| 1. | This he readily accepted, trusting to the efficacy of the antidote. - from Myths and Legends of Ancient Greece and Rome by E.M. Berens |
| 2. | I wonder who first discovered the efficacy of poetry in driving away love. - from Pride and Prejudice by Jane Austen |
| 3. | Crunches looking about, as if he rather expected to see the loaf disappear under the efficacy of his wife's petitions. - from A Tale of Two Cities by Charles Dickens |
| 4. | The devoutest person could have rendered no greater homage to the efficacy of an honest prayer than he did in this distrust of his wife. - from A Tale of Two Cities by Charles Dickens |
| 5. | The third, those in which the efficacy of industry is either limited or uncertain. - from An Inquiry into the Nature and Causes of the Wealth of Nations by Adam Smith |
| 6. | Souls, it is said, more souls than one, were brought to the truth by the efficacy of that sermon, and vowed within themselves to cherish a holy gratitude towards Mr. - from The Scarlet Letter by Nathaniel Hawthorne |
| 7. | Man had marked this woman's sin by a scarlet letter, which had such potent and disastrous efficacy that no human sympathy could reach her, save it were sinful like herself. - from The Scarlet Letter by Nathaniel Hawthorne |
| 8. | It was impossible to doubt that, whatever painful efficacy there might be in the secret sting of remorse, a deadlier venom had been infused into it by the hand that proffered relief. - from The Scarlet Letter by Nathaniel Hawthorne |
| 9. | It is worthy of remark, as a curious physical instance of the efficacy of a sudden surprise in counteracting the effects of extreme fear, that her voice had quite recovered all its official asperity. - from Oliver Twist by Charles Dickens |