UC-NRLF 
 
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LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA 
 
 GIFT OF 
 
 ^Accession 
 
THE 
 
 MOSAICAL AND MINERAL 
 GEOLOGIES, 
 
THE 
 
 MOSAICAL AND MINERAL 
 GEOLOGIES, 
 
 ILLUSTRATED AND COMPARED. 
 
 BY 
 
 W. M. HIGGINS, F.G.S., &c. 
 
 LONDON: 
 JOHN SCOBLE, 110, CHANCERY LANE. 
 
 1832. 
 
 . . 
 
 I 
 
ADLARD, PRINTERS, 
 BARTHOLOMEW CLOSE. 
 
THE 
 
 MOSAICAL AND MINERAL GEOLOGIES, 
 
 INTRODUCTORY REMARKS. 
 
 As the sciences have advanced towards perfection, they 
 have not only tended to illustrate the sacred record, but 
 have afforded new arguments in favor of its authenticity. 
 Yet there have always, in the infancy of science, been 
 found individuals who, after an imperfect examination 
 of nature, have formed such deductions as have led them 
 to deny the inspired character of the Bible ; while others, 
 professing to receive that book as of divine authority, 
 have doubted the propriety of comparing it with the 
 discoveries of philosophy. The one class has boldly 
 impugned its claims as a revelation from God; the 
 other has virtually denied the truth of its statements, 
 
 ..84729 
 
'2 INTRODUCTION. 
 
 by rejecting its philosophy, and withdrawing it from 
 investigation. 
 
 It is a matter of importance to those who are con- 
 vinced of the authenticity of the Bible, that its philo- 
 sophy should be properly understood, investigated in 
 its details, and compared with nature: and should the 
 examination conducted by them be at first unsatis- 
 factory, and the harmony of God's word and works 
 unapparent, the combination of irresistible arguments, 
 which had convinced them of the truth of revelation, 
 will lead them to conclude that there are imperfections 
 in their knowledge, or error in their deductions. 
 
 The man who has been unconvinced of the divine 
 character of the Bible, by the arguments which are so 
 powerful to Christians, will compare Geology and the 
 Mosaical History of the Creation with different feelings. 
 Should he be unable to reconcile the statements of the 
 two, he will not hesitate to prefer his own deductions to 
 the clearest assertions of the Scriptures, and perhaps 
 adduce it as a fresh argument against its authenticity. ' 
 
 It would be well for such a mind to remember, that 
 Geology is as yet only in its cradle, and its nurses have 
 scarcely recognised the features of its countenance. 
 Many of those facts which are now received as prin- 
 ciples, may hereafter be found to be exceptions, and 
 
INTRODUCTION. .3 
 
 thus overturn all those deductions which are built upon 
 them: and as so many theories, proposed by men of 
 acknowledged genius, have been disproved by the 
 accumulation of knowledge, so it is possible that those 
 upon which he is placing so much reliance, may here- 
 after share the fate of their predecessors. 
 
 But there are some persons, who, though they admit 
 the inspired character of the Bible, doubt the propriety 
 of attempting to draw a parallel between the scriptural 
 representations of the creation, and the discoveries of 
 Geologists, supposing that it is unreasonable to expect 
 physical truths in a record intended for moral and 
 spiritual purposes. We are not a little surprised to 
 find Professor Sedgwick, a gentleman of great argumen- 
 tative talent, and a most successful Geologist, maintain- 
 ing these opinions. "Laws for the government of in- 
 tellectual beings," says the Professor, "and laws by 
 which material things are held together, have not one 
 common element to connect them: and to seek for an 
 exposition of the phenomena of the natural world among 
 the moral destinies of mankind, would be as unwise as 
 to look for rules of moral government among the laws of 
 chemical combination." ( GeoL Society's Proceedings, 
 p. 207.) 
 
 The question i* not whether we ought to expert a 
 
4 INTRODUCTION. 
 
 statement of physical truths in a work intended to 
 promote the spiritual welfare of mankind, but whether 
 those statements relative to the creation of the world, 
 which are given in the Bible, do coincide with those 
 facts which are discovered by an examination of the 
 constitution of the globe itself. Those who believe the 
 scriptures to be a divine revelation, cannot suppose that 
 the inspired historian was permitted to teach falsehood 
 when he sketched the outlines of the history of creation. 
 Yet the statement is either true or false ; and, if it does 
 not accord with the facts of Geology, it is the duty of 
 every honest mind to examine into the cause of the con- 
 tradiction, and to determine for itself whether Genesis 
 or Geology be more worthy belief. 
 
 In this view of the subject we are supported by the 
 authority of Mr. Watson, the able author of "Theolo- 
 gical Institutes." "It has been replied," says this 
 divine, "that the Bible not being intended to teach 
 philosophy, it is not fair to try it by a philosophical 
 standard; this, however, cannot be maintained in the 
 case before us, though the observation may be pertinent 
 in others. If Moses professes, by divine inspiration, to 
 give an account of the manner in which the world was 
 formed, he must describe the facts as they occurred." 
 (Theol. List., vol. i. p. 273.) 
 
INTRODUCTION. 5 
 
 To deny the propriety of examining the Mosaical v 
 History, for the purpose of comparing it with science, is 
 to insinuate its falsehood. Those Geologists who have 
 formed or adopted theories of the earth, have done so 
 from a belief of their truth : and professing themselves 
 the friends of revelation, they could not hesitate to 
 compare them with this standard of their faith, did they 
 not believe them inconsistent with its statements. But 
 the question must be fairly met and argued. Thinking 
 men are not so easily satisfied as to receive opinion for 
 argument, assertion for proof; and should their doubts 
 reach those who have not the disposition to investigate 
 for themselves, they cannot fail to have an injurious 
 effect upon their minds. 
 
 But this is not the extent of the evil. Admit that 
 one portion of the Mosaical writings is uninspired, and 
 a doubt of the authenticity of the remainder is also 
 insinuated. Happily, however, the whole system of 
 revealed truth stands on too sure a foundation to be 
 shaken. The Bible, as a literary composition, as a 
 system of morality and theology, and as a revelation 
 from the universal Creator, demands the first and closest 
 consideration of man: on every subject to which it refers 
 it is infallible, and to its decision human reason must 
 submissively bow. 
 
INTRODUCTION. 
 
 With these sentiments we commenced a comparison 
 of the Mosaical History of Creation and the principles 
 of Geology. If we had been unable to trace the harmony 
 of the two, we could not on that ground have doubted 
 the Mosaical description, for it is substantiated by more 
 numerous and powerful arguments than can be adduced 
 in favor of Geological opinions. We could only, under 
 such circumstances, have waited for a further develop- 
 ment of Geological facts. Should the comparison we 
 have drawn in the following pages fail to convince the 
 sceptical reader, it is hoped that he will see the pro- 
 priety of the same course ; and the author is certain that 
 the Christian who may differ from him in the interpre- 
 tation of the Sacred History, will treat his opinions 
 with the same candour which he himself expects from 
 others. 
 
: < : '4*>, 
 
 THE A 
 
 V Y ' 
 
 OUTLINE OF PRACTICAL GEOLOGY. 
 
 THE economical importance of Geology may be said 
 to consist in the knowledge it affords us of the reposi- 
 tories of the metallic ores and coal. Before the re- 
 searches of Geologists had determined the regular suc- 
 cession of rocks, the discovery of these must have 
 depended either on a fortunate trace of their presence, 
 or their actual appearance at the surface. But we are 
 not now left to such miserable chances ; their associated 
 rocks are known, their situations determined, and to 
 their favorable position and abundance in our island 
 we are greatly indebted for that high commercial 
 station we hold in the scale of nations. 
 
 But the proper object of Geology is to discover the 
 circumstances under which the beds composing the 
 crust of our globe, were formed. With this view we 
 examine the mineralogical characters of rocks, and 
 compare them with those that are still formed by rivers 
 and seas, or by volcanos and mineral springs; and 
 while we gain much information concerning the causes 
 
8 OUT LINK OF 
 
 by which a bed was formed, from the mere examination 
 of the structure, we are able, by the study of the 
 organic remains it contains, to form some adequate 
 notion of the circumstances under which they lived, 
 and consequently the condition under which the bed 
 itself was formed. 
 
 The most careless observer of nature must know 
 that the earth is not a solid mass of an individual 
 substance. It is hardly possible to pass over the most 
 limited district, and not discover this fact; sand and 
 sandstone, clay and limestone, are universally found in 
 all parts of the world. 
 
 From a partial examination of these various deposits, 
 we might be led to suppose that they were indis- 
 criminately situated in relation to each other. This 
 opinion is still held by nearly all those persons who 
 have not paid some attention to Geology. The interior 
 of that world which exhibits such wonderful order and 
 skilful arrangement on the surface, is in their imagina- 
 tion a very sample of confusion. So natural is tKis 
 supposition, that it is probable we might still have 
 indulged the error, had not the investigations of miners 
 insensibly led them to trace the super-position of rocks. 
 It was early discovered by these practical Geologists, 
 that certain ores were always found in certain rocks, 
 
PRACTICAL GEOLOGY. 9 
 
 and that certain other rocks accompanied those in 
 which the ores appeared. In their search for ores, 
 therefore, they endeavoured to assure themselves of the 
 presence of some of these beds, before they expended 
 either capital or labour in closer examination. The 
 more scientific observations which have since been 
 made, have extended the facts which they observed in 
 particular instances to the whole system of mineral 
 masses; and there is now no principle better substan- 
 tiated than the regular superposition of rocks. 
 
 But it is quite possible to take this statement in too 
 general a manner. It must not be supposed that our 
 earth is composed of a series of concentric beds, like 
 the coats of an onion, so equably spread over each other 
 that it is only necessary to pass through them in one 
 place to know the constitution of the whole globe. 
 
 The crust of the earth, and it is only the crust that 
 is open to investigation, is composed of so many beds, 
 that Geologists have been compelled to class them in 
 orders, formations, and sub-formations. A series of 
 beds which appear to have been formed by nearly the 
 same cause, and operated upon subsequently by the 
 same agents, are united by Geologists, and called a 
 sub-formation. Several of these sub-formations, when 
 united together, make a formation, and a union of 
 
10 OUTLINE OF 
 
 formations an order. Now a sub-formation may in 
 one place contain more beds than in another, or it may 
 be different in mineralogical characters. 
 
 We may illustrate this subject by reference to a 
 locality. Let us suppose that four series of rocks, 
 called the chalk, upper green sand, gault, and lower 
 green sand formations, are found resting upuii each 
 other. 
 
 The upper portion (chalk) of this series presents 
 the same characters in nearly all parts of the world. 
 But although this may be considered as the most 
 uniform of all the formations, yet there are certain local 
 variations in its mineralogical characters. It is gene- 
 rally soft, and of a white colour; but between Havre 
 and Rouen it is so indurated, as to take the appearance 
 of a compact limestone; and it is well known that in 
 some parts of the north of England, it has a red colour. 
 
 Beneath the chalk we come upon a series of beds 
 called the upper green sand. The beds of this forma- 
 tion are very different in certain localities, yet it is gene- 
 rally observed that the upper beds are cretaceous, and 
 that the lower have a sandy character. 
 
 Gault, which comes next in position, chiefly consists 
 of a blueish gray clay and marl ; but this formation also 
 varies in different places. 
 
PRACTICAL GEOLOGY. 11 
 
 The lowest formation of this series is that called the 
 lower green sand. This consists of sands and sand- 
 stones, of various colours and degrees of induration : 
 but its prevailing colour is green, 
 
 A rock which is usually found in a certain position, 
 may in particular localities be entirely wanting, or be 
 found in so different a character as to be scarcely 
 recognized. In one situation we may observe a series 
 of rocks to consist of a great variety of beds, very 
 different in their mineralogical appearance; but, in 
 another place, the same situation in the general suc- 
 cession of rocks may be occupied by but few beds, and 
 these greatly resembling each other in appearance and 
 constitution. 
 
 Rocks may be divided into two natural classes, the 
 stratified and unstratified ; the greater part are stratified, 
 and at an angle more or less inclined to the horizon. 
 On this account the edges of the beds emerge in suc- 
 cession from beneath each other, and make their appear- 
 ance at the surface of the earth. 
 
 Had rocks occurred in a perfectly horizontal position, 
 the same rock would have spread over a considerable, 
 tract of country ; and it would then have been difficult 
 to have obtained many of those minerals which are now 
 found at the surface of the earth. But in the arrange- 
 
12 OUTLINE OF 
 
 ment that has been adopted, we cannot but acknowledge 
 the superintending wisdom and power of God, ordaining 
 those causes which should produce a world best fitted 
 to promote the happiness, and support the social 
 character, of his future creature, man. 
 
 The mineral masses are for the most part stratified, 
 and the stratification is generally more or less inclined 
 to the plane of the horizon; but this is not the universal 
 position of stratified beds. Not unfrequently they take 
 a basin shape, as may be seen in many of the coal 
 districts, and in the secondary rocks. Paris and London 
 stand on these basin-shaped beds, and the same strati- 
 fication is beautifully developed in the Isle of Wight. 
 Rocks also present what is called, from its branching- 
 appearance, a fan-shaped stratification, and at other 
 times a saddle shape, which is the reverse of the 
 former, or may be compared to the section of a roof. 
 These three kinds of stratification are so variously 
 modified, that it requires some extent of observation, 
 before the great violence and varied action of those 
 subterranean forces which have been chiefly instru- 
 mental in giving them their forms, can be fully esti- 
 mated. 
 
 The natural position of the unstratified rocks is below 
 all others, but they sometimes intrude themselves among 
 
PRACTICAL GEOLOGY. 13 
 
 those which, in an undisturbed position, lie above them. 
 We therefore find them in nearly all parts of the series, 
 sometimes intersecting rocks in the form of veins, and 
 at other times super-posing them, as though they had 
 flown over them in a manner similar to the lavas of the 
 present day. And not unfrequently they have been 
 instrumental in forming mountains of very considerable 
 elevation, from the influence they have exerted upon 
 rocks, tilting the horizontal strata in some instances, 
 and in others so disrupting them as to expose them to 
 the influence of denuding waters. 
 
 The unstratified rocks, therefore, cannot be said to 
 occupy any determinate situation in the geological series. 
 Sometimes they are found in connexion with the non- 
 fossil iferous group, which is the lowest series of rocks ; 
 and at other times, with the mammiferous group, which 
 is the highest, and with all the intermediate series. In- 
 stances of this may be easily adduced : at Klostergrab, 
 in Bohemia, some rocks of the granitic group are asso- 
 ciated with the non-fossiliferous, stratified; in Norway, 
 with the lowest fossiliferous j in Saxony, with the grau- 
 wacke ; in Germany, with the red sandstone group ; and 
 at Angers, with the mammiferous. 
 
 Another classification which rocks admit, is into 
 Fossiliferous and Non-fossiliferous. The lower beds of 
 
14 OUTLINE OF 
 
 that portion of the earth's crust with which we are 
 acquainted are destitute of all remains of organized 
 beings, and are usually called the Primitive or Primary 
 Rocks, as they are supposed to have been formed before 
 the creation of things that have life. The unstratified 
 rocks are also destitute of fossils, as we might expect, 
 for they are almost unanimously attributed to the action 
 of fire. But, excepting the few stratified beds called 
 Primitive, and the unstratified, nearly all others con- 
 tain organic remains, some of which are of a most 
 remarkable character, and now extinct. 
 
 It has also been discovered that every fossiliferous 
 formation contains certain organic remains peculiar to 
 itself, wherever it may be found. It has already been 
 stated that the same formation varies considerably in 
 its mineralogical characters, and geologists have con- 
 sequently been compelled to identify beds by their 
 fossils. London and its vicinity stands on a clay which 
 is called the London or blue clay. In the neighbour- 
 hood of Paris, a coarse sandstone, the calcaire gros- 
 siere, occupies the same position in the series as the 
 blue clay in London. The mineralogical characters, 
 in this instance, are of little value in determining the 
 .identity of the strata. The value of fossils, therefore, 
 is immense; it enables us at once to decide upon the 
 
PRACTICAL GEOLOGY. 15 
 
 relative position of a bed, whatever may be its local 
 situation ; and to recognise it as well from a few of its 
 organic remains, as though we had examined the 
 country in which it occurs. It has, therefore, become 
 an object of great importance to Geology that the 
 fossils of every bed should be collected. Naturalists 
 have been induced to extend their investigations into 
 the bowels of the earth, a new world has been opened 
 to inquiry; a race of beings, before entirely unknown, 
 have been discovered, and a datum established by which 
 every geological problem may be solved. 
 
 The wonder of thinking men has ever been excited 
 by the discovery of the remains of organized bodies in 
 the solid strata of the globe. That these have been 
 objects of curiosity and investigation from the earliest 
 ages of civilization is not to be doubted; at any rate, 
 speculations on their nature, and the causes which 
 produced them, were indulged long before the science 
 of geology possessed a name. Some of these have 
 reached us, and appear remarkably ridiculous, and 
 little to be preferred to the notions of the most igno- 
 rant peasant of our own day; but since it has been dis- 
 covered that every bed has its particular fossils, oryc- 
 tology has risen into great estimation. This interesting 
 truth was first observed by Lister, upwards of one hun- 
 
16 OUTLINE OF 
 
 dred and fifty years ago; but the honour of demon- 
 strating it by extensive observations is due to Mr. 
 Smith. 
 
 The first classification of rocks was formed upon the 
 presence or absence of organic remains ; for the lower 
 rocks being destitute of them, were supposed to have 
 existed before the creation of things which had life, 
 and were hence called the Primitive or Primary Class, 
 and those which possessed them, the Secondary. But 
 as the science advanced, the importance of an inter- 
 mediary class, to comprise those beds which are formed 
 of conglutinated fragments of primary rocks, appeared 
 evident, and was adopted, under the name of the Tran- 
 sition, or Fragmentary class. Another division, called 
 the Tertiary, or Upper Secondary, has been since added ; 
 so that, according to this system, the substances which 
 form the crust of our globe, may be arranged in four 
 classes : 
 
 1. The Primary, or Crystalline. 
 
 2. The Transition, or Fragmentary. 
 
 3. The Secondary, or Sedimentary. 
 
 4. The Tertiary, or Upper Secondary. 
 
 It was long a disputed point with Geologists, whether 
 rocks should be arranged according to a mineralogical 
 
, 
 
 PRACTICAL GEOLOGY. 17 
 
 or geological classification ; those who maintained the 
 propriety of a mineralogical arrangement, urged its 
 advantages as a natural system, because it separates 
 between simple and compound rocks, avoids the repetition 
 which is necessarily connected with any other method, 
 introduces a perfect nomenclature, and involves no 
 hypothetical opinions. But with all these pretended 
 ad vantages, what would geology be with such an arrange- 
 ment, but a mass of uninteresting, not to say unintel- 
 ligible, facts? It disjoins that which nature has united, 
 it affords no clue to the relative ages of rocks, involves, 
 it is true, no hypotheses, but at the same time banishes 
 all our facts: in truth, it at once saps the foundation of 
 that beautiful fabric of knowledge, in the construction 
 of which the geologist has been so laboriously employed. 
 No system can be of any value to the student that 
 is not formed on geological principles. It is admitted 
 that a perfect arrangement upon this plan cannot as 
 yet be attained, for geologists have not yet sufficient 
 knowledge to enable them to accomplish their desire. 
 But as far as we are interested in the pursuit of this 
 desirable object, we are convinced that it is only by 
 maintaining in our classification that arrangement ob- 
 served in nature, that real knowledge can be imparted 
 to others. But, notwithstanding the disadvantages 
 
18 OUTLINE OF 
 
 connected with the classification of rocks, our know- 
 ledge has so increased, as to enable us to improve that 
 arrangement which was formerly adopted ; yet such is our 
 natural prejudice for those things to which we have been 
 accustomed, that geologists have not sufficiently availed 
 themselves of their increased information. 
 
 The Wernerian classification, which we have illus- 
 trated in the preceding table and remarks, was uni- 
 versally used in this country till the publication of 
 " Connybeare's Geology of England and Wales." In 
 this work a new classification was adopted, and the 
 crust of the earth divided into five portions, forming the 
 following classes : 
 
 1. The Superior, containing the tertiary deposits. 
 
 2. The Supermedial, containing the chalk, green 
 sand, weal den, oolitic, and red sandstone formations. 
 
 3. The Medial, containing the coal-measures, carbo- 
 niferous limestone, millstone grit, and old red sand- 
 stone formations. 
 
 4. The Submedial, comprising the transition rocks. 
 
 5. The Inferior, containing the primitives. 
 
 The most convenient and useful classification that has 
 been yet introduced, we think, is that proposed some 
 time since by Mr. De la Beche in the Annals of Phi- 
 
PRACTICAL GEOLOGY. 19 
 
 losophy, and since adopted with great success in his * 
 "Manual of Geology." But there are many objections 
 to new classifications, which prevent Geologists from 
 adopting those suggestions which they may consider 
 improvements. By using an established classification, 
 the scientific of all countries are able to correspond with 
 each other; but if a new arrangement be adopted, it 
 must necessarily be a considerable time before it can be 
 understood, and prejudice would prevent, in many in- 
 stances, its adoption. Such alterations can only be 
 effectually introduced by societies: for even old nomen- 
 clature will be preferred to modern improvements, as 
 we see in the alterations proposed by Mr. Conybeare; 
 for although his classes are far less objectionable than 
 the Wernerian, they have never been generally adopted. 
 It would, therefore, perhaps be desirable that the Geo- 
 logical Society should give some attention to the sub- 
 ject; but for the present use of the Geologist, we de- 
 cidedly recommend the classification proposed by Mr. 
 De la Beche. 
 
 All rocks may be divided into stratified and unstra- 
 tified; we have, therefore, in this fact, two leading divi- 
 sions not formed in the study, but from nature. Some 
 objection may be made to the arrangement, under a 
 supposition that it will impede our knowledge .of the 
 
 c2 
 
20 
 
 OUTLINE OF 
 
 superposition of rocks; but the separation of stratified 
 and unstratified beds is of no consequence, for the latter 
 are found in connexion with strata of all characters and 
 in all situations. The next general truth is, that the 
 lower stratified beds do not contain fossils, whereas 
 the others do; hence we have a subdivision into fos- 
 siliferous and non-fossiliferous. It then only remains 
 to arrange the strata into groups and formations, 
 and we at once obtain an easy and natural system of 
 rocks. The following pages will be arranged according 
 to this plan, of which the reader will obtain an accurate 
 notion by the following table: 
 
 STRATIFIED ROCKS. 
 
 Groups. 
 
 1. Alluvian. Peat bogs, sands, coral islands, 
 
 &c. 
 
 2. Diluvian. Transported boulders and blocks, 
 
 gravel, &c. 
 
 3. Supercretaceous. Upper and lower freshwater, and 
 
 marine formations. 
 
 4. Cretaceous. Chalk, green sand, and wealden 
 
 rocks. 
 
 5. Oolitic. Oolites and lias. 
 
PRACTICAL GEOLOGY. 
 
 21 
 
 Groups. 
 
 6. Red sandstone. Red marie and sandstone, mag- 
 
 nesian limestone, and red con- 
 glomerate. 
 
 7. Carboniferous. Coal measures, carboniferous 
 
 limestone, and old red sand- 
 stone. 
 
 8. Grauwacke. Grauwacke and grauwacke 
 
 slates. 
 
 9. Lowest fossilife- Argillaceous and other slates, 
 rous. 
 
 10. Non-fossiliferous Mica slate, gneiss, &c. 
 stratified. 
 
 Groups. 
 
 1. Volcanic. 
 
 2. Trappean. 
 
 3. Serpentine. 
 
 4. Granitic. 
 
 UNSTRATIFIED ROCKS. 
 
 Lavas, &c. 
 
 Greenstone, basalt, porphyry, 
 
 amygdaloid, &c. 
 Diallage rock and serpentine. 
 Syenite, granite, &c. 
 
 Having taken this general view of the elementary 
 principles of Geology and the classification of rocks, it 
 only remains for us to give some account of rocks them- 
 selves. The following Table of all the stratified beds 
 is arranged according to Mr. DC la Bcche's system. 
 
22 
 
 OUTLINE OF 
 
 Group. 
 
 formation 
 
 Sub-for- 
 ?nation. 
 
 General Charac- 
 ter. 
 
 Q ener aland cha- 
 acteristic Fossils 
 
 ALLUVIUM. 
 
 
 
 ravels, clay, and 
 sand, formed by 
 existing causes. 
 
 Hants, shells, and 
 animals, still ex- 
 isting. 
 
 DILUVIUM. 
 
 
 
 Gravels, clays, and 
 sands, immediately 
 superposing the 
 ancient beds. 
 
 ones of animals, 
 terrestrial and ma- 
 rine. Rhinoceras 
 trichorhinus. 
 
 SUPERCRE- 
 
 Upper fresh 
 water for- 
 mation. 
 
 
 leds variable, chief- 
 ly marls and mill- 
 stones. 
 
 Fresh water shells 
 and terrestrial 
 plants. 
 
 
 Upper ma- 
 rine. 
 
 
 Sandstones, sands, 
 and greenish marl. 
 
 Marine shells ; fresh 
 water, and terres- 
 trial shells, and 
 plants subordinate. 
 
 econd fresh 
 water for- 
 mation. 
 
 
 Marl, gypsum beds, 
 and limestones. 
 
 Terrestrial and fresh 
 water plants, shells, 
 birds, saurians and 
 carnivora. 
 
