北方医者治温病，恒用吴又可达原饮，此大谬也。吴氏谓崇祯辛巳，疫气流行，山东、浙江南北两道感
者尤多，遂着《瘟疫论》一书。首载达原饮，为治瘟疫初得之方，原非治温病之方也。疫者，天地戾气，其
中含有毒菌，遍境传染若役使然，故名为疫。因疫多病热，故名为瘟疫（病寒者名为寒疫），瘟即温也。是
以方中以逐不正之气为主。至于温病，乃感时序之温气，或素感外寒伏于膜原，久而化热，乘时发动，其中原
无毒菌，不相传染。治之者惟务清解其热，病即可愈。若于此鉴别未精，本系温病而误投以达原饮，其方中
槟榔开破之力既能引温气内陷，而浓朴、草果之辛温开散大能耗阴助热，尤非病温者所宜（病温者多阴虚
尤忌耗阴之药），虽有知母、芍药、黄芩各一钱，其凉力甚轻，是以用此方治温病
者，未有见其能愈者也。且不惟不能愈，更有于初病时服之即陡然变成危险之证者，此非愚之凭空拟议，诚
有所见而云然也。
愚初习医时，曾见一媪，年过六旬，因伤心过度，积有劳疾，于仲春得温病。医者投以达原饮，将方中
草果改用一钱，谓得汗则愈。乃服后汗未出而病似加重，医者遂将草果加倍，谓服后必然得汗。果服后头面
汗出如洗，喘息大作，须臾即脱。或疑此证之偾事，当在服达原饮将草果加重，若按其原方分量，草果
只用五分，即连服数剂亦应不至汗脱也。答曰∶草果性甚猛烈，即五分亦不为少。愚尝治脾虚泄泻服药不效，
因思四神丸治五更泻甚效，中有肉果，本草谓其能健脾涩肠，遂用健补脾胃之药煎汤送服肉果末五分。须
臾觉心中不稳，六脉皆无，迟半点钟其脉始见。恍悟病患身体虚弱，不胜肉果辛散之力也。草果与肉果性
原相近，而其辛散之力更烈于肉果，虽方中止用五分，而与槟榔、浓朴并用，其猛烈之力固非小矣。由
斯观之，达原饮可轻用哉！
北方医生治疗温病，常常使用吴又可的达原饮，这是极大的错误。吴氏说在崇祯辛巳年，疫气流行，山东、浙江南北两道感染的人尤其多，于是撰写了《瘟疫论》一书。书中首先记载了达原饮，作为治疗瘟疫初起的方法，原本就不是治疗温病的方剂。所谓“疫”，是天地间的戾气，其中含有毒菌，在环境中到处传染，像役使一样，所以称为“疫”。因为疫病多表现为热证，所以称为“瘟疫”（患寒证的称为“寒疫”），“瘟”就是“温”的意思。因此，该方以驱逐不正之气为主。至于温病，则是感受了时序的温气，或者素来感受外寒伏藏在膜原，时间久了化热，趁着时令发作，其中并没有毒菌，也不互相传染。治疗时只需致力于清热解表，病就可以痊愈。如果对此鉴别不精细，本来是温病却误用了达原饮，方中槟榔的开破之力既能引导温气内陷，而厚朴、草果的辛温开散之性大能耗伤阴液并助长热势，尤其不适合温病患者（温病患者多阴虚，特别忌讳耗伤阴液的药物），虽然方中有知母、芍药、黄芩各一钱，但其凉润之力很轻，因此用这个方子治疗温病的人，没有见到能治愈的。而且不仅不能治愈，更有在初病时服用后立刻突然变成危险证候的，这并不是我凭空臆测，确实是有所见才这样说的。
我刚开始学医时，曾见过一位老妇人，年龄超过六十岁，因为伤心过度，积劳成疾，在仲春时节得了温病。医生给她用了达原饮，将方中的草果改为一钱，说出汗就能痊愈。然而服药后汗未出，病情似乎加重，医生于是将草果加倍，说服用后必然出汗。果然服药后头面出汗如洗，喘息大作，片刻之后便出现脱证（阳气暴脱）。有人怀疑这个病例失败的原因，在于服用达原饮时将草果加重，如果按照原方分量，草果只用五分，即使连服几剂也不至于导致汗出亡阳。回答说：草果药性非常猛烈，即使是五分也不算少。我曾经治疗脾虚泄泻患者服药无效，想到四神丸治疗五更泻很有效，其中含有肉豆蔻，本草说它能健脾涩肠，于是用健补脾胃的药物煎汤送服肉豆蔻末五分。片刻后觉得心中不安，六脉皆无，过了半个小时脉搏才恢复。猛然醒悟是因为病患身体虚弱，承受不了肉豆蔻辛散的力量。草果与肉豆蔻的药性原本相近，但草果的辛散之力比肉豆蔻更猛烈，虽然方中只用了五分，但与槟榔、厚朴并用，其猛烈的力量确实不小。由此看来，达原饮怎么可以轻易使用呢！
Physicians in the North often use Da Yuan Yin (Reach the Origin Decoction) to treat Wen Bing (Warm Disease), which is a major error. Wu Shi stated that during the Xin Si year of the Chongzhen reign, epidemic qi spread widely, with particularly many infections in Shandong and Zhejiang provinces along both north and south routes; thus, he wrote the book *Wen Yi Lun* (Treatise on Plague). The first prescription recorded was Da Yuan Yin, intended as a formula for the initial stage of plague, not originally designed for treating Wen Bing. "Yi" (Plague/Epidemic) refers to the malevolent qi of heaven and earth, containing toxic bacteria, spreading throughout the environment like servitude, hence named "Yi". Since plagues mostly present with heat syndromes, they are called "Wen Yi" (Warm Plague; those presenting with cold syndromes are called "Han Yi"); "Wen" means "Warm". Therefore, this formula focuses on expelling abnormal qi. In contrast, Wen Bing arises from contracting the warm qi of the season, or from external cold previously contracted lying latent in the Mo Yuan (Membrane Source), transforming into heat over time and erupting when the season arrives; it contains no toxic bacteria and is not contagious. Treatment should solely aim at clearing