Mierzinski gives the following formulæ for bay rum:—
IV. Alcohol 8 ozs., oil of bay 40 drops, oil of mace 1 grain, oil of orange 20 drops, Jamaica rum 1 oz., water enough to make 16 ozs. Digest 2 or 3 weeks, and filter through magnesia.
V. Alcohol 8 ozs., oil of bay 2 drachms, oil of cloves 1 drop, mace 20 grains, water warmed to 80° F. to make 12 ozs. Dissolve the oils in the alcohol, digest the mace in the solution for a few days, filter and add the water. The whole is allowed to stand, with occasional agitation, for several days, and filtered through magnesia.
VI. Jamaica rum 36 ozs., 95 per cent. alcohol 36 ozs., oil of bay ½ oz., oil of pimento 1 drop, acetic ether 4 drops. Allow to stand at least 3 weeks before using.
Hair Dyes.—The requirements of a good hair-dye are that it can be readily applied, that it contains no injurious substances, and that the coloration be as natural and durable as possible. These demands are difficult to fulfil, and it cannot be said that there is one of the ordinary hair dyes which in every respect comes up to them. Black hair dyes give the most natural coloration, but the peculiar shade of blue-black hair cannot be imitated. The medium colors, light brown and blonde, are the least natural. Most dyes allow of rapid coloration, though, in order to make the deception more complete, a gradual coloration is by many persons preferred. Such gradual, though only very slightly darker coloration, is attained by the use of hair oils and certain animal fats containing a slight content of sulphur or iron, such as freshly expressed egg oil and neat's-foot oil. It was formerly believed that egg oil, if used in time, would even prevent the hair from turning gray. The gradual darkening of the hair may also be effected by agents, which are converted into colored combinations only by the atmospheric oxygen or the content of sulphur in the hair, such as extract from nut shells, tannin, pyrogallic acid and many metals, the latter chiefly in the form of pomades or hair oil. Dilute acids used for some time make the hair somewhat lighter. Mothers wishing to keep the hair of their children blonde, avoid oils, and frequently wash the heads of the children with vinegar or lemon juice. No coloration is, however, durable; it becomes in the course of time gradually weaker, and the new growth of hair always requires after-coloration.
For dyeing the hair metallic salts are chiefly employed. Owing to their poisonous action the use of lead salts for the purpose is prohibited in some countries, for instance, in Germany and Austria. Silver is used in the form of nitrate of silver (lunar caustic). In the presence of organic substances, as well as under the influence of light, this combination is reduced, metallic silver in small black grains being separated. Silver salts also give a black precipitate of silver sulphide with sulphuretted hydrogen. By simply moistening the hair with silver solution they become brown to brown-black, the coloration appearing more rapidly by previously treating the hair with pyrogallic acid, or, after the application of the silver solution, with sulphydrate of sodium or potassium. The colorations produced with nitrate of silver are very durable, but, if not dyed again for some time, the hair acquires a greenish or reddish color, this being especially the case if they were not sufficiently freed from fat before dyeing. For freeing the hair from fat, wash the hair with a mixture of 1 part spirit of sal ammonia in 10 parts of brandy, and dry carefully.
Copper salts with certain substances, such as potassium ferrocyanide solution, potassium sulphydrate, calcium sulphydrate, and pyrogallic acid give dark-brown colorations. Of the copper salts, the sulphate in ammoniacal solution is most frequently employed, though occasionally also the chloride. These salts give a beautiful brown color to the hair. Small quantities of copper salt are also frequently added to the actual black dyes; the hair by this means acquiring a brown-black, instead of a deep black color.
All the iron salts, with the exception of the chloride, may be used for dyeing the hair. Soluble iron salts by themselves make the hair somewhat darker, but this slow, natural process is not relied on, and a second substance forming dark colored combinations with the iron, such as sulphur, tannin, or pyrogallic acid, is, as a rule, employed. To this class belongs a Turkish hair dye, which, according to X. Landerer, is prepared as follows: Gall-nuts converted to a fine powder are mixed with oil and roasted in a pan until no more empyreumatic vapors and odor are evolved. The black powder thus obtained is made into a paste with water, and into it is stirred a finely pulverized mass prepared from ferrous oxide, copper, and antimony, the result being a deep black mass. This dye is called Rastikopetra (eyebrow-stone). It is one of the Oriental cosmetics used by both men and women.
Potassium permanganate solution is reduced by organic substances, peroxide of manganese being formed. A concentrated solution of this salt imparts to the hair and skin an intense brown color, which, however, is not very durable, and requires frequent renewing.
Pyrogallic acid may be used for darkening the hair, not only in combination with metallic substances, but also by itself, or with alkalies. Hair moistened with pyrogallic acid becomes under the influence of light and air dark gray to blackish. However, the color is not handsome, and appears only in the course of weeks. In connection with alkalies, pyrogallic acid produces a red-brown to black-brown coloration.