（《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》）
（出自《本草拾遗》）
【主治】突发心痛，以及疰忤恶气（指由外邪或鬼祟之气引起的突发性不适），用温酒送服一钱（孙藏器）。
（出自《本草拾遗》）
【主治】男子阴囊潮湿瘙痒，以及阴部出汗，将药研成细末扑撒患处（孙藏器）。
（出自《名医别录》下品）
【气味】味甘，性温，无毒。
【主治】下部疮疡，脱肛（《名医别录》）。止泄泻、痢疾、霍乱及烦闷（孙藏器）。治疗温疟，点眼去除翳膜。与蚬壳研为末，敷治豌豆疮（甄权）。治疗小儿风脐（陶弘景）。摩擦干癣和湿癣，效果极佳（苏恭）。
【发明】陶弘景说：这是房屋东墙壁上的土，因为常先见到太阳的缘故。还可以用来去除衣服上的油垢，胜过锻石和滑石。
孙藏器说：取它向阳且久干的特点。
陈承说：关于“久干”的说法不对。大概是东壁先接受太阳真火的烘烤，所以能治疗瘟疫。初升时少火之气壮盛，到了中午则壮火之气衰退，所以不用南壁而用东壁。
李时珍说：从前有个女子，突然嗜好食用河中的污泥，每天吃几碗。玉田的一位隐士用墙壁间陈旧的泥土调水给她喝，病就好了。另外，凡是脾胃湿气重，出现呕吐、泄泻、霍乱的人，用东壁土，加入新打的井水搅拌化开，澄清后服用，症状立即停止。大概是因为脾属土，喜欢干燥而厌恶湿气，所以选取被太阳真火照射过的土，引导真火生发之气，补益脾土以战胜湿气，那么吐泻自然停止。《岭南方》治疗瘴疟的香椿散中使用了南壁土，近方治疗反胃呕吐使用了西壁土，或许是取太阳离火所照之气，或是取西方收敛之气，但都不过是借气来补益脾胃罢了。
【附方】旧方三个，新方九个。
急心痛：五十年陈旧的壁土、枯矾各二钱。研为末，蜜丸，艾叶汤送服。（《集玄方》）
霍乱烦闷：向阳的壁土，煮汁服用。（《圣济录》）
药物中毒烦闷欲死：东壁土调水三升，一次性饮下。（《肘后方》）
解乌头毒：不拘泥于是川乌还是草乌中毒。用多年陈旧的壁土，泡汤服用。冷水也可以。（《通变要法》）
六畜肉毒：东壁土末，水送服一钱，即安。（《集玄方》）
目中翳膜：东壁土细末，每日点眼，流泪为佳。（《肘后方》）
肛门凸出：老房子东壁上土一升，研末，用长皂荚蘸取粉末扑撒，同时炙烤皂荚，交替熨烫患处。（《外台秘要》）
痱子瘙痒：干壁土末敷之，随手痊愈。（《普济方》）
耳疮唇疮：东壁土调和胡粉敷之。（《救急方》）
破溃经年，脓水不绝。用百年茅屋厨房中的壁土为末，加入轻粉调匀敷贴，半月即干燥痊愈。（《永类方》）
诸般恶疮：拔毒散：东墙上的土、大黄等分。研为末，用无根井华水调搽，干了再上药。（《瑞竹堂方》）
发背痈疖多年：烟熏壁土、黄柏等分，研为末。姜汁拌调摊贴患处，再用茅香汤调服一钱匕。（《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*)