and Vegetation of Sicily. 1 13 



of Catania, but are seen again north of that district, near 

 Catania and a few other places, where the rock has escaped 

 the lavas of Etna. These beds may be traced uninterruptedly 

 from Terra Nuova to Cape Passaro ; they consist either of a 

 soft earthy limestone, generally of a straw colour, which in some 

 of its varieties resembles the beds occurring in the oolite of 

 England, or of a breccia, in which nodules of a more compact 

 limestone are embedded in the earthy basis before described. 

 At Cape Passaro the fundamental rock is a volcanic tuffj 

 covered towards the summit of the cliff by a bed of a more 

 crystalline and compact limestone, containing numerous or- 

 ganic remains. 



Two or three alternations of the volcanic and calcareous 

 strata occur within a few miles of the Cape. From hence for 

 thirty miles northwards, the limestone rocks continue without 

 interruption; but the most numerous alternations are seen 

 between Monte Vennera and Lentini. 



On Mount Etna itself, it will be unnecessary to make any 

 observations, therefore I will conclude with the opinion of 

 Professor Daubeny, that " the volcanic rocks of Sicily are of 

 two epochs at least, namely, antediluvian^ which alternate with 

 calcareous rocks, and postdiluvian, which comprise the greater 

 part of the lavas that have flowed, at different times, from 

 Mount Etna. It is probable that this mountain was burning 

 at a period antecedent to the time of Homer ; and there are 

 volcanic rocks at its foot, which seem to have been produced 

 before the commencement of the present order of things." 



The following extract from the accurate Memoir of Sicily, 

 by Capt. W. H. Smyth, R. N., will point out the localities of 

 the principal Sicilian minerals : — " Masses of Pozzalana occur 

 at Lentini, Vizzini, Palazzuolo, and Palica ; and various sub- 

 stances, that have also evidently undergone the action of fire, 

 are observable in several parts of the interior, where the super- 

 incumbent strata have been riven by torrents. The central 

 divisions of the island contain large tracts of bitumen ; and, 

 though sulphur is rather a cause than a product of volcanoes, 

 it may be noticed that it is found in immense quantities at 

 Mussumeli, Cattolica, Girgenti, Naro, Mazzarino, and Alicata. 

 In the neighbourhood of Regalmuto, Fiume di Nisi, Caccamo, 

 Savoca, and San-Giuseppe, are found silver, lead, copper, 

 cinnabar, marcasite, emery, and antimony. Auriferous pyrites, 

 lapis lazuli, mercury, alum, and coal similar to that from 

 Bovey in Devonshire, abound in the hills and valleys of 

 Nicosia, Ali, Tortorici, and Messina. 



" Rock-salt, bitumen, and gypsum, particularly the latter, 

 abound at Castro-Giovanni, Mistretta, Caltanisetta, Ragusa, 



Vol. III. — No. 12. i 



