大黄，味苦，气大寒，阴中之阴，降也，无毒。入胃与大肠。然有佐使，各经皆达也。
其性
甚速，走而不守，善荡涤积滞，调中化食，通利水谷，推陈致新，导瘀血，滚痰涎，破症结
，散坚聚，止疼痛，败痈疽热毒，消肿胀，俱各如神。欲其上升，须加酒制；欲其下行，须
入芒硝；欲其速驰，生用为佳；欲其平调，熟煎尤妙。欲其少留，用甘草能缓也。此药有勇
往直前之迅利，有推坚荡积之神功，真定安奠乱之品，祛邪救死之剂也。但用之必须看症甚
清，而后下药甚效，否则，杀人于眉睫也。夫大黄乃君主之药，故号将军。然而将军无参赞
之贤，不剿抚并用，亦勇而不仁。所以，承气汤中，必加人参、当归以助之，其他用大黄者
，未有不益之补气、补血之味也。然而，补气之药未可重加，而补血之药断宜大用。盖肠胃
燥结，而后瘀滞不行，徒用大黄以祛除，而肠中干涸，无水以通舟楫。大黄虽勇，岂能荡陆
地之舟哉。故凡有闭结，必须多用补剂，使之生血以出陈，败瘀以致新也。至于补气之药，
似乎可止，不知血必得气而易生，况大黄以祛除，未免损伤肠胃之气。吾先用参、 以补之
，气既不伤，且助大黄之力，易于推送，邪去而正又不伤，不必已下之后，再去挽回矣。
但气药可以少用者，恐过助其气，以固肠胃，则大黄有掣肘之虞。然而虚弱气怯之人，当大
黄必用之时，万不可执可用之说，减去参、 ，又虞有气脱之虑。总之，补气者，防其气脱
；补血者，防其亡阴。要在临症察之，而不便先为悬度之也。
或疑邪盛者宜泻，或用大黄至五六钱不泻者，又奈之何？噫！用大黄又不可拘泥也。邪
轻者，
少用犹须防其更变；邪重者，多用亦宜豫为图后，总以制之得宜，何忧重用乎。然而少则徐
加，多则难以收拾。故邪重者，不妨由少以增多，断不可嫌少而骤多也。
或问大黄用之于承气汤中，少若差错，下喉立亡，何利而用之乎？夫承气汤，乃夺命之
药也
。不善用之，夺命变为丧命矣。非大黄之过也。且子亦知大黄之功乎。当少腹之硬痛也，求
生不得，求死不能，一用大黄泻之，苦楚之境，忽易为快乐之场，不特腹中安然，而身躯手
足疼痛解热冤，其功之大为何如乎。倘用芒硝、浓朴、枳实，而不用大黄，虽亦能逐邪荡硬
，然必不能如是之功速而效神也。可疑其无利而不用乎。
或疑大黄功多而过亦多，予终不敢信为夺命之药而轻用之也。夫用大黄治至急之症也，
缓症
可以迟用，而急症断不宜迟。逍遥观望，因循谨慎，而杀人者正多。凡邪入下焦，而上焦喘
满、中焦痞闷者，断宜速下。倘手按之痛甚而不可按者，急下无疑，庶几可以夺命。否则，
气逆而死矣。胡可虑其亡阴之过，而不收其救阳之功哉。
或曰用大黄误下，往往致不可救，可罔顾其亡阴，单收其救阳之功乎？曰∶亡阴之祸，
乃误
下之过，非宜下之过也。宜下而不下，与不宜下而下，过正相同。倘虑误下，难于垂援，先
预防而用补剂，或投而为佐使，自无误下之愆。即误下，而亦无难急之祸，亦何至有亡阴之
失哉。
或疑大黄亦斩关夺门之将，何以又不宜用人参？大黄亦何尝不宜人参哉，第古人用人参
于大
黄中者绝少。盖用大黄之症，多是下行而不上行。上行之症，邪多裹迁之不定；下行之症，
邪有趋散之无忧。用大黄以逐邪，所以止加当归以助其势，而不用人参以防其机也。
或疑大黄逐瘀，而气弱之人，往往随下而辄亡，独不可用人参以扶其气乎？曰∶吾前言
大黄
未尝不宜人参者，正言气弱之人也。邪在于大肠之中，结燥屎而作痛，非大黄之猛利，何以
迅逐其邪，而兼去其燥屎乎，倘其人为虚弱之人，似宜和解为得。然而邪已下趋大肠，和其
中焦，而下焦更为急迫，其痛必甚，势必下之为快。然而下之，而气亦随下而俱脱也。苟不
用人参以急补其气，则气脱又何救乎。然而与其下之气脱，而后救之以人参，何不先用人参
于大黄之中，未下而先防其脱乎。况人参、大黄同用，则人参助大黄以奏功，大黄亦得人参
