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Clear heat and purge fire, detoxify.
Sweet in taste and cold in nature. It circulates through the twelve meridians, possesses the efficacy of clearing heat and detoxifying (it can treat poisoning from various herbs, stones, minerals, and arsenic), promotes urination, relieves xiaoke (wasting and thirsting syndrome), treats diarrhea and dysentery. It should be used with the skin (as its cooling property resides primarily in the skin).

Made into powder, applying it externally to ulcerated smallpox sores is effective (A citizen recited the Guanyin Sutra with great sincerity; while traveling, he broke a leg and cried out to the Bodhisattva for help. In a dream, a monk gave him a prescription: stir-fry mung bean powder in a new pot until purple, mix with well water, apply thickly on paper as a patch, and secure with fir wood strips. The effect was miraculous).

Tonify the spleen, remove dampness, and dissipate summerheat.
Sweet in taste, warm in nature, with a fishy and fragrant odor. Its color is white with a slight yellow tint, making it the grain corresponding to the spleen. It regulates the spleen and warms the stomach, unblocks the Sanjiao (Triple Burner), descends turbid qi and ascends clear qi, dissipates summerheat and removes dampness (it can eliminate summerheat in the spleen and stomach), stops thirst and diarrhea, and specifically treats diseases of the middle jiao (when spleen qi is strong, dampness is removed, and healthy qi naturally flourishes). It resolves alcohol toxicity and pufferfish toxicity (The *Beiji Fang* records: mixing the powder with freshly drawn cold water and taking it orally can resolve arsenic poisoning). Excessive consumption can obstruct qi movement. For medicinal use, select beans that are coarse, round, and white; stir-fry them with the skin and grind them. There are also methods involving soaking to remove the skin or using them raw.

Disperse and vent, release the exterior, and relieve irritability.
Bitter in taste to drain the lungs, cold in nature to overcome heat (Chen Cangqi stated: The nature of beans is originally neutral; when stir-fried or boiled hot, they become hot; when made into fermented soybeans [douchi], they become cold). It induces sweating and releases the muscle layer, regulates qi in the middle and lower jiao. It treats headache, irritability, chest fullness, mental restlessness with insomnia, eruption of macules, and vomiting associated with Shanghan (cold damage) (For Shanghan cases involving vomiting, regurgitation, irritability, and fullness, inducing vomiting is appropriate, whereas using purgatives to oppose the pathogen is not. Danchi combined with Gardenia is named Zhizi Chi Tang (Gardenia and Fermented Soybean Decoction), which can induce vomiting for empty irritability); bloody dysentery and wenre (warm malaria) (Li Shizhen stated: Black beans have a neutral nature, but become warm when made into douchi. Since they undergo steaming and fermentation, they possess both ascending and dispersing properties. Combined with scallion, they induce sweating; combined with salt, they induce vomiting; combined with wine, they treat wind disorders; combined with Allium macrostemon, they treat dysentery; combined with garlic, they stop bleeding; when stir-fried, they stop sweating. Meng Shen treated night sweats by stir-frying douchi until fragrant, soaking it in wine, and drinking it. The *Zhouhou Beiji Fang* records: decocting it with scallion whites creates Congchi Tang (Scallion and Fermented Soybean Decoction), used to replace Mahuang Tang for general treatment of Shanghan, releasing the exterior, and also treating ailments caused by excessive alcohol consumption).

Method for preparing Danchi (light fermented soybean): Soak black soybeans in water overnight, rinse thoroughly, and steam until cooked. Spread evenly, cover with mugwort, and wait for a yellow mold layer to appear. Take out, sun-dry, and winnow clean. Moisten with water to achieve appropriate humidity, place in an earthenware jar, and pack tightly. Cover thickly with mulberry leaves and seal with mud. Sun-dry for seven days, take out, expose to the sun for one shichen (two hours), moisten with water again, and return to the jar. Repeat this process seven times, then steam once more, allow the "fire qi" to dissipate, and store in the jar for use.