The Chinese medicine is the refined crystalline sodium sulphate, usually made from natural sources, natrii sulfas as its chief component. The medicinal material is mainly produced in the provinces of Hebei, Henan, Shandong, and Jiangsu, etc.. The mineral substance containing Natrii sulfas is decocted in hot water with pieces of turnips, and the upper part of the decoction is taken out and treated by cooling, the refined sodium sulphate can be crystallized out, which is called Mangxiao (Natrii Sulfas). The dehydrated white powder of Mirabilite is called Xuanmingfen (Natrii Sul fus Exsiccatus ).

Medicinal Properties: Salty and Bitter in flavor, cold in nature and attributive to the stomach and large intestine meridians.

Actions: Soften dried feces to induce downward discharging, clear away heat.

Application
1. For constipation caused by accumulation of sthenic-heat in the stomach and intestine, it is especially suitable for constipation due to dry feces with difficulty in defecation, usually combined with Dahuang (Radix et Rhizoma Rhei), such as Da Chengqi Tang (Decoction).
2. For sore throat and aphthae, it is usually combined with Pengsha (Borax), Zhusha (Cinnabaris) and Bingpian (Borneolum Syntheticum) that are pounded into powder for external use, that is, Bingpeng San (Powder). Also put in watermelon, and prepared into Xigua Shuang (Pulvis Pericarpii Citrulli Preparatus) for external use.  The solution form of Xuanmingfen (Natrii Sulfus Exsiccatus) can be used for eye drops to treat bloodshot eyes.
3. It is generally indicated for the swelling and sores of carbuncles. It can be wrapped with gauze or dissolved in water for external application to treat the early stage of mastitis. It is also combined with Dahuang (Radix et Rhizoma Rhei) and garlic (Bulbus Allii), which are ground into pieces for external use to treat the early stage of intestinal abscess.

Usage and Dosage:
10 -18 g is used in decoction for oral use, dissolved in decoction or in boiling water for oral use. Just right amount is for external use. Xuanmingfen (Natrii Sulfas Exsiccatus) is usually used in oral and eye.

Notes:
Contraindicated during pregnancy and lactation.