虚则空而不实。非有实以镇之。则易覆矣。虚则轻而易败。非有实以投之。则易坠矣。
故重
坠之药。亦为治病者所必需也。然用金石诸药以治。而不审其气味以别。亦非治病通活之妙
。故有热者。宜以凉镇。如代赭石珍珠之治心肝二经热惊。辰砂之清心热。磁石之治肾水虚
怯。龙骨龙齿之治肝气虚浮是也。有寒者宜以热镇。如云母石之能温中去怯。硫黄之能补火
除寒。通便定惊是也。寒热俱有者。宜以平镇。如禹余粮金银薄铁粉密陀僧之属是也。但禹
余粮则兼止脱固泄。金银薄则兼除热祛风。铁粉则兼疗狂消痈。皆借金性平木。密陀僧则兼
除积消热涤痰也。其一镇坠。而药品气味治用各自有别。其不容紊如此。然要病有外邪。不
可轻投。寒邪得镇而愈固耳。
（金）平肝镇怯
金（专入肝）。禀刚健之性。最能杀人。惟作薄乃无伤耳。银薄亦然。二薄性皆辛平。
其治俱
属除邪杀毒。（解热）驱烦安魂定魄。养心和血。止癫除狂。疗惊祛风。幼科镇心丸。衣以
为
饰。皆取金能平木重以镇怯之意云耳。（风热多生于肝。肝属木。故得金为之制。魂魄飞扬
者。其神散而不收。必得重为之镇。）但银薄色白入气。金薄色黄入血。差各有别。畏锡水
银。（遇铅则碎。五金皆畏。）入丸为衣。入汤剂水煮用。
虚证表现为空虚而不充实。如果没有质地沉重的药物来镇摄它，病情就容易恶化（如气机下陷或神志涣散）。虚证表现为轻浮而易于受损。如果没有实质性的药物来填补它，正气就容易坠落耗散。
因此，重坠类的药物，也是治疗疾病者所必需的。然而，如果使用金石类药物进行治疗，却不仔细辨别其气味属性以作区分，也就不是治疗疾病灵活通变的高明手段了。
所以，对于有热邪的病症，适宜用凉性药物来镇摄。例如：代赭石、珍珠用于治疗心经和肝经的热盛惊悸；辰砂用于清泄心经热邪；磁石用于治疗肾水亏虚导致的怯弱；龙骨、龙齿用于治疗肝气虚浮不敛。
对于有寒邪的病症，适宜用热性药物来镇摄。例如：云母石能够温中祛寒并消除怯弱；硫黄能够补益命门之火、驱除寒邪，并能通便、定惊。
对于寒热错杂的病症，适宜用平性药物来镇摄。例如：禹余粮、金银薄（金箔）、铁粉、密陀僧等属于此类。其中，禹余粮兼有固涩止脱、收敛泄泻的作用；金银薄兼有清热祛风的作用；铁粉兼有治疗狂症、消散痈肿的作用，这些都是借助金的肃降之性来平抑肝木；密陀僧兼有消除积滞、清热涤痰的作用。
同一类“镇坠”药物，但其药性气味和治疗用途各自不同，不容混淆如此。然而，如果病证伴有外邪，不可轻易投用重坠药，否则寒邪会被镇压而更加牢固难解。
金（专门入肝经），禀赋刚健之性，最能克伐人体（指过用伤正），只有制成极薄的金箔才无伤害。银箔也是如此。金箔和银箔的药性都是辛平，它们的治疗作用都属于祛除邪毒。（能解热）驱除烦躁、安定魂魄、调和心气、滋养血液，治疗癫狂、消除惊悸、祛除风邪。儿科名方“镇心丸”，将其作为药衣包裹，都是取金能平抑肝木、质重能镇摄怯弱之意。（风热多生于肝，肝属木，故得金来制约；魂魄飞扬者，是因为神气涣散不收，必须用重镇之物来安定。）但是，银箔色白入气分，金箔色黄入血分，二者各有区别。
Deficiency manifests as emptiness and lack of substance. Without heavy substances to anchor it, the condition is prone to collapse. Deficiency implies lightness and susceptibility to damage; without substantial substances to fill it, the healthy qi is prone to sinking and dissipating.
Therefore, heavy and descending medicines are also essential for treating diseases. However, if metal and stone minerals are used for treatment without carefully distinguishing their flavors and thermal properties, it does not constitute the subtle art of flexible and effective therapy.
Thus, for conditions with heat, cool anchoring agents are appropriate. For example: Ochre (Dai Zhe Shi) and Pearl (Zhen Zhu) treat heat-induced palpitations and fright in the Heart and Liver meridians; Cinnabar (Chen Sha) clears Heart heat; Magnetite (Ci Shi) treats deficiency-cold timidity due to Kidney water insufficiency; Dragon Bone (Long Gu) and Dragon Teeth (Long Chi) treat floating and unanchored Liver qi.
For conditions with cold, hot anchoring agents are appropriate. For example: Mica (Yun Mu Shi) warms the middle and dispels timidity; Sulfur (Liu Huang) tonifies Fire, dispels cold, promotes bowel movement, and calms fright.
For conditions with both cold and heat, neutral anchoring agents are appropriate. For example: Halloysitum Rubrum (Yu Yu Liang), Gold Leaf (Jin Yin Bo), Iron Powder (Tie Fen), and Litharge (Mi Tuo Seng) belong to this category. Among them, Halloysitum Rubrum additionally stops leakage and consolidates diarrhea; Gold Leaf additionally clears heat and expels wind; Iron Powder additionally treats mania and resolves carbuncles, all utilizing the metallic nature to calm Wood; Litharge additionally resolves accumulations, clears heat, and washes away phlegm.
Although these are all "anchoring and descending" substances, their medicinal properties, flavors, and therapeutic uses differ distinctly and must not be confused. However, if external pathogenic factors are present, heavy descending agents should not be lightly administered, as cold pathogens would become firmly entrenched by the anchoring action.
[Gold] Calming the Liver and Anchoring Timidity
Metal (specifically enters the Liver meridian) possesses a rigid and vigorous nature, capable of causing harm (to healthy qi if misused); only when processed into thin leaves is it harmless. Silver leaf is similar. Both gold and silver leaves have a pungent and neutral nature. Their therapeutic actions belong to eliminating evil and detoxifying. (They resolve heat,) drive away irritability, stabilize the soul and spirit, harmonize the Heart and nourish blood, treat epilepsy and mania, alleviate fright, and expel wind. In pediatric formulas such as *Zhengxin Wan* (Heart-Calming Pill), they are used as coatings, taking advantage of the principle that metal can subdue Wood and heaviness can anchor timidity. (Wind-heat often arises from the Liver; the Liver belongs to Wood, thus it is controlled by Metal. When the soul and spirit fly upward due to scattered and uncollected Shen, heavy substances are necessary to anchor them.) However, silver leaf is white and enters the Qi level, while gold leaf is yellow and enters the Blood level; there are distinct differences between them. They are incompatible with Tin and Mercury. (Lead causes them to crumble; among the five metals, all fear Lead.) They are used as coatings in pills or boiled in decoctions.