84 WATER AND ITS EVERYDAY USES 



made from pure water vapor which was condensed high 

 in the air, therefore having little opportunity to get any 

 impurities into it. We can make any water pure by 

 distilling it, because this process forms water in much 

 the same way that it is made in the clouds. 



Demonstration 1. To Show How Water May Be Purified. 



Place a Florence flask on a ring stand, and bend a tube as shown 

 in the illustration. Pass it through a perforated cork which will 



fit in the mouth of the flask. 

 Fill the flask half full of water 

 colored with red ink and add 

 one teaspoonful of salt and two 

 of sugar. Place a lighted Bunsen 

 burner under the flask and put 

 a test tube at the lower end of 

 the tube. Allow the tube to 

 stand in cold water to keep it 

 cool. 



Observation. Soon after the 

 water boils, notice what happens. 

 Where do the drops of water 

 appear? Why do they appear 

 more frequently here? What is 

 the color of the water in the 

 test tube? Taste it. Result? 

 What substances put into the 

 flask do you find in the test tube ? This process of obtaining water 

 is called distillation. How does distillation purify water? 



Distillation. Distillation of water is very important. 

 It involves two distinct processes : vaporization, in which 

 the water is changed to steam, and condensation, in which 

 the steam is changed back to water. Natural waters, 

 which contain some impurities, if put into the storage 

 battery of the automobile would soon ruin the battery. 

 When large quantities of artificial ice are made, unless 

 the water is very pure it is first distilled before freezing. 

 When a large can of dirty water is freezing, the im- 

 purities separate and move to the center of the can 

 where the water is frozen last. 



