Lu Xuan Gong collected medical prescriptions in Zhongzhou to pass the days. This was not merely to use this as a means to avoid disaster, but rather because a gentleman's intention and conduct are applied to the utmost extent in all things. Distinguished scholars of previous generations were often skilled in medicine; this was not only for self-preservation but also to benefit others. However, people nowadays feel ashamed to speak of it. Recently, medical collections such as *Jisheng Fang* (Prescriptions for Saving Lives) or *Jiyan Fang* (Collected Proven Prescriptions) kept by scholar-officials have circulated widely, reflecting the benevolent intentions of virtuous men. Single-herb prescriptions from the Materia Medica have already been printed in Siming and in the collected works and miscellaneous essays of various literati of our dynasty. There are many famous prescriptions, yet none have been categorized and transmitted. I have repeatedly wished to do so, regretting that my collection is not extensive enough. If someone could adopt my advice to compile and transmit these to the public, it would be one way to benefit beings.

The *Huainanzi* states: "Shennong began tasting the flavors of hundreds of herbs. At that time, he suffered poisoning seventy times a day." The *Shiben* states: "Shennong harmonized medicines to save people, thus the hundred medicines originated with Shennong." The *Shiji* claims that Fuxi tasted the flavors of hundreds of herbs, which is incorrect. Tao Hongjing of the Liang Dynasty wrote in his preface to the *Materia Medica*: "Shennong ruled the world, promoted the use of drugs to treat diseases, and saved those suffering from premature death and injury." The *Gao Shi Xiaoshi* states: "Yandi (Flame Emperor) tasted hundreds of medicines to treat illnesses. During the tasting, he experienced near-death experiences a hundred times and survived a hundred times." The *Diwang Shiji* states: "Yandi tasted the flavors of plants and trees, promoted the use of drugs to treat diseases, and authored four volumes of *Bencao* (Materia Medica)." By the time of Tao Hongjing in the Liang Dynasty and Li Shimin et al. in the Tang Dynasty who annotated and narrated, it expanded to twenty volumes. It was re-collated during the Kaibao era of our dynasty. In the Jiayou era of Emperor Renzong, Zhang Yuxi et al. were ordered to categorize and collect explanations of drugs from various schools into the *Supplemented Annotated Materia Medica*. The *Book of Tang*, Biography of Yu Zining, records: "Yu Zining said that Ban Gu only recorded the *Huangdi Neijing* (Yellow Emperor's Inner Canon) but did not record the *Bencao*. The *Qilu* (Seven Catalogs), however, mentions the *Bencao*." People believe that Shennong tasted herbs before the Yellow Emperor, and the texts were not transmitted in written form but passed down orally until Tongjun and Leigong recorded them in chapters. However, the commanderies and counties mentioned are mostly from the Han Dynasty. Zhang Zhongjing and Hua Tuo altered and recorded some of its content. Tao Hongjing of the Liang Dynasty believed this book should be similar to the *Suwen* (Basic Questions); the rest of the views are largely consistent with Yu Zining's statements. (From *Shiwu Jiyuan*)

Medicines are classified into Sovereign (Jun), Minister (Chen), Assistant (Zuo), and Guide (Shi). Generally, medicines that nourish life serve as Sovereign; medicines that nourish nature serve as Ministers; medicines that treat diseases serve as Assistants and Guides. This is akin to carefully considering and using them based on their inherent properties, which is beneficial.

The *Qianjin Fang* states: "Accumulations of various diseases arise from deficiency; deficiency gives rise to a hundred diseases. 'Ji' (accumulation) refers to disorders of the five zang organs, while 'Ju' (gathering) refers to disorders of the six fu organs. For such diseases, old prescriptions are generally used without modification. However, for deficiency-fatigue (Xu Lao), the complications are myriad, and one should adjust the prescription according to the disease. One must carefully examine the cold or heat patterns and record the main herbs added or removed. For deficiency-fatigue with headache and fever, add Gouqi (Lycium Fruit) and Weiru (Polygonatum Rhizome); for deficiency with nausea/vomiting, add Renshen (Ginseng Root); for deficiency with restlessness, also add Renshen; for deficiency with frequent dreams, add Longgu (Fossilized Bones); for deficiency with excessive heat, add Dihuang (Rehmannia Root), Muli (Oyster Shell), Difuzi (Kochia Fruit), and Gancao (Licorice Root); for deficiency with cold, add Danggui (Angelica Sinensis Root), Xiong (Ligusticum Rhizome), and Jiangjiang (Dried Ginger); for deficiency with depletion, add Zhongru (Stalactite), Cila (Thorn), Rongrong (Cistanche Stem), and Bajitian (Morinda Root); for deficiency with severe heat, add Huangqin (Scutellaria Root) and Tianmendong (Asparagus Tuber); for deficiency with forgetfulness, add Fushen (Poria with Pine Root) and Yuanzhi (Polygala Root); for deficiency with palpitations and unrest, add Longchi (Dragon Teeth), Shashen (Adenophora Root), Zi Shiyun (Purple Quartz), and Xiaocao (Herba Siegesbeckiae - if cold, use Zi Shiyun and Xiaocao; if exogenous heat, use Shashen and Longchi; if neither cold nor heat, use both); for deficiency with dry mouth, add Maidong (Ophiopogon Tuber) and Zhimu (Anemarrhena Rhizome); for deficiency with rapid breathing, add Huma (Sesame Seed), Fupenzi (Rubus Fruit), and Baiziren (Platycladus Seed); for deficiency with excessive qi and slight cough, add Wubeizi (Schisandra Fruit) and Dazao (Jujube); for deficiency with stiff body and lumbar discomfort, add Cishi (Magnetite) and Duzhong (Eucommia Bark); for deficiency with excessive cold, add Guixin (Cinnamon Twig), Wuzhuyu (Evodia Fruit), Fuzi (Aconite Lateral Root), and Wutou (Aconite Root); for deficiency-fatigue with red urine, add Huangqin; for deficiency with exogenous heat, add Digupi (Lycium Bark) and Baishuihuang (Yellow Coptis from Baishui place name); for deficiency with cold, use Longxi Huang (Yellow Coptis from Longxi); for deficiency with phlegm and qi rebellion, use Shengjiang (Fresh Ginger), Banxia (Pinellia Tuber), and Zhishi (Bitter Orange Fruit); for deficiency with hyperactive small intestine function, add Sangpiaoxiao (Mantis Egg Case), Longgu, and Jinji Nei-Jin (Chicken Gizzard Lining); for deficiency with impaired small intestine function, add Fuling (Poria) and Zexie (Alisma Rhizome); for deficiency with depletion and white urine, add Houpo (Magnolia Bark). These medicines are not listed for exhaustive use, but rather to illustrate a corner of the principle of addition and subtraction based on the constitution's cold/heat characteristics. Prescribers should follow this guideline."