考之抵当汤证有发狂之象，桃核承气汤证有如狂之状，此皆血热影响于脑神经之明证。故用药总不离乎稍黄，无非脱胎于承气汤，深足长思也。然肠热有易犯脑者，有不易犯脑者，则其人之神经脆弱与否殊为一大主因，要以脆弱者易被犯，如本案所载者是，其理极显。又小儿神经脆弱，故惊阙之病特多。
曹颖甫曰：阳明证之头痛，其始则在阙上，甚则满头皆痛，不独承气汤证有之，即白虎汤证亦有之。且阳明府实证燥气上冲，多致脑中神经错乱，而见谵语头痛。或反在大便之后，无根之热毒上冒，如大便已、头卓然而痛、可证也。惟肠中有湿热蕴蒸，其气易于犯脑，为水气易于流动，正如汤沸于下，蒸气已腾于上，不似燥矢之凝结必待下后而气乃上冲也。此证但下浊水，即可证明温热之蕴蒸阳明。不然，目中不了了，无表里证，大便难，身微热者，何以法当急下乎？
大承气汤证其三
予尝诊江阴街肉庄吴姓妇人，病起已六七日，壮热，头汗出，脉大，便闭，七日未行，身不发黄，胸不结，腹不胀满，惟满头剧痛，不言语，眼张，瞳神不能瞬，人过其前，亦不能辨，证颇危重。余曰：目中不了了，睛不和，燥热上冲，此《阳明篇》三急下证之第一证也。不速治，病不可为矣。于是遂书大承气汤方与之。
大黄四钱枳实三钱川朴一钱芒硝三钱并嘱其家人速煎服之，竟一剂而愈。盖阳明燥气上冲颠顶，故头汗出，满头剧痛，神识不清，目不辨人，其势危在顷刻。今一剂而下，亦如釜底抽薪，泄去胃热，胃热一平，则上冲燥气因下无所继，随之俱下，故头目清明，病遂霍然。非若有宿食积滞，腹胀而痛，壮热谵语，必经数剂方能奏效，此缓急之所由分。是故无形之气与有形之积，宜加辨别，方不至临诊茫然也。
【按】余尝见一男子病者，神志恍惚，四肢痉厥，左手按额上，右于按其阴器，两足相向弯曲而崛起。傍人虽用大力，不能使之直伸，目张而赤，近光则强闭，脉凌乱隐约，大便多日不行，数日来头痛，病起仅七八日，服药五六日，即至如此地步，据谓前曾宿娼患疮，外治而愈。余曰：此大承气证失治者也。顾口噤药不能下，替者用简便法，纳甘油锭于其肛中，凡三次，毫无效验。惜无亲人作主，不能试胆导法。次日汗出、夜毙，是可悯也。又一男子病者感病数日，腹中徽痛，医以四逆散作汤与之，痛略差，而目中之不了了更显。与之言，半是半非，其夜即毙。
由上实验证之，目中不了了，睛不和，确为至危至急之候，虽伤寒不过六七日，无表里证，身但微热，大便但难而不结，即为实，当急下之，宜大承气汤。
仲圣笔之于论，同甚明了也。果能治之得法，获效亦捷，如本案所示者是。
目中不了了，睛不和，即为脑病之外征。外见目疾，内实脑病，较之上案所言仅满头剧痛者，其病为更胜一筹，其情为更急一等，其方药分量当更重若干，而治无第二法门，舍大承气莫属也。虽然，大论又曰：伤寒，若吐，若下后，不解，不大便五六日，上至十余日，日晡所发潮热，不恶寒，独语，如见鬼状，若剧者，发则不识人，循衣摸床，惕而不安，微喘，直视，脉弦则生，涩者死，微者，但发热谵语者，大承气汤主之。可见脑神经病至于不识人，至于独语如见鬼状，至于循衣摸床，至于脉涩，其微者大承气汤尚可得而主之，其剧者纵投本汤，亦无效矣。试推求其无效之故安在，曰：大承气但能治肠热之病源，不能治神经之病所，病源虽去，而病所燎原之势已成，诸神经悉受烧灼，故外见种种恶状，卒致不救也。然则当此时也，将何药以救之乎？曰：有之，其惟羚羊角乎。《本草纲目》曰：本品平肝舒筋，定风安魂，散血下风，辟恶解毒，治子癎痉疾云云。所谓恶者，毒者，因热而生也，所谓肝者，筋者，即指神经也。热毒熏灼神经，则见痉挛抽搐，是即所谓肝风动阳。羚羊角能凉和神经，使之舒静，故用之得法合量，可以治大承气所不能治之证。他药如石决、钩钩、蝎尾、蜈蚣，皆可以为佐。
曹颖甫曰：恽铁樵治王鹿萍子脑膜炎，用羚羊角犀角奏效，此王鹿萍子亲为予言之。证以佐景所言，益复可信。足见治危急之证，原有经方所不备，而借力于后贤之发明者，故治病贵具通识一也。
大承气汤证其四
陈姓少年住无锡路矮屋，年十六，幼龄丧父，惟母是依，终岁勤劳，尚难一饱。适值新年，贩卖花爆，冀博微利。饮食失时，饥餐冷饭，更受风寒，遂病腹痛拒按，时时下利，色纯黑，身不热，脉滑大而口渴。家清寒，无力延医。经十余日，始来求诊。察其证状，知为积滞下利，遂疏大承气汤方，怜其贫也，并去厚朴。计大黄四钱，枳实四钱，芒硝二钱。书竟，谓其母曰：倘服后暴下更甚于前，厥疾可瘳。其母异曰：不止其利，反速其利，何也？余曰：服后自知。果一剂后，大下三次，均黑粪，干湿相杂，利止而愈。此《金匮》所谓宿食下利，当有所去，下之乃愈，宜大承气汤之例也。
【按】大论曰：少阴病，自利清水，色纯青，心下必痛，口干，咽燥者，急下之。宜大承气汤。可以互证。《温疫论》曰：热结傍流者，以胃家实，内热壅闭，先大便闭结，续得下利，纯臭水，全然无粪，日三四度，或十余度，宜大承气汤，得结粪而利止。服汤不得结粪，仍下利，并臭水，及所进汤药，因大肠邪胜，失其传送之职，知邪犹在也，病必不减，宜更下之。延陵吴又可先贤能言此，诚不愧为仲圣之入室弟子矣。
客曰：仲景论伤寒，又可论温疫，子乌可混而一之？曰：吁！是何言也？仲圣曰：观其脉证，知犯何逆，随证治之。吾中医之长处，即在能识此证字，苟察病者所犯为大承气汤证，则投以大承气汤，所犯为四逆汤证，则投以四逆汤，服汤已，其效若响斯应，则其前病之何名，初可勿拘拘也。
大承气汤证其五
《伤寒论》曰：厥应下之，而反发汗者，必口伤烂赤。按寒郁于外，热伏于里，则其证当俟阳热渐回而下之，俾热邪从下部宣泄，而病愈矣。若发其汗，则胃中液涸，胆火生燥，乃一转为阳明热证，为口伤烂赤所由来。此正与反汗出，而咽痛，喉痹者，同例。由其发之太过，而阳气上盛也。此证余向在四明医院亲见之。其始病，余未之见，及余往诊，已满口烂赤。检其前方，则为最轻分量之桂枝汤，案中则言恶寒。夫病在太阳而用桂枝，虽不能定其确当与否，然犹相去不远。既而病转阳明，连服白虎汤五剂，前医以为不治。老友周肖彭属余同诊。问其状，昼则明了，暮则壮热，彻夜不得眠。夫营气夜行于阳，日暮发热属血分，昼明夜昏与妇人热入血室同。热入血室用桃核承气，则此证实以厥阴而兼阳明燥化。病者言经西医用泻盐下大便一次，则中夜略能安睡。诊其脉，沈滑有力。余因用大承气汤，日一剂，五日而热退。肖彭以酸枣仁汤善其后，七日而瘥。