而缓力，但去其燥屎之邪，而不崩其虚弱之气，是两用之而得宜也。
或又问人参用于大黄之中，万一补住其邪，而燥屎不得下，不因用人参而误乎？夫大黄
走而
不
守，人参安得而留之乎。况邪又不在上、中二焦，而在下焦之大肠。邪在大肠，原宜直下，
用大黄者，不过顺以推之，而非逆以提之也。顺推而用人参，又安得变顺而转为逆乎。故人
参用之于大黄之中，万无补住其邪之祸者也。
或疑虚人不可用攻，古人有先服人参，后服大黄者，可乎？不可乎？此亦权宜之法，而
不可为
训也。愚意不若人参、大黄同用为佳。先服大黄，恐气脱而不及救；先服人参、恐邪壅而不
能攻。惟同用于一时，自然相制相宜，大黄无过攻之虞，而人参无过补之失也。
或问大黄性猛，过于迅速，似乎熟用尚非所宜，何以古人不尚熟而尚生乎？夫人黄过煮，
则
气味全散，攻毒不勇，攻邪不急，有用而化为无用矣。大黄之妙，全在生用为佳。将群药煎
成，再投大黄，略煎一沸即服，功速而效大，正取其迅速之气而用之也。不可畏其猛烈，过
煎煮以去其峻利也。
大黄，味苦，气大寒，属于阴中之阴，主降，无毒。归入胃经与大肠经。然而若有佐使药配合，各经皆可到达。
大黄的药性非常迅速，走窜而不固守，善于荡涤积滞，调理中焦、消化饮食，通利水谷，推陈出新，引导瘀血，滚动痰涎，破除症结，消散坚聚，止住疼痛，败坏痈疽热毒，消除肿胀，功效都神奇无比。想要它向上行，必须加酒炮制；想要它向下行，必须加入芒硝（Sal Niter）；想要它快速驰骋，生用为佳；想要它平和调治，熟煎尤其奇妙。想要它在体内稍作停留，使用甘草可以缓和药性。此药有勇往直前的迅利，有推倒坚硬、荡涤积滞的神奇功效，真是安定平定混乱的佳品，祛除邪气、挽救死证的药剂。但是使用它必须看清病症非常清楚，然后下药才很有效，否则，就在眉睫之间就会杀人。大黄是君主之药，所以号称将军。然而将军如果没有参赞的贤能，不采用剿灭和安抚并用的策略，也是勇猛而不仁慈。所以，在承气汤中，必须加入人参、当归来辅助它，其他使用大黄的地方，没有不增益补气、补血药物的。然而，补气药不可重加，而补血药断然应该大用。因为肠胃燥结，导致瘀滞不行，如果只用大黄来祛除，而肠中干涸，没有水来通舟楫。大黄虽然勇猛，难道能荡涤陆地上的船吗？所以凡是有关闭闭塞的情况，必须多用补剂，使之生血以排出陈旧之物，败除瘀血以致新血生成。至于补气药，似乎可以停止不用，不知道血必须得到气才能容易生成，况且大黄用于祛除病邪，未免损伤肠胃之气。我先用参、[此处原文缺字，推测为芪或类似补气药]来补益它，气既不被损伤，且帮助大黄的力量，易于推送，邪气去除而正气又不受伤，不必在已经泻下之后，再去挽回。但气药可以少用的原因，是恐怕过助其气，从而固护肠胃，那么大黄就有被牵制的忧虑。然而对于虚弱气怯的人，在大黄必须使用的时候，万万不可执着于“可用”的说法，减去参、[缺字]，又担心有气脱的顾虑。总之，补气是为了防止气脱；补血是为了防止亡阴。关键在于临证时仔细考察，而不便事先凭空揣度。
有人怀疑邪气盛者宜泻，或者使用大黄至五六钱却不泻下的情况，该怎么办呢？唉！使用大黄又不可拘泥。邪气轻的，少用尚须防备病情变化；邪气重的，多用也应当预先谋划后续治疗，总之以控制得当为宜，何必担忧重用呢？然而量少则慢慢增加，量多则难以收拾。所以邪气重的，不妨由少逐渐增多，断不可嫌少而骤然增多。
有人问：大黄用在承气汤中，稍微差错，入口立刻死亡，有什么利益而使用它呢？承气汤，是夺命之药啊。不善于使用它，夺命就变成了丧命。这不是大黄的过错。况且你也知道大黄的功用吗？当小腹部硬痛时，求生不得，求死不能，一旦使用大黄泻下，痛苦之境，忽然变为快乐的场所，不仅腹中安然，而且身躯手足的疼痛、发热冤屈都解除了，它的功劳之大是怎样的呢？倘若使用芒硝、厚朴、枳实，而不用大黄，虽然也能驱逐邪气、荡涤硬结，但必然不能像这样功效迅速且神奇。难道可以怀疑它没有利益而不使用吗？
