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Shen Nong Ben Cao Jing (Divine Farmer's Materia Medica) and Tao Hongjing's Baopuzi both highly praise the efficacy of Broussonetia papyrifera fruit (Chushi, 楮实子). However, in prescription books, its use in tonifying formulas is rarely seen outside of Yang Shi's Huan Shao Dan (Restore Youth Pill). This is largely because it is inexpensive, and Daoist cultivation texts state that long-term consumption softens bones, while Jisheng Milan treats bone obstruction with it, leading to its neglect. No one has elucidated the reason behind this. I ponder that tonification and bone softening are not contradictory; the principle is simply profound. When planting paper mulberry, hemp must be interplanted. In winter, hemp provides warmth; in spring, burning hemp fertilizes the mulberry. Within three years, it grows into a large tree with white latex in branches and leaves, bark usable for paper and cloth, and deep red fruits that become sticky like maltose when decocted. This property aligns perfectly with certain conditions. However, for patterns of Kidney Yang deficiency with excess Yin, Yin deficiency with easy rising of Yang, or simultaneous deficiency of both Yin and Yang, it is unsuitable. This is the essence of Shen Nong Ben Cao Jing stating it treats impotence. A herb that tonifies Yin and extends Yang ensures that the tonified Yin rises with Yang, differing from pure Yin-filling herbs. Edema occurs when Yin fails to transform with Yang, causing water accumulation. Emaciated skin and muscles result from Yang lacking Yin support, leading to Qi deficiency. Blurred vision stems from Yin failing to ascend, leaving Yang without luster. The symptoms listed in Shen Nong Ben Cao Jing can all be addressed by Chushi. Then why does it soften bones? Bones belong to the Kidney; sweet flavors can damage the Kidney. When the Kidney is injured by Dampness, the waist and legs become sore and weak; Dampness is also Yin. Chushi is sweet and cold, nourishing Yin but not assisting Yang. Long-term use inevitably softens bones. This is due to improper syndrome differentiation and prescription formulation; what blame can be placed on Chushi? Understanding this principle allows its correct use for throat bi and bone obstruction, revealing its true merit. Wu Tingshao treated Emperor Liezu’s choking on maltose by using Chushi, which possesses Yin substance but Yang function, releasing the obstructed Qi of Shaoyin, and using sweet to guide sweet, hence its efficacy. Only Li Shizhen’s citation of Da Ming claiming it strengthens sinews and bones is misleading.

Mingyi Bielu records that Zhi Shi (Immature Bitter Orange) breaks solid accumulations and reduces distension. Here, "distension" refers to hard fullness; "breaking solid accumulation" implies purging retained food, seemingly less effective than Hou Po (Magnolia Bark) in dispersing Dampness-related distension, whereas Hou Po also treats upper jiao issues. However, Zhi Shi is an Qi-moving herb with bitter and sour flavors, governing hard distension in the chest and hypochondrium. Thus, Mingyi Bielu specifies "removing phlegm-pi" rather than "phlegm-fluid" for the chest/hypochondrium. Water is soft and mobile. But when stagnant, it colludes with food and fluids in the intestines and stomach, resisting simple diuresis. Hence, after mentioning removing chest/hypochondrial phlegm-pi, Mingyi Bielu adds "driving away stagnant water," not limited to the chest/hypochondrium. This likely refers to hard fullness in the intestines/stomach requiring Zhi Shi. The rationale for using Zhi Shi in Da Cheng Qi Tang and Xiao Cheng Qi Tang, as well as Zhi Shi Xie Bai Gui Zhi Tang, was detailed under Hou Po and will not be repeated.

Considering Mingyi Bielu’s mention of urgent epigastric pain, rebellious Qi, and wind-pain in the hypochondrium: Xiexin Decoctions treat Xin Pi (epigastric stuffiness), Da/Xiao Xianxiong Tang treat Jie Xiong (chest binding); Zhi Shi seems applicable but is excluded. Why? Pi is a deficient pathogen, suitable for mild dispersion, not aggressive attack. Jie Xiong is an excess pathogen, but clearing heat and draining water has specific herbs. Xiao Xianxiong Tang differs little from Xiexin formulas, merely adding Gua Lou (Trichosanthes Fruit) to descend turbid phlegm alongside Lian Ban Xia (Coptis and Pinellia); thus, Zhi Shi is unnecessary. What does Zhi Shi govern? Chest Bi and Jie Xiong both present with tenderness on pressure. The difference lies in one being Heat binding and the other Yang deficiency. Although Zhi Shi directs Qi downward (making the chest an unlikely site for retention) and is cold (potentially harming deficient Yang), Zhang Zhongjing employs it skillfully according to material properties. Ju Zhi Sheng Jiang Tang uses Tangerine Peel and Ginger to transform Qi upward, with Zhi Shi following to drain downward. Gui Zhi Sheng Jiang Zhi Shi Tang uses Cinnamon Twig and Ginger to transform Qi upward, with Zhi Shi following to drain. It is only used when Qi stagnation or hanging pain presents with hard fullness to drain. It is not named first because it serves as an assistant herb. In Da Chai Hu Tang, Chai Hu, Huang Qin, and Ban Xia treat chest fullness but cannot resolve epigastric hardness/pain; adding Zhi Shi resolves this because it drains hard fullness. The formula treats both exterior and interior: Da Huang, Zhi Shi, and Bai Shao attack the interior; Chai Hu, Huang Qin, Ban Xia, Sheng Jiang, and Da Zao release the exterior. Increased Sheng Jiang helps Zhi Shi resolve epigastric hardness, mirroring Ju Zhi Sheng Jiang Tang’s method for Chest Bi. Thus, Zhi Shi contributes significantly, yet is omitted from the name. Perhaps recognizing alternating chills and fever as Shaoyang disease, Chai Hu is the chief herb for Shaoyang, resolving Qi knots in the gut, justifying its leadership; "Da" indicates deviation from Xiao Chai Hu Tang’s standard method. In Zhi Zhu Tang, Bai Zhu eliminates fluid retention, while Zhi Shi drains hard fullness below the heart. Zhi Shi’s downward Qi is carried by sweet, heavy Bai Zhu to prevent rapid descent, lingering around the heart before reaching the abdomen, where it takes effect. This is another method of using Zhi Shi for subcardiac issues. Mingyi Bielu’s descriptions likely derive from deducing Zhang Zhongjing’s formulas.