which 
 peopled the air and completed the series of singular creatures of an 
 ancient creation, now entirely annihilated, the exterior forms of 
 which Dr. Buckland has attempted to paint from the skeleton (fig. 
 308). 
 
 These seas had lost the productus, and spirifers had almost dis- 
 17* 
 
THE JURA'SSIC EPOCH. 
 
 Fig. 308. Restoration of the saurians of the jura'ssic epoch. 
 
 appeared. The numerous terebra'tulee, which lived in this epoch, 
 belonged to species entirely different from those seen in the pre- 
 ceding seas ; but there was found a great number of mollusks with 
 chambered shells, in general called ammonites, the race of which, 
 as yet little developed, had begun to appear in the seas of the trias ; 
 there existed bele'mnites, the remains of which, until then unknown, 
 are numerous from the lias to the chalk : and the gry'phea arena' ta 
 multiplied there for a moment, to disappear afterwards, when the 
 has was formed, and to give place to other species of the same 
 genus. 
 
 As at present, coral reefs were formed in those seas, remains of 
 which are found, showing a mean temperature, analogous to that 
 of our intertropic seas. 
 
 On the land, fresh-water lakes without doubt supported palu'di- 
 na3, and fresh-water streams carried helices, remains of which are 
 now found in the Portland group. 
 
 There must have existed also, on land, several species of insects, 
 which served to feed the pteroda'ctyls, the remains of which seem 
 to show they were coleoptera and neuroptera, resembling the bu- 
 prestes and libe'llulse. Small marsupial mammals, analogous to 
 opossums, were met there, a skeleton of which was found in the 
 beds of Stonesfield. But these creatures seem to have been in 
 small numbers, if w r e judge from the few remains that have been 
 as yet found, and no one of the great animals which characterize 
 the parisian epoch has been found with them. 
 
CKETA'CEOUS EPOCH. HMJ 
 
 The flora was not the same as that which furnished so many 
 remains to the coal formation ; the lycopodia'ceae, and the gigantic 
 ferns had disappeared ; and it seems that many new species had 
 been created after the penine and tria'ssic epochs. Then the 
 cyca'dese and co'nifers considerably exceeded all other families ; 
 and probably some palms were already in existence, the fruits of 
 which are found in the lias. Also the carbona'ceous combustible, 
 formed in this epoch, is very different from that of the great coal 
 formation. They were at the same time much less abundant, 
 which indicates a great difference in the extent of lands. 
 
 Creta'ceous epoch. After the system of upheaval of Cote-d'Or, 
 which elevated a part of the jura'ssic deposits above the sea, the 
 form and disposition of continents were considerably changed. 
 The inferior limits of the chalk mark the shape of lands which 
 then existed, and determine the extent of the seas of the epoch. 
 
 The three islands of the preceding epoch were now united, but 
 without any change of shape. Brussels, which was inland, was 
 now found on the coast ; Arras, Dunkirk, Maastricht, Wesel, Bres- 
 law, and Vienna, were sunk under water. A lake was formed 
 between Dresden, Brunna, and Prague ; a strait was found in the 
 place of Perpignan and Carcasonne ; and, what existed previously 
 to the Pyrenees, was in part submerged. 
 
 By compensation, the Vosges, washed by the sea in preceding 
 ages, was then found in the middle of the continent which joined 
 the central island of France. The space of sea which separated 
 them was filled up. Langres, Nevers, Lyons, Toulouse, and Ox- 
 ford, were on terra fir ma, and an isthmus was formed about Poic- 
 tiers, to join the great island that existed to the west. A shore 
 extended from the environs of Craco'via, to about Perpignan, by 
 Ratisbonne, the position of which was not changed, and to Zurich 
 and Lyons. An immense gulf was formed between Brussels and 
 Oxford, extending to Poictiers. 
 
 Between Salzbourg and Avignon, a new island was formed, 
 which marked the future site of the Alps : Brian^on, Turin, Trente, 
 and Inspruck, might have been already placed there ; but Switzer- 
 land was then a channel which separated this island from terra 
 firma. The island of Toulon was at the time limited, and some 
 small islands marked the environs of Marseilles. 
 
 Little change, however, had taken place in living creatures. At 
 the same time divers species of ferns and cyca'dese vegetated on 
 the soil ; co'nifers, especially, became more and more abundant, and 
 gave origin to masses of lignite found at the base of the chalky 
 formations ; but there were few terrestrial mammals, for no remains 
 of them are found in the chalk, although they were met with in 
 jura'ssic deposits. There existed, however, divers ceta'cese, such 
 as lamantins and dolphins, some of which had already appeared in 
 the jura'ssic seas. Reptiles were, among the animals capable of 
 
200 PARISIAN EPOCH. 
 
 living on the earth, still the most elevated creatures of the creation. 
 Aquatic and terrestrial species were very numerous ; among them 
 were the iguanodon, the megalosau'rus, and divers crocodiles. 
 Fluviatile tortoises, fishes, and mollusks of fresh water, lived on the 
 borders of lakes, or in their waters. The seas fed ba'culites and 
 turriiites, of whose anterior existence there is no trace, and which, 
 towards the end of the epoch, disappeared at the same time with 
 all mollusks having peculiar chambered shells. Here and there 
 true sharks existed, and have been continued to the present time, 
 although their dimensions are considerably diminished. 
 
 Parisian epoch. The upheaval of Mount Viso, and later, that 
 which gave birth to the Pyrenees, to the Apennines, and all the 
 parallel chains we have cited, prodigiously changed the geographi- 
 cal constitution previously established. The last, especially, pro- 
 duced one of the greatest convulsions Europe has experienced : 
 everything was shaken by it, and the greatest part of what was 
 then under water, was elevated above it, to form an immense con- 
 tinent. This proves the little extension of the parisian sediments 
 then formed, and which are found concentrated, one part in Bel- 
 gium, Artois, Picardy, Isle of France, Normandy, and the opposite 
 coasts of England ; and the other, in the environs of Bordeaux : 
 very few traces are found elsewhere. Hence it follows, that the 
 seas of this formation did not penetrate far into this continent, 
 although they covered the two capitals of the world ; of the vast 
 ocean of preceding ages there only remained a part of the gulf 
 already limited, about Cambridge, Oxford, Exeter, Cherbourg, 
 Angers and Poictiers, which was then narrowed in many places, 
 and widened elsewhere at the expense of the ancient peninsula of 
 Brussels ; it probably communicated with some remains of the 
 North Sea. In the middle were two islands of chalk, the Wealds, 
 of England, and the country of Bray, in France. Another portion 
 of the gulf also remained between Bordeaux and Dax. 
 
 The fauna of the land, at the parisian epoch, was very different 
 from what it had been in preceding epochs. The gigantic sau- 
 rians had disappeared, but there remained great fresh-water cro- 
 codiles, marine and lacu'strine chelonians, and the earth was 
 inhabited by mammals. The last were then pach'yderms, analogous 
 to tapirs, as the anoplothe'rium and paleothe'rium, which must 
 have been nearly of the form represented (fig. 309) ; they lived 
 at the same time with some carni'vora of the genus dog, &c. Belem- 
 nites, and all similarly chambered shells, had disappeared from 
 the seas ; the nautilus only remained, and it lived with the cere'- 
 thium giga'nteum (fig. 148, p. 80), and a multitude of species of 
 rnollusk, more or less resembling those of existing seas. 
 
 At this age of our planet, the flora of Europe was still modified ; 
 the cyca'dea? had disappeared, and the co'nifers, presenting still 
 new species, to which were joined the dicotyledons, were found, 
 
PARISIAN EPOCH. MQLA6SE. 
 
 201 
 
 a b d 
 
 Fig. 309. Fauna of the epoch of the parisian formation. 
 ileothe'rinin ma<rnnm. c. Anoplothe'rium commune. 
 
 a Paleothe'rium magnum 
 b Paleothe'rium minus. 
 
 d Crocodile. 
 
 with palms, to the centre of Europe. The last, which are not jiow 
 found closer than Africa, at the nearest point, evidently indicates a 
 mean temperature, higher than that we now enjoy, which must have 
 been about 72, the present mean temperature of lower Egypt. 
 This circumstance may be attributed to the fact that the increase 
 of internal heat was greater than at present, and that the fogs, by 
 diminishing radiation, rendered the winters less rigorous. 
 
 Water-courses necpssarily must have existed on the continent, 
 and may account for deposits of lignite, and the remains of fresh- 
 water mollusks, being found in place in the midst of marine depo- 
 sits. We are especially led to suppose that one of these water- 
 courses, emptying about Laon and carrying lacu'strine deposits 
 from Soissonais, and another, somewhere between Exeter and 
 Oxford, formed the deposits of the Isle of Wight, at the south- 
 west of the Wealds. Around Paris, some parts of the sea must 
 have been separated from the rest, at a certain time, and 
 converted into a fresh-water lake in which the gypsum was 
 formed. 
 
 Epoch of the molasse. It was after the system of Corsica that 
 the molasse Avas formed, and, in such a manner, that it is 
 generally deposited where the Parisian limestone is entirely 
 w r anting. It follows that lands which were then elevated above 
 the waters must have necessarily sunk, often to great depths, to 
 receive this new formation, which is sometimes extremely thick; 
 consequently, great modifications of the continent of the preceding 
 epoch again took place. Partial subsidences must have occurred 
 
202 SUBAPENNINE EPOCH. 
 
 in many parts of Touraine, of Guienne, of Gascony, Languedoc, 
 Provence, Dauphiny, and also in all Switzerland, &c. ; lakes 
 were formed, often extensive, sometimes isolated, and sometimes 
 communicating with the sea ; and it is this which indicates the 
 contemporaneous deposits, some of which are fluviatile, and others 
 marine. In opposition, more or less considerable upheavals took 
 place at the same time in many parts of the northern gulf, in Bel- 
 gium, in Picardy, in the isle of France, and all the coast of Eng- 
 land. The marine limestone, laid bare, escaped in all this extent 
 the succeeding deposits, and the sites of London and Paris were 
 brought to light, although surrounded by water in which the mo- 
 lasse was deposited ; it was the same in the gulf of Bordeaux, 
 where all the northern part of the Parisian formation was up- 
 heaved, and escaped the deposit of the molasse, which is found in 
 all the rest of the present basin which was from that time sub- 
 merged. 
 
 This epoch was accompanied by a new change in the creatures 
 which lived on the surface of the soil; and from that moment, 
 besides some new species of paleothe'rium, mastodons, and the 
 dinotherium gigdnteum, appeared in Europe (the last nearly of 
 the form represented, Jig. 810), as well as the rhinoceros, hippo- 
 po'tamus, monkeys, and many rodents, as castors, squirrels, &c. 
 The flora was principally composed of coni'fers, w T ith dicoty'ledons, 
 which, however, had not attained, in all probability, the develop- 
 ment they acquired in the succeeding epoch. There still existed 
 palms, the remains of which are found in deposits of lignite, and 
 particularly in those of Liblar, near Cologne, as well as in the 
 plaster-works of Aix. 
 
 Fig. 310. Restoration of the Dinothe'rium giga'ntcum. 
 
 Subapennine epoch. The upheaval of the western Alps caused 
 a new disturbance. Not only the soil comprised between Con- 
 stance and Marseilles, rendered mountainous by preceding events, 
 suddenly assumed a considerable height, and a great part of the 
 relief it now presents, but still the movement extended over all 
 Europe. The greatest part of the Anglo-French gulf was filled 
 by an elevation, which brought to day" all that is referred to the 
 
EPOCH OF DILUVIUM. 203 
 
 molasse. It was the same in Guienne, in Languedoc, in Provence, 
 in Piedmont and Switzerland ; and the form of the seas was once 
 again changed. But, in time, great Jakes were formed in the inte- 
 rior of the lands : one, from Dijon to near the Isere ; another, in the 
 southern part of Alsace ; and a third, in Provence, from Sisteron 
 to the borders of the Durance. 
 
 At that time all the carni'vora appeared of the genera ursus, 
 hyena, felis, cams, $*c., which inhabited caverns ; their remains 
 are not found in the Parisian formation ; their species disappeared, 
 not only from the European continent, but from the face of the 
 globe, in the next epoch. There also appeared several new 
 rodents, horses, ruminants, and probably the gigantic edentate ani- 
 mal, with slow and heavy gait, the megathe'rium (Jig. 178, p. 92), 
 whose head and whole aspect were similar to the sloths, although 
 its size was that of the largest rhinoceros, and its body must have 
 been covered by a bony cuirass like the armadillo. 
 
 Epoch of diluvium. At this time Europe took its present form, 
 and its relief was definitely fixed. The upheaval of the principal 
 Alps, in forming all the chains which extend to Austria, in elevating 
 likewise some portions of the western Alps, also raised up the soil 
 in a great part of Europe, and especially caused the division of the 
 waters between the ocean and the Mediterranean. The effects pro- 
 duced show that enormous currents of water were established in all 
 directions, which furrowed all the deposits then uncovered ; but the 
 volume of waters furnished by lakes, previously formed in the interior 
 of lands, whose barriers were no doubt broken in the new catastrophe 
 of upheaval, was in relation to the vastness of the result produced ; 
 it must have been prodigiously increased by some circumstances, 
 attributable, perhaps, to the sudden melting of the snows, and gla- 
 ciers then accumulated on the western Alps. The currents which 
 were formed, in furrowing the surface of lands, carried their debris 
 in all directions ; hence the alluvions of the valley of the Rhone, 
 of Crau, of the plains of Lombardy, those of Bavaria, the valley 
 of the Rhine, &c. ; hence the last configuration of the valleys, the 
 denudations, and the dislocations, seen in so many different places. 
 It is from the upheaval of this part of the Alps, that the separation 
 of France and England appears to date, as well as that of Ireland, 
 by ruptures effected between Brest and Cape Lizard, between 
 Caernarvon and Dublin. It was then that the Mediterranean took 
 its present limits, in consequence of the subsidence of formations 
 which extended to the south of Marseilles, at the epoch of the 
 parisian sea. The gulf of Bothnia was perhaps produced in this 
 epoch, since the shell deposits found on some points of the coast 
 are all referred to the sub-Apennine formations. 
 
 But change of configuration in the soil was not the only conse- 
 quence of the appearance of the principal Alps ; this catastrophe, 
 extending over a great part of the world, from the height of Spain 
 
204 MODERN EPOCH. 
 
 to the centre of Asia, was marked by the sudden cooling of Euro- 
 pean countries to their present temperature. From that time 
 palms ceased to grow in Europe, and dicotyle'donous plants were 
 prodigiously increased. The rhinoceros, elephants, and panthers, 
 which had just appeared in that part of the world, became entirely 
 extinct there ; and, if the cavern bear is represented in our present 
 bear, its size is considerably diminished. The fauna of that part 
 of the world was again completely changed, and replaced by that 
 we now see. Besides, it was at this moment, probably, that man 
 appeared on the earth : in fact, on one hand, there are no human 
 remains in what has been too lightly named dilu'vium, for the 
 skeletons of Guadaloupe are of the modern epoch, and cannot be 
 reckoned ; and, on the other, the animals which then began are 
 precisely those with which man has always lived, since historic 
 time. 
 
 Modern epoch. From the epoch of the principal Alps, no general 
 geological disturbance has taken place in Europe ; and some volcanic 
 eruptions and upheavals, produced by earthquakes, are the only 
 effects that have been manifest. Such, also, appears to have been 
 the action of the 13th upheaval, which was revealed in the Morea, 
 in Naples, Sicily, and in some parts of Provence, and which, per- 
 haps, also determined the eruption of the modern volcanoes of 
 Auvergne and Vivarais, through ancient fissures, the beautiful 
 preservation of which attests their posteriority to the great denuda- 
 tions which followed the event of the principal Alps. 
 
 But if scarcely anything occurred in Europe after this great 
 event, perhaps it was not the same in other parts of the \vorld. 
 We may suspect that a great part of the immense mountain range 
 which extends through America, and traverses Asia from Kamt- 
 schatka.to the Birman empire, is the result of a more recent catas- 
 trophe ; this direction, at least, offers the most extended, the most 
 decided, and, so to speak, the least effaced feature of the exterior 
 configuration of the earth. It is there we see the greatest number 
 of active volcanoes, and consequently the most extensive and best 
 preserved communication between the interior and exterior of the 
 globe, and perhaps, also, the greatest mass of volcanic products 
 known. 
 
 Deluge. The successive appearance of great mountain chains 
 has produced great disturbances in different parts of the globe. 
 But it is evident that these catastrophes, at least those of great 
 energy, and those which extended over large spaces, as the up- 
 heavals of the Alps, Pyrenees, &c., must have manifested their 
 action over all the rest of the earth in secondary phenomena 
 of more or less importance. If a simple earthquake is enough to 
 produce a violent agitation of the sea, a sudden irruption of waters 
 on continents, these terrible revolutions could not have failed to 
 cause more or less impetuous movements in the ocean, and tern- 
 
DELUGE. 205 
 
 porary derangement of level of more or less extent. Hence, without 
 doubt, the extraordinary inundations, which, at each catastrophe, 
 have ravaged the surface of existing lands, and produced, as in our 
 day, various denudations, or superficial alluvions, of more or less 
 extent. 
 
 Now, since, without counting all that escaped the investigations 
 of science, we clearly see, in Europe, a series of successive move- 
 ments of the soil, which have modified the whole continent, and 
 many even a whole hemisphere, there is nothing absurd in admit- 
 ting that what took place at so many different times, from the most 
 ancient to the most modern epochs of formation, may have happened 
 once, somewhere after the appearance of man on the earth. Con- 
 sequently there is nothing contrary to reason in the belief of a 
 great irruption of water over the lands, a general inundation, a 
 deluge, in fact, which we find described not only in the Bible, but 
 deeply impressed in the traditions of all people, and at an almost 
 uniform date. Thus, in recognising in the recital of Moses, the 
 extraordinary circumstances which bear witness to the supernatural 
 intervention of the divine will, we see, on one hand, the material 
 possibility of the fact transmitted to us, and, on the other, we find 
 even the secret of the means brought into play ; that is, the up- 
 heavals, the subsidences, the consequent oscillations of the water, 
 which from that time became efficient causes of the great chastise- 
 ment then inflicted on the human race. If, because the known 
 results it has produced are feeble, we cannot too carefully seek the 
 cause of this great phenomenon, in the last of the upheavals to this 
 time classed, which dislocated the deposits in which traces of human 
 industry have already been found : perhaps it maybe discovered in 
 that which caused the rise of the Andes in America, and the volcanic 
 chain of central Asia, which, with a colossal development, also 
 present striking characters of relative novelty. 
 
 As to the future of our planet, everything leads to a belief that 
 the state of tranquillity we now enjoy is but temporary, like all the 
 intervals of crises during which the different sedimentary deposits 
 were formed. In fact, in the series of perturbations which, through 
 all time, have formed part of the mechanism of nature, we perceive 
 no law authorising us to conceive a termination to the succes- 
 sion of these phenomena : to accidents of little importance succeed, 
 indistinctly, either crises of the same order, or frightfu 1 catastrophes ; 
 long periods of tranquillity suddenly succeed terrible convulsions. 
 To the small upheaval of mount Viso, for example, succeeded the 
 great catastrophe of the Pyrenees ; to this the small accidents of the 
 system of Corsica, which were followed by the great event of the 
 Alps. The long period of the jura'ssic formation was disturbed 
 by the upheaval of Cote-d'Or, as the deposit of the vosgean sand- 
 stone was almost immediately arrested by the system of the Rhine. 
 18 
 
206 GEOGENY. 
 
 AH was irregular in those revolutions of which we have acquired 
 a knowledge ; no fact presents itself suggesting the idea of a 
 gradual diminution in the intensity of subterranean actions, and 
 leading us to think the earth has lost the property of being suc- 
 cessively broken and ridged in all directions. Nothing, therefore, 
 can assure us that the period of calm in which we have lived for 
 upwards of 5000 years (the period of the deluge), will not be dis- 
 turbed, in its turn, unexpectedly, by the appearance of some new 
 system of mountains ; the effect of a new dislocation of the soil, the 
 foundations of which earthquakes show not to be unshakable. 
 Hence it follows that the idea of an end, or a renewal of things 
 here below, as widely spread as the great inundation which has 
 passed, is also in the order of the laws which govern the universe. 
 
 Geogeny. The history of the various systems which have been 
 imagined to explain the origin of the universe, and of the earth in 
 particular, might perhaps afford some attraction to the curious ; but, 
 besides occupying a great deal of time in pure romance, it is, per- 
 haps, better to forget the many mental vagaries we should be 
 forced to expose. A single geogenv is worthy of our attention ; 
 it is that which is related in the Book of Moses, and which, 
 after a lapse of more than 3000 years, still presents, on one 
 hand, the clearest application to the best established theories, 
 and, on the other, the most succinct account of great geological 
 facts. 
 
 What is more rational, in fact, and more in conformity with 
 even our most precise knowledge, when we think of bringing order 
 into the general confusion of things, than to create the vehicle by 
 means of which the phenomena of light, of heat, &c., may be 
 manifest, and infuse life everywhere, than to collect the scattered 
 elements into groups separate from each other, than to establish 
 here and there centres of attraction around which all may gravitate 
 according to an immutable law ? Nevertheless, this is what we 
 find, with fewer details, no doubt, than we could give by means of 
 our acquired knowledge, in brief and common language intelligible 
 to all, in the first verses of Genesis, which thus state three succes- 
 sive and distinct facts. We there find, indeed, in outline : Dens 
 fecit LUCEM (the fluid of light, of heat, &c.), FIRMAMENTUM (space, 
 and all the masses scattered through it), SOLEM ET STELLAS (the 
 centres of attraction), &c. 
 
 As to the organic creation, it is divided into four successive, and 
 also rational epochs. The first established vegetative fife, or life 
 of nutrition, which is manifested not only in plants, but also in the 
 inferior animals, in which we find scarcely any other phenomena 
 than those of nutrition, growth, &c. Afterwards came the life of 
 relation or sensibility, instinct, intelligence, and will, successively 
 added, in different proportions, to the phenomena of simple existence. 
 
GEOGENY. 207 
 
 This new life first takes a certain development in fishes (including 
 reptiles, no doubt), then birds, which, together, constitute the second 
 epoch of creation. It acquired a new extension in mammals, which 
 appeared at a third epoch ; and finally reached its highest degree 
 in man, with whom terminated the work of the OMNIPOTENT, 
 receiving a soul in the image of God, to distinguish him from all 
 other creatures. 
 
 This is without doubt a wonderful example of successive organic 
 combinations ; but it is also precisely the order in which all the 
 remains buried in different ages successively present themselves. 
 Those we meet in deposits we regard as the most ancient, are the 
 calcareous remains of certain polypa'ria, mussels, sometimes even 
 the shell of some acephalous mollusks, the trilobite crusta'ceans, 
 and the remains of plants, the accumulation of which formed the 
 anthracite of the devonian formations. The abundance, the extent, 
 the thickness of these combustible beds announce the great luxu- 
 riance of vegetation, which leads us to believe that plants existed 
 for a long time, and that perhaps their first debris have disappeared 
 in the profound metamorphisms which modified the deposits in 
 which they might have been. 
 
 Fishes are not met with prior to the devonian formations, and it 
 is only in the coal deposits they present a strength of organization, 
 which is lost in the succeeding deposits, and which is not known 
 even now on the globe. Reptiles have left their remains in the 
 new red sandstone, or penine formations which followed ; and the 
 birds, the creation of which Genesis also places in the same epoch, 
 have left the imprints of their feet on the sandstones. 
 
