鲜地黄∶性寒，微苦微甘。最善清热、凉血、化瘀血、生新
血，治血热妄行、吐血、衄血、二便因热下血。其中含有铁质，故晒之、蒸之则黑，其生血、凉血之力，亦赖
所含之铁质也。
干地黄（即药局中生地黄）∶经日晒干，性凉而不寒，生血脉，益精髓，聪明耳目，治骨蒸劳热，肾虚生热。
熟地黄（用鲜地黄和酒，屡次蒸晒而成）∶其性微温，甘而不苦，为滋阴补肾主药。治阴虚发热，阴虚不
纳气作喘，劳瘵咳嗽，肾虚不能漉水，小便短少，积成水肿，以及各脏腑阴分虚损者，熟地黄皆能补之。
【附案】邻村李媪，年七旬，劳喘甚剧，十年未尝卧寝。俾每日用熟地煎汤当茶饮之，数日即安卧，其
家人反惧甚，以为如此改常，恐非吉兆，而不知其病之愈也。
侯××之子，五岁，因服凉泻之药太过，致成慢惊，胃寒吐泻，常常螈 ，精神昏愦，目睛上泛，有危
在顷刻之象。为处方，用熟地黄二两，生山药一两，干姜、附子、肉桂各二钱，净萸肉、野台参各三钱，煎汤
一杯半，徐徐温饮下，吐泻螈 皆止，精神亦振，似有烦躁之意，遂去干姜加生杭芍四钱，再服一剂全愈。
一童子，年十四五，伤寒已过旬日，大便滑泻不止，心中怔忡异常，似有不能支持之状。脉至七至，按
之不实。医者辞不治。投以熟地、生山药、生杭芍各一两，滑石八钱，甘草五钱，煎汤一大碗，徐徐温饮下，
亦尽剂而愈。
统观以上诸案，冯氏谓地黄大补肾中元气之说，非尽无凭。盖阴者阳之守，血者气之配，地黄大能滋阴
养血，大剂服之，使阴血充足，人身元阳之气，自不至上脱下陷也。
用熟地治寒温，恒为医家所訾。然遇其人真阴太亏，不能支持外感之热者，于治寒温药中，放胆加熟地
以滋真阴，恒能挽回人命于顷刻。曾治一室女，资禀素羸弱，得温病五六日，痰喘甚剧。治以《金匮》小青龙
汤加石膏，一剂喘顿止。时届晚八点钟，一夜安稳。至寅时喘复作，不若从前之剧，而精神恍惚，心
中怔忡。再诊其脉，如水上浮麻不分至数，按之即无，此将脱之候也。取药不暇，幸有预购山药两许，急煎服
之，病少愈。此际已疏方取药，方系熟地四两、生山药一两、野台参五钱。而近处药局无野台参，并他参亦鬻
尽。再至他处，又恐误事。遂单煎熟地、山药饮之，病愈强半。一日之内，按其方连进三剂，病遂全愈。
按∶此证原当用拙拟来复汤，其方重用山萸肉以收脱。而当时愚在少年，其方犹未拟出，亦不知重用萸
肉。而自晨至暮，共服熟地十二两，竟能救此垂危之证，熟地之功用诚伟哉。又此证初次失处，在服小青龙汤
后，未用补药。愚经此证后，凡遇当用小青龙汤而脉稍弱者，服后即以补药继之。或加人参于汤中，恐其性热，
可将所加之石膏加重。
《张氏八阵》、赵氏《医贯》、《冯氏锦囊》皆喜重用熟地，虽外感证，亦喜用之。其立言诚有偏处。
然当日必用之屡次见效，而后笔之于书。张氏书中载有∶治一老年伤寒，战而不汗，翌日届其时，犹有将汗之
意。急与一大剂八味地黄汤以助其汗。服后，遂得大汗，阅数时周身皆凉，气息甚微，汗犹不止。精神昏昏，
复与原汤一剂，汗止而精神亦复。夫用其药发汗，即用其药止汗，运用之妙，颇见慧心。又赵氏书中谓∶六味
地黄汤能退寒温之实热，致贻后世口实。然其言亦非尽不验。忆昔乙酉、丙戌数年间之寒温病，热入阳明府后，
凡于清解药中，能重用熟地以滋阴者，其病皆愈。此乃一时气运使然，不可笔之于书以为定法也。
又∶冯氏所着本草，谓熟地能大补肾中元气，此亦确论。凡下焦虚损，大便滑泻，服他药不效者，单服
熟地即可止泻。然须日用四五两，煎浓汤服之亦不作闷（熟地少用则作闷多用转不闷），少用则无效。至陈修
园则一概抹倒，直视熟地为不可用，岂能知熟地哉。寒温传里之后，其人下焦虚惫太甚者，外邪恒直趋下焦作
