铅，味甘，无毒。禀北方壬癸阴极之精，性懦而滑，色黑而缁。镇心安神，主鬼疰瘿瘤，
止
反胃呕吐。蛇蝎伤毒，炙熨亦良。
铅霜，止惊怪呕逆，解酒毒，消痰，疗胸膈烦闷，逐中风痰实。
黄丹，膏敷金疮，生长肌肉住痛。入药治痫疾，收敛神气，镇惊除毒热，止反胃吐逆。
自然铜，亦铅之类，未炼矿者也。火 醋淬，研细末。治跌损，接骨续筋，疗折伤，散血止
痛，热酒调服，立建奇功。若非 成，切勿误服。
以上四种，用之得宜，俱可活人，用之失宜，均能杀人。盖铅性至寒，非大热、实热之
病不
可用。铅霜更甚于铅，尤宜慎用。黄丹力轻于铅，然外科可以多用，而内治亦不宜多用也。
自然铜，乃治折伤之神药，然而老弱之人，亦宜少用。盖老人孤阳而少精，弱人气虚而
少血
。跌损之病，虽尚接续，然必以生地、当归、川芎、牛膝之类为君臣，少加自然铜为佐使，
则取效既捷，而精血又复不伤。倘止投自然铜，以求速效，绝不加入补血、补精之味，则火
之物，其性大燥，以燥助燥，必生大热，况又是老弱之人，何能胜此乎？骨虽接续，而变
病即生，其祸有不可胜状者矣。
或问缪仲醇疏黑铅谓“天一生水，中含生气，为万物之先，金丹之母，八石之祖，五金
之宝
。壬金为清，癸水为浊。清为阳气，浊为阴质。阳气为生，阴质有毒。范以法象，招摄阴阳
，烹炼得宜，是成丹药，饵之仙去”等语，是黑铅炼服，果可羽化乎？嗟乎！此缪仲醇误读
丹经，私臆而妄注也。夫黑铅性沉，镇坠阳气，使火入阴分，或治阳气垂绝，阴阳将离等症
，实有奇功。欲其换骨出神，飞霄冲汉，乌可得哉。（〔批〕天元服食，实有此理，未可尽
非也。）
Lead (Qian), sweet in taste, non-toxic. It inherits the extreme yin essence of the North Ren-Gui water, possessing a weak and slippery nature, with a black and dark color. It calms the heart and soothes the spirit (Zhen Xin An Shen), primarily treating ghostly affections (Gui Zhu) and goiters/nodules (Ying Liu), and stops regurgitation and vomiting. For snake or scorpion bites/poison, roasting and hot compresses are also effective.
Lead Frost (Qian Shuang) stops惊怪 (startling/abnormal) retching and reversal, resolves alcohol toxicity, eliminates phlegm, treats chest and diaphragm oppression/stuffiness, and expels wind-stroke phlegm-solidity.
Yellow Cinnabar (Huang Dan), when made into ointment for application to metal wounds, promotes muscle growth and stops pain. When taken internally to treat epilepsy (Xian Ji), it consolidates the spirit, calms fright, removes toxic heat, and stops regurgitation and vomiting.
Natural Copper (Ziran Tong) is also a type of lead, being unrefined ore. It is calcined by fire and quenched in vinegar, then ground into fine powder. It treats falls and injuries, reconnects bones and tendons, heals fractures, disperses blood stasis and stops pain; when mixed with warm wine and taken orally, it achieves miraculous results immediately. If not refined into the proper form, do not take it by mistake.
The above four substances, if used appropriately, can all save lives; if used inappropriately, they can all cause death. This is because lead's nature is extremely cold; it cannot be used unless the disease is characterized by excessive heat or solid-heat. Lead Frost is even more potent than lead itself and should be used with particular caution. Yellow Cinnabar is milder than lead; however, while it can be used more frequently in external surgery, it is also not advisable to use it excessively in internal treatment.
Natural Copper is a divine medicine for treating fractures, yet elderly and weak individuals should also use it sparingly. The reason is that the elderly have isolated yang and scant essence, while the weak have qi deficiency and scant blood. Although fall injuries require bone and tendon connection, one must use Rehmanniae Radix Preparata (Sheng Di), Angelicae Sinensis Radix (Dang Gui), Ligusticum Chuanxiong Rhizoma (Chuan Xiong), and Achyranthis Bidentatae Radix (Niu Xi) as sovereign and minister drugs, adding only a small amount of Natural Copper as assistant and envoy. In this way, efficacy is rapid without damaging essence and blood. If one solely administers Natural Copper seeking quick results, without adding blood-nourishing and essence-replenishing herbs, then, as a fire-element substance, its nature is highly drying. Using dryness to assist dryness will inevitably generate excessive heat. How can an elderly or weak person withstand this? Although the bones may reconnect, secondary diseases will arise, leading to disasters beyond description.
Someone asked about Miao Zhongchun’s commentary on Black Lead, stating: "Heaven generates Water at One, containing the vital breath, preceding all things, mother of Golden Elixir, ancestor of the Eight Stones, treasure of the Five Metals. Ren Metal is clear, Gui Water is turbid. Clarity is Yang Qi, turbidity is Yin Substance. Yang Qi is life, Yin Substance is toxic. Modeled after cosmic phenomena, attracting and capturing Yin and Yang, properly roasted and refined, it becomes a medicinal pill; ingesting it leads to immortality." Do these words imply that refined Black Lead can truly grant ascension? Alas! This is Miao Zhongchun misreading the alchemical classics and making presumptuous annotations based on private speculation. Black Lead is heavy and sinking, suppressing Yang Qi and causing Fire to enter the Yin aspect. It indeed has miraculous effects in treating conditions where Yang Qi is perishing or Yin and Yang are about to separate. But to expect it to transform the bones and emerge from the spirit, flying through the clouds and reaching the heavens, how is that possible? ([Commentary] Tian Yuan's ingestion practices do have some truth to them and cannot be entirely dismissed.)