Chou i ts’an t’ung ch’i

The Chou i ts'an t'ung ch'i is the oldest known Chinese alchemical treatise. It is primarily an apocryphal interpretation of the I Ching, connecting alchemy to the mystical mathematics of its 64 hexagrams. Chinese alchemy, which may have originated before metallurgy, was closely linked to medicine and the pursuit of physical immortality.12

This practice became associated with Taoism, a religion founded by Lao-tzu. While early Chinese alchemy focused on external methods (waidan), later developments, particularly during the Song dynasty, emphasized internal alchemy (neidan). This shift involved using alchemical language to describe physiological processes within the body, rather than seeking to create tangible elixirs. Despite its eventual fading, Chinese alchemy's focus on immortality and medicinal elixirs distinguished it from Western alchemy's evolving objectives.23