燥，劫痰涎，外用杀虫
辛冷（时珍曰∶燥有毒）。杀虫治疮，劫痰消积（能消涎积。十枣汤加大黄、牵牛、轻
粉，名三化神 散），善入经络，螈 药多用之。不可过服常用（时珍曰∶水银阴毒，用火
丹砂而出。再加盐、矾，炼为轻粉。轻扬燥烈，走而不守，今人用治杨梅毒疮。虽能劫风
痰湿热从牙龈出，邪郁暂解，然毒瓦斯窜入经络，筋骨血液耗亡，筋失所养，变为筋挛骨痛。
痈肿疳漏，遂成废痼，贻害无穷。上下齿龈，属手足阳明肠胃经。毒瓦斯循经上行，至齿龈薄
嫩之处而出）。土茯苓、黄连、黑铅、铁浆、陈酱能制其毒。
重，明目
甘酸而寒。益肝明目，通窍利水。产铜坑中。大块、中空有水者良。
补中
甘平属金，色白入肺。下气补中，坚肌续绝。治劳伤疟痢，疮肿痈疽（同黄丹熬膏贴之
。《千金翼》∶用敷金疮。青城山人康道丰，有云母粉方，能治百病）。有五色，以色白光
莹者为上。古人亦有炼服者（云母入火，经时不焦，入土不腐，故云服之长生）。使泽泻。
恶羊肉。
体重，泻火气，轻，解肌
甘辛而淡，体重而降。足阳明经（胃）大寒之药。色白入肺，兼入三焦（诸经气分之药）。
寒能清热降火，辛能发汗解肌，甘能缓脾益气，生津止渴。治伤寒郁结无汗，阳明头痛，
发热恶寒，日晡潮热。肌肉壮热（经云∶阳盛生外热），小便赤浊，大渴引饮，中暑自
汗（能发汗，又能止自汗），舌焦（胎浓无津）牙痛（阳明经热，为末擦牙固齿）。又胃
主肌肉，肺主皮毛，为发斑、发疹之要品（色赤如锦纹者为斑，隐隐见红点者为疹，斑
重而疹轻。率由胃热，然亦有阴阳二证，阳证宜用石膏。又有内伤阴证见斑疹者，微红
而稀少，此胃气极虚，逼其无根之火游行于外，当补益气血，使中有主，则气不外游，
血不外散，若作热治，死生反掌，医者宜审），但用之甚少，则难见功（白虎汤以之为
君，或自一两加至四两，竹叶、麦冬、知母、粳米，亦加四倍，甚者加芩、连、柏，名
三黄石膏汤，虚者加人参，名人参白虎汤）。然能寒胃，胃弱血虚及病邪未入阳明者禁
用（成无己解大青龙汤曰∶风、阳邪伤卫，寒，阴邪伤营，营卫阴阳俱伤，则非轻剂所
能独散，必须重轻之剂同散之，乃得阴阳之邪俱去，营卫俱和，石膏乃重剂，而又专达
肌表也。质重气轻，又成氏以桂麻为轻剂，石膏为重剂也。东垣曰∶石膏足阳明药，仲
景用治伤寒阳明证，身热、目痛、鼻开、不得卧，邪在阳明，肺受火制，故用辛寒以清
肺气，所以有白虎之名，肺主西方也。按∶阳明主肌肉，故身热；脉交额中，故目痛；
脉起于鼻，循鼻外，金燥，故鼻干；胃不和，则卧不安，故不得卧。
然亦有阴虚发热，及脾胃虚劳，伤寒阴盛格阳、内寒外热、类白虎汤证、误投之不可救
也。
按阴盛格阳，阳盛格阴二证，至为难辨，盖阴盛极而格阳于外，外热而内寒；阳盛极而格阴
于外，外冷而内热。经所谓重阴必阳，重阳必阴，重寒则热，重热则寒是也。当于小便分之
，便清者，外虽燥热，而中实寒；便赤者，外虽厥冷，而内实热也。再看口中之燥润，及舌
苔之浅深，胎黄、黑者为热，宜白虎汤；然亦有舌黑属寒者，舌无芒刺，口有津液也，急宜
温之，误投寒剂即死矣）。亦名寒水石（时珍曰∶古方所用寒水石是凝水石，唐、宋诸方用
寒水石即石膏。凝水石乃盐精渗入土中，年久结成，清莹有棱，入水即化。辛咸大寒，治时
气热盛，口渴水肿）莹白者良。研细，甘草水飞用。近人因其寒，或用火 ，则不伤胃，味
淡难出。若入煎剂，须先煮数十沸，鸡子为使。忌巴豆、铁。
【性味与功效】
味辛、性冷（李时珍说：燥烈且有毒）。能杀虫治疗疮疡，劫夺痰涎消除积滞（能够消除痰涎积滞。在十枣汤中加入大黄、牵牛子、轻粉，称为三化神散），善于进入经络，治疗抽搐痉挛的药物多使用它。不可过量服用或长期常用（李时珍说：水银属阴毒，用火炼丹砂而析出。再加盐、矾，炼制为轻粉。其性质轻扬燥烈，走窜而不守中，现在人用它治疗杨梅毒疮。虽然能劫夺风痰湿热从牙龈排出，邪气郁结暂时解除，但是毒气窜入经络，导致筋骨血液耗损枯竭，筋脉失去滋养，变为筋挛骨痛。痈肿、疳疮、瘘管，遂成顽固废疾，贻害无穷。上下齿龈，属于手足阳明肠胃经。毒气循经上行，至齿龈薄嫩之处而出）。土茯苓、黄连、黑铅、铁浆、陈酱能够制约它的毒性。
【重石膏】
质重，能明目。
味甘、酸，性寒。补益肝脏，明目，通利窍道，利尿。产于铜矿坑中。大块、中间空心且有水的品质优良。
【云母】
补益中焦。
