CHAPTER XX 



A MODERN ALCHEMIST 

 Sir Ernest Rutherford and the Lilliputians 



IMAGINE an Association football as big as a room 

 — say about fifteen feet in diameter. Now imagine 

 an object the size of a pin's head fixed in the centre 

 of this great ball. Around that fixed centre, whirling at 

 dizzy speeds, imagine other bodies much smaller than the 

 pin-head nucleus. Now imagine all this on a scale in 

 accordance with which the football represents an object 

 measuring about the one-hundred-millionth of an inch 

 across, and you have the modern conception of the atom. 

 The fixed centre is called the proton, and although so 

 small (less than one-ten-thousandth the size of the atom) 

 it is enormously powerful, for the charge that it contains 

 controls the electrons which are its satellites. The whole 

 arrangement of an atom may be compared with the solar 

 system, having a sun in the centre and planets spinning 

 around it at various distances and in various paths. 

 Atoms are the tiny bricks which build up matter, and the 

 properties of an element are defined by the electric charge 

 on the nucleus of the atom. In the case of hydrogen, 

 lightest of all elements, this charge is sufficient to hold 

 only one satellite or electron, and by going up the scale 

 you reach at the top uranium, the nucleus of which is 

 sufficiently powerful to control no fewer than ninety-two 

 electrons. 



We have explained that an atom is so small that one 

 hundred million could be placed side by side in the space 

 of an inch, but even that statement gives very little idea 

 of their extreme minuteness. Let us put it this way. 



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