130 Lessons in Nature Study. 



children. Smell, taste, and cleansing power all prove it to be 

 a soap. Compare it with the piece of soap. Ask questions 

 about soap-making. Try to make soap, using lard instead 

 of the oil 



VIII. Sugar. 



Sugar should be passed around the class. Different kinds 

 of sugar should be compared. Rock candy is pure trans- 

 parent crystals. Powdered sugar is white. Why? Sugar 

 on the skins of figs is not sweet. Sugar crystallized from 

 molasses is brown. Describe the way maple sugar is made, 

 beet sugar, sorghum. Dissolve white sugar in water. Let it 

 stand to get the crystals. Describe them. Heat dry sugar. 

 It changes to caromel. 



g|3j IX. Rubber.- 



To make a lesson on rubber interesting, the teacher 

 should have samples of this substance in all stages of manu- 

 facture. The gum, sheet rubber, dental rubber, vulcanized 

 rubber in all its forms, should be on hand. Many lessons 

 may be given on it because of its diversified forms and 

 manifold uses. 



(a) Soft Rubber. 



Feel it, smell it, ascertain all its physical properties. 

 Heat a small piece. Burn it. Smell it when burning. 

 Dental rubber may be had from any dentist. It is very 

 thin and soft, and it is wonderfully elastic. Some kinds of 

 chewing-gum are almost pure rubber. 



(b) Hard Rubber. 



Combs, pen-holders, etc., are common. From these the 

 various properties of hard rubber may be ascertained. The 

 way in which hard rubber is made from soft rubber is a 

 secret, but much may be learned about it in cyclopaedias. 



