Sulphocyanic Acid

Collier's New Encyclopedia (1921)

HCNS; hydrogen sulphocyanate; a monobasic acid obtained by decomposing lead sulphocyanate suspended in water, with sulphuretted hydrogen. It is a colorless, very acid liquid, with a pungent acetous odor, and solidifies at- 12.5° to hexagonal plates. Heated to 100° it boils, but the greater part suffers decomposition. It colors ferric salts an intense bloodred, and on this account is used, in the form of any of its soluble salts, to detect traces of iron. SULPHUR. Sulphur, or brimstone, has been known and used from the earliest times. It is found native in mechanical combination with various earthy impurities in most volcanic districts, more particularly in Sicily and the countries bordering on the Mediterranean in and Texas. The native sulphur Louisiana commerce was formerly derived chiefly from Sicily, where it occurs in found native in two forms-in transparent amber crystals, as virgin sulphur; or in opaque, lemon-yellow crystalline masses, as volcanic sulphur. It is found in combination with the different metals, forming metallic sulphides, in nearly cly every portion of the earth. Zinc blende, iron, and copper pyrites, galena, cinnabar, gray antimony, and realgar, are a few instances of the valuable ores containing sulphur. In its oxidized condition, as sulphuric acid, it is also very largely distributed over the mineral kingdom. Sulphur exists in many organic bodies; for example, it is always contained in albumen and the various protein compounds. Native sulphur is purified from the foreign substances mixed with it by distillation in, first, long brick furnaces containing earthen retorts communicating with chambers of the same material; and afterward in iron retorts communicating with chambers of brickwork, in which the sulphur to the chlorides. The iodide is a cryscondenses in light flocks, known as flowers of sulphur. When melted and cast, these form the roll brimstone of commerce. Sulphur can also be easily extracted from iron and copper pyrites. At ordinary temperatures, sulphur is a brittle, insoluble, inodorous solid, of a lemonyellow color, a bad conductor of heat , and a non-conductor of electricity. By friction with silk or wool, it becomes negatively electrified. It is a highly inflammable substance, burning readily in the air at about 450° or 500° F., and giving off suffocating fumes of sulphurous acid gas. At 239° F. it melts, forming a yellow liquid, and slightly increasing in bulk. Provided the above temperature is not exceeded, it remains nearly transparent on on cooling, c but becomes gradually opaque from interior molecular changes. In close vessels, it may be distilled by raising the heat to about 834° F. Sulphur is very remarkable as affording a striking instance of the occurrence of the allotropic condition of matter. Hydrogen and sulphur vapor, when burnt, form sulphuretted hydrogen. Burnt in oxygen, heated with chlorine , bromine, and iodine, it unites with them, forming well-known compounds . The vapor of sulphur passed over red-hot charcoal forms bisulphide of carbon . Nearly all the metals combine with it at ordinary or increased temperatures . Sulphur combines to form the following acids: Sulphurous acid. Sulphuric acid. Dithionous acid. Dithionic acid. Trithionic acid. Tetrathionic acid. Pentathionic acid. talline brittle gray solid. With nitrogen, sulphur forms a bisulphide which crysin beautiful golden-yellow tallizes rhombic crystals. It detonates powerfully by percussion, or when heated to 314° F. Bisulphide of carbon dissolves it readily, alcohol, ether, and oil of turpentine sparingly, and water not at all. Symbol S; at. wt. 32. Prior to 1902 the chief source of sulphur was Sicily . In that year, however, by a remarkable series of inventions, following years of research, Herman Frasch, a chemist, succeeded in extracting sulphur from vast deposits in Louisiana and Texas. The process, in brief, consists in melting the sulphur, which lies underground , by superheated water. It is then driven to the surface by compressed air. The production in the_United States, almost entirely from Louisiana, was in 1919 , 1,210,000 long tons, valued at $16,750,- 000. There were exported 224,712 long tons, valued at $6,325,552.