LESSONS ON ELECTRICITY. 



CONTENTS: 



Preface, - - 287 



Introduction. 



Historic Notes, 



The Art of Experiment, 



Materials for Experiment, 



Electric Attractions, - 290 



Disco s^ery of Conduction and Insulation, 



The Electroscope Further Inquiries on Conduction and Insulation, - 



Electrics and Non-Electrics, - ~9~> 



Electric Repulsions. Discovery of Two Electricities, - 296 



Fundamental Law of Electric Action, 29? 



Electricity of the Rubber. Double or " Polar " Character of Electric; Force, 29'J 



What is Electricity ? 301 



Electric Induction, Definition of the Term, - 303 



Experimental Researches on Electric Induction, 30:3 



The Electrophorus, 307 



Action of Points and Flames. 30S 



The Electrical Ma.chine, - 309 



Further Experiments on the Action of Points. The Electric- Mill The Golden 



Fish. Lightening Conductors, - Oil 



History of the Ley den Jar. The Leydeii Battery, - 314 



Explanation of the Ley den Jar, - 31.) 



Franklin's Cascade Battery, - 31? 



Novel Leydeh Jars of the Simplest Form, 

 Seat of Charge in the Leydeii Jar, 



Ignition by Electric Spark. Cottrel's Rubber. The Tube Machine. 320 



Duration of the Electric Spark, 

 Electric Light in Vacim, 

 Lichtenberg's Figures, 



Surface Compared with Mass. Distribution of Electricity in Hollow Conductors, 32(J 

 Physiological Effects of Electric Discharges, 

 Atmospheric Electricity, 

 Returning Stroke, 



The Leyden Battery, Its Currents, aiid some of their Effects, 

 Conclusion, 

 Appendix. An Elementary Lecture on Magnetism, 



