The Marble Faun, Volume I by Nathaniel Hawthorne

The door of the courtyard swung slowly, and closed itself of its own accord. Miriam and Donatello were now alone there. She clasped her hands, and looked wildly at the young man, whose form seemed to have dilated, and whose eyes blazed with the fierce energy that had suddenly inspired him. It had kindled him into a man; it had developed within him an intelligence which was no native characteristic of the Donatello whom we have heretofore known. But that simple and joyous creature was gone forever.

"What have you done? " said Miriam, in a horror-stricken whisper.