As the island of Ventotiene connects this group of the pumice islands with the continent of Missene, that of Zanone, on the other side, connects them with the continent at mount Circello.  Here is a fact of which our author now gives proper evidence.

It would appear that Mount Circello is composed of an alpine limestone.  But in the north end of the island of Zanone, the Chevalier de Dolomieu finds a small part of a similar limestone in vertical strata, closely united with the volcanic materials of the islands now under consideration.  It is impossible that this portion of calcareous rock could be formed in its present situation, and we have but to examine nature in order to be convinced that this limestone part had been once continued from Mount Circello.  Here again I beg leave to give this author’s own words, (page 141.)

“Cette reunion de deux matieres aussi differentes par leur origine que le font celles qui forment l’Isle Zanone, est une circonstance des plus singuliers.  La pierre calcaire ne contient point de coquillages; sa densite sa durete; son odeur fetide annonce une origine ancienne; elle n’est point formee par un depot de nouvelle date; elle differe des pierres calcaires-coquilliere qui recouvrent les volcans du Padouan et du Vicentin, et de celles qui se sont meles avec les produits du feu dans les volcans eteintes de la Sicile:  les laves ici reposent sur elle:  elle paroit donc anterieure a l’epoque des irruptions qui ont eleve les isles ponces.  Par sa nature elle est semblable aux pierres du Mont Circe, et a celles de l’interieure de l’Apennin; il semble que cette portion de montagne calcaire, abstraction faite des matieres volcaniques qui lui sont reunies, a appartenu a quelqu’unes des montagnes qui dependent de la chaine qui traverse l’Italie; car il n’est pas possible que ni elle ni le Mont Circe ayent ete formes seules et isoles ainsi que nous les voyons.  Mais quand ont-ils ete detachees? etoient-ils deja isoles lorsque les feux ont commence la formation des isles ponces? ou seroit-ce la meme revolution qui les auroit separes du continent, et qui a opere le desordre que nous voyons dans ces isles volcanique?  On ne peut former sur toutes ces questions que des conjectures bien vagues.”

Our present inquiry is only with regard to the operation of those causes which we now perceive to be acting upon the coasts of the land; which must be considered as having been operating for a long time back, and which must be considered as continuing to operate.  One example more I wish to give, not only as it is much to the purpose, and properly described, but because it contains the natural history of a coast well known from the circumstance of the Giant’s Causeway which it contains; a coast composed of stratified chalk indurated and consolidated to a species of marble or lime-stone, and of great masses of basaltes or columnar whin-stone.  Now, though our present object is not the formation of land, yet, knowing the mineral constitution of this land, the coast of which we are considering as having been worn by the action of the sea, the view here to be given, of the white marble and basaltic cliffs, is satisfactory in the highest degree.  It is from Letters concerning the Northern Coast of the County of Antrim, by the Reverend William Hamilton, A. M.