 Mammals did not appear until long afterwards ; the traces of 
 those found in the great o'olite belonged to the least perfect orders: 
 it is only in the tertiary strata that their debris of every species are 
 found in abundance. 
 
 Human remains are not found in any of the beds which have 
 been upheaved from the bosorn of the waters, and now forming 
 parts of our continents; it therefore follows that this privileged 
 being of the general creation did not appear on the globe until after 
 the animals whose fossil debris have been found ; he dates from 
 an epoch comparatively very recent, which is placed after the up- 
 heaval of the principal Alps ; his formation would consequently 
 go back about 6800 years, according to admitted chronology. 
 It is in deposits formed under the waters since this catastrophe 
 that the bones of man should be found, and they will not appear 
 from that time in the series of geological beds until new revolu- 
 tions shall have transformed the sediments still found under water 
 into dry land. 
 
 It is clear from this outline that the brief statement of sacred 
 history is entirely in conformity with geological generalities. Ob- 
 
208 GEOGENY. 
 
 scrvation alone enables us to add a great number of details, 
 useless no doubt to most men, but interesting at least to the small 
 number of those who dedicate themselves to study, if indeed 
 they are not destined perhaps to enlighten their belief. 
 
 The assemblage of data we now possess leads us to perceive 
 that each of the particular creations briefly indicated in Genesis, 
 with the exception of that of man, did not take place in a single 
 moment ; that, on the contrary, it was successively, in a considera- 
 ble space of time, and in proportion as the terrestrial globe itself 
 was fashioned. Indeed, if the vascular cryptoga'mia appeared 
 nearly from the commencement of things, the gy'mnospe'rmous 
 phaneroga'mia did not appear until about the epoch of the coal 
 formation, and did not exist in abundance until long afterwards ; 
 it is the same with the monocotyledons, the remains of which are 
 at first few and indistinct, and not clearly seen until after the chalk ; 
 the dicotyledons did not appear until still later, in the midst of the 
 tertiary formations. In all this interval of time, the species suc- 
 cessively changed, and those which were created, have in turn also 
 entirely disappeared, one after the other, to give place to the 
 new. 
 
 Fishes, reptiles and mollusks, respectively present us with the 
 same phenomena, and still more clearly show the successive ex- 
 tinctions of different races, and the appearance of many others. 
 The sauroid fishes, which lived at the time that coal was formed in 
 Belgium and England, disappeared for ever in the new order of 
 things, established in the penine formation. True sharks did not 
 exist then, but appeared long after in the creta'ceous sea. Gigan- 
 tic saurians, with paws in form of paddles, and flying saurians, 
 existed in abundance in the jura'ssic epoch, but disappeared in 
 the following period, and were replaced in it by enormous ter- 
 restrial saurians, of which there are no previous traces, and, after 
 long having inhabited the earth by themselves, the latter were 
 also successively lost, leaving only crocodiles after them, still very 
 different from those of the present day. The same is true of the 
 tri'lobites, productus, and spi'rifers, which, after having multiplied 
 for some time, disappeared one after the other. The ammonites and 
 belemnites succeeded them, and are found in abundance in the 
 jura'ssic sea ; then they became completely extinct, after having 
 successively changed species, at the moment in which the chalk 
 formation ceased to take place. All the mollusks that followed 
 after, more and more resemble those now existing, of which there 
 was then no trace. 
 
 Mammals present themselves under similar circumstances ; the 
 different orders and different species appeared only in succession. 
 The first were only the feeble marsupials. Long afterwards came 
 the pachyderms, analogous to the tapir, the first species of which 
 
GEOGENY. 209 
 
 were soon annihilated. Other species of the same genus suc- 
 ceeded them, and these were found associated with new animals, 
 the ma'stodon and dinothe'rium, but they soon afterwards became 
 extinct for ever. Still later came the elephants ; they only appeared 
 with the carni'vora, the rode'ntia, &c., the species of which were 
 still only the prelude to those which appeared at the same time 
 with man. 
 
 All these successive changes in the series of creatures coincide 
 with the great disturbances of the surface of the globe. It was at 
 the instant of the catastrophes, produced by movements of the soil, 
 that families, genera, species of organic bodies which had until 
 then existed, disappeared. In times of the succeeding calm, on 
 the contrary, .the new organization was developed in harmony 
 with the new atmospheric circumstances, and new dispositions 
 of the isothermal lines, &c. 
 
 These details, which observation enables us to add to the 
 recital of Genesis, are in general harmony with the facts, there 
 found briefly enunciated, and of which they are but the develop- 
 ment ; the only difficulty presenting itself is that of the appli- 
 cation of the word day, which, happily, even in the eyes of 
 legitimate judges, from Saint Augustine down, does not seem to 
 possess the value which people have naturally attributed to it. 
 This expression seems in fact to have been adopted, only as an in- 
 dication of relative epochs, as the means of making understood 
 and retaining the order and succession of things which were at 
 once revealed. It is clear, indeed, that minute details categorically 
 established by figures, which would satisfy the curiosity of a small 
 number of men, would not be either received or comprehended 
 by the vulgar, who, nevertheless, are entitled to this important 
 instruction. We ourselves often resort to ways still more crooked 
 to make ourselves better understood by all : it is in this way, for 
 example, we speak of the rising and setting of tfye sun, to describe 
 the arrival of this luminary to the meridian, to the solstice, &c., 
 although we know very well that we must attribute these pheno- 
 mena to the inverse movements of the earth. 
 
 According to geological observations, this common expression, 
 days, ought to signify epochs, which embrace long periods of 
 time, each being relative to a certain system of creation in which 
 there were different formations of creatures, as well as success- 
 ive extinctions of those previously existing. Each period be- 
 gan at a particular date, clearly determined, and marked by a 
 catastrophe which overturned the order of things anteriorly esta- 
 blished on the earth ; it was extended, for a longer or shorter time, 
 sometimes through succeeding epochs, and often up to the appear- 
 ance of man himself. According to the conjectures of the scien- 
 tific, an immense time elapsed between the formation of the first 
 18* 
 
210 GEOGENY. 
 
 sediment and the last, without counting the period required 
 for the consolidation and first cooling of masses of planetary mat- 
 ter. It was in long series of ages, which are but as instants in 
 eternity, that the earth was fashioned, as we now behold it, by 
 every kind of movement in the soil, by sedimentary deposits of 
 different kinds, and finally prepared as the sojourning place of 
 man, for whom God has disposed everything. 
 
GEOLOGY. 
 
 GLOSSARY. 
 
 The following abbreviations are used : 
 
 Pr. French 
 
 fr. fr. from the French 
 
 Ger. German 
 
 fr. ger. from the German 
 
 Gr. Greek 
 
 fr. gr. from the Greek 
 
 It. Italian 
 
 ABXO'HMAL fr. lat. ab, .from, nor- 
 ma, rule, Not conformable to 
 rule. 
 
 ABXO'HMOUS Out of rule; missha- 
 pen. 
 
 ACEPH'ALOUS (a-kef'al-us.) fr. gr. 
 a, without, kephqle, head. Without 
 a head ; headless. 
 
 ACTIN'OLITE and ACTY'XOLITE fr. 
 gr. aktin, a ray ; lithos, a stone. 
 A variety of hornblende which 
 usually occurs in fascicular crystals. 
 There are three varieties of this 
 mineral ; crystallized, asbestous, 
 and glassy. 
 
 ACULEA'TUS Lat. Aculeate ; having 
 a sharp point, (p. 49.) 
 
 ACUMIX A'TA Lat. Acuminate ; 
 pointed ; peaked, (p. 59.) 
 
 ACU'TA Lat. Acute ; sharp pointed. 
 
 ACUTICO'STA Lat. (acutus, pointed, 
 and costa, rib.) Having pointed 
 ribs or sides. 
 
 A'CUTTLO'BA Lat. (acutus, pointed ; 
 loba, a lobe.) Having sharp or 
 pointed lobes. (Fig. 169, p. 88.) 
 
 ADU'LT Fr. Lat. adolesco, I grow. 
 Full grown. 
 
 A'GATE fr. gr. agathos, good, pre- 
 cious. An aggregate of certain 
 siliceous minerals, chiefly chalce- 
 dony, variously coloured. Moss 
 
 fr. it. from the Italian 
 
 Lat. Latin 
 
 fr. lat. from the Latin 
 
 Sp. Spanish 
 
 fr. sp. from the Spanish 
 
 Plur. Plural. 
 
 agate or Mocha stone is a chalce- 
 dony containing within, moss-like 
 delineations of a yellowish-brown 
 or green colour. 
 
 AGGLO'MERATE fr. lat. agglomero, 
 I wind up. To gather together. 
 
 AGGLOMEHA'TIOX A mass made up 
 of parts gathered together. 
 
 AGGLUTINATED fr. lat. ad to, glu- 
 ten, glue. United together 5 ad- 
 hering. 
 
 ALJEFO'RMIS Lat. (a/a, \ving,forma, 
 shape). Wing-shaped. (.Fig. 119.) 
 
 ALBITE fr. lat. albus, white. A 
 mineral. See p. 120. 
 
 ALBITIC Of the nature of albite. 
 
 AL'GJE Lat. plur. of alga. Seaweed. 
 Systematic name of a family of 
 plants. 
 
 ALLU'VIAL Of the nature of allu- 
 vium. 
 
 AT.LU'VIOX, } fr. lat. alluo, I wash 
 
 ALLU'VIUM, 5 upon. Gravel, sand, 
 mud, and other transported matter 
 washed down by rivers and floods 
 upon land not permanently sub- 
 merged beneath water. A deposit 
 formed from transported matter, 
 (p. 94.) 
 
 ALPINE Belonging or relating to the 
 Alps. 
 
 ALU'MISTA fr. lat. alurnen, alunii 
 (211) 
 
212 
 
 GLOSSARY. GEOLOGY. 
 
 Pure argil ; the basis of alum ; one 
 of the earths. 
 
 ALU'MINOUS Of the nature of alu'- 
 mina. 
 
 ALVEOLA'TUS Lat. Alve'olate. Hav- 
 ing the surface covered with nu- 
 merous depressions, comparable to 
 the alve'oli or sockets of the teeth. 
 
 AMBLY'PTKRUS fr. gr. amblus, ob- 
 tuse, pteron, wing. A fossil fish. 
 
 AMBULA'CRA Lat. plur. of ambula- 
 crum. The narrow longitudinal 
 portions of the sea-urchin (Echi- 
 nus), which are perforated with a 
 number of small orifices, giving 
 passage to tentacular suckers, and 
 alternate with the broad tuberculate 
 spine-bearing portions, (p. 54.) 
 
 AMBTJLA'CRUM Lat. An alley. 
 
 AMMO'NIA Lat. Relating to Am- 
 mon, a name of Jupiter. Specific 
 name of a fossil shell, (p. 67.) 
 
 AMMO'NIS Lat. Genitive case of 
 Ammon, a name of Jupiter. 
 
 AM'MOXITE fr. lat. Amman, (p. 
 51.) 
 
 AMO'RPHOUS fr. gr. a, without, 
 ntorphe, form. Shapeless. 
 
 AM'PHIBOLE fr. gr. amphibolos, 
 equivocal, (p. 121.) 
 
 AMPIE'XUS fr. lat. ampledo, I em- 
 brace. Generic name of a fossil. 
 
 AMPULLA'RTA fr. lat. ampulla, a 
 round, swelled out bottle. Name 
 of a genus of snails. 
 
 AMY'GHALOID fr. gr. amugdalon, 
 an almond, eidos, form. Almond- 
 shaped. Applied to certain rocks 
 in which other minerals are oc- 
 casionally imbedded like almonds 
 in a cake. A particular form of 
 volcanic rock. 
 
 ANA'LOGY fr. gr. ana, between; 
 logos, reason. Resemblance or re- 
 lation things bear to each other, 
 although not exactly alike in all 
 respects. 
 
 ANA'LOGOUS Having analogy, or re- 
 sembling. 
 
 AN'ALOGUE A substance or article 
 having ana'logy to others may be 
 
 . called the an'alogue of those things 
 
 with which its properties or points 
 of resemblance are comparable. 
 
 ANAN'CHYTES A genus of fossil sea- 
 urchins, p. 62. 
 
 ANDALU'SITE A mineral first ob- 
 served in Andalusia in Spain. It 
 is very hard and infusible, and 
 consists chiefly of alu'mina and 
 si'lica. 
 
 AXFRACTUO'SITY Fr. Lat. anfrac- 
 tus, the bending or winding of a 
 way. An irregular hollow or 
 groove. 
 
 ANGLE OF DIP. See p. 185. 
 
 AN'HYDROUS fr. gr. a, without, 
 udor, water. Without water. Ap- 
 plied to salts and certain acids 
 when deprived of water. 
 
 AN'NULAR fr. lat. annulus, ring. 
 Shaped like a ring. 
 
 ANNULA'R*A fr. lat. annulus, ring. 
 Generic name of a fossil plant, 
 (p. 41.) 
 
 ANOIIO'NTA fr. gr. a, without; 
 odous (genitive, odoutos), tooth. 
 Systematic name of a kind of mus- 
 sel, p. 149. * 
 
 ANODO'KTJE Plur. of Anodonta. 
 
 ANOPLOTHE'IUUM fr. gr. a, with 
 out, oplon, arm, or anoplos, un- 
 armed ; and therion, beast. P. 82, 
 fig. 156. 
 
 AIVTICLI'NAL AXIS, ^ fr. gr. anti, 
 
 AjrriCLi'uAL LINE, 5 against ; kli- 
 nein, to incline. An imaginary 
 line towards which strata, dipping 
 in opposite directions, rise. p. 160. 
 
 AxTiauA'Tus Lat. Antiquated, out 
 of date, abolished. 
 
 ANTHRACITE fr. gr. anthrax, char- 
 coal. Mineral charcoal. A kind 
 of stone-coal difficult to inflame. 
 
 A'NTHRACITI'FEROUS fr. lat. an 
 thracite, and the Lat. fero, I bear. 
 Containing or affording anthra- 
 cite. 
 
 Apio'cRiifiTEs fr. gr. apion. a 
 pear ; krinon, lily. The pear en- 
 crinite (p. 149). A sub-genus of 
 fossil encri'nites, in which the stem 
 is rounded and dilated, at its upper 
 part, into a pyriform shape. 
 
GLOSSARY, GEOLOGY. 
 
 213 
 
 AQ.UA/TIC fr. lat. aqua, water. Re- 
 lating or belonging to water. 
 
 Ao.t'iLi'NA Lat. Of or like an eagle; 
 rapacious. 
 
 AHAUCA'RIA (From Arauco, a dis- 
 trict of Chile.) Fir-trees with very 
 rigid branches, having leaves like 
 scales either small and sharp-point- 
 ed, or stiff, spreading, and lanceo- 
 late. The Norfolk island pine is 
 one of this genus. 
 
 ARBORE'SCEXT fr. lat. arbor, a tree. 
 Branching like a tree. 
 
 AHCUA'TA Lat. Arched; bent like a 
 bow. 
 
 AREXA'CEOUS fr. lat. arena, sand. 
 Sandy ; of the nature of sand. 
 
 ARGIJ. fr. lat. argil/a, clay, which 
 is formed from the Greek argos, 
 white ; because when pure it is 
 white. Old name of alu'mina. 
 
 ARGILLA'CEOUS Of the nature of 
 clay. 
 
 ARGILLA'CEOUS-SCHIST Clay slate, 
 or argillite. 
 
 AR'GILLITE A slaty rock of fine tex- 
 ture, with a faintly glistening, or 
 earthy surface of fracture, and 
 mostly of a dark colour. Roofing 
 slate, and nova'culite or hone-slate 
 are varieties of argillite. 
 
 ARGILO-ARENA'CEOUS Partaking of 
 the nature of both clay and sand. 
 
 ARIETI'NA Lat. Belonging or re- 
 lating to a ram. 
 
 ARKOSE A name given to different 
 metamorphic sandstones, (p. 178.) 
 
 ARTICULA'TION fr. lat. articulus, 
 a joint. A joint betwixt bones. 
 
 A'SAPHUS fr. gr. asaphes, obscure. 
 A name devised to express the ob- 
 scure nature of a genus of trilobites, 
 fossil crustaceans (p. 28.) 
 
 ASBF/STUS, or ASBESTOS fr. gr. 
 asbestos, unconsumable. A fibrous 
 soft mineral, composed of easily 
 separable filaments of a silky lustre. 
 It consists essentially of si'lica, mag- 
 nesia and lime. 
 
 AST A' RTF/ Name of a genus of fos- 
 sil bivalve shells. (Figs. 104, 105, 
 176.) 
 
 ASTRE'A fr. gr. aster, a star. A 
 genus of poly pa'ria. (p. 141.) 
 
 ASTKE';E Plur. of Astrea. 
 
 ATHLE'TA Specific name of mol- 
 lusk. 
 
 AU'GITE fr. gr. auge, lustre. A 
 mineral, the same as pyroxene. 
 
 AU'GITIC-PORPHYRY Crystals of 
 Labrador feldspar, and of augite in 
 a green or dark-grey base. 
 
 AVALA'NCHE Mass of hardened 
 snow, detached from lofty moun- 
 tains, which overturns everything 
 in its way, often causing great de- 
 struction. Applied also to slides 
 of earth and clay. 
 
 AVI'CULA fr. lat. avis, a bird. 
 Name of a genus of bivalve mol- 
 lusks. (Figs. 63, p. 52.) 
 
 A'xis OF ELEVA'TION Line of ele- 
 vation. 
 
 BAC'CILAR fr. lat. bacca, a berry. 
 Berry-like. 
 
 BA'CULITES fr. lat. bacculum, a 
 stick. A genus of tetrabranchiate 
 cephalopods, the chambered shells 
 of which are quite straight, but 
 differ from those of the orthocera- 
 tites in having sinuous or undu- 
 lated partitions with lobated 1nar- 
 gins : in this structure they are 
 allied to the Ammonites, (p. 72.) 
 
 BAG-SHOT SAND. A siliceous bed 
 which overlies the London clay 
 formation, corresponding in age 
 with the Paris basin. 
 
 BALA'NI Plur. of balanus. 
 
 BALA'NUS Lat. A barnacle, (p. 
 85.) 
 
 BALLOTS Fr. ballon, a ball. Round- 
 ed mountains are so called. A sys- 
 tem of upheaval p. 191. 
 
 BARRA'NCO Sp. A ravine. 
 
 BASA'LT A rock essentially com- 
 posed of feldspar, and augite of a 
 compact texture, and dark green, 
 grey or black colour. It occurs in 
 columnar masses. When light-co- 
 loured, with the feldspar predomi- 
 nating, it is sometimes called grey- 
 stone. Basalt closely resembles 
 greenstone. 
 
214 
 
 GLOSSARY. GEOLOGY. 
 
 BASA'LTIC Of the nature of ba- 
 salt. 
 
 BASSET Outcrop, or emergence of 
 strata at the surface. 
 
 BASTERO'TI Specific name of a fos- 
 sil (p. 90). 
 
 BATRA'CHIAIT (Ba-trak'-ean} fr. 
 gr. batrachos, frog. A kind of 
 reptile resembling a frog in its mode 
 of organization. 
 
 BELE'MNITES fr. gr. bekmnon, a 
 dart. A genus of fossil dibranchiate 
 cephalopods, the shells of which are 
 chambered and perforated by a si- 
 phon, but internal. They are long, 
 straight, and conical ; and com- 
 monly called " thunder stones" (p. 
 55 and 74). 
 
 BELLE'RAPHON. p. 38 and Jig. 33. 
 
 B ICORDA'TUS Lat. Bicordate ; double 
 heart-shaped. 
 
 BI'FURCATED fr. lat. bis, two,furca, 
 fork. Divided into two branches. 
 
 BIOCULA'TA fr. lat. bis, two, ocu- 
 lus, an eye. Two-eyed. 
 
 BITU'MEN fr. gr. pitus, the pitch- 
 tree ; because it resembles pitch. 
 A variety of inflammable mineral 
 substances,, which, like pitch, is in- 
 cluded under this term. 
 
 BITU'MENIZED Converted into bi- 
 tu'men. 
 
 BITU'MINOUS Of the nature of bi- 
 tumen. 
 
 BITU'MISTOUS SHALE A slaty rock 
 containing bitumen. 
 
 BI'VALVE fr. lat. bis, two, valvae, 
 doors. Shells composed of two 
 pieces united by a hinge are termed 
 bivalves. 
 
 BLENDE Sulphuret of zinc, a com- 
 mon shining zinc ore. 
 
 BLUMENBA'CHII The name of Blu- 
 menbach latinized. 
 
 BOSSE French. A hillock ; a round- 
 ed projection or elevation. 
 
 BOTHY'OIDAL fr. gr. botrus, a bunch 
 of grapes, and eidos, resemblance. 
 Clustered like a bunch of grapes; 
 covered with smooth, rounded 
 
 BOULDER FORMATION, p. 93. 
 
 BRAC'HIOPOD (Bra'ke-o~pod.) fr. 
 gr. brachion, arm, pous, foot. A 
 mollusk with a two-lobed mantle 
 and bivalve shell. (See Concho- 
 logy, p. 88.) 
 
 BRACHY'PHY'LLUM fr. gr. brachus, 
 short, phullon, leaf. A genus of 
 fossil plants. (Fig. 94, p. 61.) 
 
 BRADFORD CLAY An English bed 
 of the great o'olite, usually consist- 
 ing of a pale greyish clay, Contain- 
 ing a small proportion of calcareous 
 matter, and inclosing thin slabs 
 of tough brownish limestone. It 
 abounds in fossil apiocrinites. 
 
 BRASH A provincial word used in 
 England to describe the alluvial 
 mass or quantity of broken and 
 angular fragments of subjacent rock, 
 found usually between the vegeta- 
 ble mould and the regular rocks. 
 It is also called rubble. 
 
 BRE'CCIA (break' -co) It. A rock 
 composed of an agglutination of 
 angular fragments. When the frag- 
 ments are rolled pebbles, it consti- 
 tutes a conglomerate rock called 
 pudding stone. 
 
 BREVIFO'LIA Lat. from brevis, short, 
 folium, leaf. Short-leaved. 
 
 BRONGXIARTII Specific name of a 
 fossil in honour of M. Brongniart, 
 the eminent French naturalist, 
 (p. 60.) 
 
 BUC'CINUM Lat. A trumpet or 
 horn. Name of a genus of mol- 
 lusks. (p. 90.) 
 
 BU'CHII The name of Von Buch 
 latinized. 
 
 BUCKLA'JTDII Specific name of cer- 
 tain fossils, given in honour of 
 the eminent geologist Dr. Buck- 
 land. 
 
 BUPRE'STES Lat. Noxious insects. 
 Certain beetles. 
 
 CALA'MITES fr. gr. kalamos, a reed. 
 Common fossil plants in the coal 
 strata. Cala'mites usually consist 
 of jointed fragments which are sup- 
 posed to be portions either of the 
 trunk, or branches of a plant, which 
 appears from some of the larger 
 
GLOSSARY. GEOLOGY. 
 
 215 
 
 specimens, to have attained the 
 dimensions of a tree. Both stem 
 and branches were deeply ribbed 
 along their whole length, and the 
 ribs or furrows were crossed by 
 horizontal rings at irregular inter- 
 vals (p. 42). 
 
