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This is obtained from the initial collection and formed after a single decoction, without undergoing further refining processes; hence it is called *Puxiao* (Mirabilite). Its taste is extremely astringent and bitter, thus its action is firm, urgent, and not harmonious. It can cook raw hides of cattle and horses, and is used to test the authenticity of gold and silver. Ge Hong used this substance to purge and expel food stagnation that fails to digest. In the twelfth lunar month, take a new earthenware jar, fill it with hot water, add two *sheng* (approx. 0.6 L) of *Puxiao*, stir until dissolved, and hang it under the north eaves. Wait for the crystals to seep out onto the exterior of the jar, then collect them using feathers. Mix half a *qian* (approx. 1.5–2 g) with human breast milk and apply to any swelling or pain in the eyelids caused by wind-heat toxic pathogens, as well as sudden swelling and pain in the head, face, limbs, and extremities; the effect is immediate and miraculous.

The Classics state: *Mangxiao* (Thenardite) is derived from *Puxiao*. This involves leaching *Puxiao* with water to obtain the juice, clarifying it, and then boiling it down until the volume is halved. Pouring it into a wooden basin and leaving it overnight causes needle-like crystals with sharp edges to form. Therefore, its nature is milder, and since ancient times it has been widely used to treat *Shanghan* (Cold Damage disease).

This refers to the portion remaining after the second refining process, where the *Mangxiao* has already crystallized at the bottom like stone. Since the essence has been removed, only dregs remain. Consequently, its efficacy is also slower, possessing only a dry, fiery, and irritating quality. The *Tang Bencao* commentary notes: "It is likely named *Xiaoshi* (Niter) because it can dissolve various stones." When boiled in willow branch decoction for three weeks, it suppresses fire properties; if the liquid evaporates, more willow branch decoction should be added.

This is the extracted essence from *Puxiao*. Its taste is sweet, and it is known as *Yayanxiao* (Halotrichite). There are other methods of refining it. Due to the refining process, its taste differs. It treats accumulated heat in the five zang organs. However, these four substances originally come from one source. Through different refining processes, they are separated into refined and coarse parts, so their therapeutic applications are not far apart.

At the Fangzhou Alum Office today, wild fires are used to calcine the ore before extracting alum. The color is purely white, inferior to that from Jinzhou. None of these should be taken in large doses, as they damage the heart and lungs due to their ability to drain dampness/water. When dissolved in water and painted on paper, once dry, water cannot wet it again, proving its property of repelling water. Many phlegm-resolving medicines require it, utilizing this principle. Calcined into powder and applied topically, it treats ingrown nails (onychocryptosis). For bleeding from the gum margins resembling epistaxis, topical application also heals it.

It is now called *Huashi* (Talc), because it is soft and slippery enough for writing or drawing. Patients with *Lin* syndrome (dysuria) often use it. If sudden vomiting and inability to eat occur, take two *qianbi* (approx. 6 g) of raw fine powder, swallow with warm water, and immediately follow with half a cup of hot noodle soup to moderate the drug's action.