chemically known as potassium alum or aluminum potassium sulfate, exhibits astringent properties when applied to the skin. Astringents work by causing proteins in the skin cells to coagulate ...

but the term 'alum' only applies to aluminium potassium sulphate (reviewed in Ref. 46) (see the table). Alum was used by Alexander Glenny and captures antigen by precipitation when the solution is ...

the tests were done with pure aluminum sulfate (the right name for alum). If you buy alum at the store, it is likely to have potassium or other additives and that might change the results or even ...