仲景之书，原有十六卷，今世只传十卷，岂疫疹一门，亦在遗亡之数欤？以致后世立说纷纷。至河间清热解毒之论
出，有高人之见，异人之识，其旨既微，其意甚远，后人未广其说，而反以为偏。《冯氏锦囊》亦云∶斑疹不可发表，此
所谓大中至正之论。惜未畅明其旨，后人何所适从？又可辨疫甚析。如头痛、发热、恶寒，不可认为伤寒表证，强发其
汗，徒伤表气。热不退，又不可下，徒伤胃气。斯语已得其奥妙。奈何以疫气从口鼻而入，不传于胃而传于膜原，此论
似有语病。至用达原饮、三消诸承气，犹有附会表里之意。惟熊恁昭《热疫志验》，首用败毒散去其爪牙，继用桔梗汤同
为舟楫之剂，治胸膈手六经邪热，以手足少阳俱下膈络胸中，三焦之气为火，同相火游行一身之表，膈与六经乃至高之
分，此药浮载亦至高之剂，施于无形之中，随高下而退胸膈及六经之热，确系妙方。汪按∶败毒散似未尽妥究宜慎用。
余今采用其法，减去硝、黄，以热疫乃无形之毒，难以当其猛烈，重用石膏，直入肺胃，先捣其窝巢之害，而十二经之
患自易平矣，无不屡试屡验，明者察之。
疹出于胃。古人言∶热未入胃而下之，热乘虚入胃，故发斑。热已入胃，不即下之，热不得泄，亦发斑，此指寒邪
化热，误下、失下而言。若疫疹未经表下，有热不一日而即发者，故余谓热疫有斑疹，伤寒无斑疹也。热疫之斑疹发之
愈迟，其毒愈重。一病即发，以其胃本不虚，偶染疫邪，不能入胃，犹之墙垣高硕，门户紧密，虽有小人，无从而入。
此又可所谓达于膜原者也。有迟至四五日而仍不透者，非胃虚受毒已深，即发表攻里过当。胃为十二经之海，上下十二
经，都朝宗于胃，胃能敷布十二经，荣养百骸，毫发之间，靡所不贯，毒既入胃，势必敷布于十二经，残害百骸，使不
有以杀其炎炎之势，则百骸受其煎熬，不危何待？疫既曰毒，其为火也明矣。火之为病，其害甚大，土遇之而焦，金遇
之而熔，木遇之而焚，水不能胜则涸。故《易》曰∶“燥万物者，莫 乎火”，古人所谓元气之贼也。以是知火者疹之根，
疹者火之苗也。如欲其苗之外透，非滋润其根，何能畅茂？一经表散燔灼火焰，如火得风，其焰不愈炽乎？焰愈炽，苗
愈遏矣。疹之因表而死者，比比然也。其有表而不死者，乃麻疹、风疹之类。有谓疹可治而斑难治者，殆指疫疹为斑耳！
夫疫疹亦何难治哉，但人不知用此法也。
张仲景的著作，原本有十六卷，如今世间只流传十卷，难道疫病和疹病这一门类，也包含在散佚的数量之中吗？导致后世医家立说纷纭。直到刘河间提出清热解毒的理论，具有高人的见解、异人的见识，其宗旨既精微，其意蕴又深远，后人未能广泛发扬这一学说，反而认为它偏颇。《冯氏锦囊》也说：斑疹不可使用发表法，这可以说是大中至正的理论。可惜没有详尽阐明其旨意，后人无所适从？余又可对疫病的辨析非常细致。例如头痛、发热、恶寒，不能认为是伤寒表证，强行发汗，只会徒然损伤表气。热不退，又不能攻下，只会徒然损伤胃气。这些话已经抓住了奥妙。奈何他认为疫气从口鼻而入，不传于胃而传于膜原，这一论点似乎有语病。至于使用达原饮、三消诸承气汤等方剂，仍然带有附会表里之意的嫌疑。只有熊恁昭的《热疫志验》，首先使用败毒散去其爪牙（指邪气的依附或势力），继而又用桔梗汤作为舟楫之剂（载药上行），治疗胸膈及手六经的邪热，因为手足少阳经都下膈络属胸中，三焦之气属于火，与相火一同游行于全身之表，膈部与六经处于至高之分，这些药物浮载也是至高之剂，施用于无形之中，随着高下之势退去胸膈及六经的热邪，确实是妙方。汪按：败毒散似乎未尽妥当，应当慎用。我现在采用他的方法，减去芒硝、大黄，因为热疫是无形的毒邪，难以承受猛烈之药，重用石膏，直入肺胃，先捣毁其窝巢的危害，那么十二经的病患自然容易平复了，无不屡试屡验，明眼人请察考。
疹出于胃。古人说：热邪未入胃就攻下，热邪乘虚入胃，所以发斑。热邪已入胃，不及时攻下，热邪不得泄出，也会发斑，这是指寒邪化热，误下或失下而言。如果疫疹未经过发表或攻下，有热邪不到一天就发作的，所以我说是热疫有斑疹，伤寒无斑疹。热疫的斑疹发得越迟，其毒邪越重。一发病就发作，是因为胃本不虚，偶然感染疫邪，不能入胃，就像墙垣高大厚实，门户紧密，虽然有小人，也无从进入。这就是余又可所说的达于膜原的情况。有的迟至四五天仍不透发，不是胃虚受毒已深，就是发表攻里太过当。胃是十二经之海，上下十二经，都朝宗于胃，胃能敷布十二经，荣养百骸，毫发之间，无所不贯，毒邪既然入胃，势必敷布于十二经，残害百骸，如果不采取措施杀灭其炎炎之势，那么百骸将受其煎熬，不危险还等什么？疫病既然是毒，其为火也就很明白了。火造成的病患，危害很大，土遇到它就焦枯，金遇到它就熔化，木遇到它就焚烧，水不能胜过它就干涸。所以《易经》说：“燥万物者，莫熯乎火”，古人所说的元气之贼。由此可知火是疹的根本，疹是火的苗头。如果想要它的苗头外透，不滋润它的根本，怎么能茂盛？一经表散燔灼火焰，就像火得到风，火势不更加炽烈吗？火势越炽烈，苗头越被遏制。疹因表散而死的，比比皆是。那些表散而不死的，乃是麻疹、风疹之类。有人说疹可治而斑难治，大概是指疫疹为斑吧！那疫疹又有什么难治的呢，只是人们不知道用这种方法罢了。
The works of Zhang Zhongjing originally consisted of sixteen volumes, yet only ten volumes are currently transmitted in the world. Could it be that the category of epidemic diseases and rashes (Yi Zhen) is also among those lost? This has led to numerous conflicting theories in later generations. It was not until Liu Hejian proposed the theory of clearing heat and detoxifying (Qing Re Jie Du), demonstrating profound insight and unique understanding, with principles that were both subtle