治少阳受邪。往来寒热。脉弦。胁痛而呕。
柴胡（三钱） 黄芩 人参 甘草（炙。各一钱） 半夏（二钱） 生姜（五片）
大枣（四枚）
水煎。去滓。温服。 治伤寒有五法。曰汗。曰吐。曰下。曰温。曰和。皆一定之法。而少
阳例中小柴胡汤。专一和解表里。少阳为阴阳交界。邪传至此。已渐向里。故用柴胡升发其邪。
使从外解。即以人参挡截于中。不令内犯。更以半夏、黄芩清解在里之热痰。生姜、大枣并祛在
表之邪气。又须甘草协辅参、柴。共襄匡正辟邪之功。真不易之法。无容拟议者也。其方后加减
。乃法中之法。定而不移。至于邪气犯本。胆府受病。而加龙骨、牡蛎。丸药误下。而加芒硝。
屡下不解。引邪入里。心下急。郁郁微烦。而用大柴胡。为法外之法。变通无定。不可思议者也
。独怪世医用小柴胡。一概除去人参。且必加枳、桔耗气之品。此非法之法。习俗相承。匿于横
议者也。何怪乎道艺日卑。风斯日下哉。
柴胡加龙骨牡蛎汤（玉函） 治少阳经邪。误下犯本。胸满惊烦。
小柴胡汤去黄芩、甘草。加桂枝、茯苓、龙骨、牡蛎、铅丹、大黄。
柴胡加芒硝汤（玉函） 治少阳过经不解。
小柴胡汤加芒硝三钱。
大柴胡汤（玉函） 治寒热便秘。
小柴胡汤去人参、甘草。加芍药、枳实各一钱。大黄二钱。
四逆散（玉函） 治热邪传入少阴厥逆。
小柴胡汤去人参、半夏、黄芩、姜、枣。加枳实、芍药等。分为散。饮服方寸匕。日三服。
凡病各有真假。真者易见。假者难辨。差之毫厘。迥乎冰炭。试以伤寒之厥逆辨之。其始病便见
者为直中寒厥。五六日热除而见者为传经热厥。寒厥真而热厥假也。热厥之治。惟四逆散得之。
细推其邪。从阳入阴必由少阳而达。亦无不由太阴竟入少阴之理。故首推柴胡为来路之引经。亦
借以为去路之向导。用枳实者。扫除中道。以修整正气复回之路也。夫阴为阳扰。阳被阴埋。舍
和别无良法。故又需芍药以和其营。甘草以和其胃。胃气和而真阳敷布。假证愈而厥逆自除。但
方后加减纷庞。寒热互用。非随证而推逆顺之机。难以语此。如悸。加桂枝。小便不利。加茯苓
。泄利下重。加薤白。皆阴为阳扰。随其攸利而开泄之。咳利。加五味、干姜。腹痛。加附子。
是阳被阴埋。急须焕发以克复之。与厥阴例中。当归四逆加吴茱萸同法。须知真证正治。假证间
取。总不出此方之模范也。至若二经热邪亢极而厥。自有大承气下夺之法。又非四逆散、当归四
逆之和法可例治也。
柴胡去半夏加栝蒌汤（金匮） 治疟多渴。
小柴胡汤去半夏加栝蒌根。
柴胡桂枝干姜汤（玉函 金匮名柴胡桂姜汤） 治疟寒多微有热。
小柴胡汤去人参、半夏、姜、枣。加桂枝、干姜、栝蒌根、牡蛎。（熬）
柴胡桂枝汤（玉函） 治太阳少阳并病合病。寒热及疟。
小柴胡汤加桂枝、芍药。（即小柴胡汤合桂枝汤）
柴胡四物汤 治妇人经行感冒。热入血室。
小柴胡汤合四物汤。
柴胡枳桔汤（一名枳桔柴胡汤） 治少阳寒热痞满。
小柴胡汤加枳壳、桔梗。
增损柴胡汤 治少阳血虚。寒热不止。
