This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Oil of cinnamon is obtained from the bark of the cinnamon tree, found in the forests of Ceylon, while oil of cassia is obtained from the bark of a similar tree found in Southern China and Cochin China. The bark of the Ceylon tree is the best and yields the most aromatic oil, which is prepared by distilling the chips and refuse bark with water. Oil of cinnamon is a pale-yellow or reddish liquid, becoming red-brown and thicker on exposure. It has a strong but agreeable cinnamon odor, and a sweet, hot and aromatic taste; specific gravity about 1.035, which increases by age; is readily soluble in alcohol.
Oil of Cassia is very much like the preceding, but its color is more brownish, its odor less delicate and its taste less sweet; specific gravity 1.055 to 1.065.
Oil of cinnamon is frequently adulterated with the cheaper oil of cassia. By ascertaining the specific gravity this may be detected. An adulteration with oil of cloves or oil of cinnamon-leaves is detected on heating, when acrid vapors will be given off. "A solution of four drops of oil of cinnamon in ten ccm. of alcohol should, on the addition of one drop of test solution of ferric chloride (ferric chloride dissolved in ten parts of water), give merely a brown but not a green or blue color (carbolic acid, oil of cloves, etc.)". - P. G.
Oil of Cinnamon-leaves is obtained by distilling the leaves with water. It is a brown liquid, specific gravity 1.053, has strong clove-like and faint nutmeg-like odor; after treatment with potassa the odor resembles that of cinnamon.
Oil Of Cinnamon-Root Is Yellow, Lighter Than Water, Odor Like That Of Cinnamon And Camphor. - N. D. and Muspratt's Chemie.
Take one pound of powdered cinnamon or cassia bark, and a mixture of equal parts of alcohol 95° and water. Moisten the powdered bark with six fluid ounces of this mixture, pack firmly in a percolator, then add the balance of the liquid to saturate the powder and leave a stratum above it. When the liquid begins to drop from the percolator close the lower orifice, cover the percolator tightly, and macerate for forty-eight hours. Then allow the percolation to proceed, gradually adding enough of the same liquid until the bark is exhausted and sixteen fluid ounces of extract are obtained.
Macerate one pound of bruised or powdered cinnamon or cassia bark in five pints of diluted alcohol, or a mixture of two and one-half pints of alcohol 95° and two and one-half pints of water. Filter.