海藻，味苦、咸，气寒，无毒。云有毒者，非。反甘草。入脾。治项间瘰 ，颈下瘿囊，
利
水道，通癃闭成淋，泻水气，除胀满作肿，辟百邪鬼魅，止偏坠疝疼。此物专能消坚硬之病
，盖咸能软坚也。然而单用此一味，正未能取效，随所生之病，加入引经之品，则无坚不散
矣。
或问海藻消坚致效，亦有试而言之乎？夫药必有试而言之，则神农氏又将何试哉。虽然
言而
未试，不若试而后言之为验。予游燕赵，遇中表之子，谈及伊芳母生瘿，求于余。余用海藻五
钱、茯苓五钱、半夏一钱、白术五钱、甘草一钱、陈皮五分、白芥子一钱、桔梗一钱，水煎
服，四剂而瘿减半，再服四剂，而瘿尽消，海藻治瘿之验如此，其他攻坚，不因此而可信乎
。
甘遂，味苦、甘，气大寒，有毒，反甘草。入胃、脾、膀胱、大小肠五经。破症坚积聚
如神
，退面目浮肿，祛胸中水结，尤能利水。此物逐水湿而功缓，牵牛逐水湿而功速，二味相配
，则缓者不缓，而速者不速矣。然而甘遂亦不可轻用也。甘遂只能利真湿之病，不能利假湿
之病，水自下而侵上者，湿之真者也；水自上而侵下者，湿之假者也。真湿可用甘遂，以开
其水道∶假湿不可用甘遂，以决其上泄。真湿为水邪之实，假湿乃元气之虚。虚症而用实治
之法，不犯虚虚之戒乎。故一决而旋亡也，可不慎哉！
或问牵牛、甘遂，仲景张公合而成方，以治水肿鼓胀者，神效无比。但牵牛利水，其功
甚捷
，何必又用甘遂，以牵其时耶？嗟乎。此正张夫子用药之神，非浅学人所能窥也。子不见治
河之法乎。洪水滔天，九州皆水也，治水从何处治起，必从上流而先治之，上流疏浚而清其
源，则下流无难治也。倘只开决其下流，水未尝不竟精大泄，然而只能泄其下流之水，而上
流之水，壅塞保存于州湖者正多，尾闾气泄，而上游澎湃，民能宁居乎。故治水者必统上下
而兼治，人身何独不然。仲景夫子因甘遂于牵牛之中者，正得此意，而通之以利湿也。牵牛
性迅，正恐太猛，泻水太急，肢体皮毛之内、头面手足之间，未必肠胃脾内之易于祛逐。加
入甘遂之迂缓，则宽猛相济，缓急得宜，在上之水既易于分消，而在下之水又无难于迅决。
于
是肢体皮毛、头面、手足之水不能少留，尽从膀胱而出，即脾、胃、大小肠内之水，亦无不
从大小便而罄下矣。倘只用牵牛，不用甘遂，则过于急迫，未免下焦干涸而上焦喘满，反成
不可救援之病。倘只用甘遂，不用牵牛，则过迂徐，未免上焦宽快而下焦阻塞，又成不可收
拾之 。仲景夫子合而成方，所以取效甚神，既收其功，又无其害也。
或问牵牛性急，甘遂性缓，故合而成功。吾子只言其上、下二焦之利益，尚未言及中焦
也，
得毋二味合用，可不利于中焦乎？夫牵牛、甘遂合而用之，使上、下二焦之利益者，正所以
顾中焦也。下焦阻塞，水必返于中焦而成壅闭矣。上焦喘满，水必流于中焦而成痞胀矣。今
用牵牛，并用甘遂，则上、下二焦均利，而中焦有不安然者乎。
或疑甘遂虽性缓，然祛逐水湿，未尝不峻烈也，或用牵牛，又用甘遂，不更助其虐乎？
夫甘
逐真正之水湿，何患其虐。若非水湿之症，单用甘遂，尚且不可，况益之以牵牛乎。惟其真
是水湿，故并用而不相悖也。
或问笔峰杂兴载治转脬，用甘遂末一钱，猪苓汤调下立通，可以为训乎？不可为训乎？
夫转脬
多由于火，而甘遂大寒，泄之似乎相宜。不知转脬之火，乃肾中之火不通于膀胱，虚火遏抑
而不得通，非脬之真转也。人之脬转立死矣，安能久活哉。
海藻，味苦、咸，气寒，无毒。说它有毒的，是不对的。它与甘草相反（十八反）。入脾经。治疗颈部两侧的瘰疬（淋巴结结核），颈下的瘿囊（甲状腺肿），通利水道，治疗小便不通引起的淋证，泻除水气，消除因胀满引起的浮肿，辟除各种邪气鬼魅，治疗偏坠疝气疼痛。这种药物专门能消除坚硬的病证，大概是因为咸味能软坚散结的缘故。然而单用这一味药，往往不能取得疗效，根据所患疾病的不同，加入引导药物到达病所的引经药，那么没有不消散的坚硬病证了。
有人问：海藻消除坚硬病证而见效，也是经过尝试才说的吗？如果药物必须经过尝试才能说，那么神农氏又去尝试什么呢？虽然如此，只说不做，不如先尝试后说更为可靠。我游历燕赵之地时，遇到表亲家的儿子，谈到他母亲生了瘿病，向我求治。我用海藻五钱、茯苓五钱、半夏一钱、白术五钱、甘草一钱、陈皮五分、白芥子一钱、桔梗一钱，水煎服，服用四剂后瘿病减半，再服用四剂，瘿病完全消失，海藻治疗瘿病的验证就像这样，其他攻坚散结的功效，难道不是因此可以相信吗？
甘遂，味苦、甘，气大寒，有毒，与甘草相反。入胃、脾、膀胱、大肠、小肠五经。破除症瘕积聚（腹内肿块）如神，消退面目浮肿，祛除胸中水饮结聚，尤其擅长利水。这种药物驱逐水湿的作用较缓，牵牛子驱逐水湿的作用较快，两味药配合使用，则缓慢的不显得慢，快速的不显得快了。然而甘遂也不可轻易使用。甘遂只能治疗真正的水湿病，不能治疗假性的水湿病。水从下部向上侵犯的，是真正的水湿；水从上向下侵犯的，是假性的水湿。真正的水湿可以用甘遂，以开通水道；假性的水湿不可用甘遂，以免导致上部泄泻。真正的水湿是水邪的实证，假性的水湿是元气的虚证。虚证如果用治实的方法，不是犯了使虚者更虚的禁忌吗？一旦决泄就会随即死亡，能不谨慎吗！
