消硝通生于卤地。状似末盐。见水即消。又能消化诸物。故谓之消。此种本体未化。
故谓之朴。凡牛马诸皮。须此治熟。俗又有盐硝皮硝之称。（志）硝有三品。生西蜀者川硝。
最胜。生河东者盐硝。次之。生河北青齐者。俗呼土硝。斥卤之地。人多刮扫煎汁。经宿结
成。犹有沙土猥杂。其色黄白。别录云。朴硝黄者伤人。赤者杀人。须再以水煎化。澄去渣
脚。入萝卜数枚同煮熟。去萝卜。倾入盆中。经宿则结成白硝。如冰如蜡。故呼盆硝。齐卫
之硝则底多。上面生细芒如锋。别录所谓芒硝是也。川晋之硝则底少。面上生牙如圭。角作
六棱。洞澈可爱。嘉 所谓马牙硝是也。状如白石英。又名英硝。二硝之底。则通名朴硝也
。取芒硝英硝。再三以萝卜煎炼。去咸味。即为甜硝。（中风活命金丹中用之）以二硝置风
日中。吹去水气。则轻白如粉。为风化硝。以朴硝芒硝英硝同甘草煎过。鼎罐升 。则为元
明粉。唐宋诸人不知诸硝皆是一物。但有精粗之异。谬猜乱度。殊无指归。（濒湖）
味苦咸。气寒。有小毒。朴硝澄下。硝之粗者也。其质重浊。芒硝牙硝结于上。硝之精
者也。其质清明。甜硝风化硝则又芒硝牙硝之去气味而甘缓轻爽者。故朴硝止可施于卤莽之
人。及敷涂之药。若汤散服饵。必须芒硝牙硝为佳。仲景伤寒论只用芒硝。不用朴硝。正此
主治。与芒硝不远。惟本经朴硝所治者。六腑耳。第如承气入
胃。皆以芒硝。则朴硝不必更列可也。
消硝自然生长在盐碱之地。形状像细盐。遇水即溶解。又能消化各种物体。所以称为“消”。这种物质本体未经提炼变化，所以称为“朴”。凡是牛马等皮革，必须用此物处理才能熟化。民间又有盐硝、皮硝的称呼。（《本草拾遗》记载）硝分为三种：产于西蜀的叫川硝，品质最好；产于河东的叫盐硝，品质次之；产于河北青齐地区的叫土硝，是当地人在盐碱地上刮取泥土煎汁，过夜后结成，其中还混杂着沙土杂质，颜色黄白。《名医别录》说，黄色的朴硝伤人，红色的朴硝杀人。需要再次用水煎煮熔化，澄清去除沉淀渣滓，放入几枚萝卜同煮至熟，取出萝卜，倒入盆中，过夜后结成白色的硝，像冰像蜡，所以称为盆硝。齐卫地区产的硝底部多，上面生成细小的芒刺如锋刃，这就是《名医别录》所说的芒硝。川晋地区产的硝底部少，面上生成如圭玉般的晶牙，呈六角棱形，通透可爱，这是李时珍（嘉谟）所说的马牙硝。形状像白石英，又名英硝。这两种硝的底部沉淀物，通称为朴硝。将芒硝、英硝再三用萝卜煎炼，去除咸味，就得到甜硝。（中风活命金丹中使用它）。将两种硝放在风日下吹干水分，变得轻白如粉末，称为风化硝。将朴硝、芒硝、英硝与甘草共同煎煮，经过蒸馏升华，则成为元明粉。唐宋时期的人们不知道各种硝都是一种物质，只是有精细和粗糙的区别，胡乱猜测推断，毫无定论。（李时珍语）
味道苦、咸。性质寒。有小毒。朴硝沉淀在下部，是硝中粗糙者。其质地重浊。芒硝、牙硝结晶于上部，是硝中精细者。其质地清明。甜硝、风化硝则是去除了芒硝、牙硝的气味而变得甘缓轻爽的物质。所以朴硝只可施用于粗鲁之人，或作为外敷涂药。如果是汤剂散剂内服，必须以芒硝、牙硝为佳。张仲景《伤寒论》只用芒硝，不用朴硝，正是基于这一主治原则。它与芒硝的主治功效相近。只有《神农本草经》中朴硝所治疗的病症，局限于六腑。例如承气汤入胃，都用芒硝，那么朴硝不必再单独列出也可以。
Xiaoxiao (Sodium Sulfate, refined) naturally grows in saline-alkali lands. Its appearance resembles fine salt. It dissolves immediately upon contact with water and can also digest various substances; hence it is called "Xiao" (Dissolving). Since this substance remains in its unrefined, original state, it is called "Pu" (Simple/Rough). All cattle and horse hides must be treated with this to become cured. In common parlance, it is also known as Yanxiao (Salt Niter) or Pixiao (Hide Niter). (*Zhi*) There are three grades of Xiao: that produced in Western Shu is called Chuanxiao (Sichuan Niter), which is of the highest quality; that from Hedong is called Yanxiao, which is second best; and that from Qing and Qi in Hebei is commonly called Tuxiao (Earth Niter). People in saline-alkali regions often scrape the soil, boil the juice, and let it stand overnight to crystallize. This still contains impurities like sand and dirt, appearing yellowish-white. *Bielu* states that yellow Pu Xiao harms people, while red Pu Xiao kills them. It must be re-boiled in water until dissolved, clarified to