产吴兴者胜。直下抽根一二十条。类牛膝而短。一种味极苦涩。经冬不凋。名
石龙胆。类同而种别。（核）
根苦涩。大寒。气味俱浓。沉而降。阴也。足厥阴少阳经气分药。又入足少阴阳明经。
草龙胆是少阳枢药。少阳化气。属相火。用苦寒对待治之。（之颐）主肝胆邪热。下焦湿火
肿痛。疗骨间寒热。惊痫邪气。目中肿痛诸患。除胃中伏热。湿热黄胆。时气温热。热泻下
痢。治小儿壮热骨热。惊痫入心。时疾热黄。（诸本草）除下部风湿及湿热。（肝胆为风木之
脏。而藏血者。固易为湿热之病。）治脐下至足肿痛。并寒湿香港脚。下行之功与防己同。酒
浸则能上行外行。治眼中之病必用。如两目赤肿睛胀。瘀肉高起。痛不可忍。当以柴胡为主。
胆草为使。（洁古）同苦参牛胆。治谷疸。同生地。治湿热伤血分。侵入大肠。以致卒下血。
同白芍甘草茯神麦冬木通。主小儿惊痫入心。壮热骨热。时疾热黄。口疮。同苦参蛆虫灰青
黛
〔论〕百物之生。气在味先。寒者水之气。热者火之气。气寒味苦者。本下降之气而泄。
气热味苦者。即本上升之气而泄。然阳者其精奉于上。元气以升为补。不若阴寒。其精降于
下。合于味之苦者。乃为泄也。龙胆草气大寒。味甚苦。就水中大泄火热。故用以治肝胆火。
并湿中蓄热者。夫肝胆表里。为相火所寄。与手厥阴少阳。历遍三焦之间。下合于脾肾之阴
以病。则为湿热。上合于肺胃之阳以病。则为风热。种种见证。须明其为本病为合病而用之
。或主或辅。庶乎适宜。要之。此等苦寒。可以治后天气血之病。不可以治先天元阴元阳之
病。即治气血。亦治有余而为热之病。非治不足而为热之病也。人身相火。在包络三焦则为
先天。在肝胆即为后天。后天藉先天以生。先天藉后天以成。如后天气血诸病。累及先天。
有时须于胆草。（惟肝胆为后天相火。故每与中五之土相为用。相为病。义见胡黄连条下。）
如泄后天相火。反致有伤谷气。又岂得为肝之利益哉。故用者宜审。
缪氏云。大寒纯阴。能除实热。胃虚血少之人。不可轻视。亦弗空腹服。令人溺不禁。
以其太苦。下泄太甚也。
〔修治〕 铜刀刮去须土。锉细。甘草水浸一宿。晒干。虚人酒炒黑用。
The Gentianae Radix et Rhizoma produced in Wuxing is of superior quality. The rhizome grows straight down, producing twenty or more roots. It resembles Achyranthis Bidentatae Radix (Niuxi) but is shorter. One variety has an extremely bitter and astringent taste, does not wither through winter, and is named Shi Longdan (Stone Gentian). Although similar in appearance, it is a different species. (He)
The root is bitter and astringent, with a great cold nature. Its qi and flavor are both strong. It sinks and descends, belonging to the Yin category. It is a drug for the Qi level of the Foot Jueyin Liver Meridian and Foot Shaoyang Gallbladder Meridian, and also enters the Foot Shaoyin Kidney Meridian and Foot Yangming Stomach Meridian.
