204 ACIDS, ALKALIES, AND CLEANING 



When we use gasoline as a cleaning agent, we should 

 take great care to remain away from a fire. Especially 

 should we use care in rubbing silk that is wet with gaso- 

 line, lest the gasoline may be set on fire. 



230. Removal of Stains. When we wish to remove a stain from a 

 fabric, we should consider whether the substance causing the stain 

 must be changed chemically, or whether it can be removed by physical 

 means. Thus, paraffin (" white wax "), the material of many candles, 

 especially of colored candles, is not a fat, and cannot be saponified by 

 lye and soap. It is, however, readily dissolved by benzine, gasoline, 

 or ether, and can thus be removed. An excellent way is to wet the 

 paraffin spot with benzine, and then to press it, by means of a flat iron, 

 between blotters. 



Milk and cream stains, if fresh, are washed out with cold water. If, 

 however, they are old stains, the water of the milk will have evaporated, 

 leaving the fat in the fiber. To remove them we use soap and water, 

 or ammonia water, or we moisten the spot with benzine and press it 

 between blotters. Ammonia water, like soap and lye, saponifies the 

 fat and makes it soluble. 



Iron rust must be removed by chemical means. It is a base (ferric 

 oxide or hydroxide) ; hence we use an acid to remove it. Dilute hydro- 

 chloric acid (cf. 111), lemon juice and salt, etc., are commonly used. 

 The acid must then be rinsed out and neutralized. 



Ink stains are often hard to remove, because we cannot be sure of 

 what the ink is made. Fresh ink stains are usually taken out by fresh 

 milk. Old stains are soaked in water, and treated with oxalic acid 

 (10% solution). The acid is a poison. It should finally be rinsed out 

 with water, and neutralized by a mild base like borax or ammonia 

 water. 



Old-fashioned inks contained iron compounds; hence stains caused 

 by them are treated like iron rust. 



We must remember that most active chemicals, such as acids and 

 bases, affect dyes (cf. 215); hence they can rarely be used to remove 

 stains from colored fabrics. The cleaning agent should be used with a 

 piece of the goods, before it is applied to the garment. Acids spilled 



