Library

(Sourced from the Song Dynasty *Tujing Bencao*)

[Names] Li Shizhen stated: The name is derived from its shape resembling wheat rice, belonging to an ideogrammatic naming convention.

[Collection and Explanation] Li Shizhen stated: Li Xun pointed out: *Maifan Shi* (Wheat-Rice Stone) can be found everywhere in mountain streams. These stones vary in size; some are like fists, some like goose eggs, some like shallow bowls, and some like cakes. Generally, their shape resembles a clump of wheat rice gathered together, with granular spots like beans or millet grains, and their color is yellowish-white. One simply needs to search among the granite stones in stream beds for those with this specific appearance. Ancient prescriptions claimed that stones previously used as millstones were superior, which was incorrect. This stone cannot be used as a millstone. If this stone is unavailable, one may substitute it with stones from old grain mills near the teeth-contact area, taking advantage of its inherent "wheat nature."

[Flavor and Properties] Sweet flavor, warm temperature, non-toxic.

[Indications] All types of carbuncles and furuncles, specifically back abscesses (*Fabei*, 发背疮) (Li Shizhen).

[Elucidation] Su Song stated: Generally, most stone-based medicines treat carbuncles and furuncles. The *Maifan Shi Gao* (Wheat-Rice Stone Plaster) circulated in the world is highly effective for treating back abscesses; it was a secret prescription of Lü Zihua, a hermit from Mount Zhong. Pei Yuanwai tempted him with official rank and title, while the Prefect of Henan threatened him with severe punishment. Lü Zihua renounced all hopes of glory and wealth, guarding the secret until death without transmitting it.

The preparation method is as follows: Crush this stone into pieces the size of chessmen (fire red-hot with charcoal, quench in rice vinegar, repeat this process ten times, then grind into powder and sift finely. Place in a mortar and pestle, where several people take turns grinding for five to seven days, requiring it to be as fine as flour) four liang; Deer horn, one set (must be freshly taken including the cranial bone; naturally shed horns are unusable. Cut into segments two to three cun long, fire red-hot with charcoal until smoke ceases, then grind into fine powder) two liang; *Bailian* (Radix Ampelopsis, 白蔹) (raw, ground into powder) two liang. Use three-year-old rice vinegar, place in a silver or ceramic vessel, boil until bubbles resemble fish eyes. Gradually add the medicinal powder while stirring continuously with a bamboo stick. Simmer for one to two hours until the consistency is appropriate. Pour into a basin, allow to cool, cover with paper to prevent dust entry. When applying, use a goose feather to brush the plaster onto the reddened areas surrounding the swelling, leaving a coin-sized hole in the center to vent qi. If pus has not yet formed, it will resolve internally; if a head has formed, it will shrink; if already ulcerated, it will drain pus like a rapid stream. If the disease has persisted for a long time causing muscle rot and exposure of bones/tendons, apply the plaster on fine cloth as a patch. Change when dry; daily application promotes wound contraction. As long as the center remains unblocked for ventilation, no case will fail to heal. For already ulcerated wounds, first wash away pus and blood with pig trotter decoction, then dry with old cloth before applying medication. Such wounds must strictly avoid manual touch; tender flesh should not be blown upon by mouth breath, nor viewed by individuals with axillary odor, menstruating women, or pregnant women. These conditions are also taboo during the compounding of the medicine.

Initially, wash and change the dressing once daily; after ten days, change every two days. This medicine must be extremely fine to be effective; if not fine enough, application causes intense pain.

This prescription was already recorded in Sun Simiao's *Qianjin Yueling* (Monthly Directions from the Essential Prescriptions Worth a Thousand Gold), though not as detailed as here. Additionally, Ma Siming of the Northern Qi dynasty treated Yang Zunyan's back abscess by taking coarse yellow stone the size of a goose egg, heating it red-hot in a fierce fire, and quenching it in thick vinegar. Crumbs would fall into the vinegar. Repeat heating and quenching until the stone is completely consumed. Take the crumbs, dry them in the sun, pound and sift into an extremely fine powder, mix with vinegar, and apply. Healing occurs immediately. Liu Yuxi referred to this in his *Chuanxin Fang* (Prescriptions Transmitted with Confidence) as the "Refined Stone Method," used for applying to sores and swellings with universal efficacy.