辛苦微咸。大热毒烈。治伤冷霍乱吐利。心腹病痛。破积散坚。不宜轻服。又名火硝、
焰硝
。（得火则焰、故名、朴硝阴寒、属水下走、能荡涤积滞、硝石大热、属火上升、能破积散
坚、 制礞石、则除积滞痰饮、盖礞石性寒而降、硝石性热而升、一升一降、一阴一阳、此
制方之妙也。）以上卤石类。
天水类 地水类
升阳。
甘平。宜煎中气不足、清阳不升之药。（虞抟医学正传云∶其性始、是春初生发之气、
古方
妇人无子、立春日、夫妇各饮一杯、还房有孕、亦取其资始、发育万物之义也。）
升阳。
甘平。宜煎发散及补中益气药。并浸造诸风及脾胃虚弱诸丹丸。（自立春至谷雨水、轻
清上
行补中、而治阳气下陷诸证、最有益于脾胃、宜多贮之。
有毒。坏豆麦桑叶。（蚕食之、多不熟。）造药、酿酒醋。一应食物。皆易败坏。人饮之
亦生
脾胃疾。咸雨。（小满节气前后、逢癸日有雨、为咸雨、其毒尤甚。）
有毒。甚消伐。洗疮疥。灭瘢痕。入酱易熟。（藏器曰∶江淮以南、地气卑湿、五月上
旬连
下旬尤甚、过此节以后、皆须曝书画、梅雨沾衣、便腐黑、浣垢如灰汁、有异他水、但以梅
叶汤洗之、乃脱、时珍曰∶梅雨或作霉雨、言其沾衣及物、皆生黑霉也、芒种后逢壬为入梅
、小暑后逢壬为出梅、此湿热之气、郁遏熏蒸、酿为霏雨、人受其气则生病、物受其气则生
霉、故此水不可以造酒醋。）
味辛苦，微带咸味。药性大热且毒性猛烈。用于治疗因受寒引起的霍乱导致的呕吐和腹泻，以及心腹部的疼痛病症。具有破除积滞、消散坚块的功效。不宜轻易服用。又名火硝、焰硝。（因为遇到火会产生火焰，所以得名。朴硝性质阴寒，属性为水，趋向于下行，能够荡涤体内的积滞；硝石性质大热，属性为火，趋向于上升，能够破除积滞、消散坚块。用硝石来炮制礞石，可以消除积滞和痰饮。这是因为礞石性质寒凉而沉降，硝石性质温热而升散，一升一降，一阴一阳，这是制作方剂的精妙之处。）以上属于卤石类。
天水类、地水类。
具有提升阳气的作用。
味甘，性平。适宜用于煎煮治疗中气不足、清阳之气不能上升的药物。（虞抟在《医学正传》中说：它的性质始于春初生发之气。古方记载，妇女不孕，在立春之日，夫妇各喝一杯雨水，回房同房后容易受孕，也是取其资助起始、发育万物的意义。）
具有提升阳气的作用。
味甘，性平。适宜用于煎煮发散表邪及补中益气的药物。并可用于浸泡制作治疗各种风病及脾胃虚弱等各种丹丸。（从立春日到谷雨节气期间，雨水轻清上行，能补益中气，治疗阳气下陷的各种证候，最有益于脾胃，宜多储存。
有毒。会破坏豆类、麦类和桑叶。（蚕食用后，吐出的丝往往不成熟。）用于制药、酿酒、酿醋时，所有食物都容易败坏。人饮用后也会产生脾胃疾病。咸雨。（在小满节气前后，逢癸日下雨，称为咸雨，其毒性尤其严重。）
有毒。消伐作用很强。用于清洗疮疥。能消除瘢痕。加入酱中能使其易熟。（藏器说：江淮以南地区，地势低洼潮湿，五月上旬至下旬尤为严重。过了这个节气以后，都必须晾晒书画。梅雨沾湿衣服，就会腐烂变黑，洗涤污垢如同灰汁一样，与其他水不同，只用梅叶汤清洗，才能脱落。李时珍说：梅雨有时写作霉雨，意思是它沾湿衣物和物品，都会生出黑霉。芒种之后逢壬日为入梅，小暑之后逢壬日为出梅。这是湿热之气，郁结遏制，熏蒸酝酿成霏雨，人受到这种气就会生病，物体受到这种气就会生霉，所以这种水不可以用来酿造酒醋。）
Bitter, pungent, and slightly salty. It possesses great heat toxicity and is fierce in nature. It treats cold-injury Huoluan (cholera-like syndrome with vomiting and diarrhea), pain in the heart and abdomen. It breaks up accumulations and dissipates hardness. It should not be taken lightly. Also known as Huoxiao (Fire Niter) or Yanxiao (Flame Niter). (Because it produces flames when exposed to fire, hence the name. Puxiao (Mirabilite) is Yin-cold in nature, belongs to Water, tends to descend, and can scour away stagnations; Xiaoshi (Niter) is greatly hot in nature, belongs to Fire, tends to ascend, and can break up accumulations and dissipate hardness. When used to process Mengshi (Lingyun Stone), it eliminates stagnations and phlegm-fluids. This is because Mengshi is cold in nature and descending, while Xiaoshi is hot in nature and ascending; one ascends and one descends, one is Yin and one is Yang. This is the subtlety of formula preparation.) The above belong to the Halite category.
Heavenly Water category, Earthly Water category.
[Function:] Raises Yang Qi.
