Sulphur, or Brimstone, a hard inflammable mineral, of a yellow colour: it is insoluble in water; destitute of smell, except by friction, or when heated ; and possesses a peculiar, faint taste. - This simple substance is found, in a native state, in various parts of the world, particularly in the vicinity of volcanoes, being often combined with other minerals : it is generally cast into rolls, for sale, being known under the name of roll-brimstone.

Sulphur, when gently heated. rises in vapours, which are easily kindled ; and, if it be suffered to cool gradually, it shoots into crystals resembling thin needles, termed flowers of sulphur : when combined with any alkaline salt, such as pot-ash, and melted in a moderate beat, and in a close vessel, a compound is produced, which is named liver of sulphur. This preparation is of a liver-brown hue; and, while dry, emits no peculiar odour; but, in a moist state, it evolves a very offensive smell, resembling that of put : it deli-quatcs in the air, and is completely dissolved in water; the solution acquiring a yellow, golden shade. On melting it in a continued heat, till it grows tough, and assumes a red-brown colour, then pouring the liquid mass into water, it will remain as soft as wax, and yield to any impression from engraven stones, metals, or coins. After becoming cold, however, it recovers its former hardness and colour.

This mineral is usually imported in large irregular masses, which are melted into rolls, with the addition of coarse resin, flour, etc.; whence it assumes a pale yellow tint. It pays, on importation, the sum of 7s. 4d. per cwt.

Sulphur is of great utility in the arts: when converted into an acid by combustion in the open air, it affords that extensively useful liquid, vulgarly termed oil of Vitriol ; considerable quantities of which are consumed in the various processes of bleaching, dissolving metals, especially iron, and in other useful arts : it is also of great service in cementing iron railing to stones, by simply melting, and pouring it into the interstices. See also GuN-PowDER. - Brimstone is farther advantageously employed for whitening silk, wool, or other articles, by exposing them to its fumes, during combustion.

In medicine, sulphur is almost a specific in cutaneous diseases, whether administered internally with honey or molasses, or applied externally in the form of ointment. In the piles, it is of evident benefit, when taken in small doses; nay, it is occasionally prescribed in chronic catarrhs and coughs ; as it operates gently, by promoting insensible perspiration through every pore of the skin. - See likewise Antidotes.