泄泻，亦非重用熟地不能愈。癸巳秋，一女年三十许，得温病，十余日，势至
垂危，将舁于外。同坐贾××谓愚知医，主家延为诊视。其证昼夜泄泻，昏不知人，呼之不应，其脉数至七至，
按之即无。遂用熟地黄二两，生山药、生杭芍各一两，甘草三钱，煎汤一大碗，趁温徐徐灌之，尽剂而愈。
鲜地黄：性寒，味微苦、微甘。最擅长清热、凉血、化瘀血、生新血，治疗因血热妄行导致的吐血、鼻出血，以及大小便因热而下血。其中含有铁质，所以经过日晒或蒸制后会变黑，其生血、凉血的功效，也依赖于所含的铁质。
干地黄（即药店中出售的生地黄）：经日晒干燥后，性凉而不寒，能生血脉，补益精髓，使耳目聪明，治疗骨蒸劳热、肾虚引起的内热。
熟地黄（用鲜地黄加酒，经过多次蒸晒制成）：性微温，味甘而不苦，是滋阴补肾的主药。治疗阴虚发热、阴虚不能纳气导致的喘息、虚劳咳嗽、肾虚不能过滤水液导致的小便短少并积成水肿，以及各脏腑阴分虚损的情况，熟地黄都能进行补益。
【附案】邻村李姓老妇，七十岁，劳喘非常严重，十年未曾躺卧安睡。让她每天用熟地黄煎汤当茶饮用，几天后就能安稳躺卧，她的家人反而非常害怕，认为这样改变常态恐怕不是吉兆，却不知道这是病情痊愈的表现。
侯某某的儿子，五岁，因为服用清凉泻下的药物太过，导致形成慢惊风，胃寒呕吐腹泻，经常抽搐，精神昏沉迷糊，眼球上翻，有危在旦夕的迹象。为此开处方，使用熟地黄二两，生山药一两，干姜、附子、肉桂各二钱，净山茱萸、野台参各三钱，煎取一杯半药汤，慢慢温热服下，呕吐腹泻和抽搐都停止了，精神也振作起来，似乎有些烦躁的意思，于是去掉干姜，加入生杭芍四钱，再服用一剂就完全痊愈了。
一个少年，十四五岁，伤寒病已经过了十天以上，大便滑泄不止，心中心悸异常，好像无法支撑的样子。脉搏跳动七次（一息七至），按之不实。医生推辞不治疗。投以熟地黄、生山药、生杭芍各一两，滑石八钱，甘草五钱，煎取一大碗药汤，慢慢温热服下，也将药汤全部喝完而痊愈。
综合观察以上几个医案，冯氏说地黄大补肾中元气的说法，并非毫无根据。大概阴是阳的守持者，血是气的配偶，地黄非常擅长滋阴养血，大剂量服用，使阴血充足，人身元的阳气，自然就不会出现上脱下陷的情况。
用熟地黄治疗寒温病，经常被医家指责。然而遇到其人真阴极度亏损，不能支持外感热邪的情况，在治疗寒温病的药物中，大胆加入熟地黄来滋补肾中真阴，往往能在顷刻间挽回人命。曾治疗一位少女，资质素来羸弱，得了温病五六天，痰喘非常严重。用《金匮要略》中的小青龙汤加石膏治疗，一剂药后喘息立刻停止。当时已是晚上八点，一夜安稳。到了寅时喘息又发作，不像从前那么剧烈，但精神恍惚，心中心悸。再次诊脉，脉象如水上浮麻，分不清至数，按之即无，这是将脱的征候。来不及取药，幸好预先购买了山药两许，急忙煎服，病情稍有好转。此时已经开了方子去取药，方子是熟地黄四两、生山药一两、野台参五钱。但附近药店没有野台参，其他人参也卖光了。再去别处买，又怕耽误事情。于是单煎熟地黄、山药给她喝，病情好了大半。一天之内，按照原方连续进服三剂，病就完全痊愈了。
按语：这个证候原本应当使用我拟定的来复汤，该方重用山茱萸以收敛元气外脱。而当时我还年轻，那个方子还没有拟定出来，也不知道重用山茱萸。而从早晨到傍晚，共服用了十二两熟地黄，竟然能救活这个垂危的证候，熟地黄的功用确实伟大啊。另外这个证候初次失误，在于服用小青龙汤后，没有紧接着用补药。我经过这个病例后，凡是遇到应当用小青龙汤而脉稍弱的患者，服药后立即用补药继之。或者在汤中加入人参，担心其性热，可以将所加的石膏加重。
