《伤寒论》原文∶伤寒脉滑而厥者，里有热，白虎汤主之。
太阳篇白虎汤证，脉浮滑是表里皆有热也。此节之白虎汤证，脉滑而厥，是里有热表有寒也，此所谓
热深厥深也。愚遇此等证，恒先用鲜白茅根半斤切碎，煮四五沸，取汤一大碗，温饮下，厥回身热，然后
投以白虎汤，可免病家之疑，病患亦敢放胆服药。若无鲜茅根时，可以药局中干茅根四两代之。若不用茅根
时，愚恒治以白虎加人参汤，盖取人参能助人生发之气，以宣通内热外出也。
《伤寒论》原文∶手足厥寒，脉细欲绝者，当归四逆汤主
之。若其人内有久寒者，宜当归四逆加吴茱萸生姜汤。
沈尧封曰∶叔和释脉法，细极谓之微，即此之脉细欲绝，即与脉微相浑。不知微者，薄也，属阳气虚，
细者小也，属阴血虚，薄者未必小，小者未必薄也。盖荣行脉中，阴血虚则实其中者少，脉故小；卫行脉外，
阳气虚则约乎外者怯，脉故薄。况前人用微字，多取薄字意，试问∶“微云淡河汉”，薄乎？细乎？
故少阴论中脉微欲绝，用通脉四逆主治回阳之剂也。此之脉细欲
绝，用当归四逆主治补血之剂也。两脉阴阳各异，岂堪混释！
【当归四逆汤方】当归三两，桂枝三两去皮，芍药三两，细
辛三两，大枣二十五枚擘，甘草二两炙，通草二两。
上七味，以水八升，煮取三升，去滓，温服一升，日三服。
【当归四逆加吴茱萸生姜汤方】即前方加吴茱萸二升，生姜半斤切，以水六升、清酒六升，和煮取
五升，去滓，分温五服。
王和安曰∶厥阴经气来自足少阴经，宣于手太阴经，成循环不息之常度。若以血寒自郁于脏，脉象应有
弦凝之征。今脉细欲绝，可知少阴经气来源先虚，及复本经受脏寒之感，则虚寒转甚，细而欲绝也。治以当归
四逆汤，意在温肝通郁，而必以桂枝、白芍疏浚经气之源，细辛、通草畅达经气之流，内有凝寒，重加吴
萸、生姜，温经通气，仍加入原方以全其用，解此，则治经气之定义可三反矣。
Original text from *Shanghan Lun*: In cases of cold damage where the pulse is slippery and there is cold extremities (Jue, 厥), it indicates internal heat, which should be treated with Baihu Tang (White Tiger Decoction).
In the Taiyang chapter, the Baihu Tang syndrome presents with a floating and slippery pulse, indicating heat in both the exterior and interior. In this section, the Baihu Tang syndrome presents with a slippery pulse and cold extremities, indicating internal heat and external cold; this is what is referred to as "the deeper the heat, the deeper the cold extremities" (Re Shen Jue Shen, 热深厥深). When I encounter such syndromes, I often first use half a jin (approx. 500g) of fresh Baomao Gen (Imperata Rhizome, 白茅根), chopped, boiled for four or five boils, and taken as one large bowl of decoction warm. Once the cold extremities resolve and body heat returns, then Baihu Tang is administered. This can dispel the doubts of the patient's family, allowing the patient to take the medicine with confidence. If fresh Baomao Gen is unavailable, four liang (approx. 120g) of dried Baomao Gen from the pharmacy can be used as a substitute. If Baomao Gen is not used, I often treat with Baihu Jia Renshen Tang (White Tiger Decoction plus Ginseng), taking advantage of Renshen (Ginseng Root, 人参) to assist the body's generating qi to vent and disperse the internal heat outward.
