Xu Collection, Middle Volume Radical: Rain (yǔ) Character: diàn Kangxi stroke count: 13 Page 1373, Entry 05 Ancient form. Pronounced diàn. Shuowen Jiezi (Dictionary of Explaining Graphs and Analyzing Characters): The flashing interaction of yin and yang. Composed of the radicals for rain and extended. Piya (Expository Encyclopedia): Electricity and thunder share the same essence. Thunder is formed by circling, electricity is formed by extending; yin and yang clash in rotation to create thunder, and discharge through extension to become electricity. Others say that thunder emerges from the heavens and electricity emerges from the earth, which is why electricity is derived from the earth trigram in a simplified form. Shuogua (Treatise on the Hexagrams): Fire corresponds to electricity. Electricity belongs to the element of fire. It is formed when yin and yang clash violently, causing sparks to fly; the light is electricity and the sound is thunder. Just as striking iron against stone produces fire, or throwing stone into a well produces thunder, the vast furnace of heaven and earth generates true fire through such clashes. Dong Zhongshu says: In an era of great peace, thunder does not startle people, serving only to announce and inspire; electricity does not dazzle the eyes, serving only to manifest light and glory. Shiming (Dictionary of Names): Electricity means to vanish; it appears suddenly and then is extinguished. Book of Changes (Yijing), Hexagram Shihe: Thunder and lightning combine to create order. Commentary: When thunder and lightning combine without disorder, there is order. Also, Hexagram Feng: Thunder and lightning both arrive. Subcommentary: Thunder is the terrifying movement of heaven. Electricity is the luminous manifestation of heaven. When both arrive, the majesty and clarity are sufficient to represent abundance. Book of Odes (Shijing), Lesser Odes: Thunder and lightning. Book of Rites (Liji), Monthly Ordinances: In the middle of spring, thunder begins to sound, and lightning begins to appear. Subcommentary: Electricity is the light of the sun. When yang energy is weak, the light is not visible. During this month, the yang energy grows strong and clashes with the yin, causing the light to appear, hence the phrase beginning of lightning. Spring and Autumn Annals (Chunqiu), Ninth Year of Duke Yin: Heavy rain, thunder, and lightning. Subcommentary: The Hetu (River Map) states: The collision of yin against yang creates lightning, and lightning is the light of thunder. Guliang Zhuan (Guliang's Commentary on the Spring and Autumn Annals): Thunder is the rumbling; lightning is the manifestation of the storm. Huainanzi (The Masters of Huainan), Discourse on the Original Way: Using lightning as a whip.