《张氏八阵》、赵氏《医贯》、《冯氏锦囊》都喜欢重用熟地黄，即使是外感证，也喜欢使用。他们的言论确实有偏颇之处。然而他们一定是经过屡次见效后，才将其写入书中。张氏书中记载：治疗一位老年伤寒患者，战栗而无汗，第二天到了时候，仍有将要出汗的意思。急忙给予一大剂八味地黄汤以帮助发汗。服用后，于是大汗出，过了几个小时周身皆凉，气息很微弱，汗仍不止。精神昏昏沉沉，又给予原方一剂，汗止而精神也恢复了。用他的药发汗，又用他的药止汗，运用的妙处，颇见智慧之心。另外赵氏书中说：六味地黄汤能退除寒温病的实热，这导致了后世非议。然而他的话也并非完全不灵验。回忆乙酉、丙戌几年间的寒温病，热入阳明腑后，凡是在清解药中，能重用熟地黄以滋阴的，病都痊愈了。这是一时的运气使然，不可将其写入书中作为固定法则。
另外：冯氏所著本草，说熟地黄能大补肾中元气，这也是确切的论述。凡是下焦虚损，大便滑泄，服用其他药物无效的情况，单服熟地黄即可止泻。但是必须每天用四五两，煎浓汤服用也不会感到胸闷（熟地黄少量服用会胸闷，多用反而不闷），少量服用则无效。至于陈修园则一概否定，直视熟地黄为不可用，怎么能了解熟地黄呢？寒温病传里之后，其人下焦虚惫太严重的，外邪常常直接趋向下焦导致泄泻，也不是重用熟地黄不能治愈。癸巳年秋天，一名女子三十岁左右，得了温病，十多天，病势危急，将被抬到外面去。同座的贾某某对我说懂医术，主家请我去诊治。其症状是昼夜泄泻，昏迷不省人事，呼叫不应，脉数达到七至，按之即无。于是用熟地黄二两，生山药、生杭芍各一两，甘草三钱，煎取一大碗药汤，趁温热慢慢灌服，将药汤全部喝完而痊愈。
Fresh Rehmanniae Radix (Xian Dihuang): Its nature is cold, with a slightly bitter and sweet taste. It is most effective in clearing heat, cooling blood, resolving blood stasis, and generating new blood. It treats hemorrhage due to reckless bleeding from blood-heat, such as hematemesis (vomiting blood), epistaxis (nosebleed), and bleeding from the intestines or bladder due to heat. It contains iron substances; therefore, it turns black when sun-dried or steamed. Its ability to generate blood and cool blood also relies on the iron substances it contains.
Dried Rehmanniae Radix (Gan Dihuang) (i.e., Sheng Dihuang sold in pharmacies): After being dried by sun exposure, its nature becomes cool rather than cold. It generates blood vessels, benefits essence and marrow, improves hearing and vision, and treats bone-steaming tidal fever and internal heat generated by Kidney deficiency.
