Background of Wei Boyang
Wei Boyang, a famous alchemist of the Eastern Han dynasty (AD 25-220), was also known by his literary name Yunyazi. A native of Shangyu, Guiji, he was born in a distinguished family. It had been a family of gentry officials for generations, and only Boyang loved Dao by nature and was reluctant to secure an official position. He lived leisurely, nourishing his inborn nature, and was unknown by people of his time.
Practicing Dao and seeking immortality by taking elixirs
Wei Boyang practiced perfection in secret and nurtured his aspiration to attain to nothingness. He had wide and rich knowledge of literature and a good command of Apocryphal Books of Divination ( 緯侯 Weihou ). Wei remained unruffled, preserved simplicity, followed nothing but Dao, and regarded ranks and titles as worthless. Having received the Great Dao of the Golden Elixir from Yin Changsheng, he went into the mountains to make Divine Elixirs with his three disciples, and succeeded. Knowing some of the disciples were not guarding Dao sincerely, he tested them by feeding a white dog with elixirs, which was killed temporarily, and then taking elixirs himself. He also died momentarily. Only one disciple, named Yu, said, "My master is not an ordinary person, so he must have done it on purpose!" He took some elixirs, too, and died temporarily. The other two disciples were unwilling to do so and left the mountain area. Immediately after that, Wei Boyang rose up and placed the elixirs he had eaten, into the mouths of the dead disciple and the white dog. Both of them came back to life, became Immortals, and left. When somebody happened to enter the mountain to gather wood, Wei wrote greeting letters and asked the villagers to send them to the two disciples, who had no regrets.
Wei Boyang wrote the Three Ways Unified and Normalized ( 參同契 Cantongqi ) in three volumes, dealing mostly with Five Agents ( 五行 Wuxing ) theory. The book appears to be a commentary on the Book of Changes ( 周易 Zhouyi ), but it is actually a treatise on making elixirs by using the Images derived from the Hexagrammatic Lines of the Book of Changes. His book deals with both Inner or meditative Alchemy ( 內丹 Neidan ) and Outer or laboratory Alchemy ( 外丹 Waidan ), and is held up as the 'Rorefather of Alchemical Scriptures' ( 丹經之祖 Danjing Zhi Zu ). Wei's thinking had a great influence on Daoist alchemy. He is generally acknowledged throughout the world as the earliest alchemist whose works are still extant.