Material relating to the geology of Mount Vesuvius in Southern Italy and Mount Etna in Sicily as extracted from the letters of Sir Charles Lyell, written during a visit to the area in September and October 1858. He discusses several geological formations in the mountains and occasionally gives sketches to illustrate his points. He also mentions: that he has received a list of shells from the Pliocene clay on which Mount Etna is placed which he hopes will provide a precise paleontological date for volcanos, the heathland on the lower slopes of Mount Etna and heathland plants, that he passed the spot where in 1842 a crowd had gathered to watch a lava flow into a huge artifical reservoir of water. The resulting explosion killed all but around 50 of the crowd, probably by asphyxiation. September and October 1858.