MIRACLES OF SCIENCE 



THE SMALLEST THING IN THE WORLD 



We have seen that the atoms which thus give up 

 their secrets to the photographic plate are billions 

 of times smaller than the smallest particle of matter 

 that is directly visible under the microscope. It 

 would seem, then, as if this recent feat of Sir Joseph 

 Thomson, together with the spectacular demonstra- 

 tions of Professor Rutherford, must carry us into the 

 realm of the invisible almost to the limits of imag- 

 inable minuteness. But in point of fact there 

 remains one other step that the physical investiga- 

 tors of our time have been able to take which would 

 still further tax credulity were it not certain that the 

 things recorded are the results of definite experi- 

 mentation and not of mere day-dreaming. 



The final feat of analysis to which I now refer is 

 that which demonstrates that within the smallest 

 atom there is a something almost two thousand times 

 smaller than the atom itself, a something that is 

 detachable from the atom and susceptible of being 

 measured as to its mass and tested as to its electric 

 charge with the aid of the apparatus of the laboratory. 



This ultimate particle of matter is called the elec- 

 tric corpuscle or electron. We owe our knowledge 

 of it chiefly to Sir Joseph J. Thomson, of Cambridge 

 University, England. It is the smallest thing in the 

 world; and it is probably the basal substance out of 

 which all matter of whatever character is built. Our 

 present view of it must be confined to a brief refer- 

 ence to the manner in which it has been weighed and 

 measured. 



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