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Banxia (Pinelliae Rhizoma) has a pungent flavor and neutral qi. Pungency can open up stagnation, while neutrality can direct rebellious qi downward. It is a crucial herb for treating vomiting and chest fullness. Vomiting accompanied by chest fullness constitutes a Shaoyang syndrome; therefore, Xiaochaihu Tang (Minor Bupleurum Decoction) cannot omit this herb. Extending this logic, its applications in treating epigastric stuffiness, abdominal distension, cough, and throat obstruction all rely on its efficacy in opening stagnation and directing qi downward.

The rationale for using Banxia is often linked to Erchen Tang (Two-Cured Decoction), which is believed to moisten the large intestine, and Banshui Wan (Half-Sulfur Pill), used for deficiency-type or cold-type constipation. Although it appears moistening rather than drying, upon investigation, does it not possess drying properties? When administered to patients with depleted body fluids and no dampness, it will immediately cause harm. Only Zhang Zhongjing utilized its strengths while discarding its weaknesses. In cases of "Wei Fan" (stomach reversal due to spleen injury and failure to digest), where there is no pathogenic retention but rather spleen deficiency, he paired Banxia with Renshen (Ginseng Radix et Rhizoma) and added Bai Mi (White Honey). This neutralizes the drying nature of Banxia, allowing the grain qi in the stomach to circulate. Similarly, in the formulas Zhuyegao Shitang (Bamboo Leaf and Gypsum Decoction), Maimendong Tang (Ophiopogon Decoction), and Wenjing Tang (Warming the Menses Decoction), one cannot simply claim that Banxia damages fluids. The herbs paired with Banxia—such as Zhuye (Bamboo Leaves), Shigao (Gypsum Fibrosum), Renshen, Maimendong (Ophiopogonis Radix), Gancao (Licorice Root), Jingmi (Glutinous Rice), Ejiao (Donkey-Hide Gelatin), and Danpi (Moutan Cortex)—transform Banxia's drying nature while unleashing its ability to open and descend. This exemplifies the principle of transformation and adaptation.

In the Xiao Qinglong Tang (Minor Blue-Green Dragon Decoction), it states: "If thirsty, remove Banxia." In the Xiaochaihu Tang, it also states: "If thirsty, remove Banxia." These are clear evidences that Banxia is indeed drying. However, the drying nature of Banxia... [Text cuts off]

For Xiao Qinglong Tang, if there is slight diarrhea, Mahuang (Ephedrae Herba) should be removed and Rao Hua (Genkwa Flos) added. Diarrhea indicates that water qi does not flow directly to the Bladder. If Mahuang is used to raise Taiyang qi, the water passages become more obstructed, causing water qi to overflow and lead to distension. This aligns with the statement in the Taiyin chapter: "Diarrhea with undigested food contraindicates attacking the exterior; sweating will inevitably cause distension." Rao Hua, according to the *Shennong Ben Cao Jing*, primarily purges stubborn accumulations in the intestines and promotes urination. Thus, slight diarrhea prevents stagnation/dysentery, and upper-body water qi is also eliminated. Furthermore, its medicinal action resides in the flower, which acts both internally and externally. Therefore, the *Ben Cao Jing* also records its use for treating shanghan (cold damage), wen nue (warm malaria), and dietary-induced chills and fever. If Fuling (Poria) and Zexie (Alisma Rhizoma) were used to treat slight diarrhea, it would cause the exterior pathogen to sink inward. This is why Zhang Zhongjing chose Rao Hua.

The juice of Tusizi (Cuscutae Semen) removes facial pigmentation. Xu Shi did not understand this; Ye Tianshi attributed it to ascending Shaoyin qi, but Xu Shi remained unconvinced. In fact, this is quite easy to understand. Cuscuta vines wrap around host plants; when the root is severed, the seeds contain abundant lipid essence, enabling them to tonify Kidney Essence and exhibit ascending properties. The face is the pathway of the Yangming meridians. Tusizi is sweet, pungent, and warm; it travels via the Yangming meridian upward to the face to exert its lubricating and moisturizing effects. How could facial pigmentation remain? I offer this explanation to resolve Xu Shi's doubts.

The Spleen governs the muscles. Tusizi possesses the characteristic of parasitic roots that continue to function even after detachment, thereby tonifying the Spleen. Consequently, it can enrich Wei Qi (Defensive Qi) and promote physical robustness. The *Laoxue'an Biji* notes that long-term use may cause carbuncles. Other Kidney-tonifying herbs merely tonify, whereas Tusizi incorporates ascending action within tonification. Thus, it treats spontaneous emission of essence and dribbling urine, and should not be classified merely as an astringent. It is used to treat Xiao Ke (Wasting-Thirst)... [Text cuts off]