it is moulded into blocks of about four arrobas.  Half the oil employed is recovered by throwing the clay which has been saturated with it into a frame formed by two narrow bamboo hurdles, placed at a sharp angle.  The oil drops into a sloping gutter of bamboo which is placed underneath, and from that flows into a pot.  The price of the sulphur at Manila varies between [Prices.] $1.25 and $4.50 per picul.  I saw the frames, full of clay, from which the oil exuded; but the operation itself I did not, unfortunately, then witness, and I cannot explain in what manner the oil is added.  From some experiments made on a small scale, therefore under essentially different conditions, and never with the same material, it appeared that the oil accelerates the separation of the sulphur, and retards the access of the air to the sulphur.  In these experiments, the sulphur contained in the bottom of the crucible was always colored black by the separation of charcoal from the oil, and it was necessary to purify it by distillation beforehand.  Of this, however, the smelters at Leyte made no mention, and they even had no apparatus for the purpose, while their sulphur was of a pure yellow color.

[Hot spring.] Some hundreds of paces further south, a hot spring (50 deg.  R.), [192] twelve feet broad, flows from the east, depositing silicious sinter at its edges.

[A solfatara.] As we followed a ravine stretching from north to south, with sides one hundred to two hundred feet in height, the vegetation gradually ceased, the rock being of a dazzling white, or colored by sublimated sulphur.  In numerous places thick clouds of vapor burst from the ground, with a strong smell of sulphurated water.  At some thousand paces further, the ravine bends round to the left (east), and expands itself to the bay; and here numerous silicious springs break through the loose clay-earth, which is permeated with sulphur.  This solfatara must formerly have been much more active than it is now.  The ravine, which has been formed by its destruction of the rock, and is full of lofty heaps of debris, may be one thousand feet in breadth, and quite five times as long.  At the east end there are a number of small, boiling quagmires, which, on forcing a stick into the matted ground, send forth water and steam.  In some deep spots further west, grey, white, red, and yellow clays have been deposited in small beds over each other, giving them the appearance of variegated marls.

[Petrifying water] To the south, right opposite to the ridge which leads to Burauen, may be seen a basin twenty-five feet broad, in a cavern in the white decomposed rock, from which a petrifying water containing silicious acid flows abundantly.  The roof of the cavern is hung with stalactites, which either are covered with solid sulphur, or consist entirely of that substance.