EXERCISE 15 



Problem. To show growth of crystals. 



What to use. Water ; tumbler or beaker ; rod ; thread. Select one of several 

 substances, such as sugar, alum, hypo salt, table salt, copper sulfate, etc. 



What to do. Stir into half a glass of warm water a little more of your chemical 

 substance than can be completely dissolved. Weight a thread with a crystal of the 

 substance used in the experiment, and suspend in the solution ; leave undisturbed 

 for a few days. 



Record. Note what happens. If crystals are formed on the thread, dry, bring 

 to school, and place in school museum. 



Questions. 1. In what ways does the growth of a crystal differ from the growth of a baby? 



2. In what ways does the growth of a crystal differ from the growth of a plant ? 



3. What other things grow in the same way as a crystal ? 



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