SULPHUR (Lat. sulphur, sulfur, sulphur; possibly connected with Goth. szeibls, 011G. swchal, Ger. Sehirefcl, AS. swell, sulphur). A non-metallic element that has been known since ancient times. Owing to the fact that it burns readily, it was called hi-cam-stone o• brimstone, and was regarded by the alchemists as the prin ciple of combustibility, representing the altera bility of metals by firc. It occurs in the uncom bined state, though usually contaminated with clay, bitumen, and other impurities, and some times with traces of arsenic, selenium, tellurium, etc.. usually in the vicinity of volcanoes and hot springs. Its compounds, especially those with metals (sulphides), are of common occurrence, and include chalcopyrite or copper-iron sulphide, cinnabar or mercury sulphide, galena or lead sulphide, pyrite or iron sulphide, the arsenic sulphides or realgar and orpiment, sphaleritc or zinc sulphide, stibnite or antimony sulphide. In combination with metals and oxygen (sulphates), sulphur occurs in such minerals as unglesite or lead sulphate, barite or barium sulphate, celes tite or strontium sulphate, chalcanthite or cop per sulphate, gypsum or ealcimn sulphate, and kieserite or magnesium sulphate. Volcanic gases generally contain sulphur in the forms of sulphur dioxide and solphri•eted hydrogen, and com pounds containing sulphur are found in certain organic materials, such as the volatile oils of mustard and garlic, hair, wool, bile, and albuminous substances. It is generally be lieved that native sulphur has been formed by the action of sulphur dioxide on hydro gen disulphide. Sulphur may also be ob tained by decomposing certain mineral sul phides, such as pyrite. The commercial ar ticle is usually obtained by purifying native sulphur by fusion, or by distillation, and is produced largely in Sicily, where it occurs mixed with celestite, gypsum, limestone, and marl. The ore, after being carefully hand-picked. was for merly heated in heaps from which the liquid sul phur collected in a trough at the bottom, whence it was ladled out; but as this process was very wasteful, kilns came into use, in which the sul phur ore was piled and ignited at the bottom; the heat penetrated slowly into the mass, and as the sulphur- gradually melted it ran to the bot tom of the kiln, where it was collected and then cast into molds. Sulphur may also be extracted
from ores by using a solvent such as carbon di sulphide, from which it is then separated by dis tillation. Crude commercial sulphur usually contains about 3 per cent, of earthy impurities, which may be removed by distillation, in which case the sulphur is first melted and then heated to the boiling-point, the vapor of sulphur then passing into a large chamber, where it condenses and falls to the floor in the form of a light yel low crystalline powder commonly known as /lowers of sulphur. This is cast into slightly conical wooden molds, when it is known as roll sulphur or brimstone, and sometimes it is al lowed to cool in the chamber, when it is obtained in large crystalline masses called block sulphur.
Sulphur (symbol, S; atomic weight. 32.07) occurs in several allotropic modifications. One of these is a brittle solid that crystallizes in the rhombic system, but that on heating passes into transparent yellowish-brown needles of the mono clinic system. Both of these forms are soluble in carbon disulphide. The modifications of sul phur that are insoluble in carbon disulphide in clude plastic, amorphous, yellow, and black sul phur. There is a variety of sulphur that is soluble in water. This is known as colloidal sul phur and is obtained by passing hydrogen disul phide into an aqueous solution of sulphur di oxide. Sulphur has a specific gravity of about 2.03, and melts variously from 111° to 115° C. It is a poor conductor of heat and electricity. The element itself is extensively used in the arts and manufactures, as in making gunpowder and matches, and in medicine.