and far-reaching, that a solid foundation was laid. However, later practitioners failed to expand upon this theory and instead regarded it as biased. *Feng Shi Jin Nang* also stated: "Rashes and macules should not be treated with diaphoresis (Fa Biao)." This can be considered a theory of great centrality and correctness. Alas, its essence was not fully elucidated, leaving later generations unsure of what to follow. Yu Yuke's differentiation of epidemics was very detailed. For instance, regarding headache, fever, and aversion to cold, one must not mistake them for exterior syndromes of Cold Damage (Shang Han) and forcibly induce sweating, which would merely damage the exterior Qi. If the heat does not subside, purgation should not be used, as it would merely damage Stomach Qi. These words have grasped the subtleties. However, his assertion that epidemic Qi enters through the mouth and nose, bypassing the Stomach to transmit to the Membrane Source (Mo Yuan), seems flawed. The use of Da Yuan Yin and various Cheng Qi Decoctions for three purgations still carries an element of forced association with exterior-interior relationships. Only Xiong Nen Zhao's *Re Yi Zhi Yan* first employed Baidu San to remove the "claws and teeth" (the support of the pathogen), followed by Jiegeng Tang acting as a carrier agent (Zhou Ji) to treat pathogenic heat in the chest-diaphragm area and the Hand Six Meridians. Since the Hand and Foot Shaoyang meridians pass below the diaphragm and connect to the chest, and the San Jiao Qi belongs to Fire, traveling with Ministerial Fire throughout the exterior of the body, the diaphragm and the Six Meridians occupy the highest positions. These floating and lifting agents are also high-positioned prescriptions; applied within the formless realm, they retreat the heat of the chest-diaphragm and Six Meridians according to their height, truly being excellent formulas. Wang's commentary notes: Baidu San seems not entirely appropriate and should be used with caution. I now adopt his method, removing Mang Xiao (Mirabilite) and Huang Lian/Rhubarb (here implied as Da Huang, Rhubarb Root and Tuber, though text says 硝黄 usually Mirabilite and Rhubarb), because Heat Epidemic involves formless toxic pathogens, which cannot withstand猛烈 (fierce) medicines. By heavily using Shi Gao (Gypsum Fibrosum), entering directly into the Lung and Stomach, we first destroy the nest of harm, making the ailments of the Twelve Meridians easy to pacify. This has been repeatedly tested and verified; let the discerning observe.
