SULPHONIC ACIDS

are acids having RUSSELL an organic group combined with th playwright; group SO:0H; most of these acids ar in crystalline solids, and some of then relinoccur as important steps in the prepara Boston. tion of synthetic compounds, period plays and a element; also known as Lmstone Mr. thought by alchemists to be the principl of combustibility; occurs uncombinec in volcanic districts, and combined witl de oxygen or hydrogen in volcanic gases statesman; also as sulphides—(e.g.) iron pyrite 1575; FeS:2, copper pyrites CuFeSs, galen: Henry | P bS, cinnabar HgS; and sulphates— (e.g.)_ gypsum CaSO.-+2H:0, Epsom salts MgSO.+7H:0. The two competing sources of supply are Sicily and U.S. In Sicily it is obtained from the stony material with which it is mixed by heating in a furnace. Some of it burns, but most of it melts and Tuns away. It is purified by distillation. Condensation of vapor below 110° ©. yields flowers of sulphur (sulphur snow); above this temp. liquid sulphur, which is cast in moulds. In Texas and Louisiana the sulphur is melted and forced to ascend to the surface by means of superheated steam and compre ed air led down boreholes into the sulphur rock. Also obtained from coal, as a by-product in manufacture of coal gas, and recovered from the calcium sulphide which forms alkali-makers’ waste. Properties: sulphur shows allotropy. gr. 2°05-2°07, form at atmospheric temp. from state of vapor, fusion, or solution in carbon disulphide. Monoclinic prisms, from fusion at 96° C. or above. Prismatic crystals, kept at atmospheric temp., break down internally to the more stable octahedral form. Amorphous sulphur is precipitated from polysulphide solution by acid.. Plastic sulphur, amorphous but unstable, is formed by dropping molten sulphur near its b.p. into cold water. Sulphur melts to a yellow, mobile liquid, which at 160° C. grows darker, thicker, and very viscous; above 260° C. it becomes more mobile, and boils at 444°5° C., forming an orange vapor which contains Ssmolecules and simpler forms. Sulphur purns in air with a blue flame, forming sulphur dioxide gas.