蓄叶绿茎赤，禀木火之气，而引蔓促节，气味苦平，能通利三焦，搜抉隐微湿热之病
。故
金匮要略云∶浸淫疮从口流向四肢者可治，从四肢流入口者不可治。盖口为脾窍，流向
四肢，则湿热不致侮脾，脾土有权而可治。 蓄引蔓促节，复节节开花，可不谓湿热流向四
肢之象欤。
邹氏以大黄黄中通理，状如锦纹，质色深紫，为火贯土中，极服卢芷园行火用一语。窃
思卢氏论素问承制生化之义固精，但浅学不易领悟。夫大黄火贯土中，或当能扶脾阳矣，然
此其质耳。味则大苦，气则大寒，且于黄色中贯赤纹，则于脾中血分锢土之火，自当之辄息
，锢土之火息，而心君生土之火，岂有不因之而行其用，此所以行君令戡祸乱拓土地而有将
军之号也。
大黄色黄臭香，性与土比，故用于脾胃病极合。其能行火用上下表里咸到，则人多忽之
，然有一言可以蔽之者，曰荡实涤热而已。热与实兼者，如大小承气汤下燥屎，大陷胸汤丸
治结胸，抵当汤丸下瘀血，大黄附子汤治胁下偏痛；其但热不实者，如苓甘五味加姜辛半杏
大黄汤治面热如醉，茵陈蒿汤治谷疸，泻心汤治心气不足；此二者之显有区别者。推是以求
，则如鳖甲煎丸治症瘕，大黄 虫丸治虚劳羸瘦，大黄牡丹汤治肠痈，大黄黄连泻心汤治气
痞，非热实而同于热实，亦惟假荡涤之性功，扩神奇之妙用。而仲圣制剂之道，抑更有进者
焉。己椒苈黄丸，曰肠间有水气。水者虚软之物，大黄能荡实不能捣虚，且泻水已有己椒葶
苈，更益以大黄何为？或谓泄血闭而下热，或谓从大便而分消，皆意为揣摩，未足征信。独
近人唐容川云∶三焦者，决渎之官，水道出焉。三焦即膈膜油网，水从胃中四面微窍渗入油
网，从油网入膀胱。若水走肠间则为停水，水停而不行于三焦，则水不化气而津不生，是以
口舌干燥。治法宜将未入肠间之水，引之走三焦故道；既停肠间之水，从肠间而下夺。此据
西医油网之说，征以内经三焦，核之是证是方，无不吻合，实胜旧解。盖防己纹如车辐，内
黄外白，有从脾肺斡旋三焦水道之能；椒目温肾以蒸发其脾阳，除腹满而利水，犹肾气丸之
有附桂，如是而三焦之故道可复矣。肠间之水，将遂施大黄以下夺乎，抑未也？夫大肠者糟
粕所居，大肠有水，下即与糟粕俱下，虽非燥屎，大黄固与有责；特其所司全在肠胃，力不
及肺。肺合大肠，非肺出治节，不能使水食俱下。葶苈为从肺至脾之药（本邹氏疏证），利
水道兼破积聚，故加之以辅大黄之不逮。且椒得大黄，庶寒温相济，而肠胃之疾，亦必火用
行而后
夫大黄之为物有定，而用大黄之法无定。不得仲圣之法，则大黄不得尽其才而负大黄实
多，否则为大黄所误而大黄之被诬亦多。素问至真要大论，论制方之法甚备。而其间缓急奇
偶，复极之气味浓薄、制小、制大、数少、数多，参伍而错综之，实有无穷之用。仲圣则正
本此旨以制方，而不容以一端测焉。大黄气味俱浓，本峻下之物，因其峻下而微变其性以用
之，则如大承气抵当汤之大黄酒洗酒浸，以兼除太阳余邪也；大黄黄连泻心汤之大黄，以麻
沸汤渍之而不煮，欲其留恋心下也；大黄附子汤大黄与附子并用，则变寒下为温下；茵陈蒿
汤大黄与茵陈栀子并用，则不走大便而走小便；大黄用法之不同也如是。更以方剂言之，尤
氏谓小承气无芒硝而但有枳朴，下趋之势缓，故曰小。不知小承气虽有枳朴无芒硝，而枳朴
分两亦较大承气甚少，此制之大小，即承气大小所由名，岂在芒硝有无之别。且芒硝并不专
取其下趋，调胃承气芒硝与甘草并用，则能调胃，大陷胸芒硝与甘遂并用，则能陷胸；大承
气芒硝只三合，而调胃承气大陷胸转用至半升一升；调胃陷胸有芒硝，而抵当汤丸转无芒硝；
芒硝之功，不专在下趋亦明矣。柯韵伯谓药之生者，气锐而先行，熟者气纯而和缓，故大承
气以芒硝专化燥屎，大黄继通地道，而后枳朴除其痞满。邹氏韪之，其实似是而非也。芒硝
之不取乎速下，上已言之。夫多煮者味浓，少煮者味薄；味浓则下之早，味薄则下之迟。枳
朴先煮，欲其径下；消黄则兼资以涤热，非故操之不可。故大黄后纳，芒硝只一两沸。小承
气所以同煮者，枳朴既少，又无芒硝。且大承气以水一斗煮枳朴取五升，纳大黄后尚取二升；
