诸家只解灰而不解冬，亦其阙也。诸灰一烘而成，惟冬灰，则经三四月方彻炉。灰既
晓夕烧灼，其力得不全燥烈乎？而又体益重。今一 而成者体轻，盖火力劣，故不及冬灰耳
。若古紧面少容方中，用九烧益母灰，盖取此义。如或诸方中用桑灰，自合依本法。既用冬
灰，则须尔。《唐本》注云∶冬灰本是藜灰，未知别有何说。又汤火灼，以饼炉中灰细罗，
脂麻油调，羽扫，不得着水，仍避风。
妇人血露，蚕沙一两，炒伏龙肝半两，阿胶一两，同为末，温酒调，空肚服二三钱
，以知为度。本条中有东壁土，陈藏器云∶取其东壁土，久干也。今详之∶南壁土，亦向阳
久干也，何不取？盖东壁常先得晓日烘炙。日者太阳真火，故治瘟疟。或曰∶何不取午盛之
时南壁土，而取日初出东壁土者，何也？火生之时，其气壮。故《素问》云∶少火之气壮。
及其当午之时，则壮火之气衰，故不取，实用此义。或曰∶何以知日者太阳真火？以水精珠
，或心凹铜鉴，向日射之，以艾承接其光聚处，火出，故知之。
半天河水，一水也。然用水之义有数种，种各有理。如半天河水，在上，天泽水
也。故治心病、鬼疰、狂、邪气、恶毒。腊雪水，大寒水也，故解一切毒，治天行时气、
温疫、热痫、丹石发、酒后暴热、黄胆。井华水，清冷澄澈水也，故通九窍，洗目肤翳，及
酒
后热痢。后世又用东流水者，取其快顺疾速，通关下膈也。倒流水，取其回旋留止，上而不
下也。
各家本草只解释了“灰”的含义，却没有解释“冬”字的含义，这是他们的疏漏。一般的草木灰只需烘烤一次即可制成，只有冬灰需要经过三四个月的持续烧炼才能完成。因为灰在白天黑夜都受到火力的灼烧，其药力怎能不变得极其燥烈呢？而且它的质地也变得更加沉重。如今那些一次性烧制而成的灰质地较轻，大概是火力不足，所以药效不如冬灰。如果在古方中遇到类似制作紧面时少容方里使用九烧益母草灰的情况，大概也是取这种深烧厚制的意义。如果其他方剂中使用桑木灰，自然应当遵循本来的方法。既然使用了冬灰，就必须按照上述方法制作。《新修本草》（唐本草）的注释说：冬灰本来是用藜草烧成的灰，不知道是否还有其他的说法。另外，对于汤火烫伤，可以用饼炉中的细灰经过细罗筛过，用芝麻油调和，用羽毛扫涂患处，注意不要沾水，并且要避风。
治疗妇女经血淋漓不尽，用蚕沙一两，炒过的伏龙肝半两，阿胶一两，共同研成细末，用温酒调服，空腹服用二三钱，以见效为度。这一条原文中还提到了东壁土，陈藏器说：选用东壁土，是因为它干燥得久。现在我仔细考察：南面的墙壁土壤，也是向阳且干燥得久的，为什么不选取呢？大概是因为东面的墙壁常常最先接受早晨阳光的烘烤。太阳是真正的真火，所以能治疗瘟疫和疟疾。有人问：为什么不选取中午时分阳光最盛时的南壁土，而要选取日出时东面的墙壁土呢？这是因为在火气生发的时候，其气势旺盛。所以《素问》说：少火之气壮盛。等到正午时分，壮火的气势就会衰退，所以不选取，实际上就是运用了这一道理。又有人问：怎么知道太阳是真火呢？用水晶珠，或者中间凹陷的铜镜，对着太阳照射，用艾草承接光线聚集的地方，火就出来了，因此知道了这一点。
半天河水，本质上也是一种水。然而用水的道理有多种情况，每种情况都有其特定的原理。比如半天河水，位于高处，属于天降的泽水。所以用于治疗心病、鬼疰（一种慢性消耗性传染病）、狂症、邪气侵袭、恶毒疮疡。腊雪水，是大寒之水，所以能解各种毒素，治疗流行性时气病、温疫、热性癫痫、丹石药发作引起的发热、酒后突发高热、黄疸。井华水（清晨第一次打出的井水），是清冷澄澈的水，所以能通利九窍，清洗眼目肤表的翳障，以及酒后热痢。后世又使用东流水，是取其快速顺畅、疾速流动的特性，用来通关开窍、下膈消积。倒流水，是取其回旋停留、向上而不向下的特性。
Various pharmacopoeias only explain the term "ash" (Hui, plant ash) but fail to explain "winter" (Dong), which is their omission. Most ashes are produced by a single roasting process, whereas winter ash requires three or four months of continuous burning in the furnace. Since the ash is subjected to fire's scorching heat day and night, how can its potency not become extremely drying and acrid? Furthermore, its physical body becomes heavier. Ashes produced in a single firing are lighter in texture, likely due to insufficient fire power, thus lacking the efficacy of winter ash. For instance, in ancient recipes such as the "Shao Rong Fang" for making tight dough, using nine-times roasted motherwort ash (Yimucao Hui) seems to adopt this principle of deep roasting. If mulberry ash (Sang Hui) is used in other prescriptions, one should naturally follow the original method. However, if winter ash is specified, it must be prepared as described above. The commentary in the *Xinxiu Bencao* (Tang Bencao) states: "Winter ash is originally made from burning chenopodium (Li grass); it is unknown if there are other explanations." Additionally, for burns and scalds, fine ash from a cake-baking furnace can be sifted through a fine mesh, mixed with sesame oil (Zhimayou), applied with a feather brush, avoiding water contact, and keeping the area away from wind.