 CALC-SINTER Ger. sinlern, to drop. 
 A German term for limestone de- 
 posited from springs and waters 
 containing it. Travertin. 
 
 CALCA'IRE GROSS'IER Fr. Marine 
 limestone. 
 
 CALCA'IRE SILI'CEUX Fr. Fresh 
 water or siliceous limestone. 
 
 CALCA'REOUS fr. lat. calx, lime. 
 Containing lime. 
 
 CALCAREOUS GRITS Sandy beds, in- 
 termixed with calcareous matter, 
 found in the o'olite (p. 62). 
 
 CALCE'OLA fr. lat. calceolous, a 
 little shoe. A fossil bivalve shell 
 (p. 33). 
 
 CALCI'FEROUS fr. lat. calx, lime, 
 fero, I bear. Containing lime. 
 
 CAI/CINED fr. lat. calx, lime. Con- 
 verted into calx or a friable sub- 
 stance by the action of fire. 
 
 CALCINA'TION The reduction of 
 bodies to a calx or friable condition 
 by the action of fire. 
 
 CAL'VUS Lat. Bald. Specific name 
 of a productus. 
 
 CALT'MEN E fr. gr. kekalumene, 
 concealed. A name of a genus of 
 trilobites (p. 29). 
 
 CAMBRIAX SYSTEM p. 27. 
 
 CANUJEFO'RMIS Lat. fr. canna, a 
 reed, formis, form. Reed-shaped 
 (p. 42). 
 
 CANIS Lat. Dog. 
 
 CAR'BOX fr. lat. carbo, a coal. 
 The pure inflammable principle of 
 charcoal ; in its state of absolute 
 purity, it constitutes the diamond. 
 
 CAR'BOSTATE A compound of car- 
 bonic acid with a salifiable base ; 
 carbonate of lime, for example, is 
 a compound of carbonic acid with 
 lime, constituting chalk, limestone, 
 marble, &r 
 
 CARBON A'CEOUS Belonging or relat- 
 ing to carbon. 
 
 CAR'BONIC ACID An acid, com- 
 pounded of carbon and oxygen. 
 
 CAR'BONOUS Of the nature of car- 
 bon. 
 
 CARBOXI'FEROUS fr. lat. carbo, a 
 coal, fero, I bear. Containing 
 carbon. 
 
 CAR'BOJT ISEB Converted into carbon. 
 
 CARBONTSA'TION The action of 
 forming or converting a substance 
 into carbon. 
 
 CAR'BURET A combination of car- 
 bon with a metal or other sub- 
 stance ; steel and black lead are 
 carburets of iron. 
 
 CAR'BUHETTED Converted into a 
 carburet ; containing carbon. 
 
 CAR'DIUM Lat. A cockle. A genus 
 of bivalve shell (p. 81). 
 
 CARINA'TA Lat. from carina, a keel. 
 Carinate ; having a keel-like eleva- 
 tion. 
 
 CARJTI'VORA Lat. Carnivorous. 
 Carni'vorous animals. 
 
 CARSTI'TOROUS fr. lat. caro, (geni- 
 tive carra's,) flesh, voro, I eat. 
 Flesh-eating. 
 
 CA'RYOPHY'LLTA fr. lat. caryo'- 
 phyllus, the garden pink. A genus 
 of Ma'drepo'ra (p. 141). 
 
 CAS'CADE fr. fr. A cataract ; a 
 water-fall. 
 
 CATE'NA Lat. A chain. Specific 
 name of an ammonite (p. 152). 
 
 CA'TENATED fr. lat. catena, a chain. 
 Linked together. 
 
 CATEXIPO'RA fr. lat. catena, a 
 chain, pora, pore. Generic name 
 of a polyp (p. 31). 
 
 CA'TYIUS or CATILLUS Lat. A 
 little dish. A genus of fossil shells 
 (p. 74). 
 
 CAUDA'TUS Lat. Caudate ; having 
 a tail. 
 
 CAVE'RSTOUS fr. lat. cavus, a hol- 
 low. Containing hollows; exca- 
 vated. 
 
 CE'METTTED Joined together by ce- 
 ment. 
 
216 
 
 G L S S A R Y. G E O L G Y. 
 
 CEMENTA'TIOX When a solid body 
 is surrounded by the powder of 
 other substances, and the whole 
 heated to redness, the process is 
 termed cementation. Iron is con- 
 verted into steel by cementation 
 with charcoal. 
 
 CENTIGRADE (Thermometer) fr. 
 lat. centum, hundred, gradus, a 
 degree. Division into a hundred 
 parts. The scale of the centigrade 
 thermometer is made by dividing 
 the space between the points of 
 freezing, and boiling water, into 
 one hundred parts or degrees. 
 CEPHALA'SPIS (kej-al a'spifi) fr. gr. 
 keplialc, head, aspis, shield. A 
 genus of fossil fishes (p. 37). 
 CE'PHALOPOD (kt'f alu-pod) fr. gr. 
 kephale, head, pous, in genitive 
 case podos, foot. A mollusk which 
 has the head situated between the 
 body and feet. 
 
 CERI'THIA Plur. of cerithium. 
 CERI'THIUM A genus of turriculated 
 univalve mollusks, both recent and 
 fossil (p. 80 and 151). 
 CE'ROID fr. gr. keros, wax, eidos, 
 
 resemblance. Wax-like. 
 CESTRA'CION French, fr. gr. kes- 
 traios, name of a fish. A genus 
 of the family of sharks (p. 45). 
 CETA'CEA Lat. fr. gr. kelos, a 
 whale. Name of an order of mam- 
 mals. 
 
 CETA'CEJE Plur. of ceta'cea. 
 CETA'CEOUS Relating or belonging 
 
 to ceta'cea. 
 
 CHALCE'DONY fr. gr. kalkedon, 
 Chalcedon, in Asia, where the 
 finest specimens were originally 
 found. A semi-transparent siliceous 
 mineral, apparently found by the 
 infiltration of siliceous matters in a 
 state of solution. The chalcedo'nic 
 varieties of quartz include Chalce- 
 dony, Crysoprase, Cornelian, Sard, 
 Agate, Onyx, Cat' s-eye, Flint, and 
 Hornstone. 
 
 CHALK fr. ger. kalk. Earthy car- 
 bonate of lime. Chalk has been 
 discovered, it is said, for the first 
 
 time in the United States, in Ala- 
 bama, 1845. 
 
 CHALK MARL Marl belonging to 
 the cretaceous formation. 
 
 CHA'MA (ka-ma~) fr. gr. chad, I 
 gape. A cockle (p. 67 and 151). 
 
 CHA'RA (Origin of this word is un- 
 known.) A genus of aquatic 
 plants. 
 
 CHELO'NTANS fr, gr. chelone, a sea- 
 tortoise. Animals of the tortoise 
 tribe. 
 
 CHERT A siliceous mineral resem- 
 bling flint. It is usually found in 
 limestone. 
 
 CHLO'RITE fr. gr. chloros, green. 
 A soft, green, scaly mineral, slight- 
 ly unctuous. 
 
 CHLO'HITIC CHALK Chalk contain- 
 ing chlorite. 
 
 CHLO'RITIC SCHIST Schist contain- 
 ing chlorite. 
 
 CHROME fr. gr. chroma, colour. 
 The oxide of a rnetal called chro- 
 mium. Oxide of Chrome is green 
 and furnishes a valuable colour for 
 porcelain. 
 
 CHROXO'LOGY fr. gr. chronos, time, 
 logos, discourse. The science which 
 treats of the divisions of time, and 
 the order and succession of events. 
 
 CICA'TRICES Plur. of cica'trix. 
 
 CICA'TRIX Lat. A scar. 
 
 CIHA'RIS Lat. A cap or turban. 
 Name of a genus of Echini'dese 
 (p. 150). 
 
 CINDERS Matters remaining after 
 combustion. 
 
 CLAVELLA'TA Lat. (fr. claiming, a 
 little nail.) Marked by little pro- 
 jections or points ; knotted. 
 
 CLEAVAGE The mechanical divi- 
 sion, the laminae of rocks and mine- 
 rals, to show the constant direc- 
 tion in which they may be sepa- 
 rated. 
 
 CLIXKSTOSTE See pho'nolite. 
 
 CLTME'NIA fr. gr. klumenon, the 
 marigold ? A genus of fossil cepha- 
 lopods of the Devonian system (p. 
 33), with a chambered shell ana 
 logous to that of the ammonite. 
 
GLOSSARY. GEOLOGY. 
 
 217 
 
 COAL MEASURES The formations in 
 which coal is found. 
 
 COCCINELLOIDES fr. lat. and gr. 
 coccinella, cochineal, eidos, resem- 
 blance. Resembling the cochineal 
 insect. 
 
 COCCO'STEUS Name of a genus of 
 fossil fishes (p. 32). 
 
 COLEO'PTERA fr. gr. koleos, sheath, 
 pferon, wing. Name of an order 
 of insects. 
 
 COLU'MBA Lat. A dove. Specific 
 name of a fossil-shell. 
 
 COLUMNA'RE Lat. Columnar. In 
 form of a column. 
 
 COMING TO DAY When a vein or 
 stratum crops out or appears on the 
 surface it is said to come to the 
 day. 
 
 COMMINUTED Fractured into small 
 pieces. 
 
 COMMU'NIS-E Lat. Common. 
 
 COMPARATIVE ANATOMY The com- 
 parative study of the various parts 
 of the bodies of different animals. 
 
 COMPTO'NIA A genus of plants 
 named in honour of Henry Comp- 
 ton, Lord Bishop of London (p. 88). 
 
 CONCE'NTRIC Having a common 
 centre. 
 
 CONCE'NTRICUS Lat. Concentric. 
 
 CONCUI'FEROUS (con-kif-erous) fr. 
 lat. concha, shell, fero, I bear. 
 Shell-bearing. 
 
 CONCHY'LIAN (con-kit '-eari) Con- 
 sisting of or containing shells. 
 
 CONCRE'TIONARY FORMATION (p. 
 183). 
 
 CONDE'NSABLE GAS Any gas that is 
 susceptible of being condensed into 
 a fluid, or solid. 
 
 Cox DUIT A water-pipe ; a canal. 
 
 CONE OF ELEVATION (p. 107). 
 
 CONFORMABLE STRATIFICATION 
 When the strata are parallel to 
 each other (p. 185). 
 
 CO'NGENERS fr. lat. con, with, ge- 
 nus, race. Species belonging to 
 the same genus. 
 
 CONGLOMERATE fr. lat. conglo- 
 mero, I heap together. A rock 
 composed of pebbles cemented to- 
 19 
 
 gether by another mineral sub- 
 stance, either calcareous, siliceous, 
 or argilla'ceous. 
 
 CO'NICA Lat. Conical. 
 
 CO'NIFER fr. lat. conus, a cone, 
 fero, I bear. A tree or plant which 
 bears cones, such as pines, fir-trees, 
 &c. 
 
 CONOIDEA Lat. Conoidal. Cone- 
 shaped. 
 
 CONOID AL fr. lat. conus, a cone, 
 and the Gr. eidos, resemblance. 
 Cone-shaped ; like a cone. 
 
 CONTEMPORANEOUS fr. lat. con, 
 with, tempus, time. Existing at 
 the same time. 
 
 CONTO'RTED fr. lat. con, together, 
 torqueo, I twist. Twisted together ; 
 bent. 
 
 CO'PROLITES fr. gr. kopros, dung, 
 lithos, stone. Fossil excrement 
 (p. 44). 
 
 CORAL fr. gr. koreo, I ornament, 
 als, the sea. The hard calcareous 
 support formed by certain polypi. 
 
 CORAL RAG Certain beds of the 
 middle o'olite, consisting chiefly of 
 corals (p. 63). 
 
 COH'ALLINE Belonging or relating 
 to coral. 
 
 CORALLOI'DES Lat. from coral and 
 the Gr. eidos, resemblance. Coral- 
 like. Specific name of a devonian 
 fossil (p. 33). 
 
 COR-AN'GUINUM Lat. cor, heart, an- 
 guinum, snake-like. Specific name 
 of a fossil (p. 75). 
 
 CORNBRASH An o'olitic bed con- 
 sisting of clays and sandstones. Its 
 name is probably derived from the 
 excellence of the corn-land, which 
 results from the decomposition of 
 the limestones, and their mixture 
 with the sandstones and clay. 
 
 CORNU'TUS Lat. Horned. 
 
 CORONA'TA Lat. Crowned. 
 
 COSTA'TUS Lat. Ribbed. 
 
 CRAG FORMATION (p. 84). 
 
 CRASSATE'LLA A genus of bivalve 
 shells. 
 
 CRA'SUS Lat. Thick. 
 
 CHA'TER fr. lat. crater, a great 
 
218 
 
 GLOSSARY. GEOLOGY. 
 
 cup or bowl. The mouth of a vol- 
 cano (p. 107). 
 
 CRA'TER OF ELEVATION (p. 107). 
 
 CRATE'RIFORM In form of a crater. 
 
 GRENA'TUM Lat. Crenate ; having 
 rounded teeth. 
 
 CRETA'CEOUS ft. lat. creta, chalk. 
 Of the nature of chalk ; relating to 
 chalk. 
 
 CRINOIBEJB fr. gr. krinon, lily, 
 eidos, resemblance. A family of 
 radiate animals. 
 
 CRIOCE'RATITES fr. gr. krios, a 
 ram, and keras, a horn. A fossil 
 cephalopod (p. 67). 
 
 CHI'SES Plur. of crisis. 
 
 CRI'SIS Gr. The point of time 
 when any affair comes to its height. 
 
 CROCODI'LIAN Any animal of the 
 tribe of crocodiles. 
 
 CROP OUT When a rock, in place, 
 emerges on the surface of the earth, 
 it is said to crop out. 
 
 CRUSTA'CEAN Any animal of the 
 class of crusta'cea ; a crab. 
 
 CRYPTOGA'MIA fr. gr. kruptos, con- 
 cealed, games, marriage. Name of 
 a class of plants. 
 
 CRY'STAL fr. gr. krustallos, ice. 
 This term was originally applied 
 to those beautiful transparent varie- 
 ties of si'lica, or quartz, known un- 
 der the name of rock-crystal. When 
 substances pass from the fluid to 
 the solid state, they frequently as- 
 sume those regular forms which 
 are generally termed crystals. A 
 crystal is any inorganic solid of 
 homogeneous structure, bounded by 
 natural planes and right lines sym- 
 metrically arranged. 
 
 CRY'STALLINE Relating to, or re- 
 sembling crystals. 
 
 CRYSTALLISA'TION The process of 
 forming crystals. 
 
 CTENOIDEANS fr. gr. kteis, in the 
 genitive, ktenos, a comb. An order 
 of fishes (p. 48). 
 
 CUCTTLLA'TUS Lat. Hooded. 
 
 CUPROUS Belonging to copper. 
 
 CUVIERI The name of Cuvier la- 
 tinized. 
 
 CY'ATHOCRI'NITES fr. gr, Jcuathos, 
 a cup, krinon, lily. A genus of 
 crinoideae (p. 33.) 
 
 CY'ATHOFHYLLA Plur. cyathophyl- 
 lum. 
 
 CT'ATHOPHTLLUM fr. gr. huathos, 
 a cup, phullon, a flower. A genus 
 of polypa'ria (p, 31). 
 
 CTCA'DE^E (From cycas, one of the 
 genera.) An order of plants. 
 
 CY'CAS A name employed by the 
 ancients to designate a little palm. 
 (Fig. 306, p. 196.) 
 
 CY'CLABES Plur. of cyclas. 
 
 CY'CLAS fr. gr. kuklos, a circle. A 
 genus of gasteropods. 
 
 CYCLOJDEANS fr. gr. kuklos, a cir- 
 cle. An order of fishes (p. 49). 
 
 CY'MJBIUM fr. gr. kumba, a boat, 
 specific name of a shell. 
 
 CY'PREA fr. gr. kupris, Venus. A 
 genus of gasteropod mollusks. 
 
 CY'PRIS fr. gr. kupris, Venus. 
 Name of a genus of crusta- 
 ceans. 
 
 CYRE'NA A genus of bivalve mol- 
 lusks. 
 
 DA'TA fr. lat. datum, given, a gift. 
 Admitted facts. 
 
 DEBACLE Fr. Sudden escape of 
 water from a lake, following a 
 bursting of its barrier (p. 128). 
 
 DE'BRIS (de'-bree) Fr. Wreck, 
 ruins, remains (p. 14). 
 
 DEFRA'NCII The name of Defrance 
 latinized (p. 74). 
 
 DEGRADE fr. lat. de, privitive, gra- 
 dus, step, degree. To lessen, to 
 cut down. 
 
 DEGRADATION The act of lessen- 
 ing ; reduction. 
 
 DEJECTIONS Matters evacuated from 
 the bowels. 
 
 DELTA (p. 16 and 134). 
 
 DELTOIDEA Lat. fr. gr. letter A, 
 eidos, resemblance. Resembling a 
 delta A (p. 65). 
 
 DENTA'TUM Lat. Dentate ; having 
 sharp teeth. 
 
 DENUDE fr. lat. denudo, I strip. 
 To lay bare. 
 
 DENUDA'TION A removal of a part 
 
GLOSSARY, GEOLOGY. 
 
 219 
 
 of the land, so as to lay bare the 
 inferior strata. 
 
 DEPOSITION fr. lat. depono, I let 
 fall. The falling to the bottom of 
 matters suspended or dissolved in 
 water or other liquid. 
 
 DEPRE'SSUS Lat. Pressed, sunk. 
 
 DECS Lat. God. 
 
 DEVONIAN SYSTEM (p. 32). 
 
 DIADE'MA Lat, A diadem, a crown, 
 A genus of echini'deae (p. 54). 
 
 DI'AGRAM fr. gr. diet, through, gra- 
 phb, I write. A figure drawn for 
 illustration. 
 
 DIA'LLAGE fr. gr. diallage, differ- 
 ence. A mineral of foliated struc- 
 ture easrly divisible in one direction, 
 its natural joints and fractures ex- 
 hibiting a very different lustre and 
 appearance. 
 
 DICE' HAS fr. gr. dis, two, keras, 
 horn. Generic name of a fossil bi- 
 valve (p. 64, fig. 106). 
 
 DICOTY'LEDONS fr. gr. dis, two, 
 kotuledon, seed-lobe. A division of 
 plants, according to the Natural 
 Order. 
 
 DICOTTLE'BONOUS Relating to dico- 
 tyledons, 
 
 DIGO'NA fr. gr. dis, two, gone, 
 angle. Having two angles, 
 
 DTLATA'TA Lat. Dilated, swelled 
 out. 
 
 DILU'VIAL Relating to dilu'vium. 
 
 DILU'YIOX, } fr. lat diluo, I wash 
 
 DiLuViUM, 5 away. A superficial 
 deposit (p. 92). 
 
 DINOTHE'RIUM fr. gr. dinos, cir- 
 cular, therion, a beast (p. 86). 
 
 DI'OIUTE A variety of trap rock 
 consisting of albite and hornblende. 
 
 DIP ^Direction of the inclination of 
 strata. " To take a dip," is to mea- 
 sure the degree that a stratum in- 
 clines or dips from a horizontal line 
 (p. 185). 
 
 DIRECTION OF STRATA The Strike, 
 or line of bearing (p. 185). 
 
 DIRT-BED (Portland) p. 145. 
 
 DISAGGREGATED fr. lat. de, pri- 
 vitive, aggrego, I gather together. 
 Separated, divided, broken up. 
 
 DISAGGREBA'TION The breaking up 
 of a mass into small parts. 
 
 DlSCORDAKT STRATIFICATION Un- 
 
 conformable stratification. 
 
 DISENGAGED Separated from, freed. 
 
 DISINTEGRATE fr. lat. de, privi- 
 tive, integer, entire, whole. To 
 separate or break up an aggregate 
 into parts. 
 
 DISINTEGRATION The act of separ- 
 ating or dividing a whole into parts. 
 
 DISLOCATE fr, lat. de, privitive, lo- 
 cus, place. To put out of place. 
 
 DISLOCATION Displacement of a 
 part. 
 
 DISPOSITION fr. lat dispono, I 
 arrange. Arrangement, method, 
 order. 
 
 DISRUPTION fr. lat disrumpo, I 
 break off. The act of breaking 
 asunder. 
 
 DISTORTION fr. lat. de, from, tor- 
 turn, twisted. The act of distorting 
 or twisting out of place. 
 
 DOLICHODE'IRUS (doli-lco-dy-rus] 
 Lat fr. gr. dolichos, long, deire, 
 neck. Long-necked (p. 57). 
 
 DO'LOMITE Named after Dolomieu. 
 Magnesian marble: granular mag- 
 nesian carbonate of lime. It con- 
 tains about 45 per cent of carbo- 
 nate of magnesia. It is commonly 
 more friable or crumbling than pure 
 limestone, and less durable as a 
 building material. 
 
 DOLGMISA'TIOJT The conversion of 
 common into magnesian limestone 
 or dolomite (p. 170). 
 
 DOME fr. lat. domus, house, A 
 rounded projection. 
 
 DO'XITE A tra'chytic rock (p. 171). 
 
 DRIFT (p. 92). 
 
 DUNES Fr. Downs (p. 124). 
 
 DUVALII Name of Duval latinised. 
 
 DYKE or DIKI (p. 118). 
 
 EAKTHQ.UAKES (p. 97). 
 
 EBULU'TION The act of boiling. 
 
 ECHI'NIDJE fr. gr. echinos, a 
 
 ECHINI'DEJB 5 hedge-hog, eidos, re- 
 semblance. Systematic name of the 
 order of sea-urchins. 
 
 Ecm'>*ojDEaMs fr. gr. echinos, a 
 
220 
 
 GLOSSARY. GEOLOGY. 
 
 hedge-hog, derma, skin. A class 
 of invertebrate animals, with a crus- 
 ta'ceous integument armed with tu- 
 bercles or spines (p. 52). 
 
 EDENTA'TA Edentate. An order 
 of mammals without teeth. 
 
 EDE'NTATE fr. lat. e, without, dens, 
 tooth. Without teeth. 
 
 EFFERVE'SCEITCE fr. lat. effervesco, 
 I grow hot. The commotion pro- 
 duced in fluids by the sudden escape 
 of gas in the form of bubbles.^ 
 
 EFFU'SION fr. lat. effundo, I pour 
 out. The pouring out of a liquid. 
 
 E'LEGANS Lat. Elegant. 
 
 EMBOSS fr. fr. bo&se, a protuber- 
 ance. To cover with lumps or 
 bunches. 
 
 ENCRI'NITES fr. gr. krinon, a lily. 
 A genus of echi'noderms (p. 52). 
 
 E'NTOMO'STRACANS fr. gr. ento- 
 mos, incised, ostrakon, a shell. A 
 division of the class of crust a'cea. 
 
 E'OCE'NE (p. 78). 
 
 EPIDEMIC fr. gr. epi, upon, de- 
 mos, the people. A prevailing dis- 
 
 E'pocH The time from which dates 
 are numbered. 
 
 E'POCH OF FORMATION (p. 192). 
 
 EQ.UA'I-IS Lat. Equal. 
 EatrA'TioN fr. lat. sequare, to equal. 
 
 Equivalent. A mean proportion 
 
 between extremes. 
 
