of a new crater, with constant ascension of dense white steam, impregnated with the carburetted hydrogen gas, which blackened the silver and watches in the pockets of the observers. That this vapour was not impregnated with sulplur, I infer, first, from the absence of that peculiar fetor, and its not atFecting the lungs; secondly, from the colour of the water in the crater, which, by coming in contact with sulphuretted hydrogen gas, would have been changed to a protoxide, and been black in place of red. This last chemical test I consider conclusive on this point; but it has been the custom to speak of sulphureous smoke, which, by-the-bye, may have been ejected in actual combustion, during the violence of previous eruptions, but certainly not now, in form of gas.
“On our descent, passing the margin of the crater, where it was not more than twenty feet to the boiling surface, I threw off my jacket, and jumped down, to the astonishment of all present, anxious alike to procure something from the cauldron, and try the temperature of the water.
I plunged my hand into the margin, but quickly withdrew it, finding it about 190° of Fahrenheit; the reduction of twenty-two degrees being easily explained, on reflecting on the extended surface becoming exposed to the atmosphere in a basin, as before mentioned, of two hundred and seventy feet in circumference. The water was excessively salt, owing to the continued evaporation, since the direct communication with the sea has been closed (probably with the last eruption), and appears something lower than the sea, leaving evident marks of decrease on the coloured masses of scoria round the margin.
“The island is about a mile in circumference, nearly round, or perhaps an imperfect spheroid, indented at the ends, where the great crater was at different periods connected with the sea. It is about one hundred and fifty or sixty feet high. The substance of which the island is composed is chiefly ashes, the pulverised remains of coal deprived of its bitumen, iron scoria, and a kind of ferruginous clay or oxided earth. Thee scoria occurs in irregular masses: some compact, dense, ami sonorous; others light, friable, and amorphous with metallic lustre, slightly magnetic, barely moving the load-stone. I only procured one native stone, a piece of limestone about two pounds weight, thrown up with the incumbent earth, having no marks of combustion. There was no trace whatever of lava, no terra puzzolana, no pumice stone, no shells or other marine remains, usually found at AEtna and Vesuvius. Around the island, where Neptune makes his advances, the sides fall down in abrupt precipices; and we could discern every strata ejected by each separate eruption; the water evaporating, left an incrustation of salt, which now appears a white, firm layer, plainly marking the regular progress and formation of the island. The surface of the island is likewise covered with a similar incrustation, in some places so thick as to be visibly white at some distance at sea.
