《内经》谓夏伤于暑，秋伤于风，必有 疟。 疟，老疟也。以其隔两日一作，缠绵不休，故有是名。前贤具有治
法，然皆峻剂。有非禀受性弱，与居养所移者所宜用也。惟许学士方有用参、 等补剂，而又不曾深论，后学难于推测。
因见近年以来，五十岁以下之人，多是怯弱者，况嗜欲纵恣，十倍于前。以弱质而得深病，最难为药。始悟常山、乌梅、
砒丹等为劫痰之剂，若误用之，轻病为重，重病必死。何者？夫三日一作，阴受病也。作于子、午、卯、酉日，少阴疟
也；作于寅、申、巳、亥日，厥阴疟也；作于辰、戌、丑、未日，太阴疟也。疟得于暑，当以汗解。或凉台水阁，阴木
冷地，他人挥扇，泉水澡浴，汗不得泄，郁而成痰。其初感也，胃气尚强，全不自觉。至于再感，懵然无知，又复恣意
饮食，过分劳动，竭力房事，胃气大伤，其病乃作。深根固蒂，宜其难愈。病者欲速愈，甘辛峻剂，医者欲急利，遽便
将投。殊不知感风、感暑，皆外邪也，当以汗解。所感既深，决非一二升汗可除。亦有胃气少回，已自得汗，不守禁忌，
又复触冒，旧邪未去，新邪又感，展转沉滞，其病愈深。况来求治者，率皆轻试速效。劫病之药，胃气重伤，吾知其难
免于祸矣。由是甘为迟钝，范我驰驱，必先以参、术、陈皮、芍药等补剂，辅以本经之药，惟其取汗。若得汗而体虚，
又须重用补剂以助之，俟汗出通身，下过委中，方是佳兆。仍教以淡饮食，省出外，避风就温，远去帷薄，谨密调养，
无有不安。若感病极深，虽有大汗，所感之邪，必自脏传出至腑，其发也必乱而失期，亦岂是佳兆？故治此病，春夏为
易，秋冬为难，非有他也，以汗之难易为优劣也。或曰∶古方用砒丹、乌梅、常山得效者不为少，子以为不可用乎？予
曰∶腑受病者浅，一日一作。间一日一作者，是胃气尚强，犹可与也。彼三日一作者，病已在脏矣，在脏者难治。以其
外感犹可治也，而可用劫药以求速效乎？
前岁宪佥詹公，禀甚壮、形甚强，色甚苍，年近六十，二月得 疟，召我视之。知其饫于 肥者，告之曰∶须远色
食淡，调理浃月，得大汗乃安。公不悦。一人从旁曰∶此易耳，数日可安。与劫药三五帖病退，旬日后又作，又与又退，
绵延至冬，病犹未除，又来求治。予知其久得药，痰亦少，惟胃气未完，又天寒汗未透。遂以白术粥和丸与二斤，令其
遇饥时且未食，取一二百丸以热汤下，只与白粥调养，尽此药，当大汗而安。已而果然。如此者甚多，但药略有加减，
不必尽述。
《黄帝内经》中说，夏季感受暑邪，秋季感受风邪，必定会患疟疾。这里的“疟”，指的是老疟（久治不愈的疟疾）。因为它每隔两天发作一次，缠绵不断，所以有了这个名称。前代贤人都有治疗的方法，但所用的都是药性猛烈的方剂。这些方剂并不适合那些先天禀赋虚弱，或因居住环境和调养不当导致体质改变的人使用。只有许学士的方子中使用了人参等补益药物，但又没有深入论述其原理，后学者难以推测其中的奥妙。
我观察到近年来，五十岁以下的人，大多体质怯弱，况且纵情声色欲望的程度是过去的十倍。以虚弱的体质患上深重的疾病，最难用药。这才领悟到常山、乌梅、砒丹等属于劫夺痰涎的猛药，如果误用，轻病会变成重病，重病则必然致死。为什么呢？因为每隔三天发作一次的，是阴经受病。在子日、午日、卯日、酉日发作的，是少阴疟；在寅日、申日、巳日、亥日发作的，是厥阴疟；在辰日、戌日、丑日、未日发作的，是太阴疟。疟疾由暑邪引起，应当通过发汗来解除。如果在凉台水阁、阴冷的树木下或冷地上，或者在别人扇扇子时、泉水中洗澡，导致汗液无法排泄，郁结而成痰。初次感受邪气时，胃气还很强盛，完全自己感觉不到。等到再次感受邪气，懵懂无知，又放纵饮食，过度劳累，竭力行房事，导致胃气大伤，疾病才发作。病根深固，难怪难以治愈。患者想要快速痊愈，甘愿服用辛热峻猛的药剂；医生想要急于求成，便立刻投药。