218 Dr. Cooper on Volcanoes 
at Lisbon, Europe, Africa and America, were for some 
time repeatedly agitated by subterranean explosions. tna, 
which had been in a state of profound repose for eighty 
years, broke out with great activity. In 1812, the earth- 
quake of the Caraccas, was followed by the volcanic erup- 
tion of St. Vincents, before mentioned, in thirty-five days. 
Humb. per. narr. ii. 226. 
Many clear and indubitable volcanoes once in action are 
extinct. There are eleven in Rome and the Campagna of 
Rome, according to Dr. Sicklu’s topographical view of that 
district, viz. solfaterra. Lake Gabinus, Regillus, Albanus, Ne- 
morensis, near to Ariccia, Juterna, Castello Gandolfo, Nemi, 
San Juliano, Baccono, Brecciano, Lago Morte, Anagni: 
Breislak counted thirty-five extinct voleanoes in the space 
of five or six leagues by two leagues, about Naples. ‘The 
Lava appears to be from one hundred to one hundred fifty 
feet deep, as appears in digging wells ; in which case the 
workmen have to dig that depth before they come to the 
newest or most recent Lava. Rocca di papa two thousand 
six hundred feet high is voleanic, so are the ‘hills about 
Frescati and Albano. There is a space of near six hundred 
square leagues about Rome, covered with Lava of various 
kinds. The ancient voleanoes of Sicily, extend from Cape 
Paclino to Atna, and are covered by, and alternate with, 
shell Limestone : hence they were submarine. ‘To the 
same purpose Mr. Leckie in Bakewell 216, 2d Ed. This 
alternation of submarine volcanic ejections with limestone of 
marine origin is noticed by our own mineralogist Mr. W. 
M’Clure, in his account of the West-India Islands : the facts 
are so curious, that I shall copy them from the trans. of the 
Philadelphia Academy of Sciences, p. 142 at seq. 
Dominica. A bed of coral or Madrepore Limestone with 
shells, lies horizontally on a bed of cinders, about two” or 
three hundred feet above the level of the seas at Rousseau, 
and is covered by cinders to a considerable height. 
St. Christophers. p..147. Brimstone hill is a’ stratifica- 
tion of Madrepore limestone with shells, at an angle of up- 
wards of 50° from the horizon, reposing on a bed of volean- 
ie cinders, and partly covered by volcanic irruptions, ma- 
king a fine specimen of the alternation of the Neptunian and 
volcanic formations, which for aught we know, may be re- 
peated twenty or thirty times in the foundation of these 
