In the latter part of the last century, it used to be brought to Europe by the Dutch. During the five years from 1775 to 1779 inclusive, the average quantity annually disposed of at the sales of the Dutch East India Company was 176 ounces. The wholesale price in London between 1776 and 1782 was 21s. per ounce; but from 1785 to 1789, the oil fetched 63s. to 68s., the increase in value being doubtless occasioned by the war with Holland commenced in 1782. The oil is now largely produced in Ceylon, from which island the quantity exported in 1871 was 14,796 ounces; and in 1872, 39,100 ounces.[1947] The oil is shipped chiefly to England.
Oil of cinnamon is a golden yellow liquid, having a sp. gr. of 1·035, a powerful cinnamon odour, and a sweet and aromatic but burning taste. It deviates a ray of polarized light a very little to the left. The oil consists chiefly of Cinnamic Aldehyde, C₆H₅(CH)₂COH, together with a variable proportion of hydrocarbons. At a low temperature it becomes turbid by the deposit of a camphor, which we have not examined. The oil easily absorbs oxygen, becoming thereby contaminated with resin and cinnamic acid, C₆H₅(CH)₂COOH.
Cinnamon contains sugar, mannite, starch, mucilage, and tannic acid. The Cinnamomin of Martin (1868) has been shown by Wittstein to be very probably mere mannite. The effect of iodine on a decoction of cinnamon will be noticed under the head of Cassia Lignea. Cinnamon afforded to Schätzler (1862) 5 per cent. of ash consisting chiefly of the carbonates of calcium and potassium.
Uses—Cinnamon is used in medicine as a cordial and stimulant, but is much more largely consumed as a spice.
Adulteration—Cassia lignea being much cheaper than cinnamon, is very commonly substituted for it. So long as the bark is entire, there is no difficulty in its recognition, but if it should have been reduced to powder, the case is widely different. We have found the following tests of some service, when the spice to be examined is in powder:—Make a decoction of powdered cinnamon of known genuineness; and one of similar strength of the suspected powder. When cool and strained, test a fluid ounce of each with one or two drops of tincture of iodine. A decoction of cinnamon is but little affected, but in that of cassia a deep blue-black tint is immediately produced (see further on, Cort. Cassiæ). The cheap kinds of cassia, known as Cassia vera, may be distinguished from the more valuable Chinese Cassia, as well as from cinnamon, by their richness in mucilage. This can be extracted by cold water as a thick glairy liquid, giving dense ropy precipitates with corrosive sublimate or neutral acetate of lead, but not with alcohol.
Other products of the Cinnamon Tree.
Essential Oil of Cinnamon Leaf (Oleum Cinnamomi foliorum)—This is a brown, viscid, essential oil, of clove-like odour, which is sometimes exported from Ceylon. It has been examined by Stenhouse (1854), who found it to have a sp. gr. of 1·053, and to consist of a mixture of Eugenol ([p. 284]) with a neutral hydrocarbon having the formula C₁₀H₁₆. It also contains a small quantity of benzoic acid.
Essential Oil of Cinnamon Root (Oleum Cinnamomi radicis)—A yellow liquid, lighter than water, having a mixed odour of camphor and cinnamon, and a strong camphoraceous taste. Both this oil and that of the leaf were described by Kämpfer (1712) and by Seba in 1731,[1948] and perhaps by Garcia de Orta so early as 1563. Solid camphor may also be obtained from the root. A water distilled from the flowers, and a fatty oil expressed from the fruits are likewise noticed by old writers, but are unknown to us.
CORTEX CASSIÆ LIGNEÆ.
Cassia Lignea, Cassia Bark.