Cao Longdan (Grass Gentian) is a drug that regulates the pivot of Shaoyang. Shaoyang transforms Qi, which belongs to Ministerial Fire (Xianghuo), and is treated using bitter-cold substances to counteract it. (Zhiyi) It primarily treats evil heat in the Liver and Gallbladder, swelling and pain caused by damp-heat in the Lower Jiao, chills and fever between the bones, convulsions, epilepsy, and other evil pathogens, as well as various eye swellings and pains. It clears latent heat in the Stomach, jaundice due to damp-heat, febrile diseases from seasonal warm pathogens, hot diarrhea, and dysentery. It treats high fever and bone-steaming heat in children, convulsions and epilepsy affecting the Heart, and hot jaundice from epidemic febrile diseases. It removes wind-dampness and damp-heat in the lower body. (Since the Liver and Gallbladder are the organs of Wind-Wood and store Blood, they are prone to damp-heat diseases.) It treats swelling and pain from the umbilicus down to the feet, and gout (Hongxiangjiao) caused by cold-dampness. Its descending efficacy is similar to that of Stephaniae Tetrandrae Radix (Fangji); if soaked in wine, it can ascend and move outward. It must be used for treating eye diseases, such as redness and swelling of both eyes, distension of the eyeballs, protrusion of pterygium (Yu Rou), and unbearable pain. In such cases, Bupleuri Radix (Chaihu) should be the chief herb, and Gentianae Radix et Rhizoma (Dancao) the assistant herb. (Jiegu) Combined with Sophorae Flavescentis Radix (Kushen) and Niu Dan, it treats Gu Dan (Grain Jaundice). Combined with Rehmanniae Radix Recens (Shengdi), it treats damp-heat injuring the Blood level, invading the Large Intestine, leading to sudden hematochezia. Combined with Paeoniae Radix Alba (Baishao), Glycyrrhizae Radix et Rhizoma (Gancao), Poria (Fushen), Ophiopogonis Radix (Maidong), and Akebiae Caulis (Mutong), it treats pediatric convulsions and epilepsy affecting the Heart, high fever, bone-steaming heat, hot jaundice from epidemics, and mouth ulcers. Combined with Sophorae Flavescentis Radix (Kushen), ash of earthworms (Quchong Hui), and Indigo Naturalis (Qingdai)...
[Discussion] For all living things, Qi precedes Flavor. Cold is the Qi of Water; Heat is the Qi of Fire. Drugs with cold Qi and bitter Flavor possess a descending nature and have a purgative effect. Drugs with hot Qi and bitter Flavor possess an ascending nature but still have a purgative effect. However, Yang sends its essence upward, and Yuan Qi is tonified by ascending. This is inferior to Yin-Cold, whose essence descends downward. When combined with a bitter flavor, it becomes a purgative. Gentianae Radix et Rhizoma has a great cold Qi and very bitter flavor; it greatly purges fire and heat within the water element. Therefore, it is used to treat Liver and Gallbladder fire, as well as heat accumulated within dampness. The Liver and Gallbladder are interior-exterior partners and are the abodes of Ministerial Fire. They traverse the Sanjiao along with the Hand Jueyin Pericardium Meridian and Hand Shaoyang Sanjiao Meridian. When disease arises from their connection with the Yin of the Spleen and Kidney below, it manifests as damp-heat; when disease arises from their connection with the Yang of the Lung and Stomach above, it manifests as wind-heat. Various clinical manifestations require distinguishing whether the condition is a primary disease of these meridians or a combined disease before using this herb, either as a chief or assistant ingredient, to ensure appropriateness. In summary, such bitter-cold herbs can treat diseases of Postnatal Qi and Blood, but cannot treat diseases of Prenatal Primordial Yin and Primordial Yang. Even when treating Qi and Blood, they treat conditions of excess manifesting as heat, not conditions of deficiency manifesting as heat. The body's Ministerial Fire is considered Prenatal when located in the Pericardium and Sanjiao, but Postnatal when located in the Liver and Gallbladder. The Postnatal relies on the Prenatal for generation, and the Prenatal relies on the Postnatal for completion. If Postnatal Qi and Blood diseases affect the Prenatal, sometimes Gentianae Radix et Rhizoma must be included. (Only the Liver and Gallbladder represent the Postnatal Ministerial Fire, so they often interact pathologically and therapeutically with the Earth element of the Center; see the entry for Picrorhizae Rhizoma under Hu Huanglian.) If one purges the Postnatal Ministerial Fire excessively, it may damage Gu Qi (Grain Qi/Spleen-Stomach Qi), which would hardly benefit the Liver. Therefore, users must exercise caution.
Mr. Miao stated: Gentianae Radix et Rhizoma is great cold and purely Yin, capable of clearing excess heat. Individuals with deficient Stomach Qi and scant Blood should not underestimate it, nor should they take it on an empty stomach, as it may cause urinary incontinence due to its excessive bitterness and overly strong downward purging action.
[Processing] Scrape off the rootlets and soil with a copper knife, chop finely. Soak in Licorice water overnight, then dry in the sun. For deficient individuals, stir-fry with wine until blackened before use.