SULPHUR [See also:

• SYMBOL (Gr. o-uµ(3oXov, a sign)

Sub-limed sulphur also results from the spontaneous combustion of See also:

• COAL

Sjogren to contain salts like those of sulphur-springs. An important See also:

• ZONE (Gr. 'WV77, a girdle, from 'wvvLvay to gird)

In the See also:

• BRITISH

The See also:

• SOLE (Solea)

The molten sulphur accumulates on the sole, whence it is from time to time run out into a square stone receptacle, from which it is ladled into See also:

• DAMP

Bollman in 1867 the ore may be extracted by See also:

• CARBON (symbol C, atomic weight 12)

The operation consists in forcing down the 3-in. pipe superheated steam at 330° F. to melt the sulphur. Compressed air is now driven down the I-in. pipe and bubbles into the melted sulphur and water; the specific gravity of which is greatly diminished, so that it rises to the See also:

• SURFACE

The addition of more acid would produce an additional See also:

• SUPPLY (through Fr. from Lat. supplere, to fill up)

2490) showed that the vapour density decreased with the temperature, and also depended on the pressure. G. Preuner and W. Schupp (Zeit. phys. Chem., 1909, 69, p. 157), in a study of the dissociation isotherms over 300°–85o°, detected molecules of S8, Ss and S2, whilst S, appears to exist below pressures of 30 mm. Boiling and freezing-point determinations of the molecular weight in solution indicate the formula S8. The density of solid sulphur is 2.062 to 2.070, and the specific heat 0.1712; it is a See also:

• BAD, BCD

1455), See also:

• HALF

2708). It is insoluble in water,' but readily soluble in carbon bisulphide, sulphur chloride and oil of See also:

• TURPENTINE (in M. Eng. turbentine, adapted through the O. Fr. turbentine or terebentine from Lat. terebinthina, sc. resina, resin of the terebinth, Gr. eepiOtvOos or eippavOos)

A triclinic form is claimed to be obtained by See also:

• FRIEDEL, CHARLES (1832-1899)

Soc., 1907, ii. 451). Molten Sulphur.—Several interesting phenomena are witnessed when sulphur is heated above its melting point. The solid melts to a pale yellow liquid which on continued heating gradually darkens and becomes more viscous, the maximum viscosity occurring at 180°, the product being dark red in colour. This See also:

• CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

Journ. Chem. Soc., 1907, ii. 20, 451, 757) regards molten sulphur as a mixture of two isomers SA and Ss in dynamic See also:

• EQUILIBRIUM (from the Lat. aequus, equal, and libra, a balance)

See also:

• SCHEELE, KARL WILHELM (1742-1786)

It is moderately soluble in water, the solution possessing a faintly acid reaction. This solution is not very See also:

• STABLE

Oxidizing agents rapidly attack sulphuretted hydrogen, the See also:

• PRIMARY

Sabatier by fractionating the crude product in vacuo obtained an oil which boiled between 60° and 85° C. and possessed the composition H4S5. Several halogen compounds of sulphur are known, the most stable of which is sulphur fluoride, SF6, which was first prepared by H. Moissan and See also:

• LEBEAU, JOSEPH (1794-1865)

It is gradually decomposed by water: 2S2C12 + 3H2O = 4HC1 -i- 2S + H2S2O3, the thiosulphuric acid produced in the primary reaction gradually decomposing into water, sulphur and sulphur dioxide. Sulphur chloride dissolves sulphur with great readiness and is consequently used largely for vulcanizing See also:

• RUBBER, INDIARUBBER

On cooling it solidifies to a crystalline mass which fuses at -8o° C. (Ruff, ibid.). Water decomposes it violently with formation of hydrochloric and sulphurous acids. Sulphur bromide, S2Br2, is a dark red liquid which boils with decomposition at about 200° C. The products obtained by the action of See also:

• IODINE (symbol I, atomic weight '26.92)

L. See also:

• LAVOISIER, ANTOINE LAURENT (1743-1794)

It is decomposed by the influence of strong light or when strongly heated. It combines directly with chlorine to form sulphuryl chloride and also with many metallic peroxides, converting them into sulphates. In the presence of water it frequently acts as a See also:

• BLEACHING

Since the free acid would be dibasic, two series of salts exist, namely, the neutral and acid salts. The neutral alkaline salts are soluble in water and show an alkaline reaction, the other neutral salts being either insoluble or difficultly soluble in water. The acid salts have a neutral or slightly acid reaction. The sulphites are prepared by the action of sulphur dioxide on the oxides, hydroxides or See also:

• CARBONATES

It is decomposed by water into hydrofluoric and sulphurous acids. Thionyl chloride, SOC12, may be obtained by the action of See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

Sulphur trioxide, SO3, mentioned by See also:

• BASIL (Russ. VASILY)

It finds considerable application in the colour industry. Sulphuryl fluoride, SO2F2, formed by the action of fluorine on sulphur dioxide (H. Moissan, Compt. rend. 132, p. 374), is an exceedingly stable colourless gas at ordinary temperatures, becoming solid at about — Ito° C. Sulphuryl chloride, SO2C12, first obtained in 1838 by See also:

• REGNAULT, HENRI (1843-1871)
• REGNAULT, HENRI VICTOR (1810-1878)
• REGNAULT, JEAN BAPTISTE (1754-1829)

See also:

• WILLIAMSON, ALEXANDER WILLIAM (1824–1904)
• WILLIAMSON, SIR JOSEPH (1633–1701)
• WILLIAMSON, WILLIAM CRAWFORD (18r6–1895)

