伤寒之用表药。固其常也。而余独鳃鳃慎之。何欤。盖药性有刚柔。人质有
浓薄。喜用之则昌。不喜用之则危。匪细故也。即以麻黄论。味轻而浮。长于
驱寒者也。而失之太热。羌活独活。利关节为最胜也。而失之过燥。如太阴
之苍术。阳明之白芷。厥阴之川芎吴茱萸。少阴之细辛。太阳之 本。气味
辛烈。亦复如是。故仲景立麻黄汤。润以杏仁。和以甘草。果足敌麻黄桂枝
之辛热乎。易老九味羌活汤。汇诸燥味。以黄芩生地监之。寡不胜众。又岂
制方之善者乎。余独不然。漫立一方以平易易之。紫苏味之辛温者也。足
以去寒。防风荆芥。味之辛散者也。足以去风。柴胡性升。能除表热。葛根性
润。长于解肌。广皮辛苦。能散能降。甘桔味甘。合以生姜。辛甘发散。如是而
寒有不除。风有不解者乎。如是而有耗其津液。损其真阴。亡其元阳者乎。
若果脉紧无汗。则加麻黄羌活。脉细湿胜。则用苍术独活。如吴茱细辛白
芷本之属。倘或对症。暂投则可。否则感冒轻者。禀质薄者。及病后。劳后。
产后。酒色后。即恶寒发热。岂可一概不审。而漫执古方以恣浪投者邪。即
予所定之方。亦未必中肯綮也。
紫苏饮
紫苏（一钱五分） 防风 荆芥 柴胡 葛根 广皮 桔梗（各一钱） 甘草（炙三分） 山楂（一钱五分）
加生姜三片水煎。头痛。加川芎五分。夹食。加浓朴一钱姜制。枳壳一钱麸炒。如咳嗽。去柴胡。加前胡一钱。
按此方虽平易。虚者犹不能当。慎勿泛用多用。得汗即止。
治疗伤寒使用解表药，固然是常规做法。但我独自对此格外谨慎小心。为什么呢？因为药物的性质有刚烈与柔和之分，人的体质有浓盛与薄弱之别。如果适合用药则病情好转，不适合用药则会有危险，这并非小事。就拿麻黄来说，味道轻清而浮散，擅长驱散寒邪，但缺点是过于温热。羌活和独活，在疏通关节方面最为出色，但缺点是过于燥烈。比如太阴经用的苍术、阳明经用的白芷、厥阴经用的川芎和吴茱萸、少阴经用的细辛、太阳经用的本，这些药物气味都辛烈，情况也是如此。所以张仲景创立麻黄汤，用杏仁的滋润来调和，用甘草的和缓来配合，果真足以抵挡麻黄、桂枝的辛热之性吗？易老（王好古）的九味羌活汤，汇聚了各种燥烈的药味，再用黄芩、生地来监制它们，但寡不敌众，这难道是制方的高明之法吗？我却不这样认为。我随意设立一方来平和地替代它：紫苏的味道是辛温的，足以去除寒邪；防风、荆芥的味道是辛散的，足以祛除风邪；柴胡的性质升发，能解除体表的发热；葛根的性质滋润，擅长解除肌肉层面的邪气；广皮（陈皮）辛苦，既能发散又能降逆；桔梗和甘草味道甘甜，加上生姜，辛甘合化可以发散。像这样的话，难道还会有寒邪不能除去、风邪不能解散的情况吗？像这样的话，难道还会耗伤津液、损伤真阴、亡失元阳吗？
如果确实脉象紧且无汗，就加入麻黄、羌活；如果脉细且湿气重，就用苍术、独活。至于吴茱萸、细辛、白芷、本这类药物，倘若对症，暂时投用是可以的。否则，对于感冒较轻、禀赋体质薄弱的人，以及病后、劳累后、产后、酒色之后，即使出现恶寒发热的症状，怎么可以不仔细审察，就盲目执着于古方肆意投药呢？即便是我所制定的这个方子，也未必能完全切中要害。
紫苏饮
紫苏（一钱五分） 防风 荆芥 柴胡 葛根 广皮 桔梗（各一钱） 甘草（炙三分） 山楂（一钱五分）
加生姜三片，水煎服。头痛，加川芎五分；夹食（兼有食积），加姜制的浓朴一钱、麸炒的枳壳一钱。如果有咳嗽，去掉柴胡，加前胡一钱。
按语：此方虽然平和平易，但对于虚证患者仍然难以承受，千万不要广泛使用或过量使用。得到汗出就要停止服用。
The use of exterior-releasing medicines for treating Shanghan (Cold Damage) is indeed a standard practice. However, I alone am particularly cautious and apprehensive about it. Why? Because drug properties vary between rigid (acrid/warm) and soft (mild/cool), and human constitutions differ in robustness and frailty. If the medicine suits the patient, health prospers; if not, danger ensues. This is no trivial matter. Taking Ephedrae Herba (Mahuang, 麻黄) as an example: its flavor is light and floating, excelling at expelling cold, but it errs on being too hot. Notopterygii Rhizoma et Radix (Qianghuo, 羌活) and Angelicae Pubescentis Radix (Duhuo, 独活) are superior for benefiting joints, but they err on being overly drying. For instance, Atractylodis Rhizoma (Cangzhu, 苍术) for Taiyin disease, Angelicae Dahuricae Radix (Baizhi, 白芷) for Yangming disease, Ligustici Chuanxiong Rhizoma (Chuanxiong, 川芎) and Evodiae Fructus (Wuzhuyu, 吴茱萸) for Jueyin disease, Asari Radix et Rhizoma (Xixin, 细辛) for Shaoyin disease, and Libanodendroni Resina (Ben, 本) for Taiyang disease—all possess pungent and fierce aromas, exhibiting similar characteristics. Therefore, Zhang Zhongjing formulated Mahuang Tang (Ephedra Decoction), using Semen Armeniacae Amarum (Xingren, 杏仁) for its