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    December 13,1856.] T H E L E A P ER. 119...

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    s 1 * < i < to to so - . and , of - MISC...

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    An Admirable Book On Geology. Advanced T...

    and deduction , and is little aided ^ by conjecture , 'however plausible and possible" Here it is forgotten that deduction itself is but conjecture , until it is -verified ; it is forgotten that all the greatest discoveries in science are made on the pathway of conjecture ; itis forgotten that Kepler framed seventeen guesses and Uewtori . framed several successive conjectures , before the one dis- covered the true path of the planets , and the other the true composition of li ^ ht . ¦ : ¦ ¦ ¦ ¦ Mr . Page's plan is first to lay down the principles and more conspicuous facts necessary for the understanding of each section of the subject , and then to close the section with an explanatory and recapitulatory survey . He adds numerous woodcuts , and an extensive glossary . Solicitous of being minutely instructive to the young geologist , he has indicated many details which other writers pass over as trivial , but for which the student will be grateful . But the work is really of interest to others besides mere students , and those best acquainted-with geology will be its warmest admirers . We will extract a passage or two which can be read without reference to the context : — - The agencies that now operate on . and modify the surface of the Globe—that scoop out valleys and wear down hills ; that fill up lakes and estuaries and seas ; that sub- merge the dry land and elevate the sea-bottom into new islands ; that rend theroclcy crust and throw up new mountain-chains ; and that influence the character and dis- tribution of plants and animals , are tlie same in kind , though , differing it may be in degree , as those that have operated in all time past . The layers of mud and sand and gravel now deposited in our lakes and estuaries and along the sea-bottom , and gradually solidifying into stone before our eyes , are the same in kind with the shales and sandstones and conglomerates that compose the rocky strata of the globe : the marls of our lakes , the shell-beds of our estuaries , and the coral-reefs of existing seas , year after year increasing and hardening , belong to the same series of materials , and in process of time will be undistinguishable from the chalks and limestones and marbles we quarry : the peat-mosses , the jungle-growth , and the vegetable drift that have grown and collected within the history of man , are but continuations of the same formative power that gave rise to tlie lignites and coals of the miner ; the molten larvas of JEtna and Vesuvius , and the cinders and ashes of Hecla , are but repetitions of the same materials which now compose the basalts and greenstones and trap-tuffs of the hills around us ; while the corals and shells and fossils , the fragments of plants and skeletons of animals now imbedded in the mud of our lakes and estuaries andseas , will one day or other be converted into stone , and tell as marvellous a tale as the fossila we now exhume with such interest and admiration- Without this uniformity in the great operations of nature , the history of the Past would he an uncertainty and delusion . We can only read the past as connected with the present 5 and premise of the future from what is now going on around us .