有人怀疑大黄功劳多而过失也多，我始终不敢相信它是夺命之药而轻易使用它。夫使用大黄治疗最紧急的病症，缓症可以迟用，而急症断然不宜迟。逍遥观望，因循谨慎，而杀人的往往正是这些人。凡是邪气进入下焦，而上焦喘满、中焦痞闷的，断然应该速下。倘若手按之疼痛严重且不可按压的，急下无疑，这样才能夺命。否则，气逆而死。怎么可以忧虑亡阴的过失，而不收取救阳的功效呢？
有人说：使用大黄误下，往往导致不可救治，难道可以不顾亡阴，单收救阳之功吗？回答说：亡阴的祸患，是误下的过错，不是宜下者的过错。宜下而不下，与不宜下而下，过错正相同。倘若忧虑误下，难于救援，先预防而使用补剂，或者投作为佐使，自然没有误下的罪愆。即使误下，也没有难以急救的祸患，又何至于有亡阴的失误呢？
有人怀疑大黄也是斩关夺门的将领，为什么又不宜用人参？大黄何尝不宜用人参呢？只是古人将人参用在大黄中的极少。大概使用大黄的病症，多是下行而不上行。上行的病症，邪气多有裹挟迁延的不定；下行的病症，邪气有趋散而无忧。使用大黄以驱逐邪气，所以只加当归以助其势，而不用人参以防其机变。
有人怀疑大黄逐瘀，而气弱之人，往往随之下行而辄亡，难道独独不可用人参来扶助其气吗？回答说：我前面说大黄未尝不宜人参，正是针对气弱之人而言。邪气在于大肠之中，结燥屎而作痛，如果不是大黄的猛烈锐利，怎么能迅速驱逐邪气，同时去除燥屎呢？倘若此人是为虚弱之人，似乎适宜和解为得法。然而邪气已下趋大肠，和解其中焦，而下焦更为急迫，其疼痛必定严重，势必以下行为快。然而下行之时，气也随之俱脱。如果不用人参来急补其气，那么气脱又如何救治呢？然而与其在下行后气脱，然后再用人参救治，何不先用人参在大黄之中，未下之前先防止气脱呢？况且人参、大黄同用，则人参帮助大黄奏效，大黄也得到人参而缓和药力，只去除燥屎之邪，而不崩泄虚弱之气，这是两用而得其宜。
有人又问：人参用在大黄之中，万一补住了邪气，而燥屎不得下行，不因人参而误事吗？夫大黄走窜而不固守，人参怎么能留住它呢？况且邪气又不在上、中二焦，而在下焦的大肠。邪气在大肠，原宜直下，使用大黄，不过是顺势推之，而非逆势提之。顺势推而用人参，又怎能变顺转为逆呢？所以人参用在大黄之中，万无补住邪气的祸患。
有人怀疑虚人不可用攻伐之法，古人有先服人参，后服大黄的，可以吗？不可以吗？这也是权宜之法，而不可作为典范。我的意见不如人参、大黄同用为佳。先服大黄，恐怕气脱而不及救治；先服人参，恐怕邪气壅滞而不能攻伐。只有同用于一时，自然相互制约相宜，大黄无过攻的忧虑，而人参无过补的失误。
有人问：大黄性猛，过于迅速，似乎熟用尚非所宜，为什么古人不崇尚熟用而崇尚生用呢？夫人黄经过煮，则气味全散，攻毒不勇猛，攻邪不急切，有用而化为无用。大黄的妙处，全在生用为佳。将群药煎成，再投入大黄，略煎一沸即服，功效迅速且宏大，正是取其迅速之气而使用它。不可畏惧其猛烈，过度煎煮以去除其峻利。
Rhubarb (Da Huang), bitter in taste, cold in nature, belonging to Yin within Yin, descending in action, non-toxic. It enters the Stomach and Large Intestine meridians. However, with appropriate adjuvant drugs (Zuo Shi), it can reach all meridians.
