Letter to Sir Charles Lyell from Carlo Gemmellaro regarding his volcanic research on Mount Etna. Gemmellaro mentions his respect for the topographical works of Baron Waltershausen but states that the only fault he saw in Waltershausen during his stay in Sicily was the Baron's disregard for the learned Sicilian people. Discusses the geology of Aci Reale, in particular the strata of lava on which the village rests; Baron Waltershausen thought there were only 2 layers, Gemmellaro believes he has proven that there are 7 layers and has drawn a diagram to illustrate. He then describes, with diagram, the lava flow near Aci Reale which entered the sea at S.M. La Scala. He thanks Lyell for his donation towards the repair of the Casa Inglese and remarks that his work on the Volcanology of Aetna is unlikely to be published by the *oenian or *oersian Society until the following year, 08 April 1858.