Xu Collection, Upper Volume Radical: Metal (jīn) Copper Kangxi strokes: 14 Page 1304, Entry 05 Pronounced tong. According to the Explaining and Analyzing Characters (Shuowen), it is red metal. According to the Collected Commentaries on Materia Medica (Bencao Jijie), there are three types of copper: red, white, and green. Red copper is found in Sichuan, Guangdong, Yunnan, and Guizhou; locals mine the mountains to extract it through smelting. White copper comes from Yunnan, and green copper comes from southern foreign states. According to the Expanded Rhymes (Guangyun), it is a category of metal. According to the Book of Former Han (Qian Han Shu), Treatise on Pitch Pipes and Calendars, the reason copper is used for making pitch pipes and measuring instruments is that copper is the most refined substance; it does not change its integrity due to dryness, moisture, cold, or heat, and does not deform due to frost, dew, wind, or rain. There is also native copper. It is also called stone marrow lead. There is also copper green. According to the Collected Commentaries on Materia Medica (Bencao Jijie), the essence of copper is air green (konglü), which is second only to air blue (kongqing). According to the Baopuzi, Gold Elixir Volume, coating one's feet with copper green prevents them from rotting when entering water. There are also place names. According to the Zuo Commentary (Zuo Zhuan), Ninth Year of Duke Cheng, he was arrested in Tongdi. The commentary notes that Tongdi was a subordinate county of the Jin state, located in the Shangdang region. According to the Book of Former Han (Qian Han Shu), Treatise on Geography, there is Tonglai County in Yizhou Commandery. There are also mountain names. According to the Book of Former Han (Qian Han Shu), Biography of Prince Bi of Wu, Wu state had Copper Mountain in Yuzhang Commandery. There are also official titles. According to the Book of Former Han (Qian Han Shu), Table of Officials, the Water Regulator (Shuiheng Duwei) had officials known as the Order and Assistant of Distinguishing Copper. The commentary notes that distinguishing copper refers to the official in charge of separating types of copper. There are also palace names. According to the Zuo Commentary (Zuo Zhuan), Thirty-first Year of Duke Xiang, the palace of Tongdi extended for several miles. The commentary notes that Tongdi was a detached palace of the Jin state. There are also names of people. According to the Book of Former Han (Qian Han Shu), Table of Ancients and Moderns, there was Tongdi Bohua. According to the Book of Former Han (Qian Han Shu), Annals of Emperor Xuan, a golden auspicious fungus with nine stems grew in the copper pool of Hande Palace. The commentary notes that a copper pool is a device under the eaves for collecting rainwater, made of copper. According to the Records of Past and Present (Gujin Zhu), the First Emperor of Qin had a famous steed named Copper Sparrow. According to the Records of the Grand Historian (Shiji), Annals of Emperor Wen, he first created copper tiger tallies with the governors and chancellors of the commanderies and kingdoms. It is also interchangeable with the character meaning cave (dòng). According to the Classic of Mountains and Seas (Shanhaijing), the mountain of Dongting. The commentary notes that for cave, some versions write it as copper. Textual Research: According to the Zuo Commentary (Zuo Zhuan), Thirty-first Year of Duke Xiang, the palace of Tongdi extended for several miles. The commentary notes that Tongdi was a detached palace of the Jin state. In accordance with the original text, the two instances of the character di (鍉) have been corrected to di (鞮).