小柴胡汤去黄芩。加川芎、芍药、陈皮。
柴胡清肝散 治怒火憎寒发热。肝胆风热疮疡。
小柴胡汤去半夏、姜、枣。加山栀、川芎、连翘、桔梗。
人参败毒散（局方） 治时疫初起发热。及感冒发散后热不止。
小柴胡汤去半夏、黄芩、大枣。加茯苓、羌活、独活、前胡、川芎、枳壳、桔梗。 问时疫
初起。用人参败毒。得毋助邪为虐之患乎。又何以治非时寒疫。汗后热不止。详此二者。一为全
盛之毒。一为未尽之邪。胡一方可混治耶。盖时疫之发。或值岁气并临。或当水土疏豁。种种不侔。
然必入伤中土。土主百骸。无分经络。毒瓦斯流行。随虚辄陷。最难叵测。亟乘邪气未陷时。尽力
峻攻。庶克有济。其立方之妙。全在人参一味。力致开阖。始则鼓舞羌、独、柴、前各走其经。
而与热毒分解之门。继而调御津精血气各守其乡。以断邪气复入之路。与桂枝汤中芍药护营之意
不殊。如桂枝人参汤、小柴胡汤、参苏饮。未尝不用人参以协济表药成功也。但其所主。惟天行
大头。乃为合辙。加荆、防、牛蒡、薄
荷。名荆防败毒。为捻颈瘟。咽喉肿痛之专药。即上二证。在热毒既陷以后。及北方黑骨温等。
总与此方无预也。至若伤寒传变之邪。伏气郁发之证。泾渭攸分。略无交涉。而先哲尝借以治寒
疫汗后余热往往获效者。以非时之邪混厕经中。屡行疏表不应。邪伏幽隐不出。非藉人参之大力
不能载之外泄也。逮至疫痢昏热口噤。亦宜此方加陈仓米引领入胃。则毒随药化。得非人参辅佐
之力欤。独怪近世医流。偏谓人参助长邪气。除去不用。专行群队攻发。鼓激壮火飞腾。不至竭
绝真阴不已。兹缘同学质问。因祖述以政。
荆防败毒散 治大头虾蟆瘟证。
人参败毒散加荆芥、防风、薄荷、牛蒡子。
仓禀汤 治疫痢发热。
人参败毒散加陈仓米一撮。
清脾饮 治食疟脉实。溺赤便秘。
小柴胡汤去人参。加白术、青皮、浓朴、草果。 按清脾饮。清理脾家痰气宿滞。及蕴积少
阳经中风热之邪。乃于小柴胡中除去人参。益入青皮、白术、浓朴、草果一派克削之味。在藜藿
之人。固为相宜。若膏粱豢养柔脆者。即有留滞。亦难胜此。用者审之。
Treats Shaoyang syndrome (Shaoyang disease) caused by pathogenic invasion. Symptoms include alternating chills and fever, wiry pulse, hypochondriac pain, and vomiting.
Chai Hu (3 qian), Huang Qin, Ren Shen, Gan Cao (roasted, each 1 qian), Ban Xia (2 qian), Sheng Jiang (5 slices), Da Zao (4 pieces).
Decoct in water, remove dregs, and take warm.
