Sulfur is a non metallic chemical element. It is found in nature both in its pure state, when it is a yellow crystalline solid and combined with other elements in compounds such as sulfides (metal pyrites) and sulfured. Sulfur burns readily and the old English name for it is brimstone from “burning stone”.
Nine-tenth of the world sulfur is obtained from huge dome-shaped formations underground in Louisiana and Texas in the United State. These deposits were discovered in 1865 but for a long time there was no way of getting the sulfur from them. Then Herman Frasch invented the process that is named after him and that has been used since 1903. Three pipes fitting one inside the other are sunk into the dome. Very hot water is forced down between the outer pipes, thus melting the sulfur. Compressed air led through the innermost pipe forces the molten sulfur to the surface through the middle pipe. Boiling Dome in Texas has been a major source of sulfur since 1929.
Sulfur is also found in a fairly pure state in countries where there are volcanoes, especially in Sicily and Japan. Sulfur is contained in some commonly occurring rocks, notably gypsum and anhydrite which are different forms of the compound calcium sulfate. Sulfur can exist in several different physical forms or allotrope. The chief use of sulfur is in making sulfuric acid. It is also used to vulcanize or toughen rubber. The chemical used for spraying trees to destroy insects and fungus growth often contain sulfur and in some countries vines are dusted with sulfur powder. Sulfur is used in the manufacture of gunpowder and some kind of poison gas and also in drugs, ointments and medicines. Sulfur amides are an important class of anti bacterial drugs and are used to treat various diseases including pneumonia and meningitis.
There are small amounts of sulfur in hair, wool and eggs and also in plants such as garlic, mustard, horseradish and cabbage. The rather unpleasant smell given off by cabbage when it is cooking is caused by the gas hydrogen sulfide. It is sulfur in egg and mustard that tarnishes (discolors) silver spoons. Sulfur is harmful in steel and has to be removed from crude oil when it is refined.
Sulfur dioxide is a heavy, colorless, poisonous gas with a pungent smell. It is obtained by roasting copper pyrites and iron pyrites in air. Large amounts are produced when sulfur containing fuels such as coal oil are burned and sulfur dioxide is a major cause of air pollution in industrial areas and is largely responsible for acid rain. The major use of sulfur dioxide is in the manufacture of sulfuric acid. It is also a bleaching agent and substances which give off this gas such as calcium and sodium bisulphate are used for bleaching wood pulp for paper, wool, silk, and straw.