小承气则仅水四升煮取一升二合，大黄虽与枳朴同煮，力亦不浓，何必再分先后。邹氏谓大
陷胸汤用甘遂芒硝之锐，犹恐其暂通复闭，故大黄先煮，使当善后之任。置全方配合之道不
讲，而但于先后煮讨消息。不知芒硝甘遂，专治胸间热结水结，故芒硝只一两沸，甘遂内末
而不煮；大黄本肠胃药，用以为消遂前驱，故先煮之。邹氏又谓茵陈蒿汤，大黄栀子为前茅
，茵陈为后劲。不知茵陈发扬芳郁，禀太阳寒水之气，善解肌表之湿热，欲其驱邪由小便而
去，必得多煮以浓其力。与桂枝利小便非多用不可，正复相同。大黄只二两而又后煮，则与
茵陈走肌表之气相浃，且能促之使下也。茵陈栀子皆走小便，大黄自亦不走大便矣。此仲圣
制
蓄（植物名，此处指大黄）的叶子是绿色的，茎是红色的，禀受了木和火的气化特性。它藤蔓蔓延且节间短促，气味苦而性平，能够通利三焦，搜剔并清除隐蔽细微的湿热病邪。所以《金匮要略》中说：“浸淫疮如果从口部流向四肢的可以治疗，从四肢流入口部的则不可治疗。”这是因为口是脾的窍道，病邪流向四肢，说明湿热之邪不会侵犯脾土，脾土功能正常因而可以治疗。蓄（大黄）藤蔓蔓延、节间短促，并且节节开花，这难道不是湿热之邪流向四肢的象征吗？
邹氏认为大黄中间通达理路，形状像锦纹，质地颜色深紫，这是火气贯穿土中的表现，非常佩服卢芷园“行火用”这一说法。我私下思考，卢氏论述《素问》中承制生化的意义确实精妙，但浅学之人不容易领悟。大黄色黄中通，或许能够扶持脾阳，但这只是它的质地属性。其味道是大苦，气性是大寒，且在黄色中贯穿赤色纹理，那么对于脾脏血分中固结在土中的火邪，自然应当立即平息。固结在土中的火邪平息了，心君生土的火气，怎么会不因此发挥作用呢？这就是为什么它有将军的称号，能够执行君主的命令，平定祸乱，开拓疆土的原因。
大黄色黄且有香气，药性与土相近，所以用于治疗脾胃病非常合适。它能发挥火的作用，上下表里都能到达，人们往往忽略这一点，然而可以用一句话来概括它，那就是荡涤实热而已。热与实兼有的情况，如大小承气汤攻下燥屎，大陷胸汤丸治疗结胸，抵当汤丸攻下瘀血，大黄附子汤治疗胁下偏痛；只有热而没有实的状况，如苓甘五味加姜辛半夏杏仁大黄汤治疗面部发热如醉酒状，茵陈蒿汤治疗谷疸，泻心汤治疗心气不足；这两者有明显的区别。推究这种道理以求得规律，那么如鳖甲煎丸治疗症瘕，大黄䗪虫丸治疗虚劳羸瘦，大黄牡丹汤治疗肠痈，大黄黄连泻心汤治疗气痞，这些虽然不是典型的实热证，却等同于实热证处理，也只是借助其荡涤的性质功效，扩展神奇的妙用罢了。而张仲景制剂的方法，更有进一层的深意。己椒苈黄丸，主治肠间有水气。水是虚软之物，大黄能荡涤实邪不能捣毁虚水，而且泻水已有防己、椒目、葶苈子，再添加大黄做什么呢？有人说是泄血闭而下除热邪，有人说是通过大便分消水湿，这些都是主观推测揣摩，不足以取信于人。只有近代人唐容川说：三焦是决渎之官，水道由此而出。三焦就是膈膜油网，水从胃中四面微窍渗入油网，从油网进入膀胱。如果水流入肠间则为停水，水停滞而不运行于三焦，则水不能化为气而津液不生，所以出现口舌干燥。治疗方法应该将未进入肠间的水，引导它走三焦的故道；已经停在肠间的水，从肠间向下夺去。这是依据西医关于油网的说法，验证《内经》中关于三焦的理论，核对这个病症和方剂，没有不吻合的，确实胜过旧的解释。因为防己的纹理像车轮辐条，内黄外白，有从脾肺斡旋三焦水道的能力；椒目温肾以蒸发脾阳，消除腹满并利水，就像肾气丸中有附子和桂枝一样，这样三焦的故道就可以恢复了。肠间的水，是要施用大黄来向下夺去吗？还是说尚未至此？大肠是糟粕居住的地方，大肠有水，下行时就会与糟粕一起排出，虽然不像燥屎那样坚硬，但大黄对此也有责任；特别的是它主管肠胃，力量达不到肺。肺与大肠相合，如果没有肺的治理调节，就不能使水和食物一起下行。葶苈子是从肺到脾的药物（根据邹氏疏证），既能利水道又能破积聚，所以加入它以辅助大黄力量的不足。而且椒目得到大黄，可以使寒温相互调剂，而肠胃的疾病，也必定要在火的功能发挥之后才能痊愈。
