Library

The seasonal climatic conditions of a year are all governed by the Twelve Earthly Branches (Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai). The Twelve Earthly Branches refer to the earthly branch directions pointed to by the Dubang (the handle of the Big Dipper), which correspond to the locations of solar terms. In the first month, the Dubang points to Yin; in the second month, to Mao; in the third, to Chen; in the fourth, to Si; in the fifth, to Wu; in the sixth, to Wei; in the seventh, to Shen; in the eighth, to You; in the ninth, to Xu; in the tenth, to Hai; in the eleventh, to Zi; and in the twelfth, to Chou. This is called "Yuejian" (Monthly Establishment). The primordial Qi of Heaven is formless and invisible, but by observing the time indicated by the Dubang, it can be known.

Among the Seven Stars of the Big Dipper, the first star is named Kui, the fifth is named Heng, and the seventh is named Biao. These three stars are collectively referred to as the "Dubang." For instance, when Yuejian is Yin in the first month, at dusk, Biao points to Yin; at midnight, Heng points to Yin; and at dawn, Kui points to Yin. The same applies to other months.

The so-called Twelve Xing (Twelve Lunar Mansions/Divisions) include Starji, Ximu, etc., totaling twelve divisions; the months indicated by the Dubao (Dipper Handle) are called the Twelve Jian; and the positions where the Sun and Moon meet are called the Twelve Chen (Earthly Branches). For example, in the month of Zi, the Sun and Moon meet at Starji, which falls within the degrees of the Niu Mansion; in the month of Chou, they meet at Xuanxiao, falling within the degrees of the Xu Mansion. The Qi of Heaven and Earth establishes itself at Zi and meets at Chou; establishes at Chou and meets at Zi; establishes at Yin and meets at Hai; establishes at Hai and meets at Yin. All twelve palaces interact in this manner, hence it is called "Liuhe" (Six Harmonies). Refer to the preceding two diagrams for comparison.

The Kui mansion extends two degrees past Xu; the Wei mansion four degrees past You; the Bi mansion seven degrees from Shen to Wei; the Jing mansion nine degrees. The Liu mansion runs four degrees past Wu; the Zhang mansion fifteen degrees returns to the Snake's head (referring to its position in the Southern Asterisms). The Zhen mansion passes ten degrees through Chen; the Di mansion two degrees through Mao; the Wei mansion three degrees reaches Yin; the Dou mansion four degrees reaches Chou. The Nu mansion enters the Zi palace at two degrees; the Wei mansion starts from the Hai palace at thirteen degrees.

The Twenty-Eight Lunar Mansions are written as "Twenty-Eight She" in the *Records of the Grand Historian* (*Shiji*). Jiao, Kang, Di, Fang, Xin, Wei, Ji constitute the Seven Eastern Mansions, corresponding to the Azure Dragon asterism, totaling seventy-five degrees. Dou, Niu, Nu, Xu, Wei, Shi, Bi constitute the Seven Northern Mansions, corresponding to the Black Tortoise asterism, totaling ninety-eight and one-quarter degrees. Kui, Lou, Wei, Mao, Bi, Zi, Shen constitute the Seven Western Mansions, corresponding to the White Tiger asterism, totaling eighty degrees. Jing, Gui, Liu, Xing, Zhang, Yi, Zhen constitute the Seven Southern Mansions, corresponding to the Vermilion Bird asterism, totaling one hundred and twelve degrees. From Fang to Bi, fourteen mansions belong to Yang and govern the day; from Mao to Xin, fourteen mansions belong to Yin and govern the night. These fixed stars do not move but respectively govern the four directions and the day and night. In total, there are one hundred and sixty-eight stars and three hundred and sixty-five and one-quarter degrees, forming the complete measure of the celestial sphere. All changes in the numbers and dynamics of Yin and Yang Qi are clearly manifested herein; physicians must not fail to understand this.