Prepared Rehmanniae Radix (Shu Dihuang) (made by steaming and drying fresh Rehmanniae Radix repeatedly with wine): Its nature is slightly warm, sweet without bitterness. It is the primary herb for nourishing Yin and tonifying the Kidney. It treats fever due to Yin deficiency, wheezing caused by Yin deficiency failing to grasp Qi, consumptive cough, edema resulting from the Kidney's failure to filter water leading to scanty urination, and deficiency damage to the Yin aspect of various Zang-Fu organs. Prepared Rehmanniae Radix can tonify all these conditions.
[Attached Cases] An elderly woman surnamed Li in the neighboring village, aged seventy, suffered severely from exhaustion-induced wheezing and had not been able to lie down and sleep for ten years. She was instructed to decoct Prepared Rehmanniae Radix daily and drink it as tea. Within a few days, she was able to lie down and sleep peacefully. Her family members were extremely frightened, believing that such a change from her usual state might be an ill omen, unaware that it indicated the recovery from illness.
The son of Mr. Hou, five years old, developed slow convulsions (Man Jing) due to excessive administration of cooling and purgative medicines. He presented with cold-stomach vomiting and diarrhea, frequent convulsions, mental confusion, upward deviation of the eyes, and appeared critical. A prescription was formulated using Prepared Rehmanniae Radix (2 liang), raw Dioscoreae Rhizoma (1 liang), Dried Zingiberis Rhizoma, Prepared Aconiti Lateralis Radix, and Cinnamomi Cortex (each 2 qian), cleaned Corni Fructus, and wild Codonopsis Radix (each 3 qian). The herbs were decocted to yield one and a half cups of liquid, which was administered slowly while warm. The vomiting, diarrhea, and convulsions ceased, and his spirit revived, though he showed signs of irritability. Dried Zingiberis Rhizoma was then removed, and raw Paeoniae Radix Alba (4 qian) was added. After one more dose, he fully recovered.
A boy, aged fourteen or fifteen, had passed ten days since the onset of Cold Damage (Shanghan). He suffered from incessant loose stools, severe palpitations, and a feeling of inability to sustain himself. His pulse beat seven times per respiration and felt empty upon pressure. Physicians declined to treat him. I prescribed Prepared Rehmanniae Radix, raw Dioscoreae Rhizoma, and raw Paeoniae Radix Alba (each 1 liang), Talcum (8 qian), and Glycyrrhizae Radix et Rhizoma (5 qian). Decocted into a large bowl, it was administered slowly while warm. He consumed the entire dose and recovered.
Reviewing these cases, Feng’s assertion that Rehmannia greatly tonifies the primal Qi of the Kidney is not baseless. Generally, Yin guards Yang, and Blood complements Qi. Rehmannia excels at nourishing Yin and nourishing Blood. When taken in large doses to ensure sufficient Yin and Blood, the body's primal Yang Qi will naturally not rise excessively or sink downward.
Using Prepared Rehmanniae Radix to treat Cold-Warm diseases is often criticized by physicians. However, in cases where true Yin is severely deficient and cannot withstand the heat of external pathogens, boldly adding Prepared Rehmanniae Radix to formulas treating Cold-Warm diseases to nourish true Yin can often save lives instantly. I once treated a young maiden who was constitutionally weak. After five or six days of Warm Disease, she suffered severe phlegm-wheezing. Treatment with Xiao Qing Long Tang (Minor Green Dragon Decoction) from *Jin Gui Yao Lue* plus Gypsum (Shi Gao) stopped the wheezing after one dose. At 8 PM, she slept peacefully through the night. In the Yin hour (3–5 AM), the wheezing recurred, less severely than before, but she appeared mentally vague and experienced palpitations. Re-examination of the pulse revealed it floating like hemp seeds on water, indistinguishable in rate, and vanishing upon pressure, indicating impending collapse. There was no time to fetch medicine. Fortunately, I had purchased some raw Dioscoreae Rhizoma earlier. It was quickly decocted and administered, leading to slight improvement. By this time, a prescription had already been written for pharmacy pickup: Prepared Rehmanniae Radix (4 liang), raw Dioscoreae Rhizoma (1 liang), and wild Codonopsis Radix (5 qian). However, the local pharmacy had no wild Codonopsis Radix, nor any other Ginseng species. Going elsewhere risked delay. Thus, I simply decocted Prepared Rehmanniae Radix and Dioscoreae Rhizoma for her to drink. Her condition improved significantly. Over the course of one day, three doses according to the original formula were administered consecutively, resulting in full recovery.