【按】大论曰：厥深者，热亦深，厥微者，热亦微，厥应下之，而反发汗者，必口伤烂赤。今已口伤烂赤，考其原，咎在发汗，则更应下矣，此经文之可据以用承气者一也。阳明病，有日晡所发潮热之证，大论言之者屡，今病人昼日明了，暮则壮热，殊相合，此经文之可据以用承气者二也。更诊其脉，沉滑而有力，是为实，此脉象之可据以用承气者三也。西医曾以泻盐微下，则中夜略得安睡，此前治之可据以用承气者四也。有此四证，已可谓细心，若仍不能大胆投剂，尚得称为医家乎？曹颖甫曰：口伤烂赤，胃热也，大便燥结，肠热也，手足阳明俱热，不急泻之，病何能去？
小承气汤证
史左阙上痛，胃中气机不顺，前医投平胃散不应，当必有停滞之宿食，纳谷日减，殆以此也，拟小承气汤以和之。
生川军三钱后入中川朴二钱枳实四钱拙巢注：服此应手。
沈宝宝上巳日病延四十余日，大便不通，口燥渴，此即阳明主中土，无所复传之明证。前日经用泻叶下后，大便先硬后溏，稍稍安睡，此即病之转机。下后，腹中尚痛，余滞未清，脉仍滑数，宜调胃承气汤小和之。
【按】调胃承气汤、小承气汤并前大承气汤为三承气汤。三者药味各异，分量不同，煎法既殊，服法亦差，仲圣分之至详，用之至精。历来注家能辨之至稔，言之至明者，当推柯氏韵伯，学者当细心参究。惟窃有一二小义，当略略补充如下：仲圣常言胃中有燥矢，此胃中二字，当连读成一名词，即肠字之别称，并非言胃之中，故调胃承气之胃，微和胃气之胃，均可作胃中，或径作肠字解，比其一。柯氏谓调胃承气汤为太阳阳明并病之和剂，并谓此外之不解，由于里之不通，故太阳之头项强痛虽未除，而阳明之发热不恶寒已外现。不知阳明亦有头痛，惟痛在阙上，而不在太阳穴，阳明亦有发热，惟热属蒸蒸，而不属翕翕，故大论曰：太阳病，三日，发汗不解，蒸蒸发热者，属胃也，调胃承气汤主之。此不解二字并非表不解，乃太阳热去，阳明热继，亦不解之谓也。柯氏硬加头不痛句，反逆，此其二。柯氏请厚朴倍大黄是气药为君，大黄倍厚朴是气药为臣，谓之曰气，似尚见含糊，盖厚朴是肠药，能直达肠部，宽放肠壁。彼肠结甚者，燥矢与肠壁几密合无间，硝黄虽下，莫能施其技，故必用厚朴以宽其肠壁，而逐其矢气，如是燥矢方受攻而得去，此其三。
虽然，窃于大承气一法，犹有疑义焉。仲圣于本方中用厚朴至半斤之多，以吾师什一之法折之，当得八钱。但吾师用此，似未有至八钱者。吴氏又可为承气专家，而其大承气汤用大黄达五钱，至厚朴则一钱而已。吴氏鞠通较为阔步，本方用大黄六钱，用厚朴亦仅及其半量，至三钱而止。吴氏辨谓治伤寒本证，当重用厚朴，治温热本证，当减用之者。此乃点缀之语，非通人之论也。由是观之，使用严酷之眼光，细计药量之比重，世乃无有真大承气汤。阅者博雅，曾有惯用真大承气汤，而能识其底蕴者乎？
麻黄汤证— 麻杏甘石汤证— 承气汤证
—小承气汤证
桂枝汤证— 白虎汤证— —大承气汤证
葛根汤证— 葛根芩连汤证— —调胃承气汤证
此表之意犹曰：麻黄汤证化热入里，为麻杏甘石汤证。桂枝汤证化热入里，为白虎汤证。葛根汤证化热入里，为葛根芩连汤证。而葛根芩连汤证白虎汤证麻杏甘石汤证化热之后，则均为承气汤证。其肠结轻，可攻补兼施，所谓和之者，是为调胃承气汤证。其肠结较重者，亦用和法，即为小承气汤证。其肠结最重者，当用下法，又曰急下法，又曰攻法，即为大承气汤证。实则三承气汤方对于麻桂葛之汗法，及白虎汤之清法言，皆得曰下法也。
麻杏甘石汤证之传为承气汤证，在以上诸实验医案中，似尚未有述及。实则此种病例虽较白虎汤证传为承气汤证为少，却并不鲜见。盖经谓肺与大肠相表里，肠热可以移肺，肺热亦可及肠。所谓温邪上受，首先犯肺，逆传心包者，即系麻杏甘石汤重证，不能解于桑菊银翘，乃传为肠热，肠热不已，灼及神经，发作神昏谵语，遂指为逆传心包耳。依余临床所得，肺热传为肠热之后，其肺热每不因此而消。此时若但治其肺热，纵用麻杏石甘汤极重之量，必然无济，当急用承气汤法，去其肠热。如嫌承气伤肺，伐及无辜，则导法甚佳（法详中卷），余屡用之获效。肠热既去，续用麻杏甘石以治肺热，乃得有济。故大论曰下后，不可更行桂枝汤，汗出而喘，无大热者，可与麻黄杏仁甘草石膏汤。本条条文极似重出，当删，而事实上却有此例，奈何？甚有既下之后，而肺气自开，咳嗽自爽者，余亦屡屡逢之。有一俞姓小孩，于某月初三日，患咽痛，红肿，兼见白点，胸闷不舒。初四日，皮肤发出细点如麻。甲医断宜清血保咽，用生地川连黑梔淡芩之属。夜间，病孩喉肿谵语，齿介齿目赤。初五日，甲医用玄参生地山梔左金丸之属。易乙医，改投解肌透痧之剂，如豆豉薄荷葛根牛蒡之属。初六日，乙医主喉痧以透痧为要，重予透发之药。初七日，痧密布，夹白疒咅，热度更高，入夜梦呓。乙医虑其伤津，又与存阴清热之法，如连翘银花竹叶黛蛤散等。如是延至十一日晚，痧虽回而热不退，咳嗽气粗，鼻扇口噪，胸闷不舒，神识不清，加以腹痛拒按，耳下漫肿。丙医有识，曰：宜通腑气，径用生大黄三钱，元明粉一钱，并合透发之药，以达其余邪。其夜大便泛行，神烦即安，鼻扇耳肿悉渐退。
覆诊，依然用硝黄，直至粪色转黄，方予调理而安。由本案现之，凡肺热之转为肠热者，苟不设法去其肠中热结，但知透表生津，岂有济乎？然则麻杏甘石白虎葛根芩连三汤证皆能化热而为承气汤证，在病所方面言，三汤证之病所为较上，承气汤证之病所偏于肠，为较下，由此吾人得外感疾病传变之第三原则，曰由上传下是也。大论曰：阳明居中，主土也，万物所归，无所复传。其斯之谓乎？吾人研究上列九方，有一事当注意及者，即此九方中用甘草者竟达七方是也。
考据抵当汤证有发狂的表现，桃核承气汤证有如狂的状态，这都是血热影响脑神经的明显证据。所以用药总离不开大黄（Da Huang, Rhizoma et Radix Rhei），无非是脱胎于承气汤类方，这很值得深思。然而肠热容易侵犯脑部的人，与不容易侵犯脑部的人相比，其人的神经是否脆弱是一个主要因素，总之神经脆弱者容易被侵犯，如本案所载的情况就是如此，道理非常明显。另外小儿神经脆弱，所以惊厥类的病特别多。
曹颖甫说：阳明证的头痛，起初在印堂部位，严重时满头都痛，这不独是承气汤证有，就是白虎汤证也有。而且阳明腑实证燥气上冲，多导致脑中神经错乱，而出现谵语和头痛。或者反而在大便之后，无根的热毒上冒，如大便已通、头突然疼痛，就可以证明这一点。只有肠中有湿热蕴结蒸腾，其气容易犯脑，就像水气易于流动一样，正如锅下沸腾，蒸汽已经腾升到上面，不像燥屎凝结必须等待泻下后气才上冲。此证只要泻下浊水，就可以证明温热之邪蕴结在阳明。不然，眼睛视物不清，没有表证也没有里证，大便困难，身体微热的情况，为什么治法应当急下呢？
