夫汗之生源有二∶一出于充肤、热肉之血，血之液化而为汗，此表汗也；一出于阳明胃腑，乃水液之
汗也。是以表汗止可微取，恐血液伤而阳气脱；若水液之汗，不妨如水淋漓。麻黄汤发表之剂也，麻黄空
细如毛，能开发皮毛间之闭邪。植麻黄之地，冬不积雪，能通阳气于至阴之下。又肺主皮毛，故配杏子以
利肺气，盖内窍通而外窍始通也。如配石膏，乃直从阳明而发水液之汗，又非发表之剂矣。（配一味即大相径庭，
立方加减，可轻忽欤！）如小便不利者，用麻黄、杏子配八正散，内加二味，其应如响，盖外窍通而内窍通，上窍
通而下窍即利矣。予在苕溪，治一水肿者，腹大，肤肿，久服八正散、琥珀散、五子、五皮之类，小便仍
淋漓，痛苦万状。予曰∶此虽虚证，然水不行则肿不消，肿不消则正气焉能平复？时值夏月，予不敢用麻
黄，恐阳脱而汗漏不止，以苏叶、防风、杏子三味，各等分，令煎汤温服，覆取微汗，而水即利矣。次日
至病者之室，床之上下，若倾数桶水者，被褥帏簿，无不湿透。病者云∶昨服药后，不待取汗，而小水如
注，不及至溺桶，而坐于床上行之，是以床下如此
也。至天明，不意小水复来，不及下床，是以被褥又如是也。今腹满、肿胀俱消，痛楚尽解，深感神功之救
我。予曰∶未也。此急则治其标耳！子之病因火土伤败，以致水泛，乃久虚之证也。火即人之元气，必待
脾气、元气复，而后可保其万全。予即解维，写一六君子方去甘草，加苍术、浓朴、炮姜、熟附子，每
日令浓煎温服；即以此方令合丸药一料，每日巳未时服之，即止其汤药。半载后，病者之兄，备土物来谢
曰∶吾弟已全愈矣。予曰∶如此之证，水虽行而正气不复，后仍肿胀而死者比比，此命不应绝，非予之功
也。虽然邪之所凑，其正必虚，若初肿之时，行去其水，正气易于平复，医者不知发汗行水之法，惟以疏
利之药利之，肿或减而无尾闾之泄，犹以邻国为壑耳！如久服疏利之药，则正气日消，水留日久，则火
土渐灭，然后以此法行之，无济于事矣！
汗液的生成来源有两个：一是来源于充盈皮肤、温热肌肉的血液，血液液化后成为汗，这属于表层的汗；二是来源于阳明胃腑，这是水液代谢产生的汗。因此，针对表层的汗只能微微取之，恐怕会损伤血液而导致阳气脱失；如果是水液代谢产生的汗，不妨让它像水流一样淋漓而出。麻黄汤是发表（发散表邪）的方剂，麻黄的茎秆中空且细小如毛发，能够开发皮毛之间闭塞的邪气。种植麻黄的地方，冬天不会积雪，说明它能通达至阴之下的阳气。另外，肺主司皮毛，所以配伍杏仁来宣利肺气，因为内部窍道通畅了，外部窍道才能通畅。如果配伍石膏，就是直接从阳明经发散水液之汗，这就不是发表（发散表邪）的方剂了。（仅仅增加一味药就大相径庭，处方时的加减变化，怎能轻视呢！）如果小便不利，使用麻黄、杏仁配伍八正散，在内部加入这两味药，疗效迅速显著，因为外窍通畅了内窍也就通畅，上窍通畅了下窍自然通利。我在苕溪时，治疗一位水肿患者，腹部胀大，皮肤浮肿，长期服用八正散、琥珀散、五子衍宗丸、五皮饮之类的药物，小便仍然淋漓不尽，痛苦万分。我说：“这虽然是虚证，但是水湿不行则肿胀不消，肿胀不消则正气怎么能平复恢复？”当时正值夏季，我不敢用麻黄，恐怕导致阳气脱失而汗出不止，于是用苏叶、防风、杏仁三味药，各等分，让他煎汤温服，覆盖衣被取微汗，结果水湿即通过小便排出。第二天到病人房间，床铺上下，好像倾倒了几桶水，被褥帷帐没有不透湿的。病人说：“昨天服药后，还没等到刻意发汗，小便就像注水一样，来不及走到便桶，就坐在床上排尿，所以床下如此。”到了天亮，没想到小便又来，来不及下床，所以被褥又湿了。现在腹部胀满、全身肿胀都消除了，疼痛痛苦全部解除，深深感激神效救了我。我说：“还不行。这只是急则治其标罢了！你的病因是火（心/命门之火）和土（脾）受损败坏，导致水湿泛滥，这是久病虚损的证候。火就是人的元气，必须等待脾气、元气恢复，然后才能确保万无一失。”我随即启程，开了一副六君子汤去掉甘草，加入苍术、厚朴、炮姜、熟附子，每天让他浓煎温服；同时用这个方子制作一料丸药，每天巳时和未时服用，以此停止汤药。半年后，病人的哥哥准备了当地特产来感谢我说：“我弟弟已经完全痊愈了。”我说：“这样的证候，虽然水湿排出了但正气没有恢复，后来仍然因肿胀而死的人比比皆是，这是我弟弟命不该绝，并不是我的功劳。虽然如此，邪气聚集的地方，正气必然虚弱，如果在初起肿胀时，采用发汗行水的方法，正气容易平复恢复，医生不知道发汗行水的方法，只用疏利（利尿通便）的药物来利水，肿胀或许减轻但没有从尾闾（肾与膀胱排泄关口）彻底泄出，这就像把祸害推给邻国一样！（意指治标不治本，隐患仍在）。如果长期服用疏利的药物，那么正气日渐消耗，水湿停留日久，火土之气逐渐熄灭，然后再用这种方法治疗，就没有什么帮助了！”
The source of sweat generation has two aspects: one originates from the blood that fills the skin and warms the muscles; when this blood transforms into liquid, it becomes sweat, which is referred to as superficial sweat (Biao Han); the other originates from the Stomach Fu organ of the Yangming channel, which is sweat derived from water metabolism. Therefore, superficial sweat should only be induced slightly, for fear of damaging the blood and causing the escape of Yang Qi; whereas sweat derived from water metabolism may be allowed to flow profusely like water. Mahuang Tang is a formula for releasing the exterior (Fa Biao). The stem of Ephedrae Herba (Mahuang) is hollow and fine as hair, capable of opening the closure of pathogenic factors between the skin and hair follicles. Where Ephedrae Herba grows, snow does not accumulate in winter, indicating its ability to unblock Yang Qi beneath the extreme Yin. Furthermore, the Lung governs the skin and hair follicles; thus, Semen Armeniacae Amarum (Xingren) is combined to benefit Lung Qi, because once the internal orifices are unblocked, the external orifices can also be unblocked. If Gypsum Fibrosum (Shigao) is combined, it directly releases water-derivative sweat from the Yangming channel, and it is no longer a formula for releasing the exterior. (A single herb addition creates a significant difference; how can the modifications in formula composition be neglected!) In cases of difficult urination, combining Ephedrae Herba (Mahuang) and Semen Armeniacae Amarum (Xingren) with Bazheng San results in an immediate response