    The following passage , on the operation of Rivers , is a good specimen of s the compact , clear style in which the work is "written : — 1 Streams and rivers—in fact all winter currents—act chiefly in a mechanical way , * and their influence depends partly on the nature of the rocks over -which they run , the < rapidity of their flow , and the size or volume of water . If the rocks over which they i pass be of a soft or friable nature , they soon cut out channels , and transport the < eroded material in the state of mud , sand , and gravel to the lower level of some lake , to their estuaries , or to the bed of the ocean . Their cutting as -well as transporting power is greatly aided by the rapidity of their currents ; hence the power of mountain torrents compared with the quiet and sluggish flow of the lowland river . It has heen calculated , for example , that a velocity of 3 inches per second -will tear up fine clay , that 6 inches will lift fine sand , 8 inches sand as coarse as linseed , and 12 inches fine gravel ; while it requires a velocity of 24 inches per second to roll along rounded pebbles an inch in diameter , and 36 inches per second to sweep angular stones of the size of a hen ' s egg . During periodical rains and land-floods the currents of rivers often greatly exceed this velocity ; hence the tearing up of old deposits of gravel , the sweeping away of bridges , and the transport of blocks many tons in -weight—an operation greatly facilitated by the fact that stones of ordinary specific gravity ( from 2 . 5 to 2 . 8 ) lose more than a third of their weight by being immersed in water . Nor is it the mere velocity of rivers which produces their eroding or cutting power , but the amount and nature of the debris carried down by their torrents—every pebble and block of shingle rubbing and striking and grinding still deeper and deeper the channels down which they are borne . The geological effects of rivers on the crust is thus of a twofold nature—viz ., to waste and wear down the higher lands , and then to bear along the waste material and deposit it in valleys , in lakes , or iu the ocean , in the state of mud , clay , sand , or gravel . By such deposits lakes are silted or filled up , and become alluvial valleys ; estuaries converted into level plains ; and even large tracts reclaimed from the sea . ... Every person must have observed the rivers in his own district , how they become muddy and turbid during floods of rain , and how their Bwollen . currents cat away the banks , deepen the channels , and sweep away the sand and gravel down to some lower level . And if , daring this turbid state , he will have the curiosity to lift a gallon of the water , and allow it to settle , he will be astonished at the amount of sediment or solid matter that falls to the bottom . Now , let him multiply this gallon by the number of gallons daily carried down by the river , aud this day by years and centuries , and he will arrive at some faint idea of the quantity of matter worn from the land by rivers , and deposited by them in the ocean . In the same way as one river grinds and cuts for itself a channel , so does every ^ stream and rill and current of water . The rain as it falls washes away what the winds and frosts have loosened : the rill takes it up , and , mingling it with its own burden , gives it to the stream ; the stream takes it up and carries it to the river ; and the river bears it to the ocean . Thus the whole surface of the globe is worn and grooved and channeled —the higher places being continually worn down , and the wasted material carried to a lower level . And this explanation of the process of petrifaction will l > e read with interest : — The process of petrifaction , generally speaking , consists in the infiltration of stony matter into tho pores of vegetable or animal substances . . In some instances the organic body haa almost entirely disappeared , and the stony matter has been so gradually substituted , particle for particle , that the pctrifacfon presents a perfce rc-Bemblanco in its minutest parts to tho original structure , l ' etrifnct . oi has been artificially imitated by burying bones in imul , clay , and lime , and it liaa been found that after a time the bones become black , harder , and heavier ; and had the process been continued , they would havo eventually beun undistinguishable from true lossils . Spring holding lime or flint in solution are familiar examples of petrifying agents when they convert pieces of moss , straw , twigs , and branches , into calcareous and siliceous matter . Lime and flint nrc perhaps tho most abundant petrifying substances in nature ; but many fossil bones and shells arc converted into metallic crystals , vegetable remains into bituminous masses like coal , and not unfrequently trunks of trees have their forms perfectly preserved in strata of fine-grained sandstone . With-. ' I 1 i i ' ? 3 ° I ° 3 ' 10 I > n u S 3 Is ts , id es is of , h-

    o ° ^ n n T c r i * t i £ ] i . ¦ out entering upon the obscure , and as yet little studied , processes by which organic substances are preserved in the crust of the earth , we may notice a few of the more obvious , rather with a view to indicate the nature of the subject than attempt to teach its details . A shell , like the common cockle , may be burried in a mass of calcareous mud , and when so enclosed it is of itself composed of carbonate of lime and a little animal matter . As it remains imbedded chemical changes take place—the animal matter decomposes and passes off in a gaseous state , and its place is supplied by an additional infiltration of lime from the mass . If iron 5 a solution be present in the mud , the sulphuretted hydrogen arising from the animal decomposition will unite with the iron , and the shell will become coated cr incrusted with shining iron pyrites , or sulphuret of iron . As the calcareous mass becomes consolidated into limestonerock , the shell will also become hard and stony , hut still preserving its form to the minutest ridge and corrugation of its exterior surface . By-and-by , carbonated waters may filtrate through the pores of the limestone ; the shell may be dissolved entirely , and leave only a hollow cast of its form . Another change may now take place : water holding siliceous matter may percolate through the reck , and the hollow shell-cast be filled entirely with flint . As with flint , so with crystallized carbonate of lime , with iron pyrites , 01 even with a soft clayey deposit that yields to the scratch of the nail . All these are possible changes , and changes which every day present themselves to the palaeontologist ; and as with a shell , so . with a tooth , a fragment of bone , a fish scale , a mass of coral , the net-work of a leaf , or the woody fibre of a drifted pine-branch . The structure of the organism is always-more or less preserved , and forms a basis for the petrifying solution , which thoroughly pervades it without disturbing the arrangement of those parts on -which its characteristic form depends . It is this form or ^ external character which enables the palaeontologist to compare and classify fossils with existing plants and animals ; and it is this internal arrangement of cell and fibre , as revealed to the microscope , that enables him to detect bone from shell , and the bone of a bird from the bone of a mammal . These three passages sufficiently indicate the quality of the book ; its mer its as a text-book can only be estimated by the student himself , jf it does not drive many a student , hammer in hand , into quarries and railway cuttin gs for immediate experience of geological phenomena , nothing will .

    December 13,1856.] T H E L E A P Er. 119...

