278. _To prevent Gentlemen's Hats from being injured by Rain._--Shake off the water as much as possible; then with a clean linen cloth or silk handkerchief wipe the hat carefully, keeping the beaver flat and smooth, in the same direction as it was first placed; then with hands fix it in the original shape, and hang it at a distance from the fire to dry. A few hours after, or the next morning, lay the hat on the table, and brush it round and round several times with a soft brush in the proper direction, and you will find your hat not in the least injured by the rain. If the gloss is not quite so high as you wish, take a flat iron, moderately heated, and pass the same two or three times gently over the hat; brush it afterwards; and it will be nearly as handsome as when first sent home from the shop. 279. _Dyeing._--Occasionally, when colored articles of silk, wool, or cotton have been cleaned, their color requires to be made deeper; at other times, it maybe desirable to change the color altogether, when that already in the stuff must be discharged, and the article dyed anew. Articles of any color may be dyed black, and black may easily be re-dyed. Blues can be made green or black; green may be made brown, and brown, green; and any color on re-dyeing, will take a darker tint than at first. A black may be dyed maroon, claret, or dark-brown; but green is the best color into which black can be changed. Most colors can be discharged by boiling the articles in water, with a small quantity of spirits of salts in it. Yellows, browns, and blues, are not easily discharged; maroons, reds of some kinds, and olives, may be easily discharged, by boiling them in water, with a small quantity of the following articles: roche-alum, for maroons; oil of vitriol--a very small quantity--for olives and grays; alum, pearlash, or soap, will discharge green to a yellow, which may be boiled off with soap. 280. _To Alum Silks._--Silk should be alumed cold, for when it is alumed hot, it is deprived of a great part of its lustre. The alum liquor should always be strong for silks, as they take the dye more readily afterwards. 281. _Various Dyes._--The following are the articles employed for the colors most in use, the proportions depending upon the depth or the shade required. _Lilac and Purple._--Boil archil in water; or, boil logwood in water; and, when cold, dip the article to be dyed into it, having previously passed it through a weak solution of alum in water. From logwood also may be obtained different shades of _Violet_. Effective _Lilac_ dyes may be produced from the berries of the Portugal laurel; and from the black currant, after the juice has been expressed. _Red_ is obtained from madder, and Brazil wood; the article being first dipped in weak alum and water, then in the dye, and lastly in a decoction of archil and water, to give it a bloom.