日月星辰，天之有象可睹；水火土石，地之有形可求；昆虫草木，动植之物可见
；寒热温凉，四时之气往来可觉。至于山岚瘴气，岭南毒雾，咸得地之浊气，犹或可察。而
惟天地之杂气，种种不一，亦犹天之有日月星辰，地之有水火土石，气交之中有昆虫草木之不一也。草木有野葛巴豆，
星辰有罗计荧惑，昆虫有毒蛇猛兽，土石
有雄、硫、 、信，万物各有善恶不等，是知杂气之毒有优劣也。然气无所可求，无
象可见，况无声复无臭
，何能得睹得闻？人恶得而知气？又恶得而知其气之不一也？是气也，其来无时，其着无方，众人有触之者，各随其气
而
为诸病焉。其为病也，或时众人发颐；或时众人头面浮肿，俗名为大头瘟是也；或时众人咽
痛，或时音哑，俗名为是虾蟆瘟是也；或时众人疟痢；或为痹气，或为痘疮，或为斑疹，或
为疮疥疔 ，或时众人目赤肿痛；或时众人呕血暴下，俗名为瓜瓤瘟，探头瘟是也；或时众
人瘿 、俗名为疙瘩瘟是也。为病种种，难以枚举。大约病偏于一方，
延门阖户，众人相同
，皆时行之气，即杂气为病也。为病种种是知气之不一也。盖当时，适有某气专入某脏腑
其经络，专发为某病，故众人之病相同，是知气之不一，非关脏腑经络或为之证也。夫病不可以年岁四时为拘，盖
非
五运六气所即定者，是知气之所至无时也。或发于城市，或发于村落，他处安然无有，是知
气之所着无方也。疫气者亦杂气中之一，但有甚于他气，故为病颇重，因名之疠气。虽有多
寡不同，然无岁不有。至于瓜瓤瘟、疙瘩瘟，缓者朝发夕死，急者顷刻而亡，此在诸疫之最
重
者。幸而几百年来罕有之证，不可以常疫并论也。至于发颐、咽痛、目赤、斑疹之类，其时村
落中偶有一、二人所患者，虽不与众人等，然考其证，甚合某年某处众人所患之病纤悉相同
，
治法无异。此即当年之杂气，但目今所钟不浓，所患者稀少耳。此又不可以众人无有，断为
非杂气也。况杂气为病最多，然举世皆误认为六气。假如误认为风者，如大麻风、鹤膝风、痛
风、历节风、老人中风、肠风、疠风、痫风之类，概用风药，未尝一效，实非风也，皆杂气为病耳
。至又误认为火者，如疔疮、发背、痈疽、肿毒、气毒流注、流火、丹毒，与夫发斑、痘疹之类，以为
痛痒疮疡皆属心火，投芩、连、栀、柏未尝一效，实非火也，亦杂气之所为耳。至于误认为
暑者，如霍乱、吐、泻、疟、痢、暴注、腹痛、绞肠痧之类，皆误认为暑，因作暑证治之，未
尝一效，与暑何与焉！至于一切杂证，无因而生者，并皆杂气所成。从古未闻者何耶？盖因诸气来而不知，感
而不觉，惟向风寒暑湿所见之气求之，是舍无声无臭、不睹不闻之气推察。既错认病原，未免误投他药。《大易》所谓∶
或系之牛，行人之得，邑人之灾也。刘河间作《原病式》
，盖
祖五运六气，百病皆原于风、寒、暑、湿、燥、火，是无出此六气为病。实不知杂气为病，
更多于六气为病者百倍，不知六气有限，现下可测，杂气无穷，茫然不可测也。专务六气，不言杂气，焉能包
括天下之病欤！
日月星辰，是天空中可以看见的形象；水火土石，是大地中具有形体的物质；昆虫草木，是动物和植物中可见的生命。寒热温凉，是四季气候的交替变化，人们可以感知到。至于山间的雾气、瘴气，岭南地区的毒雾，都是大地产生的浊气，尚且还可以被察觉。唯独天地之间的“杂气”，种类繁多，各不相同，就像天空中有日月星辰，大地中有水火土石，在气交之中有各种各样的昆虫草木一样。
草木中有野葛、巴豆等有毒之物，星辰中有罗睺、计都、荧惑等凶星，昆虫中有毒蛇、猛兽等有害生物，土石中有雄黄、硫磺、砒霜、信石等矿物毒物，万物各有善恶优劣之分，由此可知杂气的毒性也有轻重优劣之别。然而这种气无法通过形体去寻求，没有形象可见，况且它既没有声音也没有气味，怎么能被看见或听见呢？人又怎么能知道它的存在？又怎么知道它有多种不同呢？这种气，发作没有固定的时间，侵犯人体没有固定的部位，众人只要接触到它，就会随着所感之气的不同而引发各种疾病。
这些疾病的表现，有时是众人同时发生腮部肿胀（发颐）；有时是众人头面部浮肿，俗称“大头瘟”；有时是众人咽喉疼痛，有时声音嘶哑，俗称“蛤蟆瘟”；有时是众人患疟疾、痢疾；有的表现为痹症，有的表现为痘疮，有的表现为斑疹，有的表现为疮疥疔疮；有时是众人眼睛红肿疼痛；有时是众人呕血、暴泻，俗称“瓜瓤瘟”、“探头瘟”；有时是众人颈部生瘿瘤，俗称“疙瘩瘟”。引发的病症多种多样，难以一一列举。大致来说，如果疾病偏向于某一地区，导致满门万户、众人患病情况相同，这都是时行疫气，也就是由杂气引起的疾病。从病症种类繁多这一事实，就可以知道杂气是多种多样的。
大概是因为当时恰好有一种特定的杂气专门侵入某人的脏腑经络，专门引发某种特定的疾病，所以众人的病情相同。这证明了杂气的多样性，而不是因为脏腑经络本身导致了这些证候。疾病的发生不能拘泥于年份和四季，因为它不是由五运六气所固定决定的，由此可知杂气到来的时间是不固定的。有时在城市爆发，有时在村落爆发，其他地方安然无恙，由此可知杂气侵犯的部位是没有固定方向的。
疫气也是杂气中的一种，只是比其他的杂气毒性更重，所以称为“疠气”。虽然发病人数有多有少，但每年都有发生。至于像瓜瓤瘟、疙瘩瘟这类疾病，轻的早晨发作晚上死亡，重的顷刻间就死亡，这是所有疫病中最严重的。幸好几百年来很少见到这样的病例，不能把它当作普通的疫病来讨论。至于像发颐、咽痛、目赤、斑疹这类疾病，当时在村落中偶尔有一两个人患病的，虽然不像众人那样普遍，但是考察其症状，与某年某地众人所患的疾病完全相同，治疗方法也没有差异。这就是当年的杂气，只是目前聚集的浓度不浓，患病的人稀少罢了。这又不能因为众人没有患病，就断定不是杂气引起的。
