艾叶，味苦，气温，阴中之阳，无毒。世人俱以蕲艾为佳。然野艾佳于蕲艾。盖蕲艾乃
九牛
草也，似艾而非艾，唯香过于艾，而功用殊不若野艾。入脾、肾、肺三经。祛寒气而逐湿痹
，安疼痛而暖关元。胎漏可止，胎动可安，月经可调，子宫可孕，且炙经穴，可愈百病，无
如世人舍近而求远，舍贱求贵，为可叹耳。
或问艾叶，取野而不取蕲，前人已论之，但未言野艾之何以佳于蕲艾耳？夫蕲艾依种而
生者
，野艾则天然自长于野者也，得天地至阳之气，故能逐鬼而辟邪，祛寒而散湿，其功实胜于
蕲艾药，何舍此而取彼哉。十年之疾，求三年之艾，大抵即野艾，非取乎蕲也。但野艾实妙
，余启冠而肩膊患风痛，用野艾而愈。
地榆，味苦、酸，气微寒，阴中阳也，无毒。止妇人赤带、崩下及月经不断，却小儿疳
热，
止热痢，下瘀血，治肠风下血，愈金疮。但治热而不治寒，虚寒之人，不可轻用地榆凉血之
品也。血热病，生用之凉血，正得其宜。然而血热则必动，动则必有散失之虞。血寒则又凝
，凝则必有积滞之患。过用地榆以凉血，则热变为凉，而阴寒结于肠胃，将腹痛之症生，反
致血崩下血而不可止，犹以为地榆之少也，更佐之以凉血之药，热必至死亡而后已，良可叹
也！
或问地榆治大肠之血，实有奇功，新久皆可用之否？曰∶不可也。大肠有火，则新旧皆
宜；
无火，则新旧皆忌，此言其常也。大肠前有火而后无火，则前宜而后不宜；久无火而暂有火
，则久当忌而暂不宜忌，此言其变也。审常变而察可否，岂特用地榆一味为然哉。
或问地榆凉大肠之血，单用一味，往往见功，而合用他药，反致无效，何也？盖单用一
味，
则功专而效速，合用他药，未免拘牵矣。倘所用他药尽入大肠之经，则调和于寒热之间，赞
襄气血之中，功既速成，而身亦甚健。惟其所用之他药，非尽入于大肠经之味，则彼此异宜
，上下违背，安能奏功乎。可见用药贵纯而不贵杂，不在单用与不单用也。
或疑地榆凉血，何以能止也？不知地榆亦能补血也，倘徒凉血，则血正不能骤止，惟其
凉血
又兼补血，所以单味亦成功耳。
艾叶，味道苦，性质温热，属于阴中之阳，没有毒性。世人都认为蕲艾是最好的。然而野生的艾比蕲艾更好。因为蕲艾是“九牛草”，形状像艾但不是真正的艾，只是香味比艾更浓，但功效却远不如野艾。它进入脾、肾、肺三经。能驱除寒气并驱逐湿痹，缓解疼痛并温暖关元穴。胎漏（妊娠期阴道出血）可以停止，胎动不安可以安定，月经可以调顺，子宫可以受孕，而且艾灸经络穴位，可以治愈百病，无奈世人舍近求远，舍廉价而追求昂贵，真是令人叹息。
有人问：艾叶，为什么取用野艾而不取用蕲艾？前人已经论述过，但没有说明野艾为什么比蕲艾好。那些依种植而生长的蕲艾，野艾则是天然生长在野外的，得天地至阳之气，所以能驱鬼辟邪，祛寒散湿，其功效确实胜过蕲艾药，为什么要舍弃这个而选择那个呢？“十年之疾，求三年之艾”，大抵指的就是野艾，而不是指蕲艾。只是野艾确实奇妙，我刚开始戴帽子时肩膊患风痛，使用野艾就痊愈了。
地榆，味道苦、酸，气微寒，属于阴中阳，没有毒性。能止住妇女赤带、崩漏及月经不断，消除小儿疳热，止住热痢，下瘀血，治疗肠风下血，治愈金疮（刀箭等金属利器造成的创伤）。但是只治热证不治寒证，虚寒体质的人，不可轻易使用地榆这种凉血的药物。血热病，生用地榆来凉血，正得其宜。然而血热则必妄行，妄行则必有散失的忧虑。血寒则又凝结，凝结则必有积滞的祸患。过度使用地榆来凉血，则热变为凉，导致阴寒结于肠胃，将产生腹痛的症状，反而导致血崩下血而无法止住，还认为是地榆用量太少，更辅助以凉血药物，热证必定导致死亡才罢休，实在令人叹息！
有人问：地榆治疗大肠的血证，确实有奇功，新病和久病都可以使用吗？回答说：不可以。大肠有火，则新旧病都适宜；无火，则新旧病都忌讳，这是说常理。大肠前阶段有火而后阶段无火，则前期适宜而后期不适宜；长期无火而暂时有火，则长期应当忌讳而暂时不宜忌讳，这是说变通。审察常理与变通而考察是否可用，难道仅仅是用地榆这一味药如此吗？
有人问：地榆凉大肠的血，单用一味药，往往见效，而配合其他药物，反而无效，为什么呢？大概单用一味药，则功效专一而见效快，配合其他药物，未免受到牵制。如果所用的其他药物全部进入大肠经，则在寒热之间调和，在气血之中赞助，功效既快速完成，身体也很健康。只有当所用的其他药物，并非全部进入大肠经的药物，则彼此适宜性不同，上下违背，怎么能奏效呢。可见用药贵在纯粹而不贵在杂乱，不在于单用还是不单用。
有人怀疑地榆凉血，怎么能止血呢？不知道地榆也能补血啊，如果仅仅凉血，则血正不能骤然止住，只有它凉血又兼补血，所以单味药也能成功。
Mugwort Leaf (Ai Ye), bitter in taste, warm in nature, is yang within yin, and non-toxic. The world generally considers Qiai (Qingdao Mugwort) to be the best. However, wild mugwort is superior to Qiai. This is because Qiai is a "nine-ox grass," resembling mugwort but not true mugwort; its fragrance is stronger than that of mugwort, yet its therapeutic efficacy is far inferior to that of wild mugwort. It enters the Spleen, Kidney, and Lung meridians. It dispels cold qi and drives out damp-bi (painful obstruction due to wind-cold-dampness), alleviates pain, and warms the Guanyuan (CV 4) acupoint. It can stop fetal leakage (vaginal bleeding during pregnancy), calm fetal restlessness, regulate menstruation, enable conception in the uterus, and moxibustion on meridian acupoints can cure hundreds of diseases. Alas, it is lamentable that people abandon what is near for what is distant, and cheap for expensive.
Someone asked: Regarding Mugwort Leaf, why choose wild mugwort over Qiai? Predecessors have discussed this, but did not explain why wild mugwort is superior to Qiai. Qiai grows through cultivation, whereas wild mugwort grows naturally in the wild, obtaining the supreme yang qi of heaven and earth. Thus, it can expel evil spirits and ward off pathogenic factors, dispel cold, and scatter dampness. Its efficacy truly surpasses that of Qiai; why abandon this for that? "For a disease of ten years, seek three-year-old mugwort" generally refers to wild mugwort, not Qiai. Wild mugwort is indeed miraculous; when I first began wearing hats, my shoulders suffered from wind-pain, and using wild mugwort cured me.
