The experiments of M. Vauquelin, (_Annales de Chimie_, 1811) to determine the quantity of sulphur contained in some metallic sulphurets, show, at once, the proportion which may be obtained from those combinations. Thus he found, that sulphuret of copper contains 21.31 per cent of sulphur; sulphuret of tin, 14.1; sulphuret of lead, 13.77; sulphuret of silver, 12.73; sulphuret of iron, 22; sulphuret of antimony, 25; sulphuret of bismuth, 31.75; sulphuret of manganese, 74.5; and sulphuret of arsenic, 43. Of native or prismatic sulphur, there are two species, the common and volcanic. The former is of two kinds, the compact and earthy. Sulphur, says Hanway, (_Travels, &c._) is dug at Baku on the western side of the Caspian sea. It is found in the neighbourhood of the celebrated naphtha springs, some of which form a mouth of 8 or 10 feet diameter. Von Humboldt (_Annales de Museum National_) communicated to the French national institute, that he discovered, in the province of Quito, a bed composed of sulphur and quartz, in a mountain of mica slate, and also sulphur in primitive porphyry. Kirwan (_Geological Essays_, p. 143) observes, that sulphur promotes decomposition, by absorbing oxygen, while it is thus converted into vitriolic acid; but moisture is also requisite. He attributes, in the same manner, the decomposition of stones that contain pyrites. As the sulphur, which occurs in commerce, is chiefly obtained from its native combinations, it may be proper to make some brief remarks on this head. Sulphur in the state of combination is abundantly met with, and in all countries. It is found in the state of sulphuric acid, in various salts, as gypsum, epsom salt, native alum, &c.; and united with metals, forming natural sulphurets, as in sulphuret of iron, or iron pyrites, sulphuret of copper, or copper pyrites, sulphuret of lead, or potter's lead ore, called also galena, sulphuret of antimony, or crude antimony, sulphuret of zinc, or blende, sulphuret of mercury, or cinnabar, sulphuret of arsenic, or orpiment, &c. In fact, it appears to be a general mineralizer. It is found also in some plants, and in animal substances.