NON-LIVING THINGS 22$ 



using a section of thin gas pipe, properly capped and fitted 

 with a delivery tube. Place some dry sawdust in the pipe 

 and shake it down into the end to be heated. Heat over 

 alcohol or gas flame until the vapor passes from the de- 

 livery tube in a sufficient quantity to light. With the same 

 apparatus use pulverized soft coal instead of sawdust. By 

 heating the coal gas is generated, which may be burned 

 similarly at the end of the delivery tube. 



By use of this simple generator collect a small quantity 

 of creosote by condensing the gas from paper or wood. 

 Show the pupils that this liquid can be expanded again into 

 gas by heat. Place a few drops of the liquid in the barrel 

 of a bicycle pump, and heat over the alcohol lamp. The 

 liquid expands again into the heavy, gray gas, and flashes 

 into flame on being tested with a lighted taper. 



For experiments with a candle flame, a large candle is 



so much better than a small one that it pays to make it if 



it can not be secured otherwise. A mold 



Experiments for this p urpose can be made by rolling 

 with the . . 



Candle Flame heav y writing P a P er i nto a tube about an 

 inch and a quarter in diameter. The wick 

 should be several times the size of common candle wicking. 

 When this candle is lighted it does not catch as readily 

 as the wick of a kerosene lamp. Why not? At first, the 

 flame burns low, afterward it increases in size and bril- 

 liancy. Why? Call attention to its shape, which is the 

 result of molding by air currents. Tell the pupils that its 

 color is due to particles of carbon (soot) made incandescent 

 by heat. Hold a cold slip of glass in the flame for a mo- 

 ment, and show the carbon that condenses upon its surface. 

 Some of this carbon can be seen escaping unburned from 

 16 