况且杂气引起的疾病最多，然而世人都错误地将其认为是“六气”（风、寒、暑、湿、燥、火）。假如误认为是风邪，如大麻风、鹤膝风、痛风、历节风、老人中风、肠风、疠风、痫风等，一概使用祛风药物治疗，从未见效，实际上并不是风邪，都是杂气引起的疾病。又假如误认为是火邪，如疔疮、发背、痈疽、肿毒、气毒流注、流火、丹毒，以及发斑、痘疹等，认为疼痛瘙痒的疮疡都属于心火，投用黄芩、黄连、栀子、黄柏等清热药，从未见效，实际上也不是火邪，也是杂气造成的。至于误认为是暑邪的，如霍乱、呕吐、腹泻、疟疾、痢疾、急性腹泻、腹痛、绞肠痧等，都误认为是暑邪，按照暑证治疗，从未见效，这与暑邪有什么关系呢！
至于一切没有明显原因而发生的杂病，都是由杂气形成的。为什么从古至今没有听说过呢？大概是因为各种杂气袭来时人们不知道，感染时人们没有感觉，只向风寒暑湿这些可见可感的气去寻找病因，这是在舍弃无声无臭、看不见听不到的气而去推究。既然错认了病原，难免误投其他药物。《易经》所说的：“有人系着的牛，被过路人牵走了，同乡人却遭受了灾祸。”刘河间撰写《原病式》，以五运六气为祖述，认为百病都源于风、寒、暑、湿、燥、火，没有超出这六气致病范围的。其实并不知道杂气致病，比六气致病的数量多百倍，不知道六气是有限的、现在可以测定的，而杂气是无穷无尽的、茫然不可测度的。专门致力于研究六气，而不谈论杂气，怎么能包括天下的所有疾病呢！
The sun, moon, and stars are phenomena in the sky that can be seen; water, fire, earth, and stones are tangible forms on the earth that can be sought; insects and plants are visible entities among animals and flora. The cold, heat, warmth, and coolness of the four seasons represent the cycle of climatic qi (vital energy), which can be perceived. As for mountain mists, miasmas, and toxic fogs in Lingnan, these are all turbid qi generated by the earth, yet they can still be observed. However, the "miscellaneous qi" (Za Qi, 杂气) of heaven and earth is diverse and varied, just as there are sun, moon, and stars in the sky, water, fire, earth, and stones on the ground, and various insects and plants in the realm where qi interacts.
Among plants, there are wild gelsemium (Ye Ge) and croton seeds (Ba Dou); among stars, there are malefic stars like Luo Hou and Ji Du; among insects, there are venomous snakes and fierce beasts; among earth and stones, there are minerals like realgar (Xiong Huang), sulfur (Liu Huang), arsenic trioxide (Pi Shuang), and stibnite (Xin Shi). All things have their good and evil, superior and inferior qualities; thus, we know that the toxicity of miscellaneous qi also varies in severity. Yet this qi cannot be sought through form, nor can it be seen, let alone heard or smelled. How then can it be perceived? How can humans know its existence, or know that it exists in many different forms? This qi arrives without fixed timing and strikes without fixed location. When people come into contact with it, they develop various diseases according to the specific qi they encounter.