Its nature is extremely rapid, moving without staying, good at scouring accumulation and stagnation, regulating the Middle Jiao, transforming food, unblocking water and grain, pushing out the old and generating the new, guiding blood stasis, rolling up phlegm-saliva, breaking mass formations, dissipating hard accumulations, stopping pain, defeating heat-toxin of carbuncles and sores, reducing swelling; its efficacy is miraculous in all these aspects. To make it ascend, it must be processed with wine; to make it descend, Sal Niter (Mang Xiao) should be added; for rapid action, raw use is best; for mild regulation, decocted use is excellent. To make it stay slightly longer in the body, Licorice Root (Gan Cao) can be used to moderate its effect. This herb possesses the swiftness of charging forward and the divine merit of pushing down hardness and scouring accumulation; it is truly a product that stabilizes chaos, and a formula that dispels evil and saves lives. However, when using it, one must clearly diagnose the condition before administering the drug to ensure efficacy; otherwise, it may kill within moments. Rhubarb is a sovereign drug, hence nicknamed "General". Yet, a General without the wisdom of an advisor who combines suppression and pacification is brave but not benevolent. Therefore, in Chengqi Tang (Cinnamon Twig and Rhubarb Decoction), Ginseng Root (Ren Shen) and Angelica Sinensis Root (Dang Gui) must be added to assist it. In other formulas containing Rhubarb, tonifying Qi and Blood herbs are invariably added. However, Qi-tonifying herbs should not be heavily dosed, whereas Blood-nourishing herbs should be used generously. Because dryness and constipation in the intestines lead to stagnation, if only Rhubarb is used to purge, the intestines will remain dry, lacking fluid to float the boat. Although Rhubarb is brave, how can it navigate a boat on land? Thus, in cases of closure and constipation, one must use more tonifying agents to generate blood, expel the old, and eliminate stasis to promote the new. As for Qi-tonifying herbs, they might seem dispensable, but one must realize that Blood requires Qi to be generated easily. Moreover, since Rhubarb purges, it inevitably damages the Qi of the Stomach and Intestines. By first using Ginseng [and likely Astragalus] to tonify, the Qi is not damaged, and it assists Rhubarb's power, facilitating the expulsion of pathogens while preserving healthy Qi, eliminating the need to rescue after purgation. The reason Qi-tonifying herbs can be used sparingly is to avoid over-assisting Qi, which might consolidate the intestines and hinder Rhubarb's action. However, for those with weak constitution and timid Qi, when Rhubarb is necessary, one must not adhere to the notion that it is "safe" to reduce or omit Ginseng [and Astragalus], lest there be concern about Qi collapse. In summary, tonifying Qi prevents Qi collapse; nourishing Blood prevents Yin exhaustion. The key lies in careful examination during clinical practice, rather than arbitrary speculation beforehand.
Some may doubt: If pathogens are abundant, purging is indicated; what if five or six qian of Rhubarb fail to induce purgation? Alas! One must not be rigid in using Rhubarb. For light pathogens, even a small dose requires vigilance against changes; for heavy pathogens, a large dose requires advance planning for subsequent treatment. As long as control is appropriate, why worry about heavy dosage? However, starting low allows gradual increase, whereas starting high is difficult to manage. Therefore, for heavy pathogens, it is acceptable to increase gradually from a small dose, but never to suddenly increase due to impatience with small doses.
Someone asks: In Chengqi Tang, a slight error in using Rhubarb leads to immediate death upon ingestion. What benefit justifies its use? Chengqi Tang is a life-snatching medicine. Misuse turns life-saving into life-destroying. This is not Rhubarb's fault. Do you know Rhubarb's merits? When there is hardness and pain in the lower abdomen, where one cannot seek life nor accept death, once Rhubarb is used to purge, the realm of suffering suddenly becomes a place of joy. Not only does the abdomen become peaceful, but pain, fever, and distress in the body, limbs, and extremities are resolved. How great is its merit? If Sal Niter, Magnolia Bark (Hou Po), and Immature Bitter Orange (Zhi Shi) are used without Rhubarb, although they can also drive out pathogens and dissolve hardness, they certainly cannot achieve such speed and miraculous efficacy. Can one doubt its utility and refrain from using it?
