2 INTRODUCTION TO GENERAL SCIENCE 



naphtha, benzine, ether, alcohol, and gasoline, in turn. Each 

 time, immediately after swabbing, close the open end of the 

 cannon with another stopper, loosely fitted, and explode the 

 mixture by means of electricity. The cork will be driven 

 forcibly from the " cannon." 



We conclude that if anything is burnt very rapidly in an 

 inclosed space, an explosion will result. The conditions 

 necessary for such a burning will be discussed in Section 4, 

 Combustion. 



References: 



1. 1703 : 16. Explosion of Hydrogen. 



2. 1703:30. Deflagration the- Explanation of Explosions, 

 a. 1704 : 196. Explosions in Mines. 



&. 1708:111-112. Explosion. 



c. 1709 : 30. Gas Explosion. 



d. 1711:286-287. Mine Explosions. 



2. COMPOSITION OF MATTER DEFINITION OF HEAT 



There are many facts which indicate that all matter is 

 made up of small particles called molecules, and that these 

 molecules are in constant motion. If they move fast, we say 

 that the body is warm, and if we touch the body, we receive 

 the sensation of heat. If we apply heat to a body, the mole- 

 cules move faster; if by any means we make the molecules 

 move faster, the body is warmer. If we hammer, rub, or in 

 any way disturb the molecules, the body becomes hotter. 

 We have merely to rub our hands together to realize this, 

 and we are all familiar with the fact that a piece of lead, 

 when hammered, becomes very hot. When these molecules 

 move about, it is quite apparent that they need more room 

 than if they had remained still ; therefore nearly all bodies, 



