Editing Jabir ibn Hayyan (section)

=== Elements and natures ===
According to [[Aristotelian physics]], each [[Classical element|element]] is composed of two qualities: [[fire (classical element)|fire]] is hot and dry, [[earth (classical element)|earth]] is cold and dry, [[water (classical element)|water]] is cold and moist, and [[air (classical element)|air]] is hot and moist. In the Jabirian corpus, these qualities came to be called "natures" (Arabic: ''ṭabāʾiʿ''), and elements are said to be composed of these 'natures', plus an underlying "substance" (''jawhar''). In metals two of these 'natures' were interior and two were exterior. For example, lead was predominantly cold and dry and gold was predominantly hot and moist. Thus, Jabir theorized, by rearranging the natures of one metal, a different metal would result. Like [[Zosimos of Panopolis|Zosimos]], Jabir believed this would require a catalyst, an ''al-iksir'', the elusive elixir that would make this transformation possible&nbsp;– which in European alchemy became known as the [[philosopher's stone]].<ref>{{harvnb|Nomanul Haq|1994}}.</ref>