224 COMMON CHEMICAL PROCESSES 



fairly large or protected by a piece of platinum (Fig. 146), it 

 may be possible to show that H burns with a colorless flame. 



Experiment 143. Pour a little alcohol over a few bits 

 of charcoal (carbon) about the size of marbles. Pile these A 

 up on a glass or metal plate and light the mass. When I I 

 the charcoal is well kindled, JJJ 



note that it glows and gives <.! _.N.ig-. f: ^^^ 

 off light but no flame. What 

 is being formed? Why is 

 there no flame? Do not try this without the teacher's help. 



The substances commonly burned to furnish light 

 illuminating gas, kerosene, gasoline, and paraffin can- 

 dles are made up mostly of the gas hydrogen and 

 the solid carbon. Upon being lighted, the H burns and 

 furnishes the flame, while the C in tiny particles becomes 

 heated in this flame and glows, so that the whole gives 

 off light. When a lamp "smokes " it is because the oil 

 is being decomposed and the carbon particles given off 

 faster than they can be heated and burned in the flame. 

 In any case, smoke is made up of particles of matter that 



were not consumed 

 in the flame. 



Experiment 144. 



Light a candle and trim 



it to give a good flame. 



Hold a piece of earth- 

 FlG - 147 enware in this flame as 



in Fig. 147 ; note the de- 

 posit of soot. Of what is it composed? The solid object cools 

 the flame so that it does not consume all of the C that is given 

 off from the wick. 



263. Fire. As commonly used, the word fire may 

 easily give us a wrong idea of its meaning. A fire is 



