232 



CLOTHING AND ITS USES 



Method and Results : (a) Shrinking lest. Measure pieces of cotton cloth and 

 woolen cloth. Pour boiling water upon them and leave overnight. Dry 

 without stretching. When dry measure again. Is there any shrinkage ? 



(&) Test the solubility of cotton, woolen, and silk cloth in each of the 

 following : 



i. Cold concentrated hydrochloric acid. 2. Hot concentrated hydro- 

 chloric acid. 3. Cold diluted hydrochloric acid. 4. Hot diluted hydro- 

 chloric acid. 5. Make similar tests with concentrated and dilute nitric 

 acid, and concentrated and dilute sulphuric acid, both cold and hot. 

 Also make tests with cold and hot concentrated and dilute solu- 

 tions of sodium hydroxide, ammonia, borax, and washing soda. 

 Note any changes while the cloth is in the solution. Rinse and dry. 

 Are any other changes observed? Be very careful not to get any of 

 these solutions on your clothes or hands. 



Application: What precautions should be taken in washing clothing? 

 Can chemicals be used in finding out how much wool or other fiber 

 there is in a certain piece of cloth? Explain. 



Care of the clothes. Clothes are to be worn both for 

 comfort and for looks. All girls like to look attractive, 



but not always so with boys. 

 How many boys have lost a 

 good job just because of dirty 

 collars and shirts, or carelessly 

 blacked shoes. We may have 

 our clothes neat and clean, 

 even if they are not new. 

 Underclothes should be fre- 

 quently changed and washed, 

 especially in hot weather, as 

 they absorb the perspiration 

 and body wastes. We should 



be particular about changing socks and stockings fre- 

 quently, and washing the feet often as well. 



How to clean clothes. We know that in order to take 

 out soluble substances from clothes which have become 