味甘，性平，属金，色白入肺。降气补中，坚固肌肉，接续断绝。治疗劳伤、疟疾、痢疾，疮肿痈疽（与黄丹一起熬膏贴敷。《千金翼方》：用于敷治金创。青城山人康道丰，有云母粉方，能治疗百病）。云母有五色，以色白光莹的为上品。古人也有炼制服用的（云母投入火中，长时间不焦；投入土中，长时间不腐烂，所以说服用它能长生）。配伍泽泻。畏羊肉。
【生石膏】
体重，能泻火气；质轻，能解肌。
味甘、辛，性淡，体重而降。是足阳明经（胃）大寒之药。色白入肺，兼入三焦（是调理诸经气分的药物）。寒性能清热降火，辛性能发汗解肌，甘性能缓脾益气，生津止渴。治疗伤寒郁结无汗，阳明头痛，发热恶寒，日晡潮热。肌肉壮热（经文说：阳盛产生外热），小便赤浊，大渴引饮，中暑自汗（既能发汗，又能止住自汗），舌焦（舌苔厚腻无津液），牙痛（阳明经热，研末擦牙可固齿）。又因为胃主肌肉，肺主皮毛，它是治疗发斑、发疹的重要药物（颜色红如锦纹的是斑，隐隐可见红点的是疹，斑重而疹轻。大多由胃热引起，但也有阴阳两种证型，阳证宜用石膏。又有内伤阴证出现斑疹的，颜色微红而稀少，这是胃气极虚，逼迫无根之火游行于外，应当补益气血，使中有主宰，则气不外游，血不外散，如果当作热证治疗，生死只在反掌之间，医者应当审慎）。但用量很少，则难以见效（白虎汤以它为君药，或者从一两加至四两，竹叶、麦冬、知母、粳米，也加四倍，严重的加黄芩、黄连、黄柏，称为三黄石膏汤，体虚者加人参，称为人参白虎汤）。然而它能寒伤胃气，胃弱血虚及病邪未入阳明经者禁用（成无己解释大青龙汤说：风，是阳邪伤卫气；寒，是阴邪伤营血。营卫阴阳俱伤，则非轻剂所能单独解散，必须轻重之剂同用才能解散，才能使阴阳之邪俱去，营卫调和。石膏乃重剂，而又专门达于肌表。质地重而气轻，所以成氏以桂枝、麻黄为轻剂，石膏为重剂。东垣说：石膏是足阳明经药，仲景用它治疗伤寒阳明证，身热、目痛、鼻干、不得卧，邪在阳明，肺受火制，所以用辛寒以清肺气，因此有白虎之名，肺主西方。按：阳明主肌肉，所以身热；经脉交于额中，所以目痛；经脉起于鼻，循行鼻外，金燥，所以鼻干；胃不和，则卧不安，所以不得卧。
然而也有阴虚发热，以及脾胃虚劳，伤寒阴盛格阳、内寒外热、类似白虎汤证的情况，误投此药不可救治。
按：阴盛格阳、阳盛格阴二证，极难辨别，大概阴盛极而格阳于外，表现为外热而内寒；阳盛极而格阴于外，表现为外冷而内热。经文所谓重阴必阳，重阳必阴，重寒则热，重热则寒就是这种情况。应当通过小便来分辨，小便清的，外虽燥热，而中实寒；小便赤的，外虽厥冷，而内实热。再看口中的干燥湿润，及舌苔的浅深，舌苔黄、黑者为热，宜用白虎汤；然而也有舌黑属寒的，舌无芒刺，口有津液，急宜温之，误投寒剂即死矣）。又名寒水石（李时珍说：古方所用的寒水石是凝水石，唐、宋诸方用的寒水石即石膏。凝水石乃盐精渗入土中，年久结成，清莹有棱，入水即化。辛咸大寒，治疗时气热盛，口渴水肿）以莹白者为良。研细，用甘草水飞制使用。近人因其寒凉，或用火煅，则不伤胃，但味道淡难以析出有效成分。若入煎剂，须先煮数十沸，鸡蛋清为使药。忌巴豆、铁。
[Properties and Actions]
Pungent, cold (Li Shizhen stated: dry, toxic). Kills parasites and treats sores; eliminates phlegm and resolves accumulation (can eliminate phlegmatic accumulation. Adding Da Huang, Qian Niu, and Qing Fen to Shi Zao Tang is called San Hua Shen San), enters the meridians well, and is frequently used in formulas treating spasms. Do not overdose or use for long periods (Li Shizhen stated: Mercury Yin is toxic; it is extracted from Cinnabar using fire. With added salt and alum, it is refined into Qing Fen. Its nature is light, dry, and acrid; it moves freely