We have a still more interesting observation made upon this same coast of Italy, by a naturalist to whom the world is much indebted for his excellent remarks upon what he has, by his great industry, brought to light. I mean the Chevalier de Dolomieu; where-ever he goes, natural history reaps the benefit of the most enlightened observations. We are now to avail ourselves of his Memoire sur les Iles Ponces.
The pumice islands form part of a chain of land that may be traced forming a circular line from the cape Missene to the mount Circello at the other side of the Gulf of Gaeta. The islands of Ischia and Procida, which form part of this chain of land, might, from the inspection of the map, be allowed as having once formed a continuation of the land from the continent of Italy, even without the testimony of natural history, that traces this connection from the materials of those masses which now are separated.
The pumice islands form the middle part of that chain, and are the farthest removed from that continent of which it is probable they once formed a part. They are connected with the promontory of Missene on the one hand, as being of the same or similar volcanic origin, and on the other with mount Circello, by a curious circumstance in the island Zanone, which, but a little more of the devouring operation of the sea, would have concealed from our observation.
The island of Ventotiene, which is the nearest of them to Ischia, would appear to be the ancient island of Pendataria, in which Julia was confined. The marks of degradation in this island, I would wish to give in the Chevalier’s own words, (p. 52.)
“Cette isle continue a etre devoree par la mer, elle l’attaque dans toutes les parties de son contour, ou elle trouve peu de resistance, et elle ne cesse de creuser, principalement, tous les escarpemens du nord. Il paroit, par les vestiges des antiquites qui sont sur la pointe dite di Nevola, que sous l’Empire de Cesar cette isle avoit encore une etendue plus considerable. Il s’y fait journellement des eboulemens; on peut prevoir qu’elle diminuera progressivement, qu’elle se divisera, et que dans les temps a venir elle sera reduite aux rochers de laves qui la supportent, et qui seuls peuvent resister, pendant une longue suite de siecles, a tous les efforts des flots; ce ne sera surement pas la seule terre que le temps et la mer auront devoree, et que les vicissitudes de la nature ont fait disparoitre avant que l’histoire en ait pu constater l’existence.”