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LECTURES ^ 
 
 
 ON 
 
 I GEOLOGY; 
 
 BEING OUTLINES OF THE SCIENCE, 
 
 DELIVERED IN 
 
 THE NEW-YORK ATHEN^UM. 
 
 In the year 1825. 
 BY 
 
 JER.,|VAN RENSSELAER, M. D^ 
 
 i \ 
 Associate, and Lecturer nn frfttlogy in the. *Athe.na>mn t 
 
 Member of the Royal Medical Soc. Edin. ; Cor. Memb. of the Royal Aca- 
 demy of Sciences, Naples; of the Linnean Soc. of the Society of Encou- 
 ragement, and of the Medico-physic. Soc. Fans; Director of the American 
 Academy of Fine Arts ; Cor. Sec'y. of the Lyceum of Natural History, and 
 of the New York Horticultural Soc, Sec'y- of the Liter, and Philosop. Soc. 
 and Member of the Historical Soc. New York ; Member of the Soc. of 
 Natural History, Leipzic of the Soc. for promotion of Arts, and Cor. of 
 the Lyceum, Albany. 
 
 NEW-YORK : 
 
 PUBLISHED BY E. BLISS & E! WHITE, 128 BROADWAY. 
 H. SPEAR, PRINTER* 
 
 sp 
 
 1825. 
 
of New- York, ss. 
 
 BE IT REMEMBERED, That on the fourteenth day of May, A. If- 
 1825, in the forty ninth year of the Independence of the United States of 
 America, E. Bliss &E. White, of said District, have deposited in this office 
 the title of a Book, the right whereof they claim as Proprietors, in the words 
 following, to wit : 
 
 " LECTURES ON GEOLOGY: being outlines of the Science, delivered 
 in the New-York Athenaeum, in the year 1825. By Jer. Van Rensselaer, 
 M. D. Associate, and Lecturer on Geology to the Athenaeum, Member of 
 the Royal Medical Sco. Edin. ; Cor. Memb. of the Royal Academy of 
 Sciences, Naples ; of the Linnean Soc. of the Society of Encourage- 
 ment, and of the Medico-physic. Soc. Paris ; Director of the American 
 Academy of Fine Arts: Cor. Sec'y. of the Lyceum of Natural History, and 
 of the New York Horticultural Soc. Sec'y. of the Liter. andPhilosop. Soc. 
 and Member of the Historical Soc. New York ; Member of the Soc. of 
 Natural History, Leipzic of the Soc. for promotion of Arts, and Cor. of 
 the Lyceum, Albany. 
 
 In conformity to the Act of Congress of the United States, entitled " An 
 Act for the encouragement of Learning, by securing the copies of Maps, 
 Charts, and Books to the authors and proprietors of such copies, during the 
 time therein mentioned." And also to an Act, entitled " An Act, suple- 
 mentary to an Act, entitled an Act for the encouragement of Learning, by 
 securing the copies of Maps, Charts, and Books to the authors and proprie- 
 tors of such copies, during the time therein mentioned, and extending the 
 benefits thereof to the arts of designing, engraving, and etching historical 
 and other prints." 
 
 JAMES DILL, 
 Clerk of the Southern District of New-York. 
 
TO 
 
 MY FELLOW ASSOCIATES 
 OF THE 
 
 THIS WORK IS DEDICATED, 
 
 AS A MARK OF RESPECT 
 FOR THE HONOURABLE ZEAL 
 
 AND . 
 
 DISINTERESTED VIEWS 
 
 THEY HAVE MANIFESTED 
 XN ESTABLISHING THE INSTITUTION, 
 
LIST OF ASSOCIATES, 
 
 Rev. W. Harris, D. D. PRESIDENT. 
 
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 R. Adrain, L. L. D. 
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 H. Brevoort, Jr. Esq. 
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 Hon. J. J. Morgan, 
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 Hon. G. C. Verplank, 
 J. Verplank, Esq. 
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PATRONS OF THE NEW-YORK ATHENJEUM, 
 
 David Andrews, 
 David Austen, 
 Wm. Adee, 
 James Boggs, 
 Hendrick Booraem, 
 Francis Barretto Jr. 
 Wm. Bayard, 
 C. J. Burckle, 
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 J. Balestier 
 H. Booraem, 
 Cornelius Baker, 
 Isaac Carow, 
 Duncan P. Campbell, 
 John S. Crary, 
 John G. Coster, 
 Henry Cotheal, 
 Russell Comstock, 
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 Robert Gill, 
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Vll. 
 
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 Jr. 
 
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 GOVERNORS. 
 
 William B. Astor, 
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Vlll. 
 
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 John Watts, Jr. 
 
 G. W. Wallis. 
 
When the Lecturship on Geology was instituted 
 in the New York Athenaeum, it was not supposed 
 that the class of students would exceed 30 or 40 
 young persons, novices in the science. The bril- 
 liant success that has attended the establishment 
 of the Institution was not then anticipated. It was 
 with no small degree of reluctance and timidity 
 therefore that the Lecturer addressed a large and 
 enlightened audience. Nor was that timidity less 
 than the satisfaction he afterwards experienced, 
 on being advised by those who are admitted to be 
 capable of judging, to submit the Lectures to the 
 public. 
 
 The Lecturer has been the more willing to pub- 
 lish these outlines, since in this country, Geology 
 is generally considered as embracing a knowledge 
 of rocks merely, or positive geognosy ; whereas, 
 that study, though a very interesting and valuable 
 one, is, in fact, but a part of the science. There 
 is no work published, it is believed, that even hints 
 at the many important points properly treated of 
 under the head of geology : most authors on this 
 
subject having confined themselves to Theories 
 and Rocks. Nor is there any work that from its 
 size and arrangement and authority is well calcu- 
 lated to be placed in the hands of the student. 
 It is hoped that the present volume, while it offers 
 in the plainest possible language, a more extend- 
 ing outline of the science, is sufficiently condensed 
 for that purpose ; and that it will fill, in some 
 measure, the gap so universally acknowledged to 
 exist, until a more general and more able produc- 
 tion shall supercede it. 
 
 It is by no means intended to impress upon the 
 reader a belief that these Lectures are the re- 
 sult of personal observation. On the contrary, 
 much of what is found in the following pages is dis- 
 tributed through the writings of preceding enqui- 
 ries. Numerous and extensive opportunities for 
 the study of geological phenomena in Europe and 
 America may have given the Lecturer some right 
 to form his own opinions ; yet as these have gene- 
 rally coincided with the ideas of others, liberal re- 
 sort haslbeen made to Humboldt, Macculloch, 
 Conybeare, and Phillips, &c. &c. and it is believed 
 that a comparison of the views and observations of 
 such philosophers will vouch for every fact stated 
 in this work. ,T. V. R 
 
 Feb. 22d 1825 
 
CONTENTS. 
 
 LECTURE 1. 
 
 introductory remarks 'Divisions of Natural His- 
 tory Geological theories Stewart's opinion 
 of theories Fontanelle's, Bailly's. Theory 
 of Burnett Protogaea of Leibnitz. Theories of 
 Wooodward, Hook, Hally, Whiston, Lazoro 
 Moro, De la Pryme, King, Deluc, Guettard, 
 Lister, Lehman, Whitehurst, Kirwan, Buffbn, 
 Button, Saussure, Pallas, Werner Observations 
 on the theories of Huttori and Werner. Deluge, 
 traditions of it. American Geologists. Striking 
 coincidences between Sacred History and the 
 discoveries of Geology 13 
 
 LECTURE II. 
 
 Objects of Geology its utility to the farmer, min- 
 er and architect. Position of Rocks division 
 of them into classes Observations on the Pri- 
 mary Rocks, on the Transition, the Secondary, 
 the Tertiary, and Alluvial. Organic remains. 
 Divisions of the Earth's Surface Bottom of the 
 Sea Dryland, Lowland Alpine land Moun- 
 tain Groups and chains Observations on the 
 position and declivities of mountains -Val- 
 lies 54 
 
X11 CONTENTto. 
 
 LECTURES III. 
 
 Changes produced on the Earths surface, by the 
 formation of Peat, &,c. Coral reefs Volca- 
 noes Observations on their structure, position, 
 &c. Vesuvius Etna Sabrina Earthquakes, 
 those of Lisbon and Calabria Volcanic Fire 
 its Intensity, Situation and Origin . . 95 
 
 LECTURE IV. 
 
 Minerals entering into the composition of Rocks 
 Different forms of Rocks masses, beds, strata, 
 nodules, veins Internal structure of Rocks 
 laminar, fibrous, spheroidal, prismatic, veined, 
 cavernous, amygdaloidal, aggregate, granular, 
 porphyritic Texture Fracture Hardness 
 Color Frangibility Lustre Trasparency 
 Specific gravity Action of Acids . .126 
 
 LECTURE V. 
 
 Primary Rocks. Granite Gneiss Mica Slate 
 Argillite Serpentine Limestone Quartz 
 Rock Chlorite Schist Talcose schist Horn- 
 blende Rocks Actynolite Schist Porphyry- 
 Syenite Identity of Formations Isocronism 
 Alternation Loxodromism character of pri- 
 mary soils. . . . . 146 
 
CONTENTS X11I 
 
 LECTURE VI. 
 
 Transition rocks Argillite Greywacke Lime- 
 stone- Gypsum -Porphyry Syenite Green- 
 stone Secondary rocks Observations on their 
 formation Old Redsandstone Coal indica- 
 tions of it Shale Limestone Rock Salt Va- 
 riegated Sandstone Shell Limestone Lias 
 oolites Iron sand Greensand Chalk Ter- 
 tiary Formations of France of England 
 of America Alluvial and Diluvial Overlying 
 Rocks conclusion . . . .199 
 
 SYNOPSES OF ROCKS. 
 
 Granite . ... 274 
 
 Gneiss 276 
 
 Mica slate 279 
 
 Argillite . ... 281 
 
 Serpentine ... . 286 
 
 Primary Limestone . . . 287 
 
 Quartz rock .... 290 
 
 Clorite schist 292 
 
 Talcose schist ... 294 
 
 Hornblende rocks . . . 295 
 
 Actynolite schist . . . 298 
 
 Old Redsandstone . . 299 
 
 Coal 301 
 
 Peat 304 
 
XIV CONTENTS. 
 
 Shale ..... 305 
 
 Gypsum . . . . 307 
 
 Secondary Limestone * , . 307 
 
 Sandstones (superior) . . 311 
 
 Clay 314 
 
 Marie 315 
 
 Sand . . . . . . 316 
 
 Alluvia 316 
 
 Superincumbent or overlying rocks 320 
 
 Volcanic rocks . 337 
 
 Conglomerates .... 342 
 
 Tabular arrangement of Rocks by Hum- 
 
 boldt 350 
 
 Werner's Arrangement , . 355 
 
 Macculloch's do, .... 356 
 
 List of Fossil organic remains 357 
 
LECTURE I. 
 
 Introductory Remarks Divisions of Natural His- 
 tory Geological Theories* Stewards Opinion of Theo- 
 ries, Fontanette's, Bailly's Theory of Burnett, Pro- 
 
 togcea of Leibnitz Woodward -Hook Halley 
 
 Whiston Lazoro Moro De la Pryme King 
 
 Deluc Guettard Lister Lehman Whitehurst 
 
 Kirwan Buffon Hutton Saussure Pallas Wer- 
 ner. Observations on the Theories of Hutton and 
 Werner. Deluge, traditions of it. American Geo- 
 logists. Striking Coincidences between Sacred History 
 and Geology. 
 
 While we are prospering in Commerce and the 
 Arts, it is gratifying to every liberal mind that 
 Science is cherished in our country, and that the 
 great cause of intellectual improvement has be- 
 come one of the most popular. 
 
 When the Sun of Science, towards the close of 
 the 1 5th century, dawned on Europe, from the 
 
 dark cloud, which, for nearly 400 years, had en- 
 3 
 
rapt intellectual progress, there were but lour 
 classics in the Royal Library of Paris: France 
 and England were in barbarism; America undis- 
 covered. 
 
 A taste for polite literature was first spread over 
 the west of Europe by the fall of the Eastern 
 Empire, and the consequent dispersion of the 
 Greeks. It was enhanced by the noble dis- 
 covery of the Art of Printing, which secured to 
 itself the patronage afforded by the enlightened 
 and liberal minds of a succession of Popes. They 
 encouraged learning and the sciences, and in dis- 
 seminating them, gave full assurance of the per- 
 petuation of this valuable Art, and of the progres- 
 sive improvement of human knowledge. But 
 Philosophy was not courted with the zeal 
 paid to Literature : Aristotelian maxims contin- 
 ued to be universally received until the 17th cen- 
 tury, when Bacon, Lord Verulam, the profound 
 philosopher, and most universal genius of any age. 
 dissipated the mist of error, and threw a blaze of 
 light on useful science, by which experiment and 
 observation were discovered to be more convin- 
 cing than system and hypothesis. 
 
 In slightly adverting, as I have done, to Peri- 
 patetic philosophy, it is unnecessary to recall your 
 
attention to the school of Plato, the father of an- 
 cient philosophy ; or to follow the division of his 
 school by Zenocrates and Aristotle, However 
 delightful the task, we shall refrain from entering 
 and enjoying the Academy of the one, nor shall we 
 walk in the delightful suburban grove of Athens* 
 with the other. We need not trace that philosophy 
 which was patronised by Julius Caesar and Au- 
 gustus ; which was taught by Alexander of Ana- 
 phroedeseus ; introduced among the Jews by Aris- 
 tobolus, and among the Arabians by Al Mamon. 
 To this omission I am the more reconciled, since 
 a learned exposition of that school has already 
 been laid before you, in the eloquent discourses of 
 my colleague, on the history of the philosophy of 
 the mind. I must be allowed to say, however, that 
 it was that philosophy, which in the earliest ages 
 of Christianity rendered itself obnoxious to the 
 church, by its doctrine of the eternity of the 
 world. Still it forced its way within the Chris- 
 tian pale, and re-established its reputation : and 
 from the 5th century the Aristotelian philosophy 
 rose or fell with science in general, until its incon- 
 sistency with religion and true philosophy was ex- 
 posed, at the period I have mentioned, by Bacon, 
 the father of experimental philosophy. Bacon ! 
 
16 
 
 unhappy name in the annals of science ! "the 
 wisest, brightest, meanest of mankind," a blazing 
 beacon, to show us the fallacy of man in founding 
 his reputation on literary or scientific attainments, 
 not supported by moral principle to show us that 
 genius and talents, when not connected with vir- 
 tue, " but lead to bewilder and dazzle the blind." 
 
 By the happy constitution of society in this 
 country, few are enabled to devote themselves ex- 
 clusively to the study of nature. As in politics 
 and in morals, so in literature and in science, we 
 form individually but separate links, which, when 
 united, become one strong chain. Like the fed- 
 eral government, which is composed of, and up- 
 held by, our different states, so the republic of 
 literature must depend on the combined exertions 
 of many. 
 
 Our local position, our government, our freedom 
 of religion, are all peculiar to us ; but not so our 
 literature ; that we possess in common with Eu- 
 rope, nay, with Britain only. With different laws, 
 opposite governments, and in different hemis- 
 pheres, America and Britain enjoy, in the same 
 language, a common fund of literature, to which 
 they both add according to ability, and whence 
 they both draw according to inclination. Accord- 
 
17 
 
 ingly, the Naturalists of Europe send us frequent 
 and important acquisitions in the sciences, and 
 we endeavour to repay the obligation by our re- 
 searches on this side of the Atlantic. 
 
 It is within the recollection of many of those, 
 whom, by the partiality of my Associates, I have 
 now the honor of addressing, when the terms of 
 Science were scarcely understood among us. 
 Knowledge is not stationary : its progress is rapid, 
 or it retrogrades. It may here be emphatically said, 
 that " he who is not with us, is against us." Mental 
 exertion and mental improvement have kept pace 
 with each other, until the present state of Science 
 and Literature was perfected. 
 
 THE interior of our planet is occupied by shape- 
 less and numerous masses, lying on each other in 
 a certain order. To discover their nature, arrange- 
 ment, and relations, is the part of GEOLOGY. 
 
 The various substances scattered through these 
 beds, having in common with their matrices, cer- 
 tain laws of their own, peculiar to each species, 
 it is the business of MINERALOGY to collect and de- 
 scribe. They are bodies without motion, power 
 or life. 
 
18 
 
 The vegitable carpet of nature, which covers 
 our planet, " the grass, and herb yielding seed after 
 his kind, and the tree yielding fruit, whose seed 
 was in itself, after his kind" organised bodies, 
 with life, but no sensation, belong to the depart- 
 ment of BOTANY. 
 
 These three departments, it will be seen, de- 
 rive much assistance from CHEMISTRY, which treats 
 of those events or changes in natural bodies, which 
 are not accompanied by sensible motions. 
 
 Man, made in the image of his Creator, and to 
 whom u He gave dominion over the fish of the sea. 
 the fowl of the air, and over the cattle, over every 
 living thing that moveth upon earth, over every 
 herb, and every tree man, with all the subordi- 
 nate and^less perfect animals, is made the province 
 of ZOOLOGY. 
 
 It is my lot to treat of GEOLOGY and I propose 
 at the present time to give a rapid sketch of the 
 rise and progress of this Science, and the various 
 Theories that have been published in illustration 
 of it. This I am the more emboldened to do, be- 
 cause, as Stewart says, it is not from his own erro- 
 
19 
 
 neous hypothesis alone that the philosopher is as. 
 sisted in the investigation of truth. Similar lights 
 are often to be collected from the errors of his pre- 
 decessors : arid hence it is, that accurate histories 
 of the different Sciences may be justly ranked 
 among the most efficient means of accellerating 
 their future advacement. 
 
 It was from a view of the endless and hopeless 
 wanderings of preceding enquirers, that Bacon in- 
 terred the necessity of avoiding every beaten track : 
 and it was this which encouraged him -with a con- 
 fidence in his own powers amply justified by the 
 event to explore, and to open a new path to. the 
 
 mysteries of nature. 
 
 Inveniam viam, aut faciam. 
 
 There is no subject, says Fontenelle, on which - 
 men ever come to a reasonable opinion, till they, 
 have once exhausted all the absurd views it is* 
 possible to take of it. What follies, he adds,* 
 should we riot be repeating at this day, if we had 
 not been anticipated in so many of them by the^ 
 ancient philosophers. 
 
 Those systems, therefore, which are false, are by 
 no means to be regarded as totally useless. That 
 of Ptolemy, as Bailly observes, is founded on a 
 prejudice so natural and so unavoidable, that it. 
 
20 
 
 may be considered as a necessary step in the pro- 
 gress of astronomical Science : and if it had not 
 been proposed in ancient times, it would infallibly 
 have preceded among the moderns, the system 
 of Copernicus, and retarded the period of its dis- 
 covery. 
 
 Should any one say that, after all, our theories 
 are but hypothesis, I would beg you to call to 
 mind, that it was by the happy hypothesis of a ring 
 encircling the body of Saturn, that Huyghens ac- 
 counted in a simple and satisfactory manner for all 
 those appearances, which for years had puzzled 
 all tihe astronomers of the world. Of the accuracy 
 of this hypothesis no reasonable doubt can be en- 
 tertained, when it not only explains all known phe- 
 nomena, but enables the astronomer to predict 
 with accuracy those which are afterwards to be 
 observed. 
 
 The earliest published theory of the earth with 
 . which we are acquainted is that of Burnett.* 
 r:^<. He supposed that the primeval earth was a fluid 
 
 * mass, composed of heterogeneous materials, the 
 ' heaviest of which descended to the centre, and 
 
 there formed a hard and solid body. Around this 
 
 * " Telluris Theoria Sacra." London 1680, 
 
21 
 
 body was collected the water: and all the lighter* 
 fluids, the air particularly, ascended above the< 
 water, and encompassed the whole. Between , 
 these orbs of water and air was an oily matter, 
 upon which the impure earthy particles, blended 
 with the air, descended, and uniting with it, form- 
 ed the crust of the earth, which became habitable, 
 and was the abode of men and annimals. In this< 
 state, as its equator coincided with the plane of the- 
 ecliptic, there was no variation of season * and 
 one unbounded spring encircled all." 
 
 The surface he supposed to be smooth and uni- 
 form, without mountains, seas, or inequalities > 
 nor did it vary at all for 1 6 centuries, when the 
 heat of the sun dried the crust, and caused it to 
 crack into fissures or crevices, which eventually 
 deepened and penetrated through it These fis- 
 sures enlarged and the enclosed waters gushed 
 out with much violence, and in such quantities, as * 
 to cover the dry land, and occasion the general f 
 deluge. The water at length retired into cavities, , 
 and as these became filled, the earth appeared in 
 its most elevated parts, and formed mountains, , 
 while the lower parts remained covered by water, . 
 and formed vallies, oceans, &c. 
 4 
 
22 
 
 . 
 
 < The beauty of language in which Burnett cloth- 
 
 < ed his theory enabled him to throw a kind of spien- 
 
 * dour over his erroneous ideas, which forced them 
 .for a time into general acceptance. It has been 
 
 - asserted, I know not upon what authority, that this 
 > theory had been previously published by Francis- 
 
 co Patrizio, a professor at Rome, in a dialogue 
 called " II Lamberto." It is generally viewed as 
 
 an elegant Romance ; the product of mere imagi- 
 nation, unsupported by any observed phenomena. 
 
 ? About the same period the celebrated Leibnit/ 
 
 * published his 4i Protogoea," in which he holds that 
 ' the earth and all planets were originally fixed and 
 
 luminous stars, which for ages had blazed in the 
 
 firmament, until the combustible matter was ex- 
 
 hausted, when they lost their brilliancy, and became 
 
 opaque bodies. The fire, by fusing the earthy 
 
 < matter, vitrified it, so that the base of all things 
 belonging to the earth is glass, of which sand and 
 gravel are fragments. The other earths are a 
 
 * combination of sand with water and salts. When 
 
 this crust cooled, the aqueous particles, which 
 > had arisen afe vapour, were condensed and pre- 
 
 * cipitated, forming the ocean. These at first 
 covered all the earth, and the shells and other 
 
 marine products are proofs of the fact. 
 
23 
 
 Woodward next appears on the list of theorists.*, 
 He observed several phenomena with attention, 
 but was only partial in his observations. He notic- 
 ed marine exuviae, and supposed them left on land 
 by the subsidence of the ocean. That while the 
 waters of the deluge covered the earth, all solid 
 substances were held by them in a state of solu- 
 tion. That eventually a precipitation of all mat- 
 ters occurred in the order of their specific gravity i 
 the heaviest first, and the rest in order. That 
 consequently these strata were all parallel and 
 spherical, and encompassed entirely by the great 
 ocean. That in the course of time some power- 
 ful internal agent broke these strata universally, 
 and changed their relative positions, elevating 
 some and depressing others thus producing 
 mountains and valleys : in fine forming the earth 
 as it now exists. 
 
 It is not necessary, in the present state of this 
 science, to urge arguments against this or the pre- > 
 ceding theory. Suffice it to say, that the mere 
 existence of beds of light substances placed be- 
 neath many of greater specific gravity is at once an 
 
 i 
 objection that cannot be removed. 
 
 * Essay towards the Natural History of the Earth and terres- 
 tial bodies by John Woodward M. D. London 1702, 
 
24 
 
 The internal agent alluded to by Woodward 
 was probably the same mentioned by Dr. Hook, 
 who in his " Discourse on Earthquakes," publish- 
 ed in 1688, assumes that the bottom of the sea 
 had been elevated by these tremendous convul- 
 sions of nature, caused by subterranean fires ; and 
 he thus accounts for the existence of shells on the 
 summits of mountains. 
 
 Dr. Halley* ascribes the deluge to the shock of 
 
 * a comet, or some transient body, by which the 
 
 * polar and diurnal rotation was immediately chan- 
 
 * ged, causing thereby a great agitation in the sea. 
 Thus he accounts for all the strange varieties of 
 position we see on the surface of the earth ; as 
 high mountains standing on beds of shells that 
 were once the bottom of the ocean, &c. &c. It 
 may be observed that so violent a shock would 
 cause all fluids to run instantly to the part where 
 such a blow was given, and with such a power as 
 to carry along with it the bottom of the ocean. 
 But then the deluge must have been produced 
 very rapidly, and by no means in the gradual way 
 in which we are taught to believe that it happen- 
 
 * Phil. Trans. No. 383, 
 
25 
 
 ed, both by scripture, and the observance of phe- 
 nomena. 
 
 Catching the idea of Halley, and blending with 
 it the views of his predecessors, of Woodward 
 more particularly, Whiston erected his theory* 
 on mathematical calculation, founded on his as- 
 sumed data. He endeavours to show, that on the 
 first day of the deluge, a comet, descending in the - 
 plane of the ecliptic, towards its perihelion, pas-- 
 sed just before the earth, and, coming below the - 
 moon, caused, by its power on the tides, the el- * 
 liptic figure of the earth ; which broke, and the * 
 waters, issuing through the crevices or fissures, 
 produced the deluge, in conjunction with the rain * 
 that descended from the comet on its return. 
 
 At first, the author advanced all this by way of 
 hypothesis only, but afterwards became persua- 
 ded of the truth of a conjecture, for which there is 
 not the least semblance of foundation. 
 
 .- 
 
 In 1 740, Lazoro Moro, an Italian, is said to have 
 brought forward the idea, that not only mountains, 
 but the whole earth was raised from the bottom 
 
 * New Theory of the Earth." London 1708. 
 
! i 
 
 26 
 
 of the ocean by the power ot combustion, that 
 commenced soon after the creation. That the 
 portions of earth which now exhibit no marine 
 shells, were elevated before the fish had stocked 
 the ocean; but that afterwards shells and fish 
 were thrown up, and deposited in strata along 
 with the soil. This theory has been adopted at a 
 later period. 
 
 De la Pryme* supposes that the Antideluvian 
 world had, besides mountains, rivers, &c. an ex- 
 ternal sea, and that the falling in of immense in- 
 ternal caverns, accompanied by earthquakes, 
 swallowed up most or all of it, leaving the seas 
 only visible. From the bottom of this sea arose 
 our present earth, in the same way that some 
 islands have been swallowed down, and others 
 thrust up in their stead, even in the present day. 
 
 There are many valuable and interesting facts 
 in accordance with this theory, which has been 
 partially upheld by Mr. King, at a much later pe- 
 riod.f He accounts for the deluge wholly by 
 subterranean fires, which burst with great vio~ 
 
 * Phil. Trans. No. 266. 
 t Phil. Trans, vol. 77. 
 
27 
 
 Jence beneath the sea, and raised its bottom, so 
 as to throw its waters over the land, where they 
 have since remained ; so th?*t the dry land and 
 ocean changed places, what was covered by the 
 ocean becoming dry, and the waters resting on 
 the land. 
 
 We can scarcely believe, however, that the for- 
 mer world was completely destroyed, as is suppo- 
 sed by M. Deluc, who enlarged on this hypothe- 
 sis, since we are told that Moses took the appear- 
 ance of an olive branch to be a sign of the dimi- 
 nution of the flood. This could not have been 
 supposed to be a submarine production ; nor are 
 we at liberty to suppose it the produce of an isl- 
 and that had escaped the general inundation. 
 
 in 1746 Guettard first complied with the wishes - 
 of Lister, who, in 1 684, recommended the adop- 
 tion of geological maps. He was one of the first 
 writers who seems to have forsaken cosmogony,- 
 and applied himself to geological enquiries. He 
 possessed, for that period, much important infor- 
 mation, which led him to pretty correct conclu- * 
 sions : for instance, he formed 3 divisions of the 
 earth's surface. The first he called Schistose, 
 which embraced the primary rocks ; secondly 
 
28 
 
 -f 
 
 1 the Marls, which included the secondary, pretty 
 , generally ; and thirdly, Sand, coinciding with what 
 
 * is now termed tertiary. His views were too ex- 
 
 tensive for the state of the science at the time in 
 
 * which he lived. 
 . \ 
 
 Lehman, who directed his mind to this subject, 
 
 soon discovered and demonstrated the distinction 
 
 * between primary and secondary rocks, illustrating 
 
 his ideas by the geology of the Hartz. Like the 
 peasant of Virgil, who imagined his native hamlet 
 the miniature of imperial Rome, Lehman imagined 
 the Hartz and the Erzeberge a miniature of the 
 world. It is needless to say that they were about 
 equally correct. 
 
 Mr. Whitehurst studied diligently some parts of 
 England, for many years, and being a close ob- 
 server, he collected very many facts, whence he 
 proceeded to erect a theory,* in which the two 
 great agents are expansion and gravity : the for- 
 mer derived from internal fire, and the latter 
 from an accumulation of earthy particles. The 
 expansive force at last gaining the ascendency, 
 
 *" Inquiry into the original state and formation of the earth,'* 
 1786. 
 
29 
 
 broke through the superincumbent mass, and 
 forced up the strata in all directions. The globe 
 was afterwards broken into comparative fragments 
 by the explosion of steam, and the primitive state 
 of the earth completely changed : and even the 
 Alps, Pyrenneess and Andes thus brought from the 
 abyss. For the truth of his opinions the author 
 refers to fossils. There is some romance, and 
 much valuable information in his book. 
 
 Kirwan, an Irish philosopher of strong mind 
 and extensive erudition, not believing in the theo- 
 ries of his predecessors, turns at once to the ac- 
 count of Moses, as the only one consistent with 
 actual phenomena ; and ascribes the Deluge to a 
 supernatural cause the express intention of God 
 to punish the crimes of mankind. He says the 
 deluge was a miraculous effusion of water from 
 the clouds and from the great abyss, and which 
 was sufficient to cover the whole earth. This he 
 establishes by a reference to the laws of the New- 
 tonian theory. Having proved this fact, he pro- 
 ceeds to state that the deluge commenced in the 
 great southern ocean, below the equator, and 
 rushed thence to the northern hemisphere.* He 
 
 * Vide Trans, of Roy. Ir. Acad. vol. 6. 
 
30 
 
 brings the following arguments in support of his 
 views, viz. 
 
 1. That the southern ocean is the largest col- 
 lection of water on the globe. 
 
 2. In northern latitudes we observe the remains 
 of animals from the southern continents and ocean, 
 but in southern climates no remains of northern 
 animals of land or water. 
 
 3. The traces of a violent shock from the south 
 are still visible in many countries. 
 
 4. The shape of continents, all sharpened to 
 the south, where they are washed by the southern 
 ocean, indicate the force of the shock, which 
 mountains only could withstand ; such as the cape 
 of Good Hope cape Comorin the south point 
 of New Holland and Patagonia. 
 
 It will be observed that Kirwan endeavoured 
 to go by the Mosaic account ; which, although 
 not intended, as some writer remarks, as a geolo- 
 gical record, is still upheld by the geology of the 
 present day. 
 
 We do not believe, with some authors, that it 
 indicates presumption, to scan the works of the 
 Almighty, to attempt explanations of the deluge, 
 or any physical cause, nor to offer conjectures 
 as to the results. His power.was wonderfully and 
 
miraculously displayed in that awful catastrophe, 
 for the completion of which the operation of phy- 
 sical causes seems to have been directed, and the 
 laws of nature to have been suspended. In study- 
 ing the manner in which these changes were 
 wrought, or their ultimate effects, we see no pre- 
 sumption, no doubt of the omnipotence of the 
 Ruler, no disbelief in the wisdom of the Allwise 
 Sovereign. 
 
 As no theory that had been issued came clothed 
 in the beauties of language or boldness of concep 
 tion comparable to that of M. Buffon, so none has 
 ever been so popular, for the fund of information 
 it contains. The prominent points only can be 
 hinted at. 
 
 He supposes that the Earth and other planets 
 formed, originally, parts of that glorious orb, 
 whence we, at least, derive our light and heat : 
 and to have been detached by an oblique stroke 
 of a comet. These portions of igneous matter, 
 forced thus from the Sun, assumed a globular 
 shape by the attraction of cohesion, and receded 
 to such a distance as to allow them to gain an 
 eliptical motion round the parent Sun, where they 
 are now retained by the conjoined effect of cen- 
 
32 
 
 tripetal and centrilugal forces. By the rotary 
 ^notion, and the fluidity of matter, the earth gra- 
 dually became an oblate spheriod. It eventually 
 ^cooled, and the aqueous atmosphere condensing 
 *by degrees, descended upon the surface in form 
 >of water. This water deposited sulpherous, sa- 
 line, and other matters, which entering into fis- 
 sures, &c. 5 formed metallic veins and minerals : 
 *arid part resting on the surface, produced mould. 
 'The internal part, he says, were, and still are 
 
 vitrified : the upper surface, being pumice arid 
 
 scoriae, were acted on by the water and other 
 
 agents, and produced clays and soil. In this state 
 'the tides and the winds and the heat of the sun 
 
 began to produce strong effects. The diurnal 
 
 motion of the earth, arid the power of the tides. 
 i elevated the waters around the Equator, and car- 
 ried there, from higher latitudes, great quantities 
 
 of slime, sand, clay, $*c., thus elevating the equa- 
 torial, and depressing the polar regions. Thus, 
 'he says, we observe the highest mountains within 
 -the tropics, and there the irregularities of surface 
 -generally are greater than at the poles. The ac- 
 tion of water in the scoriae, produced excavations 
 in some places, and elevations in others, which 
 in course of time formed islands and continents. 
 
33 
 
 The destruction of mountains, and the formation . 
 of new islands, with all the various positions of- 
 strata, so unaccountable by all other theories, he 
 endeavours to reconcile by the chaotic confusion 
 thus produced. 
 
 The bottom of the sea, he says, resembles, in its 
 regularity, all the varieties of inequality, of hill 
 and dale, earth and rock, that we observe on dry 
 land. Its plants and shrubs have a similar regular 
 distribution. As we find under the equator the 
 highest mountains, so there do we find the 
 deepest seas. Incontrovertible facts, he thinks, 
 prove, that as the dry and habitable portion of 
 the earth has been once for a long period under 
 water, so similar changes are now going on at the 
 bottom of the ocean, which will eventually be- 
 come dry land: but not in an immense period, 
 since the operation of like causes do not produce 
 like effects in the same time now as formerly. 
 
 All continents and islands have their mountains * 
 in the centre, dividing them longitudinally. From * 
 these the rivers run perpendicularly to the ocean, 
 in which they empty, wearing away mountains,* 
 producing vallies, and making deposits at their- 
 mouths, which are carried into the ocean, to form* 
 new beds, new islands, and new continents : and 
 
:M 
 
 eventually to restore to the dominion of ocean 
 i the realms which are now beyond its waters and 
 
 whose rocky barriers and broken coasts seem to 
 hold the language of the flatterers of Canute 
 " thus far shalt thou come, and no farther." 
 
 In noticing this theory, I must be allowed 
 
 to say, that it was only about the time of its pub- 
 lication, that Geology first claimed the rank of a 
 science. Before this period, scarcely an accurate 
 idea had been formed on the subject. The few 
 
 rays of light were scattered, until an unexpected 
 
 nucleus attracted the wandering atoms, and drew 
 
 'them together. The brilliant genius of Buffon 
 
 'diffused a radiance on philosophical enquiries. 
 
 It wasted itself in unprofitable theories, but threw 
 
 a distant light upon the practical enquirer. This 
 ;is the only subject on which the splendid genius 
 
 of the naturalist shed no immediate light : smaller 
 stars, however, were rendered perceptible by his 
 reflected rays. 
 
 All these theories are vague, and insufficient to 
 account for existing facts; besides that they par- 
 take too much of the ancient cosmogony for the 
 present day. 
 
 There are but two other theories of consequence: 
 and these we shall but slightly touch upon, intend- 
 ing in the course of our duties to refer to them sepa- 
 
35 
 
 rately, and view their opposing principles. I shall 
 have been anticipated by many of you when I 
 mention that these are the celebrated theories of 
 Dr. Hutton of Edinburgh, and of Prof. Werner of 
 Freyburg. 
 
 Dr. Hutton published his theory in 1788. 
 
 He considers the Earth as a mere machine 
 describes its mechanism and enumerates the 
 powers by which motion is produced, and activity 
 communicated to it. These are the projectile 
 power, gravitation, the influence of light, heat, 
 cold, condensation, electricity, and magnetism. 
 
 Observing that a solid body of land could not 
 answer the purposes of an inhabitable world with- 
 out a soil suited for vegitation, he says that this 
 soil is formed merely by the decomposition of 
 the solid earth. The surface inhabited by man, 
 and covered by plants and animals is made by 
 Nature to decay that the interior constantly fur- 
 nihes soil which is as constantly washed away by 
 the continual action of water running from the 
 mountains to the ocean : that thus heights are 
 levelled, fertile plains formed from the disintegra- 
 tion of mountains and rocks, and the materials 
 carried on to the abyss of ocean. This soil is 
 constantly formed and removed, and thus the land 
 
36 
 
 tending constantly to destruction. To counteract 
 this Dr. H. supposes the constitution of the globe 
 to possess a reproductive operation, by which this 
 ruined and decayed world becomes again repair- 
 ed ; and that the apparent destruction of the earth's 
 surface is in fact the real cause of its renovation- 
 While this change is going on, new strata become 
 consolidated by internal heat : all solid land is 
 formed at the bottom of the sea, and elevated by 
 fire, inaccessible to be sure to human observation, 
 but still existing and operating. Simple fusion, 
 then, is considered as giving hardness and solidity 
 to the different strata that have been condensed 
 by means of it. According to this Theory the se- 
 condary and newer rocks were deposited at the 
 bottom of the ocean, in consequence of operations 
 similar to those now in action, and the primary 
 were formed beneath, by internal fire. All mar- 
 bles, limestones, &c, are composed of the calca- 
 reous matter of marine animals. 
 
 In this theory there is a happy union of the 
 Agency of both fire and water ; the one collecting 
 and depositing, the other consolidating and ele- 
 vating. 
 
 This system is in unison with many facts as seen 
 in Scotland where it originated. It has been ably 
 
37 
 
 supported by the elegant illustrations of Professor 
 Play fair. That classic scholar could see the ordina- 
 ry operations of nature producing Geological phe- 
 nomena, through an infinite succession of ages' 
 without beginning and without end. The subject 
 has been rendered interesting, independant of its 
 author, by these illustrations, which are said to 
 display advantageously its principles, argue forci- 
 bly in its favor, ingeniously combat the objections^ 
 and apparently establish its own conclusions. 
 
 This book continues to be the text book of the 
 best English Geologists. 
 
 It will be remarked that this theory embraces 
 many of the points held out by the philosophy of 
 Aristotle, which, as formerly remarked, secured 
 to itself, by its doctrine of the eternity of the world, 
 the severest censures of the Fathers of the cl\ris- 
 tian church. 
 
 It was about this time that Saussure visited and 
 studied the Alps, whence he drew conclusions the' 
 most important to Geology. While he was thus 
 engaged, Pallas was traversing the Russian em-' 
 pire, and, with the zeal of a master, accumulating* 
 facts for the establishment of tjie science. 
 
 6 
 
38 
 
 Werner, a name almost revered in Germany, now 
 appeared on the list of Geologists. As he pub- 
 lished but little himself, his intrinsic merits can 
 
 , 
 
 never be properly estimated. It is to be regretted 
 that his apathy prevented him from publishing, 
 His antipathy to the mechanical part of writing 
 was so excessive as to be amusing. Nothing 
 could finally induce to write a line; and to avoid 
 reproaching himself with want of politeness, he 
 at last would not open the letters addressed to 
 him. 
 
 A certain author who wished to consult many 
 philosophers respecting a voluminous work, circu- 
 lated his manuscript and it was lost; after a thousand 
 researches, it was disinterred at last, from among 
 an hundred others, in possession of Werner. When 
 the French Academy placed him among its eight 
 foreign associates, an honor coveted by the most 
 illustrious philosophers of Europe, he never opened 
 his letters, and became acquainted with his hon- 
 ors through an Almanack. And to crown all, an 
 express which his sister had sent.tohim from Dres- 
 den, waited two months, at an inn, at his expense, 
 waiting his simple signature to some very pressing 
 family concerns. He had sent his " System" to 
 fhe press, but could never endure the fatigue of 
 
39 
 
 correcting the first proof sheet. We know it, 
 therefore, only as promulgated by his pupils ; who 
 looked upon him as the genius of his age, and 
 blindly worshipped at his feet. They supposed 
 that his ideas formed at once a mature system, el- 
 egant and perfect, they termed it geognosie, and 
 inscribed on it the name of Werner. To this 
 merit he was not entitled. He had a strong mind, 
 which was divided, and gave its whole strength to ' 
 minerals and systems. Method was his hobby. 
 He was fond of dividing and classifying, and latterly 
 bought books, not to study, but to arrange them 
 in a certain order in his Library, He is said to 
 have debated alike on the order of his dinner table 
 and the arrangement of his cabinet, and even 
 traced the military art by the laws of geology.' 
 ^ A man," said he, " who wishes to become a great 
 General should begin his education by studying 
 Oryctognosy and Geognosy, at Freyburg." It waa 
 his love of system and division that induced him 
 to add to the primary and secondary, the interme- 
 diate transition, which has been likened to the in- 
 creasing of primary colors by the addition of mix-, 
 ed tints. He, multiplied divisions, but he did not' 
 strengthen them. His great error was in suppo- 
 sing that Saxony and Bohemia were the world in 
 
 
40 
 
 miniature. Like Lehman, he supposed that what 
 he had seen was all the world afforded : and that 
 he had sufficient data in his own country w r hence to 
 draw conclusions as to the universal structure of the 
 world. None but his most attached pupils now 
 uphold his theories, which he carried beyond the 
 bounds of philosophy. His ardent zeal, however, 
 - diffused itself among his adherents, and he may 
 justly be said to have done more than any other 
 man for the advancement of Geology. 
 
 We have been detained, however, too long by the 
 man, from his works. He threw aside hypothesis, 
 and drew his arguments from facts. 
 
 His first proposition was that the Earth, to some 
 depth, was originally fluid not from fusion by 
 heat, but from aqueous solution. These outlines 
 are these : 
 
 1. The surface of the globe was originally soft 
 or fluid, as inferred from its present shape, and 
 geological phenomena. 
 
 2. That for centuries after its creation the earth 
 contained in its inner parts immense empty ca- 
 verns, but sufficiently solid to bear the superin- 
 cumbent mass. 
 
 3. The materials composing the earth were at 
 one period dissolved, and held in solution by wa- 
 
41 
 
 ter, whence they have been consolidated and pre- 
 cipitated, partly by crystalization and partly by 
 mechanical deposition ; granite first, and the oth- 
 er primary rocks in order, principally by chemical 
 precipitation. 
 
 4. From this date the waters rapidly subsid- 
 ed, retiring into the cavities of the earth.' During 
 this period other strata, the oldest secondary, (or 
 transition J were deposited. 
 
 5. The further subsidence of the waters occa- 
 sioned, by mechanical action, a partial disintegra- 
 tion, which furnished materials to unite with those 
 still held in solution, which were then precipitated 
 and formed the secondary horrizontal beds, abun- 
 dant in organic remains. 
 
 6. During the gradual diminution of the waters, 
 and the consequent hardening of the strata, rent? 
 and crevices were formed, into which the waters 
 entered, still holding in solution metals, &c. &e. 
 whence arise metallic veins and beds of metals. 
 
 7. That volcanoes, and depositions from water 
 are still producing changes on the earth's surface. 
 
 From the time of Pallas, Saussure, Button and 
 Werner, the new science, which had lately arisen 
 under the proud tittle of the theory of the earth- 
 attracted the notice, it merited. Celebrated men 
 
 
42 
 
 became its pupils, and we find Humboldt, Cuvier, 
 Daubuisson, Brongniart, Van Buch, Brochant, 
 Brocchi arid Maclure, with many others, giving 
 their time to perfecting it : each adding his obser- 
 vations to the scale of one of the great masters, 
 whence have been derived the absurd titles of 
 Wernerian and Huttonian, or Neptunian and 'Plu- 
 tonic Theories. The one attributing most geologi- 
 cal phenomena to itfgeRious, the other to aqueous 
 origin. Both are imperfect. Future observations 
 will add valuable facts, and perhaps accumulated 
 evidence will weigh in favour of the aqueous ori- 
 gin of most rocks. 
 
 Whatever may appear from a transcient glance, 
 a complete examination of the opposing theories 
 cannot leave the mind biassed much in favour of 
 either. To the Huttonian theory, says Dr. Murray, 
 its most violent opponent, belongs the praise of 
 novelty, boldness of conception, and extent of 
 views. Its author has aspired not merely to ac- 
 count for the present appearances of the earth, but 
 to trace a system, in which the formation of suc- 
 cessive worlds is developed : he has sought to ex- 
 tend that order and arrangement, that principle ot 
 balance and restoration, observed in all the de- 
 
 
43 
 
 partments of nature, to the constitution of the globe 
 itself, and he has succeeded in drawing an outline 
 which gratifies the imagination with the semblance 
 of grandeur and design. 
 
 An enumeration of the arguments in favour of 
 this theory cannot be necessary to you. Suffice it 
 to acknowledge that the relative position of mine- v 
 ral masses, their constituent parts, and the peculi-' 
 arity of fossils render iriadmissable the idea of a * 
 central fire, existing without an assignable cause f ' 
 from eternity, and producing effects by no means' 
 commensurate with its power. We are not how- ' 
 ever to underate the agency of subterranean com- 
 bustion : The known existence of nearly two 
 hundred volcanic openings is sufficient proof of 
 the extent of internal fires : and the vast distance at 
 which the shocks they occasion have been sensibly 
 felt, give some idea of the extent of their force, 
 which even an intervening ocean cannot restrain. 
 
 The opposing theory, to which the name of' 
 Werner has been improperly attached, forms a. 
 simple contrast to'improbable hypothesis. That 1 
 the surface of the earth has been arranged by 
 water, is proved by a knowledge of geological facts, 
 In appealing to proofs from induction, we find ac- 
 tual phenomena in accordance with principles.. 
 
44 
 
 Perfection is not attainable in all things : while 
 
 any science therefore remains in a state of imper- 
 
 fection, deficiencies must be discovered in the ap- 
 
 , plication of principles established by induction 
 
 only. Such is the case with this theory, yet it of- 
 
 'fers no inconsistencies, contradicts no facts. It 
 
 i is a series of inductions, more or less perfect, re- 
 
 1 ferred to a common principle, and occasionally 
 
 -> connected by a moderate and rational hypothesis. 
 
 / It will have been noticed by all of you that no 
 attempt has been made to explain the present ap- 
 pearances of the earth's surface without allusion to 
 a period when it was inundated. No theorist has 
 advanced an opinion in which such an event does 
 not form one of the most prominent features. It 
 becomes necessary, therefore, for one moment, to 
 f turn our attention to that epoch, one of the most 
 remarkable in chronology. 
 
 Previous to the general deluge, we find by sacred 
 and profane history, that there were several great 
 floods : of which that happening in Greece, during 
 the reign of Deucalion, is one of the most conspi- 
 cuous. It is said to have occurred 1 529 years B. 
 C. being the third year before the Israelites left 
 Egypt (or 1503 according to Blairs chronology.) 
 
 is flood inundated all Thessally. 
 
 
45 
 
 296 years before this flood, viz. 1020 years'toefore * 
 the 1st Olympiad, and 1796 years B. d occurr- - 
 ed the deluge of Ogyges, which ravaged Attica. 
 
 These floods have occasionally been confound- 
 ed with that of Noah. 
 
 There are other floods on record, which may be 
 barely named The deluge in Syria which in 1095 
 A. D. drowned vast numbers of people that which' 
 in 1164 deluged Friesland and that which 1218^ 
 deluged the same country and destroyed 100.000* 
 men. 
 
 The Netherlands and Brabant have been seve- > 
 ral times inundated and their whole surface mate- 
 rially changed. 
 
 The deluge, however, to which geologists allude, ) 
 is distinguished as the universal or Noah's flood 
 and is recorded in scripture (Gen. 6 and 7th ch.) 
 as sent by way of punishment for the vices and cor- j 
 ruption of that age. 
 
 The period of its occurrence is stated by the ; 
 best chronologers, to have been 1656 years after! 
 the creation, or 2348 years B. C. and 4173 from 
 the present year. On the 10th day of the second; 
 month, which answers to Sunday, Nov. 30th, Noah 
 and his family entered the Ark. On Sunday Dec. 
 7 
 
 
46 
 
 7th, the rain commenced, and continued for forty 
 days. On Wednesday May 6th (2348 B. C.) the 
 ark rested on mount Arravat. The tops of the 
 mountains became visible on Sunday, July 19th, 
 and on Friday, Dec. 18th, Noah and family left the 
 ark, and built an altar to God. 
 
 One hundred and fifty days therefore is the 
 period it lasted and during this time many of 
 those changes took place which it is in some mea- 
 sure our object to account for. 
 
 It is a remarkable fact that this event is pre- 
 served in the memory of all nations. In our country, 
 as well as in Africa, Asia, and Europe. 
 
 We are indeed told that the Gentoo traditions, 
 
 neither written nor oral, make any mention of it, 
 
 and that the Bramins assert it never took place in 
 
 ' Hindoostan. Were this true, it would necessarily 
 
 * excite astonishment, since traditions of it have 
 been traced in every quarter; not only among the 
 
 'Romans, Greeks, Egyptians, Babylonians, Persians 
 4 and Scythians, but among our own Iroquois, among 
 the Mexicans, Brazilians and Persians. 
 
 But Sir Win. Jones asserts that traditions con- 
 
 * cerning a deluge do exist from Hisdoostan, and 
 4 that their oldest mythological works preserved an 
 
 * account very similar to that of Moses. 
 
47 
 
 It is asserted that some traveller, interrogating 
 the inhabitants of Otaheite as to their origin, re- 
 ceived for answer, that a long time ago, the su- 
 preme God, being angry, dragged the earth through 
 the sea, and their island being broken off, was 
 alone preserved. 
 
 I am not here however, to defend or uphold the 
 accounts related in the Bible. It is a history how- 
 ever, which does derive support from Geology. 
 
 Although no geological theory has been broach- 
 ed on this side of the Atlantic, it is with much plea- 
 sure that I am enabled to turn our thoughts home- 
 ward, from the splendid constellation of European < 
 science, and survey the rapid strides of this 1 
 branch in our own country. Twenty years ago 
 Geology was known here by name only. It was 
 about that period that the late Dr. Bruce returned 
 from Europe with a splendid collection of mine- 
 rals. His zeal and attainments, with the conjoin- 
 ed efforts of Col. Gibbs, gave an eclat tothe study 
 of mineralogy, appropriately termed the alpha- 
 bet of Geology, which has produced the most 
 beneficial effects. It is needless to enumerate the 
 long list of those who have since successfully pro- 
 moted the interests and diffused the knowledge 
 of mineralogy, serving as the foundation of geology. 
 
 
48 
 
 * It is not more than fifteen years since we had 
 vthe first intimation through the press, that any oi' 
 -our citizens had observed the geological pheno- 
 imena of our country. Dr. Mitchill and Dr. 
 tArkerly were among the foremost to enlighten us 
 
 i on the subject, in the first purely scientific jour- 
 nal established in our country.* Since then, we 
 have been annually enriched by the exertions of 
 our friends. No great standard work has yet 
 
 * been given on the geology of America ; but the 
 partial labours of individuals will soon afford am- 
 ple materials for filling up the outlines now so 
 'well known, and which are more distinctly mark- 
 *ed than in any other country. 
 