 Eauin'BRiUM fr. lat. segue, equal- 
 ly, libra, I balance. Equal balance. 
 EQ.UISE'TA Plur. equisetum. 
 EOTTISETA'CE^ fr. equise'tttm, one 
 
 of the genera. A natural order of 
 
 plants. 
 EQ.UISE'TUM fr. lat. eguus, horse, 
 
 seta, hair. A genus of plants. 
 ERO'DE fr. lat. erodo, I gnaw. To 
 
 wear away, to corrode. 
 ERO'SION The act of wearing away. 
 ERO'SIVE Corroding, wearing. 
 ERRATIC BLOCK FORMATION (p. 
 
 93). 
 ERU'PTIOST fr. lat. e, from, rumpo, 
 
 I burst. The act of bursting from 
 
 any confinement. 
 ESCA'BPMJENT fr. it. scarpa, sharp, 
 
 formed fr. lat. carpere, to cut or 
 divide. The steep face often pre- 
 sented by the abrupt termination of 
 strata where subjacent beds " crop 
 out" from under them. 
 
 ESCHAROIDES fr. gr. eschoro, a 
 fire-place, a gridiron, eidos, resem- 
 blance. Specific name of a coral 
 (p. 31). 
 
 EUOM'PHALTJS (p. 39). 
 
 EU'PHOTIDE A rock composed essen- 
 tially of feldspar and diallage. 
 
 EVOLU'TTJS Lat. Unfolded. 
 
 EXCORIA'TION fr. lat. ex, from, 
 curium, skin. An abrasion, mark 
 of a part having been rubbed from 
 the surface. 
 
 EXO'GYBA fr. gr. exo, without, gu- 
 ros, circle. Not circular. (Figs. 
 109, 115, 125, 135.) A genus of 
 unimuscular bivalves, allied to the 
 oyster. 
 
 EXPLOSION A sudden bursting with 
 noise and violence. 
 
 EXTREMITIES The limbs ; legs, 
 arms, &c. 
 
 EXUDA'TIOST fr. lat. ex, from, sudo y 
 I sweat. Transpiration. 
 
 Exu'vi-E Lat. The sloughs or cast- 
 skins, or shells of animals. 
 
 FASCI'CUI.IS Lat. Plur.of fasciculus. 
 
 FASCI'CUI.US Lat. A bundle. 
 
 FASTIGIA'TA Lat. Sharpened at top 
 like a pyramid. 
 
 FATHOM A measure of six feet. 
 
 FAULT fr. ger. fall, an accident, 
 sinking, fall (p. 158). 
 
 FAU'NA fr. lat. faunus, the name 
 of a rural deity among the Romans. 
 All animals of all kinds peculiar to 
 a country constitute the fauna of 
 that country. 
 
 FECIT Lat. He made. 
 
 FELD'SPAR, OR FELSPAR fr. ger. 
 feldspath. An important mineral 
 composed of si'lica, alu'mina, and 
 potash, with traces of lime, and 
 often of oxide of iron. It enters 
 into the composition of granite. 
 
 FELDSPA'THIC Of the nature t or be- 
 longing to feldspar. 
 
 FELIS Lat. A cat. 
 
GLOSSARY. GEOLOGY. 
 
 Specific name of a fossil 
 zamia (p. 65). 
 
 FEHRTJ'GIKOUS fr. lat/errwm, iron. 
 Containing iron. 
 
 FICOI'DES fr. lat flcus, a fig-tree, 
 and gr. eidos, resemblance. Speci- 
 fic name of a fossil plant 
 
 FIRMAMK'XTUM Lat. The firma- 
 ment. 
 
 FIS'SILE fr, lat flndo, I split. 
 Easily split 
 
 FIS'SURE A crack, a separation ; a 
 split 
 
 FLO'RA fr. lat flora, goddess of 
 flowers. All the plants of all kinds 
 of a country constitute the flora, of 
 that country. 
 
 FLU'VIATILE Belonging or relating 
 to a river. 
 
 FOLIA'CEA Lat. Foliated. 
 
 FOLIA'TED fr. lat folium, a leaf. 
 In form of leaves ; leafy. 
 
 FORAMISTI'FERA fr. lat. foramen, 
 hole,yero, I bear. Name of a tribe 
 of minute shells. 
 
 FORMA'TIOK Any group of rocks 
 formed during a particular epoch, 
 or of common origin. 
 
 Fos'sii, fr. [at.fodio, I dig. Any 
 organic body, or the traces of anj r 
 organic body, whether animal or 
 vegetable, which has been buried 
 in the earth by natural causes 
 (p. 21). 
 
 FOSSILI'FEROUS Containing fossils. 
 
 FOS'SILIZED Converted into a fos- 
 sil. 
 
 FU'LCRUM Lat. A prop. The 
 fixed point on which a lever moves. 
 
 FUM'AHOLE Fr. Subterraneous emis- 
 sion of hydrogen gas in consequence 
 of the ebullition of certain sulphu- 
 rous waters. The hole or orifice 
 through which the gas escapes. 
 
 FUMES Vapours. 
 
 FUSION The act of melting ^ state 
 of fusion, is being melted. 
 
 FU'SIFORHE' Lat Fusimorm, spin- 
 dle-shaped. 
 
 GALE'XA fr. gr. galene, lead-ore. 
 Sulphuret of lead, that is a com- 
 pound of sulphur and lead. 
 19* 
 
 GANOIDEAXS An order of fishes 
 (p. 48). 
 
 GA'RNET A mineral consisting of 
 silicates of alu'mina, lime, iron, and 
 manganese. There are several va- 
 rieties of this mineral. Garnet oc- 
 curs imbedded in mica slate, granite, 
 and gneiss, and occasionally in 
 limestone, chlorite slate, serpentine, 
 and lava. 
 
 GAS fr, ger. geist, spirit. The 
 name given to all permanently elas- 
 tic fluids or airs different from the 
 atmospheric air. 
 
 GA'SEOUS Of the nature of gas. 
 
 GAULT A kind of clay (p. 71), 
 
 GELA'TIITOUS Jelly-like. 
 
 GE'X ERA Lat Plur. of genus. 
 
 GENE'RIC Relating to genus. 
 
 GE'UUS Lat. A kindred, breed, 
 race or family. 
 
 GE'ODES fr. gr, geodes, earthy. 
 Nodules of iron stone, hollow in 
 the centre. Rounded pebbles hav- 
 ing an internal cavity, lined with 
 crystals, are also so called. 
 
 GE'OGENT fr, gr, ge, the earth, gei- 
 nomai, I beget. Science embracing 
 the theories of the formation of the 
 entire universe. 
 
 GEOGNO'STIC Relating to geognosy. 
 
 GEOG'NOSY fr. gr. ge, the earth, 
 gnosis, knowledge. Knowledge of 
 the mineral substances which con- 
 stitute the mountains and strata of 
 the earth. 
 
 GEOLO'GICAL Relating to geology. 
 
 GE'OLOGIST One skilled in geology. 
 
 GE'OLOGT fr. gr. ge, the earth, lo- 
 gos, discourse. That branch of 
 natural history, which treats of the 
 structure of the terrestrial globe. It 
 is divided into descriptive geology? 
 dyna'mic geology, which treats of 
 the forces by which the surface of 
 the earth has been modified ; prac- 
 tical and economic geology, em- 
 bracing the application of geological 
 science to mining, road-making, 
 architecture, and agriculture. 
 
 GEY'SERS From an Icelandic word 
 signifying raging or roaring. Cele- 
 
222 
 
 GLOSSARY. GEOLOGY. 
 
 brated spouting fountains of boiling 
 water in Iceland (p. 136). 
 
 GIBBO'SITY fr. lat. gibba, a bunch. 
 A protuberance. 
 
 GIGA'NTEUM 
 
 GLABER Lat. Smooth, bald, bare. 
 
 GIA'CIERS Fr. Masses or beds of 
 ice formed in high mountains, de- 
 rived from the snows or lakes frozen 
 by the continued cold of those re- 
 gions (p. 150). 
 
 GLOBA'TA. Lat. Globate, rounded. 
 
 GNEISS Ger. A rock resembling 
 granite in its constitution and ge- 
 neral characters ; but it contains 
 more mica and the colours are 
 banded, but owing to the arrange- 
 ment of the minerals, especially the 
 mica, in parallel planes. In con- 
 sequence of this structure the rock 
 splits into coarse slabs, along the 
 planes of the mica, besides having 
 the cross fracture or cleavage of 
 granite. It is often described as a 
 stratified or stratiform granite. A 
 rock intermediate between granite 
 and gneiss is called gneissoid gra- 
 nite. Gneiss is used for building 
 and flagging" (p. 25). 
 
 GON'IATITES (p. 38). 
 
 GOODHALLII The name Goodhall 
 latinized. 
 
 GRA'LLEJE Lat. Wading-birds. 
 
 GRA'NITE A crystalline aggregate 
 of quartz, feldspar, and mica. The 
 ingredients of granite vary in 
 their proportions, and the rock is 
 described as mica'ceous, feldspathic 
 or quartzose, according as mica, 
 feldspar, or quartz is the, predo- 
 minating mineral. It is called Por- 
 phyritic granite when the feldspar 
 is uniformly disseminated in large 
 crystals ; they appear like white 
 blotches, often of a rectangular 
 shape, over a worn surface of the 
 rock. 
 
 GHANI'TIC Belonging or relating to 
 granite. 
 
 GRA'NTJLAR Consisting of grains. 
 
 GKA'PHITE fr. gr. grapho, I write. 
 
 A mineral composed of carbon and 1 
 iron, constituting carburet of iron. 
 It is known as plumbago and black 
 lead,- it is used in the manufac- 
 ture of lead-pencils. 
 
 GRAU'WACKE, and GRATWACKE 
 Ger. Grey rock. A name given 
 to some of the older shales in the 
 geological series, and also to the 
 sandstones that accompany them. 
 
 GRA'VEL Small rounded stones vary- 
 ing in size from a small pea to a 
 walnut, or something larger. 
 
 GRAVITATE - fr. lat. grams, heavy, 
 To tend towards the centre of the 
 earth, as ail bodies do from their 
 weight. 
 
 GREENSAND A formation of the cre- 
 ta'ceous group (p. 70). 
 
 GREENSTONE A tough variety of 
 trap-rock, consisting chiefly of horn- 
 blende. 
 
 GRE'S BIGARRE' Fr. A fine-grained 
 solid sandstone, sometimes white, 
 but more frequently of a red, blue, 
 or greenish colour. It is the same 
 as bunter sandstein. 
 
 GRIT A coarse-grained sandstone. 
 
 GRUNDSTEIN Ger. Greenstone or 
 diorite. 
 
 GRY'PHEA fr. gr. grupos, incurved. 
 A genus of fossil bivalves. 
 
 GRT'PHITES Generic synonym of 
 the productus aculeatus (p. 49). 
 
 GRY'PHITE LIMESTONE A marl, so 
 called from containing gry'phea. 
 
 GRY'PHITENKAIK Ger. A name 
 sometimes given to zechstein (p. 49). 
 
 GYMNOSPE'RMOUS fr. gr. gurnnos, 
 naked, sperma, seed. Having naked 
 seeds. 
 
 GY'PSEOUS Of the nature of gypsum. 
 
 GT'PSUM (jVp-suw). Native sul- 
 phate of lime. The transparent 
 varieties constitute se/enite, and the 
 fine massive Alabaster. Gy'psum 
 is converted into plaster of Paris by 
 heat. 
 
 KA'MITES fr. lat. hamus, a hook. 
 A genus of extinct cephalopods, 
 inhabiting chambered shells, losing 
 their spiral form after their com- 
 
GLOSSARY. GEOLOGY. 
 
 223 
 
 mencement, and then continued for 
 a considerable extent with a single 
 bend on themselves like a hook. 
 They are found in the greensand 
 of England. 
 
 HE'LICES Plur. of helix. 
 
 HE'LIX Lat. A snail. 
 
 HE'TEROCERCAL fr. gr. 'eteros, op- 
 posite, kerkos, a tail. Having the 
 spine prolonged into the tail (p. 49). 
 
 HETERO'PHTLLA fr. gr. 'eteros, op- 
 posite, phullon, leaf. Specific name 
 of a fossil plant (p. 53). 
 
 HIBBERTI Name of Hibbert la- 
 tinized. 
 
 HIEROGLY'PHICS- fr. gr. ieros, sa- 
 cred, gluphd, I write. Sculpture 
 or scripture writing. 
 
 HI'PPUHITES fr. gr. ippouris, horse- 
 tail : a certain fish. A genus of 
 extinct mollusks, supposed to be 
 bivalve. The principal valve is of 
 a sub-cylindrical or elongated, co- 
 nical form, traversed by one or 
 more internal longitudinal ridges, 
 and closed by a small sub-circular 
 valve like an operculum (p. 68). 
 
 HIPPOPO'TOMI Lat. Plur. of hippo- 
 potamus. 
 
 HIPPOPO'TAMUS fr. gr. 'ippos, horse, 
 potamos, a river. The River-horse. 
 
 HOLO'PTICUS, and HOLOPTT'CHIUS 
 fr. gr. 0/05, the whole, ptuchios, 
 folded. A fossil fish of the ganoid 
 order, the enamelled surface of 
 whose scales was marked by large 
 undulating furrows. It had sharp 
 conical teeth (p. 44). 
 
 HO'MOCERCAL fr. gr. omos, joined, 
 kerkos, a tail. Applied to the tail 
 appended to the termination of the 
 spine, as in most of the fishes now 
 existing (p. 49). 
 
 HO'RJTBLEWDE A mineral of dark 
 green or black colour, abounding 
 in oxide of iron, and entering into 
 the composition of several of the 
 trap rocks. There are three varie- 
 ties ; common, hornblende-schist, 
 and basaltic hornblende. 
 
 HORNBLENDE-SCHIST A slaty varie- 
 ty of hornblende. 
 
 HU'MTJS Lat. Moist earth. Vege- 
 table earth or mould. 
 
 HI/MERITS Lat. Shoulder. Name 
 of the bone placed between the 
 shoulder and elbow. 
 
 HT'BODOKS fr.gr.w6o5, bent out- 
 wards, and odous, tooth. A divi- 
 sion of the shark family (p. 44). 
 
 HY'DRATED fr. gr. 'udor, water. 
 Containing water. 
 
 HYDROCHLORIC ACID An acid com- 
 posed of hydrogen and chlorine, 
 formerly known as muriatic acid. 
 
 HYDHOSTA'TICS fr. gr. 'uddr, wa- 
 ter, stad, I stand. The scfence which 
 explains the properties of the equi- 
 librium and pressure of liquids. 
 
 HY'PERSTHENE Labrador horn- 
 blende. It contains iron, si'lica and 
 magnesia. Hypersthene rock dif- 
 fers from common hornblende only 
 in its foliated crystallization and its 
 pearly or metallic-pearly lustre. It 
 is a very tough rock, with a struc- 
 ture resembling gneiss. 
 
 HYPNOIDES fr. gr. upnon, a sort 
 of moss, eidos, resemblance. Speci- 
 fic name of a fossil plant. 
 
 HY'POGESTE fr. gr. upo, under, gei- 
 nomai, I am formed. A class of 
 rocks which have not assumed their 
 present form and structure at the 
 surface of the earth, but are appar- 
 ently of igneous origin and thrust 
 up from below. 
 
 HYPO'THESIS fr. gr. upo, under, 
 tithemi, I place. A theory, or sup- 
 position. A rational conjecture. 
 
 HYPO'THETICAL Of the nature of 
 hypothesis. 
 
 I'CHTHYOSAU'RUS The fish lizard (p. 
 57). 
 
 IG'NEOUS fr. lat. ignis, fire. Re- 
 lating or belonging to fire. 
 
 IGUA'NODOX From iguana, and the 
 Gr. odous, tooth. An extinct genus 
 of gigantic herbivorous reptiles, dis- 
 covered in the south of England. 
 
 IMBRICATA'RIA Lat. As if imbri- 
 cated, or tile-like. 
 
 IMBRICA'TA Lat. Imbricate, tile- 
 like. Arranged like tiles. 
 
S24 
 
 GLOSSARY. GEOLOGY. 
 
 IMPRE'SSA Lat. Impressed, engrav- 
 en, marked. 
 
 INJEO.UIYA'LVIS Lat. Inequivalve. 
 Having unequal valves. 
 
 INCANDE'SCENCE fr. lat. incandes- 
 cere, to grow very hot, to be in- 
 flamed. The condition of great 
 heat, showing a certain light, as if 
 the heated substance itself were 
 burning. Melted. 
 
 INCANDE'SCENT Greatly heated. 
 
 INCOHE'RENT fr. lat. in, not, con, 
 with, hsereo y I adhere. Loose, want- 
 ing cohesion. 
 
 INCLINATION OF BEDS Dip (p. 
 185). 
 
 INCRIJSTA'TION fr. lat. eras/a, a 
 crust. A covering like a crust. 
 
 INEQJJILA'TERAL fr. lat. insequalis, 
 unequal, lotus, (in the genitive, 
 lateris,} side. Having unequal 
 sides. 
 
 INFILTRATION fr. lat. Jiltrare, to 
 filter. The act of filtering through, 
 producing an accumulation of li- 
 quid. 
 
 INOCE'RAMUS fr. gr. en, with, ke- 
 ramos, earthen ware? A genus of 
 bivalve fossil shells, which are chief- 
 ly characterised by their hinge and 
 the fibrous structure of their con- 
 stituent substance. The shell, in 
 consequence of the vertical arrange- 
 ment of the fibres, readily breaks to 
 pieces, and it is often extremely dif- 
 ficult to extricate a specimen with 
 the hinge and beaks tolerably 
 entire. 
 
 IN PLACE In their original position 
 where they were formed. 
 
 INIUJINA'TA Lat Stained, dirty. 
 
 INSERTED Attached. 
 
 IN SITU Lat. In place. 
 
 INTERCALATED fr. lat. intercalo, I 
 place between. Placed between. 
 
 INTERCALATION The placing one 
 substance between others, as one 
 stratum between two others. 
 
 INTERPOSED fr. lat. inter, between, 
 pono, I place. Placed between. 
 
 INTERTIUMPICAL Between the tro- 
 pics. 
 
 [NTRUSION The act of thrusting or 
 forcing in. 
 
 I'SOLATED fr. it. wo/a, an island. 
 Separated like an island. 
 
 ISOTHE'RMAL fr. gr. isos, equal, 
 therme, heat. Isothermal lines are 
 those which pass through those 
 points on the surface of the earth, 
 at which the mean annual tempera- 
 ture is the same. 
 
 JA'SPER A siliceous mineral of vari- 
 ous colours. 
 
 JOINTS OF DISLOCATION (p. 187). 
 
 JURA'SSIC Belonging to the Jura 
 mountains. 
 
 KEU'PER Ger. The upper portion 
 of the new red sand-stone forma- 
 tion (p. 52). 
 
 KJMMKIU I<;K CLAY (p. 64). 
 
 KlMMERIDGE COAL (p. 65). 
 
 KU'PFERSCHI'EFER Ger. Copper- 
 slate (p. 47). 
 
 LA'BRADORITE Labrador spar. It 
 consists of silicate of alu'mina, lime, 
 and soda, with traces of oxide of 
 iron. It is a variety of feldspar. 
 
 LABTRI'NTIIICA Lat. Labyrinth- 
 like. 
 
 LABTRI'NTHODON fr. gr. laburin- 
 thos, a labyrinth, odous, tooth. 
 An extinct genus of batrachians, 
 characterised by teeth of a peculiar- 
 ly complicated structure. The re- 
 mains of this genus peculiarly cha- 
 racterise the Keuper formation in 
 Germany and the corresponding 
 sand-stones in England (p. 196, 
 and Jig. 307). 
 
 LACE'RTIAN fr. lat, lacerta, a 
 lizard. Any animal of the lizard 
 tribe. 
 
 LACU'STRINE fr. lat. locus, a lake. 
 Belonging or relating to lakes. 
 
 L.KVIS Lat. Smooth, bare, bald. 
 
 LAM ANO'NIS Specific name of a fos- 
 sil plant. 
 
 LAMBE'RTI The name of Lambert 
 latinized. 
 
 LA'MINA Lat. Plur. laminae. A 
 plate. 
 
 LANDSLIP or LANESLIDE. The re- 
 moval of a portion of land down 
 
GLOSSARY. GEOLOGY. 
 
 an inclined surface, from its at- 
 tachment being lessened by the ac- 
 tion of water beneath, or by an 
 earthquake. 
 
 LAPI'LLI fr. lat. lapillus, a little 
 stone. Small volcanic cinders. 
 
 LATERA'LIS Lat. Lateral. 
 
 LA'VA The substances which flow 
 in a melted state from a volcano. 
 Lavas vary in consistence and tex- 
 ture. 
 
 LE'NTA Lat. Slow, heavy, stupid. 
 
 LEPIDODE'NDBA Plur. of lepidoden- 
 dron. 
 
 LEPTDODE'NDBON fr. gr. lepis, scale, 
 dendrun, a tree. A genus of fossil 
 plants, having a scaly bark. 
 
 LEPTE'NA A synonym of the genus 
 productus (p. 30). 
 
 LEYMERII The name Leymerie la- 
 tinized. 
 
 LIAS (p. 54). 
 
 LI'GNEOUS fr. lat. lignum, wood. 
 Woody ; of the nature of wood. 
 
 LI'GNITE fr. lat. lignum, wood. A 
 kind of coal. 
 
 LI/MA Lat. A file. Name of a 
 genus of bivalves. 
 
 LINEA'RIS Lat. Linear, line-like. 
 
 LINE OF BEARING Strike (p. 185). 
 
 LIQUEFA'CTION The act of becoming 
 liquid. 
 
 LITHU'ITES and LITU'ITES fr. lat. 
 lituus, a crooked staff. Fossil 
 chambered shells, curved or bent at 
 one end (Jig- 8). 
 
 LITHOGHA'PHIC fr. gr. lithos, stone, 
 grapho, I write. Lithographic stone, 
 used for the purposes of lithography 
 (p. 65). 
 
 LITIIO'PHAGI fr. gr. lithos, stone, 
 phago, I eat. Small worms found 
 in slate which give it a red co- 
 lour. 
 
 LITTORA'LIS Lat. Littoral ; be- 
 longing or relating to the shore. 
 
 LOAM A mixture of sand and clay. 
 
 LOHES Veins containing metallic 
 ores. 
 
 LOESS A German geological term, 
 applied to a tertiary alluvial de- 
 posit, which occurs in patches be- 
 
 tween Cologne and Basle. The 
 term is applied by the English to 
 that peculiar yellow loam with cal- 
 careous concretions. 
 
 LONDON CLAY (p. 78). 
 
 LONGIRO'STRIS lat. fr. longus, long, 
 rostrum, beak. Long-billed. 
 
 LONGISCA'TA Lat. A little longer. 
 
 LT'COPO'DIA'CEJE fr. gr. lukos, a 
 wolf, pous, foot. A natural order 
 of plants which includes the ly'co- 
 po'dium. 
 
 LYELLH The name of Lyell la- 
 tinized. 
 
 LYMNE'A or IIMNEA fr. gr. lirnne, 
 a pool. A genus of fresh-water 
 snails. 
 
 LU'CEM Lat. Light. 
 
 LUGDITNENSIS Lat. Belonging or 
 relating to Lyons. 
 
 LUMACHELLA See note p. 67. 
 
