some recent instances their power must have been tremendous. In South America, so lately as 1822, an area of 100,000 square miles, which is equal in extent to the half of France, was raised several feet above its present level—a most able account of which is given in the ‘Transactions of the Geological Society,’ by an esteemed friend of the author’s, the late Mrs. Graham, who was present during the whole time of that formidable earthquake, which recurred at short intervals for more than two months, and who possessed talents to appreciate, and had opportunities of observing, its effects under the most favourable circumstances at Valparaiso, and for miles along the coast where it was most intense. A considerable elevation of the land has again taken place along the coast of Chile, in consequence of the violent earthquake which happened on the 20th of February, 1835. In 1819 a ridge of land stretching for 50 miles across the delta of the Indus, 16 feet broad, was raised 10 feet above the plain. The reader is referred to Sir Charles Lyell’s excellent ‘Principles of Geology,’ already mentioned, for most interesting details of the phenomena and extensive effects of volcanoes and earthquakes, too numerous to find a place here. It may however be mentioned that innumerable earthquakes are from time to time shaking the solid crust of the globe, and carrying destruction to distant regions, progressively though slowly accomplishing the great work of change. A most disastrous instance took place on the 15th of December, 1857, in the Neapolitan provinces of La Basilicata and Principato Citeriore, where the destruction was extensive and terrible; the number of victims, according to the official accounts, being returned at upwards of ten thousand. These terrible engines of ruin, fitful and uncertain as they may seem, must, like all durable phenomena, have a law which may in time be discovered by long-continued and accurate observations. The shell of volcanic fire that girds the globe at a small depth below our feet has been attributed to different causes. By some it is supposed to originate in an ocean of incandescent matter, still existing in the central abyss of the earth. Some conceive it to be superficial, and due to chemical action, in strata at no very great depth when compared with the size of the globe. The more so as matter on a most extensive scale is passing from old into new combinations, which, if rapidly effected, are capable of producing the most intense heat. According to others, electricity, which is so universally diffused in all its forms throughout the earth, if not the immediate cause of the volcanic phenomena, at least determines the chemical affinities that produce them. It is clear that a subject so involved in mystery must give rise to much speculation, in which every hypothesis is attended with difficulties that observation alone can remove.