大黄作为一种药物是有固定特性的，但使用大黄的方法却没有固定模式。不得到张仲景的方法，则大黄不能尽其才而辜负大黄的情况很多，否则被大黄所误而被诬蔑的情况也很多。《素问·至真要大论》中，论述制方的方法非常完备。其中的缓急奇偶，复极的气味浓薄，制方的大小，数量的多少，参伍错综变化，实在有无穷的运用。张仲景正是本着这个宗旨来制方，不容许用单一的角度去揣测。大黄气味都浓厚，本是峻下的药物，因为它峻下而稍微改变其性质来使用它，比如大承气汤、抵当汤中的大黄用酒洗、酒浸，以兼除太阳经的余邪；大黄黄连泻心汤中的大黄，用麻沸汤浸泡而不煮，想要它留恋在心下部位；大黄附子汤中大黄与附子并用，则将寒下变为温下；茵陈蒿汤中大黄与茵陈、栀子并用，则不走大便而走小便；大黄的用法不同就是这样。再从方剂方面来说，尤氏认为小承气汤没有芒硝而只有枳实、厚朴，下趋的趋势缓慢，所以叫小。不知道小承气汤虽然有枳实、厚朴而没有芒硝，但枳实、厚朴的分量也比大承气汤少得多，这种制方的大小，就是承气汤分为大、小的由来，哪里在于有没有芒硝的区别。而且芒硝并不专门取其下趋作用，调胃承气汤中芒硝与甘草并用，就能调和胃气，大陷胸汤中芒硝与甘遂并用，就能陷破胸结；大承气汤中芒硝只用三合，而调胃承气汤、大陷胸汤反而用到半升、一升；调胃承气汤、大陷胸汤有芒硝，而抵当汤丸反而没有芒硝；芒硝的功效，不专在下趋也是显而易见的。柯韵伯说药物的生品，气锐而先行，熟品气纯而和缓，所以大承气汤用芒硝专门化解燥屎，大黄随后通地道，然后枳实、厚朴消除痞满。邹氏赞同这个观点，其实似是而非。芒硝不追求速下，上面已经说过了。煮的时间多则味道浓，煮的时间少则味道薄；味道浓则泻下早，味道薄则泻下迟。枳实、厚朴先煮，是想让它们径直达下；大黄则兼资以涤除热邪，并非故意操持不可。所以大黄后纳，芒硝只煮一两沸。小承气汤之所以同煮，是因为枳实、厚朴量少，又没有芒硝。而且大承气汤用水一斗煮枳实、厚朴取五升，纳入大黄后再取二升；小承气汤则仅用水四升煮取一升二合，大黄虽然与枳实、厚朴同煮，药力也不浓厚，何必再分先后。邹氏说大陷胸汤用甘遂、芒硝的锐利，还恐怕它们暂时通畅后又闭塞，所以大黄先煮，让它承担善后的任务。不考虑全方配合的道理，而只在煮药的先后顺序上斟酌。不知道芒硝、甘遂专门治疗胸间的热结和水结，所以芒硝只煮一两沸，甘遂研末内服而不煮；大黄本是肠胃药，用它作为甘遂的前驱，所以先煮它。邹氏又说茵陈蒿汤，大黄、栀子是前锋，茵陈是后劲。不知道茵陈发扬芳郁之气，禀受太阳寒水之气，善于解肌表的湿热，想要驱邪从小便而去，必须多煮以浓郁其药力。这与桂枝利小便非多用不可，完全相同。大黄只用二两而又后煮，则与茵陈走肌表的气机交融，并且能促进其下行。茵陈、栀子都走小便，大黄自然也不走大便了。这是张仲景制……
The leaves of *Rheum palmatum* (Dahuang, 大黄) are green and the stems are red; it inherits the qi of Wood and Fire. Its vines spread with short internodes. Its taste is bitter and its nature is neutral. It can unblock and benefit the Sanjiao (Triple Burner), searching out and eliminating damp-heat pathologies hidden in subtle areas. Therefore, *Jingui Yaolue* (Essential Prescriptions from the Golden Cabinet) states: "For impetigo (Imjin Chuang, 