(C) Touch both tins at the same time, and note the action of the lower one.
_=191. Discussion.=_ This clearly shows how strongly the two electrifications are _bound_ in the condenser. Each refuses to escape to the earth, but they instantly rush together at the first opportunity. The dielectric may be shattered in a very heavily-charged condenser by this strong attraction.
=EXPERIMENT 89. To show how the condenser maybe slowly discharged.=
_Apparatus._ Fig. 55. The condenser (Exp. 83); the carbon electroscope with support (Exp. 58); the electrophorus (Exp. 68).
=192. Directions.= (A) Charge the condenser by means of the electrophorus; then hang the carbon so that it can swing between the upper conductor and E C placed as shown.
_=193. The Electric Chime.=_ The charging and discharging of the carbon being rapid, it acts like a _chime_ as it taps against the tins.
=EXPERIMENT 90. To ascertain the location of the charge in the condenser.=
_Apparatus._ The condenser, consisting of flat box, F B (Nos. 40, 41); ebonite sheet, E S (No. 27); insulating table, I T (Exp. 64); (when charging, arrange as in Fig. 52.); the electrophorus; hairpin discharger, H P D (No. 48).
=194. Directions.= (A) Charge the condenser with 15 or 20 good sparks from E C.
(B) Lift I T away from E S by its insulating handle, and set it upon the table. (It may be necessary to hold E S down.)
(C) Lift E S directly up and away from F B. (Lift by 2 corners; do not scrape E S along on F B; do not allow E S to touch your clothing.)
(D) Replace E S and then I T by its handle quickly, making the condenser complete again.
(E) With H P D see if the condenser still holds a charge. Touch F B first (Exp. 86).
_=195. Discussion.=_ As the _conductors_ were completely discharged, being left for a few moments upon the table, it is evident that the opposite electrifications must reside in and upon the _dielectric_. The conductors allow an even and _rapid_ discharge from all parts of the dielectric at the same time. The dielectric is considerably strained when a condenser is heavily charged. This strain, caused by the attraction of the opposite electrifications, may be great enough to break or puncture the dielectric.
=EXPERIMENT 91. To find whether any electrification remains in the condenser after it has once been discharged.=