iio6 The Cornell Reading-Courses 



in the home, then, is the weekly washing. It is not merely in order to 

 gratify our sense of the aesthetic that we go to the extreme of upsetting 

 family routine for one day each week, but also to prevent soiled clothing 

 from becoming dangerous to its wearer. 



Why is soiled clothing dangerous to its wearer? — The skin acts as a heat- 

 regulating apparatus through evaporation of perspiration, and thus reduces 

 body heat. It also serves in some measiire to eliminate the wastes of the 

 body in the form of secretions. Perspiration and secretions are absorbed 

 by clothing, and bits of dead skin are continually being rubbed off to find 

 their way into the meshes of the fabric. After a time, the limit of absorp- 

 tion by the clothing is reached; its pores become clogged. The clothing 

 begins to have a damp, sticky, oily feeling. If it has been starched the 

 garment becomes limp. In this condition, if clothing is not actually 

 dirty it is at least unwholesome to wear, for it prevents proper absorption 

 and evaporation of moisture from the body and thus actually increases 

 its warmth in summer and its cold in winter. It is a matter of common 

 experience to mothers and niirses that the fretting of a small child may 

 sometimes be due to clothing that has become damp and sticky with wear. 

 A change to clean garments gives the needed relief, by furnishing a fresh 

 absorbing surface. 



Washing, then, has a threefold purpose : to remove dirt and thus reopen 

 the pores of the cloth ; to dry the cloth so as to renew its power of absorp- 

 tion ; and to destroy any bacteria that may be in it. As a household process 

 laundering often proves an arduous task instead of an interesting occupa- 

 tion, for, unfortunately, many houses are not equipped in a way to remove 

 the burdens incident to wash-day. An understanding of conditions will 

 greatly aid the person having the washing to do, though such knowledge 

 cannot take the place of proper equipment as a labor-saving device. 



FABRICS 



A first step toward gaining necessary knowledge of laundry methods is to 

 learn something of the nature of the fabrics to be laundered and how they 

 respond to the cleansing agents or solvents generally used in the laundry. 

 The common fibers used for clothing are of both vegetable and animal 

 origin. The chief vegetable fibers are cotton and linen ; the animal fibers, 

 wool and silk. Among the common laundry cleansing agents, called 

 reagents, are two classes of chemicals known as acids and bases. Acids 

 were so named because of the sour taste common to many of them. Acids 

 and bases possess as a characteristic property the power to unite with 

 each other to form a third substance called a salt. Therefore they are 

 said to neutralize each other; for the biting acid and the eating base have 

 through their union become harmless or neutral. For example: if hydro- 



