6/8 Reading-Course for Farmers' Wives. 



Action of acids on silk. Silk is readily attacked and disintegrated by 

 a concentrated acid solution. Dilute acid solutions weaken the fabric 

 but not so seriously as is the case with cotton. 



Action of alkalis on silk. Concentrated alkali solutions act upon silk 

 vigorously, but a little less vigorously than is the case with wool. Dilute 

 alkali solutions weaken the material and destroy its lustre. 



As laundering concerns itself constantly with the action of various 

 alkalis and acids, but chiefly the former, upon fabrics, the above outline 

 will be found an aid in grasping some of the reasons for certain laundry 

 processes, 



WATER 



A bountiful supply of water good for laundry purposes is an important 

 factor in successful laundering. Water is the natural solvent for much 

 of the dirt which accumulates on clothing and it acts as a carrier to rid 

 the clothing of all forms of dirt, both soluble and insoluble. Unfortu- 

 nately, good drinking-water is not necessarity equally good for laundry 

 purposes, as water may hold in solution substances not hurtful to health 

 but very detrimental to cleaning processes. A water good for the 

 laundry should, be clean, soft, clear, odorless, free from discoloration, 

 free from iron, free from organic matter. 



Hard and soft water. The very characteristic which renders water 

 so valuable as a detergent (a cleansing agent) — its solvent power — is 

 the cause of its greatest shortcomings, for on its way to us water may 

 pass over or through soils which contain soluble substances of an un- 

 desirable nature. The characteristic known as hardness, possessed by 

 some waters, is due to the presence of lime salts gathered in this way 

 Hard water is not the best for laundr}^ purposes as lime salts decompose 

 the soap used, forming in its place an insoluble lime-soap which collects 

 as a curd on the surface of the water. This soap decomposition takes 

 place as long as any lime remains, and the detergent (cleansing) prop- 

 erties of soap are not in operation until this is accomplished. Hard 

 water is said to weaken the fabric by leaving minute particles of the 

 lime-soap compound in its pores. If the available supply of water is 

 hard, the problem of the housekeeper is to find some means of removing 

 the lime or of reducing its ill effects. 



Temporary and permanent hardness. According to the nature of the 

 lime salts present, water is said to be temporarily or permanently hard. 

 Temporary hardness is caused by the presence of carbonate of lime, 

 and such water may be softened by boiling. If the water is allowed to 

 stand the lime settles to the bottom of the receptacle and the softened 

 water may be withdrawn from the top. Permanent hardness is due to 



