滑，利窍，通，行水，体重，泻火气，轻，解肌
滑利窍，淡渗湿，甘益气，补脾胃，寒泻热，降心火。色白入肺，上开腠理而发表（肺
主皮毛），下走膀胱而行水，通六腑九窍津液，为足太阳经（膀胱）本药。治中暑积热，呕
吐烦渴，黄胆水肿，香港脚淋闭（偏主石淋），水泻热痢（六一散加红曲治赤痢，加干姜治白
痢），吐血衄血，诸疮肿毒，为荡热除湿之要剂。消暑散结通乳滑胎（时珍曰∶滑石利窍，
不独小便也。上开腠理而发表，是除上、中之湿热。下利便溺而行水，是除中，下之湿热。
热去则三焦宁而表里和，湿去则阑门通而阴阳利矣。阑门分别清浊，乃小肠之下口。河间益
元散，通治上下表里诸病，盖是此意。益元散，一名天水散，一名六一散，取天一生水，地
六成之之义。滑石六钱，甘草一钱，或加辰砂。滑石治渴，非实止渴，资其利窍，渗去湿热，
则脾胃中和而渴自止耳。若无湿、小便利而渴者，内有燥热，宜滋润，或误服此，则愈亡其
津液而渴转甚矣，故王好古以为至燥之剂）。白而润者良。石苇为使。宜甘草（走泄之性，
宜甘草以和之）。
朴硝，即皮硝
大泻，润燥，软坚
辛能润燥，咸能软坚，苦能下泄，大寒能除热。朴硝酷涩性急，芒硝经炼稍缓。能荡涤
三焦、肠、胃实热，推陈致新（按∶致新则泻亦有补，与大黄同。盖邪气不除，则正气不能
复也）。治阳强之病，伤寒（经曰∶人之伤于寒也必病热，盖寒郁而为热也）疫痢，积聚结
癖，留血停痰，黄胆淋闭，瘰 疮肿，目赤障翳。通经堕胎（丰城尉家有猫，子死腹中，啼
叫欲绝，医以硝灌之，死子即下。后有一牛，亦用此法得活。本用治人，治畜亦验《经疏》
曰∶硝者消也，五金八石，皆能消之，况脏腑之积聚乎？其直往无前之性，所谓无坚不破，
无热不荡者也。病非热邪深固、闭结不通，不可轻投，恐误伐下焦真阴故也。成无己曰∶热
淫于内，治以咸寒，气坚者以咸软之，热盛者以寒消之，故仲景大陷胸汤、大承气汤、调胃
承气汤，皆用芒硝以软坚、去实热。结不至坚者，不可用也。佐之以苦，故用大黄相须为使。
许誉卿曰∶芒硝消散，破结软坚。大黄推荡，走而不守，故二药相须，同为峻下之剂。王好
古曰∶本草言芒硝堕胎，然妊娠伤寒可下者，兼用大黄以润燥，软坚泻热，而母子相安。经
曰∶有故无殒，亦无殒也，此之谓欤。谓药自病当之，故母与胎俱无患也）。硝能柔五金，
化七十二种石为水。生于卤地，刮取煎炼。在底者，为朴硝；在上有芒者，为芒硝；有牙者
，为马牙硝；置风日中，消尽水气，轻白如粉，为风化硝。大黄为使（《本经》、《别录》
∶朴硝、硝石虽分二种，而气味、主治略同。后人辨论纷然，究无定指。李时珍曰∶朴硝下
降，属水性寒；硝石为造炮，焰硝上升，属火性温。昂按∶世人用硝，从未有取其上升而温
者，李氏之说，恐非确论）。
滑石，具有滑利孔窍、通利水道的作用。其质地沉重能泻火气，质地轻扬能解肌表之邪。它味淡能渗湿，味甘能益气补脾胃，性寒能清热降心火。因其色白入肺经，向上可开泄腠理以发表（肺主皮毛），向下可走膀胱以利水，通调六腑及九窍的津液，是足太阳膀胱经的本药。主治中暑积热、呕吐烦渴、黄疸水肿、香港脚淋闭（主要治疗石淋）、水样腹泻和热痢（用六一散加红曲治疗赤痢，加干姜治疗白痢）、吐血衄血、各种疮疡肿毒，是荡涤热邪、祛除湿气的关键药物。它能消暑、散结、通乳、滑胎。（李时珍说：滑石利窍，不仅限于小便。向上开泄腠理以发表，是清除上、中焦的湿热；向下利小便而行水，是清除中、下焦的湿热。热去则三焦安宁而表里调和，湿去则阑门通畅而阴阳利达。阑门分别清浊，位于小肠的下口。刘河间的益元散，通治上下表里诸病，大概就是这个意思。益元散，又名天水散，又名六一散，取“天一生水，地六成之”的含义。方中滑石六钱，甘草一钱，也可加入辰砂。滑石治口渴，并非直接止渴，而是借助其利窍之功，渗去湿热，使脾胃中和而口渴自止。如果没有湿气、小便通利而口渴者，属于内有燥热，应当滋润，如果误服此药，则会更加耗伤津液而使口渴加重，所以王好古认为它是极燥的药物）。以白色润泽者为佳。石苇为其引经药。宜配伍甘草（因其有走泄之性，宜用甘草来调和）。
朴硝，即皮硝。
功效：大泻实热，润燥软坚。
辛味能润燥，咸味能软坚，苦味能下泄，大寒性能除热。朴硝味道酷涩且药性急猛，芒硝经过炼制后药性稍缓。能荡涤三焦、肠、胃的实热，推陈出新（按：推陈致新则泻法也有补益作用，与大黄相同。因为邪气不除，正气就不能恢复）。治疗阳强之病、伤寒（经典说：人受寒邪侵袭必然发热，是因为寒郁结而化热）、疫痢、积聚结癖、留血停痰、黄疸淋闭、瘰疬疮肿、目赤障翳。能通经堕胎（丰城尉家中有一只猫，因子死腹中，啼叫欲绝，医生用硝灌服，死胎随即排出。后来有一头牛，也用此法得以存活。本用于治人，治畜也有效《经疏》说：硝者消也，五金八石都能被它消除，何况脏腑的积聚呢？它具有直往无前的性质，所谓无坚不破，无热不荡。病非热邪深固、闭结不通，不可轻易投用，恐怕误伐下焦真阴的缘故。成无己说：热淫于内，治以咸寒，气坚者用咸味软化它，热盛者用寒性消除它，所以张仲景的大陷胸汤、大承气汤、调胃承气汤，都用芒硝来软坚、去实热。结聚不至坚硬者，不可使用。佐以苦味，所以用大黄相须为使。许誉卿说：芒硝消散，破结软坚。大黄推荡，走而不守，所以二药相须，同为峻下之剂。王好古说：本草记载芒硝堕胎，然而妊娠伤寒可下者，兼用大黄以润燥、软坚泻热，而母子平安。经典说：有故无殒，亦无殒也，说的就是这种情况。谓药力自当于病邪，所以母与胎都无患）。硝能柔化五金，将七十二种石头化为水。生于盐碱地，刮取后煎炼。沉在底部的为朴硝；表面有芒刺的为芒硝；有牙状结晶的为马牙硝；置于风日中，消尽水气，轻白如粉，为风化硝。大黄为其引经药（《本经》、《别录》：朴硝、硝石虽分两种，但气味、主治大致相同。后人辩论纷纷，终究没有定论。李时珍说：朴硝下降，属水性寒；硝石用于造炮，焰硝上升，属火性温。汪昂按：世人用硝，从未有取其上升而温性的，李氏之说，恐怕不是确论）。