These diseases may manifest as simultaneous swelling of the parotid glands (Fa Yi) in a group of people; or simultaneous edema of the head and face, commonly known as "Big Head Plague" (Da Tou Wen); or simultaneous sore throat, sometimes with hoarseness, commonly known as "Toad Plague" (Ha Ma Wen); or simultaneous malaria and dysentery; or bi-syndrome (Bi Qi), smallpox (Dou Chuang), macules and papules (Ban Zhen), sores, scabies, and carbuncles (Ding); or simultaneous red, swollen, and painful eyes; or simultaneous hematemesis and sudden diarrhea, commonly known as "Melon Rind Plague" (Gua Rang Wen) and "Probing Head Plague" (Tou Tou Wen); or simultaneous goiters (Ying), commonly known as "Lump Plague" (Ge Da Wen). The variety of diseases is too numerous to list. Generally, if a disease is confined to a specific region, affecting entire households and groups of people identically, it is due to epidemic qi (Shi Xing Zhi Qi), which is essentially disease caused by miscellaneous qi. The diversity of diseases proves the diversity of the qi.
It is likely that at that time, a specific type of miscellaneous qi specifically entered certain organs and meridians, causing a specific disease, hence the similarity in symptoms among the infected. This confirms the diversity of the qi, rather than implying that the organs and meridians themselves determine the syndrome. Diseases cannot be constrained by years or seasons, as they are not fixed by the Five Movements and Six Qi (Wu Yun Liu Qi). Thus, the arrival of the qi is unpredictable. It may erupt in cities or villages, while other places remain safe, proving that the qi strikes without fixed location. Epidemic qi (Yi Qi) is one type of miscellaneous qi, but it is more potent, hence called "pestilential qi" (Li Qi). Although the number of cases varies, it occurs every year. Diseases like Melon Rind Plague and Lump Plague are the most severe; mild cases may die from morning to evening, and acute cases may die within moments. Fortunately, such cases have been rare for hundreds of years and should not be compared to common epidemics.
Regarding diseases like parotid swelling, sore throat, red eyes, and rashes, even if only one or two individuals in a village are affected at a given time, their symptoms closely match those of the widespread outbreaks in previous years, and the treatment methods are identical. This is the same miscellaneous qi, but currently, the concentration is low, and few are infected. One cannot conclude it is not miscellaneous qi simply because most people are unaffected. Moreover, miscellaneous qi causes the majority of diseases, yet the world mistakenly attributes them to the "Six Qi" (Wind, Cold, Summer-heat, Dampness, Dryness, Fire). For instance, mistaking wind pathogen for conditions like leprosy (Da Ma Feng), knee deformity (He Xi Feng), gout (Tong Feng), migratory joint pain (Li Jie Feng), stroke in the elderly (Zhong Feng), intestinal wind (Chang Feng), leprous wind (Li Feng), and epileptic wind (Xian Feng), and treating them all with wind-dispelling herbs yields no effect, as they are not wind but miscellaneous qi. Mistaking fire pathogen for conditions like carbuncles (Ding Chuang), back abscesses (Fa Bei), ulcers (Yong Ju), swellings (Zhong Du), flowing toxins (Liu Zhu), flowing fire (Liu Huo), erysipelas (Dan Du), and rashes/smallpox, and assuming all painful/itchy sores belong to Heart Fire, and treating them with Scutellaria (Huang Qin), Coptis (Huang Lian), Gardenia (Zhi Zi), and Phellodendron (Huang Bai) yields no effect, as they are not fire but miscellaneous qi. Mistaking summer-heat for cholera (Huo Luan), vomiting, diarrhea, malaria, dysentery, acute diarrhea (Bao Zhu), abdominal pain, and intestinal cramping (Jiao Chang Sha), and treating them as summer-heat syndromes yields no effect, as they have nothing to do with summer-heat.
All miscellaneous disorders arising without obvious cause are formed by miscellaneous qi. Why were they unknown in ancient times? Because when these qis arrive, people do not perceive them; when infected, they feel nothing. People only seek causes in the visible and perceptible Wind, Cold, Summer-heat, and Dampness, ignoring the silent, odorless, invisible, and inaudible qi. Having misidentified the pathogen, they inevitably administer wrong medicines. As stated in the *I Ching* (Book of Changes): "A cow tied up is taken by a traveler, bringing disaster to the villagers." Liu Hejian wrote *Yuan Bing Shi* (Tracing the Origins of Diseases), basing his theory on the Five Movements and Six Qi, asserting that all diseases originate from Wind, Cold, Summer-heat, Dampness, Dryness, and Fire, with no exceptions. He failed to realize that diseases caused by miscellaneous qi are a hundred times more numerous than those caused by the Six Qi. He did not understand that the Six Qi are limited and measurable, whereas miscellaneous qi is infinite and immeasurable. Focusing solely on the Six Qi while ignoring miscellaneous qi cannot possibly encompass all diseases under heaven!