The Upper Cinnabar Field
Foundations of Internal Alchemy: The Taoist Practice of Neidan, by Wang Mu, page 25
The upper Cinnabar Field, which is located at the top of the head, is also called Palace of the Muddy Pellet (niwan gong). Since the body is a microcosm, and the head corresponds to Heaven, the alchemical masters call it Palace of Qian ☰ (qiangong), with reference to the trigram that represents Heaven.
When the practice reaches the stage of “refining Essence to transmute it into Breath,” this Opening is the place where one “reverts the course of the Essence to replenish the brain” (huanjing bunao) and “eliminates the ore to keep the gold” (qukuang liujin). When it reaches the stage of “refining Breath to transmute it into Spirit,” it is the point where the Yang Spirit (yangshen) rises.
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