 , The observations attached to the American 
 , edition of Cuvier's theory of the earth, and the 
 . numerous notices of the learned annotator in vari- 
 
 * ous periodicals have thrown abroad mucli infor- 
 mation on the formation of North America. 
 
 * The Essays of the indefatigable President of the 
 
 * Academy of Natural Sciences, at Philadelphia, 
 have done much to advance this Science, and 
 'many of the members of that highly respectable 
 
 * society are zealously engaged in the same cause. 
 
 erican Mineralogical Journal. 
 
 
49 
 
 Mr. Hayden has published a vast accumulation " 
 of facts to prove that the whole region skirting the 
 the Atlantic ocean is the result of the operation of 
 Currents. He attaches much importance to this 
 region, and has partially marked out the most in-' 
 teresting formation that we possess : I mean the 
 Tertiary. The author has evinced a knowledge, 
 of his subject which it would be well for those to 
 possess who oppose his views. 
 
 Dr. Akerly's Geology of the Hudson has been 
 long before the public. 
 
 Mr. Pierce has described part of New Jersey 
 and the Catskill mountains. 
 
 To Mr. Hitchcock we owe a minute and inter-' 
 teresting sketch of the Geology and Mineralogy of 1 
 the Connecticut river. 
 
 The Exploring Expedition sent by Government, 
 under command of Major Long, to the Rocky 
 Mountains, has greatly added to our knowledge of 1 
 the secondary region to the west and north. 
 
 The gentlemen engaged in establishing the 
 boundary line under the 6th and 7th articles of the 
 Treaty of Ghent have afforded new information 
 
50 
 
 concerning the country about the great Lakes and 
 to the north west. Major Delafi eld, agent of the 
 "U. States, under those articles, and Dr. Bigsby of 
 the British Medical Staff, attached to the com- 
 
 mission, have laid us under many obligations by 
 their very valuable contributions to our knowledge 
 
 * of that interesting region. 
 
 Mr. Schoolcraft is now engaged in the publica- 
 tion of a work from which we may expect to de- 
 rive much valuable information relative to the 
 geological structure of our western country. 
 
 . To the Hon. Maj. Gen. Van Rensselaer, whose 
 enlighted mind, and liberal views interest him in 
 
 all branches of knowledge, we owe Geological and 
 . Agricultural Surveys of the district adjoining the 
 -Erie Canal and of the counties of Albany and 
 'Rensselaer. 
 
 Individual observations on particular regions are 
 thus connecting links for the formation of one 
 grand chain, which will eventually embrace all the 
 strata, beds, veins, and minerals of our continent 
 
 The bold outline of our primary range of coun- 
 try first attracted the notice of our geologists. 
 The secondary has been explored in the grand 
 with tolerable accuracy. 
 
 
 
51 
 
 The alluvial has received a portion of attention ; 
 indeed under this term has been included until of 
 late, the vast tertiary formation situate between 
 the alleganies and the atlantic. 
 
 The vast number of beautiful fossils that we are 
 constantly receiving from our secondary and ter- 
 tiary formations go far towards proving that many 
 of our rocks are precisely of similiar formation with 
 many of those of Europe, and afford new proofs of 
 the value of these remains as geological characters. 
 
 Allow me, for one moment, in concluding this 
 sketch of Theories, to dra\v your attention to the 
 striking similarity of the Records of Sacred His- 
 tory, and the phenomena of Geology. Upon a 
 comparison, I think you will coincide with me in 
 the assertion, that the Mosaic account of the struc- 
 ture of our globe is fully corroborated by the 
 evidence afforded by the Science with which we 
 are now engaged. 
 
 The account in Genesis maybe summed up hr 
 three articles. 
 
 1st. That God was the original creator of all- 
 things. 
 
 2d. That at the foundation of the globe we in- 
 habit, the whole of its materials were in a state of- 
 chaos and confusion. 
 
52 
 
 3. That at a period not exceeding 5000 years, 
 (according to both Septuagint and Hebrew Chroni- 
 
 - cle) the whole earth underwent a mighty catastro- 
 phe, in which it was completely inundated by the 
 
 immediate agency of the Deity, and all its inhabi- 
 tants destroyed, except the remnant miraculously 
 -preserved to continue the species. If to these 
 
 - great outlines of the sacred historian, we add that 
 the materials of the globe were in a fluid state pre- 
 vious to its organization and that its organization 
 was gradual, we embrace all the important points 
 comprised in the Records and all that the most 
 
 zealous believer in inspiration is bound to main- 
 tain. 
 
 Let us now look to the phenomena of Geology, 
 and see the conclusions drawn from their study 
 and examination. These conclusions, condensed 
 from the observations of Cuvier, the most acurate 
 -naturalist of the present day, may also be com- 
 < prised under three heads. 
 
 . 1st. That the sea has atone period or other not 
 
 only covered all our plains, but remained therefor 
 a long time and in a state of tranquility. 
 
 2d. That there has been at least one change in 
 
 * the basin of the sea which preceded ours : it has 
 ' experienced at least one revolution. 
 
53 
 
 3d. That the particular portions of the earth, 
 which the sea has abandoned by its last retreat, had 
 been laid dry once before, and had at that time pro- 
 duced quadrupeds, birds, plants, and all kinds of ' 
 terrestial productions : it had been inundated by , 
 the sea, which has since retired from it, and left it 
 to the possession of its own proper inhabitants. 
 
 Thus we see that the accounts of Moses, and 
 the results attained by Geology, or the study of the 
 structure of the world, coincide, and derive light 
 and support from each other. 
 
 1. The prevalence of the waters at the period 
 of the Creation described by Moses : 
 
 2. The separation of the land from the water, 
 producing a revolution in the basin of the sea : 
 
 3. The irruption of the sea over the continent, 
 are satisfactory coincidences between the Sacred 
 Historian and the Geologist. 
 

 LECTURE II. 
 
 Objects of Geology its utility to the Farmer, Mi- 
 ner, and Architect. Position of Rocks division of 
 them into classes. Observations on the Primary Rocks 
 on the Transition Secondary Tertiary and diluvial. 
 Organic Remains. Divisions of the Earth's Surface 
 Bottom of the Sea Dry Land Low Land Alpine 
 Land. J\lountain Groups and Chains. Observations 
 on the Position and Declivities of Mountains. Vatties. 
 
 From the view of Theories which I have offered 
 ito you in the last lecture, it will be seen that Ge- 
 |ology is the science purporting to illustrate the 
 Structure, relative position, and mode of formation 
 of the different substances composing the crust of 
 the Earth. It aspires to record events of that pe- 
 jriod of time, when not only the Earth, but the 
 whole planetary system was uncreated. It is by 
 induction only, however, that we explain phenome- 
 na, and assign causes to effects that have operated 
 in former times, and thence down to the present 
 day, through a succession of ages. 
 
.05 
 
 By induction is to be understood that process, 
 by which, upon comparing a number of cases, 
 agreeing in some circumstances, but differing in 
 others, and all attended with the same result, a Phi- 
 losopher connects, as a general law of Nature, (he 
 event with its physical cause. According to Bacon 
 "Inductio, quae ad inventionem et demonstrationem 
 scientiarum et artium erit utilis, naturam separare 
 debet, per rejectiones et exclusiones debitas," &c. 
 &c. Nov. Org. Lib. 1, Aph. 106. 
 
 To the admirers of Nature's works, Geology of- 
 fers new treasures of enjoyment, arid viewing the 
 sublime or beautiful scenery which surrounds him, 
 he has greater cause than ever for admiration, in 
 its powers of adaptation to the purposes of life ; 
 and exclaims with the melancholy, but pious 
 Young 
 
 An humble, pure, and heavenly minded heart 
 Is here inspired. 
 
 In referring to the phenomena of Geology, a 
 pure and classic writer has observed, that, few 
 questions are more calculated to excite the specu- 
 lative enquirer, or more fascinating from the 
 grandeur and novelty of the objects it brings be- 
 fore the mind. Nor can it be said to satisfy noth- 
 ing but a vain curiosity. The maxim is too well 
 established by the history of science to require 
 
56 
 
 proof or illustration, that the consequences which 
 may result from any physical discovery can never 
 be foreseen, and that no investigation can he 
 deemed unprofitable which may add to our know- 
 ledge of nature. A perfect Theory of the Earth, 
 were it established, would undoubtedly admit of 
 the most important applications, and a succession 
 of Theoretical discussions may not less contribute 
 to its attainment, than the accumulation of facts. 
 With these last it is more particularly our business 
 to be now engaged. 
 
 The utility of Geology is evinced by the zeal> 
 with which, in different parts of the world, it is 
 cultivated. And independent of the gratification 
 we always feel in being able to lay open to ob- 
 servation the Laws of Nature, that tend only to 
 inspire feelings of reverence and love to the great 
 and good Being whose wisdom is so conspicuous to 
 all, it is of the greatest practical importance to 
 the Miner, to the Farmer, and to the Architect. 
 
 .- To miners, and consequently to all those man- 
 r vifactures connected with the metals and treasures 
 v of the earth, it offers the surest means of success, 
 * by teaching in what rock or position we may ex- 
 
 : ' 
 
 
. 
 
 57 
 
 pect to find mineral treasures : that some rocks * 
 never contain them : that metallic substances run 
 generally in veins, and are found only in certain . 
 rocks, and in connection with certain other sub- * 
 stances. That coal, for instance, is never found - 
 in the primary rocks, nor in the tertiary, nor in- 
 the alluvial formations consequently, it is found * 
 only the secondary : and a knowledge of this 
 class of formations teaches us, that it is found on- 
 ly in the older of its series ; as with sandstone, 
 shale, (argillaceous slate) marl, argillaceous * 
 porphyry argillaceous iron ore ; and of these, * 
 most commonly with sandstone, shale, and pud- " 
 dingstone. 
 
 It teaches the agriculturalist whence to procure 
 substances to benefit his land, and to render it 
 fertile ; and leads him to choose such portions of 
 soil as by their composition and associations are " 
 best fitted for his purpose. 
 
 The subject of Mineral Manures has not receiv- 
 ed in this country the attention it merits. The 
 practical utility and value of this knowledge has 
 been fully evinced in New-Jersey : in illustration 
 of which I may mention a fact, which came par- 
 tially within my own observation. 
 
 
58 
 
 A few years since, the inhabitants of a small 
 village in Monmouth county, finding that all the 
 labour they could bestow upon their lands did 
 not render them * productive, and that they 
 could not force " the churlish soil to yield them 
 bread," resolved to desert the place of their na- 
 tivity, and seek a more friendly soil. The dis- 
 covery of marie, however, having been made, and 
 mentioned to them, they resolved to give it a trial, 
 and found it to succeed to admiration, and far be- 
 yond their hopes. Land that for nearly a century 
 had been considered as without value, was soon 
 converted into fertile fields, yielding abundant and 
 valuable crops. The consequence has been, that 
 the same labour which would scarcely afford sub- 
 sistence, now offers wealth and contentment. 
 The lands of the county are said to be worth at 
 least one million of dollars more since the disco- 
 very and use of this mineral substance. 
 
 The useful operation of Draining Land, another 
 subject of vast importance to the agriculturalist, 
 depends in a great measure upon a proper know- 
 lege of the structure of the Earth, and of the vari- 
 ous strata of which it is composed ; as well as their 
 relative degrees of porosity, or capability of ad- 
 mitting or rejecting the passage of water through 
 
 
59 
 
 them : and likewise the modes in which bodies of 
 water are formed, and conducted from different 
 elevations. 
 
 The same observations may be applied to 
 Springs, as it is owing to these chiefly that Drain- 
 ing becomes necessary : and as they consist simply 
 of water gliding along between inclined strata, 
 it is evident, that a knowledge of these strata is 
 essential to the detection of Springs, and their con- 
 version to useful and ornamental purposes. Thus 
 in some situations, Springs are only found on one 
 side of a mountain in other eminences occasion- 
 ally on all sides of them. In searching for Springs, 
 therefore, is it necessary to examine the strata of 
 the country. It is only by this knowledge that we 
 can explain the phenomena, of the different kinds 
 of Springs: as the perennial, that flows constant- 
 ly : the temporary, flowing only at particular sea- 
 sons; the intermittent, that flows and stops, then 
 and stops flows again; the reciprocating spring, 
 that rises and falls, or ebbs and flows at regular in- 
 tervals called also ebbing and flowing wells ; of 
 oozing and weeping Springs and many others of 
 this kind. 
 
 To the Architect, and to the citizen who em- 
 ploys him for the purposes of ornament or comfort, 
 
 
60 
 
 this study teaches truths that are but too ol'ten for- 
 gotten. The want of attention to this subject in pub- 
 lic works, is a matter always of deep regret. Monu- 
 ments of Art monuments intended to commemo- 
 rate a great or heroic action, should be so con- 
 structed as to remain for ages the admiration of 
 mankind : yet we often find them erected of per- 
 ishable materials, and scarcely surviving the artists 
 who constructed them. 
 
 It would not be in place to advert here to the 
 origin of the use of stone in architecture or in sta- 
 tuary, nor to point out the most appropriate for 
 those purposes. These will be hinted at in our 
 description of Rocks, should we have time. I must 
 observe, however, that ' in the erection of both 
 public and private buildings we are lamentably de- 
 ficient in respect to beauty, durability, or the inter- 
 est of prosperity. We take our materials because 
 they are near at hand, because they are cheap, 
 and because others take the same, in preference 
 to searching out others, which although at a dis- 
 tance and more expensive, are more durable and 
 much more beautiful : which has given rise to the 
 observation, that the ancients built, in their full- 
 ness of heart, for posterity ; but that we are more 
 selfish, and build only for ourselves. 
 
6] 
 
 Such was the care of the ancients to procure 
 lasting materials for their public works, that had it 
 not been for the unrelenting cupidity, and more 
 than gothic barbarism of modern collectors, more 
 unrelenting than the destroying tooth of time, or 
 the destruction of war, 
 
 To rive what Goth, and Turk, and Time had spared, 
 What envious Eld forebore, and Tyrants left to stand, 
 
 many Grecian and Roman temples would have re- 
 mained perfect to the present day, not effected by 
 the war of elements for more than 2000 years. 
 
 Scarcely one building in Europe or America, of 
 modern construction, at the end of 1000 years 
 will have one stone left upon another stone, to de- 
 note the place where it stood. And the most 
 splendid works of modern architecture are even 
 now hastening to decay, from want of attention to 
 this subject. The elegant chapel of Henry VII. 
 near Westminster Hall, in London, is an illustra- 
 tion of this sad truth. In the short space of 300 
 years, all the beautiful ornament with which the 
 exterior was so lavishly adorned, has crumbled 
 away. I saw the workmen, a few years since, in- 
 serting new stones on which the sculpture was 
 copied, in place of those that were decayed ; but 
 
 from the same want of judgment in the choice &f 
 9 
 
62 
 
 materials, the present casing will not last longer 
 than the original. 
 
 In our various excursions in the country, most, 
 if not all of us, have observed, no doubt, that we 
 seldom travel far over the same kind of rock ; but 
 that they usually alternate or vary. 
 
 The great rock masses or beds, are very sel- 
 dom exactly horizontal, and still less often do we 
 find them perpendicular : they all have some in- 
 clination to the horizon thus 
 
 The angle with the horizon is called the Dig and 
 the edge that appear on the surface is called the 
 Basset, or cropping out.. 
 
 Upon an attentive examination of these strata 
 we perceive that their position, their ingredients, 
 and their associations vary materally from each 
 other ; that each has certain peculiarities of its own 
 but that several of them have many laws in com- 
 
 
63 
 
 mon with others, their neighbours. This has led 
 to a division and classification of rocks, which has 
 been variously altered and modified. 
 
 Lehman, as before stated, first divided the rocks 
 into the older or primitive, which contain no or- 
 ganic remains, or petrifactions, as they are called, 
 and into the secondary, in which he included all 
 other rocks. A very judicious division, for the 
 period in which it was made. 
 
 To these, as before remarked, Werner added the 
 Transition, (or those which contain only a few or- 
 ganic remains) and called those secondary rocks 
 containing many remains Flcetz, because he thought 
 them horizontal. His pupils again divided this 
 class and made the later rocks into a new class, 
 which they called Newest Floetz embracing many 
 that are now termed Tertiary. 
 
 Another classification has been lately proposed 
 in that excellent work " on the Geology of Eng- 
 and and Wales," by Messrs. Conybeare and Phil- 
 lips, viz. : 
 
 
64 
 
 Character. 
 
 roposed Names. 
 
 Wernerian 
 Names. 
 
 Other Names. 
 
 1. Formations (chiefly 
 of Sand and Clay) 
 above chalk. 
 
 Superior Order. 
 
 Newest Flcetz. 
 
 Tertiary Class. 
 
 2. Comprising 
 a. Chalk, 
 b. Sands and Clays, 
 beneath, the Chalk, 
 c. Calcareous Free- 
 stones (oolites) & 
 Argillaceous beds. 
 a. New Red Sand- 
 stone, Conglomer- 
 ate and Magnesian 
 Limestone. 
 
 Supermedial 
 Order. 
 
 Flcetz. 
 
 Secondary 
 Class. 
 
 3. Carboniferous Rocks 
 comprising 
 a. Coal Measures, 
 b. Carboniferous 
 Limestone, 
 c. Old Red Sand 
 Stone. 
 
 Medial Order. 
 
 Sometimes referred to the 
 preceding, sometimes to the 
 succeeding class by writers of 
 these schools very often the 
 coal measures are referred to 
 the former ; the subjacent lime- 
 stones & sandstones to the latter 
 
 4. Roojing Slate, &c. 
 &c. &c. 
 
 Sub me dial 
 Order. 
 
 Transition 
 Class. 
 
 Intermediate 
 Class. 
 
 5. -Mica Slate. 
 G neiss and Granite. 
 
 Inferior Order. 
 
 Primitive 
 Class. 
 
 Primary 
 Class. 
 
 These divisions are the same with those gene- 
 rally recognised hy geological writers, excepting 
 that the 3d is by some combined with the second 
 by others with the fourth, but all geological anal- 
 ogies and relations are grossly violated by the for- 
 mer of these methods ; and though the latter is 
 less open to objection, yet we shall best consult 
 that convenience to the student which it is the great 
 object of all such arrangements to promote, by as- 
 signing to so important a series a distinct place in 
 the general system. Different authors have as- 
 
65 
 
 signed different names to these classes, from their 
 Theoretical views : the present terms are from the 
 fact of their relative position. Regarding the Car- 
 boniferous as the middle group, the term medial has 
 been given to it, and super-medial to the one next 
 above, and sub-medial to the one next below. The 
 superior and inferior are applied to the highest and 
 lowest series. 
 
 The terms Primary, Secondary and Tertiary 
 are, in general, applicable to all known countries, 
 but it does not follow that they are necessarily 
 parts of the same formation, extending to different 
 countries ; as independent formations are numer- 
 ous and extensive, and occasionally some may be 
 wanting. Thus in many parts of our own country, 
 the older secondary (by the pupils of Werner call- 
 ed Transition^ is not to be found ; and even on the 
 borders of the Alleganies, can scarcely be defined. 
 Moreover, we are not prepared to allow in full 
 extent the existence of universal formations. If 
 we once admit that idea, we must acknowledge 
 the trap of the Pallisades on the Hudson is the 
 same as that of Edinburgh and the coal of Le- 
 high and Providence a part of the bed of New 
 Castle or of New Holland. 
 
66 
 
 The Primary or Primitive Rocks are those hav- 
 ing more or less, a crystalline texture : they contain 
 no organic remains and form the extremes of all 
 series that is to say, they are the highest as well 
 as the lowest rocks. They are the lowest as all 
 others rest upon them and are the highest, be- 
 cause being highly inclined, and sometimes almost 
 Vertical, they rise to day at the summit of the 
 loftiest mountains. Granite, Gneiss and Mica 
 Slate are the most prominent of the primary class 
 though they by no means constitute the class as 
 was formerly supposed. 
 
 The Allegany Mountains constitute the primi- 
 tive range of the United States. 
 
 The Secondary Rocks are those lying on the 
 Primary, usually on their declevities or at their 
 feet. Their texture is very seldom crystalline ; 
 but more or less granular, being in a majority of 
 cases, composed of the fragments of the older 
 rocks, united by some cement. They contain or- 
 ganic remains : Their elevation is not so great as 
 those of the preceding class. 
 
 Sandstones, Limestones and Slates are the chief 
 members of this class. The greater part of our 
 Western Country is of these formations. The 
 great basin of the Mississippi may be termed 
 Secondary. 
 
67 
 
 The Tertiary Class are those of more recent 
 origin and are all placed above the chalk. It is 
 but a few years that these beds have been studied 
 but they are extremely interesting their tex- 
 ure is earthy more or less their position nearly 
 horizontal. Their organic remains are many and 
 beautiful. Until lately this class has been con- 
 founded with Alluvial. Our sea-board from 
 Martha's Vineyard, including great part of Long 
 Island and New-Jersey indeed all that country 
 between the Allegany Mountains and the Ocean 
 is Tertiary. 
 
 Alluvial beds are mostly local and are de- 
 posits of comparatively very recent formation in- 
 deed these deposits are constantly going on, and 
 form one of the great changes now operating on 
 our planet. They are composed of finer particles 
 mostly, though not always, that are carried for- 
 ward by water, and deposited mechanically nev- 
 er perhaps by chemical precipitation. They are 
 usually on plains, at the mouths of rivers, or at the 
 margin of mountainous ridges. They consist usu- 
 ally of sand, clay, loam and gravel and proceed 
 mostly from the disintegration of rocks, by the ac- 
 tion of running water, or of the atmosphere. 
 When carried forward by rivers, and deposited 
 
 
68 
 
 at their mouths, they form sub-marine beds and 
 islands, and eventual!} often fill up lakes and har- 
 bours. The sea casts up large quantities of sand, 
 &c. increases its shore, and is gradually forced to 
 retire before its own offspring. Girgenti, the an- 
 cient Agrigentum, in Sicily, was formerly a seaport 
 of great consequence. When I visited these mag- 
 nificent ruins, in 1819, they were more than four 
 miles from the beach. 
 
 The extent and depth of these deposits vary, 
 and will be spoken of more at large when treating 
 of formations in detail. 
 
 I may remark, however, that when connected 
 with mountains and large rivers, they often con- 
 tain grains of metal, as gold, tin and iron, in such 
 quantities as to render them worth exploring. 
 Thus a shaft was sunk in the harbour of Falmouth, 
 (Eng.) 50 feet through alluvial which originated 
 in granite, and a thick bed of from 2 to 10 feet, 
 found at the bottom, composed of round masses of 
 tin, which produced 50,000 stg. 
 
 During the reign of Queen Elizabeth the allu- 
 vial near the Lead Hills of Scotland was washed 
 for the purpose of finding grains of the precious 
 metals, and 300 men were employed. The pro- 
 duce is stated to have been 100,000 stg. 
 
69 
 
 We are not to infer from this, however, that the 
 gold found in the sands of certain rivers has been 
 always detached from rocks by the action of 
 water : since the auriferous sand is frequently con- 
 fined to a small district of the river nor is it al- 
 ways found near to the mountains nor is it al- 
 ways in level countries : The Rhine furnishes less 
 gold at Basle than at Strasburg, much farther from 
 the mountains whence it proceeds : and the river 
 Tessino deposits no auriferous sand until it has 
 passed the Lago Maggiore. 
 
 The alluvial sands of the Danube, the Rhine, 
 the Rhone, Tagus and other European rivers af- 
 ford gold as do the alluvial of many of the rivers 
 of Asia. The alluvial valleys or plains of Africa 
 have long been famed for their gold dust. Our 
 own continent is rich in golden alluvium the gold 
 of Mexico is found chiefly in this soil. On the 
 coast of California are 1 4 leagues covered with 
 alluvial soil, containing lumps of gold. The gold of 
 North Carolina is also found in alluvial soil. The 
 largest masses of alluvial gold have not exceeded 
 30 Ibs. 
 
 The diamond, the sapphire, the ruby and the 
 hyacinth have also been carried down by cur- 
 
 10 
 
70 
 
 rents and found in alluvium. Organic remains are 
 frequent in these deposits. 
 
 Formerly, as before mentioned, all Deposits 
 were termed Alluvial, including many that are 
 Tertiary. 
 
 But we must distinguish from these deposits, the 
 Diluvial, a name given to those deposits which 
 have been made by an inundation that seems to 
 have covered all rocks, and to have deposited 
 their debris indiscriminately, forming the last 
 great geological change, which the surface of our 
 Earth appears to have undergone. 
 
 The rocks included in these classes obey cer- 
 tain laws in their order of arrangement ; and are 
 then said to have a conformable position as 
 seen in the figure, page 62. 
 
 Occasionally however some rocks do not obey 
 these laws and we find them lying on others to 
 which they bear no relation thus we find basalt 
 sometimes resting on sandstone, as at the Palli- 
 sades on the Hudson- which are then said to have 
 an unconformable position thus 
 
71 
 
 Jn the secondary rocks we often find pebbles, or 
 fragments of the older rocks, consolidated into a 
 mass by means of some cement. These are term- 
 ed conglomerates or pudding stones, when the 
 pebbles are rounded by attrition, or breccias 
 when they are fractured and angular. 
 
 In these conglomerates we usually notice peb- 
 bles that are broken, and have their fragments 
 near to them : but as such stones could not have 
 been broken without violent force, their position 
 clearly indicates that they have been subjected to 
 such violence in or near the spot where we now 
 observe them : Some of these broken stones do 
 not seem to their parts near to them thus indica- 
 ting that whatever may have broken them, they 
 have been brought here from some other spot, or 
 else their other parts have been carried to some 
 other place. 
 
 Some of these retain their angles so sharp as to 
 convince us that they never could have been much 
 tossed about while others show us their angles 
 and inequalities rounded off by friction in their 
 motions. The inference is, that, the rocks whence 
 these fragments were torn must have been solid, 
 and exposed to violence before the beds were 
 formed in which these fragments are found. 
 When such beds are not horizontal (or nearly so) 
 
72 
 
 we may conclude that they are not in the position in 
 which they were formed but have been elevated, 
 or depressed, by some convulsion posterior to 
 their formation. 
 
 1 have mentioned that organic remains have been 
 found in some rocks, and not in others. As in the 
 course of our duties this subject will often be 
 brought to mind, I must be allowed to enlarge up- 
 on it here, in preference to calling off your atten- 
 tion from the rocks, which we shall describe as 
 containing these remains of former continents and 
 oceans. 
 
 When I say that certain shells are peculiar to 
 certain beds, and that when in France or Ameri- 
 ca we find certain shells, and know them at once 
 to characterise certain formations of England or 
 Germany, I do not intend to assert the universal 
 identity of Geological formations ; but to notice the 
 remarkable uniformity of fossil conchology in cer- 
 tain beds. 
 
 The identity of mass and of fossils was, more 
 than 150 years ago, insisted on by Lister : but he 
 never dreamed of identity of mass, and diversity of 
 petrifaction, or of diversity of mass and indentity of 
 petrifactions ; and yet he observed, that forma- 
 tions which were distinct by the geognosy of situ- 
 
73 
 
 ation and superposition, contained in the most dis-' 
 tant parts of the world, similar species. 
 
 Of the identity of formations, one of the strong- 
 est proof is derived from zoology, which indicates 
 the identity of fossils in certain beds. The study 
 of these remains is a small, but very interesting and 
 valuable portion of the duties of the philosophical 
 enquirer. 
 
 To distinguish the geographical limits of extinct 
 animals and plants to recognise the genera and 
 species to which they may be referred to ascer*- 
 tain their relations to each other and to the clas- 
 ses, orders, and families of organised beings ; 
 their numbers, as relative to the rocks in which 
 they are found ; the progressive developement 
 of animal nature ; to arrange species of different 
 continents, and classify them according to zones, 
 climates and hemispheres ; to point out the dif- 
 ferences of fresh water and marine, offluviatile and 
 pelagic shells ; to note the identical species ac- 
 cruing in the same formation in different parts of 
 the globe, and allow them their due weight in the 
 determination of formations, belong to the study of 
 Geological Zoology a branch well deserving the 
 attention of the philosopher. 
 
 Properly to appreciate this knowledge, it is on- 
 ly necessary in our researches into nature, to en- 
 
74 
 
 deavour to distinguish strata which bear a resem-, 
 blance to each other, by aid of their fossil 
 contents. 
 
 In a bed of Grignon (in France) there have been 
 found 8 species of patella and tellina 10 of ve- 
 nericardia and turritella ; 12 of mellania and am- 
 pullaria ; 15 of mitra, bulimus arid cytherea ; 18 
 of ostrea and murex, 25 of plurostoma, 33 of fu- 
 sus, 60 of cerithium, and in fine, upwards of 500 
 different species of bivalves, besides many uni- 
 valves, &c. &c. 
 
 Saussure asserts* that at Monte Bolca there are 
 found 105 different species of fossil fish, 39 of which 
 are said to come from the Adriatic sea, 3 from the 
 African, 1 8 from those of South, and 1 1 from those 
 of North America. 
 
 Dolomieu states,t as does Playfair,f that in every 
 coal mine, the fern of America is blended with the 
 palm of Africa, and the bamboo of Asia. 
 
 The clay at the Isle of Sheppey, abounding in 
 sea shells, is reported to yield upwards of 700 va- 
 rieties of fossil fruit. 
 
 i 
 
 * 1335. 
 
 tJourn. de Phys. vol. 39. 
 
 illlustrations. 
 
Fresh water shells are mixed with marine shells 
 in several places, as near London. 
 
 The alternations of fresh and salt water pro- 
 ductions in the Isle of Wight, and in the Basin of 
 Paris are well known. 
 
 At Mont Matre the gypsum exhibits animals of 
 land, air and water.* The middle beds of that 
 rock contain fresh water shells, the upper and 
 lower marine shells.t 
 
 At Monte Bolca, impressions of fish occur with 
 land plants; and at Monte Pulgnasco, the bones 
 of the elephant and rhinosceros are mingled with 
 those of cetaceous animals.^ 
 
 Thus we see that a formation may contain, in 
 different strata, petrifactions specifically different, 
 but that some of the lowest stratum may be min- 
 gled with the great mass of species which occur 
 in the superimposed strata. When these are not 
 only specifically, but generically distinct, some 
 being fresh water, others pelagic, it has been 
 thought difficult to solve the unity of the forma- 
 tion. 
 
 *Journ. de Phys. vol. 77, p. 362. 
 |Id. vol. 77, p. 365. 
 
 jld. voL 39, p. 339 Vol. 66, p 105 Vol. 69, p. 81 Vol. 
 30, p. 50. 
 
76 
 
 A large mass of marine shells may contain some 
 fluviatile shells, or they may alternate in beds. 
 Brongniart* and Beudantf mention the experi- 
 ments made by the latter to prove how many flu- 
 viatile molu sea can accustom themselves to live in 
 the ocean. Certain species of palludinse prefer 
 brackish waters, and are associated sometimes 
 with pelagic, sometimes with fluviatile shells. 
 Humboldt has seen crocodiles on the coast of Ter- 
 ra Firma advance far into the sea.J 
 
 Relative to the distribution of organic remains, 
 a fact has been advanced to prove that there are 
 alternate beds of marie and gypsum, between two 
 marine formations, containing fresh water and 
 land productions in the centre, and marine pro- 
 ductions above and below. This is the case 
 (as mentioned before) with the gypsum at Mont 
 Matre. These alternations and intermixtures in 
 the basins of Paris and the Isle of Wight, have 
 been attributed to alternate encroachments and 
 retreats of the sea, and the occasional existence of 
 fresh water lakes. The variety of species among 
 the petrifactions, and the alternations of beds, are ? 
 
 * Geogr. Min. pp. 57, 54,89. 
 
 t Jour, de Phys. vol. 88, p. 137, 211. 
 
 +Eq. Reg. vol. 1, p. 535 and vol. 2, p. 606 
 
77 
 
 by some, supposed to be not sufficient to sanction 
 the idea that each bed is of a different formation, 
 or that the beds are confused, and without Geo- 
 logical position. It should be observed, however, 
 that even Messrs. Cuvier and Brongniart assign to 
 the same formation some marine and fresh water 
 marles and gypsums. Indeed they illustrate the 
 term Formation by this very alternation of beds. 
 
 A difference having been noticed between fossil 
 and the existing Crustacea and other animals, na-< 
 turalists were induced to examine more minutely, 
 into specific characters ; and the result has been- 
 a conviction that organic remains have been de- 1 
 posited in successive generations, and in such or- / 
 der, that those of one bed bear a certain connect- 
 ion to each other, and exhibit peculiar distinctive 
 points from those of earlier or of later deposit : and' 
 that the greater the distance between the differ-' 
 ent deposits, the greater the difference between 
 the contained fossils. This deduction, combatted ' 
 at first by the most learned, and ridiculed by the 
 novi homines of science, has been found in strict 
 conformity with the phenomena exhibited by ani- 
 mal or vegitable fossil remains in different parts of 
 the world. The idea is now prevalent in Europe, 
 and upheld by the most learned and celebrated 
 
 Naturalists, that the successive generations of or- ' 
 11 
 
78 
 
 * ganised bodies that have dwelt on crust of 
 
 , globe, differ from the present generations, in pro- 
 portion as their remains are farther from the Earth's 
 ^surface ; or, in other words, in proportion as the 
 
 time in which they existed is more remote from 
 *the present day. 
 
 These successive generations are discovered 
 only in the strata forming the crust of our globe, 
 which was composed by different operations ; each 
 possessing distinctive characters, drawn from the 
 nature, order and structure of the rocks, and ac- 
 companying minerals. To distinguish the periods 
 at which these different deposits have been made, 
 is one part of Geology and this is best and most 
 
 ^ accurately done, according to M. Brongniart, by 
 the study of organised bodies. Even should the 
 characters taken from the nature of the rocks, 
 from the height of the deposit, from the scooping 
 of vallies, the inclination of beds, and their strata- 
 fication, be at variance with that derived from or- 
 ganic remains, he still considers the latter as of 
 superior validity. He illustrates his opinion by a 
 notice of Calabria, which for 40 years has suffered 
 the most dreadful disturbances from earthquakes : 
 horizontal beds have become vertical : entire de- 
 
 - posits have been transported to a distance, and 
 have been placed unconformably (or hap hazzard) 
 
79 
 
 upon other deposits ; and yet these masses and de- i 
 posits are never referred to different Geological * 
 periods. He fully acknowledges the force of char- 
 acters drawn from the rocks themselves, but avows 
 a preference for those drawn from the fossils they \ 
 contain. 
 
 The labours of Mons. Brongniart, in addition to 
 his advancement of the study of subterranean con- 
 chology, have served to prove the identity of some 
 formations in Europe with some of our own coun- 
 try : thereby confirming more fully his opinion, that 
 each formation has, so to speak, its own Flora or 
 Fauna, modified by time and space. 
 
 Zoology is thus made to render a service very 
 important to its sister Science, by the determina- 
 tion of relations between the formations and their 
 fossil contents. Not only in comparing neighbour- 
 ing strata, but in ascertaining those of foreign 
 and distant countries, Zoology and Botany are 
 themselves elevated above the mere inspection and 
 comparison of distinctive characters, and now in- 
 vestigate the whole of vegitable and animal organ- 
 ization. 
 
 The degree of analogy or similarity between fos- 
 sil and existing plants and animals is, by this ex- 
 tensive view, made of the utmost importance, 
 though it may be somewhat difficult to draw the 
 
80 
 
 corresponding marks and characteristics of ibssii, 
 with recent or living individuals, species and gen- 
 era. This resemblance, it will be seen, leads to 
 deductions important to a complete Theory of the 
 Earth. 
 
 Much prudence and deep research are to be 
 employed in the application of our attainments in 
 Fossil Zoology and Botany : nor has this escaped 
 the accurate and penetrating mind of the Natural- 
 ist who first established the importance of this 
 study : thereby coinciding with the views of the 
 deceased Werner, who never failed, in the course 
 of his lectures, to fix the attention of his pupils on 
 the relations that exist between certain fossils and 
 formations of different ages.* 
 
 " 1 do not deny, says Mons. B. that much atten- 
 tion and discretion are necessary to be used in 
 such a matter. It is requisite to distinguish and 
 estimate even the influence of horizontal distances 
 and of climates upon the specific differences : we 
 must know to appreciate the apparent, sometimes 
 even the real points of resemblance, which present 
 themselves, in formations which are evidently very 
 distinct, in certain species which have had the 
 rare privilege of surviving the destruction of their 
 
 *Essai sur le Gisement des roches. 
 
81 
 
 -"Of ' 
 
 contemporaries, and of remaining always the 
 same, in the midst of all the changes which have 
 taken place around them. It is necessary to know, 
 and to recognise, the individuals wrested from 
 other deposits and transported, (by whatever cau- 
 ses) to new ones : and to distinguish them from 
 those which have lived in the places and times 
 which the species to which they belong ought to 
 characterise. All these difficulties are to be ac- 
 knowledged ; and we must be on our guard against 
 those causes of deception which introduce uncer- 
 tainties in Geology, such as we meet in other sci- 
 ences and which impose upon the Geologist un- 
 remitting attention and labour, to employ with dis- 
 cernment the fossil and recent species whence he 
 takes his characters, and to attach to them the true 
 value that belongs to them in Geological re- 
 searches. 
 
 In speaking of the Earth's surface, we usually 
 divide it into Dry Land and Bottom of the Sea. 
 
 Of the Bottom of the Sea It was formerly sup- 
 posed that fossil coal and other bituminous sub- 
 stances existed there in such quantity as to cause 
 the bitterness of its waters and Count Marsigli 
 made many experiments to ascertain the truth of 
 
82 
 
 the supposition. No experiments, however, with 
 our present means, can be sufficiently accurate to 
 determine this question. Since the true bottom may 
 be, and we know often is covered by fortuitous mix- 
 tures of various substances, so as to prevent a plum- 
 met from bringing up correct proofs of its nature. 
 Veins of bitumen and salt doubtless continue the 
 same, arid in the same order under the sea, that we 
 find them on the land; and the same strata of 
 
 rocks which support hills, &c. on shore, no doubt 
 serve in the same way to support the immense 
 
 , mass of Ocean water. It is probable too, that the 
 metallic and other veins existing in the Earth, run 
 
 i in the same manner at the bottom of the Sea. The 
 
 , loose particles perhaps carried off to deep water, 
 and there deposited but some of the veins may 
 c be exposed, and probably yield that beautiful me- 
 
 tallic lustre, which we so frequently find on sub- 
 t stances drawn from the depths of Ocean. 
 
 } Subterranean rivers, it is probable, make great 
 
 changes in the bottom of the sea. We know of the 
 
 existence of subterranean currents, and the effects 
 
 *they sometimes produce on the surface of the globe, 
 
 v such as the falling in of large portions of ground 
 
 ' and the undermining of mountains. In the same 
 
 way we know of the existence of submarine cur- 
 rents, which may, or may not be occasioned by the 
 
83 
 
 breaking out of rivers at the bottom of the sea, and 
 thus tend at the same time to alter the natural sur-> 
 face at the bottom. In clear water, near the shore? 
 we often see these currents, and can draw up the 
 fresh water. 
 
 It is a pretty universal rule among those of our 
 brethren, whose " home is on the mountain wave," 
 the sailors, that in proportion as shores are rocky, 
 high, and steep, so is the depth of water below 8 
 them: and that low, level shores indicate shallow 
 water. It is generally acknowledged that the* 
 deepest part of the Mediterranean is under the 
 height of Malta and we know that in approach- 
 ing Long Island, the water is shallow. A know- 
 ledge of the strata on shore, in this way, may * 
 teach us the materials forming the bottom, as it ' 
 stretches under water for some considerable dis- ' 
 tance. 
 
 It may justly be supposed that the inequalities J 
 under water are the same as those above. Capt.' 
 Cook in the Pacific, tried sounding, unsuccessfully, 
 with 250 fathoms of line. Capt. Scoresby tried 
 1200 fathoms in the Arctic seas, without finding 
 bottom. Besides a direct knowledge of the depth* 
 of water by the use of the plumb-line and the ' 
 inference drawn from the appearance of the shore, 
 we have another criterion I mean the thermome- ! 
 
84 
 
 uer, to tell us when we have shoal water. This 
 Instrument shows a diminution of temperature in 
 &he water as we approach land. I dwell particu- 
 larly on this fact, as it is owing to a want of know- 
 ledge of these particulars, that two fine packets 
 in the Liverpool line have been lost within a few 
 miles of our city, within the last eight months. 
 Losses that may justly be attributable to igno- 
 rance I do not say carelessness so sure an in- 
 dicator is the thermometer, in the water, of the 
 approach of land, particularly on the East coast 
 of the United States. I may refer for particulars 
 to an Essay on the Natural History of the Ocean, 
 published by Professor Silliman, in the 5th vol. 
 of his American Journal of Science. 
 
 The coral fisheries give us occasion to discover 
 
 the existence of many large submarine caverns, 
 
 -.which, from the action of the water, are more 
 
 liable to become large and empty, by the solution 
 
 0f mud &c., than caverns are on dry land. 
 
 From all these circumstances, in conjunction 
 with others which it would be needless to enume- 
 rate, we have reason to conclude, that the bottom 
 of the sea is composed of and covered by the 
 same substances as the surface of dry land, viz. 
 rocks, clay, sand, &c. It is in most, perhaps in all 
 places covered with an accidental coat. In deep 
 
85 
 
 water, where the surface only is agitated, the bot- 1 
 torn is never disturbed : from such places, the i 
 plummet brings up pure white sand, or a mixture 
 of triturated shells or a powder formed of the 
 fragments of coral, or parts of rocks. 
 
 The bed of ocean too has its appropriate shrubs* 
 plants, and flowers ; and no doubt the geographical 
 distribution of submarine plants is as nicely and 
 strictly defined as that of Alpine or other plants 
 and many of them are extremely beautiful. 
 
 From the depths of the sea we often draw up 
 substances of the most brilliant colours scarlet, 
 vermiilion, purple, blue, green, and snowy white : 
 not superficial and transient, but in most cases* 
 real and permanent. Some marine substances, as ' 
 coral, &c., do, however, exhibit on being first drawn 
 from the water, the most superb and brilliant co- 
 lours, which are evanescent, and fade in a moment. 
 The small quantities we find on marine bodies, as 
 we approach deep water, may give us some idea 
 of what we might find in the deep and unfathom- 
 able recesses. 
 
 " Full many a gem of purest ray serene, 
 The dark unfathomed caves of ocean bear/ 
 
 12 
 
36 
 
 A poet has beautifully described a submarine 
 scene. 
 
 It was a Garden beyond all price, 
 
 Even yet it was a place of paradise ; 
 For where the mighty ocean could not spare.. 
 
 There had he, with his own creation, 
 Sought to repair his work of devastation! 
 And here were coral bowers, 
 And grots of madrepores, 
 And banks of sponge, as soft and fair to eye 
 As e'er was mossy bed. 
 Here, too, were living flowers, 
 Which, like a bud compacted, 
 Their purple cups contracted, 
 And now in open blossoms spread, 
 Stretched like green anthers many a seeking head. 
 
 And arborets of jointed stone were there, 
 And plants of fibres fine, as silkworm's thread : 
 Yea, beautiful as mermaid's golden hair, 
 
 Upon the waves dispread : 
 Others, that like the broad banana growing, 
 Raised their long wrinkled leaves of purple hue ? 
 
 Like streamers wide outflowing. 
 And whatsoe'er the depths of ocean hide 
 From human eyes, Ladurlad there espied, 
 Trees of the deep, and shrubs and fruits and flowers, 
 As fair as ours. 
 
 A silver trunk, 
 The fine gold net work growing out 
 
 Loose from its rugged boughs, 
 Tall, as the cedar of the mountain, here 
 Rose the gold branches, hung with emerald leaves,. 
 Blossom'd with pearls, and rich with ruby fruit. 
 
87 
 
 Dry Land is divided into Highland and Lowland. 
 By Lowland is meant an extensive country, flat, or 
 of inconsiderable elevation above the sea compo- 
 sed mostly of plains, and hilly as it approaches the 
 Alpine district. The few elevations that occur in 
 it are small, and chiefly in the central part. 
 
 We have one immense tract of Lowland, tra- 
 versed by the Mississippi and Missouri, bordering 
 east on the Appalachian, and west on the Rocky 
 Mountains. 
 
 In South America there is also one extensive 
 district of low land, bordering on the Andes. 
 
 The principal Lowland of Europe comprises 
 the Eastern portion of Britain and the northern 
 part of France, the Netherlands the north of Ger- 
 many and Silesia, all Poland, and the north west 
 part of the Rusian Empire. 
 
 The central portion of Asia consists of one great 
 Lowland Tract, called the Steppes. 
 
 The extent of this division of surface in Africa 
 has never been ascertained. 
 
 Alpine land is composed of groups of mountains, 
 which are again formed of mountain chains, or a 
 series of single mountains. 
 
 Mountain groups are usually highest in the mid-' 
 die, and in an Alpine country each takes a differ-' 
 
88 
 
 ent direction, being separated by plains and val- 
 lies, or by hilly districts. Each group forms a 
 whole, both as to base and acclivity, partially in- 
 tersected in many places, but never to the base, 
 except at the termination of the chain. 
 i Mountainous land is composed of single moun- 
 tains collected into chains, which, however, not 
 being united by an Alpine or central chain, never 
 form groups. 
 
 The rounded, undulating elevations of hilly dis- 
 tricts are much lower than the preceding, and 
 form a gradual transition to Lowland. 
 
 The summit of a mountain chain is called its 
 ridge, and the concavities in a mountain group, 
 which usually run parallel to its longest direction, 
 vallies. 
 
 High mountain groups are those of an elevation 
 of 7000 feet and upwards as the Andes, Alps ? 
 Pyrennees, &c. Mountains of middle height, are 
 from 4 to 6000 feet high. Low groups are from 
 700 to 3000 feet in height. 
 
 Generally the length of a Mountain Group is in 
 proportion to its height, and to the breadth of its 
 base. If the breadth and length are nearly the 
 same, it is called Massive. If the length is consider- 
 able in proportion to its base, we say it is a long 
 Mountain ^Group. Another distinction is derived 
 
89 
 
 irom the form and the connection of mountains 
 composing the group, as the Common, the Alpine, 
 and the Conic Mountain Groups. 
 
 With regard to the diff< rent parts of a Mountain, 
 we recognise the foot, acclivity and summit. The 
 foot is usually flat, and more or less extensive. 
 The acclivity is usually considered as the steepest ' 
 part of the mountain, and is often almost a perpen- 
 dicular precipice. The more gradual and gentle 
 the ascent of a moutain, the more rich does it gen- 
 erally prove in ores. 
 
 The summit varies in steepness and shape ; and 
 the latter is indicative of the nature of the rock of 
 which it is composed. Thus Granite and the Pri- ' 
 mary Rocks usually have sharp peaks. The elder 
 Secondary (or Transition) are rounded : Clay and 
 Basalt present short and obtuse conical summits. 
 
 Though Mountains are styled " La Charpente 
 et 1'Ossature du Globe Terrestre,'' yet the highest 
 are but mere specks in proportion to the diameter 
 of the Earth. Thus Mount Blanc, the highest in 
 Europe, is on the surface of our planet, what a 
 single line would be on a globe of 2 1 feet diameter. 
 
 In speaking of Mountains, I must be allowed to 
 notice a Theory^ accounting for their origin which 
 has lately been proposed by a Mons. Chabrier in 
 
90 
 
 a Dissertation, not long since published, on the 
 General Deluge. Having observed the immense 
 blocks of Granite scatterred over the North of Ger- 
 many, and not being able to trace them satisfac- 
 torily (for himself) to the Mountains of Sweden or 
 the Hartz he wisely has concluded them to be 
 Aerolites. Having proved this to hi .3 own satisfac- 
 tion and having ascertained that mountains are 
 only heaps of rubbish, he doubted if granite and the 
 primary rocks were ever deposited from a sea 
 which nobody had ever seen and from other sim- 
 ilar arguments, he asserts, that granite came, as it 
 now exists, from the atmosphere, with the accom- 
 panying substances. This terrible shower of 
 mountains arising from the fragments of a planetary 
 body violently struck by a comet, rained at once 
 upon the nucleus of ours (which gives him no con- 
 concern) the Alps, Pyrenees and Andes and the 
 Allegany and Rocky Mountains. The substances in 
 falling crushed the tufted forest and produced coal 
 by compression. The destroyed planet was that 
 which had for its satellites the four little moons, 
 Ceres, Pallas, Vesta and Juno, which even now 
 irrefragibly prove the former existence of that un- 
 fortunate planet. 
 
 But even this monstrous shower of mountains 
 does not satisfy the gentleman. It was accompa- 
 
n ' 
 
 med by all the waters of the planet, which falling 
 in torrents submerged the Earth, and deluged the 
 inhabitants : but the rain of waters preceded the 
 rain of solids and mountains, which last came very 
 opportunely to confine the waters, in part, and 
 form our continents. The fossil remains of trees, 
 offish, and the skeleton of a man found at Guada- 
 loupe, are the remains of the vegitable and animal 
 kingdom of the unhappy planet. 
 
 Mons. Cha brier supposes too that some of the in- 
 habitants of the unfortunate planet escaped the 
 general wreck, and survived the fall, notwithstand- 
 ing all this hard usage and he thus accounts for 
 the difference of races as observed by naturalists. 
 Thus the Negroes and Malays are probably the 
 decendants of the inhabitants of the other world 
 which at one and the same time charitably furnish- 
 ed us with mountains and negroes. 
 
 It seldom happens that all sides of a mountain 
 have the same acclivity, which fact has given rise 
 to various theories This difference was long ago 
 observed, but it was a Swedish Naturalist who first 
 noticed that it was so prevalent as to form a law. 
 His observation, however, related to the extreme 
 end only, and not to the flanks of mountains. He 
 

 92 
 
 stated that the steepest acclivity always faced that 
 part of the country where the land laid highest. 
 
 Bergman observed,* that the different declivi- 
 ties of the flanks of mountains bear an invariable 
 relation to their different aspects. He laid it down 
 as a rule, that mountains running from north to 
 south had always the west flank the steepest : and 
 that those running east and west had always the 
 south side the steepest. Thus, he said, the Alps 
 are steeper on the west and south than on the north 
 and east, and the Cordilleras are steepest on the 
 west 
 
 Buffon also noticed this fact as did Hermann, 
 who brought as evidence the Swedish and Nor- 
 wegian Mountains, the Alps, the Caucassian, the 
 Appenines and the Ouralians.. 
 
 The Carpathian Mountains, those of Norway, 
 those on the coast of Scotland, the Welsh Moun- 
 tains, those separating Saxony from Bohemia, the 
 Hartz, the Pyrennees, and those of Crim Tartary. 
 in Europe : The Mountains of India and of Syria, 
 and the Cordilleras are testimonies to the truth of 
 the observation. 
 
 I may here say that Pallas and Forster account 
 
 for the unequal declevities of the north and south 
 
 . 
 
 *Physic Descript. of the Earth. 
 
93 
 
 - 
 
 by the supposition of a great flood from the 
 south, giving the Earth its present form. 
 
 The celebrated Kirwan accounted for all these 
 inequalities by supposing a two fold violent motion 
 of the water, by which the globe was covered : the 
 one from north to south, the other from east to west. 
 This last being intercepted by such mountains as 
 run north and south, the impulse of the water was 
 checked, and the Earthy particles held in solution 
 by the water, were deposited on the eastern side, 
 which thus became more gentle and moderate : 
 while the west side could receive no such acces- 
 sion, and of course remained rugged and steep. 
 The northern current acted in a similar way, on 
 the north side of such mountains as running east 
 and west, intercepted its course. 
 
