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。
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).