（《拾遗》）
【主治】卒心痛，疰忤恶气，温酒服一钱（藏器）。
（《拾遗》）
【主治】丈夫阴囊湿痒，及阴汗，细末扑之（藏器）。
（《别录》下品）
【气味】甘，温，无毒。
【主治】下部疮，脱肛（《别录》）。止泄痢霍乱烦闷（藏器）。温疟，点目去翳。同蚬壳
为末，敷豌豆疮（甄权）。疗小儿风脐（弘景）。摩干、湿二癣，极效（苏恭）。
【发明】弘景曰∶此屋之东壁上土也，常先见日故尔。又可除油垢衣，胜锻石、滑石。
藏器曰∶取其向阳久干也。
宗 曰∶久干之说不然。盖东壁先得太阳真火烘炙，故治瘟疫。初出少火之气壮，及当
午则壮火之气衰，故不用南壁而用东壁。
时珍曰∶昔一女，忽嗜河中污泥，日食数碗。玉田隐者以壁间败土调水饮之，遂愈。又
凡脾胃湿多，吐泻霍乱者，以东壁土，新汲水搅化，澄清服之，即止。盖脾主土，喜燥而恶
湿，故取太阳真火所照之土，引真火生发之气，补土而胜湿，则吐泻自止也。《岭南方》治
瘴疟香椿散内用南壁土，近方治反胃呕吐用西壁土者，或取太阳离火所照之气，或取西方收
敛之气，然皆不过借气补脾胃也。
【附方】旧三，新九。
急心痛∶五十年陈壁土、枯矾各二钱。为末，蜜丸，艾汤服。（《集玄方》）
霍乱烦闷∶向阳壁土，煮汁服。（《圣济录》）
药毒烦闷欲死者。东壁土调水三升，顿饮之。（《肘后方》）
解乌头毒∶不拘川乌、草乌毒。用多年陈壁土，泡汤服之。冷水亦可。（《通变要法》）
六畜肉毒∶东壁土末，水服一钱，即安。（《集玄方》）
目中翳膜∶东壁土细末，日点之，泪出佳。（《肘后方》）
肛门凸出∶故屋东壁上土一升，研末，以长皂荚挹末粉之，仍炙皂荚，更互熨之。（《外
台秘要》）
痱子瘙痒∶干壁土末敷之，随手愈。（《普济方》）
耳疮唇疮∶东壁土和胡粉敷之。（《救急方》）
破经年，脓水不绝。用百年茅屋厨中壁土为末，入轻粉调敷，半月即干愈。（《永类
方》）
诸般恶疮∶拔毒散∶东墙上土、大黄等分。为末，用无根井华水调搽，干再上。（《瑞
竹堂方》）
发背痈疖多年∶烟熏壁土、黄柏等分，为末。姜汁拌调摊贴之，更以茅香汤调服一钱匕。
（《经验方》）
(From *Bencao Shiyi* [Supplement to Materia Medica])
【Indications】Sudden heart pain, and Zhuwu evil qi (a sudden discomfort caused by external pathogens or malevolent influences), taken with warm wine, one qian (Sun Zangqi).
(From *Bencao Shiyi* [Supplement to Materia Medica])
【Indications】Dampness and itching of the male scrotum, as well as sweating in the genital area, applied as a fine powder dusted onto the affected area (Sun Zangqi).
(From *Mingyi Bielu* [Record of Famous Physicians], Lower Grade)
【Flavor and Nature】Sweet, warm, non-toxic.
【Indications】Sores in the lower body, rectal prolapse (*Mingyi Bielu*). Stops diarrhea, dysentery, cholera-like syndrome, and restlessness (Sun Zangqi). Treats warm malaria, removes corneal opacity when instilled into the eyes. Mixed with clam shell powder and applied to treat pox-like sores (Zhen Quan). Treats infantile wind umbilicus (Tao Hongjing). Rubbed on dry tinea and wet tinea, extremely effective (Su Gong).
