The oil from the root contains cinnamyl aldehyde, hydrocarbon and ordinary camphor, and is lighter than water, both the oil of the bark and of the leaves being heavier. Oil from cinnamon bark and shoots is seldom exported. The oil is obtained in Ceylon by macerating the powdered bark or roots with a saturated solution of common salt for two days, after which the whole is distilled. Cinnamyl aldehyde, which is a very pleasant smelling colorless liquid, may be separated from hydrocarbon, which is also found in the oil, by bringing the oil in contact with concentrated nitric acid. The crystals, which separate in long rhombic prisms or small plates, are decomposed by water into nitric acid. Free cinnamyl aldehyde may be prepared by allowing a mixture of ten parts benzolaldehyde, fifteen parts acetaldehyde, 900 parts of water, and ten parts of a 10 per cent. solution of caustic soda to stand eight or ten days, at a temperature of 30 degrees, the whole being frequently agitated. Finally the aldehyde is extracted by means of ether. The pure Chinese cassia lignea bark, essential oil 1.5 per cent., has a specific gravity of about 1.035 to 1.060; aldehyde, 89.9 per cent., and at 15 C. should have a specific gravity of 1.050 to 1.070. On distilling, about 90 per cent. of pure cassia oil should pass over, and the balance, 10 per cent. residue, must not become solid in cooling, must not be brittle but must be in a semifluid state. If the oil contains less than 70 per cent. of cinnamyl aldehydes it may be considered adulterated, and at 75 per cent. should be handled with suspicion. 14 to 9 years old, 79 per cent. Cinnamyl aldehyde 15 years old, 70 per cent. Cinnamyl aldehyde 16 years old, 73 per cent. Cinnamyl aldehyde Cinnamic acid occurs in the flowers of cinnamon and forms in small quantities by oxidation of the cinnamyl aldehyde when it comes in contact with the open air. It will dissolve in 3,500 parts of water at 17 degrees and is more readily soluble in boiling water and crystallizes from it in lustrous plates. From the cassia buds, refuse bark, young shoots and roots a fragrant volatile substance is obtained which floats on water, and when removed and allowed to cool, it becomes a suet, giving a delicious odor in burning, called a cinnamon suet, or wax, which is used largely by the Catholics and Buddhists in worship and at high native weddings. It was formerly used in Ceylon for making candles.