WHAT THIS WORLD IS MADE OF 



But could our eyes open on this molecular world, 

 we should have the laugh on the old-time theologi- 

 ans and their quaint ideas of "dead" matter. We 

 should find the molecules of the quiet air speeding 

 about with the velocity of a cannon-ball ; a drop 

 of water would resemble a thick swarm of bees, 

 pounding against each other in their flight with 

 tremendous force. Even the crystalline diamond 

 would seem like pyramids of billiard-balls, hung 

 wide apart by invisible springs and gyrating in- 

 tensely. 



Probably, too, the molecules are whirling round 

 and round on their axes, like the earth ; and to ac- 

 count for their ability to send out light and heat 

 waves, we must suppose them to have vibrating 

 motion in and out as, for example, when you 

 flatten a rubber ball and then let it go. If you put 

 such a ball in water, you will see that the rebound 

 of the ball makes but a single ripple; our sensa- 

 tions of light are produced by ether-ripples beating 

 on the eye at the rate of from 450 to 750 million 

 millions per second. If we keep to our mechanical 

 ideas, then, we must imagine the molecule as a body 

 able to flatten and elongate itself with that same 

 rapidity. It is confessedly a puzzle, though, to 

 imagine just how these minute molecules, which 

 are probably not more than 0.2 fi/i in diameter, can 

 set up the relatively huge wave -motions we call 



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