Sweet and neutral. Suitable for decocting herbs that treat insufficiency of Middle Qi and failure of Clear Yang to ascend. (Yu Tuan in *Yixue Zhengzhuan* states: Its nature begins with the generating Qi of early spring. Ancient prescriptions record that for women with infertility, on the day of Lichun (Start of Spring), both husband and wife drink a cup of this water, and upon returning to the bedroom, pregnancy may occur. This also derives from its meaning of aiding the beginning and nurturing all things.)
[Function:] Raises Yang Qi.
Sweet and neutral. Suitable for decocting dispersing and Middle-Boosting Qi tonifying herbs. Also suitable for soaking and preparing various pills and electuaries for treating wind disorders and Spleen-Stomach deficiency. (From Lichun (Start of Spring) to Guyu (Grain Rain), the rain is light and clear, ascending to nourish the Middle and treat syndromes of sinking Yang Qi. It is most beneficial to the Spleen and Stomach and should be stored in large quantities.
Toxic. Damages beans, wheat, and mulberry leaves. (Silkworms feeding on it produce silk that often does not mature properly.) Used in medicine making, brewing wine, and making vinegar. All foods are prone to spoilage. Drinking it also causes Spleen-Stomach diseases. Xianyu (Salty Rain). (Rain falling on Gui days around the Xiaoman (Grain Full) solar term is called Salty Rain, and its toxicity is particularly severe.)
Toxic. Has strong dissolving and attacking properties. Used to wash sores and scabies. Eliminates scars. Makes sauce cook faster. (Zangqi says: In the regions south of the Jianghuai rivers, the terrain is low and damp. This condition is especially severe from early to late May. After this solar term, calligraphy and paintings must be sun-dried. If plum rain wets clothes, they rot and turn black; washing stains resembles using lye water, differing from other waters. Only by washing with plum leaf soup can they be removed. Li Shizhen says: Plum rain is sometimes written as Meiyu (Mold Rain), indicating that it causes clothes and objects to grow black mold. Ren days after Mangzhong (Grain in Ear) mark the start of the rainy season (Ru Mei); Ren days after Xiaoshu (Minor Heat) mark the end (Chu Mei). This is humid and hot Qi, constrained and steaming, brewing into drizzle. Humans contracting this Qi fall ill; objects contracting this Qi grow mold. Therefore, this water cannot be used to brew wine or vinegar.)