浸淫疮), if it starts from the mouth and flows to the four limbs, it is treatable; if it starts from the four limbs and flows into the mouth, it is untreatable." This is because the mouth is the orifice of the Spleen. When the pathology flows to the four limbs, the damp-heat does not invade the Spleen Earth. With the Spleen Earth having authority, it becomes treatable. The spreading vines and short internodes of *Rheum*, along with flowers blooming at every node, could this not be considered a manifestation of damp-heat flowing to the four limbs?
Zou believed that Dahuang has a central channel connecting its interior, resembling brocade patterns, with a deep purple color and texture, representing Fire penetrating through Earth. He greatly admired Lu Zhiyuan's phrase "executing the function of Fire." I privately ponder that while Lu's discussion on the meaning of control and generation in *Suwen* (Plain Questions) is indeed profound, shallow learners may find it difficult to comprehend. Although Dahuang's yellow color and central channel might support Spleen Yang, this refers only to its physical substance. Its taste is intensely bitter, and its nature is intensely cold. Furthermore, the red veins running through the yellow indicate that for the Fire constrained within the Earth in the Blood aspect of the Spleen, it naturally acts to extinguish it. Once the constrained Fire in Earth is extinguished, the Fire generated by the Heart Sovereign to produce Earth will inevitably act upon it. This is why it bears the title of "General," capable of executing the Sovereign's orders, quelling chaos, and expanding territory.