without staying put. Currently, people use it to treat yaws. Although it can force wind-phlegm-damp-heat out through the gums, temporarily relieving pathogenic stagnation, the toxin invades the meridians, depleting the sinews, bones, and blood. The sinews lose nourishment, leading to tendon spasms and bone pain. Abscesses, gan ulcers, and fistulas become chronic disabilities, causing endless harm. The upper and lower gingiva belong to the Hand and Foot Yangming Stomach and Large Intestine meridians. Toxins ascend along the meridians and exit at the thin and tender gingival tissue. Tu Fu Ling, Huang Lian, Hei Qian, Tie Jiang, and Chen Jiang can restrain its toxicity.)
[Heavy Gypsum - Chong Shi Gao]
Heavy, brightens the eyes.
Sweet, sour, cold. Benefits the Liver, brightens the eyes, opens orifices, and promotes urination. Produced in copper mines. Those that are large, hollow in the center, and contain water are of good quality.
[Yun Mu - Mica]
Tonifies the Middle Jiao.
Sweet, neutral, associated with Metal, white color enters the Lung. Descends Qi, tonifies the Middle, strengthens muscles, and reconnects severed tissues. Treats labor injury, malaria, dysentery, abscesses, and carbuncles (boiled with Huang Dan to make a paste for external application. *Qian Jin Yi Fang*: used for dressing metal wounds. Kang Daofeng, a hermit from Qingcheng Mountain, had a formula of Yun Mu powder that could treat hundred diseases). There are five colors; those that are white and lustrous are superior. Ancients also refined and ingested it (Mica does not burn even after long exposure to fire, nor does it rot when buried in soil, hence it was said to promote longevity). Paired with Ze Xie. Adverse to mutton.
[Raw Gypsum - Sheng Shi Gao]
Heavy weight, drains Fire Qi; light texture, releases the muscle layer.