大承气汤证之三
我曾经诊治江阴街肉庄吴姓妇人，生病已经六七天，高热，头部出汗，脉象大，便秘，七天未排便，身体不发黄，胸部不痞硬，腹部不胀满，只是满头剧烈疼痛，不说话，眼睛睁着，瞳孔不能转动，人走到她面前，也不能辨认，病情相当危重。我说：眼睛视物不清，眼球转动不灵活，这是燥热上冲，属于《阳明篇》三急下证的第一证。如果不迅速治疗，病情就无法挽回了。于是随即写下大承气汤方给她。
大黄四钱，枳实三钱，厚朴一钱，芒硝三钱。并嘱咐家属赶快煎服，竟然一剂药就痊愈了。这是因为阳明燥气上冲至头顶，所以头部出汗，满头剧痛，神识不清，眼睛不能辨认人，形势危急在顷刻之间。现在一剂药下去，也如同釜底抽薪，泄去胃热，胃热一平，那么上冲的燥气因为下面没有后继之力，随之一起下行，所以头目清明，病立刻好了。并不是像有宿食积滞，腹胀而痛，高热谵语那样，必须经过几剂药才能见效，这就是缓急的区别所在。因此无形的气与有形的积滞，应该加以辨别，才不会在临诊时茫然失措。
【按】我曾经见过一个男病人，神志恍惚，四肢痉挛厥冷，左手按着额头，右手按其阴部，两脚相对弯曲并耸起。旁边的人虽然用大力气，不能使他伸直，眼睛睁着且红，靠近光则强闭，脉象凌乱隐约，大便多天不行，这几天来头痛，病起仅七八天，服药五六天，就到了这种地步，据说以前曾嫖娼患疮，外治而愈。我说：这是大承气汤证失治的结果。但是口噤药不能下，替身者用简便法，将甘油栓纳入肛门中，凡三次，毫无效验。可惜没有亲人在旁做主，不能用胆导法（一种通便方法）。第二天汗出，夜间死亡，真是可怜啊。又有一个男病人感病几天，腹中轻微疼痛，医生用四逆散作汤剂给他，痛稍微好转，但眼睛视物不清更加明显。跟他说话，半对半错，当天晚上就死了。
通过上述实验验证，眼睛视物不清，眼球转动不灵活，确实是极其危险紧急的症状，即使伤寒不过六七天，没有表证里证，身体只是微热，大便只是难而不结，只要是实证，就应当急下，适宜用大承气汤。
仲景在论著中写得非常明了。如果能治疗方法得当，获得疗效也很迅速，如本案所示就是这样。
眼睛视物不清，眼球转动不灵活，就是脑病的外部征象。外见眼疾，内实为脑病，比起上案所说的仅满头剧痛者，其病更严重一些，其情势更紧急一等，其方药分量应当更重若干，而治疗没有第二法门，除了大承气汤别无选择。虽然如此，《伤寒论》又说：伤寒，如果经过吐法或下法后，病不解，不大便五到六天，甚至十几天，傍晚时分出现潮热，不恶寒，独自说话，好像看见鬼怪一样，如果严重的，发作时不认识人，抓摸衣被床沿，惊恐不安，微微气喘，直视，脉弦则生，脉涩者死，轻微的，只是发热谵语的，大承气汤主治。可见脑神经病到了不认识人，到了独自说话像见鬼怪，到了抓摸衣被床沿，到了脉涩，轻微的尚可用大承气汤主治，严重的即使投以此汤，也没有效了。试着推求其无效的原因在哪里？答：大承气汤只能治疗肠热这一病源，不能治疗神经这一病所，病源虽去，而病所燎原之势已成，所有神经都受到烧灼，所以外见种种恶状，最终导致无法救治。那么在当时，用什么药来救它呢？答：有的，大概只有羚羊角吧。《本草纲目》说：本品平肝舒筋，定风安魂，散血下风，辟恶解毒，治疗子痫痉疾等等。所谓恶，所谓毒，是因为热而产生的；所谓肝，所谓筋，即指神经。热毒熏灼神经，则出现痉挛抽搐，这就是所谓的肝风动阳。羚羊角能凉和神经，使之舒静，所以用法得当剂量合适，可以治疗大承气汤所不能治疗的证候。其他药物如石决明、钩藤、全蝎尾、蜈蚣，都可以作为辅助。
曹颖甫说：恽铁樵治疗王鹿萍儿子的脑膜炎，用羚羊角、犀角奏效，这是王鹿萍儿子亲自告诉我的。结合佐景所说的话，更加可信。足以看出治疗危急的证候，原本有经方所不具备的，而借力于后世医家的发明，所以治病贵在具有通识。
大承气汤证之四
陈姓少年住在无锡路矮屋，十六岁，幼年丧父，只依靠母亲，终年勤劳，还难以吃饱。恰逢新年，贩卖花炮，希望博取微薄利润。饮食不规律，饥餐冷饭，又受风寒，于是生病腹痛拒按，时常腹泻，颜色纯黑，身体不热，脉滑大而口渴。家境清贫，无力请医生。经过十多天，才来求诊。观察他的症状，知道是积滞下利，于是开大承气汤方，怜悯他贫穷，去掉厚朴。计大黄四钱，枳实四钱，芒硝二钱。写完，对他的母亲说：如果服药后暴下比之前更厉害，旧病可以痊愈。他母亲奇怪地说：不止住他的腹泻，反而加速他的腹泻，为什么呢？我说：服药后自然知道。果然一剂后，大下三次，都是黑粪，干湿混杂，利止而愈。这就是《金匮要略》所说的宿食下利，应当有所去除，泻下乃愈，适宜用大承气汤的例子。
【按】《伤寒论》说：少阴病，自利清水，颜色纯青，心下必定痛，口干，咽燥的，急下之。宜用大承气汤。可以互相印证。《温疫论》说：热结傍流者，因为胃家实，内热壅闭，先是大便闭结，随后得到下利，纯臭水，完全没有粪便，一天三四次，或十几次，宜用大承气汤，得到结粪而利止。服用汤药没有得到结粪，仍然下利，并排臭水，以及所进的汤药，因为大肠邪胜，失去传送的功能，知道邪气还在，病必定不减，宜再次泻下。延陵吴又可先贤能说出这些，确实不愧为仲圣的入室弟子。
客人说：仲景论述伤寒，又可论述温疫，你怎么可以混为一谈？回答说：唉！这是什么话？仲景说：观其脉证，知犯何逆，随证治之。我们中医的长处，就在于能识别这个“证”字，如果察看病者所犯的是大承气汤证，就投以大承气汤，所犯的是四逆汤证，就投以四逆汤，服药后，效果若响斯应，那么之前的病叫什么名字，起初不必拘泥。
大承气汤证之五
《伤寒论》说：厥证应当用下法，反而发汗的，必定口舌生疮糜烂发红。按寒郁于外，热伏于里，那么其证应当等待阳热渐回而下之，使热邪从下部宣泄，病就好了。如果发其汗，则胃中津液枯竭，胆火生燥，于是转变为阳明热证，成为口伤烂赤的原因。这与反常出汗而导致咽痛、喉痹的情况，是同样的例子。由其发汗太过，而阳气上盛所致。此证我过去在四明医院亲眼见过。起初的病，我没见到，等我往诊时，已满口烂赤。检查他的前方，是最轻分量的桂枝汤，案中记载恶寒。病在太阳而用桂枝，虽然不能确定确切恰当与否，但也相去不远。后来病转阳明，连服白虎汤五剂，前医认为不治。老友周肖彭嘱我同诊。问其状况，白天清醒，傍晚高热，彻夜不得眠。营气夜间行于阳，日暮发热属血分，昼明夜昏与妇人热入血室相同。热入血室用桃核承气汤，那么此证实以厥阴而兼阳明燥化。病者说经西医用泻盐下大便一次，则半夜略能安睡。诊其脉，沉滑有力。我因此用大承气汤，每日一剂，五天热退。肖彭用酸枣仁汤善后，七天痊愈。
