Minamoto Genkai 源元凱 (Edo-period Japanese kanpō 漢方 physician, late 18th century, active in Kyoto). Author of Wēnbìng zhī yánjiū / Onpyō no kenkyū 溫病之研究 (KR3eg025).
His clinical practice was reshaped by the Tenmei 8 (1788) Kyoto epidemic — the great fire of the first month of that year destroyed 100,000 households, and a warm-disease epidemic followed in the spring and summer. Standard Wú Yǒu-xìng-style treatment was failing; Minamoto turned to the Lǐngnán wèishēng fāng 嶺南衛生方 and found that fùzǐ 附子 (aconite) prescriptions could save patients who otherwise died — a finding that did not fit Wú Yǒuxìng’s framework, which held that wēnyì had no yīn-syndrome variant. The clinical evidence was the foundation of his book.
Doctrinal innovation: Minamoto and his son Tokuyō 德輿 developed a rigid-soft pathogen (剛邪 gō-ja, 柔邪 jū-ja) distinction. Both classes of pestilential pathogen lodge in the móyuán 膜原; the rigid pathogen is fierce and follows Wú Yǒuxìng’s transmission to yángmíng, the soft pathogen is sluggish and bypasses the stomach to descend directly to shàoyīn, producing the “deficiency-below, excess-above” (下虛上盈) syndrome that the 1788 epidemic exhibited — analogous to the Shānghán-tradition liǎnggǎn 兩感 (dual contraction) condition. Wú Yǒuxìng’s omission of yīn-syndromes in wēnyì, Minamoto argues, is not Wú’s fault but reflects that the soft-pathogen presentation was simply not current in Wú’s own clinical experience.
Therapeutic innovation: against Wú’s dàhuáng 大黃 (rhubarb) protocol — which Minamoto argues is dangerous in patients with lower-burner depletion — Minamoto proposes the use of melon-stalk (guādì 瓜蒂) to “search out the den” of the pathogen and drive it back out through the entry-point (mouth and nose). The principle of “out the door it came in” replaces Wú’s purgative-downward protocol.
The work was transmitted to China and included in Huáng Hàn yīxué cóngshū 皇漢醫學叢書 (Shanghai: Shìjiè Shūjú, 1936) vol. 8, ed. Tāngběn Qiúzhēn 湯本求真. Lifedates are not preserved in the readily accessible Sino-Japanese reference works.