The above list contains the whole genera of fossil animals yet discovered; and the number of species may amount to about seventy. It will be observed, that the greater proportion of species belong to the order Pachydermata, or thick-skinned animals, and consist chiefly of those that are aquatic, or that frequent the banks of rivers. Now, when we consider the nature of the strata of which our present continents are formed, consisting almost exclusively of marine and fluviatile deposits, this is just the sort of terrestrial animals that we might expect to find enveloped in these strata.

In this list, species of the Hippopotamus, horse, beaver, weasel, hare, dog, fox, ox, deer, camel, have been found so nearly resembling living species, as to warrant their being pronounced identical, while others differ only in a slight degree from existing species.

The geographical localities of these fossil remains are here given, which point out a distribution in many cases different from that which prevails at present.

NOTE VI. p. 59.

FORMER TEMPERATURE OF THE EARTH.

After alluding to the theories of central heat and increased volcanic action in former ages, Sir J. Herschel observes, "Neither of these can be regarded as real causes in the sense here intended; for we do not know that the globe has so cooled from fusion, nor are we sure that such supposed superior activity of former than of present volcanoes really did exist. A cause possessing the essential requisites of a vera causa has, however, been brought forward by Mr Lyell, in the varying influence of the distribution of land and sea over the surface of the globe; a change of such distribution in the lapse of ages, by the degradation of the old continents and the elevation of new, being a demonstrated fact, and the

influence of such a change on the climates of particular regions, if not of the whole globe, being a perfectly fair conclusion, from what we know of continental, insular, and oceanic climates, by actual observation. Here, then, we have a cause, at least, on which a philosopher may consent to reason: though whether the changes actually going on are such as to warrant the whole extent of the conclusion, or are even taking place in the right direction, may be considered as undecided till the matter has been more thoroughly examined."-Discourse on the Study of Natural Philosophy.

The distribution of heat on the surface of the globe, and the modifications of climate as influenced by the excess or deficiency of land, is a subject full of interest, and has been beautifully illustrated by Humboldt, in his remarks on Isothermal lines. (For a summary of his treatise see Edinburgh Philosophical Journal, vol. iii. 1820.) Without a knowledge of this subject, the true import of Mr Lyell's theory of change of temperature cannot be sufficiently appreciated.

NOTE VII. p. 61.

Those geologists who believe in the existence of a previous world reckon all the strata below the superficial diluvium as belonging to this ancient state of things, and that the creation of the present earth and present system of things commences with the soil and vegetation above this diluvium, the effects of the deluge being supposed to have been of a slight and transient nature, and to have left no proofs behind. Professors Buckland and Sedgewick, the Rev. Mr Conybeare, and many others, avow this opinion.

Cuvier believed the present system of things to have commenced immediately after the deluge, when the present surface was elevated above the level of the ocean.

A third party ascribe no definite period to the com

mencement of the present system, but allow that man was introduced upon the earth at the period indicated by historical record. Hutton, Playfair, and Lyell, adopt this opinion.

NOTE VIII. p. 64.

The effect of rivers wearing down their channels we have remarked in several of the waterfalls in Scotland, particularly at the Cauldron Linn, or waterfall on the Devon, in Clackmannanshire, where there is a sinking of the fall of ten feet through a chasm worn in the hard greenstone rocks. The gradual progressing of the fall of the mighty Niagara upwards to its source in lake Erie, is also well exhibited in the frontispiece to Bakewell's Elements of Geology, 4th edition. From this sketch it appears that the river Niagara, which flows out of lake Erie, has, in the course of ages formed a deep channel, of seven miles in length, from the present falls to Queenstoun, and that the cataract has, in all probability, been situated at this lower point when it first began to flow, but that it is now progressively wearing upwards. Mr Fairholm has also some interesting calculations on the probable time which has been necessary for the river to excavate this course.

NOTE IX.

p. 75.

FABER'S EXPLANATION OF THE MOSAIC DAYS.

"The divine Sabbath, instead of being limited to a single natural day, is, in truth, a period commensurate with the duration of the created universe. What that duration will be, no one knows, save the Father only, (Mat. xxiv. 36;) but this we know, that according to the

Hebrew chronology, the world has already existed nearly six thousand years, and that according to the Samaritan chronology, it has existed longer than six thousand years. The divine Sabbath, therefore, is a period of not less duration than six millenaries. But an analogy of language requires us to interpret homogeneously the seven days which constitute the great week of God. Hence, as the seventh day is a period of not less duration than six millenaries, each of the six days must, similarly and proportionately, have been equivalent to a period equalling or exceeding six thousand years. this great work, our minor week is a commensurative epitome. Our six days of labour correspond to the six periods of God's labour, and our sabbatical day shadows out the sabbatical period during which the Almighty has rested from all his work which he had made.

Of

"The first day, or first six thousand years, was engaged in the separation of light from darkness, and of the elements of fire from the crude aqueous matter which constituted the primeval chaos. The second day, or second six thousand years, was employed in disengaging the elements of air from the same discordant mass, when a separation of the waters immediately and necessarily took place. The third day, or third six thousand years, was employed in the separation of the lower water from the element of earth, and in the production of vegetables. The fourth day, or fourth six thousand years, was engaged in forming and placing in the material heavens the sun, and moon, and stars. The fifth day, or fifth six thousand years, was engaged in a twofold work-in the earlier part, the waters brought forth fishes; during the latter part, they produced birds. Several great mundane revolutions must have taken place ere the commencement of the sixth day, and, therefore, in the course of the third, and fourth, and fifth days. The sixth day, or sixth six thousand years, was employed in the formation, first of beasts and reptiles, and lastly of man. The seventh day, or actual series of six thousand years, more

or less, gives the analogical rule or measure of each of the preceding."-FABER on the Three Dispensations.

Is it not singular to think that an acute and able mind should waste its efforts in such purely fanciful speculations?

DR CHALMERS' OPINION.

Dr Chalmers was so kind as to direct my attention to a review of Cuvier's Theory of the Earth, which appeared in the Christian Instructor for April, 1814, from which I have here taken the liberty of inserting several extracts, as containing the opinion of this celebrated divine on the authenticity of the Mosaic narrative.

"The strength of the Christian argument has never been brought fairly into contest with the speculations of geology. These speculations are almost entirely constructed upon presently existing appearances; for they are but very slightly modified by the very slender materials which have come down to us in the records of past times. Let us suppose that a very ancient record of geological facts were discovered, with the most conclusive marks of authenticity upon it, and that it gave the lie to the most popular and accepted theory of the day. The circumstance of that theory, being the most probable of all those which had been started upon the facts within our reach, would not be suffered for a moment to exclude the new information which had broke in upon us. It were a sad transgression upon the inductive philosophy to refuse this information, with not another reason to set it aside, than that it is inconsistent with our theory. The information must be received, if it has enough of its own appropriate evidence to make it credible, even the evidence of history. A man of true philosophical habits would be thankful for it, and if a theory must be got up, he would accommodate it to the wider field of induction which lay before him.