殊不知感受风邪、暑邪，都是外邪，应当通过发汗来解除。既然感受已深，决不是喝一两升汗就能除去的。也有胃气稍微恢复，已经自然出汗，但不遵守禁忌，又再次受风寒侵袭，旧邪未去，新邪又感，辗转沉滞，病情越来越深。何况来求治的人，大都希望尝试速效。使用劫病的药物，会使胃气受到严重伤害，我知道他们难免遭受祸害。因此，我甘愿采取看似迟钝的方法，规范我的治疗节奏，必须先用人参、白术、陈皮、芍药等补益药剂，辅以本经的药物，目的是取汗。如果出汗后身体仍虚弱，必须重用补益药剂来辅助，等到全身出汗，汗液流至委中穴以下，这才是好兆头。仍然教导患者饮食清淡，减少外出，避风保暖，远离帷帐帘幕，谨慎严密地调养，没有不安稳的。如果感受的病邪极深，即使出大汗，所感的邪气，也必然从脏传送到腑，发作时一定混乱且失去规律，这难道是佳兆吗？所以治疗这种病，春夏容易，秋冬困难，没有其他原因，只是因为发汗难易程度的不同。有人问：古方中使用砒丹、乌梅、常山取得效果的不少，你认为不可用吗？我说：腑受病者较浅，一天发作一次。隔一天发作一次的，说明胃气尚强，还可以治疗。那些三天发作一次的，病已经在脏了，在脏的病难治。虽然外感之邪尚可治疗，但可以用劫药来追求速效吗？
去年宪佥詹公，禀赋很壮实，形体很强健，面色很苍老，年龄接近六十岁，二月得了疟疾，召我去诊治。知道他平时饱食肥甘厚味，告诉他说：必须远绝色欲，饮食清淡，调理一个月，出大汗后才能安宁。詹公不高兴。旁边有一人说：这很容易，几天就可以安宁。给予劫药三五帖，病退去，十天后又发作，再给又退去，绵延到冬天，病仍未除，又来求治。我知道他长期服药，痰湿也少了，只是胃气尚未恢复，加上天气寒冷，汗液未能透发。于是用白术粥和丸与他两斤，让他感到饥饿但未进食时，取一二百丸用热汤送下，只给白粥调养，吃完这些药，应当出大汗而痊愈。后来果然如此。像这样的情况很多，只是药物略有加减，不必全部叙述。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states that if one is injured by summerheat in summer and by wind in autumn, malaria will inevitably occur. Here, "malaria" refers to chronic malaria (long-standing, refractory malaria). It is named so because it occurs every other day and lingers without ceasing. Former sages had treatment methods, but they all used harsh medicines. These are not suitable for those with weak innate constitution or whose physique has been altered by living conditions and care. Only the prescriptions of Academician Xu used tonifying agents such as Ginseng Radix et Rhizoma (Renshen, 人参), yet he did not discuss them in depth, making it difficult for later learners to infer their principles.
