Origin. - A volatile oil distilled from Cassia cinnamon, yielding not less than 75 per cent. by volume of cinnamic aldehyde.

Description and Properties. - A yellowish or brownish liquid, becoming darker and thicker with age and exposure to the air, having the characteristic odor of cinnamon and a sweetish, spicy, burning taste. Specific gravity, 1.045-1.055 at 25o C. Soluble in an equal volume of alcohol, the solution being slightly acid to litmus-paper; also soluble in an equal volume of glacial acetic acid. It should be kept in well-stoppered bottles, in a cool place, protected from light.

Constituents. - Oil of cinnamon contains variable quantities of hydrocarbons, but consists chiefly of cinnamic aldehyde, C6H5CHCHCOH, and when old or exposed to the air for a considerable time cinnamic acid and resin are formed. Cinnamic acid crystallizes in shining, colorless, odorless prisms, freely soluble in alcohol, ether, and boiling water. Chlorinated lime and hot dilute nitric acid oxidize it into oil of bitter almond and benzoic acid.

Dose. - 1-5 minims (0.06-0.3 Cc).

Official Preparations

Aqua Cinnamomi (0.2 per cent.) - Aquae Cinnamomi - Cinnamon Water. - Dose, 1/2-1 fluidounce (15.0-30.0 Cc.) [4 drams (16 Cc.), U. S. P.].

Spiritus Cinnamomi (10 per cent.) - Spiritus Cinnamomi - Spirit of Cinnamon. - Dose, 5-20 minims (0.3-1.2 Cc) [30 minims (2 Cc), U. S. P.].