Flowering of alchemy in the Islamic world Later Islamic alchemists pushed alchemy further down the road to being a real science. Iranian alchemist and physician ar-Razi (c. 865–c. 923/932) concerned himself more with practical chemical knowledge based on experiment rather than the natural philosophy of changes in matter, and greatly contributed to the hard knowledge base of alchemy. He accepted atomism, however. Abu Ali ibn Sina (980–1037), known as Avicenna and also of Iran, vehemently rejected the idea of transmutation (the conversion of "base" metals, such as tin or lead, into precious "noble" metals, such as silver or gold). Avicenna would greatly influence Western alchemists.