有人问：牵牛子和甘遂，张仲景公合方而成，用来治疗水肿鼓胀，效果神奇无比。但牵牛子利水，功效非常快捷，为什么还要用甘遂来牵制它的速度呢？唉！这正是张仲景先生用药的神妙之处，不是浅薄学识的人所能窥探的。您没看过治理河水的方法吗？洪水滔天，九州都是水，治水从哪里开始治？必须从上游先治，上游疏浚并澄清源头，那么下游就没有难治的了。如果只开决下游，水未尝不会大量泄出，然而只能泄出下游的水，而上游的水，壅塞保存在州湖中的正多，尾闾之气泄出，而上游波涛汹涌，百姓能安宁居住吗？所以治水的人必须统筹上下兼治，人身难道唯独不是这样吗？张仲景先生在牵牛子中加入甘遂，正是得到这个意思，从而通利水湿。牵牛子性质迅疾，正担心它太猛烈，泻水太快，肢体皮毛之内、头面手足之间，未必比肠胃脾内的水湿容易祛除。加入甘遂的迂缓，则宽猛相互调剂，缓急得当，在上部的水既易于分消，而在下部的水又没有难以迅速决出的困难。于是肢体皮毛、头面、手足的水不能稍留，全部从膀胱排出，即使是脾、胃、大肠、小肠内的水，也没有不从大小便排尽的。如果只用牵牛子，不用甘遂，则过于急迫，未免下焦干涸而上焦喘满，反而成为不可救援的病证。如果只用甘遂，不用牵牛子，则过于迂缓，未免上焦宽快而下焦阻塞，又成为不可收拾的病证。张仲景先生合方而成，所以取效非常神奇，既收其功效，又没有其危害。
有人问：牵牛子性急，甘遂性缓，所以合用成功。我只说了它们对上、下二焦的利益，还没有说到中焦，莫非这两味药合用，会对中焦不利吗？牵牛子和甘遂合用，使上、下二焦得利，正是为了顾护中焦。下焦阻塞，水必然返流于中焦而成壅闭；上焦喘满，水必然流注于中焦而成痞满胀气。现在用牵牛子，并用甘遂，则上、下二焦均得利，而中焦有不安然吗？
有人怀疑：甘遂虽然性缓，但祛逐水湿，未尝不峻烈，如果用牵牛子，又用甘遂，不是更助长其暴虐吗？甘遂驱逐真正的水湿，何必担心其暴虐。如果不是水湿的病证，单用甘遂尚且不可以，何况再加上牵牛子呢？正因为是真水湿，所以并用而不相违背。
有人问：《笔峰杂兴》记载治疗转脬（尿潴留），用甘遂末一钱，猪苓汤调服立即通畅，可以作为准则吗？不可以作为准则吗？转脬多由于火，而甘遂大寒，泄之似乎适宜。不知道转脬的火，是肾中之火不通于膀胱，虚火遏抑而不能通，并非膀胱真的扭转。人的膀胱如果真的扭转就会立即死亡，怎么能长久存活呢？
Sargassum (Haizao), with a bitter and salty taste, and a cold nature, is non-toxic. The claim that it is toxic is incorrect. It is incompatible with Glycyrrhizae Radix et Rhizoma (Gancao). It enters the Spleen meridian. It treats scrofula (lymph node tuberculosis) in the neck area and goiter (thyroid swelling) under the neck; it promotes urination, treats stranguria caused by urinary retention, drains water qi, eliminates distension and edema, wards off various evil spirits and demons, and alleviates hernia pain characterized by unilateral descent. This substance specializes in dissipating hard and solid pathologies, likely because the salty flavor can soften hardness. However, using this single herb alone often fails to achieve efficacy. By adding guiding herbs (Yinjing zhi pin) appropriate to the specific disease, no solid pathology will remain undissipated.
