CONTENTS. IX 



CHAPTER XII. 



PACK 



ELECTRIC ATTRACTION AND REPULSION (so CALLED) ARE 

 RESULTANT MOVEMENTS 93 



Matter receives and transmits Impulses. Movements of Com- 

 pass Needles. Action and Reaction of Electrodes. Example 

 of the Wire-Frame. Natural Electric Currents. De la Rive's 

 Rings. Professor Barlow's Experiment. Ampere's floating 

 Helix Coil. Movements of Dipping Needles. Varying Posi- 

 tions of Dipping Needles. Action of Terrestrial Currents. 



CHAPTER XIII. 



THE CONTINUOUS CIRCULATION OF ELECTRIC CURRENTS 

 ABOUT MAGNETS AND MOLECULES SUSTAINS THEIR 

 POLARIZATION 104 



The Transmission of Electric Currents through Conducting Wires 

 wound spirally around Bodies produces Electro-magnets. Tran- 

 sient Electro-Magnetic Action. Movements developed by 

 Currents are not in the Direction of the Currents, but at right 

 angles to them. Lateral Movements produced. Whirling 

 Movements produced, as of Tornadoes. The Direction of a 

 Whirl reversed, by reversing the Direction of the Current. 

 Tornadoes produced by Electricity. Bodies revolved by 

 Heat. Light excites Electric Currents. Vertical Currents 

 turn Needles. Artificial Current-changer. Effect of chang- 

 ing the Direction of Electric Currents.- Sudden Reversal of 

 Currents. Unstable Electro-static Conditions. Photographic 

 Pictures. Mingled Hydrogen and Chlorine exploded by a 

 Gleam of Sunshine Reciprocal Action between Electric Cur- 

 rents and Magnetic Currents. The Static Needle. Magnetic 

 and Electric co-operation. Revolving Conducting Wires and 

 Wheels. Current-changer. Six thousand Rotations per 

 Minute. Currents and Magnets combined. Action of Lateral 

 Currents. 



CHAPTER XIV. 



DlAMAGNETISM . . . . ' 123 



The Circulation of Electric Currents about the Sides, or equato- 

 rial parts, of Bodies produces Impulses in a Direction at right 

 angles to that developed at the axial End, or Pole. While only 

 a few Substances, as Iron, Nickel, etc., develop permanent Polar 

 Actions, every Substance manifests Diamagnetic Currents, sim- 

 ilar to those about the Earth, which produce the horizontal 



