240 BLEACHING 



One of these compounds, namely, chloride of lime, is the 

 almost universal bleaching agent of commerce. It comes in 

 the form of powder, which can be dissolved in water to form 

 the bleaching solution in which the colored fabrics are im- 

 mersed. But fabrics immersed in a bleaching powder solution 

 do not lose their color as would naturally be expected. The 

 reason for this is that the chlorine gas is not free to do its 

 work, but is restricted by its combination with the other sub- 

 stances. By experiment it has been found that the addition 

 to the bleaching solution of an acid, such as vinegar or lemon 

 juice or sulphuric acid, causes the liberation of the chlorine. 

 The chlorine thus set free reacts with the water and liberates 

 oxygen ; this in turn destroys the coloring matter in the fibers, 

 and transforms the material into a bleached product. 



The acid used to liberate the chlorine from the bleaching 

 powder, and the chlorine also, rot materials with which they 

 remain in contact for any length of time. For this reason, 

 fabrics should be removed from the bleaching solution as 

 soon as possible, and should then be rinsed in some solution, 

 such as ammonia, which is capable of neutralizing the harm- 

 ful substances ; finally the fabric should be thoroughly rinsed 

 in water in order that all foreign matter may be removed. 

 The reason home bleaching is so seldom satisfactory is that 

 most amateurs fail to realize the necessity of immediate 

 neutralization and rinsing, and allow the fabric to regain too 

 long in the bleaching solution, and allow it to dry with traces 

 of the bleaching substances present in the fibers. Material 

 treated in this way is thoroughly bleached, but is at the same 

 time rotten and worthless. Chloride of lime is frequently 

 used in laundry work ; the clothes are whiter than when 

 cleaned with soap and simple washing powders, but they 

 soon wear out unless the precaution has been taken to add an 

 " antichlor " or neutralizer to the bleaching solution. 



