The pharmacodynamics of this group is due entirely to the non-metallic ion.

These substances have a soapy, detergent feeling in the mouth; are neutralized in the stomach, unless in large quantities; are absorbed rapidly from the intestines, as carbonates or in combination with proteins; increase the relative alkalinity of the blood; and are promptly excreted as alkaline salts from the kidney.

Concentrated solutions are strongly escharotic; especially is this true of the hydrates.

Therapeutics.

The Hydrates and Carbonates are used in weak solutions as antacids, affecting the alimentary tract, the blood, and the urine.

The most satisfactory drug of this class is sodium bicarbonate.

Dosage.

Sodii Bicarbonas, 0.5 to 2 Gm.

Calcium salts are absorbed very slowly, and in minute quantities. They have no obvious action except in cases showing deficiencies of lime. As an antacid, lime is inferior to sodium bicarbonate, because of its interference with digestive processes.

Calcium is an essential element in the blood for maintaining normal cardiac rhythmicity, and for the development of fibrin ferment; it is also essential to normal bone growth.

Calcium is excreted by the epithelium of the large intestine.

Therapeutics. - The only condition where lime is positively known to have been of benefit is in cases of tetany.