and resolving heat, after which the disease can be cured. If differentiation is not precise, and a patient suffering from Wen Bing is mistakenly given Da Yuan Yin, the breaking-down power of Bin Lang (Areca Seed) in the formula can guide warm qi inward, while the acrid-warm dispersing nature of Hou Po (Magnolia Bark) and Cao Guo (Tsaoko Fruit) severely consumes yin fluids and assists heat, which is especially unsuitable for patients with Wen Bing (patients with Wen Bing often have yin deficiency and particularly must avoid herbs that consume yin). Although the formula contains Zhi Mu (Anemarrhena Rhizome), Bai Shao (White Peony Root), and Huang Qin (Scutellaria Root), each at one qian, their cooling power is very weak. Consequently, there has never been a case where using this formula cured Wen Bing. Moreover, not only does it fail to cure, but taking it at the onset of illness can suddenly transform the condition into a critical state. This is not my baseless speculation, but based on actual observations.
When I first studied medicine, I once observed an elderly woman over sixty years old who, due to excessive grief, had accumulated chronic fatigue disease. In mid-spring, she contracted Wen Bing. The physician prescribed Da Yuan Yin, modifying the dosage of Cao Guo to one qian, stating that sweating would lead to recovery. However, after ingestion, no sweat appeared, and symptoms seemed to worsen. The physician then doubled the dose of Cao Guo, claiming sweating was inevitable. Indeed, after taking the modified dose, profuse sweating occurred on the head and face, severe panting ensued, and within moments, the patient suffered from collapse (sudden loss of yang qi). Some suspected the failure of this case lay in increasing the dose of Cao Guo in Da Yuan Yin; if the original dosage of five fen were used, even several doses should not have led to sweating-induced collapse. I replied: Cao Guo has a very potent nature; even five fen is not a small amount. I once treated a patient with spleen-deficiency diarrhea unresponsive to medication. Recalling that Si Shen Wan (Four Spirits Pill) is effective for dawn diarrhea and contains Rou Dou Kou (Nutmeg), which materia medica states strengthens the spleen and binds the intestines, I administered half a qian of powdered Rou Dou Kou with decoctions of spleen-strengthening herbs. Shortly after, the patient felt inner instability, and all six pulses disappeared, reappearing only after half an hour. I suddenly realized that the patient's weak constitution could not withstand the acrid-dispersing power of Rou Dou Kou. Cao Guo shares similar properties with Rou Dou Kou, but its acrid-dispersing force is even more intense. Although only five fen was used in the formula, combined with Bin Lang and Hou Po, its potent strength is certainly significant. From this, we can see how dangerous it is to use Da Yuan Yin lightly!