Geological Society. 57 



Nov. 30. — A paper " On the Geology of the Southern Provinces 

 of Spain," by Capt. Edward Cook, R.N. F.G.S., was begun ; and a 

 communication containing extracts from the memoirs published by 

 M. de Buch in the Preussische Slants Zeitung, " On the new volcanic 

 island in the Mediterranean, and its connection with the extinct 

 volcanic island of Pantellaria, and the hot springs of Sciacca on 

 the coast of Sicily," by Leonard Horner, Esq. V.P.G.S. and ad- 

 dressed to the President, was read. 



About twenty-four miles S.E. from the point where Sicily and 

 Africa lie nearest together, is the small island of Pantellaria, almost 

 halfway between the two coasts, but rather nearer Africa. It is 

 of an oval form, about fourteen miles long from N.W. to S.E., and 

 rather more than seven broad. It is under the Sicilian Government, 

 is very fertile, and contains about 7000 inhabitants. 



The island is entirely volcanic, and there are three distinct 

 points of eruption, from which the materials have been supplied. 

 The external border is formed almost wholly of a succession of 

 numerous beds of a peculiar kind of trachytic lava of a light 

 greenish-gray colour, and resembling gneiss in its granular, slaty 

 structure. Within this encircling border there rises, as from the 

 bottom of a vast crater, the principal mountain mass of the island, 

 the summit of which is 2000 feet high, composed of pumice and 

 numerous lava streams which have issued from the flanks. From 

 every part of the sides of the mountain aqueous vapour issues, and 

 copious hot springs are found at its foot, which are accumulated in 

 a warm lake of salt-water 6000 feet in circumference. 



About seventy miles north-east of Pantellaria lies Sciacca, on the 

 Sicilian coast, where hot sulphureous springs issue continually from 

 fissured limestone, indicating a seat of volcanic action ; although no 

 rocks of igneous origin are found there. Between this point and 

 Pantellaria there are many shoals in the Mediterranean, and on one 

 of these the new island arose in July last, which had been an- 

 nounced by the shocks of earthquakes at Sciacca on the 28th of 

 June. This volcano was seen in eruption by the Captain of a 

 Sicilian ship, who found the sea around the volcano, and at the di- 

 stance of eight miles from it, covered with dead and half-killed fish. 

 On the 12th of July, floating cinders were lound in such quantity 

 near the coast of Sciacca, thirty-seven miles distant from the spot, 

 that fishermen were obliged to cut a way through them with their 

 oars. They found at the same time newly killed fish on the sur- 

 face of the water, which they sold in Sciacca. M. Hoffmann and 

 his travelling companions visited the volcanic island on the 24th of 

 July, when it was 60 feet high and 800 in its greatest diameter. 

 Cinders and ashes were then ejected, and a column of white smoke 

 rose to the height of 2000 feet. 



Two months afterwards the Prussian geologist and his com- 

 panions paid a second visit to the island, which he then found 

 about seventy feet high. The sea had broken down the black wall 

 of sand in many places, and had formed a kind of moving reef of sand 

 and mud, which made it impossible to land. Large masses were 



N.S. Vol. 11 . No. 61. Jati. 1832. I <«"'ng 



