Oleum Cinnamomi (U. S. P.)—Oil of Cinnamon.

Preparations: Cinnamon Water - Spirit of Cinnamon
Related entry: Cinnamomum.—Cinnamon

"A volatile oil distilled from cassia cinnamon. It should be kept in well-stoppered bottles, in a cool place, protected from light"—(U. S. P.).
SYNONYMS: Oil of cassia, Oleum cinnamomi cassiae, Oleum cassiae, Chinese oil of cinnamon.

Source, Preparation, and Description.—There are several oils of cinnamon the chief commercial varieties of which are the Oil of Chinese Cinnamon, and the Oil of Ceylon Cinnamon; the former alone is recognized by the present edition of the U. S. P.

Ɣ I. OLEUM CINNAMOMI ZEYLANICI, Oil of Ceylon cinnamon.—Oil of cinnamon is obtained in Ceylon, by macerating refuse bark and chips, reduced to a coarse powder, in sea-water for two days, adding chloride of sodium, and then distilling off the water. Part of the oil floats, and the other part sinks in the water which comes over; the whole amounting on an average to 8 ounces from 80 pounds, avoirdupois, of recently prepared cinnamon (0.5 to 1 per cent, Schimmel & Co.). The color of oil of cinnamon is pale-yellow, or wine-yellow, which slowly passes to cherry-red. Its taste is at first sweetish, afterward burning and aromatic. It is readily soluble in alcohol, also clearly soluble in 3 parts of 70 per cent alcohol. Its specific gravity varies from 1.024 to 1.040 (about 1.040, U. S. P., 1880). This oil has the finest aroma of all cinnamon oils; the chemical nature of the aromatic principle, however, is not known. The oil contains 65 to 75 per cent of cinnamic aldehyde, and about 4 to 8 per cent of eugenol, both of which form the heavy distillate; the lighter distillate contains the hydrocarbon phellandrene. This oil is often adulterated with the oil from the leaves, which are frequently distilled along with the bark; the oil of the leaves (1.8 per cent) is characterized by a much higher percentage of its eugenol contents (70 to 90 per cent), and consequently by a higher specific gravity (1.044 to 1.065).

II. OLEUM CINNAMOMI CASSIAE.—Oil of cassia, or Chinese oil of cinnamon, resembles the Ceylon oil in color, odor, and taste, but it is much inferior. Its chemical reactions are similar to those of the oil of cinnamon, as well as are its medicinal virtues. The Chinese oil is optically inactive, while the Ceylon oil is slightly laevo- or dextro-gyrate. According to Schimmel & Co. (Report, Oct., 1892), this oil is obtained mainly from cassia leaves mixed with stem, twigs, and refuse portions of the trees. Schimmel & Co. (Semi-Annual Report, Oct., 1892 and Oct., 1893) obtained by separate distillations of various parts of cassia, the following percentages of cinnamic aldehyde :

PART. Per cent Yield of oil.
Per cent.
Specific gravity.
Cassia bark. 88.9 1.5 1.035 at 20° C.
Cassia buds. 80.4 1.55 1.026 at 20° C.
Cassia bud-sticks. 92 1.64 1.046 at 15° C.
Cassia branch tops. 90 0.2 1.045 at 15° C.
Cassia leaves. 93 0.54 1.056 at 15° C.
Cassia leaves, leaf-stalks, and young twigs, mixed. 93 0.77 1.055

The U. S. P. describes the official oil as follows: "A yellowish or brownish liquid, becoming darker and thicker by age and exposure to the air, having the characteristic odor of cinnamon, and a sweetish, spicy, and burning taste. Specific gravity, 1.055 to 1.065 at 15° C. (59° F.). 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. When shaken with a saturated solution of sodium bisulphite, it solidifies to a crystalline mass. If 4 drops of the oil, contained in a test-tube, be cooled to 0° C. (32° F.), and then shaken with 4 drops of fuming nitric acid, crystalline needles or plates will be formed"—(U. S. P.). In the latter reaction, the cinnamic aldehyde of the oil and the nitric acid unite to form a decomposition product, decomposable by water.

