浓朴（姜汤炒） 陈皮（去白） 半夏（制） 藿香（去梗） 苍术（制） 甘草（炙）
凡受山岚瘴气及出远方不服水土，吐泻下利者，此方主之。
山岚瘴气，谷气也。《内经》曰∶谷气通于脾，故令人不服水土而坏腹。是方也，苍术
、浓朴、陈皮、甘草，前之平胃散也，可以平湿土敦阜之气而消岚瘴。乃半夏之燥，所以醒
脾；藿香之芬，所以开胃。方名曰正气者，谓其能正不正之气故尔！
叙曰∶瘟疫以六淫致疾，证状各各不同，自非良医，鲜有明者。吾尝执贽远迩而求学益
，叩及瘟疫诸证，即擅名之士犹讷焉。今考方十二首，详辨其证，庶几乎活人之补也。
羌活 独活 柴胡 前胡 川芎 黄芩 桔梗 枳壳 人参 茯苓 甘草
壮热，不恶风寒而渴者，瘟病也，此方主之。
冬时触冒寒气，即病者名曰伤寒，不即病者，寒毒藏于肌肤，至春变为温病，至夏变为
热病，以其阳毒最深，名曰瘟疫。寒变为温为热，故病壮热，不恶风寒而渴也。经曰∶治温
以清；又曰∶开之发之，适事为故。羌活、独活、柴胡、前胡、川芎，皆轻清开发之剂也，
故用之以解壮热；用黄芩、枳壳、桔梗者，取其清膈而利气也；用人参、茯苓、甘草者，实
其中气，使瘟毒不能深入也。培其正气，败其邪毒，故曰败毒。
厚朴（用姜汁炒制） 陈皮（去除白色内层） 半夏（经过炮制） 藿香（去除茎梗） 苍术（经过炮制） 甘草（炙烤）
凡是受到山间雾气瘴气侵袭，以及去往远方不适应当地水土环境，出现呕吐、腹泻或痢疾症状的人，此方主治。
山岚瘴气，即山谷中的湿气。《黄帝内经》说：谷气与脾相通，所以使人不适应水土而导致腹部病变。这个方剂中，苍术、厚朴、陈皮、甘草，是之前的平胃散（Pingwei San, Aromatic Damp-Resolving Powder），能够平抑湿土壅盛之气而消除岚瘴。至于半夏的燥性，是用来醒脾；藿香的芳香，是用来开胃。方子命名为“正气”，是说它能够纠正不正之气！
序言说：瘟疫是由六淫（风、寒、暑、湿、燥、火六种外感病邪）致病，证状各不相同，如果不是良医，很少能明辨。我曾经携带礼物向远近名医求学请教，问到关于瘟疫的各种证候时，即使是享有盛名的医生也显得沉默寡言。如今考证了十二首方剂，详细辨析其证候，或许对救人有所补益。
羌活 独活 柴胡 前胡 川芎 黄芩 桔梗 枳壳 人参 茯苓 甘草
高热，不恶风寒且口渴的，是瘟病，此方主治。
冬天触犯冒犯寒气，立即发病的叫伤寒；没有立即发病的，寒毒潜伏在肌肤之间，到春天变为温病，到夏天变为热病，因为其中的阳毒最深，叫做瘟疫。寒邪转化为温邪、热邪，所以病症表现为高热，不恶风寒且口渴。经文说：治疗温病要用清法；又说：用发散的方法，以适合病情为准则。羌活、独活、柴胡、前胡、川芎，都是轻清开发的药剂，所以用来解除高热；使用黄芩、枳壳、桔梗，是取其清利膈部气机的作用；使用人参、茯苓、甘草，是为了充实中气，使瘟毒不能深入体内。培补人体的正气，败退邪毒，所以称为败毒。
Houpo (Cortex Magnoliae Officinalis, stir-baked with ginger juice) Chenpi (Pericarpium Citri Reticulatae, white pith removed) Banxia (Rhizoma Pinelliae Preparatum, processed) Huoxiang (Herba Agastaches, stems removed) Cangzhu (Rhizoma Atractylodis Lanceae, processed) Gancao (Radix Glycyrrhizae, honey-fried)
For those who have been affected by mountain miasma and dampness, or who suffer from maladaptation to local water and soil after traveling to distant places, presenting with vomiting, diarrhea, or dysentery, this formula is indicated.
Mountain miasma refers to the dampness of valleys. The *Neijing* states: "Valley qi connects with the Spleen," thus causing maladaptation to water and soil and abdominal disorders. In this formula, Cangzhu, Houpo, Chenpi, and Gancao constitute the previous Pingwei San (Aromatic Damp-Resolving Powder), which can level the excessive qi of damp-earth and eliminate miasma. The drying property of Banxia serves to awaken the Spleen; the aromatic nature of Huoxiang serves to open the Stomach. The formula is named "Zhengqi" (Correct Qi) because it can rectify aberrant qi.
Preface: Epidemic febrile diseases are caused by the Six Excesses (Wind, Cold, Summerheat, Dampness, Dryness, Fire), and their manifestations vary greatly. Without being a skilled physician, few can clearly distinguish them. I once traveled far and wide carrying gifts to seek learning. When questioned about various epidemic syndromes, even renowned physicians remained taciturn. Now, having examined twelve formulas and detailed the differentiation of syndromes, this may serve as a supplement for saving lives.
Qianghuo (Rhizoma et Radix Notopterygii) Duhuo (Radix Angelicae Pubescentis) Chaihu (Radix Bupleuri) Qianhu (Radix Peucedani) Chuanxiong (Rhizoma Chuanxiong) Huangqin (Radix Scutellariae) Jiegeng (Radix Platycodi) Zhike (Fructus Aurantii Immaturus) Renshen (Radix Ginseng) Fuling (Poria) Gancao (Radix Glycyrrhizae)
High fever without aversion to wind or cold, accompanied by thirst, indicates an epidemic disease; this formula is indicated.
If one contracts cold pathogenic factors in winter and falls ill immediately, it is called Cold Damage (Shanghan). If illness does not occur immediately, the cold toxin hides in the skin and muscles. By spring, it transforms into Warm Disease (Wenbing); by summer, it transforms into Heat Disease. Because the yang toxin is deepest, it is called Plague/Epidemic Febrile Disease (Wenyi). Since cold transforms into warm and heat, the syndrome manifests as high fever, absence of aversion to wind/cold, and thirst. The classics state: "Treat warm diseases with clearing methods"; and again: "Use opening and dispersing methods, appropriate to the situation." Qianghuo, Duhuo, Chaihu, Qianhu, and Chuanxiong are all light, clear, and dispersing agents, used here to resolve high fever. Huangqin, Zhike, and Jiegeng are used for their ability to clear the diaphragm and promote qi flow. Renshen, Fuling, and Gancao are used to fortify the Middle Qi, preventing the epidemic toxin from penetrating deeply. By cultivating the body's Correct Qi and defeating the evil toxin, it is named "Baidu" (Defeating Toxin).