Dahuang is yellow and fragrant, its nature aligning with Earth, making it highly suitable for treating Spleen and Stomach diseases. Its ability to execute the function of Fire throughout the upper and lower, exterior and interior, is often overlooked. However, one sentence can summarize it: it sweeps away excess and purges heat. In cases where Heat and Excess coexist, such as using Da Chengqi Tang (Major Order the Qi Decoction) to purge dry feces, Da Xiexiong Tang/Wan (Major Trap the Chest Decoction/Pill) to treat chest binding, Didang Tang/Wan (Arrive at Blood Decoction/Pill) to purge blood stasis, and Dahuang Fuzi Tang (Rhubarb and Aconite Decoction) to treat unilateral hypochondriac pain; in cases where there is Heat but no Excess, such as using Linggan Wuwei Jiangxin Banxia Dahuang Tang (Poria, Cinnamon Twig, Licorice, Ginger, Asarum, Pinellia, and Rhubarb Decoction) for facial heat resembling drunkenness, Yinchenhao Tang (Artemisia Capillaris Decoction) for grain jaundice, and Xiexin Tang (Drain the Epigastrium Decoction) for insufficiency of Heart Qi; these two categories show distinct differences. Extending this logic, conditions like Biejia Jian Wan (Turtle Shell Building-Up Pill) for abdominal masses, Dahuang Zhechong Wan (Rhubarb and Ground Beetle Pill) for consumptive disease with emaciation, Dahuang Mudan Tang (Rhubarb and Moutan Decoction) for intestinal abscess, and Dahuang Huanglian Xiexin Tang (Rhubarb, Coptis, and Scutellaria Drain the Epigastrium Decoction) for Qi痞 (Qi obstruction), although not strictly Heat-Excess, are treated similarly to Heat-Excess. They merely borrow the sweeping and purging properties to expand miraculous applications. Zhang Zhongjing's method of formulating prescriptions goes even further. Ji Jiao Li Huang Wan (Stephania, Piper, Descurainia, and Rhubarb Pill) treats water qi in the intestines. Water is a soft/fluid substance; Dahuang can sweep Excess but cannot crush deficiency/water. Since Fangji (Stephania) and Tinglizi (Descurainia) already drain water, what is the purpose of adding Dahuang? Some claim it drains blood closure and lowers heat; others suggest it disperses via the large intestine. These are speculative guesses lacking credibility. Only the modern scholar Tang Rongchuan stated: The Sanjiao is the official responsible for irrigation, where water passages emerge. The Sanjiao corresponds to the diaphragmatic fatty network. Water seeps from the stomach through tiny pores into this network, then enters the Bladder. If water enters the intestines, it becomes stagnant water. If water stagnates and does not circulate through the Sanjiao, it fails to transform into Qi, leading to a lack of Jin-Ye (Body Fluids), causing dry mouth and tongue. The treatment should guide water that has not yet entered the intestines back to the Sanjiao pathway; and for water already stagnant in the intestines, it should be drained downward from the intestines. Based on the Western medical concept of the fatty network and verifying it against the *Neijing*'s description of the Sanjiao, this matches the syndrome and prescription perfectly, surpassing old interpretations. Fangji (Stephania) has veins like wheel spokes, yellow inside and white outside, possessing the ability to pivot the Sanjiao water pathways between the Spleen and Lung. Jiaomu (Piper Seed) warms the Kidney to evaporate Spleen Yang, removing abdominal fullness and promoting urination, similar to how Fuzi (Aconite) and Guizhi (Cinnamon Twig) function in Shenqi Wan (Kidney Qi Pill). Thus, the original pathway of the Sanjiao can be restored. Regarding the water in the intestines, should Dahuang be used to drain it downward? Or is it not yet time? The Large Intestine is the residence of waste. If there is water in the Large Intestine, it exits with the waste. Even if not dry feces, Dahuang still has a role. However, its jurisdiction lies primarily in the intestines and stomach, lacking power to reach the Lung. The Lung pairs with the Large Intestine; without the Lung's governance and regulation, water and food cannot descend together. Tinglizi (Descurainia Seed) is a herb moving from Lung to Spleen (according to Zou's commentary); it benefits water passages and breaks accumulations. Thus, it is added to assist Dahuang's insufficiency. Moreover, Jiaomu combined with Dahuang balances Cold and Warmth. Diseases of the intestines and stomach require the Fire function to operate before healing.
