was an important industrial product. In addition to its use in leather processing, it served as a mordant in wool dyeing. From the mid-19th century onward, it was gradually replaced by other compounds, particularly aluminum sulfate, and is now of only minor significance.

The first sulphuric acid salts were identified as such in the 17th century. Sodium sulphate, specifically its decahydrate known as Glauber's salt, was described