 It is worthy of observation, that all considerable 
 chains of mountains run in a direction north east 
 and south west. Our Alleganies are one proof of 
 this remark. 
 
 Vallies, dividing Mountains and furrowing the 
 surface, deserve the attention of the Geologist, as 
 connected with those events that have contributed 
 to produce the present state of our planet. 
 
 We find them commencing at great elevations, 
 and in their course uniting in the most efficient 
 
 manner to collect and carry off the water and 
 33 
 
-i * 
 
 94 
 
 moisture into some large stream, on its way to the 
 Ocean. They present such appearances as would 
 naturally arise from water forming channels for it- 
 self in retiring from land. On a very small scale, 
 this is daily repeated on muddy and sandy shores, 
 when the tide is out. The present inequalities of 
 hill and vale, afford strong reason for the supposi- 
 tion that it was water that produced them. We 
 are not however to overlook the effect produced 
 by the violent convulsions that seem to have ele- 
 vated and depressed strata, in so many cases. In 
 mountainous countries particularly, vallies seem to 
 have owed their first outline to the disruptive for- 
 ces in action around them. Instead of gentle slopes 
 we find deep hollows, with almost perpendicular 
 precipices, forming the receptacles of mountain 
 lakes. Yet even these vallies have been greatly 
 modified by water. In low countries, where no 
 disturbance of the surface or strata exists, we must 
 refer vallies entirely to the effects of running water. 
 The streams however that now flow through vallies 
 do not seem to have ever had sufficient power to 
 form the channels in which we now find them. An 
 eternity almost would be necessary in many 
 cases for the present rivers to produce the 
 vallies through which they now roll and even 
 then there would be physical impossibilities. What 
 
 
**, 
 
 95 
 
 . 
 an eternity, ibr instance, would be necessary tor 
 
 running water to produce the mountain passage 
 of the Highlands, and wear down the solid strata 
 of rock from the very summit of the Dunderberg 
 to the present channel in which our own noble 
 Hudson winds its way ! 
 
 Vallies, running in the course of the mountain 
 chains that bound them, are called Longitudinal 
 vallies, and those dividing the mountains from each 
 other, and cutting the mountain chain across, are 
 named Transverse Vallies. 
 
 It will not be denied that vallies have been form- 
 ed after the consolidation of the strata through 
 which they run ; for we find the same strata of 
 rocks on either side and in the same order. 
 
 This is the case in almost every valley and it 
 will be seen that they very generally cut the strata 
 across. 
 
 In a few cases, however, vallies do occur be- 
 tween different strata, running longitudinally with 
 
 
96 
 
 ~> 
 
 them ; and then the different sides of the vallies 
 are of course of different materials. 
 
 The cause that produced vailies has, in many 
 places, carried off the strata that once covered 
 masses of rock which we now find bare or insula- 
 ted hills : this disrobing of the rock has been 
 termed Denudation. 
 
 *It is well known that not only Argillite, but every member 
 of the primary class has been occasionally found in contact with 
 Granite. 
 
 
 
 
 

 LECTURE HI. 
 
 Changes produced on the Earth's Surface, by the 
 formation of Peat, fyc. of Coral Reefs Volcanoes 
 Observations on their Structure, frc. Vesuvius Etna 
 Sabrina Island Earthquakes those of Lisbon and 
 Calabria Volcanic Fire its Intensity Situation 
 and Origin. 
 
 Independent of the changes that are now con- 
 stantly going on by the partial agency of water, we 
 have other causes acting more powerfully in alter- 
 ing the present configuration of the Earth's sur- 
 face. Of these I shall briefly notice but three 
 viz. : 
 
 I. The formation of Peat , Bogs, and Mosses, 
 
 II. The formation of Coral Reefs and 
 
 HI. Internal Heat, as manifested by Volcanoes 
 and Earthquakes. 
 
 The change produced by the ibrmation of Peat 
 is partial and trivial compared with the others. 
 
 Mountain and Marsh Peat are formed in the 
 places whence their name is derived, by the de- 
 
98 
 
 composition of plants. In the shallow parts of 
 lakes are found numerous subaquatic plants, which 
 in summer flower at the surface and then sink to 
 the bottom. By the annual death of a portion of 
 these a stratum of peat is formed at the bottom? 
 where this process is constantly going on. The 
 death of fresh water shell fish, and the deposits of 
 earth and sand brought into the lake by streams, 
 assist in raising the bottom of the lake, and thus 
 prepare it for other plants ; in like manner to 
 thrive, blossom and die. 
 
 In other cases no distinct bed of peat is produ- 
 ced from the subaquatic plants but a stratum is 
 formed by the decay of land plants, which gradual- 
 ly extends into the lake and finally occupies its 
 bed. The shells, which for centuries have been 
 deposited at the bottom of the lake thus become 
 covered by peat, and are eventually consolidated 
 into marl beds thus offering one of the most use- 
 ful auxilliaries to Agriculture. 
 
 By occasional floods, sand, gravel, clay and 
 earthy particles are thrown over these thin strata 
 of peat, and destroy vegitation. By many and al- 
 ternate similar causes, a series of beds of peat and 
 of soil is produced, which eventually, exhausting 
 the lake, becomes a fertile field, instead of forming 
 a peat or moss meadow. 
 
 
t V " V *Sr -"" 
 
 N^'-v^w^N: 
 
 99 
 
 Different kinds of peat have their peculiar plants 
 entering into their formation. 
 
 Mountain Peat is formed principally by the fol- 
 lowing, viz. : 
 
 Erica cmerea, 
 
 vulgaris, 
 
 tetralix, 
 Myrica gale, 
 Empetrum nigrum, 
 Tormentilla erecta, 
 Arbutus uva ursi, 
 Vaccinium vitis idaea, 
 Juniperus communis, 
 
 In the formation of Marsh Peat, the sphagnum 
 palustre is the chief ingredient, assisted materially 
 however by the following, viz. : 
 
 Polytrichum commune, 
 Lycopodium clavatum, 
 Lichen rangiferinus, 
 Nardus stnctus, 
 Scirpus caespitosus, 
 Juncus squarrosus, 
 Many grasses of the genera, 
 Aira, agrostis, and carex. 
 
 Erica vulgaris, 
 tetralix, 
 Myrica gale, 
 Vaccinium oxycoccos, 
 Eryophorum polystachium, 
 
 vaginatum, 
 Schoenus albus, and others of 
 
 this genus, 
 
 Scirpus caespitosus, and oth- 
 ers of this genus, 
 Pedicularis palustris, 
 sylvatica, 
 Orchis maculata, 
 conopsea, 
 Aira aquatica, 
 
 caespitosa, 
 Festuca fluitans, 
 
 Caltha palustris, 
 Hydrocotyle vulgaris, 
 Lysimachia tenella, 
 Menyanthes trifoliata, 
 Ranunculus flammula, 
 Com arum palustre, 
 Narthecium ossifragum, 
 Pinguicula vulgaris, 
 Drosera longifolia, 
 anglica, 
 rotundifolia, 
 Triglochin palustre, 
 Phalaris arundinacea, 
 Arundo phragmates, 
 Juncus, many species, 
 Carex, many species. 
 Some of the Equiseta. 
 
 Lake Peat receives into its composition the fol- 
 lowing plants. 
 
 Conferva bullosa, Arundo phragmates, 
 
 Lemna minor, Subularia aquatica, 
 
 trisulca, Lobelia dortmanna, 
 
100 
 
 Nymphaea alba, 
 lutea, 
 Potamogeton natans, 
 
 heterophyllum, 
 and others of this genus, 
 Chara vulgaris, 
 Hippuris vulgaris, 
 Callitriche verna, 
 
 autumn alls, 
 Myriophyllum spicatum, 
 
 verticillatum, 
 
 Ceratophyllum demersum, 
 Utricularia vulgaris, 
 
 minor, 
 Sparganium natans, 
 
 erectum, 
 
 Ranunculus aquatilis, 
 Hydrocharis morsus ranae, 
 
 Scirpus acicularis, 
 
 lacustris, 
 
 setaceous and others, 
 Isoetes lacustris, 
 Alisma pi ant ago, 
 
 ranunculoides and 
 others, 
 
 Saggittaria sagittifolia, 
 Butomus umbellatus, 
 Acorus calamus, 
 Phalaris Arundinacea. 
 Poa aquatica, 
 Juncus conglomerate, 
 
 effusus, and others, 
 Schoenus mariscus, and 
 
 others, 
 
 Menyanthes triofoliata, 
 Comarum palustre, 
 Equiseta several species. 
 
 Bogs and Mosses are also accumulations of veg- 
 itable matter in wet ground settling in successive 
 generations on itself, until its bulk rises considera- 
 bly above the level of its bed. The surface of a 
 bog is always undulated, and terminates abruptly, 
 sometimes almost perpendicularly. The average 
 height of the great Irish bogs is about 250 feet 
 above high water mark in Dublin harbour. 
 
 Quaking bogs are produced in wet, flat grounds, 
 where springs abound. Weeds, shrubs, and trees, by 
 their decay and fall, assist in darning up the stream, 
 and the water becoming stagnant, the whole flat is 
 overflowed. A coarse grass, which is peculiar to 
 these bogs, springs up in tufts : the roots become 
 closely interwoven, and in a few seasons they grow 
 
101 
 
 to a considerable height. The decay of these 
 plants in winter, furnishes soil for the reception and 
 germination of the seeds The tops of flags and 
 grass occasionally become intermixed and consoli- 
 dated on the surface of the water, and increasing 
 in thickness and extent, cover the superficies.- 
 This receives seeds, which grow and cover it with 
 vegitation, and becomes so strong as to bear a man, 
 but still in some places trembles, or quakes* 
 whence the name is derived. 
 
 The formation of coral reefs is daily producing 
 a change, more or less, on that part of our globe 
 at present covered by water, but more particular- 
 ly in the Pacific Ocean. They are the production 
 of the combined labours of millions of marine 
 zoophytes, usually termed the connecting link be- 
 tween the animal and vegitable kingdoms, but per- 
 haps more justly considered as that link between 
 the animal and mineral kingdoms. The never 
 ending industry of these minute animals, is sup- 
 posed by many naturalists to work changes in our 
 globe far surpassing even those produced by the 
 fearful and powerful agency of subterranean fire 
 
 by means of Volcanoes and Earthquakes. 
 14 
 
102 
 
 The common foundation of all those clusters of 
 Islands discovered in the Pacific, as well as those 
 of New South Wales, is of coral structure ; ex- 
 tensive reefs of which run off in all directions. 
 
 Banks of coral are found at all depths, having 
 no communication with each other and at all dis- 
 tances from land. By a rapid increase they ar- 
 rive at or near the surface, when winds and waves 
 force up loose fragments from deeper water, and, 
 an accumulation thus going forward, islands are 
 seen in all the different stages of progressive for- 
 mation as shoals first then as reefs or breakers 
 eventually as bare rock above the water, and 
 finally in their state of perfection, covered with soil, 
 and adorned in all the beauties of vegitation. 
 
 Kotzebue in his voyage to the Pacific, and Capt- 
 Flinders, in his account of New South Wales, have 
 each given many pages to these interesting produc- 
 tions. 
 
 It seems probable that when these little animals 
 have commenced their labours, and have ceased 
 to live, their structures adhere together and the 
 small interstices being filled with sand, a solid 
 rock is soon the consequence. Future races con- 
 tinue to erect their habitation on the rising bank, 
 and die in turn, while elevating this monument of 
 their labours. It is by a surprising instinct that in 
 
103 
 
 the early stages of their labour, they work perpen- 
 dicularly ; and as they erect their wall chiefly in 
 situations where the winds are constant, they thus 
 afford a shelter to the leeward, whence their in- 
 fant colonies are sent off. It is owing to this that 
 the windward side of a reef of coral is always the 
 highest part, rising sometimes perpendicularly 
 from the depth of 200 feet, or perhaps as many 
 fathoms. 
 
 It seems necessary to our busy labourers to be 
 covered with water, in order that their work may 
 be uninterrupted, for as soon as the reef has reach- 
 ed such a height as to remain almost dry at low 
 water, at the time of ebb, the corals cease to build 
 higher ; sea-shells, fragments of corals, echinae and 
 their broken off prickles become united by the 
 burning sun, through the medium of the cementing 
 calcareous sand which has arisen from the pulveri- 
 zation of the shells, into one whole or solid stone ; 
 and this, strengthened by the continual throwing 
 up of new materials, gradually increases in thick- 
 ness, till at last, it becomes so high as only to be 
 covered by the high tides of particular seasons. 
 The solar rays so heat this mass when it is dry, 
 that it splits and breaks off into flakes. These 
 flakes are again thrown upon each other at high 
 tides. The active surf throws blocks of coral 
 
104 
 
 (sometimes 6 or 8 feet long and 3 or 4 thick) and 
 shells of marine animals between and upon the 
 foundation stones : after this the calcareous sand 
 lies undisturbed, and offers to the seeds of plants 
 and trees cast upon it by the waves, a soil, upon 
 which they rapidly grow to overshadow its daz- 
 zling white surface. Entire trunks of trees, car- 
 ried by rivers from other countries and islands, find 
 here, at length, an accidental resting place. With 
 these come some small animals, as lizards and in- 
 sects, as the first inhabitants. The sea bird 
 nestles there, and by feathers, &c. contributes to 
 the formation of a soil sea plants now take root 
 upon it a cocoa nut is cast on shore stray land 
 birds find it a refuge the seeds of shrubs and 
 trees are thus carried there, and when the work 
 has long been completed, man also appears, builds 
 his hut on the fruitful soil formed by the corrup- 
 tion of the leaves of the trees, and styles him- 
 self lord and proprietor of this new creation. 
 
 But of all the changes arising from causes now 
 m actual operation, those resulting from the agen- 
 cy of Subterranean Heat, by Volcanoes and Earth- 
 quakes, are the most remarkable and interesting. 
 
 The time allotted allows me to cast but a cur- 
 
105 
 
 sory glance at a few of the facts in connection with 
 these phenomena, which often in a few minutes 
 change the whole surface of a country. 
 
 In the earlier periods of our globe, these fires 
 seem to have been more extensively in action than 
 at present ; as is proved by the many remains of 
 extinct, volcanoes of great size which we find in 
 various parts of the world, and by the existence of 
 rocks nearly allied to volcanic products in almost 
 every country. 
 
 Of the structure of these mountains, I shall only 
 say that they are generally truncated cones, with an 
 aperture in the centre, called the Crater, whence 
 the eruptions issue : but not unfrequently they 
 break out at the side or foot of the mountains ; 
 and occasionally under the sea and are then 
 termed Submarine Volcanoes, or Eruptions. 
 
 Most of them are situated near the Ocean, or to 
 Lakes, whence many Geologists have supposed 
 that water forms one of the chief agents in vol- 
 canic phenomena. 
 
 When single, they have a pyramidal or conical 
 form, ascending at a moderate angle of inclina- 
 tion from the base to an elevated plain, from the 
 centre of which rises the principal crater. 
 
 No burning Volcano situated in a chain of moun- 
 tains is to be found in Europe or Asia they be- 
 
106 
 
 ing generally at a distance from them. On the 
 American Continent, on the contrary, Volcanoes 
 of the most stupendous size form part of the Cor- 
 dilleras. In the south of the province of Quito, in 
 Chili, and in Guatimala, they are grouped in rows. 
 Baron Humboldt than whom no man has ever 
 visited a greater number, or drawn more philo- 
 sophical deductions, in regard to them, has made 
 the following observations, viz. 
 
 1. That Mountains with slender conical peaks 
 have eruptions of the greatest violence and at the 
 shortest intervals as Cotopaxi,Peak of Teneriffe, 
 and Orizava in Mexico. 
 
 2. Those with long summits, rugged and rocky, 
 are nearly extinguished as Hecla in Iceland, and 
 many in South America. 
 
 3. That rounded summits indicate in many pla- 
 ces porphyritic lava, that has been heated and 
 raised up, but never burst forth as Chim- 
 borazo, and the greater Sarcony in Auvergne. 
 
 All Volcanic Mountains have the cone, or su- 
 gar loaf, as it is appropriately called, covered with 
 scoria?, or cinders and ashes. 1 myself believe that 
 the whole cone is composed of such substances as 
 have been ejected once, at least, those nearest 
 the heat being again consolidated. It has been 
 usual for travellers to state, that from the brim of 
 
107 
 
 the crater, it was easy to see the boiling lava with- 
 in. This good fortune did not attend me, as I 
 found it not only dangerous, but impossible to get 
 within such distance of the crater of Vesuvius, 
 during an eruption, as to allow the angle of vision 
 to be more than 45. But even had it been possible 
 to stand on the very rim of the crater, and cast the 
 eye directly downwards, the thick cloud of smoke 
 hanging within, would have concealed the burning 
 mass. 
 
 The shape of the crater is constantly varying 
 with every new eruption. Its size does riot de- 
 pend on the elevation or mass of the Volcanic 
 Mountain. Vesuvius is a small hill compared 
 with the Peak of Teneriffe, and it has a crater five 
 times larger. The Volcanoes of the Andes have 
 all small openings, and there are many reasons for 
 believing, that the size of the opening diminishes 
 as the elevation of the mountain is greater, were it 
 not that those of Cotopaxi and Rucipichinca have 
 craters three fourths of a mile in diameter. 
 
 The depth of a crater varies continually in ac- 
 tive volcanoes ; but in those long dormant, it under- 
 goes no change excepting that produced by the 
 occasional fall of part of its wall. In this case it 
 allows of actual measurement : thus the crater of 
 the Peak of Teneriffe is 105 feet deep. 
 
108 
 
 The whole cone of a Volcano is sometimes 
 swallowed up during an eruption, leaving a larger 
 circular crater, at a less elevation, which finally 
 becomes dormant, and forms a Lake. Such is the 
 celebrated Lake of Avernus, and that of Agnano, 
 near Naples. 
 
 Independent of the destructive changes pro- 
 duced by the burning lava, and by the scoriae fal- 
 ling in showers around the crater whole mountains 
 are sometimes formed at one eruption ; thus Monte 
 Nuovo about 10 miles from Naples was raised in 
 one night ; and Morite Rosso on Etna, with a base 
 of 2 miles in circumference, and a height of 750 
 feet, is composed of the scoriae that fell after one 
 eruption of 1 569. The color of the mass of ma- 
 terials of this last mountain is generally reddish, as 
 the name denotes, and the scoriae contains em- 
 beded schorl. 
 
 In the intendancy of Valladolid, in New Spain, 
 is an immense plain belong to the plantation Jorul- 
 lo, 2600 feet above the sea, and cultivated during 
 the last century with cane and indigo, having its 
 elevations crowned with evergreen oaks, and 
 palm trees. After some admonitory warnings, a 
 tract of ground, in this place, to the extent of 10 
 miles, rose in the shape of a bladder, being about 
 40 feet at the edges, and 534 feet at the centre 
 
109 
 
 above its former level. Many mountains soon after 
 rose on different parts of it, the most elevated of 
 which is the Volcano Jorullo. 
 
 There are other proofs of the reason we have to 
 consider internal heat as an active agent in the 
 production of Geological phenomena : but these 
 will suffice. 
 
 I have abstained from entering into minutiae con- 
 cerning any one volcano. Having visited some of 
 the most celebrated in Europe, I may perhaps be 
 indulged, at the risk of an imputation of egotism, 
 in briefly relating a few particulars. 
 
 In 1819, 1 had the satisfaction of seeing and of 
 visiting Vesuvius during an eruption. The dark- 
 ness of the night, the time I had chosen, (for my 
 first visit) rendered the scene more awful and sub- 
 lime. In ascending the cone, we traversed beds of 
 lava that but a few days before had been vomited 
 forth : Although the surface was black, the interior 
 was still a heated mass ; and we saw the yet red 
 lava through the small cracks in the surface. On 
 inserting through these fissures the sticks we had in 
 our hands, they were immediately withdrawn on 
 fire. We could not approach within 6 feet of the 
 rim of the crater, and even by crawling could not 
 get our faces near the edge, so as to see the bot- 
 tom or indeed any thing but a mass of cloud ob- 
 15 
 
110 
 
 structing the sight. The dreadful bellowing and 
 roaring of the interior was indeed awful, and at in- 
 tervals a sudden and tremendous explosion warn- 
 ed us of the shower of stones, that ascending in the 
 flames, were to fall red hot around us. These 
 stones were of all sizes, and we endeavored to 
 escape the shower by running down the cone. 
 
 About 100 feet below the brim of the crater, 
 through a hole in its side, gushed a constant stream 
 of liquid lava. It appeared of the consistency of 
 molten iron, and flowed slowly in the channel it 
 had formed for itself. From this liquid mass we 
 contrived, by the aid of poles, to detach small 
 masses, in which we inserted each some small arti- 
 cle, while the lava was pliable. Some silver that I 
 had in my pocket, jand my watch key, were among 
 the articles thus forced into the liquid lava, which 
 then cooled around them : as you now see them. 
 
 Having retired about 100 yards from this burn- 
 ing river, and thrown aside some of the smaller cin- 
 ders so as to form a small excavation on the spot 
 where a current of heated air was escaping, which 
 served to keep us warm, we took our supper, and 
 lighting our torches by the lava, wrote letters to 
 our friends and then slept, for an hour, before 
 the glorious orb of day, rejoicing in the east, call- 
 pd us to tho summit to behold its splendor. 
 
Ill 
 
 There are 36 eruptions of Vesuvius on record 
 previous to 1 806, since when they have been almost 
 annual. The bed oflava runs for many miles, and 
 often, as you are all aware, destroys towns and 
 cities. 
 
 Villages, and woods and rocks 
 
 Fall flat before its sweep. The region round, 
 Where myrtle walks, and groves of golden fruit 
 Rose fair ; where harvest waved in all its pride ; 
 And where the vineyard spread its purple store, 
 Maturing into nectar ; now despoiled 
 Of herb, leaf, fruit and flower, from end to end, 
 Lies buried under fire, a glowing sea ! 
 
 Mount Etna, in Sicily, had been long dormant, 
 when in 1819, 1 visited that volcano. Monti Gi- 
 bello, or Monte Bello, (from Mongibello, Mount of 
 Mounts) as it is called by the inhabitants, has been 
 so often visited and described, that it is needless, 
 nor would it be proper, for me, here, to enter into 
 a detail of its history or its beauties. Relative to 
 its history, it may be observed, that doubts have 
 arisen as to its origin ; which shall be spoken of in 
 another place ; here it is only necessary to observe 
 that Count Borch, and some other Geologists con- 
 sider Etna as a Granitic Mountain, containing 
 abundance of lead and copper, merely covered 
 by volcanic products. In proof of which, it is 
 alleged, that on the mountain shells exist at the 
 
112 
 
 height of 2000 feet above the sea and that strala 
 of clay with marine shells are found 2400 feet 
 above the sea, dipping towards it ; and which pro- 
 bably had been formed there while the mountain 
 was progressively rising from the ocean. But I 
 consider Etna as an assemblage of mountains, 
 piled on each other, and which have been pro- 
 duced by different eruptions from many volcanic 
 openings, most of which are now dormant : and 
 that the whole mass is thus an accumulation of 
 volcanic products. Monte Nuovo and nearly fifty 
 other mountains on that side of Etna next to Cata- 
 nia are formed wholly of ejected substances. 
 Many of them are now covered by a fertile soiK 
 though still exhibiting the crater well deiined. 
 
 After leaving the luxuriant and fertile region that 
 skirts the base of the mountain, and forced our 
 mules over the sterile band, near to the regions of 
 eternal snow, we passed this frozen zone on foot,, 
 and reached the cone, which we ascended. The 
 lower half was covered with snow. The upper 
 portion, nearly half a mile, was clear to the brim of 
 the crater. From the surface of this brim or edge, 
 Avhich was hot to the feet, arose heated air, strong- 
 ly impregnated with sulphur. As this air 
 or gas oozed through the surface it deposited 
 beautiful and brilliant crystals of sulphur. On 
 
breaking up the crust with our sticks, we saw them 
 glistening, and collected quantities of them : some 
 of which are now on this table. 
 
 The interior of the crater was covered with snow 1 
 near the bottom; except the northern side, 
 which rose a solid wall, separating it from another 
 crater. From cracks in this wall, and from a few 
 small openings in the bottom, a thin white smoke 
 was gently ascending, and, in small quantity, 
 gracefully curling itself into the atmosphere. 
 
 We descended some distance into the crater, in 
 pursuit of specimens of the many crystals known 
 to exist among the products of this volcano. 
 
 It was a mild and lovely evening, when, after 
 having been refreshed at St. Nicoloso, we continued 
 our way to the summit, so as to be there by sun- 
 rise. 1 only mention this to add that during our 
 ascent, we found it extremely cold before we 
 reached the frozen region and that we beheld at 
 the same time a thunder storm some distance at sea. 
 On leaving the summit for our descent, we experi- 
 enced all the vicissitudes of climate, extreme 
 cold, a snow storm, and several violent showers of 
 rain, with alternate intervals of a scorching and 
 brilliant sunshine. 
 
 We are all aware of the distance often run by 
 the lava from this volcano. Catania, nearly 40 
 
114 . 
 
 miles from its summit, has often been destroyed by 
 it. Taormina, about the same distance on another 
 side of the mountain, has often suffered the same 
 fate. In its vicinity is found a beautiful red lava. 
 
 The base of Etna covers a circumference of 
 about 36 miles ; and on its sides are not fewer 
 than 80 cities, towns, and villages, and allowing 
 from 1200 to 1500 persons to each, it may be safe- 
 ly stated that there are 100,000 people inhabiting 
 voluntarily the crust of this immense volcano. 
 
 One of the latest submarine volcanoes of which 
 we have an account, was that, which, in 1811, 
 burst forth in the Azores, near St. Michaels. 
 
 Immense clouds of black smoke were observed 
 to rise from the surface of the sea, when, suddenly 
 a column of cinders, ashes, and stones shot up with 
 great violence, accompanied by a grumbling noise 
 and vivid flashes of lightning. 
 
 The depth of water at the spot was formerly 
 180 feet. The quantity of ashes and scoriae was 
 so great that on the fourth day the accumulation 
 was seen to rise above the water, forming the rim 
 of the crater, which thus was reared among the 
 waves. 
 
115 
 
 The island of Sabrina, thus formed, rose about 
 250 feet from the sea, with a circumference of 
 about a mile, at the waters edge. 
 
 A similar island arose many years since, near to 
 Tercira, of the same group, in a single night. 
 
 The islands that have been produced by sub- 
 marine volcanoes in the Grecian Archipelago, are 
 among the most remarkable products of these 
 phenomena. 
 
 We all know that volcanoes eject many sub- 
 stances beside lava and that cinders and ashes 
 are sometimes projected to a great distance. The 
 celebrated Pompeia, which has so often been de- 
 scribed by other persons who have visited the in- 
 teresting ruins, was covered by ashes showered 
 upon it from Vesuvius, (from which it is distant 
 about 12 miles) in the year 79 of the Christian era. 
 
 Intimately connected with the preceding phe- 
 nomena, both as to cause and effect, is that dread- 
 ful convulsion of nature, for which no word in any 
 language has yet been found to convey an idea 
 sufficiently appalling. No word can impress upon 
 the mind the terror it occasions. The extensive, 
 immediate, and awful consequences of the earth- 
 quake, leave no hope, no refuge for the alarmed 
 individual no refuge but the refuge of despair. 
 
116 
 
 There is no country that is not more or less 
 affected by them : even the sea is subject to them. 
 
 The annals of the world mark no week, per- 
 haps no day, that is not a record of their devastation 
 No accurate account of the cause of earth- 
 quakes has been handed to us by preceeding 
 philosophers. All their investigations ended in 
 supposition, instead of collection, comparison, and 
 reflection. 
 
 One of the earliest earthquakes on record since 
 the Christian era, was that which, under Tiberius, 
 destroyed in one night 12 cities in Asia Minor, in 
 a circumference of about 300 miles in diameter. 
 It is remarkable that no other changes took place- 
 no springs or fountains were dried up, the course 
 of no river altered no hill overthrown but all 
 remains the same at the present day. 
 
 The history of the violent earthquakes that in the 
 sixty third and succeeding years of our era, preced- 
 ed those eruptions of Vesuvius, which destroyed 
 Herculaneum and Pompeia, and in which the el- 
 der Pliny lost his life, is familiar to most of us. 
 
 During that fearful one which preceded the erup- 
 tion of Vesuvius on Sept. 28, 1 538, the Lucrine 
 lake near Naples was lost a whole town and all 
 its inhabitants swallowed a tract of ground near 
 Lake Avernus rose up, and in one night Monte 
 
117 
 
 Nuovo (formerly mentioned) arose, and next morn- 
 ing showed an elevation of 1127 feet above the 
 level of the sea. The whole country was destroy- 
 ed, and in 24 hours not even the vestige of a habi- 
 tation was to be discerned. 
 
 The famous Earthquake of 1755 that destroyed 
 Lisbon, and that which in 1783 convulsed Calabria, 
 are the most important on modern records. A 
 mere outline of either would occupy an hour. 
 
 Of the violence of the former we may form some 
 idea, when we know that it was severely felt over all 
 Spain (except Catalonia, Arragon, and Valencia) 
 that in Africa it was almost as severe as in Eu- 
 rope that it was felt in England, Scotland, Nor- 
 way, Sweden, Germany, Holland, Switzerland and 
 Corsica even in Antigua and Barbadoes nay, 
 even on the shores of Lake Ontario. At Lisbon 
 it began 25 minutes past 9 in the morning. Be- 
 tween 9 and 1 the master of a vessel bound to the 
 West Indies, being then in north lat. 25, and west 
 long. 40, and many miles from land, heard a vio- 
 lent noise, and perceived his ship agitated as if by 
 a sudden jerk He started in great terror, and 
 perceived through the cabin window land at the 
 distance of about a mile, which, when he got on 
 deck, had disappeared. In another minute three 
 rocky pinnacles rose from the sea and spouted wa- 
 
148 
 
 ter, and a heavy dense cloud, which ascended, and 
 left no trace of the rocks. Another vessel, be- 
 tween 9 and 10 the same morning, about 40 
 leagues from St. Vincent, was violently jerked, as 
 if she had struck a rock, and all hands on board 
 were thrown down. The sea was agitated for a 
 minute, and then no trace of rock or storm ap- 
 peared. 
 
 The Earthquakes of Calabria were equally aw- 
 ful. Kircher, who witnessed one in 1 638, publish- 
 ed a long and interesting account of it. Hir Wil- 
 liam Hamilton has given a valuable and accurate 
 statement of the convulsions of this unhappy coun- 
 try, from which it appears, that in one year, 1783, 
 it suffered from 949 Earthquakes. 
 
 Their effects are still visible : I have witnessed 
 some of them with an anxiety of mind not to be im- 
 agined. The ordinary action of the elements can 
 never efface them. It can only be effected by 
 some convulsion even more terrible than its pre- 
 decessors. 
 
 It will easily be imagined that as Heat is (he 
 prime agent of one of the prevalent Geological 
 theories, and is so intimately connected with Vol- 
 canoes and Earthquakes, that many disputes have 
 arisen on the subject. They may however be 
 
reduced to three, viz. as to the Intensity, the 
 Situation, and the Origin of Volcanic Fire. 
 
 Messrs. Le Sage and Deluc, and afterwards Do- 
 lomieu, made a series of experiments on Lava, 
 which was found to vitrify more completely in fur- 
 naces than in volcanoes ; and many crystals that 
 were embedded in it were easily fused ; whence 
 they concluded that volcanic fire was not so very 
 intense, and that its effects were caused, rather by 
 extension and duration, than by activity. Sir Jas. 
 Hall overthrew the force of these experiments as 
 far as vitrification was concerned ; inasmuch as 
 vitrification, according to his experiments, does not 
 depend so much on the degree of heat, as on the 
 rapid cooling of the stone or lava. 
 
 He was further confirmed by the valuable ex- 
 periments of Mr. Watt, proving that if the process 
 of cooling be very slow indeed, a crystalline ar- 
 rangement of the particles is the consequence. 
 
 Observations, made by men who are capable of 
 judging, are far more important and conclusive 
 than any experiments ; and from a comparison of 
 these we are entitled to conclude, that sometimes 
 the heat of volcanoes exceeds that of the most pow- 
 erful artificial furnaces : but that the fluidity and 
 heat of lava does not always indicate such intense 
 heat. Spallanzani passed a current of lava upon Et- 
 
 

 120 
 
 na, that flowed 1 1 months previously and which 
 was still red hot at some distance beneath the sur- 
 face. The A bbe Ferrara mentions that when in 1 709 
 they opened at Catania the current which flowed 
 from Monte Rosso 40 years before, flames broke 
 forth, and the retained heat was so great even at 
 the beginning of this century, that rain, when it 
 fell upon it, passed off immediately in vapour. 
 
 Upon opening some houses in Torre del Greco, 
 nearly buried in the lava of Vesuvius in 1794, iron 
 utensils were found partially volatilized, and some 
 crystals of iron (specular) discovered on the 
 surface. 
 
 We know on the other hand that many crystals, 
 easily fusible by the blow pipe, are ejected unal- 
 tered by volcanoes. In the list of substances vomi- 
 ted forth, we find many that were, and many that 
 were not fused. Here is a specimen that sets all 
 caballing at rest a piece of lime, with an embed- 
 ed shell, sent forth during an eruption of Vesuvius, 
 and presented to me by Sig. Monticelli, so well 
 known as having indefatigably studied this volcano 
 for many years. 
 
 As to the Situation of volcanic fire, viz. whether 
 it originates in the mountain itself, or is placed at 
 a great depth below the surface : It has been sup- 
 posed that rolcanoes originally break out in 
 
121 
 
 mountains already formed, and merely cover them 
 with lava and scoriae. For instance, that Vesuvius 
 and Etna were always mountains, either primary 
 or secondary, and that volcanic fire has only alter- 
 ed their forms perhaps, and covered the surface 
 with lava, &c. On the other hand, it is asserted 
 that these mountains are entirely produced by sub- 
 terranean heat, and composed of the lava and 
 scoriae thrown up as the Monte Rosso (already 
 noticed) and Monte Nuovo, near Naples : or else 
 that they have been raised by subterranean heat, 
 which has softened and elevated the strata above 
 it, as mentioned in the tract of land in South Ameri- 
 ca, and on this a volcanic crater had been formed 
 similar to the Jorullo. 
 
 To a calm and unimpassioned man, to the phi- 
 losopher, both of these views will appear nearly 
 correct. There can be no doubt that Monte Ros- 
 so, Monte Nuovo and Jorullo were formed by er- 
 uptions even had we not the testimony of witnesses; 
 and we are justified in concluding that the source 
 of the heat was far below the base of these hills. 
 But there are many other volcanoes, to which such 
 origin cannot be attributed. On Etna, for instance, 
 we find calcareous strata, with imbedded remains of 
 shell fish resting on beds of volcanic tufa, and dip- 
 ping to the sea. Here the inference is plausible, 
 
 
122 
 
 that the first eruption took place beneath the sea, 
 and that the strata with marine organic remains 
 were deposited before the mountain rose from the 
 ocean. In fine, that the volcano existed be- 
 fore the mountain that its first eruption was 
 submarine, and the whole masses subsequent- 
 ly elevated, or the sea depressed. The same 
 may be said of the Peak of Teneriflfe and of 
 the Canary Islands. There is a great difference 
 between the elevating and breaking up of strata, 
 and the mere accumulation of lava and scoriae, of 
 which the celebrated Island Sabrina was formed 
 in 181 1 off St. Michaels in the Azores. It is prov- 
 ed by both phenomena that the location of volcanic 
 fire is far below the surface. Were it placed in 
 the mountain itself, we cannot conceive why, after 
 burning 1000 years, the walls do not fall in ; and 
 when once extinguished it would be very strange 
 that it should occur again in precisely the same 
 spot. 
 
 The supposition of the School of Werner, that 
 volcanic fire is seated in coal beds, is very inade- 
 quate : the depth would riot be great enough for 
 the production of the consequences the sides here 
 too would fall in ; and why. when once burned 
 out, and extinct for 700 years and upwards, should 
 
123 
 
 it break forth again in the same place ? A coal 
 pit near New-Castle (upon Tyne) took fire in 
 1648, and burned for 40 years, when it was ex- 
 tinguished, without a sign of volcanic fire. 
 
 Some philosophers have supposed that fire ex- 
 isted universally in the bowels of the Earth, and 
 that the contact of water with it produced steam, 
 the immediate cause of Earthquakes, which, when 
 it found an opening, was expelled in the form of an 
 eruption. Thus, they say, the Earthquakes of Ca- 
 iabria^and Sicily were always accompanied by 
 eruptions of Vesuvius or Etna : thus, during the 
 Earthquakes, formerly mentioned, of Lisbon, fire 
 was seen to rise in the middle of the Atlantic : 
 thus the Earthquakes of New Andalusia and the 
 West Indies are connected with the volcanoes of 
 the Andes : thus, when Caraccas was destroyed in 
 1812, St.Vincent, dormant for 100 years, broke out 
 afresh. The night when Callao and Lima were de- 
 stroyed, four new volcanoes appeared on the Andes. 
 All these circumstances probably gave rise to the 
 opinion prevalent among the vulgar in some parts of 
 the world, that the interior of our globe is the De- 
 vil's workshop, to which volcanoes are the chim- 
 nies. The bottom of the Mediterranean between 
 Sicily, the Lipari Islands and Naples, is covered 
 with volcanic substances : and Humboldt considers 
 
124 
 
 the Mountains of Quito, 700 square leagues, in 
 extent, one immense volcano, throwing out flames 
 at different cones. 
 
 The Origin of volcanic fire was formerly attribu- 
 ted to fermentation below the surface, which was 
 not only explained and illustrated, but a recipe for 
 making them composed. 
 
 If any of you wish for a volcano on a small scale 
 in your garden, take 25 Ib. of powered sulphur, and 
 as much iron filings, mix them into a paste with wa- 
 ter and place the whole in a large iron pot, covered 
 with a cloth, some little distance under ground. 
 In a few hours, from 9 to 12, the earth swells, heats 
 and cracks hot sulphurous vapours arise, and 
 the cracks enlarging, a brilliant flame bursts up, 
 thus forming a volcano in miniature, spontaneously 
 produced by the reciprocal action of water, iron 
 and sulphur. Thus spontaneous combustion was 
 supposed to arise from the contact of water with 
 iron pyrites, which contains both iron and sulphur. 
 A district in Dorsetshire (Eng.) abounding in 
 pyrites, after a heavy rain, in a hot summer, took 
 fire and burned for a long time. 
 
 Sulphur and Bitumen have been supposed t6 
 give rise to volcanic phenomena ; but though sul- 
 phur always is, bitumen has never been found in 
 
125 
 
 volcanic products. Monticelli has lately detected 
 free sulphuric acid, an important discovery. 
 
 The true cause of volcanic fire is probably not 
 to be sought for in the combustion of such inflam- 
 mables as we find on the surface of our globe ; but 
 in the chemical combination of elementary matter 
 composing mineral substances. 
 
 The existence of volcanic fire, then, is proved 
 by the fact itself, as appearing in volcanoes ; the 
 connection of volcanoes with each other, and with 
 earthquakes, proves its situation to be very far be- 
 low the surface ; the original cause of this fire, and 
 the reason of its breaking out occasionally with 
 greater vio!ence s are among those mysteries which 
 still continue to elude our grasp and will proba- 
 bly remain forever hidden from the knowledge of 
 mortals. 
 
LECTURE IV. 
 
 Minerals entering into the composition of Rocks 
 Different forms of Rocks Masses, Beds, Strata, JVb- 
 dides, Veins Internal Structure of Rocks Laminar, 
 Fibrous, Spheroidal, Prismatic, Veined, Cavernous. 
 
 Amygdaloidal, Aggregate, Granular, Porphvritic 
 
 Texture Fracture -Hardness Color Frangibilily . 
 Lustre Transparency Specific Gravity diction of 
 Acids. 
 
 Having cursorily glanced at (he present appear- 
 ance of our globe, and at the changes now going 
 forward, from various causes, on its surface, we pro- 
 ceed to examine the rocks that enter into its com- 
 position. Before entering upon a description of 
 them, it is necessary, however, to premise that a 
 knowledge of Mineralogy is in some degree essen- 
 tial to the study of Geology, of which it has been, 
 not unaptly, styled the Alphabet. Nearly all min- 
 eral substances are found either as constituents of 
 rocks, or as occasional substances imbedded in 
 them. 
 
 There are not many minerals entering into the 
 composition of rocks : The following enumeration 
 
127 
 
 is perhaps complete. For a knowledge of these 
 substances I must refer you to some treatise on 
 mineralogy and none is more deserving of com- 
 mendation than that of Professor Cleveland, of 
 Bowdoin College. 
 
 Clinkstone, 
 
 Compact Felspar, 
 
 Quartz, 
 
 Felspar, 
 
 Carbonate of Lime, 
 
 Mica, 
 
 Chlorite, 
 
 Talc, 
 
 Hornblende, 
 
 Actynolite. 
 
 Augite, 
 
 Serpentine, 
 
 Steatite, 
 
 Noble Serpentine, 
 
 Gypsum, 
 
 Iron, 
 
 Bitumen, 
 
 Pitchstone, 
 
 Chert. 
 
 A larger number of substances occur imbedded 
 in rocks, in such quantities as materially to alter 
 the character of the matrices, viz. 
 
 Garnet, 
 
 Olivin, 
 
 Cyanite, 
 
 Finite, 
 
 Spodumene, 
 
 Chiastolite, 
 
 Staurotide, 
 
 Epitode, 
 
 Mesotype, 
 
 Zircon, 
 
 Topaz, 
 
 Beryl, 
 
 Chrysoberyl, 
 Fluate of Lime, 
 Corundum, 
 Oxydulous iron, 
 Pyrites, 
 
 Chromat of iron, 
 Prehnite, 
 Andalusite, 
 Apatite, 
 ^phene, 
 Oxyde of tin, 
 Molybdena. 
 
 It is not too much to say that every variety of 
 mineral is found imbedded in, or connected with 
 some rock. 
 
128 
 
 Rocks in different positions assume different 
 forms ; which may be reduced to five, viz. 
 
 
 IRREGULAR MASSES, 
 
 BEDS, 
 STRATA, 
 
 NODULES, 
 
 VEINS, 
 
 Irregular Masses, may be of any size ; and often 
 constitute mountains, as is the case with granite, 
 serpentine, porphyry, and the overlying rocks, as 
 trap, &c. 
 
 Beds are of various sizes ; often running into ir- 
 regular masses : They are straight, or curved, and 
 frequently intersected by joints, so as to assume a 
 cuboidai appearance. Few rocks assume this form : 
 those most disposed to it are granite, porphyry, 
 syenite, and greenstone or hornblende. This dis- 
 tinction is considered, by Dr. Macculloch, as be- 
 ing practically the most easy, and perhaps the only 
 one necessary ibr the student. Beds and irregu- 
 lar masses often give out veins that penetrate the 
 adjoining rocks. 
 
 Strata have been confounded with beds, but they 
 
 r.o v [''' v ' ' . -/ -' '*r,'f? 
 
 are generally much larger, and usually are more 
 
 extensive in two dimensions than in the third : so 
 that strata may be considered as immense beds 
 with the upper and lower surfaces parallel, in most 
 
129 
 
 cases ; but occasionally meeting at a very acute 
 angle. Strata do not necessarily preserve the 
 same thickness, and often vary in the course of a 
 few yards ; nor are they always straight ; frequent- 
 ly being contorted and flexed into larger or smaller 
 curvatures, which may be either parallel or 
 transverse to the plane of stratalication. 
 
 This form of rocks is of various extent, some- 
 times being discernible only for a few hundred 
 yards, and at others being well defined for hun- 
 dreds of miles. Strata are found at all angles with 
 the horizon, and in all relative positions to each 
 other and the adjoining rocks. 
 
 A rock is not necessarily of the same modifica- 
 tion through the whole extent of a stratum, as the 
 texture may vary to the widest limits of fine 
 and coarse. 
 
 Strata never send off veins into adjoining rocks. 
 
 Nodules, or imbedded irregular masses, is a term 
 lately adopted to include rocks which are riot 
 stratafied nor disposed in pseudo strata (beds), and 
 which do not resemble in their connections other 
 large irregular masses. The forms of the Nodules 
 are various ; and they are usually imbedded in 
 the stratafied rocks ; but occasionally in granite. 
 The size varies from a foot to a mile. Limestone. 
 
130 
 
 Serpentine and compact Felspar alone have been 
 found of this rare division of form. 
 
 Feins are known by their filamentary forms, and 
 by intersecting all other forms of rocks and each 
 other. As this is an important subject and one 
 that has given rise to much Geological disputation, 
 it may be well to enlarge upon it ; premising that 
 the school of which Hutton was the founder, con- 
 sider veins to have been filled from beneath by 
 the action of fire : while the disciples of Werner 
 maintain that .they were filled from above by aque- 
 ous solution and infiltration : all acknowledging 
 that they occupy places or fissures originally open. 
 
 Veins are simple, or they exhibit branches or 
 ramifications : the latter are more generally met 
 with in Granite. 
 
 The size of veins varies from a mere thread to 
 several hundred feet in breadth, being smallest 
 usually in the primary rocks, and from one foot to 
 several miles in length. 
 
 The relative position of veins is extremely di- 
 versified, intersecting rocks in all directions, form- 
 ing every possible angle with the horizon, and 
 dipping to every point of the compass : the course 
 of a vein being straight or flexed. 
 
131 
 
 It has been observed that veins, except those of 
 quartz and calcareous spar, are limited to granite 
 and the overlying family, or the traps, syenite, 
 and porphyry. 
 
 Rock veins are often traced to some irregular 
 mass, though not in all instances. They may tra- 
 verse several different formations, and are always 
 different from the rocks they traverse. 
 
 Contemporaneous veins differ from true veins 
 in many particulars. The breadth is seldom more 
 than a few inches, the length varying from half a 
 foot to more than an hundred feet. The course is 
 scarcely ever straight ; and they give off many 
 branches. They are usually intimately connected 
 with the walls of the rocks in which they occur 
 sometimes passing into them insensibly differing 
 but little in composition, and often being one of the 
 constituents. Thus granite contains contempo- 
 raneous veins of quartz, of felspar, and of mica. 
 Gneiss affords them of the same substances. Mi- 
 ca slate, into the composition of which felspar 
 does not enter, contains veins of quartz, and 
 of mica, and of the two variously Wended. 
 They never traverse more than one bed or 
 stratum, and have no connection with any 
 other mass of the same substance. They seem to 
 
132 
 
 have been formed at the same time with the rock 
 in which they are found. 
 
 The walls of a vein are the sides of the rock 
 containing it, being in many cases the sides of the 
 fissure. The upper and lower walls are called 
 roof and floor, or pavement. The sides of many 
 veins are usually marked by thin layers of some 
 argillaceous substance. 
 
 Veins often intersect each other, and in some 
 cases have a regular structure, being filled with 
 different substances observing a parallelism and 
 the same order from both walls to the centre. 
 
 Cross courses are veins not being metalliferous 
 intersecting metallic veins. 
 
 Sometimes the body of a vein and the surround- 
 ing strata seem to have been fractured, and part 
 
133 
 
 of it to have fallen down, leaving the edges no 
 longer in continuity : this is called a shift of the 
 strata thus : 
 
 r- 
 
 Internal Structure. 
 
 The Internal Structure and the Texture oi 
 Rocks have been recently divided, and treated of 
 separately : the following are the different varie- 
 ties of structure. 
 
 Laminar : which may be divided into the lamel- 
 lar, foliated and schistose. 
 
 In the former division of this structure, a rock 
 divides more or less easily into plates, seldom con- 
 tinuous or allowing further division. 
 
 The lamellae are not necessarily straight, and 
 occur from a few lines to many yards in thickness. 
 They are sometimes divided by natural joints, and 
 then assume a prismatic a cuboid al figure. 
 
 There is a large and a small lamellar structure : 
 
 the former is seen in granite, the latter in horn- 
 19 
 
134 
 
 blende. This structure occurs in masses and veins. 
 
 The foliated structure occurs in the mixed rocks 
 only, and is defined to be " rather a tendency 
 to split into parallel lamina?, or an appearance of 
 parallelism in the disposition of the integrant mi- 
 nerals, than in the property of actual splitting." 
 
 Tne lamina? are irregular, and often curved : a& 
 is usually seen in foliated rocks. They are sel- 
 dom continuous or even; when they are, the 
 structure is passing into the schistose. 
 
 The schistose structure is evinced by the fisility 
 of the rock on the use of force : being rarely affect- 
 ed by the weather ; while foliated and lamellar 
 rocks are. 
 
 This modification of structure is found in simple 
 as well as aggregate rocks. The thickness of the 
 laminae is inconsiderable ; the length varies from 
 half an inch to several yards. They are sometimes 
 even and smooth, at others rough and nodular, 
 They are not necessarily straight. 
 
 This structure occurs only in strata. 
 
 The schistose sometimes run into the next divi- 
 sion of structure. 
 
 Fibrous is confined to argillite and limestone. It 
 is sometimes parellel, straight or curved. The 
 fibres sometimes diverge, presenting a ramified 
 appearance. 
 
135 
 
 Spheroidal comprises all varieties of concretiona- 
 ry structure. The concretions may be spherical, 
 touching only at points, the interstices being filled. 
 At times, by compression, they become ovate, and 
 assume irregular shapes. Sometimes they have a 
 radiated structure ; and sometimes contain a nu- 
 cleus. In some cases this structure is observable 
 only when the rock is weathered. 
 
 The size of the concretions seldom exceeds an 
 inch and is at times very minute. 
 
 In some cases this structure is confined to spots 
 in the rock, and then the concretions are large 
 and irregular. 
 
 Prismatic, including columnar structures. The 
 common prismatic is a modification of the large la- 
 minar, divided transversely by natural joints : be- 
 ing cuboidal or quadrilateral, seldom having a less 
 number of sides. 
 
 By the action of weather, or by partial decom- 
 position the angles are often rounded, so as to pre- 
 sent a spheroidal concretionary structure : which 
 is also caused by the desquamation of crusts. 
 
 In columnar structure there is no limit to the 
 number of sides, and the length is much more than 
 the breadth. In such instances as exhibit a very 
 short prism, the structure becomes tabular. This 
 structure is always aggregated. No instance having 
 occurred of a single column. 
 
 
136 
 
 The prisms are often seen in parallel ranges 
 forming a bed for some distance ; and sometimes 
 pass imperceptibly into the massive rock. When 
 parallel and upright, their beauty and regularity is 
 remarkable, and has given eclat to tfc Fingals Cave" 
 in the island of Staflfa. Parallelim is not necessary ; 
 since they are sometimes found diverging as from a 
 centre; occasionally in confused heaps, and again 
 dispersed and entangled, as it were, in the massive 
 or amorphous variety. Nor are columns always 
 straight ; being sometimes much bent in the same 
 direction, or in contrary directions, or mixed with 
 straight ones. 
 
 The prismatic structure occurs in veins as well 
 as beds. It does not necessarily exclude the small- 
 er kinds of structure, as the amygdaloidal and por- 
 phyritic. 
 
