Letter to Sir Charles Lyell from Carlo Gemmellaro in answer to a previous letter sent by Lyell. He apologises for not being able to answer Lyell's questions as he has been ill and promises that he will return to Aci to try to detect Wolfgang Sartorius Von Waltershausen's mistakes as to what Mercurio says on the eruption of 1852. He mentions carboniferous soil in Sicily, local units of measurement and lava flow on the island. He also thanks Lyell for sending a printed abstract of the proceedings of the Geological Society which features his son, Gaetano Gemmellaro, 25 March 1858.