 Second ma- 
 rine forma- 
 tion. 
 
 xmdon 
 clay, or cal 
 caire gros- 
 sier. 
 
 n Paris, course 
 limestones and 
 marls. InEnglanc 
 blue clay. 
 
 Marine plants, 
 shells, and turtles; 
 terrestrial plants, 
 subordinate. Ceri- 
 thium gigantium. 
 
 Plastic clay. 
 
 Sands and clays. 
 
 ^ignite, terrestrial. 
 Fresh water, and 
 marine shells. 
 
 CRETACEOUS 
 
 Chalk for- 
 mation. 
 
 Upperchalk 
 Lower chalk 
 
 ?he upper portion i 
 generally soft, aiu 
 contains flint; th 
 lower is hard, anc 
 without flints. 
 
 Plants, Alcyonia, 
 shells and fish. Ma- 
 rine. Inoceramus 
 Cuvieri. 
 
 Upper gree 
 sand. 
 
 Sandstones and 
 marl. 
 
 Alcyonia, shells, and 
 fish. Ostrea cari- 
 nata. 
 
 jJreen sam 
 formation. 
 
 Gault. 
 
 Marly clay. 
 
 Plants, shark's teeth, 
 and testacea. Ino- 
 ceramus sulcatus. 
 
 Lower 
 
 Greensanc 
 
 Ferruginous and 
 green sands. 
 
 Plants, corals, shells, 
 fish, &c. 
 Trigonia aliformi*. 
 
PRACTICAL GEOLOCJY. 
 
 23 
 
 Group. 
 
 Formation 
 
 Sub-for- 
 mation. 
 
 General Charac- 
 ter. 
 
 General and cha- 
 racteristic Fossils 
 
 CRETACEOUS 
 
 (Continued ) 
 
 Wealden 
 formation. 
 
 Weald clay 
 
 Dark blue clay, and 
 clay ironstone. 
 
 Shells, fish, and cro- 
 codiles. Fresh wa- 
 ter. 
 
 Hastings 
 sands. 
 
 Sand and sand- 
 stones. 
 
 Plants, shells, fish, 
 reptiles, and birds. 
 
 Purbeck 
 beds. 
 
 Limestones and 
 marl. 
 
 Ostrea, fish, and cro- 
 codiles. Fresh 
 water and marine. 
 
 OOLITIC 
 
 Portland 
 Oolite. 
 
 
 Limestones. 
 
 Wood, corals, shells, 
 &fish. Marine. Am- 
 monites triplicata. 
 
 Kimme- 
 ridge clay. 
 
 
 Blueish clay and bi- 
 tuminous shale. 
 
 Testacea and rep- 
 tiles. Marine. 
 Ostrea deltoida. 
 
 Coral rag. 
 
 
 Sandstone, lime- 
 stones, and sands. 
 
 Wood, corals, and 
 shells. Marine. 
 
 Oxford clay. 
 
 
 Dark blue clay and 
 limestones. 
 
 Wood, testacea, and 
 reptiles. Gryphaea 
 dilata. 
 
 Cornbrash. 
 
 
 Rubbly limestone 
 and clay. 
 
 Testacea and rep- 
 tiles. 
 
 Forest mar- 
 ble. 
 
 
 Limestones and 
 sands. 
 
 Plants, testacea, 
 elytra of insects, 
 birds, and reptiles. 
 
 Bradford 
 clay. 
 
 
 Marly clay. 
 
 Corals and marine 
 shells. Apiocrinites 
 rotundus. 
 
 Great oolite. 
 
 
 Oolitic limestones. 
 
 Plants, corals, and 
 shells. Marine. 
 
 Fuller's 
 earth. 
 
 
 3 lay and Fuller's 
 earth. 
 
 Marine testacea. 
 
 fnferior 
 oolite. 
 
 
 limestones and 
 calcareous sands. 
 
 Marine shells and 
 Crustacea; some 
 terrestrial plants. 
 
 Lias. 
 
 
 3lue marl and lime- 
 stones. 
 
 3 lants, shells, fish, 
 & reptiles. Marine. 
 Gryphaea incurva. 
 
24 
 
 OUTLINE OF 
 
 Group. 
 
 formation 
 
 Sub- for- 
 mation. 
 
 General Charac- 
 ter. 
 
 General and cha- 
 acteristic Fossils 
 
 RED SAND- 
 STONE. 
 
 ed marl. 
 
 
 Variegated marls, 
 ontaining gypsum. 
 
 errestrial plants. 
 
 
 Vluschelkalk 
 
 
 Jmestones. 
 
 Vlarine plants and 
 testacea. 
 
 
 ew red 
 
 sandstone. 
 
 
 Micaceous sand- 
 stones. 
 
 terrestrial and 
 marine plants, and 
 a few testacea. 
 
 
 Vlagnesian 
 limestone. 
 
 
 Magnesian lime- 
 stones, and marl 
 containing gypsum 
 and rock-salt. 
 
 Vlarine fish and 
 testacea. 
 
 
 led con- 
 glomerate. 
 
 
 Sandstones and 
 conglomerates. 
 
 Vo fossils. 
 
 CARBONIFE- 
 ROUS. 
 
 Coal 
 measures. 
 
 
 A series of coal, 
 sandstone, and shale 
 beds, irregularly 
 alternating. 
 
 Terrestrial and fresh 
 water plants and 
 shells. 
 
 
 Vlillstone 
 grit and 
 shale. 
 
 
 Quartzose sand- 
 stones and shales. 
 
 Terrestrial plants. 
 
 
 Carbonife- 
 rous lime- 
 stone. 
 
 
 Blueish limestone. 
 
 Plants, encrinites, 
 corals, shells, ver- 
 tebrse and teeth of 
 fish. Marine. 
 
 
 Old red 
 sandstone. 
 
 
 Dark brown sili- 
 ceous sandstone. 
 
 terrestrial plants, 
 but rare. 
 
 CRAUWACK 
 
 jrauwacke. 
 
 
 Arenaceous and 
 slaty beds, contain- 
 ing limestones. 
 
 Vlarine plants, 
 shells, and' crus- 
 tacea. 
 
 LOWEST FOS 
 SILIFEROUS 
 
 Slate. 
 
 
 Clay and other 
 slates. 
 
 Shells. 
 
 NON-FOSSIL 
 IFEROUS 
 STRATIFIED 
 
 Chlorite, 
 Talcose, an 
 Hornblend 
 slates, Lim 
 stone, 
 Gneiss, 8cc 
 
 
 Schistose rocks anc 
 crystalline com- 
 pounds. 
 
 
PRACTICAL GEOLOGY. 25 
 
 This table will, we hope, convey, in as few words as 
 possible, the general superposition of the stratified 
 rocks, and their classification. It may not, however, 
 be altogether unacceptable to the general reader if we 
 indulge in a few remarks upon the several groups. To 
 enter at large upon a description of the formations, 
 would be to write a Treatise upon Geology. Our obser- 
 vations, therefore, must be brief and imperfect, being 
 only intended to give an outline of the principal phe- 
 nomena, and to draw the attention to some more 
 detailed statements. 
 
 THE ALLUVIAN GROUP consists of all those rocks 
 which are now forming; such as the depositions from 
 rivers and springs, lavas, coral reefs, and submarine 
 forests. 
 
 In various parts of this and other countries, large 
 accumulations of wood and plants, resembling in species 
 those which now exist, have been found. They all 
 appear to occur at a level beneath high-water mark, 
 and are generally upon the shores of the sea, or in 
 its estuaries. 
 
 We recently observed a submarine forest in the estuary 
 of Maldon, Essex, which consists of terrestrial plants. 
 In the deposit may be found the birch and the hazel, 
 
26 OUTLINE OF 
 
 the latter having its nuts quite perfect, though destitute 
 of kernels. There is another in the estuary of Salcombe, 
 Devon; but the wood is too decayed and compressed 
 to admit of distinguishing the trees of which it is 
 composed. 
 
 Peat is a substance certainly derived from decayed 
 vegetable mingled with earthy matter, and has taken its 
 present form from the chemical action of humidity 
 and pressure, producing a partial carbonization and 
 bituminization. It has been found, by the examina- 
 tion of the peat bogs of England and Ireland, that 
 they principally derive their origin from a species 
 of moss which grows in damp situations, and to 
 the casual inclusion of timber and smaller trees. In 
 many places the peat is found to be of considerable 
 thickness, and must have been the product of many 
 ages. The manner in which it is accumulated is well 
 known : the moss of one year's growth is covered by 
 that of the following, until a mass of considerable 
 thickness is accumulated. The air being excluded,, 
 and the pressure being increasingly great, the lower 
 portions, after partial decomposition, become solidified, 
 and in process of time parts with its organic structure, 
 becomes carbonised or bituminized, and in some in- 
 stances passes into a substance precisely similar in 
 
PRACTICAL GEOLOGY. 27 
 
 chemical composition to jet. Its general properties are 
 a brown or black colour, and bituminous character. It 
 is said to produce more ashes than any other combustible 
 substance, and contains sulphate of potash and alumina 
 in greater or less abundance. 
 
 There are several varieties of peat, and three are 
 recognised in commerce ; the light, the medium, and the 
 hard peat. These several sorts are occasioned by local 
 causes, such as the following : 
 
 1. The character of the vegetable substance com- 
 posing it. 
 
 2. The quantity of water infused into the bed, and 
 its state of decay. 
 
 3. The thickness of the deposit. 
 
 4. The weight of the other alluvian substances that 
 superpose it. 
 
 Peat beds are usually found in the bottom of ancient 
 lakes, or of those which are still covered by water. 
 They are also sometimes observed in high table lands, 
 and other places, but we believe that they never occur 
 except in humid situations. Peat beds frequently 
 contain the trunks and branches of trees, animal bodies, 
 coins, and workmen's tools, and are of more recent 
 formation than submarine forests. 
 
28 OUTLINE OF 
 
 Of the other alluvian deposits it is not necessary to 
 speak, as we shall have occasion to refer to them in 
 another place. 
 
 THE DILUVIAN GROUP includes the superficial 
 gravels, erratic blocks, and other deposits, attributable 
 to a great Diluvian action that occurred after the 
 deposition of the supercretaceous beds. 
 
 It is quite certain that pebbles can only be formed 
 by the action of water. If we examine the stones which 
 lie upon the shores of the sea, or the margin of lakes, 
 we universally find them smoothed by the action of 
 waves; and we can have no better proof of the former 
 existence of a water-course, than the presence of rolled 
 pebbles. Now, the whole earth is covered with this 
 proof of its having suffered under a universal deluge. 
 By the force of conflicting waters, rocks have been 
 broken and disintegrated; those which have been of 
 such a chemical composition as could resist water, have 
 been rolled by it, and those which could not resist the 
 solvent principle, have been united with the water and 
 afterwards deposited on the rolled pebbles, forming 
 those beds of gravel which now cover the surface of 
 our planet. 
 
 The fossils which are found in Diluvium are varied 
 
PRACTICAL GEOLOGY. 29 
 
 and numerous. As all rocks have suffered under the 
 effects of this deluge, so the fossils of all rocks may be 
 found; but in addition to these we find many bones 
 of the mammalia, which have not been discovered 
 elsewhere. Among others which have been recognized 
 in these deposits, we may mention those of the elephant, 
 mastodon, hippopotamus, rhinoceros, hyaena, bear, and 
 a very large elk. Several of the species of these 
 animals whose bones we find are now quite extinct. 
 
 At the same or nearly the same period that 
 these beds of gravel were formed, a great number of 
 caverns were excavated, and in these a vast accumula- 
 tion of bones have been found. For our intimate 
 acquaintance with these, we are chiefly indebted to the 
 investigations of Dr. Buckland, at Kirkdale. Kirkdale 
 is situated about twenty-five miles from York, between 
 Helmsley and Kirby Moorside. The position of the 
 cave is at the lower extremity of the dale of the Hodge 
 Beck. Its greatest length is about 245 feet, but there 
 are only two or three places where it is possible to stand 
 upright. The bottom of the cave, on first removing the 
 mud, was found to be strewed from one end to the 
 other with hundreds of teeth and bones, or rather 
 broken and splintered fragments of bones, belonging 
 to twenty-three different species of animals. Dr. 
 
30 OUTLINE OF 
 
 Buckland supposes this cave to have been, during a 
 long succession of years, inhabited by hyenas, and that 
 they dragged into its recesses the other animal bodies 
 whose remains are found mixed indiscriminately with 
 them. All the bones appear as though they had been 
 gnawed, and there are evidences of not less than two 
 or three hundred hyenas. 
 
 THE SUPERCRETACEOUS GROUP. Previous to the 
 investigations of MM. Cuvier and Brogniart, in the 
 neighbourhood of Paris, the beds which are com- 
 prized in this series were supposed to be mere super- 
 ficial gravels, clays, and sands, of the same age as the 
 Diluvian group. But by their labours and the inves- 
 tigations which have since been carried on in various 
 parts of the globe, it has been discovered that they have 
 a considerable geological importance. A great variety 
 of terrestrial, freshwater, and marine remains, some 
 belonging to genera now unknown, and others analo- 
 gous to recent specimens, have been discovered in the 
 various strata which compose the series. 
 
 About the same time that the French Geologists were 
 investigating the Supercretaceous group in the neigh- 
 bourhood of Paris, Mr. W. Smith, who will ever stand 
 high in the estimation of Geologists, was engaged in 
 
U / 
 
 PRACTICAL GEOLOGY. 31 
 
 tracing the superposition of English rocks; during 
 which investigation, he discovered the fact to which we 
 have already referred, that every series of beds contains 
 organic remains which are peculiar to itself, 
 
 To determine the succession of the Supercretaceous 
 rocks, we must necessarily depend upon this all impor- 
 tant principle, and arrange the beds by their fossils. 
 Either from the locality of the causes which produced 
 these rocks, or from the disturbances which they have 
 since suffered, we are not yet informed of any situation 
 in which all the deposits already known are collectively 
 found. In various parts of the globe we find small 
 individual collections of these beds, but it is a matter 
 of considerable difficulty to identify them with those 
 which are found in other situations. Our only resource, 
 therefore, in endeavouring to decide the relative ages, 
 or, in other words, the succession of many of the beds 
 belonging to the Supercretaceous group, is by their 
 fossils. 
 
 We cannot, however, but express a doubt which we 
 have long felt, relative to the age of several of the beds 
 which are classed in this group. May not many of the 
 isolated deposits which are now arranged in this series, 
 belong to the Diluvian period ? Nothing can be more 
 certain than that the world has suffered under an over- 
 
32 OUTLINE OF 
 
 whelming flood ; to its action we attribute that bed of 
 detritus which is found in every investigated country, 
 superposing formations of every age, indiscriminately as 
 they appear at the surface. But it does not seem pro- 
 bable that this should be the only effect of that revolu- 
 tion. In some places it must have been more violent 
 than in others, and its activity more continued ; and we 
 may reasonably expect that future investigations will 
 prove that many of the detached beds which are now 
 classed with this group, will be found to belong to the 
 Diluvian series. 
 
 M. Beaumont has discovered a most interesting, 
 and probably one of the most recent, deposits of the 
 Supercretaceous group in the valleys of the Isere, 
 and Rhone. It consists of a series of pebbles and 
 sand; and all the former may be traced to the Alps. 
 It is several hundred yards thick, and contains beds of 
 lignite, in which are found the freshwater shell called 
 Planorbes. M. Beaumont supposes it to have been 
 formed in the waters of a shallow lake, which existed 
 subsequent to the upheaving of the Alps of Savoy and 
 Dauphiny, but previous to the elevation of the main 
 chain from the Vallais, in Austria ; and that the peb- 
 bles and sand were transported by the action of torrents 
 from the Alps to the situation where they are now found. 
 
PRACTICAL GEOLOGY. 33 
 
 The Crag, which occurs so abundantly in Nor- 
 folk and Suffolk, is another of the Supercretaceous 
 rocks. This deposit varies considerably in its minera- 
 logical characters ; it is composed of a series of sand 
 and gravel beds, and other mechanical rocks, some of 
 them being remarkable for the marine productions they 
 contain. The beds of this formation have been ar- 
 ranged by our friend Mr. R. C. Taylor, in an unpub- 
 lished paper, into two natural divisions. The upper one 
 contains a numerous suite of sand and gravel beds 
 having a ferruginous character, and containing but few 
 organic remains. The lower division consists of strata 
 which have no other distinction than that of being- 
 crowded with very peculiar shells, zoophytes, and some 
 bones. 
 
 The nearest point to the metropolis at which the Crag 
 may be seen is not Walton Naze, as stated by Mr. 
 Phillips, but Danberry hills. The nearest place on the 
 Norwich road at which we have observed it is Black- 
 brook hill, near Stratford ; but this is the upper deposit, 
 and is without fossils, excepting a thin stratum of fer- 
 ruginous sandstone, which bears impressions of the 
 patella, cardium, and other shells. 
 
 "There are few localities of Crag," says Mr. Taylor, 
 " in which its shells have remained wholly uninjured by 
 
34 OUTLINE OF 
 
 the tumultuous action of the waves. So far as our 
 observation has extended, these shells seem to occur in 
 a more comminuted state at their greatest distance from 
 the present sea-shore : at Witnersham, Dedham, and a 
 few other extreme points, the organic remains are broken 
 into minute fragments; but nearer to the coast, and in 
 the cliffs, perfect specimens may be obtained in abun- 
 dance. With regard to the remains of terrestrial ani- 
 mals, they appear to have been drifted over the former 
 surface, blended with its materials, and most frequently 
 deposited along the margins of its estuaries. No in- 
 stance has yet been authenticated of the occurrence of 
 animal bones within the horizontal, undisturbed, and 
 purely marine beds, like those near Aldburgh and 
 Oxford; but they occur occasionally in the higher dis- 
 rupted and superficial deposits, particularly along the 
 river-banks and slopes of the valleys." One of the 
 most characteristic sections of the Crag with fossils is, 
 perhaps, at Tattingstow, in Suffolk, where it is con- 
 siderably exposed and the stratification well deve- 
 loped. 
 
 These are some of the deposits belonging to this series 
 which cannot at present be classified in any deter- 
 minate order. But, as our knowledge of the Super- 
 cretaceous deposit increases, we shall probably meet 
 
PRACTICAL GEOLOGY. 35 
 
 with some tests by which we shall be able to establish 
 their relative ages. Professor Sedgwick and Mr. 
 Murchison have, with great success, attempted to 
 determine the age of the tertiary deposits of Lower 
 Styria; and it is only by such rigid observation and 
 accurate comparisons as they have exercised, that we 
 can obtain the knowledge that is desired. 
 
 As the superposition and general characters of the 
 regular deposits of this group are detailed in the pre- 
 ceding table, we shall only make a few remarks in 
 illustration of the lower marine formation. 
 
 The London and Plastic clay formations were for- 
 merly supposed to be essentially different. But it is 
 now generally admitted that they are but members of 
 one series, and have no zoological separation. The 
 London clay is a thick argillaceous deposit, containing 
 a great number of marine fossils; the Plastic clay con- 
 sists of a series of clays, sands, sandstones, and pebble 
 beds, irregularly alternating. Of these, the sands are 
 most extensive in England. 
 
 One of the best developed sections of the Plastic clay 
 beds that we have seen is at Upnor, near Chatham, on 
 the banks of the Medway. The following is the sec- 
 tion referred to: 
 
36 OUTLINE OF 
 
 1. Blue London clay. 
 
 2. Brick earth, . . 15 feet. 
 
 3. Indurated marie, . . 18 inches. 
 
 4. Brown sand, . . . 18 inches. 
 
 5. Pebbles, shells, and sand, containing 
 
 cytherea, turritella, and a large gibbous 
 bivalve, but in a very decayed state, 3 feet. 
 
 6. Fine brick earth, containing two varieties 
 
 of ostrea. The jaw and vertebrae of a 
 horse, and part of the skull of an ani- 
 mal of the deer kind, have been found, 10 feet. 
 
 7. Clay and shells. This bed is almost 
 composed of shells. Cytherea, turri- 
 tella (three species), niga piana, ostrea 
 tener, and murex latus, have been dis- 
 covered, . . . 3 to 6 feet. 
 
 8. Ochreybed. Composed of clay strongly 
 coloured by oxide of iron, and contain- 
 ing crystals of selenite, . 2 to 4 feet. 
 
 9. Carbonaceous bed. An imperfect coal, 
 filled with selenite, and impregnated 
 with iron. When dry, it burns without 
 flame or smoke, with great heat, before 
 the blow-pipe, leaving reddish brown 
 
 hard ashes. 4 to 12 inches. 
 
PRACTICAL GEOLOGY. 37 
 
 10. A white and grey sand, , 2 feet. 
 
 11. Sand of a grey colour, till within three 
 feet of the top, where it assumes a yel- 
 low ferruginous hue. Two species of 
 
 ostrea are found. . -;;<; Depth unknown. 
 
 Till lately, there was some doubt whether fossil 
 bones were ever found in the Plastic clay; but the 
 above section would be sufficient to set this question 
 at rest. 
 
 The London clay is nowhere better developed than 
 in the Isle of Sheppey; and no deposit can contain a 
 richer variety of organic remains. Seven hundred 
 species of seed-vessels have been obtained from the 
 Minster cliffs ; and we have a greater number of fossil 
 fish from the same district than can be found in any 
 other English rock. The only remains of the higher 
 order of animals contained in the London clay belong 
 to the saurians and turtles. 
 
 THE CRETACEOUS GROUP consists of a series of 
 rocks known by the names of chalk, upper green sands, 
 gault, and the lower green sands. 
 
 The Chalk is the upper portion of this group, and 
 extensively developed in Europe, particularly in 
 
38 OUTLINE OF 
 
 England. It is a singular fact that the fossils of this 
 rock occur in patches. The chalk of Sussex is remark- 
 able for its abundance of molusca and fish; that of 
 Hampshire for its radiaria; and Kent for its polypi and 
 conchifera. The latter county is generally almost des- 
 titute of the remains of fish ; but after an unsuccessful 
 search, continued for several months, we found one 
 situation in which they occur in great abundance, and 
 from it have obtained some most beautiful and rare 
 specimens. 
 
 The Cretaceous group may, in general terms, be 
 described as cretaceous in its upper beds, arenaceous and 
 argillaceous in its lower ; but in the north of England, 
 the lower deposits are almost entirely wanting. 
 
 The remains of mammalia have never been discovered 
 in the Cretaceous group, but several reptiles have been 
 determined, one of which, the Mososaurus Hoffmanni, 
 was about the size of the crocodile, and appears to have 
 been an aquatic animal. 
 
 The bones and teeth of fish have also been dis- 
 covered, and some few of the Crustacea. The fossil 
 vegetables are chiefly marine : the shells are very nume- 
 rous; and some few genera have been discovered which 
 are peculiar to this series. 
 
PRACTICAL GEOLOGY. 39 
 
 THE WEALDEN GROUP is best developed in Sussex, 
 and is remarkable for the beauty and singularity of 
 its fossils. In the Hastings beds we meet with that 
 enormous herbivorous reptile the iguanodon, discovered 
 by Mr. Mantell, which surpassed all others in mag- 
 nitude. Its teeth are as large as the incisors of the 
 rhinoceros; and a thigh bone has been discovered which 
 measures twenty-three inches in circumference. It is 
 generally supposed that this animal was shorter, in pro- 
 portion to its bulk, than the recent lizards, to which it 
 is most allied; but, even with this allowance, it must 
 have been more than fifty feet in length, and eight or 
 nine in height. 
 
 THE OOLITIC GROUP consists of various beds of 
 clay, sandstones, marls, and limestones, many of the 
 latter being oolitic in their structure, that is, composed 
 of particles which are of a roe-like form. In the south 
 of England, this group is divided into three portions, 
 by large deposits of clay; and geologists have gene- 
 rally adopted the same arrangement, and divide the 
 oolitic group into three systems. 
 
 The highest portion of this group includes the Port- 
 land oolite and the Kimmeridge clay; in which the 
 
40 OUTLINE OF 
 
 bones of the ichthyosaurus, plesiosaurus, and other 
 extinct animals, have been found. 
 
 The ichthyosaurus was a most singular reptile; it had 
 the snout of a dolphin, the teeth of a crocodile, and 
 the vertebras of a fish : it had a large head, enormous 
 eyes, a short neck, and long tail; was furnished with 
 four broad and flat paddles, was evidently destined to 
 live in the sea, and attained a length of from twenty to 
 thirty feet. 
 
 The plesiosaurus bore some resemblance to the ich- 
 thyosaurus: it had four paddles, but differed from all 
 other animals in the remarkable length of its neck. 
 The neck of reptiles is composed of three to nine ver- 
 tebrae; but in a species of plesiosaurus there are up- 
 wards of thirty. It had the head of a lizard, and the 
 neck must have resembled the body of a serpent. This 
 reptile was not calculated to make such a rapid progress 
 through the waters as the ichthyosaurus, and probably 
 lived upon fishes and molusca. 
 
 The middle system of the oolitic group includes th'e 
 
 coral rag and the Oxford or clunch clay : the former 
 
 I 
 
 takes its name from its being a loose rubbly lime- 
 stone, containing a great quantity of madrepores. The 
 whole system is well developed at Headington, two 
 miles east of Oxford. 
 
PRACTICAL GEOLOGY. 41 
 
 The third system comprises the cornbrash, forest mar- 
 ble, Bradford clay, great oolite, fullers' earth, inferior 
 oolite, and lias. 
 
