Dragon-Tiger Elixir Reversion 龙虎还丹诀

Originally attributed to Jinlingzi, this book was compiled during the Tang Dynasty. It was recorded as a four-volume work in the General Catalog of Chongwen Library and the Tongzhi·Bibliography of the Song Dynasty. The surviving version in The Daozang is consolidated into three volumes, included in the Methods category of The Dongshen Section.

Focused on External Alchemy and gold-lead transmutation, the book identifies lead and mercury as the foundation of elixirs, also known as the Azure Dragon (Qinglong) and White Tiger (Baihu). It emphasizes that successful elixir refining first requires distinguishing true lead and true mercury, as well as understanding the properties of metals and minerals, before regulating fire for smelting.

The first volume thus begins with methods for identifying mercury and extracting mercury from cinnabar, followed by techniques for recognizing true lead. The core chapter, Secret Instructions for the Dragon-Tiger Return Elixir, states that cinnabar contains mercury—representing Yin within Yang, corresponding to the Li trigram—while black lead contains silver—representing Yang within Yin, corresponding to the Kan trigram. Only by harvesting lead and preparing mercury in accordance with the prescribed methods can the elixir be refined.

The book also records formulas for refining elixirs using cinnabar, true lead, and other medicinal materials, such as the Golden Flower Return Elixir Formula, Yellow Flower Yang Elixir Formula, and Transmutation Yang Elixir Formula. The third volume includes methods like Subduing Cinnabar into Red Silver, Green-Coagulated Red Silver, Chalcanthite Red Silver, Upper Green-Coagulated Red Silver, as well as techniques for forming cinnabar grains and removing red silver tarnish.