Both Uses of
efficacy
in
Rappaccini's Daughter
- These incidents, however, dissolving in the pure light of her character, had no longer the efficacy of facts, but were acknowledged as mistaken fantasies, by whatever testimony of the senses they might appear to be substantiated.†
efficacy = effectiveness
- there is a medicine, potent, as a wise physician has assured me, and almost divine in its efficacy.†
*
Definition:
effectiveness (the ability to produce a desired result)