 The size of prisms varies from an inch or less, 
 in diameter, to several feet : in basalt they occur 
 occasionally 9 feet thick, in iron stone sometimes 
 the tenth of an inch. In length from 1 to 300 feet 
 or perhaps more. They occur with all number of 
 sides from 3 to 12. 
 
 Prisms are usually divided by irregular joints 9 
 destroying the appearance of continuity. The most 
 perfect and numerous joints are seen in the most 
 regular columns. Occasionally they are so frequent 
 
137 
 
 as to produce tabular prisms. The surfaces of 
 these joints are in close contact and may be plane 
 or concave and convex, presenting a ball and sock- 
 et joint. 
 
 Veined, comprises all those veins confined to one 
 rock, and which consist of the same substance as the 
 matrix. One or more veins may be found separate, 
 or confused in the mass and occasionally the same 
 appearance presented by the veins is observable in 
 a patch or spot at a distance from it. The size of 
 such veins differs from half an inch to a few feet 
 both in length and breadth. Their hardness usually 
 resists decomposition, and causes them to be raised 
 above the surface. Sometimes they are discerni- 
 ble on the fresh fracture, at other times not till the 
 matrix is in part worn away. They often intersect 
 each other, exhibiting a reticulated surface, show- 
 ing that in the interior of the rocks laminae cross 
 each other. Trap and granite are more frequent- 
 ly veined than other rocks. 
 
 Cavernous. When in the last mentioned structure, 
 the intervening walls or veins no longer appear 
 small, but constitute the greatest portion, it passes 
 into the cavernous, which is seldom seen on the 
 fresh fracture ; but frequently when the surface is 
 partially decomposed. The cells vary in size, 
 shape and frequency and are often filled with 
 
 
138 
 
 some substance different from the constituents of 
 the rock. This structure is often seen in sand- 
 stones and limestones. 
 
 Amyvdaloidal and the preceding are often found 
 in the same rock The caverns or cells are filled 
 with different mineral substances, appearing to be 
 imbedded. These vary in size and shape. 
 
 This structure is mostly confined to the over- 
 ly ing family, and to rocks of volcanic origin. 
 
 Aggregate evinces a composition of the fragments 
 of different rocks -as the breccia* and conglom- 
 erates and sandstones. The parts consist of one 
 or more rocks, with quartz united sometimes with, 
 and sometimes without, any apparent cement : the 
 size varying from a grain to several feet. The frag- 
 ments may be rounded or angular sometimes, but 
 rarely, both are found in the same mass. 
 
 Granular, also called crystalline, exhibits grains 
 of one or different minerals closely aggregated, as if 
 by confused crystallization, usually of small size. 
 It is difficult to be distinguished from the last variety. 
 
 Porphyritic, where crystals of one or more minerals 
 are included in a simple or compound base. The 
 size of the crystals varies from a mere speck to an 
 inch, or more. When the crystals disappear, or 
 the base is coarse granular, the structure chang- 
 es. It is connected with the amygdaloidal. 
 
139 
 Texture. 
 
 Under this term are arranged those modifications 
 in which the mass appears homogeneous, or consist- 
 ing of parts that cannot be separated. 
 
 It is in this way distinguishable from structure, 
 in which we see the component parts more or less 
 separated : so that the texture is in fact indica- 
 tive of the structure. In mineralogy the term is 
 familiar. It is not seen, except the rock be bro- 
 ken; and most of the circumstances arranged under 
 this head are also embraced by the terms fracture 
 and structure. 
 
 Granular does not denote that the rock may be 
 separated into grains : but is applied to its aspect. 
 This texture is not always the same. It is sandy 
 or arenacious, or is flat. The appearance may be 
 crystalline, or earthly. It passes into the crystal- 
 line, and fibrous and scaly textures. 
 
 Bladed. I do not remember to have seen this 
 texture. It occurs in hornblende and actynolite 
 schists, and arises from the interlacing of prisms, 
 passing from the granular texture to the fibrous. 
 
 Fibrous, arising from the condensed aggregation 
 of minute irregular prisms, more or less distinct. 
 
 The fibres are not always straight : but may be 
 curved, or radiating, or confused, for which modi- 
 
140 
 
 fications several names have been given, indi- 
 cative of the arrangement. 
 
 By the parallel position of minute scaly or gran- 
 ular particles, it passes into the scaly texture. 
 
 Scaly, in which the scales may be parallel or 
 confused, and more or less easily separated. 
 Usually the scales are minute; when not, this 
 texture, passes into the small lamellar structure. 
 
 Compact texture presents no appearance of 
 grains, and is considered as precluding all the pre- 
 ceding modifications. The various aspects it as- 
 sumes belong to the succeeding character. 
 
 Fracture. 
 
 By this term is understood the appearance of a 
 new surface of a rock, upon being broken. It de- 
 pends in a great degree upon the texture ; the small 
 fracture more particularly. There are several 
 modifications of fracture. 
 
 Even ; in which the surface is a plane, without, or 
 with a very small degree of curvature. 
 
 Uneven : in which the planes are variously in- 
 clined, and form by their angles, elevations and 
 depressions. When minutely uneven, with the ele- 
 vations and depressions considerable, it become? 
 granular, and forms a texture. 
 
 
141 
 
 Conchoidal. In this fracture one stitface is con- 
 cave, and the other convex, to a greater or less 
 extent, and frequently marked by curved lines, 
 more or less parallel. 
 
 There are several accidental varieties of this 
 fracture : two distinct concavities may occur, the 
 smaller within the larger, or there may be several 
 sm dl conchoidal appearances producing an undu- 
 lating surface. 
 
 These three varieties maybe united, or pass into 
 each other. They may also be united with some 
 of those that follow. 
 
 Splintery, is produced by wedge shaped scales^ 
 straight or curved, of which the thin edges are more 
 or less elevated, and occasionally transparent. 
 
 In the large splintery fracture, the scales are of 
 considerable breadth in proportion to their thick- 
 ness, and are flat or curved. It occurs frequently 
 in connection with the choncoidal. 
 
 In the small, when the splinters are very narrow, 
 they may exhibit something of a fibrous aspect :--* 
 when thick and short, something of a granular ap- 
 pearance. 
 
 Hackly fracture is rare occurring only in some 
 schistose rocks. It is known by the extreme sharp- 
 20 
 
142 
 
 ness of the protruding parts. It may be well seen, 
 by the transverse fracture of aggregated fibres. 
 
 The granular, fibrous, and scaly fractures are si- 
 milar to the textures with those names. 
 
 Hardness. 
 
 This character of rocks is so various that it is 
 impossible accurately to describe it. It ranges 
 from the hardness of quartz to that of chalk. 
 These extremes are well known, and the interme- 
 diate varieties must be tested by some equally 
 known standard; as the comparative ease with 
 which they are scratched by the point of a knife, 
 or the finger nail. To strike fire with steel is an 
 inadequate test, as that depends often on the form 
 of the fragments, and is frequently produced by 
 the intermixture of quartz. 
 
 Colour. 
 
 Among the external characters of rocks none va- 
 ries so much as colour and still it has often been 
 insisted upon as characteristic. 
 
 In some instances the colour is well defined, as 
 in limestone, serpentine, &,c. but in many cases 
 the tints are broken ; and those comprised un- 
 der the ceaseless changes of grey are the most pre- 
 dominant. Different colors are sometimes present 
 
 
 
143 
 
 in the same compound rock : and occasionally de- 
 pending on the colour of several substances united 
 in the mass. 
 
 Iron, in some of its conditions, is usually the agent 
 by which rocks are coloured. 
 
 The endless variety of colours affords a name 
 for every shade which may be found in rocks but 
 as the colour of the same rock frequently changes, 
 this character does not belong to the permanent 
 catalogue. Still it merits attention, as frequently 
 forming species which in economical purposes are 
 highly prized as in marbles. 
 
 Mr. Symes of Edinbugh has published a work on 
 colours wich deserves notice by those who wish 
 more particularly to attend to this character of 
 rocks or minerals. 
 
 Frangibility. 
 
 This character is very various, as some rocks 
 yield to a slight blow, and others resist a great 
 force. It depends in some measure upon the wa- 
 ter the rock contains, and the direction given to 
 the applied force. When the interior of a mass is 
 broken it is often frangible forthe time, but becomes 
 tough by exposure. To convey the proper idea 
 of the frangibility of a rock, it must be compared to 
 some familiar object, 
 
 
144 
 
 Lustre. 
 
 This character varies from that of plubmago, 
 the highest degree of lustre found in rocks, to that 
 of chalk, which is dull and earthy; in fact to the 
 total want of lustre. The shades are not very nu- 
 merous, and are often indefinite. The standard 
 however being fixed, a reference is easy and suffi- 
 ciently definite for common use ; thus there are six 
 degrees of lustre referred to, viz : the plumbaginous, 
 the silky, the resinous, the vitreous, the flinty, and 
 the waxy. The latter offers a double standard of 
 comparison, in its lustre, after having been melted, 
 and in the fracture it presents when broken. 
 
 Transparency. 
 
 The thin edge of a splinter of rock may trans- 
 mit a small degree of light, and be translucent, 
 but although transparency belongs to several min- 
 erals, it does not properly appertain to rocks. 
 
 Specific gravity. 
 
 This character is of little or no value in the com- 
 parison of rocks. When the weight of a rock is 
 Mentioned, the specific gravity ascertained in the 
 usual mode,. should be noted, so as to convey a dr 
 finite idea. 
 
145 
 
 Jiction of Adds. 
 
 In discriminating certain limestones, the action 
 of dilute nitrous or muriatic acid, by the extrication 
 of carbonic acid gas, is a convenient standard. 
 
LECTURE V. 
 
 Primary Rocks Granite Gneiss Mica Slate- 
 Jlrgillite Serpentine Limestone Quartz rock 
 Chlorite Schist Takose Schist Hornblende rocks 
 Jlctynolite Schist Porphyry Syenite. Identity of for- 
 mations Isochronism Alternation Loxodromism- 
 Character of Primary Soils. 
 
 All geologists agree in assigning an extreme date 
 to GRANITE and it is usually placed as the first, or 
 lowest of primary, and therefore of all rocks. It is 
 considered as unstratified : is one of the most 
 abundant, and most useful of rocks. It derives its 
 name from its usual granular appearance. 
 
 It is placed in irregular masses beneath all other 
 strata, occasionally sending veins into the adjacent 
 rocks. It seldom presents a definite form : but is 
 occasionally so divided by fissures as to make it 
 bear some analogy to stratification. When these 
 crevices or fissures are so placed as to produce a 
 prismatic figure, the angles are sometimes rounded 
 off, and an irregular spheroid is the result. 
 
 Granite sometimes presented a minute, but irre~ 
 gular prismatic structure, independant of the above. 
 
147 
 
 It is also occasionally minutely laminar, or exib- 
 liates in crusts, that are sometimes concentric, 
 sometimes flat ; in some cases appearing the result 
 of a concretionary structure in the rocks ; in others 
 as the consequence of atmospheric action. 
 
 The component parts of Granite are Quartz 
 Mica and Felspar: of these three substances I shall 
 give a brief notice not intending it however as a 
 precedent to be followed in describing the other 
 rocks : but to show the necessity for an intimate 
 acquaintance with mineralogy, previous to com- 
 mencing the study of Geology. It will also show 
 the connection between mineralogy and che- 
 mistry. 
 
 Quartz is a siliceous earth very plentifully distri- 
 buted. It is frequently limpid, but occurs of all the 
 tints of yellow, green, and red, derived from me- 
 tallic agents. 
 
 Its usual form is a 6 sided prism, terminated by 
 6 sided pyramids, more or less regular. Not un- 
 frequently it has metallic fibres running through it, 
 and then becoming more valuable, is cut and set as 
 an ornament. It has a great comparative hardness? 
 scratches and cuts glass ; and is not scratched by 
 steel. Before the compound blowpipe it melts in- 
 stantly. 
 
Quartz is the purest variety of siliceous earth, 
 containing about 69, and some even 96 per cent, of 
 pure silex. Rock crystal is quartz. It forms a large 
 proportion in the composition of calcedony, agates, 
 flints, jaspers &,c. It is also a constituent in many 
 gems : Opal and Cairngoram are nearly pure quartz. 
 Topaz, Hyacinth, schorl, and tourmaline, aven- 
 turine, emerald, beryl and garnet all contain large 
 portions of this earth. It is an important article in the 
 arts ; is used in the manufacture of glass, is an in- 
 gredient in the preparation of porcelain, and earth- 
 enware, and of smalt. It is used in the form of 
 sand, in all mortars and in agriculture, for the 
 improvement of certain soils. 
 
 Felspar is also widely distributed. It is a com- 
 pound substance, in which silliceous earth is in the 
 greatest proportion, frequently coloured by oxide 
 of iron. The following is the composition accord- 
 ing to 
 
 CHENEVIX. BRANDE. 
 
 Silex w-#T* : - 64. 
 Alumine - 24. 
 
 Potash . *'- 
 Lime ... - 6. 25 
 Oxide of iron - 2. 
 
 86. 25 
 
 - 
 
v 
 
 * >i^ 
 
 149 
 
 It is softer than quartz, and easily fusible. It is 
 usually red, grey, or white, with varieties. The 
 crystals are 4 and 6 sided prisms, bevelled, the 
 primitive form being a slightly obtuse rhomboid. 
 
 The extreme beauty of some varieties of feldspar 
 has occasioned its use in ornamental jewelry. Per- 
 sia, Arabia and Ceylon furnish the green variety, 
 which is much prized. On the coast of Labrador 
 it occurs very beautiful To Dr. Bigsby, we are 
 indebted for the knowledge of an extensive locali- 
 ty in the vicinity of Lake Huron. 
 
 Under the name of Petunze, it is used in the 
 manufactory of porcelain It was first employed by 
 the Chinese : is now extensively used by the 
 French at the celebrated Sevres, under the name 
 of decomposed feldspar and also by the English, 
 who have a valuable locality of it in Cornwall. It 
 retains its whiteness remarkably pure, from there 
 being no iron in its composition. By analysis 
 it yielded according to 
 
 VAU^UELIN. WEDGEWOOB. 
 
 Silex - --- 74. 
 Alumine - . ? i * 14. 05 
 - - 5. 06 
 
 Lime 
 
 
 95. 
 
 ---.---- 20. 
 60. 
 
 Loss and moisture - 20. 
 
 100 
 
 21 
 
150 
 
 The other ingredient usually noticed is Mica 
 a compound mineral, consisting of the earths, silex, 
 alumine, and magnesia, tinged with iron. Its color 
 is grey, passing into brown and black very rare- 
 ly, green and rose coloured. It is easily fusible 
 by the blowpipe. Its crystal is a rhomboidal prism; 
 < texture lamellar; It is easily divisible into ex- 
 tremely thin plates. It is scratched by the finger 
 nail. It yields by analysis 
 
 Silex > ; rf! 
 
 Alumine - 
 
 Potash :--K 
 
 Ox of iron 
 
 Maganese - 
 
 Water 
 
 97. 25 
 
 In Siberia and Russia this mineral is reguarly 
 mined and is an article of commerce, under the 
 name of Muscovy glass. Its flexibility has caused 
 its use instead of glass, in the Russian ships of war 
 as it is not liable to breakage by the discharge of 
 
 guns. Considerable quantities are exported : 
 
 200 puds being yearly sent to Lubec, and a large 
 quantity to England and Ireland. 
 
 These three substances, quartz, felspar and mi- 
 ca, are usually considered as the component parts 
 of Granite, and so they are, generally. But it is 
 a distinction not sufficiently correct for geological 
 
151 
 
 purposes. For instance, in a small space, ei- 
 ther the former or latter of these may disappear 
 and the latter invariably does in graphic granite. 
 Hornblende is sometimes a constituent, with all the 
 other three and sometimes usurps the place of 
 mica insensibly, and forms a compound of quartz, 
 felspar and hornblende; which is then called Sye- 
 nite. 
 
 Granite therefore consits of quartz, felspar, mica 
 and hornblende in different proportions. Other 
 minerals too sometimes enter into the compound 
 viz : actynolite, chlorite, talc, compact felspar and 
 steatite. 
 
 The size of the grains of granite varies from a 
 minute speck to several feet in length. It is so fine 
 as scarcely to be distinguished from sandstone, and 
 so coarse as to be almost a conglomerate ; and these 
 gradations may occur almost imperceptible in a 
 short distance. In one locality alone, Corsica, it 
 is orbicular. 
 
 The proportions of the ingredients vary much : 
 generally speaking felspar is the most, and mica 
 the least abundant. One of them, the quartz 
 particularly, may be altogether wanting >and in 
 some cases one of them may form large masses or 
 beds. 
 
152 
 
 The colours of granite are of almost every shade 
 that of the felspar, as it is the most variable, and 
 abundant, usually regulates the general tint of the 
 rock Dark red,yeilow and all varieties of gray 
 to black and green. 
 
 Quartz is next in quantity, and its whiteness as- 
 sists in forming the general hue of the granite it is 
 sometimes grey, smoky, and black. 
 
 Mica being either white, or brownish, or blackish, 
 modifies the colors of the compound causing grey 
 and black tints, which may also arise from horn- 
 blende. This mineral however, being almost con- 
 stantly blackish or dark green, contributes in pro- 
 portion to its quantity. 
 
 Sometimes each of the minerals may have a dif- 
 ferent color and occasionally, though rarely, 
 all may be crystallised. 
 
 The size and position of the different ingredi- 
 ents have given rise to several varieties. 
 
 Graphic Granite, is composed chiefly of quartz 
 and felspar, the latter forming a broad base, in 
 which the other is imbedded: when broken across 
 the rows of quartz, it resembles written characters, 
 and hence the name. Its decomposition furnishes 
 porcelain clay Kaolin. It is found on our own 
 Island. 
 
153 
 
 Globular Granite is composed of distinct concre- 
 tions. The most beautiful is from Corsica and Ar- 
 ran : not found in this country. 
 
 Porphyritic Granite is so called from the fineness 
 of its texture, which contains large crystals of 
 felspar. 
 
 Protogine arises from the substitution of talc, stea- 
 tite or chlorite for mica al ogether or partially. 
 
 Owing to the want of uniformity in the propor- 
 tions of the compound, granite has received new 
 and various names : thus when only two of the usual 
 constituents are present, imbedding some othersim- 
 ple mineral, it was called a Granitic aggregate. 
 Kirwan introduced specific names for these aggre- 
 gates ; they have however been abolished. 
 
 Granite, 1 have said is the oldest rock. It oc- 
 curs in mountain masses and apparently, in strata, 
 in veins, and in beds. It does not seem to have been 
 deposited at the same time. It forms the highest 
 as well as the lowest points that have been exam- 
 ined, and constitutes the summit and central part 
 of the highest mountains. In some instances it is 
 entirely hidden by the rocks superimposed. 
 When it forms the tops of mountains, the summit 
 presents a ragged and pointed peak. The high- 
 est locality in the world where granite has been 
 been seen indeed tue highest rock that has been 
 
154 
 
 examined is on the summit of Mount Blanc, or ra- 
 rather a few feet below the summit, whence I 
 brought these specimens in 1819: they are of the 
 variety protogine. 
 
 Mount Blanc in Savoy is the loftiest mountain 
 in Europe, rearing its majestic head 15,H8u feet 
 above the level of the sea: being three times high- 
 er than the highest point in the United States. 
 
 The relative height of Mount Blanc is greater 
 than that of Chimborazo, since it rises 1 1,530 feet 
 above the valley of Chamouny, while Chimborazo 
 is elevated but 1 1 ,2 >2 feet above the valley of Ta- 
 pia, making a difference of 300 feet relative height. 
 The upper f of this mountain of granite are within 
 the confines of perpetual snow. Rising above the 
 clouds, its summit enjoys the golden splendour of 
 the sun, but is cheered by no plant nor animal. 
 
 But seven times since its creation had the summit 
 been trodden by the foot of man previous to 18 1 9, 
 when I succeeded, in company with Dr Howard, 
 of Baltimore, and nine guides, in an attempt to 
 reach the highest point of Europe. After a jour- 
 ney of ^3 hours, 45 of which were passed in the 
 region of eternal ice, we returned to the beautiful 
 vale of rhamony. As our perilous and fatigueing 
 expedition, unfortunately added no scientific ob- 
 
155 
 
 serrations to those made by Saussure and others, 
 we abstained from obtruding on the public the re- 
 cital of our dangers or sufferings. 
 
 Many beautiful and valuable minerals occur in 
 granite, as 
 
 Garnet 
 
 Apatite 
 
 Actynolite 
 
 Cyanite 
 
 Pmite 
 
 Gabbronite 
 
 Spodumene 
 
 Idocrase 
 
 W erne rite 
 
 Corundum 
 Beryl 
 
 Anthophyllite 
 Andalusite 
 
 Pyrites 
 Oxidulous iron 
 
 Emerald 
 
 Stilbite 
 
 Sphene 
 
 Topaz 
 
 Jade 
 
 Oxide of Tin 
 
 Chrysoberyl 
 
 Fetstein 
 
 Lapes Lazuli 
 
 Epidote 
 
 Tourmaline 
 
 Graphite 
 
 Zi rcon 
 
 Schorl 
 
 
 Fluor spar 
 
 Tremolite 
 
 
 Many metals are found in granite either in 
 or in veins, or disseminated through the mass viz : 
 Tin, iron, tungsten molybdena, uranium, titanium, 
 manganese, arsenic, cobalt, zinc, lead, bismuth, 
 copper, silver and gold. 
 
 Granite contains neither coal, gypsum or salt. 
 
 It is the most durable of all rocks, and, as it 
 can be worked and polished, it is well suited for 
 architecture. The columns of the portico of the 
 Pantheon, the Ionic columns of the temple of Con- 
 cord in the Forum Romanum, and many others, as 
 well as the obelisks, in Rome, are of granite 
 brought from Egypt. 
 
GNEISS which is generally placed second on the 
 list of rocks, is also a compound of quartz, felspar 
 and mica. Its structure is usually slaty, while 
 granite is granular and this is supposed to constitute 
 the sole or surely the chief difference. It contains 
 more mica and less feldspar than granite. The 
 mica forms fluillets or small leaves between the 
 quartz and felspar and when Gneiss is divided, it 
 facilitates the operation hy its want of adhesion, 
 and shows itself in more abundance. 
 
 The composition always, and the texture often 
 assimilates this rock to granite. The following 
 are the points of Distinction. Crystals of mica and 
 hornblende in granite are mixed with the utmost 
 irregularity, but they preserve a paralell in Gneiss, 
 giving to it the foliated aspect. To describe the 
 modes >f aggregation would be to repeat what has 
 been said of Granite. 
 
 In some countries it is the most abundant of the 
 primary rocks, forming whole districts arid consti- 
 tuting high mountains of one entire mass. Its 
 strata are of various dimensions, generally thick, 
 unless alternating with quartz rock, mica slate, or 
 hornblende schist, when it becomes thin: particu- 
 larly when alternating with latter stratum, 
 
157 
 
 Gneiss is not always perceptibly stratified : when 
 intersected by veins of granite, it has many resem- 
 blances to an irregular granitic mass : when the 
 grains are very coarse, the resemblance to granite 
 is so strong as to confound the student. This is 
 more especially the case when the veins of granite, 
 run parallel with the laminae. 
 
 When there is no intermixture of granite veins 
 the stratification of gneiss is very regular. 
 
 Gneiss is subject to contortions of all magni- 
 tudes. It offers so many varieties of structure as 
 not to allow of specific descriptions : the granitic, 
 the schistose and the laminar are usually noticed. 
 
 Where gneiss and granite are in immediate con- 
 tact, the transition is scarcely perceptible by the 
 variety, magnitude and mixture of the particles, 
 until at length the fissile or foliated structure be- 
 comes apparent. 
 
 It is the next rock to granite, and occurs resting 
 or lying upon it. When they are both seen in the 
 same mountain, its ledge is always the lower of the 
 two. Mountains of Gneiss are seldom so steep as 
 those of granite, and the summits are not quite so 
 peaked. 
 
 Gneiss, like granite, has been formed at different 
 times and is found alternating with granite, with 
 
 serpentine, and with mica slate. 
 
 22 
 
158 
 
 The colour of gneiss varies in the same manner, 
 and from the same cause, as that of granite. 
 
 It is the repository of many minerals of which 
 the most usual are 
 
 Sapphire, 
 Ruby 
 Emerald 
 Beryl 
 Cats eye 
 Zircon 
 Chrysoberyl 
 
 Epidote 
 Garnet 
 Actinolite 
 Quartz 
 Feldspar 
 Hornblende 
 Fluor Spar 
 
 Carb. of Lime 
 Tourmaline 
 Melanite 
 Idocrase 
 Oxydulous iron 
 Cinnamon Stone 
 
 It also contains beds of limestone, hornblende* 
 porphyry, and anthracite. 
 
 It is the most metalliferous of all rocks contain- 
 ing all those found in the preceding in greater 
 quantity In Norway, Sweden, and Saxony, the 
 most important mines are in this rock. 
 
 It is used for the same purposes as granite, but 
 is neither so durable, nor so easily cut and polished. 
 
 Like its predecessors, Gneiss becomes irregular 
 in composition ; varying from the older kinds, in 
 which the component parts may be said to be dis- 
 posed into distinct curvilinear layers, to the newest 
 varieties, where the composition becomes more 
 diffused, and the layers thinner, the structure per- 
 fectly slaty, and the whole mass more fissile, when 
 it passes into the third primitive rock. 
 
159 
 
 MICA SLATE : composed of quartz and mica, 
 variously mixed, the latter usually predominating. 
 It differs from Gneiss principally in wanting feld- 
 spar as an ingredient and as the same ingredients 
 constitute Quartz rock, it passes into that also. 
 It also passes easily into Chlorite Slate and Tal- 
 cose Slate, and occasionally even into Argillace- 
 ous Slate, so much is its character sometimes mo- 
 dified by the admission of these minerals. The 
 colour is usally grey, derived from the shade 
 of the mica, as the quartz is almost always devoid 
 of color. It may be altered by the admission of 
 foreign substances into its composition. It is bril- 
 liant but easily decomposes. The older varieties 
 sometimes contain felspar. 
 
 Like other primitive rocks, it appears to have 
 been formed at different periods. 
 
 The strata are sometimes very thick, so as al- 
 most to seem unstratified. It is more slaty than 
 gneiss, and the layers not always straight often 
 flexed into contortions, sometimes without affecting 
 the stratum. It is occasionally split into plates 
 or slates. It is not decided if the laminar struct- 
 ure is or is not parallel to the plane of stratifica- 
 tion. 
 
160 
 
 The position of this rock varies as it alter- 
 nates with granite, gneiss and greenstone slate, in- 
 deed sometimes with argillite and limestone. Its 
 usual place is on gneiss covering granite. It gen- 
 erally forms large tracts of countries, and elevated 
 mountains, seldom high cliffs ; the hills are round- 
 ded at the summit, and are in long and beautiful 
 ridges, separated by moderate vallies. 
 
 It is remarked that this rock supplies the great- 
 est quanties of crystallised minerals among these 
 are. 
 
 Garnet 
 Tourmaline 
 Beryl 
 Schorl 
 Emerald 
 Corundum 
 
 Actynolite 
 Epidote 
 Andalusite 
 Kyanite 
 Phrenite 
 Apatite 
 
 P ynite 
 Oxydulous iron 
 Pyrites 
 Staurotide 
 
 It sometimes contains beds of limestone, ser- 
 pentine, hornblende, quartz, &c. 
 
 It abounds in ores, in beds and veins, more 
 particularly the latter. The mines of Saxo- 
 ny, Bohemia, Hungary, of Delicarlia and Fahlun 
 are in mica slate. 
 
 It will have been observed that mica slate and 
 gneiss are nearly allied to granite, and it was for- 
 merly supposed that the three constituted the pri- 
 mary class, and formed the primitive ridges of coun- 
 tries. I have mentioned they are the oldest rock 
 
161 
 
 and form the highest mountains. They are widely 
 distributed. No country is without them, though 
 they may not always predominate. 
 
 Where the laminae allow mica slate to split into 
 large tables, it is us.eful for fences and for many 
 domestic purposes. 
 
 The origin of granite has been a subject of warm 
 discussion to those geologists who regard theory 
 as the most important part of the study and it 
 has received different explanations from the differ- 
 ent schools. 
 
 The Wernerians regard it as a deposition 
 from aqueous solution, which was followed by the* 
 other rocks of the same class. They account for 
 granitic veins by a new deposition entering crevi- 
 ces and fissures of the original strata. 
 
 These granite veins are supposed by the Hut- 
 tonians, on the contrary, to have been elevated 
 by some power below; so that granite is the 
 latest, instead of the earliest rock, has been con- 
 solidated by heat, after the other depositions 
 were made, and forced up so as to be elevated, 
 with all the other strata resting upon it. to an in- 
 inclined and even vertical position. 
 
 This explanation does not agree with the local- 
 ity of many veins that can not be traced to any or- 
 iginal mass or mountain of which kind many 
 exist. 
 
162 
 
 The elevating by these means of such immense 
 masses of granite as mount Blanc and Chimborazo 
 appear scarcely credible. 
 
 As Geology became a subject of study and at- 
 tention, it was found that the three rocks already 
 mentioned, by no means constituted even the 
 greater number of the primary class. The most 
 important addition was Argillaceous Schist or 
 ARGILLITE: important for many reasons. It was ori- 
 ginally considered as appertaining to the next class 
 of rocks, and by being introduced here blends the 
 Primary and Transition as even those sections 
 of Argillite which are termed primitive are allowed 
 to pass imperceptibly into the transition. On this 
 account the arrangement of Macculloch seems 
 highly proper and I shall follow him in placing 
 under this head " all those schistose argillaceous 
 rocks, of the primary class, (in which he includes 
 the old transition,) however differing in texture ; 
 thus comprising the clay slate and the gray wacke 
 of some geologists." His reasons are sound, so far 
 as my observation or reflection goes. 
 
 In all cases, the coarser and finer varieties of 
 this rock occur as parts of one series, however 
 the one or the other variety may predominate in 
 particular instances. If fine beds or strata are 
 found without the coarser, or if the later are found 
 
163 
 
 without the finer, it offers no greater reason for 
 their separation than is offered for a similar division 
 of gneiss or mica slate by its coarse or fine textures. 
 These textures too occassionally present them- 
 selves in the same bed, either laterally or trans- 
 versely. Moreover, in the case of sandstone this 
 arrangement is adopted for similar reasons, no dis- 
 tinction being made between the fine and coarse 
 varieties, although the differences of conglomerates 
 and fine sandstones are much greater than is ever 
 met in Argillite. And why should not strata, mecha- 
 nically recomposed, be found among the primary, 
 as well as among other rocks. 
 
 The only differences that have ever been offered 
 between the older and newer varieties of this rock, 
 are negative. Such as the absence of nodules or 
 compact limestone, in the former; the want of 
 chiastolite, of numerous beds of greenstone, of 
 alum slate and drawing slate and even these 
 characters are so dubious that the most experi- 
 enced geologist may be at a loss, as Argillite fre- 
 quently shows all varieties in a small space. 
 
 The essential components of Argillite are the 
 peculiar indurated clay which alone forms all the 
 simple varieties, with mica and quartz The coarse 
 varieties, or greywackes, contain also primitive 
 fragments : felspar is sometimes found in it, giving it. 
 
164 
 
 a porphyritic appearance. These circumstances 
 produce different kinds of texture : the finer is 
 compact and uniform : other varieties occur from 
 the mixture of sand, gravel and mica. In the old- 
 er kinds, the mica is in large scales and assimilates 
 it to mica slate, while in the newer the mica be- 
 comes very small and fine. In the compact varie- 
 ties as hone slates &c. the union of parts is too 
 firm to be a mere mechanical adhesion : but gene- 
 rally indurated clay is the cement. 
 
 It passes into siliceous schist and into sand- 
 stone. 
 
 Argillite sometimes composes whole coun- 
 tries, but is occasionally only in small quan- 
 tities, alternating with other rocks in a very curi- 
 ous way. 
 
 On this continent it is found supporting im- 
 mense countries, as all the table land of St. Fee 
 de Bogota in Peru it rests immediately on an- 
 cient granite. Indeed the gradations are insen- 
 sible of granite, gneiss, mica slate and argillite 
 
 Thus a large country exhibits gneiss constantly 
 alternating between granite and mica slate : and 
 mica slate between granite and clay slate, whence 
 some geologists have been desirous of joining them! 
 as one formation : in the same manner that syenitei 
 and serpentine pass into that greenstone called? 
 
165 
 
 transition. In Cornwall it rests near to granite 
 
 In England it occupies large tracts, and is followed 
 in order by the secondary rocks. 
 
 Although it may be difficult to trace the outline 
 of the beds, the stratafication of argillite is not dis- 
 puted. In large tracts it is frequently of immense 
 thickness; but in alternations it becomes very thin, 
 in the same mariner as micaceous schist: and in the 
 same way too the strata are liable to contortions* 
 but seldom the rock itself! 
 
 The schistose structure of this rock renders it 
 valuable for many purposes, since it can be split 
 into lamina of almost any thickness, particularly 
 the finer varieties ; though often the graywacke 
 schists are divisible to the same extent. This ten- 
 dency is not necessarily, though it is generally 
 parallel to the plane of stratafication : it is some- 
 times oblique, but never in the secondary slates. 
 The finer varieties present sometimes a fibrous 
 structure. 
 
 Natural joints are sometimes transverse or ob- 
 lique to the plane of stratafication, forming rhom- 
 boidal or prismatic figures, more or less perfect. 
 Most frequently the intersections are made by 
 minute and numerous veins of quartz or calcareous 
 
 23 
 
166 
 
 spar, which in some rare cases follow the contor- 
 tions of the schist. 
 
 The following minerals occur in this rock. 
 
 Garnet 
 Epidote 
 Topaz 
 Opal 
 Cyanite 
 Chloiite 
 
 Wavellite 
 Staurotide 
 Andalusite 
 Chiastolite 
 Brown spar 
 Calc. spar 
 
 Lazulite 
 Tremolite 
 Stilbite 
 Oxydulous iron 
 Pyrites 
 
 Argillite contains numerous ores the hills of 
 Lima and Potosi, rich in metals, are of this rock 
 The copper and tin mines of Cornwall are in argil- 
 lite. 
 
 It contains beds of graphic and chlorite slates, of 
 talc, hornblende, greenstone, novaculite. 
 
 It has a few organic remains : which offer the 
 only strong reason why this rock should not be 
 classed among the prim.ary 
 
 It is abundant in this state. Large quantities of 
 it are annually brought' from Rensselaer county to 
 Albany and to this city. In the counties of Ulster 
 and Dutchess it occurs of such quality as to be wor- 
 ked advantageously. 
 
 Pennsylvania possesses it in Wayne county, in 
 Lancaster and in York, extending into Maryland. 
 These quarries yield annually about 1600 tons 
 worth 22 Dollars a ton. 
 
 It occurs near New Haven in Connecticut and is 
 extensively quarried at Charlestown, Mass. 
 
167 
 
 It has been traced by Dr. James and Mr. Eaton 
 about 30 miles on the Hudson. In the United 
 States it has an extent of about 400 miles North 
 and South. 
 
 The acclivities of Argillite are not very steep 
 and the soil yielded by its decomposition is better 
 than what is generally afforded by the primary 
 rocks. 
 
 These four rocks form the great divisions of the 
 primary class-but do not constitute it, as there are 
 many other important members of this series, which 
 were formerly treated of as subordinate beds. 
 Divisions in all branches of science are readily 
 made, but distinctions not so easily. In consider 
 ing them as distinct formations I am borne out by 
 the result of the observations of Humboldt and 
 Macculloch and no other authority need be cited. 
 The short portion of time allotted for this course 
 allows of no discussions, nor would they be profit- 
 able. I shall therefore proceed to an account of the 
 other members of the primary family. Some of 
 them are indeed very small, but not less important 
 in a geological point of view, 
 
 SERPENTINE, is a beautiful rock presenting some 
 shade of green mixed with white, yellow, brown or 
 
168 
 
 red ; and its name has been derived from the fanci- 
 ful arrangement of the colors, bearing some resem- 
 blance to the skin of a serpent. 
 
 Its surface is glossy, though dull, and offers to 
 the finger that saponaceous feeling, so peculiar to 
 all magnesian rocks and minerals, indicating the 
 presence of Magnesia. 
 
 It seems to hold the first place among these less 
 extensive members of the primary class in any ar- 
 rangement founded on the age of rocks, as it is not 
 unfrequently found resting immediately on granite. 
 
 It does not appear to be stratified, nor is there 
 any reason for supposing it to be so. It differs 
 from all unstratified rocks in having no veins run- 
 ning into the neighbouring strata. In Aberdeenshire 
 it is included in granite; but in Great Britain it 
 occurs mostly among gneiss, argillite, hornblende 
 rocks and limestone, and occasionally in mica slate. 
 It rests, forming the chief component of white- 
 stone, on ancient granite, in the Erzeberg. It is 
 occasionally covered by gneiss and sometimes by 
 mica slate. A small formation of it in Saxony rests 
 on gneiss, and is riot covered by any other rock. 
 In S?. America, on the mountains of Higuerote, it 
 occurs in a similar position. The large formations 
 of this rock are posterior to argillite. 
 
 With whatever rock Serpentine may be connect- 
 ed, it forms intimate associations. When in con- 
 

 169 
 
 tact with limestone, the two rocks frequently 
 blend. A gradation may be sometimes traced from 
 serpentine to hornblende, to which it is intimate- 
 ly connected. It has been observed that when 
 veins of trap pass through secondary limestone, it 
 is converted into serpentine during its passage, and 
 by an interchange of the imbedded minerals be- 
 longing to either, a gradation may be established 
 between trap and limestone. 
 
 It is sometimes connected with carbonate of lime, 
 and thus forms the beautiful marble called verde 
 antique. 
 
 The texture varies from highly crystalline to com- 
 pact and earthy. It is susceptible of a polish, and 
 is highly prized. The precious serpentine is in 
 small quantities, and is very beautiful. 
 
 Serpentine is the repository of many imbedded 
 minerals, some of which occur in such quantities 
 as materially to alter its character. The list fol- 
 lows : 
 
 Asbestos 
 Amianthus 
 Steatite 
 Diallage 
 Hornblende 
 Actynolite 
 Qjuartz 
 
 tremolite 
 Talc 
 Jade 
 Pyrope 
 Calc. Spar 
 Idocrase 
 Garnets 
 
 Chrysolite 
 Opal 
 Chromate of iron 
 Oxydulous iron 
 Lithomarge 
 
 It is seldom the gangue of metals In Cornwall 
 it is blended with native copper, and in Piedmont 
 it is associated with beds of magnetic iron. 
 
170 
 
 It is not an uncommon rock in Europe. It forms 
 the top of Monte Rosa, and of Pindus and of the 
 Appenines generally. 
 
 In this country it forms an insulated mass at Ho- 
 boken. At Rye, W. Chester, it occurs, and will re- 
 ceive a good polish. Near New Haven it is found 
 with large beds of lime stone, and is quarried ex- 
 tensively. At Westfield (Mass.) it is enclosed 
 in granite, in very small quantites. 
 
 PRIMARY LIMESTONE is a very interesting rock, 
 of which our information is not very accurate. It 
 is only by a close examination of the geological 
 position that it can be known as it bears a strong 
 resemblance to the secondary marbles and more 
 particularly to that portion usually called Transi- 
 tion, and thus offers another argument to Dr. Mac- 
 culloch for his wishing to embrace this latter class 
 in the Primary Rocks It is a remarkable rock, 
 composed almost entirely of calcareous matter. 
 
 The colours are so various as scarcely to be 
 subject of definition They are usually derived 
 from inflammable matter, from a mixture of other 
 substances or from iron. The most esteemed is 
 the white, which bears a fine polish, and is some- 
 times translucent. 
 

 171 
 
 It has been used for centuries for ornamental 
 purposes in sculpture and architecture. Many of 
 the noblest monuments of Grecian artists are in 
 marble. 
 
 The white marble of the Alps and of the Vallais 
 is highly prized. The grand cathedral of Milan is 
 built of primary marble from the Lago Maggiore, 
 as well as the suberb triumphal arch of Napoleon, 
 which his spiritless successor has left unfinished 
 a monument of his illiberally and want of taste. 
 
 I shall briefly notice a few of the more valuable 
 and rare antique and modern marbles ; though this 
 belongs more particularly to mineralogy. 
 
 The Parian marble of the ancients was snow 
 white, with the slightest possible tinge of yellow, 
 the grain fine, and when polished the appearance 
 was somewhat waxy. By exposure to air it har- 
 dened, and thus resisted decomposition for centu- 
 ries. It receives the most delicate touches of the 
 chisel, and retains them for ages, with all the soft- 
 ness of wax and the mild lustre of the original polish. 
 The finest Grecian sculpture that has descended to 
 us, is in this marble. The Venus di Medici- the 
 Venus of the capitol the Diana Venatrix the 
 Colossal Minerva, the recumbent Ariadne Juno 
 Capitolina, and Diana and the Stag, in the Louvre, 
 are all formed of this marble. 
 
172 
 
 The Pentelic marble, from mount Penteiicus, 
 near Athens, closeh resembles the preceding but 
 is more compact and of a finer grain. When the 
 Arts, at a very early period, had attained their full 
 splendor in the age of Pericles, the Grecians pre- 
 fered this marble to the Parian, probably because 
 it was nearer. The Parthenon was built entirely 
 of it as were many Athenian works, erected du- 
 ring the administration of Pericles, as the superb 
 temple of Ceres, or Eleusis. 
 
 Among other beautiful relics are the torso of the 
 Belvidere and the muses of the Vatican and in 
 Paris, a Bacchus in repose the throne of Saturn 
 and the tripod of Apollo. It was remarked by 
 Dr Clark that while the works executed in Parian 
 marble remain perfect, those finished in the pentelic 
 marble have been decomposed. 
 
 The marmo greco was obtained from Scio 
 and Samos, in the Archipelago. 
 
 The white marble of Luni on the coast of Tusca- 
 ny takes so fine a polish and so delicate a touch 
 that the Grecian artists latterly prefered it to all 
 others. The Antinous of the Capitol is of this mar- 
 ble, and the Apollo Belvidere, " the statue that en- 
 tranced the world." 
 
173 
 
 T he white marble of Carrara is of this formation. 
 The quarry was first opened by Julius Cresar and 
 it has ever since been highly prized. 
 
 Foreign marbles were introduced to a great ex- 
 tent among the Romans. Pliny, who wrote 1 66 
 years after the first importation of marbles, remarks 
 the rapid progress that had taken place in that 
 period, from a simple and unadorned way of life to 
 magnificence and extravagant expense. In the 
 reign of Diocletian, 240 years afterwards, the im- 
 portation of foreign marbles was discontinued, as 
 the columns employed in the baths of Diocletian 
 were taken from more ancient buildings. The 
 large and superb obelisk in the Circus Maximus of 
 Rome, was brought to the city after this period 
 however. Its removal from Egypt was began by 
 Constantine, and finished by his son. For remove- 
 ing this, it may be remarked, the largest wrought 
 stone ever moved in Europe,there existed sufficient 
 mechanical skill at that period, although the arte 
 connected with design had considerably declined. 
 
 The white marble of mount Hymmetus in Greece 
 the translucent white marble or Marmo Statua- 
 rio of the Italians the flexible white marble. 
 the roso antico the verde antico the giallo anti- 
 co the antique cipolin and the antique african 
 24 
 
174 
 
 breccia are among the ancient marbles of this for- 
 mation. 
 
 The red and white Tiree marbles, the lona marble 
 and the marble of Skye, and many others of Scot- 
 land The Mona marble of Anglesea and the 
 black marble of England; the Waterford, and the 
 Tipperary and the Kerry marbles of Ireland 
 the Languedoc and Campan of France the Si- 
 enna the mandelato the green marble of Flo- 
 rence the Verdi di Prado the Rovigo the Luni 
 -the Venetian the Laggo Maggiora, the Bretonico 
 and the Bergamo marbles of Italy the thousand 
 and one marbles of Sicily and generally speak- 
 ing, the marbles of Spain, of Portugal, Switzerland, 
 Germany, Norway, Sweden and Russia are of this 
 formation : as was the red marble of mount Sinai. 
 But we need not look abroad for primary mar- 
 bles. We have a locality of it at Kingsbridge ; 
 where it is coarse grained, and contains mica. 
 
 At Singsing is a much better and finer variety, 
 and one that deserves to be employed more exten- 
 sively. 
 
 The Schuylkill marble is extensively and deserv- 
 edly used in the arts 
 
 The Potomac breccia marble is susceptible of a 
 high polish, and is employed extensively the va- 
 
175 
 
 riety of color, and shape of the imbedded minerals 
 give it a beautiful appearance. The shafts of the 
 columns in the hall of Representatives in the Capi- 
 tol at Washington are of this breccia : they are 
 nearly 21 feet from base to capitol, and 2 feet in 
 diameter. A block of 70 feet long, with a base of 
 1 1 feet by 7 1 has been procured. 
 
 The quarries of New Milford about 3 miles from 
 New Haven, afford fine and beautiful marble sim- 
 ilar to the verde antique. 
 
 The Swanton marble (Vermont) is a superb and 
 excellent variety, and will eventually be much 
 used. 
 
 The Smithfield marble of R. Island is valuable. 
 
 The marble quarries of Massachusetts are the 
 most valuable in this country. 
 
 The West Stockbridge marble is much used 
 and produces to the owners about $30,000 annu- 
 ally. In Lanesborough about $10,000 worth is 
 yearly sold. The marbles of Berkshire sell for 
 about $40,000 and those of Sheffield for $8,000 
 yearly. 
 
 Primary limestone is found in strata, of all forms 
 and magnitudes also in nodules or large irregu- 
 lar masses, in gneiss, and in veins, when it is crys- 
 talized. In the Pyrennees, it is considered by 
 Charpentier as an independent formation. In South 
 
176 
 
 America it is found, coarse grained and white, simi- 
 lar to the finest Carrara, which Humboldt for a 
 Jong time thought an independent formation. In 
 the Pyrennees and in the Alps it is common, but in 
 America, beds of it, subordinate to rocks of 
 granite- gneiss, are more rare. 
 
 In Scotland it occurs in granite; when it is as- 
 sociated with mica slate or gneiss, the mica enters 
 into its composition and gives it a laminar struc- 
 ture. The beds usually follow the direction of 
 the accompanying rocks. 
 
 The following minerals, with others, are found 
 in limestone : 
 
 Serpentine, 
 Steatite, 
 Garnet, 
 Emerald, 
 Beryl, 
 Spinelle, 
 Titanite, 
 Sphene, 
 
 Stilbite, 
 Olivin, 
 Idocrase, 
 Tabular Spar, 
 Tremolite, 
 Sahlite, 
 Augite, 
 Hornblende, 
 
 Actinolite, 
 Asbestos, 
 Mica, 
 Talc, 
 Chlorite, 
 Quartz, 
 Brown Spar, 
 Pyrites. 
 
 QUARTZ ROCK has been established as holding 
 a place among the primary rocks. Dr. Maccul- 
 loch, Humboldt, and Von Buch first gave us cor- 
 rect ideas of it. 
 
 It is generally white, with a smooth, brilliant 
 surface, or is tinged with reddish, yellowish, or 
 dark purple tints. 
 
177 
 
 Its aspect is usually granular the size of the 
 grain varying: rarely is compact or crystalline. 
 In its purest state it has different aspects : thus, in 
 some cases, it has a granular, crystali.ed appear- 
 ance : in others, the texture is a mixture of the 
 mechanical and chemical : and again, it is purely 
 mechanical. The cavities may contain regular 
 crystals. 
 
 When much blended with felspar, it takes the 
 reddish tint of that mineral, and the texture be- 
 comes changed, so as to exhibit a mere agglutina- 
 tion of grains of different sizes, and in different 
 proportions. It has a foliated disposition, and the 
 laminae are easily separated into very thin plates. 
 
 This rock is sometimes found to contain mica, 
 particularly when resting on mica slate, and is 
 split into laminae of such thicknes, as to allow of its 
 being used for architectural purposes. 
 
 A simple quartz rock 1800 feet thick exists at 
 an elevation of 1600 feet above the sea in South 
 America. 
 
 Like the primary rocks, with which it is in con- 
 nection, it is stratified ; the distinctions of beds be- 
 ing as decidedly marked in some cases as in sand- 
 stones. The dimensions vary from an inch to ma- 
 ny yards ; and having natural joints, they break 
 into rhomboidal or prismatic fragments. 
 
178 
 
 It has no certain position, being occasionally 
 found alternating with all the primary strata. 
 When alternating with gneiss the limits are scarce- 
 ly discernable, as the felspar becomes gradually 
 more abundant, and the other components less. 
 When alternating with mica slate, its beds are very 
 thin, and the mica insinuates itself into the mass 
 thus producing a very gradual change, so as to 
 render doubtful the line of demarcation. This is 
 not always the case, for when they alternate in 
 large beds, the outlines are much more decided. 
 
 Quartz rock alternates with argillite also, in la- 
 minae of various dimensions ; generally on a small 
 scale. In some cases, they almost insensibly glide 
 into each other; in others their separation is very 
 distinct. It alternates also with greywack schist ; 
 and sometimes, says Dr. Macculloch, with primary 
 sandstone, which it strongly resembles, but always 
 on a larger scale. 
 
 M. Von Buch remarks that in Scandinavia the 
 primitive clay slate is sometimes represented by 
 quartz rock, thus making them geognostic equi- 
 valents. 
 
 In South America, the quartz rock has been 
 examined by that indefatigable observer, Hum- 
 bold t. He found this formation containing alter- 
 nating beds. 1 auriierous quartz. 2 chlorite 
 
179 
 
 slate. 3 auriferous quartz and tourmaline. 4 
 auriferous quartz and specular iron ; and some of 
 these beds are 1000 feet thick. It is to the destruc- 
 tion of these beds that some suppose we are origi- 
 nally indebted for piatina, gold and diamonds, and 
 also for the topaz and euclase of Brazil. 
 
 Some English geologists have denied the right of 
 quartz rock to a separate place ; and chiefly be- 
 cause there is so small a quantity of it in Europe : 
 But in America it decidedly takes rank a locality 
 of it is seen running from Canada, through Ver- 
 mont, Massachusetts and part of New-York, an 
 extent of more than 300 miles. 
 
 At Brighton, near Boston, it occurs of various 
 colours. 
 
 It contains few imbedded minerals : garnet, 
 hornblende, titanite and oxydulous iron occasion- 
 ally occur. 
 
 CHLORITE SCHIST has only lately been deemed of 
 such importance as to be called a rock. 
 
 It is of a greenish color, passing into grey, and 
 into the pale grey of the micaceous schist. The 
 | greenish specimens have the most lustre. 
 
 It does not form very extensive tracts of coun- 
 try, but is sufficiently well marked in its charac- 
 
180 
 
 actersto induce the best geologists of the present 
 day to assign it a distinct name. 
 
 It is so nearly allied to micaceous schist, with 
 which it is intimately associated, that some geolo- 
 gists have doubted the propriety of a separation. 
 It alternates also with gneiss, and by insensible 
 degrees enters into that rock. With mica schist, 
 argillite, gneiss and primary limestone it forms a 
 very interesting geological series in Scotland. 
 
 V* hen the beds are thick, it is strongly assimi- 
 lated to mica schist, is flexed and is imperfectly di- 
 visible. It is more generally the case that the 
 strata are thin, when it is more easily split into 
 laminae, but is seldom applicable to economical 
 purposes. 
 
