Library

[Puo Xiao (Natrii Sulfas)]
Taste: bitter, pungent. Nature: cold or very cold. Toxicity: non-toxic. Indications: treats various diseases, eliminates pathogenic factors of cold and heat, expels accumulations in the six fu organs (Stomach, Gallbladder, Small Intestine, Large Intestine, Bladder, Sanjiao), breaks up solid masses and long-standing fixed deposits, clears heat consolidations in the stomach caused by food and drink, breaks stagnant blood, treats obstructions and blockages, removes retained phlegm and fullness, pushes out the old to bring forth the new. Can dissolve seventy-two types of minerals. When refined and taken, it lightens the body and leads to immortality. After refining, it is white as silver; its nature can be both cold and hot, its action both slippery and astringent, its taste both pungent, bitter, salty, and sour. It remains unchanged 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. Also known as Xiaoshi Pu (Nitrum Pu). Grows in the valleys of Yizhou where saline water flows on sunny slopes. Harvested at any time. Incompatible with Maijujiang.
Currently produced in Wenshan Commandery in northern Yizhou, Xichuan, and the borders of Canling County. It grows on mountain cliffs, mostly greenish-white, often mixed with black spots. People select the white and soft varieties to use as Xiaoshi (Sal Niter). It should be heated until the liquid boils out, resembling Fan Shi (Alum Stone). The *Xian Jing* (Scripture of Immortals) states only that Xiaoshi can dissolve other stones. This text also says it can dissolve stones; it is suspected that they must be similar, and this can be tested. (From *Xinxiu Bencao* page 16, *Daguan Bencao* Vol. 3, *Zhenghe Bencao* page 87)

[Xiaoshi (Sal Niter)]
Taste: bitter, pungent. Nature: cold or very cold. Toxicity: non-toxic. Indications: treats accumulated heat in the five zang organs, gastric distension and obstruction, cleanses and removes accumulated food stagnation, pushes out the old to bring forth the new, eliminates pathogenic factors, treats one hundred and twenty diseases in the five zang organs and twelve regular meridians, sudden attack of cold damage, severe internal abdominal heat, stops irritability, fullness, and xiaoke (wasting-thirst syndrome), promotes urination, and erodes ulcers. Refined into a paste. Long-term use lightens the body. It is a divine substance of heaven and earth, capable of transforming twelve types of minerals. Also known as Mangxiao (Mirabilite). Grows in the valleys of Yizhou, as well as Wudu, Longxi, and among the Western Qiang. Harvested at any time. (Yinghuo [Firefly] acts as its guide drug; incompatible with Kushen [Sophorae Radix] and Kucail [Amaranthi Caulis]; fears Nuwan [Anemones Radix].)
Its therapeutic effects are similar to Pu Xiao. The *Xian Jing* uses this substance extensively to digest various minerals. Currently, there is no standard method to distinguish this specific substance. Recent inquiries suggest it comes from the same mountains as Pu Xiao, hence Pu Xiao 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 Pu Xiao. It felt like holding salt snow but was not cold. When forcibly burned, it raised purple-green smoke and turned to ash. Unlike Pu Xiao, it did not boil vigorously; it was said to be true Xiaoshi. This text also states it is named Mangxiao, whereas current Mangxiao is made by refining Pu Xiao. This aligns with the later statement by Huangfu Mi, but neither has been rigorously verified. Efficacy must be tested to further confirm and record. The method for dissolving Xiaoshi is found in the Thirty-Six Waters formulas. Longxi belongs to Qinzhou, located west of Chang'an among the Western Qiang. It is currently found in areas with saline soil in the mountains north of Dangchang. (From *Xinxiu Bencao* page 18, *Daguan Bencao* Vol. 3, *Zhenghe Bencao* page 85)