味苦酸。此止言味而不言性，疑阙文也。后凡不言性者仿此。主寒湿痿痹，四肢拘挛
，膝痛不可屈伸，皆舒筋行血之功。逐血气，破瘀血也。伤热火烂，清热也。堕胎。降血气
也。久服，轻身耐老。血和之功。
此乃以其形而知其性也。凡物之根皆横生，而牛膝独直下，其长细而韧，酷似人筋，所
以能舒筋通脉，下血降气，为诸下达药之先导也。筋属肝，肝藏血，凡能舒筋之药，俱能治
血，故又为通利血脉之品。
味苦平。主心腹，去肠胃中结气，轻扬之体，能疏肠胃之滞气。饮气积聚，疏肠胃之
滞物。寒热邪气，驱经络之外邪。推陈致新。总上三者言之，邪去则正复也。久服，轻身，
明目益精。诸邪不能容，则正气流通，故有此效。
柴胡肠胃之药也。观经中所言治效，皆主肠胃，以其气味轻清，能于顽土中疏理滞气，
故其
功如此。天下惟木能疏土，前人皆指为少阳之药，是知其末，而未知其本也。张仲景小柴胡
汤专治少阳，以此为主药何也？按伤寒传经次第，先太阳，次阳明，次少阳。然则少阳虽在
太阳、阳明之间，而传经乃居阳明之后，过阳明而后入少阳，则少阳反在阳明之内也。盖以
所居之位言，则少阳在太阳、阳明之间，以从入之道言，则少阳在太阳、阳明之内，故治少
阳与太阳，绝不相干，而与阳明为近，如小柴胡汤之半夏、甘草，皆阳明之药也。惟其然，
故气味须轻清疏达，而后邪能透土以出，知此则仲景用柴胡之义明，而柴胡为肠胃之药亦明
矣。
味苦、酸。这里只提到了味道而没有提到药性，我怀疑是缺漏的文字。后世凡是只提味道不提药性的情况都仿照此例处理。主治寒湿引起的痿证和痹证，四肢拘挛抽搐，膝盖疼痛不能屈伸，这些都是舒筋活血的功效。驱逐血气中的瘀滞，破除瘀血。治疗因热邪损伤导致的肌肉腐烂，这是清热的作用。导致堕胎，这是降泄血气的功效。长期服用，能使身体轻盈、延缓衰老，这是血液调和的功效。
这是通过观察药物的形态来推知其药性。大凡植物的根都是横向生长的，而牛膝的根唯独垂直向下生长，它细长且坚韧，非常像人的筋腱，所以能够舒筋通脉，引血下行，降泄气机，作为各种具有下行作用的药物的先导。筋归属于肝，肝藏血，凡是能够舒筋的药物，都能治疗血分疾病，因此它又是疏通血脉的药材。
味苦、平。主治心腹部的病症，去除肠胃中郁结的气机，因其质地轻扬，能够疏解肠胃中的滞气。消除饮邪和气机积聚，疏解肠胃中的停滞之物。驱除寒热邪气，清除经络之外的外邪。推陈出新。综合以上三点来说，邪气去除则正气恢复。长期服用，能使人身体轻盈，明目并增益精气。因为各种邪气无法存留，正气得以流通，所以产生这样的效果。
柴胡是调理肠胃的药物。观察《神农本草经》中记载的治疗功效，都主要作用于肠胃，因为其气味轻清，能够在脾胃（顽土）中疏理滞气，所以功效如此。天下只有木能疏理土壤，前人都将柴胡指认为少阳经的药物，这是只知其一不知其二，只看到了末节而未探究本源。张仲景的小柴胡汤专门治疗少阳病，以此为主药为什么呢？按照伤寒病传变的次序，先传入太阳经，再传入阳明经，最后传入少阳经。既然少阳经虽然位于太阳经和阳明经之间，但在传变过程中却排在阳明经之后，经过阳明经后才进入少阳经，那么从位置关系上看，少阳经反而在阳明经的内部。大概从所处的位置来说，少阳经在太阳经和阳明经之间；但从传入的路径来说，少阳经在太阳经和阳明经的内部。所以治疗少阳病与太阳经绝不相干，而与阳明经关系密切，就像小柴胡汤中的半夏、甘草，都是治疗阳明经的药物。正因为如此，所以柴胡的气味必须轻清疏达，才能使邪气透出土层而出，明白了这一点，张仲景使用柴胡的用意就明确了，柴胡作为肠胃用药的道理也就清楚了。
Bitter and sour. This text mentions only the flavor and omits the nature, which leads to suspicion of missing text. Subsequent instances where the nature is not mentioned should follow this pattern. It primarily treats Wei Bi (flaccidity syndrome and bi-syndrome caused by cold-dampness), spasm and contracture of the four limbs, and knee pain with inability to flex or extend, all of which are attributed to the merit of relaxing sinews and promoting blood circulation. It expels blood qi and breaks up blood stasis. For injuries caused by fire-heat leading to tissue rot, it clears heat. It induces abortion, which is due to its ability to direct blood qi downward. Long-term use makes the body light and enhances resistance to aging, reflecting the merit of harmonizing blood.
