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of the sea, lead the author to recur to the opinion, on which he insisted in his former work, of the means which are thus afforded us for judging concerning the age of the world. The natural chronometers, as he terms them, coincide in reducing it to no very great antiquity; compared at least with that which has been assigned to it by Dr. Hutton.
In no one circumstance, as M. De Luc conceives, is the hypothesis of his opponents so defective as in respect to the scattered blocks, particularly of granite ; and on this point he dwells at considerable length, both in the preliminary remarks and in the observations which he makes during his travels. He shews that the most random conjectures have been formed in order to account for their present situation ; and he apprehends that every fact respecting them tends to prove that they were not conveyed from any distance, but that, at the birth of the continents, these masses were in some places where we at present see them. We think, however, that in this instance, as is so often the case in geology, the author has been much more successful in overthrowing the opinions of his adversaries than in establishing his own. He has, as we conceive, satisfactorily proved that these blocks could not have migrated from any discance, yet they must have been brought into the present situ. ation by some powerful cause ; and the one assigned is that of explosion from the bowels of the earth. These explosions are not supposed to have been produced by fire, because nothing in the appearance of the substances indicates the operation of this agent, but by the re-action of expansible fluids mechanically compressed: the great revolutions, which the surface of the earth has experienced, being, according to the author, chiefly owing to the subsidence of parts of its surface into large internal cavities filled with expansible fluids.
Now let us represent to ourselves the enormous compression exercised on these fluids, by the subsidence of masses so vast, that the changes of their level prepared for the future continent's the plains, the valleys and dales among the eminences, and the basins of lakes ; and we shall perceive that these fluids must, in the intervals of the large masses, through which they were compelled to escape, have possessed an impulsive power, fully capable of driving before them those fragments of the strata which we see on the surface, though the size of many of them be such, that no exterior force could move them, without the assistance of machines like those employed by Count CARBURI for the block at St.Petersburg.'
Our readers must judge of the plausibility of this supposition.
Another circumstance which M. De Luc regards as very ima portant, both to the confirmation of his own hypothesis and
more generally to the establishment of a correct view of geological phænomena, is that the sea has never altered its present level. This opinion he endeavours to confirm by numerous observations, made in the course of his travels along the shores of the Baltic and the German Ocean : but we have dwelt so long on his preliminary observations, that we must hasten to take some notice of the narrative part.
Commencing his route at Berlin, the author proceeded through Brandenburg and Mecklenburg to Rostock; hence he went along the coast of the Baltic to Wismar, Lubeck, Kiel, and Schleswig; from Schleswig he crossed the peninsula of Jutland and Husum ; and after having examined this neighbourhood, he embarked for England. The objects, which occupied him during his journey, were principally those to which reference is made in the preliminary observations; the scattered blocks of granite, the partial filling up of. valleys by the depositions of rivers, the still more considerable depositions which have been formed at the mouths of rivers and along the flat shores of the sea, the breaking down of steep cliffs, and the accumulation of a barrier at their feet, by which this operation is limited. He paid particular attention to the situation of lakes, in order to substantiate his opinion that they could not have been created by the excavation of streams ; and he made many observations which tend to prove that all the streams which run into the Baltic, as well as the Baltic itself, have never materially altered their present level. In the vicinity of Strelitz, and in many other parts of Mecklenburg, are collections of peat-moss ; and this circumstance led the author to make some remarks on the natural history of that substance, on its form. ation, and on the essential difference between peat and marsh. Almost all the lakes with which that country abounds are bordered with peat, and are gradually diminishing by its encroachments ; in all cases it is easy to perceive the original border of the lake, and to ascertain the quantity of the encroachment. By observing the growth of the peat in all its different stages, the author has been enabled to give what appears to be a very satisfactory account of the process. Where the declivity of the bank is small, and the stream is slow, a belt of reeds first makes its appearance along the edge, raising their stalks above the surface of the water. These stalks serve to collect a portion of the sediment which the water contains, and thus to form a suitable bed for the growth of other aquatic plants; which again, in their turn, increase the quantity of matter, and add to the solidity of the stratum. In common situations, however, this process goes on very slowly, because in each successive season the vegetables are decomposed, and til
leave behind them scarcely any solid residuum. Here we are led to the essential distinction between marshes and mosses : .
• Reeds have the same effect in the extension of marsh lands, on the borders of other lakes, and of some rivers ; but they differ there in one respect from these which I am now describing, by continuing to grow over the whole breadth of such lands, till the soil is at last raised above the level of the water ; because the other aquatic plants, which grow among them in summer, undergo an entire decomposition, and leave nothing remaining but a kind of mire. Now the essential distinction between peat-mosses and marshes consists in this : that, in the latter, the decaying vegetables proceed to the putrid decomposition, which extends to their constituent molecules, that is to say, those that constitute the vegetable substance ; and their residuum possesses no longer the combustible faculty: whereas, in peat-mosses, the decomposition of vegetables goes no farther than to reduce them into those molecules ; and thus the residuum, in this case, retains combustibility. And hence results another difference between marshes and peat-mosses: the neighbourhood of the former is unhealthy, because of the miasmata produced by the putrid decomposition ; that of the peat-mosses is in no respect injurious to health, because the constituent molecules do not undergo that decomposition.'
