苦微甘寒，无毒。产怀庆者丁头鼠尾，皮粗质坚，每株重七八钱者力优。产亳
州者头尾俱粗，皮细质柔，形虽长大而力薄。产江浙者细软无力，仅可清热，不入补药。无
问产于何地，但枯槁质轻者谓之天黄，不堪入汤药。
发明 干地黄心紫通心，中黄入脾，皮黑归肾，味浓气薄，内专凉血滋阴，外润皮肤荣
泽。病患虚而有热者宜加用之。戴元礼曰∶阴微阳盛，相火炽强，来乘阴位，日渐煎熬，阴
虚火旺之证，宜生地黄以滋阴退阳，同人参、茯苓、石蜜，名琼玉膏，治虚劳咳嗽唾血。同
天麦门冬、熟地、人参，名固本丸，治老人精血枯槁。于固本丸中加枸杞熬膏名集灵膏，治
虚羸喘嗽乏力。其琼玉膏虽用鲜者捣汁桑木熬膏，散中寓止，与干者无异。固本丸、集灵膏
并用干者，而集灵变丸作膏，较之固本差胜。《易简方》曰∶男子多阴虚宜熟地黄，女子多
血热宜生地黄。虞抟云∶生地黄凉血，而胃气弱者恐妨食。熟地黄补血，而痰饮多者恐泥膈
；或言生地黄酒炒则不妨胃，熟地黄姜制则不泥膈，然须详病患元气病气之浅深而用之。若
产后恶食泄泻，小腹结痛，虚劳，脾胃薄弱，大便不实，胸腹多痰，气道不利，升降窒塞者
，咸须远之。浙产者专于凉血润燥，病患元气本亏，因热邪闭结而舌干焦黑，大小便秘，不
胜攻下者用此，于清热药中通其秘结最妙，以其有润燥之功，而无滋润之患也。愚按∶《本
经》地黄虽列上品，而实性禀阴柔与乡愿不异。譬诸宵人内藏隐隙，外示优容，是以举世名
家靡不藉为滋阴上药，止血神丹。虽或用非其宜，得以稍清旺气，服之仍得暂安。非若人参
之性禀阳明，象类君子，苟有过人皆知之，是以师家敛手不敢用，病家缄口不敢尝，直至滨
危不得已而用之，每至下咽即毙，是以左右之人靡不交口归咎于人参，曷知其为从前误药所
致。夫药之遗患于病比比有之，莫如地黄、门冬之属，阴柔最甚，至死不觉其非，故不惮琐
屑，特表而出之。
干地黄（干燥的地黄根）味苦、微甘，性寒，无毒。产于怀庆府的，其根部呈丁头鼠尾状，外皮粗糙、质地坚硬，每株重七八钱的药效最佳。产于亳州地区的，头尾都粗，外皮细嫩、质地柔软，虽然形体长大但药力薄弱。产于江浙地区的，细小软弱无力，仅能用于清热，不能用于补益方剂中。无论产自何地，凡是干枯萎缩、质地轻浮的称为“天黄”，不堪入汤药使用。
发明：干地黄的心色紫以通心，中间黄色部分入脾，外皮黑色归肾。它味道浓郁而气味淡薄，内部专门凉血滋阴，外部滋润皮肤使其光泽润泽。身体虚弱且有内热的患者适宜加用此药。戴元礼说：阴气微弱而阳气亢盛，相火炽烈强盛，侵犯阴位，日渐煎熬，导致阴虚火旺的病证，宜用生地黄来滋阴退阳，与人参、茯苓、石蜜同用，名为琼玉膏，治疗虚劳咳嗽、唾血。与天门冬、麦门冬、熟地黄、人参同用，名为固本丸，治疗老人精血枯竭。在固本丸中加入枸杞熬成膏，名为集灵膏，治疗身体虚弱羸瘦、喘咳乏力。那琼玉膏虽然是用鲜地黄捣汁、桑木柴熬膏，但在散剂中寓含收敛之意，与干地黄并无二致。固本丸和集灵膏都用干地黄，而集灵膏将丸剂改为膏剂，比固本丸效果稍好。《易简方》说：男子多阴虚适宜用熟地黄，女子多血热适宜用生地黄。虞抟说：生地黄能凉血，但胃气虚弱者恐怕妨碍饮食；熟地黄能补血，但痰饮多者恐怕阻滞胸膈；有人说生地黄酒炒则不伤胃，熟地黄姜制则不滞膈，然而必须详细考察患者的元气强弱和病邪深浅来决定使用。如果是产后恶食泄泻，小腹结痛，虚劳，脾胃薄弱，大便不成形，胸腹多痰，气道不利，升降窒塞的患者，都必须远离此药。浙江产的地黄专门用于凉血润燥，对于患者元气本来亏损，因热邪闭结而导致舌干焦黑，大小便不通，不能耐受攻下法治疗的患者，在此类清热药中通利秘结最为巧妙，因为它有润燥的功效，而没有滋腻碍胃的弊端。我认为：《神农本草经》虽将地黄列为上品，但其实际性质禀赋阴柔，与乡愿之人无异。譬如小人内心隐藏私隙，外表示以宽容，因此举世名医无不借它作为滋阴的上药，止血的圣丹。虽然有时使用不当，也能稍微清降旺盛的火气，服用后仍能暂时安宁。不像人参的性质禀赋阳明，形象类似君子，如果有过错大家都知道，所以医生束手不敢用，病人闭口不敢尝，直到病情危急不得已才使用，往往咽下即死，因此左右之人无不交口指责人参，哪里知道这是从前误用药物所致。药物遗留祸患于病患的情况比比皆是，没有像地黄、麦门冬这类药，阴柔之性最甚，至死都不觉得自己的错误，所以我不怕琐碎，特意陈述出来以警示世人。
Dihuang (dried Rehmanniae Radix) is bitter, slightly sweet, and cold in nature, with no toxicity. Those produced in Huaiqing have a shape resembling a nail head and rat's tail, with rough skin and firm texture; those weighing seven or eight qian per plant possess superior efficacy. Those produced in Bozhou are thick at both ends, with fine skin and soft texture; although large in size, their medicinal power is weak. Those produced in Jiangsu and Zhejiang are thin, soft, and powerless, suitable only for clearing heat, and should not be used in tonifying prescriptions. Regardless of origin, if they are withered, shriveled, and light in weight, they are called "Tianhuang" and are unsuitable for decoctions.
