Liquid dyes are easily applied, more certain in their effect, and, undoubtedly, less unpleasant to those who have occasion to use them. Liquid dyes may be divided into two classes, namely, those which gradually darken the hair, and those which produce an instantaneous change. Before proceeding farther, it is advisable to note the chemical constituents of hair, because a successful result depends, to a certain extent, at least, upon this being taken into consideration and acted upon accordingly. It is known to scientific men that the chemical constituents of hair, according to the analysis of Vauquelin, are—animal matter in considerable proportion; a greenish black oil; a white concrete oil, in small quantity; phosphate of lime; carbonate of lime, a trace; oxide of manganese; iron, sulphur, and silex. Red hair contains a reddish oil, a large proportion of sulphur, and a small quantity of iron. White hair exhibits a white oil, with phosphate of magnesia. The white hair of old persons contains a maximum proportion of phosphate of lime. In preparing a dye for the hair, where the required element is absent it has to be supplied by art. For illustration, in red hair sulphur largely predominates, and as a consequence the hair readily darkens; in white hair—the white hair of aged persons—it is not to be found; hence the necessity of supplying a mordant to produce the desired effect.
To gradually darken the hair, then (assuming that sulphur is still developed in the course of its formation), a wash composed of a weak solution of the salts of iron, such as the sulphate, acetate, lactate, or protoiodide will be sufficient. A very small quantity of glycerine can be added at pleasure, but to the latter it is necessary. Here are two or three recipes:—(6) Sulphate of iron (green; crushed), 1 drachm; rectified spirit, 1 fluid oz.; oil of rosemary, 10 or 12 drops; pure soft water, ½ pint; agitate them together until solution and mixture are complete. Many persons substitute the strongest old ale for the “water” in the above. Another formula is, (7) take of rust of iron, 1 drachm; old ale (strongest), 1 pint; oil of rosemary, 12 or fifteen drops; put them into a bottle, very loosely corked, agitate daily for ten or twelve days, and then, after repose, decant the clear portion for use. The following is said to be a favourite among fashionable Parisians. (8) “Parisian.” Take of sulphate of iron (green), 15 to 20 grains; distilled verdigris, 5 or 6 grains; white wine (good), ¼ pint; eau de Cologne (to scent), q.s.; mix. It should be mentioned that all these washes will “iron-mould” linen if they are brought in contact. Should the foregoing not answer satisfactorily, the cause will probably arise through the absence of the normal sulphur of the hair, and in that case, water containing a little sulphuret of potassium, or hydrosulphuret of ammonia should be used once or twice a week.
Much has been said concerning lead dyes, and the injurious effects produced upon individuals who have used them for any length of time. Dr. Benjamin Godfrey, a gentleman with whom I had the honour of being acquainted, devoted considerable attention to this question, and in his treatise on “Diseases of Hair,” published in 1872, says: “The common hair cosmetics of the present day contain lead. The following is a rough analysis of the more noted:—
“Mrs. S. A. Allen’s World’s Hair Restorer, acetate of lead, sulphur and glycerine.
“Rossetter’s Hair Restorer, ditto.
“Simeon’s American Hair Restorer, ditto.
“Hall’s Vegetable Sicilian Hair Renewer, ditto.
“Aqua Amarella, ditto.
“Helmsley’s Celebrated Hair Restorer, ditto.
“Melmoth’s Oxford Hair Restorer, ditto.