There are five methods for treating Shanghan (Cold Damage): sweating, emesis, purgation, warming, and harmonizing. These are fixed principles. In the case of Shaoyang, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is specifically used to harmonize the exterior and interior. Shaoyang is the boundary between Yin and Yang; when pathogens transmit here, they gradually move inward. Therefore, Chai Hu is used to raise and disperse the pathogen, allowing it to resolve from the exterior. Ren Shen is used to intercept at the middle jiao, preventing internal invasion. Ban Xia and Huang Qin clear heat-phlegm within; Sheng Jiang and Da Zao dispel pathogens on the exterior. Furthermore, Gan Cao assists Ren Shen and Chai Hu to jointly achieve the goal of supporting healthy qi and expelling pathogens. This is indeed an unchangeable method, requiring no further discussion. The modifications listed after the formula are methods within methods, fixed and immovable. When pathogens invade the root and the Gallbladder organ is diseased, Long Gu (Dragon Bone) and Mu Li (Oyster Shell) are added. If mistaken purgation with pill medicine occurs, Mang Xiao (Mirabilite) is added. If repeated purgation fails to resolve the condition, drawing pathogens inward, causing urgency in the epigastrium and slight depression/irritability, Da Chai Hu Tang (Major Bupleurum Decoction) is used. This is a method beyond the standard rules, flexible and unpredictable. It is strange that modern physicians generally omit Ren Shen when using Xiao Chai Hu Tang and insist on adding Zhi Shi (Immature Bitter Orange) and Jie Geng (Platycodon Root), which deplete Qi. This is not the correct method but rather a custom passed down, hidden under criticism. No wonder medical skills decline daily and customs deteriorate.
Chai Hu Jia Long Gu Mu Li Tang (Bupleurum Plus Dragon Bone and Oyster Shell Decoction) [from *Yi Han Jing*]: Treats Shaoyang channel pathogens, where mistaken purgation causes pathogens to attack the root, resulting in chest fullness, palpitations, and irritability.
Xiao Chai Hu Tang minus Huang Qin and Gan Cao, plus Gui Zhi (Cinnamon Twig), Fu Ling (Poria), Long Gu, Mu Li, Qian Dan (Lead Monoxide), and Da Huang (Rhubarb).
Chai Hu Jia Mang Xiao Tang (Bupleurum Plus Mirabilite Decoction) [from *Yi Han Jing*]: Treats Shaoyang disease that has passed its course without resolution.
Xiao Chai Hu Tang plus Mang Xiao (3 qian).
Da Chai Hu Tang (Major Bupleurum Decoction) [from *Yi Han Jing*]: Treats alternating chills and fever accompanied by constipation.
Xiao Chai Hu Tang minus Ren Shen and Gan Cao, plus Shao Yao (Peony Root) and Zhi Shi (Immature Bitter Orange, each 1 qian), and Da Huang (2 qian).
Si Ni San (Four Reversal Powder) [from *Yi Han Jing*]: Treats cold extremities due to heat pathogens transmitting to Shaoyin.
Xiao Chai Hu Tang minus Ren Shen, Ban Xia, Huang Qin, Sheng Jiang, and Da Zao, plus Zhi Shi and Shao Yao, etc., made into powder. Take one cun bi with liquid, three times daily.
All diseases have true and false manifestations. True signs are easy to see; false signs are hard to distinguish. A slight error leads to results as opposite as ice and charcoal. Consider cold extremities in Shanghan: those appearing at the onset are direct transmission cold reversals (Zhi Zhong Han Jue); those appearing after five or six days when heat subsides are transmitted heat reversals (Chuan Jing Re Jue). Cold reversal is true; heat reversal is false. For treating heat reversal, only Si Ni San is appropriate. Carefully analyzing the pathogen, moving from Yang to Yin must pass through Shaoyang, and inevitably passes through Taiyin before entering Shaoyin. Thus, Chai Hu is first recommended as the guiding herb for the incoming pathogen and also serves as a guide for the outgoing pathogen. Zhi Shi is used to clear the middle pathway, repairing the route for healthy qi to return. When Yin disturbs Yang, and Yang is buried by Yin, there is no better method than harmonizing. Therefore, Shao Yao is needed to harmonize Ying (Nutrient) level, and Gan Cao to harmonize Stomach Qi. When Stomach Qi is harmonized, True Yang spreads, false signs heal, and cold extremities resolve. However, post-formula modifications are complex, mixing cold and hot herbs. Without deducing the mechanism of reversal based on symptoms, one cannot discuss this. For palpitations, add Gui Zhi; for difficult urination, add Fu Ling; for dysentery with heaviness below, add Xie Bai. These address Yin disturbed by Yang, opening and draining according to advantage. For cough with diarrhea, add Wu Wei Zi (Schisandra) and Gan Jiang (Dried Ginger); for abdominal pain, add Fu Zi (Aconite Root). These address Yang buried by Yin, urgently needing to awaken Yang to overcome Yin. This aligns with the method of Dang Gui Si Ni Jia Wu Zhu Yu Tang in Jueyin cases. Note that true conditions require direct treatment, while false conditions use indirect approaches, all following this formula's model. If heat pathogens in two channels become extreme causing reversal, Da Cheng Qi Tang (Major Order the Qi Decoction) for purgation is自有 (naturally indicated); this is not treatable by the harmonizing methods of Si Ni San or Dang Gui Si Ni Tang.
