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Rongyan (Military Salt) is piled in mounds, cut into shapes resembling pillows. It is fine and white in texture, with a sweet and salty taste. Its efficacy lies in resolving blood stasis. It enters the Kidney meridian and treats redness due to blood stasis, dryness, and blurred vision in the eyes.

This substance is originally called Huangdan (Lead Tetroxide), which is formed by smelting lead, employing a distinct method. The *Tang Bencao* commentary states: "It is made by roasting tin." However, since the classics refer to it as Qiandan (Lead Tetroxide), the claim that it is made from roasted tin is erroneous and not difficult to refute. This is because tin has a dull, dark color, whereas lead is bright and clear; this difference serves as the distinction. It is used to treat malaria and long-standing accumulations.

Fenxi (Basic Lead Carbonate), also known as Hufen, or Dingfen. It stops diarrhea, dysentery, accumulations, and chronic dysentery.

Qianshuang (Lead Frost). The *Tujing* has already documented its preparation method. It treats heat-phlegm obstruction in the upper jiao. When applied to papaya, it removes the sour taste, based on the principle of Metal overcoming Wood.

Ancient bronze coins, scorched until red, are toxic. They are used to treat turbid stasis in the eyes, corrode necrotic flesh, assist in difficult childbirth (transverse presentation), and are frequently used for the five types of strangury. It is incorrect to say this is merely because they contain tin. Currently, only those from the Jingwang period such as Daquan Wushi and Bao Huo coins, Qin Banliang coins, Han Jiaqian coins, large and small Wu Zhu coins, Wu Daquan Wubai and Daquan Dangqian coins, Song Sizhu and Er Zhu coins, Liang Sizhu coins, and Northern Qi Changping Wu Zhu coins are selected. There are many subsequent varieties, but only these types are suitable for use. In my youth, I suffered from acute red eye swelling and pain, unable to open my eyes for several days. A guest advised me to take a piece of fresh ginger, wash and peel it, scrape ginger juice using an ancient bronze coin, and apply it directly onto the edge of the coin to dab the affected area. Initially, it was very bitter, causing hot tears to stream down my face. However, ultimately, there was no damage. Later patients were taught this method but often harbored doubts. Those who believed and applied it invariably achieved success. One application led to recovery; it should not be repeated. It is contraindicated for those with sores.

Modern physicians absolutely do not use this method. For this reason, merchants do not traffic in them for profit, and physicians consequently abandon their use. Furthermore, they are only produced in Shu Commandery, and even then, not abundantly. Other details remain as stated in the classics.

Mix with water to form a paste similar in consistency to thick porridge. Select high-quality glutinous rice grains that are whole. Place half of the rice in the ash and half outside the ash. After one night, the rice buried in the ash changes color to become transparent like crystal. If there are black moles or tattoos on the hand surface, first gently stimulate the area with the tip of a needle. Apply a small amount of the crystal-like substance onto it. After about half a day, the juice will naturally exude. Remove the medication and do not use it again. Keep the area dry from water; healing occurs within two to three days. Additionally, take one he of newly made hard Duanshi (Burnt Stone), stir-fry it with vinegar, and mix into a mud-like paste. Apply this to the unaffected side of the lips in patients suffering from hemiplegia with facial deviation (wind-stroke affecting the mouth corner). The deviation will immediately correct itself.