Library

Gan Jiang (Dried Ginger) is processed from the mother ginger root by peeling it and following specific methods. Its color is yellowish-white, its aroma and taste are pungent and warm, and its texture is firm and compact. It is a specialized medicine for warming the middle jiao (middle energizer, primarily referring to the Spleen and Stomach). In Lizhong Tang (Regulate the Middle Decoction), it is used precisely according to its fundamental dosage and nature. Its property is more dispersing than retaining, thus enabling it to move from the Stomach to the Lungs, possessing the functions of dispelling pathogenic factors, inducing sweating, stopping vomiting, and promoting water metabolism. When stir-fried until black, it also enters the Kidney meridian, but lacks the potent strength of Fu Zi (Aconite Root) and Wu Tou (Henbane Fruit). Whenever Zhang Zhongjing's formulas use Gan Jiang, it invariably pertains to warming the middle jiao; the rationale behind this can be understood through careful study.

Tongmai Sini Tang (Pulse-Reviving Four Reversal Decoction) is essentially Sini Tang (Four Reversal Decoction) with doubled amounts of Gan Jiang. If the pulse remains imperceptible, Ren Shen (Ginseng Root) is added. This might suggest that both Gan Jiang and Ren Shen can unblock the vessels, implying their efficacy extends beyond merely warming the middle jiao. However, "obstructing Ying Qi (Nutritive Qi) so that it has nowhere to avoid is called Mai (Vessels)." Ying Qi originates in the middle jiao, which separates waste products and steams fluids. When diarrhea occurs, the middle jiao fails in its duties, how could the pulse not become faint and nearly imperceptible? To restore the pulse, one must necessarily warm the middle jiao and stop the diarrhea. Only if the diarrhea stops yet the pulse remains absent should one look for causes outside the middle jiao, specifically in the Heart, which governs the blood vessels. Then, adding Ren Shen to tonify the Heart and unblock the vessels does not mean Gan Jiang cannot unblock the vessels, nor does it mean that unblocking vessels is unrelated to warming the middle jiao.

Fei Wei (Lung Withering) may result from dryness-heat or deficiency-cold. For deficiency-cold type Fei Wei, Gancao Ganjiang Tang (Licorice and Dried Ginger Decoction) is used. Saying that Gan Jiang warms the Lungs is indeed correct. But does one not know that Metal (Lungs) is born from Earth (Spleen)? If the Earth is not warm, the upper part (Lungs) will inevitably be deficient. Upper deficiency leads to an inability to control the lower part; thus, dizziness and excessive saliva indicate upper deficiency, while enuresis and frequent urination indicate lower deficiency. All these stem from the lack of warmth in the middle. Therefore, Gan Jiang does warm the Lungs, but it does so by warming the Spleen first rather than bypassing it.

One might ask: In cold damage (Shanghan), if the exterior was mistakenly attacked, and after taking Gancao Ganjiang Tang, the extremities recover warmth, does this not prove that Gan Jiang warms not only the middle but also the lower jiao? The response is: Can Gan Jiang warm the lower jiao directly? Only after processing (pao zhi) can it do so. However, even when processed, its warming qi may not fully penetrate. Administering Shaoyao Gancao Tang (Peony and Licorice Decoction) next allows the penetration to complete, enabling the legs to extend without cramping. The subtlety here is profound and cannot be fully explained in a few words. Floating pulse, spontaneous sweating, restlessness, and slight aversion to cold indicate pathogens in the exterior. Frequent urination and leg cramps indicate Taiyang cold pathogens invading the Shaoyin (Lesser Yin) channel. There may have been latent cold previously, exacerbating the condition. If a physician uses Guizhi Tang (Cinnamon Twig Decoction) solely to attack the exterior, the Sour-Cold nature of Shaoyao (Peony Root) entering the interior increases lower cold, leading immediately to Jue Ni (Reversal Cold/Extremity Cold). The initial restlessness and slight aversion to cold worsen into Kidney cold and agitation. The Yang within Yin, following the outward-expanding force of Guizhi, attempts to escape, causing dry throat and vomiting. At this point, the exterior pathogen causing sweating has been treated by Guizhi Tang. Using Pao Jiang (Processed Ginger) to warm the lower and Zhi Gan Cao (Honey-fried Licorice Root) to harmonize the middle ensures Yang recovery and self-healing. Yet, if the feet warm but cramps persist, is it not because the power to warm the lower jiao is insufficient? However, this is not due to a loss of True Yang, so Fu Zi (Prepared Aconite Root) is unnecessary. Previously misled by Shaoyao, now Shaoyao helps extend the legs. Why? Precisely because Pao Jiang, restrained by Shaoyao, allows Yang to fully recover. Why not continue with Shaoyao Gancao Tang for Fei Wei? Because there is only enuresis and frequent urination, without leg cramps, and Pao Jiang is also intended to warm the Lungs. Thus, if Gan Jiang is not processed, it warms the middle but not the lower jiao.