【按】《伤寒论》说：厥深者，热亦深，厥微者，热亦微，厥应当用下法，反而发汗的，必定口伤烂赤。现在已经口伤烂赤，考察其原因，过错在发汗，则更应该下矣，这是经文可依据使用承气汤的一点。阳明病，有傍晚时分出现潮热的证候，《伤寒论》多次提及，今病人白天清醒，傍晚高热，特别符合，这是经文可依据使用承气汤的第二点。再诊其脉，沉滑而有力，是为实证，这是脉象可依据使用承气汤的第三点。西医曾用泻盐轻微泻下，则半夜略得安睡，这是前医治法可依据使用承气汤的第四点。有此四证，可以说细心了，如果仍不能大胆投剂，还算得上是医家吗？曹颖甫说：口伤烂赤，是胃热，大便燥结，是肠热，手足阳明俱热，不急泻之，病怎么能去？
小承气汤证
史左印堂部位痛，胃中气机不顺，前医投平胃散不应，应当必有停滞的宿食，进食日渐减少，大概就是这个原因，拟小承气汤来调和它。
生川军三钱（后下），中川朴二钱，枳实四钱。拙巢注：服此应手。
沈宝宝在上巳日生病延续四十多天，大便不通，口燥渴，这就是阳明主中土，无所复传的明显证据。前天经用泻叶下后，大便先硬后溏，稍稍安睡，这就是病的转机。下后，腹中尚痛，余滞未清，脉仍滑数，宜调胃承气汤小和之。
【按】调胃承气汤、小承气汤并前大承气汤为三承气汤。三者药味各异，分量不同，煎法既殊，服法亦差，仲景分得非常详细，用得十分精妙。历来注家能辨之非常熟悉，言之非常明白的，当推柯韵伯，学者应当细心参究。但我窃有一二小义，应当略微补充如下：仲景常言胃中有燥矢，此“胃中”二字，应当连读成一名词，即肠字的别称，并非言胃之中，所以调胃承气之“胃”，微和胃气之“胃”，均可作胃中，或径作肠字解，这是一点。柯氏谓调胃承气汤为太阳阳明并病之和剂，并谓此外之不解，由于里之不通，故太阳的头项强痛虽未除，而阳明的发热不恶寒已外现。不知阳明亦有头痛，惟痛在印堂，而不在太阳穴，阳明亦有发热，惟热属蒸蒸，而不属翕翕，所以《伤寒论》说：太阳病，三日，发汗不解，蒸蒸发热者，属胃也，调胃承气汤主之。此“不解”二字并非表不解，乃太阳热去，阳明热继，亦是不解的意思。柯氏硬加头不痛句，反而违背，这是第二点。柯氏请厚朴倍大黄是气药为君，大黄倍厚朴是气药为臣，谓之曰气，似乎还见含糊，盖厚朴是肠药，能直达肠部，宽放肠壁。那些肠结甚重的，燥矢与肠壁几乎密合无间，硝黄虽下，莫能施其技，故必用厚朴以宽其肠壁，而逐其矢气，如是燥矢方受攻而得去，这是第三点。
虽然，我对于大承气一法，仍有疑义。仲景在本方中用厚朴至半斤之多，以吾师什一之法折算，当得八钱。但吾师用此，似乎未有至八钱者。吴氏又可为承气专家，而其大承气汤用大黄达五钱，至于厚朴则一钱而已。吴鞠通较为阔步，本方用大黄六钱，用厚朴亦仅及其半量，至三钱而止。吴氏辨谓治伤寒本证，当重用厚朴，治温热本证，当减用之者。此乃点缀之语，非通人之论也。由此观之，使用严酷的眼光，细计药量之比重，世上就没有真正的大承气汤了。阅者博雅，曾有惯用真正大承气汤，而能识其底蕴者乎？
麻黄汤证— 麻杏甘石汤证— 承气汤证
—小承气汤证
桂枝汤证— 白虎汤证— —大承气汤证
葛根汤证— 葛根芩连汤证— —调胃承气汤证
此表之意是说：麻黄汤证化热入里，变为麻杏甘石汤证。桂枝汤证化热入里，变为白虎汤证。葛根汤证化热入里，变为葛根芩连汤证。而葛根芩连汤证、白虎汤证、麻杏甘石汤证化热之后，则均为承气汤证。其肠结轻，可攻补兼施，所谓和之者，是为调胃承气汤证。其肠结较重者，亦用和法，即为小承气汤证。其肠结最重者，当用下法，又叫急下法，又叫攻法，即为大承气汤证。实则三承气汤方对于麻桂葛之汗法，及白虎汤之清法而言，皆得曰下法也。
麻杏甘石汤证传为承气汤证，在以上诸实验医案中，似乎尚未有述及。实则此种病例虽较白虎汤证传为承气汤证为少，却并不鲜见。盖经谓肺与大肠相表里，肠热可以移肺，肺热亦可及肠。所谓温邪上受，首先犯肺，逆传心包者，即系麻杏甘石汤重证，不能解于桑菊银翘，乃传为肠热，肠热不已，灼及神经，发作神昏谵语，遂指为逆传心包耳。依余临床所得，肺热传为肠热之后，其肺热每不因此而消。此时若但治其肺热，纵用麻杏石甘汤极重之量，必然无济，当急用承气汤法，去其肠热。如嫌承气伤肺，伐及无辜，则导法甚佳（法详中卷），余屡用之获效。肠热既去，续用麻杏甘石以治肺热，乃得有济。所以《伤寒论》说下后，不可更行桂枝汤，汗出而喘，无大热者，可与麻黄杏仁甘草石膏汤。本条条文极似重出，当删，而事实上却有此例，奈何？甚有既下之后，而肺气自开，咳嗽自爽的，我也屡屡遇到。有一个俞姓小孩，于某月初三日，患咽痛，红肿，兼见白点，胸闷不舒。初四日，皮肤发出细点如麻。甲医断宜清血保咽，用地黄、黄连、黑栀子、淡黄芩之类。夜间，病孩喉肿谵语，齿介齿目赤。初五日，甲医用玄参、生地、山栀、左金丸之类。换乙医，改投解肌透痧之剂，如豆豉、薄荷、葛根、牛蒡之类。初六日，乙医主喉痧以透痧为要，重予透发之药。初七日，痧密布，夹白疒咅，热度更高，入夜梦呓。乙医虑其伤津，又与存阴清热之法，如连翘、银花、竹叶、黛蛤散等。如是延至十一日晚，痧虽回而热不退，咳嗽气粗，鼻扇口噪，胸闷不舒，神识不清，加以腹痛拒按，耳下漫肿。丙医有识，说：宜通腑气，径用生大黄三钱，元明粉一钱，并合透发之药，以达其余邪。其夜大便泛行，神烦即安，鼻扇耳肿悉渐退。
复诊，依然用硝黄，直至粪色转黄，方予调理而安。由本案现之，凡肺热之转为肠热者，苟不设法去其肠中热结，但知透表生津，岂有济乎？然则麻杏甘石、白虎、葛根芩连三汤证皆能化热而为承气汤证，在病所方面言，三汤证之病所为较上，承气汤证之病所偏于肠，为较下，由此吾人得外感疾病传变之第三原则，曰由上传下是也。《伤寒论》说：阳明居中，主土也，万物所归，无所复传。说的就是这个吧？吾人研究上列九方，有一事当注意及者，即此九方中用甘草者竟达七方是也。
