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Substances that counteract or neutralize acidity. They are used mainly for the treatment of gastrointestinal irritation or ulcers.

Remedies which obviate acidity in the stomach. They are chemical agents, and act by neutralizing the acid. Those chiefly used are ammonia, calcis carbonas, calx, magnesia, magnesia carbonas, potassa, potassae bicarbonas, p. carbonas, sodae bicarbonas, and s. carbonas. They are, of course, only palliatives, removing that which exists, not preventing the formation of more.