Chai Hu Qu Ban Xia Gua Lou Tang (Bupleurum Decoction minus Pinellia plus Trichosanthes Root) [from *Jin Gui Yao Lue*]: Treats malaria with excessive thirst.
Xiao Chai Hu Tang minus Ban Xia, plus Gua Lou Gen (Trichosanthes Root).
Chai Hu Gui Zhi Gan Jiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) [from *Yi Han Jing*, named Chai Hu Gui Jiang Tang in *Jin Gui Yao Lue*]: Treats malaria with predominant chills and slight fever.
Xiao Chai Hu Tang minus Ren Shen, Ban Xia, Sheng Jiang, and Da Zao, plus Gui Zhi, Gan Jiang, Gua Lou Gen, and Mu Li (stir-fried).
Chai Hu Gui Zhi Tang (Bupleurum and Cinnamon Twig Decoction) [from *Yi Han Jing*]: Treats concurrent Shaoyang and Taiyang diseases, alternating chills and fever, and malaria.
Xiao Chai Hu Tang plus Gui Zhi and Shao Yao. (This is Xiao Chai Hu Tang combined with Gui Zhi Tang).
Chai Hu Si Wu Tang (Bupleurum Four Substances Decoction): Treats women catching cold during menstruation, with heat entering the Blood Chamber.
Xiao Chai Hu Tang combined with Si Wu Tang (Four Substances Decoction).
Chai Hu Zhi Jie Tang (Bupleurum, Immature Bitter Orange, and Platycodon Decoction) (also known as Zhi Jie Chai Hu Tang): Treats Shaoyang alternating chills and fever with epigastric fullness.
Xiao Chai Hu Tang plus Zhi Ke (Aurantii Fructus) and Jie Geng.
Zeng Sun Chai Hu Tang (Modified Bupleurum Decoction): Treats Shaoyang blood deficiency with persistent alternating chills and fever.
Xiao Chai Hu Tang minus Huang Qin, plus Chuan Xiong (Szechwan Lovage Rhizome), Shao Yao, and Chen Pi (Tangerine Peel).
Chai Hu Qing Gan San (Bupleurum Liver-Clearing Powder): Treats aversion to cold and fever due to anger/fire, and sores/ulcers due to wind-heat in Liver and Gallbladder.
Xiao Chai Hu Tang minus Ban Xia, Sheng Jiang, and Da Zao, plus Shan Zhi (Gardenia Fruit), Chuan Xiong, Lian Qiao (Forsythia Fruit), and Jie Geng.
Ren Shen Bai Du San (Ginseng Detoxifying Powder) [from *Ju Fang*]: Treats initial fever of seasonal epidemics, and persistent fever after diaphoresis for common cold.
