CHAPTER XIX 



ELECTRICITY— RADIUM-, N-, AND X-RAYS 



Of late years our knowledge of the world's working 

 has been raised to another new and more advanced 

 level both by the discovery of radium-rays and other 

 mysterious emanations, and by a more practical 

 acquaintance with electrical engineering. 



Unfortunately this is not a time in which it is at all 

 safe to speak of these discoveries, for, like people who 

 are a little out of breath from climbing to the top of a 

 mountain ridge, our pioneers are not yet agreed as to 

 the meaning of the new scenery, nor as to how it fits 

 in with our older maps of the country. 



The exact nature of electricity is still a mystery, and 

 this of course prevents any satisfactory explanation 

 of its effects. 



It has been shown that the electrical potential of 

 the atmosphere increases with the height above the 

 earth. When rain falls, the electric potential of the 

 earth becomes very much greater. At the tower of 

 Meudon, near Paris, heavy rain increased the electric 

 potential, which was from 600 to 800 volts, to as much 

 as 12,000 to 15,000 volts.* 



So it is supposed that the subsoil water of the earth 

 must have a high electric potential, perhaps giving rise 

 to the mysterious earth-currents which affect our tele- 

 phones. If that is so, one would expect feeble electric 

 currents to be passing up living plants from the root 



* Compare *' Electricity of To-day." 

 211 



