14 INTRODUCTION TO GENERAL SCIENCE 



one inch high with an inlet tube one fourth of an inch in diam- 

 eter, a one pint Kipp generator, rubber tubing. 



Materials: Turpentine, sodium peroxide in cubes. 



a. Fill alcohol lamp with turpentine, put collar around 

 wick and connect with the oxygen generator. Light the wick 

 before the oxygen is turned on, and notice the kind of flame 

 which is produced. Then gradually turn on the oxygen and 

 note the change which takes place in the flame. What is 

 smoke ? Why is it formed ? 



Sodium peroxide, when combining with water, forms so- 

 dium hydroxide or caustic soda, and sets free oxygen. To use 

 the Kipp generator, place a few pieces of sodium peroxide in 

 the middle bulb, put the parts together, and pour in enough 

 water to fill the lower bulb and about half of the middle bulb. 

 When the outlet is closed, the gas which is being generated 

 pushes the water away from the sodium peroxide, and thus the 

 action is stopped automatically. 



10. FLAMES 



All combustion is not accompanied by flames. Slow com- 

 bustion of any kind, whether in chemicals, in decaying matter, 

 or in the production of animal heat, does not produce flame. 

 It is only where the temperature is high enough to change the 

 solid or liquid fuel into gas that flames are produced. A 

 flame, then, is gas in combustion. 



In Section 28, Destructive Distillation, we shall see that 

 when any solid or liquid combustible is heated, part of its 

 material is changed into gas. The experiments will show 

 this fact in relation to a candle flame. 



1. 1703:35-36. Flames. 



2. 1703 : 214-219. Structure of Flames. 