 The Stonesfield slate, which is a grey oolitic lime- 
 stone, and a part of the forest marble formation, is the 
 most singular bed of this group, and is remarkable for 
 its organic remains, which consist of the bones of birds 
 and amphibia, mingled with the remains of shells and 
 vegetables: the monitor, sauri, and the ichthyosaurus, 
 have been found ; also the elytra of coleopterous insects. 
 Specimens of the remains of the monitor have been 
 discovered, which must have belonged to an animal 
 forty feet long and twelve feet high; and it is in the 
 Stonefield slate that we first meet with the bones of 
 that gigantic creature the megalosaurus, which was pro- 
 bably a terrestrial animal, from thirty to forty feet in 
 length, and seven or more in height. 
 
 The lias, which is the lowest formation in the oolite 
 group, abounds in beautifully preserved fossils, among 
 which is the pterodactylus, a flying reptile, with the 
 wings of a bat and the body of a reptile. It had 
 sharp teeth and claws, with long hooked nails; its food 
 was, probably, insects; and we generally find them 
 imbedded in those deposits in which its remains are 
 found . 
 
42 OUTLINE OF 
 
 THE RED SANDSTONE GROUP may be divided into 
 five formations: the red or variegated marls, the mus- 
 chelkalk, the red or variegated sandstone, the mag- 
 nesian limestone, and the red conglomerase. 
 
 The red marl formation consists, as its name implies, 
 of a series of marly deposits, and contains a variety of 
 vegetable remains and sometimes the scales offish. It 
 may be seen between Lyme Regis and Sidmouth ; but 
 is better developed on the Continent than in our own 
 country. 
 
 The muschelkalk is a limestone usually of a grey 
 colour and compact texture. The term is derived from 
 two German words, muschel, a muscle; and kalk, lime. 
 This rock is unknown in England, but in Germany and 
 in the south and east of France, is well developed; it 
 contains the bones of the ichthyosaurus, plesiosaurus, 
 and saurians, with some shells. 
 
 The magnesian limestone formation derives its name 
 from the large proportion of magnesia in the crystalline 
 varieties: the presence of this mineral in rocks was 
 first discovered by Dolomieu, and on this account all 
 those limestones which contain it are called Dolomites. 
 
 THE CARBONIFEROUS GROUP may be divided into 
 three series, which are severally known by the terms, 
 
PRACTICAL GEOLOGY. 43 
 
 coal measures, carboniferous or mountain limestone, 
 and old red sandstone. 
 
 The series of beds denominated the coal measures, 
 is composed of various deposits of sandstone, shale, 
 and coal, irregularly alternating. In some situations 
 there are not less than thirty or forty beds of coal, 
 which are separated from each other by beds of sand- 
 stone or shale. 
 
 Shale is a slatey clay, and occupies nearly three- 
 fourths of the mass constituting the coal measures. 
 Sometimes beds of clayey ironstone are found in con- 
 nexion with the coal, and is called metal-stone by the 
 miners. Next to the coal, this is the most important 
 bed of the formation, as the greater part of the iron 
 which is used in this country is obtained from it. 
 
 The coal measures abound in most interesting vege- 
 table remains, and it is now pretty generally allowed 
 that coal itself had a vegetable origin. The whole of 
 the series has been greatly shattered and contorted, and 
 the progress of mining operations is often impeded from 
 this circumstance. These fractures, or faults, as they 
 are called by the miners, although very embarrassing 
 to those who are engaged in working this valuable 
 mineral, evince, we think, marks of deep design, which 
 every thoughtful mind must observe. That the 
 
44 OUTLINE OF 
 
 Creator of all things should, in so distant an epoch 
 of the history of the world, have provided for the comfort 
 of his future creatures, is in itself a circumstance of 
 grateful remembrance ; but when we view, in connexion 
 with it, the arrangement of causes which should so 
 dispose these strata as to bring them immediately before 
 our attention, at the surface of the earth, we cannot fail 
 to be convinced of a superintending design. 
 
 Beneath the coal measures we come upon the carbo- 
 niferous or mountain limestone, which is chiefly remark- 
 able for the quantity of lead ore it contains. Mr. 
 Taylor has stated that 25,000 tons are annually extracted 
 from it. 
 
 THE GRAUWACKE GROUP may be considered as a 
 mass of arenaceous and slatey rocks, containing lime- 
 stone: it is usually of greyish blue colour, but in the 
 south of Devon is sometimes red. It is extensively 
 distributed over the globe, and is uncommonly pro- 
 ductive of the metallic ores: the lead and silver mines 
 of the Hartz are situated in it. In the south of Scotland 
 it composes many of the mountain chains, and in Tran- 
 sylvania is traversed by veins of gold. 
 
 This group contains a considerable variety of fossils, 
 belonging to both existing and extinct genera: it also 
 
PRACTICAL GEOLOGY. 45 
 
 abounds with the remains of plants apparently belonging 
 chiefly to the Equiseta and Calamites. In Ireland they 
 are very abundant, and according to Mr. Weaver 25,000 
 tons are annually raised at the Dronagh collieries, (Pro- 
 ceedings of Geological Society, p. 232 ;) and Professor 
 Eaton states that they have been observed in the 
 United States, at Worcester and Newport. (American 
 Journal of Science, vol. 19.) 
 
 THE LOWEST FOSSILIFEROUS GROUP. "This 
 group," says Mr. de la Beche, "should be considered 
 as little more than one of convenience, in which rocks 
 containing a few organic remains are sometimes mixed 
 with strata of the same character as those enumerated 
 under the head of Non-fossiliferous Rocks." (Geological 
 Manual, p. 456.) 
 
 The principal rock of this series is the transition clay 
 slate : the varieties of this rock are as numerous as its 
 colours; but the almost endless change of appearances 
 which the same rock will present, is easily accounted 
 for, when we remember that the smallest alteration 
 in the quantity or character of the constituent parts of 
 any substance decidedly alters the appearance of the 
 mass. 
 
 The finer varieties of slate are usually found imbedded 
 
46 OUTLINE OF 
 
 in rocks of a coarser texture, and some quarries of it 
 are extensively worked in several counties. When carbo- 
 naceous matter is present, (and in the slate rocks it makes 
 its first appearance,) the slate is more smooth, and the 
 greater the proportion the more useful for the purpose 
 of drawing. 
 
 S 
 
 THE LOWEST STRATIFIED GROUP is peculiarly 
 distinguished by its chemical characters, produced 
 in many instances by the volcanic action it has suf- 
 fered. Some of these rocks are unstratified, and those 
 that are stratified usually lie at a very high angle. 
 
 Gneiss and mica slate are the two principal rocks of 
 this group; but with these, various subordinate ones 
 are associated. They cannot be said to take any regular 
 relative positions, but frequently pass into each other 
 in so gradual a manner, that it is oftentimes impossible 
 to say where one rock ceases and the other commences. 
 Gneiss, for instance, in some parts of lona, so much 
 resembles granite, that a specimen can only be deter-' 
 mined by a favorable fracture; and in another place, 
 where it loses its quartz, it gradually passes into horn- 
 blende slate. 
 
 Mica slate, sometimes called Micaceous Schistus, 
 usually superposes gneiss, and consists of quartz and 
 
PRACTICAL GEOLOGY. 47 
 
 mica, but contains garnets in so great abundance, that 
 they may be almost said to be an essential ingredient. 
 The prevailing colour of this rock is grey; it is in- 
 variably stratified, and the strata are sometimes greatly 
 contorted. It usually forms extensive tracts of moun- 
 tainous country, but the acclivities of its elevation are 
 not so bold and steep as those which are formed of 
 gneiss : it is beautifully exposed at Bolt Head and the 
 neighbouring headlands, on the coast of Devonshire. 
 
 Gneiss is that rock which usually superposes granite, 
 from which it can be distinguished only by the general 
 parallelism of its mica or hornblende, its composition 
 being generally the same. 
 
 The word gneiss is said to have originated with the 
 German miners; but it was Werner who limited the 
 term to the rock of which we are speaking. It often- 
 times forms mountains of considerable elevation, as at 
 Mont Rosa, in Italy, and the middle range of the 
 Pyrenees. Many of the western isles are composed of 
 it, and it abounds in Sweden, Russia, Greece, and many 
 other European countries. 
 
 Gneiss oftentimes presents the most curious appear- 
 ance, from the contortion of its strata and the presence 
 of veins. There is a singular instance of the former at 
 Cuire, in the island of Barra, which Dr. Mac Culloch 
 
48 OUTLINE OF 
 
 has described in his interesting work on the Western 
 Isles. 
 
 The composition of Gneiss differs but little from that 
 of Granite; its prevailing component minerals are quartz, 
 felspar, and mica, but hornblende and chlorite are 
 sometimes present. 
 
 It is universally allowed to be a stratified rock, but 
 all varieties do not present it in the same degree. 
 When the texture is coarse, the strata are indistinct; 
 and when it is traversed by granite veins, they can 
 scarcely be distinguished; but where the texture is 
 fine, and the minerals arranged in a parallel direction, 
 the strata cannot be mistaken. 
 
 In this general view of the stratified rocks, we have 
 endeavoured to dwell principally upon those facts 
 which are most important to the investigation we are 
 to enter upon. The study of Practical Geology from 
 books is, under all circumstances, uninteresting, and 
 particularly so when the author is compelled to take a 
 loose and unconnected view of the subject. To feel the 
 enthusiasm of a Geologist, it is necessary that know- 
 ledge should be acquired from nature. The elements 
 of the natural sciences, which must necessarily be 
 obtained in the study, need but a few hours' careful 
 attention, and the inquirer will afterwards gain more 
 
PRACTICAL GEOLOGY. 49 
 
 information from the inspection of a few specimens 
 in their localities, than from the perusal of many 
 books. 
 
 But before we pass from this subject, it is necessary 
 to make a few remarks upon the UN STRATIFIED 
 ROCKS. 
 
 These rocks are extensively distributed over the 
 globe, and are found in strata of all ages. Near 
 Friedau, in Styria, trachytic conglomerates super- 
 pose tertiary deposits; and in the north of Ireland, 
 immense veins, or dykes, of basalt traverse the chalk. 
 And in our own country the traps are associated with 
 nearly all formations. 
 
 The unstratified rocks are usually supposed to have 
 originated from the action of subterranean fire, and 
 hence it is we find them in veins as well as beds. 
 Sometimes, entire mountain chains are composed of 
 them ; and, generally speaking, they occupy the highest 
 portions of the globe. They have been divided into four 
 classes, and a general sketch of the granitic, serpentine, 
 and trappean rocks, may be given. 
 
 The Granitic rocks are chiefly composed of quartz, 
 felspar, and mica; and two or more of these are neces- 
 sary. Felspar is generally most abundant, but that 
 mineral, as well as all others which enter into their com- 
 
50 OUTLINE OF 
 
 position, varies in its proportions, and is sometimes 
 absent. A granite of Mont Blanc is composed of fel- 
 spar, quartz, and chlorite; we observed one in Aber- 
 deenshire, which consisted of felspar and hornblend; 
 and another in Perthshire, formed of quartz, felspar, and 
 actinolite. Mr. Poulett Scrope, in his work on Central 
 France, speaks of a granite which constitutes an exten- 
 sive tract in the department of Haute Loire and Ar- 
 dche, that contains so much pinite, that it is esti- 
 mated to form a third part of the whole rock. 
 
 Sienite, which is a variety of granite, differs from that 
 rock in having hornblend as a component part, instead 
 of mica. This rock occurs in Scotland, and in the Mal- 
 vern hills, but particularly in Charnwood forest. 
 
 DlALLAGE E,OCK AND SERPENTINE. 
 
 These two rocks are intimately connected together, 
 and pass into each other. Diallage consists chiefly of 
 diallage and felspar. Serpentine, so called from 'its 
 peculiarly variegated lustre, resembling a serpent's skin, 
 is a simple mineral substance. Its fracture is either 
 splintery or granular, and has a bright lustry appear- 
 ance when first broken. It is not extensively distributed, 
 and in England is only found at the Lizard Point. 
 
PRACTICAL GEOLOGY. 51 
 
 TRAPPEAN ROCKS. 
 
 The word trap is derived from a Swedish word 
 signifying stair, and is given to these rocks because 
 of their jagged appearance. They pass into each 
 other so rapidly and frequently, that it is almost im- 
 possible to enumerate, and quite impossible in many 
 instances to distinguish, the numerous varieties which 
 are thus formed. But we cannot pretend to give in 
 the following remarks, a description of the trappean 
 rocks, our only object is to show the great variety of 
 appearances they present, and the peculiarities of their 
 composition. 
 
 The principal rocks of this class are claystone and 
 clinkstone, chiefly composed of felspar; greenstone, 
 composed of augite and hornblend; and basalt, con- 
 sisting of augite and titaniferous iron; but the latter 
 is not definitely described. 
 
 The simple trappean rocks become porphyritic by the 
 admixture of quartz or felspar. The porphyries are 
 known by the name of their base; thus we have clay- 
 stone porphyry, clinkstone porphyry, and others. 
 
 Some trappean rocks appear to have been vesicular, 
 like the modern lavas; but these vesicles have been 
 since filled by mineral substances, having an almond 
 shape ; and are on this account called Amygdaloids. 
 
 E2 
 
52 OUTLINE OF 
 
 Sometimes the trappean rocks take a columnar 
 structure: the Giant's Causeway and Fingal's Cave, 
 equally celebrated for their picturesque beauty and 
 their singular geological appearance, are instances. 
 
 The Island of Sky, one of the Western Isles, affords 
 a most excellent opportunity for the study of the un- 
 stratified rocks. This beautiful spot, the Isle of Mist, 
 as it is called by the Gaelic poet, is equally worthy the 
 attention of the Geologist and the man who can in 
 any degree feel the influence of rugged mountainous 
 scenery. But it is chiefly upon the shores of this island 
 that the objects of the Geologist's investigation are ex- 
 posed to view. We can only mention one portion of this 
 interesting coast. From a point called Ru-na-braddam 
 to Loch Snizort, we have a series of cliffs, composed 
 of columnar trap, resembling those at the celebrated 
 cave of Staffa. "Although the columns are not so 
 accurately formed, nor so distinctly marked, as in other 
 places, their effect at the proper point of sight/* says 
 Dr. Mac Culloch, "is equally regular; while from tlie 
 frequent occurrence of groups, recesses, and projecting 
 masses, and from the absence of any superincumbent 
 load, they are far superior, in lightness of appearance, 
 as well as in elegance and variety of outline. In many 
 cases where the columnar trap lies above the horizontal 
 
PRACTICAL GEOLOGY. 53 
 
 strata, the appearance of architectural imitation is 
 much more perfect than in any part of Staflfa, the 
 stratified rocks presenting horizontal courses of natural 
 masonry; one of which, from a Darticular point of 
 view, so exactly represents the general proportions and 
 character of a circular temple of Grecian architecture, 
 that the artist who should represent it truly, would 
 be suspected of forcing nature into the forms established 
 by art." 
 
 Those who have objected to the igneous origin of 
 unconformable rocks, urge two reasons for their differ- 
 ence of opinion: that they are sometimes found im- 
 bedded in the stratified rocks, and that they sometimes 
 pass by gradation into the stratified primitive rocks; 
 from which it would follow, that these also had an 
 igneous origin, which deduction would extend the reign 
 of Pluto over too large a portion of the mineral masses. 
 If these are the best arguments that the Neptunists can 
 adduce, we are bold to say, they are nothing worth and 
 scarcely deserve notice. With regard to the first 
 objection it may be stated, that it is not strange that 
 unconformable rocks are enclosed in stratified beds, 
 and the fact only proves that the upper beds were 
 formed after the overflowing of the unstratified mass. 
 And with regard to the other objection, we may remark 
 
54 OUTLINE OF 
 
 that there is nothing to fear from the extension of 
 Pluto's reign, if we are warranted by facts ; for the only 
 object of a Geologist should be to deduce fair infer- 
 ences from geological phenomena. 
 
 To obtain an accurate acquaintance with the charac- 
 ters and superposition of rocks, will occupy some time, 
 and requires considerable attention. But all the fun- 
 damental principles of the science are comprised in the 
 four following propositions : 
 
 1. The crust of the earth is composed of a series of 
 rocks, some of which are stratified, and some unstra- 
 tified. 
 
 2. The stratified rocks have a regular succession, but 
 are often disturbed by the unstratified, which occur in 
 all parts of the series. 
 
 3. Nearly all the stratified rocks, excepting a few 
 which are found at the bottom of the series, contain 
 organic remains. 
 
 4. Every bed which contains organic remains has 
 some that are peculiar to it, and by them it may always 
 be distinguished. 
 
THEORETICAL GEOLOGY. 55 
 
 OUTLINE OF THEORETICAL GEOLOGY. 
 
 THE ultimate object of Geology, as before stated, is to 
 gain some information concerning the formation of the 
 world, the causes employed, the circumstances under 
 which these causes acted, and the physical condition 
 of the earth at each successive period of its existence. 
 To gain this knowledge, we trace the superposition of 
 rocks, the disturbances they have suffered, and the 
 organic remains they contain. The facts which Geo- 
 logists have discovered are, therefore, only the rudi- 
 ments of their science, the principles to which the pro- 
 cess of induction must be applied. 
 
 The first deduction to which we seem to be led is, 
 that rocks were, in all probability, formed by agents 
 resembling those that still exert their influence on the 
 globe. If we were to take a view of the harbours on 
 our own shores, or the rivers which are every where 
 winding their courses between our rich and cultivated 
 hills, we should see that, in different situations, various 
 local and general causes were in action producing cer- 
 tain effects. Water is every where charged with a con- 
 siderable quantity of sandy or earthy matter, which 
 
56 OUTLINE OF 
 
 it obtains from the degradation of land, and is constantly 
 depositing. In this way the beds of rivers are filled, 
 and rendered unnavigable, and the finest harbours are 
 destroyed: innumerable instances of both will imme- 
 diately recur to the mind. 
 
 In Lincolnshire, and other counties where the land is 
 beneath the level of high water mark, unfruitful soils are 
 constantly restored to a state of fertility by the simple 
 process of introducing the water upon the land. The 
 water being overcharged with argillaceous matter, de- 
 posits in two or three years, a bed, five or six feet thick, 
 of rich and fertile soil. This is an illustration of the 
 manner in which argillaceous strata are still forming, 
 under the influence of common existing causes. And 
 who is to determine the difference between this deposit 
 after it has been subjected for a time to the evaporating 
 influence of the sun, and those formed in an earlier period 
 of the history of the earth ? We are therefore warranted 
 by analogy in supposing that the argillaceous strata of 
 the globe may have been formed by deposition frtim 
 oceans and rivers, and by those other causes which are 
 now instrumental in producing analogous beds. 
 
 Many instances of the influence of running waters in 
 depositing new strata might be given. So rapid and 
 considerable is this process, that it is not at all un- 
 
THEORETICAL GEOLOGY. 57 
 
 common for rivers to destroy their own courses. The 
 Oxon, or Jihon, which not long since flowed into the 
 Caspian sea, now throws itself into the lake Aral. The 
 Burrampooter has changed its course in that part where 
 it formerly united with the Ganges, and joins that river 
 ninety miles distant from the place of its former union ; 
 and the Euphrates and Tigris now take in part the 
 same course, although, in the time of Nearchus, they 
 occupied different channels. 
 
 Major Rennell, in an enquiry into the situation of 
 Tomis, the place to which Ovid was banished, has 
 entered into an interesting investigation of the former 
 course of the Danube. The main branch of this river, he 
 supposes to have ran by Tomis ; for the ancient channel, 
 which is of great breadth, may be traced from Cherna- 
 voda, on the Danube, to the neighbourhood of Baba, or 
 Tomis. Along the whole line a chain of small lakes, 
 sometimes connected by channels, have been observed, 
 and these, it is supposed, are still supplied by the floods 
 of the Danube. 
 
 "From what is known to have happened to certain 
 other rivers, we may readily trace out the circumstances 
 of the above changes: that the Danube, by creating 
 impediments to its own course, by raising the level of 
 the soil in that line, sought a lower level elsewhere. * 
 
00 OUTLINE OF 
 
 " It is not to be supposed that the change was sudden 
 and total, but slow and gradual; at first only such a 
 portion of the waters as the contracted state of the old 
 channel would not readily admit, ran out; but as the 
 new one would be gradually enlarged by corrosion, so 
 the other one would be filling up from the diminished 
 force of its stream, which rendered it less and less able 
 to remove the obstructions, until the whole would be 
 drawn into the new channel. In tropical climates, such 
 changes are sometimes the work of a single season." 
 (Comparative Geography of Asia, vol. II. pp. 374. 378.) 
 In the same manner, siliceous deposits are still 
 forming* It is not always easy to determine the local 
 causes which influence the character of a deposit, yet it 
 may be frequently seen, that in one place a river will 
 deposit an argillaceous, and in another, a siliceous bed. 
 At the mouth of the estuary of Saltcombe, on the Devon- 
 shire coast, to the west of Bolt head, there is a conside- 
 rable accumulation of sand, called the Bar, from which 
 the inhabitants of the neighbourhood have been for a 
 long time removing many thousand tons every year, yet 
 without any apparent reduction of the accumulated 
 mass. But higher up the estuary, we find a deposition 
 of argillaceous matter, so extensive as to prevent vessels 
 of any considerable burthen, and such as formerly visited 
 
THEORETICAL GEOLOGY. 59 
 
 it, from approaching. By a geological examination of 
 this district, we found that the water of the estuary has 
 its bed in an argillaceous slate, and the slate rocks are 
 for a considerable distance exposed to its degrading 
 effects. We are well aware of the influence of rivers on 
 their banks, and therefore it is more than probable that 
 the argillaceous bed which has choaked the estuary of 
 Saltcombe, is the accumulation of detritus, formed and 
 deposited by the river. But the whole of the coast 
 beyond the Bolt head, as well as the rocks at the mouth 
 of the estuary, are composed of mica, chlorite slate, 
 and quartz; and their presence may probably account 
 for the accumulation of sand at the bar. 
 
 In taking a general view of the causes which influence 
 the character of a deposition, we are inclined to suppose 
 that they are generally local ; sometimes it may depend 
 immediately upon the character of the rocks, of which 
 the district may be composed, and at other times may 
 result from currents. Of the latter, we have an excellent 
 example in the Dogger Bank, which extends from north 
 to south more than 350 miles, and is supposed to be an 
 accumulation of debris, carried by tides and currents. 
 
 Argillaceous and siliceous beds are, therefore, still 
 forming, and so entirely resemble those which are found 
 in the crust of the globe, that we cannot possibly doubt 
 
60 OUTLINE OF 
 
 that they were formed by the same agents. Under a 
 conviction of the truth of this statement, geologists 
 determine upon the manner in which any bed was formed, 
 by applying known causes wherever they are sufficient 
 to account for the phenomena observed. 
 
 Modern and ancient calcareous beds also present such 
 similarities of appearance, as will not leave room to 
 doubt that they were formed by the same agents. It 
 is not, however, so easy to draw the comparison in this 
 instance as in those we have mentioned. There are 
 various sources from which lime is obtained, and causes 
 occasioning its deposition. But the calcareous deposits 
 are so extensive in the secondary class, that none of the 
 agents now existing, separately considered, could, in 
 the present state of things, have produced them. We 
 shall, however, in a subsequent part of this essay, have 
 occasion to advert to circumstances which will tend 
 to show that the temperature of the earth was much 
 higher during the deposition of the antediluvian rocks, 
 than at present : bearing this in mind, we shall probably 
 be of opinion that the causes now in activity, were to- 
 gether sufficient to have formed all the calcareous rocks. 
 
 But if we were altogether unable to maintain by 
 actual examinations our proposition in relation to the 
 calcareous deposits, yet from analogy we should con- 
 
THEORETICAL GEOLOGY. 01 
 
 elude, that, as all the rocks with which they are asso- 
 ciated, were formed by causes resembling those which 
 are still in action, so the calcareous beds must have ori- 
 ginated in every age from existing agents. We may, 
 however, find it interesting to enquire, how calcareous 
 deposits are now formed, and to examine the theories 
 which have been invented, to account for the older strata 
 of the same character. 
 
 Calcareous deposits may in some instances be formed 
 by the destruction of calcareous rocks. The action of 
 the air is sufficient to crumble them in a great degree; 
 but it is somewhat difficult to determine the precise, 
 causes of the destructive effects of the atmosphere. 
 Water is certainly the principal agent ; for, as the drop- 
 ping of rain, after a lengthened period, wears away 
 the hardest stones, so the action of atmospheric water 
 tends to destroy the particles of rocks. The rocks in 
 the higher regions are particularly exposed to atmos- 
 pheric influence, its effects being considerably increased 
 by the variation of temperature. Frost is a most power- 
 ful agent: when water penetrates into the cavities of 
 rocks, and freezes, the expansion of the liquid rends 
 asunder the most solid masses with inconceivable force, 
 and their superficies are not less exposed to the crum- 
 bling effects of the same agent. Hence it is that the 
 
62 OUTLINE OF 
 
 rocks of colder climes, which are little exposed to the 
 action of water, suffer such extensive degradation. There 
 are several instances of the weathering of hard rocks in 
 our own country : the Tors of Dartmoor, in Devonshire, 
 which are composed of granite, and the Logan stones, 
 supposed by some persons to be the work of the Druids, 
 are excellent examples. 
 