 In texture, it partakes of the characters of the 
 rocks with which happens to be most intimately 
 united at the locality as micaceous schist, gneiss, 
 argillaceous schist. It never contains fragments 
 of other rocks. 
 
 The essential constituents are quartz and folia- 
 ted chlorite, which is to be distinguished from 
 scaly chlorite. The green tint of the former is 
 the most convenient character by which to dis- 
 tinguish it from mica, and from micaceous schist. 
 
181 
 
 Other minerals occasionally enter into its com- 
 position, as felspar, hornblende, mica, actynolite 
 and compact felspar. 
 
 The imbedded minerals are usually crystallized 
 chlorite, quartz, oxydulousiron, tourmaline, brown 
 spar and pyrites. 
 
 East of Troy chlorite schist occurs in strata be- 
 tween two and three miles wide, and sometimes 
 rising into hills 200 or 300 feet high. 
 
 On the Milford Hills, in Connecticut, it is found 
 in strata between primary limestone and horn- 
 blende ; and at West Haven, it forms extensive 
 strata, passing perhaps into argillite. 
 
 TALCOSE SCHIST is another rock that has* 
 only been lately spoken of separately in geology 
 and it is to the observation of Macculloch that this, 
 as well as the last rock, owes its elevation. 
 
 It is similar to the preceding rock, being com- 
 posed of talc, or talc and quartz, with an occasion- 
 al, though rare, intermixture. Its colors are white 
 lead grey and dark obscure green. The pecu- 
 liarities of talc sufficiently distinguish it from other 
 
 rocks. 
 It is not common, nor abundant but alternates 
 
 very distinctly, as a rock, with other primary 
 
 strata. The constituents of chlorite or micaceous 
 25 
 
182 
 
 schist give those rocks a very different character 
 from the present. 
 
 The strata are usually thin ; and it might have 
 been retained as a simple mineral did it not occa- 
 sionally show itself in large masses. 
 
 Associated with hornblende schist, it often forms 
 thin beds in a series of gneiss. It is often formed 
 by an imperceptible passage from micaceous 
 schist : sometimes too from chlorite schist ; and 
 occasionally from argillaceous schist. In all these 
 cases, the two first particularly, it is associated with 
 minerals having an affinity to talc, as steatite and 
 asbestos. It is also associated with serpentine. 
 It presents no structure particularly to be noticed : 
 it is sometimes minutely undulated, but not flexed 
 like micaceous schist. 
 
 It contains the following minerals. 
 
 Asbestos, 
 
 Actynolite 
 
 Cyanite, 
 
 Diallage, 
 
 Automalite, 
 
 Staurotide, 
 
 Chromate of iron. 
 Pyrites. 
 
 Perhaps the regular strata of talc, described by 
 Professor Hall, as occurring in Windham, Ver- 
 mont, is Talcose Schist. 
 
 HORNBLENDE Rocks have given rise to much dis- 
 cussion in Geology, and are variously viewed by 
 different Geologists. 
 

 183 
 
 Brochant arranges under this head greenstone, 
 greenstone porphyry ,, and verd antique. 
 
 Bakewell considers Trap as a generic term, 
 embracing greenstone, basalt, amygdaloid and 
 whinstone. 
 
 Eaton includes primitive trap, sienite, green- 
 stone porphyry and green porphyry under the 
 Hornblende Rocks. 
 
 Macculloch, under Hornblende Schist, speaks of 
 hornblende rock, primitive greenstone, and green- 
 stone slate. 
 
 When hornblende becomes slaty in its structure, 
 it is usually termed Hornblende Slate. 
 
 When intermixed with felspar, it is then Green- 
 stone. The proportions of the two ingredients are 
 different; but the hornblende usually predomi- 
 nates and gives the greenish tinge. If this variety 
 become slaty it is called Greenstone Slate 
 
 Hornblende rocks are not always composed of 
 but two constituent parts : sometimes admitting in- 
 to the compound quartz, mica, talc, lime and iron, 
 which latter decomposes by the action of air, and 
 disintegrates the mass. Epidote is occasionally 
 present in these rocks, which are then susceptible 
 of a fine polish. When the felspar is in crystals it 
 is called porphyrytic greenstone ; and this variety, 
 when very dark and fine, was called by the an- 
 
184 
 
 cients Black Porphyry. The green porphyry of 
 the ancients is very compact, and embraces crys- 
 tals of felspar. It is often colored by epidote. 
 This is found near Boston. 
 
 Greenstone beds are occasionally very large, 
 forming mountains, usually conical, with mural pre- 
 cipices. It is not confined to the primary class. 
 
 In this country it is common. It forms the sum- 
 mits of all mountains between the primary range 
 and the Hudson. The Palisades are of this rock; 
 as is Mount Holyoke, in Massachusetts, where the 
 columns are from 60 to 100 feet long, articulated 
 like basalt. In Maine, on the Kennebec, it also 
 occurs. 
 
 Dr. Macculloch terms them all Hornblende 
 Schist, on the supposition, that the other rocks, 
 usually called hornblende, are but subordinate 
 parts of the great beds, having the schistose struc- 
 ture and that the structure varies from massive 
 to schistose in the same bed. Hum bold t thinks the 
 independence of greenstone slate doubtful. 
 
 Hornblende Schist rarely forms extensive tracts, 
 without alternating with other primary strata. 
 
 Its most intimate association is with gneiss, in 
 moderate and thin strata, so as almost to form a 
 subordinate bed, but in other cases to equal it in 
 quantity and importance. It follows the flexures 
 
185 
 
 of gneiss and is penetrated by the same veins of 
 granite passing however into gneiss by the ac- 
 quisition of quartz, and alternations of horn blende. 
 In the same way it also alternates with, and in- 
 sensibly runs into micaceous schist ; in which it is 
 usually accompanied by chlorite schist, presenting 
 sometimes a prismatic structure. It is not often 
 associated with argillaceous schist, but is occasion- 
 ally, when it also passes gradually into that rock. 
 It passes into Actynolite schist, which is erected 
 into a separate rock. 
 
 It often presents minute undulations, like mica- 
 eous and chlorite schists, besides following the 
 large flexures of the laminar varieties. 
 
 The texture varies according to the component 
 parts but the granular, crystalline, and laminar 
 are the most common : in the latter case being 
 fissile ; in the former, massive (being the horn- 
 blende rock of many.) 
 
 It has not been found to contain fragments of 
 other rocks, and its texture may be set down 
 as truly crystalline or chemical. 
 
 Its components are felspar arid hornblende,often 
 the latter alone: thus differing from micaceous 
 and chlorite schists, which always contain two 
 minerals, one of them essentially quartz. Mica 
 
186 
 
 and Chlorite only are very rarely contained in 
 such quantities as to alter the genuine rock. 
 
 The color is black or a green so dark as not to 
 be distinguished from it. The colour of the fel- 
 spar produces varieties of shade, as it approximates 
 white, green, or red. 
 
 Pyrites and garnet are the only minerals found 
 in this rock the latter sometimes very abundant. 
 
 It is used for building stone, and in the prepara- 
 tion of water proof mortar. 
 
 ACTINOLITE SCHIST is mentioned by Macculloch 
 as a distinct rock; thus following, as he remarks, 
 the ideas of Saussure, who asserts that it occurs 
 in gneiss, under a distinct character. It is dis- 
 tinct from chlorite schist. In all its associations it 
 is similar to hornblende schist, with the exception 
 of a more intimate connection with chlorite schist. 
 It differs from hornblende schist in composition 
 only by the substitution of actynolite for horn- 
 blende. It is to be remarked, that while actynolite 
 continues to be considered as a distinct species 
 from hornblende, so long must the two rocks be 
 separated. 
 
 At Brunswick, Maine, it forms a stratified rock 
 of considerable extent, associated with granular 
 quartz. 
 
187 
 
 PORPHYRY has been placed among the primary 
 rocks, though Humboldt doubts its existence as 
 such, unless in subordinate beds in the same 
 way that gneiss and mica slate of the high Alps, 
 become granular, and, from the insulation of fel- 
 spar crystals, assume a porphyritic aspect. He 
 considers porphyries as more closely connected 
 with coal-sand-stone. 
 
 Porphyry has a compact base, containing crys- 
 tals distinctly visible, chiefly of felspar or quartz, 
 the base forming the specific term, as compact fel- 
 spar, or clay stone, pitch stone, or clink stone. 
 
 Its color is reddish, brown, purplish, or green. 
 Its general appearance is not unlike granite. 
 
 Felspar porphyry is found near Boston, and 
 equals in beauty the antique varieties. The base 
 is compact felspar, and has been mistaken for jas- 
 per. It is occasionally slightly granular, or a 
 little foliated. The fracture is usually conchoidal, 
 somewhat splintery or uneven. It gives fire with 
 steel. When the crystals of felspar decompose, 
 small cavities are produced: even the base is 
 liable to decomposition, but is protected from the 
 action of air and moisture by being polished. It 
 is often susceptible of the finest polish, and has 
 been much employed in the arts. It is very du- 
 
188 
 
 rable, and was highly prized for architectural pur- 
 poses by the ancients. The extreme hardness 
 alone of porphyry and granite has caused their 
 neglect. It should not form an objection. Inde- 
 pendent nations who build not in fear of revolu- 
 tions should have durable materials. 
 
 'Some of the most beautiful ornaments of Rome 
 are of this substance ; the urn of Constanza, and 
 theurnof St. Helena are each formed from a large 
 block of porphyry: and the great tazza,or saucer 
 shaped reservoir in the rotunda of the Museo Pio 
 Clementino is one immense piece of porphyry. 
 Pliny says that the sculptors began to use porphy- 
 ry under Claudius. The room in which the prin- 
 ces of the Greek empire were born was encrusted 
 with it : and these princes were called Porphyro- 
 geneti. The name of this stone was taken from 
 the ancient purple dye made of the Tyrian shell 
 fish called porphyrios, whence it is supposed that 
 the ancient dye was of this dull red colour. 
 
 There is a small grained greenish porphyry, 
 more highly prized than the red variety. 
 
 SIENITE is another, and the last of these rocks. 
 By the substitution of one ingredient for another, 
 granite is so insensibly converted into sienite, thaf 
 
189 
 
 at first sight it does not strike us. Thi is effected 
 by the existence of hornblende in the granite, 
 which becoming more abundant, at last supplies 
 the place of quartz, and forms a compound of 
 which hornblende and felspar are the two constant 
 and essential constituents : but in which mica and 
 epidote may occasionally blend. Felspar is usual- 
 ly the most abundant, and occasionally the horn- 
 blende is in very small quantities. The necessary 
 presence of hornblende as an ingredient, distin- 
 guishes this rock from granite in which hornblende 
 is imbedded. 
 
 It derives its name from Siena in Upper Egypt, 
 where it abounds, and whence it was brought in 
 great quantities for employment in architecture 
 and sculpture, by the Greeks and Romans. 
 
 Its structure is granular and sometimes slaty. 
 
 The color varies with the predominating consti- 
 tuent ; the hornblende often gives it a greenish 
 tinge, as does epidote : fie felspar is mostly red- 
 dish, or whitish. When there are large crystals 
 of felspar contained in a fine grained sienite, the 
 mass is termed Sienitic Porphyry. It will have 
 been observed, that sienite and greenstone are 
 both composed of felspar and hornblende. They 
 are in fact the same rock varied by a transition so 
 
 gentle as to be imperceptible : thus, granite 
 26 
 
190 
 / 
 changes into sienite, which runs into greenstone : 
 
 "but that section of the chain in which hornblende 
 predominates is greenstone, and where felspar is 
 the most abundant, it is sienite. 
 
 This rock is occasionally associated with all the 
 primary rocks, resting on granite, gneiss, and ar- 
 gillite and alternating with all the lesser members 
 of this family. 
 
 It is not an abundant rock. 
 It is plentiful on the west shore of Lake Cham- 
 plain. 
 
 In many places in Massachusetts it is so abun- 
 dant as to be quarried. The Stone Chappie 
 in Boston, the State Prison at Charlestown, and 
 the prison at Lechmere Point are of this stone. 
 The two celebrated lions at the steps ascending 
 the Roman C apitol are of sienite ; as is also the 
 famous Collosal Egyptian Head in the British 
 museum. 
 
 Humboldt doubts if it ever occurs as a primary 
 rock, except as a subordinate bed, or as an indepen- 
 dent primary formation. Such he thinks are some 
 sienites resting on gneiss, and partly covered by 
 primitive mica slate. He mentions the Sienite of 
 Paramo, placed on granite and covered bv slate. 
 
191 
 
 These are the substances usually treated of in 
 Geology, under the head of Primary Rocks : to 
 them Humboldt has added " EUPHOTIDE," a variety 
 of serpentine rock ; or a mixture of diallage and 
 lamellar felspar. It is the Gabbro of de Buch. It 
 seems to be most intimately connected with mica 
 slate and hornblende schist. 
 
 All these rocks are not necessarily present in 
 every primary country : i. e. they do not univer- 
 sally hold the same position, since part of them 
 may be absent. Indeed we have been taught dur- 
 ing the last twenty years, as M Humboldt says, 
 that we are not to expect precisely the same rela- 
 tive position in the constituents of the great forma- 
 tions. The great laws, however, regulating the 
 succession of rocks, in the structure of the globe, 
 are in all countries the same ; and striking analo- 
 gies in the position, composition, and included or- 
 ganic remains of contemporary beds exist univer- 
 sally : and viewing formations in a general way we 
 are almost taught to believe their universal identi- 
 ty. But identity of formations is not to be looked 
 for, any more than the constant operation of the 
 same law in mechanics. Like causes produce like 
 effects but obstacles may present occasionally 
 to interrupt them thus occasionally one rock 
 may represent another : in which case there is not 
 
192 
 
 an identity in all formations, but parallel forma, 
 dons, or geognostic equivalents. Nor in comparing 
 widely distant countries, are we to look in one 
 country for an equivalent for every rock in the 
 other, as one formation may represent many others. 
 Thus the beds of clay below the chalk, in France, 
 may be easily separated from oolitic limestone ; 
 but in our hemisphere, South of the Equator, they 
 have marl for geognostic equivalents to represent 
 them. And these beds, by the way, may in the 
 same manner, represent the chalk in the United 
 States. 
 
 The striking similarity of structure in different 
 countries has been examined and acknowledged by 
 the best geologists : thus the position and succes- 
 sion of formations has long been a subject of study 
 to Humboidt; (whom I liberally resort to) and in 
 South America he soon recognised the conformity 
 of superposition in the two continents, and found 
 them fully develloped in the formations exhibited 
 from the 21 N. Lat. to the 12 S. Lat.- where he 
 says the types were rather enlarged than altered. 
 From the Canary Islands to within the polar cir- 
 cle (as far as the 71 N. Lat.) we have undoubted 
 testimony oi the uniformity of position, and of the 
 analogous features that characterise formations in 
 the most distant regions. 
 
193 
 
 The associations of rocks, upon comparing im- 
 mense fields of observation, we may say, are near- 
 ly as constant as their composition. The com- 
 pounds are made up of the same simple minerals, 
 and in turn compose mountain masses, in which 
 the same rocks are found in a similar position. 
 
 This uniformity of position is observed usually 
 in rocks of all formations but more particularly 
 in the larger, or older, as in the Primary and Secon- 
 dary : it does not follow that it is found in inde- 
 pendent formations. These independent forma- 
 tions are so called from the fact, that they rather 
 escape the law of uniformity of position, being 
 placed indiscriminately on granite, micaceous 
 schist, and secondary limestone. The position of 
 independent formations however does not neces- 
 sarily exclude uniformity of position. 
 
 It has been doubted by some whether the same 
 rock was deposited at the same time in different 
 parts of the globe. Most Geologists assign the 
 same date to a deposit wherever it may be found : 
 this is expressed by the term Isochronism of forma- 
 tions. Formations of analogous composition are al- 
 lowed to have been produced at different and dis- 
 tant periods these however are formations not in- 
 cluded in this general law as Primary and Se- 
 
194 
 
 eondary Limestone. Organic remains go far to 
 prove this Isochronism, and the existence of the 
 same fossi's in similar though distant beds affords 
 strong proofs. 
 
 " It has more than once been desired that we 
 could find a supplement to our short annals in 
 the monuments of nature. The historical ages 
 might, however, have sufficed to teach us, that the 
 succession of moral and physical events is not re- 
 gulated by the uniform process of time, and cannot. 
 in consequence, furnish its measure. We see, in 
 looking back, a succession of creations and dis- 
 tinctions, by the various arrangements of beds 
 that form the crust of our globe. They give us an 
 idea of several distinct epochas : but these 
 epochas, so fertile in events, may have been very 
 short, compared to the number and importance of 
 the results. Between the creations and destruc- 
 tions on the contrary, we see nothing, whatever 
 might be the immensity of the intervals ; there 
 every thing is lost in the mist of indeterminable 
 antiquity, the degrees of which cannot be appre- 
 ciated, because the successsion of phenomena has 
 no scale that can be referred to the division of 
 time." (Mem. de 1'Institute, 18J5.) 
 
195 
 
 I have mentioned that several of the rocks we 
 have described, alternate with others, with which 
 they are associated. When the same rocks are 
 placed several times alternately upon each other, 
 they are said to alternate, and it is often by this in- 
 terchange of places, that they insensibly become 
 blended and run into each other. Thus when two 
 formations succeed each other immediately, it 
 generally happens that beds of the one begin at first 
 to alternate with beds of the other, until a new 
 formation succeeds without any subordinate beds. 
 
 In primary rocks the three most ancient are 
 said to be either insulated, or alternating two and 
 two, or all three alternating together. Granite and 
 gneiss in some cases are constantly associated, in 
 others gneiss and mica slate. In all cases there 
 are certain laws ; granite, gneiss and mica slate 
 are found in a triple association ; but granite al- 
 ternating with mica slate only, or gneiss and mica 
 slate alternating with argillite only, are said not to 
 occur. Those rocks passing insensibly into others 
 with which they are in contact must not be con- 
 founded in this way as micaceous schists that 
 oscillate between gneiss and argillite, are not 
 to be confounded with such rocks as alternate, 
 and preserve distinct all their characters. 
 
196 
 
 In treating of mountains, I have mentioned their 
 usual direction as being frequently the same. 
 
 The parallelism of beds, called also Loxodrom- 
 ism, is very surprising. The primary beds on the 
 coast of Genoa, the plains of Lombardy the Alps 
 of St. Gothard Swabia and the north of Ger- 
 many, were first noticed by Humboldt to run almost 
 constantly from south west to north east and this 
 was one of the reasons that led him to South Ame- 
 rica, where he noticed the same in the chain of 
 mountains running from the lower Oronoko to the 
 basin of the Rio JSigro, and the Amazon. This 
 Loxodromism has already been mentioned in 
 speaking of the uniform direction of mountains 
 from north east to south west. 
 
 This is the direction of our Allegany Mountains, 
 one of our most interesting geological features. 
 From the sources of the St. John River, New 
 Brunswick, it runs south west to the junction of the 
 Alabama and Tombigbee Rivers. At the distance 
 of from 40 to 8u miles it follows and skirts the At- 
 lantic, forming a mighty barrier to a mighty 
 ocean. 
 
 Granite, gneiss, and micaceous schist, each form 
 a considerable part of this immense ridge. Gra- 
 nite is found on the tops of mountains and on 
 
197 
 
 plains, and is frequently so decomposed as to have 
 lost adhesion for 50 or 100 feet below the surface, 
 exhibiting only sand and gravel. 
 
 Gneiss is more widely distributed and covers 
 nearly half of the primary ridge, including immense 
 beds of granite, some of them 300 feet thick ; ip 
 which beds are found the Emerald, Tourmaline, 
 Garnet, &c. 
 
 Micaceous Schist and Argillite are also widely 
 distributed. 
 
 Primary Mountains may be said generally to 
 be unfavorable to vegitation : their extreme hard- 
 ness, their precipices, and unfriendly soil, doom 
 them to barrenness. Lichens and mosses attached 
 to their sides decay, and furnish soil for larger 
 plants Water penetrates and breaks off masses 
 the influence of air, water, heat and light assist in 
 the progress of disintegration and insensibly, but 
 uniformly and constantly, aid in converting stones 
 into bread or, in other words, in preparing soil 
 from the most sterile rocks for the support of ani- 
 mal and vegitable life. 
 
 The decomposition of granite is slow, and when 
 decomposed the unfriendly siliceous grains are 
 easily washed away. There is neither vegitable nor 
 animal matter in the compound ; it does not absorb 
 
 27 
 
198 
 
 moisture, letting the water percolate ; nor does 
 it retain heat. 
 
 The soil made from gneiss is not washed away 
 quite so easily and the mica yields it more ar- 
 gillaceous earth but it is seldom deep (from 20 
 to 100 feet.) 
 
 Micaceous Schist and Argillite decompose more 
 rapidly, and form a better though not a good soil. 
 
 The rivers of primary districts have rocky 
 beds and precipitous banks. 
 
 Upon the whole, Primary Mountains are covered 
 with a soil less productive than the other classes of 
 rocks and form the barren regions of the Arctic, 
 and the sterile plains of the Torrid. 
 
 'to compensate, in some degree, their water is 
 more pure and clear, and the inhabitants more 
 healthy. 
 
, 
 
 f 
 
 LECTURE VI. 
 
 Transition Rocks Jlrgillite Greywacke Lime* 
 stone Gypsum Porphyry Sienite Greenstone. 
 Secondary Rocks Observations on their Formation 
 Old Red Sandstone Coal Indications of it, &c. 
 Shale Limestone Rock Salt Variegated Sandstone 
 Shell Limestone Lias Oolites Iron SandGreen 
 
 Sand Chalk. Tertiary Formations of France, 
 
 England, and the United States. Alluvia Diluvia 
 Overlying Rocks Conclusion 
 
 Resting on the Primary Rocks already descri- 
 bed, we find others, that have been denominated 
 by Werner, Transition, by others, the Interme- 
 diate, the Medial, the Sub Medial, and by Hutton, 
 the Stratified. They never attain the elevation of 
 the preceding rocks, and are more liable to de- 
 composition. They are considered as not crys- 
 talline. They are the oldest or lowest rocks in 
 which we find any record of vegitable or animal 
 existence, and may be regarded as ancient re- 
 
200 
 
 cords, imprinted with the natural history of the 
 inhabitants of the globe. 
 
 They repose on the primary class, and form a 
 contrast to their bold precipices and rugged peaks, 
 by their less pointed, and more beautiful outline. 
 
 In retaining the term Transition, I do violence 
 to my own opinions. The division of rocks in 
 which that term is adopted is unnecessary and per- 
 plexing. I have elsewhere given reasons for not 
 employing it the following may be mentioned. 
 
 The Rocks called Transition, are often as pure- 
 ly chemical in composition as any other rock. 
 
 Many of them contain no organic remains. 
 
 There is no definite boundary between them as 
 a class and the primary. And lastly it is a division 
 of no practical importance ; and one that is very 
 perplexing to the student. 
 
 In America, they have no line of demarcation, 
 and are often absent altogether. 
 
 If we place these rocks among the primary, as 
 some Geologists do, we shall then have natural 
 limits to every class the red sandstone being 
 placed between the primary arid secondary and 
 the chalk between the secondary and tertiary. 
 
 I shall however retain this name, as I do not 
 consider my own authority sufficient to banish it, 
 
201 
 
 although in so doing, I should but follow the most 
 natural division, and be upheld by some of the 
 best geological enquirers. 
 
 The rocks usually described as transition 
 are but varieties of those we have al- 
 ready mentioned viz. 
 
 Argillite, 
 
 Greywacke, 
 
 Limestone, (metalliferous) 
 
 Gypsum, 
 
 Porphyry, 
 
 Sienite, 
 
 Greenstone. 
 
 ARGILLITE. It is but a few years since this rock 
 has been assigned to different formations ; having 
 until lately been termed Transition. But when en- 
 quirers into nature began to examine for themselves 
 and were no longer led by the great masters of the 
 opposite schools, the structure of the Earth was 
 more thoroughly examined, and new facts discover- 
 ed, which tended to clear up many of the supposed 
 inconsistencies in geological speculations : thus the 
 oscillations and alternations of beds and strata 
 cleared up the supposed irreconcileable positions 
 in which masses were occasionally found, and 
 which no theory accounted for. 
 
 The composition of transition Argillite is the 
 same as that of the primary, viz. Siliceous and 
 
202 
 
 Argillaceous Earths, Magnesia, Lime, and Oxide 
 of Iron. 
 
 It has various shades of grey, varying to pur- 
 ple, red and green. 
 
 It is soft and easily decomposed ; and is fusible. 
 It rests upon gneiss or mica slate. It contains 
 beds of limestone, and alternates with the rocks 
 in its vicinity, frequently having grejwacke 
 interposed. 
 
 It splits into laminae, and is then useful for va- 
 rious purposes : that which is easily divisible into 
 thin plates, and is compact and sonorous, is term- 
 ed roof slate. 
 
 Some varieties of it are used for writing slates. 
 It frequently abounds in iron pyrites, which ren- 
 ders it unfit for use. It also contains alum slate, 
 and flinty slate. 
 
 It is an abundant rock. That termed transition is 
 more plentiful than that before noticed. The ele- 
 vations composed of it are usually tabular and 
 flat. 
 
 I have already mentioned that Argillite is quar- 
 ried in Rensselaer County. 
 
 In the vicinity of Hudson, it is seen forming the 
 banks of the river, and is found on and near the 
 banks of the Hudson as far north as Fort Miller, 
 
203 
 
 :^" - 
 
 It frequently contains metallic treasures. In 
 Guanaxuato. in New Spain, this rock is traversed 
 by a vein that for 17 years produced annually 
 556,000 marks of silver. A mine in this rock in 
 Valencia yielded JbO,000 marks of silver annually 
 for 40 years. 
 
 Argillite sometimes contains porphyry arid sien- 
 ite. In the North of Europe the three alternate. 
 
 When Argillite contains imbedded grains and 
 masses of indurated clay, quartz and flinty slate, it 
 then forms what is termed 
 
 TRANSITION GREYWACKE, denominated fine or 
 coarse according to the size of the grains : when 
 the former variety is slaty, it is then called Grey- 
 wacke Slate, which is in fact coarse argillite,, and by 
 a combination with mica, passes into mica slate. 
 
 It alternates with flinty slate and limestone. In 
 England two formations of Greywacke alternate 
 with two formations of limestone. 
 
 It is closely allied to the preceding rock, argil- 
 lite passing into greywacke slate, which has a 
 homogeneous appearance and a slaty structure. 
 It is distinguished from it only by its grey color, 
 and by the glimmering of the mica it contains. 
 
 In a general sense, Greywacke means, accord- 
 ing to Humboldt, every conglomerate, sandstone, 
 or puddingstone, fragmentary or arenaceous rock 
 
204 
 
 of transition formation, that is anterior to the red 
 sand stone of the coal formation, (old red sand- 
 stone.) In a more limited sense, it is confined to 
 the arenacious transition rocks, which contain only 
 small fragments of simple substances, more or less 
 rounded ; for instance, of quartz, of lydian stone, 
 of felspar, and of clay slate, but not fragments of 
 compound rocks. In the latter case, the term 
 greywacke is inadmissable, and the name of brec- 
 cias or conglomerates, with large primitive fragments, 
 is given to various agglutinations of pieces of gra- 
 nite, gneiss, and sienite. 
 
 Calcareous puddingstones are those in which 
 rounded fragments of carbonate of lime are cemen- 
 ted by a base of the same. 
 
 Coarse greywacke passes easily into conglomer- 
 ates with large fragments, and alternates with 
 those of fine grain and homogenious aspect. The 
 puddingstones and breccias with large fragments 
 of primitive and compound rocks are true grey- 
 wackes. 
 
 Greywacke is metalliferous. It is oi'ten traver- 
 sed by quartz. The novaculite, or hone slate, be- 
 longs to it, as does the rubblestone or rubble- 
 wacke which is connected with the Catskill Moun- 
 tains. 
 
 
205 
 
 Kedwacke is seen in a layer between the vil- 
 lage of Catskill and the mountain, which has now 
 become so fashionable a resort. 
 
 Mr. Eaton says that this rock underlays all the 
 western part of our state. In Rensselaer, Wash- 
 ington, and Columbia Counties, it is often met with 
 covering extensive tracts. 
 
 Alternating with these two last mentioned rocks 
 occurs a Limestone, called TRANSITION LIMESTONE, 
 Metalliferous Limestone, and Carboniferous Limestone. 
 Part of this formation is the Mountain Limestone of 
 some Geologists, who treat it separately. It is 
 compact and has not the crystalline structure of 
 the limestone formerly spoken of Werner called 
 the lower beds of this rock transition limestone, 
 and the upper he termed floetz but this distinc- 
 tion is justly abolished ; and the two are properly 
 spoken of together. Humboldt has divided it in- 
 to granular talcose limestone, and black limestone, 
 but places both under the same head. Their 
 characters coincide and it is only their relative 
 position that induced Humboldt to give them these 
 names in his excellent work on the superposition 
 of rocks. They are both metalliferous, and con- 
 tain traps and amygdaloids. They occur in vast 
 masses, and form mountains with perpendicular 
 
 cliffs and steep ravines. 
 28 
 
206 
 
 The lowest beds usually rest on argiilite, 
 with which they alternate. They contain some 
 carbon, (about 0.75 or | pr. ct.) whence they derive 
 their colors, which vary, usually having a greyish 
 hue, and always darker than the primary. The stra- 
 ta are not well marked, and are of great thickness. 
 Organic remains are rare in this rock the cata- 
 logue is, however, very curious and instructive. 
 The black limestone contains orthoceratites several 
 feet long entrochites, madrepores, pectinites and 
 ammonites. It is extremely difficult to draw the 
 line of boundary between the upper and lower 
 beds. 
 
 Some of the celebrated marbles of antiquity be- 
 long to this deposit as the marmor luculleum 
 the nero antico the African flowered marble 
 the pavonizzo, and, according to Humboldt the 
 gilded breccia. 
 
 I have already mentioned that a difference oi 
 opinion exists in regard to the manner in which 
 we find the series of these rocks contorted. It is 
 from the limestone series that many of the argu- 
 ments are drawn. 
 
 The strata of limestone countries present many 
 interesting phenomena and which, if we allow 
 the action of either of the discordant agents, i? 
 easily accounted for. The arguments of Huttoru 
 
207 
 
 Playfair and Hall are specious, and to him who 
 hears only the arguments of one school, carry 
 conviction. That the undulations of strata have 
 received their several characters in a horizontal 
 position, can readily be imagined and easily ac- 
 quiesced in. But not so with the irregularities, 
 contortions and disruptions. Here the other 
 school interposes, and is strongly aided by argu- 
 ments drawn from nature. It must be admitted, 
 that when Hutton allowed a certain agency to wa- 
 ter, and a certain power to the action of subter- 
 ranean heat, he combined the good of both theo- 
 ries, and appears above the rank of a mere 
 theorist. , 
 
 The upper portions of this deposit contain 
 peculiar fossils many of which appertain to spe- 
 cies now extinct. 
 
 It is a singlar circumstance that a part of our 
 globe should be covered by animal secretion, yet 
 such is the fact, as was shown when speaking of 
 coral reefs. 
 
 In this and the succeeding rocks, organic re- 
 mains, or petrifactions, become so frequent, as by 
 many to be supposed characteristic of the differ- 
 ent beds in which they are found Of the accura- 
 cy of these remains as a geological standard, I hare 
 spoken elsewhere ; but I cannot omit here to 
 
208 
 
 mention the sentiments of Humboldt, who, in treat- 
 ing of these rocks, observes, "Although we are yet 
 far from being able to complete the history of ma- 
 ny intermediate and secondary formations by an 
 enumeration of the fossils found in them, we shall 
 indicate some that characterise this group (in 
 which he includes transition argillite, with grey- 
 wacke, greenstone, black limestone, sienite and 
 porphyry.) 
 
 In argillite and greywacke, monocotytedon 
 plants, perhaps anterior to the most ancient ani- 
 mals, entrochites, coralites, ammonites, hys- 
 teriolites, orthoceratites, pectinites, trilo bites, 
 in which no traces of eyes are disernable ; ogygies 
 of Brongniart, in which the eyes are indicated on- 
 ly by two tuberosities on the scutum (found in 
 our country) calymene of Tristan, and calymene 
 macrophtalme of Brongniart. 
 
 In the most ancient beds of the limestone, entro- 
 chites, madrepores, belemnites, sometimes insula- 
 ted ammonites, orthoceratites, asaphus buchii. 
 asaphus hausmanii, and a very few bivalve shells. 
 In the newer beds of limestone, calymene blumen- 
 bachii, (found on the Miami) asaphus caudatus of 
 Brongniart, ammonites, terebratulites, orthocera- 
 tites, some gryphites,and encrinites." 
 
 

 209 
 
 This formation is to be studied in many places 
 in the western part of our state. At Trenton Falls 
 on West Canada Creek, a place now often visited, 
 it contains many of the beautiful fossils pecu- 
 liar to it. Orthoceratites, nautilites, terebratulae, 
 productae, encrinites, and trUobites among which 
 is the beautiful new genus of Isotelus, lately insti- 
 tuted by Dr. Dekay.* 
 
 Gypsum, porphyry, sienite and greenstone are 
 found among these rocks : Gypsum, however, does 
 not occur in sufficient quantity to be noticed. In- 
 deed it is doubted if in a geological system, it 
 should be mentioned at all, except as an occasion- 
 al rock, as other than secondary, it is so sel- 
 dom found in this place. According to Brochant 
 it is found in connection with transition limestone. 
 
 Porphyry, sienite, greenstone and amygdaloid 
 have already been noticed : they occur here in 
 small quantities as occasional rocks, or rather as 
 alternating with others, and have some characters 
 distinct from their earlier beds being less crys- 
 talline and more compact. 
 
 PORPHYRY, having a base of indurated clay, is 
 usually mentioned as transition porphyry. Its 
 fracture is dull and earthy. It is moderately hard 
 
 *See Annals of Lyceum of Nat. Hist, of N. Y. vol. 1. 
 
210 
 
 and adheres to the tongue. The colors are grey, 
 greenish, brown, &c. with a tinge of red or yellow. 
 
 It sometimes presents a columnar aspect. Oc- 
 casionally it contains nodules with a centre of cal- 
 cedony. It is liable to decomposition, and resem- 
 bles volcanic products. When in the vicinity of 
 coal, it contains vegitable remains. 
 
 Porphyry alternates mostly with argillite, sien- 
 ite, greenstone and black limestone. 
 
 In South America all the porphyry is found in 
 the most western and elevated part of the conti- 
 nent, none being found east of the Andes, through- 
 out the whole eastern part of South America. 
 
 The Cordilleras contain perhaps the greatest 
 mass of porphyry : it is particularly rich in gold 
 and silver ; and associated intimately with rocks 
 produced or changed by fire. The limits between 
 the transition porphyry and volcanic rocks of 
 South America are not easily traced. 
 
 The porphyry of Mexico is rich in silver and 
 gold. The pit of del Encino furnished 50,000 
 marks of silver annually for a long time. In 
 ] 726-7, two workings in South America yielded 
 542,000 marks, almost twice as much as all Eu- 
 rope and Asiatic Russia in the same time. 
 
 Most of the porphyries of South America ex- 
 hibit a tendency to a regular stratafication, which 
 is seldom observed in Europe. 
 
211 
 
 SIENITE and GREENSTONE have already been 
 mentioned, as transition rocks ; they occur in in- 
 timate association with each other, with porphyry 
 and with amygdaloid ; the hornblende of porphyry 
 often becoming more distinct in the sienite, and 
 finally abounding in the compact and sonorous 
 greenstone. When the crystals imbedded in por- 
 phyry are exchanged for oval or diamond shaped 
 substances, the mass is called AMYGDALOID. Indu- 
 rated clay, greenstone, or wacke, may constitute 
 the bed, and the almond shaped nodules may be 
 calcareous spar, quartz, zeolite, hornblende, calce- 
 dony, agate, epidote, felspar, &c. &c. One mine- 
 ral only is usually found in a cell ; but occasion- 
 ally there are two or three surrounding a nucleus. 
 
 At Mount Holyoke, in Massachusetts, it occurs 
 precisely similar to some European localities. It 
 is found near Boston, and frequently in Maryland. 
 
 In the synopsis at the end of this work, these 
 substances will be found mentioned. 
 
 These are the unimportant varieties of the pre- 
 ceding rocks usually classed as Transition, but 
 which in fact should be considered as primary, 
 where Lehman placed them, and whence they 
 should never have been removed. 
 
We often find that novelties in Science are re- 
 prehensible. Few are capable of understanding 
 and appreciating the many and often distant bear- 
 ings that one point has upon many others, and of 
 discriminating between the relations they bear 
 each other. A fancied difference does not always 
 constitute a true distinction. It is this accuracy 
 of discrimination which placed some of the oldest 
 naturalists so far above many of our own day 5 
 and assigns to Linnaeus a place, to which all the 
 research and philosophy of a more enlightened 
 period can elevate very few of the living na- 
 turalists. 
 
 >' " '* 
 
 In accounting for rocks other than the primary, 
 the theories of Geologists coincide, as both Wer- 
 ner and Hutton considered them as original depo- 
 positions from aqueous solution But the situation 
 of the strata as we now find them, has caused 
 much discussion. That they were originally hori- 
 zontal is granted : the question is, how were they 
 placed in the inclined or vertical position ? The 
 disciples of Werner, or the Neptunian school, sup- 
 pose that in the original formation of these rocks, 
 there existed immense caverns, such as we often 
 see at the present day, and that these have fallen 
 in, and thus caused the inclination of beds, &c. ; a 
 
 
213 
 
 supposition rendered in some measure probable 
 by the immense extent of many existing caves 
 by the quantity of water now running through 
 them and by the great power which it is known 
 to exert. In all Limestone countries they exist 
 even now and rain and moisture oozing through 
 crevices may have filled many, more or less, the 
 softer parts of the wall may have been dissolved 
 or worn away and the roof and super-imposed 
 strata have fallen in. 
 
 It is urged against this theory, that instead of 
 the strata having fallen in, the primary rocks have 
 been forced up into the superincumbent mass. 
 
 The disciples of Hutton,or the volcanic school, 
 conjecture that after these strata were hardened, 
 they were elevated with the primary rocks, then 
 in a state of igneous fusion, by some force below. 
 The recent discoveries of Sir Humphry Davy have 
 been supposed to throw light on the expansive 
 power of heat, and to furnish strong evidence in 
 favor of this theory, which is said thus to stand the 
 test of experiment, and to be more clearly explain- 
 ed by the progress of knowledge. On the other 
 hand, it is asked what is that influence exerted by 
 Alpine chains on beds at the distance of of 400 
 miles ? Is it a fact that there existed at the same 
 
 great depth a force which heaved up mountains 
 29 
 
214 
 
 and bent the strata of the plains, so that the bent 
 edge of those strata, formerly horizontal, are now 
 all inclined at nearly the same angle ? Were the 
 Alpine chains heaved up ? If so, it is singular that 
 they issued from fissures all parallel to the direc- 
 tion of the pre-existing inclined beds. 
 
 The secondary rocks repose universally on 
 those we have already described. They are less 
 elevated, and their angles with the horizon less 
 than the preceding. They have an unconforma- 
 ble position to the primary, usual!) , though not 
 necessarily. It may, however^ be laid down as a 
 rule, that all rocks succeeding to any one rock 
 that is unconformable in position to the prima- 
 ry, belong to the secondary. Red sandstone is 
 the lowest that has universally this position, and 
 may therefore be justly mentioned as the oldest 
 secondary rock, and all above it belong to the 
 same class. They rest on the sides of primary 
 ridges or at their feet, and compose the interven- 
 ing vallies. Their texture is more or less earthy, 
 very rarely crystalline. They are often mechanical 
 mixtures composed of parts of the primary rocks, 
 united by cement. Their horizontal position and 
 the presence of large numbers of animal and vegit- 
 able remains are also characteristics. They are 
 
215 
 
 usually unstratafied. None of these characters 
 are so invariably marked as the geological posi- 
 tion ; the associations of a rock being among its 
 most valuable and steady characters. 
 
 The number of secondary rocks is much more 
 limited than the primary, being confined mostly 
 to sandstone, limestone and shale but present a 
 great variety in detail, even independent of their 
 organic contents. 
 
 The extent and depth of secondary rocks are 
 also more limited than the primary. If they were 
 not often absent, the primary would never be seen 
 on the surface. The primary, in fact, constitute 
 the great mass of the globe while the secondary 
 are partial, as a covering to them. The primary 
 may be considered universal, since they bear the 
 same characters in every part of the world ; and 
 could we have access to them, they would most 
 probably be found in a similar and uniform posi- 
 tion every where. The secondary can only be 
 considered universal, inasmuch as similar rocks 
 occur, as far as their chiet characteristics are con- 
 cerned, in every part of the globe. But they are 
 not continuous, and therefore only partial even 
 perhaps partial in a more limited sense, as some 
 varieties are peculiar to certain countries, and not 
 found at all in others. Their laws are not so gen- 
 
216 
 
 eral, operating only on a limited or local scale, 
 while the laws of the primary seem to have ex- 
 tended over the whole globe. 
 
 The occasional absence of these secondary is 
 owing to two causes. The action of the elements, 
 which in the lapse of ages, mu*t have destroyed 
 them partially ; and the original deposition seems 
 to have been often local, and confined to concavi- 
 ties, technically termed basins. 
 
 The chief members of the Secondary Class may 
 *be reduced to four, viz. 
 
 1. Red Sandstone, or Great Coal Deposit. 
 
 2. Alpine Limestone or Magnesian Limestone : 
 with Rock Salt. 
 
 3. Arenacious and Calcareous Deposits ; which 
 embrace the variegated sandstone, or new red 
 sandstone, gypsum and rock salt, shell limestone, 
 sandstone, lias, marie, oolite, ferruginous sand and 
 green sand. 
 
 4. Chalk. 
 
 RED SANDSTONE is one of the most important 
 rocks of this class. It is also called old red sand- 
 stone to distinguish it from a newer variety called 
 also red marie or variegated sandstone. 
 
217 
 
 it is formed of the fragments of the preceding 
 rocks or minerals varying from coarse to fine, 
 according to the size of the grains. 
 
 It rests always on the preceding rocks ; varying 
 in appearance as it is more or less mixed with ad- 
 ventitious minerals. The simple minerals enter- 
 ing into its composition are quartz, frlspar, clay, 
 mica, arid carbonate of lime. The rocks, which 
 by their fragments, contribute to the formation of 
 this one, are all of the primary class. 
 
 It contains few imbedded minerals, which re- 
 mark is applicable to all the secondary rocks 
 Sulphat of strontian and calcareous spar are the 
 most common. 
 
 It contains very few organic remains. 
 
 Its color is red as the name denotes varying 
 from a bright ochre to the darkest brown, or even 
 blackish purple. 
 
 This rock is so immediately connected with 
 coal, as to be treated of with it in all works on 
 geology. 
 
 Where beds of old red sandstone are associated 
 with calcareous beds, good soil is generally pro- 
 duced. 
 
 The summits of mountains composed of this 
 rock are mostly covered with mosses. 
 
COAL is so intimately associated with this rock, 
 that I cannot persuade myself to pass it unnoticed. 
 Indeed its value and importance to our city ranks 
 it among the most useful of all formations, and one 
 of the most interesting of all mineral strata. I 
 may perhaps be allowed to dwell upon it, as it is 
 a subject of primary interest to our City and 
 State. 
 
 The oldest variety of coal that exists is the 
 slight trace of carbon that we find occasionally in 
 primary rocks ; but never in sufficient quantity to 
 work. 
 
 We are not to look for coal in any of the rocks 
 that we described at our last lecture; nor in those 
 that I have just mentioned. It is never found in 
 rocks older than the red sandstone, in connection 
 with which it is most generally found, occasionally 
 alternating with other rock or earthy strata. It 
 forms one of the most important branches of geo- 
 logical science. 
 
 The lateral extent of coal deposits, often called 
 1 fields, is sometimes very considerable. 
 In many places they occupy basin shaped cavities, 
 having all the edges turned up, and perhaps crop- 
 ping out : In other places they are inclined at such 
 angles that their extent cannot be known, or con- 
 jectured. It is usual for more than one bed to be 
 
219 
 
 ibund in a deposit ; and sometimes ten or twenty 
 are found. At Liege there are sixty beds alter- 
 nating with sandstone, limestone, shale, clay 
 and sand. The thickness of a bed varies from an 
 inch to many feet or yards. The strata are gene- 
 rally divided by natural joints, more or less perfect 
 and extensive, by which they are formed into 
 cuboidal or prismatic masses. They are usually 
 laminar. 
 
 The mineral composition of coal does not strict- 
 ly come within my province, yet as it is not gen- 
 erally understood, it may be noticed in the brief- 
 est possible manner. 
 
 All the Bitumens from Naptha to Asphaltum, 
 consist of compounds, apparently indefinite, of car- 
 bon and hydrogen principally : the small quanti- 
 ties of oxygen and azote which they contain, ap- 
 pearing to have little or no effect in modifying the 
 mineral characters. In the most fluid, the hydro- 
 gen predominates, diminishing progressively ac- 
 cording to the order of their relative tenacity or so- 
 lidity. Where asphaltum ends this series, cannel 
 coal, with some interruption in composition, and a 
 considerable one in texture, commences that of 
 coals. From this variety down to the most perfect 
 anthracite, there is a similarly indefinite range of 
 composition: the hydrogen generally diminishing as 
 
 
220 
 
 the coal becomes less inflammable, as it is less ca- 
 pable of being separated into bitumen and char- 
 coal by distillation, and as it yields a smaller com- 
 parative proportion cf the former. Thus the com- 
 position of the bitumens illustrates that of the se- 
 veral varieties of coal. The most perfect anthra- 
 cite appears to yield no bitumen, yet it contains 
 hydrogen perhaps in every case; as that element 
 is present even in common charcoal, which is it- 
 self a compound substance. Where anthracite 
 passes to plumbago, which may in fact be con- 
 sidered as the true end of this series, the hydro- 
 gen seems to have disappeared ; and if this sub- 
 stance be not mere carbon, as it probably is not, 
 from the apparent combustion which it undergoes, 
 on exposure to air, when its base has been extri- 
 cated from iron under water, it undoubtedly ap- 
 proaches nearer to that element than any of the 
 preceding substances. 
 
 We all know that there are several varieties of 
 coal, and that it is of the utmost importance to us 
 as housekeepers as well as proprietors of land to 
 know their distinctive characters and names. 
 
 Anthracite, or native mineral carbon, or blind 
 coal is the first we shall notice. It is not, strictly 
 speaking, a coal, though combustible. Its color is 
 black or brownish, but seldom the black of true 
 
221 
 
 coal. It presents the most beautiful irised or tar- 
 nished colors. It is harder than common coal, but 
 breaks easily. It soils the fingers has an unctuous 
 feel aud is somewhat slaty. It burns slowly, and 
 with difficulty yielding little or no flame, nor 
 smoke, nor bituminous odour. After burning it 
 leaves about 23 pr. ct. of grey ashes. It yields no 
 bitumen, and the very feehle flame, which it occa- 
 sionally exhibits, appears to arise from the hydro- 
 gen of the water it contains. 
 
 Anthracite, like the Diamond, appears to be es- 
 sentially composed of pure carbon, but in a very 
 different state of aggregation. That from Kilken- 
 ny yields 97 parts in 100 of carbon that from 
 Rhode Island 95. 
 
 When once ignited, Anthracite yields an in- 
 tense and lasting heat and much ot the difficulty 
 of kindling it may be avoided by the addition of 
 a certain quantity of charcoal, and by the proper 
 application of a strong current of air. 
 
 Being composed mostly of pure carbon, without 
 any bitumen or sulphur, except occasionally from 
 pyrites, it burns without caking, and is very useful 
 on all occasions where strong and uniform heat is 
 requisite. In all manufactories, and for the forge, 
 it is inestimable. 
 
 30 
 
222 
 
 In speaking of the primary rocks, in our last 
 Lecture, I mentioned that they contain no coal; i. e. 
 we know of no coal mine in such rocks as gra- 
 nite, gneiss, &c. But this Anthracite, which I 
 have stated is not a true coal, is found in the pri- 
 mary rocks. And hence it is obvious that this 
 combustible has not proceeded from the decom- 
 position of vegetable substances, since it is gener- 
 ally acknowledged that the primary rocks were 
 formed previous to the existence of vegetation. 
 
 We have abundance of this combustible in the 
 United States. 
 
 Rhode Island coal is this very substance. It is 
 there found near the surface covered by shale and 
 sandstone. It contains 94 pr. ct. of pure carbon. 
 In Massachusetts also it is found, and in some of 
 our new states. In Arkansas it is of good quality 
 and in abundance. 
 
 The most extensive locality, and of the greatest 
 interest to our city, is in Pennsylvania, on the north 
 east branch of the Susquehannah, and near the 
 heads of the Laxawanna, Fishing, Muncey, Le- 
 high and Schuylkill rivers. It extends down the 
 Susquehannah to within 10 miles of Sunbury, and 
 down the Schuyikill to within 20 miles of Reading, 
 and is lost under Peters' Mountain. From the 
 north east branch of the Susquehannah, it ex- 
 
tends about 30 miles east, but only 2 or 3 west. 
 At Wilkesbarre, it runs under the river. It ap- 
 pears also at the surface of the country in beds of 
 from 20 to 30 feet thick. This extensive forma- 
 tion is worked at several places and the Lehigh, 
 the SchuyUill, the Wilkesbarre, and the Laxa- 
 wanna (or Laxawaxen as it is called) are from dif- 
 ferent parts of the same bed, and derive their 
 names irom the places near to which it is 
 worked. At Wilkesbarre, it is quarried at the 
 surface by means of gunpowder and wedges. 
 
 The Lehigh coal, which is quarried a few miles 
 from the river, has been deservedly brought into 
 use and is supposed to be worth double the 
 value of Virginia coal. 
 
 The Schuylkill is in all essentials the same. 
 
 The Laxawanna is from the north east portion 
 of the same bed and has rather a larger propor- 
 portion of bitumen so that it affords rather more 
 flame, and cakes more than the others. 
 
 We will all have an opportunity soon of forming 
 correct estimates of their comparative value. 
 
 Besides Anthracite, there is another mineral 
 often spoken of as coal, which is in fact a different 
 substance. I mean Lignite, of which there arc 
 several species, all derived from wood that has 
 
been buried below the surface, and decomposed. 
 Jet, of which ornaments are made, is one species. 
 The Bovey coal of England, is oi this kind It 
 does not occur in such quantities as to be quarried 
 for fuel. 
 
 At Cape Sable (Maryland) it occurs in beds of 
 5 or 12 feet thick. At Martha's Vineyard it oc- 
 curs in small quantities. 
 
 True coal is always black, and shining, com- 
 pact, and with an even fracture. It is too hard to 
 be scratched by the finger nail. 
 
 True coal burns easily, with a whitish flame, 
 yielding a black smoke, and a slight, but not un- 
 pleasant smell of bitumen. It never leaves less 
 than 3 pr. ct. of residuum, sometimes much more. 
 
 It is essentially composed of charcoal and bitu- 
 men, in different proportions, the carbon chiefly 
 predominating, and sometimes composing 3-4 of 
 the whole. 
 
