一名天水散。治夏时中暑。热伤元气。内外俱热。无气以动。烦渴欲饮。肠胃枯涸者。
又能催生。下乳积聚水蓄。里急后重。暴注下迫者宜之。加朱砂三钱。名益元散。
六一散中滑石甘。热邪表里可兼探。（滑石六两甘草一两为末。灯心汤下。亦有用新汲
水下者。）益元（散。）再入朱砂研。（加朱砂三钱。名益元散。）泻北元机在补南。
柯韵伯曰。元气虚而不支者死。邪气盛而无制者亦死。今热伤元气。无气以动。斯时用
参以补气。则邪愈甚。用苓连以清热。则气更伤。惟善攻热者。不使丧人元气。善补虚者。
不使助人邪气。必得气味纯粹之品以主之。滑石禀土冲和之气。能上清水源。下通水道。荡
涤六腑之邪热。从小便而泄矣甘草禀草中冲和之性。调和内外。止渴生津。用以为佐保元气。
而泻虚火。则五脏自和矣。然心为五脏主。暑热扰中。神明不安。必得朱砂以镇之。则神气
可以遽复。凉水以滋之。则邪热可以急除。此补心之阳。寒亦通行也。至于热利初起。里急
后重者宜之。以滑可去着也。催生下乳积聚蓄水等症。同乎此义。故兼治之。是方也。益气
而不助邪。逐邪而不伤气。不负益元之名矣。宜与白虎生脉三方。鼎足可也。
○泄可去闭（邪盛则闭塞不通。必以泄剂。从大便逐之。）
Also known as Tianshui San (Heavenly Water Powder). It treats heatstroke during summer. Heat pathogen damages the Yuan Qi (Original Qi), causing heat in both the exterior and interior, leading to Qi deficiency with lack of energy to move, irritability, thirst with desire to drink, and dryness/depletion of the intestines and stomach.
It can also induce labor, promote lactation, resolve accumulations, and drain water retention. It is suitable for cases with tenesmus (urgency and straining at stool) and sudden profuse watery diarrhea with urgent defecation. Adding three qian of Cinnabar (Zhusha) changes its name to Yiyuan San (Benefiting Origin Powder).
In Liuyi San, Talcum (Huashi) is sweet [and cold]; it can address heat pathogens in both the exterior and interior. (Talcum six liang and Licorice Root (Gancao) one liang are ground into powder. Taken with a decoction of Juncus Arvensis (Dengxincao). Some use fresh drawn cool water.) In Yiyuan San, add Cinnabar (Zhusha) and grind. (Adding three qian of Cinnabar changes its name to Yiyuan San.) To drain the Northern [Water/Kidney] mechanism lies in nourishing the Southern [Fire/Heart].
Ke Yunbo said: Those whose Yuan Qi is deficient and cannot sustain themselves will die; those whose pathogenic factors are excessive and uncontrolled will also die. Now, heat damages the Yuan Qi, resulting in Qi deficiency and inability to move. At this time, using Ginseng (Renshen) to tonify Qi would make the pathogen more severe; using Scutellaria Root (Huangqin) and Phellodendron Bark (Huanglian) to clear heat would further injure the Qi. Only those skilled in attacking heat do so without causing loss of the person's Yuan Qi; those skilled in tonifying deficiency do so without assisting the pathogenic factor. One must obtain substances with pure aroma and flavor to serve as the principal agent. Talcum inherits the harmonious Qi of Earth; it can clear the source of water from above and unblock the water passages below, sweeping away the pathogenic heat of the Six Fu Organs, which is excreted via urination. Licorice Root inherits the harmonious nature among herbs; it harmonizes the interior and exterior, stops thirst, and generates fluids. Used as an assistant to protect the Yuan Qi and drain deficient fire, the Five Zang Organs will naturally harmonize. However, the Heart is the master of the Five Zang Organs. Summer-heat disturbs the middle, causing the Shen (Spirit) to be unsettled. It requires Cinnabar to anchor it, so that the Shen-Qi can quickly recover. Using cool water to nourish it allows the pathogenic heat to be urgently eliminated. This tonifies the Yang of the Heart, allowing even cold to circulate freely. As for early-stage heat dysentery with tenesmus, this formula is suitable because slippery agents can remove adherence/stagnation. Conditions such as inducing labor, promoting lactation, resolving accumulations, and water retention follow the same principle. Therefore, it treats them concurrently. This formula tonifies Qi without aiding the pathogen, expels the pathogen without injuring the Qi, living up to the name "Yiyuan" (Benefiting Origin). It deserves to stand alongside Baihu Tang (White Tiger Decoction) and Shengmai San (Generate Pulse Powder) as a tripod.
○ The purgative method can remove obstruction (When pathogenic factors are excessive, obstruction and blockage occur; one must use purgatives to drive them out through the large intestine.)