Xú Yǎngtián 徐養恬, late-Qīng physician (CBDB 402790, dynasty 20 = Qīng, dates not specified in CBDB). Author of KR3ep066 Xú Yǎngtián fāngàn, a four-juǎn casebook with an unusual empirical-formula appendix that includes opium-quitting prescriptions — dating the work to the second half of the nineteenth century. No further securely transmitted biographical record.