Examining the Zhidang Tang (Resolute Decoction) syndrome, there are manifestations of mania; in the Taoheshengqi Tang (Peach Kernel and Magnolia Bark Decoction) syndrome, there is a state resembling mania. These are clear evidence that blood heat affects the brain nerves. Therefore, the medication generally does not depart from Dahuang (Rhubarb Rhizome), but rather derives from the Chengqi (Assist to Enter the Qi) decoctions, which is worthy of deep reflection. However, regarding intestinal heat easily invading the brain versus not easily invading it, whether a person's nerves are fragile or not is a major factor; indeed, those with fragile nerves are more easily affected, as shown in this case, which makes the principle very clear. Furthermore, children have fragile nerves, so convulsive diseases are particularly common.
Cao Yingfu said: In Yangming syndrome headache, it initially occurs at the Yintang area (between the eyebrows), and in severe cases, the entire head hurts. This is not only seen in Chengqi Tang syndromes but also in Baihu Tang (White Tiger Decoction) syndromes. Moreover, in Yangming Fu-organ excess syndrome, dryness qi rushing upward often causes confusion of the brain nerves, leading to delirium and headache. Or, conversely, after defecation, rootless heat toxins rush upward; for example, if the bowels have moved but the head suddenly becomes painful, this can be proven. Only when there is damp-heat accumulating and steaming in the intestines does its qi easily invade the brain, similar to how water vapor flows easily. Just as boiling water below sends steam rising above, unlike dry fecal matter which must wait for purgation before its qi rushes upward. In this syndrome, simply purging turbid water can prove that warm-heat pathogens are accumulating in the Yangming. Otherwise, why should the treatment method for symptoms such as unclear vision ("mu zhong le le bu liao"), absence of exterior or interior signs, difficulty in defecation, and slight fever be urgent purgation?
**Case Three of Dachengqi Tang Syndrome**
I once treated a woman surnamed Wu from a butcher shop on Jiangyin Street. She had been ill for six or seven days, presenting with high fever, sweating only on the head, a large pulse, constipation, and no bowel movement for seven days. Her body was not yellow, her chest was not stiff, and her abdomen was not distended. She suffered only from severe headache all over her head, did not speak, kept her eyes open, her pupils could not blink, and she could not recognize people approaching her. The condition was quite critical. I said: "Unclear vision and inflexible eyeballs indicate dry-heat rushing upward. This is the first of the three urgent purgation syndromes in the Yangming Chapter. If not treated quickly, the disease will become incurable." I then prescribed Dachengqi Tang (Major Order the Qi Decoction).