【Analysis and Clarification】Tao Hongjing stated: This is earth from the east wall of a house, because it is usually the first to see the sun. It can also remove oil stains from clothes, superior to calcined stone and talc.
Sun Zangqi stated: Take advantage of its sunny and long-dried nature.
Chen Cheng stated: The explanation of "long-dried" is incorrect. It is likely that the east wall is first baked by the true fire of the sun, thus treating epidemics. In the early morning, the Qi of Shaohuo (Lesser Fire) is strong, but by noon, the Qi of Zhuanghuo (Greater Fire) declines; therefore, the south wall is not used, but the east wall is.
Li Shizhen stated: In the past, a woman suddenly craved eating mud from rivers, consuming several bowls daily. A hermit in Yutian gave her water mixed with old earth from the wall, and she recovered. Furthermore, for those with excessive dampness in the spleen and stomach, presenting with vomiting, diarrhea, and cholera-like syndrome, using earth from the east wall mixed with fresh well water, stirred until clarified and then drunk, stops symptoms immediately. This is because the spleen belongs to Earth, prefers dryness, and dislikes dampness. Thus, taking earth illuminated by the true fire of the sun guides the generating Qi of the true fire to tonify Earth and overcome dampness, causing vomiting and diarrhea to cease naturally. In *Lingnan Fang*, southern wall earth is used in the Xiangchun Powder to treat malarial fevers due to miasma; recent prescriptions use western wall earth to treat regurgitation and vomiting. These may be borrowing the Qi of the Li Fire (Sun) or the condensing Qi of the West, but all merely borrow Qi to tonify the spleen and stomach.
【Attached Prescriptions】Three old formulas, nine new formulas.
Sudden Heart Pain: Fifty-year-old aged wall earth and alum, each two qian. Ground into powder, formed into pills with honey, taken with mugwort decoction. (*Jixuan Fang*)
Cholera-like Syndrome with Restlessness: Wall earth facing the sun, boiled in water and the juice drunk. (*Shengji Lu*)
Drug Poisoning with Severe Restlessness: Three sheng of water mixed with east wall earth, drunk in one dose. (*Zhouhou Fang*)
Detoxifying Aconite Poison: Regardless of Sichuan aconite or grass aconite poisoning, use many-year-old aged wall earth, soaked in water and drunk. Cold water is also acceptable. (*Tongbian Yaofa*)
Poisoning from Meat of Six Livestock: East wall earth powder, taken with water, one qian, brings immediate relief. (*Jixuan Fang*)
Corneal Opacity in Eyes: Fine powder of east wall earth, instilled into the eyes daily; tearing is desirable. (*Zhouhou Fang*)
Rectal Prolapse: One sheng of earth from the east wall of an old house, ground into powder. Use a long gleditsia fruit to dip the powder and apply it; simultaneously roast the gleditsia fruit and alternate applying heat to the area. (*Waitai Miyao*)
Prickly Heat Itching: Apply powder of dry wall earth; heals instantly. (*Puji Fang*)
Ear Sores and Lip Sores: East wall earth mixed with lead white powder and applied. (*Jiuji Fang*)
Ulcers Persisting for Years with Continuous Pus: Use earth from the kitchen walls of a century-old thatched-roof house, ground into powder, mixed with calomel, and applied; dries and heals within half a month. (*Yonglei Fang*)
Various Malignant Sores: Baidu San [Detoxification Powder]: Equal parts of earth from the east wall and rhubarb. Ground into powder, mixed with unrooted well water (first drawn water from a well before sunrise) for topical application; reapply when dry. (*Ruizhutang Fang*)
Long-standing Carbuncles and Boils on the Back: Equal parts of smoke-cured wall earth and phellodendron bark. Ground into powder, mixed with ginger juice and applied as a plaster; additionally, take one qianbi mixed with mugwort fragrance decoction orally. (*Jingyan Fang*)