Alum and Calcined Alum—September 17, 1995

Alum and Calcined Alum—September 17, 1995

Alum is potassium aluminum sulfate, containing one molecule of crystallized water. After calcination to remove the water, it retains its properties but changes from pure white to grayish-white, with its weight reduced by half—this is calcined alum. Calcined alum is still potassium aluminum sulfate, with essentially the same medicinal properties as alum, except that it has a stronger astringent effect. It does not cause harsh acidic irritation to the gastrointestinal tract, making it highly effective in Xiao Fan San. My Gusheng II No. also uses this medicine.