Chemical Composition and Tests.—The chief constituent of cassia (Chinese) oil is cinnamic aldehyde (C6H5CH:CHCHO), discovered, in 1834, by Dumas and Péligot. It is a light-yellow liquid, of specific gravity 1.064 at 15° C. (59° F.), forming a crystallizable compound, as stated above, with nitric acid, also with sodium bisulphite. Upon the formation of this compound is based a method for the valuation of cinnamic aldehyde in oil of cassia, devised by Messrs. Schimmel & Co. (For a description of this process, see Gildemeister and Hoffmann, Die Aetherischen Oele, 1899.) Other constituents of oil of cassia are cinnamyl-acetate (C9H9.C2H3O2) (Schimmel & Co., 1889), and 1 per cent of free cinnamic acid, formed by oxidation of cinnamic aldehyde. The presence of this acid causes corrosion of the leaden containers in which the oil is shipped. Oil of cassia was at one time much adulterated with colophony and petroleum. The U. S. P. directs the following tests: "If a portion of the oil be shaken with water, and the liquid passed through a wet filter, the clear filtrate should give, with a few drops of basic lead acetate T.S., a white turbidity, without a yellow color (absence of oil of cloves). If 4 drops of the oil be dissolved in 10 Cc. of alcohol, the subsequent addition of a drop of ferric chloride T.S. should produce a brown, but not a green or blue, color (absence of oil of cloves or of carbolic acid). If 1 Cc. of the oil be mixed with 3 Cc. of a mixture of 3 volumes of alcohol and 1 volume of water, a clear solution should result; and if to this solution there be gradually added. 2 Cc. of a saturated solution of lead acetate in a mixture of 3 volumes of alcohol and 1 volume of water, no precipitate should be produced (absence of petroleum, or of colophony)"—(U. S. P.). The latter test is that of Hirschsohn (1890).

Action, Medical Uses, and Dosage.—Oil of cinnamon is stimulant, aromatic, antispasmodic, and carminative. It is frequently used to modify the taste of medicines, and is given as a stimulant in flatulent colic, cramps of the stomach, paralysis of the tongue, etc. It exerts an influence upon the uterus, and is one of the most valuable of agents, in the form of alcoholic tincture, in uterine hemorrhage. The tincture of the bark is frequently administered for this purpose, but we know from experience, that although destitute of astringency, yet the tincture or essence of the oil has the same, if not a better action, in such cases; again it is an unsafe remedy to exhibit during pregnancy, as it is very apt to produce miscarriage. The essence, or even cordial of cinnamon, stimulates the generative organs, and produces an aphrodisiac influence. Tincture of oil of cinnamon combined with ergot, ipecac, erigeron, or lycopus, as indicated, is an excellent remedy for hemoptysis. The dose of oil of cinnamon is 1 or 2 drops, given in emulsion; of the essence from ½ to 1 fluid drachm, given in a wine-glass of sweetened water. Ten drops of oil of cinnamon added to a fluid drachm of olive oil, gently heated and rubbed upon the spine, will frequently quiet a restless, fretful child suffering with flatulence or colic, and cause it to sleep; if the rubefacient power requires to be increased, 10 drops of aqua ammoniae may be added.

Related Oils.—OLEUM CINNAMOMI RADICIS, Oil of cinnamon root. Distilled from the root-bark of Cinnamomum Zeylanicum, Breyn. This oil is nearly colorless, has a cinnamon-like and camphoraceous odor, and a camphor-like taste. It is not so heavy as water, and at ordinary temperature separates common camphor. It also contains cinnamic aldehyde.

OLEUM CINNAMOMI FOLIORUM, Oil of cinnamon leaves.—Distilled from the leaves of Cinnamomum Zeylanicum. This is a bright, limpid, pale-yellow oil, with a combined cinnamon-clove odor. Its constituents are eugenol, safrol, and cinnamic aldehyde, sometimes replaced by benzaldehyde (also see Oleum Cinnamomi Zeylanici).

OIL OF CINNAMON from the bark of a north Indian tree, the Cinnamomum Wightii, of Meissner, is highly aromatic, has a specific gravity of 1.01, and boils between 130° and170° C. (266° and 338° F.). The yield is 0.3 per cent (Schimmel & Co.).

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.