CARBONATES

Salts containing carbonic acid. They are recognized 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 - I atom = 28 Carbonic acid 1 - = 22 50 100 Carbonate of potash and carbonate of soda are also important salts. (5fe Potash, Soda.) Carbonate qf ammonia is used in medicine; it is a whit a pungent salt, commonly known under the name of swelling salt. Spirit qf hartshorn is a solution of impure carbonate of ammonia, obtained by distilling bone or horn. [s. 208]