 MA'DREPO'RA Lat. Compound of 
 the French madre, spotted, and 
 Lat. porus, pore. A genus of 
 corals (p. 141). 
 
 MADREPORE A kind of coral. 
 
 MADHEPO'RIC Of the nature of ma- 
 drepore. 
 
 MAGNE'SIA A white, tasteless earthy 
 substance. 
 
 MAGNE'SIAN Relating to, or con- 
 taining magnesia. 
 
 MAGNE'SIATC LIMESTONE Lime- 
 stone which contains magnesia. 
 An extensive series of beds lying 
 above the coal measures. 
 
 MAGNE'TIC Having properties of the 
 magnet or load-stone. 
 
 MAG'NUM Lat. Great. 
 
 MAM'MAI. Any animal that suckles 
 its young. 
 
 MAMMALI'FEROTJS Containing mam- 
 mals. 
 
 MAMMI'LLARY fr. lat. mammilla, 
 a little nipple. Studded over with 
 small rounded projections. 
 
 MAMMOTH An extinct species of 
 elephant. 
 
 MANTE'LLIA A genus of fossil cy- 
 ca'deffi, named in honour of Mr. 
 Mantell. 
 
 MA'RGABETI'JERA fr. lat. marga- 
 
226 
 
 GLOSSARY. GEOLOGY. 
 
 ritum, a pearl, fero, I bear. Pearl- 
 bearing. 
 
 MARINE fr. lat. mare, the sea. Re- 
 lating to the sea. 
 
 MAUL Argillaceous carbonate of 
 lime. There are several varieties 
 of marl. 
 
 MA'RSHII The name of Marsh la- 
 tinized. 
 
 MAHSU'PIAL fr. lat. marsupium, a 
 pouch. Any animal having a pe- 
 culiar pouch in front or on the ab- 
 domen. 
 
 MA'STODON fr. gr. mastos, a nipple, 
 odous, tooth. A genus of extinct 
 quadrupeds allied to the elephant. 
 
 WA'TRTX Lat. The stony substance 
 in which metallic ores and crystal- 
 line minerals are imbedded. Gan- 
 gue. 
 
 MAXIMUM Lat. Greatest. 
 
 MEANDRI'NA A genus of polyps. 
 
 MEANDIUV'^E Plur. of meandrina. 
 
 MEDICAGJ/XELA Specific name of a 
 chara, a kind of fossil moss. 
 
 MEDU'LLARY HATS fr. lat. medulla, 
 marrow. The vertical plates of cel- 
 lular tissue which radiate from the 
 centre of the stem through the wood 
 to the bark in exogynous plants. 
 
 MEGALI'CHTH YS fr. gr. megas, great, 
 ichthus, fish. An extinct genus of 
 fishes, including species of great 
 size. 
 
 MEGA'LODON fr. gr. megas, great. 
 odous, tooth. A genus of peculiar 
 fossil bivalve shells. 
 
 MEGALO'NYX fr. gr. megas, great, 
 onux, a claw. A large fossil mam- 
 mal, found in Virginia. 
 
 MEGALOSAU'RUS (p. 58). 
 
 MEGATHE'KIUM (p. 92). 
 
 MELA'NIA fr. gr. melas, black. A 
 genus of fluviatile univalves. 
 
 MELA'PHYRY, and MELA'PHYRE fr. 
 gr. melas, black. A kind of por- 
 phyry the constituents of which are 
 united by a black cement (p. 173). 
 
 MEPHIT'IC fr. mephitis, the goddess 
 of foul smells. Applied to impure 
 or foul exhalations. 
 
 L] 'FZUOVS Containing metal. 
 
 METAMO'RPHIC Relating to meta- 
 morphism. 
 
 METAMO'RPHISM fr. gr. rueta, indi- 
 cating change, morphe, form (p. 
 177). 
 
 METAMO'RPHOSES Plur. of metamor- 
 phosis. 
 
 METAMORPHOSIS Change of form. 
 
 MI'CA fr. lat. mico, I shine. A 
 mineral generally found in thin 
 elastic laminae, soft, smooth and of 
 various colours and degrees of 
 transparency. It is one of the con- 
 stituents of granite. 
 
 MICA'CEOUS Of the nature of mica. 
 
 MICA-SCHIST Mica-slate (p. 25). 
 
 MI'CROSCOPE fr. gr. mikros, little, 
 skoped, I view. An optical instru- 
 ment which enables us to examine 
 objects too small to be seen by the 
 unassisted eye. 
 
 MI'CROSCOPIC Minu'te ; perceivable 
 only by aid of a microscope. 
 
 MI'LLIOLITES, or MILI'OLA fr. lat. 
 milium, a millet seed, and gr. lithos, 
 stone. A genus of foramini'ferous 
 fossil shells found in the neighbor- 
 hood of Paris. 
 
 MILLSTONE GRIT Coarse grained, 
 quartzose sandstone. 
 
 MINE Ger. Any subterraneous work 
 or excavation which has for its ob- 
 ject the extraction of any mineral 
 products, as metallic ores, coal, &c. 
 
 MINERAL Any inorganic natural 
 object, whether solid, liquid or gas- 
 eous. 
 
 MINERALOGY That branch of na- 
 tural science which treats of the 
 properties of minerals. 
 
 MINIMA } r i T 
 
 MI'NIMUM $ Lat ' Least ' 
 
 MINUS Lat. Little. 
 
 MINU'TA Lat. Minute, very small. 
 
 MI'OCENE (p. 78 and 83). 
 
 MODERN FORMATION (p. 95). 
 ! MOLA'SSE Fr. A fine grained sand- 
 stone, usually soft and loose, but 
 sometimes sufficiently hard for 
 building purposes. 
 
 MOLLUSK fr. lat. mollis, soft. Any 
 animal of the class of mollusca. 
 
GLOSSARY GEOLOGY. 
 
 227 
 
 MONI'LE Lat. Belonging or relat- 
 ing to a necklace. 
 
 MONILEFO'RMIS lat. fr. monile, a 
 necklace, forma, form. In form of 
 a necklace. 
 
 MO'XOCOTY'LEDONS fr. gr. tnonos, 
 single, kotuledon, seed-lobe. A 
 class of plants having but one seed- 
 lobe in the embryo. 
 MORAI'NES Longitudinal deposits 
 of stony detritus found at the bases, 
 and along the edges of all the great 
 glaciers (p. 131). 
 MOSASAU'RUS (p. 75). 
 MUCRONA'TUS Lat. Pointed, sharp- 
 pointed. 
 
 MCLTILO'CULAR fr. lat. multus, 
 many, loculus, a partition. Hav- 
 ing many chambers or partitions. 
 MTJ'RAL fr. lat. murus, a wall. Be- 
 longing or relating to a wall. 
 MTJ'REX Lat. A shell fish. A genus 
 
 of univalve mollusks. 
 MURICA'TA Lat. Full of sharp 
 
 prickles or points. 
 MU'SCHELKALK Ger. (p. 50). 
 MTTSCLE An organ of motion ; the 
 
 flesh of animals. 
 MTJ'SSEI, A bivalve mollusk. 
 MUTA'BILE' Lat. Mutable, change- 
 able. 
 
 MT'A A genus of bivalve mollusks. 
 NA'GELFLTJE Ger. A coarse con- 
 glomerate. . 
 
 NATJ'TILUS A genus of cephalopods. 
 
 NAVI'CTJLA Lat. A little boat. 
 
 NEOCO'MIAN and NEOCOMIEN Fr. 
 
 The lower beds of the cretaceous 
 
 system in the south of France and 
 
 elsewhere, are described by the 
 
 French geologists under this name. 
 
 NEPTUNIAN From Neptune, god 
 
 of the sea. Belonging or relating 
 
 to water, 
 
 NERI'NEA A genus of fossil uni- 
 valves, resembling both Cere'thium 
 and Turritella (p. 63). 
 NERVCRES Veins of leaves. Also, 
 the tubes for expanding the wings 
 of insects. 
 NEURO'PTERA fr.gr. neuron, a nerve 
 pteron, wing. An order of insects 
 
 NEURO'PTERIS A genus of fossil 
 plants (p. 41). 
 
 NEW RED SAND-STONE (p. 47). 
 
 NIDIFO'HMIS Lat. In form of a 
 bird's nest. 
 
 NILSO'NIA A genus of fossil plants. 
 
 NODO'SUS Lat. Knotty. 
 
 NO'DTTI.E fr. lat. nodus, a knot. A 
 rounded irregular lump or mass. 
 
 NOR'MAL fr. lat. norma, a rule. Ac- 
 cording to the peculiarities of a 
 family or genus, without the least 
 departure. 
 
 NORWICH, or NORFOLK CRAG A 
 tertiary formation which rests on 
 the London clay or chalk, and in- 
 cludes marine shells (p. 84). 
 
 NU'CLEUS Lat. A kernel. The 
 solid core of a body. 
 
 NU'CULA fr. lat. nux, a nut. A 
 genus of bivalve shells with nume- 
 rous teeth like those of a comb. 
 
 NUMMULI'TES fr. lat. nummus, 
 money, and fr. gr. lithos, stone. 
 Fossil money. An extinct genus 
 of cephalopods, of a thin lenticular 
 shape, divided internally into small 
 chambers. Nummulite limestone 
 obtains its name from the presence 
 in it of these shells in great abund- 
 ance. In Alabama there is a moun- 
 tain range entirely composed of 
 one species of nummulite. 
 
 NOTRI'TION The animal function by 
 which the various organs receive 
 nutritive substances (previously pre- 
 pared by the several organs of di- 
 gestion), necessary to repair their 
 losses and maintain their strength. 
 OBLO'NGUS Lat. Oblong. 
 OBOVA'TA Lat. Obovate. 
 OBO'YATE fr. lat. ob, for, opposite, 
 ovum, egg. Reverse of ovate or 
 egg-shaped. 
 
 OBSI'DIAN Named after Obsidius. 
 A glassy lava. Volcanic glass. It 
 consists of si'lica and alu'mina with 
 a little potash and oxide of iron. 
 OCTOPLICA'TA Lat. octo, eight, pli- 
 ca'ta, folded. Having eight folds. 
 
 OLD RED SANDSTONE (p. 37). 
 
 O'OLITE fr. gr. 00/2, an egg, lithos, 
 
228 
 
 GLOSSARY. G EC 
 
 stone. A granular variety of car- 
 bonate of lime, frequently called 
 roeslone (p. 58). 
 
 O'oLixic Belonging or relating lo 
 o'olite. 
 
 OpALE'scEirr Resembling o'pal, a 
 beautiful mineral, characterized by 
 its iridescent reflection of light. 
 
 OPE'RCULUM fr. lat. operio, I cover. 
 The lid which protects the gills of 
 fishes, and closes the opening of 
 certain univalve shells. 
 
 ORBICULA'RIS Lat. Orbicular. 
 
 ORBIT fr. lat. orbis, a circle. The 
 circular cavities in which the or- 
 gans of vision are lodged, are named 
 the orbits. 
 
 ORES fr. ger. erzc. Mineral bodies 
 from which metals are extracted. 
 
 ORGAIT fr. gr. organon, an instru- 
 ment. Part of an organized being, 
 destined to perform some particular 
 function ; the ears are organs of 
 hearing, the muscles organs of mo- 
 tion, &c. 
 
 ORGA'XIC Relating to organs. 
 
 ORGANIZED Possessing organs. 
 
 ORGAifizA'Tioir A mode of struc- 
 ture. 
 
 OHGA'JTISANS Lat. fr.gr. organoo, 
 I arrange, or provide with organs. 
 Organizing, constructing. 
 
 ORTHTS A genus of fossil bivalve 
 shells (p. 29). 
 
 OHTHOCE'RAS "> . _ 
 
 ORTHO'CERATITE j O dS > 
 
 OSCILLA'TIOX fr. lat. oscillum, an 
 image, hung on ropes and swung 
 up and down in the air. The act 
 of moving backwards and forwards 
 like a pendulum. 
 
 OSCILLA'TORY Swinging backwards 
 and forwards like a pendulum. 
 
 OSTRA'CEA Family of bivalves which 
 includes the oyster. 
 
 OS'TREA Genus of bivalves ; an 
 oyster. 
 
 OUTCROP The emergence of a rock, 
 in place, at the surface. 
 
 OUTLIER A hill or range of strata 
 occurring at some distance from the 
 
 general mass 01 formation to which 
 it belongs. 
 
 OVA'TUS Lat. Ovate, egg-shaped. 
 
 OVERLYING When one stratum lies 
 over, or overlaps another, it is said 
 to be overlying. 
 
 OXFORD CLAY (p. 62). 
 
 O'XIDE fr. gr. oxus, acid, eidos, 
 form. A compound, which is not 
 acid, containing oxygen. 
 
 O'xYGEtf fr. gr. oxus, acid, gennein, 
 to generate. Vital air. 
 
 PA'CHYDE'RMA Lat. fr. gr. pachus, 
 think, derma, skin. Thick-skin- 
 ned. 
 
 PA'CHYDE'RMATA Lat. Pa'chy- 
 de'rms. 
 
 PACHYUE'RMS An order of quadru- 
 peds, including the elephant, horse, 
 pig, &c., distinguished by the thick- 
 ness of their hides. 
 
 PA'CHYDE'RMATOUS Relating to pa'- 
 chyde'rms. 
 
 PA'CHYGJTA'TUS Lat. fr. gr. pachus, 
 thick, gnathos, jaw. Specific name 
 of the labyrinthodon (p. 197). 
 
 PAL^OXI'SCUS (p. 48). 
 
 PA'LJEOXTO'LOGIST One skilled in 
 paleontology. 
 
 PALJEOXTO'LOGY fr. gr. palaios, an- 
 cient, on, creature, logos, a dis- 
 course. That branch of zo'ological 
 science which treats of fossil organic 
 remains. 
 
 PALJE'OZOIC fr. gr, palaios, ancient, 
 zoe, life. Relating to ancient life. 
 
 PALEOTHE'RIUM (p. 83). 
 
 PALMACI'TES A genus of fossil 
 plants. 
 
 PALUDI'NA fr. lat. palus, a marsh. 
 A genus of fresh water gasteropods. 
 
 PALUDI'ITE Plur. of paludina. 
 
 PALUDINE Belonging to a marsh. 
 
 PARALLEL Extended in the same 
 direction and preserving always the 
 same distance. 
 
 PARALLE'LISM The state of being 
 parallel. 
 
 PARALLE'PIPED A solid contained 
 by six planes, three of which are 
 parallel to the other three. 
 
GLOSSARY. GEOLOGY. 
 
 229 
 
 PA'RASITE An adherent, a hanger on. 
 PARASI'TIC Of the nature of a para- 
 
 site. 
 PARI'ETES fr. lat. paries, a wall. 
 
 The sides or parts forming an en- 
 
 closure. 
 PARIS BASIN (p. 79). 
 
 PECO'PTERIS fr. gr. pekos, sheep- 
 
 skin, pteris, a fern. A genus of fos- 
 
 sil ferns. 
 PE'CTEK Lat. A comb. A genus 
 
 of bivalve mollusks. 
 PECTIKA'TA Lat. Pectinate; like 
 
 the teeth of a comb. 
 PE'LLICLE fr. lat. pellis, a skin. A 
 
 thin skin, or crust. 
 PEJTINE FORMATION New red sand- 
 
 stone (p. 47). 
 PENTA'MERUS or PENTAME'RUS fr. 
 
 gr. pente, five, meros, a part (p. 31). 
 PEJTTA'NGULA'TUS Lat. Having 
 
 five angles. 
 PERCOLATE fr. lat. per, through, 
 
 co/o, I strain. To strain or drip 
 
 through. 
 PE'RIDOT Prismatic chrysolite (p. 
 
 121). 
 PE'RLITE Pearlstone, a gray variety 
 
 of obsidian. 
 PERMANENT GAS Any gas which 
 
 remains in the aeriform state under 
 
 ordinary circumstances. 
 PERO'XIDE The highest degree of 
 
 oxidizement of which a metal or 
 
 other substance is susceptible with- 
 
 out becoming an acid. 
 PES-PELICA'NI Lat. Pelican foot. 
 PHANEROGA'MIA fr. gr. phaneros, 
 
 evident, gamos, marriage. The di- 
 
 vision of the vegetable kingdom in 
 
 which all the plants bear flowers, 
 
 and are multiplied by means of true 
 
 PHANERO'GAMOUS Belonging or re- 
 lating to phaneroga'mia. 
 
 PHEjfo'MEjr A Plur. of phenomenon. 
 
 PHENO'MENON Gr. Appearance, vi- 
 sible quality, event. 
 
 PHO'LAS fr. gr. p/ioleos, a lurking 
 place. A genus of mollusks. 
 20 
 
 PHO'LADKS Plur. of Pholas. 
 
 PHO'LODOMY'A A genus of mol- 
 lusks. 
 
 PHO'NOLITE Clinkstone, a species 
 of compact basalt, which is sonor- 
 ous when struck (p. 171). 
 
 PHOSPHO'HIC ? fr. gr. phos, light. 
 
 PHOSPHORE'SCEST 3 Emitting light 
 in the dark. 
 
 PISTILLIFO'RMIS Lat. In form of a 
 pistil. 
 
 PLACOIDEANS (p. 48). 
 
 PLACU'NEA Lat. fr. gr. plakoeis, 
 broad, flat, even. 
 
 PL.EXERKALK Ger. (p. 71). 
 
 PLAGIO'STOMA fr. gr. plagios, ob- 
 lique, stoma, mouth. A genus of 
 bivalve mollusks. 
 
 PLANO'RBIS fr. lat. planus, flat, or- 
 bis, a circle. A genus of marsh 
 snails (p. 83). 
 
 PLA'NUS Lat. Flat. 
 
 PLASTIC CLAY (p. 78). 
 
 PLASTER OF PARIS A substance pre- 
 pared by heating gypsum. 
 
 PLA'TEAU Fr. An elevated plane, 
 or table land. 
 
 PLA'TEAUX (PLA'-TO) Plur. of pla- 
 teau. 
 
 PLATI'N A or PLATI'NITM fr. sp. pla- 
 ta, silver, on account of its colour. 
 A metal of a whitish colour, exceed- 
 ingly ductile, malleable, and of diffi- 
 cult fusion. 
 
 PLATTSO'MUS (p. 48). 
 
 PLEI'SIOSAU'RUS (p. 57). 
 
 PLEIS'TOCENE fr. gr. pleistos, the 
 most, kainos, recent. The newer 
 pliocene formation or newest tertia- 
 ry- 
 
 PLEU'RONECTES fr. gr. pleura, side, 
 nektes, swimmer. A genus of 
 fishes. 
 
 PLEURO'TOMA fr. gr. pleura, side, 
 tome, a notch. A genus of univalve 
 mollusks, having a notch in the 
 side of the shell. 
 
 PLEUROTOMA'RIA A tribe of mol- 
 lusks. 
 
 PLICA'TULA fr. lat. plica, a fold. A 
 genus of mollusks (p. 72). 
 
 PLI'OCENE (p. 78 and 89). 
 
230 
 
 GLOSSARY. GEOLOGY. 
 
 PLUTONIC After Pluto, the god of 
 fire. Relating to fire. 
 
 POIKILI'TIC fr. gr. poikilos, varie- 
 gated. A name applied to the new 
 red sandstone formation in con- 
 sequence of the varieties of colours 
 it exhibits. 
 
 PO'LYP fr. gr. polus, many, pous, 
 foot. A radiated animal which has 
 a cylindrical or oval body, or sac, 
 with an opening at one extremity, 
 around which are long feelers. 
 
 POLYPA'HIA, and POLTPIA'RIA 
 Groups of polyps or animalcules 
 which form coral. 
 
 POLYPA'RIUM The skeleton or frame- 
 work formed by coral animalcules. 
 When this frame-work is of a stony 
 hardness it constitutes coral. In 
 fossils the polyparium alone re- 
 mains. 
 
 PO'ROUS Containing pores. 
 
 PORPHTRI'TIC Of the nature of por- 
 
 POR'PHYROID Resembling porphyry. 
 
 PORPHYRY fr. gr. porphura, purple. 
 Originally applied to a red rock 
 found in Egypt. A compact feld- 
 spalhic rock containing disseminat- 
 ed crystals of feldspar, the latter 
 when polished, forming small angu- 
 lar spots, of a light colour, thickly 
 sprinkled over the surface. The 
 rock is of various colours, dark 
 green, red, blue, black, &c. 
 
 PORRE'CTA Lat. Extended. 
 
 PORTLAND O'OLITE (p. 64). 
 
 POSIDO'NIA (p. 52). 
 
 POZZUOLA'NA and POUZZUOLANI 
 Volcanic ashes used in the manu- 
 facture of mortar which hardens 
 under water: exported from Poz- 
 zuoli, near Naples. 
 
 PRECIPITA'TION The action, by 
 which a body abandons a liquid in 
 which it is dissolved or suspended, 
 and becomes deposited at the bot- 
 tom. 
 
 PRISMA'TICUM Lat. Prismatic. 
 
 PRODU'CTUS A genus of extinct mol- 
 lusks (p. 29, 30, and 39). 
 
 PTERI'CHTHYS (p. 32). 
 
 PTERODA'CTYLI Lat. Plur. of pte- 
 rodactyl us. 
 
 PTERODA'CTYLUS (p. 57). 
 
 PTERO'PH YLLUM fr. gr.pteron, wing, 
 phullon,\eaf. A genus of fossil plants. 
 
 PUDDING STONE Conglomerate. 
 
 P.UMICE Vesicular obsidian. 
 
 PY'RITES A compound of sulphur 
 and iron. 
 
 PY'ROXENE (p. 121). 
 
 PYROXENIC Of the nature of py- 
 roxene. 
 
 QUADERSANDSTEIN Ger. The lower 
 cretaceous beds in Germany : any 
 sandstone fit for building purposes. 
 
 QUAQ.UAVERSAL Turning each way. 
 
 QUARRY A stone mine ; a place 
 where stones are dug. 
 
 QUARTZ Ger. Rock crystal. A con- 
 stituent of granite and some other 
 rocks. 
 
 QUA'HTZOSE Of the nature of quartz. 
 
 RADIA'TA Lat Radiate : the name 
 of a class of zo'ophytes. 
 
 RA'DTATE fr. lat. radius, a ray. 
 Furnished with rays. 
 
 RA'DIUS Lat. A ray. The semi- 
 diameter of a circle ; a ray drawn 
 from the centre to the circumference. 
 
 RADIA'TTON The emission of rays 
 of light, or of heat, from a luminous 
 or a heated body. 
 
 RA'DIOLITES A genus of fossil 
 shells ; the inferior valve of which 
 is in the shape of a reversed cone, 
 the superior valve convex (p. 69). 
 
 RAFT Trunks of trees and other 
 vegetable debris matted together, by 
 natural causes, and sunk in a river 
 or stream. 
 
 RAG (p. 59). 
 
 RAPI'LLI Small volcanic cinders. 
 
 REACTION The force exerted by two 
 bodies which act mutually on each 
 other. 
 
 REA'LGAR Red sulphnret of arsenic. 
 A compound of sulphur and ar- 
 senic. 
 
 REFRIGERA'TION The act of cool- 
 ing. 
 
GLOSSARY. GEOLOGY. 
 
 231 
 
 RESINOUS Containing resin. 
 
 RETU'SUS Lat. Retuse ; blunted. 
 
 RKVOLU'TA Lat. Turned again. 
 
