ancient forests and many theories have been proposed concerning the accumulation of such great quantities of timber. Some suppose it to have been floated into a large basin by violent streams and inundations; others argue, that it must have been reared in its present locality, on account of the upright position of many of the trunks found in the mineral. The latter notion is absurd; as every naturalist knows, that so great a quantity of vegetable matter cannot grow together, and a new generation of trees would require a new earthly soil in which to vegetate; so that, instead of one dense stratum of coal, we should necessarily have a number of very thin strata, with thick beds of mould intervening. Now, supposing our coal-fields to have originated from the remains of ancient timber, let us attempt to form an idea of the rapidity with which it might have accumulated, from the following authenticated facts.

A mass of timber, ten miles in length, two hundred and twenty yards wide, and eight feet deep, was collected in one arm of the Mississippi in about thirty-eight years, in consequence of some obstruction in the channel of the river. This raft is continually increasing, and, although floating, is covered with green bushes, and a variety of beautiful flowers. At this rate, Dr. Smith might get a capital coal-field in a single century; by merely supposing a great mass of mud to fill up such a valley, (as has often occurred,) thus diverting the river-course, and pressing the accumulated timber and vegetable remains by its superincumbing weight, or in any other way that coal is made, for we have never been present at its manufacture. Again, we are assured, that "great deposits have been in progress at the extremity of the Delta in the bay of Mexico;" and that Captains Clark and Lewis found a forest of pines standing erect under water, in the body of the Columbia river, in North America, which they supposed, from the appearance of the trees, to have been submerged only about twenty years. So, after the earthquake in Jamaica, in 1692, the rivers were found to have carried down many hundred thousand tons of timber, which appeared like islands in the sea. The inhabitants of Greenland are dependent for their entire supply of wood upon drift timber, which, according to Crantz, is originally washed down from the mountains of Siberia, and floated to Greenland in vast quantities by currents of the ocean. Finally, in 1810, the bursting of a drain in lake Vermont produced a great inundation, by which heaps of wood were formed to the height of eighty feet.

Taking all these circumstances into account, as a very few examples of the vast collections of vegetable substances that are frequently taking place; and remembering that many of these trees are represented as retaining their erect form, we humbly conceive, that any geologist who is an adept at making coals out of decomposed wood, may easily find materials wherewith to perform his work, without having recourse to the tedious plan of growing them upon the spot where he intends the mineral fuel to be laid.

Let us glance at another sort of formation. The enormous deposits of mud which are seen in many countries, as in the basin of the Tay, Isla, and North Esk rivers in Scotland-alluvions hundreds of feet thick, which are neither stratified nor laminated like the sediment which subsides from water," are said by Mr. Lyell to be very analogous to those "mud lavas” that are still emitted by volcanoes, filling up large valleys at a single eruption. The same author remarks, that "as a continued series of such eruptions as man has witnessed would reproduce another cone like Etna, so a sufficient number of earthquakes like that of 1783 would enable torrents and rivers to re-excavate all the Calabrian valleys, if they were now to be entirely obliterated. It must be evident, that more change is effected in two centuries, in the width and depth of the valleys of that region, than in many thousand years in a country as undisturbed by earthquakes as Great Britain." Now, as our island was evidently the seat of volcanic influence at a former period, it appears that a few ages would be sufficient time for effectuating all the wonderful phenomena, for one part of which Dr. Smith allows some "thirty thousand years." Whether is Smith or Lyell in the right?

The length of time requisite for the superposition of soil between different strata, has long been a question amongst geologists. But when we are told, that over the tuff which envelopes the ruins of Herculaneum, there is "the matter of six eruptions, each separated from the other by veins of good soil;" and that "the Vesuvian lava of 1767 is already covered with a luxuriant vegetation," we feel that any speculation upon the subject is unworthy of the least attention.

The slow abrasion of rocks by the force of water is produced by Dr. Pye Smith, as an incontrovertible proof of the immense age of some mountainous districts, where a stream of water has cut through a rock of one or two hundred feet in thickness.

But such tardiness of operation as that imagined by the Doctor does not always seem to be exhibited. Mr. Lyell offers a very different view of the case: "After the heavy rains which followed the eruption of Vesuvius in 1822, the water flowing through the Atrio del Cavallo cut, in three days, a new chasm through strata of tuff and volcanic ejected matter, to the depth of twenty-five feet." Again: "In the course of two centuries, the Simeto has eroded a passage from fifty to several hundred feet wide, and in some parts from forty to fifty feet deep." Yet this lava, though comparatively recent, is said to be as hard as the most ancient trap-rocks of Scotland, and to have such an appearance of antiquity, as that a spectator might suppose himself to be standing in the rocky gorge of a primary district. These occurrences, however, are reported "to be trifling when compared with the great gorges which are excavated in somewhat similar materials in the great plateau of Mexico. We must not infer, that, because a stream now flows with limpid waters, producing a very slight abrasion of its rocky bed, it was not once the vehicle of many mountain-fragments, which would cause a speedy erosion of the hardest strata. From the above facts, we must insist that this pretended proof of the antiquity of certain rocks be wholly renounced.