Xiao Chai Hu Tang minus Ban Xia, Huang Qin, and Da Zao, plus Fu Ling, Qiang Huo (Notopterygium Rhizome), Du Huo (Angelica Pubescens Root), Qian Hu (Peucedanum Root), Chuan Xiong, Zhi Ke, and Jie Geng. Question: Using Ren Shen Bai Du San at the onset of epidemic febrile disease, does it not risk assisting the pathogen? How can it treat non-seasonal cold epidemics with persistent fever after sweating? Analyzing these two cases: one involves full-strength toxic pathogens; the other, lingering pathogens. How can one formula treat both indiscriminately? Epidemics arise from specific annual climates or geographical factors, varying greatly. However, they invariably damage the Middle Jiao (Earth), which governs the body regardless of meridians. Toxic vapors circulate and sink into deficiencies, making them unpredictable. One must aggressively attack while pathogens have not yet sunk. The brilliance of this formula lies entirely in Ren Shen, which controls opening and closing. Initially, it boosts Qiang Huo, Du Huo, Chai Hu, and Qian Hu to traverse their respective channels, opening pathways for heat-toxin resolution. Subsequently, it regulates fluids, essence, blood, and Qi to guard their territories, cutting off paths for pathogen re-entry. This parallels the protective Ying-nourishing intent of Shao Yao in Gui Zhi Tang. Similarly, Gui Zhi Ren Shen Tang, Xiao Chai Hu Tang, and Shen Su Yin all use Ren Shen to assist exterior-resolving herbs. However, this formula is specifically suited for Tian Xing Da Tou Wen (Epidemic Large Head Plague). Adding Jing Jie (Schizonepeta), Fang Feng (Saposhnikovia), Niu Bang Zi (Arctium Seed), and Bo He (Mint) creates Jing Fang Bai Du San, a specific remedy for Nian Jing Wen (Neck-Twisting Plague) and sore throat/swelling. For the aforementioned conditions, once heat-toxins have sunk, or for Northern Black Bone Wen, this formula is irrelevant. Pathogens from Shanghan transmission and latent Qi郁发 (depression and eruption) are distinct and unrelated. Ancients used this for residual heat after sweating in cold epidemics because non-seasonal pathogens mixed in meridians resisted surface-dispersing attempts; they were hidden and required Ren Shen's strong power to carry them out. For epidemic dysentery with coma, fever, and locked jaw, adding Chen Cang Mi (Old Rice) guides the formula to the Stomach, transforming toxins. Is this not the power of Ren Shen's assistance? Strangely, modern physicians claim Ren Shen aids pathogens and omit it, relying solely on aggressive dispersing groups, stirring up vigorous fire until True Yin is exhausted. Responding to student inquiries, I recount these ancestral views.
Jing Fang Bai Du San (Schizonepeta and Saposhnikovia Detoxifying Powder): Treats Da Tou Xia Ma Wen (Large Head Toad Plague).
Ren Shen Bai Du San plus Jing Jie, Fang Feng, Bo He, and Niu Bang Zi.
Cang Lin Tang (Granary Storehouse Decoction): Treats epidemic dysentery with fever.
Ren Shen Bai Du San plus a pinch of Chen Cang Mi.
Qing Pi Yin (Clear Spleen Drink): Treats food-type malaria with solid pulse, red urine, and constipation.
Xiao Chai Hu Tang minus Ren Shen, plus Bai Zhu (Atractylodes Macrocephala Rhizome), Qing Pi (Aurantii Fructus Pericarpium), Hou Po (Magnolia Bark), and Cao Guo (Tsaoko Cardamom). Commentary: Qing Pi Yin clears phlegm, Qi stagnation, and old retention in the Spleen, as well as wind-heat pathogens accumulated in the Shaoyang channel. By removing Ren Shen from Xiao Chai Hu Tang and adding Qing Pi, Bai Zhu, Hou Po, and Cao Gu—agents of reduction—it suits those of simple diet. However, for those nourished on rich foods with delicate constitutions, even if retention exists, they may not tolerate this harsh formula. Users should exercise caution.