already described*, Saussure observed rocks of grey marble, and fragments of slate.

1806.

Such are some of the most remarkable exam- Rosenberg, ples of this phenomenon. In 1806, the mountain of Rosberg, or Rosenberg, near the town of Arth, fell down, and buried a considerable tract of country, with some inhabitants. A detailed account of this event was published at Paris, with three plates, representing, 1. the town of Arth, the neighbouring country, and the profile of the ruin; 2. the same scene in front, with the extent of the fall; 3. the lake and tower of Lawerts, with Roggiberg and Rosenbergt.

Dom. II. Mode xiv.

+ Derniere relation du triste désastre, causé par l'eboulement d'une partie du Roggiberg, et du Rosberg; de trente pages d'etendue, accompagnée de trois gravures, proprement terminées en noir, de 10 pouces de haut, sur 15 de large. Chez Villequin, march. d'estampes, grande cour du Tribunat, No. 20. 9 fr.

La premiere represente le beau bourg d'Arth, les campagnes qui l'avoisinent, et le profil du l'eboulement: La seconde, l'immense cutafalque, et triste tombeau, d'une partie des habitans, de la vallée dArth, et l'eboulement vu de face. La troisieme, le lac et la tour de Lawerts, le Roggiberg, et le Rosberg.

Volcanoes

numerous.

THE volcanic rocks may be said, with the German mineralogists, to be of the most modern formation, as every new eruption of about one hundred and fifty volcanoes scattered over the face of the globe, must produce new rocks of this description. That there are also volcanoes at the bottom

of the sea, we know, from the ejection of new islands in the seas of Greece; and in the Atlantic near Iceland, and the Azores. It may therefore be considered as a most rational conclusion, that, as the ocean occupies two-thirds of this globe, numerous volcanoes may exist at such depths, that their effects are wholly unperceivable. Dolomieu seems to have demonstrated that Depth of fuel the matter, which supplies the prodigious eruptions of volcanoes, must lie at an immense depth beneath the crust of the earth. This position may be argued, 1. from the surprising extent of earthquakes, felt from Lisbon to Scotland, a space of 15 degrees, or about 1000 British miles. 2. From the prodigious quantity of matter ejected in the course of ages; from the comparatively small craters of Etna, for example, whole mountains, nay territories have issued; which, if drawn from a space near the surface, the mountain must long since have sunk into its own abysses. 3. From the nature of the lava, which, in some instances, has burst through the superincum

Candour necessary.

Many extinct.

bent masses of granite, itself regarded as the fundamental rock.

As it is foreign to the nature of this work to examine with much attention the theories of volcanoes, it shall only be observed that the French authors, in treating the origin of basaltin and amygdalite, seem to be rather too much attached to the volcanic influence; yet we, on the other hand, seem to be too violently prejudiced against the admission of that influence.

Prejudice, on either side, is not only ridiculous, as the subject is of no importance to human life or happiness, but as a direct contradiction to the very spirit and nature of philosophy, which ought to examine any topic with complete candour and impartiality; nay, a writer who means sincerely to serve the sacred cause of truth, which must in the end ever be victorious, would rather, for a season, support an opinion the most opposite to prejudice, that the light may as usual be struck out by the collision of contending powers.

When we consider the great number of

volcanoes that are still active on that third part of our planet which consists of land, is it not most rational to suppose that many may have become extinct? Strabo informs us, that Vesuvius had been a volcano at a remote period; while its first eruption is commonly ascribed to the reign of Titus, near a century after the time of that author. The volcanoes of Auvergne 'seem to have been relumed for a short period, in the time of Sidonius Apollinaris, whose culmina can scarcely be applied except to the summits of mountains; for the tops of

* Lib. v. This remarkable passage may be thus translated:

"Here arises the mountain of Vesuvius, inhabited through all its delicious fields, the summit alone excepted, which spreads into a barren plain, displaying ashes and deep caverns formed of burnt rock, as the colour indicates, and abrasions by fire; whence it may be conjectured that this mountain was formerly in a state of efflagration and presented fiery craters, which became extinguished when the materials were exhausted." He proceeds to state, that the fields near Etna were equally fertile. The streets of Herculaneum were paved with lava.

See also, Strabo, lib. i. p. 158. edit. Siebenkees, for a volcano, soon extinct, near Methone, which ejected a hill near a mile in height, and rocks like towers.

Pindar describes Etna, which is unmentioned by Homer, a proof that his geographical knowledge did not extend as far as Sicily, and that the received interpretations are false.