 But the atmosphere has also certain chemical effects 
 upon rocks. Atmospheric water has a considerable 
 influence upon calcareous beds, especially when it con- 
 tains carbonic acid in solution, as all persons who have 
 been accustomed to a chalk or limestone district, are 
 well aware; but when these rocks are exposed on the 
 sea coast, or by the banks of a river, to the action of 
 running water, the degradation is still greater. 
 
 By all these causes, calcareous rocks are destroyed; 
 and by heavy rain or springs, the detritus is carried into 
 the lakes, rivers, or seas, that may be in the neigh- 
 bourhood. Part of this is, no doubt, deposited, but not 
 so large a quantity as may at first be supposed. 
 
 When we remember how large a quantity of lime is 
 taken up by crustaceous and testaceous animals, it will 
 at once appear that a large proportion of that which is 
 carried into the sea by various destroying agents, is 
 thus employed. Shell fish, as is well known, cannot 
 
THEORETICAL GEOLOGY. 63 
 
 form their coverings, without lime be present in the 
 water; and when we consider the immense variety and 
 number of this interesting class of animals, we shall 
 find no difficulty in appropriating a considerable portion 
 of that which is carried into the sea to their use ; and 
 at the same time we cannot deny the coralloides their 
 share of the booty which they so admirably employ, and 
 other classes of the inhabitants of the deep, who require 
 it, though in a less quantity. 
 
 Taking these things into consideration, it is probable 
 that but few limestones are formed in the present day 
 by the degradation of rocks. The most considerable 
 calcareous deposits are those which are produced by 
 springs and by polypifers. 
 
 Most springs arise from the percolation of water 
 through rocks. The atmospheric waters upon reaching 
 the earth may, for instance, pass through a series of 
 porous beds, but afterwards meeting with an impervious 
 clay, or some other impenetrable body, take their course in 
 the direction of the strata, and thus make their escape. 
 Or they may form a passage for themselves at some 
 place beneath the level of the enclosed waters. 
 
 Springs are all more or less impregnated with the 
 substances through which they pass, and deposit the 
 mineral matter which they hold in solution, in their 
 
64 OUTLINE OF 
 
 courses. But some are less pure than others, and 
 have, consequently, obtained the name of mineral 
 springs. Many of these are cold, and the majority are 
 perhaps derived from the same source as those which 
 contain a less quantity of mineral matter. Others are 
 thermal, and are generally supposed to be of volcanic 
 origin. Carbonate, sulphate, and muriate of lime, 
 soda, silica, and other substances, are found in these 
 springs. 
 
 James informs us, in his Rocky Mountains, that the 
 thermal springs ofWashita contain silex, lime, and iron; 
 and those in the valley of Pyrmont hold magnesia, lime, 
 iron, and soda. Sir George Mackenzie and other writers 
 on Iceland inform us that the Geysers deposit so large a 
 quantity of silex, that the neighbouring vegetation is in- 
 crusted with flint. But the most remarkable deposition 
 of silex is that at St. Michael's, one of the Azores. Dr. 
 Webster discovered a bed of reeds, similar to ethos now 
 flourishing on the island, entirely petrified. (Edinb. 
 Phil Journal, vol. vi. p. 310.) 
 
 It is difficult to determine how the solution of silex is 
 effected ; but we have many instances of its occurrence 
 in the vegetable kingdom, for which it would be equally 
 difficult to account. Many of the grasses, canes, and 
 other plants, particularly the green bamboo, contain it 
 
THEORETICAL GEOLOGY. 65 
 
 in large quantities. But lime is the most common and 
 most abundant deposit of mineral springs. At San 
 Vignone, in Tuscany, there is a thermal spring of great 
 heat, which deposits a large quantity of calcareous 
 matter. One stratum, according to Mr. Lyell, is fifteen 
 feet thick, and is used for architectural purposes. And 
 so rapid is the deposition near the source, that a foot of 
 solid travertine is formed yearly in the pipes that con- 
 vey the water into the baths. (Ly ell's Principles of 
 Geology, vol. i. p. 202.) 
 
 This single example will be sufficient to prove that a 
 considerable quantity of calcareous matter must be 
 deposited by thermal springs, for it is not an extraor- 
 dinary occurrence; nor are the cold springs entirely 
 inactive in the deposition of lime. Upon the flat lands 
 above the celebrated falls of Terni, according to Mr. 
 De la Beche, (Manual of Geology, p. 137,) which 
 were artificially formed, a considerable deposit of lime 
 has taken place; and in the country around there are 
 many examples of the deposition of travertins by springs. 
 
 Mineral springs are generally supposed to be in some 
 manner connected with volcanic agency, though they 
 are still attributed by some to the passage of water 
 through destructible rocks. There are certain springs 
 which, from their immediate connexion with volcanos, 
 
66 OUTLINE OF 
 
 or situation in countries which have experienced the 
 effects of their action, may certainly be said to have 
 some intimate relation to the same cause. Such are the 
 Geysers of Iceland, an island equally remarkable for 
 the abundance of its hot springs and the violence and 
 number of its volcanos. There are other springs, of 
 which we must speak more cautiously, as circumstances 
 seem rather to induce the supposition that they derive 
 their heat and minerals from other causes, as the mineral 
 springs of Buxton and Bath. 
 
 It is a question then of some importance, we think, 
 to determine whether all mineral springs have the same 
 origin; and if it be discovered they do not, to acquaint 
 ourselves with the general phenomena by which they 
 may be determined. At present, our knowledge on 
 this subject is very imperfect, and opinions are rather 
 derived from prejudice than proof. 
 
 The principal arguments for the volcanic origin of 
 mineral springs are the following : 
 
 1. That, like volcanos, they are generally distributed, 
 and occur in all rocks, from the oldest granite to the 
 newest tertiary. 
 
 2. That nearly all the ingredients found in mineral 
 springs occur as sublimates in volcanos. 
 
THEORETICAL GEOLOGY. 67 
 
 3. That gaseous exhalations accompany both mineral 
 springs and the activity of volcanos. 
 
 4. That violent earthquakes, which are undoubtedly 
 connected with the volcanic cause, influence mineral 
 springs, even when situated at a great distance from 
 the seat of convulsion. 
 
 5. That volcanic eruptions are frequently accom- 
 panied by the bursting out of new thermal springs, 
 which cease with the volcanic action, and return periodi- 
 cally, like the eruptions themselves. 
 
 As our object is not so much to investigate the cause 
 of the agents which are still effecting changes on the 
 surface of the globe as their effects, we cannot enter more 
 at large into this interesting inquiry. In estimating the 
 influence of mineral springs in the deposition of lime, 
 we are led to suppose that their effects are not incon- 
 siderable, though local; but, if it should be demon- 
 strated that they arise from the volcanic cause, the 
 extent of their deposits would be regulated by the inten- 
 sity of that all-important agent. 
 
 From a knowledge of these facts, we shall not be sur- 
 prised when we observe in the solid strata of the globe, 
 limestones connected with volcanic rocks. This is not 
 of unfrequent occurrence, and although we cannot 
 
DO OUTLINE OF 
 
 assert that all limestones thus associated were pro- 
 duced from springs, yet there are frequently reasons for 
 this conclusion. 
 
 If we take into consideration the greater surface 
 temperature of the earth at a former period than at 
 present, and the greater activity of the volcanic cause 
 as exhibited by rocks, we shall have an additional 
 reason for attributing to mineral springs the formation 
 of many of our calcareous deposits. Nor need we be 
 surprised at the presence of silex, as the springs of St. 
 Michael afford us a proof of the same phenomena. 
 
 But coralloides are, in all probability, the most active 
 agents, of the present day, in forming calcareous depo- 
 sits. The extensive reefs which are formed by these 
 little creatures is almost beyond imagination. But they 
 do not, as is usually supposed, raise their work from the 
 bottom of the sea, for several genera cannot exist at 
 great depths; they fix themselves upon some sub- 
 aqueous elevation, and erect their dwellings upon it. 
 This will account for the great depth of water whioh 
 has often been observed in the immediate vicinity of 
 coral reefs. The supposition that considerable districts 
 at the bottom of the sea are covered with coral rock is, 
 therefore, erroneous. 
 
 Coral reefs are not entirely composed by the litho- 
 
THEORETICAL GEOLOGY. 69 
 
 phytes. The remains of shell-fish are, as might be 
 expected, frequently found in them, and the whole is 
 cemented together by calcareous sand, produced by the 
 pulverization of shells. In this way coral rocks are 
 formed, until they rise just above the level of the sea, 
 when they are abandoned by the insignificant artificers. 
 
 It has been observed by modern navigators, that coral 
 rocks, in some situations, take an oval or circular form. 
 This is supposed to arise from their fixing themselves 
 upon the summits of sub-marine craters; and as we 
 are acquainted with the presence of volcanic vents in 
 all the seas where this peculiarity has been observed, it 
 is not an improbable supposition. In the Isle of France 
 a bed of coral ten feet thick has been observed, lying 
 between two currents of lava. And Captain Beachy 
 states that Ducie's Island, which is composed of coral, 
 is of an oval form, with a lake of very considerable 
 depth in the centre. 
 
 In closing our observations upon the causes which 
 are now producing calcareous deposits, we shall only 
 refer to Mr. LyelFs description of the recent beds of 
 shell marl and limestone at Bakie Loch, Forfarshire, 
 which is an instance of the united effects of testaceous 
 animals and calcareous springs. 
 
 The shell marie is of a yellowish white colour, and 
 
70 OUTLINE OF 
 
 contains the horns of stags and bulls, as well as the 
 shells of the helix, turbo, limnea, and other fresh-water 
 testaceous animals. No stream enters the lake, but it 
 is fed by those which are irregularly distributed over its 
 bed ; and in the vicinity of these springs, the deposit is 
 purely calcareous. 
 
 The limestone is of the same colour as the marie, and 
 consists almost entirely of carbonate of lime, which is 
 hard and compact. Remains of a vegetable called the 
 chara, (the chara hispida,) were found in this deposit. 
 
 The Bakie Loch is situated in a district entirely com- 
 posed of sandstone; and the water of the principal 
 spring, which rises at the bottom of the loch is, accor- 
 ding to an analysis by professor Daubeny, "remarkably 
 pure and exempt from mineral contents. The specific 
 gravity exceeds that of distilled water, by less than -g^th 
 part, and when evaporated in an exhausted receiver, it 
 bears only -soVo^h* This residuum consists chiefly of 
 dark coloured vegetable matter, but it must also con- 
 tain lime, since oxalate of ammonia renders the water 
 turbid; the presence of carbonic acid is very evident/' 
 (Geol. Trans. N. S. p. 80.) 
 
 If so minute a quantity of calcareous matter be present 
 in the water, it is quite certain that the beds referred to 
 could not have been formed by deposition from it, unless 
 
THEORETICAL GEOLOGY. 71 
 
 it formerly contained a much larger quantity than at 
 present. Mr. Lyell, therefore, supposes the shell marie 
 to have been formed by the testaceous animals, whose 
 remains are found ; and that they derived the lime which 
 is necessary for them, from the springs, or the charse. 
 Allowing that a sufficient quantity of lime was thus 
 produced for the animals to exist in the waters, they 
 may have formed the shell marl ; and it is evident that 
 when a bed of the shell marl had been deposited, the 
 carbonic acid would form a solution of that bed, and 
 produce the limestone. 
 
 From these observations it will appear that the cal- 
 carious deposits which are now forming, arise from 
 either the degradation of rocks, deposition from springs, 
 or the accumulation of the remains of testaceous 
 animals. The coral rock is certainly the most exten- 
 sive formation, but it must be borne in mind that all 
 testaceous animals assist, in some degree, in the pro- 
 duction of coral reefs. 
 
 Having taken this general view of the causes which 
 are still producing calcareous deposits, we may refer to 
 some of the theories which have been invented to 
 account for the formation of the more ancient beds. 
 That all the agents we have mentioned contributed to 
 
72 OUTLINE OF 
 
 the production of the fossiliferous cretaceous rocks, 
 there can be no doubt; and it is equally certain that 
 they acted under circumstances which promoted their 
 activity. The great error into which geological theo- 
 rists have fallen is, that they have attributed the pro- 
 duction of a whole series of rock to an individual 
 cause, instead of tracing the union of agents, and 
 determining upon the one which has been most effective. 
 Unfortunately, we are compelled in our endeavour to 
 simplify science, to examine causes in their individual 
 characters, although they are combined in nature, and 
 greatly modify each other. 
 
 It has been maintained by some persons, that the 
 limestones were formed from the destruction of pre- 
 existing rocks. If this had been the only cause in 
 action, we should expect that calcareous deposits would 
 decrease in quantity as we ascended in the scale of 
 rocks; but instead of this being the case, the lime- 
 stones seem to increase the higher we ascend. But if 
 it should be supposed that so large a quantity of thfe 
 older rocks were exposed at each successive formation 
 ' as to give an increased quantity to the higher portions 
 of the series, and that this was universal, we are still 
 unable to account for the local characters with which 
 
THEORETICAL GEOLOGY. 73 
 
 they are often impressed, or to reconcile it with the 
 various appearances they present. 
 
 It has also been supposed that they resulted from the 
 exuvia of testaceous animals. To this it has been 
 objected that all testaceous and crustaceous animals 
 require a supply of carbonate of lime to form their 
 coverings, which are supposed to constitute the lime- 
 stone. If we endeavour to account for this necessary 
 supply of lime from its presence in the vegetables they 
 use as food, it is at once evident that the theory must 
 be erroneous, for their food could not have contained 
 more lime than similar vegetables in the present day; 
 and we do not find that limestones are now formed by 
 testaceous animals under the same circumstance. Nor 
 could the medium in which they lived have contained 
 more lime than the waters of the present day, for then 
 it would have been gradually exhausted by the animals 
 who were extracting from it, and limestones would neces- 
 sarily be less numerous the higher we ascend in the 
 crust of the earth. 
 
 But, independent of these arguments, there is an 
 improbability about the supposition, particularly when 
 we take into consideration the relative positions of the 
 limestone deposits. Yet there can be no doubt that 
 coralloides and shell-fish contributed in no ordinary 
 
74 OUTLINE OF 
 
 degree to the formation of many of our calcareous 
 rocks; we might mention the coral rag, among others. 
 
 Another supposition is, that the limestones were pro- 
 duced by the passage of water containing carbonic 
 acid through pre-existing rocks. This, in all proba- 
 bility, was the origin of many small local deposits, but 
 is evidently quite insufficient to account for those 
 immense collections of limestone rock that are spread 
 over the whole surface of the globe. For if the lime 
 deposited in this way could account for all limestones, 
 then it would appear that the small quantity obtained 
 from pre-existing rocks, by springs, could form a mass 
 larger than that from which it was taken ; but the lime- 
 stones, as already stated, are more abundant in the 
 upper than the lower parts of the earth's crust. 
 
 But, although neither of the above theories can 
 account for the formation of all limestone rocks, yet 
 they may all have been employed, sometimes unitedly, 
 and at others separately. 
 
 "Lime," says Mr. De la Beche, "has been derived 
 somewhere, and we have reason to believe from the 
 interior of the earth, otherwise, there is a difficulty in 
 explaining the observed phenomena. The reason why 
 extensive tracts of carbonate of lime have been pro- 
 duced at one time more than another, is not quite so 
 
THEORETICAL GEOLOGY. 75 
 
 apparent; but it may be observed, as a mere conjecture, 
 that as this substance is not very unfrequent in volcanic 
 regions, great disruptions of strata may have produced 
 circumstances favorable to its deposition; and that 
 without disturbances, carbonate of lime may have been 
 thrown upwards in water, through fissures, more abun- 
 dantly at one time than at another, from causes un- 
 known to us." 
 
 All these theories are founded upon the admission of 
 the principle for which we are arguing. Allowing that 
 rocks in all ages have been formed by the same causes, 
 Geologists have investigated into the nature of those 
 which are still active, and applied them to the deposits 
 which are found among the solid strata of the globe. 
 To determine which of these we have referred to have 
 been chiefly instrumental in particular instances, we 
 must observe the general appearance the bed presents, 
 the nature and situation of the deposit, the state of the 
 earth during its formation, and the character of its fossils. 
 
 In order to ascertain the manner in which beds of 
 gravel and conglomerate were formed, we have only to 
 trace the influence of violent storms upon mountain 
 chains, or even the effects of running water upon sili- 
 ceous substances, to see that causes are still in action 
 producing similar deposits, 
 
76 OUTLINE OF 
 
 The ruin and desolation of nature which accompanies 
 a hurricane, which is one of the violent agents of de- 
 struction, is almost beyond description. It may gene- 
 rally be foretold, like the volcano, by a peculiar stillness 
 of the air; but there is also a mistiness of the atmos- 
 phere, which gives the sun a dark red tinge; the sky 
 is soon overcast, the clouds gather together with a wild 
 appearance, the wind rises fiercely, and the waves are 
 tumultuously tossed over each other in the most un- 
 governed confusion. The rain then descends in torrents, 
 and all nature is wrapt in darkness, that is only pene- 
 trable by the vivid lightning. The animal, vegetable, 
 and mineral, world, all suffer under its rage: rocks are 
 broken into fragments, and scattered around; every 
 plant and tree is uprooted, and the animals are either 
 suffocated by the wind or buried in the ruins around 
 them. Thus, in a few hours, the most fertile district is 
 turned into an uninhabited wilderness. Such is the 
 character of the hurricanes that so often afflict the 
 West India Islands. By this, as well as more mode- 
 rate means, rocks are destroyed, and when the frag- 
 ments have been rounded by attrition, they are collected, 
 and form gravel, or conglomerate beds. 
 
 That beds of gravel and other strata containing 
 rounded pebbles, were formed by the action of water, is 
 
THEORETICAL GEOLOGY. 77 
 
 quite certain. If we examine the stones which lie upon 
 the shores of the sea, and the margin of lakes, we 
 uniformly find them smoothed by the action of the 
 waves; and we can have no better proof of the former 
 existence of a water-course than the presence of rolled 
 pebbles. We therefore conclude, when we find beds of 
 gravel among the solid strata of the globe, that, by the 
 force of conflicting waters, hurricanes, or other violent 
 causes, rocks have been broken and disintegrated ; that 
 those fragments which could not resist the solvent 
 principle of the water have been taken up by it; and 
 that those which have been of such a chemical compo- 
 sition as to prevent solution, have been rolled ; and that 
 the argillaceous or other matter held in solution has 
 been afterwards deposited upon the rolled pebbles. 
 This process is still going on in the beds of many rivers, 
 and we therefore think ourselves warranted in supposing 
 that those of antecedent date had the same origin. 
 
 These observations are entirely confined to the fossi- 
 liferous stratified rocks, and the same course of argu- 
 ment cannot with propriety be applied to those that are 
 destitute of fossils, for the majority present a chemical 
 appearance and characters which are not observed 
 in any deposits of more recent formation. 
 
 It is not surprising that in the early ages of Geology, 
 
78 OUTLINE OF 
 
 the minds of men were tortured with imagining the 
 causes which could have operated in producing the 
 several phenomena they observed; and when we re- 
 member the tenacity with which men hold their 
 opinions, it will not appear singular that they should 
 be unwilling to renounce their first impressions. This 
 premature deduction from isolated facts has given rise 
 to a variety of opinions, on every theoretical branch of 
 our science, which differ from each other as much as if 
 they concerned different subjects. "Yet," says De Luc, 
 "if there be a science in which advances ought to have 
 been made with that scrupulous caution so judiciously 
 recommended by Bacon, it is Geology; for the history 
 of the earth is inseparably connected with that of man." 
 
 There are three opinions which have been maintained 
 concerning the formation of the non-fossiliferous strati- 
 fied rocks: that they were deposited from fluid; that 
 they were produced by the action of fire; and that they 
 were created, in situ, as we now find them. 
 
 "The first formations," says D'Aubuisson, "wefe 
 produced by a general cause. We can represent them 
 to ourselves as precipitations from an universal disso- 
 lution, that is to say, from a dissolution that covered 
 the whole terrestrial globe. While this dissolution de- 
 posited one substance, or one rock, in one place, it is 
 
THEORETICAL GEOLOGY. 79 
 
 very possible that it produced no precipitate of the same 
 species in another; either because the constituent prin- 
 ciples of the rock were not in sufficient quantities in 
 that part of the dissolution, or because the causes of 
 the precipitation did not there exercise their action, or 
 lastly, because other causes obstructed them. In this 
 place, they deposited granite ; a little further, mica slate, 
 because the elements of mica were, perhaps, in a greater 
 quantity in that part of the dissolution which covered 
 the latter place." 
 
 Other writers have maintained the igneous origin of 
 all the non-fossiliferous rocks; but it is not probable 
 that any geologist of the present day would defend 
 such an opinion. But professor Mitsherlich has conside- 
 rably extended our knowledge of the effect which fire 
 has had in the formation of some of the non-fossiliferous 
 stratified rocks, as well as those which are unstratified. 
 This celebrated chemist, when making some inquiries 
 at Fahlun, concerning the extraction of copper, found 
 that the scoriae often contained some well defined 
 crystals, and that the whole mass of the clay had a 
 crystalline texture; and in almost every foundery that 
 he afterwards visited, he observed crystalline combina- 
 tions, which resembled minerals. By pursuing the 
 inquiry into which his mind was thus led, he succeeded 
 
80 OUTLINE OF 
 
 in forming by fire, a great variety of mineral substances, 
 among which mica and other constituents of rocks are 
 mentioned. From these discoveries he was led to the 
 conclusion that many of the non-fossiliferous stratified 
 rocks were produced by fusion, which, he says, affords 
 an easy explanation of the increase of temperature, as 
 we proceed into the interior of the earth, as well as of 
 hot springs, and other phenomena. 
 
 Mr. Penn and his school, suppose these rocks to 
 have been called into existence by the almighty fiat, 
 by an immediate simultaneous operation. He denies 
 the interference of all secondary causes, and considers 
 them as parts of the earth, as it came from the hand of 
 its Creator. 
 
 That this world was created by the almighty fiat, at 
 once, in a moment, and without any secondary causes, 
 is, we think, a proposition that cannot be controverted; 
 but we are unable to say that the non-fossiliferous 
 stratified rocks are parts of that world. Of this, how- 
 ever, we may be quite certain, that if they are parts of 
 the primitive earth, they have suffered great changes 
 from the action of both aqueous and igneous causes. 
 
 We have thus endeavoured to prove, that all the 
 fossiliferous stratified rocks were formed by causes 
 that are still productive in the formation of strata. It 
 
THEORETICAL GEOLOGY. 81 
 
 has also been stated that during the deposition of these 
 rocks, circumstances were more favourable to extensive 
 and rapid results than at present, chiefly on account of 
 the greater surface temperature. 
 
 The non-fossiliferous unstratified rocks appear to 
 have been produced by certain chemical laws, which 
 have had a contemporaneous operation over the entire 
 surface of the earth, and that at a time previous to the 
 existence of animal and vegetable life. 
 
 But all the stratified beds are considerably disturbed 
 by the unstratified rocks, which are continually found 
 among them, both in the form of beds and veins. It 
 may not, therefore, be improper, before we pass from 
 this part of our subject, to dwell upon the causes which 
 produced them. 
 
 There has been great dispute among geologists 
 whether these rocks were formed by fire or water; but 
 this question may now be considered as decided. Both 
 from their vitreous appearance and their resemblance 
 to modern lavas, it is quite certain that they had an 
 igneous origin. 
 
 The principal difference between the development of 
 volcanic agency during the formation of the stratified 
 rocks, and in the present day, consists in this circum- 
 stance, that lava was formerly ejected through wide and 
 
82 
 
 OUTLINE OF 
 
 extensive fissures, and now makes its escape from aeon- 
 fined crater. This enables us to account for the im- 
 mense beds we sometimes find between stratified de- 
 posits. A rent in the solid rocks, perhaps many miles 
 in length and of considerable width, has been first 
 effected by the volcanic cause ; the heated rocks have 
 then rushed upwards like a torrent, and flown over the 
 surface. A new order of things has afterwards arisen, 
 and in process of time stratified beds have been formed 
 upon the volcanic rock. 
 
 Veins may have been formed in two ways, by ejection 
 from below, or by intrusion from above. Let us sup- 
 pose a mass of overlying rocks to be rent by volcanic 
 force ; the violent disturbance necessarily dislocates and 
 cracks the whole mass in various places. Through 
 some of the fissures which conduct to the surface, the 
 intumescent mass is ejected, and flows over the super- 
 posing bed; but, immediately the opening is formed 
 and the lava begins to flow, all those smaller fissures 
 which are not connected with the surface, are filled, ancl 
 form injected veins. The other method by which veins 
 may have been formed, is by intrusion; for if fissures 
 should exist on a surface over which lava flows, they 
 must necessarily be filled by the liquid rock. 
 
 That this has happened from volcanic action in the 
 
THEORETICAL GEOLOGY. 83 
 
 early ages of the world, we are quite assured, from 
 actually tracing the veins through successive formations. 
 And if any further proof of the prevalence of igneous 
 causes during the deposition of strata were required, we 
 might refer to the influence which unstratified rocks 
 have had in upheaving them, and forming mountain 
 chains. 
 
 Being satisfied as to the manner in which these rocks 
 were formed, it may be useful to enquire into the dis- 
 tribution of the volcanic agent in the present day, the 
 character of the rocks formed, and the cause which pro- 
 duces the ejection. 
 
