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*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.