420. M. De Luc has nevertheless treated very diffusely of the history of the solar system, previous to the establishment of the present laws of nature, and has dwelt on it with great complacency, and singular minuteness of detail. His tenth letter to LA METHERIE has the following title: "On the History of the Earth, from the time when that planet was penetrated by _light_, till the appearance of the sun; a portion of time which includes the origin of heat, and of the figure of the earth; of its primeval strata, of the ancient sea, of our continents, as the bottom of that sea, of the great chains of mountains, and of vegetation."[229] [Footnote 229: Journal de Physique, tom. 37. (1790,) partie 2de, p. 332. As I may not have done justice to this extraordinary title, it may be right to present it in the original. "Sur l'Histoire de la TERRE, depuis que cette planette fut penetrée de LUMIERE, jusqu'à l'apparition du SOLEIL; espace de tems qui renferme les ORIGINES de la _chaleur_, et de la _figure_ de notre globe; de ses _couches primordiales_, de _l'ancienne mer_, de nos _continens_, comme fond de cette mer, de leurs grandes chaînes de _montagnes_, et de la _vegetation_."] I must confess that I am unacquainted with every thing of this letter but the title; and could not easily be prevailed on to follow any man who professedly goes out of nature in search of knowledge; who pretends to give the history of our planetary system when there was no sun, and to enumerate the events which took place between the existence of that luminary, and the existence of light. The absurdity of such an undertaking admits of no apology; and the smile which it might excite, if addressed merely to the fancy, gives place to indignation when it assumes the air of philosophic investigation. 421. It sets, however, in a strong light, the inconsistencies that may be observed in the intellectual character of the same individual, to consider that the author of this strange and inconsistent reverie, is, nevertheless, an excellent observer, and well skilled in experimental inquiries. It will hardly be believed that he who writes the history of the earth before the formation of the sun, is versed in the principles of inductive reasoning; and that he has added much to the stock of geological knowledge, having observed accurately, and described with great perspicuity and candour. His _Lettres Physiques_ are full of valuable and just observations, though accompanied with reasonings that do not seem always entitled to the same praise; and in another work he has succeeded where many men of genius had failed, and has made considerable improvements in a branch of the mathematics, without borrowing almost any assistance from the principles of that science.[230] [Footnote 230: Essai sur les Modifications de l'Atmosphere.]