 Volcanos have been observed to occur in three dis- 
 tinct relative positions. Sometimes they are isolated, 
 or stand separate from all others; such are Etna, and 
 the Peak of Teneriffe. Sometimes they are found in 
 irregular groups; this is the case with many of those 
 situated in islands; and at other times they are ranged 
 in right lines, which is the position of the South 
 American volcanos, and suggested to Humboldt the 
 probability of their being ranged over an immense 
 chasm of volcanic matter. 
 
 It is a striking fact that the greater number of active 
 volcanos are in islands, many of which appear to have 
 derived their origin from successive eruptions. This 
 
 G2 
 
84 OUTLINE OF 
 
 accounts for the fewness of the sub-aqueous volcanos. 
 When we consider how much greater surface is covered 
 by water than by land, it at first appears singular that 
 so few should be found beneath the sea. But this is 
 easily explained : the action is not less violent beneath 
 the water than above it; but from the violence of the 
 volcanic cause, islands are raised. 
 
 Those volcanos which are situated on our continents 
 are either in the immediate neighbourhood of the sea 
 or some large salt-water lake. Some of the American 
 volcanos seem to be exceptions to this general rule ; but 
 these are universally connected with other mountains, 
 which have water in their vicinity; and it has therefore 
 been supposed that there is an internal connexion 
 between them. Jorullo, for instance, is at a considerable 
 distance from the sea, yet it is connected with the 
 Atlantic by Tuxtla, and with the Pacific by Colima. 
 
 It therefore appears that there is some connexion 
 between the presence of water and the activity of the 
 volcanic cause : what influence the fluid may have in 
 promoting eruption, we cannot pretend to determine; 
 but if we examine the situation of volcanic rocks in the 
 ancient strata of the globe, we may assure ourselves 
 that water existed in their neighbourhood also, previous 
 to eruption. 
 
THEORETICAL GEOLOGY. 85 
 
 It may also be remarked that volcanic activity in all 
 situations presents the same phenomena, modified by 
 local circumstances. Volcanos have been divided into 
 three classes: those that are in a state of permanent 
 eruption ; those whose activity is moderate ; and those 
 whose eruptions are violent, but characterized by pro- 
 longed intermittences. 
 
 The volcanos of permanent activity are few in 
 number, and are not known to produce any violent 
 consequences. Stromboli is one of this class, and has 
 been in a state of constant eruption, for more than two 
 thousand years. It seldom or ever throws its lava over 
 the crater, but incessantly ejects large masses of burning 
 rock and cinders. 
 
 Under the class of moderate activity, we may mention 
 the volcano of Popocateptl, in Mexico, which was found 
 in this phase by the discoverers of that country. 
 
 But the majority of volcanos belong to the third class, 
 and are characterised by unfrequent, but violent activity. 
 This, according to Baron Humboldt, is always the con- 
 dition of lofty cones, and arises in all probability from 
 the violent exertion that must be required to raise the 
 lava to the summit of the mountain ; and we conse- 
 quently observe that they usually eject their lava from 
 lateral openings. During the periods which intervene 
 
86 OUTLINE OF 
 
 between the eruptions, they are generally in a state of 
 perfect repose; but when they are excited to action, it 
 is most terrible. The dreadful eruption of Tomboro, in 
 the island of Sumbawa, is still in the recollection, and 
 its violence may be best estimated by the fact, that its 
 detonations were heard at a distance of nine hundred 
 and seventy miles. 
 
 But, although there are degrees of violence, and diffe- 
 rences in the periods of activity, yet there are certain 
 general phenomena which precede and accompany 
 eruption, proving that they arise from the same cause. 
 And if we examine the lavas which are ejected by 
 modern volcanos, and the igneous rocks which occur in 
 stratified deposits, we shall not doubt that they have 
 originated from the same agent. 
 
 Earthquake usually precedes volcanic eruption. What 
 the geological effects of earthquakes are, we cannot 
 easily determine, but, from the results that appear, it is 
 evident that they considerably disturb and disarrange 
 strata. This may, therefore, be one of those agents 
 which effected such violent changes during the depo- 
 sition of rocks. 
 
 Volcanic action has been attributed to a variety of 
 causes. Superstitious feelings have attributed them to 
 supernatural agents ; and there is every reason to believe 
 
THEORETICAL GEOLOGY. 87 
 
 that much of ancient fable and idolatry arose from the 
 personification of natural phenomena, particularly those 
 of a destructive character. But, to pass over all the 
 classical and oriental tales, we may enumerate a few 
 of the many hypotheses which have been maintained 
 by philosophers. 
 
 Lucretius, in his " De Rerum Natura," maintains that 
 volcanic eruptions are occasioned by the conversion of 
 the compressed air, which exists in the internal cavities 
 of the earth, into violent winds by heat; and that by 
 some most extraordinary and untold influence, the com- 
 bustible bodies existing in the mountains are inflamed. 
 The effect of this internal air he supposes to be much 
 increased by the passage of external winds through the 
 crater. We must, however absurd this hypothesis, 
 grant Lucretius the honour of correcting the Aristotlean 
 theory, that wind was an elementary substance born in 
 the earth; for he supposes an internal connexion be- 
 tween volcanos and the sea, and thus contrives to fill 
 his subterranean apparatus. 
 
 Werner and many of his school believed that volcanos 
 were produced by the ignition of coal and other inflamma- 
 ble substances; and to support this theory, Pallas attri- 
 butes the eruption of the mud volcanos, near the Cim- 
 merian Bosphorus, to the ignition of the coal measures. 
 
88 OUTLINE OF 
 
 Brieslak thought to improve this theory by ascribing 
 it to the ignition of petroleum collected in subterranean 
 caverns. To ignite his reservoirs of Petroleum, he sup- 
 poses the 'existence of sulphuric and phosphoric acid ; 
 and, in support of his theory, adduces the presence of 
 petroleum and the acids in lava. 
 
 Sir Humphrey Davy, following out his noble dis- 
 covery, that earths and alkalies have metallic bases, 
 deduced from it a theory of volcanic action. He sup- 
 poses the whole earth to have been originally a globe 
 of metallic alloy, endowed with such properties that 
 by a combination with the oxygen of the atmosphere, 
 a crust of earthy matter was formed extending, in com- 
 parison to the whole diameter, only to a small depth. 
 The nucleus of the globe he considered to be a deu- 
 oxydised metallic mass. Now, when water penetrates 
 through the crust of the globe, and finds its way to 
 the metallic mass, a chemical action immediately com- 
 mences. The water is decomposed by the great affinity 
 of the metal for oxygen, hydrogen gas is liberated in 
 large quantities, and, exerting all the force of a confined 
 elastic body, it rends asunder all obstacles, and bursts 
 into a flame upon meeting with the atmosphere. 
 
 There is certainly a degree of plausibility, and per- 
 haps of philosophy, about this singular theory. Admit 
 
THEORETICAL GEOLOGY. 09 
 
 the metallic nucleus and its inflammability, and it will 
 conduct you to all that is usually required, an explana- 
 tion of phenomena. But, unfortunately, this is more 
 than we can admit; and Sir Humphrey himself was 
 induced, a short time before his death, to renounce his 
 ingenious assumption, and to prefer an explanation 
 founded upon central heat. 
 
 But the theory has not been entirely renounced by 
 the scientific world; Dr. Daubeny has afforded it all 
 the assistance of his talents; but we believe there is 
 little prospect of establishing it in the face of the 
 unproved suppositions it requires. 
 
 We must first allow that the alloy of which the earth 
 is composed, is of a metallic nature. This, Dr. Daubeny 
 considers as very probable, but we imagine it almost 
 impossible. Little argument can be adduced on either 
 side; it is a mere inference, and the one party is as 
 much at liberty to infer as the other. 
 
 But, supposing that we allow this statement as true, 
 we are then told it is of such a nature, that by the 
 contact of water it becomes oxydized, liberates hydro- 
 gen, and absolutely takes fire. We may now find a 
 field for argument. The nature of the metallic nucleus 
 must necessarily be determined by the composition of 
 the earth's crust or of lava. Dr. Daubeny states that 
 
90 OUTLINE 0V 
 
 silica, alumina, lime, and iron, are the chief constituents 
 of volcanic products. The metallic nucleus, therefore, 
 is an alloy of silicon, aluminium, calcium, and iron. 
 But of all electro-positive substances, silicon is the 
 most incombustible ; it may be made white hot in the 
 open air without showing any tendency to burn. But 
 there is every reason to suppose that silicon is not a 
 metal, but that it bears a closer analogy to carbon, a 
 non-metallic substance; and so far from alloying with 
 aluminium, calcium, or iron, it evinces little tendency 
 to unite with any other body, except when it is in a 
 nascent state, or when double affinities are exerted. A 
 consideration of the properties of aluminium is equally 
 fatal to the 'theory. Water has little effect upon it, for 
 by long boiling, when in a state of fine powder, it sus- 
 tains no visible alteration. At a red heat it begins to 
 oxydize ; but we find by experiment, that its action on 
 water is much more feeble than that exerted by iron or 
 zinc. Of calcium and iron we need not speak; the one 
 is only an imaginary substance, and the properties of 
 the other are well known. 
 
 These are the chemical objections we have to Dr. 
 Daubeny's theory. We might adduce many of a phy- 
 sical character, such as the arrangement of the metallic 
 nucleus, the impossibility of water penetrating the super- 
 
THEORETICAL GEOLOGY. 91 
 
 ficial crust, and the improbability of any chemical 
 action being developed under so great a pressure; but 
 the remarks we have already made are, we think, fatal 
 to the theory. 
 
 Another hypothesis attributes eruption to central 
 heat. From a variety of experiments which have been 
 made, it seems certain that the temperature of the earth 
 increases downwards. This fact has been made the 
 basis of a theory; and it is supposed that the heat, in 
 its endeavour to escape upwards, fixes itself upon some 
 beds which are bad conductors, or non-conductors, of 
 caloric. Gases are generated by the fusion, the super- 
 posed rocks are upheaved, and the intumescent mass is 
 ejected through the opening. 
 
 The reader may now apply any of these explanations 
 of the volcanic cause to the ancient rocks. We cannot 
 pretend to direct his choice, for it appears to us one of 
 those questions which remain to be solved. 
 
 The most remarkable difference between the exertion 
 of the ancient and modern volcanic agent is, that, during 
 the action of the former, lava was ejected from fissures, 
 but in the present day from cones. 
 
 A volcanic mountain is necessarily a considerable 
 time forming. The results of a first eruption are the 
 upheaving of the strata, and the accumulation of a bed 
 
92 OUTLINE OF 
 
 of lava. By successive eruptions, the fissure which is 
 in the first instance formed, is in part closed, the scoriae 
 which are ejected accumulate round the orifice, and a 
 cone is formed. By the ejection of lava over this mound 
 of scoriae, it is both strengthened and enlarged. Should 
 the eruptions be frequent, the hillock is soon formed 
 into a hill, or even a mountain. This may be assisted 
 or retarded, by the structure of the country. Where 
 obstructions are presented, they increase from the accu- 
 mulation of scoriae and lava, and thus considerable 
 deviations in the form of the mountains will be produced ; 
 but they are usually conical, as might be expected. 
 
 The ancient volcanic rocks are the result of one 
 eruption; and, consequently, no cone could have been 
 formed. And if the fissures are larger than those 
 formed by modern activity, it must entirely result from 
 the greater violence of the volcanic cause. 
 
 This general comparison of the ancient and modern 
 volcanic rocks proves, we think, as well as the other 
 subjects to which we have referred, that the causes 
 now exerting their influence on the surface of the globe 
 were instrumental in forming the rocks which compose 
 the crust of the earth. 
 
 An argument in favor of the progressive and suc- 
 cessive formation of the fossiliferous rocks might also 
 
THEORETICAL GEOLOGY. 93 
 
 be drawn from the number and variety of organic 
 remains, which, like the relics of art, seem to point out 
 the character and circumstances of the age in which 
 they lived. There was a time when philosophers, as 
 well as the vulgar, attributed them to the Noahan 
 deluge, and recent attempts have been made to revive 
 the opinion. But, how ingenious soever the effort, it 
 must, ultimately, entirely fail, and has already failed 
 in the estimation of those who are able to judge of its 
 merits. 
 
 But we are compelled to acknowledge the presence 
 of the remains of organized creatures in the strata of 
 the globe, and we cannot rationally deny that they 
 existed under the same circumstances as their congeners 
 at the present moment, and that the beds in which they 
 are deposited were formed by causes that are still in action. 
 
 If the proposition which we have endeavoured to 
 illustrate be admitted, it will necessarily follow that 
 their formation occupied a considerable period of time, 
 and we shall not have much difficulty in proving that 
 it was antecedent to the universal deluge. 
 
 If in our examination we were to take only a general 
 view of strata as a numerous assemblage of beds, 
 formed by nearly the same causes, and without any 
 great revolutions, we should be compelled to admit that 
 
94 OUTLINE OF 
 
 their deposition must have occupied a very considerable 
 portion of time. If we watch the progressive formation 
 of strata in the beds of rivers, even under the most 
 favorable circumstances, we shall find that they are 
 slowly progressive, and considerable time must elapse 
 before they can be of any discernible thickness. The 
 formation, therefore, of the immense mass of strata 
 which compose the crust of our globe, must have re- 
 quired no ordinary space of time. 
 
 But it will be necessary to take a more extended view 
 of this question. We are not only to consider the crust 
 of the earth as composed of a mass of strata, but as a 
 series consisting of rocks of various characters, and 
 containing various animal remains. The same state of 
 things, as we have already seen, could not have pro- 
 duced all the beds which are found. Sometimes a dis- 
 trict has been under the sea, at other times it has been 
 dryland; sometimes it has been covered with a detritus 
 of rocks that was produced by the most violent causes, 
 and at other times it has been the locality of a mineral 
 spring. In whatever situation we examine rocks, we 
 find that various causes have contributed to their for- 
 mation; and we may trace in the character of the 
 beds the various changes which have passed over the 
 district in which they are now found. But it is not 
 
THEORETICAL GEOLOGY. 95 
 
 possible that all these alterations in the physical cha- 
 racter of a district could be accomplished without the 
 lapse of time. 
 
 A still farther proof of the antiquity of the fossilife- 
 rous beds may be gathered from the character of the 
 organic remains they contain. It is not uncommon to 
 find a series of beds containing the relics of fresh-water 
 animals, situated between those which are filled with 
 those that are decidedly marine. Now we know from 
 experiment and from observation that it is as impossible 
 for a marine animal to exist in fresh-water, as for terres- 
 trial animals to live in the sea: then, under such circum- 
 stances, a sufficient time must be allowed to admit of 
 the alteration of the physical causes which produced 
 one bed, and the establishment of those which produce 
 another; for the destruction or removal of one class of 
 animals, and the collection of another. 
 
 To illustrate our proposition that the deposition of 
 strata must have taken a considerable time, we will 
 endeavour to trace the progress of beds as now forming 
 in our lakes and rivers. 
 
 Wherever water is found, there, in all probability, 
 deposits are going on ; the extent and character of the 
 deposit evidently depends upon the locality. The first 
 
96 OUTLINE OF 
 
 question that arises from this statement is, how does 
 water obtain the substances it deposits ? 
 
 The substance of all the strata which water is instru- 
 mental in forming is derived from the destruction of 
 rocks. It is characteristic of this world, that all things 
 are passing away: the human body is continually 
 changing its form, and all the organized creatures 
 beneath him are either progressing or retrograding, 
 advancing to maturity, or falling to decay. Every thing 
 in the animal and vegetable worlds is continually pre- 
 senting itself in a new form, and what it was yesterday 
 it is not to-day. Finite in its existence, it is tending to 
 change. 
 
 The same remarks may be applied to the world on 
 which we tread, it is changing its appearance as we walk 
 over its surface. That which we are in the habit of 
 considering so firm and stable, so marked and un- 
 changeable, need experience the effects of but few of 
 those destructive agents which it bears in its own 
 bosom, and its entire surface would present a new and 
 novel appearance. How singular soever these remarks 
 may appear, they are easily proved; and the reader 
 need not, whatever may be the locality in which he is 
 situated, go far for examples. But we will enumerate 
 
THEORETICAL} GEOLOGY. 97 
 
 the causes which are most active in the destruction of 
 rocks. 
 
 We have already referred to the effects of the 
 atmosphere upon calcareous rocks. But all others are 
 in some degree affected by this apparently insignificant 
 cause, particularly those which have felspar as a con- 
 stituent. M. Daubuisson states that in a road-way cut 
 through granite, the rock was in six years entirely 
 decomposed to the depth of three inches ; and in 
 Auvergne and the Eastern Pyrenees, the effect has 
 been so great, that the traveller would rather imagine 
 himself in a bed of gravel than in a granite country. 
 
 Water is another, and the principal, cause of the 
 destruction of rocks. This agent approaches it in so 
 many ways, that we can scarcely estimate its effects, 
 except in the number and extent of its deposits. 
 
 Atmospheric water affects rocks in two ways, by 
 beating upon and running over their surface, and by 
 percolation through them. 
 
 The effects of atmospheric water upon the surface 
 in destroying it, and in accumulating the scattered frag- 
 ments of rock, is best seen in mountainous countries. 
 In passing through the vallies of all mountainous dis- 
 tricts, large heaps of detritus, brought down by the 
 torrents, may always be observed. Sometimes these 
 
 H 
 
98 OUTLINE OF 
 
 mounds are covered, and in some degree strengthened, 
 by vegetation ; but they are, notwithstanding, loose and 
 unsolid, and always liable to be destroyed by falling 
 waters. 
 
 During the passage of water from the surface of the 
 earth, through a series of beds, a considerable amount 
 of detritus is carried off, and in some instances a large 
 tract of country will be mechanically loosened. When 
 an accumulation of water has once formed for itself a 
 channel, it will necessarily carry to its egress the mineral 
 substances it takes up in its course, and deposit them in 
 the vallies through which it may run. 
 
 There is, also, another effect produced by the perco- 
 lation of water. Let us suppose the water from above 
 to pass through a series of porous rocks, and afterwards 
 to be stopped by an impervious clay; the water will 
 then take its course in the direction of the stratum, and 
 escape wherever it finds an opening. The argillaceous 
 stratum will, in consequence of the running water, 
 become moist and slippery, and should the strata be 
 situated at a high angle, the whole mass will stand in 
 danger of being unceremoniously cast into the valley 
 beneath. 
 
 This has actually happened at Rossberg, a mountain 
 in Switzerland, which rises to the height of five thou- 
 
THEORETICAL GEOLOGY. 99 
 
 sand one hundred and ninety-six feet. Its upper beds 
 are composed of the debris of the Alps, of a previous 
 geological epoch, resting upon a stratum of clay, dipping 
 at an angle of about 45. Through these upper beds 
 the water percolates to the clay beneath, and passing in 
 the direction of the stratum, discharges itself into 
 the valley below. On the 2d of September, 1806, 
 the clay being softened, and rendered slippery by the 
 action of the water, these beds were slidden from 
 their situation, and thrown into a beautiful valley be- 
 neath, destroying in its ruins the once picturesque 
 villages of Goldau and Busingen. 
 
 These are a few of the effects produced by atmospheric 
 causes, but it must be ever kept in mind that, although 
 we are compelled, in our endeavour to simplify science, 
 to examine causes in their individual character, yet 
 they are always combined in nature, and greatly modify 
 each other. There is, for instance, a reproduction 
 going on, as well as a destruction of land. The large 
 accumulations of detritus, that is, destroyed materials, 
 are not allowed to remain at the base of mountains or 
 cliffs where they fall, but are carried away, in many 
 instances, by the same agents as produced them. 
 
 A considerable quantity of debris is also collected by 
 the falling of glaciers and the melting of snows. The 
 
 H2 
 
100 OUTLINE OF 
 
 mountain torrents, of which we have already spoken, 
 are considerably augmented by the liquefaction of the 
 snows that surround the flanks of mountains. 
 
 Glaciers are large bodies of ice formed in lofty coun- 
 tries, above the line of congelation, which are cast down 
 into the valleys beneath, destroying in their passage 
 both vegetable and animal nature. They assist in the 
 degradation of land, by transporting all those loose 
 substances with which they come in contact. There are, 
 therefore, usually found at the front of glaciers heaps of 
 rock, earth, and trees, which have been driven before 
 them in their course. Sometimes they transport blocks 
 of large dimensions, which could not otherwise have 
 been forced into the valleys. When they pass over 
 precipices, carrying before them these heaps of detritus, 
 a large quantity of fragments is hurried into the ravines 
 beneath, causing, as we are informed by travellers, the 
 only deviation from the solemn silence of these wild but 
 sublime regions. 
 
 The velocity of the glaciers is comparatively small. 
 Mr. De la Beche has stated that a ladder left by 
 Saussure at the upper end of a glacier, has recently 
 been discovered in the Mer de Glasse, which is a con- 
 tinuation of the same glacier; it was left in 1787, and 
 it had advanced three leagues in forty-three years. But 
 
THEORETICAL GEOLOGY. 101 
 
 this rapid progress for a glacier ceased upon its arrival 
 at the Mer de Glasse ; and it has been observed that a 
 mass of rocks brought down the mountain by the same 
 glacier did not advance more than two hundred yards 
 in 1830. 
 
 These mounds of debris are gradually accumulated 
 and slowly conveyed to the valleys, where they are 
 swept away by the impetuous streams which result 
 from the melting of the glaciers. 
 
 All rivers, also, have some effect in altering the sur- 
 face of our earth, but the degree of change depends 
 upon their velocity. The velocity of all rivers is 
 always greatest in their centres, yet their beds and 
 sides are constantly exposed by friction to their des- 
 troying powers. When a current passes through a 
 hard and compact bed, it must have some considerable 
 velocity to disengage any quantity of the rock, though 
 rivers ever appear to be striving so to effect their 
 progress as to suffer the least resistance possible, 
 by cutting down obstacles, and filling up depressions. 
 But, notwithstanding all the efforts which they are con- 
 tinually making, the removal of one obstacle only pro- 
 duces others, by which their operations are continually 
 changed, but not lessened. 
 
102 OUTLINE OF 
 
 When earthy matter has been once united with running 
 water, it tends, by mechanical force, to undermine all 
 the rocks against which it is thrown. When this is 
 accomplished, a portion is precipitated into the stream, 
 a temporary increase of water is occasioned, and in 
 course of time, the barrier is destroyed. By a repetition 
 of these slips, sinuosities in the course of the river are 
 occasioned ; and the force of the stream is exerted, first 
 on one side and then on the other. 
 
 By the action of the sea on coasts, rocks also suffer 
 great degradation. The Shetland Isles, so peculiarly 
 exposed to the uncontroled violence of the fierce 
 Atlantic, will afford us excellent illustrations. "The 
 Isle of Stenness/' says Dr. Hibbert, "presents a scene 
 of unequalled desolation. In stormy winters, huge 
 blocks of stone are overturned, or are removed from 
 their native beds, and hurried up a slight acclivity, to a 
 distance almost incredible. In the winter of 1802, a 
 tabular shaped mass, eight feet two inches by seven 
 feet, and five feet thick, was dislodged from its bed, 
 and removed to a distance of eighty or ninety feet. I 
 measured the recent bed from which a block had been 
 carried away, in the winter of 1818, which was seven- 
 teen feet and a half, by seven feet; and the depth, two 
 
THEORETICAL GEOLOGY. 103 
 
 feet eight inches. The removed mass had been borne 
 to a distance of thirty feet, when it was shivered into 
 thirteen lesser fragments." 
 
 This is but one of the many instances which might 
 be adduced, of the violent action of the sea, upon the 
 coast of these interesting islands. At Navir, the sea 
 has forced a passage through rocks of hard porphyry; 
 and at Fitful Head, so well known as the resorting place 
 of one of Sir Walter Scott's heroes, the clay slate of which 
 it is composed is undergoing continued degradation. 
 
 The whole of the east coast of England is suffering 
 from the action of the sea, but no part more than the 
 Isle of Sheppey. We have seen many yards of the cliff, 
 which is composed of blue or London clay, plunged 
 into the sea. About twenty years since, the church of 
 Reculver was an hundred and fifty feet from the beach ; 
 but since that time, a part of the church-yard has been 
 washed away. The church at Minster is said to have 
 been in the middle of the island, fifty years ago, and is 
 now but a short distance from the coast; and it is 
 asserted that if the destruction continues at the same 
 rate, the whole island will be swept into the sea in about 
 fifty years more. 
 
 When a mass of water is accumulated by any means, 
 and the obstacles to its progress are suddenly removed, 
 
104 OUTLINE OF 
 
 the consequences are tremendous. In the year 1818, 
 masses of ice having fallen in the upper part of the 
 Vallee de Bagne, the course of the river Dranse was 
 stopped, and, by the accumulation of the waters, a lake 
 was formed, which was one hundred and thirty metres 
 mean breadth, from three thousand to four thousand 
 metres in length, and thirty-six in height, which was 
 a volume of water estimated at twenty-nine million 
 cubic metres. A third part of this was mechanically 
 let off by the inhabitants, but the remainder, impatient 
 of such slow and careful operations, broke away; and, 
 travelling at the rate of eleven metres in a second, 
 carried off every thing that opposed its progress, and 
 covered the valley with immense accumulations of gravel, 
 clay, and sand. 
 