 ROCK Any mineral aggregate (p.13). 
 
 RODENTIA fr. lat. rodere, to gnaw. 
 An order of mammals. 
 
 RODENTS Gnawers ; animals of the 
 order of rodentia. 
 
 ROLLED FLINTS (p. 129). 
 
 ROSTELLA'RIA fr. lat. rostellum, a 
 little beak. A genus of univalve 
 mollusks (p. 85). 
 
 ROTHOMAGE'NSIS Lat. from rotho- 
 ma'gum, a temple of Roth, a di- 
 vinity of that part of Gaul, now 
 called Normandy ; hence too the 
 name of the city Rouen. Belong- 
 ing or relating to Rouen. Specific 
 name of an ammonite. 
 
 ROTHE-TODTE-LIEGENDE Ger. New 
 
 red sandstone (note, p. 47). 
 
 ROTA'TA Lat. Rotate; wheel- 
 shaped. 
 
 ROTU'NDUS Lat. Round. 
 
 RUBBLE Angular and broken frag- 
 ments of subjacent rock lying be- 
 neath the superficial mould. 
 
 RUDI'STES fr. lat. rudis, unacquaint- 
 ed, because the characters of the 
 animal were unknown. Name of 
 a family of extinct mollusks in the 
 shells of which neither the hinge, 
 the ligament of the valves, nor the 
 muscle of attachment is discover- 
 able. The family contains six 
 genera : Spherulite.s, Radiolites, 
 Calceola, Birostrites, Distinct, and 
 Crania. 
 
 RC'GOSA Lat. Rugose, wrinkled. 
 
 RUGOSITY A wrinkling. 
 
 RUMINA'NTIA Order of mammals 
 which chew the cud. 
 
 RUMINANTS Animals that chew the 
 cud. 
 
 RYA'COLITE (p. 120). 
 
 SACCHAROID fr. lat. saccharum, 
 sugar, and gr. eidos, resemblance. 
 Resembling loaf-sugar. 
 
 SAL-AMMONIAC A compound of 
 ammonia and hydrochloric acid. 
 Muriate of ammonia. 
 
 SALI'FEROUS FORMATION (p. 47). 
 
 SALT Any combination of an acid 
 with a saliiiable substance. 
 
 SANDALI'NA Lat. Sandal-like. 
 
 SANDSTEIN Ger. Sandstone. 
 
 SANDSTONE Any rock consisting of 
 aggregated grains of sand. 
 
 SAU'RIANS fr. gr. sauros, a lizard. 
 Animals of the lizard tribe. 
 
 SAUROID fr. gr. sauros, a lizard, ez- 
 dos, resemblance. Resembling a 
 lizard. 
 
 SAXI'GENOUS fr. lat. saxum, rock, 
 and gr. geinomai, I produce. Rock 
 producing ; rock forming. 
 
 SCA'BRA Lat. Rough. 
 
 SCAPIII'TES fr. gr. skapke, a boat. 
 The boat ammonite (p. 73). 
 
 SCHIST Ger. fr. gr. schistos, split. 
 Slate. 
 
 SCHISTO'SE Slaty. 
 
 SCO'RI^ Lat. plur. of scoria, dross. 
 Volcanic cinders. Cinders and 
 slags of basaltic lavas of a reddish 
 brown and black colour. 
 
 SCORIA'CEOUS Of the nature of 
 scoria?. 
 
 SCO'RIFORM In form of scoriae. 
 
 SEAMS Thin layers or strata inter- 
 posed between others. 
 
 SECONDARY FORMATION (p. 36). 
 
 SECRETED Separated by the action 
 of organs. 
 
 SE'DIMENT fr. lat. sedeo, I sit, that 
 which subsides, or settles to the 
 bottom of any liquid ; dregs. 
 
 SEDIME'NTART Belonging or relat- 
 ing to sediment. 
 
 SEL'ENITE A variety of gypsum. 
 
 SELLA Lat. A saddle. 
 
 SEMICRT'STALLINE Partly crystal- 
 line. 
 
 SENSIBLY Perceptibly. 
 
 SE'PIA A kind of paint or ink pre- 
 pared from the cuttle-fish. 
 
 SEPTA Lat. plur. of septum. 
 
 SEPTA'RIA Flattened balls of stone, 
 which have been more or less 
 cracked in different directions and 
 cemented together by mineral mat- 
 ter which fills the fissures." 
 
232 
 
 GLOSSARY. GEOLOGY. 
 
 SEPTUM Lat. A partition. 
 
 SERIATE' Lat. fr. seria, ajar. Jar- 
 like. 
 
 SER'PENTINE A magnesian rock of 
 various colours and often speckled 
 like a serpents back. It is gene- 
 rally dark green. 
 
 SER'PULA fr. lat. serpo, I creep. A 
 genus of anneli'dans which inhabit 
 a calcareous tube, usually adherent 
 to the shells of mollusks. 
 
 SES'SILE fr. lat. sessilis, dwarfish. 
 Without a pedicle or support. 
 
 SHALE An indurated slaty clay, or 
 clay-slate. 
 
 SHIITGLE Loose, water-worn gravel 
 and pebbles. 
 
 SIGILLA'RIA fr. lat. si'gillum, a 
 seal. Fossil plants found in the 
 coal formation. 
 
 SI'LEX fr. gr. chalis, a pebble. The 
 principal constituent of quartz, rock- 
 crystal, flint, and other silicious 
 minerals. 
 
 SI'LICA Silicious earth ; the oxide of 
 silicon (the elementary basis of si- 
 lica), constituting almost the whole 
 of silex or flint. It combines with 
 many of the metallic oxides, and 
 is hence sometimes called sili'cic 
 acid. 
 
 SI'LICATE A compound of silicic 
 acid and a base ; silicate of iron is 
 a compound of silicic acid and 
 oxide of iron ; plate-glass and win- 
 dow-glass are silicates of soda and 
 potassa, and flint-glass is a similar 
 compound with a large addition of 
 silicate of lead. 
 
 SILI'CIOUS Containing silica. 
 
 SILI'CIFIED Petrified or mineralized 
 by silicious earth. 
 
 SILT The name given to the sand, 
 clay, and earth which accumulate 
 in running waters. 
 
 SILU'RIAIT STSTEM Series of rocks 
 formerly known as the greywacke 
 series (p. 28). 
 
 SIITUA'TA Lat. Hollow, excavated. 
 
 Si'srus Lat. A hollow or excava- 
 tion. 
 
 SINUO'SITT A hollow, an irregular, 
 winding excavation or hollow. 
 
 SI'PHOW fr. gr. siphon, a tube. A 
 cylindrical canal, perforating the 
 partitions of multilocular shells. 
 
 SI'PHUNCLE A small siphon. 
 
 SLATE A well known rock, which 
 is divisible into thin plates or 
 layers. 
 
 SOCIA'LIS Lat. Social ; relating to 
 companions. 
 
 SOLFATA'RA It. A volcanic vent 
 emitting sulphur and sulphurous 
 compounds (p. 115). 
 
 SOLEM Lat. The sun. 
 
 SOMMA It. (p. 103). 
 
 SPATA'NGUS fr. gr. spataggos, a spe- 
 cies of echinus. A genus of sea- 
 urchins, having the mouth situated 
 laterally, and but four rows of 
 pores. 
 
 SPECIES A kind ; a subdivision of 
 genus. 
 
 SPECIFIC "WEIGHT, or SPECIFIC GRA- 
 VITY The relative weight of one 
 body with that of another of equal 
 volume. 
 
 Sp;Eifo'pTERis fr. gr. sphen, a 
 wedge, pteris, a fern. A genus of 
 fossil plants. 
 
 SPHE'NOPHT'LLITES fr. gr. sphen, 
 wedge, phullon, leaf, lithos, stone. 
 A family of fossil plants. 
 
 SPHE'RULITES fr. gr. sphaira, a 
 sphere, lithos, a stone. A variety 
 of obsidian or pearlstone which 
 occurs in rounded grains. 
 
 SPINO'SA 7l jat ' Spinous; covered 
 
 SPIXO'SUM 5 with spines. 
 
 SPI'RIFER (p. 30). 
 
 STALA'CTITES fr. gr. stalasso, I drop. 
 Conical concretions of carbonate of 
 lime attached to the roofs of calca- 
 rious caverns, and formed by the 
 gradual dropping of water holding 
 the carbonate in solution. 
 
 STALA'GMITES Stalactical forma- 
 tions of carbonate of lime, found 
 on the floors of calcareous caverns. 
 
 STAU'HOTIDE fr. gr. stauros, a cross, 
 eidos, form. Cross-stone. Pris- 
 
GLOSSARY. GEOLOGY. 
 
 233 
 
 matic garnet. It is very abundant 
 in New England. 
 
 STELLAS Lat. Stars. 
 
 STIGMA'RIA fr. gr. stigma, an im- 
 pression. A vegetable fossil (p. 42). 
 
 STHA'TA Lat. plur. of stratum. 
 
 STRA'TUM Lat. A layer, a bed. 
 
 STRATTFICA'TION An arrangement 
 in beds or layers. 
 
 STRA'TIFIED Arranged in strata. 
 
 STRIPS Lat. Diminutive channels 
 or creases. 
 
 STRIATED Marked with strise. 
 
 STRIKE The direction of strata ; the 
 line of bearing (p. 185). 
 
 SUB Lat. Under. 
 
 SUBAPENNINE Applied to a portion 
 of the pliocene strata. Low hills 
 which border the Apennines. 
 
 SUBLIMA'TION The process by 
 which volatile substances are raised 
 by heat, and again condensed into 
 the solid form. The substances so 
 obtained are called sub'limates. 
 
 SUBMARINE Beneath the sea. 
 
 SUBMERGED Immersed or covered 
 by water. 
 
 SUBPLICA'TA Lat. Somewhat plait- 
 ed. 
 
 SUBSIDENCE (p. 99). 
 
 SUBSTRATUM An under-layer or 
 bed. 
 
 SULCA'TA } Lat. Sulcate ; grooved 
 
 SULCA'TUS 3 or furrowed. 
 
 SULPHATISA'TION The act of con- 
 verting into compounds containing 
 sulphur. 
 
 SUL'PHURET A compound of sul- 
 phur with an other solid. 
 
 SULPHU'RIC ? Relating to sulphur. 
 
 SULPHUROUS 3 Applied to acids 
 composed of sulphur and oxygen. 
 
 SUPERPOSED fr. lat. super, above, 
 pono, I place. Placed above. 
 
 SYENITE and SIENITE A granitic 
 rock from Syene or Siena, in Egypt. 
 It consists of quartz, feldspar and 
 hornblende. It is tougher than 
 granite and a more durable building 
 stone. 
 
 SYNCLINAL fr. gr. sun, with, klinein, 
 to incline. Synclinal axis (p. 160). 
 20* 
 
 STSTEM OF UPHEAVAL (p. 189 and 
 191). 
 
 TABULAR In form of a table; hori- 
 zontal. 
 
 TALC A foliated magnesian mineral 
 of an unctuous feel, often used for 
 tracing lines on wood, cloth, &c. 
 which are not so easily effaced as 
 those of chalk. 
 
 TAL'COSE Of the nature of talc. 
 
 TA'LUS A sloping heap of fragments 
 accumulated at the foot of a steep 
 rock. 
 
 TEMPERATURE A definite degree of 
 sensible heat. 
 
 TENDON f. gr. teino, I stretch. A 
 fibrous cord at the extremity of a 
 muscle, by which the muscle is 
 attached to a bone. 
 
 TEREBE'LLUM fr. lat. terebro, I bore. 
 A genus of gasteropod mollusks. 
 
 TEREBRA'TULA (p. 30). 
 
 TER'MINAL Belonging to the end. 
 
 TERTIARY FORMATION (p. 77). 
 
 TESTA'CEOUS fr. lat. testa, a shell. 
 Consisting of carbonate of lime and 
 animal matter. 
 
 TESTUDINA'RIA A tribe of chelonian 
 reptiles. 
 
 THE'RMAL fr. gr. therme, heat. 
 Warm, hot. 
 
 THE'RMOMETER fr. gr. therme, heat, 
 metron, measure. An instrument 
 for measuring heat. . 
 
 THIN OUT Strata are said to thin 
 out when they diminish in thickness. 
 
 TISSUE fr. lat. tela, a web. A web, 
 or web-like structure, constituting 
 the elementary structures of ani- 
 mals and plants. 
 
 TRA'CHYTE fr. gr. trachus, rough. 
 A variety of lava. A feldspathic 
 rock, which often contains glassy 
 feldspar and hornblende. When 
 the feldspar crystals are thickly and 
 uniformly disseminated, it is called 
 trachytic porphyry. 
 
 TRANSITION FORMATION (p. 26). 
 
 TRAP From the Sweedish trappa, 
 a flight of stairs, because trap rocks 
 frequently occur in large tabular 
 masses rising one above another 
 
234 
 
 GLOSSARY. GEOLOGY. 
 
 like the successive steps of a stair 
 case. Applied to certain igneous 
 rocks composed of feldspar, augite 
 and hornblende. 
 
 TRA'PPEAN Relating to trap rocks. 
 
 TRAPEZOIDAL In form of a trape- 
 zium. 
 
 TRA'VERTIN fr. it. travertino. Lime- 
 stone deposited from water holding 
 carbonate of lime in solution. It is 
 found in the sweet springs of Vir- 
 ginia, and at the hot springs of the 
 Washita, in Arkansas, as well as in 
 many other places. 
 
 TRE'MOLITE A mineral, often of a 
 fibrous structure, generally contain- 
 ing si'lica, magnesia, and carbonate 
 of lime, originally found in the 
 valley of Tremola on St. Gothard. 
 
 TRENCHANT Cutting. 
 
 TRIAS fr. lat. tres, three (p. 49). 
 
 TRIA'SSIC Of the nature of trias. 
 
 TRIGONA'LIS Lat. fr. gr. treis, three, 
 gonia, angle. Having three angles 
 or corners. 
 
 TRIGO'NIA fr. gr. trigonos, three- 
 cornered. A genus of bivalve mol- 
 lusks most of which are extinct. 
 
 THIGO'NULA Lat. Having three 
 little angles. 
 
 TRILOBITE (p. 28). 
 
 TRITURA'TION fr. \&t.tritus, rubbed. 
 The act of rubbing or grinding. 
 
 TRUNCATE Terminating very ab- 
 ruptly, as if a portion had been cut 
 off. 
 
 TRUNCA'TUS Lat. Truncate. 
 
 TU'FA It. A volcanic rock, com- 
 posed of an agglutination of frag 
 mented scorise. 
 
 TURBO Lat. A twisting. A genus 
 of univalve gasteropods. 
 
 TURBINA'TA 7 Lat. Shaped like a 
 
 TURBINA'TUM 5 top. 
 
 TURRI'CULATED Resembling a tower 
 with turrets. 
 
 TURRILITES (p. 73). 
 
 TURRITE'LLA Lat. A little tower 
 or turret. A genus of gasteropods 
 
 UNCONFORMABLE STRATIFICATION 
 (p. 185). 
 
 JNDULA'TION A wave ; arranged in 
 a wave-like manner. 
 
 [JNDULA'TUS Lat. Waved; hav- 
 ing a waved surface. 
 
 UNILO'CULAR fr. lat. unus, one, lo- 
 culus, partition. Having but one 
 chamber or compartment. 
 
 U'NIO Lat. A pearl. A genus of 
 mussels. 
 
 UNIONES plur. of unio. 
 
 UNSTRATIFIED Not stratified. 
 
 UPHEAVAL (p. 99). 
 
 UPTILTED Tilted up ; raised at one 
 end. 
 
 URSUS Lat A bear. 
 
 VALLEYS OF DISLOCATION (p. 164). 
 
 VALLETS OF ELEVATION (p. 161). 
 
 VA'RIANS Lat. Varying, chang- 
 ing. 
 
 VAS'CULAR Containing numerous 
 
 VEGETATIVE LIFE Life of nutrition. 
 VEGETABLE EARTH (p. 14). 
 VEINS (p. 118). 
 VE'NERICA'RDIA fr.Venus, and ca'r- 
 
 dium. A genus of bivalve mol- 
 
 lusks. 
 VENTRICO'SA Lat. Ventricose ; in- 
 
 flated, swelled in the middle. 
 VE'RTEBRA fr. lat. vertere, to turn. 
 
 A joint or bone of the spine. 
 VE'RTEBRA Plur. of vertebra. 
 VE'RTEBRAL COLUMN The spine or 
 
 back-bone. 
 VER'TETBATE Having vertebrae, or 
 
 a spine. 
 VESICULA'RIS Lat. Vesicular ; con- 
 
 taining vesicles. 
 VI'RGULA Lat. A little rod. 
 VI'RIDIS Lat. Green. 
 VI'TREOCS fr. lat. vitrea, glass. Re- 
 
 sembling glass. 
 VI'TREO-HES'INOUS Partaking of 
 
 the nature of glass and resin. 
 VO'LATILE fr. lat. volo, I fly. Capa- 
 
 ble of assuming the state of vapour, 
 
 and flying off. 
 VOLA'TILIZE To become volatile. 
 
 VOLGA 'NIC Relating to a volcano. 
 
GLOSSARY. GEOLOGY. 
 
 235 
 
 VOLT'ZIA A genus of fossil co'nifers. 
 VOIU'TA Lat. A whorl. A genus 
 
 of gasteropods. 
 VO'SGEAN Belonging or relating to 
 
 VULGA'RIS Lat. Common. 
 WAL'CHIA A genus of fossil co'nifers 
 
 (p. 43). 
 WEALD Name of a part of Kent 
 
 and Surrey in England. 
 WEALDEIT DEPOSIT (p. 69). 
 
 WHINSTONE A Scotch name for 
 greenstone and other trap rocks. 
 
 ZA'MIA fr. gr. zemia, loss or damage. 
 A genus of the order Cyca'dese plants. 
 
 ZECHSTEIIT Ger. A magnesian 
 limestone, lying under the red 
 standstone. 
 
 ZO'OPHTTE fr. gr. zoon, an animal, 
 phuton, plant. A plant-animal, 
 which seemingly partakes of the pro- 
 perties of both plants and animals. 
 
 THE END, 
 
NEW AND IMPORTANT SCHOOL BOOKS. 
 
 TO TEACHERS, PRINCIPALS AND CONTROLLERS 
 
 OF SCHOOLS, ACADEMIES AND COLLEGES 
 
 We take the liberty of calling your attention to a Series 
 of Books on the subject of Natural History, which, in the 
 opinion of many of the most eminent men in our country, 
 is second to no branch of knowledge now taught in schools. 
 We ask your attention to these books, because we believe 
 them to be superior to any works of the kind ever offered 
 to the American public. They are small in size, extremely 
 cheap, as accurate in scientific arrangement as the most 
 voluminous works on similar subjects, and in every respect, 
 such as parents and teachers would wish to place in the 
 hands of their children. In confirmation of this opinion of 
 the worth of these works, we respectfully invite your 
 attention to the following testimonials. 
 
 Very respectfully, your obedient servants, 
 
 GRIGG & ELLIOT, 
 No. 9 North Fourth Street, Philad'a 
 
 These books have been introduced into the Public Schools of Pennsylvania 
 and Ohio, and no doubt will, ere long, be introduced into all the public schools 
 of our other States. 
 
 "We regard the introduction of these works into our public schools, among the 
 highest compliments they have received ; for we feel sure that the gentlemen 
 who constitute the committee for selecting books, possess too much discernment 
 and general knowledge, to pass favourably upon works of inferior pretensions. 
 The following gentlemen composed the Committee for selecting books for the 
 use of Public Schools." GEORGE M. W BARTON, Esq. 
 
 THOMAS H. FORSYTH, Esq. 
 GEORGE EMLEN, Jr., Esq. 
 FRANCIS LYONS, Esq. 
 JOHN C. SMITH, Esq. 
 Philadelphia. 
 
 In addition to the following flattering notices of the American Press, the pub- 
 iishers have received upwards of one hundred recommendations from the most 
 prominent professors and distinguished teachers of our country, to the superior 
 claims of these works, and urging their introduction as Class Books into all the 
 Schools. Academies, &c., throughout the United States. 
 
RTTSCHENBERGER'S SERIES. 
 
 FIRST BOOKS 
 
 OF 
 
 NATURAL HISTORY, 
 
 SCHOOLS, COLLEGES, AND FAMILIES. 
 
 1. ELEMENTS OF 
 
 ANATOMY AND PHYSIOLOGY. 
 
 2. ELEMENTS OF 
 
 MAMMALOGY, 
 
 The Natural History of Quadrupeds. 
 
 3. ELEMENTS OF 
 
 ORNITHOLOGY, 
 
 The Natural History of Birds. 
 
 4. ELEMENTS OF 
 
 HERPETOLOGY AND ICHTHYOLOGY, 
 
 The Natural History of Reptiles and Fishes. 
 
 5. ELEMENTS OF 
 
 CONCHOLOGY, 
 
 The Natural History of Shells aud Mollusc a. 
 
 6. ELEMENTS OF 
 
 ENTOMOLOGY, 
 
 The Natural History of Insects. 
 
 7. ELEMENTS OF 
 
 BOTANY, 
 
 The Natural History of Plants. 
 
 8. ELEMENTS OF 
 
 GEOLOGY, 
 
 The Natural History of the Earth's Structure. 
 
 This interesting series of books has already met with the most 
 flattering reception ever extended to any work issued from the Amer- 
 ican press. Introduced into the Public Schools of Pennsylvania, and 
 in nearly all the first class seminaries of learning in the United States. 
 
RECOMMENDATORY NOTICES. 
 
 " Ruscbenberger's Series of Boohs on Natural History, are among the 
 most valuable and useful works, for the use of Schools that have ever been 
 published. A knowledge of Natural History, is not only valuub'e, but 
 deeply interesting-; and no one's education can, with such faciliiies as these 
 works afford, be considered complete without it." Nntional Intelligencer. 
 
 "These are the mo-t valuable additions of the day to our stock of School 
 Books. The avidiiy with which they have been seized upon is unprece- 
 dented. Though the first vol. was published for the first time only a few 
 months ago, it has already gone through its fifth edition; the second is fol- 
 lowing close upon its heels; and the third prorni es even to be more popular 
 than either of the other two. These books have been adopted by the * hoyal 
 Council of Public Instruction,' for the use of Schoo's throughout France. 
 They are recommended and have been adopted by some of the most emi 
 nent teachers in the United States." Southern Literary Messenger. 
 
 From " The Ladies' Companion, a Monthly Magazine." June, 1842, New York. 
 W. Snowden, 109, Fulton Street. 
 
 "RuscHENBERGEn'a ORNITHOLOGY: Grigg & Elliot. This is an excel, 
 lent book, by one who shows himself perfectly qualified for the task he has 
 undertaken, which is the publishing of a series of works on the different 
 branches of education, for the use of schools and colleges. The present 
 issue is a general and synoptical view of Ornithology, one of the most 
 interesting subjects in Natural History, and will be found of great service, 
 both to teacher and student." 
 
 " This is a compendious, and, as it seems to us. a judiciously compiled 
 treatise on Ornithology, and one well calculated for the use of Schools ; for 
 which object it is intended." N. Y. Courier and Enquirer. 
 
 " In the work before us, the plan is happily carried out. In its small 
 compass it embraces an immense amount of useful and interesting infor- 
 mation." Buffalo Adv. and Journal. 
 
