Volatile Alkali and Hartshorn are other names for this substance. When pure, it is a gas ; but it is used either in the form of the Solid Carbonate of Am-monium, or in solution in Water (Aqua Ammonia), or in Alcohol. Smelling salts consist usually of the Carbonate. Druggists keep a stronger and a weaker watery solution of Ammonia. The medicinal form most used is the Aromatic Spirit of Ammonia (a solution in Alcohol, with Spices). This is a stimulant and antacid preparation. Its dose is from ten to twenty-five or thirty drops, in water. Aqua Ammonia (Water of Ammonia) is used to make Volatile Liniment, by mixing it with an equal quantity of Olive or Lard Oil. This liniment is * very warming thing to rub into the skin of the throat for a sore throat, as a counter-irritant.