sulphur (symbol S) Nonmetallic element in group VI of the periodic table, known since pre-history (the biblical brimstone). Essential to animal and plant life, it may occur naturally as a free element or in sulphide minerals such as galena and iron pyrites, or in sulphate minerals such as gypsum. The main commercial source is native (free) sulphur, extracted by the Frasch process. It is used in the vulcanization of rubber and in the manufacture of drugs, matches, dyes, fungicides, insecticides, and fertilizers. Properties: at.no. 16; r.a.m. 32.064; r.d. 2.07; m.p. 112.8°C (235°F); b.p. 444.7°C (832.5°F). Most common isotope S³² (95.1%).

sulphur, U.S. sulfur greenish-yellow nonmetallic element; brimstone. XIV. ME. soufre, solfre, sulph(e)re — AN. sulf(e)re, (O)F. soufre :- L. sulfur, -phur. Comb. form sulpho-, before a vowel sulph-.
So sulphate/sulphite salt of sulphuric/sulphurous acid. XVIII. — F. sulphat/sulphite. sulphureous pert. to sulphur XVI; †hellish, satanic XVII. f. L. sulphureus. sulphuretted combined chemically with sulphur. XIX. f. sulphuret- modL. sulphuretum; see -URET. sulphuric s. acid XVIII. — F. sulfurique. Hence sulphide compound of sulphur with another element. XIX. sulphurous, sulphury (-Y1) XVI. See -Y1.

sulphur (sulfur) An element that is part of the amino acids cystine and methionine and is therefore present in all proteins. It is also part of the molecules of vitamin B₁ and biotin and occurs in foods and in the body as sulphates. Apart from these amino acids and vitamins, there appears to be no requirement for sulphur in any other form and no deficiency has ever been observed, although it is essential for plants.

Not only was the old‐fashioned remedy of sulphur and molasses (brimstone and treacle) quite unnecessary, but elemental sulphur is not used by the body.

sulphur (S) An element that is needed for plant life. It is found covalently bound, especially in proteins, where it stabilizes their structures. It is also involved in oxidation and reduction reactions. Sulphur-deficient plants become chlorotic (see CHLOROSIS) and etiolated (see ETIOLATION).

sulphur(S) An element that is needed for plant life. It is found covalently bound, especially in proteins, where it stabilizes their structures. It is also involved in oxidation and reduction reactions. Sulphur-deficient plants become chlorotic (see chlorosis) and etiolated (see etiolation).