The difference between marshes and peat-mosses, as to the state of the vegetable matter in them, the author attributes to the water of peat-mosses ; which, by some cause that remains yet to be determined, acquires an antiseptic quality. This opinion is confessedly conjectural, but is plausible, and deserves farther investigation.
A minute account is given of the gradual progress by which this peat becomes converted into meadow-land; and from noticing it in all the different stages of the change, the conclusion appears to be fairly deduced that the waters of these lakes, in all cases, retain the same level which they originally possessed. Every observation tends to the same conclusion respecting the Baltic, that it maintains the same level now which it observed when the continents were formed. The chief argument, from which this conclusion is deduced, depends on the fact that the addition of peat in the one instance, and of new land in the other, is exactly on the same horizontal level with the line of original land. If the addition had depended on the subsidence of the waters, or even if they had been subsiding when the addition was made, it would necessarily have presented a sloping surface. • We cannot attempt to follow the author through his route, nor indeed to give an account of the different parts of it, but shall only remark that, after having examined the coast of the Baltic, and particularly noticed the operations which are going on at the mouths of rivers and in gulphs, he considers • E3
all all his former geological positions and opinions as substantiated. The account with which the work concludes, of the coast of the German Ocean, is very interesting : but it is too long for quotation ; and indeed we hope that our philosophical readers will be induced, from the remarks which we have made, to refer to the volume itself. We may observe concerning it that it possesses M. De Luc's characteristic qualities, both favourable and unfavourable ; it is prolix, and sometimes tedious, but it bears the marks of accuracy and fidelity; and although the truths which it contains may be occasionally buried rather deep, yet they are worth the trouble of digging up and bringing to the surface.
Arr. VII. Poems by William Robert Spencer. 8vo. 1os. Boards.
Cadell and Davies. 1811. The author of this well-printed volume has more than once 1 been introduced to our readers, and is known to rank among that class of poetical persons who have never been highly favoured hy stern criticism. The “ mob of gentlemen who write with case” has indeed of late years (like other mobs) become so importunate, as to threaten an alarming rivalry to the regular body of writers who are not fortunate enough to be either easy or genteel. Hence the jaundiced eye with which the real author regards the red Morocco binding of the presumptuous « Littérateur ;" we say, the binding, for into the book itself he cannot condescend to look, at least not beyond the frontispiece. --- Into Mr. Spencer's volume, however, he may dip farther, and will find sufficient to give him pleasure or pain, in proportion to his own candour. It consists chiefly of “ Vers d. Société,” calculated to prove very delightful to a large circle of fashionable acquaintance, and pleasing to a liniited number of vulgar purchasers. These last, indeed, may be rude enough to expect something more for their specie during the present scarcity of change, than lines to · Young Poets and Poetesses, • Epitaphs upon Years,' Poems to my Grammatical Niece,' • Epistle from Sister Dolly in Cascadia to Sister Tanny in Snowdonia,' &c. : but we doubt not that a long list of persons of quality, wit, and honour, “ in town and country," who are here addressed, will be highly pleased with themselves and with the poet who has shewn them off in a very handsome volume : as will doubtless the “Butterfly at the end of Winter,' provided that he is fortunate enough to survive the present inclemencies. We are, however, by no means convinced that the Bellman will relish Mr. S.'s usurpation of a Christmas
Carol;' which looks so very like his own, that we advise him immediately to put in his claim, and it will be universally allowed.
With the exception of these and similar productions, the volume contains poems eminently beautiful; some which have been already published, and others that are well worthy of present publication. Of • Leonora,' with which it opens, we made our report many years ago: (in Vol. xx. N. S. p. 451.) but our readers, perhaps, will not be sorry to see another short extract. We presume that they are well acquainted with the story, and therefore select one of the central passages :
• See, where fresh blood-gouts mat the green,
Ere on the bridal couch we lie.”
Their trackless footsteps rustle near, .
Oh God! oh leave, oh leave the dead !" Such a specimen of “the Terrible” will place the merit of the poem in a proper point of view : but we do not think that some of the alterations in this copy of Leonora are altogether so judicious as Mr.S.'s well-known taste had led us to expect. • Reviving Friendship’ (p. 5.) is perhaps less expressive than “ Relenting," as it once stood, and the phrase "ten thousand furlowed heroes' (ibid.) throws a new light on the heroic character. It is extremely proper that herocs should have “furlows,' since school-boys have holidays, and lawyers have long vacations : but we very much question whether young gentlemen of the scholastic, legal, or heroic calling, would be flattered by any epithet derived from the relaxation of their re