remove sediment, boiled together with several radishes until cooked, the radishes removed, and then poured into a basin. After standing overnight, it crystallizes into white Xiao, resembling ice or wax, thus called Penxiao (Basin Niter). The Xiao from Qi and Wei has much base material, with fine sharp crystals forming on top, which is what *Bielu* refers to as Mangxiao (Mirabilite). The Xiao from Chuan and Jin has less base, with crystal teeth forming on the surface like jade tablets, shaped into six-prism angles, transparent and lovely; this is what Li Shizhen (Jiamo) calls Mayaxiao (Horse-tooth Niter). Resembling white quartz, it is also named Yingxiao. The base precipitate of these two types of Xiao is collectively called Pu Xiao. By repeatedly boiling Mang Xiao and Ying Xiao with radishes to remove the salty taste, one obtains Tianxiao (Sweet Niter). (Used in *Zhongfeng Huoming Jindan*). Placing these two types of Xiao in wind and sun to evaporate moisture yields a light, white powder called Fenghuaxiao (Weathered Niter). Boiling Pu Xiao, Mang Xiao, and Ying Xiao together with Gancao (Licorice Root), followed by sublimation in a vessel, produces Yuanmingfen (Yuanming Powder). Scholars of the Tang and Song dynasties did not realize that all forms of Xiao are essentially the same substance, differing only in refinement; their speculative guesses were confused and lacked definitive guidance. (Li Shizhen)
The taste is bitter and salty. The nature is cold. It has slight toxicity. Pu Xiao settles at the bottom and is the coarse form of niter. Its texture is heavy and turbid. Mang Xiao and Yaxiao crystallize at the top and are the refined forms of niter. Their texture is clear and bright. Tianxiao and Fenghuaxiao are further processed from Mang and Ya Xiao, having had their pungent flavors removed, becoming sweet, mild, light, and refreshing. Therefore, Pu Xiao is only suitable for use on rough-skinned individuals or for external application/poultices. For decoctions or powders taken internally, Mang Xiao and Yaxiao are preferred. Zhang Zhongjing’s *Shanghan Lun* uses only Mang Xiao, not Pu Xiao, precisely due to this therapeutic indication. Its main action is not far from that of Mang Xiao. Only the conditions treated by Pu Xiao in *Benjing* are limited to the Six Fu Organs. However, since formulas like Chengqi Decoction entering the Stomach all utilize Mang Xiao, Pu Xiao need not be listed separately.