Dahuang (Rhubarb Rhizome) 4 qian, Zhishi (Immature Bitter Orange) 3 qian, Chuanpu (Aucklandiae Radix) 1 qian, Mangxiao (Mirabilite) 3 qian. I instructed the family to decoct and administer it quickly. Remarkably, one dose resulted in a cure. Because Yangming dryness qi rushed upward to the vertex, causing head sweating, severe headache, clouded consciousness, and inability to recognize people, the situation was critical in an instant. Now, with one dose, it is like removing firewood from under the cauldron; stomach heat is drained. Once stomach heat is pacified, the rushing dryness qi, having no further support from below, descends together with it. Thus, the head and eyes become clear, and the illness vanishes instantly. This differs from cases with retained food stagnation, abdominal distension and pain, high fever, and delirium, which require several doses to take effect. This distinguishes the slow from the urgent. Therefore, one must distinguish between formless qi and formed accumulation to avoid confusion during clinical practice.
[Note] I once saw a male patient with fluctuating consciousness, spasms and cold extremities in the four limbs, holding his forehead with his left hand and his genitals with his right, his legs bent inward and raised. Despite great effort by bystanders, he could not be straightened. His eyes were open and red, and he closed them tightly near light. His pulse was chaotic and faint. He had not defecated for many days and had suffered headaches recently. The illness began only seven or eight days ago, and after taking medicine for five or six days, he reached this state. It was said he previously contracted a venereal disease from visiting prostitutes, which was cured externally. I said: "This is a Dachengqi Tang syndrome that was neglected." However, due to trismus (lockjaw), medicine could not be swallowed. An assistant used a simple method, inserting glycerin suppositories into the anus three times, with no effect. Unfortunately, no relative was present to authorize the use of a gallbladder-based cathartic method (Dan Dao Fa). The next day, he sweated and died at night; it was truly pitiable. Another male patient fell ill for a few days with mild abdominal pain. A doctor gave him Sini San (Frigid Extremities Powder) as a decoction. The pain improved slightly, but his unclear vision worsened significantly. When spoken to, he answered half correctly and half incorrectly, and died that night.
Based on the above experimental verification, "unclear vision and inflexible eyeballs" are indeed extremely critical and urgent conditions. Even if Shanghan (Cold Damage) has lasted only six or seven days, with no exterior or interior signs, only slight fever, and difficult but unformed stool, if it is a excess syndrome, urgent purgation is indicated, and Dachengqi Tang is appropriate.
Zhong Jing wrote about this clearly in his treatise. If treated with proper methods, efficacy is also swift, as demonstrated in this case.
"Unclear vision and inflexible eyeballs" are external signs of brain disease. External eye pathology indicates internal brain pathology. Compared to the previous case mentioning only severe headache, this condition is more severe and more urgent, requiring heavier dosages. There is no second method of treatment other than Dachengqi Tang. Nevertheless, the Great Treatise also states: "In Shanghan, if vomiting or purgation fails to resolve the condition, and there is no bowel movement for five to six days, up to ten or more days, tidal fever occurs at dusk, without aversion to cold, with solitary muttering as if seeing ghosts. If severe, the patient may not recognize people, grasp at clothes and bedrails, feel terrified and uneasy, breathe slightly short, stare fixedly. If the pulse is wiry, life is possible; if choppy, death ensues. If mild, merely fever and delirium occur, Dachengqi Tang governs." This shows that even when brain nerve disease progresses to not recognizing people, muttering alone as if seeing ghosts, grasping at objects, or a choppy pulse, if mild, Dachengqi Tang can still be used. If severe, even administering this decoction will be ineffective. Let us deduce the reason for ineffectiveness: Dachengqi Tang can only treat the source of intestinal heat, not the location of nerve damage. Although the source is removed, the blaze at the site has already spread, scorching all nerves, leading to various adverse external manifestations and ultimately fatal outcomes. So, what medicine can save the patient at this time? Answer: There is one, namely Lingyangjiao (Antelope Horn). *Bencao Gangmu* states: "This product soothes the liver, relaxes sinews, stabilizes wind, calms the soul, disperses blood, expels wind, wards off evil, detoxifies, and treats infantile convulsions and spasms." What is called "evil" and "toxin" arises from heat. What is called "liver" and "sinew" refers to nerves. When heat-toxicity scorches nerves, spasms and convulsions appear, which is what is meant by "Liver Wind stirring Yang." Lingyangjiao can cool and harmonize nerves, making them calm. Therefore, if used properly and in correct dosage, it can treat conditions that Dachengqi Tang cannot. Other herbs such as Shijueming (Concha Haliotidis), Gouxi (Uncariae Ramulus cum Uncis), Quanxie (Buthus), and Wugong (Scolopendra) can serve as assistants.
Cao Yingfu said: Yun Tieqiao treated Wang Luping's son with meningitis using Lingyangjiao (Antelope Horn) and Xijiao (Rhino Horn) with success. Wang Luping's son told me this personally. Corroborating Zuo Jing's statements, this is highly credible. It shows that treating critical conditions often requires remedies not covered by classical formulas, borrowing from the innovations of later experts. Thus, medical treatment values comprehensive understanding.
**Case Four of Dachengqi Tang Syndrome**
A young man surnamed Chen lived in a small house on Wuxi Road. At sixteen, he lost his father early and relied solely on his mother. Working hard all year, he barely managed to eat his fill. During the New Year, he sold fireworks hoping for a small profit. Due to irregular diet, eating cold rice when hungry, and exposure to wind-cold, he developed abdominal pain that refused pressure, frequent diarrhea with pure black stool, no fever, and a slippery, large pulse with thirst. His family was poor and could not afford a doctor. After more than ten days, he came for consultation. Observing his symptoms, I knew it was diarrhea due to stagnation. I prescribed Dachengqi Tang, but out of pity for his poverty, omitted Houpo (Magnolia Bark). The prescription consisted of Dahuang 4 qian, Zhishi 4 qian, and Mangxiao 2 qian. After writing it, I told his mother: "If after taking the medicine you experience violent diarrhea worse than before, the old disease will be cured." His mother asked strangely: "Instead of stopping the diarrhea, you accelerate it? Why?" I replied: "You will know after taking it." Indeed, after one dose, he had three large bowel movements consisting of black stool, mixed wet and dry. The diarrhea stopped, and he was cured. This is the example cited in *Jingui Yaolue*: "Diarrhea due to retained food should be treated by removing the retention; purgation leads to cure, suitable for Dachengqi Tang."
[Note] The Great Treatise states: "Shaoyin syndrome with spontaneous diarrhea of clear water, pure green color,必定 pain in the epigastrium, dry mouth, and dry throat, requires urgent purgation. Dachengqi Tang is suitable." This can corroborate each other. *Wenyi Lun* states: "Heat binding with lateral flow occurs because of Stomach excess and internal heat blockage. Initially constipation follows by diarrhea of pure foul-smelling water, completely devoid of feces, occurring three to four times or more than ten times a day. Dachengqi Tang is suitable. Cure occurs when solid feces are expelled and diarrhea stops. If after taking the decoction, solid feces are not expelled, and diarrhea of foul water and ingested medicine continues, it is because the large intestine's pathogenic excess has caused loss of its transportation function, indicating the pathogen remains. The disease will not decrease; another purgation is needed." The late scholar Wu Youke of Yanling spoke thus, truly deserving to be called a direct disciple of Zhong Jing.
