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.
To many it may appear a somewhat startling statement that oil of lemon, bergamot, orange and many others of fragrant perfume, are strictly identical in chemical composition with the so-called spirits of turpentine used by painters. When these substances are analyzed, or, as it were, torn asunder by the astute contrivances of chemists into their ultimate constituents, these are found to be the same in both cases. It is a still more singular fact that even the relative proportions of these constituents are identical. The general formula of all these oils is thus stated: C10 H16, indicating thereby that ten atoms of carbon, represented by the letter 0, are in combination wh\h sixteen atoms of hydrogen (H). The carbon is identical with ordinary charcoal as well as also with the diamond, while the hydrogen is an elementary gas, which is one of the constituents of water. This may partially explain the fact that, when oil of lemon, orange or limes becomes old and rancid, the odor so closely resembles that of turpentine.
Oil of lemon has a pale-yellow color, is limpid, neutral, of a very agreeable fragrance, and mild, aromatic, bitterish taste. As received in commerce it is usually turbid, but becomes clear on standing; by age it acquires a thicker consistence, and a pungent terebinthinate odor and taste, which change is prevented or. retarded by the addition of alcohol, as previously directed, and decanta-tion of the clear oil from the sediment.
The" specific gravity of lemon oil should be 0.852; it commences to boil at 160° C. (B20° F.), and rotates polarized light to-the .right. It is already volatilized in association with aqueous vapor at 212° H
Oil of lemon yields with seven parts of alcohol, specific gravity 0.339, turbid solution, but is soluble in all proportions in carbon disulphide or absolute alcohol. - N. D.
Under the heading of "Oxygen in "Water," on page .48, we referred to experiments of Mr. Warren in regard to lemon oil becoming ozonised. It is stated there that the oxydation of lemon oil by the oxygen of the water of lemonades is probably in a great measure the cause of the deterioration of the latter, and this is a point which requires careful examination and attention.