Origin. - A liquid composed of not less than 85 per cent. by weight of absolute orthophosphoric acid (H3PO4 = 97.8) and not more than 15 per cent. of water.

Description and Properties. - A colorless liquid, without odor, but having a strongly acid taste. Specific gravity not below 1.707 at 25o C. (77o F.). Miscible in all proportions with water or alcohol. Phosphoric acid should be kept in glass-stoppered bottles.

Dose. - The diluted acid only is given internally.

Official Preparation

Acidum Phosphoricum Dilutum - Acidi Phosphorici Diluti - Diluted Phosphoric Acid. - Diluted phosphoric acid contains 10 per cent. by weight of absolute orthophosphoric acid.

Dose. - 5-25 minims (0.3-1.5 Cc.) [15 minims (2 Cc.) U. S. P.].