ISCHIA IN “ENCYCLOPÆDIA METROPOLITANA” (1800)
English · Published
ISCHIA, an Island in the Bay of Naples, about foar miles from Terra di Lavora, has an extent of about eighteen square miles. The Ancients (Strabo, i.54) believede that it was at one time united to the Continent, from which it was separated by volcanic convulsious. This opinion, howewer, appears to have been derived rather from conjecture than tradition. Modern speculators are more disposed to believe that the Island was raised from the sea by subterranean fires. The mountain, called by the Ancinets Epopeus, and at present Monte di S.Nicola, is considered by them as the original volcano, while subsequent lateral eruptions have produced the other mountains which form the Island (Galanti, Descr Geogr. Et Pol. Delle Sicilie, 1793 iv.171.)
The ancient names of this Island have given rise to much leanerd disputation. Pliny (lib. Iii. c.6) wrotes as follows: Aenaria a statione navium Aenae, Homero Inarime dicta, Grecis Pithecusa, non a simiarum multitudine, ut aliqui existimavere, sed a figlinis doliorum. These explanations are all rejected by Bochart (chanann, c.33) as absurd. It is evident, indeed, that Homer never designed the Isle of Ischia by his expression ἐιν Ἀρίμοις, although Virgil (Aen. in. v.716) appears to have adopted that opinion. Neither will the costruction of the Latin language allow us to believe that Aenaria is derived from Aeneas. Those who suppose the Island to be called Aenaria, quasi Ahenaria from its mines of copper, assume a fact which is dissporved by the mineralogical constitution of the soil (Hofmanni Lex, ad v.) Nor is the conjecture of Salmasius (Exercti p.97) who maintains against the authority of Pliny, that Pithecusa means the Island of Monkeys, a whit more fortunate, for he read Enaria; the Island being so called, as he supposes, from the monkeys, qui enares sunt. The writers of antiquity, as well as their modern commentators, generally err in their etymological conjectures, from forgetting that the roots of the Greek and Latin languages are to be sought not in those languages themselvesw, but in others of more ancient date.
Ischia, like the other Islands of this coast, is evidently of volcanic origin. The lavas are in great variety, and of all colours, from white to red and from red to black. They abound in feldspath, according to Dolomieu and have in general porphyry for their base. The feldspath crystals are more or less visible in the lavas, in proportion to their size and number. Some of them are opaque and others semi-trasparent, but they have alla remained unaltered by the fire which has reduced their base into a state of fusion.
The lavas of Ischia differ from those of Vesuvius is not containing any granite, and very little schorl. Pumice is found there of different degrees of density, but always with the lengthened fibres, which are observable in lavas having feldspath as their base. The hornstone lavas, on the other hand, always present a covering of black scoria. The volcanoes of Ischia, which have very frequently broken forth, and have opened a great number of craters round Mount Epopeo, or S.Nicola, in the centre of the Island, have produced both kind of lava.
In Ischia there are great number of fumarolli, or apertures emitting sulphureous-acid vapours, either dry or aqueous. These have the property of decomposing the lavas, giving them a whitish colur, and reducing them to an argillaceous consistence. There are, however, some volcanic products on the Monte Epopeo of a pure white colur, which have never been exposed to the action of these vapours; mica and crustals of feldspath are found in these melted masses