As an object, Dahuang has fixed characteristics, but the methods of using it are variable. Without Zhang Zhongjing's methods, Dahuang fails to fulfill its potential, leading to many instances of failing Dahuang. Conversely, misuse leads to Dahuang being blamed frequently. *Suwen: Zhi Zhen Yao Da Lun* discusses prescription formulation extensively, covering speed/slowness, odd/even combinations, intensity of flavors/natures, small/large formulations, and numerical variations. These intricate combinations offer infinite applications. Zhang Zhongjing formulated based on this principle, refusing single-dimensional interpretation. Dahuang has strong flavor and nature, originally a harsh purgative. By slightly altering its nature due to its harshness, different effects are achieved. For example, in Da Chengqi Tang and Didang Tang, Dahuang is washed/soaked in wine to address residual Shaoyang pathogens; in Dahuang Huanglian Xiexin Tang, Dahuang is steeped in boiling water without boiling to retain its action in the epigastrium; in Dahuang Fuzi Tang, combining with Fuzi changes cold purging to warm purging; in Yinchenhao Tang, combining with Yinchen and Zhizi directs action to urination rather than defecation. Such is the variability of Dahuang usage. Regarding formulas, You Shi argued that Xiaochengqi Tang (Minor Order the Qi Decoction) lacks Mangxiao (Mirabilite) and contains only Zhishi (Immature Bitter Orange) and Zhi Ke (Aurantium), resulting in a slower descending force, hence "Minor." However, Xiaochengqi Tang has less Zhishi and Zhi Ke than Da Chengqi Tang. The distinction between Major and Minor lies in the dosage/formulation, not merely the presence of Mangxiao. Mangxiao does not solely act to descend. In Tiaowei Chengqi Tang (Regulate the Stomach Order the Qi Decoction), Mangxiao combined with Gancao (Licorice) regulates the Stomach; in Da Xiexiong Tang, combined with Gansui (Kansui Root), it traps the Chest. Da Chengqi Tang uses only 3 he of Mangxiao, whereas Tiaowei and Da Xiexiong use up to half a sheng or one sheng. Didang Tang/Wan lacks Mangxiao entirely. Clearly, Mangxiao's function is not limited to descending. Ke Yunbo stated that raw herbs have sharp Qi acting first, while cooked herbs have pure Qi acting gently. Thus, in Da Chengqi Tang, Mangxiao dissolves dry feces, Dahuang follows to open the earthy pathway, then Zhishi and Zhi Ke remove fullness. Zou agreed, but this is partially correct yet fundamentally flawed. As mentioned, Mangxiao does not seek rapid purging. Longer boiling yields stronger flavor and earlier purging; shorter boiling yields weaker flavor and later purging. Zhishi and Zhi Ke are boiled first to descend directly; Dahuang is added later to assist in purging heat, not to delay intentionally. Thus, Dahuang is added last, and Mangxiao is boiled briefly. Xiaochengqi Tang boils all together because Zhishi/Zhi Ke are scant and there is no Mangxiao. Da Chengqi Tang boils Zhishi/Zhi Ke in 10 dou of water to get 5 sheng, adds Dahuang, and reduces to 2 sheng. Xiaochengqi Tang boils 4 sheng of water to get 1.2 sheng. Even if boiled together, Dahuang's strength is not intense, so separating order is unnecessary. Zou claimed that in Da Xiexiong Tang, using the sharpness of Gansui and Mangxiao risks temporary relief followed by re-obstruction, so Dahuang is boiled first to handle aftermath. Ignoring holistic formula synergy, focusing only on boiling order is misguided. Gansui and Mangxiao treat heat/water binding in the chest; thus Mangxiao is boiled briefly and Gansui is taken as powder. Dahuang, a gastrointestinal herb, acts as a vanguard for Gansui, hence boiled first. Zou also claimed that in Yinchenhao Tang, Dahuang and Zhizi are the vanguard, and Yinchen is the rear guard. This is incorrect. Yinchen promotes aromatic dispersion, inheriting Taiyang Cold-Water Qi, resolving muscle-surface damp-heat. To drive pathogens out via urine, it must be boiled longer to intensify its power, similar to Guizhi requiring larger doses for diuresis. Dahuang (only 2 liang) is added late, blending with Yinchen's surface-moving Qi and promoting downward movement. Since Yinchen and Zhizi direct to urination, Dahuang naturally avoids the large intestine. This reflects Zhang Zhongjing's formulation...