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examination, yet we conceive that the extreme fineness of the particles of which the prairie soil is composed, is probably the principal reason why it is better adapted to the growth of its peculiar vegetation, than to the development of forests. It cannot fail to strike the careful observer that where the prairie occupies the surface, the soil and superficial material have been so comminuted as to be almost in the state of an impalpable powder. This is due partly to the peculiar nature of the underlying rocks and the facility with which they undergo decomposition, and partly to the mechanical causes which have acted during and since the accumulation of the sedimentary matter forming the prairie soil. If we go to a thickly wooded region like that of the nothern peninsula of Michigan, and examine those portions of the surface that have not been invaded by the forest, it will be observed that the beds of ancient lakes which have been filled up by the slowest possible accumulation of detrital matter, and are now perfectly dry, remain as natural prairies, and are not trespassed on by the surrounding woods. We can imagine no other reason for this than the extreme fineness of the soil which occupies these basins, and which is the result of the slow and quiet mode in which they have been filled up...... Applying these facts to the case of the prairies of larger dimensions farther south, we infer, on what seems to be reasonable grounds, that the whole region now occupied by the prairies of the northwest was once an immense lake, in whose basin sediment of almost impalpable fineness gradually accumulated; and that this basin was drained by the elevation of the whole district, but at first so slowly, that the finer particles of the superficial deposits were not washed away, but allowed to remain where they were originally deposited. After the more elevated portions of the former basin had been laid bare, the drainage becoming concentrated in narrow channels, the current thus produced, aided perhaps by a more rapid rise of the region, acquired sufficient velocity to wear down through the finer material on the surface, wash away a portion of it altogether, and mix the rest so effectually with the underlying drift materials, or with abraded fragments of the rocks in place, as to give rise to a different character of soil in the valleys from that of the elevated land. This valley soil being much less homogeneous in its composition, and containing a larger proportion of coarse materials than that of the uplands, seems to have been adapted to forest vegetation; and, in consequence of this, we find

such localities covered with an abundant growth of timber." Where the so-called "groves" occur upon higher levels of the prairies, there is always a partial acccumulation of drift and other coarse materials, in place of true prairie-sediment; and the same is observable, according to Mr. Whitney, wherever timber is found upon the bottom-prairies of the Mississippi and Missouri valleys south of Iowa.

In the concluding and principal portion of Mr. Whitney's Report, numerous analyses are given of the dolomites, limestones, coals, and other economic substances, of the State; and the great lead region is described with much detail. The lead ore lies essentially in the Galena limestone, in "gash" or shrinkage veins, and in caverns, openings, or pockets, all of which are cut off at comparatively small depths beneath the surface. The whole of this portion of the Report is drawn up in an exceedingly clear and able manner, and will well repay the perusal of those interested in mining operations.

We have already alluded to the beautifully executed plates, in illustration of the Paleontology of the survey, engraved under the superintendence of Professor Hall. The letter-press to these is exceedingly copious, and contains many additional diagrams illustrative of crinoid structures. Another advantageous feature, as compared with the descriptions in the published volumes of the Paleontology of New York, is the definition of the various genera, given in connection with the characters of their respective species. All the described forms, however, belong to the Devonian and Carboniferous formations: the Silurian fossils, met with during the survey, having been previously figured in Dr. Owen's Report on the geology of Wisconsin, and in other publications. A few plates of the more characteristic of these fossils would contribute nevertheless to the utility of the present work, without any very material addition to its cost; and we trust the legislature of Iowa will afford the means of effecting this, in the volume which is yet to appear. To the enlightened legislature of this far western State-a State added but yesterday, as it were, to the Union-too much credit cannot be accorded for these goodly and important volumes, so useful to agriculture and practical art, and so liberally presented to the scientific world.

E. J. C.

Outlines of Natural Theology for the use of the Canadian Student. By James Bovell, M.D., Professor of Natural Theology in Trinity College, Toronto, C. W. Toronto: Printed by Rowsell and Ellis, 1859.

The accomplished author of this work is well known to the readers of the Canadian Journal, as occupying a prominent position in the scientific ranks of Canada; whilst, in the special departinent of physiology, his reputation has extended beyond the Province. The work now before us, unlike the general character of Dr. Bovell's writings, is strictly a compilation from various sources, put together in accordance with the author's special views; but this is fairly stated by Dr. Bovell, and is indeed in keeping with the proposed object and plan of the book: a book not intended for the critical investigation of the scientific inquirer, to whom the facts brought forward in it must necessarily be familiar, but one offered to the student of Natural Theology, as a convenient and accessible text-book, in the prosecution of his studies. This being the general intention of the work, it has been thought advisable to elucidate the subjects discussed in its pages, by a considerable number of wood-engravings and some lithographed geological sections. Of the engravings, chiefly restora tions of extinct reptilian and other types, some few, perhaps, might have been judiciously omitted; and, as the work is intended mainly. for Canadian students, it would have been as well-so far as regards the older rock formations-to have substituted Canadian subdivisions for the local terms and groupings more or less peculiar to the British Isles. Subordinate matters of this kind, however, can easily be rectified in a future edition; and in alluding to them here, we do so, truly, in no hypercritical spirit.