    December 13 , 1856 . ] T H E L E A P ER . 1193

    S 1 * < I < To To So - . And , Of - Misc...

    MISCELLANIES LIGHT AND LEARNED . Preceb-euce to beauty—we have Sir Walter Scott ' s Lord of the Isles ( Edinburgh : A . and C . Black ) , in a rich binding of Ted , blue , and goldv exquisitefy printed on tinted paper , and illustrated by seventy-two illustrations , from drawings by John Gilbert and Birket Foster . The introductions b j Scott are all reproduced , together with a variety of notes . The volume is superb ; its external appearance will entice many an eye m search of a seasonable gift-book . Some of the illustrations are of the highest merit , and wonderfully in keeping with the character of the poem . These bright editions almost atone at Christmas for the absence ^ of flowers . But we are dealing , at present , with works of all classes ^ icb- do not atot of more ample treatment . Let us note , then , tnat Miss Meteyard , the Silverpen of former days , presents , as /^ Christmas offeraig , Lilians Golden Hours ( Routledge . )—ItTis an . elegant tale for the young , elegantly illustrated by Absolon . We must forgive Miss Meteyard her didactisms and her moralities , as well as the simple egotisms of her preface , on . accounti xrf the genial , generous sentiments with which her writings are imbued . Mrs . Hubback , too , must be mentioned with praise , as the author of Agnes Mtlbourne ; or , Foypour Devoir ( Skeet ) . —The praise , however , applies to the . form rather fha / to the matter of her story , which is a variation from the three-volume conventionality . The volumes , besides being only two in number , are : small , in size . As for the novel , those who remember " The Wife ' s jester' ' ? The Old Vicarage , " will know what amusement and what edification to anticipate from the history of Agnes Milbourne . We are really at a loss how to apply the teachings conveyed in Mrs . Hubback sGesta . Help iVl ' vne of Need ! or , the Lord Careth for his Own ( Edinburgh : Kennedy ) , is a tale founded on the persecution of the Huguenots , by Miss Catherine D . Bell , who reminds her friends and the public that she has produced eleven similar volumes , the names of which are set forth , with conscious pride , upon her title-page . The story is carefully executed , and exhibits a good deal of liberal and healthy feeling . It may be recommended to voun * readers . Another sort of narrative comes to us from America . It is anonymous , but purports to be The Autobiography of a Female Slave ( Trubner ) . —We have no doubt that it is a mere faction . ^ the scenes being of a grossly exaggerated description , the characters theatrical , the style that of a Lascar pamphlet . One remark has been suggested to us by this epic of stripping , whipping , and melodramatic atrocity . _ The friends of the black luwe a lingulai- abhorrence of the true Nigritian stain . They almost in , variably make their heroines white or nearly so ; accordingly , the female slave of this « Autobiography" is depicted as having " a very iair and beautiful complexion , " » no perceptible shade darker" than that of her free-born mistresses . She is , indeed , altogether lovely , and devotes many a page to revelations of shame and suffering connected with her own displays at the whippin-post . We much question whether this sort of literature helps JLeabofitList cause , and sometimes are disposed to doubt whether it is ^^ S ^ S \ h ? 5 Se subject is an interesting volume , Anthony Burns : a History , by C . B . Stevens ( Trubner ) , being a mmute narrative of an extradition case which occurred in Boston two years ago , under the * ugitive Slave Act . In the course of his relation , ^' . Stevens sketches the portraits of two abolitionist orators , Wendell Phillips and Theodore Parker . The contrast being thoroughly American in tone and spirit , wo will make room . for it : — Tberc were two men in the Hall for whoso words , more than for those of all others , the ^ assembly impatiently waited . The * were Wendell Phillip , and Theodore Parker .. Kecarded by the public as tho loaders of tho present cnterpnze , closely associated m iS ami ? urP 06 c , and eminent , botli , for tho power of speech , they yet diffowd f om each othdr in many particulars . Mr . Phillips belonged ^^ T ^ S S o ns such a class may bo supposed to exist » a this country . He had an ancestry 10 boas of his SSy name was interwoven with the history of the Commonwealth ; ! « ml some of thoso who had Dome it had filled high , offices to tho flovemimnt . Mr Parker , on tho other hand , was of more pleixnan origin ; be ^^ 'M ^ Iu his ovn fortunes , and was by far tlio most distinguished person of las lineage .

• Citation
  • Leader (1850-1860), Dec. 13, 1856, page 17, in the Nineteenth-Century Serials Edition (2008; 2018) ncse-os.kdl.kcl.ac.uk/periodicals/l/issues/cld_13121856/page/17/