Preston Salt (Sel Volatil).
In this perfume ammonia is continually generated; the salt is prepared by mixing chloride of ammonium or sal-ammoniac in fine powder with freshly slaked lime. Fine or cheap perfume is added, according to the grade desired. The mixture of sal-ammoniac and slaked lime continually develops small amounts of ammonia—it takes a long time until the decomposition is complete, and for this reason a bottle filled with Preston salt retains the odor of ammonia for several years.
Eau de Luce.
This is the only ammoniacal perfume used in a liquid form. It is made according to the following formula:
| Tincture of ambergris | 10½ oz. |
| Tincture of benzoin | ½ lb. |
| Oil of lavender | 150 grains. |
| Water of ammonia | 1½ lb. |
The tinctures are mixed with the ammonia by agitation and immediately filled into bottles; the liquid should have a milky appearance. At times 150 grains of white soap is added which aids in imparting to the liquid the desired milky appearance. In fine eau de Luce the odor of ambergris should predominate; this can be easily effected by increasing the amount of tincture of ambergris.
B. Acid Perfumes.
As there is a group of perfumes which is distinguished by their characteristic odor of ammonia and which we have therefore called ammoniacal, so there is an important series of articles containing acetic acid which are used cosmetically as so-called toilet vinegars, and in some washes.
Ordinary vinegar, i.e., water containing four to six per cent of acetic acid, has, as is well known, a not unpleasant refreshing odor and a pure acid taste. Pure acetic acid, now made in large quantities and of excellent quality, is known commercially as glacial acetic acid. In commerce, it is customary to designate any acetic acid containing 85 or more per cent of the absolute acid, as glacial acetic acid. In chemical or pharmacopœial nomenclature, however, the glacial acid is meant to be as near 100% as possible. In perfumery, an 85% acid is sufficiently strong. It forms a colorless liquid with a narcotic odor and an intensely acid taste; it congeals into glassy crystals at a temperature of 8.5° C. (47° F.). The latter property is of importance as showing the purity of the acid. Concentrated acetic acid, like alcohol, dissolves aromatic substances, with which it forms perfumes which differ from those made with alcohol mainly by their peculiar refreshing after-odor which is due to the acetic acid.
Acetic acid can be saturated with various odors and thus furnish fine perfumes; but for so-called toilet vinegars which are used as washes the acetic acid must be properly diluted, since the concentrated acid has pronounced caustic properties, reddens the skin, and may even produce destructive effects on sensitive parts such as the lips.