Hua Shi (Talcum), possessing the property of lubricating orifices and promoting urination. Its heavy nature drains fire qi, while its light nature releases the muscle layer. It is bland in taste to leach out dampness, sweet in taste to benefit qi and tonify the Spleen and Stomach, and cold in nature to clear heat and descend Heart fire. Because its color is white and enters the Lung meridian, it moves upward to open the Cou Li (pores) and release the exterior (the Lung governs the skin and hair), and moves downward to the Bladder to promote water metabolism. It unblocks the fluids of the Six Fu organs and nine orifices. It is the primary herb for the Foot-Taiyang (Bladder) meridian. It treats summerheat accumulation and heat, vomiting with irritability and thirst, jaundice and edema, Hong Kong foot (podagra) with stranguria (primarily treating stone stranguria), watery diarrhea and dysentery with heat (Liu Yi San added with Red Yeast Rice treats bloody dysentery; added with Dried Ginger treats white dysentery), hematemesis and epistaxis, various sores and toxic swellings. It is a crucial agent for sweeping away heat and removing dampness. It dissipates summerheat, resolves nodules, promotes lactation, and facilitates childbirth (Shizhen said: Talcum lubricates orifices, not limited to urination. Upward opening of Cou Li to release the exterior clears damp-heat from the Upper and Middle Jiao; downward promotion of urination clears damp-heat from the Middle and Lower Jiao. When heat is removed, the Three Jiao becomes tranquil and interior-exterior harmonizes; when dampness is removed, the Lanmen [gate separating clear and turbid] becomes patent and Yin-Yang flows smoothly. The Lanmen separates clear and turbid, located at the lower outlet of the Small Intestine. Hejian's Yi Yuan San treats all diseases of the upper/lower and interior/exterior, embodying this principle. Yi Yuan San, also known as Tian Shui San or Liu Yi San, takes the meaning of "Heaven generates one water, Earth completes six." The formula contains 6 qian of Hua Shi and 1 qian of Gan Cao, optionally adding Chen Sha. Hua Shi treats thirst not by directly stopping it, but by utilizing its orifice-lubricating property to leach out damp-heat, thereby restoring Spleen-Stomach harmony and naturally stopping thirst. If there is no dampness, urination is free, yet thirst persists, it indicates internal dry-heat, requiring moistening. Misuse of this herb will further deplete body fluids and worsen thirst; thus, Wang Haogu considered it an extremely drying agent). White and moist specimens are superior. Shi Wei serves as the guiding herb. It should be combined with Gan Cao (due to its draining nature, Gan Cao is used to harmonize it).