 Floods are other causes of the degradation of rocks; 
 those which occurred in Aberdeenshire, on the 3d and 
 4th of August, 1829, afford us an excellent illustration 
 of the power of running water, in destroying rocks. 
 This flood extended over nearly six thousand square 
 miles, and its destruction of property and land was al- 
 most inconceivably great. The bridge over the Dee, at 
 Ballater, was swept away by the force of the stream, and 
 masses of rock, three hundred pounds in weight, were 
 driven up inclined planes, which rose six feet in eight or 
 

 THEORETICAL GEOLOGY. 105 
 
 ten yards; and a large stone of eight or nine tons weight 
 was driven one hundred yards from its former situation. 
 To us, who are unaccustomed to such violent causes, 
 these facts are peculiarly striking; but they would be 
 little surprising to those who have witnessed the hurri- 
 canes and whirlwinds of tropical climes. 
 
 From these general remarks, it will be evident that 
 the action of the atmosphere, the percolation of water, 
 the melting of snows and glaciers, the cutting power of 
 rivers, and other causes, are constantly tending to form 
 detritus, and together effect a considerable destruction 
 of land. Taken separately, they may appear of little 
 importance; but, when we combine them, and take 
 a just and extensive survey of all, we shall not fail 
 to perceive that important causes are still in action, 
 producing important changes in the surface of our 
 globe. 
 
 These are the causes which produce much of the mi- 
 neral substance that is deposited by water. If no other 
 argument could be adduced, the comparative slowness 
 with which they operate, would be sufficient to prove 
 that the formation of strata must have occupied a con- 
 siderable time. But as we have now supplied the 
 waters with the substance which they are to deposit, it 
 will not, perhaps, be inapplicable to our argument, to 
 
106 OUTLINE OF 
 
 inquire what is done with this very considerable quantity 
 of detritus, which is constantly carried into them. 
 
 The quantity of matter deposited by streams must 
 vary according to circumstances; a stream of great 
 velocity will carry off a larger quantity of debris than 
 one which meanders slowly along. It has been calcu- 
 lated, that a velocity of three inches in a second, at the 
 bottom of a river, will tear up fine clay ; a velocity of 
 twelve inches in a second, will sweep away fine gravel; 
 but three feet in a second, will carry off angular 
 fragments. 
 
 But the character of the course through which a 
 stream is passing, must also be considered in our esti- 
 mate of the time required to form a deposit. It 
 may be a rock easily destroyed by water or not, and 
 upon this, as well as the velocity of the stream, the 
 quantity of detritus will depend. And hence, it will 
 perhaps be generally found, that a slow stream flowing 
 through a bed of clay, will produce more detritus than 
 one much more rapid, passing through a limestone. 
 
 The transport of detritus is also influenced by the 
 inclination of the bed of the river, upon which the 
 velocity in some degree depends. But this chiefly 
 relates to the transport of pebbles and angular frag- 
 ments. Let us suppose that a river has so undermined 
 
THEORETICAL GEOLOGY. 107 
 
 its banks, as to cause a considerable portion to fall in: 
 much of this will in a short time be carried by the river 
 from its present situation, and the argillaceous particles 
 will be deposited in those places where the waters are 
 most quiet, and the transport of the angular fragments 
 and pebbles will depend upon the velocity of the stream. 
 
 These general rules may be applied to the formation 
 of all recent deposits, that depend upon the transport 
 of detritus, by water. It would be easy to refer to a 
 great variety of instances, in which these principles are 
 exemplified ; but the most striking are those very con- 
 siderable beds which are so frequently formed in lakes: 
 and at the same time, they admirably illustrate the 
 time required to form a deposit. 
 
 It is not uncommon for rivers to flow into a lake, in 
 which will be deposited, the greater portion of that de- 
 tritus which they carry down in their course. When 
 the lakes are large, a great length of time will be re- 
 quired to fill them up; but, if the lake be small, and the 
 velocity so great as to carry a considerable quantity of 
 detritus, it will be quickly accomplished. 
 
 This may be observed, by reference to the lakes 
 Constance, Geneva, and the smaller ones, which are 
 situated between them. The Rhine deposits its trans- 
 ported materials, in the lake Constance; the Rhone, in 
 
108 OUTLINE OF 
 
 the lake of Geneva; the Adda and the Lago, in Como; 
 the Ticino, in the Maggiore; and Zurich and Lucerne, 
 receive that which is collected by several smaller alpine 
 rivers. 
 
 The lake Como, according to recent authorities, is 
 nearly filled by the detritus of the Adda and Mera; 
 the former having divided the lake into two portions. 
 The smaller of these is so shallow, from the deposits of 
 the two rivers, that, on the eastern side, aquatic plants 
 are seen above the water, and the process of filling up 
 is going on very rapidly on the western side. 
 
 The upper end of the lake of Geneva, called the 
 Leman lake, affords us another instance of rapid depo- 
 sition. The Rhone flows into this lake, and deposits 
 the entire of its detritus; when it enters the lake, it is 
 turbid and muddy; when it flows out, it is clear. "If 
 we could obtain," says Mr. Lyell, "a section of the ac- 
 cumulation formed in the last eight centuries, we 
 should see a great series of strata, probably from six 
 to nine hundred feet thick and nearly two hundred 
 miles in length." 
 
 Now, supposing the superficial crust of the earth 
 with which we are acquainted to be composed of a 
 series of beds but little differing from each other, and 
 presenting no remarkable phenomena, we must allow 
 
THEORETICAL GEOLOGY. 109 
 
 that their formation occupied a very considerable portion 
 of time. 
 
 But the crust of the earth, as we have already stated, 
 consists of a number of beds of various substances, irre- 
 gularly alternating with each other. It has been proved 
 by analogy, that these beds were formed by causes still 
 in action, in a manner similar to those that are now 
 being deposited in the beds of rivers and lakes, and 
 that the formation of each stratum requires a con- 
 siderable portion of time. But, if it require a length 
 of time to form a single deposit, how much greater time 
 will be necessary to form a series, each differing from 
 the other in mineralogical characters ? Circumstances 
 which will produce a calcareous deposit, will not pro- 
 duce an argillaceous. An entire revolution of local 
 circumstances is absolutely necessary, in order to 
 change the character of the bed. Admitting, therefore, 
 that the strata composing the crust of our globe were 
 formed with a rapidity of which we have no conception, 
 from a variety of circumstances, particularly the greater 
 surface temperature of our earth, of which we shall 
 presently speak, it is quite apparent that they required 
 considerable time for their deposition. 
 
 But all these beds are crowded with organic remains, 
 and each has those peculiar to itself. In certain beds 
 
1 10 OUTLINE OF 
 
 we find the remains of animals which cannot elsewhere 
 be found through the whole series, but seem only to 
 have existed at that particular time when these beds 
 were forming. Certain other beds contain, some in 
 great abundance, the remains of oviparous animals; but 
 neither above nor below them can an individual speci- 
 men be found. And there are other strata, and these 
 among the highest in the series, which contain the bones 
 of mammalia, but below them they have been sought 
 for in vain. Every step, therefore, that we take in the 
 investigation, impresses us the more deeply with the 
 conviction that time must have long shaken its hasty 
 wing over this terrestrial globe, and that the earth often 
 completed its accustomed journey round the great orb 
 of day after its creation, before the Eternal God of all 
 placed man upon it, as the perfection of his work, and 
 the object of his love. 
 
 But, if we would look still further into this question, 
 we must examine the relative position of rocks towards 
 each other. The natural position of all sediments would, 
 of course, be horizontal, or nearly so. But when we 
 come to the investigation of rocks as they are, we find 
 that they have been subjected to the most violent dis- 
 turbances. Here we find a series tilted by the action 
 of subterranean fires, and upon it horizontal undisturbed 
 
THEORETICAL GEOLOGY. Ill 
 
 strata. In another place we find the primitive rocks 
 thrust through a number of those that contain organic 
 remains, forming chains of snow-capt mountains; and 
 upon their flanks we trace a series of calcareous beds 
 in their undisturbed position. What more sufficient 
 proof that time was necessary for the formation of these 
 beds can be required or given ? Geologists have been 
 charged with presumption in their deductions, but what 
 can be clearer than the deductions they form from such 
 phenomena as the above. Here are a series of rocks 
 upheaved by ancient volcanic action, and others resting 
 upon them undisturbed; surely it requires little argu- 
 ment to prove that the horizontal beds could not have 
 been formed when the others were upheaved, that an 
 entirely new state of things must have been instituted 
 before they could have been deposited, and, consequently, 
 that a considerable time must have transpired between 
 the elevation of the one series, and the formation of 
 the other. 
 
 It is not requisite for the proof of our proposition to 
 enumerate all the phenomena presented by rocks. 
 Wherever we examine them, we observe the combined 
 action of water and fire ; and that the several localities 
 have at one time been beneath, at another above, the 
 waters. Sometimes we trace the action of subterranean 
 
112 OUTLINE OF 
 
 fires without any visible proof, except the disturbance 
 the rocks have suffered; and at other times we find the 
 fissures through which the liquified rock has been cast, 
 as well as the bed that was poured over the surface. 
 Above these, we may observe the horizontal strata, and, 
 perhaps, the entire series may have been afterwards 
 exposed to diluvian action, and portions of it swept 
 away by the force of an inconceivably violent flood. 
 
 Connect with these circumstances the fact that all 
 the deposits have been formed under different circum- 
 stances, and the demonstration of our proposition will 
 be tolerably complete. 
 
 The circumstances under which a bed was formed 
 must be determined by its mineralogical composition, 
 and the organic remains it contains : if it consist of 
 rounded pebbles and angular flints, we know that it 
 must have been formed under far more violent circum- 
 stances than if it consisted of clay or sand. If the 
 stratum contain remains of animals which are knownto 
 live in seas, we say that it is a marine deposit; if its 
 remains are fresh water, we call the deposit lacustrine, 
 or fresh water; and if they should be terrestrial, we 
 must judge of its origin either from the mineralogical 
 character of the bed, or the fossils which may be asso- 
 ciated with it, for it is possible that terrestrial animals 
 
THEORETICAL GEOLOGY. 113 
 
 may be washed into the sea, although it is far more 
 probable that they will find their graves in the bed of an 
 inland lake or river. 
 
 But how are we to account for the alternation of ter- 
 restrial and marine beds unless we allow that a con- 
 siderable portion of time was occupied in their deposi- 
 tion ? Let us suppose that in the beds of our rivers and 
 lakes depositions are going on, and that the remains 
 of fresh water animals are deposited in them ; before it 
 be possible that the entire deposition can be changed 
 and marine animals entombed, it will be necessary 
 that the sea should be let in upon the entire dis- 
 trict, either by the depression of the district itself or 
 the elevation of the present bed of the ocean. These, 
 however, are phenomena which are continually observed 
 by Geologists, and, consequently, the same circum- 
 stances must have interfered to produce them. 
 
 The formation of strata, therefore, must have required a 
 considerable time, and it is equally certain that they were 
 deposited at a period antecedent to the universal deluge. 
 The person who has taken the slightest notice of 
 geological phenomena, cannot have failed to observe 
 that immediately beneath the vegetable soil, in almost 
 all places, there are beds of gravel, sand, or clay, 
 with rounded pebbles. These beds are composed of 
 
 i 
 
114 OUTLINE OF 
 
 the detritus, or destroyed materials of older rocks, 
 called by Geologists diluvium; and are, in all pro- 
 bability, the result of the universal deluge. No fact 
 in Geology, therefore, is more certain than that, after 
 all the strata which compose the crust of our globe had 
 been formed, the entire earth was overwhelmed with an 
 universal flood. Where the water necessary to deluge 
 the world could be obtained by natural causes, is, per- 
 haps, difficult to conceive ; or what became of it when 
 obtained; "but it is less extraordinary," says Mr. 
 Greenough, "that water should have stood in some 
 former period at a height exceeding that of our highest 
 mountains, than that strata should have been formed 
 without a precipitate, that gravel should have been 
 rounded without attrition," or valleys excavated without 
 a flood. 
 
 There have, however, been some who have rejected 
 the Scriptures on the ground that they will believe 
 nothing that they cannot understand. Nature, say 
 they, is our preceptress; but how often has she failed 
 to answer their interrogations, and when she has spoken, 
 how often has she given the lie to their principles. But 
 this is not the only instance in which natural phenomena 
 have corroborated the sacred records, and left the pre- 
 tended admirers of nature as much in ignorance of 
 
THEORETICAL GEOLOGY. 11/3 
 
 causes as they were before they consulted her oracle. 
 Such men, to be consistent with their own assertions, 
 must have formed an enormous estimate of their mental 
 powers, rejecting, as unworthy their belief, one-half 
 of those beautiful truths which the investigations of 
 philosophy have discovered, but for which it cannot 
 account. 
 
 So great was the effect which the diluvian waters 
 had upon rocks, that in the midland counties of England 
 a complete suite of English specimens may be collected 
 from the gravel. And not only have gravels been trans- 
 ported, but also huge blocks, which could have only 
 been removed by an enormous rush of water. Near 
 Hayton castle there is a spheroidal mass of granite .ten 
 feet six inches in diameter, and more than four feet 
 high. At High Peak, in Derbyshire, there is a rolled 
 mass twenty-one feet high and nine feet wide. In some 
 places these transported masses are still larger, and so 
 numerous that they may be traced to the places from 
 which they were broken. The same facts have been 
 observed in every other investigated portion of the 
 world; and the current seems to have taken a direction 
 from N.E. to s.w. 
 
 Much has been written concerning the state of the 
 earth previous to the deluge, or, in other words, upon 
 
 i2 
 
116 OUTLINE OF 
 
 the effect which the waters had in causing the present 
 superficial appearance of the earth. Some persons 
 have maintained that, before the deluge, the world was 
 a plane, and that all the variations of mountain and 
 valley which we now observe, was occasioned by the 
 action of the waters. Such an opinion, however, is 
 the height of absurdity, for, if the earth had no depres- 
 sion before the deluge, it could have had no sea, and, 
 therefore, must have been a vast, sterile, and uninha- 
 bited, desert. Some of the largest and deepest of our 
 valleys were formed previous to the deluge, by the eleva- 
 tion of strata; but, at the same time, it must be remem- 
 bered, that the deluge did much to give the pleasing 
 form of elevation and depression to our globe, by sweep- 
 ing over the surface and excavating valleys. 
 
 If, therefore, the beds of gravel which cover over all 
 the strata were formed by the diluvian waters, and also 
 the valleys which are cut out of the strata themselves; 
 then the whole of the fossiliferous rocks were formed 
 previous to the universal deluge. The period which 
 intervened between the creation of man and the deluge 
 is, evidently, insufficient to have accomplished their 
 deposition; they must, therefore, have been formed pre- 
 vious to the creation of the human species. 
 
 To complete our examination of the deduction that a 
 
THEORETICAL GEOLOGY. 117 
 
 considerable time was required for the deposition of 
 the beds composing the crust of our globe, it will be 
 necessary to consider that our earth experienced a 
 greater surface temperature during the deposition of 
 the beds, and that it has gradually decreased. This is 
 a question of great importance, for it is evident that 
 the higher the temperature, the greater the evaporation, 
 and the power of meteoric agents, the more violent will 
 be the storms, and the larger the quantity of detritus ; 
 consequently, deposits will be more rapidly formed in 
 tropical than in temperate climes. And the same cause 
 would powerfully influence the growth and increase of 
 vegetable and animal life ; hence, we find that both the 
 land and waters are most crowded with organized crea- 
 tures in the hottest portions of our globe. 
 
 The formation of strata would, consequently, be accom- 
 plished in the early ages of the world with little diffi- 
 culty, for the torrents of water which would be pro- 
 duced under such a state of things, would be more 
 violent and sudden than the inhabitants of tropical 
 districts could at the present time possibly conceive; 
 and the quantity of detritus formed would be propor- 
 tionally greater than that which is now produced. 
 
 But, in addition to this, we must remember that there 
 is no reason to suppose that subterranean forces were 
 
118 OUTLINE OF 
 
 less active at this period than they have since been, but, 
 on the contrary, more violent and frequent, as we not 
 only find igneous rocks intermixed with the deposits, 
 but that they have suffered the most terrible con- 
 vulsions. Great changes have also been produced by 
 altering the level of land and water, and in upheaving 
 mountain chains. 
 
 On the other hand, it may be objected, that in pro- 
 portion to the increase of temperature, there will be an 
 increase of vegetable life. But, as degradation of land 
 is considerably prevented by vegetation, which binds 
 and solidifies the loosest soils, so the effects of violent 
 fains would be much less than we may at first suppose. 
 This we are quite willing to concede, but at the same 
 time feel no difficulty in asserting that the degrada- 
 tion of land in tropical climes, in spite of the antagonist 
 power which vegetation exerts, is much greater than 
 that which generally occurs in colder regions. 
 
 The great vigour of vegetation in tropical clinoes 
 can hardly be imagined by the inhabitants of this 
 portion of the globe. The idea of a forest from any 
 thing that may be seen in Europe is very insufficient 
 to paint the luxuriant vegetation of the tropics; nor 
 could our coal deposits have been supplied from such 
 Scanty sources. We would rather refer to the vast 
 
THEORETICAL GEOLOGY. 119 
 
 forests of Brazil or Guiana, almost too thickly en- 
 twined to admit of human research, and to the luxuriant 
 and extensive woods on the banks of the Missouri. If 
 we can imagine the immense quantities of vegetable 
 matter which is there produced all the year round, and 
 year after year for ages, we may perhaps approach to 
 the state of our northern climes when our coal beds 
 were formed. Every thing connected with the coal 
 deposits was tropical. Such was the climate that pro- 
 duced, the forests that bore, and the rivers that trans- 
 ported into their estuaries, the vegetables which were 
 designed by the Creator to become, in future ages, 
 the source of comfort and wealth to his creatures ! 
 
 Nor is this a merely hypothetical case. In the 
 tropical lakes and estuaries of the present day, the 
 same phenomena may still be seen. The Mississippi, 
 " after the flood season," says Mr. Lyell, when the 
 river subsides within its channel, acts with destructive 
 force upon the alluvial banks, softened and diluted 
 by the recent overflow. Several acres at a time, 
 thickly covered by wood, are precipitated into the 
 stream," and sometimes large islands are swept away. 
 Mr. Darby informs us that a large quantity of drift 
 wood is brought into the Atchafalaya, an arm of the 
 Mississippi, and being there arrested, forms a .raft, 
 
120 OUTLINE OF 
 
 which in 1816 was ten miles in length, two hundred 
 and twenty yards wide, and eight feet deep. And in 
 addition to this accumulation of drift wood and other 
 products of degradation which are united to it, forming 
 an island, a large quantity of detritus is annually car- 
 ried into the Gulf of Mexico. 
 
 Another argument in favor of greater surface tempera- 
 ture may be drawn from the abundance and size of organic 
 remains. The naturalist as well as the botanist seeks 
 the tropics to study, in all their varieties, the objects of 
 his attention. It is not in our chilly seas that we 
 expect to find the coral reef and the swarming testacea, 
 it is not by the banks of our lakes and rivers we study 
 the habits of the saurians and crocodiles; we must pass 
 into more congenial situations, and watch the banks of 
 the Nile, or sail over the broad surface of the Pacific. 
 Yet beneath our feet, we have enormous accumulations 
 of animal remains in the limestones and other rocks, 
 vvhich could only have been produced in an equatorial 
 temperature. 
 
 But a still greater proof that the temperature of 
 our planet has diminished is found in the character of 
 the vegetable remains that are imbedded in strata. 
 In the rocks associated with our coal beds we do not 
 find the plants which now inhabit our shores, but 
 
THEORETICAL GEOLOGY. 121 
 
 arborescent ferns and other vegetables, which require 
 a climate at least as warm as the tropics. But these 
 plants increase in size in proportion to the height of 
 the temperature; and as those which are found in the 
 coal measures are larger than any that we find in the 
 hottest regions of the present day, we may fairly con- 
 clude that there was a higher temperature, even in these 
 northern latitudes, during the formation of the coal 
 measures, than can now be found on the surface of the 
 globe. 
 
 If observation be extended to the organic remains, 
 we shall be impressed with the same fact. In certain 
 strata of our own country the remains of oviparous 
 quadrupeds are found, the whole class being now con- 
 fined to the higher temperatures. But the animals 
 to whom these remains belonged were of a gigantic 
 size, and were, perhaps, the lords of the creation. 
 The fabled monsters of antiquity which have so often 
 delighted and amazed our childhood, become sober 
 truths when compared with the discoveries of geolo- 
 gists in this department of our science. Some of these 
 reptiles are only found in marine deposits; some were 
 terrestrial, and others inhabited the lakes and rivers. 
 But they all required and enjoyed a temperature 
 
122 OUTLINE OF 
 
 much higher than that which is now experienced in our 
 northern latitudes. 
 
 In one deposit we meet with the remains of a 
 monstrous terrestrial animal, at least thirty or forty feet 
 in length, and from seven to eight in height. In another 
 series of beds we find the bones of the iguanodon, a 
 creature excelling in magnitude the megalosaurus him- 
 self. The ichthyosauri, crocodiles, and turtles, are also 
 to be found enclosed in the solid strata of the globe. 
 
 Wherever we turn we find the remains of organized 
 creatures, not only in such abundance as to assure us 
 that they existed under the most favorable circumstances, 
 but of such characters as to convince us that they lived 
 in a tropical climate. It would, therefore, appear that 
 at the time when the solid strata of the globe were 
 deposited, the temperature was much higher and more 
 equable than it is now. 
 
 The superficial temperature of the earth is now con- 
 siderably influenced by solar heat and the change of th,e 
 seasons ; but, at the same time, the temperature, as is well 
 known, decreases as we pass from the tropics to the poles. 
 But this has not always been the case, or, at least, the 
 temperature has been far more equable than it is in the 
 present day. 
 
THEORETICAL (GEOLOGY. 123 
 
 It may not be immediately connected with our 
 design to inquire into the cause of this change, and it 
 would be improper to enter at large into the question. 
 But we may, perhaps, be permitted, without much 
 impropriety, to refer to the theories which in the present 
 day engage the attention of geologists, although neither 
 are, we fear, sufficiently illustrated to enable us to 
 decide upon the truth with certainty. 
 
 It has been supposed by some geologists that the 
 greater surface temperature of the earth, during the 
 deposition of strata, arose from the greater internal 
 heat of the globe. 
 
 To establish this theory, we must first prove that the 
 temperature increases as we descend towards the centre 
 of the earth. Observations have, in consequence, been 
 made in some of the deepest mines; but all the methods 
 of determining the question which have been invented 
 are subject to so many errors, that we can hardly esti- 
 mate from the results. If we take the temperature 
 of the air, we must admit into our calculation the heat 
 that is generated from the lights, the blasting of rocks 
 by gunpowder, and the breath of the miners. And on 
 the other hand it is certain, that there must be a con- 
 tinual rushing of the heated air up the shafts, and the 
 pressure of the cold air downward*. 
 
124 OUTLINE OF 
 
 If we form our judgment from the springs which are 
 found in the mines, we must remember that their tem- 
 perature may be greatly changed by passing through a 
 series of rocks, many of them of a composition, per- 
 haps, tending to increase their heat. 
 
 If the temperature of stagnant waters or the rocks 
 themselves be taken, the observations will be open to 
 the same errors as influence the observations upon 
 the air. 
 
 But, notwithstanding all the errors to which the 
 experiments that have been made are exposed, it seems 
 to be almost certain that the temperature of the earth 
 increases considerably as we descend. Upon this 
 assumed fact, some geologists have endeavoured to 
 account for volcanic eruption and thermal springs. 
 They suppose that the caloric, in its endeavour to escape 
 upwards, fixes itself upon some beds which are bad 
 conductors or non-conductors, and by fusion produce 
 so large a volume of gases, as to thrust up the super- 
 posed strata, and form a vent for the intumescent mass, 
 or to heat so intensely the rocks, as to boil the springs 
 which rise in their neighbourhood. 
 
 There are only two arguments that we could use, 
 were we called upon to support this theory of the 
 decrease of interior heat. 
 
THEORETICAL GEOLOGY. 125 
 
 Whatever class of rocks we examine, the action of 
 
 volcanic agents upon them is most evident. This con- 
 es Jr 
 
 stant activity of the volcanic agent may possibly have 
 arisen from the great internal heat of the earth; and it 
 is quite certain that the superficial temperature must 
 have been influenced, if such a state of the interior 
 existed. 
 
 But the strong argument in favor of this supposition 
 is, that thermal springs must have been much more 
 numerous than at present; and we may thus account 
 for the abundance of siliceous deposits. It would also 
 follow from the admission of the theory, that their influ- 
 ence would be more evident in proportion to the age 
 of the rock, and this seems to be the result of our 
 examinations. 
 
 Sir W. Herschel has calculated that the decreased 
 temperature of the earth may be accounted for by the 
 fact that its orbit has been for ages becoming less ellip- 
 tical, and, consequently, the minor axis increasing. 
 Now, if it can be supposed that the earth's orbit was 
 very elliptic, at the time of the deposition of strata, that 
 would probably be sufficient to account for the greater 
 surface temperature ; but such a supposition necessarily 
 implies, that they were formed at an almost incon- 
 ceivably distant period of time. 
 
