Как правильно, sulphur или sulfur? Или оба варианта допустимы? В сети попадаются оба, в книгах преимущественно sulfur.
Цитата: OEDsulphur (n.) see sulfur. The form preferred in Britain; however, the spelling's suggestion of a Greek origin is misleading.
sulfur (n.) also sulphur, c. 1300, from Anglo-French sulfere, Old French soufre "sulfur, fire and brimstone, hellfire" (13c.), later also sulphur, from Late Latin sulfur, from Latin sulphur, probably from a root meaning "to burn." Ousted native brimstone and cognate Old English swefl, German schwefel, Swedish swafel, Dutch zwavel. The spelling with -ph- is standard in Britain, but its suggestion of a Greek origin is misleading.
Ага, это ещё и зависит от страны...