As used today, “salt” denotes a chemical compound made up of positively charged cations and negative anions. However, the theory of ionic bonding that defines the salt as a type was described only in 1915 by the German physicist Walther Kossel. Up to the 19th century, salts were identified primarily on the basis of their taste, solubility in water, and resistance to fire; on the basis of their resemblance to ordinary edible salt, they were grouped together as “salt-li…