A guest asked: "Zhong Jing discusses Shanghan, while Youke discusses Wenyi. How can you mix them?" I replied: "Alas! What kind of words are these? Zhong Jing said: 'Observe the pulse and symptoms, understand what deviation has occurred, and treat according to the syndrome.' The strength of our TCM lies precisely in recognizing this 'syndrome' character. If we observe that the patient presents a Dachengqi Tang syndrome, we administer Dachengqi Tang; if they present a Sini Tang syndrome, we administer Sini Tang. If the effect responds like an echo after administration, then the name of the preceding disease need not be rigidly adhered to."
**Case Five of Dachengqi Tang Syndrome**
The *Shanghan Lun* states: "Jue (cold extremities) syndromes should be treated with purgation; if sweating is used instead, oral ulcers and redness will certainly occur." Cold constrained externally and heat trapped internally means the syndrome should wait for yang heat to gradually return before purging, allowing heat pathogens to vent from the lower part, curing the disease. If sweating is induced, stomach fluids are depleted, Gallbladder fire generates dryness, transforming into a Yangming heat syndrome, resulting in oral ulcers and redness. This is analogous to abnormal sweating leading to sore throat and bi-syndrome in the throat, caused by excessive sweating leading to excessive yang qi ascending. I personally witnessed this case at Siming Hospital. I did not see the initial illness, but when I consulted, the mouth was fully ulcerated and red. Checking the previous prescription, it was the lightest dosage of Guizhi Tang, with the record noting aversion to cold. Using Guizhi Tang for a Taiyang disease might not be entirely accurate, but it is close enough. Later, the disease transformed into Yangming. After taking Baihu Tang for five doses, the previous doctor deemed it incurable. My old friend Zhou Xiaopeng asked me to consult together. Asking about the condition: clear during the day, high fever at dusk, unable to sleep all night. Ying qi travels through yang at night; fever at dusk belongs to the blood level. Clarity by day and confusion by night is similar to women's heat entering the blood chamber. Heat entering the blood chamber uses Taoheshengqi Tang; thus, this syndrome involves Jueyin combined with Yangming dryness transformation. The patient stated that after Western doctors administered Epsom salts for one bowel movement, he could sleep slightly better in the middle of the night. His pulse was deep, slippery, and forceful. I therefore used Dachengqi Tang, one dose daily. Fever subsided after five days. Xiaopeng followed up with Suanzaoren Tang, and recovery occurred in seven days.
[Note] The Great Treatise states: "The deeper the jue, the deeper the heat; the milder the jue, the milder the heat. Jue should be treated with purgation; if sweating is used instead, oral ulcers and redness will occur." Since oral ulcers and redness are now present, investigating the cause reveals fault in sweating, so purgation should be employed even more. This is the first basis from the text for using Chengqi. Yangming syndrome features tidal fever at dusk, frequently mentioned in the Great Treatise. The current patient is clear by day and has high fever at dusk, which matches perfectly. This is the second basis. Further examination of the pulse reveals it is deep, slippery, and forceful, indicating excess. This is the third basis from the pulse image. Western doctors previously used Epsom salts for mild purgation, allowing slight rest at midnight. This is the fourth basis from previous treatment. With these four indications, one can claim carefulness; if one still cannot boldly administer the formula, can one be called a physician? Cao Yingfu said: "Oral ulcers and redness indicate stomach heat; dry fecal impaction indicates intestinal heat. Both Hand-Yangming and Foot-Yangming are hot. If not urgently purged, how can the disease be eliminated?"
**Xiaochengqi Tang Syndrome**
Patient Shi experienced pain at the Yintang area. Qi mechanism in the stomach was not smooth. Previous treatment with Pingwei San was ineffective. There must be stagnant retained food, leading to decreased appetite. I proposed Xiaochengqi Tang (Minor Order the Qi Decoction) to harmonize.
Sheng Chuanjun (Raw Rhubarb) 3 qian (added later), Zhong Chuanpu (Aucklandia) 2 qian, Zhishi 4 qian. Zhu Chao's Note: Effect is immediate upon ingestion.
**Tiaowei Chengqi Tang Syndrome**
Patient Shen Baobao became ill on the Si Day of the Spring month, lasting over forty days. No bowel movement, dry mouth and thirst. This is clear evidence that Yangming dominates the central earth and transmission ceases. Previously, using Senna leaves led to hard stool followed by loose stool, and slightly better sleep. This is a turning point in the disease. After purgation, abdominal pain persists, residual stagnation is not cleared, and the pulse remains slippery and rapid. Tiaowei Chengqi Tang (Regulate the Stomach Assist to Enter Qi Decoction) should be used gently to harmonize.
Sheng Chuanjun (Raw Rhubarb) 2 qian (added later), Sheng Gancao (Raw Licorice) 3 qian, Mangxiao (Mirabilite) 1 qian (dissolved).
[Note] Tiaowei Chengqi Tang, Xiaochengqi Tang, and the aforementioned Dachengqi Tang constitute the three Chengqi Decoctions. Their ingredients differ, dosages vary, decoction methods are distinct, and administration methods differ. Zhong Jing divided them in great detail and applied them with precision. Among commentators throughout history, Ke Yunbo distinguished them most thoroughly and explained them most clearly. Students should study them carefully. However, I wish to supplement a few minor points: Zhong Jing often mentions "dry feces in the stomach." The term "Wei Zhong" (Stomach Middle) here should be read as a single noun, meaning "Intestine," not literally inside the stomach. Therefore, the "Wei" in Tiaowei Chengqi Tang and the "Wei" in harmonizing stomach qi can both be interpreted as "stomach middle" or directly as "intestine." This is point one. Ke claimed Tiaowei Chengqi Tang is a harmonizing formula for concurrent Taiyang and Yangming disease, stating that exterior unresolved status is due to interior obstruction. Thus, although Taiyang neck stiffness remains, Yangming fever without aversion to cold appears externally. Ignoring that Yangming also has headaches, specifically at Yintang, not Taiyang acupoints, and Yangming also has fever, specifically steaming heat, not fluttering heat. Hence, the Great Treatise says: "Taiyang disease, three days, sweating fails to resolve, steaming heat occurs, belonging to the Stomach, Tiaowei Chengqi Tang governs." Here, "unresolved" does not mean exterior unresolved, but rather Taiyang heat gone, Yangming heat succeeding, also termed "unresolved." Ke forcibly added "no headache," which contradicts the text. This is point two. Ke suggested Houpo doubled with Dahuang makes Qi herb the sovereign, and Dahuang doubled with Houpo makes Qi herb the minister. Calling them "Qi" seems vague. Houpo is an intestinal herb that reaches the intestine directly, widening the intestinal wall. In severe intestinal binding, dry feces adhere tightly to the intestinal wall. Even if Xiaoming and Dahuang enter, they cannot exert their effect. Thus, Houpo must be used to widen the intestinal wall and drive out flatus, so that dry feces can be attacked and expelled. This is point three.
