28 



Our Surroundings 



of the bottle, the lime water will absorb the carbon dioxide 

 given off by the burning candle, and the nitrogen will be left in 



the bottle. Air must not be 

 allowed to mix with the nitro- 

 gen. This may be prevented 

 by keeping the opening of the 

 bottle covered. The student 

 will find that the gas is color- 

 less, odorless, and tasteless, 

 and that it will not burn or support combustion. 



Elements of Which Matter is Composed. There are about 

 90 known elements of which matter is composed. The table 

 below, for reference only, gives the names of some of the more 

 common elements, where they are found, the symbols which stand 

 for them, and some of their properties and uses. 



