of the globe had undergone from the operation of this agent.

It was at a late period in modern times that speculations as to the origin and structure of the earth were re-introduced. And as Astronomy was preceded by Astrology, so Geology was introduced by Cosmogonythe early geologists being world-builders upon a most splendid scale. I shall only allude briefly to a few of these theories, the most remarkable for their whimsicality, as illustrative of the extraordinary vagaries into which the mind relapses in philosophical speculation, when it forsakes the plain and simple path of induction in order to make phenomena coincide with preconceived ideas.

Burnet, the author of a "Sacred Theory of the Earth," (a work of great merit as a literary composition) which appeared in the sevententh century, conceived that the globe was originally invested with a light crust, which being broken up to produce the deluge, formed the mountains of its fragments.

Woodward, to account for the embedding of marine shells in rocky strata, imagined the principle of cohesion, which holds the particles of matter together, to have been momentarily suspended, which gave rise to the deluge, and permitted the pasty materials which it left to be penetrated with shells.

The boldest idea, perhaps, was that of a philosopher to whom Leicestershire had the honour of giving birth-William Whiston, the learned translator of Josephus. In his "Theory of the Earth" he creates this globe from the atmosphere of a comet, and then most unceremoniously deluges it with the tail of another: and

not content with explaining these great physical events, he thought he had discovered the connection between the physical and moral world, and proposed the solution of an enigma which in all ages had puzzled theologians and divines-the introduction of moral evil into the world. He argued that it was the heat retained in the earth from its origin, that inflamed the unruly passions of mankind, and impelled the whole human race to sin! These were the principles of a man who, only a century ago, occupied the mathematical chair at Cambridge, which had been previously filled by Sir Isaac Newton! It is true that the same restless spirit of speculation led him into heretical notions on the subject of religion, for which he was expelled and persecuted.

Many philosophers, from the great Kepler down to those of recent times have imagined the earth to be possessed of vital faculties, and some have endeavoured to point out the analogy in its constitution with organized beings.

Demaillet, a modern French philosopher of considerable reputation, imagined the whole earth to have been at one period covered with water, in which all the various tribes of living beings had their origin; even man himself, commenced his career as a fish, and had been by degrees transformed into the biped, of which he argued there were unequivocal proofs in the animals inhabiting the ocean (mermaids), which had only undergone half the process of conversion, but which in time would become perfect human beings. His proofs however, required a degree of credulity which his contemporaries were not disposed to give.

Leibnitz, Descartes, and afterwards Buffon, main

tained that the earth was an extinguished star, originally in a state of fusion. Buffon, however, in enlarging upon the idea, which he does most ingeniously, got into hot water with the theologians of the day. It was urged that his theory of the formation of mountains and valleys by the subsidence of the circumfused waters, and the gradual refrigeration of the mass of the earth, was highly reprehensible, as it was contrary to the creed of the church. He was therefore required by the Sorbonne, an inquisitorial assembly of ecclesiastics at Paris, to recant all the notions he had promulgated on the subject, and to append a declaration to the subsequent edition of his works, that he abandoned all that he had said as to the formation of the earth. But as in the case of Galileo, who under similar circumstances abjured his discovery of the motion of the earth upon its axis, the earth still continued to whirl round, so the accuracy of Buffon's conclusions was undisturbed by his recantation-his theory is now in substance generally adopted: and the spirit of enquiry which these bigots would have suppressed, so far from invalidating, has actually thrown light upon the sacred records.

To allude to all the various theories which since this period have been evulgated, would be incompatible with the object and exceed the limits of my sketch: but two eminent characters must not pass unnoticedWerner and Hutton, the champions of the rival elements -fire and water. Werner asserting the supremacy of Neptune, and Hutton that of Pluto, they for a long time divided the scientific world on the comparative merits of their respective systems. They both erred in

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this, the too common error of immature philosophyhasty deduction from limited observation:

"Each claiming truth,

And truth disclaiming both,"

like the dogmatical asserters of the colour of the chameleon, they were both right to a certain extent, as we shall see hereafter that each of the causes for which they contended, have been active in the production of the terrestrial phenomena; but both were wrong in their sweeping generalizations. Their views, moreover, were confined to the mineral structure of rocks-the chemistry of the science; modern geologists have discovered and adopted a less fallible test-the organic contents, a principle which was first recognized and practically applied by Smith,* in the arrangement of the strata and construction of his Geological Map of England, which has attained for him the proud appellation, ceded by universal consent-of "Father of English Geologists."

* At the meeting of the "British Association for the advancement of Science," held at Oxford in 1833, the gold medal reserved for the great luminaries emanating from this seat of education, which dazzle by their learning or benefit by their discoveries, their fellow-men, was awarded by the University, with a liberality that does it honour, to this veteran of geology, who though destitute of the advantages of education, and moving in the humble rank of a land-surveyor, by his own unaided efforts had earned the laurels, which in the presence and amid the plaudits of the illustrious in science from all parts of Europe, were now wreathed upon his silvery hair. A splendid instance of the reward of perseverance, and a powerful stimulus to the exertions of those to whom Nature has imparted a scientific taste, but Fortune has denied her advantages.

*

In tracing the progress of science, it is lamentable to observe the extraordinary ignorance of men whom the world have called great, as to the causes of many natural phenomena, with which we are so familiar. Voltaire, for instance, who has been all but deified by the French, to whose dwelling pilgrimages are performed as to the shrine at Mecca, who presumed to arraign all the existing knowledge upon science, religion, and government, with the most perverse tenacity, insisted that fossil shells found in the earth were lusus naturæ, creations of Nature in her sportive mood-that oyster shells found in high situations on the Jura mountains might have been the scallops worn in the hats of pilgrims, or were probably left there by the Romans, who are known to have had a taste for oysters ;—that vegetable impressions in rocky strata, were not those of real plants; and that the bones of a rein-deer and hippopotamus found in his time near Etampes, proved merely that some lover of curiosities had once preserved them in his cabinet!

Geology, as at present understood, may be said to be a species of history-the physical history of the great globe we inhabit—a sort of antiquarianism which takes cognizance not of ancient coins, broken columns, and antique inscriptions in order to determine the periods and circumstances of revolutions and remarkable eras in human affairs, but investigates the great physical revolutions which our planet has undergone-events of which it finds indelible records, immutable archives, the most infallible testimony, in the monuments and

* Ferney, near Geneva.