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Mu Gua (Chaenomeles Fruit) is sour in taste, warm in nature, and moist in texture. Its skin starts green and turns yellow, while its flesh starts white and turns red. It acts on the blood level of the Lung, Stomach, Liver, and Spleen. Substances that are moistening seem unsuitable for dampness syndromes. However, wind can overcome dampness, earth can control it, and by warming its qi to promote circulation, how could it not treat dampness complicated by cold? The Liver governs Wind-Wood; Wood becomes excessive when wet. Since it removes dampness and calms Wood, Wind naturally subsides. Its sour taste allows it to astringe but not disperse, to descend but not ascend. Therefore, it mainly treats conditions of tendon spasms or flaccidity. It is used more often in the Lower Jiao and less often in the Middle and Upper Jiao. Those who use this substance will have understood more than half of its application if they can discern why Zhang Zhongjing did not use it in formulas for Wind-Damp and Cold-Damp, and instead seek where it is applicable.

Tendon spasms arise from Huo Luan (Cholera-like syndrome). Huo Luan without tendon spasms is not within the scope of Mu Gua. The syndrome may be Cold or Heat, and the treatment methods are worlds apart; one must not harbor any bias. As for tendon spasms, I believe that even if it belongs to a Heat syndrome, there must be a slight accompaniment of Cold Qi. This is because tendons belong to the Liver; the Liver accepts Dampness but rejects Cold. Being both attracted to and repelled by these factors causes the tendons to spasm. The calf muscles belong to the Yangming channel. Mu Gua enters the Yangming channel; its ability to warm and moisten tendon spasms lies in its suitability for both natures. Unless there is urinary retention with no exit for pathogenic factors, one must examine ancient indications for Mu Gua, such as Hong Xiang Jiao (Foot Rot/Grain Disease) causing foot weakness, abdominal distension, and hypochondriac fullness. These are mostly combined with acrid-warm herbs. The purpose is not merely to expel Cold-Damp pathogens and gather scattered Qi. Although its function is descending and suppressing, it ultimately remains astringent. Thus, it is suitable for treating tendon twisting and deformity, but not for clamping and cramping. Only Xu Shuwei used Mu Gua to treat neck stiffness and tendon tension, stating that the Shaoyin tendon runs from the foot to the neck and is caused by pathogens affecting the Liver and Kidney. Although the disease manifests in the upper part, the root cause remains in the lower part. By using Ru Xiang (Olibanum/Gum Olibanum) and Mo Yao (Myrrha/Gum Myrrha) as assistants, it shows that he relied on them to extend the tendons, not on Mu Gua, which demonstrates this point clearly.

Pi Pa Ye (Loquat Leaf) has yellow hairs on its back. Yellow enters the Stomach, and hairs belong to the Lung. Its bitter and neutral taste allows it to harmonize the Lung and Stomach and direct Qi downward. *Bie Lu* (Divine Farmer's Materia Medica Supplement) states it treats sudden persistent hiccups. Zou did not specify the disease but explained it merely as "Yin harmonizing Yang" and "Yang entering Yin," which seems profound but is actually vague. "Su" refers to the sudden onset of hiccupping, and "Bu Zhi" means continuous. Hiccups are often sudden and continuous. Why is it indicated? Generally, when the Stomach is constrained by the Liver, Qi rebels upward; when Stomach Qi rebels and Lung Qi desires to descend, hiccups occur. Pi Pa Ye remains green and fresh without withering; its decoction is cold. It has the ability to suppress Liver Yang and enables both the Lung and Stomach to perform their functions of descending and receiving. Tao Hongjing said: "If there is no time to boil, chewing it and swallowing the juice also cures it." Its effect is so rapid. Thus, Shi Di (Persimmon Calyx) treats Cold hiccups, while Pi Pa Ye treats Heat hiccups. Are they not naturally opposing remedies?

Pi Pa Ye is frequently used for Heat cough and Heat vomiting, but rarely for Heat hiccups. However, once one recognizes Pi Pa Ye as an herb that directs Qi downward and treats Heat, using it for cough and hiccups will invariably hit the mark.