"Bianca saw that she must renounce at present her design to give a successor to the ducal crown; she submitted to a miscarriage. The Cardinal, on his side, kept his word, and the unsuccessful attempt was never betrayed.
"A few months passed on; there was an uninterrupted harmony between the brothers, and Francesco invited the Cardinal, who was fond of field-sports, to pass some time with him at a country palace, famous for its preserves Of game.
"On the very day of his arrival, Bianca, who knew that the Cardinal was partial to a certain description of tart, bethought her to prepare one for him herself. This flattering attention on the part of his sister-in-law was hinted to him by Francesco, who mentioned it as a new proof of the Duchess's amiability, but, as he had no great confidence in his reconciliation with Bianca, it was an intimation which caused him not a little disquietude. Fortunately, the Cardinal possessed an opal, given to him by Pope Sixtus V., which had the property of growing dim the moment it approached any poisonous substance. He did not fail to make trial of it on the tart prepared by Bianca. The opal grew dim and tarnished. The Cardinal said, with an assumed air of carelessness, that, on consideration, he would not eat to-day of the tart. The Duke pressed him; but not being able to prevail--'Well,' said he, 'since Ferdinand will not eat of his favourite dish, it shall not be said that a Grand-duchess had turned confectioner for nothing--I will eat of it.' And he helped himself to a piece of the tart.
"Bianca was in the act of bending forward to prevent him--but suddenly paused. Her position was horrible. She must either avow her crime, or suffer her husband to poison himself. She cast a quick retrospective glance along her past life; she saw that she had exhausted all the pleasures of the world, and attained to all its glories; her decision was rapid--as rapid as on that day when she had fled from Venice with Pietro. She also cut off a piece from the tart, and extending her hand to her husband, she smiled, and, with her other hand, eat of the poisoned dish.
"On the morrow, Francesco and Bianca were dead. A physician opened their bodies by order of Ferdinand, and declared that they had fallen victims to a malignant fever. Three days after, the Cardinal threw down his red hat, and ascended the ducal throne."--P. 63.