Original text from *Shanghan Lun*: With cold hands and feet and a fine pulse nearly imperceptible (Xi Yu Jue, 细欲绝), Danggui Sini Tang (Angelica Sinensis Decoction for Extremity Cold, 当归四逆汤) is indicated. If the person has chronic internal cold, Danggui Sini Jia Wuzhuyu Shengjiang Tang (Danggui Sini Decoction plus Evodia and Fresh Ginger, 当归四逆加吴茱萸生姜汤) is appropriate.
Shen Yaofeng stated: He Suhe (Wang Shuhe, 王叔和), in interpreting pulse methods, defined an extremely fine pulse as Wei (Micro, 微). Thus, this "fine pulse nearly imperceptible" is confused with the Wei pulse. One must understand that "Wei" refers to thinness, belonging to Yang Qi deficiency; "Xi" (Fine, 细) refers to smallness, belonging to Yin Blood deficiency. Thinness does not necessarily imply smallness, and smallness does not necessarily imply thinness. Ying Qi (Nutritive Qi, 营) circulates within the vessels; when Yin Blood is deficient, there is less substance filling the vessels, so the pulse appears small. Wei Qi (Defensive Qi, 卫) circulates outside the vessels; when Yang Qi is deficient, the force constraining the exterior is weak, so the pulse appears thin. Moreover, predecessors often used the character "Wei" to mean "thin." Consider the phrase "Wei clouds faintly cover the Milky Way"; is it thin or fine? Therefore, in the Shaoyin chapter, a Wei pulse nearly imperceptible is treated with Tongmai Sini Tang (Pulse-Reviving Four Reversal Decoction, 通脉四逆汤), a formula to restore Yang. Here, a Xi pulse nearly imperceptible is treated with Danggui Sini Tang, a formula to nourish Blood and unblock collaterals. These two pulses differ in their Yin-Yang nature; how can they be conflated!
[Danggui Sini Tang Formula] Danggui (Angelicae Radix Sinensis, 当归) three liang, Guizhi (Cinnamomi Ramulus, 桂枝) three liang, peeled, Shaoyao (Paeoniae Radix Alba, 芍药) three liang, Xixin (Asari Radix et Rhizoma, 细辛) three liang, Dazao (Zizyphi Fructus, 大枣) twenty-five pieces, split, Gancao (Glycyrrhizae Radix et Rhizoma Praeparata cum Melle, 甘草) two liang, honey-fried, Tongcao (Tetrapanacis Medulla, 通草) two liang.
The above seven ingredients are boiled in eight sheng (approx. 1600ml) of water to obtain three sheng of decoction. The dregs are removed, and one sheng is taken warm, three times daily.
[Danggui Sini Jia Wuzhuyu Shengjiang Tang Formula] This is the preceding formula plus Wuzhuyu (Evodiae Fructus, 吴茱萸) two sheng, and Shengjiang (Zingiberis Rhizoma Recens, 生姜) half a jin, chopped. It is boiled with six sheng of water and six sheng of clear wine to obtain five sheng of decoction. The dregs are removed, and the decoction is divided into five warm doses.
Wang He'an stated: The Qi of the Jueyin Meridian originates from the Foot-Shaoyin Meridian and disseminates through the Hand-Taiyin Meridian, forming a continuous cycle. If blood-cold stagnates internally within the Zang organs, the pulse image should show characteristics of string-tightness and coagulation. Now, since the pulse is fine and nearly imperceptible, it can be known that the source of Qi from the Shaoyin Meridian was initially deficient. Subsequently, contracting cold from the affected meridian and organ exacerbates the deficiency-cold, resulting in a fine pulse nearly imperceptible. Treatment with Danggui Sini Tang aims to warm the Liver and unblock stagnation. However, Guizhi and Baishao must be used to dredge the source of meridian Qi, while Xixin and Tongcao must be used to facilitate the flow of meridian Qi. For internal coagulated cold, larger amounts of Wuzhuyu and Shengjiang are added to warm the meridians and promote Qi circulation. The original formula components are retained to preserve its complete efficacy. Understanding this allows one to repeatedly deduce the principles of treating meridian Qi disorders.