A volatile oil is also obtained by distillation from the leaves of the Juniperus virginiana. In odor it resembles savin oil, and is unfit for perfuming purposes.
Cherry-laurel oil (oleum laurocerasi) is the volatile oil, which contains prussic acid, obtained from the leaves of the cherry-laurel (Prunus laurocerasus, L.). Like bitter almonds, the leaves contain some amygdalin. Hence they are macerated with water and allowed to stand in a warm place for 24 hours. By subsequent distillation a volatile oil is obtained which closely resembles oil of bitter almonds, but differs in some respects. It is colorless or yellowish, rarely reddish, and of specific gravity 1.05 to 1.06. In its behavior towards air, solvents, and reagents, it does not essentially differ from oil of bitter almonds.[5]
To detect oil of mirbane in cherry-laurel oil, Enrico Pega adds some alcohol to the oil to be tested and then mixes it with some alcoholic potash lye and a few drops of ferric chloride solution. After standing for a few hours the mixture is shaken and distilled. A small portion of the oil distilling over is freed from water, poured upon a few small pieces of pure caustic potash in a test-tube, and heated over a lamp. If the sample is pure it remains colorless; in the presence of oil of mirbane it acquires a dark coloration in consequence of the formation of nitrobenzide and aniline, a few drops of calcium chloride solution brought into the mixture producing, for this reason, a violet coloration.
Cherry laurel oil is but seldom used for perfuming purposes.
Cinnamon oils.—There are four different kinds of this oil, viz., Ceylon cinnamon oil, cassia oil, cinnamon root oil, and oil of cinnamon leaves. Though the first two are very much alike, the Ceylon oil is considered the best.
Ceylon cinnamon oil (oleum cinnamoni ceylonici).—Formerly this oil was exclusively distilled from chips and waste of the genuine cinnamon bark of the Cinnamonum ceylonicum, Nees, and came into commerce from Ceylon. However, the fabrication of the oil from cinnamon waste or chips is now extensively carried on in Germany, and this oil, being prepared with the assistance of more perfect apparatus, has almost entirely supplanted that exported from Ceylon.
When fresh, the Ceylon oil is colorless, but when stored for some time it becomes first golden yellow and later on brownish. It is thickly-fluid and heavier than water, its specific gravity being 1.060 to 1.090. It has an agreeable, aromatic odor and a biting but pure, sweet taste. Its principal constituent is cinnamaldehyde (C9H8O), and it contains, besides, 4 to 8 per cent. of eugenol. The presence of the latter in cinnamon oil may be established by shaking with 15 per cent. soda-solution, whereby the eugenol is dissolved, and decomposing the aqueous solution with hydrochloric acid. The eugenol separated thereby gives in alcoholic solution, when compounded with a trace of ferric chloride, a beautiful blue color.
Cassia oil (oleum cassiæ).—In China and Cochin China this oil is obtained by distillation from the bark, unripe fruits, buds, and other waste of the Cinnamonum cassia or Cinnamonum aromaticum, Nees, a tree indigenous to those countries. It has a pale yellow color, which in time becomes brown. It is thickly-fluid, of specific gravity 1.05 to 1.07, and possesses a sweet taste with an acrid after-taste. Like cinnamon oil, it consists chiefly of cinnamaldehyde, but contains no eugenol, and hence can be readily distinguished from Ceylon oil by the above-mentioned reaction. One part of pure cassia oil dissolves in two parts of 80 per cent. alcohol.
Cinnamon root oil and oil of cinnamon leaves.—Neither of these oils contains cinnamaldehyde, but abundant quantities of eugenol, the root oil as much as 50 to 70 per cent. The root oil is quite limpid and has an agreeable odor of cinnamon and cloves. The leaf oil is thickly-fluid, of the consistency of castor oil.
The Ceylon oil is frequently adulterated with cassia oil. Such adulteration is very difficult to detect, and can only be recognized by experts by the odor and taste.