味苦、辛，寒、大寒，无毒。主百病，除寒热邪气，逐六腑积聚、结固留癖、胃中食
饮热结，破留血、闭绝，停痰痞满，推陈致新。能化七十二种石。炼饵服之，轻身、神仙。
炼之白如银，能寒能热，能滑能涩，能辛能苦，能咸能酸，入地千岁不变，色青白者佳，
黄者伤人，赤者杀人。一名硝石朴。生益州山谷有咸水之阳，采无时。
畏麦句姜。今出益州北部汶山郡、西川、蚕陵二县界，生山崖上，色多青白，亦杂黑斑。
俗
石用之，当烧令汁沸出，状如矾石也。《仙经》惟云硝石能化他石。
今此亦云能化石，疑必相似，可试之。
〔谨案〕此物有二种∶有纵理、缦理，用之无别。白
软者，朴硝苗也，虚软少力，炼为硝石，所得不多，以当硝石，功力大劣也。
味苦、辛，寒、大寒，无毒。主五脏积热、胃胀闭，涤去蓄结饮食，推陈致新，除邪
气，疗五脏十二经脉中百二十疾、暴伤寒、腹中大热，止烦满消渴，利小便及 蚀疮。练之
如膏，久服轻身。天地至神之物，能化成十二种石。一名芒硝。生益州山谷及武都、陇西、
西羌，采无时。
萤火为之使，恶苦参、苦菜，畏女菀。疗病亦与朴硝相似，《仙经》多用此消化诸石，
今无正识别此者。顷来寻访，
犹云与朴硝同山，所以朴硝名硝石朴也，如此则非一种物。先时有人得一种物，其色理与朴
硝大同小异， 如握盐雪
不冰，强烧之，紫青烟起，仍成灰，不
硝乃是练朴硝作之。与后皇
甫说同，并未得核研其验，须试效，当更证记尔。化硝石法，在三十六水方中。陇西属秦州，
在长安西羌中。今宕昌以
此诸山有咸土处皆有之。
〔谨案〕此即芒硝是也。朴硝一名硝石朴，今练粗恶朴硝，淋取汁
煎，练作芒硝，即是硝石。《本
经》一名芒硝，后人更出芒硝条，谬矣。
味苦、辛，性寒、大寒，无毒。主治各种疾病，清除寒热邪气，驱逐六腑中的积聚、结块固着及久留的癖积，消除胃中饮食积滞产生的热结，破除瘀血阻滞，化解停痰引起的痞满，推陈出新。能够溶解七十二种矿石。经过炼制后服用，可以轻身延年，甚至成仙。
炼制后的硝石洁白如银，性质兼具寒热，作用兼具滑涩，味道兼具辛、苦、咸、酸。埋入地下千年不变质，颜色青白色的为佳，黄色的会伤害人体，红色的会致人死亡。又名硝石朴。产于益州山谷中有咸水水源的山坡向阳处，采集没有固定时间。
畏惧麦句姜。现在出产于益州北部的汶山郡、西川、蚕陵二县境内，生长在山崖上，颜色多为青白，也夹杂黑色斑点。俗世使用这种石头时，应当烧至汁液沸腾流出，形态如同矾石一样。《仙经》只说硝石能溶解其他石头。现在这里也说能溶解石头，怀疑两者必定相似，可以试验验证。
【谨案】此物有两种：一种有纵向纹理，一种无纵向纹理（缦理），使用时没有区别。白色柔软的，是朴硝的幼苗，质地虚软且药力不足，将其炼制成硝石，所得不多，用来代替硝石，药效大大劣于真正的硝石。
味苦、辛，性寒、大寒，无毒。主治五脏积热、胃胀闭塞，涤除体内蓄积的饮食糟粕，推陈出新，去除邪气，治疗五脏十二经脉中的一百二十种疾病、突发伤寒、腹部大热，缓解烦闷和消渴症，通利小便以及腐蚀疮疡。炼制后呈膏状，长期服用可轻身延年。这是天地间极灵验的物品，能够化成十二种石头。又名芒硝。产于益州山谷以及武都、陇西、西羌地区，采集没有固定时间。
以萤火为使药，厌恶苦参、苦菜，畏惧女菀。治疗疾病的作用也与朴硝相似，《仙经》多用此物来消化各种石头，现在没有专门辨别区分这两种物质的人。近来寻访查证，仍有人说它们同出一山，所以朴硝被称为“硝石朴”，如此看来并非同一种物质。先前有人得到一种物品，其颜色和纹理与朴硝大体相同而略有差异，像握着盐雪一样不结冰，强行焚烧它，升起紫青色烟雾，最终变成灰烬，并不生成硝石，这其实是将朴硝炼制而成的。这与皇甫的观点相同，但都没有经过严格研究验证其功效，需要试验效果，再加以考证记录。化硝石的方法，记载在三十六水方中。陇西属于秦州，位于长安以西的西羌地区。现在宕昌一带这些山中产咸土的地方都有出产。
【谨案】这就是芒硝。朴硝又名硝石朴，现在将粗糙恶劣的朴硝淋取汁液煎煮，炼制成芒硝，就是硝石。《神农本草经》中称其为芒硝，后人又单独列出芒硝条目，这是错误的。
Bitter, pungent, cold, extremely cold, non-toxic. It treats various diseases, eliminates pathogenic factors of cold and heat, expels accumulations, fixed masses, and lingering癖 (accumulated masses) in the six fu organs, resolves heat accumulation from food and drink retention in the stomach, breaks up retained blood and obstructions, dispels stagnant phlegm causing fullness and痞 (masses), pushes out the old to bring forth the new. It can dissolve seventy-two types of minerals. After refining and taking it, one becomes light-bodied and may attain immortality.
