MORE ABOUT ELECTRONS 8i 



"Electrons in orbital motion," says Sir Oliver 

 Lodge, " have been shown to constitute the mech- 

 anism by which atoms are able to radiate light ; 

 and a great mass of semi-astronomical facts concern- 

 ing these orbits and their perturbations have been 

 obtained by immersing the source of light in a 

 strong magnetic field, and observing the minute 

 but very definite changes of spectra thereby 

 produced." 



So far has scientific imagination ventured that 

 models have been made to illustrate the architec- 

 ture of an atom, and even the laws that govern 

 the number of the corpuscles in their several solar 

 systems. Professor Mayer thrust magnetised 

 needles through pieces of cork and floated therri 

 so that their negative poles projected above the 

 water. The negative poles, in accordance with 

 the laws of electricity, repel each other, just as the 

 corpuscles charged with negative electricity must 

 do. In order, however, to complete the atom, the 

 positive electricity must be represented, and 

 Professor Mayer represented it by suspending 

 over the needles the positive pole of a magnet. 

 The needles thus repelled by each other and 

 attracted by the magnet give a fair picture of 

 atomic conditions ; and by studying such arrange- 

 ments and by mathematical calculations. Professor 

 T. T. Thomson and others have succeeded in 

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