126 Lessons in Nature Study. 



jewelry (octahedra). Show them to the children. They are 

 very beautiful. 



Melt some sulphur. Let it begin to cool around the edge, 

 then quickly invert so as to pour out the melted part in the 

 middle. You will now see another kind of crystals all 

 around the place where the melted sulphur was poured out. 



Take a small keg. Hang some wet rags of various colors 

 inside. Then take a shovel of coals, sprinkle sulphur on 

 them, and quickly put it under the keg inverted. After a 

 time the colored rags will be found to have been bleached. 

 Tell the children that straw goods are bleached in this way. 



Many other suggestive experiments may be made. It is 

 not wise to give many chemical experiments like the fore- 

 going, and it is not advisable to attempt an explanation to 

 small children. 



Where is sulphur found ? This will open up the ever 

 interesting topic of volcanoes. 



Put some sulphur on a silver dollar ; it turns black. 

 Have you observed a silver spoon to turn black in your 

 experience (in stirring eggs) ? 



Why do silver knives and forks blacken when used to eat 

 cabbage ? Such questions set the child to thinking, and 

 disclose the presence of sulphur in many common articles 

 of food ; hence its presence in our flesh. 



III. Iron. 



Give each child a nail. A new one is best. 



Question so as to obtain color, weight, hardness and cold- 

 ness, and manner of breaking. 



Hold one end in the hand and heat the other end in a 

 lamp flame. What happens ? Conduction of heat. 



Heat a nail red-hot in a stove. Remove with a pair of 

 tongs. See the bluish-black scales that form upon it as it 

 cools. Call these scales " black rust " (black oxide). Put 

 another nail in water and leave it for a day or two. What 

 happens ? Red rust. 



Heat two nails red-hot, Plunge one into cold water. When 



