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The flavor is sweet and neutral, non-toxic. It treats internal bleeding in the heart and abdomen, a condition of extreme fatigue presenting with chills resembling malaria, pain in the lower back and abdomen, soreness and pain in the four limbs, abnormal uterine bleeding in women, calms the fetus, and long-term consumption lightens the body and benefits Qi.

(Shandong Yanzhou Prefecture, the ancient Dong'e County area has the A Well. Drawing water from it to decoct black donkey skin into gelatin gives it the name Ejiao (Donkey-Hide Gelatin). This is the clear Ji River water, which runs underground for a thousand li before emerging at this well. The Ji River is one of the Four Great Rivers, internally corresponding to the Heart. There are official residences guarding the well; the water is extracted and boiled to produce gelatin for the imperial treasury, hence genuine Ejiao is hard to obtain, and most sold on the market are counterfeit. Genuine Ejiao is dark green, bright, clean, and odorless. Popular taste favors black like lacquer. Therefore, forgers boil cowhide with ordinary water to make gelatin, mixing it with black bean juice; it smells foul and has a turbid texture, making it unsuitable for medicinal use.)

(The *Bencao Chengya* states: The Dong'e Well is located 60 li northeast of Yanggu County, Yanzhou Prefecture, Shandong, which is the ancient Dong'e County. The *Commentary on the Water Classic* states: The Dong'e Well is as wide as a wheel and six or seven zhang deep. The water flows downward, is clear and heavy, and is annually boiled into gelatin for tribute. The boiling method requires taking black donkey skin, scraping it clean and removing hair, soaking it in fast-flowing water for seven days, placing it in a porcelain pot, gradually adding A Well water, and boiling for three days and nights until the skin dissolves. It is filtered clear and boiled again until thick and sticky, then stored in basins to form. It dries easily in winter, appearing deep green, bright, light, and brittle, with a faint and sweet taste. It must be aged for a long time before being suitable for medicinal use. If cowhide, Huangming Jiao (Yellow Clear Gelatin), or other mixed substances are used, they must absolutely not be used.)

(I once personally visited Dong'e to inquire about gelatin production. Upon detailed investigation, I heard that the Ejiao sold there uses not only mixed hides from cattle, horses, and other livestock, but also old box fragments, broken leather from saddles, bridles, boots, and shoes—all damaged and old leather serves as material. Since people favor black color, horse feed and bean juice are added to darken it. To mask the foul odor, camphor and other fragrances are added to confuse the smell. However, good and bad qualities are still easy to distinguish. Now, forgers have become increasingly skillful. Although old leather is soaked and washed for a long time to remove all odor, and then boiled without adding bean juice or any fragrances, it closely resembles the genuine product. People say genuine Ejiao is rare, but actually, genuine Ejiao is not inherently rare; it is merely that counterfeit products are mixed and displayed, causing suspicion even towards genuine ones. People also doubt the variation in color between yellow and black. Gelatin boiled in winter may be tender; in spring, tender gelatin is difficult to solidify, so the decoction must be reduced further (aged). Tender gelatin is yellow, while aged gelatin is black; this is the distinction. Ancients considered gelatin shiny like lacquer and oily-green colored as genuine, but this did not cover all aspects. They also stated: Genuine Ejiao shatters when tapped. Shattering upon tapping applies only to extremely aged Ejiao; how can new Ejiao have this property? Regarding the claim that genuine Ejiao has absolutely no odor and is not too soft in summer, modern counterfeits often exhibit these traits as well, so one cannot determine quality solely based on this. I also heard of an ancient method: first soaking the skin in Wild Wolf Creek water, then boiling it with A Well water. Wild Wolf Creek originates from Hongfan Spring; its nature is Yang, while A Well water's nature is Yin, reflecting the principle of Yin-Yang coordination. It was boiled with mulberry wood fire for four days and nights. It is also said: Rice wine (Baijiu) is strictly forbidden for those consuming gelatin, and one must strongly avoid it. These are points not previously mentioned by predecessors, so I record them here.)

Ejiao is a herb that tonifies the Heart and Lungs. The Heart corresponds to the Ji River; its water is clear and heavy, its nature tends downward, clearing Heat of the Heart Master and descending to interact with Yin. The Lungs correspond to skin and hair; donkey skin addresses deficiency of Lung Qi and enters internally into the muscles. Furthermore, the donkey belongs to the Horse category, which is associated with Fire. One must use black donkeys, embodying the meaning of Water and Fire interacting harmoniously. "Beng" means falling or miscarriage. "Internal Beng in the heart and abdomen" refers to blood of the Pericardium failing to circulate in the meridians, sinking into the abdomen and falling. Ejiao benefits the blood of the Heart Master, thus treating internal Beng in the heart and abdomen. "Lao Ji" refers to extreme exhaustion. "Sasha ru nue zhuang" describes a sensation of chills resembling malaria due to Qi deficiency from extreme fatigue affecting the skin and hair. Ejiao benefits the Qi of the Lung Master, thus treating Lao Ji with chills resembling malaria. Extreme fatigue leads to lower back and abdominal pain. Chills resembling malaria lead to soreness and pain in the four limbs. Internal Beng leads to abnormal uterine bleeding in women. The Heart governs Blood, the Lungs govern Qi; when Qi and Blood are harmonious, the fetus is naturally secured. By tonifying the Heart and Lungs, long-term consumption lightens the body and benefits Qi.

(Note: The *Ling Shu · Jing Shui* chapter states: Hand-Shaoyin externally corresponds to the Ji River and internally belongs to the Heart. Yin'an's theory that the Heart corresponds to the Ji River is likely based on this. Li Zhongzi stated: The *Nei Jing* regards the Ji River as the Liver of Heaven and Earth, therefore Ejiao has many effects on the Liver. This is likely a misrecorded statement.)