CHAPTER III 

 MATTER AND ITS PROPERTIES 



38. The Study of Science. By constant observation 

 and experiment, men have learned much about the earth 

 on which we live. What they have learned has enabled 

 them to do many things which would have seemed wonder- 

 ful to people who lived even one hundred years ago. 

 In order to understand the work going on about us 

 and the effects of changes that have occurred in the earth 

 and are still occurring, it is necessary to study the ele- 

 ments of science which men have learned in the centuries 

 preceding. 



39. Matter. The heavenly bodies are so distant that 

 we can use only the sense of sight in studying them; but to 

 find out all that we can about things near at hand, we may 

 use all our senses. We not only look at these things, 

 but we may handle them, or smell of them, sometimes taste 

 of them, or listen for sounds they may make. The name 

 matter has been given to everything that takes up room and 

 has. weight. We learn about matter by use of the senses. 

 The earth, the sun, bone, wood, brick, water, and air are all 

 made up of matter. 



There are two classes of matter, living and non-living. 

 Ability to move of itself and to grow distinguishes living 

 matter from non-living matter. 



Matter is believed to be composed of minute, invisible 

 particles called molecules. No one knows much about 

 molecules, but some facts are best explained by believing 

 that these invisible particles exist and that they are always 



46 