Someone asked: "Does Sargassum's efficacy in dissipating solidity come from empirical testing?" If medicines must be tested before being described, then what did Shennong test? Nevertheless, speaking without testing is less reliable than testing before speaking. While traveling in the Yan and Zhao regions, I encountered the son of a maternal relative, who mentioned his mother suffered from goiter and sought my treatment. I prescribed Sargassum (Haizao) 5 qian, Poria (Fuling) 5 qian, Pinelliae Rhizoma Preparatum (Banxia) 1 qian, Atractylodis Macrocephalae Rhizoma (Baizhu) 5 qian, Glycyrrhizae Radix et Rhizoma (Gancao) 1 qian, Citri Reticulatae Pericarpium (Chenpi) 0.5 qian, Sinapis Albae Semen (Baijiezi) 1 qian, and Platycodonis Radix (Jiegeng) 1 qian, decocted in water and taken orally. After four doses, the goiter reduced by half; after another four doses, the goiter completely disappeared. Such is the verified efficacy of Sargassum in treating goiter. Can we not trust its other abilities to break up accumulations based on this evidence?
Kansui Radix (Gansui), with a bitter and sweet taste, and a greatly cold nature, is toxic. It is incompatible with Glycyrrhizae Radix et Rhizoma (Gancao). It enters the Stomach, Spleen, Bladder, Large Intestine, and Small Intestine meridians. It miraculously breaks down masses and accumulations (Zhengji), reduces facial and ocular edema, removes fluid retention in the chest, and is particularly effective in promoting diuresis. This herb drains dampness and water slowly, whereas Pharbitidis Semen (Qianniuzi) drains them rapidly. When combined, the slow action becomes efficient, and the rapid action becomes moderated. However, Kansui Radix (Gansui) should not be used lightly. Kansui Radix (Gansui) can only treat true damp-water pathologies, not false ones. Water invading from below upwards constitutes true dampness; water invading from above downwards constitutes false dampness. True dampness can be treated with Kansui Radix (Gansui) to open the water pathways; false dampness should not be treated with it, as it would cause upper leakage. True dampness represents an excess of water pathogens, while false dampness indicates deficiency of primordial Qi. Applying excess-treatment methods to a deficiency condition violates the prohibition against further weakening the deficient. Once drained, death may follow immediately; how can one not be cautious!