Analytically considered, the subject matter of Dr. Bovell's work, as there discussed, involves two distinct principles: the proofs of a great First Cause or Creator, and the exposition of Divine. goodness and wisdom as shewn in natural objects and phenomena; and secondly, the reconciliation of geological discoveries with the statements of the Mosaic Record. Under the first division of his subject, the author refutes, with great force and skill, many of the pantheistic and other prevalent doctrines of a cognate character, that have been put forth more or less openly of late years, not only in continental Europe, but by names of distinction also in British science. The passages in which these doctrines are thus discussed, will well repay the reader's perusal. We would willingly have quoted

from them; but the necessary extracts-due regard being had to the continuity of the argument-would be too copious for our pages; and hence, in justice to the author, we must refer the reader to the work itself. It is in this part of his treatise more especially, that the varied knowledge, eloquence, and acumen of our author are brought fully into play. We do not think he is so happy in the more purely geological portion of his book. It is to some extent a matter of opinion, but we fear he will find few geologists at the present day willing to subscribe to his interpretation of the Mosaic Record as given in the pages before us. Following Buckland, more particularly, Dr. Bovell interprets the word DAY in its literal sense, and looks consequently on the narrative of Moses as taking up the history of the world's creation, not from the Beginning-beyond the mere allusion to a beginning in the first verse of Genesis-but from the commencement of the present, or, what we may call, the Human Epoch. No reference, it is assumed, is made in the sacred record to the earlier creations of the globe, but those types alone are spoken of, which immediately preceded man's advent upon the scene, and which formed the parent-stocks of the fauna and flora that now people the earth and its waters. So far, perhaps, so well. But the holy writings record distinctly the elaboration of the world, or (according to those who adopt Buckland's theory) its regeneration, from a void or chaotic condition: and have we in the later periods of geological history any proofs of the existence of such a state? Dr. Bovell replies in the affirmative, and points to the so-called “Glacial Epoch" which marks according to his view the close of the great Tertiary age. But this is the weak point in his argument. It is a position indeed, perfectly untenable. The Glacial epoch, far from marking the close of the Tertiary age, belongs rather to the present, or forms a complete period of passage between the two epochs. Between the Tertiary Age and the Glacial Period it is absolutely impossible to draw a strict line of demarcation; and still less are we able to draw one between the latter and the existing era. Many types, both animal and vegetable, have survived the glacial epoch; and (as so ably pointed out by Edward Forbes) it is evidently to the agency of this glacial period, as it came gradually on and gradually diminished in intensity, that the isolation of many arctic plantcolonies is due. That the Alpine plants of the Pyrennees and Scotland, for example, isolated from the surrounding vegetation, find their kindred species amongst the flora of northern Scandinavia,-that

the Alpine plants of the United States are related specifically to the flora of Labrador-depends evidently, (unless we adopt the theory of centres of creation) on a southern migration of these forms during the gradual development of this period of cold, and on their subsequent destruction in intervening districts, as the glacial forces slowly dwindled back to within their present limits. It must not be forgotten, moreover, that the results of glacial disturbance, were apparently confined to northern and extreme southern latitudes, in place of being of universal manifestation. Within the tropics for example, our true Drift deposits-the accumulations of glacial agencies on submerged areas are properly unknown. This fact alone, consequently, points to a very different condition of things from that indicated by the language of the sacred record. Nor can the comparatively modern uprise of large areas in South America and elsewhere, help to sustain our author's opinion; because these elevated tracts are the results of forces really still in action, and afford nowhere the slightest indication of the former existence of one grand and vast convulsion affecting equally the whole globe.

We need not carry our analysis farther; but it would be easy to shew that if we took the close of any geological period as our starting point so far as it is possible to determine this-equal difficulties would beset the literal interpretation of the Mosaic day. But truly --and the fact becomes more and more apparent as work after work, like that now under notice, becomes added to our stock-human science as yet is all too unprepared to undertake the investigation of these grave and apparently impenetrable mysteries. Whilst thus compelled, however, to dissent from the views of our author, as expressed in this portion of his work, we may fairly add our testimony to the general value of the work itself. As a treatise of undoubted merit, and as a home product both of pen and press, it well deserves the attention of all interested in the progress of Canadian literature.

E. J. C.

BOOK RECEIVED:-A Course of Practical Chemistry. By Henry Croft, F.C.S., etc. Toronto: Maclear and Co, 1860.

Want of space compels us to postpone our notice of Professor Croft's useful Handbook of Analytical Chemistry, just published by Maclear and Co, until the next issue of the Journal; but, in the mean time, we may recommend it as being especially adapted to the requirements of our Medical and University students.

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