Dr Woodward, a physician, also flourished in this period. His practical knowledge of the British strata was considerable; and he made a large collection of fossils, which he arranged systematically, and bequeathed to the University of Cambridge. His geological theories, however, were fanciful, and not at all founded on his practical knowledge. He supposed that the whole strata of the globe were broken down, and reconstructed at the period of the deluge.

Whiston was another cosmogonist of the same school. He attributed the deluge to the contact of a comet with the earth; and was amongst the first who began to tamper with the text of Genesis, and bend its meaning, by means of verbal criticisms, to his own purposes.

Dr Burnet published his Theory of the Earth between 1680 and 1690. He seems to have altogether disregarded practical facts and inductions, and to have given a loose rein to his imagination. His style is glowing and energetic, and his book may be read as a poetic declamation, but it is in all other respects utterly unprofitable. Yet it was highly relished by his contemporaries, passed through several editions, and was a great favourite with Charles II.

the sun and stars, and the whole heavens, shall be annihilated, together with the earth, at the era of the grand conflagration.”. Elements of Geol. vol. i. pp. 57, 8.

About the beginning of the eighteenth century, geological theories and facts were still farther prosecuted by Vallisneri Lazzaro Moro, and his eloquent commentator, Generelli. The latter describes the waste of the surface of the earth continually taking place, and concludes that this loss and decay must be compensated by elevating volcanic forces.

On a review of the writings of the early geologists, then, it appears, that amid much that is fanciful, and amid many erroneous deductions, drawn from scanty or misconceived facts, still the germs, and, in some instances, the complete development of modern theories are distinctly to be traced.*

*

For a full historical view of the early geologists, the reader is referred to Mr Conybeare's Introduction to the Geology of England and Wales, and to Mr Lyell's Elements, vol. i.

135

SECTION II.

LATER GEOLOGICAL THEORIES.

IN 1749, Buffon published his System of Natural History, the preliminary part of which is devoted to a theory of the formation of the earth. Though an eloquent and highly popular author, his cosmogony can lay no high claims to originality of conception, nor was it based on any comprehensive knowledge of the facts even of his predecessors. In general, he adopts the theory of Leibnitz. His supposition that the earth was a portion of the sun, struck off in a fused mass by the stroke of a comet, has been pronounced, by competent astronomers, as inconsistent with the known laws of projectiles; for if such a mass had been thus struck off from an attracting centre, it would again have returned into the sun, after a brief journey in space. His ideas regarding the permanent horizontality of the fossiliferous strata since the period of their formation, are inconsistent with facts; and the only valuable part of his geology, in a practical view, is his

account of the physical changes taking place on the earth's surface.

In 1757, Gesner, the naturalist of Zurich, published a work on fossil remains, with an account of the changes on the earth's surface which they elucidate. And a few years afterwards, a treatise appeared in the Philosophical Transactions, by Professor Mitchell of Cambridge, illustrative of the effects of earthquakes in elevating and producing disturbances on the various contiguous strata, and especially applied these principles to the older formations of Yorkshire.

Geological phenomena were farther elucidated about this period by the travels of Targioni in Tuscany, of Pallas in Russia, who particularly mentions the fossil skeleton of a rhinoceros, and other bones found in Siberia, and of Saussure, who made many valuable remarks on the structure of the Alps.

WERNER. This celebrated mineralogist and geologist was appointed professor of the school of Mines at Freyburg, in Saxony, in the year 1775. He was a man of varied information, of lively fancy, eloquent and enthusiastic, and had the rare talent of gaining over his pupils to an implicit and exclusive belief in his system. He had never travelled, but drew his conclusions from the partial strata in his immediate neighbourhood, and but too hastily

concluded that these represented the whole of the earth's surface. The leading points of his geology may be expressed in a few words. He supposed the earth was originally completely surrounded with an ocean or primordeal fluid, which held in chemical solution the whole materials of the subsequent strata of the globe. That these materials were precipitated at successive epochs, beginning with the lowest primary rocks, which were deposited before the existence of plants or animals, and ascending gradually to the newest formations, which were successively furnished with their peculiar organic remains. He supposed that the earth had suffered several convulsions, or rather inundations of the oceanic fluid, and at a particular period had undergone a great change in passing from its inorganic to its organized condition. This he termed the transition period, indicated by the peculiar greywacke rocks, which still retain this general denomination. He allowed of no igneous action except in modern volcanoes, the existence of which he could not well get quit of. Even the basalts and greenstone rocks were with him crystallizations from a chemical fluid, and entire mountains were looked on, in many cases, as one great central crystal. He believed in epochs of indefinite duration; and his physico-theological followers, such as De Luc and Kirwan, readily had recourse to the elongation cf the Mosaical day, in order to render their specula