Pu Xiao (Mirabilite crude), also known as Pi Xiao.
Efficacy: Strong purgation, moistening dryness, softening hardness.
Pungency can moisten dryness, saltiness can soften hardness, bitterness can purge downward, and great coldness can eliminate heat. Pu Xiao has a harsh, astringent taste and urgent nature, whereas Mang Xiao (refined Mirabilite) is slightly milder after processing. It can sweep away excess heat in the Three Jiao, intestines, and stomach, pushing out the old to generate the new (Note: Generating the new implies that purging can also have a tonifying effect, similar to Da Huang. This is because if pathogenic factors are not eliminated, healthy Qi cannot recover). It treats Yang hyperactivity disorders, Shanghan (The Classics state: Injury by cold inevitably leads to heat, as cold stagnates and transforms into heat), epidemic dysentery, accumulations and masses, retained blood and phlegm, jaundice and stranguria, scrofula and sores, red eyes and cataracts. It unblocks menstruation and induces abortion (An official in Fengcheng had a cat whose kittens died in the womb, crying desperately. A doctor administered nitrate/niter, and the dead kittens were expelled. Later, a cow was treated similarly and survived. Originally used for humans, it is also effective for animals *Jing Shu* states: Xiao means to dissolve; it can dissolve metals and stones, let alone accumulations in the Zang-Fu organs. Its nature advances relentlessly, described as "nothing hard it does not break, nothing hot it does not sweep." It should not be lightly prescribed unless the disease involves deep-seated heat pathogens and severe obstruction, lest it mistakenly damage the True Yin of the Lower Jiao. Cheng Wuji stated: For heat rampant within, treat with salty-cold; use salty to soften hardness, and cold to eliminate excessive heat. Thus, Zhang Zhongjing's Da Xian Xiong Tang, Da Cheng Qi Tang, and Tiao Wei Cheng Qi Tang all use Mang Xiao to soften hardness and remove excess heat. If the accumulation is not hard, it should not be used. Assisted by bitter herbs, Da Huang is used as a complementary guide. Xu Yuqing stated: Mang Xiao dissolves and disperses, breaking knots and softening hardness. Da Huang pushes and sweeps, moving without staying; thus, the two herbs complement each other as strong purgatives. Wang Haogu stated: Materia Medica records that Mang Xiao induces abortion, yet in pregnancy complicated by Shanghan where purging is indicated, combining it with Da Huang to moisten dryness, soften hardness, and drain heat allows mother and fetus to remain safe. The Classics say: "If there is a cause, there is no injury, nor to the injured," which refers to this. It means the medicine targets the pathology, so neither mother nor fetus suffers)." Niter can soften metals and transform seventy-two types of stones into water. It grows in saline lands, scraped and refined. The substance settling at the bottom is Pu Xiao; the crystalline substance on top with sharp edges is Mang Xiao; the tooth-like crystals are Ma Ya Xiao; placed in wind and sun until moisture evaporates, becoming light and white like powder, it is Feng Hua Xiao. Da Huang serves as the guiding herb (*Ben Jing*, *Bie Lu*: Although Pu Xiao and Xiao Shi are classified as two substances, their flavors and therapeutic actions are roughly similar. Later debates were numerous but inconclusive. Li Shizhen stated: Pu Xiao descends, belonging to Water nature and cold; Xiao Shi used for fireworks, Yan Xiao ascends, belonging to Fire nature and warm. Ang notes: In common usage, niter is never taken for its ascending and warming properties; Li's theory is likely inaccurate).