 "Ornithology. This is evidently, like its predecessors, an excellent work 
 of instruction; and ha-s been, in all respects well got up by the publishers." 
 Pennsylvanian, 
 
 "A valuable little work, and is divided up and classified admirably. The 
 glossary, giving the derivation of the names of birds, is of itself worth the 
 price of the volume." New York Aurora. 
 
 "An exceedingly interesting, and very instructive book, and one which 
 possesses special Attraction for young ludies." Baltimore Sun. 
 
 "RusciiENBKRGER's SERIES : Second BooTf. A highly useful and instructive 
 school book. Third Book, This we consider as decidedly an acquisition 
 to our list of school books, the subject is treated of in such a plain style as 
 to be adapted to the simplest capacity. Altogether we think the above 
 series as worthy to take a high and permanent place among our school 
 books " Buffalo Democrat. 
 
 " We wish we could induce our teachers generally to examine this, as 
 well as the earlier works of Dr. Ruschenberger ; they are admirably 
 arranged, and just the very books needed for schools. The work before 
 us on the Natural History of Birds is an admirable one, and no teachel 
 liould neglect to introduce the series. ' Cincinnati Gazette. 
 
 "It is an excellent text book of an interesting science, comprising much 
 knowledge in a brief space, presented in a clear style and with lucid 
 arrangement. Dr. Rnschenbergcr, who has already achieved a high charac 
 icr in the literary world, is acquiring additional claims by his exertions i 
 the field of Natural Science. Spectator, Washington City. 
 
RECOMMENDATORY NOTICES. 
 
 u Ruschenberger's Series. These volumes are constructed upon a new 
 and admirable plan, combining great simplicity of arrangement, with a 
 perspicuity and sententiousness of style seldom found in works of this 
 class; and which has elicited the highest encomiums of upwards of thirty 
 of the leading professors of the country, whose opinions have again been 
 endorsed by most of the public prints." U. Slates Adv. 
 
 "The developement of the principles of classification, is among the very 
 best we have ever seen. Science is here dressed in her own native sim- 
 plicity and beauty, so that the philosopher may admire, while the child may 
 acquire it. Medical Reporter. 
 
 " It is a choice, and well digested work." Atlas. 
 
 " An excellent publication adapted to the youthful mind, and a great help 
 to the mure matured." Mercury. 
 
 "The study of Natural History though generally neglected in schools, 
 is of undoubted use : the present work contains a great amount of infor. 
 mation within a small compass, and properly condenses it for the young 
 mind." N. Y. Journal of Commerce. 
 
 " Ruschenberger's Series. The subjects are Well treated, and from the 
 exceediiig cheapness, and admirable arrangt meu; of these elementary works, 
 they are well fitted for general use in public schools and academies." 
 New York American. 
 
 " We do not hesitate to say, that this is the best work of the kind and 
 dimensions, that has even fallen under our notice. We hope all will embrace 
 the first opportunity of procuring a copy, as we are sure they will prize 
 it highly." Botanic Recorder. 
 
 " A well digested and curefu'ly arranged abstract of the most interesting 
 parts of Natural Science." Philadelphia Gazette 
 
 " Admirably adapted to convey an elementary knowledge on the subject 
 of which it treats; and will be found an excellent book for the student." 
 Public Ledger. 
 
 " Valuable in every respect, it contains a vast amount of information, 
 condensed into an available form, for the use of schools." Spirit of the Times, 
 
 "Just such a work as is wanted for elementary instruction, in this pleas- 
 ing branch of science." New York Evening Post. 
 
 " We regard this series as eminently useful, supplying adequately the 
 instruction in natural history necessary to a proper school education." 
 North American. 
 
 " It is an excellent little work for the purpose designed, written in a cl ar 
 and familiar style, and will not fail to facilitate the studies of those who 
 wish to make themselves acquainted with the subject." Saturday Courier. 
 
 "Admirably adapted for elementary instruction." Saturday Chronicle. 
 
 " We have great pleasure in recommending it as an excellent elementary 
 manual on the subject " Medical Examiner. 
 
 "Ornithology This book is equal in merit to the first and second, and 
 is a most valuable work. It is intended for the use of schools and acade- 
 mies, and we would call the attention of parents and others to the series of 
 books to which this belongs, assuring them at the same time, that it will 
 answer the purpose for which it is intended, better than any other work of 
 the kind that we ever saw, or, in our opinion, that was ever published in 
 this country. It is divided into questions and answers, contains an exten- 
 sive and valuable Glossary, and is illustrated by eight Plates ; and what is 
 more the price is so very low that every person can aflord to purchase it. 
 Yoik New Era. 
 
 .T~: 4 
 
NEW SERIES 
 
 OF 
 
 ENGLISH SCHOOL BOOKS. 
 
 PUBLISHED AND FOR SALE BT 
 
 GRIGG & ELLIOT, 
 
 NO. 9 NORTH FOURTH STREET, PHILADELPHIA. 
 
 And for Sale by Booksellers and Country Merchants generally in the U. S. 
 
 To Teachers, Principals and Controllers of Schools, Academies 
 and Colleges throughout the United States. 
 
 Philadelphia, 9 North Fourth Street. 
 
 SIR: Believing that you take an interest in educational im- 
 provements, we beg leave to call your attention to an admirable 
 series of School Books on Natural History, prepared by Dr. Rus- 
 chenberger. There have hitherto been few works, if any, on this 
 subject, suited to the capacity of pupils at an early age. The 
 series referred to has, therefore, met with a most cordial reception 
 throughout the country, from teachers, naturalists, and men of 
 letters. The volumes are eight in number the first being de- 
 voted to Anatomy and Physiology ; the second to Mammalogy ; 
 the third to Ornithology ; the fourth to Herpetology and Ichthy- 
 ology ; the fifth to Conchology ; the sixth to Entomology ; the 
 seventh to Botany ; and the eighth to Geology. They are small in 
 size, extremely cheap, as accurate in scientific arrangement as the 
 most voluminous works on similar subjects, and in every respect 
 such as intelligent parents would wish to place in the hands of 
 their children. Each work is entirely independent of the others. 
 The retail price is only fifty cents per volume for the first seven 
 volumes. Orders sent to us directly, or through any bookseller, 
 or country merchant, will be promptly attended to. 
 
 Respectfully, your obedient servants, 
 
 GRIGG & ELLIQT. 
 1 
 
CRICC & ELLIOT, 
 
 Publish the following valuable list of SCHOOL BOOKS, which consti- 
 tute a regular series of ELEMENTARY WORKS, designed for the use of 
 COLLEGES, ACADEMIES, and SCHOOLS, also for family use. 
 
 The publishers hope that all TEACHERS who have their pupils' in- 
 terest at heart, will examine these valuable series of School Books before 
 introducing any others; and they particularly request that all TEACHERS 
 and DIRECTORS of our PUBLIC SCHOOLS in the various states will 
 examine G. & E.'s new SERIES of COMMON SCHOOL READERS, 
 and their other School Books before introducing any others. 
 
 TO TEACHERS AND SCHOOL COMMITTEES, 
 
 RUSCHENBERGER'S popular series of SCHOOL BOOKS on Natural 
 History, prepared for the use of Schools, by Dr. W. S. W. Ruschenberger, 
 from the text of Milne, Edwards, &c. 
 
 1, Elements of Anatomy and Physiology, - - 45 cuts. 
 
 2, Elements of Mammalogy, - - - - 75 " 
 
 3, Elements of Ornithology, - - - - 81 " 
 
 4, Elements of Herpetology and Ichthyology, - 66 " 
 
 5, Elements of Conchology, - - - v ( - 119 ' 
 
 6, Elements of Entomology, - - - - - 91 " 
 
 7, Elements of Botany, - - - - - - 194 " 
 
 8, Elements of Geology, about - - - - - 300 " 
 
 Each book of the series is complete in itself, and has a full glossary ap- 
 pended. The illustrations are numerous, and beautifully executed. Teach- 
 ers are respectfully invited to call and examine these works before selecting 
 for their schools any books on Natural History, these being very cheap, and 
 having been approved by distinguished and scientific men. 
 
 Among the very numerous notices received from all parts of the United 
 States, the publishers subjoin the following: 
 
 " We have no handbooks equal to these, and we think Dr. R. has con- 
 ferred an obligation upon teachers and learners, by producing them in an 
 English dress, with all the advantages of well engraved illustrations. The 
 whole set of this work, which is furnished at a low price, will prove an in- 
 valuable acquisition to the school library." 
 
 " Dr. Ruschenberger' s series of books on Natural History. We have hastily 
 glanced over the first four numbers, and have profited much by their peru- 
 sal. Besides being a complete system, the different subjects are treated in 
 a concise and elegant style by the author. The work is peculiarly adapted 
 to the use of our District Schools, and when we see this important branch 
 of general education so much neglected, we would urge upon our directors 
 to examine Dr. Ruschenberger's Series, and place it where in justice it 
 should be, in every district school in the country." 
 
 "These 4 First Books 1 of D*r. R. have been everywhere received with 
 great and deserved commendation, and they will be found well to merit the 
 attention of teachers throughout the United States, as furnishing a means 
 
GRIGG & ELLIOT'S SCHOOL BOOKS. 3 
 
 of instruction not otherwise to be met with, upon subjects of the utmost 
 importance to a course of liberal education. 
 
 " We have, from the same publishers, a set of their series of ' Common 
 School Readers' 1 four in all, arranged progressively of which, we under- 
 stand, that no less than 70,000 have been sold in a short period, a fact 
 affording conclusive evidence of the estimation in which these reading 
 books are held. These volumes are so arranged as to bring the learner 
 forward from matters of simple information to subjects of high interest in 
 morals and history, and are well calculated, not only to instruct at the 
 time, but likewise to create a fondness for the acquisition of knowledge." 
 
 "Our Booksellers have just received complete sets of Dr. Ruschenber- 
 ger's elementary works on Natural History, for ihe use of schools and col- 
 leges, and to which we would call the attention of those having the instruc- 
 tion of our youth in charge. The style of the author appears to be clear 
 and succinct, and the various subjects are illustrated by appropriate draw- 
 ings. We learn that Dr. R.'s works have been introduced into the public 
 schools of Pennsylvania, Ohio, .Mississippi, and other States, and in nearly 
 all the first class seminaries of learning in the United States, and have 
 always met with a reception truly flattering. 
 
 "In addition, they have for sale Grigg~& Elliot's new series of Com- 
 mon School Readers. We have not time to examine them thoroughly, but 
 to judge from the many encomiums they have received from the high- 
 est sources, we should think they were destined to occupy a high place 
 in the esteem of those interested in the cause of education." New Orleans 
 Picayune, Jan. 4, 1845. 
 
 New and Valuable School Books. " In view of the long list of recommen- 
 dary notices by many of the most distinguished teachers in the Union, and 
 by a cursory examination ourselves, we can cheerfully declare thai no 
 TEACHER or SCHOOL should be without this series of school books. 
 We invite all those interested to call at Davis' and examine them, where 
 they are for sale, wholesale and retail at very low prices." Indiana State 
 Journal, Indianapolis. 
 
 "Messrs. Grigg & Elliot, Philadelphia, have published an interesting 
 series of books, which we commend to the attention of TEACHERS. A 
 series of Readers, adapted to successive classes, which seem. to us well se- 
 lected and arranged. A far more important series, and one long called for, 
 in the shape of elementary scientific treatises on the following subjects: 
 Mammalogy, Ornithology, Herpetology and Ichthyology, Botany, Concholo- 
 gy, Anatomy and Physiology, and Geology. These works are prepared by 
 Dr. Ruschenberger, on the plan and materials of similar books used in Ihe 
 public schools of France. They are illustrated with the necessary plates, 
 and are complete in their treatment of the subject, and undoubtedly deserve 
 a place in our now meagre list of elementary class books of science. These 
 works are for sale by M'Carter& Allen, Charleston, S.C., Allen, M'Carter & 
 Co., Columbia, and Thomas Richards, Augusta, Ga." Charleston Mercury. 
 
 The publishers have just received, for one school, in Bangor, Maine, an 
 order for seventy-five copies each of the above valuable works, which is an 
 evidence of the high estimation in which they are held in that section of 
 country, by some among the best teachers in New England. 
 
4 GRIGG & ELLIOT'S SCHOOL BOOKS. 
 
 Portland, August 22, 1845. 
 
 DEAR SIR : Your note, accompanying Dr. Ruschenberger's Elementary 
 Books on Natural History, for the use of schools, &c., was duly received, 
 for which please accept, for yourself and the publishers, my sincere thanks. 
 
 Having examined several of the volumes, I take great pleasure in ex- 
 pressing my approbation of the work. It is better adapted to the purposes 
 of elementary instruction than any other cheap work with which I am ac- 
 quainted. 
 
 Among its many merits I regard that of the constant adherence of the 
 author to the language of science as peculiarly worthy of notice. Although 
 the descriptions of the various objects treated of may appear obscure at 
 first sight, every difficulty is removed by the copious glossary which ac- 
 companies each volume. While the student is acquiring accurate instruc- 
 tion in natural history, he is, at the same time, and with no additional 
 labour, adding essentially to his vocabulary. 
 
 With these remarks I would most cordially recommend the work as well 
 adapted to fulfil the objects for which it is published. 
 
 With much respect yours truly, 
 
 J. W. M1GHELS, 
 
 Member of the Natural History Societies in Boston and Portland, also of the 
 American Association of Geologists, <S(-c. <fc. 4~c. 
 
 Brunswick, Maine, Sept. 19, 1845. 
 
 Our schools have long felt a want of suitable text books on the several 
 branches of Natural History; but this desideratum has been happily sup- 
 plied by Dr. Ruschenberger's series, published by Messrs. Grigg & Elliot, 
 of Philadelphia. 
 
 These truly scientific, yet cheap works, can scarcely fail of diffusing a 
 more extended taste for those too long neglected branches of education, 
 which, when properly pursued, will breathe new life and vigour into our 
 systems of education. 
 
 Elementary works on Natural History are too often spoiled by an attempt 
 to divest them of scientific terms, thus rendering the simple and-determi- 
 nate language of science a confused and unmeaning gibberish. But these 
 works are a noble exception, simple in their arrangement, and precise in 
 their definitions. Professor PARKER CLEAVELAND, LL. D. 
 
 Bowdoin College, Brunswick, Maine. 
 
 I heartily concur in the above opinion of Dr. R.'s works, and shall use 
 my influence to have them introduced to Brunswick Seminary. 
 
 Yours truly, 
 
 G. C. SWALLOW, A. M. 
 Principal Brunswick Academy, Brunswick, Maine. 
 
 Portland, Aug. 21, 1845. 
 
 DEAR SIRS : Dr. Ruschenberger's series of" First Books of Natural His- 
 tory" is a most valuable acquisition to all classes of readers, especially to 
 the young. 
 
 These classics, admirable in their whole structure and composition, will 
 date a new era in the facilities. to useful instruction in the schools of our 
 country. 
 
GRIGG & ELLIOT'S SCHOOL BOOKS. 5 
 
 Though closed is my course of thirty-five years teaching, I am tempted 
 to begin the work anew with these delightful books as auxiliaries. They 
 should be in the HANDS OF ALL TEACHERS who can instruct, and all 
 pupils who can learn. Yours most truly, 
 
 B. CUSHMAN, A. M. 
 Portland, late Principal of the Academy. 
 
 Illinois College, Sept. 5, 1845. 
 
 It is three years since I first became acquainted with Ruschenberger's 
 Series of First Books of Natural History, and I have examined those of the 
 series which have appeared since that time. I have also used these books 
 in the instruction of my classes in college, and I am happy to state that I 
 consider them as vastly superior, for the purposes of instruction, to any 
 book or series of books on the same subject in our language. I take plea- 
 sure, therefore, in expressing the opinion that the extensive introduction of 
 these books into the courses of instruction in the Colleges of the United 
 States would prove of incalculable advantage to the progress of sound edu- 
 cation among us. 
 
 SAMUEL ADAMS, M. D. 
 
 . Professor of Chemistry and Natural History, Illinois College. 
 I cheerfully concur in the opinion which Dr. Adams has expressed, and 
 shall use the influence I may have to facilitate the introduction of these 
 works into SCHOOLS and PUBLIC SEMINARIES. 
 
 J. M. STURTEVAXT, 
 Jacksonville, Sept. 8, 1845. President of Illinois College. 
 
 Pa. Literary, Scientific, and Military Collegiate Institute. 
 GEKTLEMEN : I have examined, with attention, the First Books of Natu- 
 ral History, by Dr. Ruschenberger, and unhesitatingly express my appro- 
 bation of its superior merits. I think it well adapted to the wants of our 
 Seminaries of Learning generally, and that it should also constitute a part 
 of every private library. As such, I confidently recommend it to the pa- 
 tronage of an enlightened public. 
 
 A. PARTRIDGE, 
 
 Pres. of the Pa. L. S. M. C. Institute. 
 Messrs. GRIGG & ELLIOT, Philadelphia. 
 
 Woodward College, Cincinnati, Ohio. 
 
 GENTLEMEN : I have examined Dr. Ruschenberger's series of school 
 books in the different branches of Natural History. The volumes are, in 
 every respect, exceedingly well got up, and their cheapness will place 
 them within the reach of all classes. 
 
 It is judged expedient to introduce the subject of Natural History amo'ng 
 the studies of our Common Schools. I know not a work so well adapted as 
 Dr. Ruschenberger's, not only by its plainness of style, but by its numerous 
 and excellent engravings. The last are essential to the understanding of 
 such works, and yet their cost has hitherto been so great as to exclude them 
 from common schools. 
 
 The division into volumes, each embracing one department of Natural 
 History, gives the present decided advantage^ over most other productions 
 of a similar character. 
 
 B. P. AYDELOTT. 
 
6 GRIGG & ELLIOT'S SCHOOL BOOKS. 
 
 " Ruschenberger's Series of Books on Natural History, are among the 
 most valuable and useful works, for the use of schools that have ever been 
 published. A knowledge of Natural History, is not only valuable, but 
 deeply interesting; and no one's education can, with such facilities as these 
 works afford, be considered complete without it." National Intelligencer. 
 
 "These are the most valuable additions of the day to our stock of School 
 Books. The avidity with which they have been seized upon is unprece- 
 dented. Though the first vol. was published for the first time only a few- 
 months ago, it has already gone through its fifth edition ; the second is fol- 
 lowing close upon its heels; and the third promises even to be more popu- 
 lar than either of the other two. These books have been adopted by the 
 'Royal Council of Public Instruction,' for the use of Schools throughout 
 France. They are recommended and have been adopted by some of the 
 most eminent teachers in the United States." Southern Literary Messenger. 
 
 "This is a compendious, and, as it seems to us, a judiciously compiled 
 treatise on Ornithology, and one well calculated for the use of Schools; for 
 which object it is intended." N. Y. Courier and Enquirer. 
 
 "RUSCHEXBERGER'S SERIES: Second Book. A highly useful and instruct- 
 ive school book. Third Book. This we consider as decidedly an acquisi- 
 tion to our list of school books; the subject is treated of in such a plain 
 style as to.be adapted to the simplest capacity. Altogether we think the 
 above series as worthy to take a high and permanent place among our 
 school books." Buffalo Democrat. 
 
 "We wish we could induce our teachers generally to examine this, as 
 well as the earlier works of Dr. Ruschenberger ; they are admirably ar- 
 ranged, and just the very books needed for schools. The work before us 
 on the Natural History of Birds is an admirable one, and no teacher should 
 neglect to introduce the series." Cincinnati Gazette. 
 
 " Ruschenberger* s Series. The subjects are well treated, and from the 
 exceeding cheapness and admirable arrangements of these elementary 
 works, they are well fitted for general use in public schools and acade- 
 mies." New York American. 
 
 " We do not hesitate to say, that this is the best work of the kind and 
 dimensions, that has ever fallen under our notice. We hope all will em- 
 brace the first opportunity of procuring a copy, as we are sure they will 
 prize it highly." Botanic Recorder. 
 
 "Admirably adapted to convey an elementary knowledge on the subject 
 of which it treats; and will be found an excellent book for the student." 
 Public Ledger. 
 
 "Valuable in every respect, it contains a vast amount of information, 
 condensed into an available form for the use of schools." Spirit of the 
 Times. 
 
 " Just such a work as is wanted for elementary instruction, in this pleas- 
 ing branch of science." New York Evening Post. 
 
 "We regard this series as eminently useful, supplying adequately the 
 instruction in natural history necessary to a proper school education." 
 North American. 
 
 "It has been justly observed, that ' the double effect of the study of Natu- 
 ral History is to impart certainty to the mind, and religion to the heart,' and 
 
GRIGO & ELLIOT'S SCHOOL BOOKS. 7 
 
 the Christian no less than the man of science, must rejoice in every effort 
 to throw more widely open the sublime and boundless field which it pre- 
 sents. This is the design of Dr. Ruschenberger, in a series of First Books 
 of Natural History, which he is preparing for the use of schools and col- 
 leges." Banner of the Cross. 
 
 " The series have met a demand and sale in France almost unparalleled, 
 and the works are well adapted, not only for schools, bat for popular read- 
 ing and instruction. This work is fro.m the French of Edwards and Comte, 
 and has received the warm commendation of many of the best physicians 
 and scholars in this country." N. York Evening Tattler. 
 
 "It is highly commended by the very best authorities." N. Y. Tribune. 
 
 "This book is highly commended by competent judges, and we there- 
 fore give our solemn opinion that it is an excellent work." Boston Daily 
 Times. 
 
 " We have examined this new book for schools and colleges, with pecu- 
 liar gratification. The style is succinct and clear, and the subject illus- 
 trated by appropriate drawings. We should be glad to see this work 
 introduced into all the schools. It teaches knowledge the most important, 
 which has been, however, strangely overlooked in our school and college 
 system. It is a book which should not be confined to seminaries alone. It 
 may be used with advantage by all individuals in society. We repeat, it 
 is in all respects a most excellent work, and we hope will receive the at- 
 tention and patronage it merits." Brooklyn Evening Star. 
 
 " We are highly pleased with this work. For elementary instruction in 
 families, schools and colleges, it is decidedly superior to anything of the 
 kind we have seen. It gives much valuable information in a very small 
 space, and in style it is generally free from abstruse technicalities. It has 
 already received the highest recommendations from a large number of 
 professional men in different parts of the country ; and it must have, we 
 think, a general circulation. It gives that kind of knowledge which should 
 be diffused among the mass of the people, and it must and will be patron- 
 ized as far as its merits are known." Zion's Watchman. 
 
 "This is a most valuable work, by Dr. Ruschenberger, and most ad- 
 mirably are the plates, representing all the different parts of the body, done. 
 It is cheap, and every parent should place one in the hands of their chil- 
 dren." N. Y. Herald. 
 
 "We have examined this little volume with much pleasure, and think it 
 admirably adapted to the purpose for which it is intended. Animal me- 
 chanism, as a study, has generally been neglected, except by the few, whose 
 profession requires a knowledge of it, and who have time to spare in ac- 
 quiring that knowledge. A prominent cause of the neglect of this useful 
 and interesting science by the general student, is the want of a suitable 
 treatise upon the subject, those extant being too voluminous, technical, and 
 expensive for general use. The little work before us is happily calculated 
 to supply this want. It will, we think, be introduced into our schools and 
 colleges as a text-book, but its circulation ought not to be confined there. 
 Every private library should be considered incomplete without it." N. Y. 
 Mechanic. 
 
