What is an instrument for exciting electricity, and repeating the charge indefinitely by induction, consisting of a flat cake of resin, shelllac, or ebonite, upon which is placed a plate of metal called?

electrophorus — An instrument for exciting electricity, and repeating the charge indefinitely by induction, consisting of a flat cake of resin, shelllac, or ebonite, upon which is placed a plate of metal. (Webster's 1913.)

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