Wu Collection, Lower Volume Radical: Stone (shí) Character: Yan Kangxi strokes: 11 Page 830, Entry 08 Pronounced yan (level tone). Shuowen Jiezi (Shuowen) says: to grind. Also means to investigate thoroughly. Book of Changes (Yijing), Xici: Can investigate the concerns of the feudal lords. Also the name of a river. Commentary on the Classic of Waterways (Shuijing Zhu): The Yellow River flows northeast, passing through Yan River, which is called the Yan River water. Also the name of a pass. History of the Former Han Dynasty (Qian Hanshu), Treatise on Geography: Shangdang Commandery has the Shiyan Pass. Shigu commentary: Yan is pronounced xing. Also, according to Jiyun, pronounced nian (falling tone). Sometimes written as a variant form (yan). Guo Pu, River Rhapsody (Jiang Fu): Green moss hangs loosely upon the grinding stone. Commentary: Yan is a slippery stone. Same as an inkstone. Also, Pan Ni, Eulogy for the Offering Ceremony (Shidian Song): The essence is already refined. Commentary: Pronounced in the departing tone. Also rhymes with yin (level tone). Lu Yun, Poem presented to Minister Gu: What is their greatness? There is nothing vast left unobserved. What is their clarity? There is nothing subtle left unrefined. Note: The Shuowen Jiezi separates yan and the inkstone character into two. The Rhyme Compilation (Yunhui) and the Correct Rhymes (Zhengyun) both state that inkstone and this character are interchangeable. However, in the sense of research, the inkstone character cannot be borrowed.