An oxychloride of composition S2O3C14 has been described. Sulphur sesquioxide, S2O3, is formed by adding well-dried flowers of sulphur to melted sulphur, trioxide at about 12—15° C. The sulphur dissolves in the form of blue drops which sink in the liquid and finally solidify in blue-green crystalline crusts. It is unstable at ordinary temperatures and rapidly decomposes into its generators on warming. It is readily decomposed by water with formation of sulphurous, sulphuric and thiosulphuric acids, with simultaneous liberation of sulphur. Hyposulphurous acid, H2S204, was first really obtained by Berthollet in 1789 when he showed that iron left in contact with an aqueous solution of sulphur dioxide dissolved with-out any See also:

• EVOLUTION

This solution is yellow in colour, and is very unstable decomposing at ordinary temperature into sulphur and sulphur dioxide. A pure zinc salt has been prepared by Nabl (Monats., 1899, 20, p. 679) by acting with zinc on a solution of sulphur dioxide in See also:

• ABSOLUTE (Lat. absolvere, to loose, set free)

Soc.; also Bucherer and Schwalbe, Zeit. angew. Chem 1904, 17, p. 1447). Although this acid appears to be derived from an oxide S203, it is not certain that the known sesquioxide is its anhydride. Persulphuric anhydride, S2O7, is a thick viscous liquid obtained by the action of the silent See also:

• DISCHARGE (adapted from the O. Fr. discharge, modern decharge, from a med. Lat. discargare, to unload, dis- and earn care, to load, cf. " charge ")

771) by electrolysing solutions of the alkaline bisulphates. The potassium salt, after recrystallization from warm water, separates in large tabular crystals. Its aqueous solution gradually decomposes with evolution of oxygen, behaves as a strong oxidant, and liberates iodine from potassium iodide. Solutions of persulphates in the cold give no precipitate with barium chloride, but when warmed barium sulphate is precipitated with simultaneous liberation of chlorine : K2S2O3 + BaCl2 = BaSO4 + K2SO4 + C12. The conductivity measurements of G. Bredig point to the salt possessing the double formula. Thiosulphuric acid, formerly called hyposulphurous acid, H2S203, cannot be preserved in the free state, since it gradually decomposes with evolution of sulphur dioxide and liberation of sulphur: H2S203 = S+SO2+H20. The salts of the acid, however, are stable, the sodium salt in particular being largely used tor photographic purposes under the name of " hypo." This salt may be prepared by digesting flowers of sulphur with sodium sulphite solution or by boiling sulphur with milk of lime. In this latter reaction the deep yellow solution obtained is exposed to air when the calcium polysulphide formed is gradually converted into thiosulphate by oxidation, and the calcium salt thus formed is converted into the sodium salt by sodium carbonate or sulphate. The thiosulphates are readily decomposed by mineral acids with liberation of sulphur dioxide and precipitation of sulphur : Na2S2O3 + 2HCI = 2NaCl + S + SO2 ± H2O. They form many double salts and give a dark See also:

• VIOLET

This salt, on standing, decomposes into barium dithionate, BaS2O3, and diethyl disulphide, (C2H5)2S2, which points to the presence of the SH group in the See also:

• MOLECULE (from mod. Lat. molecula, the diminutive of moles, a mass)

The salts are unstable; and a solution of the free acid (obtained by the addition of hydrofluosilicic acid to the potassium salt) on concentration in vacuo decomposes rapidly: H2S3O6 = H2SO4 + S + SO2. Tetrathionic acid, H2S406, is obtained in the form of its barium salt by digesting barium thiosulphate with iodine: 2Ba2S2O3 + I2 = BaS4O6 + 2BaI, the barium iodide formed being removed by alcohol; or in the form of sodium salt by the action of iodine on sodium thiosulphate. The free acid is obtained (in dilute aqueous solution) by the addition of dilute sulphuric acid to an aqueous solution of the barium salt. It is only stable in dilute aqueous solution, for on concentration the acid decomposes with formation of sulphuric acid, sulphur dioxide and sulphur. \Vackenroder's solution (Debus, Journ. Chem. Soc., 1888, 53, P. 278) is prepared by passing sulphuretted hydrogen gas into a nearly saturated aqueous solution of sulphur dioxide at about o° C. The solution is then allowed to stand for 48 See also:

• HOURS, CANONICAL

The formation of the pentathionic acid may be represented most simply as follows: 5SO2 + 5H2S = H2S506 + 5S + 4 H2O. The aqueous solution of the acid is fairly stable at ordinary temperatures. The pentathionates give a brown colour on the addition of ammoniacal solutions of silver nitrate and ultimately a See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

E. See also:

• ARMSTRONG, ARCHIBALD (d. 1672)
• ARMSTRONG, JOHN (1709-1779)
• ARMSTRONG, JOHN (1758—1843)
• ARMSTRONG, SAMUEL CHAPMAN (1839—1893)
• ARMSTRONG, WILLIAM GEORGE ARMSTRONG, BARON (1810—1900)

105; T. S. Price, Ber., 1902, 35, p. 291; Journ. Chem. Soc. (1906), p. 53; A. v. See also:

• BAEYER, JOHANN FRIEDRICH WILHELM ADOLF VON (1835– )

From it are made (a) confectio sulphuris ; (b) unguentum sulphuris; (c) sulphur praecipitatum, milk of sulphur (U.S.P.) which has a sub-preparation trochiscus sulphuris each See also:

• LOZENGE (from the Fr. losenge, or losange; the word also appears in Span. losanje, and Ital. losanga; perhaps derived from a word meaning a stone slab laid on a grave, which appears in forms such as Provencal lousa, Span. losa, the ultimate origin of whic