Duàn Yùcái 段玉裁 (1735–1815), zì Ruòyīng 若膺, hào Màotáng 茂堂 (also 懋堂), native of Jīntán 金壇, Jiāngsū. The most important QiánJiā philologist of the second generation and 戴震 Dài Zhèn’s senior surviving disciple. Jǔrén of Qiánlóng 25 (1760); held minor magistracies in Guìzhōu (Yùpíng 玉屏 and Wūméng 巫蒙) and Sìchuān (Fùshùn 富順, Nánxī 南谿, Wūshān 巫山) before retiring in 1781 to devote himself to scholarship. His monumental Shuō wén jiě zì zhù 說文解字注 (begun 1776, completed 1808, printed 1815) — a thirty-year commentary on Xǔ Shèn 許慎’s Shuō wén jiě zì — is the foundational work of modern Shuō wén studies and the single most influential philological monograph of the QiánJiā era. His other major works are the Liù shū yīn yùn biǎo 六書音韻表 (which divides Old Chinese into 17 phonological classes, the basis for Wáng Niànsūn’s and later phonological reconstructions); the Gǔ wén Shàngshū zhuàn yì 古文尚書撰異; the Máo Shī gǔ yīn kǎo 毛詩故音考; and the 1792 edition of his teacher’s collected works, the Dài Dōngyuán jí KR4f0053, with its accompanying Niánpǔ and fùjiào zhájì. Father-in-law of 龔自珍 Gōng Zìzhēn’s mother (Duàn’s daughter), and thus Gōng’s maternal grandfather. ECCP 782–783 (Tu Lien-che); CBDB id 58642.