Refined, it is white as silver; its nature can be cold or hot, its action slippery or astringent, its taste pungent, bitter, salty, or sour. It remains unchanged even after being buried in the earth for a thousand years. Those that are greenish-white are superior; those that are yellow harm the body, and those that are red kill. Another name is Xiaoshi Pu (Niter Puxiao). It grows on sunny slopes in valleys with saline water sources in Yizhou. It can be harvested at any time.
It fears Maijujiang (Trollius chinensis). Currently, it is produced in Wenshan Commandery in northern Yizhou, Xichuan, and the borders of Canling County. It grows on mountain cliffs, mostly greenish-white in color, often mixed with black spots. In secular use, this stone should be heated until the juice boils out, resembling Fan Shi (Alum Stone). The *Xian Jing* (Immortal Classic) only states that Xiaoshi (Niter) can dissolve other stones. This text also claims it can dissolve stones, suspecting they must be similar; this can be tested.
[Respectful Note] There are two types of this substance: one has longitudinal grain, the other has diffuse grain (Man Li); there is no difference in their use. The white and soft variety is the sprout of Puxiao (Mirabilite); it is void and soft with weak efficacy. When refined into Xiaoshi (Niter), the yield is low. Using it as a substitute for Xiaoshi results in significantly inferior therapeutic power.
Bitter, pungent, cold, extremely cold, non-toxic. It treats heat accumulation in the five zang organs, gastric distension and obstruction, purges accumulated food retention, pushes out the old to bring forth the new, eliminates pathogenic factors, treats one hundred and twenty diseases within the five zang organs and twelve regular meridians, sudden Shanghan (Cold Damage), severe abdominal heat, relieves vexation, fullness, and Xiao Ke (Wasting-Thirst syndrome), promotes urination, and cauterizes sores. Refined into a paste, long-term consumption lightens the body. It is a divine object of heaven and earth, capable of transforming twelve types of minerals. Another name is Mangxiao (Natrii Sulfas). It grows in the valleys of Yizhou, as well as in Wudu, Longxi, and among the Western Qiang people. It can be harvested at any time.
Yinghuo (Firefly) serves as its guiding herb. It dislikes Kushen (Sophorae Radix) and Kucai (Amaranthus), and fears Nuwan (Polygala japonica). Its therapeutic effects are similar to Puxiao. The *Xian Jing* often uses this substance to digest various minerals. Currently, there are no experts who specifically distinguish between these substances. Recent inquiries suggest they grow on the same mountains, hence Puxiao is called "Xiaoshi Pu," implying they are not the same substance. Previously, someone obtained a substance whose color and texture were largely similar but slightly different from Puxiao; it felt like holding salt snow without freezing. When forcibly burned, it rose with purple-blue smoke and turned to ash, not forming Niter. This was actually made by refining Puxiao. This aligns with Huangfu's statement, but neither has been rigorously verified through experimentation. Further testing and documentation are required. The method for refining Niter is found in the Thirty-Six Waters Formula. Longxi belongs to Qinzhou, located west of Chang'an among the Western Qiang. Currently, it is found in places with saline soil in the mountains of Dangchang.
[Respectful Note] This is Mangxiao (Natrii Sulfas). Puxiao is also known as Xiaoshi Pu. By leaching coarse and impure Puxiao to extract the juice and boiling it down, one refines it into Mangxiao, which is essentially Xiaoshi (Niter). The *Shennong Benjing* lists it under the name Mangxiao; later authors created a separate entry for Mangxiao, which is erroneous.