 It is easily distinguished from Anthracite, which 
 burns with difficulty,. does not give a white flame, 
 nor the black smoke, nor the bituminous odor of 
 coal. 
 
 The different coals pass into each other, but 
 seldom or very rarely pass into anthracite. 
 
 The cannel, candle, or parrot coal, the slaty 
 oal, the coarse coal, and the sooty coal are 
 only varieties. 
 
225 
 
 Coal is usually found in beds, at greater or less 
 elevation. At New Castle, where there are 27 
 beds, it is upon a level with and below the sea. 
 At Whiteh^ven it is 400 yards below the sur- 
 face, and the working extends 1700 yards beneath 
 the sea. 
 
 In our country coal is found at no great elevation : 
 but in South America, at the table land of Santa Fe 
 de Bogota, it rises 1 360 toises, or 1 3.500 feet above 
 the level of the sea, and at Huanuco, it is 2300 
 toises above the sea, and near the limits of per- 
 petual snow. 
 
 The Origin of coal is by most geologists attri- 
 buted to the decomposition of vegetable matters 
 in the interior of our earth. The remains of ve- 
 getables that accompany coal, and the carbon and 
 hydrogen of its composition, render this idea very 
 probable. It has been objected . that we sometimes 
 find in beds of coal, vegetables that are scarcely 
 decomposed. 
 
 It is generally allowed that coal has been pro- 
 duced after the creation of organised bodies; and 
 that previous to its consolidation it has been at 
 least partially fluid, either by solution in water, or 
 by the action of heat under comprebsion : which 
 accounts ibr its crystalline structure, and often for 
 te contained minerals. 
 
 
226 
 
 There is a remarkable uniformity in the position 
 of coal and its accompanying minerals, in all parts 
 of the world. It is usually found under a thin 
 layer of shale, which is called the roof. The 
 stratum beneath the coal is called its floor. 
 
 Whatever cause produced coal, it has been ma- 
 ny times repeated hence the great number of 
 beds of coal in the same mine, under the same 
 circumstances. 
 
 From whatever fluid coal was deposited, that 
 fluid was in a state of rest at the time of the de- 
 position, since the leaves of fern, &c. which are 
 found, are always in an expanded state. Jameson 
 notices a trunk of a tree 40 feet long, rising through 
 a coal formation. At New Castle, one was obser- 
 ved 30 feet long, of which the trunk and large 
 branches were petrified, or become siliceous, 
 while the small branches, the bark, and the 
 leaves, had been converted into coal. 
 
 In the coal mine of Treuil. near St. Etienne, in 
 France, 4k are found a great number of trunks, pla- 
 ced in a vertical position, traversing all the layers 
 of a bed. It is a real forest of monocotyledonous 
 vegetables, in appearance rest mbling bamboos or 
 the large equisetum. petrified on the spot." 
 
 Similar facts have been observed in the coal 
 fields of Scotland, in the mines of Maneback, and 
 in Saxony. 
 
227 
 
 We have large quantities of coal in this country. 
 Illinois, Missouri, Indianna, Kentucky, and Ten- 
 nessee have it in abundance. In Ohio there are 
 all varieties of true coal. That of Virginia ex- 
 ists in great quantity. 3ut here we again turn to 
 Pennsylvania, one third of which state rests on 
 coal. The west side of the Susquehannah river, 
 from near the mouth of the Juniata, through all 
 the country watered by the west branch of the 
 Susquehannah and its streams, to Pittsburg, and 
 thence down the Ohio and its streams, contains 
 coal of a good quality. At Pittsburgh it approach- 
 es the surface. 
 
 It is to be observed that the situation I have 
 here given to our true coal, is different from that 
 assigned to the Anthracite of Lehigh and the 
 Schuylkill. 
 
 As this subject has become of great interest, 
 and as much time and money have been expended 
 in fruitless searches for this valuable article, mere- 
 ly from the want of a few simple facts, it may not 
 be improper to notice a few circumstances which 
 we should always have in mind, when coal is the 
 object of our researches. 
 
 It may be laid down as an invariable rule, that 
 good coal in sufficient quantity to work, is never 
 
iound in primary rocks as granite, gneiss, &c. 
 so that the idea of coal being found in the High- 
 lands of the Hudson, is without foundation. It is 
 possible that anthracite may be found, but no 
 coal. * 
 
 Neither are we to look for coal on Long Island, 
 nor in the low lands of New-Jersey. The Lignite 
 or Bovey coal may exist there, and be valuable : 
 but it is very doubtful if the quantity would be of 
 consequence. 
 
 From the position in which I have stated coal to 
 be found, it is evident that at least one edge of every 
 seam of coal must rise, in some place, to the surface: 
 and we must examine all thoseplaces where strata 
 have a chance of being exposed, as rivers, gullies, 
 small streams, and ditches; from some of which 
 we will soon learn the possibility of finding the 
 object of our search. White and red sandstone 
 are not always in company with coal but shale, 
 containing small balls of iron stone, and small 
 thin strata, in the composition of which, arid be- 
 tween the layers of which there is the slightest 
 tinge of coal, are never found except near coal 
 fields. 
 
 * While correcting this proof, we have seen in possession of 
 Dr. Dekay, specimens of anthracite, said to be found in this 
 locality. 
 
229 
 
 Though the seam of coal comes to the surface, 
 still it is liable to decomposition, and on that ac- 
 count may be found covered by and mixed with 
 clay, gravel, or sand, in which case, the mass above 
 is usually found to contain small pieces of coal. 
 If these are found in a ravine, we may be sure the 
 seam of coal is higher up than the spot where they 
 occur. Sometimes too, the superficies of a coal 
 seam becomes in part dissolved, and presents a 
 black friable bed on the surface ; and should this 
 occur on a side hill, it often gradually descends 
 so as to cover a large space, becoming thinner 
 as it descends. This black bed is often found 40 
 or 6() yards from the real coal and has often so 
 deceived the inexperienced as to occasion im- 
 mense sums to be thrown away within a few yards 
 of the coal, especially where the declivity is rapid, 
 as then it is not so easily traced. 
 
 It is necessary too to notice the strata of rock, 
 and mark what angle they make with the horizon; 
 and to what point of the compass they run. 
 Sometimes the coal runs parallel to a gully or ra- 
 vine for a long distance and other times crosses 
 it. In the last position it is more readily noticed. 
 In the former, much trouble and cost is occasion- 
 ally the consequence. 
 
 31 
 
230 
 
 Even when the appearance of coal is found, and 
 is. favorable, it requires knowledge and judgment 
 so to dig as to hit the bed. No accurate idea can 
 be formed until the bed is so laid open to view, as 
 to show itself between the roof and floor or pave- 
 ment. We may then judge of its thickness, as 
 that rarely alters we may also judge of the puri- 
 ty of the coal, as it sometimes contains stones or 
 pyrites also if it be hard or soft, or if it will burn 
 well or not. Many beds of coal improve as they 
 descend, and it is generally admitted, that all 
 coal is better, that is found under a greater mass 
 of superincumbent strata. 
 
 SHALE, or slate clay, or secondary argillite, re- 
 sembles the argillite already noticed, from which 
 it differs only by its less solid and indurated state. 
 It is formed by the decomposition of older rocks, 
 and is fine or coarse, according to the size of the 
 materials, sometimes even containing fragments or 
 large nodules of rocks. 
 
 The texture is shistose, divided by natural 
 joints into beds. 
 
 It seldom forms extensive tracts of country, be- 
 ing usually subordinate to more important and 
 conspicuous formations. 
 
g, 
 
 231 
 
 ' * ^ 
 
 it occurs most frequently in very thin strata or 
 laminae, alternating with other rocks. It is as- 
 sociated with coal, alternating with it, and often 
 impregnated with bitumen. It is found also with 
 secondary limestone, forming thin strata, alterna- 
 ting with calcareous beds, or entering as a con- 
 stituent. 
 
 Its resemblance to greywacke is sometimes so 
 strong as to deceive, without an examination of the 
 geological position. 
 
 It often contains many vegetable impressions. 
 
 The next rock we have to mention, is limestone ; 
 called MAGNESIAN LIMESTONE, or Alpine limestone. 
 It is a dull rock, of various colours, usually greyish, 
 from white to black, which it derives from bitumen. 
 Its texture is usually earthy rarely crystalline. 
 This rock is not found in all countries on the 
 continent of Europe it exists in great abundance, 
 and takes the place of the rock I shall next men- 
 tion. On that continent it is the usual repository 
 of gypsum and rock salt two very important 
 minerals. The term Alpine Limestone applied to 
 this rock, is unfortunate, since it offers the idea 
 that the Alps are formed of it: which is erro- 
 neous. 
 
232 
 
 The rock salt found in this rock is also always 
 associated with a certain clay, called IVluriatife- 
 rous clay, which characterises the formation of 
 rock salt, in both hemispheres, as the clay with 
 impressions of fern, does that of coal. 
 
 Rock salt is found minutely disseminated in this 
 clay, or forming large masses and this points out 
 how it is to be worked whether it is to be work- 
 ed or quarried or whether the rock is to be 
 washed by the repeated introduction of fresh wa- 
 ter, for the purpose of dissolving the salt, and 
 thus bringing it out in solution. When the salt 
 does not form true beds, it is often found interwo- 
 ven, as a net work, running through the clay At 
 other times it exists in thin veins. On the eastern 
 declivity of the Andes in a Peruvian province, 
 the river Gualaga has cut its way through the skirt 
 of a mountain of rock salt, which also contains an 
 ore of lead. Indeed, lead, clay gypsum, and 
 limestone, are the usual accompaniments of rock 
 salt. 
 
 In Europe and in South America, rock salt is in- 
 many places quarried, and is open to day. 
 
 Upon comparing the different localities of rock 
 salt in England, at Bex, (Switzerland) on the Car- 
 pathian Mountains, of Hallein. of Hallstadt,of Savoy a 
 and of Halle in Tyrol, it has been noticed that the 
 
;- 
 
 233 
 
 deposits of rock salt in Europe, diminish in riches 
 with their elevation above the sea. In South 
 America, where alone on our continent, we have 
 yet found rock salt, it occurs in immense beds, 
 nearly 1 4,000 feet above the ocean : and only one 
 mine, that of Huaura, in Peru, is richer. It is 
 there worked in the same way as a quarry of 
 marble. 
 
 This limestone has its peculiar fossils, viz. gry- 
 phites, entrochites, terebratulites, pentacrinites, 
 arcse, encririites, ammonites, orthoceratites, bones 
 of the monitor, impressions of lycopodiaceae, and 
 bambousaceae and leaves of dicotyledon plants, 
 analogous to the willow. 
 
 In countries where this rock does not exist, as 
 in England, its place is occupied by another 
 viz. 
 
 The VARIEGATED SANDSTONE, or NEW RED 
 MARLE, which in that, and some other countries, is 
 considered as the peculiar repository of rock salt. 
 In most countries, the salt seems to have been de- 
 posited in basin shaped cavities, similar to those 
 in which we often find coal. This is the case with 
 the salt of Cheshire in England, where one bed of 
 hard salt is 26 yards thick. At C ordova, in Spain, 
 where one mass of salt is nearly 700 feet high, 
 
234 
 
 an3 more than 1200 feet broad, it is encompassed 
 by this rock. 
 
 The sandy deserts of Caramania in Asia afford 
 rock salt so hard and dry that it is used as build- 
 ing stone. 
 
 Where rock salt is not found, and springs sup- 
 ply its place, it is singular that they are always 
 found in a line, or band, as it were : and usually 
 at or near the base of some mountain chain. 
 
 The most splendid and remarkable deposits of 
 salt, are at the foot of the Carpathian mountains 
 the English mines are near its central chain, and we 
 may draw a line on the west of our Alleganies, be- 
 yond which all our salt springs are found. Our own 
 invaluable springs in Onondago, Cayuga, Wayne, 
 and the neighbouring counties are sources of 
 wealth to our state, which are indeed inestimable. 
 In 1 800, when the brine of Onondago was sup- 
 posed to be rich, it afforded but 42,754 bushels 
 In 1814, nearly 300,000 bushels were manufactur- 
 ed allowing the state a revenue of $7,000 and 
 in 182.3, upwards of 6<0,000 bushels were made, 
 and the state reaped a revenue of nearly $76,000. 
 In 1824, the tax amounted to nearly one 
 million of dollars. From the town of Salina, above 
 three millions of bushels might be made, should 
 
235 
 
 the demand require it, and the state would derive 
 an income of $375,000 from the brines of one 
 village. 
 
 The importance of this article is yet to be dis- 
 covered by our citizens. The manufacturer and 
 the agriculturalist are yef to be convinced of the 
 benefits it can afford them : to the agriculturalist, 
 in particular, it offers the means of improving his 
 lands, of increasing his stock, and materially en- 
 larging his profits. 
 
 The various uses of salt, its localities, the plar- 
 ces where it may be found, and the purposes to 
 which it may be applied, have been some months 
 before the public in an " Essay on Salt," to which 
 I may refer you. 
 
 Reposing on the Magnesian Limestone or Varie- 
 gated Sandstone are various beds of lime, under the 
 names of oolite, shell limestone, lias, and marie : 
 and several beds of sand, under the names of fer- 
 ruginous sand, and green sand. 
 
 
 
 The SECONDARY LIMESTONE occupies an impor- 
 portant place in our country and covers the im- 
 mense secondary region embracing the western 
 parts of our state, extending north into Canada, to 
 the primary ridge of mountains dividing the waters 
 
236 
 
 of the St. Lawrence from those of Hudson's Bay ; 
 and south to the Ohio. 
 
 SHELL LIMESTONE (the Muscheikalk of the Ger- 
 man school) is usually the lowest of this class of 
 limestone, and is very similar to the English Port- 
 land stone. 
 
 It is characterised by the great abundance of 
 broken shells pervading the mass. Humboldt 
 supposes that it has an oolite for a geognostic equi- 
 valent. He mentions the following shells as be- 
 longing to it belemnites, chamites, ammonites, 
 nautilites, buccinites, trochites, turbinites, pecti- 
 nites, ostrocites, terebratulites, gryphites, mytu- 
 lites, pectacrinites, ericrinites, &,c. 
 
 What has been usually termed the Jura Lime- 
 stone, is a succession of beds of lias, marl and 
 oolite, of which the former is the lowest. This 
 unfortunate name was given to it by Humboldt. 
 It is also called the Cavern Limestone. 
 
 In England this suite of formations is considered 
 as very interesting, and occcupies the whole space 
 between the variegated sandstone, or new red 
 marie, and the chalk. It is there found to contain 
 several sub-divisions or beds, each bearing a 
 different name. 
 
237 
 
 LIAS reposes, in many places, on the new red 
 inarle; it is a blueish argillaceous mass, alterna- 
 ting with beds of limestone. These beds become 
 thicker towards the lower part, white, arid fit for 
 lythographic purposes. The fossils of the lias 
 are numerous and beautiful. The following list 
 approaches to a perfect catalogue so far as we 
 know, viz. Ichthyosaurus, plesiosaurus, testudo, 
 several species offish, ammonites, (about 20 spe- 
 cies) those having the siphuncle in an elevated 
 ridge, between two furrows are characteristic of 
 this formation. 
 
 Nautilus, scaphites, belemnites, helicina, tro- 
 chus, tornatilla, melania, dentalium. patella, mo- 
 diola, unio, cardita, astarte, area, cucullaea, nucu- 
 la, terebratula, spirifer or pentamenus, gryphoea, 
 ostrea, pecten, plagiostoma, lima, plicatula, hyp- 
 popodium, perna ? echinus, cririoidea : the 
 following species of this genus, pentacrinite, 
 caput medusae, briareus, subangularis, basalti- 
 formis, tuberculatus : many remains of wood, 
 fern, &c. and a species of turbinolia. 
 
 The most characteristic shells of this formation 
 are the ammonites, (bucklandi) the gryphcea, (in- 
 curvata) and the plagiostama, (gigantea.) 
 
 32 
 
238 
 
 The OOLITES or Roe Stones derive their name 
 from the small particles embedded in the mass, 
 giving it an appearance similar to the roe of fishes. 
 The principal building stone of England is from 
 oolitic series. 
 
 Oolite has lately been found in our country 
 Mr. Schoolcraft noticed it regularly stratafied, in 
 the State of Illinois, as containing lead mines, in 
 connection with shell limestone. A locality of 
 it has been noticed in Saratoga county during the 
 last summer. As yet no geologist has thoroughly 
 examined this rock in situ in United States. 
 
 The great mass of oolites in England has been 
 sub-divided, into three distinct systems, each of 
 which has been separately studied and found to be 
 rich in organic remains. They are separated 
 by beds of clay. 
 
 The Lower System or Division of Oolites, consists 
 of oolite -mixed with sand, and fullers' earth, and 
 embraces the great oolite, oolite of Stonesfield, 
 cornbrash, forest marble, and Kelloway rock, of the 
 English Geologists, and the shelly, and arenaceous 
 limestones. The following are the contained fossils ; 
 Saurian animals, two or three species of testudo, 
 several offish, two or three of insects, Crustacea, 
 ammonites, nautilites, belemnites, trochus, voluta, 
 turbo, turritella, rostellaria, ampullaria. natica. 
 
239 
 
 aacella, planorbis, melania, helicina, serpula, 
 modiola, unio, trigonia, cardium, cardita, mya, ve~ 
 nus, lutralia, astarte, fistulana, mytilus, donax, tel- 
 lina, pinna, osirea, pecten, avicula, lima, terebra- 
 tula, chama, plagiostoma, gryphoea, perna, crena- 
 tula ; echinus, encrinites, coralloids and alcyonia ; 
 also fossil wood and vegetable impressions. 
 
 The Middle System or Division of Ooolite^ embraces 
 Oxford clay, (clunch clay) sand, calcareous con- 
 glomerates, (calcareous grit) coral rag, or lime- 
 stones with madrepores and echinites and con- 
 tains the following fossils, viz. bones of the ich- 
 thyosaurus, ammonites, nautilus, belemnites, me- 
 lania, turbo, helix, trochus, rostellaria, patella, 
 serpula, ostrea, pecten, cardita, chama, gry- 
 phcea, trigonia, lima, lithophaga, mytilus, modiola, 
 avicula, plagiostoma, terebratula, echinus, cly- 
 peus, caryophillia, astrea, and fossil wood. 
 
 The Upper Division of Ooolites contains the clay 
 of Kimmeridge, blue and a little bituminous, the 
 Portland stone, Purbeck stone, argillaceous lime- 
 stone with shells, alternating with marl and gyp- 
 sum. 
 
 The list of fossils follows Ichthyosaurus, plesi- 
 osaurus, cetacea ; several species of fish, ammo- 
 
240 
 
 nites, nautilus, belemnite, turritella, natica, so- 
 larium, trochus, turbo, melania, ostrea, astarte* 
 crenatula, pecten, trigonia, venus, modiola, lu- 
 tralia, cardita, cardium, mactra, tellina, chama, 
 nerita, uriio, avicula, cyclas, terebratula, serpula, 
 The ammonite triplicai us, and pecten lamellosus 
 are most characteristic of the Portland oolite ; and 
 the ostrea deltoidea of the Kiinmeridge clay. 
 
 The beds above the oolite are iron sand, green 
 sand, and chalk marie, running into chalk, the last 
 of the secondary rocks, approaching upwards. 
 
 The IRON SAND FORMATION, is composed of a se- 
 ries of strata of sand, and sandstone, occasionally 
 alternating with small beds of clay> loam, marie, 
 fullers' earth, and ochre. The sand and sandstone 
 are siliceous, and coloured by oxide of iron a 
 metal existing in such quantity in this formation as 
 often to render it worth working. This seems to 
 spread extensively over the western parts of the 
 state of New-York, and to be noticed by Mr. Ea- 
 ton,(in the survey of the district adjoining the Erie 
 Canal, which Gen. Van Rensselaer employed him 
 to take,) as the ferriferous sand rock. In England 
 it is occasionally 1000 feet thick, and worked in 
 many places for iron, the most abundant mineral 
 of this rock. 
 

 241 
 
 The organic remains are not numerous : a nau- 
 tilus, fragments of ammonites, belemnites, ostreae, 
 terebratuhe, spines of the echinus, spongitae, and 
 corallines. 
 
 GREEN SAND is composed of Siliceous sand, 
 loose, and united in form of sandstone, by a cal- 
 careous cement, and containing small particles of 
 green earth,whence is derived the name. The size 
 of the grains varies from very small, forming a fine 
 grained sancjstone,to large, forming a conglomerate 
 rock. It is usually divided from the iron sand by 
 a dark blueish clay, containing small specks of 
 mica, with nodules of selenite and iron pyrites. 
 
 The fossil contents are beautiful. A few teeth 
 of fishes have been found, and upwards of 150 
 species of testacea the following may be ennu- 
 merated : ammonites, nautilites, hamites, turrilites, 
 
 ,"*"-! r . IT "' ? -. 
 
 belemnites, varieties of helix, trochus, solarium, 
 turritella, murex, natica, pleurotoma, rostellaria, 
 auricula, am pull aria, planorbis, turbo, vivipara, 
 serpula, dentalium, verrnicularia, patella, arca,cu- 
 cullaea, nucula, trigonia, pecten pectunculus, te- 
 rebratula, cardium, venus, cardita, dianchora, 
 corbula, chama, ostrea, inoceramus, mya, modiola, 
 perna. The echinus in several varieties, resem- 
 bling,but different from, those found in the chalk. 
 
242 
 
 The encrinital remains are lew, the coralloids 
 scarce and unimportant. The remains of Alcyo- 
 nites are numerous and beautiful. No vegetable 
 remains, but fragme nts of silicified wood. 
 
 Many of these interesting fossils have been 
 found in some of our southern states. The re- 
 gion in the vicinity of the Potomac has afforded 
 many beautiful specimens for the cabinets of our 
 different societies and of individuals. 
 
 By alternations of sand with argillaceous and 
 cretaceous beds, until the latter prevails.the green- 
 sand passes gradually into a chalky marie. It 
 differs from chalk by its grey or mottled appear- 
 ance, and its lamellated texture. It is more gritty 
 than chalk, and will not mark. The upper and 
 more cretaceous beds, next to the chalk, contain 
 fossil remains, similar to those found in that rock, 
 viz. nautilus, inoceramus, echinus, alcyonia, and 
 spongia. The lower beds, which are also more 
 argillaceous, have their peculiar fossils ; those pe- 
 culiar to, and characteristic of this formation, are 
 the ammonites, mantelli, mi nut us, planicosta, ro- 
 stratus, splendens, variens : the nautilus, insequalis 
 elegans, comptoni. Hamites. The other remains 
 are scaphites, turrilites, belemnites, dentalium, 
 vermicularia, cerithium, euomphalus, patella* 
 

 243 
 
 terebratula, area, nucula, pecten, inoceramus,echi- 
 nus, zoophytes, pentacrinite. 
 
 ' 
 
 The rock next in order is CHALK, into which the 
 marie last mentioned easily passes, by almost im- 
 perceptible gradations, forming at first the chlori- 
 ted chalk, (glauconie crayeuse, of the French) 
 having small grains of chlorite sparingly intermix- 
 ed ; then the coarse chalk, (cr^ie tufauj greyish 
 and sandy, containing some marl and hornstone, in- 
 stead of flint, and finally the white chalk, the pur- 
 est of limestone beds, containing only 1 or 2 pr. ct. 
 of magnesia, with more or less sand. 
 
 In Europe, the Chalk forms an extensive and in- 
 teresting formation in what is called the great cen- 
 tral basin of Europe, which is bounded as follows : 
 On the North by the primitive ridges of Russian 
 Finland, Sweden, Norway and Scotland ; on the 
 West by the chains of Cumberland, Wales, De- 
 vonshire and Brittany ; on the South by primary 
 mountains in the centre of France, the Alps, and 
 the various insulated groups of Germany, &c. as 
 the Black Forest, the Rhingau, and the Vosges, 
 the Bohemian, Thuringian, Saxon, Silesian, and 
 Carpathian Mountains ; and on the East by the 
 Ural and its branches. In this great tract, thus 
 circumscribed, is another resting on chalk. 
 

 244 
 
 Chalk in the upper beds, invariably embraces 
 nodules of flint in great abundance. Iron pyrites 
 exists in all the beds. 
 
 The organic remains are confined to few gen- 
 era, but many species ; teeth of the shark, ammo- 
 nites, scaphites, belemnites, trochus, cirrus, turbo, 
 serpula and spirorbis, ostrea, pecten, terebratula, 
 magas, plagiostoma, dianchora, inoceramus, bala- 
 nus, echinites. These last are considered as cha- 
 racteristic of chalk, and equal in number all the 
 other remains : one genus, and many species are 
 peculiar to it. Of the astrea there are several 
 species. Of the zoophytes, the encrinus has se- 
 veral genera in the chalk. The alcyonia and 
 spongia are numerous. The remains found in 
 chalk in England and on the Continent of Europe 
 are similar, and preserve their analogy through all 
 the different beds. In the most ancient, the bones 
 of the monitor, of sea turtles, and teeth and ver- 
 tebrae of fishes are every where found. 
 
 The chalk formation has not yet been discov- 
 ered in our country, and some deny its existence. 
 It is presumption however in any man to assert 
 that it is not to be found : thus far the search for 
 it has been unsuccessful ; but when Geologists 
 shall more thoroughly examine the structure of 
 our continent, it surely is not too much to say, that 
 

 245 
 
 is very possible this rock may be found. But even 
 should it never be discovered, the geological 
 chain is still unbroken. We are not to expect 
 precisely the same rocks in all countries, nor are 
 we even to expect geognostic equivalents for every 
 individual rock that may be absent since, as has 
 before been stated, upon high authority, one form- 
 ation may represent many others. At any rate, 
 Chalk must retain an important place in all sys- 
 tems or outlines of Geology. 
 
 It forms in Europe a very remarkable and con- 
 spicuous formation, and because we do not find it 
 on our continent, are we therefore to discard it 
 from systems? As well might we, in treatises on 
 governments, discard the despotic, or the mon- 
 archical, because in the United States, we find 
 only the republican. No individual should arbi- 
 trarily introduce new names into any science, 
 without the most profound study and reflection 
 upon the consequences : nor has any one the pri- 
 viledge of discarding certain terms upon his own 
 authority. Most persons are willing enough to 
 listen to and examine proposed or suggested no- 
 velties, which may be correct, or not. It is per- 
 haps better to retain an old name that is not strict- 
 ly scientific, than to deluge us with new terms to 
 
 33 
 

 246 
 
 perplex the student without gaining any other 
 object. 
 
 
 It will be observed that the Secondary Rocks 
 compose an extensive and valuable portion of our 
 Union. The country of the Mississippi, which is 
 but a portion of an immense region of valley or 
 flat country, that extends from the Gulph of Mexi- 
 co, north-easterly to the Atlantic, and north-wes- 
 terJy to the Pacific Ocean, is of secondary forma- 
 tion. Extending for hundreds of miles, it enjoys 
 at one extreme the brilliant sunshine of the south, 
 and at the other the frozen rigors of winter. It 
 possesses a fertile region, decked with all the 
 beauties of vegetation, and offering the choicest 
 grains and fruits and flowers to the occupant. 
 The mild beauty of its elevations, crowned with 
 oak and ash and hickory, the luxuriant fertility of 
 its vales bearing abundance of grain, and watered 
 by large and picturesque rivers, presents to us 
 some of the finest and sweetest scenery of our 
 country. 
 
 As no section of our Union is more productive 
 Jban our Secondary, so none is more blessed with * 
 Contentment, and prosperity. 
 
 Its soil is fertile, and its rocks rich in treasures. 
 
247 
 
 The TERTIARY FORMATIONS commence where the 
 Secondary ends, viz. at Chalk. It may be consider- 
 ed as a good rule, that all rocks older than the old 
 red sandstone, are primary all those between the 
 red sandstone and chalk are secondary, and those 
 above chalk, tertiary. Volcanic rocks and Alluvia 
 are of separate and distinct classes from each and 
 all others. 
 
 The tertiary formation is composed of different 
 compounds, in which lime and sand and clay are 
 the chief materials. It is but a few years since 
 these strata have been separated from the alluvia. 
 It was first noticed in the vicinity of Paris that 
 they were too large and regular to be of alluvial de- 
 posit, and the researches of Cuvier and Brong- 
 niart established them as belonging to a new class 
 of formations. The accurate observations of Mr. 
 T. Webster,* then occupied in making drawings 
 for the splendid work of Sir H. Englefield on the 
 Isle of Wight, soon determined that the beau- 
 tiful island was not only of tertiary formation, 
 but that it was precisely similar to the tertiary 
 
 *The accuracy of this accute Geologist has lately been ques- 
 tioned in one of the most learned periodical journals in Eng- 
 land. But it must be evident to Geologists that the author oi 
 the attack (Dr. Fitton) is often in error, and contradicts him- 
 self, so as in a great measure rather to corroborate the state- 
 ments of Mr. Webster, than to disprove them. 
 
24U 
 
 tbrmations of France. To this gentleman and 
 to Mr. Buckland we owe the first scientific de- 
 scription of these formations in England. 
 
 The North of Germany, to some distance from 
 the shores of the Baltic the great valley of 
 Switzerland, near the Lake of Constance some of 
 the Subappenine hills in the valley of the Po, and 
 accompanying the shores oi the Adriatic to Otran- 
 to Sicily, Dalmatia and parts of Greece exhibit 
 similar beds, in which we find the same fossils and 
 the same compounds. 
 
 This class is remarkable for the beauty and 
 variety of its organic remains. 
 
 As these formations are composed of an indefi- 
 nite number of strata succeeding each other with- 
 out any very determinate order, we are naturally 
 led to expect a diversity of combinations and 
 names. 
 
 The first division of this class was made by 
 Cuvier and Brongniart, who enumerate the fol- 
 lowing in France. 
 
 Plastic clay, with sand, (argile plastique) fresh 
 water deposit. 
 
 Coarse marine limestone, (cakaire grassier,) 
 with marine sandstone, or (gres marine in/ercur) 
 marine deposit. 
 
, \ 
 
 
 
 Siliceous limestone, (calcaire silicieux) not ascer- 
 tained.) 
 
 Gypsum and marie containing bones of ani- 
 mals, (marnes du gypse d' ossemens,) Fresh water 
 
 and marine. 
 
 Marine marl, abounding in bivalve shells ; the 
 superior layers containing oyster shells in abun- 
 dance. (Marine.) 
 
 Sandstone and sand, without shells, (not deter- 
 mined.) 
 
 Upper marine sandstone, (gres marine superieur) 
 marine. 
 
 Millstone or Buhrstone without shells, (muliere 
 sans coquilles,) not determined. 
 
 Upper fresh water formation, millstone, flint, 
 and limestone, (terrein (Teau douce superieur, 
 menliere silex et calcaire,} Fresh witer. 
 
 These are supposed to be alternate deposits 
 from the salt water of the ocean and of fresh wa- 
 ters of lakes. 
 
 The plastic clay rests on the chalk. It is white, 
 grey, yellow, red and black, containing a layer of 
 sand, and a few very organic remains. The clay 
 is tenacious, unctuous, and slightly siliceous, and 
 is used in the manufacture of pottery and porce- 
 lain. The sand has all varieties of color. 
 
250 
 
 The coarse marine limestone and marine sandstone 
 composed of several distinct strata. The first a 
 coarse sandy limestone containing green particles, 
 and many shells retaining much lustre, and differ- 
 ing from existing species. The following are en- 
 umerated : nummulites, madrepora, astrea, car- 
 yophillia, fungites, cerithium, lucina, cardium, vo- 
 luta, crassatella, turritella, ostrea. 
 
 The second, greyish yellow limestone, partly 
 oolitic, and containig cavities filled with loam, 
 sand, and flint. It contains nearly all the 500 
 different species of bivalves found at Grignon : 
 the following shells may be mentioned cardita, 
 orbitolites, turritella, terebellum, calyptrea : pec- 
 tenculus, citherea, miliolites, cerithium. 
 
 The third is less abundant in fossil varieties 
 miliolites, cardium, lucina, ampullaria, cerithium, 
 corbula. The second and third sometimes em- 
 brace a sandstone containing, among others, the 
 following shells calyptraea, oliva, ancilla, voluta, 
 fusis, cerithium, ampullaria, nucula, cardium, ve- 
 nericardia, cytherea, venus, lucina, ostrea. 
 
 The fourth embraces marls, hard and soft, and 
 calcareous sand, occasionally agglutinated, and 
 containing layers of hornstone, and crystals of 
 quartz, calcareous spar, and duor spar, with very 
 few fossils. 
 
The siliceous limestone without shells occurs always 
 on the same level, and alongside of the preceding. 
 It consists of strata of white limestone, and of 
 grey, or compact, or granular limestone, penetra- 
 ted by silex, which, in different shapes, tills the 
 cavities. It has no fossils* It seems to be only a 
 part of the preceding rock. 
 
 The gypsum formation, and the marine marl forma- 
 tion, are treated of together : being gypsum, and 
 beds of clay marl and calcareous marl, in a regu- 
 lar succession, when all are present. The gyp- 
 sum constitutes the greatest mass, occurring in 
 longish or conical bodies, and not in extensive 
 fields. Montmatre, in Paris, is an example, and 
 there three beds are placed over each other. 
 The first, contains alternate layers of gypsum, cal- 
 careous marl,and argillaceous marl: sea shells are 
 found in it as are fresh water shells in the white 
 marl. The second has more beds of marl than 
 the firsthand contains sulphat of stroritian and fos- 
 sil fishes. The third is the most extensive, and 
 contains many beds of marl. The quarries in 
 this upper gypsum afford those remarkable skele- 
 tons and bones of unknown birds and quadrupeds. 
 The following fossils are found in these united 
 formations. Palgeotherium, magnum, medium. 
 
252 
 
 crassum, curtum, and minus. Anaplotherium, 
 commune, secundarium, medium, minus, minimum. 
 A pachidermatous animal allied to the hog. Ca- 
 ms parisiensis. Three or four species of birds. 
 Trionix parisiensis, and another tortoise. A sau- 
 rian animal, allied to the crocodile. Three or 
 four species of fishes. Cyclostoma,limneus,planor- 
 bis, spirorbis, cerithium, cytherium, ampullaria, 
 cardium, nucula, ostrea, cancer. 
 
 Sandstone and Sand without shells rests on those 
 already described, in strata of considerable thick- 
 ness. 
 
 The Upper Marine Sandstone and Sand varies in 
 composition, and color arid compactness, being a 
 greyish, or red sandstone, sometimes argillaceous, 
 sometimes calcareous. This sandstone contains 
 fossils differing from those found in the sandstone 
 formerly mentioned, viz. olivia, cerithium, pectun- 
 culus, crassatella, donax, citherea, corbula, ostrea, 
 melania ? fusus ? 
 
 Millstone without shells embraces millstones, sand, 
 iron shot, and a clay marl, greenish, reddish, or 
 whitish. It seems to be only a portion of the fol- 
 lowing division. The millstone is a quartz with 
 
253 
 
 many irregular cavities, traversed by reticulated 
 siliceous fibres, and sometimes filled with ochre, 
 clay or marl. There are no organic remains in 
 the millstone. 
 
 The Flint and Siliceous Limestone formation con- 
 sists of these two substances, independent of 
 each other, or intimately united. The limestone 
 most common is nearly pure, often embracing flint, 
 of which however large masses are rare. The 
 limestone is white or yellowish, and whatever may 
 be its original hardness, it softens by exposure, 
 and forms a manure for the agriculturalist. The 
 essential character of the formation is the contained 
 multitude of fresh water and land shells, nearly all 
 of which belong to genera now inhabiting moras- 
 ses ; but no marine shells, except when in imme- 
 diate contact with the marine formation. The fol- 
 lowing belong particularly to the upper fresh wa- 
 ter formation. Cyclostoma, potamides, planorbis 
 limneus, bulimus, pupa, helix, dycotyledons sili 
 cified, arundo. No bivalve occurs among the 
 number. 
 
 It has been justly observed that the Plastic clay, 
 limestone, gypsum, sandstone, and flint and silice- 
 ous sandstone, seem well characterised ; and that 
 34 
 
254 
 
 the terms fresh water and salt water formations 
 might perhaps be supplied by more appropriate 
 names. The hypothesis whence these names are 
 derived seems supported by the organic remains 
 of the strata. 
 
 Of th e Tertiary Formations in England we have 
 an elaborate description by Messrs. Conybeare 
 and Phillips. They name four, viz. the Plastic 
 sand and clay, resting upon which is the London 
 clay, and over this the fresh water formation, and 
 the upper marine formation. 
 
 The Plastic Clay is formed of an indefinite num- 
 ber of beds of sand, clay and gravel, alternating 
 without order. Mr. Webster remarked the simi- 
 larity of this iormation to that of Paris. The sand 
 of Alum Bay, in the Isle of V\ ight, exhibits every 
 variety of color. The clay is laminated, and of va- 
 rious colors and purity, offering the several kinds 
 of clay for the arts. There are few minerals : iron 
 pyrites, selenite, gypsum, and a few spangles of 
 mica. The organic remains are not numerous 
 nor regular, being found indiscriminately in the 
 clay, sand, and pebbles. The following are the 
 /usually contained fossils, murex, infundibtilum. 
 
255 
 
 uehthium, turritella, planorbis, astrea, peetunculus, 
 mya, cytherea, cjclas. 
 
 The London clay is so called from its forming the 
 substratum of London and its environs. It is a 
 tough, bluish or blackish clay, varying in its char- 
 acters ; some strata partaking of the nature of marl. 
 The lower parts frequently run into a siliceous 
 sandstone. 
 
 It may be stated to be an extensive, argillace- 
 ous deposit, embracing subordinate calcareous 
 beds, occasionally passing into solid rocks, or va- 
 ried in aspect by an accidental mixture of sand 
 arid calcareous matter with the clay. 
 
 In its relations and fossils this is supposed to 
 approximate nearly to the cakaire grassier of 
 Paris. It contains iron pyrites, amber, selenite, 
 and lignite with the woody fibre. 
 
 The fossils are interesting and numerous. The 
 crocodile and the turtle, and several species of 
 fish are found. Zoopytes are rare. The vegetable 
 remains are numerous and beautiful. In the island 
 of Sheppey alone upwards of 700 varieties of fos- 
 sil fruit have been observed. The following 
 shells are mentioned viz : ammonites, nautilites, 
 nummulites, seraphs, cyprea, conus, terebelluiB, 
 
256 
 
 auricula, voiuta, oliva, ancilla, buccinum, melanm, 
 cassis, murex, pleurotoma, fusus, rosteilaria' 
 strombus, cerithium, infundibulum, trochus, sola- 
 rium, turritella, turbo, scalaria, ampullaria, vivipa- 
 ra, natica, ostrea, pecten, pectunculus, avicula, 
 modiola, nucula, area, chama, mya, lingula, solen, 
 cardium, cardita, isocardia, venericardia, venus* 
 corbula, serpula, dentalium, teredo. 
 
 The fresh water formation, in general terms, con- 
 sist of marie, argillaceous limestone, and sand ? 
 crossed by calcareous spar. It contains no gyp- 
 sum, which is so plentiful and abundant in re- 
 mains, in the French corresponding beds. This 
 formation has been seperated into the upper and 
 lower divisions. 
 
 The latter consists in a series of beds of sandy, 
 argillaceous, and calcareous marls, containing a 
 coaly matter. Some of them seem to be wholly 
 composed of comminuted fresh water shells, con- 
 tainining some that are entire, among them are the 
 lymneus, planorbis and cyclostoma, helix ? and my- 
 tilus? 
 
 The upper division is an extensive calcareous 
 bed, of yellowish white marl, that is soft, but in- 
 cludes harder and more durable masses. It con- 
 tains veins of cabonat of lime The organic contents 
 
257 
 
 are found in all parts of the bed, and consist ex- 
 clusively of fresh water shells, as lymneus, planor- 
 bis, helix. Some seeds are found, and parts of 
 coleopterous insects. 
 
 The other shells found in the entire formation 
 are potamides, paludina, melanopsis, phasianel- 
 la ? ampullaria, unio. 
 
 The upper marine formation is composed of sandy 
 and gravelly deposits enclosing fresh water shells, 
 and sometimes embracing beds of shell marie. 
 The sand is sometimes ferruginous, and cemented. 
 It resembles the corresponding formation of 
 France. It contains no minerals. The following 
 fossil are mentioned. A large tooth, fragments of 
 bones, spongia, alcyonia. Most of the shells 
 are recent. Patella, emarginula, calyptrea, buc- 
 cinum, murex, cassis, natica, turbo, cyprea, scal- 
 laria, turritella, vivipara, voluta, trochus, infundi- 
 bulum, my a, unio, lingula, my til us cardium, 
 venericardia, venus, area, astarte, mactra, solen 
 tellina, nucula, balanus, pholaa, dentalium. 
 
 Of the Tertiary Formations in the United States, 
 the most extensive is the Plastic Clay, exhibiting 
 its brilliant clays and sands, with its beds of peb- 
 
258 
 
 bles, and its lignite. At Martha's Vineyard, where 
 it has been examined by Mr. Hitchcock, it presents 
 
 cliff200 feet in height, composed of an irregular 
 succession of beds of clay, sand and pebbles, with 
 lignite. The clays are white, brown, blackish, 
 red and yellowish of many shades. The sand too 
 has various colors. The pebbles have a ferrugin- 
 ous coat The lignite is well characterised. There 
 occur small plates of silvery mica, and a small and 
 occasional quantity of amber. The subtratum is 
 not known. 
 
 On Long Island this formation is well marked, 
 and there is scarcely a man on the island but 
 knows that at the depth of from 1 5 to 60 feet char- 
 red wood, with perriwinkle and other shells are 
 found in beds of clay, sand, and gravel. 
 
 Large quantites of clays are annually sent from 
 Amboy, (New Jersey.) and their use ip manufac- 
 tures is well known. The whole triangle formed by 
 the Ocean and the Delaware and Raritan rivers is 
 composed of sand, clay and gravel, alternating, 
 and occasionally consolidated by a ferruginous ce- 
 ment. It contains lignite and shells. The banks 
 of the Delaware river, for several miles, are com- 
 posed of brilliant sands, with beds of clay and lig- 
 nite : the clay is white, yellow and blue, with 
 shades. This formation extends southward, skirt- 
 
 
259 
 
 ing the Atlantic through our southern states. It has 
 been examined at various points, and presents the 
 same characters at Martha's Vineyard, Long Island, 
 Staten Island, New Jersey, near Philadelphia* at 
 Cape Sable, and in Florida. 
 
 Its similarity to the English arid French Plastic 
 clay is acknowledged now by all those who have 
 kept pace with the rapid strides of Geology for 
 the few last years, and who are willing to ex- 
 amine facts without reference to theories. The fol- 
 lowing fossils have been found. Murex, venus, car- 
 dium pectunculus, ostrea, area, pecten, donax, 
 teeth of sharks, crocodiles, and cetacea. 
 
 The London Clay, or a corresponding formation 
 has been supposed to exist at Washington, and to 
 form the general substratum of the city. It was 
 noticed and mentioned several years ago, as a mud- 
 dy clay, containing occasional pebbles and shells 
 with trunks and branches of trees resembling 
 coal, and with iron pyrites. The teeth of sharks 
 and a large rib were many years ago taken from 
 the clay. Mr. Finch has compared it to the forma- 
 tion of Highgate near London. 
 
 f t : ' ir r 1 ' . ' .-A."-', }. 
 
 The coarse marine limestone (calcaire grossier) and 
 the siliceous limestone (calcaire silicieuse) seem to 
 
exist in Georgia, judging from the millstone or buhr 
 stone sent from that state. In some parts of this 
 formation are cavities are filled with stalactites or 
 incrustations in other places it abounds in shells, 
 among them mactra and tellina have been obser- 
 ed, with madrepores and a pectunculus. Horn- 
 stone and quartz are found imbedded. The calcaire 
 grossier has been observed by Humboldt in So- 
 America, and there contains ostrese, madrepores 
 and turbinites. 
 
 In New Jersey are several localities of a clay 
 nearly filled with shells or perhaps more correct- 
 ly of large masses of shells with clay. They rest on 
 gravel beds ; and are used as manures, under the 
 name of marl. These beds are immediately under 
 the soil, and afford the remains of the mastodon, 
 the crocodile, the shark, the monitor and cetacea : 
 pectens, terebratulae. donax, area, turbinolia, ros- 
 tellaria, ammonites, pyrula ; also lignite and amber. 
 Similar localities exist in the counties of Orange 
 and Ulster where bones of the Mastodon have been 
 found : the pecten, ostrea, venus, planorbis, helix* 
 and voluta. 
 
 This seems to correspond with what is termed 
 by the English Geologists, the upper fresh water 
 formation. 
 
 
261 
 
 An interesting account of these formations will 
 doubtless soon be published by those who have 
 had more extensive opportunities and leisure to 
 examine them. From a collection of shells lately 
 made in Maryland, the following have been de- 
 scribed in the Journal of the Academy of Natural 
 Sciences at Philadelphia. Turritella, natica, 
 oliva, buccinum, fusis, fulgur, calyptrcea, dispotoa, 
 fissurella, ostrea, pecten, plicatula, area, pec- 
 tunculus, nucula, venericardia, crassatella, iso- 
 cardia, tellina, lucina, venus, cytherea, astarte, 
 mactra, ampiiiderma, corbula, panopcea, ser- 
 pula, dentalium. In Europe the isocardia has, I 
 believe, been found only in the London clay ; and 
 the astarte in the upper marine formation : should 
 these be considered as characterestic, this collec- 
 tion of fossils would indicate their positions to have 
 been the Plastic clay, London clay, and upper 
 marine formations. 
 
 The siliceous sand of the upper marine forma- 
 tion, shifting with every wind that blows, is seen 
 on many parts of Long Issand, in iNew Jersey, Vir- 
 ginia and the Carolinas. 
 
 In fine, the whole tract of country, with few and 
 small exceptions, between the Allegany ridge and 
 the ocean is of tertiary formation. Commencing, 
 certainly as far north as Martha's Vineyard, per- 
 
 j 
 
 
262 
 
 haps even embracing the gypsum and sand of Nova 
 Scotia, it extends through Long Island, and New 
 Jersey, and stretching through our Atlantic States, 
 forms a class corresponding in size with our gigan- 
 tic primary and secondary. 
 
 Some certain rocks are usually referred to a 
 peculiar class, under the term SUPERINCUMBENT or 
 OVERLYING ROCKS. They are unstratafied, and pos- 
 terior to the rocks in connection with which they 
 are found. They pass almost imperceptibly into 
 each other, with a few exceptions that scarce de- 
 serve notice. It may be said that they occur as re- 
 cent secondary rocks; some of them are of older 
 origin, but there are no unexceptionable rules for 
 distinguishing them, and it is perhaps best to class 
 them together. This is the more necessary as 
 neither composition nor position authorize the dis- 
 tinction of separate families. 
 
 The rocks of this division occur in more or less 
 extensive localities; and are by some considered 
 as independent formations. While other geologists 
 suppose them universal, as they are found forming 
 tracts in all countries. 
 
 They are observed in contact w r ith every rock 
 from granite to the most recent secondary. We do 
 
263 
 
 not know if they ever rest on the tertiary; they 
 have not been noticed in that position. 
 
 In granite they occur in veins. In the stratified 
 rocks of both primary and secondary classes they 
 appear as masses also, and sometimes even as 
 beds. It is said that in the Isle of Skye they form 
 strata parallel, and not connected with veins, but 
 alternating with jasper, siliceous schist, and fer- 
 ruginous clay. 
 
 These rocks sometimes constitute mountains, or 
 hills ; and sometimes form the summits merely. 
 Mount Holyoke, Mount Tom, East and West Moun- 
 tains, near New Haven and the superb Palisa- 
 does on the Hudson river are familiar examples. 
 
 They sometimes resemble granite, being dispos- 
 ed in beds, and divided into cuboid al masses, which 
 occasionally become rounded by the weather, in 
 the same way as that rock. 
 
 They are sometimes also prismatic and columnar; 
 of which the Island of Staffa, and the Giant's 
 Causeway are among the most splendid examples. 
 The columns may be regular, and in contact : or 
 they may be irregular in the same bed : some- 
 times they are so confused as to resemble a mere 
 heap of broken columns. In many instances the 
 prisms are straight, and in contact, thus bestowing 
 a beautiful architectural appearance ; as in Fin- 
 
 I 
 
's Cave. In some instances the prisms are 
 bent, in one or more directions. 
 
 The form of the columns varies from three the 
 twelve sides which are often so placed as to pre- 
 sent an absolute whole, marked by lines. This 
 structure occurs in all the members of the family 
 not in basalt only, as is frequently supposed, but in 
 sienite, claystone-smd greenstone. 
 
 The laminar structure occurs in this family : the 
 laminae varying from the thickness of paper to 
 very large. This structure is found in all varieties 
 of these rocks. The laminae are parallel, or 
 transverse to the columns, when combined with 
 the columnar structure. 
 
 There is a peculiar internal structure in these 
 rocks, exhibited by decomposition. It is often the 
 case that a column or joint wastes away, so as 
 to show, by successive exfoliation, a spheroidal 
 figure. 
 
 Sometimes, some of those varieties having a 
 base of indurated clay, become changed, by dis- 
 integration to some depth, and are so soft as, by 
 many, to be mistaken for clays. 
 
 The cavernous, amygdaloidal and porphyritic 
 structures, are also seen in these rocks. 
 
 The cavernous is similar to the variety occur- 
 
 mm 
 
 
265 
 
 ring in some lavas the cells being elongated, or 
 contorted, and coated with a vitreous varnish. 
 
 Occasionally the cells contain those substances 
 that are found in the amygdaloids ; thus these two 
 structures sometimes pass into each other, some- 
 times into the porphyritic. 
 
 There are so many rocks in this class that we 
 cannot give any general rules as to texture or com- 
 position. 
 
 Indurated clay is the chief substance in this 
 family, passing into claystone, clinkstone and fel- 
 spar : the extremes of this series are essential in- 
 gredients. Of the less frequent constituents, horn- 
 blende is the most common varying in quantity 
 and in the size of the crystals. 
 
 In sienite, hornblende forms a small share of the 
 rock and is sometimes crystallised. In greenstone it 
 is very minute and confused : when it is very abun- 
 dant, and minutely divided, the rock passes into ba- 
 salt. When most excessive and fine, the basalt is 
 well marked : but there are great differences of as- 
 pect. When the base of compact felspar or clink- 
 stone becomes very dark, and the hornblende near- 
 ly disappears, the mass passes into clinkstone : and 
 thus many dark clinkstones are termed basalt : 
 thus accounting for the endless variety of basalt? 
 mentioned by authors. 
 
266 
 
 The presence of hornblende thus constitutes 
 the series of sienite. greenstone and basalt, also 
 called trap rocks, of the superincumbent class. 
 But there are no characters for distinguishing in- 
 variably the two latter. In each the base is clay- 
 stone, clinkstone, or compact felspar, united by 
 hornblende, and exhibiting a similar structure. 
 The distinctive character chiefly relied on at pre- 
 sent is color: those rocks in which the constituents 
 are pale whitish, yellowish, or reddish, being sien- 
 ite : and those in which they are grey, greenish, or 
 dark colored, being greenstone. Dr. Macculloch 
 proposes that instead of eolor the quantity of the 
 ingredients be taken as a guide : the excess of the 
 three minerals abovementioned to constitute sien- 
 ite ; and those compounds into which hornblende 
 enters in equal or greater proportion to be named 
 greenstone. But even in this case there will often 
 be doubt as to the nature of some rocks. 
 
