Formula of Red Lead into Black Lead 红铅入黑铅诀

The author of this text is unknown. Judging from its content and linguistic style, it was likely composed between the Tang and Song dynasties.

Consisting of one scroll, it is included in the Zhongshu (Various Arts) category of The Dongshen Section in The Daozang.

This work discusses External Alchemy and the art of transmuting base metals into gold (huangbai shu). Most of its content is derived from Tang-Song alchemical texts such as Secret Formulas for the Reverted Elixir at Hand (Huandan Zhouhou Jue) and Inner Book of the Jade Purity (Yuqing Neishu).

The text states: Seal red lead (i.e., cinnabar) securely in a gold box, then place it in a cauldron on a stove for refining. After ninety days, it transforms into black lead, named "Innate Lead" (Xiantian Qian). Next, place naturally occurring black lead in an ash pond to remove its "black coat," resulting in an extremely pure substance called "Nine-Refined Essence" (Jiulian Jing).

The aforementioned "Innate Black Lead" is Yin mercury, while "naturally occurring black lead" is Yang mercury: the former is extracted and refined from cinnabar, and the latter is naturally generated from cinnabar. Combine eight taels each of Yin mercury and Yang mercury, seal them in a cauldron chamber, and refine for nine months. Then, continue nurturing and refining according to the method for half a month to two years—the resulting elixir can transmute mercury into "white Dao" (a silver-like precious metal). Nurture it for three years, and it can transmute mercury into "red Dao" (gold). Nurture it for nine years, and "it can transform five metals, eight stones, gravel, and other substances into treasures while retaining their inherent qualities." Ingesting three grains grants "immortality."

The text also mentions: Seal Yin and Yang mercury in a cauldron, build an altar circle, bury it in ash, then ignite fire on the ash for refining—the resulting elixir can also transmute mercury into "white Dao."