A black hair dye is best applied in two solutions. A well-known French form quoted in the " Chemist and Druggist ' is as follows:

The Hair No 5 Dyes Diseases Of The Scalp And Hair 100871

No. 1 Fluid.

Acid pyrogal, 1/2 dr.

Sodii sulphit., 10 gr.

Spt. rectificat., 1/2 oz.

Aq. ad., 2 oz.

No. 2 Fluid.

Argent. nit., 1 scruple.

Liq. ammon. fort., q.s.

Aq. ad., 2 oz.

Dissolve the nitrate in half an ounce of water, add ammonia until the precipitate is re-dissolved and make up to two ounces with water.

To use this dye, cleanse the hair from all grease by washing it with hot water in which a little soda has been dissolved, and dry with a towel. Next, pour a little of the fluid No. 1 into a saucer and apply with a white-haired, short-handled toothbrush. Immediately afterwards use No. 2 in the same way, with a black-haired brush, avoiding as much as possible touching the skin. Wipe the parts round the hair receiving the dye with a damp sponge, and do not wash or grease the hair for several hours after its application. The dye is best applied at night.

Hair restorers are slightly different from stains. They are really slow-acting dyes, and do not, of course, restore the natural colour to the hair. A well-known formula is as follows:

Acetate of lead, 1 1/2 dr.

Milk of sulphur, 3 dr.

Glycerine, 1 dr.

Heliotrope perfume, 2 dr.

Rose water, 10 oz.

Mix the powders intimately and rub up with the glycerine; gradually add the water and lastly the perfume.

Hair bleaches are less used than formerly, as they are found to considerably injure the hair. Peroxide of hydrogen was the medium used very largely a few years ago to obtain the golden or " cornfield " shade then so much in vogue. A ten vol. solution of peroxide of hydrogen is the strength generally employed. After washing and drying the hair, the solution is applied carefully with a sponge or with a small hairbrush damped with it. It is used once a week or fortnight, according to the colour of the hair. The effect of the continued use of peroxide of hydrogen is to cause the hair to become very dry and brittle, to break off at the roots, and, frequently, to become prematurely grey. A solution of bichloride of tin, with a mordant of hydro-sulphuret of ammonia, gives a rich golden tint to light hair and an autumnal brown to dark hair. Acetate and nitrate of lead, with a mordant of chromate of potash, gives a yellow hue. A solution of sulphate of copper, sixty grains to one ounce of water, well applied to the hair, and, an hour afterwards, the same quantity of ferro-cyanide of potassium in water, will dye light hair a rich golden brown. It is not advisable, however, to experiment in making hair dyes at home. The manufacture of such preparations must always be left to the chemist. It must be remembered that all dyes have only a mechanical effect on the hair already formed, and no effect on that which is in formation.