INTRODUCTION TO GENERAL SCIENCE 



1. EXPLOSIONS 



IF we take a little gunpowder, or guncotton, and apply 

 enough heat to make it " catch fire," the material will burn 

 in a flash. If it is unconfined, it will burn quietly. On the 

 other hand, if we confine it in a proper receptacle, such as a 

 gun or cannon, and ignite it, there will be just as rapid com- 

 bustion as in the first place. Since the material is confined, 

 however, there will be a sudden overcoming of this restraint, 

 producing what we call an explosion. 



Take a little ether on a pellet of cotton, place it on a 

 plate, and touch a burning match to it. The ether will burn 

 rapidly, although quietly. Put more ether upon another 

 pellet of cotton and place it in a wide-mouthed pint jar. 

 Place a glass plate over the top of the jar and invert three 

 or four times. Then cautiously slide the plate to one side 

 and light the mixture of ether and air. An explosion is the 

 result. 



Take a brass tube six inches long and one inch in diameter. 

 In one end place a tightly fitting cork stopper in which there 

 are two copper wires, separated, but approaching each other 

 to one sixteenth of an inch at that end of the stopper which 

 is inside of the tube. Attach an induction coil, giving at 

 least one quarter of an inch spark, to the other ends of the 

 copper wires. Make a small swab of cotton on a short 

 stick and swab out the "cannon," wetting the cotton with 

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