Ch. VI.] VOLCANIC TUFFS AND PEPERINOS. 71 



been contorted and shivered into an immense number of frag- 

 ments. 



We have stated that the beds of limestone, clay, and sand, 

 in the Val di Noto, are often partially intermixed with volcanic 

 ejections, such as may have been showered down into the sea 

 during eruptions, or may have been swept by rivers from the 

 land. When the volcanic matter predominates, these com- 

 pound rocks constitute the peperinos of the Italian minera- 

 logists, some of which are highly calcareous, full of shells, and 

 extremely hard, being capable of a high polish like marble. 

 In some parts of the Val di Noto they are variously mottled 

 with spots of red and yellow, and contain small angular frag- 

 ments, similar to the lapilli thrown from volcanos. 



It is recorded that, during the late eruption off the southern 

 coast of Sicily, opposite Sciacca, the sea was in a state of violent 

 ebullition, and filled, for several weeks continuously, with red 

 or chocolate-coloured mud, consisting of finely-comminuted 

 scoriae. During this period, it is clear that the waves and cur- 

 rents that have since had power to sweep away the island, and 

 disperse its materials far and wide over the bed of the sea, must 

 with still greater ease have carried to vast distances the fine red 

 mud, which was seen boiling up from the bottom, so that it may 

 have entered largely into the composition of modern peperinos. 



Professor Hoffmann relates that, during the eruption (June, 

 1831), the surface of the sea was strewed over, at the distance 

 of thirty miles from the new volcano, with so dense a covering 

 of scoriae, that the fishermen were obliged to part it with their 

 oars, in order to propel their boats through the water. It is, 

 therefore, quite consistent with analogy, that we should find 

 the ancient tuffs and peperinos so much more generally dis- 

 tributed than the submarine lavas. 



In the road which leads from Palagonia to Lago Naftia, and 

 at the distance of about a mile and a half from the former 

 place, there is a small pass where the hills, on both sides, consist 

 of a calcareous grit, intermixed with some grains of volcanic 

 sand. 



