2768. Antacids are given to correct acidity in the system. They are soda, ammonia, chalk, and magnesia.

2769. Soda, carbonate of, and sesqui-carbonate of soda, are antacids and de-obstruents. They are used internally in acidity of the stomach and dyspepsia.

Dose of both preparations, from ten grains to half a drachm.