Some geologists allow a long period for the upraising of hilly districts; and, pointing to the shells lying upon their summits, calculate an immense time to have elapsed since these testacea were thrown alive upon a sea-beech, which has now become a mountain. It is true, that we have no recent examples of a considerable elevation taking place in any large tract of country; but we cannot thence argue that such has not been the case in former ages, especially as geologists conjecture that volcanic agency was once much more active than it is at present. We have late instances of a long line of coast being raised a few feet during the shocks of an earthquake; and the action of subterraneous forces upon smaller portions of ground has been very considerable. Through their medium, mountains have been raised, lowered, or split into many parts; valleys have been filled

lakes have been formed through the subsidence of the soil; considerable tracts of land have been swallowed up; new islands have been formed, and old ones engulfed; villages, towns, and even large cities, have entirely disappeared; and whole districts have been depopulated, as if swept with the besom of destruction. In 1812 "the whole valley from the mouth of the Ohio

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to that of St. Francis, including a front of three hundred miles, was convulsed to such a degree as to create new islands in the river and lakes in the alluvial plain, some of which were twenty miles in extent." An eruption in Mexico during the year 1755 at once produced a mountain one thousand seven hundred feet in height! The spot where the old quay of Lisbon stood is now one hundred fathoms under water. The volcano of Cotopaxi has thrown a rock of one hundred cubic yards in volume, to the distance of eight or nine miles; and during an earthquake, waves of the sea, sixty feet high, have flowed in upon the land, carrying all before them, and covering the shore with testacea and other marine substances.

That vast tracts of alluvial soil once composed the beds of large rivers, will be readily imagined by any person conversant with the history of fluviatile action. Modern geography informs us of great alterations produced in mighty streams by the accidental presence of very slight obstructions in their channel; these hinderances being speedily increased by the vast quantity of sediment brought down the current, until the river has overflown its banks, and made for itself a new course through the fertile valleys. From Captain Hall's Travels in North America, we learn, that "some years ago, when the Mississippi was regularly surveyed, all its islands were numbered, from the confluence of the Missouri to the sea; but every season makes such revolutions, not only in the number, but in the magnitude and situation, of these islands, that this enumeration is now almost obsolete. Sometimes large islands are almost melted away; at other places they have attached themselves to the main shore, or, which is the more correct statement, the interval has been filled up by myriads of logs cemented together by mud and rubbish."

Having thus given a few examples of the amazing power of volcanic agency, and of the changes that are produced by running water, let us connect them with some instances of marine depositions.

Several species of shells, identical with those living in the neighbouring seas, are found in Sicily and Calabria, at the height of some thousand feet. The shock which destroyed Penco, in Chili, allowing the water to flow over the town, raised the bed of the sea at least twenty-four feet, and exposed a vast bed of shells similar to those which cover the adjoining hills at the height of more than a thousand feet. When our surveying

vessels were obliged to leave their moorings near the mouth of the Rhone, on account of a strong breeze from the sea, they found on their return the new sand-banks covered with a great quantity of marine-shells; and we understand that, on account of the sand-bars formed at the mouth of this river, some of the etangs are alternately salt and fresh, according as the storms of the ocean or the floods of the river occupy the enclosed spaces. A similar occurrence takes place on the coast of Aberdeenshire, ten miles north of Peterhead, in Scotland; where the outlet of a small stream being choked up, about one hundred and fifty years ago, by the drifting of sand, the lake of Strathby was formed, covering a square mile of country. Sometimes the sea breaks through the sandy barrier, and covers the tract with salt water; but by a new deposition of matter, it is again excluded, and the lake resumes its former freshness. Slapton Lee is an example of the same character.

Does not the former class of facts above-mentioned show how easily the most elevated marine-fossils may have been raised to their present situation? And does not the latter explain how quickly several salt and fresh water deposits may follow one another? Now, supposing that five thousand years elapsed between the creation and the time when France and Britain were first known to the civilized world; who shall say what took place during that long period? That they both were under the influence of powerful volcanic agency, is evident to every geographer; and who shall give the dates, or describe the consequences, of such eruptions, with their attending earthquakes, and succeeding inundations? That the whole might have been easily accomplished in a short time, cannot well be denied, admitting the presence of those powerful agencies which have been in recent operation in other parts of the world. And that great devastations may have taken place, without any remnant of the crater's being now visible, is evident from the fact, that eighty large towns in central India were overwhelmed by a shower of ashes, though there is not now any appearance of a volcano for the distance of nearly three hundred miles.

Are the mountains of Sicily and Calabria ante-Mosaic? If so, their imbedded fossils, which are identical with existing testacea, lived before their creation, as mentioned in the Bible. If otherwise, the same power which upraised them could elevate any other region of the globe. We neither affirm nor deny the prior existence of our planet; but we cannot help thinking, that