Nevertheless, I still have doubts regarding Dachengqi Tang. Zhong Jing used Houpo up to half a jin in this formula. Converting to my teacher's one-tenth method, this would be eight qian. But my teacher rarely used it up to eight qian. Wu Yi can be considered an expert on Chengqi formulas, yet his Dachengqi Tang used Dahuang up to five qian, while Houpo was only one qian. Wu Jutong was bolder, using Dahuang six qian and Houpo only half that amount, up to three qian. Wu argued that for treating primary Shanghan, heavy Houpo should be used; for treating primary Warm Disease, reduced Houpo should be used. This is mere embellishment, not the view of a knowledgeable person. Viewing this strictly and calculating dosage ratios, there is no true Dachengqi Tang in the world. Erudite readers, have you ever commonly used the true Dachengqi Tang and understood its essence?
Having concluded the discussion of nine syndromes from Guizhi Tang to Tiaowei Chengqi Tang, we can compile a table as follows:
Mahuang Tang Syndrome — Maxing Shigan Tang Syndrome — Chengqi Tang Syndrome
— Xiaochengqi Tang Syndrome
Guizhi Tang Syndrome — Baihu Tang Syndrome — — Dachengqi Tang Syndrome
Gegen Tang Syndrome — Gegen Qinlian Tang Syndrome — — Tiaowei Chengqi Tang Syndrome
The meaning of this table is: Mahuang Tang syndrome transforms heat entering the interior to become Maxing Shigan Tang syndrome. Guizhi Tang syndrome transforms heat entering the interior to become Baihu Tang syndrome. Gegen Tang syndrome transforms heat entering the interior to become Gegen Qinlian Tang syndrome. After Gegen Qinlian Tang, Baihu Tang, and Maxing Shigan Tang syndromes transform heat, they all become Chengqi Tang syndromes. For mild intestinal binding, attack and tonification can be combined; this "harmonizing" approach is Tiaowei Chengqi Tang syndrome. For moderate intestinal binding, the harmonizing method is also used, which is Xiaochengqi Tang syndrome. For severe intestinal binding, the purgative method, also called urgent purgation or attacking method, is Dachengqi Tang syndrome. In reality, the three Chengqi formulas, compared to the sweating methods of Mahuang, Guizhi, and Gegen, and the clearing method of Baihu Tang, can all be called purgative methods.
The transmission of Maxing Shigan Tang syndrome to Chengqi Tang syndrome seems not yet described in the above experimental medical cases. In fact, although such cases are fewer than Baihu Tang transforming into Chengqi Tang, they are not rare. The classics state that the Lung and Large Intestine are exterior-interior related. Intestinal heat can transfer to the Lung, and Lung heat can affect the Intestine. What is called "Warm pathogens received from above, first attacking the Lung, reversely transmitting to the Pericardium" refers to severe Maxing Shigan Tang syndrome. Unable to resolve with Sangju Yin or Yinqiao San, it transmits to intestinal heat. Unchecked intestinal heat scorches the nerves, causing coma and delirium, which is then labeled as reverse transmission to the Pericardium. Based on my clinical experience, after Lung heat transfers to intestinal heat, the Lung heat often does not dissipate. At this time, if only treating Lung heat, even with extremely heavy doses of Maxing Shigan Tang, it will inevitably be useless. One must urgently use Chengqi methods to remove intestinal heat. If one worries that Chengqi harms the Lung, punishing the innocent, then the Guiding Method (Dao Fa, detailed in the middle volume) is excellent. I have used it repeatedly with success. Once intestinal heat is removed, continuing with Maxing Shigan Tang to treat Lung heat yields results. Hence, the Great Treatise states: "After purgation, do not use Guizhi Tang again. If sweating and wheezing occur without significant heat, Maxing Gan Shi Tang can be given." This clause seems redundant and should be deleted, yet clinically this example exists. How strange? Very often, after purgation, Lung qi opens naturally, and coughing clears. I have encountered this repeatedly. A child surnamed Yu suffered from sore throat, redness and swelling, accompanied by white spots and chest discomfort on the 3rd day of a certain month. On the 4th day, fine spots like hemp appeared on the skin. Doctor Jia diagnosed the need to clear blood and protect the throat, using Shengdi, Huanglian, Heizhizi, Danqin, etc. That night, the child's throat swelled, he muttered deliriously, ground his teeth, and his eyes were red. On the 5th day, Doctor Jia used Xuanshen, Shengdi, Shanzhizi, Zuojin Wan, etc. Doctor Yi changed the prescription to muscle-releasing and rash-expelling agents like Douchi, Bohe, Gegen, Niubangzi, etc. On the 6th day, Doctor Yi emphasized expelling rash for throat scarlet fever, heavily prescribing rash-expelling medicines. On the 7th day, the rash was dense, mixed with white patches, temperature higher, muttering in dreams at night. Worried about fluid injury, Doctor Yi used fluid-nourishing and heat-clearing methods like Lianqiao, Yinhua, Zhuye, Daihe San, etc. By the evening of the 11th day, although the rash receded, fever persisted. Coughing was rough, nasal flaring, mouth breathing, chest discomfort, clouded consciousness, plus abdominal pain refusing pressure, and diffuse swelling below the ears. Doctor Bing, who had insight, said: "One should unblock the fu organs." Directly using Sheng Dahuang 3 qian and Yuanmingfen 1 qian, combined with rash-expelling medicines to eliminate remaining pathogens. That night, bowel movements occurred frequently, mental agitation settled, nasal flaring and ear swelling gradually receded.
On follow-up, Xiaoming and Dahuang were continued until stool color turned yellow, then conditioning therapy was given for peace. From this case, it is evident that for Lung heat transforming into intestinal heat, if one does not attempt to remove intestinal heat binding, but only knows how to release the exterior and generate fluids, what benefit is there? Thus, Maxing Shigan, Baihu, and Gegen Qinlian three tang syndromes can all transform heat into Chengqi Tang syndromes. Regarding the disease location, the three tang syndromes' locations are relatively upper, while Chengqi Tang syndrome's location leans toward the intestine, which is relatively lower. From this, we derive the third principle of exogenous disease transmission: from upper to lower. The Great Treatise states: "Yangming resides in the center, governing Earth. All things return to it, and transmission ceases." Is this what is meant? In studying the nine formulas listed above, one thing deserves attention: among these nine formulas, seven contain Gancao (Licorice Root).
The upper three formulas (Mahuang, Guizhi, Gegen) do not leave out Gancao. The middle three formulas do not detach from Gancao. The lower Tiaowei Chengqi Tang also uses Gancao.