This preparation in all the leading pharmacopeias of the world, is now uniformly directed to contain 2 per cent, of hydrogen cyanid, HCN.

Properties : It occurs as a colorless liquid of a characteristic odor resembling that of bitter almonds. On account of its poisonous character it should be tasted only with great caution. Hydrocyanic acid is freely miscible with water and with alcohol.

Incompatibilities: It gradually decomposes on exposure to light and is incompatible with salts of iron, silver and mercury.

Action and Uses: Hydrocyanic acid is said to be sedative in small doses and has been widely used as an addition to cough mixtures, and as an antiemetic. On account of its poisonous properties and the readiness with which it decomposes, it is no longer used to the same extent as formerly.

Dosage: 0.1 C.c. Or 1.5 Minims (Not Drops).