即马兜铃根
辛苦微寒，无毒。
发明 青木香苦寒香细，入足少阴。善降阴气上逆，故治风湿，葳蕤汤用之，并治痈肿
痰结气凝诸痛。《唐本》治热肿蛇毒，水磨敷之。《肘后》治蛊毒，酒水和煎服之，毒从小
便出。昔人言，多服令人吐利，肺寒咳嗽，寒痰作喘，胃虚畏食人勿服，以其辛香走窜也。
苦寒，无毒。《大明》曰温。
发明 预知子专杀虫疗蛊，其治 癖蛇毒，总是杀虫之功。相传取子二枚，缀衣领上，
遇有蛊毒则闻其子有声，故名预知，蜀人极贵重之。
苦辛温，有毒。东垣云辛热有毒。有黑白二种，名黑丑、白丑，凡用生磨取头末
。
发明 牵牛专一行水峻下之剂。白者属金利肺，治上焦痰饮，除壅滞气逆，通大肠风秘
，除气分湿热。黑者属水，泻肾而兼泻脾胃之湿，消肿满香港脚，利大小便秘。但病在血分，
或病稍弱而痞满者，不可用。东垣云∶牵牛非神农药也。《名医续注》云∶味寒能除湿气，
利小便，治下注香港脚，此说气味、主治俱误。凡用牵牛，少则动大便，多在泄下如水，乃泻
气之药。其味辛辣，久嚼猛烈雄壮，所谓苦寒安在哉。夫湿者，水之别称，有形者也。若受
湿气不得施化，致大小便不通，宜暂用之。况牵牛止能泄气中之湿热，不能除血中之湿热，
每见酒食过伤病痞者，多服牵牛散取快一时，药过仍痞，以致久服脱人元气，犹不知悔也。
东垣治下焦虚肿，天真丹用牵牛，以盐水炒黑，佐沉香、杜仲、补骨脂、官桂诸药，深得补
泻兼施之妙用，方见《医学发明》。
It is the root of *Aristolochia debilis* (Madouling).
Bitter and acrid, slightly cold, non-toxic.
[Invention/Commentary] Qingmuxiang (Qingmuxiang, 青木香) is bitter, cold, and finely aromatic; it enters the Foot Shaoyin channel (Kidney meridian). It excels at descending rebellious Yin qi, thus treating wind-dampness; it is used in Weirui Tang (Weirui Decoction). It also treats various pains caused by carbuncles, swelling, phlegm nodules, and qi stagnation. The *Tang Bencao* (Compendium of Materia Medica of the Tang Dynasty) records its use for treating hot swelling and snake venom: ground with water and applied externally. The *Zhouhou Beiji Fang* (Emergency Prescriptions Kept Up the Sleeve) records its use for treating gu poison: decocted with wine and taken orally, expelling the toxin through urination. Ancients stated that excessive intake causes vomiting and diarrhea; it should not be used by those with lung-cold cough, asthma due to cold-phlegm, or gastric deficiency with poor appetite, due to its acrid-aromatic penetrating nature.
Bitter, cold, non-toxic. *Daming Bencao* (Ri Hua Zi's Materia Medica) describes it as warm.
[Invention/Commentary] Yuzhizi (Premonitory Fruit / *Akebiae Fructus*) specializes in killing parasites and treating gu poison. Its treatment of pi accumulation (abdominal masses) and snake venom relies entirely on its parasiticidal efficacy. Legend has it that if two fruits are pinned to the collar, they make a sound when gu poison is present, hence the name "Yuzhi" (Premonitory); people in Shu highly value it.
Bitter and acrid, warm, toxic. Li Dongyuan states it is acrid, hot, and toxic. There are black and white varieties, named Heichou (Black Chou) and Baichou (White Chou). When used, they must be raw, ground, and the finest powder collected.
[Invention/Commentary] Qianniu (Morning Glory Seed / *Pharbitidis Semen*) is a potent agent for promoting urination and drastic purgation. The white variety corresponds to Metal and benefits the Lung; it treats phlegm-fluid retention in the Upper Jiao, removes stagnant rebellious qi, unblocks wind-constipation of the Large Intestine, and clears damp-heat from the Qi level. The black variety corresponds to Water; it drains the Kidney and simultaneously drains dampness from the Spleen and Stomach, reducing edema and fullness, treating Hongxiangjiao (Hongxiangjiao, 香港脚 / Beriberi), and promoting urination and bowel movements in cases of constipation. However, it should not be used if the disease is in the Blood level, or if the patient is slightly weak with abdominal fullness/stagnation. Li Dongyuan said, "Qianniu is not an immortal herb of Shennong." The *Xu Zhu* (Continued Annotations of Famous Physicians) states, "Its flavor is cold, able to remove dampness and promote urination, treating lower-injecting Hongxiangjiao"; this statement regarding its flavor and indications is incorrect. Whenever Qianniu is used, a small dose moves the bowels, while a large dose causes watery diarrhea; it is a drug that drains Qi. Its flavor is pungent and spicy, intensely strong when chewed for a long time; where is the bitterness and coldness? Dampness is another term for water and is a tangible substance. If one contracts dampness that fails to transform and diffuse, leading to obstruction of urination and defecation, temporary use is appropriate. Moreover, Qianniu can only drain damp-heat from the Qi level but cannot remove damp-heat from the Blood level. It is often seen that patients with abdominal fullness due to overindulgence in alcohol and food take Qianniu San (Morning Glory Powder) for momentary relief; after the effect wears off, the fullness remains, yet they continue to take it long-term, depleting their Yuan Qi without regret. Li Dongyuan treated lower Jiao deficient edema using Tianzhen Dan (Tianzhen Pill), which includes Qianniu stir-fried with salt water until black, assisted by Chenxiang (Aquilariae Lignum Resinatum), Duzhong (Eucommiae Cortex), Buguzhi (Psoraleae Fructus), and Guigui (Cinnamomi Cortex), achieving the subtle utility of combining tonification and purgation. This formula is found in *Yixue Faming* (Medical Discoveries).