Salt is a chemical term for a substance produced by the reaction of an acid with a base. When sodium, an unstable metal that can suddenly burst into flame, reacts with a deadly poisonous gas known as chlorine, it becomes the staple food sodium chloride, NaCl, from the only family of rocks eaten by humans. There are many salts, and a number of them are edible and often found together. The one we most like to eat is sodium chloride, which has the taste we call salty. Other salts contribute unwelcome bitter or sour tastes, though they may also be of value to the human diet. Baby formula contains three slats: magnesium chloride, potassium chloride, and sodium chloride.Salt a World History, Penguin p. 5
