CARBONATES

Salts containing carbonic acid. They; are recognised by the effervescence which is excited when they are put into dilute muriatic acid. Carbonate of lime is one of the most important of these compounds, forming the varieties of marble, limestone, calcareous spar, chalk, . Carbonate of lime consists of Lime - • 1 atom = 28 • - 56 Carbonic acid • 1 - = 22 -.44 a 1 50 100 4 is Carbonate of potash and carbonate of soda are also important salts. (See Potash, Soda.) Carbonate of ammonia is used in medicine; it is a white pungent salt, commonly known under the name of smelling salt. Spirit of hartshorn is a solution of impure carbonate of ammonia, od tained bv distilling bone or horn. [s. 210]