SECTION III. ARTIFICIAL ESSENTIAL OILS. THE study of the numerous compounds of organic chemistry, especially the ethers derived from alcohol and potato oil, has produced, of late, an industrial result as curious as interesting, in view of its various applications. Indeed, while chemical analysis found, in the composition of some perfumes, real organic ethers, synthesis, on the other hand, realizing the direct production of these same ethers, taught the chemist to prepare them in such a state of purity that it was easy to confound them, by their physical properties, with the natural perfumes. From this double discovery has risen, little by little, an industry which, in a short time, has acquired in France, England, and Germany, considerable importance. Its object is to manufacture liquids, often complex in their composition, which, dissolved in a certain quantity of pure alcohol, are known by the name of artificial oils. Compounds may also be prepared which communicate to ordinary alcohol the odor, but not the qualities, of brandy, whiskey, etc.; and others, which are much used in confectionery, possess the taste of pineapple, strawbérry, pear, apple, &c. We must also consider, but only in a commercial point of view, nitrobenzine as an artificial oil. This product, very different in its chemical composition from those we have spoken of, is in great demand by perfumers, who use it instead of oil of bitter almonds to perfume soaps. The preparation of these products is kept secret by manufacturers; however, we can give some information on the subject which will guide the reader who would study the subject. CUCUMBERS-LEMON-NITRO-BENZINE-TABLE. Oil of Brandy and Wine. THE substance used under this name is a complex mixture of several ethers of the ethylic series, but the odoriferous qualities appear to be due apparently to pelargonic ether. Two methods may be used to prepare it; the first gives pelargonic ether nearly pure-the other gives a mixture of very variable composition and of inferior quality. In the first case, the oil furnished by the distillation of the ruta graveolens, and known in the trade by the name of oil of rue, is the starting point of the operation. Treated by nitrid acid, this oil is transformed into pelargonic acid, which is easily etherefied. The preparation is then divided into two distinct phases. Introduce into a large retort equal parts of oil of rue and nitric acid diluted with its volume of water. Then heat gently. The reaction is not long to begin; red vapors are abundantly disengaged. As soon as this effect is manifested, the heat is stopped. When the disengagement of red vapors and the attack of the oil have diminished in intensity, cause the contents of the retort to boil, and continue until no more red vapors are disengaged. Collect the oil which floats on the surface of the acid. It is impure pelargonic acid, formed by the oxidation of the oil. Before transforming this acid into ether, it is necessary to purify it; for this purpose treat the crude pelargonic acid by a solution of potash, which dissolves it, leaving a very bitter oil in an insoluble state. The pelargonate of potash, afterwards decomposed by adding little by little sulphuric acid until saturated, furnishes pelargonic acid, which, being washed with water, is sufficiently pure. To transform pelargonic acid into ether, dissolve it in concentrated alcohol, and pass through the solution a current of dry hydrochloric acid gas. The liquor becomes muddy, and some oily drops are seen to ascend to the surface, which form a bed of pelargonic ether, colorless or slightly yellowish, with an odor similar to that of butyric, capric, etc. ethers. In the second case, it is by the oxidation of fatty acids that we obtain ethers having the odor of wine and brandy. When neutral or fatty acid bodies are submitted to the action of concentrated |