"Bathing" ( 沐浴 muyu ) is a term of the science of the Golden Elixir ( 金丹 jindan ). The word "bathing" originally means washing one’s hair and body, or to use a common expression, taking a bath. The ancients had to bathe before holding a religious ritual or participating in an important activity to show their seriousness. To bathe in medicinal liquid was a traditional way of breathing in ancient times. Daoist practitioners of Outer Alchemy ( 外丹 waidan ) compare the treatment of elixir drugs to bathing. The Collection on Daoist Internal Alchemy ( 庚道集 gengdao ji ) records the way of steeping and washing red lead in medicinal liquid. The term "Bathing" was later introduced into the process of Inner Alchemy cultivation. As far as Inner Alchemy cultivation is concerned, bathing refers to the skill of mitigating the Fire Phases ( 火候 huohou ) to purify the heart and get rid of thoughts. Specifically speaking, it means to avoid restless thoughts while guiding the true Vital Breath ( 氣 qi ) and running the "River Chariot" ( 河車 heche ). Inner Alchemists hold that the six Yang Vital Breaths in the human body ascend the Du channel, reaching the acupoint of the perineum at the Zi hour and that of Jiaji at the Mao hour; and that the six Yin Vital Breaths descend through the Ren channel, reaching the Niwan palace at the Wu hour and the Yellow Court ( 黃庭 huangting ) at the You hour. Bathing should take place at the Mao and You hours. The key to the bathing of the back ascent is to rest the spirit at the acupoint of Jiaji, simply inhale and stop, without increasing or running fire; while the key to the bathing of the front descent is to rest the spirit at the Yellow Court ( the middle Elixir Field ( 丹田 dantian )), simply exhale and stop, also without increasing or running the fire. One can find symbolic indications of Bathing in Inner Alchemy masterpieces, such as On Realizing Perfection ( 悟真篇 wuzhen pian ) by Zhang Boduan and the Rootless Tree ( 無根樹 wugen shu ) by Zhang Sanfeng. Read them carefully, and you may gain a good deal of enlightment.