Sanguisorba Root (Di Yu), bitter and sour in taste, slightly cold in nature, is yang within yin, and non-toxic. It stops leukorrhea with blood (red discharge), metrorrhagia (uterine bleeding), and continuous menstruation in women; eliminates pediatric malnutrition fever (gan heat); stops dysentery due to heat; expels stasis; treats intestinal wind bleeding; and heals metal wounds (trauma caused by sharp instruments). However, it only treats heat patterns, not cold patterns. Individuals with deficiency-cold constitutions should not lightly use Di Yu, a herb that cools blood. For blood-heat conditions, raw Di Yu to cool blood is appropriate. Yet, if blood is hot, it tends to move recklessly; if it moves recklessly, there is a risk of loss. If blood is cold, it congeals; if it congeals, there is a risk of stagnation. Overusing Di Yu to cool blood transforms heat into cold, causing yin-cold to knot in the intestines and stomach, leading to abdominal pain, and conversely causing metrorrhagia and lower tract bleeding that cannot be stopped. One might mistakenly think the dose of Di Yu was too low and add more blood-cooling herbs, resulting in death from heat exhaustion. This is truly lamentable!
Someone asked: Di Yu has miraculous effects on treating blood disorders of the Large Intestine; can it be used for both acute and chronic conditions? The answer is no. If the Large Intestine has fire (heat), it is suitable for both acute and chronic cases; if there is no fire, it is contraindicated for both. This describes the general rule. If the Large Intestine had fire previously but not subsequently, it was suitable before but not now; if it lacked fire for a long time but temporarily has fire, it should have been avoided previously but is not contraindicated temporarily. This describes the variable application. Examining the general rules and variables to determine applicability applies not only to the use of Di Yu alone.
Someone asked: Di Yu cools blood in the Large Intestine; single-use often shows efficacy, but combined with other herbs, it often fails. Why? Using a single herb allows for focused efficacy and rapid effect. Combining it with other herbs may cause constraints. If the other herbs used all enter the Large Intestine meridian, they harmonize between cold and heat and assist qi and blood, achieving rapid results and robust health. However, if the other herbs do not all enter the Large Intestine meridian, their indications differ, and their actions conflict vertically and horizontally, making efficacy impossible. Thus, medication values purity over complexity, whether used singly or in combination.
Some doubt how Di Yu, which cools blood, can stop bleeding. They do not know that Di Yu also tonifies blood. If it merely cooled blood, bleeding could not be stopped abruptly. Because it cools blood while simultaneously tonifying blood, even single-use can succeed.