卫生方云。麻黄生于中牟。有麻黄之地。冬雪不积。盖麻黄能泄外阳故也。今南方无霜雪。皆
如麻黄之地。阳气恒泄。即此可知。人居其间。不劳麻黄而自汗。有病则不宜轻发汗。轻用麻黄。
此理甚明。前辈诗云。四时恒是夏。一雨便成秋。读此一联。不惟知南方天气。亦可触类而知。
夫人之病也。假如病者多热。才经一汗。便翻然为冷。是岂宜轻发汗耶。如五积散。通关散。金沸草散。九
宝饮。小续命汤。十神汤。香苏散。俱有麻黄。虽有主对。亦不可服。若麻黄汤。青龙汤。南方
尤不可遽用也。今人例以麻黄为发散药。殊不知其力只能驱我
之内阳。以劫外寒也。古今方书用肺经咳嗽。以肺之性恶寒。肺为娇脏。易于感寒。乃宜用之。
仲景治足太阳伤寒。以太阳在表。非汗不解。及治少阴经伤寒。发热脉沉。盖少阴当无热恶
寒反发热者。邪在表也。故以温剂佐之。发中有补。皆所当用也。除此三经。方书已自少用。况
南方不寒之地。瘴气交重。瘴病岂尽因感寒耶。不因感寒。不用麻黄。又何不可。南史记范云欲赴
梁武帝九锡之命。忽尔伤寒。召医徐文伯治之。恐不得与庆事。实告之曰。欲即愈。当先期取汗。
但不免妄泄元阳。恐二年后不复起矣。云曰朝闻夕可。况二年乎。文伯烧地布席。置云于上。得汗
而解。云大喜。文伯曰。不足喜也。后二年果应。夫发汗先期。尚促寿限。况不当汗而汗乎。
又尝见有染瘴者。上热下寒。腰足寒痛。自谓五积散症也。遂倍加麻黄。多衣覆汗。竟成重症。
虽服真武汤。亦莫能救。并赘于此。为妄用药者之戒。大凡瘴病误用麻黄。服后哑者。七日内死。
或筋惕肉 者。十四日内死。或目赤上气喘促者。十四日内死。若汗出不止。脉细如无悸动。寒
战发哕者。实时死。余常目击。可不慎哉。
The *Weisheng Fang* (Prescriptions for Health Preservation) states: Ephedrae Herba (Mahuang, 麻黄) grows in Zhongmu. In places where Ephedra grows, winter snow does not accumulate. This is because Ephedra can disperse the external Yang Qi (vital energy on the body surface). Currently, the southern regions have no frost or snow, resembling areas where Ephedra grows; thus, Yang Qi is constantly dispersed. From this, it can be inferred that people living there sweat naturally without using Ephedra. When illness occurs, one should not lightly employ diaphoresis (sweating therapy). The use of Ephedra must be approached with caution, as the reasoning is clear. An ancient poem states: "Four seasons are always like summer; a single rain turns it to autumn." Reading this couplet allows one not only to understand the southern climate but also to apply this logic to other matters.
Regarding human diseases, if a patient has excessive internal heat, a single episode of sweating may suddenly cause the condition to shift to cold. How could light diaphoresis be appropriate here? Formulas such as Wuji San (Five Accumulations Powder), Tongguan San (Passage Through Obstruction Powder), Jinfeicao San (Boiling Grass Powder), Jiubao Yin (Nine Treasures Drink), Xiao Xuming Tang (Minor Continuation of Life Decoction), Shishen Tang (Ten Spirits Decoction), and Xiangsu San (Aromatic Su Decoction) all contain Ephedra. Although they have specific indications, they should not be taken in the south. Furthermore, Mahuang Tang (Ephedra Decoction) and Qinglong Tang (Azure Dragon Decoction) should especially not be used hastily in the south. People today habitually regard Ephedra as a dispersing herb, unaware that its power merely drives away internal Yang Qi to forcibly overcome external cold. In ancient and modern formularies, Ephedra is indicated for lung meridian coughs because the Lung organ dislikes cold and is delicate, making it susceptible to cold pathogens.
Zhang Zhongjing treated Taiyang (Greater Yang) exogenous cold by inducing sweating, as the Taiyang channel is at the exterior and requires sweating to resolve. He also treated Shaoyin (Lesser Yin) exogenous cold presenting with fever and a deep pulse. Typically, Shaoyin disease involves aversion to cold without fever; if fever is present, it indicates the pathogen is still at the exterior. Therefore, warm tonifying agents are used as assistants, achieving sweating while providing tonification; these are appropriate uses. Apart from these three channels, formularies rarely use Ephedra. Moreover, in the non-cold southern regions where miasma (pathogenic environmental factors) is heavy, is miasmatic disease entirely caused by cold contraction? If not caused by cold, why is it inappropriate to avoid Ephedra?
The *History of the Southern Dynasties* records that Fan Yun, upon accepting the Nine Bestowals from Emperor Wu of Liang, suddenly contracted exogenous cold. He summoned physician Xu Wenbo for treatment, fearing he would miss the celebration. Xu Wenbo truthfully stated: "To recover immediately, sweating must be induced beforehand, but this will recklessly deplete Yuan Yang (Primordial Yang), and you likely will not survive two years." Fan Yun replied: "If I hear the Way in the morning, I am content to die in the evening; what more about two years?" Xu Wenbo heated the floor, laid mats, and placed Fan Yun upon them. After sweating, the illness resolved. Fan Yun was greatly delighted. Xu Wenbo said: "There is no need to rejoice; indeed, two years later, it came to pass." Since premature sweating shortens life expectancy, how much more so is it harmful when sweating is contraindicated?
I have also seen cases of those infected with miasma presenting with upper heat and lower cold, with cold pain in the waist and feet. They mistakenly identified this as a Wuji San pattern and doubled the dose of Ephedra, covering themselves heavily to induce sweating, which ultimately resulted in severe illness. Even the administration of Zhenwu Tang (True Warrior Decoction) could not save them. These cases are recorded here as a warning against reckless medication. Generally, if miasmatic patients misuse Ephedra and develop aphonia (loss of voice), death occurs within seven days. If muscle twitching (fasciculation) occurs, death occurs within fourteen days. If red eyes, upward gasping, and rapid breathing occur, death occurs within fourteen days. If sweating continues unceasingly, the pulse becomes minute and faint as if absent, accompanied by chills and hiccups, death occurs immediately. I have witnessed these situations personally; how can one not be cautious?