Some suspect that Rhubarb has many merits but also many faults, and I ultimately do not believe it is a life-snatching drug to be used lightly. Using Rhubarb treats critical conditions; chronic conditions can wait, but critical ones must not be delayed. Hesitating, being cautious through inertia, often leads to death. When pathogens enter the Lower Jiao, causing wheezing and fullness in the Upper Jiao and stuffiness in the Middle Jiao, rapid purgation is essential. If pressing causes severe pain that cannot be tolerated, urgent purgation is unquestionable, which can save life. Otherwise, rebellious Qi leads to death. How can one fear the fault of Yin exhaustion while ignoring the merit of saving Yang?
It is said that erroneous purgation with Rhubarb often leads to incurable states; can we ignore Yin exhaustion and only focus on saving Yang? I reply: The disaster of Yin exhaustion is the fault of erroneous purgation, not of indicated purgation. Failing to purge when indicated is equivalent in fault to purging when not indicated. If one fears erroneous purgation and difficulty in rescue, one should preventively use tonifying agents or add them as adjuvants, avoiding the sin of erroneous purgation. Even if purgation is erroneous, there is no difficult emergency, let alone Yin exhaustion.
Some doubt: Rhubarb is like a general breaching gates; why is Ginseng not suitable? Rhubarb is indeed compatible with Ginseng, but ancients rarely combined them. Conditions requiring Rhubarb usually involve downward movement rather than upward. Upward-moving pathogens are unpredictable; downward-moving pathogens disperse safely. When using Rhubarb to expel pathogens, Angelica Sinensis Root (Dang Gui) is added to boost momentum, while Ginseng is omitted to prevent interference.
Some doubt: Rhubarb removes stasis, yet people with weak Qi often die following purgation. Why not use Ginseng to support Qi? I stated earlier that Rhubarb is compatible with Ginseng, specifically for those with weak Qi. Pathogens in the Large Intestine cause pain due to dry feces. Without Rhubarb's potency, how can pathogens be swiftly expelled and dry feces removed? If the patient is weak, harmonization seems appropriate. However, since pathogens have moved to the Lower Jiao, harmonizing the Middle Jiao makes the Lower Jiao situation more urgent, increasing pain. Purging brings relief. But purging causes Qi to collapse simultaneously. If Ginseng is not used urgently to tonify Qi, how can collapsed Qi be rescued? Rather than rescuing collapsed Qi with Ginseng after purgation, why not combine Ginseng with Rhubarb beforehand to prevent collapse? When used together, Ginseng aids Rhubarb's efficacy, while Rhubarb moderates Ginseng's strength. Only dry feces are removed without depleting weak Qi, achieving harmony between the two.
Another question: If Ginseng is combined with Rhubarb, could it trap the pathogen, preventing the passage of dry feces, thus causing error due to Ginseng? Rhubarb moves without staying; how can Ginseng retain it? Moreover, the pathogen is not in the Upper or Middle Jiao, but in the Large Intestine of the Lower Jiao. Pathogens in the Large Intestine should be directed downward. Using Rhubarb is merely assisting this downward direction, not opposing it. Assisting downward movement with Ginseng cannot reverse the flow. Thus, combining Ginseng with Rhubarb poses no risk of trapping pathogens.
Some doubt: Weak patients should not undergo attack therapies. Ancients sometimes had patients take Ginseng first, then Rhubarb. Is this acceptable? No. This is a temporary expedient, not a standard. I suggest combining Ginseng and Rhubarb simultaneously. Taking Rhubarb first risks untreatable Qi collapse; taking Ginseng first risks pathogen congestion preventing attack. Using them together ensures mutual restraint and compatibility: Rhubarb avoids excessive attacking, and Ginseng avoids excessive tonifying.
Someone asks: Rhubarb is potent and rapid; cooked use seems inappropriate. Why did ancients prefer raw over cooked? Over-cooking Rhubarb disperses its aroma and flavor, making it less vigorous in detoxification and less urgent in expelling pathogens, rendering it useless. The brilliance of Rhubarb lies in raw use. After decocting other herbs, add Rhubarb, boil briefly, and serve. This yields rapid and significant effects, utilizing its swift nature. Do not fear its potency by over-decocting to remove its harshness.