CONSTITUENTS OF THE UNIVERSE. 



takes up room. In answer to that, we will 

 admit that if there is matter, it must neces- 

 sarily occupy space, or take up room. There 

 is no doubt whatever about the room, but how 

 do we know that it is occupied by matter? 

 Motion again does the same thing; for that 

 occupies space, or takes up room. 



When a solid explodes, hundreds of times 

 more room is occupied by the motion that fol- 

 lows the change from the solid to the gas; yet 

 there was the same amount of motion in the 

 solid before the explosion that there was in 

 the gas at the time of the explosion. 



When a given quantity of carbon, say 

 twelve pounds, unite with thirty-two pounds 

 of oxygen to produce forty-four pounds of car- 

 bon dioxide, there is after the change has 

 occurred, precisely the same amount of motion 

 in the forty-four pounds of carbon dioxide that 

 was in the twelve pounds of carbon and the 

 thirty-two pounds of oxygen before the chemi- 

 cal change occurred. That fact is established 

 convincingly by the motion called weight re- 

 maining the same. 



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