Stains of different kinds are removed either by dissolving the offensive matter out of the material which it has soiled or by destroying it. Ordinary washing is a good example of the first method; the removal of fruit stains by means of chloride of lime illustrates the second. Sometimes it is necessary to combine both methods. In practice it is of course necessary to avoid the use of any solvent or bleaching agent that can injure the material from which the stain is to be removed. The following is a list of the stains which most frequently occur, and also of the best methods of removing them:
Most acids produce red stains in all black or blue colors of vegetable origin. Where the acid has not been so strong as to injure the texture of the fabric, such stains may be easily removed by the use of a little potash, soda or ammonia. Nitric acid, however, not only turns red, but bleaches the goods, and it is very difficult to remove stains caused by this acid. It is said that the yellow stains formed on brown or black woolen goods by nitric acid can be removed, when freshly formed, by moistening them repeatedly with a concentrated solution of permanganate of potash, and then rinsing with water. Yellow stains on the hands may be treated in the same way, and the dark brown coloration produced may then be removed by treating with aqueous solution of sulphurous acid.
A solution of common sodium sulphite will rapidly remove the stains of rzost of the aniline dyes from the hands.
Most fruits yield juices which, owing to the acid they contain, permanently injure the tone of the dye; but the greater part may be removed without leaving a stain, if the spot be rinsed in cold water in which a few drops of aqua ammonite have been placed, before the spot has dried. Wine stains on white materials may be removed by rinsing with cold water, applying locally a weak solution of chloride of lime, and again rinsing in an abundance of water. Some fruit stains yield only to soaping with the hand, followed by fumigation with sulphurous acid; but the latter process is inadmissible with certain colored stuffs. If delicate colors are injured by soapy or alkaline matters, the stains must be treated with colorless vinegar of moderate strength.
1. "Where the fabric will bear it, the best method of removing grease spots is simple washing with soap and water. No ordinary grease spot will resist this.
2. Chalk, fuller's-earth, steatite or "French chalk." These should be merely diffused through a little water to form a thin paste, which is spread upon the spot, allowed to dry, and then brushed out.
3. Ox-gall and yolk of egg, which have the property of dissolving fatty bodies without affecting prrceptibly the texture or colors of cloth. The oxgall should be purified, to prevent its greenish tint from degrading the brilliancy of dyed stuffs, or the purity of whites. Thus prepared it is the most effective of all substances known for removing this kind of stains, especially for woolen cloths. It is to be diffused through its own bulk of water, applied to the spots, rubbed well into them with the hands till they disappear, after which the stuff is to be washed with soft water.
4. The volatile oil of turpentine. This will take out only recent stains; for which purpose it ought to be previously purified by distillation over quicklime.
5. Benzine or essence of petroleum is commoniy used for removing grease spots; but these liquids present the inconvenience of leaving, in most cases, a brownish mureola. To avoid this, it is necessary, whilst the fabric is still saturated, and immediately the stain has disappeared, to sprinkle gypsum or lycopodium over the whole of the moistened surface. When dry, the powder is brushed away.
5. Balls for removing grease spots are made as follows: Take fuller's-earth, free from all gritty matter; mix with half a pound of the earth, so prepared, half a pound of soda, as much soap, and eight yolks of eggs well beaten up with half a pound of purified ox-gall. The whole must be triturated upon a porphyry slab; the soda with the soap in the same manner as colors are ground, mixing in gradually the eggs and the ox-gall previously beaten together. Incorporate next the soft earth by slow degrees, till a uniform thick paste be formed, which should be made into balls or cakes of a convenient size, and laid out to dry. A little of this detergent being scraped off with a knife, made into a paste with water, and applied to the stain, will remove it.