The essences or essential oils sold for general use are, or ought to be, obtained by distillation; but for many purposes they may be obtained equally as good, and in some cases superior, without. As these are often adulterated with olive or nut oils, or with spirits of wine, the fixed oils may be detected by pouring some of the suspected essence on a piece of clean writing-paper, and holding it before the fire; the quantity of fixed oil it contains will remain, leaving a greasy mark, whereas the pure essential oil will evaporate without leaving any appearance; if spirits of wine be added, pour a little water or oil of turpentine into the adulterated sample, and it will turn milky, as the two will not unite without producing this effect. It is often sophisticated with the oil of turpentine, which is the lightest of all essential oils; in this case, rub a drop over the hand and hold it by the fire, when it may be recognized by the smell; or, if burnt, it will give out a dense black smoke.

Rectified spirits of wine dissolve the volatile oil and resin of vegetables (their taste and smell most frequently reside in these), whilst water acts on the saline and mucilaginous parts. Proof spirit, which is a mixture of both these, extracts all their virtues, and through this we are enabled to obtain the essence or tincture of any vegetable, of superior quality to that generally sold, and at considerably less expense. The essential oil of lemons or oranges is obtained by rubbing off the yellow rind on the rough surface of a piece of loaf sugar, which is much superior for flavor to that produced by any other means. Scrape off the sugar after it has imbibed the oil, and dry it in a gentle heat, put it into small glazed pots, and tie them over with bladder; it will keep any length of time unimpaired. The same observation holds good as regards all fruit whose flavor or essential oil resides in its peel.

Allspice, Cloves, Cinnamon, or Nutmegs, Etc.—Two ounces of spice, one pint of proof spirit. Bruise the spice, put it into a bottle, stop it close, let it remain fourteen days, and filter for use.

The oil from nutmegs is often extracted from them by decoction, before they are brought to the market, and their orifices closed again with powdered sassafras; this may be ascertained by the lightness of the nut; if it is punctured with a pin, the oil will be pressed from it when good. These oils may be obtained by expression of distillation; they hold resin in solution, and consequently sink in water. The essences usually sold are made by adding half an ounce of pure oil to one pint of spirits of wine.

Bergamot, Essence of.—From the peel of the bergamot lemon.

Bitter Almonds, Essence of.—This is obtained by distilling the cake or residue of the almonds after the oil has been expressed from them. It is a deadly poison, containing prussic acid, like all other nuts or leaves which possess the bitter principle. Flies drop dead when passing over the still when it is in operation. The essence usually sold is one ounce of oil to seven ounces of rectified spirit.

Cedrat, Essence de.—From the yellow part of the fresh citron peel; it may also be obtained by pressing the yellow part of the peel between two glass plates, and by the distillation of the flowers of the citron-tree.

Ginger, Essence of.—The best Jamaica or China ginger two ounces, proof spirit one pint. Powder the ginger, mix with the spirit, stop close, and let it steep for twelve or fourteen days.

This is the same as is sold for "Oxley's concentrated essence of Jamaica ginger,"—a mere solution of ginger in rectified spirit—Paris's Pharmacologia.

Lemon, Essence of.—Eight ounces of lemon peel, ten ounces of rectified spirits of wine. Pare or grate off the yellow rind of the lemon very thin and weigh it, put it into a bottle and pour the spirit on it, stop it close, and let it steep for fourteen days, when it is fit for use. Proof gin or white rum will serve equally well, but not such as is generally sold at the gin-shops; this is excellent for ices, creams, lemonade, etc. In many establishments, where quantities of peel are thrown away, the cost of this would be comparatively trifling, compared with the price of the inferior oil generally sold.

Orange, Essence of.—Make as lemon, using only four ounces of the yellow rind.

Peppermint, Essence of.—"A spirituous solution of the essential oil, colored green by spinach leaves." This essential oil is obtained by distillation. Four pounds of dried leaves yield one ounce.

Vanilla, Essence of.—Vanilla two ounces, water ten ounces, rectified spirit three quarters of an ounce. Cut the vanilla in small pieces, and pound it fine in a marble mortar, with loaf sugar (about a pound), adding the white of an egg and the spirit. Put it into a glazed pot, tie a piece of writing paper over it, and make a hole in it with a pin; stand the pot in warm water, keeping it at that heat for twenty-four hours, then strain for use.

One drachm of this is equal to an ounce of vanilla, and is excellent for flavoring ices, creams, liqueurs, etc.