 Another mineral often forming an ingredient in 
 this class, is augit, which is supposed to have been 
 often mistaken for hornblende. It occurs in the 
 same mariner as that mineral, usually of a dark 
 green or black color. It is sometimes sparingly 
 present, and then the compound resembles sien- 
 ite : at others it so finely divided that the rock 
 
267 
 
 seems homogeneous, and can scarcely be distin- 
 guished from basalt. It has been proposed to 
 give to such rocks the compound name of augitic 
 sienite, augitic greenstone, and augitic basalt. 
 
 Hypersthene is also mentioned as an ingredient, 
 often compounded with hornblende, of which it is 
 a species. 
 
 Felspar is an ingredient in the porphyries, and 
 gives to this rock its peculiar character : but it oc- 
 curs also in sienite and greenstone without attaching 
 to them the porphyritic structure. In these cases 
 the structure is granitic Occasionally the felspar is 
 of the glassy variety, sometimes crystallised, at 
 others simply occupying the place of common 
 felspar. 
 
 Mica is rarely found in porphyries : still rarer 
 in greenstone. Quartz too is found in greenstone 
 and porphyry in the same w&y that it occurs in 
 granite, from which these compounds are some- 
 times difficult to be distinguished. 
 
 The minerals found in these rocks are mesotype, 
 prehnite, stilbite, epidote, calcareous spar, and a 
 very few others occasionally. 
 
 For a more full account of the sub-divisons, I 
 refer to the synopsis of these rocks at the close of 
 the volume. As much difficulty has arisen in dis- 
 
Sit 
 
 tinguishing the members of this class, I have 
 deemed it adviseable to give the synopsis of Dr. 
 Macculioch with slight omissions, as it may aid 
 enquirers in their researches on this class. 
 
 1 
 
 The history and formation of ALLUVIAL DE- 
 POSITS is extremely interesting. 1 have already 
 slightly noticed them. They occur in various sit- 
 uations, bespeaking different origins. 
 
 When found in vallies, through which rivers run, 
 they usually arise from the abrasion of the chan- 
 nels in which these flow : and particularly from 
 hills whence their sources are derived. They 
 arise from the same cause when they form exten- 
 sive plains, accompanying the estuaries of rivers : 
 or when filling lakes : we often see these in the 
 interior of countries where the lakes have been 
 gradually filled with alluvial, and dried up 
 
 The waters of some rivers and lakes hold lime 
 in solution, which is gradually deposited this is 
 the well known Travertine of Rome ; and per- 
 haps the stalagmitic rocks of Gibraltar and else- 
 where. 
 
 On sea shores the waves cast up loose materials 
 formed of sand and fragments of shells, on which 
 
 It 
 
269 
 
 plants grow and add a soil towards the completion 
 of a bank, that eventually rises far above the 
 water. 
 
 At the foot of mountain alluvial is formed by 
 the daily waste of the materials, urged solely by 
 the force of gravity, and the ordinary drainage of 
 the surface. 
 
 Occasionally rocks are entirely decomposed in 
 situ. The mass of constituents thus crumbled to- 
 gether, lie loose and are mostly formed of gra- 
 nite, gneiss, or red sandstone. 
 
 Thus we have announced four kinds of alluvia, 
 viz. that of rivers and estuaries, marine alluvia, 
 alluvia of descent, and untransported alluvia. 
 Their extent, depth and form are various. A dis- 
 tinct stratafication is often observed. The parti- 
 cles are of all sizes, sometimes fine as sand, and 
 sometimes many cubic feet. If they are round or 
 angular depends on the distance they have been 
 transported, and on the time and degree they have 
 been exposed to the several causes of waste, and 
 on the nature of the materials. 
 
 I have mentioned before, that they often con- 
 tain minerals, of which tin, gold, and diamonds 
 are the most remarkable. 
 
 36 
 
270 
 
 From the partial alluvia, which we can trace and 
 account for, we must separate the DILUVIA, found 
 in places where none of the cause abovementioned 
 could have acted, and which owe their origin, in 
 some cases, to partial and temporary floods ; in 
 others to that great and eventful deluge described 
 by Moses, with whose account, as we have seen in 
 a former lecture, so strongly coincide the dicover- 
 ies of geology, which has thus rendered an unex- 
 pected and important, though unneeded, support 
 to the Sacred History. 
 
 We have thus surveyed, with a cursory glance, 
 the different geological theories accounting for the 
 present appearance of our globe. We have seen 
 that they all refer to that general deluge which 
 forms so conspicuous an epoch in the history of our 
 planet. We have observed that the great waters 
 covered our earth and have noticed its gradual 
 subsidence, or the elevation of the land. We have 
 seen the retiring waters forming vallies have fol- 
 lowed the divisions of land and examined the 
 Alpine district of tnountains, the lowland plains, 
 and the bottom of the sea. 
 
 We have also examined, at least mentioned, all 
 
 known rocks from the primary, formed before tho 
 
 . 
 
271 
 
 existence of animal or vegetable organization, to 
 the secondary, which contain the organic remains 
 of generations passed away, and which have been 
 termed the medals of nature : to the tertiary 
 which was last produced, and the alluvia that is 
 daily deposited at the present. 
 
 We have also noticed the causes now operating, 
 and changing the surface of our planet, viz. the 
 action of the elements, water more particularly, and 
 the formation of peat and of coral reefs, and have 
 examined the agency of volcanoes and earth- 
 quakes. And in so doing, have superficially tra- 
 ced the outlines of geological science. The de- 
 scription and history of the various mineral con- 
 tents of rocks do not come within my duties, but 
 belong to mineralogy. 
 
 Should I be asked for a book of reference con- 
 taining the elements of geology, I must answer that 
 I know of no work that is fit for a beginner in the 
 study. Humboldt, Macculloch, Conybeare and 
 Phillips, and Bakewell, all presuppose too much 
 and are calculated for the perusal of geologists, 
 rather than students. Their works however may be 
 advantageously consulted. The various periodicals 
 of the United States contain more or less informa- 
 tion on this subject among others I cannot. refrain 
 from noticing a little and unpretending pamphlet 
 
272 
 
 occasionally published. <; The Annals of the Ly- 
 ceum of Natural History, of New-York," a so- 
 ciety that is actively and honorably engaged in ex- 
 amining and elucidating the natural history of our 
 country. Nor can I omit to mention the Journal 
 of the Academy of Natural Sciences of Philadel- 
 phia : Nor the American Journal of Science, so 
 ably conducted by Prof. Silliman. 
 
 I am as sensible as any ,of you can be of the de- 
 ficiencies and imperfections of this course : but I 
 make no apology, conscious of your being all 
 aware, that no subject, no scientific subject, can 
 be properly treated of and condensed into four 
 or six lectures. 
 
 We might have passed our hours with more 
 amusement, but then we must necrssaril) have de- 
 parted from the dry detail of this science. 
 
 I regret that more time was not allowed to en- 
 large upon and illustrate the real value and utility 
 of this science. And if in my Lectures I have failed 
 to render the study of Geology interesting, I have 
 the candor to acknowledge, and sincerelv wish 
 you all to believe, that the fault lies not in the 
 subject, but in the person who has the honor to 
 address yon. 
 
u A ,1 
 
To facilitate the study of Geology, a Synopsis 
 of each individual Rock is here added, affording a 
 view of the different compounds that may be 
 classed respectively under each head. 
 
 SYNOPSIS OF GRANITE, 
 
 First Division. 
 Of two ingredients. 
 
 A. Felspar arid mica. 
 
 B. Quartz and felspar. 
 
 a. An uniform mixture of these ingredients. 
 
 6. The quartz, or felspar, or both, imperfectly 
 crystallised, and influencing each other's forms. 
 Graphic granite. 
 
 C. Quartz, arid hornblende. 
 
 D. Felspar and hornblende. 
 
 a. Large grained, or the hornblende crystallised. 
 
 b. An uniform granular mixture : the ingredi- 
 ents varying materially in their sizes and pro* 
 portions. 
 
 c. Intimately mixed, so as to be nearly undis- 
 tinguishable. 
 
275 
 
 Second Division. 
 Of three ingredients. 
 
 A. Quartz, felspar and mica. 
 
 a. An uniform mixture of the ingredients. 
 
 b. The same with additional crystals of felspar 
 embedded, porphyritic granite. 
 
 c. ith two kinds of felspar, the common and 
 glassy. 
 
 </. The quartz, or the felspar, or the mica, or all 
 of them crystallised. 
 
 B. Quartz, felspar and hornblende. 
 
 a. Large grained. The'sienite of some mine- 
 ralogists. 
 
 b. Small grained, and, like D. b. div. 1st, often 
 resembling the greenstones of the trap family, by 
 which name some mineralogists have also distin- 
 guished it. 
 
 C. Quartz, felspar and actynolite. 
 
 D. 'Quartz, felspar and chlorite. 
 
 E. Quartz, felspar and talc. 
 
 F. Felspar, hornblende and mica. 
 
 This variety occurs in the same manner as D. 
 div. 1st, but is rare. 
 
 V* *'' ' ---' i ^>i --,. .:.' ^ ,\- ' T 'J*i{ 
 
 Third Division. 
 Of lour ingredients. 
 
 A. Quartz, felspar, mica, and hornblende : the 
 
276 
 
 sienite of some writers. It passes into var. A. div. 
 2d, or into common granite. 
 
 B. Quartz, felspar, mica, and compact felspar. 
 This is similar to the foregoing, the last substance 
 being accidental. 
 
 C. Quartz, felspar, mica, and actynolite. 
 
 D. Quartz, felspar, hornblende and chlorite. 
 
 E. Quartz, felspar, hornblende and steatite. 
 
 F. Quartz, felspar, mica, and porcelain clay. 
 
 SYNOPSIS OF GNEISS. 
 
 First Division. 
 
 Of regular composition, containing at least three 
 of the four minerals, quartz, felspar, mica and 
 hornblende. 
 
 First Sub Division. 
 Granitic, large grained, resembling granite. 
 
 A Quartz, felspar, and mica. 
 
 B. Quartz, felspar an<l hornblende. 
 
 C Quartz, felspar, mica and hornblende. 
 Second Sub- Division. 
 
 Schistose, fine grained. 
 
 A. White felspar and quartz, in minute grains 
 intimately mixed, with rare scales of mica. The 
 position of the mica determines the foliated struc- 
 ture, often so indistinct that this variety is mis- 
 taken for quartz rock. 
 
277 
 
 'V 
 
 B. The same compound with mica in abun- 
 dance resembling micaceous schist. 
 
 C The mica so abundant as to form continuous 
 laminae ; sometimes mistaken for micaceous schist. 
 
 D A schist of foliated mica, with interspersed 
 and large irregular crystals of felspar ; the quartz 
 scarcely discernable. 
 
 E. An undulated coarse schist, consisting of 
 large grains ot felspar arid of quartz closely pack- 
 ed, and connected by the smallest possible quan- 
 tity of mica. 
 
 All schistose divisions present transitions from 
 gneiss into quartz rock and micaceous schist. 
 Third Sub-Division. 
 
 Laminar the ingredients forming distinct la-* 
 minae. 
 
 A. Quartz and felspar in alternating laminse : 
 belonging perhaps with D. to the 3d division. 
 
 B. Quartz, felspar and mica, simply alternating, 
 
 C. Quartz, felspar and hornblende disposed in 
 the same manner. 
 
 D. Felspar and hornblende in alternating la- 
 minae. 
 
 E. Quartz, mica and hornblende ; the two latter 
 in one laminfa. 
 
278 
 
 Second Division. 
 
 Of irregular composition; consisting of com pact 
 felspar united to some or all of the ordinary ingre- 
 dients of gneiss. 
 
 A. Compact felspar and hornblende, occuring 
 also as a variety of hornblende schist. 
 
 B. Compact felspar and quartz, in various pro- 
 portions. 
 
 C. Compact felspar and chlorite. 
 
 D. Compact felspar, quartz and mica. 
 
 E. Compact felspar, quartz, and hornblende, or 
 mica superadded. 
 
 F. Compact felspar superadded in various ways 
 to any of the preceding varieties of gneiss, con- 
 taining common felspar also. 
 
 Third Division. 
 
 Of irregular composition ; being either deficient 
 in the number of ingredients, or containing some 
 substance not included in the definition of gneiss, 
 
 A. Quartz and felspar, laminar and granular at 
 the same time ; the foliated disposition resulting 
 from the crystalline position of the felspar. 
 
 B. Hornblende and felspar, foliated and some- 
 times imperfectly schistose. Analogy and geo- 
 logical connection claim here a place for this 
 rock, which is by some considered as primitive 
 
279 
 
 greenstone, by others as hornblende schist, under 
 which head it will be found. 
 
 C. Felspar and mica. 
 
 D. Felspar and clay slate. 
 
 E. Felspar and chlorite schist. 
 
 F. Felspar, quartz and chlorite schist. 
 
 G. Felspar, quartz and clay slate. 
 H. Felspar, quartz and talc. 
 
 I. A granular mixture of felspar and quartz in 
 one lamina, and clay slate in another. 
 
 K. The same with chlorite schist instead of clay 
 slate. 
 
 L. The same with greywacke schist. 
 
 M. Compact quartz with embedded grains of 
 felspar in one lamina, and the same schists in the 
 other. 
 
 N. Schistose felspar containing crystals of horn- 
 blende interspersed. 
 
 O. Actynolite occupying the place of horn- 
 blende 
 
 P. Compact felspar, argillaceous schist, and any 
 one or more of the other ingredients of gneiss. 
 
 SYNOPSIS OF MICACEOUS SCHIST. 
 
 First Division. 
 Consisting of mica and quartz. 
 
 
f 
 
 280 
 
 First Sub-Division. 
 Simply laminar or foliated. 
 
 x t7 J 
 
 A. Formed of mica, continuously laminar, with 
 the smallest possible addition of laminar quartz. 
 
 B. The preceding reversed as to ingredients. 
 
 C. The continuity of mica broken, and the 
 quartz granular. 
 
 D. The mica greenish and more tender ; ap- 
 proximating to chlorite schist. 
 
 E. The mica grey, but tender ; approximating 
 to talcose schist. 
 
 F. Similar to the preceding two ; passing into 
 argillite. 
 
 The preceding varieties are particularly liable 
 to contortions. 
 
 Second Sub-Division. 
 Granularly laminar. 
 
 A. Granular quartz mixed uniformly with mica 
 in a parallel position, producing the laminar frac- 
 ture. 
 
 B. Granular quartz, occupying distinct laminae, 
 separable by the aggregation of scales of mica. 
 
 C. Granular quartz, divisible into laminae, be- 
 tween which are interspersed scales of mica. 
 
 D. The same, with the scales of mica so dispo- 
 sed as to give the stone a fibrous appearance. 
 
 
281 
 
 E. The mica imperfectly parallel and scaly, bent 
 round the grains of quartz, giving a peculiar char- 
 acter to the rock in the transverse fracture. 
 
 Second Division. 
 Composed of three or more ingredients. 
 
 A. Many of the preceding varieties containing 
 crystals or concretions of hornblende. 
 
 B. The same containing felspar, and passing in- 
 to gneiss. 
 
 C. Containing chlorite or talc in addition, and 
 passing into chlorite schist, or talcose schist. 
 
 D. Irregularly compounded with more than one 
 of the above-named ingredients. 
 
 E. Containing carbonate of lime, with the usual 
 ingredients, and giving it the appearance of gneiss. 
 
 Third Division. 
 Conglomerated. 
 
 Containing superadded fragments of granite, 
 quartz rock, limestone and other substances. 
 
 SYNOPSIS OF ARGILLITE. 
 
 First Division. 
 
 Simple : of indurated shistose clay alone. 
 A. Straight fissile, or continuously laminar. 
 
a. With a straight even fracture on the la- 
 minae. 
 
 b. With a rough and undulated fracture. 
 The varieties form roof slate. 
 
 B. Imperfectly fissile, or massive slate. 
 
 a. Amorphous, sometimes breaking more ea- 
 sily in one direction than another. 
 
 b. Fibrous. 
 
 c. Massive, splitting with curved surfaces. 
 
 d. Black, imperfectly fissile, of dull earthy 
 aspect. 
 
 e. Black, and so soft as to mark paper : black 
 chalk or drawing slate. Some varieties are fissile. 
 
 /. Spheroidal concretions embedded in the 
 laminar varieties. 
 
 C. More compact, with a smooth splintery, or 
 minutely granular and splintery fracture, translu- 
 cent on the edges. Whet slate, or hone. 
 
 a. Compact, imperfectly fissile, the fragments 
 translucent, and much resembling compact felspar 
 common hone. 
 
 b. Laminar or scaly ; straight or undulated, the 
 fragments translucent used as hone. 
 
 c. Granular, rough : less translucent. 
 
 D. So hard as to strike fire easily ; but the par- 
 ticles of quartz not visible. 
 

 283 
 
 ') 
 
 This is the flinty slate or siliceous schist of some 
 writers. 
 
 ' : <&r' 
 **v 
 
 Second Division. 
 
 Compound : indurated schistose clay, with some 
 other ingredient conspicuously mixed. 
 
 A. Simple argillite and mica. 
 
 a. The mica extremely thin and broad : passes 
 into micaceous schist : the lustre silky or plumba- 
 ginous. 
 
 b. The scales of mica minute, intermixed ir- 
 regularly, or in laminae. The fine greywacke 
 schist of some writers. 
 
 B. Simple argillite and talc; of a greasy feel, 
 and silky lustre : passes into talcose schist. 
 
 C. Simple argillite intermixed with chlorite. 
 
 a. The chlorite invisibly minute, as if pow- 
 dery, the fracture dull and earthy. 
 
 6, The chlorite foliated, or scaly, and the 
 fracture glossy. 
 
 These varieties pass into chlorite schist. 
 
 D. Simple argillite with hornblende. 
 
 a. The hornblende in minute scaly crystals, 
 or irregular grains, or flat plates. 
 
 b. The hornblende fibrous : fascicular : or 
 else straight, or curved, and radiated. 
 
 Some varieties of a. pass into hornblende schist. 
 
I 
 
 E. Argillite, A. div. 1st, intermixed with quartz, 
 
 a. An uniform mixture of sand and blue clay : 
 imperfectly schistose, and resembling an argilla- 
 ceous sandstone. 
 
 b Argillite, massive, or laminar, mixed with 
 quartz sand. The fine greywacke and greywacke 
 schist of some writers. 
 
 c. Quartz gravel of various sizes, similarly in- 
 termixed : coarse greywackes. 
 
 F. Argillite, C. div 1st, intermixed with quarts 
 
 a. With very fine grains or powder of quartz. 
 Not fissile : fracture sometimes rough and splin- 
 tery, and often resembling the fine and grey varie- 
 ties of sandstone. 
 
 b. With visible grains of quartz of different 
 sizes, and resembling the coarser sandstones. 
 
 This also is termed greywacke. 
 
 G Argillite, with embedded particles of cal- 
 careous spar. 
 
 H. Argillite, with embedded felspar, in crystals 
 or fragments, having a porphyritic appearance. 
 
 Third Division. 
 
 Of argillite, wi'h two or more ingredients. 
 A. Argillite with quartz sand, and mica, 
 a. Schistose. 
 . Massive, 
 

 I 
 
 Occasionally termed greywacke. When the 
 quartz is abundant, they pass into micaceous 
 sandstone. 
 
 B. Argillite with quartz and felspar. 
 
 C Argillite, with quartz, felspar and mica. 
 
 These form other varieties of greywacke. 
 
 * . r , '. - ...- 
 
 Fourth Division. 
 
 Containing fragments of the same or of other 
 compound rocks : of a conglomerate structure. 
 
 A. Fragments of argillite re-united. 
 a. schistose ; slaty. 
 
 6. Imperfectly schistose ; or massive. 
 
 B. Fragments of quartz united by argillite. 
 
 a. With simple argillite. 
 
 b. With any of the compound varieties. 
 
 C. Fragments of quartz and of schistose slates, 
 united by var. C. div. 1st massive. 
 
 D. Quartz, felspar, and clay slate in minute frag- 
 ments ; united, with or without any additional ar- 
 gillaceous cement. 
 
 E. Fragments of quartz and basalt, cemented 
 by a mixture of clay slate and quartz sand. 
 
 F. Fragments of jasper and clay slate, with 
 grains and fragments of felspar and of quartz, 
 united by a siliceo-argillaceous base. 
 
 38 
 
286 
 
 v 
 
 G. Fragments of micaceous schist and quartz, 
 united by a mixture of schistose clay and sand, or 
 of clay, sand, and mica. 
 
 H. The same, containing fragments of argilHte* 
 
 This catalogue might be greatly extended ; the 
 
 most conspicuous only have been noticed. It 
 
 comprises the coarse grey wacke and grey wacke 
 
 schist mentioned as transition. 
 
 Fifth Division. 
 Argillaceous conglomerates. 
 All the varieties of the last division, with larger 
 fragments, and consequently a coarse texture. 
 
 SYNOPSIS OF SERPENTINE, 
 
 First Division, 
 Opake. 
 
 A. Common serpentine. 
 
 . With an earthy uniform fracture. 
 t. With a splintery fracture, passing to the 
 conchoidal. 
 
 c. The same, passing to the granular. 
 
 d. With a granular fracture. 
 
 B. Softer, and becoming gradually sectile : the 
 potstone of some mineralogists. 
 
 C. Passing to indurated talc ; the potstone of 
 
287 
 
 others, and mentioned under the head of talcose 
 schist. 
 
 The usual colour of these varieties are green* 
 black, brown, red, and purple of all tints ; yellow, 
 pink, lilac, and pale grey are more rare. The 
 variations and admixtures of these in clouds, spots, 
 and veins are infinite. 
 
 Second Division. 
 Translucent. 
 A. Noble Serpentine. 
 
 a. Foliated and splintery. 
 
 b. Conchoidalor, splintery conchoidal. 
 
 SYNOPSIS OF PRIMARY LIMESTONE. 
 
 First Division. 
 Simple. 
 
 A. Crystalline. 
 
 a. Very large grained, with lamellae straight 
 or curved. 
 
 b. Large grained, the crystals appearing to 
 have compressed each other, as in coccolite. 
 
 c. Middle sized grain Parian marble &c. 
 
 d. Finely granular, saccharine, and firm or 
 loose the marble of Carrara, &c. 
 
 e. Finely granular and compacted, becoming 
 splintery. 
 
 /. The crystals so placed as to exhibit an im- 
 
,288 
 
 perfect shistose structure ; and to appear as if it 
 contained mica. 
 B. Compact. 
 
 a. splintery ; with a rough granular fracture, 
 
 b. Flat splintery ; smooth. 
 aL* c. Splintery and conchoidal. 
 
 Second Division. 
 Compound : of two ingredients. 
 
 A. Limestone, with mica interspersed. 
 
 a. Foilated, irregular, large granular, resem- 
 bling granitic gneiss. 
 
 b. Straight laminar, resembling micaceous 
 schists. 
 
 B. Interlaminated with argillaceous schist. 
 
 C. With hornblende interspersed. 
 
 D. With sahlite or augit of various colors inter- 
 spersed. 
 
 E. With talc interspersed. 
 
 F. With noble serpentine or steatite so intimate- 
 ly diffused as to give a general color to the mass. 
 
 G. With garnets diffused, sometimes crystallis- 
 ed. 
 
 H. With quartz, in grains or so very minute as 
 not to be visible, 
 I. With felspar. 
 K. Impregnated with bitumen. 
 
289 
 
 r.^-j 4^'J^t'U"*" > i ^~ 
 
 L. With tremolite minutely intermixed. 
 M. With actynolite, in the same manner. 
 
 Third Division. 
 
 Compound : of three ingredients. 
 A. Limestone with noble serpentine and mica. 
 B The same with sahlite, 
 C. With hornblende arid augit. 
 
 Fourth Division. 
 
 Compound : consisting of any of the preceding 
 varieties, with fragments of other rocks, or of other 
 limestones. 
 
 Conglomerates. 
 
 A. With limestone fragments alone, united in 
 various ways. 
 
 a. The fragments imbedded in a general con- 
 tinuous calcareoue base. 
 
 b. The fragments agglutinated with little or 
 no proper base, and of various sizes. 
 
 B. Fragments of quartz imbedded in limestone. 
 
 C. Fragments of argillite imbedded in do. 
 
 D. Fragments of several primary rocks, with or 
 without fragments of limestone also, imbedded in 
 a calcareous base. 
 
 Some of these are noticedagain in the Synopsis 
 of Conglomerates. 
 
290 
 
 SYNOPSIS OF QUARTZ ROCK, 
 
 Fiist Division. 
 Simple : of quartz alone* 
 
 A. Pure quartz, similar to that found in veins. 
 
 a. Hyaline. 
 
 b. Opake. 
 
 B. Pure quartz, compact, laminar : finely fissile, 
 almost scaly ; sometimes laminar and striated. 
 
 C. Granular splintery; sometimes passing into 
 the compact. 
 
 D. Granular : with large grains or concretions. 
 
 a. Compact, crystalline, transparent or opaque. 
 
 b. Gravelly, with distinct condensed grains. 
 
 E. Arenaceous, or finely granular. 
 
 a. Condensed saccharine, passing into var. C. 
 
 b. Loose, arenaceous, resembling secondary 
 sandstones. 
 
 Second Division. 
 
 Compound ; of two ingredients. 
 Of quartz and felspar. 
 
 A. The quartz compact, opaque or hyaline, with 
 imbedded particles of felspar dispersed irregular- 
 ly. ,., ; /K;^, 
 
 B. The same, with the felspar assuming a lami- 
 nar direction : and predominating more in one la- 
 mina than in another. 
 
291 
 
 C. An uniform rock, more or less laminar, with 
 a fracture between granular and splintery. 
 
 D. The quartz and felspar both in distinct grains 
 and in various proportions. 
 
 a. Highly compacted, and cemented by silex, 
 or quartz. 
 
 b. Gravelly, or sandy, sometimes loose. 
 Of quartz and mica. 
 
 A. Compact quartz, with scales of mica inter- 
 spersed. 
 
 a. The quartz opaque. 
 
 b. hyaline, (aventurine) 
 
 B. Laminar : occasioned by the position of the 
 mica. 
 
 a. The mica in distinct scales, dispersed, but 
 parallel. 
 
 b.. The mica forming distinct laminae. 
 This latter passes into mica slate. 
 Of quartz and blue schistose clay. 
 
 A. The two substances in alternate laminae. 
 
 B. Quartz, arenaceous, and minutely interlami- 
 nated with clay, similar to the sandstone accom- 
 panying coal. 
 
 C. Quartz sand and blue clay intimately mixed. 
 This last passes into fine grey wacke schist. 
 
292 
 
 Third Division. 
 Conglomerate : with more than two ingredients* 
 
 A. Quartz sand alone, or sand and gravel of 
 quartz and felspar, with imbedded pebbles or frag- 
 ments of quartz. 
 
 B. The same, with fragments of argillite. 
 
 C. The same, with fragments of mica slate, or 
 with both. 
 
 These pass into coarse grey wacke. 
 
 SYNOPSIS OF CHLORITE SCHIST. 
 
 First Division. 
 Simple: of Chlorite only. 
 
 A. Foliated Chlorite ; plain or undulated ; with 
 minute, or with large undulations. 
 
 Second Division. 
 
 Compound : of two ingredients. 
 Foliated or simple laminar and alternating. 
 
 A. Foliated chlorite with laminar quartz. 
 
 B. granular quartz. 
 
 C. laminar felspar, 
 
 D. grains or imperfect 
 
 crystals of felspar disposed in a laminar manner. 
 
 Granula^ly laminar : mixed. 
 
 A. Scaly or imperfectly foliated chlorite with 
 quartz sand. 
 
^ . 293 
 
 a. Large grained, with a rough granular frac- 
 ture. 
 
 b. Small grained, with a homogeneous aspect, 
 and often scarcely fissile. 
 
 c. The preceding varieties, passing into grey 
 wacke schist, and into argillite. 
 
 B. Scaly chlorite with large grains of quartz. 
 Similar in structure and appearance to mica slate 
 E. 1st div: 3d subdiv. 
 
 C. Scaly chlorite, with large imperfect crystals 
 of felspar : similar in structure to the preceding, 
 and resembling granitic-gneiss. 
 
 D. Scaly chlorite, highly compacted, with mi- 
 nute grains of felspar interspersed : difficulty fissile: 
 occasionally granular, and fibrous. 
 
 E. Scaly chlorite with hornblende, intermixed 
 or imbedded, and passing into hornblende schist. 
 
 F. Scaly chlorite intermixed with actynolite: 
 very compact, sometimes fibrous, difficulty fissile. 
 
 G Scaly chlorite with mica : passing into mica 
 slate. 
 
 Third Division. 
 
 Compound : with more than two ingredients. 
 Laminar, alternating. 
 
 A. Foliated chlorite, felspar and quartz. 
 39 
 
 
294 
 
 This occurs in the series of gneiss, and is there 
 introduced. 
 Granularly laminar", mixed. 
 
 A. Scaly chlorite, quartz, and felspar. 
 
 B. felspar and mica. 
 
 C. hornblende and mica. 
 
 D. hornblende, quartz, and 
 
 green compact felspar. 
 
 SYNOPSIS OF TALCOSE SCHIST, 
 
 First Division. 
 Simple: of one ingredient. 
 A. Schistose talc. 
 
 a. Scaly and foliated. 
 
 b. Scaly and semigranular. 
 
 c. Minutely scaly-granular and indurated: 
 potstone of some mineralogists. 
 
 This variety passes into serpentine, and ha* 
 there been mentioned. 
 
 Second Division. 
 Compound: of two ingredients. 
 
 A. Talc, and quartz : foliated ; the quartz vari- 
 ously disposed, and the rock resembling mica 
 schist, into which it passes. 
 
 B. Talc, and foliated or scaly chlorite ; passing 
 into chlorite schist. 
 
295 
 
 C. Talc and felspar. 
 
 D. Talc and argillite : passing into argillite, un- 
 der which head it has been mentioned. 
 
 E. Talc and serpentine : passing into serpentine, 
 
 Third Division. 
 Ccmpound : of three ingredients. 
 
 A. Talc, quartz, and felspar. 
 
 B. Talc, quartz, and mica. 
 
 SYNOPSIS OF HORNBLENDE ROCKS. 
 
 First Division. 
 Simple : of hornblende alone. 
 
 A. Very compact, with a smooth and dull frac- 
 ture : the particles being scarcely discernable. 
 
 B. Granular, from small irregular aggregated 
 crystals: of different degrees of fineness. 
 
 C. Scaly, from an aggregation of flat crystals. 
 
 D. Flat, continuously laminar. 
 
 E. Fibrous. 
 
 a Simply fibrous, and with snort fibres. 
 
 b. Fibrous radiated. 
 
 c. Very fine fibrous and silky. 
 
 F. The texture so fine that it loses its character, 
 and passes into argillite. 
 
 The above are sometimes imperfectly, or not at 
 all fissile, and then form what is usually named 
 hornblende rock. 
 
 
296 
 
 Second Division. 
 Compound: of two ingredients. 
 
 A. A laminar alternation of hornblende and 
 felspar 
 
 a. Continuous platy and schistose, easily 
 fissile. 
 
 b. The same, but not at all fissile. 
 
 c. Granularly laminar, and imperfectly schis- 
 tose. 
 
 B. The hornblende scaly or fibrous, and the 
 felspar arenaceous ; not in distinct laminae. 
 
 C. A granular uniform mixture of the same in- 
 gredients. 
 
 a. Scaly, imperfectly fissile. 
 
 b. Uniformly arenaceous and mixed : fissile. 
 
 c. Mottled, the hornblende being condensed 
 in patches and spots. 
 
 d. Dull : the ingredients being minutely inter- 
 mixed and compacted. 
 
 e. A very compact, distinct intermixture of the 
 two ingredients. Not schistose, nor distinguish- 
 able from the greenstone of the superincumbent or 
 overlying rocks. 
 
 The modifiations of aspect and color are many, 
 arising from the size, and quantity, and color of 
 the grains. These varieties are the primitive green 
 stone of many. 
 
297 
 
 D. The felspar in excess, the mixture granular. 
 Entirely different from any other hornblende rock. 
 
 E. A minute mixture of hornblende and dark 
 compact felspar; the two ingredients scarcely dis- 
 tinguishable. 
 
 F. Common hornblende schis* with interspersed 
 particles and filamentous veins of bright green 
 compact felspar. 
 
 The two latter varieties are very remarkable. 
 
 G. Hornblende with mica; the former in excess, 
 and the rock fissile. Mixtures of mica schist and 
 hornblende differ from this variety in containing 
 quartz, and are enumerated with mica schist. 
 
 H. Hornblende and chlorite. 
 
 This is mentioned under the head of chlorite 
 
 schist. 
 
 I. Hornblende and actynolite : passing into acty- 
 
 nolite schist. The hornblende is black, and scaly 
 or granular ; the actynolite green and fibrous. 
 
 K. Hornblende and indurated talc : passing in- 
 to serpentine, and mentioned under that head. 
 
 Third Division. 
 Compound : of three or more ingredients. 
 
 A. Hornblende, mica, and felspar. 
 
 B. Hornblende, felspar and quartz. 
 0. Hornblende, actynolite and mica. 
 
298 
 
 D. Hornblende, chlorite and felspar. 
 
 E. Different quaternary mixtures of these ingre- 
 dients. 
 
 Borne of these varieties are also found under the 
 head of gneiss, and some other rocks. The size, 
 proportion, and col r of the several constituents 
 vary and communicate many different aspects to 
 these rocks. 
 
 SYNOPSIS OF ACTYNOLITE SHIST. 
 
 First Division. 
 Simple: of one ingredient. 
 A. Actynolite under various appearances. 
 
 a. Formed of distinct interlaced crystals : 
 of various sizes. 
 
 b. Formed of a confused aggregate of small 
 crystals : sometimes acicular. 
 
 c. The same passing into a granular texture, 
 d Flat foliated. 
 
 e. Fibrous : the fibres straight or undulated, 
 This division exhi bits some shade of green, from 
 dark bottle green to sea green : sometimes, rarely, 
 white. 
 
 Second Dvision. 
 Compound : of two ingredients, 
 
 A. Actynolite and felspar. 
 
 B. m ---hornblende 
 
I 
 
 299 
 
 .;<*... 
 
 C. Actynolite and mica, 
 
 D. talc. 
 
 E. chlorite. 
 
 The last is mentioned also under chlorite schist* 
 
 Third Division. 
 Compound : of three or more ingredients. 
 
 A. Artynolite, hornblende, and mica. 
 
 B. Actynolite, hornblede, felspar, and mica. 
 Porphyry, syenite, greenstone, and greywacke 
 
 are included in the synopsis of the superincum- 
 bent or overlying rocks, and mentioned in others- 
 
 SYNOPSIS OF THE OLD RED SAND STONE. 
 
 First Division. 
 Simple : of quartz alone. 
 A. Sandstone of various degrees of hardness. 
 
 a. Fine, arenaceous. 
 
 b. Gravelly. 
 
 c. Compact, splintery, scarcely arenaceous. 
 The last variety only to be distinguished from 
 
 quartz rock by its position. The members of this 
 division are rare. 
 
 Second Division. 
 
 Compound : of two or more ingredients. 
 A. Quartz sand, mixed with clay. Argillaceous 
 sandstone. 
 
a. Gravelly. 
 
 b. Fine arenaceous. 
 
 c. Very fine, the particles of quartz invisible. 
 This last passes into shale and argillaceous iron 
 
 stone. 
 
 B. Quartz sand, mixed with sand or particles of 
 felspar. 
 
 a. Gravelly. 
 
 b. Arenaceous. 
 
 C. Quartz sand with carbonate of lime : calca- 
 reous; sandstone. 
 
 a. Gravelly. 
 
 b. Arenaceous : generally white. 
 
 D. Quartz sand with carbonate of lime and clay : 
 argillo-calcareous sandstone. 
 
 a. Gravelly. 
 
 b. Arenaceous. 
 
 These derive their color from the clay : when 
 the quartz is fine and in small quantity, they pass 
 into calcareous shale or marie slate. 
 
 E. Quartz sand with mica, and, sometimes, clay : 
 of different degrees of fineness. 
 
 a. The mica, scattered throughout : massive. 
 
 b. The mica disposed in a parallel manner, 
 often in separate laminae : schistose, and more or 
 less fissile. Schistose sandstone. 
 
 F. Quartz sand with indurated or schistose 
 clay. 
 
+ 
 
 301 
 
 This comes under the head of argillite (gray- 
 wack) where it is also mentioned. 
 
 G. Quartz sand, with sand from the disintegra- 
 tion of trap rocks. 
 
 .- 
 
 Third Division. 
 
 Containing fragments of the previous rocks : of a 
 conglomerate structure. Red sand stone conglo- 
 merate, or breccia. 
 
 A. The basis consisting of either of the preced- 
 ing fine varieties, except F. and G, 2d Div : and 
 containing fragments of quartz only. 
 
 B. Similar basis, with fragments of one, or of 
 all the preceding rocks, except argillite, with 
 quartz also. 
 
 C. The same, including F. 2d Div. with frag- 
 ments of argiJlite. 
 
 D. The base G. 2d Div. with fragments of the 
 traps. 
 
 E. The same basis as var. A. containing frag- 
 ments of sandstone, with or without fragments of 
 preceding rocks. 
 
 SYNOPSIS OF COAL. 
 Simple : Carbon nearly pure. 
 A. Burning with difficulty and without flame : 
 
 anthracite, when perfect. 
 40 
 
302 
 
 This modification of carbon contains so little 
 hydrogen as to afford neither naptha nor petroleum 
 on distillation : of course it yields neither flame 
 nor smoke. 
 
 a. Massive ; with a conchoidal shining frac- 
 ture; of an aspect nearly metallic : is found among 
 primary rocks : passes into plumbago. 
 
 b. Friable, pulverulent, or scaly. Rare. 
 
 c. Laminar : blind coal, stone coal, Kilkenny 
 coal. 
 
 This and the preceding varieties are found m 
 primary strata ; and sometimes in the secondary, 
 The last passes into common coal. 
 
 d. Columnar, or prismatic. Found in the 
 vicinity of trap rocks, and passes into plumbago, 
 
 Second Division. 
 Compound : Carbon and bitumen. 
 
 A. Flaming, and burning easily, with smoke, 
 Common coal; occurs massive and slaty united. 
 Several varieties, according to the quantity of bi- 
 tumen it yields. They pass into bituminous shale 
 and are invariable secondary. 
 
 B. Very inflammable : leaving little coak; massive 
 or imperfectly laminar : large conchoidal fracture ; 
 more or less bright, sometimes dull. Canriel coal, 
 occurs with the secondary coal and is sometimes 
 cut, like jet. 
 
303 
 
 C. Coak, Ashes, and smut : rare and partial mo- 
 difications, occurring with the trap rocks. 
 
 Third Division. 
 Lignite : retaining marks of vegetable origin. 
 
 A. Jet, or pitch coal, black amber ; hard and 
 compact : pitchy lustre, takes a good polish ; oc- 
 casionally shows the ligneous fibres. Used as fuel. 
 In Aude, in France, 1200 persons are engaged in 
 making ornaments of it. 
 
 B. Fibrous brown coal ; bituminized wood : 
 Bovey coal. The ligneous fibre very distinct; burns 
 with a clear flame. 
 
 The suturbrand of Iceland belongs to this varie- 
 
 *y. 
 
 C. Earth coal, or earthy brown coal ; pulveru- 
 lent, retaining the texture of wood, though com- 
 pact : burns easily. Known also as Colonge earth 
 or umber. 
 
 D. Moor coal; friable: nearly the same as 
 brown coal, into which it passes. It breaks on 
 exposure to air. 
 
 All the preceding varieties occur in the newer 
 formations : mostly in the tertiary and alluvial, 
 occupying extensive tracts, in strata of various 
 thicknesses. Not much used as fuel. 
 
 
304 
 
 E. Basaltic coal : basaltic wood retaining the 
 texture of wood and passing into true coal. Found 
 in trap rocks. 
 
 SYNOPSIS OF PEAT. 
 
 Although peat does not properly come under the 
 head of rocks, I do not see a more appropriate 
 place for its Synopsis than the present. It has 
 been spoken of before, and the following are the 
 varieties. 
 
 A. Loose or powdery, and often intermixed 
 with clay or sand : mountain and heath peat. 
 
 B. Spongy, imperfect, and containing a large 
 proportion of the roots and fragments of undecom- 
 posed vegetables. 
 
 C. Compact, but still retaining numerous frag- 
 ments of vegetables, and passing into the former. 
 The most ordinary variety used for fuel. 
 
 D. Highly compact, with a total loss of vegeta- 
 ble texture. Heavier than the last, and burns 
 nearly like coal, with a considerable flame. More 
 rare than the former. 
 
 The varieties B. and C. are always in the same 
 deposit, and frequently D, the spoiigy kind being 
 above and becoming more compact below, ex- 
 hibiting the progress of vegetable decomposition or 
 the perfection of peat When wet in their natural 
 
 
305 
 
 position all varieties are soft, and harden by dry- 
 ing. 
 
 E. Compact generally flaky wh^n dry, and con- 
 taining fragments, roots, and trucks oi irees. For- 
 est peat. 
 
 F. When wet, a mixture of water and fine pow- 
 der of peat : on drying, very compact. Traiibport- 
 ed peat; forming fluid bogs. 
 
 As long as vegetaton is kept up, the peat is re- 
 newed after removal : but the process ceases when 
 the vegetating surface is removed, unless it is re- 
 newed by nature or artificial means ; except in 
 transported peat. 
 
 SYNOPSIS OF SHALE. 
 
 First Division. 
 Simple. 
 A. Common Shale. 
 
 a. Hard, and often not distinguishable from 
 argillite and graywack : occurs mostly with old 
 red stone. 
 
 b. Fragile, and less laminar than the preced- 
 ing. 
 
 c. Tender and Scaly. 
 
 d. Passing into clay. 
 
 e. Granular concretionary. 
 /. Spheroidal concretionary. 
 
 
306 
 
 The colors of these are grey; when they change 
 into red or yellowish, it passes into 
 B Ferriferous shale. 
 
 a. Laminar, simple, pink, red, purple, brown, 
 obscure blue, yellow, or variously mottled. 
 
 6 Laminar and short columnar; surfaces 
 singularly channelled on the margin. Columnar 
 ironstone. 
 
 c. Containing red oxide of iron in excess, and 
 passing into common iron stone. 
 
 C. Adhesive slate. 
 
 D. Polishing slate : lighter than water. 
 
 Second Division. 
 Compound. 
 
 A. Argillo-bituminous. 
 
 a. Slightly impregnated with inflammable 
 matter. 
 
 b. So slightly impregnated with bitumen as to 
 be combustible. Black and brown. Kimmeridge 
 coal, accompanies true coal. 
 
 B. Argillo-calcarcous; containing so much car- 
 bonate of lime as to effervesce with acids. 
 
 C. Argillo-micaceous; containing a consider- 
 able portion of mica. 
 
 D. Arenaceo-micaceous ; in which sand enter 
 in quantities. 
 
 
 
307 
 
 E. Quartzose : passing into the flagging sand- 
 stone. 
 
 F. With rounded fragments of trap and other 
 rocks imbedded. 
 
 G. Alum slate aluminous schist : affording an 
 aluminous saline efflorescence on exposure to air, 
 particularly if accompanied by heat and moisture. 
 
 SYNOPSIS OF GYPSUM. 
 
 A. Granular. 
 
 a. Tender. 
 
 b. Compact alabaster of artists. 
 
 B. Fibrous : sometimes dull, often highly splen- 
 dent. 
 
 C. Platy, on the large scale, or approaching to 
 large granular. 
 
 SYNOPIS OF SECONDARY LIMESTONE. 
 
 First Division. 
 
 Simple, or nearly so ; formed of carbonate of 
 lime with little or no intermixture of other earths. 
 Effervesces readily and burns t lime which is easi- 
 ly slackened. 
 
 A. Crystaline : more or less perfect, 
 
 a. Granular. 
 
 b. Granular splintery. 
 
 B. Compact, with a smooth fracture, more, or 
 less glossy. 
 
308 
 
 a. Flat, splintery. 
 
 b. Splintery, and small conchoidal. 
 
 C. Thin laminar, scarcely schistose. 
 
 D. Fibrous, or prismatic. 
 
 a. Fibrous more or less minute, the fibres 
 simple, parallel, and coalescing, sometimes slight- 
 ly undulated. The lustre occasionally silky, and 
 the color white ; forming satin spar. 
 
 b. Fibrous, the fibres ramifying : coalescing ? 
 and with a pseudo-organic structure. 
 
 c. Prismatic, parallel or radiating : the prisms 
 separable, more or loss easily: sometimes striated, 
 and with an obscure appearance of joints : madre- 
 porite. 
 
 E. Concretionary spheroidal. Peastone, roe- 
 stone, and oolite. 
 
 a. With large spherules, sometimes compress- 
 ing each other. 
 
 b. With moderate sized spherules, roestone . 
 
 c. With minute spherules, varying much in 
 size, and sometimes distinct : oolites. 
 
 d. The spherules intermixed with irregular 
 fragments : the Purbeck stone. 
 
 F. Fragile, or easily sectile. 
 
 a. With a smooth somewhat glossy fracture : 
 indurated chalk. 
 
 
* ft - 
 
 309 
 
 b. With an earthy fracture; compact, but sgft : 
 common chalk. 
 
 c. Containing clay : grey chalk. 
 
 (/. Earthy, incompact: chalk marie. 
 All these varieties become occasionally impure, 
 and pass into those of the next division. The most 
 usual colors are white, pale grey, dove, dark grey ; 
 red of different hues, greyish brown, dark brown, 
 black. 
 
 Second Division. 
 
 Compound : containing a considerable proportion 
 of other substances. The nature of the mixture 
 ascertained by chemical analysis, but afterwards 
 recognized by external characters. 
 
 A. Calcareous carbonat, with magnesia, chief- 
 ly. Magnesian limestone. 
 
 a. Massive. 
 
 b. Laminar, and flexible when moist. 
 
 B. Calcareous carbonat, with a large propor- 
 tion of clay intermixed, and some silica. Lias 
 limestone. 
 
 a. Massive : sometimes in laminse divided so 
 minutely by clay or shale, as to seem schistose. 
 
 Some of them form a slag by great heat : will not 
 burn so as to slack : some varieties, when sudden 
 4! 
 
::*# 
 
 310 
 
 ly wetted, harden like tarras cement, and may be 
 used for lythographic purposes. 
 
 b. Concretionary small spheroidal; botryoidaL 
 
 c. Concretionary : large spheroidal, general- 
 ly oblate, and sometimes attached in pairs by a 
 cylindrical bar. 
 
 C. Calcareous carbonat with a considerable 
 proportion of oxide or rust of iron, as well as of 
 clay and silica. Spheroidal, flattened. Often di- 
 vided internally into prisms by calcareous spar; 
 Septaria : this produces water cement like some of 
 the above. 
 
 D. Calcareous carbonat with considerable pro- 
 portions of clay, silica, and oxides of iron. Oc- 
 curs with the old red sand stone. 
 
 a. Imperfectly granular, shining. 
 
 b. Earthy. 
 
 c. Smooth, the fracture splintery, or ap- 
 proaching the conchoidal. This becomes so sur- 
 charged with other earths as to pass into calcare- 
 ous shale, or marie slate. 
 
 E. Carbonate of lime, more or less pure, and 
 intermixed with bitumen. Bituminous limestone. 
 
 F. Carbonate of lime, intermixed with a large 
 proportion ot silica chiefly. It effervesces with great 
 difficulty, unless in powder : forms a slag in the 
 fire : passes into calcareous sandstone. When 
 
311 
 
 near to trap is often highly indurated, assuming the 
 character of chert. 
 
 Third Division. 
 
 Compound : containing some visible ingredient 
 intermixed. 
 
 A Limestone containing mica. 
 
 B. Limestone containing mica and sand. 
 
 These occur with mica or micaceo-arenaceous 
 shale. 
 
 Fourth Division. 
 
 Containing fragments of limestone, or of quartz, 
 or of diffe re it compound rocks. Conglomerated. 
 
 A. Containing fragments of previous limestone. 
 
 B. Containing fragments or pebbles of quartz. 
 
 C. Containing chert or agate in fragments. 
 
 D. Containing fragments ofargillite. 
 
 There are other divisions of limestone, often 
 well marked ; sometimes arising from actual change 
 ofcharacter, from the presence of fossil contents, or 
 from color : mostly however these names are local 
 or geographical : the latter is perhaps the safest, 
 as it can always be referred to and known. 
 
 SYNOPSIS OF SAND STONES. (SUPERIOR.) 
 The term superior sandstones is here used 
 
IP* 
 
 312 
 
 as the Divisions of these sandstones are different 
 from, and above the old red sandstone. 
 
 First Division. 
 Simple : of quartz alone. 
 
 A. An aggregate of grains of quartz, more or 
 less condensed, and varying in hardness. 
 
 a. Of a large grain; gravelly. 
 
 b. Fine, arenaceous. 
 
 The brillancy of these varieties, which are al- 
 most necessarily white, varies according to the 
 quality of the quartz from w r hich they are formed. 
 When highly indurated, their position alone distin- 
 guishes them from quartz rock. In the vicinity of 
 trap, they are said to be indurated occasionally 
 to the state of common quartz. 
 
 Second Division. 
 Compound : of two or more ingredients, 
 
 A. Quartz-sand and carbonate of lime. 
 
 a. Large grained, gravelly. 
 
 b. Fine, arenaceous. 
 These are generally white. 
 
 B. Quartz sand with clay. 
 Subdivisions a. and b. as the preceding. 
 
 The colors vary : white, ocre yellow of differ- 
 ent hues, or red, or grey, or greenish, or black : 
 
313 
 
 occasionally mottled or striped. The red varie- 
 ties, and sometimes even the white and grey are 
 distinguishable from the old red sand stone, only 
 by their geological position, and this it is sometimes 
 impossible to ascertain. 
 
 C. Quartz sand with schistose clay. 
 
 The clay is more or less interlaminated and the 
 rock passes into shale. 
 
 D. Quartz sand with clay and carbonate of lime. 
 Subdivisions a. and 6. similar to var. A. and B.. 
 
 E. Argillaceous or calcareo-argillaceous sand- 
 stone mixed with bitumen. 
 
 This sometimes passes into bituminous shale. 
 
 F. Quartz sand with clay and mica, or with clay, 
 carbonate of lime, mica and red oxide of iron. 
 
 The red marie, or new red sand stone of Eng- 
 gland, is of this kind. 
 
 G. Quartz sand with carbonate of lime, mica 
 and green earth, called in England, Kentish rag. 
 
 H. Sandstone of various qualities containing a 
 large portion of rust of iron, which often forms the 
 cement of the other ingredients : ferruginous sand- 
 stone. 
 
 The varieties of this division, like those of 
 
 the preceding, when in comact with trap, are said 
 to pass into jasper or chert. They sometimes con- 
 tain pyrites, carbonate of copper, oxide of cobalt, 
 and oxydulous iron. 
 

 314 
 
 Third Division. 
 Conglomerates. 
 
 -TVJ?) F 
 
 A. Sandstone containing fragments of quartz. 
 
 B. nodules of trap. 
 
 C fragments of previous 
 
 sandstones. 
 