Note: This case originally required my formulated Lai Fu Tang, which heavily uses Corni Fructus to secure collapsing Qi. At that time, I was young, and the formula had not yet been devised, so I did not know to use heavy doses of Corni Fructus. From morning to evening, she consumed twelve liang of Prepared Rehmanniae Radix, which successfully saved this critical case. The efficacy of Prepared Rehmanniae Radix is indeed magnificent. Furthermore, the initial error in this case was failing to administer tonic herbs immediately after Xiao Qing Long Tang. After this experience, whenever I encounter patients suitable for Xiao Qing Long Tang but with a slightly weak pulse, I follow the decoction with tonic herbs. If I add Ginseng, fearing its heat, I increase the dosage of Gypsum.
*Zhang Shi Ba Zhen*, Zhao’s *Yi Guan*, and *Feng Shi Jin Nang* all favor heavy use of Prepared Rehmanniae Radix, even in external contraction cases. Their statements are indeed biased. However, they only wrote this after repeated clinical success. Zhang’s book records a case of an elderly man with Cold Damage who shivered but had no sweat. The next day, just as sweating was expected, a large dose of Ba Wei Di Huang Wan (Eight-Ingredient Rehmannia Pill) was given to assist sweating. After ingestion, profuse sweating occurred. Hours later, the whole body cooled, breath became faint, and sweating continued. Mental state was drowsy. Another dose of the original formula stopped the sweating and restored mental clarity. Using the same herb to induce and then stop sweating demonstrates profound skill. Zhao’s book claims Liu Wei Di Huang Wan (Six-Ingredient Rehmannia Pill) can clear excess heat in Cold-Warm diseases, inviting criticism. Yet, his words are not entirely invalid. Recalling the Cold-Warm epidemics during the Yi You and Bing Xu years, after heat entered the Yangming Fu organs, cases treated with clearing and resolving formulas supplemented with heavy doses of Prepared Rehmanniae Radix to nourish Yin all recovered. This was due to specific environmental factors and should not be codified as a fixed rule.
Additionally, Feng’s Materia Medica states that Prepared Rehmanniae Radix greatly tonifies the primal Qi of the Kidney, which is an accurate view. For lower Jiao deficiency with loose stools unresponsive to other drugs, single-use of Prepared Rehmanniae Radix can stop diarrhea. However, it must be used in large doses (four to five liang daily), decocted into a thick liquid. It does not cause chest tightness when used in large amounts (small amounts do cause tightness); small doses are ineffective. Chen Xiuyuan dismisses it entirely, deeming it unusable, showing a lack of understanding of Prepared Rehmanniae Radix. After Cold-Warm diseases transmit inward, if the lower Jiao is severely depleted, external pathogens often directly target the lower Jiao causing diarrhea, which cannot be cured without heavy doses of Prepared Rehmanniae Radix. In autumn of the Gui Si year, a thirty-year-old woman contracted a Warm Disease. After ten days, her condition became critical, and she was about to be carried out. A neighbor, Mr. Jia, knowing I practiced medicine, invited me to examine her. She suffered from day-and-night diarrhea, unconsciousness, unresponsiveness to calls, and a rapid pulse (seven beats per respiration) that vanished upon pressure. I prescribed Prepared Rehmanniae Radix (2 liang), raw Dioscoreae Rhizoma and raw Paeoniae Radix Alba (each 1 liang), and Glycyrrhizae Radix et Rhizoma (3 qian). Decocted into a large bowl, it was administered slowly while warm. She consumed the entire dose and recovered.