Someone asked: "Zhang Zhongjing combined Pharbitidis Semen (Qianniuzi) and Kansui Radix (Gansui) into formulas to treat edema and abdominal distension with miraculous effect. Since Phariitidis Semen (Qianniuzi) promotes diuresis very swiftly, why is Kansui Radix (Gansui) needed to moderate its speed?" Alas! This demonstrates the divine skill of Master Zhang in prescribing, which is beyond the comprehension of those with shallow learning. Have you not observed methods of river management? When floods rise to the sky and the nine provinces are submerged, where does one begin to manage the water? One must start from the upper reaches. If the source is dredged and cleared upstream, managing the downstream becomes easy. If one only opens the downstream outlets, although much water may drain out, the water obstructed and stored in lakes upstream remains abundant. With the tail end leaking but the upstream surging, can the people live in peace? Therefore, water managers must address both upper and lower reaches simultaneously. Is the human body any different? Master Zhang included Kansui Radix (Gansui) among Phariitidis Semen (Qianniuzi) precisely to grasp this principle, thereby facilitating the drainage of dampness. Phariitidis Semen (Qianniuzi) acts swiftly, raising concerns that it might be too aggressive, draining water too urgently so that fluids in the limbs, skin, hair, head, face, hands, and feet might not be as easily expelled as those in the intestines, stomach, and spleen. Adding the moderating influence of Kansui Radix (Gansui) balances harshness and gentleness, ensuring appropriate pacing. Fluids in the upper part become easier to disperse, while fluids in the lower part are not difficult to rapidly discharge. Consequently, fluids in the limbs, skin, head, face, and hands cannot linger; they exit through the Bladder. Even fluids in the Spleen, Stomach, Large Intestine, and Small Intestine are thoroughly evacuated via urine and feces. If only Phariitidis Semen (Qianniuzi) were used without Kansui Radix (Gansui), the action would be too urgent, potentially causing dryness in the lower jiao and panting/fullness in the upper jiao, resulting in an incurable condition. If only Kansui Radix (Gansui) were used without Phariitidis Semen (Qianniuzi), the action would be too sluggish, potentially causing relief in the upper jiao but obstruction in the lower jiao, leading to an unmanageable situation. Master Zhang’s combination achieves miraculous results, gaining efficacy without harm.
Someone asked: "Phariitidis Semen (Qianniuzi) is swift, and Kansui Radix (Gansui) is slow, so their combination succeeds. You have discussed benefits for the upper and lower jiao, but not the middle jiao. Could their combination be detrimental to the middle jiao?" The combination of Phariitidis Semen (Qianniuzi) and Kansui Radix (Gansui), benefiting the upper and lower jiao, actually protects the middle jiao. Obstruction in the lower jiao causes water to reflux into the middle jiao, creating blockage. Panting and fullness in the upper jiao cause water to flow into the middle jiao, forming glomus and distension. Now, using both Phariitidis Semen (Qianniuzi) and Kansui Radix (Gansui) ensures both upper and lower jiao benefit, leaving the middle jiao secure.
Some suspect: "Although Kansui Radix (Gansui) is slow-acting, its expulsion of damp-water is still fierce. Using Phariitidis Semen (Qianniuzi) together with Kansui Radix (Gansui) might exacerbate this fierceness." If it is truly damp-water, why worry about fierceness? If it is not a damp-water condition, even using Kansui Radix (Gansui) alone is inadvisable, let alone adding Phariitidis Semen (Qianniuzi). Precisely because it is true damp-water, they can be used together without conflict.
Someone asked: "'Bifeng Zaxing' records treating urinary retention (Zhuanpao) using 1 qian of Kansui Radix (Gansui) powder, taken with Zhu Ling Tang, resulting in immediate passage. Can this serve as a guideline?" No, it cannot. Urinary retention is mostly due to fire, and since Kansui Radix (Gansui) is greatly cold, draining seems appropriate. However, the 'fire' in urinary retention refers to Kidney fire failing to communicate with the Bladder, where deficient fire is suppressed and unable to flow freely; it is not a true physical twisting of the bladder. If the bladder were truly twisted, death would occur instantly, and survival would not be prolonged.