Sulphur is found native in volcanic districts, and occurs in combination with metals as sulphites in various ores, especially in iron and copper pyrites.

Sulphur Sublimatum, B.P. and U.S.P. Sublimed Sulphur, Flowers of Sulphur.

Characters. - A fine, slightly gritty, citron-yellow or greenish-yellow powder, without taste or smell unless heated. It may sometimes have a slight characteristic odour, a faintly acid taste and an acid reaction from slight oxidation occurring with the formation of small quantities of sulphurous acid.

Solubility. - It is insoluble in water or alcohol, slightly soluble in oils and fats, and completely soluble in carbon disulphide.

Reaction. - When ignited it burns with a blue flame, forming sulphurous acid gas, and leaving no residue, or only a trace.

Preparation. - By sublimation from crude or rough sulphur. Native sulphur is usually mixed with earthy impurities. When heated the sulphur volatilises. If the vapour is condensed in a large room it falls in a fine powder. If condensed in water it forms masses, which, when melted and run into moulds form roll sulphur, but this is not officinal. Ores containing sulphur are decomposed by heat, and part of the sulphur they contain sublimes, and may be condensed in the same way as native sulphur.

Impurities. - Ores are apt to contain arsenic, and when this is the case sulphide of arsenic, being volatile, sublimes along with the sulphur and renders it impure. During sublimation the sulphur may undergo oxidation, and thus sulphurous or sulphuric acid may be present in it as impurities. Tests. - Vide Sulphur Lotum.

Officinal Preparations

U.S.P

Sulphur Lotum.

,, Praecicipitatum.

Emplastrum Ammoniaci cum Hydrargryro.

,, Hydrargyri.

Pulvis Glycyrrhizae Compositus (1 in 12) 30 to 60 gr. Unguentum Sulphuris.

Used in preparing : Anthnonium Sulphuratum. Potassa Sulphurata. Sulphuris Iodidum. Sulphur Praecipitatum.

Unguentum Sulphuris.