Chinese sun and moon mirrors being hung round the neck, or because necks are concave things. Liu An's (c. 139 BCE) "Huainanzi" "Masters of Huainan", which is a compendium of writings from various schools of Chinese philosophy, was the first text to record "fangzhu" dew-collectors. Two "Huainanzi" chapters metaphorically use "sun and moon mirrors" to exemplify "yang" and "yin" categories and elucidate the Chinese notion of "ganying" "cosmic resonance" through which categorically identical things mutually resonate and influence each other. The "yángsuì" 陽燧 "burning-mirror" is "yang", round, and sun-like; the "fāngzhū" 方諸 "square receptacle" is "yin", square, and moon-like. The first context describes "yangsui" and
Yin and yang by a retreat, and every rise transforms into a fall. Thus, a seed will sprout from the earth and grow upwards towards the skyan intrinsically yang movement. Then, when it reaches its full potential height, it will fall. Also, the growth of the top seeks light, while roots grow in darkness. Certain catchphrases have been used to express yin and yang complementarity: Yin is the black side with the white dot in it, and yang is the white side with the black dot in it. The relationship between yin and yang is often described in terms of sunlight playing over