PRESTON SALTS, which is the cheapest of all the ammoniacal compounds, is composed of some easily decomposable salt of ammonia and lime, such as equal parts of muriate of ammonia, or of sesqui-carbonate of ammonia, and of fresh-slaked lime. When the bottles are filled with this compound, rammed in very hard, a drop or two of some cheap otto is poured on the top prior to corking. For this purpose otto of French lavender, or otto of bergamot, answers very well. We need scarcely mention that the corks are dipped into melted sealing-wax, or brushed over with liquid wax, that is, red or black wax dissolved in alcohol, to which a small portion of ether is added. The only other compound of ammonia that is sold in the perfumery trade is Eau de Luce, though properly it belongs to the druggist. When correctly made--which is very rarely the case--it retains the remarkable odor of oil of amber, which renders it characteristic. EAU DE LUCE. Tincture of benzoin: or, } " balsam of Peru, } 1 oz. Otto of lavender, 10 drops. Oil of amber, 5 " Liquor ammonia, 2 oz. If requisite, strain through cotton wool, but it must not be filtered, as it should have the appearance of a milk-white emulsion. ACETIC ACID AND ITS USE IN PERFUMERY.--The pungency of the odor of vinegar naturally brought it into the earliest use in the art of perfumery. The acetic acid, evolved by distilling acetate of copper (verdigris), is the true "aromatic" vinegar of the old alchemists. The modern aromatic vinegar is the concentrated acetic acid aromatized with various ottos, camphor, &c., thus-- AROMATIC VINEGAR. Concentrated acetic acid, 8 oz. Otto of English lavender, 2 drachms. " " rosemary, 1 drachm. " cloves, 1 " " camphor, 1 oz. First dissolve the bruised camphor in the acetic acid, then add the perfumes; after remaining together for a few days, with occasional agitation, it is to be strained, and is then ready for use. Several forms for the preparation of this substance have been published, almost all of which, however, appear to complicate and mystify a process that is all simplicity. The most popular article of this kind is-- HENRY'S VINEGAR. Dried leaves of rosemary, rue, wormwood, sage, mint, and lavender flowers, each, 1/2 oz. Bruised nutmeg, cloves, angelica root, and camphor, each, 1/4 oz. Alcohol (rectified), 4 oz. Concentrated acetic acid, 16 oz. Macerate the materials for a day in the spirit; then add the acid, and digest for a week longer, at a temperature of about 14 deg. C. or 15 deg. C. Finally, press out the new aromatized acid, and filter it.