Woodcut illustration from an edition of 1591 (19th year of the Wanli reign period of the Ming dynasty).
The eight techniques of the Spirit Tortoise are also known as the flights of the Spirit Tortoise, the eight flying techniques and the divination techniques of the Extraordinary Channels (qi jing).This is a method based on the eight points of the Eight Extraordinary Channels (qi jing ba mai), in conjunction with the alternations of the Eight Trigrams (ba gua), the Nine Palaces, and the Celestial Stems and Earthly Branches. It was used to establish the strength or weakness of the patient's blood and Qi and hence to determine the appropriate course of acupuncture for a particular day and time.