Invention: The purple heart of Dihuang enters the Heart to promote circulation; the yellow middle part enters the Spleen; the black skin returns to the Kidney. It has a strong flavor but faint aroma. Internally, it specializes in cooling blood and nourishing Yin; externally, it moistens the skin and promotes luster. It is suitable for patients who are deficient and have internal heat. Dai Yuanli stated: When Yin is slight and Yang is abundant, and ministerial fire is blazing and strong, invading the Yin positions, causing gradual consumption leading to syndromes of Yin deficiency and hyperactive fire, raw Dihuang (Shengdihuang) should be used to nourish Yin and retreat Yang. Combined with Renshen (Ginseng), Fuling (Poria), and Shimi (Rock Sugar), it is named Qiongyu Gao (Jade Dew Paste), treating consumptive coughing and hemoptysis. Combined with Tianmendong (Asparagi Radix), Maidong (Ophiopogonis Radix), Shudihuang (Prepared Rehmanniae Radix), and Renshen (Ginseng), it is named Guben Wan (Root-Firming Pill), treating elderly patients with withered essence and blood. Adding Gouqi (Lycium Fruit) to Guben Wan and boiling it into a paste creates Jiling Gao (Collection of Spirits Paste), treating emaciation, wheezing, coughing, and fatigue. Although Qiongyu Gao uses fresh Dihuang crushed for juice and boiled with mulberry wood branches, containing retention within dispersion, it is no different from the dried form. Both Guben Wan and Jiling Gao use dried Dihuang, but Jiling Gao changes pills to paste, which is slightly superior to Guben Wan. *Yijian Fang* states: Men often suffer from Yin deficiency and should use Shudihuang (Prepared Rehmanniae Radix); women often suffer from blood heat and should use Shengdihuang (Raw Rehmanniae Radix). Yu Tun said: Shengdihuang cools blood, but may hinder digestion in those with weak Stomach Qi; Shudihuang tonifies blood, but may cause stagnation in those with excessive phlegm-fluids. Some say that wine-frying Shengdihuang does not harm the Stomach, and ginger-processing Shudihuang does not cause stagnation, yet one must carefully examine the depth of the patient's Yuan Qi (Primary Qi) and pathogenic factors before use. In cases of postpartum aversion to food and diarrhea, lower abdominal binding pain, consumptive disease, weak Spleen and Stomach, loose stools, excessive phlegm in chest and abdomen, unsmooth air pathways, and obstructed ascending and descending movements, this herb must be avoided. Dihuang from Zhejiang specializes in cooling blood and moistening dryness. For patients whose Yuan Qi is originally deficient, but due to heat-pathogen obstruction leading to a dry, scorched-black tongue, and constipation of both urine and stool, who cannot tolerate purgative methods, using this among heat-clearing herbs to unblock constipation is most excellent, as it possesses the function of moistening dryness without the drawback of being cloying. I observe: Although *Benjing* lists Dihuang in the Upper Grade, its actual nature is yin-soft, similar to a hypocrite. Like a villain hiding secrets inside while showing tolerance outside, all renowned experts rely on it as a premier herb for nourishing Yin and a divine pill for stopping bleeding. Even if used inappropriately, it can slightly clear excessive Qi, allowing temporary relief after ingestion. Unlike Renshen (Ginseng), whose nature belongs to Yangming and resembles a gentleman, where faults are known to all, doctors hesitate to use it, and patients dare not taste it. Only when critically ill and desperate do they use it, often resulting in death upon swallowing. Thus, everyone blames Renshen, unaware that this is caused by previous medication errors. Medicinal hazards occur frequently, none more so than Dihuang and Mendong (Ophiopogonis Radix), which are extremely yin-soft, remaining unaware of their error even until death. Therefore, I do not shy away from triviality and specifically highlight this for awareness.