_a._ The oil is laevorotatory, the stearoptene melts at 77° F., and, on adding sulphuric acid, a clear solution remains behind: _Rose oil_. _b._ The oil possesses no rotatory power, the stearoptene melts at 50° F., and, on adding sulphuric acid, two layers are formed, only one of which is liquid: _Anise-seed oil_. _c._ The oil is dextrorotatory, the stearoptene melts at 41° F., and, on adding sulphuric acid, a nearly colorless fluid remains behind: _Fennel oil_. 3. The oil is perfectly fluid and clear at above 32° F. I. The oil explodes with iodine, emitting violet vapors. _a._ The oil thickens in the air and readily forms resin. It requires for its solution several volumes of alcohol: _Oil of conifers_. _b._ The oil, on exposure to the air, does not thicken and but slowly forms resin. α. It is dextrorotatory. The liquid oil dissolves santalin: _Oil of the aurantiaceæ_. The thick oil does not dissolve santalin: _Mace oil_. β. The oil is laevorotatory. The oil shows an acid reaction and dissolves in equal parts of alcohol: _Lavender oil_. The oil shows a neutral reaction and dissolves in 12 to 15 parts of alcohol: _Marjoram oil_. II. The oil gives no explosion with iodine, but shows an increase in temperature with or without emission of red vapors. _a._ The oil shows an acid reaction. α. The blue or green oil shows the acid reaction only indistinctly: _Milfoil oil_. β. The colorless or brown oil gives a turbid fluid with sulphuric acid. It is laevorotatory: _Spanish marjoram oil_. The oil is rendered but slightly turbid by sulphuric acid; it acquires a red-violet color by nitric acid, has no effect upon the plane of polarization, and has a peculiar odor: _Oil of valerian_. _b._ The oil is neutral. α. It dissolves with difficulty in alcohol. β. The oil is miscible in every proportion with alcohol. 1. It is dextrorotatory. The oil is colorless or yellowish, it thickens on exposure to the air, and dissolves and reduces fuchsine: _Caraway oil_. The oil is thick, yellow-brown or red-yellow, and has a peculiar odor: _Calamus oil_. 2. The oil is laevorotatory. It is fluid and has an aromatic odor: _Rosemary oil_. The oil is thick and very pungent: _Cubebs oil_. III. The oil dissolves iodine without vigorous reaction and without an increase in the temperature. _a._ The oil is blue and green. It has an agreeable, camphor-like odor: _Camomile oil_. The green oil thickens in the air and is dextrorotatory: _Wormwood oil_. The oil is generally green and produces no effect upon the plane of polarization: _Cajeput oil_. _b._ The oil is colorless or yellow-brown. α. It separates a solid stearoptene at about 32° F.: _Rue oil_. β. The oil remains liquid at several degrees below 32° F. 1. Dextrorotatory oils. The oil shows an acid reaction, and gives with sulphuric acid a somewhat turbid solution, which becomes clear by the addition of alcohol: _Dill oil_.