noun
Historical or fantasy term for the medieval proto-science of transmuting base metals into gold and seeking the philosopher's stone. Not used for modern chemistry.
中世ヨーロッパでは黄金術が盛んに研究された。
In medieval Europe, alchemy was actively studied.
彼は黄金術に没頭し、賢者の石を探し求めた。
He devoted himself to alchemy and sought the philosopher's stone.
化学 means 'chemistry' as a modern science, distinct from the historical/mystical practice of alchemy.
Compound of 黄金 (おうごん, 'gold') and 術 (じゅつ, 'art, technique'). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning 'alchemy'.