Pliny's Letters, vol. i. book vi. p. 325, Melmotli's translation. ' A piece of glass fastened on the top of a pole, and thrust into this matter, was in four minutes reduced to a paste.Under the mass of the torrent were heard frequent reports, which made the church shake as if by an earthquake. Along the whole surface of the torrent there appeared small fissures, out of which issued smoke that stunk of brimstone mixed with sea-water ; yet these exhalations are not poisonous, but rather a remedy for some diseases. The stones round about these fissures were observed to be covered with sublimed salts, the nature of which I shall explain hereafter. Iron thrust into these fissures, was taken out moist ; but upon thrusting in paper, it was not moistened but rather somewhat hardened.' At the same time when the new mouth opened, that on the summit of the mountain vomited a vast quantity of burning matter, which, dividing into torrents and small streams, ran partly towards the Salvadore, and partly towards Ottajano ; and at the same time that this matter issued out, red-hot stones were seen to be cast out of the mouth, in the midst of black smoke, frequent flashes of lightning, and thunder, all produced by the same matter. These * Philosophical Transactions.f Aspects of Nature. \ Fragments of incandescent pumice-stones. * Poulett Scrope. c 3 * We owe these details to an interesting letter addressed by a geologist, M. Fonque, a witness of the eruption, to M. Ch. Sainte-Claire Deville.* The sedimentary earths have been deposited by the waters in horizontal beds, afterwards inclined, upheaved by rocks of eruption and earthquakes.