moistening property and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) to harmonize. Is this truly sufficient to counteract the pungent-heat of Mahuang and Cinnamomi Ramulus (Guizhi, 桂枝)? Wang Haogu’s Jiwei Qianghuo Tang (Nine-Ingredient Notopterygium Decoction) aggregates various drying flavors, monitored by Scutellariae Radix (Huangqin, 黄芩) and Rehmanniae Radix Preparata (Shengdi, 生地). Yet, few cannot overcome many; is this not a flawed method of formulation? I disagree. I casually established a formula to replace it with mildness: Perillae Folium (Zisu, 紫苏) has a pungent-warm nature, sufficient to dispel cold; Saposhnikoviae Radix (Fangfeng, 防风) and Schizonepetae Spica (Jingjie, 荆芥) have pungent-dispersing natures, sufficient to expel wind; Bupleuri Radix (Chaihu, 柴胡) has an ascending nature, capable of relieving exterior heat; Puerariae Radix (Gegen, 葛根) has a moistening nature, excelling at resolving muscle-layer pathogens; Citri Reticulatae Pericarpium (Guangpi, 广皮) is acrid-bitter, capable of both dispersing and descending; Platycodonis Radix (Jiegeng, 桔梗) and Gancao combined with Zingiberis Rhizoma Recens (Shengjiang, 生姜) create a pungent-sweet combination that disperses. In such a manner, how could cold fail to be removed or wind fail to be resolved? How could there be depletion of body fluids, damage to true Yin, or loss of primal Yang?
If the pulse is tight and there is no sweat, add Mahuang and Qianghuo. If the pulse is fine and dampness prevails, use Cangzhu and Duhuo. As for Evodiae Fructus, Xixin, Baizhi, and Ben, if they match the syndrome, temporary administration is acceptable. Otherwise, for mild colds, those with frail constitutions, and after illness, exertion, postpartum, or sexual indulgence/alcohol consumption, even if chills and fever occur, how can one fail to examine carefully and blindly adhere to ancient formulas for reckless administration? Even my prescribed formula may not hit the mark precisely.
Zisu Yin (Perilla Decoction)
Perillae Folium (1.5 qian) Saposhnikoviae Radix Schizonepetae Spica Bupleuri Radix Puerariae Radix Citri Reticulatae Pericarpium Platycodonis Radix (each 1 qian) Glycyrrhizae Radix et Rhizoma (roasted, 0.3 qian) Crataegi Fructus (1.5 qian)
Decoct with three slices of fresh ginger. For headache, add Ligustici Chuanxiong Rhizoma (0.5 qian). For food stagnation, add prepared Magnoliae Officinalis Cortex (1 qian) and fried Aurantii Fructus Immaturus (1 qian). For cough, remove Bupleuri Radix and add Peucedani Radix (1 qian).
Note: Although this formula is mild and gentle, it is still too strong for deficient patients. Do not use it indiscriminately or excessively. Stop taking it once sweating occurs.