I have observed that in recent years, people under fifty are mostly frail. Moreover, their indulgence in desires is ten times greater than before. Treating deep diseases in a weak constitution is extremely difficult. I then realized that medicines like Heterophylly Stemroot (Changshan, 常山), Dark Plum (Wumei, 乌梅), and Arsenic Pills (Pidan, 砒丹) are agents that forcibly expel phlegm. If misused, mild disease becomes severe, and severe disease leads to death. Why? Because malaria occurring every three days indicates illness in the Yin channels. Malaria occurring on Zi, Wu, Mao, or You days is Shaoyin malaria; occurring on Yin, Shen, Si, or Hai days is Jueyin malaria; occurring on Chen, Xu, Chou, or Wei days is Taiyin malaria. Malaria caused by summerheat should be resolved through sweating. However, staying in cool pavilions, water towers, under shady trees, or on cold ground, fanning oneself while bathing in spring water, prevents sweat from being excreted, leading to its stagnation and transformation into phlegm. Initially, when the pathogen first invades, the Stomach Qi is still strong, and the patient feels nothing. Upon secondary invasion, the patient remains ignorant, continues to overeat, exert themselves excessively, and engage in sexual activity, severely damaging Stomach Qi, which triggers the disease. The root is deep and the foundation solid, hence it is hard to cure. Patients desire quick recovery and willingly take harsh, pungent-warm medicines; doctors desire quick results and hastily administer them. They do not realize that wind and summerheat are external pathogens that must be resolved through sweating. Since the invasion is deep, it cannot be cleared by merely inducing a small amount of sweat. Even if Stomach Qi recovers slightly and spontaneous sweating occurs, failing to observe taboos and encountering new pathogens again causes old pathogens to remain and new ones to invade, leading to lingering stagnation and deeper disease. Furthermore, patients seeking treatment usually hope for rapid effects. Using pathogen-expelling drugs severely damages Stomach Qi; I know they will inevitably suffer disaster. Therefore, I am willing to adopt a seemingly slow approach, regulating my treatment pace. I must first use tonifying agents such as Ginseng Radix et Rhizoma (Renshen, 人参), Atractylodes Macrocephala Rhizome (Baizhu, 白术), Tangerine Peel (Chenpi, 陈皮), and White Peony Root (Shaoyao, 芍药), assisted by herbs from the classic texts, with the goal of inducing sweating. If the body remains weak after sweating, heavy tonification is required to assist. Only when sweat flows through the entire body and reaches below the Weizhong acupoint (BL40, 委中) is this considered a good omen. I instruct patients to eat bland food, reduce going out, avoid wind and seek warmth, stay away from curtains, and maintain careful nursing. There will be no instability. If the pathogenic factor is extremely deep, even with profuse sweating, the invaded pathogen must transmit from the Zang organs to the Fu organs. Its manifestation will be chaotic and irregular, which is certainly not a good omen. Thus, treating this disease is easier in spring and summer and more difficult in autumn and winter, for no other reason than the ease or difficulty of inducing sweating. Someone asked: Ancient formulas using Arsenic Pills, Dark Plum, and Heterophylly Stemroot achieved success in many cases; do you think they should not be used? I said: When the Fu organs are affected, the disease is shallow, occurring daily. When it occurs every other day, Stomach Qi is still strong, and treatment is possible. Those occurring every three days indicate the disease has reached the Zang organs; diseases in the Zang organs are difficult to treat. Although external pathogens can be treated, can one use harsh expelling drugs to pursue quick results?
Last year, Vice Censor-in-Chief Zhan, who was robust in constitution, strong in physique, and dark-complexioned, nearly sixty years old, contracted malaria in February and summoned me. Knowing he was accustomed to rich, fatty foods, I told him: He must abstain from sexual activity, eat blandly, and regulate his diet for a month until profuse sweating brings relief. He was displeased. Someone nearby said: This is easy; he will recover in a few days. After taking three to five doses of expelling drugs, the fever subsided, but returned ten days later. Again, it subsided after medication, lingering until winter, yet the disease remained. He came to seek treatment again. I knew that due to long-term medication, his phlegm had decreased, but his Stomach Qi was not yet restored, and due to cold weather, sweat had not penetrated. So, I prepared pills mixed with White Atractylodes Rhizome porridge, giving him two jin. He was instructed to take 100-200 pills with hot water when hungry but before eating, and to nourish himself only with white rice porridge. Upon finishing this medicine, he should sweat profusely and recover. Indeed, it happened as predicted. There were many such cases, with slight variations in herbs, which need not be fully detailed.