Hymns on Dragon-Tiger Elixir Reversion 龙虎还丹诀颂

Compiled by Taoist Lin Taigu in the early Northern Song Dynasty with annotations by Gushenzi, this work consists of one volume and is included in the Taixuan Section of The Daozang.

This book collects sixty-four seven-character quatrains titled Odes to the Secret Instructions for the Return Elixir by Lin Taigu, which expound the essentials of External Alchemy. It states that the core of the Return Elixir lies in the Splendid Pond (Huachi), and the foundation of medicinal materials relies solely on the Dragon and Tiger—referring to lead and mercury. Taking the mutual interaction of Dragon and Tiger as medicine, one extracts Yang from Yin, restores Yin essence to its origin, and achieves the mutual resonance of Yin and Yang to form the great medicine. Ingesting it allows people to transcend the mortal world and attain immortality through rebirth.

During refining, one must emulate the Qian and Kun trigrams to regulate fire and water. The subtle mysteries lie "in the mutual reuse of Kan and Li trigrams"—the process is completed after a thousand days of refinement, and the elixir is formed. The book eulogizes the refining process and key points from the first month to the tenth month through poetic formulas. It also repeatedly urges the world to abandon fame and fortune, pursue profound truths, and refine elixirs. Gushenzi’s annotations are concise and clear, with numerous citations from Wei Boyang, Yuanyangzi, Qingxiazi, Zhenren Tao, and others. It can be inferred that this Gushenzi was also a figure of the early Northern Song Dynasty.

The alchemical theory here aligns with the Yin and Yang and trigram principles central to Taoist thought, reflecting the systematic inheritance of alchemical traditions from previous dynasties in the early Song Dynasty.