Glauber’s salt is a chemical compound of sodium sulfate and water. The large, transparent crystals lose their water and become a white powder when exposed to air. Many mineral waters, seawater, and the mineral thenardite contain Glauber’s salt. It also forms part of a laxative called Hunyadi Janos. Glauber’s salt has been used as a laxative since the 1600’s. It was named in honor of the German chemist Johann Rudolf Glauber, who first prepared it for use in medicine.
