A friend of ours, to whom we applied upon the subject, favoured us with the following information: - I have operated upon my own cranium for at least a dozen years, and though I have heard it affirmed that dyeing the hair will produce insanity. I am happy to think I am, as yet, perfectly sane, and under no fear of being otherwise;at all events, I am wiser than I once was, when I paid five shillings for what I can now make myself for less than twopence! - but to the question:- I procure lime, which I speedily reduce to powder by throwing a little water upon it, then mix this with litharge (three quarters lime, and a quarter litharge), which I sift through a hue hair sieve, and then 1 have what is told at a high price under the name of Unique Powder" and the most effectual hair dye that has yet been discovered. But the application of it is not very agreeable, though simple enough: - Put a quantity of it in a saucer, pour boiling water upon it. and mix it up with a knife like thick mustard; divide the hair into thin layers, with a comb, and plaster the mixture thickly into the layers to the roots, and all over the hair. When it is all completely covered over with it, then lay all over it a covering of damp blue, or brown paper, then bind over it, closely, a handkerchief, then put on a nightcap over all, and go to bed; in the morning, brush out the powder, wash thoroughly with soap and warm water, then dry, curl, oil, etc. I wan-ant that hair thus managed will be a permanent and beautiful black, which, I dare say, most people would prefer to either gray or red. Now, notwithstanding the patient endurance and satisfactory experience of our friend, we very much doubt, whether one person in a hundred, would be content to envelope their heads in batter of this description, and then retire to rest. To rest! did we say? We envy not the slumbers enjoyed under these circumstances. We fancy we can do something still better for those who are ashamed of their gray hairs. The hair-dyes formerly used produced very objectionable tints. Latterly several perfumers have been Selling dyes, consisting of two liquids to be used in succession, at exceedingly high prices. The composition has been kept a close secret in the hands of a few. The procuring of it for publication in this work has been attended with con siderable difficulty, but our readers may take it as an earnest that no pains or expense will be spared to render really useful information.

271. Hair Dye, usually styled Colombian, Argentine, etc, etc. Solution No. I. Hydro8ulphuret of am-monia, one ounce;solution of potash, three drachms;distilled, or rain water, one ounce (all by measure). Mix, and put into small bottles, labelling it No. I. Solution No. II Nitrate of silver one drachm;distilled, or rain-water, two ounces. Dissolved and labelled No. II.

Direction. - The solution No. I. is first applied to the hair with a tooth brush, and the application continued for fifteen or twenty minutes. The solution No. II. is then brushed over, a comb being used to separate the hairs, and allow the liquid to come in contact with every part. Care must be taken that the liquid do not come in contact with the skin, as the solution No. II. produces a very permanent dark stain on all substances with which it comes in contact. If the shade is not sufficiently deep, the operation may be repeated. The hair should be cleaned from grease before using the dye.

To try the effect of hair-dye upon hair of any colour, cut off a lock and apply the dye thoroughly as directed above. This will be a guarantee of success, or will at least guard against failure.