The Essential Secrets of Dragon and Tiger 龙虎元旨

The original text of The Essential Secrets of Dragon and Tiger (Longhu Yuanzhi) does not specify its author.

According to the postscript at the end of the text: "Master Dong Shiyuan of Mount Tai received the elixir-making method from Qingxiazi, a hermit of Mount Luofu, in the fifth year of the Zhenyuan reign (789 CE), and passed it down to Lord Cheng in the fifth year of the Kaicheng reign (840 CE)."

The Essential Secrets of Dragon and Tiger

Thus, this work is known to date from the late Tang Dynasty. Comprising one scroll, it is included in the Taixuan Section of The Daozang. The text consists of treatises and seven seven-character poetic formulas, discussing the key essentials of External Alchemy such as medicinal ingredients, refining procedures, and fire control.

The book states that "dragon and tiger" refer to lead and mercury—the core ingredients of the "Reverted Elixir" (huandan). Additionally, azurite is used as the "vital energy" (qi) and realgar as the "ministerial assistant." Mercury, cinnabar, lead, and gold correspond to the four trigrams of Zhen (☳), Li (☲), Dui (☱), and Kan (☵) respectively; all converge in the central palace of Wu-Ji Earth to produce "Yellow Sprout" (huangya), which is named the Reverted Elixir. Elixir refining must adhere to the principles of the waxing and waning of Yin and Yang and the generation and restriction of the Five Elements, aligning with the great Dao of heaven and earth. Lead and mercury, embodying the primal qi of heaven and earth, are tempered by water and fire—like stone sinking and gold floating, the "monarch" (lead) and "minister" (mercury) interact in reversal, then Yin and Yang complement each other, and monarch and minister harmonize. Furthermore, the weights of ingredients must correspond to the sixty-four trigrams, and the refining fire intensity must be determined by the waxing and waning of Yin and Yang throughout the twelve lunar months. Once the Reverted Elixir is successfully refined, consuming it enables one to live for a thousand years without death. The text extensively quotes elixir formulas from figures such as Wei Boyang, Hu Gangzi, and Qingxiazi.