OUTLINE OF 
 
 Mr. Lyell explains the difference of temperature 
 upon another principle: he considers it to depend 
 upon the relative proportions of land and water near or 
 at the poles. The higher the polar land, the greater 
 would be the cold; but in proportion to the quantity of 
 land at or near the equator, would be the quantity of 
 water at the poles. When, therefore, the sea abounds 
 at the poles, the temperature of the earth will be higher 
 than when high land is present; and the more equably 
 will that temperature be diffused. As a proof of this, 
 he states that arborescent ferns are found in Van 
 Diemen's land, in 42 south latitude, which is a much 
 higher latitude than they reach in the northern hemis- 
 phere, where the climate is not so equable. And it may 
 be generally stated, that there is more and higher land 
 towards the north than the south pole. Mr. Lyell's 
 theory will therefore resolve itself into the following 
 statement. That the superficies of the earth has been, 
 and still is, constantly changing by the agency of rivers, 
 currents, earthquakes, and volcanos; and that this al- 
 teration of its position, relative to the equator and poles, 
 is amply sufficient to account for any difference of tem- 
 perature that may be required to explain the existence 
 of tropical plants and animals, under any latitude. 
 
 We have thus endeavoured to give a view of the de- 
 
THEORETICAL GEOLOGY. 127 
 
 ductions which we think may be drawn from an exami- 
 nation of geological phenomena ; and we may now, 
 perhaps, be permitted to take a hasty glance at the 
 formation of the world. 
 
 The earth has not existed for ever. " So far as the 
 causes now in action go, so far as our calculations will 
 enable us to estimate their effects, we are equally unable 
 to perceive in the general phenomena of the planetary 
 system either the evidence of a beginning or the prospect 
 of an end. But neither the researches of the physical 
 astronomer nor those of the geologist give us any ground 
 for regarding our system, or the globe we inhabit, as 
 of eternal duration; on the contrary, there are circum- 
 stances in the physical constitution of our own planet, 
 which, at least, obscurely point to an origin and a for- 
 mation, however remote; since it has been found that 
 the figure of the earth is not globular, but elliptical; 
 and that its attraction is such as requires us to admit 
 the interior to be more dense than the exterior, and the 
 density to increase with some degree of regularity from 
 the surface towards the centre. And that in layers ar- 
 ranged elliptically round the centre, circumstances which 
 could scarcely happen without some such successive 
 deposition of materials as would enable pressure to be 
 propagated with a certain degree of freedom from one 
 
128 OUTLINE OF 
 
 part of the mass to another, even if we should hesitate 
 to admit a state of primitive fluidity." (Herschel's 
 Disc, on Study of Nat. Hist. p. 281.) 
 
 That which is eternal in its duration must have the 
 property of unchangeableness. But this is not charac- 
 teristic of the earth ; it is continually changing its form, 
 not only in its superficies, but also in its chemical com- 
 position. That which is to-day floating through the 
 atmosphere, may to-morrow become a component part 
 of a solid rock ; and that which constitutes, this hour, 
 the summit of a mountain, may in the next find a 
 place in the deposits which are forming in the bed of 
 the sea. 
 
 The earth, then, was created at some period, and this 
 we deduce from science, independent of revelation. At 
 the period when it came from the hands of its Creator, 
 neither vegetables nor animals probably existed on its 
 surface. We may therefore consider it as a barren mass 
 of mountains and uninhabited waters. 
 
 Whether the non-fossiliferous rocks constituted 
 part of this primitive world, we are not able posi- 
 tively to determine. When we consider their 
 general chemical appearance, it may at least be as 
 probable that they were formed by the intervention of 
 secondary causes, as to suppose that they originated 
 
THEORETICAL GEOLOGY. 129 
 
 from the immediate hand of God. But, however this 
 may be, it can certainly be proved, that since their 
 creation they have been greatly disturbed and dis- 
 arranged by the influence of both igneous and aqueous 
 agents. 
 
 But, from the beginning the same causes and effects 
 have existed. Matter was created with certain laws, 
 which are universal; as soon, therefore, as the present 
 state of natural things commenced, the results which we 
 now observe, followed. Rocks were destroyed by the 
 action of the atmosphere and water; detritus was col- 
 lected, and strata formed by deposition. All the causes, 
 indeed, which now influence the destruction and forma- 
 tion of rocks, were in action, and by these causes, the 
 fossiliferous strata were formed. 
 
 These reciprocal causes and effects must have been 
 long in existence before the construction of the crust of 
 our planet could have been completed, although strata 
 were, in all probability, formed much more rapidly than 
 at present, in consequence of the higher surface tem- 
 perature. But after the whole was completed, an uni- 
 versal deluge spread its devastating effects upon the 
 earth, and strewed it with the relics of its violent 
 action. 
 
 These are the facts which we are taught by, and the 
 
 K 
 
130 THEORETICAL GEOLOGY. 
 
 opinions we form from, science, independent of the assis- 
 tance of that revelation with which it has pleased the 
 Almighty to bless us. To cast from us this volume, 
 whenever it offers us its assistance, is the most perfect 
 madness; but if we carefully examine its assertions, 
 and these opinions, and compare them together, we are 
 at least in the road to truth; and there is some pro- 
 bability that we shall succeed in finding it. This will 
 be the object of the succeeding chapter. 
 
 But, although we are about to enter upon the subject, 
 we are quite aware of the difficulties which surround 
 our path, and the impossibility of making our chain so 
 perfect that a link will not sometimes be found necessary 
 to complete the otherwise imperfect reasoning. In 
 conducting this investigation, we have carefully ex- 
 amined the Scriptures themselves, that we might not 
 misinterpret them ; and we have overturned no geolo- 
 gical truth, in order to combine the two statements. 
 
131 
 
 COMPARISON OF THE MOSA1CAL AND 
 MINERAL GEOLOGIES. 
 
 How valuable soever the deductions of science may 
 be, they cannot be regarded by a truly Christian mind 
 as of equal authority with the direct testimony of God. 
 There is a possibility, under all circumstances, that our 
 opinions may be false, however improbable it may 
 appear. The premises from which we argue may be 
 erroneous, or, if true, may be the exceptions to a 
 general rule, and not the law itself; or if the pre- 
 mises be perfect, the deductions may be illegitimate, 
 either from an imperfect view of the facts, or the want 
 of some other fact which is necessary for the argument. 
 
 While imperfection thus necessarily attaches itself to 
 all human speculations, the word of God is necessarily 
 true. Nor can human intellect and veracity compare 
 itself with the perfect knowledge, power, and purity of 
 the Almighty. 
 
 If, therefore, we admit that the Bible is divinely 
 inspired, we cannot with propriety either doubt the ex- 
 pediency of comparing scientific opinions and the testi- 
 mony of God, or prefer our deductions to the explicit 
 
 K 2 
 
132 COMPARISON OF THE 
 
 statements of Scripture. But we must rather experience 
 a pleasing satisfaction in having a common test by which 
 to estimate the value of accumulating knowledge; for, 
 when we examine the sacred word of God for a history 
 of the creation of the world, we come to the Creator for 
 information concerning his own work, and the process 
 by which he exerted his infinite power. 
 
 It is, then, important that all our opinions be compared 
 with the infallible statements of the word of God. We 
 may advance by the direction of nature to the highest 
 probabilities; but, if they are contradicted by scriptural 
 statements, they are necessarily false. A geological 
 truth cannot be contradicted by a divine assertion, for 
 truth is necessarily incontrovertible. Whether, there- 
 fore, we gather our facts from nature or the sacred tes- 
 timony, they are the same; and, if we are agreed in 
 receiving the Bible as divine in its origin, the error, 
 provided there be a contradiction, must be on the side 
 of scientific opinion, which is only worthy universaj 
 acceptation as a positive certainty when it coincides 
 with the divine testimony. 
 
 But, while we would ever insist upon the necessity of 
 comparing our theories of the earth with the statements 
 of revelation, \ve would as strenuously oppose the 
 false zeal of those persons who, in order to reconcile the 
 
MOSAICAL AND MINERAL GEOLOGIES. 133 
 
 two, are not slow to deny the most established facts, and 
 to overturn with a random stroke all that patient inves- 
 tigation and persevering genius has discovered. If the 
 divine assertions can only be supported by such means, 
 they can never be established at all. It is useless, 
 therefore, to deny what has been legitimately proved ; 
 and we pity the weakness of the mind that stoops to 
 evasion and fear. 
 
 The history which Moses has given us of the creation 
 of the world, and its state till the commencement of the 
 days, is evidently a mere outline. The great object of 
 the Divine Spirit under whose guidance he wrote, was to 
 detail the history of man, his character, condition, and 
 prospects. He has, notwithstanding, furnished us with 
 a few general facts, which are rather to direct our in- 
 quiries than to suspend them. Of those particular sub- 
 jects on which he has not treated, we are at perfect 
 liberty to form our own opinions. A theory of the for- 
 mation of the earth ought therefore to be only a detailed 
 description of the Mosaical history, a finished picture 
 from the outline sketch which the Jewish legislator has 
 given us. 
 
 The first chapter of Genesis, which contains all that 
 God has revealed concerning the creation, may be 
 divided into three periods: first, there is a statement 
 
134 COMPARISON OF THE 
 
 that the heavens and earth were formed by God. There 
 is then a description of the earth previous to the days 
 of creation, and afterwards a somewhat detailed account 
 of the order in which the Almighty furnished the world 
 during the six days. 
 
 All the sacred writers insist upon the creation of the 
 universe by God; he is the great universal cause from 
 which all things proceeded. Philosophy has discovered 
 that it was the work of an intelligent being; but it is 
 revelation alone that can teach his character and attri- 
 butes. "I am the Lord, that maketh all things; that 
 stretchetli forth the heavens alone; that spreadeth abroad 
 the earth by myself." (Isaiah, xliv. 24.) "Let all the 
 inhabitants of the world stand in awe of him; for he 
 spake, and it was done; he commanded, and it stood 
 fast.' 7 (Psalm xxxiii. 8, 9.) The prophet Isaiah, 
 when foretelling (xl. 12, 13,) the future glory of 
 Christ's kingdom, in a most beautiful manner refers to 
 the creative power of God, "who hath measured the. 
 waters in the hollow of his hand, and meted out heaven 
 with the span, and comprehended the dust of the earth 
 in a measure, and weighed the mountains in scales, and 
 the hills in a balance ! who hath directed the spirit of 
 the Lord, or being his counsellor hath taught him?' 7 
 And Moses also commences his history of the Creation 
 
MOSAICAL AND MINERAL GEOLOGIES, 135 
 
 by the statement, "in the beginning God created the 
 heavens and the earth." 
 
 This statement appears to be entirely distinct from 
 all that follows. The object which Moses had in view 
 seems to have been comparative; and the whole stress 
 of the sentence rests upon the word God. The Israelites 
 had seen idolatry in all its forms, and had frequently 
 fallen into the practice; but it was not the idols they 
 had seen or served, that created the heavens and the 
 earth, but God. 
 
 We are much inclined to suppose that there is in this 
 verse an indirect reference to the worship of the heavenly 
 host, and there is certainly a very explicit statement 
 that they are creatures, and not creators. The worship 
 of the heavenly host was the earliest species of 
 idolatry that was practised. In the book of Job, pro- 
 bably the oldest writing extant, and certainly composed 
 at an early period, we find a reference to the practice* 
 Job, in his reply to Bildad, the Shuhite, in a protestation 
 of integrity, says, "If I beheld the sun when it shined, 
 or the moon walking in brightness; and my heart hath 
 been secretly enticed, or my mouth hath kissed my 
 hand ; this also were an iniquity to be punished by the 
 judge: for I should have denied the God that is above." 
 (Job, xxxi. 26, 28.) 
 
136 COMPARISON OF THE 
 
 The Israelites, therefore, to whom the book of Genesis 
 was immediately addressed, must have felt the force of 
 the statement that "in the beginning GOD created the 
 heavens and the earth," whether they had joined in this 
 particular species of idolatry, or had only been the 
 witnesses of the practice. In what view soever we con- 
 sider this statement, whether as a simple assertion that 
 it was God, in contradiction to idols, who made the 
 heavens, as well as the body on which we live; or 
 whether we consider it applied to them as those who 
 had worshipped the heavenly bodies, and the things of 
 earth, the statement was all important and interesting. 
 
 That the worship of the planetary bodies should have 
 
 been the earliest species of idolatry, is, we think, more 
 
 than probable. Their great glory and utility, and the 
 
 sublimity of the knowledge which was early acquired, 
 
 concerning their nature and revolutions, might in a 
 
 great degree induce an unholy reverence. But another 
 
 reason may be given for the practice ; whenever the 
 
 Almighty showed himself to men, it was always in the 
 
 form of fire. It is possible that he testified his approval 
 
 of Abel's sacrifice by fire, as he frequently in after ages 
 
 thus marked his approbation. But we know that he 
 
 appeared to Moses in the burning bush ; to the children 
 
 of Israel in the wilderness, as a pillar of fire; and by 
 
C ' TM* *V 
 
 UNJVEftllTY 
 
 P*.,/* 
 
 "^ .:,;,*/ <*' 
 
 MOSAICAL AND MINERAL GEOLOGIES. 137 
 
 the same element to the high priest in the Holy of 
 Holies. If the early inhabitants of the world had 
 been accustomed to this consideration, it is not sur- 
 prising that they felt some reverence for that emblem 
 by which the Eternal had shewed himself; and in sup- 
 port of this view we might refer to the history of the 
 fire worshippers, and other historical inquiries. 
 
 But the sun and moon were pre-eminent objects of 
 admiration as the greater lights; and in addition to their 
 being apparently bodies of fire, their beneficial influence 
 upon the earth was well known. This admiration 
 might easily be converted into unholy reverence for 
 and worship of all the heavenly bodies; for such is still 
 the disposition of men towards things which they hold 
 in high esteem and veneration. 
 
 But, whatever may have been the application of this 
 assertion to the Israelites, there is a direct statement 
 that God created the heavens and the earth. This 
 was done before the six days; how long, we are not 
 informed, and are, consequently, at liberty to attempt 
 to determine it by the assistance of science. 
 
 The sacred historian then describes the state of the 
 earth at the time which immediately preceded the days 
 of creation. The passage should be thus rendered: 
 "But the earth was invisible and unfurnished." 
 
138 COMPARISON OF THE 
 
 The Hebrew conjunction van takes a variety of sig- 
 nifications; and it is only those that are accustomed to 
 the Hebrew language as their vernacular tongue, who 
 can immediately determine its proper meaning. Our 
 only method, therefore, of fixing the precise signification 
 of this particle is to consult the early Jewish rabbins. 
 
 "This conjunction, to which the elder Michaelis assigns 
 thirty-seven different significations, and Noldius up- 
 wards of seventy, is a particle which discharges in the 
 Hebrew language the functions of all the conjunctions 
 both copulative and disjunctive; its sense being deter- 
 minable in each particular case, only by the relation of 
 the context, and the practice and genius of the language." 
 (Perm's Comp. Estimate, v. i. p. 166.) By all modern 
 writers it is in the connexion to which we now refer 
 translated AND, by all the ancient Jewish rabbins, BUT. 
 By the Jews of Alexandria, who translated the Old 
 Testament into Greek nearly three hundred years before 
 Christ, it is rendered by the Greek particle AE, which 
 signifies but. Josephus also, in his paraphrase of the 
 passage, gives it the same meaning: "In the beginning 
 God created the heaven and the earth, but the latter 
 not coming into view, but being hidden in profound 
 darkness. (Joseph, Ant. Jews, v. i. p. 1.) St. Jerome 
 also understands it in the same way; and Grotius and 
 
MOSAICAL AND MINERAL GEOLOGIES. 139 
 
 others of the more modern commentators coincide in 
 the opinion. But at the time when God came forth to 
 create man, and to furnish the earth for his reception, 
 "the earth was invisible and unfurnished." 
 
 Mr. Penn's excellent remarks upon this passage have 
 established this translation. "That celebrated phrase, 
 tohu vabohu, on which fancy and system have so largely 
 and unsubstantially built, is not of uncertain significa- 
 tion, as has most inconsiderately and unwarrantably 
 been assumed or pretended; for we find the most 
 ancient interpretation of it, as delivered by native trans- 
 lators, uniformly maintained both in the Jewish and 
 Christian churches for above six hundred years after 
 their time; which prescription constitutes as solid and 
 secure an evidence of the primitive signification of the 
 terms as the most punctilious criticism founded on 
 reason can require or desire in any language. Those 
 words which our version, conforming to later translators, 
 has rendered "without form and void," are rendered by 
 
 the oldest Jewish interpreters, aoparoc Kal aKaraaKf.vaoTOQ, 
 
 invisible or unapparent, and unfurnished or unprovided. 
 So, also, they were interpreted by the learned Jew, 
 Philo. And that Josephus, whom Jerome calls "a 
 Hebrew skilled in sacred learning from his infancy," 
 understood the first of these words to signify in- 
 
140 COMPARISON OF THE 
 
 visible, is manifest from his paraphrasing it, not 
 coming into view. And Jerome avowedly regarded 
 this as the established interpretation so late as the close 
 of the fourth century, for, in his commentary on the 
 fortieth chapter of Isaiah, he says: "In the beginning 
 of Genesis, where it is written 'but theearth was invisi- 
 ble and unfurnished,' the other interpreters have trans- 
 lated 'but the earth was void and nothing. 7 ''' 
 
 There are two facts which we would deduce from this 
 statement by the inspired historian: that the world was 
 created at some indefinite period before the commence- 
 ment of the six days ; and that it was created at once, 
 without the interference of any secondary causes. 
 
 That the beginning does not refer to the first day 
 spoken of by Moses is certain, for it is not mentioned 
 as a part of the creation in the enumeration of that 
 day's work. But we are, on the contrary, informed 
 that on the first day it was in existence, though unfur- 
 nished and covered with water. The term beginning, 
 therefore, is indefinite, and it may refer to the preceding 
 day, or to thousands of years. To guesses there would 
 be no end, for one would be as authorized to assert the 
 truth of his conjecture as another; and at last must 
 leave the decision of the question to the results of an 
 examination into the constitution of the globe. 
 
MOSAICAL AND MINERAL GEOLOGIES. 141 
 
 This is the province of Geology, and from this source 
 only can we hope to decide the question, and to deter- 
 mine the state of the earth during the period which 
 intervened between its creation and the beginning of 
 the six days. 
 
 We are pleased to find that Dr. Chalmers does not 
 think this view of the Mosaical statement inconsistent 
 with the manner in which it is expressed, though we 
 cannot allow, with him, that the substance of the heavens 
 and earth was created before the things themselves. 
 "Does Moses ever say that, when God created the hea- 
 vens and the earth he did more at the time alluded to 
 than transform them out of previously existing mate- 
 rials? or does he ever say that there was not an interval 
 of many ages betwixt the first act of creation described 
 in the first verse of the book of Genesis, and said to 
 have been performed in the beginning ; and those more 
 detailed operations, the account of which commences 
 at the second verse, and which are described to us as 
 having been performed in so many days? or, finally, 
 does he ever make us to understand that the genealogies 
 of man went any further than to fix the antiquity of the 
 species, and of consequence that they left the antiquity 
 of the globe a free subject for the speculation of philo 
 sophers?" (Chalmers's Evid. Christ. Revela.) 
 
142 COMPARISON OF THE 
 
 Mr. Sharon Turner, also, well known and esteemed 
 for his valuable historical works, entirely agrees with 
 the principal we have advocated. "The Mosaic chro- 
 nology," he says, "begins with the formation of Adam, 
 and with the six preceding days or periods, which com- 
 menced with the production of light. What interval 
 occurred between the first creation of the material sub- 
 stance of our globe, and the mandate for light to descend 
 upon it; whether months, years, or ages, is not in the 
 slightest degree noticed. Geology may shorten or 
 extend its duration as it may find proper; there is no 
 restriction on this part of the subject." ( Turner's Sacred 
 Hist. p. 461.) 
 
 Another fact, derived from the first two verses of the 
 book Genesis, is, that the earth was made without 
 the intervention of any secondary causes. What defi- 
 nite idea can be formed of a substance that is without 
 form and void, we are at a loss to imagine. If we exa- 
 mine the cosmogony of the ancients, and even of the 
 moderns, we find they have equal difficulty with our- 
 selves. They have, consequently, invented chaos and 
 all its concomitant absurdities to give an idea to an 
 otherwise inconceivable statement, but at last darken 
 the imagination by words without meaning. Yet phi- 
 
MOSA1CAL AND MINERAL GEOLOGIES. 143 
 
 losophers have been highly delighted with this shape, 
 of their own imagination, 
 
 "If shape it may be called, that shape has none 
 Disti nguishable . " 
 
 Indistinctness, according to the metaphysicians, is 
 one of the sources of the sublime. If this be true, it is 
 not singular that poets should have delighted to dwell 
 upon the grandeur of chaos; and they have all been 
 successful, as might be expected, in discovering the 
 beauties of this fertile field of imagination. What 
 idea can possibly be collected from the following de- 
 scription by Ovid? 
 
 "Before the seas and this terrestrial ball, 
 And heaven's high canopy, that covers all, 
 One was the face of nature; if a face, 
 Rather a rude and undigested mass: 
 A lifeless lump, unfashioned and unfrarned, 
 Of jarring seeds; and, justly, Chaos named." 
 
 Dryden. 
 
 Our immortal Milton, the finest poet and the worst 
 divine, has no clearer conception of chaos than the 
 heathen bard : 
 
 " Before their eyes in sudden view appear 
 The secrets of the hoary deep; a dark 
 
144 COMPARISON? OF THE 
 
 Illimitable ocean ! without bound, 
 
 Without dimension; where length, breadth, and 
 
 height, 
 
 And time, and place, are lost; where eldest night 
 And chaos, ancestors of nature, hold 
 Eternal anarchy amidst the noise 
 Of endless wars, and by confusion stand: 
 For hot, cold, moist, and dry, four champions 
 
 fierce 
 Strive here for mastery." 
 
 Paradise Lost, b. ii. 1. 890. 
 
 It is strange that a doctrine so adverse to all scrip- 
 tural statements on the subject could ever find advocates 
 among Christians. The doctrine of chaos acknowledges 
 a creation of uncontrolled matter. If we suppose mat- 
 ter to have existed without Taking determinate forms, 
 it must have been created without laws. It is not 
 sufficient to say that some of those causes which now 
 influence it were not created, for even then matter must 
 have been lawless. But matter without laws is a pal- 
 pable absurdity. It must, therefore, at the moment of 
 its creation, have been invested with all those principles 
 which it evinces at the present moment; for the destruc- 
 tion of one necessarily includes the other. 
 
 And, if we acknowledge the eternity of matter, we 
 make it co-existent with the Eternal; and instead of 
 
MOSAICAL AND MINERAL GEOLOGIES. 145 
 
 making all things of nothing, all things were provided 
 for him. And we must, ultimately, with this suppo- 
 sition, acknowledge its existence without laws till the 
 formation of the world. But there are few who main- 
 tain the doctrine of chaos that give themselves the trou- 
 ble to examine into the meaning of the word, much less 
 to determine the doctrine it includes. 
 
 To the misconception of the second verse in Genesis 
 all the absurdities of Heathen chaos may be attributed. 
 The Chaldeans believed that darkness and water had 
 been eternal; and that Belus, dividing the two, formed 
 the world. This doctrine is evidently derived from the 
 Mosaical description of the state of the earth previous 
 to the days of the creation, and does not greatly differ 
 from common opinion in the present day. The Egyptians 
 held that chaos and an intelligent principle were co- 
 existent, and the Persians only differed from them in 
 imagining two active principles; one always attempting 
 good, the other evil. 
 
 "Epicurus," says St. Pierre, "exhausted by volup- 
 tuousness, formed his world and his atoms, with which 
 God has nothing to do, out of his own apathy ; the 
 geometrician forms it with his compasses; the chemist 
 compounds it of salts ; the mineralogist extracts it from 
 fire; and they who apply themselves to nothing, and 
 
146 COMPARISON OF THE 
 
 these are not few in number, suppose it, like themselves, 
 in a state of chaos, and moving at random. Thus they 
 fail not to interpret the sublime operations of nature 
 by the mechanism of the arts most familiar to them/' 
 
 But the doctrine of chaos is discarded by the sacred 
 Scriptures. GOD created the heavens and the earth ; or, 
 as the rabbins understood the passage, created the sub- 
 stance of them as well as formed the things themselves. 
 
 We then understand Moses to assert that at a certain 
 time, called the beginning, God created the heavens and 
 the earth; and that they as really appeared, and were 
 as really in existence, as they are at the present moment. 
 And that after they had existed an undetermined time, 
 God came forth to create man, and previous to that 
 ^act, fitted the world for his habitation; but, when he 
 commenced this work, the earth was unfurnished and 
 invisible. 
 
 It may now be inquired how far science and the facts 
 of geology in particular, coincide with and illustrate 
 these deductions. 
 
 Science, as we have already shown, demonstrates 
 that the world must have had a beginning, and that it 
 is the work of an intelligent and powerful being. We 
 may also, perhaps, deduce from the same source that 
 creation must have been an instantaneous, and not a 
 
MOSAICAL AND MINERAL GEOLOGIES. 147 
 
 progressive work. This will be best done by analogy, 
 by comparing the work of creation in one instance with 
 that in others. 1 
 
 Animals, though they have existed for generations 
 almost indefinite, have had a beginning, and must have 
 been created. How far soever we may trace generated 
 animals back, there was a moment in which they were 
 first called into existence ; and that moment must have 
 been after the creation of the earth. 
 
 Generated animal bodies undergo great changes in 
 their progress from birth to maturity. Bone, for 
 instance, when the animal is young, is soft, and some- 
 what flexible, but by the addition of ossifying matter, 
 it becomes harder and harder, until it is perfect 
 bone, capable of supporting the mature and healthy 
 animal. 
 