In various Sini Tang variants treating Shaoyin disease with Gan Jiang, it seems Gan Jiang warms the lower jiao. However, severe Shaoyin cold often insults the Spleen upwards. Using Fu Zi is like cutting down generals and capturing flags (a powerful attack), requiring Gan Jiang as support to store provisions and fortify defenses. In Lizhong Wan (Regulate the Middle Pill), Gan Jiang is used in 3 liang to warm the middle, bearing primary responsibility. In Sini Tang, Gan Jiang is used in 1.5 liang because Fu Zi takes charge of warming Shaoyin, with Gan Jiang acting as rear guard. Observing Shenzhuo Tang (Kidney-Dampness Decoction), where the disease is in the lower jiao but the formula contains Spleen herbs rather than Kidney herbs, further proves that warming the lower jiao necessitates warming the middle jiao.

Sini Tang focuses on Jue Ni (extremity reversal), with Xi Li (diarrhea) as a concurrent symptom; thus, Gan Jiang is present without necessarily needing Cong Bai (Scallion White). Baitong Tang (White Scallion Decoction) treats Shaoyin Xi Li as the primary disease without concurrent symptoms. Without raising Yin Qi to connect with Yang, diarrhea will not cease; hence, Cong Bai is the sovereign herb, assisted by Jiang (Ginger) and Fu Zi. In Taohua Tang (Peach Blossom Decoction), Gan Jiang is used in only 1 liang, a very small amount, and without Fu Zi or Cong Bai. How is this explained? This is not a pure cold syndrome of Shaoyin. Shi Li (Halloysitum Rubrum) and Jing Mi (Rice Grain) secure the lower and harmonize the middle. A slight application of Gan Jiang facilitates warming transformation. It stops diarrhea not by diuresis or clearing blood, but purely by arresting the flow, representing a highly sophisticated method. If Chishi Zhi Yuyuliang Tang (Red Halloysite and Hematite Decoction) fails because it treats lower jiao pathology with middle jiao herbs, then the presence of Gan Jiang in Taohua Tang clearly relates to the central palace (Spleen/Stomach).

Gan Jiang warms the Spleen and reaches the Lungs to treat Lung cough, while connecting downward to the Spleen, fitting appropriately. For example, in Xiao Qinglong Tang (Minor Blue Dragon Decoction), Gan Jiang is used in 3 liang to treat cold cough, and even with mild diarrhea, Gan Jiang is retained.

The Ben Jing (Divine Farmer's Materia Medica) states Gan Jiang stops bleeding. Ren Zhi Zhi Zhi says blood flows freely when heated, so hemostatics usually use cooling herbs. However, in cases of Qi deficiency with cold, where Yin and Yang fail to maintain each other, and Ying Qi is weak and scattered, blood may also circulate erratically. I believe blood belongs to the Spleen and emerges from the middle jiao. For syndromes of weak and scattered Ying Qi, warming the middle jiao is essential. Jiao Ai Tang (Colla Corii Asini and Mugwort Leaf Decoction) in Jin Gui Yao Lue lacks Gan Jiang, but Qian Jin Fang includes it. Huangtu Tang (Yellow Earth Decoction) lacks Gan Jiang, but Zaozhong Huangtu (Stove-heart Yellow Earth) serves a similar function. Gan Jiang warms the middle, inherently possessing hemostatic properties, though auxiliaries are needed. Generally, for persistent epistaxis/hematemesis (upper), suppression is appropriate; for persistent metrorrhagia/menorrhagia (lower), lifting is appropriate. Herbs like Bai Ye (Moss) and E Jiao (Donkey-hide Gelatin) guide blood back to the vessels. Huang Qin (Scutellaria Root) and Tong Bian (Child's Urine) nourish Yin and harmonize Yang, neither suppressing nor lifting. The use of Ma Tong (Horse Dung Juice) in Bai Ye Tang is extraordinary. Horse Qi is vigorous, causing blood to exit via sweat. Among animal substances, most are cold or toxic; only Ma Tong is warm and non-toxic. Though filthy, upon transformation, it aids blood circulation in the vessels and directs flow downward. Assisting Gan Jiang, it acts to suppress bleeding. For women with Xian Jing (Sunken Menses) and black leukorrhea/metrorrhagia not resolving, Jiao Jiang Tang (Colla and Ginger Decoction) is indicated. Black discharge usually indicates heat, but in deficiency-cold, blood coagulating in collaterals can turn purple/black. The Jiang in Jiao Jiang Tang is undoubtedly Gan Jiang. Chen Xiuyuan used these two herbs repeatedly without success, later replacing Gan Jiang with Sheng Jiang (Fresh Ginger) and adding E Jiao and Da Zao (Jujube), resulting in immediate cessation. He stated Sheng Jiang disperses cold and raises Qi, aligning with the principle of lifting sunken conditions, contrasting with Ma Tong's suppression. However, prior Gan Jiang usage likely had merit; perhaps using both Sheng and Gan Jiang together, as per Zhang Zhongjing's method, would yield faster results.

In Zhang Zhongjing's formulas where Gan Jiang and Huang Lian (Coptis Rhizome) are combined, vomiting is always present. Vomiting belongs to Shaoyang (Lesser Yang); thus, the formula must contain Huang Qin (Scutellaria Root) and Ren Shen, specific Shaoyang herbs. Shaoyang is the pivot of the three Yang channels. Huang Lian descends Stomach Yang, while Gan Jiang ascends Spleen Yin. With Spleen ascending and Stomach descending, the Shaoyang pivot turns. This is the treatment for Shaoyang disorders without alternating chills and fever, where the treatment targets one aspect but yields effects in another.