A heartfelt pathos reigns throughout, and if passages of sublimity are rare (though there are several which merit that name), the elevated moral feeling acts on our minds to prevent the enervating influence of mere tenderness and grief.[50] Besides his dramas, Metastasio composed at this period two canzonetti, which are among the best of his productions. The "Grazie agli inganni tuoi," or thanks of a lover to his lady for having disenchanted him by her caprices, is written at once with feeling and spirit. The "Partenza" is yet more beautiful. It was founded on the unfortunate attachment of a Viennese nobleman for a public singer, who at last yielded to the entreaties of his friends, in detaching himself from her, on condition that Metastasio should write some verses of adieu. The lover must have been satisfied, and the lady charmed, despite regret, by the passion, tenderness, and beauty of the poem which celebrates their separation. Metastasio's tranquil and prosperous life was broken in upon in 1740, by the death of the emperor Charles VI., who fell a victim to either poison or indigestion, after eating mushrooms. The poet was unfeignedly attached to his imperial master, whose moral and religious character was congenial to his own; and the disturbed state of Europe, immediately after, added to his regret. This prince had no son, and his daughter, Maria Teresa, succeeded to him as queen of Bohemia and Hungary. Her husband aspired to the imperial crown; but the influence of France caused the duke of Bavaria to be elected, under the title of Charles VII. This disappointment was not the only misfortune of the queen; the king of Prussia invaded Silesia almost immediately after her father's death, and Vienna being threatened with a siege, she was obliged to quit it, and to take refuge in Presburg. After a reign of four years, Charles VII. died, and the husband of Maria Teresa, then grand duke of Tuscany, was elected emperor in the year 1745, under the name of Francis I.: but the war still continued, and its various success, and the disasters, with which it was attended, gave the court little leisure or inclination for amusement, until the peace of Aix-la-Chapelle.