The Electrophorus.--Exp. 68, To learn how to use the electrophorus.--Exp. 69, To study "charging by conduction."--Exp. 70, To study potential; Electromotive force.--Pressure; Potential; Electromotive force; Current, Spark.--Theories about Electrifications.--Exp. 71, To study some methods of discharging an electrified body.--Disruptive, Conductive and Convective Discharges.--Exp. 72, To study intermittent or step-by-step discharges.--Discussion.--Exp. 73, To ascertain the location of the charge upon an electrified conductor.--Discussion.--Hollow and Solid Conductors.--Exp. 74, To study the effect of points upon a charged conductor.--Electric Density.--Electric Wind. CHAPTER IX. =Induced Electrification= 60 Electric Fields; Lines of Force.--Exp. 75, To study electric induction.--Electric Polarization; Theory of Induction.--Exp. 76, To learn how to charge a body by induction.--Free and Bound Electrifications.--Exp. 77, To show that a neutral body is polarized before it is attracted by a charged one.--Polarization Precedes Attraction.--Exp. 78, To find whether electric induction will act through an insulator.--Dielectrics.--Exp. 79, To find whether a polarized conductor can act inductively upon another conductor.--Successive Induction.--Inductive Capacity.--Exp. 80, To study the action of the electrophorus.--Discussion.--Details of action.--Exp. 81, To see, hear, and feel the results of inductive influence and polarization.--Discussion. CHAPTER X. =Condensation of Electrification= 68 Exp. 82, To find whether a large surface will hold more electrification than a small one.--Electrical Capacity.--Exp. 83, To find whether the capacity of a given conductor can be increased without increasing its size.--Condensation; Condensers.--The Leyden Jar.--Fulminating Panes.--Induction Coil Condensers.--Submarine Cables.--Exp. 84, To study the condensation of electrification.--Discussion.--Exp. 85, To study the action of the condenser.--Discussion.--Exp. 86, To study the effect of electrical discharges upon the human body.--Shocks; Dischargers.--Exps. 87-88, To show the strong attraction between opposite electrifications in the condenser.--Discussion.--Exp. 89, To show how the condenser may be slowly discharged.--The Electric Chime.--Exp. 90, To ascertain the location of a charge in a condenser.--Discussion.--Exp. 91, To find whether any electrification remains in the condenser after it has once been discharged.--Residual Charge.--Exp. 92, To study successive condensation; the chime cascade.--Discussion. CHAPTER XI. =Electroscopes= 77 Electroscopes.--Our leaf electroscope.--Exp. 93, To study the leaf electroscope; charging by conduction.--Discussion.--Exp. 95, To learn some uses of the electroscope.--Discussion.--The Proof-plane.