Scope and Contents Letter to Sir Charles Lyell from Carlo Gemmellaro answering a list of questions that Lyell had evidently posed to him in a previous letter. Topics covered include volcanic strata, inaccuracies in maps of the area around Mount Etna drawn by Wolfgang Sartorius Von Waltershausen, and Lyell's theory that the 2 craters of Mount Etna were contemporary. Gemmellaro disputes this theory as each crater ejected different types of rock, Felspatic and Pyroxenic, with no mixing of the two. Gemmellaro...