 "It seems to us to be well suited for the object for which it is designed, 
 and it will doubtless be introduced into many of our elementary schools." 
 The American Journal of the Medical Sciences. 
 
8 GRIGG & ELLIOT'S SCHOOL BOOKS. 
 
 "The plan and arrangement of the work are admirable, and eminently 
 calculated to facilitate the progress of the pupil. We recommend it to 
 teachers and heads of families." Philadelphia Sat. Chronicle. 
 
 "We cannot too earnestly recommend it to public attention." Cincin- 
 nati Enquirer. 
 
 "The reputation of the author is a guarantee that the work is a good one. 
 On examination w^ find it to be so. It is an admirable compend of the 
 subjects of which'it treats: we should think, indeed, that it would attract 
 the attention of teachers, both from its cheapness, and the admirable man- 
 ner in which it is arranged." Cincinnati Gazette. 
 
 "As far as we are competent to determine, it may safely be welcomed 
 as an important addition to the means of elementary instruction in natural 
 science." The Friend. 
 
 " The Second Book: This number treats of all animals that in infancy 
 feed on the milk of their mothers ; from the human being down to the mus- 
 quito-catching bat. Like the 'First Book,' it is divided into questions and 
 answers, and a glossary ; and is illustrated by six plates. It is as cheap as 
 dirt; and contains an abundance of useful information. There are thou- 
 sands of persons in this country, and millions in Europe, who do not know 
 that whales give milk." New York Era. 
 
 " The series of books of which this forms a part has been highly and 
 justly commended by the ablest judges, as furnishing rare facilities in the 
 acquisition of branches of knowledge, but too much neglected in our 
 schools. We have examined the volumes with much care, and we find 
 them well deserving all the praise bestowed on them." Godey's Lady's 
 Book. 
 
 " Dr. Ruschenberger's series of books on Natural History are among the 
 most valuable and useful works for the use of schools that have ever been 
 published. The text is that of two distinguished French Naturalists, 
 Milne Edwards and Achille Comte translated and prepared for the use 
 of schools and colleges by Dr. Ruschenberger, who deserves great credit 
 for thus devoting his leisure to so useful an object. A knowledge of Na- 
 tural History is not only valuable, but deeply interesting, and no one's edu- 
 cation can, with such facilities as are now offered, be considered complete 
 without it. Simple and comprehensive as the elements of this science 
 have been made by the French professors and Dr. R., and adopted as they 
 should be, in schools and colleges, it would be inexcusable in any youth to 
 be ignorant of these elements, and having acquired them he will find it 
 equally easy and pleasant to enlarge his knowledge by consulting more 
 extended works, and devoting his attention to the study of the various 
 branches of this interesting science. The present book on Ornithology is 
 upon the same plan and possesses the same merit as those that have pre- 
 ceded it, and which have been received with deserved commendation. It 
 is brief and comprehensive, but sufficiently full to give the student a tho- 
 rough knowledge of the elements of Ornithology. It contains also a Glos- 
 sary of the terms used in this branch of Natural History, and a number of 
 wood cuts illustrative of the matter contained in the body of the work." 
 Washington National Intelligencer. 
 
 " We have much pleasure in commending this series of works the 
 third of which now before us, is on Ornithology. It will be found useful 
 in the school-room, or the private .study ."-17. S. Gaz. 
 
NEW AND IMPORTANT 
 
 SCHOOL BOOKS. 
 
 TO TEACHERS, PRINCIPALS AND CONTROLLERS 
 
 OF 
 
 SCHOOLS, ACADEMIES AND COLLEGES, 
 
 SMILEY'S ARITHMETICAL RULES AND TABLES 
 FOR YOUNG BEGINNERS. 
 
 This is the best work of the kind now in print ; but teachers are particu- 
 larly requested to examine for themselves. 
 
 SMILEY'S ARITHMETIC, or the New Federal Calculator, 
 in dollars and cents. This work contains, among other important im- 
 provements, Questions on the Rules and Theory of Arithmetic, which are 
 considered by teachers generally, very conducive to the improvement of 
 the pupil. 
 
 Although a prejudice exists among some teachers in favour of the old 
 works on arithmetic, yet the very liberal patronage which this work has 
 received, must be considered as decisive evidence of the great estimation 
 in which it is held by most of the instructors of youth. Upwards of 300,- 
 000 copies have been printed and sold. The sums being altogether in dol- 
 I-V.T and cents, gives it a decided preference over any other arithmetic in 
 use. The most distinguished teachers of our city and country pronounce 
 it superior to any other like work ; therefore the publisher sincerely hopes 
 this useful improvement will overcome the prejudice that many teachers 
 have to introducing new works, particularly those preceptors who wish to 
 discharge their duty faithfully to parent and child. 
 
 The editors of the New York Telegraph, speaking of Smiley's Arithme- 
 1 
 
2 t GRIGG & ELLIOT'S SCHOOL BOOKS. 
 
 tic, observe, " We do not hesitate to pronounce it an improvement upon 
 every work of that kind previously before the public, and as such recom- 
 mend its adoption in all our schools and academies." 
 
 A KEY TO THE ABOVE ARITHMETIC ; in which all 
 the examples necessary for a learner are wrought at large, and also solu- 
 tions given of all the various rules. Designed principally to facilitate the 
 labour of teachers, and assist such as have not the opportunity of a tutor's 
 aid. By T. T. Smiley, author of the New Federal Calculator, &c. &c. 
 
 CONVERSATIONS ON NATURAL PHILOSOPHY; in 
 
 which the Elements of that Science are familiarly explained. Illustrated 
 with plates. By the author of" Conversations on Chemistry," &c. With 
 considerable additions, corrections, and improvements in the body of the 
 work, appropriate Questions, and a Glossary. By Dr. Thomas P. Jones. 
 
 CONVERSATIONS ON CHEMISTRY; in which the Ele- 
 ments of that Science are familiarly explained and illustrated by Experi- 
 ments and Engravings on wood. From the last London edition. In which 
 all the late Discoveries and Improvements are brought up to the present 
 time, by Dr. Thomas P. Jones. 
 
 The learned and distinguished Professors Silliman and Bigelow, speak- 
 ing of these works, observe: "They are satisfied that the Works contain 
 the fundamental principles, and truths of the Sciences, expressed in a clear, 
 intelligible, and interesting manner, and that the present editions are de- 
 cidedly more valuable than any preceding ones. The high character of 
 the author, as a lecturer, and a man of science, will, we doubt not, secure 
 for these Works the good opinion of the public, and cause their extensive 
 adoption among Seminaries and Students." 
 
 TEACHERS in ordering would do well to say "Jones' Improved Editions." 
 
 THE BEAUTIES OF HISTORY, or Examples of the 
 Opposite Effects of Virtue and Vice, for the use of Schools and Families, 
 with Questions for the Examination of Students. 1 vol. 12mo., with plates. 
 
 This work is introduced into our High School. It is particularly adapted 
 fora Class Book in all our male and female Seminaries, &c. 
 
 " We have received from the publishers, Messrs. Grigg & Elliot, a very 
 neat duodecimo volume, entitled 'The Beauties of History; or, Examples 
 of the opposite effects of Virtue and Vice, drawn from real life.' After a 
 careful examination of this book, we can conscientiously recommend it to 
 parents and teachers as a most meritorious performance. There are here 
 collected, within a narrow compass, the most striking examples of indivi- 
 dual virtue and vice which are spread forth on the pages of history, or are 
 
GRIGG & ELLIOT'S SCHOOL BOOKS. 9 
 
 recorded in personal biography. The noblest precepts are recommended 
 for the guidance of youth ; and in the most impressive manner is he taught 
 to conquer the degrading impulses which lower the standard of the human 
 character. We have not lately met with a volume which, in design and 
 execution, seemed so acceptable as this. The book, moreover, is hand- 
 somely got up, and illustrated with wood engravings." 
 
 GRIMSHAW'S HISTORY OF THE UNITED STATES. 
 
 Recently brought up by the author to the present time. 
 
 Also, Questions adapted to the above History ; and a Key, adapted to the 
 Questions, for the use of Teachers and Private Families. 
 
 GRIMSHAW'S HISTORY OF ENGLAND. Recently 
 brought up by the author to the present time. 
 
 Also, Questions adapted to the above History; and a Key, adapted to the 
 Questions, for the use of Teachers and Private Families. 
 
 GRIMSHAW'S IMPROVED EDITION OF GOLDSMITH'S 
 HISTORY OF GREECE, with a Vocabulary of the Proper 
 
 Names contained in the work, and the Prosodial Accents, in conformity 
 with the pronunciation of Lempriere. 
 
 Also, Questions adapted to the above History; and a Key, adapted to the 
 Questions, for the use of Teachers and Private Families. 
 
 GRIMSHAW'S IMPROVED EDITION OF GOLDSMITH'S 
 HISTORY OF ROME, revised and corrected, and a Vocabulary 
 of Proper Names appended, with Prosodial Marks to assist in their pro- 
 nunciation. 
 
 Also, Questions adapted to the above History; and a Key, adapted to the 
 Questions, for the use of Teachers and Private Families. 
 
 GRIMSHAW'S HISTORY OF FRANCE, with Key and 
 Questions. 
 
 GRIMSHAW'S HISTORY AND LIFE OF NAPOLEON. 
 
 The editor of the North American Review, speaking of these Histories, 
 observes, that "Among the Elementary Books of American History, we 
 do not remember to have seen any one more deserving approbation than 
 Mr. Grimshaw's History of the United States. It is a small volume, and a 
 great deal of matter is brought into a narrow space ; but the author has 
 succeeded so well in the construction of his periods, and the arrangement 
 of his materials, that perspicuity is rarely sacrificed to brevity. 
 
4 GRIGG & ELLIOT'S SCHOOL BOOKS. 
 
 "The chain of narrative is skilfully preserved, and the author's reflec- 
 tions are frequently such as make the facts more impressive, and lead the 
 youthful mind to observe causes and consequences which might otherwise 
 have been overlooked. As a school book it may justly be recommended. 
 
 "What has been said of this volume will apply generally to his other 
 historical works. They are each nearly of the same size as the one just 
 noticed, and designed for the same object, that is, the use of classes in 
 schools. 
 
 "The History of England is an original composition; but the Grecian 
 and Roman Histories are Goldsmith's, improved by Mr. Grimshaw, in 
 which he has corrected the typographical errors, with which the later edi- 
 tions of Goldsmith's Abridgments so much abound; and removed any 
 grossness in language, which, in some few instances, render these valua- 
 ble compends less useful in the schools to which youth of both sexes resort. 
 He has also added a Vocabulary of Proper Names, accentuated, in order 
 to show their right pronunciation, which is a valuable appendage to the 
 History. 
 
 "All these books are accompanied with very full and well-digested 
 Tables of Questions, for the benefit of Pupils, and also with Keys to the 
 same, for the convenience of Teachers." 
 
 [Teachers generally, who have examined Mr. Grimshaw's Histories of 
 the United States and England, and Improved Editions of Goldsmith's 
 Greece and Rome, have given them a decided preference to any other 
 Histories in use as School Books and any person who will examine them, 
 will find about one thousand errors in each corrected; and teachers order- 
 ing those works will do well to say " Grimshaw's Improved Editions."] 
 
 GRIMSHAW'S LADIES' LEXICON, and Parlour Com- 
 panion ; containing nearly every word in the English language, and ex- 
 hibiting the plurals of nouns and the participles of verbs, being also 
 particularly adapted to the use of Academies and Schools. By William 
 Grimshaw, Esq., author of the Gentlemen's Lexicon, &c. 
 
 THE GENTLEMEN'S LEXICON, or Pocket Dictionary; 
 containing nearly every word in the English language, and exhibiting the 
 plurals of nouns and the participles of verbs; being also particularly 
 adapted to the use of Academies and Schools. By William Grimshaw, 
 author of the Ladies' Lexicon, History of England, of the United States, &c. 
 
 " The public are again indebted to the talents of Mr. Grimshaw, for the 
 very useful books which he has called * The Ladies' and Gentlemen's 
 Lexicon.' The peculiarity and advantages of these works may be col- 
 lected from the following portion of the preface. ' They differ from all 
 
GRIGG & ELLIOT'S SCHOOL BOOKS. 5 
 
 preceding works of the kind in this, that they exhibit the plurals of all 
 nouns which are not formed by the mere addition of the letter S, and also 
 the participles of every verb now generally used, and unless accompanied 
 by a particular caution. No word has been admitted which is not now of 
 polite or popular use, and 'no word has been excluded which is required 
 either in epistolary composition or conversation.'" 
 
 In the Nashville Republican, we observe the following notice of this very 
 useful book : 
 
 " In recommending the ' Ladies' Lexicon,' therefore, to all our readers, 
 male and female, who have ever experienced the difficulties which it is so 
 admirably calculated to remedy, we but do an ordinary act of justice to the 
 author and publisher. We consider the 'Ladies' Lexicon,' and recom- 
 mend it to our readers, as a work that possesses superior claims on their 
 attention and patronage." 
 
 In giving the above extracts, we take occasion to say, that teachers will 
 find the "Ladies' and Gentlemen's Lexicons" works admirably adapted to 
 take the place, with advantage to their pupils, of the different works re- 
 cently put into their hands under the name of Expositors, &c. 
 
 dj^The above work has been introduced as a Class Book into many of 
 our Academies and Schools with great approbation. 
 
 BIGLAND'S NATURAL HISTORY of Animals, Birds, 
 Fishes, Reptiles and Insects, illustrated with numerous and beautiful en- 
 gravings. By John Bigland, author of a "View of the World," "Letters 
 on Universal History," &c. Complete in 1 vol. 12mo. 
 
 dj" This work is particularly adapted for the use of Schools and Fami- 
 lies, forming the most elegantly written and complete work on the subject 
 of Natural History ever published, and is worthy of the special attention 
 of the Teachers of all our Schools and Academies. 
 
 BIGLAND'S NATURAL HISTORY OF ANIMALS, illus- 
 trated with 12 beautifully coloured engravings. 
 
 BIGLAND'S HISTORY OF BIRDS, illustrated with 12 
 beautifully coloured engravings. 
 
 PERSIA. A DESCRIPTION OF. By Shoberl, with 12 
 coloure'd plates. 
 
 These works are got up in a very superior style, and well deserve an 
 introduction to the shelves of every family library, as they are very inte- 
 resting, and particularly adapted to the juvenile class of readers. 
 
6 GRIGG & ELLIOT'S SCHOOL BOOKS. 
 
 CONVERSATIONS ON ITALY, in English and French, 
 designed for the use of Schools, Academies, &c. By Miss Julia S. Hawkes* 
 in 1 vol. 12mo. 
 
 (/ This work is spoken very highly of by Miss C. Beecher, (who form- 
 erly taught in Hartford, Conn., and who has done as much for the elevation 
 of the female character, and for education generally, as any other lady in 
 this country,) and has received the highest recommendation from our most 
 distinguished Teachers, and the American press. 
 
 MURRAY'S EXERCISES, adapted to his Grammar. Grigg 
 and Elliot's stereotype edition. 
 
 MURRAY'S KEY TO THE EXERCISES. Grigg and 
 Elliot's stereotype edition. 
 
 HORACE DELPHINI. Grigg and Elliot's new corrected 
 stereotype edition. 
 
 The Delphin Classics (of which Horace Delphini and Virgil Delphini 
 are two,) were prepared at the express command of the King-of France, 
 for the education of his son, the Dauphin. They are not the result of the 
 labours of a single man, but of many of the most learned men of whom 
 France could boast; and consequently they ought, by every thinking mind, 
 to be considered as near perfection as it is possible to approach. They 
 are illustrated in the margin by an ordo, and at the foot of each page by 
 most copious and learned notes in the Latin language ; and they are sub- 
 mitted to the judgment of every teacher. 
 
 VIRGIL DELPHINI. Grigg and Elliot's new corrected 
 stereotype edition. 
 
 For remarks respecting this work and the Delphin Classics generally, 
 see note to " Horace Delphini," immediately above. 
 
 HUTCHINSON'S XENOPHON, with notes, and a Latin 
 translation under the Greek in each page, by Thomas Hutchinson, A. M. 
 
 This edition of the above valuable work is printed on a large and bold 
 Greek type ; and has, in order to insure its accuracy, been stereotyped. 
 The classical elegance and well-known celebrity of Xenophon demand of 
 every teacher, that he should place it unmutilated and complete in the 
 hands of his scholars, instead of being content with the meagre extracts 
 which are made from it in many of the Greek compilations for schools of 
 the day. 
 
 r/2&.^ 
 
;W VALUABLE WORKS 
 
 FOR 
 
 PUBLIC AND PRIVATE LIBRARIES, 
 PUBLISHED BY GRIGS & ELLIOT, 
 
 And for Sale by Booksellers and Country Merchants 
 generally throughout the United States. 
 
 SPLENDID LIBRARY EDITIONS, &c. 
 
 Crabbe, Heber and Pollok's Poetical Works, steel portraits, complete in 1 
 
 vol. 8vo., bound, library style. 
 
 The same work, calf extra, embossed gilt, and calf extra gilt. 
 Byron's Works, complete in 1 vol. 8vo., including all his suppressed and 
 
 attributed poems, bound, lib. style. 
 
 The same work, calf extra, embossed gilt, and calf extra gilt 
 Cowper and Thomson's Prose and Poetical Works, complete in 1 vol. 8vo., 
 
 bound, library style. 
 
 The same work, calf extra, embossed gilt, and calf extra gilt. 
 Rogers, Campbell, Montgomery, Lamb and Kirk White's Poetical Works, 
 
 complete in 1 vol. 8vo., bound, library style. 
 The same work, calf extra, embossed gilt, and calf extra gilt. 
 Milton, Young, Gray, Beattie and Collins' Poetical Works, complete in 1 
 
 vol. 8vo., bound, library style. 
 
 The same work, calf extra, embossed gilt, and calf extra gilt. 
 Mrs. Hemans' Poetical Works, complete in 1 vol. 8vo., bound, lib. style. 
 The same work, calf extra, embossed gilt, and calf extra gilt. 
 
 tfj* This is a new and complete edition, with a splendid engraved like- 
 ness of Mrs. Hemans, on steel, and contains all the Poems in the last Lon- 
 don and American editions. 
 McMahon's American Gardener, 9th editipn, greatly improved, 8vo., fine 
 
 edition. v? r 
 Goldsmith's Animated Nature, beautifully illustrated, 2 vols. 8vo., about 
 
 300 cuts. 
 Laurence Sterne's Works, with a Life of the Author, written by himself, 
 
 8vo., engraved portrait. 
 
 Burder's Village Sermons. For Family Reading. 
 Josephus' Works, 2 vols. 8vo., sheep, gilt. 
 
 (/ The only readable edition published in this country. 
 Say's Political Economy, 8vo., new edition. 
 Mason's Popular System of Farriery, new edition. 
 
 7 
 
8 GRIGG & ELLIOT'S MISCELLANEOUS BOOKS. 
 
 Hind's Popular System of Farriery, new edition. 
 
 The Stock Raiser's Manual, by W. Youatt, with plates. 
 
 The Importance of Family Religion, by Rev. S. G. Winchester, 1 vol. 12mo. 
 
 Seneca's Morals. " Should be found in every library." 
 
 Shoberl's History of Persia, with 12 fine coloured plates, fancy paper. 
 
 Bigland's Natural History of Animals, 12 fine coloured plates, fancy paper. 
 
 Bigland's Natural History of Birds, Fishes, &c., 12 coloured plates, fancy 
 
 paper. 
 
 Dictionary of Select and Popular Quotations, 9th edition. 
 The American Chesterfield, containing a complete Treatise on Carving, 
 
 with cuts. 
 
 The Southern and Western Songster, plate. 
 The Daughter's Own Book. 
 Bennett's Letters to Young Ladies. 
 
 The Gentlemen and Ladies' Book of Politeness, and Propriety of Deport- 
 ment, by Mrs. Celnart. 
 The Life of General Jackson. 
 Winchester's Family Prayers, fine edition. 
 
 The New Testament, royal 8vo., large type, new edition, for Family use. 
 Letters from a Father to his Sons in College, by Samuel Miller, D. D. 
 Bigland'.s Natural History, with 24 coloured plates, half mor. ext. gilt ed., 
 
 and plain School edition. 
 Shakspeare's Plays, various editions. 
 Weems' Life of Marion. 
 
 Do. do. Washington. 
 Polyglott Bible, 18mo., plain sheep, rolled ed. 
 
 Do. do. morocco tucks, gt. ed. 
 
 Do. do. plain Eng. calf, gilt ed. 
 
 Do. do. Eng. calf, super ex. do. 
 
 Do. do. Turkey, mor. gilt ed. 
 
 Pearl Pocket Bible, best ed. published, plain sheep. 
 
 Do. do. do. mor. tucks, gt. ed. 
 
 Do. do. do. plain Eng. calf, gt. ed. 
 
 Do. do. do. calf, sup. extra gt. 
 
 Do. do. do. Tur. mor., extra gt. ed. 
 
 (/ All the above Bibles are in the best Philadelphia binding. 
 
 IC7 3 Public, private, and social libraries, and all who purchase 
 to sell again, supplied on the most reasonable terms with every 
 article in the Book and Stationery line ; including new novels, 
 and all new works in evervdgpartment of literature and science. 
 
 All orders will be tn^y^r^delvend promptly attended to. 
 
 UNIVERSITY 
 
 OF 
 
THIS BOOK IS DUE ON THE LAST DATE 
 
 RETURN TO the circulation desk oTany 
 University of California Library 
 or to the 
 
 LIBRARY 
 , Richmond Field Station 
 
 University of California 
 Richmond, CA 94804-4698 
 
 2 
 
 MAY BE RECAL LED AFTER 7 DAYS 
 
 may be 
 
 . 
 
 DUE AS STAMPED BELOW 
 
 __ 
 
 04 1994 
 
 
YB 27350 
 
 U.C.BERKELEY LIBRARIES 
 
RUSOHENBEHGEH'S 
 
 FIRST BOOKS 
 
 OP 
 
 INATUKAL HISTORY,! 
 
 FOR SCHOOLS, COLLEGES, AND FAMIUi-s. 
 
 1. ELEMENTS OF 
 
 ANATOMY AND PHYSIOLOGY. 
 
 2. ELEMENTS OF 
 
 MAMMALOGY, 
 
 The Natural History of Quadrupeds, 
 
 8.. ELEMENTS 
 
 ORNITHOLOGY, 
 
 The Natural History of Birds. 
 
 4. ELEMENTS ? 
 
 HERPETOLOGY AND ICHTHYOLOGY I] 
 
 The Natural History of Reptiles and Fishes 
 
 5. ELEMENTS OF 
 
 CONCHOLOGY, 
 
 The Natural History of Shells and Mol!uca. 
 
 6. ELEMENT? ' 
 
 EN TO MO LOGY, 
 
 The Natural History of Insects, 
 
 7. ELEMENTS OF 
 
 BOTAIY, 
 
 The Natural History of Plants. 
 
 8. ELEMENTS OF 
 
 GEOLOGY, 
 
 The Natural History of the Earth's SUtictnrc. 
 
 rs have been issued, and have already met with the most flatter- !; 
 Jig reception ever extended to any work issued from the American press, j 
 Introduced into the Public Schools of Pennsylvania, and in nearly all the 
 fi'^t class seminaries of learning in the United States. 
 
 '