EXPERIMENT 91. To find whether any electrification remains in the condenser after it has once been discharged.
Apparatus. The condenser ([Fig. 52]); the electrophorus ([Exp. 68]); hairpin discharger, H P D.
196. Directions. (A) Thoroughly charge the condenser.
(B) Discharge it with H P D, being sure to touch F B first, and to touch I T for an instant while H P D is against F B.
(C) After a few moments use H P D again, and see if you get a slight spark.
197. Residual Charge. The two electrifications on the opposite sides of the dielectric have such an attraction for each other, when the condenser is charged, that they seem to penetrate, or soak into, the dielectric. These do not completely soak out again at the discharge. The small amount left is called a residual charge.
EXPERIMENT 92. To study successive condensation; the chime cascade.