Mid-Táng nèidān 內丹 / waidan 外丹 alchemist (d. 825), known as Táo zhēnrén 陶真人 (“the Perfected Master Táo”). Author of [[KR5a0922|Huánjīn shù 還金術]] (DZ 922), an alchemical treatise frequently quoted by Sòng-period inner-alchemy commentators including those of [[KR5a0260|DZ 259 Táo zhēnrén nèidān fù]], [[KR5a0262|DZ 261 Jīndān fù]], and [[KR5a0266|DZ 266 Jīnyè huándān bǎiwèn jué]]. The attribution to Táo Zhí of the Nèidān fù 內丹賦 (“Ode on the Inner Elixir”) preserved at DZ 259 is, however, disputed: the anonymous commentary cites Táo’s Huánjīn shù in the third person (“Mr. Táo says…”), suggesting the commentary was not by Táo himself; on Schipper & Verellen’s analysis the commentary post-dates Táo’s death and may belong to the Five Dynasties (907–960). Táo’s Huánjīn shù and the present fù both express a transitional position between Táng waidan alchemy and the emerging Sòng nèidān synthesis: lead and mercury remain the only legitimate “ingredients,” but they are increasingly read as inner-body symbols rather than as physical metals. No CBDB record found; lifedates derive from the standard scholarly consensus following Baldrian-Hussein’s TC entries.