Library

Qianshuang (Lead Frost), also known as Qianbaishuang (Lead White Frost).
Sweet, sour, and cold in nature. It can descend phlegm, clear heat, settle fright, and stop diarrhea, possessing remarkable efficacy; however, it is not a substance suitable for long-term or daily use. For diseases located in the Upper Jiao (Upper Burner), this herb is appropriate for clearing and settling.
The preparation method involves placing raw vinegar in an earthenware basin, suspending iron strips horizontally across the basin so they are two cun above the vinegar surface, covering it with another earthenware basin, and placing it in a shady location until crystals form.

This is Fenxi (Powder Tin), also known as Hufen (Hu Powder) or Shuifen (Water Powder).
It is incompatible with Realgar (Xihuang) and can be used to control Sulfur (Liuhuang).
Pungent and cold. Enters the Qi level of the Foot-Shaoyin Kidney Meridian. It calms the heart and settles the spirit, descends phlegm and resolves masses, kills parasites, stops dysentery, treats sores, and induces sweating. Mixed with scallion juice and formed into pills, it treats women's [illnesses]; taken warm with juice extracted from millet, it treats "bie zha" (abdominal mass resembling a turtle). Combined with Coptidis Rhizoma (Huanglian), it is applied externally to treat lip sores found at swallow nests. When boiled with salt until the color changes, it is rubbed on children with abdominal distension and bluish discoloration of the abdominal skin. (In cases of regurgitation, vomiting, and hiccups, this indicates floating fire and impending separation of Yin and Yang. By combining this settling agent with Yin-nourishing formulas, the floating fire returns to its origin, and the vomiting ceases.)

Qiandan (Lead Tetroxide), also known as Ludi (Furnace Bottom Residue).
It is incompatible with Arsenic Trioxide (Pi). It can be processed using Stellariae Radix (Yelangedou) and Sulfur (Liuhuang).
Pungent and slightly cold. Its flavor carries salty and bitter qualities, and it enters the Blood level. Internal use: Descends phlegm and dispels timidity. Treats epilepsy, mania, vomiting, and regurgitation; eliminates accumulations and kills parasites; treats infantile malnutrition (Gan disease), dysentery, and malaria. External use: Clears heat and draws out toxins, promotes flesh regeneration, removes necrotic tissue, treats malignant sores and swelling/toxicity, and is used in plasters, making it an essential herb for external medicine. Mixed with carp bile and applied to the eyes, it treats pterygium (fleshy growth over the cornea). Combined with Coptidis Rhizoma (Huanglian) and stir-fried into pills, it treats bloody and white dysentery. Combined with Jiancha (Jian Tea) powder and taken with wine, it treats malaria. Taken with honey water, it treats pediatric summerheat malaria.
Wash with water, let settle, dry, and stir-fry over mild heat until purple before use.

Ludi (Furnace Bottom Residue), the residue from refining Qiandan.
Must be processed with Stellariae Radix (Yelangedou).
Salty, pungent, and neutral. Slightly toxic. Travels to the Lower Jiao (Lower Burner); descends phlegm, settles fright, reduces swelling, and kills parasites. Treats five types of hemorrhoids and metallic trauma wounds. Mixed with tung oil and applied as a plaster, it treats bone abscesses. Combined with Angelicae Dahuricae Radix (Baizhi) and candle wax oil, it is applied to sores growing inside the nose. Combined with tea and taken orally, it treats aphonia caused by fright. (When fright qi invades the collaterals of the Heart...) Supplement with Cnidii Fructus (Shechuangzi) for external application to treat damp itching in the genital area. Mixed with water and applied, it treats acne scars.
Raw material ground into powder and sprinkled on newborn infants presenting with blister-like lesions all over the body (resembling fish bladders or crystal, leaking fluid upon rupture and recurring), while simultaneously administering Suhexiang Wan (Styrax Pills).
Grind into powder, place in a porcelain pot, cover with thick paper bags, add willow borer debris and roast, then fill with running water from the east, boil over fire for one shichen (two hours), remove willow debris and paper bags, and use. This drug is difficult to obtain authentically. If it is the residue formed from smelting silver, it corrodes various substances and should not be taken internally; it is only suitable for external application.