Sulfur vulcanization a reaction with low levels of unsaturated organic linkers (e.g. 1,3‐diisopropenylbenzene). This process is called inverse vulcanisation and produces polymers where sulfur is the main component. It is not currently of commercial importance but had been investigated as a means of producing polymers for lithium–sulfur batterys and for creating water filters with a high affinity for mercury. The curing of rubber has been carried out since prehistoric times. The name of the first major civilization in Guatemala and Mexico, the Olmec, means 'rubber people' in the Aztec language. Ancient Mesoamericans, spanning from ancient Olmecs to Aztecs, extracted latex from "Castilla
Sulfur 14th century the Latin ' was restored, for '; and by the 15th century the full Latin spelling was restored, for "sulfur, sulphur". The parallel "f~ph" spellings continued in Britain until the 19th century, when the word was standardized as "sulphur". "Sulfur" was the form chosen in the United States, whereas Canada uses both. The IUPAC adopted the spelling "sulfur" in 1990, as did the Nomenclature Committee of the Royal Society of Chemistry in 1992, restoring the spelling "sulfur" to Britain. Oxford Dictionaries note that "in chemistry and other technical uses ... the "-f-" spelling is now the standard form