18 ELEMENTARY GENERAL SCIENCE CHAP. 



Before the experiment is started, the candle is weighed and 

 also the tube containing the lumps of caustic soda. After the 

 experiment the same things are weighed over again. It will be 

 found that the tube B has increased in weight to a greater extent 

 than that of the candle has been diminished. We are quite 

 sure, therefore, that there has been no loss of matter. 



Chemists have satisfied themselves that this is universally true, 

 and it must be remembered as a truth of the highest importance, 

 matter is indestructible. 



CHIEF POINTS OF CHAPTER I. 



Matter. When we speak of matter we mean all things which 

 exist in or out of our world, which we can become aware of by the 

 help of our senses. 



Properties are certain effects caused by the things which are said 

 to possess them. 



Properties possessed by Matter. Matter occupies space, offers 

 resistance, possesses weight, and transfers motion to other things 

 when it strikes against them. 



The same Matter can exist in three different States. The three 

 states of matter are the solid, liquid and gaseous. By suitable 

 means, as in the experiments described in the chapter, the same 

 portion of matter can be made to assume these states in order. 

 Sometimes the change from one state to another is gradual, some- 

 times sudden. There is no hard and fast line between the three 

 conditions of matter. 



Distinctive Characters of Solids. A solid body does not readily 

 alter its size or shape. It will keep its own volume and the same 

 form unless subjected to a considerable force. Or, we may say solids 

 possess rigidity. 



Solids possess Elasticity, Tenacity, Ductility and Hardness. 



Elasticity is the tendency to go back to the original form or volume 

 after being forced out of it. 



Tenacity is measured by ascertaining what weight is necessary to 

 break solids when in the form of wires. 



Ductility is the property by virtue of which solids can be made 

 into wires. 



Malleability is a similar property to ductility which enables 

 certain solids to be beaten out into sheets. 



Hardness is the property by virtue of which solids offer resistance 

 to being scratched or worn by others. 



Distinctive Characters of Liquids. A liquid adapts itself to the 

 shape of the vessel containing it, but the conditions remaining the 

 same, it keeps its own size or volume, however much its shape- may 

 vary. 



Liquids possess Fluidity. When a liquid is not held by the sides 