 D. Sandstone containing fragments of schistose 
 clay o* shale, or of limestone, or of both. 
 
 E. Sandstone containing flints. English pud- 
 dingstone. This is occasionally of a loose arena- 
 ceous texture ; or is highly indurated. Doubtful 
 if it is not alluvial. 
 
 SYNOPSIS OF CLAY 
 
 The clay and the marie and sand mentioned in 
 the following synopsis belong mostly to the Tertia- 
 ry formations. 
 
 A. Ferruginous clay : scarcely ever plastic, red 
 or yellow. 
 
 B. Fuller's earth: dull green or grey: semi- 
 transparent, and crumbling when in water. Oc- 
 curs in the upper sandstones, in the limestones and 
 new red marie, 
 
 C. Schistose clay : white or grey : scarcely 
 ever plastic, until after exposure to air, when it 
 crumbles. Pipe clay, often above the chalk. 
 

 D. Indurated, generally in irregular nodules ; 
 very refractory in the fire. Stourbridge clay. 
 
 E. Plastic clay, potter's clay, of various colours 
 and properties. Very similar to var. C. New Jersey 
 clay. 
 
 F. Blue clay : London clay : plastic in various 
 degrees. 
 
 There are other varieties of clays, passing into 
 different substances besides lithomarge* tripo- 
 li, &c. 
 
 SYNOPSIS OF MARLE. 
 
 A. Simple, or earthy: consisting principally of 
 calcareous matter. 
 
 a. Massive, more or less compact. 
 
 b. Schistose marie slate. 
 
 c. Powdery, or imperfectly plastic, with few 
 or no fragments of shells : often much mixed w ith 
 sand and clay. 
 
 d. A congeries of shells and fragments of 
 shells, more or less pure Shell-marie of agricul- 
 turalists. New Jersey. &c. Some of the varie- 
 ties, a & b. become plaotic on exposure to air. 
 
 B. Bituminous marie : more or less distinctly 
 schistose. There is some obscurity in this sub- 
 stance, since it is known to contain fish, and it is 
 
316 
 
 said to be frund in different parts of Europe, in 
 connection with primary lime-stone. 
 
 SYNOPSIS OF SAND. 
 
 A. Quartz alone. 
 
 B. and clay. 
 
 C. and limestone, or limestone and clay. 
 
 D. and mica. 
 
 E. and highly ferruginous clay, or 
 
 ochre, with other less important substances : fer- 
 ruginous or iron sand. 
 
 F. Quartz, limestone, mica, and green earth, 
 Green sand. 
 
 SYNOPSIS OF ALLUVIA. 
 
 First Division. 
 Loose. 
 
 A. Single stones, more or less accumulated in 
 particular places, generally bearing marks of waste 
 in a greater or less degree, and commonly consist- 
 ing of the older rocks. Granite boulders are the 
 most conspicuous and frequent : but there are 
 boulders of other rocks: single in the interior of 
 countries, and forming heaps on sea shores. 
 
 B. Stones of various sizes mixed with sand or 
 clay, or both. 
 
 
317 
 
 a. The produce of one rock: alluvia formed in 
 
 bltU. 
 
 b. Pebbles of flint with sand and clay. It is 
 questionable whether the pebbles were originally 
 rounded, or if they have been worn by the action 
 of water. 
 
 c. Rounded fragments of various rocks, inter- 
 mixed with clay or sand. Alluvia of rivers and 
 Diluvian alluvia. 
 
 d. Fragments slightly rounded, or angular, 
 with clay and sand. Alluvia of descent. 
 
 C. Of fine materials, consisting of sand and clay, 
 more or less compacted. 
 
 a. Clay. 
 
 This embraces many varieties, containing differ- 
 ent proportions ofsilex and alumine, and occasion- 
 ally magnesia and lime. The decomposition of 
 granite furnishes an excellent porcelain clay : 
 and gneiss yields by the same process a white clay 
 of some value. 
 
 b. Clay with a large proportion of sand : loam 
 of agriculturalists. 
 
 c. Compact sand, always with a mixture of 
 fine clay sufficient to consolidate it : found in the 
 alluvia of rivers and lakes, and on the sea shore. 
 
 d. Clay containing inflammable or carbonace- 
 ous matter arising from the decomposition of ani- 
 
 42 
 
318 
 
 mals and vegetables : Mud. Found in estuaries, 
 and in the deposits of sluggish streams. 
 
 D. Of fine materials, and loose or incompact. 
 
 a. Quartz sand. 
 
 On sea shores, and also removed by winds, so 
 as to form sand hills and other similar inland de- 
 posits, which are consolidated by the growth of 
 vegetables. Long Island, New Jersey, and Virgi- 
 nia sand hills. 
 
 b. Of calcareous sand ; commonly from the 
 decomposition of sea shells, and found under simi- 
 lar circumstances. , 
 
 E. Sand of various constitution, found in partial 
 deposits in different places, and commonly, if not 
 always, arising from the decomposition oi rocks, 
 
 a. Quartz and argillite. 
 
 b. felspar. 
 
 Cf the sand of trap rocks. 
 
 d. Mica : or mica with clay, or felspar, or 
 quartz or hornblende, or all of these. From gra- 
 nite and gneiss. 
 
 F. mixtures of various kinds, forming the soil of 
 agriculturalists. Some of these are transported 
 materials, others are produced by the decomposi- 
 tion of rocks in situ. Those arising from the de- 
 composition in situ of the trap rocks, of argillace- 
 
319 
 
 ous limestone and of argillite, are the most fertile 
 and valuable. ^ 
 
 G. Vegetable soil, or mould, consisting of a 
 mixture of any of the preceding with a hydro-car- 
 bonaceous compound, analogous to peat, resulting 
 from the decomposition of vegetables. This sub- 
 stance confers fertility on the compound in propor- 
 tion to its quantity, other circumstances being 
 equal. 
 
 Second Division. 
 Solid. 
 Simple. 
 
 A. Compacted sand of quartz, or recent sand- 
 stones : sometimes found in the river alluvia: ten- 
 der. 
 
 B. Compacted shell sand : recent oolite. 
 
 Frequent in the Bahama Islands and similar si- 
 tuations. The grains often perfectly round, and 
 serving to elucidate the origin of the older lime- 
 stones of this nature. 
 
 C. Compact limestone, deposited from the wat- 
 ers of existing rivers and lakes in large masses. 
 
 The travertino of Rome, and the stalagmitic 
 rocks, similar to that of Gibraltar come under this 
 head. 
 
 Compound, 
 
320 
 
 A. Substances of various kinds and sizes cement- 
 ed by carbonate of lime. 
 
 a. Quartz sand cemented in this manner. 
 On sea shores and in river alluvia. 
 
 b. Fragments of many kinds cemented in the 
 same way into a solid mass. 
 
 On sea shores. 
 
 B. Various substances cemented by rust of iron, 
 
 a. Quartz, sand, and gravel : recent ferrugin- 
 ous sand stone. Similar to the iron sand in its 
 most solid state. 
 
 b. Flint, gravel, clay, and sand, cemented in 
 the same way. 
 
 Some trap rocks seem to undergo a similar pro- 
 cess after disintegration ; forming a recent tufa. 
 
 SYNOPSIS OF THE OVERLYING OR SU- 
 PERINCUMBENT ROCKS. 
 
 First Division. 
 
 Simple : or apparently so. 
 
 A. Wacke, of the German school. Resembles 
 indurated clay, with an even and smooth earthy, 
 or an uneven somewhat granular fracture, and a 
 shining streak. 
 
 a. Compact. 
 
 b. Cellular : but generally in that case, partly 
 
321 
 
 amygdaloidal, and appertaining to another division. 
 
 B. Indurated clay : more or less hard, with an 
 earthy and dull fracture. 
 
 a. compact. 
 
 This is different from the ferruginous clays found 
 often with the trap rocks, which pass into jasper. 
 
 b. Cellular. 
 
 Like var, A. b. it is rarely cellular in large mass- 
 es, without also containing amygdaloidal nodules, 
 when it passes to another division. The colors of 
 this variety are usually ash, or grey, of different 
 hues, or modifications of red, or brown, or pur- 
 plish black. 
 
 C. Claystone. The fracture is dull and earthy, 
 and may be smooth and even, or rough and some- 
 what granular, or imperfectly splintery, or con- 
 choidal. It differs from the preceding substances 
 in hardness; but there are no definite distinctions 
 in this case. Its structure is never schistose, and 
 this, independently of its geological differences, 
 distinguishes it from argillite. 
 
 a Massive, irregular. 
 
 6. Prismatic, or columnar. 
 
 c. Laminar. 
 
 d. Cellular. 
 
 The laminar structure is seldom seen, except on 
 the surface, and after exposure to weather. It is 
 
322 
 
 sometimes combined with the prismatic structure, 
 but cannot easily be confounded with the schis- 
 tose argil lite. The colors of clay stone are pale 
 greyish, or muddy white, or ochre yellow, of vari- 
 ous degrees, or flesh color, or purplish, or differ- 
 ent tints of grey, from smoke color to dark lead 
 grey, nearly black. 
 
 This variety is most common in mountain mass- 
 es; it is found but rarely in veins. 
 
 D. Indurated clay stone. Harder than the for- 
 mer, and distinguished by the superior lustre and 
 acuteness of the fractures, which are also granu- 
 lar, splintery, or conchoidal It is separated, not 
 so much on account of its mineralogical differ- 
 ences, as from its geological importance. It forms 
 the most extensive and the most common rock of 
 this class in the nonh of Great Britain. 
 
 a. Massive, irregular. 
 
 b. Prismatic, or columnar. 
 
 c. Laminar, under the same circumstances 
 as C. c. 
 
 * The dark varieties, particularly when prismatic 
 or in veins, are often called basalt, and may be con- 
 sidered as forming varieties under this popular 
 and indefinite term. It is found in veins and in 
 mountain masses ; frequently in the former, and it 
 thus occurs sometimes with the seemingly ancierif 
 
323 
 
 porphyries that traverse granite. The colors arc 
 the same as those of the preceeding variety. Some 
 specimens of brilliant colors are called jasper, to 
 which they approximate. 
 
 E. Clinkstone. This is still harder than the 
 preceeding variety, and is not scratched by the 
 knife The fracture too is more perfectly splin- 
 tery and conchoidal : occasionally somewhat 
 granular; the lustre more considerable, and the 
 fragments slightly translucent on the edges, it is 
 sonorous, but not more so than many other mem- 
 bers of the trap family. Its mineral characters 
 have been mentioned. 
 
 a. Massive. 
 
 b. Columnar, or prismatic. 
 
 c. Laminar 
 
 The dark varieties of b. have, like the former, 
 been enumerated among the basalts The same 
 remarks as in the two preceeding cases, maybe 
 made on var. c. 
 
 The colors and geological positions are similar 
 also. The surface, when weathered, becomes 
 arenaceous, and has been confounded with sand- 
 stone. 
 
 r \ he substances C. D. and E. pass insensibly in- 
 to each other, as do other rocks. 
 
 F. Compact felspar, including hornstone. Its 
 

 324 
 
 superior hardness, compactness and lustre distin- 
 guish it from the preceeding, to which it is allied, 
 The edges are more decidedly translucent. 
 a. Imperfectly laminar. 
 
 6. Massive, with a smooth, splintery, and con- 
 choid al fracture. 
 
 c. Crystalline-granular. 
 
 The var. a. and b. occur simple, in veins, but are 
 frequently slightly porphyritic in some places: 
 never as mountain masses. 
 
 Var. c. assumes different aspects according to 
 its fineness. The colors are usually those of the 
 preceding varieties : but sometimes, grains of two 
 colors (as white and dark lead- blue, or greyish 
 green and blackish green) occur, and it has then 
 been mistaken for greenstone. 
 
 Fawn and cinnamon colors are seen in var. "a. 
 b. also brick red, muddy white, and of every tint 
 from grey to black. From clinkstone to compact 
 felspar, there seems to be a gradation similar to 
 that between C. D. E. Simple compact felspar 
 passes very generally into porphyry. The varie- 
 ties C. D E F. in the same way, become por- 
 phyritic or amygdaloidal. 
 
 The preceding rocks, particularly C. D, E. lose 
 their natural characters for some depth beneath 
 the surface; retaining their solidity, but acquiring 
 
325 
 
 an arenaceous aspect, and changing color, so that 
 the dark indurated claystone or clinkstone as- 
 sumes the* appearance of indurated clay, var. B. 
 
 G. Hornblende compacted into a solid mass, 
 and apparently consisting of minute crystalline par- 
 ticles. The fracture is coarse grained, and is, fur- 
 ther, uneven, splintery, or conchoidal. It varies in 
 lustre sometimes glistening. It is one variety of 
 basalt : the only basalt of some authors. 
 
 Basalt by analysis, yields soda, but hornblende 
 does not. 
 
 a. Massive, irregular. 
 
 b. Laminar. 
 
 c. Columnar or prismatic. 
 
 This basalt is found in veins and masses in the 
 former, laminar. The var. b. c. are sometimes 
 joined, as in clay stones, the laminae being either 
 parallel or at right angles to the axis of the prism. 
 
 Basaltic columns are sometimes jointed, as be- 
 fore mentioned : but that structure is not confined to 
 basalt ; nor is it characteristic. 
 
 Second Division. 
 
 Compound : formed of two substances. 
 Granitiform mixtures. 
 
 A. Hornblende and compact felspar. 
 a. In nearly equal proportions, or the horn- 
 43 
 
blende predominant, and the two minerals distinct- 
 ly visible. Greenstone. 
 
 It occurs in veins and in mountain masses ; and 
 like some of the preceding is columnar, as well as 
 laminar. The hornblende is black or dark green 
 and sometimes crystallised. The felspar is white, 
 yellowish, red of different hues, pale green, or grey 
 from light to nearly black. The relative propor- 
 tion, and size, and color, of the particles give a 
 variety of aspects. Rocks not distinguishable from 
 the dark varieties occur, togetner with granite, as 
 already mentioned. 
 
 The felspar is sometimes accumulated in spots, 
 in the mixture, presenting a porphyritic aspect, 
 and forming pseudo-porphyries. 
 
 When the felspar is red, the compound is oft- 
 en mistaken for granite. 
 
 b. Compact felspar predominant. Syenite. 
 It occurs mostly in mountain masses, rarely in 
 veins. It is occasionally partially laminar, and 
 columnar. Like other members of this family, it 
 does not preserve the same appearance for any con- 
 siderable extent varying with the proportions of 
 the constituents It is sometimes even simple, to 
 the exclusion of hornblende. This is one of the 
 Syenites, of this fenady. 
 
327 
 
 c. The mixture imperceptible, or nearly so ; 
 to the naked eye. In this variety the hornblende 
 is in equal or greater proportion than the felspar, 
 which is usually dark ; hence the compound is 
 dark grey, or greenish black or nearly black. 
 This is sometimes called basalt : presenting the 
 same appearances as some varieties of D. E. and 
 G. First division and like them columnar as well 
 as laminar occasionally. 
 B. Hornblende and common felspar. 
 
 a. In nearly equal proportions. 
 The rocks of this variety are generally called 
 greenstone, although differing in appearance from 
 the varieties of A. into which, however, they pass. 
 Some mineralogists call them syenites; they do 
 pass into them by an increase of felspar. When 
 the felspar is red, they resemble some varieties of 
 granite. 
 
 6. The felspar predominant. 
 This too forma one of the prevailing varieties of 
 Syenite : and is found under precisely the same 
 circumstances as var A. b. Its aspects is more de- 
 cidedly granitic than the variety containing com- 
 pact felspar. When the felspar is dark gray, as is 
 sometimes the case, the compound has been im- 
 properly termed greenstone. 
 C. Compact felspar and quart" 
 
328 
 
 This occurs occasionally in conj action with syen- 
 ite and the simple rocks. Quartz is found in the 
 same way connected with indurated clay andclink- 
 stone. 
 
 D. Common felspar and quartz. 
 
 This compound occurs among syenites and ana- 
 logous rocks. 
 
 E. Hornblende and glassy felspar. 
 
 This is rare, and occupies but small spaces, 
 
 F. Augit and compact felspar. 
 
 a. The augit in equal or superior proportion 
 to the felspar, distinctly intermixed. Augit rock. 
 
 This occurs in veins and extensive masses ; and 
 is occasionally laminar and columnar. Its appear- 
 ance varies according to the relative proportion, 
 size, and color of the augit. 
 
 b. In such a state of intermixture that the 
 parts are nearly or altogether invisible. 
 
 The colors of this compound are black, or with 
 some shade of green. It has been confounded 
 with some basaltshaving the same fracture gen- 
 eral appearance. 
 
 c. The felspar in excess, and both minerals 
 distinct. 
 
 This compound resembles the analogous varie- 
 ties of syenite, into which hornblende enters. Like 
 the common varieties of Syenite, it presents vari- 
 ous aspects. 
 
329 
 
 (jr. Augit with glassy felspar. 
 
 Perhaps augit forms other compounds : it occa- 
 sionally is an ingredient in a ternary compound 
 with hornblende, 
 
 H. Hjperstene with compact felspar. 
 
 I. common felspar. 
 
 K. glassy felspar, and some- 
 times with the addition of common felspar. Hyper- 
 stene rock. 
 
 These three varieties have been insisted on by 
 Dr. Macculloch. They occur in beds, in moun- 
 tain masses : never in veins, nor columnar. Oc- 
 casionally they exfoliate like granite, and some- 
 times possess a foliated structure like gneiss, 
 from the parallel position of the hyperstene. The 
 structure is generally granitic, and varies accord- 
 ing to the size and proportion of the ingredients. 
 Sometimes it resembles granite, and at others 
 greenstone: and with an addition of imbedded 
 crystals of felspar, it occasionally resembles grap- 
 hic granite, W hen very fine, it approaches to ba- 
 salt. 
 
 Compound : of two substances ; one of which is more 
 or less distinctly crystallised and embedded in a simple 
 base of the other. Includes some porphyries. 
 
330 
 
 A. Claystone, common or indurated, with imbed- 
 ded scales of mica, sometimes regularly crystal- 
 lised. 
 
 This is found in veins and in masses ; but is 
 rare. 
 
 B. Grains, or imperfect crystals of quartz im- 
 bedded in a simple base. 
 
 a. Base of claystone. 
 
 b. indurated claystone, 
 
 c. clinkstone. 
 
 < compact felspar. 
 
 The colors vary with that of the base. They 
 usually are found together with the simple rocks 
 forming the bases. 
 
 C. Crystals of felspar imbedded in a simple, 
 or apparently simple base. Porphyry. 
 
 Bases a. b. c. d. as the preceding. 
 
 These are the most common simple porphyries. 
 The crystals may be common or glassy felspar, or 
 both. The felspar is sometimes opake and dull, 
 as if beginning to decompose; at other times it is 
 powdery. And again the place may be partially 
 filled with an ochry powder, the mass appearing 
 carious. 
 
 The colors of course are liable to all the vari- 
 eties of the simple rocks forming the bases; other 
 
331 
 
 varieties arise from the color of the crystals, or 
 their mode of disposition. The cross crystals are 
 the most remarkable. By the gradual exclusion 
 of the crystals, the porphyries pass into simple 
 rocks. They occur in veins and in mountain 
 masses. 
 
 The var. a. b. c. are found mostly among the 
 later secondary rocks, but occasionally even with 
 granite, like their bases, with var d. This last is 
 most seen with rocks of older date. They are all 
 occasionally laminar, and columnar, like some 
 syenites. 
 
 6. Base of basalt. Basaltic porphyry. 
 
 The basalt is of any of those substances usual- 
 ly called so and the crystals frequently glassy. 
 
 Third Division. 
 
 Compounds of three or more ingredients. 
 First Sub-division. 
 
 Granitiform mixtures* 
 
 A. Felspar, hornblende, and quartz Syenite. 
 
 This alone is the compound which accords with 
 the common definition of Syenite. Although the 
 definition is upheld, it is constantly violated in 
 practice. 
 
 The felspar may be compact or common: the 
 former being found among the overlying rocks 
 
332 
 
 only and never, perhaps, among granites, where- 
 as the latter compound is very prevalent with gra- 
 nite, of which it is a variety well known. When 
 found with trap rocks the color of the felspar is 
 often greenish, and the quartz being overlooked, 
 the compound has been termed greenstone. The 
 aspects and colors of this compound, of course, 
 vary greatly, and depend upon the color, propor- 
 tion and size of the ingredients. 
 
 B. Felspar, hornblende, and mica. 
 
 This is not common : and has been termed mi- 
 caceous greenstone. 
 
 C. Felspar, hornblende, and chlorite. 
 D. and steatite. 
 
 E. Felspar, quartz, hornblende and mica. 
 Thevar. C. D. are rare. Notwithstanding the 
 
 similarity of var. E. to granite, its situation places 
 it among these rocks. It appears to be the com- 
 pound that has been called new granite. 
 
 It is said that no mixture of quartz, mica, and 
 felspar, has occurred among the superincumbent 
 rocks. 
 
 The constituents of these syenites may be erys- 
 talised, as in granite. These varieties are some- 
 times laminar as well as columnar. 
 
 F. Augit, felspar, and mesotype. 
 
333 
 
 G. Augit, felspar, and prehnite. 
 
 H. * calcedony, or quartz. 
 
 I. calcedony, and prehnite, 
 
 or mesotype. 
 
 These are varieties of augit rock. 
 
 K. Augit, felspar, and olivin. 
 
 L. Hornblende, felspar, and epidote. 
 
 These varieties are accidental or limited. 
 
 M. Hornblende, felspar, and prehnite; some- 
 times with the addition of mica. 
 
 The prehnite forms a decided constituent in this 
 rock. 
 
 N. Hornblende, common felspar, compact fel- 
 spar, quartz and steatite, and apparently augit. 
 Found very rarely. 
 
 O. Hornblende, and greenish compact felspar 
 forming the chief part of a mixture in which are 
 intermingled glassy felspar, opake white felspar, 
 augit in prisms, and mica, with pyrites. 
 
 All these complicated varieties can be referred 
 to no other than the superincumbent or overlying 
 rocks. 
 
 Second Sub-Division. 
 
 One species of crystals imbedded in a compound 
 base, or two species of crystals imbedded in a base 
 that is either simple or compound. This includes 
 
 all the remaining porphyries. 
 44 
 
334 
 
 A. Felspar crystals in a base of greenstone. 
 This is the greenstone porphyry, exhibiting dii- 
 
 ierent aspects according to the quality of the base 
 They may be distinguished by a reference to what 
 has been said above. 
 
 B. Felspar crystals in a base of syenite. 
 
 The same remarks apply to this variety, which 
 passes insensibly into porphyritic granite. 
 
 C. The crystals consisting of felspar and quartz. 
 D. mica. 
 
 E. . talc. 
 
 F. epidote. 
 
 Q. pinite. 
 
 H. chlorite. 
 
 I. hornblende. 
 
 In many of these cases, it is difficult to ascertain 
 if the crystals be imbedded, or if it form part of 
 the base : and in such cases a gradation exists be- 
 tween granitiform and porphyrtic mixtures. Often 
 the cavities of porphyries, like amygdaloids, are 
 empty. 
 
 Fourth Division. 
 
 Supra-compounded rocks. 
 
 This division embraces many of those enumerat- 
 ed in the preceding catalogue as bases, in which 
 nodules of several adventitious minerals are im- 
 bedded. Amygdaloids. 
 
Indurated clay B. div. 1st different varieties, is 
 the most frequent base. 
 
 The porphyritic and amygdaloidal structures 
 may be combined, and thus produce many incident- 
 al varieties. The amygdaloids may contain one or 
 more minerals, giving rise to several varieties. 
 
 The size of the nodules, and their quantity di- 
 versify the aspect. The nodules do not always 
 fill the cavity that contains them. Two or more mi- 
 nerals sometimes occur in the same cavity, as agate 
 and calcareous spar. The amygdaloid may have 
 large portions containing empty cavities, others 
 partially and others wholly filled resembling 
 sometimes cellular or scoriform lavas. 
 
 The transition is often imperceptible from simple 
 rocks to amygdaloids. 
 
 From these circumstances the variety of amygd- 
 aloids is great : those containing the calcareous 
 spar and the zeolites are the most abundant. The 
 nature of the imbedded mineral, the characters of 
 the bases, and the many combinations give rise to 
 too many modifications to enumerate them all. 
 The list of minerals contains those usually found, 
 and in the order of their relative frequency : viz. 
 Siliceous Minerals. 
 Calcedony : rariously colored, ^oned, and striped : 
 
 Cacbolopg; and semi opal 
 
 
 

 336 
 
 Hyalite, 
 Heliotrope. 
 
 Brown carnelian : calcedony colofed by chlorite 
 Chert. 
 
 Qjuarz, with different degrees of opacity. 
 Amethyst. 
 
 Zeolitic Minerals. 
 
 Mesotype Prelmite 
 
 Nadelstein Laumonite 
 
 Analcime Ichthyophthalm* 
 
 Stilbite Harmotome. 
 Chabasie 
 
 Calcareous Minerals, 
 
 Carb. of lime Flour spar 
 
 Brown spar Arragonite. 
 
 Schiefer spar. 
 
 Miscellaneous Minerals. 
 
 Sulphat of barytes Steatite 
 
 Sulphatof Strontian Lithomarge 
 
 Olivin Chlorophoeite 
 
 Epidote Conite 
 
 Mica Leucite* 
 Chlorite. 
 
 Metallic Minerals. 
 
 Specular iron Copper 
 
 Pyrites Galena. 
 
 The following minerals sometimes occur in the 
 preceding rocks : and may be considered as adven- 
 titious. 
 
 Apatite Garnet 
 
 Tourmaline Opal 
 
 Abestos Meionite 
 
 Schiller spar Sommite. 
 
 The two last perhaps belong rather to lavas 
 
 than traps. They have all been found in recent 
 greenstones and basalts; 
 
337 , 
 
 Precious epal and chrysoprase occur occasion- 
 ally in certain porphyries. 
 
 The amygdaloids generally occur in large 
 masses: rarely in veins. In both cases, they are 
 occasionally laminar. 
 
 Fifth Division. 
 
 Conglomerates. 
 
 The substance included under this head, is also 
 mentioned under Conglomerate rocks. 
 
 A. Fragments of different trap rocks and of 
 various sizes, angular, and re-united into a solid 
 mass. Trap tuff! 
 
 a. Fine, tuffaceous. 
 
 b. Conglomerated ; coarse. Trap conglome- 
 rates. 
 
 1 hey form beds or masses intermixed with the 
 other varieties. Sometimes they contain portions 
 of carbonised wood, or of foreign rocks and may 
 then be called transported conglomerates. 
 
 SYNOPSIS OF VOLCANIC ROCKS. 
 
 Preliminary remarks. 
 
 Geologists are much divided as to the substan- 
 ces that strictly come under this head. Where vol- 
 canoes have been long extinct, and some of the most 
 decisive characters have been lost, much dispute 
 
338 
 
 has arisen as to the substances that formed part 
 of the mountain previous to the existence of the 
 volcano, and as to those acknowledged to have 
 been the produce of it. The chief difficulty how- 
 ever arises from the trap recks, which are attri- 
 buted by some to aqueous by others to igneous or- 
 igin ; and many of which so closely resemble vol- 
 canic products, that they are thought to be of simi- 
 lar origin. 
 
 The structure is the same as that of the trap 
 family : viz, the prismatic, and lamellar, as well 
 as the cavernous, amygdaloidal and porphy- 
 ritic. 
 
 Respecting the imbedded minerals, much dis- 
 pute has arisen as to whether they are ejected 
 unaltered, whether they are formed in the lava by 
 chemical affinities, or whether they are not pro- 
 duced by infiltration. 
 
 ..;-,/' 
 
 First Division. 
 More or less perfectly vitreous. 
 
 First Sub-division. 
 Solid. 
 A. Obsidian : volcanic glass. 
 
 a. Massive. 
 
 b. With an imperfect laminar structure. 
 
 c. Concretionary ; imperfectly spheroidal OF 
 granular. 
 
339 
 
 rf. Fibrous, loose rare. 
 c. Porphyritic; inclosing felspar. Obsidian- 
 porphyry, 
 
 Black, dark green, pale muddy green, grey and 
 brown are the usual colours. It is sometimes stri- 
 ped. The lustre and opacity vary. In one in- 
 stance it has been found to contain mica. 
 
 Second Sub-division. 
 Cavernous. 
 
 A. Cavernous Obsidian; passes to pumice. 
 
 B. Pumice. 
 
 a. Simply cellular. 
 
 b. Cellular protracted, becoming nearly fi- 
 brous. 
 
 C. Scoria. Formed of a less perfect glass, and 
 passing to porous lava. 
 
 Second division. 
 
 With a base of compact felspar j or supposed to 
 be so. 
 
 A. Simple ; solid, or imperfectly granular. 
 
 B. Porphyritic : pale volcanic porphries. 
 The pale lavas belong to this division. Felspar 
 
 is not necessarily the only imbedded mineral. 
 
 Third Division. 
 
 With a base of basalt, or some analogous sub- 
 stance, simple to the eye. 
 
* 
 
 340 
 
 A. Simple : dark lava, and scoriform lava, 
 
 a. Compact : compact lava. 
 
 b. Porous : cavernous lava, or scoria ; The 
 caverns are often partially filled with substances 
 entering into volcanic amygdaloid^, into which this 
 passes. 
 
 c. Prismatic, or columnar : volcanic basalt of 
 writers. 
 
 d. Concretionary on a smaller scale : spheroi- 
 dal or otherwise, 
 
 B. Compound : containing felspar : porpyries ; 
 other minerals beside felspar may be imbedded. 
 
 C. Compound : containing amygdaloidal no- 
 dules : Volcanic amygdaloid. 
 
 The imbedded nodules are usually calcareous 
 or fluor spar, zeolitic minerals and calcedony. 
 As they are sometimes accompanied by water, they 
 seem to have been produced by infiltration. The 
 colors afe black, brown, grey, &c. depending 
 often on the number and nature of the imbedded 
 minerals. A list of imbedded substances will be 
 seen presently. 
 
 Fourth Division. 
 
 With a base of greenstone, or some analogous 
 compound. Augit seems to have usurped the 
 place of hornblende. 
 
 A. Simple. 
 
341 
 
 B. Porphyritic. 
 
 C. Amygdaloidal. 
 
 This division contains similar varieties with the 
 last. 
 
 Fifth Division. 
 
 With a base of common felspar. 
 
 These are granitic compounds, but distinct from 
 ejected granite. All these lavas present various 
 modifications of external form, arising from the 
 manner in which these have flowed, and similar to 
 those found in the slags of furnaces. ' 
 
 Sixth Division. 
 
 Ejected substances, more or less altered by the 
 fire. 
 
 First Sub-division. 
 Solid : conglomerates. 
 
 A. Conglomerates of various fragments of differ- 
 ent rocks, with mica, augit, and other minerals. 
 
 B. Conglomerates consisting chiefly of clay, and 
 having apparently, been ejected in the state of 
 mud. Tufa. 
 
 a. Coarse tufaceous conglomerates. 
 
 b. Fine and powdered tufa. 
 
 These latter varieties often containing augit., 
 mica, and other imbedded minerals, as well as the 
 
 solid lavas. 
 
 45 
 
342 
 
 Second Sub-division . 
 Loose. 
 
 A. Fragments of various rocks, both primary 
 and secondary, more or less altered by the fire. 
 
 B. Powdery, puzzolana, dust, ashes. 
 
 The following are the chief imbedded miner- 
 als found in these rocks. The amygdaloidal 
 minerals are not added. 
 
 Felspar Melanite 
 
 Pyroxene Idocrase 
 
 Garnet Toumaline 
 
 Hornblende Apatite 
 
 Peridot Zircon 
 
 Mica Ice spar 
 
 Hauyne Pleonaste 
 
 Meioniete Arragonite 
 
 Melilite Sphene 
 
 Tabularspar Oxydulous iron 
 
 Sommite Copper 
 
 Leucite Selenium 
 
 SYNOPSIS OF CONGLOMERATE ROCKS. 
 
 Preliminary remarks* 
 
 Many of the rocks noted under this head, have 
 already been mentioned but for sake of more 
 easy reference are again introduced among the 
 more important varieties. 
 
 These rocks occur among the primary and 
 secondary strata, and are sometimes very limited, 
 at others occupying extensive tracts. They may 
 be divided into general and local. 
 
343 
 
 The former constitute portions of those mixed 
 rocks, whose origin is mechanical, and are formed 
 of large fragments of the same substances, which* 
 when in more minute division compose the finer 
 strata. They must of course contain both simple 
 and compound rocks of older origin than them- 
 selves as for example, the red sand-stones and ar- 
 gillites. The materials are united without any 
 distinct cement of a crystalline nature, particu- 
 larly in the secondary class : and the fragments 
 are more or less rounded. In some instances they 
 seem to be only portions of the finer rocks which 
 they accompany, in others they form extensive 
 strata. 
 
 Local conglomerates are generally confined to 
 the superficies of some simple rock and are 
 most various in lime-stones. Their composition 
 is regulated by that of the adjoining rock. When 
 between different rocks they contain fragments of 
 both generally angular. These remain where their 
 parts were united but, in general conglomerates 
 the constituents have undergone transportation. 
 The one arising from simple fracture and re-union 
 ihe other originating from important and exten- 
 sive revolutions and may be called the consoli- 
 dated alluvia of former ages. 
 
344 
 
 The minerals entering into the local conglome- 
 rates are few, and are most frequently united by 
 distinct cement of fine materials, or of crystalline 
 matter, particularly among calcareous conglome- 
 rates. 
 
 Trap conglomerates are local, and are formed by 
 operations peculiar to those rocks sometimes 
 containing bituminous wood and fossil remains. 
 
 First Division. 
 
 Consisting of fragments of one rock, either im- 
 bedded in a continuous base of the same sub- 
 stance, or re-united chiefly by minuter fragments, 
 or united by veins of carbonate of lime, or of 
 quartz. 
 
 A. Consisting of limestone alone : local. 
 
 a. With angular fragments. 
 
 This occurs among primary and secondary rocks 
 and includes the ornamental breccia-marbles. 
 It is local, confined to some simple limestone. The 
 union is effected by carbonate of lime. 
 
 b. With rounded fragments. 
 
 The materials, which may be primary or secon- 
 dary, have been transported. It does not occur 
 in large strata or masses nor attached to any 
 particular rock? as the preceeding. 
 
345 
 
 B. Consisting of fragments of quartz, or quartz 
 rock alone united in various ways. 
 
 a. With angular fragments. 
 
 Local connected with quartz- rock of course 
 primary. 
 
 b. With rounded, or angular and rounded 
 fragments together. 
 
 One of the varieties of quartz- rock, under which 
 head it is mentioned. 
 
 C. Consisting of fragments of jasper, united by 
 quartz or calcedony : agate local. 
 
 D. Consisting of fragments of gneiss, of various 
 sizes, agglutinated. 
 
 This variety is local attached to gneiss and 
 forms the first bed of primary sandstone, where 
 that rock rests on gneiss : it is necessarily primary. 
 
 E. Consisting of fragments of argillite, re-united 
 by smaller particles or by clay or imbedded in a 
 continuous schist. 
 
 It is primary and local and noticed under the 
 head of Argillite. It may occur as secondary, and 
 transported. 
 
 F. Consisting of chlorite schist formed similar- 
 ly to E : local. 
 
 Accompanies chlorite schist, and is primary. 
 
 G. Fragments of the different trap rocks re-unit- 
 ed by finer particles of the same. 
 
346 
 
 a. With angular fragments. 
 
 Trap tuff, mentioned among the overlying rocks . 
 local. 
 
 b. With rounded and angular fragments both- 
 The materials are transported but this is con- 
 fined to the vicinity of trap rocks and often of 
 partial occurrence. May be either primary or 
 secondary. 
 
 Similar Conglomerates may occur, consisting of 
 the fragments oi mica schist. 
 
 Second Division. 
 
 Consisting of two rocks or substances, united 
 similarly to the varieties of the former division. 
 
 A. Serpentine and limestone ; or calcareous 
 spar : local. It generally occurs between lime- 
 stone and serpentine and is necessarily primary 
 it includes the verde antique. 
 
 B. Fragment, of argillite with limestone. 
 
 a. Argiilite imbedded in limestone. 
 
 b. A confused mass of fragments of both. 
 
 c. Fragments of limestone imbedded in argil- 
 lite. 
 
 These are primary and some of them valuable. 
 
 C. Fragments of limestone imbedded in mica 
 schist : local. 
 
 D. Fragments of granite with mica schist or 
 gneiss : local. 
 
347 
 
 a. The fragments of granite imbedded. 
 
 b. Confused mass of fragments of granite, and 
 of mica schist, or gneiss. 
 
 E. Granite uniting fragments of the same rocks 
 and offering similar modifications. 
 
 Where mica, schist or gneiss approximates to 
 granite the latter often contains so many fragments 
 of those rocks as to seem conglomerate. 
 
 F. Quartz imbedded in limestone : local. 
 
 a. In angular fragments. 
 
 b. In rounded pebbles. 
 
 These are both primary and secondary. 
 
 G. Trap imbedded in limestone, and in the ac r 
 companying shale : local. 
 
 The trap is usually in rounded nodules and ap- 
 parently weathered : occurs in secondary limestone. 
 
 H. An aggregate of fragments of argillite and 
 chlorite schist : local. 
 
 This occurs where the two rocks accompany 
 each other, and is local. 
 
 I. Sandstone with quartz. 
 
 a, The quartz in angular fragments. 
 
 b. The quartz in rounded nodules, or united 
 with angular fragments. 
 
 II. Sandstone and lime united. 
 
 . Fragments of sandstone imbedded in lime- 
 atone. 
 
6. Fragments of limestone imbedded in sand- 
 stone. 
 
 c. An aggregate of the fragments of both. 
 
 These are general and belong to the secondary 
 sandstones mostly to the lowest. 
 
 They are mentioned under the heads of the dif- 
 ferent rocks to which they belong. 
 
 L. Sandstone and argillite, or shale, united : 
 general. The sandstone usually forms the base 
 is enumerated under that head. 
 
 Third Division. 
 
 Consisting of three or more rocks, o substances 
 united. 
 
 These are the most common : they consist of frag- 
 ments, rounded or angular, or both, united by 
 means of clay, sand, and gravel, derived from the 
 same substances. 
 
 A Fragments of quartz, and of a greater or less 
 number of primary rocks, united. 
 
 In various states, this forms conglomerates at- 
 tached to sandstones, under which head it is men* 
 tioned. It maybe primary or secondary, the former 
 containing the more limited number of ingredients. 
 
 B. Fragments of primary rocks with limestones. 
 
 C. Fragments of the same rocks with trap. 
 
349 
 
 This is similar to A. and is found in connection 
 with trap. 
 
 D. Fragments of granite, limestone, quartz and 
 gneiss imbedded in mica schist. 
 
 This is found where limestone accompanies mi- 
 ca schist or where the latter rock and gneiss ap- 
 proximate to granite. 
 
 E. Fragments of several primary or secondary 
 rocks, or both, with fragments of trap. 
 
 This is a trap tuff, and noticed with the overly- 
 ing rocks. It is in this and a few similar varieties 
 of the most recent origin that organic remains have 
 occasionally been found. 
 
 Some of the finer varieties of these rocks are 
 noticed under the head of argillite, being frequent- 
 ly termed grey wacks. 
 
 46 
 
TABULAR ARRANGEMENT 
 
 OF 
 
 FORMATIONS, 
 
 Observed in both Hemispheres (1822) 
 
 BY 
 
 BARON HUMBOLDT. 
 
 Roman numerals are perfixed to the names of 
 those formations, which being very seldom want- 
 ing, and consequently extending most generally, 
 may be considered as geognostic horizons. 
 
 Primitive Formations. 
 \. Primitive granite. 
 
 Primitive granite and gneiss. 
 Stanniferous granite. 
 Weistein with serpentine. 
 II. Primitive gneiss. 
 
 Gneiss and mica-slate. 
 
 Granite posterior to gneiss, anterior to mica- 
 slate. 
 
 Primitive sienite ? 
 Primitive serpentine ? 
 Primitive limestone. 
 
 The five latter formations, placed between gneiss 
 and primitive mica- slate, are parallel formations. 
 
351 
 
 III. Primitive mica-slate. 
 
 Granite posterior to mica-slate, anterior to 
 
 clay slate. 
 
 Gneiss posterior to mica-slate. 
 Greenstone slate ? 
 
 IV. Primitive clay slate. 
 Quartz rock. 
 
 Granite and gneiss posterior to clay slate. 
 Primitive Porphyry. 
 
 V. Primitive euphotide, posterior to clay slate. 
 The four latter formations, are parallel to each 
 other, sometimes even to primitive clay slate. 
 
 Transition Formations. 
 I. Granular talcose limestone, transition mica 
 
 slate, and grauwacke with anthracite. 
 II. Transition porphyries and sienites, immedi- 
 ately covering primitive rocks ; black lime- 
 stone and greenstone. 
 
 HI. Transition clay slate, containing grauwacke, 
 greenstone, black limestone, sienite and 
 porphyry. 
 
 IV. & V. Porphyries, sienites, and greenstonepos- 
 terior to transition clay-slate, some times 
 even to limestone with orlhoceratites. 
 VI. Transition euphotide. 
 
352 
 
 Secondary Formations. 
 
 I. Great coal deposit, red sand stone, and secon- 
 
 dary porphyry (with interposed amygdaloid r 
 greenstone and limestone.) 
 Secondary quartz rock, 
 
 The latter formation is parallel to coal-sand- 
 stone. 
 
 II. Zechstein or alpine limestone (magnesian 
 
 limestone ) : hydrated gypsum ; rock salt. 
 The five following formations which are very un- 
 equally developed may be comprehended 
 under the general name of 
 
 III. Arenaceous and calcareous deposits (marly 
 and oolitic, placed between the zechstein 
 and the chalk, and connected with these 
 two formations.) 
 
 Clay and variegated sandstone (sandstone 
 with oolite : sandstone of Nebra; new red 
 sandstone and new red marl) with gypsum 
 and rock salt. 
 
 Muschelkalk (shell, limestone; of Gottinguen.) 
 Quardersandstein (sandstone of Konigstein.) 
 Jura limestone (lias, marie, and great oolitic, 
 
 deposits. 
 
 Ferruginous sand and sandstone, secondary 
 sandstone with lignite (iron sand and green- 
 sand.) 
 
IV. Chalk. 
 
 Tertiary Formations. 
 
 I. Clay and tertiary sandstone with lignite (plas- 
 tic clay, molasse, and nagelfluhe of Argovia.) 
 
 II. Limestone of Paris fcalcaire grossier, or lime- 
 
 stone with cerithia, a formation parallel 
 to the London clay, and to the arenaceous 
 limestone of Bognor.) 
 
 III. Siliceous limestone, gypsum with bones, al- 
 
 ternating with marl (gypsum of Mont- 
 matre.) 
 IV. Sandstone, and sand above the gypsum with 
 
 bones (sandstone of Fontainebleau.) 
 V. Fresh -water formation with porous millstones 
 (meuliere above the sandstone of Fontaine- 
 bleau (limestone with (lymneae.) 
 
 Formations (exclusively} volcanic. 
 I. Trachytic formations. 
 
 Granitoid and sienitic trachytes. 
 
 Porphyritic trachytes (feldspathic and pyrox- 
 enic.) 
 
 Phonolites of trachytes (simi-vitreous trachy- 
 tes.) 
 
 Pearlstone with obsidian. 
 
 Millstone and cellular trachytes, with silice- 
 ous nodules. 
 
354 
 
 Trachytic and pumce conglomerates, with 
 alumstone, sulphur, opal, and opalised 
 wood. 
 II. Basaltic formations. 
 
 Basalt with olivin, pyroxene, and a little horn- 
 blende. 
 
 Phonolite of basalt. 
 
 Dolerite, 
 
 Cellular Mandelstein. 
 
 Clay with p) rope-garnets. 
 This small formation seems to be connected 
 with the clay with lignite of the tertiary formation, 
 over which currents of basalt are often spread. 
 
 Conglomerates with basaltic scoria?. 
 
 III. Lavas that have issued from a volcanic crater 
 (ancient lavas, vast masses generally abound- 
 ing in felspar; modern lavas with distinct 
 currents of small breadth ; obsidian with la- 
 va and pumice of obsidian.) 
 
 IV. Volcanic tufa, with shells. 
 
 Deposits of compact limestone, marl, clay with 
 lignite, gypsum and oolite, super posed on the most 
 modern volcanic tufas. These small local forma- 
 tions belong perhaps to the tertiary rocks : Table- 
 land of Rio bambo : isles of Fortaventura and 
 Lancerote. 
 
ARRANGEMENT OF ROCKS, 
 
 On the principles of Werner, by his pupil Pro- 
 fessor Jameson, of Edinburgh, and which may be 
 considered as " Werner's own" as it is probable 
 that ' the celebrated Geognost would have made 
 similar modifications in his original arrangement. 
 CLASS I. Primitive Rocks. 
 
 1. Granite, with Sienite 6. Primitive trap. 
 
 and Topaz rock. 7. Serpentine. 
 
 2. Gneiss, with White- 8. Euphotide, or Dial- 
 
 stone, lage rock. 
 
 3. Mica slate. 9. Porphyry. 
 
 4. Clayslate (Argillite.) 10. Quartz rock. 
 
 5. Primitive limestone, 
 
 and Gypsum. 
 
 Cuss If. Transition Rocks. 
 
 1. Greywacke, including 5. Serpentine. 
 
 transition Clay slale 6. Quartz rock. 
 
 2. Limestone. 7. Red sandstone. 
 
 3. Granite, and Porphyry 8. Trap. 
 
 4. Gneiss, and Mica Slate. 9 Gypsum. 
 
 CLASS III Secondary Rocks. 
 
 1. Sandstone, including 3. Gypsum, including 
 
 the coal formation. Salt. 
 
 2. Limestone, including 4. Trap, including se- 
 
 Chalk. condary Sieuite. 
 
 CLASS IV. diluvial Deposits. 
 CLASS V. Volcanic Rocks* 
 
TABULAR VIEW, 
 
 BY 
 
 DR. MACCULLOCH. 
 
 I. PRIMARY CLASS. 
 
 Unstratified. 
 
 Granite. 
 
 Stratified. 
 
 Gneiss Red Sandstone. 
 
 Micaceous Schist Argillaceous Schist 
 
 Chlorite Schist. Diallage Rock. 
 
 Talcose Schist. Limestone. 
 
 Hornblende Schist. Serpentine. 
 
 Actynolite Schist. Compact Felspar, 
 
 Quartz Rock. 
 
 II. SECONDARY CLASS. 
 
 Stratified. 
 
 Lowest (red) Sandstone. Limestone. 
 Superior Sandstones Shale. 
 
 Unstratified. 
 Overlying (and venous) Pitchstone, 
 
 Rocks. 
 
 Ill Occasional Rocks. 
 
 Jasper. Gypsum. 
 
 Siliceous Schist. Conglomerate Rocks, 
 
 Chert. Veinstones. 
 
 APPENDIX. 
 
 Volcanic Rocks. Alluvia, 
 
 Clay, marl, sand. Lignite. 
 
 Coal Peat. 
 
357 
 LIST OF FOSSILS FOUND IN THE UNITED STATES. 
 
 MEGATHERIUM 
 
 TEREBRATULITE 
 
 MEGALONYX 
 
 ARCA 
 
 MASTODON 
 
 MACTRA 
 
 ELEPHAS 
 
 DONAX 
 
 BOS 
 
 OSTREA 
 
 CERVUS 
 
 GRYPHEA 
 
 BALENA 
 
 PERNA 
 
 MANATUS 
 
 PAT XL A 
 
 
 CONUS 
 
 ICTHYOSAURUS 
 
 CONULARIA 
 
 PLESIOSAURUS 
 
 TEREBELLUM 
 
 SAUROCEPHALUS 
 
 MUREZ 
 
 TESTUDO 
 
 STROMBUS 
 
 
 TURBO 
 
 SQUALUS 
 
 PLANORBIS 
 
 RAIA 
 
 TURRITELLA ] 
 
 ACIPENSER and many undeter- 
 
 SERPULA 
 
 mined genera and species* 
 
 BALANUS 
 
 MEDUSA 
 
 GLYCEMERIS 
 
 CANCER 
 
 CYTHEREA 
 
 TRILOBITE 
 
 PRODUCTUS 
 
 ASTERIA 
 
 PENTAMERUS 
 
 ECHINUS 
 
 VENUS 
 
 CARYOPH1LLIA 
 
 CARDIUM 
 
 PENTREMITE. 
 
 CARDITA 
 
 ENCRINITE 
 
 VENERICARDIA 
 
 
 CUCULL^EA 
 
 AMMONITE 
 
 ANOMIA 
 
 NAUTILITE 
 
 NER1TA 
 
 BELEMNITE 
 
 PECTUNCULUS 
 
 ORTHOCERATITE 
 
 TRIGONIA 
 
 NATICA 
 
 MYTILLUS 
 
 OLIVA 
 
 AMPHIDESMA 
 
 CARDITA 
 
 CORBULA 
 
 BILOBITE 
 
 PANOP(EA 
 
 In a paper recently read before the 
 Lyceum of Natural History, Dr. De- 
 
 CRASSATELLA 
 ISOCARDIA 
 
 kay has attempted to show that near- 
 ly all the fossil fish from the great de- 
 pository at Westfield (Mass.) and 
 which have been referred to the ge- 
 
 CALYPTREA 
 LUCINA 
 ASTARTE 
 
 nus Paleothrissum of Blainville, are 
 
 FUSUS 
 
 not generically distinct from the Esox 
 Osseus, or bony scaled pike of the 
 Mississippi 
 
 FULGUR 
 DISPOTfEA 
 
358 
 
 PECTEJN 
 
 HELIX 
 
 PLICATULA 
 
 SERPULA 
 
 CELLAPORA 
 
 MILLEPORA 
 
 ALVEOLITE 
 
 FAVOSITE 
 
 TUBIPORA 
 
 TURBINOLIA 
 
 ASTREA 
 
 MADREPORA 
 
 OCUL1NA 
 
 CORALLIUM 
 
 PENNATULA 
 
 SERTULARIA 
 
 ALCYONITE 
 
 ORBULITE 
 
 BACCULITE 
 
 FASCIOLITE 
 
 DENTALIUM 
 
 AMMONITE 
 
 NUMMULITE 
 
 SPIRULA 
 
 FELICES 
 PALMA 
 QUERCUS 
 JUGLANS NIGRA 
 FAGUS. 
 
 The following fossils have heen enumerated by Dr. Bigs by 
 in his geological papers on the country around Lakes Huron and 
 Erie. 
 
 TRILOBITE 
 AMMONITE 
 ORTHOCERATITE 
 CONULARIA 
 TEREBRATUL^E 
 PRODUCTS 
 ENCRINIS 
 CARYOPH1LLIA 
 TURBINOLIA 
 ASTREA 
 
 CELLULAR and chain MAD- 
 REPORES, STRUES, and 
 
 RAMOSA, RETEPORES and 
 FLUSTRA, in great abund- 
 ance. Nine new varieties of 
 
 MADREPORES 
 
 LINGULA 
 
 CALYPTR3EA r 
 
 CERITHEUM 
 
 UNIO 
 
 MYT1LUS 
 
 GRYPHEA 
 
 ARCA 
 
 LILLY &PEAR ENCRJNITE, 
 
 THE END. 
 
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