 Now in which of these states are we to suppose 
 animals to have been created? They cannot, we think, 
 have been formed in an imperfect state. Many animals 
 are, in the early stage of their being, unable to provide 
 themselves with food, and incapable of supporting life ; 
 and if they were created in this state, we must allow that 
 a considerable time must have passed before they could 
 have been capable of increase. It is, therefore, pro- 
 bable that, when animals were created, they were in a 
 
 L2 
 
148 COMPARISON OF THE 
 
 perfect and mature state, with all their functions in 
 that condition best adapted to the objects of their 
 being. 
 
 The same argument may be applied to the vegetable 
 creation ; and by analogy we conclude that the earth 
 itself was created in the same manner. Progression is 
 inconsistent with the exercise of creative power, although 
 it may be distinctly traced to a certain limit in all created 
 things. 
 
 Scripture and science are, therefore, agreed on this 
 point, that the earth had a Creator, and that it was 
 created at once, without the interference of any secon- 
 dary causes. 
 
 But the earth was not, we think, created alone; 
 the whole of those bodies constituting the solar system 
 were probably formed at the same moment: "God 
 created the heavens and the earth," not merely the 
 blue etherial space, but the bodies which revolve in it. 
 This is, evidently, the legitimate meaning of the inspired 
 writer. 
 
 It has already been shown that a period of time 
 intervened between the creation of the earth and the 
 beginning of the six days. During this period the 
 rocks which are the covering of the globe were, in all 
 probability, formed. The primitive rocks may have 
 
MOSAICAL AND MINERAL GEOLOGIES. 149 
 
 constituted the surface of the earth as it came from the 
 hand of the Creator; but if they did, they have since 
 suffered considerable alterations. It has been proved 
 in the observations upon Theoretical Geology, that all 
 the beds between the primitive rocks and the superficial 
 gravels were formed before the deluge, and that they all 
 resulted from causes similar to those which are now in 
 action. It is quite incredible that they could have 
 been deposited in that period which intervened between 
 the creation of man and the universal deluge. It is 
 naturally impossible, we think, that so vast a series 
 of deposits could have been formed in the time ; but, if 
 this objection should be considered insufficient, we 
 must allow that the whole earth was a long time beneath 
 the waters, for the secondary beds, with but few ex- 
 ceptions, were formed by the sea, and contain animal 
 remains. The beds of the secondary and tertiary 
 classes must, therefore, have been formed before the 
 creation of man, and during that period which inter- 
 vened between the creation of the earth and the begin- 
 ning of the six days. 
 
 To this it may be objected that, as these beds con- 
 tain vegetable and organic remains in great abun- 
 dance, light was absolutely necessary for their exist- 
 ence; yet the earth was, at the commencement of the 
 
150 COMPARISON OF THE 
 
 days, in darkness. This we admit, but if any person 
 should wish to draw from this a deduction that the earth 
 had always been in darkness, we object to the inference. 
 If this question must be left to deduction, there is as 
 much probability that the darkness was casual, as that 
 it began with the earth's creation, and remained upon it 
 till the commencement of the days. 
 
 It has been already proved that both the earth and 
 the heavenly bodies by which it is surrounded, were in 
 existence before the days of creation. To suppose that 
 they existed under circumstances different from those 
 in which they now exist, is an absurdity, and inevitably 
 leads to the doctrine of matter without laws. If the 
 sun and moon existed, they gave light to the earth, as 
 they have done since the creation of man, and will 
 ever do as long as they bear to each other the same 
 relations. 
 
 An argument in favor of our opinion might also be 
 drawn from the universal law of God in reference to his 
 creatures. All that he has made is intended to accom- 
 plish some good purpose, for he hath made nothing in 
 vain. Nor are these in reversion, but immediate. Use- 
 lessness, even for a period, cannot be an attribute of the 
 works of the Almighty ; they are not formed until required, 
 and cannot necessarily be allowed to remain without ful- 
 
MOSAICAL AND MINERAL GEOLOGIES. 151 
 
 filling his object. It is, therefore, impossible to suppose 
 that the world was created only to revolve in dark im- 
 penetrable space. 
 
 The existence of light from the beginning might also 
 be insisted upon from the fact that all inorganic matter 
 seems to have been only created to support the exist- 
 ence, and to administer to the comfort and pleasure, of 
 organized being. Every spot on the rich world we 
 inhabit teems with living creatures : from the sponges 
 which in all parts of the globe indiscriminately attach 
 themselves to animal, vegetable, and mineral, substan- 
 ces, to the more perfect animals, this fact may be traced. 
 Away from the uninviting and crowded cities, not a 
 step can be taken which, to explore, would fill the 
 little span of human existence. And to suppose that 
 this world could have existed for any lengthened period 
 without organized being, cannot for a moment be main- 
 tained by a naturalist. 
 
 Immediately after the creation of the earth, time 
 began. Matter was endowed with certain laws; these 
 laws immediately began to act; and the same causes 
 and effects were as active at that moment as they are 
 now. Matter being finite, was no sooner brought into 
 existence than it began to change its forms. The hard 
 and apparently indestructible rocks that bade defiance 
 
152 COMPARISON OF THE 
 
 to the whirlwind and u the storm, crumbled before the 
 gentle breeze of heaven and the soft ripples of the 
 ebbing tide. All outward causes contributed to its 
 degradation and ruin; and at the base of mountains 
 the debris was collected, or silently carried away by the 
 passing stream. 
 
 But these were not the only causes that had an 
 influence upon rocks: the hurricane and the tempest 
 were there, the volcano and the earthquake were there, 
 all the fierce and terrible agents of nature were there ; 
 rocks were broken and destroyed, upheaved and dis- 
 torted. From all these causes new strata were formed, 
 sometimes by the noiseless action of the rippling stream, 
 sometimes by the impetuous fury of the raging tempest, 
 and at others by the sudden and violent ejection of melted 
 rocks from beneath, through the vast fissures which the 
 struggling gases had opened. 
 
 To that series of rocks which rests upon the primitive, 
 the above description may be applied. They consist of 
 the fragments, large and small, of the primitive rocks 
 united together, and have been tilted by the volcanic 
 action from beneath, and not unfrequently mingled 
 with the intumescent masses they have thrown up. 
 
 But the earth was not at this time an uninhabited 
 desert. In the transition rocks we find a considerable 
 
MOSAICAL AND MINERAL GEOLOGIES. 153 
 
 variety of shells belonging to both extinct and existing 
 genera. Some of these were fitted to live in the fathom- 
 less deep, others to float over the surface of the broad 
 ocean. The remains of a few fish and several genera of 
 ^corals are associated with them. It is also interesting 
 to know that at this period there was dry land as well 
 as sea, and that it was not destitute of vegetation. 
 The impressions of plants have been found in these 
 strata, and in some places in great abundance. Whe- 
 ther any terrestrial creatures existed at this time we 
 are unable to say; none of their remains, if there were 
 any, have been found; and we must, therefore, for the 
 present, suppose that they did not. 
 
 Immediately above the transition rocks we find the 
 coal deposits, and the rocks which are associated with 
 them. During the formation of these deposits the 
 waters were, as in the preceding period, inhabited by 
 testaceous animals and fishes. But the beds differ 
 from the transition in the great abundance of vegetable 
 matter, of which coal is entirely composed. In many 
 of the strata connected with coal, the remains of vege- 
 tables are very numerous, and of considerable size, the 
 ferns being sometimes fifty or sixty feet in length. The 
 entire series may be said to be remarkable for the great 
 
 
154 COMPARISON OF THE 
 
 abundance and size of the cryptogamic plants which are 
 imbedded in them. 
 
 The state of the earth during the deposition of these 
 beds was decidedly different from that which obtained 
 during the formation of the transition rocks. The 
 violent impetuosity of existing causes was much sub- 
 dued, although there are many proofs of considerable 
 volcanic activity. 
 
 The fossil plants which are found in the coal strata 
 usually occur in an horizontal position, as though they 
 had been uprooted and thrown down previous to their 
 being imbedded. But in some instances they are found 
 in a vertical position, proving that the deposition of the 
 bed in which they are found was so quiet and yet so 
 rapid as to entomb them without injury. In every 
 instance there seems to have been an absence of all 
 violence; and if they did not grow in the positions 
 where we find them, they were floated along by a per- 
 fectly quiet sea. 
 
 It is now generally supposed that the vegetables which 
 we find in this series grew upon islands scattered through 
 the seas. This supposition is maintained upon the fact, 
 that the class to which they belong is such as requires 
 considerable heat and moisture; and all those species 
 
 
MOSAICAL AND MINERAL GEOLOGIES. 155 
 
 of the present day which have the same character and 
 approach them in size, are similarly situated. 
 
 It is a singular fact that the vegetables which are 
 found in a fossil state are furnished with organs of res- 
 piration, peculiarly adapted for imbibing the nutritious 
 principles of the atmosphere. The greater number of 
 fossil plants were succulent, and it is well known that 
 the recent plants of the same character depend more 
 upon the atmosphere for their existence than the soil in 
 which they grow. This class of plants was therefore 
 peculiarly adapted to a world rapidly progressing towards 
 a state fitted for the existence of more perfect animals. 
 
 We may consider the earth at this period as consisting 
 of land and water; for land was not only requisite for 
 the growth of the vegetables whose remains we find, but 
 there is evidence, from the extent of the mechanical rocks 
 which abound in this series, that a considerable surface 
 must have been above the waters. 
 
 Above the coal beds we observe a large system of me- 
 chanical rocks, called the red sandstone series. It is 
 among these the remains of reptiles are first found, as 
 well as other animals which have not been yet discovered 
 in the lower strata. 
 
 It may be asked whether, upon the discovery of 
 new genera, it may be supposed that they did not exist 
 
156 COMPARISON OF THE 
 
 previous to the time when the deposit in which they are 
 found was formed. Some Geologists have maintained 
 the successive creation of animals, because they find 
 certain beds to contain fossils which are not discovered 
 in others. This, however, is a mere supposition, and 
 does not by any means result from discovered facts, 
 though it may be supported by strong probabilities ; but 
 if we look at modern formations and the laws of nature, 
 which have ever been what they are, we may perhaps 
 discover other arguments. Let us suppose the causes 
 which are now effecting a deposition of clay to be des- 
 troyed, and a siliceous sand to be thrown down ; a great 
 portion of testaceous animals now living in such a place 
 would in all probability be destroyed. Every animal is 
 suited to particular circumstances; change the condition 
 in which it lives, and you will probably destroy the 
 animal. This is a subject which requires extensive ob- 
 servation; but, although it cannot be demonstrated by 
 the results of examination that this is the cause which 
 produced organic remains, it has so much probability 
 on its side, as to lead those who maintain successive 
 creations, to investigate with more care recent strata 
 and their fossils. 
 
 A variety of causes may have prevented the remains 
 of an animal from being imbedded in a series of rocks. 
 
MOSAICAL AND MINERAL GEOLOGIES. 157 
 
 It is quite possible that certain genera of animals may 
 have lived during the entire period occupied by the for- 
 mation of the transition rocks, and coal series, and yet 
 not have been embedded in either. We may suppose 
 that there are many testaceous animals that have existed 
 in our own seas for centuries, and yet none of their re- 
 mains have been imbedded in the strata that are there 
 forming. This may result from local or general causes, 
 the habits of the animals, or the localities they inhabit; 
 and it is not impossible that we may overlook in many 
 instances, the remains which are in certain beds, or they 
 may be so sparingly distributed that our researches have 
 not been sufficiently extensive to discover them, and 
 that future investigators will find them in places which 
 we now imagine to be destitute. 
 
 It is therefore hazardous to say that the reptiles which 
 are first found in the red sandstone group did not exist 
 previous to the time in which it was formed, although 
 there is a decided change in the character of the organic 
 remains. 
 
 Upon the red sandstone series there lies an immense 
 group called the Oolites. Here we meet with a variety of 
 animals which are perfectly new; several new genera of 
 reptiles, testacea, zoophytes, and plants. It appears as 
 if the waters had been more fully inhabited ; the violent 
 
158 COMPARISON OF THE 
 
 actions which prevailed in the early ages of the world 
 seem to have subsided in a great measure, and to have 
 given place to more tranquil causes. 
 
 The last and highest series of the secondary rocks 
 are the weald en and cretaceous groups. During the 
 formation of these, the earth was fully inhabited ; for 
 they are crowded with the remains of animals chiefly 
 inhabiting the ocean or estuaries. The earth at this 
 time probably presented an appearance not very different 
 in general characters from that which we now observe; 
 sometimes we meet with tilted beds, and here and there 
 with volcanic rocks; but those violent agents which in 
 the earlier ages of the world had acted so destructively 
 upon the world, had almost entirely passed away. 
 
 The tertiary beds, or the largest part of them, were 
 probably formed at the same time. But to fix upon a 
 particular stratum in the present state of our knowledge, 
 and say, all below this were formed before the days, all 
 above it, after, is a species of knowledge which we* 
 do not pretend to claim ; but it is possible that many of 
 the beds now associated with the tertiary deposits, may 
 hereafter be proved to belong to the diluvian age. 
 
 It is evident then, both from Genesis and Geology, 
 that after the creation of the earth and before the days, 
 all or nearly all the fossiliferous rocks which compose 
 
MOSAICAL AND MINERAL GEOLOGIES. 159 
 
 the crust of our globe, were formed. The character 
 and appearance of the earth as it first came from the 
 hand of its Creator, science will ever be unable to de- 
 termine ; but Geology beautifully illustrates the suc- 
 cessive history of that extended period which intervened 
 between the creation and its complete adaptation, as 
 the residence of man. 
 
 That the same process is still going on in some of the 
 planets of the solar system, is not an improbable sup- 
 position : the nearer the planet may be situated to the 
 sun, the greater, we have thought, is it to a perfect state. 
 Mercury is consequently in the most perfect condition; 
 but, at the same time, only in such a state as most 
 adapted to its present inhabitants. But Jupiter appears 
 from observation to be almost entirely covered by water; 
 and of the violence of its action when attracted by the 
 united influence of its four moons in conjunction, imagi- 
 nation is too feeble to paint. But, whatever degree of 
 truth there may be in this supposition, it is certain that 
 the earth has arrived at its present condition by slow 
 and progressive steps. 
 
 Having taken this general view of the state of the 
 earth during that period which intervened between the 
 creation of the world and the commencement of the 
 days, the state of the earth at the latter period, and 
 
160 COMPARISON OF THE 
 
 the successive creations which followed, may be briefly 
 noticed. 
 
 At the commencement of the days, the "earth was 
 invisible, and unfurnished, and darkness was upon 
 the face of the deep." There is here an evident 
 distinction between the earth and the deep; they were 
 both invisible, and the former was unfurnished. By 
 this statement we may either understand that dark- 
 ness was upon both, and that all which existed upon the 
 land had been destroyed; or that the earth was covered 
 with water. The latter is probably the meaning; for 
 we find that, on the third day, God gathered the waters 
 together into one place, and caused the dry land to 
 appear. 
 
 The cause of this universal deluge and darkness, is 
 not stated by Moses; but, according to the view which 
 has been taken of the state of the earth preceding this 
 period, it must have suffered a most important revolution. 
 Land and water had existed during the deposition of 
 rocks, and, in order to the accomplishment of the uni- 
 versal deluge, a sinking or elevation of strata seems to 
 be necessary, or the interference of that miraculous 
 Power which in after ages again encompassed the 
 earth with floods ; and the same Power which brought 
 the waters over the globe, covered it, with darkness, 
 
MOSAICAL AND MINERAL GEOLOGIES. 161 
 
 which was, in all probability, transient; as we know 
 that the sun and planetary bodies which act so important 
 a part in conveying light to the world, were certainly 
 created. 
 
 Much has been written concerning the word, IOM, 
 translated in this place, day. This word has various 
 acceptations in Scripture, which may be mentioned. 
 
 1. Sometimes it signifies four and twenty hours; a 
 single revolution of the earth on its axis. This is the 
 sense in which it is used by Ezekiel: "Thou shalt bear 
 the iniquity of the House of Judah forty days; I have 
 appointed thee each day for a year." (Ezekiel, iv. 6.) 
 
 2. When it is used in the plural number it often sig- 
 nifies a year. It is thus used in Leviticus, (xxv. 29,) 
 "If a man sell a dwelling-house in a walled city, then 
 he may redeem it within a whole year after it is sold." 
 
 3. Sometimes it denotes an undefined period of time ; 
 it is thus used by the prophet Joel, (i. 15,) "Alas for 
 the day, for the day of the Lord is at hand." 
 
 As used by Moses, in describing the Second Creation, 
 the word evidently, we think, refers to a single revolution 
 of the earth round its axis. If any proof of this were 
 wanting, the use of the phrase "the morning and the 
 evening," would decide the question. 
 
 The earth being in darkness at the commencement of 
 
 M 
 
162 COMPARISON OF THE 
 
 the days, God first calls or recalls the light ; for there is 
 nothing in the Mosaical statement that precludes the 
 idea that light in the same form as it was now exhibited 
 had existed before; but, on the other hand, every thing 
 to strengthen the opinion. 
 
 On the second day, God created the firmament, and 
 divided the waters, which were under the firmament, 
 from those which were above. 
 
 On the third day the waters under the heavens, which 
 had hitherto covered the whole earth, were gathered 
 together into one place, and the dry land appeared. On 
 the same day the earth was decked with its living green, 
 and it brought forth the herb and the tree, each yielding 
 fruit after its kind. 
 
 In order to the gathering of the waters together, some 
 great convulsion must have transpired. On this subject 
 we derive some information from another part of the word 
 of God : " O Lord, my God !" says the Hebrew poet, "thou 
 art clothed with honour and majesty; who laidest the 
 foundations of the earth that it should not be removed for 
 ever. Thou coveredst it with the deep as with a garment; 
 the waters stood above the mountains. At thy rebuke 
 they fled ; at the voice of thy thunders they hasted away; 
 they went over the mountains, they went down by the 
 valleys unto the place which thou didst found for them." 
 
MOSA1CAL AND MINERAL GEOLOGIES. 163 
 
 In this beautiful passage we obtain a clearer view of 
 the operations of the MOST HIGH in gathering the waters 
 together. Valleys were formed, and these were probably 
 the places which were found for them. We are, therefore, 
 led to suppose that there was a sudden upheaving of a 
 considerable portion of the solid crust of the earth. 
 
 Let us suppose for a moment that some of those 
 immense mountain chains were elevated, or the whole 
 continents of which they form a part. The mighty 
 waters which so calmly flowed over the surface would 
 be thrown into an inconceivable agitation, and roll their 
 disturbed waves from shore to shore, until they had 
 found that bound which they should not pass ; and of 
 such a convulsion there are abundant proofs in the state 
 of the earth's crust. 
 
 What the extent of the effects produced by such a 
 convulsion would be, it is almost impossible to conceive. 
 But if the deluge strewed our world, from pole to pole, 
 with the relics of its destructive agency, how large 
 must have been the accumulation of detritus, which 
 must have been produced by the actual upheaving of 
 the continents ? To this cause we assign many of those 
 tertiary deposits which have hitherto been supposed to 
 have existed before the days of creation. And if 
 this be their origin, it is not surprising that they 
 
 M 2 
 
164 COMPARISON OF THE 
 
 should differ so considerably in their mineralogical 
 characters. 
 
 On the fourth day God set apart the heavenly bodies 
 for a distinct and separate purpose. "If any one," 
 says Rosenmuller, "who is conversant with the genius 
 of the Hebrew, and free from any previous bias of his 
 judgment, will read the words of this article (that is, 
 the history of the fourth day's work,) in their natural 
 connexion, he will immediately perceive that they 
 import the direction or determination of the heavenly 
 bodies to certain uses which they were to render to the 
 earth. The words are not to be separated from the 
 rest, or to be rendered, Let there be lights, that is, let 
 lights be made; but rather, Let lights be; that is, serve, 
 in the expanse of heaven, for distinguishing between 
 day and night; and let them be, or serve, for signs and 
 for seasons. For we are to observe that the verb, nVT, 
 to be, in construction with the prefix, b,for, is generally 
 employed to express the direction or determination of a 
 thing to an end, and not the production of a thing, as in 
 Num. x. 31; Zech. viii. 19; and in many other places." 
 
 In accordance with this criticism, Mr. Penn trans- 
 lates the passage in the following manner : "And God 
 said, let the lights in the firmament of heaven for 
 dividing the day and the night be for signs and for 
 
MOSAICAL AND MINERAL GEOLOGIES. 165 
 
 seasons, and for days and for years; and let them be 
 for lights in the firmament of heaven to give light upon 
 the earth ; and it was so. 
 
 "And God made the two great lights; namely, the 
 greater light to rule the day, and the lesser light to 
 rule the night, together with the stars. And God 
 disposed them in the firmament of heaven to give light 
 upon the earth, and to rule the day and the night." 
 
 If this translation be admitted, we have here the 
 existence of the heavenly bodies previous to this time 
 directly implied ; which fully corresponds with the view 
 we have taken of their creation in the beginning. If it 
 had been asserted that the heavenly bodies were at this 
 time called into existence, it would have contradicted 
 the statement in the first verse, but they were only set 
 apart for a certain end, which was to rule the day and 
 the night. They, therefore, existed before, and pro- 
 bably for many ages, and may have performed the same 
 office previous to that catastrophe which covered the earth 
 with darkness, and rendered it necessary for the Eternal 
 to come forth and re-furnish and re-enlighten that 
 world on which he intended to place his creature, Man. 
 
 The earth being thus prepared as the habitation of 
 organized creatures, God creates, on the fifth day, all that 
 moveth in the waters and in the air. On the sixth day 
 
166 COMPARISON OF THE 
 
 He completes his work by the creation of all living crea- 
 tures that inhabit the earth, "cattle, and creeping things, 
 and beasts of the earth." Then "God created man in 
 his own image; in the image of God created he him." 
 
 We have thus hastily reviewed the work of the six 
 successive days of creation, in order to show the perfect 
 concord of this history with the view we have taken of 
 the former verses. "Moses," says Dr. Buckland, who 
 is an authority of the highest class, "does not deny the 
 existence of another system of things prior to the pre- 
 paration of this globe for the reception of the human 
 race, to which he confines the details of his history; 
 and there is nothing in the proposition inconsistent with 
 the Mosaical declaration of the creation." But it is 
 not sufficient to say that Moses does not contradict the 
 supposition, for if the view taken of his history be 
 correct, he supports and establishes the opinion. 
 
 But, whatever may be the fate of human opinions, 
 one principle can never be disproved, that, God being 
 the author of both the Bible and the world, the testi- 
 mony of both, when accurately read, must correspond. 
 How disdainfully soever, the divine testimony may be 
 treated by some who are ardently engaged in the inves- 
 tigation of nature, all theories that oppose its state- 
 ments have error as their basis, and must fall to decay. 
 
MOSAICAL AND MINERAL GEOLOGIES. 167 
 
 Viewing Geology in connexion with the Mosaical 
 history, it is the noblest science to which the reason of 
 man can be applied. Too long has imagination wielded 
 her sceptre over the mind of the philosopher; she has 
 infused her baneful influence into every opinion, retarded 
 every investigation, and dashed from every lip the cup 
 of knowledge. Imagination is an attribute inconsistent 
 with the investigation of nature; and the province of 
 the philosopher is to delineate her as she is, and not in 
 the tawdry robes and false tints with which his imagi- 
 nation has dressed her. In some sciences this ruling 
 power is of less importance than in others. The astro- 
 nomer, when, by the aid of his glasses, he brings the 
 bright orb of night to the end of his telescope, may 
 speculate upon the composition of its mountains, the 
 brightness of its flora, or the character of its inha- 
 bitants; but his science is unaffected by his wildest 
 imaginings. And when he comes to the admeasurement 
 of her surface, or to calculate the periods of her eclipses, 
 all the tales of mythologists may ramble through his 
 mind, but will be unable to convince him that she is 
 any thing else than a dense body, or that her surface 
 will be darkened one moment before she is in conjunc- 
 tion with the earth and the sun. But in Geology the 
 matter is far different : every fact gives an opportunity 
 
 - THE x \ 
 
 UNIVERSITY )) 
 
 e* * J 
 
 J^ti^OHN t^ 
 
168 COMPARISON OF THE 
 
 for a new hypothesis, and imagination may soon run 
 wild in a scene of such novelty and grandeur. 
 
 In investigating the ancient history of the globe, the 
 mind should be separated at once from all prejudices, 
 and the reason should guard it from the influence of 
 imagination. It is a subject which, pursued by an 
 enlightened mind, fixes the attention and delights the 
 reason. If the antiquary can feel an interest in explain- 
 ing the almost-obliterated traces of art and civilization, 
 still greater will be the delight of removing the obscurity 
 which hangs over the history of our globe; and by 
 deductions from a series of observations, to connect the 
 broken fragments which are preserved in the word of 
 truth, to direct our investigations, and develope its 
 revolutions. Genius may here find its resource, and 
 may expend all its powers with increasing delight. At 
 present, we have only an indistinct view of the history 
 of the world we inhabit; but when its various revolu- 
 tions shall be determined, and the character of its past, 
 inhabitants explained, it will present the finest display 
 of Almighty power and the capacity of human intellect, 
 that literature ever produced, or science has ever afforded. 
 
 FINIS. 
 
 AOLARD, PIUNTERS, BARTHOLOMEW CLOSK. 
 
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