Sweet, pungent, bland; heavy in texture and descending. It is a great-cold herb for the Foot Yangming (Stomach) meridian. White color enters the Lung; it also enters the San Jiao (it is an herb for regulating Qi in all meridians). Coldness clears heat and descends fire; pungency induces sweating and releases the muscle layer; sweetness moderates the Spleen, benefits Qi, generates fluids, and stops thirst. It treats Shaoyang constraint with no sweat, Yangming headache, fever with aversion to cold, afternoon tidal fever. Muscular high fever (The Classic states: Excess Yang generates external heat); red and turbid urine, extreme thirst with desire to drink; summerheat stroke with spontaneous sweating (can induce sweating but also stop spontaneous sweating); scorched tongue (thick coating without fluid); toothache (Yangming meridian heat; powdered and applied to teeth to strengthen them). Furthermore, since the Stomach governs muscles and the Lung governs skin and hair, it is a key herb for treating macules and papules (Red like brocade patterns are macules; faint red spots are papules; macules are severe, papules are mild. Mostly caused by Stomach heat, but there are both Yin and Yang syndromes. For Yang syndromes, Shi Gao is suitable. In cases of internal injury Yin syndrome presenting with macules/papules, they are faint red and sparse, indicating extreme deficiency of Stomach Qi forcing rootless Fire to wander externally. One should tonify Qi and Blood to provide an internal anchor, preventing Qi from wandering and Blood from scattering. If treated as Heat, death or life depends on a moment's decision; physicians must be cautious). However, if used in small doses, efficacy is hard to achieve (Bai Hu Tang uses it as the Sovereign herb, increasing from 1 liang to 4 liang; Zhu Ye, Mai Dong, Zhi Mu, and Jing Mi are increased fourfold; in severe cases, Huang Qin, Huang Lian, and Huang Bo are added, called San Huang Shi Gao Tang; for deficiency, Ren Shen is added, called Ren Shen Bai Hu Tang). Yet it can chill the Stomach; it is contraindicated in weak Stomach, Blood deficiency, and when pathogens have not entered the Yangming meridian (Cheng Wuji explained Da Qing Long Tang: Wind, a Yang pathogen, injures Wei Qi; Cold, a Yin pathogen, injures Ying Blood. When Ying, Wei, Yin, and Yang are all injured, light agents alone cannot disperse them; heavy and light agents must be used together to disperse both Yin and Yang pathogens, harmonizing Ying and Wei. Shi Gao is a heavy agent that specifically reaches the muscle surface. Heavy in substance but light in Qi, Cheng classified Gui Zhi and Ma Huang as light agents and Shi Gao as a heavy agent. Dong Yuan stated: Shi Gao is a Foot Yangming herb. Zhong Jing used it to treat Yangming syndrome of Shang Han, characterized by fever, eye pain, nasal dryness, and inability to sleep. The pathogen is in Yangming, and the Lung is constrained by Fire, so pungent-cold herbs are used to clear Lung Qi, hence the name Bai Hu (White Tiger), as the Lung governs the West. Note: Yangming governs muscles, hence fever; meridians intersect at the forehead, hence eye pain; meridians originate at the nose and run along the lateral side, Metal is dry, hence nasal dryness; Stomach disharmony leads to restless sleep, hence inability to sleep.
However, there are also Yin deficiency with fever, Spleen/Stomach deficiency exhaustion, and Shang Han Yin excess repelling Yang (internal cold with external heat) or conditions resembling Bai Hu Tang syndrome; misapplication here is incurable.
Note: Yin excess repelling Yang and Yang excess repelling Yin are extremely difficult to differentiate. When Yin excess is extreme, it repels Yang outward, resulting in external heat but internal cold; when Yang excess is extreme, it repels Yin outward, resulting in external cold but internal heat. This corresponds to the Classic saying: Extreme Yin transforms to Yang, extreme Yang transforms to Yin; extreme cold becomes heat, extreme heat becomes cold. Differentiation should be based on urination: clear urine indicates external dryness/heat but internal actual cold; red urine indicates external cold limbs but internal actual heat. Also observe moisture in the mouth and depth of tongue coating: yellow or black coating indicates heat, suitable for Bai Hu Tang; however, black coating can also indicate cold if there are no prickles on the tongue and saliva is present. In such cases, warming is urgent; misusing cold herbs will cause death). Also known as Han Shui Shi (Li Shizhen stated: Ancient formulas referred to Ning Shui Shi as Han Shui Shi; Tang and Song formulas referred to Shi Gao as Han Shui Shi. Ning Shui Shi is formed when salt essence penetrates the soil over years, crystallizing clearly with edges, dissolving instantly in water. Pungent, salty, great-cold; treats epidemic heat excess, thirst, and edema). Those that are clear and white are best. Finely ground and processed by levigation with Gan Cao water. Modern practitioners, due to its coldness, sometimes calcine it with fire to prevent stomach injury, but this makes the flavor bland and active ingredients hard to extract. If decocted, it must be boiled first for dozens of boils; Ji Zi (Egg White) is the guide. Contraindicated with Ba Dou and Iron.