upon adding these two herbs internally, because when the external orifices are unblocked, the internal orifices become unblocked, and when the upper orifices are unblocked, the lower orifices naturally flow freely. While I was at Tiaoxi, I treated a patient with edema characterized by abdominal distension and skin swelling. After long-term use of Bazheng San, Hupo San, Wuzi Yanzong Wan, and Wupi Yin, the patient still suffered from dribbling urine and extreme pain. I said, "Although this is a deficiency syndrome, if water metabolism fails, the edema will not subside, and if the edema does not subside, how can the Healthy Qi (Zheng Qi) recover?" It was summer, so I dared not use Ephedrae Herba (Mahuang) for fear of Yang escape and continuous sweating. Instead, I prescribed equal parts of Perillae Folium (Zisuye), Saposhnikoviae Radix (Fangfeng), and Semen Armeniacae Amarum (Xingren), decocted in water for warm intake, covered with blankets to induce slight sweating, which resulted in the prompt discharge of water via urination. The next day, upon visiting the patient's room, I found that several buckets' worth of water had been spilled around the bed, and all bedding and curtains were thoroughly soaked. The patient stated, "After taking the medicine yesterday, without any effort to induce sweating, my urine flowed like a stream, too fast to reach the chamber pot, so I urinated while sitting on the bed, hence the mess below. By dawn, unexpectedly, urination continued, too urgent to get out of bed, hence the wet bedding. Now, my abdominal fullness and swelling have disappeared, and all pain and discomfort are resolved. I deeply appreciate your miraculous healing power." I replied, "Not yet. This is merely treating the branch in acute situations. Your etiology involves damage to Fire (Heart/Mingmen Fire) and Earth (Spleen), leading to water flooding, which is a chronic deficiency syndrome. Fire represents the original Qi (Yuan Qi) of the body; it is necessary to wait for the recovery of Spleen Qi and Original Qi before ensuring complete health." I then departed and prescribed Liujunzi Tang minus Glycyrrhizae Radix (Gancao), added with Atractylodis Rhizoma (Cangzhu), Magnoliae Officinalis Cortex (Houpo), Zingiberis Rhizoma Preparatum (Paojiang), and Aconiti Lateralis Radix Praeparata (Shufuzi), to be decocted strongly and taken warm daily. I also prepared a batch of pills from this formula for administration at Si hour (9-11 AM) and Wei hour (1-3 PM), thereby discontinuing the decoction. Half a year later, the patient's brother came to thank me with local products, saying, "My younger brother has fully recovered." I said, "In such syndromes, even if water metabolism resumes, if Healthy Qi does not recover, death from recurring swelling is common. My patient survived due to his destiny not being ended, not solely due to my merit. Nevertheless, where pathogens gather, Healthy Qi must be deficient. If, at the initial stage of swelling, methods of inducing sweating and promoting water metabolism are employed, Healthy Qi can recover easily. Physicians who do not know these methods and rely solely on draining and purgative herbs to promote urination may reduce swelling but fail to eliminate the root cause through the Weilu (gate of the kidney/bladder), akin to diverting disaster to a neighboring state! Long-term use of draining herbs depletes Healthy Qi day by day; prolonged retention of water extinguishes Fire and Earth gradually. Only then applying this method would be of no avail!"