Gemellaro, Giuseppe, 18 " Mario, 19 " Carlo, 19, 20 General aspect of Etna, 34 _Genista Etnensis_, 45 Geological Maps of Etna, 117-18 Gibel Uttamat, 3 Gladstone's Account of Eruption, 58 Gravity, Specific, of Ejectamenta, 130 Great Crater, 57, 58 Grotto of Polyphemus, 75 " delle Palombe, 37 Growth of a Volcano, 123 Gurrita, Lake, 68 Hamilton, 14 Height of Etna, 26, 27 Hephaistos, Forge of, 4 Himilco, 81 Hoffmann, 22 Homer, 4 Houel, 14 Hybla Major, 63 Increase of Population, 33 Inessa, City of, 64 Inglesi, Casa, 51, 52 Inns, Sicilian, 65, 67, 69 Iron, Nitride of, 134 " Perchloride of, 132 Iron, Titaniferous, 127 Isola d'Aci, 75 Katana, 76, 77 Kircher, 12 Labradorite, Analysis of, 125, 126 La Cisterna, 101 Latitude of Crater, 2 La Scaletta, 75 Lava, Analysis of, 131, 132 " Specific Gravity of, 130 " Decomposed, Analysis of, 133 Lavas, Microscopic Analysis of, 135-141 Lavas of Etna, 125-141 Linguaglossa, 70 Longitude of Crater, 2 Lucilius Junior, 7-9 Lucretius, 6 Lyell, 23 Lyell's Researches, 118-122 Magnetite, 139 Maletto, 68 Maps, Geological, of Etna, 117, 118 " of Etna, 13, 16, 21-24 Mascali, 71 Microscopic Analysis of Lavas, 135-141 Milo, 108 Mineral Oil in Lava, 129 Minor Cones, 34-36 Mongibello, 3 " Axis of, 122 Monte Calanna, 107 " Capreolo, 118 " di Mojo, 36,81 " Minardo, 34 " Ste. Sofia, 36 " Fusara, 37 " Grigio, 111 " Lepre, 85 " Nocilla, 118 " Rosso, 99 " Spagnuolo, 69 " Ste. Sofia, 95 Monti Rossi, 35, 91 Mules, 47 Name of Etna, 3 Natural Boundaries of Etna, 30 Naxos, 81 Newer Pliocene Strata, 120 Nicolosi, 46 Nitride of Iron, 134 Observatory on Etna, 50 Oil, Mineral, in Lava, 129 Olivine, 139 " Analysis of, 127 Palombe, Grotto delle, 37 Paterno, 63 Pennisi, Baron, 71, 72 Piano del Lago, 51 " di S. Leo, 90 Piedimontana, Regione, 37, 38 Pii Fratres, 80, 81 Pindar, 4 Polarized Light, applied to Analysis of Lavas, 136-139 Polyphemus, Grotto of, 75 Population, 31-33 Position of Etna, 2 Presl's _Flora Sicula_, 41, 42 Radius of Vision, 28 Randazzo, 68, 69 Recupero, 17 Recupero's Account of Eruption, 99 Refraction, Effects of, 59, 60 Regions of Etna, 37-42 Regione del Fuoco, 37 River, Acis, 73 Road around Etna, 29 Rocca di Musarra, 98 Rocks of Cyclops, 75 Rutley's, Mr. Frank, Analysis of Lavas, 135-141