本经杜仲主腰脊痛，脊有误作膝者，注家即以腰膝释之。不知杜仲辛甘色黑，皮内有白
丝缠联，为肝肾气药非血药。其温补肝肾之功，实在腰脊。性温化湿而甘能守中，不特腰脊
痛可止，即阴下痒湿小便余沥何不可已。别录谓脚中酸疼不欲践地。不俗之故，自在腰脊，
与不能有异。总当以主腰脊痛为用是物之主脑。即后世治频惯堕胎，亦岂为脚膝事哉。
楝实苦入心，酸入肝，寒入肾，为心肝肾三经之药。苦寒清热下行而酸复迫之，故导上
中之热，由小便水道而出，其势甚捷。
本经主温疾伤寒大热烦狂。温疾伤寒即温病，大热而至烦狂，是热无所泄，缓则生变，
故以此亟泄其热，非谓温病可全恃楝实也。
心痛腹痛之为热痛者，用之靡不奏效。即牙宣出血不止，以楝实末裹塞齿龈即止。其导
热下行之速，真有可立待者矣。
疝有热有寒。史记太仓公治疝用火齐汤，热疝也。金匮治疝用大乌头煎，寒疝也。楝实
为治疝要药，则于寒郁热者为宜。盖肝肾内寓真阳，阴锢之而阳不得达，则寒亦酿热。楝实
酸苦，能入而涌泄之，即刘氏所谓导气达阳也。病本属寒，不能舍巴豆故纸等药而独建其功，
用
昔人治遗精如固阳丸、鹿茸益精丸、既济固真丹，治真阳上越气喘痰鸣如黑锡丹，皆其
中有
《本经》记载杜仲主治腰脊疼痛，其中“脊”字有误作“膝”的情况，注释家便以此解释为治疗腰膝疼痛。却不知道杜仲味辛、甘，色黑，皮内含有白色丝状物缠绕连接，属于调理肝肾气分的药物，而非调理血分的药物。它温补肝肾的功效，确实体现在腰脊部位。其性温能化湿，味甘能守中，不仅腰脊疼痛可以停止，即使是阴部瘙痒潮湿、小便淋漓不尽的症状，又有什么不能治愈的呢？《别录》记载它能治疗脚中酸痛不想踩地。这种不俗套的作用，根本原因自然在于腰脊，与（治疗腰膝）没有本质区别。总之应当以主治腰脊疼痛作为该药的主要功效。即使后世用它来治疗习惯性流产，难道是为了治疗脚膝疾病吗？
楝实味苦入心经，味酸入肝经，性寒入肾经，是心、肝、肾三经的药物。苦寒之性能清热下行，而酸味又促使它下行，所以能引导上部和中部的热邪，从小便水道排出，其势非常迅速。
《本经》记载它主治温病伤寒引起的大热、烦躁、狂乱。温病伤寒即温病，大热发展到烦躁狂乱的程度，是因为热邪无处宣泄，如果迟缓就会发生变故，所以用此药紧急泄热，并不是说治疗温病可以完全依赖楝实。
对于因热邪引起的心痛、腹痛，使用它无不奏效。即使是牙龈出血不止，用楝实粉末包裹塞入齿龈即可止血。它导热下行的速度，真是立竿见影。
疝气有热疝和寒疝之分。《史记》记载太仓公治疗疝气用火齐汤，这是治疗热疝。《金匮要略》治疗疝气用大乌头煎，这是治疗寒疝。楝实是治疗疝气的重要药物，那么对于寒郁化热的情况最为适宜。因为肝肾内部寓居着真阳，如果被阴寒固结，阳气就不能通达，那么寒邪也会酿生热邪。楝实味酸、苦，能进入体内并涌吐泄热，这就是刘氏所说的引导气机通达阳气。病本属寒，不能舍弃巴豆、破故纸等药物而单独依靠楝实建立功劳。古人治疗遗精如固阳丸、鹿茸益精丸、既济固真丹，治疗真阳上越导致的气喘痰鸣如黑锡丹，其中都有楝实的运用。
*Ben Jing* (Shennong's Classic of Materia Medica) records that Eucommia Bark (Duzhong, 杜仲) mainly treats lower back and spinal pain. The character "spine" (Ji, 脊) is sometimes erroneously written as "knee" (Xi, 膝); commentators have thus interpreted it as treating both the waist and knees. However, one should not know that Eucommia Bark is pungent and sweet in flavor, black in color, and contains white fibrous strands within its bark; it is a herb for regulating Qi of the Liver and Kidney, not Blood. Its efficacy in warming and tonifying the Liver and Kidney truly lies in the lower back and spine. Its warm nature transforms dampness, and its sweet flavor stabilizes the Middle Jiao; therefore, not only can lower back and spinal pain be stopped, but symptoms such as itching and dampness in the genital area and dribbling urine can also be resolved. *Bie Lu* (Additional Records) states it treats soreness and pain in the feet where one does not wish to tread on the ground. This unorthodox utility naturally stems from its effect on the lower back and spine, differing little from other indications. Ultimately, its primary function should be regarded as treating lower back and spinal pain. Even when later generations used it to treat habitual miscarriage, was it for the sake of foot and knee ailments?
Toosendan Fruit (Chuanlianzi, 楝实) enters the Heart meridian with its bitter flavor, the Liver meridian with its sour flavor, and the Kidney meridian with its cold nature; it is a herb for the Heart, Liver, and Kidney meridians. Its bitter-cold nature clears heat and directs it downward, while its sour flavor further compels this downward movement; thus, it guides heat from the Upper and Middle Jiao out through the urinary pathway, with great speed.
*Ben Jing* records it mainly treats severe fever, irritability, and mania caused by Warm Diseases (Wen Bing, 温病) or Cold Damage (Shang Han, 伤寒). Warm Disease and Cold Damage here refer to Warm Diseases; when high fever progresses to irritability and mania, it indicates that heat has no outlet, and delay may lead to complications. Therefore, this herb is used to urgently drain the heat, not to suggest that Warm Diseases can be entirely treated relying solely on Toosendan Fruit.
For heart pain and abdominal pain caused by heat, its use is invariably effective. Even for persistent bleeding from gum disease (Ya Xuan, 牙宣), applying Toosendan Fruit powder packed into the gums stops the bleeding immediately. Its rapid ability to guide heat downward is indeed immediate.
Hernias (Shan, 疝) can be classified into heat hernias and cold hernias. *Records of the Grand Historian* records that Canghai Gong treated hernias using Huoqi Tang, which addresses heat hernias. *Essential Prescriptions Worth a Thousand Gold* treats hernias using Da Wutou Jian, addressing cold hernias. Toosendan Fruit is an essential herb for treating hernias, making it suitable for cases where cold stagnation transforms into heat. Since True Yang resides within the Liver and Kidney, if constrained by Yin-cold, Yang cannot circulate freely, causing cold to generate heat. Toosendan Fruit, being sour and bitter, can enter the interior and induce vomiting/draining, which aligns with Liu's description of guiding Qi to reach Yang. Although the root pathology is cold, one cannot rely solely on Toosendan Fruit without discarding herbs like Croton Seed (Badou, 巴豆) or Psoralea Fruit (Guzhi, 破故纸). In ancient prescriptions for seminal emission, such as Guyang Wan, Lurong Yijing Wan, and Ji Ji Gu Zhen Dan, or for asthma and phlegm-rattle due to floating True Yang, such as Heixi Dan, Toosendan Fruit is included among the ingredients.