The Daily Cincinnati Republican, And Commercial Register

PROFESSOR SILLIMAN.

Professor Silliman has been giving a popular and very interesting course of lectures on Geology, at Boston. His competency to that task no one can question; but it is not every one who possesses, as he does, sufficient taste and literary qualifications to make a scientific subject fascinating to a popular audience. Speaking of volcanoes, the Professor stated some striking facts:

He spoke of the earthquake at Caraccas, and on the recent eruption in the bay of Honduras—of the mountains of Quito, and the whole chain of the Andes, which are capped with porphyry, trap and basalt, and supposed that there was no doubt that the whole range, from Terra del Fuego, or Land of Fire, was a continued range of volcanoes. He then alluded to the islands in the Pacific, all of which are volcanic, the bed of that vast ocean probably resting on arches of fire; the volcanoes being merely the chimneys, or the place of exit, for the fire and smoke in the interior of the earth. The number of volcanoes known to be in actual existence is upwards of three hundred! In Mexico, in 1759, a region of country, upwards of seventy miles in extent, rose by volcanic action, several hundred feet, and a mountain was formed in the centre of about 1700 feet in height—which, fifty years afterwards, when Humboldt visited the spot, was found to be hot and smoking.

The surface of the earth therefore is nothing but a crust of frozen lava! The earth was probably a red hot ball: the surface of which is now congealed. Its figure that of an oblate spheroid shows that it was of a nature soft and yielding. That the sun is now a red hot ball, and the dark spots on its surface may be the commencement of congelation. In the course of time, the whole surface may become congealed, and the earth will thus be deprived of the source of light and heat!