This deduces the nature from the form. Generally, the roots of all plants grow horizontally, but the root of Achyranthes Bidentata (Niuxi, 牛膝) grows vertically downward. It is long, slender, and tough, closely resembling human sinews; therefore, it can relax sinews and unblock collaterals, direct blood downward, and descend qi, serving as a forerunner among drugs that have a descending action. Sinews belong to the Liver, and the Liver stores blood. Any drug that can relax sinews can also treat blood disorders; thus, it is also a substance that promotes the free flow of blood vessels.
Bitter and neutral. It primarily treats conditions of the heart and abdomen, removes knotted qi in the intestines and stomach. Being of a light and ascending nature, it can disperse stagnant qi in the intestines and stomach. It disperses accumulations of fluids and qi, and resolves stagnation in the intestines and stomach. It drives out pathogenic factors of cold and heat, eliminating external pathogens from the meridians. It pushes out the old and brings forth the new. Speaking generally of the above three points, when pathogens are expelled, healthy qi recovers. Long-term use makes the body light, brightens the eyes, and benefits essence. Since no pathogens can remain, healthy qi flows freely, hence this effect.
Chai Hu (Bupleuri Radix, 柴胡) is a medicine for the intestines and stomach. Observing the therapeutic effects recorded in the classic, they all primarily target the intestines and stomach. Because its flavor and nature are light and clear, it can regulate stagnant qi within the stubborn earth (Spleen/Stomach); thus, its efficacy is as described. Only wood can loosen soil. Previous scholars identified it solely as a Shaoyang (Lesser Yang) channel drug, knowing its branch but not its root. Why does Zhang Zhongjing's Xiao Chai Hu Tang (Minor Bupleurum Decoction) specifically treat Shaoyang disease using it as the chief ingredient? According to the sequence of transmission in Shanghan (Cold Damage), it first transmits to Taiyang (Greater Yang), then to Yangming (Bright Yang), and finally to Shaoyang. Although Shaoyang is located between Taiyang and Yangming anatomically, in terms of transmission order, it follows Yangming. Having passed through Yangming, it enters Shaoyang; thus, Shaoyang is actually internal to Yangming. From the perspective of location, Shaoyang is between Taiyang and Yangming; but from the perspective of the pathway of entry, Shaoyang is inside Taiyang and Yangming. Therefore, treating Shaoyang has nothing to do with Taiyang but is close to Yangming. For example, Ban Xia (Pinelliae Rhizoma) and Gan Cao (Glycyrrhizae Radix et Rhizoma) in Xiao Chai Hu Tang are both medicines for Yangming. Precisely because of this, its flavor and nature must be light, clear, and dispersing so that pathogens can penetrate the "earth" layer and exit. Understanding this clarifies Zhang Zhongjing's rationale for using Chai Hu and confirms that Chai Hu is a medicine for the intestines and stomach.