Rashes originate from the Stomach. Ancients said: If heat has not entered the Stomach but purgatives are used, heat enters the empty Stomach, causing macules (Ban). If heat has already entered the Stomach and purgatives are not used promptly, heat cannot escape, also causing macules. This refers to Cold Evil transforming into Heat, resulting from erroneous or missed purgation. If epidemic rash occurs without prior diaphoresis or purgation, and heat manifests within a day, I therefore state that Heat Epidemics present with macules and rashes, whereas Cold Damage does not. The later the macules and rashes of Heat Epidemic appear, the heavier the toxicity. If they appear immediately upon illness onset, it is because the Stomach was originally not deficient; accidentally contracting epidemic evil, it cannot enter the Stomach, just as a high and thick wall with tight doors prevents intruders from entering. This is what Yu Yuke called reaching the Membrane Source. If they remain unmanifested after four or five days, it is either due to Stomach deficiency and deep toxin absorption, or excessive diaphoresis and purgation. The Stomach is the Sea of the Twelve Meridians; all Twelve Meridians above and below pay homage to the Stomach. The Stomach can distribute nutrients to the Twelve Meridians, nourishing the hundred bones, penetrating every hair follicle. Once the toxin enters the Stomach, it inevitably distributes to the Twelve Meridians, harming the hundred bones. If its blazing intensity is not suppressed, the hundred bones will suffer roasting; how could it not be critical? Since epidemics are termed toxins, their nature as Fire is evident. The harm caused by Fire is great: Earth scorches when meeting it, Metal melts, Wood burns, and Water dries up if it cannot overcome it. Thus, the *I Ching* states: "Nothing dries the myriad things more than Fire." The ancients called it the thief of Original Qi. From this, we know that Fire is the root of rashes, and rashes are the sprouts of Fire. If you wish for the sprouts to emerge outwardly, how can they flourish without nourishing the root? Diaphoresis on a blazing flame is like wind fanning fire; will the flames not become more intense? The more intense the flames, the more suppressed the sprouts. Deaths from rashes due to diaphoresis are common. Those who survive diaphoresis belong to categories like Measles (Ma Zhen) or Wind Rash (Feng Zhen). Some say rashes are treatable but macules are difficult to treat; this likely refers to epidemic rashes as macules! Why are epidemic rashes difficult to treat? It is simply that people do not know how to apply this method.