To treat menorrhagia (blood leakage) in women, use 1 liang of silkworm sand (Can Sha), 0.5 liang of stir-fried Fulonggan (Dragon's House Liver, i.e., sediment from clay cooking stoves), and 1 liang of Ejiao (Donkey-hide gelatin). Grind them together into a fine powder. Take 2-3 qian with warm wine on an empty stomach, adjusting the dosage until the desired effect is achieved. This entry also mentions Dongbitu (East Wall Soil). Chen Zangqi stated that east wall soil is chosen because it dries out over a long period. Upon closer examination: south wall soil is also sun-exposed and dries thoroughly; why not choose it? It is likely because the east wall receives the morning sun's heating first. The Sun is the true fire of Taiyang (Greater Yang), hence it treats epidemic fevers (Wen) and malaria (Nue). One might ask: Why not choose south wall soil at noon when the sun is strongest, but instead choose east wall soil at sunrise? This is because when fire energy is generating, its qi is vigorous. Thus, the *Suwen* states: "The qi of mild fire is vigorous." By noon, the qi of excessive fire declines, so it is not chosen; this practice actually applies this principle. Another question arises: How do we know the Sun is true fire? By using a crystal lens or a concave bronze mirror to focus sunlight onto mugwort (Ai) placed at the focal point, causing fire to ignite, thereby confirming this knowledge.
Bantianhe Shui (Halfway River Water) is essentially just water. However, the rationale for using different types of water varies, each having its own theoretical basis. Bantianhe Shui, being located high up, belongs to heavenly dew/rainwater. Therefore, it is used to treat Heart diseases, Guizhu (ghostly affections/chronic wasting diseases), mania (Kuang), pathogenic evil qi, and malignant toxins. Laxue Shui (Snow Water collected in the twelfth lunar month) is extremely cold water; thus, it resolves various toxins and treats epidemic seasonal diseases (Tianxing Shiqi), warm epidemics (Wenyi), heat-type epilepsy (Re Xian), flare-ups caused by Danchi (mineral pills), sudden post-alcohol heat, and jaundice (Dan Huang). Jinghua Shui (Well water drawn at dawn) is clear, cold, and transparent water; therefore, it unblocks the nine orifices, washes away ocular and cutaneous opacities (Yi), and treats heat-dysentery following alcohol consumption. Later generations also used Dongliushui (East-flowing water), taking advantage of its swift and smooth flow to open blockages and descend stagnation in the diaphragm. Daoliushui (Backward-flowing water) is used for its swirling and stagnant nature, moving upward rather than downward.